全文获取类型
收费全文 | 12884篇 |
免费 | 571篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 242篇 |
妇产科学 | 149篇 |
基础医学 | 1836篇 |
口腔科学 | 279篇 |
临床医学 | 796篇 |
内科学 | 3427篇 |
皮肤病学 | 204篇 |
神经病学 | 1028篇 |
特种医学 | 696篇 |
外科学 | 1801篇 |
综合类 | 32篇 |
一般理论 | 1篇 |
预防医学 | 368篇 |
眼科学 | 148篇 |
药学 | 1027篇 |
中国医学 | 38篇 |
肿瘤学 | 1381篇 |
出版年
2023年 | 46篇 |
2022年 | 88篇 |
2021年 | 143篇 |
2020年 | 72篇 |
2019年 | 86篇 |
2018年 | 121篇 |
2017年 | 98篇 |
2016年 | 157篇 |
2015年 | 167篇 |
2014年 | 204篇 |
2013年 | 247篇 |
2012年 | 498篇 |
2011年 | 503篇 |
2010年 | 342篇 |
2009年 | 297篇 |
2008年 | 540篇 |
2007年 | 642篇 |
2006年 | 608篇 |
2005年 | 690篇 |
2004年 | 715篇 |
2003年 | 702篇 |
2002年 | 763篇 |
2001年 | 526篇 |
2000年 | 549篇 |
1999年 | 475篇 |
1998年 | 238篇 |
1997年 | 175篇 |
1996年 | 177篇 |
1995年 | 150篇 |
1994年 | 128篇 |
1993年 | 122篇 |
1992年 | 402篇 |
1991年 | 326篇 |
1990年 | 296篇 |
1989年 | 349篇 |
1988年 | 280篇 |
1987年 | 308篇 |
1986年 | 230篇 |
1985年 | 190篇 |
1984年 | 171篇 |
1983年 | 111篇 |
1982年 | 84篇 |
1981年 | 66篇 |
1980年 | 50篇 |
1979年 | 98篇 |
1978年 | 61篇 |
1977年 | 64篇 |
1976年 | 43篇 |
1975年 | 23篇 |
1968年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Koh Nakazawa Nobuo Itoh Hui-Jun Duan Yuichi Komiyama Hidekazu Shigematsu 《Pathology international》1992,42(9):662-666
A 73-year-old Japanese man with a history of partial gastrectomy due to gastric cancer 4 years previously was admitted because of intermittent fever. The patient developed abdominal pain, erythema, and myalgia in addition to the fever during the final clinical course, and died of acute heart failure. Autopsy disclosed atrophy of the left lobe of the liver and acute myocardial infarction. Neither metastasis nor recurrence of the cancer was observed. Small and medium-sized arteries of the visceral organs showed various stages of necrotizing vasculitis with narrowing of the lumina. The vasculitis was most prominent in the left lobe of the liver and in the heart. Narrowing of the portal vein due to portal tract inflammation in addition to vasculitis of the hepatic arteries may have induced ischemia and infarction, which had resulted in atrophy of the left hepatic lobe. Acta Pathol Jpn 42: 662–666, 1992. 相似文献
92.
Ultrastructural,immunohistochemical and biochemical studies on amylase and ACTH producing lung cancer 总被引:1,自引:0,他引:1
Yutaka Yoshida Michio Mori Tomoko Sonoda Fumio Sakauchi Hiroyuki Sugawara Akira Suzuki 《Virchows Archiv : an international journal of pathology》1985,408(2-3):163-172
Summary Tumour tissue from a lung cancer patient who showed elevated serum amylase and adrenocorticotropin (ACTH) was studied ultrastructurally, immunohistochemically and biochemically. Histologically the tumour was a small cell carcinoma. On electron microscopic examination the tumour cells contained large zymogen-like granules within the cytoplasm. Furthermore, cells which possessed many small dense core granules of the endocrine type were also observed. It was of interest that the large zymogen-like granule-containing tumour cells had microvilli at the apical border, connected by desmosomes and forming lumina showing adenocarcinomatous differentiation. Electrophoretic analysis of the serum revealed that the major elevated amylase was of the salivary type with minor components. Immunostaining clearly demonstrated that most of the tumour cells possessed immunoreactive ACTH, whereas salivary amylase was only found in occasional clusters of the tumour cells. The results seem to indicate that the tumour showed both endocrine and exocrine characteristics - an amphicrine carcinoma, expressing amylase and ACTH simultaneously. 相似文献
93.
Mianserin (5-20 mg/kg), like chlordiazepoxide (2.5-10 mg/kg), inhibits the shock-induced suppression of drinking (SSD) in rats. However, in contrast to chlordiazepoxide, the effect of mianserin is not blocked by the benzodiazepine antagonist, Ro 15-1788 (10 mg/kg). Although mianserin does not inhibit [3H]diazepam binding in vitro it has now been found to enhance [3H]flunitrazepam binding to mouse whole brain in vivo at 10-100 mg/kg p.o. These results suggest that mianserin does influence central benzodiazepine receptors, but the mechanism by which it does so differs from that of chlordiazepoxide. 相似文献
94.
Pathogenesis of Rinderpest Virus Infection in Rabbits II. Effect of Rinderpest Virus on the Immune Functions of Rabbits
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kazuya Yamanouchi Akiko Fukuda Fumio Kobune Yasuhiro Yoshikawa Fumitoshi Chino 《Infection and immunity》1974,9(2):206-211
Rinderpest virus infection was shown to induce marked suppression of both humoral antibody response and cell-mediated immunity in rabbits. The virus exhibited a suppressive effect on primary antibody response as indicated by a decrease in numbers of plaque-forming cells (immunoglobulin [Ig]M) and hemagglutinating antibody titers of both IgM and IgG types to sheep red blood cells, whereas there was no detectable effect of the virus on the production of memory cells. Virus-induced suppression of cell-mediated immunity was demonstrated by a decreased rate of proliferative response of peripheral lymphocytes to phytohemagglutinin stimulus and by a depression of delayed-type skin reactions to purified protein derivative. Such suppressive effects were indicated to persist for 14 days or longer. Alteration in phagocytic activity of the reticuloendothelial system was not observed. The relevance of the virus-induced histological lesions in the lymphoid tissues to the virus-induced immunosuppression was discussed. 相似文献
95.
Thalamic projections to the putamen (Put) in the cat were studied by the retrograde horseradish peroxidase method. Major thalamic projections to the Put originate from the midline and intralaminar nuclear regions including the centre médian-parafascicular complex (CM-Pf). The other thalamic projections to the Put arise mainly from the suprageniculate nucleus (Sg), magnocellular division of the medial geniculate nucleus (MGm), caudomedial part of the lateroposterior nucleus (LP) and ventrolateral part of the ventromedial nucleus (VM). The VM projects to the rostral Put, while the posterior thalamic regions (Sg, MGm, LP) project to the caudal Put. 相似文献
96.
Enzyme-linked immunosorbent assay (ELISA) for detecting antisperm antibodies in mice with testicular autoimmunity 总被引:1,自引:0,他引:1
M Itoh C Hiramine M Koseto K Hojo 《American journal of reproductive immunology (New York, N.Y. : 1989)》1989,21(1):9-15
We developed an ELISA for measuring antisperm antibodies in the mouse by using serum samples obtained from mice immunized with murine testicular antigens in complete Freund's adjuvant (CFA) as well as from mice rendered vasectomized. Sperm antigens used were syngeneic epididymal spermatozoa and two types of soluble, murine testicular antigens prepared in our laboratory. This study deals with a) the sequential changes of antisperm antibody levels following immunization; b) determination of immunoglobulin classes of these antibodies; c) a correlation between the absorbance values and the endpoint titers of antisperm antibodies; and d) comparison of endpoint titers of antisperm antibodies detected by ELISA with those by immunoperoxidase staining method in immune and nonimmune sera. It is suggested that serum dilution as high as 1/800 or more is required for detecting antibody titers of immune sera, because nonimmune mouse sera reveal a definite, although low, level of absorbance value at a serum dilution of 1/400 or less. 相似文献
97.
Terao K Nagasawa N Nishida H Furusawa K Mori Y Yoshii F Dobashi T 《Journal of biomaterials science. Polymer edition》2003,14(11):1197-1208
In order to obtain a gelatin hydrogel crosslinked by a reagent-free method, gamma-ray and electron beam radiation was applied to porcine, bovine and fish gelatin gels and the products were characterized by measuring the gel fraction, the swelling ratio and the enzymatic degradability. On increasing the radiation dose, the gel fraction increased and both the swelling ratio and the enzymatic degradability decreased. The transition temperature from gel to sol of the hydrogel containing more than 5% mammal gelatins increased up to more than 90 degrees C when gamma-ray or electron beam were irradiated by more than 10 kGy. The results show that the degree of crosslinking of irradiated gelatin hydrogels increases with increasing irradiation dose and with decreasing concentration. It is suggested that the radiation crosslinking occurs around the physical crosslinking point or multiple helix structure of gelatin gel. 相似文献
98.
Hiroshi Kunikane Hiroshi Ishikura Jun Yamaguchi Takashi Yoshiki Tetsuo Itoh Miki Aizawa 《Pathology international》1987,37(4):615-625
The clinicopathology of 13 cases of chondroid syringoma were examined. The ages of the patients ranged from 26 to 86 years, with an average of 48 years. There were eight males and five females. Ten tumors out of the thirteen appeared on the face. Only one patient out of ten was suspected of recurrence in follow-up information. Histologically, all tumors consisted of epithelial cells, chondroid or myxoid matrix, and other strumal elements. The tumors were histologically classified into two types; twelve tumors had tubular and cystic lumina lined by two layers of epithelial cells, and only one case had small lumina lined by only a single layer. By an immunohistochemical study with a PAP method, positive stainings of keratin were observed in all cases, and S-100 protein in all but one. Ultrastructurally, the tumor cells showed features of an epithelial cell. Some ultrastructural differences were noted between two types of chondroid syringoma. Type I tumor cells had many tonofilaments in cytoplasm, but cytoplasmic filaments in type II were of the intermediate-type. 相似文献
99.
K Terashima K Takahashi M Kojima Y Imai S Tsuchida S Migita S Ebina C Itoh 《Acta pathologica japonica》1978,28(1):111-138
An autopsy case of systemic histiocytosis with excessive deposition of kappa-type light chain crystals was reported in a 58 year-old man who had consistently showed kappa-type light chain paraproteinemia, Bence Jones proteinuria and hypogammaglobulinemia for about 10 years until his death. However, no bony destruction was found by repeated X-ray examinations. At autopsy, extensive hyperplasia of crystal-storing histiocytes was observed in the bone marrow, spleen, liver, lymph nodes, interstitial tissues of visceral organs and loose connective tissues. In the bone marrow and some other tissues, mild proliferation of plasmocytoid cells containing small crystals were found. Histochemically the crystals positively stained with various methods for amino acids and proteins, especially with Weigerts' method for fibrin. Ultrastructurally intralysosomal crystal deposition was confirmed in the storage histiocytes and derivation of the crystals from Golgi's sacculi in the plasmocytoid cells was suggested. Biochemically the crystals were regarded as mainly consisting of dimers of a variable half of light chain immunoglobulin and immunochemically and immunohistochemically reacted to anti-kappa type light chain serum. Such a generalized storage histiocytosis may be secondarily induced by immunoglobulin synthesized in plasmocytoid cells. 相似文献
100.
Polo-like kinase 1 expression in medullary carcinoma of the thyroid: its relationship with clinicopathological features. 总被引:3,自引:0,他引:3
Yasuhiro Ito Yasushi Nakamura Hiroshi Yoshida Chisato Tomoda Takashi Uruno Yuuki Takamura Akihiro Miya Kaoru Kobayashi Fumio Matsuzuka Kanji Kuma Kennichi Kakudo Akira Miyauchi 《Pathobiology》2005,72(4):186-190
OBJECTIVE: Polo-like kinase 1 (PLK1) is one of the serine-threonine kinases that contributes to cell mitosis and is regarded as a marker of cellular proliferation. However, its protein expression in human carcinoma has not been studied in depth. In this study, we investigated PLK1 expression in medullary thyroid carcinoma by means of immunohistochemistry. METHODS: We immunohistochemically investigated PLK1 expression in 67 cases of medullary thyroid carcinoma. RESULTS: The PLK1 expression level was elevated in 43 of the 67 cases (64.1%). Furthermore, the expression level was directly linked to lymph node metastasis, advanced stage and male sex. All patients who were negative for PLK1 expression are currently alive without tumor recurrence, while 6 of the 43 PLK1-positive patients showed recurrence and 3 have already died of this disease. CONCLUSIONS: These findings suggest that PLK1 expression significantly reflects aggressive characteristics of medullary thyroid carcinoma. 相似文献