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排序方式: 共有117条查询结果,搜索用时 11 毫秒
101.
Kaliyaperumal Ashokkumar Paramasivam Sivakumar Muthukrishnan Saradhadevi 《Natural product research》2018,32(14):1733-1737
The genetic potential and biofortification of India-grown rice with bioavailable folate has not been studied yet. The objectives of this study were to determine the folates concentration in four cultivars of rice through UPLC–MS/MS. Total folate concentration in rice cultivars ranged from 11.0 to 51 μg/100 g with a mean of 26.0 μg/100 g. Among the four rice cultivars, the pigmented grain cultivar Nootripathu possesses two-fold rich sources of total folates than the other three non-pigmented grain cultivars. The average value of 100 g serving of rice grains could provide the amount of recommended daily allowance (% RDA) of dietary folates (6.5%) for adults, which ranged from 2.7–12.7%. Among the 5 individual forms of folates, 5-methyltetrahydrofolate was most abundant in rice cultivars followed by 10-Formylfolic acid and folic acid. The result of this study has been useful for biofortification of folates in rice. 相似文献
102.
Pathinettam PD Muthukrishnan C Murugesan R 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(3):509-517
EPR spectra of single crystals of Mn(II)-doped sarcosine cadmium chloride and sarcosine cadmium bromide are studied in Q-band and in X-band at room temperature. Two magnetically inequivalent sites are observed in both the lattices in a distorted octahedral environment. The spin-Hamiltonian parameters are extracted and are found to have a rhombic symmetry. The angular variation of the zero-field transitions is simulated for one of the sites with an asymmetric zero-field tensor D = 480 x 10(-4) cm(-1), E = -115 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium chloride and with D = 460 x 10(-4) cm(-1) E = -98 x 10(-4) cm(-1) and a = 10 x 10(-4) cm(-1) for Mn(II) in sarcosine cadmium bromide. The observed large value of zero-field tensor is due to the steric effects of the crystal packing caused by the ligands. Matumura's plot predicts an average covalency of 8.8 and 7.7% for the manganese-ligand bond in SCC and SCB lattices respectively. 相似文献
103.
The problem of stability in a compressible boundary layer, as opposed to an incompressible layer, involves many parameters and requires consideration of three-dimensional perturbations. The transverse component of the velocity, the thermal regime at the wall, etc., take on great significance. Investigation of all aspects of this problem requires systematic calculations performed by electronic computers. There do exist a few calculations of stability of a compressible boundary layer with respect to three-dimensional disturbances for particular cases. It follows from those studies (see, for example, [1]) that consideration of three-dimensional perturbations and of the transverse component of the basic flow velocity is important. Many aspects of this problem remain uninvestigated. Aside from the sheer cumbersomeness of the problem, there exist purely mathematical difficulties connected with the presence of a small parameter with higher derivatives in the differential equations for the perturbations, which causes losses in accuracy of calculation. In this present study an algorithm will be developed for solution of the problem of stability of a compressible boundary layer relative to three-dimensional disturbances with consideration of the transverse component of the basic velocity. Calculations are performed for a boundary layer on a plane thermally insulating plate, and the effects of the transverse velocity component and the three-dimensionality of the perturbations on stability at various Mach numbers are demonstrated. 相似文献
104.
Arumugam Vijaya Anand Balasubramanian Balamuralikrishnan Mohandass Kaviya Kathirvel Bharathi Aluru Parithathvi Meyyazhagan Arun Nachiappan Senthilkumar Shanmugam Velayuthaprabhu Muthukrishnan Saradhadevi Naif Abdullah Al-Dhabi Mariadhas Valan Arasu Mohammad Iqbal Yatoo Ruchi Tiwari Kuldeep Dhama 《Molecules (Basel, Switzerland)》2021,26(6)
The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome corona virus-2 (SARS-CoV-2), is the most important health issue, internationally. With no specific and effective antiviral therapy for COVID-19, new or repurposed antiviral are urgently needed. Phytochemicals pose a ray of hope for human health during this pandemic, and a great deal of research is concentrated on it. Phytochemicals have been used as antiviral agents against several viruses since they could inhibit several viruses via different mechanisms of direct inhibition either at the viral entry point or the replication stages and via immunomodulation potentials. Recent evidence also suggests that some plants and its components have shown promising antiviral properties against SARS-CoV-2. This review summarizes certain phytochemical agents along with their mode of actions and potential antiviral activities against important viral pathogens. A special focus has been given on medicinal plants and their extracts as well as herbs which have shown promising results to combat SARS-CoV-2 infection and can be useful in treating patients with COVID-19 as alternatives for treatment under phytotherapy approaches during this devastating pandemic situation. 相似文献
105.
K Saravanan M. Ilayaraja P. Muthukrishnan S. Ananthakrishnan P. Ravichandiran 《印度化学会志》2022,99(8):100575
We used a simple two-stage tactic to design and synthesize a magnetically separable catalyst (MSC) Ag/Fe3O4 by combining independently synthesized Fe3O4 and Jatropha curcas root functionalized Ag nanoparticles (NPs) at room temperature. The phase composition of Ag/Fe3O4 NCs was revealed by morphological and structural assessment. The derived Ag/Fe3O4 nanocomposites demonstrated outstanding antimicrobial activity against Gram-negative Pseudomonas aeruginosa comparing to Gram-positive Bacillus subtilis which was determined by the agar well diffusion method. This is due to positively charged surface of metal oxide NPs that may bind to cell membrane. Interestingly, Ag–Fe3O4 NCs demonstrated good photocatalytic activity for organic dye degradation. According to a kinetic study, Ag/Fe3O4 MSC removed 99% of Rhodamine B at a rate constant of 1.89 min?1. The photoelectron could perhaps ultimately collide only with dissolved solids in the substrate to form superoxides, which can damage the dye. Notably, the MSCs reusability was tested using magnetic detachment without sacrificing photocatalytic efficiency. This finding represents a significant breakthrough in the domain of wastewater treatment and biomedicine. 相似文献
106.
D. R. Ghadse D. M. Noronha I. C. Pius M. M. Charyulu A. R. Joshi C. K. Sivaramakrishnan 《Journal of Radioanalytical and Nuclear Chemistry》1996,213(3):225-232
Sorption of Pu(IV) from hydrochloric acid-oxalic acid solutions has been investigated using different anion exchangers, viz., Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) for the recovery of plutonium from plutonium oxalate solutions. Distribution ratios of Pu(IV) for its sorption on these anion exchangers have been determined. The sorption of Pu(IV) from hydrochloric acid solutions decreases drastically in the presence of oxalic acid. However, addition of aluminium chloride enhances the sorption of plutonium in the presence of oxalic acid, indicating the feasibility of recovery of plutonium. Pu(IV) breakthrough capacities have been determined with a 10 ml resin bed of each of these anion exchangers at a flow rate of 60 ml per hour using a solution of Pu(IV) with the composition: 6M HCl+0.05M HNO3+0.1M H2C2O4+0.5M AlCl3+100 mg.l–1 Pu(IV). The 10% Pu(IV) breakthrough capacities for Dowex-1X4, Amberlite XE-270 (MP) and Amberlyst A-26 (MP) are 15.0, 8.9 and 6.2 g of Pu(IV) l–1 of resin respectively. 相似文献
107.
The oxidation of a few methyl naphthols with tetrachloro-o-benzoquinone (1) has been described. Reaction of 1-methyl-2-naphthol (4) with the quinone (1) was found to give the spirodimer, 1,1′,2,2′-tetrahydro-3H-benzo (f) chromen-3-spiro-1′-naphthalene-2′-one (6) and a yellow solid which has been assigned the structure of 5,6,7,8-tetrachloro-1,4-benzodioxan-2-spiro-1′-naphthalen-2′-one (7) on the basis of chemical and spectral data. Among the other naphthols studied, 4-methyl-2-t-butyl-1-naphthol afforded 5,6,7,8-tetrachloro-1,4-benzodioxan-2-spiro-1′-naphthalen-3′-t-butyl-4′-one (22) while 2-methyl-1-naphthol and 4-methyl-1-naphthol gave 2-methyl-4,4-(tetrachloro-o-phenylenedioxy) naphthalen-1(4H)-one(15) and 4-methyl-2,2-(tetrachloro-o-phenylenedioxy) naphthelen-1(2H)-one (19) respectively. The present study has shown that oxidation of suitably substituted naphthols with the quinone (1) gives rise to naphthoquinone methides. 相似文献
108.
I. C. Pius M. M. Charyulu B. Venkataramani C. K. Sivaramakrishnan S. K. Patil 《Journal of Radioanalytical and Nuclear Chemistry》1995,199(1):1-7
Sorption of Pu(IV) from sodium carbonate medium has been investigated by using three inorganic ion exchangers, viz. alumina, silica gel and hydrous titanium oxide (HTO). Distribution ratios (D) of Pu(IV) for its sorption on these ion exchangers have been determined. The values are 700, 103 and 104 for alumina, silica gel and hydrous titanium oxide, respectively, from 0.1M sodium carbonate medium. The high distribution ratios indicate their suitability for the removal of Pu(IV) from sodium carbonate waste streams. Pu(IV) breakthrough capacities have been determined with 5 ml bed at a flow rate of 30 ml per hour. The 10% Pu(IV) breakthough capacities for alumina and silica gel are 3 g l–1 and 14 g l–1, respectively. The capacity of HTO is 60 g of Pu(IV) per liter of exchanger at 4% Pu(IV) breakthrough. 相似文献
109.
Platt M Muthukrishnan G Hancock WO Williams ME 《Journal of the American Chemical Society》2005,127(45):15686-15687
The conjugation of 14 nm diameter CoFe2O4 nanoparticles to the surface of biotinylated microtubules enables their manipulation with externally applied magnetic fields of small, permanent NdFeB magnets. Microtubules are selectively patterned on kinesin motor-modified glass surfaces in coparallel arrays that mimic the orientation of the magnetic field lines over millimeter distances. The magnetic field is simultaneously used to increase surface loading of microtubules. We demonstrate that motility across the kinesin motor surface is retained following magnetic functionalization of the microtubules, while gliding speed is dependent on loading level of the neutravidin linker as well as magnetic nanoparticles. 相似文献
110.
Singh PN Mandel SM Sankaranarayanan J Muthukrishnan S Chang M Robinson RM Lahti PM Ault BS Gudmundsdóttir AD 《Journal of the American Chemical Society》2007,129(51):16263-16272
Photolysis of beta-azido propiophenone derivatives, 1, with built-in sensitizer units, leads to selective formation of triplet alkyl nitrenes 2 that were detected directly with laser flash photolysis (lambdamax = 325 nm, tau = 27 ms) and ESR spectroscopy (|D/hc| = 1.64 cm-1, |E/hc| = 0.004 cm-1). Nitrenes 2 were further characterized with argon matrix isolation, isotope labeling, and molecular modeling. The triplet alkyl nitrenes are persistent intermediates that do not abstract H-atoms from the solvent but do decay by dimerizing with another triplet nitrene to form azo products, rather than reacting with an azide precursor. The azo dimer tautomerizes and rearranges to form heterocyclic compound 3. Nitrene 2a, with an n,pi* configuration as the lowest triplet excited state of the its ketone sensitizer moiety, undergoes intramolecular 1,4-H-atom abstraction to form biradical 6, which was identified by argon matrix isolation, isotope labeling, and molecular modeling. beta-Azido-p-methoxy-propiophenone, with a pi,pi* lowest excited state of its triplet sensitizer moiety, does not undergo any secondary photoreactions but selectively yields only triplet alkyl nitrene intermediates that dimerize to form 3b. 相似文献