Theoretical study on different substituent-modified derivatives of 6-dinitrophenyl-5,6,7,8-tetrahydro-4-imidazo [4,5-e]furazano[3,4-b] pyrazine.

CONTEXT: The compounds of the "565" parent ring structure have received much attention from researchers because of their excellent detonation performance. In the present study, 81 derivatives were designed by introducing different substituents based on 6-dinitrophenyl-5,6,7,8-tetrahydro-4-imidazo[4,5-e]furazano[3,4-b] pyrazine (DIOP), which is a compound of the parent ring structure of 565, and the performance of these derivatives, such as the electronic structure, energy gap, heat of formation, and detonation performance, were investigated. Among these energy-containing derivatives, the density ranges from 1.70 to 2.17 g/cm3, the detonation velocity ranges from 8.01 to 10.26 km/s, and the detonation pressure ranges from 27.99 to 49.88 GPa. Through comprehensive analysis of several properties of DIOP derivatives, it was found that the oxygen balance of derivatives with the -ONO2 group was greater than zero and close to zero, while the oxygen balance of derivatives with other groups was almost all less than zero. Among them, G8 (D = 10.1 km/s, P = 47.72 GPa), H8 (D = 10.11 km/s, P = 47.92 GPa), and I8 (D = 10.26 km/s, P = 49.88 GPa) had higher detonation velocity and pressure among all derivatives, and their impact sensitivity was better than RDX. Therefore, three potential high-energy and less sensitive energy-containing derivatives, G8, H8, and I8, were screened out. The intramolecular interactions of the three derivatives were further analyzed, and it was found that there were intensive van der Waals interactions and significant spatial steric effects within the molecules, which had a positive effect on reducing the shock sensitivity of the compounds. Moreover, the three derivatives have a large degree of stacking, which leads to a high density. METHODS: All calculations in this paper are performed using Gaussian16 based on density functional theory. Firstly, the structures of the derivatives were optimized at the level of B3LYP-D3/6-311G**, and then single-site energy calculations were carried out at the level of M06-2X-D3/def2-TZVPP, to reveal the effects of single substituents versus multiple substituents and isomerism on the properties of the DIOP-based energetic derivatives. Multiwfn was used to plot the density of states (DOS) of the derivatives and to calculate the molecular surface electrostatic potential at 0.001 e/Bohr3 electron density, 0.25 Bohr lattice spacing surface.

Development and validation of a nomogram for predicting sever cancer-related fatigue in patients with cervical cancer.

OBJECTIVE: Cancer-related fatigue (CRF) has been considered the biggest influencing factor for cancer patients after surgery. This study aimed to develop and validate a nomogram for severe cancer-related fatigue (CRF) patients with cervical cancer (CC). METHODS: A cross-sectional study was conducted to develop and validate a nomogram (building set = 196; validation set = 88) in the Department of Obstetrics and Gynecology of a Class III hospital in Shenyang, Liaoning Province. We adopted the questionnaire method, including the Cancer Fatigue Scale (CFS), Medical Uncertainty in Illness Scale (MUIS), Medical Coping Modes Questionnaire (MCMQ), Multidimensional Scale of Perceived Social Support (MSPSS), and Sense of Coherence-13 (SOC-13). Binary logistic regression was used to test the risk factors of CRF. The R4.1.2 software was used to develop and validate the nomogram, including Bootstrap resampling method, the ability of Area Under Curve (AUC), Concordance Index (C-Index), Hosmer Lemeshow goodness of fit test, Receiver Operating Characteristic (ROC) curve, Calibration calibration curve, and Decision Curve Analysis curve (DCA). RESULTS: The regression equation was Logit(P) = 1.276-0.947 Monthly income + 0.989 Long-term passive smoking - 0.952 Physical exercise + 1.512 Diagnosis type + 1.040 Coping style - 0.726 Perceived Social Support - 2.350 Sense of Coherence. The C-Index of the nomogram was 0.921 (95% CI: 0.877∼0.958). The ROC curve showed the sensitivity of the nomogram was 0.821, the specificity was 0.900, and the accuracy was 0.857. AUC was 0.916 (95% CI: 0.876∼0.957). The calibration showed that the predicted probability of the nomogram fitted well with the actual probability. The DCA curve showed when the prediction probability was greater than about 10%, the benefit of the nomogram was positive. The results in the validation group were similar. CONCLUSION: This nomogram had good identifiability, accuracy and clinical practicality, and could be used as a prediction and evaluation tool for severe cases of clinical patients with CC.

Periodic DFT study of structural transformations of cocrystal CL-20/MMI under high pressure.

CONTEXT: The crystal and molecular structure, electronic properties, optical parameters, and elastic properties of a 1:2 hexanitrohexaazaisowurtzitane (CL-20)/2-mercapto-1-methylimidazole (MMI) cocrystal under 0 ~ 100 GPa hydrostatic pressure were calculated. The results show that the cocrystal CL-20/MMI undergoes three structural transitions at 72 GPa, 95 GPa, and 97 GPa, respectively, and the structural transition occurs in the part of the MMI compound. Structural mutations formed new bonds S1-S2, C2-C7, and N1C5 at 72GPa, 95 GPa, and 97 GPa, respectively. Similarly, the formation of new bonds is confirmed on the basis of an analysis of the changes in lattice constants, cell volumes, and partial densities of states (PDOS) for S1, S2, C2, C7, N1, and C3 at the corresponding pressures. The optical parameters show that the pressure makes the peaks of various optical parameters of CL-20/MMI larger, and the optical activity is enhanced. The optical parameters also confirm the structural mutation of CL-20/MMI under the corresponding pressure. METHOD: CL-20/MMI was calculated by using the first-principles norm-conservative pseudopotential based on density functional theory (DFT) in the CASTEP software package. For the optimization results, the Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is selected to optimize the geometry of the cocrystal in the range of 0-100 GPa. GGA/PBE (Perdew-Burke-Ernzerhof) was selected to relax the cocrystal CL-20/MMI fully without constraints at atmospheric pressure. The sampling scheme in the Brillouin zone [10] is the Monkhorst-Pack scheme, and the number of k-point grids was 2 × 2 × 2. By contrast, this study will use the LDA method to calculate.

The regulation of high-energy insensitive compound 2,6-diamino-3,5-dinitropyrazine-1-oxide by external electric field.

CONTEXT: The influence of external electric fields (EEFs) on chemical substances has always been a hot topic in the field of theoretical chemistry research. 2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is an energetic material with excellent comprehensive properties and enormous potential for application. This article explores the molecular structure, electronic structure, energy change, frontier molecular orbitals (FMOs) and density of states (DOS), UV-Vis spectra, and infrared spectra of LLM-105 under various electric field conditions. The results indicate that negative EEF can improve the stability of LLM-105, reflected in the initiation of changes in bond length and HOMO-LOMO gap. EEF has a significant impact on the electronic structure of LLM-105. The polarization of the electronic structure brings about a change in total energy, which is reflected in the analysis of energy changes. In addition, the external electric field will cause the frequency of the infrared spectra and the UV-Vis spectra to have different degrees of blue shift. The results of the analysis are helpful to understand the changes of energetic materials under the applied electric field. METHODS: Based on the density functional theory (DFT), the structural optimization and energy calculation were carried out by using B3LYP/6-311G(d, p) and B3LYP/def2-TZVPP methods, respectively. After optimization convergence, vibration analysis was performed without imaginary frequencies to obtain stable configurations. Then, the molecular structure, electronic structure, energy changes, molecular orbital and density of states, UV-Vis spectra, and infrared spectra were analyzed.

The moderating effect of self-efficacy between social constraints, social isolation, family environment, and depressive symptoms among breast cancer patients in China: a cross-sectional study.

BACKGROUND: For female breast cancer patients, the psychological status after surgery, especially the social and family psychological-related factors, deserves more attention. This study analyzed the influence of social constraints, social support, social isolation, family conflict, and family emotion expression on depression. At the same time, this study conducted the relationship between the variables and the mechanism of action. METHODS: We conducted a cross-sectional study and 522 breast cancer patients finished questionnaires consisting of Self-Rating Depression Scale (SDS), General Self-Efficacy Scale (GSES), Multi-Dimensional Scale of Perceived Social Support (MSPSS), Social Constraints Scale-5 (SCS-5), Family Environment Scale (FES), and Lubben Social Network Scale (LSNS-6). Multivariable logical regression was used to explore influencing factors. Pearson's correlation, hierarchical regression, and simple slope analysis were conducted to verify the role of self-efficacy. RESULTS: 71.6% of patients had depressive symptoms. Family contradiction (OR = 10.086), social constraints (OR = 2.522), social isolation (OR = 2.507), and high blood glucose (OR = 2.156) were risk factors of depressive symptoms. Family emotional expression (OR = 0.480), family intimacy (OR = 0.235), and self-efficacy (OR = 0.246) were protective factors against depressive symptoms. The interactive items interpretation quantity were as follows: Contradiction*Self-efficacy (ΔR2 = 2.3%, P < 0.001), Emotional expression*Self-efficacy (ΔR2 = 2.6%, P < 0.001), Intimacy*Self-efficacy (ΔR2 = 1.0%, P = 0.018), Social constraints*Self-efficacy (ΔR2 = 1.0%, P = 0.008), Social networks*Self-efficacy (ΔR2 = 1.0%, P = 0.010), Blood Glucose*Self-efficacy (ΔR2 = 0.6%, P = 0.023). The influence of independent variables on depressive symptoms was gradually decreased in the low, mean, and high groups of self-efficacy. CONCLUSION: Postoperative Chinese breast cancer survivors reported higher depressive symptoms. Social, family, and physiological factors could affect depressive symptoms, in which self-factor played moderator roles.

Sense of coherence mediates perceived social support and depressive and anxiety symptoms in cervical cancer patients: a cross-sectional study.

BACKGROUND: Depression and anxiety symptoms are two common psychological disturbances in cervical cancer patients. We tested whether sense of coherence (SOC) mediates the association of perceived social support (PSS) with depression and anxiety symptoms among cervical cancer patients in China. METHODS: We conducted a survey involving 294 cervical cancer patients aged ≥ 18 years from July to December 2020 at three hospitals in Liaoning Province, China; 269 patients completed the survey. We included a demographic questionnaire, the Multidimensional Scale of Perceived Social Support (MSPSS), Antonovsky's Sense of Coherence Scale, the Hamilton Depression Rating Scale, and the Zung Self-Rating Anxiety Scale (SAS) in this study. We used hierarchical regression analysis to examine the relationship among PSS, SOC, and symptoms of depression and anxiety. We used asymptotic and resampling strategies to explore the mediating effect of SOC. RESULTS: PSS was negatively associated with depressive symptoms (r = - 0.439, P < 0.01) and anxiety symptoms (r = - 0.325, P < 0.01). SOC was negatively related to depressive symptoms (r = - 0.627, P < 0.01) and anxiety symptoms (r = - 0.411, P < 0.01). SOC partially mediated the association between PSS and depressive symptoms (a*b = - 0.23, BCa95% CI: [- 0.31, - 0.14]) and anxiety symptoms (a*b = - 0.15, BCa95% CI: [- 0.23, - 0.08]). The proportions of the mediating effect accounting for SOC were 49.78% and 41.73% for depressive symptoms and anxiety symptoms, respectively. CONCLUSION: The study showed that SOC could mediate the association between PSS and symptoms of depression and anxiety. This suggests that SOC might serve as a potential target for intervention in symptoms of depression and anxiety that accompany cervical cancer.

Interaction of anxiety and hypertension on quality of life among patients with gynecological cancer: a cross-sectional study.

BACKGROUND: Patients with gynecological cancer are prone to anxiety, and many of them are accompanied by hypertension, which seriously affects the quality of life (QOL). The study was to explore the interaction of anxiety and hypertension on QOL, and the moderating effect of perceived social support (PSS) in the impact of anxiety and hypertension on QOL of patients with gynecological cancer. METHODS: A cross-sectional study was conducted in 2020, and 566 patients have been collected from the Affiliated Hospital of China Medical University. The Self-Rating Anxiety Scale (SAS), the Functional Assessment of Cancer Therapy Genera tool (FACT-G), and the Multidimensional Scale of Perceived Social Support Scale (MSPSS) were used. The interaction was analyzed by additive model, and the moderating effect was conducted by regression analysis and the simple slope analysis. RESULTS: We found that 68.8% of patients had poor QOL due to the interaction between anxiety and hypertension. The relative excess risk ratio (RERI) was 22.238 (95%CI:44.119-88.596); the attribution ratio (AP) was 0.688 (95%CI:0.234-1.142); The interaction index (S) was 3.466 (95%CI: 0.823-14.435). The interaction items of PSS and anxiety were negatively correlated with QOL (ß = -0.219, P < 0.01) and explained an additional 4.0% variance (F = 68.649, Adjusted R2 = 0.399, ΔR2 = 0.040, P < 0.01); PSS and blood pressure interaction item was not associated with QOL (ß = 0.013, F = 55.138, Adjusted R2 = 0.365, ΔR2 = 0.001, P = 0.730). CONCLUSIONS: When anxiety and hypertension coexist, the QOL was affected. PSS played a moderating role in the impact of anxiety on QOL. Healthcare providers should take intervention measures to improve patients' social support to reduce the impact of anxiety on QOL.

The Interaction between Occupational Stress and Smoking, Alcohol Drinking and BMI on Hypertension in Chinese Petrochemical Workers.

BACKGROUND: Hypertension is one of the most vital risk factors for cardiovascular diseases, so we wanted to explore the impact of the interaction between occupational stress and smoking, alcohol drinking and BMI on hypertension in Chinese petrochemical workers. METHODS: A total of 1488 employees participated. Questionnaires included the value of blood pressure, occupational stress (assessed by the effort-reward imbalance scale), demographic factors and work conditions. Multivariable logistic regression was used to explore related factors, and the interactions between occupational stress and smoking, alcohol drinking and BMI on hypertension were analyzed using an additive model. RESULTS: The prevalence of hypertension was 34.3%. Age ≥ 56 (OR = 3.19, 95%CI: 1.841-5.526), male (OR = 1.436, 95%CI: 1.056-1.954), BMI ≥ 25 (OR = 1.86, 95%CI: 1.468-2.346), smoking (OR = 1.52, 95%CI: 1.191-1.951) and alcohol drinking (OR = 1.53, 95%CI: 1.180-1.972), ERI > 1 (OR = 1.50, 95%CI: 1.133-1.960) are risk factors for hypertension, and a higher education level (OR = 0.57, 95%CI: 0.438-0.754) is a protective factor against hypertension. Positive interactions existed between occupational stress and smoking (RERI = 2.134, AP = 0.328, S = 1.635), alcohol drinking (RERI = 2.332, AP = 0.361, S = 1.746) and BMI (RERI = 1.841, AP = 0.340, S = 1.717) on hypertension in petrochemical workers. CONCLUSIONS: Age, gender, educational level, BMI, smoking, alcohol drinking and occupational stress are closely related to the risk of hypertension. There are also positive interactions between occupational stress and alcohol drinking, smoking and BMI, which have a certain impact on hypertension.

Baicalein Inhibits the SMYD2/RPS7 Signaling Pathway to Inhibit the Occurrence and Metastasis of Lung Cancer.

Objective: This study investigated the potential effects of Baicalein on proliferation, migration, and invasion of human lung cancer A549 and NCI-H1299 cells and its possible mechanisms. Methods: The effects of Baicalein on proliferation and invasion of A549 and NCI-H1299 cells were detected by MTT assay, clonogenesis assay, and Transwell assay. A subcutaneous transplanted tumor model was used to evaluate the effects of SMYD2 and Baicalein on the proliferation of lung cancer. Baicalein inhibited in SMYD2/RPS7 signaling pathway in tumor cells was also detected by qRT-PCR. Results: Baicalein significantly inhibited the growth of lung cancer cells. In addition, Baicalein significantly reduced the rate of A549 and NCI-H1299 cell invasion and clone formation in a dose-dependent manner. Animal experiments showed that both SMYD2 and Baicalein treatments could inhibit lung cancer tumor proliferation. Mechanism studies suggest that Baicalein inhibits the SMYD2/RPS7 signaling pathway. Conclusion: These results indicated that Baicalein could inhibit the proliferation, migration, and invasion of LUNG cancer A549 and NCI-H1299 cells. Baicalein inhibits cell proliferation by downregulating the SMYD2/RPS7 signaling pathway.

The prevalence, relative risk factors and MTHFR C677T genotype of H type hypertension of the elderly hypertensives in Shanghai, China: a cross-section study : Prevalence of H type hypertension.

BACKGROUND: H type hypertension is defined as homocysteine (Hcy) ≥ 10 µmol/L in combination with primary hypertension. Studies demonstrated that the existence of hyperhomocysteine (HHcy) in hypertensive exacerbates the poor outcome of cardiocerebral incidents. This study was to investigate the current epidemic situation of H type hypertension and determine the risk factors in order to find intervention targets for H type hypertensives. METHODS: We conducted a cross-sectional study using cluster sampling design in Shanghai, China from July 2019 and April 2020. 23,652 patients with primary hypertension were enrolled in this study. Their medical information was recorded, and the level of Hcy concentrations and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphisms were detected. RESULTS: In total, 22,731 of 23,652 patients were recorded. The mean age was 68.9 ± 8.6 y and 43% were men. 80.0% of the enrolled patients had H type hypertension. The frequency of allele T was 40.9%, and the proportions of the CC, CT, and TT genotypes were 36.1%, 46.0%, and 17.9%, respectively. Compared with the TT genotype, the plasma Hcy concentration levels were lower in patients with the CC/CT genotype (18.96 ± 13.48 µmol/L vs. 13.62 ± 5.20/14.28 ± 5.36, F = 75.04, p < 0.01). The risk for H type hypertension was higher in elderly people. Men had ~ 5.55-fold odds of H type hypertension compared with women. Patients with CT genotype and TT genotype had ~ 1.36- and ~ 2.76-fold odds of H type hypertension compared with those with CC genotype, respectively. Smoking and diabetes were not significantly associated with H type hypertension. CONCLUSIONS: The prevalence of H type hypertension in patients with primary hypertension was 80.0%, which was higher than the 75% found in prior report in China. Age, gender, and MTHFR C677T polymorphisms rather than smoking and diabetes were independently associated with H type hypertension.

Is the Water System Healthy in Urban Agglomerations? A Perspective from the Water Metabolism Network.

Urban agglomerations are a primary spatial focus of socioeconomic activity and inherently include large volumes of embodied water. We have applied the concept of water metabolism health to comprehensively evaluate the overall operation of water systems in urban agglomerations and propose an innovative assessment framework. In particular, we constructed a water metabolism network (WMN) model to simulate a water system in which different cities and sectors are integrated, combining a newly compiled multiregional input-output (MRIO) table of water flow with ecological network analysis (ENA). A case study considering the Pearl River Delta (PRD) urban agglomeration in 2015 demonstrates that its network is well synergic but highly dependent, with considerable negative effects. Highly developed cities in southeastern of the PRD exhibit higher embodied water productivity and robustness but impose considerable negative effects on the water system. We found the agricultural sector to be a dominant controller of the network; the construction and service sectors represent the primary beneficiaries with strong competition. We suggest measures at various scales to improve water utilization efficiency and promote positive interactions between components, thus improving water metabolism system health for urban agglomerations.

Psychological Capital Mediates the Association Between Perceived Organizational Support and Work Engagement Among Chinese Doctors.

Background: As experts studying occupational health psychology know, low level of work engagement leads to higher turnover intentions. Some researchers have put a focus on the association between organizational support and work engagement. However, little has been done concerning the mediating effect of psychological capital (PsyCap) on the association between perceived organizational support (POS) and work engagement (vigor, dedication, absorption) among Chinese doctors. Methods: A cross-sectional study has been carried out from November to December in 2017, in Liaoning Province, China. The questionnaire consists of Survey of Perceived Organizational Support, the Utrecht Work Engagement Scale, Psychological Capital Questionnaire, and demographic and working variables. The self-administered questionnaires were distributed to 1,009 doctors. Effective responses were collected from 836 participants (82.85%). Hierarchical multiple regression and the asymptotic and resampling strategies were used to examine the association between POS and work engagement mediated by PsyCap. Results: After controlling the demographic and working variables, POS was positively related to vigor (ß = 0.402, P < 0.01), dedication (ß = 0.413, P < 0.01), and absorption (ß = 0.373, P < 0.01). Psychological capital was positively associated with vigor (ß = 0.442, P < 0.001), dedication (ß = 0.413, P < 0.001), and absorption (ß = 0.395, P < 0.001). Thus, PsyCap [a × b = 0.1895, bias-corrected and accelerated 95% confidence interval (BCa 95% CI) = 0.1524, 0.2290]; a × b = 0.1517, BCa 95% CI = 0.1180, 0.1875; a × b = 0.1693, BCa 95% CI = 0.1299, 0.2099] significantly mediated the association between POS and vigor, dedication, and absorption, respectively. Conclusion: There was a low level of work engagement among Chinese doctors. Perceived organizational support could indirectly improve vigor, dedication, and absorption, partially through mediator PsyCap. Perceived organizational support intervention, education, and training in PsyCap should be carried out to cope with work engagement.

A Study on the Psychological Factors Affecting the Quality of Life Among Ovarian Cancer Patients in China.

PURPOSE: We aim to test whether resilience mediates the association of fear of progression (FoP) with quality of life (QoL) among ovarian cancer patients in China. METHODS: We collected 230 questionnaires from the First Affiliated Hospital of China Medical University in Liaoning Province, and 209 completed the questionnaire survey. The survey instrument consisted of four questionnaires: a sociodemographic and clinical characteristics questionnaire, the Functional Assessment of Cancer Therapy general instrument, the Fear of Progression Questionnaire-Short Form and the Connor-Davidson Resilience Scale. Hierarchical regression analysis was used to examine the relationship among FoP, resilience, and QoL, including physical well-being, social well-being, emotional well-being, and functional well-being. We used asymptotic and resampling strategies to examine the indirect effect of resilience. RESULTS: FoP was negatively associated with resilience (r=-0.543, P<0.01) and QoL (physical well-being: r=-0.537, P<0.01; social well-being: r=-0.426, P<0.01; emotional well-being: r=-0.487, P<0.01; functional well-being: r=-0.529, P<0.01). Resilience was positively related with QoL (physical well-being: r=0.449, P<0.01; social well-being: r=0.548, P<0.01; emotional well-being: r=0.430, P<0.01; functional well-being: r=0.655, P<0.01). Resilience partly mediated the association between FoP and physical well-being (a×b=-0.05, BCa 95% CI: -0.09, -0.02), social well-being (a×b=-0.21, BCa 95% CI: -0.29, -0.14), emotional well-being (a×b=-0.05, BCa 95% CI: -0.08, -0.02), and functional well-being (a×b=-0.24, BCa 95% CI: -0.32, -0.17). The proportion of the mediating effect accounted for by resilience were 22.57%, 57.22%, 26.02%, 53.42% for physical well-being, social well-being, emotional well-being and functional well-being, respectively. CONCLUSION: The study showed that resilience could mediate the association between fear of progression and quality of life. It suggests that resilience might provide a potential target for intervention in quality of life with ovarian cancer.

Perceived Organizational Support Associated with Depressive Symptoms Among Petroleum Workers in China: A Cross-Sectional Study.

OBJECTIVE: The objective of this study was to explore the association between perceived organizational support (POS) and depressive symptoms, and to further explore whether self-efficacy can act as a moderator between POS and depressive symptoms among Chinese petroleum workers. METHODS: There was a cross-sectional study conducted at a petrochemical enterprise in Liaoning Province, China, from July to August 2018. A series of questionnaires were accomplished by 1836 petroleum workers, including the Center for Epidemiologic Studies Depression Scale (CES-D), the Survey of Perceived Organizational Support (SPOS), and the General Self-Efficacy Scale (GSES). Hierarchical regression analysis was used to examine the relationship of SPOS score, GSES score, and SPOS score×GSES score interaction with CES-D score. A simple slope analysis will be carried out if the interaction has statistical significance. RESULTS: Hierarchical regression analysis showed that SPOS score (ß=-0.538, P<0.01) and GSES score (ß=-0.313, P<0.01) played a main influence on CES-D score. The SPOS score×GSES score interaction term significantly explained an extra 9.7% of the variance (F=253.932, adjusted R 2=0.582, ΔR 2=0.097, P<0.01). The interaction term was positively correlated with CES-D score (ß=0.334, P<0.01). The relationship between SPOS score and CES-D score gradually decreased in the low (1 SD below the mean, ß=-0.589, P<0.01), mean (ß=-0.338, P<0.01), and high (1 SD above the mean, ß=-0.087, P<0.01) groups of GSES score. CONCLUSION: This study showed that POS and self-efficacy played a main influence on depressive symptoms, and the interaction term was positively correlated with depressive symptoms. Self-efficacy could attenuate the association between POS and depressive symptoms. It suggests that appropriate POS and self-efficacy enhancement measures ought to be supplied to relieve depressive symptoms.

The association between resilience, perceived organizational support and fatigue among Chinese doctors: A cross-sectional study.

BACKGROUND: Fatigue influences doctors' physical and mental health seriously, additionally, the topic has received wide attention recently. This study aimed to identify the association among resilience, perceived organizational support (POS) and fatigue, and to further explore whether POS could be a moderator in the association between resilience and fatigue in Chinese doctors. METHODS: A cross-sectional study was conducted in Liaoning Province in China in 2018. Out of 1000 randomly selected doctors, 866 completed the Chalder Fatigue Scale, the Connor-Davidson Resilience Scale, Survey of Perceived Organizational Support, and the questions about demographic characteristics and job condition variables. The association among resilience, POS and resilience × POS interaction with physical and mental fatigue were examined by hierarchical multiple regression. Simple slope analysis was conducted to visualize the interaction. RESULTS: The association between resilience and physical fatigue was gradually increased in the low (1 standard deviation [SD] below the mean, ß = -0.127, P< 0.05), mean (ß = -0.292, P < 0.05) and high (1 SD above the mean, ß = -0.457, P < 0.05) groups of POS. Additionally, the association was also different in the low (1 SD below the mean, ß = -0.240, P < 0.01), mean (ß = -0.357, P < 0.01) and high (1 SD above the mean, ß = -0.474, P < 0.01) groups of POS. LIMITATIONS: Due to the cross-sectional design, the study cannot draw any conclusion of causal relationships among study variables. CONCLUSIONS: POS could moderate the association among resilience, physical and mental fatigue. More interventions related to resilience and POS will be helpful to alleviate fatigue among Chinese doctors.

The mediating role of psychological capital on the association between workplace violence and professional identity among Chinese doctors: a cross-sectional study.

Background: Workplace violence (WPV) and psychological capital (PsyCap) are linked to professional identity, however, little research has examined how WPV is associated with professional identity via PsyCap. This study is aimed to examine the association between WPV and professional identity, and to further explore whether PsyCap can serve as a mediator between WPV and professional identity among Chinese doctors. Materials and methods: A cross-sectional study was conducted from November to December in Liaoning Province in China, in 2017. The study used a questionnaire consisting of Workplace Violence Scale (WVS), Occupational Identity Scale (OIS), Psychological Capital Questionnaire (PCQ), as well as questions about demographic characteristics. Out of 1200 doctors, 995 (effective response rate of 82.92%) completed the questionnaire survey and became our final subjects. Hierarchical multiple regression and the asymptotic and resampling strategies were conducted to explore the mediating role of PsyCap in the relationship between WPV and professional identity. Results: After adjusting for demographic characteristics, WPV was negatively associated with professional identity (ß=-0.37; P<0.01). Mediation analysis indicated that PsyCap was a mediator in the relationship between WPV and professional identity. Two dimensions of PsyCap: self-efficacy (a*b =-0.04, BCa 95% CI: (-0.08, -0.01); P<0.01) and hope (a*b =-0.04, BCa 95% CI: (-0.08, -0.01); P<0.01) also did exhibit mediating effects in the relationship between WPV and professional identity. The proportion of self-efficacy, hope and PsyCap mediation was 10.73%, 10.77%, 36.22% for professional identity respectively. Conclusion: These results provided evidence that PsyCap could mediate the association between WPV and professional identity. To increase the level of professional identity, positive interventions targeting PsyCap should be taken, with a focus on self-efficacy and hope.

Assessment of the Casualty Risk of Multiple Meteorological Hazards in China.

A study of the frequency, intensity, and risk of extreme climatic events or natural hazards is important for assessing the impacts of climate change. Many models have been developed to assess the risk of multiple hazards, however, most of the existing approaches can only model the relative levels of risk. This paper reports the development of a method for the quantitative assessment of the risk of multiple hazards based on information diffusion. This method was used to assess the risks of loss of human lives from 11 types of meteorological hazards in China at the prefectural and provincial levels. Risk curves of multiple hazards were obtained for each province and the risks of 10-year, 20-year, 50-year, and 100-year return periods were mapped. The results show that the provinces (municipalities, autonomous regions) in southeastern China are at higher risk of multiple meteorological hazards as a result of their geographical location and topography. The results of this study can be used as references for the management of meteorological disasters in China. The model can be used to quantitatively calculate the risks of casualty, direct economic losses, building collapse, and agricultural losses for any hazards at different spatial scales.

Dissolution of oxygen reduction electrocatalysts in an acidic environment: density functional theory study.

Density functional theory is employed to determine the reaction thermodynamics of a group of chemical and electrochemical reactions chosen to investigate the dissolution of metal atoms from oxygen reduction reaction catalysts in an acid medium. Once a set of thermodynamically allowed reactions is established, those reactions are selected to investigate the relative stabilities of Pt atoms and of other transition metal atoms (Ir, Pd, Rh, Ni, and Co) toward the dissolution reactions. The dissolution reactions that are found thermodynamically favorable are electrochemical and involve adsorbed oxygenated compounds that are intermediate species of the oxygen reduction reaction. Iridium is found to be the most stable among the various pure metals in comparison to Pt. Most of the metals alloyed with Pt cause a decrease of the Pt stability against dissolution, except for Ni, which does not affect it. On the other hand, the influence of Pt on the stability of the second metal in the alloy follows the same trend as in pure metal catalysts, with Ir being the most stable. When both atoms in a PtM alloy are involved in dissolution reactions, alloyed Ir is also found more stable than Pt in a given dissolution reaction, and the same behavior is found in alloyed Co for most of the reactions studied.

Does the decomposition of peroxydicarbonates and diacyl peroxides proceed in a stepwise or concerted pathway?

Møller-Plesset perturbation theory and density functional theory calculations are used to study decomposition mechanisms of polymerization initiators, such as diethyl peroxydicarbonate, trifluoroacetyl peroxide, and acetyl peroxide, which possess a general structure of RC(O)OO(O)CR. It is found that the decomposition of initiators with electron-donating R groups follows two favorable stepwise pathways: a two-bond cleavage mechanism in which the O-O single bond and one of R-C bonds of [R-C(O)O-O(O)C-R] break simultaneously followed by decomposition of the R-C(O)O(*) radical and a one-bond cleavage mechanism in which the single O-O bond cleavage produces a carboxyl radical pair and a subsequent decomposition of the carboxyl radicals. It is also found that the initiators with electron-withdrawing R groups follow the two-bond cleavage pathway only. Geometrical and energetic analyses indicate that despite the similar structures of the peroxydicarbonates, quite different decomposition energy barriers are determined by the nature of the R groups.