Objective:To evaluate the effects of platform switching and platform matching system on the marginal bone resorption a-round implant.Methods:Randomized controlled trials (RCTs)that compared marginal bone loss around platform-switched implants with platform matched prostheses were selected from PubMed,EMbase,CBM,CNKI and other electronic databases supplemented by hand search and retrospective collection of literature published or unpublished between 1 991 -201 4.The literature based on inclusion and exclusion criteria was screened by 2 revieweres independently,the quality of the included studies was evaluated,the data were extracted using RevMan 5.2 software for Meta-analysis.Results:1 4 studies with 1 331 implants were included.Meta-analysis showed that peri-implant bone resorption in the platform switching group was significantly less than that in the platform matching group[MD =-0.51 ,95% CI:(-0.72 -0.30),P <0.01 ].Subgroup analysis showed that the implant-abutment diameter difference >0.45 mm (unilateral)was more favorable to implant marginal bone preservation.Conclusion:The present data suggest that platform-switched technology is more conducive to implant bone preservation than platform-matched method.

Renal transplantation is the optimal approach to improve the quality of life and restore normal life for patients with end-stage renal diseases.With the development of medical techniques and immunosuppressants, the shortterm survival of renal graft has been significantly prolonged, whereas the long-term survival remains to be urgently solved.Renal ischemia-reperfusion injury (IRI), acute rejection, chronic renal allograft dysfunction, renal fibrosis and other factors are still the major problems affecting the survival of renal graft.Relevant researches have always been hot spots in the field of renal transplantation.Meantime, 2020 is an extraordinary year.The novel coronavirus pneumonia (COVID-19) pandemic severely affects the development of all walks of life.Researches related to renal transplantation have also sprung up.In this article, the frontier hotspots of clinical and basic studies related to renal transplantation and the COVID-19 related researches in the field of renal transplantation in China were reviewed, aiming to provide novel therapeutic ideas and strategies.

Over the past 70 years, kidney transplantation has become not only the most mature but also the highest-success-rate surgery among all organ transplantation surgeries. However, the long-term survival of kidney transplant recipients is still challenged by such key factors as ischemia-reperfusion injury related to kidney transplantation, rejection, chronic renal allograft dysfunction, renal allograft fibrosis, immunosuppressive therapy, infections and others. Relevant fundamental and clinical studies have emerged endlessly. At the same time, the research related to kidney transplantation also becomes a new hot spot accordingly in the context of the normalization of novel coronavirus pneumonia. This article reviewed the cutting-edge hot spots in relation to the fundamental and clinical aspects of kidney transplantation together with relevant new techniques and new visions. The studies included in this article focused on the reports published by Chinese teams that are more applicable to the current situation of kidney transplantation in China, for the purpose of providing new thoughts and strategies for the diagnosis and treatment of kidney transplantation related issues in China.

OBJECTIVETo investigate the effect of TiO₂nanotube arrays covalently modified by recombinant human bone morphogenetic protein- 2(rhBMP- 2) on the early bioactivity of mesenchymal stem cells (MSC) in vitro and to provide experimental evidence for the biochemical modification of titanium implants.

METHODSIn the experiment group, double titanium nanotube arrays were prepared by anodization, and were chemically grafted with rhBMP- 2. Mechanically polished pure titanium was used as blank control group, and titanium dioxide nanotubes was used as negative control A group, and titanium dioxide nanotubes + carbonyldiimidazole as negative control B group. Field emission scanning electron microscope (FE- SEM) and X- ray photoelectron spectroscopy (XPS) were used to detect the morphology and physicochemical properties of the experiment group, blank control group and the negative control group. Cell adhesion on the specimen surface of the experiment group, blank control group and negative control group on the 1st day was tested. Cell proliferation on the 1st, 3rd and 5th day and alkaline phosphatase activity on the 5th, 7th and 11th day was also tested.

RESULTSFE- SEM showed that the surface of titanium nanotubes loaded with rhBMP- 2 possessed visible miliary particulate matter. XPS showed that nitrogen peak in the group of titanium nanotubes loaded with rhBMP-2 was significantly greater that those in the other groups. FE- SEM showed that the cells on the surface of the experimental group on the 1st day spread well, better than those in the control group and negative control group. Cell proliferation activity on the 1st day in different groups was not obvious (P>0.05), the A value of the experimental group on the 3rd and 5th day (3.295 ± 0.153, 3.823 ± 0.059) were significantly higher than those in the control group (2.479 ± 0.064, 3.131 ± 0.096) and negative control A group (2.715 ± 0.075, 3.371 ± 0.047) and negative control B group (2.756 ± 0.132, 3.637 ± 0.047) (P<0.05). Alkaline phosphatase activity on the 5th, 7th and 11th day in the experimental group (0.0477 ± 0.0287, 0.0615 ± 0.0016, 0.0667 ± 0.0018) were better than those in the control group, negative control A group and negative control B group (P<0.05).

CONCLUSIONSTitanium nanotube arrays can be loaded with rhBMP-2 by biochemical methods and have good biocompatibility.

Alkaline Phosphatase ; metabolism ; Bone Morphogenetic Protein 2 ; pharmacology ; Cell Adhesion ; Cell Proliferation ; Humans ; Materials Testing ; Mesenchymal Stromal Cells ; Microscopy, Electron, Scanning ; Nanotubes ; chemistry ; ultrastructure ; Photoelectron Spectroscopy ; Recombinant Proteins ; pharmacology ; Surface Properties ; Titanium ; chemistry ; Transforming Growth Factor beta ; pharmacology

Objective To compare the change features of anti-donor specific antibody (DSA) in different species of sentitized mice after skin transplantation. Methods All mice were divided into the Balb/c → C57BL/6 (6 pairs) and Balb/c → C3H skin transplantation groups (6 pairs). At d0, d2, d4, d7, d13, d17, d28, d35, d42, d49 and d56 after skin transplantation, the serum sample was prepared for detection of DSA-IgG and DSA-IgM levels. Results Moderate increase was noted in the DSA-IgG level in the sensitized mice within 1 week after skin transplantation. The IgG level was significantly increased within 1-4 week and peaked and stabilized within 4-8 week. No significant variation was observed in the DSA-IgM level at 8 weeks after skin transplantation. In the Balb/c → C57BL/6 skin transplantation group, the DSAIgG level was significantly lower than that in the Balb/c → C3H group. Statistical significance was identified in the IgG levels between two groups at d2, d17, d28, d35, d42, d49 and d56 after skin transplantation (all P<0.05). No statistical significance was noted in the DSA-IgM levels between two groups at each time point (all P>0.05). Conclusions Advancing the time of renal transplantation after skin transplantation moderately in the Balb/c → C3H group, or changing to the lower immunoreactive combination of Balb/c → C57BL/6 are aimed to establish AMR mouse models with mild rejection reaction.

Objective: To investigate the application of Symptom Checklist-90 (SCL-90) in Chinese nurses. Methods: We performed a literature search for articles in Chinese on the mental health of nurses investigated using the SCL-90 that were published from January 2007 to December 2016. A total of 129 articles were included, involving 178 groups of valid samples as well as 36316 subjects in 27 provinces or cities in China. The metafor package of R 3.2.1 software and Excel were used for meta-analysis and data statistics. Results: Heterogeneity was identified for the nine factors included in the literature data (Q test: P<0.05; I² test >40%) , so a random effects model was used. For all factors except interpersonal relationship factor, the 95% confidence intervals of the pooled effect sizes did not include 0. For all factors except interpersonal relationship factor (Egger test: P<0.05) , no significant asymmetry or incompleteness appeared in the funnel plots. The fail-safe number of each factor was much larger than 5k+10. The merger scores and mean values of nine factors were higher than the national norm. Conclusion The SCL-90 is widely used in the study of mental status of Chinese nurses, but the SCL-90 norm for nurses is lacking.

Objective: To investigate the status of abnormal menstruation in female nurses in a comprehensive hospital in Beijing, China and related influencing factors. Methods: In July 2016, a cross-sectional survey was performed, and a self-administered questionnaire was used to investigate the status of menstruation and occupation in female nurses in a comprehensive hospital in Beijing. The chi-square test and a multivariate logistic regression analysis were used for statistical analysis. Results: A total of 892 female nurses were investigated, and among them, 485 experienced abnormal menstruation within the past three months, resulting in an abnormal menstruation rate of 54.37%. The female nurses who were exposed to harmful factors during work, negative life events, or high workload had a significantly higher abnormal menstruation rate than those who were not exposed to such factors (χ²=5.199, 16.186, and 10.227, P<0.05 or P<0.01) . Negative life events (odds ratio [OR]=1.813, 95% confidence interval[CI]: 1.317-2.496) and high workload (OR=1.461, 95%CI: 1.112-1.918) were risk factors for abnormal menstruation. Conclusion Nurses have an abnormal menstruation rate as high as 54.37%, and high workload and negative life events were risk factors for abnormal menstruation in nurses.

Objective: To evaluate the mental health of occupational females in different industries. Methods: We investigated the psychologic status of Chinese occupational females using symptom checklist 90. And statistical software was applied to analyze results of symptom checklist 90. Results: There were 41, 166 effec-tive questionnaires. The number of positive questionnaires was 14 361, and the positive rate was 34.89%. The positive rate of obsessive-compulsive factor was 24.07%. The positive rate of somatization factor was 16.12%. The positive rate of depression was 15.50%. The median positive item number was 20 (IQR: 34) , and the median split of positive symptoms was 2.11 (IQR: 0.37) . There were differences in the positive rate of SCL-90 scale among different age groups, different regions and different industries, the difference was statistically significant (P<0.05) . The positive rate of SCL-90 for the occupational females was 34.89%. The top three factors of the high-est positive SCL-90 were obsessive-compulsive symptoms, somatization and depression. Conclusion There were differences in the psychological status of occupational females for different regions, different ages and different occupations.

Objective: To investigate the prevalence of reproductive system diseases among female workers in a city and related occupational influencing factors. Methods: From June to September, 2016, a cross-sectional survey was used to select 9 944 female workers from six districts of Beijing and then a face-to-face questionnaire survey was performed. Univariate analysis using chi-square test and multivariate logistic regression analysis were used to investigate the risk factors for reproductive system diseases. Results: The age of 9944 female workers ranged from 18 to 65 years (mean 35.53±9.52 years) , and among them, 7 351 (73.92%) were married. The overall prevalence rate of reproductive system diseases among these 9944 female workers during the past three months was 28.29%, and the prevalence rates of hyperplasia of mammary glands, vaginitis, and hysteromyoma were 15.54%, 11.25%, and 6.77%, respectively. After adjustment for age, marital status, education level, and annual family income, the multivariate logistic regression analysis showed that frequent overtime work (odds ratio[OR]=1.119, 95% confidence interval[CI]: 1.070-1.343) , frequent night shifts (OR=1.198, 95%CI: 1.054-1.361) , standing for a long time (OR=1.197, 95%CI: 1.063-1.347) , sitting for a long time (OR=1.327, 95%CI: 1.191-1.479) , heavy workload (OR=1.429, 95%CI: 1.262-1.615) , exposure to lead (OR=1.696, 95%CI: 1.307-2.201) , exposure to mercury (OR=1.452, 95%CI: 1.086-1.940) , and exposure to ionizing radiation (OR=1.679, 95%CI: 1.424-1.980) were associated with reproductive system diseases. Conclusion The prevalence of reproductive system diseases among female workers in Beijing is not optimistic. Reproductive system diseases are associated with frequent overtime work, frequent night shifts, standing for a long time, sitting for a long time, heavy workload, and exposure to lead, mercury, and ionizing radiation.

Objective: To evaluate the mental health of female doctors and nurses. Methods: Investigat the psychologic status of female doctors and nurses using symptom checklist 90. And statistical software was applied to analyze results of symptom checklist 90. Results: There were differences in the score of SCL-90 between doctor and nurse groups, the difference was statistically significant (P<0.05) . Negative life events (OR=2.940) , relative suffer from mental illness (OR=3.683) , shift work (OR=1.611) and heavy workload (OR=2.265) were found to risk factors for the positive of SCL-90. Conclusion There were differences in the score of SCL-90 between doctor and nurse groups. Negative life events, relative suffer from mental illness, shift workand heavy workload are risk factors for SCL-90 positive of female doctors and nurses.