Pyrazine-Functionalized Donor-Acceptor Covalent Organic Frameworks for Enhanced Photocatalytic H2 Evolution with High Proton Transport.

The well-defined 2D or 3D structure of covalent organic frameworks (COFs) makes it have great potential in photoelectric conversion and ions conduction fields. Herein, a new donor-accepter (D-A) COF material, named PyPz-COF, constructed from electron donor 4,4',4″,4'″-(pyrene-1,3,6,8-tetrayl)tetraaniline and electron accepter 4,4'-(pyrazine-2,5-diyl)dibenzaldehyde with an ordered and stable π-conjugated structure is reported. Interestingly, the introduction of pyrazine ring endows the PyPz-COF a distinct optical, electrochemical, charge-transfer properties, and also brings plentiful CN groups that enrich the proton by hydrogen bonds to enhance the photocatalysis performance. Thus, PyPz-COF exhibits a significantly improved photocatalytic hydrogen generation performance up to 7542 µmol g-1 h-1 with Pt as cocatalyst, also in clear contrast to that of PyTp-COF without pyrazine introduction (1714 µmol g-1 h-1 ). Moreover, the abundant nitrogen sites of the pyrazine ring and the well-defined 1D nanochannels enable the as-prepared COFs to immobilize H3 PO4 proton carriers in COFs through hydrogen bond confinement. The resulting material has an impressive proton conduction up to 8.10 × 10-2 S cm-1 at 353 K, 98% RH. This work will inspire the design and synthesis of COF-based materials with both efficient photocatalysis and proton conduction performance in the future.

[Effects of Simulated Nitrogen Deposition on Soil Microbial Carbon Metabolism in Calamagrostis angustifolia Wetland in Sanjiang Plain].

Atmospheric nitrogen deposition has a crucial impact on the structure and function of soil microorganisms of wetland ecosystems. Therefore, carrying out a study on the effects of soil carbon metabolism capacity has a great significance for the protection and utilization of wetland ecosystems. In this study, the effects of simulated nitrogen deposition on the carbon metabolic capacity of soil microorganisms in Calamagrostis angustifolia wetland for five consecutive years was investigated using Biolog-Eco technology. The results showed:① soil water content (SMC), pH, nitrate nitrogen (NO3-), ammonium nitrogen (NH4+), dissolved organic carbon (DOC), and total nitrogen (TN) contents were significantly different (P<0.05) under different nitrogen deposition conditions. ② The average well color development (AWCD) values of soil microorganisms within different N depositions were in the order of CK (control)>HN (high nitrogen treatment)>LN (low nitrogen treatment). LN significantly reduced the Shannon diversity index of soil microorganisms, and HN significantly reduced the Pielou index of soil microorganisms (P<0.05). ③ LN significantly inhibited the intensity of the utilization of carbohydrates, alcohols, amines, and acids by soil microorganisms (P<0.05); HN significantly promoted the utilization of esters by microorganisms, but HN caused soil microorganisms to inhibit the carbon sources of carbohydrates, amines, and acids (P<0.05). ④ Redundancy analysis showed that NH4+, DOC, and pH were the main environmental factors affecting the functional diversity of soil microbial communities in Calamagrostis angustifolia wetland in the Sanjiang Plain. Long-term nitrogen deposition will lead to the reduction in soil microbial functional diversity; the microbial activity related to the utilization of carbon source substrates is also significantly reduced, and the ability of microorganisms to utilize a single carbon source substrate also changes.

Anaerobic digestates grown oleaginous microalgae for pollutants removal and lipids production.

Anaerobic digestates were potential mediums for cultivating oleaginous microalgae, but their various components brought uncertainties for aglal growth and lipids production. In this study, three microalgae strains were tested to grow on four typical anaerobic digestates. The results showed that anaerobic food wastewater was an optimal medium for C. pyrenoidosa and S. obliquus culture (N. oleoabundanst cannot survive), achieving the highest biomass (2.15-2.32 g L-1) and lipids production (20.6-32.5 mg L-1·d-1). In contrast, three microalgae strains could grow suboptimally in anaerobic municipal (0.79-0.95 g L-1) and toilet (0.92-1.40 g L-1) wastewater, but showed poor performances in anaerobic swine wastewater. The growth of microalgae removed 40.9-63.4% of TOC, 83.7-96.3% of NH4+-N and 70.3-89.4% of TP in the three ADs. In addition, it was unfortunately found that the lipids content and saturation degree in fatty acids significantly decreased in ADs with sufficient nutrients. It suggests that some measures should be taken to balance biomass, lipids production and quality for cultivating microalgae in anaerobic digestates.

A Cross-Sectional Study of Individual Learning Passion in Medical Education: Understanding Self-Development in Positive Psychology.

Background: Boosting the individual learning passion of medical students is a novel approach to improve their academic performance. It facilitates the medical education reform, motivating both policymakers and educators to focus on the function of positive psychology in the career development of medical students. Therefore, this study aimed (1) to assess the status of two types of learning passion; (2) to clarify the relationship between self-esteem and two types of learning passion among Chinese medical students; (3) to examine the mediating role of psychological capital (PsyCap) in the relationship between self-esteem and two types of learning passion, respectively; and (4) to identify the moderating role of professional identity in the relationship between PsyCap and two types of learning passion, respectively. Methods: A cross-sectional online survey was conducted from April to June 2016 in China. A total of 1,218 valid questionnaires (effective completion rate: 67.93%) were collected from four medical schools. Results: Self-esteem significantly and positively influenced medical students' PsyCap (ß = 0.637, P < 0.01) and two types of learning passion, including harmonious learning passion (ß = 0.589, P < 0.01) and obsessive learning passion (ß = 0.436, P < 0.01). PsyCap fully mediated the relationship (ß = 0.578, P < 0.01) between self-esteem and harmonious learning passion positively, whereas it suppressed the relationship (ß = 0.490, P < 0.01) between self-esteem and obsessive learning passion. Further, professional identity significantly moderated the correlation between PsyCap and harmonious learning passion (ß = -0.554, P < 0.05), rather than obsessive learning passion (P > 0.05). Conclusion: Two types of learning passion of medical students are positively influenced by self-esteem and PsyCap. Medical students with high-level self-esteem should possess strong PsyCap, which augments their harmonious as well as obsessive learning passion. Moreover, the positive effect of medical students' PsyCap on harmonious learning passion is more notable among those with a lower professional identity. Finally, this study argues that strengths-based interventions of self-esteem and PsyCap are a beneficial approach for future enhancing learning passion in the domain of medical education.

[Effects of water levels in heterogeneous habitats on sexual reproductive allocation of Deyeuxia angustifolia.] / å¼‚è´¨ç”Ÿå¢ƒæ°´ä½å·®å¼‚å¯¹å°å¶ç« æœ‰æ€§ç¹æ®–åˆ†é çš„å½±å“.

Taking Deyeuxia angustifolia as the research object, a representative plant of wetland in Sanjiang Plain, we analyzed the variations of individual size and biomass among the habitats of swamp wetlands, swampy meadows, typical meadows and miscellaneous grass meadows, and the relationship between reproductive components and plant biomass. We explored the effects of water level on individual biomass and reproductive allocation of D. angustifolia in different types of wetlands. The results showed that plant biomass, height and the characteristics of sexual reproduction significantly decreased with the increases of water level. The reproductive thresholds of D. angustifolia in miscellaneous grass meadow, typical meadow, swampy meadow, and swamp wetland were 0.245, 0.149, 0.148 and 0.157 g, respectively. There was a significantly negative correlation between plant size and reproductive allocation in three habitats except swampy meadow. Compared with individual size, soil water content had a stronger effect on reproductive allocation of D. angustifolia. The different investment between individual size and reproductive allocation in different habitats was the basic condition that contributes to the good ecological adaptability of D. angustifolia.

Pharmacological inhibition of MyD88 suppresses inflammation in tubular epithelial cells and prevents diabetic nephropathy in experimental mice.

Emerging evidence shows that chronic inflammation mediated by toll-like receptors (TLRs) contributes to diabetic nephropathy. Myeloid differentiation primary-response protein-88 (MyD88) is an essential adapter protein of all TLRs except TLR3 in innate immunity. It is unclear whether MyD88 could be a therapeutic target for diabetic nephropathy. Here, we used a new small-molecule MyD88 inhibitor, LM8, to examine the pharmacological inhibition of MyD88 in protecting kidneys from inflammatory injury in diabetes. We showed that MyD88 was significantly activated in the kidney of STZ-induced type 1 diabetic mice in tubular epithelial cells as well as in high glucose-treated rat tubular epithelial cells NRK-52E. In cultured tubular epithelial cells, we show that LM8 (2.5-10 µM) or MyD88 siRNA attenuated high-concentration glucose-induced inflammatory and fibrogenic responses through inhibition of MyD88-TLR4 interaction and downstream NF-κB activation. Treatment with LM8 (5, 10 mg/kg, i.g.) significantly reduced renal inflammation and fibrosis and preserved renal function in both type 1 and type 2 diabetic mice. These renoprotective effects were associated with reduced MyD88-TLR4 complex formation, suppressed NF-κB signaling, and prevention of inflammatory factor expression. Collectively, our results show that hyperglycemia activates MyD88 signaling cascade to induce renal inflammation, fibrosis, and dysfunction. Pharmacological inhibition of MyD88 may be a therapeutic approach to mitigate diabetic nephropathy and the inhibitor LM8 could be a potential candidate for such therapy.

Flavokawain B alleviates LPS-induced acute lung injury via targeting myeloid differentiation factor 2.

Acute lung injury (ALI) is a sudden onset systemic inflammatory response. ALI causes severe morbidity and death and currently no effective pharmacological therapies exist. Natural products represent an excellent resource for discovering new drugs. Screening anti-inflammatory compounds from the natural product bank may offer viable candidates for molecular-based therapies for ALI. In this study, 165 natural compounds were screened for anti-inflammatory activity in lipopolysaccharide (LPS)-challenged macrophages. Among the screened compounds, flavokawain B (FKB) significantly reduced LPS-induced pro-inflammatory IL-6 secretion in macrophages. FKB also reduced the formation of LPS/TLR4/MD2 complex by competitively binding to MD2, suppressing downstream MAPK and NF-κB signaling activation. Finally, FKB treatment of mice reduced LPS-induced lung injury, systemic and local inflammatory cytokine production, and macrophage infiltration in lungs. These protective activities manifested as increased survival in the ALI model, and reduced mortality upon bacterial infection. In summary, we demonstrate that the natural product FKB protects against LPS-induced lung injury and sepsis by interacting with MD2 and inhibiting inflammatory responses. FKB may potentially serve as a therapeutic option for the treatment of ALI.

Mobile Phone Addiction and Academic Procrastination Negatively Impact Academic Achievement Among Chinese Medical Students.

The problem of mobile phone addiction and academic procrastination among medical students has been widely acknowledged. This study aimed to explore the influence of demographic factors on mobile phone addiction, academic procrastination, and academic achievement among medical students. Further, it investigated the association between mobile phone addiction, academic procrastination, and academic achievement. This cross-sectional study was conducted between May and June 2019. A total of 3 511 medical students participated in an online questionnaire survey (effective response rate = 81.7%). Demographic factors, the Scale of Academic Achievement, the short scale of the Mobile Phone Problem Use (MPPUS-10), and the Academic Procrastination Scale-Short (APS-S) were used. Hierarchical multiple regression analysis revealed that the average scores for academic procrastination, mobile phone addiction, and academic achievement were 2.66 ± 0.91, 5.13 ± 1.53, and 4.51 ± 0.71, respectively. Moreover, there were significant differences in gender, grade, leadership experience, and family monthly income across mobile phone addiction, academic procrastination, and academic achievement. Mobile phone addiction was negatively associated with learning dedication, learning performance, and relationship facilitation. Academic procrastination was negatively associated with learning dedication, learning performance, relationship facilitation, and objective achievement. Mobile phone addiction and academic procrastination was revealed as prevalent among Chinese medical students, and negatively influences their academic achievement. It is critical to establish a more efficient learning environment for Chinese medical students to minimize the negative impact of mobile phone addiction and academic procrastination.

Contribution of Character Strengths to Psychology Stress, Sleep Quality, and Subjective Health Status in a Sample of Chinese Nurses.

Objectives: The main objectives of this study were to describe the current state of character strengths (CSs) of nurses; explain how they affect stress, sleep quality, and subjective health status; and reveal the mediating role of stress for the subject matter on the association between CSs, sleep quality, and subjective health status. Methods: A cross-sectional online survey was conducted from September to October 2020 in China. A multistage stratified sampling method was used, and 1,221 valid questionnaires across 100 cities in 31 provinces were collected. Results: For the participants in this survey, the three dimensions of CSs ranging from high to low were caring (4.20 ± 0.640), self-control (3.53 ± 0.763), and inquisitiveness (3.37 ± 0.787). There was difference in CSs scores across age (F = 8.171, P < 0.01), professional categories (F = 5.545, P < 0.01), and job tenure (F = 9.470, P < 0.01). The results showed that CSs significantly affected the psychological stress (ß = -0.365, P< 0.01), sleep quality (ß = 0.312, P< 0.01), and subjective health (ß = 0.398, P< 0.01) of nurses. Moreover, psychological stress partially mediated the association between CSs and both types of health outcomes. Conclusion: In China, the CSs of nurses are at high levels. We find that nurses with high-level CSs are likely to experience less psychological stress and exhibit healthy psycho-physiological responses, which contribute to positive health outcomes. Finally, our study argues that strength-based interventions of positive psychology in hospitals should be provided to minimize threats to the physical and psychological health of health professionals, which is a beneficial choice for future hospital reforms in the domain of occupational health management.

The Association Among Achievement Goal Orientations, Academic Performance, and Academic Well-Being Among Chinese Medical Students: A Cross-Sectional Study.

Learning motivation is a significant factor that ensures quality in medical education, and might affect the academic performance and well-being of medical students. This study aimed to explore the status of achievement goal orientations among medical students in China and to further identify the association among academic performance, academic well-being, and achievement goal orientations. Data were collected through a cross-sectional, anonymous survey conducted with 3,511 respondents (effective response rate = 81.7%), from four medical universities in China, and demographic factors, achievement goal orientations, academic performance, and academic well-being were assessed. The average score of achievement goal orientations of Chinese medical students suggested a difference in demographic factors, including sex, year of study, experience of leadership cadre, and family income. Both mastery and performance-avoidance goals were associated with academic performance, subjective academic stress, subjective learning adaptability, subjective sleep quality, and subjective well-being. Performance-approach goals were related to academic performance, subjective academic stress, and subjective learning adaptability. The achievement goal orientations of the medical students in this study were at a middle level. The findings emphasize the importance of mastery goals for promoting the academic performance and well-being of medical students. More care and attention toward achievement goal orientations can be beneficial for the improvement of the academic performance and well-being among medical students.