目的分析白介素-4(interleukin-4,IL-4)联合急性生理与慢性健康评分(acute physiology and chronic health evaluation,APACHEⅡ)对耐碳青霉烯鲍曼不动杆菌(carbapenem-resistant Acinetobacter baumannii,CRAB)感染的预后评估价值。方...目的分析白介素-4(interleukin-4,IL-4)联合急性生理与慢性健康评分(acute physiology and chronic health evaluation,APACHEⅡ)对耐碳青霉烯鲍曼不动杆菌(carbapenem-resistant Acinetobacter baumannii,CRAB)感染的预后评估价值。方法将2021年11月至2023年10月在广东医科大学附属医院接受治疗的143例CRAB感染患者设为研究组,取同期院内治疗的碳青霉烯敏感鲍曼不动杆菌感染患者49例为对照组,根据研究组患者的临床结局区分为死亡组(n=46)和存活组(n=97)。对比研究组与对照组、死亡组与存活组患者IL-4和APACHEⅡ评分差异,采用Pearson相关性分析的方式,计算CRAB感染患者血清IL-4水平同APACHEⅡ评分的相关性,并采用绘制受试者工作(receiver operating characteristic curves,ROC)曲线的方式评估IL-4、APACHEⅡ评分以及联合诊断在预测CRAB感染患者不良临床结局中的应用价值。结果死亡组患者的IL-4水平以及APACHEⅡ评分显著高于存活组患者,组间差异具有统计学意义(P<0.05)。Pearson相关性分析结果显示血清IL-4水平与APACHEⅡ评分具有明显的正相关性(r=0.093,P<0.001)。血清IL-4、APACHEⅡ评分以及联合检测对CRAB感染患者预后评估AUC分别为0.712(95%CI=0.606~0.817,P<0.001)、0.849(95%CI=0.763~0.936,P<0.001)和0.956(95%CI=0.927~0.985,P<0.001)。结论CRAB患者不良预后者血清IL-4和APACHEⅡ评分较存活组显著升高,可以考虑将血清IL-4和APACHEⅡ评分联合应用于此类患者预后评估中,有助于为其临床治疗提供参考。展开更多
The microstructure evolution and high-temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints under different welding parameters were studied.The results show that the weld fus...The microstructure evolution and high-temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints under different welding parameters were studied.The results show that the weld fusion zone of TC4/TA15 dissimilar welded joints consists of coarsenedβcolumnar crystals that contain mainly acicularα’martensite.The heat affected zone is composed of the initialαphase and the transformedβstructure,and the width of heat affected zone on the TA15 side is narrower than that on the TC4 side.With increasing temperature,the yield strength and ultimate tensile strength of the TC4/TA15 dissimilar welded joints decrease and the highest plastic deformation is obtained at 800°C.The tensile strength of the dissimilar joints with different welding parameters and base material satisfies the following relation(from high to low):TA15 base material>dissimilar joints>TC4 base material.The microhardness of a cross-section of the TC4/TA15 dissimilar joints reaches a maximum at the centre of the weld and is reduced globally after heat treatment,but the microhardness distribution is not changed.An elevated temperature tensile fracture of the dissimilar joints is located on the side of the TC4 base material.Necking occurs during the tensile tests and the fracture characteristics are typical when ductility is present in the material.展开更多
The welding joints of Zircaloy 4 plates obtained by diffusion welding at 800°C under pressure in vacuum were cracked during autoclave tests at 400°C superheated steam after exposure longer than 150 days. T...The welding joints of Zircaloy 4 plates obtained by diffusion welding at 800°C under pressure in vacuum were cracked during autoclave tests at 400°C superheated steam after exposure longer than 150 days. The section of specimens was examined by optical microscopy and the composition at the tips of cracking was analyzed by electron microprobe. The result shows that the combination of oxidation and hydriding induced cracking is responsible for this failure of the welding joints.展开更多
Vacuum brazing of SiO2 glass ceramic and TC4 alloy using a commercially available TiZrNiCu foil was investigated. The interfacial microstructure and the fractures were examined with an optical microscope （OM） and an...Vacuum brazing of SiO2 glass ceramic and TC4 alloy using a commercially available TiZrNiCu foil was investigated. The interfacial microstructure and the fractures were examined with an optical microscope （OM） and an S-4700 scanning electron microscope （SEM） equipped with an energy dispersive spectrometer （EDS） and an electron probe X-ray microanalyzer （EPMA）. The structure of joint interface was identified by XRD （JDX-3530M）. Meanwhile, the fracture paths of the joints were comprehensively studied. The results show that processing parameters, especially the brazing temperature, have a significant effect on the microstructure and mechanical properties of joints. The typical interface structure is SiO2/Ti2O＋Zr3Si2＋Ti5Si3/（Ti,Zr）＋Ti2O＋ TiZrNiCu/Ti（s.s）/TiZrNiCu＋Ti（s.s）＋Ti2（Cu,Ni）/TC4 from SiO2 glass ceramic to TC4 alloy side. Based on the mechanical property tests, the joints brazed at 880 ℃ for 5 rain has the maximum shear strength of 23 MPa.展开更多
Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical ...Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical modelling approaches are helpful towards this goal. This study aims at developing Bayesian joint models with assumed generalized error distribution (GED) for the longitudinal CD4 data and two accelerated failure time distributions, Lognormal and loglogistic, for the survival time of HIV/AIDS patients. Data are obtained from patients under antiretroviral therapy follow-up at Shashemene referral hospital during January 2006-January 2012 and at Bale Robe general hospital during January 2008-March 2015. The Bayesian joint models are defined through latent variables and association parameters and with specified non-informative prior distributions for the model parameters. Simulations are conducted using Gibbs sampler algorithm implemented in the WinBUGS software. The results of the analyses of the two different data sets show that distributions of measurement errors of the longitudinal CD4 variable follow the generalized error distribution with fatter tails than the normal distribution. The Bayesian joint GED loglogistic models fit better to the data sets compared to the lognormal cases. Findings reveal that patients’ health can be improved over time. Compared to the males, female patients gain more CD4 counts. Survival time of a patient is negatively affected by TB infection. Moreover, increase in number of opportunistic infection implies decline of CD4 counts. Patients’ age negatively affects the disease marker with no effects on survival time. Improving weight may improve survival time of patients. Bayesian joint models with GED and AFT distributions are found to be useful in modelling the longitudinal and survival processes. Thus we recommend the generalized error distributions for measurement errors of the longitudinal data under the Bayesian joint modelling. Further studies may investigate the models with various types of shared random effects and more covariates with predictions.展开更多
In this paper, the vacuum brazing of Si3N4 ceramic was carried out with Ti40Zr25Ni15Cu20 amorphous filler metal. The interfacial microstructure was investigated by scanning electron microscopy （ SEM ）, energy disper...In this paper, the vacuum brazing of Si3N4 ceramic was carried out with Ti40Zr25Ni15Cu20 amorphous filler metal. The interfacial microstructure was investigated by scanning electron microscopy （ SEM ）, energy dispersive spectroscopy （EDS） etc. According to the analysis, the interface reaction layer was mode up of TiN abut on the ceramic and the Ti-Si, Zr-Si compounds. The influence of brazing temperature and holding time on the joint strength was also studied. The results shows that the joint strength first increased and then decreased with the increasing of holding time and brazing temperature. The joint strength was significantly affected by the thickness of the reaction layer. Under the same experimental conditions, the joint brazed with amorphous filler metal exhibits much higher strength compared with the one brazed with crystalline filler metal with the same composition. To achieve higher joint strength at relatively low temperature, it is favorable to use the amorphous filler metal than the crystalline filler metal.展开更多
By using newly developed CuNi5~25Ti16~28 B rapldly solidifled brazing filler the joining of Si3 N4/1.25Cr-0.5Mo steel has been carried out with interlayer method. If employing the interlayer structure of steel (0.2 mm...By using newly developed CuNi5~25Ti16~28 B rapldly solidifled brazing filler the joining of Si3 N4/1.25Cr-0.5Mo steel has been carried out with interlayer method. If employing the interlayer structure of steel (0.2 mm)/W (2.0 mm)/Ni(0.2 mm), the joint strength can be increased greatly compared with employing that of Ni/W/Ni, and the three point bend strength of the Joint shows the value of 261 MPa. The metallurgical behaviour at the interface between Si3N4 and the interlayer has been studied. It is found that Fe participated in the interfacial reactions between Si3N4 and the brazing filler at the Si3N4/steel (0.2 mm) interface and the compound Fe5Si3 was produced. However, since the reactions of Fe with the active Ti are weaker than those of Ni with Ti, the normal inter facial reactions were still assured at the interface of Si3N4/steel (0.2 mm) instead of Si3N4/Ni (0.2 mm), resulting in the improvement of the joint strength. The mechanism of the formation of Fe5Si3 is also discussed. Finally, some ideas to further ameliorate and simplify the interlayer structure are put forward.展开更多
Objective:To investigate the expression changes and clinical significance of Toll-like receptor-4(TLR-4)and interleukin-1β(IL-1β)in the serum and knee joint fluid in patients with knee osteoarthritis(KOA).Methods:Fr...Objective:To investigate the expression changes and clinical significance of Toll-like receptor-4(TLR-4)and interleukin-1β(IL-1β)in the serum and knee joint fluid in patients with knee osteoarthritis(KOA).Methods:From June 2017 to December 2018,220 cases of patients with KOA who were admitted in Department of Orthopedics of the Third Affiliated Hospital of Inner Mongolia Medical University(“our hospital”for short)were selected as the observation group.According to the severity of KOA,they were divided into the mild subgroup(n=98),the moderate subgroup(n=80)and the severe subgroup(n=42).In addition,60 cases of volunteers who received the physical examination in Health Medical Center of our hospital were selected as the control group.The levels of TLR-4 and IL-1βin the serum and knee joint fluid were detected by enzyme-linked immunosorbent assay,in order to analyze the correlation of TLR-4 and IL-1βlevels with the severity of KOA.Results:The levels of TLR-4 and IL-1βin the serum and knee joint fluid of the observation group were significantly higher than those of the control group,and the differences were statistically significant(all p<.05).The levels of TLR-4 and IL-1βin the serum and knee joint fluid of the severe subgroup were significantly higher than those of the mild subgroup and the moderate subgroup,and the levels of TLR-4 and IL-1βin the serum and knee joint fluid of the moderate subgroup were higher than those of the mild group.The differences were statistically significant(all p<.05).The levels of TLR-4 and IL-1βin the serum and knee joint fluid were positively correlated to the severity of KOA(r=.706,.729,.741,.715,all p<.05);in the serum,the level of TLR-4 was positively correlated to the level of IL-1β(r=.720,p<.05);in the joint fluid,the level of TLR-4 was positively correlated to the level of IL-1β(r=.736,p<.05).Conclusions:The levels of TLR-4 and IL-1βin the serum and knee joint fluid of KOA patients are abnormally increased,which is closely related with the severity of KOA.It can be used for clinical prediction,diagnosis and treatment of KOA.展开更多
With the growth of the online market,demand for logistics and courier cargo is increasing rapidly.Accordingly,in the case of urban areas,road congestion and environmental problems due to cargo vehicles are mainly occu...With the growth of the online market,demand for logistics and courier cargo is increasing rapidly.Accordingly,in the case of urban areas,road congestion and environmental problems due to cargo vehicles are mainly occurring.The joint courier logistics system,a plan to solve this problem,aims to establish an efficient logistics transportation system by utilizing one joint logistics delivery terminal by several logistics and delivery companies.However,several courier companies use different types of courier invoices.Such a system has a problem of information data transmission interruption.Therefore,the data processing process was systematically analyzed,a practically feasible methodology was devised,and delivery invoice information processing standards were established for this.In addition,the importance of this paper can be emphasized in terms of data processing in the logistics sector,which is expected to grow rapidly in the future.The results of this study can be used as basic data for the implementation of the logistics joint delivery terminal system in the future.And it can be used as a basis for securing the operational reliability of the joint courier logistics system.展开更多
基金Project(51405392)supported by the National Natural Science Foundation of ChinaProject(2019T120954)supported by the China Postdoctoral Science Foundation+1 种基金Project(2018BSHQYXMZZ31)supported by the Shaanxi Provincial Postdoctoral Science Foundation,ChinaProject(3102019MS0404)supported by the Fundamental Research Funds for the Central Universities,China.
文摘The microstructure evolution and high-temperature mechanical properties of laser beam welded TC4/TA15 dissimilar titanium alloy joints under different welding parameters were studied.The results show that the weld fusion zone of TC4/TA15 dissimilar welded joints consists of coarsenedβcolumnar crystals that contain mainly acicularα’martensite.The heat affected zone is composed of the initialαphase and the transformedβstructure,and the width of heat affected zone on the TA15 side is narrower than that on the TC4 side.With increasing temperature,the yield strength and ultimate tensile strength of the TC4/TA15 dissimilar welded joints decrease and the highest plastic deformation is obtained at 800°C.The tensile strength of the dissimilar joints with different welding parameters and base material satisfies the following relation(from high to low):TA15 base material>dissimilar joints>TC4 base material.The microhardness of a cross-section of the TC4/TA15 dissimilar joints reaches a maximum at the centre of the weld and is reduced globally after heat treatment,but the microhardness distribution is not changed.An elevated temperature tensile fracture of the dissimilar joints is located on the side of the TC4 base material.Necking occurs during the tensile tests and the fracture characteristics are typical when ductility is present in the material.
文摘The welding joints of Zircaloy 4 plates obtained by diffusion welding at 800°C under pressure in vacuum were cracked during autoclave tests at 400°C superheated steam after exposure longer than 150 days. The section of specimens was examined by optical microscopy and the composition at the tips of cracking was analyzed by electron microprobe. The result shows that the combination of oxidation and hydriding induced cracking is responsible for this failure of the welding joints.
基金Project(50705022) supported by the National Natural Science Foundation of ChinaProject(HIT0804) supported by the Foundation of the National Key Laboratory of Precision Hot Processing of Metals,ChinaProject supported by Program of Excellent Team in Harbin Institute of Technology,China
文摘Vacuum brazing of SiO2 glass ceramic and TC4 alloy using a commercially available TiZrNiCu foil was investigated. The interfacial microstructure and the fractures were examined with an optical microscope （OM） and an S-4700 scanning electron microscope （SEM） equipped with an energy dispersive spectrometer （EDS） and an electron probe X-ray microanalyzer （EPMA）. The structure of joint interface was identified by XRD （JDX-3530M）. Meanwhile, the fracture paths of the joints were comprehensively studied. The results show that processing parameters, especially the brazing temperature, have a significant effect on the microstructure and mechanical properties of joints. The typical interface structure is SiO2/Ti2O＋Zr3Si2＋Ti5Si3/（Ti,Zr）＋Ti2O＋ TiZrNiCu/Ti（s.s）/TiZrNiCu＋Ti（s.s）＋Ti2（Cu,Ni）/TC4 from SiO2 glass ceramic to TC4 alloy side. Based on the mechanical property tests, the joints brazed at 880 ℃ for 5 rain has the maximum shear strength of 23 MPa.
文摘Survival of HIV/AIDS patients is crucially dependent on comprehensive and targeted medical interventions such as supply of antiretroviral therapy and monitoring disease progression with CD4 T-cell counts. Statistical modelling approaches are helpful towards this goal. This study aims at developing Bayesian joint models with assumed generalized error distribution (GED) for the longitudinal CD4 data and two accelerated failure time distributions, Lognormal and loglogistic, for the survival time of HIV/AIDS patients. Data are obtained from patients under antiretroviral therapy follow-up at Shashemene referral hospital during January 2006-January 2012 and at Bale Robe general hospital during January 2008-March 2015. The Bayesian joint models are defined through latent variables and association parameters and with specified non-informative prior distributions for the model parameters. Simulations are conducted using Gibbs sampler algorithm implemented in the WinBUGS software. The results of the analyses of the two different data sets show that distributions of measurement errors of the longitudinal CD4 variable follow the generalized error distribution with fatter tails than the normal distribution. The Bayesian joint GED loglogistic models fit better to the data sets compared to the lognormal cases. Findings reveal that patients’ health can be improved over time. Compared to the males, female patients gain more CD4 counts. Survival time of a patient is negatively affected by TB infection. Moreover, increase in number of opportunistic infection implies decline of CD4 counts. Patients’ age negatively affects the disease marker with no effects on survival time. Improving weight may improve survival time of patients. Bayesian joint models with GED and AFT distributions are found to be useful in modelling the longitudinal and survival processes. Thus we recommend the generalized error distributions for measurement errors of the longitudinal data under the Bayesian joint modelling. Further studies may investigate the models with various types of shared random effects and more covariates with predictions.
基金Funded by National Natural Science Foundation of China （No. 50875117）.
文摘In this paper, the vacuum brazing of Si3N4 ceramic was carried out with Ti40Zr25Ni15Cu20 amorphous filler metal. The interfacial microstructure was investigated by scanning electron microscopy （ SEM ）, energy dispersive spectroscopy （EDS） etc. According to the analysis, the interface reaction layer was mode up of TiN abut on the ceramic and the Ti-Si, Zr-Si compounds. The influence of brazing temperature and holding time on the joint strength was also studied. The results shows that the joint strength first increased and then decreased with the increasing of holding time and brazing temperature. The joint strength was significantly affected by the thickness of the reaction layer. Under the same experimental conditions, the joint brazed with amorphous filler metal exhibits much higher strength compared with the one brazed with crystalline filler metal with the same composition. To achieve higher joint strength at relatively low temperature, it is favorable to use the amorphous filler metal than the crystalline filler metal.
文摘By using newly developed CuNi5~25Ti16~28 B rapldly solidifled brazing filler the joining of Si3 N4/1.25Cr-0.5Mo steel has been carried out with interlayer method. If employing the interlayer structure of steel (0.2 mm)/W (2.0 mm)/Ni(0.2 mm), the joint strength can be increased greatly compared with employing that of Ni/W/Ni, and the three point bend strength of the Joint shows the value of 261 MPa. The metallurgical behaviour at the interface between Si3N4 and the interlayer has been studied. It is found that Fe participated in the interfacial reactions between Si3N4 and the brazing filler at the Si3N4/steel (0.2 mm) interface and the compound Fe5Si3 was produced. However, since the reactions of Fe with the active Ti are weaker than those of Ni with Ti, the normal inter facial reactions were still assured at the interface of Si3N4/steel (0.2 mm) instead of Si3N4/Ni (0.2 mm), resulting in the improvement of the joint strength. The mechanism of the formation of Fe5Si3 is also discussed. Finally, some ideas to further ameliorate and simplify the interlayer structure are put forward.
文摘Objective:To investigate the expression changes and clinical significance of Toll-like receptor-4(TLR-4)and interleukin-1β(IL-1β)in the serum and knee joint fluid in patients with knee osteoarthritis(KOA).Methods:From June 2017 to December 2018,220 cases of patients with KOA who were admitted in Department of Orthopedics of the Third Affiliated Hospital of Inner Mongolia Medical University(“our hospital”for short)were selected as the observation group.According to the severity of KOA,they were divided into the mild subgroup(n=98),the moderate subgroup(n=80)and the severe subgroup(n=42).In addition,60 cases of volunteers who received the physical examination in Health Medical Center of our hospital were selected as the control group.The levels of TLR-4 and IL-1βin the serum and knee joint fluid were detected by enzyme-linked immunosorbent assay,in order to analyze the correlation of TLR-4 and IL-1βlevels with the severity of KOA.Results:The levels of TLR-4 and IL-1βin the serum and knee joint fluid of the observation group were significantly higher than those of the control group,and the differences were statistically significant(all p<.05).The levels of TLR-4 and IL-1βin the serum and knee joint fluid of the severe subgroup were significantly higher than those of the mild subgroup and the moderate subgroup,and the levels of TLR-4 and IL-1βin the serum and knee joint fluid of the moderate subgroup were higher than those of the mild group.The differences were statistically significant(all p<.05).The levels of TLR-4 and IL-1βin the serum and knee joint fluid were positively correlated to the severity of KOA(r=.706,.729,.741,.715,all p<.05);in the serum,the level of TLR-4 was positively correlated to the level of IL-1β(r=.720,p<.05);in the joint fluid,the level of TLR-4 was positively correlated to the level of IL-1β(r=.736,p<.05).Conclusions:The levels of TLR-4 and IL-1βin the serum and knee joint fluid of KOA patients are abnormally increased,which is closely related with the severity of KOA.It can be used for clinical prediction,diagnosis and treatment of KOA.
基金supported by a grant from R&D program of the Korea Evaluation Institute of Industrial Technology(20015047).
文摘With the growth of the online market,demand for logistics and courier cargo is increasing rapidly.Accordingly,in the case of urban areas,road congestion and environmental problems due to cargo vehicles are mainly occurring.The joint courier logistics system,a plan to solve this problem,aims to establish an efficient logistics transportation system by utilizing one joint logistics delivery terminal by several logistics and delivery companies.However,several courier companies use different types of courier invoices.Such a system has a problem of information data transmission interruption.Therefore,the data processing process was systematically analyzed,a practically feasible methodology was devised,and delivery invoice information processing standards were established for this.In addition,the importance of this paper can be emphasized in terms of data processing in the logistics sector,which is expected to grow rapidly in the future.The results of this study can be used as basic data for the implementation of the logistics joint delivery terminal system in the future.And it can be used as a basis for securing the operational reliability of the joint courier logistics system.
