Filters compatible with isomorphism testing

Like the lower central series of a nilpotent group, filters generalize the connection between nilpotent groups and graded Lie rings. However, unlike the case with the lower central series, the associated graded Lie ring may share few features with the original group: e.g. the associated Lie ring can be trivial or arbitrarily large. We determine properties of filters such that every isomorphism between groups is induced by an isomorphism between graded Lie rings.     

Synchronized Esterification and Transesterification of Jatropha Curcas Using Ferric Sulfate Modified Snail Shells As a Bi-Functional Catalyst: A Box-Behken Optimization Approach

Russian Journal of Applied Chemistry - The study is focused on modelling and optimizing the process parameters on the production of biodiesel from Jatropha Curcas oil using achantinoidea shell...     

Elucidating the Influence of Electrical Potentials on the Formation of Charged Oligopeptide Self-Assembled Monolayers on Gold

Self-assembled monolayers (SAMs) based on oligopeptides have garnered immense interest for a wide variety of innovative biomedical and electronic applications. However, to exploit their full potential, it is necessary to understand and control the surface chemistry of oligopeptides. Herein, we report on how different electrical potentials affect the adsorption kinetics, stability and surface coverage of charged oligopeptide SAMs on gold surfaces. Kinetic analysis using electrochemical surface plasmon resonance (e-SPR) reveals a slower oligopeptide adsorption rate at more positive or negative electrical potentials. Additional analysis of the potential-assisted formed SAMs by X-ray photoelectron spectroscopy demonstrates that an applied electrical potential has minimal effect on the packing density. These findings not only reveal that charged oligopeptides exhibit a distinct potential-assisted assembly behaviour but that an electrical potential offers another degree of freedom in controlling their adsorption rate.     

Cyclic Disulfide Liposomes for Membrane Functionalization and Cellular Delivery

Liposomes are effective therapeutic delivery nanocarriers due to their ability to encapsulate and enhance the pharmacokinetic properties of a wide range of therapeutics. Two primary areas in which improvement is needed for liposomal drug delivery is to enhance the ability to infiltrate cells and to facilitate derivatization of the liposome surface. Herein, we report a liposome platform incorporating a cyclic disulfide lipid (CDL) for the dual purpose of enhancing cell entry and functionalizing the liposome membrane through thiol-disulfide exchange. In order to accomplish this, CDL-1 and CDL-2 , composed of lipoic acid (LA) or asparagusic acid (AA) appended to a lipid scaffold, were designed and synthesized. A fluorescence-based microplate immobilization assay was implemented to show that these compounds enable convenient membrane decoration through reaction with thiol-functionalized small molecules. Additionally, fluorescence microscopy experiments indicated dramatic enhancements in cellular delivery when CDLs were incorporated within liposomes. These results demonstrate that multifunctional CDLs serve as an exciting liposome system for surface decoration and enhanced cellular delivery.     

Hydrogen oxidation near the second explosion limit in a flow reactor

This work investigates the oxidation of hydrogen near its second explosion limit in a turbulent flow reactor at pressures of 1 to 8 bar, temperatures of 950 K and an equivalence ratio of 0.035. The concentrations of H₂, O₂ and H₂O are measured along the reactor and simulated using several kinetic models from the literature. These experiments demonstrate evident negative pressure dependence from roughly 1 to 4 bar, with further increases in pressure resuming its positive impact on reaction rates. The simulated and measured species concentrations along the reactor generally agree within a factor of 2.Further investigation is then conducted to measure the rate coefficient of reaction H + O₂ (+ M) = HO₂ (+M) (R2), which is one of the most sensitive reactions in hydrogen's oxidation chemistry at these conditions. This investigation is conducted by using nitric oxide (NO) as a dopant and measuring the resulting, quasi-steady-state concentrations of NO₂. The rate coefficients are obtained at 950 – 1010 K. Combined with literature results, an Arrhenius expression is proposed, $k_{2,0}^{N_2}$ = 4.50 × 10²⁰ (T/K)^?1.73 [cm⁶ mole^?2 s^?1], for the reaction rate at the low-pressure limit over 500 K – 2000 K with N₂ as the bath gas. Simulations using the models from the literature with the proposed Arrhenius expression for this reaction then demonstrate improved agreement with the experiments.     

Reactive Oxygen Species (ROS) Activated Liposomal Cell Delivery using a Boronate-Caged Guanidine Lipid

We report boronate-caged guanidine-lipid 1 that activates liposomes for cellular delivery only upon uncaging of this compound by reactive oxygen species (ROS) to produce cationic lipid products. These liposomes are designed to mimic the exceptional cell delivery properties of cell-penetrating peptides (CPPs), while the inclusion of the boronate cage is designed to enhance selectivity such that cell entry will only be activated in the presence of ROS. Boronate uncaging by hydrogen peroxide was verified by mass spectrometry and zeta potential (ZP) measurements. A microplate-based fluorescence assay was developed to study the ROS-mediated vesicle interactions between 1 -liposomes and anionic membranes, which were further elucidated via dynamic light scattering (DLS) analysis. Cellular delivery studies utilizing fluorescence microscopy demonstrated significant enhancements in cellular delivery only when 1 -liposomes were incubated with hydrogen peroxide. Our results showcase that lipid 1 exhibits strong potential as an ROS-responsive liposomal platform for targeted drug delivery applications.