MMP-9 deficiency accelerates the progress of periodontitis

Periodontitis is a chronic inflammatory disease caused by periodontopathic bacteria that affects periodontal support tissues.1 If left untreated,it results in loss of periodontal attachment and alveolar bone resorption.Approximately one-half of adults in the United States older than 30 years have periodontal disease.2 Though the disease is initiated by bacterial infection,it activates host defense systems that eventually lead to the degradation of the periodontium.During periodontitis,the disease progress involves further production of pro-inflammatory mediators such as cytokines,proteolytic enzymes like matrix metalloproteinases(MMPs),and their inhibitors.

Shining light on transition metal sulfides:New choices as highly efficient antibacterial agents

Globally,millions of people die of microbial infection-related diseases every year.The more terrible situation is that due to the overuse of antibiotics,especially in developing countries,people are struggling to fight with the bacteria variation.The emergence of super-bacteria will be an intractable environmental and health hazard in the future unless novel bactericidal weapons are mounted.Consequently,it is critical to develop viable antibacterial approaches to sustain the prosperous development of human society.Recent researches indicate that transition metal sulfides(TMSs)represent prominent bactericidal application potential owing to the meritorious antibacterial performance,acceptable biocompatibility,high solar energy utilization efficiency,and excellent photo-to-thermal conversion characteristics,and thus,a comprehensive review on the recent advances in this area would be beneficial for the future development.In this review article,we start with the antibacterial mechanisms of TMSs to provide a preliminary understanding.Thereafter,the state-of-the-art research progresses on the strategies for TMSs materials engineering so as to promote their antibacterial properties are systematically surveyed and summarized,followed by a summary of the practical application scenarios of TMSs-based antibacterial platforms.Finally,based on the thorough survey and analysis,we emphasize the challenges and future development trends in this area.

锥形束计算机断层摄影定位观察人类拔牙后牙槽突外形变化规律的可行性研究(英文)

研究目的:探讨同一患者不同时期所拍的锥形束计算机断层摄影(CBCT)是否因每次拍摄时投照角度不可能完全一致而影响数据测量的准确性。创新要点:提出了一种人类后牙拔除后观察牙槽突外形变化的准确、无创、科学的定位方法。研究方法:选择首都医科大学附属北京口腔医院种植中心60名患者两份于上颌后牙种植前后拍摄的CBCT影像资料。以磨牙根分叉区三个牙根开始分开处(图像上显示为三根恰好融合的点)为基准点定位两次CBCT的起始水平断层。在第一次CBCT的起始水平断层上,连线牙列远端磨牙参照点即矢状断层起点与近端双尖牙的髓室中心进行矢状断层重建。若实验牙为第一磨牙,找到通过其腭根髓室中心的矢状断层;若实验牙为第二双尖牙,找到通过其髓室中心的矢状断层。记录由矢状断层起点到实验牙移动的层数N,在水平断层上测量实验牙牙槽骨宽度,在实验牙髓室中心的矢状断层上测量牙全长。在第二次CBCT中依据第一次记录的移动层数N定位矢状断层,在定位后的矢状断层上测量实验牙全长,在水平断层的相应定位处测量牙槽骨宽度。重要结论:利用本研究提出的定位方法可以精准定位同一患者不同CBCT影像资料中的同一断层,从而实现拔牙位点动态连续观察。