Objective To design and synthesize derivatives of oleanolic acid and ursolic acid, and investigate their anti-hepatitis C virus （HCV） activity along with that of common triterpenoid acids. To explore the structure-activity relationship and provide a reference for the research of anti-HCV drugs derived from natural products through obtaining compounds with higher activity. Methods Oleanolic acid and ursolic acid were directly reacted with corresponding amines using PyBOP as a condensing agent in the presence of DIEA. Alternatively, the target compounds were prepared through PCC oxidation followed by the Baeyer-Villiger reaction catalyzed by m-CPBA. In vitro anti-HCV activity was tested using the HCVcc infection model. Molecular docking was performed by Autodock software to investigate the interaction between the active compounds and HCV NS5B. Results Oleanolic acid, glycyrrhetinic acid, ursolic acid, and asiatic acid all exhibited certain anti-HCV effects. Specifically, oleanolic acid derivatives OA2-OA4, OA6, and OA7, as well as ursolic acid derivatives UA1 and UA2, demonstrated superior anti-HCV activity compared to their parent compounds. Preliminary structure-activity relationship analysis revealed that introducing a bulky group to 28-COOH of oleanolic acid and ursolic acid enhanced their activity. Molecular docking results demonstrated that the active compounds could stably bind to HCV NS5B, thereby exhibiting antiviral activity. Conclusion Pentacyclic triterpenoids possessed anti-HCV effects, and their derivatives coud be synthesized to obtain more active compounds. The anti-HCV mechanism of these compounds may be associated with their inhibition of NS5B.

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Protein polypeptides are a class of bioactive substances that play a crucial role in maintaining the stability of various functions of the organism.Rapid and accurate detection of their levels could help in the diagnosis of diseases,the monitoring of drug therapy and the research and development of medicines,which is of great significance in the fields of clinical medicine,biology and pharmacy.Conventional protein polypeptides detection methods,such as Western blotting and enzyme-linked immunosorbent assay,still have problems like low sensitivity or difficulty in determining more than 1 analyte simultaneously.Liquid chromatography-mass spectrometry(LC-MS)has the advantages of specificity,sensitivity and high throughput.However,low ionization efficiency of macromolecules and strong biological matrix effects limit the feasibility of direct detection of protein polypeptides by LC-MS,which has led to the development of signal conversion and amplification strategies based on LC-MS technology.In this review,we summarized the research progress of sample pretreatment methods and signal conversion and amplification strategies for quantification of protein polypeptides in vivo based on LC-MS in recent years,providing a reference for developing specific high-sensitivity detection methods for low-abundance protein polypeptides in complex samples based on LC-MS technology.

Myocarditis has diverse clinical manifestations,which might develop into acute heart failure,cardiogenic shock and chronic dilated cardiomyopathy.Early diagnosis of myocarditis is crucial for improving prognosis.Cardiac MRI(CMRI)can display myocardial necrosis,fibrosis and edema,having become the best imaging method for evaluating myocarditis.The progresses in multi-parameter CMRI researches of acute myocarditis were reviewed in this article.

Purpose: This study investigated whether professional identity predicts learning burnout among Chinese nursing students, and whether resilience moderates this relationship. Methods: This cross-sectional study recruited 635 students from a nursing college at a medical university in Hefei, China. Data were collected using the professional identity questionnaire, learning burnout scale for college students, and 10-item Connor-Davidson Resilience Scale. Pearson’s correlation analysis was used to investigate the relationships between variables. The mediation effect was evaluated using linear regression and the bootstrap method in SPSS. Results: Nursing students exhibited intermediate learning burnout levels (score: 54.95 ± 10.42). Professional identity was positively correlated with psychological resilience (r = .42, p < .001), whereas learning burnout was negatively correlated with professional identity (r = - .54, p < .001) and psychological resilience (r = -.57, p < .001). Psychological resilience mediated the relationship between professional identity and learning burntout to the tune of 32.8%. Conclusion Psychological resilience mediates the relationship between professional identity and learning burnout. Thus, nursing educators can mitigate student burnout by developing their students' professional identities and psychological resilience.

Purpose: This study investigated whether professional identity predicts learning burnout among Chinese nursing students, and whether resilience moderates this relationship. Methods: This cross-sectional study recruited 635 students from a nursing college at a medical university in Hefei, China. Data were collected using the professional identity questionnaire, learning burnout scale for college students, and 10-item Connor-Davidson Resilience Scale. Pearson’s correlation analysis was used to investigate the relationships between variables. The mediation effect was evaluated using linear regression and the bootstrap method in SPSS. Results: Nursing students exhibited intermediate learning burnout levels (score: 54.95 ± 10.42). Professional identity was positively correlated with psychological resilience (r = .42, p < .001), whereas learning burnout was negatively correlated with professional identity (r = - .54, p < .001) and psychological resilience (r = -.57, p < .001). Psychological resilience mediated the relationship between professional identity and learning burntout to the tune of 32.8%. Conclusion Psychological resilience mediates the relationship between professional identity and learning burnout. Thus, nursing educators can mitigate student burnout by developing their students' professional identities and psychological resilience.

Purpose: This study investigated whether professional identity predicts learning burnout among Chinese nursing students, and whether resilience moderates this relationship. Methods: This cross-sectional study recruited 635 students from a nursing college at a medical university in Hefei, China. Data were collected using the professional identity questionnaire, learning burnout scale for college students, and 10-item Connor-Davidson Resilience Scale. Pearson’s correlation analysis was used to investigate the relationships between variables. The mediation effect was evaluated using linear regression and the bootstrap method in SPSS. Results: Nursing students exhibited intermediate learning burnout levels (score: 54.95 ± 10.42). Professional identity was positively correlated with psychological resilience (r = .42, p < .001), whereas learning burnout was negatively correlated with professional identity (r = - .54, p < .001) and psychological resilience (r = -.57, p < .001). Psychological resilience mediated the relationship between professional identity and learning burntout to the tune of 32.8%. Conclusion Psychological resilience mediates the relationship between professional identity and learning burnout. Thus, nursing educators can mitigate student burnout by developing their students' professional identities and psychological resilience.

Purpose: This study investigated whether professional identity predicts learning burnout among Chinese nursing students, and whether resilience moderates this relationship. Methods: This cross-sectional study recruited 635 students from a nursing college at a medical university in Hefei, China. Data were collected using the professional identity questionnaire, learning burnout scale for college students, and 10-item Connor-Davidson Resilience Scale. Pearson’s correlation analysis was used to investigate the relationships between variables. The mediation effect was evaluated using linear regression and the bootstrap method in SPSS. Results: Nursing students exhibited intermediate learning burnout levels (score: 54.95 ± 10.42). Professional identity was positively correlated with psychological resilience (r = .42, p < .001), whereas learning burnout was negatively correlated with professional identity (r = - .54, p < .001) and psychological resilience (r = -.57, p < .001). Psychological resilience mediated the relationship between professional identity and learning burntout to the tune of 32.8%. Conclusion Psychological resilience mediates the relationship between professional identity and learning burnout. Thus, nursing educators can mitigate student burnout by developing their students' professional identities and psychological resilience.

ObjectiveTo investigate the changes of intestinal microbiota in type 2 diabetic diarrhea （T2DD） patients with dampness-heat syndrome and spleen-kidney deficiency syndrome. MethodT2DD patients who were admitted to the Department of Endocrinology Ⅰ of the Affiliated Hospital of Shaanxi University of Chinese Medicine from March 2020 to May 2021 were selected， including 14 patients with type 2 diabetes mellitus （T2DM）， 12 T2DD patients with dampness-heat syndrome， and 13 T2DD patients with spleen-kidney deficiency syndrome. Twelve healthy subjects receiving medical examination were selected as control group. Their body mass index （BMI）， fasting plasma glucose （FPG）， 2 h postprandial blood glucose （2 h PBG） and glycosylated hemoglobin （HbA1c） were compared. Fecal samples were collected for DNA extraction to build a database. High-throughput 16S rDNA sequencing was used to compare the composition of intestinal microbiota and the differential bacteria among the four groups. ResultCompared with the conditions in control group， the levels of FPG， 2 h PBG and HbA1c in the other groups were increased （P<0.05）. Alpha diversity showed no significant difference in species richness， evenness and diversity of intestinal microbiota among the groups. Beta diversity indicated that intestinal microbiota tended to be consistent in each group， and there was no marked difference between groups. The top 5 phylum by relative abundance were Bacteroidetes，Proteobacteria， Firmicutes， Actinobacteria， and Fusobacteria， among which，Bacteroidetes， Proteobacteria and Firmicutes were dominant. Compared with the control group， the three diabetic groups had elevated relative abundance of Bacteroidetes while decreased relative abundance of Firmicutes. The relative abundance of Actinomycetes in spleen-kidney deficiency T2DD group was significantly higher than that in the other groups， and the relative abundance of Firmicutes and Fusobacteria in the dampness-heat T2DD group was significantly lower than that in the other groups. At the genus level， the top 10 bacteria by relative abundance were Phocaeicola， Bacteroides， Pseudescherichia， Prevotella， Bifidobacterium， Faecalibacterium， Fusobacterium， Roseburia， Citrobacter， and Cetobacterium. LEfSe analysis revealed that the relative abundance of Prevotella， Mediterraneibacter， Parabacteroides， and Fusicatenibacter in diabetic patients was remarkably higher than that in healthy patients. Bacteroides and Sutterella might be the characteristic microbiota of T2DD patients with dampness-heat syndrome， while Faecalibacterium， Limosilactobacillus， Eubacterium， Gemmiger， Enterocloster， Alistipes， Parasutterella and Oscillibacter might be the characteristic microbiota of T2DD patients with spleen-kidney deficiency syndrome. ConclusionBacteroides and Parasutterella might be the characteristic microbiota of T2DD patients with dampness-heat syndrome and spleen-kidney deficiency syndrome， respectively. This paper provided reference for studying the mechanism， diagnosis and treatment of modern traditional Chinese medicine for T2DD of dampness-heat type and spleen-kidney deficiency type.

Objective:To assess the clinical value of helium-free magnetocardiography(MCG) in the diagnosis of coronary artery disease(CAD).Methods:A total of 213 patients with suspected CAD undergoing MCG in Beijing Anzhen Hospital were enrolled in the study. All patients underwent coronary CT angiography/invasive coronary angiography(CCTA/ICA) within 48 hours after MCG scanning. The parameters of MCG, including magnetic field multipolarization, magnetic field unipolarization, T-wave flattened, change in magnetic field distribution at TT segment, abnormal T-peak amplitude ration of maximum to minimum, significant movement of poles, magnetic field angle deviation and abnormal distribution of positive pole were used for the evaluation of the stenosis of coronary arteries.Results:Among 213 patients, MCG scanning was completed in 193 cases(90.6%), while 20 cases were excluded for various reasons. The CCTA/ICA results were taken as gold standard, the total coincidence rate of MCG with the degree of stenosis was 88.60%(95% CI: 83.25%-92.72%), the sensitivity and specificity of MCG in the diagnosis of CAD was 89.63%(95% CI: 83.21%-94.21%) and 88.23%(95% CI:78.12%-94.78%), respectively; the positive and negative predictive value were 93.80%(95% CI:88.72%-96.68%) and 81.08%(95% CI:72.15%-87.64%), respectively. Conclusion:MCG is highly accurate in the diagnosis of CAD, it may be widely used clinically as an non-invasive method free of radiation or contrast agent.