全文获取类型
收费全文 | 7506篇 |
免费 | 418篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 66篇 |
妇产科学 | 85篇 |
基础医学 | 1106篇 |
口腔科学 | 240篇 |
临床医学 | 523篇 |
内科学 | 1802篇 |
皮肤病学 | 83篇 |
神经病学 | 536篇 |
特种医学 | 218篇 |
外科学 | 1156篇 |
综合类 | 48篇 |
预防医学 | 312篇 |
眼科学 | 65篇 |
药学 | 753篇 |
中国医学 | 17篇 |
肿瘤学 | 908篇 |
出版年
2022年 | 71篇 |
2021年 | 130篇 |
2020年 | 58篇 |
2019年 | 79篇 |
2018年 | 101篇 |
2017年 | 80篇 |
2016年 | 97篇 |
2015年 | 88篇 |
2014年 | 127篇 |
2013年 | 145篇 |
2012年 | 247篇 |
2011年 | 341篇 |
2010年 | 165篇 |
2009年 | 192篇 |
2008年 | 299篇 |
2007年 | 295篇 |
2006年 | 303篇 |
2005年 | 326篇 |
2004年 | 305篇 |
2003年 | 304篇 |
2002年 | 304篇 |
2001年 | 261篇 |
2000年 | 295篇 |
1999年 | 270篇 |
1998年 | 92篇 |
1997年 | 63篇 |
1996年 | 82篇 |
1995年 | 72篇 |
1994年 | 55篇 |
1993年 | 50篇 |
1992年 | 225篇 |
1991年 | 233篇 |
1990年 | 229篇 |
1989年 | 236篇 |
1988年 | 186篇 |
1987年 | 175篇 |
1986年 | 202篇 |
1985年 | 155篇 |
1984年 | 103篇 |
1983年 | 97篇 |
1982年 | 54篇 |
1979年 | 81篇 |
1978年 | 50篇 |
1977年 | 58篇 |
1975年 | 41篇 |
1974年 | 53篇 |
1973年 | 51篇 |
1969年 | 62篇 |
1968年 | 51篇 |
1967年 | 46篇 |
排序方式: 共有7961条查询结果,搜索用时 15 毫秒
51.
M Imai T Shibata K Moriguchi M Yamamoto H Hayama 《Okajimas folia anatomica Japonica》1991,68(2-3):155-160
Some researchers have already described the fowl proventriculus. However, we believed there was a need for detailed carbohydrate histochemical investigations on the same glands. Moreover, some researchers had erred about the lamina muscularis mucosae. The results of these investigations are as follows. 1. The proventricular glands consist of both superficial and profound gastric glands. 2. The superficial glands are distributed in the lamina propria mucosae while the profound glands exist in the tela submucosa. 3. The superficial glands are simple, branched tubular glands. The columnar glandular cells are arranged in a simple layer and react strongly to PAS, AB (pH 2.5 and 0.5). These appear to be dark purple when they are stained with PAS-AB (pH 2.5). Some other methods have also been tried. 4. Judging from the data 3), the superficial gastric glands contain neutral, weak and strong acids, sulfuric and acid mucopolysaccharides, sialomucin, and II and III neutral mucus type. 5. Glandular cells in the body and basal portions of the superficial gastric glands contain a large number of fine pepsinogen granules. 6. Judging from the data of 3)-5), we believe that the superficial gastric glands are undifferentiated gastric glands and that they are same kinds of glands that are found in mammals. 7. A large number of profound gastric glands fill the tela submucosa. They are compound tubular glands, and are composed of many glandular alveoli. Their columnar glandular cells are arranged in a simple layer. 8. These glandular cells react moderately to PAS, negatively to AB (pH 2.5 and 0.5) and PAS-AB (pH 2.5). Moreover, we observed some other reactions.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
52.
The Epstein-Barr virus (EBV) has been detected in certain types of lymphoma and some epithelial neoplasms including nasopharyngeal lymphoepithelioma, and rare lymphoepithelioma-like carcinomas occurring in a variety of organs including, most recently, the stomach. The authors investigated the possibility that EBV may be present not only in the rare gastric cancers that resemble nasopharyngeal lymphoepithelioma, but also in typical gastric adenocarcinoma. EBV sequences were detected in 22 of 138 (16%) cases of typical gastric adenocarcinoma by polymerase chain reaction and in situ hybridization (ISH) techniques. The EBV genomes were specifically present within the gastric carcinoma cells in an even distribution. The EBV genomes were also present in adjacent dysplastic epithelium but were absent in surrounding lymphocytes, other normal stromal cells, intestinal metaplasia, and normal gastric mucosa. The EBV genomes in the infected gastric carcinoma cells are expressed as EBV RNA was detected by ISH. EBV was most often detected in gastric tumors from men (21%) compared with women (3%). Thus some cases of gastric adenocarcinoma are EBV-associated. 相似文献
53.
The effects of electrical stimulation of ventral subiculum (VSB) of the hippocampus of the thermosensitive neurons in the preoptic area were studied in urethane-anesthetized rats. VSB stimulation affected thermosensitive neurons more frequently (92.1%, 58 of 63) than thermally insensitive neurons (71.4%, 55 of 77). The majority of the VSB-responsive thermosensitive neurons (33 of 44 warm-units and 11 of 14 cold-units) were initially inhibited following stimulation. The result provides further support for the involvement of hippocampus in the central control of thermoregulation. 相似文献
54.
Variable region sequences of pathogenic anti-mouse red blood cell autoantibodies from autoimmune NZB mice 总被引:4,自引:0,他引:4
L Reininger T Shibata S Ozaki T Shirai J C Jaton S Izui 《European journal of immunology》1990,20(4):771-777
New Zealand Black (NZB) mice spontaneously develop a severe autoimmune hemolytic anemia due to the production of anti-mouse red blood cell (MRBC) autoantibodies. The contribution of variable region genes and somatic mutations in the pathogenicity of anti-MRBC autoantibodies was investigated by mRNA sequencing of eight NZB anti-MRBC monoclonal autoantibodies, among which five are capable of inducing anemia in BALB/c mice. Here we report that at least three VH gene families (J558, J606 and 3609) and five Vchi subgroups (V chi 8, 9, 19, 21 and 28), in combination with several D, JH and Jchi gene segments, encode anti-MRBC autoantibodies. Thus, the NZB anti-MRBC autoantibodies, whether pathogenic or not, are encoded by a large number of immunoglobulin gene elements and by members of known VH and Vchi gene families with preferential usage of VH gene families most distal to the D regions. The presence of several mutations in the JH gene segments of both IgM and IgG anti-MRBC autoantibodies, whether pathogenic or not, strongly suggests that their VH regions may be highly mutated and that the mechanism of somatic diversification might be important in the generation of anti-MRBC autoantibodies. Our results support the idea that anti-MRBC autoimmune responses are likely to be generated by an antigen-driven mechanism. 相似文献
55.
56.
Toshio Nishikawa Takeshi Kasajima Akira Kajita Mitsunori Yamakawa Gengo Mabuchi Hideo Orihata Toshimitsu Shibata Makoto Nakazawa 《Pathology international》1988,38(5):683-691
A case of adrenocortical carcinoma associated with congenital heart defect in a 6-month-old Japanese girl is reported. A fist-sized tumor was incidentally noted in the right hypochondrium upon admission for cardiac surgery. No clinical endocrinopathy was evident in this case. The resected tumor was encapsulated with smooth surface and no invasion to adjacent tissues or organs was observed. Histologically, the tumor was composed of small cells with granular or clear cytoplasm, and occasional giant cells with single or multiple nuclei. By electron microscopy, the tumor cells showed various nuclear contours with distinct nucleoli and had a moderate amount of cytoplasm containing abundant rough endoplasmic reticulum and mitochondria with variable-sized electron-dense granules. Intercellular desmosome-llke junctions were observed in some tumor cells. Immunohistochemlcally, the tumor cells contained granules positive for estriol, progesterone and Cortisol. These morphological findings including electron microscopic features suggested that the tumor cells had a malignant character. 相似文献
57.
Takashi Kanno Yoichi Ohgushi Takeo Shibata 《Rinsho byori. The Japanese journal of clinical pathology》2008,56(7):622-626
We compared two sets of sex and age-specific reference intervals obtained from two large reference populations, one set calculated with data from 700,000 reference individuals by the nonlinear optimizing method of Ohgushi and Shibata and the other set calculated with data from 150,000 reference individuals from Shizuoka prefecture by the revised Hoffmann fitting method. Ten laboratory analytes used for health screening were compared. The sex- and age-specific reference intervals for total cholesterol, fasting blood sugar, uric acid, total protein, and albumin from the two large reference sample groups closely resembled each other, but reference intervals for the enzyme analytes aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and gamma-glutamyl transpeptidase only partly corresponded. Surprisingly, new information came from comparison of the sex- and age-specific reference intervals of alkaline phosphatase: low activities were observed in young females and higher activities were observed in older females. If a reference interval is used that does not take this observation into account, misdiagnosis of hyperthyroidism, which is frequently observed in young women, may result. Sex- and age-specific reference intervals should be used to interpret results of laboratory screening tests. 相似文献
58.
Y Ishimaru Y Shibata S Ohkawara H Ohshima S Kihara 《American journal of clinical pathology》1989,92(6):808-813
The authors report here a case of lymphoepithelial cystic lesion (LECL) of unknown origin in the mediastinum, which is closely related to a signet-ring cell adenocarcinoma. A 73-year-old man presented with a mass as revealed on a chest x-ray. During surgical operation, a solid, well-circumscribed and encapsulated 9 X 9 X 8 cm tumor was isolated from the right anterior mediastinum. This tumor had neither undergone metastasis nor invaded into the surrounding tissue and lymph nodes. Light microscopy revealed the tumor to be a signet-ring cell adenocarcinoma. Clinically, the neoplasm was coupled with an elevation in serum CEA level, which promptly returned to normal values following surgical removal. Immunohistochemistry pointed out that the majority of neoplastic cells stained positive for CEA. In addition, LECL of unknown origin was distinguished at the periphery of the tumor. LECL was characterized by microcysts which were lined by columnar epithelial and surrounded by lymphoid tissue with germinal centers. Transition between the neoplastic cells and benign epithelial cells of LECL was evident, showing that the previously mentioned mediastinal adenocarcinoma may be derived from the epithelial elements of LECL. This paper discusses the histogenesis of LECL. 相似文献
59.
Generators of visual evoked potentials for faces and eyes in the human brain as determined by dipole localization 总被引:4,自引:0,他引:4
Human visual evoked potentials were recorded during presentation of photos of human and animal faces and various face features. Negative waves with approximate peak latencies of 165 msec (N170) were bilaterally recorded from the occipito-temporal regions. Mean peak latencies of the N170 were shorter for faces than eyes only. Analyses of amplitudes of evoked potentials indicated that the N170 elicited by faces reflected activity of a specific neural system which was insensitive to detailed differences among individual faces regardless of species, and consequently suggest that this system might function to detect existence of faces in general. On the other hand, the mean amplitude of the N170 elicited by human eyes was significantly larger than those by animal eyes. These differences in response latencies and amplitudes of the N170 suggest existence of at least 2 different visual evoked potentials with similar latencies (i.e., N170) which are sensitive to faces in general and human eyes, respectively. Dipole source localization analysis indicated that dipoles for the N170 elicited by eyes were located in the posterior inferior temporal gyrus, and those for faces, located initially in the same region, but moved toward the fusiform and lingual gyri at the late phase of the N170. The results indicated that information processing of faces and eyes separated at least as early as the latency of the N170 at the posterior inferior temporal gyrus as well as the fusiform and lingual gyri, and might provide neurophysiological and anatomical bases to an initial structural encoding stage of human faces. 相似文献
60.
Mitsuyasu H Hirata N Sakai Y Shibata H Takeda Y Ninomiya H Kawasaki H Tashiro N Fukumaki Y 《Journal of human genetics》2001,46(1):26-31
The human dopamine D4 receptor (DRD4) is of major interest in molecular studies of schizophrenia and personality traits.
We examined the association of schizophrenia and polymorphisms in the upstream region of the DRD4 gene (−768G>A in the negative modulator region; −521C>T, −376C>T, and −291C>T in the cell type-specific promoter region;
and −616C>G between the two regions) in 208 schizophrenic patients and 210 normal controls. No significant difference in genotype
and allele frequencies was observed between the two groups, indicating that these polymorphisms do not make a major contribution
to the pathogenesis of schizophrenia. We also studied the association of polymorphisms in the upstream region and a 48-bp
repeat polymorphism in exon III of the DRD4 gene with personality traits in 173 Japanese individuals who completed the temperament and character inventory (TCI). The
−768G>A polymorphism was significantly associated with reward dependence (P = 0.044), while no significant association was observed between novelty seeking and polymorphisms in the upstream region
or the exon III repeat polymorphism of the DRD4 gene.
Received: August 28, 2000 / Accepted: October 25, 2000 相似文献