Root exudates improve the nutrient acquisition of plants and affect rhizosphere microbial communities. The plant nutrient status affects the composition of root exudates. The purpose of this study was to examine common bean (Phaseolus vulgaris L.) root exudates under phosphorus (P) deficiency using a metabolite profiling technique. Common bean plants were grown in a culture solution at P concentrations of 0 (P0), 1 (P1) and 8 (P8) mg P L−1 for 1, 10 and 20 days after transplanting (DAT). Root exudates were collected, and their metabolites were determined by capillary electrophoresis time-of-flight mass spectrometry (CE-TOF MS). The shoot P concentration and dry weight of common bean plants grown at P0 were lower than those grown at P8. One hundred and fifty-nine, 203 and 212 metabolites were identified in the root exudates, and 16% (26/159), 13% (26/203) and 9% (20/212) of metabolites showed a P0/P8 ratio higher than 2.0 at 1, 10 and 20 DAT, respectively. The relative peak areas of several metabolites, including organic acids and amino acids, in root exudates were higher at P0 than at P8. These results suggest that more than 10% of primary and secondary metabolites are induced to exude from roots of common bean by P deficiency.
In vitro oogenesis is key to elucidating the mechanism of human female germ‐cell development and its anomalies. Accordingly, pluripotent stem cells have been induced into primordial germ cell‐like cells and into oogonia with epigenetic reprogramming, yet further reconstitutions remain a challenge. Here, we demonstrate ex vivo reconstitution of fetal oocyte development in both humans and cynomolgus monkeys (Macaca fascicularis). With an optimized culture of fetal ovary reaggregates over three months, human and monkey oogonia enter and complete the first meiotic prophase to differentiate into diplotene oocytes that form primordial follicles, the source for oogenesis in adults. The cytological and transcriptomic progressions of fetal oocyte development in vitro closely recapitulate those in vivo. A comparison of single‐cell transcriptomes among humans, monkeys, and mice unravels primate‐specific and conserved programs driving fetal oocyte development, the former including a distinct transcriptomic transformation upon oogonia‐to‐oocyte transition and the latter including two active X chromosomes with little X‐chromosome upregulation. Our study provides a critical step forward for realizing human in vitro oogenesis and uncovers salient characteristics of fetal oocyte development in primates.
In this study, Al2O3-gate-insulated metal-insulator-semiconductor (MIS) heterostructure field-effect transistors (HFETs) were fabricated using an Al0.61Ga0.37In0.02N/Al0.18Ga0.82N two-dimensional-electron-gas heterostructure, and their electrical properties were characterized. It was confirmed that the thermally stable quaternary AlGaInN barrier layer contributed to a good ohmic contact resistance of 10.5 Ω mm. This value seemed to be considerably small as an AlGaN-channel heterostructure. The fabricated MIS-HFETs showed good pinch-off characteristics and exhibited a maximum drain current (IDSmax) of approximately 180 mA/mm at the gate bias of +2 V. A high off-state breakdown voltage of 2.5 kV was obtained for the device with a gate-to-drain length of 20 μm.
Currently in Japan, summaries of the number of bankruptcies due to the spread of COVID-19 can only be obtained from surveys conducted by a few research firms targeting particular companies. In this study, we used Japanese telephone directory data containing detailed information on the location and industrial category of stores/facilities nationwide in an effort to infer the influence of COVID-19 on businesses in Japan. We analyzed the temporal change in the number of stores before and after the COVID-19 outbreak. Among other findings, the analysis revealed that the number of travel agencies and facilities offering karaoke and other forms of entertainment declined significantly after the outbreak in some prefectures, with the largest declines in Ibaraki, Osaka, and Hyogo prefectures, and a relatively small decline in Tochigi prefecture. Among the stores and facilities categorized as restaurants and travel-related services, the decline was particularly significant in urban areas such as Tokyo and Osaka prefectures.
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