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   1899篇
  免费   104篇
  国内免费   6篇
耳鼻咽喉   8篇
儿科学   52篇
妇产科学   61篇
基础医学   263篇
口腔科学   28篇
临床医学   167篇
内科学   408篇
皮肤病学   22篇
神经病学   181篇
特种医学   134篇
外科学   291篇
综合类   3篇
预防医学   112篇
眼科学   19篇
药学   125篇
中国医学   1篇
肿瘤学   134篇
  2023年   14篇
  2022年   24篇
  2021年   53篇
  2020年   20篇
  2019年   38篇
  2018年   51篇
  2017年   41篇
  2016年   31篇
  2015年   46篇
  2014年   77篇
  2013年   103篇
  2012年   117篇
  2011年   105篇
  2010年   89篇
  2009年   81篇
  2008年   97篇
  2007年   95篇
  2006年   119篇
  2005年   97篇
  2004年   89篇
  2003年   69篇
  2002年   74篇
  2001年   65篇
  2000年   52篇
  1999年   40篇
  1998年   12篇
  1997年   14篇
  1996年   8篇
  1995年   14篇
  1994年   15篇
  1993年   6篇
  1992年   25篇
  1991年   37篇
  1990年   26篇
  1989年   25篇
  1988年   10篇
  1987年   16篇
  1986年   11篇
  1985年   15篇
  1984年   8篇
  1983年   4篇
  1982年   4篇
  1980年   5篇
  1979年   14篇
  1978年   5篇
  1977年   6篇
  1974年   7篇
  1973年   8篇
  1970年   5篇
  1967年   3篇
排序方式: 共有2009条查询结果,搜索用时 0 毫秒
71.
72.
The nodular form of local hepatic tuberculosis. A review   总被引:7,自引:0,他引:7  
Local hepatic tuberculosis without active pulmonary or miliary tuberculosis is an uncommon diagnosis. Even less common is the finding of tuberculoma or tuberculous liver abscess without clinical evidence of tuberculosis elsewhere. Since 1950, 21 cases of isolated tuberculoma or tuberculous abscess of the liver have been reported in the world literature. We report an additional two cases, one tuberculoma and one with multiple tuberculous abscesses. The case reports illustrate the difficulty in reaching the correct diagnosis, unsuspected in nearly all cases and most often confused with carcinoma of the liver. The correct diagnosis was made by histology, identification of acid-fast organisms by smear, and by cultures of Mycobacterium tuberculosis, but required laparotomy in 19 of the 23 cases. A greater awareness of this rare clinical entity may prevent needless surgical intervention since the vast majority of patients respond well to antituberculous chemotherapy.  相似文献   
73.
We have studied IL-6 gene expression and production by in vitro stimulated peripheral blood mononuclear cells (PBMC) isolated from common variable immunodeficiency (CVI) patients. A strong hybridization signal for the IL-6 probe was observed in mRNA extracted from phytohaemagglutinin (PHA)- and PHA/phorbol myristate acetate (PMA)-stimulated PBMC from most of 12 CVI patients analysed. IL-6 production by PHA-stimulated PBMC from 28 CVI patients was evaluated in ELISA and found to be significantly (P < 0.0001) higher than in normal controls. IL-6 production, however, did not correlate with the lymphocyte populations examined, nor with the absolute number of monocytes. We have also showed that IL-6 was able to increase IgM secretion by several Epstein-Barr virus (EBV)-transformed cell lines derived from both normal donors and CVI patients, but it failed to modify substantially the amounts of IgM and IgG produced in vitro by PBMC derived from CVI patients and activated with pokeweed mitogen (PWM) or anti-IgM. Our data indicate that IL-6 gene expression and production is increased in CVI, but CVI cells do not respond to IL-6 with increased production of immunoglobulin.  相似文献   
74.
ObjectiveUterine serous carcinoma (USC) constitutes 10% of uterine cancers but ~ 40% of deaths. Tumor size is a known prognostic factor in other solid tumors. In endometriod cancers it is one element used to identify the need for complete staging, while its significance in USC is debated. Therefore tumor size was examined as an independent prognostic factor.MethodsClinical and pathologic variables were recorded for 236 institutional patients, and those patients in the SEER database with USC. Chi-square and Fisher exact t-tests were utilized and survival data generated via Kaplan–Meier method; multivariate analysis was performed via cox-regression.ResultsThe patients' mean age was 67.2 years (range 40–91). Survival ranged from 0 to 184 months (mean 42.8). We used a tumor size cut-off of 1 cm and noted significant associations with myometrial invasion (p < 0.0001), angiolymphatic invasion (p < 0.0001), peritoneal washings (p = 0.03), stage (p = 0.015) and positive lymph nodes (p = 0.05). Furthermore, recurrence was associated with larger tumors (p = 0.03). In multivariate analysis, extra-uterine disease was the only factor associated with both recurrence and survival. Review of the SEER database noted association of larger tumors with lymph node involvement and a significant survival advantage with tumors < 1 cm in both univariate and multivariate analysis.ConclusionsTreatment options for USC are often predicated on the surgical stage and therefore components of the staging are vitally important. The 1 cm tumor-size cut-off should be studied prospectively as a prognostic indicator of survival and recurrence in USC and considered for inclusion in USC staging.  相似文献   
75.

Background

Acute kidney injury and chronic kidney failure are serious complications after lung transplantation. Glomerular filtration rate (GFR) is the primary indicator of renal function. Several equations have been proposed to evaluate the estimated GFR (eGFR). We compared three different equations to determine which has the better correlation with the development of acute and chronic renal failure in lung recipients.

Methods

Twenty-two patients with a mean age of 54.4 ± 8.5 years underwent lung transplantation from 2010 to 2015. Thirteen (59%) had pulmonary fibrosis, 7 (32%) emphysema, 1 (4.5%) bronchiectasis, and 1 (4.5%) lymphangioleiomyomatosis. In all patients, eGFR was measured preoperatively using Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Levey's Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. In 20 patients (90%) eGFR was calculated at 1, 3, and 6 months.

Results

According to CKD-EPI and MDRD, eight patients (36.3%) had preoperative reduction in eGFR, whereas 6 patients (27.2%) had preoperative reduction according to the CG (P = .04). The mean values were higher for the CG (103.2 vs. 102 vs. 94.4). Five patients (22.7%) developed perioperative acute renal failure requesting a dialysis treatment; four of these showed a preoperative eGFR to the highest CG (P = .05). At 1 and 6 months after lung transplantation, the CG, MDRD and CKD-EPI eGFR values were, respectively, 86.6, 84.1 and 76.6 mL/min/1.73m2 and 75.8, 72.7, and 72.3 mL/min/1.73m2. CKD-EPI eGFR values are more predictable than the other equations of AKI.

Conclusions

Preoperative assessment of eGFR using the MDRD and CKD-EPI seems to correlate better than the CG to the prediction of acute renal failure, whereas for the chronic form the three equations seem equivalent.  相似文献   
76.
Achilles tendinopathy is a common cause of disability. New nerves fibers grow from the paratenon into the Achilles tendon, and they could play a central role in the development of pain. We report the results of minimally invasive Achilles tendon stripping for Achilles tendinopathy in 47 active patients. The Victorian Institute of Sports Assessment-Achilles questionnaire score improved from 53.8 preoperatively to 85.3 postoperatively (p < .001). After a mean follow-up period of 40.5 months, 41 patients had resumed sporting activities at an average of 3.5 months postoperatively. A sural nerve injury was recorded in 5 patients (10.6%), and all 5 complications occurred during the first 12 cases. As a result, the technique was slightly modified, and no sural nerve neuropathy was observed subsequently. One superficial infection (2.1%) was recorded. Minimally invasive Achilles tendon stripping seems to be an effective, technically simple, and inexpensive treatment of Achilles tendinopathy. Further randomized controlled trials involving more patients are needed to confirm these outcomes.  相似文献   
77.
ObjectiveWe assessed the prognostic value of a stage pT3a diagnosis based on perirrenal fat infiltration.Material And MethodsA series of 300 patients diagnosed of renal cell carcinoma (ccr) between 1992 and 2001 were retrospectively analyzed. focusing on pt3a tumors as defined by perirrenal fat infiltration, a group of 92 patients (91,08%) regardless lymph node involvement (nall) were included. patients with distant metastases were excluded. in patients with pt3a nall m0 tumors, tumour size was a significant parameter predicting survival. the most significant cut-off value for tumor size based on roc curve was 5,5 cm. therefore two groups were defined (up to 5,5 cm or greater than 5,5 cm) and actuarial survival were compared between both groups.ResultsNo significant differences were found comparing actuarial survival of selected pT3a and tumour size less than 5,5 cm with pT1 and pT2 tumors. After classifying selected pT3a less than 5,5 cm as pT1, multivariate analysis showed no differences regarding to prognostic variables before and after classification. Subsequently multivariate analysis showed that modified T stage was an independent significant predictor of cancer specific actuarial survival.ConclusionsPerirrenal fat infiltration in renal cell carcinoma should not be used to assign T category. In our series grading tumors pT3a lesser than 5,5 cm as pT1/pT2 TNM stage does not affect their prognostic value.  相似文献   
78.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
79.
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