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   20776篇
  免费   1445篇
  国内免费   503篇
耳鼻咽喉   530篇
儿科学   474篇
妇产科学   1220篇
基础医学   503篇
口腔科学   524篇
临床医学   2103篇
内科学   3560篇
皮肤病学   129篇
神经病学   554篇
特种医学   471篇
外国民族医学   2篇
外科学   7085篇
综合类   2143篇
现状与发展   2篇
预防医学   781篇
眼科学   732篇
药学   762篇
  87篇
中国医学   302篇
肿瘤学   760篇
  2024年   53篇
  2023年   458篇
  2022年   680篇
  2021年   1069篇
  2020年   1060篇
  2019年   879篇
  2018年   844篇
  2017年   765篇
  2016年   713篇
  2015年   727篇
  2014年   1361篇
  2013年   1389篇
  2012年   985篇
  2011年   1126篇
  2010年   978篇
  2009年   927篇
  2008年   959篇
  2007年   928篇
  2006年   866篇
  2005年   777篇
  2004年   695篇
  2003年   635篇
  2002年   483篇
  2001年   467篇
  2000年   302篇
  1999年   274篇
  1998年   255篇
  1997年   235篇
  1996年   194篇
  1995年   151篇
  1994年   165篇
  1993年   151篇
  1992年   149篇
  1991年   119篇
  1990年   93篇
  1989年   91篇
  1988年   95篇
  1987年   73篇
  1986年   51篇
  1985年   91篇
  1984年   80篇
  1983年   46篇
  1982年   61篇
  1981年   57篇
  1980年   39篇
  1979年   35篇
  1978年   27篇
  1977年   25篇
  1976年   12篇
  1975年   15篇
排序方式: 共有10000条查询结果,搜索用时 187 毫秒
81.
Objective The aim of this study was to evaluate of adilty of two acute renal failure-specific scoring systenms (the classification by Bellome et al and the AKIN criteria) for predicting hospital mortality after cardiac surgery in adult patients. Methods Between October 1 st 2006 to Decemjber 31 st 2006, 509 adult patients who ungerwent coronary artery bypass grafting (CABG) and/ or valve operation were enrolled in this study. The medical data collection included gender, age, types of operation, perioperative he- modynamic parameters, urine output, biochemical parameters and outcome. Renal function was assessed daily according to the classi- ficatinn by Bellomo and the AKIN criteria, respectively. As references, Acure Physiology and Chronic Health Evaluation(APACHE) Ⅱ and Sepsis-related Organ Failure Assessment (SOFA) score were also calculated. Resuits Three hundred and forty-one patients were male (67.0%), and 168 were female (33.0%), mean age was (56.2±12.0) years old. Tnree hundred and nine patieats un- derwent CABG, 182 underwent valve operation and 18 underwent CABG plus valve operation, Mean duration of ventilation support was (20.4±17.7) houra, and the ICU stay was (1.4±1.0) days. Postoperative hospital stay was (13.8±9.1) days. According to the classification by Bellomo., the highest in-hospital mortality was 52.9% in ARFS group. Mahiplicatinn of in-hospital morality rate was abserved (X2 for trend, P<0.01) in 0.4% (non-ARF), 1.2% (stage 1), 12.0% (stal~ 2) and 32.4% (stage 3) of pa- tients based on the AKIN criteria. By applying the area under the receiver operating characteristic ourve, the classification by Bellomo and the AKIN criteria had good discriminative power. Furthering, multivariate logistic regression analysis verified that the Odds Ratio of the AKIN criteria was 5.478 (P =0.028, 95% Confidence Interval 1.027- 24.856), after adjusting for gender and age. Con- clusion Analytical data confinned good discriminative power of both the AKIN criteria and the classification by Bellomo for predicting hospital mortality of adult postoperative patient with ARF.  相似文献   
82.
腹部手术后并发下肢深静脉血栓16例分析   总被引:1,自引:0,他引:1  
赵占吉  陈晓  毛谡  范筱勇  张军 《腹部外科》2003,16(6):366-367
目的 探讨腹部手术后并发下肢深静脉血栓形成 (DVT)的原因、诊治要点和预防措施。方法 回顾性分析 1 6例腹部手术后并发DVT病人的临床特点及诊断、治疗方法。结果 发生DVT的高危因素是复合创伤、恶性肿瘤、血粘度增高、老年病人、合并高血压病、糖尿病及术后常规应用止血药等。本组 1 6例均治愈 ,无一例发生肺栓塞等严重后果。结论 腹部手术后并发DVT者要积极早期治疗 ,对发生DVT的高危人群术前、术后应采取预防措施  相似文献   
83.
Tonsillectomy is an operation performed by various techniques. We have developed a bipolar diathermy dissection technique that allows a low intra-operative blood loss without an increase in complications. The average blood loss was less than 4 ml in 100 patients. Most were able to drink and eat by 4 and 10 hours respectively. There was no increase in analgesic requirements. No primary haemorrhage was recorded; three patients had a secondary haemorrhage. The technique allows accurate coagulation of blood vessel and is an easy procedure to learn.  相似文献   
84.
A 31–yr male with insulin dependent diabetes mellitus for 20 years underwent general anaesthesia for renal transplantation. During transfer from operating theatre to ICU he developed bradycardia advancing to ventricular fibrillation and had to be resuscitated. Bradycardia did not respond to atropine. Postoperative autonomic nervous function tests showed advanced autonomic neuropathy. He was found to have constantly prolonged QTc interval in his pre– and postoperative ECGs (462–503 ms). Prolongation of QTc interval could be used as a valuable predictor of postoperative cardiac complications in diabetic patients with autonomic neuropathy.  相似文献   
85.
Study Objective: To test the hypothesis that slow administration of local anesthetic into the epidural space by gravity flow reduces the incidence of signs and symptoms of unintended injection.

Design: Prospective, randomized study.

Setting: Teaching hospital.

Patients: 600 ASA physical status I and II parturients scheduled for labor and delivery or elective cesarean section.

Interventions: After identification of the epidural space with pulsations of an air-fluid column, parturients for vaginal delivery (n = 380) were randomized to receive a test dose of 3 ml 3% 2-chloroprocaine with epinephrine 20 μg, two doses of 7 ml bupivacaine 0.03 % with sufentanil 1 μg/ml and epinephrine 2 μg/ml by either gravity flow (Group 1) given over 30 seconds or by bolus injection (Group 2) given over 5 seconds through the epidural needle; parturients for Cesarean delivery (n = 220) were randomized to receive a test dose and two doses of 6 ml lidocaine 2 % with sufentanil 1 μg/ml and epinephrine 2 μg/ml by either gravity flow or by bolus injection through the epidural needle. Changes in maternal heart rate (HR) and blood pressure, signs of intravascular injection, and adverse effects of epidural bupivacaine-sufentanil were recorded after each dose.

Measurements and Main Results: Gravity flow administration (Group 1) was associated with a smaller increase in mean maternal HR (p < 0.001), less hypotension (p < 0.01), sedation (p < 0.01), nausea (p = 0.01), and segmental spread (p < 0.0001) than were corresponding doses given by traditional bolus injection (Group 1) for vaginal or Cesarean deliveries. The incidence of systemic toxicity was zero of 300 (0%) with gravity flow and 4 of 300 (1.3%) by bolus injection, p = 0.12, Fisher's exact test. No patient in either group had an accidental intrathecal injection.

Conclusion: Gravity flow administration of local anesthetic-opioid solution during epidural block for obstetrics was associated with fewer signs of systemic drug absorption and cardiovascular perturbations than was the traditional bolus injection. This study supports the current opinion that slow administration of local anesthetic during epidural black contributes to fewer adverse events.  相似文献   

86.
The effectiveness of fentanyl in attenuating the pressor and heart rate response to orotracheal fibreoptic intubation under general anaesthesia was assessed in 60 healthy patients undergoing elective surgery. Patients were randomly assigned to receive either fibreoptic intubation with or without fentanyl 6 micrograms.kg-1 or traditional Macintosh intubation with fentanyl 6 micrograms.kg-1. A standardised general anaesthetic was administered which included temazepam premedication, thiopentone, atracurium, oxygen, nitrous oxide and isoflurane. The pressor response to fibreoptic intubation was suppressed in those patients who received fentanyl and was similar to that seen in the Macintosh-fentanyl group of patients. The heart rate response to fibreoptic intubation was also significantly reduced in the patients who received fentanyl, but, in contrast, was still significantly greater than that in the Macintosh-fentanyl group. Fentanyl 6 micrograms.kg-1 appears to have a useful place in attenuating the cardiovascular effects of fibreoptic intubation under general anaesthesia.  相似文献   
87.
Difficulties in removing the tracheal tube from the trachea are relatively uncommon. We report here a case of difficult extubation which was precipitated by pulling off the pilot balloon and valve assembly in order to deflate the cuff.  相似文献   
88.
24例骨折术后深部感染的原因及对策   总被引:7,自引:0,他引:7  
目的 探讨骨折术后深部感染的原因、预防和治疗方法。方法 对骨折术后深部感染病灶行扩创后置管闭合灌洗。结果 24例经清创闭合灌洗平均27.5d后,感染均得以控制,效果满意。结论 骨折手术后深部感染原因是多方面的,宜积极预防,早期发现,及时扩创闭合灌洗,遗留肢体功能障碍者留待后期治疗。  相似文献   
89.
Background : The study aimed to assess the relative influence of anaesthesia and muscle relaxation on intubating conditions and the haemodynamic and catecholamine responses to tracheal intubation.
Methods : Sixty ASA 1 or 2 patients were randomly assigned to one of four groups (15 patients each) that differed in the depth of anaesthesia (thiopentone plus fentanyl 2.5 μg kg-1 or thiopentone alone) and the degree of vecuronium–induced neuromuscular block (100% or _>: 65%) at intubation. Muscle relaxation was measured at 0.1 Hz by means of mechanomyography. Heart rate (HR) and mean arterial blood pressure (MAP) were measured before and after induction of anaesthesia, and 1 min and 5 min following intubation, while adrenaline (A) and noradrenaline concentrations (NA) were determined from arterial blood samples.
Results : Intubating conditions were improved primarily by providing complete muscle relaxation at the adductor pollicis muscle (P<0.001) and to a lesser extent by adding fentanyl to thiopentone (P=0.04). The response of HR and MAP to tracheal intubation was attenuated mainly by fentanyl (P<0.001). Complete muscle relaxation further diminished the response of MAP to intubation (P=0.03). Changes in A and NA were dependent on the depth of anaesthesia only (P =>0.01).
Conclusion : The results of the study demonstrate that the sympathoadrenal response to intubation is attenuated by adding fentanyl (2.5 kg-1) to an induction regimen with thiopentone, whereas provision of complete muscle relaxation at the adductor pollicis muscle is necessary to attain smooth intubating conditions.  相似文献   
90.
Purpose To compare the differences in practice and outcome of all radiologically and surgically placed central venous catheters retrospectively over a 2-year period simultaneously, at a single institution. Methods A total of 253 Hickman catheters were inserted in 209 patients; 120 were placed radiologically in 102 patients and 133 were placed surgically in 107 patients. The indication was chemotherapy in 76% of radiological and in 47% of surgical cases; the remainder were for total parenteral nutrition and venous access. Results There were 6 (4.5%) primary surgical failures and a further 17 (13%) surgical cases requiring multiple placement attempts. Pneumothorax occurred once (0.8%) surgically and four times (3.3%) radiologically. There were no radiological primary misplacements but there were five (3.7%) surgical ones. Catheter or central vein thrombosis occurred in four (3.3%) radiological and five (3.7%) surgical cases. The rate of infection per 1000 catheter-days was 1.9 in radiologically placed catheters and 4.0 in surgically placed ones (p<0.001). Average catheter life-span was similar for the two placement methods (100±23 days). Conclusion Radiological placement is consistently more reliable than surgical placement. There are fewer placement complications and fewer catheter infections overall.  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