牙根

Objective To evaluate the effect of enamel matrix protein on the attachment and proliferation of periodontal ligament cells on diseased cementum surfaces in vitro.

目的观察釉基质蛋白对牙周膜细胞在牙周炎患牙牙骨质根面上附着和增殖的影响。方法用EMP处理的牙周炎患牙根片为实验组，用生理盐水处理的患牙根片和健康牙根片分别作为对照。

Then we hypothesize that mesenchyma stem cells from DAC are heterology,which have the potential ability to regenerate root/periodontal complex structures as a new kind of seed cells. Therefore, this study focuses on characteristics of the mesenchyma stem cells at tooth root developing stage and the evaluation of the possibility of being seeds cells.

因此，本研究拟对牙根发育期相关间充质干细胞的生物学特性进行研究，探讨其作为种子细胞在牙根/牙周组织工程中应用的可行性，以期为组织工程化牙根/牙周组织构建优选新的种子细胞。

The fractures of roots were associated with morphology of roots and incremental lines in dentine.

含2个根管的扁牙根形态较多发生牙根裂。牙本质中的生长线是牙根组织结构上的弱点。

Pereme , separately are 209%,295%,285%; the increasing of accumulating amount separately are 209%,295%,285%; The use of silicon has a tread to rise dry weight of Bermudagrass ,Agrostis Lolium. Pereme ; Under the drought condition , the use of silicon suppressed the reducing of the relative water content of leaf in turfgrass , delaying the time of wither , stress for the 11th day in the drought .compared with water normally and not using silicon ,after use silicon, the RWC of Bermudagrass , Agrostis Lolium. Pereme only separately depressed 14%,16%,32%; Under the drought condition ,the use of silicon can increased the content of proline of Bermudagrass ,Agrostis Lolium. Pereme, stress for the 11th day in the drought and using silicon , compared with water normally and ueing silicon, the content of Pro separately increased 203%,199%,473%;The using of silicon depressing the ET of Bermudagrass and Lolium. Pereme.Under water normally condition, separately depressed 21%,8% at eleven days ;Under drought condition , separately depressed 17%,5%.

施硅增加了草坪草狗牙根、剪股颖和黑麦草的含硅量，分别为209％、295％、285％；积累量分别提高了240％、364％、355％；施硅对草坪草狗牙根、剪股颖和黑麦草的干物质积累有促进趋势；在干旱的条件下，施硅抑制了草坪草的叶相对含水量的降低，延迟了叶片萎焉的时间，在干旱胁华中农业大学2001级时一艳丽硕士学位论文迫第n天，与正CK相比，施硅后狗牙根、剪股颖和黑麦草分别只降低了 14%；16%，32%。；施硅增加了狗牙根、剪股颖、黑麦草在干旱条件下脯氨酸的含量，增强了渗透调节能力，在干旱施硅的条件下，与正51相比，在干旱胁迫第11天，狗牙根、剪股颖和黑麦草脯氨酸的含量分别增加了2叨%、199%、473%；施硅减少了狗牙根和黑麦草的蒸散量在正常浇水的条件下，与正CK相比，第11天狗牙根和黑麦草的蒸散量分别降低了21%、吕%；在干旱的条件下，与干CK相比，在干旱胁迫的第11天，狗牙根和黑麦草的蒸散量分别降低了17%、5%。

Using stereomicroscope, we observed the fracture line direction and location as well as the angle between the fracture line and the attrite plane. The data was compiled into statistics and analyzed. The results revealed that most of the vertical root fractures occurred in teeth with severe attrite crown and flat root. Numerous bucco-lingual oriented fractures occurred in the mesial root of molars, and we found three non-endodontically treated cases with mesio-distal oriented fractures in the palatal roots.

结果发现，两组的垂直牙根断裂均好发於牙冠严重磨耗（77.4-88.2%）且扁平的牙根（61.8-75.8%）上，以大臼齿的近心牙根发生率最高（64-85.7%），多为颊舌侧走向（91.2-91.9%），且於未根管治疗组别亦发现三例腭侧根断裂，走向为较宽的近远心方向，显示牙根断裂会沿著牙根较宽的方向发生；同时，未经根管治疗而产生垂直牙根断裂的牙齿具有根叉位置较低的现象（61.8%），牙根於比例上有较短小的特徵。

Compared with the temperature of 25℃, the difference of the enzyme activity of SOD and POD, contents of PRO and REL of Festuca Lolium perenne L. and Cynodon dactylon at the temperature of 5℃ had been studied. The results showed that the 4 indexes above had less difference at the temperature of 25℃; after 20h treatment at the temperature of 5℃, the activities of SOD of Lolium perenne L.

用5℃低温处理黑麦草和狗牙根，并以25℃为对照，比较低温胁迫下，黑麦草和狗牙根超氧化物歧化酶、过氧化物酶、脯氨酸和电导率的差异，结果表明，25℃时上述5个指标差别不大，5℃处理20h时，黑麦草和狗牙根的SOD活性均达到峰值，分别为处理4h时的2.88倍和2.87倍，但24h后狗牙根的SOD活性减少速率明显大于黑麦草。

The major factors for callus induction, differentiation, and Agrobacterum-mediated transformation were investigated in the current paper, using the creeping stem nodes of Cynodon dactylon as the original materials.

以主要暖季型草坪草狗牙根的匍匐茎节为试验材料，对其愈伤组织的诱导、分化以及农杆菌介导转化的关键因子进行优化，以此为基础将除草剂抗性基因bar导入狗牙根中，并对抗除草剂狗牙根的推广应用作了探讨。

There are experimental results as follows:(1) Eriophorum comosum Nees shows strong cold resistance in plasmalemma permeability research. The lethal temperature of Eriophorum comosum Nees is the lowest LT_(50 in comparison with another two plants and is lower than -11.5℃ in August 2005 and December 2005; Soluble protein content of each plant is rising before or after cold hardiness. By SDS-PAGE, Protein band is analysed. Band quantity of Eriophorum comosum Nees is the most and its band color is darkest.(2) Soluble sugar content of three plants after cold hardiness are higher than before cold hardiness, moreover soluble sugar content after cold hardiness shows a decline and there is a narrow range in Eriophorum comosum Nees; Free Proline accumulation is changed by cold stress, and cold resistance is relative to free Proline accumulation; chlorophyll content of both three plants, including chlorophyll a, chlorophyll b and chlorophyll a/b, show a decline tendency along with the descent of temperature. Cynodon dactylon is highly sensitive to cold stress.(3) The soil POD and urease activities' absolute value of Erioophorum comosum Nees and Pogonatherum panideumHack were more than that of Cynodon dactylon before or after low temperature stress, especially POD activities.

实验结果表明：(1)在膜透性的研究中，丛毛羊胡子草抗寒性最强，采用电导率法测得半致死温度LT_(50最低，丛毛羊胡子草抗寒锻炼前后半致死温度LT_(50均小于-11.5℃；在可溶性蛋白含量研究中，抗寒锻炼前后三种植物的可溶性蛋白含量均增加，同时采用SDS-PAGE法，通过对蛋白条带分析，以丛毛羊胡子草条带数最多且着色深；(2)在可溶性糖的研究中，三种植物经抗寒锻炼后叶片可溶性糖含量都比抗寒锻炼前高，且经过抗寒锻炼后三种植物可溶性糖均呈下降趋势，丛毛羊胡子草可溶性糖含量下降较小；从游离脯氨酸含量可知，低温的胁迫影响了植物叶片游离脯氨酸的含量变化，植物的抗寒性与游离脯氨酸有关；低温胁迫下三种植物叶绿素含量随着温度的下降，叶绿素含量、叶绿素a、叶绿素b和叶绿素a／b均呈下降趋势，狗牙根对低温胁迫最为敏感；(3)低温锻炼前后，丛毛羊胡子草和金发草的土壤过氧化物酶与脲酶活性的绝对值均大于狗牙根的，特别是过氧化物酶，说明丛毛羊胡子草和金发草的酶活性大于狗牙根的。

Maxillary second molar has five subtype, Type A: absence of root fusion, Type B: presence of mesiobuccal and distobuccal root fusion, Type C: palatal root with anyone of buccal root fusion of molar with three roots, Type D:complete root fusion of molar with three roots, Type E:pseudofusion of molar.

分析其牙根发育沟之发生率、牙根发育沟之长度、牙根发育沟至牙骨质牙本质交界的距离，以及牙根发育沟最深点的深度、占牙根长的位置、与到牙根根管的距离，并且将牙根分类为上颚第一大臼齿，仅一种分类。

objective to evaluate clinical effect of the handling protaper nickel-titanium rotary instruments in preparation of canals of posterior teeth.methods 96teeth with pulpitis or periapical periodontitis were instrumented by handling protaper rotary instruments using step-down technique,and by k files using step-back technique for control.all teeth were obturated with lateral condensation methods.the efficiency of preparation was analyzed with ra-diographs before and after operation.results no transportation,apical blockage and ledge were found in test.the technique could keep canals smooth.there were two ledge,one instrument fracture and nine transportation in control.the operative time was shorter and post treatment pain seldom occurred in handling protaper group.conclusion the handling protaper niti rotary instruments can prepare the canals effectively and safety.after the preparation,the canals could be easily washed,sterilized and filled.it is an efficient instrumentation method for posterior teeth's canals and be used widely.

目的 评价手用protaper预备后牙根管的临床效果。方法选取患有牙髓炎和根尖周炎的后牙96例，随机分成试验组和对照组各48例，试验组用手用protaper多锥度镍钛旋转器械逐步伸入法预备根管，对照组用k锉，逐步后退法预备根管，两组均用侧向加压充填法充填根管，根据治疗前后的x线片，评价后牙根管预备效果。结果试验组无根管偏移、根尖阻塞、台阶，且根管壁平滑流畅，无器械折断等并发症发生。对照组有2例台阶形成，器械折断1例，根管偏移9例。试验组操作时间短且术后疼痛轻微。结论应用手用protaper预备后牙根管快速、安全，成形效果好，易于根管冲洗消毒及填充，可视为临床上预备后牙根管的有效方法。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。