全文获取类型
收费全文 | 1055篇 |
免费 | 53篇 |
专业分类
1108篇 |
出版年
2024年 | 3篇 |
2023年 | 11篇 |
2022年 | 29篇 |
2021年 | 34篇 |
2020年 | 15篇 |
2019年 | 17篇 |
2018年 | 17篇 |
2017年 | 25篇 |
2016年 | 30篇 |
2015年 | 34篇 |
2014年 | 32篇 |
2013年 | 53篇 |
2012年 | 74篇 |
2011年 | 84篇 |
2010年 | 53篇 |
2009年 | 45篇 |
2008年 | 59篇 |
2007年 | 37篇 |
2006年 | 33篇 |
2005年 | 35篇 |
2004年 | 36篇 |
2003年 | 43篇 |
2002年 | 38篇 |
2001年 | 35篇 |
2000年 | 36篇 |
1999年 | 33篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1993年 | 3篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 18篇 |
1989年 | 17篇 |
1988年 | 9篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 9篇 |
1982年 | 3篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1970年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有1108条查询结果,搜索用时 0 毫秒
221.
Alvarado-Esquivel C Cruz-Magallanes HM Esquivel-Cruz R Estrada-Martínez S Rivas-González M Liesenfeld O Martínez-García SA Ramírez E Torres-Castorena A Castañeda A Dubey JP 《The Journal of parasitology》2008,94(4):811-816
There is scarce information concerning the epidemiology of Toxoplasma gondii infection in people of rural Mexico. Anti-T. gondii immunoglobulin (Ig)G and IgM antibodies were sought in 462 adult inhabitants from 3 rural communities of Durango, Mexico, using enzyme-linked immunoassays. In total, 110 (23.8%) of 463 persons had IgG anti-T. gondii antibodies. Ten (2.2%) of them also had IgM anti-T. gondii antibodies. Prevalences of T. gondii IgG antibodies in the 3 communities varied from 14.8 to 35.8%. The highest prevalence of infection was observed in participants older than 70 yr and in those with good housing conditions. Toxoplasma gondii infection was significantly associated with consumption of squirrel (adjusted odds ratio [OR] = 4.22; 95% confidence interval [CI] = 1.11-16.05) and turkey meat (adjusted OR = 4.58; 95% CI = 1.14-18.44). This is the first epidemiological study of T. gondii prevalence in rural Mexico. 相似文献
222.
Nirogi RV Kambhampati R Kothmirkar P Konda J Bandyala TR Gudla P Arepalli S Gangadasari NP Shinde AK Deshpande AD Dwarampudi A Chindhe AK Dubey PK 《Journal of enzyme inhibition and medicinal chemistry》2012,27(3):443-450
5-Hydroxytryptamine 6 receptors (5-HT(6)R) are being perceived as the possible target for treatment of cognitive disorders as well as obesity. The present article deals with the design, synthesis, in vitro binding and structure-activity relationship of a novel series of tetracyclic tryptamines with the rigidized N-arylsulphonyl, N-arylcarbonyl and N-benzyl substituents as 5-HT(6) receptor ligands. The chiral sulphonyl derivatives 15a and 17a showed high affinity at 5-HT(6)R with the K(i) of 23.4 and 20.5?nM, respectively. The lead compound from the series 15a has acceptable ADME properties, adequate brain penetration and is active in animal models of cognition like Novel Object Recognition Task (NORT) and water maze. 相似文献
223.
Ramakrishna V.S. Nirogi Anand V. Daulatabad G. Parandhama Shaikh Mohammad K.R. Sastri Anil K. Shinde P.K. Dubey 《Bioorganic & medicinal chemistry letters》2010,20(15):4440-4443
A series of novel aryl aminosulfonamides was designed and synthesized as 5-HT6 receptor ligands. Many compounds screened in a functional reporter gene based assay displayed potent antagonistic activity with Kb values in the range of 0.02–10 nM. The lead compound 11m exemplified in this series showed good ADME surrogate properties, acceptable pharmacokinetic profile and is active in animal models of cognition like novel object recognition test and Morris water maze. The compound was selected for detailed profiling. 相似文献
224.
225.
226.
Priyanka Singh Ravindra Shukla Ashok Kumar Bhanu Prakash Shubhra Singh Nawal Kishore Dubey 《Mycopathologia》2010,170(3):195-202
Essential oils extracted from Citrus reticulata and Cymbopogon citratus were tested in vitro against the toxigenic strain of Aspergillus flavus, isolated from the tuberous roots of Asparagus racemosus, used in preparation of herbal drugs. The essential oils completely inhibited the growth of A. flavus at 750 ppm and also exhibited a broad fungitoxic spectrum against nine additional fungi isolated from the roots. Citrus reticulata and Cymbopogon citratus essential oils completely inhibited aflatoxin B1 production at 750 and 500 ppm, respectively. During in vivo investigation, the incidence of fungi and aflatoxin B1 production decreased considerably in essential oil-treated root samples. The findings thus indicate possible exploitation of the essential oils as effective inhibitor of aflatoxin B1 production and as post-harvest fungitoxicant of traditionally used plant origin for the control of storage fungi. These essential oils may be recommended as plant-based antifungals as well as aflatoxin B1 suppressors in post-harvest processing of herbal samples. 相似文献
227.
C. Suresh A. K. Dubey S. Srikanta S. Umesh Kumar N. G. Karanth 《Applied microbiology and biotechnology》1999,51(5):673-675
A UV-induced mutant strain of Aspergillus niger (CFTRI-1105-U9) overproduced a starch-hydrolysing enzyme with properties characteristically different from the known amylases
of the fungus. The purified enzyme of 4.0 pI had an apparent molecular mass of 125 kDa and it dextrinised starch and then
saccharified the dextrins. Patterns of the enzyme activity on starch, resulting in glucose at 60 °C and glucose, maltose and
maltodextrins at 70 °C as primary products, suggested significant applications for the enzyme in starch-processing industries.
Received: 29 October 1998 / Received revision: 11 January 1999 / Accepted: 19 January 1999 相似文献
228.
Knowledge of science and the scientific method are important in learning about and using evidence-based medicine in practice. Courses in research methodology have been introduced for both medical students and practicing doctors. In Pokhara, the basic science subjects are taught in an integrated manner during the first four semesters of the undergraduate medical course. Studies on students' attitudes towards and knowledge of science are lacking in medical colleges in Nepal. Hence the study was carried out to obtain information on students' attitude towards and knowledge of science and scientific methodology among preclinical medical students and note the association, if any, of students' attitudes and their demographic characteristics. The study was carried out in March 2005 among the students of the first four semesters at the Manipal College of Medical Sciences, Pokhara, Nepal using a questionnaire developed by Hren and coworkers. Two hundred and twenty students (overall response rate 73.3%) successfully completed the questionnaire. Seventy-five respondents were Nepalese, 115 were Indians, 27 were Sri Lankans and 3 belonged to other nationalities. The X +/- SD total attitude score was 147.4 +/- 10.8 (neutral score 135). The X +/- SD scores on the subscales, value of science to humanity, value of scientific methodology and value of science to medicine were 51.3 +/- 5.4, 39.6 +/- 3.7 and 58.5 +/- 5.9 (neutral scores were 36, 51 and 48 respectively). The knowledge score measured using a set of 8 multiple choice questions was 3.3 +/- 1.4. The attitude scores were lower and the knowledge score was comparable to that reported previously in a study in Croatia but higher than that reported from Southeast Europe. 相似文献
229.
The organism associated with EPM is a protozoan. It bears greatest resemblance to the genus Sarcocystis based on the mode of replication, staining characteristics, location in host cells, serology and epidemiology. However, attempts to produce the disease in equids by oral inoculation with many species of Sarcocystis have been unsuccessful. Because the distribution of EPM is limited to North America, further attempts to identify the organism and its source should focus on animal sources unique to that continent. 相似文献
230.
Chevuru Sai Shreya Reddy Gayatri Devi Ramalingam J Selvaraj A Jothi Priya 《Bioinformation》2022,18(4):337
It is of interest to analyse and compare the antioxidant and anti-diabetic activity of ethanolic extracts of Andrographis echioides and Andrographis paniculata. Andrographis echioides and Andrographis paniculata were collected from a local farm. In vitro antioxidant activity was assessed by the potential of Piperine, Lupeol, beta sitosterol; DPPH free radical scavenging assay was performed by Liyana Pathirana and Shahidi method. In vitro anti-diabetic activity was assessed by alpha amylase inhibitory activity and alpha glucosidase inhibitory activity. The data were analysed by one-way-ANOVA to check the statistical significance among the groups and considered at the levels of p<0.05. Both the ethanolic extracts of Andrographis echioides and Andrographis paniculata showed significant antioxidant and anti-diabetic potential in a dose-dependent manner (100-500µg) and can be used as potential antidiabetic agents. Similar to antioxidant potential, Andrographis paniculata exhibited an increased anti-diabetic potential compared to Andrographis echioides. Data shows that the ethanolic extracts of Andrographis echioides and Andrographis paniculata possessed antioxidant and anti-diabetic activity and hence our present findings conclude that both plants can be considered for the development of natural drugs for the management of diabetes. 相似文献