Extremely low frequency electromagnetic fields(ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood.In this s...Extremely low frequency electromagnetic fields(ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood.In this study, we established rat models of middle cerebral artery occlusion/reperfusion.One day after modeling, a group of rats were treated with ELF-EMF(50 Hz, 1 mT) for 2 hours daily on 28 successive days.Our results showed that rats treated with ELF-EMF required shorter swimming distances and latencies in the Morris water maze test than those of untreated rats.The number of times the platform was crossed and the time spent in the target quadrant were greater than those of untreated rats.The number of BrdU~+/NeuN~+ cells, representing newly born neurons, in the hippocampal subgranular zone increased more in the treated than in untreated rats.Up-regulation in the expressions of Notch1, Hes1, and Hes5 proteins, which are the key factors of the Notch signaling pathway, was greatest in the treated rats.These findings suggest that ELF-EMF can enhance hippocampal neurogenesis of rats with cerebral ischemia, possibly by affecting the Notch signaling pathway.The study was approved by the Institutional Ethics Committee of Sichuan University, China(approval No.2019255A) on March 5, 2019.展开更多
This study is based on meteorological observation data collected at 38 weather stations on the Tibetan Plateau over several decades. Daily reference crop evapotranspiration （ETo） was calculated with the FAO-56 stand...This study is based on meteorological observation data collected at 38 weather stations on the Tibetan Plateau over several decades. Daily reference crop evapotranspiration （ETo） was calculated with the FAO-56 standard Penman-Monteith formula. A test of normality was performed with Statistica 6.0 software, isotropic and anisotropic semi-variogram analysis was conducted with the GS＋ （geostatistics for the environmental sciences） system for Windows 7.0, and the characteristics of spatial variation of daily ETo were obtained. The following results can be obtained Daily ETo for different periods on the Tibetan Plateau are distributed normally; Except for daily ETo in the E-W （east-west） direction in the summer, which showed a slight negative correlation with distance change, the Moran＇s indexes of daily ETo for different periods in all directions on the Tibetan Plateau within a 100-km distance were positive, demonstrating a positive correlation with distance change; Variograms of daily ETo in June, the dry season, the wet season, as well as annual average daily ETo fit well with the Gaussian model; A variogram of daily ETo in December fit well with the exponential model; Variograms of daily ETo for the four seasons fit well with the linear With sill model.展开更多
Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy ma...Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy mathematics is improved based on a previous study.First,the single-factor membership degree is determined using the dynamic clustering method,then a single-factor evaluation matrix is constructed using a continuous grading function,and finally,the probability distribution of the evaluation grade in a fuzzy evaluation matrix is analyzed.In this study,taking the F1 fault located in the northeastern Chepaizi Bulge as an example,the sealing properties of faults in different strata are quantitatively evaluated using both an improved and an un-improved comprehensive fuzzy mathematics quantitative evaluation method.Based on current oil and gas distribution,it is found that our evaluation results before and after improvement are significantly different.For faults in＂best＂and＂poorest＂intervals,our evaluation results are consistent with oil and gas distribution.However,for the faults in＂good＂or＂poor＂intervals,our evaluation is not completelyconsistent with oil and gas distribution.The improved evaluation results reflect the overall and local sealing properties of target zones and embody the nonuniformity of fault sealing,indicating the improved method is more suitable for evaluating fault sealing under complicated conditions.展开更多
A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate (Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits high isotactic tacticity.
Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by s...Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by species and from different plant tissues (roots, stems, leaves, flowers and fruits) in each species, a total of 25 isoflavones were identified by their molecular ions and characteristic fragment ion peaks using LC/MSD under MS and MS/MS mode, and in comparison with standard isoflavones. Two main chemical groups were identified: 1) 8-C-glycosyl isoflavone of puerarin and the analogues of 5-OH puerarin, 3’-OH puerarin, 3’-OMe puerarin, and their glycosides;and 2) daidzein, genistein, glycitein and their glycosyl and malonyl derivatives, which are similar to those known in soy. To accurately quantitate total isoflavones, acidic hydrolysis during extraction of kudzu samples was applied to convert the oxygen glycosides into their respective isoflavone aglycones of daidzein, genistein and glycitein, or non-hydrolyzed carbon glycosides of puerarin, 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin. Under the multiple optimized conditions, all seven isoflavones in acidic hydrolyzed kudzu extracts were successfully separated within 30 min and quanti- fied individually with calycosin used as internal standard by both UV and MS detectors. For the quantitative study, several standards e.g. 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin are not commercially available. Using polyamide, sephdex-LH20 chromatography and Prep-HPLC, we purified these three stan- dards from kudzu extracts and then elucidated their structures by UV, MS and NMR spectrometric methods. This is the first method to simultaneously quantitate all the isoflavones in kudzu.展开更多
Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) pro...Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum. Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024. Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.展开更多
It has been more than 3 years since the novel coronavirus(SARS-CoV-2)pandemic raged globally.The coronavirus disease 2019(COVID-19)has greatly influenced human society.According to data from the World Health Organizat...It has been more than 3 years since the novel coronavirus(SARS-CoV-2)pandemic raged globally.The coronavirus disease 2019(COVID-19)has greatly influenced human society.According to data from the World Health Organization(WHO),there were over 656 million confirmed cases of COVID-19 in the world as of January 1,2023,including over 6.6 million deaths[1].展开更多
2A97 Al-Li alloy was cold-rolled to 2 mm and then thermally exposed at different temperatures for 1 h and at 723 K for different time,respectively.The texture evolution behavior and the anisotropy of 2A97 Al-Li alloy ...2A97 Al-Li alloy was cold-rolled to 2 mm and then thermally exposed at different temperatures for 1 h and at 723 K for different time,respectively.The texture evolution behavior and the anisotropy of 2A97 Al-Li alloy were investigated.The result shows that the{001}<120>and{011}<233>textures are the dominant recrystallization texture.The{124}<211>texture is the final recrystallization texture.In case of low-temperature thermal exposure(473,573 K),the{011}<211>texture is aggregated to the{112}<111>and{123}<634>textures.During the recrystallization at 723 K,the{001}<110>,{111}<112>and{011}<100>textures are the intermediate transition grain orientations.The concurrent precipitation of Al_(20)Cu_(2)Mn_(3)and Al_(3)Zr results in the occurrence of unusually sharp{011}<233>and{001}<120>texture components during recrystallization.The alloy with both recrystallization and deformation texture possesses the smallest anisotropic,and the texture is the direct reason that results in the anisotropy.展开更多
Monkeypox is a zoonotic disease.Since the first human monkeypox case was detected in 1970,it has been prevalent in some countries in central and western Africa.Since May 2022,monkeypox cases have been reported in more...Monkeypox is a zoonotic disease.Since the first human monkeypox case was detected in 1970,it has been prevalent in some countries in central and western Africa.Since May 2022,monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide.As of September 14,2022,there have been more than 58,200 human monkeypox cases,and there is community transmission.The cessation of smallpox vaccination in 1980,which had some cross-protection with monkeypox,resulted in a general lack of immunity to monkeypox,which caused global concern and vigilance.As of Sep-tember 14,2022,there are four monkeypox cases in China,including three in Taiwan province and one in Hong Kong city.Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications.In order to improve pediatricians'understanding of monkeypox and achieve early detection,early diagno-sis,early treatment,and early disposal,we have organized national authoritative experts in pediatric infection,respiratory,dermatology,critical care medicine,infectious diseases,and public health and others to formulate this expert consensus,on the basis of the latest"Clinical management and infection prevention and control for monkeypox"released by The World Health Organization,the"guidelines for diagnosis and treatment of monkeypox(version 2022)"issued by National Health Commission of the People's Republic of China and other relevant documents.During the development of this consensus,multidisciplinary experts have repeatedly demonstrated the etiology,epidemiology,transmission,clinical manifestations,laboratory examinations,diagnosis,differential diagnosis,treatment,discharge criteria,prevention,disposal process,and key points of prevention and control of suspected and confirmed cases.展开更多
Background Increasing numbers of pertussis cases have been reported in recent years.The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China.The epidemiology of antigenic ...Background Increasing numbers of pertussis cases have been reported in recent years.The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China.The epidemiology of antigenic genotype and antibiotic resistance of circulating strains in children have been unknown in Shenzhen,southern China.The aim of this study was to describe the clinical features and explore the genotypes and antimicrobial susceptibility of circulating Bordetella pertussis among children in Shenzhen.Methods Data of hospitalized children with pertussis in Shenzhen Children's Hospital from August 2015 to April 2017 were collected.The genetic variability of isolates was investigated and Etest was performed for phenotypic susceptibility to erythromycin,azithromycin,clarithromycin,clindamycin,and trimethoprim/sulfamethoxazole.Results 469 children with pertussis confirmed by real-time quantitative polymerase chain reaction were hospitalized and strains were isolated from 105 patients.White blood cell count≥20×10^9/L and lymphocyte proportion≥60%were observed in 39.29%of infants younger than 3 months.The two predominant profiles of virulence-associated allelic genes were ptxA1/ptxC1/ptxPl/prnl(48.6%)and ptxA1/ptxC2/ptxP3/prn2(44.8%).Among the isolates,48.6%(51/105)were found resistant to macrolides.Conclusions These findings indicate that leukocytosis is not a sensitive indicator of pertussis.Isolates with the gene profile ptxP3/prn2 were highly circulating in Shenzhen and less resistant to macrolides,different from patterns observed in other parts of China.展开更多
In the early February,2020,we called up an experts' committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement on diagnosis,tr...In the early February,2020,we called up an experts' committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement on diagnosis,treatment and prevention of coronavirus disease 2019 (COVID-19) in children,which has been published in this journal.With accumulated experiences in the diagnosis and treatment of COVID-19 in children,we have updated the consensus statement and released the second edition recently.The current version in English is a condensed version of the second edition of consensus statement on diagnosis,treatment and prevention of COVID-19 in children.In the current version,diagnosis and treatement criteria have been optimized,and early identification of severe and critical cases is highlighted.The early warning indicators for severe pediatric cases have been summarized which is utmost important for clinical practice.This version of experts consensus will be valuable for better prevention,diagnosis and treatment of COVID-19 in children worldwide.展开更多
The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronav...The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronavirus genera.On January 30,2020,WHO re-evaluated the potential effects of 2019-nCoV infection in global public health,and declared this epidemic as a "Public Health Emergency of International Concern (PHEIC)".展开更多
Background Children as a population have high antimicrobial prescribing rates which may lead to high resistance of bacteria according to data from some single-center surveys of antibiotic prescribing rates in China. T...Background Children as a population have high antimicrobial prescribing rates which may lead to high resistance of bacteria according to data from some single-center surveys of antibiotic prescribing rates in China. The acquirement of baseline data of antibiotic prescribing is the basis of developing intervention strategies on inappropriate antimicrobial prescriptions. Few studies show clearly the pattern and detailed information on classes of antibiotics and distribution of indications of antibiotic prescriptions in children in China. This study aims to assess the antibiotic prescribing patterns among children and neonates hospitalized in 18 hospitals in China. Methods A 24-hour point prevalence survey on antimicrobial prescribing was conducted in hospitalized neonates and chil-dren in China from December 1st, 2016 to February 28th, 2017. Information on the antibiotic use of patients under 18 years of age who were administered one or more on-going antibiotics in the selected wards over a 24-hour period was collected. These data were submitted to the GARPEC (Global Antimicrobial Resistance, Prescribing and Efficacy in Children and Neonates) web-based application ( https ://pidrg -datab ase.sgul.ac.uk/redca p/ ). For statistical analysis, Microsoft Excel 2007 and SPSS 22.0 were used. Results The antibiotic data were collected in 35 wards in 18 hospitals from 9 provinces. In total, 67.76% (975/1439) of the patients (n = 1439) were given at least one antibiotic, including 58.1% (173/298) of neonates (n = 298) and 70.3% (802/1141) of children (n = 1141). In neonates, the three most frequently prescribed antibiotics were third-generation cephalosporins (41.7%), penicillins plus enzyme inhibitor (23.8%), and carbapenems (11.2%). In children, the three most frequently pre-scribed antibiotics were third-generation cephalosporins (35.5%), macrolides (23.2%), and penicillins plus enzyme inhibi-tors (15.9%). The most common indication for antibiotics was proven or probable bacterial lower respiratory tract infection (30.9% in neonates and 66.6% in children). Conclusions Antibiotics are commonly prescribed in the Chinese children population. It is likely that the third-generation cephalosporins and macrolides are currently overused in Chinese children. Efforts must be made to ensure safe and appropri-ate antibiotic prescribing to reduce and prevent the future development of antibiotic resistance.展开更多
Background The clinical use of gentamicin always lies in its antimicrobial activity in the past as an aminoglycoside antibiotic.However,in the past decade,there were considerable interests in therapeutic approaches in...Background The clinical use of gentamicin always lies in its antimicrobial activity in the past as an aminoglycoside antibiotic.However,in the past decade,there were considerable interests in therapeutic approaches in treating hereditary diseases.Some of the genodermatosis is caused by nonsense mutations that create premature termination codons and lead to the production of truncated or non-functional proteins.Gentamicin could induce readthrough of nonsense mutations and enable the synthesis of full-length proteins.We focus on previous publications on topical application of gentamicin and review its utility in genetic skin diseases.Data sources We search the MEDLINE through PubMed,EMBASE databases,and the Clinical Trials Registry Platform from January 1960 to July 2020 using the key search terms"gentamicin,topical gentamicin,genodermatosis,genetic skin diseases".Results The application of gentamicin in genodermatosis yielded promising results,both in vivo and in vitro,including Nagashima-type palmoplantar keratosis,epidermolysis bullosa,Hailey-Hailey disease,hereditary hypotrichosis simplex of the scalp,etc.Conclusions Topical gentamicin is a potential treatment option for genodermatosis caused by nonsense mutation.展开更多
Antimicrobial resistance (AMR) has been declared a major threat to global health, with the potential to reverse advances in treating disease, and impeding other global pri-orities including human development. The urge...Antimicrobial resistance (AMR) has been declared a major threat to global health, with the potential to reverse advances in treating disease, and impeding other global pri-orities including human development. The urgent menace of AMR has been recognized by the World Health Organi-sation Global Action Plan in 2015 [1], the 2016 United Nations General Assembly unanimous commitment to tackle AMR [2], and the Association of Southeast Asian Nations (ASEAN) 2017 declaration on AMR (3)AMR has been highlighted as a major health and economic challenge, with the consequences of failing to meet that challenge falling upon our children and grandchildren. Not only will children bear the burden of rising AMR, they are especially at risk now due to a number of factors. In many studies, children and the elderly are the highest consumers of antimicrobi-als (4)In addition, frequently inappropriate doses in chil-dren mean that they are receiving sub-therapeutic doses, maximizing the chance of encouraging resistant organ-isms to flourish. The normal behaviour of early childhood also encourages the spread of resistant organisms between children. Finally, their lifetime risk of exposure to resistant organisms is higher than adults.展开更多
Coronavirus disease 2019(COVID-19)is a public health disaster that has not been encountered for a hundred years.On January 12,2020,the World Health Organization(WHO)confirmed and named the coronavirus which caused une...Coronavirus disease 2019(COVID-19)is a public health disaster that has not been encountered for a hundred years.On January 12,2020,the World Health Organization(WHO)confirmed and named the coronavirus which caused unexplained pneumonia as 2019 novel coronavirus(2019-nCoV).Since then,the disease caused by this virus had been named as coronavirus disease 2019(COVID-19).On February 11,2020,the International Committee on Taxonomy of Viruses announced that the English name of the novel coronavirus was severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)[1].At present,SARS-CoV-2 infection is still rampant worldwide.As of September 10,2021,there were about 222 million confirmed cases of COVID-19 and more than 4.5 million deaths worldwide[2].According to the American Centers for Disease Control and Prevention,by July 29,2021,4.19 million pediatric COVID-19 cases had been reported in the United States。展开更多
Coronavirus disease 2019(COVID-19)remains a global epidemic.As of August 18,2021,the number of reported cases has exceeded 207 million globally,with more than 4.3 million deaths.COVID-19 has brought devastating losses...Coronavirus disease 2019(COVID-19)remains a global epidemic.As of August 18,2021,the number of reported cases has exceeded 207 million globally,with more than 4.3 million deaths.COVID-19 has brought devastating losses to human society.The overall crude mortality rate is 1-3%.Although pediatric deaths from COVID-19 are rare,they do occur,as over 9,000 children have died from COVID-19 globally to date[1].With the gradual and broad application of COVID-19 vaccines around the world,the rising proportion of cases among children and unvaccinated young adults demands attention.According to World Health Organization surveillance data.展开更多
The World Health Organization(WHO)announced COVID-19 as a global pandemic in March of 2020[1].The COVID-19 pandemic may persist for a long period of time.Global prevention and control becomes a complex and challenging...The World Health Organization(WHO)announced COVID-19 as a global pandemic in March of 2020[1].The COVID-19 pandemic may persist for a long period of time.Global prevention and control becomes a complex and challenging task,and such efforts should be sustained.Although general measures,such as social distancing,face masks,respiratory hygiene and hand sanitization,will bear fruits for decreasing spread of other respiratory illnesses including influenza,the specific prevention through vaccination is a key focus especially in the upcoming winter and spring seasons[2].展开更多
基金supported by the National Natural Science Foundation of China,No.81201513 (to QG)。
文摘Extremely low frequency electromagnetic fields(ELF-EMF) can improve the learning and memory impairment of rats with Alzheimer's disease, however, its effect on cerebral ischemia remains poorly understood.In this study, we established rat models of middle cerebral artery occlusion/reperfusion.One day after modeling, a group of rats were treated with ELF-EMF(50 Hz, 1 mT) for 2 hours daily on 28 successive days.Our results showed that rats treated with ELF-EMF required shorter swimming distances and latencies in the Morris water maze test than those of untreated rats.The number of times the platform was crossed and the time spent in the target quadrant were greater than those of untreated rats.The number of BrdU~+/NeuN~+ cells, representing newly born neurons, in the hippocampal subgranular zone increased more in the treated than in untreated rats.Up-regulation in the expressions of Notch1, Hes1, and Hes5 proteins, which are the key factors of the Notch signaling pathway, was greatest in the treated rats.These findings suggest that ELF-EMF can enhance hippocampal neurogenesis of rats with cerebral ischemia, possibly by affecting the Notch signaling pathway.The study was approved by the Institutional Ethics Committee of Sichuan University, China(approval No.2019255A) on March 5, 2019.
基金supported by the Natural Science Foundation for Youths of Tibet Autonomous Region of China (Grant No. XZ-20080383)
文摘This study is based on meteorological observation data collected at 38 weather stations on the Tibetan Plateau over several decades. Daily reference crop evapotranspiration （ETo） was calculated with the FAO-56 standard Penman-Monteith formula. A test of normality was performed with Statistica 6.0 software, isotropic and anisotropic semi-variogram analysis was conducted with the GS＋ （geostatistics for the environmental sciences） system for Windows 7.0, and the characteristics of spatial variation of daily ETo were obtained. The following results can be obtained Daily ETo for different periods on the Tibetan Plateau are distributed normally; Except for daily ETo in the E-W （east-west） direction in the summer, which showed a slight negative correlation with distance change, the Moran＇s indexes of daily ETo for different periods in all directions on the Tibetan Plateau within a 100-km distance were positive, demonstrating a positive correlation with distance change; Variograms of daily ETo in June, the dry season, the wet season, as well as annual average daily ETo fit well with the Gaussian model; A variogram of daily ETo in December fit well with the exponential model; Variograms of daily ETo for the four seasons fit well with the linear With sill model.
基金supported by the Science and Technology Project of Universities and Colleges in Shandong Province ‘‘Investigation on diagenetic environment and transformation pattern of red-bed reservoirs in the rift basins’’ (No. J16LH52)
文摘Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy mathematics is improved based on a previous study.First,the single-factor membership degree is determined using the dynamic clustering method,then a single-factor evaluation matrix is constructed using a continuous grading function,and finally,the probability distribution of the evaluation grade in a fuzzy evaluation matrix is analyzed.In this study,taking the F1 fault located in the northeastern Chepaizi Bulge as an example,the sealing properties of faults in different strata are quantitatively evaluated using both an improved and an un-improved comprehensive fuzzy mathematics quantitative evaluation method.Based on current oil and gas distribution,it is found that our evaluation results before and after improvement are significantly different.For faults in＂best＂and＂poorest＂intervals,our evaluation results are consistent with oil and gas distribution.However,for the faults in＂good＂or＂poor＂intervals,our evaluation is not completelyconsistent with oil and gas distribution.The improved evaluation results reflect the overall and local sealing properties of target zones and embody the nonuniformity of fault sealing,indicating the improved method is more suitable for evaluating fault sealing under complicated conditions.
文摘A novel methacrylate monomer with bulky side group, tri(2-pyridyl)methyl methacrylate (Tr2PyMA), was synthesized and polymerized. The polymer obtained by radical polymerization exhibits high isotactic tacticity.
文摘Method development for determination of isoflavones in kudzu was achieved by HPLC/UV/ESI-MSD. Us- ing three kudzu species of Pueraria lobata, P. thomsonii and P. edulis, and analyzing the isoflavones sepa- rately by species and from different plant tissues (roots, stems, leaves, flowers and fruits) in each species, a total of 25 isoflavones were identified by their molecular ions and characteristic fragment ion peaks using LC/MSD under MS and MS/MS mode, and in comparison with standard isoflavones. Two main chemical groups were identified: 1) 8-C-glycosyl isoflavone of puerarin and the analogues of 5-OH puerarin, 3’-OH puerarin, 3’-OMe puerarin, and their glycosides;and 2) daidzein, genistein, glycitein and their glycosyl and malonyl derivatives, which are similar to those known in soy. To accurately quantitate total isoflavones, acidic hydrolysis during extraction of kudzu samples was applied to convert the oxygen glycosides into their respective isoflavone aglycones of daidzein, genistein and glycitein, or non-hydrolyzed carbon glycosides of puerarin, 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin. Under the multiple optimized conditions, all seven isoflavones in acidic hydrolyzed kudzu extracts were successfully separated within 30 min and quanti- fied individually with calycosin used as internal standard by both UV and MS detectors. For the quantitative study, several standards e.g. 5-OH puerarin, 3’-OH puerarin and 3’-OMe puerarin are not commercially available. Using polyamide, sephdex-LH20 chromatography and Prep-HPLC, we purified these three stan- dards from kudzu extracts and then elucidated their structures by UV, MS and NMR spectrometric methods. This is the first method to simultaneously quantitate all the isoflavones in kudzu.
基金supported by grants from the National Natural Science Foundation of China (30872198 30972566)
文摘Obejective The domainⅢof dengue virus type 2 envelope was cloned and expressed in Escherichia coli and the inhibited effects of recombinant protein on virus was detected. Methods In this study, the domainⅢ(DⅢ) protein of the dengue virus type-2 (DENV-2) envelope (E) antigen was expressed in Escherichia coli by fusion with a carrier protein. The protein was puriifed using enzymatic cleavage and afifnity puriifcation. Rabbit immunization and antibody detection was carried out. Inhibition of DENV-2 infection was observed by DENV-2 EDⅢprotein and its immunity rabbits serum. Results The recombinant expression DENV-2 EDⅢ protein plasmid was constructed successfully. After isopropyl thiogalactoside induction, a speciifc soluble 29 kD protein was obtained, and the expression product accounted for 68.87%of the total protein of the cell lysate. Western blot demonstrated the reactivity of the recombinant protein with his-tag and DENV (Ⅰ-Ⅳ) monoclonal antibodies. The protein was puriifed using enzymatic cleavage and affinity purification. The purified recombinant EDⅢ protein inhibited the entry of DENV-2 into BHK-21 cells. DENV-2 plaque neutralization assays were carried out using serially diluted antibodies against EDⅢprotein. At a 1︰16 dilution, the antibodies produced at least 90%neutralization of the DENV-2 virus. Furthermore, the antibodies continued to exhibit high neutralization effects (approximately 80%) until the anti-EDⅢantibody titer reached 1︰1 024. Conclusions DENV-2 EDⅢwas cloned and expressed successfully. DENV-2 EDⅢprotein could be useful in the development of inexpensive dengue vaccine. The data also suggested that DENV-2 employed an attachment molecule or receptor for its entry into C6/36 mosquito cells.
基金National Natural Science Foundation of China(72174138)High-level Public health Talents Training Program of Beijing Municipal Health Commission(2022-2-002).
文摘It has been more than 3 years since the novel coronavirus(SARS-CoV-2)pandemic raged globally.The coronavirus disease 2019(COVID-19)has greatly influenced human society.According to data from the World Health Organization(WHO),there were over 656 million confirmed cases of COVID-19 in the world as of January 1,2023,including over 6.6 million deaths[1].
基金financially supported by the National Natural Science Foundation of China(Nos.U1537212,51471019 and 51271011)the National Key Research and Development Program of China(No.2016YFB0300901)。
文摘2A97 Al-Li alloy was cold-rolled to 2 mm and then thermally exposed at different temperatures for 1 h and at 723 K for different time,respectively.The texture evolution behavior and the anisotropy of 2A97 Al-Li alloy were investigated.The result shows that the{001}<120>and{011}<233>textures are the dominant recrystallization texture.The{124}<211>texture is the final recrystallization texture.In case of low-temperature thermal exposure(473,573 K),the{011}<211>texture is aggregated to the{112}<111>and{123}<634>textures.During the recrystallization at 723 K,the{001}<110>,{111}<112>and{011}<100>textures are the intermediate transition grain orientations.The concurrent precipitation of Al_(20)Cu_(2)Mn_(3)and Al_(3)Zr results in the occurrence of unusually sharp{011}<233>and{001}<120>texture components during recrystallization.The alloy with both recrystallization and deformation texture possesses the smallest anisotropic,and the texture is the direct reason that results in the anisotropy.
基金National Natural Science Foundation of China(72174138)High-level Public health Talents Training Program of Beijing Municipal Health Commission(2022-2-002).
文摘Monkeypox is a zoonotic disease.Since the first human monkeypox case was detected in 1970,it has been prevalent in some countries in central and western Africa.Since May 2022,monkeypox cases have been reported in more than 96 non-endemic countries and regions worldwide.As of September 14,2022,there have been more than 58,200 human monkeypox cases,and there is community transmission.The cessation of smallpox vaccination in 1980,which had some cross-protection with monkeypox,resulted in a general lack of immunity to monkeypox,which caused global concern and vigilance.As of Sep-tember 14,2022,there are four monkeypox cases in China,including three in Taiwan province and one in Hong Kong city.Previous foreign studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications.In order to improve pediatricians'understanding of monkeypox and achieve early detection,early diagno-sis,early treatment,and early disposal,we have organized national authoritative experts in pediatric infection,respiratory,dermatology,critical care medicine,infectious diseases,and public health and others to formulate this expert consensus,on the basis of the latest"Clinical management and infection prevention and control for monkeypox"released by The World Health Organization,the"guidelines for diagnosis and treatment of monkeypox(version 2022)"issued by National Health Commission of the People's Republic of China and other relevant documents.During the development of this consensus,multidisciplinary experts have repeatedly demonstrated the etiology,epidemiology,transmission,clinical manifestations,laboratory examinations,diagnosis,differential diagnosis,treatment,discharge criteria,prevention,disposal process,and key points of prevention and control of suspected and confirmed cases.
基金This research was funded by Sanming Project of Medicine in Shenzhen(SZSM201512030)The funding organization had no involvement in study design,collection of data,the writing of draft,and the decision to submit the article for publication.
文摘Background Increasing numbers of pertussis cases have been reported in recent years.The reported cases from Shenzhen Children's Hospital were close to one tenth of all cases in China.The epidemiology of antigenic genotype and antibiotic resistance of circulating strains in children have been unknown in Shenzhen,southern China.The aim of this study was to describe the clinical features and explore the genotypes and antimicrobial susceptibility of circulating Bordetella pertussis among children in Shenzhen.Methods Data of hospitalized children with pertussis in Shenzhen Children's Hospital from August 2015 to April 2017 were collected.The genetic variability of isolates was investigated and Etest was performed for phenotypic susceptibility to erythromycin,azithromycin,clarithromycin,clindamycin,and trimethoprim/sulfamethoxazole.Results 469 children with pertussis confirmed by real-time quantitative polymerase chain reaction were hospitalized and strains were isolated from 105 patients.White blood cell count≥20×10^9/L and lymphocyte proportion≥60%were observed in 39.29%of infants younger than 3 months.The two predominant profiles of virulence-associated allelic genes were ptxA1/ptxC1/ptxPl/prnl(48.6%)and ptxA1/ptxC2/ptxP3/prn2(44.8%).Among the isolates,48.6%(51/105)were found resistant to macrolides.Conclusions These findings indicate that leukocytosis is not a sensitive indicator of pertussis.Isolates with the gene profile ptxP3/prn2 were highly circulating in Shenzhen and less resistant to macrolides,different from patterns observed in other parts of China.
文摘In the early February,2020,we called up an experts' committee with more than 30 Chinese experts from 11 national medical academic organizations to formulate the first edition of consensus statement on diagnosis,treatment and prevention of coronavirus disease 2019 (COVID-19) in children,which has been published in this journal.With accumulated experiences in the diagnosis and treatment of COVID-19 in children,we have updated the consensus statement and released the second edition recently.The current version in English is a condensed version of the second edition of consensus statement on diagnosis,treatment and prevention of COVID-19 in children.In the current version,diagnosis and treatement criteria have been optimized,and early identification of severe and critical cases is highlighted.The early warning indicators for severe pediatric cases have been summarized which is utmost important for clinical practice.This version of experts consensus will be valuable for better prevention,diagnosis and treatment of COVID-19 in children worldwide.
文摘The viral pneumonia in Wuhan City,China has spread around China.The virus has been proven to be a novel coronavirus (named as "2019-nCoV") by World Health Organization (WHO).2019-nCoV belongs to beta-coronavirus genera.On January 30,2020,WHO re-evaluated the potential effects of 2019-nCoV infection in global public health,and declared this epidemic as a "Public Health Emergency of International Concern (PHEIC)".
文摘Background Children as a population have high antimicrobial prescribing rates which may lead to high resistance of bacteria according to data from some single-center surveys of antibiotic prescribing rates in China. The acquirement of baseline data of antibiotic prescribing is the basis of developing intervention strategies on inappropriate antimicrobial prescriptions. Few studies show clearly the pattern and detailed information on classes of antibiotics and distribution of indications of antibiotic prescriptions in children in China. This study aims to assess the antibiotic prescribing patterns among children and neonates hospitalized in 18 hospitals in China. Methods A 24-hour point prevalence survey on antimicrobial prescribing was conducted in hospitalized neonates and chil-dren in China from December 1st, 2016 to February 28th, 2017. Information on the antibiotic use of patients under 18 years of age who were administered one or more on-going antibiotics in the selected wards over a 24-hour period was collected. These data were submitted to the GARPEC (Global Antimicrobial Resistance, Prescribing and Efficacy in Children and Neonates) web-based application ( https ://pidrg -datab ase.sgul.ac.uk/redca p/ ). For statistical analysis, Microsoft Excel 2007 and SPSS 22.0 were used. Results The antibiotic data were collected in 35 wards in 18 hospitals from 9 provinces. In total, 67.76% (975/1439) of the patients (n = 1439) were given at least one antibiotic, including 58.1% (173/298) of neonates (n = 298) and 70.3% (802/1141) of children (n = 1141). In neonates, the three most frequently prescribed antibiotics were third-generation cephalosporins (41.7%), penicillins plus enzyme inhibitor (23.8%), and carbapenems (11.2%). In children, the three most frequently pre-scribed antibiotics were third-generation cephalosporins (35.5%), macrolides (23.2%), and penicillins plus enzyme inhibi-tors (15.9%). The most common indication for antibiotics was proven or probable bacterial lower respiratory tract infection (30.9% in neonates and 66.6% in children). Conclusions Antibiotics are commonly prescribed in the Chinese children population. It is likely that the third-generation cephalosporins and macrolides are currently overused in Chinese children. Efforts must be made to ensure safe and appropri-ate antibiotic prescribing to reduce and prevent the future development of antibiotic resistance.
基金supported by Children's Medicine Research Project of Beijing Children's Hospital,Capital Medical University(YZZD202002).
文摘Background The clinical use of gentamicin always lies in its antimicrobial activity in the past as an aminoglycoside antibiotic.However,in the past decade,there were considerable interests in therapeutic approaches in treating hereditary diseases.Some of the genodermatosis is caused by nonsense mutations that create premature termination codons and lead to the production of truncated or non-functional proteins.Gentamicin could induce readthrough of nonsense mutations and enable the synthesis of full-length proteins.We focus on previous publications on topical application of gentamicin and review its utility in genetic skin diseases.Data sources We search the MEDLINE through PubMed,EMBASE databases,and the Clinical Trials Registry Platform from January 1960 to July 2020 using the key search terms"gentamicin,topical gentamicin,genodermatosis,genetic skin diseases".Results The application of gentamicin in genodermatosis yielded promising results,both in vivo and in vitro,including Nagashima-type palmoplantar keratosis,epidermolysis bullosa,Hailey-Hailey disease,hereditary hypotrichosis simplex of the scalp,etc.Conclusions Topical gentamicin is a potential treatment option for genodermatosis caused by nonsense mutation.
文摘Antimicrobial resistance (AMR) has been declared a major threat to global health, with the potential to reverse advances in treating disease, and impeding other global pri-orities including human development. The urgent menace of AMR has been recognized by the World Health Organi-sation Global Action Plan in 2015 [1], the 2016 United Nations General Assembly unanimous commitment to tackle AMR [2], and the Association of Southeast Asian Nations (ASEAN) 2017 declaration on AMR (3)AMR has been highlighted as a major health and economic challenge, with the consequences of failing to meet that challenge falling upon our children and grandchildren. Not only will children bear the burden of rising AMR, they are especially at risk now due to a number of factors. In many studies, children and the elderly are the highest consumers of antimicrobi-als (4)In addition, frequently inappropriate doses in chil-dren mean that they are receiving sub-therapeutic doses, maximizing the chance of encouraging resistant organ-isms to flourish. The normal behaviour of early childhood also encourages the spread of resistant organisms between children. Finally, their lifetime risk of exposure to resistant organisms is higher than adults.
文摘Coronavirus disease 2019(COVID-19)is a public health disaster that has not been encountered for a hundred years.On January 12,2020,the World Health Organization(WHO)confirmed and named the coronavirus which caused unexplained pneumonia as 2019 novel coronavirus(2019-nCoV).Since then,the disease caused by this virus had been named as coronavirus disease 2019(COVID-19).On February 11,2020,the International Committee on Taxonomy of Viruses announced that the English name of the novel coronavirus was severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)[1].At present,SARS-CoV-2 infection is still rampant worldwide.As of September 10,2021,there were about 222 million confirmed cases of COVID-19 and more than 4.5 million deaths worldwide[2].According to the American Centers for Disease Control and Prevention,by July 29,2021,4.19 million pediatric COVID-19 cases had been reported in the United States。
文摘Coronavirus disease 2019(COVID-19)remains a global epidemic.As of August 18,2021,the number of reported cases has exceeded 207 million globally,with more than 4.3 million deaths.COVID-19 has brought devastating losses to human society.The overall crude mortality rate is 1-3%.Although pediatric deaths from COVID-19 are rare,they do occur,as over 9,000 children have died from COVID-19 globally to date[1].With the gradual and broad application of COVID-19 vaccines around the world,the rising proportion of cases among children and unvaccinated young adults demands attention.According to World Health Organization surveillance data.
文摘The World Health Organization(WHO)announced COVID-19 as a global pandemic in March of 2020[1].The COVID-19 pandemic may persist for a long period of time.Global prevention and control becomes a complex and challenging task,and such efforts should be sustained.Although general measures,such as social distancing,face masks,respiratory hygiene and hand sanitization,will bear fruits for decreasing spread of other respiratory illnesses including influenza,the specific prevention through vaccination is a key focus especially in the upcoming winter and spring seasons[2].
