全文获取类型
收费全文 | 5369篇 |
免费 | 509篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 203篇 |
妇产科学 | 118篇 |
基础医学 | 731篇 |
口腔科学 | 70篇 |
临床医学 | 628篇 |
内科学 | 1109篇 |
皮肤病学 | 38篇 |
神经病学 | 546篇 |
特种医学 | 155篇 |
外科学 | 798篇 |
综合类 | 82篇 |
一般理论 | 2篇 |
预防医学 | 516篇 |
眼科学 | 364篇 |
药学 | 338篇 |
中国医学 | 1篇 |
肿瘤学 | 172篇 |
出版年
2022年 | 38篇 |
2021年 | 65篇 |
2020年 | 42篇 |
2019年 | 83篇 |
2018年 | 84篇 |
2017年 | 59篇 |
2016年 | 63篇 |
2015年 | 86篇 |
2014年 | 119篇 |
2013年 | 198篇 |
2012年 | 284篇 |
2011年 | 307篇 |
2010年 | 166篇 |
2009年 | 156篇 |
2008年 | 282篇 |
2007年 | 322篇 |
2006年 | 306篇 |
2005年 | 333篇 |
2004年 | 307篇 |
2003年 | 318篇 |
2002年 | 256篇 |
2001年 | 131篇 |
2000年 | 126篇 |
1999年 | 114篇 |
1998年 | 84篇 |
1997年 | 52篇 |
1996年 | 43篇 |
1995年 | 61篇 |
1994年 | 48篇 |
1993年 | 43篇 |
1992年 | 86篇 |
1991年 | 80篇 |
1990年 | 58篇 |
1989年 | 69篇 |
1988年 | 78篇 |
1987年 | 84篇 |
1986年 | 59篇 |
1985年 | 76篇 |
1984年 | 36篇 |
1983年 | 44篇 |
1982年 | 29篇 |
1979年 | 42篇 |
1978年 | 51篇 |
1977年 | 42篇 |
1976年 | 31篇 |
1975年 | 40篇 |
1974年 | 40篇 |
1973年 | 38篇 |
1972年 | 35篇 |
1971年 | 31篇 |
排序方式: 共有5888条查询结果,搜索用时 15 毫秒
1.
Paul C. Willems Leon Elmans Patricia G. Anderson Wilco C. H. Jacobs Dick B. van der Schaaf Marinus de Kleuver 《European spine journal》2006,15(10):1487-1494
The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, χ
2 test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery. 相似文献
2.
Saifudin Rashiq Diane Edlund Bruce D Dick 《BMC medical informatics and decision making》2006,6(1):8-6
Background
There are no published utilities for the post-anesthesia state obtained by the standard gamble method (SG). 相似文献3.
Willemijn A K M Windt Atsua Tahara Alex C A Kluppel Dick de Zeeuw Robert H Henning Richard P E van Dokkum 《Journal of the renin-angiotensin-aldosterone system》2006,7(4):217-224
INTRODUCTION: Vasopressin, mainly through the V1a-receptor, is thought to be a major player in the maintenance of hyperfiltration. Its inhibition could therefore lead to a decrease in progression of chronic renal failure. To this end, the effect of the vasopressin V1a-receptor-selective antagonist, YM218, was studied on proteinuria and focal glomerulosclerosis in early and late intervention after 5/6 nephrectomy in rats, and compared with an angiotensin-converting enzyme inhibitor (ACE-I). MATERIALS AND METHODS: After 5/6 nephrectomy, early intervention was performed between week 2 and 10 thereafter with the V1a-receptor-selective antagonist (VRA, 10 mg/kg/day, n=10), enalapril (ACE-I, 10 mg/kg/day, n=9), or vehicle (n=8). Late intervention was performed in another group between week 6 and 12 with VRA (10 mg/kg/day, n=7), lisinopril (ACE-I, 5 mg/kg/day, n=7), or vehicle (n=7). RESULTS: In early intervention, proteinuria and focal glomerulosclerosis were significantly decreased by VRA compared to vehicle (44+7% and 59+8% respectively). ACE-I significantly decreased proteinuria (67+7%) and a trend towards a decrease in focal glomerulosclerosis was observed (30+18%). In late intervention, VRA did not decrease proteinuria and focal glomerulosclerosis compared to vehicle (21+20% and 0%, respectively), ACE-I significantly lowered proteinuria (92+2%) and a focal glomerulosclerosis (69+1%) lowering trend was observed. CONCLUSION: These results indicate that VRA may protect against early progression of renal injury after 5/6 nephrectomy, whereas its effectiveness seems limited in established renal damage. 相似文献
4.
N Diehm A Shang A Silvestro D-D Do F Dick J Schmidli F Mahler I Baumgartner 《European journal of vascular and endovascular surgery》2006,31(1):59-63
OBJECTIVES: Aim of this study is to correlate distribution pattern of lower limb atherosclerosis with cardiovascular risk factor profile of patients with peripheral arterial occlusive disease (PAD). PATIENTS AND METHODS: Analysis is based on a consecutive series of 2659 patients (1583 men, 1076 women, 70+/-11 years) with chronic PAD of atherosclerotic origin undergoing primary endovascular treatment of lower extremity arteries. Pattern of atherosclerosis was grouped into iliac (n=1166), femoropopliteal (n=2151) and infrageniculate (n=888) disease defined according to target lesions treated. A multivariable multinomial logistic regression analysis was performed to assess relation with age, gender and classical cardiovascular risk factors (diabetes mellitus, arterial hypertension, hypercholesterolemia, cigarette smoking) using femoropopliteal disease as reference. RESULTS: Iliac disease was associated with younger age (RRR 0.95 per year of age, 95%-CI 0.94-0.96, p<0.001), male gender (RRR 1.32, 95%-CI 1.09-1.59, p=0.004) and cigarette smoking (RRR 2.02, 95%-CI 1.68-2.42, p<0.001). Infrageniculate disease was associated with higher age (RRR 1.02, 95%-CI 1.01-1.02, p<0.001), male gender (RRR 1.23, 95%-CI 1.06-1.41, p=0.005) and diabetes mellitus (RRR 1.68, 95%-CI 1.47-1.92, p<0.001). Hypercholesterolemia was less prevalent in patients with lesions below the knee (RRR 0.82, 95%-CI 0.71-0.94, p=0.006), whereas no distinct pattern was apparent related to arterial hypertension. CONCLUSION: Clinical phenotype of peripheral atherosclerosis varies with prevalence of cardiovascular risk factors suggesting differences in mechanisms involved in iliac as compared with infrageniculate lesions. Identification of molecular mechanism might have influence on future therapeutic strategies in PAD patients. 相似文献
5.
Effective intracellular delivery of oligonucleotides in order to make sense of antisense. 总被引:5,自引:0,他引:5
For more than two decades, antisense oligonucleotides (ODNs) have been used to modulate gene expression for the purpose of applications in cell biology and for development of novel sophisticated medical therapeutics. Conceptually, the antisense approach represents an elegant strategy, involving the targeting to and association of an ODN sequence with a specific mRNA via base-pairing, resulting in an impairment of functional and/or harmful protein expression in normal and diseased cells/tissue, respectively. Apart from ODN stability, its efficiency very much depends on intracellular delivery and release/access to the target side, issues that are still relatively poorly understood. Since free ODNs enter cells relatively poorly, appropriate carriers, often composed of polymers and cationic lipids, have been developed. Such carriers allow efficient delivery of ODNs into cells in vitro, and the mechanisms of delivery, both in terms of biophysical requirements for the carrier and cell biological features of uptake, are gradually becoming apparent. To become effective, ODNs require delivery into the nucleus, which necessitates release of internalized ODNs from endosomal compartments, an event that seems to depend on the nature of the delivery vehicle and distinct structural shape changes. Interestingly, evidence is accumulating which suggests that by modulating the surface properties of the carrier, the kinetics of such changes can be controlled, thus providing possibilities for programmable release of the carrier contents. Here, consideration will also be given to antisense design and chemistry, and the challenge of extra- and intracellular barriers to be overcome in the delivery process. 相似文献
6.
Selma C. Tromp Geert Jan Tangelder Dick W. Slaaf Robert S. Reneman S. van Velzen Wim Engels E. van Breda M. G. A. oude Egbrink 《Pflügers Archiv : European journal of physiology》1998,436(2):255-261
The objective of the present study was to determine the role of mast cells and histamine in leukocyte-endothelium interactions
in mesenteric venules of four rat strains: Brown Norway, Lewis, Sprague-Dawley and Wistar. Intravital microscopy showed that
the mast cell stabilizer cromoglycate (5 mg/kg i.v. just before exteriorization of the mesentery) did not affect the baseline
level and velocity of leukocyte rolling in any of the four strains. This finding is in agreement with the observation that
cromoglycate pretreatment only slightly influenced mast cell degranulation in all strains except the Brown Norway. After mast
cell stabilization, only in Sprague-Dawley did topical administration of histamine (10–4 M) result in a significant increase in the level of leukocyte rolling and a decrease in the rolling velocity compared with
the time control. Histamine induced leukocyte adhesion only in the Brown Norway strain. In conclusion, the hypothesis presented
in other studies, that degranulation of mast cells, and more specifically the release of histamine, is of major importance
for the induction of leukocyte-endothelium interactions in rat mesenteric venules is not generally applicable; the present
study shows a clear strain dependency.
Received: 18 July 1997 / Received after revision: 17 November 1997 / Accepted: 13 March 1998 相似文献
7.
Percutaneous transhepatic placement of biliary endoprostheses: results in 100 consecutive patients. 总被引:4,自引:0,他引:4
B W Dick R L Gordon J M LaBerge M M Doherty E J Ring 《Journal of vascular and interventional radiology : JVIR》1990,1(1):97-100
One hundred patients with malignant biliary obstruction underwent palliative therapy by means of percutaneous transhepatic placement of 114 biliary endoprostheses. All patients were then followed up for at least 18 months or until death. Retrospective evaluation of the 95 patients who died showed an average survival time of 5.0 months. The five remaining patients have survived an average of 29.8 months. During the 1st week after stent insertion, a second manipulation was performed to improve stent function in nine patients. Overall, 14 (12.3%) of the stents became obstructed and six (5.2%) migrated; 86 patients required no further therapy for biliary obstruction or stent malfunction. The 30-day mortality rate was 12%; none of the deaths were directly attributable to a complication of the stent placement procedure. 相似文献
8.
J P Dick 《Journal of the Royal Society of Medicine》1992,85(9):517-518
9.
E. Andrs G. Kaltenbach E. Noel M. Noblet‐Dick A.‐E. Perrin T. Vogel J.‐L. Schlienger M. Berthel J. F. Blickl 《International journal of laboratory hematology》2003,25(3):161-166
Background: It has been suggested that oral cobalamin (vitamin B12) therapy may be an effective therapy for treating cobalamin deficiencies related to food‐cobalamin malabsorption. However, the duration of this treatment was not determined. Patients and method: In an open‐label, nonplacebo study, we studied 30 patients with established cobalamin deficiency related to food‐cobalamin malabsorption, who received between 250 and 1000 μg of oral crystalline cyanocobalamin per day for at least 1 month. Endpoints: Blood counts, serum cobalamin and homocysteine levels were determined at baseline and during the first month of treatment. Results: During the first month of treatment, 87% of the patients normalized their serum cobalamin levels; 100% increased their serum cobalamin levels (mean increase, +167 pg/dl; P < 0.001 compared with baseline); 100% had evidence of medullary regeneration; 100% corrected their initial macrocytosis; and 54% corrected their anemia. All patients had increased hemoglobin levels (mean increase, +0.6 g/dl) and reticulocyte counts (mean increase, +35 × 106/l) and decreased erythrocyte cell volume (mean decrease, 3 fl; all P < 0.05). Conclusion: Our findings suggest that crystalline cyanocobalamin, 250–1000 μg /day, given orally for 1 month, may be an effective treatment for cobalamin deficiencies not related to pernicious anemia. 相似文献
10.
Prof. Dr. W. Lorenz B. Stinner M. Rothmund D. Duda W. Dick H. Menke Th. Junginger 《European Surgery》1992,24(3):128-134
Zusammenfassung Probleml?sungsstrategien zu perioperativen Prophylaxema?nahmen umfassen mehr Studienarten als Tierexperimente und kontrollierte
klinische Studien. Dabei verhelfen Methoden der kognitiven Psychologie und künstlichen Intelligenz zu neuen Verfahren, um
kontroverse Standpunkte in der klinischen Versorgung zu formalisieren. Der Weg vom Tierexperiment zur klinischen Indikation,
mag mühevoll und beschwerlich sein, aber die Strategie hat sich bei der perioperativen Antihistaminikaprophylaxe als eine
neue Form der Prophylaxe schon bew?hrt. Gerade wurde im Refresher Course der ASA, der amerikanischen Gesellschaft für An?sthesie
und Intensivmedizin, diese Prophylaxe für alle US-An?sthesisten empfohlen.
Mit Unterstützung durch die Deutsche Forschungsgemeinschaft (Lo 199/16-2). 相似文献