High rates of apoptosis in human Mycobacterium ulcerans culture-positive buruli ulcer skin lesions.
Buruli ulcer, a disease caused by Mycobacterium ulcerans, causes ulcerative skin disease likely generated by a toxin that mediates apoptosis. We analyzed paraffin-embedded sections of surgically excised Buruli ulcer lesions (two ulcers and one edematous plaque) and adjacent non-lesional skin samples (n = 9) for apoptosis by an indirect immunofluorescent terminal deoxynucleotide transferase-mediated dUTP-digoxigenin nick end labeling (TUNEL) assay. All samples were stained for acid-fast bacilli (AFB) and cultured for mycobacteria, and most were analyzed with an M. ulcerans-specific diagnostic polymerase chain reaction (PCR). TUNEL (+) bodies were numerous in both ulcers and the plaque, and sparse or absent in adjacent non-lesional skin. The AFB tissue stains and cultures for M. ulcerans were positive only in the three lesions. The result of the PCR for M. ulcerans was positive in all three lesions and in four of six non-lesional tissue samples; three contained sparse TUNEL (+) bodies. An abundance of TUNEL (+) bodies in the three AFB stain (+), culture (+), and PCR (+) Buruli ulcer lesional samples, but not in nearby AFB stain (-), culture (-), and PCR (+) non-lesional skin samples, strengthen the evidence that apoptosis is an important tissue destruction mechanism in human lesions closely associated with viable M. ulcerans.


Lower molar shape and size in prosimian and platyrrhine primates.
The goal of this research is to evaluate the relative strength of the influences of diet, size, and phylogenetic signal on dental geometric shape. Accurate comprehension of these factors and their interaction is important for reconstructing diet and deriving characters for a cladistic analysis in fossil primates. Geometric morphometric analysis is used to identify axes of shape variation in the lower second molars of (a) prosimian primates and (b) platyrrhines. Landmarks were placed on µCT-generated surface renderings. Landmark configurations were aligned using generalized Procrustes analysis. Principal components analysis and phylogenetic principal components analysis (pPCA) were performed on species average landmark co-ordinates. pPCs were examined with phylogenetic generalized least squares analysis for association with size and with diet. PCs from both phylogenetic and non-phylogenetic analyses were sufficient to separate species by broad dietary categories, including insectivores and folivores. In neither analysis was pPC1 correlated with tooth size, but some other pPCs were significantly correlated with size. The pattern of association between pPCs and size altered when centroid size and dietary variables were combined in the model; effects of diet factors typically exceeded effects of size. These results indicate a dominant phylogenetic and dietary signal in molar shape but also show some shape change correlated with size in the absence of obvious dietary associations. Geometric morphometric analysis appears to be useful for tracking functional traits in molars, particularly in tracking differences between folivorous and insectivorous species.


Roles of Pyruvate, NADH, and Mitochondrial Complex I in Redox Balance and Imbalance in β Cell Function and Dysfunction.
Pancreatic β cells not only use glucose as an energy source, but also sense blood glucose levels for insulin secretion. While pyruvate and NADH metabolic pathways are known to be involved in regulating insulin secretion in response to glucose stimulation, the roles of many other components along the metabolic pathways remain poorly understood. Such is the case for mitochondrial complex I (NADH/ubiquinone oxidoreductase). It is known that normal complex I function is absolutely required for episodic insulin secretion after a meal, but the role of complex I in β cells in the diabetic pancreas remains to be investigated. In this paper, we review the roles of pyruvate, NADH, and complex I in insulin secretion and hypothesize that complex I plays a crucial role in the pathogenesis of β cell dysfunction in the diabetic pancreas. This hypothesis is based on the establishment that chronic hyperglycemia overloads complex I with NADH leading to enhanced complex I production of reactive oxygen species. As nearly all metabolic pathways are impaired in diabetes, understanding how complex I in the β cells copes with elevated levels of NADH in the diabetic pancreas may provide potential therapeutic strategies for diabetes.


Altered Global mRNA Expressions of Pain and Aggression Related Genes in the Blood of Children with Autism Spectrum Disorders.
Autism spectrum disorder (ASD) is characterized by repetitive stereotypic behaviors, restricted interests, social withdrawal, and communication deficits. Aggression and insensitivity to pain are largely unexplained in these cases. We analyzed nine mRNA expressions of the candidate genes related to aggression and insensitivity to pain in the peripheral blood of patients with ASD. Whole blood samples were obtained from 40 autistic patients (33 boys, 7 girls) and 50 age- and sex-matched controls (37 boys and 13 girls) to isolate RNA. Gene expression was assessed by quantitative Real-Time PCR (qRT-PCR) in the Erciyes University Genome and Stem Cell Center (GENKOK). All of the gene expressions except CRHR1 and SLC6A4 were found to be statistically different between the ASD patients and controls. Gene expression also differed according to gender. Alterations in the mRNA expression patterns of the HTR1E, OPRL1, OPRM1, TACR1, PRKG1, SCN9A and DRD4 genes provide further evidence for a relevant effect of the respective candidate genes on the pathophysiology of ASD. Future studies may determine the sensitivity of these candidate markers in larger samples including further neuropsychiatric diagnosis.


Synthesis of a zigzag carbon nanobelt.
The structure-selective precise synthesis of carbon nanotubes (CNTs) has been long sought in materials science. The aromatic molecules corresponding to segment structures of CNTs, that is, carbon nanobelts (CNBs), are of interest as templates for CNT growth. Among the three types of CNB (armchair, chiral and zigzag CNBs), zigzag CNBs have been considered the most difficult type to synthesize. Here we report the synthesis, isolation and structural characterization of a zigzag CNB. The synthesis involves an iterative Diels-Alder reaction sequence followed by reductive aromatization of oxygen-bridged moieties. As predicted by theoretical calculations, this CNB was isolated as a stable compound. The structure of the zigzag CNB was fully characterized by X-ray crystallography and its wide energy gap with blue fluorescence properties was revealed by photophysical measurements. With synthetic strategies towards all three types of CNB in hand, the road to the precise synthesis of CNTs can now proceed to the next stage.


Malaria case-management under artemether-lumefantrine treatment policy in Uganda.
Case-management with artemether-lumefantrine (AL) is one of the key strategies to control malaria in many African countries. Yet, the reports on translation of AL implementation activities into clinical practice are scarce. Here the quality of AL case-management is reported from Uganda; approximately one year after AL replaced combination of chloroquine and sulphadoxine-pyrimethamine (CQ+SP) as recommended first line treatment for uncomplicated malaria. A cross-sectional survey, using a range of quality of care assessment tools, was undertaken at all government and private-not-for-profit facilities in four Ugandan districts. Main outcome measures were AL prescribing, dispensing and counseling practices in comparison with national guidelines, and factors influencing health workers decision to 1) treat for malaria, and 2) prescribe AL. 195 facilities, 232 health workers and 1,763 outpatient consultations were evaluated. Of 1,200 patients who needed treatment with AL according to guidelines, AL was prescribed for 60%, CQ+SP for 14%, quinine for 4%, CQ for 3%, other antimalarials for 3%, and 16% of patients had no antimalarial drug prescribed. AL was prescribed in the correct dose for 95% of patients. Only three out of seven AL counseling and dispensing tasks were performed for more than 50% of patients. Patients were more likely to be treated for malaria if they presented with main complaint of fever (OR = 5.22; 95% CI: 3.61-7.54) and if they were seen by supervised health workers (OR = 1.63; 95% CI: 1.06-2.50); however less likely if they were treated by more qualified health workers (OR = 0.61; 95% CI: 0.40-0.93) and presented with skin problem (OR = 0.29; 95% CI: 0.15-0.55). AL was more likely prescribed if the appropriate weight-specific AL pack was in stock (OR = 6.15; 95% CI: 3.43-11.05) and when CQ was absent (OR = 2.16; 95% CI: 1.09-4.28). Routine AL implementation activities were not associated with better performance. Although the use of AL was predominant over non-recommended therapies, the quality of AL case-management at the point of care is not yet optimal. There is an urgent need for innovative quality improvement interventions, which should be rigorously tested. Adequate availability of ACTs at the point of care will, however, ultimately determine the success of any performance interventions and ACT policy transitions.


Effect of Exercise Training and L-arginine on Oxidative Stress and Left Ventricular Function in the Post-ischemic Failing Rat Heart.
The aim of the present study was to evaluate the effect of exercise training (ET) and L-arginine on oxidative stress and ventricular function in rat with myocardial infarction (MI). Four weeks after the surgical procedures, 40 Wistar male rats were randomized to the following groups: MI-sedentary (Sed); MI-exercise (Ex); MI-sedentary + L-arginine (Sed + LA); and MI-exercise + L-arginine (Ex + LA); the rats were subjected to aerobic training in the form of treadmill running. Rats in the L-arginine-treated groups drank water containing 4 % L-arginine. Before and after the training program, all subjects underwent resting echocardiography. Catalase (CAT) glutathione peroxidase (GPx), malondialdehyde (MDA) and myeloperoxidase (MPO) were measured. Cardiac output, stroke volume and fractional shortening in Ex and Ex + LA groups significantly increased in comparison with the Sed group. Cardiac systolic function indices in Ex + LA group were significantly greater than Ex group. Also, GPx activity and MDA, respectively, increased and decreased in response to ET, but no change was observed in MPO and CAT. These results suggest that ET increased LV function by decreasing oxidative stress and increasing antioxidant defense system in rats with MI. In addition in response to training, L-arginine appears to have additive effect on cardiac function, but have no effect on oxidative stress indices.


Genetic dissection of light-induced Ca2+ influx into Drosophila photoreceptors.
Invertebrate photoreceptors use the inositol-lipid signaling cascade for phototransduction. A useful approach to dissect this pathway and its regulation has been provided by the isolation of Drosophila visual mutants. We measured extracellular changes of Ca2+ [delta Ca2+]o in Drosophila retina using Ca(2+)-selective microelectrodes in both the transient receptor potential (trp) mutant, in which the calcium permeability of the light-sensitive channels is greatly diminished and in the inactivation-but-no-afterpotential C (inaC) mutant which lacks photoreceptor-specific protein kinase C (PKC). Illumination induced a decrease in extracellular [Ca2+] with kinetics and magnitude that changed with light intensity. Compared to wild-type, the light-induced decrease in [Ca2+]o (the Ca2+ signal) was diminished in trp but significantly enhanced in inaC. The enhanced Ca2+ signal was diminished in the double mutant inaC;trp indicating that the effect of the trp mutation overrides the enhancement observed in the absence of eye-PKC. We suggest that the decrease in [Ca2+]o reflects light-induced Ca2+ influx into the photoreceptors and that the trp mutation blocks a large fraction of this Ca2+ influx, while the absence of eye specific PKC leads to enhancement of light-induced Ca2+ influx. This suggestion was supported by Ca2+ measurements in isolated ommatidia loaded with the fluorescent Ca2+ indicator, Ca Green-5N, which indicated an approximately threefold larger light-induced increase in cellular Ca2+ in inaC relative to WT. Our observations are consistent with the hypothesis that TRP is a light activated Ca2+ channel and that the increased Ca2+ influx observed in the absence of PKC is mediated mainly via the TRP channel.


Applications of biological surface active compounds in remediation technologies.
Many microorganisms synthesize a wide range of surface active compounds (SACs), classified according to their molecular weights, properties and localizations. The low molecular weight SACs or biosurfactants lower the surface tension at the air/water interfaces and the interfacial tension at oil/water interfaces, whereas the high molecular weight SACs, also known as bioemulsifiers, are more effective in stabilizing oil-in-water emulsions. The ability to biosynthesize SACs is, often, coupled with the ability of these microorganisms to grow on immiscible carbon sources, such as hydrocarbons. Different mechanisms are involved in the SACs interactions between microbial cells and immiscible hydrocarbons including: (i) emulsification, (ii) micellarization, (iii) adhesion-deadhesion of microorganisms to and from hydrocarbons and (iv) desorption of contaminants. These naturally occurring phenomena can be exploited by adding bioemulsifiers and biosurfactants into environments where bioremediation/biodegradation rates of organic pollutants is to be enhanced. However, analysis of the current literature show some cases where the complex interactions among SACs, microbial cells, organic substrates and environmental media led to an inhibition of the biodegradation. The understanding of the different physiological roles of SACs in microbial communities is fundamental in order to develop more effective remediation technologies exploiting both synthetic surfactants and microbial SACs. The physio-chemical properties of some microbial SACs have been exploited in hydrocarbon-contaminated soils washing and in mobilisation of soil-bound metal in metal-contaminated soils. Our ability to analyse the microbial diversity in the natural environments will expand our knowledge on microbial SACs with respect to their exploitation for commercial applications and their roles in the physiology of the producing microorganisms.


The bright incubate at night: sexual dichromatism and adaptive incubation division in an open-nesting shorebird.
Ornamentation of parents poses a high risk for offspring because it reduces cryptic nest defence. Over a century ago, Wallace proposed that sexual dichromatism enhances crypsis of open-nesting females although subsequent studies found that dichromatism per se is not necessarily adaptive. We tested whether reduced female ornamentation in a sexually dichromatic species reduces the risk of clutch depredation and leads to adaptive parental roles in the red-capped plover Charadrius ruficapillus, a species with biparental incubation. Males had significantly brighter and redder head coloration than females. During daytime, when visually foraging predators are active, colour-matched model males incurred a higher risk of clutch depredation than females, whereas at night there was no difference in depredation risk between sexes. In turn, red-capped plovers maintained a strongly diurnal/nocturnal division of parental care during incubation, with males attending the nest largely at night when visual predators were inactive and females incubating during the day. We found support for Wallace's conclusion that reduced female ornamentation provides a selective advantage when reproductive success is threatened by visually foraging predators. We conclude that predators may alter their prey's parental care patterns and therefore may affect parental cooperation during care.


Enhancing fluorescence detection with a photonic crystal structure in a total-internal-reflection configuration.
In contrast to fluorescence enhancement of fluorophores embedded in a photonic crystal structure as previously reported [Appl. Phys. Lett. 75, 3605 (1999)], in this Letter we demonstrate a unique approach to forming an open microcavity using a one-dimensional photonic crystal in a total-internal-reflection geometry. This configuration opens up the possibility for enhancing fluorescence imaging and biosensing. Time-resolved fluorescence detection of fluorophores immobilized on the open cavity has been carried out. Over 20-fold fluorescence enhancement was observed.


Cascade Ligand- and Structure-Based Virtual Screening to Identify New Trypanocidal Compounds Inhibiting Putrescine Uptake.
Chagas disease is a neglected tropical disease endemic to Latin America, though migratory movements have recently spread it to other regions. Here, we have applied a cascade virtual screening campaign combining ligand- and structure-based methods. In order to find novel inhibitors of putrescine uptake in Trypanosoma cruzi, an ensemble of linear ligand-based classifiers obtained by has been applied as initial screening filter, followed by docking into a homology model of the putrescine permease TcPAT12. 1,000 individual linear classifiers were inferred from a balanced dataset. Subsequently, different schemes were tested to combine the individual classifiers: MIN operator, average ranking, average score, average voting, with MIN operator leading to the best performance. The homology model was based on the arginine/agmatine antiporter (AdiC) from Escherichia coli as template. It showed 64% coverage of the entire query sequence and it was selected based on the normalized Discrete Optimized Protein Energy parameter and the GA341 score. The modeled structure had 96% in the allowed area of Ramachandran's plot, and none of the residues located in non-allowed regions were involved in the active site of the transporter. Positivity Predictive Value surfaces were applied to optimize the score thresholds to be used in the ligand-based virtual screening step: for that purpose Positivity Predictive Value was charted as a function of putative yields of active in the range 0.001-0.010 and the Se/Sp ratio. With a focus on drug repositioning opportunities, DrugBank and Sweetlead databases were subjected to screening. Among 8 hits, cinnarizine, a drug frequently prescribed for motion sickness and balance disorder, was tested against T. cruzi epimastigotes and amastigotes, confirming its trypanocidal effects and its inhibitory effects on putrescine uptake. Furthermore, clofazimine, an antibiotic with already proven trypanocidal effects, also displayed inhibitory effects on putrescine uptake. Two other hits, meclizine and butoconazole, also displayed trypanocidal effects (in the case of meclizine, against both epimastigotes and amastigotes), without inhibiting putrescine uptake.


EPR dosimetry intercomparison using smart phone touch screen glass.
This paper presents the results of an interlaboratory comparison of retrospective dosimetry using the electron paramagnetic resonance method. The test material used in this exercise was glass coming from the touch screens of smart phones that might be used as fortuitous dosimeters in a large-scale radiological incident. There were 13 participants to whom samples were dispatched, and 11 laboratories reported results. The participants received five calibration samples (0, 0.8, 2, 4, and 10 Gy) and four blindly irradiated samples (0, 0.9, 1.3, and 3.3 Gy). Participants were divided into two groups: for group A (formed by three participants), samples came from a homogeneous batch of glass and were stored in similar setting; for group B (formed by eight participants), samples came from different smart phones and stored in different settings of light and temperature. The calibration curves determined by the participants of group A had a small error and a critical level in the 0.37-0.40-Gy dose range, whereas the curves determined by the participants of group B were more scattered and led to a critical level in the 1.3-3.2-Gy dose range for six participants out of eight. Group A were able to assess the dose within 20 % for the lowest doses (<1.5 Gy) and within 5 % for the highest doses. For group B, only the highest blind dose could be evaluated in a reliable way because of the high critical values involved. The results from group A are encouraging, whereas the results from group B suggest that the influence of environmental conditions and the intervariability of samples coming from different smart phones need to be further investigated. An alongside conclusion is that the protocol was easily transferred to participants making a network of laboratories in case of a mass casualty event potentially feasible.


"Smart poisoning" of Co/SiO2 catalysts by sulfidation for chirality-selective synthesis of (9,8) single-walled carbon nanotubes.
The chirality-selective synthesis of relatively large (diameter > 1 nm) single-walled carbon nanotubes (SWCNTs) is of great interest for a variety of practical applications, but only a few catalysts are available so far. Previous studies suggested that S (compounds) can enhance the chirality-selectivity of Co catalysts in SWCNT synthesis, however, the mechanism behind is not fully understood, and no tailorable methodology has yet been developed. Here, we demonstrate a facile approach to achieve the chirality-selective synthesis of SWCNTs by the sulfidation-based poisoning of silica-supported Co catalysts using a mixture of H2S and H2. The UV-vis-NIR, photoluminescence, and Raman spectroscopy results together show that the resulting SWCNTs have a narrow diameter distribution of around 1.2 nm, and (9,8) nanotubes have an abundance of ∼38% among the semiconducting species. More importantly, the carbon yield achieved by the sulfided catalyst (2.5 wt%) is similar to that of the nonsulfided one (2.7 wt%). The characterization of the catalysts by X-ray diffraction, X-ray photoelectron spectroscopy, X-ray fluorescence, and H2 temperature-programmed reduction shows that the sulfidation leads to the formation of Co9S8 nanoparticles. However, Co9S8 nanoparticles are reduced back to regenerate metallic Co nanoparticles during the synthesis of SWCNTs, which maintain a high carbon yield. In this process, Co9S8 nanoparticles seemingly intermediate the production of Co nanoparticles with narrow size distribution. Due to the fact that the poisoning step improves the quality of the end-product rather than hampering the growth process, we have coined the process developed as "smart poisoning". This study not only reveals the mechanism behind the beneficial role of S in the selective synthesis of relatively large SWCNTs but also presents a promising method to create chirality-selective catalysts with high activity for scalable synthesis.


Distinct effects of blood flow and temperature on cutaneous microvascular adaptation.
We performed two experiments to determine whether cutaneous microvascular adaptations in response to repeated core temperature (Tc) elevation are mediated by increases in skin blood flow (SkBF) and/or skin temperature. Healthy subjects participated for 8 wk in thrice-weekly bouts of 30-min lower limb heating (40°C). In study 1, both forearms were "clamped" at basal skin temperature throughout each heating bout (n = 9). Study 2 involved identical lower limb heating, with the forearms under ambient conditions (unclamped, n = 10). In both studies, a cuff was inflated around one forearm during the heating bouts to assess the contribution of SkBF and temperature responses. We assessed forearm SkBF responses to both lower limb (systemic reflex) heating and to local heating of the forearm skin, pre- and postintervention. Acutely, lower limb heating increased Tc (study 1, 0.63°C ± 0.15°C; study 2, 0.69°C ± 0.19°C; P < 0.001) and forearm SkBF (study 1, 0.13 ± 0.03 vs 1.52 ± 0.51; study 2, 0.14 ± 0.01 vs 1.17 ± 0.38 cutaneous vascular conductance (CVC); P < 0.001), with skin responses significantly attenuated in the cuffed forearm (P < 0.01). SkBF responses to local heating decreased in study 1 (clamped forearms; week 0 vs week 8, 1.46 ± 0.52 vs 0.99 ± 0.44 CVC; P < 0.05), whereas increases occurred in study 2 (unclamped; week 0 vs week 8, 1.89 ± 0.57 vs 2.27 ± 0.52 CVC; P < 0.05). Cuff placement abolished local adaptations in both studies. Our results indicate that repeated increases in SkBF and skin temperature result in increased skin flux responses to local heating, whereas repeated increases in SkBF in the absence of change in skin temperature induced the opposite response. Repeated increases in Tc induce intrinsic microvascular changes, the nature of which are dependent upon both SkBF and skin temperature.


Learning a Comorbidity-Driven Taxonomy of Pediatric Pulmonary Hypertension.
Pediatric pulmonary hypertension (PH) is a heterogeneous condition with varying natural history and therapeutic response. Precise classification of PH subtypes is, therefore, crucial for individualizing care. However, gaps remain in our understanding of the spectrum of PH in children. We seek to study the manifestations of PH in children and to assess the feasibility of applying a network-based approach to discern disease subtypes from comorbidity data recorded in longitudinal data sets. A retrospective cohort study comprising 6 943 263 children (<18 years of age) enrolled in a commercial health insurance plan in the United States, between January 2010 and May 2013. A total of 1583 (0.02%) children met the criteria for PH. We identified comorbidities significantly associated with PH compared with the general population of children without PH. A Bayesian comorbidity network was constructed to model the interdependencies of these comorbidities, and network-clustering analysis was applied to derive disease subtypes comprising subgraphs of highly connected comorbid conditions. A total of 186 comorbidities were found to be significantly associated with PH. Network analysis of comorbidity patterns captured most of the major PH subtypes with known pathological basis defined by the World Health Organization and Panama classifications. The analysis further identified many subtypes documented in only a few case studies, including rare subtypes associated with several well-described genetic syndromes. Application of network science to model comorbidity patterns recorded in longitudinal data sets can facilitate the discovery of disease subtypes. Our analysis relearned established subtypes, thus validating the approach, and identified rare subtypes that are difficult to discern through clinical observations, providing impetus for deeper investigation of the disease subtypes that will enrich current disease classifications.


Steerable Wavelet Machines (SWM): Learning Moving Frames for Texture Classification.
We present texture operators encoding class-specific local organizations of image directions (LOIDs) in a rotation-invariant fashion. The LOIDs are key for visual understanding, and are at the origin of the success of the popular approaches, such as local binary patterns (LBPs) and the scale-invariant feature transform (SIFT). Whereas, LBPs and SIFT yield hand-crafted image representations, we propose to learn data-specific representations of the LOIDs in a rotation-invariant fashion. The image operators are based on steerable circular harmonic wavelets (CHWs), offering a rich and yet compact initial representation for characterizing natural textures. The joint location and orientation required to encode the LOIDs is preserved by using moving frames (MFs) texture representations built from locally-steered image gradients that are invariant to rigid motions. In a second step, we use support vector machines to learn a multi-class shaping matrix for the initial CHW representation, yielding data-driven MFs called steerable wavelet machines (SWMs). The SWM forward function is composed of linear operations (i.e., convolution and weighted combinations) interleaved with non-linear steermax operations. We experimentally demonstrate the effectiveness of the proposed operators for classifying natural textures. Our scheme outperforms recent approaches on several test suites of the Outex and the CUReT databases.


FoxH1 mediates a Grg4 and Smad2 dependent transcriptional switch in Nodal signaling during Xenopus mesoderm development.
In the vertebrate blastula and gastrula the Nodal pathway is essential for formation of the primary germ layers and the organizer. Nodal autoregulatory feedback potentiates signaling activity, but mechanisms limiting embryonic Nodal ligand transcription are poorly understood. Here we describe a transcriptional switch mechanism mediated by FoxH1, the principle effector of Nodal autoregulation. FoxH1 contains a conserved engrailed homology (EH1) motif that mediates direct binding of groucho-related gene 4 (Grg4), a Groucho family corepressor. Nodal-dependent gene expression is suppressed by FoxH1, but enhanced by a FoxH1 EH1 mutant, indicating that the EH1 motif is necessary for repression. Grg4 blocks Nodal-induced mesodermal gene expression and Nodal autoregulation, suggesting that Grg4 limits Nodal pathway activity. Conversely, blocking Grg4 function in the ectoderm results in ectopic expression of Nodal target genes. FoxH1 and Grg4 occupy the Xnr1 enhancer, and Grg4 occupancy is dependent on the FoxH1 EH1 motif. Grg4 occupancy at the Xnr1 enhancer significantly decreases with Nodal activation or Smad2 overexpression, while FoxH1 occupancy is unaffected. These results suggest that Nodal-activated Smad2 physically displaces Grg4 from FoxH1, an essential feature of the transcriptional switch mechanism. In support of this model, when FoxH1 is unable to bind Smad2, Grg4 occupancy is maintained at the Xnr1 enhancer, even in the presence of Nodal signaling. Our findings reveal that FoxH1 mediates both activation and repression of Nodal gene expression. We propose that this transcriptional switch is essential to delimit Nodal pathway activity in vertebrate germ layer formation.


Prophylactic epinephrine for the prevention of transbronchial lung biopsy-related bleeding in lung transplant recipients (PROPHET) study: a protocol for a multicentre randomised, double-blind, placebo-controlled trial.
Transbronchial lung biopsy (TBLB) is frequently performed in single-lung and double-lung transplant recipients for evaluation of clinical and radiological findings as well as routine surveillance for acute cellular rejection. While rates of clinically significant TBLB-related haemorrhage are <1% for all comers, the incidence in lung transplant recipients is reported to be higher, presumably due to persistent allograft inflammation and alterations in allograft blood flow. While routinely performed by some bronchoscopists, the efficacy and safety profile of prophylactic administration of topical intrabronchial diluted epinephrine for the prevention of TBLB-related haemorrhage has not been explored in a prospective manner. In this randomised, double-blind, placebo-controlled multicentre trial (PROPHET Study), single-lung and double-lung transplant adult recipients from participating institutions who are scheduled for bronchoscopy with TBLB for clinical indications will be identified. Potential participants who meet inclusion and exclusion criteria and sign an informed consent will be randomised to receive either diluted epinephrine or placebo prior to performance of TBLB. The degree of TBLB-related haemorrhage will be graded by the performing bronchoscopist as well as independent observers. The primary analysis will compare the rates of severe and very severe bleeding in participants treated with epinephrine or placebo. The study will also evaluate the safety profile of prophylactic topical epinephrine including the occurrence of serious cardiovascular and haemodynamic adverse events. Additional secondary outcomes to be explored include rates of non-severe TBLB-related haemorrhage, overall yield of the bronchoscopic procedure and non-serious cardiovascular and haemodynamic adverse effects. The study procedures were reviewed and approved by institutional review boards in participating institutions. This study is being externally monitored, and a data and safety monitoring committee has been assembled to monitor patient safety and to evaluate the efficacy of the intervention. The results of this study will be published in peer-reviewed scientific journals and presented at relevant academic conferences. NCT03126968; Pre-results.


Different food sources elicit fast changes to bacterial virulence.
Environmentally transmitted, opportunistic bacterial pathogens have a life cycle that alternates between hosts and environmental reservoirs. Resources are often scarce and fluctuating in the outside-host environment, whereas overcoming the host immune system could allow pathogens to establish a new, resource abundant and stable niche within the host. We tested if short-term exposure to different outside-host resource types and concentrations affect Serratia marcescens-(bacterium)'s virulence in Galleria mellonella (moth). As expected, virulence was mostly dictated by the bacterial dose, but we also found a clear increase in virulence when the bacterium had inhabited a low (versus high) resource concentration, or animal-based (versus plant-based) resources for 48 h prior to injection. The results suggest that temporal changes in pathogen's resource environment can induce very rapid changes in virulence and affect infection severity. Such changes could also play an important role in shifts from environmental lifestyle to pathogenicity or switches in host range and have implications for the management of opportunistic pathogens and disease outbreaks.


Colorimetric nucleic acid testing assay for RNA virus detection based on circle-to-circle amplification of padlock probes.
We developed a molecular diagnostic method for detection of RNA virus based on padlock probes and colorimetric readout. The feasibility of our approach was demonstrated by using detection of Crimean-Congo hemorrhagic fever (CCHF) virus as a model. Compared with conventional PCR-based methods, our approach does not require advanced equipment, involves easier assay design, and has a sensitivity of 10(3) viral copies/ml. By using a cocktail of padlock probes, synthetic templates representing different viral strain variants could be detected. We analyzed 34 CCHF patient samples, and all patients were correctly diagnosed when the results were compared to those of the current real-time PCR method. This is the first time that highly specific padlock probes have been applied to detection of a highly variable target sequence typical of RNA viruses.


The effects of a catheter clamping protocol on bladder function in neurosurgical patients: a controlled trial.
There is scant evidence-based literature on the best strategies for short-term urinary catheter removal. This clinical trial explored the effects of an early urinary catheter clamping protocol on bladder function in neurosurgical patients. Eligible patients were divided into observation and control groups. Those in the observation group had their catheter clamped postoperatively on return to the ward and unclamped at dedicated intervals. The control group received standard care; the catheter was on free drainage during the entire time in situ. The mean catheter indwelling time was 2.6 days. Compared with the control group, the observation group experienced shorter time to first postoperative urination, less residual urine volume and better subjective perception during their first postoperative urination. For patients undergoing neurosurgery and associated short-term indwelling urinary catheterization, an early catheter clamping protocol is effective in facilitating bladder function, reducing the rate of dysuria and making patients feel more comfortable after catheter removal.


The Drosophila P-element KP repressor protein dimerizes and interacts with multiple sites on P-element DNA.
Drosophila P elements are mobile DNA elements that encode an 87-kDa transposase enzyme and transpositional repressor proteins. One of these repressor proteins is the 207-amino-acid KP protein which is encoded by a naturally occurring P element with an internal deletion. To study the molecular mechanisms by which KP represses transposition, the protein was expressed, purified, and characterized. We show that the KP protein binds to multiple sites on the ends of P-element DNA, unlike the full-length transposase protein. These sites include the high-affinity transposase binding site, an 11-bp transpositional enhancer, and, at the highest concentrations tested, the terminal 31-hp inverted repeats. The DNA binding domain was localized to the N-terminal 98 amino acids and contains a CCHC sequence, a potential metal binding motif. We also demonstrate that the KP repressor protein can dimerize and contains two protein-protein interaction regions and that this dimerization is essential for high-affinity DNA binding.


Chronic transdermal nicotine patch treatment effects on cognitive performance in age-associated memory impairment.
Chronic transdermal nicotine has been found to improve attentional performance in patients with Alzheimer's disease (AD), but little is known about chronic nicotine effects in age-associated memory impairment (AAMI), a milder form of cognitive dysfunction. The current study was performed to determine the clinical and neuropsychological effects of chronic transdermal nicotine in AAMI subjects over a 4-week period. The double-blind, placebo-controlled, cross-over study consisted of two 4-week periods separated by a 2-week washout period. An outpatient setting was used. The subjects ( n=11) met criteria for AAMI. The subjects were given nicotine patches (Nicotrol) to wear for 16 h a day at the following doses: 5 mg/day during week 1, 10 mg/day during week 2 and week 3 and 5 mg/day during week 4. The effects of nicotine treatment were determined with the clinical global impressions questionnaire, Conners' Continuous Performance test, and the automated neuropsychologic assessment metrics (ANAM) computerized neuropsychology battery. Nicotine significantly improved the clinical global impression score as assessed by participants, as well as objective tests of attentional function on the Connors' Continuous Performance Test and decision reaction time on the neuropsychology test battery. Nicotine did not improve performance on other tests measuring motor and memory function. Chronic transdermal nicotine treatment in AAMI subjects caused a sustained improvement in clinical symptoms and objective computerized tests of attention. These results support the further investigation of nicotinic treatment as a promising therapy for AAMI.


The Chlamydia effector CT622/TaiP targets a nonautophagy related function of ATG16L1.
The obligate intracellular bacteria Chlamydia trachomatis, the causative agent of trachoma and sexually transmitted diseases, multiply in a vacuolar compartment, the inclusion. From this niche, they secrete "effector" proteins, that modify cellular activities to enable bacterial survival and proliferation. Here, we show that the host autophagy-related protein 16-1 (ATG16L1) restricts inclusion growth and that this effect is counteracted by the secretion of the bacterial effector CT622/TaiP (translocated ATG16L1 interacting protein). ATG16L1 is mostly known for its role in the lipidation of the human homologs of ATG8 (i.e., LC3 and homologs) on double membranes during autophagy as well as on single membranes during LC3-associated phagocytosis and other LC3-lipidation events. Unexpectedly, the LC3-lipidation-related functions of ATG16L1 are not required for restricting inclusion development. We show that the carboxyl-terminal domain of TaiP exposes a mimic of an eukaryotic ATG16L1-binding motif that binds to ATG16L1's WD40 domain. By doing so, TaiP prevents ATG16L1 interaction with the integral membrane protein TMEM59 and allows the rerouting of Rab6-positive compartments toward the inclusion. The discovery that one bacterial effector evolved to target ATG16L1's engagement in intracellular traffic rather than in LC3 lipidation brings this "secondary" activity of ATG16L1 in full light and emphasizes its importance for maintaining host cell homeostasis.


Impact of the Ananya program on reproductive, maternal, newborn and child health and nutrition in Bihar, India: early results from a quasi-experimental study.
The Government of Bihar (GoB) in India, the Bill and Melinda Gates Foundation and several non-governmental organisations launched the Ananya program aimed to support the GoB to improve reproductive, maternal, newborn and child health and nutrition (RMNCHN) statewide. Here we summarise changes in indicators attained during the initial two-year pilot phase (2012-2013) of implementation in eight focus districts of approximately 28 million population, aimed to inform subsequent scale-up. The quasi-experimental impact evaluation included statewide household surveys at two time points during the pilot phase: January-April 2012 ("baseline") including an initial cohort of beneficiaries and January-April 2014 ("midline") with a new cohort. The two arms were: 1) eight intervention districts, and 2) a comparison arm comprised of the remaining 30 districts in Bihar where Ananya interventions were not implemented. We analysed changes in indicators across the RMNCHN continuum of care from baseline to midline in intervention and comparison districts using a difference-in-difference analysis. Indicators in the two arms were similar at baseline. Overall, 40% of indicators (20 of 51) changed significantly from baseline to midline in the comparison districts unrelated to Ananya; two-thirds (n = 13) of secular indicator changes were in a direction expected to promote health. Statistically significant impact attributable to the Ananya program was found for 10% (five of 51) of RMNCHN indicators. Positive impacts were most prominent for mother's behaviours in contraceptive utilisation. The Ananya program had limited impact in improving health-related outcomes during the first two-year period covered by this evaluation. The program's theories of change and action were not powered to observe statistically significant differences in RMNCHN indicators within two years, but rather aimed to help inform program improvements and scale-up. Evaluation of large-scale programs such as Ananya using theory-informed, equity-sensitive (including gender), mixed-methods approaches can help elucidate causality and better explain pathways through which supply- and demand-side interventions contribute to changes in behaviour among the actors involved in the production of population-level health outcomes. Evidence from Bihar indicates that deep structural constraints in health system organisation and delivery of interventions pose substantial limitations on behaviour change among health care providers and beneficiaries. ClinicalTrials.gov number NCT02726230.


Naturalistic Speech-Generating Device Interventions for Children With Complex Communication Needs: A Systematic Review of Single-Subject Studies.
This article presents a systematic review that aimed to synthesize single-subject-design studies that have examined naturalistic interventions for teaching the expressive use of speech-generating devices (SGDs) to children with complex communication needs. Specifically, this review describes what intervention strategies are most commonly applied in studies with positive effects and minimal methodological flaws and examines the populations and outcomes for which these strategies have been effective. A systematic approach was used to qualitatively code variables of interest to this review. Results were summarized via both visual analysis and effect size methods, and a certainty of evidence methodology was adopted to describe the quality of the evidence. Thirty-two unique studies met inclusion criteria, with 19 having consistent positive results and meeting minimum requirements for certainty of evidence. Although studies used a variety of titles to describe intervention packages (e.g., milieu teaching, interaction strategies), certain strategies were common across studies. These included (a) creating and capturing communication opportunities via methods such as time delay and questioning; (b) providing feedback via methods such as reinforcement of requests, praise, or expansions; (c) prompting (verbal, physical, gestural); (d) modeling; and (e) training communication partners. Findings regarding these intervention components help to provide practical guidelines for naturalistic SGD intervention. Limitations of the current body of research (e.g., need to include more home-based studies and more intermediate to advanced SGDs, need to critically analyze the most critical intervention components) provide suggestions for future research. https://doi.org/10.23641/asha.6615332.


Deep sequencing of tomato short RNAs identifies microRNAs targeting genes involved in fruit ripening.
In plants there are several classes of 21-24-nt short RNAs that regulate gene expression. The most conserved class is the microRNAs (miRNAs), although some miRNAs are found only in specific species. We used high-throughput pyrosequencing to identify conserved and nonconserved miRNAs and other short RNAs in tomato fruit and leaf. Several conserved miRNAs showed tissue-specific expression, which, combined with target gene validation results, suggests that miRNAs may play a role in fleshy fruit development. We also identified four new nonconserved miRNAs. One of the validated targets of a novel miRNA is a member of the CTR family involved in fruit ripening. However, 62 predicted targets showing near perfect complementarity to potential new miRNAs did not validate experimentally. This suggests that target prediction of plant short RNAs could have a high false-positive rate and must therefore be validated experimentally. We also found short RNAs from a Solanaceae-specific foldback transposon, which showed a miRNA/miRNA*-like distribution, suggesting that this element may function as a miRNA gene progenitor. The other Solanaceae-specific class of short RNA was derived from an endogenous pararetrovirus sequence inserted into the tomato chromosomes. This study opens a new avenue in the field of fleshy fruit biology by raising the possibility that fruit development and ripening may be under miRNA regulation.


Sunlight inactivation of viruses in open-water unit process treatment wetlands: modeling endogenous and exogenous inactivation rates.
Sunlight inactivation is an important mode of disinfection for viruses in surface waters. In constructed wetlands, for example, open-water cells can be used to promote sunlight disinfection and remove pathogenic viruses from wastewater. To aid in the design of these systems, we developed predictive models of virus attenuation that account for endogenous and exogenous sunlight-mediated inactivation mechanisms. Inactivation rate models were developed for two viruses, MS2 and poliovirus type 3; laboratory- and field-scale experiments were conducted to evaluate the models' ability to estimate inactivation rates in a pilot-scale, open-water, unit-process wetland cell. Endogenous inactivation rates were modeled using either photoaction spectra or total, incident UVB irradiance. Exogenous inactivation rates were modeled on the basis of virus susceptibilities to singlet oxygen. Results from both laboratory- and field-scale experiments showed good agreement between measured and modeled inactivation rates. The modeling approach presented here can be applied to any sunlit surface water and utilizes easily measured inputs such as depth, solar irradiance, water matrix absorbance, singlet oxygen concentration, and the virus-specific apparent second-order rate constant with singlet oxygen (k2). Interestingly, the MS2 k2 in the open-water wetland was found to be significantly larger than k2 observed in other waters in previous studies. Examples of how the model can be used to design and optimize natural treatment systems for virus inactivation are provided.


Melting of gelatin gels confined to silica nanopores.
Nanoconfinement is a way to create materials whose properties differ from the bulk. For the first time, this research explores the effect of nanoconfinement on the thermodynamics and kinetics of gel melting. Differential scanning calorimetry has been employed to study gelatin gels prepared inside 4, 6, 15, and 30 nm pores of a silica matrix. It has been found that with decreasing the pore size the heat of melting decreases from 3.5 J g-1 in bulk to 0.6 J g-1 in 6 nm pores, which is linked to a decrease in crosslinks formed via hydrogen bonding. Despite decreases in crosslink formation, the melting temperature for gels confined to 6 nm pores increased nearly 10 °C compared to bulk gel. In 4 nm pores, no gel melting was observed. Isoconversional kinetic analysis of the melting data has revealed that the increase in thermal stability is associated with a decrease in the pre-exponential factor that occurs upon nanoconfinement. The origins of the effect have been linked to diminished molecular mobility of the gelatin chains confined inside the nanopores, which leads to enhanced restoration of broken crosslinks.


Injury-related fear-avoidance and symptoms of posttraumatic stress in parents of children with burns.
Parents of children with burns experience a range of psychological reactions and symptoms, and parents' health is known to impact children's health. So far, there is little research into potential mechanisms that maintain parents' symptoms. The aim was to investigate parental injury-related fear-avoidance, and its associations with injury severity and health measures. Parents (n=107) of children aged 0.4-18 years that sustained burns 0.1-9.0 years previously completed questionnaires on fear-avoidance, posttraumatic stress, and health of the child. Analyses showed that the average level of fear-avoidance was low and positively associated with measures of injury severity and parents' symptoms of posttraumatic stress, and negatively associated with parents' ratings of their child's health. In two separate multiple regressions with parents' symptoms of PTSD and the child's health as dependent variables, fear-avoidance made the largest contribution in both models while injury severity was non-significant. Results were not related to comorbid conditions of the child, scarring, or parent-related socio-demographic variables. In summary, injury-related fear-avoidance is more likely among parents whose children sustain more severe burns. In turn, fear-avoidance contributes significantly to parents' symptoms of PTSD and to poorer health ratings regarding the child, irrespective of injury severity or child comorbidity.


Effect of extreme sea surface temperature events on the demography of an age-structured albatross population.
Climate changes include concurrent changes in environmental mean, variance and extremes, and it is challenging to understand their respective impact on wild populations, especially when contrasted age-dependent responses to climate occur. We assessed how changes in mean and standard deviation of sea surface temperature (SST), frequency and magnitude of warm SST extreme climatic events (ECE) influenced the stochastic population growth rate log(λs) and age structure of a black-browed albatross population. For changes in SST around historical levels observed since 1982, changes in standard deviation had a larger (threefold) and negative impact on log(λs) compared to changes in mean. By contrast, the mean had a positive impact on log(λs). The historical SST mean was lower than the optimal SST value for which log(λs) was maximized. Thus, a larger environmental mean increased the occurrence of SST close to this optimum that buffered the negative effect of ECE. This 'climate safety margin' (i.e. difference between optimal and historical climatic conditions) and the specific shape of the population growth rate response to climate for a species determine how ECE affect the population. For a wider range in SST, both the mean and standard deviation had negative impact on log(λs), with changes in the mean having a greater effect than the standard deviation. Furthermore, around SST historical levels increases in either mean or standard deviation of the SST distribution led to a younger population, with potentially important conservation implications for black-browed albatrosses.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'.


Resolution and noise measurements of five CRT and LCD medical displays.
The performance of soft-copy displays plays a significant role in the overall image quality of a digital radiographic system. In this work, we discuss methods to characterize the resolution and noise of both cathode ray tube (CRT) and liquid crystal display (LCD) devices. We measured the image quality of five different commercial display devices, representing both CRT and LCD technologies, using a high-quality charge-coupled device (CCD) camera. The modulation transfer function (MTF) was calculated using the line technique, correcting for the MTF of the CCD camera and the display pixel size. The normalized noise power spectrum (NPS) was computed from two-dimensional Fourier analysis of uniform images. To separate the effects of pixel structure from interpixel luminance variations, we created structure-free images by eliminating the pixel structures of the display device. The NPS was then computed from these structure-free images to isolate interpixel luminance variations. We found that the MTF of LCDs remained close to the theoretical limit dictated by their inherent pixel size (0.85 +/- 0.08 at Nyquist frequency), in contrast to the MTF for the two CRT displays, which dropped to 0.15 +/- 0.08 at the Nyquist frequency. However, the NPS of LCDs showed significant peaks due to the subpixel structure, while the NPS of CRT displays exhibited a nearly flat power spectrum. After removing the pixel structure, the structured noise peaks for LCDs were eliminated and the overall noise magnitude was significantly reduced. The average total noise-to-signal ratio for CRT displays was 6.55% +/- 0.59%, of which 6.03% +/- 0.24% was due to interpixel luminance variations, while LCD displays had total noise to signal ratios of 46.1% +/- 5.1% of which 1.50% +/- 0.41% were due to interpixel luminance variations. Depending on the extent of the blurring and prewhitening processes of the human visual system, the magnitude of the display noise (including pixel structure) potentially perceived by the observer was reduced to 0.43% +/- 0.01% (accounting for blurring only) and 0.40 +/- 0.01% (accounting for blurring and prewhitening) for CRTs, and 1.02% +/- 0.22% (accounting for blurring only) and 0.36% +/- 0.08% (accounting for blurring and prewhitening) for LCDs.


Online sperm donation: a survey of the demographic characteristics, motivations, preferences and experiences of sperm donors on a connection website.
What are the demographic characteristics, motivations, preferences and experiences of heterosexual, gay and bisexual sperm donors on a connection website (i.e. a website that facilitates direct contact between donors and recipients of gametes)? This demographically diverse group of men was donating for altruistic reasons and perceived the website as providing greater choice over donation arrangements: approximately one third favoured anonymous donation, most of whom were heterosexual, whilst gay and bisexual donors were more likely to be in contact with children conceived with their sperm. Despite substantially more sperm donors being registered on connection websites than with clinics, there has been very little research on this population. Current understanding of the impact of sexual orientation on donors' attitudes is also limited. An online survey was conducted over 7 weeks with 383 men registered as sperm donors with Pride Angel, a large UK-based connection website for donors and recipients of sperm. The survey obtained data on participants' demographic characteristics and their motivations, preferences and experiences regarding online sperm donation, including attitudes towards contact with offspring. Differences according to participants' sexual orientation were examined. Most participants (80.4%, 308) were heterosexual, 10.5% (40) were gay and 9.1% (35) were bisexual; ages ranged from 18 to 69 years (median = 36, mean = 37.3, SD = 9.7). A greater proportion of gay and bisexual men desired open-identity donation (P < 0.005) and contact with offspring (P <0.005) than heterosexual men. Approximately one third (28.7%, 110) had donated sperm; 18.3% (70) had conceived at least one child, of whom a minority (25.7%, 18) were currently in contact with the child, comprising significantly more gay and bisexual than heterosexual men (P = 0.001). Heterosexual men were most likely to state a preference for natural insemination, although the large majority (94.3%, 66) of donors who had conceived children had used artificial insemination. Findings may not be representative of all sperm donors using connection websites because members of only one website participated and participants were, by necessity, a self-selected sample. This is the first comprehensive study of donors who connect with recipients via the internet, including a substantial number who have donated and conceived children. The findings indicate that sexual orientation may influence men's donation preferences and raise policy issues concerning donor recruitment and the incorporation of online sperm donation into clinical practice. This study was supported by the Wellcome Trust (097857/Z/11/Z). E.T. is the co-founder of Pride Angel; the remaining authors have no conflicts of interest.


Release of an invasion promoter E-cadherin fragment by matrilysin and stromelysin-1.
The function of many transmembrane molecules can be altered by cleavage and subsequent release of their ectodomains. We have investigated ectodomain cleavage of the cell-cell adhesion and signal-transducing molecule E-cadherin. The E-cadherin ectodomain is constitutively shed from the surface of MCF-7 and MDCKts.srcC12 cells in culture. Release of the 80 kDa soluble E-cadherin fragment is stimulated by phorbol-12-myristate-13-acetate and is inhibited by overexpression of the tissue inhibitor of metalloproteinases-2. The metalloproteinases matrilysin and stromelysin-1 both cleave E-cadherin at the cell surface and release sE-CAD into the medium. The soluble E-cadherin fragment thus released inhibits E-cadherin functions in a paracrine way, as indicated by induction of invasion into collagen type I and inhibition of E-cadherin-dependent cell aggregation. Our results, therefore, suggest a novel mechanism by which metalloproteinases can influence invasion.


HLA typing: Conventional techniques v. next-generation sequencing.
The large number of population-specific polymorphisms present in the HLA complex in the South African (SA) population reduces the probability of finding an adequate HLA-matched donor for individuals in need of an unrelated haematopoietic stem cell transplantation (HSCT). Next-generation sequencing (NGS) has numerous advantages compared with conventional typing techniques. To evaluate whether NGS can provide any additional value over conventional techniques in the SA context for the purpose of HSCT and cord blood banking. HLA genotyping was performed using NGS on 20 samples that had previously been HLA typed by conventional methods to evaluate whether NGS might provide any additional value over conventional HLA determination techniques. NGS of routinely sequenced loci and exons yielded accurate genotypes for 98.5% of the five loci of interest, compared with 98% when additional exons were included. The study shows that the additional value of NGS over conventional techniques is limited, and unless done on a large scale to reduce cost may not be appropriate in SA at this stage in the context of HSCT and cord blood banking.


Cancer-associated variants of human NQO1: impacts on inhibitor binding and cooperativity.
Human NAD(P)H quinone oxidoreductase (DT-diaphorase, NQO1) exhibits negative cooperativity towards its potent inhibitor, dicoumarol. Here, we addressed the hypothesis that the effects of the two cancer-associated polymorphisms (p.R139W and p.P187S) may be partly mediated by their effects on inhibitor binding and negative cooperativity. Dicoumarol stabilized both variants and bound with much higher affinity for p.R139W than p.P187S. Both variants exhibited negative cooperativity towards dicoumarol; in both cases, the Hill coefficient (h) was approximately 0.5 and similar to that observed with the wild-type protein. NQO1 was also inhibited by resveratrol and by nicotinamide. Inhibition of NQO1 by resveratrol was approximately 10,000-fold less strong than that observed with the structurally similar enzyme, NRH quinine oxidoreductase 2 (NQO2). The enzyme exhibited non-cooperative behaviour towards nicotinamide, whereas resveratrol induced modest negative cooperativity (h = 0.85). Nicotinamide stabilized wild-type NQO1 and p.R139W towards thermal denaturation but had no detectable effect on p.P187S. Resveratrol destabilized the wild-type enzyme and both cancer-associated variants. Our data suggest that neither polymorphism exerts its effect by changing the enzyme's ability to exhibit negative cooperativity towards inhibitors. However, it does demonstrate that resveratrol can inhibit NQO1 in addition to this compound's well-documented effects on NQO2. The implications of these findings for molecular pathology are discussed.


A review of the efficacy of selective serotonin reuptake inhibitors in obsessive-compulsive disorder.
Obsessive-compulsive disorder (OCD) is a chronic illness associated with substantial morbidity; it often requires long-term medication. The best-studied therapeutic agent in the treatment of this disorder is the tricyclic antidepressant clomipramine. Since other tricyclic antidepressants appear to lack efficacy in OCD, that of clomipramine has been linked to its potent effects on serotonin. Consequently, agents that selectively inhibit serotonin reuptake have been the focus of several large-scale, placebo-controlled studies of OCD. Their efficacy in OCD is the focus of our review. MEDLINE search (1966 to present) of OCD treatment with clomipramine or SSRI antidepressant medication using the key words obsessive-compulsive disorder, serotonin reuptake inhibitors, clomipramine, and pharmacology. The selective serotonin reuptake inhibitors fluoxetine, sertraline, fluvoxamine, and paroxetine have, in separate multicenter trials, demonstrated efficacy and tolerability in the treatment of OCD. In contrast, clomipramine, though efficacious, is often associated with substantial adverse events, particularly anticholinergic side effects. While 2 recent meta-analyses support the superior efficacy of clomipramine over selective serotonin reuptake inhibitors in the treatment of OCD, 5 of 6 head-to-head comparisons of either fluoxetine or fluvoxamine versus clomipramine have found similar efficacy but a lower incidence of side effects with the selective serotonin reuptake inhibitor. A recently completed multicenter, 12-week, double-blind trial of paroxetine versus clomipramine versus placebo showed paroxetine to be as effective as clomipramine. With significantly fewer dropouts due to adverse effects than clomipramine, paroxetine was also associated with superior tolerability. The suggestion that selective serotonin reuptake inhibitors possess efficacy similar to that of clomipramine, but have a superior side effect profile, may have important implications for patients with OCD who require long-term treatment.


Mechanical properties of the colon: comparison of the features of the African and European colon in vitro.
The tensile properties of the colon have been examined using methods which gave repeatable results. They showed little change after storage in salt for up to five weeks. The burst strength remained unchanged along the length of the colon. The tensile strength fell distally, as the thickness of the colonic wall increased. The width at burst decreased distally as did the internal diameter. The visco-elastic property of stress relaxation was constant in all regions. The tensile property of the colon was well developed at birth, but fell with age as did the width at burst and the internal diameter. Stress relaxation was unaffected. Because there may be a mechanical abnormality of the colonic wall in diverticular disease and as Europeans are prone to this condition while Africans are not commonly affected, European and African colons were compared. The tensile strength in a Kampala group was greater than in an Edinburgh one, but fell significantly in both groups with age. The width at burst was greater in the Kampala group, but also declined with age. Stress-relaxation was similar in both groups. In view of the similar properties in childhood of colons from Edinburgh and Kampala, the strength of the adult African compared with European colons may derive later from environmental factors such as diet. There were, however, no differences between the colons with and without diverticular disease in European subjects over the age of 50 years.


Concomitant parasitism: bancroftian filariasis and intestinal helminths and response to albendazole.
Subjects in an disease-endemic area in Orissa, India concomitantly infected with filariasis and intestinal helminths had significantly lower intensity of filarial infection in comparison with those who were infected only with filariasis. Administration of albendazole resulted in a significant decrease in the prevalence of filarial antigenemia in subjects concomitantly infected with intestinal helminths, but produced little change in this infection measure in subjects infected only with Wuchereria bancrofti. These results indicate that intestinal helminths could play a role in the anti-filarial activity of albendazole, most probably by depressing filarial infection intensity in co-infected individuals. Confirmation of these findings in a larger cohort may yield important new insights regarding the role of using albendazole in the ongoing intervention programs for the control of lymphatic filariasis.


BAR domains and membrane curvature: bringing your curves to the BAR.
BAR (bin, amphiphysin and Rvs161/167) domains are a unique class of dimerization domains, whose dimerization interface is edged by a membrane-binding surface. In its dimeric form, the membrane-binding interface is concave, and this gives the ability to bind better to curved membranes, i.e. to sense membrane curvature. When present at higher concentrations, the domain can stabilize membrane curvature, generating lipid tubules. This domain is found in many contexts in a wide variety of proteins, where the dimerization and membrane-binding function of this domain is likely to have a profound effect on protein activity. If these proteins function as predicted, then there will be membrane subdomains based on curvature, and thus there is an additional layer of compartmentalization on membranes. These and other possible functions of the BAR domain are discussed.


Systematic Assessment of Prosthesis Stiffness on User Biomechanics Using the Lower Leg Trajectory Error Framework and Its Implication for the Design and Evaluation of Ankle-Foot Prostheses.
Advances in understanding the effects the mechanical characteristics of prosthetic feet on user biomechanics have enabled passive prostheses to improve the walking pattern of people with lower limb amputation. However, there is no consensus on the design methodology and criteria required to maximize specific user outcomes and fully restore their mobility. The Lower Leg Trajectory Error (LLTE) framework is a novel design methodology based on the replication of lower leg dynamics. The LLTE value evaluates how closely a prosthetic foot replicates a target walking pattern. Designing a prosthesis that minimizes the LLTE value, optimizes its mechanical function to enable users to best replicate the target lower leg trajectory. Here, we conducted a systematic sensitivity investigation of LLTE-optimized prostheses. Five people with unilateral transtibial amputation walked overground at self-selected speeds using five prototype energy storage and return feet with varying LLTE values. The prototypes' LLTE values were varied by changing the stiffness of the participant's LLTE-optimized design by 60%, 80%, 120%, and 167%. Users most closely replicated the target able-bodied walking pattern with the LLTE-optimized stiffness, experimentally demonstrating that the predicted optimum was a true optimum. Additionally, the predicted LLTE values were correlated to the user's ability to replicate the target walking pattern, user preferences, and clinical outcomes including roll-over geometries, trunk sway, prosthetic energy return, and peak push-off power. This study further validates the use of the LLTE framework as a predictive and quantitative tool for designing and evaluating prosthetic feet.


Interaction of single viruslike particles with vesicles containing glycosphingolipids.
Glycosphingolipids are involved in the first steps of virus-cell interaction, where they mediate specific recognition of the host cell membrane. We have employed total-internal-reflection fluorescence microscopy to explore the interaction kinetics between individual unlabeled noroviruslike particles, which are attached to a glycosphingolipid-containing lipid bilayer, and fluorescent vesicles containing different types and concentrations of glycosphingolipids. Under association equilibrium, the vesicle-binding rate is found to be kinetically limited, yielding information on the corresponding activation energy. The dissociation kinetics are logarithmic over a wide range of time. The latter is explained by the vesicle-size-related distribution of the dissociation activation energy. The biological, pharmaceutical, and diagnostic relevance of the study is briefly discussed.


The SbSOS1 gene from the extreme halophyte Salicornia brachiata enhances Na(+) loading in xylem and confers salt tolerance in transgenic tobacco.
Soil salinity adversely affects plant growth and development and disturbs intracellular ion homeostasis resulting cellular toxicity. The Salt Overly Sensitive 1 (SOS1) gene encodes a plasma membrane Na(+)/H(+) antiporter that plays an important role in imparting salt stress tolerance to plants. Here, we report the cloning and characterisation of the SbSOS1 gene from Salicornia brachiata, an extreme halophyte. The SbSOS1 gene is 3774 bp long and encodes a protein of 1159 amino acids. SbSOS1 exhibited a greater level of constitutive expression in roots than in shoots and was further increased by salt stress. Overexpressing the S. brachiata SbSOS1 gene in tobacco conferred high salt tolerance, promoted seed germination and increased root length, shoot length, leaf area, fresh weight, dry weight, relative water content (RWC), chlorophyll, K(+)/Na(+) ratio, membrane stability index, soluble sugar, proline and amino acid content relative to wild type (WT) plants. Transgenic plants exhibited reductions in electrolyte leakage, reactive oxygen species (ROS) and MDA content in response to salt stress, which probably occurred because of reduced cytosolic Na(+) content and oxidative damage. At higher salt stress, transgenic tobacco plants exhibited reduced Na(+) content in root and leaf and higher concentrations in stem and xylem sap relative to WT, which suggests a role of SbSOS1 in Na(+) loading to xylem from root and leaf tissues. Transgenic lines also showed increased K(+) and Ca(2+) content in root tissue compared to WT, which reflect that SbSOS1 indirectly affects the other transporters activity. Overexpression of SbSOS1 in tobacco conferred a high degree of salt tolerance, enhanced plant growth and altered physiological and biochemical parameters in response to salt stress. In addition to Na(+) efflux outside the plasma membrane, SbSOS1 also helps to maintain variable Na(+) content in different organs and also affect the other transporters activity indirectly. These results broaden the role of SbSOS1 in planta and suggest that this gene could be used to develop salt-tolerant transgenic crops.


Molecular genetics of rheumatoid arthritis.
Following the successful determination of the molecular genetics of single-gene disorders, attention has not surprisingly turned to complex genetic disorders. However, preliminary experience suggests that unravelling the genetic component of common inflammatory disorders, such as rheumatoid arthritis, multiple sclerosis and systemic lupus erythematosus, might be a harder nut to crack.


Sperm swimming in the polychaete Galeolaria caespitosa shows substantial inter-individual variability in response to future ocean acidification.
The rapidity of ocean acidification intensifies selection pressure for resilient phenotypes, particularly during sensitive early life stages. The scope for selection is greater in species with greater within-species variation in responses to changing environments, thus enhancing the potential for adaptation. We investigated among-male variation in sperm swimming responses (percent motility and swimming speeds) of the serpulid polychaete Galeolaria caespitosa to near- (ΔpH -0.3) and far-future ocean acidification (ΔpH -0.5). Responses of sperm swimming to acidification varied significantly among males and were overall negative. Robust sperm swimming behavior under near-future ocean acidification in some males may ameliorate climate change impacts, if traits associated with robustness are heritable, and thereby enhance the potential for adaptation to far-future conditions. Reduced sperm swimming in the majority of male G. caespitosa may decrease their fertilization success in a high CO2 future ocean. Resultant changes in offspring production could affect recruitment success and population fitness downstream.


A comparison of the prevalence and risk factors of complications in intracranial tumor embolization between the Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and JR-NET3.
The Japanese Registry of NeuroEndovascular Therapy 2 (JR-NET2) and 3 (JR-NET3) were nationwide surveys that evaluated clinical outcomes after neuroendovascular therapy in Japan. The aim of this study was to compare the prevalence and risk factors of complications of intracranial tumor embolization between JR-NET2 and JR-NET3. A total of 1018 and 1545 consecutive patients with intracranial tumors treated with embolization were enrolled in JR-NET2 and JR-NET3, respectively. The prevalence of complications in intracranial tumor embolization and related risk factors were compared between JR-NET2 and JR-NET3. The prevalence of complications in JR-NET3 (3.69%) was significantly higher than that in JR-NET2 (1.48%) (p = 0.002). The multivariate analysis in JR-NET2 showed that embolization for tumors other than meningioma was the only significant risk factor for complication (odds ratio [OR], 3.88; 95% confidence interval [CI], 1.13-12.10; p = 0.032), and that in JR-NET3 revealed that embolization for feeders other than external carotid artery (ECA) (OR, 3.56; 95% CI, 2.03-6.25; p < 0.001) and use of liquid materials (OR, 2.65; 95% CI, 1.50-4.68; p < 0.001) were significant risks for complications. The frequency of embolization for feeders other than ECA in JR-NET3 (15.3%) was significantly higher than that in JR-NET2 (9.2%) (p < 0.001). Also, there was a significant difference in the frequency of use of liquid materials between JR-NET2 (21.2%) and JR-NET3 (41.2%) (p < 0.001). Embolization for feeders other than ECA and use of liquid materials could increase the complication rate in intracranial tumor embolization.


The role of spirituality in spinal cord injury (SCI) rehabilitation: exploring health professional perspectives.
Descriptive, qualitative study. To explore the perspectives of health professionals (HPs) regarding the role of spirituality in spinal cord injury (SCI) rehabilitation. Single centre rehabilitation hospital, NSW, Australia. Two focus groups (n = 12) were conducted with HPs (e.g., nursing, allied health, medical) working in SCI inpatient rehabilitation. A semi-structured interview was employed, consisting of questions about spirituality and its role in SCI rehabilitation. The groups were audio recorded and transcribed. An inductive thematic analysis was conducted. Six themes were identified from the focus group data: (i) the meaning of spirituality; (ii) spirituality as a help; (iii) spirituality as a hindrance; (iv) how spirituality is indirectly addressed in practice; (v) perceived barriers to incorporating spirituality into practice; (vi) how spirituality can be better integrated into practice. HPs recognised that spirituality played an important role in the adjustment of many individuals and their families after SCI. However, spirituality was not proactively addressed during SCI rehabilitation, and most often arose during informal interactions with clients. Spirituality, and specifically religious belief, was perceived to sometimes raise difficulties for clients and staff. The use of physical space and a review of rehabilitation processes were suggested by HPs as two ways spirituality could be better incorporated into practice. The findings of this study reveal that spiritual needs of clients and their family members during SCI rehabilitation are important and could be better addressed. A range of initiatives are proposed, including staff training and the use of standardised spiritual assessment tools.


Electron transport in molecular wire junctions.
Molecular conductance junctions are structures in which single molecules or small groups of molecules conduct electrical current between two electrodes. In such junctions, the connection between the molecule and the electrodes greatly affects the current-voltage characteristics. Despite several experimental and theoretical advances, including the understanding of simple systems, there is still limited correspondence between experimental and theoretical studies of these systems.


Inhibition of class A and class C beta-lactamases by penems: crystallographic structures of a novel 1,4-thiazepine intermediate.
A new beta-lactamase inhibitor, a methylidene penem having a 5,6-dihydro-8H-imidazo[2,1-c][1,4]oxazine heterocyclic substituent at the C6 position with a Z configuration, irreversibly inhibits both class A and class C serine beta-lactamases with IC(50) values of 0.4 and 9.0 nM for TEM-1 and SHV-1 (class A), respectively, and 4.8 nM in AmpC (class C) beta-lactamases. The compound also inhibits irreversibly the class C extended-spectrum GC1 beta-lactamase (IC(50) = 6.2 nM). High-resolution crystallographic structures of a reaction intermediate of (5R)-(6Z)-6-(5,6-dihydro-8H-imidazo[2,1-c][1,4]oxazin-2-ylmethylene)-7-oxo-4-thia-1-azabicyclo[3.2.0]hept-2-ene-3-carboxylic acid 1 with the SHV-1 beta-lactamase and with the GC1 beta-lactamase have been determined by X-ray diffraction to resolutions of 1.10 and 1.38 A, respectively. The two complexes were refined to crystallographic R-factors (R(free)) of 0.141 (0.186) and 0.138 (0.202), respectively. Cryoquenching of the reaction of 1 with each beta-lactamase crystal produced a common, covalently bound intermediate. After acylation of the serine, a nucleophilic attack by the departing thiolate on the C6' atom yielded a novel seven-membered 1,4-thiazepine ring having R stereochemistry at the new C7 moiety. The orientation of this ring in each complex differs by a 180 degrees rotation about the bond to the acylated serine. The acyl ester bond is stabilized to hydrolysis through resonance stabilization with the dihydrothiazepine ring and by low occupancy or disorder of hydrolytic water molecules. In the class A complex, the buried water molecule on the alpha-face of the ester bond appears to be loosely bound or absent. In the class C complex, a water molecule on the beta-face is disordered and poorly activated for hydrolysis. Here, the acyl intermediate is unable to assist its own hydrolysis, as is thought to occur with many class C substrates.


An unconventional nuclear localization motif is crucial for function of the Drosophila Wnt/wingless antagonist Naked cuticle.
Wnt/beta-catenin signals orchestrate cell fate and behavior throughout the animal kingdom. Aberrant Wnt signaling impacts nearly the entire spectrum of human disease, including birth defects, cancer, and osteoporosis. If Wnt signaling is to be effectively manipulated for therapeutic advantage, we first must understand how Wnt signals are normally controlled. Naked cuticle (Nkd) is a novel and evolutionarily conserved inducible antagonist of Wnt/beta-catenin signaling that is crucial for segmentation in the model genetic organism, the fruit fly Drosophila melanogaster. Nkd can bind and inhibit the Wnt signal transducer Dishevelled (Dsh), but the mechanism by which Nkd limits Wnt signaling in the fly embryo is not understood. Here we show that nkd mutants exhibit elevated levels of the beta-catenin homolog Armadillo but no alteration in Dsh abundance or distribution. In the fly embryo, Nkd and Dsh are predominantly cytoplasmic, although a recent report suggests that vertebrate Dsh requires nuclear localization for activity in gain-of-function assays. While Dsh-binding regions of Nkd contribute to its activity, we identify a conserved 30-amino-acid motif, separable from Dsh-binding regions, that is essential for Nkd function and nuclear localization. Replacement of the 30-aa motif with a conventional nuclear localization sequence rescued a small fraction of nkd mutant animals to adulthood. Our studies suggest that Nkd targets Dsh-dependent signal transduction steps in both cytoplasmic and nuclear compartments of cells receiving the Wnt signal.


A newly discovered TSHR variant (L665F) associated with nonautoimmune hyperthyroidism in an Austrian family induces constitutive TSHR activation by steric repulsion between TM1 and TM7.
New in vivo mutations in G protein-coupled receptors open opportunities for insights into the mechanism of receptor activation. Here we describe the molecular mechanism of constitutive TSH receptor (TSHR) activation in an Austrian family with three generations of familial nonautoimmune hyperthyroidism. The index patient was diagnosed with hyperthyroidism during her first pregnancy. Her first two children were diagnosed with hyperthyroidism at the age of 11 and 10 years, respectively. TSH suppression was also observed in the third child at the age of 8 years, who has normal free T4 levels until now. TSH suppression in infancy was observed in the fourth child. The mother of the index patient was diagnosed with toxic multinodular goiter at the age of 36 years. DNA was extracted from blood samples from the index patient, her mother, and her four children. Screening for TSHR mutations was performed by high-resolution melting assays and subsequent sequencing. Elucidation of the underlying mechanism of TSHR activation was carried out by generation and structural analysis of TSHR transmembrane homology models and verification of model predictions by functional characterization of receptor mutations. A newly discovered TSHR mutation L665F in transmembrane helix 7 of the receptor was detected in six members of this family. Functional characterization of L665F revealed constitutive activation for the Gs pathway and thus represents the molecular cause for hyperthyroidism in this family. The constitutive activation is possibly linked to a steric clash introduced by the L665F mutation between transmembrane helices 1 and 7.


In vivo imaging of human and mouse skin with a handheld dual-axis confocal fluorescence microscope.
Advancing molecular therapies for the treatment of skin diseases will require the development of new tools that can reveal spatiotemporal changes in the microanatomy of the skin and associate these changes with the presence of the therapeutic agent. For this purpose, we evaluated a handheld dual-axis confocal (DAC) microscope that is capable of in vivo fluorescence imaging of skin, using both mouse models and human skin. Individual keratinocytes in the epidermis were observed in three-dimensional image stacks after topical administration of near-infrared (NIR) dyes as contrast agents. This suggested that the DAC microscope may have utility in assessing the clinical effects of a small interfering RNA (siRNA)-based therapeutic (TD101) that targets the causative mutation in pachyonychia congenita (PC) patients. The data indicated that (1) formulated indocyanine green (ICG) readily penetrated hyperkeratotic PC skin and normal callused regions compared with nonaffected areas, and (2) TD101-treated PC skin revealed changes in tissue morphology, consistent with reversion to nonaffected skin compared with vehicle-treated skin. In addition, siRNA was conjugated to NIR dye and shown to penetrate through the stratum corneum barrier when topically applied to mouse skin. These results suggest that in vivo confocal microscopy may provide an informative clinical end point to evaluate the efficacy of experimental molecular therapeutics.


Index-of-refraction sensors: virtually unlimited sensing power at the critical angle.
In an effort to improve and simplify refractive index sensors, we identified a basic operation mode at the critical angle. Sensitivity to the refractive index is higher than in standard surface plasmon resonance sensors, and we have been able to demonstrate analytically that it is virtually an unbounded value. We describe this approach and submit a complete analytical study demonstrating its unlimited sensing power. To test the approach, we constructed an economical and basic sensor. Despite its simplicity, we demonstrated the discrimination capability to be of the order of 10(-6), as far as we know close to the best sensitivity ever recorded. This detection method is generally applicable to any optical system and may pave the way for the next generation of optical sensing devices.


Bench-to-bedside review: the value of cardiac biomarkers in the intensive care patient.
The use of cardiac biomarkers in the intensive care setting is gaining increasing popularity. There are several reasons for this increase: there is now the facility for point-of-care biomarker measurement providing a rapid diagnosis; biomarkers can be used as prognostic tools; biomarkers can be used to guide therapy; and, compared with other methods such as echocardiography, the assays are easier and much more affordable. Two important characteristics of the ideal biomarker are disease specificity and a linear relationship between the serum concentration and disease severity. These characteristics are not present, however, in the majority of biomarkers for cardiac dysfunction currently available. Those clinically useful cardiac biomarkers, which naturally received the most attention, such as troponins and B-type natriuretic peptide, are not as specific as was originally thought. In the intensive care setting, it is important for the user to understand the degree of specificity of these biomarkers and that the interpretation of the results should always be guided by other clinical information. The present review summarizes the available biomarkers for different cardiac conditions. Potential biomarkers under evaluation are also briefly discussed.


Evolution and revolution as organizations grow. 1972.
The influence of history on an organization is a powerful but often overlooked force. Managers, in their haste to build companies, frequently fail to ask such critical developmental questions as, Where has our organization been? Where is it now? and What do the answers to these questions mean for where it is going? Instead, when confronted with problems, managers fix their gaze outward on the environment and toward the future, as if more precise market projections will provide the organization with a new identity. In this HBR Classic, Larry Greiner identifies a series of developmental phases that companies tend to pass through as they grow. He distinguishes the phases by their dominant themes: creativity, direction, delegation, coordination, and collaboration. Each phase begins with a period of evolution, steady growth, and stability, and ends with a revolutionary period of organizational turmoil and change. The critical task for management in each revolutionary period is to find a new set of organizational practices that will become the basis for managing the next period of evolutionary growth. Those new practices eventually outlast their usefulness and lead to another period of revolution. Managers therefore experience the irony of seeing a major solution in one period become a major problem in a later period. Originally published in 1972, the article's argument and insights remain relevant to managers today. Accompanying the original article is a commentary by the author updating his earlier observations.


Meteorite nanoparticles as models for interstellar grains: synthesis and preliminary characterisation.
Dust particles and their interaction with gases play important roles in star formation and in solar nebulae. Appropriate model dust grains are needed for the laboratory simulation of gas-grain interactions. Nanoparticles formed from carbonaceous meteorites may be particularly suitable, as these particles are formed from materials that were formed originally from interstellar/nebula dust. Extending our previous studies with grounded meteorite powders, we demonstrate here the production of nanoparticles formed from meteorites using the laser desorption/controlled condensation method developed in our laboratory. The product nanoparticle aggregates have porous, web-like morphologies similar to interstellar dust grains, indicating that they can present large specific surface areas for gas/grain interactions. In this paper, we present polarisation modulation reflection-absorption infrared spectra (PM-RAIRS) of supported thin films and compare these spectra with the known silicate bands in the spectra of interstellar dust recorded during the ISO mission. We also report an ultrahigh vacuum (UHV) temperature programmed desorption (TPD) study of the adsorption of CO on the supported nanoparticle films. The latter allow us to estimate the CO binding energy on the meteorite nanoparticles as 13.5 +/- 3.0 kJ mol(-1), cf. a value of 9.8 +/- 0.2 kJ mol(-1) for CO binding to a water ice substrate. Such thermochemical data can be useful for computational modelling of gas-grain interactions under the diverse conditions in interstellar clouds and solar nebulae.


Stereocomplexes of Discrete, Isotactic Lactic Acid Oligomers Conjugated with Oligodimethylsiloxanes.
Discrete length block co-oligomers (BCOs) comprised of a crystalline and an amorphous block are a new class of materials that gives highly ordered lamellar morphologies at small length scales. Here, we show the preparation of discrete, isotactic oligo l- and d-lactic acid (olLA and odLA) homoblocks followed by ligation to oligodimethylsiloxane (oDMS), affording a library of crystalline-amorphous BCOs that vary in molecular weight and composition. Mixing the two enantiomeric BCOs or homoblocks results in the formation of the corresponding stereocomplex. The properties and phase behavior of the isotactic (block co)oligomers and the stereocomplexes thereof are studied using differential scanning calorimetry and small-angle X-ray scattering. A systematic study of the isotactic homoblock lengths and crystal structure confirmed the formation of a 103 helix with a monomeric rise of 0.3 nm, whereas the stereocomplex adopts a 31 helix. The same type of crystal structure was found for the isotactic and stereocomplex of BCOs giving rise to the formation of lamellar morphologies at room temperature as a result of crystallization of the oLA blocks. Distorted lamellar structures were found in BCOs that preorganize into nonlamellar morphologies prior to crystallization. The stereocomplex BCOs shows more crystal defects and a loss of long-range ordering in the microstructure due to the larger driving force for crystallization. Hence, the balance between chain length, block volume, and the crystallization strength are of major importance for the formation of the final structure with the least defects.


A high loading dose of clopidogrel reduces myocardial infarct size in patients undergoing primary percutaneous coronary intervention: a magnetic resonance imaging study.
We sought to determine whether a 600-mg loading dose of clopidogrel reduces myocardial infarct size compared with a 300-mg dose using contrast-enhanced magnetic resonance imaging in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). In 198 patients undergoing primary PCI for STEMI, contrast-enhanced magnetic resonance imaging was performed a median of 7 days after the index event. Infarct size was measured on delayed-enhancement imaging, and area at risk (AAR) was quantified on T2-weighted images. Baseline characteristics were not significantly different between the 600-mg clopidogrel loading group (n = 117) and the 300-mg group (n = 81). The median infarct size was significantly smaller in the 600-mg group than in the 300-mg group (17.3% [8.9%-26.2%] vs 21.7% [12.9%-30.0%], P = .03). Myocardial salvage index ([AAR - infarct size] × 100/AAR) was greater in the 600-mg group than in the 300-mg group (47.7 [33.7-60.9] vs 32.0 [23.6-51.5], P < .01). Patients in the 600-mg group also had a significantly lower extent of microvascular obstruction and smaller number of segments with >75% of infarct transmurality than did those in the 300-mg group. After propensity score matching, the 600-mg group had smaller infarct size and greater myocardial salvage index compared with the 300-mg group. In multivariate analysis, the use of a 600-mg clopidogrel loading dose significantly reduced the risk of a large infarct (odds ratio 0.53, 95% CI 0.29-0.98, P = .04). In patients undergoing primary PCI for STEMI, a 600-mg loading dose of clopidogrel reduced myocardial infarct size and improved myocardial salvage compared with a 300-mg loading dose.


Measuring diffusion limitation with a perfusion-limited gas--hyperpolarized 129Xe gas-transfer spectroscopy in patients with idiopathic pulmonary fibrosis.
Although xenon is classically taught to be a "perfusion-limited" gas, (129)Xe in its hyperpolarized (HP) form, when detected by magnetic resonance (MR), can probe diffusion limitation. Inhaled HP (129)Xe diffuses across the pulmonary blood-gas barrier, and, depending on its tissue environment, shifts its resonant frequency relative to the gas-phase reference (0 ppm) by 198 ppm in tissue/plasma barrier and 217 ppm in red blood cells (RBCs). In this work, we hypothesized that in patients with idiopathic pulmonary fibrosis (IPF), the ratio of (129)Xe spectroscopic signal in the RBCs vs. barrier would diminish as diffusion-limitation delayed replenishment of (129)Xe magnetization in RBCs. To test this hypothesis, (129)Xe spectra were acquired in 6 IPF subjects as well as 11 healthy volunteers to establish a normal range. The RBC:barrier ratio was 0.55 ± 0.13 in healthy volunteers but was 3.3-fold lower in IPF subjects (0.16 ± 0.03, P = 0.0002). This was caused by a 52% reduction in the RBC signal (P = 0.02) and a 58% increase in the barrier signal (P = 0.01). Furthermore, the RBC:barrier ratio strongly correlated with lung diffusing capacity for carbon monoxide (DLCO) (r = 0.89, P < 0.0001). It exhibited a moderate interscan variability (8.25%), and in healthy volunteers it decreased with greater lung inflation (r = -0.78, P = 0.005). This spectroscopic technique provides a noninvasive, global probe of diffusion limitation and gas-transfer impairment and forms the basis for developing 3D MR imaging of gas exchange.


Evaluating the feasibility, fidelity, and preliminary effectiveness of a school-based intervention to improve the school participation and feelings of connectedness of elementary school students on the autism spectrum.
In My Shoes is a peer supported, teacher-led, school-based intervention that aims to improve the school participation and connectedness of students on the autism spectrum. The aim of this study was to explore the feasibility, fidelity, and preliminary effectiveness of In My Shoes in mainstream elementary schools. Ten Grade 3 and 4 students on the autism spectrum and 200 of their typically developing peers across eight classrooms and six schools participated. The following aspects of feasibility were explored: recruitment capability and sample characteristics, data collection procedures and outcome measures, appropriateness, implementation, and practicality of the intervention. Fidelity was explored by evaluating the delivery of intervention components against set criteria. Preliminary effectiveness was investigated by evaluating changes in intervention outcomes pre-post intervention using a range of outcome measures. Study findings are encouraging, suggesting In My Shoes is a feasible and appropriate intervention, and shows promise in improving the self-report school engagement of all student participants, as well the classroom participation and subjective school experiences of students on the autism spectrum. Useful insights into ways the intervention and the design of future research can be improved are discussed.