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   1935篇
  免费   186篇
  国内免费   6篇
耳鼻咽喉   17篇
儿科学   121篇
妇产科学   42篇
基础医学   208篇
口腔科学   26篇
临床医学   350篇
内科学   288篇
皮肤病学   10篇
神经病学   139篇
特种医学   202篇
外科学   260篇
综合类   115篇
一般理论   2篇
预防医学   145篇
眼科学   22篇
药学   115篇
中国医学   1篇
肿瘤学   64篇
  2022年   16篇
  2021年   22篇
  2020年   21篇
  2019年   18篇
  2018年   36篇
  2017年   20篇
  2016年   26篇
  2015年   37篇
  2014年   37篇
  2013年   51篇
  2012年   91篇
  2011年   74篇
  2010年   76篇
  2009年   38篇
  2008年   96篇
  2007年   95篇
  2006年   98篇
  2005年   104篇
  2004年   92篇
  2003年   74篇
  2002年   83篇
  2001年   69篇
  2000年   62篇
  1999年   64篇
  1998年   44篇
  1997年   43篇
  1996年   27篇
  1995年   30篇
  1994年   26篇
  1993年   23篇
  1992年   38篇
  1991年   31篇
  1990年   32篇
  1989年   58篇
  1988年   38篇
  1987年   41篇
  1986年   36篇
  1985年   30篇
  1984年   17篇
  1983年   21篇
  1982年   16篇
  1981年   17篇
  1980年   15篇
  1978年   13篇
  1976年   12篇
  1975年   13篇
  1974年   10篇
  1973年   16篇
  1972年   10篇
  1969年   14篇
排序方式: 共有2127条查询结果,搜索用时 0 毫秒
11.
The levels of the acute-phase reactant serum amyloid P-component (SAP) were measured by quantitative rocket immunoelectrophoresis in pregnant and non-pregnant DBA/1 female mice with or without collagen-induced rheumatoid arthritis (CIA). Non-pregnant animals with CIA showed elevated SAP titres related to the severity of the disease. Pregnancy alone also caused increased SAP levels equivalent to those found in animals with established CIA but which were virgin. The clinical remission seen in arthritic animals during pregnancy was not associated with reductions in circulating SAP levels. Increasing parity, however, caused a lowering of SAP levels in animals with or without CIA compared to the primiparous individuals. Pregnancy causes a strain-dependent elevation of serum SAP which is not further elevated by CIA, thus limiting the usefulness of SAP measurements in assessment of disease progression or remission during gestation.  相似文献   
12.
Traumatic brain injury (TBI) is a major public health problem. Caused by external mechanical forces, a major characteristic of TBI is the shearing of axons across the white matter, which causes structural connectivity disruptions between brain regions. This diffuse injury leads to cognitive deficits, frequently requiring rehabilitation. Heterogeneity is another characteristic of TBI as severity and cognitive sequelae of the disease have a wide variation across patients, posing a big challenge for treatment. Thus, measures assessing network‐wide structural connectivity disruptions in TBI are necessary to quantify injury burden of individuals, which would help in achieving personalized treatment, patient monitoring, and rehabilitation planning. Despite TBI being a disconnectivity syndrome, connectomic assessment of structural disconnectivity has been relatively limited. In this study, we propose a novel connectomic measure that we call network normality score (NNS) to capture the integrity of structural connectivity in TBI patients by leveraging two major characteristics of the disease: diffuseness of axonal injury and heterogeneity of the disease. Over a longitudinal cohort of moderate‐to‐severe TBI patients, we demonstrate that structural network topology of patients is more heterogeneous and significantly different than that of healthy controls at 3 months postinjury, where dissimilarity further increases up to 12 months. We also show that NNS captures injury burden as quantified by posttraumatic amnesia and that alterations in the structural brain network is not related to cognitive recovery. Finally, we compare NNS to major graph theory measures used in TBI literature and demonstrate the superiority of NNS in characterizing the disease.  相似文献   
13.
Objective. To evaluate the effect of a system of financial reward for emergency medical technicians (EMTs) who meet selected quality marker goals. Methods. This project was reviewed by an institutional review board (IRB) andwas found to be exempt from IRB review. Two operational andfour clinical markers were targeted for improvement. Baseline performance measurements were retrospectively measured for the preceding year, andchallenging but achievable goals for improvement were established. Operational markers included completing run reports within three hours after completion of the run andcall-to-en route (“out-of-chute”) times of less than 90 seconds for emergency calls on our first-line ambulance. Clinical markers included the use of aspirin in adults with nontraumatic chest pain, electrocardiogram (ECG) performance in adults with nontraumatic chest pain, documentation of pain assessment andintervention in patients with traumatic hip pain, anddocumentation of the time of onset of symptoms in stroke calls. Each full-time EMT could earn up to $1,000 in addition to baseline pay, with part-time EMTs eligible for prorated amounts. Results. Postincentive run reports were completed within three hours 99.7% of the time, with 21 of 24 providers meeting the goal 100% of the time. Before the incentive, reports were completed within three hours 64% of the time, with only two of 23 providers meeting the goal 100% of the time. The out-of-chute goal of less than 90 seconds was met 98.7% of the time, compared with 90.1% before the incentive. Aspirin use in adult nontraumatic chest pain improved from 68% to 96.3%, andECG performance in this group improved from 43% to 87.8%. Documentation of the time of onset of symptoms in stroke patients improved from 97% to 100%, andthe assessment of andintervention for pain in traumatic hip pain patients improved from 56% to 100%. Conclusion. Financial motivation improved targeted quality measures in this rural emergency medical service. It appears to be a useful adjuvant to traditional quality improvement mechanisms.  相似文献   
14.
BACKGROUND: Bilateral lung (BLTx) and heart-lung transplantation have gained wide acceptance as treatment of end-stage lung disease from cystic fibrosis. We reviewed our 13-year experience with thoracic transplantation for cystic fibrosis with an operative approach that favors use of cardiopulmonary bypass for BLTx. METHODS: Sixty-four patients with cystic fibrosis underwent heart-lung transplantation (n = 22, 34.4%) or BLTx (n = 42, 65.6%) between 1988 and 2000. Mean age and weight at transplantation were 29 +/- 8 years and 51 +/- 11 kg, respectively. Mean follow-up for survivors was 4.4 +/- 3.6 years. Immunosuppression regimen included cyclosporine, tapered corticosteroids, azathioprine, and induction therapy with OKT3 (murine monoclonal antibodies) or rabbit antithymocyte globulin. Cardiopulmonary bypass was used in all but 5 patients (7.8%). However, in 8 (19%) of the 42 patients having BLTx, only the grafting of the second lung was performed with cardiopulmonary bypass. RESULTS: The operative mortality rate was 1.6%. The actuarial survival rates at 1 year, 3 years, 5 years and 10 years were 93.2%, 77.7%, 61.8%, and 48.1%, respectively, with no significant difference between BLTx and heart-lung transplantation. The major hospital complications were pneumonia (n = 11, 17.2%) and bleeding (n = 8, 12.5%). Clinically significant reperfusion injury was observed in 6 patients, 3 of whom required reintubation. Freedom from acute lung rejection beyond 1 year was 47.7%. One patient underwent late retransplantation, and 4 required bronchial stenting. Obliterative bronchiolitis accounted for eight (50.0%) of 16 late deaths. CONCLUSIONS: Though postoperative bleeding and pneumonia are still of concern, satisfactory early and intermediate-term results can be expected in patients undergoing BLTx or heart-lung transplantation for cystic fibrosis. Cardiopulmonary bypass can be used for BLTx with no adverse impact on intermediate and long-term outcomes.  相似文献   
15.
16.
17.
Paget's bone disease is rare in young adults. Severe osteolytic Paget's bone disease in a 28-year-old man was found to respond, clinically, biochemically, and radiographically, within one month to daily subcutaneous injections of 0.5 mg of synthetic human calcitonin. After two years of therapy, he remains asymptomatic and has no biochemical evidence of Paget's bone disease while receiving injections three times a week. Despite aggressive disease, young patients may rapidly demonstrate the same beneficial response to synthetic human calcitonin therapy as has been observed in middle-aged or elderly patients with Paget's bone disease.  相似文献   
18.
Acute bouts of ultraendurance exercise may result in the appearance of biomarkers of cardiac cell damage and a transient reduction in left ventricular function. The clinical significance of these changes is not fully understood. There seems to be two competing issues to be resolved. First, could prolonged endurance exercise produce a degree of cardiac stress and/or damage that results, during the short or long term, in deleterious consequences for cardiac health. Second, there is a clear need to educate those responsible for the medical care of endurance athletes about the possibility of a transient reduction in cardiac function and the appearance of cTnT/cTnI after an exercise. Minor elevations in cardiac troponins are commonplace after an endurance exercise in elite and recreational athletes and may occur alongside exercise-associated collapse. Misdiagnosis of myocardial injury and subsequent mismanagement can be unnecessarily expensive and psychologically damaging to the athlete. Diagnosis of myocardial injury after prolonged exercise should be made on the basis of all available information and not blood tests alone. The clinical significance of chronic exposure to endurance exercise is unknown. The development of myocardial fibrosis has been suggested as a long-term outcome to chronic exposure to repetitive bouts of endurance exercise and has been linked to an exercise-induced inflammatory process observed in an animal model. This hypothesis is supported by a limited number of studies reporting postmortem studies in athletes and an increased prevalence of complex arrhythmia in veteran athletes. Care is warranted in promoting this hypothesis without further detailed work, given the unequivocal link between exercise and mortality and morbidity. It would seem erroneous, however, to assume that a linear relationship exists between exercise volume and cardiac health.  相似文献   
19.
20.
Boerhaave's syndrome: diagnosis and treatment   总被引:4,自引:0,他引:4  
Boerhaave's syndrome, or postemetic rupture of the esophagus,represents one of several etiologies of esophageal perforation. Early diagnosis, which requires both a high index of suspicion and contrast esophagography, is essential for optimal outcome. Primary repair is often possible, although other techniques, such as esophageal exclusion or diversion, may be appropriate in certain circumstances.  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