全文获取类型
收费全文 | 2691篇 |
免费 | 160篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 43篇 |
妇产科学 | 124篇 |
基础医学 | 255篇 |
口腔科学 | 117篇 |
临床医学 | 215篇 |
内科学 | 691篇 |
皮肤病学 | 67篇 |
神经病学 | 147篇 |
特种医学 | 87篇 |
外国民族医学 | 3篇 |
外科学 | 481篇 |
综合类 | 54篇 |
预防医学 | 113篇 |
眼科学 | 73篇 |
药学 | 258篇 |
中国医学 | 13篇 |
肿瘤学 | 120篇 |
出版年
2023年 | 38篇 |
2022年 | 85篇 |
2021年 | 170篇 |
2020年 | 84篇 |
2019年 | 119篇 |
2018年 | 153篇 |
2017年 | 98篇 |
2016年 | 86篇 |
2015年 | 71篇 |
2014年 | 123篇 |
2013年 | 198篇 |
2012年 | 211篇 |
2011年 | 222篇 |
2010年 | 114篇 |
2009年 | 104篇 |
2008年 | 139篇 |
2007年 | 147篇 |
2006年 | 114篇 |
2005年 | 137篇 |
2004年 | 105篇 |
2003年 | 82篇 |
2002年 | 75篇 |
2001年 | 15篇 |
2000年 | 16篇 |
1998年 | 11篇 |
1997年 | 7篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1977年 | 3篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 3篇 |
1971年 | 4篇 |
1970年 | 3篇 |
1969年 | 5篇 |
1968年 | 6篇 |
1966年 | 3篇 |
排序方式: 共有2873条查询结果,搜索用时 46 毫秒
71.
72.
Case of acute lymphoblastic leukemia presenting with t(14;18)/BCL2, t(8;14)/cMYC, and t(1;2)/FCGR2B 总被引:3,自引:0,他引:3
The majority of follicular lymphoma and Burkitt's lymphoma are associated with reciprocal translocations involving BCL2 and cMYC, respectively. Unusual reports of aggressive lymphoma presenting with both translocations have been described as well as rare cases with a third structural alteration usually involving BCL6. The patient described here presented with aggressive high-grade lymphocytic leukemia, FAB subtype L2 (ALL-L2), and three reciprocal translocations, t(14;18)(q32;q21), t(8;14)(q24.1;q32), and t(1;2) (q22-23;p13). Despite immature morphology the leukemic blasts had a mature B-cell phenotype; they were positive for surface immunoglobulin heavy chains and negative for CD34, TdT, and CD10. Most reported dual t(14;18)/t(8;14) cases have not shown sIg and were positive for CD10. Molecular genetic analyses showed the typical rearrangements of BCL2 and cMYC as well as the FCGR2B gene on chromosome 1q23. The occurrence of a third oncogene rearrangement in association with the dual BCL2, cMYC translocations in ALL patients is very rare. To our knowledge, this is the first case where the third hit involves the FCGR2B locus. This report reiterates the poor prognosis associated with activation of cMYC together with elevated Bcl-2 expression. These data also support recent evidence that dysregulation of FCGR2B may play a role in tumor progression. 相似文献
73.
In this article, myocardial perfusion in patients with a totally occluded left anterior descending artery reinjected by a normal right coronary artery is assessed using stress single photon emission computed tomography (SPECT). In all, 20 patients, with a totally occluded left anterior descending artery reinjected by normal right coronary artery, underwent myocardial single photon emission computed tomography imaging within 60 days of angiography. All patients had abnormal perfusion single photon emission computed tomography results and 70% had reversible defects. Perfusion defects at rest were present in 75% of patients, with perinecrotic residual ischemia in 45% of patients whereas for 30% of patients, no viable myocardium was detected in the collateral-dependent segments. In all, 25% of patients had no resting perfusion defects but all are presented with stress-induced ischemia. Collaterals are not protective against stress-induced ischemia, but they can preserve myocardial viability. This conclusion is highly supported by the presence of residual ischemia in the collateral-dependent segments. 相似文献
74.
Comparison of Crestal Bone Loss Around Dental Implants Placed in Healed Sites Using Flapped and Flapless Techniques: A Systematic Review
下载免费PDF全文
![点击此处可从《Journal of periodontology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Fahim Vohra Abdulaziz A. Al‐Kheraif Khalid Almas Fawad Javed 《Journal of periodontology》2015,86(2):185-191
Background : The aim of the present systematic review is to compare the crestal bone loss (CBL) around dental implants placed in healed sites using flapped and flapless surgical techniques. Methods: The focused question was, “Does flapped and flapless surgical technique influence CBL around dental implants placed in healed sites?” Databases were searched from 1975 up to and including May 2014 using different combinations of the following keywords: “crestal bone loss”; “dental implant”; “surgery”; “flap”; and “flapless.” Unpublished data, experimental studies, letters to the editor, review articles, case reports, commentaries, and articles published in languages other than English were excluded. In all studies, the test group comprised implants placed using flapless surgery, and the control group, implants placed after reflection of a full‐thickness mucoperiosteal flap. Results: Ten clinical studies were included. In five studies, CBL around implants was comparable between the test and control groups. In four studies, implants in the test group showed significantly less CBL compared with the control group. In one study, CBL was significantly higher in the test group than the control group. Conclusion: CBL around dental implants placed in healed sites using flapped and flapless techniques is comparable. 相似文献
75.
76.
Fatma M Ghoneim Hanaa A Khalaf Ayman Z Elsamanoudy Salwa M Abo El-khair Ahmed MN Helaly El-Hassanin M Mahmoud Saad H Elshafey 《International journal of clinical and experimental pathology》2015,8(7):7710-7728
Alzheimer’s disease (AD) is a neurodegenerative disorder with progressive degeneration of the hippocampal and cortical neurons. This study was designed to demonstrate the protective effect of caffeine on gene expression of brain derived neurotrophic factor (BDNF) and its receptor neural receptor protein-tyrosine kinase-β (TrkB) as well as glial fibrillary acidic protein (GFAP) and Ki-67 immunoreactivity in Aluminum chloride (AlCl3) induced animal model of AD. Fifty adult rats included in this study were classified into 5 group (10 rats each); negative and positive control groups (I&II), AD model group (III), group treated with caffeine from the start of AD induction (IV) and group treated with caffeine two weeks before AD induction (V). Hippocampal tissue BDNF and its receptor (TrkB) gene expression by real time RT-PCR in addition to immunohistochemical study of GFAP and Ki67 immunoreactivity were performed for all rats in the study. The results of this study revealed that caffeine has protective effect through improving the histological and immunohistochemical findings induced by AlCl3 as well as BDNF and its receptor gene expression. It could be concluded from the current study, that chronic caffeine consumption in a dose of 1.5 mg/kg body weight daily has a potentially good protective effect against AD. 相似文献
77.
Risk factors for hospital admission among COVID-19 patients with diabetes: A study from Saudi Arabia
Ayman A. Al Hayek Asirvatham A. Robert Abdullah Bin Matar Ali Algarni Haneen Alkubedan Turki Alharbi Afrah Al Amro Seham A. Alrashidi Mohamed Al Dawish 《Saudi medical journal》2020,41(10):1090
Objectives:To elucidate the risk factors for hospital admission among COVID-19 patients with type 2 diabetes mellitus (T2DM).Methods:This retrospective study was conducted at the Prince Sultan Military Medical City, Riyadh, Saudi Arabia between May 2020 and July 2020. Out of 7,260 COVID-19 patients, 920 were identified as T2DM. After the exclusion process, 806 patients with T2DM were included in this analysis. Patients’ data were extracted from electronic medical records. A logistic regression model was performed to estimate the risk factors of hospital admission.Results:Of the total of 806 COVID-19 patients with T2DM, 48% were admitted in the hospital, 52% were placed under home isolation. Older age between 70-79 years (OR [odd ratio] 2.56; p=0.017), ≥80 years (OR 6.48; p=0.001) were significantly more likely to be hospitalized compared to <40 years. Similarly, patients with higher HbA1c level of ≥9% compared to <7%; (OR 1.58; p=0.047); patients with comorbidities such as, hypertension (OR 1.43; p=0.048), cardiovascular disease (OR 1.56; p=0.033), cerebrovascular disease (OR 2.38; p=0.016), chronic pulmonary disease (OR 1.51; p=0.018), malignancy (OR 2.45; p=0.025), chronic kidney disease (CKD) IIIa, IIIb, IV (OR 2.37; p=0.008), CKD V (OR 5.07; p=0.007) were significantly more likely to be hospitalized. Likewise, insulin-treated (OR 1.46; p=0.03) were more likely to require hospital admission compared to non-insulin treated patients.Conclusion:Among COVID-19 patients with diabetes, higher age, high HbA1c level, and presence of other comorbidities were found to be significant risk factors for the hospital admission. 相似文献
78.
Ayman El Nakeeb Emad Hamdy Ahmad M Sultan Tarek Salah Waleed Askr Helmy Ezzat Mohamed Said Mostaffa Abu Zeied Tallat Abdallah 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2014,16(8):713-722
Objectives
The optimal strategy for the reconstruction of the pancreas following pancreaticoduodenectomy (PD) is still debated. The aim of this study was to compare the outcomes of isolated Roux loop pancreaticojejunostomy (IRPJ) with those of pancreaticogastrostomy (PG) after PD.Methods
Consecutive patients submitted to PD were randomized to either method of reconstruction. The primary outcome measure was the rate of postoperative pancreatic fistula (POPF). Secondary outcomes included operative time, day to resumption of oral feeding, postoperative morbidity and mortality, and exocrine and endocrine pancreatic functions.Results
Ninety patients treated by PD were included in the study. The median total operative time was significantly longer in the IRPJ group (320 min versus 300 min; P = 0.047). Postoperative pancreatic fistula developed in nine of 45 patients in the IRPJ group and 10 of 45 patients in the PG group (P = 0.796). Seven IRPJ patients and four PG patients had POPF of type B or C (P = 0.710). Time to resumption of oral feeding was shorter in the IRPJ group (P = 0.03). Steatorrhea at 1 year was reported in nine of 42 IRPJ patients and 18 of 41 PG patients (P = 0.029). Albumin levels at 1 year were 3.6 g/dl in the IRPJ group and 3.3 g/dl in the PG group (P = 0.001).Conclusions
Isolated Roux loop PJ was not associated with a lower rate of POPF, but was associated with a decrease in the incidence of postoperative steatorrhea. The technique allowed for early oral feeding and the maintenance of oral feeding even if POPF developed. 相似文献79.
Divyang Patel Kevin M. Trulock Laurie Ann Moennich Erich L. Kiehl Anirudh Kumar Saleem Toro Eoin Donnellan Adam Grimaldi Bryan Baranowski Ayman A. Hussein Khaldoun G. Tarakji Daniel J. Cantillon Mark Niebauer Oussama M. Wazni Niraj Varma Bruce L. Wilkoff John W. Rickard 《Journal of cardiovascular electrophysiology》2020,31(5):1182-1186
80.