全文获取类型
收费全文 | 283篇 |
免费 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 9篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 8篇 |
2015年 | 12篇 |
2014年 | 14篇 |
2013年 | 19篇 |
2012年 | 15篇 |
2011年 | 22篇 |
2010年 | 26篇 |
2009年 | 12篇 |
2008年 | 11篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 28篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 15 毫秒
101.
Kumar Gaurav Lhingjakim Khongsai L. Uppada Jagadeeshwari Ahamad Shabbir Kumar Dhanesh Kashif Gulam Mohammad Sasikala Chintalapati Ramana Chintalapati Venkata 《Antonie van Leeuwenhoek》2021,114(9):1465-1477
Antonie van Leeuwenhoek - Strain JC669T was isolated from a floating island of Loktak lake, Manipur, India and shares the highest 16S rRNA gene sequence identity with Aquisphaera giovannonii OJF2T.... 相似文献
102.
Nirupama Puvvada Sridhar Gunde Ch. Venkata Ramana Devi Raghu Gogada 《Biochemistry and Biophysics Reports》2021
FAD Synthetase (FADS) [EC 2.7.7.2], the second enzyme in flavin cofactor biosynthetic pathway converts FMN to FAD, plays an important role in many redox reactions. Neurospora crassa FADS (NcFADS) was cloned and overexpressed in E. coli cells. Recombinant NcFADS was purified in high yields of ~8 mg per liter of bacterial culture using a single step glutathione sepharose affinity chromatography. SDS-PAGE and MALDI-MS revealed that NcFADS has a molecular mass of ~31 kDa. Enzyme kinetic analysis monitored by reverse phase HPLC demonstrate a specific activity and kcat of 1356 nmol/min/mg and 0.69sec?1 respectively. Steady state kinetic analysis of NcFADS exhibited a Km of NcFADS for FMN is 2.7 μM and for MgATP?2 is 88.7 μM. Isothermal titration calorimetry experiments showed that the recombinant protein binds to the substrates with apparent Kd of 20.8 μM for FMN and 16.6 μM for MgATP?2. Biophysical characterization using intrinsic fluorescence suggests that the enzyme is in folded conformation. Far-UV CD data suggest that the backbone of the enzyme is predominantly in a helical conformation. Differential scanning calorimetry data shows that the Tm is 53 °C ± 1. This is the first report on cloning, purification and characterization of FADS from N. crassa. The specific activity of NcFADS is the highest than any of the reported FADS from any other source. The results obtained in this study is expected to pave way for intensive research aimed to understand the molecular basis for the extraordinarily high turnover rate of NcFADS. 相似文献
103.
V. Koteswara Rao M. Venkata Ramana S. Girisham S. Madhusudhan Reddy 《Archives Of Phytopathology And Plant Protection》2013,46(16):1917-1927
Mycotoxins are natural, secondary metabolites produced by fungi on agricultural commodities in the field and during storage under a wide range of climatic conditions. The ochratoxin A (OTA) is a nephrotoxic mycotoxin produced by several species of Aspergillus and Penicillium. In this study, the influence of carbon and nitrogen sources on ochratoxigenic Penicillium species was assessed. The ochratoxigenic Penicillium species were isolated from poultry feed samples of Andhra Pradesh, India. The isolated ochratoxigenic Penicillium species were identified, screened and characterised as OTA producers by high performance thin layer chromatography (HPTLC) and confirmed by high performance liquid chromatography (HPLC). This experiment was carried out using Czapak yeast Autolysate (CYA) medium with different carbon (C) and nitrogen (N) sources at pH 6.5 and incubated at 25 ± 2°C under dark condition. Maximum OTA production was recorded in the presence of D-glucose followed by D-galactose and D-lactose as carbon sources. Similarly, the maximum amount of OTA production was observed in thiourea followed by potassium nitrate as nitrogen source. However, OTA production, final pH of the medium, and mycelial yield and OTA production of both the species of Penicillium varied with C and N present in the medium. The kinetics of the both species of Penicillium was observed for 30 days at an interval of three days. The maximum amount of OTA was detected by 12 and 15 days incubation periods for Penicillium nordicum and Penicillium verrucosum, respectively. 相似文献
104.
V. Venkata Ramana S. Kalyana Chakravarthy E.V.V. Ramaprasad V. Thiel J.F. Imhoff Ch. Sasikala Ch.V. Ramana 《Systematic and applied microbiology》2013
Five strains (JA325, JA389, JA473, JA563 and JA582) of Gram stain-negative, vibrioid to spiral shaped, phototrophic purple bacteria were isolated from solar salterns of India. All strains contained bacteriochlorophyll-a and carotenoids of the spirilloxanthin series as photosynthetic pigments. C18:1ω7c, C18:1ω7c 11-methyl and C16:0 were the major fatty acids of all strains. Diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), ornithine lipid (OL), an unidentified phospholipid (PL), and an unidentified aminolipid (AL) were the major polar lipids of all the strains. According to 16S rRNA gene sequences, all strains clustered phylogenetically with the only species of the genus Rhodothalassium (99.8–99.3% sequence similarity) but only strains JA325 and JA563 were distinctly related (60 + 1.5% DNA–DNA hybridization [DDH]) to the type strain Rhodothalassium salexigens DSM 2132T. However, the genotypic data of strains JA325 and JA563 was not supported because of a large number of phenotypic differences compared to the type strain, therefore, it is proposed that all five newly isolated strains were R. salexigens-like strains. In addition, phylogenetically, the Rhodothalassium clade represented a distinct lineage and formed a deep branch with less than 90% 16S rRNA gene sequence similarity to other orders of the Alphaproteobacteria, and characteristic phenotypic properties also distinguished these bacteria from other purple non-sulfur bacteria. Therefore, the novel family Rhodothalassiaceae fam. nov. and the novel order Rhodothalassiales ord. nov. are proposed for the distinct phyletic line represented by the genus Rhodothalassium. 相似文献
105.
Wei Wang Jennifer L. Collinger Alan D. Degenhart Elizabeth C. Tyler-Kabara Andrew B. Schwartz Daniel W. Moran Douglas J. Weber Brian Wodlinger Ramana K. Vinjamuri Robin C. Ashmore John W. Kelly Michael L. Boninger 《PloS one》2013,8(2)
Brain-computer interface (BCI) technology aims to help individuals with disability to control assistive devices and reanimate paralyzed limbs. Our study investigated the feasibility of an electrocorticography (ECoG)-based BCI system in an individual with tetraplegia caused by C4 level spinal cord injury. ECoG signals were recorded with a high-density 32-electrode grid over the hand and arm area of the left sensorimotor cortex. The participant was able to voluntarily activate his sensorimotor cortex using attempted movements, with distinct cortical activity patterns for different segments of the upper limb. Using only brain activity, the participant achieved robust control of 3D cursor movement. The ECoG grid was explanted 28 days post-implantation with no adverse effect. This study demonstrates that ECoG signals recorded from the sensorimotor cortex can be used for real-time device control in paralyzed individuals. 相似文献
106.
Carotenoids are known to generate various aldehydes, known as carotenoid-derived aldehydes (CDAs), which could efficiently react with protein or DNA. In this in vitro model study, interaction between CDA and protein has been studied. Various proteins were incubated with CDA, and protein modification and adduct formation were confirmed by using matrix-assisted laser desorption and ionization time-of-flight, amino acid analysis, and measuring enzyme activity on modification with CDA. Using radiolabeled NaB((3) H)H(4) and Raney nickel as well as sulfhydryl assay (Ellman's reagent), we confirmed that CDA could conjugate with cysteine through a thioether linkage. The carbonyl assay using 2,4-dinitrophenylhydrazine revealed the possible involvement of Schiff's base reaction between CDA and lysine. The adducts formed between β-apo-8-carotenal (BA8C) and N-acetylcysteine and BA8C and N-acetyllysine were confirmed by HPLC and ESI-MS. Our results suggest that CDA could alter protein function by post-translational interaction with cysteine and lysine by thioether linkage and by schiff's based bonds, respectively. Thus, the formation of CDA adducts with proteins could alter functional properties of proteins responsible for maintaining cell homeostasis and thereby cause cellular toxicity. In view of these observations, further studies are required to understand the delicate balance between beneficial and/or harmful effects of carotenoids as a dietary supplement to slow age-related macular degeneration progression. 相似文献
107.
108.
Two new complete genome sequences offer insight into host and tissue specificity of plant pathogenic Xanthomonas spp 总被引:1,自引:0,他引:1
Bogdanove AJ Koebnik R Lu H Furutani A Angiuoli SV Patil PB Van Sluys MA Ryan RP Meyer DF Han SW Aparna G Rajaram M Delcher AL Phillippy AM Puiu D Schatz MC Shumway M Sommer DD Trapnell C Benahmed F Dimitrov G Madupu R Radune D Sullivan S Jha G Ishihara H Lee SW Pandey A Sharma V Sriariyanun M Szurek B Vera-Cruz CM Dorman KS Ronald PC Verdier V Dow JM Sonti RV Tsuge S Brendel VP Rabinowicz PD Leach JE White FF Salzberg SL 《Journal of bacteriology》2011,193(19):5450-5464
Xanthomonas is a large genus of bacteria that collectively cause disease on more than 300 plant species. The broad host range of the genus contrasts with stringent host and tissue specificity for individual species and pathovars. Whole-genome sequences of Xanthomonas campestris pv. raphani strain 756C and X. oryzae pv. oryzicola strain BLS256, pathogens that infect the mesophyll tissue of the leading models for plant biology, Arabidopsis thaliana and rice, respectively, were determined and provided insight into the genetic determinants of host and tissue specificity. Comparisons were made with genomes of closely related strains that infect the vascular tissue of the same hosts and across a larger collection of complete Xanthomonas genomes. The results suggest a model in which complex sets of adaptations at the level of gene content account for host specificity and subtler adaptations at the level of amino acid or noncoding regulatory nucleotide sequence determine tissue specificity. 相似文献
109.
110.
Lakshmi Narashimhan Ramana Shilpee Sharma Swaminathan Sethuraman Udaykumar Ranga Uma Maheswari Krishnan 《Biochimica et Biophysica Acta (BBA)/General Subjects》2014