Objective To construct a mutant strain of Streptococcus mutans ( S.mutans ) with clpC-deletion and to investigate the role of clpC gene in genetic competence.Methods The fragment of clpC gene and the kanamycin resistant cassette flanked by two loxP sites were amplified by PCR.The purified fragment of clpC gene was cloned into pMD-19T simple vector to construct pCKX1.The pCKX1 vector was digested with ClaⅠ/EcoRⅠ, then blunted and introduced into lox71-KMR-lox66 to obtain pCKX2 vector via homologous recombination.The pCKX2 vector was linearized with SalⅠ and transformed into S.mutans UA159 strain.The positive strains constructed via homologous recombination were screened with kanamycin and transformed with the thermosensitive plasmid pCrePA.The KMR cassette was excised after incubating at 30℃ for 48 hours.Then the pCrePA plasmid was removed after overnight incubating at 37℃for the prepara-tion of clpC-deletion mutant.Total RNA were extracted from the S.mutans UA159 strain and the clpC-dele-tion mutant strain respectively, and then reverse transcribed into first strand cDNA.The target gene frag-ments were amplified by RT-PCR and analyzed by the agarose gel electrophoresis and sequencing.After be-ing verified by PCR and sequencing, the S.mutans UA159 strain and the clpC-deletion mutant strain were re-spectively transformed with E.coli-S.mutans shuttle vector pDL276 to observe the competence development induced by the competence-stimulating peptide (CSP).Results The PCR and sequencing results showed that the pCKX2 vector and the mutant strain with clpC-deletion were constructed successfully via homologous recombination.No clpC gene was detected in the clpC-deletion mutant as indicated by RT-PCR analysis.The formation of competent clpC-deletion mutant was delayed and the competence state was prolonged as com-pared with its parent strains.Conclusion The clpC gene negatively regulated the formation of competent S.mutans.

Objective:To summarize the best evidence on exercise for the prevention and treatment of diabetic foot.Methods:A bibliometric approach was used. Systematic searches were carried out to retrieve all the publicly published evidences till July 2022 on exercise for the prevention and treatment of diabetic foot, including guidelines, evidence summary, recommended practices, expert consensus, systematic review, and original research, from foreign language databases including BMJ Best Practice, UpToDate, Joanna Briggs Institute Evidence-Based Practice Database, Cochrane Library, Embase, PubMed, Guideline International Network, National Guideline Clearinghouse, Chinese databases including China National Knowledge Infrastructure, Wanfang Database, VIP Database, China Biology Medicine disc, China Clinical Guidelines Library, and the official websites of relevant academic organizations including National Institute for Health and Care Excellence of the United Kingdom, Registered Nurses' Association of Ontario of Canada, the International Working Group on the Diabetic Foot, International Diabetes Federation, American College of Sports Medicine, American Diabetes Association, and Chinese Diabetes Society. The literature was screened and evaluated for the quality, from which the evidences were extracted and evaluated to summarize the best evidences.Results:Nine guidelines, three expert consensuses, one evidence summary (with two systematic reviews being traced), two systematic reviews, 6 randomized controlled trials were retrieved and included, with good quality of literature. Totally 33 pieces of best evidences on exercise for the prevention and treatment of diabetic foot were summarized from the aspects of appropriate exercise prevention of diabetic foot, exercise therapy of diabetic foot, precautions for exercise, health education, and establishment of a multidisciplinary limb salvage team.Conclusions:Totally 33 pieces of best evidences on exercise for the prevention and treatment of diabetic foot were summarized from 5 aspects, providing decision-making basis for clinical guidance on exercise practice for patients with diabetic foot.

Objective:To develop a risk prediction model for the recurrence of diabetic foot ulcer (DFU) in diabetic patients and primarily validate its predictive value.Methods:Meta-analysis combined with retrospective cohort study was conducted. The Chinese and English papers on risk factors related to DFU recurrence publicly published in China Biology Medicine disc, China National Knowledge Infrastructure, Wanfang Database, VIP Database, and PubMed, Embase, Cochrane Library, and Web of Science, and the search time was from the establishment date of each database until March 31 st, 2022. The papers were screened and evaluated, the data were extracted, a meta-analysis was performed using RevMan 5.4.1 statistical software to screen risk factors for DFU recurrence, and Egger's linear regression was used to assess the publication bias of the study results. Risk factors for DFU recurrence mentioned in ≥3 studies and with statistically significant differences in the meta-analysis were selected as the independent variables to develop a logistic regression model for risk prediction of DFU recurrence. The medical records of 101 patients with DFU who met the inclusion criteria and were admitted to Affiliated Hospital of Guizhou Medical University from January 2019 to June 2022 were collected. There were 69 males and 32 females, aged (63±14) years. The receiver operating characteristic (ROC) curve of the predictive performance of the above constructed predictive model for DFU recurrence was drawn, and the area under the ROC curve, maximum Youden index, and sensitivity and specificity at the point were calculated. Dataset including data of 8 risk factors for DFU recurrence and the DFU recurrence rates of 10 000 cases was simulated using RStudio software and a scatter plot was drawn to determine two probabilities for risk division of DFU recurrence. Using the β coefficients corresponding to 8 DFU recurrence risk factors ×10 and taking the integer as the score of coefficient weight of each risk factor, the total score was obtained by summing up, and the cutoff scores for risk level division were calculated based on the total score × two probabilities for risk division of DFU recurrence. Results:Finally, 20 papers were included, including 3 case-control studies and 17 cohort studies, with a total of 4 238 cases and DFU recurrence rate of 22.7% to 71.2%. Meta-analysis showed that glycosylated hemoglobin >7.5% and with plantar ulcer, diabetic peripheral neuropathy, diabetic peripheral vascular disease, smoking, osteomyelitis, history of amputation/toe amputation, and multidrug-resistant bacterial infection were risk factors for the recurrence of DFU (with odds ratios of 3.27, 3.66, 4.05, 3.94, 1.98, 7.17, 11.96, 3.61, 95% confidence intervals of 2.79-3.84, 2.06-6.50, 2.50-6.58, 2.65-5.84, 1.65-2.38, 2.29-22.47, 4.60-31.14, 3.13-4.17, respectively, P<0.05). There were no statistically significant differences in publication biases of diabetic peripheral neuropathy, diabetic peripheral vascular disease, glycosylated hemoglobin >7.5%, plantar ulcer, smoking, multidrug-resistant bacterial infection, or osteomyelitis ( P>0.05), but there was a statistically significant difference in the publication bias of amputation/toe amputation ( t=-30.39, P<0.05). The area under the ROC curve of the predictive model was 0.81 (with 95% confidence interval of 0.71-0.91) and the maximum Youden index was 0.59, at which the sensitivity was 72% and the specificity was 86%. Ultimately, 29.0% and 44.8% were identified respectively as the cutoff for dividing the probability of low risk and medium risk, and medium risk and high risk for DFU recurrence, while the corresponding total scores of low, medium, and high risks of DFU recurrence were <37, 37-57, and 58-118, respectively. Conclusions:Eight risk factors for DFU recurrence are screened through meta-analysis and the risk prediction model for DFU recurrence is developed, which has moderate predictive accuracy and can provide guidance for healthcare workers to take interventions for patient with DFU recurrence risk.

Objective To summarize and explore the current state,hotspots,and trends in the field of surgical treatment for intracerebral hemorrhage(ICH)over the past decade through a bibliometric and visualization analysis of relevant literature.Methods Relevant Chinese and English literature on the surgical treatment of ICH,published from January 1,2014 to April 1,2024,was retrieved and screened from CNKI and Web of Science databases.Visualization analysis was conducted using CiteSpace,VOSviewer,and other software to analyze the number of published papers,authors,countries,institutions,etc.Social network analysis diagrams of authors,keyword clustering network analysis diagrams,keyword burst strength,and keyword timeline maps were also utilized.Results(1)A total of 3 456 relevant papers were included,with 2 173 in Chinese and 1 283 in English.From 2014 to 2021,the annual number of Chinese publications on ICH surgery was higher than that of English publications,but the number of Chinese publications began to decline from 2016.The number of English publications showed an overall increasing trend.(2)A total of 6 367 authors were identified from the English literature,with notable collaboration networks led by researchers such as Mocco J,Hanley DF,Ziai WC,You C,and Tang ZP.The Chinese literature included 6 522authors,with prominent collaboration networks led by Wang LK,Cai Q,Ku HB,Zhang S,and Zhu SQ.(3)Analysis of the countries involved in the English literature showed that 31 countries participated in research on ICH surgery,with China leading in the number of publications(505),followed by the United States(330)and Germany(106).The top three countries in centrality were the United States(0.32),China(0.16),and Canada(0.11).The top three institutions in English literature publications were Johns Hopkins University(51 papers),Ohio State University(39 papers),and Harvard University(38 papers).In China,Sichuan University(32 papers),Huazhong University of Science and Technology(30 papers),and Capital Medical University(27 papers)had multiple English publications;Wuhan University People's Hospital(15 papers),Affiliated Hospital of Guizhou Medical University(13 papers),and Affiliated Hospital of Yan'an University(13 papers)had multiple Chinese publications.There was close collaboration among research institutions in the English literature,whereas Chinese researchers often established research teams within their medical units with relatively less collaboration between teams.(4)Research on ICH surgery primarily focused on surgical methods,complications,and comprehensive perioperative treatment.Research hotspots included hypertensive ICH,minimally invasive surgical techniques,and perioperative management and treatment."neuroendoscopy"was the most recent emergent keyword in Chinese literature with high centrality and the strongest burst strength,while"randomized trial"had the highest burst strength in English literature.Research trends included the integration of artificial intelligence with minimally invasive techniques to optimize ICH surgery management and treatment strategies,analysis of risk factors,and evaluation of imaging value.Conclusions Over the past decade,the overall publication volume on the surgical treatment of ICH has been in a stable development phase,with research directions covering surgical techniques,diagnosis and treatment,evaluation,and management.Core research teams led by key authors were the main contributors to the publications.Future research hotspots and trends in ICH surgery may include the optimization of surgical techniques,complication management,large-scale multicenter clinical trials and integration of artificial intelligence with minimally invasive techniques.