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1.
P. Esakkiraj G. Austin Jeba Dhas A. Palavesam G. Immanuel 《Applied biochemistry and biotechnology》2010,160(4):1254-1265
Extracellular lipase production by Staphylococcus epidermidis CMST Pi 2 isolated from the intestine of shrimp Penaeus indicus has been investigated in shake-flask experiment using different preparations of tuna-processing waste such as raw fish meat,
defatted fish meat, alkali hydrolysate, and acid hydrolysate as nitrogen source. Among the tested tuna preparations, defatted
fish meat supported the maximum lipase production, and 2.5% concentration of the same was found to be optimum for maximizing
the lipase production. The effect of carbon sources on lipase production revealed that glucose aided the higher lipase production
than any other tested carbon source and a concentration of 2% glucose registered as optimum to enhance the lipase production.
The halotolerancy of S. epidermidis CMST Pi 2 for lipase production indicated that 4% of sodium chloride was optimum to yield maximum lipase. Among the surfactants
tested, lipase production was high in Tween 20 added medium when compared to other surfactants, and its optimum concentration
recorded was 0.8%. Partial characterization of crude enzyme revealed that pH 7 and 55 °C temperature were optimum for maximum
lipase activity. 相似文献
2.
Kumar VG Gokavarapu SD Rajeswari A Dhas TS Karthick V Kapadia Z Shrestha T Barathy IA Roy A Sinha S 《Colloids and surfaces. B, Biointerfaces》2011,87(1):159-163
A simple biological method for the synthesis of gold nanoparticles (AuNPs) using Cassia auriculata aqueous leaf extract has been carried out in the present study. The reduction of auric chloride led to the formation of AuNPs within 10 min at room temperature (28°C), suggesting a higher reaction rate than chemical methods involved in the synthesis. The size, shape and elemental analysis were carried out using X-ray diffraction, TEM, SEM-EDAX, FT-IR and visible absorption spectroscopy. Stable, triangular and spherical crystalline AuNPs with well-defined dimensions of average size of 15-25 nm were synthesized using C. auriculata. Effect of pH was also studied to check the stability of AuNPs. The main aim of the investigation is to synthesize AuNPs using antidiabetic potent medicinal plant. The stabilizing and reducing molecules of nanoparticles may promote anti-hyperglycemic if tested further. 相似文献
3.
Dhas DA Joe IH Roy SD Balachandran S 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):993-1003
Vibrational analysis of the thionocarbamate fungicide tolnaftate which is antidermatophytic, antitrichophytic and antimycotic agent, primarily inhibits the ergosterol biosynthesis in the fungus, was carried out using NIR FT-Raman and FTIR spectroscopic techniques. The equilibrium geometry, various bonding features, harmonic vibrational wavenumbers and torsional potential energy surface (PES) scan studies have been computed using density functional theory method. The detailed interpretation of the vibrational spectra has been carried out with the aid of VEDA.4 program. Vibrational spectra, natural bonding orbital (NBO) analysis and optimized molecular structure show the clear evidence for electronic interaction of thionocarbamate group with aromatic ring. Predicted electronic absorption spectrum from TD-DFT calculation has been compared with the UV-vis spectrum. The Mulliken population analysis on atomic charges and the HOMO-LUMO energy were also calculated. Vibrational analysis reveals that the simultaneous IR and Raman activation of the C-C stretching mode in the phenyl and naphthalene ring provide evidence for the charge transfer interaction between the donor and acceptor groups and is responsible for its bioactivity as a fungicide. 相似文献
4.
L‐Valinium picrate (C5H12NO2)+. (C6H2N3O7)–, a non‐linear optical material from the amino acid family which has large second harmonic generation (SHG) efficiency, was grown by slow evaporation method. Characterization of the crystals was made using single crystal X‐ray diffraction. The functional groups and the modes of vibrations were found by using the Fourier transform infrared (FTIR) spectroscopy. The second harmonic generation (SHG) conversion efficiency was investigated using the Kurtz and Perry method. The SHG conversion efficiency is 60 times higher than that of the standard KDP and 8 times higher than that of the standard Urea and the optical transparency was analyzed using UV‐visible‐NIR absorption spectrum. The structural features of the material leading to the large SHG efficiency are discussed. Microhardness and dielectric studies were also carried out. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
S.A. Martin Britto Dhas 《Optics Communications》2008,281(3):457-462
Single crystals of organic nonlinear optical (NLO) materials l-Histidine nitrate (C6H10N3O2)+ · (NO3)− and l-Cysteine tartrate monohydrate (C3H8NO2S)+ · (C4H5O6)− · H2O were grown by submerged seed solution method. Characterization of the crystals was made using single crystal X-ray diffraction. Fourier transform infrared (FTIR) spectroscopic studies, optical behaviour such as UV-visible-NIR absorption spectra and second harmonic generation (SHG) conversion efficiency were investigated to explore the NLO characteristics of the above materials. Microhardness measurements and dielectric studies of the compounds were also carried out. 相似文献
6.
Single crystals of L‐Prolinium tartrate (C5H10NO2)+ (C4H5O6)‐, a new organic non‐linear optical material of size: 15 × 10 × 10 mm3 were grown using submerged seed solution growth method. Characterization of the crystals was made using single crystal X‐ray diffraction and density determination. Spectroscopic, thermal, optical and mechanical studies were carried out. These studies show that the crystals are thermally stable upto 161°C, transparent for the fundamental and second harmonic generation of Nd: YAG (λ = 1064 nm) laser and possess good mechanical strength. Second harmonic generation (SHG) conversion efficiency was investigated to explore the NLO characteristics of this material using Kurtz and Perry method and it was found that the SHG conversion efficiency is about 90% of that of the standard KDP crystals. Laser damage threshold study was also carried out. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
7.
S. A. Martin Britto Dhas M. Suresh P. Raji K. Ramachandran S. Natarajan 《Crystal Research and Technology》2007,42(2):190-194
Photoacoustic spectroscopy (PAS) is a non‐destructive testing (NDT) tool and used here for analyzing the physical properties such as thermal diffusivity, thermal diffusion length, thermal conductivity and thermal effusivity of L‐Threonine and L‐Prolinium tartrate. These two crystals belong to a group of recently developed NLO materials, in our laboratory. The single crystals of the two compounds were grown by using submerged seed solution growth method. Characterization of the crystals was made by using single crystal X‐ray diffraction. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
8.
Nagarajan Shobana Pandurangan Prakash Antony V. Samrot P. J. Jane Cypriyana Purohit Kajal Mahendran Sathiyasree Subramanian Saigeetha T. Stalin Dhas D. Alex Anand Gokul Shankar Sabesan Bala Sundaram Muthuvenkatachalam Basanta Kumar Mohanty Sridevi Visvanathan 《Molecules (Basel, Switzerland)》2022,27(12)
Plant gums are bio-organic substances that are derived from the barks of trees. They are biodegradable and non-adverse complex polysaccharides that have been gaining usage in recent years due to a number of advantages they contribute to various applications. In this study, gum was collected from Moringa oleifera and Azadirachta indica trees, then dried and powdered. Characterizations of gum polysaccharides were performed using TLC, GC-MS, NMR, etc., and sugar molecules such as glucose and xylose were found to be present. Effects of the gums on Abelmoschus esculentus growth were observed through root growth, shoot growth, and biomass content. The exposure of the seeds to the plant gums led to bio stimulation in the growth of the plants. Poor quality soil was exposed to the gum polysaccharide, where the polysaccharide was found to improve soil quality, which was observed through soil analysis and SEM analysis of soil porosity and structure. Furthermore, the plant gums were also found to have bio-pesticidal activity against mealybugs, which showed certain interstitial damage evident through histopathological analysis. 相似文献
9.
Sonochemical preparation of Co and Ni promoted MoS(2) supported on alumina was achieved by high-intensity ultrasonic irradiation of isodurene solutions containing molybdenum carbonyl, dicobalt octacarbonyl, elemental sulfur, and Al(2)O(3) or Ni-Al(2)O(3) under Ar flow. The sonochemically prepared catalysts were characterized by elemental analysis, XPS, SEM, TEM, and XEDS, and hydrodesulfurization (HDS) activity evaluated for thiophene and dibenzothiophene substrates. The TEM studies on the sonochemically prepared catalysts indicate the formation of layered hexagonal MoS(2) (lattice fringes approximately 6.2 A) on the alumina support. The sonochemically prepared Co-Mo-S/Al(2)O(3), Ni-Mo-S/Al(2)O(3), and Co-Ni-Mo-S/Al(2)O(3) are extremely active catalysts for the HDS of thiophene and dibenzothiophene, with activities severalfold those of comparable commercial catalysts under identical conditions. The layered structure of MoS(2) remained intact after 120 h of HDS, and the catalyst is reusable. 相似文献
10.
Monica S. Esther Santhoshi Dhas C. Ravi Venkatesh R. Sivakumar R. Vignesh R. Ferby V. Anslin 《Journal of Solid State Electrochemistry》2022,26(5):1271-1290
Journal of Solid State Electrochemistry - Herein, we have analyzed for the first time on the synergetic effect of NiO and MnOx towards electrochromic behaviour in comparison with pristine NiO films... 相似文献