髓鞘

Extraembryonic /ex·tra·em·bry·on·ic/胚外的 adj.Definition : Located outside of the embryonic body. External to the embryo proper, as the extraembryonic coelom or extraembryonic membranes.

部分神经细胞在轴突外围会被一些我们称为髓鞘细胞的细胞包围住，髓鞘细胞可使得神经细胞的冲动传递速度加快，因而形成跳跃式传递。

The notable proliferation was not observed by eyes in the local of injection. The infiltration of inflammation cells and mild proliferation of fibrocyte around dura mater was observed by HE stained in 4 and 8 weeks after injection. Infiltration and exudation of inflammation cells was observed by HE stained in epidural nerve root. Compared with group A, no changes of group B, C and D were observed under specific stained. Proliferation of type Ⅱ collagen fibers around dura mater was seen under immunohistochemical stained in 4 and 8 weeks after injection. There is no significant demyelination changes under LFB stained. The thickness and shape of the myelin sheath in epidural nerve root was not regular under transmission electronic microscopy in 4 and 8 weeks after injection. Fibroblast was also seen there. In nerve endometrium, macrophage could be seen under TEM, myelinated nerve fiber changed significantly, but nonmyelinated nerve fiber changed mildly. When 8 weeks, the changes of group D is smaller than the group B and C.

给药局部肉眼观察未见明显的纤维组织增生；HE染色可见B、C、D三组给药后四周及八周时硬膜内外均有炎细胞浸润，纤维细胞轻度增生，硬膜外神经根内有炎细胞浸润及炎性渗出；特殊染色B、C、D三组同A组相比未见有脊髓及神经根的改变；免疫组化染色，给药后四周及八周时，硬膜内外均有Ⅱ型胶原纤维增生；固兰染色B、C、D三组未见有明显脱髓鞘改变，与A组相比无明显异常改变；电镜观察B、C、D三组在给药后的四周及八周时，表现为硬膜外神经根内髓鞘厚薄不一，形状不规则，可见成纤维细胞，神经内膜中可见有巨噬细胞；粗大的有髓神经纤维变化明显，无髓神经纤维受累较轻；八周时电镜下D组改变较B、C两组为轻。

Myelin sheath thickness and maturity was superior in EFG group under electron microscopic observation.

超微结构观察：EGF组再生神经的有髓纤维数，髓鞘厚度，髓鞘的成熟度明显好于对照组。

In this paper, we first analyze the mechanism of action potential propagated alongan unmyelinated fiber, and present a hypothesis that the velocity of transmembranecurrent is the equivalent of the propagation velocity of action potential. Then usingthe H-H model and the cable equation we obtain the formula of the velocity. Insuccession, we apply a similar method to analyze the mechanism of action potentialpropagated along a myelinated fiber. Using the McNeal model and the CRRSS model,we obtain the formula of the velocity.

接下来，应用与无髓鞘神经纤维相类似的方法，分析了动作电位在有髓鞘神经纤维上的传递机制，同样得出了可用跨膜电流的移动速度来等效动作电位传递速度的结论，利用 McNeal 模型和 CRRSS 模型，建立了有髓神经纤维在兴奋传递期间等效电路模型，并推导出了速度的计算模型。

RESULTS: Chitin tubes containing NGF successfully induced the nerve regeneration, regularly arranged myelinated and unmyelinated axons could be observed across the 8 mm gaps, and the myelin sheath was thick with clear lamellar structure at 8 weeks after operation, The regenerated nerve fibers increased and were more mature at 16 weeks after operation.

结果 实验侧术后8周，再生神经中有髓和无髓神经纤维排列整齐，有髓神经的髓鞘厚，板层结构清晰；术后16周，再生神经中有髓和无髓神经纤维数量增加，形态接近正常神经。

Short-term enriched environment has positive effects on the white matter and myelinated fibers in the white matter in 24-month male rats.

提示短期丰富生存环境可能促使老年雄性大鼠白质内已经发生脱髓鞘改变的有髓神经纤维出现髓鞘再生。

The signal intensity characteristic of MRI associated with brain myelinization is helpful to differentiate the normal and abnormal brain maturation.Also,T1WI is much more useful in the detection of immature myelin and in monitoring of normal brain development in the first 6 months of life.On the other hand,T2WI is more useful after 6 months of life.

不同月龄段不同解剖部位正常脑髓鞘化具有各自MRI信号特征，有利于评判是否脑发育正常和患脑白质病，T1WI评估未成熟髓鞘较好，T2WI确定髓鞘是否成熟较好。

Electrophysciological indexes: in the experimental group ,the tardy rate of induced motorius action potential ,recovery rates of the amplitude of compound muscle action potential and twitch tension and tetanic tension of triceps surae muscle ,were significantly higher than in the control group.(4) Compared with the control group ,the triceps surae muscle wet weight was significantly greater in the experimental group.(5) histomorphological indexes: the count of myelinated nerve fibers ,diameter of regenerated axon,thickness of nerve myelin sheath and area of capillary were much more in the experimental group than in the control group.(6) observation of ultrastructure with the transmission election microscope: more abundant organella and maturer myelin sheath lay in the injured peripheral nerve of the experimental group, while not lay in the control group.

分别在术后第2、4、6周时进行各项指标的检测，结果发现：（1）实验组SD大鼠在整个实验过程中，其精神、毛发、体重，运动灵活性等一般情况优于对照组；（2）实验组的坐骨神经功能指数恢复率显著优于对照组，P＜0.01；（3）神经电生理指标：实验组运动神经诱发电位潜伏期的延迟率显著优于对照组，P＜0.05；复合肌肉动作电位振幅的恢复率显著高于对照组，两组比较第2周时P＜0.01，第4、6周时，P＜0.05；小腿三头肌单收缩力和强直收缩力的恢复率实验组显著高于对照组，P＜0.01；（4）小腿三头肌湿重的恢复率，第2、4周时实验组高于对照组，差异非常显著，P＜0.01；第6周时，差异仍显著，P＜0.05；（5）组织形态学指标：有髓神经轴突计数、再生轴突直径的恢复率，毛细血管面积，实验组均显著大于对照组，P＜0.01、P＜0.05、P＜0.001；实验组髓鞘厚度的恢复率也显著高于对照组，第2周时P＜0.01，第4、6周时，P＜0.05；（6）透射电镜超微结构观察：实验组再生轴突中细胞器丰富，髓鞘结构成熟，神经再生情况优于对照组。

While the tissue spaces surrounding a few blood vessels wasAl and Fg positive,no Al or Fg positive cells were observed.In antemortem injurygroup,diffuse subarachnoid hemorrhage,cerebral edema,swelling or pyknotic neu-rons could be observed.The axons showed irregular swelling and disconnection at1～3h,marked swelling and disconnection at 6h,and retraction ball at 15h whichwas more remarkable at 24h after injury.The space between myelin sheaths andaxons was increased at 3～6h after injury.Tortuous and wavelike myelin sheathswhich adhered on axons incompletely,or even peeled off could be found from 15hto 24h after injury.Perinuclear lysis of Nissl bodies began at 24h after injury.Thenumber of GFAP positive cells in cerebrum and brain-stem increased significantlyfollowed by decrease,and then increased again,but the time courses of the changesin different areas of brain were not same.Al and Fg positive neural cells,mainlysurrounded blood vessels,with diffuse or peripherally distributed positive matter incytoplasm could be observed at 0.5h after injury.The number of Al or Fg positivecells and the intensity of immunoreaction increased with the time of injury.The areaof SYN positivity in medulla oblongata and pons decreased notably 3～6h afterinjury,then return to normal levels and continued to 24h after injury.

生前损伤组，可见广泛蛛网膜下腔出血，脑组织水肿，神经细胞肿胀，晚期神经元固缩；伤后1～3h见部分神经轴突不规则增粗、断裂，伤后6h断端膨大，伤后15h可见收缩球，至伤后24h更为明显；伤后3～6h可见部分神经髓鞘与轴突之间的间隙增宽，伤后15h髓鞘明显曲折，不完全附着在轴突两侧，甚至剥脱，持续到伤后24h；核周尼氏体减少在伤后24h才开始出现；同一部位的GFAP阳性细胞数目随损伤时间发生改变，先增多（最早在伤后0.5h），达到高峰后减少，其后又有增多趋势，但不同部位的GFAP阳性细胞数目增减的时间过程不尽相同，同时，大脑中的GFAP阳性细胞数目也有改变；伤后0.5h，可在脑干组织中见到Al和Fg阳性神经细胞，主要位于血管周围，阳性物在胞浆中呈弥散性分布，但部分细胞的阳性物仅分布于靠近胞膜的胞浆中而呈环状，随损伤时间延长，阳性细胞数目增多，反应强度增加；伤后3～6h，延髓及桥脑中的SYN阳性物面积减少，其后恢复到正常水平，并持续到伤后24h。

All the indexes were tested in 2 -. 4 .. 6 weeks of operative intervals respectively. Results:(1) The general observation in the experimental group ,such as spirit, hair, body weight and activity ,was superior to that in the control group.(2) The recovery rate of sciatic nerve functional index (SF1) was statistically significantly higher in the experimental group than in the control group .(3) electrophysciological indexes: m the experimental group ,the tardy rate of induced motorius action potential ,recovery rates of the amplitude of compound muscle action potential and twitch tension and tetanic tension of triceps surae muscle ,were significantly higher than in the control group.(4) Compared with the control group ,the triceps surae muscle wet weight was significantly greater in the experimental group.(5) histomorphological indexes: the count of myelinated nerve fibers ,diameter of regenerated axon, thickness of nerve myelin sheath and area of capillary were much more in the experimental group than in the control group.(6) observation of ultrastructure with the transmission election microscope: more abundant organell a and maturer myelin sheath lay in the injured peripheral nerve of the experimental group, while not lay in the control group.

分别在木后第2、4、6周时进行各项指标的检测，结果发现：（1）实验组SD大鼠在整个实验过程中，其精神、毛发、体重，运动灵活性等一般情况优于对照组；（2）实验组的坐骨神经功能指数恢复率显著优于对照组，P＜0.01；（3）神经电生理指标：实验组运动神经诱发电位潜伏期的延迟率显著优于对照组，P＜0.05；复合肌肉动作电位振幅的恢复率显著高于对照组，两组比较第2周时P＜0.01，第4、6周时，P＜0.05；小腿三头肌单收缩力和强直收缩力的恢复率实验组显著高于对照组，P＜0.01；（4）小腿三头肌湿重的恢复率，第2、4周时实验组高于对照组，差异非常显著，P＜0.01；第6周时，差异仍显著，P＜0.05；（5）组织形态学指标：有髓种经轴突计数、再生轴突直径的恢复率，毛细血管面积，实验组均显著大于对照组，P＜0.01、P＜0.05、P＜0.001；实验组髓鞘厚度的恢复率也显著高于对照组，第2周时P＜0.01，第4、6周时，P＜0.05；（6）透射电镜超微结构观察：实验组再生轴突中细胞器丰富，髓鞘结构成熟，神经再生情况优于对照纽。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。