The present study focuses on the mitigation of shock wave using novel geometric passages in the flow field.The strategy is to produce multiple shock reflections and diffractions in the passage with minimum flow obstru...The present study focuses on the mitigation of shock wave using novel geometric passages in the flow field.The strategy is to produce multiple shock reflections and diffractions in the passage with minimum flow obstruction,which in turn is expected to reduce the shock wave strength at the target location.In the present study the interaction of a plane shock front(generated from a shock tube)with various geometric designs such as,1)zig-zag geometric passage,2)staggered cylindrical obstructions and 3)zigzag passage with cylindrical obstructions have been investigated using computational technique.It is seen from the numerical simulation that,among the various designs,the maximum shock attenuation is produced by the zig-zag passage with cylindrical obstructions which is then followed by zig-zag passage and staggered cylindrical obstructions.A comprehensive investigation on the shock wave reflection and diffraction phenomena happening in the proposed complex passages have also been carried out.In the new zig-zag design,the initial shock wave undergoes shock wave reflection and diffraction process which swaps alternatively as the shock front moves from one turn to the other turn.This cyclic shock reflection and diffraction process helps in diffusing the shock wave energy with practically no obstruction to the flow field.It is found that by combining the shock attenuation ability of zig-zag passage(using shock reflection and diffraction)with the shock attenuation ability of cylindrical blocks(by flow obstruction),a drastic attenuation in shock strength can be achieved with moderate level of flow blocking.展开更多
Objective To observe the correlations of chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with blood eosinophil(EOS)level.Methods Chest CT data of 16...Objective To observe the correlations of chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with blood eosinophil(EOS)level.Methods Chest CT data of 162 AECOPD patients with elevated eosinophils were retrospectively analyzed.The patients were divided into low EOS group(n=105)and high EOS group(n=57)according to the absolute counting of blood EOS.The quantitative CT parameters,including the number of whole lung bronchi and the volume of blood vessels,low-attenuation area percentage(LAA%)of whole lung,of left/right lung and each lobe of lung,as well as the luminal diameter(LD),wall thickness(WT),wall area(WA)and WA percentage of total bronchial cross-section(WA%)of grade 3 to 8 bronchi were compared between groups.Spearman correlations were performed to analyze the correlations of quantitative CT parameters with blood EOS level.Results LAA%of the whole lung,of the left/right lung and each lobe of lung,as well as of the upper lobe of right lung LD grade 4,middle lobe of right lung WT grade 5,upper lobe of right lung WA grade 4,middle lobe of right lung WA grade 5 and lower lobe of left lung WA grade 3 in low EOS group were all higher than those in high EOS group(all P<0.05).Except for the upper lobe of right lung LD grade 4,the above quantitative CT indexes being significant different between groups were all weakly and negatively correlated with blood EOS level(r=-0.335 to-0.164,all P<0.05).Conclusion Chest CT quantitative parameters of AECOPD patients were correlated with blood EOS level,among which LAA%,a part of WT and WA were all weakly negatively correlated with blood EOS level.展开更多
The rigid-flexible coupling dynamic modeling and simulation of an inspection robot were conducted to study the influences of the flexible obstructive working environment i.e. overhead transmission line on the robot＇s...The rigid-flexible coupling dynamic modeling and simulation of an inspection robot were conducted to study the influences of the flexible obstructive working environment i.e. overhead transmission line on the robot＇s dynamic performance. First, considering the structure of the obstacles and symmetrical mechanism of the robot prototype, four basic subactions were abstracted to fulfill full-path kinematic tasks. Then, a multi-rigid-body dynamic model of the robot was built with Lagrange equation, whil^e a multi-flexible-body dynamic model of a span of lin~ was obtained by combining finite element method （FEM）, modal synthesis method and Lagrange equation. The two subsystem models were coupled under rolling along no-obstacle segment and overcoming obstacle poses, and these simulations of three subactions along different spans of line were performed in ADMAS. The simulation results, including the coupling vibration parameters and driving moment of joint motors, show the dynamic performances of the robot along ftexibile obstructive working path： in flexible obstructive working environment, the robot can fulfill the preset motion goals; it responses slower in more flexible path; the fluctuation of robot as well as driving moment of the corresponding joint in startup and brake region is greater than that in rigid environment; the fluctuation amplitude increases with increasing working environment flexibility.展开更多
Solar water heaters(SWH) are widely used in urban areas because of their advantages in reducing energy consumption and mitigating greenhouse gas emissions. However, the performance of SWH subjected to obstructions is ...Solar water heaters(SWH) are widely used in urban areas because of their advantages in reducing energy consumption and mitigating greenhouse gas emissions. However, the performance of SWH subjected to obstructions is unclear yet. In this study, we present a numerical evaluation on thermal performance of fa?ade-installed SWH under three typical obstructed scenarios, based on various levels of sunshine duration. This study is carried out for four locations with various latitudes across China. Thermal performance is measured by solar fraction for annual and monthly evaluation. The results show that the obstruction can seriously degrade annual solar fraction of SWH, even in the 4-hour sunshine duration scenario, for all the studied locations. Interestingly, only lengthening sunshine duration in the standard day(e.g., from 2 h to 4 h) may not result in increasing annual solar fraction markedly. In terms of the monthly performance, solar fraction in January and December decreases significantly, while from May to August it just declines slightly, except for Guangzhou having a swift reduction. This study can provide insights into the behavior and promote the appropriate application of SWH in urban areas.展开更多
Since 1934,when Hirschfelder first reported magnesium(Mg) deficiency syndrome in man, considerable clinicalworks related to hypomagnesemia have appeared in medicalliterature. Recently, it is considered that Mg is a ki...Since 1934,when Hirschfelder first reported magnesium(Mg) deficiency syndrome in man, considerable clinicalworks related to hypomagnesemia have appeared in medicalliterature. Recently, it is considered that Mg is a kind ofnatural antagonist of calcium (Ca). Mg has some effects onthe smooth muscles of the bronchial and pulmonary arteries,and to relax the spasm of them. Therefore, there may exista close relation between Mg and cor pulmonale caused bychronic obstructive pulmonay desease (COPD).展开更多
Objective To investigate the bacteria spectrum isolated from AE-CB/COPD and the manner of management of AE-CB/COPD in respiratory or internal medicine department in some regions of China. Methods Respiratory physician...Objective To investigate the bacteria spectrum isolated from AE-CB/COPD and the manner of management of AE-CB/COPD in respiratory or internal medicine department in some regions of China. Methods Respiratory physicians received questionnaire at randomization just after they managed a patient presenting to outpatient department with AE-CB/COPD, on general conditions and symptoms of patients, type of examinations, diagnosis, type of antibiotics used and mode of administration. Results of sputum bacteria culture were followed up. Results Among the 1583 AE-CB/COPD, 63.04% were male and 35.19% were female. 54.6% of them were older than 60 years. 81.87% of the patients produced sputum. Sputum bacteria culture, chest X-ray and chest CT were carried out to 21.3%, 66.3% and 11.1% patients, respectively. 355 strains were isolated from patients whose sputum bacteria culture was positive. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were the three most isolates. 84.7% of the 1583 AE-CB/COPD received 1692 times of antibiotic prescribing. The most frequently prescribed antibiotic were B-lactams (51.36% of all antibiotic prescribing), macrolides (14.01%) and quinolones (31.03%). Much more macrolides were prescribed in the area where more patients pay the medicines at his own expense than those in the area where more patients share public health service. Conclusion In China, respiratory physicians can reasonably select antibiotics to manage acute exacerbation of chronic bronchitis/ chronic obstructive pulmonary disease in pulmonary outpatient department. Sputum culture is done in part of the patients, but susceptibility tests are missing. One issue revealed by the survey is that the list of prescribing medications laid down by government have great influence on antibiotic use.展开更多
The present study was designed to determine the relationship between changes of plasma endothelin 1 concentrations and development of colonic obstruction in sleep.Colons were bound in three sheep with sterilized plas...The present study was designed to determine the relationship between changes of plasma endothelin 1 concentrations and development of colonic obstruction in sleep.Colons were bound in three sheep with sterilized plastic tubes to make pathological model of colonic obstruction.Samples were collected before and after modeling operation on both controls and models.Endothelin 1 concentrations were measured by radioimmunoassay.Plasma ET llevels decreased continually after the modeling operation in the models,it dropped from a basal value of 60 93±18 66 to 34 11±8 22 and 33 54±11 12 pg/mL(P<0 05) on the 3rd and 5 th day,respectively,which were also lower than controls 64 16±12 93 pg/mL(P<0 05).It suggests that colonic obstruction may induce a decrease in plasma endothelin 1 concentrations in sleep.展开更多
OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmo...OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.展开更多
肾间质纤维化是几乎每种类型的慢性肾病不可避免的后果,然而其潜在机制尚未完全清楚。Tian等在既往的研究中确定,表面活性蛋白A（surfactant protein A,SP-A）是参与单侧输尿管梗阻（unilateral ureter obstruction,UUO）诱导的肾纤维...肾间质纤维化是几乎每种类型的慢性肾病不可避免的后果,然而其潜在机制尚未完全清楚。Tian等在既往的研究中确定,表面活性蛋白A（surfactant protein A,SP-A）是参与单侧输尿管梗阻（unilateral ureter obstruction,UUO）诱导的肾纤维化的一种新的蛋白因子。UUO诱导小鼠肾上皮中SP-A表达,可能是由于增加的酸性应激和炎症。展开更多
文摘The present study focuses on the mitigation of shock wave using novel geometric passages in the flow field.The strategy is to produce multiple shock reflections and diffractions in the passage with minimum flow obstruction,which in turn is expected to reduce the shock wave strength at the target location.In the present study the interaction of a plane shock front(generated from a shock tube)with various geometric designs such as,1)zig-zag geometric passage,2)staggered cylindrical obstructions and 3)zigzag passage with cylindrical obstructions have been investigated using computational technique.It is seen from the numerical simulation that,among the various designs,the maximum shock attenuation is produced by the zig-zag passage with cylindrical obstructions which is then followed by zig-zag passage and staggered cylindrical obstructions.A comprehensive investigation on the shock wave reflection and diffraction phenomena happening in the proposed complex passages have also been carried out.In the new zig-zag design,the initial shock wave undergoes shock wave reflection and diffraction process which swaps alternatively as the shock front moves from one turn to the other turn.This cyclic shock reflection and diffraction process helps in diffusing the shock wave energy with practically no obstruction to the flow field.It is found that by combining the shock attenuation ability of zig-zag passage(using shock reflection and diffraction)with the shock attenuation ability of cylindrical blocks(by flow obstruction),a drastic attenuation in shock strength can be achieved with moderate level of flow blocking.
文摘Objective To observe the correlations of chest CT quantitative parameters in patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)with blood eosinophil(EOS)level.Methods Chest CT data of 162 AECOPD patients with elevated eosinophils were retrospectively analyzed.The patients were divided into low EOS group(n=105)and high EOS group(n=57)according to the absolute counting of blood EOS.The quantitative CT parameters,including the number of whole lung bronchi and the volume of blood vessels,low-attenuation area percentage(LAA%)of whole lung,of left/right lung and each lobe of lung,as well as the luminal diameter(LD),wall thickness(WT),wall area(WA)and WA percentage of total bronchial cross-section(WA%)of grade 3 to 8 bronchi were compared between groups.Spearman correlations were performed to analyze the correlations of quantitative CT parameters with blood EOS level.Results LAA%of the whole lung,of the left/right lung and each lobe of lung,as well as of the upper lobe of right lung LD grade 4,middle lobe of right lung WT grade 5,upper lobe of right lung WA grade 4,middle lobe of right lung WA grade 5 and lower lobe of left lung WA grade 3 in low EOS group were all higher than those in high EOS group(all P<0.05).Except for the upper lobe of right lung LD grade 4,the above quantitative CT indexes being significant different between groups were all weakly and negatively correlated with blood EOS level(r=-0.335 to-0.164,all P<0.05).Conclusion Chest CT quantitative parameters of AECOPD patients were correlated with blood EOS level,among which LAA%,a part of WT and WA were all weakly negatively correlated with blood EOS level.
基金Project(50575165) supported by the National Natural Science Foundation of ChinaProjects(2006AA04Z202, 2005AA2006-1) supported by the National High-Tech Research and Development Program of China+1 种基金Project(20813) supported by the Natural Science Foundation of Hubei Province, ChinaProject(20045006071-28) supported by the Youth Chenguang Project of Science and Technology of Wuhan City, China
文摘The rigid-flexible coupling dynamic modeling and simulation of an inspection robot were conducted to study the influences of the flexible obstructive working environment i.e. overhead transmission line on the robot＇s dynamic performance. First, considering the structure of the obstacles and symmetrical mechanism of the robot prototype, four basic subactions were abstracted to fulfill full-path kinematic tasks. Then, a multi-rigid-body dynamic model of the robot was built with Lagrange equation, whil^e a multi-flexible-body dynamic model of a span of lin~ was obtained by combining finite element method （FEM）, modal synthesis method and Lagrange equation. The two subsystem models were coupled under rolling along no-obstacle segment and overcoming obstacle poses, and these simulations of three subactions along different spans of line were performed in ADMAS. The simulation results, including the coupling vibration parameters and driving moment of joint motors, show the dynamic performances of the robot along ftexibile obstructive working path： in flexible obstructive working environment, the robot can fulfill the preset motion goals; it responses slower in more flexible path; the fluctuation of robot as well as driving moment of the corresponding joint in startup and brake region is greater than that in rigid environment; the fluctuation amplitude increases with increasing working environment flexibility.
基金Projects(2017JJ3517,2017JJ3090)supported by the Natural Science Foundation of Hunan Province,ChinaProject(2018NK2066)supported by the Key Research and Development Program of Hunan Province,ChinaProject(QJ2017007B)supported by the Youth Scientific Research Foundation of Central South University of Forestry and Technology,China。
文摘Solar water heaters(SWH) are widely used in urban areas because of their advantages in reducing energy consumption and mitigating greenhouse gas emissions. However, the performance of SWH subjected to obstructions is unclear yet. In this study, we present a numerical evaluation on thermal performance of fa?ade-installed SWH under three typical obstructed scenarios, based on various levels of sunshine duration. This study is carried out for four locations with various latitudes across China. Thermal performance is measured by solar fraction for annual and monthly evaluation. The results show that the obstruction can seriously degrade annual solar fraction of SWH, even in the 4-hour sunshine duration scenario, for all the studied locations. Interestingly, only lengthening sunshine duration in the standard day(e.g., from 2 h to 4 h) may not result in increasing annual solar fraction markedly. In terms of the monthly performance, solar fraction in January and December decreases significantly, while from May to August it just declines slightly, except for Guangzhou having a swift reduction. This study can provide insights into the behavior and promote the appropriate application of SWH in urban areas.
文摘Since 1934,when Hirschfelder first reported magnesium(Mg) deficiency syndrome in man, considerable clinicalworks related to hypomagnesemia have appeared in medicalliterature. Recently, it is considered that Mg is a kind ofnatural antagonist of calcium (Ca). Mg has some effects onthe smooth muscles of the bronchial and pulmonary arteries,and to relax the spasm of them. Therefore, there may exista close relation between Mg and cor pulmonale caused bychronic obstructive pulmonay desease (COPD).
文摘Objective To investigate the bacteria spectrum isolated from AE-CB/COPD and the manner of management of AE-CB/COPD in respiratory or internal medicine department in some regions of China. Methods Respiratory physicians received questionnaire at randomization just after they managed a patient presenting to outpatient department with AE-CB/COPD, on general conditions and symptoms of patients, type of examinations, diagnosis, type of antibiotics used and mode of administration. Results of sputum bacteria culture were followed up. Results Among the 1583 AE-CB/COPD, 63.04% were male and 35.19% were female. 54.6% of them were older than 60 years. 81.87% of the patients produced sputum. Sputum bacteria culture, chest X-ray and chest CT were carried out to 21.3%, 66.3% and 11.1% patients, respectively. 355 strains were isolated from patients whose sputum bacteria culture was positive. Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were the three most isolates. 84.7% of the 1583 AE-CB/COPD received 1692 times of antibiotic prescribing. The most frequently prescribed antibiotic were B-lactams (51.36% of all antibiotic prescribing), macrolides (14.01%) and quinolones (31.03%). Much more macrolides were prescribed in the area where more patients pay the medicines at his own expense than those in the area where more patients share public health service. Conclusion In China, respiratory physicians can reasonably select antibiotics to manage acute exacerbation of chronic bronchitis/ chronic obstructive pulmonary disease in pulmonary outpatient department. Sputum culture is done in part of the patients, but susceptibility tests are missing. One issue revealed by the survey is that the list of prescribing medications laid down by government have great influence on antibiotic use.
文摘The present study was designed to determine the relationship between changes of plasma endothelin 1 concentrations and development of colonic obstruction in sleep.Colons were bound in three sheep with sterilized plastic tubes to make pathological model of colonic obstruction.Samples were collected before and after modeling operation on both controls and models.Endothelin 1 concentrations were measured by radioimmunoassay.Plasma ET llevels decreased continually after the modeling operation in the models,it dropped from a basal value of 60 93±18 66 to 34 11±8 22 and 33 54±11 12 pg/mL(P<0 05) on the 3rd and 5 th day,respectively,which were also lower than controls 64 16±12 93 pg/mL(P<0 05).It suggests that colonic obstruction may induce a decrease in plasma endothelin 1 concentrations in sleep.
基金The project supported by National Natural Science Foundation of China(81274172,81473267,30801535,81470003)
文摘OBJECTIVE The present study aimed to investigate the relationship between Wnt/β-catenin and Nrf2 signaling pathways,and understanding the mechanisms underlying the process of inflammatory in chronic obstructive pulmonary disease(COPD),which was a serious disease of respiratory system.METHODS We duplicate the emphysema model with porcine pancreatic elastase(PPE)in Nrf2-/-and WT mouse for 21d,and intraperitoneal injection of Li Cl,the activator of Wnt/β-catenin signaling pathway from 14 d to the end.Hematoxylin and eosin(H&E)staining was performed to assess the histopathologic level,and immunohistochemistry(IHC)for Mac-3(the marker of macrophagocyte)and Ly6G(the marker of neutrophil)was used to observe the inflammatory infiltrate,while the levels of Wnt/β-catenin and Nrf2 signaling pathways related proteins heme oxygenase-1(HO-1),NAD(P)H:quinone oxidoreductase 1(NQO1),and the expression of inflammatory cytokine interleukin-6(IL-6)were detected by Western blotting of lung tissues.In vitro,cigarette smoke extract(CSE)-treated normal human bronchial epithelial(NHBE)cells,cell viability was examined by MTT assay,and then we treated recombinant human Wnt3a,si Nrf2 and si Wnt3a to measure the expression of Wnt3a,β-catenin,Nrf2,HO-1,NQO-1,and IL-6.Cellular immunofluorescence staining was employed to identify the nuclear translocation of Nrf2.RESULTS We found that the Li Cl-treated group has markedly decreased the damage of alveolar structure and inflammatory signs than the model group of WT mice rather than Nrf2-/-group.It also seen that Li Cl not only increasedβ-catenin,but it also led to a comparable increase in Nrf2,HO-1,NQO1,and decrease of IL-6 compared with WT model groups but except to Nrf2-/-group in vivo.And it showed that Wnt3atreatment has significantly increased the nuclear translocation of Nrf2 and the expression of HO-1 and NQO1,reduced the IL-6 release,while there has no significance when Nrf2 was blocked in CSE-induced NHBE cells.CONCLUSION Our results demonstrated that Wnt3a/β-catenin significantly balanced oxidative stress and attenuated inflammation reaction by promoting Nrf2 nuclear translocation and activity.
文摘肾间质纤维化是几乎每种类型的慢性肾病不可避免的后果,然而其潜在机制尚未完全清楚。Tian等在既往的研究中确定,表面活性蛋白A（surfactant protein A,SP-A）是参与单侧输尿管梗阻（unilateral ureter obstruction,UUO）诱导的肾纤维化的一种新的蛋白因子。UUO诱导小鼠肾上皮中SP-A表达,可能是由于增加的酸性应激和炎症。
