<qa>  What is the best dose of 3-AP?This phase I trial is studying the best dose of 3-AP and the side effects of giving 3-AP together with gemcitabine in treating patients with advanced solid tumors or lymphoma. Drugs used in chemotherapy, such as 3-AP and gemcitabine GEM, work in different ways to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. 3-AP may help gemcitabine kill more cancer cells by making the cells more sensitive to the drug. 3-AP may also stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. 