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   1481523篇
  免费   107823篇
  国内免费   2654篇
耳鼻咽喉   20584篇
儿科学   47807篇
妇产科学   42169篇
基础医学   213368篇
口腔科学   40043篇
临床医学   128648篇
内科学   293082篇
皮肤病学   29166篇
神经病学   118713篇
特种医学   56743篇
外国民族医学   379篇
外科学   228945篇
综合类   30011篇
现状与发展   3篇
一般理论   596篇
预防医学   112631篇
眼科学   33248篇
药学   111944篇
  2篇
中国医学   2824篇
肿瘤学   81094篇
  2018年   15601篇
  2017年   11997篇
  2016年   13307篇
  2015年   15465篇
  2014年   21757篇
  2013年   32818篇
  2012年   45943篇
  2011年   49426篇
  2010年   28836篇
  2009年   26843篇
  2008年   47709篇
  2007年   51439篇
  2006年   51429篇
  2005年   51190篇
  2004年   49374篇
  2003年   47511篇
  2002年   46543篇
  2001年   60438篇
  2000年   61569篇
  1999年   53006篇
  1998年   17022篇
  1997年   15244篇
  1996年   15288篇
  1995年   14343篇
  1994年   13491篇
  1993年   12503篇
  1992年   42468篇
  1991年   41742篇
  1990年   41206篇
  1989年   39914篇
  1988年   37367篇
  1987年   36584篇
  1986年   34955篇
  1985年   33435篇
  1984年   25541篇
  1983年   22356篇
  1982年   14155篇
  1981年   12540篇
  1979年   23628篇
  1978年   16954篇
  1977年   14738篇
  1976年   13841篇
  1975年   14938篇
  1974年   17452篇
  1973年   16761篇
  1972年   15849篇
  1971年   14675篇
  1970年   13646篇
  1969年   13097篇
  1968年   12274篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Health status of the underschool children from the second health group, which with having some morphofunctional changes, (503 persons) was studied. The key changes were postural, cardiovascular, neuropsychic changes. The lysozyme level in saliva is the informative index related to the health status of underschool children.  相似文献   
994.
995.
996.
AIMS: To compare long-term (1 year) efficacy and safety of pioglitazone and gliclazide in patients with Type 2 diabetes. METHODS: This was a double-blind, multicentre, comparative, parallel group trial in 283 patients with Type 2 diabetes, who were randomized to receive 1-year treatment with pioglitazone 30-45 mg/day or gliclazide 80-320 mg/day. Drug dose was titrated on the basis of self-monitored blood glucose (SMBG) measurements and HbA1c values. The 1-year changes in HbA1c, fasting blood glucose (FBG), insulin, HOMA-S (HOmeostatic Model Assessment) and SMBG were compared. In a subgroup of patients (n = 10), systemic glucose production and utilization were determined by a combination of isotopic (deuterated glucose) and clamp techniques. RESULTS: In both groups, there were similar decreases in HbA1c (pioglitazone: -0.79%; gliclazide: -0.79%) and FBG (pioglitazone: -1.0 mmol/l; gliclazide: -0.7 mmol/l), whereas the slope of the reduction of fasting blood glucose was different between groups (P = 0.004). Insulin levels as well as insulin resistance assessed using HOMA-S decreased significantly only after pioglitazone treatment (-11.94 pmol/l and -1.03, respectively, both P = 0.002 vs. baseline). A significantly greater reduction in systemic glucose production was observed in the pioglitazone group (-2.48 micromol/kg/min, P = 0.042) than in the gliclazide group (-1.02 micromol/kg/min). A few, mild adverse events occurred in both groups. CONCLUSIONS: A comparable decrease in HbA1c and FBG was observed with pioglitazone and gliclazide. However, with pioglitazone there was a continuous decrease in FBG over 1 year, whereas gliclazide failed to maintain a similar trend. This favourable effect of pioglitazone was due to its insulin-sensitizing effect and ability to decrease systemic glucose production.  相似文献   
997.
Background Oxidative stress and increased inflammation have been reported to be increased in subjects with diabetes and to be involved in the pathogenesis of cardiovascular complications after myocardial infarction (MI). It is well recognized that red wine has antioxidant and anti‐inflammatory activities. We examined the effects of moderate red wine intake on echocardiographic parameters of functional cardiac outcome in addition to inflammatory cytokines and nitrotyrosine (oxidative stress marker), in subjects with diabetes after a first uncomplicated MI. Methods One hundred and fifteen subjects with diabetes who had sustained a first non‐fatal MI were randomized to receive a moderate daily amount of red wine (intervention group) or not (control group). Echocardiographic parameters of ventricular dys‐synchrony, circulating levels of nitrotyrosine, tumour necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), interleukin‐18 (IL‐18) and C‐reactive protein (CRP) were investigated at baseline and 12 months after randomization. Results After 1 year of diet intervention, concentrations of nitrotyrosine (P < 0.01), CRP (P < 0.01), TNF‐α (P < 0.01), IL‐6 (P < 0.01) and IL‐18 (P < 0.01) were increased in the control group compared with the intervention group. In addition, myocardial performance index (P < 0.02) was higher, and transmitral Doppler flow (P < 0.05), pulmonary venous flow analysis (P < 0.02) and ejection fraction (P < 0.05) were lower in the control group, indicating ventricular dys‐synchrony. The concentrations of nitrotyrosine, CRP, TNF‐α and IL‐6 were related to echocardiographic parameters of ventricular dys‐synchrony. Conclusions In subjects with diabetes, red wine consumption, taken with meals, significantly reduces oxidative stress and pro‐inflammatory cytokines as well as improving cardiac function after MI. Moderate red wine intake with meals may have a beneficial effect in the prevention of cardiovascular complications after MI in subjects with diabetes.  相似文献   
998.
999.
Fragestellung: Die Karzinomassoziierte Retinopathie (CAR) stellt ein seltenes paraneoplastisches Syndrom dar, das bislang am h?ufigsten bei kleinzelligen Bronchialkarzinomen beschrieben wurde. Wir berichten über 3 Patientinnen mit CAR in Gegenwart eines Mammakarzinoms bzw. eines Karzinoids der Cervix uteri. Patienten und Methode: Es wurden biomikroskopische, perimetrische, angiographische und elektrophysiologische Befunde erhoben. Au?erdem erfolgte eine Testung der Immunreaktivit?t der Seren an humaner Retina. Ergebnisse: Die Befunde umfa?ten ringf?rmige Gesichtsfelddefekte mit statokinetischer Dissoziation und eine pathologische St?bchen- und Zapfenantwort im ERG. Bei 1 Patientin wurde immunhistochemisch eine Reaktion im Bereich der Photorezeptorinnensegmente, der ?u?eren K?rnerschicht sowie der ?u?eren plexiformen Schicht bei fehlendem Nachweis von Antik?rpern gegen Recoverin gefunden. Diskussion: Neben dem kleinzelligen Bronchialkarzinom k?nnen auch andere Prim?rtumoren mit einer CAR vergesellschaftet sein. Der Nachweis von retinalen Autoantik?rpern unterstützt die Annahme einer tumorinduzierten Immunantwort aufgrund der Expression identischer Epitope durch die Tumorzellen. Dabei kommen offensichtlich verschiedene retinale Proteine als Autoantigene in Betracht.   相似文献   
1000.
Background: Retinal pigment epithelium (RPE)lesions are predictive congenital phenotypic markersfor familial adenomatous polyposis (FAP). Thisprospective screening study aims at assessing theincidence and significance of these lesions in FAPpatients and their family members.Methods: Sixty-two members from three familiesincluding five patients with the diagnosis of FAP havebeen ophthalmologically surveyed. All RPE lesions weredocumented with fundus photography and fluoresceinangiography was performed in 13 subjects.Sigmoidoscopy and/or radiological examination wereperformed annually in 9 family members with typicalRPE lesions during 4 years to allow early diagnosis ofFAP.Results: Typical RPE lesions were present infive FAP patients and 15 family members.Telangiectatic dilatations in the retinal peripherywith small dot-like hemorrhages were detected in 6subjects from 3 families These lesions wereparticularly evident on fluorescein angiography.Annual colon analysis showed polyps in 3 out of 9subjects who were positive for RPE lesions.Conclusion: RPE lesions are valuable as aclinical marker in predicting FAP. The co-existingperipheral vascular alterations which have not beenreported before, are probably related to FAP.  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