全文获取类型
收费全文 | 5749篇 |
免费 | 300篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 27篇 |
儿科学 | 450篇 |
妇产科学 | 232篇 |
基础医学 | 618篇 |
口腔科学 | 65篇 |
临床医学 | 432篇 |
内科学 | 1079篇 |
皮肤病学 | 85篇 |
神经病学 | 478篇 |
特种医学 | 180篇 |
外科学 | 930篇 |
综合类 | 141篇 |
一般理论 | 2篇 |
预防医学 | 354篇 |
眼科学 | 297篇 |
药学 | 325篇 |
中国医学 | 27篇 |
肿瘤学 | 343篇 |
出版年
2023年 | 24篇 |
2022年 | 68篇 |
2021年 | 148篇 |
2020年 | 86篇 |
2019年 | 106篇 |
2018年 | 162篇 |
2017年 | 90篇 |
2016年 | 128篇 |
2015年 | 144篇 |
2014年 | 211篇 |
2013年 | 254篇 |
2012年 | 407篇 |
2011年 | 414篇 |
2010年 | 264篇 |
2009年 | 214篇 |
2008年 | 347篇 |
2007年 | 335篇 |
2006年 | 293篇 |
2005年 | 301篇 |
2004年 | 300篇 |
2003年 | 241篇 |
2002年 | 236篇 |
2001年 | 121篇 |
2000年 | 115篇 |
1999年 | 80篇 |
1998年 | 56篇 |
1997年 | 36篇 |
1996年 | 37篇 |
1995年 | 24篇 |
1994年 | 28篇 |
1993年 | 31篇 |
1992年 | 60篇 |
1991年 | 59篇 |
1990年 | 60篇 |
1989年 | 39篇 |
1988年 | 35篇 |
1987年 | 58篇 |
1986年 | 41篇 |
1985年 | 32篇 |
1984年 | 34篇 |
1983年 | 42篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 21篇 |
1979年 | 29篇 |
1977年 | 16篇 |
1976年 | 15篇 |
1974年 | 16篇 |
1970年 | 14篇 |
1969年 | 15篇 |
排序方式: 共有6065条查询结果,搜索用时 14 毫秒
51.
Menon AK Albes JM Oberhoff M Karsch KR Ziemer G 《The Annals of thoracic surgery》2002,73(5):1418-1423
BACKGROUND: Minimally invasive direct coronary artery bypass is an established clinical procedure for revascularization of the left anterior descending coronary artery. Mechanical stabilization and temporary occlusion is currently used to perform the anastomosis of the internal thoracic artery to the left anterior descending coronary artery. However, critical reduction of cardiac function can occur as a result of temporary ischemia. The purpose of this study was to evaluate whether ischemic sequelae can be avoided by using temporary intraluminal shunts and whether this alters early outcome. METHODS: Thirty-five patients underwent minimally invasive direct coronary artery bypass revascularization using a mechanical stabilizer. In group A (n = 20), the anastomotic site was temporarily occluded by tourniquets. In group B (n = 15), temporary intraluminal shunts were inserted into the anastomotic site without any occlusion of the left anterior descending coronary artery. Anastomosis of the internal thoracic artery to the left anterior descending coronary artery was performed in an identical fashion. A Swan-Ganz catheter was inserted, and transesophageal echocardiographic measurements were obtained for analysis of left ventricular (LV) function. Regional wall motion, cardiac index, stroke volume index, systolic and diastolic LV diameters, and fractional area change were measured during four periods: at the start of the operation (baseline), placement of the stabilizer (stabilization), left anterior descending coronary artery occlusion (occlusion) or insertion of temporary intraluminal shunts (shunt), and 30 minutes after reperfusion (reperfusion). Angiograms were obtained 4 to 6 days postoperatively. RESULTS: In group A, LV performance, cardiac index, stroke volume index, and fractional area change decreased during occlusion whereas systolic diameters increased. Almost two myocardial segments per patient developed severe hypokinesia in the perfusion area. These changes disappeared after 30 minutes of reperfusion, with increased LV function. In group B, LV function remained stable whereas hypokinetic wall motion was only detected in 2 patients. Early angiograms revealed 90% of the grafts were patent in group A versus 100% in group B. The need for percutaneous intervention during the first 6 months was 20% in group A versus 6.7% in group B. CONCLUSIONS: The use of temporary intraluminal shunts resulted in reduced acute ischemia and revealed wall motion abnormalities and maintained LV function. Furthermore, this technique suggests an improvement of early graft patency and a lower reintervention rate within the first 6 postoperative months. Thus, use of temporary intraluminal shunts appears to be superior to the occlusion technique early after minimally invasive direct coronary artery bypass procedures. 相似文献
52.
Ronald S. Boris Daniel Eun Akshay Bhandari Kathryn Lyall Mahendra Bhandari Craig Rogers Osama Alassi Mani Menon 《Journal of robotic surgery》2007,1(3):185-189
A potassium-titanyl-phosphate (KTP) laser through robotic endo-wrist instrument has been evaluated as an ablative and hemostatic
tool in robotic assisted laparoscopic partial nephrectomy (RALPN). Ten RALPN were performed in five domestic female pigs.
The partial nephrectomies were performed with bulldog clamping of the pedicle. Flexible glass fiber carrying 532-nm green
light laser was used through a robotic endowrist instrument in two cases. Power usage from 4 to 10 W was tested. The laser
probe was explored both as a cutting knife and for hemostasis. The pelvicalyceal system was closed with a running suture.
Partial nephrectomies using KTP laser were performed without complications. Mean operative times and warm ischemia times for
laser cases were 96 and 18 min, respectively. Mean estimated blood loss was 60 ml compared with 50 ml for non-laser cases.
Complete hemostasis with the laser alone could be achieved with a power of 4 W and was found to be effective. In our hands
the laser fiber powered up to 10 W was not effective as a quick cutting agent. Histopathologic analysis of the renal remnant
revealed a cauterized surface effect with average laser penetration depth less than 1 mm and minimal surrounding cellular
injury. The new robotic endowrist instrument carrying flexible glass fiber transmitting 532-nm green light laser is a useful
addition to the armamentarium of the robotic urologic setup. Its control by the console surgeon enables quicker and more complete
hemostasis of the cut surface in renal sparing surgery using a porcine model. Histologically proven lased depth of less than
1 mm suggests minimal parenchyma damage in an acute setting. Laser application as a cutting agent, however, requires further
investigation with interval power settings beyond the limits of this preliminary study. We estimate that effective cutting
should be possible with a setting lower than traditionally recommended for solid organs. 相似文献
53.
Mridu Paban Nath Saurabh Gupta Usha Kiran Sandeep Chauhan Naresh Dhawan 《Acta anaesthesiologica Taiwanica》2011,49(3):114-115
A 45-year-old patient with known history of Aortic arch aneurysm presented in the emergency ward with features of rupture of the aneurysm into the left lung with compressive signs in the pulmonary parenchyma. Diagnosis was confirmed by magnetic resonance imaging. The patient underwent repair of thoracic aortic aneurysm with left upper lobectomy under general anesthesia and cardio-pulmonary bypass support. Transesophageal echocardiography (TEE) was used for an intraoperative monitoring. While imaging the thoracic aorta with TEE was underway, we accidentally visualized an image that was confirmed to be the spinal cord. So, in this article we discuss how the spinal cord monitoring can be made possible with TEE. 相似文献
54.
Sampling density compensation in MRI: rationale and an iterative numerical solution. 总被引:7,自引:0,他引:7
Data collection of MRI which is sampled nonuniformly in k-space is often interpolated onto a Cartesian grid for fast reconstruction. The collected data must be properly weighted before interpolation, for accurate reconstruction. We propose a criterion for choosing the weighting function necessary to compensate for nonuniform sampling density. A numerical iterative method to find a weighting function that meets that criterion is also given. This method uses only the coordinates of the sampled data; unlike previous methods, it does not require knowledge of the trajectories and can easily handle trajectories that "cross" in k-space. Moreover, the method can handle sampling patterns that are undersampled in some regions of k-space and does not require a post-gridding density correction. Weighting functions for various data collection strategies are shown. Synthesized and collected in vivo data also illustrate aspects of this method. 相似文献
55.
Al Duraihimh H Ghamdi G Moussa D Shaheen F Mohsen N Sharma U Stephan A Alfie A Alamin M Haberal M Saeed B Kechrid M Al-Sayyari A 《Transplantation》2008,85(6):840-843
OBJECTIVE: To study the pregnancy and offspring outcomes in postrenal transplant recipients. METHODS: This is a retrospective case-note review study investigating the outcome of 234 pregnancies in 140 renal transplant recipients from five different Middle Eastern countries. RESULTS: Of the overall pregnancies 74.4% were successful albeit with high prevalences of preterm and Caesarean deliveries (40.8% and 53%, respectively). The mean serum creatinine did not rise significantly during pregnancy in the group as a whole but did so in patients who had serum creatinine of or above 150 micromol/L at the beginning of their pregnancies. The mean birth weight was (2,458 g) with 41.3% of the newborns being of low birth weight (<2,500 g). The prevalences of stillbirths were 7.3% and of spontaneous abortion was 19.3%. Preeclampsia and gestational diabetes were observed in 26.1% and 2% of pregnancies, respectively. CONCLUSIONS: In the presence of good allograft function, the majority of pregnancies in renal transplant recipients have a good outcome but with increased incidence of preeclampsia, reduced gestational age, and low birth weights. Patients with baseline serum creatinine of above 150 micromol/L have an increased risk of allograft dysfunction resulting from the pregnancy. 相似文献
56.
57.
Inflammation in human brain injury: intracerebral concentrations of IL-1alpha, IL-1beta, and their endogenous inhibitor IL-1ra 总被引:2,自引:0,他引:2
Hutchinson PJ O'Connell MT Rothwell NJ Hopkins SJ Nortje J Carpenter KL Timofeev I Al-Rawi PG Menon DK Pickard JD 《Journal of neurotrauma》2007,24(10):1545-1557
Following traumatic brain injury (TBI), cascades of inflammatory processes occur. Laboratory studies implicate the cytokines interleukin-1alpha (IL-1alpha) and IL-1beta in the pathophysiology of TBI and cerebral ischemia, whilst exogenous and endogenous interleukin-1 receptor antagonist (IL-1ra) is neuroprotective. We analyzed IL-1alpha, IL-1beta, and IL-1ra in brain microdialysates (100-kDa membrane) in 15 TBI patients. We also analyzed energy-related molecules (glucose, lactate, pyruvate, glutamate, and the lactate/pyruvate ratio) in these brain microdialysates. Mean of mean (+/-SD) in vitro microdialysis percentage recoveries (extraction efficiencies) were IL-1alpha 19.7+/-7.6%, IL-1beta 23.9+/-10.5%, and IL-1ra 20.9+/-6.3%. In the patients' brain microdialysates, mean of mean cytokine concentrations (not corrected for percentage recovery) were IL-1alpha 5.6+/-14.8 pg/mL, IL-1beta 10.4+/-14.7 pg/mL, and IL-1ra 2796+/-2918 pg/mL. IL-1ra was consistently much higher than IL-1alpha and IL-1beta. There were no significant relationships between IL-1 family cytokines and energy-related molecules. There was a significant correlation between increasing IL-1beta and increasing IL-1ra (Spearman r=0.59, p=0.028). There was also a significant relationship between increasing IL-1ra and decreasing intracranial pressure (Spearman r=-0.57, p=0.041). High concentrations of IL-1ra, and also high IL-1ra/IL-1beta ratio, were associated with better outcome (Mann Whitney, p=0.018 and p=0.0201, respectively), within these 15 patients. It is unclear whether these IL-1ra concentrations are sufficient to antagonize the effects of IL-1beta in vivo. This study demonstrates feasibility of our microdialysis methodology in recovering IL-1 family cytokines for assessing their inter-relationships in the injured human brain, and suggests a neuroprotective role for IL-1ra. It remains to be seen whether exogenous IL-1ra or other agents can be used to manipulate cytokine levels in the brain, for potential therapeutic effect. 相似文献
58.
Guillaume Ploussard Alberto Briganti Alexandre de la Taille Alexander Haese Axel Heidenreich Mani Menon Tullio Sulser Ashutosh K. Tewari James A. Eastham 《European urology》2014
Context
Pelvic lymph node dissection (PLND) in prostate cancer is the most effective method for detecting lymph node metastases. However, a decline in the rate of PLND during radical prostatectomy (RP) has been noted. This is likely the result of prostate cancer stage migration in the prostate-specific antigen-screening era, and the introduction of minimally invasive approaches such as robot-assisted radical prostatectomy (RARP).Objective
To assess the efficacy, limitations, and complications of PLND during RARP.Evidence acquisition
A review of the literature was performed using the Medline, Scopus, and Web of Science databases with no restriction of language from January 1990 to December 2012. The literature search used the following terms: prostate cancer, radical prostatectomy, robot-assisted, and lymph node dissection.Evidence synthesis
The median value of nodal yield at PLND during RARP ranged from 3 to 24 nodes. As seen in open and laparoscopic RP series, the lymph node positivity rate increased with the extent of dissection during RARP. Overall, PLND-only related complications are rare. The most frequent complication after PLND is symptomatic pelvic lymphocele, with occurrence ranging from 0% to 8% of cases. The rate of PLND-associated grade 3–4 complications ranged from 0% to 5%. PLND is associated with increased operative time. Available data suggest equivalence of PLND between RARP and other surgical approaches in terms of nodal yield, node positivity, and intraoperative and postoperative complications.Conclusions
PLND during RARP can be performed effectively and safely. The overall number of nodes removed, the likelihood of node positivity, and the types and rates of complications of PLND are similar to pure laparoscopic and open retropubic procedures. 相似文献59.
Praful Ravi Pierre I. Karakiewicz Florian Roghmann Giorgio Gandaglia Toni K. Choueiri Mani Menon Rana R. McKay Paul L. Nguyen Jesse D. Sammon Shyam Sukumar Briony Varda Steven L. Chang Adam S. Kibel Maxine Sun Quoc-Dien Trinh 《Urologic oncology》2014,32(8):1333-1340
ObjectiveTo examine the burden of mental health issues (MHI), namely anxiety, depressive disorders, and suicide, in a population-based cohort of older men with localized prostate cancer and to evaluate associations with primary treatment modality.Patients and methodsA total of 50,856 men, who were 65 years of age or older with clinically localized prostate cancer diagnosed between 1992 and 2005 and without a diagnosis of mental illness at baseline, were abstracted from the Surveillance, Epidemiology, and End Results–Medicare database. The primary outcome of interest was the development of MHI (anxiety, major depressive disorder, depressive disorder not elsewhere classified, neurotic depression, adjustment disorder with depressed mood, and suicide) after the diagnosis of prostate cancer.ResultsA total of 10,389 men (20.4%) developed MHI during the study period. Independent risk factors for MHI included age≥75 years (hazard ratio [HR] = 1.29); higher comorbidity (Charlson comorbidity index≥3, HR = 1.63); rural hospital location (HR = 1.14); being single, divorced, or widowed (HR = 1.12); later year of diagnosis (HR = 1.05); and urinary incontinence (HR = 1.47). Black race (HR = 0.79), very high-income status (HR = 0.87), and definitive treatment (radical prostatectomy [RP], HR = 0.79; radiotherapy [RT], HR= 0.85, all P<0.001) predicted a lower risk of MHI. The rates of MHI at 10 years were 29.7%, 29.0%, and 22.6% in men undergoing watchful waiting (WW), RT, and RP, respectively.ConclusionOlder men with localized prostate cancer had a significant burden of MHI. Men treated with RP or RT were at a lower risk of developing MHI, compared with those undergoing WW, with median time to development of MHI being significantly greater in those undergoing RP compared with those undergoing RT or WW. 相似文献
60.
Wesley A. Papenfuss MD FACS Moshim Kukar MD Jacqueline Oxenberg DO Kristopher Attwood MA PhD Steven Nurkin MD MS Usha Malhotra MD Neal W. Wilkinson MD FACS 《Annals of surgical oncology》2014,21(9):3008-3014