排序方式: 共有11条查询结果,搜索用时 15 毫秒
1.
Mathematical Programming - Functional constrained optimization is becoming more and more important in machine learning and operations research. Such problems have potential applications in... 相似文献
2.
An Improved Protocol for DNA Extraction from Alkaline Soil and Sediment Samples for Constructing Metagenomic Libraries 总被引:1,自引:0,他引:1
An improved single-step protocol has been developed for extracting pure community humic substance-free DNA from alkaline soils
and sediments. The method is based on direct cell lysis in the presence of powdered activated charcoal and polyvinylpolypyrrolidone
followed by precipitation with polyethyleneglycol and isopropanol. The strategy allows simultaneous isolation and purification
of DNA while minimizing the loss of DNA with respect to other available protocols for metagenomic DNA extraction. Moreover,
the purity levels are significant, which are difficult to attain with any of the methods reported in the literature for DNA
extraction from soils. The DNA thus extracted was free from humic substances and, therefore, could be processed for restriction
digestion, PCR amplification as well as for the construction of metagenomic libraries. 相似文献
3.
Digvijay Gahtory Dr. Rickdeb Sen Andriy R. Kuzmyn Dr. Jorge Escorihuela Prof. Dr. Han Zuilhof 《Angewandte Chemie (International ed. in English)》2018,57(32):10118-10122
Novel click reactions are of continued interest in fields as diverse as bio‐conjugation, polymer science and surface chemistry. Qualification as a proper “click” reaction requires stringent criteria, including fast kinetics and high conversion, to be met. Herein, we report a novel strain‐promoted cycloaddition between cyclopropenes and o‐quinones in solution and on a surface. We demonstrate the “click character” of the reaction in solution and on surfaces for both monolayer and polymer brush functionalization. 相似文献
4.
P. C. Pandey Digvijay Pandey Richa Singh 《Applied biochemistry and biotechnology》2012,168(4):936-946
Purple membrane (PM) has been extracted and purified from archaebacteria for thin film development. The purified purple membrane is isolated in 1?% polyvinyl alcohol solution for making thin film within gelatin and organically modified silicate matrices. For thin film within gelatin matrix, homogenized purple membrane suspension is mixed with 8?% gelatin and poured into a specially designed block with desired thickness of spacer having hydrophobicity followed by gelatinization of the same over home-made thermostatic control unit at 38?°C. The gelatinized matrix is then allowed to dry under controlled conditions of humidity and temperature. The films of varying thicknesses ranging between 40, 50, and 60??? are used for photo-electrochemical measurements. The results on photo-electrochemistry of non-oriented purple membrane film provides valuable information on the generation of forward (light on) and backward (light off) photocurrent as a function of: (a) applied potential and (b) film thickness. An increase in applied negative potential increases the amplitude of photocurrent whereas decrease in film thickness facilitates the reversibility of photocurrent response. 相似文献
5.
Jaworski JW Raorane D Huh JH Majumdar A Lee SW 《Langmuir : the ACS journal of surfaces and colloids》2008,24(9):4938-4943
Susceptibility of chemical sensors to false positive signals remains a common drawback due to insufficient sensor coating selectivity. By mimicking biology, we have demonstrated the use of sequence-specific biopolymers to generate highly selective receptors for trinitrotoluene and 2,4-dinitrotoluene. Using mutational analysis, we show that the identified binding peptides recognize the target substrate through multivalent binding with key side chain amino acid elements. Additionally, our peptide-based receptors embedded in a hydrogel show selective binding to target molecules in the gas phase. These experiments demonstrate the technique of receptor screening in liquid to be translated to selective gas-phase target binding, potentially impacting the design of a new class of sensor coatings. 相似文献
6.
Digvijay Verma Ashima Anand T. Satyanarayana 《Applied biochemistry and biotechnology》2013,170(1):119-130
Xylanase encoding gene (1,224 bp) from Geobacillus thermodenitrificans was cloned in pET28a (+) vector and successfully expressed in Escherichia coli BL21 (DE3). The deduced amino acid sequence analysis revealed homology with that of glycosyl hydrolase (GH) 10 family with a high molecular mass (50 kDa). The purified recombinant xylanase is optimally active at pH 9.0 and 70 °C with T 1/2 of 10 min at 80 °C, and retains greater than 85 % activity after exposure to 70 °C for 180 min. The enzyme liberates xylose as well as xylooligosaccharides from birchwood xylan and agro-residues, and therefore, this is an endoxylanase. The xylan hydrolytic products (xylooligosaccharides, xylose, and xylobiose) find application as prebiotics and in the production of bioethanol. The xylanase being thermostable and alkalistable, it has released chromophores and phenolics from the residual lignin of pulps, suggesting its utility in mitigating chlorine requirement in pulp bleaching. 相似文献
7.
Digvijay S Shashi PR Suchi S Kumar RS Raghavendra M Sushil K 《Journal of AOAC International》2004,87(6):1287-1296
A new, rapid, sensitive, and reproducible reversed-phase liquid chromatographic (LC) method with photodiode array detection is described. It allows, in a single run of 30 min, simultaneous separation of 6 pharmaceutically and biologically important Catharanthus roseus leaf and root terpenoid indole alkaloids (TIAs) and 3 of their precursors: TIA precursors tryptophan, tryptamine, and loganine; and TIAs serpentine, catharanthine, ajmalicine, vincristine, vinblastine, and vindoline. The method involves the use of a Phenomenex Luna 5 microm, C18 column (250 mm x 4.6 mm id) and a linear binary gradient mobile phase profile. Detection is performed at 220 and 254 nm, which provided good absorptivity for all of the roseus compounds listed above and gave a minimum detection limit of 0.02 microg/mL. The extraction efficiency, peak purity, and homogeneity parameters of the profiles could be validated using a photodiode array detector. The method was successfully used to quantify major components of leaf and root extracts of C. roseus accessions. The new method thus provides a reliable tool for rapid screening of C. roseus samples in large numbers, which is needed in breeding/genetic engineering and genetic mapping experiments and for monitoring the reaction products, in the in vitro/in vivo conversions of precursors into products, and vice versa. 相似文献
8.
Gupta Padmini Garkoti Charu Shabir Javaid Surabhi Sah Digvijay Mozumdar Subho 《Research on Chemical Intermediates》2021,47(10):4013-4028
Research on Chemical Intermediates - This work describes the synthesis of magnetic graphene oxide (MGO), where iron oxide (Fe3O4) nanoparticles were uniformly deposited over the sheets of the... 相似文献
9.
Inside Cover: Strain‐Promoted Cycloaddition of Cyclopropenes with o‐Quinones: A Rapid Click Reaction (Angew. Chem. Int. Ed. 32/2018) 下载免费PDF全文
10.
Extending the Scope of the B(C6F5)3‐Catalyzed CN Bond Reduction: Hydrogenation of Oxime Ethers and Hydrazones 下载免费PDF全文
Jens Mohr Digvijay Porwal Dr. Indranil Chatterjee Prof. Dr. Martin Oestreich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17583-17586
The B(C6F5)3‐catalyzed hydrogenation is applied to aldoxime triisopropylsilyl ethers and hydrazones bearing an easily removable phthaloyl protective group. The C?N reduction of aldehyde‐derived substrates (oxime ethers and hydrazones) is enabled by using 1,4‐dioxane as the solvent known to participate as the Lewis‐basic component in FLP‐type heterolytic dihydrogen splitting. More basic ketone‐derived hydrazones act as Lewis bases themselves in the FLP‐type dihydrogen activation and are therefore successfully hydrogenated in nondonating toluene. The difference in reactivity between aldehyde‐ and ketone‐derived substrates is also reflected in the required catalyst loading and dihydrogen pressure. 相似文献