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   1454篇
  免费   73篇
  国内免费   8篇
耳鼻咽喉   17篇
儿科学   98篇
妇产科学   28篇
基础医学   114篇
口腔科学   52篇
临床医学   146篇
内科学   362篇
皮肤病学   52篇
神经病学   44篇
特种医学   169篇
外科学   295篇
综合类   23篇
预防医学   45篇
眼科学   5篇
药学   53篇
肿瘤学   32篇
  2023年   6篇
  2022年   11篇
  2021年   22篇
  2020年   7篇
  2019年   18篇
  2018年   23篇
  2017年   22篇
  2016年   39篇
  2015年   45篇
  2014年   41篇
  2013年   64篇
  2012年   52篇
  2011年   60篇
  2010年   63篇
  2009年   81篇
  2008年   85篇
  2007年   84篇
  2006年   94篇
  2005年   89篇
  2004年   76篇
  2003年   57篇
  2002年   40篇
  2001年   24篇
  2000年   23篇
  1999年   32篇
  1998年   38篇
  1997年   32篇
  1996年   35篇
  1995年   28篇
  1994年   26篇
  1993年   22篇
  1992年   12篇
  1991年   11篇
  1990年   9篇
  1989年   18篇
  1988年   12篇
  1987年   14篇
  1986年   10篇
  1985年   12篇
  1984年   9篇
  1983年   6篇
  1982年   10篇
  1981年   10篇
  1980年   3篇
  1979年   8篇
  1978年   12篇
  1977年   15篇
  1976年   9篇
  1975年   10篇
  1974年   3篇
排序方式: 共有1535条查询结果,搜索用时 15 毫秒
31.
Anal cancer is one of the most common non‐AIDS‐defining malignancies in the era of combination antiretroviral therapy. Its precursor lesion, anal intraepithelial neoplasia (AIN), is highly prevalent in HIV‐infected populations. More than 90% of anal squamous cell cancers are attributable to human papillomavirus (HPV). While the biology of HPV‐related intraepithelial neoplasia is consistent across lower anogenital sites, the natural history of AIN is not well established and cannot be assumed to be identical to that of cervical intraepithelial neoplasia. Screening strategies to prevent anal cancer should be developed based on robust natural history data in HIV‐infected and uninfected populations. Likewise, treatments need to be tested in randomized clinical trials, and reserved for those at significant risk of progression to cancer. This review covers the epidemiology, pathogenesis and immunology of HPV infection, AIN and anal cancer, and summarizes the current diagnosis, screening and treatment strategies in HIV‐infected adults.  相似文献   
32.
Conclusion: IBCT technique should be preferred owing to its high graft survival rate and ABG gain. While no significant difference was found in middle ear pressures between ears that underwent IBCT and normal ears, compliance values were found to be decreased in patients undergoing IBCT. However, the lack of correlation between ABG gain and compliance values indicated that compliance increase had no effect on post-operative ABG results. Objective: The aim of the present study was to compare tympanometric and audiological parameters in patients undergoing inlay butterfly cartilage tympanoplasty (IBCT) with their normal ears and to determine their difference with normal ear tympanometric parameters. Methods: Overall, 25 patients that underwent an operation between August 2010–May 2014 were included in the present study. In 13 of these patients, the ear that did not undergo operation was normal. 0.5, 1, 2, 4?kHz pure sound average values, tympanometric measurements and compliance values of normal and operated ears were compared. Results: The graft survival rate in patients was found to be 92%. Mean pre-operative air–bone gap (ABG) was 16.4?±?5.4 in patients, while mean post-operative ABG was 10.9?±?5.8, with a statistically significant difference (p?=?0.001) While there was no significant difference between operated and normal ears of patients in terms of middle ear pressure (0.441), compliance values were significantly higher in normal ears than those in operated ears (0.032). When post-operative ABG gain was compared with compliance values, no significant correlation was found between ABG gain and compliance measurements (r?=??0.025 and p?=?0.936).  相似文献   
33.
Studies of visual function in behaving subjects require that stimuli be positioned reliably on the retina in the presence of eye movements. Fixational eye movements scatter stimuli about the retina, inflating estimates of receptive field dimensions, reducing estimates of peak responses, and blurring maps of receptive field subregions. Scleral search coils are frequently used to measure eye position, but their utility for correcting the effects of fixational eye movements on receptive field maps has been questioned. Using eye coils sutured to the sclera and preamplifiers configured to minimize cable artifacts, we reexamined this issue in two rhesus monkeys. During repeated fixation trials, the eye position signal was used to adjust the stimulus position, compensating for eye movements and correcting the stimulus position to place it at the desired location on the retina. Estimates of response magnitudes and receptive field characteristics in V1 and in LGN were obtained in both compensated and uncompensated conditions. Receptive fields were narrower, with steeper borders, and response amplitudes were higher when eye movement compensation was used. In sum, compensating for eye movements facilitated more precise definition of the receptive field. We also monitored horizontal vergence over long sequences of fixation trials and found the variability to be low, as expected for this precise behavior. Our results imply that eye coil signals can be highly accurate and useful for optimizing visual physiology when rigorous precautions are observed.  相似文献   
34.
International Urology and Nephrology - In this study, we aimed to investigate the effect of paricalcitol and calcitriol usage on vitamin D receptor (VDR) contents of CD8+?,...  相似文献   
35.
Change in amputation rate in a Turkish diabetic foot population   总被引:2,自引:0,他引:2  
Diabetic foot, an important cause of morbidity and mortality, is an important economic problem in all countries. We examined the duration of diabetes, ratio of hospitalization, and the amputation rates of our diabetic foot patients between 1996 and 2002 and compared the results with those obtained between 1985 and 1995. Medical reports of 117 patients with diabetic foot referred to Gazi University Medical Faculty between 1996 and 2002 were retrospectively analyzed. The mean age was 61.09+/-10.87 years and mean duration of diabetes was 16.14+/-9.44 years. Sixty-one patients were hospitalized and 56 patients were followed in our outpatient clinic. The mean duration of hospitalization was 45.00+/-18.74 (20-74) days in amputees and 28.95+/-11.61 (10-47) days in the nonamputees (P=.023). The mean age and duration of diabetes were significantly higher in amputees in the present group than that in the previous group. The amputation rate was significantly lower in the group studied between 1996 and 2002 compared to the group followed between 1985 and 1995 (9.4% vs. 21%, respectively, P<.001). Appropriate diabetes education and systematic follow-up in an outpatient clinic may delay preventable diabetic foot lesions and reduce the amputation rate.  相似文献   
36.
Varicose vein abnormalities involving the lesser saphenous vein of a 7-year-old boy are presented. The histopathology of the vein wall revealed a vacuolar degeneration without mucoid deposits of the muscle cells, which has not been described previously in the literature in congenital varices.  相似文献   
37.
Objective: Tubulointerstitial fibrosis is one of the strongest independent predictive factors in determining the prognosis in IgA nephritis. Recently, software-based quantitative measurement of interstitial fibrosis with Sirius Red staining has entered the practice. The objective of this study was to investigate the prognostic value of measurement of interstitial nephritis with this method in IgA nephritis. Method: Forty-three patients diagnosed with IgA nephritis with renal biopsy between the years 2005 and 2009 were included in this retrospective observational study. The diagnostic biopsies of 37 patients were examined. Basal data included age, gender, creatinine level, glomerular filtration rate (GFR), presence of proteinuria, hypertension, glomerulosclerosis, mesangial proliferation, and interstitial fibrosis and fibrosis index calculated by the measurement of computed images of Sirius Red positive areas. Final visit included evaluation of development of end-stage renal disease (ESRD), and GFR (whether?=?60?mL/min or <60?mL/min). Results: Numbers of patients with hypertension (75% vs. 34.5%; p?=?0.050), ESRD development (62.5% vs. 20.7%, p?=?0.035), GFR?<60?mL/min (87.5% vs. 31%; p?=?0.007) were greater; and basal GFR (34.25?±?25.29 vs. 64.14?±?35.34; p?=?0.048) was lower in high-intensity interstitial fibrosis group (>1000?μm2) compared to low-intensity interstitial fibrosis group (≤1000?μm2). Conclusion: Quantitative analysis of computed imaging of areas of Sirius Red positive tubulointerstitial fibrosis might serve as an effective novel method to determine the prognosis in IgA nephritis.  相似文献   
38.
39.
The efficacy and safety of ustekinumab have been demonstrated in randomized clinical trials; however, there are few real‐life data evaluating ustekinumab. This observational, retrospective follow‐up study included 33 patients with moderate to severe psoriasis vulgaris. Patients were > 18 years old and received at least 16 weeks of ustekinumab. The efficacy of treatment was evaluated as PASI50, PASI75, and PASI90 response rates at 16, 28, 52, 76, and 100 weeks. Side effects associated with ustekinumab were recorded. Of 33 patients, 24 (72.7%) had received 45 mg ustekinumab and 9 (27.3%) 90 mg ustekinumab. At the 16th week of the treatment, 97% of the patients had PASI50, 57.6% had PASI75, and 33.3% had PASI90 response rates. At 16, 28, 52, 76, and 100 weeks, PASI50, 75, and 90 responses were generally higher in naive to biologics and in the 45 mg group than in nonnaive to biologics and in the 90 mg group but the differences were not statistically significant. In conclusion, ustekinumab is an effective and safe treatment option for patients with moderate to severe psoriasis vulgaris. It seems to be more effective in naive to biologics and patients with normal weight.  相似文献   
40.
Arterial elasticity measurement in renal transplant recipients   总被引:1,自引:0,他引:1  
Arterial distensibility is reduced in chronic kidney disease (CKD) and after kidney transplantation. Pulse counter analysis provides an assessment of compliance or elasticity of the large conduit arteries (C1) and small arteries (C2). Decreased compliance has been shown to be predictive of primary coronary events in CKD patients. The aim of the present study was to compare elasticity measurements in hemodialysis (HD) patients, renal transplant recipients (RTR), and healthy subjects whose coronary angiographies were without lesion. Twenty-three RTRs, 18 HD patients, and 20 healthy subjects were included in the study. Pulse wave analysis was used to determine large and small vessel compliances. The C1 and C2 levels were significantly lower in HD patients compared with recipients and healthy subjects. Recipients showed lower C2 level compared with healthy subjects. There was no difference in C1 and C2 measurements between recipients receiving tacrolimus versus cyclosporine. Transplantation improves large and to some extend small artery elasticities in CKD patients.  相似文献   
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