Our study aimed to systematically analyse the risk factors of coronavirus disease 2019 (COVID-19) patients with severe disease. An electronic search in eight databases to identify studies describing severe or critically ill COVID-19 patients from 1 January 2020 to 3 April 2020. In the end, we meta-analysed 40 studies involving 5872 COVID-19 patients. The average age was higher in severe COVID-19 patients (weighted mean difference; WMD = 10.69, 95%CI 7.83–13.54). Patients with severe disease showed significantly lower platelet count (WMD = −18.63, 95%CI −30.86 to −6.40) and lymphocyte count (WMD = −0.35, 95%CI −0.41 to −0.30) but higher C-reactive protein (CRP; WMD = 42.7, 95%CI 31.12–54.28), lactate dehydrogenase (LDH; WMD = 137.4, 95%CI 105.5–169.3), white blood cell count（WBC), procalcitonin（PCT）, D-dimer, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatinine（Cr）. Similarly, patients who died showed significantly higher WBC, D-dimer, ALT, AST and Cr but similar platelet count and LDH as patients who survived. These results indicate that older age, low platelet count, lymphopenia, elevated levels of LDH, ALT, AST, PCT, Cr and D-dimer are associated with severity of COVID-19 and thus could be used as early identification or even prediction of disease progression.

Thermal conductivity behaviors are one of the most important evaluations of carbon fiber-reinforced carbon matrix (C/C) composites in the field of thermal protective structures. In order to deepen the understanding of the thermal conductivity behaviors of C/C composites, the out-of-plane thermal conductivity of C/C composites is studied by considering voids and the fiber volume fractions. The representative volume element (RVE) models of microscale and mesoscale are proposed. The parameters of the RVE models are captured by X-ray micro-computed tomography. The carbon matrix equivalent models and fiber volume fraction models along the z-direction were established. The effects of the porosity and fiber volume fraction along the z-direction on the thermal conductivity were analyzed. The proposed model was validated by experimental results at room temperature. Further, the numerical methods developed in this study can provide guidance for predicting the thermal conductivity of C/C composites with complex structures.

Ovarian follicle selection is a natural biological process in the pre-ovulatory hierarchy in birds that drives growing follicles to be selected within the ovulatory cycle. Follicle selection in birds is strictly regulated, involving signaling pathways mediated by dietary nutrients, gonadotrophic hormones and paracrine factors. This study aimed to test the hypothesis that dietary Ca may participate in regulating follicle selection in laying ducks through activating the signaling pathway of cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/extracellular signal-regulated kinase (ERK), possibly mediated by gonadotrophic hormones. Female ducks at 22 weeks of age were initially fed one of two Ca-deficient diets (containing 1.8% or 0.38% Ca) or a Ca-adequate control diet (containing 3.6% Ca) for 67 days (depletion period), then all birds were fed the Ca-adequate diet for an additional 67 days (repletion period). Compared with the Ca-adequate control, ducks fed 0.38% Ca during the depletion period had significantly decreased (P < 0.05) numbers of hierarchical follicles and total ovarian weight, which were accompanied by reduced egg production. Plasma concentration of FSH was decreased by the diet containing 1.8% Ca but not by that containing 0.38%. The ovarian content of cAMP was increased with the two Ca-deficient diets, and phosphorylation of PKA and ERK1/2 was increased with 0.38% dietary Ca. Transcripts of ovarian estradiol receptor 2 and luteinizing hormone receptor (LHR) were reduced in the ducks fed the two Ca-deficient diets (P < 0.05), while those of the ovarian follicle stimulating hormone receptor (FSHR) were decreased in the ducks fed 0.38% Ca. The transcript abundance of ovary gap junction proteins, A1 and A4, was reduced with the Ca-deficient diets (P < 0.05). The down-regulation of gene expression of gap junction proteins and hormone receptors, the increased cAMP content and the suppressed hierarchical follicle numbers were reversed by repletion of dietary Ca. These results indicate that dietary Ca deficiency negatively affects follicle selection of laying ducks, independent of FSH, but probably by activating cAMP/PKA/ERK1/2 signaling pathway.

Electrospun membranes have potential applications in the field of waterproof and breathable textile products. However, challenges still exist to improve the breathability, and waterproof and mechanical properties of these microporous membranes. In this paper, a novel hydrophobic microporous nanofiber membrane was prepared via side-by-side electrospinning of fluorosilane-modified silica nanoparticles (F–SiO2) blended with synthesized polyurethane (PU) solution and composited with the polyacrylonitrile (PAN) solution. To prepare F–SiO2, SiO2 nanoparticles were hydrophobically modified by fluorosilane. Composite nanofiber membranes with different blending ratios of PU(F–SiO2)/PAN were fabricated via side-by-side electrospinning by controlling the extruding speed of two spinnerets. Experimental results indicated that regarding F–SiO2 as hydrophobic inorganic particle can improve the hydrophobic properties of PU nanofiber membrane. The prepared PAN/(F–SiO2/PU) nanofiber microporous membranes exhibit relatively excellent waterproof and mechanical properties as that robust tensile strength (19.5 MPa), preferable water vapor permeability [10.3 kg/(m2 d)], favorable water contact angle (137.2°), and superior mechanical properties. It was believed that the reinforced PAN/(F–SiO2/PU) nanofibrous composite membranes have potential applications in chemical protective clothing, army combat uniforms, self-cleaning materials, and other medical products.

This paper investigates the underlying mechanism and boundary condition of the relationship between day-level supervisor developmental feedback (SDF) and day-level in-role performance (IRP) based on the framework of social exchange theory. The current study collects 290 matched surveys nested in 58 Chinese employees for five consecutive days, employing experience sampling method. Using hierarchical linear regression analysis, this paper examines the mediating role of perceived rapport with supervisors (PRS) and the moderating role of job control. Results show SDF has a positive effect on PRS and consequently enhances employee IRP. This indirect effect is moderated by employee job control. When job control is high, SDF helps supervisors develop a high-quality rapport with employees and is conducive to employees improving their IRP. However, when job control is low, the positive effect of SDF on IRP through PRS is not significant.

Severe cracking and unsatisfied mechanical performance are the major challenges of manufacturing titanium aluminide (TiAl) components by selective laser melting (SLM). In this work, graphene oxide (GO) sheets were introduced onto the metal powder surface to improve the manufacturability of SLM of a Ti–48Al–2Cr–2Nb (at.%) alloy and enhance the mechanical strength of the laser-fabricated parts. The effect of laser power and GO content on the macromorphology of single-track processing was investigated, showing that the crack-free track could be obtained with the addition of 0.1–0.5 wt.% GO under a laser power of 110 W. In addition, the characterization of multilayer buildups via electron backscatter diffraction and backscatter electron imaging reveals the grain refinement during SLM of GO/TiAl nanocomposites. Finally, the strength of the as-built samples was examined using micro-hardness test, showing a maximal increase of 21.9% by adding 0.3 wt.% GO into the TiAl powders from laser-fabricated samples without GO.

Early maturity allows weedy rice (Oryza sativa L. f. spontanea) to persist by escaping harvest in paddy fields. A shorter grain-filling period contributes to the early maturity of weedy rice. However, the differences in morphology and endosperm development in the caryopsis between weedy and cultivated rice are largely unexplored. Here, we selected four biotypes of weedy rice and associated cultivated rice (ACR; Oryza sativa) from different latitudes to conduct a common garden experiment. The endosperm development process of the caryopsis was observed by optical microscopy and electron microscopy. Endosperm cell division and starch accumulation rate during grain filling were also measured. The grain development progress in weedy rice was more rapid and earlier than that in ACR. The endosperm development progress of weedy rice was 6 to 8 d earlier than that of ACR. The endosperm cells of weedy rice cellularized earlier and more rapidly than those of ACR, and the starch grains of weedy rice were more sharply polygonal and compactly arranged than those of ACR. The active endosperm cell division period in weedy rice was 4 to 7 d shorter than that in ACR, while the active starch accumulation period of weedy rice was 2 to 8 d shorter than that of ACR. The rapid development of endosperm cells and starch grains leads to the shorter grain-filling period of weedy rice. weedy rice.

A new fast-growing mycobacterium, designated strain QGD101T, was isolated from the sputum of an 84-year-old man suspected of tuberculosis in Wuhan Medical Treatment Center, Hubei, China. This strain was a gram-staining-negative, aerobic, non-spore-forming and catalase-positive bacterium, which was further identified as the NTM by PNB and TCH tests. The moxifloxacin and levofloxacin exhibited strong suppressing function against QGD101T with MIC values of 0.06 and 0.125 µg/ml after drug susceptibility testing of six main antimicrobial agents on mycobacteria. Based on the sequence analysis of 16S rRNA, rpoB, hsp65 and 16S-23S rRNA internal transcribed spacer, the strain QGD101T could not be identified to a species level. Mycobacterium moriokaense ATCC43059T that shared the highest 16S rRNA gene sequence similarity (98%) with strain QGD101T was actually different in genomes average nucleotide identity (78.74%). In addition, the major cellular fatty acids of QGD101T were determined as C18:1ω9c, C16:0 and C18:2ω6c. The DNA G + C content was 64.9% measured by high performance liquid chromatography. Therefore, the phenotypic and genotypic characterisation of this strain led us to the conclusion that it represents a novel species of mycobacteria, for which the name Mycobacterium hubeiense sp. nov. (type strain QGD101T = CCTCCAA 2017003T = KCTC39927T) was proposed. Thus, the results of this study are very significant for the clinical diagnosis of tuberculosis and future personalised medicine.

A detailed electron backscatter diffraction (EBSD) characterization was utilized to investigate abnormal grain growth behavior of nanocrystalline (NC) Au films constrained by a flexible substrate under cyclic loading. Abnormally grown grains (AGGs) in front of about 15 fatigue cracks were picked out to investigate the grain reorientation behavior during abnormal grain growth in the fatigue crack tip in the cyclically deformed thin films. It shows that the AGGs exhibited 〈001〉 orientation along the loading direction, whereas grains grown far away from fatigue cracks had no significant texture change. The cyclic cumulative shear strain was found to play a key role in grain reorientation. A lattice rotation model was proposed to elucidate the grain reorientation mechanism during abnormal grain growth. Such grain reorientation behavior of NC metals was found to provide an intrinsic resistance of the NC metals to fatigue damage.

To reduce the seed length while maintaining the advantages of the cuboid KDP-type crystal, a long-seed KDP crystal with size $471~\text{mm}\times 480~\text{mm}\times 400~\text{mm}$ is rapidly grown. With almost the same high cutting efficiency to obtain third harmonic generation oriented samples, this long-seed KDP-type crystal can be grown with a shorter seed than that of the cuboid KDP-type crystal. The full width at half maximum of the high-resolution X-ray diffraction of the (200) crystalline face is 28.8 arc seconds, indicating that the long-seed KDP crystal has good crystalline quality. In the wavelength range of 377–1022 nm, the transmittance of the long-seed KDP crystal is higher than 90%. The fluence for the 50% probability of laser-induced damage (LID) is $18.5~\text{J}/\text{cm}^{2}$ (3 ns, 355 nm). Several test points survive when the laser fluence exceeds $30~\text{J}/\text{cm}^{2}$ (3 ns, 355 nm), indicating the good LID performance of the long-seed KDP crystal. At present, the growth of a long-seed DKDP crystal is under way.

The synergetic effects of surface smoothing exhibited during the inductively coupled plasma reactive ion etching (ICP-RIE) of free-standing polycrystalline diamonds (PCDs) were investigated. Changing the assistive gas types generated variable surface oxidation states and chemical environments that resulted in different etching rates and surface morphologies. The main reaction bond mechanism (C–O) during ICP-RIE and the ratio of C–O–C/O–C=O associated with the existence of a uniform smooth surface with root mean square (RMS) roughness of 2.36 nm were observed. An optimal process for PCD smoothing at high etching rate (4.6 μm/min) was achieved as follows: 10% gas additions of CHF3 in O2 plasma at radio frequency power of 400 W. The further etched ultra-smooth surface with RMS roughness <0.5 nm at etching rate of 0.23 μm/min that being produced by transferring this optimum recipe on single crystal diamonds with surface patterns confirmed the effectiveness of the fast smoothing approach and its feasibility for diamond surface patterning.

The personalization of products and services has become an inevitable trend in the manufacturing and service industry, but it is very difficult to identify users' personalized requirements accurately. This paper solves this problem by constructing an identifying model for personalized requirement based on user profiling. Firstly, the framework of the proposed model and the process of identifying the user's personalized requirements with this model are introduced, and then an experimental scheme for obtaining users' profiling data is designed. On this basis, an experiment is performed by investigating users' requirements for the computer to obtain the data, and the data are used for the analysis based on the proposed model. The analysis result shows that the model can reveal the difference among heterogeneous users well, find out the implicit requirements of users, and identify the gap between existing products and users' personalized requirements, which provides support to the subsequent improvement of product design.

This study aimed to evaluate the clinical characteristics, risk factors and outcomes of adult patients with candidaemia caused by C. albicans vs. non-albicans Candida spp. (NAC). All adult hospitalised cases of candidaemia (2012–2017) at a tertiary hospital in Shenyang were included in the retrospective study, and a total of 180 episodes were analysed. C. parapsilosis was the most frequently isolated species (38.3%), followed by C. albicans (35.6%), C. glabrata (13.9%), C. tropicalis (10%) and others (2.2%). As initial antifungal therapy, 75.0%, 3.9%, 5.6% and 2.2% of patients received fluconazole, caspofungin, micafungin and voriconazole, respectively. Multivariate analyses revealed that total parenteral nutrition was associated with an increased risk of NAC bloodstream infections (BSI) (OR 2.535, 95% CI (1.066–6.026)) vs. C. albicans BSI. Additionally, the presence of a urinary catheter was associated with an increased risk of C. albicans BSI (OR 2.295 (1.129–4.666)) vs. NAC BSI. Moreover, ICU stay (OR 4.013 (1.476–10.906)), renal failure (OR 3.24 (1.084–9.683)), thrombocytopaenia (OR 7.171 (2.152–23.892)) and C. albicans (OR 3.629 (1.352–9.743)) were independent risk factors for candidaemia-related 30-day mortality, while recent cancer surgery was associated with reduced mortality risk (OR 26.479 (2.550–274.918)). All these factors may provide useful information to select initial empirical antifungal agents.

The integration of oscillating water column (OWC) wave energy converters into a coastal structure (breakwater, jetty, pier, etc.) or, more generally, their installation along the coast is an effective way to increase the accessibility of wave power exploitation. In this paper, a theoretical model is developed based on the linear potential flow theory and eigenfunction matching method to evaluate the hydrodynamic performance of an array of OWCs installed along a vertical straight coast. The chamber of each OWC consists of a hollow vertical circular cylinder, which is half embedded in the wall. The OWC chambers in the theoretical model may have different sizes, i.e. different values of the radius, wall thickness and submergence. At the top of each chamber, a Wells turbine is installed to extract power. The effects of the Wells turbine together with the air compressibility are taken into account as a linear power take-off system. The hydrodynamic and wave power extraction performance of the multiple coast-integrated OWCs is compared with that of a single offshore/coast-integrated OWC and of multiple offshore OWCs. More specifically, we analyse the role of the incident wave direction, chamber size (i.e. radius, wall thickness and submergence), spacing between OWCs and number of OWCs by means of the present theoretical model. It is shown that wave power extraction from the coast-integrated OWCs for a certain range of wave conditions can be significantly enhanced due to both the constructive array effect and the constructive coast effect.