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111.
Convenient and straightforward tetrabutylammonium bromide (TBAB), benzyltrienthylammonium chloride (BTEAC), and cetyltrimethylammonium bromide (CTAB) catalyzed synthesis of 1,4-dihydropyridines (1,4-DHPs) in water was established for the first time. The catalytic potential of phase-transfer catalysts (PTCs) in three different concentrations was envisioned. Aryl aldehydes and hetero aryl aldehydes afforded good yields of 1,4-DHPs in TBAB and BTEAC reactions. In particular, furfuraldehyde and thienyl-2-carbaldehyde produced excellent yields. Isolation of the products through nonchromatographic methods, good to excellent yields, and benign reaction conditions are the major advantages of this protocol. 相似文献
112.
Procedure for hydrothermal synthesis of ZSM-8-type zeolite crystals, using TEA—OH as a template, in the system having molar composition 16.2 (Na2O) — Al2O3 — 117 (SiO2) — 4.8 (TEA)2O — 3887 H2O at 170 °C is described. Results of characterization of these crystals by XRD, IR, EDAX, SEM, TGA, and adsorption studies are described and discussed. X-ray diffraction studies establish that the crystals are ZSM-8-type with structure similar to that of ZSM-5-type crystals. Crystals have prismatic bipyramidal morphology with average size 18–25 microns. Degased calcined samples adsorb xylenes in the order p > m > 0. Pore length per unit cell, estimated from n-hexane adsorption studies, is 46 Å. 相似文献
113.
Monisha Prasad Selvaraj Jayaraman Mohamed Ahmed Eladl Mohamed El-Sherbiny Mosaab Abdella Ebrahim Abdelrahman Vishnu Priya Veeraraghavan Srinivasan Vengadassalapathy Vidhya Rekha Umapathy Shazia Fathima Jaffer Hussain Kalaiselvi Krishnamoorthy Durairaj Sekar Chella Perumal Palanisamy Surapaneni Krishna Mohan Ponnulakshmi Rajagopal 《Molecules (Basel, Switzerland)》2022,27(5)
Natural products in the form of functional foods have become increasingly popular due to their protective effects against life-threatening diseases, low risk of adverse effects, affordability, and accessibility. Plant components such as phytosterol, in particular, have drawn a lot of press recently due to a link between their consumption and a modest incidence of global problems, such as Type 2 Diabetes mellitus (T2DM), cancer, and cardiovascular disease. In the management of diet-related metabolic diseases, such as T2DM and cardiovascular disorders, these plant-based functional foods and nutritional supplements have unquestionably led the market in terms of cost-effectiveness, therapeutic efficacy, and safety. Diabetes mellitus is a metabolic disorder categoriszed by high blood sugar and insulin resistance, which influence major metabolic organs, such as the liver, adipose tissue, and skeletal muscle. These chronic hyperglycemia fallouts result in decreased glucose consumption by body cells, increased fat mobilisation from fat storage cells, and protein depletion in human tissues, keeping the tissues in a state of crisis. In addition, functional foods such as phytosterols improve the body’s healing process from these crises by promoting a proper physiological metabolism and cellular activities. They are plant-derived steroid molecules having structure and function similar to cholesterol, which is found in vegetables, grains, nuts, olive oil, wood pulp, legumes, cereals, and leaves, and are abundant in nature, along with phytosterol derivatives. The most copious phytosterols seen in the human diet are sitosterol, stigmasterol, and campesterol, which can be found in free form, as fatty acid/cinnamic acid esters or as glycosides processed by pancreatic enzymes. Accumulating evidence reveals that phytosterols and diets enriched with them can control glucose and lipid metabolism, as well as insulin resistance. Despite this, few studies on the advantages of sterol control in diabetes care have been published. As a basis, the primary objective of this review is to convey extensive updated information on the possibility of managing diabetes and associated complications with sterol-rich foods in molecular aspects. 相似文献
114.
A. K. Rebane C. W. Thiel R. K. Mohan R. L. Cone 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(7):891-900
We analyze the material requirements for recording, storage, and processing of optically encoded information using coherent
optical transients in resonant solids. We introduce new figures of merit (FOM’s) that explicitly account for the ratio between
the rate of the decoherence and the rate of the spontaneous radiative decay. Highest FOM values are achieved when the decoherence
rate approaches the fundamental limit set by spontaneous emission under the condition that the total transition oscillator
strength is concentrated between a single pair of energy levels. We analyze FOM’s of some of the most promising rare-earth-doped
crystals at cryogenic temperatures. 相似文献
115.
Mixed ionic and electronic conductivity of three solid charge transfer (CT) complexes of pyridine, 4-methylpyridine (γ-picoline) and 3,5-dimethylpyridine (3,5-lutidine) with ICl (iodine monochloride) are reported. Electrical parameters of the prepared complexes in the pellet form are evaluated at various temperatures and at wide frequency range by employing AC complex impedance spectroscopic technique. Suitable equivalent circuits for the Nyquist plots, which provide the most realistic model of the electrical properties of the CT complexes, have been suggested. Both transport number measurements and impedance spectra reveal that the conduction in γ-picoline-ICl complex is mainly due to ions, in 3,5-dimethylpyridine-ICl complex, it is due to both ions and electrons and in pyridine-ICl complex, it is predominantly due to electrons. The a.c. conductivity measurements of the CT complexes have been carried out in the frequency range of 10–105 Hz within the temperature range of 303–353 K. The variation of a.c. conductivity with frequency follows the Jonscher’s universal power law. The temperature dependence of electrical conductivity suggests the semiconducting behaviour of the materials. 相似文献
116.
In this paper we obtain global controllability of a semilinear system involving monotone nonlinearities of both Lipschitzian and non-Lipschitzian types. 相似文献
117.
Bipin Singh Koranga Mohan Narayan S. Uma Sankar 《International Journal of Theoretical Physics》2011,50(3):760-766
The neutrino parameters determined from the solar neutrino data and the anti-neutrino parameters determined from KamLAND reactor
experiment are in good agreement with each other. However, the best fit points of the two sets differ from each other by about
10−5 eV2 in mass-square difference and by about 2° in the mixing angle. Future solar neutrino and reactor anti-neutrino experiments
are likely to reduce the uncertainties in these measurements. This, in turn, can lead to a signal for CPT violation in terms
a non-zero difference between neutrino and anti-neutrino parameters. In this paper, we propose a CPT violating mass matrix
which can give rise to the above differences in both mass-squared difference and mixing angle and study the constraints imposed
by the data on the parameters of the mass matrix. 相似文献
118.
Gold recovery from spent materials has been performed on modified cation-exchange resin. The modified resin was prepared by sorption of Rhodamine-B on Dowex-50-X8 (Na+) resin at pH 2.0. Distribution coefficients of gold ion have been determined with 15% (w/v) potassium chloride in different concentrations of hydrochloric acid. On the basis of Kd values quantitative separation of gold from secondary sources has been achieved. Gold(III) has been selectively separated from gold containing spent materials by column chromatography using modified ionexchange resin and the recovery was more than 92% compared to conventional cyanidation process. The results of the proposed method are suggestive of its applicability to other gold containing secondary sources. 相似文献
119.
120.
A photon echo experiment in Tm(3+):YAG is reported that shows, for the first time to the authors' knowledge, the time-domain equivalent of the transition from near- to far-field diffraction, including Talbot self-imaging effects. The experiment demonstrates the huge dispersion capability of photon echoes and opens the way to further exploration of space-time duality. 相似文献