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   876篇
  免费   61篇
  国内免费   1篇
耳鼻咽喉   6篇
儿科学   45篇
妇产科学   9篇
基础医学   161篇
口腔科学   16篇
临床医学   84篇
内科学   186篇
皮肤病学   43篇
神经病学   73篇
特种医学   25篇
外科学   55篇
综合类   9篇
一般理论   3篇
预防医学   71篇
眼科学   35篇
药学   77篇
中国医学   1篇
肿瘤学   39篇
  2023年   10篇
  2022年   16篇
  2021年   43篇
  2020年   21篇
  2019年   29篇
  2018年   33篇
  2017年   9篇
  2016年   20篇
  2015年   31篇
  2014年   29篇
  2013年   50篇
  2012年   77篇
  2011年   52篇
  2010年   37篇
  2009年   24篇
  2008年   54篇
  2007年   67篇
  2006年   51篇
  2005年   38篇
  2004年   43篇
  2003年   36篇
  2002年   41篇
  2001年   9篇
  2000年   7篇
  1999年   13篇
  1998年   8篇
  1997年   4篇
  1996年   7篇
  1995年   2篇
  1994年   6篇
  1993年   4篇
  1992年   2篇
  1991年   2篇
  1990年   2篇
  1989年   5篇
  1988年   4篇
  1987年   2篇
  1986年   3篇
  1984年   4篇
  1978年   2篇
  1976年   2篇
  1973年   3篇
  1933年   5篇
  1931年   2篇
  1928年   1篇
  1927年   1篇
  1925年   3篇
  1922年   1篇
  1912年   2篇
  1911年   1篇
排序方式: 共有938条查询结果,搜索用时 31 毫秒
31.
IGF-I has been suggested to be of importance for cardiovascular structure and function, but the relative role of locally produced and liver-derived endocrine IGF-I remains unclear. Using the Cre-LoxP recombination system, we have previously created transgenic mice with a liver-specific, inducible IGF-I knockout (LI-IGF-I-/-). To examine the role of liver-derived IGF-I in cardiovascular physiology, liver-derived IGF-I was inactivated at 4 wk of age, resulting in a 79% reduction of serum IGF-I levels. At 4 months of age, systolic blood pressure (BP) was increased in LI-IGF-I-/- mice. Echocardiography showed increased posterior wall thickness in combination with decreased stroke volume and cardiac output, whereas other systolic variables were unchanged, suggesting that these cardiac effects were secondary to increased peripheral resistance. Acute nitric oxide-synthase inhibition increased systolic BP more in LI-IGF-I-/- mice than in control mice. LI-IGF-I-/- mice showed impaired acetylcholine-induced vasorelaxation in mesenteric resistance vessels and increased levels of endothelin-1 mRNA in aorta. Thus, the increased peripheral resistance in LI-IGF-I-/- mice might be attributable to endothelial dysfunction associated with increased expression of endothelin-1 and impaired vasorelaxation of resistance vessels. In conclusion, our findings suggest that liver-derived IGF-I is involved in the regulation of BP in mice.  相似文献   
32.
33.
34.
Collagen membranes and bone substitute are popular biomaterials in guided tissue regeneration for treatment of traumatized or diseased periodontal tissue. Development of these biomaterials starts in monolayer cell culture, failing to reflect in vivo tissue organization. Spheroid cultures potentially mimic in vivo tissues in structure and functionality. This study aims to compare gingiva cell (GC) monolayers and spheroids to ex vivo gingiva. Human GC monolayers, spheroids and gingiva ex vivo tissues were cultured on plastic surfaces, collagen membranes or bone substitute. Hematoxylin–eosin (HE) staining, immunohistochemistry for KI67 and caspase 3 (CASP3), resazurin‐based toxicity assays, quantitative polymerase chain reaction for collagen I (COL1A1), vascular endothelial growth factor (VEGF), angiogenin (ANG), interleukin (IL)6 and IL8 and ELISA for COL1A1, VEGF, ANG, IL6 and IL8 were performed in all cultures. Morphology was different in all culture set‐ups. Staining of KI67 was positive in monolayers and staining of CASP3 was positive in spheroids. All culture set‐ups were viable. COL1A1 production was modulated in monolayers and ex vivo tissues at mRNA levels, VEGF in monolayers and ex vivo tissues at mRNA levels and in spheroids at protein levels, ANG in spheroids at mRNA levels and in monolayers and spheroids at protein levels, IL6 in monolayers and spheroids at mRNA levels and in spheroids and ex vivo tissues at protein levels and IL8 in monolayers and ex vivo tissues at mRNA levels. Modulations were surface‐dependent. In conclusion, each culture model is structurally and functionally different. Neither GC monolayers nor spheroids mimicked gingiva ex vivo tissue in all measured aspects.  相似文献   
35.
In late life, traumas may act cumulatively to exacerbate vulnerability to post‐traumatic stress disorder (PTSD). PTSD is also a risk factor for cognitive decline. Major neurocognitive disorder (MND) can be associated with worsening of already controlled PTSD symptoms, late‐life resurgence or de novo emergence. Misidentifying PTSD symptoms in MND can have negative consequences for the patient and families. We review the literature pertaining to PTSD and dementia and describe five cases referred for consultation in geriatric psychiatry initially for behavioural and psychological symptoms of dementia (BPSD), which were eventually diagnosed and treated as PTSD in MND subjects. We propose that certain PTSD symptoms in patients with MND are misinterpreted as BPSD and therefore, not properly addressed. For example, flashbacks could be interpreted as hallucinations, hypervigilance as paranoia, nightmares as sleep disturbances, and hyperreactivity as agitation/aggression. We suggest that better identification of PTSD symptoms in MND is needed. We propose specific recommendations for care, namely: clarifying diagnosis by distinguishing PTSD symptoms coexisting with different types of dementia from a specific dementia symptom (BPSD), gathering a detailed history of the trauma in order to personalise non‐pharmacological interventions, adapting psychotherapeutic strategies to patients with dementia, using selective serotonin reuptake inhibitors as first‐line treatment and avoiding antipsychotics and benzodiazepines. Proper identification of PTSD symptoms in patients with MND is essential and allows a more tailored and efficient treatment, with decrease in inappropriate use of physical and chemical restraints.  相似文献   
36.
37.
Anterior cervical fusion and Caspar plate stabilization for cervical trauma   总被引:34,自引:0,他引:34  
A technique for anterior cervical iliac graft fusion with standardized, commercially available screw and plate fixation (Caspar plating) has been developed. The step-by-step procedure, as well as the instruments designed to facilitate the procedure, are described in this report. Sixty cases of cervical trauma (fractures, subluxations, ligamentous instability, or a combination of these problems) were treated with Caspar plating. All patients obtained fusion, and stability was achieved immediately after surgery without external stabilization. No unusual surgical complications occurred, and the most dreaded complication of dural penetration by drilling or screw placement was not observed. This report details the neurological presentation, anatomical lesions, surgical therapy, and outcome of these patients. Caspar plating combines the advantage of an anterior surgical approach with immediate postoperative stabilization without external stabilization. This advantage persists even in the presence of posterior ligamentous instability. The technique is an important addition to the surgical treatment of cervical trauma.  相似文献   
38.
Excessive consumption of sugar-rich foods is currently one of the most important factors that has led to the development of the global pandemic of obesity. On the other hand, there is evidence that obesity contributes to reduced sensitivity to sweet taste and hormonal changes affecting appetite, leading to an increased craving for sweets. A high intake of sugars increases the caloric value of the diet and, consequently, leads to weight gain. Moreover, attention is drawn to the concept of the addictive properties of sugar and sugary foods. A potential method to reduce the energy value of diet while maintaining the sweet taste is using non-nutritive sweeteners (NNS). NNS are commonly used as table sugar substitutes. This wide group of chemical compounds features high sweetness almost without calories due to its high sweetening strength. NNS include aspartame, acesulfame-K, sucralose, saccharin, cyclamate, neohesperidin dihydrochalcone (neohesperidin DC), neotame, taumatin, and advantame. The available evidence suggests that replacing sugar with NNS may support weight control. However, the effect of NNS on the regulation of appetite and sweet taste perception is not clear. Therefore, the review aimed to summarize the current knowledge about the use of NNS as a potential strategy for weight loss and their impact on sweet taste perception. Most studies have demonstrated that consumption of NNS-sweetened foods does not increase sweetness preference orenergy intake. Nonetheless, further research is required to determine the long-term effects of NNS on weight management.  相似文献   
39.
40.
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