全文获取类型
收费全文 | 14859篇 |
免费 | 916篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 219篇 |
儿科学 | 441篇 |
妇产科学 | 237篇 |
基础医学 | 1663篇 |
口腔科学 | 410篇 |
临床医学 | 1246篇 |
内科学 | 3370篇 |
皮肤病学 | 327篇 |
神经病学 | 835篇 |
特种医学 | 463篇 |
外国民族医学 | 5篇 |
外科学 | 2244篇 |
综合类 | 390篇 |
一般理论 | 8篇 |
预防医学 | 990篇 |
眼科学 | 404篇 |
药学 | 1443篇 |
1篇 | |
中国医学 | 191篇 |
肿瘤学 | 961篇 |
出版年
2023年 | 170篇 |
2022年 | 510篇 |
2021年 | 734篇 |
2020年 | 432篇 |
2019年 | 605篇 |
2018年 | 689篇 |
2017年 | 422篇 |
2016年 | 547篇 |
2015年 | 531篇 |
2014年 | 683篇 |
2013年 | 827篇 |
2012年 | 1186篇 |
2011年 | 1201篇 |
2010年 | 756篇 |
2009年 | 536篇 |
2008年 | 797篇 |
2007年 | 774篇 |
2006年 | 680篇 |
2005年 | 626篇 |
2004年 | 519篇 |
2003年 | 409篇 |
2002年 | 388篇 |
2001年 | 204篇 |
2000年 | 188篇 |
1999年 | 176篇 |
1998年 | 78篇 |
1997年 | 48篇 |
1996年 | 47篇 |
1995年 | 48篇 |
1994年 | 51篇 |
1993年 | 49篇 |
1992年 | 72篇 |
1991年 | 88篇 |
1990年 | 82篇 |
1989年 | 80篇 |
1988年 | 50篇 |
1987年 | 63篇 |
1986年 | 51篇 |
1985年 | 44篇 |
1984年 | 40篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 29篇 |
1980年 | 26篇 |
1979年 | 43篇 |
1978年 | 27篇 |
1977年 | 22篇 |
1975年 | 28篇 |
1974年 | 23篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Fouad Damiri Swetha Andra Nagavendra Kommineni Satheesh Kumar Balu Raviteja Bulusu Amira A. Boseila Damilola O. Akamo Zubair Ahmad Farhat S. Khan Md. Habibur Rahman Mohammed Berrada Simona Cavalu 《Materials》2022,15(15)
Water contamination is one of the most urgent concerns confronting the world today. Heavy metal poisoning of aquatic systems has piqued the interest of various researchers due to the high toxicity and carcinogenic consequences it has on living organisms. Due to their exceptional attributes such as strong reactivity, huge surface area, and outstanding mechanical properties, nanomaterials are being produced and employed in water treatment. In this review, recent advances in the use of nanomaterials in nanoadsorptive membrane systems for wastewater treatment and heavy metal removal are extensively discussed. These materials include carbon-based nanostructures, metal nanoparticles, metal oxide nanoparticles, nanocomposites, and layered double hydroxide-based compounds. Furthermore, the relevant properties of the nanostructures and the implications on their performance for water treatment and contamination removal are highlighted. The hydrophilicity, pore size, skin thickness, porosity, and surface roughness of these nanostructures can help the water permeability of the nanoadsorptive membrane. Other properties such as surface charge modification and mechanical strength can improve the metal adsorption effectiveness of nanoadsorptive membranes during wastewater treatment. Various nanocomposite membrane fabrication techniques are also reviewed. This study is important because it gives important information on the roles of nanomaterials and nanostructures in heavy metal removal and wastewater treatment. 相似文献
62.
Hypophosphatemic rickets/osteomalacia in linear sebaceous nevus syndrome: a variant of tumor-induced osteomalacia 总被引:1,自引:0,他引:1
D E Carey M K Drezner J A Hamdan M Mange M S Ahmad S Mubarak W L Nyhan 《The Journal of pediatrics》1986,109(6):994-1000
A severe form of vitamin D-resistant rickets is associated with the linear sebaceous nevus syndrome. We investigated the pathophysiology underlying defective bone mineralization in two individuals and examined the effects of 1,25-dihydroxyvitamin D (1,25(OH)2D, calcitriol) therapy on the clinical and biochemical abnormalities. Both patients had fasting hypophosphatemia, markedly diminished TmP/GFR, and elevated alkaline phosphase activity in the presence of normocalcemia. Before treatment with calcitriol, serum 1,25(OH)2D concentrations were reduced but serum 25-hydroxyvitamin D (25(OH)D) concentrations were normal. Administration of calcitriol increased serum 1,25(OH)2D concentrations and led to an increase in TmP/GFR and serum phosphorus levels and to a decrease in alkaline phosphatase activity. However, the renal tubular maximum for reabsorption of inorganic phosphate, normalized according to glomerular filtration rate, and serum phosphorus levels remained abnormally low even in the patient who also received phosphate supplementation. Bone histomorphologic studies in the adult patient showed extreme osteomalacia, which partially improved with calcitriol. These data demonstrate that the putative skin lesion-derived factor results in both a renal tubular defect in phosphate reabsorption and in 1,25-(OH)2 D deficiency. The vitamin D-resistant rickets of linear sebaceous nevus syndrome is a variant of tumor-induced osteomalacia. 相似文献
63.
Purpose:This study aims to facilitate researchers’ and clinicians’ understanding of research frontiers and trends in nocturia. It explores the scientific research outcomes and key bibliometric indices and plots global research on nocturia.Methods:A bibliometric retrospective study was designed, and an online search was conducted in the Web of Science Core Collection database using the potential search keywords related to nocturia in the title field with some specific filtration. HistCite™ and VOSviewer software for windows were used to analyze the data obtained for authors, journals, countries, institutions, keywords, and visualization mapping.Results:The initial search retrieved 1479 hits. A total of 1445 publications were included in the final analysis. Of these, 43.53% were published as articles. The most studied area in nocturia is urology nephrology. The most productive year was 2019 (n = 121, citations = 335), and the most prolific author, both in terms of publications (n = 97) and citations (1658) was Weiss JP. The most cited journal in nocturia research was the Journal of Urology (n = 293, citations = 3050). The most widely used keyword in nocturia publications was nocturia (n = 1249). Visualization mapping shows that the USA was the most influential and highly cited country in nocturia research.Conclusion:This study showed that there has been an increasing research trend in nocturia over the past few years. The current findings provide important empirical evidence for researchers, clinicians, and physicians to understand research frontiers and trends, achievements, collaborative networks, and hotspot research topics in the research field of nocturia. 相似文献
64.
65.
66.
67.
68.
IntroductionThe glans penis is prone to mutilation in a handful of conditions, some accidental and others iatrogenic. Deformed functioning remnants of the glans challenge the surgeon's decision. Neither is the glans totally amputated, justifying a neoglansplasty, nor are the remnants cosmetically acceptable, though retaining sensibility and engorgement.AimIn this work, we described the “reconfiguration of the glans penis” whereby deformed glanular tissue remnants can be made into a functional and cosmetically acceptable glans.MethodsFive patients with separate mutilated lumps of functioning glanular tissue were operated upon. The lumps were mobilized and flattened into sheets and configured to redrape the summit of the penis, minding their vascular and nerve supply.Main Outcome MeasuresCosmetic and functional outcome.ResultsThe outcome was cosmetically acceptable for all patients in comparison to the preoperative state.ConclusionGlans reconfiguration may possibly confer an acceptable cosmetic outlook to a mutilated glans without compromising valuable functional characteristics. Shaeer O, El-Sebaie A, Sherif A, El-Sadat A, and Shaeer A. Glans reconfiguration for management of glanular mutilation. 相似文献
69.
Abdel Bar FM Zaghloul AM Bachawal SV Sylvester PW Ahmad KF El Sayed KA 《Journal of natural products》2008,71(10):1787-1790
Three new 28-norlupane triterpenes, 28-norlup-20(29)-en-3beta-hydroxy-17beta-hydroperoxide (1), 28-norlup-20(29)-en-3beta-hydroxy-17alpha-hydroperoxide (2), and 20 S-17beta,29-epoxy-28-norlupan-3beta-ol (3), were isolated from the leaves of Melaleuca ericifolia along with eight known pentacyclic triterpenes. The structures of the new compounds were elucidated by spectroscopic methods including 1D and 2D NMR spectroscopy and mass spectrometry. The isolated triterpenes were evaluated for antiproliferative activity against the malignant +SA mammary epithelial cell line. 相似文献
70.