全文获取类型
收费全文 | 3362286篇 |
免费 | 241070篇 |
国内免费 | 8554篇 |
专业分类
耳鼻咽喉 | 46443篇 |
儿科学 | 112317篇 |
妇产科学 | 93092篇 |
基础医学 | 472446篇 |
口腔科学 | 92441篇 |
临床医学 | 304910篇 |
内科学 | 660436篇 |
皮肤病学 | 78481篇 |
神经病学 | 273008篇 |
特种医学 | 130188篇 |
外国民族医学 | 1282篇 |
外科学 | 505521篇 |
综合类 | 69792篇 |
现状与发展 | 6篇 |
一般理论 | 1221篇 |
预防医学 | 257639篇 |
眼科学 | 75870篇 |
药学 | 247508篇 |
9篇 | |
中国医学 | 6787篇 |
肿瘤学 | 182513篇 |
出版年
2019年 | 25881篇 |
2018年 | 36587篇 |
2017年 | 28014篇 |
2016年 | 32180篇 |
2015年 | 36271篇 |
2014年 | 50019篇 |
2013年 | 75551篇 |
2012年 | 101059篇 |
2011年 | 107113篇 |
2010年 | 64620篇 |
2009年 | 61788篇 |
2008年 | 100544篇 |
2007年 | 107046篇 |
2006年 | 108579篇 |
2005年 | 104518篇 |
2004年 | 101122篇 |
2003年 | 97681篇 |
2002年 | 94582篇 |
2001年 | 161232篇 |
2000年 | 165688篇 |
1999年 | 140200篇 |
1998年 | 40212篇 |
1997年 | 35784篇 |
1996年 | 35983篇 |
1995年 | 34700篇 |
1994年 | 32155篇 |
1993年 | 30134篇 |
1992年 | 110094篇 |
1991年 | 106352篇 |
1990年 | 103295篇 |
1989年 | 99736篇 |
1988年 | 91537篇 |
1987年 | 89834篇 |
1986年 | 84046篇 |
1985年 | 80308篇 |
1984年 | 60043篇 |
1983年 | 50844篇 |
1982年 | 29910篇 |
1981年 | 26994篇 |
1979年 | 53336篇 |
1978年 | 37491篇 |
1977年 | 31974篇 |
1976年 | 29652篇 |
1975年 | 31693篇 |
1974年 | 37323篇 |
1973年 | 35573篇 |
1972年 | 33271篇 |
1971年 | 30665篇 |
1970年 | 28571篇 |
1969年 | 26931篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
981.
982.
H L Elliott P A Meredith L Campbell J L Reid 《Clinical pharmacology and therapeutics》1988,43(5):554-560
An exaggerated fall in blood pressure has been reported with the combination of an alpha 1-blocker and a calcium antagonist. This study investigated, in a placebo-controlled, randomized crossover trial, the clinical usefulness of the combination of prazosin (2 mg b.i.d.) and verapamil (160 mg b.i.d.). Therapeutic efficacy was monitored at regular outpatient visits: average supine and erect blood pressures were, respectively, 175/99 and 176/103 mm Hg with placebo, 160/91 and 164/96 mm Hg with single drug treatment, and 152/84 and 152/89 mm Hg with combination therapy. This significant and clinically useful reduction in blood pressure had an overall magnitude of approximately 28/18 mm Hg (supine) and 29/19 mm Hg (erect). Further measurements were made during a series of intensive study days, and the most important additional finding was a pharmacokinetic interaction that resulted in increased peak concentrations and bioavailability of prazosin. In conclusion, the combination of prazosin and verapamil proved effective in the treatment of 12 patients with essential hypertension who had been poorly responsive to conventional treatment with a beta-blocker and thiazide diuretic. 相似文献
983.
984.
985.
Barbara A. Bresnahan Christopher P. Johnson Matthew J. McIntosh Donald Stablein Sundaram Hariharan 《American journal of transplantation》2002,2(4):366-372
The optimal allocation of cadaveric kidneys for transplantation with reference to human leukocyte antigen (HLA) match and sharing these organs to a distant center remains controversial. The current analysis was performed using the United Network for Organ Sharing (UNOS) database for cadaveric kidney transplants (Tx) between 1988 and 1997. The graft survivals of zero-mismatch (matched) kidneys with the mate (mismatched) kidneys were compared. There were 2385 donors and 4770 Tx. Significant differences in recipient demographics between matched and mismatched Tx were: fewer African-American race (AA) in the matched group (9.0% vs. 21.9%), higher number of previous Tx (25.5% vs. 14.8%) and elevated mean cold ischemia time (24.0 vs. 22.2 h). Post-Tx dialysis requirements were similar (22.8% vs. 24.1%, p = 0.62) and matched kidneys had to travel more distance (920 vs. 232 miles). Using a Cox model, the matched group had a decreased relative hazard of graft failure of 23.0% (p = 0.0002) or 35% (p < 0.0001) with and without censoring for death. There was significantly better graft survival in the matched recipients in all pairs except AA (matched) and non-AA (mismatched). For older donors (> or = 50 years, n = 1508), the matched grafts survival was marginally significant (p =0.05). Matched kidneys have improved survival compared with the mismatched kidneys despite the longer distance traveled. The benefit of mismatched transplants was predominantly seen in non-AA. 相似文献
986.
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
987.
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
988.
989.
D. Lothschütz M. Jennewein S. Pahl H.F. Lausberg A. Eichler W. Mutschler R.G. Hanselmann M. Oberringer 《Inflammation research》2002,51(8):416-422
OBJECTIVE AND DESIGN: Inflammatory and tumorous bronchi were screened in order to obtain new tumor relevant cytogenetic parameters. MATERIAL OR SUBJECTS: Bronchial cells of 32 patients were cultivated by standard cell culture procedures. METHODS: Tetraploidy and aneuploidy was determined by enumeration of chromosome 7 and 8 versus the number of centrosomes. The resulting data were correlated with histopathological data. RESULTS: Tetra- and aneuploidy of epithelial cells were detectable in 76% of tumor cell cultures, 75% of high grade inflammatory tissues and 40% of non- and low grade-inflammatory tissues. Additionally, we observed centrosome hyper-amplification and multipolar mitoses not only in the tumor but also in the early stages of inflammation. CONCLUSION: Inflammatory bronchi already show tumor-specific features and may consequently represent the preliminary genetic stage of cancer development in bronchi. 相似文献
990.
A. Giacometti O. Cirioni G. Greganti A. Fineo R. Ghiselli M. Del Prete F. Mocchegiani B. Fileni F. Caselli E. Petrelli V. Saba G. Scalise 《European journal of clinical microbiology & infectious diseases》2002,21(7):553-556
The in vitro activities of povidone iodine, potassium peroxymonosulfate, and dimethyldidecylammonium chloride were investigated
against 379 nosocomial isolates of Staphylococcus aureus and Pseudomonas aeruginosa responsible for surgical wound infections in patients operated on between July 1995 and June 2001. Overall, the isolates
were inhibited by the antiseptics at concentrations below those used routinely. In spite of increasing resistance to the various
antibiotics used to treat surgical wound infections, no significant variation in the susceptibility to antiseptics was demonstrated
during this 6-year study.
Electronic Publication 相似文献