全文获取类型
收费全文 | 2562篇 |
免费 | 155篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 56篇 |
妇产科学 | 132篇 |
基础医学 | 246篇 |
口腔科学 | 70篇 |
临床医学 | 211篇 |
内科学 | 532篇 |
皮肤病学 | 29篇 |
神经病学 | 184篇 |
特种医学 | 114篇 |
外国民族医学 | 3篇 |
外科学 | 469篇 |
综合类 | 27篇 |
一般理论 | 3篇 |
预防医学 | 111篇 |
眼科学 | 107篇 |
药学 | 172篇 |
中国医学 | 2篇 |
肿瘤学 | 233篇 |
出版年
2024年 | 2篇 |
2023年 | 22篇 |
2022年 | 45篇 |
2021年 | 113篇 |
2020年 | 78篇 |
2019年 | 105篇 |
2018年 | 160篇 |
2017年 | 111篇 |
2016年 | 87篇 |
2015年 | 90篇 |
2014年 | 123篇 |
2013年 | 145篇 |
2012年 | 225篇 |
2011年 | 220篇 |
2010年 | 140篇 |
2009年 | 92篇 |
2008年 | 161篇 |
2007年 | 155篇 |
2006年 | 126篇 |
2005年 | 119篇 |
2004年 | 109篇 |
2003年 | 113篇 |
2002年 | 98篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 13篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有2730条查询结果,搜索用时 78 毫秒
121.
Tarek A Abdel-Gawad Mostafa A El-Hodhod Hanan M Ibrahim Yousef W Michael 《Critical care (London, England)》2009,13(5):R164-5
Introduction
The objective was to determine the frequency of gastroesophageal reflux (GER) in mechanically ventilated pediatric patients and its role as a risk factor for ventilator-associated pneumonia (VAP), which may be enhanced among those patients. 相似文献122.
123.
Osama A. Mohamed Carol J. Bennett Mohamed Farid Roaiah Tarek Helmy Ali Mahran Hamed A. Hamed 《The journal of sexual medicine》2009,6(4):1081-1089
IntroductionErectile dysfunction and ischemic heart disease are common health problems that affect elderly individuals. Despite advances in treatment strategies, cardiopulmonary bypass (CPB) has been used for coronary artery bypass grafting (CABG) for over three decades for surgical myocardial revascularization.AimTo discuss the difference between the on pump and the newer alternative—the off-pump CABG (OPCABG) surgery—on the sexual function.MethodsThis prospective study included 100 patients who underwent CABG.Main Outcome MeasuresThe patients were evaluated by an abridged form of International Index of Erectile Function questionnaire (IIEF-5), Pharmaco-Penile Duplex Ultrasound and finally by the European System for Cardiac Operative Risk Evaluation. The patients were underwent either on-pump CABG or OPCABG. Six months after surgery, the erectile function was revaluated according to the same preoperative measures.ResultsPatients included in the study were classified into two matched groups: group I—patients who underwent on-pump CABG (N = 50); and group II—patients who underwent OPCABG (N = 50). The frequency of intercourse was significantly higher in OPCABG (P < 0.05) after surgery. The mean ± standard deviation of the IIEF-5 scores of the on-pump group postoperatively became 12.48 ± 7.19 whereas it became 15.88 ± 6.67 in the off-pump group (P < 0.05). Moreover, the number of patients who reported postoperative improvement of their IIEF-5 score was significantly higher in OPCABG group (N = 23) compared with the conventional on-pump CABG group (N = 13) (P < 0.05). There was no significant change in the duplex ultrasound after surgery between both groups.ConclusionsThe OPCABG has a diminished impact on the sexual function of patients compared with the conventional on-pump CABG. Therefore, the type of operation can be considered a predictive factor of sexual function following CAB surgery. Mohamed OA, Bennett CJ, Farid RM, Helmy T, Mahran A, and Hamed HA. The impact of on-pump coronary artery bypass surgery vs. off-pump coronary artery bypass surgery on sexual function. J Sex Med **;**:**–**. 相似文献
124.
Hmed Ben Nasr Hammami Serria Selma Chaker Badraoui Riadh Sahnoun Zouheir Jamoussi Kamel Rebai Tarek Zeghal Khaled 《Experimental and toxicologic pathology》2009,61(6):573-580
Scorpion envenoming is less studied during gestation; however, it may induce various biological disturbances in maternal organism and hypothetical ones on their fetuses. The scope of this report was to elucidate some biological effects of such poisoning in late pregnant rats. Hence, TBARS levels in maternal lung, placental and fetal pulmonary and hepatic tissues and dam's biochemical blood parameters (glucose, creatinine, 17-β estradiol, progesterone, blood nitrogen urea, sodium and potassium maternal plasma concentrations) had been evaluated after saline (G1), and scorpion venom (G2: 30 min and G3: 60 min) injections in 22nd day pregnant rats. Histological microscopic examination of these tissues was also carried out in HE-stained paraffin sections. In addition, the mean arterial blood pressure following the envenomation variations was measured in three rats from the same pool. Our results showed that Buthus occitanus tunetanus crude venom induced significant increase in maternal, placental and fetal tissues lipid peroxidation, concomitant with blood pressure elevation. Maternal plasma creatinine, estradiol and progesterone concentrations levelled up significantly after 30 min or later (60 min) after the venom injection. Except for a probable pronounced oedema and few congestions in maternal lungs and degenerative aspects of trophoblast cells, all examined tissues showed a conserved structure. These results suggest that scorpion envenomation may induce gestation process disturbances and threatens both mother's and fetus’ well-being. 相似文献
125.
126.
Tarek Mohey El-Gammacy Noha Refaat Mohamed Amany Rasmy Al-Halag 《Scandinavian journal of clinical and laboratory investigation》2013,73(5):352-357
AbstractPreterm neonates with respiratory distress syndrome (RDS) are at increased risk of acute kidney injury (AKI). Our study aimed at determining whether serum cystatin C (sCysC) on day 3 of life (D3) can early predict AKI in preterm neonates with RDS. This prospective study was conducted on 75 preterm neonates; 50 with RDS and 25 without RDS. On D3, sCysC, serum creatinine (sCr) and blood urea nitrogen (BUN) were measured and estimated glomerular filtration rate (eGFR) was calculated. sCr and BUN levels were measured again on days 5 and 7. Neonates were evaluated for development of AKI during first week of life according to the modified pediatric RIFLE (pRIFLE) criteria. Thirteen neonates with RDS developed AKI (26%).There was no significant difference between RDS and control groups with respect to sCysC. RDS neonates with AKI had significantly higher sCysC than those without AKI (1.62?±?0.12 versus 1.16?±?0.09?mg/l; p?<?.001). RDS grade III–IV neonates had significantly higher sCysC than RDS grade I–II. There was a significant positive correlation between D3 sCysC and (D5 and D7 sCr and BUN). Receiver operating characteristic (ROC) curve showed that D3 sCysC can predict AKI in preterm neonates with RDS at a cutoff point of >1.3?mg/l with sensitivity of 92.30% and specificity of 96%. We conclude that neonates with RDS are at increased risk of AKI. sCysC on day 3 of life can predict AKI earlier than Cr and eGFR. 相似文献
127.
128.
Daniela Berg MD Jonathan D. Steinberger MD C. Warren Olanow MD Thomas P. Naidich MD Tarek A. Yousry MD 《Movement disorders》2011,26(6):979-992
Twenty‐five years ago, when this journal was initiated, imaging of movement disorders was in its infancy. Since that time, magnetic resonance imaging has become a standard technique that is routinely performed in patients with movement disorders in order to exclude secondary causes and in some instances to provide specific information that aids in making the diagnosis of a neurodegenerative condition. Transcranial sonography is a more recent advance and is now widely employed to aid in the diagnosis of Parkinson's disease and possibly in detecting individuals in the premotor phases of the disease. Investigations are currently under way to evaluate the value of this technique in other movement disorders. © 2011 Movement Disorder Society 相似文献
129.
130.
Danielle Boller Alexander Schramm Kathrin T Doepfner Tarek Shalaby André O von Bueren Angelika Eggert Michael A Grotzer Alexandre Arcaro 《Clinical cancer research》2008,14(4):1172-1181
PURPOSE: The phosphoinositide 3-kinase (PI3K)/Akt pathway is frequently activated in human cancer and plays a crucial role in neuroblastoma biology. We were interested in gaining further insight into the potential of targeting PI3K/Akt signaling as a novel antiproliferative approach in neuroblastoma. EXPERIMENTAL DESIGN: The expression pattern and functions of class I(A) PI3K isoforms were investigated in tumor samples and cell lines. Effects on cell survival and downstream signaling were analyzed following down-regulation of p110alpha or p110delta in SH-SY5Y and LA-N-1 cells by means of RNA interference. RESULTS: Overexpression of the catalytic p110delta and regulatory p85alpha isoforms was detected in a panel of primary neuroblastoma samples and cell lines, compared with normal adrenal gland tissue. Although down-regulation of either p110alpha or p110delta led to impaired cell growth, reduced expression of p110delta also had a selective effect on the survival of SH-SY5Y cells. Decreased levels of p110delta were found to induce apoptosis and lead to lower expression levels of antiapoptotic Bcl-2 family proteins. SH-SY5Y cells with decreased p110delta levels also displayed reduced activation of ribosomal protein S6 kinase in response to stimulation with epidermal growth factor and insulin-like growth factor-I. CONCLUSIONS: Together, our data reveal a novel function of p110delta in neuroblastoma growth and survival. 相似文献