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   2877篇
  免费   131篇
  国内免费   11篇
耳鼻咽喉   24篇
儿科学   75篇
妇产科学   24篇
基础医学   465篇
口腔科学   44篇
临床医学   195篇
内科学   733篇
皮肤病学   18篇
神经病学   186篇
特种医学   60篇
外科学   518篇
综合类   4篇
预防医学   36篇
眼科学   18篇
药学   217篇
中国医学   11篇
肿瘤学   391篇
  2023年   24篇
  2022年   25篇
  2021年   77篇
  2020年   29篇
  2019年   51篇
  2018年   62篇
  2017年   61篇
  2016年   50篇
  2015年   62篇
  2014年   76篇
  2013年   74篇
  2012年   142篇
  2011年   174篇
  2010年   95篇
  2009年   65篇
  2008年   153篇
  2007年   152篇
  2006年   146篇
  2005年   184篇
  2004年   144篇
  2003年   140篇
  2002年   183篇
  2001年   45篇
  2000年   43篇
  1999年   43篇
  1998年   59篇
  1997年   31篇
  1996年   44篇
  1995年   37篇
  1994年   43篇
  1993年   31篇
  1992年   33篇
  1991年   39篇
  1990年   40篇
  1989年   39篇
  1988年   43篇
  1987年   35篇
  1986年   33篇
  1985年   35篇
  1984年   14篇
  1983年   9篇
  1982年   13篇
  1981年   20篇
  1980年   20篇
  1979年   8篇
  1978年   8篇
  1977年   8篇
  1975年   9篇
  1969年   9篇
  1966年   8篇
排序方式: 共有3019条查询结果,搜索用时 328 毫秒
71.
From 1982 to 1986, 1230 sudden death cases were autopsied in Osaka Medical Examiner's Office. Among them, 810 cases were sudden cardiac deaths (SCD) including coronary heart disease (77%), cardiomyopathy (7%), valvular disease (3%). All SCD cases were dead within 24 hours of the appearance of the fatal symptoms, and most of them (72%) were considered instantaneous death. Many of the fatal symptoms began in bed (31%), at bath (17%), at toilet (8%), or at work (8%). Thirty-four percent of them were thought by themselves or by their families to be healthy before the death. Hypertension (38%), coronary heart disease (13%) and diabetes mellitus (11%) were the major past history recorded. Microscopic observation of the hearts of 200 cases autopsied in 1986 showed various cardiac lesions: hypertrophy, atrophy, degenerations of myocytes, cellular and fatty infiltrations of the interstitium. According to their cardiac lesions and degrees of severity of coronary sclerosis, patients who died suddenly were divided into 8 groups as follows: 1. myocardial infarction (41) 2. myocarditis (6) 3. hypertrophic cardiomyopathy (19) 4. chronic ischemia with severe coronary sclerosis (65) 5. chronic ischemia with moderate coronary sclerosis (27) 6. small vessel disease (18) 7. amyloidosis (1) 8. unknown (23). These results suggest that coronary heart disease and hypertension play an important role in SCD.  相似文献   
72.
This report describes a case of hepatic phase Fasciola hepatica infection presenting huge and multilocular lesions. The unique radiological findings mimicked hydatid diseases and also cystic liver neoplasm. Fascioliasis should be included in the differential diagnosis for cystic liver diseases.  相似文献   
73.
Glomerular hyperfiltration plays a pathogenic role in the early stages of diabetic nephropathy. Experimental studies in laboratory animals suggest that nitric oxide (NO) might be involved in the pathogenesis of glomerular hyperfiltration. We performed a cross-sectional study to determine the relationship between diabetic glomerular hyperfiltration and the NO system. Normoalbuminuric (n=41), microalbuminuric (n=25), and macroalbuminuric (n=16) patients with type 2 diabetes were recruited in this study and compared with age-matched 84 non-diabetic control subjects. Creatinine clearance and urinary NO(2)(-)/NO(3)(-) excretion (urinary NOx) were measured, and the expression of endothelial cell nitric oxide synthase (ecNOS) was evaluated in human renal tissues. Glomerular hyperfiltration was present in 19 (37.5%) and nine (36.6%) of normoalbuminuric and microalbuminuric type 2 diabetic patients, respectively. The urinary NOx was significantly higher in normoalbuminuric patients compared with normal subjects. Creatinine clearance correlated significantly with urinary NOx in normoalbuminuric and microalbuminuric patients. Immunohistochemical staining intensities for ecNOS were significantly increased in glomerular endothelial cells of microalbuminuric type 2 diabetic patients as compared with the control subjects. These results suggest that NO may contribute to the pathogenesis of glomerular hyperfiltration in Japanese type 2 diabetic patients.  相似文献   
74.
75.
Motor imagery is defined as the mental execution of a movement without any muscle activity. In the present study, corticospinal excitability was assessed by motor evoked potentials (MEPs) when the subjects imagined isometric elbow flexion at various force levels. Electromyography was recorded from the right brachioradialis, the biceps brachii and the triceps brachii muscles. First, the maximum voluntary contraction (MVC) of elbow flexion was recorded in each subject. Subjects practiced performing 10, 30 and 60 % MVC using visual feedback. After the practice, MEPs were recorded during the imagery of elbow flexion with the forces of 10, 30 and 60 % MVC without any feedback. After the MEPs recording, we assigned subjects to reproduce the actual elbow flexion force at 10, 30 and 60 % MVC. The MEPs amplitudes in the brachioradialis and biceps brachii in the 60 % MVC condition were significantly greater than those in the 10 % MVC condition (p < 0.05). These findings suggest that the enhancement of corticospinal excitability during motor imagery is associated with an increase in imagined force level.  相似文献   
76.
The lungfish, the closest fish to tetrapods, has two types of sensory epithelia in the olfactory organ: the lamellar olfactory epithelium and the recess epithelium. The former resembles the olfactory epithelium of ordinary teleosts and the latter resembles the vomeronasal organ of tetrapods with respect to the G‐protein expressions and the morphological properties of olfactory receptor cells. In contrast to the lamellar olfactory epithelium covering the surface of olfactory lamella, the recess epithelium, together with the glandular epithelium, lines the recesses at the base of olfactory lamellae and is separated from the surrounding tissues by nonsensory epithelium. In the present study, we examined the distribution of these recesses and the relationship between the recess epithelium and the associated gland in the nasal sac of lungfish. We found that the posterior part of the nasal sac contained more recesses than the anterior one, and the medial one contained more recesses than the lateral one. In addition, virtually all recesses consisted of both the recess epithelium and the glandular epithelium. Furthermore, the glandular epithelium was invariably situated proximal to the midline raphe of the nasal sac, and the recess epithelium distal to it. Possible roles of the recess epithelium and the glandular epithelium are discussed.  相似文献   
77.
No specific therapy is available for COVID-19. We report the effectiveness and adverse effects of triple therapy with hydroxychloroquine, azithromycin, and ciclesonide in patients with COVID-19 pneumonia. The clinical condition of the patients improved within 5 days in response to the therapy.  相似文献   
78.
The FMS-related tyrosine kinase 3 (FLT3) internal tandem duplication mutations (FLT3-ITD) positive acute myeloid leukemia (AML) is a disease with a dismal outcome. Gilteritinib is a second-generation FLT3 inhibitor with activity against ITD and high affinity toward the FLT3 receptor, thereby showing therapeutic potential for relapsed/refractory FLT3-mutated AML. Bone marrow transplantation (BMT) from a human leukocyte antigen (HLA) identical sibling donor was performed in a 38-year-old Japanese male with FLT3-ITD positive AML. Neutrophil engraftment (>0.5 × 109/L) was achieved on day 16, and bone marrow remission was revealed on day 32. The patient's AML relapsed hematologically four months after BMT and was resistant to salvage chemotherapy. Gilteritinib was administered and the patient achieved non-remission but ‘stable disease’ status according to the response criteria. During administration, liver damage was observed but controllable. The patient received cord blood transplantation (CBT) as the second hematopoietic stem cell transplantation (HSCT) three months after relapse and achieved second remission. There was no evidence of recurrence of AML four months after CBT. This case demonstrates that gilteritinib can control FLT3-ITD positive AML that relapsed early after initial HSCT and can bridge to second HSCT.  相似文献   
79.
IntroductionSome clinicians administer antibiotics in adhesive SBO treatment to prevent bacterial translocation without evidence confirming reduced sepsis and mortality. We aimed to evaluate the effectiveness of preventive antibiotic administration in nonoperative treatment of adhesive small bowel obstruction (SBO) in a retrospective study.MethodsUsing a Japanese national inpatient database, we identified 114,786 eligible patients with adhesive SBO and divided patients into a group who did not receive intravenous antibiotics in the initial 2 consecutive days after admission (control group, n = 71,666) and a group who received intravenous antibiotics ≥2 days after admission (antibiotic group, n = 43,120). To compare the in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, length of stay, and total costs between the two groups, we performed instrumental variable analyses to adjust for measured and unmeasured confounding factors.ResultsOverall, in-hospital mortality was 2.2%, and the occurrence of sepsis was 0.8%. In the instrumental variable analyses, no significant differences were found for in-hospital mortality, occurrence of sepsis, septic shock, Clostridioides difficile colitis, or total hospitalization costs. The antibiotic group showed a longer length of stay than the control group (coefficient, 1.9 days; 95% confidence interval, 0.6–3.2).ConclusionsIn this large nationwide cohort of patients with adhesive SBO, we found no benefit regarding preventive antibiotic administration in nonoperative treatment; however, antibiotic administration was associated with a longer hospital stay. These results did not support routine administration of antibiotics at admission to prevent bacterial translocation.  相似文献   
80.
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