全文获取类型
收费全文 | 4161篇 |
免费 | 435篇 |
国内免费 | 231篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 54篇 |
妇产科学 | 24篇 |
基础医学 | 620篇 |
口腔科学 | 42篇 |
临床医学 | 534篇 |
内科学 | 699篇 |
皮肤病学 | 75篇 |
神经病学 | 336篇 |
特种医学 | 133篇 |
外国民族医学 | 1篇 |
外科学 | 436篇 |
综合类 | 464篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 316篇 |
眼科学 | 108篇 |
药学 | 370篇 |
中国医学 | 216篇 |
肿瘤学 | 377篇 |
出版年
2024年 | 8篇 |
2023年 | 77篇 |
2022年 | 167篇 |
2021年 | 179篇 |
2020年 | 144篇 |
2019年 | 136篇 |
2018年 | 136篇 |
2017年 | 109篇 |
2016年 | 125篇 |
2015年 | 172篇 |
2014年 | 202篇 |
2013年 | 196篇 |
2012年 | 309篇 |
2011年 | 337篇 |
2010年 | 245篇 |
2009年 | 233篇 |
2008年 | 301篇 |
2007年 | 258篇 |
2006年 | 269篇 |
2005年 | 220篇 |
2004年 | 138篇 |
2003年 | 132篇 |
2002年 | 110篇 |
2001年 | 77篇 |
2000年 | 62篇 |
1999年 | 65篇 |
1998年 | 56篇 |
1997年 | 33篇 |
1996年 | 39篇 |
1995年 | 34篇 |
1994年 | 21篇 |
1993年 | 18篇 |
1992年 | 39篇 |
1991年 | 19篇 |
1990年 | 28篇 |
1989年 | 23篇 |
1988年 | 18篇 |
1987年 | 19篇 |
1986年 | 13篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1971年 | 2篇 |
1966年 | 2篇 |
1935年 | 1篇 |
排序方式: 共有4827条查询结果,搜索用时 31 毫秒
81.
Peter Bergin Lynette Sadleir Benjamin Legros Zarine Mogal Manjari Tripathi Nitika Dang Simone Beretta Clara Zanchi Jorge Burneo Thomas Borkowski Yang Je Cho Michel Ossemann Pasquale Striano Kavita Srivastava Hui Jan Tan Jithangi Wanigasinghe Wendyl D’Souza for the EpiNet study group 《Epilepsia》2012,53(10):1829-1835
Purpose: We created an epilepsy patient database that can be accessed via the Internet by neurologists from anywhere in the world. The database was designed to enroll and follow large cohorts of patients with specific epilepsy syndromes, and to facilitate recruitment of patients for investigator‐initiated clinical trials. Methods: The EpiNet database records physician‐derived information regarding seizure type and frequency, epilepsy syndrome, etiology, drug history, and investigations. It can be accessed from any country by approved investigators via a secure, password‐protected Website. All data are encrypted. The database is for both research and clinical purposes. Investigators were invited to register any patient with epilepsy, but were particularly encouraged to register patients when uncertain of the optimal management. Participation required approval from investigators’ ethics committees and institutional review boards, and all patients or their caregiver provided written informed consent. Patients were not enrolled in clinical trials in this pilot study. Key Findings: The international pilot study recruited patients from September 2010 to November 2011. Sixty‐four investigators or research assistants from 25 centers in 13 countries registered 1,050 patients. Patients with a wide range of epilepsy syndromes and etiologies were registered. Patients’ ages ranged from 2 weeks to 90 years. Significance: The Website was successfully used by doctors working in different health systems. The pilot study confirmed that this low‐cost, collaborative approach to research has great potential. Large, multicenter cohort studies will commence in 2012, and randomized clinical trials are being planned. All epileptologists are invited to join this project. 相似文献
82.
83.
Blümer RM van Thien H Ruiter AF Weverling GJ vinh Thuan D Endert E Kager PA Sauerwein HP 《Metabolism: clinical and experimental》2005,54(1):60-66
Infections are often complicated by an increase in glucose production due to stimulation of the secretion of glucose counter-regulatory hormones and cytokines. Adiponectin, a fat-derived hormone with insulin-sensitizing properties, could play a regulatory role in the degree of stimulation of glucose production by the infectious agent. Therefore, we investigated the possible correlation between glucose production and plasma adiponectin levels in 25 subjects: 7 patients with cerebral malaria, 6 with uncomplicated malaria, and 12 matched controls. Glucose production was significantly higher in patients with malaria compared to healthy controls (P < .001). Adiponectin levels were not different between the patients with malaria and the control group. However, patients with cerebral malaria had significantly higher values for adiponectin than the patients with uncomplicated malaria (P < .005). Glucose production and gluconeogenesis were positively correlated to plasma adiponectin in the patients (r = 0.835, P < .001 and r = 0.846, P < .001, respectively), whereas these correlations were absent in the controls (r = -0.329, NS and r = -0.028, NS, respectively). In conclusion, adiponectin levels were not different between patients with malaria and their matched controls. However, patients infected with Plasmodium falciparum who have higher glucose production also have higher adiponectin levels. In healthy subjects such a correlation was not found. As adiponectin is known to inhibit glucose production, stimulation of adiponectin secretion during infection could be intended to restrain the glucose production stimulating properties of hormones and cytokines secreted during infection. 相似文献
84.
Postoperative complications: does intensive care unit staff nursing make a difference? 总被引:5,自引:0,他引:5
Dang D Johantgen ME Pronovost PJ Jenckes MW Bass EB 《Heart & lung : the journal of critical care》2002,31(3):219-228
OBJECTIVE: The purpose of this study was to examine the association between intensive care unit nurse (ICU) staffing and the likelihood of complications for patients undergoing abdominal aortic surgery. DESIGN: The study is a retrospective review of hospital discharge data linked to data on ICU organizational characteristics. SETTING: Research took place in ICUs in non-federal, short-stay hospitals in Maryland. PATIENTS: Study included 2606 patients undergoing abdominal aortic surgery in Maryland between January 1994 and December 1996. Outcome Measures: Outcome measures included cardiac, respiratory, and other complications. RESULTS: Cardiac complications occurred in 13% of patients, respiratory complications occurred in 30%, and other complications occurred in 8% of patients. Multiple logistic regression revealed a statistically significant increased likelihood of respiratory complications (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.50-3.60) in abdominal aortic surgery patients cared for in ICUs with low- versus high-intensity nurse staffing, an increased likelihood of cardiac complications (OR, 1.78; CI, 1.16-2.72) and other complications (OR, 1.74; CI, 1.15-2.63) in ICUs with medium- versus high-intensity nurse staffing, after controlling for patient and organizational characteristics. CONCLUSIONS: Within the range of ICU nurse staffing levels present in Maryland hospitals, decreased nurse staffing was significantly associated with an increased risk of complications in patients undergoing abdominal aortic surgery. 相似文献
85.
Eun-Joo Shin Yoon Hee Chung Hoang-Lan Thi Le Ji Hoon Jeong Duy-Khanh Dang Yunsung Nam Myung Bok Wie Seung-Yeol Nah Yo-Ichi Nabeshima Toshitaka Nabeshima Hyoung-Chun Kim 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2015,18(6)
Background:
We demonstrated that oxidative stress plays a crucial role in cognitive impairment in klotho mutant mice, a genetic model of aging. Since down-regulation of melatonin due to aging is well documented, we used this genetic model to determine whether the antioxidant property of melatonin affects memory impairment.Methods:
First, we examined the effects of melatonin on hippocampal oxidative parameters and the glutathione/oxidized glutathione (GSH/GSSG) ratio and memory dysfunction of klotho mutant mice. Second, we investigated whether a specific melatonin receptor is involved in the melatonin-mediated pharmacological response by application with melatonin receptor antagonists. Third, we examined phospho-extracellular-signal-regulated kinase (ERK) expression, nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, Nrf2 DNA binding activity, and glutamate-cysteine ligase (GCL) mRNA expression. Finally, we examined effects of the ERK inhibitor SL327 in response to antioxidant efficacy and memory enhancement mediated by melatonin.Results:
Treatment with melatonin resulted in significant attenuations of oxidative damage, a decrease in the GSH/GSSG ratio, and a significant amelioration of memory impairment in this aging model. These effects of melatonin were significantly counteracted by the selective MT2 receptor antagonist 4-P-PDOT. Importantly, 4-P-PDOT or SL327 also counteracted melatonin-mediated attenuation in response to the decreases in phospho-ERK expression, Nrf2 nuclear translocation, Nrf2 DNA-binding activity, and GCL mRNA expression in the hippocampi of klotho mutant mice. SL327 also counteracted the up-regulation of the GSH/GSSG ratio and the memory enhancement mediated by melatonin in klotho mutant mice.Conclusions:
Melatonin attenuates oxidative stress and the associated memory impairment induced by klotho deficiency via signaling interaction between the MT2 receptor and ERK- and Nrf2-related antioxidant potential. 相似文献86.
Peng-qian Wang Bing Li Jun Liu Ying-ying Zhang Ya-nan Yu Xiao-xu Zhang Ye Yuan Zhi-li Guo Hong-li Wu Hai-xia Li Hai-xia Dang Shan-shan Guo Zhong Wang 《Acta pharmacologica Sinica》2015,36(6):734-747
Aim:
Our previous studies have showed that ursodeoxycholic acid (UA) and jasminoidin (JA) effectively reduce cerebral infarct volume in mice. In this study we explored the pure synergistic mechanism of these compounds in treatment of mouse cerebral ischemia, which was defined as synergistic actions specific for phenotype variations after excluding interference from ineffective compounds.Methods:
Mice with focal cerebral ischemia were treated with UA, JA or a combination JA and UA (JU). Concha margaritifera (CM) was taken as ineffective compound. Cerebral infarct volume of the mice was determined, and the hippocampi were taken for microarray analysis. Particular signaling pathways and biological functions were enriched based on differentially expressed genes, and corresponding networks were constructed through Ingenuity Pathway Analysis.Results:
In phenotype analysis, UA, JA, and JU significantly reduced the ischemic infarct volume with JU being superior to UA or JA alone, while CM was ineffective. As a result, 4 pathways enriched in CM were excluded. Core pathways in the phenotype-positive groups (UA or JA) were involved in neuronal homeostasis and neuropathology. JU-contributing pathways included all UA-contributing and the majority (71.7%) of JA-contributing pathways, and 10 new core pathways whose effects included inflammatory immunity, apoptosis and nervous system development. The functions of JU group included all functions of JA group, the majority (93.1%) of UA-contributing functions, and 3 new core functions, which focused on physiological system development and function.Conclusion:
The pure synergism between UA and JA underlies 10 new core pathways and 3 new core functions, which are involved in inflammation, immune responses, apoptosis and nervous system development. 相似文献87.
Wang Yue Wang Yue Jiang Hong-feng Dang Hai-ming Liu Meng-ru Liu Xin-yan Yu Yang Xie Jiang Zhan Xiao-jun Zhang Hui-na Wu Xiao-fan 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》2022,36(5):805-815
Cardiovascular Drugs and Therapy - It has been established that obstructive sleep apnea (OSA) is an independent risk factor for atherosclerosis. Chronic intermittent hypoxia (CIH) activates... 相似文献
88.
Drought- and salt-tolerant plants result from overexpression of the AVP1 H+-pump 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Gaxiola RA Li J Undurraga S Dang LM Allen GJ Alper SL Fink GR 《Proceedings of the National Academy of Sciences of the United States of America》2001,98(20):11444-11449
Transgenic plants overexpressing the vacuolar H(+)-pyrophosphatase are much more resistant to high concentrations of NaCl and to water deprivation than the isogenic wild-type strains. These transgenic plants accumulate more Na(+) and K(+) in their leaf tissue than the wild type. Moreover, direct measurements on isolated vacuolar membrane vesicles derived from the AVP1 transgenic plants and from wild type demonstrate that the vesicles from the transgenic plants have enhanced cation uptake. The phenotypes of the AVP1 transgenic plants suggest that increasing the vacuolar proton gradient results in increased solute accumulation and water retention. Presumably, sequestration of cations in the vacuole reduces their toxic effects. Genetically engineered drought- and salt-tolerant plants could provide an avenue to the reclamation of farmlands lost to agriculture because of salinity and a lack of rainfall. 相似文献
89.
90.