背景目前多数研究者们认为在胃肠功能受损时,血清HSP70具有较高的敏感性,为早期肠缺血的敏感指标,但血清中热休克蛋白70(HSP70)在创伤性颅脑外伤(traumatic head injury,TBI)患者的胃肠功能评估中的研究较少,值得进一步研究.目的探究TB...背景目前多数研究者们认为在胃肠功能受损时,血清HSP70具有较高的敏感性,为早期肠缺血的敏感指标,但血清中热休克蛋白70(HSP70)在创伤性颅脑外伤(traumatic head injury,TBI)患者的胃肠功能评估中的研究较少,值得进一步研究.目的探究TBI合并急性胃肠功能损伤(acute gastrointestinal impairment,AGI)患者HSP70水平的变化及意义.方法选取2019-03/2020-10期间天津医科大学总医院重症监护病房就诊并住院的TBI合并AGI患者133例作为研究对象,按照改良Glasgow昏迷评分法并结合创伤性颅脑损伤临床分型标准,将研究对象分为轻型63例,中型32例,重型38例;按照AGI分级标准,将研究对象分为AGIⅠ级68例,AGIⅡ级37例,AGIⅢ级17例,AGIⅣ级11例.另选取50例于我院进行常规体检的无颅脑外伤病史、各系统基础疾病者作为对照组.比较不同脑外伤程度及不同AGI分级患者与对照组血清中HSP70水平,并分析TBI合并AGI患者血清HSP70水平与脑损伤程度、AGI分级的相关性,同时分析其单独诊断TBI合并AGI的诊断效能.结果入院当天,随着脑损伤程度的加重,血清HSP70水平也逐渐升高,且各型HSP70水平均显著高于对照组患者,而随着AGI分级的提高,血清HSP70水平也逐渐升高,且各分级HSP70水平均显著高于对照组患者,差异均有统计学意义(P<0.05);入院第3天,各型血清HSP70水平较入院当天数值明显降低,但数值仍高于对照组患者,而各分级血清HSP70水平较入院当天数值明显降低,但数值仍高于对照组患者,差异均有统计学意义(P<0.05);Pearson检验发现,TBI合并AGI患者血清HSP70水平与脑损伤程度、AGI分级均呈显著正相关(r_(s)=0.802、0.836,P<0.01);ROC曲线显示,血清HSP70诊断TBI合并AGI的试验准确性较高,AUC为0.803,95%CI为0.720-0.872.当最佳截断值为258.50 ng/L时,敏感度为80.94%,特异度为87.93%,约登指数为0.501.结论HSP70在TBI合并AGI患者血清中的表达显著上调,可能与疾病发展进程有关,对TBI合并AGI有较高的诊断价值.展开更多
Flow discharge from the river basin into the sea has severe impacts on the immediate vicinity of river channels, estuaries, and coastal areas. This paper analyzes the features and temporal trends of flow discharge at ...Flow discharge from the river basin into the sea has severe impacts on the immediate vicinity of river channels, estuaries, and coastal areas. This paper analyzes the features and temporal trends of flow discharge at Pearl River＇s three main gauge stations： the Wuzhou, Shijiao, and Boluo gauge stations on the West River, North River, and East River, respectively. The results show no significant trend in annual mean discharge into the sea at the three gauge stations. Changes of monthly mean discharge at the Boluo Gauge Station are evident, and a majority of monthly discharge in the dry season displays significant increasing trends. Furthermore, changes of the extreme discharge are quite evident, with a significant decreasing trend in the annual maximum discharge and a significant increasing trend in the minimum one. The significantly decreasing ratio of the flood discharge to annual discharge at the Boluo Gauge Station indicates that the flow discharge from the East River has increased in the dry season and decreased in the flood season since the construction of dams and reservoirs. At the other two gauge stations, the Wuzhou and Shijiao gauge stations, the seasonal discharge generally does not change perceptibly. Human impacts, especially those pertaining to reservoir and dam construction, appear to be responsible for the seasonal variation of flow discharge. The results indicate that the construction and operation of dams and reservoirs in the East River have a greater influence on flow discharge, which can well explain why the seasonal variation of flow discharge from the East River is more evident.展开更多
Background： Renal cell carcinoma （RCC） is the most common type of malignant renal tumors with a growing incidence in tile recent years. This study aimed to investigate the influencing factors and variation trend of...Background： Renal cell carcinoma （RCC） is the most common type of malignant renal tumors with a growing incidence in tile recent years. This study aimed to investigate the influencing factors and variation trend of hospitalization expenditures among RCC patients in a single-centered hospital in Beijing during 5 consecutive years and to find the major cost items and fluctuation tendency of inpatient medical expenditures. Methods： The inlbrmation of medical expenditures among RCC patients in a Grade-A tertiary hospital during the years 2012-2016 was investigated to find the main cost items and changes affecting the medical cost structure. Gray correlation method was adopted in quantitative analysis to analyze the composition of medical expenditures, and the variation of hospitalization expense structure during tile five years was studied by analyzing the degree of structural variation. Results： The cost item constitution of the hospitalization expenditures among RCC patients was relatively stable in the sample hospital during the past five years. To be specific, drug costs accounted for tile largest proportion of medical expenditures each year, with the highest of 37.81% in 2012, and showed a slowly declining tendency in the coming years. The cost item with the highest correlation degree ~as drug costs, with the value of 1.0000; followed by the costs of surgeries, 0.8423. Furthermore, drug costs shared the largest proportion （40.95%） of structural variation, followed by the costs of surgeries （18.35%）. Conclusions： Drug costs are the major influencing factors of the hospitalization expenditures among RCC patients. Thus, reasonable control on excessive drugs as well as the standardization of the diagnosis and treatment behaviors is conducive in reducing medical expenditures as well as easing patients＇ economic burdens. Besides, the positive growth on surgery costs suggests that the labor value of medical staffs has been gradually recognized.展开更多
To investigate the macro and micro behaviors of TRIP （transformation induced plasticity） steel under biaxial loading, experiment and finite element simulation were carried out for TRIP780 steel under proportional bi...To investigate the macro and micro behaviors of TRIP （transformation induced plasticity） steel under biaxial loading, experiment and finite element simulation were carried out for TRIP780 steel under proportional biaxial tension with displacement ratio of 1 ： 1, 2 ： 1, 3 ： 1 and 4 ： 1, respectively. The results show that cruciform specimens of TRIP780 steel fractured under proportional biaxial stretching when effective strain was about L 5 %, and fracture was always generated on the cross arm or cross links. During biaxial tension, stress and strain components in x and y directions of the center of the samples have the same nonlinear developing tendency, decreasing in one direction and increasing in another direction. Equal biaxial stretching stress state was helpful for retained austenite-martensite transformation than the other biaxial stress state. With increasing displacement ratio （DR） from 1 ： 1 to 4 ： 1, corresponding stress distributed unevenly on the yield ellipse from 30° to 60° in the first quadrant of stress space and corresponding retained austenite volume fraction distributed symmetrically in bow tie format.展开更多
Developing highly bioactive scaffold materials to promote stem cell migration,proliferation and tissue-specific differentiation is a crucial requirement in current tissue engineering and regenerative medicine.Our prev...Developing highly bioactive scaffold materials to promote stem cell migration,proliferation and tissue-specific differentiation is a crucial requirement in current tissue engineering and regenerative medicine.Our previous work has demonstrated that the decellularized tendon slices(DTSs)are able to promote stem cell proliferation and tenogenic differentiation in vitro and show certain pro-regenerative capacity for rotator cuff tendon regeneration in vivo.In this study,we present a strategy to further improve the bioactivity of the DTSs for constructing a novel highly bioactive tendon-regenerative scaffold by surface modification of tendon-specific stem cell-derived extracellular matrix(tECM),which is expected to greatly enhance the capacity of scaffold material in regulating stem cell behavior,including migration,proliferation and tenogenic differentiation.We prove that the modification of tECM could change the highly aligned surface topographical cues of the DTSs,retain the surface stiffness of the DTSs and significantly increase the content of multiple ECM components in the tECM-DTSs.As a result,the tECM-DTSs dramatically enhance the migration,proliferation as well as tenogenic differentiation of rat bone marrow-derived stem cells compared with the DTSs.Collectively,this strategy would provide a new way for constructing ECMbased biomaterials with enhanced bioactivity for in situ tendon regeneration applications.展开更多
基金supported by the National Natural Science Foundation of China(Grants No.41006046and51061130545)the Special Fund for Public Welfare Industry of Ministry of Water Resources of China(GrantNo.201301072)+1 种基金the New Teachers'Fund for Doctor Stations of the Ministry of Education of China(GrantNo.20100094120008)the Special Fund of State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering of Hohai University(Grants No.2009586712and2009585812)
文摘Flow discharge from the river basin into the sea has severe impacts on the immediate vicinity of river channels, estuaries, and coastal areas. This paper analyzes the features and temporal trends of flow discharge at Pearl River＇s three main gauge stations： the Wuzhou, Shijiao, and Boluo gauge stations on the West River, North River, and East River, respectively. The results show no significant trend in annual mean discharge into the sea at the three gauge stations. Changes of monthly mean discharge at the Boluo Gauge Station are evident, and a majority of monthly discharge in the dry season displays significant increasing trends. Furthermore, changes of the extreme discharge are quite evident, with a significant decreasing trend in the annual maximum discharge and a significant increasing trend in the minimum one. The significantly decreasing ratio of the flood discharge to annual discharge at the Boluo Gauge Station indicates that the flow discharge from the East River has increased in the dry season and decreased in the flood season since the construction of dams and reservoirs. At the other two gauge stations, the Wuzhou and Shijiao gauge stations, the seasonal discharge generally does not change perceptibly. Human impacts, especially those pertaining to reservoir and dam construction, appear to be responsible for the seasonal variation of flow discharge. The results indicate that the construction and operation of dams and reservoirs in the East River have a greater influence on flow discharge, which can well explain why the seasonal variation of flow discharge from the East River is more evident.
文摘Background： Renal cell carcinoma （RCC） is the most common type of malignant renal tumors with a growing incidence in tile recent years. This study aimed to investigate the influencing factors and variation trend of hospitalization expenditures among RCC patients in a single-centered hospital in Beijing during 5 consecutive years and to find the major cost items and fluctuation tendency of inpatient medical expenditures. Methods： The inlbrmation of medical expenditures among RCC patients in a Grade-A tertiary hospital during the years 2012-2016 was investigated to find the main cost items and changes affecting the medical cost structure. Gray correlation method was adopted in quantitative analysis to analyze the composition of medical expenditures, and the variation of hospitalization expense structure during tile five years was studied by analyzing the degree of structural variation. Results： The cost item constitution of the hospitalization expenditures among RCC patients was relatively stable in the sample hospital during the past five years. To be specific, drug costs accounted for tile largest proportion of medical expenditures each year, with the highest of 37.81% in 2012, and showed a slowly declining tendency in the coming years. The cost item with the highest correlation degree ~as drug costs, with the value of 1.0000; followed by the costs of surgeries, 0.8423. Furthermore, drug costs shared the largest proportion （40.95%） of structural variation, followed by the costs of surgeries （18.35%）. Conclusions： Drug costs are the major influencing factors of the hospitalization expenditures among RCC patients. Thus, reasonable control on excessive drugs as well as the standardization of the diagnosis and treatment behaviors is conducive in reducing medical expenditures as well as easing patients＇ economic burdens. Besides, the positive growth on surgery costs suggests that the labor value of medical staffs has been gradually recognized.
基金Item Sponsored by National Natural Science Foundation of China(51075034)
文摘To investigate the macro and micro behaviors of TRIP （transformation induced plasticity） steel under biaxial loading, experiment and finite element simulation were carried out for TRIP780 steel under proportional biaxial tension with displacement ratio of 1 ： 1, 2 ： 1, 3 ： 1 and 4 ： 1, respectively. The results show that cruciform specimens of TRIP780 steel fractured under proportional biaxial stretching when effective strain was about L 5 %, and fracture was always generated on the cross arm or cross links. During biaxial tension, stress and strain components in x and y directions of the center of the samples have the same nonlinear developing tendency, decreasing in one direction and increasing in another direction. Equal biaxial stretching stress state was helpful for retained austenite-martensite transformation than the other biaxial stress state. With increasing displacement ratio （DR） from 1 ： 1 to 4 ： 1, corresponding stress distributed unevenly on the yield ellipse from 30° to 60° in the first quadrant of stress space and corresponding retained austenite volume fraction distributed symmetrically in bow tie format.
基金supported by the grants from National Natural Science Foundation of China(grant numbers:32171349,31600783,31870968)Science and Technology Plan of Sichuan Province(grant number:2018SZ0044).
文摘Developing highly bioactive scaffold materials to promote stem cell migration,proliferation and tissue-specific differentiation is a crucial requirement in current tissue engineering and regenerative medicine.Our previous work has demonstrated that the decellularized tendon slices(DTSs)are able to promote stem cell proliferation and tenogenic differentiation in vitro and show certain pro-regenerative capacity for rotator cuff tendon regeneration in vivo.In this study,we present a strategy to further improve the bioactivity of the DTSs for constructing a novel highly bioactive tendon-regenerative scaffold by surface modification of tendon-specific stem cell-derived extracellular matrix(tECM),which is expected to greatly enhance the capacity of scaffold material in regulating stem cell behavior,including migration,proliferation and tenogenic differentiation.We prove that the modification of tECM could change the highly aligned surface topographical cues of the DTSs,retain the surface stiffness of the DTSs and significantly increase the content of multiple ECM components in the tECM-DTSs.As a result,the tECM-DTSs dramatically enhance the migration,proliferation as well as tenogenic differentiation of rat bone marrow-derived stem cells compared with the DTSs.Collectively,this strategy would provide a new way for constructing ECMbased biomaterials with enhanced bioactivity for in situ tendon regeneration applications.
