全文获取类型
收费全文 | 5783篇 |
免费 | 309篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 136篇 |
妇产科学 | 87篇 |
基础医学 | 799篇 |
口腔科学 | 92篇 |
临床医学 | 461篇 |
内科学 | 1575篇 |
皮肤病学 | 111篇 |
神经病学 | 320篇 |
特种医学 | 225篇 |
外科学 | 819篇 |
综合类 | 44篇 |
预防医学 | 200篇 |
眼科学 | 78篇 |
药学 | 401篇 |
中国医学 | 9篇 |
肿瘤学 | 675篇 |
出版年
2023年 | 34篇 |
2022年 | 52篇 |
2021年 | 139篇 |
2020年 | 56篇 |
2019年 | 64篇 |
2018年 | 78篇 |
2017年 | 69篇 |
2016年 | 73篇 |
2015年 | 82篇 |
2014年 | 105篇 |
2013年 | 155篇 |
2012年 | 245篇 |
2011年 | 261篇 |
2010年 | 149篇 |
2009年 | 151篇 |
2008年 | 246篇 |
2007年 | 297篇 |
2006年 | 282篇 |
2005年 | 274篇 |
2004年 | 255篇 |
2003年 | 219篇 |
2002年 | 254篇 |
2001年 | 187篇 |
2000年 | 213篇 |
1999年 | 214篇 |
1998年 | 83篇 |
1997年 | 88篇 |
1996年 | 73篇 |
1995年 | 54篇 |
1994年 | 41篇 |
1993年 | 34篇 |
1992年 | 149篇 |
1991年 | 151篇 |
1990年 | 144篇 |
1989年 | 136篇 |
1988年 | 126篇 |
1987年 | 108篇 |
1986年 | 94篇 |
1985年 | 99篇 |
1984年 | 72篇 |
1983年 | 59篇 |
1981年 | 27篇 |
1979年 | 61篇 |
1978年 | 31篇 |
1977年 | 35篇 |
1976年 | 22篇 |
1974年 | 45篇 |
1971年 | 23篇 |
1969年 | 22篇 |
1968年 | 22篇 |
排序方式: 共有6108条查询结果,搜索用时 15 毫秒
51.
Dominant-Negative Rho, Rac, and Cdc42 Facilitate the Invasion Process of Vibrio parahaemolyticus into Caco-2 Cells 下载免费PDF全文
Yukihiro Akeda Toshio Kodama Takashige Kashimoto Vlademir Cantarelli Yasuhiko Horiguchi Kenichi Nagayama Tetsuya Iida Takeshi Honda 《Infection and immunity》2002,70(2):970-973
To clarify the invasive process of Vibrio parahaemolyticus, an invasion assay was performed using cells expressing dominant negative small GTPases of the Rho family. This assay showed that the dominant negative host phenotype facilitates bacterial invasion, suggesting that the mechanism of V. parahaemolyticus invasion differs from that reported for other invasive bacteria. 相似文献
52.
Coexpression of type I and type II human macrophage scavenger receptors in macrophages of various organs and foam cells in atherosclerotic lesions. 下载免费PDF全文
M. Naito H. Suzuki T. Mori A. Matsumoto T. Kodama K. Takahashi 《The American journal of pathology》1992,141(3):591-599
Macrophage scavenger receptors are trimeric membrane glycoproteins implicated in the pathologic deposition of cholesterol in arterial walls during atherogenesis. Two types of cDNAs for functional human receptors have been cloned, but their physiologic roles remain obscure. To study the expression of these receptors, the authors generated antibodies against scavenger receptor type-specific synthetic peptide. Immunohistochemical examination using these antibodies and other anti-human receptor antibodies shows that type I and type II receptor proteins can be detected in foam cells in various stages of atherosclerosis, most evidently in fatty streaks. Co-expression of the two types of receptor protein was also detected in macrophages of various organs. Both types of the protein were detected on the surface and the membrane of endosomes in macrophages. These results indicate that both type I and type II scavenger receptors are expressed and functionally active in physiologic and pathologic conditions. 相似文献
53.
Granulocytosis associated with malignant neoplasms: a clinicopathologic study and demonstration of colony-stimulating activity in tumor extracts 总被引:1,自引:0,他引:1
We studied seven cases of malignant neoplasms, taken from various sites in the body, that were associated with marked granulocytosis. The seven cases were characterized clinically by marked granulocytosis with mature neutrophils, nonspecific inflammatory signs, and a rapid and progressive fatal course of the disease. The elevation of granulocyte count generally paralleled the increase in tumor size. Postmortem examination revealed no evidence of extensive bone marrow metastases or significant suppuration in any case. The bone marrows showed varying degrees of granulocytic hyperplasia with or without a shift to the left in the maturation series. Erythroid cell hyperplasia was observed in some cases, and in one instance there was an increase in immature eosinophils. The spleen showed various degrees of infiltration by neutrophils, from minimal to extremely marked; some spleens had foci of extramedullary hemopoiesis. Colony-stimulating activity was demonstrated in tumor extracts from three of these cases and from the serum in another case. Thus, it is suggested that marked granulocytosis in these patients was caused, at least in part, by colony-stimulating factor produced by the neoplastic cells. 相似文献
54.
Tasdemir Murat; Tasdemir Isik; Kodama Hideya; Tanaka Toshinobu 《Human reproduction (Oxford, England)》1993,8(12):2102-2107
To evaluate the possible effect of pentoxifylline on the acrosomereaction (AR) and its correlation with in-vitro fertilization(IVF), sperm samples obtained from 51 patients who underwentIVF treatment were studied. Acrosome reactions were evaluatedas spontaneous, pentoxifylline-treated and calcium ionophore(A23187) induced, before and after treatment. The correlationof AR with fertilization in vitro in spermatozoa pre-treatedwith pentoxifylline was sought. In cases with failure or verylow fertilization rate (10%) in their previous trials, spermatozoaafter swim-up were treated before insemination. Spontaneousacrosome loss remained low even after treatment (mean ±SD: 8.18 ± 1.74%). Response to A23187 was enhanced significantly(P < 0.001) by pre-treatment with pentoxifylline in 33 controlcases (group A) in which fertilization in vitro was previouslysuccessful without this treatment. Patients with at least twoepisodes of failed fertilization were divided into two groups.In 11 cases (group B), the IVF rate was improved significantly(P < 0.001) by the treatment. This was not observed in sevencases (group C) in which the treatment induced no increase inIVF rate. We achieved nine (27.3%) pregnancies in group A andfive (45.4%) pregnancies in group B. This study demonstratedthat pentoxifylline enhanced A23187 induced the acrosome reactionand this effect was correlated with improvement in IVF rate. 相似文献
55.
56.
Evaluation of a Membrane Filter Assay System, Ortho HCV Ab Quik Pack, for Detection of Anti-Hepatitis C Virus Antibody 下载免费PDF全文
Takanari Kodama Satoshi Ichiyama Kumiko Sato Toshi Nada Nobuo Nakashima 《Journal of clinical microbiology》1998,36(5):1439-1440
A simple membrane immunoassay assay system, Quik Pack, for the detection of hepatitis C virus antibody was compared with two enzyme-linked immunosorbent assays (ELISAs) in a study of 600 serum samples. Quik Pack exhibited excellent sensitivity and specificity: 96.0 and 99.7%, respectively, versus the ELISA-2 and 99.7 and 99.4%, respectively, versus the ELISA-3. 相似文献
57.
IgAN is a common form of primary glomerulonephritis and also a disease of tonsillar focal infection. The comprehensive mechanism underlying this disease remains to be defined. To better understand its pathogenesis, we investigated tonsillar CD5+ B cells (B-1 cells) with respect to IgA synthesis. Germinal centre (GC) B cells were isolated from the tonsils of IgAN patients and the number of B-1 cells in the GC determined by flow cytometry. GC B-1 and B-2 (CD5- B) cells were purified by cell sorter, the cells were incubated with agonist anti-CD40 MoAb and the ability for antibody production by B-1 and B-2 cells determined by ELISPOT assay. GC B-1 cells and B-2 cells were incubated with agonist anti-Fas MoAb, and apoptosis in GC B-1 cells and B-2 cells was analysed by flow cytometry. Although B-1 cells do not usually take part in the GC reaction, an increase in B-1 cell numbers was observed in the GC of tonsils from IgAN patients. These B-1 cells were likely IgA1 antibody-producing cells, since the prominent IgA subclass in IgAN is generally considered to be IgA1. Although Fas-dependent apoptosis is essential for the elimination of activated B cells, these B-1 cells showed a reduced susceptibility to Fas-mediated apoptosis. It is conceivable that activated B-1 cells may survive in the GC due to impaired apoptosis and thus produce abnormal antibodies. These findings suggest that the immune responses of B-1 cells in the tonsillar GC could thus have an impact on the pathogenesis of IgAN. 相似文献
58.
Chronic active Epstein-Barr virus (EBV) infection has been recognized as clonal non-neoplastic lymphoproliferative diseases. However, some reports of cases with a multiphenotypic expansion of EBV-infected lymphocytes give rise to questions of how EBV infects multiphenotypic lymphocytes and whether chronic active EBV infection is a truly monoclonal lymphoproliferative disease. We report two patients with chronic active EBV infection who showed expansion of multiphenotypic EBV-infected lymphocytes. EBV DNA was detected in CD4+ and CD8+ T cells and in B cells from pleural fluid of one patient and in T and B cells from a cervical lymph node of the other patient by polymerase chain reaction (PCR). Although real-time PCR showed that there were equally high loads of EBV genomes in CD4+ and CD8+ T cells from the pleural fluid, Southern blot hybridization with terminal repeats of the EBV genome showed a single band of the same molecular weight in three tissue samples from the patient. The results indicated biphenotypic expansions of CD4+ and CD8+ T cells infected with the same clone of EBV. Furthermore, bisulfite PCR analysis showed hypermethylated status in the Cp region in the two patients regardless of their cell populations. There has been a discrepancy between clonality and expansion of multiphenotypic EBV-infected lymphocytes. We speculate that lymphoid progenitor cells that have not differentiated into T and B cell progenitors are infected with EBV, resulting in clonal expansion of EBV-infected multiphenotypic cells. 相似文献
59.
Temporal modification of amygdaloid serotonin (5HT) content and the resultant muricide behavior, compared to isolated and olfactory bulbectomized rats, were studied after chronic theophylline administration. Theophylline raised amygdaloid 5HT after Day 28 and amygdaloid 5-hydroxyindoleacetic acid (5HIAA), its deaminated metabolite, after Day 7. Theophylline applied for 29 days elevated 5HT and 5HIAA in the amygdala, the diencephalon and the brain stem, but not in the cortex. Effects of theophylline were reduced latency and maintained tendency to kill, even after overnight muricide test. The 5HT content of the amygdala decreased in bulbectomized rats. Discrepancy between brain 5HT changes and aggressive behavior were discussed. 相似文献
60.
Mitsuyo Nishimura Tetsuro Kodama Hiroyuki Nishiyama Yutaka Nishiwaki Tomoyuki Yokose Yukio Shimosato 《Pathology international》1997,47(4):260-263
A 57-year-old woman presented with a 10×10 cm anterior mediations mass. The tumor had Invaded the pericardium, both lungs and the left brachiocephallc vein, and was treated by partial resection and postoperative radiation therapy. Pathological examination of the tumor revealed squamous cell carcinoma with a spindle cell sarcomatous component. Immunohistochemically, keratin and epithelial membrane antlgen were posltive In both the spindle cell sarcomatous areas and the squamous cell carcinomatous area and thus, a diagnosis of thymic carcinoma of sarcomatoid type was made. The patient died of recurrent disease 1 year after surgery. This case is the seventh reported In the English literature Because of the poor outcome, adjuvant therapy is recommended. 相似文献