Purpose: To identify, analyze and synthetize the scientific evidences that support Early Life Stress (ELS) diagnosis using the Childhood Trauma Questionnaire (CTQ), since it assumes the use of psychoactive substances ...Purpose: To identify, analyze and synthetize the scientific evidences that support Early Life Stress (ELS) diagnosis using the Childhood Trauma Questionnaire (CTQ), since it assumes the use of psychoactive substances later in adolescence and adulthood. Individuals that experienced some form of childhood stress may present, in adulthood, consequences that manifest into mental disorders such as problematic use of psychoactive substances. Methods: An integrative review of the literature on the subject in the databases: PubMed, Web of Science, LILACS and Psycinfo, regards studies that have been indexed in the last ten years (2003-2014). Combination of controlled and uncontrolled factors in the use and abuse of psychoactive substances, CTQ and ELS adapted to each database. Findings: The alcohol was the most used drug by the participating subjects of these research;mostly, the use of psychoactive drugs, started when they were still in adolescence;ELS and the later use of psychoactive drugs can be found more frequently in female;the lack of internal resources for dealing with stress in adulthood after ELS occurrence may have as a consequence the use of psychoactive drugs as a coping mechanism. Conclusions: It was possible to identify scientific evidences that support the ELS diagnosis, measured by the CTQ, as a determining factor for the use and abuse of alcohol and/or other psychoactive drugs in adolescence and adulthood. Implications: Investigate the ELS as a strategy to improve the therapeutic project of patients in nursing care, which will be built based on scientific evidence, so it can be more effective.展开更多
In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community,...In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community, the migrant worker and city people’s relations belongs to typical in community’s relations with the outside community, among them not only isolates and repels psychologically mutually, but also has the direct conflicts of interest. This not only causes the migrant worker to suffer the prejudice and discrimination of city people, is hard to be a part of the city life, but also causes repellency urban institutional arrangements to disintegrate to a certain extent difficultly while the migrant worker is hard to enter in the urban system. Under this basis, this paper proposes the health and life stress assisted development trend of urbanization of the rural migrant workers basic research, the idea is new and innovative, in the later time we will apply it more.展开更多
Background: Early life stress is a significant public health problem associated with increased rates of psychiatric disorders, especially those related to drug abuse. Objective: To identify the prevalence of early lif...Background: Early life stress is a significant public health problem associated with increased rates of psychiatric disorders, especially those related to drug abuse. Objective: To identify the prevalence of early life stress in drug users, to compare the intensity of trauma in alcohol and crack users, and to relate the power of injury to the severity of drug dependence. Method: Cross-sectional analytical study with a sample of 105 alcohol and crack users treated by an outpatient service. The instruments for data collection were sociodemographic data questionnaire, the Mini-International Neuropsychiatric Interview, and the Severity of Dependence Scale. The categorical variables association was analyzed using the Chi-squared test, considering p Results: High prevalence of early stress and severity of dependence were identified, with higher rates among crack users. The early stress revealed in the Alcohol group high rates of emotional (88.7%) and physical (94.3%) neglect and in the Crack group significant frequency of physical (61.5%) emotional abuse (51.9%), sexual (46.2%), and emotional (78.8%) and physical (90.4%) neglect. Crack users are 2.6 times more likely to have been emotionally abused, and 2.1 times more likely to have been sexually abused during childhood when compared to the alcohol group. Conclusion: Early stress was prevalent with significant intensity in drug users, and evaluation of this problem is essential for a better understanding of these disorders.展开更多
Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors inclu...Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors including economic stress imposed by precariousness, poor living conditions, sources of anxiety, anguish, depression and other behavioral disorders. Economic stress is a globalizing concept that integrates into a purely hermeneutic approach, a particular functioning of the nervous system of an individual who faces employment problems and precarious remuneration conditions. The non-satisfaction by an individual of his basic needs due to insufficient financial means can cause him to become irritable, aggressive, and socially and symbolically isolated, thereby increasing the desire to resort to morbid life models such as excessive consumption of narcotics and other psychoactive substances often associated with high blood pressure. The fight against the emergence of BPH is a complex, multifaceted and multifactorial reality that requires taking into account economic stress. The main objective of this survey is to describe the situation of economic stress within the Cameroonian population, which imposes precariousness and life models at risk of high blood pressure. Specifically, we determined the level of household income and the sources of income. Methods: A cross-sectional survey with a descriptive aim among five hundred households in the Central Region of Cameroon was conducted. A probabilistic technique called simple randomness was used. The number of households to be surveyed was determined indirectly using the Cochrane formula. Data collection in face-to-face mode using a physical questionnaire took place from July 1 to August 31, 2023, after obtaining ethical clearance from the Regional Health Research Ethics Committee, Human from the Center and an administrative authorization for data collection. Regarding their processing, the data was grouped during processing in Excel sheets. Normality and reliability tests of the collected data were carried out. For this, the Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value. Descriptive analysis was possible using R software version 3.2, SPSS version 25.0, XLSTAT 2016, PAST and EXCEL programs from Microsoft Office 2013. Results: The main results highlight economic stress, with 45.60% of households surveyed earning less than US$154 per month;55% of household heads were women in single-parent families;14% of household heads were unemployed, 22% worked in the private sector and 19% were self-employed. This general economic situation leads to precarious living conditions, thereby increasing the risk of high blood pressure among the Cameroonian population.展开更多
Objective Although stressful life events represent an etiologic factor of mental health problems in adolescents, few studies have been conducted to address mechanisms linking the stress-psychopathology relation. The p...Objective Although stressful life events represent an etiologic factor of mental health problems in adolescents, few studies have been conducted to address mechanisms linking the stress-psychopathology relation. The present study was designed to examine coping as a mediate factor on the relationship between stressful life events and symptoms of anxiety and depression. Methods The participants were 13 512 students from eight cities of China, who participated in a school-based survey. Data were collected by a questionnaire comprising coping, stressful life events, anxiety, and depressive symptoms. As a model, a series of regression equations were used to examine whether coping mediated the association between stressful life events and symptoms of anxiety and depression. Results Each dimension of stressful life events showed significant correlation with anxiety, depression and coping (all P〈0.001). In the model to analyze mediate effects, all standardized coefficients (β) were significant (all P〈0.01), indicating marked mediator effects. Furthermore, negative coping might account for more mediate effects than positive coping on this relationship. Conclusion Coping partially mediated the relationship between stressful life events and mental health during adolescence. This study highlighted an important public health priority for preventive interventions targeting stress-related psychopathology, and for further promoting adolescents' mental health.展开更多
AIM: To examine the psychological impact of chronic hepatitis C (CHC) diagnosis in a large cohort of CHC patients as compared with other stressful life events and chronic diseases carrying a risk of life-threatenin...AIM: To examine the psychological impact of chronic hepatitis C (CHC) diagnosis in a large cohort of CHC patients as compared with other stressful life events and chronic diseases carrying a risk of life-threatening complications. METHODS: One hundred and eighty-five outpatients with compensated CHC were asked to self-grade, using a 100-mm visual analogue scale (VAS), the degree of stress caused by the learning of CHC diagnosis and the perceived severity of their disease. Diagnosis-related stress was compared to four other stressful life events and perceived CHC severity was compared to four other common chronic diseases. RESULTS: Learning of CHC diagnosis was considered a major stressful event (mean ± SD scores: 72±25), significantly less than death of a loved-one (89±13, P〈0.0001) and divorce (78 ± 23, P〈0.007), but more than job dismissal (68 ± 30, P〈 0.04) and home removal (26±24, P〈 0.0001). CHC was considered a severe disease (74± 19), after AIDS (94±08, P〈 0.001) and cancer (91± 11, P〈 0.001), but before diabetes (66±23, P〈0.001) and hypertension (62±20, P〈0.001). Perceived CHC severity was not related to the actual severity of liver disease, assessed according to Metavir fibrosis score. In multivariate analysis, diagnosisrelated stress was related to perceived disease severity (P〈0.001), trait anxiety (P〈 0.001) and infection through blood transfusion (P〈 0.001). CONCLUSION: Our results show the considerable psychological and emotional burden that a diagnosis of CHC represents, even in the absence of significant liver disease. They should be taken into account when announcing a diagnosis of CHC in order to reduce its negative effects.展开更多
Mechatronic products usually endure the variable stress spectrum when they operate in certain operational condition and environmental condition, which obey the Weibull distribution. In accordance with the features of ...Mechatronic products usually endure the variable stress spectrum when they operate in certain operational condition and environmental condition, which obey the Weibull distribution. In accordance with the features of mechatronic product, this paper analyzes the failure mode, its corresponding sensitive stress and the design principles of life testing profiles. Based on the above analyses, this paper presents a synthetic stress life testing method based on the hybrid Weibull distribution and its statistical method under variable stress spectrum to evaluate the reliability and life indices of mechatronic products. Because the mechatronic products have many characteristics such as high price, long life and small testing samples, the synthetic stress life testing method under variable load spectrum can simulate the real various spectra, decrease the life testing time and reduce the testing samples. So it is effective to carry out the life testing to mechatronic products. The application results of hydraulic pumps indicate that this method can easily handle the experimental data under variable amplitude spectrum, obtain the high precision parameters point estimation and confidence interval estimation and reduce the testing cost greatly.展开更多
Through the failure mechanism analysi s and simulation test of a certain kind of detonator,this paper confirms the str ess level of the stepping stress acceleration life test of the detonator,and t hen e stablishes th...Through the failure mechanism analysi s and simulation test of a certain kind of detonator,this paper confirms the str ess level of the stepping stress acceleration life test of the detonator,and t hen e stablishes the data processing mathematical model and storage life forecasting m ethod.At last,according to the result of the stepping stress acceleration lif e test of the detonator,this paper forecasts the reliable storage life of the detonator under the normal stress level.展开更多
Tool wear has an important influence on the residual stress distribution on the machined surface.Also,it will influence the fatigue life of finished workpiece. In this research,the hard turning process of hardened die...Tool wear has an important influence on the residual stress distribution on the machined surface.Also,it will influence the fatigue life of finished workpiece. In this research,the hard turning process of hardened die steel Cr12 MoV was studied by using PCBN tool with considering tool wear. Based on the numerical treatment of residual stress,the dispersion and distribution curves of different tool wear were fitted,and the influence mechanism of tool wear on the residual stress distribution of machined surface was analyzed.Based on the theory of fatigue mechanics and mathematical statistics,the mathematical model for difference of stress dispersion and fatigue life was established. The rotating and bending tests were carried out on the standard parts after cutting process for the workpiece. The influence of tool wear on fatigue life was revealed by fracture surface morphology and fatigue life study. The results provide theoretical support for control of residual stress and the fatigue property of the machined surface under the actual working conditions.展开更多
The design and sizing of new mechanical components which are intended to operate under cyclic loads often require an acceptable level of confidence that the components will meet pre-defined fatigue strength objectives...The design and sizing of new mechanical components which are intended to operate under cyclic loads often require an acceptable level of confidence that the components will meet pre-defined fatigue strength objectives for crack initiation. For loads with multiple amplitudes and mean values, models based on Palmgren-Miner’s linear cumulative damage hypothesis and on multiple S/N curves (stress-no. cycles) are widely used in estimations for the duration of crack initiation. In this paper a procedure for generating S/N curves for multiple stress ratios by interpolation or extrapolation from the data available for two such curves is proposed. At any number of cycles, the stress for crack initiation is calculated from the far field macroscopic stresses of the known curves using Dang Van fatigue criterion and microscopic stresses evaluated at the grain level. An algorithm is presented for uniaxial loading and results verifications against curves established from laboratory tests with elastic and plastic stresses are shown and discussed for notched and un-notched specimens.展开更多
A fourth generation single crystal(SC)nickel based cast superalloy DD15 with 1%Ru,3%Ru,5%Ru was prepared using vacuum induction single crystal furnace in order to optimize the properties and cost of DD15 alloy.The exp...A fourth generation single crystal(SC)nickel based cast superalloy DD15 with 1%Ru,3%Ru,5%Ru was prepared using vacuum induction single crystal furnace in order to optimize the properties and cost of DD15 alloy.The exposure experiment of three alloys was conducted at 1100℃for 1000 h.The stress rupture properties tests were performed at 1100℃temperature and 137 MPa pressure.The composition optimization of Ru element in DD15 alloy had been studied.It was found that the alloys with different Ru contents all consist of cuboidalγ′phase embedded coherent inγphase.Theγ′phase of the alloy all has a size of about 300-500 nm and a volume content of more than sixty percent.The dimension ofγ′precipitates is reduced and uniform with increase of Ru content.Ru element can reduce the distribution ratio of high melting point element,so the microstructural stability is enhanced with Ru content increasing.No topologically close-packed(TCP)phase precipitated in the 5%Ru alloy even after 1000 h exposure.The stress rupture life of the alloy is significantly improved as Ru content rising.The raft breadth decreases slightly as Ru content increases.The specimen with 1%Ru and 3%Ru exhibits the presence of TCP phases and without TCP phases precipitated in fracture specimen with 5%Ru.The density and integrity ofγ/γ′interfacial dislocation network increase as Ru content of the alloy rises.展开更多
The paper calculated the temperature and stress fields of 1000 MW ultra-supercritical steam turbine rotors which start in cold condition using the finite element calculation program (ANSYS). After getting rotor stress...The paper calculated the temperature and stress fields of 1000 MW ultra-supercritical steam turbine rotors which start in cold condition using the finite element calculation program (ANSYS). After getting rotor stress field, the paper use the general slope method to estimate the low cycle fatigue life loss, the rest of the conditions can be calculated in this method.展开更多
In this study, fatigue tests under different R ratios were conducted on the AZ61 Mg alloy to investigate its fatigue lifetimes and fatigue crack growth (FCG) behavior. The fracture surface of the failed specimens was ...In this study, fatigue tests under different R ratios were conducted on the AZ61 Mg alloy to investigate its fatigue lifetimes and fatigue crack growth (FCG) behavior. The fracture surface of the failed specimens was investigated using a scanning electron microscope to study the size of the intermetallic compounds from which the pioneer fatigue crack initiated and led to the final failure of the specimen. To determine the maximum size of the intermetallic compounds existing within the cross section of the specimen at higher risk, Gumbel’s extreme-value statistics were utilized. In the present study, the intermetallic compounds contained within the specimen were assumed to be the initial cracks existing in the material before the fatigue tests. A modified linear elastic fracture-mechanics parameter, M, proposed by McEvily et al., was used to analyze the short FCG behavior under different stress ratios, R. The relation between the rate of FCG and M parameter was found to be useful and appropriate for predicting the fatigue lifetimes under different R ratios. Moreover, the probabilistic stress-fatigue life (P-S-N) curve of the material under different R ratios could be predicted with this method, which utilizes both the FCG law and a statistical distribution of sizes of the most dangerous intermetallic compounds. The evaluated results were in good agreement with the experimental ones. This correspondence indicates that the estimation method proposed in the present study is effective for evaluation of the probabilistic stress-fatigue life (P-S-N) curve of the material under different R ratios.展开更多
Many studies about the health problems of persons with physical disabilities have been performed, however few studies have focused on the life circumstances of persons with physical disabilities. This study aimed to c...Many studies about the health problems of persons with physical disabilities have been performed, however few studies have focused on the life circumstances of persons with physical disabilities. This study aimed to clarify the relationship between stress and the life circumstances of persons with congenital physical disabilities who must use wheelchairs. The participants were 70 individuals who used the services of care workers employed by welfare service business offices. Participants used wheelchairs. In addition, those participants who used a standard manual wheelchair were not able to operate it alone. Participants were required to answer a two-part questionnaire with questions about factors related to basic lifestyle and stress, and about life factors related to the stress of individuals with physical disabilities. No significant relationship between lifestyle and stress was found in either males or females. Most persons with congenital physical disabilities using wheelchairs had some kind of stress in daily life. In particular, significantly more level of stress was found in females (90%) than that in males (65%). Levels of stress according to life factor differed between males and females. The most dramatic gender difference was that the level of stress caused by the mental or mind factor in females was significantly higher than that in males (p < 0.05). Most persons who must use wheelchairs have stress resulting from daily life, and in particular, females experience more mental stress than males.展开更多
Introduction: Disputativeness and incitement are one of the consequences of the posttraumatic stress disorder which causes intimacy reduction in veteran wives. This study was done with the aim of expressing the vetera...Introduction: Disputativeness and incitement are one of the consequences of the posttraumatic stress disorder which causes intimacy reduction in veteran wives. This study was done with the aim of expressing the veteran posttraumatic stress disorder wives. Method: This qualitative study was done by qualitative content analysis method and 14 participants took part in this study who were all PTSD veteran wives in Golestan province in Iran. Data was gathered by semi-structured interview and by purposive sampling and was continued to the data well saturated. Data analysis was continuously done at the same time as collecting the data. Findings: The main theme and the eleven subtheme included: 1) Entanglement with wife condition: Not willing to have medicine treatment, frequent hospitalized, increasing the problems as the age goes up medicine, dependency on taking medicine, unpredictable wife behavior;2) life erosion: Living along with fear, lost life;3) stressful atmosphere in the house: Physical fight, unsecured feeling in the house, sensitive to noise;4) being worry about future: Hopelessness, spoiled life. These were the main points of this study which cause the unsecured atmosphere for the families. Conclusion: Veteran in ability in controlling their anger causes emotional problems, intimacy decreasing and marriage dissatisfaction, anxiousness and being worry about future. Social and family supports such as consulting services, informative and educational systems have an important role in wives compatibility and life promotion.展开更多
The aim of this study is to investigate the relationship between life orientation and cognitive emotion regulation with job stress. On this basis, a sample of 100 employees working in Guilan Education Office was used ...The aim of this study is to investigate the relationship between life orientation and cognitive emotion regulation with job stress. On this basis, a sample of 100 employees working in Guilan Education Office was used and research hypotheses were examined by job stress, life orientation and cognitive emotion regulation questionnaires. The results of this study indicate that job stress has a significant relationship with life orientation (-0.32), self-blame (0.25), rumination (-0.36), positive refocusing (0.25), positive refocusing on program (-0.21), positive reappraisal (-0.28), catastrophizing (-0.39) and other blames (-0.25). Furthermore, life orientation and cognitive regulation could explain 22% variances in respondents’ job stress. This finding indicates that more positive life orientation and subsequent decrease of emotion-regulation-related disorders will lead to less job stress.展开更多
To estimate the life of vacuum fluorescent display (VFD) more accurately and reduce test time and cost, four constant stress accelerated life tests (CSALTs) were conducted on an accelerated life test model. In the...To estimate the life of vacuum fluorescent display (VFD) more accurately and reduce test time and cost, four constant stress accelerated life tests (CSALTs) were conducted on an accelerated life test model. In the model, statistical analysis of test data is achieved by applying lognormal function to describe the life distribution, and least square method (LSM) to calculate the mean value and the standard deviation of logarithm. As a result, the accelerated life equation was obtained, and then a self-developed software was developed to predict the VFD life. The data analysis results demonstrate that the VFD life submits to lognormal distribution, that the accelerated model meets the linear Arrhenius equation, and that the precise accelerated parameter makes it possible to acquire the life information of VFD within one month.展开更多
Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed tha...Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality criteria.Finally, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.展开更多
Purpose: This study is aimed at comparing the level of occupational stress, ways of coping and the quality of life among nurses. Methods: Descriptive explanatory design was used with 278 nurses working in King Abdul A...Purpose: This study is aimed at comparing the level of occupational stress, ways of coping and the quality of life among nurses. Methods: Descriptive explanatory design was used with 278 nurses working in King Abdul Aziz Hospital in Jeddah, Mental Health Hospital in Jeddah, and Dr. Suleiman Fakeeh Hospital in Jeddah. Findings: Psychiatric nurses experience greater occupational stress than general nurses (p = 0.001). There was no statistically significant difference between the psychiatric and general nurses in relation to coping strategies (p = 0.38). Conclusion: Healthcare institutions should adapt stress evaluation and coping models specific to their unit. Practical Implication: Implementation of programs in each healthcare unit to educate nurses how to deal with work stressors and their negative effects.展开更多
文摘Purpose: To identify, analyze and synthetize the scientific evidences that support Early Life Stress (ELS) diagnosis using the Childhood Trauma Questionnaire (CTQ), since it assumes the use of psychoactive substances later in adolescence and adulthood. Individuals that experienced some form of childhood stress may present, in adulthood, consequences that manifest into mental disorders such as problematic use of psychoactive substances. Methods: An integrative review of the literature on the subject in the databases: PubMed, Web of Science, LILACS and Psycinfo, regards studies that have been indexed in the last ten years (2003-2014). Combination of controlled and uncontrolled factors in the use and abuse of psychoactive substances, CTQ and ELS adapted to each database. Findings: The alcohol was the most used drug by the participating subjects of these research;mostly, the use of psychoactive drugs, started when they were still in adolescence;ELS and the later use of psychoactive drugs can be found more frequently in female;the lack of internal resources for dealing with stress in adulthood after ELS occurrence may have as a consequence the use of psychoactive drugs as a coping mechanism. Conclusions: It was possible to identify scientific evidences that support the ELS diagnosis, measured by the CTQ, as a determining factor for the use and abuse of alcohol and/or other psychoactive drugs in adolescence and adulthood. Implications: Investigate the ELS as a strategy to improve the therapeutic project of patients in nursing care, which will be built based on scientific evidence, so it can be more effective.
文摘In this paper, we conduct research on the development trend of urbanization of the rural migrant workers from the perspectives of health and life stress. According to the theory of modern sociological about community, the migrant worker and city people’s relations belongs to typical in community’s relations with the outside community, among them not only isolates and repels psychologically mutually, but also has the direct conflicts of interest. This not only causes the migrant worker to suffer the prejudice and discrimination of city people, is hard to be a part of the city life, but also causes repellency urban institutional arrangements to disintegrate to a certain extent difficultly while the migrant worker is hard to enter in the urban system. Under this basis, this paper proposes the health and life stress assisted development trend of urbanization of the rural migrant workers basic research, the idea is new and innovative, in the later time we will apply it more.
文摘Background: Early life stress is a significant public health problem associated with increased rates of psychiatric disorders, especially those related to drug abuse. Objective: To identify the prevalence of early life stress in drug users, to compare the intensity of trauma in alcohol and crack users, and to relate the power of injury to the severity of drug dependence. Method: Cross-sectional analytical study with a sample of 105 alcohol and crack users treated by an outpatient service. The instruments for data collection were sociodemographic data questionnaire, the Mini-International Neuropsychiatric Interview, and the Severity of Dependence Scale. The categorical variables association was analyzed using the Chi-squared test, considering p Results: High prevalence of early stress and severity of dependence were identified, with higher rates among crack users. The early stress revealed in the Alcohol group high rates of emotional (88.7%) and physical (94.3%) neglect and in the Crack group significant frequency of physical (61.5%) emotional abuse (51.9%), sexual (46.2%), and emotional (78.8%) and physical (90.4%) neglect. Crack users are 2.6 times more likely to have been emotionally abused, and 2.1 times more likely to have been sexually abused during childhood when compared to the alcohol group. Conclusion: Early stress was prevalent with significant intensity in drug users, and evaluation of this problem is essential for a better understanding of these disorders.
文摘Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors including economic stress imposed by precariousness, poor living conditions, sources of anxiety, anguish, depression and other behavioral disorders. Economic stress is a globalizing concept that integrates into a purely hermeneutic approach, a particular functioning of the nervous system of an individual who faces employment problems and precarious remuneration conditions. The non-satisfaction by an individual of his basic needs due to insufficient financial means can cause him to become irritable, aggressive, and socially and symbolically isolated, thereby increasing the desire to resort to morbid life models such as excessive consumption of narcotics and other psychoactive substances often associated with high blood pressure. The fight against the emergence of BPH is a complex, multifaceted and multifactorial reality that requires taking into account economic stress. The main objective of this survey is to describe the situation of economic stress within the Cameroonian population, which imposes precariousness and life models at risk of high blood pressure. Specifically, we determined the level of household income and the sources of income. Methods: A cross-sectional survey with a descriptive aim among five hundred households in the Central Region of Cameroon was conducted. A probabilistic technique called simple randomness was used. The number of households to be surveyed was determined indirectly using the Cochrane formula. Data collection in face-to-face mode using a physical questionnaire took place from July 1 to August 31, 2023, after obtaining ethical clearance from the Regional Health Research Ethics Committee, Human from the Center and an administrative authorization for data collection. Regarding their processing, the data was grouped during processing in Excel sheets. Normality and reliability tests of the collected data were carried out. For this, the Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value. Descriptive analysis was possible using R software version 3.2, SPSS version 25.0, XLSTAT 2016, PAST and EXCEL programs from Microsoft Office 2013. Results: The main results highlight economic stress, with 45.60% of households surveyed earning less than US$154 per month;55% of household heads were women in single-parent families;14% of household heads were unemployed, 22% worked in the private sector and 19% were self-employed. This general economic situation leads to precarious living conditions, thereby increasing the risk of high blood pressure among the Cameroonian population.
基金supported by the National Hi-tech Research and Development Program(863 Program)of China(No.2006AA02Z427)
文摘Objective Although stressful life events represent an etiologic factor of mental health problems in adolescents, few studies have been conducted to address mechanisms linking the stress-psychopathology relation. The present study was designed to examine coping as a mediate factor on the relationship between stressful life events and symptoms of anxiety and depression. Methods The participants were 13 512 students from eight cities of China, who participated in a school-based survey. Data were collected by a questionnaire comprising coping, stressful life events, anxiety, and depressive symptoms. As a model, a series of regression equations were used to examine whether coping mediated the association between stressful life events and symptoms of anxiety and depression. Results Each dimension of stressful life events showed significant correlation with anxiety, depression and coping (all P〈0.001). In the model to analyze mediate effects, all standardized coefficients (β) were significant (all P〈0.01), indicating marked mediator effects. Furthermore, negative coping might account for more mediate effects than positive coping on this relationship. Conclusion Coping partially mediated the relationship between stressful life events and mental health during adolescence. This study highlighted an important public health priority for preventive interventions targeting stress-related psychopathology, and for further promoting adolescents' mental health.
文摘AIM: To examine the psychological impact of chronic hepatitis C (CHC) diagnosis in a large cohort of CHC patients as compared with other stressful life events and chronic diseases carrying a risk of life-threatening complications. METHODS: One hundred and eighty-five outpatients with compensated CHC were asked to self-grade, using a 100-mm visual analogue scale (VAS), the degree of stress caused by the learning of CHC diagnosis and the perceived severity of their disease. Diagnosis-related stress was compared to four other stressful life events and perceived CHC severity was compared to four other common chronic diseases. RESULTS: Learning of CHC diagnosis was considered a major stressful event (mean ± SD scores: 72±25), significantly less than death of a loved-one (89±13, P〈0.0001) and divorce (78 ± 23, P〈0.007), but more than job dismissal (68 ± 30, P〈 0.04) and home removal (26±24, P〈 0.0001). CHC was considered a severe disease (74± 19), after AIDS (94±08, P〈 0.001) and cancer (91± 11, P〈 0.001), but before diabetes (66±23, P〈0.001) and hypertension (62±20, P〈0.001). Perceived CHC severity was not related to the actual severity of liver disease, assessed according to Metavir fibrosis score. In multivariate analysis, diagnosisrelated stress was related to perceived disease severity (P〈0.001), trait anxiety (P〈 0.001) and infection through blood transfusion (P〈 0.001). CONCLUSION: Our results show the considerable psychological and emotional burden that a diagnosis of CHC represents, even in the absence of significant liver disease. They should be taken into account when announcing a diagnosis of CHC in order to reduce its negative effects.
文摘Mechatronic products usually endure the variable stress spectrum when they operate in certain operational condition and environmental condition, which obey the Weibull distribution. In accordance with the features of mechatronic product, this paper analyzes the failure mode, its corresponding sensitive stress and the design principles of life testing profiles. Based on the above analyses, this paper presents a synthetic stress life testing method based on the hybrid Weibull distribution and its statistical method under variable stress spectrum to evaluate the reliability and life indices of mechatronic products. Because the mechatronic products have many characteristics such as high price, long life and small testing samples, the synthetic stress life testing method under variable load spectrum can simulate the real various spectra, decrease the life testing time and reduce the testing samples. So it is effective to carry out the life testing to mechatronic products. The application results of hydraulic pumps indicate that this method can easily handle the experimental data under variable amplitude spectrum, obtain the high precision parameters point estimation and confidence interval estimation and reduce the testing cost greatly.
文摘Through the failure mechanism analysi s and simulation test of a certain kind of detonator,this paper confirms the str ess level of the stepping stress acceleration life test of the detonator,and t hen e stablishes the data processing mathematical model and storage life forecasting m ethod.At last,according to the result of the stepping stress acceleration lif e test of the detonator,this paper forecasts the reliable storage life of the detonator under the normal stress level.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51575147)the Science Funds for the Young Innovative Talents of HUST(Grant No.201507)
文摘Tool wear has an important influence on the residual stress distribution on the machined surface.Also,it will influence the fatigue life of finished workpiece. In this research,the hard turning process of hardened die steel Cr12 MoV was studied by using PCBN tool with considering tool wear. Based on the numerical treatment of residual stress,the dispersion and distribution curves of different tool wear were fitted,and the influence mechanism of tool wear on the residual stress distribution of machined surface was analyzed.Based on the theory of fatigue mechanics and mathematical statistics,the mathematical model for difference of stress dispersion and fatigue life was established. The rotating and bending tests were carried out on the standard parts after cutting process for the workpiece. The influence of tool wear on fatigue life was revealed by fracture surface morphology and fatigue life study. The results provide theoretical support for control of residual stress and the fatigue property of the machined surface under the actual working conditions.
文摘The design and sizing of new mechanical components which are intended to operate under cyclic loads often require an acceptable level of confidence that the components will meet pre-defined fatigue strength objectives for crack initiation. For loads with multiple amplitudes and mean values, models based on Palmgren-Miner’s linear cumulative damage hypothesis and on multiple S/N curves (stress-no. cycles) are widely used in estimations for the duration of crack initiation. In this paper a procedure for generating S/N curves for multiple stress ratios by interpolation or extrapolation from the data available for two such curves is proposed. At any number of cycles, the stress for crack initiation is calculated from the far field macroscopic stresses of the known curves using Dang Van fatigue criterion and microscopic stresses evaluated at the grain level. An algorithm is presented for uniaxial loading and results verifications against curves established from laboratory tests with elastic and plastic stresses are shown and discussed for notched and un-notched specimens.
基金Sponsored by the National Science and Technology Major Project(Grant No.2017-VI-0002-0071)。
文摘A fourth generation single crystal(SC)nickel based cast superalloy DD15 with 1%Ru,3%Ru,5%Ru was prepared using vacuum induction single crystal furnace in order to optimize the properties and cost of DD15 alloy.The exposure experiment of three alloys was conducted at 1100℃for 1000 h.The stress rupture properties tests were performed at 1100℃temperature and 137 MPa pressure.The composition optimization of Ru element in DD15 alloy had been studied.It was found that the alloys with different Ru contents all consist of cuboidalγ′phase embedded coherent inγphase.Theγ′phase of the alloy all has a size of about 300-500 nm and a volume content of more than sixty percent.The dimension ofγ′precipitates is reduced and uniform with increase of Ru content.Ru element can reduce the distribution ratio of high melting point element,so the microstructural stability is enhanced with Ru content increasing.No topologically close-packed(TCP)phase precipitated in the 5%Ru alloy even after 1000 h exposure.The stress rupture life of the alloy is significantly improved as Ru content rising.The raft breadth decreases slightly as Ru content increases.The specimen with 1%Ru and 3%Ru exhibits the presence of TCP phases and without TCP phases precipitated in fracture specimen with 5%Ru.The density and integrity ofγ/γ′interfacial dislocation network increase as Ru content of the alloy rises.
文摘The paper calculated the temperature and stress fields of 1000 MW ultra-supercritical steam turbine rotors which start in cold condition using the finite element calculation program (ANSYS). After getting rotor stress field, the paper use the general slope method to estimate the low cycle fatigue life loss, the rest of the conditions can be calculated in this method.
文摘In this study, fatigue tests under different R ratios were conducted on the AZ61 Mg alloy to investigate its fatigue lifetimes and fatigue crack growth (FCG) behavior. The fracture surface of the failed specimens was investigated using a scanning electron microscope to study the size of the intermetallic compounds from which the pioneer fatigue crack initiated and led to the final failure of the specimen. To determine the maximum size of the intermetallic compounds existing within the cross section of the specimen at higher risk, Gumbel’s extreme-value statistics were utilized. In the present study, the intermetallic compounds contained within the specimen were assumed to be the initial cracks existing in the material before the fatigue tests. A modified linear elastic fracture-mechanics parameter, M, proposed by McEvily et al., was used to analyze the short FCG behavior under different stress ratios, R. The relation between the rate of FCG and M parameter was found to be useful and appropriate for predicting the fatigue lifetimes under different R ratios. Moreover, the probabilistic stress-fatigue life (P-S-N) curve of the material under different R ratios could be predicted with this method, which utilizes both the FCG law and a statistical distribution of sizes of the most dangerous intermetallic compounds. The evaluated results were in good agreement with the experimental ones. This correspondence indicates that the estimation method proposed in the present study is effective for evaluation of the probabilistic stress-fatigue life (P-S-N) curve of the material under different R ratios.
文摘Many studies about the health problems of persons with physical disabilities have been performed, however few studies have focused on the life circumstances of persons with physical disabilities. This study aimed to clarify the relationship between stress and the life circumstances of persons with congenital physical disabilities who must use wheelchairs. The participants were 70 individuals who used the services of care workers employed by welfare service business offices. Participants used wheelchairs. In addition, those participants who used a standard manual wheelchair were not able to operate it alone. Participants were required to answer a two-part questionnaire with questions about factors related to basic lifestyle and stress, and about life factors related to the stress of individuals with physical disabilities. No significant relationship between lifestyle and stress was found in either males or females. Most persons with congenital physical disabilities using wheelchairs had some kind of stress in daily life. In particular, significantly more level of stress was found in females (90%) than that in males (65%). Levels of stress according to life factor differed between males and females. The most dramatic gender difference was that the level of stress caused by the mental or mind factor in females was significantly higher than that in males (p < 0.05). Most persons who must use wheelchairs have stress resulting from daily life, and in particular, females experience more mental stress than males.
文摘Introduction: Disputativeness and incitement are one of the consequences of the posttraumatic stress disorder which causes intimacy reduction in veteran wives. This study was done with the aim of expressing the veteran posttraumatic stress disorder wives. Method: This qualitative study was done by qualitative content analysis method and 14 participants took part in this study who were all PTSD veteran wives in Golestan province in Iran. Data was gathered by semi-structured interview and by purposive sampling and was continued to the data well saturated. Data analysis was continuously done at the same time as collecting the data. Findings: The main theme and the eleven subtheme included: 1) Entanglement with wife condition: Not willing to have medicine treatment, frequent hospitalized, increasing the problems as the age goes up medicine, dependency on taking medicine, unpredictable wife behavior;2) life erosion: Living along with fear, lost life;3) stressful atmosphere in the house: Physical fight, unsecured feeling in the house, sensitive to noise;4) being worry about future: Hopelessness, spoiled life. These were the main points of this study which cause the unsecured atmosphere for the families. Conclusion: Veteran in ability in controlling their anger causes emotional problems, intimacy decreasing and marriage dissatisfaction, anxiousness and being worry about future. Social and family supports such as consulting services, informative and educational systems have an important role in wives compatibility and life promotion.
文摘The aim of this study is to investigate the relationship between life orientation and cognitive emotion regulation with job stress. On this basis, a sample of 100 employees working in Guilan Education Office was used and research hypotheses were examined by job stress, life orientation and cognitive emotion regulation questionnaires. The results of this study indicate that job stress has a significant relationship with life orientation (-0.32), self-blame (0.25), rumination (-0.36), positive refocusing (0.25), positive refocusing on program (-0.21), positive reappraisal (-0.28), catastrophizing (-0.39) and other blames (-0.25). Furthermore, life orientation and cognitive regulation could explain 22% variances in respondents’ job stress. This finding indicates that more positive life orientation and subsequent decrease of emotion-regulation-related disorders will lead to less job stress.
基金Shanghai Municipal Natural Science Foun-dation (NO.09ZR1413000)Undergraduate Education High-land Construction Project of ShanghaiKey Technology R&D Program of Shanghai Municipality (No.08160510600)
文摘To estimate the life of vacuum fluorescent display (VFD) more accurately and reduce test time and cost, four constant stress accelerated life tests (CSALTs) were conducted on an accelerated life test model. In the model, statistical analysis of test data is achieved by applying lognormal function to describe the life distribution, and least square method (LSM) to calculate the mean value and the standard deviation of logarithm. As a result, the accelerated life equation was obtained, and then a self-developed software was developed to predict the VFD life. The data analysis results demonstrate that the VFD life submits to lognormal distribution, that the accelerated model meets the linear Arrhenius equation, and that the precise accelerated parameter makes it possible to acquire the life information of VFD within one month.
基金supported by the National Natural Science Foundation of China(71401134 71571144+1 种基金 71171164)the Program of International Cooperation and Exchanges in Science and Technology Funded by Shaanxi Province(2016KW-033)
文摘Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality criteria.Finally, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.
文摘Purpose: This study is aimed at comparing the level of occupational stress, ways of coping and the quality of life among nurses. Methods: Descriptive explanatory design was used with 278 nurses working in King Abdul Aziz Hospital in Jeddah, Mental Health Hospital in Jeddah, and Dr. Suleiman Fakeeh Hospital in Jeddah. Findings: Psychiatric nurses experience greater occupational stress than general nurses (p = 0.001). There was no statistically significant difference between the psychiatric and general nurses in relation to coping strategies (p = 0.38). Conclusion: Healthcare institutions should adapt stress evaluation and coping models specific to their unit. Practical Implication: Implementation of programs in each healthcare unit to educate nurses how to deal with work stressors and their negative effects.