全文获取类型
收费全文 | 7283篇 |
免费 | 369篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 162篇 |
妇产科学 | 149篇 |
基础医学 | 958篇 |
口腔科学 | 260篇 |
临床医学 | 414篇 |
内科学 | 1657篇 |
皮肤病学 | 122篇 |
神经病学 | 514篇 |
特种医学 | 307篇 |
外科学 | 1179篇 |
综合类 | 49篇 |
预防医学 | 344篇 |
眼科学 | 255篇 |
药学 | 432篇 |
中国医学 | 7篇 |
肿瘤学 | 836篇 |
出版年
2023年 | 32篇 |
2022年 | 60篇 |
2021年 | 124篇 |
2020年 | 68篇 |
2019年 | 82篇 |
2018年 | 117篇 |
2017年 | 86篇 |
2016年 | 125篇 |
2015年 | 147篇 |
2014年 | 147篇 |
2013年 | 239篇 |
2012年 | 342篇 |
2011年 | 358篇 |
2010年 | 203篇 |
2009年 | 164篇 |
2008年 | 350篇 |
2007年 | 366篇 |
2006年 | 375篇 |
2005年 | 309篇 |
2004年 | 328篇 |
2003年 | 300篇 |
2002年 | 325篇 |
2001年 | 296篇 |
2000年 | 274篇 |
1999年 | 248篇 |
1998年 | 105篇 |
1997年 | 89篇 |
1996年 | 95篇 |
1995年 | 67篇 |
1994年 | 72篇 |
1993年 | 49篇 |
1992年 | 172篇 |
1991年 | 159篇 |
1990年 | 190篇 |
1989年 | 159篇 |
1988年 | 117篇 |
1987年 | 102篇 |
1986年 | 113篇 |
1985年 | 89篇 |
1984年 | 81篇 |
1983年 | 66篇 |
1982年 | 37篇 |
1979年 | 65篇 |
1978年 | 34篇 |
1977年 | 33篇 |
1976年 | 28篇 |
1975年 | 26篇 |
1972年 | 29篇 |
1971年 | 28篇 |
1970年 | 31篇 |
排序方式: 共有7692条查询结果,搜索用时 15 毫秒
61.
Clinical evaluation of 430 MHz microwave hyperthermia system with lens applicator for cancer therapy 总被引:2,自引:0,他引:2
M. Hiraoka Y. Nishimura S. -I. C. Masunaga M. Koishi M. Mitsumori Y. P. Li Y. Nagata K. Akuta M. Takahashi M. Abe 《Medical & biological engineering & computing》1995,33(1):44-47
The clinical efficacy of a microwave (MW) hyperthermia system using an electric-field converging (lens) applicator is evaluated
for 42 malignant tumours with a maximum tumour depth of less than 7 cm. The mean of the maximum, average and minimum tumour
temperature of the 42 tumours are 44,5, 42.5 and 40.7 C, respectively. The thermal parameters are higher for tumours in the
chest, abdominal walls and hip than for those in the neck, groin and extremities. No apparent difference in thermal parameters
according to the depth of tumour is shown. Of 40 tumours treated by hyperthermia in combination with radiotherapy, 20 (50%)
showed complete regression, 14 (35%) showed partial regression, and six (15%) showed no change. This phase I and II study
indicates clinical feasibility of the newly developed MW heating apparatus, and strongly suggests the usefulness of thermoradiotherapy
in the treatment of localised superficial and subsurface malignancies. 相似文献
62.
Sinuhe Hahn Thomas Stalder Marion Wernli Diana Bürgin Jürg Tschopp Shigekazu Nagata Peter Erb 《European journal of immunology》1995,25(9):2679-2685
Fas was recently demonstrated to be the major target molecule engaged by CD4+ cytolytic T lymphocytes (CTL). We examined Fas expression on various cloned T cell subpopulations and their susceptibility to lysis by CD4+ or CD8+ CTL. A reciprocal relationship in Fas and Fas-ligand expression was observed in CD4+ T helper (Th)1- and Th2-type clones, and Fas mRNA was predominantly detected in Th2 clones, whereas Fas-ligand mRNA was principally found in Th1 clones. The two Th0 clones tested expressed both Fas and Fas-ligand, but only one exhibited cytolytic activity, whereas both were sensitive to CD4-mediated lysis. A functional consequence of the inverse Fas-Fas-ligand expression pattern was that Th2 and Th0 cells were sensitive to lysis by both Th1 CD4+ CTL and a CD8+ CTL clone in a Fas-dependent manner. These results suggest that cytolytic CD4+ Th1 cells may play an immunomodulatory role, regulating a Th2/Th0 response by Fas-mediated lysis. 相似文献
63.
S. Oh-ishi Takako Kizaki Tomomi Ookawara Koji Toshinai Shukoh Haga Fujio Karasawa Tetsuo Satoh Naokazu Nagata L. L. Ji Hideki Ohno 《Pflügers Archiv : European journal of physiology》1998,435(6):767-774
The aim of the current study was to elucidate the synergism of dietary calcium restriction and exhaustive exercise in the
antioxidant enzyme system of rat soleus muscle, and to investigate the involvement of neutrophils in exercise-induced muscle
damage. Forty-eight male Wistar rats were assigned to the following groups: control (C) or calcium-restricted [1 month (1 M)
or 3 months (3 M)]. Each group was subdivided into acutely exercised or non-exercised groups. Soleus muscle from each rat
was analysed to determine the levels of antioxidant enzymes [Mn-superoxide dismutase (SOD), Cu,Zn-SOD, glutathione peroxidase
(GPX), and catalase (CAT)]. Dietary calcium restriction resulted in calcium deficiency and upregulated the antioxidant enzymes
examined except GPX. Conversely, exhaustive exercise significantly decreased GPX and CAT, but not SODs activities in the calcium-restricted
(1 M and/or 3 M) rats. Contents of immunoreactive Mn-SOD and Cu,Zn-SOD were only increased in the 3 M rats. During calcium
restriction, the mRNA expression of both forms of SOD showed initial upregulation, followed by downregulation. Exhaustive
exercise significantly increased the mRNA expressions only in the 3 M rats. Moreover, exhaustive exercise markedly increased
myeloperoxidase activity in soleus muscles from the 1 M and 3 M rats compared with the C rats, and significantly enhanced
the ability of neutrophils to generate superoxide in the 3 M rats. The results demonstrate that dietary calcium restriction
upregulates certain antioxidant enzyme activities in rat soleus muscle, indicating an enhanced resistance to potential increases
in intracellular reactive oxygen species. The results also suggest that exhaustive exercise may cause oxidative damage in
soleus muscle of calcium-deficient rats through the activation of neutrophils.
Received: 4 August 1997 / Received after revision: 29 September 1997 / Accepted: 26 November 1997 相似文献
64.
S. Nagata Y. Okamoto T. Inoue Y. Ueno T. Kurata J. Chiba 《Archives of virology》1992,127(1-4):153-168
Summary Thirteen monoclonal antibodies (MAbs) to the glycoprotein (G) of vesicular stomatitis virus (VSV) serotype Indiana were prepared and examined for their effects on various biological activities of VSV, including in vitro infection, hemagglutination, adsorption to cells, and mediation of cell fusion. Competitive binding assays with these MAbs revealed the presence of at least seven distinct antigenic determinants (epitopes) on the G protein. In some cases, overlappings among epitopes to various degrees were observed as partial inhibition or binding enhancement. The MAbs to all the epitopes but one (epitopes 1–6) reacted with the denatured G protein in a Western immunoblot analysis. Four of the epitopes (epitopes 2, 4, 5, and 7) were involved in neutralization and two (epitopes 1 and 2) in hemagglutination inhibition. None of the MAbs inhibited the adsorption of radiolabeled VSV to BHK-21 cells; the MAbs to epitope 2 slightly enhanced the virus adsorption. All neutralization epitopes except epitope 2 (epitopes 4, 5, and 7) were associated with inhibition of VSV-mediated cell fusion. These results show a direct spatial relationship between the epitopes recognized by the MAbs and functional sites on G protein and further insights into the structure and function of G protein. 相似文献
65.
I Matsuda N Nagata T Matsuura K Oyanagi K Tada K Narisawa T Kitagawa T Sakiyama F Yamashita M Yoshino 《American journal of medical genetics》1991,38(1):85-89
In a retrospective survey done from 1978-1988 in Japan, 32 male patients with ornithine transcarbamylase (OTC) deficiency were identified. We classified a neonatal and 2 late-onset groups, depending on clinical manifestations and the age at onset; group 1 (0-28 days; N = 10), group 2 (29 days-5 years; N = 13), and group 3 (greater than 5 years; N = 9). Compared to findings in the group 2 patients, there was a higher rate of mortality and a higher incidence of mental retardation in association with a great decrease in enzyme activity in group 1. In group 3, the mortality rate and enzyme activities were similar to those in group 1. However, patients in this group were asymptomatic prior to the first episode. Enzyme activities were measured mostly in autopsy samples. The serum citrulline levels (enzyme product) were highest in this group. Thus, the mutant enzymes were apparently labile with greater activities in vivo than in vitro. Treatments, including a protein-restricted diet, arginine supplementation, and sodium benzoate administration, resulted in a favorable prognosis for survivors with partial enzyme deficiency. We wish to emphasize that the incidence of late onset of this disease is higher than heretofore considered. 相似文献
66.
67.
68.
K Maruoka M Yamanaka M Misago K Nakata J Tsukada K Nagata T Sato N Mori S Oda S Chiba 《Rinsho byori. The Japanese journal of clinical pathology》1990,38(10):1161-1166
The activities of RNase (RNase-U and RNase-C) were determined in the serum and leukocytes of 277 patients with 14 cases of various kinds of eosinophilia (not less than 10(3)/microliters), 28 cases of chronic myelocytic leukemia (CML), using polyuridylic acid and polycytidylic acid as synthetic substrates according to the method of Raddi et al. Serum RNase-U activity, serum RNase-C activity and the activity ratio (U/C x 10(-3)) were 55 +/- 14 U, 1,280 +/- 235 U and 44 +/- 11 (mean +/- SD), 196 +/- 137, 1,992 +/- 1,134 U and 97 +/- 38, and 110 +/- 50 U, 1,854 +/- 625 U and 65 +/- 13 for normal subjects, eosinophilia and CML (untreated), respectively. U/C ratio in eosinophilia and CML (untreated) showed a highly significant positive correlation (p less than 0.001) with peripheral eosinophil count; the activity of serum RNase-U per cells in the supernatant of eosinophil homogenate rose significantly (p less than 0.001) compared with that of lymphocytes or granulocytes. Besides, serum and eosinophil RNase-U had a similar optimal pH. These results suggested that serum RNase-U in eosinophilia originated mostly from eosinophils and its rise was correlated strongly with the increase in eosinophils. 相似文献
69.
Motomaro Nakajima Hiroyuki Narnbu Nobuaki Shikata Hideto Senzaki Hirohiko Miki Airo Tsubura 《Pathology international》1996,46(11):874-882
Pigmentary degeneration of the retina was induced by a single intraperitoneal Injection of 75mgkg of N-methyl-N-nitrosourea (MNU) In female Brown-Norway colored rats at 50 days of age, which were then observed at 24, 48 and 72 h and 7, 21,35 and 150 days after the treatment. MNU-treated rats showed selective destruction of the photoreceptor cells by an apoptotic mechanlsm 24 h after the treatment, and the destruction was completed by day 7. During the photoreceptor cell degeneration, proliferation of Miller cells and infiltratlon of macrophages was prominent 72h and 21 days aRttr the treatment, respectively. Müller cell proliferation and macrophage infiltratbn corresponded to degenerative photo-receptor cell phagocytosis, and prollferating Müller cell processes responded to stabilize the damaged retina. Pigment epithelial cell detachment from the Bruch's membrane was seen 72 h after the treatment, and migration within all layers of the retina was seen at day 7 when photoreceptor Cells were lost. At 21, 35 and 150 days after the treatment, lack of photoreceptor cells and deposition of pigment epithelial cells within the retina but not in contact to vascular endothe-lial cells were characteristic. MNU-induced photoreceptor apoptosis followed by Miiller cell and macrophage reaction then pigment epithellal cells deposition withln the retina partially resembles retinitis pigmentosa in humans. 相似文献
70.
Increased lymphocyte trafficking to colonic microvessels is dependent on MAdCAM-1 and C-C chemokine mLARC/CCL20 in DSS-induced mice colitis 总被引:5,自引:0,他引:5
Teramoto K Miura S Tsuzuki Y Hokari R Watanabe C Inamura T Ogawa T Hosoe N Nagata H Ishii H Hibi T 《Clinical and experimental immunology》2005,139(3):421-428
Although enhanced lymphocyte trafficking is associated with colitis formation, little information about its regulation is available. The aim of this study was to examine how the murine liver and activation-regulated chemokine (mLARC/CCL20) contributes to lymphocyte recruitment in concert with vascular adhesion molecules in murine chronic experimental colitis. T and B lymphocytes isolated from the spleen were fluorescence-labelled and administered to recipient mice. Lymphocyte adhesion to microvessels of the colonic mucosa and submucosa was observed with an intravital microscope. To induce colitis, the mice received two cycles of treatment with 2% dextran sodium sulphate (DSS). In some of the experiments antibodies against the adhesion molecules or anti-mLARC/CCL20 were administered, or CC chemokine receptor 6 (CCR6) of the lymphocytes was desensitized with excess amounts of mLARC/CCL20. Significant increases in T and B cell adhesion to the microvessels of the DSS-treated mucosa and submucosa were observed. In chronic colitis, the accumulation of lymphocytes was significantly inhibited by anti-mucosal addressin cell adhesion molecule (MAdCAM)-1 mAb, but not by anti-vascular cell adhesion molecule-1. In DSS-treated colonic tissue, the expression of mLARC/CCL20 was significantly increased, the blocking of mLARC/CCL20 by monoclonal antibody or the desensitization of CCR6 with mLARC/CCL20 significantly attenuated the DSS-induced T and B cell accumulation. However, the combination of blocking CCR6 with MAdCAM-1 did not further inhibit these accumulations. These results suggest that in chronic DSS-induced colitis, both MAdCAM-1 and mLARC/CCL20 may play important roles in T and B lymphocyte adhesion in the inflamed colon under flow conditions. 相似文献