Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the preven...Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the prevention and control of LF.Methods Samples of cerebrospinal fluid(CSF),blood,urine,saliva,and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection.Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus.Results LASV was detected in the patient’s CSF,blood,and urine,while all samples from close contacts and the environment tested negative.The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone.The variability in the glycoprotein complex(GPC)among different strains ranged from 3.9%to 15.1%,higher than previously reported for the seven known lineages.Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes,increasing strain diversity and potentially impacting immune response.Conclusion The case was confirmed through nucleotide detection,with no evidence of secondary transmission or viral spread.The LASV strain identified belongs to lineage IV,with broader GPC variability than previously reported.Mutations in the immune-related sites of GPC may affect immune responses,necessitating heightened vigilance regarding the virus.展开更多
Toxoplasma gondii(T.gondii)is an obligate intracellular parasite with a wide range of hosts,including humans and many warm-blooded animals.The parasite exists in two interconvertible forms,namely tachyzoites and brady...Toxoplasma gondii(T.gondii)is an obligate intracellular parasite with a wide range of hosts,including humans and many warm-blooded animals.The parasite exists in two interconvertible forms,namely tachyzoites and bradyzoites in intermediate hosts that are responsible for acute and chronic infections respectively.Mature bradyzoites accumulate large amounts of amylopectin granules but their roles have not been fully characterized.In this study,the predicted key enzymes involved in amylopectin synthesis(UDP-sugar pyrophospharylase,USP)and degradation(alpha-glucan water dikinase,GWD)of ME49 strain were individually knocked out,and then bradyzoite-related phenotyping experiments in vitro and in vivo were performed to dissect their roles during parasite growth and development.Deletion of the usp or gwd gene in the type II strain ME49 reduced the replication rates of tachyzoites in vitro and parasite virulence in vivo,suggesting that amylopectin metabolism is important for optimal tachyzoite growth.Interestingly,the Δusp mutant grew slightly faster than the parental strain under stress conditions that induced bradyzoite transition,which was likely due to the decreased efficiency of bradyzoite formation of theΔusp mutant.Although theΔgwd mutant could convert to bradyzoite robustly in vitro,it was significantly impaired in establishing chronic infection in vivo.Both the Δusp and Δgwd mutants showed a dramatic reduction in the reactivation of chronic infection in an in vitro model.Together,these results suggest that USP and GWD,which are involved in amylopectin synthesis and degradation have important roles in tachyzoite growth,as well as in the formation and reactivation of bradyzoites in T.gondii.展开更多
Fruit spine density is an important commercial trait for cucumber(Cucumis sativus L.).Most North China-type cucumbers that are grown over large areas have a dense-spine phenotype,which directly affects the appearance ...Fruit spine density is an important commercial trait for cucumber(Cucumis sativus L.).Most North China-type cucumbers that are grown over large areas have a dense-spine phenotype,which directly affects the appearance quality,storage,and transportation of the fruits.Here,we isolated a novel few spines mutant(fs2)from the wild-type(WT)inbred line WD1,a North China-type cucumber with high density fruit spines,by an ethyl methanesulfonate(EMS)mutagenesis treatment.Genetic analysis revealed that the phenotype of fs2 is controlled by a single recessive nuclear gene.We fine-mapped the fs2 locus using F_(2) and BC_(1) populations(1,802 and 420 individuals,respectively),which showed that the candidate gene of FS2(Csa4G652850)encodes an ARID-HMG transcription factor containing an AT-rich interaction domain(ARID)and a high mobility group box domain(HMG).One SNP(C to T)and one InDel(a 40-bp deletion)in the coding region of FS2 result in amino acid variation and premature translation termination in the fs2 mutant,respectively.FS2 was found to be highly expressed in the apical buds and young ovaries.In addition,experiments suggest that FS2 participates in the regulation of fruit spine initiation by activating the expression of the Tril gene in cucumber.This work provides not only an important reference for understanding the molecular mechanisms of fruit spine development but also an important resource for fruit appearance quality breeding in cucumber.展开更多
The direct numerical simulation (DNS) is carried out for the incompressible viscous turbulent flows over an anisotropic porous wall. Effects of the anisotropic porous wall on turbulence modifications as well as on the...The direct numerical simulation (DNS) is carried out for the incompressible viscous turbulent flows over an anisotropic porous wall. Effects of the anisotropic porous wall on turbulence modifications as well as on the turbulent drag reduction are investigated. The simulation is carried out at a friction Reynolds number of 180, which is based on the averaged friction velocity at the interface between the porous medium and the clear fluid domain. The depth of the porous layer ranges from 0.9 to 54 viscous units. The permeability in the spanwise direction is set to be lower than the other directions in the present simulation. The maximum drag reduction obtained is about 15.3% which occurs for a depth of 9 viscous units. The increasing of drag is addressed when the depth of the porous layer is more than 25 wall units. The thinner porous layer restricts the spanwise extension of the streamwise vortices which suppresses the bursting events near the wall. However, for the thicker porous layer, the wall-normal fluctuations are enhanced due to the weakening of the wall-blocking effect which can trigger strong turbulent structures near the wall.展开更多
A retrospective, serial analysis of 181 triple negative breast cancer (TNBC) patients was undertaken at a regional cancer centre in Canada. The primary focus of the analysis was to investigate the effect of presenting...A retrospective, serial analysis of 181 triple negative breast cancer (TNBC) patients was undertaken at a regional cancer centre in Canada. The primary focus of the analysis was to investigate the effect of presenting stage in patients with TNBC on progression free and overall survival. We were able to demonstrate that patients presenting with an earlier stage breast cancer had a significantly superior progression free and overall survival when compared to more advanced stage. The adjusted multivariate cox-regression analyses for the overall and progression free survival suggest that the hazard of death was significantly lower for patients with stages I (HR = 0.09;95% CI 0.03 - 0.24) and II (HR = 0.29;95% CI 0.16 - 0.54) than for patients with stage III. The only other predictor of progression free survival besides stage, was receipt of radiotherapy (HR = 0.39;95% CI 0.22 - 0.69) in the adjusted cox regression analysis. Less than 2% of patients presented with stage IV disease. The small numbers presenting with stage IV disease may have impact on the development of clinical and translational trials. Certainly there may be stage migration if staging included more standardized or more sensitive investigations such as PET scans, and this might an important consideration in developing clinical trials. Twenty-five percent of patients presented with stage I disease. It is important for patients with TNBC presenting with earlier stages of disease that they are aware that they will have a better prognosis than their counterparts with more advanced disease. It is important that we are aware of this patient population, as their treatment recommendations are unclear and a source of a fair amount of controversy currently.展开更多
基金supported by Public Health Talent Training and Surport Plan(National Administration of Disease Prevention and Control)Research and application of new technology for rapid monitoring and tracing of emergent infectious diseases among entry-exit population(2024YFFK0056)Monitoring,Early warning and Response of Major Infectious Diseases(2022ZDZX0017).
文摘Objective This study reports the first imported case of Lassa fever(LF)in China.Laboratory detection and molecular epidemiological analysis of the Lassa virus(LASV)from this case offer valuable insights for the prevention and control of LF.Methods Samples of cerebrospinal fluid(CSF),blood,urine,saliva,and environmental materials were collected from the patient and their close contacts for LASV nucleotide detection.Whole-genome sequencing was performed on positive samples to analyze the genetic characteristics of the virus.Results LASV was detected in the patient’s CSF,blood,and urine,while all samples from close contacts and the environment tested negative.The virus belongs to the lineage IV strain and shares the highest homology with strains from Sierra Leone.The variability in the glycoprotein complex(GPC)among different strains ranged from 3.9%to 15.1%,higher than previously reported for the seven known lineages.Amino acid mutation analysis revealed multiple mutations within the GPC immunogenic epitopes,increasing strain diversity and potentially impacting immune response.Conclusion The case was confirmed through nucleotide detection,with no evidence of secondary transmission or viral spread.The LASV strain identified belongs to lineage IV,with broader GPC variability than previously reported.Mutations in the immune-related sites of GPC may affect immune responses,necessitating heightened vigilance regarding the virus.
基金supported by the Fundamental Research Funds for the Central Universities in China(Grant no.2662022DKPY003)the HZAU-AGIS Cooperation Fund(Grant no.SZYJY2022015).
文摘Toxoplasma gondii(T.gondii)is an obligate intracellular parasite with a wide range of hosts,including humans and many warm-blooded animals.The parasite exists in two interconvertible forms,namely tachyzoites and bradyzoites in intermediate hosts that are responsible for acute and chronic infections respectively.Mature bradyzoites accumulate large amounts of amylopectin granules but their roles have not been fully characterized.In this study,the predicted key enzymes involved in amylopectin synthesis(UDP-sugar pyrophospharylase,USP)and degradation(alpha-glucan water dikinase,GWD)of ME49 strain were individually knocked out,and then bradyzoite-related phenotyping experiments in vitro and in vivo were performed to dissect their roles during parasite growth and development.Deletion of the usp or gwd gene in the type II strain ME49 reduced the replication rates of tachyzoites in vitro and parasite virulence in vivo,suggesting that amylopectin metabolism is important for optimal tachyzoite growth.Interestingly,the Δusp mutant grew slightly faster than the parental strain under stress conditions that induced bradyzoite transition,which was likely due to the decreased efficiency of bradyzoite formation of theΔusp mutant.Although theΔgwd mutant could convert to bradyzoite robustly in vitro,it was significantly impaired in establishing chronic infection in vivo.Both the Δusp and Δgwd mutants showed a dramatic reduction in the reactivation of chronic infection in an in vitro model.Together,these results suggest that USP and GWD,which are involved in amylopectin synthesis and degradation have important roles in tachyzoite growth,as well as in the formation and reactivation of bradyzoites in T.gondii.
基金supported by the National Natural Science Foundation of China(31972425)the Shanghai Agriculture Applied Technology Development Program,China(2020-02-08-00-08-F0148)。
文摘Fruit spine density is an important commercial trait for cucumber(Cucumis sativus L.).Most North China-type cucumbers that are grown over large areas have a dense-spine phenotype,which directly affects the appearance quality,storage,and transportation of the fruits.Here,we isolated a novel few spines mutant(fs2)from the wild-type(WT)inbred line WD1,a North China-type cucumber with high density fruit spines,by an ethyl methanesulfonate(EMS)mutagenesis treatment.Genetic analysis revealed that the phenotype of fs2 is controlled by a single recessive nuclear gene.We fine-mapped the fs2 locus using F_(2) and BC_(1) populations(1,802 and 420 individuals,respectively),which showed that the candidate gene of FS2(Csa4G652850)encodes an ARID-HMG transcription factor containing an AT-rich interaction domain(ARID)and a high mobility group box domain(HMG).One SNP(C to T)and one InDel(a 40-bp deletion)in the coding region of FS2 result in amino acid variation and premature translation termination in the fs2 mutant,respectively.FS2 was found to be highly expressed in the apical buds and young ovaries.In addition,experiments suggest that FS2 participates in the regulation of fruit spine initiation by activating the expression of the Tril gene in cucumber.This work provides not only an important reference for understanding the molecular mechanisms of fruit spine development but also an important resource for fruit appearance quality breeding in cucumber.
基金Project supported by the National Natural Science Foundation of China(Nos.11572183,91852111,and 11825204)the Program of Shanghai Municipal Education Commission(No.2019-01-07-00-09-E00018)
文摘The direct numerical simulation (DNS) is carried out for the incompressible viscous turbulent flows over an anisotropic porous wall. Effects of the anisotropic porous wall on turbulence modifications as well as on the turbulent drag reduction are investigated. The simulation is carried out at a friction Reynolds number of 180, which is based on the averaged friction velocity at the interface between the porous medium and the clear fluid domain. The depth of the porous layer ranges from 0.9 to 54 viscous units. The permeability in the spanwise direction is set to be lower than the other directions in the present simulation. The maximum drag reduction obtained is about 15.3% which occurs for a depth of 9 viscous units. The increasing of drag is addressed when the depth of the porous layer is more than 25 wall units. The thinner porous layer restricts the spanwise extension of the streamwise vortices which suppresses the bursting events near the wall. However, for the thicker porous layer, the wall-normal fluctuations are enhanced due to the weakening of the wall-blocking effect which can trigger strong turbulent structures near the wall.
文摘A retrospective, serial analysis of 181 triple negative breast cancer (TNBC) patients was undertaken at a regional cancer centre in Canada. The primary focus of the analysis was to investigate the effect of presenting stage in patients with TNBC on progression free and overall survival. We were able to demonstrate that patients presenting with an earlier stage breast cancer had a significantly superior progression free and overall survival when compared to more advanced stage. The adjusted multivariate cox-regression analyses for the overall and progression free survival suggest that the hazard of death was significantly lower for patients with stages I (HR = 0.09;95% CI 0.03 - 0.24) and II (HR = 0.29;95% CI 0.16 - 0.54) than for patients with stage III. The only other predictor of progression free survival besides stage, was receipt of radiotherapy (HR = 0.39;95% CI 0.22 - 0.69) in the adjusted cox regression analysis. Less than 2% of patients presented with stage IV disease. The small numbers presenting with stage IV disease may have impact on the development of clinical and translational trials. Certainly there may be stage migration if staging included more standardized or more sensitive investigations such as PET scans, and this might an important consideration in developing clinical trials. Twenty-five percent of patients presented with stage I disease. It is important for patients with TNBC presenting with earlier stages of disease that they are aware that they will have a better prognosis than their counterparts with more advanced disease. It is important that we are aware of this patient population, as their treatment recommendations are unclear and a source of a fair amount of controversy currently.
