Search results for "Toxic substance"
showing 4 items of 4 documents
The Structure and the Stereochemistry of Atractyliretin
1986
The nor-kaurane diterpene Atractyliretin was obtained by acid hydrolysis of Atractyloside, a toxic substance isolated from ATRACTYLIS GUMMIFERA L (Compositae). On the basis of spectral (IR, (1)H-NMR, (13)C-NMR and MS) analysis and chemical degradation its structure and stereochemistry was identified as 4.
La biomonitorización de sustancias tóxicas en muestras biológicas de población general
2016
ResumenLa biomonitorización de sustancias tóxicas ha sido incorporada por buena parte de los países más desarrollados, con el objetivo de conocer sus concentraciones en muestras biológicas. Estas sustancias se incorporan al organismo por medio de diferentes exposiciones ambientales. La vigilancia en muestras biológicas debe permitir conocer sus valores en grupos vulnerables y su evolución en el tiempo, comparar con los valores observados en otros países, identificar grupos que presenten valores altos o de riesgo, y promover la investigación. Su finalidad más clara es la de servir como instrumento para el diseño de políticas que permitan poner en marcha medidas de actuación en diversos secto…
Coping with Oxygen
2010
Sometime before 2.7 BYA, a new and biologically toxic substance began to appear in the environment. Biologically produced dioxygen, O2, probably first began to accumulate in small pools or layers above cyanobacterial mats. These photosynthesizers must have already developed ways to at least partially deal with dioxygen and, with greater difficulty, the reactive oxygen species (ROS) derived from it (see Chap. 1 and below). But for primitive anaerobes in the vicinity, these new substances must have been especially toxic. Nevertheless, it is clear that they evolved ways to cope with the new threats. One way was to simply avoid dioxygen altogether.
Common etiological pathways between toxic substance use, Internet and cybersex addiction: The role of expectancies and antisocial deviance proneness
2016
This study examined Internet and cybersex addiction in adolescents and how such behaviour was associated with substance use (in particular, cigarettes, alcohol, and drug use). Participants were 312 adolescents, aged 14-16, who completed survey instruments. Study measures included demographic, toxic substance use, expectancies toward substances consumption, antisocial deviance proneness, Internet, and cybersex addiction variables. Descriptive, bivariate analyses, exploratory/confirmatory factor analyses, and structural Equation Modeling were performed. Nearly 60%, 26%, and 25% of adolescents reported having drunk alcohol, used drugs and smoked cigarettes respectively. Prevalence of Internet …