Riboflavin-loaded carbon cloth aids the anaerobic digestion of cow dung by promoting direct interspecies electron transfer.

Cow dung generates globally due to increased beef and milk consumption, but its treatment efficiency remains low. Previous studies have shown that riboflavin-loaded conductive materials can improve anaerobic digestion through enhance direct interspecies electron transfer (DIET). However, its effect on the practical anaerobic digestion of cow dung remained unclear. In this study, carbon cloth loaded with riboflavin (carbon cloth-riboflavin) was added into an anaerobic digester treating cow dung. The carbon cloth-riboflavin reactor showed a better performance than other two reactors. The metagenomic analysis revealed that Methanothrix on the surface of the carbon cloth predominantly utilized the CO2 reduction for methane production, further enhanced after riboflavin addition, while Methanothrix in bulk sludge were using the acetate decarboxylation pathway. Furthermore, the carbon cloth-riboflavin enriched various major methanogenic pathways and activated a large number of enzymes associated with DIET. Riboflavin's presence altered the microbial communities and the abundance of functional genes relate to DIET, ultimately leading to a better performance of anaerobic digestion for cow dung.

Empathy in undergraduate medical students: a multi-center cross-sectional study in China.

BACKGROUND: Fostering empathy has been continuously emphasized in the global medical education. Empathy is crucial to enhance patient-physician relationships, and is associated with medical students' academic and clinical performance. However, empathy level of medical students in China and related influencing factors are not clear. METHODS: This was a cross-sectional study among medical students in 11 universities. We used the Jefferson Scale of Empathy Student-version of Chinese version to measure empathy level of medical students. Factors associated with empathy were identified by the univariate and multivariate logistic regression analyses. Based on the variables identified above, the nomogram was established to predict high empathy probability of medical students. Receiver operating characteristic curve, calibration plot and decision curve analysis were used to evaluate the discrimination, calibration and educational utility of the model. RESULTS: We received 10,901 samples, but a total of 10,576 samples could be used for further analysis (effective response rate of 97.02%). The mean empathy score of undergraduate medical students was 67.38 (standard deviation = 9.39). Six variables including gender, university category, only child or not, self-perception doctor-patient relationship in hospitals, interest of medicine, Kolb learning style showed statistical significance with empathy of medical students (P < 0.05). Then, the nomogram was established based on six variables. The validation suggested the nomogram model was well calibrated and had good utility in education, as well as area under the curve of model prediction was 0.65. CONCLUSIONS: We identify factors influencing empathy of undergraduate medical students. Moreover, increasing manifest and hidden curriculums on cultivating empathy of medical students may be needed among medical universities or schools in China.

Unraveling the Role of Non-Fullerene Acceptor with High Dielectric Constant in Organic Solar Cells.

Increasing the relative dielectric constant is a constant pursuit of organic semiconductors, but it often leads to multiple changes in device characteristics, hindering the establishment of a reliable relationship between dielectric constant and photovoltaic performance. Herein, a new non-fullerene acceptor named BTP-OE is reported by replacing the branched alkyl chains on Y6-BO with branched oligoethylene oxide chains. This replacement successfully increases the relative dielectric constant from 3.28 to 4.62. To surprise, BTP-OE offers consistently lower device performance relative to Y6-BO in organic solar cells (16.27% vs 17.44%) due to the losses in open-circuit voltage and fill factor. Further investigations unravel that BTP-OE has resulted in reduced electron mobility, increased trap density, enhanced first order recombination, and enlarged energetic disorder. These results demonstrate the complex relationship between dielectric constant and device performance, which provide valuable implications for the development of organic semiconductors with high dielectric constant for photovoltaic application.

Medical students' academic satisfaction: Social cognitive factors matter.

PURPOSE: Academic satisfaction (AS)-the extent to which people enjoy their role or experiences as medical students-has important implications for well-being and career development. This study explores the relationships between social cognitive factors and AS in a Chinese medical education context. METHOD: The social cognitive model of academic satisfaction (SCMAS) was adopted as the theoretical framework. Within this model, AS is assumed to be related to social cognitive factors-environmental supports, outcome expectations, perceived goal progress and self-efficacy. Demographic variables, financial pressure, college entrance examination scores and social cognitive constructs in SCMAS were collected. To explore the relationships between medical students' social cognitive factors and AS, hierarchical multiple regression analyses were performed. RESULTS: The final sampled data consisted of 127 042 medical students from 119 medical institutions. Demographic variables, financial pressure and college entrance examination scores were first entered in Model 1, explaining 4% of the variance in AS. Social cognitive factors were entered in Model 2, explaining an additional 39% of the variance. Medical students would report higher levels of AS when they (a) held strong confidence in their skills needed for success in studying medicine (ß = 0.20, p < 0.05), (b) had optimistic beliefs about the outcome of studying medicine (ß = 0.40, p < 0.05), (c) felt that they were making good progress in studying medicine (ß = 0.06, p < 0.05) and (d) believed that they received adequate environmental support (ß = 0.25, p < 0.05). The outcome expectations showed the strongest correlation with AS, and each 1-point increase was associated with 0.39 points on the AS score, controlling for all other factors in the model. CONCLUSIONS: Social cognitive factors play an important role in medical students' AS. Intervention programmes or courses aiming to improve medical students' AS are advised to consider social cognitive factors.

The impact of student engagement on satisfaction with medical education in china: a supplementary perspective.

As one of the indicators reflecting student well-being in medical education practice, student satisfaction is no doubt an important topic. Instead of exploring student satisfaction from the perspectives of education quality and organizational factors, this study focused on student engagement to explore the impact of it on student satisfaction with medical education in China. Student engagement refers to students' actions, efforts and persistence, indicating both time and energy students invested in educationally purposeful activities, especially academic activities. The data used in this study came from the first national survey of clinical undergraduates-the China Medical Student Survey-in which 10,062 clinical medical undergraduates in 33 medical schools participated. We developed a model of medical student engagement and satisfaction and utilized descriptive statistics, ordered logit regression, and path analysis to describe the relationship between medical student engagement and satisfaction. In this study, student engagement was categorized into behavioral, emotional and cognitive dimensions. The findings showed that medical student satisfaction was relatively low and was significantly affected by student satisfaction, especially the behavioral engagement in clinical rotations and professional identity of emotional engagement. These findings could put a supplementary perspective on improving student satisfaction through student engagement, and offer notable implications for future research and practice.

A multi-center cross-sectional study on identification of influencing factors of medical students' emotional engagement in China.

BACKGROUND: Studies exploring influencing factors of emotional engagement among medical students are scarce. Thus, we aimed to identify influencing factors of medical students' emotional engagement. METHODS: We carried out a multi-center cross-sectional study among 10,901 medical students from 11 universities in China. The Chinese version of Utrecht Work Engagement Scale-Student version (UWES-S) was used to evaluate emotional engagement level of medical students. The predictors related to engagement level were determined by the logistic regression analysis. Furthermore, we constructed a nomogram to predict emotional engagement level of medical students. RESULTS: A total of 10,576 sample were included in this study. The mean emotional engagement score was 74.61(± 16.21). In the multivariate logistic regression model, we found that males showed higher engagement level compared with females [odds ratio (OR) (95% confidence interval (CI)): 1.263 (1.147, 1.392), P < 0.001]. Medical students from the second batches of medical universities had higher engagement level and from "Project 985" universities had lower engagement level compared with 211 project universities [OR (95%CI): 1.376 (1.093, 1.733), P = 0.007; OR (95%CI): 0.682 (0.535, 0.868), P = 0.002]. Medical students in grade 4 and grade 2 presented lower engagement level compared with in grade 1 [OR (95%CI): 0.860 (0.752, 0.983), P = 0.027; OR (95%CI): 0.861 (0.757, 0.980), P = 0.023]. Medical students lived in provincial capital cities had higher engagement level compared with in country [OR (95%CI): 1.176 (1.022, 1.354), P = 0.024]. Compared with eight-year emotional duration, medical students in other emotional duration (three-year and four-year) had lower engagement level [OR (95%CI): 0.762 (0.628, 0.924), P = 0.006]. Medical students' engagement level increased with increases of grade point average and interest in studying medicine. Medical students learned by converging style showed lower engagement level [OR (95%CI): 0.827 (0.722, 0.946), P = 0.006] compared with accommodating style. The model showed good discriminative ability (area under curve = 0.778), calibrating ability and clinical utility. CONCLUSIONS: We identified influencing factors of medical students' emotional engagement and developed a nomogram to predict medical students' emotional engagement level, providing reference and convenience for educators to assess and improve emotional engagement level of medical students. It is crucial for educators to pay more attention to emotional engagement of medical students and adopt effective strategies to improve their engagement level.

A Polyfluoroalkyl-Containing Non-fullerene Acceptor Enables Self-Stratification in Organic Solar Cells.

The elaborate control of the vertical phase distribution within an active layer is critical to ensuring the high performance of organic solar cells (OSCs), but is challenging. Herein, a self-stratification active layer is realised by adding a novel polyfluoroalkyl-containing non-fullerene small-molecule acceptor (NFSMA), EH-C8 F17 , as the guest into PM6:BTP-eC9 blend. A favourable vertical morphology was obtained with an upper acceptor-enriched thin layer and a lower undisturbed bulk heterojunction layer. Consequently, a power conversion efficiency of 18.03 % was achieved, higher than the efficiency of 17.40 % for the device without EH-C8 F17 . Additionally, benefiting from the improved charge transport and collection realised by this self-stratification strategy, the OSC with a thickness of 350 nm had an impressive PCE of 16.89 %. The results of the study indicate that polyfluoroalkyl-containing NFSMA-assisted self-stratification within the active layer is effective for realising an ideal morphology for high-performance OSCs.

Safety and Immunogenicity of a Recombinant Adenovirus Type-5-Vectored Coronavirus Disease 2019 (COVID-19) Vaccine With a Homologous Prime-Boost Regimen in Healthy Participants Aged ≥6 Years: A Randomized, Double-Blind, Placebo-Controlled, Phase 2b Trial.

BACKGROUND: We assessed the safety and immunogenicity of a recombinant adenovirus type-5 (Ad5)-vectored coronavirus disease 2019 (COVID-19) vaccine with homologous prime-boost regimens in healthy participants aged ≥6 years. METHODS: In this randomized, double-blind, placebo-controlled trial, participants received vaccine or placebo 56 days apart. Enzyme-linked immunosorbent assay (ELISA) antibodies to the receptor binding domain (RBD) and pseudovirus neutralizing antibodies were detected. Adverse events were monitored for 28 days following each vaccination. RESULTS: A total of 430 participants were enrolled in the study, with 30 participants aged 18-55 years (MID cohort), 250 aged ≥56 years (OLD cohort), and 150 aged 6-17 years (MIN cohort). Ad5-vectored COVID-19 vaccine induced significant RBD-specific ELISA antibodies that decreased with increasing age, with geometric mean titers (GMTs) of 1037.5 in the MIN cohort, 647.2 in the MID cohort, and 338.0 in the OLD cohort receiving 5 × 1010 viral particles on day 28 following boost vaccination. Pseudovirus neutralizing antibodies showed a similar pattern, with GMTs of 168.0 in the MIN cohort, 76.8 in the MID cohort, and 79.7 in the OLD cohort. A single dose in children and adolescents induced higher antibody responses than that elicited by 2 doses in adults, with GMTs of 1091.6 and 96.6 for ELISA antibody and neutralizing antibody, respectively. Homologous prime-boost vaccination was safe and tolerable. CONCLUSIONS: Ad5-vectored COVID-19 vaccine with a single dose was safe and induced robust immune responses in children and adolescents aged 6-17 years. A prime-boost regimen needs further exploration for Ad5-vectored COVID-19 vaccine.Ad5-vectored COVID-19 vaccine with a single dose was safe and tolerated, and induced robust immune responses in children and adolescents aged 6-17 years. The boosting effect on immune responses of the homologous prime-boost regime given 56 days apart was limited. CLINICAL TRIALS REGISTRATION: NCT04566770.

The relationship between medical student engagement in the provision of the school's education programme and learning outcomes.

INTRODUCTION: Student engagement in the provision of the school's education programme (educational student engagement) plays an important role in quality assurance in medical education. However, little is known whether this specific type of student engagement has effects on the learning outcomes for the involved medical students. METHODS: This study was based on a national-wide survey in China among medical students with 123,055 responses. The questionnaire was designed using international and Chinese national standards. T-test, analysis of variance, multivariate regression, and regression with interaction terms were used. RESULTS: Educational student engagement was positively associated with medical students' learning outcomes in Clinical Practice, Science and Scholarship, Health and Society, and Professionalism. Besides, the influence was heterogeneous among participants at different learning phases. Learning outcomes in Clinical Practice were strongly associated with educational student engagement efficiently at the Clinical Medical Education and the Clerkship Rotation phases, and learning outcomes in Science and Scholarship were best correlated with the Clerkship Rotation phase. CONCLUSION: Educational student engagement is positively associated with the learning outcomes, with the greatest effect on learning outcomes in Clinical Practice and the least effect in Professionalism. Besides, it has a greater impact on medical students at senior learning phases.

Still want to be a doctor? Medical student dropout in the era of COVID-19.

This research examines the intention of undergraduate medical students to withdraw from the medical profession and pursue a career in a different field upon graduation during COVID-19. We leverage the first and most comprehensive nationwide survey for medical education in China, which covered 98,668 enrolled undergraduate students from 90 out of 181 Chinese medical schools in 2020. We focus on these students' self-reported intention to leave the healthcare industry (the "dropout intention") before and after the outbreak of the epidemic. We also designed a randomized experiment to test whether and to what extent medical students dropout intention responded to an information nudge that highlighted the prosociality of health professionals in the fight against the virus. Results from a difference-in-differences model and a student fixed effect model suggest that after the onset of COVID-19, the proportion of Chinese undergraduate medical students with a dropout intention declined from 13.7% to 6.8%. Furthermore, the nudge information reduced the intent-to-drop-out probability by 0.8 additional percentage points for students in their early college years. There was large heterogeneity underneath the treatment effect. Specifically, we find that prior dropout intention and exposures to COVID-19-related information tended to mitigate the nudge effects. Data on students' actual dropout outcomes support our findings.

Funding of health professional education: China's 20-year process and a global comparison.

CONTEXT: Funding is an essential requirement for ensuring the quality of health professional education worldwide. Adequate funding is of immense significance in training health professionals. Due to the difficulty of accessing relevant data, quantitative research of the kind is scarce. OBJECTIVES: This study aims at analysing the trends of funding levels and funding sources for health professional institutions in China spanning the past 20 years and making a global comparison. METHODS: We used data from Ministry of Education (MOE) of the People's Republic of China to analyse its funding level and structure of funding sources of health professional education in China during 1998-2017. When analysing funding level, we used two indicators: total funding and funding per student. We chose the United States, and analysed its funding level and structure to allow easy comparison to the situation in China. The data from a Lancet report (Lancet, 376, 2010, 1923) were also used to analyse global funding status to make an international comparison. RESULTS: Funding levels of health professional institutions in China has increased significantly in the past 20 years, while the average annual growth rate of funding per student (4.5%) is lower than that of total funding (19.9%). In terms of the structure of funding sources, fiscal appropriation accounts for 51.1% on average, and tuition, fees and scientific research income explains 37.0%. CONCLUSION: From 1998 to 2017, the total funding and funding per student of HPE in China increased continuously, and the total funding increased at a faster rate. The increase in funding of HPE in China is closely related to the efforts of the Chinese government and the implementation of relevant policies. Even so, funding of HPE in China is likely to remain relatively low compared to other countries.

Students' initial perspectives on online learning experience in China during the COVID-19 outbreak: expanding online education for future doctors on a national scale.

BACKGROUND: During the early stage of COVID-19 outbreak in China, most medical undergraduate programs have to eventually embrace the maneuver of transferring to nearly 100% online-learning as a new routine for different curricula. And there is a lack of empirical evidence of effective medical education curriculum that has been completely implemented in an online format. This study summarizes medical students' perspectives regarding online-learning experience during the COVID-19 outbreak and presents reflection on medical education. METHODS: From February 21st to March 14th, 2020, the authors conducted survey of a nationally representative sample of undergraduate medical students from 90 medical schools in China. Participant demographics and responses were tabulated, and independent sample t-tests as well as multiple logistic regression models were used to assess the associations of demographic characteristics, prior online learning experience, and orientation with students' perspectives on the online learning experience. RESULTS: Among 118,030 medical students participated in the survey (response rate 52.4%), 99,559 provided valid data for the analysis. The sample is fairly nationally representative. 65.7% (65,389/99,559) supported great orientation and 62.1% (61,818/99,559) reported that they were satisfied with the ongoing online-learning experience. The most common problem students would encounter was the network congestion (76,277/99,559; 76.6%). Demographics, learning phases, and academic performance were associated with online-learning engagement and perceptions. Formal orientation and prior PU (perceived usefulness of online learning) were significantly positively associated with the satisfaction and evaluation of the online learning experience (p <  0.001). CONCLUSIONS: Data from this national survey indicates a relatively positive role of online learning as a formal teaching/learning approach in medical education. Considerations should be made regarding such application in aspects of students' different learning phases. We suggest that further policy interventions should be taken from technological, organizational, environmental, as well as individual aspects, to help improve the outcome of online learning for future doctors.

A Facile Synthesized Polymer Featuring B-N Covalent Bond and Small Singlet-Triplet Gap for High-Performance Organic Solar Cells.

High-efficiency organic solar cells (OSCs) largely rely on polymer donors. Herein, we report a new building block BNT and a relevant polymer PBNT-BDD featuring B-N covalent bond for application in OSCs. The BNT unit is synthesized in only 3 steps, leading to the facile synthesis of PBNT-BDD. When blended with a nonfullerene acceptor Y6-BO, PBNT-BDD afforded a power conversion efficiency (PCE) of 16.1 % in an OSC, comparable to the benzo[1,2-b:4,5-b']dithiophene (BDT)-based counterpart. The nonradiative recombination energy loss of 0.19 eV was afforded by PBNT-BDD. PBNT-BDD also exhibited weak crystallinity and appropriate miscibility with Y6-BO, benefitting of morphological stability. The singlet-triplet gap (ΔEST ) of PBNT-BDD is as low as 0.15 eV, which is much lower than those of common organic semiconductors (≥0.6 eV). As a result, the triplet state of PBNT-BDD is higher than the charge transfer (CT) state, which would suppress the recombination via triplet state effectively.

Copper sulfate-induced endoplasmic reticulum stress promotes hepatic apoptosis by activating CHOP, JNK and caspase-12 signaling pathways.

Copper (Cu), a transition metal, is an essential trace element in human and animal nutrition at low concentration, but Cu has toxic effects on tissues and organs at high concentration. Endoplasmic reticulum (ER) is a toxicological target in Cu poison. Thus far, no studies have focused on the relationship among copper, endoplasmic reticulum (ER) stress and apoptosis in animal and human livers. In the present study, mice treated with copper sulfate (CuSO4) were used to assess the impacts of copper on ER stress and hepatic apoptosis. A total of 240 mice were orally administered with 0 (control), 10, 20 and 40 mg/kg of CuSO4 for 42 days. The results indicated that CuSO4 at 10 mg/kg markedly induced hepatocyte apoptosis and ER stress. In addition, ER stress was characterized by the increased mRNA and protein levels of glucose-regulated protein 78 (GRP78) and 94 (GRP94). Furthermore, ER stress-triggered 3 apoptotic pathways were also activated by the increased intracellular calcium and up-regulated expression levels of genes involved in growth arrest- and DNA damage-inducible gene 153 (Gadd153/CHOP), c-Jun N-terminal kinase (JNK) and cysteine aspartate-specific protease 12 (caspase-12) signaling pathways in CuSO4-treated mice. In conclusion, CuSO4-induced ER stress can promote hepatic apoptosis in mice by activating CHOP, JNK and caspase-12 signaling pathways.

Medical career expectations of academically talented high school students: a nationwide cross-sectional study in China.

BACKGROUND: Academically talented high school students (ATHSSs), an exceptional cohort, are not well studied for their career expectations, especially for those with medical career expectation (MCE). Nowadays, the public perception of the medical profession is changing in China. The purpose of this study was to answer questions about 'is medicine attractive for ATHSSs and 'what factors affect medical career expectations (MCE) for ATHSSs' in China. METHODS: A total of 16,479 representative ATHSSs in senior three completed a questionnaire and four different academic tests. Frequency statistics showed the proportion of ATHSSs with MCE. Unpaired t-tests were performed to find out the differences in demographics, family background, and academic performance between students with and without MCE. The logit models analysis were applied to explore the potential factors that affected the MCE of this exceptional group of students. RESULTS: ATHSSs with MCE accounted for 20.6% (ranking 7/18) of the respondents. They were more likely to be female, came from relatively poorer families, lived in a rural area, and performed significantly worse in all academic tests except for mathematics, compared with those without MCE. In addition, the results revealed that gender (ß = - 0.436, p < 0.01), region of hometown (ß = - 103, p < 0.1), mother's years of schooling (ß = - 0.019, p < 0.05), and father's occupational status (ß = - 0.005, p < 0.01) contributed significantly to the MCE of academically talented students. Better performance in mathematics affected the MCE of ATHSSs taking the liberal arts and science tests differently. CONCLUSIONS: We found the medical career is becoming unattractive to academically talented students and the medical career may be losing their aura in China. Students who have medical career expectations are likely to be females and to have a weak family background.

Involvement of H19/miR-326 axis in hepatocellular carcinoma development through modulating TWIST1.

Overexpression of long noncoding RNA (lncRNA) H19 has been observed in various cancers, which indicates that H19 exert important roles in the progression of carcinogenesis. MiR-326 has been reported to play tumor suppressive roles in multiple tumors. Recently, the competing endogenous RNA (ceRNA) hypothesis has implied that lncRNAs might function as molecular sponges for microRNAs in various cancers. However, the roles of H19/miR-326 in human hepatocellular carcinoma (HCC) still remain unclear. The aim of our study was to determine H19/miR-326 expression in HCC cells and investigate their roles in HCC development. We found that H19 was significantly elevated and miR-326 was decreased in HCC cells including Hep3B, HepG2, MHCC-97L, SK-hep1, Hun7, SMCC-7721 compared with LO2 cells, respectively. In the subsequent experiments, we observed that inhibition of H19 can repress HCC cell growth, migration, and invasion in vitro. H19 downregulation can increase miR-326 expression in HCC cells. Meanwhile, miR-326 mimics can also inhibit HCC progression, whereas miR-326 inhibitors exhibited a reverse phenomenon by modulating H19 expression. In addition, a negative association between H19 and miR-326 was predicted and confirmed. Furthermore, the transcription factor TWIST1 has been recognized as a significant regulator in tumor progression. Here, by performing bioinformatics analysis, TWIST1 was identified as a downstream target of miR-326. The findings of our study implied that lncRNA H19 can serve as a ceRNA to sponge miR-326 and modulate TWIST1 levels in HCC pathogenesis. Taken these together, these findings indicated that H19/miR-326/TWIST1 axis was involved in HCC development and can indicate a novel HCC target.

Does academic interest play a more important role in medical sciences than in other disciplines? A nationwide cross-sectional study in China.

BACKGROUND: Research examining the effects of academic interest on students learning achievement across various disciplines, especially a comparison of the effects of academic interest between medical sciences and other disciplines, is still scarce. This study addressed this gap by answering 'does academic interest play a more important role in medical sciences than in other disciplines?'. METHODS: A retrospective cross-sectional study, based on a large project of the National Undergraduate Student Development Survey (NUSDS) conducted by the Ministry of Education of China and Peking University in 2014, was designed to explore the role of academic interest in medical sciences and other disciplines. The participants were resampled to better represent the national distribution of undergraduate students in terms of their demographic characteristics. Specifically, survey data from 54,398 undergraduate students from 87 Chinese universities and colleges were used to address our research questions. We then used the propensity score matching (PSM) model to estimate the effect of academic interest on academic achievement and to compare the effects across different disciplines. RESULTS: Academic interest had a significant positive impact on academic performance, with an effect size of 2.545 (p = 0.000). Specifically, the effect sizes for the disciplines of medical sciences, humanities, social sciences, natural sciences and engineering were 2.310 (p = 0.000), 2.231 (p = 0.000), 2.016 (p = 0.000), 3.840 (p = 0.000) and 2.698 (p = 0.000), respectively. The results show that no particular academic interest in medical sciences is needed to achieve academic success when compared with natural sciences and engineering programmes, but success in medical sciences requires more academic interest than success in humanities or social sciences. CONCLUSIONS: This study clarifies the effect of academic interest on undergraduates' academic achievement while controlling for their demographic characteristics and family factors. The results provide insights into the role of academic interest in academic performance across various disciplines and can inform the college admissions practices of both institutions and high school students in China.

Nickel Carcinogenesis Mechanism: DNA Damage.

Nickel (Ni) is known to be a major carcinogenic heavy metal. Occupational and environmental exposure to Ni has been implicated in human lung and nasal cancers. Currently, the molecular mechanisms of Ni carcinogenicity remain unclear, but studies have shown that Ni-caused DNA damage is an important carcinogenic mechanism. Therefore, we conducted a literature search of DNA damage associated with Ni exposure and summarized known Ni-caused DNA damage effects. In vitro and vivo studies demonstrated that Ni can induce DNA damage through direct DNA binding and reactive oxygen species (ROS) stimulation. Ni can also repress the DNA damage repair systems, including direct reversal, nucleotide repair (NER), base excision repair (BER), mismatch repair (MMR), homologous-recombination repair (HR), and nonhomologous end-joining (NHEJ) repair pathways. The repression of DNA repair is through direct enzyme inhibition and the downregulation of DNA repair molecule expression. Up to now, the exact mechanisms of DNA damage caused by Ni and Ni compounds remain unclear. Revealing the mechanisms of DNA damage from Ni exposure may contribute to the development of preventive strategies in Ni carcinogenicity.

Effects of Spirulina algae as a feed supplement on nutritional value and flavour components of silkie hens eggs.

OBJECTIVE: Silkie chicken (Gallus gallus domesticus brisson) is also named Chinese Taihe chicken, characterized by blue comb, green earlobes, black skin, meat and bones. This study aimed to evaluate the effects of spirulina feeding on the nutritive value and flavour of silkie hens eggs. METHODS: A total of 280 Silkie hens of 42 weeks old were fed 4 different diets, including basal diet and basal diet containing 0.1%, 0.3% and 0.5% spirulina. Each diet group was divided into 70 Silkie hens experimentally. The production performance of silkie hens, the nutritional compositions [e.g., amino acids (AAs) and fatty acids] and flavour substances of silkie hens eggs were compared with control. RESULTS: A 0.3% and 0.5% spirulina feeding significantly increased the average egg production rate and average egg weight, while only 0.3% spirulina feeding decreased both the average daily feed intake and feed conversion ratio of silkie hens compared with the controls (p < 0.05). The contents of crude protein, fat, cholesterol and Ca in silkie hens eggs were significantly increased by 0.3% spirulina feeding (p < 0.05). Only fat and cholesterol were significantly increased by 0.5% spirulina but had no significant difference compared with 0.3% spirulina. The flavour, amino acids/total AAs, and saturated fatty acids/unsaturated fatty acids in silkie hens eggs were significantly increased by 0.3% spirulina feeding than other groups (p < 0.05). A total of 46 volatile substances were identified in silkie hens eggs, and the substances of total acids, alkanes and aldehydes were significantly increased by 0.3% spirulina feeding. CONCLUSION: Spirulina feeding at a proportion of 0.3% improved the production performance of silkie hens, and nutritive value and flavour of silkie hens eggs.

miR-140-5p-mediated regulation of the proliferation and differentiation of human dental pulp stem cells occurs through the lipopolysaccharide/toll-like receptor 4 signaling pathway.

Human dental pulp stem cells (DPSCs) are oral mesenchymal stem cells with potential to differentiate into various cell types. Recent studies of DPSCs have focused on microRNAs (miRNAs), a class of small noncoding RNAs that play crucial roles in regulating DPSC phenotypes. In the current study, the expression of miR-140-5p was significantly decreased during lipopolysaccharide (LPS)-mediated differentiation of DPSCs in vitro. Overexpression of miR-140-5p enhanced proliferation of DPSCs and inhibited DPSC differentiation, whereas suppression of miR-140-5p produced the opposite effect. Moreover, the expression of toll-like receptor 4 (TLR-4), a critical regulator of DPSCs, was negatively correlated with the levels of miR-140-5p. A luciferase reporter analysis confirmed that miR-140-5p could regulate TLR-4 by directly binding to the 3'-untranslated region (3'-UTR) of the TLR4 mRNA. Additionally, we suppressed TLR-4 expression by treating cells with a TLR-4 inhibitor, CLI-095, and demonstrated that the effect of the miR-140-5p inhibitor on DPSC proliferation and differentiation could be partially reversed by blocking TLR-4. Taken together, our data suggest that miR-140-5p is a novel miRNA that regulates DPSC proliferation and differentiation.