BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counselin...BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counseling;however,these methods have different degrees of side effects and limitations.In recent years,nonconvulsive electrotherapy(NET)has attracted increasing attention as a noninvasive treatment method.However,the clinical efficacy and potential mechanism of NET on depression are still unclear.We hypothesized that NET has a positive clinical effect in the treatment of depression,and may have a regulatory effect on serum inflammatory factors during treatment.AIM To assess the effects of NET on depression and analyze changes in serum inflammatory factors.METHODS This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022,the observation group that received a combination of mindfulness-based stress reduction(MBSR)and NET treatment(n=70)and the control group that only received MBSR therapy(n=70).The clinical effectiveness of the treatment was evaluated by assessing various factors,including the Hamilton Depression Scale(HAMD)-17,self-rating idea of suicide scale(SSIOS),Pittsburgh Sleep Quality Index(PSQI),and levels of serum inflammatory factors before and after 8 wk of treatment.The quality of life scores between the two groups were compared.Comparisons were made using t and χ^(2) tests.RESULTS After 8 wk of treatment,the observation group exhibited a 91.43%overall effectiveness rate which was higher than that of the control group which was 74.29%(64 vs 52,χ^(2)=7.241;P<0.05).The HAMD,SSIOS,and PSQI scores showed a significant decrease in both groups.Moreover,the observation group had lower scores than the control group(10.37±2.04 vs 14.02±2.16,t=10.280;1.67±0.28 vs 0.87±0.12,t=21.970;5.29±1.33 vs 7.94±1.35,t=11.700;P both<0.001).Additionally,there was a notable decrease in the IL-2,IL-1β,and IL-6 in both groups after treatment.Furthermore,the observation group exhibited superior serum inflammatory factors compared to the control group(70.12±10.32 vs 102.24±20.21,t=11.840;19.35±2.46 vs 22.27±2.13,t=7.508;32.25±4.6 vs 39.42±4.23,t=9.565;P both<0.001).Moreover,the observation group exhibited significantly improved quality of life scores compared to the control group(Social function:19.25±2.76 vs 16.23±2.34;Emotions:18.54±2.83 vs 12.28±2.16;Environment:18.49±2.48 vs 16.56±3.44;Physical health:19.53±2.39 vs 16.62±3.46;P both<0.001)after treatment.CONCLUSION MBSR combined with NET effectively alleviates depression,lowers inflammation(IL-2,IL-1β,and IL-6),reduces suicidal thoughts,enhances sleep,and improves the quality of life of individuals with depression.展开更多
BACKGROUND Acute pancreatitis(AP)is a common inflammatory disease of the pancreas with high mortality rates.It is of great significance to take scientific intervention measures for patients with AP in time.AIM To expl...BACKGROUND Acute pancreatitis(AP)is a common inflammatory disease of the pancreas with high mortality rates.It is of great significance to take scientific intervention measures for patients with AP in time.AIM To explore the effect of standardized nursing combined with mindfulness stress reduction training on the curative effect,negative emotion,and quality of life in patients with acute pancreatitis.METHODS A total of 80 patients with acute pancreatitis admitted to The First People's Hospital of Jiangxia District Hospital from May 2021 to May 2023 were randomly divided into control group and observation group(n=40).Patients in control group were given the standardized nursing intervention,and the observation group were given standardized nursing plus mindfulness stress reduction training intervention.The time of clinical symptom disappeared or improved,complication occurrence rate,emotional state,and quality of life score of the two groups were observed and compared.RESULTS In comparison with the control group,the bowel sound recovery time,ventosity and abdominal pain improvement time,and venting and cacation time in observation group were shorter,and the total incidence rate of complications was reduced,showing statistically significant difference(P<0.05).The scores of anxiety and depression in observation group were lower than those in control group(P<0.05).Serum levels of tumour necrosis factor alpha,interleukin(IL)-6,IL-1βand IL-8 in observation group were lower than those in control group(P<0.05).The scores of life quality in physiology,psychology,environment and social relations in observation group were higher than those in control group,and the differences were statistically significant(P<0.05).CONCLUSION The application of standardized nursing intervention combined with mindfulness stress reduction training in patients with acute pancreatitis has a definite effect,which can help to ameliorate the clinical symptoms,anxiety and depression of patients,reduce the incidence rate of complications,and improve the prognosis of patients.展开更多
To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positi...To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positive thought awareness,and psychosocial functioning of patients with depressive disorders.This review has the objective to provide clinical healthcare personnel with essential information about the use of PTSRT to improve the level of positive thought and psychosocial functioning of patients with depressive disorders.展开更多
Through introducing the analytical problem of the plate with convection into the solution of the transient heat conduction thermal stress field model of the elastic plate, the stress reduction factor is presented expl...Through introducing the analytical problem of the plate with convection into the solution of the transient heat conduction thermal stress field model of the elastic plate, the stress reduction factor is presented explicitly in its dimensionless form. A new stress reduction factor is introduced for the purpose of comparison. The proper- ties and appropriate conditions of the stress reduction factor, the first and second ther- mal shock resistance (TSR) parameters for the high and low Biot numbers, respectively, and the approximation formulas for the intermediate Blot number-interval are discussed. To investigate the TSR of ceramics more accurately, it is recommended to combine the heat transfer theory with the theory of thermoelasticity or fracture mechanics or use a numerical method. The critical rupture temperature difference and the critical rup- ture dimensionless time can be used to characterize the TSR of ceramics intuitively and legibly.展开更多
Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindful...Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindfulness-based stress reduction in nursing staff were retrieved from CNKI,WanFang,VIP,PubMed,Cochrane Library,Web of Science,EMBASE databases.The retrieval time was set from the establishment of the database to April 2020.The Review Manager 5.3 software were used for meta-analysis.Result:9 RCTs and 5 self-control trails were included with 1421,712 subjects in the experimental group and 709 subjects in the control group.The results of the meta-analysis showed that compared with the control group,mindfulness-based stress reduction therapy can effectively reduce the psychological symptoms of clinical nurses[SMD=-0.96,95%CI(-1.51,-0.38),P=0.001],reduces nurses'anxiety levels[SMD=-1.28,95%CI(-2.18,-0.38),P=0.005],relieve the nurse's depression[SMD=-1.08,95%CI(-2.15,-0.02),P=0.005],improve the mental resilience of nurse[SMD=7.05,95%CI(3.93,10.17),P=0.03],showing a statistical meaning.Conclusion:The mental health of nurses is often neglected by themselves and there is insufficient awareness that MBSR can improve mental health.There has been a debate about whether MBSR actually improves the mental health of nurses,so it is necessary to further explore this issue and seek better methods and opportunities for practice.展开更多
Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained...Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained in the welded samples. Moreover, compared with the zones with lower initial stress levels, more remarkable stress reductions were obtained in the stress concentration zones. The microstructures and magnetic domains were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Based on the analysis of the microstructure and magnetic domain changes, the mechanism of stress reduction by the magnetic treatment has been concluded: (1) the magneto-plastic deformations mainly due to the more uniform redistribution of dislocations are the fundamental cause of stress relaxation; and (2) surface topography is also proved to affect the magnetic treatment results to some degree by influencing magnetic domains.展开更多
In unstable soils, a special erosion process termed suffusion can occur under the effect of relatively low hydraulic gradient. The critical hydraulic gradient of an unstable soil is smaller than in stable soils, which...In unstable soils, a special erosion process termed suffusion can occur under the effect of relatively low hydraulic gradient. The critical hydraulic gradient of an unstable soil is smaller than in stable soils, which is described by a reduction factor α. According to a theory of Skempton and Brogan (1994) [1], this reduction factor is related to the stress conditions in the soil. In an unstable soil, the average stresses acting in the fine portion are believed to be smaller than the average stresses in the coarse portion. It is assumed that the stress ratio and the reduction factor for the hydraulic gradient are almost equal. In order to prove this theory, laboratory tests and discrete element modelings are carried out. Models of stable and unstable soils are established, and the stresses inside the sample are analysed. It is found that indeed in unstable soils the coarse grains are subject to larger stresses. The stress ratios in stable soils are almost unity, whereas in unstable soils smaller stress ratios, which are dependent on the soil composition and on the relative density of the soil, are obtained. A comparison between the results of erosion tests and numerical modeling shows that the stress ratios and the reduction factors are strongly related, as assumed by Skempton and Brogan (1994) [1].展开更多
All cells in the body metabolize oxygen in a series of reactions in the mitochondria to generate energy.A by-product of these reactions is the production of highly reactive oxygen radicals which have the potential to ...All cells in the body metabolize oxygen in a series of reactions in the mitochondria to generate energy.A by-product of these reactions is the production of highly reactive oxygen radicals which have the potential to cause irreparable damage to cellular components,and have been linked to mutagenic and neurotoxicity of the nervous system.Under normal conditions,innate molecular systems,glutathione,superoxide dismutases,展开更多
In recent years,finite element analysis is increasingly being proposed in slope stability problems as a competitive method to traditional limit equilibrium methods(LEMs)which are known for their inherent deficiencies....In recent years,finite element analysis is increasingly being proposed in slope stability problems as a competitive method to traditional limit equilibrium methods(LEMs)which are known for their inherent deficiencies.However,the application of finite element method(FEM)to slope stability as a strength reduction method(SRM)or as finite element limit analysis(FELA)is not always a success for the drawbacks that characterize both methods.To increase the performance of finite element analysis in this problem,a new approach is proposed in this paper.It consists in gradually expanding the mobilized stress Mohr’s circles until the soil failure occurs according to a prescribed non-convergence criterion.The present approach called stress deviator increasing method(SDIM)is considered rigorous for three main reasons.Firstly,it preserves the definition of the factor of safety(FOS)as the ratio of soil shear strength to the mobilized shear stress.Secondly,it maintains the progressive development of shear stress resulting from the increase in the principal stress deviator on the same plane,on which the shear strength takes place.Thirdly,by introducing the concept of equivalent stress loading,the resulting trial stresses are checked against the violation of the actual yield criterion formed with the real strength parameters rather than those reduced by a trial factor.The new numerical procedure was encoded in a Fortran computer code called S^(4)DINA and verified by several examples.Comparisons with other numerical methods such as the SRM,gravity increasing method(GIM)or even FELA by assessing both the FOS and contours of equivalent plastic strains showed promising results.展开更多
The Persian Gulf War of 1990 to 1991 involved the deployment of nearly 700,000 American troops to the Middle East.Deployment-related exposures to toxic substances such as pesticides,nerve agents,pyridostigmine bromide...The Persian Gulf War of 1990 to 1991 involved the deployment of nearly 700,000 American troops to the Middle East.Deployment-related exposures to toxic substances such as pesticides,nerve agents,pyridostigmine bromide(PB),smoke from burning oil wells,and petrochemicals may have contributed to medical illness in as many as 250,000 of those American troops.The cluster of chronic symptoms,now referred to as Gulf War Illness(GWI),has been studied by many researchers over the past two decades.Although over$500 million has been spent on GWI research,to date,no cures or condition-specific treatments have been discovered,and the exact pathophysiology remains elusive.Using the 2007 National Institute of Health(NIH)Roadmap for Medical Research model as a reference framework,we reviewed studies of interventions involving GWI patients to assess the progress of treatment-related GWI research.All GWI clinical trial studies reviewed involved investigations of existing interventions that have shown efficacy in other diseases with analogous symptoms.After reviewing the published and ongoing registered clinical trials for cognitivebehavioral therapy,exercise therapy,acupuncture,coenzyme Q10(CoQ10),mifepristone,and carnosine in GWI patients,we identified only four treatments(cognitive-behavioral therapy,exercise therapy,CoQ10,and mifepristone)that have progressed beyond a phase II trial.We conclude that progress in the scientific study of therapies for GWI has not followed the NIH Roadmap for Medical Research model.Establishment of a standard case definition,prioritized GWI research funding for the characterization of the pathophysiology of the condition,and rapid replication and adaptation of early phase,single site clinical trials could substantially advance research progress and treatment discovery for this condition.展开更多
Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. ...Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. At winter time heating costs can be reduced. The effect of air condition using geothermal energy was investigated in a farrowing house. Underneath the foundation of the farrowing house 88 non perforated ribbed tubes (diameter: 20 cm) were piped in a depth of 1.6-2.0 m. Over a period of 12 month following data were recorded at hourly intervals and analyzed: outside air temperature, as well as air temperature in the air supply duct and in the compartments. Incoming air (supply duct) was heated up to 20 ℃ during winter time and in summer time cooled by up to 15 ℃ compared to the outside air temperature. In contrast to the outside air diurnal variation, temperature fluctuations of the incoming air were reduced by 90%. Due to cooling of the incoming air at summer time the stable inside temperature could be limited to maximal 29 ℃(maximum outside temperature was 35℃). Earth-tube heat exchangers with non perforated ribbed tubes were very efficient for air conditioning in farrowing houses. They were a cost effective supplement for sustainable cooling and heating of farrowing houses.展开更多
Mindfulness-based cognitive therapy(MBCT)is frequently used for psychiatric disorders.Despite MBCT’s considerable potential for improving psychological health for patients,there is little empirical evidence to suppor...Mindfulness-based cognitive therapy(MBCT)is frequently used for psychiatric disorders.Despite MBCT’s considerable potential for improving psychological health for patients,there is little empirical evidence to support its practical application in Chinese.This review will define meditation and mindfulness,provide an overview of the development of MBCT,identify the evidence for the effectiveness of MBCT,and offer recommendations to medical personnels on how to provide support for patients receiving mindfulness intervention.展开更多
We have demonstrated polarization insensitive AWGs by controlling the doping concentration of Boron in overcladding and the etching depth of waveguide. The proposed method uses the conventional fabrication process and...We have demonstrated polarization insensitive AWGs by controlling the doping concentration of Boron in overcladding and the etching depth of waveguide. The proposed method uses the conventional fabrication process and does not degrade optical properties and reliability characteristics.展开更多
Stable flies are one of the most important arthropod pests of livestock that reduce cattle weight gain and milk production leading to annual economic losses in excess of$2 billion to the US cattle industry.The host-se...Stable flies are one of the most important arthropod pests of livestock that reduce cattle weight gain and milk production leading to annual economic losses in excess of$2 billion to the US cattle industry.The host-seeking behavior is primarily mediated by associated odors from stable fly larval development environments and host animals.The present paper reports the development and evaluation of attractant-impregnated adhesive tapes to reduce stable fly attacks on cattle.Laboratory bioassays showed that only m-cresol impregnated adhesive tapes caught significantly more stable flies(16±1)than the control tape without attractant added(7±1),with a 77%fly recapture rate.Attractant-impregnated adhesive tapes deployed in cattle feedlots showed significant impacts in reducing fly population,with a total of one million stable flies captured over a period of three weeks(mean catches from 57596 to 102088 stable flies per trap per week).It further relieved cattle stress with a significant reduction of biting fly avoidance behavior,(6±0.4 cows observed with tail wagging in control vs.3±0.4 from the trap-deployed).The efficacy of the developed tapes lasted up to 1-week longevity,although 70%of m-cresol was released starting from the second day.The m-cresol impregnated adhesive tape provided an 80%reduction in cattle stress due to stable fly attack.This is the first report of a technology developed by integrating an attractant compound into an adhesive material on a plastic film with demonstrated effectiveness in trapping biting flies that attack livestock animals.展开更多
基金Supported by Guangdong Provincial Medical Scientific Research Fund Project,No.B2016109.
文摘BACKGROUND Depression is a common and serious psychological condition,which seriously affects individual well-being and functional ability.Traditional treatment methods include drug therapy and psychological counseling;however,these methods have different degrees of side effects and limitations.In recent years,nonconvulsive electrotherapy(NET)has attracted increasing attention as a noninvasive treatment method.However,the clinical efficacy and potential mechanism of NET on depression are still unclear.We hypothesized that NET has a positive clinical effect in the treatment of depression,and may have a regulatory effect on serum inflammatory factors during treatment.AIM To assess the effects of NET on depression and analyze changes in serum inflammatory factors.METHODS This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022,the observation group that received a combination of mindfulness-based stress reduction(MBSR)and NET treatment(n=70)and the control group that only received MBSR therapy(n=70).The clinical effectiveness of the treatment was evaluated by assessing various factors,including the Hamilton Depression Scale(HAMD)-17,self-rating idea of suicide scale(SSIOS),Pittsburgh Sleep Quality Index(PSQI),and levels of serum inflammatory factors before and after 8 wk of treatment.The quality of life scores between the two groups were compared.Comparisons were made using t and χ^(2) tests.RESULTS After 8 wk of treatment,the observation group exhibited a 91.43%overall effectiveness rate which was higher than that of the control group which was 74.29%(64 vs 52,χ^(2)=7.241;P<0.05).The HAMD,SSIOS,and PSQI scores showed a significant decrease in both groups.Moreover,the observation group had lower scores than the control group(10.37±2.04 vs 14.02±2.16,t=10.280;1.67±0.28 vs 0.87±0.12,t=21.970;5.29±1.33 vs 7.94±1.35,t=11.700;P both<0.001).Additionally,there was a notable decrease in the IL-2,IL-1β,and IL-6 in both groups after treatment.Furthermore,the observation group exhibited superior serum inflammatory factors compared to the control group(70.12±10.32 vs 102.24±20.21,t=11.840;19.35±2.46 vs 22.27±2.13,t=7.508;32.25±4.6 vs 39.42±4.23,t=9.565;P both<0.001).Moreover,the observation group exhibited significantly improved quality of life scores compared to the control group(Social function:19.25±2.76 vs 16.23±2.34;Emotions:18.54±2.83 vs 12.28±2.16;Environment:18.49±2.48 vs 16.56±3.44;Physical health:19.53±2.39 vs 16.62±3.46;P both<0.001)after treatment.CONCLUSION MBSR combined with NET effectively alleviates depression,lowers inflammation(IL-2,IL-1β,and IL-6),reduces suicidal thoughts,enhances sleep,and improves the quality of life of individuals with depression.
文摘BACKGROUND Acute pancreatitis(AP)is a common inflammatory disease of the pancreas with high mortality rates.It is of great significance to take scientific intervention measures for patients with AP in time.AIM To explore the effect of standardized nursing combined with mindfulness stress reduction training on the curative effect,negative emotion,and quality of life in patients with acute pancreatitis.METHODS A total of 80 patients with acute pancreatitis admitted to The First People's Hospital of Jiangxia District Hospital from May 2021 to May 2023 were randomly divided into control group and observation group(n=40).Patients in control group were given the standardized nursing intervention,and the observation group were given standardized nursing plus mindfulness stress reduction training intervention.The time of clinical symptom disappeared or improved,complication occurrence rate,emotional state,and quality of life score of the two groups were observed and compared.RESULTS In comparison with the control group,the bowel sound recovery time,ventosity and abdominal pain improvement time,and venting and cacation time in observation group were shorter,and the total incidence rate of complications was reduced,showing statistically significant difference(P<0.05).The scores of anxiety and depression in observation group were lower than those in control group(P<0.05).Serum levels of tumour necrosis factor alpha,interleukin(IL)-6,IL-1βand IL-8 in observation group were lower than those in control group(P<0.05).The scores of life quality in physiology,psychology,environment and social relations in observation group were higher than those in control group,and the differences were statistically significant(P<0.05).CONCLUSION The application of standardized nursing intervention combined with mindfulness stress reduction training in patients with acute pancreatitis has a definite effect,which can help to ameliorate the clinical symptoms,anxiety and depression of patients,reduce the incidence rate of complications,and improve the prognosis of patients.
基金Research Project of Yunnan Provincial Psychiatric Hospital(No:Provincial Jing Research 2022-13)。
文摘To review the current research status of positive thought stress reduction therapy(PTSRT),psychosocial functioning of patients with depressive disorders,the shortcomings and outlook of the influence of PTSRT on positive thought awareness,and psychosocial functioning of patients with depressive disorders.This review has the objective to provide clinical healthcare personnel with essential information about the use of PTSRT to improve the level of positive thought and psychosocial functioning of patients with depressive disorders.
基金Project supported by the National Natural Science Foundation of China (Nos. 90916009 and11172336)
文摘Through introducing the analytical problem of the plate with convection into the solution of the transient heat conduction thermal stress field model of the elastic plate, the stress reduction factor is presented explicitly in its dimensionless form. A new stress reduction factor is introduced for the purpose of comparison. The proper- ties and appropriate conditions of the stress reduction factor, the first and second ther- mal shock resistance (TSR) parameters for the high and low Biot numbers, respectively, and the approximation formulas for the intermediate Blot number-interval are discussed. To investigate the TSR of ceramics more accurately, it is recommended to combine the heat transfer theory with the theory of thermoelasticity or fracture mechanics or use a numerical method. The critical rupture temperature difference and the critical rup- ture dimensionless time can be used to characterize the TSR of ceramics intuitively and legibly.
文摘Objective:To systematically evaluate the effects of MBSR on psychological health intervention in nurses.Methods:The randomized controlled trial(RCT)and self-controlled trial(SC)investigating the application of mindfulness-based stress reduction in nursing staff were retrieved from CNKI,WanFang,VIP,PubMed,Cochrane Library,Web of Science,EMBASE databases.The retrieval time was set from the establishment of the database to April 2020.The Review Manager 5.3 software were used for meta-analysis.Result:9 RCTs and 5 self-control trails were included with 1421,712 subjects in the experimental group and 709 subjects in the control group.The results of the meta-analysis showed that compared with the control group,mindfulness-based stress reduction therapy can effectively reduce the psychological symptoms of clinical nurses[SMD=-0.96,95%CI(-1.51,-0.38),P=0.001],reduces nurses'anxiety levels[SMD=-1.28,95%CI(-2.18,-0.38),P=0.005],relieve the nurse's depression[SMD=-1.08,95%CI(-2.15,-0.02),P=0.005],improve the mental resilience of nurse[SMD=7.05,95%CI(3.93,10.17),P=0.03],showing a statistical meaning.Conclusion:The mental health of nurses is often neglected by themselves and there is insufficient awareness that MBSR can improve mental health.There has been a debate about whether MBSR actually improves the mental health of nurses,so it is necessary to further explore this issue and seek better methods and opportunities for practice.
基金funded by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Ministry of Education, China (No.[2002]383)the Science and Technology Planning Project of Wuhan City, China (No.20067003111-05)
文摘Residual stress reduction in low alloy steel by a low frequency alternating magnetic treatment and its mechanism were investigated. Experimental results revealed that average stress reductions of 20%-24% were obtained in the welded samples. Moreover, compared with the zones with lower initial stress levels, more remarkable stress reductions were obtained in the stress concentration zones. The microstructures and magnetic domains were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Based on the analysis of the microstructure and magnetic domain changes, the mechanism of stress reduction by the magnetic treatment has been concluded: (1) the magneto-plastic deformations mainly due to the more uniform redistribution of dislocations are the fundamental cause of stress relaxation; and (2) surface topography is also proved to affect the magnetic treatment results to some degree by influencing magnetic domains.
文摘In unstable soils, a special erosion process termed suffusion can occur under the effect of relatively low hydraulic gradient. The critical hydraulic gradient of an unstable soil is smaller than in stable soils, which is described by a reduction factor α. According to a theory of Skempton and Brogan (1994) [1], this reduction factor is related to the stress conditions in the soil. In an unstable soil, the average stresses acting in the fine portion are believed to be smaller than the average stresses in the coarse portion. It is assumed that the stress ratio and the reduction factor for the hydraulic gradient are almost equal. In order to prove this theory, laboratory tests and discrete element modelings are carried out. Models of stable and unstable soils are established, and the stresses inside the sample are analysed. It is found that indeed in unstable soils the coarse grains are subject to larger stresses. The stress ratios in stable soils are almost unity, whereas in unstable soils smaller stress ratios, which are dependent on the soil composition and on the relative density of the soil, are obtained. A comparison between the results of erosion tests and numerical modeling shows that the stress ratios and the reduction factors are strongly related, as assumed by Skempton and Brogan (1994) [1].
文摘All cells in the body metabolize oxygen in a series of reactions in the mitochondria to generate energy.A by-product of these reactions is the production of highly reactive oxygen radicals which have the potential to cause irreparable damage to cellular components,and have been linked to mutagenic and neurotoxicity of the nervous system.Under normal conditions,innate molecular systems,glutathione,superoxide dismutases,
文摘In recent years,finite element analysis is increasingly being proposed in slope stability problems as a competitive method to traditional limit equilibrium methods(LEMs)which are known for their inherent deficiencies.However,the application of finite element method(FEM)to slope stability as a strength reduction method(SRM)or as finite element limit analysis(FELA)is not always a success for the drawbacks that characterize both methods.To increase the performance of finite element analysis in this problem,a new approach is proposed in this paper.It consists in gradually expanding the mobilized stress Mohr’s circles until the soil failure occurs according to a prescribed non-convergence criterion.The present approach called stress deviator increasing method(SDIM)is considered rigorous for three main reasons.Firstly,it preserves the definition of the factor of safety(FOS)as the ratio of soil shear strength to the mobilized shear stress.Secondly,it maintains the progressive development of shear stress resulting from the increase in the principal stress deviator on the same plane,on which the shear strength takes place.Thirdly,by introducing the concept of equivalent stress loading,the resulting trial stresses are checked against the violation of the actual yield criterion formed with the real strength parameters rather than those reduced by a trial factor.The new numerical procedure was encoded in a Fortran computer code called S^(4)DINA and verified by several examples.Comparisons with other numerical methods such as the SRM,gravity increasing method(GIM)or even FELA by assessing both the FOS and contours of equivalent plastic strains showed promising results.
文摘The Persian Gulf War of 1990 to 1991 involved the deployment of nearly 700,000 American troops to the Middle East.Deployment-related exposures to toxic substances such as pesticides,nerve agents,pyridostigmine bromide(PB),smoke from burning oil wells,and petrochemicals may have contributed to medical illness in as many as 250,000 of those American troops.The cluster of chronic symptoms,now referred to as Gulf War Illness(GWI),has been studied by many researchers over the past two decades.Although over$500 million has been spent on GWI research,to date,no cures or condition-specific treatments have been discovered,and the exact pathophysiology remains elusive.Using the 2007 National Institute of Health(NIH)Roadmap for Medical Research model as a reference framework,we reviewed studies of interventions involving GWI patients to assess the progress of treatment-related GWI research.All GWI clinical trial studies reviewed involved investigations of existing interventions that have shown efficacy in other diseases with analogous symptoms.After reviewing the published and ongoing registered clinical trials for cognitivebehavioral therapy,exercise therapy,acupuncture,coenzyme Q10(CoQ10),mifepristone,and carnosine in GWI patients,we identified only four treatments(cognitive-behavioral therapy,exercise therapy,CoQ10,and mifepristone)that have progressed beyond a phase II trial.We conclude that progress in the scientific study of therapies for GWI has not followed the NIH Roadmap for Medical Research model.Establishment of a standard case definition,prioritized GWI research funding for the characterization of the pathophysiology of the condition,and rapid replication and adaptation of early phase,single site clinical trials could substantially advance research progress and treatment discovery for this condition.
文摘Earth tempering of stable air has attracted great attention as a sustainable air conditioning method in pig houses. At summer time air cooling of income air strongly reduces heat stress and required ventilation rate. At winter time heating costs can be reduced. The effect of air condition using geothermal energy was investigated in a farrowing house. Underneath the foundation of the farrowing house 88 non perforated ribbed tubes (diameter: 20 cm) were piped in a depth of 1.6-2.0 m. Over a period of 12 month following data were recorded at hourly intervals and analyzed: outside air temperature, as well as air temperature in the air supply duct and in the compartments. Incoming air (supply duct) was heated up to 20 ℃ during winter time and in summer time cooled by up to 15 ℃ compared to the outside air temperature. In contrast to the outside air diurnal variation, temperature fluctuations of the incoming air were reduced by 90%. Due to cooling of the incoming air at summer time the stable inside temperature could be limited to maximal 29 ℃(maximum outside temperature was 35℃). Earth-tube heat exchangers with non perforated ribbed tubes were very efficient for air conditioning in farrowing houses. They were a cost effective supplement for sustainable cooling and heating of farrowing houses.
基金This work was funded by the Chia Family Foundation Health Fellowship Program which funded by the Yale-China Association(2013-2015).
文摘Mindfulness-based cognitive therapy(MBCT)is frequently used for psychiatric disorders.Despite MBCT’s considerable potential for improving psychological health for patients,there is little empirical evidence to support its practical application in Chinese.This review will define meditation and mindfulness,provide an overview of the development of MBCT,identify the evidence for the effectiveness of MBCT,and offer recommendations to medical personnels on how to provide support for patients receiving mindfulness intervention.
文摘We have demonstrated polarization insensitive AWGs by controlling the doping concentration of Boron in overcladding and the etching depth of waveguide. The proposed method uses the conventional fabrication process and does not degrade optical properties and reliability characteristics.
文摘Stable flies are one of the most important arthropod pests of livestock that reduce cattle weight gain and milk production leading to annual economic losses in excess of$2 billion to the US cattle industry.The host-seeking behavior is primarily mediated by associated odors from stable fly larval development environments and host animals.The present paper reports the development and evaluation of attractant-impregnated adhesive tapes to reduce stable fly attacks on cattle.Laboratory bioassays showed that only m-cresol impregnated adhesive tapes caught significantly more stable flies(16±1)than the control tape without attractant added(7±1),with a 77%fly recapture rate.Attractant-impregnated adhesive tapes deployed in cattle feedlots showed significant impacts in reducing fly population,with a total of one million stable flies captured over a period of three weeks(mean catches from 57596 to 102088 stable flies per trap per week).It further relieved cattle stress with a significant reduction of biting fly avoidance behavior,(6±0.4 cows observed with tail wagging in control vs.3±0.4 from the trap-deployed).The efficacy of the developed tapes lasted up to 1-week longevity,although 70%of m-cresol was released starting from the second day.The m-cresol impregnated adhesive tape provided an 80%reduction in cattle stress due to stable fly attack.This is the first report of a technology developed by integrating an attractant compound into an adhesive material on a plastic film with demonstrated effectiveness in trapping biting flies that attack livestock animals.