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   5149篇
  免费   255篇
  国内免费   12篇
耳鼻咽喉   31篇
儿科学   64篇
妇产科学   82篇
基础医学   725篇
口腔科学   166篇
临床医学   372篇
内科学   1249篇
皮肤病学   189篇
神经病学   344篇
特种医学   132篇
外科学   859篇
综合类   25篇
预防医学   159篇
眼科学   138篇
药学   393篇
中国医学   14篇
肿瘤学   474篇
  2023年   30篇
  2022年   64篇
  2021年   97篇
  2020年   47篇
  2019年   84篇
  2018年   97篇
  2017年   84篇
  2016年   94篇
  2015年   110篇
  2014年   142篇
  2013年   202篇
  2012年   302篇
  2011年   329篇
  2010年   166篇
  2009年   155篇
  2008年   235篇
  2007年   241篇
  2006年   277篇
  2005年   277篇
  2004年   244篇
  2003年   217篇
  2002年   238篇
  2001年   177篇
  2000年   172篇
  1999年   156篇
  1998年   59篇
  1997年   46篇
  1996年   48篇
  1995年   36篇
  1994年   31篇
  1993年   29篇
  1992年   85篇
  1991年   84篇
  1990年   92篇
  1989年   82篇
  1988年   89篇
  1987年   68篇
  1986年   65篇
  1985年   47篇
  1984年   43篇
  1983年   32篇
  1981年   20篇
  1980年   14篇
  1979年   17篇
  1978年   17篇
  1974年   18篇
  1973年   14篇
  1972年   24篇
  1969年   18篇
  1967年   13篇
排序方式: 共有5416条查询结果,搜索用时 15 毫秒
101.
102.
BackgroundIt is critical to have an accurate measurement of solid tumor size in order to predict the invasiveness of small lung adenocarcinomas. Some lesions cannot be measured accurately via High-resolution computed tomography (HRCT) due to their irregular shape and unclear borders. For this reason, we evaluated the relative efficacy of three-dimensional (3D) CT for predicting invasive adenocarcinoma.MethodsWe evaluated 195 patients with clinical stage IA adenocarcinomas, including 109 with lesions documented as invasive that were surgically resected at our institute during 2017. All lesions were categorized as either (I) lesions that were difficult to evaluate (i.e., hazy lesions; HL) or (II) more typical lesions (TL). The relationships between solid tumor size as determined by HRCT, solid tumor volume as determined by 3D CT and pathologic diagnosis were evaluated.ResultsFifty-seven patients (29%) were diagnosed with HL. We set the cut-off value for the solid volume at 225 mm3 as predictive for invasive adenocarcinoma. When evaluating all 195 patients as a group, the accuracy, sensitivity, and specificity based on the solid tumor volume were similar to those based on the solid tumor size. When we limit our analysis to the HL group, the specificity based on solid tumor volume (65.5%) was higher than that based on solid tumor size (44.8%) with a difference that approached statistical significance (P=0.070).Conclusions3D CT was equivalent to HRCT for predicting invasive adenocarcinoma and may be particularly useful for diagnosing lesions that are difficult to evaluate on HRCT.  相似文献   
103.
104.
105.
Biliary adenofibroma (BAF) is a rare, benign liver tumor. Herein, we report a case of BAF with histological features of imminent malignant changes. Ultrasound and CT revealed a solid 2.5-cm mass in the right liver lobe. The patient was asymptomatic and had no past medical history including liver disease. A general examination that included the abdomen and the laboratory data were normal. Because of the increase of its size, this tumor was surgically resected. Grossly, a 3.5-cm nodular mass abutted on the hepatic capsule was found, and its cut surface showed a well-circumscribed, whitish, and firm lesion that showed microcystic changes in the periphery and solid changes in the central parts. Histologically, the tumor showed a proliferation of tubulocystic structures embedded in a fibrous stroma. Microcysts were prevalent in the periphery, while tubular components with abundant fibrous stroma were in the central parts. The tubules were variably dilated and branched. This case closely resembled the previously reported cases of BAF, except that there were complicated papillary projections with fine fibrovascular cores in some of the microcysts and that the epithelial component in papillary projections showed dysplastic changes and increased cellular proliferative activities, implicating ominous features of imminent malignant changes. These dysplastic and papillary changes may be an intermediate lesion leading to malignancy, which have occasionally been reported in BAF.  相似文献   
106.
107.
108.
109.

Background

In TKA, soft tissue balance (the joint gap) depends on the amount of resected bone and soft tissue release. Some studies report preoperative bony deformity correlates with soft tissue balance evaluated intraoperatively and that the medial tissues are contracted with varus deformity. However, these studies did not take into account the amount of resected bone and did not describe whether the soft tissue was tight or loose. Therefore, it remains unclear whether in varus deformity the soft tissues on the medial side are contracted.

Questions/purposes

We compared (1) intraoperative joint gap, (2) amount of resected bone, and (3) intraoperative soft tissue laxity on the lateral and medial sides according to severity of preoperative varus deformity.

Methods

We retrospectively reviewed 70 patients with osteoarthritis and varus deformities who underwent 90 TKAs. We retrospectively divided the 90 knees into three groups according to degree of preoperative alignment: mild varus group (< 10°), moderate varus group (10°–20°), and severe varus group (> 20°). To evaluate intraoperative soft tissue tension, we calculated the soft tissue gap by subtracting the thickness of the resected bone from the joint gaps on the medial and lateral sides, respectively. We then explored the relationship between the soft tissue gap and preoperative alignment.

Results

The lateral soft tissue gap was larger in the severe varus group than in the mild and moderate varus groups. The medial soft tissue gap was larger in the severe varus group than in the mild varus group, but there were no differences in the medial joint gaps among the groups.

Conclusions

After the bone is resected, the soft tissue on the lateral side is more lax; however, the soft tissue on the medial side is not shorter with greater preoperative varus deformity.  相似文献   
110.

Purposes

The purpose of this study was to show the clinical features of up-front surgery of the primary tumor in asymptomatic patients with incurable colorectal PC.

Methods

Forty-six patients that were diagnosed between 1998 and 2007 with asymptomatic colorectal PC who could not be successfully cured by surgery were assessed retrospectively.

Results

A univariate analysis revealed the presence of liver metastases, without the use of oxaliplatin (OX)/irinotecan (IRI) and without a primary tumor resection to be poor prognostic factors for survival (p = 0.044, p = 0.030, p < 0.001, respectively). According to a multivariate analysis, no use of OX/IRI and no primary tumor resection, were found to be independent poor prognostic factors for survival (HR 2.57; p = 0.047, HR 6.62; p = 0.003, respectively). The median survival time of patients treated with and without OX/IRI was 18 and 7 months, respectively. The median survival time of patients with and without primary tumor resection was 10 and 2 months, respectively. The number of patients needing surgical intervention for intestinal obstruction after surgery significantly increased in patients treated with OX/IRI (p = 0.001).

Conclusion

Improvement of survival may be related to widespread use of modern systemic chemotherapy and primary tumor resection. However, an increased number of patients that needed surgery for an intestinal obstruction were observed, even after up-front surgery, when patients were treated with modern systemic chemotherapy.  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