The nickel-catalyzed esterification of carboxylic acids with aryl bromides using thioxanthen-9-one as a photosensitizer provided aryl esters with excellent yields.

developing non-precious electrocatalysts with high performance is of primary significance in a fascinating and scalable water splitting technology for hydrogen production. A number of nickel (Ni)-based heterogeneous catalysts have been designed and synthesized to lower the overpotentials for large current densities due to low cost and facile synthesis. Herein, recent progress on Ni-based composites functioning on hydro-gen evolution reaction (HER), oxygen evolution reaction (OER), and overall water splitting is summarized. The synthesis strategies, structure design and performance analysis of Nibased heterostructured catalysts are thoroughly discussed, aiming to promote the development of highly efficient electrocatalysts that may ultimately replace the noble-metal based catalysts and bring water splitting into the practical application.Yuting Li, a Ph.D. student in the Department of Chemical Engineering at Nanjing University of Science and Technology. Her research interests focus on the rational design and synthesis optimization of bifunctional composites and structure control of non-noble-metal heterogeneous nanomaterials for electrocatalyzing water splitting.

Visible-light-driven, intramolecular C­(sp2)–H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.

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STUDY QUESTION What is the relationship between pre-pregnancy maternal glucose levels and fecundability in Chinese couples? SUMMARY ANSWER Elevated pre-pregnancy maternal glucose levels were associated with fecundability, as reflected by prolonged time to pregnancy (TTP) among the couples with no prior gravidity. STUDY DESIGN, SIZE, DURATION Based on the National Free Pre-conception Check-up Projects supported by the Chinese government, 2 226 048 eligible couples attempting first pregnancy and participating in the project from 2015 to 2016 were included. They were followed-up for 1 year or until they reported pregnancy. PARTICIPANTS/MATERIALS, SETTINGS, METHODS The Kaplan–Meier method was used to estimate the cumulative pregnancy rate in each menstrual cycle, and the discrete-time analogue of the Cox models was used to estimate the fecundability odds ratios (FORs) and 95% CIs by different pre-pregnancy maternal glucose levels (impaired fasting glucose (IFG) or diabetes as compared to normal). MAIN RESULTS AND THE ROLE OF CHANCE The cumulative pregnancy rate for 12 cycles of the normal fasting plasma glucose (FPG) level group was 42.29%, significantly higher than that of the IFG (35.52%) and diabetes groups (31.52%). After adjusting for confounding factors, the FORs were 0.82 (95% CI: 0.81–0.83) and 0.74 (95% CI: 0.72–0.76) for the IFG and diabetes groups, respectively, as compared to the normal group. The association between pre-pregnancy maternal FPG levels and the FORs was non-linear, and the optimal FPG level for greatest fecundability (shortest TTP) was 3.90–4.89 mmol/L. LIMITATIONS, REASONS FOR CAUTION The findings from this register-based cohort study require cautious interpretation given that information bias would be inevitable for single FPG measurements and for TTP calculations that were based on telephone follow-up information. Additionally, because couples who achieved pregnancy during their first menstrual cycle in the study were excluded, the pregnancy rates reported were low and possibly biased. WIDER IMPLICATIONS OF THE FINDINGS The current report suggests that elevated pre-pregnancy maternal glucose levels were associated with prolonged TTP. Early evaluation and preventive treatment for female partners with IFG or diabetes in a pre-pregnancy examination are necessary. STUDY FUNDING/COMPETING INTEREST(S) Funding was provided by the National Key Research and Development Program of China (grants No. 2016YFC1000300 and 2016YFC1000307), the National Natural Science Foundation of China (grant No. 81872634), the CAMS Innovation Fund for Medical Sciences (grant No. 2018-I2M-1-004), the National Human Genetic Resources Sharing Service Platform (grant No. 2005DKA21300) and the National Population and Reproductive Health Science Data Center (grant No. 2005DKA32408), People’s Republic of China. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER N/A

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Porphyrin‐based NiFe porous organic polymers (POPs) have been synthesized with good porosity and large BET surface areas (261 to 313 m2 g−1). These bimetallic POPs exhibit RuO2‐like OER activity, with the reaction for catalyst FeTAPP‐NiTCPP‐POP reaching a current density of 10 mA cm−2 at a low overpotential of 338 mV and with a small Tafel slope of 52 mV dec−1. FeTAPP‐NiTCPP‐POP was stable over a long period under reaction conditions. These bimetallic POPs exhibit better catalytic activity than their monometallic counterparts, due to synergetic interactions between the iron and nickel centers to facilitate the electrocatalytic process.

Objective The antenatal screening strategy remains inadequate for eliminating congenital syphilis. To further eliminate maternal fetal transmission, preconception syphilis screening is considered an option. In this study, we investigated syphilis seropositivity and intra-couple discordance among married couples planning a pregnancy in China to provide essential baseline evidence for preconception syphilis screening.Design Population-based survey.Setting National preconception registered data.Population Married Chinese couples planning conception within 6 months between 2013 and 2018.Methods Syphilis was screened using rapid plasma reagin (RPR); infection self-reporting and sociodemographic characteristics were collected through questionnaires and medical records, respectively. R 3.2.2 and ARCGIS 10.2 were used for statistical analyses and geographic mapping.Main outcome measures RPR seropositivity.Results Among 31 955 041 couples, 29 737 172 (93.06%) had complete RPR results for both spouses; of those, 0.62% (186 100) were seropositive, with dramatic intra-couple discordance, with 0.33% positivity in wives, 0.24% positivity in husbands and 0.05% positivity in both spouses. Across time, both seropositivity and intra-couple discordance remained stable. Seropositivity in different regions varied significantly, with provincial rates ranging geographically from Tibet (0.8%) to Hebei (0.2%) (P < 0.05). Economic level was an independent factor for this regional variation, with seropositivity increasing as gross domestic product income decreased (P < 0.05).Conclusions Intra-couple discordance in seropositivity for syphilis is notable among couples, with a considerable rate of pre-existing syphilis before pregnancy. Thus, screening both spouses during integrated preconception health care is recommended for further eliminating maternal-fetal transmission.