Analysis of Cognition, Protection, Psychological, and Job-search Intentions Among Medical and Nonmedical College Students During COVID-19 Epidemic.

Context: Since December 2019, medical practitioners discovered a novel coronavirus causing an acute respiratory-tract infection in some hospitals in Wuhan, Hubei Province. COVID-19 has spread globally, making it an epidemic worldwide at present. Understanding the mental-health responses of college students to COVID-19 can help a school staff to better guide students seeking education. Objective: The study aimed to explore the differences between nonmedical and medical college students during the COVID-19 epidemic in their cognitive interest about the disease, preventive behaviors, psychological effects, and job-search intentions, hoping to provide more targeted measures for virus-coping education for college students. Design: The research team conducted a cross-sectional study, using an anonymous online questionnaire. Setting: The study took place at Shanghai, China. Participants: Participants were 1648 college students studying different specialties in various provinces of China, 485 nonmedical students and 1163 medical students. Outcome Measures: The survey's questions covered the respondents': (1) general demographic characteristics, (2) cognitive interest and knowledge about COVID-19 and its infectiousness as well as efforts at active learning about infectious diseases and viruses, (3) awareness of precautionary behaviors against COVID-19, (4) effects on mental health, and (5) effects on job-search intentions. The research team used descriptive statistics and Chi-square tests to analyze the survey data. Results: Among nonmedical students: (1) 297 participants (61.2%) were interested in learning about COVID-19, (2) 321 participants (66.2%) took the initiative to learn about the virus, (3) 301 participants (62.1%) took the initiative to learn about infectious disease, and (4) 151 participants (31.1%) watched medical-themed movies or TV series about COVID-19. Among medical students, the corresponding proportions were 772 participants (66.4%), 855 participants (73.5%), 791 participants (68.1%), and 791 participants (68.1%), respectively. Among nonmedical students, 223 participants (46.0%) had N95 masks available, 429 participants (88.5%) had disinfectant supplies available, 271 participants (55.9%) wore goggles in public places, 75 participants (15.5%) chose public transportation, and 77 participants (15.9%) were exposed to public places in the week prior to the survey. Among medical students, the corresponding proportions were 470 participants (40.4%), 935 participants (80.4%), 575 participants (49.4%), 243 participants (20.9%), and 297 participants (25.5%), respectively. Furthermore, COVID-19 had a stronger effect on medical students' psychology and job-search ambitions. Conclusions: The news about COVID-19 piqued the interest of medical students. Nonmedical students had stronger protective behavior than medical students. The COVID-19 outbreak had a significant influence on medical students' lives, studies, and moods. In addition, COVID-19 had a greater impact on the job-search intentions of medical students.

Development and Evaluation of a Droplet Digital PCR Assay for 8p23 ß-Defensin Cluster Copy Number Determination.

INTRODUCTION: It has been proposed that the copy number (CN) variation (CNV) in ß-defensin genes (DEFB) on human chromosome 8p23 determines phenotypic differences in inflammatory diseases. However, no method for accurate and easy DEFB CN quantification is yet available. OBJECTIVE: Droplet digital polymerase chain reaction (ddPCR) is a novel method for CNV quantification and has been used for genes such as CCL4L, CCL3L1, AMY1, and HER2. However, to date, no ddPCR assay has been available for DEFB CN determination. In the present study, we aimed to develop and evaluate such a ddPCR assay. METHODS: The assay was designed using DEFB4 and RPP30 as the target and the reference gene, respectively. To evaluate the assay, 283 DNA samples with known CNs previously determined using the multiple ligation-dependent probe amplification (MLPA) method, the current gold standard, were used as standards. To discover the optimal DNA template amount, we tested 80 to 2.5 ng DNA by a serial of one to two dilutions of eight samples. To evaluate the reproducibility of the assay, 31 samples were repeated to calculate the intra- and inter-assay variations. To further validate the reliability of the assay, the CNs of all 283 samples were determined using ddPCR. To compare results with those using quantitative PCR (qPCR), DEFB CNs for 48 samples were determined using qPCR with the same primers and probes. RESULTS: In a one-dimensional plot, the positive and negative droplets were clearly separated in both DEFB4 and RPP30 detection channels. In a two-dimensional plot, four populations of droplets were observed. The 20 ng template DNA proved optimal, with either high (80 ng) or low (10, 5, 2.5 ng) template input leading to ambiguous or inaccurate results. For the 31 standard samples, DEFB CNs were accurately determined with small intra- and inter-assay variations (coefficient of variation < 0.04 for both). In the validation cohort, ddPCR provided the correct CN for all 283 samples with high confidence. qPCR measurements for the 48 samples produced noisy data with high uncertainty and low accuracy. CONCLUSIONS: ddPCR is an accurate, reproducible, easy-to-use, cheap, high-throughput method for DEFB CN determination. ddPCR could be applied to DEFB CN quantification in large-scale case-control studies.