BACKGROUND:As tissue engineering brings new hope to the worldwide problem of articular cartilage repair,the construction of light-curing 3D printed hydrogel scaffolds with biomimetic composition is of great significance for cartilage tissue engineering. OBJECTIVE:To construct a biomimetic methacryloylated hyaluronic acid/acellular Wharton's jelly composite hydrogel scaffold by digital light processing 3D printing technology,and to evaluate its biocompatibility. METHODS:Wharton's jelly was isolated and extracted from human umbilical cord,then decellulated,freeze-dried,ground into powder,and dissolved in PBS to prepare 50 g/L acellular Wharton's jelly solution.Methylallylated hyaluronic acid was prepared,lyophilized and dissolved in PBS to prepare 50 g/L methylallylated hyaluronic acid solution.Acellular Wharton's jelly solution was mixed with methacrylyacylated hyaluronic acid solution at a volume ratio of 1:1,and was used as bio-ink after adding photoinitiator.Methylacrylylated hyaluronic acid hydrogel scaffolds(labeled as HAMA hydrogel scaffolds)and methylacrylylated hyaluronic acid/acellular Wharton's jelly gel scaffolds(labeled as HAMA/WJ hydrogel scaffolds)were prepared by digital light processing 3D printing technology,and the microstructure,swelling performance,biocompatibility,and cartilage differentiation performance of the scaffolds were characterized. RESULTS AND CONCLUSION:(1)Under scanning electron microscope,the two groups of scaffolds showed a three-dimensional network structure,and the fiber connection of HAMA/WJ hydrogel scaffold was more uniform.Both groups achieved swelling equilibrium within 10 hours,and the equilibrium swelling ratio of HAMA/WJ hydrogel scaffold was lower than that of HAMA hydrogel scaffold(P＜0.05).(2)CCK-8 assay showed that HAMA/WJ hydrogel scaffold could promote the proliferation of bone marrow mesenchymal stem cells compared with HAMA hydrogel scaffold.Dead/live staining showed that bone marrow mesenchymal stem cells grew well on the two groups of scaffolds,and the cells on the HAMA/WJ hydrogel scaffolds were evenly distributed and more cells were found.Phalloidine staining showed better adhesion and spread of bone marrow mesenchymal stem cells in HAMA/WJ hydrogel scaffold than in HAMA.(3)Bone marrow mesenchymal stem cells were inoculated into the two groups for chondrogenic induction culture.The results of qRT-PCR showed that the mRNA expressions of agglutinoglycan,SOX9 and type Ⅱ collagen in the HAMA/WJ hydrogel scaffold group were higher than those in the HAMA hydrogel scaffold group(P＜0.05,P＜0.01).(4)These findings indicate that the digital light processing 3D bioprinting HAMA/WJ hydrogel scaffold can promote the proliferation,adhesion,and chondrogenic differentiation of bone marrow mesenchymal stem cells.

Objective: To describe the prevalence and the association of sleep quality trajectory, social jetlag and comorbid symptoms of anxiety and depression among college students, in order to provide a theoretical basis for improving the comorbid symptoms of anxiety and depression in college students. Methods: A questionnaire survey was conducted among 1 135 college students from two universities in Shangrao, Jiangxi Province and Hefei, Anhui Province from April to May 2019, and were followed up once every one year for a total of three times, with a valid sample size of 1 034 individuals after matching with the baseline survey. A selfassessment questionnaire was used to investigate the social jetlag of college students, the Generalized Anxiety Disorder-7 (GAD-7) and Patient Health Questionnaire 9 (PHQ-9) were used to evaluate anxiety and depression symptoms, respectively, while the Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality. College students with GAD-7 score ≥5 and PHQ-9 score ≥5 were defined as having comorbid anxiety and depression symptoms. Latent class growth model (LCGM) was employed to analyze the sleep quality trajectory of college students, and binary Logistic regression was used to analyze the relationship between social jetlag, sleep quality trajectory and comorbid symptoms of anxiety and depression. Results: The detection rate of comorbid symptoms of anxiety and depression among college students was 16.9%, and the detection rate of social jetlag ≥2 h was 13.8%. The sleep quality showed an overall improvement trend, and the two trajectories were good sleep quality (81.6%) and poor sleep quality (18.4%). Binary Logistic regression model showed that poor sleep quality and social jetlag ≥2 h were positively correlated with comorbid symptoms of anxiety and depression (OR=5.94, 1.84, P<0.05). Conclusions Poor sleep quality and social jetlag ≥2 h in college students increase the risk of comorbid symptoms of anxiety and depression. Early screening and intervention of sleep quality and reduction of social jetlag are crucial for enhancing the mental health of college students.

Monkeypox is a zoonotic disease.Previous studies have shown that children are vulnerable to monkeypox and are also at high risk for severe disease or complications.In order to improve pediatricians′ understanding of monkeypox and achieve early detection, early diagnosis, early treatment and early disposal, the committee composed of more than 40 experts in the related fields of infectious diseases, pediatrics, infection control and public health formulate this expert consensus, on the basis of the latest clinical management and infection prevention and control for monkeypox released by the World Health Organization (WHO), the guidelines for diagnosis and treatment of monkeypox (version 2022) issued by National Health Commission of the People′s Republic of China and other relevant documents.During the development of this consensus, multidisciplinary experts have repeatedly demonstrated the etiology, epidemiology, transmission, clinical manifestations, laboratory examinations, diagnosis and differential diagnosis, treatment, discharge criteria, prevention, case management process and key points of prevention and control about monkeypox.

Group A Streptococcus (GAS) is a very important pathogen, especially for children.On a global scale, GAS is an important cause of morbidity and mortality.But the burden of disease caused by GAS is still unknown in China and also has not obtained enough attention.For this purpose, the expert consensus is comprehensively described in diagnosis, treatment and prevention of GAS diseases in children, covering related aspects of pneumology, infectiology, immunology, microbiology, cardiology, nephrology, critical care medicine and preventive medicine.Accordingly, the consensus document was intended to improve management strategies of GAS disease in Chinese children.

In all the carpal fractures, scaphoid fracture is the most common in clinic (from 60% to 70% in proportion) and likely leads to nonunion. If nonunion is not treated in time, it probably causes instability of the scaphoid lunate joint, further leading to scapholunate advanced collapse. Its comprehensive manifestations include degenerative arthropathy of radial styloid process, radial scaphoid joint, capitulolunate joint and even total wrist joint, eventually leading to wrist joint dysfunction. Therefore, more and more attention has been paid to treatments of scaphoid fracture nonunion. Bone grafting is the most common practical treatment, but new surgical procedures have emerged in recent years. This article thus reviews the research advances in bone grafting for scaphoid fracture nonunion, commenting on the advantages and disadvantages of various techniques.

Due to good mechanical properties and biocompatibility, tissue engineering scaffolds have become the vital method for repairing and regenerating articular cartilage defects. With the continuous development of tissue engineering technology, many scaffolds preparation and formation methods have been developed and tested in the past decade, however, the preparation of ideal regenerative scaffolds remain controversial. As load-bearing tissue inside the body joints, the matrix structure and cell composition of articular cartilage are hierarchical, and there are several smooth natural gradients from the cartilage surface to the subchondral bone layer, including cell phenotype and number, specific growth factors, matrix composition, fiber arrangement, mechanical properties, nutrient and oxygen consumption. Therefore, in the design of regenerative scaffolds, it is necessary to achieve these gradients to regenerate articular cartilage in situ. In recent studies, many new biomimetic gradient scaffolds have been used to simulate the natural gradient of articular cartilage. These scaffolds show different mechanical, physicochemical or biological gradients in the structure, and have achieved good repair effects. The related articles on tissue engineering for the treatment of articular cartilage defects were retrieved by searching databases with key wordsarticular cartilage injury, cartilage repair and gradient scaffolds. In this work,the structural, biochemical, biomechanical and nutrient metabolism gradients of natural articular cartilage were studied and summarized firstly. Then, the latest design and construction of articular cartilage gradient scaffolds were classified. Besides that, the material composition (such as hydrogels, nanomaterials, etc.) and the preparation process (such as electrospinning, 3D printing, etc.) of grandient scaffolds were further enhanced. Finally, the prospect and challenge of biomimetic gradient scaffolds in cartilage engineering are discussed, which provides a theoretical basis for the successful application of gradient scaffolds in clinical transformation.

Objective:To observe the effects of Etifoxine on proliferation and migration of RSC96 (Schwann cells of rat) and its potential molecular mechanisms.Methods:From March, 2020 to October, 2020, cultured RSC96 were treated with 20 μmol/L Etifoxine and saline respectively for 48 h. Cell proliferation was tested by EdU assay using Cell-Light EdU DNA Cell Proliferation Kit and the capability of migration was determined by wound healing assay and a transwell system. To investigate the effects of Etifoxine on CELSR2 protein expression, after treated with different concentrations of Etifoxine at 0-20 μmol/L for 48 hours, cells were subject to Western blot analysis to verify the expression of CELSR2 protein. To explore whether CELSR2 would be a potential target of Etifoxine, siRNA targeting CELSR2 and control siRNA groups were transfected into 20 μmol/L Etifoxine-treated RSC96 using Lipo3000. Again, the cell proliferation and migration of were investigated after 48 hours with the same procedures. The two-tailed Mann-Whitney U test was employed in statistical assessment.Results:EdU results showed a significant higher percentage of Edu-positive (proliferating) cells in the 20 μmol/L Etifoxine-treated group than the control group[(36.30±3.09)% vs (19.40±2.50)%, P<0.05]. Transwell migration assay demonstrated that the number of 20 μmol/L Etifoxine-treated RSC96 which migrated through the transwell membrane was higher than saline group, with significant statistical difference [(132.30±6.77) vs(65.33±7.37), P<0.05]. The percentage of reduction of wound area measured at 24 hours and 36 hours after the scratch also showed the similar results [(30.67±2.16)% vs (23.00±2.61)%; (86.00±2.19)% vs (49.67±2.81)%, respectively, P<0.05]. Besides, with increase of the concentration of etifoxine, the expression of CELSR2 showed an trend of increase in RSC96 ( P<0.05), but no significant statistical difference was found between 10 μmol/L and 20 μmol/L groups ( P>0.05). Interestingly, the rate of cell proliferation, the number of migrating cells and the percentage of wound area reduction of RSC96 in which were treated by Etifoxine and transfected with CELSR2 siRNA were significantly decreased compared with the control siRNA treatment ( P<0.05). Conclusion:Etifoxine could promote proliferation and migration of RSC96. Upregulation of CELSR2 protein expression in RSC96 is associated with the Etifoxine-induced enhancement of cell proliferation and migration.

Objective: To describe the prevalence of problematic mobile phone use and anxiety in college students, and explore the mediating effect of sleep quality on the relationship between problematic mobile phone use and anxiety, and to provide reference for physical and mental health promotion of college students. Methods: One medical college and a comprephensive college were selected in Hefei city of Anhui Province and Shangrao City of Jiangxi Province, respectively, and a cross-sectional survey was conducted. A total of 1 135 valid questionnaires were collected. The self-rating questionnaires regarding basic information of college students, use the Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use(SQAPMPU) and the Self-Rating Questionnaire for Depression-Anxiety-Stress for Adolescent Problematic Mobile Phone Use(DASS-21) was used to evaluate problematic mobile phone use and anxiety, respectively. The Pittsburgh Sleep Quality Index(PSQI) was used to evaluate sleep quality. Conclusion: The detection rates of college students with problematic mobile phone use and poor sleep quality were 24.6% and 13.3%, respectively. The detection rates of college students anxiety grouped by severity were 5.1%, 23.9%. Multiple Logistic regression analysis showed a positive linear correlation between problematic mobile phone use and anxiety[OR values(95%CI) were 1.86(1.01-3.44), 4.34(3.14-5.99), P<0.01]. The results of process showed that sleep quality played a moderating role between problematic mobile phone use and anxiety(R2=0.37, F=220.52, P<0.01). Interaction term s β=0.09(P<0.05). Conclusion The prevalence of problematic mobile phone use is high in college students, and problematic mobile phone use is positively related to anxiety. Good sleep quality can alleviate the relationship between mobile phone dependence and anxiety of college students.

The treatment of articular cartilage (AC) injury caused by various reasons is still a major clinical problem. The emergence of cartilage tissue engineering brings new hope for the treatment of AC injury. In general, AC tissue engineering can be divided into two categories, including cell-based tissue engineering and cell-free tissue engineering. Although cell-based tissue engineering can repair cartilage damage to a certain extent, existing therapeutic strategies still suffer from limited cell sources, high costs, risk of disease transmission, and complex procedures. However, the cell-free tissue engineering avoids these shortcomings and brings hope for in-situ AC regeneration. Non-cellular tissue engineering is mainly used to recruit endogenous stem cells/progenitor cells (SCPCs) to reach the site of cartilage injury, and provide a suitable regenerative microenvironment to promote cell proliferation and chondrogenic differentiation, then the maturation of new cartilage tissue was promoted. Therefore, it is also called as cell-homing in situ tissue engineering. Successful recruitment of endogenous SCPCs is the first step in in-situ cartilage tissue engineering. This review aims to introduce chemokine response of cartilage injury, systematically summarize traditional chemoattractant (chemokines and growth factors etc.) and emerging chemoattractant (functional peptides, exosomes and nucleic acid adapters etc.), evaluate the combination mode between chemoattractant and delivery devices, discuss the prospects and challenges of chemoattractant-mediated in situ tissue engineering and provide theoretical basis for the design of endogenous SCPCs homing-based in situ tissue engineering.

Objective: To analyze the genetic characteristics of norovirus(NoV) in Jilin province from 2014 to 2016. Methods: Stool samples from children under 5 years of age with diarrhea were collected from Changchun Children′s Hospital. Samples were amplified by RT-PCR. The polymerase and capsid gene of the positive specimens were amplified.Sequences were analyzed by homologous comparison and phylogenetic analysis. Results: A total of 1 335 samples were detected, 177 were positive for NoV, and positive rate was 13.26%. The positive rate was 11.83% in 2014, 12.53% in 2015 and 15.75% in 2016. Genotyping of polymerase region revealed GII.P12 types dominated in 2014 and GII.Pe types dominated in 2015 and 2016. Genotyping of polymerase region revealed that GII.3 types dominated in 2014 and GII.4_Sydney2012 types dominated in 2015 and 2016. The types of both regions included GII.P17/GII.17, GII.Pe/GII.4_Sydney2012, GII.P12/GII.3, GII.Pe/GII.3、GII.P16/GII.2 and GII.P7/GII.6. Conclusions Genotypes of NoV infection are diverse in Jilin province. Most of them are recombinant strains. The main epidemic strains changed from GII.P12/GII.3 in 2014 to GII.Pe/GII.4_Sydney2012 in 2015 and 2016.