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   14877篇
  免费   1016篇
  国内免费   48篇
耳鼻咽喉   188篇
儿科学   409篇
妇产科学   396篇
基础医学   2535篇
口腔科学   228篇
临床医学   1529篇
内科学   2516篇
皮肤病学   323篇
神经病学   1743篇
特种医学   606篇
外国民族医学   1篇
外科学   1574篇
综合类   104篇
一般理论   10篇
预防医学   1191篇
眼科学   282篇
药学   1052篇
中国医学   44篇
肿瘤学   1210篇
  2023年   76篇
  2022年   101篇
  2021年   270篇
  2020年   218篇
  2019年   301篇
  2018年   302篇
  2017年   237篇
  2016年   354篇
  2015年   370篇
  2014年   497篇
  2013年   636篇
  2012年   992篇
  2011年   983篇
  2010年   613篇
  2009年   568篇
  2008年   907篇
  2007年   903篇
  2006年   871篇
  2005年   820篇
  2004年   802篇
  2003年   825篇
  2002年   772篇
  2001年   154篇
  2000年   140篇
  1999年   186篇
  1998年   213篇
  1997年   163篇
  1996年   119篇
  1995年   120篇
  1994年   114篇
  1993年   115篇
  1992年   104篇
  1991年   86篇
  1990年   98篇
  1989年   83篇
  1988年   78篇
  1987年   62篇
  1985年   76篇
  1984年   58篇
  1983年   60篇
  1982年   63篇
  1981年   62篇
  1980年   43篇
  1979年   61篇
  1978年   54篇
  1977年   48篇
  1976年   51篇
  1974年   43篇
  1972年   49篇
  1955年   45篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field.  相似文献   
2.
3.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
4.
5.
This paper takes a somewhat slant perspective on flourishing and care in the context of suffering, death and dying, arguing that care in this context consists principally of ‘acts of work and courage that enable flourishing’. Starting with the perception that individuals, society and health care professionals have become dulled to death and the process of dying in Western advanced health systems, it suggests that for flourishing to occur, both of these aspects of life need to be faced more directly. The last days of life need to be ‘undulled’. Reflections upon the experiences of the author as carer and daughter in the face of her mother’s experience of death are used as basis for making suggestions about how care systems and professionals might better assist people in dealing with ‘the most grown up thing’ humans ever do, which is to die.  相似文献   
6.
7.
In some diseases, such as multiple sclerosis, lesion counts obtained from magnetic resonance imaging (MRI) are used as markers of disease progression. This leads to longitudinal, and typically overdispersed, count data outcomes in clinical trials. Models for such data invariably include a number of nuisance parameters, which can be difficult to specify at the planning stage, leading to considerable uncertainty in sample size specification. Consequently, blinded sample size re-estimation procedures are used, allowing for an adjustment of the sample size within an ongoing trial by estimating relevant nuisance parameters at an interim point, without compromising trial integrity. To date, the methods available for re-estimation have required an assumption that the mean count is time-constant within patients. We propose a new modeling approach that maintains the advantages of established procedures but allows for general underlying and treatment-specific time trends in the mean response. A simulation study is conducted to assess the effectiveness of blinded sample size re-estimation methods over fixed designs. Sample sizes attained through blinded sample size re-estimation procedures are shown to maintain the desired study power without inflating the Type I error rate and the procedure is demonstrated on MRI data from a recent study in multiple sclerosis.  相似文献   
8.
9.
10.
Carcinosarcomas are biphasic tumors composed of admixed malignant epithelial and mesenchymal components. Numerous terms have been used to name such neoplasms; therefore, terminological confusion is frequent. Most examples of carcinosarcomas are encountered in non‐cutaneous sites, with approximately 100 cases of cutaneous carcinosarcomas reported so far in the English literature. Although different theories have been suggested to explain the occurrence of these peculiar neoplasms, histogenetic mechanisms should be better hypothesized depending on each individual case. Even though prognosis tends to be related to the specific components of the lesion, especially the epithelial one, it seems that cases of cutaneous localization usually have a better outcome. We report an exceedingly rare case of syringocystadenocarcinoma papilliferum which showed an atypical stroma with sarcomatoid appearance, and highlight that the terminology used for this spectrum of lesions is disorganized and confusing.  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