Objective To explore the relationship between different vaginal community state type(CST)and preterm birth during pregnancy.Methods Retrieved from PubMed,Web of Science,Elsevier Science Direct,CNKI,Wanfang Data Knowledge Service Plat-form and VIP database for published literature on the relationship between vaginal CST and preterm birth from the establishment of the da-tabase to June 2024.References were screened according to inclusion and exclusion criteria and information was extracted.The obtained data were statistically analyzed using Revman 5.4 and Stata 16.0software.Results A total of 13 cohort studies were included,involving a total of 1959 pregnant women,involving 5 vaginal CST identified by 16SrRNA high-throughput gene sequencing analysis.Four of which were dominated by Lactobacillus,they were CST Ⅰ curled Lactobacillus,CST Ⅱ Graveli Lactobacillus,CST Ⅲ inert Lactobacillus and CST V Jenner Lactobacillus.The other one was CST Ⅳ low Lactobacillus.The results of network Meta-analysis showed that the risk of preterm birth induced by each CST was ranked from highest to lowest as CST Ⅴ＞CST Ⅳ＞CST Ⅲ＞CST Ⅱ＞CST Ⅰ,and there was no statistically significant difference in the risk of preterm birth caused by each CST.In the early pregnancy sampling group(sampling gestational age＜14 weeks),CST Ⅳ increased the risk of preterm birth compared with CST Ⅰ,and the difference was statistically signif-icant(P＜0.05).In the Asian population,the highest risk of bacteria causing preterm birth was ranked as CST Ⅴ＞CST Ⅱ＞CST Ⅳ＞CST Ⅰ＞CST Ⅲ,and there was no statistically significant difference among the CST groups.Conclusion The current study showed that there was no statistically significant difference in the risk of preterm birth caused by various types of vaginal CST during the whole pregnan-cy,but subgroup analysis showed that CSV Ⅳ increased the risk of preterm birth compared with CST Ⅰ in early pregnancy,and the difference was statistically significant.Sampling gestational age and race may influence the results of the study,and more high-quality and large sample studies are needed to explore the relationship between vaginal CST and preterm birth.

Objective To explore the relationship between different vaginal community state type(CST)and preterm birth during pregnancy.Methods Retrieved from PubMed,Web of Science,Elsevier Science Direct,CNKI,Wanfang Data Knowledge Service Plat-form and VIP database for published literature on the relationship between vaginal CST and preterm birth from the establishment of the da-tabase to June 2024.References were screened according to inclusion and exclusion criteria and information was extracted.The obtained data were statistically analyzed using Revman 5.4 and Stata 16.0software.Results A total of 13 cohort studies were included,involving a total of 1959 pregnant women,involving 5 vaginal CST identified by 16SrRNA high-throughput gene sequencing analysis.Four of which were dominated by Lactobacillus,they were CST Ⅰ curled Lactobacillus,CST Ⅱ Graveli Lactobacillus,CST Ⅲ inert Lactobacillus and CST V Jenner Lactobacillus.The other one was CST Ⅳ low Lactobacillus.The results of network Meta-analysis showed that the risk of preterm birth induced by each CST was ranked from highest to lowest as CST Ⅴ＞CST Ⅳ＞CST Ⅲ＞CST Ⅱ＞CST Ⅰ,and there was no statistically significant difference in the risk of preterm birth caused by each CST.In the early pregnancy sampling group(sampling gestational age＜14 weeks),CST Ⅳ increased the risk of preterm birth compared with CST Ⅰ,and the difference was statistically signif-icant(P＜0.05).In the Asian population,the highest risk of bacteria causing preterm birth was ranked as CST Ⅴ＞CST Ⅱ＞CST Ⅳ＞CST Ⅰ＞CST Ⅲ,and there was no statistically significant difference among the CST groups.Conclusion The current study showed that there was no statistically significant difference in the risk of preterm birth caused by various types of vaginal CST during the whole pregnan-cy,but subgroup analysis showed that CSV Ⅳ increased the risk of preterm birth compared with CST Ⅰ in early pregnancy,and the difference was statistically significant.Sampling gestational age and race may influence the results of the study,and more high-quality and large sample studies are needed to explore the relationship between vaginal CST and preterm birth.

According to the related standards, an in vitro corrosion fatigue testing of coronary stents was designed. The stents were fixed in the latex tubes, which were full of 0.9% saline solution, and radial stress was produced for simulating natural vessel. The accelerated fatigue test was performed with 4 x 10(8) cycles at a frequency of 60 Hz, which was equal to 10 years in vivo implantation. Twelve coronary stents made from stainless steel were adopted in the experiment. The bulk structure and surface morphology before and after testing were analysed by scanning electron microscopy. The structure damage and surface change caused by corrosion fatigue were identified and the probable reasons were proposed.
Biocompatible Materials ; chemistry ; Computer Simulation ; Corrosion ; Equipment Failure Analysis ; Humans ; Materials Testing ; Models, Cardiovascular ; Stainless Steel ; chemistry ; Stents ; Time Factors