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   1683篇
  免费   79篇
  国内免费   4篇
耳鼻咽喉   10篇
儿科学   48篇
妇产科学   29篇
基础医学   206篇
口腔科学   37篇
临床医学   114篇
内科学   420篇
皮肤病学   34篇
神经病学   167篇
特种医学   32篇
外科学   147篇
综合类   18篇
一般理论   1篇
预防医学   152篇
眼科学   31篇
药学   149篇
中国医学   10篇
肿瘤学   161篇
  2024年   2篇
  2023年   17篇
  2022年   37篇
  2021年   55篇
  2020年   42篇
  2019年   32篇
  2018年   35篇
  2017年   23篇
  2016年   42篇
  2015年   35篇
  2014年   55篇
  2013年   82篇
  2012年   117篇
  2011年   122篇
  2010年   66篇
  2009年   44篇
  2008年   76篇
  2007年   93篇
  2006年   94篇
  2005年   105篇
  2004年   109篇
  2003年   98篇
  2002年   121篇
  2001年   27篇
  2000年   14篇
  1999年   19篇
  1998年   22篇
  1997年   17篇
  1996年   13篇
  1995年   10篇
  1994年   10篇
  1993年   11篇
  1992年   11篇
  1991年   9篇
  1990年   15篇
  1989年   15篇
  1988年   10篇
  1987年   10篇
  1986年   10篇
  1985年   6篇
  1983年   9篇
  1982年   2篇
  1981年   2篇
  1980年   6篇
  1978年   3篇
  1977年   3篇
  1972年   1篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
排序方式: 共有1766条查询结果,搜索用时 15 毫秒
51.
Lysophosphatidylcholine (LPC) is metabolized from a membrane phospholipid and modulates a variety of channels in the plasma membrane (PM). We examined LPC modulation of cardiac ryanodine receptor (RyR) channels in the sarcoplasmic reticulum (SR) using the planar lipid bilayer method to measure the single-channel currents. Micromolar concentrations of LPC increased the open probability of the reconstituted RyR channels irrespective of whether LPC was added to the cis or trans chamber. LPC also increased the membrane capacitance of the bilayer. The effects of LPC contrasted well with those of sphingosylphosphorylcholine (SPC). Taken together, these results suggest that amphipathic lipid LPC does not bind directly to the RyR channel protein, but rather, is incorporated into the bilayer membrane and activates the channel. Thus, we consider cell membrane-derived LPC to be a putative endogenous mediator that activates not only plasma membrane channels but also RyR channels and induces arrhythmogenic Ca2+ mobilization in cardiomyocytes.  相似文献   
52.
53.
Lignans are widely distributed in plants and exhibit significant pharmacological effects, including anti-tumor and antioxidative activities. Here, we describe the total synthesis of schizandriside (1), a compound we previously isolated from Saraca asoca by monitoring antioxidative activity using the 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. Starting from a tandem Michael-aldol reaction, the lignan skeleton was synthesized in 6 steps, including a cyclization step. To determine the stereochemistry of 1, we synthesized the natural product (±)-isolariciresinol (18) from alcohol 17. Comparison of the spectral data showed good agreement. Glycosylation was investigated using four different glycosyl donors. Only the Koenigs–Knorr condition using silver trifluoromethanesulfonate with 1,1,3,3-tetramethylurea provided the glycosylated product. Deprotection and purification using reverse-phase high-performance liquid chromatography gave schizandriside (1) and its diastereomer saracoside (2). Synthesized 1, 2 and 18 showed antioxidant activity with IC50?=?34.4, 28.8, 53.0 μM, respectively.  相似文献   
54.
Journal of Natural Medicines - A new amide, named dehydropropylpantothenamide (1), was obtained by a co-culture of Nocardia tenerifensis IFM 10554T in the presence of the mouse macrophage-like cell...  相似文献   
55.
Graefe's Archive for Clinical and Experimental Ophthalmology - To assess spontaneous blinking and anomalous eyelid movements in patients with hemifacial spasm with an emphasis on interocular...  相似文献   
56.
This paper documents the case of a female Japanese patient with infantile focal epilepsy, which was different from benign infantile seizures, and a family history of infantile convulsion and paroxysmal choreoathetosis. The patient developed partial seizures (e.g., psychomotor arrest) at age 14 months. At the time of onset, interictal electroencephalography (EEG) showed bilateral parietotemporal spikes, but the results of neurologic examination and brain magnetic resonance imaging were normal. Her seizures were well controlled with carbamazepine, and she had a normal developmental outcome. EEG abnormalities, however, persisted for more than 6 years, and the spikes moved transiently to the occipital area and began to resemble the rolandic spikes recognized in benign childhood epilepsy. Her father had paroxysmal kinesigenic dyskinesia, with an onset age of 6 years, and her youngest sister had typical benign infantile seizures. Genetic analysis demonstrated that all affected members had a heterozygous mutation of c.649_650insC in the proline-rich transmembrane protein-2 (PRRT2) gene. This case indicates that the phenotypic spectrum of infantile seizures or epilepsy with PRRT2-related pathology may be larger than previously expected, and that genetic investigation of the effect of PRRT2 mutations on idiopathic seizures or epilepsy in childhood may help elucidate the pathological backgrounds of benign childhood epilepsy.  相似文献   
57.
58.
Falls among older people are usually the result of several causes combined. Identifying all the fall-related factors that apply to a particular individual and providing comprehensive multifactorial intervention is recommended for the prevention of falls among older people. However, the overall net benefit of multifactorial intervention in preventing falls is small, and it does not appear to improve fall-related outcomes, such as the number of fall-related injuries. Therefore, we might require new perspectives to overcome this situation. Here, we raise two novel strategies for fall prevention among older people. One is using physical therapists more actively. The other is using aromatherapy for stabilization of older people. Physical therapists should carry out detailed gait assessment and caregiver education. Aromatherapy is effective in improving balance and mental stability in older people. To overcome refractory geriatric syndrome, there is no choice but to eliminate all preconceived ideas before choosing the best fall prevention strategies. Geriatr Gerontol Int 2021; 21: 445–450 .  相似文献   
59.
BACKGROUND: Pouchitis is a major long-term complication of ileal pouch-anal anastomosis for ulcerative colitis. The aim of this study is to investigate the efficacy of leukocytapheresis for the treatment of active pouchitis. METHODS: Eight patients with active pouchitis received leukocytapheresis weekly for 5 weeks in an open-label treatment protocol together with baseline therapy. RESULTS: Patients showed significant improvement in their pouchitis disease activity index scores, from 9.5 (range, 8-10) to 4.0 (range, 2-8) (P < 0.05). Six (75%) of the 8 treated patients achieved remission. No adverse events were observed. CONCLUSIONS: Leukocytapheresis therapy could be a new therapeutic strategy for patients with pouchitis after ileal pouch-anal anastomosis for ulcerative colitis. These encouraging results lead us to propose a randomized controlled trial.  相似文献   
60.
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