全文获取类型
收费全文 | 11538篇 |
免费 | 1125篇 |
国内免费 | 112篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 837篇 |
妇产科学 | 27篇 |
基础医学 | 1862篇 |
口腔科学 | 150篇 |
临床医学 | 532篇 |
内科学 | 977篇 |
皮肤病学 | 139篇 |
神经病学 | 557篇 |
特种医学 | 472篇 |
外科学 | 219篇 |
综合类 | 717篇 |
一般理论 | 1篇 |
预防医学 | 4730篇 |
眼科学 | 30篇 |
药学 | 1051篇 |
4篇 | |
中国医学 | 297篇 |
肿瘤学 | 154篇 |
出版年
2024年 | 18篇 |
2023年 | 162篇 |
2022年 | 593篇 |
2021年 | 972篇 |
2020年 | 530篇 |
2019年 | 506篇 |
2018年 | 465篇 |
2017年 | 432篇 |
2016年 | 455篇 |
2015年 | 518篇 |
2014年 | 669篇 |
2013年 | 998篇 |
2012年 | 607篇 |
2011年 | 649篇 |
2010年 | 485篇 |
2009年 | 436篇 |
2008年 | 472篇 |
2007年 | 471篇 |
2006年 | 350篇 |
2005年 | 326篇 |
2004年 | 305篇 |
2003年 | 272篇 |
2002年 | 246篇 |
2001年 | 200篇 |
2000年 | 138篇 |
1999年 | 126篇 |
1998年 | 136篇 |
1997年 | 119篇 |
1996年 | 109篇 |
1995年 | 104篇 |
1994年 | 103篇 |
1993年 | 72篇 |
1992年 | 82篇 |
1991年 | 48篇 |
1990年 | 52篇 |
1989年 | 52篇 |
1988年 | 56篇 |
1987年 | 46篇 |
1986年 | 37篇 |
1985年 | 51篇 |
1984年 | 43篇 |
1983年 | 42篇 |
1982年 | 49篇 |
1981年 | 35篇 |
1980年 | 22篇 |
1979年 | 22篇 |
1978年 | 36篇 |
1977年 | 13篇 |
1976年 | 20篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Takaharu Negoro Kanami Orihara Tomoko Irahara Hiroshi Nishiyama Kanae Hagiwara Risa Nishida Hiroki Takagi Kazue Satoh Yoshiki Yamamoto Shunichi Shimizu Tamio Hagiwara Masakazu Ishii Toshihiro Tanioka Yasuko Nakano Ken Takeda Isao Yoshimura Yoji Iikura Takashi Tobe 《Pediatric allergy and immunology》2006,17(8):583-590
Although many single nucleotide polymorphism (SNP) studies have reported an association of atopy, allergic diseases and total serum immunoglobulin E (IgE) levels, almost all of these studies sought risk factors for the onset of these allergic diseases. Furthermore, many studies have analyzed a single gene and hardly any have analyzed environmental factors. In these analyses, the results could be masked and the effects of other genes and environmental factors may be decreased. Here, we described the correlation between four genes [interleukin (IL)-4 (C-590T), IL-4 receptor (A1652G), FCER1B (G6842A) and STAT6 (G2964A)] in connection with IgE production; the role of IL-10 (C-627A) as a regulatory cytokine of allergy; and the severity of food allergy (FA) and atopic eczema (AE) in 220 Japanese allergic children. In addition to these SNPs, environmental factors, i.e., patient's attitude, indoor environment, and so on, were also investigated in this study. Our study was retrospective, and the correlation was analyzed by our defined clinical scores divided into three terms: worst symptoms, recent symptoms and general amelioration at the most recent examination during the disease course. Our results indicated that IL-10 AA, the genotype with lower IL-10 production, is associated with higher IgE levels in the serum (p < 0.0001, estimate; 0.912). Marginal liver abnormalities were observed in the subject group with both FA and AE (p < 0.1191, estimate; 0.1490). Our defined clinical scores enabled evaluation of various aspects of disease severity. Based on the scores, while no single SNP selected in this study determined severity, the combination of the SNP with laboratory data and environmental factors appeared to determine severity. 相似文献
23.
Fast CT-PRESS-based spiral chemical shift imaging at 3 Tesla. 总被引:2,自引:0,他引:2
Dirk Mayer Dong-Hyun Kim Elfar Adalsteinsson Daniel M Spielman 《Magnetic resonance in medicine》2006,55(5):974-978
A new sequence is presented that combines constant-time point-resolved spectroscopy (CT-PRESS) with fast spiral chemical shift imaging. It allows the acquisition of multivoxel spectra without line splitting with a minimum total measurement time of less than 5 min for a field of view of 24 cm and a nominal 1.5x1.5-cm2 in-plane resolution. Measurements were performed with 17 CS encoding steps in t1 (Deltat1=12.8 ms) and an average echo time of 151 ms, which was determined by simulating the CT-PRESS experiment for the spin systems of glutamate (Glu) and myo-inositol (mI). Signals from N-acetyl-aspartate, total creatine, choline-containing compounds (Cho), Glu, and mI were detected in a healthy volunteer with no or only minor baseline distortions within 14 min on a 3 T MR scanner. 相似文献
24.
BACKGROUND/PURPOSE: Sensitive skin is a condition associated with reduced tolerance to environmental factors and/or the application of topical products, such as cosmetics. Its pathophysiology has not been fully elucidated and few data are available on its prevalence. The aim of this study was to investigate possible correlation between objective sensitivity and skin surface microrelief. METHODS: During an epidemiological survey conducted for a campaign promoted by International Society of Plastic Dermatology in Italy, 243 adult healthy subjects of both sexes with no evident dermatological disorder but positive to the lactic acid stinging test, were submitted to cyanoacrylate stratum corneum stripping from the volar forearm for the determination of the irregularity of the skin surface microrelief (irregularity skin index (ISI)). RESULTS: A significant correlation was found between intensity of symptoms in stingers and ISI (r(s)=-0.47; P<0.001). CONCLUSION: Sensitive skin is common in the healthy population. ISI can contribute towards the identification of subjects with sensitive skin and the development of more specific skin treatments for this prevalent condition. 相似文献
25.
目的 探讨中药膳食配合运动干预对肥胖性脂肪肝的影响。方法 将68例脂肪肝患者随机分为对照组和观察组各34例。对照组常规给予低脂饮食和易善复、大黄庶虫丸等降酶保肝治疗;观察组按常规方法治疗外,采用中医辨证施食予以活血化淤、健脾利湿的中药膳食疗法配合运动干预.疗程均为1年。结果 治疗后观察组体重、甘油三酯、总胆固醇、谷丙转氨酶等显著低于对照组(均P〈0.01)。结论 中药膳食配合运动干预对肥胖性脂肪肝疗效显著。 相似文献
26.
Sule Jman Redzic 《Ecology of food and nutrition》2006,45(3):189-232
This article presents first systematical procedure results on traditional usage of wild, edible, vitaminous, and aromatic plants in the nutrition of human population in Bosnia and Herzegovina (W. Balkan peninsula; SE Europe). By method of an ethnobotanical interview, which comprised of over 250 persons, whose average age was 55, and by research on edible wild flora all around Bosnia and Herzegovina that extended over many years, detected were 308 plants belonging to 73 plant families that are being used in nutrition and diet of indigenous population. Edible wild plants are used as delicious vegetables, fruits, peer and spices, in either fresh, raw, or dried condition. Plants are being used for the making of cooked food (33%), fresh salads (19%), mush and bread (17%), or as fresh, wild fruits and drinks (13%) or as spices and ethno-pharmacological potions (10%). The majority of identified, wild edible plants may satisfy the daily human need for elementary nutrition material, particularly those of vitamins C and A, and for some minerals, according to the regulations of World Health Organization (WHO). 相似文献
27.
[目的]针对食物中毒事件追查源头的困难局面,探索1种新的食物中毒追查方法。[方法]通过分析各种常见类型食物中毒的潜伏期,结合各种实际情况,探讨存样食物保存的时间和方法。[结果]存样食物至少要保存24h。[结论]这种存样待检方法有其先进性,但仍存在不少问题,需进一步改进。 相似文献
28.
29.
M. Wensing A. H. Penninks† S. L. Hefle‡ J. H. Akkerdaas§ R. van Ree§ S. J. Koppelman† C. A. F. M. Bruijnzeel-Koomen A. C. Knulst 《Clinical and experimental allergy》2002,32(12):1757-1762
BACKGROUND: The risk for allergic reactions depends on the sensitivity of individuals and the quantities of offending food ingested. The sensitivity varies among allergic individuals, as does the threshold dose of a food allergen capable of inducing an allergic reaction. OBJECTIVE: This study aimed at determining the distribution of minimum provoking doses of hazelnut in a hazelnut-allergic population. METHODS: Thirty-one patients with a history of hazelnut-related allergic symptoms, a positive skin prick test to hazelnut and/or an elevated specific IgE level, were included. Double-blind, placebo-controlled food challenges (DBPCFC) were performed with seven increasing doses of dried hazelnut (1 mg to 1 g hazelnut protein) randomly interspersed with seven placebo doses. RESULTS: Twenty-nine patients had a positive challenge. Itching of the oral cavity and/or lips was the first symptom in all cases. Additional gastrointestinal symptoms were reported in five patients and difficulty in swallowing in one patient. Lip swelling was observed in two patients, followed by generalized urticaria in one of these. Threshold doses for eliciting subjective reactions varied from a dose of 1 mg up to 100 mg hazelnut protein (equivalent to 6.4-640 mg hazelnut meal). Extrapolation of the dose-response curve showed that 50% of our hazelnut-allergic population will suffer from an allergic reaction after ingestion of 6 mg (95% CI, 2-11 mg) of hazelnut protein. Objective symptoms were observed in two patients after 1 and 1,000 mg, respectively. CONCLUSION: DBPCFCs demonstrated threshold doses in half of the hazelnut-allergic patients similar to doses previously described to be hidden in consumer products. This stresses the need for careful labelling and strategies to prevent and detect contamination of food products with hazelnut residues. 相似文献
30.
提供了预富集-石墨炉原子吸收光谱法测定药食两用中药浸泡液中的痕量镉的新方法。采用吡咯烷二硫代氨基甲酸铵(APDC)作配位剂,在pH 5.0-8.0的条件下,用固体硅胶捕集、抽滤分离Cd-APDC配合物,然后用1 moL/L盐酸从膜滤纸上洗下硅胶,得到能够直接用石墨炉原子吸收光谱法测定的镉悬浊液。该法简便快速,富集100倍时的特征质量为2.8×10-14g。用此方法测定4药食两用中药浸泡液中的痕量镉,当n=5时,标准偏差为0.002 5-0.005 8,RSD为:0.012-0.052,样品的加标回收率为91.8%和111.1%,结果较为满意。 相似文献