The iridium-catalyzed dehydrogenative cyclization of 2-aminobiphenyls proceeds smoothly in the presence of a copper cocatalyst under air as a terminal oxidant through intramolecular direct C-H amination to produce N-H carbazoles. A similar iridium/copper system can also catalyze the unprecedented dimerization reaction of 2-aminobiphenyl involving 2-fold C-H/N-H couplings.

Mammary glands develop postnatally in response to the hypothalamic-pituitary-gonadal axis. Obesityinduced changes in the local environment, however, retard mammary gland development during late pregnancy and lactation. To clarify the effects of obesity on fundamental duct development, we compared the mammary glands of nulliparous nonpregnant obese mice fed a high-fat diet with those of lean mice fed a normal diet. Obese mice had enlarged mammary glands, reflecting fat pad size, whereas the ducts in obese mice showed a less dense distribution with less frequent branching. Additionally, the ducts were surrounded by thick collagen layers, and were incompletely lined with myoepithelium. Because leptin receptors were localized in the epithelium region and leptin that was highly expressed in the obese glands suppressed mammary epithelial cell proliferation in vitro, the present results suggest that obesity disrupts mammary ductal development, possibly by remodeling the mammary microenvironment and promoting the expression of such paracrine factors as leptin.

The ruthenium-catalyzed alkenylation reactions of 2-aminobiphenyls and cumylamine proceed smoothly to produce the corresponding regioselectively alkenylated products. These reactions involve a C-H bond cleavage directed by their free amino groups.

Objectives To determine the prevalence of burnout according to job category after the first wave of COVID‐19 in Japan and to explore its association with certain factors. Methods An online cross‐sectional survey of health care workers (HCWs) from June 15 to July 6, 2020, was conducted at a tertiary hospital in Tokyo, Japan. Demographic characteristics, results of the Japanese version of the Maslach Burnout Inventory‐General Survey, types of anxiety and stress, changes in life and work after the peak of the pandemic, and types of support aimed at reducing the physical or mental burden, were determined. Results Of 672 HCWs, 149 (22.6%) met the overall burnout criteria. Burnout was more prevalent in women (OR, 3.11; 95% CI, 1.45‐6.67, P = .003), anxiety due to unfamiliarity with personal protective equipment (PPE) (OR, 1.98; 95% CI, 1.20‐3.27, P = .007), and decreased sleep duration (OR, 1.96; 95% CI, 1.20‐3.20, P = .008). Conversely, participants who felt that the delivery of COVID‐19‐related information (OR, .608; 95% CI, .371‐.996, P = .048) and PPE education opportunities (OR, .484; 95% CI, .236‐.993, P = .048) and messages of encouragement at the workplace (OR, .584; 95% CI, .352‐.969; p = .037) was helpful experienced less burnout. Conclusions There is a need to focus on the above factors to maintain the mental health of HCWs. The delivery of COVID‐19‐related information and educational interventions for PPE and messages of encouragement at the workplace may be needed to reduce the mental burden.

The dehydrogenative direct coupling of a,a-disubstituted benzylamines with acrylates takes place efficiently at room temperature under ruthenium catalysis, accompanied by free amino groupdirected ortho-alkenylation and successive cyclization to produce (isoindol-1-yl)acetic acid derivatives. The reactions using styrenes in place of acrylates proceed effectively in the presence of a rhodium catalyst rather than ruthenium.

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During the life cycle of flowering plants, nuclear fusion, or karyogamy, occurs three times: once during female gametogenesis, when the two polar nuclei fuse in the central cell, and twice during double fertilization. In Arabidopsis thaliana , nuclear fusion events during sexual reproduction proceed without the breakdown of the nuclear envelope, indicating that nuclear membrane fusion is essential for the completion of this process. Arabidopsis gamete expressed 1 (GEX1) is a membrane protein that is conserved among plant species. GEX1 shares homology with the yeast karyogamy protein Kar5, which is primarily expressed in the nuclear membrane. The GEX1 family represents a putative karyogamy factor. Herein, we show that GEX1 is required for the nuclear fusion events in Arabidopsis reproduction. GEX1-deficient mature female gametophytes were found to contain two unfused polar nuclei in close proximity within the central cell. Electron microscopy showed that the outer membrane of the polar nuclei was connected via the endoplasmic reticulum, whereas the inner membrane remained unfused. These results indicate that GEX1 is involved in polar nuclear membrane fusion following the fusion of the outer nuclear membrane. Furthermore, sperm nuclear fusion events were defective in the fertilized egg and central cell following plasmogamy in the fertilization of gex1-1 female gametophytes by gex1-1 pollen. An analysis of GEX1 localization in the female gametophyte using a transgenic line expressing GFP-tagged GEX1 driven by the GEX1 promoter showed that GEX1 is a nuclear membrane protein in the egg and central cell. Time-lapse live-cell imaging showed that in developing female gametophytes, the nuclear GFP-GEX1 signal was first detectable in the central cell shortly before the polar nuclei came in close contact, and then in the egg cell. Thus, we suggest that the GEX1-family proteins are nuclear membrane proteins involved in karyogamy in the reproduction of eukaryotes including flowering plants.

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