Dietary Flavonoids: Cardioprotective Potential with Antioxidant Effects and Their Pharmacokinetic,Toxicological and Therapeutic Concerns

Flavonoids comprise a large group of structurally diverse polyphenolic compounds of plant origin and are abundantly found in human diet such as fruits, vegetables, grains, tea, dairy products, red wine, etc. Major classes of flavonoids include flavonols, flavones, flavanones, flavanols, anthocyanidins, isoflavones, and chalcones. Owing to their potential health benefits and medicinal significance, flavonoids are now considered as an indispensable component in a variety of medicinal, pharmaceutical, nutraceutical, and cosmetic preparations. Moreover, flavonoids play a significant role in preventing cardiovascular diseases (CVDs), which could be mainly due to their antioxidant, antiatherogenic, and antithrombotic effects. Epidemiological and in vitro/in vivo evidence of antioxidant effects supports the cardioprotective function of dietary flavonoids. Further, the inhibition of LDL oxidation and platelet aggregation following regular consumption of food containing flavonoids and moderate consumption of red wine might protect against atherosclerosis and thrombosis. One study suggests that daily intake of 100 mg of flavonoids through the diet may reduce the risk of developing morbidity and mortality due to coronary heart disease (CHD) by approximately 10%. This review summarizes dietary flavonoids with their sources and potential health implications in CVDs including various redox-active cardioprotective (molecular) mechanisms with antioxidant effects. Pharmacokinetic (oral bioavailability, drug metabolism), toxicological, and therapeutic aspects of dietary flavonoids are also addressed herein with future directions for the discovery and development of useful drug candidates/therapeutic molecules.     

Nuclear quantum effects in liquid water from path-integral simulations using an ab initio force-matching approach

We have applied path integral simulations, in combination with new ab initio based water potentials, to investigate nuclear quantum effects in liquid water. Because direct ab initio path integral simulations are computationally expensive, a flexible water model is parameterised by force-matching to density functional theory-based molecular dynamics simulations. Static and dynamic properties of liquid water at ambient conditions are presented and the role of nuclear quantum effects, exchange-correlation functionals and dispersion corrections are discussed in regards to reproducing the experimental properties of liquid water.     

Can trimethylamine-N-oxide act to influence the self-aggregation of tert-butyl alcohol?

We report classical molecular dynamics simulation studies of aqueous solution consisting of water, tert-butyl alcohol (TBA) and trimethylamine-N-oxide (TMAO). In spite of the fact that both TBA and TMAO molecules have very similar geometry with hydrophobic and hydrophilic groups, they behave very differently in aqueous solutions. Our aim is to see the role of TMAO on the self-aggregation (or association) of TBA molecules. We observe that, TMAO acts to postpone the aggregation of TBA molecules (takes place via the hydrophobic ends) to some extent. Addition of 0.10 mole fraction of TMAO shifts the aggregation concentration of TBA from x_tba = 0.025 to x_tba = 0.06. From the excess coordination number, calculation it is noticed that up to x_tba = 0.06, TBA molecules are favourably solvated by TMAO by replacing water molecules from TBA solvation shell but above this concentration, TBA–TMAO interaction decreases. This is further confirmed by water–TMAO interactions which shows a shift above x_tba = 0.06 indicating more preferred interactions between them. We also observe a noticeable increase in the water–water hydrogen bond life time in presence of TBA molecules indicating more structuring of water molecules.     

Temperature effects of Hamiltonian dark solitons on the stability of holographic solitons in a separate holographic–Hamiltonian soliton pair

We investigate theoretically the temperature effects on the evolution and stability of a separate holographic–Hamiltonian dark–dark or bright–dark soliton pair formed in an unbiased serial photorefractive crystal circuit. Our numerical results show that, for a stable dark–dark or bright–dark soliton pair originally formed in a crystal circuit at given temperatures, when the crystal in which formed a Hamiltonian dark soliton changes, the holographic dark or bright soliton supported by the other crystal tends to evolve into another stable soliton or experiences larger cycles of compression or breaks up into beam filaments or exhibit a common decaying process. The holographic dark soliton is more sensitive to the temperature change than the holographic bright one.     

Long Distance Electronic Effects on the Rotational Potential Barriers Around the Caromatic-Cethylenic Bond

A systematic study of the rotational activation free energy around the C_aromatic-C_ethylenic bond of para-substituted styrene systems is carried out in the present work from a quantum chemistry point of view.

Calculations of the rotational potential barriers in the AM1 approach are developed as function of the electron-donor groups localized on the aromatic ring. Based on these calculations and thermodynamical data, we predict changes in the activation free energy barriers due to the long distance electronic effects of the substituents in acetophenones, cinnamaldehydes and benzalketones according to the following equation:

Our results agree the experimental measurements registered up to date and the standard deviations are similar to experimental determinations.     

Photothermally Induced Bistability of Emission of Yb-doped Ca4NdO(BO3)3 Single Crystals

We report on studies of changes in the emission spectra (excited at 808 nm) of the Yb-doped Ca₄NdO(BO₃)₃ single crystals due to the photothermal effects caused by the pulsed Nd:YAG laser. Increase of the sample's surface temperature after laser treatment leads to significant enhancement of the 1040 to 1060 nm emission (ascribed to the Nd^{3+ 4}F_3/2 → ⁴I_9/2, ⁴I_11/2 transitions) and simultaneous decrease of the 975 to 1050 nm emission (corresponding to the Yb^{3+ 2}F_5/2 → ²F_7/2 transition). We explain such an increase of the Nd³⁺ luminescence by thermally activated Yb³⁺ → Nd³⁺ energy transfer.     

Measurement and Interpretation of Ethanol 13C Chemical Shifts Variations in Different Organic Solvents - Comparison with Aqueous Solvent

The carbon chemical shifts of ethanol are measured in varied aqueous and organic solvents. We determine the hydrogen bonding effect between alcohol and bases by correcting the experimental values from anisotropy and non specific medium effects.     

Vibrational Behaviour of the CrO3- 4 Anion in Different Crystalline Environments

The powder-infrared spectra of different crystalline compounds containing the tetrahedral Cro^3- ₄, anion have been recorded and analyzed with the aid of the site symmetry rules. In some cases Raman data are also reported. The effect of the different crystalline environments is discussed in detail and comparisons with isostructural phases are also made. A definitive assignment for the internal vibrations of the CrO^3- ₄, ion is proposed and a new set of force constants has been calculated fron a modified valence force field.     

Experimental gravity induced coexistence curve of methyl fluoride near the critical point

Abstract

The top part of the coexistence curve of methyl fluoride in the critical region has been determined first by direct observation of the disappearance of the meniscus of the fluid situated in a high-pressure light scattering cell and subsequently from the measured maximum depolarization ratio of an appreciable number of isochores close to the critical point. The experimental data obtained from direct observations yield a coexistence curve which nearly coincides with that found recently from pVT measurements. However, the data obtained from light scattering experiments describe a gravity induced coexistence curve which lies above the previous one and which shows a minimum at the critical point. The complete experimental data have been used to evaluate the critical parameters p_c, ρ_c and T_c and the critical exponent β.