全文获取类型
收费全文 | 2719篇 |
免费 | 161篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 139篇 |
妇产科学 | 68篇 |
基础医学 | 305篇 |
口腔科学 | 37篇 |
临床医学 | 190篇 |
内科学 | 474篇 |
皮肤病学 | 52篇 |
神经病学 | 248篇 |
特种医学 | 98篇 |
外科学 | 435篇 |
综合类 | 51篇 |
预防医学 | 87篇 |
眼科学 | 165篇 |
药学 | 261篇 |
中国医学 | 18篇 |
肿瘤学 | 223篇 |
出版年
2023年 | 14篇 |
2022年 | 39篇 |
2021年 | 91篇 |
2020年 | 60篇 |
2019年 | 80篇 |
2018年 | 117篇 |
2017年 | 70篇 |
2016年 | 103篇 |
2015年 | 86篇 |
2014年 | 119篇 |
2013年 | 159篇 |
2012年 | 188篇 |
2011年 | 219篇 |
2010年 | 106篇 |
2009年 | 110篇 |
2008年 | 172篇 |
2007年 | 186篇 |
2006年 | 171篇 |
2005年 | 167篇 |
2004年 | 140篇 |
2003年 | 117篇 |
2002年 | 71篇 |
2001年 | 46篇 |
2000年 | 35篇 |
1999年 | 40篇 |
1998年 | 21篇 |
1997年 | 15篇 |
1996年 | 15篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 3篇 |
排序方式: 共有2889条查询结果,搜索用时 15 毫秒
101.
Thymoma and myotonic dystrophy: successful treatment with chemotherapy and radiation: case report and review of the literature 总被引:1,自引:0,他引:1
We present the case of a 42-year-old woman with myotonic dystrophy and thymoma. She was treated with combination chemotherapy followed by external beam radiation, and remains in remission 19 months after thymoma was diagnosed. The myotonic dystrophy is unchanged. Only six cases of this nature have been reported in the literature, and this patient is the first to be successfully treated with combined modality therapy. 相似文献
102.
Delivery of therapeutic levels of heparin and low-molecular-weight heparin through a pulmonary route 总被引:5,自引:0,他引:5
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Qi Y Zhao G Liu D Shriver Z Sundaram M Sengupta S Venkataraman G Langer R Sasisekharan R 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(26):9867-9872
Although heparin and low-molecular-weight heparins (LMWH) have been widely used clinically as anticoagulants, their broader use has been limited by the lack of noninvasive delivery methods for this class of molecules. In this study, we demonstrate an efficient, rapid, and reproducible delivery system for heparin through the lungs that is not confined to particles of a certain geometric or aerodynamic diameter. Importantly, blood levels after intrapulmonary administration of either heparin or LMWH were comparable to that of s.c. administration but are characterized by a more rapid onset of action (t(1/2) = 40 min vs. 2.5 h, respectively). Furthermore, we show in animal models, that inhaled heparin species efficiently inhibit diseases such as thrombosis and emphysema, and that the repetitive inhalation of formulated LMWH results in no observable toxicity from the delivery of reproducible systemic levels of heparin or LMWH. 相似文献
103.
Balakrishnan V Unnikrishnan AG Thomas V Choudhuri G Veeraraju P Singh SP Garg P Pai CG Devi RN Bhasin D Jayanthi V Premalatha N Chacko A Kar P Rai RR Rajan R Subhalal N Mehta R Mishra SP Dwivedi M Vinayakumar KR Jain AK Biswas K Mathai S Varghese J Ramesh H Alexander T Philip J Raj VV Vinodkumar A Mukevar S Sawant P Nair P Kumar H Sudhindran S Dhar P Sudheer OV Sundaram KR Tantri BV Singh D Nath TR 《JOP : Journal of the pancreas》2008,9(5):593-600
104.
Abozguia K Phan TT Shivu GN Maher AR Ahmed I Wagenmakers A Frenneaux MP 《European journal of heart failure》2008,10(7):652-657
AIM: We used Near Infrared Spectrophotometry (NIRS) during arterial occlusion to measure resting skeletal muscle oxygen consumption in chronic heart failure (CHF) patients and in age-matched healthy volunteers (HVs). METHODS: Fifteen CHF patients (ten males) and eleven HVs (six males) had echocardiographic evaluation followed by measurement of the oxygen consumption of the brachioradialis muscle using NIRS. This involved continuous measurement of the oxygenated haemoglobin concentration ([Oxy-Hb]) and deoxy-haemoglobin concentration ([Deoxy-Hb]) with an Oxiplex TS NIRS probe first under basal overnight fasted resting conditions followed by 1 min of forearm arterial occlusion. A linear decline was observed in [Oxy-Hb-Deoxy-Hb] during the arterial occlusion and the oxygen consumption rate was calculated from the initial slope observed. RESULTS: CHF patients were 59+/-2.8 years old with Left Ventricular Ejection Fraction (LVEF) 31%+/-2.2 and the HVs were 52+/-4.8 years old with LVEF 62%+/-2.5. The resting muscle oxygen consumption rate was significantly reduced in CHF patients versus HVs (0.04+/-0.01 mlO(2)/min/100 g versus 0.07+/-0.01 mlO(2)/min/100 g) p<0.005. CONCLUSIONS: There is a significant reduction in resting oxygen consumption per gram of tissue in skeletal muscle of patients with CHF. 相似文献
105.
Ganesh Manoharan Nico H J Pijls Norbert Lameire Katia Verhamme Guy R Heyndrickx Emanuele Barbato William Wijns Juraj Madaric Xanden Tielbeele Jozef Bartunek Bernard De Bruyne 《Journal of the American College of Cardiology》2006,47(3):620-625
OBJECTIVES: The purpose of this work was to establish the normal range of maximal renal hyperemic response in humans and to identify the ideal renal vasodilatory stimuli. BACKGROUND: Stenotic renovascular atherosclerosis is increasingly treated by percutaneous transluminal renal intervention but with an unpredictable outcome. This may be due to hemodynamically non-significant stenosis or the presence of irreversible damage to the glomerular circulation. We propose that the renovascular hyperemic response may help identify appropriate patients. METHODS: In 28 normotensive patients, quantitative angiographic measurements of the renal artery were obtained, and renal artery pressure and flow velocity were continuously recorded after various hyperemic agents. RESULTS: In a first group of 11 patients, a significant increase in renal artery average peak velocity (APV) was observed after intrarenal (IR) bolus injection of 600 microg isosorbide dinitrate (41 +/- 19%), 30 mg papaverine (50 +/- 34%), 50 microg dopamine (94 +/- 54%), 0.8 microg x kg(-1) fenoldopam (80 +/- 25%), and during IR infusion of 1 microg x kg(-1) x min(-1) fenoldopam (86 +/- 28%). A second group of 17 patients received intravenous infusion of dopamine (3, 5, 10, 20, 30, and 40 microg x kg(-1) x min(-1)). The 3 and 5 microg x kg(-1) x min(-1) of dopamine modestly reduced renal resistance index (RI) (-13 +/- 15% and -25 +/- 20%, respectively). At higher dosages, no further decline in RI was observed. No significant change in vessel diameter was observed before and after the administration of the pharmacological stimuli suggesting that changes in APV corresponded with changes in absolute renal blood flow. CONCLUSIONS: The normal renal flow reserve averages approximately 2 in humans with normal renal function. An IR bolus injection of 50 microg x kg(-1) of dopamine is the most convenient means to elicit maximal renal hyperemia. 相似文献
106.
Background:
One of the reasons that hip resurfacing and large head metal on metal (MOM) total hip arthroplasty (THA) became popular in Asia was the possible increased range of movement and thereby improved function of the hip joint. Due to concerns of MOM articulation an alternative bearing was sought. Hence, a shift from large head MOM to large head ceramic on ceramic (COC) was made. The aim of this study was to compare the functional outcome including range of motion (ROM) and dislocation rates following large head MOM and large head COC THA.Materials and Methods:
Retrospectively, 39 primary THA with large head MOM with a mean age of 56 years (range 36-72 years) and average followup of 54 months (range 38-70 months) were compared with 23 primary THA with large head COC bearing with a mean age of 48 years (range 36-68 years) and an average followup of 18 months (range 12-26 months). Functional outcome was assessed using the Modified Harris Hip Score. Dislocation rate and ROM were compared.Results:
Global ROM averaged 248 degrees with MOM group and 252 degrees with the COC group. One patient with metal bearing had dislocation at an average 3 year followup which required revision THA while there were no complications in the COC group. MHHS averaged 89 points in MOM and 94 in COC THR.Conclusion:
This study has shown that large head ceramic on ceramic THA is a good alternative to large head metal on metal THA with comparable dislocation rates and range of movements and without complications of metallosis in Asian patients. 相似文献107.
Estela M. Gierbolini-Norat Shaina D. Holman Peng Ding Shubham Bakshi Rebecca Z. German 《Dysphagia》2014,29(4):475-482
Feeding is a rhythmic behavior that consists of several component cycle types. How the timing of these cycles changes over a complete feeding sequence is not well known. To test the hypothesis that cycle frequency/duration changes as a function of time spent feeding, we examined complete feeding sequences in six infant pigs, using EMG of mylohyoid and thyrohyoid as cycle markers. We measured the instantaneous frequency of sucking and of swallowing cycles in 19 sequences. Each sequence contained three qualitatively distinctive phases of sucking frequency. Phase 1 started with cycles at a very high frequency and quickly dropped to a more constant level with low variation, which characterized phase 2. Phase 3 had a steady level of frequency but was interspersed with a number of high- or low-frequency cycles. Each phase differed from the others in patterns of within-phase variation and among-phase variation. Phase 2 had the least variation, and phase 3 had the largest range of frequencies. The number of sucks per swallow also differed among phases. These patterns, which characterize normative feeding, could indicate a physiologic basis in satiation. In human infant clinical studies, where data collection is often limited, these results indicated the utility of collecting data in different phases. Finally, these results can be used as a template or pattern with which to assess clinically compromised infants. 相似文献
108.
109.
Ian T. Meredith AM Darren L. Walters Nicolas Dumonteil Stephen G. Worthley Didier Tchétché Ganesh Manoharan Daniel J. Blackman Gilles Rioufol David Hildick-Smith Robert J. Whitbourn Thierry Lefèvre Rüdiger Lange Ralf Müller Simon Redwood Dominic J. Allocco Keith D. Dawkins 《Journal of the American College of Cardiology》2014
Background
Transcatheter aortic valve replacement provides results comparable to those of surgery in patients at high surgical risk, but complications can impact long-term outcomes. The Lotus valve, designed to improve upon earlier devices, is fully repositionable and retrievable, with a unique seal to minimize paravalvular regurgitation (PVR).Objectives
The prospective, single-arm, multicenter REPRISE II study (REpositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus Valve System: Evaluation of Safety and Performance) evaluated the transcatheter valve system for treatment of severe symptomatic calcific aortic valve stenosis.Methods
Patients (n = 120; aortic annulus 19 to 27 mm) considered by a multidisciplinary heart team to be at high surgical risk received the valve transfemorally. The primary device performance endpoint, 30-day mean pressure gradient, was assessed by an independent echocardiographic core laboratory and compared with a pre-specified performance goal. The primary safety endpoint was 30-day mortality. Secondary endpoints included safety/effectiveness metrics per Valve Academic Research Consortium criteria.Results
Mean age was 84.4 years, 57% of the patients were female, and 76% were New York Heart Association functional class III/IV. Mean aortic valve area was 0.7 ± 0.2 cm2. The valve was successfully implanted in all patients, with no cases of valve embolization, ectopic valve deployment, or additional valve implantation. All repositioning (n = 26) and retrieval (n = 6) attempts were successful; 34 patients (28.6%) received a permanent pacemaker. The primary device performance endpoint was met, because the mean gradient improved from 46.4 ± 15.0 mm Hg to 11.5 ± 5.2 mm Hg. At 30 days, the mortality rate was 4.2%, and the rate of disabling stroke was 1.7%; 1 (1.0%) patient had moderate PVR, whereas none had severe PVR.Conclusions
REPRISE II demonstrates the safety and effectiveness of the Lotus valve in patients with severe aortic stenosis who are at high surgical risk. The valve could be positioned successfully with minimal PVR. (REPRISE II: REpositionable Percutaneous Replacement of Stenotic Aortic Valve Through Implantation of Lotus™ Valve System - Evaluation of Safety and Performance; NCT01627691) 相似文献110.
Sudha Sazawal Rekha Chaubey Pawandeep Kaur Sunita Chikkara Bijender Kumar Sameer Bakshi L. S. Arya Vinod Raina Alakananda Das Gupta Renu Saxena 《Indian journal of hematology & blood transfusion》2014,30(4):219-225
Genetic polymorphisms in the methylene tetrahydrofolate reductase (MTHFR) gene have been associated with the development of acute leukemias and various malignancies. The role of MTHFR polymorphism in the development of pediatric acute lymphoblastic leukemia (ALL) has been extensively studied among north Indians in various settings, yet its association with acute leukemias remains unresolved. To evaluate the relationship between functional MTHFR polymorphisms, C677T and A1298C and possible effect on risk of ALL in adults and children in North Indian population by comparing them with healthy controls. DNA was isolated from peripheral blood of 184 ALL patients (33 adults, 151 children) and 155 controls and analyzed by a PCR-restriction fragment length polymorphism assay. The frequency of MTHFR 677CT and 1298 AC genotypes were significantly lower among adult ALL cases when compared to the controls. We found a 1.74-fold reduced risk of ALL in individuals with 1298AC polymorphic variant and a 9.17-fold decreased risk of adult ALL. However, no statistically significant difference was evident between the above polymorphisms and susceptibility to ALL in children. Polymorphisms in the MTHFR gene possibly modulate risk of ALL in north Indian adults but not in children, although larger studies are needed. 相似文献