全文获取类型
收费全文 | 21515篇 |
免费 | 1142篇 |
国内免费 | 553篇 |
专业分类
耳鼻咽喉 | 151篇 |
儿科学 | 338篇 |
妇产科学 | 136篇 |
基础医学 | 2040篇 |
口腔科学 | 178篇 |
临床医学 | 1311篇 |
内科学 | 2044篇 |
皮肤病学 | 152篇 |
神经病学 | 749篇 |
特种医学 | 497篇 |
外科学 | 3503篇 |
综合类 | 2915篇 |
一般理论 | 1篇 |
预防医学 | 1379篇 |
眼科学 | 67篇 |
药学 | 5991篇 |
10篇 | |
中国医学 | 1081篇 |
肿瘤学 | 667篇 |
出版年
2024年 | 37篇 |
2023年 | 323篇 |
2022年 | 785篇 |
2021年 | 845篇 |
2020年 | 644篇 |
2019年 | 611篇 |
2018年 | 569篇 |
2017年 | 573篇 |
2016年 | 591篇 |
2015年 | 649篇 |
2014年 | 1179篇 |
2013年 | 1190篇 |
2012年 | 1150篇 |
2011年 | 1271篇 |
2010年 | 988篇 |
2009年 | 931篇 |
2008年 | 933篇 |
2007年 | 988篇 |
2006年 | 879篇 |
2005年 | 807篇 |
2004年 | 676篇 |
2003年 | 574篇 |
2002年 | 494篇 |
2001年 | 434篇 |
2000年 | 404篇 |
1999年 | 342篇 |
1998年 | 295篇 |
1997年 | 263篇 |
1996年 | 229篇 |
1995年 | 246篇 |
1994年 | 256篇 |
1993年 | 218篇 |
1992年 | 231篇 |
1991年 | 237篇 |
1990年 | 224篇 |
1989年 | 194篇 |
1988年 | 211篇 |
1987年 | 176篇 |
1986年 | 151篇 |
1985年 | 178篇 |
1984年 | 172篇 |
1983年 | 135篇 |
1982年 | 174篇 |
1981年 | 150篇 |
1980年 | 153篇 |
1979年 | 114篇 |
1978年 | 89篇 |
1977年 | 71篇 |
1976年 | 49篇 |
1974年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Carolina Cefaliello Maria Eyman Dominique Melck Rosanna De Stefano Eugenia Ferrara Marianna Crispino Antonio Giuditta 《Journal of neuroscience research》2014,92(11):1573-1580
Synaptosomal protein synthesis from rat brain is selectively increased by learning and is massively enhanced during the recovery period from brain ischemia. To lay the groundwork for identification of the involved synaptic elements, we examined the effects induced by varying the concentrations of extracellular cations and endogenous calcium. Most of the recorded rate response curves exhibited biphasic profiles that suggested the presence of more than one translation system. Because comparable profiles were obtained by fully inhibiting mitochondrial translation, the data indicated the involvement of cytoplasmic translation systems present in different synaptosomal classes. Their properties may be individually investigated by exploiting the partially inhibited conditions we have described. The identification of the synaptic elements from which they originated and their newly synthesized proteins will significantly expand our understanding of the synaptic contribution to brain plastic events. © 2014 Wiley Periodicals, Inc. 相似文献
993.
陈忠明 《河南实用神经疾病杂志》2014,(1):13-15
目的 对血脂水平异常与脑出血发病的相关性进行研究.方法 对我院2010-01-2012-09的120例急性脑出血患者进行回顾性分析,并选取性别、年龄相仿的120例健康体检者,分别分为实验组和对照组.将2组患者入院时的血脂检测结果 进行对比分析.结果 (1)实验组TG、ApoB水平高于对照组,差异有统计学意义(P<0.05).(2)青壮年(<60岁)患者中,实验组TC、TG和ApoB水平明显高于对照组(P<0.05).(3)老年患者(>60岁)中实验组TG、LDL-C和ApoB水平均明显高于对照组(P<0.05),HDL-C、ApoA1水平则明显较对照组有所降低(P<0.05).结论 脑出血患者以TG、ApoB水平升高为主要变化,而不同年龄段脑出血患者血脂变化也有所不同,对临床有一定的辅助诊断价值. 相似文献
994.
995.
Mark R. Hopkins Abby M. Richmond Georgina Cheng Susan Davidson Monique A. Spillman Jeanelle Sheeder Miriam D. Post Saketh R. Guntupalli 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2014,18(3)
Background:
Minimally invasive surgery has become a standard treatment for endometrial cancer and offers significant benefits over abdominal approaches. There are discrepant data regarding lymphovascular space invasion (LVSI) and positive peritoneal cytology with the use of a uterine manipulator, with previous small-scale studies demonstrating an increased incidence of these prognostically important events. We sought to determine if there was a higher incidence of LVSI in patients who underwent robot-assisted surgery for endometrial cancer.Methods:
We performed a single-institution review of medical records for patients who underwent open abdominal or robot-assisted hysterectomy for endometrial cancer over a 24-month period. The following data were abstracted: age, tumor grade and stage, size, depth of invasion, LVSI, and peritoneal cytology. For patients with LVSI, slides were reviewed by 2 pathologists for confirmation of LVSI.Results:
Of 104 patients identified, LVSI was reported in 39 (37.5%) and positive peritoneal cytology in 6 (4.8%). Rates of peritoneal cytology were not significantly different between the 2 groups (odds ratio, 0.55; 95% confidence interval, 0.10–3.17; P = .50). LVSI was reported in significantly fewer robot-assisted hysterectomies than open procedures (odds ratio, 0.39; 95% confidence interval, 0.17–0.92; P = .03). In subgroup analyses restricted to early-stage disease (stage ≤ II), there was no significant difference in LVSI between open and robot-assisted hysterectomies (odds ratio, 0.64; 95% confidence interval, 0.22–1.85; P = .43).Conclusion:
In this retrospective study, we found that use of a uterine manipulator in robot-assisted surgery did not increase the incidence of LVSI. 相似文献996.
The objective of this study was to compare the short-term respiratory effects due to the inhalation of electronic and conventional tobacco cigarette-generated mainstream aerosols through the measurement of the exhaled nitric oxide (eNO). To this purpose, twenty-five smokers were asked to smoke a conventional cigarette and to vape an electronic cigarette (with and without nicotine), and an electronic cigarette without liquid (control session). 相似文献
997.
Julie K. Klint Géza Berecki Thomas Durek Mehdi Mobli Oliver Knapp Glenn F. King David J. Adams Paul F. Alewood Lachlan D. Rash 《Biochemical pharmacology》2014
Spider venoms are replete with peptidic ion channel modulators, often with novel subtype selectivity, making them a rich source of pharmacological tools and drug leads. In a search for subtype-selective blockers of voltage-gated calcium (CaV) channels, we isolated and characterized a novel 39-residue peptide, ω-TRTX-Cc1a (Cc1a), from the venom of the tarantula Citharischius crawshayi (now Pelinobius muticus). Cc1a is 67% identical to the spider toxin ω-TRTX-Hg1a, an inhibitor of CaV2.3 channels. We assembled Cc1a using a combination of Boc solid-phase peptide synthesis and native chemical ligation. Oxidative folding yielded two stable, slowly interconverting isomers. Cc1a preferentially inhibited Ba2+ currents (IBa) mediated by L-type (CaV1.2 and CaV1.3) CaV channels heterologously expressed in Xenopus oocytes, with half-maximal inhibitory concentration (IC50) values of 825 nM and 2.24 μM, respectively. In rat dorsal root ganglion neurons, Cc1a inhibited IBa mediated by high voltage-activated CaV channels but did not affect low voltage-activated T-type CaV channels. Cc1a exhibited weak activity at NaV1.5 and NaV1.7 voltage-gated sodium (NaV) channels stably expressed in mammalian HEK or CHO cells, respectively. Experiments with modified Cc1a peptides, truncated at the N-terminus (ΔG1–E5) or C-terminus (ΔW35–V39), demonstrated that the N- and C-termini are important for voltage-gated ion channel modulation. We conclude that Cc1a represents a novel pharmacological tool for probing the structure and function of L-type CaV channels. 相似文献
998.
Xiurui Shen Xiaomei Yang Ying Zhu Xihuan Liu Hongliang Wen 《Journal of labelled compounds & radiopharmaceuticals》2014,57(11):658-659
Curcumin, a pigment isolated from rhizomes of Curcuma longa, is a potent cancer chemopreventive and chemotherapeutic agent and is now evaluated in phase III human clinical trials. This report describes an efficient synthesis of [18O2]‐curcumin. [18O2]‐Curcumin was prepared in three steps from 1‐iodo‐2‐methoxy‐4‐methylbenzene in an overall yield of 53%. 相似文献
999.
1000.
Chih-Hui Yang Chih-Yu Wang Keng-Shiang Huang Chao-Pin Kung Yi-Ching Chang Jei-Fu Shaw 《International journal of pharmaceutics》2014
This paper demonstrates a simple and easy approach for the one-step synthesis of Fe3O4-chitosan composite particles with tadpole-like shape. The length and diameter of the particles were adjustable from 638.3 μm to ca. 798 μm (length), and from 290 μm to 412 μm (diameter) by varying the flow rate of the dispersed phase. Mitoxantrone was used as the model drug in the drug release study. The encapsulation rate of the drug was 71% for chitosan particles, and 69% for magnetic iron oxide-chitosan particles, respectively. The iron oxide-chitosan composite particles had a faster release rate (up to 41.6% at the third hour) than the chitosan particles (about 24.6%). These iron oxide-chitosan composite particles are potentially useful for biomedical applications, such as magnetic responsive drug carriers, magnetic resonance imaging (MRI) enhancers, in the future. 相似文献