摘要：AIM:To design and validate broad-range 16S rRNA primers for use in high throughput sequencing to classify bacteria isolated from the human foregut ***:A foregut microbiome dataset was constructed using 16S rRNA gene sequences obtained from oral,esophageal,and gastric microbiomes produced by Sanger sequencing in previous studies represented by 219 bacterial *** primers evaluated were from the European rRNA *** assess the effect of sequence length on accuracy of classification,16S rRNA genes of various lengths were created by trimming the full length *** spanning various hypervariable regions were selected to simulate the amplicons that would be obtained using possible primer *** sequences were compared with full length 16S rRNA genes for accuracy in taxonomic classification using online software at the Ribosomal Database Project (RDP).The universality of the primer set was evaluated using the RDP 16S rRNA database which is comprised of 433 306 16S rRNA genes,represented by 36 ***:Truncation to 100 nucleotides(nt)downstream from the position corresponding to base 28 in the Escherichia coli 16S rRNA gene caused misclassification of 87(39.7%)of the 219 sequences,compared with misclassification of only 29(13.2%)sequences with truncation to 350 *** 350-nt sequence reads within various regions of the 16S rRNA gene,the reverse read of an amplicon generated using the 343F/798R primers had the least(8.2%)effect on *** comparison,truncation to 900 nt mimicking single pass Sanger reads misclassified 5.0%of the 219 *** 343F/798R amplicon accurately assigned 91.8%of the 219 sequences at the species *** by abundance of the species in the esophageal dataset,the 343F/798R amplicon yielded similar classification accuracy without a significant loss in species coverage(92%).Modification of the 343F/798R primers to 347F/803R increased their universality among foregut ***

摘要：相对于下颌无牙颌来说,上颌无牙颌的修复重建更有挑战性。毫无疑问,种植覆盖义齿大大改善了无牙颌病人的生活质量。但是对于影响种植体支持或固位的覆盖义齿寿命的风险因素,如骨质下降和骨量不足、间隙不足和生物机械压力等方面仍然存在争议。鉴于此,本文就已知的这些治疗设计及修复设计中的风险因素通过系统性的文献回顾分析和病例展示进行讨论和阐释。

摘要：比色对于牙医来说是一个具有挑战的问题。在哈佛大学,我们一直在探寻将颜色从艺术领域引入到牙科学领域的方法。本文将就在哈佛大学牙学院进行的有关色彩学的不同方面的几项研究结果进行讨论,回顾分析并评估影响种植修复体视觉效果和比色的因素。色彩学研究的目的是为了给患者提供最好的美学修复效果。目前,种植修复治疗已经常规化,色彩和美观随之已经成为种植修复的重要考虑因素。由此我们已经进入了种植修复治疗的新阶段。