Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

ObjectiveTo explore the effect of respiratory training based on core stabilization training on lumbar disc herniation. MethodsFrom January, 2023 to October, 2024, 96 patients with lumbar disc herniation admitted to the First Affiliated Hospital of Bengbu Medical University were divided into control group (n = 32), core group (n = 32) and respiratory group (n = 32). All the groups underwent conventional rehabilitation therapy, with core stabilization training in the core group and respiratory training combined with core stabilization training in the respiratory group, additionally, for four weeks. Before and after training, the scores of Visual Analogue Scale, Japanese Orthopaedic Association (JOA) and Oswestry Dysfunction Index (ODI) were compared, the average electromyographic value (AEMG) and root mean square (RMS) value of the multifidus and transversus abdominis were detected by surface electromyography (sEMG); and the thickness of the multifidus and transversus abdominis were measured by musculoskeletal ultrasonography bilaterally. ResultsThe intra-group effect (F > 597.796, P < 0.001), inter-group effect (F > 16.535, P < 0.001) and interaction effect (F > 49.622, P < 0.001) were significant in the scores of VAS, JOA and ODI; which were better in the respiratory group than in the control group and the core group (P < 0.05), and were better in the core group than in the control group (P < 0.001). The intra-group effect (F > 7971.631, P < 0.001), inter-group effect (F > 177.760, P < 0.001) and interaction effect (F > 478.771, P < 0.001) were significant in the thickness of the transversus abdominis and multifidus; which were better in the respiratory group than in the control group and the core group (P < 0.001), and were better in the core group than in the control group (P < 0.001). The intra-group effect (F > 144303.007, P < 0.001), inter-group effect (F > 1495.458, P < 0.001) and interaction effect (F > 3121.361, P < 0.001) were significant in the RMS of the multifidus and transversus abdominis; which were better in the respiratory group than in the control group and the core group (P < 0.001), and were better in the core group than in the control group (P < 0.001). The intra-group effect (F > 1890.532, P < 0.001), inter-group effect (F > 607.132, P < 0.001) and interaction effect (F > 824.923, P < 0.001) were significant in the AEMG of the multifidus and transversus abdominis; which were better in the respiratory group than in the control group and core group (P < 0.001), and were better in the core group than in the control group (P < 0.001). ConclusionCore training combined with respiratory training can more effectively reduce pain and improve dysfunction by enhancing the strength and control of the core muscles， thus improving the quality of life of patients with lumbar disc herniation.

ObjectiveTo investigate the influencing factors for recompensation in patients with decompensated hepatitis C cirrhosis， and to establish a predictive model. MethodsA total of 217 patients who were diagnosed with decompensated hepatitis C cirrhosis and were admitted to The Third People’s Hospital of Kunming l from January， 2019 to December， 2022 were enrolled， among whom 63 patients who were readmitted within at least 1 year and had no portal hypertension-related complications were enrolled as recompensation group， and 154 patients without recompensation were enrolled as control group. Related clinical data were collected， and univariate and multivariate analyses were performed for the factors that may affect the occurrence of recompensation. The independent-samples t test was used for comparison of normally distributed measurement data between two groups， and the Mann-Whitney U test was used for comparison of non-normally distributed measurement data between two groups； the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. A binary Logistic regression analysis was used to investigate the influencing factors for recompensation in patients with decompensated hepatitis C cirrhosis， and the receiver operating characteristic （ROC） curve was used to assess the predictive performance of the model. ResultsAmong the 217 patients with decompensated hepatitis C cirrhosis， 63 （29.03%） had recompensation. There were significant differences between the recompensation group and the control group in HIV history （χ²=4.566， P=0.034）， history of partial splenic embolism （χ²=6.687， P=0.014）， Child-Pugh classification （χ²=11.978， P=0.003）， grade of ascites （χ²=14.229， P<0.001）， albumin （t=4.063， P<0.001）， prealbumin （Z=-3.077， P=0.002）， high-density lipoprotein （t=2.854， P=0.011）， high-sensitivity C-reactive protein （Z=-2.447， P=0.014）， prothrombin time （Z=-2.441， P=0.015）， carcinoembryonic antigen （Z=-2.113， P=0.035）， alpha-fetoprotein （AFP） （Z=-2.063， P=0.039）， CA125 （Z=-2.270， P=0.023）， TT3 （Z=-3.304， P<0.001）， TT4 （Z=-2.221， P=0.026）， CD45⁺ （Z=-2.278， P=0.023）， interleukin-5 （Z=-2.845， P=0.004）， tumor necrosis factor-α （Z=-2.176， P=0.030）， and portal vein width （Z=-5.283， P=0.005）. The multivariate analysis showed that history of partial splenic embolism （odds ratio ［OR］=3.064， P=0.049）， HIV history （OR=0.195， P=0.027）， a small amount of ascites （OR=3.390， P=0.017）， AFP （OR=1.003， P=0.004）， and portal vein width （OR=0.600， P<0.001） were independent influencing factors for the occurrence of recompensation in patients with decompensated hepatitis C cirrhosis. The ROC curve analysis showed that HIV history， grade of ascites， history of partial splenic embolism， AFP， portal vein width， and the combined predictive model of these indices had an area under the ROC curve of 0.556， 0.641， 0.560， 0.589， 0.745， and 0.817， respectively. ConclusionFor patients with decompensated hepatitis C cirrhosis， those with a history of partial splenic embolism， a small amount of ascites， and an increase in AFP level are more likely to experience recompensation， while those with a history of HIV and an increase in portal vein width are less likely to experience recompensation.

ObjectiveTo investigate the characteristics of mitochondrial translational initiation factor 2 （MTIF2） gene methylation and its association with the development and progression of hepatocellular carcinoma （HCC）. MethodsMethSurv and EWAS Data Hub were used to perform the standardized analysis and the cluster analysis of MTIF2 methylation samples， including survival curve analysis， methylation signature analysis， the association of tumor signaling pathways， and a comparative analysis based on pan-cancer database. The independent-samples t test was used for comparison between two groups； a one-way analysis of variance was used for comparison between multiple groups， and the least significant difference t-test was used for further comparison between two groups. The Cox proportional hazards model was used to perform the univariate and multivariate survival analyses of methylation level at the CpG site. The Kaplan-Meier method was used to investigate the survival differences between the patients with low methylation level and those with high methylation level， and the Log-likelihood ratio method was used for survival difference analysis. ResultsGlobal clustering of MTIF2 methylation showed that there was no significant difference in MTIF2 gene methylation level between different races， ethnicities， BMI levels， and ages. The Kaplan-Meier survival curve analysis showed that the patients with N-Shore hypermethylation of the MTIF2 gene had a significantly better prognosis than those with hypomethylation （hazard ratio ［HR］=0.492， P<0.001）， while there was no significant difference in survival rate between the patients with different CpG island and S-Shore methylation levels （P>0.05）. The methylation profile of the MTIF2 gene based on different ages， sexes， BMI levels， races， ethnicities， and clinical stages showed that the N-Shore and CpG island methylation levels of the MTIF2 gene decreased with the increase in age， and the Caucasian population had significantly lower N-Shore methylation levels of the MTIF2 gene than the Asian population （P<0.05）； the patients with clinical stage Ⅳ had significantly lower N-Shore and CpG island methylation levels of the MTIF2 gene than those with stage Ⅰ/Ⅱ （P<0.05）. Clinical validation showed that the patients with stage Ⅲ/Ⅳ HCC had a significantly lower methylation level of the MTIF2 gene than those with stage Ⅰ/Ⅱ HCC and the normal population （P<0.05）. ConclusionN-Shore hypomethylation of the MTIF2 gene is a risk factor for the development and progression of HCC.

ObjectiveAutism spectrum disorder (ASD) is a neurodevelopmental condition characterized by difficulties with communication and social interaction, restricted and repetitive behaviors. Previous studies have indicated that individuals with ASD exhibit early and lifelong attention deficits, which are closely related to the core symptoms of ASD. Basic visual attention processes may provide a critical foundation for their social communication and interaction abilities. Therefore, this study explores the behavior of children with ASD in capturing attention to changes in topological properties. MethodsOur study recruited twenty-seven ASD children diagnosed by professional clinicians according to DSM-5 and twenty-eight typically developing (TD) age-matched controls. In an attention capture task, we recorded the saccadic behaviors of children with ASD and TD in response to topological change (TC) and non-topological change (nTC) stimuli. Saccadic reaction time (SRT), visual search time (VS), and first fixation dwell time (FFDT) were used as indicators of attentional bias. Pearson correlation tests between the clinical assessment scales and attentional bias were conducted. ResultsThis study found that TD children had significantly faster SRT (P<0.05) and VS (P<0.05) for the TC stimuli compared to the nTC stimuli, while the children with ASD did not exhibit significant differences in either measure (P>0.05). Additionally, ASD children demonstrated significantly less attention towards the TC targets (measured by FFDT), in comparison to TD children (P<0.05). Furthermore, ASD children exhibited a significant negative linear correlation between their attentional bias (measured by VS) and their scores on the compulsive subscale (P<0.05). ConclusionThe results suggest that children with ASD have difficulty shifting their attention to objects with topological changes during change detection. This atypical attention may affect the child’s cognitive and behavioral development, thereby impacting their social communication and interaction. In sum, our findings indicate that difficulties in attentional capture by TC may be a key feature of ASD.

BACKGROUND:With the development of computer-aided design and computer-aided manufacturing technology,zirconia abutments with a titanium base are widely used in clinic due to its good application advantages,but there are still some problems and a lack of consensus design standards. OBJECTIVE:To review the fabrication methods of Ti-base zirconia abutment,and the effect of abutment connection,emergence design,abutment angle,and bonding on mechanical properties of Ti-base zirconia abutment. METHODS:Relevant literature published from 2010 to 2023 was searched in CNKI and PubMed databases with the search terms"zirconia abutment,titanium base"in Chinese and English,respectively.The search time limit was extended for some classical literature.The relevant literature was obtained through inclusion and exclusion criteria,and 57 eligible documents were included for review. RESULTS AND CONCLUSION:It is recommended that clinicians try to select antirotational titanium bases or rotational titanium bases with a Morse taper connection.Implants should be placed in the correct axial angulation of not more than 15° or with an inclination to the palatal side when using angled zirconia abutments.When a≥30° labial inclination is followed for implant placement,the bite force must be decreased effectively to reduce the risk of mechanical and biological complications of implants,abutments,and prostheses.Ti-base zirconia abutments with a higher gingival height should be selected,and its restorative angle should not exceed 40°.Multilink Hybrid Abutment could be the first choice for extraoral bonding of zirconia abutment to titanium bases.

BACKGROUND:Exercises can reduce blood lipids and slow down the development of atherosclerosis.Atherosclerosis begins with mitochondrial dysfunction,and prohibitin 2 is involved in mitophagy by endurance training. OBJECTIVE:To explore the role of endurance training in the intervention of prohibitin 2 protein in the mitophagy autophagy pathway in atherosclerosis. METHODS:A total of 40 Wistar rats were randomly divided into control group,exercise group,atherosclerosis group and atherosclerosis combined with exercise group,with 10 rats in each group.A rat model of atherosclerosis was constructed by combining a high-fat diet(9 weeks)with vitamin D injections(weeks 1,3,and 6)in the latter two groups,while the two exercise groups were subjected to progressing intensity endurance training for 9 weeks.After the intervention,lipid and pathological detections were conducted to observe the modeling and interventional effects.Mitochondrial membrane potential and mitophagy proteins were detected by microplate reader and western blot.Immunofluorescence staining was used to observe the co-localization of mitophagy proteins in aortic tissue. RESULTS AND CONCLUSION:Lipid and pathological sections showed that compared with the atherosclerosis group,the serum low-density lipoprotein cholesterol and total cholesterol levels and aortic lipid deposition area were significantly reduced in the atherosclerosis combined with exercise group(P<0.001).The results of mitochondrial membrane potential showed that the significant decrease in mitochondrial membrane potential of the aorta in the atherosclerosis combined with exercise group was reversed(P<0.01).The results of western blot assay showed that compared with the control group,the mitochondrial protein expression of prohibitin 2,LC3Ⅱ/Ⅰ,PINK1 and Parkin was significantly increased(P<0.05),and the protein expression of PARL and PGAM5 decreased(P<0.05).Compared with the atherosclerosis group,the protein expression of PINK1 and Parkin in the mitchondria of rats in the atherosclerosis combined with exercise group was significantly decreased(P<0.05),and the protein expressions of prohibitin 2,LC3Ⅱ/Ⅰ,PARL and PGAM5 were significantly increased(P<0.05).Immunofluorescence results showed that compared with the control group,the co-localization of LC3 and PINK1 with TOMM20 was significantly increased in the atherosclerosis group(P<0.05),while compared with the atherosclerosis group,the co-localization of LC3 and PINK1 with TOMM20 was significantly increased in the atherosclerosis combined with exercise group(P<0.05).Co-localization of LC3 and PARL with prohibitin 2 was significantly increased in the atherosclerosis group compared with the control group(P<0.01),co-localization of LC3 with prohibitin 2 was significantly increased in the atherosclerosis combined with exercise group compared with the atherosclerosis group(P<0.01),and co-localization of PARL protein with prohibitin 2 was significantly decreased in the atherosclerosis combined with exercise group compared with the atherosclerosis group(P<0.01).To conclude,endurance training can induce the expression of prohibitin 2 in the inner mitochondrial membrane and promote the binding of prohibitin 2 to the mitophagy junction protein to complete mitophagy,restore mitochondrial function,and slow down the occurrence of atherosclerosis.

Objective: To investigate the current status and trends of depressive symptoms among middle school and college students in Hunan Province, and to explore the primary related factors of depressive symptoms, so as to provide a scientific basis for strengthening mental health among students. Methods: A total of 279 382 students in Hunan Province were selected through a stratified cluster random sampling method from 2021 to 2023. National Survey Questionnaire on Common Diseases and Health Influencing Factors among Students was adopted for the survey, and the Center for Epidemiological Studies Depression Scale was used to assess their depressive symptoms. The χ 2 test and trend χ 2 test were used to analyze depressive symptoms prevalence and trends, and multivariable Logistic regression was used to analyze the related factors of depressive symptoms. Results: The prevalence of depressive symptoms among students in Hunan Province from 2021 to 2023 were 19.66%, 20.17% and 21.47%, respectively, showing an upward trend ( χ 2 trend =9.07, P <0.01). In addition, the results of the multivariable Logistic regression analysis showed that students with healthy diet ( OR=0.43, 95%CI =0.40-0.45), adequate sleep ( OR=0.88, 95%CI =0.86-0.90), and acceptable screen time ( OR=0.61, 95%CI =0.60-0.62) had lower risks in depressive symptoms detection, while students with smoking ( OR= 1.95, 95%CI =1.88-2.02), secondhand smoke exposure ( OR=1.33, 95%CI =1.30-1.36) and Internet addiction ( OR= 4.19 , 95%CI =4.05-4.34) had higher risks in depressive symptoms detection, with differences in the degree of association among different genders, educational stages and urban rural groups ( OR=0.40-6.04, Z =-12.69-11.98) ( P <0.05). Conclusions There is an increasing trend of depressive symptoms among middle school and college students in Hunan Province from 2021 to 2023.Targeted depression prevention measures should be taken for students with different demographic characteristics to promote their mental health.

Abstract To analyzes the characteristics, problems and enlightenment of physical activity observation tools, so as to provide reference for researchers to quickly and accurately choose appropriate observation tools to evaluate children s and adolescents physical activity. Literature search is conducted in eight databases of Chinese and English, including CNKI, Wanfang, VIP, Web of Science, PubMed, Medline, ERIC, and SPORTDiscus. Ultimately, eight observation tools for assessing physical activity in children and adolescents are included. Through summarization and comparison, it is found that the applications of those tools cover multiple age groups, the observation indicators cover multiple dimensions for each with varying emphases, and the applicable contexts vary in their specific background information, and recording methods tend to be quantitative. However, several issues remain to be addressed in practical applications. First, the observation indicators need to be supplemented and improved; second, physical activity in community environments and academic classrooms requires further attention; third, physical activity intensity needs to be scientifically evaluated; fourth, observation and recording methods need to be integrated and innovated; fifth, the number of observation subjects needs to be expanded. Future research could focus on developing observation tools tailored to the characteristics of Chinese children and adolescents, while drawing on foreign observation tools to comprehensively assess physical activity among children and adolescents.

Background Work-related musculoskeletal disorders (WMSDs) are one of the major occupational health problems faced by bus drivers and should receive special attention. Objective To explore the associations of weekly working hours and sleep quality with neck and lower back WMSDs among bus drivers, as well as assess the potential mediating role of sleep quality. Methods From June to December 2022, we recruited bus drivers from 5 subsidiaries of the Shenzhen Bus Group by convenient sampling method. Demographic characteristics, lifestyles, and work-related features of the bus drivers were collected through a questionnaire survey. The Pittsburgh Sleep Quality Index (PSQI) scale and the Musculoskeletal Disorders Survey Questionnaire were used to assess sleep quality and WMSDs respectively. Logistic regression models were applied to analyze the associations of weekly working hours and sleep quality with WMSDs in neck and lower back. Furthermore, mediation analysis was performed to investigate the role of sleep quality in the associations between weekly work hours and neck and lower back WMSDs. Results A total of 1792 valid questionnaires were collected, with a response rate of 95.07%. Among these, 89.3% of the bus drivers worked more than 40 h per week, and the positive rate of poor sleep quality was 28.2%. The overall positive rate of WMSDs within one year before the survey was 69.12%. Among different body regions, the leading positive rates were identified in neck and lower back regions, at 55.92% and 53.68%, respectively. The logistic regression model showed that compared to the bus drivers with weekly work hours ≤40 h, those weekly worked (40~48] h (OR=1.43, 95%CI: 1.02, 2.01; OR=1.65, 95%CI: 1.17, 2.34), (48~56] h (OR=2.69, 95%CI: 1.89, 3.83; OR=2.30, 95%CI: 1.62, 3.29) and ＞56 h (OR=2.63, 95%CI: 1.86, 3.74; OR=3.23, 95%CI: 2.27, 4.62) had significantly increased risk of WMSDs in neck and lower back. Additionally, when compared to those with good sleep quality, bus drivers with poor sleep quality had higher risks of both neck and lower back WMSDs (OR=4.08, 95%CI: 3.20, 5.23; OR=4.15, 95%CI: 3.26, 5.30, respectively). Further mediation analysis indicated that sleep quality partially mediated the associations between weekly working hours and both neck and lower back WMSDs, with 36.15% and 33.68% as the respective proportion of mediation. Conclusion The positive rate of WMSDs is high among bus drivers, and the most common WMSDs occur in neck and lower back. Long working hours and poor sleep quality are significantly associated with increased risks of neck and lower back WMSDs. Sleep quality may mediate the associations of weekly working hours with neck and lower back WMSDs.