全文获取类型
收费全文 | 3624篇 |
免费 | 179篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 69篇 |
妇产科学 | 80篇 |
基础医学 | 473篇 |
口腔科学 | 67篇 |
临床医学 | 339篇 |
内科学 | 914篇 |
皮肤病学 | 24篇 |
神经病学 | 598篇 |
特种医学 | 120篇 |
外科学 | 364篇 |
综合类 | 8篇 |
一般理论 | 2篇 |
预防医学 | 172篇 |
眼科学 | 35篇 |
药学 | 212篇 |
中国医学 | 16篇 |
肿瘤学 | 257篇 |
出版年
2023年 | 29篇 |
2022年 | 60篇 |
2021年 | 91篇 |
2020年 | 59篇 |
2019年 | 83篇 |
2018年 | 100篇 |
2017年 | 76篇 |
2016年 | 107篇 |
2015年 | 100篇 |
2014年 | 148篇 |
2013年 | 180篇 |
2012年 | 268篇 |
2011年 | 239篇 |
2010年 | 151篇 |
2009年 | 135篇 |
2008年 | 243篇 |
2007年 | 239篇 |
2006年 | 234篇 |
2005年 | 250篇 |
2004年 | 221篇 |
2003年 | 192篇 |
2002年 | 191篇 |
2001年 | 26篇 |
2000年 | 20篇 |
1999年 | 27篇 |
1998年 | 56篇 |
1997年 | 29篇 |
1996年 | 16篇 |
1995年 | 32篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 16篇 |
1991年 | 9篇 |
1990年 | 18篇 |
1989年 | 12篇 |
1988年 | 8篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 13篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 18篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1976年 | 3篇 |
1974年 | 8篇 |
1973年 | 5篇 |
1970年 | 3篇 |
排序方式: 共有3827条查询结果,搜索用时 15 毫秒
991.
Sarto P Balducci E Balconi G Fiordaliso F Merlo L Tuzzato G Pappagallo GL Frigato N Zanocco A Forestieri C Azzarello G Mazzucco A Valenti MT Alborino F Noventa D Vinante O Pascotto P Sartore S Dejana E Latini R 《Journal of cardiac failure》2007,13(9):701-708
BackgroundThe enhancement of circulating endothelial progenitor cells (EPCs) obtained by exercise training can be beneficial to patients with cardiac disease. Changes in the levels and differentiation of CD34pos/KDRpos EPCs, as well as the plasma concentration of vascular endothelial growth factor (VEGF) and stromal cell-derived factor (SDF)-1 EPC-mobilizing cytokines, were evaluated in patients with chronic heart failure after 8 weeks of supervised aerobic training (SAT) and 8 weeks of subsequent discontinued SAT (DSAT).Methods and ResultsThe levels of circulating EPC and EPC differentiation potential of 22 patients who underwent SAT were studied by fluorescence-activated cell sorter analysis and colony forming-unit assay, respectively. The plasma levels of VEGF and SDF-1 were measured by enzyme-linked immunosorbent assay. In response to SAT, the levels of both EPC and VEGF/SDF-1 markedly increased (P < .001 vs baseline) but returned to the baseline levels after DSAT. A similar change was observed with the EPC clonogenic potential, but on DSAT the baseline level was incompletely attained.ConclusionsIn response to SAT, patients with chronic heart failure show enhanced EPC levels and clonogenic potential that is mirrored by increased plasma VEGF and SDF-1 levels. DSAT can interfere with the maintenance of training-acquired VEGF/SDF-1-related EPC levels and clonogenic potential. 相似文献
992.
ALS multidisciplinary clinic and survival 总被引:1,自引:1,他引:0
Zoccolella S Beghi E Palagano G Fraddosio A Guerra V Lepore V Simone IL Lamberti P Serlenga L Logroscino G 《Journal of neurology》2007,254(8):1107-1112
BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease affecting motorneurons, for which there is no effective cure. Because of the multifactorial nature of impairment and disablity in ALS, multidisciplinary clinics (MDC) have been recently introduced in the management of ALS patients; their effects on survival remain, however, largely debated. OBJECTIVE: To compare survival of ALS patients who received their care at MDC with that of patients followed by general neurology clinics. METHODS: Source of the study was a prospective population-based registry of ALS established in Puglia, Southern Italy, in 1997. We examined survival of 126 out of 130 incident ALS cases that were diagnosed during the period 1998-99. RESULTS: 84 patients (67%) were enrolled and followed by MDC and the remaining 42 (33%) by general neurological clinics. No difference in median survival time from the diagnosis was observed between patients followed by ALS multidisciplinary (17.6 months) and general clinics (18 months). No beneficial effect was present among bulbar onset ALS (11.7 versus 23 months). In multivariate analysis management by ALS MDC was associated with only a 10% increase in survival probability at 12 months (HR: 0.91; 95%CI: 0.44-1.89; p = 0.9). CONCLUSIONS: In this population-based series, we found that in Southern Italy management of ALS by multidisciplinary clinics does not improve survival, regardless of site of symptoms onset. 相似文献
993.
994.
Attanasio A Argiriadou V Sandri G Diomedi M 《International journal of cardiology》2007,116(2):e34-e38
We report the case of a young anorexic woman who suffered a sudden loss of consciousness with convulsions, diagnosed as epilepsy associated with a migrational disorder, as documented at MRI. Standard 12-lead ECG showed a prolonged QT interval. Biochemical tests revealed a severe hypokalemia. Continuous 24-h ECG recording detected a ventricular tachycardia in torsades de pointes inducing a syncopal convulsive attack that seemed to be related to oral Cisapride assumption for dyspepsia. Discontinuation of cisapride and normalization of kalemia caused disappearance of both ECG abnormalities and loss of consciousness episodes. Syncope is a condition often misdiagnosed as epileptic seizures. 相似文献
995.
Purpose A remarkable incidence of failures after stapled axopexy (SA) for hemorrhoids has been recently reported by several papers,
with an incomplete resection of the prolapsed tissue, due to the limited volume of the stapler casing as possible cause. The
stapled transanal rectal resection (STARR) was demonstrated to successfully cure the association of rectal prolapse and rectocele
by using two staplers. The aim of this randomized study was to evaluate the incidence of residual disease after SA and STARR
in patients affected by prolapsed hemorrhoids associated with rectal prolapse.
Methods Sixty-eight patients were selected on the basis of validated constipation and continence scorings, clinical examination, colonoscopy,
anorectal manometry, and defecography and randomized: 34 underwent a SA and 34 a STARR operation. The operated patients were
followed-up with clinical examination, visual analog scale for postoperative pain, a satisfaction index, and defecography.
Results At a mean follow-up of 8.1 +/− 2.0 and 7.9 +/− 1.8 months for the SA and STARR groups, respectively, the incidence of residual
disease was significantly higher in the first group (29.4 vs 5.9 in the STARR group, p = 0.007), while a significantly lower incidence of residual skin-tags was found after STARR (23.5% vs 58.8 after SA, p = 0.03). All patients with residual disease showed prolapsed tissue over half the length of the anal dilator at the time
of the operation. Operative time and incidence of transient fecal urgency were significantly higher in the STARR group (with
p = 0.001 and 0.08, respectively), while SA was followed by a significantly higher incidence of poor results at the overall
patient satisfaction index (p = 0.04). No significant differences were found in hospital stay, operative complications, postoperative pain, time to return
to normal activity, continence, and constipation scores. All the defecographic parameters significantly improved after STARR,
while SA was followed only by a trend to a reduction of rectal prolapse.
Conclusions STARR provides a more complete resection of the prolapsed tissue than SA in patients with association of prolapsed hemorrhoids
and rectal prolapse with equal morbidity and significantly lower incidence of residual disease and skin-tags. The anal dilator
can be used for selecting the surgical technique. 相似文献
996.
Russo G Calzi D Martini M Rossi ML Fesce R Prigioni I 《The European journal of neuroscience》2007,25(3):695-704
The complement of voltage-dependent K+ currents was investigated in hair cells of the frog crista ampullaris. The currents were recorded in transversal slices of the peripheral, intermediate and central regions of the crista by applying the patch clamp technique to cells located at different positions in the slices. Voltage-clamp recordings confirmed that cells located in each region have a distinctive complement of K+ channels. Detailed investigation of the currents in each region revealed that the complement of K+ channels in intermediate and central regions showed no variations among cells, whereas peripheral hair cells differed in the expression of two classes of A-type currents. These currents showed different kinetics of inactivation as well as steady-state inactivation properties. We termed these currents fast I(A) and slow I(A) based on their inactivation speed. The magnitude of both currents exhibited a significant gradient along the transversal axis of the peripheral regions. Fast I(A) magnitude was maximal in cells located in the external zone of the crista slice and decreased gradually to become very small in the median zone (centre) of the section, while the gradient of slow I(A) magnitude was reversed. A-type currents appear to act as a transient buffer that opposes hair cell depolarization induced by positive current injections. However, fast I(A) is partially active at the cell resting potential, while slow I(A) can be recruited only following large hyperpolarizations. Thus, two types of A currents are differentially distributed in vestibular hair cells and have different roles in shaping receptor potential. 相似文献
997.
Paciaroni M Hennerici M Agnelli G Bogousslavsky J 《Cerebrovascular diseases (Basel, Switzerland)》2007,24(2-3):170-182
Over the past decade, statins have been proven to significantly decrease coronary events in primary and secondary prevention of coronary artery disease. Recent clinical trials have indicated that statins significantly reduce stroke risk in patients with vascular disease. The Cholesterol Treatment Trialists' Collaborators in a meta-analysis including 90,056 patients found that the use of statins determined a significant 17% proportional reduction in the incidence of first-ever stroke of any type per 1 mmol/l low-density lipoprotein (LDL) cholesterol reduction. During an average of 5 years of treatment, the reduction in the overall incidence of stroke was about one sixth per 1 mmol/l LDL cholesterol decrease meaning that 8 fewer participants have any stroke per 1,000 among those with preexisting coronary artery disease at baseline, compared with 5 fewer per 1,000 among the participants with no such history. It is not known whether these findings might be due to the cholesterol reduction effect of statins or to pleiotropic effects of statins, such as improved endothelial function, decreased platelet aggregability, and reduced vascular inflammation. In secondary prevention of stroke, the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) study found that treatment with atorvastatin reduced the risk of recurrent cerebrovascular events in patients with recent stroke or transient ischemic attack but no history of heart disease. Combining the results of patients with no history of heart disease from the SPARCL study and Heart Protection Study in a mini meta-analysis, compared with placebo, statins were associated with a barely nonsignificant difference in recurrent stroke (OR = 0.87, 95% CI = 0.75-1.01, p = 0.07) and a significant difference in the occurrence of major vascular events (OR = 0.78, 95% CI = 0.68-0.88, p = 0.0001) at final follow-up. 相似文献
998.
Basile A Lupattelli T Magnano M Giulietti G Privitera G Battaglia G Monaca V Ettorre G 《Cardiovascular and interventional radiology》2007,30(1):126-128
We present a case of a 73-year-old man in whom a celiac trunk aneurysm close to the hepato-splenic bifurcation was discovered
and treated by using celiac–hepatic stent-grafts implantation and splenic artery embolization. 相似文献
999.
1000.
PURPOSE: To evaluate diagnostic sensitivity of the pulmonary nodules computer-aided detection (CAD) in computed tomography. To analyze parameters that modify CAD performance. We made a critical analysis of the literature, and we described CAD sensitivity. Moreover, we compared CAD and CAD plus radiologist sensitivity in detection of pulmonary nodules, and we compared different acquisition techniques (thin slice vs thick slice and low dose vs normal dose). MATERIALS AND METHODS: We used as major data sources the medical literature database of PubMed and MEDLINE, where we searched for articles in English language published from January 2001 to November 2006. We included studies that used spiral or multidetector row CT for CAD. RESULTS: Twenty studies met the inclusion criteria containing a total of more than 827 patients and 2717 pulmonary nodules detected by CAD. We observed an overall sensitivity of 79% for the CAD and of 92% for CAD plus radiologist; CAD sensitivity was 80% and 74% for thin slice and thick slice protocols, respectively. CONCLUSIONS: Results of our study suggest that CAD technique is an accurate tool in detection of pulmonary nodules, by working as useful second look for the physician. Sensitivity becomes higher by using it together with radiologist. Actually, the main limitation about the use of CAD to be solved is represented by the persistent high false-positive rate. 相似文献