全文获取类型
收费全文 | 5844篇 |
免费 | 275篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 87篇 |
妇产科学 | 81篇 |
基础医学 | 639篇 |
口腔科学 | 67篇 |
临床医学 | 404篇 |
内科学 | 1711篇 |
皮肤病学 | 50篇 |
神经病学 | 417篇 |
特种医学 | 222篇 |
外科学 | 1103篇 |
综合类 | 20篇 |
一般理论 | 2篇 |
预防医学 | 130篇 |
眼科学 | 68篇 |
药学 | 523篇 |
中国医学 | 13篇 |
肿瘤学 | 584篇 |
出版年
2023年 | 35篇 |
2022年 | 78篇 |
2021年 | 87篇 |
2020年 | 52篇 |
2019年 | 82篇 |
2018年 | 88篇 |
2017年 | 63篇 |
2016年 | 117篇 |
2015年 | 111篇 |
2014年 | 156篇 |
2013年 | 155篇 |
2012年 | 245篇 |
2011年 | 288篇 |
2010年 | 169篇 |
2009年 | 157篇 |
2008年 | 282篇 |
2007年 | 275篇 |
2006年 | 266篇 |
2005年 | 259篇 |
2004年 | 241篇 |
2003年 | 258篇 |
2002年 | 251篇 |
2001年 | 220篇 |
2000年 | 225篇 |
1999年 | 211篇 |
1998年 | 60篇 |
1997年 | 42篇 |
1996年 | 36篇 |
1995年 | 33篇 |
1994年 | 43篇 |
1993年 | 21篇 |
1992年 | 143篇 |
1991年 | 148篇 |
1990年 | 155篇 |
1989年 | 176篇 |
1988年 | 126篇 |
1987年 | 134篇 |
1986年 | 110篇 |
1985年 | 113篇 |
1984年 | 69篇 |
1983年 | 48篇 |
1982年 | 22篇 |
1979年 | 38篇 |
1978年 | 28篇 |
1977年 | 19篇 |
1975年 | 18篇 |
1974年 | 24篇 |
1972年 | 29篇 |
1971年 | 23篇 |
1969年 | 20篇 |
排序方式: 共有6176条查询结果,搜索用时 0 毫秒
21.
Yoshiro Tanizaki Hikaru Kitani Takashi Mifune Fumihiro Mitsunobu Kazuhiro Kajimoto Keisuke Sugimoto 《The Journal of asthma》1993,30(6):485-492
The effects of glucocorticoids on the proportion of lymphocytes in bronchoalveolar lavage (BAL) fluid in relation to humoral and cellular immunity were studied in 56 patients with steroid-dependent intractable asthma. To analyze the mechanism responsible for reduced numbers of BAL lymphocytes, we divided the subjects into 4 groups according to their BAL lymphocyte proportions: 0—4.9%, 5.0-9.9%, 10.0-14.9%, and 15.0-20.0%. Serum IgG levels and the peripheral lymphocyte count were significantly reduced in patients with a low proportion of BAL lymphocytes (less than 9.9%) than in those with more than 10% BAL lymphocytes. Delayed cutaneous reactivity to purified protein derivative was suppressed in patients with a low proportion of BAL lymphocytes (less than 4.9%). The mean proportion of BAL neutrophils tended to increase as the proportion of BAL lymphocytes decreased. These results show that the reduction in BAL lymphocytes produced by glucocorticoids is associated with suppressed humoral and cellular immunity, and that under such conditions the proportion of BAL neutrophils increases. 相似文献
22.
Takeo Tabuchi Akira Okayama Yasutaka Ogawa Keiko Miyajima Mamoru Hirata Toshiaki Yoshida Kanji Sugimoto Kanehisa Morimot 《International archives of occupational and environmental health》1989,61(5):297-302
Summary A new sensitive HPLC method for the determination of urinary delta-aminolevulinic acid (ALA-U) was used to evaluate the relationship between blood-lead (Pb-B) and ALA-U levels in male workers exposed to lead. The differences between the ALA-U levels determined by this method (ALAU-HP) and by a colorimetric method (ALA-U-CL) are discussed. The HPLC method gave values similar to the ALA-U-CL values at high ALA-U level. However, at low blood-lead levels (58 ± 22 g/l, n = 23), the mean ALA-U-HP level corrected by urinary creatinine level was one-third of the corrected ALA-UCL level (0.83 ± 0.14 and 2.4 ± 0.5 mg/g creatinine, respectively). A significant increase of the mean corrected ALA-U-HP level was observed at 162 ± 22 g/l Pb-B (P < 0.05, n = 26), while that of ALA-UCL was observed at 245 ± 30 g/l Pb-B (P < 0.01, n = 37). The regression equation based on the logistic model fitted well to the relationship data between the Pb-B level and the percentage of the subjects with corrected ALA-U-HP above the cut-off point (1.12 mg/g creatinine) and the expected Pb-B level for 50% response was 270 g/l Pb-B, while it did not fit well to the relationship data between Pb-B level and the percentage of the subjects with corrected ALAU-CL above the cut-off point (3.5 mg/g creatinine). The maximum responses for the two sets of corrected ALA-U levels were both observed at 625 ± 25 g/l. The corrected ALA-U level by HPLC method seems to be a useful indicator for biological monitoring of exposure to lead at low levels (< 400 g/l Pb-B = health-based biological limit, WHO) as well as high ones. 相似文献
23.
Y. Hirata K. Fukui Y. Dan H. Matsuoka T. Sugimoto M. Ishii 《European journal of clinical pharmacology》1989,36(6):575-578
Summary The renal and hormonal effects of the 1-adrenoceptor blocker bunazosin were examined in 6 patients with essential hypertension. Oral bunazosin for 4 to 12 weeks significantly decreased mean blood pressure by 10%, increased effective renal blood flow and creatinine clearance by 34% and 37%, respectively, the plasma norepinephrine concentration was elevated by 60%, and the plasma atrial natriuretic peptide level was lowered by 22%. The plasma renin activity and aldosterone concentration were unchanged. Thus, a moderate reduction in blood pressure was produced by bunazosin treatment while maintaining renal perfusion. 相似文献
24.
Hiroyuki Ito Reiko Takikawa Yoshihisa Kurachi Tsuneaki Sugimoto 《Naunyn-Schmiedeberg's archives of pharmacology》1989,339(1-2):244-246
Summary Effects of verapamil on the acetylcholine (ACh)-induced K+ current were examined in single atrial cells, using the tight-seal whole-cell clamp technique. The pipette solution contained guanosine-5-triphosphate (GTP) or guanosine-5-O-(3-thiotriphosphate) (GTP-S, a non-hydrolysable GTP analogue). In GTP-loaded cells, ACh induced a specific K+ current, which is known to be mediated by pertussis toxin-sensitive GTP-binding (G) proteins. Verapamil (0.1–100 M) depressed the ACh-induced K+ current in a concentration-dependent fashion. In GTP-S-loaded cells, the K+ current remained persistently after wash-out of ACh, probably due to irreversible activation of G proteins by GTP-S. Verapamil (0.1–100 M) also depressed the intracellular GTP-S-induced K+ current. However, the magnitude of verapamil-depression of the K+ current in GTP-S-loaded cells was significantly smaller than that in GTP-loaded cells at concentrations between 1 and 10 M of the drug. From these results, it is suggested that verapamil may block not only the function of muscarinic ACh receptors but also of G proteins and/or the K+ channel itself and thereby depress the ACh-induced K+ current in isolated atrial myocytes.Supported by grants from the Ministry of Education, Science and Culture of Japan and the Research Program on Ca Signal Control
Send offprint requests to Y. Kurachi at the above address 相似文献
25.
Toyofuku T Yoshida J Sugimoto T Zhang H Kumanogoh A Hori M Kikutani H 《Nature neuroscience》2005,8(12):1712-1719
Sema3A, a prototypical semaphorin, acts as a chemorepellent or a chemoattractant for axons by activating a receptor complex comprising neuropilin-1 as the ligand-binding subunit and plexin-A1 as the signal-transducing subunit. How the signals downstream of plexin-A1 are triggered upon Sema3A stimulation, however, is unknown. Here we show that, in the presence of neuropilin-1, the FERM domain-containing guanine nucleotide exchange factor (GEF) FARP2 associates directly with plexin-A1. Sema3A binding to neuropilin-1 induces the dissociation of FARP2 from plexin-A1, resulting in activation of FARP2's Rac GEF activity, Rnd1 recruitment to plexin-A1, and downregulation of R-Ras. Simultaneously, the FERM domain of FARP2 sequesters phosphatidylinositol phosphate kinase type I isoform PIPKIgamma661 from talin, thereby inhibiting its kinase activity. These activities are required for Sema3A-mediated repulsion of outgrowing axons and suppression of neuronal adhesion. We therefore conclude that FARP2 is a key molecule involved in the response of neuronal growth cones to class-3 semaphorins. 相似文献
26.
27.
Misawa A Hosoi H Imoto I Iehara T Sugimoto T Inazawa J 《Journal of human genetics》2004,49(10):586-589
Malignant rhabdoid tumor (MRT) is a highly malignant pediatric cancer, which arises in various sites such as the kidney, brain, and soft tissues. Cytogenetic studies have revealed alterations of 22q11 in MRT. Recently, deletions and mutations of the SNF5/INI1 locus in 22q11.2 have been reported in MRT, suggesting that SNF5/INI1 is a tumor suppressor gene for MRT. Here we report our molecular cytogenetic study for a newly established cell line from extrarenal MRT with t(1;22)(p36;q11.2). Consequently, the reciprocal translocation was associated with the interstitial deletion of a small segment including SNF5/INI1, and another, chromosome 22, showed terminal deletion, the breakpoint of which was located 70–80 kb centromeric to SNF5/INI1, resulting in homozygous deletion of SNF5/INI1 in this cell line. 相似文献
28.
Parathyroid hormone related peptide (PTHrP) was discovered as a causative factor of humoral hypercalcemia of malignancy (HHM). The present study elucidates the histopathological characters of incisor lesions in the HHM rat model. Nude rats were implanted with PTHrP-expressing tumor (LC-6) cells, maintained for 12 weeks, after which the mandibular incisors were collected. Incisor fractures were observed grossly. Microscopically, hypercalcified dentin, dentin niche with osteodentin, and thinning of dentin were observed. Hypercalcified dentin was observed as a basophilic line of calcified dentin without associated odontoblastic changes, whereas dentin niche and thinning of dentin occurred with osteodentin and loss of cell height, respectively. In contrast with hypercalcified dentin, which was distributed throughout the dentin, dentin niche and thinning of dentin were localized to the labial area of the apical and middle region, and to the labial and lingual areas of the middle and incisal region, respectively. These results suggest that hypercalcemia affected the entire calcification process resulting in hypercalcified dentin, and that high PTHrP concentrations affected selective populations of odontoblasts resulting in formation of dentin niche and thinning of dentin. The localization of dentin niche and thinning of dentin also suggest that PTHrP may also be involved odontoblastic development in the rat. 相似文献
29.
Roles of the Maltese cross form in the development of parasitemia and protection against Babesia microti infection in mice
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)
Yokoyama N Bork S Nishisaka M Hirata H Matsuo T Inoue N Xuan X Suzuki H Sugimoto C Igarashi I 《Infection and immunity》2003,71(1):411-417
Babesia microti, a hemoprotozoan parasite of rodents, is also important as a zoonotic agent of human babesiosis. The Maltese cross form, which consists of four masses in an erythrocyte, is characteristic of the developmental stage of B. microti. Monoclonal antibody (MAb) 2-1E, which specifically recognizes the Maltese cross form of B. microti, has been described previously. In the present study, we examined the roles of the Maltese cross form during the infectious course of B. microti in mice. The number of the Maltese cross form increased in the peripheral blood of infected mice prior to the peak of parasitemia. With confocal laser scanning microscopy, MAb 2-1E was found to be reactive with the ring form, with the parasites undergoing transformation to the Maltese cross form and subsequent division, and also with extracellular merozoites. Furthermore, the Maltese cross form-related antigen (MRA) gene was isolated from a B. microti cDNA library by immunoscreening with MAb 2-1E, and the nucleotide sequence was determined. Genomic analyses indicated that the MRA gene exists as a single-copy gene in B. microti. Immunization of mice with recombinant MRA induced significant protective immunity against B. microti infection. These findings indicate that the Maltese cross form plays important roles in both the development of parasitemia and the protective response against the infection. 相似文献
30.
Sotos syndrome and haploinsufficiency of NSD1: clinical features of intragenic mutations and submicroscopic deletions 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Journal of medical genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)