全文获取类型
收费全文 | 211篇 |
免费 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 10篇 |
2013年 | 21篇 |
2012年 | 22篇 |
2011年 | 21篇 |
2010年 | 22篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 9篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有217条查询结果,搜索用时 15 毫秒
1.
M. K. Chandrashekaran G. Marimuthu R. Subbaraj P. Kumarasamy M. S. Ramkumar K. Sripathi 《Journal of biosciences》1991,16(3):97-101
Several bodily functions in humans vary on a 24 h pattern and most of these variations persist with a circadian period ofca 25 h when subjects are studied under conditions of social and temporal isolation. We report in this paper that the estimates
of short time intervals (TE) of 2 h are strongly coupled to the circadian rhythm in sleepwakefulness. There is a linear correlation
between the number of hours humans stay awake (α) and their estimation of 2 h intervals. The coupling of TE to α appears to
obtain only under conditions of physical well-being. 相似文献
2.
Karthick Marimuthu Kamalakannan Ayyanar Malathi Varagur Ganesan Paranidharan Vaikuntavasan Sivakumar Uthandi Kavino Mathiyazhagan Gowrisri Nagaraj 《Journal of Phytopathology》2020,168(3):144-155
Grapes downy mildew caused by obligate oomycete plant pathogen Plasmopara viticola is a devastating disease worldwide, resulting in significant yield and quality losses. A field survey was conducted in two major grapes cultivated areas of Tamil Nadu for the incidence of grapevine downy mildew. The disease incidence was 43.42%–76.69%, and the highest disease incidence of 76.69% was observed in the Theni district. Totally eight P. viticola isolates were collected from different places in Coimbatore and Theni districts. These isolates were confirmed through microscopic observation and sequencing of COX 2 gene, and the phylogenetic tree was developed to study their phylogenetic relationship among the isolates which shows 97–100% sequence similarity with other P. viticola isolates and less sequence similarity with Plasmopara species. The loop-mediated isothermal amplification (LAMP) assay was developed based on the CesA4 gene sequence of P. viticola. The assay developed was more sensitive as it detected P. viticola genomic DNA up to 20 fmg. LAMP assay specificity was proved by carrying out the assay with genomic DNA extracted from other Oomycetes and fungal plant pathogens. Finally, LAMP assay was validated by testing seventy-eight grapevine leaf samples collected from seven different locations. LAMP assay showed a positive reaction in sixty-two samples tested out of seventy-eight samples tested. Therefore, the LAMP assay described should helpful for early and specific detection of downy mildew pathogen and help in mitigating disease incidence. 相似文献
3.
Kannan Karuppiah Sivaranjani Sekar Kumar Rajendran Karuppasamy Karuthapandian Prabhu N. Marimuthu Kannapiran Ethiraj 《Zeitschrift fur angewandte Ichthyologie》2021,37(2):367-369
Length-weight relationship (LWR) parameters were analysed for six demersal finfish species from the Gulf of Mannar coast, Bay of Bengal. Fishes were sampled monthly from the landings of trawlers operated along the coast of Tuticorin and Rameshwaram with a cod-end mesh size of 35 mm at the depth of 60–80 m. Fish specimens were sampled by measuring the total length (TL) and total weight (TW) with precision to 0.1 cm and 0.1 g respectively. The present study also recorded a new maximum total length for Engyprosopon macrolepis, Torquigener brevipinnis and Leiognathus brevirostris. 相似文献
4.
Venkatasamy Vignesh Durairaj Rajesh Karuppaiah Parthiban Sridhar Arun Kamaraj Sathish Kumar Ramasamy Thirumurugan 《International journal of peptide research and therapeutics》2021,27(3):1709-1718
International Journal of Peptide Research and Therapeutics - Subtilosin A, a cyclic peptide from Bacillus subtilis is known for its antimicrobial activity against a diverse range of bacteria.... 相似文献
5.
Saraswathi Umavathi Shahid Mahboob Marimuthu Govindarajan Khalid A. Al-Ghanim Zubair Ahmed P. Virik Norah Al-Mulhm Murugesh Subash Kasi Gopinath C. Kavitha 《Saudi Journal of Biological Sciences》2021,28(3):1808-1815
The present work aims to synthesize zinc oxide (ZnO) nanoparticles via green approaches using leaf extract of Parthenium hysterophorus. UV–vis and FT-IR tests confirmed the existence of biomolecules, active materials, and metal oxides. The X-ray diffraction structural study exposes the ZnO nanoparticles formation with hexagonal phase structures. SEM and TEM analysis reveal surface morphologies of ZnO nanoparticles and most of them are spherical with a size range of 10 nm. ZnO nanoparticles were revealed strong antimicrobial activity against both bacterial and fungal strains. The germination of seeds and vegetative growth of Sesamum indicum has been greatly improved. 相似文献
6.
Jesu Arockiaraj Annie J. Gnanam Rajesh Palanisamy Venkatesh Kumaresan Prasanth Bhatt Muthukumaresan Kuppusamy Thirumalai Arpita Roy Mukesh Pasupuleti Marimuthu Kasi Akila Sathyamoorthi Abirami Arasu 《Biochimie》2013
In this study, we report the bioinformatics characterization, gene expression, transglutaminase activity and coagulation assays of transglutaminase (TGase) of freshwater prawn Macrobrachium rosenbergii identified from the constructed cDNA library by GS FLX™ technology. Even though, TGase have sequence similarity, they differ extensively in their substrate specificity and are thought to play an important in variety of functions such as development, tissue differentiation and immune responses etc. Gene expression studies show that MrTGase is widely distributed in the tissues such as heart, muscle, intestine, brain, etc., but higher amounts are found in hemocyte. Results of TGase mRNA relative expression in hemocyte, before and after infected with white spot syndrome baculovirus (WSBV) and Vibrio harveyi show that the gene expression initially increases up to 24 h and then it falls down. Coagulation assay results showed that the endogenous TGase is involved in the rapid assembly of a specific, plasma clotting protein. Structural studies show that MrTGase contains a typical TGc domain between 323 and 424, and two putative integrin-binding motifs at Arg180–Gly181–Asp182 and Arg269–Gly270–Asp271. The predicted 3D model of MrTGase contains 47.04% coils (366 amino acid residues), 26.74% extended strand (208 residues), 21.72% α-helix (169 residues) and 4.5% beta turns (35 residues). BLASTp analysis of MrTGase exhibited high sequence similarities with other crustacean TGase, with the highest observed in white shrimp (77.1%). Moreover, the phylogenetic analysis also showed that MrTGase clustered with the other members of crustacean TGase. Overall, these results suggested that MrTGase is a major and functional TGase of M. rosenbergii for haemolymph coagulation and also in spread of infection. 相似文献
7.
Anusha Parthiban Selvamani Vijayalingam K. Radha Shanmugasundaram Rema Mohan 《Cell biology international》1995,19(12):987-994
Erythrocytes isolated from 131 cases of Non-Insulin Dependent Diabetes Mellitus (NIDDM) were studied for lipid peroxidation, antioxidant defences, and the maximum peroxidisable substrate in the cell membrane. Antioxidant defences are lowered in NIDDM, followed by significant rise in lipid peroxidation products. However, in the erythrocyte membrane, the total polyunsaturated peroxidisable lipids are lower than in normal erythrocytes which may be a causative factor affecting the survival of the cells. 相似文献
8.
Ramasamy Krishnamoorthy Chang-Gi Kim Parthiban Subramanian Ki-Yoon Kim Gopal Selvakumar Tong-Min Sa 《PloS one》2015,10(6)
Arbuscular Mycorrhizal Fungi (AMF) play major roles in ecosystem functioning such as carbon sequestration, nutrient cycling, and plant growth promotion. It is important to know how this ecologically important soil microbial player is affected by soil abiotic factors particularly heavy metal and metalloid (HMM). The objective of this study was to understand the impact of soil HMM concentration on AMF abundance and community structure in the contaminated sites of South Korea. Soil samples were collected from the vicinity of an abandoned smelter and the samples were subjected to three complementary methods such as spore morphology, terminal restriction fragment length polymorphism (T-RFLP) and denaturing gradient gel electrophoresis (DGGE) for diversity analysis. Spore density was found to be significantly higher in highly contaminated soil compared to less contaminated soil. Spore morphological study revealed that Glomeraceae family was more abundant followed by Acaulosporaceae and Gigasporaceae in the vicinity of the smelter. T-RFLP and DGGE analysis confirmed the dominance of Funneliformis mosseae and Rhizophagus intraradices in all the study sites. Claroideoglomus claroideum, Funneliformis caledonium, Rhizophagus clarus and Funneliformis constrictum were found to be sensitive to high concentration of soil HMM. Richness and diversity of Glomeraceae family increased with significant increase in soil arsenic, cadmium and zinc concentrations. Our results revealed that the soil HMM has a vital impact on AMF community structure, especially with Glomeraceae family abundance, richness and diversity. 相似文献
9.
10.
Ponnandy Prabhu Marimuthu Jeya Jung-Kul Lee 《Applied and environmental microbiology》2010,76(5):1653-1660
Bacillus licheniformis l-arabinose isomerase (l-AI) is distinguished from other l-AIs by its high degree of substrate specificity for l-arabinose and its high turnover rate. A systematic strategy that included a sequence alignment-based first screening of residues and a homology model-based second screening, followed by site-directed mutagenesis to alter individual screened residues, was used to study the molecular determinants for the catalytic efficiency of B. licheniformis l-AI. One conserved amino acid, Y333, in the substrate binding pocket of the wild-type B. licheniformis l-AI was identified as an important residue affecting the catalytic efficiency of B. licheniformis l-AI. Further insights into the function of residue Y333 were obtained by replacing it with other aromatic, nonpolar hydrophobic amino acids or polar amino acids. Replacing Y333 with the aromatic amino acid Phe did not alter catalytic efficiency toward l-arabinose. In contrast, the activities of mutants containing a hydrophobic amino acid (Ala, Val, or Leu) at position 333 decreased as the size of the hydrophobic side chain of the amino acid decreased. However, mutants containing hydrophilic and charged amino acids, such as Asp, Glu, and Lys, showed almost no activity with l-arabinose. These data and a molecular dynamics simulation suggest that Y333 is involved in the catalytic efficiency of B. licheniformis l-AI.l-Arabinose isomerase (l-AI) is an enzyme that mediates in vivo isomerization between l-arabinose and l-ribulose as well as in vitro isomerization of d-galactose and d-tagatose (20). l-Ribulose (l-erythro-pentulose) is a rare and expensive ketopentose sugar (1) that can be used as a precursor for the production of other rare sugars of high market value, such as l-ribose. Despite being a common metabolic intermediate in different organisms, l-ribulose is scarce in nature. The market for rare and unnatural sugars has been growing, especially in the sweetener and pharmaceutical industries. For example, several modified nucleosides derived from l-sugars have been shown to act as potent antiviral agents and are also useful in antigen therapy. Derivatives of rare sugars have also been used as agents against hepatitis B virus and human immunodeficiency virus (2, 22).For these reasons, interest in the enzymology of rare sugars has also been increasing. Various forms of l-AI from a variety of organisms have been characterized, and some have shown potential for industrial use. Several highly thermotolerant enzyme forms from Thermotoga maritima (12), Thermotoga neapolitana (10), Bacillus stearothermophilus (18), Thermoanaerobacter mathranii (9), and Lactobacillus plantarum (5) have been characterized previously. All of these reported l-AIs tend to have broad specificity, although a few l-AIs with high degrees of substrate specificity for l-arabinose have also been documented.The enzyme properties of l-AIs have been examined by engineering several forms by error-prone PCR and site-directed mutagenesis. Galactose conversion was reportedly enhanced 20% following site-directed introduction of a double mutation (C450S-N475K) into l-AI (16). Error-prone PCR manipulation of l-AI from Geobacillus stearothermophilus resulted in a shift in temperature specificity from 60 to 65°C and increased isomerization activity (11). All of these previously reported mutational studies have been aimed at improving enzymatic properties for industrial application. However, even though the three-dimensional (3D) structure of Escherichia coli l-AI has been determined previously (15), few new structural studies have been performed to decipher the reaction mechanism of this enzyme. Rhimi et al. (19) have reported an important role for D308, F329, E351, and H446 in catalysis, as indicated by findings from site-directed mutagenesis. Nonetheless, detailed analysis of the important molecular determinants controlling the catalytic activities of the l-AIs is still lacking.Previously, we have reported the cloning and characterization of a novel l-AI from Bacillus licheniformis (17). This enzyme can be distinguished from other l-AIs by its wide pH range, high degree of substrate specificity for l-arabinose, and extremely high turnover rate. In the present paper, we report the identification of an important amino acid residue responsible for the catalytic efficiency of l-AIs, as determined by a systematic screening process composed of sequence alignment and molecular dynamics (MD) simulation, followed by site-directed mutagenesis. Using the crystal structure of E. coli l-AI as a template, we have built a 3D model of B. licheniformis l-AI. Analysis of the 3D model of B. licheniformis l-AI docked with l-arabinose, followed by a systematic screening process, showed that Y333 interacted with the substrate, suggesting that this residue in B. licheniformis l-AI may be essential for catalysis. We further characterized the role of Y333 in B. licheniformis l-AI binding of and catalytic efficiency for l-arabinose. 相似文献