Search

Using non-equilibrium molecular simulations, we systematically elaborate the relationships among synthesis (membrane's thickness and morphology), atomic-scale transport mechanism, and separation performance (permeability and selectivity) for 3D-printed polyamide (PA) membranes. Results indicated that water diffusion, swelling ratio, water flux, and water permeance proportionally decrease with increasing membrane thickness (4.0–32.5 nm). PA membranes with different thicknesses can achieve almost 100% salt rejection over the simulation time. Importantly, water permeability exponentially decreases with increasing thickness, and 15 nm is identified as the critical membrane thickness for efficient water transport. The discontinuous water-available space spreads all over PA membranes with thicknesses greater than 5 nm, allowing water molecules to jump by way of the temporary open-and-close pores. However, the connected water-useable space exists in PA membranes with thicknesses below 5 nm, offering the continuous channels to dominate water transport. More significantly, pore distribution is more homogeneous as the thickness increases. The applied high pressures can lead to membrane compaction during reverse osmosis and the thicker membranes show a lower compression ratio. In short, these investigations provide molecular insights for effectively designing and manufacturing PA membranes for water desalination and treatment at the molecular level.

Background Effects of parental marital status on nonsuicidal self-injury (NSSI) behaviors and negative emotions in adolescents have been rarely reported, and the existing research sample size is relatively small. Objective To explore the association of parental marital status with negative emotions and NSSI in middle school students, to provide a reference for the prevention and control of NSSI in them. Methods A stratified random sampling method was used to conduct the questionnaire survey on students from 20 townships and 67 middle schools in Nanchong City and its surrounding areas from March to April 2020. The investigators input the questionnaire into the WJX.cn to generate QR codes, which were distributed to parents or student guardians by schools. The questionnaire, consisting of the General Information Questionnaire, Ottawa Self-injury Inventory (OSI) and the Chinese version of the Depression Anxiety Stress Scale-21 (DASS-21), was used to calculate the detection rates of NSSI, depression, anxiety and stress in middle school students to analyze the relevant factors affecting NSSI, depression, anxiety and stress in middle school students. Results A total of 8 785 students from 23 middle schools were surveyed, and 8 606 valid questionnaires were finally obtained, with a valid recovery rate of 98.0%. Among the 8 606 middle school students, there were 4 540 (52.8%) males, 4 066 (47.2%) females; 5 937 (69.0%) junior high school students, 1 028 (11.9%) senior high school students and 1 641 (19.1%) vocational high school students; 7 274 (84.5%) students in two-parent families, 787 (9.1%) students in divorced single-parent families, and 545 (6.4%) students in families with divorced and remarried parents. The detection rates of NSSI, depression, anxiety and stress in middle school students were 5.6% (486/8 606), 21.9% (1 884/8 606), 26.8% (2 305/8 606) and 12.3% (1 060/8 606), respectively. The results of multivariate Logistic regression analysis showed that among all middle school students, compared with boys, girls had a higher risk of NSSI (OR=2.363, 95%CI=1.946-2.868) and anxiety (OR=1.195, 95%CI=1.086-1.315) ; compared with junior high school students, vocational high school students had a higher risk of NSSI (OR=1.847, 95%CI=1.494-2.284), depression (OR=1.886, 95%CI=1.667-2.134), anxiety (OR=1.857, 95%CI=1.141-1.532) and stress (OR=1.527, 95%CI=1.309-1.781) ; compared with middle school students in two-parent family, students in divorced single-parent family had a higher risk of NSSI (OR=2.194, 95%CI=1.669-2.834), depression (OR=1.563, 95%CI=1.326-1.843), anxiety (OR=1.573, 95%CI=1.346-1.839) and stress (OR=1.417, 95%CI=1.153-1.741), students in families with divorced and remarried parents also had a higher risk of NSSI (OR=2.207, 95%CI=1.638-2.975), depression (OR=1.863, 95%CI=1.543-2.249), anxiety (OR=1.796, 95%CI=1.499-2.153) and stress (OR=1.821, 95%CI=1.453-2.282) ; compared to middle school students who are taken care of by their parents for a long time, those who are taken care of by their father alone, mother alone or grandparents alone for a long time had a higher risk of NSSI, depression and anxiety (by father alone: OR=2.045, 95%CI=1.366-3.062; OR=1.633, 95%CI=1.289-2.145; OR=1.373, 95%CI=1.069-1.762; by mother alone: OR=1.772, 95%CI=1.141-2.751; OR=1.435, 95%CI=1.095-1.882; OR=1.513, 95%CI=1.174-1.951; by grandparents alone: OR=2.465, 95%CI=1.918-3.168; OR=1.783, 95%CI=1.513-2.100; OR=1.843, 95%CI=1.577-2.154), students who were taken care of by mother alone or by grandparents alone had a higher risk of stress (OR=1.604, 95%CI=1.166-2.207; OR=1.678, 95%CI=1.375-2.049) (P

Objective To evaluate the safety and efficacy of cold snare polypectomy (CSP) and hot snare polypectomy (HSP) in the treatment of small colorectal polyps. Methods The clinical data of 3 750 patients who underwent endoscopic polypectomy for small colorectal polyps in our hospital from January 1, 2020 to August 31, 2021 were collected and analyzed retrospectively. There were 1 796 cases assigned into CSP group and 1 954 cases into HSP group. Their general data, number and utilization rate of titanium clips, complete resection rate, specimen recovery rate, incidence of delayed bleeding, perforation rate and incidence of abdominal discomfort were analyzed and compared between the 2 groups. Results There were no significant differences in the general data (age, gender, BMI, and number, size, location, morphology and pathological type of polyps) and in proportions of comorbidities (hypertension and diabetes) between the 2 groups (P>0.05). The utilization rate and average number of clips used were significantly lower in the CSP group than the HSP group (11.19% vs 19.55%, P < 0.001; 0.16±0.49 vs 0.27±0.63, P < 0.001). No statistical difference was found in the complete resection rate between the 2 groups (93.99% vs 95.04%, P=0.158). The CSP group had higher specimen recovery rate (99.55% vs 98.26%, P < 0.001), lower incidence of delayed bleeding (0.06% vs 0.46%, P=0.037) and incidence of abdominal discomfort (4.18% vs 9.31%, P < 0.001) when compared with the HSP group. In terms of perforation, no occurrence was observed in the CSP group and 1 case (0.05%) in the HSP group, though no statistical difference (P=0.521). Conclusion When compared with HSP, CSP has advantages of lower utilization rate and less number of titanium clips, higher specimen recovery rate, and lower incidence of complications in the treatment of small colorectal polyps. It is a safe and effective treatment, and worthy of clinical application.

ObjectiveTo assess the anxiety and depression symptoms and sleep quality in patients with menstrual migraine， so as to provide references for the prevention and treatment of menstrual migraine and its comorbidity.MethodsAccording to the diagnostic criteria of the International Classification of Headache Disorder， third edition （ICHD-3）， 501 female migraine patients， including 112 patients with menstrual migraine and 389 patients with non-menstrual migraine， who attended the outpatient clinic of the Affiliated Hospital of North Sichuan Medical College from February 2019 to February 2020， were selected for the study. The general and clinical data of the patients were collected， meantime， patients were assessed using Hamilton Anxiety Scale （HAMA）， Hamilton Depression Scale-24 item （HAMD-24）， 6-item Headache Impact Test （HIT-6） and Pittsburgh Sleep Quality Index （PSQI）.ResultsThe detection rates of pure anxiety， pure depression， comorbid anxiety-depression and sleep disorders in patients with menstrual migraine were higher than those in patients with non-menstrual migraine （χ2=4.198， 4.355， 5.236， 8.624， P