COVID-19 had become a pandemic raising concerns of widespread panic and increasing anxiety and stress in individuals all over the world (World Health Organization, 2020a). Lots of countries had closed their schools. As the first country to do so, Chinese colleges and universities were making use of different modes of learning, including online-learning based on different platforms to achieve the goal suggested by Ministry of Education in China, "suspending classes without suspending learning," since middle February. This paper is the first one which aims to investigate the anxiety of Chinese university students after the outbreak of COVID-19 right before the start of new spring term. 3611 university students (female: male = 1.48:1) aged between 18 to 24 from all over China were enrolled to this study from a top university in China. The Self-Rating Anxiety Scale -SAS (Zung, 1971) was used to assess anxiety 2 days before the start of new spring term in middle February. All four-year undergraduate students were included in the study. The mean SAS score was 40.53 (SD = 10.15), significantly higher than the national norm (Mean = 29.78, SD = 10.07, and p ≤ .001), and there were still 557 (15.43%, Mean = 58.75, and SD = 8.9) students met the cutoff of 50 and were screened positive. Comparisons among sexes, grades and majors were also conducted. Significant differences were found between all males and all female (p ≤ .001), and between all students majoring arts and sciences in the anxiety sample (n = 557, p = 0.05). The results also showed that the mean SAS scores were not correlated with the regions they came from/lived in. This study concluded that the Chinese university students showed higher anxiety for COVID-19.

Asthenozoospermia (AS) is a common cause of human male infertility. In one study, more than 80% of the samples from infertile men had reduced sperm motility. Seminal plasma is a mixture of secretions from the testis, epididymis and several male accessory glands, including the prostate, seminal vesicles and Cowper's gland. Studies have shown that seminal plasma contains proteins that are important for sperm motility. To further explore the pathophysiological character of AS, we separated the seminal plasma proteins from AS patients and healthy donors using sodium dodecyl sulfate polyacrylamide gel electrophoresis and in-gel digestion, and then subjected the proteins to liquid chromatography-mass spectrometry (LC-MS/MS) analysis. A total of 741 proteins were identified in the seminal plasma, with a false discovery rate of 3.3%. Using spectral counting, we found that 45 proteins were threefold upregulated and 56 proteins were threefold downregulated in the AS group when compared with the control. Most of these proteins originated from the epididymis and prostate. This study identified a rich source of biomarker candidates for male infertility and indicates that functional abnormalities of the epididymis and prostate can contribute to AS. We identified DJ-1-a protein that has been shown elsewhere to be involved in the control of oxidative stress (OS)-as a downregulated protein in AS seminal plasma. The levels of DJ-1 in AS seminal plasma were about half of those in the control samples. In addition, the levels of reactive oxygen species were 3.3-fold higher in the AS samples than in the controls. Taken together, these data suggest that downregulation of DJ-1 is involved in OS in semen, and therefore affects the quality of the semen.

The COVID-19 pandemic has caused tremendous loss starting from early this year. This article aims to investigate the change of anxiety severity and prevalence among non-graduating undergraduate students in the new semester of online learning during COVID-19 in China and also to evaluate a machine learning model based on the XGBoost model. A total of 1172 non-graduating undergraduate students aged between 18 and 22 from 34 provincial-level administrative units and 260 cities in China were enrolled onto this study and asked to fill in a sociodemographic questionnaire and the Self-Rating Anxiety Scale (SAS) twice, respectively, during February 15 to 17, 2020, before the new semester started, and March 15 to 17, 2020, 1 month after the new semester based on online learning had started. SPSS 22.0 was used to conduct t-test and single factor analysis. XGBoost models were implemented to predict the anxiety level of students 1 month after the start of the new semester. There were 184 (15.7%, Mean = 58.45, SD = 7.81) and 221 (18.86%, Mean = 57.68, SD = 7.58) students who met the cut-off of 50 and were screened as positive for anxiety, respectively, in the two investigations. The mean SAS scores in the second test was significantly higher than those in the first test (P < 0.05). Significant differences were also found among all males, females, and students majoring in arts and sciences between the two studies (P < 0.05). The results also showed students from Hubei province, where most cases of COVID-19 were confirmed, had a higher percentage of participants meeting the cut-off of being anxious. This article applied machine learning to establish XGBoost models to successfully predict the anxiety level and changes of anxiety levels 4 weeks later based on the SAS scores of the students in the first test. It was concluded that, during COVID-19, Chinese non-graduating undergraduate students showed higher anxiety in the new semester based on online learning than before the new semester started. More students from Hubei province had a different level of anxiety than other provinces. Families, universities, and society as a whole should pay attention to the psychological health of non-graduating undergraduate students and take measures accordingly. It also confirmed that the XGBoost model had better prediction accuracy compared to the traditional multiple stepwise regression model on the anxiety status of university students.

No abstract

Basal generation of reactive oxygen species (ROS) was essential for male reproductive function, whereas high ROS levels may be linked to low quality of sperm and male infertility. We examined the associations between ROS levels in whole ejaculates and sperm quality among 1092 male factor infertility (MFI) patients and 50 donors with normal semen characteristics. ROS levels were significantly positively correlated with abnormal morphology rate, head defect, and sperm deformity index. Further, we investigated whether seminal plasma from MFI patients with high ROS levels affects sperm motility from donors with normal semen characteristics. After cross-culturing fresh human sperm from donors possessing normal semen characteristics with seminal plasma from infertitle men, sperm motility was measured at different ROS levels. Seminal plasma from MFI patients significantly reduced motility of sperm and the reduction rate increased with increasing ROS levels in seminal plasma. On the other hand, we found MFI patients with the ROS levels in the lowest 25th percentile had similar ROS levels to donors with normal semen characteristics. Collectively, our observations lead to the hypothesis that oxidative stress plays a critical role in the development of MFI among those with high ROS levels, but not those with low ROS levels.