BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patie...BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patients with diabetes are unknown.In this study,we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation.AIM To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage.METHODS BMSC-exo were isolated from mouse BMSC media.This was followed by transfection with microRNA-129-5p(miR-129-5p).BMSC-exo or miR-129-5poverexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucoseaffected BV2 cells for in vitro analyses.The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1(HMGB1).Quantitative polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors,such as HMGB1,interleukin 6,interleukin 1β,toll-like receptor 4,and tumor necrosis factorα.Brain water content,neural function deficit score,and Evans blue were used to measure the neural function of mice.RESULTS Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery.MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation.Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases.Furthermore,we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA.CONCLUSION We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes,thereby improving the neurological function of the brain.展开更多
AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed eithe...AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.展开更多
This paper presents a constitutive framework for finite element analysis of the truck beam end cutting process.For this purpose,a finite strain anisotropic elasto-plastic model,which takes nonlinear kinematic and isot...This paper presents a constitutive framework for finite element analysis of the truck beam end cutting process.For this purpose,a finite strain anisotropic elasto-plastic model,which takes nonlinear kinematic and isotropic hardening into account,is presented.Three factors are investigated to determine the effect on cutting quality:radius of cutting tools,strength of materials and relative clearance in cutting.The recommendations made herein are based on the simulation results.展开更多
The paper illustrates the reason of the lack of talents with outstanding innovative practice ability and engineering leadership has become a great obstacle for many industries, represented by the software industry, to...The paper illustrates the reason of the lack of talents with outstanding innovative practice ability and engineering leadership has become a great obstacle for many industries, represented by the software industry, to develop along with the new era, and restricted the evolution of these industries toward the high end. With the target of training talents with innovation capacity and engineering leadership, the training plan for top talents based on the demand for high-end talents in the software engineering industry is put forward, and analyses are given on significant aspects including the development of the training resource system, the screening of students and the selection of enterprises, the teaching staff construction for university-enterprise cooperation, the establishment of a management system with joint effort for talents development, and the construction of process quality guarantee mechanism. In the end, for the implementation of the training plan, it is pointed out that the university-enterprise cooperative development mechanism should be perfected, the talents development practice should be enhanced, the personalized training of students should be emphasized, and the innovative ability in practice and the engineering leadership of students should be practically improved.展开更多
Novel stable high-spin molecules possessing three different arranging fashions were designed with —^＊N—S— as a spin-containing （SC） fragment, an aromatic group, such as benzene （ 1 ）, pyridine （2）, pyridazi...Novel stable high-spin molecules possessing three different arranging fashions were designed with —^＊N—S— as a spin-containing （SC） fragment, an aromatic group, such as benzene （ 1 ）, pyridine （2）, pyridazine （3） , pyrimidine （4）, pyrazine （5） or triazine （6） as end groups （EG）, and phenyl as a ferromagnetic coupling （FC） unit. The effects of different EG on the spin multiplicities of the ground states and their stabilities were investigated by means of the AM1-CI approach. All the investigated molecules corresponded to the FC and possessed high-spin ground states. The spin on the two atoms of the SC fragment was not in agreement with the delocalization results in the specific stability of —^＊N—S—. In those molecules, the stabilities of the triplet states decreased when the distance between the atoms of central SC fragments （—N—） increased. The stabilities of the triplet states of compounds 1a-n, 1b-n and 1c-n, with heterocycles as EG were higher than those of the triplet states of those compounds with phenyl as EG. Furthermore, the stahilities of the triplet states of the compounds with pyrimidine and triazine as EG were higher than those with pyridine, pyridazine or pyrasine as EG.展开更多
Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more ...Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.展开更多
We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. Th...We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.展开更多
目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至202...目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至2022年2月我院收治的100例SP患儿为研究对象,根据患儿是否发生继发性ARDS将患儿分为ARDS组(n=56)和对照组(n=44),收集患儿一般资料,采集外周血以酶联免疫吸附法进行RAGE、HMGB1、IFN-γ和IL-4表达水平检测,采用多因素logistic回归分析SP患儿继发ARDS的影响因素,采用Pearson相关性分析其与IFN-γ/IL-4的相关性,并采用受试者工作曲线(ROC)分析RAGE、HMGB1表达对SP患儿继发ARDS的预测价值。结果两组SP患儿性别、年龄、体温以及发病季节之间无显著差异,ARDS组致病菌种类多于对照组,PaO_(2)/FiO_(2)和APS评分、血清RAGE、HMGB1、IFN-γ和IL-4表达水平以及IFN-γ/IL-4比值均高于对照组(P<0.05)。经多因素logistic回归分析可知,致病菌种类、PaO_(2)/FiO_(2)、RAGE、HMGB1表达、IFN-γ、IL-4和IFN-γ/IL-4均为SP患儿继发ARDS的影响因素。经Pearson相关检验,SP患儿血清RAGE、HMGB1表达水平与IFN-γ、IL-4和IFN-γ/IL-4均呈正相关(P<0.05)。经ROC曲线分析可得,血清RAGE、HMGB1水平预测SP患儿发生ARDS的AUC分别为0.707和0.750,灵敏度分别为73.2%、64.3%,特异度分别为68.2%、77.3%,两者联合预测的AUC为0.848,灵敏度和特异度分别为80.4%和81.8%。结论SP继发ARDS患儿血清中RAGE、HMGB1表达水平较高,与IFN-γ/IL-4呈正相关,监测患儿血清RAGE、HMGB1表达对SP患儿继发ARDS的风险有一定的预测价值。展开更多
Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the...Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.展开更多
A series of perovskite-like mixed oxides La2-xSrxMO4±λ(M =Cu, Co,Ni; x=0,1 ) was prepared and characterized using X-ray powder diffraction. The catalytic properties of these catalysts in NO decompositiori were t...A series of perovskite-like mixed oxides La2-xSrxMO4±λ(M =Cu, Co,Ni; x=0,1 ) was prepared and characterized using X-ray powder diffraction. The catalytic properties of these catalysts in NO decompositiori were tested. The results showed that LaSrNiO4-λ with K2NiF4 structure is very active and stable for the decomposition of NO.展开更多
Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. Accor...Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.展开更多
AIM:To evaluate the serum levels of endozepine-4,their relation with ammonia serum levels,the grading of coma and the severity of cirrhosis,in patients with hepatic coma. METHODS:In this study we included 20 subjects ...AIM:To evaluate the serum levels of endozepine-4,their relation with ammonia serum levels,the grading of coma and the severity of cirrhosis,in patients with hepatic coma. METHODS:In this study we included 20 subjects with Hepatic coma,20 subjects with minimal hepatic encephalopathy(MHE) and 20 subjects control. All subjects underwent blood analysis,Child Pugh and Model for End- stage liver disease(MELD) assessment,endozepine-4 analysis. RESULTS:Subjects with hepatic coma showed significant difference in endozepine-4(P < 0.001) and NH3 levels(P < 0.001) compared both to MHE and controls patients. Between NH3 and endozepine-4 we observed a significant correlation(P = 0.009; Pearson correlation 0.570). There was a significant correlation between endozepine-4 and MELD(P = 0.017; Pearsoncorrelation = 0.529). In our study blood ammonia concentration was noted to be raised in patients with hepatic coma,with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia(P < 0.001). In patients with grade Ⅳ hepatic coma,endozepine levels were significantly higher compared to other groups. CONCLUSION:This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion,data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations.展开更多
Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to impro...Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to improve oil recovery for high water-cut multilayered reservoirs. Dif- ferent regroup scenarios may lead to different production performances. Based on unstable oil-water flow theory, a multilayer commingled reservoir simulator is established by modifying the production split method. Taking into account the differences of layer properties, including per- meability, oil viscosity, and remaining oil saturation, the pseudo flow resistance contrast is proposed to serve as a characteristic index of layer regrouping for high water-cut multilayered reservoirs. The production indices of multi- layered reservoirs with different pseudo flow resistances are predicted with the established model in which the data are taken from the Shengtuo Oilfield. Simulation results show that the pseudo flow resistance contrast should be less than 4 when the layer regrouping is implemented. The K-means clustering method, which is based on the objec- tive function, is used to automatically carry out the layer regrouping process according to pseudo flow resistances. The research result is applied to the IV-VI sand groups of the second member of the Shahejie Formation in the Shengtuo Oilfield, a favorable development performance is obtained, and the oil recovery is enhanced by 6.08 %.展开更多
A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parki...A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson’s disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis.展开更多
The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compr...The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.展开更多
基金Supported by the National Natural Science Foundation of China,No.81900743Heilongjiang Province Outstanding Young Medical Talents Training Grant Project,China,No.HYD2020YQ0007.
文摘BACKGROUND Diabetic intracerebral hemorrhage(ICH)is a serious complication of diabetes.The role and mechanism of bone marrow mesenchymal stem cell(BMSC)-derived exosomes(BMSC-exo)in neuroinflammation post-ICH in patients with diabetes are unknown.In this study,we investigated the regulation of BMSC-exo on hyperglycemia-induced neuroinflammation.AIM To study the mechanism of BMSC-exo on nerve function damage after diabetes complicated with cerebral hemorrhage.METHODS BMSC-exo were isolated from mouse BMSC media.This was followed by transfection with microRNA-129-5p(miR-129-5p).BMSC-exo or miR-129-5poverexpressing BMSC-exo were intravitreally injected into a diabetes mouse model with ICH for in vivo analyses and were cocultured with high glucoseaffected BV2 cells for in vitro analyses.The dual luciferase test and RNA immunoprecipitation test verified the targeted binding relationship between miR-129-5p and high-mobility group box 1(HMGB1).Quantitative polymerase chain reaction,western blotting,and enzyme-linked immunosorbent assay were conducted to assess the levels of some inflammation factors,such as HMGB1,interleukin 6,interleukin 1β,toll-like receptor 4,and tumor necrosis factorα.Brain water content,neural function deficit score,and Evans blue were used to measure the neural function of mice.RESULTS Our findings indicated that BMSC-exo can promote neuroinflammation and functional recovery.MicroRNA chip analysis of BMSC-exo identified miR-129-5p as the specific microRNA with a protective role in neuroinflammation.Overexpression of miR-129-5p in BMSC-exo reduced the inflammatory response and neurological impairment in comorbid diabetes and ICH cases.Furthermore,we found that miR-129-5p had a targeted binding relationship with HMGB1 mRNA.CONCLUSION We demonstrated that BMSC-exo can reduce the inflammatory response after ICH with diabetes,thereby improving the neurological function of the brain.
文摘AIM To elucidate how high diet-induced endoplasmic reticulum-stress upregulates thioredoxin interacting protein expression in Müller cells leading to retinal inflammation. METHODS Male C57Bl/J mice were fed either normal diet or 60% high fat diet for 4-8 wk. During the 4 wk study, mice received phenyl-butyric acid(PBA); endoplasmic reticulum-stress inhibitor; for 2 wk. Insulin resistance was assessed by oral glucose tolerance. Effects of palmitate-bovine serum albumin(BSA)(400 μmol/L) were examined in retinal Müller glial cell line and primary Müller cells isolated from wild type and thioredoxin interacting protein knock-out mice. Expression of thioredoxin interacting protein, endoplasmic reticulum-stress markers, mi R-17-5p m RNA, as well as nucleotide-binding oligomerization domain-like receptor protein(NLRP3) and IL1β protein was determined.RESULTS High fat diet for 8 wk induced obesity and insulin resistance evident by increases in body weight and impaired glucose tolerance. By performing quantitative real-time polymerase chain reaction, we found that high fat diet triggered the expression of retinal endoplasmic reticulum-stress markers(P < 0.05). These effects were associated with increased thioredoxin interacting protein and decreased mi R-17-5p expression, whichwere restored by inhibiting endoplasmic reticulumstress with PBA(P < 0.05). In vitro, palmitate-BSA triggered endoplasmic reticulum-stress markers, which was accompanied with reduced mi R-17-5p and induced thioredoxin interacting protein m RNA in retinal Müller glial cell line(P < 0.05). Palmitate upregulated NLRP3 and IL1β expression in primary Müller cells isolated from wild type. However, using primary Müller cells isolated from thioredoxin interacting protein knock-out mice abolished palmitate-mediated increase in NLRP3 and IL1β.CONCLUSION Our work suggests that targeting endoplasmic reticulumstress or thioredoxin interacting protein are potential therapeutic strategies for early intervention of obesityinduced retinal inflammation.
文摘This paper presents a constitutive framework for finite element analysis of the truck beam end cutting process.For this purpose,a finite strain anisotropic elasto-plastic model,which takes nonlinear kinematic and isotropic hardening into account,is presented.Three factors are investigated to determine the effect on cutting quality:radius of cutting tools,strength of materials and relative clearance in cutting.The recommendations made herein are based on the simulation results.
基金sponsored by the 2016 Research Program on Educational Reform of Undergraduate Institutions in Shandong Province,namely "Research and Practice on the Mode of Training for Engineering Leading Talents Facing the Demand for High-end Talents in the Industry"(B2016M016),"Exploration and Practice of Promoting the Teaching Reform and Innovation Mode of Higher Education Based on Massive Open Online Course (MOOC)"(B2016Z018) and "Research and Application of Blended Teaching Mode Based on ‘ MOOC + SPOCs + Flipped Classroom’"(B2016Z020)supported by "Research on Multi-dimensional Education Quality Evaluation System Facing the Training of Postgraduate with Professional Degree (SDYZ1603)",which was the 2016 special project of undergraduate education innovation plan for Shandong Province,and "Research and Practice on the Mode of Training for Full Stack Talents for Internet of Things"(BK201602),which was the teaching and research project of Harbin Institute of Technology,Weihai
文摘The paper illustrates the reason of the lack of talents with outstanding innovative practice ability and engineering leadership has become a great obstacle for many industries, represented by the software industry, to develop along with the new era, and restricted the evolution of these industries toward the high end. With the target of training talents with innovation capacity and engineering leadership, the training plan for top talents based on the demand for high-end talents in the software engineering industry is put forward, and analyses are given on significant aspects including the development of the training resource system, the screening of students and the selection of enterprises, the teaching staff construction for university-enterprise cooperation, the establishment of a management system with joint effort for talents development, and the construction of process quality guarantee mechanism. In the end, for the implementation of the training plan, it is pointed out that the university-enterprise cooperative development mechanism should be perfected, the talents development practice should be enhanced, the personalized training of students should be emphasized, and the innovative ability in practice and the engineering leadership of students should be practically improved.
基金Supported by the National Natural Science Foundation of Chana(Nos. 29804002, 20274006) and Tianjin Polytechnic Univer-sity Item(Nos. 029307, 029302).
文摘Novel stable high-spin molecules possessing three different arranging fashions were designed with —^＊N—S— as a spin-containing （SC） fragment, an aromatic group, such as benzene （ 1 ）, pyridine （2）, pyridazine （3） , pyrimidine （4）, pyrazine （5） or triazine （6） as end groups （EG）, and phenyl as a ferromagnetic coupling （FC） unit. The effects of different EG on the spin multiplicities of the ground states and their stabilities were investigated by means of the AM1-CI approach. All the investigated molecules corresponded to the FC and possessed high-spin ground states. The spin on the two atoms of the SC fragment was not in agreement with the delocalization results in the specific stability of —^＊N—S—. In those molecules, the stabilities of the triplet states decreased when the distance between the atoms of central SC fragments （—N—） increased. The stabilities of the triplet states of compounds 1a-n, 1b-n and 1c-n, with heterocycles as EG were higher than those of the triplet states of those compounds with phenyl as EG. Furthermore, the stahilities of the triplet states of the compounds with pyrimidine and triazine as EG were higher than those with pyridine, pyridazine or pyrasine as EG.
文摘Milling Process Simulation is one of the important re search areas in manufacturing science. For the purpose of improving the prec ision of simulation and extending its usability, numerical algorithm is more and more used in the milling modeling areas. But simulative efficiency is decreasin g with increase of its complexity. As a result, application of the method is lim ited. Aimed at above question, high-efficient algorithm for milling process sim ulation is studied. It is important for milling process simulation’s applicatio n. Parallel computing is widely used to solve the large-scale computation question s. Its advantages include system flexibility, robust, high-efficient computing capability and high ratio of performance to price. With the development of compu ter network, utilizing the computing resource in the Internet, a virtual computi ng environment with powerful computing capability can be consisted by microc omputers, and the difficulty of building hardware environment which is used to s upport parallel computing is reduced. How to use network technology and parallel algorithm to improve simulative effic iency for milling forces simulation is investigated in the paper. In order to pr edict milling forces, a simplified local milling forces model is used in the pap er. End milling cutter is assumed to be divided by r number of differential elem ents along the axial direction of the cutter. For a given time, the total cuttin g forces can be obtained by summarizing the resultant cutting force produced by each differential cutter disc. Divide the whole simulative time into some segmen ts, send these program’s segments to microcomputers in the Internet and obtain the result of the program’s segments, all of the result of program’s segments a re composed the final result. For implementing the algorithm, a distributed Parallel computing framework is de signed in the paper. In the framework, web server plays a role of controller. Us ing Java RMI(remote method interface), the computing processes in computing serv er are called by web server. There are lots of control processes in web server a nd control the computing servers. The codes of simulative algorithm can be dynam ic sent to the computing servers, and milling forces at the different time are c omputed through utilizing the local computer’s resource. The results that are ca lculated by every computing servers are sent to the web server, and composed the final result. The framework can be used by different simulative algorithm. Comp ared with the algorithm running single machine, the efficiency of provided algor ithm is higher than that of single machine.
文摘We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.
文摘目的探究血清晚期糖基化终产物受体(RAGE)、高迁移率族蛋白B1(high mobility group protein B1,HMGB1)水平与重症肺炎(SP)急性呼吸窘迫综合征(ARDS)发病及γ-干扰素(IFN-γ)/白细胞介素4(IL-4)变化的关系。方法前瞻性选取2020年3月至2022年2月我院收治的100例SP患儿为研究对象,根据患儿是否发生继发性ARDS将患儿分为ARDS组(n=56)和对照组(n=44),收集患儿一般资料,采集外周血以酶联免疫吸附法进行RAGE、HMGB1、IFN-γ和IL-4表达水平检测,采用多因素logistic回归分析SP患儿继发ARDS的影响因素,采用Pearson相关性分析其与IFN-γ/IL-4的相关性,并采用受试者工作曲线(ROC)分析RAGE、HMGB1表达对SP患儿继发ARDS的预测价值。结果两组SP患儿性别、年龄、体温以及发病季节之间无显著差异,ARDS组致病菌种类多于对照组,PaO_(2)/FiO_(2)和APS评分、血清RAGE、HMGB1、IFN-γ和IL-4表达水平以及IFN-γ/IL-4比值均高于对照组(P<0.05)。经多因素logistic回归分析可知,致病菌种类、PaO_(2)/FiO_(2)、RAGE、HMGB1表达、IFN-γ、IL-4和IFN-γ/IL-4均为SP患儿继发ARDS的影响因素。经Pearson相关检验,SP患儿血清RAGE、HMGB1表达水平与IFN-γ、IL-4和IFN-γ/IL-4均呈正相关(P<0.05)。经ROC曲线分析可得,血清RAGE、HMGB1水平预测SP患儿发生ARDS的AUC分别为0.707和0.750,灵敏度分别为73.2%、64.3%,特异度分别为68.2%、77.3%,两者联合预测的AUC为0.848,灵敏度和特异度分别为80.4%和81.8%。结论SP继发ARDS患儿血清中RAGE、HMGB1表达水平较高,与IFN-γ/IL-4呈正相关,监测患儿血清RAGE、HMGB1表达对SP患儿继发ARDS的风险有一定的预测价值。
基金supported by the National Key Research and Development Program of China(2017YFA0603804)the National Natural Science Foundation of China(41831174 and 41430528)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX19_1026)Guwei ZHANG was supported by the China Scholarship Council(NO.201908320503)。
文摘Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.
文摘A series of perovskite-like mixed oxides La2-xSrxMO4±λ(M =Cu, Co,Ni; x=0,1 ) was prepared and characterized using X-ray powder diffraction. The catalytic properties of these catalysts in NO decompositiori were tested. The results showed that LaSrNiO4-λ with K2NiF4 structure is very active and stable for the decomposition of NO.
文摘Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.
文摘AIM:To evaluate the serum levels of endozepine-4,their relation with ammonia serum levels,the grading of coma and the severity of cirrhosis,in patients with hepatic coma. METHODS:In this study we included 20 subjects with Hepatic coma,20 subjects with minimal hepatic encephalopathy(MHE) and 20 subjects control. All subjects underwent blood analysis,Child Pugh and Model for End- stage liver disease(MELD) assessment,endozepine-4 analysis. RESULTS:Subjects with hepatic coma showed significant difference in endozepine-4(P < 0.001) and NH3 levels(P < 0.001) compared both to MHE and controls patients. Between NH3 and endozepine-4 we observed a significant correlation(P = 0.009; Pearson correlation 0.570). There was a significant correlation between endozepine-4 and MELD(P = 0.017; Pearsoncorrelation = 0.529). In our study blood ammonia concentration was noted to be raised in patients with hepatic coma,with the highest ammonia levels being found in those who were comatose. We also found a high correlation between endozepine-4 and ammonia(P < 0.001). In patients with grade Ⅳ hepatic coma,endozepine levels were significantly higher compared to other groups. CONCLUSION:This study suggests that an increased level of endozepine in subjects with higher levels of MELD was observed. In conclusion,data concerning involvement of the GABA-ergic system in HE coma could be explained by stage-specific alterations.
基金supported by the Program for Changjiang Scholars and Innovative Research Team in University(IRT1294)the China National Science and Technology Major Projects(Grant No:2016ZX05011)
文摘Layer regrouping is to divide all the layers into several sets of production series according to the physical properties and recovery percent of layers at high water-cut stage, which is an important technique to improve oil recovery for high water-cut multilayered reservoirs. Dif- ferent regroup scenarios may lead to different production performances. Based on unstable oil-water flow theory, a multilayer commingled reservoir simulator is established by modifying the production split method. Taking into account the differences of layer properties, including per- meability, oil viscosity, and remaining oil saturation, the pseudo flow resistance contrast is proposed to serve as a characteristic index of layer regrouping for high water-cut multilayered reservoirs. The production indices of multi- layered reservoirs with different pseudo flow resistances are predicted with the established model in which the data are taken from the Shengtuo Oilfield. Simulation results show that the pseudo flow resistance contrast should be less than 4 when the layer regrouping is implemented. The K-means clustering method, which is based on the objec- tive function, is used to automatically carry out the layer regrouping process according to pseudo flow resistances. The research result is applied to the IV-VI sand groups of the second member of the Shahejie Formation in the Shengtuo Oilfield, a favorable development performance is obtained, and the oil recovery is enhanced by 6.08 %.
文摘A highly efficient and convenient procedure for the enantioselective synthesis of (S)-Rivastigmine, a cholinergic agent for the treatment of mild to moderate dementia of the Alzheimer’s type and dementia due to Parkinson’s disease, is accomplished by the treatment of versatile, readily accessible (S)-(-)-2-methyl-2-propanesulfinamide with 3-hydroxyacetophenone. This protocol provides high yield and excellent enantiomeric excess in short step synthesis.
基金Funded by the National Basic Research Program of China(No.2009CB724401)the Major Science and Technology Program of High-end CNC Machine Tools and Basic Manufacturing Equipment(No.2012ZX04003-041)
文摘The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.
