[Characteristics of Phytoplankton Community Structure and Their Relationships with Environmental Factors in Autumn in Qinhe River Basin of Jincheng Region].

In October-November 2020, the phytoplankton and the aquatic environment from 62 sites in the mainstream of the Qinhe River and the largest tributary of the Qinhe River (Danhe River) in the Jincheng region were investigated to clarify the spatial pattern of phytoplankton communities and their driving factors. A total of 7 phyla and 47 species of phytoplankton were identified in the Qinhe River basin and were composed of Cryptophyta, Chlorophyta, Pyrrophyta, Chrysophyta, Bacillariophyta, Cyanophyta, and Crytophyta. Six dominant species in the Qinhe River included:Chlorella vulgaris, Cryptomonas erosa, Chroomonas acuta, Cyclotella stelligera, Chlorococcum, and Euglena viridis. Six dominant species in the Danhe River included:C. erosa, Frustulia vulgaris, E. viridis, C. vulgaris, Trachelomonas oblonga Lemm, and C. stelligera. The Shannon-Wiener diversity index (H') varied from 0.35 to 3.15, with a mean value 1.40. The Pielou evenness index (J) varied from 0.24 to 1.00, with a mean value of 0.68. H' values in the Qinhe River were higher than those in the Danhe River. J values were relatively low in the middle reaches of the Qinhe River and middle-low reaches of the Danhe River. The results in the Qinhe River through a canonical correspondence analysis (CCA) showed that the percent of forest land at a 300 m buffer was the driving factor of Chlorococcum in Chlorophyta, and nitrate, total phosphorus, and the percent of forest land at the 300 m buffer were the driving factors of E. viridis. Cyclotella stelligera was mainly influenced by the percent of urban land and water temperature, whereas C. vulgaris, C. erosa, and C. acuta were mainly influenced by the percent of farmland and residential land at the 300 m buffer. The results in the Danhe River via CCA showed that C. erosa and C. stelligera were mainly influenced by pH and sulfate, E. viridis was mainly influenced by the percent of urban land and grass land, T. oblonga Lemm was mainly influenced by chloride and the percent of forest land, F. vulgaris was mainly influenced by water temperature and the percent of farmland, and C. vulgaris was mainly influenced by ammonia and the percent of farmland.

Impact of coronavirus disease 2019 on the mental health of university students in Sichuan Province, China: An online cross-sectional study.

Coronavirus disease 2019 is an emerging public health problem threatening not only the life but also the normal psychology of people. University students' mental health is the focus in the field of higher education. The coronavirus disease 2019 pandemic has brought into attention the mental health problems of this vulnerable group. The aim of this study was to assess the impact of coronavirus disease 2019 on the mental health of university students in Sichuan Province, China. We conducted a cross-sectional study from April 2020 to May 2020. The participants responded to an online questionnaire that included informed consent, basic information, 20-item Self Reporting Questionnaire (SRQ-20), and Self-Rating Anxiety Scale (SAS). We received 521 effective responses. The results included the following: 19.0% of respondents reported distress, and 31.5%, 8.1%, and 5.8% of them reported mild, moderate, and severe anxiety, respectively; respondents aged ≤ 22 years, medical students, and those who were in general health reported more distress than others; and medical students and those who paid more attention to pandemic information reported more anxiety than others. Findings suggest that the mental health of university students should be monitored during pandemic, especially for younger students, medical students, students in general health status, and those who paid too much attention to the news of the pandemic. Due to the limited sample representativeness, we must be cautious when generalizing these findings to other regions of China or other countries.

Sucrose affecting successful transplantation of vitrified-thawed mouse ovarian tissues.

PURPOSE: The aim of this experiment is to detect effects of varying levels of sucrose on vitrified ovarian tissues. METHODS: Ovarian tissues of mice were vitrified-thawed. Mice were randomly assigned to the fresh control group and experimental groups. According to different concentration of sucrose in vitrification solution, the experimental groups were randomly divided into Group I (0.2 M sucrose), Group II (0.4 M sucrose), Group III (0.8 M sucrose) and Group IV (1.6 M sucrose). Cytology was followed throughout the oophorectomy and transplantation period. Hormone levels and density of follicle were measured 1 month after transplantation. RESULTS: The number of days before the resumption of estrous cycles in control group was significantly smaller than those in all of experimental groups. The serum estradiol levels of mice and the follicular density of ovarian grafts in control group were significantly higher than those in all of experimental groups. In addition, the number of days before the resumption of estrous cycles in Group II and Group III were smaller than those in Group I and Group IV. The serum estradiol levels of mice and the follicular density of ovarian grafts in Group II and Group III were significantly higher than those in Group I and Group IV. However, no difference was observed in the number of days before the resumption of estrous cycles and the serum estradiol levels between Group II and Group III. A similar follicular density was also observed in Group II and Group III. CONCLUSION: Sucrose concentration of 0.4 M or 0.8 M in cryoprotective media is suitable for vitrifying mouse ovarian tissues.

Is caspase inhibition a valid therapeutic strategy in cryopreservation of ovarian tissue?

PURPOSE: The aim of this study is to determine whether inclusion of caspase inhibitor can improve the efficacy of cryopreservation of ovarian tissue. METHODS: Mice were randomly assigned to the Group A (fresh control group) Group B (inclusion of caspase inhibitor) and Group C (non-inclusion of caspase inhibitor). Ovarian tissue in Group B and Group C was vitrified-thawed. TUNEL assay and Bax protein detection were measured after cryopreservation. The mice in all groups received autotransplantation. The number of days before the resumption of estrous cycles was measured daily from the 5th day after surgery, and the percentage of cells expressing PCNA in grafts was measured one month following transplantation. RESULTS: The incidence of TUNEL positive follicles in Group B was significantly higher than that in Group C. Similarly, the percentage of follicles expressing Bax protein in Group B was significantly higher than that in Group C. The number of days before the resumption of estrous cycles in Group B was significantly less than that in Group C. In addition, the percentage of follicular and stromal cells expressing PCNA of grafts in Group B was significantly higher than that in Group C. CONCLUSIONS: The global caspase inhibitor Z-VAD-FMK decreases the incidence of apoptosis of ovarian tissue induced by cryopreservation, and inclusion of caspase inhibitor improves the efficacy of cryopreservation of ovarian tissue.