Strategies and Tactics for Site Specific Deuterium Incorporation at Each Available Carbon Atom of α-Pinene.

The development of several unique strategies and tactics for the synthesis of α-pinene isotopologues that has culminated in access to all eight possible isomers with deuterium incorporated selectively at each available carbon atom is described. Access to this library of isotopologues provides new tools to more fully investigate the atmospheric autoxidation of α-pinene, a complex process that plays a major role in the formation of secondary organic aerosol in the Earth's atmosphere.

Therapeutic effect of implanted and non-invasive vagus nerve stimulation on heroin-induced anxiety.

Substance addiction causes anxiety, which in turn reinforces the maintaining of substance use, resulting in a vicious circle. And this circle is one of the reasons why addiction is so hard to cure. However, there is no treatment involved in addiction-induced anxiety at present. We tested whether VNS (vagus nerve stimulation) can improve heroin-induced anxiety, and made a comparison between nVNS (transcervical vagus nerve stimulation) and taVNS (transauricular vagus nerve stimulation) on therapeutic effect. Mice were subjected to nVNS or taVNS before heroin administration. By observing c-Fos expression in the NTS (nucleus of the solitary tract), we assessed vagal fiber activation. Using the OFT (open field test) and the EPM (elevated cross maze test), we evaluated the anxiety-like behaviors of the mice. Using immunofluorescence, we observed the proliferation and activation of microglia in the hippocampus. And ELISA was used to measure the levels of proinflammatory factors in the hippocampus. Both nVNS and taVNS significantly increased the expression of c-Fos in the nucleus of solitary tract, suggesting the feasibility of nVNS and taVNS. The anxiety level of heroin-treated mice was significantly increased, microglia in the hippocampus was significantly proliferated and activated, and the proinflammatory factors (IL-1ß, IL-6, TNF-α) in the hippocampus were significantly up-regulated. Crucially, both nVNS and taVNS reversed the above changes caused by heroin addiction. SIGNIFICANCE: It was confirmed that the therapeutic effect of VNS on heroin-induced anxiety may be an effective treatment method to break the "addiction-anxiety" cycle and provides some insights for subsequent treatment of addiction.

Recent developments in catalytic cross-couplings with unsaturated carboxylates.

Catalytic cross-couplings through C-O bond-cleavage of unsaturated carboxylates with organometallics have emerged as a powerful method for sustainable syntheses. Over the last decade, remarkable achievements have been made with the development of transition metal-catalyzed cross-couplings with the readily available phenol and enol derivatives as suitable coupling electrophiles beyond unsaturated halides. Therefore, this perspective describes the recent advances in the field of transition metal-catalyzed C-O bond activation of unsaturated carboxylates with organometallics, including B, Mg, Zn, Al, and Si reagents, until May 2021.

Csp3-H monofluoroalkenylation via stereoselective C-F bond cleavage.

A practical nickel- and photoredox-catalyzed Csp3-H monofluoroalkenylation through chelation-assisted Csp2-F bond cleavage of gem-difluoroalkenes for the synthesis of stereodefined tetrasubstituted fluoroalkenes has been developed. Moreover, the gem-difluoroalkenes can also undergo photoredox-catalyzed cascade twofold C-F diaminomethylation.

Reported reasons for initiating drug use among drug-dependent adolescents and youths in Yunnan, China.

BACKGROUND: As an entry point for illicit drug trafficking, Yunnan was hit hard by the twin epidemics of drug abuse and HIV/AIDS. There are no empirical studies regarding the reasons for initiation of drug use in Yunnan. OBJECTIVES: The study investigated the reasons for initiating drug use in drug-dependent adolescents and youths in five regions in Yunnan. METHODS: The data were collected in 2004-2005 from a stratified random sample of 467 registered drug addicts under age 25. Pearson chi-square tests were used to analyze the association of reasons for drug use with sociodemographic factors, knowledge of drug related harm, and access to illicit drugs. RESULTS: Curiosity was the most commonly reported reason for initiating drug use and the majority of the respondents reported having little or no knowledge of drug-related harm. The majority of the drug abusers initiated drug use at the age of 13-14 years or younger. CONCLUSIONS: There is a potential for sustained educational programs to reduce the high prevalence of adolescent drug use in Yunnan. SCIENTIFIC SIGNIFICANCE: This is the first empirical study that has investigated reasons for initiating drug use based on a random sample of registered drug users in a high risk province of China.

Societal perception and support for methadone maintenance treatment in a Chinese province with high HIV prevalence.

Methadone maintenance treatment (MMT) was first piloted in April 2004 in Yunnan, China, to reduce HIV transmission. This study aimed to examine public support for MMT and was based on cross-sectional data collected in March-April 2006 on a random sample of 411 police staff, medical/health professionals, community members, and drug users. Multivariate logistic regressions were used to analyze the data. The support was the strongest amongst the police and medical professionals but the lowest in drug users. A considerable proportion of the respondents viewed MMT as contradictory to China's drug control policies and this factor was negatively associated with support for MMT. Dissemination of more accurate knowledge and the resolution of these conflicts are urgently needed to increase the public support for MMT.