Learning motivation is a significant factor that ensures quality in medical education, and might affect the academic performance and well-being of medical students. This study aimed to explore the ...status of achievement goal orientations among medical students in China and to further identify the association among academic performance, academic well-being, and achievement goal orientations. Data were collected through a cross-sectional, anonymous survey conducted with 3,511 respondents (effective response rate = 81.7%), from four medical universities in China, and demographic factors, achievement goal orientations, academic performance, and academic well-being were assessed. The average score of achievement goal orientations of Chinese medical students suggested a difference in demographic factors, including sex, year of study, experience of leadership cadre, and family income. Both mastery and performance-avoidance goals were associated with academic performance, subjective academic stress, subjective learning adaptability, subjective sleep quality, and subjective well-being. Performance-approach goals were related to academic performance, subjective academic stress, and subjective learning adaptability. The achievement goal orientations of the medical students in this study were at a middle level. The findings emphasize the importance of mastery goals for promoting the academic performance and well-being of medical students. More care and attention toward achievement goal orientations can be beneficial for the improvement of the academic performance and well-being among medical students.
Background
Juvenile idiopathic arthritis (JIA) is the most common rheumatic disease in childhood driven by aberrant pathways of T-cell activation. T helper 17 (Th17)/regulatory T cell (Treg) ...imbalance plays critical roles in the pathogenesis of arthritis. MicroRNA-125b (miR-125b) was upregulated after the activation of the initial CD4
+
T cells, and could regulate the differentiation of CD4
+
T cells. However, the effects of miR-125b on Th17/Treg imbalance and differentiation of Th17/Treg cells remain unknown.
Methods
In this study, we evaluated the expression of miR-125b in the peripheral blood mononuclear cells (PBMCs) of children with JIA, and the relationship of miR-125b with Th17/Treg imbalance. Then, we used lentivirus vector-mediated overexpression technology to investigate the regulatory function of miR-125b in CD4
+
T cells or dendritic cell/CD4
+
T co-culture system.
Results
Decreased miR-125b expression in PBMCs and CD4
+
T cells of JIA patients was negatively correlated with the ratio of Th17/Treg cells. It also correlated negatively with retinoic acid receptor-related orphan receptor γt but positively with Forkhead box protein 3 at transcriptional levels. Furthermore, we found that miR-125b overexpression inhibited Th17 cell differentiation, whereas facilitated the differentiation of Treg cells. MiR-125b upregulation led to the decrease of Th17-secreting cytokines but the increase of the Treg-secreting cytokines.
Conclusions
Our results demonstrate that miR-125b participated in regulating Th17/Treg cell differentiation and imbalance in JIA patients. These findings provide novel insight into the critical role of miR-125b in the Th17/Treg imbalance of JIA, and raise the distinct possibility that miR-125b may prove to be a potential therapeutic target for JIA.
The high concentration of Fe3+ ions present in ammonium phosphate solutions have a significant effect on product quality and product morphology. Herein, hybrid adsorbents fluor(calcium ...silicate)/activated carbon (FCS/AC) combined with fluor(calcium silicate) (FCS) and activated carbon (AC) were prepared, characterized, and applied in the removal of Fe3+ ions from ammonium phosphate solutions. FCS/AC held both advantages of FCS and AC indicating a significant adsorption for Fe3+ ions. The adsorption kinetics, isotherms and thermodynamics of Fe3+ onto FCS/AC were investigated. The effect of solution pH, initial Fe3+ concentration, temperature and contact time on the adsorption of Fe3+ onto FCS/AC were also investigated. Desorption-resorption experiments of FCS/AC for Fe3+ ions were examined by the batch method using different eluents. The results showed that FCS/AC was an excellent, low cost and reusable adsorbent for the removal of Fe3+ ions from ammonium phosphate solutions, and the adsorption process appeared to follow the pseudo-second-order kinetic model and Langmuir isotherm model with a maximum Fe3+ adsorption of 15.41 mg/g. Various thermodynamic parameters such as △G0, △H0 and △S0 were calculated indicating the feasibility of the process and spontaneous nature of the adsorption.
A series of laboratory experiments were conducted to investigate the damping effect of net cages in waves. The wave transmission coefficient of the net cage was investigated with different wave ...periods, wave heights, numbers of net cages, net solidities, measurement positions, geometrical shapes of the net cage and Reynolds numbers. The experimental results show that the net cage has noticeable influence on wave propagation and the damping effect of net cages has a close relationship with many parameters. For multiple net cages, the transmission coefficient tends to increase as the wave period increases. The transmission coefficient of net cages decreases with increasing wave height. As the number of net cages increases, the wave transmission coefficient will decrease gradually. The damping effect of net cages on wave propagation tends to increase with increasing net solidity. The measurement position has an effect on the value of wave transmission coefficient. For net cages with different geometrical shapes, the circular net cage has more noticeable damping effect than the square net cage. A numerical model is introduced to simulate the interaction between waves and net cages with the fishing net treated as the porous media fluid model. The wave transmission coefficient downstream from net cages shows good agreement between experimental and numerical results. The study will contribute to understanding of the damping effect of a large fish farm on wave propagation.
•Experimental and numerical studies on damping effect of net cages in waves are conducted.•Influences of wave and net-cage parameters on wave propagation are analyzed.•This study forms a foundation for studying the wave propagation through a fish farm.
It is known that liver diseases have several characteristics of massive lipid accumulation and lipid metabolic disorder, and are divided into liver inflammation, liver fibrosis, liver cirrhosis (LC), ...and hepatocellular carcinoma (HCC) in patients. Interleukin (IL)-35, a new-discovered cytokine, can protect the liver from the environmental attack by increasing the ratio of Tregs (T regulatory cells) which can increase the anti-inflammatory cytokines and inhibit the proliferation of immune cellular. Interestingly, two opposite mechanisms (pro-inflammatory and anti-inflammatory) have connection with the ultimate formation of liver diseases, which suggest that IL-35 may play crucial function in the process of liver diseases through immunosuppressive regulation. Besides, some obvious advantages also imply that IL-35 can be considered as a new therapeutic target to control the progression of liver diseases, while its mechanism of function still needs further research.
As a common complication of diabetes, the pathogenesis of diabetic peripheral neuropathy (DPN) is closely related to high glucose but has not been clarified. Exosomes can mediate crosstalk between ...Schwann cells (SC) and neurons in the peripheral nerve. Herein, we found that miR-21 in serum exosomes from DPN rats was decreased. SC proliferation was inhibited, cell apoptosis was increased, and the expression of miR-21 in cells and exosomes was downregulated when cultured in high glucose. Increasing miR-21 expression reversed these changes, while knockdown of miR-21 led to the opposite results. When co-cultured with exosomes derived from SC exposed to high glucose, neurite outgrowth was inhibited. On the contrary, neurite outgrowth was accelerated when incubated with exosomes rich in miR-21. We further demonstrated that the SC-derived exosomal miR-21 participates in neurite outgrowth probably through the AKT signaling pathway. Thus, SC-derived exosomal miR-21 contributes to high glucose regulation of neurite outgrowth.
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•The miR-21 was decreased in serum exosomes and sciatic nerve of DPN rats•High glucose inhibited SC viability and downregulated the expression of miR-21•Exosomes derived from SC cultured in high glucose inhibited the neurite outgrowth•SC-derived exosomes rich in miR-21 accelerated the neurite outgrowth of neuron
Biological sciences; Neuroscience; Molecular neuroscience; Diabetology
An unprecedented cyclization reaction of donor–acceptor oxiranes with N,N′-disubstituted thioureas to construct trans-dihydropyrimidines is presented. Preliminary reaction mechanism studies ...demonstrated that the reaction underwent sequential cycloaddition/amine ester exchange/oxygen–sulfur exchange/desulfuration/Michael addition process. A wide range of trans-dihydropyrimidines were produced with high yields up to 94% by using this method.
Fomitopsis pinicola (Sw. Ex Fr.) Krast has been commonly used as a health food source and antitumor agent. To uncover bioactive key composition of F. pinicola, in our study, we investigated the ...chemical constituents of a methanol extract of F. pinicola and thirty-five lanostane-type tritetpenoids; 13 new compounds (1–13) and twenty-two known analogues (14–35) were isolated. Among them, compounds 1–9 were C30 lanostane triterpenoids and triterpene sugar esters, while compounds 10–13 were C31 triterpenoids and triterpene sugar esters. Their structures and absolute configurations were elucidated by extensive 1D, 2D NMR, MS, and IR spectra. Furthermore, cytotoxic activities of all isolates against five human tumor cell lines (HL-60, A549, SMMC-7721, MCF-7, and SW480) were evaluated. The results showed that compounds 12, 14, 17, 18, 22, and 23 displayed cytotoxic effects against five human tumor cell lines with IC50 values ranging from 3.92–28.51 μM. Meanwhile, compounds 9 and 35 exhibited selected inhibitory activities against HL-60, SMMC-7721, and MCF-7 with IC50 values in the range of 13.57–36.01 μM. Furthermore, the flow cytometry analysis revealed that compounds 17, 22, and 35 induced apoptosis in HL-60 cell lines. Their structure–activity relationships were preliminarily reported. These findings indicate the vital role of triterpenoids and their glycosides in explaining antitumor effects of F. pinicola and provide important evidence for further development and utilization of this fungus.
Coal is a complex geological body that is composed of organic material, gas, and water. Generally, coal with high hardness is commonly considered to be a non-outburst risk; however, several coal ...mines with hard coal seams in China have experienced coal and gas outbursts. Coals with different degrees of metamorphism have different inherent moisture ranges, which has a strong influence on gas adsorption and desorption. Currently, inhomogeneous moisture wetting remains an issue in traditional preparation methods for preparing coal samples with different moisture levels. In this paper, we chose three typical hard coals with different degrees of metamorphism and systematically studied their pore structure characteristics, effect of approximate inherent moisture on the gas adsorption–desorption characteristics, and gas diffusion of hard coals. The results show that all of the coal samples have an open pore structure, but each coal sample has different development characteristics of their pore structure. The higher the moisture, the shorter the adsorption equilibrium time required and the lower pressure drop. All of the adsorption isotherm curves fit the Langmuir equation well. The gas adsorption capacity of the same coal sample decreases gradually and the amplitude of the gas adsorption capacity decreases with increasing moisture. This relationship indicates that the existence of moisture occupies a certain space of the pore structure and reduces the gas adsorption sites of coal, reducing the adsorption and desorption amount of the coal samples. Moreover, low and middle rank coal can use the bidisperse model to calculate the diffusion coefficient, while high rank coal can use the unipore model. Increasing moisture causes the macropore diffusion coefficient
D
a,e
and micropore diffusion coefficient
D
i,e
of the YZG and YJ samples to decrease. The effective diffusion coefficient
D
e
of the WLH samples also reduced gradually, which suggests that moisture has an influence on the gas migration and diffusion channels of coal, reducing the gas adsorption equilibrium time, desorption rate, and diffusion rate of coal seam.
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