A half-size prototype of the multi wire drift chamber for the cooling storage ring external-target experiment(CEE)was assembled and tested in the 350 MeV/u Kr+Fe reactions at the heavy-ion research facility in Lanzhou...A half-size prototype of the multi wire drift chamber for the cooling storage ring external-target experiment(CEE)was assembled and tested in the 350 MeV/u Kr+Fe reactions at the heavy-ion research facility in Lanzhou.The prototype consists of six sense layers,where the sense wires are stretched in three directions X,U,and V;meeting 0?,30?,and-30?,respectively,with respect to the vertical axis.The sensitive area of the prototype is 76 cm×76 cm.The amplified and shaped signals from the anode wires were digitized in a serial capacity array.When operating at a high voltage of 1500 V on the anode wires,the efficiency for each layer is greater than 95%.The tracking residual is approximately 301±2μm.This performance satisfies the requirements of CEE.展开更多
BACKGROUND： Studies have demonstrated that experimental autoimmune encephalomyelitis （EAE） onset correlates with increased interferon-v （IFN-γ） and tumor necrosis factor-α （TNF-α） expression. Oxymatrine （OM...BACKGROUND： Studies have demonstrated that experimental autoimmune encephalomyelitis （EAE） onset correlates with increased interferon-v （IFN-γ） and tumor necrosis factor-α （TNF-α） expression. Oxymatrine （OM） has been shown to inhibit autoimmune responses, but there are no reports showing that it could prevent the development of EAE. OBJECTIVE： To observe the effect of OM on serum levels of IFN-γ and TNF-α in a rat model of EAE.DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Experimental Animal Center of Henan Academy of Chinese Medicine and at the Key Disciplines Laboratory Clinical Medicine of Henan Province between July and December 2008. MATERIALS： OM was purchased from Chia-tai Tianqing Pharmaceutical, China; complete Freund＇s adjuvant was purchased from Sigma, USA. METHODS： Forty female Wistar rats were randomly assigned to four groups： EAE model （M）, low-dose OM treatment （OM-L）, high-dose OM treatment （OM-H）, and normal control （N, no immunization）, with 10 rats in each group. EAE was established in the M, OM-L, and OM-H groups following immunization with Guinea pig spinal cord homogenate and complete Freund＇s adjuvant. The M and N groups were intraperitoneally injected with normal saline （6.7 mL/kg per day）, the OM-L group received an intraperitoneal injection of OM （100 mg/kg per day）, and the OM-H group received OM （150 mg/kg per day）. MAIN OUTCOME MEASURES： At 16 days after immunization, the degree of histopathological changes in the spinal cord was assessed by hematoxylin-eosin stanining. Enzyme-linked immunosorbent assay was used to detect serum levels of IFN-γ, and radioimmunoassay was utilized to determine serum TNF-α level. Neurological scores were measured on a daily basis according to a 0-5 scale. RESULTS： Daily injections of OM, both high and low doses, resulted in decreased neurological scores in EAE rats （P〈0.01）, as well as reduced cellular infiltration in the spinal cord and decreased levels of serum IFN-γ and TNF-α （P〈 0.01）. CONCLUSION： OM reduced the onset and severity of EAE, which correlated with decreased IFN-γ and TNF-α expression.展开更多
To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to...To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to predict the metal flow in radial direction, by which the whole multi-stage forming process could be simulated in axisymmetric and integral way. The result shows that the axisymmetric simulation method was an effective method to explore the metal flow in radial direction and to analyze the relationships of tools motion during the wheel rolling. The detail information about metal flow in railway wheel forming process was obtained. The metal in the wheel web was from the area near the half radius of the original billet; the chill zone of the billet became an envelope of the rim and part of the web with a maximum thickness of about 6 mm below the tread. At the wheel rolling stage, the metal in the rim flowed towards the web; the metal near the surfaces of the conjunction region between the web and rim suffered severe shear deformation.展开更多
Objective:The day surgery mode has significantly reduced preoperative waiting time for patients.However,this mode also led to brief and sometimes abrupt interactions between patients with vision loss and nursing staff...Objective:The day surgery mode has significantly reduced preoperative waiting time for patients.However,this mode also led to brief and sometimes abrupt interactions between patients with vision loss and nursing staff during the preoperative visits.Additionally,patients may experience negative emotions.The aim of this study was to describe the preoperative experiences and identify related stressful factors among patients waiting vitreo-retinal day surgery.Methods:This study was guided by an interpretive approach.Semi-structured,face-to-face,in-depth interviews were conducted with patients from August 2021 to October 2024.Inductive content analysis and research software were used to analyze the data.Results:Twenty-seven patients agreed to participate the interviews.Their ages ranged from 19 to 70 years old.The waiting time before hospitalization varied from 7 to 90 days.Three main categories emerged from patients’complaints:day surgery procedures,concerns about eye conditions and supports.Conclusions:The findings underscore the importance of preoperative care services.It is suggested that providing accurate preoperative information and effective support can significantly enhance the quality of preoperative care service.展开更多
This article attempts to develop a simultaneous optimization procedure of several response variables from incomplete multi-response experiments. In incomplete multi-response experiments all the responses (p) are not r...This article attempts to develop a simultaneous optimization procedure of several response variables from incomplete multi-response experiments. In incomplete multi-response experiments all the responses (p) are not recorded from all the experimental units (n). Two situations of multi-response experiments considered are (i) on units all the responses are recorded while on units a subset of responses is recorded and (ii) on units all the responses (p) are recorded, on units a subset of responses is recorded and on units the remaining subset of responses is recorded. The procedure of estimation of parameters from linear multi-response models for incomplete multi-response experiments has been developed for both the situations. It has been shown that the parameter estimates are consistent and asymptotically unbiased. Using these parameter estimates, simultaneous optimization of incomplete multi-response experiments is attempted following the generalized distance criterion [1]. For the implementation of these procedures, SAS codes have been developed for both complete (k ≤ 5, p = 5) and incomplete (k ≤ 5, p1 = 2, 3 and p2 = 2, 3, where k is the number of factors) multi-response experiments. The procedure developed is illustrated with the help of a real data set.展开更多
The subsidence dolines are the most common surface forms of the concealed karsts.One type of these dolines is the suffosion doline.In this model experiment the influential role of these kind of dolines’development fa...The subsidence dolines are the most common surface forms of the concealed karsts.One type of these dolines is the suffosion doline.In this model experiment the influential role of these kind of dolines’development factors were analyzed.The aim of the study was to determine the significance of the parameters(cover thickness,secondary porosity of the bedrock,chimney diameter,grain size)that influence the development of a suffosion doline.To study the influencing factors numerous(162)experiments were made with different parameters,in a manner that during the experiments we changed only one parameter,so the effects of it would be detectable from the final solution.These measurements were made with the use of a special tool,designed and built for this purpose.According to the data we gained from the model experiments,the development of a suffosion doline is influenced by many parameters.If these parameters are in an optimal connection to each other,a suffosion doline may appear on the surface.Knowing these parameters of the covered karstic depressions lets us estimate other parameters that may influence the development of the subsidence dolines.展开更多
The electricity cost of agricultural irrigation and drainage in the Dahe Ex- periment Station was analyzed. The results showed that from 2012 to 2016, the annual total power and total electricity cost increased year b...The electricity cost of agricultural irrigation and drainage in the Dahe Ex- periment Station was analyzed. The results showed that from 2012 to 2016, the annual total power and total electricity cost increased year by year. The higher the electricity consumption was, the lower the factor adjusted power price was. The an- nual factor adjusted power price decreased from 532.5 yuan （above the national standard） to -599.78 yuan （below the national standard）. The electricity consumption was always highest in June. The more the rainfall from June to September was, the less the monthly electricity usage was. The collect electricity charge to total electricity charge ratio was 1.26%-1.34%, the directory electricity charge to total electricity charge ratio was 96.34%-99.80%, and the electricity loss of transformer was 288-496 kW/h.展开更多
Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is constructed in a seismically active region. The model experiment is performed on an underwater shaking t...Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is constructed in a seismically active region. The model experiment is performed on an underwater shaking table to simulate the response of submarine pipelines under dynamic input. In consideration of the effects of the terrestrial and submarine pipeline, water depth, support condition, distance from seabed, empty and full pipeline, and span on dynamic response, 120 groups of experiments are conducted. Affecting factors are analyzed and conclusions are drawn for reference. For the control of dynamic response, the span of a submarine pipeline is by far more important than the other factors. Meanwhile, the rosponse difference between a submarine pipeline under sine excitation and that under random excitation exists in experiments.展开更多
Leaching is an important way of separation of trace elements from coal. Based on leaching experiments, the content of trace elements separated out from coal is related to their existing state and content in coal, the ...Leaching is an important way of separation of trace elements from coal. Based on leaching experiments, the content of trace elements separated out from coal is related to their existing state and content in coal, the duration of leaching process, temperature of leaching liquor and its acidity and basicity. The higher the temperature of leaching liquor and the longer the leaching time, the higher the contents of separated trace elements will be. In the course of leaching, the pH values of leaching liquors change and different trace elements are affected differently by the pH values.展开更多
Rapid advances in deep-sea mining engineering have created an urgent need for the accurate evaluation of the undrained strength of marine soils,especially surface soils.Significant achievements have been made using fu...Rapid advances in deep-sea mining engineering have created an urgent need for the accurate evaluation of the undrained strength of marine soils,especially surface soils.Significant achievements have been made using full-flow penetration penetrometers to evaluate marine soil strength in the deep penetration;however,a method considering the effect of ambient water on the surface penetration needs to be established urgently.In this study,penetrometers with multiple probes were developed and used to conduct centrifuge experiments on South China Sea soil and kaolin clay.First,the forces on the probes throughout the penetration process were systematically analyzed and quantified.Second,the spatial influence zone was determined by capturing the resistance changes and sample crack development,and the penetration depth for a sample to reach a stable failure mode was given.Third,the vane shear strength was used to invert the penetration resistance factor of the ball and determine the range of the penetration resistance factor values.Furthermore,a methodology to determine the penetration resistance factors for surface marine soils was established.Finally,the effect of the water cavity above various probes in the surface penetration was used to formulate an internal mechanism for variations in the penetration resistance factor.展开更多
Purpose: The aim of this study was to illuminate the connotation of “dilemma” regarding the use of physical restraint on elderly patients as represented by female nurses working in general wards at community hospita...Purpose: The aim of this study was to illuminate the connotation of “dilemma” regarding the use of physical restraint on elderly patients as represented by female nurses working in general wards at community hospitals who also live with elderly adults at home. Method: The study used the questionnaire method with an independently prepared questionnaire. Participants: The objective of the study was explained to the persons in charge of nursing in the selected 17 hospitals, and 1929. Finally, this study of participants were 524 female nurses working in general 54 wards (excluding the emergency wards of psychiatry, pediatrics, obstetrics, outpatients, operating rooms, and intensive care units) at community hospitals who also live with elderly adults at home. Results and conclusions: Cronbach’s overall coefficient for the 20 items of dilemma was high (0.78) and the factor analysis extracted four dilemma factors as having a characteristic value of 1 (Kaiser-Meyer-Olkin measure value = 0.81) with a cumulative contribution ratio of 64.5%. The high Cronbach’s for these items (0.86, 0.88, 0.87 and 0.81) confirmed the internal consistencies. With respect to the dilemma where nurses working in general wards at community hospitals who also live with elderly adults at home are faced with the physical restraint of elderly persons, four factors in the clarification of the dilemma were extracted: accomplishment of medical-treatment and accident prevention, characteristic features in nursing for elderly patients with dementia, healthcare professional relationship in nursing for elderly patients with dementia, and priorities on the accident prevention for elderly patients with dementia. Therefore, the construction of four systems to cope with these dilemmas is suggested. These systems would enable practising nurses to: (i) institution of policies to encourage discussion between nurses and other medical staff to reach consensus on treatment;(ii) allocating elderly care specialists to wards to promote alternatives to restraints;(iii) establishment of safety standards to define nurses’ responsibilities;and (iv) institution of continuous ethical education for nurses.展开更多
In the present study,a facility,i.e.,a mechanical deflection system (MDS),was established and applied to assess the long-term reliability of the solder joints in plastic ball grid array (BGA) assembly.It was found tha...In the present study,a facility,i.e.,a mechanical deflection system (MDS),was established and applied to assess the long-term reliability of the solder joints in plastic ball grid array (BGA) assembly.It was found that the MDS not only quickly assesses the long-term reliability of solder joints within days,but can also mimic similar failure mechanisms in accelerated thermal cycling (ATC) tests. Based on the MDS and ATC reliability experiments,the acceleration factors (AF) were obtained for different reliability testing conditions.Furthermore,by using the creep constitutive relation and fatigue life model developed in part I,a numerical approach was established for the purpose of virtual life prediction of solder joints. The simulation results were found to be in good agreement with the test results from the MDS.As a result,a new reliability assessment methodology was established as an alternative to ATC for the evaluation of long-term reliability of plastic BGA assembly.展开更多
The effects of gravity,capillary force,and viscous force on the migration characteristics of oil and gas interface in oxygen-reduced air-assisted gravity drainage(OAGD)were studied through a two-dimensional visualizat...The effects of gravity,capillary force,and viscous force on the migration characteristics of oil and gas interface in oxygen-reduced air-assisted gravity drainage(OAGD)were studied through a two-dimensional visualization model.The effects of bond number,capillary number and low-temperature oxidation on OAGD recovery were studied by long core displacement experiments.On this basis,the low-temperature oxidation number was introduced and its relationship with the OAGD recovery was established.The results show that the shape and changing law of oil and gas front are mainly influenced by gravity,capillary force and viscous force.When the bond number is constant(4.52×10-4),the shape of oil-gas front is controlled by capillary number.When the capillary number is less than 1.68×10-3,the oil and gas interface is stable.When the capillary number is greater than 2.69×10-2,the oil and gas interface shows viscous fingering.When the capillary number is between 1.68×10-3 and 2.69×10-2,the oil and gas interface becomes capillary fingering.The core flooding experiments results show that for OAGD stable flooding,before the gas breakthrough,higher recovery is obtained in higher gravity number and lower capillary number.In this stage,gravity is predominant in controlling OAGD recovery and the oil recovery could be improved by reducing injection velocity.After gas breakthrough,higher recovery was obtained in lower gravity and higher capillary numbers,which means that the viscous force had a significant influence on the recovery.Increasing gas injection velocity in this stage is an effective measure to improve oil recovery.The low-temperature oxidation number has a good correlation with the recovery and can be used to predict the OAGD recovery.展开更多
For multi-agent reinforcement learning in Markov games, knowledge extraction and sharing are key research problems. State list extracting means to calculate the optimal shared state path from state trajectories with c...For multi-agent reinforcement learning in Markov games, knowledge extraction and sharing are key research problems. State list extracting means to calculate the optimal shared state path from state trajectories with cycles. A state list extracting algorithm checks cyclic state lists of a current state in the state trajectory, condensing the optimal action set of the current state. By reinforcing the optimal action selected, the action policy of cyclic states is optimized gradually. The state list extracting is repeatedly learned and used as the experience knowledge which is shared by teams. Agents speed up the rate of convergence by experience sharing. Competition games of preys and predators are used for the experiments. The results of experiments prove that the proposed algorithms overcome the lack of experience in the initial stage, speed up learning and improve the performance.展开更多
BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study s...BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.展开更多
Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese ...Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods： In total, 178 infertile patients with azoospermia （nonobstructed）, 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array （MASA） technology. Results： Of the 312 patients, 36 （11.5%） were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% （25/178） in the azoospermia group and 8.2% （11/134） in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion： There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.展开更多
The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multip...The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in China. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors （paleo-anticline, source rock, regional cap rock and kinematic equilibrium belt） controlling hydrocarbon accumulation, this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration ofoil and gas in the Silurian of the Tarim basin.展开更多
Heavy-equipment airdrop is a highly risky procedure that has a complicated system due to the secluded and complex nature of factors＇ coupling. As a result, it is difficult to study the modeling and safety simulation ...Heavy-equipment airdrop is a highly risky procedure that has a complicated system due to the secluded and complex nature of factors＇ coupling. As a result, it is difficult to study the modeling and safety simulation of this system. The dynamic model of the heavy-equipment airdrop is based on the Lagrange analytical mechanics, which has all the degrees of freedom and can accurately pinpoint the real-time coordinates and attitude of the carrier with its cargo. Unfavorable conditions accounted in the factors＇ models, including aircraft malfunctions and adverse environments, are established from a man-machine-environment perspective. Subsequently, a virtual simulation system for the safety research of the multi-factor coupling heavy-equipment airdrop is developed through MATLAB/Simulink, C language and Flightgear software. To verify the veracity of the theory, the verification model is built based on dynamic software ADAMS. Finally, the emulation is put to the test with the input of realistic accident variables to ascertain its feasibility and validity of this method.展开更多
Objective To investigate the patients experience in community health centers( CHCs) and explore its associated factors. Methods A cross-sectional study was conducted among 330 patients who visited CHCs in Shenzhen,Chi...Objective To investigate the patients experience in community health centers( CHCs) and explore its associated factors. Methods A cross-sectional study was conducted among 330 patients who visited CHCs in Shenzhen,China from January to March 2018. Dependent variable was patient experience. Key descriptive variables were age,gender,marital status,working status groups,visits frequency for the past 6 months,whether patients had signed a family doctor,whether trusted in family doctor,whether had chronic diseases. Results Questionnaires for 300 patients were assessed. In the univariate analysis,patients experience total score was significantly associated with marital status( P < 0. 1),working status groups( P < 0. 1),frequency of visit for the past 6 months( P < 0. 05),whether had signed a family doctor( P < 0. 05),whether trusted in family doctor( P < 0. 05),whether had chronic diseases( P < 0. 05). The multivariate analysis showed that unmarried patients( P = 0. 011,OR = 2. 96,95% CI: 1. 24-5. 43) and had signed a family doctor( P = 0. 023,OR = 0. 44,95% CI: 0. 22-0. 85) were more likely to get a higher score. Conclusions Findings of this study showed a medium-level score of patients experience in the community. Patients had a quite good experience and more interventions should be focused upon the influence factors to improve patients experience.展开更多
Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the applic...Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the application of the technology in quality test of Yongjiang river submarine tunnel tube foundation in the paper. The material of the model was got from on the spot. The successful test has been made with results of the model experiment.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11927901,11875301,11875302,U1867214,U1832105,U1832167)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB34000000)+2 种基金the National Key R&D Program of China(No.2018YFE0205200)the CAS"Light of West China"Programthe Tsinghua University Initiative Scientific Research Program。
文摘A half-size prototype of the multi wire drift chamber for the cooling storage ring external-target experiment(CEE)was assembled and tested in the 350 MeV/u Kr+Fe reactions at the heavy-ion research facility in Lanzhou.The prototype consists of six sense layers,where the sense wires are stretched in three directions X,U,and V;meeting 0?,30?,and-30?,respectively,with respect to the vertical axis.The sensitive area of the prototype is 76 cm×76 cm.The amplified and shaped signals from the anode wires were digitized in a serial capacity array.When operating at a high voltage of 1500 V on the anode wires,the efficiency for each layer is greater than 95%.The tracking residual is approximately 301±2μm.This performance satisfies the requirements of CEE.
基金a Grant from the Natural Scientific Research Project of the Education Department of Henan Province,No. 2009A350009
文摘BACKGROUND： Studies have demonstrated that experimental autoimmune encephalomyelitis （EAE） onset correlates with increased interferon-v （IFN-γ） and tumor necrosis factor-α （TNF-α） expression. Oxymatrine （OM） has been shown to inhibit autoimmune responses, but there are no reports showing that it could prevent the development of EAE. OBJECTIVE： To observe the effect of OM on serum levels of IFN-γ and TNF-α in a rat model of EAE.DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Experimental Animal Center of Henan Academy of Chinese Medicine and at the Key Disciplines Laboratory Clinical Medicine of Henan Province between July and December 2008. MATERIALS： OM was purchased from Chia-tai Tianqing Pharmaceutical, China; complete Freund＇s adjuvant was purchased from Sigma, USA. METHODS： Forty female Wistar rats were randomly assigned to four groups： EAE model （M）, low-dose OM treatment （OM-L）, high-dose OM treatment （OM-H）, and normal control （N, no immunization）, with 10 rats in each group. EAE was established in the M, OM-L, and OM-H groups following immunization with Guinea pig spinal cord homogenate and complete Freund＇s adjuvant. The M and N groups were intraperitoneally injected with normal saline （6.7 mL/kg per day）, the OM-L group received an intraperitoneal injection of OM （100 mg/kg per day）, and the OM-H group received OM （150 mg/kg per day）. MAIN OUTCOME MEASURES： At 16 days after immunization, the degree of histopathological changes in the spinal cord was assessed by hematoxylin-eosin stanining. Enzyme-linked immunosorbent assay was used to detect serum levels of IFN-γ, and radioimmunoassay was utilized to determine serum TNF-α level. Neurological scores were measured on a daily basis according to a 0-5 scale. RESULTS： Daily injections of OM, both high and low doses, resulted in decreased neurological scores in EAE rats （P〈0.01）, as well as reduced cellular infiltration in the spinal cord and decreased levels of serum IFN-γ and TNF-α （P〈 0.01）. CONCLUSION： OM reduced the onset and severity of EAE, which correlated with decreased IFN-γ and TNF-α expression.
基金Sponsored by National High-tech Research and Development Program(863 Program)of China(2008AA030703)
文摘To investigate the metal flow during the railway wheel forming process, experiments and finite element method （FEM） simulation were carried out. An axisymmetric modeling for the wheel rolling process was proposed to predict the metal flow in radial direction, by which the whole multi-stage forming process could be simulated in axisymmetric and integral way. The result shows that the axisymmetric simulation method was an effective method to explore the metal flow in radial direction and to analyze the relationships of tools motion during the wheel rolling. The detail information about metal flow in railway wheel forming process was obtained. The metal in the wheel web was from the area near the half radius of the original billet; the chill zone of the billet became an envelope of the rim and part of the web with a maximum thickness of about 6 mm below the tread. At the wheel rolling stage, the metal in the rim flowed towards the web; the metal near the surfaces of the conjunction region between the web and rim suffered severe shear deformation.
基金supported by the Nursing Innovation and Development Research Project of the Lingnan Nightingale Nursing Research Institute and Nursing Association,Guangdong Province(GDHLYJYB202403,GDHLYJYM202417)Research Project on Party Building Theory and Practice at Zhongshan Ophthalmic Center in 2024,Research Project on Standardized Management of Day Medical Services by the Institute of Hospital Management,National Health Commission(DSQ20251016)Medical Science and Technology Foundation of Guangdong Province(A2021088).
文摘Objective:The day surgery mode has significantly reduced preoperative waiting time for patients.However,this mode also led to brief and sometimes abrupt interactions between patients with vision loss and nursing staff during the preoperative visits.Additionally,patients may experience negative emotions.The aim of this study was to describe the preoperative experiences and identify related stressful factors among patients waiting vitreo-retinal day surgery.Methods:This study was guided by an interpretive approach.Semi-structured,face-to-face,in-depth interviews were conducted with patients from August 2021 to October 2024.Inductive content analysis and research software were used to analyze the data.Results:Twenty-seven patients agreed to participate the interviews.Their ages ranged from 19 to 70 years old.The waiting time before hospitalization varied from 7 to 90 days.Three main categories emerged from patients’complaints:day surgery procedures,concerns about eye conditions and supports.Conclusions:The findings underscore the importance of preoperative care services.It is suggested that providing accurate preoperative information and effective support can significantly enhance the quality of preoperative care service.
文摘This article attempts to develop a simultaneous optimization procedure of several response variables from incomplete multi-response experiments. In incomplete multi-response experiments all the responses (p) are not recorded from all the experimental units (n). Two situations of multi-response experiments considered are (i) on units all the responses are recorded while on units a subset of responses is recorded and (ii) on units all the responses (p) are recorded, on units a subset of responses is recorded and on units the remaining subset of responses is recorded. The procedure of estimation of parameters from linear multi-response models for incomplete multi-response experiments has been developed for both the situations. It has been shown that the parameter estimates are consistent and asymptotically unbiased. Using these parameter estimates, simultaneous optimization of incomplete multi-response experiments is attempted following the generalized distance criterion [1]. For the implementation of these procedures, SAS codes have been developed for both complete (k ≤ 5, p = 5) and incomplete (k ≤ 5, p1 = 2, 3 and p2 = 2, 3, where k is the number of factors) multi-response experiments. The procedure developed is illustrated with the help of a real data set.
文摘The subsidence dolines are the most common surface forms of the concealed karsts.One type of these dolines is the suffosion doline.In this model experiment the influential role of these kind of dolines’development factors were analyzed.The aim of the study was to determine the significance of the parameters(cover thickness,secondary porosity of the bedrock,chimney diameter,grain size)that influence the development of a suffosion doline.To study the influencing factors numerous(162)experiments were made with different parameters,in a manner that during the experiments we changed only one parameter,so the effects of it would be detectable from the final solution.These measurements were made with the use of a special tool,designed and built for this purpose.According to the data we gained from the model experiments,the development of a suffosion doline is influenced by many parameters.If these parameters are in an optimal connection to each other,a suffosion doline may appear on the surface.Knowing these parameters of the covered karstic depressions lets us estimate other parameters that may influence the development of the subsidence dolines.
文摘The electricity cost of agricultural irrigation and drainage in the Dahe Ex- periment Station was analyzed. The results showed that from 2012 to 2016, the annual total power and total electricity cost increased year by year. The higher the electricity consumption was, the lower the factor adjusted power price was. The an- nual factor adjusted power price decreased from 532.5 yuan （above the national standard） to -599.78 yuan （below the national standard）. The electricity consumption was always highest in June. The more the rainfall from June to September was, the less the monthly electricity usage was. The collect electricity charge to total electricity charge ratio was 1.26%-1.34%, the directory electricity charge to total electricity charge ratio was 96.34%-99.80%, and the electricity loss of transformer was 288-496 kW/h.
基金This research is financially supported by the Science and Technology Foundation of Liaoning Province (Grant No.972240)
文摘Seismic load has a significant effect on the response of a free spanning submarine pipeline when the pipeline is constructed in a seismically active region. The model experiment is performed on an underwater shaking table to simulate the response of submarine pipelines under dynamic input. In consideration of the effects of the terrestrial and submarine pipeline, water depth, support condition, distance from seabed, empty and full pipeline, and span on dynamic response, 120 groups of experiments are conducted. Affecting factors are analyzed and conclusions are drawn for reference. For the control of dynamic response, the span of a submarine pipeline is by far more important than the other factors. Meanwhile, the rosponse difference between a submarine pipeline under sine excitation and that under random excitation exists in experiments.
文摘Leaching is an important way of separation of trace elements from coal. Based on leaching experiments, the content of trace elements separated out from coal is related to their existing state and content in coal, the duration of leaching process, temperature of leaching liquor and its acidity and basicity. The higher the temperature of leaching liquor and the longer the leaching time, the higher the contents of separated trace elements will be. In the course of leaching, the pH values of leaching liquors change and different trace elements are affected differently by the pH values.
基金partially supported by the National Key Research and Development Program of China(No.2018YFC0309200)the National Natural Science Foundation of China(No.51879036)+1 种基金the LiaoNing Revitalization Talents Program(No.XLYC2002036)the Fundamental Research Funds for the Central Universities of Dalian University of Technology。
文摘Rapid advances in deep-sea mining engineering have created an urgent need for the accurate evaluation of the undrained strength of marine soils,especially surface soils.Significant achievements have been made using full-flow penetration penetrometers to evaluate marine soil strength in the deep penetration;however,a method considering the effect of ambient water on the surface penetration needs to be established urgently.In this study,penetrometers with multiple probes were developed and used to conduct centrifuge experiments on South China Sea soil and kaolin clay.First,the forces on the probes throughout the penetration process were systematically analyzed and quantified.Second,the spatial influence zone was determined by capturing the resistance changes and sample crack development,and the penetration depth for a sample to reach a stable failure mode was given.Third,the vane shear strength was used to invert the penetration resistance factor of the ball and determine the range of the penetration resistance factor values.Furthermore,a methodology to determine the penetration resistance factors for surface marine soils was established.Finally,the effect of the water cavity above various probes in the surface penetration was used to formulate an internal mechanism for variations in the penetration resistance factor.
文摘Purpose: The aim of this study was to illuminate the connotation of “dilemma” regarding the use of physical restraint on elderly patients as represented by female nurses working in general wards at community hospitals who also live with elderly adults at home. Method: The study used the questionnaire method with an independently prepared questionnaire. Participants: The objective of the study was explained to the persons in charge of nursing in the selected 17 hospitals, and 1929. Finally, this study of participants were 524 female nurses working in general 54 wards (excluding the emergency wards of psychiatry, pediatrics, obstetrics, outpatients, operating rooms, and intensive care units) at community hospitals who also live with elderly adults at home. Results and conclusions: Cronbach’s overall coefficient for the 20 items of dilemma was high (0.78) and the factor analysis extracted four dilemma factors as having a characteristic value of 1 (Kaiser-Meyer-Olkin measure value = 0.81) with a cumulative contribution ratio of 64.5%. The high Cronbach’s for these items (0.86, 0.88, 0.87 and 0.81) confirmed the internal consistencies. With respect to the dilemma where nurses working in general wards at community hospitals who also live with elderly adults at home are faced with the physical restraint of elderly persons, four factors in the clarification of the dilemma were extracted: accomplishment of medical-treatment and accident prevention, characteristic features in nursing for elderly patients with dementia, healthcare professional relationship in nursing for elderly patients with dementia, and priorities on the accident prevention for elderly patients with dementia. Therefore, the construction of four systems to cope with these dilemmas is suggested. These systems would enable practising nurses to: (i) institution of policies to encourage discussion between nurses and other medical staff to reach consensus on treatment;(ii) allocating elderly care specialists to wards to promote alternatives to restraints;(iii) establishment of safety standards to define nurses’ responsibilities;and (iv) institution of continuous ethical education for nurses.
基金The project supported by the National Natural Science Foundation of China (59705008)
文摘In the present study,a facility,i.e.,a mechanical deflection system (MDS),was established and applied to assess the long-term reliability of the solder joints in plastic ball grid array (BGA) assembly.It was found that the MDS not only quickly assesses the long-term reliability of solder joints within days,but can also mimic similar failure mechanisms in accelerated thermal cycling (ATC) tests. Based on the MDS and ATC reliability experiments,the acceleration factors (AF) were obtained for different reliability testing conditions.Furthermore,by using the creep constitutive relation and fatigue life model developed in part I,a numerical approach was established for the purpose of virtual life prediction of solder joints. The simulation results were found to be in good agreement with the test results from the MDS.As a result,a new reliability assessment methodology was established as an alternative to ATC for the evaluation of long-term reliability of plastic BGA assembly.
基金Supported by the National Science and Technology Major Project(ZX20170054)
文摘The effects of gravity,capillary force,and viscous force on the migration characteristics of oil and gas interface in oxygen-reduced air-assisted gravity drainage(OAGD)were studied through a two-dimensional visualization model.The effects of bond number,capillary number and low-temperature oxidation on OAGD recovery were studied by long core displacement experiments.On this basis,the low-temperature oxidation number was introduced and its relationship with the OAGD recovery was established.The results show that the shape and changing law of oil and gas front are mainly influenced by gravity,capillary force and viscous force.When the bond number is constant(4.52×10-4),the shape of oil-gas front is controlled by capillary number.When the capillary number is less than 1.68×10-3,the oil and gas interface is stable.When the capillary number is greater than 2.69×10-2,the oil and gas interface shows viscous fingering.When the capillary number is between 1.68×10-3 and 2.69×10-2,the oil and gas interface becomes capillary fingering.The core flooding experiments results show that for OAGD stable flooding,before the gas breakthrough,higher recovery is obtained in higher gravity number and lower capillary number.In this stage,gravity is predominant in controlling OAGD recovery and the oil recovery could be improved by reducing injection velocity.After gas breakthrough,higher recovery was obtained in lower gravity and higher capillary numbers,which means that the viscous force had a significant influence on the recovery.Increasing gas injection velocity in this stage is an effective measure to improve oil recovery.The low-temperature oxidation number has a good correlation with the recovery and can be used to predict the OAGD recovery.
基金supported by the National Natural Science Foundation of China (61070143 61173088)
文摘For multi-agent reinforcement learning in Markov games, knowledge extraction and sharing are key research problems. State list extracting means to calculate the optimal shared state path from state trajectories with cycles. A state list extracting algorithm checks cyclic state lists of a current state in the state trajectory, condensing the optimal action set of the current state. By reinforcing the optimal action selected, the action policy of cyclic states is optimized gradually. The state list extracting is repeatedly learned and used as the experience knowledge which is shared by teams. Agents speed up the rate of convergence by experience sharing. Competition games of preys and predators are used for the experiments. The results of experiments prove that the proposed algorithms overcome the lack of experience in the initial stage, speed up learning and improve the performance.
基金This study was supported by a grant from the Shanghai Science and Technology Commission Foundation, China(No.O14119002).
文摘BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors.
文摘Aim： To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor （AZF） region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods： In total, 178 infertile patients with azoospermia （nonobstructed）, 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array （MASA） technology. Results： Of the 312 patients, 36 （11.5%） were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% （25/178） in the azoospermia group and 8.2% （11/134） in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion： There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments.
文摘The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in China. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors （paleo-anticline, source rock, regional cap rock and kinematic equilibrium belt） controlling hydrocarbon accumulation, this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration ofoil and gas in the Silurian of the Tarim basin.
基金co-supported by the National Natural Science Foundation of China (Nos. 61374145 and U1333131)
文摘Heavy-equipment airdrop is a highly risky procedure that has a complicated system due to the secluded and complex nature of factors＇ coupling. As a result, it is difficult to study the modeling and safety simulation of this system. The dynamic model of the heavy-equipment airdrop is based on the Lagrange analytical mechanics, which has all the degrees of freedom and can accurately pinpoint the real-time coordinates and attitude of the carrier with its cargo. Unfavorable conditions accounted in the factors＇ models, including aircraft malfunctions and adverse environments, are established from a man-machine-environment perspective. Subsequently, a virtual simulation system for the safety research of the multi-factor coupling heavy-equipment airdrop is developed through MATLAB/Simulink, C language and Flightgear software. To verify the veracity of the theory, the verification model is built based on dynamic software ADAMS. Finally, the emulation is put to the test with the input of realistic accident variables to ascertain its feasibility and validity of this method.
基金The Guangdong Medical Scientific Research Fund(A2017375)Pingshan District Research Project(201710)
文摘Objective To investigate the patients experience in community health centers( CHCs) and explore its associated factors. Methods A cross-sectional study was conducted among 330 patients who visited CHCs in Shenzhen,China from January to March 2018. Dependent variable was patient experience. Key descriptive variables were age,gender,marital status,working status groups,visits frequency for the past 6 months,whether patients had signed a family doctor,whether trusted in family doctor,whether had chronic diseases. Results Questionnaires for 300 patients were assessed. In the univariate analysis,patients experience total score was significantly associated with marital status( P < 0. 1),working status groups( P < 0. 1),frequency of visit for the past 6 months( P < 0. 05),whether had signed a family doctor( P < 0. 05),whether trusted in family doctor( P < 0. 05),whether had chronic diseases( P < 0. 05). The multivariate analysis showed that unmarried patients( P = 0. 011,OR = 2. 96,95% CI: 1. 24-5. 43) and had signed a family doctor( P = 0. 023,OR = 0. 44,95% CI: 0. 22-0. 85) were more likely to get a higher score. Conclusions Findings of this study showed a medium-level score of patients experience in the community. Patients had a quite good experience and more interventions should be focused upon the influence factors to improve patients experience.
文摘Ultrasonic seismic model experiment plays an important role in engineering multi wave seismic prospecting(EMSP), which has been used to do the complex engineering seismic exploration. It is introduced that the application of the technology in quality test of Yongjiang river submarine tunnel tube foundation in the paper. The material of the model was got from on the spot. The successful test has been made with results of the model experiment.
