全文获取类型
收费全文 | 347篇 |
免费 | 9篇 |
国内免费 | 25篇 |
专业分类
381篇 |
出版年
2023年 | 2篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 8篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 11篇 |
2008年 | 15篇 |
2007年 | 8篇 |
2006年 | 13篇 |
2005年 | 6篇 |
2004年 | 15篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 31篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 14篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 8篇 |
1972年 | 1篇 |
排序方式: 共有381条查询结果,搜索用时 16 毫秒
91.
92.
Osamu Sato Takeyasu Maeda Shigeo Kobayashi Toshihiko Iwanaga Tsuneo Fujita Yasuo Takahashi 《Cell and tissue research》1988,251(1):13-21
Summary Nervous elements in the periodontal ligament and dental pulp of rat incisors were investigated by means of immunohistochemistry for neurofilament protein (NFP) and glia-specific S-100 protein. The periodontal ligament in the incisors was densely innervated by NFP-immunoreactive nerve fibers; the distribution of the nerve fibers and their terminations differed markedly from those in molars. NFP-positive, thick nerve bundles entered the lingual periodontal ligament through slits located in the mid-region of the alveolar socket, and immediately formed numerous Ruffini-like corpuscles. In the labial periodontal ligament, all of the NFP-immunoreactive nerve fibers terminated in free endings. The restricted location of the stretch receptor, Ruffini-like corpuscle, in the lingual periodontal ligament appears to be an essential element, because this region is regularly extended during mastication. The nervous elements were restricted to the alveolar half of the periodontal ligament in every region; they avoided the dental half of the periodontal ligament, which presumably moves continuously with the tooth. Pulpal nerve fibers in incisors also showed a characteristic distribution different from those in molars; individual nerve fibers with beaded structures ran in the center of the pulp toward the incisai edge, and did not form the subodontoblastic nerve plexus of Raschkow.Immunostaining for S-100 protein revealed a distribution pattern of nervous elements similar to that for NFP, suggesting that the nerves supplying the periodontal ligament and dental pulp were mostly covered by a Schwann sheath. 相似文献
93.
Dr. Tatsuo Ushiki Toshihiko Iwanaga Toru Masuda Yasuo Takahashi Tsuneo Fujita 《Cell and tissue research》1984,235(3):509-514
Summary The present study deals with the localization and ultrastructure of S-100-immunoreactive cells in the human thymus. These immunoreactive cells are distributed mainly in the medulla with some scattered elements in the cortex. Electron-microscopic observation revealed that the cells are characterized by an irregularly shaped nucleus, tubulovesicular structures in the cytoplasm and characteristic interdigitations of the plasma membrane. The cells often embrace lymphocytes with their branched processes. On the basis of these morphological features, the immunostained elements were identified as interdigitating cells (IDCs). The immunocytochemistry for S-100 visualizes the precise distribution and extension of the IDCs under the light microscope and indicates that the IDCs form no structural networks such as those established by the thymic epithelial cells. Since the IDCs in human lymph nodes have also been reported to contain S-100-like immunoreactivity, S-100 protein can be regarded as a useful marker for identifying the IDCs in the human thymus and other lymphoid organs. 相似文献
94.
Q热立克次体中国株的16S—23S rDNA间区序列分析 总被引:1,自引:0,他引:1
用PCR扩增了7株中国分离株(七医、新桥、雅安、李、YS-8、YS-9和YH-11)和2株国株参考株(Henzerling和Grita)的16S-23S rDNA基因间区,对扩增产物进行了序列分析。结果发现它们仅在少数几个碱基位上有不同。在第60位上3个云南分离株YS-8、YS-9、YH-11和Grita株与Stein等报道的序列(包括九里、其它国际参考株和一些法国临床分离株)的碱基序列一致,为“C”;其他5株为“A”,此位点的不同可能与适应不同的地理环境相关。另外,YS-9株在第8和208位、新桥株在第432位也分别出现缺失,可能与适应不同的动物宿主或在实验室传代情况不同有关。 相似文献
95.
The time courses of changes of three enolase isozymes (alpha alpha, alpha gamma, and gamma gamma), S-100 protein, 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase), ornithine decarboxylase (ODC), beta-galactosidase, and glucose-6-phosphate dehydrogenase (G6PDH) were examined from 1 to 14 days after cutting of the preganglionic nerve (denervation) or the postganglionic nerve (axotomy) of the superior cervical sympathetic ganglion (SCG) of the rat. The wet weight and protein content in the axotomized SCG increased continuously, to nearly twice those of the denervated SCG for 1-2 weeks after the operations. Among enolase isozymes in the SCG, neuron-specific gamma gamma-enolase decreased rapidly after denervation and stayed at a low level for 2 weeks, whereas the isozyme remained almost unchanged after axotomy. On the contrary, ganglionic alpha alpha-enolase and the alpha gamma-hybrid form increased remarkably to reach a maximum at the second day after axotomy, and remained above control for 1 to 2 weeks; these two enolase isozymes showed little change after denervation. Denervation caused a much larger increase than did axotomy in the ganglionic S-100 protein, an astrocyte-specific protein, during the first week after the operation, while the protein content decreased after 2 weeks of either denervation or axotomy. CNPase, a myelin-associated enzyme, rose suddenly 2 days after axotomy, and remained at a rather high level compared with the denervated ganglion, which showed little variation.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
96.
Several procedures were employed to examine the in vitro interaction between S-100 proteins and microtubule proteins. Binding of S-100 to tau factors was observed under all experimental conditions. S-100 binding to microtubule-associated protein 2 (MAP2) was best detected by exposing nitrocellulose-immobilized MAP2 or MAPs to either 125I-labeled S-100 or biotinylated S-100. S-100 binding to tubulin was detected when the two protein fractions were first incubated with each other followed by exposure to the bifunctional cross-linker disuccinimidylsuberate, and then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and transfered onto nitrocellulose paper. By this procedure, complex formation between S-100 and tubulin, as well as between S-100 and a relatively low-molecular-weight MAP, was evidenced by immunoblotting using an anti-S-100 antiserum. Alternatively, complex formation between biotinylated S-100 and either tubulin or MAPs was visualized by means of avidin-peroxidase, after SDS-PAGE of the complex mixtures and transfer of the separated proteins onto nitrocellulose. The interaction between S-100 and tubulin was strictly Ca2+ dependent, and resistant to high concentrations of KCl, colchicine, or vinblastine. 相似文献
97.
应用Sephacryl S-100-HR凝胶层析、高效液相色谱(HPLC)和反相高效液相色谱(R-HPLC)分析,从巨噬细胞条件培养基中纯化了巨噬细胞源性神经营养因子(MΦDNF)。该因子在SDS-聚丙烯酰胺凝胶电泳上呈现一条单一蛋白带,其分子量为60.5kD,等电点约5.1。其氨基酸组成含有较高比例的天冬氨酸、谷氨酸、亮氨酸和赖氨酸。纯化的MΦDNF能支持体外培养的小脑皮质神经元的存活,增强其活性及促进神经元突起的生长。其最大效应浓度为500—1000ng/ml。 相似文献
98.
探讨前列腺癌微环境中DCs与各类血细胞的关系及临床预后价值.选取16例良性前列腺增生和42例前列腺癌患者的前列腺组织作为研究对象,以S-100、CD83、CD208抗体作为不同状态的DC标记物进行MaxVision法免疫组化染色和Masson染色.采用图像分析软件进行图像处理,其统计数据与患者外周血细胞计数进行统计学分析.S-100、CD83阳性细胞计数和胶原蛋白含量在前列腺增生组较前列腺癌组高(P<0.05).CD208阳性细胞计数在前列腺增生组和前列腺癌组无差异(P>0.05).S-100阳性细胞计数与Gleason评分呈负相关关系(r=-0.533,P<0.01).血小板计数在前列腺癌组较前列腺增生组高(P<0.05).单核细胞计数偏高为前列腺癌危险因素(P<0.05).各类型树突状细胞与血小板计数无直线相关关系(P>0.05).外周血各成熟类型细胞与前列腺癌微环境中DCs计数无明显相关关系.S-100标记的树突状细胞计数可能与前列腺癌患者的预后相关.更大量样本的分析有助于证实单核细胞计数与前列腺癌的发病以及S-100标记树突状细胞计数与前列腺癌的预后之间的相关性. 相似文献
99.
Mutagenicity of several nitroso derivatives of piperazine was assayed using histidine auxotrophic strains of Salmonella typhimurium. Nitroso derivatives of piperazine required metabolic activation with preference to phenobarbital induced rat-liver microsomal enzymes. We observed a good correlation between a positive effect in the mutation assay and the carcinogenic potency of the compound. Even though our results are not in complete agreement with earlier published work using several microbial mutation assay systems, the differences we observed demonstrate the predictive value of an in vitro activation system using S. typhimurium to detect carcinogenic compounds as mutagens. 相似文献
100.
Summary The presence of an S-100-like immunoreactivity was investigated in the planarian Dugesia gonocephala. By microcomplement fixation assay, measurable amounts of S-100-like immunoreactive material (0.11g/mg soluble protein) were detected in planarian high-speed supernatants. The index of immunological dissimilarity between ox S-100 and planarian S-100-like immunoreactive material was higher than that previously calculated between ox S-100 and all the vertebrates tested. By the immunohistochemical PAP method, S-100-like immunoreactivity was only detectable in the cilia of the epidermal cells. Although the biological meaning of S-100-like immunoreactivity in planarian remains to be clarified, the present data introduce new perspectives into the investigation of S-100. 相似文献