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   7316篇
  免费   442篇
  国内免费   79篇
耳鼻咽喉   84篇
儿科学   67篇
妇产科学   128篇
基础医学   1199篇
口腔科学   190篇
临床医学   509篇
内科学   1337篇
皮肤病学   207篇
神经病学   482篇
特种医学   426篇
外科学   923篇
综合类   27篇
预防医学   235篇
眼科学   99篇
药学   997篇
中国医学   163篇
肿瘤学   764篇
  2024年   3篇
  2023年   32篇
  2022年   133篇
  2021年   279篇
  2020年   127篇
  2019年   149篇
  2018年   234篇
  2017年   158篇
  2016年   271篇
  2015年   418篇
  2014年   416篇
  2013年   490篇
  2012年   818篇
  2011年   723篇
  2010年   414篇
  2009年   343篇
  2008年   461篇
  2007年   368篇
  2006年   349篇
  2005年   372篇
  2004年   317篇
  2003年   237篇
  2002年   187篇
  2001年   107篇
  2000年   104篇
  1999年   72篇
  1998年   30篇
  1997年   32篇
  1996年   23篇
  1995年   14篇
  1994年   16篇
  1993年   8篇
  1992年   16篇
  1991年   25篇
  1990年   14篇
  1989年   10篇
  1988年   13篇
  1987年   9篇
  1986年   8篇
  1985年   7篇
  1984年   3篇
  1983年   2篇
  1981年   4篇
  1979年   3篇
  1976年   2篇
  1968年   2篇
  1967年   1篇
  1966年   3篇
  1965年   1篇
  1964年   1篇
排序方式: 共有7837条查询结果,搜索用时 15 毫秒
101.
102.
The computational fluid dynamics methods for the limited flow rate and the small dimensions of an intracranial artery stenosis may help demonstrate the stroke mechanism in intracranial atherosclerosis. We have modeled the high wall shear stress (WSS) in a severe M1 stenosis. The high WSS in the systolic phase of the cardiac cycle was well-correlated with a thick fibrous cap atheroma with enhancement, as was determined using high-resolution plaque imaging techniques in a severe stenosis of the middle cerebral artery.  相似文献   
103.
104.
AIM: To investigate the anti-diabetogenic mechanism of Nardostachys jatamansi extract (NJE). METHODS: Mice were injected with streptozotocin viaa tail vein to induce diabetes. Rat insulinoma RINm5F cells and isolated rat islets were treated with interleukin1β and interferon-γ to induce cytotoxicity. RESULTS: Treatment of mice with streptozotocin resulted in hyperglycemia and hypoinsulinemia, which was conf irmed by immunohistochemical staining of the islets. The diabetogenic effects of streptozotocin were c...  相似文献   
105.
Adoptive cytotoxic T lymphocyte (CTL) therapy has an important implication in treating cancer patients. Here, we investigate whether adoptive transfer of human papillomavirus (HPV) E7-specific CTL can enhance tumor chemoresponse using an established cervical cancer animal model. Cisplatin-based chemotherapy plus CTL therapy showed an improved therapeutic effectiveness, along with antitumor protective responses to a parental tumor cell rechallenge. Cisplatin treatment dose-dependently increased the expression of Fas, intercellular adhesion molecule (ICAM)-1, and major histocompatibility complex (MHC) class I antigens (Ags) on tumor cells in vitro. However, CTL-expressing FasL failed to improve antitumor activity in vitro and in animals, resulting from nonfunctional Fas expressed on tumor cells. In contrast, ethylene glycol tetraacetic acid (EGTA) treatment blocked increased sensitivity of cisplatin-treated tumor cells to CTL-mediated killing in vitro, suggesting an important role of the perforin/granzyme-mediated pathway for improved therapeutic effectiveness. This notion was further confirmed by perforin knockout animal studies. Thus, this study shows that (i) modulation of Ag (Fas, ICAM-1) expression by tumor cells has little effect on their increased sensitivity to CTL-mediated killing, (ii) improved therapeutic effectiveness is mediated mainly through the perforin/granzyme-mediated tumor killing pathway, and (iii) a combination of chemotherapy and adoptive E7-specific CTL transfer augments antitumor therapeutic activity in vivo. This finding may have important implications for treating HPV-associated cervical cancer.  相似文献   
106.
OBJECTIVE: To examine the accumulation of risk factors over 3 years in a multicenter, international inception cohort of patients with systemic lupus erythematosus (SLE). METHODS: The Systemic Lupus International Collaborating Clinics registry for atherosclerosis comprises 27 centers from 11 countries. An inception cohort of 935 patients with SLE was assembled, according to a standardized protocol, from 2000 to 2006 to study risk factors for atherosclerosis. Both classic and other coronary artery disease (CAD) risk factors were collected at entry and through 3 years of followup. Therapy was documented over the 3 years. The Framingham 10-year risk factor profile was calculated for each patient at year 1 and year 3. RESULTS: A total of 278 patients from the inception cohort were followed for 3 years and constituted the population for this study. At enrollment a substantial number of patients already demonstrated several risk factors for CAD, both classic and other. All risk factors increased from enrollment over the 3 years of followup. Treatment of hypertension and hypercholesterolemia also increased over 3 years, but less so for hypercholesterolemia. The Framingham 10-year CAD risk profile was higher in men than in women both at entry and at 3 years, and remained unchanged over the 3 years. Corticosteroid use increased only slightly over 3 years, but use of antimalarials and immunosuppressive agents increased to a greater extent. CONCLUSION: Patients with SLE should be monitored for CAD risk factors from the time of diagnosis and appropriate treatment should be instituted early.  相似文献   
107.

Background

Hepatic osteodystrophy has been reported in patients with various chronic liver diseases, including liver cirrhosis. However, it has not been well investigated in patients with hepatitis B virus infection. The aim of this study was to investigate the association between hepatitis B surface antigen (HBsAg) seropositivity and bone mineral density (BMD) in a population representative of normal Koreans.

Methods

Subjects with both HBsAg and BMD levels examined during the 2008–2010 Korea National Health and Nutrition Examination Surveys were included. HBsAg-seropositive (+) subjects were compared with those who were HBsAg-seronegative (?). BMD was measured at the lumbar spine and femur by dual-energy X-ray absorptiometry. Multivariable logistic regression was performed for BMD.

Results

In total, 11,306 participants were included in this study, among which 423 (3.7 %) were HBsAg(+): 153 premenopausal female (3.4 %), 83 postmenopausal female (3.5 %), and 187 male (4.2 %). Multivariable logistic regression analysis adjusted for age and body mass index showed that HBsAg(+) male had significantly lower BMD of the femoral neck than HBsAg(?) male (0.810 ± 0.009 vs. 0.827 ± 0.002 g/cm2, p = 0.035). Further adjustment for waist circumference, smoking, drinking, exercise, income, occupation, and vitamin D levels showed that HBsAg(+) male had significantly lower BMD of the femur neck (0.810 ± 0.010 vs. 0.831 ± 0.002 g/cm2, p = 0.032) and lumbar spine (0.953 ± 0.011 vs. 0.974 ± 0.003 g/cm2, p = 0.049) than HBsAg(?) male.

Conclusions

HBsAg seropositivity was significantly associated with lower BMD in male. Future long-term prospective studies investigating bone turnover markers and hormones are needed to better understand the pathophysiology and clinical significance of chronic hepatitis B virus-related hepatic osteodystrophy.
  相似文献   
108.
109.

Objective

To investigate the proxy‐reported health‐related quality of life (HRQOL) and its determinants in patients with juvenile idiopathic arthritis (JIA).

Methods

In this multinational, multicenter, cross‐sectional study, HRQOL of patients with JIA was assessed through the Child Health Questionnaire (CHQ) and was compared with that of healthy children of similar age from the same geographic area. Potential determinants of HRQOL included demographic data, physician's and parent's global assessments, measures of joint inflammation, Childhood Health Assessment Questionnaire (CHAQ), and erythrocyte sedimentation rate.

Results

A total of 6,639 participants (3,324 with JIA and 3,315 healthy) were enrolled from 32 countries. The mean ± SD physical and psychosocial summary scores of the CHQ were significantly lower in patients with JIA than in healthy children (physical: 44.5 ± 10.6 versus 54.6 ± 4.0, P < 0.0001; psychosocial: 47.6 ± 8.7 versus 51.9 ± 7.5, P < 0.0001), with the physical well‐being domain being most impaired. Patients with persistent oligoarthritis had better HRQOL compared with other subtypes, whereas HRQOL was similar across patients with systemic arthritis, polyarthritis, and extended oligoarthritis. A CHAQ score >1 and a pain intensity rating >3.4 cm on a 10‐cm visual analog scale were the strongest determinants of poorer HRQOL in the physical and psychosocial domains, respectively.

Conclusion

We found that patients with JIA have a significant impairment of their HRQOL compared with healthy peers, particularly in the physical domain. Physical well‐being was mostly affected by the level of functional impairment, whereas the intensity of pain had the greatest influence on psychosocial health.  相似文献   
110.
PURPOSE: To use a pooled analysis of the literature to find the incidence of and characteristics common to intracranial hemorrhage (ICH) associated with carotid artery stenting (CAS). METHODS: A search of the English-language literature (1996-2005) was performed in PubMed to find cases of CAS-associated ICH. Information was derived from the identified case studies in 5 categories and 19 aspects: (1) incidence of CAS-associated ICH; (2) demographic data (sex, age, symptom presentation, and presence of preexisting hypertension); (3) imaging data (side of lesion, degree of maximal stenosis, lesion location, status of the contralateral carotid artery, collateral circulation, and preprocedural imaging features); 4) procedure-related characteristics (antithrombotic medication, use of cerebral protection devices, residual stenosis, symptoms, interval from the procedure to ICH, type of ICH, and blood pressure changes); and (5) clinical outcome. RESULTS: Fifty-four cases of CAS-associated ICH were reviewed: 51 cases from 36 published articles and our own 3 cases. The incidence of CAS-associated ICH was 0.63% (95% CI 0.38% to 0.97%) in studies consisting of >100 cases, which was significantly lower (p<0.0001) than that of case series consisting of <100 cases (2.69%, 95% CI 1.75% to 3.94%). Distinctive features included symptomatic lesions, severe stenosis (> or =90%), maximal stenosis in the internal carotid artery (ICA) distal to the bifurcation, and preexisting cerebral infarction. CONCLUSION: The incidence of CAS-associated ICH was significantly lower in series consisting of >100 cases. More caution should be directed toward patients with symptomatic lesions, severe stenosis, maximal ICA stenosis distal to the carotid bifurcation, and preexisting cerebral infarction.  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