Background: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women. The data on this syndrome in a Chinese community are limited. Methods: A community-based cross-sectional survey was undertaken. Cluster-randomized sampling was used. Female residents of Chengdu aged between 12 and 44 were included according to the constituent ratio of the female population of Sichuan province. We used three diagnostic criteria to determine the prevalence: the National Institutes of Health diagnostic criteria of PCOS (NIH-1990), the revised Rotterdam diagnostic criteria of PCOS (Rott-2003), and the recommended diagnostic criteria of PCOS by the Androgen Excess Society (AES-2006). Results: 1,645 participants were included. The prevalence of PCOS in women aged between 12 and 44 was 7.1, 11.2 and 7.4%, respectively, according to the three different criteria. After the onset of puberty, the prevalence of PCOS increased rapidly from 12 to 14 years of age, peaked between 15 and 24 and decreased gradually thereafter and reached its lowest point before menopause. Conclusions: The prevalence of PCOS in this study was in the PCOS prevalence range from existing studies. According to the trend of prevalence, PCOS might be a temporary condition.

The first redox neutral decarboxylative alkylation of gem-difluoroalkenes via C–F bond activation enabled by organic photoredox catalysis has been developed.

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Moxa floss is a type of biomass used as the main combustion material in moxibustion, a therapy that applies heat from moxa floss combustion to points or body areas for treatment. Safety concerns regarding moxa smoke have been raised in recent years. Since moxa floss is the source material in moxibustion, its thermal behavior and pyrolysis products would be related to the products formed in moxa smoke. This work aims to understand the thermal behavior of moxa floss and investigate the pyrolysis products generated from moxa floss combustion. Six commercial moxa floss samples of 3 storage years and 10 storage years, and of low, medium, and high ratios, were selected. The kinetic data from moxa floss combustion was carried out by a thermogravimetric analyzer. Pyrolysis-gas chromatography and mass spectroscopy using a gas chromatograph and mass spectrometer equipped with a pyroprobe were used to examine the pyrolysis products. Thermogravimetric profiles for all the samples were overall similar and showed a monotonic weight decrease. The range of intensive reaction temperature occurred between 150°C and 450°C, which was characterized by a major weight loss and accompanied by an exothermal degradation of the main components. The average ignition temperature for the samples of 3 and 10 storage years was 218.3°C and 222.6°C, respectively, which was lower than most herbaceous plants. The identified pyrolysis products include monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, ketones, acids, and alkanes. All were of relatively low intensities of below 5% in relative abundance. No volatiles were detected in the samples of 10 storage years. The relatively low values of ignition temperature suggested that moxa floss is more combustible and can be ignited more easily than other herbaceous plants. This may explain why moxa floss has remained as the preferred material used for moxibustion over the years.