A histological and biomechanical study of bone stress and bone remodeling around immediately loaded implants

Immediate loading(IL)increases the risk of marginal bone loss.The present study investigated the biomechanical response of peri-implant bone in rabbits after IL,aiming at optimizing load management.Ninety-six implants were installed bilaterally into femurs of 48 rabbits.Test implants on the left side created the maximal initial stress of 6.9 and 13.4 MPa in peri-implant bone and unloaded implants on the contralateral side were controls.Bone morphology and bone-implant interface strength were measured with histological examination and push-out testing during a 12-week observation period.Additionally,the animal data were incorporated into finite element(FE)models to calculate the bone stress distribution at different levels of osseointegration.Results showed that the stress was concentrated in the bone margin and the bone stress gradually decreased as osseointegration proceeded.A stress of about 2.0 MPa in peri-implant bone had a positive effect on new bone formation,osseointegration and bone-implant interface strength.Bone loss was observed in some specimens with stress exceeding 4.0 MPa.Data indicate that IL significantly increases bone stress during the early postoperative period,but the load-bearing capacity of peri-implant bone increases rapidly with an increase of bone-implant contact.Favorable bone responses may be continually promoted when the stress in peri-implant bone is maintained at a definite level.Accordingly,the progressive loading mode is recommended for IL implants.     

Intracellular levels of calmodulin are increased in transformed cells

By using Hoechst 33342,rabbit anti calmodulin antibody,FITC-labeled goat anti rabbit IgG and SR101(sulfo rhodamine 101)simultaneously to stain individual normal and transformed cells,the microspectrophotometric analysis demonstrated that 3 markers which represented the nucleus,calmodulin and total protein respectively,could be recognized in individualj cells without interference,The phase of the cell cycle was determined by DNA content(Hoechst 33342),We found that in transformed cells(NIH3T3) tsRSV-LA90,cultured at 33℃ and transformed C3H10T1/2 Cells),the ration of calmodulin to total protein (based on the phases of cell cycle)was higher than that in normal cells (NIH3T3 tsRSV-LA90 cells,cultured at 39℃ and C3H10T1/2 cells)in every cell cycle phase,This ration increased obviously only from G1 to S phase in either normal or transformed cells.The results showed that calmodulinreally increased during the transformation,and its increase was specific.In the meantime when cells proceeded from G1 to S.the intraceollular calmodulin content also increased specifically.     

MYCOLOGY IN CHINA WITH EMPHASIS ON REVIEW OF THE ANCIENT LITERATURE

<正> Ⅰ.Ancient Literature ReviewThe edibility and medicinal use of fungi were known to Chinese ancestors long,long ago.Our fathers recognized and used them as food,as medicine,in agriculture,in industry,for fermentation,etc.Fungi such as common mushrooms,wood ear,jellyfungus(Tremella fusiformis)have been used for food;china root(Poria coccus),ca-     

从公共数据库中利用数据挖掘的方法开发15条黄金鲈EST-SSR标记

黄金鲈是美国中西部地区重要的淡水经济型鱼类。TypeⅠ型标记对于比较作图和遗传学研究有相当重要的作用, 但是黄金鲈的TypeⅠ标记数量相当少。研究通过数据挖掘的方法从公共数据库中挖掘黄金鲈的TypeⅠ型即EST-SSR标记。实验结果分析了21968条EST序列, 约14.4%的序列包含不同类型的核心重复单元。CA重复是最丰富的二碱基重复单元。从中挑选62条包含SSR的EST序列设计引物, 筛选得到15对多态的微卫星位点。群体遗传学参数显示15对EST-SSR位点的等位基因数范围为4—19(平均数为9), 观测杂合度和期望杂合度的范围分别为0.103—0.929和0.116—0.934, 有4个位点偏离HWE平衡。研究得到的EST-SSR标记适用于黄金鲈的群体遗传学和基因组作图研究。     

小麦种子贮藏蛋白的遗传学研究进展

AdvanceofGencticStudiesonSeedStoragcProteininWheatWangGang;JiJing;HuHan(InstituteofGenetics,AcadcmiaSinica,Beijing100101)小麦是世界上最重要的粮食作物之一．对其品质的研究具有十分重要的意义．多年来,人们一直在寻求改良小麦品质的途径,以满足不同食品加工对小麦各种品质的需求．但只是近10年里,对决定小麦品质位点的遗传及生物化学的研究才取得了突破性的进展（主要集中于英国、美国及澳大利亚）．本文将着重介绍目前国际上对小麦种子贮藏蛋白的遗传学及生物化学研究现状,至于如何将这些研究成果结合到育种工作…     

130例智力低下儿童脆性X检测报告

本文采用脆性 X检测技术对130例先天性智力低下儿童进行了细胞遗传学研究,结果共发现27例具有染色体异常。其中t(5;15)及t(8;12),inv(9)两例核型,经鉴定为世界首报核型;检出5例脆性X综合征,检出率为3.77%,占异常核型的18.5%。 Abstract:The cytogenetic study was made on 130 mentally retarded children with the technique of Fra(X) detection.Among the 27 mentally retarded children with chromosomal abnormalities found in the study,the two karyotypes of t (5;15) and t (8;21),inv(9) were first reported in the literature.of the 130 mentally retarded cases,5 had fragile (X) syndrome (3.77%).The syndrome accounted for 18.5% in the abnormal karyotypes.     

枸杞耐盐变异体的筛选及植株再生

枸杞(Lycium barbarum L.)无菌苗下胚轴于MS+2,4-D 0.25mg/L+LH 50 0mg/L的诱导培养基上产生胚性愈伤组织。经0.34%的EMS(半致死剂量)处理并恢复增殖2周后, 将存活组织转接到含有1.5%NaCl的诱导培养基上培养4周,再将少数存活的组织转移到含1.0%NaCl的同样培养基上继续培养,经不断选择,选出了耐1.0%NaCl的愈伤组织变异体。经耐盐性、耐盐稳定性、脯氨酸含量、叶绿素含量分析,以及对山梨醇、聚乙二醇的反应证明,该愈伤组织是耐盐变异体。变异体在含有1.0%NaCl的分化培养基(MS+6-BA0.5mg/L)上可分化出再生植株。     

小麦T型细胞质雄性不育系与相应保持系线粒体DNA的RAPD分析

利用RAPD技术对小麦T型细胞质雄性不育系75-3369A和相应保持系75-336 9B 的线粒体DNA(mtDNA)进行了81个单引物和14组双引物的多态性研究。结果有73个单引物和全部的双引物有扩增结果,表现出多态性的有10个单引物和一组双引物。 Abstract:Using 81 single-primers and 14 double-primers,T-type CMS(cytoplasmic male sterile)line 75-3369 A and is maintainer 75-3369B were studied by means of RAPD.73 single-primers and all double-primers gave amplified products in the experiment,among them 10 single-primers and one double-primer presented polymorphism.     

油用向日葵主要农艺性状的遗传分析

对10个油用向日葵品种的主要农艺性状进行遗传分析的结果表明,株高、单株粒数、百粒重、盘径和单株粒重等农艺性状具有较大的遗传率,可以在早代单株选择或直接选择;出苗-现蕾、现蕾-开花、开花-成熟、皮壳率等性状的遗传率较低,应根据各性状间相关关系进行间接选择或将选择推迟到晚期世代进行。遗传变异幅度较大的性状有皮壳率、单株粒数、小区产量、单株粒重等。由于性状的遗传改良效果主要由该性状的遗传率和变异幅度及选择强度所决定,因此,在选择率确定为5%情况下,遗传改良效果较好的性状为单株粒数和单株粒重。 Abstract:The genetic analysis of main agronomic characters was conducted with 10 varieties of oil sunflower(Helianthus annuus L.).The results showed that direct selection can be carried out at early generation for characters with higher heritability such as plant height,grain number pere plant,100-grain weight,diameter of disc and grain weight per plant.For maturity and percentage of shell with lower heritability,indirect selection correlated with other characters or late generation selection can be utilized.The characters showing wide genetic variation were those as percentage of shell,grain number per plant,grain yield per plot and grain weight.Since the successful improvement of a character mainly depends on its heritability,variation of heritability and intensity of selection,we suggest that the characters which may give better genetic improvement are grain number and grain weight per plant under condition of 5% selection pressure.     

猫叫综合征一家系高分辨染色体分析

本文采用高分辨染色体技术,对一例猫叫综合征患儿及其家系进行了分析,结 果提示,猫叫综合征染色体关键片段位于5p15.3→5pter。