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   77098篇
  免费   5287篇
  国内免费   1639篇
耳鼻咽喉   3106篇
儿科学   911篇
妇产科学   1543篇
基础医学   1976篇
口腔科学   3143篇
临床医学   7162篇
内科学   7410篇
皮肤病学   706篇
神经病学   2579篇
特种医学   1258篇
外国民族医学   21篇
外科学   26713篇
综合类   10274篇
现状与发展   6篇
一般理论   2篇
预防医学   2782篇
眼科学   4668篇
药学   3035篇
  175篇
中国医学   850篇
肿瘤学   5704篇
  2024年   266篇
  2023年   2086篇
  2022年   3196篇
  2021年   4203篇
  2020年   4159篇
  2019年   3563篇
  2018年   3396篇
  2017年   2939篇
  2016年   2926篇
  2015年   2976篇
  2014年   5841篇
  2013年   5456篇
  2012年   4379篇
  2011年   4605篇
  2010年   3639篇
  2009年   3473篇
  2008年   3320篇
  2007年   3302篇
  2006年   2885篇
  2005年   2529篇
  2004年   2188篇
  2003年   1759篇
  2002年   1386篇
  2001年   1320篇
  2000年   1138篇
  1999年   1041篇
  1998年   856篇
  1997年   813篇
  1996年   608篇
  1995年   498篇
  1994年   436篇
  1993年   355篇
  1992年   298篇
  1991年   297篇
  1990年   204篇
  1989年   198篇
  1988年   196篇
  1987年   200篇
  1986年   156篇
  1985年   177篇
  1984年   161篇
  1983年   106篇
  1982年   114篇
  1981年   98篇
  1980年   82篇
  1979年   47篇
  1978年   36篇
  1977年   35篇
  1976年   26篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Summary The width of the third ventricle, the length of the anterior commissure-posterior commissure line (AC-PC line), the spatial position of the midplane of the third ventricle, and the co-ordinates of the AC, the PC, and of 17 brain targets in the thalamus, hypothalamus and pallidum, were assessed on a pre-operative Stereotactic computed-tomography (CT) study and compared to measurements on intra-operative air-ventriculography, using a non-invasive relocatable Stereotactic frame.There were no significant differences in the length of the ACPC line, in the position of the midsagittal plane of the third ventricle, or in the vertical or lateral co-ordinates of the AC, the PC and the cerebral targets, between measurements on CT and on air-ventriculography. However, the width of the third ventricle was significantly larger, and the spatial positions of both AC and PC were significantly more anterior on air-ventriculography than on the CT study. This anterior dislocation of the commissures was presumably due to the insufflation of air into the ventricles of patients being in the supine position during surgery.  相似文献   
102.
103.
Between November 1967 and December 1994, 242 patients with gestational trophoblastic disease (GTD) were treated with chemotherapy by the Gynecology Service of Memorial Hospital. Eighty-seven of the patients (35.9%) underwent at least one major operation during the course of their illness. Twenty-six patients underwent two major operations, and in five patients, three major operations were performed, for a total of 118 procedures. The most frequent procedures were: hysterectomy, 56 (47.4%); hysterotomy, 15 (12.7%); thoracotomy, 13 (11%); and craniotomy, 5 (4.2%). Twenty-nine additional procedures ranging in complexity from oophorectomy to segmental liver resection were also performed. Twenty-nine operations (24.5%) were considered to be beyond the scope of most gynecologic surgeons. The overall complete remission rate for 242 patients was 90.4%. The rate for patients who underwent a major surgical procedure was 79.3% compared to 96.7% for patients whose treatment was with chemotherapy alone.
The data demonstrate that the integration of surgery in the management of GTD patients often requires a multidisciplinary approach that in many cases can best be achieved at specialized treatment centers.  相似文献   
104.
Day care is generally accepted in anterior segment eye-surgery. In the Rotterdam Eye Hospital this option was also considered for posterior segment surgery. We were interested in the opinion, of patients on this matter and therefore asked patients, who were admitted for posterior segment eye-surgery, to answer a questionnaire. The major question was: ‘If your physician had given his permission, do you think it would have been possible for you to go home on the evening after surgery?’. Other questions evaluated problems in organising assistance at home and transportation to the out-patient clinic as well as circumstances after the operation, such as pain, nausea, dizziness and anxiety. Eighty-one out of 87 patients responded: 56% answered ‘eyes’ and 44% ‘no’ to the major question. Relating the answer to the major question to medical data and to answers to the other questions, we found organizational problems at home and anxiety to have a statistical significant relation with a negative answer. Clinical factors like age, American Society of Anesthesiologists (ASA)-class, diabetes mellitus (including insulin-dependant), type of anesthesia, time of the day the surgery was finished, duration of surgery, pain, nausea or dizziness were not signficantly related. The number of patients involved in this study, however, is too small to draw conclusions on specific subgroups of patients.  相似文献   
105.
A comprehensive neuropsychological test battery was administered to 10 consecutive patients undergoing neurosurgical intervention, capsulotomy, as a last resort treatment for chronic, incapacitating, and otherwise intractable illness, either obsessive-compulsive disorder (OCD; n= 5) or non-OCD anxiety disorder (n= 5). The aim was to study the neuropsychology of severe anxiety disorders before and after a defined neurosurgical intersection of connections between the frontal lobes and related brain regions. Although extremely disabled by their illness before surgery, the patients performed within the normal range on most tests. After capsulotomy, there was significant improvement on measures of clinical morbidity and of psychosocial functioning, and the general neuropsychological performance remained remarkably intact. In a subgroup of 5 patients, however, perseverative responses were more common postoperatively, possibly indicating dysfunction of systems involving the frontal lobes. Although admittedly sparse, these data can be interpreted as suggesting that in vulnerable individuals, capsulotomy may give rise to increased perseverative behaviour in the laboratory, and possibly in the real world as well. This risk must be weighed against the potential clinical benefit of capsulotomy in this extremely disabled, sometimes suicidal patient population.  相似文献   
106.
This study compares the incidence of local tumor recurrence following primary excision with the CO2 laser, Nd:YAG laser (contact), Argon Beam Coagulator, or electrocautery. One hundred eight Fisher 344 rats with R3230AC mammary tumors (1.6 +/- 0.04 [SD] cm diameter) were used. All animals were randomized into groups of similar tumor size. In groups C and CS, excision was performed with a Sharplan 1060 CO2 laser (TEMoo, 25 W, continuous wave [CW], 0.2-mm spot size). Wounds in group CS were "sterilized" (0.5-mm spot size, 25 W, CW) by gently heating the wound without causing blanching or charring. In group N, a 0.4-mm contact Laser Blade and a Cooper 8000 Nd:YAG laser at 20 W CW was used. In groups SA1 and SA2, tumors were excised with the scalpel, and hemostasis and wound "sterilization" were accomplished with the Bard System 6000 Argon Beam Coagulator (ABC) at 40 W and 4 liters/min argon gas flow in SA1 and 12 liters/min in SA2. In group E, excision was accomplished at 40 W blend mode, 10 W spray mode. In group EA, excision was accomplished at 60 W cutting current, and hemostasis was achieved with the ABC. The animals were examined for evidence of recurrence for 34 days postoperatively. Mortalities were excluded from analysis. The incidence of recurrence was 11/14 (79%) in C, 6/16 (38%) in CS, 10/14 (71%) in SA1, 6/13 (46%) in SA2, 6/15 (40%) in N, 7/10 (70%) in EA, and 3/15 (20%) in E. Group E is statistically different (P less than .01) from groups EA, C, and SA1. Group C was different (P less than .01) from groups E, CS, and N. These results demonstrate an inverse relationship between tumor recurrence and local thermal effects at the surgical site. The ABC did not increase tumor recurrence. Contact YAG surgery was similar to CO2 laser excision and "sterilization." An attempt to study the influence of gas flow and pressure on local tumor recurrence and metastases should be made.  相似文献   
107.
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   
108.
We reviewed the records of 110 consecutive patients with advanced-stage epithelial ovarian carcinoma treated at the Soroka Medical Center, Beer-Sheva, Israel, from 1961-1987. Twenty patients (18.1%) had optimal debulking at initial laparotomy, 30 patients (27.2%) had nonoptimal debulking at initial laparotomy, 20 patients (18.1%) had an "inoperable" disease at initial laparotomy, and 40 patients (36.3%) had such poorly written records that no information about the degree of resectability at initial laparotomy could be obtained. Four patients, in whom the residual tumor left at initial laparotomy had responded to chemotherapy, had a second laparotomy. In all four patients optimal debulking surgery at second laparotomy was easy to perform and was successful. The value of a second laparotomy after a few cycles of chemotherapy in order to optimally debulk the residual tumor left at initial laparotomy is discussed. It is concluded that a second attempt of debulking surgery after chemotherapy has a respectable place in the management of patients with advanced-state epithelial ovarian carcinoma, but further research is needed.  相似文献   
109.
This surgical anatomy study aimed to evaluate the possibility of identifying the external laryngeal nerve during thyroid surgery and the possible variations of nerves at risk. Fifty patients underwent total thyroidectomies during a period of 12 months. Using a neurostimulator, the distal motor branch of the external laryngeal nerve was searched. Electrical stimulation of a nervous branch aimed to provoke a global contraction of the cricothyroid in order to identify with certitude the external laryngeal nerve. The external laryngeal nerve was identified in 20% of cases. Its course was, with almost equal frequency, either (1) between the vessels of the superior thyroid pedicle or (2) superficial and anterior to the fascia of the cricothyroid muscle. The external laryngeal nerve is hard to find during thyroid surgery, even with a neurostimulator. It can be vulnerable during thyroid surgery but only in cases of anatomic variations. Searching for the nerve systematically during thyroid surgery does not seem to be useful. Several precautions when dissecting the superior pole of the thyroid gland seem to be necessary and sufficient to respect the external laryngeal nerve.  相似文献   
110.
Objective and design: Cardiopulmonary bypass (CPB) impairs monocyte and neutrophil proliferation, cytokine synthesis, and antigen presentation. This study compares in vivo data with results from an extracorporeal circulation (ECC) model, distinguishing direct effects on cytokine synthesis from regulatory mechanisms. Patients and methods: Whole blood from 18 patients prior to, during and after CPB was stimulated with lipopolysaccharide (LPS). Tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-8 levels were measured. Additionally, blood from 4 volunteers was circulated in an ECC model. Cytokine levels were measured before and during mock ECC. Results: LPS-induced cytokine synthesis was reduced after CPB (TNF-α: 11 %; IL-6: 29 %; IL-8: 48 % of preoperative values, all p < 0.001). In mock ECC, cytokine production (except IL-8) was suppressed: TNF-α production was lowest 60 min after starting ECC, IL-6 synthesis was lowest at 90 min (33 % and 15 % vs. pre-ECC levels; both p < 0.001). Patient sera contained cytokine-inhibitory activity after CPB, an activity not found in mock ECC. Conclusions: (1) In patients, CPB induces early transient LPS hyporesponsiveness; (2) blood contact with foreign surfaces induces LPS hyporesponsiveness; (3) serum cytokineinhibitory activities are released after CPB, but not in mock ECC. Impaired leukocyte function may explain increased susceptibility to infections after CPB. Received 16 September 2006; accepted without revision by K. Visvanathan 18 October 2006  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