From 24 January 2020 to 18 May 2020, Chaoshan took measures to limit the spread of coronavirus disease 2019 (COVID-19), such as restricting public gatherings, wearing masks and suspending classes. We explored the effects of these measures on the pathogen spectrum of paediatric respiratory tract infections in Chaoshan. Pharyngeal swab samples were collected from 4075 children hospitalised for respiratory tract infection before (May–December 2019) and after (January–August 2020) the COVID-19 outbreak. We used liquid chip technology to analyse 14 respiratory pathogens. The data were used to explore between-group differences, age-related differences and seasonal variations in respiratory pathogens. The number of cases in the outbreak group (1222) was 42.8% of that in the pre-outbreak group (2853). Virus-detection rates were similar in the outbreak (48.3%, 590/1222) and pre-outbreak groups (51.5%, 1468/2853; χ2 = 3.446, P = 0.065), while the bacteria-detection rate was significantly lower in the outbreak group (26.2%, 320/1222) than in the pre-outbreak group (44.1%, 1258/2853; χ2 = 115.621, P < 0.05). With increasing age, the proportions of respiratory syncytial virus (RSV) and cytomegalovirus (CMV) infections decreased, while those of Mycoplasma pneumoniae and adenovirus infections increased. Streptococcus pneumoniae, CMV and rhinovirus infections peaked in autumn and winter, while RSV infections peaked in summer and winter. We found that the proportion of virus-only detection decreased with age, while the proportion of bacteria-only detection increased with age (Table 2). Anti-COVID-19 measures significantly reduced the number of paediatric hospitalisations for respiratory tract infections, significantly altered the pathogen spectrum of such infections and decreased the overall detection rates of 14 common respiratory pathogens. The proportion of bacterial, but not viral, infections decreased.

In late December 2019, patients of atypical pneumonia due to an unidentified microbial agent were reported in Wuhan, Hubei Province, China. Subsequently, a novel coronavirus was identified as the causative pathogen which was named SARS-CoV-2. As of 12 February 2020, more than 44 000 cases of SARS-CoV-2 infection have been confirmed in China and continue to expand. Provinces, municipalities and autonomous regions of China have launched first-level response to major public health emergencies one after another from 23 January 2020, which means restricting movement of people among provinces, municipalities and autonomous regions. The aim of this study was to explore the correlation between the migration scale index and the number of confirmed coronavirus disease 2019 (COVID-19) cases and to depict the effect of restricting population movement. In this study, Excel 2010 was used to demonstrate the temporal distribution at the day level and SPSS 23.0 was used to analyse the correlation between the migration scale index and the number of confirmed COVID-19 cases. We found that since 23 January 2020, Wuhan migration scale index has dropped significantly and since 26 January 2020, Hubei province migration scale index has dropped significantly. New confirmed COVID-19 cases per day in China except for Wuhan gradually increased since 24 January 2020, and showed a downward trend from 6 February 2020. New confirmed COVID-19 cases per day in China except for Hubei province gradually increased since 24 January 2020, and maintained at a high level from 24 January 2020 to 4 February 2020, then showed a downward trend. Wuhan migration scale index from 9 January to 22 January, 10 January to 23 January and 11 January to 24 January was correlated with the number of new confirmed COVID-19 cases per day in China except for Wuhan from 22 January to 4 February. Hubei province migration scale index from 10 January to 23 January and 11 January to 24 January was correlated with the number of new confirmed COVID-19 cases per day in China except for Hubei province from 22 January to 4 February. Our findings suggested that people who left Wuhan from 9 January to 22 January, and those who left Hubei province from 10 January to 24 January, led to the outbreak in the rest of China. The ‘Wuhan lockdown’ and the launching of the first-level response to this major public health emergency may have had a good effect on controlling the COVID-19 epidemic. Although new COVID-19 cases continued to be confirmed in China outside Wuhan and Hubei provinces, in our opinion, these are second-generation cases.

Previous studies have demonstrated that betaine supplements increase lean body mass in livestock and improve muscle performance in human beings, but evidence for its effect on human lean mass is limited. Our study assessed the association of circulating betaine with lean mass and its composition in Chinese adults. A community-based study was conducted on 1996 Guangzhou residents (weight/mass: 1381/615) aged 50–75 years between 2008 and 2010. An interviewer-administered questionnaire was used to collect general baseline information. Fasting serum betaine was assessed using HPLC-MS. A total of 1590 participants completed the body composition analysis performed using dual-energy X-ray absorptiometry during a mean of 3·2 years of follow-up. After adjustment for age, regression analyses demonstrated a positive association of serum betaine with percentage of lean mass (LM%) of the entire body, trunk and limbs in men (all P<0·05) and LM% of the trunk in women (P=0·016). Each sd increase in serum betaine was associated with increases in LM% of 0·609 (whole body), 0·811 (trunk), 0·422 (limbs), 0·632 (arms) and 0·346 (legs) in men and 0·350 (trunk) in women. Multiple logistic regression analysis revealed that the prevalence of lower LM% decreased by 17 % (whole body) and 14 % (trunk) in women and 23 % (whole body), 28 % (trunk), 22 % (arms) and 26 % (percentage skeletal muscle index) in men with each sd increment in serum betaine. Elevated circulating betaine was associated with a higher LM% and lower prevalence of lower LM% in middle-aged and elderly Chinese adults, particularly men.

Ketoacids (KA) are known to improve muscle mass among patients with chronic kidney disease (CKD) on a low-protein diet (CKD-LPD), but the mechanism of its preventive effects on muscle atrophy still remains unclear. Since muscle atrophy in CKD may be attributable to the down-regulation of the Wnt7a/Akt/p70S6K pathway and the activation of the ubiquitin–proteasome system (UPS) and the apoptotic signalling pathway, a hypothesis can readily be drawn that KA supplementation improves muscle mass by up-regulating the Wnt7a/Akt/p70S6K pathway and counteracting the activation of the UPS and caspase-3-dependent apoptosis in the muscle of CKD-LPD rats. Rats with 5/6 nephrectomy were randomly divided into three groups, and fed with either 22 % protein (normal-protein diet; NPD), 6 % protein (LPD) or 5 % protein plus 1 % KA for 24 weeks. Sham-operated rats with NPD intake were used as the control. The results demonstrated that KA supplementation improved protein synthesis and increased related mediators such as Wnt7a, phosphorylated Akt and p70S6K in the muscle of CKD-LPD rats. It also inhibited protein degradation, withheld the increase in ubiquitin and its ligases MAFbx (muscle atrophy F-box) and MuRF1 (muscle ring finger-1) as well as attenuated proteasome activity in the muscle of CKD-LPD rats. Moreover, KA supplementation gave rise to a reduction in DNA fragment, cleaved caspase-3 and 14 kDa actin fragment via the down-regulation of the Bax:Bcl-2 ratio in the muscle of CKD-LPD rats. The beneficial effects unveiled herein further consolidate that KA may be a better therapeutic strategy for muscle atrophy in CKD-LPD.

A one-dimensional (1D) position sensitive detector (PSD) with the active layer imbedded in resonant cavity is proposed. The lateral photovoltaic effect (LPE) on the surface of active layer is related to the lifetime of photo-generated carriers-electrons and holes pairs. Theoretically, by improving the transmittance of multiple layered systems, the lifetime of carriers can be lengthened. For a photodetector in near infrared, we design the multiple layered system stacked by alternating layers with MgF2 and InP. The calculated result of electric field distribution in the proposed PSD is maximized in active layer with appropriate thickness. By this means, our aim is theoretically accomplished to enhance LPE in PSD based on resonant cavity structure.

A freestanding bulk nanoporous copper with ultralow density has been fabricated through dealloying of as-cast dual-phase Cu1Mn1Al8 alloy, and the dealloying behavior was investigated systematically. The experimental results show that due to different electrochemical activities, the Al11Cu5Mn3 phase of the dual-phase precursor alloy dissolved before AlCu2Mn, which corresponds to the dramatical evolutions of microstructure and composition. Additionally, a formation pattern based upon a mechanism combined “dissolution–redeposition” pattern, “phase-separation” pattern, and “coarsening” process has been built to describe the evolution process, which includes four stages, sequentially defined as “dissolution of Al11Cu5Mn3,” “redeposition of Cu atoms,” “dealloying of AlCu2Mn,” and “coarsening.”

Systematic nanoindentation experiments have been carried out to study the mechanical properties of a nanocrystalline Fe–51Ni coating exhibiting anelastic and creep characteristics. An analytical method based on the correspondence principle for linear viscoelasticity was developed. The holding displacement–time data obtained in indentation creep tests at a high loading rate of 20 mN/s were analyzed, and material parameters related to the elastic, anelastic, and creep characteristics were derived using a model containing one Maxwell unit and two Kelvin units. The anelastic deformation thus contains at least two relaxation processes having relaxation times of 0.37 and 6.8 s, respectively, and the creep deformation is described by a viscosity value of 4.2 × 104 GPa·s for the alloy in an as-deposited state. The anelastic and creep characteristics descend associated with increases of the elastic modulus and hardness values after the alloy was annealed at 673 K.

Variational image segmentation based on the Mumford and Shah model [31], together with implementation by the piecewise constant level-set method (PCLSM) [26], leads to fully nonlinear Total Variation (TV)-Allen-Cahn equations. The commonly-used numerical approaches usually suffer from the difficulties not only with the non-differentiability of the TV-term, but also with directly evolving the discontinuous piecewise constant-structured solutions. In this paper, we propose efficient dual algorithms to overcome these drawbacks. The use of a splitting-penalty method results in TV-Allen-Cahn type models associated with different “double-well” potentials, which allow for the implementation of the dual algorithm of Chambolle [8]. Moreover, we present a new dual algorithm based on an edge-featured penalty of the dual variable, which only requires to solve a vectorial Allen-Cahn type equation with linear ∇(div)-diffusion rather than fully nonlinear diffusion in the Chambolle’s approach. Consequently, more efficient numerical algorithms such as time-splitting method and Fast Fourier Transform (FFT) can be implemented. Various numerical tests show that two dual algorithms are much faster and more stable than the primal gradient descent approach, and the new dual algorithm is at least as efficient as the Chambolle’s algorithm but is more accurate. We demonstrate that the new method also provides a viable alternative for image restoration.

The expression of the YUCAA1 gene and the amount of endogenous indole acetic acid (IAA) in rice (Oryza sativa subsp. japonica) plants and rice suspension cells infected by Rice stripe virus (RSV) were investigated by real-time reverse transcriptase–polymerase chain reaction (RT-PCR) and high-performance liquid chromatography, respectively. The results showed that the expression of the YUCAA1 gene and the amount of endogenous IAA increased at various times (16, 32, 48 and 64 h) after infection of rice suspension cells by RSV. In rice plants infected with RSV, the expression of the YUCAA1 gene and the amount of endogenous IAA increased, in comparison with healthy rice plants, at 4–8 days after infection, and decreased at 12 and 16 days. These results indicated that RSV infection could regulate auxin biosynthesis in rice. Additionally, the expression of the RSV gene CP increased 2.9 times in rice plants after they were treated with a KPSC buffer to deplete the endogenous auxins, and decreased 45% after treatment with 30 μmol/l IAA. All of these results suggest that auxin may play a role in RSV replication in rice plants.

A joule level of XeF(C-A) laser optically pumped by a sectioned surface discharge was developed. The irradiative intensity of pumping source was diagnosed by calculating XeF2 photo-dissociation wave evolvement which was photographed by a framing camera. The photon flux in the wavelength region of 140 to 170nm is about 5 × 1023 photon s−1cm−2, that corresponds to the irradiative brightness temperature of more than 25000 K. The laser experiments were carried out in different conditions. The maximum laser output energy of 2.5 J was obtained with the total conversion efficiency of 0.1%.

Seminiferous tubule tissues from goat fetal testis were treated using four methods. One of the treatments, with 0.1% collagenase for 15 min and then with an enzyme mixture (containing 0.25% trypsin, 10 μg/ml DNase I, 0.04% EDTA) for 5 min showed ideal cell dispersal after centrifugation and washing. The in vitro culture of the cells separated with a different medium system showed that mulberry-shaped male germ-line stem cell (mGSC) clusters and a single layer of Sertoli cells appeared as the original generation in 120 h. The mGSC clusters developed in suspension and were distributed in different locations from the Sertoli cells in the plate. The cells in the marginal area of incompletely digested mGSCs clusters, and the single cells from them, were obviously homogenized after culture for 5 days in a fibre cell feeding layer from fetal mice (MEF feeding layer), whereas identically treated mGSCs clusters co-cultured with Sertoli cells in the same culture system did not displayed clear homogenization in marginal cells of the clusters. Also, the first generation of mGSC clusters co-cultured with Sertoli cells could form the same morphological properties with the original generation; cells in clusters were tight and mGSCs divided more slowly than those in the MEF feeding layer.

Embryonic germ (EG) cells are pluripotent cells derived from the primordial germ cells of gonads, gonadal ridges and mesenteries, and analogies of foetuses, with the ability to undergo both self-renewal and multiple differentiation. These cells can differentiate into derivatives of all three embryonic germ layers when transferred to an in vitro environment and have the ability to form any fully differentiated cell of the body. The present paper investigates some factors influencing the efficiency of isolation and culture of human EG cells, such as foetus age, culture serum, added cytokines and feeder cells. The results demonstrate that foetuses of 7–12 weeks are optimal for in vitro culture of human EG cells. The basic medium consisted of DMEM, 1×non-essential amino acids, 2 mM l-glutamine and 1 mM sodium pyruvate. Supplementation with 15% foetal bovine serum, 4 ng/ml human recombinant leukaemia inhibitory factor, 4 ng/ml basic fibroblast growth factor and 20 ng/ml stem cell factor clearly improved the efficiency of isolation and culture of human EG cells. Murine embryonic fibroblasts were better feeder cells than human embryonic fibroblasts, bovine embryonic fibroblasts or STO cell line.

Rice grassy stunt virus (RGSV), a member of the genus Tenuivirus, is composed of a single nucleocapsid protein and six genomic ssRNA segments. Based on the known RNA sequence of the RGSV-IR isolate, primers were designed and cDNA of the NS3 gene was obtained by reverse transcription of the virus sense (v) RNA3 and PCR amplification, with genomic RNAs of RGSV-SX isolate as template. The cDNA was then cloned and sequenced. The NS3 gene comprised 588 nt and the sequence identities were 99.1%, 96.2% at the nucleotide level and 98.4%, 96.4% at the amino acid level, compared with those of RGSV-IR and -SC isolates. The 22.9 kDa NS3 protein encoded by RGSV-SX vRNA3 showed 33.0% identity to the 21.6 kDa protein encoded by vRNA5 of RGSV over a span of 80 amino acids, and no other significant matches were found in the GenBank database. The NS3 gene was cloned in pGEX-2T to generate a prokaryotic expression plasmid pGTNS3, and a fusion protein of GST-NS3 at 49.0 kDa was induced in Escherichia coli. Antiserum prepared to this protein reacted with NS3 encoded by RGSV in Western blots. The protein was detected only in infected rice (Oryza sativa), not in purified virus or viruliferous planthopper vectors. Thus NS3 appears to be a protein encoded abundantly only while the virus infects the rice host plant and may be related to the virus pathogenesis.