Strain-hardening and suppression of shear-banding in rejuvenated bulk metallic glass.

Strain-hardening (the increase of flow stress with plastic strain) is the most important phenomenon in the mechanical behaviour of engineering alloys because it ensures that flow is delocalized, enhances tensile ductility and inhibits catastrophic mechanical failure1,2. Metallic glasses (MGs) lack the crystallinity of conventional engineering alloys, and some of their properties-such as higher yield stress and elastic strain limit3-are greatly improved relative to their crystalline counterparts. MGs can have high fracture toughness and have the highest known 'damage tolerance' (defined as the product of yield stress and fracture toughness)4 among all structural materials. However, the use of MGs in structural applications is largely limited by the fact that they show strain-softening instead of strain-hardening; this leads to extreme localization of plastic flow in shear bands, and is associated with early catastrophic failure in tension. Although rejuvenation of an MG (raising its energy to values that are typical of glass formation at a higher cooling rate) lowers its yield stress, which might enable strain-hardening5, it is unclear whether sufficient rejuvenation can be achieved in bulk samples while retaining their glassy structure. Here we show that plastic deformation under triaxial compression at room temperature can rejuvenate bulk MG samples sufficiently to enable strain-hardening through a mechanism that has not been previously observed in the metallic state. This transformed behaviour suppresses shear-banding in bulk samples in normal uniaxial (tensile or compressive) tests, prevents catastrophic failure and leads to higher ultimate flow stress. The rejuvenated MGs are stable at room temperature and show exceptionally efficient strain-hardening, greatly increasing their potential use in structural applications.

[Diagnosis and treatment procedures and health management for patients with hereditary angioedema].

As a recognized rare and highly fatal disease, hereditary angioedema (HAE) is difficult to diagnose and characterized by recurrent edema involving the head, limbs, genitals and larynx, etc. Diagnosis of HAE is not difficult. However, low incidence and lack of clinical characteristics lead to difficulty of doctors on timely diagnosis and correct intervention for HAE patients. Therefore, it is crucial to improve the awareness of this disease and prevent its recurrence. for HAE patients. In view of absent cognition of doctors and the general public on HAE, patients often suffer from sudden death or become disabled due to laryngeal edema which cannot be treated in time. Thus, based on the Internet mobile terminal platform, the team set up an all-day rapid emergency response system which is provided for HAE patients by setting up "one-click help". The aim is to offer optimization on overall management of HAE and designed the intelligent follow-up management to provide timely assistance and specialized suggestion for patients with acute attacks.

[Baseline survey of psychosocial factors levels and their health effects in a cohort study of natural gas field workers].

Objective: To investigate the level of psychosocial factors in workplace and their health effects among workers in a natural gas field. Methods: A prospective and open cohort of natural gas field workers was established to study the level of workplace psychosocial factors and their health effects, with a follow-up every 5 years. In October 2018, a cluster sampling method was used to conduct a baseline survey of 1737 workers in a natural gas field, including a questionnaire survey on demographic characteristics, workplace psychosocial factors and mental health outcomes, physiological indicators such as height and weight, and biochemical indicators such as blood routine, urine routine, liver function and kidney function. The baseline data of the workers were statistically described and analyzed. The psychosocial factors and mental health outcomes were divided into high and low groups according to the mean score, and the physiological and biochemical indicators were divided into normal and abnormal groups according to the reference range of normal values. Results: The age of 1737 natural gas field workers was (41.8±8.0) years old, and the length of service was (21.0±9.7) years. There were 1470 male workers (84.6%). There were 773 (44.5%) high school (technical secondary school) and 827 (47.6%) college (junior college) graduates, 1490 (85.8%) married (including remarriage after divorce), 641 (36.9%) smokers and 835 (48.1%) drinkers. Among the psychosocial factors, the detection rates of high levels of resilience, self-efficacy, colleague support and positive emotion were all higher than 50%. Among the mental health outcomes evaluation indexes, the detection rates of high levels of sleep disorder, job satisfaction and daily stress were 41.82% (716/1712), 57.25% (960/1677) and 45.87% (794/1731), respectively. The detection rate of depressive symptoms was 22.77% (383/1682). The abnormal rates of body mass index (BMI), triglyceride and low density lipoprotein were 46.74% (810/1733), 36.50% (634/1737) and 27.98% (486/1737), respectively. The abnormal rates of systolic blood pressure, diastolic blood pressure, uric acid, total cholesterol and blood glucose were 21.64% (375/1733), 21.41% (371/1733), 20.67% (359/1737), 20.55% (357/1737) and 19.17% (333/1737), respectively. The prevalence rates of hypertension and diabetes were 11.23% (195/1737) and 3.45% (60/1737), respectively. Conclusion: The detection rates of high level psychosocial factors in natural gas field workers are high, and their effects on physical and mental health remain to be verified. The establishment of a cohort study of the levels and health effects of psychosocial factors provides an important resource for confirming the causal relationship between workplace psychosocial factors and health.

[The incidence and time distribution of early transient intraocular pressure elevation after penetrating canaloplasty].

Objective: To report the incidence and time distribution of early transient intraocular pressure (IOP) elevation after penetrating canaloplasty. Methods: Retrospective case series study. Data of patients treated by penetrating canaloplasty for glaucoma in the Eye Hospital of Wenzhou Medical University from June 2015 to March 2020 were collected. Early transient IOP elevation was defined as an increase of IOP to over 21 mmHg on the first week to the third month after surgery followed by a decrease to 21 mmHg or less within 3 months. Main outcome measures included IOP, quantity of medication use, the occurrence time and duration of IOP elevation. Generalized estimating equations were used for statistical analysis, and measurement data with non-normal distribution was represented as M (Q1, Q3). Results: A total of 277 patients (315 eyes) achieved 360-degree catheterization of the canal successfully, and 299 eyes (94.9%) completed the postoperative 6-month follow-up. Thirty-four eyes (10.8%) had persistently high IOP, so the surgical treatment failed in them. Consequently, 234 patients (265 eyes) were enrolled in the analyses, including 161 males (184 eyes) and 73 females (81 eyes). The median age was 42 (26, 54) years, the mean preoperative IOP was (37.7±11.1) mmHg, and the mean number of drugs used was 3 (2, 4). The incidence of early transient IOP elevation was 43.0% (114/265) in all enrolled eyes, 42.7% (35/82) in eyes with primary open angle glaucoma, 37.8% (17/45) in eyes with primary angle closure glaucoma, 27.7% (13/47) in eyes with congenital glaucoma and 53.8% (49/91) in eyes with secondary glaucoma. The IOP began to increase on the first to fourth week in 91.2% (104/114) of eyes with early transient IOP elevation and reached the peak [21.3 mmHg to 54.8 mmHg; mean, (32.4±8.2) mmHg] in 88.6% (101/114) on the first to fifth week after surgery. The IOP elevation lasted for no more than 4 weeks in 69.3% (79/114) of eyes. Conclusions: Over 40.0% of patients with penetrating canaloplasty may experience postoperative transient IOP elevation. The incidence is relatively high in secondary glaucoma but low in congenital glaucoma. Most of the elevations and peak IOP occur within 1-4 weeks after surgery.

[Prevalence and associated risk factors of pre-hypertension and hypertension in young and middle-aged population in Nanjing].

Objective: To investigate the prevalence and associated risk factors of pre-hypertension and hypertension in young and middle-aged population in Nanjing. Methods: Subjects of the study were those who underwent physical examination in the physical examination center of Nanjing Drum Tower Hospital from 2009 to 2016. The prevalence and risk factors of pre-hypertension and hypertension in young (aged 18-44 years old) and middle-aged people (aged 45-59 years old) were analyzed. Results: A total of 142 857 participants aged 18-59 years old were analyzed. Among them, 64 220 cases in the pre-hypertension group and 13 912 cases in the hypertension group. The prevalence of hypertension was 9.74% (12.51% in males and 5.82% in females). The prevalence of pre-hypertension was 44.95% (53.31% in males and 33.15% in females). In the middle-aged group, the prevalence of pre-hypertension and hypertension were 51.68% and 15.13%, respectively, which was higher than that in the young group (37.95% and 4.13%, respectively). The prevalence of pre-hypertension and hypertension in 2013-2016 was 45.37% and 10.65%, respectively, which was higher than that in 2009-2012(44.52% and 8.78%). In addition, the prevalence of abnormal blood glucose metabolism, abnormal blood lipid metabolism and abnormal glucose and lipid metabolism in the pre-hypertension group was higher than that in the normal blood pressure group, but lower than that in the hypertension group (P<0.001). A logistic regression analysis indicated that age, overweight or obesity, hyperglycemia, hypertriglyceridemia and hypercholesterolemia were risk factors of pre-hypertension in male. Age, overweight or obesity, hyperglycemia, hypertriglyceridemia, hypercholesterolemia and hyper-low density cholesterolemia were associated with hypertension in male and with pre-hypertension and hypertension in female. Conclusions: Middle age, overweight/obesity, elevated fasting plasma glucose, elevated triglyceride and elevated total cholesterol were risk factors of pre-hypertension and hypertension in both men and women. Intervention on the related risk factors should be conducted as early as possible.

[Quality of life of patients with primary open-angle glaucoma based on EQ-5D in Wenzhou].

Objective: To evaluate the quality of life of patients with primary open-angle glaucoma (POAG) and its related factors in Wenzhou. Methods: Cross-sectional analysis. A total of 339 POAG patients diagnosed in the Wenzhou glaucoma progression study conducted in the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical University from March 2014 to October 2019 were included. Quality of life of POAG patients was assessed by EQ-5D including the visual analogue scale (VAS). The effects of gender, age, visual field loss (VFL), family history of glaucoma, hypertension, diabetes, migraine, sleep quality, and amateur exercise on the quality of life were analyzed. The utility value (UV) and VAS score were expressed as the median (P25, P75), and Mann-Whitney U was used for the comparison between two groups. Kruskal-Wallis H was performed to compare the differences among multiple groups. Results: A total of 339 POAG patients were included in the study; 164 were males (48.4%), and 175 were females (51.6%). The mean age was (63±10) years. Thirty-four patients (10.0%) had received medication (including one with combined surgical treatment), while the remaining 305 patients (90.0%) had received no anti-glaucoma treatment. Among the patients, 10.5% (32/305) had no VFL, 68.9% (210/305) had mild VFL, 17.0% (52/305) had moderate VFL, and 3.6% (11/305) had severe VFL. In all patients, the median of UV was 1.000 (1.000, 1.000), the mean of UV was 0.964, and the median of VAS score was 80 (75, 90), the mean of VAS score was 81.58. Anxiety or depression and pain or discomfort occurred in 45.7% (43/94) and 34.1% (32/94), respectively, of POAG patients with decreased UVs, as well as mobility constraints in 13.8 % (13/94) and usual activity constraints in 6.4% (6/94). The median of UV of the eye with a better visual field in the group without VFL or with mild or moderate VFL was 1.000 (1.000, 1.000), and in the group with severe VFL was 1.000 (0.862, 1.000), but there was no significant difference in the UV and the VAS score of the eye with a better visual field among groups with different degrees of VFL (both P>0.05). There was statistically significant difference in the UV among groups with different sleep qualities (H=17.465; P<0.01). Using pairwise comparison, the median of UV of the very good sleep group was 1.000 (1.000, 1.000), significantly different to the slightly poor sleep group 1.000 (0.866, 1.000) (z=3.613; P<0.05). The median of UV in patients with migraine was 1.000 (0.875, 1.000), without migraine 1.000 (1.000, 1.000), and in patients with hypertension was 1.000 (0.875, 1.000), without hypertension 1.000 (1.000, 1.000), and in patients with diabetes was 1.000 (0.875, 1.000), without diabetes was 1.000 (1.000, 1.000), the difference was statistically significant (Z=-2.189, -3.864, -2.417; all P<0.05). The UV was not related to age, gender, family history of glaucoma, amateur exercise, alcohol and tobacco, and history of anti-glaucoma medication (all P>0.05). Conclusions: VFL is related to the UV of POAG patients in Wenzhou. Quality of life in mild POAG patients is good but decrease in advanced POAG patients. Sleep quality, systemic complications and physical or psychological discomfort impact on quality of life in POAG patients. (Chin J Ophthalmol, 2021, 57: 207-214).

[Effect of occupational stress on depression in gas field workers].

Objective: To explore the occurrence level of depressive symptoms and it's influencing factors among gas field workers. Methods: In October 2018, a cross-sectional study was conducted in 1726 gas field workers from a gas field by using cluster sampling method. Questionaire was used to evaluate the individual factors, depressive symptoms, occupational stress factors and stress regulatory factors. The correlation between depressive symptoms and occupational stress was analyzed. Multivariate logistic regression was used to analyze the influencing factors of depressive symptoms. Results: The depressive symptoms score of gas field workers was 12.00 (7.00, 19.00) point. Correlation analysis revealed that depressive symptoms score was positively related to sleep disorders (r=0.598) , effort (r=0.186) , daily tension (r=0.478) , negative affectivity (r=0.565) , social support (r=0.446) and monotony of work (r=0.484) (P<0.01) . And it was negatively related to reward (r=-0.386) , work stability (r=-0.294) , promotion opportunities (r=-0.258) , positive affectivity (r= -0.310) , self-efficacy (r=-0.312) , contral strategy (r=-0.268) , support strategy (r=-0.209) and job satisfaction (r=-0.398) (P<0.01) . Multivariate logistic regression analysis revealed that sleep disorder, high negative affectivity, low support from colleagues, low support from family, high monotony of work and high daily tension were the risk factors for depressive symptoms of gas field worker (OR=3.423, 95%CI: 2.644-4.397; OR=2.847, 95%CI: 2.200-3.683; OR=1.646, 95%CI: 1.215-2.116; OR=1.496, 95%CI: 1.164-1.923; OR=1.578, 95%CI: 1.227-2.303; OR=1.903, 95%CI: 1.480-2.440; P<0.01) . High work stability, high self-efficacy and high job satisfaction were protective factors for depressive symptoms of gas field workers (OR=0.752, 95%CI: 0.591-0.958; OR=0.590, 95%CI: 0.465-0.749; OR=0.718, 95%CI: 0.516-0.999; P<0.05) . Conclusion: Occupational stress factors have a great influence on the depressive symptoms of gas field workers. Increased work stability, self-efficacy and job satisfaction could reduce the risk of depressive symptoms.

[Correlation of job monotony and social support on daily hassle: a cross-sectional study based on natural gas field workers].

Objective: To explore the correlation of job monotony and social support on daily hassle. Methods: A convenient sampling survey of demographics characteristics, job monotony, social support and daily hassle was conducted on 1 466 natural gas field workers by questionnaire in October; 2018. Multivariate logistic regression model was used to analyze the correlation of job monotony and social support on daily hassle. Results: The age of 1 466 subjects was (44.47±8.0) years and the length of service was (20.46±5.77) years. There were 258(17.6%), 173(11.8%), 799(54.5%), 120(8.2%) and 116(7.9%) subjects from production and marketing department, processing plant, branch, maintenance department and emergency center respectively. There were 374(25.5%) and 1 092(74.5%) subjects with high and low level of job monotony, and 398(27.1%), 648(44.2%) and 420(28.6%) subjects with high, middle and low level of social support. There were 464(31.7%) and 1 002(68.3%) subjects with high and low daily tension respectively. Compared with the low level of job monotony, the high level of job monotony had a higher risk of daily hassle(OR=4.83,P<0.001), and compared with the high level of social support, the middle and low level of social support had a higher risk of daily hassle(OR=1.25, 2.24,P<0.05). Conclusion: Job monotony and social support were associated with daily hassle.

[Interaction of shift work and psychological capital on abnormal glucose and lipid metabolism among natural gas field workers].

Objective: To explore the interaction between shift work and psychological capital on abnormal glucose and lipid metabolism. Methods: A convenient sampling survey of demographics characteristics, shift work and psychological capital was conducted on 1 415 natural gas field workers by questionnaire in October 2018,and their physiological and biochemical indexes were measured according to standard norms. Multivariate logistic regression model was used to analyze the interaction between shift work and psychological capital on abnormal glucose and lipid metabolism. Results: For 1 415 subjectsthe prevalence of abnormal blood glucose was 21.2%, the prevalence of diabetes was 8.3%.The prevalence of abnormal total cholesterol was 40.4%, the prevalence of hypercholesterolemia was 11.3%.The prevalence of abnormal triglyceride was 41.6%, the prevalence of hypertriglyceridemia was 24.7%.The detection rate of Low-density Lipoprotein was 17.3%, the detection rate of Low-density Lipoprotein was 4.0%, and the detection rate of high-density Lipoprotein was 1.3%. Multiple logistic regression model analysis showed that shift work, the low level of self-efficacy and the low level of optimism was positively associated with abnormal blood glucose, respectively (P<0.05). Shift work was positively associated with abnormal triglyceride (P<0.05). However, there was no interaction between shift work, low self-efficacy, low hope, low resilience, and low optimism on abnormal glucose and lipid metabolism. Conclusion: Shift work was a risk factor of abnormal blood glucose and triglyceride, self-efficacy and optimism were protective factors of abnormal blood glucose. There was no multiplicative interaction between shift work and psychological capital on abnormal glucose and lipid metabolism in the study population.

[Sleep quality and occupational stress relationship analysis of field gas recovery workers].

Objective: To explore the relationship between sleep quality and occupational stress in field gas recovery workers. Methods: In October 2018, cluster sampling method was adopted to conduct cross-sectional survey on 1726 field workers in a gas production oilfield. The individual characteristics, occupational stress factors, stress regulation factors, stress response and sleep quality, social support and coping strategies were evaluated by occupational stress measurement tools and job content questionnaire. Mann Whitney U test and Kruskal Wallis H test were used to compare sleep quality scores between the groups. Spearman rank correlation analysis was used to analyze the correlation between sleep quality and occupational stress, and logistic regression analysis was used to analyze multiple factors. Results: There were significant differences in sleep quality scores among different positions, gender, marital status, age, length of service, smoking and drinking (P<0.05) . There were no significant differences in sleep quality scores between different education levels and work shift groups (P>0.05) . Spearman rank correlation analysis showed that sleep quality score was negatively correlated with job satisfaction, reward, job stability, promotion opportunity, positive emotion, respect, self-esteem, control strategy, support strategy and self-efficacy score (r(s)=-0.361, -0.311, -0.238, -0.261, -0.248, -0.212, -0.139, -0.188, -0.152, -0.226, P<0.01) , and was positively correlated with social support, giving, daily tension, negative emotion, work monotony and depression symptom (r(s)=0.312, 0.279, 0.547, 0.493, 0.429, 0.599, P<0.01) . Compared with the high sleep quality score group, the middle and low sleep quality score groups had lower giving, work monotony, daily tension, depressive symptoms, negative emotions and social support (P<0.01) , while the scores of respect, reward, job satisfaction, positive emotion, self-efficacy, job stability, promotion opportunity, control strategy and support strategy were higher (P<0.01) . Multiple depressive symptoms, high daily tension, high negative emotion and high work monotony were the risk factors for sleep disorders (OR=3.417, 2.659, 2.913, 1.543) . Conclusion: Depressive symptoms, daily tension and negative emotion have great influence on sleep quality of field gas recovery workers.

[Correlation between social support and occupational stress among gas production workers in the field].

Objective: To investigate the level of social support and its correlation with occupational stress among gas production workers in the field. Methods: In October 2018, the cluster sampling method was used to perform a cross-sectional survey for 1726 gas production workers in the field, and related data of these workers were collected, including age, education level, marital status, level of social support, and related factors for occupational stress. A Spearman's rank correlation analysis was used to investigate the correlation between social support and occupational stress, and the levels of occupational stress-related factors were compared between the groups with different social support scores. Results: The gas production workers in the field had a median (25th percentile, 75th percentile) social support score of 24.00 (19.00, 28.00) , and there was a significant difference in social support score between the workers with different posts or work shifts (P<0.01) . Social support score was positively correlated with effort, daily stress, negative emotion, and job routinization (P<0.05) and was negatively correlated with job satisfaction, reward, working stability, and promotion opportunity (P<0.05) . The group with a high social support score had significantly higher scores of effort, job routinization, sleep disorders, and daily stress than the other two groups (P<0.01) , and the group with a low social support score had significantly higher scores of reward, self-efficacy, positive affection, and job satisfaction than the other two groups (P<0.01) . Conclusion: High-level social support plays an important role in alleviating occupational stress and protecting mental health among gas production workers in the field.

[Relationship research among CDH23 gene and the risk of noise-induced hearing loss].

Objective: To explore the relationship among CDH23 gene variation and the risk of noise-induced hearing loss (NIHL) . Methods: The nested case-control study was performed and this study followed a cohort of 6297 noise-exposed workers in a steel factory of Henan province in China from January 1, 2006 to December 31, 2015. In July 2019, subjects whose average hearing threshold were more than 40 dB in high frequency were defined as the case group, and subjects whose average hearing threshold were less than 35 dB in high frequency and less than 25 dB in speech frequency were defined as the control group. A nested case-control study which included 572 subjects was carried out, in which subjects consisted of 286 cases and 286 controls. 18 single nucleotide polymorphisms (SNPs) in CDH23 were selected and genotyped, then we analyzed the association among SNPs in CDH23, haplotypes in CDH23 and NIHL risk. Logistic regression was performed to analyze the main effects of SNPs and the interactions between CNE and SNPs adjusting cumulative noise exposure (CNE) , smoking, drinking, physical exercise and hypertension. Moreover, the association between haplotypes in CDH23 and NIHL risk were also analyzed. We ananlyzed the relationship amongst different SNP groups and NIHL risk using the generalized multifactor dimensionality reduction (GMDR) method. Results: The results suggested that significant associations were observed for rs3802711, rs3752751, rs3752752, rs11592462, rs10762480, rs3747867 for NIHL overall and/or various CNE strata by adjusting CNE, smoking, drinking, physical exercise and blood pressure. For rs3802711, workers exposure to noise carrying the AA/GA genotype of rs3802711 increased risk of NIHL than those carrying GG genotype (OR=3.121; 95%CI:1.054-9.239, P=0.035) in overall; In the stratified analysis of CNE (>97 dB (A) ·year at rs3802711 locus, workers exposure to noise carrying GA genotype (OR=2.056; 95%CI:1.226~3.448, P=0.006) and GA+AA/GA genotype (OR=2.221; 95%CI:1.340~3.681, P=0.002) increased NIHL risk. For rs11592462, workers exposure to noise carrying the GG genotype of rs11592462 increased risk of NIHL than those carrying CC genotype in overall (OR=3.951; 95%CI:1.104-14.137, P=0.04) ; workers exposure to noise carrying the GG genotype of rs11592462 increased risk of NIHL than those carrying CG+CC genotype in overall (OR=4.06; 95%CI:1.145-14.391, P=0.03) . After adjusting CNE, smoking, drinking, physical exercise and blood pressure, the haplotypes of CDH23 rs1227049, rs10999947, rs3752752, rs3752751, rs10762480, rs3802711, rs11592462, rs10466026, rs4747194, rs4747195 were not associated with the risk of NIHL. GMDR analysis showed no association between SNP combination and NIHL risk after adjusting CNE, smoking, drinking, physical exercise and blood pressure. Conclusion: Gene polymorphisms in CDH23 might associate significantly with the risk of NIHL.

[Association between GSTP1 gene polymorphisms and susceptibility to noise-induced hearing loss].

Objective: To investigate the association between the single nucleotide polymorphisms (SNPS) at rs1695 and rs6591256 in glutathione S-transferase P1 (GSTP1) gene and susceptibility to noise-induced hearing loss in Chinese Han workers exposed to noise. Methods: Using the 1: 1 nested case-control study and taking 6297 workers exposed to noise in a steel plant in Henan province as the cohort study population in July 2019, we screened those who have been exposed to noise for ≥3 years and whose binaural high frequency (3000, 4000, 6000 Hz) average hearing threshold is ≥40 dB (A) into the case group. The control group was selected according to the matching criteria of the same sex, same type of work, and the age difference was not more than 5 years old, and the working age difference was not more than 2 years. 276 subjects were selected into the case group and the control group respectively. The medium and high throughout single nucleotide polymorphism typing technology (SNPscanTM technology) was used to detect the polymorphism of three nucleotide sites of GSR gene, and conditional logistic regression was used to analyze the relationship between single nucleotide polymorphism (SNP) and NIHL, and the relationship between different polymorphic sites and the risk of NIHL after adjusting covariates. After stratification with different cumulative noise exposure (CNE) , Conditional logistic regression analysis was used to analysis the risk of NIHL at different loci. Results: The mean and standard deviation of age of the selected subjects was (40.28±8.00) , the mean and standard deviation of noise-exposed working years was (18.7±8.92) years. The range of noise exposure levels and comulative noise exposure were 80.05-93.35dB (A) and 86.83-107.92 dB (A) ·year, respectively. Compared with the control group, there were no statistically significant differences in age, noise-exposured working years, intensity of noise exposure, CNE, gender, drinking, hypertension prevalence and noise exposure level in the hearing loss group (P>0.05) , while there were statistically difference in smoking, binaural high-frequency average hearing threshold and binaural speech frequency (P<0.05) . After adjusting for smoking, drinking, hypertension and other factors, in the co-dominant model, compared with GGgenotype, the risk of NIHL was higher in rs1002149 GT genotype and rs2251780 GA genotype (OR=1.558, 95%CI: 1.028-2.361; OR=1.550, 95%CI: 1.020-2.355, P<0.05) ; compared with TT/GT genotype, the rs1002149 TT genotype has a higher risk of developing NIHL (OR=1.494, 95%CI: 1.002-2.228, P<0.05) , while rs3779647 genotype had no relationship with the risk of NIHL (P>0.05) . In the equivalent sound level (L(Aeq)) of noise >85 dB (A) stratification, compared with GG genotype, carrying rs1002149 GT genotype and rs2251780 GT genotype has higher risk of nihl (OR=1.801, 95%CI: 1.093-2.967; OR=1.720, 95%CI: 1.050-2.817, P<0.05) . Haplotype analysis of two sites, rs1002149 and rs2251780, was not found to be related to NIIHL susceptibility. Conclusion: The allele G of rs1695 and rs6591256 may be risk factors of NIHL.

[Prediction of KCNQ4gene polymorphism varies with CNE or noise exposure duration on the Risk of NIHL-Cox model analysis based on cohort study].

Objective: The purpose of this study was to explore the association between gene in the potassium recycling pathway 4 (KCNQ4) polymorphisms and the susceptibility to noise-induced hearing loss (NIHL) , and analysis the effect of cumulative noise exposure (CNE) and noise exposure duration on this association. Methods: A nested case-control study with 1∶1 matched was used based on the cohort of noise exposure in a steel factory. A total of 286 cases were selected as the group of hearing loss and 286 controls were chosen according to the matching standards of same gender, same type of work, age difference ≤ 5 years, noise exposure duration ≤ 2 years. The single nucleotide polymorphisms (SNPs) of rs4660468, rs4660470, rs34287852 in KCNQ4 were genotyped by SNPscan(TM) method. The codominant, dominant and recessive models were established to study KCNQ4 polymorphisms and the susceptibility to NIHL by single-factor conditional logistic regression analysis. The COX regression analysis was used to analyze the risk of developing NIHL in individuals with different genotypes along with the extending of noise exposure duration or CNE. Results: In the case of CNE≤96 dB (A) ·year, the risk of developing NIHL in individuals with TA genotype of rs4660470 was 2.197 times than individuals with TT genotypes (95%CI: 1.032~4.677) , and those with TA+AA and TT genotypes (HR=2.467, 95%CI: 1.025~5.934) With the increase of noise exposure duration, in rs4660470, individuals with TA genotype had a higher risk of suffering NIHL than those with TT genotype (HR=1.461, 95%CI: 1.061~2.011) , individuals with TA and/or AA genotype had a earlier risk of suffering NIHL than those with TT genotype. Conclusion: The mutant allele A of rs4660470 in KCNQ4 may be a risk factor for developing NIHL, CNE≤100 dB (A) ·year or the increase of noise exposure duration may further increase the risk of NIHL.

[Association between GSTP1 gave polymorphisms and susceptibility to noise-induced hearing loss].

Objective: To investigate the association between the single nucleotide polymorphisms (SNPS) at rs1695 and rs6591256 in glutathione S-transferase P1 (GSTP1) gene and susceptibility to noise-induced hearing loss in Chinese Han workers exposed to noise. Methods: A 1: 2 matched nested case-control study was performed, which based on the cohort of 6297 workers exposed to noise in an iron and steel plant in Henan, China, who were followed up from January 1, 2006 to December 31, 2015. According to the criteria of binaural average high-frequency hearing threshold ≥40 dB, a total of 292 workers were enrolled as hearing loss group; after the adjustment for sex, type of work, age (difference≤5 years) , and working years of noise exposure (difference≤2 years) , according to the criteria of binaural average high-frequency hearing threshold <35 dB, and the speech frequency hearing threshold of any ear at any frequency band ≤25 dB, a total of 584 workers were enrolled as control group. The single nucleotide polymorphisms (SNPs) of rs1695 and rs6591256 in GSTP1 were genotyped by high throughput SNP genotyping assay. Hardy-Weinberg equilibrium of control group was checked. The association between the SNPs at the two loci and susceptibility to NIHL was analyzed. Results: The L(Aeq, 8 h) range of workers exposed to noise was 80.2-98.8 dB (A) . The risk of NIHL in individuals with allele G of rs1695 was 1.291 times of those with allele A (95%CI: 1.042-1.598, P<0.05) . The risk of NIHL in individuals with allele G of rs6591256 was 1.390 times of those with allele A (95%CI: 1.119-1.728, P<0.05) . The risk of NIHL in individuals with AG and GG genotypes of rs6591256 was 1.437 times of those with AA genotype (95%CI: 1.057-1.952, P<0.05) . With the increase of noise exposure duration, individuals with AG and GG genotypes of rs6591256 had a higher risk of NIHL than those with AA genotype (HR=1.273, 95%CI: 1.002-1.616, P<0.05) . Conclusion: The allele G of rs1695 and rs6591256 may be risk factors of NIHL.

[Change of occupational stress from 1996 to 2012 among train engine drivers].

Objective: To analyze the change of level of occupational stress between 1996 and 2012 among train engine drivers. Methods: the cross-section investigation was conducted by using cluster sampling method, subjects included 1 116 and 1 002 passenger train engine drivers and freight train engine drivers respectively in 1996 and in 2012;occupational stressors, strains, personalities, buffering factors and individual factors were investigated by using Occupational Stress Instruments. Unconditional logistic regression analyses were performed to estimate the associations between job stressors, personalities, buffering factors and individual factors and strains. Multivariate OR(95%CI) were derived from the logistic regression models. Results: From 1996 to 2012, for the passenger train engine drivers the scores of role ambiguity (17.67±5.30 vs.14.11±4.66) increased 25.32%, mental load (10.41±3.56 vs. 16.29±2.08) and physical environment (3.61±2.18 vs. 7.03±1.65) scores decreased 36.10% and 48.64% respectively, sleep disorders (18.04±9.20 vs. 13.35±4.00) and negative affectivity (2.76±1.86 vs. 2.14±1.86) scores increased 33.14% and 28.97% respectively, the differences were statistical significant (P<0.001) . For the freight train engine drivers the scores of sleep disorders (20.33±8.17 vs. 12.47±4.12) and negative affectivity (2.95±1.70 vs. 1.87±1.81) scores increased 57.75% and 60.03% respectively, positive affectivity (2.17±1.60 vs. 2.91±1.50) score decreased 25.43%, the differences were statistical significant (P<0.001) . In general, scores varies in factors related to occupational stress among freight train engine drivers were larger than those among passenger train engine drivers. The risk factor of job dissatisfaction among passenger train drivers in 1996 was insufficient superior support (OR=3.77, 95%CI: 2.23-6.37) , the risk factors in 2012 were insufficient superior support (OR=3.35, 95%CI:1.56-7.17) , poor physical environment (OR=3.61, 95%CI: 1.91-6.80), and fewer positive affectivity (OR=3.47, 95%CI: 1.75-6.82). The risk factor of job dissatisfaction among freight train drivers in 1996 and in 2012 were insufficient superior support (OR (95%CI) were 3.11 (2.31-4.19), 2.59 (1.84-3.65) , respectively). Conclusion: The level of occupational stress among train engine drivers in 2012 was larger than that in 1996, the level of occupational stress among freight train drivers was larger than passenger train drivers, the interventions aimed at reducing occupational stress in the Chinese train engine drivers should take into account promotion for design of job organization and contents and organization management style.

[Self-esteem and Occupational Stress Relationship Analysis of 1413 Train Drivers in a Railway Bureau].

Objective: To investigate self-esteem status of train drivers. Methods: By using cluster sampling method, a cross-sectional study was conducted in 1 413 train drivers (including passenger train drivers 301, freight train drivers683, passenger shunting train drivers350, and high speed train drivers79) from a railway bureau. The occupational stressors, strains, self-esteem and personalities were measured using occupational stress instruments and effort-reward imbalance questionnaire. Results: The level of self-esteem is medium ofthe train drivers. Sself-esteem scores among different among different job category (job title) , marry status, age, length of service groups were statistical significance (P<0.01) . Differences of self-esteem among different educational level, exercise, smoking and drinking groups weren't statistical significance (P>0.05) . Correlation analysis revealed that self-esteem score was related positively to job satisfaction (r=0.300) , reward (r=0.842) , working stability (r=0.243) , promotion opportunities (r=0.493) , positive affectivity (r=0.216) , responsibility for human beings (r=0.112) and responsibility for things scores (r=0.108) (P<0.01) , negatively to sleep quality (r=-0.103) , social support (r=-0.212) , role conflict (r=-0.007) , role ambiguity (r=-0.169) , physiological needs (r=-0.115) , daily stress (r=-0.150) , negative affectivity (r=-0.252) , depressive symptoms scores (r=-0.215) (P<0.01) . Nonparametric test found that train drivers of group with low self-esteem score reported higher scores for physiological need, role conflict, role ambiguity, social sleep quality, depressive symptoms, negative affectivity, social support and daily stress scores than the medium and higher groups (P<0.01 or<0.05) . But reword, job satisfaction, positive affectivity, copping stratgy, working stability and promotion opportunities scores were lower than the group of medium and higher groups (P<0.01) . Inter-group conflict scores were insignificance (P>0.05) . Multivariate logistic regression analysis revealed that low low self-esteem for drivers occured the risk of job dissatisfaction about 1.5 times as high as that of drivers with higher self-esteem (OR=1.476) Conclusion: Different types of locomotive drivers get different level of self-esteem. Self-esteem was affected by occupational stress largely.

[Relationship between depressive symptoms and occupational stress in locomotive drivers].

Objective: To explore relationship between depressive symptoms and occupational stress in locomotive drivers. Methods: By using cluster sampling method, a cross-sectional study was conducted in 1413 train drivers (including passenger train drivers301, freight train drivers 683, passenger shunting train drivers350, and high speed train drivers79) from a railway bureau. The individual factors, depression, occupational stress, strains, personalities, coping strategy and social support were measured using occupational stress instruments, job content questionnaire and effort-reward imbalance questionnaire. Results: CThe differences of depression scores between take exercise and don't exercise groups were statistical significance (P<0.01) . The differences of depression scores among different age, length of service, job category, educational status,marital status, smoking and drinking groups were`t statistical significance (P>0.05) .Correlation analysis revealed that depression score was related negatively to reward, job satisfaction, self-esteem, promotion opportunities, working stability and positively emotions score (P<0.01) , related positively to sleep disorders, effort, physiological needs, psychological need, daily stress, negative emotions, social support, esponsibility for person, responsibility for thing, conflict in the group, role conflict, role ambiguity score (P<0.01) . Nonparametric test analysis found that train drivers with high depression score reported higher psychological need, effort, promotion opportunities, role ambiguity, role conflict, conflict between groups, responsibility for person, responsibility for thing, physiological needs, daily stress, negative emotions, social support and copping strategies than those with moderate and lower depression score (P<0.01) , but the scores of job satisfaction, reword, self-esteem, working stability, positive emotions were lower than other groups those with moderate and lower depression score (P<0.01) . Multivariate logistic regression analysis revealed the risk of depression for drivers with more sleep disorder, low social support more than three times as high as that for drivers with few sleep disorder, hing social support (OR=3.615,3.266) .High negative emotions, more psychological need, high daily stress were more than twice times as high as that for drivers with low negative emotions, few psychological need, low daily stress (OR:2.444、2.489、2.065) . Conclusion: sleep disorder, low social support and job stress had larger effect on depression. To improve sleep, social support, self-esteem and decrease job stress and negative emotions are main measures of decrease depression for train drivers.

[Social support and occupational stress relationship analysis of 1 413 train drivers in a railway bureau].

Objective: To investigate the social support status of train drivers. Methods: Using cluster sampling, a cross-sectional study was conducted in 1 413 male train drivers (including 301 passenger train drivers, 683 freight train drivers, 85 guest scheduling train drivers, 265 cargo adjustable drivers, and 79 high-speed train drivers) from a railway bureau depot. The survey included individual factors, social support, occupational stressors, strains, personalities, and coping strategy using occupational stress instruments and effort-reward imbalance questionnaire. We compared the difference in social support scores between different drivers, who were divided according to job type and age. Additionally, the correlation between social support score and job strain-related factors was analyzed. The influence of depressive symptoms and job satisfaction were analyzed using a non-conditional logistic multivariate model. Results: The overall average age P(50) (P(25),P(75)) of 1 413 train drivers was 33.92 (27.83,43.58) years. The overall average length of service 12.25 (5.25,22.75) years. A significant difference in social support scores was observed according to job type (H=23.23, P<0.001). The specific scores were passenger driver(27 (23,32)), freight train driver (26 (22,30)), guest scheduling driver (27 (24,30)), cargo adjustable driver (26 (22,31)), and high-speed train driver (30 (26,36)) (P(50)(P(25),P(75))). Additionally, social support scores among different age groups were significantly different (H=6.64, P=0.036). The specific scores were ≤30 years (26 (22,31)), 30-40 years (27 (23,33)), and >40 years (27 (22,31)). Correlation analysis revealed that the social support score was negatively associated with job satisfaction (r=-0.43), reward (r=-0.22), working stability (r=-0.23), promotion opportunities (r=-0.12), positive affectivity (r=-0.31), esteem (r=-0.21), and self-esteem (r=-0.20) scores (P<0.001). The social support score was positively associated with sleep disorders (r=0.33), external effort (r=0.21), pay within (r=0.12), role conflict (r=0.20), conflict between groups (r=0.17), conflict in groups (r=0.06), responsibility for the others (r=0.06), responsibility for things (r=0.08), physiological needs (r=0.39), psychological needs (r=0.19), daily stress (r=0.29), negative affectivity (r=0.23), and depressive symptoms (r=0.44) scores (P<0.05). Multivariate logistic regression analysis revealed social support had a great influence on depressive symptoms and low job satisfaction. Compared with high social support, low social support resulted in depressive symptoms (OR=4.12, 95% CI:3.19-5.33) and low job satisfaction (OR=2.18, 95%CI:1.65-2.88). Conclusion: Train drivers obtained various levels of social support. Social support greatly affected occupational stress. High social support was related to reduction in the occurrence of occupational stress, depressive symptoms, and low job satisfaction. Social support is related to mental health of train drivers.

[A cohort study on occupational noise induced hearing loss in workers at an iron and steel plant].

Objective: To analyze the incidence rate of occupational noise-induced hearing loss in noise-exposed workers in an iron and steel plant from 2006 to 2015. Methods: Using a cohort study method, workers exposed to occupational noise from Jan 1, 2006 to Dec 12, 2015 were followed up and the pure tone hearing test was conducted. In total, 6 297 subjects completed two or more physical checks and the pure tone hearing test and were included in the analysis. The noise exposure level at the workplace and the equivalent continuous A-weighted sound pressure level for workers was monitored and the cumulative noise exposure dose was evaluated. The subjects were divided into low, middle and high exposure groups according to the noise exposure level, and the equivalent continuous A-weighted sound pressure level for 8 hours for each group was 80.6-85.0, 85.1-90.0 and 90.1-103.4 dB (A), respectively. While the RR and 95% CI were derived from unconditional logistic regression models. In logistic regression analysis, confounding factors such as age, gender, smoking habit, drinking habit, high temperature exposure and chemical hazards exposure level were controlled. Results: During the follow-up period, 392 cases of occupational noise-induced hearing loss were diagnosed among the 6 297 subjects, with an incidence rate of 6.23%; 318 cases of high-frequency hearing loss were diagnosed, with an incidence rate of 5.05%; and 74 cases of occupational noise-induced deafness were diagnosed, with an incidence rate of 1.18% . The incidence rates of hearing loss among the high, medium and low exposure groups were 9.22% (158/1 737), 6.49% (204/3 142) and 2.08% (30/1 442), respectively; the rates of high-frequency hearing loss were 7.41% (127/1 737), 5.25% (165/3 142) and 1.80% (26/1 442), respectively; and the rates of occupational noise-induced deafness were 1.81% (31/1 737), 1.24% (39/3 142) and 0.28% (4/1 442), respectively. For the groups corresponding to cumulative noise exposure doses of ≤84.99, 85.00- 87.99, 88.00- 90.99, 91.00- 93.99, 94.00- 96.99, 97.00- 100.99, 101.00- 102.99 and ≥103.00 dB (A) · year, the incidence rates of hearing loss were 0 (0/185), 1.22% (2/164), 2.52% (17/674), 3.83% (35/913), 5.80% (106/1 827), 6.02% (67/1 113), 9.20% (95/1 003) and 18.04% (70/388), respectively. Compared with the low exposure group, the RR of hearing loss, high-frequency hearing loss and occupational noise-induced deafness for the high exposure group were 4.78 (95% CI: 3.22- 7.11), 4.36 (95% CI: 2.84- 6.69) and 6.63 (95% CI: 2.33- 18.82), respectively; and for the medium exposure group were 3.27 (95% CI: 2.22-4.82), 3.02 (95% CI: 1.99-4.59) and 4.52 (95% CI: 1.61-12.67), respectively. Conclusion: The incidence rate of hearing loss for workers exposed to noise in an iron and steel plant was related to the cumulative noise exposure dose, gender, age, educational level, smoking habits, drinking habits and exposure to high temperature.