全文获取类型
收费全文 | 8721篇 |
免费 | 531篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 276篇 |
妇产科学 | 263篇 |
基础医学 | 903篇 |
口腔科学 | 139篇 |
临床医学 | 783篇 |
内科学 | 2276篇 |
皮肤病学 | 82篇 |
神经病学 | 909篇 |
特种医学 | 338篇 |
外科学 | 941篇 |
综合类 | 93篇 |
一般理论 | 6篇 |
预防医学 | 985篇 |
眼科学 | 158篇 |
药学 | 569篇 |
中国医学 | 2篇 |
肿瘤学 | 429篇 |
出版年
2023年 | 32篇 |
2022年 | 41篇 |
2021年 | 178篇 |
2020年 | 83篇 |
2019年 | 169篇 |
2018年 | 194篇 |
2017年 | 163篇 |
2016年 | 147篇 |
2015年 | 172篇 |
2014年 | 281篇 |
2013年 | 391篇 |
2012年 | 633篇 |
2011年 | 695篇 |
2010年 | 383篇 |
2009年 | 376篇 |
2008年 | 575篇 |
2007年 | 691篇 |
2006年 | 649篇 |
2005年 | 616篇 |
2004年 | 584篇 |
2003年 | 540篇 |
2002年 | 475篇 |
2001年 | 106篇 |
2000年 | 71篇 |
1999年 | 81篇 |
1998年 | 106篇 |
1997年 | 80篇 |
1996年 | 63篇 |
1995年 | 71篇 |
1994年 | 49篇 |
1993年 | 50篇 |
1992年 | 61篇 |
1991年 | 38篇 |
1990年 | 45篇 |
1989年 | 67篇 |
1988年 | 40篇 |
1987年 | 28篇 |
1986年 | 28篇 |
1985年 | 19篇 |
1984年 | 34篇 |
1983年 | 21篇 |
1982年 | 26篇 |
1981年 | 25篇 |
1980年 | 18篇 |
1979年 | 11篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 9篇 |
1974年 | 6篇 |
1971年 | 6篇 |
排序方式: 共有9278条查询结果,搜索用时 312 毫秒
141.
Michael Mahmoudi Cedric Delhaye Ron Waksman 《Cardiovascular Revascularization Medicine》2011,12(6):385
Compared with medical therapy, percutaneous coronary intervention has been shown to reduce the rates of death and recurrent ischemia in patients presenting with acute coronary syndromes (ACS). In the current interventional era, both drug-eluting stents (DES) and bare-metal stents (BMS) have been widely used, despite the fact that the use of DES in the context of ACS was initially an “off-label” indication and that ACS has been associated with stent thrombosis (ST). In contrast to the wealth of data available for the use of DES in patients with ST-elevation myocardial infarction, data regarding the performance of DES in non–ST-elevation ACS is restricted to a handful of registries with conflicting data. The aim of this review was to summarize the safety and efficacy of DES in the entire spectrum of ACS. 相似文献
142.
Maya Frank-Wolf Josef Tovbin Yifat Wiener Ortal Neeman Yaffa Kurzweil Ron Maymon 《The journal of maternal-fetal & neonatal medicine》2017,30(13):1637-1640
Purpose: Since more senior and attending physicians work in labor wards during morning shifts, we expect a better delivery outcome during that time period.Materials and methods: A retrospective study was conducted between 1/2005 and 12/2014. Records of 56 428 singleton deliveries from a tertiary hospital in which cord blood pH was routinely measured at birth were analyzed. Time of birth was divided into shifts: 7 AM–3?PM (morning shift), 3?PM–11?PM (afternoon shift), and 11?PM–7 AM (night shift). Additional stratification compared weekdays and weekend deliveries.Results: 19?601, 18?429, and 18?398 neonates were born during morning, afternoon, and night shifts, respectively. There was no significant difference in maternal age, neonatal weight, or mean 5-min Apgar score among the three shift periods. Furthermore, there was no correlation between shift time of delivery and newborn acidosis with respect to cord pH less than 7 (0.1% in each time periods, p?=?0.67). Despite the above, instrumental deliveries and cesarean sections were more common in the morning shift compared to the afternoon and night shift, respectively (p?=?0.001 each).Conclusions: Although shift time of delivery was found to be related to mode of delivery it was not related to either 5-min Apgar score or newborn acidosis as reflected by cord pH. 相似文献
143.
Acetyl phosphate is a central metabolite involved in a broad range of versatile cellular functions. Recently it was observed that in Escherichia coli the acetyl phosphate pathway is required for efficient ATP-dependent proteolysis. Deletion of the operon coding for acetyl phosphate metabolism (ΔackApta) results in a very low cytoplasmic level of acetyl phosphate and impaired proteolysis. Here we show that the ΔackApta mutation affects additional components of the protein quality control system. Thus, this deletion is accompanied by a decrease in protein refolding and rescue from aggregates. These results indicate the involvement of the acetyl phosphate pathway in chaperone capabilities, in addition to their effect on proteolysis. 相似文献
144.
It is widely accepted that the heat shock response is critical for quality control of mature proteins. This function is carried out mainly by chaperones and proteases. Recently, a new group of conserved heat shock proteins essential for growth at high temperature has been characterized. These proteins are involved in regulating and maintaining efficient translation under heat shock. 相似文献
145.
Schoofs MW van der Klift M Hofman A de Laet CE Herings RM Stijnen T Pols HA Stricker BH 《Annals of internal medicine》2003,139(6):476-482
Since most hip fractures are related to osteoporosis, treating accelerated bone loss can be an important strategy to prevent hip fractures. Thiazides have been associated with reduced age-related bone loss by decreasing urinary calcium excretion. 相似文献
146.
du Preez M Conroy RM Wright JA Moyo S Potgieter N Gundry SW 《The American journal of tropical medicine and hygiene》2008,79(5):696-701
To determine the effectiveness of ceramic filters in reducing diarrhea, we conducted a randomized controlled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody diarrhea was recorded daily over 6 months using pictorial diaries for children 24-36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50-0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody diarrhea was 0.20 (95% CI, 0.09-0.43; P < 0.001) and for non-bloody diarrhea was 0.17 (95% CI, 0.08-0.38; P < 0.001), indicating much lower diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing diarrheal disease incidence. 相似文献
147.
Roy P Bonello L de Labriolle A Okabe T Pinto Slottow TL Steinberg DH Torguson R Smith K Xue Z Satler LF Kent KM Suddath WO Pichard AD Waksman R 《The American journal of cardiology》2008,102(3):292-297
Multiple studies comparing sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES) in patients with coronary artery disease have been performed. Despite these comparisons, it remains uncertain whether a differential in long-term efficacy and safety exists. Unselected patients treated exclusively with 1 drug-eluting stent type were enrolled in the Registry Experience at the Washington Hospital Center with Drug-Eluting Stents. There were 2,099 patients (3,766 lesions) treated with SES and 1,079 patients (1,850 lesions) treated with PES. Patients were followed at 30 days, 1 year, and 2 years for the clinical endpoints of death, myocardial infarction, target vessel revascularization, and definite and definite/probable stent thrombosis. Patients in the SES group had more dyslipidemia, history of congestive heart failure, and ostial lesions; patients treated with PES had more previous coronary artery bypass surgery, unstable angina, and type C lesions. At 2 years, unadjusted major adverse cardiac events (MACE) (22.6% vs 21.1%, p = 0.3) and target vessel revascularization (13.3% vs 11.2%, p = 0.1) were comparable. The incidence of definite stent thrombosis was higher in the SES group (1.8% vs 0.9%, p = 0.05) driven by early events. Similar results were seen after adjustment for baseline differences: MACE (hazard ratio 1.1, 95% confidence interval [CI] 0.9 to 1.3, p = 0.5), definite stent thrombosis (hazard ratio 2.3, 95% CI 1.0 to 5.2, p = 0.05), and target vessel revascularization (hazard ratio 1.1, 95% CI 0.9 to 1.4, p = 0.4). The incidence and rate of late stent thrombosis (>30 days) were similar (0.7% vs 0.5%, p = 0.4 and 0.24%/year, both groups, respectively). In conclusion, no major differential in long-term safety or efficacy was detected between SES and PES; both stent types were efficacious in reducing revascularization but were limited by a small continual increase in late stent thrombosis. 相似文献
148.
Steinberg DH Shah P Kinnaird T Pinto Slottow TL Roy PK Okabe T Bonello L de Labriolle A Smith KA Torguson R Xue Z Suddath WO Kent KM Satler LF Pichard AD Lindsay J Waksman R 《The American journal of cardiology》2008,102(2):160-164
For patients undergoing elective percutaneous coronary intervention (PCI), procedural anticoagulation with bivalirudin was previously shown to significantly reduce bleeding complications at the cost of a modest increase in ischemic events compared with unfractionated heparin (UFH) and glycoprotein IIb/IIIa inhibitors (GPIs). However, the excess bleeding in patients treated with UFH and GPIs may have been caused by excessively high UFH doses and increased activated clotting times. This study sought to determine the bleeding risk of targeted low-dose UFH with GPIs compared with bivalirudin in patients undergoing elective PCI. Of 1,205 patients undergoing elective PCI, 602 underwent PCI with adjunctive UFH and GPIs with the UFH dose targeted to an activated clotting time of approximately 250 seconds, and 603 patients matched for baseline characteristics underwent PCI with bivalirudin. Outcomes were analyzed for major bleeding (hematocrit decrease >15%, gastrointestinal bleed, or major hematoma) and 6-month major adverse cardiac events (death, myocardial infarction, and target-lesion revascularization). The maximum activated clotting time achieved was 261.7 +/- 61.6 seconds in the UFH/GPI group and 355.4 +/- 66.6 in the bivalirudin group (p <0.001). In-hospital major bleeding rates were similar between groups (1.8% UFH/GPI vs 1.7% bivalirudin; p = 0.83), as were transfusion requirements (1.2% UFH/GPI vs 0.5% bivalirudin; p = 0.61). The 6-month major adverse cardiac event rate was also similar between groups (9.5% UFH/GPI vs 9.0% bivalirudin; p = 0.81). In conclusion, there were no significant differences in major bleeding and 6-month major adverse cardiac events for patients undergoing elective PCI treated with targeted low-dose UFH and GPIs compared with those treated with bivalirudin. 相似文献
149.
Edouard Cheneau Daniel Canos Ellen Pinnow Andrew E Ajani Lowell F Satler Augusto D Pichard Kenneth M Kent Joseph Lindsay Ron Waksman 《Catheterization and cardiovascular interventions》2004,62(3):318-322
To determine the safety and efficacy, including the impact, on the late recurrence rate of an incremental gamma-radiation dose from 15 to 18 Gy, we report the 3-year clinical outcome of Washington Radiation for In-Stent Restenosis Trial for Long Lesions (Long WRIST). One hundred eighty patients with recurrent in-stent restenosis (ISR) were enrolled in the Long WRIST series and treated with (192)Ir with 1 month of antiplatelet therapy. Between 6 months and 3 years, the need for repeat revascularization was low and similar among the three groups. At 3 years, target lesion revascularization (TLR) and major adverse cardiac events (MACE) were less frequent in the 18 Gy group than in the 15 Gy group (P = 0.12 for TLR, P < 0.05 for MACE) and less frequent in the 15 Gy group as compared to the placebo group (P < 0.05 for TLR and MACE). At 3 years, a higher dose of 18 Gy with (192)Ir continues to improve the outcome of patients treated for ISR when compared to patients treated with 15 Gy or placebo. 相似文献
150.
Voronov E Shouval DS Krelin Y Cagnano E Benharroch D Iwakura Y Dinarello CA Apte RN 《Proceedings of the National Academy of Sciences of the United States of America》2003,100(5):2645-2650
Here, we describe that microenvironmental IL-1 beta and, to a lesser extent, IL-1 alpha are required for in vivo angiogenesis and invasiveness of different tumor cells. In IL-1 beta knockout (KO) mice, local tumor or lung metastases of B16 melanoma cells were not observed compared with WT mice. Angiogenesis was assessed by the recruitment of blood vessel networks into Matrigel plugs containing B16 melanoma cells; vascularization of the plugs was present in WT mice, but was absent in IL-1 beta KO mice. The addition of exogenous IL-1 into B16-containing Matrigel plugs in IL-1 beta KO mice partially restored the angiogenic response. Moreover, the incorporation of IL-1 receptor antagonist to B16-containing plugs in WT mice inhibited the ingrowth of blood vessel networks into Matrigel plugs. In IL-1 alpha KO mice, local tumor development and induction of an angiogenic response in Matrigel plugs was less pronounced than in WT mice, but significantly higher than in IL-1 beta KO mice. These effects of host-derived IL-1 alpha and IL-1 beta were not restricted to the melanoma model, but were also observed in DA/3 mammary and prostate cancer cell models. In addition to the in vivo findings, IL-1 contributed to the production of vascular endothelial cell growth factor and tumor necrosis factor in cocultures of peritoneal macrophages and tumor cells. Host-derived IL-1 seems to control tumor angiogenesis and invasiveness. Furthermore, the anti-angiogenic effects of IL-1 receptor antagonist, shown here, suggest a possible therapeutic role in cancer, in addition to its current use in rheumatoid arthritis. 相似文献