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   1175篇
  免费   57篇
  国内免费   1篇
耳鼻咽喉   39篇
儿科学   16篇
妇产科学   6篇
基础医学   533篇
口腔科学   12篇
临床医学   70篇
内科学   97篇
皮肤病学   2篇
神经病学   114篇
特种医学   80篇
外科学   117篇
综合类   11篇
预防医学   46篇
眼科学   5篇
药学   55篇
中国医学   2篇
肿瘤学   28篇
  2022年   7篇
  2021年   9篇
  2019年   7篇
  2018年   13篇
  2016年   18篇
  2015年   11篇
  2014年   17篇
  2013年   22篇
  2012年   29篇
  2011年   30篇
  2010年   16篇
  2009年   17篇
  2008年   22篇
  2007年   19篇
  2006年   22篇
  2005年   21篇
  2004年   21篇
  2003年   29篇
  2002年   26篇
  2001年   18篇
  2000年   19篇
  1999年   31篇
  1998年   11篇
  1996年   7篇
  1995年   14篇
  1992年   18篇
  1991年   12篇
  1990年   13篇
  1989年   8篇
  1988年   12篇
  1987年   9篇
  1986年   8篇
  1985年   8篇
  1983年   9篇
  1976年   8篇
  1975年   15篇
  1974年   12篇
  1969年   8篇
  1933年   54篇
  1932年   52篇
  1931年   46篇
  1930年   50篇
  1929年   36篇
  1928年   52篇
  1927年   36篇
  1926年   40篇
  1925年   43篇
  1924年   46篇
  1923年   26篇
  1922年   32篇
排序方式: 共有1233条查询结果,搜索用时 15 毫秒
101.
The function of insight is independent of content. Insight is the result of the assignment of meaning as distinct from finding meaning. Interpretation leads to insight which binds anxiety and lifts repression, thus providing relief of symptoms. Working is learning to apply the assigned meaning to new situations.  相似文献   
102.
Recent achievements in the development of multitargeted molecular inhibitors necessitate a better understanding of the contribution of activity against individual targets to their efficacy. SU11248, a small-molecule inhibitor targeting class III/V receptor tyrosine kinases, including the platelet-derived growth factor (PDGF) and vascular endothelial growth factor (VEGF) receptors, KIT and FLT3, exhibits direct effects on cancer cells as well as antiangiogenic activity. Here, we investigated the contributions of inhibiting individual SU11248 target receptors to its overall antitumor efficacy in tumor models representing diverse signaling paradigms. Consistent with previous results, SU11248 was highly efficacious (frequently cytoreductive) in all models tested. To elucidate the specific contributions of inhibition of PDGF and VEGF receptors to the in vivo efficacy of SU11248, we employed two selective inhibitors, SU10944 (VEGF receptor inhibitor) and Gleevec (PDGF receptor inhibitor). SU10944 alone induced a tumor growth delay in all models evaluated, consistent with a primarily antiangiogenic mode of action. In contrast, Gleevec resulted in modest growth inhibition in tumor models in which the cancer cells expressed its targets (PDGFRbeta and KIT), but was not efficacious against tumors not driven by these target receptor tyrosine kinases. Strikingly, in all but one tumor model evaluated, the antitumor efficacy of SU10944 combined with Gleevec was similar to that of single-agent SU11248, and was greatly superior to that of each compound alone, indicating that the antitumor potency of SU11248 in these models stems from combined inhibition of both PDGF and VEGF receptors. The one exception was a model driven by an activated mutant of FLT3, in which the activity of SU11248, which targets FLT3, was greater than that of SU10944 plus Gleevec. Moreover, SU10944 combined with Gleevec inhibited tumor neoangiogenesis to an extent comparable to that of SU11248. Thus, the potent efficacy of SU11248 in models representing diverse signaling paradigms results from simultaneous inhibition of individual target receptors expressed both in cancer cells and in the tumor neovasculature, supporting the hypothesis that multitargeted inhibitors have the cumulative antitumor efficacy of combined single-target inhibitors.  相似文献   
103.
104.
We measured six phenolic compounds by HPLC, the total phenolic content by Folin-Ciocalteu, and antioxidative activities by three methods in the sweet potato plant and in home processed roots. Total phenolic content was highest in the leaves. Eight root varieties were partitioned and analyzed for phenolics. The stem end of the root had significantly more phenolics. In all samples the predominant chlorogenic acids were 5-caffeoylquinic acid (5-CQA) and 3,5-diCQA. 3,4-diCQA was present in significant amounts in the leaves and the flower, and 4,5-diCQA in the leaves. Six home-processing/cooking techniques reduced phenolic content from 7% (baking) to ∼40% (deep frying/boiling). High correlations were observed between phenolic compounds determined by HPLC and Folin-Ciocalteu, radical scavenging activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH), and oxidative activity by ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. The results show that there is a large variation in phenolics among sweet potato varieties and different parts of the plant and that high-phenolic sweet potato leaves, widely consumed in Asian countries as a vegetable, should be considered for diets of other countries.  相似文献   
105.

Objective

To develop a Vaccine Confidence Index (VCI) that is capable of detecting variations in parental confidence towards childhood immunizations centered on trust and concern issues that impact vaccine confidence.

Methods

We used a web-based national poll of 893 parents of children <7?years in 2016 to assess the measures created for the Emory VCI (EVCI). EVCI measures were developed using constructs related to vaccine confidence identified by the U.S. National Vaccine Advisory Committee (i.e., “Information Environment”, “Trust”, “Healthcare Provider”, “Attitudes and Beliefs”, and “Social Norms”). Reliability for EVCI was assessed using Cronbach’s alpha. Using the variables related to each of the constructs, we calculated an overall EVCI score that was then assessed against self-reported childhood vaccine receipt using chi-square and the Cochrane-Armitage trend tests.

Results

Respondents’ EVCI scores could range from 0 to 24, and the full range of values was observed in this sample (Mean?=?17.5 (SD 4.8)). EVCI scores were significantly different (p?≤?0.006 for all comparisons) between parents who indicated their child(ren) received routinely recommended vaccines compared with parents who indicated they had delayed or declined recommended immunizations. There was also a significant, consistent association between higher EVCI scores and greater reported vaccine receipt.

Conclusions

We developed EVCI to reliably measure parental vaccine confidence, with individuals’ scores linked to parental vaccine-related attitudes, intentions, and behaviors. As such, EVCI may be a useful tool for future monitoring of both population and individual confidence in childhood immunization.  相似文献   
106.

Purpose

The pituitary gland is an unusual site for metastatic spread, but as patients with metastatic malignancy are living longer, it may become more prevalent. Compression of important anatomy adjacent to the sella may produce disabling symptoms and endocrine derangement, leading to significant morbidity.

Methods

An ambispective review of patient records between 2013 and 2017 from three neurosurgical centres was performed. After identifying cases, further investigation was performed to evaluate patient demographic, symptoms at presentation, radiological and histological findings, management, and outcome.

Results

Our investigation identified 12 patients with pituitary metastasis. The average age of the cases was 63.4 years, with breast (n?=?4) and lung (n?=?4) being the most common primary cancers. In half the cases there was a history of metastatic disease, while in one-quarter of cases, pituitary symptoms were the first sign of malignancy. Adenohypophyseal dysfunction (83%), diabetes insipidus (DI) (75%), headache (67%) and visual field defects (67%) were the most common findings at presentation. Glucocorticoid replacement increased the sensitivity for diagnosis of DI. All cases were contrast enhancing on MRI and the endoscopic trans-sphenoidal approach was preferred for biopsy and debulking.

Conclusions

The pituitary should not be overlooked as a site of metastasis and sellar symptoms may be the first presentation of neoplastic disease. Any biochemical or clinical sign of pituitary pathology in a patient with known cancer should raise suspicion for sellar metastasis. Moreover, the development of DI or ophthalmoplegia from any pituitary lesion is suggestive of metastatic disease even in patients with no known primary.
  相似文献   
107.
Satietin is a putative satiety agent when given either peripherally or intracerebroventricularly (ICV). In the present study male Sprague Dawley rats were fitted with chronic third ventricle cannulas. After recovery, Alzet seven day osmotic pumps were inserted subcutaneously and tubing was connected to the cannula. Rats were then infused ICV with saline or semi-purified human satietin (25 micrograms/day; 1 microliter/hr). In the satietin group, daily chow intake was reduced (p less than 0.05) on days 1 and 2, recovered to control levels on days 4 and 5 and again declined (p less than 0.05) on days 6-8. During this latter period the satietin treated animals appeared ill. The satietin group's water intake paralleled food consumption, whereas the groups' water/food intake ratios did not differ. Satietin infusions decreased (p less than 0.01) the rats' body weight 42 grams by day 4, whereas the control group's weight remained constant. Even during the period where the satietin group's food intake returned to control levels they continued to lose weight. Running wheel activity was reduced throughout the satietin infusion period even when food and water ingestion had returned to control levels. The data suggest that semi-purified human satietin, when tested in rats, is an anorexogenic agent, however, its continuous use quickly produces tolerance and later what may be a cross-species allergic reaction (due to the satietin itself or a contaminant). The appropriateness of testing semi-purified satietin in the rat model is questioned.  相似文献   
108.
109.
110.
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