全文获取类型
收费全文 | 4889篇 |
免费 | 301篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 140篇 |
妇产科学 | 66篇 |
基础医学 | 788篇 |
口腔科学 | 96篇 |
临床医学 | 370篇 |
内科学 | 1212篇 |
皮肤病学 | 189篇 |
神经病学 | 399篇 |
特种医学 | 120篇 |
外科学 | 519篇 |
综合类 | 16篇 |
预防医学 | 215篇 |
眼科学 | 96篇 |
药学 | 422篇 |
中国医学 | 10篇 |
肿瘤学 | 521篇 |
出版年
2023年 | 37篇 |
2022年 | 57篇 |
2021年 | 118篇 |
2020年 | 68篇 |
2019年 | 104篇 |
2018年 | 127篇 |
2017年 | 108篇 |
2016年 | 127篇 |
2015年 | 126篇 |
2014年 | 145篇 |
2013年 | 191篇 |
2012年 | 299篇 |
2011年 | 330篇 |
2010年 | 174篇 |
2009年 | 179篇 |
2008年 | 320篇 |
2007年 | 307篇 |
2006年 | 308篇 |
2005年 | 310篇 |
2004年 | 332篇 |
2003年 | 314篇 |
2002年 | 300篇 |
2001年 | 80篇 |
2000年 | 51篇 |
1999年 | 59篇 |
1998年 | 47篇 |
1997年 | 56篇 |
1996年 | 39篇 |
1995年 | 39篇 |
1994年 | 41篇 |
1993年 | 33篇 |
1992年 | 47篇 |
1991年 | 50篇 |
1990年 | 38篇 |
1989年 | 31篇 |
1988年 | 42篇 |
1987年 | 20篇 |
1986年 | 31篇 |
1985年 | 28篇 |
1984年 | 14篇 |
1983年 | 16篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1977年 | 4篇 |
1973年 | 6篇 |
1971年 | 4篇 |
1969年 | 7篇 |
1960年 | 3篇 |
排序方式: 共有5219条查询结果,搜索用时 46 毫秒
51.
YMDD mutants in patients with chronic hepatitis B before treatment are not selected by lamivudine 总被引:2,自引:0,他引:2
52.
Possible role of vascular endothelial cells in immune responses in colonic mucosa examined immunocytochemically in subjects with and without ulcerative colitis 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
T Matsumoto A Kitano S Nakamura N Oshitani A Obata M Hiki H Hashimura K Okawa K Kobayashi H Nagura 《Clinical and experimental immunology》1989,78(3):424-430
Phenotypic characteristics of vascular endothelial cells of the colonic mucosa in patients with ulcerative colitis and healthy controls were studied with immunoperoxidase staining by light and electron microscopy. The cells could be classified into two groups according to their phenotypes; one was positive for von Willebrand factor and the other had an antigen detected by a monoclonal antibody, OKM5. The endothelial cells positive for von Willebrand factor were usually in relatively large blood vessels, and OKM5-positive cells were mostly located in small capillaries along the glandular epithelium. OKM5-positive endothelial cells also expressed HLA-DR and interleukin-1 (IL-1). In patients with ulcerative colitis, OKM5-positive endothelial cells and spindle-shaped cells that might be precursors of endothelial cells were more numerous in the lamina propria than in the other subjects. Thus, OKM5-positive endothelial cells may be important as antigen-presenting cells and immunoregulatory cells in the intramucosal immune system. Furthermore, colonic epithelial cells in patients with ulcerative colitis synthesized HLA-DR and IL-1, and may have a close relation to immune responses, such as antigen processing and presentation to immunocompetent cells. It was suggested that these cells have a close relation to the pathogenesis of the impaired immune responses in situ in ulcerative colitis. 相似文献
53.
Junko Watanabe Masami Taniguchi Kiyoshi Takahashi Takemasa Nakagawa Yukihiro Ooya Akira Akazawa Kazuo Akiyama 《Arerugī》2006,55(11):1421-1428
PURPOSE: To enable international comparison of prevalence in asthma, we translated and evaluated ECRHS Questionnaire, which is introduced in GINA. Considering COPD prevalence in elder people, we added two questions to the ECRHS Questionnaire. METHOD: The Japanese edition of ECRHS Questionnaire was responded by 366 patients who were diagnosed asthma without COPD, 61 patients who were diagnosed COPD without asthma, and 137 healthy persons who were not diagnosed asthma or COPD. We analyzed the answers of the each group and evaluated the validity of the questionnaire to use for the nation-wide prevalence study of adult asthma in future. RESULTS: The question of 'Wheezing at any time in the last 12 months' had the highest Youden's index and validity to pick up asthma patients. The questions of 'Waking up with a feeling of tightness in chest at any time in the last 12 months' and 'Waking up by an attack of shortness of breath at any time in the last 12 month' had the highest specificity to pick up asthma patients. Most of the questions which were related asthma were able to be answered by asthma patients properly, but some questions were improperly answered by patients and healthy persons in elderly. The results in this study showed the less recognition of their diseases in elderly patients than younger patients and the limitation of the study with written questionnaire for elderly people. Not a few COPD patients complained wheezing or whistling in the chests as same as asthma patients in this study. CONCLUSION: We concluded that we had almost enough reliability in the Japanese edition of the ECRHS questionnaire for screening survey of asthma prevalence in Japan. 相似文献
54.
Saiki O Uda H Nishimoto N Miwa T Mima T Ogawara T Azuma N Katada Y Sawaki J Tsutsui H Matsui K Maeda A Nakanishi K 《Clinical immunology (Orlando, Fla.)》2004,112(1):120-125
Adult Still's disease (ASD) is a chronic multisystemic disease. Extraordinarily high serum levels of IL-18 in ASD patients have been described, whereas the mechanism remains to be clarified. This study aimed to evaluate proinflammatory cytokines and to consider their pathological roles. In patients with rheumatic diseases (n = 151), blood samples were taken at the active phase and the serum levels of IL-18 and other proinflammatory cytokines were measured by ELISA. The extra-high levels of IL-18 were confirmed selectively in ASD patients (n = 10). In the active phase of ASD patients, the levels of IL-6 were elevated accordingly, but IL-1beta and TNF-alpha were undetectable. As to Th1-Th2 cytokines, the levels of IL-4 and IL-13, but not INF-gamma, IL-12, or IL-2, were elevated in all ASD patients examined. Moreover, the serum levels of IL-18 showed a good correlation with those of IL-4, suggesting that ASD reflects a Th2 rather than a Th1 cytokine profile. 相似文献
55.
Masaru Kishida Hiroki Nakazono Rei Kuroiwa Hidenori Dokai Junko Nakazato Hiroaki Nakamura Itsuo Suzuki Noriaki Shinomiya 《Arerugī》2007,56(11):1372-1377
BACKGROUND: Relationship between post administrative changes in plasma drug levels and bronchodilation remains unknown. In this study, we measured plasma levels of procaterol, a beta2-agonist, when being inhaled through nebulizers in children with bronchial asthma to examine relationship between improvement of pulmonary function and the plasma levels. METHOD: Six asthmatic children with the mean age of 9.8 years, inhaled 0.3 ml of 0.01% procaterol solution through a nebulizer. We examined changes in pulmonary function and plasma procaterol levels before and after inhalation. RESULTS: Procaterol was detected in the plasma 2 minutes after inhalation when it already rose to the maximum level, and kept the steady until showing a decline in 30 minutes. The measured highest value was 87.8+/-45.1 pg/ml. FEV 1.0 remarkably increased 2 minutes after inhalation and was maintained until 60 minutes after inhalation. Other lung function parameters also improved. There was no significant change in the heart rate, but serum potassium concentrations significantly dropped in all patients 60 minutes after inhalation. CONCLUSION: Plasma procaterol levels promptly rose to the peak at 2 minutes after inhalation and decreased 30 minutes later. Improvement of pulmonary function started promptly at minutes after inhalation and it became a peak 60 minutes later. 相似文献
56.
We previously reported that ammonia induced apoptosis in cultured rat hippocampal neurons with moderate increases in the intracellular calcium concentration and decreases in phospho-BAD levels. Since this suggested the involvement of calcineurin in the apoptosis, the effects of calcineurin inhibitors, 1 microM cyclosporin A and 1 microM FK506, on the ammonia-induced neuronal apoptosis were tested. Both of the inhibitors abolished the neuronal apoptosis assessed by double staining with Hoechst 33258 and anti-neurofilament antibody, and the ammonia-induced decrease in phospho-BAD Ser(155) level. Thus, calcineurin appeared to be involved in the dephosphorylation of BAD at the sites including Ser(155) in ammonia-induced apoptosis. 相似文献
57.
Immunohistochemical localization of 3β-hydroxysteroid dehydrogenase/Δ5→4-isomerase (3β-HSD), which converts Δ5-3β-hydroxysteroids to Δ4-3-ketosteroids, was performed in the human adrenal gland and in its disorders by employing a specific antibody raised against
the enzyme purified from human placenta. Immunoreactivity of 3β-HSD was present in all three cortical zones of the adrenal
glands obtained at autopsy, while in surgically removed adrenal glands, immunoreactivity was dominant in the zona fasciculata
(ZF), with faint immunoreactivity in the zona glomerulosa (ZG) and the zona reticularis (ZR). Intracortical localization of
3β-HSD in the adrenal glands obtained at autopsy may represent an adrenal adaptation to antemortem stress, with shifting of
adrenal pregnenolone- a substrate of 3β-HSD - as well as steroid 17α-hydroxylase from adrenal androgen synthesis to glucocorticoid
synthesis. In adrenocortical hyperplasia, marked immunoreactivity was observed in the ZG and outer ZF in adrenal glands with
idiopathic hyperaldosteronism and in the ZF and ZR, especially in cortical micronodules, in the adrenal glands associated
with Cushing’s disease. In aldosteronoma and Cushing’s adenoma, immunoreactivity of the enzyme was much more intense in large
clear tumor cells than in small compact tumor cells. Immunolocalization of 3β-HSD can yield important information toward an
understanding of adrenal steroid metabolism in both physiological and pathological processes. 相似文献
58.
Hlronobu Sasano Fumiko Date Hironao Yamamoto Hiroshi Nagura 《Pathology international》1997,47(9):647-650
A case of anglomyofibroblastoma of the vulva in a 49-year-old woman was examined. The tumor measured 3×2.5×2 cm and appeared light gray to tan In color on the cut surface. Light microscopic examinations revealed that spindle or oval shaped tumor cells were arranged in loose edematous stroma with numerous thin-walled vessels. Ultrastructurally, cell organellae were not well developed but intracytoplasmic filaments of intermediate size were abundant in the tumor cells. Desmin, CD34 and vimentin immunoreactivity were detected in almost all of the tumor cells. Both estrogen and progesterone receptors were diffusely expressed In the tumor, suggestive of the sex sterold-dependency of this tumor. The Ki-67 labeling index was less than 1% and the DNA content of the tumor cells, which was examined by image cytometry, demonstrated diploidy (DNA index=0.97). These findings may reflect the quiescent or slow growing features of angiomyofibroblastoma. 相似文献
59.
Multipotent, self-renewing stem and progenitor cells isolated from the mammalian central nervous system (CNS) have been shown to survive as allografts following transplantation to sites throughout the neuraxis. However, studies of this type shed little light upon the immunologic properties of the cells themselves, primarily because little is learned about the intrinsic immunogenic properties of a cell when it is grafted into an immune-privileged site. We have therefore investigated the immunogenic and antigenic properties of CNS progenitor cells by grafting them into a conventional (i.e., non-immune-privileged) site, namely, beneath the kidney capsule. Our results indicate that allogeneic CNS progenitor cells survive at least 4 weeks in a conventional site, during which time they neither sensitize their hosts nor express detectable levels of major histocompatibility complex (MHC) class I or II. These in vivo data are in accord with flow cytometric results showing that CNS progenitor cells do not express MHC class I or class II, either at baseline or upon differentiation in 10% serum. Exposure to interferon gamma, however, reversibly upregulates expression of these key transplantation antigens. Together, these results reveal CNS progenitor cells to possess inherent immune privilege. Since CNS progenitor cell allografts were rejected beneath the kidney capsule following specific sensitization of the host, CNS progenitor cells were able to display alloantigens, albeit not in an immunogenic form. 相似文献
60.