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Plant sulfate transporters (SULTR) mediate absorption and distribution of sulfate (SO 4 2− ) and are essential for plant growth; however, our understanding of their structures and functions remains inadequate. Here we present the structure of a SULTR from Arabidopsis thaliana , AtSULTR4;1, in complex with SO 4 2− at an overall resolution of 2.8 Å. AtSULTR4;1 forms a homodimer and has a structural fold typical of the SLC26 family of anion transporters. The bound SO 4 2− is coordinated by side-chain hydroxyls and backbone amides, and further stabilized electrostatically by the conserved Arg393 and two helix dipoles. Proton and SO 4 2− are co-transported by AtSULTR4;1 and a proton gradient significantly enhances SO 4 2− transport. Glu347, which is ~7 Å from the bound SO 4 2− , is required for H + -driven transport. The cytosolic STAS domain interacts with transmembrane domains, and deletion of the STAS domain or mutations to the interface compromises dimer formation and reduces SO 4 2− transport, suggesting a regulatory function of the STAS domain. Plant sulfate transporters mediate absorption and distribution of sulfate. Here the authors present functional assays and a cryo-EM structure of the Arabidopsis SULTR4;1 transporter identifying key domains for dimerization, substrate binding and coupling of transport activity to a proton gradient.

Phosphatidylcholine (PC) is the most abundant phospholipid in eukaryotic cell membranes. In eukaryotes, two highly homologous enzymes, cholinephosphotransferase-1 (CHPT1) and choline/ethanolamine phosphotransferase-1 (CEPT1) catalyze the final step of de novo PC synthesis. CHPT1/CEPT1 joins two substrates, cytidine diphosphate-choline (CDP-choline) and diacylglycerol (DAG), to produce PC, and Mg 2+ is required for the reaction. However, mechanisms of substrate recognition and catalysis remain unresolved. Here we report structures of a CHPT1 from Xenopus laevis (xlCHPT1) determined by cryo-electron microscopy to an overall resolution of ~3.2 Å. xlCHPT1 forms a homodimer, and each protomer has 10 transmembrane helices (TMs). The first 6 TMs carve out a cone-shaped enclosure in the membrane in which the catalysis occurs. The enclosure opens to the cytosolic side, where a CDP-choline and two Mg 2+ are coordinated. The structures identify a catalytic site unique to eukaryotic CHPT1/CEPT1 and suggest an entryway for DAG. The structures also reveal an internal pseudo two-fold symmetry between TM3-6 and TM7-10, and suggest that CHPT1/CEPT1 may have evolved from their distant prokaryotic ancestors through gene duplication. CDP-alcohol phosphatidyltransferase (CDP-AP) is a family of membrane-embedded enzymes that synthesize phospholipids. The authors report structural and functional studies of a eukaryotic CDP-AP and reveal a catalytic center and structural fold different from these of prokaryotic homologs.

Background Improving quality of life (QoL) has been one of the goals of health care for people living with oral cancer. This study aimed to assess QoL and investigate the effects of stigma, hope, and social support on QoL among Chinese oral cancer patients. Methods A cross-sectional study was conducted at the Department of Stomatology, Shengjing Hospital of China Medical University and Stomatology Hospital of China Medical University in Liaoning Province, China, between May 2016 and October 2017. A total of 230 oral cancer patients were recruited to complete a questionnaire including the Functional Assessment of Cancer Therapy-Head and Neck (FACT-H&N), the Social Impact Scale (SIS), the Herth Hope Index (HHI) and the Multidimensional Scale of Perceived Social Support (MSPSS). Univariate one-way ANOVA/t-test, Person’s r and hierarchical linear regression analysis were conducted to explore the factors influencing QoL and the relationships between stigma, hope, perceived social support and QoL. Results The mean QoL score was 90.85 ± 20.15 among the patients with oral cancer. Stigma was negatively related to QoL, explaining 39.3% of the variance. In addition, hope and perceived social support were positively associated with QoL, explaining 8.1% of the variance. Conclusion Overall, Chinese patients with oral cancer suffer from low QoL. Stigma was significantly and negatively associated with QoL, while hope and perceived social support were positively associated with QoL. Oral cancer patients’ psychological states should be addressed, and adequate intervention based on positive psychological resources should be provided to improve the QoL of patients with oral cancer.

The classroom environment plays a potentially important role in shaping the emotions and behavior of adolescents. However, few studies have focused on this factor. The aim of this study was to explore the association between the classroom environment and emotional and behavioral problems among Chinese adolescents while also considering personality-and family-related factors. This cross-sectional study was conducted in November and December, 2009. A set of questionnaires, including the Strengths and Difficulties Questionnaire (SDQ), the Eysenck Personality Questionnaire (EPQ), the Family Environment Scale (FES), the Questionnaire on Teacher Interaction (QTI), and the Center for Epidemiological Studies- Depression Scale (CES-D), were distributed to participants. A total of 5,433 Chinese adolescent students (aged 9-18) and 244 classroom teachers in Liaoning Province were ultimately included in the study. Hierarchical linear modeling was used to explore the factors associated with emotional and behavioral problems. Multilevel analyses revealed that adolescent emotional and behavioral problems significantly varied among classrooms. Although personality and family characteristics exerted the greatest influence on adolescents' emotions and behavior at the individual-level, interactions between classroom teachers and students increasingly affected adolescents with respect to age at the class-level. A mild positive association was found between adolescents' mental health problems and the mental health of teachers. This study focused on the classroom environment in order to understand Chinese adolescent mental health problems, the findings of which highlight important implications for policymakers and educators. The results underscore the importance of establishing a comfortable classroom climate by improving teacher-student interactions and meeting specific needs at different school stages, thus promoting a climate of positive mental health among Chinese adolescents.

The prevalence of depressive and anxiety symptoms and their associated factors in bladder and renal cancer patients are not well evaluated in China. Given the growing attention to positive psychological constructs in the field of oncology, it is necessary to explore the effects of these constructs on depressive and anxiety symptoms. This study aims to explore the associations of psychological stress with depressive and anxiety symptoms among Chinese bladder and renal cancer patients and the mediating role of resilience in these relationships. A cross-sectional study was conducted at the First Affiliated Hospital of China Medical University in Liaoning province. 327 bladder cancer patients and 268 renal cancer patients completed questionnaires on demographic variables, the Center for Epidemiologic Studies Depression Scale, Zung Self-Rating Anxiety Scale, Resilience Scale-14, and Perceived Stress Scale-10 during the period from July 2013 to July 2014. Hierarchical linear regression analyses were performed to explore the mediating role of resilience. The prevalence of depressive and anxiety symptoms was 78.0% and 71.3% in bladder cancer patients, and 77.6% and 68.3% in renal cancer patients. Psychological stress was positively related to depressive and anxiety symptoms, while resilience was negatively related to these symptoms. Resilience partially mediated the relations of psychological stress with depressive and anxiety symptoms. The high prevalence of depressive and anxiety symptoms among Chinese bladder and renal cancer patients should receive more attention from medical institutions and government agencies. In addition to reducing depressive and anxiety symptoms, resilience development should be included in depression and anxiety prevention and treatment strategies in China.

Diacylglycerol O -acyltransferase 1 (DGAT1) synthesizes triacylglycerides and is required for dietary fat absorption and fat storage in humans 1 . DGAT1 belongs to the membrane-bound O -acyltransferase (MBOAT) superfamily, members of which are found in all kingdoms of life and are involved in the acylation of lipids and proteins 2 , 3 . How human DGAT1 and other mammalian members of the MBOAT family recognize their substrates and catalyse their reactions is unknown. The absence of three-dimensional structures also hampers rational targeting of DGAT1 for therapeutic purposes. Here we present the cryo-electron microscopy structure of human DGAT1 in complex with an oleoyl-CoA substrate. Each DGAT1 protomer has nine transmembrane helices, eight of which form a conserved structural fold that we name the MBOAT fold. The MBOAT fold in DGAT1 forms a hollow chamber in the membrane that encloses highly conserved catalytic residues. The chamber has separate entrances for each of the two substrates, fatty acyl-CoA and diacylglycerol. DGAT1 can exist as either a homodimer or a homotetramer and the two forms have similar enzymatic activity. The N terminus of DGAT1 interacts with the neighbouring protomer and these interactions are required for enzymatic activity. The structure of human diacylglycerol O -acyltransferase 1, a membrane protein that synthesizes triacylglycerides, is solved with cryo-electron microscopy, providing insight into its function and mechanism of enzymatic activity.

Background Burnout among nurses not only threatens their own health, but also that of their patients. Exploring risk factors of nurse’ burnout is important to improve nurses’ health and to increase the quality of health care services. This study aims to explore the relationship between work-family conflict and burnout among Chinese female nurses and the mediating role of psychological capital in this relationship. Methods This cross-sectional study was performed during the period of September and October 2010. A questionnaire that consisted of the Maslach Burnout Inventory-General Survey (MBI-GS), the work-family conflict scale and the psychological capital questionnaire (PCQ-24) scale, as well as demographic and working factors, was distributed to nurses in Liaoning province, China. A total of 1,332 individuals (effective response rate: 78.35%) became our subjects. Hierarchical linear regression analyses were performed to explore the mediating role of psychological capital. Results Both work interfering family conflict and family interfering work conflict were positively related with emotional exhaustion and cynicism. However, work interfering family conflict was positively related with professional efficacy whereas family interfering work conflict was negatively related with it. Psychological capital partially mediated the relationship of work interfering family conflict with emotional exhaustion and cynicism; and partially mediated the relationship of family interfering work conflict with emotional exhaustion, cynicism and professional efficacy. Conclusion Work-family conflict had effects on burnout and psychological capital was a mediator in this relationship among Chinese nurses. Psychological capital was a positive resource for fighting against nurses’ burnout.

Background Resilience has been linked to psychological adaptation to many challenging life events. The present study aims to explore the level of resilience in oral cancer patients and the key factors associated with resilience, and to evaluate the relationship between resilience and anxiety. Methods A multiple center cross-sectional study was carried out for Chinese patients with oral cancer between May 2016 and October 2017 in the Stomatology Hospital of China Medical University and Department of Stomatology, Shengjing Hospital of China Medical University. Two hundred and thirty oral cancer patients replied to the questionnaires on resilience, hope, perceived social support, optimism, perceived stress and anxiety which were measured with Resilience Scale-14 (RS-14), Herth Hope Index (HHI), Multidimensional Scale of Perceived Social Support (MSPSS), Revised Life Orientation Test (LOT-R), Perceived Stress Scale-10 (PSS-10) and Zung Self-Rating Anxiety Scale (SAS), respectively. Univariate one-way ANOVA/t-test, Pearson’s r and hierarchical linear regression analysis were conducted to explore the influence factors of resilience and the relationship between resilience and anxiety. Results The level of resilience was 67.93 ± 12.65. Resilience was positively correlated with hope, optimism and perceived social support, and negatively correlated with perceived stress. Hierarchical linear regression analysis showed that hope (β = 0.386, P  < 0.01), optimism (β = 0.190, P  < 0.01) and education (β = 0.175, P < 0.01) were positively associated with resilience. The three variables in combination could explain 48.9% of the total variance in resilience. Higher level of resilience was associated less anxiety symptoms (X 2  = 39.216, p  = 0.000); and there was linear trend between resilience level and anxiety level among patients with oral cancer (X 2  = 35.624, p  = 0.000). Conclusion Patients with oral cancer in China had moderate level of resilience. Hope, optimism and education were positively and significantly associated with resilience, indicating that higher level of hope, optimism and education may improve resilience in oral cancer patients, which in turn may help alleviate anxiety symptoms in patients.

Background The psychological distress of medical students has been widely acknowledged. However, few studies focused on positive well-being among medical students. The purpose of this study was to investigate related demographic factors of life satisfaction among Chinese medical students, to examine the relationship between stress and life satisfaction among this group of people, and to explore the mediating role of resilience in this relationship. Methods This multicenter cross-sectional study was carried out in June 2014. Self-reported questionnaires consisting of Perceived Stress Scale (PSS), Wagnild and Young Resilience Scale (RS-14), Satisfaction with Life Scale (SWLS), as well as demographic section were distributed to students at four medical colleges and universities in Liaoning province, China. A total of 2925 students (effective response rate: 83.6%) became our subjects. Hierarchical linear regression models were used to explore the mediating role of resilience. Results Among the demographic factors, life satisfaction was significantly different in gender (P = 0.001) and study programs (P < 0.001). Stress was negatively correlated with life satisfaction (r = −0.35, P < 0.01). After adjusting for the demographic factors, stress accounted for 12% of the variance in life satisfaction (β = −0.34, P < 0.001) while resilience explained an additional 18% of the variance (β = 0.46, P < 0.001). Resilience functioned as a partial mediator in the relationship between stress and life satisfaction among Chinese medical students. Conclusions Both stress and resilience played a big role in life satisfaction among Chinese medical students. Besides reducing perceived stress, the university authorities should adopt evidence-based intervention strategies to enhance their resilience in order to promote life satisfaction among the students.