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   11544篇
  免费   497篇
  国内免费   74篇
耳鼻咽喉   370篇
儿科学   483篇
妇产科学   526篇
基础医学   778篇
口腔科学   422篇
临床医学   986篇
内科学   2795篇
皮肤病学   269篇
神经病学   618篇
特种医学   447篇
外科学   2783篇
综合类   170篇
预防医学   246篇
眼科学   404篇
药学   412篇
中国医学   28篇
肿瘤学   378篇
  2023年   90篇
  2022年   158篇
  2021年   334篇
  2020年   204篇
  2019年   242篇
  2018年   310篇
  2017年   256篇
  2016年   403篇
  2015年   436篇
  2014年   560篇
  2013年   703篇
  2012年   879篇
  2011年   833篇
  2010年   543篇
  2009年   508篇
  2008年   812篇
  2007年   904篇
  2006年   794篇
  2005年   795篇
  2004年   663篇
  2003年   576篇
  2002年   481篇
  2001年   124篇
  2000年   67篇
  1999年   67篇
  1998年   55篇
  1997年   36篇
  1996年   41篇
  1995年   31篇
  1994年   20篇
  1993年   16篇
  1992年   27篇
  1991年   16篇
  1990年   13篇
  1989年   11篇
  1988年   11篇
  1987年   11篇
  1986年   8篇
  1985年   9篇
  1984年   8篇
  1983年   3篇
  1982年   4篇
  1980年   4篇
  1979年   5篇
  1974年   4篇
  1971年   4篇
  1970年   4篇
  1968年   3篇
  1967年   8篇
  1966年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Background Hydatid disease is the most severe helminthic zoonosis, with an important public health problem especially in rural areas in Turkey. The aim of this study was to review the problems and advantages encountered in surgical treatment of 43 patients who were ventilated with one-lung ventilation during last four years. Methods Patients, operated with one-lung ventilation, constitute the study group. Data related to symptoms, radiographic findings, performed surgical procedures, perioperative and postoperative morbidity, hospitalization time, and cyst recurrence were collected from each individual's records. Results Cystotomy and capitonnage were performed in all cases. Perioperative complications were seen in 5 patients. Four of these 5 patients had double-lumen endotracheal tube malpositioning. In one patient hypoxemia developed. The most common postoperative complication was atelectasis. One patient had recurrent cysts. There was no perioperative or postoperative death. Conclusions We prefer cystotomy and capitonnage because it is a fast and effective technique with limited postoperative complications. One-lung ventilation prevents the exposure of lower lung areas from massive aspiration, which may cause acute obstruction of airways, and contamination by cyst contents from the operative part of the lung that causes recurrent disease. One-lung ventilation in pulmonary hydatid cyst surgery may be preferred owing to lower mortality and morbidity rates.  相似文献   
5.
OBJECTIVE: To evaluate the possible effects of sex and age on strength-duration time constant (SDTC). METHODS: The SDTC of 126 healthy volunteers was measured following stimulation of right median nerve at the wrist. Variations in values were evaluated according to sex and age. RESULTS: The SDTC was 438.6+/-114.5 micros in women and 396.2+/-90.3 in men (P=.023). In men, as age increased, so did SDTC. However, this was not true in women. Comparing the values of women and men, aged below 40, demonstrated a difference in excitability, confined to younger patients. CONCLUSIONS: As SDTC depends on the biophysical properties of the axonal membrane and can provide some information about Na(+) channel function, these data raise the possibility of a difference in Na(+) channel function between men and women and a difference in the conductance with age. SIGNIFICANCE: The age- and sex-related differences shown in this study suggest a possible biochemical or hormonal influence on axonal excitability.  相似文献   
6.
Adrenergic signalling between rat taste receptor cells   总被引:2,自引:0,他引:2  
In taste buds, synaptic transmission is traditionally thought to occur from taste receptor cells to the afferent nerve. This communication reports the novel observation that taste receptor cells respond to adrenergic stimulation. Noradrenaline application inhibited outward potassium currents in a dose-dependent manner. This inhibition was mimicked by the β agonist isoproterenol and blocked by the β antagonist propranolol. The α agonists clonidine and phenylephrine both inhibited the potassium currents and elevated intracellular calcium levels. Inwardly rectifying potassium currents were unaffected by adrenergic stimulation. Experiments using the RT-PCR technique demonstrate that lingual epithelium expresses multiple α (α1a, α1b, α1c, α1d, α2a, α2b, α2c) and β (β1, β2) subtypes of adrenergic receptors, and immunocytochemistry localized noradrenaline to a subset of taste receptor cells. Collectively, these data imply strongly that adrenergic transmission within the taste bud may play a paracrine role in taste physiology.  相似文献   
7.
8.
Abstract Traumatic knee dislocations are relatively rare and almost always respond to closed reduction; however, a small percentage of knee dislocations are irreducible and in these cases open reduction is frequently required. A 65-year-old man with an unreduced posterolateral knee dislocation with laterally dislocated patella was seen 3 weeks after a motor vehicle accident. Medial femoral condyle was found buttonholed through the medial capsule together with the medial collateral ligament and lying in the medial joint space that allowed posterior rotary dislocation of the joint. Both cruciate ligaments and medial meniscus were torn. There was no evidence of any vascular or nerve injury. Reduction was accomplished by removal of the capsuloligamentous structures which were incarcerated in the trochlea and intercondylar notch and by excision of meniscal tear. Following posterior cruciate ligament reconstruction with patellar tendon autograft, lateral patellar release, vastus medialis advancement, and gracilis transfer were done.  相似文献   
9.
OBJECTIVE: Hyperventilation and ischaemia increase axonal excitability by changing Na+ conductance in healthy subjects. However, the changes in excitability during and after ischaemia in diabetic patients are less than in healthy controls. This is known as ischaemic resistance. In this study, we investigated the effects of hyperventilation for 20 min on strength-duration time constant (SDTC) of motor axons of the median nerve of diabetic patients with polyneuropathy to determine whether diabetics are less affected by hyperventilation, a form of resistance similar to the ischaemic resistance of diabetics. METHODS: The SDTC of 14 diabetic patients with polyneuropathy and 10 healthy volunteers were measured following stimulation of right median nerve at the wrist prior to and after hyperventilation for 20 min. RESULTS: There was a significant increase in the SDTC in control subjects, but no significant change in the SDTC for patients with diabetic polyneuropathy. The score of the clinical response (paraesthesiae and carpopedal spasm) to hyperventilation of controls was also significantly greater in the controls than the patients. CONCLUSION: Hyperventilation for 20 min has little influence on SDTC in patients with diabetic polyneuropathy. SIGNIFICANCE: The 'resistance' of diabetic nerve is not confined to ischaemia but involves other manoeuvres that can alter axonal excitability.  相似文献   
10.
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