Combining theory and computation,we explore the Goos–H¨anchen(GH)effect for electrons in a single-layered semiconductor microstructure(SLSM)modulated by Dresselhaus spin–orbit coupling(SOC).GH displacement depe...Combining theory and computation,we explore the Goos–H¨anchen(GH)effect for electrons in a single-layered semiconductor microstructure(SLSM)modulated by Dresselhaus spin–orbit coupling(SOC).GH displacement depends on electron spins thanks to Dresselhaus SOC,therefore electron spins can be separated from the space domain and spinpolarized electrons in semiconductors can be realized.Both the magnitude and sign of the spin polarization ratio change with the electron energy,in-plane wave vector,strain engineering and semiconductor layer thickness.The spin polarization ratio approaches a maximum at resonance;however,no electron-spin polarization occurs in the SLSM for a zero in-plane wave vector.More importantly,the spin polarization ratio can be manipulated by strain engineering or semiconductor layer thickness,giving rise to a controllable spatial electron-spin splitter in the field of semiconductor spintronics.展开更多
This paper presents a geometric Gaussian Kaczmarz (GGK) method for solving the large-scaled consistent linear systems of equation. The GGK method improves the geometric probability randomized Kaczmarz method in <a ...This paper presents a geometric Gaussian Kaczmarz (GGK) method for solving the large-scaled consistent linear systems of equation. The GGK method improves the geometric probability randomized Kaczmarz method in <a href="#ref1">[1]</a> by introducing a new block set strategy and the iteration process. The GGK is proved to be of linear convergence. Several numerical examples show the efficiency and effectiveness of the GGK method.展开更多
目前数据中心网络(data center network,DCN)的负载均衡方法存在对大小流的调度缺乏全局实时检测等不足,部分大流会造成拥塞、负载不均衡和带宽碎片等问题.针对上述问题,提出了一种SDN网络流量负载均衡算法—DSA-D.首先,对流量进行分类...目前数据中心网络(data center network,DCN)的负载均衡方法存在对大小流的调度缺乏全局实时检测等不足,部分大流会造成拥塞、负载不均衡和带宽碎片等问题.针对上述问题,提出了一种SDN网络流量负载均衡算法—DSA-D.首先,对流量进行分类,为大流计算所有源至目的主机可达路径的最短跳数路径集;然后,根据LLDP和ECHO测量链路时延以求得时延最优路径集;最后,采用概率拟合算法分配路径,实现数据中心网络流量负载均衡.在相同场景下的实验结果表明,与ECMP、Hedera和DIFF算法相比,DSA-D算法具有更好的吞吐量、链路带宽利用率和平均往返时延.展开更多
During the storage and transportation of the mango fruit, the major source of disease is anthracnose, caused by the fungus Colletotrichum gloeosporioides. The objective of this study is to find an appropriate method t...During the storage and transportation of the mango fruit, the major source of disease is anthracnose, caused by the fungus Colletotrichum gloeosporioides. The objective of this study is to find an appropriate method that not only reduces mango decay but also maintains its postharvest quality. The effects of chemicals, the use of the yeast species Metschnikowia pulcherrima and their combination on storage quality, focusing on the enzyme activity related to disease of Tainong mangos was studied. By immersing the mangoes in M. pulcherrima suspension(1.0×10~8 cfu mL^(–1)), salicylic acid(SA) solution(50 mg L^(–1)) or calcium chloride(CaCl_2) solution(1.0 g L^(–1)), the lesion expansion and decay of the mango fruit caused by C. gloeosporioides could be significantly delayed. These treatments also delayed the changes in quality traits(a~* value, firmness, contents of total soluble solids(TSS) and vitamin C(Vc), while the activities of anti-disease enzymes such as polyphenol oxidase(PPO), phenylalanine ammonia lyase(PAL), chitinase(CHT) and β-1,3-glucanase(GUN) were enhanced as compared to the control treatment. Furthermore, the combination of SA solution, CaCl_2 solution and M. pulcherrima suspension presented an additive effect, increasing the efficacy in controlling the disease and maintaining the storage quality of mango fruits. Taken together, our data suggest that the integration of chemical treatments combined with M. pulcherrima could be an alternative to the use of fungicides in postharvest treatment of the mango fruit, specifically for improving storage quality as well as the control of the anthracnose.展开更多
Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibitio...Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibition ratio of COS on BGC823 cells,MKN45 cells and SGC7901 cells at 48 h after treatment and the proliferation-inhibition curve was drawn with the inhibition ratio of COS on three types of cells.The clonogenic assay was used to detect the cell viability of 0,1,2,4,6 and 8 Gy(6 dose grades) in RAY group and RAY+COS group after X-ray,and the cell survival curve was used to analyze the sensitization enhancement ratio of COS.Flow cytometry was employed to detect cell cycle and apoptosis rate in control group,RAY group and RAY+COS group after 48 h treatment.Results:COS inhibited the proliferation of three types of cells.The inhibition rate was positively correlated with the concentration of COS,and the susceptibility of MKN45 cells,SGC7901 cells and BGC823 cells to COS decreased in turn.The cell viability decreased gradually with the increasing radiation dose in RAY group and RAY+COS group(P<0.01).The cell viabilities of RAY+COS group were lower than those of RAY group at all the dose grades under X-ray exposure(P<0.01),and the sensitization enhancement ratios of COS on BGC823 cells,MKN45 cells and SGC7901 cells were 1.06,1.28 and 1.15 respectively.In controlled trials,apoptosis rate and percentage in the G_2/M phase of three types of cells in RAY+COS group were higher than those in control group and RAY group,and percentage in the S phase and the G_0/G_1 phase in RAY+COS group were lower than those in the other two groups(P<0.01).Conclusions:COS can inhibit the proliferation of three types of human gastric cancer cells and enhance the radiosensitivity by inducing apoptosis and G_2/M phase arrest.展开更多
It is necessary to understand the bacterial populations associated with rice so as to provide more information and natural resources for effective management of major diseases in rice. A survey on screening and identi...It is necessary to understand the bacterial populations associated with rice so as to provide more information and natural resources for effective management of major diseases in rice. A survey on screening and identification of gram-positive bacteria was conducted during 1998 2004. Seven hundred and fifty-six rice samples were collected from Zhejiang, Jiangsu, Fujian and Yunnan Provinces, China. Over 1000 bacterial isolates were isolated and tested for colony morphology, pathogenicity, and some characteristics of bacteriology including Gram staining, fluorescent pigment on Kings medium B and microscopic observation for endospore. Together with five standard reference strains, 74 representative gram-positive bacterial isolates were confirmed by Biolog and gas chromatographic analysis of fatty acid methyl esters. Five bacterial species of Bacillus and other three genera were identified and isolates from Bacillus sublitis and Bacillus megaterium, exhibited the most effective inhibition against the pathogens of sheath blight and bakanae disease of rice. A few isolates from Bacillus pumilus and Bacillus megaterium showed weak virulent on rice together with some virulent isolates, risk should be considered when isolates from these species were screened for biocontrol agents.展开更多
Toll-like receptors(TLRs)play pivotal roles in inflammation and provide important links between the immune and skeletal systems.Although the activation of TLRs may affect osteoclast differentiation and bone metabolism...Toll-like receptors(TLRs)play pivotal roles in inflammation and provide important links between the immune and skeletal systems.Although the activation of TLRs may affect osteoclast differentiation and bone metabolism,whether and how TLRs are required for normal bone remodeling remains to be fully explored.In the current study,we show for the first time that TLR9^(-/-)mice exhibit a low bone mass and low-grade systemic chronic inflammation,which is characterized by the expansion of CD4^(+)T cells and increased levels of inflammatory cytokines,including TNFα,RANKL,and IL1β.The increased levels of these cytokines significantly promote osteoclastogenesis and induce bone loss.Importantly,TLR9 deletion alters the gut microbiota,and this dysbiosis is the basis of the systemic inflammation and bone loss observed in TLR9^(-/-)mice.Furthermore,through single-cell RNA sequencing,we identified myeloid-biased hematopoiesis in the bone marrow of TLR9^(-/-)mice and determined that the increase in myelopoiesis,likely caused by the adaptation of hematopoietic stem cells to systemic inflammation,also contributes to inflammation-induced osteoclastogenesis and subsequent bone loss in TLR9^(-/-)mice.Thus,our study provides novel evidence that TLR9 signaling connects the gut microbiota,immune system,and bone and is critical in maintaining the homeostasis of inflammation,hematopoiesis,and bone metabolism under normal conditions.展开更多
Objective To explore the correlation of blood glucose variability with the outcome in patients with severe acute stroke.Methods This retrospective clinical study was performed on patients with severe acute stroke.Base...Objective To explore the correlation of blood glucose variability with the outcome in patients with severe acute stroke.Methods This retrospective clinical study was performed on patients with severe acute stroke.Based on the three months mRS score after discharge,they were divided into good outcome groups and poor outcome groups.The blood glucose on admission,mean blood glucose,blood glucose standard deviation,coefficient variation of blood glucose and other clinical data were compared between both groups.Multivariate logistic regression analysis was used to determine the independent predictors of poor outcome in patients with severe acute stroke.Results A total of 420 patients with severe acute stroke were included,207(49.3%)with good outcome groups,213(50.7%)with poor outcome groups.Multivariate logistic regression analysis showed that age,NIHSS score,GCS score,APACHEⅡscore,blood glucose standard deviation,coefficient of variation of blood glucose were independent predictors of poor outcome in patients with severe acute stroke on 3 months after discharge.Conclusion Blood glucose variability are the independent predictors of poor outcome of the three months after discharge in patients with severe acute stroke,the great range of glycemic excursion indicates poor outcome.展开更多
Strong interaction between natural dissolved organic matter (DOM) and Hg(Ⅱ) may influence the trans- port, conversion, toxicity and bio-validity of mercury in the environment. In this paper ultraviolet (UV) absorbanc...Strong interaction between natural dissolved organic matter (DOM) and Hg(Ⅱ) may influence the trans- port, conversion, toxicity and bio-validity of mercury in the environment. In this paper ultraviolet (UV) absorbance titration was employed for the first time for the determination of the conditional stability constants of Hg(Ⅱ) and (DOM). With increasing Hg(Ⅱ) concentrations, the UV absorbance of fulvic acid, humic acid, and DOM in river increases progressively. By linear and non-linear model fitting, the conditional stability constants (lgK) of Hg(Ⅱ) and DOM were worked out to be 3.54?4.93 and 3.64?4.85, respectively. The results are consistent with those acquired by the typical fluorescence quenching titration method, with the maximum relative error of lgK being 2.6% and the average relative error being 0.2%. The UV absorbance titration method has the advantages of rapid determination, simple performance, and it will probably become a new approach to studying interactions between DOM and trace metallic ions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.62164005).
文摘Combining theory and computation,we explore the Goos–H¨anchen(GH)effect for electrons in a single-layered semiconductor microstructure(SLSM)modulated by Dresselhaus spin–orbit coupling(SOC).GH displacement depends on electron spins thanks to Dresselhaus SOC,therefore electron spins can be separated from the space domain and spinpolarized electrons in semiconductors can be realized.Both the magnitude and sign of the spin polarization ratio change with the electron energy,in-plane wave vector,strain engineering and semiconductor layer thickness.The spin polarization ratio approaches a maximum at resonance;however,no electron-spin polarization occurs in the SLSM for a zero in-plane wave vector.More importantly,the spin polarization ratio can be manipulated by strain engineering or semiconductor layer thickness,giving rise to a controllable spatial electron-spin splitter in the field of semiconductor spintronics.
文摘This paper presents a geometric Gaussian Kaczmarz (GGK) method for solving the large-scaled consistent linear systems of equation. The GGK method improves the geometric probability randomized Kaczmarz method in <a href="#ref1">[1]</a> by introducing a new block set strategy and the iteration process. The GGK is proved to be of linear convergence. Several numerical examples show the efficiency and effectiveness of the GGK method.
文摘目前数据中心网络(data center network,DCN)的负载均衡方法存在对大小流的调度缺乏全局实时检测等不足,部分大流会造成拥塞、负载不均衡和带宽碎片等问题.针对上述问题,提出了一种SDN网络流量负载均衡算法—DSA-D.首先,对流量进行分类,为大流计算所有源至目的主机可达路径的最短跳数路径集;然后,根据LLDP和ECHO测量链路时延以求得时延最优路径集;最后,采用概率拟合算法分配路径,实现数据中心网络流量负载均衡.在相同场景下的实验结果表明,与ECMP、Hedera和DIFF算法相比,DSA-D算法具有更好的吞吐量、链路带宽利用率和平均往返时延.
基金supported by the National Natural Science Foundation of China(31660587 and 31660586)
文摘During the storage and transportation of the mango fruit, the major source of disease is anthracnose, caused by the fungus Colletotrichum gloeosporioides. The objective of this study is to find an appropriate method that not only reduces mango decay but also maintains its postharvest quality. The effects of chemicals, the use of the yeast species Metschnikowia pulcherrima and their combination on storage quality, focusing on the enzyme activity related to disease of Tainong mangos was studied. By immersing the mangoes in M. pulcherrima suspension(1.0×10~8 cfu mL^(–1)), salicylic acid(SA) solution(50 mg L^(–1)) or calcium chloride(CaCl_2) solution(1.0 g L^(–1)), the lesion expansion and decay of the mango fruit caused by C. gloeosporioides could be significantly delayed. These treatments also delayed the changes in quality traits(a~* value, firmness, contents of total soluble solids(TSS) and vitamin C(Vc), while the activities of anti-disease enzymes such as polyphenol oxidase(PPO), phenylalanine ammonia lyase(PAL), chitinase(CHT) and β-1,3-glucanase(GUN) were enhanced as compared to the control treatment. Furthermore, the combination of SA solution, CaCl_2 solution and M. pulcherrima suspension presented an additive effect, increasing the efficacy in controlling the disease and maintaining the storage quality of mango fruits. Taken together, our data suggest that the integration of chemical treatments combined with M. pulcherrima could be an alternative to the use of fungicides in postharvest treatment of the mango fruit, specifically for improving storage quality as well as the control of the anthracnose.
基金supported by Youth Science Fund Project(No.81400612)
文摘Objective:To observe the chitooligosaccharides(COS) effect on the proliferation inhibition and radiosensitivity of three types of human gastric cancer cell line.Mothods:CCK-8 assay was employed to obtain the inhibition ratio of COS on BGC823 cells,MKN45 cells and SGC7901 cells at 48 h after treatment and the proliferation-inhibition curve was drawn with the inhibition ratio of COS on three types of cells.The clonogenic assay was used to detect the cell viability of 0,1,2,4,6 and 8 Gy(6 dose grades) in RAY group and RAY+COS group after X-ray,and the cell survival curve was used to analyze the sensitization enhancement ratio of COS.Flow cytometry was employed to detect cell cycle and apoptosis rate in control group,RAY group and RAY+COS group after 48 h treatment.Results:COS inhibited the proliferation of three types of cells.The inhibition rate was positively correlated with the concentration of COS,and the susceptibility of MKN45 cells,SGC7901 cells and BGC823 cells to COS decreased in turn.The cell viability decreased gradually with the increasing radiation dose in RAY group and RAY+COS group(P<0.01).The cell viabilities of RAY+COS group were lower than those of RAY group at all the dose grades under X-ray exposure(P<0.01),and the sensitization enhancement ratios of COS on BGC823 cells,MKN45 cells and SGC7901 cells were 1.06,1.28 and 1.15 respectively.In controlled trials,apoptosis rate and percentage in the G_2/M phase of three types of cells in RAY+COS group were higher than those in control group and RAY group,and percentage in the S phase and the G_0/G_1 phase in RAY+COS group were lower than those in the other two groups(P<0.01).Conclusions:COS can inhibit the proliferation of three types of human gastric cancer cells and enhance the radiosensitivity by inducing apoptosis and G_2/M phase arrest.
基金the National Natural Science Foundation of China(30270891) National 863 Program(2002AA241261).
文摘It is necessary to understand the bacterial populations associated with rice so as to provide more information and natural resources for effective management of major diseases in rice. A survey on screening and identification of gram-positive bacteria was conducted during 1998 2004. Seven hundred and fifty-six rice samples were collected from Zhejiang, Jiangsu, Fujian and Yunnan Provinces, China. Over 1000 bacterial isolates were isolated and tested for colony morphology, pathogenicity, and some characteristics of bacteriology including Gram staining, fluorescent pigment on Kings medium B and microscopic observation for endospore. Together with five standard reference strains, 74 representative gram-positive bacterial isolates were confirmed by Biolog and gas chromatographic analysis of fatty acid methyl esters. Five bacterial species of Bacillus and other three genera were identified and isolates from Bacillus sublitis and Bacillus megaterium, exhibited the most effective inhibition against the pathogens of sheath blight and bakanae disease of rice. A few isolates from Bacillus pumilus and Bacillus megaterium showed weak virulent on rice together with some virulent isolates, risk should be considered when isolates from these species were screened for biocontrol agents.
基金supported by grants from the National Natural Science Foundation of China(nos.81820100820 and 81372845 to C.Z.,no.81400855 to C.Y.and no.82170893 to Q.T.)supported by National Key R&D Program of China grant no.2018YFC1106300(to C.Z.)+1 种基金Natural Science Foundation of Shanghai grant no.21ZR1448600(to C.Y.)Science and Technology Commission of Shanghai Municipality grant no.14pj1407200(to C.Y.)。
文摘Toll-like receptors(TLRs)play pivotal roles in inflammation and provide important links between the immune and skeletal systems.Although the activation of TLRs may affect osteoclast differentiation and bone metabolism,whether and how TLRs are required for normal bone remodeling remains to be fully explored.In the current study,we show for the first time that TLR9^(-/-)mice exhibit a low bone mass and low-grade systemic chronic inflammation,which is characterized by the expansion of CD4^(+)T cells and increased levels of inflammatory cytokines,including TNFα,RANKL,and IL1β.The increased levels of these cytokines significantly promote osteoclastogenesis and induce bone loss.Importantly,TLR9 deletion alters the gut microbiota,and this dysbiosis is the basis of the systemic inflammation and bone loss observed in TLR9^(-/-)mice.Furthermore,through single-cell RNA sequencing,we identified myeloid-biased hematopoiesis in the bone marrow of TLR9^(-/-)mice and determined that the increase in myelopoiesis,likely caused by the adaptation of hematopoietic stem cells to systemic inflammation,also contributes to inflammation-induced osteoclastogenesis and subsequent bone loss in TLR9^(-/-)mice.Thus,our study provides novel evidence that TLR9 signaling connects the gut microbiota,immune system,and bone and is critical in maintaining the homeostasis of inflammation,hematopoiesis,and bone metabolism under normal conditions.
文摘Objective To explore the correlation of blood glucose variability with the outcome in patients with severe acute stroke.Methods This retrospective clinical study was performed on patients with severe acute stroke.Based on the three months mRS score after discharge,they were divided into good outcome groups and poor outcome groups.The blood glucose on admission,mean blood glucose,blood glucose standard deviation,coefficient variation of blood glucose and other clinical data were compared between both groups.Multivariate logistic regression analysis was used to determine the independent predictors of poor outcome in patients with severe acute stroke.Results A total of 420 patients with severe acute stroke were included,207(49.3%)with good outcome groups,213(50.7%)with poor outcome groups.Multivariate logistic regression analysis showed that age,NIHSS score,GCS score,APACHEⅡscore,blood glucose standard deviation,coefficient of variation of blood glucose were independent predictors of poor outcome in patients with severe acute stroke on 3 months after discharge.Conclusion Blood glucose variability are the independent predictors of poor outcome of the three months after discharge in patients with severe acute stroke,the great range of glycemic excursion indicates poor outcome.
基金the National Natural Science Foundation of China（Grant Nos.40525011,40632011）；the International Cooperation Project of the Chinese Academy of Sciences.
文摘Strong interaction between natural dissolved organic matter (DOM) and Hg(Ⅱ) may influence the trans- port, conversion, toxicity and bio-validity of mercury in the environment. In this paper ultraviolet (UV) absorbance titration was employed for the first time for the determination of the conditional stability constants of Hg(Ⅱ) and (DOM). With increasing Hg(Ⅱ) concentrations, the UV absorbance of fulvic acid, humic acid, and DOM in river increases progressively. By linear and non-linear model fitting, the conditional stability constants (lgK) of Hg(Ⅱ) and DOM were worked out to be 3.54?4.93 and 3.64?4.85, respectively. The results are consistent with those acquired by the typical fluorescence quenching titration method, with the maximum relative error of lgK being 2.6% and the average relative error being 0.2%. The UV absorbance titration method has the advantages of rapid determination, simple performance, and it will probably become a new approach to studying interactions between DOM and trace metallic ions.
