全文获取类型
收费全文 | 3231篇 |
免费 | 192篇 |
国内免费 | 279篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 7篇 |
妇产科学 | 14篇 |
基础医学 | 290篇 |
口腔科学 | 32篇 |
临床医学 | 120篇 |
内科学 | 510篇 |
皮肤病学 | 97篇 |
神经病学 | 35篇 |
特种医学 | 64篇 |
外科学 | 61篇 |
综合类 | 556篇 |
预防医学 | 457篇 |
眼科学 | 10篇 |
药学 | 483篇 |
中国医学 | 905篇 |
肿瘤学 | 57篇 |
出版年
2024年 | 5篇 |
2023年 | 44篇 |
2022年 | 102篇 |
2021年 | 163篇 |
2020年 | 72篇 |
2019年 | 60篇 |
2018年 | 58篇 |
2017年 | 92篇 |
2016年 | 86篇 |
2015年 | 138篇 |
2014年 | 218篇 |
2013年 | 275篇 |
2012年 | 217篇 |
2011年 | 217篇 |
2010年 | 195篇 |
2009年 | 172篇 |
2008年 | 148篇 |
2007年 | 115篇 |
2006年 | 126篇 |
2005年 | 125篇 |
2004年 | 121篇 |
2003年 | 90篇 |
2002年 | 91篇 |
2001年 | 78篇 |
2000年 | 75篇 |
1999年 | 121篇 |
1998年 | 47篇 |
1997年 | 79篇 |
1996年 | 78篇 |
1995年 | 47篇 |
1994年 | 51篇 |
1993年 | 26篇 |
1992年 | 15篇 |
1991年 | 22篇 |
1990年 | 21篇 |
1989年 | 20篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 16篇 |
1984年 | 15篇 |
1983年 | 6篇 |
1982年 | 4篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有3702条查询结果,搜索用时 15 毫秒
101.
Anje A. te Velde Florence Brüll Sigrid E. M. Heinsbroek Sybren L. Meijer Dieter Lütjohann Anita Vreugdenhil Jogchum Plat 《Nutrients》2015,7(10):8518-8531
In this study, we evaluated the effects of dietary plant sterols and stanols as their fatty acid esters on the development of experimental colitis. The effects were studied both in high- and low-fat diet conditions in two models, one acute and another chronic model of experimental colitis that resembles gene expression in human inflammatory bowel disease (IBD). In the first experiments in the high fat diet (HFD), we did not observe a beneficial effect of the addition of plant sterols and stanols on the development of acute dextran sulphate sodium (DSS) colitis. In the chronic CD4CD45RB T cell transfer colitis model, we mainly observed an effect of the presence of high fat on the development of colitis. In this HFD condition, the presence of plant sterol or stanol did not result in any additional effect. In the second experiments with low fat, we could clearly observe a beneficial effect of the addition of plant sterols on colitis parameters in the T cell transfer model, but not in the DSS model. This positive effect was related to the gender of the mice and on Treg presence in the colon. This suggests that especially dietary plant sterol esters may improve intestinal inflammation in a T cell dependent manner. 相似文献
102.
Appadurai Daniel Reegan Munusamy Rajiv Gandhi Micheal Gabriel Paulraj Savarimuthu Ignacimuthu 《Osong Public Health and Research Perspectives》2015,6(1):64-69
Objectives
To evaluate the ovicidal and oviposition deterrent activities of five medicinal plant extracts namely Aegle marmelos (Linn.), Limonia acidissima (Linn.), Sphaeranthus indicus (Linn.), Sphaeranthus amaranthoides (burm.f), and Chromolaena odorata (Linn.) against Culex quinquefasciatus and Aedes aegypti mosquitoes. Three solvents, namely hexane, ethyl acetate, and methanol, were used for the preparation of extracts from each plant.Methods
Four different concentrations—62.5 parts per million (ppm), 125 ppm, 250 ppm, and 500 ppm—were prepared using acetone and tested for ovicidal and oviposition deterrent activities. One-way analysis of variance (ANOVA) was used to determine the significance of the treatments and means were separated by Tukey''s test of comparison.Results
Among the different extracts of the five plants screened, the hexane extract of L. acidissima recorded the highest ovicidal activity of 79.2% and 60% at 500 ppm concentration against the eggs of Cx. quinquefasciatus and Ae. aegypti, respectively. Similarly, the same hexane extract of L. acidissima showed 100% oviposition deterrent activity at all the tested concentrations against Cx. quinquefasciatus and Ae. aegypti adult females.Conclusion
It is concluded that the hexane extract of L. acidissima could be used in an integrated mosquito management program. 相似文献103.
通过对胜利油田污水厂污泥泥质的全分析、对生活污泥进行好氧堆肥研究、污泥好氧堆肥产品的土地利用效果评价,得出油区城市污水厂的生活污泥产品可以用做土壤改良剂。 相似文献
104.
Konstantin Musiychuk Natalie Stephenson Hong Bi Christine E. Farrance Goran Orozovic Maria Brodelius Peter Brodelius April Horsey Natalia Ugulava Abdel‐Moneim Shamloul Vadim Mett Shailaja Rabindran Stephen J. Streatfield Vidadi Yusibov 《Influenza and other respiratory viruses》2007,1(1):19-25
Historically, most vaccines have been based on killed or live‐attenuated infectious agents. Although very successful at immunizing populations against disease, both approaches raise safety concerns and often have limited production capacity. This has resulted in increased emphasis on the development of subunit vaccines. Several recombinant systems have been considered for subunit vaccine manufacture, including plants, which offer advantages both in cost and in scale of production. We have developed a plant expression system utilizing a ‘launch vector’, which combines the advantageous features of standard agrobacterial binary plasmids and plant viral vectors, to achieve high‐level target antigen expression in plants. As an additional feature, to aid in target expression, stability and purification, we have engineered a thermostable carrier molecule to which antigens are fused. We have applied this launch vector/carrier system to engineer and express target antigens from various pathogens, including, influenza A/Vietnam/04 (H5N1) virus. 相似文献
105.
《Immunopharmacology and immunotoxicology》2013,35(4):556-562
Polyphenols from the extracts of Areca catechu L. and Quercus infectoria Oliv. inhibited phospholipase A2, proteases, hyaluronidase and L-amino acid oxidase of Naja naja kaouthia Lesson (NK) and Calloselasma rhodostoma Kuhl (CR) venoms by in vitro tests. Both extracts inhibited the hemorrhagic activity of CR venom and the dermonecrotic activity of NK venom by in vivo tests. The inhibitory activity of plant polyphenols against local tissue necrosis induced by snake venoms may be caused by inhibition of inflammatory reactions, hemorrhage, and necrosis. The result implies the therapeutic potential of plant polyphenols against necrosis in snakebite victims. 相似文献
106.
Reza Taherkhani Sakineh Taherkhani Fatemeh Farshadpour 《World Journal of Clinical Cases》2021,9(18):4480-4490
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the most recent global health threat, is spreading throughout the world with worrisome speed, and the current wave of coronavirus disease 2019 (COVID-19) seems to have no mercy. While this mysterious virus challenges our ability to control viral infections, our opportunities to control the COVID-19 pandemic are gradually fading. Currently, pandemic management relies on preventive interventions. Although prevention is a good strategy to mitigate SARS-CoV-2 transmission, it still cannot be considered an absolute solution to eliminate this pandemic. Currently, developing a potent immunity against this viral infection seems to be the most promising strategy to drive down this ongoing global tragedy. However, with the emergence of new challenges in the context of immune responses to COVID-19, the road to control this devastating pandemic seems bumpier; thus, it is pivotal to characterize the dynamics of host immune responses to COVID-19, in order to develop efficient prophylactic and therapeutic tools. This begs the question of whether the effector mechanisms of the immune system are indeed potent or a possible contributing factor to developing more severe and lethal forms of COVID-19. In this review, the possible role of the immunopathologic phenomena including antibody-dependent enhancement, cytokine storm, and original antigenic sin in severity and mortality of COVID-19 will be discussed. 相似文献
107.
Chiu TL Wen Z Rupasinghe SG Schuler MA 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(26):8855-8860
One of the challenges faced in malarial control is the acquisition of insecticide resistance that has developed in mosquitoes that are vectors for this disease. Anopheles gambiae, which has been the major mosquito vector of the malaria parasite Plasmodium falciparum in Africa, has over the years developed resistance to insecticides including dieldrin, 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT), and pyrethroids. Previous microarray studies using fragments of 230 An. gambiae genes identified five P450 loci, including CYP4C27, CYP4H15, CYP6Z1, CYP6Z2, and CYP12F1, that showed significantly higher expression in the DDT-resistant ZAN/U strain compared with the DDT-susceptible Kisumu strain. To predict whether either of the CYP6Z1 and CYP6Z2 proteins might potentially metabolize DDT, we generated and compared molecular models of these two proteins with and without DDT docked in their catalytic sites. This comparison indicated that, although these two CYP6Z proteins share high sequence identity, their metabolic profiles were likely to differ dramatically from the larger catalytic site of CYP6Z1, potentially involved in DDT metabolism, and the more constrained catalytic site of CYP6Z2, not likely to metabolize DDT. Heterologous expressions of these proteins have corroborated these predictions: only CYP6Z1 is capable of metabolizing DDT. Overlays of these models indicate that slight differences in the backbone of SRS1 and variations of side chains in SRS2 and SRS4 account for the significant differences in their catalytic site volumes and DDT-metabolic capacities. These data identify CYP6Z1 as one important target for inhibitor design aimed at inactivating insecticide-metabolizing P450s in natural populations of this malarial mosquito. 相似文献
108.
Ganiyu Oboh Opeyemi Babatunde Ogunsuyi Mariam Damilola Ogunbadejo Stephen Adeniyi Adefegha 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2016,24(3):627
Acarbose is an antidiabetic drug which acts by inhibiting α-amylase and α-glucosidase activities but with deleterious side effects. Gallic acid (GA) is a phenolic acid that is widespread in plant foods. We therefore investigated the influence of GA on α-amylase and α-glucosidase inhibitory properties of acarbose (in vitro). Aqueous solutions of acarbose and GA were prepared to a final concentration of 25μM each. Thereafter, mixtures of the samples (50% acarbose + 50% GA; 75% acarbose + 25% GA; and 25% acarbose + 75% GA) were prepared. The results revealed that the combination of 50% acarbose and 50% GA showed the highest α-glucosidase inhibitory effect, while 75% acarbose + 25% GA showed the highest α-amylase inhibitory effect. Furthermore, all the samples caused the inhibition of Fe2+-induced lipid peroxidation (in vitro) in rat pancreatic tissue homogenate, with the combination of 50% acarbose and 50% GA causing the highest inhibition. All the samples also showed antioxidant properties (reducing property, 2,2′-azino-bis (-3-ethylbenzthiazoline-6-sulphonate [ABTS*] and 1,1-diphenyl-2-picrylhydrazyl [DPPH] free radicals scavenging abilities, and Fe2+ chelating ability). Therefore, combinations of GA with acarbose could be employed as antidiabetic therapy, with a possible reduction of side effects of acarbose; nevertheless, the combination of 50% acarbose and 50% GA seems the best. 相似文献
109.
110.
ObjectiveTo identify medicinal plants witch are used for headaches and migraines treatment in Lorestan province of Iran.MethodsTraditional medical herbs information was acquired from indigenous people with the cooperation of health centers of Doroud, Borujerd, Khorramabad, Aleshtar Poldokhtar, Aligoodarz, Nourabad and Kouhdasht cities. The prepared questionnaires were given to trained health volunteers. They attended in the villages and recorded people beliefs in herbal therapy by the questionnaires.ResultsThe results of this study showed that people used 15 herbs traditionally to treat headaches. Because of the importance of the medicinal plants in the study area, it is neccessary to determine sociological studies the plenty of plant species.ConclusionsBecause of the widespread use of traditional medicinal plants and high tendency to herbal medicine and traditional medicine, more extensive researches should be designed in several areas of pharmacy and pharmacology of medicinal plants to prepare proper information for pharmaceutical industries. 相似文献