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   4822篇
  免费   202篇
  国内免费   109篇
耳鼻咽喉   6篇
儿科学   52篇
妇产科学   117篇
基础医学   100篇
口腔科学   3篇
临床医学   622篇
内科学   114篇
皮肤病学   5篇
神经病学   197篇
特种医学   123篇
外科学   1873篇
综合类   1218篇
现状与发展   1篇
预防医学   155篇
眼科学   16篇
药学   386篇
  5篇
中国医学   63篇
肿瘤学   77篇
  2024年   4篇
  2023年   42篇
  2022年   85篇
  2021年   118篇
  2020年   105篇
  2019年   93篇
  2018年   75篇
  2017年   111篇
  2016年   114篇
  2015年   99篇
  2014年   236篇
  2013年   235篇
  2012年   233篇
  2011年   269篇
  2010年   216篇
  2009年   207篇
  2008年   223篇
  2007年   275篇
  2006年   250篇
  2005年   238篇
  2004年   191篇
  2003年   189篇
  2002年   177篇
  2001年   158篇
  2000年   127篇
  1999年   102篇
  1998年   94篇
  1997年   69篇
  1996年   70篇
  1995年   58篇
  1994年   73篇
  1993年   76篇
  1992年   47篇
  1991年   53篇
  1990年   55篇
  1989年   54篇
  1988年   56篇
  1987年   47篇
  1986年   32篇
  1985年   37篇
  1984年   24篇
  1983年   23篇
  1982年   26篇
  1981年   17篇
  1980年   21篇
  1979年   12篇
  1978年   6篇
  1977年   7篇
  1974年   1篇
  1972年   1篇
排序方式: 共有5133条查询结果,搜索用时 15 毫秒
31.
目的探讨硬膜外腔注射生理盐水对剖宫产术患者腰麻效果的影响。方法择期行子宫下段剖宫产术患者60例,年龄24~30岁,体重59~73 kg,随机分为2组,每组30例,A组蛛网膜下腔注射规定剂量的0.75%布比卡因后硬膜外腔注射生理盐水5 ml;B组蛛网膜下腔注射0.75%布比卡因。按序贯法进行试验,设定布比卡因的起始剂量为9 mg,剂量梯度为1.5 mg,若上一例有效,则下一例递减一个剂量梯度,若无效则下一例递增一个剂量梯度,蛛网膜下腔阻滞有效的标准为注射布比卡因后20 min内阻滞上平面达T5。采用概率单位法计算ED50。结果A组布比卡因的ED50(5.8 mg)低于B组(8.1 mg),两组比值为0.72,95%置信区间为0.27~0.98,区间范围不包括1,差异有统计学意义(P〈0.05)。结论硬膜外腔注射生理盐水可增强剖宫产术患者腰麻的效果。  相似文献   
32.
33.
The relationship between the age and the spread of analgesia from different epidural anesthetic doses was examined by studying analgesic dose responses in cervical epidural analgesia. Two different anesthetic doses (5ml or 10ml) of 2% mepivacaine were injected into the cervical epidural space at a constant pressure (80mmHg) using an intravenous apparatus, and the spread of analgesia to pinprick was assessed. The significant correlation was found between the patients age and the number of spinal segments blocked (5ml:r = 0.8498, P < 0.01, 10ml:r = 0.5988, P < 0.01). The inverse linear relationship was found between the patients age and the segmental dose requirement (5ml:r = –0.6754, P < 0.01, 10ml:r = –0.5784, P < 0.01). Patients under 39 years of age showed a direct relationship between the dose injected and the number of spinal segments blocked, enabling prediction of the number of segments blocked with a given dose of local anesthetic. Doubling the epidural dose approximately doubled the number of spinal segments blocked. The analgesic dose-response relation in patients over 60 years of age differed from that in patients under 39 years of age and doubling the epidural dose did not double the number of spinal segments blocked. Progressively more extensive analgesia was obtained from a given dose of local anesthetic with advancing age. It was difficult to limit the extent of analgesia by injecting a smaller dose of local anaesthetic in the elderly.(Hirabayashi Y, Matsuda I, Inoue S et al.: Analgesic dose-response relation in cervical epidural block. J Anesth 2: 22–27, 1988)  相似文献   
34.
A comparison was made of the effects of continuous epidural analgesia with bupivacaine and intermittent epidural morphine on bowel function after abdominal hysterectomy. The duration of postoperative ileus was assessed as the time from the end of operation to the first postoperative passage of flatus and feces. Twenty-two patients were randomly allocated to two equal groups. An "epidural morphine" group received general anesthesia and epidural morphine for postoperative pain relief, and an "epidural bupivacaine" group was given combined general anesthesia and epidural anesthesia with 0.5% bupivacaine intraoperatively and epidural analgesia with 0.25% bupivacaine postoperatively. Epidural morphine or bupivacaine was given for 42 h postoperatively. Pain intensity (visual analog scale) was low in both groups, but lower (P less than 0.05) in the epidural bupivacaine group. The time to first passage of flatus was 22 +/- 16 h in the epidural bupivacaine group and 56 +/- 22 h in the epidural morphine group (P less than 0.001). The time to first postoperative passage of feces was shorter (P less than 0.05) in the former than in the latter 57 +/- 44 h vs 92 +/- 22 h). The patients of the epidural bupivacaine group started intake of oral fluids earlier (P less than 0.01) and to a greater extent (P less than 0.05) than those in the epidural morphine group. It is concluded that the duration of postoperative ileus after hysterectomy is shorter when epidural bupivacaine is given for postoperative pain relief than when this is achieved by epidural morphine.  相似文献   
35.
A 23-year-old primigravid patient who received epidural analgesia for pain of labour presented with persistent, apparently irremediable, unilateral analgesia. Computerized axial tomo-epidurography demonstrated absence of circumferential spread due to lateral placement of the catheter. Transforaminal escape of contrast medium into the paravertebral area had occurred and anterior and posterior midline partitioning of the epidural space was obvious. All the usual measures to promote contralateral analgesia, except re-insertion of the catheter, had been tried without success.  相似文献   
36.
To determine the value of the usually given urgent palliative radiotherapy in paraplegic patients with epidural compression from metastatic tumor, 20 consecutive cases treated between 1981 and 1986 were retrospectively analyzed. Bronchogenic and prostatic carcinoma were the more common extraspinal sources of metastasis. Epidural metastasis involved the thoracic spine in most cases. The onset of neurological symptomatology was frequently within two weeks prior to hospitalization. The majority of the subjects received at least 3000 cGy given in 10 to 15 fractions. Symptomatic (pain relief) response rate was 78 (7/9) percent. The observed period of survival averaged 2.5 months after treatment. This study reaffirmed the little chance for recovery of lost limb(s) motor function. None of the patients (most of whom were paraplegic from two to 90 days pre-irradiation) became ambulatory including the two in whom irradiation was administered within 24 hours from the onset of paraplegia.  相似文献   
37.
(1) The spread of epidural analgesia following injection of 15ml of 2% mepivacaine was 17.3 ± 0.6, 14.3 ± 0.4, and 13.3 ± 0.7 spinal segments in cervical, thoracic, and lumbar epidural analgesia, respectively. The patients age showed significant correlation with the spread of epidural analgesia in cervical (r = 0.5776, p < 0.001), thoracic (r = 0.3758, p < 0.01), and lumbar area (r = 0.8195, p < 0.001). The spread of cervical epidural analgesia was more caudad than cephalad (p < 0.05), but in lumbar epidural analgesia it was more cephalad than caudad (p < 0.05). There was no difference between the cephalad and caudad spread in thoracic epidural analgesia.(2) The epidural pressure immediately after injection of 15ml of 2% mepivacaine into the lumbar epidural space at a constant pressure (80mmHg) correlated to the patients age (r = –0.5714, p < 0.001) and the spread of analgesia (r = –0.3904, p < 0.05). The lower epidural pressure associated with higher age, the wider spread of analgesia. There was no significant correlation between the residual pressure at 60 seconds and the age or the spread of analgesia.(Hirabayashi Y et al.: Spread of epidural analgesia following a constant pressure injection: an investigation of relationships between locus of injection, epidural pressure and spread of analgesia. J Anesth 1: 44–50, 1987)  相似文献   
38.
The relationships between the epidural pressures following the injection of local anesthetic solution and the spread of epidural analgesia were investigated. In 46 patients, 15ml of 2% mepivacaine was injected into the lumbar epidural space at a constant rate (1ml/sec) using an electropowered syringe pump. Injection pressures and residual pressures were recorded and the spread of analgesia to pinprick was assessed. The changes of the epidural pressures during and following the injection of a volume of local anesthetic solution in old subjects were significantly smaller than those in young subjects (P < 0.05). The spread of analgesia closely correlated with the epidural pressures during and following the injection of local anesthetic solution. The most close correlation was found between the epidural pressure immediately after the completion of injection and the spread of analgesia (r = –0.5659, P < 0.001). In conclusion, the lower the terminal injection pressure and the residual pressures associated with higher age, the wider the spread of epidural analgesia.(Hirabayashi Y, Matsuda I, Inoue S et al.: Epidural pressure and its relation to spread of epidural analgesia. J Anesth 1: 168–172, 1987)  相似文献   
39.
马赞 《中国校医》2022,36(3):200
目的 探讨腰硬联合麻醉(CSEA)与全麻对老年腹部手术患者术后认知功能的影响。方法 选取本院2018年5月—2019年5月收治的82例老年腹部手术患者,按随机数表法分为观察组和对照组,各41例。观察组应用CSEA,对照组则采用全身麻醉。比较两组的麻醉相关指标,术后6 h、12 h、24 h的精神功能状态以及患者术后短期认知功能障碍的发生率。结果 观察组麻醉起效时间(min)、完全清醒时间(min)分别为(8.19±1.04)、(28.67±5.60)与对照组的(10.17±2.12)、(37.25±6.12)比较差异有统计学意义(P<0.05);观察组视觉模拟评分(VAS)(3.51±1.12)与对照组的(4.27±1.15)比较差异有统计学意义(P<0.05);观察组患者术后6 h、12 h、24 h时的MMSE评分分别为(22.27±1.46)、(26.23±1.26)、(28.19±1.24),均高于对照组的(21.46±1.35)、(24.68±1.23)、(26.37±1.19)(P<0.05);观察组短期内POCD的发生率为4.88%,低于对照组的24.39%,差异有统计学意义(P<0.05)。结论 对老年腹部手术患者采用CSEA,不仅能缩短麻醉起效时间和完全清醒的时间,减轻疼痛,而且对患者精神功能的影响小,可有效减少短期内认知功能障碍发生率。  相似文献   
40.
国产盐酸氯普鲁卡因临床效应分析   总被引:6,自引:0,他引:6  
目的 分析研究国产盐酸氯普卡因冻干粉与针剂分别应用于硬膜外麻醉、臂丛神经阻滞、局部浸润麻醉的效果。方法 采用随机双盲目的方法分组进行研究。硬膜外麻醉45例,分为3组(每组15例):Ⅰ组1.7%利多卡因,Ⅱ组氯普鲁卡因粉剂稀释为3%,Ⅲ组3%氯普鲁卡因针剂;臂丛神经阻滞40例,分为4组(每组10例);I组1.33%利多卡因,Ⅱ组2%普鲁卡因,Ⅲ组氯普鲁卡因粉剂稀释为2%,Ⅳ组2%氯普鲁卡因针刺;局部浸润麻醉30例(每例10例)分为3组:Ⅰ组1%普鲁卡因,Ⅱ组氯普鲁卡因粉剂稀释为1%,Ⅲ组1%氯普鲁卡因针剂。结果 硬膜外组中除Ⅲ组运动消失时间明显短于Ⅰ组外(P<0.05),其余指标无明显统计学差异;臂全神经阻滞组中,实验组疼痛恢复及运动恢复时间少于对照组I组,有统计学差异(P<0.01),实验组Ⅲ组疼痛及运动恢复时间均比对照组Ⅱ组长(P<0.05);局部浸润麻醉组中两实验组疼痛消失迅速,疼痛恢复时间均长于对照组,Ⅲ组短于Ⅱ组。结论 国产盐酸氯普鲁卡因麻醉起效迅速,性能稳定,粉剂比针剂更佳;作用维持时间介于盐酸普鲁卡因与利多卡因之间。  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