目的 构建钩端螺旋体外膜脂蛋白 L ip L41基因的重组原核表达质粒 ,为进一步制备以 L ip L41为目的基因的亚单位疫苗提供实验依据。方法 根据钩端螺旋体 L.kirscneri RM5 2株外膜脂蛋白 L ip L41基因序列设计引物 ,以赖型钩端螺旋体 0...目的 构建钩端螺旋体外膜脂蛋白 L ip L41基因的重组原核表达质粒 ,为进一步制备以 L ip L41为目的基因的亚单位疫苗提供实验依据。方法 根据钩端螺旋体 L.kirscneri RM5 2株外膜脂蛋白 L ip L41基因序列设计引物 ,以赖型钩端螺旋体 0 17株基因组 DNA为模板 ,进行 PCR扩增并 DNA测序 ,以质粒 p GEX1λT为载体 ,插入 L ip L41基因片段构建重组原核表达质粒 ,并检测 L ip L41的表达。结果 测序结果示所得片段为 L ip L41的编码序列 ,酶切及 PCR分析证实重组质粒构建成功 ,SDS- PAGE和 Western blotting分析重组质粒可高效表达蛋白质 L ip L41。结论 L ip L41基因的重组原核表达质粒构建成功 。展开更多
Subject to the homogeneous Neumann boundary condition, a ratio-dependent predator-prey reaction diffusion model is discussed. An improved result for the model is derived, that is, the unique positive constant steady s...Subject to the homogeneous Neumann boundary condition, a ratio-dependent predator-prey reaction diffusion model is discussed. An improved result for the model is derived, that is, the unique positive constant steady state is the global stability. This is done using the comparison principle and establishing iteration schemes involving positive solutions supremum and infimum. The result indicates that the two species will ultimately distribute homogeneously in space. In fact, the comparison argument and iteration technique to be used in this paper can be applied to some other models. This method deals with the not-existence of a non-constant positive steady state for some reaction diffusion systems, which is rather simple but sufficiently effective.展开更多
Small bowel tumors and Crohn's disease are common causes of small bowel obstruction.Early stage neoplasms can easily be mistaken for Crohn's disease.Therefore,thorough work-ups including imaging studies and en...Small bowel tumors and Crohn's disease are common causes of small bowel obstruction.Early stage neoplasms can easily be mistaken for Crohn's disease.Therefore,thorough work-ups including imaging studies and endoscopic evaluation with biopsies are critical for accurate diagnosis.Here we report a case of an otherwise healthy female with progressive onset of multiple,recurrent obstructive symptoms secondary to terminal ileal narrowing who was referred for management of steroid-dependent Crohn's disease.After thorough evaluation,the diagnosis was revised to myeloid granulocytic sarcoma involving the terminal ileum.In this case,a delay in diagnosis can be detrimental for prognosis,as myeloid granulocytic sarcoma is highly predictive of underlying acute myeloid leukemia and needs urgent referral for chemotherapy and/or resection.展开更多
In order to investigate the stress-dependent properties of hot-mix asphalt (HMA),a dynamic modulus test was conducted on a group of AC-20 specimens at various stress states and loading frequencies,respectively.A use...In order to investigate the stress-dependent properties of hot-mix asphalt (HMA),a dynamic modulus test was conducted on a group of AC-20 specimens at various stress states and loading frequencies,respectively.A user-defined material (UMAT )subroutine incorporating stress-dependent constitutive model was developed and finite element (FE)simulation was utilized to confirm the validity of the UMAT.A three-dimensional (3D )FE model for typical pavement structure was established,considering the HMA layer as a stress-dependent material and other layers as linear elastic materials.Periodic load was applied to the pavement model and the pavement responses were calculated,including dynamic modulus distributions,surface deflection,shear stress and tensile strain in the HMA layer,etc.Both test results and FE model predictions indicate that the dynamic modulus of asphalt concrete is sensitive to stress state and loading frequency.Using the nonlinear stress-dependent model results in greater predicted pavement responses compared with the linear elastic model.It is also found that the effects of stress-dependency on pavement responses become more significant as loading frequency decreases.展开更多
As it is well-known, the North Equatorial Current (NEC) bifurcates into the Kuroshio flowing northward and the equatorward Mindanao Current, which is well depicted by Munk's theory in 1950 in terms of its climatol...As it is well-known, the North Equatorial Current (NEC) bifurcates into the Kuroshio flowing northward and the equatorward Mindanao Current, which is well depicted by Munk's theory in 1950 in terms of its climatology. However, Munk's theory is unable to tell the NEC bifurcation variability with time. In the present paper, a time-dependent baroclinic model forced by wind, in which temporal and baroclinic terms are added to Munk's equation, is proposed to examine the seasonal variability of the NEC bifurcation latitude. An analytical solution is obtained, with which the seasonal variability can be well described: NEC bifurcation reaches its northernmost position in December and its southernmost position in June with a range of about 1° in latitude, consistent with previous results with observations. The present solution will degenerate to Munk's one in the case of steady and barotropic state.展开更多
To assess the role of hypertension and family history of hypertensio n in the development of nephropathy in patients with non insulin dependent dia betes mellitus (NIDDM).Methods. A retrospective analysis was done on ...To assess the role of hypertension and family history of hypertensio n in the development of nephropathy in patients with non insulin dependent dia betes mellitus (NIDDM).Methods. A retrospective analysis was done on 2 groups of NIDDM patients, one g roup without proteinuria (urine protein< 300mg/24h, n=106) and the other group w ith proteinuria (urine protein≥500mg/24h, n=106). The 2 groups were matched by age(≤±3yrs), sex, ethnic and resident place. Some information of these subject s including demographic; history of disease, family history of diseases, lifesty le and behavior style variables was obtained by questionnaire; some variables w ere measured, including systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), quantity of protein in 24h urine. Then condi tional logistic regression analysis was performed.Results. Some factors, including history of hypertension, longer duration of hy pertension, higher levels of the past highest SBP and DBP, were independently as sociated with the occurrence risk of diabetic nephropathy (DN). Their correspond ing odd ratios (OR) with 95% confidence intervals (CI) were 2.00(1.17~3.43), 1 .25(1.08~1.46), 1.38(1.15~1.66), and 1.33(1.09~1.62) respectively, but family history of hypertension was not significantly associated with the development o f DN. When the above mentioned relations were respectively adjusted by some pos sible confounding factors, they still existed.Conclusions. History of hypertension, longer duration of hypertension, higher l evels of the past highest SBP and DBP are independent risk factors for DN in Chi nese NIDDM patients.展开更多
Objective To investigate the cause of high cardiovascular lethality in patients with diabetics mellitus. Methods Sections from autopsied coronary arteries and myocardium of dead patients with non-insulin-dependent dia...Objective To investigate the cause of high cardiovascular lethality in patients with diabetics mellitus. Methods Sections from autopsied coronary arteries and myocardium of dead patients with non-insulin-dependent diabetics mellitus and 12 dead control subjects were used for histomorphometric studies. Results The coronary atherosclerotic lesion in diabetics patients was not different in severity fi'om those in controls. Nor was there difference in number ofmyofibers or diameters of myoeardic fibers and capillaries.But the capillary density and the ratio of capillary number to myocardic fiber number in diabetics group were significeantly reduced compared with control group(P〈0.0 l),and the capillary basement membrane in the former was significantly thicker than in the latter(P〈0.01).Conclision The decrease in number of capillaries and the thickening of basement membrane enhance myocardiac vulnerability to further ischemia and hypoxia,which may undelie high lethality of myocardiopathy in diabetic patients.展开更多
The dynamic ground subsidence due to underground mining is a complicated time-dependent and rate- dependent process. Based. on the theory of rock rheology and probability integral method, this study developed the supe...The dynamic ground subsidence due to underground mining is a complicated time-dependent and rate- dependent process. Based. on the theory of rock rheology and probability integral method, this study developed the superposltlOn model for the prediction and analysis of the ground dynamic subsidence in mining area of thick !oose layer. The model consists of two parts (the prediction of overlying bedrock and the prediction of thick loose layer). The overlying bedrock is regarded as visco-elastic beam, of which the dynamic subsidence is predicted by the Kelvin visco-elastic rheological model. The thick loose layer is regarded as random medium, and the ground dynamic subsidence, is predicted by the probability integral model. At last, the two prediction models are vertically stacked in the same coordinate system, and the bedrock dynamic subsidence is regarded as a variable mining thickness input into the prediction model of ground dynamic subsidence. The prediction results obtained were compared w^th actual movement and deformation data from Zhao I and Zhao II mine, central China. The agreement of the prediction results with the. field measurements.show that the superposition model (SM) is more satisfactory and the formulae obtained are more effective than the classical single probability Integral model(SPIM), and thus can be effectively used for predicting the ground dynamic subsidence in mining area of thick loose layer.展开更多
As the green and sustainable development of human society highly relies on renewable energy,it has been recognized that electrocatalysis is a key technology to this end.High efficient ways of carbon-neutralization(eCO...As the green and sustainable development of human society highly relies on renewable energy,it has been recognized that electrocatalysis is a key technology to this end.High efficient ways of carbon-neutralization(eCO_(2)RR),reverse artificial nitrogen cycle(RANC),and oxygen chemistry(OER and ORR)all can be driven by electrocatalysis.Advanced theoretical study is an important means to fundamentally understanding electrocatalytic reactions.Herein,we review a few significant issues in theoretical electrocatalysis.First,electrochemical barriers and potential effects are essential for a more accurate description of reaction mechanism and activity.Meanwhile,consideration of competitive reaction path is also one of the important aspects,as novel insights and anomalous volcano trend can be obtained.Finally,a microenvironment exerted by confined space can tune the capacitance of electrochemical interface and(electro)chemical potential of proton,resulting in a possibility to improve reaction activity,which opens a new avenue for design of catalyst.展开更多
Coal and ore underground mining generates subsidence and deformation of the land surface. Those defor- mations may cause damage to buildings and infrastructures. The environmental impact of subsidence will not be acce...Coal and ore underground mining generates subsidence and deformation of the land surface. Those defor- mations may cause damage to buildings and infrastructures. The environmental impact of subsidence will not be accepted in the future by the society in many countries. Especially acceptance of the ground deformations decreases every year there, where the mining regions are densely urbanized, the The only solution is to limit the subsidence or its impact on the infrastructure. The first is not rentable for the mining industry, the second depends on the precise subsidence prediction and good preventing management involved in the mining areas. The precision of the subsidence prediction depends strictly on the mathematical model of the deformation phenomenon and on the uncertainty of the input data. The subsidence prediction in the geological conditions of the raw materials used to be made on the basis of numerical modeling or the stochastic models. A modified solution of the stochastic model by Knothe will be presented in the paper. The author focuses on the precise description of the deposit shape and on the time dependent displacements of the rock mass. A two parameters' time function has been introduced in the algorithm.展开更多
Chaos theory is used to prove that erratic and chaotic fluctuations can indeed arise in completely deterministic models. Chaos theory reveals structure in aperiodic, dynamic systems. A number of non-linear business cy...Chaos theory is used to prove that erratic and chaotic fluctuations can indeed arise in completely deterministic models. Chaos theory reveals structure in aperiodic, dynamic systems. A number of non-linear business cycle models use chaos theory to explain complex motion of the economy. Chaotic systems exhibit a sensitive dependence on initial conditions: Seemingly insignificant changes in the initial conditions produce large differences in outcomes. The basic aim of this analysis is to provide a relatively simple chaotic real-exchange-rate growth model that is capable of generating stable equilibria, cycles, or chaos.展开更多
We propose a monomer birth-death model with random removals, in which an aggregate of size k can produce a new monomer at a time-dependent rate I(t)k or lose one monomer at a rate J(t)k, and with a probability P(...We propose a monomer birth-death model with random removals, in which an aggregate of size k can produce a new monomer at a time-dependent rate I(t)k or lose one monomer at a rate J(t)k, and with a probability P(t) an aggregate of any size is randomly removed. We then anedytically investigate the kinetic evolution of the model by means of the rate equation. The results show that the scaling behavior of the aggregate size distribution is dependent crucially on the net birth rate I(t) - J(t) as well as the birth rate I(t). The aggregate size distribution can approach a standard or modified scaling form in some cases, but it may take a scale-free form in other cases. Moreover, the species can survive finally only if either I(t) - J(t) ≥ P(t) or [J(t) + P(t) - I(t)]t ≈ 0 at t ≥ 1; otherwise, it will become extinct.展开更多
文摘目的 构建钩端螺旋体外膜脂蛋白 L ip L41基因的重组原核表达质粒 ,为进一步制备以 L ip L41为目的基因的亚单位疫苗提供实验依据。方法 根据钩端螺旋体 L.kirscneri RM5 2株外膜脂蛋白 L ip L41基因序列设计引物 ,以赖型钩端螺旋体 0 17株基因组 DNA为模板 ,进行 PCR扩增并 DNA测序 ,以质粒 p GEX1λT为载体 ,插入 L ip L41基因片段构建重组原核表达质粒 ,并检测 L ip L41的表达。结果 测序结果示所得片段为 L ip L41的编码序列 ,酶切及 PCR分析证实重组质粒构建成功 ,SDS- PAGE和 Western blotting分析重组质粒可高效表达蛋白质 L ip L41。结论 L ip L41基因的重组原核表达质粒构建成功 。
文摘Subject to the homogeneous Neumann boundary condition, a ratio-dependent predator-prey reaction diffusion model is discussed. An improved result for the model is derived, that is, the unique positive constant steady state is the global stability. This is done using the comparison principle and establishing iteration schemes involving positive solutions supremum and infimum. The result indicates that the two species will ultimately distribute homogeneously in space. In fact, the comparison argument and iteration technique to be used in this paper can be applied to some other models. This method deals with the not-existence of a non-constant positive steady state for some reaction diffusion systems, which is rather simple but sufficiently effective.
文摘Small bowel tumors and Crohn's disease are common causes of small bowel obstruction.Early stage neoplasms can easily be mistaken for Crohn's disease.Therefore,thorough work-ups including imaging studies and endoscopic evaluation with biopsies are critical for accurate diagnosis.Here we report a case of an otherwise healthy female with progressive onset of multiple,recurrent obstructive symptoms secondary to terminal ileal narrowing who was referred for management of steroid-dependent Crohn's disease.After thorough evaluation,the diagnosis was revised to myeloid granulocytic sarcoma involving the terminal ileum.In this case,a delay in diagnosis can be detrimental for prognosis,as myeloid granulocytic sarcoma is highly predictive of underlying acute myeloid leukemia and needs urgent referral for chemotherapy and/or resection.
基金Jiangsu Provincial Transportation Science and Technology Project(No.2011Y02-1-G1)
文摘In order to investigate the stress-dependent properties of hot-mix asphalt (HMA),a dynamic modulus test was conducted on a group of AC-20 specimens at various stress states and loading frequencies,respectively.A user-defined material (UMAT )subroutine incorporating stress-dependent constitutive model was developed and finite element (FE)simulation was utilized to confirm the validity of the UMAT.A three-dimensional (3D )FE model for typical pavement structure was established,considering the HMA layer as a stress-dependent material and other layers as linear elastic materials.Periodic load was applied to the pavement model and the pavement responses were calculated,including dynamic modulus distributions,surface deflection,shear stress and tensile strain in the HMA layer,etc.Both test results and FE model predictions indicate that the dynamic modulus of asphalt concrete is sensitive to stress state and loading frequency.Using the nonlinear stress-dependent model results in greater predicted pavement responses compared with the linear elastic model.It is also found that the effects of stress-dependency on pavement responses become more significant as loading frequency decreases.
基金Supported by the Major Program of the National Natural Science Foundation of China (Nos. 40890150, 40890151)the National Basic Research Program of China (973 Program) (No.2007-CB411802)
文摘As it is well-known, the North Equatorial Current (NEC) bifurcates into the Kuroshio flowing northward and the equatorward Mindanao Current, which is well depicted by Munk's theory in 1950 in terms of its climatology. However, Munk's theory is unable to tell the NEC bifurcation variability with time. In the present paper, a time-dependent baroclinic model forced by wind, in which temporal and baroclinic terms are added to Munk's equation, is proposed to examine the seasonal variability of the NEC bifurcation latitude. An analytical solution is obtained, with which the seasonal variability can be well described: NEC bifurcation reaches its northernmost position in December and its southernmost position in June with a range of about 1° in latitude, consistent with previous results with observations. The present solution will degenerate to Munk's one in the case of steady and barotropic state.
文摘To assess the role of hypertension and family history of hypertensio n in the development of nephropathy in patients with non insulin dependent dia betes mellitus (NIDDM).Methods. A retrospective analysis was done on 2 groups of NIDDM patients, one g roup without proteinuria (urine protein< 300mg/24h, n=106) and the other group w ith proteinuria (urine protein≥500mg/24h, n=106). The 2 groups were matched by age(≤±3yrs), sex, ethnic and resident place. Some information of these subject s including demographic; history of disease, family history of diseases, lifesty le and behavior style variables was obtained by questionnaire; some variables w ere measured, including systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG), quantity of protein in 24h urine. Then condi tional logistic regression analysis was performed.Results. Some factors, including history of hypertension, longer duration of hy pertension, higher levels of the past highest SBP and DBP, were independently as sociated with the occurrence risk of diabetic nephropathy (DN). Their correspond ing odd ratios (OR) with 95% confidence intervals (CI) were 2.00(1.17~3.43), 1 .25(1.08~1.46), 1.38(1.15~1.66), and 1.33(1.09~1.62) respectively, but family history of hypertension was not significantly associated with the development o f DN. When the above mentioned relations were respectively adjusted by some pos sible confounding factors, they still existed.Conclusions. History of hypertension, longer duration of hypertension, higher l evels of the past highest SBP and DBP are independent risk factors for DN in Chi nese NIDDM patients.
文摘Objective To investigate the cause of high cardiovascular lethality in patients with diabetics mellitus. Methods Sections from autopsied coronary arteries and myocardium of dead patients with non-insulin-dependent diabetics mellitus and 12 dead control subjects were used for histomorphometric studies. Results The coronary atherosclerotic lesion in diabetics patients was not different in severity fi'om those in controls. Nor was there difference in number ofmyofibers or diameters of myoeardic fibers and capillaries.But the capillary density and the ratio of capillary number to myocardic fiber number in diabetics group were significeantly reduced compared with control group(P〈0.0 l),and the capillary basement membrane in the former was significantly thicker than in the latter(P〈0.01).Conclision The decrease in number of capillaries and the thickening of basement membrane enhance myocardiac vulnerability to further ischemia and hypoxia,which may undelie high lethality of myocardiopathy in diabetic patients.
基金provided by the National Natural Science Foundation of China Youth Found of China (No.41102169)the doctoral foundation of Henan Polytechnic University of China (No. B2014-056)
文摘The dynamic ground subsidence due to underground mining is a complicated time-dependent and rate- dependent process. Based. on the theory of rock rheology and probability integral method, this study developed the superposltlOn model for the prediction and analysis of the ground dynamic subsidence in mining area of thick !oose layer. The model consists of two parts (the prediction of overlying bedrock and the prediction of thick loose layer). The overlying bedrock is regarded as visco-elastic beam, of which the dynamic subsidence is predicted by the Kelvin visco-elastic rheological model. The thick loose layer is regarded as random medium, and the ground dynamic subsidence, is predicted by the probability integral model. At last, the two prediction models are vertically stacked in the same coordinate system, and the bedrock dynamic subsidence is regarded as a variable mining thickness input into the prediction model of ground dynamic subsidence. The prediction results obtained were compared w^th actual movement and deformation data from Zhao I and Zhao II mine, central China. The agreement of the prediction results with the. field measurements.show that the superposition model (SM) is more satisfactory and the formulae obtained are more effective than the classical single probability Integral model(SPIM), and thus can be effectively used for predicting the ground dynamic subsidence in mining area of thick loose layer.
文摘As the green and sustainable development of human society highly relies on renewable energy,it has been recognized that electrocatalysis is a key technology to this end.High efficient ways of carbon-neutralization(eCO_(2)RR),reverse artificial nitrogen cycle(RANC),and oxygen chemistry(OER and ORR)all can be driven by electrocatalysis.Advanced theoretical study is an important means to fundamentally understanding electrocatalytic reactions.Herein,we review a few significant issues in theoretical electrocatalysis.First,electrochemical barriers and potential effects are essential for a more accurate description of reaction mechanism and activity.Meanwhile,consideration of competitive reaction path is also one of the important aspects,as novel insights and anomalous volcano trend can be obtained.Finally,a microenvironment exerted by confined space can tune the capacitance of electrochemical interface and(electro)chemical potential of proton,resulting in a possibility to improve reaction activity,which opens a new avenue for design of catalyst.
文摘Coal and ore underground mining generates subsidence and deformation of the land surface. Those defor- mations may cause damage to buildings and infrastructures. The environmental impact of subsidence will not be accepted in the future by the society in many countries. Especially acceptance of the ground deformations decreases every year there, where the mining regions are densely urbanized, the The only solution is to limit the subsidence or its impact on the infrastructure. The first is not rentable for the mining industry, the second depends on the precise subsidence prediction and good preventing management involved in the mining areas. The precision of the subsidence prediction depends strictly on the mathematical model of the deformation phenomenon and on the uncertainty of the input data. The subsidence prediction in the geological conditions of the raw materials used to be made on the basis of numerical modeling or the stochastic models. A modified solution of the stochastic model by Knothe will be presented in the paper. The author focuses on the precise description of the deposit shape and on the time dependent displacements of the rock mass. A two parameters' time function has been introduced in the algorithm.
文摘Chaos theory is used to prove that erratic and chaotic fluctuations can indeed arise in completely deterministic models. Chaos theory reveals structure in aperiodic, dynamic systems. A number of non-linear business cycle models use chaos theory to explain complex motion of the economy. Chaotic systems exhibit a sensitive dependence on initial conditions: Seemingly insignificant changes in the initial conditions produce large differences in outcomes. The basic aim of this analysis is to provide a relatively simple chaotic real-exchange-rate growth model that is capable of generating stable equilibria, cycles, or chaos.
基金supported by National Natural Science Foundation of China under Grant Nos. 10775104 and 10305009
文摘We propose a monomer birth-death model with random removals, in which an aggregate of size k can produce a new monomer at a time-dependent rate I(t)k or lose one monomer at a rate J(t)k, and with a probability P(t) an aggregate of any size is randomly removed. We then anedytically investigate the kinetic evolution of the model by means of the rate equation. The results show that the scaling behavior of the aggregate size distribution is dependent crucially on the net birth rate I(t) - J(t) as well as the birth rate I(t). The aggregate size distribution can approach a standard or modified scaling form in some cases, but it may take a scale-free form in other cases. Moreover, the species can survive finally only if either I(t) - J(t) ≥ P(t) or [J(t) + P(t) - I(t)]t ≈ 0 at t ≥ 1; otherwise, it will become extinct.