A UHPLC-MS/MS method for simultaneous determination of twelve constituents from Erigeron breviscapus extract in rat plasma: Application to a pharmacokinetic study.

A rapid, sensitive and specific ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated to simultaneously determine the twelve major bioactive ingredients (neochlorogenic acid, chlorogenic acid, caffeic acid, cynarin, scopoletin, scutellarin, isochlorogenic acid A, apigenin-7-o-glucuronide, isochlorogenic acid C, scutellarein, luteolin, and apigenin) in rat plasma. Gallic acid and wogonoside were used as internal standards (IS1 and IS2). The plasma samples were pretreated and extracted by liquid-liquid extraction and protein precipitation with ethyl acetate-acetonitrile (95:5, v/v).

Simultaneous determination and pharmacokinetic study of eight components in rat plasma by UHPLC-MS/MS after oral administration of Hypericum japonicum Thunb extract.

A rapid and sensitive assay based on ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was established and validated for the simultaneous determination of gallic acid, protocatechuic acid, vanillic acid, caffeic acid, epicatechin, isoquercitrin, vincetoxicoside B and quercetin in rat plasma using catechin and daidzein as the internal standards (IS). Plasma samples added internal standards were acidified with formic acid then pretreated by direct protein precipitation with acetonitrile. The separation of eight constituents was achieved on a C18 column with gradient elution using methanol and 0.

Female sex workers and their gatekeepers in China: implications for HIV/STI prevention.

Female sex workers (FSWs) play a key role in HIV/AIDS transmission and their gatekeepers play a crucial role in shaping their behaviors. Limited studies are available on the relationship between FSWs and gatekeepers. In the current study we used an ethnographic approach to examine the dynamic and multidimensional relationship of FSWs and their gatekeepers from the perspectives of both parties.

HIV pre-exposure prophylaxis interest among female sex workers in Guangxi, China.

Objectives: Acceptability of pre-exposure prophylaxis (PrEP) and willingness to participate in a clinical trial for both safety and efficacy of PrEP were investigated among female sex workers (FSWs) in Guangxi, China.

Methods: A cross-sectional study was performed in three cities in Guangxi. Structured, self-administered questionnaires were used to assess the acceptability of PrEP and the willingness to participate in a clinical trial.