应用牙槽骨锥形束CT评估牙周序列治疗疗效的观察性比较研究

目的:应用锥形束CT（CBCT）评价重度慢性牙周炎基础治疗对比基础治疗合并翻瓣手术治疗的疗效。方法:选取近3年初诊的重度慢性牙周炎患者,纳入仅进行牙周基础治疗的20例和进行基础治疗合并翻瓣手术治疗20例为研究对象,对治疗前后上颌前磨牙进行牙周探诊深度（PD）、附着丧失水平（CAL）的临床效果观察,并拍摄CBCT,利用CBCT随机软件测量牙槽骨骨密度（ABD）。对两组间治疗前后疗效指标的变化值进行协方差分析。结果:共40名研究对象合计治疗评估145颗患牙,其中基础治疗组72颗,基础治疗合并翻瓣手术组73颗。基础治疗合并翻瓣手术治疗组治疗前后PD（-1.25 vs.-2.00,P<0.001）的降低,牙槽骨密度ABD（0.027vs.0.059,P<0.001）的增高较单纯基础治疗组更加明显,两组在CAL变化差值表现不明显。结论:基础治疗合并翻瓣手术治疗比单纯基础治疗在临床指数PD以及牙槽骨密度等方面疗效变化更好。      

东北地区民营经济发展路径及空间组织形式

东北老工业基地的改造和振兴,国有企业的改制、改组和改造,激活地方经济,资源型城市和地区结构转型和发展接续产业,实现社会公平等,都离不开民营经济的发展和积极参与,发展民营经济也是解决“东北现象”和“新东北现象”的根本途径。文章通过对东北老工业基地民营经济发展特点和现状的阐述,以及对该地区发展民营经济优势条件的分析,提出了民营经济发展战略及其指导下的发展民营经济的地域组织形式和路径。     

太湖鲂鲌F2代GH基因结构、系统发育和表达特征

采用PCR及T-A克隆技术,从基因组DNA成功克隆三角鲂、太湖鲂鲌、太湖鲂鲌F₂代含完整阅读框的生长激素基因全序列,经测序拼接获得序列全长分别为6009、6042和6058bp,转录单元长分别为2049、2014和2045bp。三种群体的GH基因序列均包括五个外显子、四个内含子及5''侧翼区和3''侧翼区;编码氨基酸序列均为633bp,编码210个氨基酸。对3个目14种鱼类进行同源性及系统发育分析发现,太湖鲂鲌F₂代与其祖父母的遗传距离相比亲本较近。另取10尾太湖鲂鲌F₂代,对其进行GH基因编码区SNPs筛选,共得到7处SNPs,其中有3处位点的突变导致其氨基酸序列发生了明显的变化;对其蛋白质结构分析发现,突变后的氨基酸残基导致蛋白质二级结构发生改变。我们将该10尾个体按体重分为小个体组和大个体组,经组织表达分析发现,大个体组中的个体具有较高的转录水平,进一步分析发现其氨基酸残基有所不同。     

藏东地区斜坡土壤冻融侵蚀力学机制及敏感性分析

冻融侵蚀是青藏高原草甸覆盖区的主要侵蚀方式,以气候条件一致的藏东地区斜坡表层土壤侵蚀为对象,基于区域地质条件和土体赋存特征,分析了土壤剥蚀输移的力学过程,探索了缓变的隐性因子和灾变的显性因子对冻融侵蚀的作用机制.结果表明:①地表冻融侵蚀是自基岩风化和土壤演化起始,经历冻融拉裂破坏与沙土输移,到重新裸露基岩的一个循环演化...     

Temperature and silicate are significant driving factors for the seasonal shift of dominant diatoms in a drinking water reservoir

The individual or combined ef fect of water temperature and silicate on seasonal shift of dominant diatom species in a drinking water reservoir in China was studied in this paper. These ef fects were analyzed based on the field investigation of temporal dynamics in species composition and abundance of phytoplankton and environmental factors from September 2015 to August 2016. We firstly found that six dominant diatom species( Fragilaria nanana, Achnanthidium catenatum, Aulacoseira ambigua, Ulnaria ulna, Cyclotella meneghiniana and Asterionella formosa(Class Bacillariophyceae)), which accounted for98.7% of the total abundance of diatoms and 46.8% of the total abundance of phytoplankton, showed an obvious seasonal succession. Then significant driving factors for seasonal shift of the dominant diatom species were selected by Redundancy Analysis. The result showed that water temperature and silicate were the main environmental factors af fecting the growth of diatoms on temporal scales. Next, the regressions of water temperature and silicate and dominant diatom abundance were fitted in Generalized Additive Model separately, and the smoothers of water temperature and diatom species suggested that the dominant diatom species adapted to dif ferent optimum temperature ranges, which corresponded with the growth of seasonal changes. A positive linear correlation between silicate and diatom abundance was generated by Generalized Additive Model. Finally, the ordinal controls of water temperature and silicate on the growth of diatoms were analyzed on temporal scales specifically. We suggested that water temperature and silicate controlling the growth of diatoms in order. Diatoms grow well only when the two controlling factors simultaneously satisfy the growth conditions; as limiting factors, the two factors played their respective limiting roles in turn on temporal scales.     

顾及栅格空间拓扑关系的地表覆盖时空目标不一致性探测方法

地表覆盖与更新是地理国情监测、环境变化评估、生态系统保护等不可或缺的基础地理信息。遥感制图技术已成为地表覆盖信息提取的重要手段,但因地物光谱、纹理及时相等特征复杂性,地表覆盖更新数据往往存在错分、漏分,从而导致地表覆盖时空目标不一致。现有地表覆盖更新数据不一致性探测主要以人工检查为主、部分自动化为辅的方式,生产实践中需要大量的作业人员与时间,缺乏行之有效的不一致性自动化探测工具。本文研究分析了栅格地表覆盖更新数据不一致性检查面临的挑战,提出了基于复合逻辑量词的栅格空间拓扑关系计算方法、基于置信区间的更新期地表覆盖错分目标初判规则构建,以及利用空间约束多重匹配的更新期错分目标后验判断,形成了“关系-规则-判断”的地表覆盖时空目标不一致性探测体系。试验以山东临朐、垦利GlobeLand30数据为研究对象,经与统计一致性检核方法对比分析、参照真实地表影像数据,实现了地表覆盖时空目标不一致性探测与有效性检验,验证了探测方法可行性。     

蟠龙油田长2油藏油气富集控制因素

蟠龙油田延长组长2油层属典型的低渗—超低渗储层;富含有机质的烃源岩为油气的生成提供了物质保障;广泛发育的泛滥平原相、沼泽相泥岩为油气成藏提供了良好的盖层条件。研究认为长2油藏以构造—岩性复合油气藏为主,油气富集主要受物性、岩性及岩相等因素影响。有利的沉积相带、储层物性及鼻状隆起构造共同控制了长2油藏的油气分布。     

Lessons learnt from Typhoons Fitow and In-Fa: implications for improving urban flood resilience in Asian Coastal Cities

Natural Hazards - Frequent typhoons significantly affect many coastal cities via intensive rainstorms, tidal surges and strong wind. Natural factors induced by human disturbance such as climate...     

黄土地震滑坡卫星影像识别方法

为获得详细的地震滑坡数据和分布特征,揭示黄土地震滑坡的成灾模式和防治措施,需要对黄土地区地震滑坡进行详细的编录,利用卫星影像的识别方法是重要的手段之一。通过总结黄土地震滑坡特有的空间分布特征、平面形态特征、地震滑坡发育特征和伴生水文特征,归纳利用卫星影像识别黄土地震滑坡的7种识别标志。利用该方法,研究通渭地区黄土地震滑坡的空间分布与规律,结果表明：黄土地震滑坡卫星影像识别方法获得的滑坡与野外现场调查结果相近;通渭地区滑坡拥有缓坡发育、低角度、中远滑距、大体积、方向性明显等特点。