全文获取类型
收费全文 | 711877篇 |
免费 | 34915篇 |
国内免费 | 614篇 |
专业分类
耳鼻咽喉 | 8307篇 |
儿科学 | 24086篇 |
妇产科学 | 16925篇 |
基础医学 | 105669篇 |
口腔科学 | 16130篇 |
临床医学 | 57798篇 |
内科学 | 128889篇 |
皮肤病学 | 12985篇 |
神经病学 | 54205篇 |
特种医学 | 28257篇 |
外国民族医学 | 63篇 |
外科学 | 111228篇 |
综合类 | 11264篇 |
一般理论 | 118篇 |
预防医学 | 58501篇 |
眼科学 | 14973篇 |
药学 | 50884篇 |
中国医学 | 1639篇 |
肿瘤学 | 45485篇 |
出版年
2018年 | 28374篇 |
2017年 | 22493篇 |
2016年 | 26259篇 |
2015年 | 5517篇 |
2014年 | 6912篇 |
2013年 | 10340篇 |
2012年 | 20001篇 |
2011年 | 36532篇 |
2010年 | 27930篇 |
2009年 | 20305篇 |
2008年 | 35593篇 |
2007年 | 40097篇 |
2006年 | 15462篇 |
2005年 | 17121篇 |
2004年 | 18544篇 |
2003年 | 19722篇 |
2002年 | 17246篇 |
2001年 | 24524篇 |
2000年 | 25844篇 |
1999年 | 20837篇 |
1998年 | 5720篇 |
1997年 | 5073篇 |
1996年 | 5231篇 |
1995年 | 4811篇 |
1994年 | 4531篇 |
1992年 | 15870篇 |
1991年 | 16489篇 |
1990年 | 16607篇 |
1989年 | 15941篇 |
1988年 | 14702篇 |
1987年 | 14552篇 |
1986年 | 13704篇 |
1985年 | 13092篇 |
1984年 | 9704篇 |
1983年 | 8325篇 |
1982年 | 4661篇 |
1979年 | 9520篇 |
1978年 | 6925篇 |
1977年 | 5791篇 |
1976年 | 5676篇 |
1975年 | 6401篇 |
1974年 | 7674篇 |
1973年 | 7138篇 |
1972年 | 6960篇 |
1971年 | 6685篇 |
1970年 | 6206篇 |
1969年 | 5932篇 |
1968年 | 5590篇 |
1967年 | 5012篇 |
1966年 | 4452篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
C. Banella M. Ginevrino G. Catalano E. Fabiani G. Falconi M. Divona P. Curzi P. Panetta M.T. Voso N.I. Noguera 《Hematology/oncology and stem cell therapy》2021,14(2):163-168
FGFR–TACC, found in different tumor types, is characterized by the fusion of a member of fibroblast grown factor receptor (FGFR) tyrosine kinase (TK) family to a member of the transforming acidic coiled-coil (TACC) proteins. Because chromosome numerical alterations, hallmarks of FGFR–TACC fusions are present in many hematological disorders and there are no data on the prevalence, we studied a series of patients with acute myeloid leukemia and myelodysplastic syndrome who presented numerical alterations using cytogenetic traditional analysis. None of the analyzed samples showed FGFR3–TACC3 gene fusion, so screening for this mutation at diagnosis is not recommended. 相似文献
72.
73.
Objective:To study the effect of oral administration of dimethyl dimethoxy biphenyl dicarboxylate(DDB) on adjusting angiogeneic/inflammatory mediators and ameliorating the pathology of bones in rats with collagen-induced arthritis(CIA).Methods:Wistar rat model of CIA was set up using bovine collagen type Ⅱ.Fifty rats were divided into five groups randomly:normal,CIA model,DDB treatment,methotrexate(MTX) treatment,and combined DDB+MTX treatment.Ankle joints of rats were imaged with digital X-ray machine to show the destruction of joints.Fore and hind paw and knee joints were removed above the ankle joint then processed for haematoxylin and eosin staining.Plasma levels of vascular endothelial growth factor(VEGF),platelet derived growth factor,interleukin-8(IL-8),IL-4,tumor necrosis factor α(TNF-α),and cyclooxygenase-2(COX-2) were quantified by enzyme-linked immunosorbent assay.Nitric oxide levels were detected by Griess reagent.Results:Compared with the CIA model group,a remarkable reduction in various angiogenic(VEGF and IL-8) and inflammatory mediators(TNF-α,IL-4 and COX-2) after treatment with DDB either alone or combined with MTX(P0.05 or P0.01).Histopathological and X-ray findings were confirmatory to the observed DDB anti-arthritic effect.The DDB-treated group showed amelioration in signs of arthritis which appeared essentially similar to normal.Conclusion:Our data shed light on the therapeutic efficacy of DDB in experimental rheumatoid arthritis(RA) compared with a choice drug(MTX) and it may be offered as a second-line drug in the treatment of RA. 相似文献
74.
Contraceptive use is an important strategy for the prevention of unwanted pregnancy and avoidance of induced abortion. Of all the contraception methods, emergency contraceptive (EC) offers the last chance to achieve this. However, few studies have documented the use of EC among young people in Ghana. This study explored knowledge and usage of EC as well as the factors associated with it among University of Cape Coast students. Data were obtained on the knowledge and usage of ECs among University of Cape Coast students in 2013. Logistic regression analysis was used to investigate the association between students’ socio-demographic characteristics and EC knowledge and use. More male students (72 %) than females (59 %) were sexually active. Fifty-seven percent of the respondents had ever heard of EC and 36 % had ever used EC. Although males were more likely to be sexually active, females were more likely to have knowledge of EC use compared to males. The study underscores the need to increase awareness regarding EC among University students in order to offer them the opportunity that EC provides if other forms of contraceptives are missed. 相似文献
75.
D. Panigrahy P. K. Sahu 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):783-795
Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal. These parameters are used by the EKS for the development of the state equation and also for initialization of the parameters of EKS. EKS framework is used for denoising the ECG signal from the single channel. The effectiveness of proposed noise cancellation technique has been evaluated by adding white, colored Gaussian noise and real muscle artifact noise at different SNR to some visually clean ECG signals from the MIT-BIH arrhythmia database. The proposed noise cancellation technique of ECG signal shows better signal to noise ratio (SNR) improvement, lesser mean square error (MSE) and percent of distortion (PRD) compared to other well-known methods. 相似文献
76.
77.
78.
79.
80.
Gastroesophageal reflux is the most common benign disorder of the esophagus and laparoscopic Nissen fundoplication has become the standard surgical treatment for its treatment. In our area, where the use of bougie calibration is debatable, postoperative dysphagia is encountered often after this surgery although it is usually not permanent. The aim of this study was to investigate the effect of using a soft silicone tube 39 F in diameter for esophageal calibration during laparoscopic Nissen fundoplication on the incidence of postoperative dysphagia. We divided cases scheduled to undergo laparoscopic Nissen fundoplication between January 2009 and November 2010 into two groups, each consisting 25 patients. Esophageal calibration with a 39 F silicone orogastric tube was used for the first group while there was no operative calibration in the second group. The surgical duration was recorded; the presence and severity of the postoperative dysphagia was calculated by using a dysphagia severity scoring system during the 1-year postoperative follow-up. The dysphagia severity scores were significantly lower in group 1 than group 2 on the postoperative second day and at the end of the first week and first month. We did not find a significant difference at the end of the 6-month and first year. There was also no significant difference regarding surgery duration. The use of a soft orogastric tube 39 F in diameter for esophagus calibration during laparoscopic Nissen fundoplication has significantly decreased the incidence of postoperative transient dysphagia without affecting the duration of surgery. Although dysphagia gradually resolves in the majority of patients, a safe and easy calibration method for its prevention is worth developing, and we believe that the use of our method in larger series could be beneficial. 相似文献