首页 | 官方网站   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   7708篇
  免费   626篇
  国内免费   312篇
医药卫生   8646篇
  2024年   41篇
  2023年   162篇
  2022年   354篇
  2021年   455篇
  2020年   346篇
  2019年   318篇
  2018年   287篇
  2017年   299篇
  2016年   271篇
  2015年   286篇
  2014年   415篇
  2013年   591篇
  2012年   361篇
  2011年   363篇
  2010年   318篇
  2009年   297篇
  2008年   282篇
  2007年   279篇
  2006年   274篇
  2005年   227篇
  2004年   235篇
  2003年   210篇
  2002年   171篇
  2001年   163篇
  2000年   129篇
  1999年   111篇
  1998年   115篇
  1997年   89篇
  1996年   85篇
  1995年   87篇
  1994年   72篇
  1993年   67篇
  1992年   57篇
  1991年   72篇
  1990年   60篇
  1989年   55篇
  1988年   57篇
  1987年   47篇
  1986年   45篇
  1985年   69篇
  1984年   85篇
  1983年   44篇
  1982年   61篇
  1981年   54篇
  1980年   32篇
  1979年   30篇
  1978年   18篇
  1977年   37篇
  1976年   18篇
  1973年   13篇
排序方式: 共有8646条查询结果,搜索用时 15 毫秒
1.
2.
Paroxysmal dyskinesias (PxDs) are involuntary, episodic movements that include paroxysmal kinesigenic (PKD), paroxysmal nonkinesigenic (PNKD), and paroxysmal hypnogenic (PHD) varieties. Although most PxDs are primary (idiopathic or genetic), we found 17 of our 76 patients with PxD (22%) to have an identifiable cause for their PxD (10 men; mean age, 41.4 years). Causes included peripheral trauma (in three patients), vascular lesions (in four), central trauma (in four), kernicterus (in two), multiple sclerosis (in one), cytomegalovirus encephalitis (in one), meningovascular syphilis (in one), and migraine (in one). The latency from insult to symptom onset ranged from days (trauma) to 18 years (kernicterus), with a mean of 3 years. Nine patients had PNKD, two had PKD, five had mixed PKD/PNKD, and one had PHD. Hemidystonia was the most common expression of the paroxysmal movement disorder, present in 11 patients. Both of the patients with PKD had symptom durations of <5 minutes. Symptom duration ranged from 10 seconds to 15 days for PNKD and from 5 minutes to 45 minutes for mixed PKD/PNKD. There were no uniformly effective therapies, but anticonvulsant drugs, clonazepam, and botulinum toxin injections were the most beneficial. Awareness of the variable phenomenology and the spectrum of causes associated with secondary PxD will allow for more timely diagnosis and early intervention.  相似文献   
3.
10 patients with CLL and 2 with CML were treated with gradually increasing doses of 1 alpha(OH)D3, up to 4 micrograms daily during 6 wk. 3 patients with preleukemia and 1 with myelofibrosis were treated with 2 micrograms daily of 1 alpha(OH)D3 for a prolonged period up to 17 wk. The treatment with 1 alpha (OH)D3 did not result in changes of disease parameters in any of the patients under study. Receptor studies for 1,25(OH)2D3 were performed in 8 CLL patients and revealed only 1 patient with increased specific receptor binding capacity. The maximum tolerable dose of 1 alpha(OH)D3 varied individually, but was in the range of 2-4 micrograms daily.  相似文献   
4.
患者十六岁开始有逐渐加重的睡眠发作,伴有轻度不典型猝倒。14岁后出现入睡前幻觉,主要为鲜明生动的听幻觉,偶有幻视、幻嗅。幻觉严重时继发关系妄想和被害妄想,失去自知力。22年随访结果:患者精神状态良好,仍有轻度睡眠发作及入睡前幻觉,不影响日常工作和生活。对诊疗作了评价。  相似文献   
5.
本文介绍一种使继发性唇裂鼻畸形获得较好外形的新手术方法。术式包括切除偏曲的鼻中隔软骨,并将一片硅胶植入于中央作为鼻小柱支柱,从而矫正歪斜的鼻小柱和抬高鼻尖,使两侧鼻孔形态对称一致,用本法为11例单侧唇裂畸形较重者进行了整复,随访4个月至4年半。绝大多数(10/11)取得满意效果,未见有严重感染和变形等并发症。  相似文献   
6.
Sphingolipid metabolites in neural signalling and function   总被引:8,自引:0,他引:8  
Sphingolipid metabolites, such as ceramide, sphingosine, sphingosine-1-phosphate (S1P) and complex sphingolipids (gangliosides), are recognized as molecules capable of regulating a variety of cellular processes. The role of sphingolipid metabolites has been studied mainly in non-neuronal tissues. These studies have underscored their importance as signals transducers, involved in control of proliferation, survival, differentiation and apoptosis. In this review, we will focus on studies performed over the last years in the nervous system, discussing the recent developments and the current perspectives in sphingolipid metabolism and functions.  相似文献   
7.
张玲 《实用医技杂志》2005,12(18):2649-2650
文化休克(culture shock),又译为文化震撼或文化震惊,是指生活在某一种文化环境中的人初次进入到另一种文化环境,如到了不同的民族、社会群体中或地区甚至国家时所产生的思想混乱与心理上精神紧张综合征。新入校中专护生,由于文化环境的改变,往往会出现孤独、焦虑、无助等文化休克的种种表现,这些现象若不能及时得到解决,将不利于他们的全面健康状态的成长与发展。众所周知,WHO明确规定,健康不但是没有疾病和身体缺陷,还要有完整的生理、心理状态和良好的社会适应能力。因此,新入校中专护生这一特殊群体所产生的文化休克现象应引起学校有…  相似文献   
8.
In glaucomatous eyes refractory to medication, laser techniques and conventional drainage surgery, intraocular pressure is often high, and visual loss rapid. In this situation a reliable, robust artificial outflow system is required. Molteno has evolved a plastic tube and plate device combined with a fibrosis suppression medication regimen. Thirty-eight eyes of 32 patients with uncontrolled glaucoma were treated with the Molteno system. Six months after operation mean intraocular pressure had been reduced from 41.0 ± 13.6 to 16.2 ± 5.6 mmHg. Eighteen eyes had pressures of 20 mmHg or less on no hypotensive therapy, 17 on reduced treatment. Three eyes had a pressure of 21 to 35 mmHg on treatment at six months. The 13 aphakic eyes responded as well as 25 phakic eyes. Five eyes with rubeotic glaucoma demonstrated pressures of less than 20 mmHg without therapy, four eyes with traumatic glaucoma required continuing medication with three having pressures below 22 mmHg. Of the seven eyes with uveitic glaucoma, one was lost, two required maintenance therapy; five of six surviving eyes had pressures below 20 mmHg. Fifteen eyes with congenital or juvenile glaucoma achieved pressures below 20 mmHg, three of these with timolol drops, three with timolol and acetazolamide, and nine with no treatment. While seven of seven eyes with refractory primary open-angle glaucoma attained pressures below 20 mmHg. all seven needed continuing mild hypotensive therapy. Eleven eyes underwent a one-stage procedure, while 27 eyes required a two-stage operation. Twenty-eight eyes received fibrosis suppression medication after the second stage, and 24 maintained or improved their preoperative visual acuity. Results have been encouraging: in general the Molteno system is recommended as the second drainage operation in all glaucomatous eyes in which conventional therapy has failed, and as the primary surgical procedure (after laser techniques) in eyes with rubeotic and uveitic glaucoma. Ciliary body destructive procedures should be restricted to control of symptoms in blind eyes.  相似文献   
9.
The effects of calcium on parathyroid hormone (PTH) has further discovered in recent years. It has been known that calcium ion concentration in the extracellular fluid is a major determinant of PTH secretion. The relationship between serum intact PTH (iPTH) and calcium ion levels is described by a sigmoidal curve. The calcium concentration that produces half-maximal change in PTH release (the midpoint between maximal and minimal  相似文献   
10.
运用二元碱氮置换吸附红外光谱法、分子筛孔径分布测定技术、XPS技术,考察了丝光沸石表面酸性与孔结构的相互关系、钯在丝光沸石上分布情况和价态及其与沸石的相互作用。结果表明,随着丝光沸石脱铝程度的增加,表面出现大量不规整晶格,存在较多的次级孔道。强质子酸中心主要分布在它的“外表面”。钯在其表面富集,并与“外表面”上的质子酸中心协同作用,促进了轻质烷烃异构化反应。  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-23

京公网安备 11010802026262号