MoS_2催化的球磨态REMg_(11)Ni(RE=Y,Sm)合金的储氢性能（英文）

制备MoS 2催化作用下的球磨态REMg11Ni-5MoS2(质量分数)(RE=Y,Sm)合金,用以比较其储氢性能。储氢性能通过多种方法测定,包括XRD、TEM、自动Sievert设备、TG和DSC。结果显示,两种球磨态的合金都具有纳米晶和非晶结构。与RE=Sm合金相比,RE=Y合金具有较大的吸氢量、较快的吸氢速率、较低的初始放氢温度、较好的放氢性能和较低的放氢活化能,其中较低的放氢活化能被视为其具备较好储氢动力学的原因。

Biotransformation of aesculin by human gut bacteria and identification of its metabolites in rat urine

AIM:To observe the biotransformation process of a Chinese compound,aesculin,by human gut bacteria,and to identify its metabolites in rat urine.METHODS:Representative human gut bacteria were collected from 20 healthy volunteers,and then utilized in vitro to biotransform aesculin under anaerobic conditions.At 0,2,4,8,12,16,24,48 and 72 h post- incubation,10 mL of culture medium was collected.Metabolites of aesculin were extracted 3×from rat urine with methanol and analyzed by HPLC.For in vivo metabolite analysis,aesculetin(100 mg/kg)was administered to rats via stomach gavage,rat urine was collected from 6 to 48 h post-administration,and metabolite analysis was performed by LC/ESI-MS and MS/MS in the positive and negative modes.RESULTS:Human gut bacteria could completely convert aesculin into aesculetin in vitro.The biotransformation process occurred from 8 to 24 h post-incubation,with its highest activity was seen from 8 to 12 h.The in vitro process was much slower than the in vivo process.In contrast to the in vitro model,six aesculetin metabolites were identified in rat urine,including 6-hydroxy-7-gluco- coumarin(M1),6-hydroxy-7-sulf-coumarin(M2),6,7-di- gluco-coumarin(M3),6-glc-7-gluco-coumarin(M4),6-O-methyl-7-gluco-coumarin(M5)and 6-O-methyl-7- sulf-coumarin(M6).Of which,M2 and M6 were novel metabolites.CONCLUSION:Aesculin can be transferred into aesculetin by human gut bacteria and is further modified by the host in vivo.The diverse metabolites of aesculin may explain its pleiotropic pharmaceutical effects.

Expressions of Nucleoside Diphosphate Kinase (nm23) in Tumor Tissues are Related with Metastasis and Length of Survival of Patients with Hepatocellular Carcinoma

Objective To evaluate the relationship of expressions of nucleoside diphosphate kinase （nm23） and proliferating cell nuclear antigen （PCNA）, as well as apoptosis, with the prognosis of HCC patients by analyzing their pathological and clinical data. Methods The expressions of nm23 and PCNA were analyzed by immunohistochemistry and the apoptotic phenomena were detected by TUNEL technique in the liver samples from 43 HCC tissues, 39 para-neoplastic tissues, and 10 normal tissues. The mean apoptosis index （AI） and proliferative index （PI） in individual sample were calculated. Results As shown by the detection, 32.6% of carcinomas had negative nm23 signal in tumor tissues, whereas all para-neoplastic and normal tissues had positive nm23. The AI in nm23 positive HCC was significantly higher than that in nm23 negative one, with statistical difference （P0.05）. Furthermore, the expressions of nm23, and the values of AI and PI were contrastively analyzed with some main pathological and clinical data of HCC. It revealed that HCC with extrahepatic metastasis showed remarkable correlation with the negative nm23 （P=0.013） and higher PI values of HCC （P=0.015）. The disease-free survival in HCC patients with negative nm23 expression was significantly poorer than that in patients with positive nm23 expression. Conclusion These data suggest that expressions of nm23 protein in tumor tissues are correlated with occurrences of metastasis and length of survival of the HCC patients, which may be an indicator for their prognosis.

Molecular Epidemiological Study on Prevalence of Human Papillomaviruses in Patients with Common Warts in Beijing Area

Objective To study the circulation, distribution, and genomic diversity of HPVs in common warts in Beijing area of China. Methods Forty eight patients with pathologically diagnosed common warts were screened for the presence of HPV with HPV type-specific PCR and direct sequencing analysis. The genomic diversity of HPVs prevalent in Chinese patients was analyzed based on LCR. Results Forty one （85.5%） samples were positive for HPV DNA, 13（31.7%）-HPV-57, 12（29.3%）-HPV-la, 7（17%）-HPV-27 and 5（12.2%）-HPV-2a. Four cases were infected with two different HPV types, two （4.9%） with HPV-la and HPV-27, one （2.4%） with HPV-1 and HPV-57 and one （2.4%） with HPV-27 and HPV-57. In contrast to the prevalence of single strain of novel HPV-57 variant and HPV-1 prototype, two HPV-2 and three HPV-27 novel variants were found to circulate in Beijing. Conclusion HPV-1, -2, -27 and -57 are predominantly prevalent in patients with common warts in Beijing.

Establishment of a Sandwich ELISA Method for Detection of Vascular Endothelial Growth Factor in Serum Samples of Hepatocellular Carcinoma Patients

Objective To establish a sandwich ELISA method for detecting vascular endothelial growth factor （VEGF） in sera of population and the patients with hepatocellular carcinoma （HCC）. Methods Full length and two truncated human VEGF cDNA sequences were amplified from a commercial plasmid pBLAST49-hVEGF by PCR and inserted into the prokaryotic-expression plasmid pET-32a or pGEX-2T. Various VEGF proteins were expressed and purified from E. coli in His-Trx or GST fusion forms. The specific VEGF antibodies were elicited in experimental rabbits and mice by immunization of the full length VEGF fusion protein His-Trx-VEGF1-165. After purification of antibodies with chromatograph of Protein G, a sandwich ELISA technique was established. Serum VEGF levels were evaluated in 229 adults and 291 HCC patients. Results SDS-PAGE displayed that the molecular weights of the expressed full length （His-Trx-VEGF1-165）, N-terminal （His-Trx-VEGF1-100） and C-terminal （GST-VEGF100-165） human VEGF fusion proteins were about 38KD, 31KD, and 33KD, respectively. Western blots confirmed that the prepared antisera were able to recognize both prokaryoticly and eukaryoticly expressed recombinant VEGF proteins. Assays of serially diluted His-Trx-VEGF1-100 by the established sandwich ELISA method showed that the linear range of the standard curve was 0.625-320 ng/mL, with the squared correlation coefficient R^2=0.991. Screening of a serum panel containing 291 serum samples of HCC patients and 229 health adults revealed that the average VEGF level in HCC patients was higher than that in healthy controls, with a statically significant difference. Conclusion The established sandwich ELISA reflects the level of serum VEGF and provide scientific basis for screening metastasis and recurrence of HCC using serum VEGF as an index.

Treatment of Scrapie Pathogen 263K With Tetracycline Partially Abolishes Protease-resistant Activity in vitro and Reduces Infectivity in vivo

Objective To study the possible effect of tetracycline on protease-resistant activity in vitro and infectivity in vivo of a scrapie strain 263K. Methods Scrapie pathogens were incubated with tetracycline at different concentrations for various periods of time and protease-resistant PrP signals were evaluated with proteinase K-treatment and Western blots. The preparations treated with tetracycline were intracerebrally inoculated into golden hamsters and typical TSE manifestations were noted. PrP^5c in brain tissues of the infected animals was detected by PrP specific Western blot assays. Results Protease-resistant PrP was significantly reduced in or removed from the preparations treated with tetracycline in a dose-dependant manner. Compared with the control group after incubated for 53.75±0.50 days, the preparations treated with 5 mmol/L and 20 mmol/L tetracycline prolonged the incubation time of 61.5±1.73 and 59.5±0.58 days （P〈0.05）. Conclusion Treatment of scrapie pathogen 263K with tetracycline reduces or removes its protease-resistant activity in vitro.

Establishment of Cell Free Conversion System With Biotin-labelled Recombinant PrP^(sen) Expressed in E.coli

Objective To report a protocol using biotin-labelled PrP protein in cell free conversion assay instead of isotope. Methods A hamster PrP protein （HaPrP） was expressed in E. coli and purified with HIS-tag affinity chromatograph. After being labelled with biotin, HaPrP was mixed with PrP^sen preparation from scrapie strain 263K. Results Protease-resistant bands were detected after four-day incubation. Conclusion The new conversion model provides a reliable, easily handling, and environment-friendly method for studies of prion and transmissible spongiform encephalopathies.

Preparation of Monoclonal Antibodies Against Prion Proteins With Full-length Hamster PrP

To prepare the PrP specific monoclonal antibodies （mAbs） that can be used for the detection of mammalian prions and study of pathogenesis of prion diseases. Methods Several BALB/c mice were immunized with recombinant hamster prion protein （HaPrP）. Three hybridoma cell lines designated as B7, B9, and B10, secreting monoclonal antibodies against HaPrP, were established by hybridoma technique. The mAbs reactivities were evaluated with ELISA, Western blot, and immunohistochemistry. Results The mAbs produced by these cell lines reacted well with different recombinant hamster PrP proteins. Western blot analyses showed that mAbs B7 and B9 reacted with PrP^Sc from the scrapie-infected animals after proteinase K digestion with three glycosylated forms. The mAbs exhibited cross-reactivity with various PrPc from several other mammalian species, including humans and cattles, lmmunohistochemistry assays confirmed that mAbs B7 and B9 could recognize not only extracellular but also intracellular PrPso. Conclusion The mAbs of prion protein are successfully generated by hybridoma technique and can be applied for the diagnosis of prion associated diseases.

Epidemiological Investigation of Human Papillomavirus Infection in Men Attending a Sexually Transmitted Disease Clinic in Hangzhou Area

Objective To investigate the epidemiological characteristics of human papillomavirus （HPV） infection in men attending a sexually transmitted diseases （STD） clinic in Hangzhou area. Methods Male subjects （n=375） aged 18-70 years, attending the STD clinic were recruited. Urethral swabs were assessed for HPV DNA using polymerase chain reaction （PCR） with the consensus primers MY09/11. HPV genotypes of positive PCR products were determined by restriction fragment length polymorphisms and direct sequence analysis. Results Of the 375 swabs collected, 305 （81.3%） yielded sufficient DNA for the subsequent HPV analysis. Among the 305 subjects, the prevalence of HPV was 13.8%. Nononcogenic HPV types were found in 8.5% （26/305） of subjects, oncogenic types in 4.3% （13/305）, and multiple types in 1.0% （3/305）. The prevalence of HPV infection was higher in subjects from urban area than in those from rural area （P〈0.05）. The prevalence was also higher in those who received fewer years of education （P〈0.05） and those who had more sex partners （P〈0.05）. Conclusions HPV infection among men at high risk is not uncommon. The detection rate of HPV DNA is significantly related to some sociodemographic factors, such as residence, educational level and the number of sex partners.

Spatiotemporal visualization for the global COVID-19 surveillance by balloon chart

Background:Considering the widespread of coronavirus disease 2019(COVID-19)pandemic in the world,it is important to understand the spatiotemporal development of the pandemic.In this study,we aimed to visualize time-associated alterations of COVID-19 in the context of continents and countries.

Epidemiological characteristics of human prion diseases

Human prion diseases are a group of transmissible,progressive,and invariably fatal neurodegenerative disorders,which include Kuru,Creutzfeldt-Jakob disease(CJD),Gerstmann-Sträussler-Scheinker syndrome,and fatal familial insomnia.Human prion diseases affect approximately 1–2 persons per million worldwide annually,occurring in sporadic,inherited,and acquired forms.These diseases have attracted both scientific and public attention not only because of their mysterious pathogen,but also due to their considerable threat to public health since the emergence of the variant CJD.There are still no specific therapeutic and prophylactic interventions available for prion diseases,thus active surveillance of human prion diseases is critical for disease control and prevention.Since 1993,CJD surveillance systems have been established in many countries and regions,and several long-term multinational cooperative projects have been conducted.In this paper,the epidemiological characteristics of various human prion diseases and the active surveillance systems pertaining to them in different countries and regions are summarized and reviewed.

T188K-Familial Creutzfeldt–Jacob Disease, Predominant Among Chinese, has a Reactive Pattern in CSF RT-QuIC Different from D178N-Fatal Familial Insomnia and E200K-Familial CJD

Dear Editor,Human prion diseases consist of sporadic, genetic/familial, and acquired forms. The familial form accounts for 5%-15% of all human prion diseases, including familial Creutzfeldt- Jacob disease (fCJD), Gerstmann-Straussler-Scheinker syndrome, and fatal familial insomnia (FFI)[1-3]. All genetic prion diseases are directly associated with mutations (point-mutation or insertion) in the PRNP gene located on human chromosome 20 and encodes prion protein (PrP). So far,>55 mutations in the PRNP gene have been described [4]. Some PRNP mutations and their related genetic prion diseases have been reported worldwide, while others show clear region- or ethnicity-associated features.

Good laboratory practices guarantee biosafety in the Sierra Leone-China friendship biosafety laboratory

Background:The outbreak of Ebola virus disease(EVD)in West Africa between 2014 and 2015 was the largest EDV epidemic since the identification of Ebola virus(EBOV)in 1976,and the countries most strongly affected were Sierra Leone,Guinea,and Liberia.Findings:The Sierra Leone-China Friendship Biological Safety Laboratory(SLE-CHN Biosafety Lab),a fixed Biosafety Level 3 laboratory in the capital city of Sierra Leone,was established by the Chinese government and has been active in EBOV detection since 11 March 2015.Complete management and program documents were created for the SLE-CHN Biosafety Lab,and it was divided into four zones(the green,yellow,brown,and red zones)based on the risk assessment.Different types of safe and appropriate personnel protection equipment(PPE)are used in different zones of the laboratory,and it fully meets the Biosafety Level 3 laboratory standards of the World Health Organization.Conclusion:Good preparedness,comprehensive risk assessment and operation documents,appropriate PPE,effective monitoring and intensive training,together with well-designed and reasonable laboratory sectioning are essential for guaranteeing biosafety.

IP10, KC and M-CSF Are Remarkably Increased in the Brains from the Various Strains of Experimental Mice Infected with Different Scrapie Agents

Activation of inflammatory cells and upregulations of a number of cytokines in the central nervous system(CNS)of patients with prion diseases are frequently observed.To evaluate the potential changes of some brain cytokines that were rarely addressed during prion infection,the levels of 17 different cytokines in the brain homogenates of mice infected with different scrapie mouse-adapted agents were firstly screened with Luminex assay.Significant upregulations of interferon gamma-induced protein 10(IP10),keratinocyte chemoattractant(KC)and macrophage colony stimulating factor(M-CSF)were frequently detected in the brain lysates of many strains of scrapie infected mice.The upregulations of those three cytokines in the brains of scrapie infected mice were further validated by the individual specific ELISA and immunohistochemical assay.Increased specific mRNAs of IP10,M-CSF and KC in the brains of scrapie infected mice were also detected by the individual specific qRT-PCRs and IP10-specific digital PCR.Dynamic analyses of the brain samples collected at different time points post infection revealed the time-dependent increases of those three cytokines,particularly IP10 during the incubation period of scrapie infection.In addition,we also found that the levels of IP10 in cerebral spinalfluid(CSF)of 45 sporadic Creutzfeldt–Jakob disease(sCJD)patients were slightly but significantly higher than those of the cases who were excluded the diagnosis of prion diseases.These data give us a better understanding of inflammatory reaction during prion infection and progression of prion disease.

Genetic Prion Disease:Insight from the Features and Experience of China National Surveillance for Creutzfeldt-Jakob Disease

Human genetic prion diseases(gPrDs)are directly associated with mutations and insertions in the PRNP(Prion Protein)gene.We collected and analyzed the data of 218 Chinese gPrD patients identified between Jan 2006 and June 2020.Nineteen different subtypes were identified and gPrDs accounted for 10.9%of all diagnosed PrDs within the same period.Some subtypes of gPrDs showed a degree of geographic association.The age at onset of Chinese gPrDs peaked in the 50–59 year group.Gerstmann–Sträussler–Scheinker syndrome(GSS)and fatal familial insomnia(FFI)cases usually displayed clinical symptoms earlier than genetic Creutzfeldt–Jakob disease(gCJD)patients with point mutations.A family history was more frequently recalled in P105L GSS and D178N FFI patients than T188K and E200K patients.None of the E196A gCJD patients reported a family history.The gCJD cases with point mutations always developed clinical manifestations typical of sporadic CJD(sCJD).EEG examination was not sensitive for gPrDs.sCJD-associated abnormalities on MRI were found in high proportions of GSS and gCJD patients.CSF 14-3-3 positivity was frequently detected in gCJD patients.Increased CSF tau was found in more than half of FFI and T188K gCJD cases,and an even higher proportion of E196A and E200K gCJD patients.63.6%of P105L GSS cases showed a positive reaction in cerebrospinal fluid RT-QuIC.GSS and FFI cases had longer durations than most subtypes of gCJD.This is one of the largest studies of gPrDs in East Asians,and the illness profile of Chinese gPrDs is clearly distinct.Extremely high proportions of T188K and E196A occur among Chinese gPrDs;these mutations are rarely reported in Caucasians and Japanese.

COVID-19 seeding time and doubling time model:an early epidemic risk assessment tool

Background:As COVID-19 makes its way around the globe,each nation must decide when and how to respond.Yet many knowledge gaps persist,and many countries lack the capacity to develop complex models to assess risk and response.This paper aimed to meet this need by developing a model that uses case reporting data as input and provides a four-tiered risk assessment output.Methods:We used publicly available,country/territory level case reporting data to determine median seeding number,mean seeding time(ST),and several measures of mean doubling time(DT)for COVID-19.We then structured our model as a coordinate plane with ST on the x-axis,DT on the y-axis,and mean ST and mean DT dividing the plane into four quadrants,each assigned a risk level.Sensitivity analysis was performed and countries/territories early in their outbreaks were assessed for risk.Results:Our main finding was that among 45 countries/territories evaluated,87%were at high risk for their outbreaks entering a rapid growth phase epidemic.We furthermore found that the model was sensitive to changes in DT,and that these changes were consistent with what is officially known of cases reported and control strategies implemented in those countries.Conclusions:Our main finding is that the ST/DT Model can be used to produce meaningful assessments of the risk of escalation in country/territory-level COVID-19 epidemics using only case reporting data.Our model can help support timely,decisive action at the national level as leaders and other decision makers face of the serious public health threat that is COVID-19.

Low activity of complement in the cerebrospinal fluid of the patients with various prion diseases

Background:The aim of this study was to analyze the state of activity and levels of complement in the cerebrospinal fluid(CSF)of patients with various prion diseases(PrDs).Findings:The proteomic data emphasized the levels of 20 known complement components found in the CSF of the sCJD panel that were lower than those found in the non-PrD panel.50%of the complement hemolytic activity(CH50)assays revealed significantly lower activity of complement in the CSF of the sCJD panel.The decreased levels of three key complement subunits,C3a/α,C4β,and C9 in the CSF of the sCJD panel were verified by Western blots.Furthermore,the CH50 values in the CSF of 136 sCJD,39 gCJD,22 FFI and 145 non-CJD patients were individually tested.Compared with the control of non-PrD,the CH50 value in the CSF specimens of various PrDs,especially in three subtypes of inherited PrDs,were significantly lower.Relationship analysis identified that the CH50 activity in the CSF was negatively associated with the protein 14–3–3 positive in the CSF.Conclusion:These results indicate a silent complement system in the CSF of PrD patients.

Operational research capacity building through the Structured Operational Research Training Initiative(SORT-IT)in China:implementation,outcomes and challenges

Background:Chinese Center for Disease Control and Prevention(China CDC)introduced the Structured Operational Research Training Initiative(SORT IT)into China to build a special capacity and equip public health professionals with an effective tool to support developing countries in strengthening their operational research.The paper aims to investigate and analyze the implementation,outcomes and challenges of the first cycle of SORT IT in China.

Expert Consensus on Clinical Diagnostic Criteria for Fatal Familial Insomnia

INTRODUCTION Fatal familial insomnia （FFI） is a serious and rare prion disease, which was first reported by Lugaresi et al. in 1986.Early diagnosis of FFI might be important for early and sufficient counseling of patients and their relatives, also concerning the risk of inheritance, and potentially also for treatment studies. However, the diagnosis of FFI might be difficult because of the heterogeneity of clinical features, low sensitivity of diagnostic tests, and absence of family history. The aim of the present study was to develop a clinical scheme and diagnostic criteria for FFI based on our research and expert consensus.

Structure and electrochemical performances of as-milled LaMg12-type alloy-Ni composites

LaMg11Ni+x wt.%Ni(x=100,200)alloys were prepared by ball milling and researched by various methods to study their structure and electrochemical hydrogen storage property.The outcomes reveal that increasing Ni content contributes to improving its electrochemical performance.Particularly,the discharge capacity of as-milled(40 h)alloy will be increased from 157.3 to 1053.5 mAh/g through enhancing Ni percentage from 100 to 200 wt.%when discharging at 60 mAh/g.Ball milling obviously affects the electrochemical performanee of alloys.With milling duration prolonging,the discharge capacity of x=100 alloy keeps increasing,while that of the x=200 alloy has a maximum value.Milling time also affects the cycle stability of experimental alloys.Extendi ng milli ng duration clearly decreases the cycle stability of x=100 alloy but weakens that of the x=200 alloy at first and strengthens it later.In addition,prolonging milling time makes the milling prepared x=100 and 200 alloys get the maximal values of high rate discharge ability of 81.60%and 84.52%,respectively.