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   1279015篇
  免费   92842篇
  国内免费   1993篇
耳鼻咽喉   18204篇
儿科学   42359篇
妇产科学   37848篇
基础医学   187329篇
口腔科学   35402篇
临床医学   108303篇
内科学   252079篇
皮肤病学   26536篇
神经病学   99329篇
特种医学   50077篇
外国民族医学   367篇
外科学   197959篇
综合类   26520篇
现状与发展   1篇
一般理论   300篇
预防医学   92764篇
眼科学   29137篇
药学   97888篇
  1篇
中国医学   2496篇
肿瘤学   68951篇
  2018年   11865篇
  2015年   11651篇
  2014年   16051篇
  2013年   24429篇
  2012年   33658篇
  2011年   36087篇
  2010年   21277篇
  2009年   20076篇
  2008年   35082篇
  2007年   38046篇
  2006年   38626篇
  2005年   37911篇
  2004年   36477篇
  2003年   35464篇
  2002年   35018篇
  2001年   58180篇
  2000年   59681篇
  1999年   50766篇
  1998年   14260篇
  1997年   12850篇
  1996年   13092篇
  1995年   12366篇
  1994年   11771篇
  1993年   10880篇
  1992年   41037篇
  1991年   40418篇
  1990年   39923篇
  1989年   38760篇
  1988年   36144篇
  1987年   35381篇
  1986年   33755篇
  1985年   32162篇
  1984年   23945篇
  1983年   20839篇
  1982年   12386篇
  1981年   10944篇
  1980年   10212篇
  1979年   22656篇
  1978年   15887篇
  1977年   13743篇
  1976年   12983篇
  1975年   14209篇
  1974年   16696篇
  1973年   16089篇
  1972年   15328篇
  1971年   14237篇
  1970年   13223篇
  1969年   12743篇
  1968年   11987篇
  1967年   10484篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The authors conducted a clinical and radiographic study on a group of 43 patients with hip arthroprostheses selected from the three-year period from 1984 to 1987, characterized by no immediate postoperative complications, no positional defects on X-ray examination, and with a Renther test greater than 1. Prostheses were cemented, cementless and combined. Scintigraphy was evaluated for areas of subdivision in the proximal end of the femur and acetabulum, making a semi-quantitative comparison of the intensity of captation of each area with that of the skull and sacroiliac synchondrosis. The authors emphasize that this procedure is both reliable and easy for the early determination (pre-clinical and pre-radiographic) of any complications. A scintigraphic examination of the single areas was also capable of revealing the site and entity of prosthetic bone-to-implant interactions. According to the results reported, PCA prostheses seem to be characterized by better biocompatibility.  相似文献   
992.
The activity and principles of administration of Taurolin have been presented. That drug was used in 15 patients with chronic osteitis. Healing by first intention was obtained in 10 patients, necrosis of the skin occurred in 3 patients, recurrence of inflammation was found in one patient in whom accessory sequestroctomy was performed in the last case of osteitis and arteriosclerosis healing was obtained by second intention. The clinical observation of 15 patients has revealed: a) irritating influence of Taurolin on the soft tissue, b) increased phase of secretion of exudate since the 5 day after surgery, c) bactericidal influence of the drug. Sterilization of the focus occurred at 2 to 3 weeks after surgery. The use of Taurolin requires experience, complete abiding by the principles of use of this drug and equipment with a set of Charrier's drains. The authors are carrying on further observation of the use of Taurolin in the treatment of osteitis.  相似文献   
993.
Eighteen renal transplant recipients and sixteen volunteers were subjected to the physiological manoeuvre of head-out water immersion, in order to compare changes in electrolyte and humoral responses known to occur in healthy individuals with those arising as a result of renal denervation in the transplant recipients. Although the tubular sodium response to water immersion was normal, tubular potassium excretion was markedly different in the transplant patients. Plasma values of atrial natriuretic factor increased in both groups and showed a close temporal relationship to urinary excretion of cyclic GMP. The attenuation in transplant recipients of the well-documented suppression of plasma renin activity during water immersion was probably due to a combination of factors, namely lack of renal innervation and an increase in circulating ANF. The small but significant increase in the excretion of enzymically active urinary kallikrein observed only in the transplant recipients during immersion still requires explanation.  相似文献   
994.
Laparoscopic cholecystectomy (LC) using electrocoagulation was successfully performed in 56 out of 58 selected patients. Cholangiography was performed in 53 patients. Six patients had common duct stones; five were unsuspected preoperatively. After the gallbladder was removed, three patients underwent open common duct exploration. In another five cases, anatomical anomalies were discovered. Cholangiography performed via the cystic duct before any structures are divided can prevent the most serious complication--common duct injury. Cholangiography should be attempted on all patients undergoing LC.  相似文献   
995.
A postoperative questionnaire was used in 129 patients who had undergone a wide range of surgical procedures in order to investigate their personal experience of anaesthesia. The most frequent complaints were of feeling cold on waking up, sore throat, vomiting and muscle pains, all of which are capable of reduction by a change in anaesthetic technique. The total number of patients who had one or more complaints was 107 (82.9%). More than a third of the patients were afraid of the anaesthetic, as distinct from the operation. Most had received a pre-operative visit from the anaesthetist which was greatly appreciated. A few patients believed they could have been better informed of possible sequelae. More than 30% were not visited by the surgeon before the operation. A routine postoperative interview, using a preformulated questionnaire, is a good way to assess and maintain a high quality of anaesthesia.  相似文献   
996.
Lifetime anticoagulation has become a therapeutic option for surgical patients with hypercoagulable states or prosthetic arterial bypass grafts. However, physicians may not achieve optimal anticoagulation or may attempt to limit the length of the therapy period because of the perceived morbidity from hemorrhagic complications of Coumadin therapy. A protocol for anticoagulant therapy monitored and regulated by a vascular nurse-clinician was reviewed. Coumadin was prescribed for 1,891 patient-months to 93 patients to maintain their prothrombin time 1.5 to 2 times control (range: 18 to 24 seconds). The mean (+/- SD) prothrombin time for the study population was 19.8 +/- 1.8 seconds. During follow-up, 472 (14%) of 3,479 prothrombin times measured were below the therapeutic range (n = 232) or prolonged (n = 240), prompting an adjustment in the Coumadin dose in 82 (88%) patients. Four patients developed recurrent vascular graft thrombosis while receiving anticoagulation. There were 6 major and 11 minor hemorrhagic complications. Patients with a chronic risk for arterial or venous thrombosis can have out-patient anticoagulant therapy administered at optimal intensity and regulated safely with a low incidence of hemorrhagic and thrombotic events.  相似文献   
997.
A series of branchial arch malformations was induced in 618 embryos from 72 pregnant rats by a single intraperitoneal injection of 10 mg/kg etretinate at 8.5 days of gestation. The litters developed several malformations, including microtia, low set and dorsally placed outer ears, defective middle ear ossicles, short cochleas, defectively differentiated Meckel's cartilages, micrognathia, rudimentary malar bones, lateral facial clefts, fistulas and skin tags, all of which were similar to Treacher Collins' syndrome in man. The defects were accompanied by a pathological differentiation pattern of various isoenzymes in maxillary and mandibular processes. These isoenzymes could be detected in amniotic fluid from the 9th to the 20th days of pregnancy and showed a pathological differentiation pattern here as well. We conclude that a teratogenically induced syndrome affecting the first and second branchial arches is accompanied by a pathological differentiation pattern that can be traced by determinations of isoenzymes in the branchial arches as well as in amniotic fluid.  相似文献   
998.
This study reports our experience in 6 cases of acute idiopathic scrotal oedema. Although children were the primary targets, this pathologic condition was also encountered in adults. Specific diagnosis of acute idiopathic scrotal oedema, opposed to other causes of scrotal swelling, is based on history, an objective examination, velocimetric Doppler exam and echography. Correct diagnosis is important in order to avoid unnecessary surgery. We are inclined to consider acute idiopathic scrotal oedema as an allergic disorder and recommend a follow-up within two days.  相似文献   
999.
The visual acuity, the difference in sensitivity of the two eyes to light (brightness ratio), and contrast sensitivity were assessed in 28 patients with chronic open angle glaucoma and compared with those of 41 normal controls of similar ages and visual acuity. The results obtained were related to the results of Tübingen visual field analysis in patients with glaucoma. Twenty-four of the 28 glaucoma patients (86%) had a significant disparity in brightness ratio between the two eyes. This was found to match the frequency of visual field loss. Moreover, there was a significant relationship between the interocular differences in brightness sense and the difference in the degree of visual field loss between the two eyes. Of the glaucoma patients 39% had sum contrast sensitivities outside the normal range for age-matched normal controls. No significant correlation was found between the interocular difference in brightness sense and the visual acuity or the interocular difference in sum contrast sensitivity. It is concluded that, in the presence of a normal visual acuity, the brightness ratio test warrants evaluation as a potential screening test for chronic open angle glaucoma.  相似文献   
1000.
Despite the progress achieved in the treatment of ocular diseases, removal of the eyeball still has to be resorted to rather often. The records of 12 hospitals of Moscow over a year evidence 678 enucleations and eviscerations, 248 (39 percent) of these for oncologic diseases, 189 (29.1 percent) because of injury aftereffects, 153 (24 percent) because of glaucoma, and 58 (8 percent) because of ocular inflammations. Common enucleation was carried out in 203 of +/- 400 patients (except oncologic ones) and enucleation with implantation of biological and synthetic drafts in 197 cases, i.e. in half of the patients who needed it; this is explained by the absence of the necessary implants in hospitals. A bank of grafts should be created for centralized provision of ocular hospitals.  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