全文获取类型
收费全文 | 1820篇 |
免费 | 78篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 103篇 |
儿科学 | 60篇 |
妇产科学 | 70篇 |
基础医学 | 89篇 |
口腔科学 | 42篇 |
临床医学 | 134篇 |
内科学 | 514篇 |
皮肤病学 | 52篇 |
神经病学 | 75篇 |
特种医学 | 87篇 |
外科学 | 401篇 |
综合类 | 30篇 |
预防医学 | 36篇 |
眼科学 | 59篇 |
药学 | 32篇 |
1篇 | |
中国医学 | 2篇 |
肿瘤学 | 122篇 |
出版年
2024年 | 3篇 |
2023年 | 14篇 |
2022年 | 19篇 |
2021年 | 39篇 |
2020年 | 39篇 |
2019年 | 27篇 |
2018年 | 43篇 |
2017年 | 39篇 |
2016年 | 60篇 |
2015年 | 64篇 |
2014年 | 90篇 |
2013年 | 106篇 |
2012年 | 151篇 |
2011年 | 128篇 |
2010年 | 75篇 |
2009年 | 73篇 |
2008年 | 149篇 |
2007年 | 166篇 |
2006年 | 125篇 |
2005年 | 123篇 |
2004年 | 106篇 |
2003年 | 82篇 |
2002年 | 74篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 7篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 5篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有1909条查询结果,搜索用时 15 毫秒
21.
Erkan Yildirim Erkan Kaptanoglu Kanat Ozisik Ethem Beskonakli Ozerk Okutan Mustafa F Sargon Kamer Kilinc Unal Sakinci 《European journal of cardio-thoracic surgery》2004,25(4):523-529
OBJECTIVE: We aimed to demonstrate the time-dependent ultrastructural changes in pneumocyte type II cells following brain injury, and to propose an electron microscopic scoring model for the damage. METHODS: Forty Wistar-Albino female rats weighing 170-200 g were used. The rats were allocated into five groups. The first group was the control and the second was the craniotomy without trauma. The others were trauma groups. Weight-drop method was used for achieving head trauma. Samples were obtained from the right and left pulmonary lobes at 2-, 8-, and 24-h intervals after transcardiac perfusion. An electron microscopic scoring model was used to reveal the changes. RESULTS: There were no ultrastructural pathological findings pointing to lung injury in any rat of the control groups. There was intense intracellular oedema in type II pneumocyte and interstitial oedema in the adjacent tissue in trauma groups. Oedema in mitochondria and dilatation in both smooth endoplasmic reticulum and Golgi apparatus was more evident in the 8- and 24-h trauma groups. The chromatin dispersion was disintegrated in the nucleus in all trauma groups. Scores of all trauma groups were significantly different from the controls (P<0.05). All trauma groups were different from each other at significant levels (P<0.05 for each trauma groups). CONCLUSIONS: The data suggested that ultrastructural damage is obvious at 2 h and deteriorates with time. The electron microscopic scoring model worked well in depicting the traumatic changes, which were supported by lipid peroxidation. Further experiments are needed to determine the exact outcome after brain death model. 相似文献
22.
Giant hydronephrosis due to ureteropelvic junction obstruction in a child: CT and MR appearances 总被引:2,自引:0,他引:2
Giant hydronephrosis caused by congenital ureteropelvic junction (UPJ) obstruction is a rare urological entity in childhood. We report a case of giant hydronephrosis in a 12-year-old boy presented with abdominal distension. Radiological features of this rare entity are discussed with an overview of sonographic findings, especially including CT and MR appearances. The current literature is also reviewed. 相似文献
23.
24.
To investigate the effect of cyclosporine A (Cyc A) on the development of fibroadenomas, 30 renal transplant patients and 20 chronic renal failure patients on dialysis were breast examined with ultrasonography and/or mammography. Of the renal transplant patients, 17 were receiving Cyc A-based combination therapy for immunosuppression. All patients were female with the age range of 29.7+/-9.2 years in the transplant group and 33.95+/-9.91 in the dialysis group. Eight of the 17 patients receiving Cyc A had fibroadenomas, 5 of them having bilateral lesions. None of the other patients, those on dialysis and on non-Cyc A combination therapy had fibroadenomas. A significant difference for fibroadenoma incidence in patients receiving Cyc A combination immunosuppression was found. 相似文献
25.
Kagan Tun Berker Cemil Ahmet Gurhan Gurcay Erkan Kaptanoglu Mustafa F. Sargon Ibrahim Tekdemir Ayhan Comert Yucel Kanpolat 《Surgical neurology》2009,72(5):496-500
BackgroundPRF treatment has recently been described as minimally neurodestructive alternative to radiofrequency heat lesions. Patients with some pain syndromes in whom the pain could not be controlled by alternative techniques may be treated using PRF. In the present study, our main goal was to evaluate and compare the ultrastructure of peripheral nerve tissue that was heated by PRF, CRF with 42°C, and CRF with 70°C.MethodsForty-five male rats were divided into 5 groups. In PRF group and CRF with 42°C group, the sciatic nerve was heated at a temperature of 42°C for 120 seconds. As a positive control, some rat sciatic nerves were treated with CRF lesions at 70°C. The rats were kept alive for 21 days and then killed. Tissue was evaluated with transmission electron microscope, and grading was done to the groups.ResultsThe unmyelinated nerve fibers were ultrastructurally normal in all groups. The results of myelinated axons indicated that PRF group had better grades, and CRF with 70°C group had the worst grade. Especially, comparison of the group of PRF and CRF with 42°C revealed significant difference. In PRF group, none of the myelinated axons showed severe degeneration findings, and most of the damaged myelinated axons showed only separation in myelin configuration.ConclusionsPRF treatment may cause separation in myelinated axons. However, it seems that all changes were reversible. The present study supports the hypothesis that pulsed RF treatment does not rely on thermal injury of neurologic tissue to achieve its effect. 相似文献
26.
Dilek Durmuş Gamze Alaylı Oğuz Uzun Berna Tander Ferhan Cantürk Yüksel Bek Levent Erkan 《Joint, bone, spine : revue du rhumatisme》2009,76(2):150-155
ObjectiveThe aim of this study was to evaluate the impact of two different home-based daily exercise programs on pulmonary functions in the patients with ankylosing spondylitis (AS).MethodsFifty-one patients with AS were distributed into three groups. Group 1 (n = 19) was given a conventional exercise regimen. Group 2 (n = 19) received exercises based on the Global Posture Reeducation (GPR) method. Group 3 (n = 13) was accepted as the control group. Patients were assessed according to pain, functional capacity (The Bath Ankylosing Spondylitis Functional Index – BASFI), disease activity (The Bath Ankylosing Spondylitis Disease Activity Index – BASDAI), chest expansion, pulmonary function parameters, and 6-min walk distance (6MWD) test.ResultsAlthough there were significant improvements for BASDAI and BASFI scores in all groups, significant improvements in the VAS pain, chest expansion, pulmonary function parameters and 6MWD test were observed in the exercise groups. The improvements in pain, functional capacity, disease activity, chest expansion, pulmonary function parameters and 6MWD test were better in the exercise groups than in the control group. The GPR method resulted in greater improvements than the conventional exercise program in specific pulmonary function parameters like forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow parameters.ConclusionBoth exercises are efficient in improving pulmonary functions. Since the improvements in pulmonary function tests were greater in the patients who performed the exercise according to GPR method, motivated patients should be encouraged to perform this exercise program. 相似文献
27.
Serkan Erkan Chunhui Wu Amir A. Mehbod Brian Hsu Douglas W. Pahl Ensor E. Transfeldt 《European spine journal》2009,18(6):807-814
Single level axial lumbar interbody fusion (AxiaLIF) using a transsacral rod through a paracoccygeal approach has been developed
with promising early clinical results and biomechanical stability. Recently, the transsacral rod has been extended to perform
a two-level fusion at both L4–L5 and L5–S1 levels (AxiaLIF II). No biomechanical studies have been conducted on multilevel
fusion using the AxiaLIF technique. In this study, the biomechanics of L4–S1 motion segments instrumented with the AxiaLIF
II transsacral rod was evaluated. Six human cadaveric lumbosacral spine segments from L4 to S1 were used (age ranges 46–74 years).
Unconstrained and non-destructive pure moments in axial torsion, lateral bending, and flexion extension were applied to each
specimen following intact, standalone AxiaLIF II, and AxiaLIF II with two posterior fixation options: facet screws and pedicle
screws with rods. Range of motion was calculated from the raw data collected with an optical motion tracking system. The two-level
transsacral rod was successfully inserted in all the specimens. At L4–L5 level in axial torsion (AT) and flexion extension
(FE), none of the surgical treatments showed statistically significant difference between the procedures (all P > 0.05) although facet screws and pedicle screws had higher stability on average. In lateral bending (LB), the two posterior
fixation techniques had significantly higher construct stability (P < 0.05) than the standalone rod. No significant difference was found between facet screws and pedicle screws (P = 0.821). At L5–S1 level in AT and LB, none of the surgical treatments were found to be statistically significant (all P > 0.05). In FE, standalone two-level transsacral rod had significantly higher range of motion (ROM) compared with the posterior
fixation techniques (P < 0.05). In conclusion, the standalone rod reduced intact ROM significantly. Supplementary fixations including facet screws
and pedicle screws are required to achieve higher construct stability for successful fusion. Further clinical studies are
essential to evaluate the practical success of this technique. 相似文献
28.
Background and study aims Stent migration occurs in about 5–10% of patients undergoing biliary stenting. The aim of this study was to analyze the risk
factors for stent migration in patients with benign and malignant strictures.
Patients and methods We retrospectively analyzed records of 524 biliary plastic stent placement procedures. Details noted included the cause and
localization of stricture, characteristics and number of stents, direction of stent migration, presentation of patient with
migrated stent, and the methods used for retrieval of migrated stents.
Results Two hundred and four (38.9%) of the procedures were performed for benign biliary strictures (BBS) and 320 (61.1%) for malignant
biliary strictures (MBS). Thirty-four patients had 45 migrated biliary stents. The rate of migration was 8.58% (proximal 4.58%
and distal 4.00%). Migration frequency was higher in BBS compared with MBS (13.7% versus 5.3%, p = 0.001). In BBS, the rate of stent migration was higher in cases with one (19.3%) and two stents (20.9%) when compared with
cases with multiple stents (2.7%) (p = 0.001; p = 0.001, respectively). Migration occurred more frequently (10.9%) in cases with two stents when compared both to cases with
one stent (3.0%) and those with multiple stents (0%) in MBS (p = 0.008; p = 0.020, respectively). In BBS, short stents migrated more frequently proximally (77%) and long stents more frequently distally
(73%) (p = 0.008). In BBS, migration in cases with proximal stricture occurred more frequently distally (76.9%), while in those with
distal stricture, migration was more frequently proximal (73.3%) (p = 0.008). All of the proximally migrated stents could be successfully retrieved endoscopically.
Conclusions The risk of stent migration is higher in BBS compared with in MBS. The cases with multiple stents had significantly lower
stent migration. In BBS, long stent, proximal and postcholecystectomy strictures were associated with distal migration, while
short stent, distal and non-postcholecystectomy strictures were associated with proximal migration. 相似文献
29.
Demirkilic U Gunay C Bolcal C Doganci S Cingoz F Kuralay E Tatar H 《Journal of cardiac surgery》2005,20(2):124-128
AIM: To delineate whether coronary arteriovenous malformations have different properties than classical discrete coronary artery fistulae. METHODS: Group 1 included 17 patients with discrete coronary fistula that represents a coronary artery fistula draining into any cardiac chamber. Group 2 included six patients with coronary arteriovenous malformations representing extensive coronary artery malformation. Cardiopulmonary bypass was used in 12 of the Group 1 patients and 5 in Group 2. RESULTS: There was no operative mortality in either group. Following a hemodynamically nonsignificant residual fistulous communication, which was detected by repeat coronary angiography in Group 2; we changed our surgical technique of suture ligation on beating heart. Then we preferred pulmonary arteriotomy and sutured the orifice of coronary arteriovenous malformations from within the chamber. CONCLUSIONS: Coronary arteriovenous malformations have different morphology and also complex progression properties when compared with discrete coronary artery fistulae. Surgical repair of coronary arteriovenous malformation should be done by suturing the multiple drainage holes inside the draining chamber. Suture ligation of coronary arteriovenous malformation is difficult due to the fragile vessel. 相似文献
30.
Haci Akar Erkan Iriz Fer?at Kolbakir Atilla Sarac Olcay Sagkan 《Annals of thoracic and cardiovascular surgery》2005,11(3):201-203
We describe a case of congenitally corrected transposition of great arteries (CCTGA). Tricuspid valve replacement was performed due to valve dysfunction following bacterial endocarditis. After two weeks' antibiotic therapy haemodynamic stabilisation was obtained and the patient was operated in the third week. On cardiopulmonary bypass with 28 degrees C degree systemic hypothermia, the left atrium was approached transeptally. At exploration, the systemic atrioventricular valve was tricuspid valve and pulmonary atrioventricular valve was in shape of a mitral valve. The posterior leaflet of the tricuspid valve was ruptured and vegetations above it were observed. The valve was excised and a 29 mm St-Jude mechanical heart valve prosthesis implanted using a teflon reinforced separated suture technique. After operation the patient recovered rapidly and following six weeks' antibiotic therapy, the patient was discharged. 相似文献