非共价改性石墨烯的制备及环氧树脂复合材料导热性能

采用非共价键表面修饰制备了聚乙烯吡咯烷酮(PVP)改性的石墨烯(GR@PVP),通过共混方式将其作为填料与环氧树脂(EP)复合得到了不同填充量的EP/GR复合材料。红外光谱和热重分析结果表明,聚乙烯吡咯烷酮成功接枝到石墨烯表面。动态力学热分析和热性能测试结果表明,EP/GR@PVP复合材料的储能模量、玻璃化转变温度和损耗因子峰高度均比EP/GR复合材料有所降低,表明聚乙烯吡咯烷酮增强了环氧树脂复合材料的柔韧性。采用扫描电子显微镜观察复合材料断面形貌,GR@PVP在环氧树脂中分散均匀,且与基体相容性好。当填料质量分数为2.0%时,EP/GR@PVP复合材料的热导率比纯EP和EP/GR复合材料分别提高了205.3%和52.6%,25℃EP复合材料的表观黏度为13.29 Pa·s,符合电子封装材料对复合材料加工黏度的需求(<20 Pa·s)。其研究为进一步制备高导热、低黏度的电子封装材料提供了一种简便的方法。

C23 ameliorates carbon tetrachloride-induced liver fibrosis in mice

BACKGROUND C23,an oligo-peptide derived from cold-inducible RNA-binding protein(CIRP),has been reported to inhibit tissue inflammation,apoptosis and fibrosis by binding to the CIRP receptor;however,there are few reports on its role in liver fibrosis and the underlying mechanism is unknown.AIM To explore whether C23 plays a significant role in carbon tetrachloride(CCl4)-induced liver fibrosis.METHODS CCl4 was injected for 6 weeks to induce liver fibrosis and C23 was used beginning in the second week.Masson and Sirius red staining were used to examine changes in fiber levels.Inflammatory factors in the liver were detected and changes inα-smooth muscle actin(α-SMA)and collagen I expression were detected via immu-nohistochemical staining to evaluate the activation of hematopoietic stellate cells(HSCs).Western blotting was used to detect the activation status of the trans-forming growth factor-beta(TGF-β)/Smad3 axis after C23 treatment.RESULTS CCl4 successfully induced liver fibrosis in mice,while tumor necrosis factor-alpha(TNF-α),IL(interleukin)-1β,and IL-6 levels increased significantly and the IL-10 level decreased significantly.Interestingly,C23 inhibited this process.On the other hand,C23 significantly inhibited the activation of HSCs induced by CCl4,which inhibited the expression ofα-SMA and the synthesis of collagen I.In terms of mechanism,C23 can block Smad3 phosphorylation significantly and inhibits INTRODUCTION At present there is no specific and effective drug for treating liver fibrosis caused by acute or chronic injury.Although preclinical research has made breakthroughs,their suitability as clinical treatments is still unknown.The activation of hepatic stellate cells(HSCs)caused by chronic inflammation is a key process in the development of liver fibrosis and activated HSCs expressα-smooth muscle actin(α-SMA)and transdifferentiate into myofibroblasts with proliferation,migration and secretion abilities,synthesizing the extracellular matrix to deposit in the hepatocyte space and subse-quently forming liver fibrosis[1].Although therapeutic strategies have improved due to past few efforts there is no ideal treatment for hepatic fibrosis[2].Extracellular cold inducible RNA binding protein(CIRP)has been shown to play a role in various acute and chronic inflammatory diseases by promoting tissue inflammation and apoptosis and inducing fibrosis through its receptor Toll-like receptor 4(TLR4)[3].C23 is a recognized competitive inhibitor of CIRP that can competitively bind to CIRP receptors and reduce tissue damage in inflammatory diseases[4].C23 has been shown to significantly reduce serum tumor necrosis factor-alpha(TNF-α),IL(interleukin)-6 and IL-1βlevels.In addition,it can reduce tissue TLR4,TNF-α,IL-6 and IL-1βlevels and inhibit the colocalization of CIRP and TLR4,which plays a significant role in systemic inflammation[5].Re-search has shown that CIRP induces the inflammatory phenotype of lung fibroblasts in a TLR4-dependent manner[6].On the other hand,CIRP is associated with markers of fibrosis andα-SMA is significantly positively correlated with CIRP.Cirp-/-mice exhibit attenuated expression ofα-SMA and collagen(COL1A1 and COL3A1),decreased hydroxyproline content,decreased histological fibrosis scores,and improved pulmonary hypertension[7].C23 inhibited the release of TNF-α,the degradation of IκB and the nuclear translocation of NF-κB in CIRP-stimulated macrophages in a dose-dependent manner and C23 treatment significantly increased the serum levels of lactic dehydrogenase,alanine ami-notransferase,IL-6,TNF-αand IL-1βin septic CLP mice[8].Based on previous research we hypothesized that C23 might alleviate liver fibrosis by inhibiting acute and chronic inflammation.As a selective hepatotoxic chemical carbon tetrachloride(CCl4).can induce inflammation and activate HSCs,promoting liver fibrosis.This study reveals the role and mechanism of C23 in CCl4-induced liver fibrosis in mice.at room temperature for 30 minutes.The gray value of each group was calculated after chemiluminescence.

Ethnobotany and diversity of medicinal plants used by the Buyi in eastern Yunnan, China

The Buyi are a socio-linguistic group in Yunnan Province of southwest China that have a long history of using medicinal plants as part of their indigenous medical system.Given the limited written documentation of the Buyi indigenous medical system,the objective of this paper is to document the medicinal plants of the Buyi and associated traditional knowledge and transmission.Field research was conducted in four villages in Lubuge Township of Luoping County in Yunnan Province using ethnobotanical methodologies including participatory observation,semi-structured interviews,key informant interviews,and focus group discussions to elicit information on medicinal plants.In total,120 informants(including 15 key informants who are healers)were interviewed.This study found that a total of 121 medicinal plant species belonging to 64 families are used by the Buyi including by local healers to treat different diseases.Among the medicinal plants recorded in this study,56 species(46%)have not previously been documented in the scientific literature as having medicinal value,highlighting the pressing need for ethnobotanical documentation in indigenous communities.The most frequently used medicinal part was the leaf(24.9%of documented plants),and the most common preparation method was decoction(62.8%of medicinal).Medicinal plants were mainly used to treat rheumatism(12.4%of plants),trauma and injuries(9.6%).The documented plants are also used for other non-medicinal purposes including food,fodder,fencing,and ornamental.In addition,35 of the medicinal plants are considered poisonous and are used by local Buyi healers for medicine.The traditional Buyi beliefs and practices associated with the documented medicinal plants likely contributes to their conservation in the environments and around Buyi communities.This study further highlights that ethnomedicinal knowledge of the Buyi is at risk of disappearing due to increased introduction and use of modern medicine in Buyi communities,livelihood changes,rapid modernization,and urbanization.Research,policy,and community programs are urgently needed to conserve the biocultural diversity associated with the Buyi medical system including ethnobotanical knowledge towards supporting both environmental and human wellbeing.

A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus(2019-nCoV) infected pneumonia(standard version)

In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world’s attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development;we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control(including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.

Capacity analysis of transmit beamforming with variable feedback delay

The feedback delay can severely affect the quality of the channel state information at the transmitter （CSIT） which is fed back from the receiver. The outdated CSIT will cause large performance loss in the transmit beamforming systems. The effect of variable feedback delay on the capacity of transmit beamforming systems over Rayleigh fading channels is studied. First, the case of fixed feedback delay is considered and a closed-form expression of system capacity is derived. Based on the results of fixed delay, the delay following certain distributions in variable delay case is assumed and the closed-form expressions of capacities are derived. The closed-form expressions show that the capacity is significantly affected by the statistical characteristics of the feedback delay. The obtained results provide an analytical insight into the effects caused by variable delay on the system capacity.

Role of Darunavir/Cobicisitat for treating COVID-19:initial virological and clinical findings

Background:COVID-19 remains a common threat to public health.In this study,we evaluated the antiviral effects and safety of Darunavir/Cobicisitat(DRV/c)in patients with confirmed COVID-19.Patients and Methods:We studied 66 patients with COVID-19 infection who were admitted to Zhongnan Hospital of Wuhan University between February 3 and March 11,2020.The patients were divided into the DRV/c and the control groups.The primary endpoint was the time of SARS-CoV-2 nucleic acid conversion detected in respiratory specimens.Results:Subjects with confirmed SARS-CoV-2 infection(n=66)were enrolled in this study;32 subjects were enrolled in the DRV/c group and 34 in the control group.The mean time to nucleic acid conversion(NAC)was shorter in the DRV/c group.The cumulative nucleic acid conversion rate(CNACR)in the DRV/c group was higher during the first two weeks,but the difference was not statistically significant.The proportion of fever during hospitalization in the DRV/c group was significantly lower than in the control group(P-value=0.01).It was found that,in the DRV/c group,the NAC of patients with a duration from symptom onset to admission within three days was significantly shorter(7.9±6.7 days)than in patients with a duration from symptom onset to admission above three days(15.9±7.1 days)(P=0.01).Conclusion:Although the combination of DRV/c and routine treatment for patients with non-severe COVID-19 can significantly reduce the proportion of fever after admission,no significant differences were observed between the DRV/c group and the conventional therapy group,including the overall time to NAC,safety,and tolerability.

Online interactive identification method based on ESO disturbance estimation for motion model of double propeller propulsion unmanned surface vehicle

In this paper, the online parameter identification problem of the mathematical model of an unmanned surface vehicle (USV) considering the characteristics of the actuator is studied. A data-driven mathematical model of motion is very meaningful to realize trajectory prediction and adaptive motion control of the USV. An interactive identification algorithm (ESO–MILS, extended state observer–multi-innovation least squares) based on ESO is proposed. The robustness of online identification is improved by expanding the state observer to estimate the current disturbance without making artificial assumptions. Specifically, the three-degree-of-freedom dynamic equation of the double propeller propulsion USV is constructed. A linear model for online identification is derived by parameterization. Based on the least square criterion function, it is proved that the interactive identification method with disturbance estimation can improve the identification accuracy from the perspective of mathematical expectation. The extended state observer is designed to estimate the unknown disturbance in the model. The online interactive update improves the disturbance immunity of the identification algorithm. Finally, the effectiveness of the interactive identification algorithm is verified by simulation experiment and real ship experiment.

大尺寸高端显示器件用薄膜晶体管Al–Mo复合电极坡度的形成过程与可控调节

栅极坡度角(PA)对薄膜晶体管(TFT)性能和良率具有重要影响,如何将坡度角调节到合适的范围是TFT量产中关键技术之一.本文以大尺寸高端显示器件用a-Si TFT的Al/Mo、Mo/Al/Mo电极在磷酸系溶液下刻蚀得到的坡度角为研究对象,探究了膜层结构、Mo厚度、刻蚀时间对坡度角的影响.结果表明:在Al/Mo结构中,随着顶Mo厚度增加,Al与光刻胶之间的间隙增加,刻蚀液更易侵入,侧向刻蚀增强,坡度角减小;在Mo/Al/Mo三层电极结构中,随着底Mo厚度增加,底Mo和中间临近的Al侧壁发生电偶腐蚀,Al侧壁上形成氧化物钝化层,Al刻蚀速率减慢,坡度角变小.水池效应将导致刻蚀液残留在电极底部,阻碍新鲜刻蚀液与底部接触,底部刻蚀速率低于顶部;故当刻蚀时间延长时,底部和顶部刻蚀速率差进一步增大,导致坡度角减小.得到了Mo/Al/Mo坡度角与顶Mo和底Mo厚度回归方程,为调节坡度角和优选Mo厚度提供了依据.此电极坡度角的调节技术可为确保TFT的良率和性能提供参考.

Function and Cryo-EM structures of broadly potent bispecific antibodies against multiple SARS-CoV-2 Omicron sublineages

Dear Editor,SARS-CoV-2 rapidly evolves during the pandemic1 with many variants of concern(VoCs)lineages(Supplementary Fig.S1a).Omicron(B.1.1.529)and its sub-lineages led to multiple infection waves globally.2 Omicron subvariants harbored a high number of mutations,especially in the spike(S)glycoprotein,and clustered in the receptor-binding domain(RBD)(Supplementary Fig.S1b,c;Supplemental Discussion).These subvariants drastically decrease the efficacy of current vaccinations and monoclonal antibody therapies.

新型冠状病毒(2019-nCoV)感染的肺炎诊疗快速建议指南(完整版)

2019新型冠状病毒(2019 novel coronavirus,2019-nCoV)感染的肺炎,因2019年12月发生在武汉的不明原因病毒性肺炎病例而被发现,并于2020年1月12日被世界卫生组织(World Health Organization,WHO)命名。在之后的一个月时间内,2019-nCoV在湖北省内外甚至其他国家传播造成了数以千计的病例出现,同时也引起了民众一定程度的恐慌。本指南的制订希望能够从疾病流行病学、病因学、诊断、治疗、护理、医院感染控制等方面给临床医生、社区居民等提供医疗护理及居家照护相关指导。

CRISPR-Cas9基因编辑技术在乙型肝炎病毒治疗中的应用

乙型肝炎病毒(hepatitis B virus,HBV)能引起患者慢性感染,增加肝硬化和肝癌的风险,是威胁全球健康的一个重要问题.核苷(酸)类似物(NUCs)和干扰素(IFN)是目前治疗HBV仅有的两类药物,然而这两类药物均无法清除稳定存在于细胞核中且能够作为模板产生子代病毒的闭合共价环状DNA(covalently closed circle DNA,cccDNA).此外,HBV耐药相关突变(RAM)和疫苗逃逸突变(VEM)降低了现有治疗和预防策略的成功率.因此,人们在努力开发直接靶向cccDNA,将之失活或清除以实现治愈慢性乙肝的治疗手段.特异性靶向HBV基因组保守区域的CRISPR-Cas9基因编辑系统,不仅能够有效抑制病毒复制,相比其他基因编辑工具,设计也更加简单灵活,成为了一个十分具有吸引力的治疗选择.本文将总结现有CRISPR-Cas9系统在抗乙型肝炎病毒中的研究,并探讨其可能面临的问题与潜在的解决方案.

Baseline Characteristics and Treatment Patterns of the Patients Recruited to the China Registry of Hepatitis B

Background and Aims: Chronic hepatitis B virus(HBV)in-fection remains a major public health problem globally.Here,we describe the baseline characteristics and treatment pro-files of HBV-infected patients recruited to the China Registry of Hepatitis B.Methods: Inclusion criteria were patients with different stages of chronic HBV infection and complete key data.Exclusion criteria were patients with hepatocellular car-cinoma.The baseline clinical,laboratory and treatment pro-files were analyzed.Results: Finally,40,431 patients were included.The median age was 43 years,with 65.2%being men and 51.3%being positive for hepatitis B e antigen(HBeAg).The most common initial diagnosis was chronic hep-atitis B(81.0%),followed by cirrhosis(9.3%),inactive carrier of hepatitis B surface antigen(HBsAg)(6.7%),and immune tolerant phase of hepatitis B infection(3.0%).Among the 21,228 patients who were on treatment,88.0%,10.0%and 2.0%received nucleos(t)ide analogues(NAs),interferon or combination of NAs and interferon,respectively.The propor-tion of patients who received preferred NAs(entecavir or te-nofovir disoproxil fumarate)had increased from 13.5%in 2003 to 79.7%in 2016.Conclusions: We concluded that middle-aged men accounted for most of the patients with chronic hepatitis B in this cross-sectional study.About half of the patients were HBeAg-positive.NAs were the most com-monly used therapy,and use of the preferred NAs had steadily increased in the past decade.

Clinical Characteristics of Hospitalized Patients with SARS-CoV-2 and Hepatitis B Virus Co-infection

Dear Editor,Coronavirus disease 2019(COVID-19)is a global pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-Co V-2).SARS-Co V-2 infection was first detected in Wuhan,China in late December 2019.The virus was spreading rapidly to other cities of China and accumulating cases had been reported(Li et al.2020).

China’s local governments are combating COVID-19 with unprecedented responses——from a Wenzhou governance perspective

The COVID-19 caused by a novel strain of coronavirus has been spreading rapidly since its occurrence in December 2019.It is highly communicable through human-to-human transmission.China has been making unprecedented efforts in treating the confirmed cases,identifying and isolating their close contacts and suspected cases to control the source of infection and cut the route of transmission.China’s devotion in handling this epidemic has effectively and efficiently curbed communication domestically and across the border.Representative measures adopted by Wenzhou,the worst hit city out of Hubei Province,are examined to elucidate those massive undertakings with the aim of enhancing international understanding and building global rapport in fighting this evolving epidemic situation.

A local-optimization refinement algorithm in single particle analysis for macromolecular complex with multiple rigid modules

Single particle analysis, which can be regarded as an average of signals from thousands or even millions of particle projections, is an efficient method to study the three-dimensional structures of biological macro- molecules. An intrinsic assumption in single particle analysis is that all the analyzed particles must have identical composition and conformation. Thus specimen heterogeneity in either composition or conformation has raised great challenges for high-resolution analysis. For particles with multiple conformations, inaccurate align- ments and orientation parameters will yield an averaged map with diminished resolution and smeared density. Besides extensive classification approaches, here based on the assumption that the macromolecular complex is made up of multiple rigid modules whose relative orien- tations and positions are in slight fluctuation around equilibriums, we propose a new method called as local optimization refinement to address this conformational heterogeneity for an improved resolution. The key idea is to optimize the orientation and shift parameters of each rigid module and then reconstruct their three-dimen- sional structures individually. Using simulated data of 80S/70S ribosomes with relative fluctuations between the large （60S/50S） and the small （40S/30S） subunits, we tested this algorithm and found that the resolutions of both subunits are significantly improved. Our method provides a proof-of-principle solution for high-resolutionsingle particle analysis of macromolecular complexes with dynamic conformations.

Synthesis of 3-acylindoles via decarboxylative cross-coupling reaction of free(N–H) indoles with α-oxocarboxylic acids

A convenient and general method for acylation of free （N-H） indoles via palladium-catalyzed decarboxylative cross-coupling reaction was developed. This process provided a useful method for the preparation of diverse 3-acylindoles in high yields utilizing a reaction with readily accessible reactants under mild conditions,

Clinical characteristics of four cancer patients with SARS-CoV-2 infection in Wuhan, China

Background The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)led to the outbreak of pneumonia in Wuhan.The virus is highly infectious.Patients with cancer might be susceptible to the viral infection because of the immunosuppressive state cause by therapies on tumors.Case presentation We present the clinical features of four cancer patients who were infected with SARS-CoV-2 in late January of 2020 in our hospital.Cases 1 and 3 were diagnosed as mild and common type of coronavirus disease 2019(COVID-2019)and survived from the viral infection.They acquired SARS-CoV-2 infection during their staying in hospital under radiotherapy and surgery of the tumors.Cases 2 and 4 suffered from severe type of COVID-19,and Case 2 was dead owning to the advanced age,uncontrolled chronic B cell lymphocytic leukemia and many other underlying diseases.The immunosuppressive state induced by liver transplantation and anti-rejection therapy might contribute to the severity of COVID-19 in Case 4,who suffered from hepatitis B related hepatocellular carcinoma.However,Case 4 was recovered from COVID-19 after a combination therapy against virus,bacteria and fungi,and also respiratory support.Nearly all patients showed a decrease in lymphocytes including total CD3+T cells,B cells,and natural killer cells after infection of the virus.Conclusions The severity of COVID-19 might be influenced by immune system state and underlying diseases in cancer patients.And the treatment of SARS-CoV-2 infection in cancer patients is challenged by the immunosuppressive state of these patients under chemotherapy or surgery.