The global death toll from coronavirus disease (COVID-19) virus as of May 12, 2020, exceeds 286,000. The risk factors for death were attributed to advanced age and comorbidities but have not been ...accurately defined.
To report the clinical features of 85 fatal cases of COVID-19 in two hospitals in Wuhan.
Medical records were collected of 85 fatal cases of COVID-19 between January 9, 2020, and February 15, 2020. Information recorded included medical history, exposure history, comorbidities, symptoms, signs, laboratory findings, computed tomographic scans, and clinical management.
The median age of the patients was 65.8 years, and 72.9% were male. Common symptoms were fever (78 91.8%), shortness of breath (50 58.8%), fatigue (50 58.8%), and dyspnea (60 70.6%). Hypertension, diabetes, and coronary heart disease were the most common comorbidities. Notably, 81.2% of patients had very low eosinophil counts on admission. Complications included respiratory failure (80 94.1%), shock (69 81.2%), acute respiratory distress syndrome (63 74.1%), and arrhythmia (51 60%), among others. Most patients received antibiotic (77 90.6%), antiviral (78 91.8%), and glucocorticoid (65 76.5%) treatments. A total of 38 (44.7%) and 33 (38.8%) patients received intravenous immunoglobulin and IFN-α2b, respectively.
In this depictive study of 85 fatal cases of COVID-19, most cases were males aged over 50 years with noncommunicable chronic diseases. The majority of the patients died of multiple organ failure. Early onset of shortness of breath may be used as an observational symptom for COVID-19 exacerbations. Eosinophilopenia may indicate a poor prognosis. A combination of antimicrobial drugs did not offer considerable benefit to the outcome of this group of patients.
This paper proposes a distributed coordination control method for multiple bidirectional power converters (BPCs) in a hybrid ac/dc microgrid. The researched hybrid ac/dc microgrid is composed of both ...ac and dc subgrids connected by multiple parallel BPCs, and only the ac subgrid contains storages for the sake of economy. The proposed control method can realize the appropriate power interaction between the two subgrids and make the two subgrids to support each other, so the hybrid microgrid can operate well in both the grid-connected and islanded modes. Concretely, there are three improvements in this proposed control methods. First, a d-q-0 three-axis control strategy instead of the conventional d-q two-axis control strategy is adopted to suppress the circulating current on the ac side generated by the multiple parallel BPCs. And then the square of the dc voltage rather than the dc voltage itself is controlled, which can make the control of the dc voltage linearized and can make the BPCs provide well voltage support for the dc subgrid. Second, the dc droop control is adopted for the dc current sharing. Also, in order to relieve the storages from generating too much reactive power if the ac load reactive power is very large in the ac subgrid, the reactive power droop control is adopted to make the BPCs share some reactive power. Third, taking the capacities and load types of the two subgrids into consideration, a coordinated control strategy based on the dc voltage versus the frequency droop is designed to realize the power interaction between the two subgrids. Furthermore, the stability analysis of the proposed control method is conducted. All the conclusions are verified by the real-time hardware-in-loop tests.
In the hybrid ac-dc microgrid, the ac and dc subgrids are connected by bidirectional power converters (BPCs) that play an important role in the load power sharing and power interaction between the ac ...and dc subgrids. The coordination control and circulating current suppression for the parallel BPC system are very challenging. In this paper, a decentralized coordination control method is proposed for parallel three-phase BPCs, which can suppress the circulating currents, realize proper power interaction, and achieve overall load power sharing in both the grid-connected mode and the islanded mode. The performance of the proposed control methods is verified by the real-time hardware-in-loop tests.
Locust plagues threaten agricultural and environmental safety throughout the world.sup.1,2. Aggregation pheromones have a crucial role in the transition of locusts from a solitary form to the ...devastating gregarious form and the formation of large-scale swarms.sup.3,4. However, none of the candidate compounds reported.sup.5-7 meet all the criteria for a locust aggregation pheromone. Here, using behavioural assays, electrophysiological recording, olfactory receptor characterization and field experiments, we demonstrate that 4-vinylanisole (4VA) (also known as 4-methoxystyrene) is an aggregation pheromone of the migratory locust (Locusta migratoria). Both gregarious and solitary locusts are strongly attracted to 4VA, regardless of age and sex. Although it is emitted specifically by gregarious locusts, 4VA production can be triggered by aggregation of four to five solitary locusts. It elicits responses specifically from basiconic sensilla on locust antennae. We also identified OR35 as a specific olfactory receptor of 4VA. Knockout of OR35 using CRISPR-Cas9 markedly reduced the electrophysiological responses of the antennae and impaired 4VA behavioural attractiveness. Finally, field trapping experiments verified the attractiveness of 4VA to experimental and wild populations. These findings identify a locust aggregation pheromone and provide insights for the development of novel control strategies for locusts.
The development of a facile and fast method to construct anisotropic hydrogels with the ability to induce unidirectional growth of cells remains challenging. In this work, we demonstrated anisotropic ...cellulose hydrogels (ACHs) that are composed of nanoscale aligned nanofibers by dissolving cotton liner pulp in alkali/urea aqueous solution. On the basis of directionally controlling the architecture of cellulose chains with a facial prestretching strategy in chemical gel state and locking the highly ordered nanostructure through the formation of close physical networks via strong self-aggregation forces among neighboring cellulose nanofibers, ACHs, combing with a long-range aligned structure, entirely differential mechanical performances along the parallel and perpendicular directions of the hydrogel orientation and optical birefringence, were constructed. The aggregation of hydrogen bonds in anisotropic and isotropic hydrogels are of significant difference, confirmed by nuclear magnetic resonance technology. Importantly, ACHs with microgroove-like structure promote the adhesion and orientation of cardiomyocytes. Our work demonstrated the bottom-up fabrication of polysaccharide-based hydrogels with anisotropic structure and properties, paving the way to potentially apply them in cardiomyocytes in vitro culture system.
Metarhizium is a group of insect-pathogenic fungi that can produce insecticidal metabolites, such as destruxins. Interestingly, the acridid-specific fungus Metarhizium acridum (MAC) can kill locusts ...faster than the generalist fungus Metarhizium robertsii (MAA) even without destruxin. However, the underlying mechanisms of different pathogenesis between host-generalist and host-specialist fungi remain unknown. This study compared transcriptomes and metabolite profiles to analyze the difference in responsiveness of locusts to MAA and MAC infections. Results confirmed that the detoxification and tryptamine catabolic pathways were significantly enriched in locusts after MAC infection compared with MAA infection and that high levels of tryptamine could kill locusts. Furthermore, tryptamine was found to be capable of activating the aryl hydrocarbon receptor of locusts (LmAhR) to produce damaging effects by inducing reactive oxygen species production and immune suppression. Therefore, reducing LmAhR expression by RNAi or inhibitor (SR1) attenuates the lethal effects of tryptamine on locusts. In addition, MAA, not MAC, possessed the monoamine oxidase (Mao) genes in tryptamine catabolism. Hence, deleting MrMao-1 could increase the virulence of generalist MAA on locusts and other insects. Therefore, our study provides a rather feasible way to design novel mycoinsecticides by deleting a gene instead of introducing any exogenous gene or domain.
Alternative splicing is the process of selecting different combinations of splice sites to produce variably spliced mRNAs. However, the relationships between alternative splicing prevalence and level ...(ASP/L) and variations of intron size and organism complexity (OC) remain vague. Here, we developed a robust protocol to analyze the relationships between ASP/L and variations of intron size and OC. Approximately 8 Tb raw RNA-Seq data from 37 eumetazoan species were divided into three sets of species based on variations in intron size and OC. We found a strong positive correlation between ASP/L and OC, but no correlation between ASP/L and intron size across species. Surprisingly, ASP/L displayed a positive correlation with mean intron size of genes within individual genomes. Moreover, our results revealed that four ASP/L-related pathways contributed to the differences in ASP/L that were associated with OC. In particular, the spliceosome pathway displayed distinct genomic features, such as the highest gene expression level, conservation level, and fraction of disordered regions. Interestingly, lower or no obvious correlations were observed among these genomic features. The positive correlation between ASP/L and OC ubiquitously exists in eukaryotes, and this correlation is not affected by the mean intron size of these species. ASP/L-related splicing factors may play an important role in the evolution of OC.
Explore the influence of fear of COVID-19 on depression, with anxiety as a mediator and perceived social support and stress perception as moderates.
From February to March 2020, 1,196 valid data were ...collected online through questionnaire by cluster sampling method. Fear of COVID-19 Questionnaire, the Patient Health Questionnaire 9-Item Scale (PHQ-9), the Generalized Anxiety Disorder 7-Item Scale (GAD-7), the Perceived Social Support Scale (PSSS) and the10-item Perceived Stress Scale (PSS-10) were used as the survey instrument, and the participants were female undergraduates from a liberal arts college of a Chinese university. Common method bias was assessed using Harman's single-factor test in SPSS and confirmatory factor analysis in AMOS. The levels of participants' anxiety, depression and perceived social support were described using frequency and percentage, Pearson Correlation test was used to measure the correlation between the variables. The PROCESS macro for SPSS (Model 1, Model 4, and Model 21) were applied to examine the mediating effect and moderating effect of the model.
Fear of COVID-19 can positively influence depression, anxiety plays a mediating role between fear of COVID-19 and depression, perceived social support negatively moderates the relationship between fear of COVID-19 and anxiety, and stress perception positively moderates the relationship between anxiety and depression. These five variables can form a moderated mediating effect model.
Fear of COVID-19, anxiety and stress perception are risk factors for depression, perceived social support is a protective factor for depression. Reducing the fear of COVID-19, anxiety and stress perception and enhancing perceived social support are beneficial to reduce the level of depression.
Persistent plant viruses usually depend on insects for their transmission; they cannot be transmitted between plants or through mechanical inoculation. However, the mechanism by which persistent ...viruses become pathogenic in insect vectors remains unknown. In this study, we used Rice stripe virus (RSV), its insect vector Laodelphax striatellus and host plant (Oryza sativa) to explore how persistent viruses acquire pathogenicity from insect vectors. RSV acquired phytopathogenicity in both the alimentary tract and the salivary gland of L. striatellus. We mechanically inoculated RSV into rice O. sativa leaves through midrib microinjection. Insect‐derived RSV induced a typical stripe symptom, whereas plant‐derived RSV only produced chlorosis in rice leaves. Insect‐derived RSV had higher expression of genes rdrp, ns2, nsvc2, sp and nsvc4 than plant‐derived RSV, and the latter had higher expression of genes cp and ns3 than the former in rice leaves. Different from plant‐derived RSV, insect‐derived RSV damaged grana stacks within the chloroplast and inhibited photosynthesis by suppressing the photosystem II subunit psbp. This study not only presented a convenient method to mechanically inoculate RSV into plants, but also provided insights into the different pathogenic mechanisms of RSV from the insect vector and from viruliferous plants.
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