全文获取类型
收费全文 | 2590867篇 |
免费 | 187970篇 |
国内免费 | 7615篇 |
专业分类
耳鼻咽喉 | 34396篇 |
儿科学 | 85819篇 |
妇产科学 | 71836篇 |
基础医学 | 364025篇 |
口腔科学 | 69827篇 |
临床医学 | 234880篇 |
内科学 | 516607篇 |
皮肤病学 | 62636篇 |
神经病学 | 213686篇 |
特种医学 | 100157篇 |
外国民族医学 | 736篇 |
外科学 | 387456篇 |
综合类 | 50755篇 |
现状与发展 | 5篇 |
一般理论 | 969篇 |
预防医学 | 196779篇 |
眼科学 | 56803篇 |
药学 | 188307篇 |
9篇 | |
中国医学 | 5383篇 |
肿瘤学 | 145381篇 |
出版年
2021年 | 20012篇 |
2019年 | 20642篇 |
2018年 | 29309篇 |
2017年 | 22625篇 |
2016年 | 26252篇 |
2015年 | 29547篇 |
2014年 | 40495篇 |
2013年 | 60498篇 |
2012年 | 80315篇 |
2011年 | 84586篇 |
2010年 | 51112篇 |
2009年 | 49257篇 |
2008年 | 79080篇 |
2007年 | 83899篇 |
2006年 | 85647篇 |
2005年 | 81777篇 |
2004年 | 78745篇 |
2003年 | 76075篇 |
2002年 | 73351篇 |
2001年 | 128441篇 |
2000年 | 131347篇 |
1999年 | 110552篇 |
1998年 | 31407篇 |
1997年 | 28060篇 |
1996年 | 28357篇 |
1995年 | 27490篇 |
1994年 | 25167篇 |
1993年 | 23527篇 |
1992年 | 85195篇 |
1991年 | 81607篇 |
1990年 | 78835篇 |
1989年 | 76135篇 |
1988年 | 69527篇 |
1987年 | 68054篇 |
1986年 | 63603篇 |
1985年 | 60547篇 |
1984年 | 44982篇 |
1983年 | 37970篇 |
1982年 | 22488篇 |
1981年 | 20020篇 |
1979年 | 38982篇 |
1978年 | 27457篇 |
1977年 | 23284篇 |
1976年 | 21524篇 |
1975年 | 22831篇 |
1974年 | 26791篇 |
1973年 | 25373篇 |
1972年 | 23753篇 |
1971年 | 21962篇 |
1970年 | 20186篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
971.
972.
This paper examines the effects of intraocular epinephrine on systemic blood pressure and heart rate during cataract surgery. Sixty-two patients were studied, all of whom received an intraocular infusion of approximately 200 to 300 mL of balanced salt solution with 0.5 mL of epinephrine 1:1000. There was no statistically significant change in blood pressure or heart rate during the time of epinephrine administration. Electrocardiogram monitoring during surgery showed no changes. We believe that dilute concentrations of epinephrine administered during extracapsular cataract extraction pose little threat of systemic toxicity. 相似文献
973.
The clinical, radiologic, and histopathologic findings of a case of bilateral dacryops is reported in a 49-year-old man. The patient presented with cystic masses located in superior lateral orbits and underwent bilateral excisions of these without any postoperative complications. 相似文献
974.
975.
Of 7 plasmids we tested, the plasmid pORF2 was eliminated in vitro with the most efficiency by treatment with subinhibitory concentrations of novobiocin, coumermycin and 10 quinolones. It showed a cure rate of 43% by enoxacin; 12% by novobiocin, pefloxacin, ciprofloxacin and CI-934; 7% by coumermycin and ofloxacin; 9% by amifloxacin; and 4% by AM-833. On the other hand, pSC194, pBR322 and pMH612 were poorly cured in vitro by quinolones, except pSC194 which was cured 33% by enoxacin. R1, pP1603, and pUB110 were unaffected by the treatment. Mice were challenged intraperitoneally with a 2XLD50 of Escherichia coli carrying the ORF2 plasmid and were treated per os with 1 X or 1/2 X ED50 of either enoxacin or CI-934. The frequency of loss of ampicillin resistance determined 3 h after treatment shows curing effects of 92% for CI-934, 89% for enoxacin and 20% for untreated control. 相似文献
976.
977.
978.
979.
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
980.
M. Evans 《European journal of clinical microbiology & infectious diseases》2002,21(8):621-623
Ten oxacillin-sensitive Staphylococcus aureus strains were grown on agar containing four times their ciprofloxacin MIC to determine if exposure to ciprofloxacin would
increase their resistance to oxacillin. All strains grew on the ciprofloxacin-containing agar and subsequently grew on oxacillin-salt
agar. The geometric mean MICs for oxacillin increased one- to sixteen-fold and remained elevated after ten passages on antibiotic-free
agar. The mecA gene was not detected in any strain. There was no increase in oxacillin MICs when the bacteria were passaged on agar containing
four times their MIC of piperacillin/tazobactam. Exposure of oxacillin-sensitive strains of Staphylococcus aureus to ciprofloxacin may increase their MICs to oxacillin.
Electronic Publication 相似文献