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   3696篇
  免费   219篇
  国内免费   36篇
耳鼻咽喉   67篇
儿科学   110篇
妇产科学   114篇
基础医学   457篇
口腔科学   121篇
临床医学   286篇
内科学   643篇
皮肤病学   82篇
神经病学   204篇
特种医学   176篇
外国民族医学   3篇
外科学   590篇
综合类   153篇
一般理论   3篇
预防医学   187篇
眼科学   173篇
药学   373篇
中国医学   16篇
肿瘤学   193篇
  2023年   42篇
  2022年   104篇
  2021年   191篇
  2020年   88篇
  2019年   109篇
  2018年   176篇
  2017年   84篇
  2016年   110篇
  2015年   124篇
  2014年   130篇
  2013年   175篇
  2012年   232篇
  2011年   237篇
  2010年   146篇
  2009年   146篇
  2008年   172篇
  2007年   162篇
  2006年   172篇
  2005年   141篇
  2004年   148篇
  2003年   138篇
  2002年   125篇
  2001年   62篇
  2000年   59篇
  1999年   57篇
  1998年   46篇
  1997年   42篇
  1996年   37篇
  1995年   39篇
  1994年   22篇
  1993年   14篇
  1992年   42篇
  1991年   34篇
  1990年   30篇
  1989年   33篇
  1988年   37篇
  1987年   19篇
  1986年   17篇
  1985年   17篇
  1984年   14篇
  1982年   16篇
  1981年   13篇
  1980年   14篇
  1979年   14篇
  1978年   11篇
  1977年   17篇
  1976年   13篇
  1975年   10篇
  1974年   12篇
  1969年   7篇
排序方式: 共有3951条查询结果,搜索用时 15 毫秒
51.
52.
53.

Purpose

Assessing the frequency and evaluating the efficacy and safety of Neodymium:Yttrium Aluminum Garnet (Nd:YAG) Laser goniopuncture (LGP) following nonpenetrating deep sclerectomy (NPDS).

Design

Retrospective cohort study.

Patients and methods

We retrospectively reviewed the outcome of 197 eyes of 153 patients with open angle glaucoma who underwent either NPDS or NPDS combined with cataract extraction between January 2005 and September 2010 at King Abdulaziz University Hospital (KAUH). Both demographic and clinical data were retrieved and analysed.

Results

Goniopuncture (GP) was needed in 48 (24.4%) of the eyes which had NPDS or NPDS with cataract extraction after a mean post operative interval of 9.78 (±11.16) months. The mean IOP had significantly decreased from 23.3 (±5.9) mmHg prior to Nd:YAG LGP procedure to 14.6 (±4.4) mmHg at the last post-procedure assessment. At the last follow-up; Nd:YAG LGP was successful in controlling IOP in 27 eyes (56.3%). Mean Nd:YAG LGP failure time was 6.04 (±5.80) months. Young age (<50 years) (p = 0.001); type of glaucoma (secondary versus primary open angle, p = 0.0258) and the use of drainage implant (p = 0.038) were the identified predicting factors for the need of Nd:YAG LGP. Complications following Nd:YAG LGP occurred in 5 eyes (iris touch to TDM (4.2%), Hyphema (2.1%), hypotony maculopathy (2.1%) and choroidal detachment (2.1%).

Conclusions

LGP is an efficient IOP lowering procedure after NPDS, when it is indicated. It is a simple and noninvasive procedure. However, certain precautions should be taken to avoid complications.  相似文献   
54.
55.
Saleh F  Reno W 《Neoplasma》2008,55(3):246-255
Patients with breast carcinomas of the invasive cribriform (IC) histological type often have excellent prognosis. Nevertheless, prognostic markers such as CD44v3, v4, and v6 isoforms have never been evaluated in this histological type. Cases seen between 1996 and 2006 at two major public hospitals in Kuwait were reviewed. We selected the cases which still had enough tissue in the paraffin blocks, had pure rather than mixed typical histological type, did not receive hormonal or any other type of therapy prior to or at the time the tumor was excised, and which were grade 1, and stage IIA (T2, N0, M0). This is to control for confounding factors that could affect the degree of tumor expression of the above isoforms. Sections were immunostained using a highly sensitive roxidase-anti-peroxidase kit, and scoring of immunostaining was performed in a semi-quantitative manner as established in the literature. An extensive expression of the CD44v3 and v6 isoforms was seen in 83.3% of the IC tumours, while 83.3% lacked the expression of the v4 isoform. A significant association between the histological type and degree of expression of CD44 isoforms was found only with the v3 isoform. The degree of expression of the v3 isoform was significantly different in the IC tumors as compared to the papillary, invasive lobular, and invasive ductal (NOS) ones. There was a significant negative correlation (rs= - 0.201) between the expression of the v4 and v6 isoforms. IC tumors seem to have a strong expression of the prognostic markers v3 and v6 isoforms of the transmembrane molecule CD44, and to lack the expression of the v4 isoform.  相似文献   
56.
57.
Tumor localization is challenging in the context of ductal carcinoma in situ (DCIS) treated with breast-conserving surgery. Conventional localization methods are generally performed under the guidance of ultrasonography or mammography and are rarely performed with magnetic resonance imaging (MRI), which is more sensitive than the aforementioned modalities in detecting DCIS. Here, we report the application of MRI-based individualized 3-dimensional (3D)-printed breast surgical guides (BSGs) for patients with breast cancer. We successfully resected indeterminate and suspicious lesions that were only detected using preoperative MRI, and the final histopathologic results confirmed DCIS with clear resection margins. MRI guidance combined with 3D-printed BSGs can be used for DCIS localization, especially for lesions easily detectable using MRI only.  相似文献   
58.
Aging is an unavoidable fate that afflicts all life, during this process in mammals reactive oxygen species (ROS) are generated which stimulate tyrosinase, elastase and collagenase activities that actively participate in skin aging. Therefore, the maintenance of antioxidant homeostasis is an important anti-aging strategy for skin. Nature has excellent anti-aging remedies that act externally as well as internally to delay the visual signs of aging. In view of this fact, the present study investigates the in vitro anti-aging activity of five medicinal plants belonging to phenolic rich families namely Rosmarinus officinalis, Lavandula officinalis, Matricaria chamomilla, Camellia sinensis and Pelargonium graveolens. The selected plants are those most frequently used in the preparation of ethnomedicinal recipes for the prevention or treatment of aging. The inhibitory effects of the ethanolic and aqueous extracts of the five selected plants on the activity of tyrosinase, elastase, and collagenase enzymes were investigated. Furthermore, the chemical composition of the plants and the antioxidant capacity of their extracts were assessed. The results showed that R. officinalis had the highest total phenolics content which was correlated with its potent antioxidant and anti-aging activities. To pinpoint the active metabolites in the tested extracts, we evaluated the metabolite variations using ultra-performance liquid chromatography coupled with high resolution electrospray ionization-tandem mass spectrometry (UPLC-HR-ESI-MS/MS). Multivariate data analysis (MVDA) revealed that R. officinalis significantly accumulated metabolites from the aromatic diterpenoid, flavonoid and phenolic acid classes. These results indicate that rosemary can be used for further development of topical preparations with anti-aging properties.

Aging is an unavoidable fate that afflicts all life, during this process in mammals, reactive oxygen species (ROS) are generated which stimulate tyrosinase, elastase and collagenase activities that actively participate in skin aging.  相似文献   
59.
The International Journal of Cardiovascular Imaging - Abnormal atrial mechanics in biventricular circulations have been associated with elevated left heart filling pressures. Similar associations...  相似文献   
60.
Automated Implantable Cardioverter Defibrillators (AICD), simply known as an Implantable Cardioverter Defibrillator (ICD), has been used in patients for more than 30 years. An Implantable Cardioverter Defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at a risk of sudden cardiac death due to ventricular fibrillation, ventricular tachycardia or any such related event. Typically, patients with these types of occurrences are on anticoagulant therapy. The desired International Normalized Ratio (INR) for these patients is in the range of 2–3 to prevent any subsequent cardiac event. These patients possess a challenge to the dentist in many ways, especially during oral surgical procedures, and these challenges include risk of sudden death, control of post-operative bleeding and pain.This article presents the dental management of a 60 year-old person with an ICD and concomitant anticoagulant therapy. The patient was on multiple medications and was treated for a grossly neglected mouth with multiple carious root stumps. This case report outlines the important issues in managing patients fitted with an ICD device and at a risk of sudden cardiac death.  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