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   852篇
  免费   44篇
  国内免费   1篇
耳鼻咽喉   7篇
儿科学   83篇
妇产科学   20篇
基础医学   92篇
口腔科学   14篇
临床医学   58篇
内科学   148篇
皮肤病学   23篇
神经病学   45篇
特种医学   40篇
外科学   112篇
综合类   12篇
预防医学   50篇
眼科学   46篇
药学   98篇
中国医学   6篇
肿瘤学   43篇
  2023年   7篇
  2022年   28篇
  2021年   41篇
  2020年   27篇
  2019年   32篇
  2018年   37篇
  2017年   33篇
  2016年   28篇
  2015年   41篇
  2014年   38篇
  2013年   58篇
  2012年   67篇
  2011年   83篇
  2010年   41篇
  2009年   24篇
  2008年   49篇
  2007年   42篇
  2006年   53篇
  2005年   30篇
  2004年   24篇
  2003年   36篇
  2002年   32篇
  2001年   8篇
  2000年   5篇
  1999年   2篇
  1998年   2篇
  1997年   2篇
  1996年   8篇
  1995年   2篇
  1994年   1篇
  1993年   2篇
  1992年   2篇
  1991年   2篇
  1989年   2篇
  1987年   1篇
  1984年   1篇
  1983年   2篇
  1981年   1篇
  1957年   1篇
  1956年   1篇
  1955年   1篇
排序方式: 共有897条查询结果,搜索用时 0 毫秒
21.

Objective

To assess the prevalence of first hour breastfeeding initiation and exclusive breastfeeding at 6 wk and identify its barriers in healthy term babies born in a tertiary hospital setting.

Methods

A prospective observational cohort study was carried out in consecutively selected 400 mothers who delivered (normal, instrumental or cesarean) term healthy babies in a tertiary care hospital setting. All mother-infant dyads were enroled within 48 h of delivery.

Results

Breastfeeding was initiated within first hour in 255 out of 400, i.e., 64 % of babies. Cesarean delivery and male gender were strongest risk factors for delayed initiation of breastfeeding [OR (95 % CI)?=?1.99 (1.14–3.48) and 34.17 (17.10–70.40) respectively]. Among the babies followed up till 6–8 wk, 83 % were exclusively breastfed. Breast milk substitutes were given in 172/400 (43 %) babies on day one, which emerged as an independent predictor of failure to continue exclusive breastfeeding at 6 wk (OR 2.96; 95 % CI 1.09–8.06). Odds of exclusive breastfeeding were two times higher in babies breastfed within first hour (n?=?255/400, 64 %) when compared to babies initiated breastfeeds beyond first hour (n?=?145/400, 36 %) (OR 2.01;05 % CI 1.12–3.61).

Conclusions

Cesarean section and male gender emerged as significant risk factors for delayed initiation (beyond first hour) of breastfeeding in the index study cohort. In addition, use of breast milk substitute emerged as the only predictor for failure to continue exclusive breastfeeding at six weeks in a tertiary care hospital.  相似文献   
22.
23.
24.
While the cause of dopaminergic neuronal cell death in Parkinson's disease(PD)is not yet understood,many endogenous molecules have been implicated in its pathogenesis.β-phenethylamine(β-PEA),a component of various food items including chocolate and wine,is an endogenous molecule produced from phenylalanine in the brain.It has been reported recently that long-term administration ofβ-PEA in rodents causes neurochemical and behavioral alterations similar to that produced by parkinsonian neurotoxins.The toxicity ofβ-PEA has been linked to the production of hydroxyl radical(.OH)and the generation of oxidative stress in dopaminergic areas of the brain,and this may be mediated by inhibition of mitochondrial complex-I.Another significant observation is that administration ofβ-PEA to rodents reduces striatal dopamine content and induces movement disorders similar to those of parkinsonian rodents.However,no reports are available on the extent of dopaminergic neuronal cell death after administration ofβ-PEA.Based on the literature,we set out to establishβ-PEA as an endogenous molecule that potentially contributes to the progressive development of PD.The sequence of molecular events that could be responsible for dopaminergic neuronal cell death in PD by consumption ofβ-PEA-containing foods is proposed here.Thus,long-term over-consumption of food items containingβ-PEA could be a neurological risk factor having significant pathological consequences.  相似文献   
25.
Although recently the incidence of prehypertension has increased considerably, the pathophysiological mechanisms and the effects of gender in its causation have not yet been fully elucidated. Therefore, in this study body mass index (BMI), waist-hip ratio (WHR), basal heart rate (BHR), blood pressure (BP), rate pressure product (RPP), and spectral indices of heart rate variability (HRV) were reordered and analyzed in normotensive and prehypertensive males and females. It was observed that low frequency-high frequency (LF-HF) ratio, the sensitive indicator of sympathovagal imbalance (SVI), is significantly more (P < .001) in male prehypertensives compared with female prehypertensives. Although SVI in prehypertensives was found to be due to both sympathetic activation and vagal inhibition, contribution of vagal withdrawal was prominent in males. The LF-HF ratio was significantly correlated with BMI, WHR, BHR, BP, and RPP, which was more prominent in male prehypertensives and the degree of correlation was more for WHR and diastolic pressure. It was concluded that vagal inhibition plays an important role in critical alteration of SVI in the genesis of prehypertension, especially in males, and WHR could be a better indicator of SVI in prehypertensives. It was suggested that prehypertensives should improve their vagal tone to restore the sympathovagal homeostasis.  相似文献   
26.

Aim

A retrospective study of vesicouterine fistulae managed from 1996 to 2011 analyzed the incidence, symptomatology, diagnosis, and surgical outcome.

Patients & methods

During the study period, 17 patients were managed, of whom 14 underwent abdominal repair and three underwent vaginal repair. Mean patient age was 31.1 years and mean follow-up 7.3 years.

Results

Vesicouterine fistulae resulted following cesarean section in 13 patients and vaginal delivery in four. Eleven patients presented with urinary leakage via the vagina and seven with menouria. All patients had successful outcomes irrespective of treatment approach. The uterus was conserved in ten patients, of whom seven had completed their childbearing. The remaining three conceived spontaneously and underwent elective cesarean section.

Conclusion

The majority of vesicouterine fistulae occur following cesarean section, and it is feasible to achieve 100 % successful repair. Though the majority require abdominal repair, a few selected cases can be successfully repaired vaginally.  相似文献   
27.
Study objectiveGabapentin is an inhibitory neurotransmitter of the central nervous system. This prospective randomized double-blind study was conducted to evaluate the effects of gabapentin on intraoperative propofol requirements, hemodynamic variables, and postoperative pain relief in breast cancer patients.Materials and methodsForty adult females of the American Society of Anesthesiologists (ASA) Grade I-II physical status, undergoing total mastectomy for breast cancer were included. Patients were randomly allocated into two groups. Two hours prior to surgery the gabapentin group received gabapentin 600 mg and the control group received placebo. Anesthesia was induced with intravenous fentanyl, propofol, and vecuronium, and maintained with propofol infusion titrated according to the bispectral index. Postoperative analgesia was provided with intramuscular diclofenac sodium and intravenous morphine on demand.ResultsThe intraoperative propofol consumption was significantly less in the gabapentin group as compared with the control group (p = 0.009), whereas there was no difference in fentanyl and vecuronium requirements. Patients in the gabapentin group had lower pain scores at 30 minutes, 1 hour, and 2 hours postoperatively (p < 0.001). The postoperative morphine consumption was also less in the gabapentin group compared with the control group (p = 0.006). No significant adverse effects were noticeable.ConclusionPreoperative administration of gabapentin reduced intraoperative propofol requirements and postoperative analgesic consumption in breast cancer patients undergoing total mastectomy.  相似文献   
28.
Distal radius fractures are the most common upper extremity fracture and account for approximately one sixth of all fractures treated in US emergency departments. These fractures are associated with significant morbidity and have a major economic impact. Radiographic evaluation of distal radius fractures is frequently performed in the emergency department setting, has a profound impact on initial management, and is essential to assessing the quality and relative success of the initial reduction. While the most appropriate definitive management of distal radius fractures remains controversial, overarching treatment principles reflect distal radius injury mechanisms and biomechanics. An intuitive understanding of the biomechanics of the distal radius and of common mechanisms of injury informs and improves the emergency radiologist’s ability to identify key imaging findings with important management implications and to communicate the critical information that emergency physicians and orthopedic surgeons need to best manage distal radius fractures.  相似文献   
29.
Leishmania donovani is an intracellular protozoan parasite that impairs the host macrophage immune response to render it suitable for its survival and establishment. L. donovani-induced immunosuppression and alteration of host cell signaling is mediated by ceramide, a pleiotropic second messenger playing an important role in regulation of several kinases, including mitogen-activated protein kinase and phosphatases. We observed that the endogenous ceramide generated during leishmanial infection led to the dephosphorylation of protein kinase B (PKB) (Akt) in infected cells. The study of ceramide-mediated Akt phosphorylation revealed that Akt was dephosphorylated at both Thr308 and Ser473 sites in infected cells. Further investigation demonstrated that ceramide was also responsible for the induction of PKCzeta, an atypical Ca-independent stress kinase, as well as the ceramide-activated protein phosphatases (e.g., protein phosphatase 2A [PP2A]). We found that Akt dephosphorylation was mediated by ceramide-induced PKCzeta-Akt association and PP2A activation. In addition, treatment of L. donovani-infected macrophages with PKCzeta-specific inhibitor peptide could restore the translocation of phosphorylated Akt to the cell membrane. This study also revealed that ceramide is involved in the inhibition of proinflammatory cytokine tumor necrosis factor alpha release by infected macrophages. These observations strongly suggest the importance of ceramide in the alteration of normal cellular functions, impairment of the kinase/phosphatase balance, and thereby establishment of leishmaniasis in the hostile macrophage environment.  相似文献   
30.
A rare case of primary mucinous eccrine carcinoma of the lower eyelid in a 45 year old female is described. The lesion was diagnosed clinically as melanoma. We report this case because of unusual nature of this tumor and rare presentation in a female patient.  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