Insights on enhancing piezocatalytic performance of Bi2WO6@PDA homojunction from phase coexistence and electron transfer mediators.

Piezocatalytic technology with controllable generation of reactive oxygen species (ROS) is emerging in wastewater treatment. This study employed the synergetic regulation of functional surface and phase interface modification to effectively accelerate redox reaction in piezocatalytic process. We anchored the conductive polydopamine (PDA) onto Bi2WO6 (BWO) using template method, in which a small amount of Bi precipitation to induce partial phase transition of BWO from tetragonal to orthorhombic (t/o) in virtue of simple calcination. ROS traceability studies have identified the synergistic relationship between charge separation and transfer. Polarization in two-phase coexistence is intimately modulated by the orthorhombic relative central cation displacement. The orthorhombic phase with large electric dipole moment significantly promotes the generation of piezoresistive effect of intrinsic tetragonal BWO and optimizes the charge distribution. PDA further overcomes the obstruction of carrier migration at the phases interface to accelerate the generation rate of free radicals. Consequently, the superior rhodamine B (RhB) piezocatalytic degradation rate of 0.10 and 0.32 min-1 were delivered by t/o-BWO and t/o-BWO@PDA, respectively. This work reveals a feasible polarization enhancement strategy for the phase coexistence, and flexibly introduces the in-situ synthesized economical polymer conductive unit into the piezocatalysts.

Magnetically retrievable Fe3O4@SiO2@ZnO piezo-photocatalyst: Synthesis and multiple catalytic properties.

The piezo-/photocatalytic effects of ZnO have been in the limelight because of their great potential in environmental remediation and energy conversion. However, the poor recyclability of the suspended catalysts can cause inevitable secondary pollution, which is one of the major issues that limit the practical application of these materials. To address this problem, a magnetically retrievable Fe3O4@SiO2@ZnO nanocomposite was designed and successfully synthesized by multi-step reactions. The ZnO nanorods were vertically grown on the surface of the magnetic Fe3O4@SiO2 microspheres, while SiO2 served as an insulator to protect the inner core and to inhibit charge transfer across the core/shell interface. The Fe3O4@SiO2@ZnO nanocomposite can be easily collected and separated by using a magnetic field. Along with the good recyclability, the material also exhibited high efficiencies in piezocatalytic, photocatalytic and piezo-photocatalytic dye degradation processes. The rate constant of piezo-photocatalysis reached 95.9 × 10-3 min-1, which was 2.2 and 6.1 times that of the individual piezocatalysis and photocatalysis, respectively. The present result confirmed the existence of a synergetic effect between piezo- and photocatalytic processes. Hereby, we demonstrated that incorporation of a magnetic carrier is a feasible strategy to achieve retrievable and highly efficient piezo-/photocatalyst.

Maintenance of Epstein-Barr virus latency through interaction of LMP2A with CXCR4.

Epstein-Barr virus (EBV) belongs to the subfamily Gammaherpesvirinae and was the first human tumor virus to be discovered. The global rate of EBV infection in adults exceeds 90%. EBV can participate in the regulation of multiple genes and signal pathways through its latency genes. Many studies have shown that CXCR4 is involved in the development of gastric cancer, but there have been few studies on the specific mechanisms involved in EBV-associated gastric cancer (EBVaGC). In this study, we explored the mechanism by which EBV-encoded products maintain latent EBV infection through interaction with CXCR4 and investigated the role of CXCR4 in EBV-positive cells. The results show that there is a positive feedback between the EBV-encoded products and CXCR4, and LMP2A can activate CXCR4 through the NF-κB pathway. In addition, CXCR4 can be fed back to LMP2A and EBNA1 through the ERK signaling pathway. At the same time, CXCR4 can promote the proliferation and migration of EBV-positive cells, reduce the expression of the immediate early protein BZLF1, the late protein EBV gp350, and the viral capsid antigen, and play an important role in maintaining the incubation period of EBV infection. These findings are applicable to the further targeted therapy of EBVaGC.

Bismuth Vacancy-Mediated Quantum Dot Precipitation to Trigger Efficient Piezocatalytic Activity of Bi2WO6 Nanosheets.

Point defects in piezoelectric semiconductors play a significant role in regulating the piezocatalytic performance. However, the role of metal vacancies in piezocatalysis has been less explored than that of oxygen vacancies. Herein, Bi2WO6 (BWO) nanosheets with tunable Bi defects were synthesized using an ion exchange method. High-resolution transmission electron microscopy directly revealed the existence of Bi vacancies in the lattice of BWO nanosheets and the precipitation of Bi quasiparticles. The BWO nanosheets with the highest concentration of Bi vacancies exhibited an excellent decomposition efficiency (7.83 × 10-2 min-1) over rhodamine B under ultrasound. The phenomenon is mainly attributed to the increased charge carrier concentration as a consequence of defect energy levels. In addition, the significant enhancement of light absorption capacity caused by the surface plasmon resonance effect of quasiparticles indicates that Bi ions escape from the lattice and combine with free electrons around BWO to form Bi quantum dots, which function as electron traps to facilitate the separation of charge carriers during the piezocatalytic process. This work systematically reveals the essential affiliation of metal vacancies and surface metal clusters in piezocatalysts and verifies the significance of vacancy engineering in piezocatalytic application.

Synergistic Enhancement of Piezocatalytic Activity of BaTiO3 Convex Polyhedrons Nanocomposited with Ag NPs/Co3O4 QDs Cocatalysts.

Piezocatalysis is one of the green and promising catalytic technologies for the degradation of organic pollutants. Surface modifications such as exposed facet engineering and surface decoration of nanoparticles (NPs) are simple but useful enhancement strategies for a catalytic system. However, the synergistic effect and mechanism of facet engineering and dual-cocatalyst decoration on piezocatalytic activity are still ambiguous and more investigations are expected. Herein, the piezocatalytic activities of BaTiO3 (BTO) polyhedrons with anisotropic {001} and {110} facets and BTO cubes with isotropic {001} facets were compared. Furthermore, BaTiO3 (BTO) convex polyhedrons with selectively deposited Ag NPs and uniformly loaded Co3O4 quantum dots (QDs) are rationally synthesized through photochemical deposition. The individual and synergistic effects of Ag NPs and Co3O4 QDs on the piezocatalytic activities are systematically studied. It was found that dual-cocatalyst-modified BTO possesses the highest piezocatalytic activity in methyl orange degradation, with a reaction constant k of 0.0539 min-1, around 5, 2.2, and 1.3 times higher than that of nonmodified and Ag NP- and Co3O4 QD-modified BTO, respectively. Moreover, dual-cocatalyst-decorated BTO also exhibits excellent piezocatalytic performance in nondye pollutant degradation, with ∼100% tetracycline hydrochloride decomposed in 60 min. By analyzing the contribution, quantifying the amount of different free radicals, and comparing the chemical states of surface elements before and after piezocatalytic measurements, it was inferred that facet-dependent Ag NPs acted as efficient electron-transport sites, while uniformly loaded Co3O4 QDs served as hole-transfer sites to fully facilitate the migration of electrons and holes in a piezocatalytic reaction. This research presents a rational and effectual modification strategy to enhance the piezocatalytic activity of piezocatalysts and gives a thorough discussion of the enhanced mechanism.

Piezoelectric polarization modulated novel Bi2WO6/g-C3N4/ZnO Z-scheme heterojunctions with g-C3N4 intermediate layer for efficient piezo-photocatalytic decomposition of harmful organic pollutants.

It is of great significance to understand the role of carrier in piezocatalysis of composites by studying the separation mode of carriers under dynamic polarization field. Herein, the separation and migration pathways of carriers under piezoelectric field are investigated by synthesizing heterojunctions with Bi2WO6 (BWO) nanosheets grown vertically on g-C3N4 (CN) coated ZnO nanorods and directly on ZnO. Compared with the photocatalysis, the piezocatalytic efficiency of Rhodamine B (RhB) by BWO/ZnO is significantly increased to 0.121 min-1, which indicated the polarization field promotes band tilt and Z-scheme formation. After introducing the CN interlayer, the piezocatalytic efficiency of BWO/CN/ZnO is further improved (0.217 min-1), which can be attributed to the unique core-shell structure with Z-scheme heterojunctions. This unique structure provides more active sites and excited carrier concentration, the intermediate layer CN also reduces the direct contact and recombination of electrons and holes controlled by polarization potential at the interface between BWO and ZnO. This work deeply analyzes the influence of carrier concentration, separation efficiency and transport process on piezocatalysis, which provides a reference for the design of efficient catalysts.

Association between CDK8 gene polymorphisms and dilated cardiomyopathy in a Chinese Han population.

BACKGROUND: Dilated cardiomyopathy (DCM) is one of the most common types of cardiomyopathies. Various genes have been verified to be related to DCM, but the pathogenesis remains unclear. Cyclin-dependent-kinase 8 (CDK8), encoded by the CDK8 gene, is a transcriptional factor that regulates the phosphorylation of RNA polymerase II. It plays an important role in the transcription process and different signaling pathways. This study aimed to investigate the potential role of CDK8 gene polymorphisms in DCM susceptibility and prognosis in a Chinese Han population. METHODS: Two single nucleotide polymorphisms (SNPs) of CDK8, rs17083838 (A/G) and rs7992670 (A/G), were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 341 DCM patients and 381 healthy controls. Survival analysis was performed using Kaplan-Meier curves and Cox regression analysis. RESULTS: The frequencies of allele A of both SNPs rs17083838 and rs7992670 were increased in DCM patients compared to healthy controls (P<0.05). Genotypic frequencies of rs17083838 and rs7992670 were associated with the susceptibility to DCM in the codominant, and recessive models (P<0.05), and AA/AG genotypes of rs17083838 were also related to DCM susceptibility in the dominant model. AA/AG genotypes of rs17083838 and the AA genotype of rs7992670 in the dominant and recessive genetic models presented a correlation with the poor prognosis of DCM patients in both univariate (P<0.05) and multivariate analyses (P<0.05) after adjusting for age, gender, left ventricular end-diastolic diameter (LVEDD), and left ventricular ejection fraction (LVEF). CONCLUSIONS: This research is the first to reveal that CDK8 gene polymorphisms might be related to DCM susceptibility and prognosis in the Chinese Han population.

[Effects of altitude on circulating endothelial progenitor cells and hypoxia-inducible factor-1α in patients with type 2 diabetes].

Objective: To compare the changes in the number of circulating endothelial progenitor cells and hypoxia-inducible factors in patients with type 2 diabetes at different altitudes, and to provide a basis for the research and treatment of type 2 diabetes vascular complications. Methods: Selected Type 2 diabetes patients who were diagnosed in a low altitude area of 386 m (Xianyang City) and a high altitude area of 1 520 m (Lanzhou) (25 persons/29 persons) and healthy persons (20 persons/20 persons) were selected. An automatic biochemical analyzer was used to detect the indexes of blood lipids, blood glucose, and glycosylated hemoglobin of the two groups of people, and the concentration of Hypoxia inducible factor-1α (HIF-1α) was detected by enzyme-linked immunosorbent assay (ELISA). The number of circulating endothelial progenitor cells (EPCs) in peripheral blood was determined by a cytometer. Results: No matter in low or high altitude areas, the number of circulating EPCs in the diabetes group was lower than that in the healthy group (P＜0.01). The levels of body mass index (BMI), waist to hip ratio (WHR), triglyceride (TG), fasting blood glucose (FBG) and glycosylated hemoglobin (HbAlc) were increased (P＜0.05). Compared with the low-altitude group, the expression levels of HIF-1α in diabetic patients at high-altitude and healthy people were increased significantly (P＜0.05), while the number of circulating EPCs was decreased significantly (P＜0.05), and the number of circulating EPCs in healthy people or the patients with type 2 diabetes without vascular complications was higher than that of patients with type 2 diabetes with vascular complications (P＜0.05). Conclusion: With the increase in altitude, the expression level of HIF-1α in type 2 diabetes mellitus(T2DM)patients is increased, and the number of circulating EPCs is decreased, which is closely related to the degree of vascular disease. Therefore, it is possible through transplantation of EPCs for high altitude T2DM patients to achieve the prevention and improvement of diabetic vascular complications.

A new strategy for large-scale synthesis of Na0.5Bi0.5TiO3 nanowires and their application in piezocatalytic degradation.

Developing new techniques that can synthesize one-dimensional piezoelectric materials on a large scale is of great significance for boosting piezocatalytic applications. In this work, we proposed a high-efficiency template hydrothermal method for large-scale synthesis of piezoelectric Na0.5Bi0.5TiO3 (NBT) nanowires. By ion-exchange with Bi3+, Na2Ti3O7 template nanowires can be easily and entirely transformed to NBT. The piezocatalytic activity of the NBT nanowires was thoroughly investigated with respect to their capability to degrade typical organic pollutants, including Rhodamine B, methylene blue, methyl orange, tetracycline hydrochloride, phenol, and bisphenol A. The NBT nanowires exhibited the highest efficiency in piezocatalytic degradation of Rhodamine B, which was completely decomposed within 80 min (rate constant ∼0.0575 min-1). The electron spin resonance spin-trapping technique and active species capture experiments were employed to characterize free radicals. The present work is advantageous for the high yield of NBT nanowires and the excellent piezocatalytic performance. The reported template hydrothermal method can potentially be extended to the synthesis of other perovskite nanowires.

Thyroid function abnormalities in COVID-19 patients

BackgroundThe novel coronavirus COVID-19, has caused a worldwide pandemic, impairing several human organs and systems. Whether COVID-19 affects human thyroid function remains unknown. Methods84 hospitalized COVID-19 patients in the First Affiliated Hospital, Zhejiang University School of Medicine (Hangzhou, China) were respectively enrolled in this study. In addition, 91 other patients with pneumonia and 807 healthy subjects were included as controls. FindingsWe found that the levels of TT3 and TSH were lower in COVID-19 patients than control groups (p<0{middle dot}001). Within the group of COVID-19 patients, 61.9% patients (52/84) presented with thyroid function abnormalities. We found a larger proportion of patients in severe condition exhibited thyroid dysfunction than mild/moderate cases (74{middle dot}6% vs. 23{middle dot}8%, p < 0{middle dot}001). Patients with thyroid dysfunction tended to have increased interval time for negative conversion of viral nucleic acid (14{middle dot}1 {+/-} 9{middle dot}4 vs. 10{middle dot}6 {+/-} 8{middle dot}3 days, p = 0{middle dot}088). To note, thyroid dysfunction was also associated with decreased lymphocytes (p < 0{middle dot}001) and increased CRP (p = 0{middle dot}002). In 7 patients with dynamic changes of thyroid function, we observed the levels of TT3 and TSH gradually increased and reached normal range without thyroid hormone replacement at Day 30 post-admission. The correlation between TT3 and TSH level seemed to be positive rather than negative in the early stage, and gradually turned to be negatively related over time. InterpretationsThyroid function abnormalities are common in COVID-19 patients, especially in severe cases. This might be caused by virus attack and damage to the thyroid-pituitary axis. Therefore, more attention should be paid to thyroid function during treatment of COVID-19, and close follow-up is also needed after discharge. FundingThis study was supported by Zhejiang Provincial Science and technology department key R & D plan emergency project (No. 2020c03123-8).

BaTiO3 Nanosheets and Caps Grown on TiO2 Nanorod Arrays as Thin-Film Catalysts for Piezocatalytic Applications.

Powder-form piezocatalysts suffer from poor recyclability and pose a potential threat of creating serious secondary pollution, which restrict their practical applications. Thin-film piezocatalysts, which not only exhibit good recyclability but also fully contact with solution, are believed to be one of the solutions to address these problems. In this work, the nanostructured BaTiO3 (BTO) thin films were fabricated by a facile hydrothermal method for their potential applications in piezocatalysis. The vertically standing BTO nanosheets grown on the top of TiO2 nanorod arrays exhibited superior piezocatalytic performance as well as piezo-electrochemical property. Given the different strain states between thin-film piezocatalyst and powder-form piezocatalyst, both the impact force of water and isostatic pressure are taken into consideration in finite element method (FEM) simulation. The FEM simulation shows that a stronger piezoelectric filed can be built in BTO nanosheets because of their easier deformation, and thus can lead to a higher piezocatalytic degradation efficiency. Our work presented here is expected to provide a potential route for the nanoengineering of thin-film piezocatalysts and clarify the catalytic mechanism for substrate-fixed piezocatalysts.

Management of corona virus disease-19 (COVID-19): the Zhejiang experience / 浙江大学学报·医学版

The current epidemic situation of corona virus disease-19 (COVID-19) still remained severe. As the National Clinical Research Center for Infectious Diseases, the First Affiliated Hospital of Zhejiang University School of Medicine is the primary medical care center for COVID-19 inZhejiang Province. Based on the present expert consensus carried out by National Health Commission and National Administration of Traditional Chinese Medicine, our team summarized and established an effective treatment strategy centered on "Four-Anti and Two-Balance" for clinical practice. The "Four-Anti and Two-Balance"strategy included antivirus, anti-shock, anti-hyoxemia, anti-secondary infection, and maintaining of water, electrolyte and acid base balance and microecological balance. Meanwhile, integrated multidisciplinarypersonalized treatment was recommended to improve therapeutic effect. The importance of early viralogical detection, dynamic monitoring of inflammatory indexes and chest radiograph was emphasized in clinical decision-making. Sputum was observed with the highest positive rate of RT-PCR results. Viral nucleic acids could be detected in10% patients'blood samples at acute periodand 50% of patients had positive RT-PCR results in their feces. We also isolated alive viral strains from feces, indicating potential infectiousness of feces.Dynamic cytokine detection was necessary to timely identifyingcytokine storms and application of artificial liver blood purification system. The "Four-Anti and Two-Balance"strategyeffectively increased cure rate and reduced mortality. Early antiviral treatment could alleviate disease severity and prevent illness progression, and we found lopinavir/ritonavir combined with abidol showed antiviraleffects in COVID-19. Shock and hypoxemia were usually caused by cytokine storms. The artificial liver blood purification system could rapidly remove inflammatory mediators and block cytokine storm.Moreover, it also favoredthe balance of fluid, electrolyte and acid-base and thus improved treatment efficacy in critical illness. For cases of severe illness, early and also short periods of moderate glucocorticoid was supported. Patients with oxygenation index below 200 mmHg should be transferred to intensive medical center. Conservative oxygen therapy was preferred and noninvasive ventilation was not recommended. Patients with mechanical ventilation should be strictly supervised with cluster ventilator-associated pneumonia prevention strategies. Antimicrobial prophylaxis should be prescribed rationally and was not recommended except for patients with long course of disease, repeated fever and elevated procalcitonin (PCT), meanwhile secondary fungal infection should be concerned.Some patients with COVID-19 showed intestinal microbialdysbiosis with decreasedprobiotics such as and . Nutritional and gastrointestinal function should be assessed for all patients.Nutritional support and application of prebiotics or probiotics were suggested to regulate the balance of intestinal microbiota and reduce the risk of secondary infection due to bacterial translocation. Anxiety and fear were common in patients with COVID-19. Therefore, we established dynamic assessment and warning for psychological crisis. We also integrated Chinese medicine in treatment to promote disease rehabilitation through classification methods of traditional Chinese medicine. We optimized nursing process for severe patients to promote their rehabilitation. It remained unclear about viral clearance pattern after the SARS-CoV-2 infection. Therefore, two weeks' quarantine for discharged patients was required and a regular following up was also needed.The Zhejiang experience above and suggestions have been implemented in our center and achieved good results. However, since COVID-19 was a newly emerging disease, more work was warranted to improve strategies of prevention, diagnosis and treatment for COVID-19.

Management of COVID-19: the Zhejiang experience / 浙江大学学报·医学版

The current epidemic situation of coronavirus disease 2019 (COVID-19) still remained severe. As the National Clinical Research Center for Infectious Diseases, the First Affiliated Hospital of Zhejiang University School of Medicine is the primary medical care center for COVID-19 in Zhejiang province. Based on the present expert consensus carried out by National Health Commission and National Administration of Traditional Chinese Medicine, our team summarized and established an effective treatment strategy centered on "Four-Anti and Two-Balance" for clinical practice. The "Four-Anti and Two-Balance" strategy included antivirus, anti-shock, anti-hyoxemia, anti-secondary infection, and maintaining of water, electrolyte and acid base balance and microecological balance. Meanwhile, integrated multidisciplinary personalized treatment was recommended to improve therapeutic effect. The importance of early viralogical detection, dynamic monitoring of inflammatory indexes and chest radiograph was emphasized in clinical decision-making. Sputum was observed with the highest positive rate of RT-PCR results. Viral nucleic acids could be detected in 10%patients' blood samples at acute period and 50%of patients had positive RT-PCR results in their feces. We also isolated alive viral strains from feces, indicating potential infectiousness of feces.Dynamic cytokine detection was necessary to timely identifying cytokine storms and application of artificial liver blood purification system. The "Four-Anti and Two-Balance" strategy effectively increased cure rate and reduced mortality. Early antiviral treatment could alleviate disease severity and prevent illness progression, and we found lopinavir/ritonavir combined with abidol showed antiviral effects in COVID-19. Shock and hypoxemia were usually caused by cytokine storms. The artificial liver blood purification system could rapidly remove inflammatory mediators and block cytokine storm.Moreover, it also favored the balance of fluid, electrolyte and acid-base and thus improved treatment efficacy in critical illness. For cases of severe illness, early and also short period of moderate glucocorticoid was supported. Patients with oxygenation index below 200 mmHg should be transferred to intensive medical center. Conservative oxygen therapy was preferred and noninvasive ventilation was not recommended. Patients with mechanical ventilation should be strictly supervised with cluster ventilator-associated pneumonia prevention strategies. Antimicrobial prophylaxis was not recommended except for patients with long course of disease, repeated fever and elevated procalcitonin (PCT), meanwhile secondary fungal infection should be concerned.Some patients with COVID-19 showed intestinal microbial dysbiosis with decreased probiotics such as and , so nutritional and gastrointestinal function should be assessed for all patients.Nutritional support and application of prebiotics or probiotics were suggested to regulate the balance of intestinal microbiota and reduce the risk of secondary infection due to bacterial translocation. Anxiety and fear were common in patients with COVID-19. Therefore,we established dynamic assessment and warning for psychological crisis. We also integrated Chinese medicine in treatment to promote disease rehabilitation through classification methods of traditional Chinese medicine. We optimized nursing process for severe patients to promote their rehabilitation. It remained unclear about viral clearance pattern after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Therefore, two weeks' quarantine for discharged patients was required and a regular following up was also needed.The Zhejiang experience and suggestions have been implemented in our center and achieved good results. However, since COVID-19 was a newly emerging disease, more work was warranted to improve strategies of prevention, diagnosis and treatment for COVID-19.

Effect of low-to-moderate dose glucocorticoids on viral clearance in COVID-19: a retrospective study / 中华临床感染病杂志

Objective:To study the effect of low-to-moderate dose glucocorticoid therapy on viral clearance in patients with COVID-19.Methods:A total of 72 patients diagnosed with COVID-19 from January 19 to February 17, 2020 at the First Affiliated Hospital, Zhejiang University School of Medicine were recruited. All patients received oral arbidol and combination of lopinavir/ritonavir or darunavir/cobistitat for antiviral therapy, and symptomatic supportive care. Among them, 51 patients received methylprednisolone (0.75-1.50 mg·kg -1·d -1) (glucocorticoid treatment group), and 21 patients did not use glucocorticoid (control group). The time of virologic negative conversion in sputum and the time of radiologic recovery in lung since onset were compared between the two groups. The Kruskal-Wallis test or Fisher exact test was used to compare the difference between groups. Results:The median ages of the glucocorticoid group and the control group were 52 (45, 62) and 46 (32, 56) years ( χ2=4.365, P<0.05). The clinical conditions at hospital admission were different between the two groups ( P<0.01). The severe cases accounted for 52.0%, while moderate cases in the control group accounted for 71.4%. The median times from the onset to virologic negative conversion in the two groups were 15 (13, 20) and 14 (12, 20) days ( P>0.05). The median times from onset to radiologic recovery were 13 (11, 15) and 13 (12, 17) days in the two groups ( P>0.05). In moderate cases, the median times from the onset to virologic conversion in sputum were 13 (11, 18) days in the glucocorticoid group and 13 (12, 15) days in the control group ( P>0.05). The median times from onset to radiologic recovery in lung were 12 (10, 15) and 13 (12, 17) days, respectively ( P>0.05). Conclusions:Low-to-moderate glucocorticoid treatment has no effect on the time of virus clearance in patients with different clinical types of COVID-19, and also no effect on accelerating radiologic recovery in lung, so it is not recommended.

Retrospective study of low-to-moderate dose glucocorticoids on viral clearance in patients with novel coronavirus pneumonia / 中华临床感染病杂志

Objective@#To study the effect of low-to-moderate dose glucocorticoid therapy on viral clearance time in patients with COVID-19.@*Methods@#A total of 72 patients diagnosed with COVID-19 from January 19 to February 17, 2020 at the First Affiliated Hospital, School of Medicine, Zhejiang University were recruited. All patients received oral abidol and/or combined lopinavir/ritonavir, darunavir antiviral, and symptomatic supportive care. Among them, 51 patients received methylprednisolone (0.75-1.50 mg·kg-1·d-1) (glucocorticoid treatment group), and 21 patients who did not use glucocorticoid were the control group. The time of stable virologic conversion insputumand the time of radiologic recovery in lungsince onset were compared between the two groups and among the normal patients.The Kruskal-Wallis test or Fisher exact test was used to compare the difference between groups.@*Results@#The median ages of the glucocorticoid group and the control group were 52 [interquartile range (IQR):45, 62] years and 46 (IQR: 32, 56)years, and the differences were significant (P<0.05). The clinical conditions at hospital admission were different between the two groups (P<0.01). There were 52.0% critical ill patients in the glucocorticoid treatment group, compared to that of 71.4% normal patients in the control group. The median times from the onset tostable virologic conversion to negative in the two groups were 15 (IQR:13,20) days and 14 (IQR:12,20) days (P>0.05), and the difference was no statistically significant. The median times from onset to radiologic recovery were 13 (IQR: 11,15) days and 13 (IQR:12,17) days in the two groups, and there was no difference (P>0.05). In ordinary patients, the median timesfrom the onset tostable virologic conversion insputum were no difference (P>0.05), with 13 (IQR:11,18) days in the glucocorticoid group and 13 (IQR:12,15) days in the control group; The median times from onset to radiologic recovery in lungwere also no difference (P>0.05), with 12 (IQR: 10,15)days in the glucocorticoid group and 13 (IQR: 12,17) days inthe control group.@*Conclusions@#Low-to-moderate glucocorticoid treatment has no effect on the time of virus clearance in patients with different clinical types of COVID-19. The glucocorticoid is not recommended since no effectiveness on accelerating the improvement of radiologic recovery in lung has been observed.

Synthesis of Bi4Ti3O12 decussated nanoplates with enhanced piezocatalytic activity.

A variety of nanostructured Bi4Ti3O12 materials with diverse morphologies were synthesized by a novel hydrothermal method using layered titanate Na2Ti3O7 as a synthetic precursor. Among these materials, decussated nanoplates exhibit superior piezocatalytic activity compared with other piezocatalysts of the perovskite family. The enhanced piezocatalytic activity is attributed to the large piezoelectric potential difference and the short distance between polar surfaces, which may help enhance the driving force of charge transport. The finite element method (FEM) simulation of piezoelectric response in different Bi4Ti3O12 nanostructures was performed to illustrate the influence of morphological features on the piezocatalytic performance. The catalytic mechanism of Bi4Ti3O12 was investigated by the detection and characterization of free radicals and intermediate products with electron spin resonance (ESR) spin-trapping technique and liquid chromatography-mass spectrometry (LC-MS). This work may push forward the development of piezocatalytic materials, and provide insights into piezocatalysis for environmental applications.

Yulangsan polysaccharide inhibits 4T1 breast cancer cell proliferation and induces apoptosis in vitro and in vivo.

Yulangsan polysaccharide (YLSPS) is derived from the root of Millettia pulchra (Benth.) Kurz var. Recent studies have postulated YLSPS as a regimen for cancer treatment. However, the underlying mechanism anti-breast cancer is still poorly unknown. The aim of this study was to examine the suppressive and apoptosis effect of YLSPS on the growth of breast cancer cell 4T1 and its possible underlying mechanism. In this study, breast cancer cell 4T1 viability and apoptosis were assessed by CCK-8 and flow cytometry, relative quantitative real-time PCR and western blot after treated with drug-serum of YLSPS. Furthermore, therapy experiments were conducted using a Balb/c mouse transplanted tumor model of breast cancer. The number of apoptotic cells and microvascular density (MVD) in the tumor tissues were assessed by TUNEL and CD34 immunostaining. Immunohistochemical assays and ELISA were used to detect the expression of VEGF, Bcl-2, Bax and Caspase-3 in the tissues. The in vitro studies showed that the drug-serum of YLSPS significantly inhibition of proliferation and effectively induced apoptosis of 4T1 cells. Oral administration of YLSPS in the breast cancer models significantly reduced the tumor volume and weight. The enhanced antitumor efficacy was associated with decreased angiogenesis, an enhanced antioxidant capacity, an increased induction of apoptosis and an inhibition of lung metastasis. These findings indicate that YLSPS significantly inhibited mouse breast cancer growth in vitro and in vivo. These data suggest that YLSPS may serve as a potential therapeutic agent for breast cancer.

Annealing atmosphere effect on the resistive switching and magnetic properties of spinel Co3O4 thin films prepared by a sol-gel technique.

Spinel Co3O4 thin films were synthesized using a sol-gel technique to study the annealing atmosphere effect on resistive switching (RS) and magnetic modulation properties. Compared with oxygen and air annealed Pt/Co3O4/Pt stacks, the nitrogen annealed Pt/Co3O4/Pt stack shows optimal switching parameters such as a lower forming voltage, uniform distribution of switching voltages, excellent cycle-to-cycle endurance (>800 cycles), and good data retention. Improvement in switching parameters is ascribed to the formation of confined conducting filaments (CFs) which are composed of oxygen vacancies. From the analysis of current-voltage characteristics and their temperature dependence, the carrier transport mechanism in the high-field region of the high resistance state was dominated by Schottky emission. Besides, temperature dependent resistance and magnetization variations revealed that the physical mechanism of RS can be explained based on the formation and rupture of oxygen vacancy based CFs. In addition, multilevel saturation magnetization under different resistance states is attributed to the variation of oxygen vacancy concentration accompanied with the changes in the valence state of cations. Results suggested that using a nitrogen annealing atmosphere to anneal the thin films is a feasible approach to improve RS parameters and enhance the magnetic properties of Co3O4 thin film, which shows promising applications to design multifunctional electro-magnetic coupling nonvolatile memory devices.

Enhanced Pyroelectric Catalysis of BaTiO3 Nanowires for Utilizing Waste Heat in Pollution Treatment.

A novel catalytic effect of pyroelectric materials induced by a change in temperature, namely pyroelectric catalysis, was found to be attractive due to its ability to utilize waste heat in pollution treatment. In this work, the pyroelectric catalytic properties of BaTiO3 (BTO) nanowires synthesized by a template hydrothermal method have been thoroughly investigated. The nanowires with an elongated polar axis show a superior pyroelectric catalytic performance in comparison with the equiaxial nanoparticles. Our numerical simulation results with a finite element method indicate that the enhanced catalytic efficiency of BTO nanowires can be attributed to the higher pyroelectric potential. On the basis of the pyroelectric effect and our experimental results, a pyroelectric catalytic degradation mechanism has been proposed by taking into account the migration of charge carriers and the formation of reaction radicals. This study for enhancing the pyroelectric catalytic activity by using BTO nanowires may provide a facile, promising, and new reusable strategy for the catalytic degradation of organic dye pollutant by means of temperature variation. It is hoped that the present work gives a clear understanding of the mechanism of pyroelectric catalysis.

Protective Effects of 2-Dodecyl-6-Methoxycyclohexa-2,5 -Diene-1,4-Dione Isolated from Averrhoa Carambola L. (Oxalidaceae) Roots on Neuron Apoptosis and Memory Deficits in Alzheimer's Disease.

BACKGROUND/AIMS: The roots of Averrhoa carambola L. (Oxalidaceae) have long been used as a traditional Chinese medicine for the treatment of headaches, vomiting, coughing and hangovers. 2-dodecyl-6-methoxycyclohexa-2, 5-1, 4-dione (DMDD) has been isolated from A. carambola L. roots, and this study was carried out to investigate the potential beneficial effects of DMDD on neuron apoptosis and memory deficits in Alzheimer's disease. METHODS: The effects of a DMDD on learning and memory in APP/PS1 transgenic AD mice in vivo were investigated via Morris water maze and Y-type electric maze tests. In vitro, Cell viability was assessed by CCK-8. Apoptosis was assessed by Annexin V-FITC/PI flow cytometry assay, and transmission electron microscopy assay. Relative quantitative real-time PCR and Western blot were used to determine the expressions of genes and proteins. RESULTS: The spatial learning and memory deficit, fear memory deficit, as well as apoptosis and loss of neuron in hippocampal area of APP/PS1 mice were reversed by DMDD in APP/PS1 transgenic AD mice. DMDD protected against the Aß1-42-induced apoptosis, loss of mitochondria membrane potential, induction of pro-apoptotic Bcl-2 family protein Bax, reduction of anti-apoptotic Bcl-2 family proteins Bcl-2, and activation of Caspase-3, and -9 in PC-12 cells. The Bcl-2/Bax ratio was also increased in DMDD-pretreated PC-12 cells in vitro and APP/PS1 mice in vivo. CONCLUSION: DMDD has potential benefit on treating learning and memory deficit in APP/PS1 transgenic AD mice, and its effects may be associated with reversing the apoptosis of neuron via inhibiting Bax/Bcl-2 mediated mitochondrial membrane potential loss.