全文获取类型
收费全文 | 9242篇 |
免费 | 488篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 784篇 |
妇产科学 | 398篇 |
基础医学 | 989篇 |
口腔科学 | 167篇 |
临床医学 | 465篇 |
内科学 | 1718篇 |
皮肤病学 | 188篇 |
神经病学 | 346篇 |
特种医学 | 211篇 |
外科学 | 1801篇 |
综合类 | 271篇 |
一般理论 | 3篇 |
预防医学 | 377篇 |
眼科学 | 587篇 |
药学 | 528篇 |
中国医学 | 25篇 |
肿瘤学 | 780篇 |
出版年
2023年 | 64篇 |
2022年 | 136篇 |
2021年 | 325篇 |
2020年 | 159篇 |
2019年 | 230篇 |
2018年 | 317篇 |
2017年 | 204篇 |
2016年 | 274篇 |
2015年 | 246篇 |
2014年 | 369篇 |
2013年 | 403篇 |
2012年 | 609篇 |
2011年 | 616篇 |
2010年 | 395篇 |
2009年 | 291篇 |
2008年 | 479篇 |
2007年 | 506篇 |
2006年 | 472篇 |
2005年 | 387篇 |
2004年 | 295篇 |
2003年 | 303篇 |
2002年 | 257篇 |
2001年 | 221篇 |
2000年 | 218篇 |
1999年 | 195篇 |
1998年 | 87篇 |
1997年 | 59篇 |
1996年 | 49篇 |
1995年 | 42篇 |
1992年 | 94篇 |
1991年 | 95篇 |
1990年 | 71篇 |
1989年 | 69篇 |
1988年 | 71篇 |
1987年 | 74篇 |
1986年 | 80篇 |
1985年 | 104篇 |
1984年 | 56篇 |
1983年 | 56篇 |
1982年 | 39篇 |
1981年 | 35篇 |
1980年 | 34篇 |
1979年 | 80篇 |
1978年 | 45篇 |
1977年 | 47篇 |
1976年 | 39篇 |
1975年 | 35篇 |
1974年 | 42篇 |
1973年 | 48篇 |
1972年 | 46篇 |
排序方式: 共有9753条查询结果,搜索用时 15 毫秒
71.
72.
Experimental mycetoma-like lesions developed in guinea pigs after subcutaneous injection of Nocardia asteroides. Although delayed hypersensitivity appeared earlier, increased macrophage migration inhibition and microbicidal activity appeared after 7 weeks. When the lesions healed, high cell-mediated immunity was present. Cell-mediated immunity was transferred to normal recipient guinea pigs from healed donor guinea pigs by spleen cell transfer. Recipient guinea pigs showed marked protection against challenge with N. asteroides. 相似文献
73.
N. W. Davies A. I. Pettit R. Agarwal N. B. Standen 《Pflügers Archiv : European journal of physiology》1991,419(1):25-31
We have examined the effects of 4-aminopyridine (4-AP) on single ATP-dependent potassium channels in patches excised from frog skeletal muscle. 4-AP applied to the internal face of the membrane caused a flickery block. We could not detect any flickery block when 10 mM 4-AP was applied to the external surface of the membrane. The reduction in mean unitary current by internal 4-AP was consistent with 11 binding with a K
d of 3.3 mM at 0 mV. The block was voltage-dependent, increasing with depolarization with an effective valency of 0.57. Rate constants for blocking and unblocking by 4-AP were obtained by fitting functions to the distribution of current amplitudes. Both rate constants were voltage-dependent. At 0 mV they were 17 mM–1 ms–1 and 61 ms–1. Simulation of the block using these rate constants produced a flickery block very similar to that observed experimentally. 相似文献
74.
M. K. Agarwal Ph.D. R. T. Jones B.S. J. W. Yunginger M.D. 《The Journal of allergy and clinical immunology》1982,70(6):437-444
To develop a model for mold allergen extract standardization, we studied eight commercial Alternaria extracts from various suppliers by a variety of immunochemical and physicochemical techniques, including measurement of Alt-I, a purified allergenic fraction of Alternaria. Wide variations were noted in the allergenic and antigenic potencies of these extracts. Estimates of Alt-I content measured by Alt-I RAST inhibition and by radioimmunoassay correlated significantly (p < 0.05), but Alt-I activity by either method could not be correlated with allergenic potency as measured by RAST inhibition using solid-phase Alternaria. Each test extract produced unique and differing patterns of Coomassie blue-stained bands in isoelectrofocusing gels and in crossed immunoelectrophoresis gels using rabbit antibodies to Alternaria. The optimal method for mold allergen standardization involves a combination of RAST inhibition, isoelectrofocusing, and crossed immunoelectrophoresis techniques, and, if possible, quantitation of individual allergens. 相似文献
75.
Wang P Sun SH Silver PB Chan CC Agarwal RK Wiggert B Kohn LD Jamieson GA Caspi RR 《Journal of leukocyte biology》2003,73(1):57-64
Methimazole (methyl-mercapto-imidazole, MMI), a compound used clinically in therapy of Graves' thyroiditis, was found to inhibit development of several autoimmune diseases in animal models. It was suggested on the basis of in vitro data that inhibition is through down-regulation of interferon-gamma (IFN-gamma)-induced expression of major histocompatibility complex class I and class II molecules. Here, we investigate the effect of MMI on experimental autoimmune uveoretinitis (EAU) and study its mechanism(s). Treatment of EAU with MMI administered in drinking water inhibited induction of the disease and associated antigen (Ag)-specific proliferation and cytokine production by draining lymph node cells (LNCs). The treatment was protective only if administered during the first but not during the second week after immunization, suggesting an effect on the induction phase of EAU. It is interesting that MMI inhibited disease in IFN-gamma knockout mice, indicating that the in vivo protective effect is IFN-gamma-independent. Flow cytometric analysis of draining LNCs extracted 5 days after immunization showed that MMI partly to completely reversed the increase in Mac-1(+)/class I(+)/class II(+) cells induced by immunization and reduced the proportion of B7-1 and CD40-positive cells, suggesting a deficit in the Ag-presenting cell (APC) population. APC from untreated mice largely restored antigen-specific proliferation of MMI-treated LNCs. We suggest that MMI inhibits EAU at least in part by preventing the recruitment and/or maturation of APC, resulting in reduced generation of Ag-specific T cells. 相似文献
76.
Agarwal R Heinz T 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2001,47(3):240-243
The HemoCue B-hemoglobin test system (HemoCue, Inc., Mission Viejo, CA) is a photometric method for rapid bedside determination of hemoglobin (Hb). We compared the performance of HemoCue measured Hb against Coulter STK-S (CSTK) measured Hb in chronic hemodialysis (HD) patients in two different settings. In the first setting, Hemocue analysis was performed by multiple HD technicians (n = 132). In the second setting, a nurse trained in proper specimen handling performed the HemoCue analysis (n = 74). Simultaneous measurement of Hb by the CSTK method was performed. First setting: Hb was 11.1+/-1.66 (SD) g/dl by CSTK and 11.7+/-2.29 g/dl by HemoCue. The HemoCue method consistently overestimated Hb by an average (SD) of 0.63 (1.267) g/dl (95% CI = 0.42 to 0.85). Hb was overestimated in 25.7% and underestimated in 2.3% of the patients by 1 g/dl or more. Thus, the HemoCue system was accurate within 1 g/dl only 72% of the time. Second setting: HemoCue overestimated Hb by an average (SD) of 0.29 (0.52) g/dl (95% CI, 0.17 to 0.41). Only 4% of all patients had errors in estimation of 1 g/dl or more. Thus, HemoCue was accurate in 96% of the patients within 1 g/dl. After reviewing the two protocols, the primary difference in the two studies was the technique used to obtain the specimens. When performed properly, Hb testing using the HemoCue testing system had a high level of agreement with CSTK. Appropriate training in specimen handling, as well as test performance, will increase accuracy and reliability of bedside hemoglobinometry. 相似文献
77.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
78.
Neerja Surolia K. K. Agarwal 《Indian journal of otolaryngology and head and neck surgery》1987,39(3):122-123
Paraganglioma of the larynx are rare tumours and only 25 cases have been reported in the world literature. Paraganglioma of larynx are paired superior and inferior laryngeal glomus bodies in association with superior and recurrent laryngeal nerves respectively. The tumours arising from laryngeal glomus bodies appear in subglottic space, in trachea, as a supraglottic mass and as a neck swelling. A case of malignant paraganglioma of the larynx with metastasis to the cervical lymphnodes and lungs have been presented with brief review of literature. 相似文献
79.
80.