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   165397篇
  免费   6573篇
  国内免费   386篇
耳鼻咽喉   2206篇
儿科学   4845篇
妇产科学   3812篇
基础医学   23596篇
口腔科学   5402篇
临床医学   9580篇
内科学   36601篇
皮肤病学   4512篇
神经病学   13346篇
特种医学   4275篇
外国民族医学   1篇
外科学   19056篇
综合类   812篇
一般理论   26篇
预防医学   19718篇
眼科学   4355篇
药学   12849篇
中国医学   665篇
肿瘤学   6699篇
  2023年   867篇
  2021年   2454篇
  2020年   1452篇
  2019年   2821篇
  2018年   5038篇
  2017年   3147篇
  2016年   3131篇
  2015年   3471篇
  2014年   3818篇
  2013年   5842篇
  2012年   10076篇
  2011年   10650篇
  2010年   5297篇
  2009年   3882篇
  2008年   8729篇
  2007年   9379篇
  2006年   8996篇
  2005年   8601篇
  2004年   7958篇
  2003年   7464篇
  2002年   7097篇
  2001年   4906篇
  2000年   5465篇
  1999年   4168篇
  1998年   787篇
  1992年   2252篇
  1991年   2016篇
  1990年   2012篇
  1989年   1739篇
  1988年   1649篇
  1987年   1536篇
  1986年   1566篇
  1985年   1472篇
  1984年   1056篇
  1983年   906篇
  1979年   1213篇
  1978年   814篇
  1977年   789篇
  1976年   753篇
  1975年   883篇
  1974年   1123篇
  1973年   1168篇
  1972年   1111篇
  1971年   1084篇
  1970年   1007篇
  1969年   1083篇
  1968年   1107篇
  1967年   977篇
  1966年   880篇
  1965年   549篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
To obtain a new model of chronic portal hypertension in the rat, two classical methods to produce portal hypertension, partial portal vein ligation and the oral administration of thioacetamide (TAA), have been combined. Male Wistar rats were divided into four groups: 1 (control; n?=?10), 2 [triple partial portal vein ligation (TPVL); n?=?9], 3 (TAA; n?=?11), and 4 (TPVL plus TAA; n?=?9). After 3 months, portal pressure, types of portosystemic collateral circulation, laboratory hepatic function tests (aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase) and liver histology were studied. The animals belonging to group 2 (TPVL) developed extrahepatic portosystemic collateral circulation, associated with mesenteric venous vasculopathy without hepatic destructurization or portal hypertension. Animals from group 3 (TAA) developed cirrhosis and portal hypertension but not extrahepatic portosystemic collateral circulation, or mesenteric venous vasculopathy. Finally, the animals from group 4 (TPVL?+?TAA) developed cirrhosis, portal hypertension, portosystemic collateral circulation, and mesenteric venous vasculopathy. The association of TPVL and TAA can be used to obtain a model of chronic portal hypertension in the rat that includes all the alterations that patients with hepatic cirrhosis usually have. This could, therefore, prove to be a useful tool to study the pathophysiological mechanisms involved in these alterations.  相似文献   
52.
53.
PURPOSE: Temporomandibular joint (TMJ) arthroscopy has been considered a safe surgical procedure in the treatment of TMJ derangement. However, it is not exempt from complications. This study evaluates the complications of arthroscopy in patients with internal derangement of TMJ. PATIENTS AND METHODS: Five hundred consecutive patients (670 joints) with TMJ derangement who underwent arthroscopy between 1995 and 2004 were retrospectively analyzed. All the patients were classified as II to V in the Wilkes classification. Lysis and lavage, electrocautery of the posterior ligament, injection of corticoids, injection of ethanolamine, myotomy of lateral pterygoid muscle attachments, myotomy and electrocautery, motor debridement, injection of sodium hyaluronate, and meniscal suture were performed in different patients. RESULTS: Complications were recognized during or immediately after the surgery. They were observed in 5 of 341 (1.26%) arthroscopies of the right TMJ and 4 of 329 (1.21%) arthroscopies of the left TMJ. A 1.34% complication rate was found in the whole series. No blood clots within the external auditory canal were observed. Bleeding within the superior TMJ space was observed in 57 cases (8.5%), 36 of them in the right TMJ and 21 in the left TMJ, but they were not considered as true complications. Lacerations of the external auditory canal were found in 2 cases (0.3%), with no cases of perforation of the tympanic membrane. Lesion of the auriculotemporal nerve was observed in a case. Paresia of the facial nerve was found in 4 cases (0.6%). Alteration of visual accuracy of the ipsilateral eye was also observed in a patient immediately after the surgery. CONCLUSION: Special care must be taken to reduce complications within the upper joint space by means of an adequate instrumentation and by paying attention to essential points of the arthroscopic technique.  相似文献   
54.
This report summarizes and analyzes the responses of various organizations that provided assistance to the National Oncology Institute (Instituto Oncológico Nacional, ION) of Panama following the overexposure of 28 radiation therapy patients at the ION in late 2000 and early 2001. The report also looks at the long-term measures that were adopted at the ION in response to the overexposure incident, as well as implications that the incident has for other cancer treatment centers worldwide. In March 2001, the director of the ION was notified of serious overreactions in patients undergoing radiation therapy for cancer treatment. Of the 478 patients treated for pelvic cancers between August 2000 and March 2001, 3 of them had died, possibly from an overdose of radiation. In response, the Government of Panama invited international experts to carry out a full investigation of the situation. Medical physicists from the Pan American Health Organization (PAHO) were among those invited. They ascertained that 56 patients treated with partially blocked teletherapy fields for cancers of the uterine cervix, endometrium, prostate, or rectum, had had their treatment times calculated using a computerized treatment planning system. PAHO's medical physicists calculated the absorbed doses received by the patients and found that, of these 56 patients, only 11 had been treated with acceptable errors of +/-5%. The doses received by 28 of the 56 patients had errors ranging from +10 to +105%. These are the patients identified by ION physicists as overexposed. Twenty-three of the 28 overexposed patients had died by September 2005, with at least 18 of the deaths being from radiation effects, mostly rectal complications. The clinical, psychological, and legal consequences of the overexposures crippled cancer treatments in Panama and prompted PAHO to assess radiation oncology practices in the countries of Latin American and the Caribbean. ION clinicians evaluated the outcome of 125 non-overexposed patients who had been treated in the same time period and for the same cancer sites as the overexposed patients. The clinicians uncovered a larger recurrence of cervical cancers than expected. The finding prompted PAHO to launch an initiative for the accreditation of radiation oncology centers in Latin America and the Caribbean, working in collaboration with professional societies for radiation oncologists, medical physicists, and radiotherapy technologists. The Latin American Association for Radiation Oncology (Asociación Latinoamericana de Terapia Radiante Oncológica) has established an accreditation commission. Accreditation will require that centers implement a comprehensive radiation oncology quality assurance program that follows international guidelines. Statistical data on patient outcomes will be collected in order to document needs in radiotherapy centers in Latin America and the Caribbean and to define future strategies for cancer treatment.  相似文献   
55.
This study presents the case of a patient with necrobiosis or necrosing fascitis of the inguinal region, secondary to a complicated Amyand’s hernia with a concomitant ipsilateral Richter’s hernia. The patient was treated with open trans-abdominal surgery and hernia repair through the pre-peritoneal approach, plus anti-microbians, and thrice-daily wound cleansing and dressings to the inguinal region. Evolution was satisfactory. There are no reports in the literature of a case such as this.  相似文献   
56.
57.
J Czigány 《Orvosi hetilap》1989,130(4):177-181
The tele-thermographic examinations are of non-invasive character, they can be repeated any time and may be applied also for check-up examinations. The fact that they are evaluated together with other completing clinical examinations (X-ray, scintigraphy, ultrasonography, biopsy etc.) gives the objective significance and value of the examination. According to the author's observation the tele-thermography provides important help in the diagnostics of cervico-facial tumors, in the demonstration of metastases before the operation and detection of postoperative recurrences, in the follow-up of the patient's condition at the period of irradiation- or cytostatic therapy gives exact information in dermatology on the biological activity and extent of malignant melanoma. The treatment of persons with burn- or frostbite injuries requires it equally and good information may be obtained by its use on the condition of blood circulation in cases of vascular obstruction and vascular anomalies.  相似文献   
58.
59.
The purpose of this study is to determine the importance of two-dimensional echocardiography performed soon after admission to the coronary care unit to provide useful information concerning wall-motion abnormalities, and to detect and characterize left ventricular thrombi. A major goal is to identify a subgroup of patients with acute myocardial infarction who are at risk for systemic embolization; in this subgroup the benefits of anticoagulation treatment would theoretically outweigh the associated risks. We studied 7 consecutive male patients, age range from 32 to 60 years, with acute myocardial infarction. Five patients had antero-septal infarction, 1 anterolateral and another had anterior wall infarction. We performed two-dimensional echocardiography within the first week after admission. All patients had severe apical-wall-motion abnormalities (akinesis or dyskinesis) and left ventricular thrombi. All patients received anticoagulation therapy. Two-dimensional echocardiography, performed one month after the first study, showed that the thrombi had decreased in size in 6 patients and could not be visualized in 1 patient. The noninvasive nature of echocardiography allows serial evaluations of patients with known left ventricular thrombi and permits assessment of the effect of therapy.  相似文献   
60.
We present a case report of a patient suffering from portal and superior mesenteric vein thrombosis secondary to splenectomy. No surgical procedure could be performed due to the extension of thrombus.Local fibrinolysis treatment with urokinase through a percutaneous transhepatic approach was decided upon, and this procedure had a successful patient outcome.  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