The most comprehensive search for organics in the Martian soil was performed by the Viking Landers. Martian soil was subjected to a thermal volatilization process to vaporize and break organic molecules, and the resultant gases and volatiles were analyzed by gas chromatography‐mass spectrometry. Only water at 0.1–1.0 wt% was detected, with traces of chloromethane at 15 ppb, at Viking landing site 1, and water at 0.05–1.0 wt% and carbon dioxide at 50–700 ppm, with traces of dichloromethane at 0.04–40 ppb, at Viking landing site 2. These chlorohydrocarbons were considered to be terrestrial contaminants, although they had not been detected at those levels in the blank runs. Recently, perchlorate was discovered in the Martian Arctic soil by the Phoenix Lander. Here we show that when Mars‐like soils from the Atacama Desert containing 32 ± 6 ppm of organic carbon are mixed with 1 wt% magnesium perchlorate and heated, nearly all the organics present are decomposed to water and carbon dioxide, but a small amount is chlorinated, forming 1.6 ppm of chloromethane and 0.02 ppm of dichloromethane at 500°C. A chemical kinetics model was developed to predict the degree of oxidation and chlorination of organics in the Viking oven. Reinterpretation of the Viking results therefore suggests ≤0.1% perchlorate and 1.5–6.5 ppm organic carbon at landing site 1 and ≤0.1% perchlorate and 0.7–2.6 ppm organic carbon at landing site 2. The detection of organics on Mars is important to assess locations for future experiments to detect life itself.

No abstract

Taenia crassiceps has been widely experimented as a model for in vitro and in vivo studies on drug responses. The purpose of this study was to treat BALB/c mice infected with T. crassiceps strain WFU with commercially available albendazole and to analyze the reduction in parasite infrapopulations. Here, we describe the reduction and apparent damage of T. crassicceps WFU cysticerci in infected mice after antihelminthic drug treatment and subsequent inoculation of those treated parasites into a naïve host. We were able to reduce significantly the parasite counts to 33 and 48% after albendazole treatment for 20 or 25 days and compared with the untreated mice. We also observed morphological damage such as the partial blebbing in the tegument and parenchyma of treated parasites, as well as disorganized musculature and the loss of cell membranes in subtegumental tissue section. However, larvae from albendazole-treated mice inoculated into the next host were able to become re-established in the next murine host due, probably, to the survival of proliferative parasite cells.

No abstract

Con el propósito de observar el efecto del diazepam sobre el proceso de cambio emocional que presenta la respuesta de sacudirse, se realizó una investigación mayor, de la cual presentamos el avance correspondiente al segundo ensayo para observar el efecto postdosis de 0.5 mg/Kg de diazepam, 24 horas después de su administración aguda. Se utilizaron 14 ratas machos Wistar experimentalmente ingenuas. Se formaron aleatoriamente dos grupos de siete miembros cada uno, grupo control y grupo experimental, El E2 se realizó 24 horas después del E1, en el que había sido administrada la dosis de diazepam. Se advirtieron diferencias entre los grupos control y grupo postdosis, los lapsos del grupo postdosis presentaron una media de respuesta siempre menor que el grupo control, lo que sugiere que hay un efecto postdosis del diazepam, observable 24 horas después.