全文获取类型
收费全文 | 5318篇 |
免费 | 317篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 244篇 |
妇产科学 | 88篇 |
基础医学 | 650篇 |
口腔科学 | 330篇 |
临床医学 | 347篇 |
内科学 | 720篇 |
皮肤病学 | 79篇 |
神经病学 | 359篇 |
特种医学 | 91篇 |
外科学 | 898篇 |
综合类 | 93篇 |
一般理论 | 4篇 |
预防医学 | 236篇 |
眼科学 | 262篇 |
药学 | 680篇 |
中国医学 | 43篇 |
肿瘤学 | 478篇 |
出版年
2023年 | 43篇 |
2022年 | 123篇 |
2021年 | 239篇 |
2020年 | 129篇 |
2019年 | 151篇 |
2018年 | 220篇 |
2017年 | 129篇 |
2016年 | 183篇 |
2015年 | 195篇 |
2014年 | 243篇 |
2013年 | 320篇 |
2012年 | 531篇 |
2011年 | 502篇 |
2010年 | 253篇 |
2009年 | 218篇 |
2008年 | 296篇 |
2007年 | 266篇 |
2006年 | 223篇 |
2005年 | 163篇 |
2004年 | 171篇 |
2003年 | 116篇 |
2002年 | 100篇 |
2001年 | 76篇 |
2000年 | 62篇 |
1999年 | 48篇 |
1998年 | 26篇 |
1997年 | 16篇 |
1996年 | 23篇 |
1995年 | 24篇 |
1994年 | 15篇 |
1993年 | 12篇 |
1992年 | 45篇 |
1991年 | 40篇 |
1990年 | 35篇 |
1989年 | 45篇 |
1988年 | 24篇 |
1987年 | 36篇 |
1986年 | 26篇 |
1985年 | 23篇 |
1984年 | 23篇 |
1983年 | 25篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1979年 | 15篇 |
1977年 | 17篇 |
1976年 | 14篇 |
1975年 | 14篇 |
1974年 | 25篇 |
1973年 | 14篇 |
1972年 | 11篇 |
排序方式: 共有5649条查询结果,搜索用时 31 毫秒
91.
Shivsharan
M. Mali Parag P. Chavan Yuvraj H. Navale Vikas B. Patil Bhaskar R. Sathe 《RSC advances》2018,8(20):11177
Herein, we focused on the one pot synthesis of ZnO nanoplates (NP edge thickness of ∼100 nm) using a chemical emulsion approach for chemical (direct) and electrochemical (indirect) determination of NO2. The structural and morphological elucidation of the as-synthesized ZnO NPs was carried out by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDAX), thermogravimetric analysis (TGA) and BET-surface area measurements. The XRD studies of the as-synthesised NPs reveal that ZnO NPs have a Wurtzite type crystal structure with a crystallite size of ∼100 nm. Such ZnO NPs were found to be highly sensitive to NO2 gas at an operating temperature of 200 °C. Electrocatalytic abilities of these ZnO NPs towards NO2/NO2− were verified through cyclic voltammetry (CV) and linear sweep voltammetry (LSV) using aqueous 1 mM NO2− (nitrite) in phosphate buffer (pH 7) solution. The results revealed enhanced activity at an onset potential of 0.60 V vs. RCE, achieved at a current density of 0.14 mA cm−2. These ZnO NPs show selective NO2 detection in the presence of other reactive species including CO, SO2, CH3OH and Cl2. These obtained results show that this chemical route is a low cost and promising method for ZnO NPs synthesis and recommend further exploration into its applicability towards tunable electrochemical as well as solid state gas sensing of other toxic gases.Herein, we focused on the one pot synthesis of ZnO nanoplates (NP edge thickness of ∼100 nm) using a chemical emulsion approach for chemical (direct) and electrochemical (indirect) determination of NO2. 相似文献
92.
Wenjun Kang Sabah Kadri Rutika Puranik Michelle N. Wurst Sushant A. Patil Ibro Mujacic Sonia Benhamed Nifang Niu Chao Jie Zhen Bekim Ameti Bradley C. Long Filipo Galbo David Montes Crystal Iracheta Venessa L. Gamboa Daisy Lopez Michael Yourshaw Carolyn A. Lawrence Jeremy P. Segal 《The Journal of molecular diagnostics : JMD》2018,20(4):522-532
93.
Patil S. L. Loganandhan N. Ramesha M. N. Adhikary Partha Pratim Channabasappa K. 《Proceedings of the National Academy of Sciences, India. Section B.》2018,88(2):685-694
Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - In-situ rainwater conservation improves chickpea productivity in Vertisols. This hypothesis was tested by... 相似文献
94.
Tumors of the Ocular Surface clinically manifest with a very wide spectrum and include several forms of epithelial, stromal, caruncular, and secondary tumors. As a group, these tumors are seen commonly in the clinical practice of a comprehensive ophthalmologist, cornea specialist, and an ocular oncologist. This review is aimed to discuss the common tumors of the ocular surface and emphasize on their clinical diagnosis and appropriate management. 相似文献
95.
96.
Graham Peigh MD Jeremiah Wasserlauf MD MS Kelly Vogel BS Rachel M. Kaplan MD MS Anna Pfenniger MD PhD Daniel Marks MD Arjun Mehta MD Alexandru B. Chicos MD Rishi Arora MD Susan Kim MD Albert Lin MD Nishant Verma MD MPH Kaustubha D. Patil MD Bradley P. Knight MD Rod S. Passman MD MSCE 《Journal of cardiovascular electrophysiology》2021,32(8):2097-2104
97.
Enes Elvin Gul MD Rajiv A. Kabadi MD Santosh K. Padala MD Paula Sanchez Somonte MD Jordana Kron MD Richard K. Shepard MD Jayanthi N. Koneru MD Gautham Kalahasty MD Maria Terricabras MD Bernice Tsang MD Yaariv Khaykin MD Zaev Wulffhart MD Alfredo Pantano MD Kenneth A. Ellenbogen MD Atul Verma MD 《Journal of cardiovascular electrophysiology》2021,32(9):2515-2521
98.
Summary 4-Methylphenylhydrazine hydrochloride was administered as 10 weekly subcutaneous injections of 140 g/g body weight and as 7 weekly intragastric instillations of 250 g/g body weight in physiological saline to randomly bred Swiss mice. Treatments given subcutaneously resulted in induction of lung tumors in incidences of 36% in females and 44% in males, while intragastric treatment caused a 40% incidence in females. In addition, it gave rise to blood vessel tumors by intragastric route in incidences of 32% in females and 18% in males. In the two physiological saline-treated control groups, the lung tumor incidence (combined) was 20% in females and 21% in males, while the blood vessel tumor incidence (combined) was 7% in females and 6% in males. Histopathologically, the lesions were classified as adenomas and adenocarcinomas of the lungs, and angiomas and angiosarcomas of blood vessels.4-Methylphenylhydrazine was postulated to be a metabolite of 4-hydroxymethylphenylhydrazine, an ingredient of the commonly eaten mushroom Agaricus bisporus. The implications are discussed with respect to the tumorigenesis data.This study was supported by Public Health Service Contract NOl CP33278 from the National Cancer Institute, NIH, USA 相似文献
99.
H L Komiskey J F Bossart D D Miller P N Patil 《Proceedings of the National Academy of Sciences of the United States of America》1978,75(6):2641-2643
Tritiated dopamine was used to label the dopamine receptor in membranes isolated from the rat corpus striatum. Scatchard analysis of displacement of [3H]dopamine by nonradioactive dopamine indicated the presence of two binding sites. The similarities in affinity, capacity, and drug specificity of the high-affinity site in the striatal membranes from rat and the binding site in the membranes from the calf caudate nucleus suggest that [3H]dopamine labels the same site in both species. In order to determine what conformation of dopamine is preferred at the dopamine receptor site, conformationally restricted analogs of dopamine--namely, the cis and trans 2-amino-1(3,4-dihydroxyphenyl)cyclobutane hydrochlorides--were tested for their affinity to the receptor. Compared to the cis conformation, the trans-restricted analogs had more affinity for the receptor site, indicating that dopamine probably interacts with the receptor in the trans conformation. 相似文献
100.
Janelle C. Waite Santosh Vardhana Patrick J. Shaw Jung‐Eun Jang Christie‐Ann McCarl Thomas O. Cameron Stefan Feske Michael L. Dustin 《European journal of immunology》2013,43(12):3343-3354
Entry of lymphocytes into secondary lymphoid organs (SLOs) involves intravascular arrest and intracellular calcium ion ([Ca2+]i) elevation. TCR activation triggers increased [Ca2+]i and can arrest T‐cell motility in vitro. However, the requirement for [Ca2+]i elevation in arresting T cells in vivo has not been tested. Here, we have manipulated the Ca2+ release‐activated Ca2+ (CRAC) channel pathway required for [Ca2+]i elevation in T cells through genetic deletion of stromal interaction molecule (STIM) 1 or by expression of a dominant‐negative ORAI1 channel subunit (ORAI1‐DN). Interestingly, the absence of CRAC did not interfere with homing of naïve CD4+ T cells to SLOs and only moderately reduced crawling speeds in vivo. T cells expressing ORAI1‐DN lacked TCR activation induced [Ca2+]i elevation, yet arrested motility similar to control T cells in vitro. In contrast, antigen‐specific ORAI1‐DN T cells had a twofold delayed onset of arrest following injection of OVA peptide in vivo. CRAC channel function is not required for homing to SLOs, but enhances spatiotemporal coordination of TCR signaling and motility arrest. 相似文献