The arrhenius factors for some six-center unimolecular reactions

The Pyrolysis of ethyl formate has been carried out in the temperature range 557°–630° and the rate expression k = 10^12.34 e^{?48,100±500/RT} sec^?1 was obtained, in agreement with the prediction of O'Neal and Benson [1]. Calculated Arrhenius A-factors and experimental rate constants have been used to obtain the activation energies for the decomposition of the following compounds by the six-center molecular mechanism (in kcal/mole): 2-pentanone 59; methoxyacetone, 58; 2,4-pentanedione, 51; methyl butyrate, ≥ 70; 1-heptene, 54, and 4-methyl-1-hexene, 54–55.     

Laser-generated ultrashort multimegagauss magnetic pulses in plasmas

We demonstrate ultrashort (6 ps), multimegagauss (27 MG) magnetic pulses generated upon interaction of an intense laser pulse (10(16) W cm(-2), 100 fs) with a solid target. The temporal evolution of these giant fields generated near the critical layer is obtained with the highest resolution reported thus far. Particle-in-cell simulations and phenomenological modeling is used to explain the results. The first direct observations of anomalously rapid damping of plasma shielding currents produced in response to the hot electron currents penetrating the bulk plasma are presented.     

Kinetics of the “a” and “b” band emissions of mercury excimers with added gases

The kinetics of the “a” and “b” band emissions arising from the ¹Σ ← ³O_u and ¹Σ ← ³l_u transitions of the diatomic mercury molecule at λ_max ～ 4850 Å and 3350 Å, respectively, have been studied at low concentrations of mercury in the presence of N₂, C₂H₆, C₃H₈, and N₂O. Rate constant values have been obtained for the following reactions of the excimer molecule: Hg₂(³l_u) + N₂ → Hg₂(³O_u) + N₂ and Hg₂(³O_u) + RH → Hg₂(¹Σ) + RH, where RH = C₂H₆ or C₃H₈. From a consideration of the detailed kinetics of band emissions, it was also possible to derive rate constants for the quenching reactions of Hg(³P₀) atoms. These values are in reasonable agreement with those obtained previously from monitoring atom concentrations directly by 4047 Å absorbiometry.     

Synthesis,Biological Evaluation,and Molecular Docking Studies of Some N‐thiazolyl Hydrazones and Indenopyrazolones

Two new series of N‐thiazolyl hydrazones ( 3a – h ) and indenopyrazolones ( 4a – h ) were synthesized by the reaction of various 2‐acyl‐(1H)‐indene‐1,3(2H)‐diones, thiosemicarbazide, and phenacyl bromide/substituted phenacyl bromides. The in vitro antimicrobial activity of these synthesized compounds was assayed against four bacteria, namely, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, and two fungi, namely, Candida albicans and Aspergillus niger, by employing serial dilution method. Ciprofloxacin and fluconazole were used as antibacterial and antifungal reference drugs, respectively. Results of antimicrobial assay showed that the tested compounds have broad range of activity. The compounds 3h and 4a against C. albicans displayed more potency than fluconazole whereas 3b and 3c against B. subtilis showed activity comparable with ciprofloxacin. The synthesized indenopyrazolones ( 4a – h ) were evaluated for their in vitro antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging assay using ascorbic acid as reference. Compound 4b exhibited the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging with IC₅₀ value 33.14 μg/mL. The observed results of antimicrobial activity were supported by molecular docking study performed to understand the binding interaction of hydrazones ( 3a – h ) and indenopyrazolones ( 4a – h ) with lanosterol 14α‐demethylase.     

Zeolite-Hy : A Selective And Efficient Catalyst For The Alcoholyses Of Various Alcohols

An efficient and selective method for the conversion of various alcohols into their corresponding ethers in the presence of zeolite under sorvolytic condition is described. The reaction proceeds efficiently at ambient pressure in high yields.     

Disordered proteins and network disorder in network descriptions of protein structure, dynamics and function: hypotheses and a comprehensive review

During the last decade, network approaches became a powerful tool to describe protein structure and dynamics. Here we review the links between disordered proteins and the associated networks, and describe the consequences of local, mesoscopic and global network disorder on changes in protein structure and dynamics. We introduce a new classification of protein networks into 'cumulus-type', i.e., those similar to puffy (white) clouds, and 'stratus-type', i.e., those similar to flat, dense (dark) low-lying clouds, and relate these network types to protein disorder dynamics and to differences in energy transmission processes. In the first class, there is limited overlap between the modules, which implies higher rigidity of the individual units; there the conformational changes can be described by an 'energy transfer' mechanism. In the second class, the topology presents a compact structure with significant overlap between the modules; there the conformational changes can be described by 'multi-trajectories'; that is, multiple highly populated pathways. We further propose that disordered protein regions evolved to help other protein segments reach 'rarely visited' but functionally-related states. We also show the role of disorder in 'spatial games' of amino acids; highlight the effects of intrinsically disordered proteins (IDPs) on cellular networks and list some possible studies linking protein disorder and protein structure networks.     

Dynamically tuned coupled-resonator delay lines can be nearly dispersion free

We investigate dispersion effects in dynamically tuned, coupled-resonator delay lines. Provided that the system is tuned to a zero-bandwidth state, a signal can be delayed indefinitely with almost no dispersion. We present a theoretical analysis of such a light-stopping system and verify the results using numerical simulations.     

Diorganotin(IV) derivatives of N-phthaloyl amino acids

Twentyfour complexes of the general formulae (R₂SnL₂ and R₂(L)SnOSn(L)R₂ (L = N-phthaloyl derivative of l-leucine, dl-alanine and l-phenylalanine; R = CH₃, C₅H₅, n-C₄H₉) and n-C₈H₁₇) have been prepared by reacting ligand and dialkyltin(IV) oxide in 2/1 and 1/1 (ligand/metal) molar ratio. These complexes have been characterised by elemental analysis and structures assigned with the help of infrared, ¹H NMR and ¹¹⁹Sn Mössbauer spectroscopy. These data support six-coordinated distorted octahedral structures with two alkyl groups in trans positions.     

Paraquat induces oxidative stress, neuronal loss in substantia nigra region and Parkinsonism in adult rats: Neuroprotection and amelioration of symptoms by water-soluble formulation of Coenzyme Q10

Background  

Parkinson's disease, for which currently there is no cure, develops as a result of progressive loss of dopamine neurons in the brain; thus, identification of any potential therapeutic intervention for disease management is of a great importance.     

Controlling coherent and incoherent plasma emissions: the role of electron plasma waves

We present results of our two-pulse time resolved measurements of second harmonic and hard X-ray generation in the interaction of an intense (10¹⁶ Wcm^-2, 100 fs, 800 nm) laser with a preplasma generated on a solid surface. The time-resolved study as a function of both plasma scale length and laser polarization brings out interesting features of electron plasma wave dynamics. The harmonic and X-ray emission show contrary behavior and we interpret the results in terms of Resonance Absorption and Wave-Breaking mechanisms. Simple optimization of the scale length of the preplasma and the polarization parameters of the main pulse results in significant enhancements, up to a factor of 100 for X-rays and 10 for the second harmonic respectively. These results can help us understand the governing mechanisms for higher harmonic generation and for fast particle generation, aiding the development of more efficient sources. PACS 52.35.Fp; 42.65.Ky; 52.38.Ph