Coping as a Mechanism Linking Stressful Life Events and Mental Health Problems in Adolescents

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.

Psychological impact of chronic hepatitis C:Comparison with other stressful life events and chronic diseases

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.

SYNTHETIC STRESSLIFE TESTING OF MECHATRONIC PRODUCTS UNDER VARIABLE STRESS SPECTRUM

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.

Hardness-Based Non-destructive Method for Developing Location Specific S-N Curves for Fatigue Life Evaluation

This paper first describes the importance of using location specific S-N curves for fatigue damage assessment of existing steel structures. It discusses the existing concepts and methods for developing S-N curves using empirical formulae and monotonic strength parameters, such as the ultimate tensile strength and hardness. It also discusses relationships among these monotonic parameters. Then it presents formulae for developing hardness-based full range S-N curves for medium strength steels. The formulae are verified using experimental data obtained from both monotonic and cyclic testing. Finally, it describes the advantages of these hardness-based formulae for developing location specific S-N curves as hardness testing is a non-destructive test which can be carried out on specific locations in structures.

Detonator stepping stress acceleration life test

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.

Parameter Estimation Based on Censored Data under Partially Accelerated Life Testing for Hybrid Systems due to Unknown Failure Causes

In general,simple subsystems like series or parallel are integrated to produce a complex hybrid system.The reliability of a system is determined by the reliability of its constituent components.It is often extremely difficult or impossible to get specific information about the component that caused the system to fail.Unknown failure causes are instances in which the actual cause of systemfailure is unknown.On the other side,thanks to current advanced technology based on computers,automation,and simulation,products have become incredibly dependable and trustworthy,and as a result,obtaining failure data for testing such exceptionally reliable items have become a very costly and time-consuming procedure.Therefore,because of its capacity to produce rapid and adequate failure data in a short period of time,accelerated life testing(ALT)is the most utilized approach in the field of product reliability and life testing.Based on progressively hybrid censored(PrHC)data froma three-component parallel series hybrid system that failed to owe to unknown causes,this paper investigates a challenging problem of parameter estimation and reliability assessment under a step stress partially accelerated life-test(SSPALT).Failures of components are considered to follow a power linear hazard rate(PLHR),which can be used when the failure rate displays linear,decreasing,increasing or bathtub failure patterns.The Tempered random variable(TRV)model is considered to reflect the effect of the high stress level used to induce early failure data.The maximum likelihood estimation(MLE)approach is used to estimate the parameters of the PLHR distribution and the acceleration factor.A variance covariance matrix(VCM)is then obtained to construct the approximate confidence intervals(ACIs).In addition,studentized bootstrap confidence intervals(ST-B CIs)are also constructed and compared with ACIs in terms of their respective interval lengths(ILs).Moreover,a simulation study is conducted to demonstrate the performance of the estimation procedures and the methodology discussed in this paper.Finally,real failure data from the air conditioning systems of an airplane is used to illustrate further the performance of the suggested estimation technique.

Research on the Development Trend of Urbanization of Rural Migrant Workers from the Perspectives of Health and Life Stress

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.

Early Life Stress as Factor for Use of Psychoactive Substances: Integrative Review

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.

Psychosocial factors affecting the etiology and management of type 1 diabetes mellitus:A narrative review

Type 1 diabetes(T1D)is one of the most common chronic diseases in children and adolescents worldwide.Its etiopathogenesis results from the interplay of genetic and environmental variables.Among the latter,psychological stress has been implicated in disease onset as well as disease management.Various studies,including large population-based studies,have highlighted the role of stressful life events in the etiopathogenesis of T1D.In this article,we also emphasize the importance of attachment in the early child-caregiver relationship,which can be seen as a measure of the quality of the relationship and is crucial for stress and emotional regulation.It serves as a model for all subsequent relationships in one’s life.We summarize some of the few studies performed in the field of attachment and T1D etiopathogenesis or management.T1D management demands a lifelong therapeutic regimen to prevent acute and chronic complications.In addition to psychological stress,psychological factors such as family functioning,developmental adjustment,autonomy,mental health problems and other factors have been found to relate to metabolic control.Psychological factors need to be understood not as a single directional causality-based principle but as a dynamic bi-or multidirectional system that is affected by the normal developmental transitions of childhood and adolescence.

Music in depression: Neural correlates of emotional experience in remitted depression

AIM: To investigate neural and behavioral correlates of emotional experiences as potential vulnerability markers in remitted depression. METHODS: Fourteen remitted participants with a history of major depression and fourteen closely matched healthy control participants took part in the study. We used two psychiatric interviews(Hamilton Depression Rating Scale, Montgomery-Asberg Depression Rating Scale) and one self-report scale(Beck Depression Inventory) to assess remission. Healthy control participants were interviewed by an experienced psychiatrist to exclude those who showed any current or lifetime psychiatric or neurological disorders. To explore psychosocialand cognitive-interpersonal underpinnings of potential vulnerability markers of depression, early life stress, coping styles and alexithymia were also assessed. We induced pleasant and unpleasant emotional states using congruent combinations of music and human emotional faces to investigate neural and behavioral correlates of emotional experiences; neutral stimuli were used as a control condition. Brain responses were recorded using functional magnetic resonance imaging. Behavioral responses of pleasantness, arousal, joy and fear were measured via button-press inside the resonance imaging scanner. RESULTS: The mean age of the sample was 54.9(± 11.3) years. There were no differences between remitted depressed(RD)(n = 14; 9 females and 5 males) and healthy participants(n = 14; 8 females and 6 males) regarding age, current degree of depression, early life stress, coping styles and alexithymia. On a neural level, RD participants showed reduced activations in the pregenual anterior cingulate cortex(pg ACC) in response to pleasant [parameter estimates:-0.78 vs 0.32; t(26) =-3.41, P < 0.05] and unpleasant [parameter estimates:-0.88 vs 0.56; t(26)=-4.02, P < 0.05] emotional stimuli. Linear regression analysis revealed that pg ACC activity was modulated by early life stress [β =-0.48; R2 = 0.23, F(1,27) = 7.83, P < 0.01] and taskoriented coping style [β = 0.63; R2 = 0.37, F(1,27) = 16.91, P < 0.001]. Trait anxiety modulated hippocampal responses to unpleasant stimuli [β = 0.62; R2= 0.38, F(1,27) = 15.95, P < 0.001]. Interestingly, in their reported experiences of pleasantness, arousal, happiness and fear in response to pleasant, unpleasant and neutral stimuli, RD participants did not differ significantly from healthy control participants. Adding trait anxiety or alexithymia as a covariate did not change the results.CONCLUSION: The present study indicates that, in euthymic individuals, depression history alters neural correlates, but not the subjective dimension of pleasant and unpleasant emotional experiences.

Influence of Ru Content on Microstructural Stability and Stress Rupture Property of DD15 Alloy

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.

Gene×environment interaction in major depressive disorder

Major depressive disorder(MDD)is a multifactorial disorder,where multiple susceptibility genes interact with environmental factors,predisposing individuals to the development of the illness.In this article,we reviewed different gene×environment interaction(G×E)studies shifting from a candidate gene to a genome-wide approach.Among environmental factors,childhood adversities and stressful life events have been suggested to exert crucial impacts on MDD.Importantly,the diathesis-stress conceptualization of G×E has been challenged by the differential susceptibility theory.Finally,we summarized several limitations of G×E studies and suggested how future G×E studies might reveal complex interactions between genes and environments in MDD.

Childhood Adversities Associated with Eating Disorders Reported by Adults

Background: It has been suggested that childhood events increase the risk of suffering from an eating disorder (ED) in adolescence or young adulthood. Our study here aimed at investigating whether there was an association between stressful childhood events and eating disorders later in life. Methods: Our population-based study was a part of the HeSSup (The Health and Social Support) postal survey in 2003, a follow-up survey with a random sample of working-aged subjects drawn from the Finnish Population Register in 1998. Participants in this study reported having been suffering from ED (N = 374), while controls (N = 18,639) reported no history of eating disorder in the questionnaire both in 1998 and 2003. The questionnaire included six questions related to childhood adversities. Results: Each childhood stressor increased the risk of developing ED cumulatively (one adversity OR 1.7 versus all six OR 8.3). Intrafamiliar conflicts (OR 2.0), being afraid of a family member (OR 1.5) or long-term illnesses in the family (OR 1.4) increased the ED-risk statistical significantly. Conclusion: Children exposed to stress are more likely to suffer from eating disorders as adults than those not exposed.

The Influence of Initial Management and Family Stress on Metabolic Control in Children with Type 1 Diabetes

The aim was to assess whether temporal changes in the initial management for children diagnosed with type 1 diabetes over a ten year period affected metabolic control two years after diagnosis. A further aim was to investigate if social factors, registered at diagnosis, had an impact on metabolic control two years after diagnosis. During the years 1997-2006, 247 children and adolescents were diagnosed with type 1 diabetes at a University Hospital in Sweden. The analysed data included HbA1c, pH at diagnosis, initial intravenous insulin infusion and length of hospital stay at diag?nosis, subcutaneous insulin type, number of diabetes check-up visits, emergency visits, re-admissions and social factors. Length of hospital stay decreased significantly over the ten year period. Neither hospital stay nor differences in insulin treatment was significantly correlated with children’s metabolic control over time. Length of hospital stay was not re?lated with families’ social stress situation. However, girls in families with more family stress at the time of diagnosis had higher HbA1c during follow-up than girls with less family stress or boys. Factors of importance for the child’s long-term metabolic control need to be further investigated so the initial management can be tailored to each individual family’s needs. This would imply an effective utilization of both families’ and health care resources.

STATISTICAL INFERENCE OF WEIBULL DISTRIBUTION FOR TAMPERED FAILURE RATE MODEL IN PROGRESSIVE STRESS ACCELERATED LIFE TESTING

In this note,the tampered failure rate model is generalized from the step-stress accelerated life testing setting to the progressive stress accelerated life testing for the first time.For the parametric setting where the scale parameter satisfying the equation of the inverse power law is Weibull,maximum likelihood estimation is investigated.

Association between Perceived Stressfulness of Stressful Life Events and the Suicidal Risk in Chinese Patients with Major Depressive Disorder

Background： Patients with major depressive disorder （MDD） usually have high risk of suicidality. Few studies have investigated the effects of stressful life events （SLEs） on the risk of suicide in Chinese patients who have developed MDD. This study aimed to investigate the impact of SLEs on suicidal risk in Chinese patients with MDD. Methods： In total, 1029 patients with MDD were included from nine psychiatric hospitals to evaluate the impact of SLEs on suicidal risk. Patients fulfilling the Mini-International Neuropsychiatric Interview （MINI） criteria for MDD were included in the study. Patients were excluded if they had lifetime or current diagnoses of psychotic disorder, bipolar disorder, and alcohol or substance dependence. Depressive symptoms were assessed by the 17-item Harnilton Depression Scale （HAMD-17）. The suicidal risk of MDD patients was determined by the suicide risk module of MINI. SLEs were assessed by the Life Events Scale. Results： No gender difference was found for suicidal risk in MDD patients. Patients with suicidal risk had younger ages, lower education levels, more drinking behavior, and lower marriage rate, and fewer people had child and more severe depressive symptoms than nonsuicidal risk group. High-level perceived stressfulness （HPS） and number of SLEs that patients were exposed to were significantly greater in patients with suicidal risk than patients without. In multivariate logistic analysis, HPS of SLEs （odds ratio [OR] = 1.54, 95% confidence interval [C1]： 1.16-2.05, P = 0.003） and depressive symptoms （OR = 1.08.95% CI： 1.05-1.11, P 〈 0.001 ） were associated with suicidal risk even after adjustment of gender, age, marriage, drinking behavior, and childless. Conclusions： HPS of SLEs is associated with suicide risk in Chinese patients with MDD. Further suicide prevention programs targeting this risk factor are needed. Trial Registration： ClinicalTrials.gov： NCT02023567; https：//clinicaltrials.gov/ct2/show/NCTO2023567？term=NCTO2023567＆rank=l.

Stressful life events,psychosocial health and general health in preschool children before age 4

Background The impact of stressful life events(SLEs)in early childhood is often ignored.We aimed to examine longitudinal associations between SLEs and psychosocial and general health in preschool children.Methods Twelve SLEs occurring before the age of 24 months were assessed and categorized by frequency(no events,1-2 SLEs,and>2 SLEs)and overall tension(no events,low,and high)(n=1431).Psychosocial and general health were meas-ured three times at the age of 24,36 and 45 months.The associations were examined by logistic regression models using generalized estimating equations to handle repeated measurements.Results Half(48.4%)of the families experienced SLEs,and 23.8%perceived high-tension SLEs before the children were aged 24 months.Gender differences were observed in the association between SLEs and psychosocial health.Compared to girls without SLEs,girls who experienced>2 SLEs[OR=3.31,95%confidence interval(CI)2.05-5.35]or high-tension SLEs(OR=3.01,95%CI 2.07-4.39)had higher odds of psychosocial problems from 24 to 45 months.The odds ratios in boys were 2.10(95%CI 1.36-3.24)and 1.47(95%CI 1.06-2.03),respectively.Moreover,only girls'risk of psychosocial problems increased after experiencing 1-2 SLEs(OR=2.15,95%CI 1.54-3.00)or low-tension SLEs(OR=1.90,95%CI 1.31-2.74).Regarding general health,children who experienced>2 SLEs(OR=1.96,95%CI 1.21-3.18)and high-tension SLEs(OR=1.60,95%CI 1.12-2.28)had higher odds of poor general health from 24 to 45 months.Conclusions The findings emphasized that young children's psychosocial and general health can be impacted by experienc-ing SLEs in early childhood.Attention and adequate support for families experiencing SLEs are needed to minimize the potential negative effect of SLEs on child health,particularly in girls.

Statistical analysis of dependent competing risks model in constant stress accelerated life testing with progressive censoring based on copula function

In this paper, we consider the statistical analysis for the dependent competing risks model in theconstant stress accelerated life testing (CSALT) with Type-II progressive censoring. It is focusedon two competing risks from Lomax distribution. The maximum likelihood estimators of theunknown parameters, the acceleration coefficients and the reliability of unit are obtained by usingthe Bivariate Pareto Copula function and the measure of dependence known as Kendall’s tau.In addition, the 95% confidence intervals as well as the coverage percentages are obtained byusing Bootstrap-p and Bootstrap-t method. Then, a simulation study is carried out by the MonteCarlo method for different measures of Kendall’s tau and different testing schemes. Finally, a realcompeting risks data is analysed for illustrative purposes. The results indicate that using copulafunction to deal with the dependent competing risks problems is effective and feasible.

Association of psychological stress with wives’hypertension across over 10 million Chinese married female population aged 20-49 years

Background:Psychological stress has been reported to be a potential risk factor for hypertension among females,but it remains unclear whether spousal chronic stress levels alter the risk of hypertension among women.We examined the associations between stress within the family and hypertension among married women.Methods:Reproductive-aged women who were planning for pregnancy and their husbands were recruited from the National Free Pre-pregnancy Checkup Projects(NFPCP)across 31 provinces in China in 2016 and 2017.Perceived stress of wives or husbands was measured with a 5-point Likert-type scale,and assessed from three domains:work/life-related stress,economic stress,and overall stress.Multivariable-adjusted logistic regression models were used to assess the associations between stress status and the prevalence of hypertension.Results:Of 10,027,644 couples,261,098(2.60%)women had hypertension.The results showed that higher stress levels among themselves or their husbands were associated with a higher prevalence of hypertension in women(P_(for trend)<0.001).Compared with non-stressed participants,female participants with the highest stress themselves were at a greater risk of hypertension,with adjusted odds ratio(OR)of 1.31(95%confidence interval[CI]:1.25-1.37);and compared with participants whose husbands had no stress,those whose husbands had the highest stress level were at a higher risk of hypertension with adjusted OR of 1.24(95%CI:1.20-1.29).Moreover,compared with non-stressed status for both couples,only-wife-stressed,only-husband-stressed,and both-stressed couples were found to be significantly associated with increased risks of wives’hypertension,with adjusted ORs of 1.28(95%CI:1.25-1.31),1.19(95%CI:1.17-1.21),and 1.28(95%CI:1.26-1.31),respectively.Conclusion:Moderate to severe stress in both spouses might be associated with female hypertension prevalence,which highlights the importance of paying attention to the psychological stresses of couples within the family.

A modern and robust methodology for modeling anisotropic creep characteristics of Ni-based DS and SC superalloys

According to more recent work, the Wilshire equations have shown good prediction accuracy in a wide range of materials and stress-temperature conditions, particularly in extrapolation of short term results to long term predictions. In the current paper, this methodology was further developed for modeling anisotropic creep characteristics （i.e. minimum creep strain /~n, stress rupture life q and time to a specified strain t~） of four typical Ni-based directionally solidified （DS） and single crystal （SC） superalloys, where a simple orientation factor related to the ultimate tensile strength （UTS） was introduced. The application of these simplistic approaches showed that the anisotropic creep characteristics in a wide range of stress-temperature conditions can be accurately simulated. Meanwhile, during the application of the modified Wilshire equations, break points occurring at the specified stress levels agree well with the transition of creep deformation mechanisms occurring in different stress regions, which provides confidence for using this method.