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   3842篇
  免费   194篇
  国内免费   32篇
耳鼻咽喉   15篇
儿科学   105篇
妇产科学   30篇
基础医学   443篇
口腔科学   77篇
临床医学   314篇
内科学   1057篇
皮肤病学   56篇
神经病学   257篇
特种医学   113篇
外科学   810篇
综合类   23篇
预防医学   78篇
眼科学   14篇
药学   272篇
中国医学   30篇
肿瘤学   374篇
  2023年   25篇
  2022年   46篇
  2021年   94篇
  2020年   67篇
  2019年   72篇
  2018年   88篇
  2017年   67篇
  2016年   62篇
  2015年   72篇
  2014年   107篇
  2013年   122篇
  2012年   223篇
  2011年   227篇
  2010年   108篇
  2009年   96篇
  2008年   208篇
  2007年   184篇
  2006年   191篇
  2005年   230篇
  2004年   208篇
  2003年   179篇
  2002年   185篇
  2001年   72篇
  2000年   88篇
  1999年   85篇
  1998年   67篇
  1997年   51篇
  1996年   41篇
  1995年   43篇
  1994年   35篇
  1993年   35篇
  1992年   62篇
  1991年   59篇
  1990年   61篇
  1989年   54篇
  1988年   45篇
  1987年   48篇
  1986年   37篇
  1985年   42篇
  1984年   32篇
  1983年   32篇
  1982年   17篇
  1981年   12篇
  1979年   19篇
  1978年   20篇
  1977年   19篇
  1974年   14篇
  1973年   13篇
  1971年   16篇
  1970年   19篇
排序方式: 共有4068条查询结果,搜索用时 15 毫秒
81.
The process of inflammation and immune response is regulated by proinflammatory cytokines. Interleukin-6 (IL-6), one of the proinflammatory cytokines, plays a potentially critical role in viral-induced myocarditis. Our previous work demonstrates that exogenous IL-6 administration, given at the time of encephalomyocarditis virus (EMCV) inoculation in C3H/HeJ mice, has a protective effect on myocardium and improves survival rates. In the present study, we examined whether overexpression of IL-6 modified viral myocarditis. On day 3 and 10 after inoculation with EMCV, the ratio of heart weight to body weight and myocardial injury were significantly increased in IL-6 transgenic mice (IL-6TG). On day 3, a reduction of viral clearance was shown by the presence of elevated viral titers and viral replication in the heart of IL-6TG. The concentrations of serum tumor necrosis factor- alpha (TNF alpha) were dramatically increased in wild-type mice on day 1, in contrast, this change was not observed in IL-6TG. Treatment with recombinant human TNF (2 microg) significantly improved viral clearance in the IL-6TG hearts. Thus, overexpression of IL-6 promotes myocardial injury by interrupting both the cytokine network and viral clearance. These experiments suggest the possibility that IL-6 is one of the factors that accelerates tissue damage, including myocardial injury, in the viral myocarditis.  相似文献   
82.
BACKGROUND: Acute massive or submassive pulmonary embolism (PE) has high mortality, but the clinical course according to the location of onset (ie, in-hospital or out-of-hospital) is unknown. METHODS AND RESULTS: In the present study 56 consecutive patients with acute massive or submassive PE were studied retrospectively and a comparison made of the clinical characteristics, and outcomes between in-hospital onset (Group A) and out-of-hospital onset (Group B). Patients in Group A (n=28) had more frequent comorbidities with hemodynamic instability (54% vs 4%, p<0.0001) and temporary risk factors (93% vs 11%, p<0.0001), whereas patients in Group B (n=28) had a longer duration of symptoms (median: 5.5 days vs 0.5 day; p<0.0001), and had higher systolic pulmonary artery pressure (63+/-17 mmHg vs 46+/-12 mmHg, p=0.0006). Although in-hospital mortality did not differ between the 2 groups, the recurrence rate was higher in Group B (23% vs 0%, p=0.03). CONCLUSIONS: Patients who had in-hospital onset of PE had mostly temporary risk factors, unstable hemodynamics and a lower recurrence rate compared with the cases of out-of-hospital onset. In cases of in-hospital onset, prompt diagnosis and suitable treatment is needed to prevent fatalities and cases of out-of-hospital onset should be followed carefully for recurrence.  相似文献   
83.
BackgroundIntrathoracic involvement with lymphomas is common and manifests lymphadenopathy as well as a wide spectrum of imaging abnormalities in the lungs. Intravascular large B-cell lymphoma (IVLBCL) is a rare extranodal subtype of large B-cell lymphoma that typically involves small blood vessels and is difficult to detect.MethodsUsing a computer-assisted search, we identified patients with histopathologically proven IVLBCL in the lungs at Mayo Clinic from 2001 through 2018. Medical records, imaging studies, and pathologic specimens were reviewed.ResultsA total of 5 patients were diagnosed with a median age at diagnosis of 68 years (range, 44-73); 4 patients were male. The diagnosis of IVLBCL was achieved by surgical lung biopsy in 3 and at autopsy in 2. At presentation, all 5 patients had dyspnea and systemic symptoms including fever, fatigue, night sweats, and/or weight loss. Chest radiography and computed tomography (CT) failed to demonstrate the diffuse infiltrative process; positron emission tomography (PET) scan performed in 2 patients did not show fluorodeoxyglucose (FDG) uptake in the lungs. Pulmonary function tests obtained in 3 patients showed reduced diffusing capacity in all; transthoracic echocardiography yielded evidence of pulmonary hypertension in 2 of 4 patients. All 3 patients diagnosed antemortem underwent chemotherapy with 1 patient remaining alive at 4 years after diagnosis.ConclusionsIVLBCL is difficult to diagnose given variable and nonspecific clinical presentations. Microvascular disease processes such as IVLBCL should be kept in mind in cases of undiagnosed progressive dyspnea accompanied by systemic symptoms even when imaging studies are unrevealing.  相似文献   
84.
85.
Along with the increased use of other laparoscopic procedures, laparoscopic inguinal hernia repair has become widely used because of its minimally invasive nature. Here, we report a case of 66‐year‐old man who underwent transabdominal preperitoneal laparoscopic hernioplasty and developed hemorrhagic shock on postoperative day 1. CT showed postoperative venous hemorrhage from the retropubic space. Successful hemostasis of the massive hemorrhage was achieved laparoscopically. The origin of the hemorrhage was assumed to be the corona mortis vein, which was slightly injured during the operation. Despite the rarity of this complication, surgeons must be aware of the need to carefully dissect and fix the mesh in the retropubic space to avoid injuring the corona mortis. Laparoscopic hemostasis may be an effective alternative to the open approach.  相似文献   
86.
At present, vancomycin (VCM) and metronidazole (MNZ) are used for the first-line standard treatment of Clostridioides difficile infection (CDI). However, their differential use has not been sufficiently investigated. In this study, a meta-analysis on differences in the efficacy for CDI between VCM and MNZ was performed. Reports of randomized controlled studies using VCM or MNZ to treat CDI were surveyed. Meta-analysis was performed using the Mantel-Haenszel method and random-effects model, and the risk ratio and 95% confidence interval were calculated. Excluding overlapping reports, 1043 reports were extracted and 5 randomized controlled studies were extracted. There was no difference in therapeutic effects for CDI between VCM and MNZ (RR = 1.08, 95% CI (0.99–1.17), p = 0.09, I2 = 37%). On subgroup analysis by the severity, there was no difference in the clinical effects for CDI between VCM and MNZ in non-severe cases (risk ratio: 1.09, 95% confidence interval: 1.00–1.19, p = 0.06), but the clinical effects of VCM were significantly higher than those of MNZ in severe cases (risk ratio: 1.19, 95% confidence interval: 1.02–1.39, p = 0.03). No significant difference was noted in the recurrence rate, incidence of adverse event, time to exhibit therapeutic effects, or judgment of the bacteriological effects. As the therapeutic effects of VCM were superior in severe CDI cases, VCM should be considered first in severe cases.  相似文献   
87.
An 83-year-old previously self-sufficient man was referred to our hospital for a fever, severe tenderness over the lumbar spine, and elevated C-reactive protein levels. Computed tomography revealed fluid collection in the intervertebral space of L3/4. Gram-positive, short rod-shaped bacteria were isolated from two sets of blood cultures. A 16S rRNA sequence analysis of an isolate showed a similarity of 98.1% to the nearest type strain Brachybacterium squillarum JCM 16464T. Biochemical characteristics of the presently isolated strain differed from those of the most closely related species of the genus Brachybacterium. The patient was successfully discharged on day 73 of admission with antimicrobial therapies and showed no recurrence during outpatient visits. Brachybacterium spp. have mainly been isolated from the environment, and human Brachybacterium infections have rarely been documented to date. To our knowledge, this is the first clinical isolation of Brachybacterium sp. as a causative pathogen of bloodstream infection.  相似文献   
88.
Clinical Rheumatology - Eosinophilic fasciitis (EF) is a rare connective tissue disease that causes inflammation and fibrosis of the fascia, inducing pain and motor dysfunction. Characteristic skin...  相似文献   
89.
Objective The psychological status is a key factor in smoking continuance. However, details on short-term changes in mild depressive states after smoking cessation (SC) are still unknown. The purpose of the present study was to investigate these short-term changes. Methods A total of 989 patients who visited our SC Clinic were assessed using the Zung Self-Rating-Depression-Scale (SDS), an official instrument to measure depressive tendencies. The participants were classified into normal and neurotic groups based on their SDS scores during their initial visit; they were assessed again 2, 4, 8, and 12 weeks thereafter. Results The majority of patients in the neurotic group were women. These patients were also younger, with a higher nicotine dependence, and presented with a lower successful SC rate than the patients in the normal group. A decrease in SDS scores after starting the SC treatment was observed only in the neurotic group, especially during the first two weeks. In patients who continued to smoke, no improvement in depressive tendencies was noted in this period. Conclusion Depressive tendencies of patients with neurosis improve in the initial stages of the SC treatment (i.e., within two weeks after starting the treatment). This finding fills the mentioned knowledge gap regarding the effects of SC on mild depressive states in the short term.  相似文献   
90.
BACKGROUND: A prospective randomized study compared the preventive effects of ticlopidine plus aspirin therapy versus cilostazol plus aspirin therapy on subacute thrombosis (SAT) and restenosis after coronary stenting. METHODS AND RESULTS: After successful stenting of 327 coronary lesions in 282 consecutive patients, the patients were randomized to receive ticlopidine (200 mg/day) or cilostazol (200 mg/day). Aspirin (81 mg/day) was administered concomitantly in both groups. SAT occurred in 1 patient in the ticlopidine group (0.7%) and in 8 patients in the cilostazol group (5.6%, p=0.037). Based on follow-up angiography, restenosis occurred in 30 patients (23.3%) in the ticlopidine group and 35 patients (26.9%) in the cilostazol group (NS). The late loss was significantly smaller in the cilostazol group than the ticlopidine group (1.08+/-0.95 mm vs 0.78+/-0.93 mm, respectively, p=0.037). No significant differences between the 2 groups were observed with respect to the rates of total death, non-fatal cardiovascular events, or bleeding complications. CONCLUSION: The ticlopidine group showed significantly less SAT after stenting compared with the cilostazol group. After 6 months of treatment, the inhibition of neointimal proliferation was greater in the cilostazol group than in the ticlopidine group, but the prevention of restenosis was not confirmed.  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