Nosocomial transmission of COVID-19 among immunocompromised hosts can have a serious impact on COVID-19 severity, underlying disease progression and SARS-CoV-2 transmission to other patients and healthcare workers within hospitals. We experienced a nosocomial outbreak of COVID-19 in the setting of a daycare unit for paediatric and young adult cancer patients. Between 9 and 18 November 2020, 473 individuals (181 patients, 247 caregivers/siblings and 45 staff members) were exposed to the index case, who was a nursing staff. Among them, three patients and four caregivers were infected. Two 5-year-old cancer patients with COVID-19 were not severely ill, but a 25-year-old cancer patient showed prolonged shedding of SARS-CoV-2 RNA for at least 12 weeks, which probably infected his mother at home approximately 7–8 weeks after the initial diagnosis. Except for this case, no secondary transmission was observed from the confirmed cases in either the hospital or the community. To conclude, in the day care setting of immunocompromised children and young adults, the rate of in-hospital transmission of SARS-CoV-2 was 1.6% when applying the stringent policy of infection prevention and control, including universal mask application and rapid and extensive contact investigation. Severely immunocompromised children/young adults with COVID-19 would have to be carefully managed after the mandatory isolation period while keeping the possibility of prolonged shedding of live virus in mind.

Licorice (Glycyrrhiza glabra) is an important medicinal herb and has long been used in traditional medicine for the treatment of several diseases worldwide. Understanding the genetic diversity within Glycyrrhiza species is important for the efficient conservation of these medicinal herbs. In this study, we have developed 20 polymorphic chloroplast microsatellite (cpSSR) markers using the chloroplast genome of G. lepidota. The cpSSR markers were tested on a total of 27 Glycyrrhiza individual plants. The number of alleles per locus ranged from two to eight among the Glycyrrhiza accessions. Overall, the Shannon index (I) for each cpSSR ranged from 0.315 to 1.694, the diversity indices (h) were 0.140–0.793 and the unbiased diversity indices (uh) were 0.145–0.825. In addition, the cpSSR markers were successfully divided and classified the 27 Glycyrrhiza individuals into four groups. The cpSSR markers developed in this study could be used in the assessment of genetic diversity and rapid identification of Glycyrrhiza species.

The Korean VLBI Network (KVN) is a unique millimeter VLBI system which is consisted of three 21 m telescopes with relatively short baselines. We present the preliminary results of simultaneous monitoring observations of the 22.2 GHz H2O and 43.1/42.8/86.2/129.3 GHz SiO masers based on the KVN Key Science Project (KSP). We obtained the astrometrically registered maps of the H2O and SiO masers toward nine evolved stars using the source frequency phase referencing method (SFPR). The SFPR maps of the H2O and SiO masers enabled us to investigate the spatial structure and kinematics from the SiO to H2O maser regions including the development of an outward motion from the ring-like or elliptical structures of SiO masers to the asymmetric structures of the 22.2 GHz H2O maser features. In particular, the 86.2/129.3 GHz SiO (v=1, J=2–1 and J=3–2) masers were clearly imaged toward several objects for the first time. The SiO v=1, J=3–2 maser shows different distributions compared to those of the SiO v=1, 2, J=1–0 and v=1, J=2–1 masers implying a different physical condition.

Background: Highly educated participants with normal cognition show lower incidence of Alzheimer's disease (AD) than poorly educated participants, whereas longitudinal studies involving AD have reported that higher education is associated with more rapid cognitive decline. We aimed to evaluate whether highly educated amnestic mild cognitive impairment (aMCI) participants show more rapid cognitive decline than those with lower levels of education.

Methods: A total of 249 aMCI patients enrolled from 31 memory clinics using the standard assessment and diagnostic processes were followed with neuropsychological evaluation (duration 17.2 ± 8.8 months). According to baseline performances on memory tests, participants were divided into early-stage aMCI (−1.5 to −1.0 standard deviation (SD)) and late-stage aMCI (below −1.5 SD) groups. Risk of AD conversion and changes in neuropsychological performances according to the level of education were evaluated.

Results: Sixty-two patients converted to AD over a mean follow-up of 1.43 years. The risk of AD conversion was higher in late-stage aMCI than early-stage aMCI. Cox proportional hazard models showed that aMCI participants, and late-stage aMCI participants in particular, with higher levels of education had a higher risk of AD conversion than those with lower levels of education. Late-stage aMCI participants with higher education showed faster cognitive decline in language, memory, and Clinical Dementia Rating Sum of Boxes (CDR-SOB) scores. On the contrary, early-stage aMCI participants with higher education showed slower cognitive decline in MMSE and CDR-SOB scores.

Conclusions: Our findings suggest that the protective effects of education against cognitive decline remain in early-stage aMCI and disappear in late-stage aMCI.

W Aql is a binary S-type AGB star showing SiO maser emission. The dust distribution around the star is asymmetric, possibly indicating gravitational interaction between the binary pair. There are indications that the gas distribution also exhibits asymmetries. To investigate the source of the circumstellar structures, we applied for and were rewarded VLBI time to map the distribution of the SiO masers around this source and to constrain the presence and distribution of a possible magnetic field. Using VERA observations we also aim at measuring an accurate parallax to determine the binary separation, however, from showing peak emission of 21 Jy in June 2010, the SiO(1-0) v=1 line at 43 GHz has now disappeared. We find no correlation with the stellar pulsational period.

We report trigonometric parallx measurements for H2O masers around the protoplanetary nebula OH 231.8+4.2 carried out with the Very Long Baseline Array. Based on astrometric monitoring for 1 year, we measured a trigonometric parallax of 0.89 ± 0.04 mas, corresponding to a distance of 1.12+0.05−0.05 kpc. This is the most accurate distance to OH 231.8+4.2, and the first one based on an annual parallax measurement. The distribution and internal motions of the H2O masers are consistent with the bipolar outflow suggested in literatures.

The relationship between dietary Zn intake and the risk of atherosclerosis remains unclear, and no epidemiological studies have been reported on the effects of dietary Zn intake on morphological changes in the vascular wall. We examined the relationship between dietary Zn intake and common carotid intima-media thickness (IMT) as a marker of subclinical atherosclerosis among the middle-aged and elderly populations. A cross-sectional analysis of a prospective cohort baseline study was performed with 4564 adults aged 40–89 years and free of clinical CVD. Dietary data were collected by trained interviewers using an FFQ. Common carotid IMT was measured using a B-mode ultrasound imaging technique. Subclinical atherosclerosis was determined using carotid IMT, and defined as >80th percentile of carotid IMT or ≥ 1 mm of carotid IMT. After adjustment for potential confounders, the mean carotid IMT in the low Zn intake group was higher than that in the high Zn intake group. When subclinical atherosclerosis was defined as >80th percentile value of IMT or ≥ 1 mm of carotid IMT, after adjustment for potential confounders, Zn intake was inversely related to subclinical atherosclerosis (5th v. 1st quintile, OR 0·64, 95 % CI 0·45, 0·90, P for trend = 0·069; 5th v. 1st quintile, OR 0·34, 95 % CI 0·16, 0·70, P for trend = 0·005, respectively). In persons free of clinical CVD, dietary Zn intake was inversely correlated with subclinical atherosclerosis. The present findings suggest a putative protective role of dietary Zn intake against the development of atherosclerosis.

The preparation of BaMgAl10O17:Eu2+ (BAM) blue phosphor layer for a plasma display panel by the addition of a newly designed energetic dispersant (hereafter referred to as SAIT7) and its resulting photoluminescence (PL) efficiency is investigated. The addition of SAIT7 increases the maximum solids loading of BAM phosphor paste from 27.91 to 35.87 vol% and yields a highly packed microstructure of the phosphor layer. The PL intensity is increased by 7.57% compared to the BAM blue phosphor layer prepared without SAIT7. In conclusion, the addition of SAIT7 increased the packing density of the phosphor layer and resulted in improved luminescent properties of the phosphor layer.

We present results of astrometric observations of S269 H2O maser performed with VERA (VLBI Exploration of Radio Astrometry). We have monitored the positions of S269 H2O masers for 1 year and successfully detected its parallax to be 189±8 micro-arcsecond. This corresponds to a source distance of 5.28+0.24−0.22 kpc, and is the smallest parallax (and thus the largest distance) that has ever been measured by means of annual parallax. Proper motions of S269 H2O maser were also measured and used to determine the Galactic rotation velocity at the position of S269. Our measurements show that the Galactic rotation velocity at S269 is the same to that at the Sun within 3%, indicating that the Galactic rotation curve is flat out to R~13 kpc.

We have carried out multi-epoch VLBI observations of the H2O maser sources associated with young stellar objects (YSOs) in nearby molecular clouds with VERA (VLBI Exploration of Radio Astrometry), which is a newly constructed VLBI network in Japan (Kobayashi et al. 2003). The main goal of our study is to measure the absolute proper motions and distances to nearby molecular clouds within 1 kpc from the Sun, to reveal their 3-dimensional structures and dynamical properties. Using the VERA dual-beam receiving system (Honma et al. 2003), we have carried out phase-referencing VLBI observations and measured annual parallaxes and absolute proper motions of the H2O maser features with respect to the extragalactic radio sources. We have successfully detected the annual parallax of one of the H2O maser features in Orion KL to be 2.29±0.10 mas, corresponding to the distance of 437±19 pc from the Sun (Hirota et al. 2007). In addition, the annual parallax of SVS13 in NGC 1333 is also determined to be4.10±0.17 mas, corresponding to the distance of 244±10 pc from the Sun, although the life time of the maser features are only 6 months. The absolute proper motions of the H2O maser features associated with Orion KL and NGC 1333 are derived, possibly indicating the outflow motions from the YSOs as well as the systemic motions of the powering sources.

Assessment of nuclear status is important when a biopsied single blastomere is used for embryo sexing. In this study we investigated the nuclear status of blastomeres derived from 8- to 16-cell stage in vitro fertilised bovine embryos to determine the representativeness of a single blastomere for embryo sexing. In 24 embryos analysed, the agreement in sex determination between a biopsied single blastomere and a matched blastocyst by polymerase chain reaction (PCR) was 83.3%. To clarify the discrepancies, karyotypes of blastomeres in 8- to 16-cell stage bovine embryos were analysed. We applied vinblastine sulfate at various concentrations and for different exposure times for metaphase plate induction in 8- to 16-cell stage bovine embryos. The 1.0 mg/ml vinblastine sulfate treatment for 15 h was selected as the most effective condition for induction of a metaphase plate (>45%). Among 22 embryos under these conditions, only 8 of 10 that had a normal diploid chromosome complement showed a sex chromosomal composition of XX or XY (36.4%) and 2 diploid embryos showed mosaicism of the opposite sex of XX and XY in blastomeres of the embryo (9.1%). One haploid embryo contained only one X-chromosome (4.5%). Four of another 11 embryos with a mixoploid chromosomal complement contained a haploid blastomere with a wrong sex chromosome (18.2%). In conclusion, assessment of nuclear status of 8- to 16-cell stage bovine embryos revealed that morphologically normal embryos had a considerable proportion of mixoploid blastomeres and sex chromosomal mosaicism; these could be the cause of discrepancies in the sex between biopsied single blastomeres and matched blastocysts by PCR.