首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4838篇
  免费   197篇
  国内免费   45篇
耳鼻咽喉   124篇
儿科学   304篇
妇产科学   267篇
基础医学   379篇
口腔科学   173篇
临床医学   401篇
内科学   876篇
皮肤病学   89篇
神经病学   342篇
特种医学   180篇
外科学   1201篇
综合类   76篇
一般理论   2篇
预防医学   105篇
眼科学   178篇
药学   161篇
中国医学   11篇
肿瘤学   211篇
  2024年   5篇
  2023年   43篇
  2022年   68篇
  2021年   112篇
  2020年   75篇
  2019年   91篇
  2018年   150篇
  2017年   99篇
  2016年   145篇
  2015年   170篇
  2014年   221篇
  2013年   249篇
  2012年   334篇
  2011年   323篇
  2010年   188篇
  2009年   162篇
  2008年   320篇
  2007年   401篇
  2006年   341篇
  2005年   365篇
  2004年   324篇
  2003年   242篇
  2002年   229篇
  2001年   99篇
  2000年   69篇
  1999年   59篇
  1998年   37篇
  1997年   29篇
  1996年   25篇
  1995年   16篇
  1994年   18篇
  1993年   8篇
  1992年   19篇
  1991年   10篇
  1990年   4篇
  1989年   3篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   4篇
  1979年   2篇
  1978年   2篇
  1977年   1篇
  1976年   3篇
  1975年   1篇
  1974年   1篇
  1966年   1篇
  1963年   2篇
排序方式: 共有5080条查询结果,搜索用时 15 毫秒
71.

Purpose  

Graves’ disease is the most frequent cause of hyperthyroidism. Although treatment with antithyroid drugs or radioactive iodine is effective, surgery remains the preferred treatment for many patients. We analyzed the results of 55 prospectively followed patients who underwent total thyroidectomy for Graves’ disease.  相似文献   
72.
Study Type – Prognosis (retrospective cohort)
Level of Evidence 2b

OBJECTIVE

To externally validate the prognostic value of lymphovascular invasion (LVI) in a large international cohort of patients treated with radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB).

PATIENTS AND METHODS

We collected data from 4257 patients treated with RC and pelvic lymphadenectomy for UCB, without neoadjuvant chemotherapy, at 12 centres. LVI was defined as presence of nests of tumour cells within an endothelium‐lined space.

RESULTS

LVI was detected in 1407 patients (33.1%); the proportion of LVI increased with advancing stage, higher grade, soft‐tissue surgical margin involvement, and lymph node metastasis (P < 0.001 for all). In standard multivariate models, LVI was associated with both disease recurrence (hazard ratio 1.43, P < 0.001) and cancer‐specific mortality (1.45, P < 0.001). In the entire cohort, adding LVI to a base model that included standard features improved only minimally its predictive accuracy for both recurrence and cancer‐specific mortality (by 1.1% and 1.2%, respectively). In 3122 patients with negative lymph nodes, LVI remained independently associated with and improved the predictive accuracy of the standard predictors for recurrence (hazard ratio 1.68, P < 0.001; +2.3%) and cancer‐specific mortality (1.70, P < 0.001; +2.4%). By contrast, in 1071 node‐positive patients, LVI only marginally improved the prediction of cancer‐specific recurrence (hazard ratio 1.20, P < 0.001; +0.2%) and survival (1.23, P < 0.001; +0.5%).

CONCLUSIONS

LVI is strongly associated with clinical outcome in node‐negative patients treated with RC. The assessment of LVI might help to identify patients who could benefit from adjuvant therapy after RC. After confirmation in different populations, LVI should be included in the staging of UCB.  相似文献   
73.
Gorgulu N, Yelken B, Caliskan Y, Elitok A, Cimen AO, Yazici H, Oflaz H, Golcuk E, Ekmekci A, Turkmen A, Yildiz A, Sever MS. Endothelial dysfunction in hemodialysis patients with failed renal transplants.
Clin Transplant 2009 DOI: 10.1111/j.1399‐0012.2009.01160.x
© 2009 John Wiley & Sons A/S. Abstract: Background: Endothelial dysfunction (ED) is a common precursor and denominator of cardiovascular events including development of atherosclerosis. In this cross‐sectional study, we aimed to investigate ED, measured by coronary flow reserve (CFR) in hemodialysis (nHD) patients who were never transplanted and patients with failed renal transplants restarting hemodialysis (fTx‐HD). Methods: Forty nHD (24 males, mean age 39 ± 9 yr) and 43 fTx‐HD patients (27 males, mean age 36 ± 9 yr) were included in the study. Clinical and biochemical parameters, including high‐sensitive C‐reactive protein (hs‐CRP) levels were determined. Also, CFR measurements were used to evaluate ED. Results: There were no significant differences regarding age, gender, smoking status, systolic and diastolic blood pressure levels, mean duration of HD treatment as well as Kt/V(urea) values between the two groups. Time spent on dialysis in the nHD group and dialysis duration following failure of renal allograft in the fTx‐HD group were similar. Serum creatinine, hemoglobin, hematocrit, calcium and phosphorus levels were similar between the two groups as well. When compared to nHD group, serum total cholesterol (139 ± 3 vs. 154 ± 3 mg/dL, p = 0.045), serum albumin (3.8 ± 0.3 g/dL vs. 4.1 ± 0.2 g/dL, p < 0.0001) and CFR (1.60 ± 0.2 vs. 1.75 ± 0.3, p = 0.028) levels were significantly lower, while serum hs‐CRP levels (11 ± 15 mg/L vs. 3 ± 4 mg/L, p = 0.001) were significantly higher in the fTx‐HD group. Serum hs‐CRP negatively correlated (r = ?0254, p = 0.021), while serum albumin positively correlated (r = 0402, p = 0.001) with CFR values. Conclusion: ED is more prominent in fTx‐HD than the nHD patients. Inflammation, caused by failed renal allograft can be responsible for this abnormality.  相似文献   
74.
Isola spinal instrumentation system for idiopathic scoliosis   总被引:8,自引:0,他引:8  
Since the definition of three-dimensional components of the scoliotic deformity, there have been important improvements in the surgical treatment of the problem. A derotation maneuver was proposed as a treatment option with CD instrumentation, but the reports of imbalance and decompensation with this system repopularized sublaminar wiring and translation as a corrective maneuver. Isola spinal instrumentation is one of the modern systems that utilizes vertebral translation instead of rod rotation. This study analyzes the results of 24 patients with idiopathic scoliosis who had been followed up for at least 2 years, and were surgically treated with titanium Isola Spinal Instrumentation in the Department of Orthopaedics and Traumatology, Ankara Social Security Hospital. Patients were grouped according to the King-Moe classification. Patients with type III, IV or V curves received only posterior instrumentation while this procedure followed anterior release and discectomy in the same session in patients with type I or II curves. A translation maneuver was utilized in the correction of scoliotic curves using the cantilever technique, either alone or supplemented by sublaminar wiring with Songer multifilament titanium cables. This study aimed to elucidate the effects of this technique in the frontal and sagittal plane curves and the trunk balance. The balance was analyzed clinically and radiologically by measurement of the lateral trunk shift (LT), shift of stable vertebra (SS), and shift of head (SH) in vertebral units (VU). The postoperative correction was significant in the frontal plane for all types of curves (p < 0.05). The postoperative correction was 80.9% +/- 9.5% in type III curves. Overall, the mean Cobb angle of the major curve value in the frontal plane was 66.9 degrees +/- 18.8 degrees, and it was corrected by 62.8% +/- 20.1%. The correction loss of Cobb angles in the frontal plane was 5.4 degrees +/- 5.5 degrees at the last follow-up visit. A normal physiologic thoracic contour (30 degrees - 50 degrees) was achieved in 83.3% of the patients and normal lumbar contour (40 degrees - 60 degrees) in 66.7% of the patients in the sagittal plane. The correction was found to be significant in all balance values (p < 0.05). The postoperative correction in LT values correlated with the correction of the Cobb angle values in the frontal plane. All patients had complete balance (SH: 0 VU and SS: 0 VU) or balanced curves (0 VU < SH, SS < 0.5 VU).Finally, the study concluded that the translation maneuver, especially when used with the cantilever technique, resulted in high correction rates in the frontal plane. Additionally, the technique was also successful in obtaining normal sagittal contours and correcting balance values.  相似文献   
75.
Ectopic thyroid tumours arising in the mediastinum without connection to the cervical thyroid gland are very rare. Follicular adenoma, papillary carcinoma and follicular carcinoma in the mediastinum has been reported, but primary ectopic thyroid B cell lymphoma has not been reported previously. We report mediastinal primary ectopic thyroid large B cell lymphoma in an 80-year-old man. Differential diagnosis from primary mediastinal large B cell lymphoma and clinicopathologic features are discussed.  相似文献   
76.
PURPOSE: To determine the concentration of hydroxyproline (Hyp) in aqueous humor and serum samples of patients with and without pseudoexfoliation (PEX). PATIENTS AND METHODS: Aqueous humor and serum Hyp levels were measured in cataract patients. Patients were divided into PEX and control groups. Samples were obtained from 27 cataract patients with PEX and 25 cataract patients without PEX. Patients had no elevated intraocular pressure or glaucoma. Hyp concentration was determined spectrophotometrically. RESULTS: Mean Hyp concentration in the PEX aqueous (0.86+/-0.27 mg/L) and serum (40.8+/-6.14 mg/L) samples was significantly higher than that measured in the control aqueous (0.56+/-0.2 mg/L) and serum (34.51+/-6.82 mg/L) samples, respectively (P<0.001, P=0.001). No significant correlation could be found between aqueous humor and serum Hyp concentrations. CONCLUSIONS: The higher levels of Hyp could be a sign of increased collagen turnover in PEX syndrome.  相似文献   
77.
PURPOSE: To evaluate the effectiveness of laser-assisted subepithelial keratectomy (LASEK) to treat residual refractive errors after laser in situ keratomileusis (LASIK). SETTINGS: Isik Eye Clinic, Ankara, Turkey. METHODS: This retrospective study included 24 eyes of 15 patients who had retreatment by LASEK for residual refractive errors after myopic LASIK. All patients had examinations that included slitlamp biomicroscopy, subjective and cycloplegic refractions, uncorrected visual acuity (UCVA), best corrected visual acuity, corneal topography, and pachymetry preoperatively and postoperatively. Postoperative examinations were performed at 1 week and 1, 3, and 6 months. RESULTS: The patient cohort comprised 9 men and 6 women. The median spherical equivalent (SE) of attempted correction for retreatment with LASEK was -1.25 diopters (D). The median follow-up after LASEK was 11.5 months (range 6 to 16 months). At the end of the follow-up, the median SE of the refractive error was -0.38 D. The median UCVA increased from 20/45 before LASEK to 20/25 at the last follow-up visit, which was statistically significant (P<.001). After LASEK, significant postoperative haze developed in 5 eyes. In all 5 eyes, the estimated ablation depth was more than 40 mum and the SE of attempted correction was -2.00 D or greater. CONCLUSIONS: Laser-assisted subepithelial keratectomy retreatment in eyes with myopic regression after LASIK resulted in a significant improvement in UCVA that was comparable to the improvement after flap lifting. An SE of attempted correction greater than -2.00 D was associated with a significant rate of haze.  相似文献   
78.
PURPOSE: To compare the effectiveness of brinzolamide 1%, brimonidine 0.2%, acetazolamide 250 mg, intracameral acetylcholine, and timolol 0.5% in preventing intraocular pressure (IOP) peaks during the early period after phacoemulsification in which sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat) was used as the ophthalmic viscosurgical device (OVD). SETTING: Department of Ophthalmology, Baskent University Medical Faculty, Ankara, Turkey. METHODS: This prospective randomized study comprised 185 eyes of 185 patients with uncomplicated cataract scheduled for phacoemulsification using Viscoat as the OVD. Patients were randomly assigned to 1 of 6 groups: postoperative application of topical brinzolamide 1%, brimonidine 0.2%, oral acetazolamide 250 mg, intracameral acetylcholine, timolol 0.5%, or no ocular hypotensive agent (control group). The IOP was measured at baseline (preoperatively) as well as 6 hours, 20 to 24 hours, and 1 week after surgery. RESULTS: The mean preoperative IOP values were not significantly different between the groups. Six hours and 20 to 24 hours postoperatively, the mean IOP was significantly lower in all groups receiving an ocular hypotensive agent than in the control group (P<.01). Six hours after surgery, the mean IOP significantly increased in all groups but was higher in the control group. At 20 to 24 hours, the mean IOP decreased significantly in all ocular hypotensive agent groups but remained significantly high in the control group. One week after surgery, there were no significant differences between the groups. CONCLUSION: Brinzolamide, brimonidine, acetazolamide, intracameral acetylcholine, and timolol had similar effects in reducing IOP increases after phacoemulsification performed using Viscoat.  相似文献   
79.
Pellagra is clinically manifested by a photosensitive dermatitis, diarrhea, and dementia. The full triad of symptoms is usually not well developed in infants and children. We report a case of a 14-year-old boy with classic symptoms of pellagra. All his symptoms responded to treatment with nicotinic acid.  相似文献   
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号