全文获取类型
收费全文 | 489篇 |
免费 | 24篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 10篇 |
妇产科学 | 1篇 |
基础医学 | 29篇 |
口腔科学 | 2篇 |
临床医学 | 31篇 |
内科学 | 77篇 |
皮肤病学 | 9篇 |
神经病学 | 20篇 |
特种医学 | 44篇 |
外科学 | 95篇 |
综合类 | 123篇 |
一般理论 | 1篇 |
预防医学 | 15篇 |
眼科学 | 12篇 |
药学 | 19篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 4篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 2篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 11篇 |
2012年 | 24篇 |
2011年 | 20篇 |
2010年 | 9篇 |
2009年 | 21篇 |
2008年 | 32篇 |
2007年 | 16篇 |
2006年 | 30篇 |
2005年 | 13篇 |
2004年 | 22篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 19篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 23篇 |
1997年 | 28篇 |
1996年 | 21篇 |
1995年 | 5篇 |
1994年 | 11篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1971年 | 4篇 |
1970年 | 2篇 |
排序方式: 共有515条查询结果,搜索用时 593 毫秒
81.
82.
PK Sarkar MD MRCP LA Lambert PhD FRCP 《International journal of clinical practice》2001,55(4):262-268
Recent studies have shown that hyperhomocysteinaemia is a common, independent and easily modifiable risk factor for atherosclerotic and thromboembolic diseases such as cerebrovascular disease, coronary artery disease and venous thrombosis. The vascular risk rises continuously across the spectrum of elevated plasma homocysteine concentrations. It is at least as important as cholesterol, lipoprotein abnormalities and hypertension and should be part of risk assessment, especially those at high risk. Moderately elevated plasma homocysteine concentration is readily correctable by folic acid, betaine, or vitamin B12 supplementation. It seems logical to assume that a reduction in homocysteine concentration will reduce the risk of ischaemic stroke, but there are as yet no published data to prove this. This review will discuss the aetiology and possible treatment of hyperhomocysteinaemia causing ischaemic stroke. 相似文献
83.
Shihab Ezzuldin M. Saber Siti Nurul Ain Md Jamil Luqman Chuah Abdullah Thomas Shean Yaw Choong Teo Ming Ting 《RSC advances》2021,11(14):8150
This study performs an appraisal of the adsorptive capacity of amidoxime-modified poly(acrylonitrile-co-acrylic acid) or abbreviated as (AO-modified poly(AN-co-AA)) for the p-nitrophenol (PNP) adsorption, from aquatic environments via batch system. The AO-modified poly(AN-co-AA) polymer was developed with redox polymerization, and then altered by using hydroxylamine hydrochloride (HH). Tools used to describe the physicochemical and morphological characteristics of the AO-modified poly(AN-co-AA) were Fourier transform infrared (FTIR) spectroscopy, CHN elemental analysis, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The adsorption kinetics were examined by pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion kinetic models. Meanwhile, the isotherms were investigated by Langmuir, Freundlich, Temkin and Redlich–Peterson models. It was found that the adsorption was best fitted with pseudo-second order, and agreed with both Langmuir and Freundlich isotherm models. It was described best with the Freundlich isotherm due to highest R2 (0.999). The maximum adsorption capacity was 143.06 mg g−1 at 298 K, and thermodynamic functions showed that the adsorption process was exothermic. Also, following five regeneration cycles, the adsorbent recorded 71.7% regeneration efficiency. The finding in this study indicates that the AO-modified poly(AN-co-AA) is an effective adsorbent to remove PNP from an aqueous solution.This study performs an appraisal of the adsorptive capacity of amidoxime-modified poly(acrylonitrile-co-acrylic acid) for the p-nitrophenol (PNP) adsorption, from aqueous solutions. 相似文献
84.
Hasan M Shihab Tokunbo Akande Kacie Armstrong Sonal Singh Yoon K Loke 《World Journal of Meta-Analysis》2015,3(6):254-283
AIM: To systematically assess risk of pancreatic adverse events with glucagon-like peptide-1(GLP-1) receptor agonist and dipeptidyl peptidase-4(DPP-4) inhibitor drugs.METHODS: We searched Pub Med, Embase, CINAHL, Cochrane review of clinical trials, pharmaceutical company clinical trials register, United States Food and Drug Administration website, European Medicines Agency website and Clinical Trials.gov for randomized controlled trials from inception to October 2013. Randomized control trial studies were selected for inclusion if they reported on pancreatic complication events and/or changes in pancreatic enzyme levels(serum amylase and serum lipase) as adverse events or as serious adverse events for patients who were on GLP-1 receptor agonist and DPP-4 inhibitor drugs. Two independent reviewers extracted data directly. We performed Peto odds ratio(OR) fixed effect meta-analysis of pancreatic adverse events a, and assessed heterogeneity with the I~2 statistic.RESULTS: Sixty-eight randomized controlled trials were eligible. A total of 60720 patients were included in our analysis of the association of risk of pancreatic complication events with GLP-1 agents. A total of 89 pancreatic related adverse events occurred among the GLP-1 agents compared to 74 events among the controls. There was a statistically significant increased risk of elevation of pancreatic enzymes associated with GLP-1 agents compared with control(Peto OR = 3.15, 95%CI: 1.56-6.39, P = 0.001, I2 = 0%). There was no statistically significant difference in the risk of pancreatic adverse event associated with GLP-1 agent compared with controls(Peto OR = 1.00, 95%CI: 0.73-1.37, P = 1.00, I2 = 0%). There were a total of 71 pancreatitis events in patients on GLP-1 agents and 56 pancreatitis events occurred in the control patients. There were 36 reports of pancreatic cancer in these studies. Of these cases, 2 used linagliptin, 2 used alogliptin, 1 used vildagliptin, 7 used saxagliptin while 6 used sitagliptin. The remaining 18 cases occurred among controls.CONCLUSION: Although GLP-1 based agents are associated with pancreatic enzyme elevation, we were unable to confirm a significant risk of pancreatitis or pancreatic cancer. 相似文献
85.
在美国,食管癌是死亡率最高的恶性肿瘤之一,男性多于女性,其发病率随年龄增长而增加。食管癌临床表现早期食管癌临床表现不明显,吞咽困难是最常见的初始症状,但由于食管壁的柔韧性,病人到晚期才感觉到,从不能吞咽固体开始,进展到最终不能吞咽液体。此外,病人还可有吞咽时疼痛、体重减轻、营养不良和虚弱等表现。晚期表现还包括胸骨后疼痛、呃逆、呼吸困难、胃烧灼感、口臭、声音嘶哑、咳嗽、流涎过多及夜间误吸等。食管切除术后病人的护理食管切除术后24~48 h病人在重症监护室度过,通常带有气管插管等多种导管,护士应加强心肺及各方面的监护… 相似文献
86.
Kessler CM Friedman K Schwartz BA Gill JC Powell JS;Wilate PK Study Investigators 《Thrombosis and haemostasis》2011,106(2):279-288
The pharmacokinetic (PK) profiles of von Willebrand factor (VWF) /factor VIII (FVIII) concentrates are important for treatment efficacy and safety of von Willebrand disease (VWD) patients. This prospective, head-to-head, randomised crossover study compared the PK profile of a new, high purity, human plasma-derived (pd)VWF/FVIII concentrate, Wilate, with the PK profile of an intermediate purity (pd)VWF/FVIII concentrate, Humate-P, in VWD patients. Subjects with inherited VWD were randomised to a single intravenous dose (40 IU/kg VWF ristocetin cofactor activity [VWF:RCo]) of Wilate or Humate-P in Period 1, and switched to the other study drug in Period 2. Each period was preceded by a washout time of ≥ 7 days. Coagulation factor parameters were analysed at multiple time-points. Of 22 randomised subjects, 20 had evaluable PK profiles, which indicated comparability for VWF antigen and VWF:RCo between Wilate and Humate-P. The reported VWF:RCo average and terminal t1/2 of 10.4 and 15.8 hours (h), respectively, for Wilate and 9.3 h and 12.8 h for Humate-P, were not statistically different. Also, the mean VWF:RCo in vivo recoveries (Wilate 1.89, Humate-P 1.99 IU/dl per IU/kg) were similar between the two replacement therapies. Wilate showed parallel decay curves for VWF:RCo and FVIII clotting activity (FVIII:C) over time, while FVIII:C of Humate-P displayed a plateau between 0 and 12-24 h. This study demonstrated bioequivalent PK properties for VWF between Wilate and Humate-P. The PK profile of Wilate, combined with the 1:1 VWF/FVIII ratio, theoretically should facilitate dosing and laboratory monitoring of VWF replacement to prevent bleeding in individuals with VWD. 相似文献
87.
88.
89.
90.
PK Santhosh Deng Yuhua Gu Weidong Chen Xiaoguang 《Asian Pacific journal of tropical medicine》2010,3(3):244-250
Arthropod-borne diseases such as malaria and dengue virus afflict billions of people worldwide imposing major economic and social burdens. Control of such pathogens is mainly performed by vector management and treatment of affected individuals with drugs. The failure of these conventional approaches due to emergence of insecticide-resistant insects and drug-resistant parasites demonstrate the need of novel and efficacious control strategies to combat these diseases. Genetic modification (GM) of mosquito vectors to impair their ability to be infected and transmit pathogens has emerged as a new strategy to reduce transmission of many vector-borne diseases and deliver public health gains. Several advances in developing transgenic mosquitoes unable to transmit pathogens have gained support, some of them attempt to manipulate the naturally occurring endogenous refractory mechanisms, while others initiate the identification of an exogenous foreign gene which disrupt the pathogen development in insect vectors. Heterologous expression of transgenes under a native or heterologous promoter is important for the screening and effecting of the transgenic mosquitoes. The effect of the transgene on mosquito fitness is a crucial parameter influencing the success of this transgenic approach. This review examines these two aspects and describes the basic research work that has been accomplished towards understanding the complex relation between the parasite and its vector and focuses on recent advances and perspectives towards construction of transgenic mosquitoes refractory to vector-borne disease transmission. 相似文献