富血小板纤维蛋白在正畸减数拔牙中对拔牙位点保存的应用研究

目的:研究富血小板纤维蛋白(platelet-rich fibrin,PRF)对减数拔牙后的牙槽窝进行位点保存,及减数后正畸提供足够骨量的临床效果。方法:选取正畸需拔除4颗第一前磨牙的安氏Ⅰ类成年患者28例,年龄范围18～25岁;并将每例患者拔牙窝左右分为对照组与实验组。实验组拔牙后于拔牙窝内充填PRF凝胶并以PRF膜覆盖;对照组拔牙后使拔牙窝内滞留血凝块,不做其他处理。观测分析上颌牙槽骨高度、上颌牙槽窝骨密度指标及正畸治疗尖牙远移到位后的牙龈折痕出现情况。结果:术后1个月、术后2个月实验组BCH、MCH、CCH、DCH、P/LCH测量值明显小于对照组,差异均有统计学意义; BMH、BDH、P/LMH、P/LDH测量值差异将均无统计学意义。实验组牙龈折痕出现数量少于对照组,差异有统计学意义。结论:PRF应用于拔牙位点保存可加速牙槽窝新骨形成,增加牙槽窝骨密度,同时可有效减少牙龈折痕的出现。河北省项目科技厅资助项目(项目编号182777101D

Studies on the movement, home range, and habitat use of greylag geese (Anser anser) based on satellite tracking

营养和能量有效的积累对候鸟能否顺利完成迁徙具有重要意义。2015年8月至10月在内蒙古图牧吉湿地,利用卫星跟踪技术对灰雁的活动特征、生境利用等方面进行了研究,以期阐明灰雁在秋季如何有效积累能量以满足迁徙前的生理需求。我们采用增强型植被指数(EVI)分析了灰雁的生境特征,运用核密度分析法(KDE)计算了日间和夜间活动区面积,以及对不同月份的平均活动距离进行了分析。结果表明,8至10月间,灰雁活动位点的EVI值逐月递减,并且逐渐向南移动,趋向于水域集中,增加了对湖泊的利用,同时减少了对草地的利用;灰雁的活动区面积逐月递增,日间活动区面积大于夜间;灰雁在日间、夜间及平均活动距离均呈递增的趋势,每天凌晨及黄昏都出现较长时间的活动。由于8至10月间气温逐渐降低,从草地中可以获取的潜在食物资源减少,灰雁通过逐渐向水域较为丰富的区域移动,活动区面积逐渐增大,增加活动距离提高食物的获取量等确保获取足够的食物和能量满足迁徙的需求

Systematic Korea Microlensing Telescope Network planetary anomaly search – III. One wide-orbit planet and two stellar binaries

ABSTRACT Only a few wide-orbit planets around old stars have been detected, which limits our statistical understanding of this planet population. Following the systematic search for planetary anomalies in microlensing events found by the Korea Microlensing Telescope Network, we present the discovery and analysis of three events that were initially thought to contain wide-orbit planets. The anomalous feature in the light curve of OGLE-2018-BLG-0383 is caused by a planet with mass ratio q = 2.1 × 10−4 and a projected separation s = 2.45. This makes it the lowest mass-ratio microlensing planet at such wide orbits. The other two events, KMT-2018-BLG-0998 and OGLE-2018-BLG-0271, are shown to be stellar binaries (q &amp;gt; 0.1) with rather close (s &amp;lt; 1) separations. We briefly discuss the properties of known wide-orbit microlensing planets and show that the survey observations are crucial in discovering and further statistically constraining such a planet population.</jats:p