全文获取类型
收费全文 | 8808篇 |
免费 | 670篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 112篇 |
儿科学 | 201篇 |
妇产科学 | 233篇 |
基础医学 | 1360篇 |
口腔科学 | 142篇 |
临床医学 | 816篇 |
内科学 | 1944篇 |
皮肤病学 | 121篇 |
神经病学 | 861篇 |
特种医学 | 307篇 |
外科学 | 1234篇 |
综合类 | 111篇 |
现状与发展 | 1篇 |
一般理论 | 14篇 |
预防医学 | 734篇 |
眼科学 | 229篇 |
药学 | 526篇 |
中国医学 | 8篇 |
肿瘤学 | 555篇 |
出版年
2023年 | 95篇 |
2022年 | 187篇 |
2021年 | 299篇 |
2020年 | 172篇 |
2019年 | 302篇 |
2018年 | 319篇 |
2017年 | 192篇 |
2016年 | 203篇 |
2015年 | 260篇 |
2014年 | 311篇 |
2013年 | 444篇 |
2012年 | 573篇 |
2011年 | 633篇 |
2010年 | 304篇 |
2009年 | 322篇 |
2008年 | 480篇 |
2007年 | 542篇 |
2006年 | 456篇 |
2005年 | 481篇 |
2004年 | 493篇 |
2003年 | 435篇 |
2002年 | 419篇 |
2001年 | 83篇 |
2000年 | 73篇 |
1999年 | 82篇 |
1998年 | 87篇 |
1997年 | 72篇 |
1996年 | 60篇 |
1995年 | 62篇 |
1994年 | 58篇 |
1993年 | 52篇 |
1992年 | 45篇 |
1991年 | 39篇 |
1990年 | 42篇 |
1989年 | 56篇 |
1988年 | 41篇 |
1987年 | 52篇 |
1986年 | 41篇 |
1985年 | 31篇 |
1984年 | 44篇 |
1983年 | 37篇 |
1982年 | 34篇 |
1981年 | 30篇 |
1979年 | 25篇 |
1978年 | 26篇 |
1977年 | 28篇 |
1976年 | 33篇 |
1974年 | 28篇 |
1973年 | 33篇 |
1972年 | 27篇 |
排序方式: 共有9509条查询结果,搜索用时 0 毫秒
101.
Eleftherios P Mamounas Ann Brown Stewart Anderson Roy Smith Thomas Julian Barbara Miller Harry D Bear Christopher B Caldwell Alonzo P Walker Wendy M Mikkelson Jay S Stauffer Andre Robidoux Heather Theoret Atilla Soran Atilla Sovan Bernard Fisher D Lawrence Wickerham Norman Wolmark 《Journal of clinical oncology》2005,23(12):2694-2702
PURPOSE: Experience with sentinel node biopsy (SNB) after neoadjuvant chemotherapy is limited. We examined the feasibility and accuracy of this procedure within a randomized trial in patients treated with neoadjuvant chemotherapy. PATIENTS AND METHODS: During the conduct of National Surgical Adjuvant Breast and Bowel Project trial B-27, several participating surgeons attempted SNB before the required axillary dissection in 428 patients. All underwent lymphatic mapping and an attempt to identify and remove a sentinel node. Lymphatic mapping was performed with radioactive colloid (14.7%), with lymphazurin blue dye alone (29.9%), or with both (54.7%). RESULTS: Success rate for the identification and removal of a sentinel node was 84.8%. Success rate increased significantly with the use of radioisotope (87.6% to 88.9%) versus with the use of lymphazurin alone (78.1%, P = .03). There were no significant differences in success rate according to clinical tumor size, clinical nodal status, age, or calendar year of random assignment. Of 343 patients who had SNB and axillary dissection, the sentinel nodes were positive in 125 patients and were the only positive nodes in 70 patients (56.0%). Of the 218 patients with negative sentinel nodes, nonsentinel nodes were positive in 15 (false-negative rate, 10.7%; 15 of 140 patients). There were no significant differences in false-negative rate according to clinical patient and tumor characteristics, method of lymphatic mapping, or breast tumor response to chemotherapy. CONCLUSION: These results are comparable to those obtained from multicenter studies evaluating SNB before systemic therapy and suggest that the sentinel node concept is applicable following neoadjuvant chemotherapy. 相似文献
102.
103.
104.
105.
目的:测定黄脚胡蜂的脂溶性成分的组成。方法:采用浸渍法提取脂溶性成分,并用气相色谱-质谱联用仪检测其化学成分。结果:从黄脚胡蜂脂溶性成分中鉴定了12个化合物,其主要成分为油酸乙酯(57.82%)、亚油酸乙酯(11.76%)、棕榈酸乙酯(8.32%)、苯乙醇(8.08%)、丁二酸二乙酯(3.48%)。结论:黄脚胡蜂的脂溶性成分中含量较高的亚油酸乙酯和棕榈酸乙酯具有抗炎的作用,这与云南民间将黄脚胡蜂用酒浸泡后用来治疗佐剂性关节炎和类风湿性关节炎相一致,为民间的用法提供了理论依据。 相似文献
106.
Association between CFH,CFB, ARMS2, SERPINF1, VEGFR1 and VEGF polymorphisms and anatomical and functional response to ranibizumab treatment in neovascular age‐related macular degeneration 下载免费PDF全文
107.
108.
Elena Garcia‐Martin Luis E. Pablo Raquel Herrero Jose R. Ara Jesus Martin Jose M. Larrosa Vicente Polo Julian Garcia‐Feijoo Javier Fernandez 《Acta ophthalmologica. Supplement》2013,91(8):e628-e634
Purpose: To compare axonal loss in ganglion cells detected with spectral‐domain optical coherence tomography (OCT) in eyes of patients with multiple sclerosis (MS) versus healthy control subjects using an artificial neural network (ANN). To analyse the capability of the ANN technique to improve the detection of retinal nerve fibre layer (RNFL) damage in patients with multiple sclerosis. Methods: Patients with multiple sclerosis (n = 106) and age‐matched healthy subjects (n = 115) were enrolled. The Spectralis OCT system was used to obtain the circumpapillary RNFL thickness in both eyes. The 768 RNFL thickness measurements provided by the Spectralis OCT were performed to obtain thickness measurements from 24 uniformly divided locations around the peripapillary RNFL. The performance of the ANN technique for identifying RNFL loss in patients with multiple sclerosis was evaluated. Receiver‐operating characteristic (ROC) curves were used to display the ability of the test to discriminate between MS and healthy eyes in our population. ROC curves obtained using ANN and parameters provided by OCT (mean and 6 sector thicknesses) were compared. Results: The capability of the ANN technique to detect RNFL loss in patients with multiple sclerosis compared with healthy subjects was good. The area under the ROC curve was 0.945. Compared with the OCT‐provided parameters, the ANN had the largest area under the ROC curve. Conclusions: Measurements of RNFL thickness obtained with Spectralis OCT have a good ability to differentiate between healthy and individuals with multiple sclerosis. Based on the area under the ROC curve, the ANN performed better than any single OCT parameter. 相似文献
109.
110.
Ajmal Zarinwall Viktor Maurer Jennifer Pierick Victor Marcus Oldhues Julian Cedric Porsiel Jan Henrik Finke Georg Garnweitner 《Drug delivery》2022,29(1):2086
Promising active pharmaceutical ingredients (APIs) often exhibit poor aqueous solubility and thus a low bioavailability that substantially limits their pharmaceutical application. Hence, efficient formulations are required for an effective translation into highly efficient drug products. One strategy is the preservation of an amorphous state of the API within a carrier matrix, which leads to enhanced dissolution. In this work, mesoporous silica aerogels (SA) were utilized as a carrier matrix for the amorphization of the poorly water-soluble model drug ibuprofen. Loading of tailored SA was performed post-synthetically and solvent-free, either by co-milling or via the melting method. Thorough analyses of these processes demonstrated the influence of macrostructural changes during the drying and grinding process on the microstructural properties of the SA. Furthermore, interfacial SA-drug interaction properties were selectively tuned by attaching terminal hydrophilic amino- or hydrophobic methyl groups to the surface of the gel. We demonstrate that not only the chemical surface properties of the SA, but also formulation-related parameters, such as the carrier-to-drug ratio, as well as process-related parameters, such as the drug loading method, decisively influence the ibuprofen adsorption efficiency. In addition, the drug-loaded SA formulations exhibited a remarkable physical stability over a period of 6 months. Furthermore, the release behavior is shown to change considerably with different surface properties of the SA matrix. Hence, the reported results demonstrate that utilizing specifically processed and modified SA offers a compelling technique for enhancement of the bioavailability of poorly-water soluble APIs and a versatile adjustment of their release profile. 相似文献