Consolidation of the perinatal care system and workload of obstetricians: an ecological study in Japan.

Objectives: We examined the relationship between consolidation of delivery and the workload of obstetricians working at perinatal centers. Methods: We conducted a descriptive analysis using perinatal care areas classified into three types (metropolitan, provincial, and rural). We calculated the Herfindahl-Hirschman Index (HHI) as an index of consolidation and the proportion of the deliveries at clinics as an indicator of the low-risk deliveries and the deliveries per center obstetrician as an indicator of obstetricians' workload. We used >150 deliveries yearly as an excess indicator. The correlation between the HHI and obstetricians' workload and the proportion of deliveries at clinics was examined using the Pearson correlation coefficient. Results: The proportion of areas with >150 deliveries yearly was higher in the consolidated areas. In provincial areas, obstetricians' workload was positively correlated with the HHI and was negatively correlated with the proportion of deliveries at clinics. Conclusions: The obstetricians' workload may be increasing where more consolidation occurs. In provincial areas, the center obstetrician's workload could be reduced not only by consolidation but also by sharing the role of handling low-risk deliveries with clinics and hospitals with obstetric units other than perinatal centers.

Shorter Incubation Period among COVID-19 Cases with the BA.1 Omicron Variant.

We aimed to elucidate the range of the incubation period in patients infected with the SARS-CoV-2 Omicron variant in comparison with the Alpha variant. Contact tracing data from three Japanese public health centers (total residents, 1.06 million) collected following the guidelines of the Infectious Diseases Control Law were reviewed for 1589 PCR-confirmed COVID-19 cases diagnosed in January 2022. We identified 77 eligible symptomatic patients for whom the date and setting of transmission were known, in the absence of any other probable routes of transmission. The observed incubation period was 3.03 ± 1.35 days (mean ± SDM). In the log-normal distribution, 5th, 50th and 95th percentile values were 1.3 days (95% CI: 1.0−1.6), 2.8 days (2.5−3.1) and 5.8 days (4.8−7.5), significantly shorter than among the 51 patients with the Alpha variant diagnosed in April and May in 2021 (4.94 days ± 2.19, 2.1 days (1.5−2.7), 4.5 days (4.0−5.1) and 9.6 days (7.4−13.0), p < 0.001). As this incubation period, mainly of sublineage BA.1, is even shorter than that in the Delta variant, it is thought to partially explain the variant replacement occurring in late 2021 to early 2022 in many countries.

Intramolecular cycloaddition of O-tert-butyldimethylsilyloximes in the presence of BF3 x OEt2.

[reaction: see text] Intramolecular cycloaddition of novel 1,3-dipoles, N-boranonitrones, was examined. Treatment of O-tert-butyldimethylsilyloximes 9-12 having olefin moieties with 2 equiv of BF3 x OEt2 generated N-boranonitrones, which underwent intramolecular cycloaddition to afford N-nonsubstituted cycloadducts 16 (and/or 18) after extractive workup. Despite the Lewis-acidic conditions, the olefin geometry of the substrates was retained in the cycloadducts in the present cycloaddition. The electronic nature of the N-boranonitrones appeared to be electrophilic. In the case of substrate 11c, having an electron-donating methyl group at an internal position of the olefin moiety, the cycloaddition gave the bridged cycloadduct 18b. The cycloaddition proceeded at relatively low temperature, and the diastereoselectivity was high.