Biocatalytic processes are increasingly playing a key role in the development of sustainable asymmetric syntheses, which are central to pharmaceutical companies for the production of chiral enantiopure drugs. This work describes a simple and economically viable chemoenzymatic process for the production of (S)-rivastigmine, which is an important drug for the treatment of mild to moderate dementi...

It is unfortunate that the methods used to control dental operative pain may themselves produce distress. It should be the aim of all caring practitioner to reduce injection sensation to minimum so as to alleviate the apprehension and fear from the patient’s mind. The fear of needle prick is a bigger reason of concern and the major cause of avoidance of dental treatment despite the detrimental ...

in the present work, the integral equations method is used to calculate transport properties of polar fluids. for this goal, we use the stockmayer potential and examine theoretically the thermal conductivity of several refrigerant mixtures such as r125+r134a, r125+r32, r125+r152a, r134a+r32, r152a+r32, r134a+r143a, and r125+r143a. we solve numerically the ornstein-zernike (oz) equation using th...

Controlling the growth of eutectic Si and thereby modifying the eutectic Si from flake-like to fibrous is a key factor in improving the properties of Al-Si alloys. To date, it is generally accepted that the impurity-induced twinning (IIT) mechanism and the twin plane re-entrant edge (TPRE) mechanism as well as poisoning of the TPRE mechanism are valid under certain conditions. However, IIT, TPR...

The new lanthanum vanadium oxyselenides LaVSe2O, La5V3Se6O7, La5V3Se7O5, La7VSe5O7, and La13V7Se16O15 were synthesized in eutectic NaI/KI fluxes, and their crystal structures were determined using single-crystal and powder X-ray diffraction experiments. LaVSe2O and La5V3Se6O7 adopt known structure types, whereas La5V3Se7O5, La7VSe5O7, and La13V7Se16O15 crystallize in hitherto unknown structure ...

The synthesis of a macro-initiator from cellulose in mixtures of zincbased ionic liquid and polar solvents including deep eutectic solvent, dimethylformamide, acetone, and tetrahydrofuran (THF) was studied. The results of FTIR and NMR spectroscopies indicated that the cellulose-based macro-initiator can only be obtained in an inert ether solvent, THF. When the amounts of cellulose and zinc-base...

Mannitol, a common pharmaceutical ingredient, exhibits complex polymorphism even in simple binary mannitol/water mixtures, with four crystalline forms observed. In this investigation, time/temperature-resolved synchrotron X-ray diffraction measurements are performed during freezing and thawing of mixtures. Mannitol crystallization depends strongly on the cooling rate is initiated cooling, if lo...

This paper presents and discusses issues relevant to solidification of a chosen lead-free solder, the eutectic Sn-3.5%Ag, and its composite counterparts. Direct temperature recordings for the no-clean solder paste during the simulated reflow process revealed a significant amount of undercooling to occur prior to the initiation of solidification of the eutectic Sn-3.5%Ag solder, which is 6.5 C, ...

Bisfunctional dichlorosilanes were reacted with tetrasilanol of double-decker shaped octaphenylsilsesquioxane (DDSQ) to form fully condensed DDSQ compounds. The crystallographic and thermal characteristics these compounds examined. For capped bearing linear aliphatic moieties, as the number carbon increases from methyl n-butyl (from 1 4) melting temperature, Tm, dropped 546 K 416 K. While for c...