Good learning environment of medical schools is an independent predictor for medical students’ study engagement

BackgroundStudy engagement is regarded important to medical students’ physical and mental wellbeing. However, the relationship between learning environment of medical schools and the study engagement of medical students was still unclear. This study was aimed to ascertain the positive effect of learning environment in study engagement.MethodsWe collected 10,901 valid questionnaires from 12 medical universities in China, and UWES-S was utilized to assess the study engagement levels. Then Pearson Chi-Square test and Welch’s ANOVA test were conducted to find the relationship between study engagement and learning environment, and subgroup analysis was used to eradicate possible influence of confounding factors. After that, a multivariate analysis was performed to prove learning environment was an independent factor, and we constructed a nomogram as a predictive model.ResultsWith Pearson Chi-Square test (p < 0.001) and Welch’s ANOVA test (p < 0.001), it proved that a good learning environment contributed to a higher mean of UWES scores. Subgroup analysis also showed statistical significance (p < 0.001). In the multivariate analysis, we could find that, taking “Good” as reference, “Excellent” (OR = 0.329, 95%CI = 0.295–0.366, p < 0.001) learning environment was conducive to one’s study engagement, while “Common” (OR = 2.206, 95%CI = 1.989–2.446, p < 0.001), “Bad” (OR = 2.349, 95%CI = 1.597–3.454, p < 0.001), and “Terrible” (OR = 1.696, 95%CI = 1.015–2.834, p = 0.044) learning environment only resulted into relatively bad study engagement. Depending on the result, a nomogram was drawn, which had predictive discrimination and accuracy (AUC = 0.680).ConclusionWe concluded that learning environment of school was an independent factor of medical student’s study engagement. A higher level of learning environment of medical school came with a higher level of medical students’ study engagement. The nomogram could serve as a predictive reference for the educators and researchers

Study on the Structure of a Mixed KCl and K2SO4 Aqueous Solution Using a Modified X-ray Scattering Device, Raman Spectroscopy, and Molecular Dynamics Simulation

The microstructure of a mixed KCl and K2SO4 aqueous solution was studied using X-ray scattering (XRS), Raman spectroscopy, and molecular dynamics simulation (MD). Reduced structure functions [F(Q)], reduced pair distribution functions [G(r)], Raman spectrum, and pair distribution functions (PDF) were obtained. The XRS results show that the main peak (r = 2.81 Å) of G(r) shifted to the right of the axis (r = 3.15 Å) with increased KCl and decreased K2SO4. The main peak was at r = 3.15 Å when the KCl concentration was 26.00% and the K2SO4 concentration was 0.00%. It is speculated that this phenomenon was caused by the main interaction changing, from K-OW (r = 2.80 Å) and OW-OW (r = 2.80 Å), to Cl−-OW (r = 3.14 Å) and K+-Cl− (r = 3.15 Å). According to the trend of the hydrogen bond structure in the Raman spectrum, when the concentration of KCl was high and K2SO4 was low, the destruction of the tetrahedral hydrogen bond network in the solution was more serious. This shows that the destruction strength of the anion to the hydrogen bond network structure in solution was Cl− > SO42−. In the MD simulations, the coordination number of OW-OW decreased with increasing KCl concentration, indicating that the tetrahedral hydrogen bond network was severely disrupted, which confirmed the results of the Raman spectroscopy. The hydration radius and coordination number of SO42− in the mixed solution were larger than Cl−, thus revealing the reason why the solubility of KCl in water was greater than that of K2SO4 at room temperature

BM formation detected by immunohistochemistry.

<p>(A–C) Collagen IV and (D–F) laminin distribute intermittently at the epidermis-ADM junction of the wound 2 weeks after co-transplantation (arrows in A and D), and by week 4 their distributions have become continuous (arrows in B and E), similar to that in normal skin (arrows in C and F). Scale bars = 100 µm.</p

Tissue viability analysis.

<p>(A) Viability index of the epidermal sheet determined by CCK-8 assay. There is no significant difference in the viability index between the 8- and 10-h digestion groups, while the value of the 12-h digestion group is significantly lower than that of the 8-h digestion group. n = 5. (B) The percentage of viable cells detected by Hoe/PI staining. With the duration of Dispase II digestion prolonging, the percentage of viable cells in the epidermal sheet decreases gradually. n = 5.</p

Histological characterization of epidermal sheet.

<p>(A) Gross appearance of the split-thickness skin. (B) Gross appearance of the epidermal sheet. It appears milk white, soft and elastic, and can be lifted and stretched by forceps. (C) H&E staining of the split-thickness skin. It is composed of an epidermis (solid arrows) and an underlying partial dermis, including some sebaceous glands (dotted arrow) and hair follicles (asterisks). Scale bar = 200 µm. (D) H&E staining of the epidermal sheet. It contains only an intact epidermis. Scale bar = 100 µm. (E–H) Immunohistochemical staining reveals that the split-thickness skin contains continuous distributions of collagen IV (arrows in E) and laminin (arrows in G) at the epidermal-dermal junction, and neither of them is detected in the epidermal sheet (F and H). Dotted lines indicate the location of basal keratinocytes. Scale bars = 100 µm.</p

Wound healing process.

<p>(A) and (B) show gross appearance of the wound 2 and 3 weeks after co-transplantation of the epidermal sheet and ADM, respectively. The epidermal sheet survives and forms a new epidermis (asterisks in A) by week 2. The arrow indicates un-epithelialized area. By week 3, the wound is completely re-epithelialized. The newly generated epidermis becomes apparently thicker, and the healed wound surface is smooth with a mild degree of contraction (dotted lines in B).</p

Surgical procedures of co-transplantation.

<p>The autologous epidermal sheet and ADM are co-transplanted to the full-thickness skin defect.</p

MnO₂‑Functionalized Hydrophobic Ceramic Membrane for Sulfite Oxidation

Catalytic oxidation of sulfite is critical for the fixation of sulfite in the flue gas desulfurization process and is also an essential step related to the treatment of air and water pollution. This work designed and prepared a nano-MnO2-functionalized hydrophobic ceramic membrane with a hydrophobic surface by a hydrothermal method. The chemical composition and the nanostructure of the prepared MnO2 composite membranes were characterized using several identification techniques (X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy). The results show that the prepared nano-MnO2 was sea urchin-like, the crystal form was β-MnO2, and it grows uniformly on the surface of the ceramic membrane. The molar ratios of Mn4+/Mn3+ and Olatt/Ototal were associated with high catalytic activity and enhanced with increasing preparation concentration. The catalytic ability of nano-MnO2 composite membranes to Na2SO3 was studied by the membrane dispersion-catalysis process. The catalytic efficiency with a loaded amount of 1.6–4.5 mg was 5.4–8.3 times higher than that without the catalyst. The free radical quenching experiment showed that SO5•– was identified as the key free radical in the chain reaction. The oxidation kinetics of sulfite were investigated using a membrane dispersion reactor. The results showed that the catalyst, sulfite, and oxygen partial pressure reaction orders were 0.411, 0.243, and 0.640, respectively, and showed an apparent activation energy of 1.89 kJ·mol–1. Based on the three-phase reaction model analysis, sulfite oxidation was considered to be controlled by the mass transfer process of oxygen from the gas phase to the liquid phase

Histological analysis of the wound.

<p>(A) H&E staining of the wound 3 weeks after co-transplantation. The newly formed epidermis lies directly on the ADM surface. Scale bar = 200 µm. (B) H&E staining of the ADM 3 weeks after subcutaneous implantation. The ADM is laid between the host dermis and deep fascia. Scale bar = 500 µm. (C–D) H&E staining of the ADM-fascia junction area in the co-transplantation and subcutaneous implantation groups, respectively, indicating no apparent inflammatory response around the ADM, and fibroblasts and new blood vessels (arrows) have infiltrated into the ADM. Scale bars = 100 µm. (E–F) Masson’s trichrome staining of the ADM 3 weeks after co-transplantation (E) and subcutaneous implantation (F) show the broad presence of neo-capillaries (arrows) in both groups. Scale bars = 50 µm.</p