United States Department of the Army

About: United States Department of the Army is a government organization based out in Arlington, Virginia, United States. It is known for research contribution in the topics: Poison control & Population. The organization has 32668 authors who have published 42453 publications receiving 947075 citations. The organization is also known as: DA & U.S. Department of the Army.

The effect of strain rate and heat developed during deformation on the stress-strain curve of plastics

Abstract: Polymethylmethacrylate, cellulose acetate butyrate, polypropylene and nylon 6–6 have been characterized in compression at various strain rates from 10−4 s−1 to 103 s−1 at room temperature. A medium strain-rate machine and a split-Hopkinson-bar apparatus are used in conducting the experiments. The temperature rise developed during deformation is also measured by using a thermocouple. All four materials tested definitely show a viscous effect at the beginning of the deformation and a plastic flow follows thereafter. Test results also indicate that the temperature rise developed during deformation cannot be neglected in determining the dynamic response of those materials investigated in this study.

Desmoplastic malignant melanoma

Abstract: Background: Desmoplastic malignant melanoma (DMM) is an uncommon variant of malignant melanoma and often is difficult to diagnose. Because of the relative rarity of this tumor, it has not been well studied and controversy remains concerning its biologic potential. Objective: We compared survival rates of DMM with those of other malignant melanomas and determined what clinical and/or histologic features, if any, correlated with survival. Methods: The files of the Armed Forces Institute of Pathology were searched for cases of DMM or related tumors with adequate material for further histologic and immunohistochemical evaluation. Follow-up on each patient was requested from the pathologist, clinician, and/or the patient. The follow-up was correlated with the histologic findings in each case. The relationship of histologic features to disease-free survival was evaluated. Results: Adequate material for evaluation was available in 128 cases. The overall histologic features were similar to those previously reported. Immunohistochemical studies showed that all lesions were negative for HMB-45, a marker for premelanosomes. Factors that correlated with survival included tumor location, sex, tumor depth, and the presence of stromal mucin. The 5-year disease-free survival rate was 68% for all cases and 61% for lesions more than 4 mm deep. Conclusion: With a 5-year disease-free survival rate of 61%, DMM has a significantly better prognosis than other melanomas that have a 5-year disease-free survival rates of 40% to 41%. This may be related to neural differentiation of these tumors.

A New Primaquine Analogue, Tafenoquine (WR 238605), for Prophylaxis against Plasmodium falciparum Malaria

Abstract: We tested tafenoquine (WR 238605), a new long-acting 8-aminoquinoline, for its ability to prevent malaria in an area that is holoendemic for Plasmodium falciparum. In a double-blinded, placebo-controlled, randomized clinical trial in western Kenya, adult volunteers received a treatment course of 250 mg halofantrine per day for 3 days, to effect clearance of preexisting parasites. The volunteers were then assigned to 1 of 4 drug regimens: placebo throughout; 3 days of 400 mg (base) of tafenoquine per day, followed by placebo weekly; 3 days of 200 mg of tafenoquine per day, followed by 200 mg per week; and 3 days of 400 mg of tafenoquine per day, followed by 400 mg per week. Prophylaxis was continued for up to 13 weeks. Of the evaluable subjects (223 of 249 randomized subjects), volunteers who received 400 mg tafenoquine for only 3 days had a protective efficacy of 68% (95% confidence interval [CI], 53%-79%), as compared with placebo recipients; those who received 200 mg per day for 3 days followed by 200 mg per week had a protective efficacy of 86% (95% CI, 73%-93%); and those who received 400 mg for 3 days followed by 400 mg per week had a protective efficacy of 89% (95% CI, 77%-95%). A similar number of volunteers in the 4 treatment groups reported adverse events. Prophylactic regimens of 200 mg or 400 mg of tafenoquine, taken weekly for < or =13 weeks, are highly efficacious in preventing falciparum malaria and are well tolerated.