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   65483篇
  免费   5581篇
  国内免费   141篇
耳鼻咽喉   942篇
儿科学   1722篇
妇产科学   1629篇
基础医学   8983篇
口腔科学   1481篇
临床医学   7649篇
内科学   12367篇
皮肤病学   1058篇
神经病学   5416篇
特种医学   2702篇
外国民族医学   1篇
外科学   8895篇
综合类   1075篇
现状与发展   1篇
一般理论   38篇
预防医学   6920篇
眼科学   1581篇
药学   4729篇
  2篇
中国医学   79篇
肿瘤学   3935篇
  2022年   467篇
  2021年   1086篇
  2020年   618篇
  2019年   1033篇
  2018年   1250篇
  2017年   972篇
  2016年   1009篇
  2015年   1143篇
  2014年   1592篇
  2013年   2376篇
  2012年   3459篇
  2011年   3608篇
  2010年   1944篇
  2009年   1709篇
  2008年   3028篇
  2007年   3287篇
  2006年   3232篇
  2005年   3203篇
  2004年   3044篇
  2003年   2730篇
  2002年   2628篇
  2001年   1754篇
  2000年   1838篇
  1999年   1614篇
  1998年   846篇
  1997年   645篇
  1996年   631篇
  1995年   645篇
  1994年   549篇
  1993年   536篇
  1992年   1348篇
  1991年   1237篇
  1990年   1198篇
  1989年   1133篇
  1988年   1041篇
  1987年   1053篇
  1986年   972篇
  1985年   974篇
  1984年   792篇
  1983年   680篇
  1982年   519篇
  1981年   481篇
  1980年   469篇
  1979年   712篇
  1978年   569篇
  1977年   470篇
  1974年   480篇
  1973年   458篇
  1972年   478篇
  1971年   437篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Proximal upper extremity (subclavian and axillary) vascular injury (SAVI) and brachial plexus injury (BPI) occur uncommonly. However, BPI may be associated with SAVI and frequently is an important determinant of long-term disability. The medical records of patients with traumatic SAVI, BPI, or both over a 5-year period were reviewed. A total of 31 patients were identified. The group was predominantly male (28 men/3 women) with a mean age of 30.5 +/- 1.8 years (range, 15-63 years). Blunt trauma accounted for 43.5% of SAVI cases and 77.8% of BPI cases. Thirteen patients (41.9%) sustained SAVI alone (group I), 10 patients (32.2%) had combined SAVI and BPI (group II), and 8 patients (25.9%) had BPI alone (group III). Subclavian and axilliary vascular injury occurred in 10 of 18 patients (55.6%) with a BPI. Brachial plexus injury occurred in 10 of 23 patients (43.5%) with a SAVI. Patients with SAVI from blunt trauma were significantly more likely to have an associated complete BPI than patients with penetrating trauma. All patients with a complete BPI (6 patients) had an associated SAVI regardless of mechanism of injury. Only one patient with a partial BPI from blunt trauma had an associated SAVI. The Injury Severity Score was significantly higher for patients in group II. An average of 2.8 and 3.3 associated injuries were observed in patients with SAVI (groups I and II) versus patients without SAVI (group III), respectively. No patient who had a complete BPI showed an improvement in neurologic status during a mean follow-up of 7.2 months. No late vascular sequelae occurred in group-III patients.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
82.
Nine patients have undergone single-stage radical cystectomy and ileal conduit urinary diversion two to fifty-one months after coronary artery bypass procedures. Two patients presenting with intractable angina at the time their malignant disease was being evaluated required bypass surgery before cystectomy could be undertaken. No significant cardiac morbidity occurred postoperatively, and all remain alive without evidence of malignant disease.  相似文献   
83.
Twenty-five patients with refractory anemia with excess blasts (RAEB) were studied. Five of these patients showed Auer rods in their myeloblasts, but met other criteria for RAEB. Median survival of the Auer rod-positive group was 14 months (range 2–27) from diagnosis with survival of 7 months after Auer rods were first observed. Median survival for the Auer rod-negative group was 12 months. Two patients developed overt acute leukemia, both from the Auer rod-negative group. The clinical course of Auer rod-positive RAEB, like that of Auer rod-negative RAEB, was one of progressive bone marrow failure complicated by infection, serious bleeding and the development of absolute transfusion requirement. These findings suggest that Auer rod-positive RAEB is a morphologic variant dysmyelopoietic syndrome that may pursue a similar clinical course to Auer rod-negative disease. Formulation of a separate treatment approach for those RAEB patients who possess Auer rods would appear ill advised.  相似文献   
84.
The radiobiology of osteoradionecrosis is a complex of cellular death and cellular functional impairments from radiation energy transfers. Four studies of irradiated patients and a data base from 536 patients with osteoradionecrosis revealed separate pathophysiologic conditions for osteoradionecrosis induced by early trauma, osteoradionecrosis induced by late trauma, and spontaneous osteoradionecrosis. A large body of data suggested useful clinical guidelines for the management of irradiated patients. The guidelines, in part, include a recommendation for deferring radiation treatment for 21 days after tissue wounding, if possible; a relative contraindication to wounding tissue during a radiation course; a recommendation for the use of hyperbaric oxygen before wounding; and a strong recommendation to provide comprehensive dental care to the irradiated patient.  相似文献   
85.
Galega officinalis L (goatsrue), a plant introduced from Europe and found in abundance in northern Utah, was tested for toxicity in ewes (Ovis aries). Clinical signs of poisoning induced by doses as small as 0.8 g of dried plant/kg body weight/day included dyspnea, anoxia, and foaming nasal discharge. Pathologic signs in animals that died following overdose of the plant included severe hydrothorax, generalized lung congestion, foamy exudate in bronchioles and trachea, epicardial and endocardial petechiation, and pericardial effusion in severely affected ewes. Microscopic lesions included a severe diffuse alveolar and interlobular edema. No significant alterations in blood constituents were observed in treated animals. Ewes administered the plant on several consecutive days developed an apparent adaptation to the toxin of the plant and were thereby able subsequently to tolerate levels 5-10 times the pre-treatment lethal dose with no discernible adverse clinical or pathological effects.  相似文献   
86.
The patient referral process is based on a complex set of social rewards and costs for the referring physician. For the physician or institution potentially receiving referrals, a key question is, why is one institution selected over other available choices? Factor analysis of a survey of rural physicians revealed five factors of reward and cost associated with the choice of where to refer patients. Further analysis of these factors suggested that the ability to have patients admitted and treated when necessary is central to the satisfaction of the referring physician and their willingness to continue the consultant relationship. Adequate information about the consultants was also important to satisfaction. Other factors have less influence. Further, “admissions when necessary” was the only reward/cost factor which predicted physicians who referred more to the university hospital than to other hospitals. If a university hospital wants to develop strategies to encourage referrals from rural physicians, it must be cognizant of these social reward-cost factors.  相似文献   
87.
PURPOSE: This study investigated the agreement and repeatability of five techniques of measuring tear meniscus height (TMH). METHODS: Pairs of TMH measurements were obtained from one eye of 25 normal subjects with five techniques: optical coherence tomography in cross-section (OCT) and optical pachymetry in cross-section (PACH), without fluorescein; and 5 minutes after the instillation of fluorescein, optical pachymetry en-face (SL-F) and in cross-section (SL-X), and video capture en-face (VC). These 10 measurements were taken on different days within a period of 21 days. Additionally, immediately successive replicates were taken at the first visit when VC was used, allowing for the separation of technique repeatability from true day-to-day variation in TMH. RESULTS: Ninety-five percent confidence intervals for the mean TMH and 95% repeatability coefficients for repeated testing on separate occasions were: 0.25 to 0.29 mm, 0.14 mm--OCT, 0.30 to 0.36 mm, 0.13 mm--PACH, 0.27 to 0.34 mm, 0.092 mm--SL-F, 0.35 to 0.41 mm, 0.19 mm--SL-X, and 0.30 to 0.38 mm, 0.088 mm--VC. Reported repeatability coefficients are averages because, despite a relatively narrow experimental range, the measurements of low TMH were generally more repeatable than those of large TMH. Ninety-five percent limits of agreement were wide for all pairwise comparisons and included zero, indicating that the methods used in this study are interchangeable when taking single recordings, at least on subjects without dry eye. CONCLUSIONS: The average TMH of the five techniques was similar, although OCT and SL-X tended to record lower and higher values, respectively. However, their agreement for single recordings was poor, an inevitable consequence of the low intertest repeatability found for all methods. A much improved repeatability for immediate replicates indicated that this, in turn, was principally caused by a large day-to-day variation in TMH rather than measurement error.  相似文献   
88.
This article examines whether there is any clinical value in anorectal physiology measurements. The function of the human rectum is poorly understood and the factors which affect function of the anal sphincters are complex. Several laboratories have reported results of anorectal physiology measurements, but there is extensive variation between normal values in different laboratories. It is argued that anorectal physiology measurements fail to meet the criteria of a useful clinical test: 1. It is not widely available to clinicians; 2. It is not possible to establish a reproducible normal range; 3. Abnormal measurements do not correlate with disease entities or explain symptoms; 4. The results are often unhelpful in diagnosis and management; 5. Clinical outcome after intervention does not correlate with alteration in the measurements obtained. On the other hand it can be argued that anorectal physiology measurements do provide information that assists in the management of conditions such as constipation, anismus, Hirschsprung''s disease, faecal incontinence and tenesmus. Management based on biofeedback modification of physiological responses requires these techniques as part of the biofeedback system. There is evidence that this may be appropriate in anismus and solitary rectal ulcer syndrome. However, the assessment of these difficult conditions and the interpretation of the results are probably at present best confined to specialist units.  相似文献   
89.
 Infantile myofibromatosis is a mesenchymal tumor most commonly seen in infancy. The tumors have a variable appearance on CT/MR and often simulate a more aggressive neoplasm. This report describes CT/MR findings in cases of infantile myofibromatosis with pathologic correlation. Discussion into the success of imaging in suggesting the correct diagnosis is also addressed. Infantile myofibromatosis is a mesenchymal disorder of infancy characterized by the presence of tumorous nodules in the skin, subcutaneous tissue, muscle, viscera, and bone. Cases of solitary and multiple lesions have been described. We present the clinical, histologic, and radiographic findings of one case of the solitary form of infantile myofibromatosis that was recently diagnosed at our hospital.  相似文献   
90.
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