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   3304篇
  免费   210篇
  国内免费   12篇
耳鼻咽喉   25篇
儿科学   166篇
妇产科学   53篇
基础医学   321篇
口腔科学   40篇
临床医学   312篇
内科学   778篇
皮肤病学   103篇
神经病学   252篇
特种医学   336篇
外科学   350篇
综合类   72篇
预防医学   193篇
眼科学   110篇
药学   175篇
中国医学   5篇
肿瘤学   235篇
  2022年   21篇
  2021年   41篇
  2020年   25篇
  2019年   46篇
  2018年   48篇
  2017年   36篇
  2016年   73篇
  2015年   59篇
  2014年   96篇
  2013年   105篇
  2012年   144篇
  2011年   165篇
  2010年   146篇
  2009年   132篇
  2008年   168篇
  2007年   152篇
  2006年   143篇
  2005年   146篇
  2004年   157篇
  2003年   149篇
  2002年   147篇
  2001年   47篇
  2000年   38篇
  1999年   67篇
  1998年   70篇
  1997年   77篇
  1996年   67篇
  1995年   69篇
  1994年   68篇
  1993年   67篇
  1992年   34篇
  1991年   34篇
  1990年   19篇
  1989年   56篇
  1988年   60篇
  1987年   48篇
  1986年   49篇
  1985年   50篇
  1984年   30篇
  1983年   40篇
  1982年   45篇
  1981年   32篇
  1980年   41篇
  1979年   16篇
  1978年   20篇
  1977年   19篇
  1976年   20篇
  1975年   26篇
  1974年   10篇
  1970年   14篇
排序方式: 共有3526条查询结果,搜索用时 31 毫秒
1.
Conventional risk factors have very low predictive power in identifying haemodialysis patients at high risk of vascular accidents. A role for apolipoprotein E isotypes was looked for in a small, but rigorously defined, cohort of longterm haemodialysis patients. In individuals with high vascular risk, as identified by higher common carotid intima/media thickness, we found an excess of apolipoprotein E4 alleles. This preliminary result requires confirmation in large patient cohorts.   相似文献   
2.
3.
4.
5.
6.
Computer technology has made it possible significantly to improve the technique and interpretation of the micturitional urethral pressure profile (MUPP). Thirty-nine patients with lower urinary tract symptoms have been investigated by this technique and the results compared with those of standard pressure/flow studies. A good correlation was found between the two methods of diagnosing outflow obstruction, but micturitional urethral pressure profiles offered practical advantages in patients who were elderly, immobile or who had severe involuntary voiding, and diagnostic advantages in patients with absent or poor detrusor contractility and those with equivocal pressure/flow studies.  相似文献   
7.
The influence of family history on DNA repair synthesis, unscheduledDNA synthesis (UDS), was assessed in volunteers with or withouta family history of cancer. UDS, following treatment of mononuclearleukocytes with N-acetoxy-2-acetylaminofluorene, was measuredas the incorporation of [3H] into DNA in the presence of hydroxyurea.The positive family history group (n=71) had an average of 2.4first-degree relatives with cancer, defined as any major cancer,excluding skin cancer: 31 participants reported that canceroccurred in both their parents. The ‘no family history’comparison group (n=29) had no family history of cancer throughthe second degree. There was a significant reduction in UDSin cells from individuals with family history, compared to thosewith no family history (P>0.002). This relationship was notexplained by factors known to influence UDS, such as age, smokingor hypertension. We conclude that reduced UDS in mononuclearleukocytes is associated with a family history of any majorcancer, and is not confined to a history of cancer of any singleorgan site. This conclusion is further supported by the observationthat individuals (n=13) with parents who had an earlier onsetof cancer (<60 years) also had a significantly lower DNArepair synthesis than those (n=18) whose parents had later diagnosisof cancer (>60 years).  相似文献   
8.
PURPOSE: In this investigation, we evaluated a population of patients with chronic orofacial pain who sought treatment at a pain center in an academic institution. These patients were evaluated with respect to 1) the frequency and types of previous oral and maxillofacial surgery procedures, 2) the frequency of previous significant misdiagnoses, and 3) the number of patients who subsequently required surgical treatment as recommended by an interdisciplinary orofacial pain team. The major goal of this investigation was to determine the role of oral and maxillofacial surgery in patients with chronic orofacial pain. Patients and Methods: The study population included patients seen at the Center for Oral, Facial and Head Pain at New York Presbyterian Hospital from January 1999 through April 2001. (120 patients; female-to-male ratio, 3:1; mean age, 49 years; average pain duration, 81 months; average number of previous specialists, 6). The patient population was evaluated by an interdisciplinary orofacial pain team and the following characteristics of this population were profiled: 1) the frequency and types of previous surgical procedures, 2) diagnoses, 3) the frequency of previous misdiagnoses, and 4) treatment recommendations made by the center team. RESULTS: There was a history of previous oral and maxillofacial surgical procedures in 38 of 120 patients (32%). Procedures performed before our evaluation included endodontics (30%), extractions (27%), apicoectomies (12%), temporomandibular joint (TMJ) surgery (6%), neurolysis (5%), orthognathic surgery (3%), and debridement of bone cavities (2%). Surgical intervention clearly exacerbated pain in 21 of 38 patients (55%) who had undergone surgery. Diagnoses included myofascial pain (50%), atypical facial neuralgia (40%), depression (30%), TMJ synovitis (14%), TMJ osteoarthritis (12%), trigeminal neuralgia (10%), and TMJ fibrosis (2%). Treatment recommendations included medications (91%), physical therapy (36%), psychiatric management (30%), trigger injections (15%), oral appliances (13%), biofeedback (13%), acupuncture (8%), surgery (4%), and Botox injections (1%) (Allergan Inc, Irvine, CA). Gross misdiagnosis leading to serious sequelae, with delay of necessary treatment, occurred in 6 of 120 patients (5%). CONCLUSIONS: Misdiagnosis and multiple failed treatments were common in these patients with chronic orofacial pain. These patients often have multiple diagnoses, requiring management by multiple disciplines. Surgery, when indicated, must be based on a specific diagnosis that is amenable to surgical therapy. However, surgical treatment was rarely indicated as a treatment for pain relief in these patients with chronic orofacial pain, and it exacerbated and perpetuated pain symptoms in some of them.  相似文献   
9.
Hodgkin disease: CT of the thymus   总被引:2,自引:0,他引:2  
Heron  CW; Husband  JE; Williams  MP 《Radiology》1988,167(3):647-651
The computed tomography (CT) scans in two groups of patients with Hodgkin disease were reviewed to determine the frequency of thymic enlargement. In 50 CT scans from 50 patients with evidence of thoracic disease on CT scans who were examined for primary staging, the thymus was enlarged in 15 of 50 (30%). Fifty CT scans were obtained from 44 patients at the time of 50 separate episodes of known or suspected relapse. Relapse occurred in the mediastinum in 12 episodes, lung parenchyma in five, and both sites in one. Thymic enlargement thought to be due to involvement by disease was present in seven of 18 (38%). Mediastinal disease was associated with thymic enlargement in all but one patient in whom a thymic cyst developed after radiation therapy. Differentiation of thymic enlargement from enlarged superior mediastinal lymph nodes was easily made in all but two patients. Thymic enlargement in the absence of lymph node enlargement may indicate a different disease, since isolated Hodgkin disease of the thymus is uncommon. Primary thymic tumor should be considered initially, whereas after treatment, rebound hyperplasia of the thymus may be the cause of enlargement.  相似文献   
10.
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