Coronavirus disease 2019 (COVID-19) asymptomatic cases are hard to identify, impeding transmissibility estimation. The value of COVID-19 transmissibility is worth further elucidation for key assumptions in further modelling studies. Through a population-based surveillance network, we collected data on 1342 confirmed cases with a 90-days follow-up for all asymptomatic cases. An age-stratified compartmental model containing contact information was built to estimate the transmissibility of symptomatic and asymptomatic COVID-19 cases. The difference in transmissibility of a symptomatic and asymptomatic case depended on age and was most distinct for the middle-age groups. The asymptomatic cases had a 66.7% lower transmissibility rate than symptomatic cases, and 74.1% (95% CI 65.9–80.7) of all asymptomatic cases were missed in detection. The average proportion of asymptomatic cases was 28.2% (95% CI 23.0–34.6). Simulation demonstrated that the burden of asymptomatic transmission increased as the epidemic continued and could potentially dominate total transmission. The transmissibility of asymptomatic COVID-19 cases is high and asymptomatic COVID-19 cases play a significant role in outbreaks.

We report the crystal structure of allanite-(Ce), with composition (Ca1.0REE0.9□0.1)Σ2.0(Al1.46Fe3+0.52Fe2+0.76Mg0.12Ti0.15)Σ3.01Si3O12(OH) from the Xinfeng rare earth element (REE)-bearing granite in Guangdong Province, China. It has the unit cell a = 8.9550(4) Å, b = 5.77875(16) Å, c = 10.2053(4) Å, β = 114.929(5)° and Z = 2 in space group P21/m and is characterised by site splitting at M3 into M3a and M3b, at a distance of 0.38(3) Å, which are occupied partially by Fe0.764Mg0.12 and Ti0.15, respectively. The structure was determined by single-crystal X-ray diffraction and refined with anisotropic full-matrix least-squares refinement on F2 to R1 = 2.82%, wR2 = 7.77% for 1856 independent reflections (8772 collected reflections). However, M3 splitting is not present in either ferriallanite-(Ce) or epidote, in which M3 is almost fully occupied either by Fe2+ or by Fe3+. Comparisons of bond lengths and volumes in cation polyhedra among allanite-(Ce), ferriallanite-(Ce) and epidote tend to indicate that the essential factor that facilitates site splitting of M3 in allanite-(Ce) is heterovalent substitution and occupation of a crystallographic site between Fe2+(Mg2+/Mn2+)–Al3+(Ti4+), a common phenomenon in minerals, such as the plagioclase series. Fine structure analysis of the M3 split model revealed that deformation of A2 is related closely to distorted M3, which is consistent with Fe2+ incorporation following REE substitution.

Giardia duodenalis is a common zoonotic intestinal pathogen. It has been increasingly reported in humans and animals; however, genotyping information for G. duodenalis in captive animals is still limited. This study was conducted to assess the prevalence and multilocus genotyping of G. duodenalis in captive animals in zoological gardens in Shanghai, China. A total of 678 fresh fecal samples were randomly collected from captive animals including non-human primates (NHPs) (n = 190), herbivores (n = 190), carnivores (n = 151), birds (n = 138) and reptiles (n = 9) in a zoo and were examined for the presence of G. duodenalis using nested polymerase chain reaction (nested PCR). All G. duodenalis positive samples were assayed with PCR followed by sequencing at β-giardin (bg), glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) genes. In this study, 42 specimens (6.2%) were tested G. duodenalis-positive of the 678 fecal samples examined based on a single locus. A total of 30 (4.4%), 30 (4.4%) and 22 (3.2%) specimens were successfully amplified and sequenced at gdh, tpi and bg loci, respectively. Assemblages A and B were identified with assemblage B dominating in NHPs. Sequence analysis demonstrated that one, two and five new isolates were identified at bg, gdh and tpi loci. DNA sequences and new assemblage-subtypes of zoonotic G. duodenalis assemblages A and B were identified in the current study. Our data indicate the occurrence and molecular diversity of G. duodenalis and the potential zoonotic transmission in captive animals in China.

Upper Ordovician strata exposed from the Baiyanhuashan section is the most representative Late Ordovician unit in the northwestern margin of the North China Craton (NCC). In total, 1,215 conodont specimens were obtained from 24 samples through the Wulanhudong and Baiyanhuashan formations at the Baiyanhuashan section. Thirty-six species belonging to 17 genera, including Tasmanognathus coronatus new species, are present. Based on this material, three conodont biozones—the Belodina confluens Biozone, the Yaoxianognathus neimengguensis Biozone, and the Yaoxianognathus yaoxianensis Biozone—have been documented, suggesting that the Baiyanhuashan conodont fauna has a stratigraphic range spanning the early to middle Katian. The Baiyanhuashan conodont fauna includes species both endemic to North China and widespread in tropical zones, allowing a reassessment of the previous correlations of the Katian conodont zonal successions proposed for North China with those established for shallow-water carbonate platforms at low latitudes.

UUID: http://zoobank.org/7cedbd4a-4f7a-4be6-912f-a27fd041b586

Renal fibrosis is common especially in the elderly population. Recently, we found that vitamin D deficiency caused prostatic hyperplasia. This study aimed to investigate whether vitamin D deficiency promotes renal fibrosis and functional impairment. All mice except controls were fed with vitamin D-deficient (VDD) diets, beginning from their early life. The absolute and relative kidney weights on postnatal week 20 were decreased in VDD diet-fed male pups but not in female pups. A mild pathological damage was observed in VDD diet-fed male pups but not in females. Further analysis showed that VDD-induced pathological damage was aggravated, accompanied by renal dysfunction in 40-week-old male pups. An obvious collagen deposition was observed in VDD diet-fed 40-week-old male pups. Moreover, renal α-smooth muscle actin (α-SMA), a marker of epithelial–mesenchymal transition (EMT), and Tgf-β mRNA were up-regulated. The in vitro experiment showed that 1,25-dihydroxyvitamin D3 alleviated transforming growth factor-β1 (TGF-β1)-mediated down-regulation of E-cadherin and inhibited TGF-β1-evoked up-regulation of N-cadherin, vimentin and α-SMA in renal epithelial HK-2 cells. Moreover, 1,25-dihydroxyvitamin D3 suppressed TGF-β1-evoked Smad2/3 phosphorylation in HK-2 cells. These results provide experimental evidence that long-term vitamin D deficiency promotes renal fibrosis and functional impairment, at least partially, through aggravating TGF-β/Smad2/3-mediated EMT in middle-aged male mice.

A novel g-C3N4 nanoparticle@porous g-C3N4 (CNNP@PCN) composite has been successfully fabricated by loading g-C3N4 nanoparticles on the porous g-C3N4 matrix via a simply electrostatic self-assembly method. The composition, morphological structure, optical property, and photocatalytic performance of the composite were evaluated by various measurements, including XRD, SEM, TEM, Zeta potential, DRS, PL, FTIR, and XPS. The results prove that the nanolization of g-C3N4 leads to an apparent blueshift of the absorption edge, and the energy band gap is increased from 2.84 eV of porous g-C3N4 to 3.40 eV of g-C3N4 nanoparticle (Fig. 6). Moreover, the valence band position of the g-C3N4 nanoparticle is about 0.7 eV lower than that of porous g-C3N4. Therefore, the photo-generated holes and electrons in porous g-C3N4 can transfer to the conduction band of g-C3N4 nanoparticle, thereby obtaining higher separation efficiency of photo-generated carriers as well as longer carrier lifetime. Under visible-light irradiation, 6CNNP@PCN exhibits the highest photocatalytic performance (Fig. 8) on MB, which is approximately 3.4 times as that of bulk g-C3N4.

Starch content is an important trait in barley. To evaluate the genetic diversity and identify molecular markers of starch content in barley, 40 cultivated barley genotypes collected from different regions, including genotypes whose starch content is at either the high or low end of the spectrum (15), were used in this study. All the genotypes were re-sequenced by the double-digest-restriction associated DNA sequencing method, and a total of 299,103 single-nucleotide polymorphism (SNP) markers were obtained. The genotypes were divided into four sub-populations based on FASTSTRUCTURE, principal component analysis and neighbour-joining tree analysis. All four sub-populations had a high linkage disequilibrium, especially group 3, whose members were recently bred for malting in the Jiangsu coastal area. The starch content of the barley lines was evaluated during three growing seasons (2014–2017), and the average values of starch content across the three growing seasons at the low and high ends were 51.5 and 55.0%, respectively. The starch content was affected by population structure, the barley in group 2 had a low starch content, while the barley in group 4 had a high starch content. Twenty-six SNP markers were identified as being significantly associated with starch content (P ⩽ 0.001) based on the average values across the three growing seasons using the mixed linear model method. These SNP markers were located on chromosomes 1H and 4H, and were considered loci of qSC1-1 and qSC4-1, respectively. The major identified QTLs for starch content are helpful for further research on carbohydrates and for barley breeding.

This article reports on findings regarding the learning strategies used by a group of Chinese English as a foreign language (EFL) learners in a mobile-technology-assisted environment. The research design is a context-specific case study using Dörnyei’s (2005) categories of learning strategies as the conceptual and analytical framework to guide data collection and analysis. Both quantitative and qualitative data were collected through a questionnaire from a sample of 75 Chinese EFL learners and a small-scale follow-up interview of five participants who completed the questionnaire. Data showed that a mobile-technology-assisted environment effected changes in Chinese EFL learners’ ways of adopting a particular set of learning strategies, which differed in type and frequency from those typical of a teacher-led and examination-oriented language classroom. Metacognitive and commitment control strategies were most frequently used by the respondents in this study. The frequency of student use of metacognitive strategies moved ahead of commitment and environmental control strategies. Satiation and emotion control strategies, rarely used by Chinese students in a teacher-fronted language classroom, were also observable. These findings have implications for the understanding and designing of mobile-technology-assisted learning for EFL learners to develop appropriate strategies for autonomous learning.

Meditation is a type of mental training commonly applied in clinical settings and also practiced for general well-being. Brain functional connectivity (FC) patterns associated with meditation have revealed its brain mechanisms. However, the variety of FC methods applied has made it difficult to identify brain communication patterns associated with meditation. Here we carried out a coordinate-based meta-analysis to get preliminary evidence of meditation effects on changing brain network interactions. Fourteen seed-based, voxel-wise FC studies reported in 13 publications were reviewed; 10 studies with seeds in the default mode network (DMN) were meta-analyzed. Seed coordinates and the effect sizes in statistically significant regions were extracted, based on 170 subjects in meditation groups and 163 subjects in control groups. Seed-based d-mapping was used to analyze meditation versus control FC differences with DMN seeds. Meditation was associated with increased connectivity within DMN and between DMN and somatomotor network and with decreased connectivity between DMN and frontoparietal network (FPN) as well as ventral attention network (VAN). The pattern of decreased within-DMN FC and increased between-network FC (FPN and DAN with DMN) was more robust in highly experienced meditators compared to less experienced individuals. The identified neural network interactions may also promote meditation’s effectiveness in clinical interventions for treating physical and mental disorders.

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a major cause of community-acquired pneumonia in China. Data on epidemiology of paediatric MPP from China are little known. This study retrospectively collected data from June 2006 to June 2016 in Beijing Children's Hospital, Capital Medical University of North China and aims to explore the epidemiological features of paediatric MPP and severe MPP (SMPP) in North China during the past 10 years. A total of 27 498 paediatric patients with pneumonia were enrolled. Among them, 37.5% of paediatric patients had MPP. In this area, an epidemic took place every 2–3 years at the peak, and the positive rate of MPP increased during these peak years over time. The peak age of MPP was between the ages of 6 and 10 years, accounting for 75.2%, significantly more compared with other age groups (χ2 = 1384.1, P < 0.0001). The epidemics peaked in September, October and November (χ2 = 904.9, P < 0.0001). Additionally, 13.0% of MPP paediatric patients were SMPP, but over time, the rate of SMPP increased, reaching 42.6% in 2016. The mean age of paediatric patients with SMPP (6.7 ± 3.0 years old) was younger than that of patients with non-SMPP (7.4 ± 3.2 years old) (t = 3.60, P = 0.0001). The prevalence of MPP and SMPP is common in China, especially in children from 6 to 10 years old. Paediatric patients with SMPP tend to be younger than those with non-SMPP. MPP outbreaks occur every 2–3 years in North China. September, October and November are the peak months, unlike in South China. Understanding the epidemiological characteristics of paediatric MPP can contribute to timely treatment and diagnosis, and may improve the prognosis of children with SMPP.

Underground Nuclear Astrophysics in China (JUNA) will take the advantage of the ultra-low background in Jinping underground lab. High current accelerator with an ECR source and detectors were commissioned. JUNA plans to study directly a number of nuclear reactions important to hydrostatic stellar evolution at their relevant stellar energies. At the first period, JUNA aims at the direct measurements of 25Mg(p,γ)26 Al, 19F(p,α) 16 O, 13C(α, n) 16O and 12C(α,γ) 16O near the Gamow window. The current progress of JUNA will be given.

Combining density functional theory calculations and temperature programmed desorption (TPD) experiments, the adsorption behavior of various sulfur containing compounds, including C2H5SH, CH3SCH3, tetrahydrothiophene, thiophene, benzothiophene, dibenzothiophene, and their derivatives on the coordinately unsaturated sites of Mo27Sx model nanoparticles, are studied systematically. Sulfur molecules with aromaticity prefer flat adsorption than perpendicular adsorption. The adsorption of nonaromatic molecules is stronger than the perpendicular adsorption of aromatic molecules, but weaker than the flat adsorption of them. With gradual hydrogenation (HYD), the binding affinity in the perpendicular adsorption modes increases, while in flat adsorption modes it increases first, then decreases. Significant steric effects on the adsorption of dimethyldibenzothiophene were revealed in perpendicular adsorption modes. The steric effect, besides weakening adsorption, could also activate the S–C bonds through a compensation effect. Finally, by comparing the theoretical adsorption energies with the TPD results, we suggest that HYD and direct-desulfurization path may happen simultaneously, but on different active sites.

In this paper, zircon U–Pb geochronology, major and trace elements, and Sr–Nd isotope geochemistry of the Baiyanghe dolerites in northern West Junggar of NW China are presented. The U–Pb dating of zircons from the dolerites yielded ages of 272.2±4 Ma and 276.7±6.2 Ma, which indicate the emplacement times. The dolerites are characterized by minor variations in SiO2 (46.89 to 49.07 wt%), high contents of Al2O3 (13.60 to 13.92 wt%) and total Fe2O3 (11.14 to 11.70 wt%), and low contents of MgO (2.67 to 3.64 wt%) and total alkalis (Na2O+K2O, 5.1 to 5.97 wt%, K2O/Na2O = 0.37–0.94), which indicate affinities to metaluminous tholeiite basalt. The REE pattern ((La/Sm)N = 2.25–2.34, (La/Yb)N = 7.42–8.36), V–Ti/1000 and 50*Zr–Ti/50–Sm discrimination diagrams show that these rocks are OIB-type. The high contents of Zr and Ti indicate a within-plate tectonic setting, and samples plot in the ‘plume source’ field shown on the Dy/Yb(N) versus Ce/Yb(N) diagram. The positive εNd(t) values (+7.09 to +7.48), high initial 87Sr/86Sr ratios (0.70442 to 0.70682) and depletions of Nb and Ta elements in the samples can be explained by the involvement of subducted sediments. In summary, it is possible that the Baiyanghe dolerites were derived from an OIB-like mantle source and associated with a mantle plume tectonic setting. Therefore, our samples provide the youngest evidence for the existence of a mantle plume, which may provide new insights into the Late Palaeozoic tectonic setting of West Junggar.

Stimulated Brillouin scattering (SBS) effect is currently the major limitation for the power scaling of single-frequency/narrow linewidth fiber laser systems. A single-mode linearly polarized all-fiber amplifier system is set up to investigate SBS effect in triple-frequency high-power amplifiers. With this amplifier, up to 302 W output power with 83% slope efficiency is achieved and the SBS threshold is scaled up to 12 dB. To the best of our knowledge, this is the highest output power of multifrequency laser from a single-mode polarization maintaining fiber. Good spectral properties and high brightness make this laser source available for the application of second harmonic generation, coherent beam combining.

Epidemiological data show that osteoarthritis (OA) is significantly associated with lower birth weight, and that OA may be a type of fetal-originated adult disease. The present study aimed to investigate the prenatal food-restriction (PFR) effect on the quality of articular cartilage in female offspring to explore the underlying mechanisms of fetal-originated OA. Maternal rats were fed a restricted diet from gestational day (GD) 11 to 20 to induce intra-uterine growth retardation. Female fetuses and female adult offspring fed a post-weaning high-fat diet were killed at GD20 and postnatal week 24, respectively. Serum and knee cartilage samples from fetuses and adult female offspring were collected and examined for cholesterol metabolism and histology. Fetal serum corticosterone and insulin-like growth factor-1 (IGF-1) in the PFR group were lower than those of the control, but the serum cholesterol level was not changed. The lower expression of IGF-1 in the PFR group lasted into adulthood. The expression of extracellular matrix (ECM) genes, including type II collagen, aggrecan and cholesterol efflux genes including liver X receptor, were significantly induced, but the ATP-binding-cassette transporter A1 was unchanged. PFR could induce a reduction in ECM synthesis and impaired cholesterol efflux in female offspring, and eventually led to poor quality of articular cartilage and OA.

Environmental filtering and competitive interactions are important ecological processes in community assembly. The contribution of the two processes to community assembly can be evaluated by shifts in functional diversity patterns. We examined the correlations between functional diversity of six traits (leaf chlorophyll concentration, dry matter content, size, specific leaf area, thickness and wood density) and environmental gradients (topography and soil) for 92 species in the 20-ha Dinghushan forest plot in China. A partial Mantel test showed that most of the community-weighted mean trait values changed with terrain convexity and soil fertility, which implied that environmental filtering was occurring. Functional diversity of many traits significantly increased with increasing terrain convexity and soil fertility, which was associated with increased light and below-ground resources respectively. These results suggest that co-occurring species are functionally convergent in regions of strong abiotic stress under the environmental filtering, but functionally divergent in more benign environments due to resource partitioning and competitive interactions. Single-trait diversity and multivariate functional diversity had different relationships with environmental factors, indicating that traits were related to different niche axes, and associated with different ecological processes, which demonstrated the importance of focusing niche axes in traits selection. Between 9% and 41% of variation in functional diversity of different traits was explained by environmental factors in stepwise multiple regression models. Terrain convexity and soil fertility were the best predictors of functional diversity, which contributed 30.5% and 29.0% of total R2 to the model. These provided essential evidence that different environmental factors had distinguishing impacts on regulating diversity of traits.