Background: It has been conclusively established that intracranial aneurysms measuring a diameter below 7 mm pose a minimal risk of rupture. Conversely, those exhibiting irregular morphology or featuring the presence ...Background: It has been conclusively established that intracranial aneurysms measuring a diameter below 7 mm pose a minimal risk of rupture. Conversely, those exhibiting irregular morphology or featuring the presence of a sac necessitate a more stringent and rigorous management approach. Objective: The primary aim of this study is to delve into the morphological features of ruptured aneurysms situated in distinct regions of the brain. Furthermore, we endeavor to assess the degree of safety and efficacy associated with stent-assisted embolization as a treatment modality for these ruptured aneurysms. Methods: This retrospective study encompassed a cohort of 467 patients who presented with intracranial ruptured aneurysms and were diagnosed through a combination of computed tomography (CT) and digital subtraction angiography (DSA) at Nanfang Hospital of Southern Medical University, spanning from January 2009 to December 2019. The following clinical parameters were meticulously recorded: aneurysm height, width, neck measurements, immediate Raymond grade assessments, and any perioperative complications experienced. Results: Within the study population, the average dimensions of ruptured aneurysms were found to be 4.26 ± 2.10 mm (width), 4.86 ± 2.38 mm (height), and 4.04 ± 1.87 mm (neck). Categorically, the most prevalent types of aneurysms were 170 cases of anterior communicating artery aneurysms (accounting for 36.4%), followed by 161 cases of posterior communicating artery aneurysms (34.5%), 56 cases of middle cerebral artery aneurysms (12.0%), 13 cases of anterior cerebral artery aneurysms (2.8%), 45 cases of paraclinoid aneurysms (9.6%), 6 cases of superior pituitary artery aneurysms (1.3%), 7 cases of anterior choroidal artery aneurysms (1.5%), and 9 cases of vertebrobasilar artery aneurysms (2.0%). Notably, 18 patients (3.9%) presented with ruptured aneurysms coexisting with ascus. Regarding treatment approaches, 228 cases (48.8%) underwent stent-assisted embolization, 234 cases (50.1%) received coils embolization, and 5 cases (1.1%) were treated with the dual-catheter technique. Immediately post-treatment, 422 patients (90.4%) attained a Raymond Class I status, with a procedure-related complication rate of 0.9%. Importantly, no statistically significant differences were observed in the incidence of perioperative complications across the three distinct treatment groups (P = 0.505). Conclusion: The outcomes of this study affirm the safety and efficacy of stent-assisted embolization as a treatment modality for ruptured aneurysms.展开更多
Objective:To compare the antiplatelet effect and major adverse cerebrovascular events of Pipeline for intracranial aneurysms using glycoproteinⅡb/Ⅲa antagonists(GPI)eptifibatide and tirofiban.Methods:Retrospective a...Objective:To compare the antiplatelet effect and major adverse cerebrovascular events of Pipeline for intracranial aneurysms using glycoproteinⅡb/Ⅲa antagonists(GPI)eptifibatide and tirofiban.Methods:Retrospective analysis of relevant data of patients using GPIs combined with oral antiplatelet therapy in Nanfang Hospital of Southern Medical University from December 2017 to December 2019.The study was approved by the ethics Committee of Nanfang Hospital of Southern Medical University.According to the random use of GPIs drugs,they were assigned to the eptifibatide group and tirofiban group.Basic data,platelet inhibition rates at baseline,24 h and 72 h after administration,short-term major adverse cerebrovascular events,and bleeding complications were compared between the two groups.Results:A total of 47 patients were included in this study,including 24 patients in eptifibatide group and 23 patients in tirofiban group.There was no significant difference in average age(53.75 vs.53.91 years)and body mass index(BMI)(24.39 vs.22.73 kg/m2)between eptifibatide group and tirofiban group.There was no significant difference in coagulation factor function(R),fibrinogen function(K),fibrinolysis function(EPL),comprehensive coagulation index(Cl),arachidonic acid pathway inhibition rate(AA%)and adenosine diphosphate inhibition rate(ADP%).However,the baseline level of residual platelet function MA(ADP)in eptifibatide group was significantly higher than that in tirofiban group(50.79 vs.35.29 mm,P=0.0026).There was a statistical difference in the platelet aggregation function MA(65.38 vs.62.54 mm,p=0.0442),the rate of spontaneous hemorrhagic stroke(4.3%vs.0%)and the rate of asymptomatic minor bleeding(26.08%vs.4.1%)in the two groups(P<0.05).Conclusion:Both eptifibatide and tirofiban can effectively inhibit platelets,but the effect of etifeptide is better than that of tirofiban in preventing intracranial microhemorrhage and asymptomatic cerebral infarction.展开更多
Experimental investigations of electrokinetic phenomena of modified polytetrafluoroethylene membranes in the oily sewage from oil field were performed by using the streaming potential method. The zeta potentials of th...Experimental investigations of electrokinetic phenomena of modified polytetrafluoroethylene membranes in the oily sewage from oil field were performed by using the streaming potential method. The zeta potentials of the membranes in the oily waste water are estimated on the basis of Helmholtz—Smoluchowski equation. The experiment and calculation results show that the membranes are charged negatively, whose zeta poten-tials maintain at around -20mV. And the aperture of membranes, the temperature and the filtration flux have little influence on the streaming potentials and the zeta potentials of the membranes.Also the suspended particulates in the oily sewage are charged negatively. The membranes have strong ability to withhold the suspended substance and powerful antipollution competence because of the role of the charges on the mem-branes.展开更多
Background:Genotypes VI and VII of(APMV-1)have different host range and pathogenicity in pigeons and chickens.However,the molecular determinants of these differences are still unclear.Methods:Here,we aligned the DNA s...Background:Genotypes VI and VII of(APMV-1)have different host range and pathogenicity in pigeons and chickens.However,the molecular determinants of these differences are still unclear.Methods:Here,we aligned the DNA sequences of 56 genotype VI and 33 genotype VII APMV-1 strains.Sequence alignment results revealed that there are 17 amino acids sites differed between APMV-1 strains of these two genotypes.We then constructed a plasmid based on the full-length genome of rSG10 APMV-1 strain,which belongs to genotype VII but was mutated with these 17 VI-genotype-specific amino acids,and rescued as rSG10-17 strain.The restriction digestion and ligation and overlapping PCR methods were used in the construction of plasmids with amino acids mutation.This virus was evaluated for its virulence and growth characteristics.Results and conclusion:The results indicated that the virulence and the growth characteristics have no obvious difference between the rSG10-17 virus and its parental strain rSG10.The simultaneous mutation of 17 genotype-specific amino acids did not affect the virulence of APMV-1 in chickens.Further analysis of these amino acids is required by taking into consideration of the functions of encoded proteins.展开更多
The Newcastle disease virus(NDV)negative-strand RNA genome contains six genes.These genes encode nucleoprotein(NP),phosphoprotein(P),matrix protein(M),fusion protein(F),hemagglutinin-neuraminidase(HN),and RNA-dependen...The Newcastle disease virus(NDV)negative-strand RNA genome contains six genes.These genes encode nucleoprotein(NP),phosphoprotein(P),matrix protein(M),fusion protein(F),hemagglutinin-neuraminidase(HN),and RNA-dependent RNA polymerase(L)proteins.The six proteins affect the virulence of NDV in different ways,but available information on the six proteins is disparate and scattered across many databases and sources.A comprehensive overview of the proteins determining NDV virulence is lacking.This review summarizes the virulence of NDV as a complex trait determined by these six different proteins.展开更多
COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection.It is currently unknown as to the correlation between the magnitude of neutralizing antibody(NAb)responses and the disease severity in...COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection.It is currently unknown as to the correlation between the magnitude of neutralizing antibody(NAb)responses and the disease severity in COVID-19 patients.In a cohort of 59 recovered patients with disease severity including severe,moderate,mild,and asymptomatic,we observed the positive correlation between serum neutralizing capacity and disease severity,in particular,the highest NAb capacity in sera from the patients with severe disease,while a lack of ability of asymptomatic patients to mount competent NAbs.Furthermore,the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-tomoderate symptoms.These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity,highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.展开更多
To improve the precision of deep fertilization of paddy fields,a six-row centralized pneumatic deep precision fertilization device for a rice transplanter was designed.This device included a spiral fertilizer distribu...To improve the precision of deep fertilization of paddy fields,a six-row centralized pneumatic deep precision fertilization device for a rice transplanter was designed.This device included a spiral fertilizer distribution system,centralized pneumatic fertilizer delivery system,an opener system,and a fertilization control system.The centralized airflow distribution method was used in the fertilizer delivery system to ensure that the airflow in each fertilizer pipe was evenly distributed.The rotational speeds of the power take-off(PTO)and fertilizer shaft were measured synchronously using photoelectric sensors and matched proportionately in real-time using PID closed-loop control algorithms to achieve precise fertilization rates at each working speed of the rice transplanter.There were two key considerations in the design of the control system to ensure precise fertilization.Firstly,a photoelectric sensor was used to measure the speed of the PTO;the high rotational speed of the PTO could provide a high signal frequency and improve the precision of the measurement of the transplanter’s working speed.Secondly,the fertilizer shaft speed measurement subprogram was set to sleep for a short period to reduce the vibration caused by the engine.During the tests of pneumatic fertilizer delivery system,single-factor tests on airflow distribution methods were conducted.The results showed that the coefficient of variation of the airflow speed for the centralized airflow distribution method was 1.67%,which was the least among the coefficients of the three distribution methods.In the bench tests,the rotational speeds of the fertilizer shaft were set at 10 r/min,20 r/min,30 r/min,and 40 r/min.The maximum coefficient of variation of the fertilization consistency in different rows was 1.49%at the rotational speed of 20 r/min.The maximum coefficient of variation of the fertilization stability was 2.86%at the rotational speed of 40 r/min,while the average fertilizer amount per lap for each distributor was 26.25 g/r.The results of the dynamic fertilization tests showed that the maximum relative error of the fertilizer distribution amount was 2.00%when the target fertilizer rates were 20,30,and 40 kg/667 m2.The results of the field tests showed that the average relative error of the fertilization amount was 3.53%,which satisfies the design standard.This research provides a reference for optimizing pneumatic fertilizer delivery systems and improving fertilization control systems and other pneumatic precision fertilizer application devices.展开更多
The adaptive immunity that protects patients from coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is not well characterized.In particular,the asymptomatic patie...The adaptive immunity that protects patients from coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is not well characterized.In particular,the asymptomatic patients have been found to induce weak and transient SARS-CoV-2 antibody responses,but the underlying mechanisms remain unknown;meanwhile,the protective immunity that guide the recovery of these asymptomatic patients is elusive.Here,we characterized SARS-CoV-2-specific B-cell and T-cell responses in 10 asymptomatic patients and 64 patients with other disease severity(mild,n=10,moderate,n=32,severe,n=12)and found that asymptomatic or mild symptomatic patients failed to mount virus-specific germinal center(GC)B cell responses that result in robust and prolonged humoral immunity,assessed by GC response indicators including follicular helper T(TFH)cell and memory B cell responses as well as serum CXCL13 levels.Alternatively,these patients mounted potent virus-specific TH1 and CD8+T cell responses.In sharp contrast,patients of moderate or severe disease induced vigorous virus-specific GC B cell responses and associated TFH responses;however,the virus-specific TH1 and CD8+T cells were minimally induced in these patients.These results,therefore,uncovered the protective immunity in asymptomatic patients and also revealed the strikingly dichotomous and incomplete humoral and cellular immune responses in COVID-19 patients with different disease severity,providing important insights into rational design of effective COVID-19 vaccines.展开更多
The aim of this study is to evaluate the comfort and optimize the position parameters of steering wheel.Taking the H point of driver as the reference point,three position parameters of steering wheel were determined,w...The aim of this study is to evaluate the comfort and optimize the position parameters of steering wheel.Taking the H point of driver as the reference point,three position parameters of steering wheel were determined,which were used as experimental factors.A comprehensive evaluation index system of the comfort was established.The comfort range and optimal levels of three parameters were determined by a single factor test,based on which a response surface optimization and validation test was carried out.The optimization and validation test results show that the expected comprehensive score of the comfort is 0.864,and the average relative error between the predicted and the measured value is 4.18%,indicating that the optimization results are reliable.The findings can provide reference for the comfort optimization design of steering wheel in agricultural devices.展开更多
Several studies highlighted that the surface shape modifications which are inspired by the soil-burrowing animals have positively impacted the soil-tool adhesion;however,it is still unclear what the optimum dimensions...Several studies highlighted that the surface shape modifications which are inspired by the soil-burrowing animals have positively impacted the soil-tool adhesion;however,it is still unclear what the optimum dimensions of the domed surface are for minimizing soil-tool adhesion.In this study,twenty-seven domed discs were created according to Taguchi orthogonal array L27(3^(3))to determine the optimum dimensions of the domed surface that minimize normal adhesion force and disc sinkage simultaneously,as well as comparing the effect of the optimized domed disc versus the flat disc on the normal adhesion force under different soil conditions.The results revealed that disc coverage ratio and dome height to diameter ratio are essential to design parameters that influence the normal adhesion force of discs.According to the signal-to-noise ratio analysis,it was observed that the combination of 60%disc coverage ratio,25%dome height to diameter ratio,and 10 mm dome base diameter was found to be the most appropriate for the well-balanced improvement of both normal adhesion force and disc sinkage simultaneously.In all treatments,the optimized domed disc produced less normal adhesion force than the flat disc(about 7%-18%,according to soil condition).It can be concluded that properly designed domed surfaces can significantly reduce the normal adhesion force when compared to flat surfaces.展开更多
Steering wheel is the most frequently used manual device in tractors,whose position directly affects the handling comfort of the driver and fatigue degree of the arm muscles.In this study,the biomechanical modelling s...Steering wheel is the most frequently used manual device in tractors,whose position directly affects the handling comfort of the driver and fatigue degree of the arm muscles.In this study,the biomechanical modelling software AnyBody was used for an inverse kinetics analysis of the rotation process of tractor steering wheel,calculate the muscle activation degree of the driver’s arm and compare it with the calculated results of surface EMG tests to verify the reliability of the biomechanical model.Based on the biomechanical model,the effects of three position parameters(steering wheel inclination,front-back distance,and upper-lower height)on the activation degree of the driver’s arm muscles were evaluated.The results demonstrated that steering wheel inclination has the most significant effect on the degree of muscle activation,followed by the upper-lower height and then front-back distance.Considering the interaction among factors,a regression orthogonal test was designed,and the test results revealed that the minimum muscle activation(1.2887)can be obtained with the steering wheel inclination of 31°,front-back distance of 431 mm and upper-lower height of 375 mm.The findings can provide a reference for optimizing the structure and position parameters of tractor steering wheels.展开更多
Suicidal drug overdose is a major public health issue.In the United States,every year more than 33,000 people commit suicides.Our study focused on the characteristics of suicide victims in the state of Maryland.Materi...Suicidal drug overdose is a major public health issue.In the United States,every year more than 33,000 people commit suicides.Our study focused on the characteristics of suicide victims in the state of Maryland.Material and methods:This study was a retrospective review of autopsy cases of all suicide deaths caused by drug(s)or drug(s)with alcohol intoxication investigated by the OCME in Maryland over a 7-year period from January 2004 to December 2011.All deaths investigated by the OCME that require autopsy examination are subject to comprehensive toxicology testing for drugs and alcohol.The screen tests were performed using gas chromatography(GC)and radioimmunoassay techniques.All detected drugs and/or metabolites were confirmed using GC-mass spectrometry(GC-MS).Results:From 2004 to 2011,434 deaths were certified as suicide.Of the 434 suicidal overdose deaths,84%were white,11%were African-American,and about 5%were either Hispanic or Asian.The male and female ratio was almost equal.Their ages ranged 15-82 years.Of the 434 suicidal drug overdose deaths,277 victims(63.8%)consumed a single drug type and 157(36.2%)consumed more than one type of drug.Of the 277 single-drug overdose cases,71.1%suicides were due to prescription drugs,23.5%due to over-the-counter drugs,and 5.4%due to street/recreational drugs.Among single-type prescription drugs,analgesic(N=76),antidepressant(N=45),and neuroleptic(N=35)classes were the three leading type of drugs used in suicidal deaths.Oxycodone,morphine,quetiapine,and amitriptyline were the most common prescription drugs in suicidal overdose.Diphenhydramine was the leading over-the-counter drug.Of the 157 victims who consumed more than one drug,combined prescription drugs were present in 54.1%,mixed prescription and overthe-counter drugs in 29.3%,and prescription drugs/over-the-counter drugs and street drugs in 16.6%of cases.Of the multiple-drug overdose suicides,66.2%cases involved antidepressants.Discussion:Suicide is found in every age,racial,and ethnic group.In the USA,poisoning is thethird-leading method of suicide,following firearm injuries and hanging/strangulation.Our study indicates that prescription drugs,such as those in the opioid analgesic,neuroleptic,and antidepressant class(e.g.,oxycodone,morphine,quetiapine,amitriptyline,doxepin,and citalopram),are of special concern in the context of suicidal overdose deaths in the state of Maryland.Therefore,addressing the problems of intentional drug overdose in our society is worthy of public attention.展开更多
In the past 10 years,medical malpractice litigations have become a serious public health and social issues in China.This study aims to evaluate the medical malpractice litigations in Beijing.A retrospective study was ...In the past 10 years,medical malpractice litigations have become a serious public health and social issues in China.This study aims to evaluate the medical malpractice litigations in Beijing.A retrospective study was conducted using the database from the Key Laboratory of Evidence Science(KLES)at China University of Political Science and Law(CUPL)to demonstrate the extent and characteristics of the alleged medical malpractice cases and the conclusions of forensic evaluation from 2002 to 2011 in Beijing.A total of 1515 alleged medical malpractice cases were investigated by forensic medical experts at KLES‑CUPL during the study period.Of the 1515 cases,45.2%were male patients and 54.8%were female patients.The age of the patients ranged from newborn to 90 years,with average age of 44 years.The alleged medical malpractice cases involved 11.3%of newborns.From 2002 to 2006,the average number of medical malpractice litigations was 123 cases per year,while from 2007 to 2011,the average number of medical malpractice litigations was 180 per year,a 46%increase.Of the 1515 cases,588(38.8%)litigations were due to the patients’death.Clinical departments involved in claims most often were obstetrics(18.9%),followed by orthopedics(15.1%)and general surgery(11.5%).Medical error was found in 945(62.4%)cases.Of the 945 confirmed medical malpractice cases,the top medical misadventures were diagnostic errors(36.5%),improper performance of procedures(36.4%),and medication error(12.6%).Although tertiary hospitals were more likely to be sued than the secondary and primary hospitals(63.6%vs.36.4%),there was no significant difference between tertiary and secondary hospitals in the percentage of confirmed malpractice cases(62.3%vs.59.4%).The primary hospitals had the highest confirmed malpractice cases(73.2%).展开更多
Potent neutralizing antibodies(nAbs)against SARS-CoV-2 are a promising therapeutic against the ongoing COVID-19 pandemic.However,the continuous emergence of neutralizing antibody escape variants makes it challenging f...Potent neutralizing antibodies(nAbs)against SARS-CoV-2 are a promising therapeutic against the ongoing COVID-19 pandemic.However,the continuous emergence of neutralizing antibody escape variants makes it challenging for antibody therapeutics based on monospecific nAbs.Here,we generated an IgG-like bispecific antibody(bsAb),Bi-Nab,based on a pair of human neutralizing antibodies targeting multiple and invariant sites of the spike receptor binding domain(RBD):35B5 and 32C7.We demonstrated that Bi-Nab exhibited higher binding affinity to the Delta spike protein than its parental antibodies and presented an extended inhibition breadth of preventing RBD binding to angiotensin-converting enzyme 2(ACE2),the cellular receptor of SARS-CoV-2.In addition,pseudovirus neutralization results showed that Bi-Nab improved the neutralization potency and breadth with a lower half maximum inhibitory concentration(IC50)against wild-type SARS-CoV-2,variants being monitored(VBMs)and variants of concern(VOCs).Notably,the IgG-like Bi-Nab enhanced the neutralizing activity against Omicron variants with potent capabilities for transmission and immune evasion in comparison with its parental monoclonal antibody(mAb)32C7 and a cocktail(with the lowest IC50 values of 31.6 ng/mL against the Omicron BA.1 and 399.2 ng/mL against the Omicron BA.2),showing evidence of synergistic neutralization potency of Bi-Nab against the Omicron variants.Thus,Bi-Nab represents a feasible and effective strategy against SARS-CoV-2 variants of concern.展开更多
文摘Background: It has been conclusively established that intracranial aneurysms measuring a diameter below 7 mm pose a minimal risk of rupture. Conversely, those exhibiting irregular morphology or featuring the presence of a sac necessitate a more stringent and rigorous management approach. Objective: The primary aim of this study is to delve into the morphological features of ruptured aneurysms situated in distinct regions of the brain. Furthermore, we endeavor to assess the degree of safety and efficacy associated with stent-assisted embolization as a treatment modality for these ruptured aneurysms. Methods: This retrospective study encompassed a cohort of 467 patients who presented with intracranial ruptured aneurysms and were diagnosed through a combination of computed tomography (CT) and digital subtraction angiography (DSA) at Nanfang Hospital of Southern Medical University, spanning from January 2009 to December 2019. The following clinical parameters were meticulously recorded: aneurysm height, width, neck measurements, immediate Raymond grade assessments, and any perioperative complications experienced. Results: Within the study population, the average dimensions of ruptured aneurysms were found to be 4.26 ± 2.10 mm (width), 4.86 ± 2.38 mm (height), and 4.04 ± 1.87 mm (neck). Categorically, the most prevalent types of aneurysms were 170 cases of anterior communicating artery aneurysms (accounting for 36.4%), followed by 161 cases of posterior communicating artery aneurysms (34.5%), 56 cases of middle cerebral artery aneurysms (12.0%), 13 cases of anterior cerebral artery aneurysms (2.8%), 45 cases of paraclinoid aneurysms (9.6%), 6 cases of superior pituitary artery aneurysms (1.3%), 7 cases of anterior choroidal artery aneurysms (1.5%), and 9 cases of vertebrobasilar artery aneurysms (2.0%). Notably, 18 patients (3.9%) presented with ruptured aneurysms coexisting with ascus. Regarding treatment approaches, 228 cases (48.8%) underwent stent-assisted embolization, 234 cases (50.1%) received coils embolization, and 5 cases (1.1%) were treated with the dual-catheter technique. Immediately post-treatment, 422 patients (90.4%) attained a Raymond Class I status, with a procedure-related complication rate of 0.9%. Importantly, no statistically significant differences were observed in the incidence of perioperative complications across the three distinct treatment groups (P = 0.505). Conclusion: The outcomes of this study affirm the safety and efficacy of stent-assisted embolization as a treatment modality for ruptured aneurysms.
文摘Objective:To compare the antiplatelet effect and major adverse cerebrovascular events of Pipeline for intracranial aneurysms using glycoproteinⅡb/Ⅲa antagonists(GPI)eptifibatide and tirofiban.Methods:Retrospective analysis of relevant data of patients using GPIs combined with oral antiplatelet therapy in Nanfang Hospital of Southern Medical University from December 2017 to December 2019.The study was approved by the ethics Committee of Nanfang Hospital of Southern Medical University.According to the random use of GPIs drugs,they were assigned to the eptifibatide group and tirofiban group.Basic data,platelet inhibition rates at baseline,24 h and 72 h after administration,short-term major adverse cerebrovascular events,and bleeding complications were compared between the two groups.Results:A total of 47 patients were included in this study,including 24 patients in eptifibatide group and 23 patients in tirofiban group.There was no significant difference in average age(53.75 vs.53.91 years)and body mass index(BMI)(24.39 vs.22.73 kg/m2)between eptifibatide group and tirofiban group.There was no significant difference in coagulation factor function(R),fibrinogen function(K),fibrinolysis function(EPL),comprehensive coagulation index(Cl),arachidonic acid pathway inhibition rate(AA%)and adenosine diphosphate inhibition rate(ADP%).However,the baseline level of residual platelet function MA(ADP)in eptifibatide group was significantly higher than that in tirofiban group(50.79 vs.35.29 mm,P=0.0026).There was a statistical difference in the platelet aggregation function MA(65.38 vs.62.54 mm,p=0.0442),the rate of spontaneous hemorrhagic stroke(4.3%vs.0%)and the rate of asymptomatic minor bleeding(26.08%vs.4.1%)in the two groups(P<0.05).Conclusion:Both eptifibatide and tirofiban can effectively inhibit platelets,but the effect of etifeptide is better than that of tirofiban in preventing intracranial microhemorrhage and asymptomatic cerebral infarction.
文摘Experimental investigations of electrokinetic phenomena of modified polytetrafluoroethylene membranes in the oily sewage from oil field were performed by using the streaming potential method. The zeta potentials of the membranes in the oily waste water are estimated on the basis of Helmholtz—Smoluchowski equation. The experiment and calculation results show that the membranes are charged negatively, whose zeta poten-tials maintain at around -20mV. And the aperture of membranes, the temperature and the filtration flux have little influence on the streaming potentials and the zeta potentials of the membranes.Also the suspended particulates in the oily sewage are charged negatively. The membranes have strong ability to withhold the suspended substance and powerful antipollution competence because of the role of the charges on the mem-branes.
基金This study was supported by the Beijing Agriculture Innovation Consortium of Poultry Research System(BAIC04-2019)We thank Ye Zhao,PhD,from China Agricultural University for editing a draft of this manuscript。
文摘Background:Genotypes VI and VII of(APMV-1)have different host range and pathogenicity in pigeons and chickens.However,the molecular determinants of these differences are still unclear.Methods:Here,we aligned the DNA sequences of 56 genotype VI and 33 genotype VII APMV-1 strains.Sequence alignment results revealed that there are 17 amino acids sites differed between APMV-1 strains of these two genotypes.We then constructed a plasmid based on the full-length genome of rSG10 APMV-1 strain,which belongs to genotype VII but was mutated with these 17 VI-genotype-specific amino acids,and rescued as rSG10-17 strain.The restriction digestion and ligation and overlapping PCR methods were used in the construction of plasmids with amino acids mutation.This virus was evaluated for its virulence and growth characteristics.Results and conclusion:The results indicated that the virulence and the growth characteristics have no obvious difference between the rSG10-17 virus and its parental strain rSG10.The simultaneous mutation of 17 genotype-specific amino acids did not affect the virulence of APMV-1 in chickens.Further analysis of these amino acids is required by taking into consideration of the functions of encoded proteins.
文摘The Newcastle disease virus(NDV)negative-strand RNA genome contains six genes.These genes encode nucleoprotein(NP),phosphoprotein(P),matrix protein(M),fusion protein(F),hemagglutinin-neuraminidase(HN),and RNA-dependent RNA polymerase(L)proteins.The six proteins affect the virulence of NDV in different ways,but available information on the six proteins is disparate and scattered across many databases and sources.A comprehensive overview of the proteins determining NDV virulence is lacking.This review summarizes the virulence of NDV as a complex trait determined by these six different proteins.
基金supported by grants from the National Science and Technology Major Project(No.2017ZX10202102-006-002 to L.Y.)the National Natural Science Fund for Distinguished Young Scholars(No.31825011 to L.Y.)the National Science and Technology Major Project(2016ZX09J16105-001-002 to L.Y.).
文摘COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection.It is currently unknown as to the correlation between the magnitude of neutralizing antibody(NAb)responses and the disease severity in COVID-19 patients.In a cohort of 59 recovered patients with disease severity including severe,moderate,mild,and asymptomatic,we observed the positive correlation between serum neutralizing capacity and disease severity,in particular,the highest NAb capacity in sera from the patients with severe disease,while a lack of ability of asymptomatic patients to mount competent NAbs.Furthermore,the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-tomoderate symptoms.These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity,highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.
基金This research was supported by the National Key Research and Development Project of China(2017YFD0301404-05)and the Fundamental Research Funds for the Central Universities(2662018PY038).
文摘To improve the precision of deep fertilization of paddy fields,a six-row centralized pneumatic deep precision fertilization device for a rice transplanter was designed.This device included a spiral fertilizer distribution system,centralized pneumatic fertilizer delivery system,an opener system,and a fertilization control system.The centralized airflow distribution method was used in the fertilizer delivery system to ensure that the airflow in each fertilizer pipe was evenly distributed.The rotational speeds of the power take-off(PTO)and fertilizer shaft were measured synchronously using photoelectric sensors and matched proportionately in real-time using PID closed-loop control algorithms to achieve precise fertilization rates at each working speed of the rice transplanter.There were two key considerations in the design of the control system to ensure precise fertilization.Firstly,a photoelectric sensor was used to measure the speed of the PTO;the high rotational speed of the PTO could provide a high signal frequency and improve the precision of the measurement of the transplanter’s working speed.Secondly,the fertilizer shaft speed measurement subprogram was set to sleep for a short period to reduce the vibration caused by the engine.During the tests of pneumatic fertilizer delivery system,single-factor tests on airflow distribution methods were conducted.The results showed that the coefficient of variation of the airflow speed for the centralized airflow distribution method was 1.67%,which was the least among the coefficients of the three distribution methods.In the bench tests,the rotational speeds of the fertilizer shaft were set at 10 r/min,20 r/min,30 r/min,and 40 r/min.The maximum coefficient of variation of the fertilization consistency in different rows was 1.49%at the rotational speed of 20 r/min.The maximum coefficient of variation of the fertilization stability was 2.86%at the rotational speed of 40 r/min,while the average fertilizer amount per lap for each distributor was 26.25 g/r.The results of the dynamic fertilization tests showed that the maximum relative error of the fertilizer distribution amount was 2.00%when the target fertilizer rates were 20,30,and 40 kg/667 m2.The results of the field tests showed that the average relative error of the fertilization amount was 3.53%,which satisfies the design standard.This research provides a reference for optimizing pneumatic fertilizer delivery systems and improving fertilization control systems and other pneumatic precision fertilizer application devices.
基金This work was supported by grants from the National Science and Technology Major Project(No.2017ZX10202102-006-002 to L.Y.)National Key Research Development Plan(No.2016YFA0502202 to L.Ye)+1 种基金the National Natural Science Fund for Distinguished Young Scholars(No.31825011 to L.Y.)the Chongqing Special Research Project for Novel Coronavirus Pneumonia Prevention and Control(No.cstc2020jscx-2 to L.Y.,No.cstc2020jscx-fyzx0074 to Y.C.,ocstc2020jscx-fyzx0135 to Y.C.).
文摘The adaptive immunity that protects patients from coronavirus disease 2019(COVID-19),caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),is not well characterized.In particular,the asymptomatic patients have been found to induce weak and transient SARS-CoV-2 antibody responses,but the underlying mechanisms remain unknown;meanwhile,the protective immunity that guide the recovery of these asymptomatic patients is elusive.Here,we characterized SARS-CoV-2-specific B-cell and T-cell responses in 10 asymptomatic patients and 64 patients with other disease severity(mild,n=10,moderate,n=32,severe,n=12)and found that asymptomatic or mild symptomatic patients failed to mount virus-specific germinal center(GC)B cell responses that result in robust and prolonged humoral immunity,assessed by GC response indicators including follicular helper T(TFH)cell and memory B cell responses as well as serum CXCL13 levels.Alternatively,these patients mounted potent virus-specific TH1 and CD8+T cell responses.In sharp contrast,patients of moderate or severe disease induced vigorous virus-specific GC B cell responses and associated TFH responses;however,the virus-specific TH1 and CD8+T cells were minimally induced in these patients.These results,therefore,uncovered the protective immunity in asymptomatic patients and also revealed the strikingly dichotomous and incomplete humoral and cellular immune responses in COVID-19 patients with different disease severity,providing important insights into rational design of effective COVID-19 vaccines.
基金This study was supported by the National Natural Science Foundation of China(51875230)the Fundamental Research Funds for the Central Universities(2662018PY038)the Program for the Outstanding Young and Middle-aged Science and Technology Innovation Team in the Higher Education Institutions of Hubei(T201934).
文摘The aim of this study is to evaluate the comfort and optimize the position parameters of steering wheel.Taking the H point of driver as the reference point,three position parameters of steering wheel were determined,which were used as experimental factors.A comprehensive evaluation index system of the comfort was established.The comfort range and optimal levels of three parameters were determined by a single factor test,based on which a response surface optimization and validation test was carried out.The optimization and validation test results show that the expected comprehensive score of the comfort is 0.864,and the average relative error between the predicted and the measured value is 4.18%,indicating that the optimization results are reliable.The findings can provide reference for the comfort optimization design of steering wheel in agricultural devices.
文摘Several studies highlighted that the surface shape modifications which are inspired by the soil-burrowing animals have positively impacted the soil-tool adhesion;however,it is still unclear what the optimum dimensions of the domed surface are for minimizing soil-tool adhesion.In this study,twenty-seven domed discs were created according to Taguchi orthogonal array L27(3^(3))to determine the optimum dimensions of the domed surface that minimize normal adhesion force and disc sinkage simultaneously,as well as comparing the effect of the optimized domed disc versus the flat disc on the normal adhesion force under different soil conditions.The results revealed that disc coverage ratio and dome height to diameter ratio are essential to design parameters that influence the normal adhesion force of discs.According to the signal-to-noise ratio analysis,it was observed that the combination of 60%disc coverage ratio,25%dome height to diameter ratio,and 10 mm dome base diameter was found to be the most appropriate for the well-balanced improvement of both normal adhesion force and disc sinkage simultaneously.In all treatments,the optimized domed disc produced less normal adhesion force than the flat disc(about 7%-18%,according to soil condition).It can be concluded that properly designed domed surfaces can significantly reduce the normal adhesion force when compared to flat surfaces.
基金supported by National Natural Science Foundation of China(Grant No.51875230,52175232).
文摘Steering wheel is the most frequently used manual device in tractors,whose position directly affects the handling comfort of the driver and fatigue degree of the arm muscles.In this study,the biomechanical modelling software AnyBody was used for an inverse kinetics analysis of the rotation process of tractor steering wheel,calculate the muscle activation degree of the driver’s arm and compare it with the calculated results of surface EMG tests to verify the reliability of the biomechanical model.Based on the biomechanical model,the effects of three position parameters(steering wheel inclination,front-back distance,and upper-lower height)on the activation degree of the driver’s arm muscles were evaluated.The results demonstrated that steering wheel inclination has the most significant effect on the degree of muscle activation,followed by the upper-lower height and then front-back distance.Considering the interaction among factors,a regression orthogonal test was designed,and the test results revealed that the minimum muscle activation(1.2887)can be obtained with the steering wheel inclination of 31°,front-back distance of 431 mm and upper-lower height of 375 mm.The findings can provide a reference for optimizing the structure and position parameters of tractor steering wheels.
基金supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry[(2013)1792]Training Programmers Foundation for the Beijing Talents(2013D002023000002).
文摘Suicidal drug overdose is a major public health issue.In the United States,every year more than 33,000 people commit suicides.Our study focused on the characteristics of suicide victims in the state of Maryland.Material and methods:This study was a retrospective review of autopsy cases of all suicide deaths caused by drug(s)or drug(s)with alcohol intoxication investigated by the OCME in Maryland over a 7-year period from January 2004 to December 2011.All deaths investigated by the OCME that require autopsy examination are subject to comprehensive toxicology testing for drugs and alcohol.The screen tests were performed using gas chromatography(GC)and radioimmunoassay techniques.All detected drugs and/or metabolites were confirmed using GC-mass spectrometry(GC-MS).Results:From 2004 to 2011,434 deaths were certified as suicide.Of the 434 suicidal overdose deaths,84%were white,11%were African-American,and about 5%were either Hispanic or Asian.The male and female ratio was almost equal.Their ages ranged 15-82 years.Of the 434 suicidal drug overdose deaths,277 victims(63.8%)consumed a single drug type and 157(36.2%)consumed more than one type of drug.Of the 277 single-drug overdose cases,71.1%suicides were due to prescription drugs,23.5%due to over-the-counter drugs,and 5.4%due to street/recreational drugs.Among single-type prescription drugs,analgesic(N=76),antidepressant(N=45),and neuroleptic(N=35)classes were the three leading type of drugs used in suicidal deaths.Oxycodone,morphine,quetiapine,and amitriptyline were the most common prescription drugs in suicidal overdose.Diphenhydramine was the leading over-the-counter drug.Of the 157 victims who consumed more than one drug,combined prescription drugs were present in 54.1%,mixed prescription and overthe-counter drugs in 29.3%,and prescription drugs/over-the-counter drugs and street drugs in 16.6%of cases.Of the multiple-drug overdose suicides,66.2%cases involved antidepressants.Discussion:Suicide is found in every age,racial,and ethnic group.In the USA,poisoning is thethird-leading method of suicide,following firearm injuries and hanging/strangulation.Our study indicates that prescription drugs,such as those in the opioid analgesic,neuroleptic,and antidepressant class(e.g.,oxycodone,morphine,quetiapine,amitriptyline,doxepin,and citalopram),are of special concern in the context of suicidal overdose deaths in the state of Maryland.Therefore,addressing the problems of intentional drug overdose in our society is worthy of public attention.
基金supported by the fund for Training Programmers Foundation for the Beijing Talents(2013D002023000002)Beijing Planning Project of Philosophy and Social Science(13FXC032)Project of Young teachers’academic innovation team by CUPL(2016CXTD05 and 2014CXTD04).
文摘In the past 10 years,medical malpractice litigations have become a serious public health and social issues in China.This study aims to evaluate the medical malpractice litigations in Beijing.A retrospective study was conducted using the database from the Key Laboratory of Evidence Science(KLES)at China University of Political Science and Law(CUPL)to demonstrate the extent and characteristics of the alleged medical malpractice cases and the conclusions of forensic evaluation from 2002 to 2011 in Beijing.A total of 1515 alleged medical malpractice cases were investigated by forensic medical experts at KLES‑CUPL during the study period.Of the 1515 cases,45.2%were male patients and 54.8%were female patients.The age of the patients ranged from newborn to 90 years,with average age of 44 years.The alleged medical malpractice cases involved 11.3%of newborns.From 2002 to 2006,the average number of medical malpractice litigations was 123 cases per year,while from 2007 to 2011,the average number of medical malpractice litigations was 180 per year,a 46%increase.Of the 1515 cases,588(38.8%)litigations were due to the patients’death.Clinical departments involved in claims most often were obstetrics(18.9%),followed by orthopedics(15.1%)and general surgery(11.5%).Medical error was found in 945(62.4%)cases.Of the 945 confirmed medical malpractice cases,the top medical misadventures were diagnostic errors(36.5%),improper performance of procedures(36.4%),and medication error(12.6%).Although tertiary hospitals were more likely to be sued than the secondary and primary hospitals(63.6%vs.36.4%),there was no significant difference between tertiary and secondary hospitals in the percentage of confirmed malpractice cases(62.3%vs.59.4%).The primary hospitals had the highest confirmed malpractice cases(73.2%).
基金supported by the National Natural Science Foundation of China(32192453)the Chinese Universities Scientific Funds(2022RC019 and 2022TC163)+1 种基金the China Agricultural University Graduate Independent Innovation Research Fund(2022TC163)the 2115 Talent Development Program of China Agricultural University.
文摘Potent neutralizing antibodies(nAbs)against SARS-CoV-2 are a promising therapeutic against the ongoing COVID-19 pandemic.However,the continuous emergence of neutralizing antibody escape variants makes it challenging for antibody therapeutics based on monospecific nAbs.Here,we generated an IgG-like bispecific antibody(bsAb),Bi-Nab,based on a pair of human neutralizing antibodies targeting multiple and invariant sites of the spike receptor binding domain(RBD):35B5 and 32C7.We demonstrated that Bi-Nab exhibited higher binding affinity to the Delta spike protein than its parental antibodies and presented an extended inhibition breadth of preventing RBD binding to angiotensin-converting enzyme 2(ACE2),the cellular receptor of SARS-CoV-2.In addition,pseudovirus neutralization results showed that Bi-Nab improved the neutralization potency and breadth with a lower half maximum inhibitory concentration(IC50)against wild-type SARS-CoV-2,variants being monitored(VBMs)and variants of concern(VOCs).Notably,the IgG-like Bi-Nab enhanced the neutralizing activity against Omicron variants with potent capabilities for transmission and immune evasion in comparison with its parental monoclonal antibody(mAb)32C7 and a cocktail(with the lowest IC50 values of 31.6 ng/mL against the Omicron BA.1 and 399.2 ng/mL against the Omicron BA.2),showing evidence of synergistic neutralization potency of Bi-Nab against the Omicron variants.Thus,Bi-Nab represents a feasible and effective strategy against SARS-CoV-2 variants of concern.