全文获取类型
收费全文 | 2852篇 |
免费 | 155篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 146篇 |
妇产科学 | 131篇 |
基础医学 | 289篇 |
口腔科学 | 160篇 |
临床医学 | 181篇 |
内科学 | 547篇 |
皮肤病学 | 62篇 |
神经病学 | 171篇 |
特种医学 | 108篇 |
外科学 | 592篇 |
综合类 | 42篇 |
预防医学 | 75篇 |
眼科学 | 178篇 |
药学 | 122篇 |
中国医学 | 6篇 |
肿瘤学 | 175篇 |
出版年
2024年 | 1篇 |
2023年 | 23篇 |
2022年 | 34篇 |
2021年 | 70篇 |
2020年 | 44篇 |
2019年 | 47篇 |
2018年 | 78篇 |
2017年 | 58篇 |
2016年 | 96篇 |
2015年 | 118篇 |
2014年 | 147篇 |
2013年 | 193篇 |
2012年 | 247篇 |
2011年 | 226篇 |
2010年 | 119篇 |
2009年 | 115篇 |
2008年 | 212篇 |
2007年 | 196篇 |
2006年 | 190篇 |
2005年 | 178篇 |
2004年 | 177篇 |
2003年 | 128篇 |
2002年 | 113篇 |
2001年 | 59篇 |
2000年 | 33篇 |
1999年 | 34篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1975年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有3026条查询结果,搜索用时 0 毫秒
31.
Acarturk E Koc M Bozkurt A Unal I 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2008,35(2):136-143
Our aim was to investigate, in patients with heart failure, the relationship between left atrial size and exercise capacity and cardiovascular events. Seventy-five patients (67 men and 8 women; mean age, 53.4 +/- 8.8 yr) with left ventricular ejection fractions of < or =0.45 (New York Heart Association functional classes I-III) were matched by age and sex with 20 healthy control subjects. Echocardiographic examinations were performed, as was exercise testing by the modified Bruce protocol. Patients were monitored for a period of 330 to 480 days for cardiac death or for heart failure that required hospitalization. The indexed left atrial diastolic size (beta level = -0.534, P <0.001) and left ventricular late diastolic filling velocity (beta level = 0.247, P <0.017) were the most important values in predicting low exercise capacity. The only independent predictor of low exercise capacity (<5 METS) was the indexed left atrial diastolic size (odds ratio, 1.428; 95% confidence interval, 1.09-1.702; P <0.001). Every 1 mm/m2 increase in indexed left atrial diastolic dimension caused a 42.8% increase in the risk of severe heart failure (exercise capacity, <5 METS). Independent predictors for cardiovascular events were indexed as left atrial systolic size (odds ratio, 1.383; 95% confidence interval, 1.145-1.671; P <0.001) and left ventricular early diastolic/late diastolic filling velocity (odds ratio, 1.096; 95% confidence interval, 1.010-1.189; P <0.027). Indexed left atrial diastolic and left atrial systolic size predict exercise capacity and cardiovascular events, respectively, in New York Heart Association functional class I through III heart failure patients. 相似文献
32.
Tayfun Bozkurt MD Prof. Dr. med. Guido Adler MD Irmtraut Koop MD Herbert Koop MD Wolfgang Türmer MD Rudolf Arnold MD 《Digestive diseases and sciences》1988,33(3):276-281
After stimulation with a Lundh test meal, plasma concentrations of cholecystokinin (CCK) and pancreatic polypeptide (PP) and output of pancreatic enzymes were measured in 33 patients with exocrine pancreatic insufficiency and 26 healthy subjects. Patients with impairment of pancreatic function were subdivided into those with moderate and severe insufficiency. Plasma CCK and PP were measured by radioimmunoassay. Fasting plasma CCK in patients with pancreatic insufficiency (5.8±1.1 pmol/liter) did not differ significantly from controls (4.2±0.6 pmol/liter). After endogenous stimulation with a Lundh meal, plasma CCK increased in both groups without significant differences over 2 hr. Basal and stimulated plasma levels of pancreatic polypeptide (PP) were markedly decreased only in patients with severe pancreatic insufficiency. Our results demonstrate that basal and meal-stimulated CCK levels in patients with pancreatic insufficiency do not differ from controls. Furthermore the extent of functional impairment of the exocrine pancreas did not influence basal and postprandial CCK release. 相似文献
33.
We have further characterized the biological activities, mechanism of action, and target cell populations of recombinant human and murine thrombopoietin (rhTPO and rmTPO) in in vitro human and murine model systems. Alone, hTPO or mTPO stimulated the maturation of immature murine megakaryoblasts as measured in a single cell assay. The combination of hTPO or mTPO and interleukin-6 (IL-6) resulted in a further increase in megakaryocyte differentiation in this system. Murine TPO stimulated mouse megakaryocyte progenitor development. Human megakaryocyte progenitor development was potentiated by hTPO alone and further augmented in the presence of the early-acting cytokines (IL-3) or kit ligand/stem cell factor (KL/SCF). To further define the mechanism of action of TPO, neutralization studies were performed with antisera to IL-3, granulocyte-macrophage colony-stimulating factor (GM- CSF), IL-1 beta, and IL-11. No diminution in TPO activity was observed in the presence of these antisera. Moreover, because adhesive interactions are known to modulate hematopoiesis, we studied whether hTPO might alter such interactions between human bone marrow (BM) megakaryocytes and human BM stromal fibroblasts. No changes were observed in either megakaryocyte expression of the surface molecules lymphocyte function-associated antigen-1, very late activation antigen- 4, or intercellular adhesion molecule-1 or the adhesion of megakaryocytes to stromal fibroblasts after treatment with the growth factor. Furthermore, no induction of secretion of the cytokines IL-1 alpha, IL-1 beta, GM-CSF, IL-6, granulocyte-CSF, tumor necrosis factor- alpha, transforming growth factor-beta 1, or transforming growth factor- beta 2 by primary human BM megakaryocytes was noted after treatment of the cells with hTPO. To address whether TPO affects very primitive hematopoietic progenitors, we studied the residual cells from the BMs of mice treated with high doses of 5-fluorouracil. Although no effect of mTPO alone was noted on the viability or replication of such primitive murine progenitor populations, the triple combination of IL-3 + KL/SCF + TPO stimulated growth of megakaryocyte progenitors. These results indicate that TPO is a highly lineage-specific growth factor whose primary biological effects are likely to be direct modulation of the growth and maturation of committed megakaryocyte precursors and immature megakaryoblasts. 相似文献
34.
Gokhan Soker Bozkurt Gulek Eda Soker Omer Kaya Ibrahim Inan Muhammet Arslan Kaan Esen Derya Memis Cengiz Yilmaz 《Journal of Medical Ultrasonics》2018,45(2):287-294
Purpose
In this study, we aimed to establish a quantitative threshold value in the diagnosis of subacromial impingement syndrome by measuring the thickness of the subacromial bursa during abduction and adduction.Materials and methods
Forty-five patients with subacromial impingement syndrome and 54 healthy individuals underwent dynamic shoulder ultrasonography. The subacromial bursa, between the supraspinatus tendon margin and peribursal adipose tissue, was measured between the acromion and humeral head at its widest part. The subacromial impingement ratio was calculated by dividing the subacromial bursa thickness during abduction to the subacromial bursa thickness during adduction. Shapiro–Wilk test was used in the assessment of normal distribution of parameters.Results
The mean subacromial bursa thickness in the abduction position was 1.8 ± 1.1 mm in the study group and 0.9 ± 0.3 mm in the control group. The mean subacromial bursa thickness in the adduction position was 0.9 ± 0.5 mm in the study group and 0.8 ± 0.3 mm in the control group. The subacromial impingement ratio showed a statistically significant difference between groups (p < 0.0001), and the ratio being 2.0 ± 0.5 in the study group and 1.2 ± 0.1 in the control group. For measurements performed in the abduction position, the best cut-off value was calculated as 1.3 mm, and sensitivity and specificity were 70.6 and 85.2%, respectively. The best cut-off value was 1.4 for the subacromial impingement ratio, and sensitivity and specificity were 88.2 and 96.3%, respectively.Conclusion
Subacromial impingement ratio is a very practical and reliable method in subacromial impingement syndrome diagnosis.35.
目的:探讨放射状角膜切开术在轻中度圆锥角膜治疗中光学和视力康复的效果。
方法:回顾性分析应用放射状角膜切开术治疗圆锥角膜的病例22例31眼并进行了至少12 mo的随访。测量并分析术前术后裸眼视力,最佳矫正视力,自动屈光计值,角膜曲率,角膜不规则指数以及并发症。
结果:在最后一次随访中,平均裸眼视力( logMAR)由0.86±0.34显著提升至0.30±0.29(P<0.0001),平均最佳矫正视力由0.47±0.21提升至0.17±0.23(P<0.0001)。平均角膜曲率由48.69±3.68 D 降低至44.33±3.09 D ( P<0.0001)。自动屈光计测得平均等效球镜值由-5.61±2.85D显著提升至-2.29±1.95D(P<0.0001)。在整个随访过程中,中央角膜厚度和3mm,5mm区域的角膜不规则指数均无变化。术中和术后没有观察到严重并发症。
结论:在本组病例中,放射状角膜切开术是轻中度圆锥角膜视觉康复的有效治疗方法。 相似文献
方法:回顾性分析应用放射状角膜切开术治疗圆锥角膜的病例22例31眼并进行了至少12 mo的随访。测量并分析术前术后裸眼视力,最佳矫正视力,自动屈光计值,角膜曲率,角膜不规则指数以及并发症。
结果:在最后一次随访中,平均裸眼视力( logMAR)由0.86±0.34显著提升至0.30±0.29(P<0.0001),平均最佳矫正视力由0.47±0.21提升至0.17±0.23(P<0.0001)。平均角膜曲率由48.69±3.68 D 降低至44.33±3.09 D ( P<0.0001)。自动屈光计测得平均等效球镜值由-5.61±2.85D显著提升至-2.29±1.95D(P<0.0001)。在整个随访过程中,中央角膜厚度和3mm,5mm区域的角膜不规则指数均无变化。术中和术后没有观察到严重并发症。
结论:在本组病例中,放射状角膜切开术是轻中度圆锥角膜视觉康复的有效治疗方法。 相似文献
36.
AIM:To quantify corneal ultrastructure using laser scanning in vivo confocal microscopy (IVCM) in patients with keratoconus and control subjects.METHODS: Unscarred corneas of 78 keratoconic subjects without a history of contact lens use and 36 age-matched control subjects were evaluated with slit-lamp examination (SLE), corneal topography and laser scanning IVCM. One eye was randomly chosen for analysis. Anterior and posterior stromal keratocyte, endothelial cell and basal epithelial cell densities and sub-basal nerve structure were evaluated.RESULTS: IVCM qualitatively demonstrated enlarged basal epithelial cells, structural changes in sub-basal and stromal nerve fibers, abnormal stromal keratocytes and keratocyte nuclei, and pleomorphism and enlargement of endothelial cells. Compared with control subjects, significant reductions in basal epithelial cell density (5817±306 cells/mm2 vs 4802±508 cells/mm2, P<0.001), anterior stromal keratocyte density (800±111 cells/mm2 vs 555±115 cells/mm2, P<0.001), posterior stromal keratocyte density (333±34 cells/mm2 vs 270±47 cells/mm2, P<0.001), endothelial cell density (2875±223 cells/mm2 vs 2686±265 cells/mm2, P<0.001), sub-basal nerve fiber density (31.2±8.4 nerves/mm2 vs 18.1±9.2 nerves/mm2, P<0.001), sub-basal nerve fiber length (21.4±3.4 mm/mm2 vs 16.1±5.1 mm/mm2, P<0.001), and sub-basal nerve branch density (median 50.0 (first quartile 31.2 - third quartile 68.7) nerve branches/mm2 vs median 25.0 (first quartile 6.2 - third quartile 45.3) nerve branches/mm2, P<0.001) were observed in patients with keratoconus.CONCLUSION: Significant microstructural abnormalities were identified in all corneal layers in the eyes of subjects with keratoconus using IVCM. This non-invasive in vivo technique provides an important means to define and follow progress of microstructural changes in patients with keratoconus. 相似文献
37.
Demir Arzu Meltem Aydin Fatma Acar Banu Kurt Tuba Poyraz Aylar Kiremitci Saba Gülleroglu Basak Azili Müjdem Nur Bayrakci Umut Selda 《Clinical rheumatology》2021,40(9):3817-3825
Clinical Rheumatology - Autoimmune pancreatitis (AIP) type 1 is an IgG4-related disease (IgG4-RD), characterized by inflammatory pseudotumors and histologically by dense lymphoplasmacytic... 相似文献
38.
Erdal Simay Nalbantoğlu Banu Gür Mert Berke Yıldırım Murathan Kılıçarslan Alperen Kaymaz-Tahra Sema Alibaz-Öner Fatma Yay Meral Mumcu Gonca Direskeneli Haner 《Clinical rheumatology》2021,40(10):4109-4116
Clinical Rheumatology - The aim of this study was to evaluate the relationships among the disease activity, illness perception, daily life performance, anxiety and depression status as potential... 相似文献
39.
George Andrea Nicola Hsia Tain-Yen Schievano Silvia Bozkurt Selim 《Heart failure reviews》2022,27(3):903-913
Heart Failure Reviews - Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients’ symptoms, age, and severity... 相似文献
40.
Sebnem Egriboyun Gamze Ugurluer Funda Vesile Corapcioglu Levent Celik Gorkem Gungor Banu Atalar Enis Ozyar 《Journal of Medical Imaging and Radiation Sciences》2021,52(2):305-311
Extracranial malignant rhabdoid tumors are rare and aggressive tumors that typically occur in the pediatric age group and have a poor prognosis. Herein, we report a case of a one year and five months old male infant who was referred with the diagnosis of malignant rhabdoid tumor of the liver. Magnetic resonance guided stereotactic body radiotherapy was administered with concomitant chemotherapy. Treatment was well tolerated with no severe acute side effects. A 40.8% volumetric reduction of the tumor was observed at the last fraction of MR guided radiotherapy. 相似文献