Phase structure and electrochemical characteristics of CaNi4.7Mn0.3 hydrogen storage alloy by mechanical alloying

Journal of Solid State Electrochemistry - In this paper, we study systematically the effect of ball/powder weight ratio on the morphological, structural, and electrochemical properties of...     

Acrolein and Copper as Competitive Effectors of α-Synuclein

Mounting evidence supports the role of amyloidogenesis, oxidative stress, and metal dyshomeostasis in the development of neurodegenerative disorders. Parkinson's Disease is characterized by α-synuclein (αSyn) accumulation and aggregation in brain regions, also promoted by Cu²⁺. αSyn is modified by reactive carbonyl species, including acrolein (ACR). Notwithstanding these findings, the interplay between ACR, copper, and αSyn has never been investigated. Therefore, we explored more thoroughly the effects of ACR on αSyn using an approach based on LC-MS/MS analysis. We also evaluated the influence of Cu²⁺ on the protein carbonylation and how the ACR modification impacts the Cu²⁺ binding and the production of Reactive Oxygen Species (ROS). Finally, we investigated the effects of ACR and Cu²⁺ ions on the αSyn aggregation by dynamic light scattering and fluorescence assays. Cu²⁺ regioselectively inhibits the modification of His50 by ACR, the carbonylation lowers the affinity of His50 for Cu²⁺ and ACR inhibits αSyn aggregation both in the presence and in the absence of Cu²⁺.     

Physical Evidence of Stress-Induced Conformational Changes in Polymers

Background

Polymer mechanics and characterization is an active area of research where a keen effort is directed towards gaining a predictive and correlative relationship between the applied loads and the specific conformational motions of the macromolecule chains.

Objective

Therefore, the objective of this research is to introduce the preliminary results based on a novel technique to in situ probe the mechanical properties of polymers using non-invasive, non-destructive, and non-contact terahertz spectroscopy.

Methods

A dielectric elastomer actuator (DEA) structure is used as the loading mechanism to avoid obscuring the beam path of transmission terahertz time-domain spectroscopy. In DEAs, the applied voltage results in mechanical stresses under the active electrode area with far-reaching stretching in the passive area. Finite element analysis is used to model and simulate the DEA to quantify the induced stresses at the observation site over a voltage range spanning from 0 V to 3000 V. Additionally, a novel analysis technique is introduced based on the Hilbert-Huang transform to exploit the time-domain signals of the ultrathin elastomeric film and to defy the limits set forth by the current state-of-the-art analysis techniques.

Results

The computational result shows a nonlinear relationship between the effective stresses and the applied voltage. Analysis of the terahertz time-domain signals shows a shift in the delay times and a decrease in signal peak amplitudes, whereas these characteristics are implicitly related to the change in the index of refraction.

Conclusions

In all, the results evidentially signify the interrelationship between the conformational changes and applied mechanical stress.

     

On von Neumann regular elements in <Emphasis Type="Italic">f</Emphasis>-rings

Let B be an Archimedean reduced f-ring. A positive element \({\omega}\) in B is said to satisfy the property \({(\ast)}\) if for every f-ring A with identity e and every \({\ell}\)-group homomorphism \({\gamma : A \rightarrow B}\) with \({\gamma(e) = \omega}\), there exists a unique \({\ell}\)-ring homomorphism \({\rho: B \rightarrow B}\) such that \({\gamma = \omega \rho}\) and \({\rho(e)^{\perp \perp} = \omega^{\perp \perp}}\). Boulabiar and Hager proved that any (positive) von Neumann regular element in B satisfies the property \({(\ast)}\) and proved that the converse holds in the C(X)-case. In this regard, they asked about this converse in the general case. Our main purpose in this note is to prove, via a counter-example, that the converse in question fails in general. In addition, we shall take the opportunity to extend the direct result obtained by Boulabiar and Hager, and to get the C(X)-case we were talking about in an easier way.     

Filling the equatorial garland of uranyl ion: its content and limitations

Crystal structure determinations on the uranyl ion complexes [H₂N(CH₃)₂]₂[UO₂(bpdc)₂], (1), (bpdc?=?2,2′-bipyridine-3,3′-dicarboxylate), [pyH]₂[UO₂(btfac)(NO₃)₂](NO₃), (2), (btfac?=?1-phenyl-4,4,4-trifluorobutane-1,3-dionate), [H₂dabco][UO₂(nta)]₂·3H₂O, (3), (dabco?=?1,4-diazabicyclo[2.2.2]octane; nta?=?nitrilotriacetate) and [Ni(cyclam)UO₂(edta)]^.2H₂O, (4), (cyclam?=?1,4,8,11-tetrazacyclotetradecane; edta?=?ethylenediaminetetraacetate) have provided further examples of U(VI) in tetragonal-, pentagonal and hexagonal-bipyramidal coordination environments. Consideration of each structure within the context of those of known relatives has been used to assess the influence of factors in addition to repulsions within the primary coordination sphere on the equatorial coordination number of U(VI).

     

Action of Hydrazines on 2‐(2‐Oxindolin‐3‐ylidene)malononitrile, (E,Z)‐Ethyl 2‐cyano‐2‐(2‐oxindolin‐3‐ylidene)acetate and Isatin‐β‐thiosemicarbazone as a Source of Spiro Indoline‐pyrazole Systems

2‐(2‐Oxindolin‐3‐ylidene)malononitrile ( 1a ) or (E,Z)‐ethyl 2‐cyano‐2‐(2‐oxindolin‐3‐ylidene)acetate ( 1b ) or isatin‐β‐thiosemicarbazone ( 1c ) undergoes reactions with prototype hydrazine hydrate itself and some of its simple congeners to give hydrazone derivatives bearing indoline‐2‐one moiety ( 2 ). The hydrazone derivatives ( 2 ) when heated with acetyl acetone or ethyl acetoacetate in dry pyridine afforded the spiro indoline derivatives ( 3a , 3b ). Also, cinnoline derivative ( 9 ) is obtained by action of hydrazine hydrate on the N‐acetyl derivative of ( 6a ). The structures of the newly synthesized compounds were evaluated by IR, ¹H‐NMR spectroscopy, mass spectra and elemental analyses.     

Utility of 4‐Benzylidene‐2‐phenyl‐5(4H)‐oxazolone in Synthesis of Triazine,Oxadiazole and Imidazole Derivatives of Anticipated Biological Activity

Treatment of oxazolone 1 with hydrazine hydrate at room temperature gave the (Z)‐configurated isomer hydrazide (Z)‐ 3 (high yield). However, refluxing 1 with hydrazine hydrate yielded the (E)‐configurated isomer hydrazide (E)‐ 2 (low yield).The hydrazide derivative (Z)‐ 3 has been utilized as synthon for the synthesis of 1,2,4‐triazinone, imidazolone, and oxadiazole derivatives through appropriate routes. The thiosemicarbazide and semicarbazide derivatives are synthesized by different routes. The structures of the new compounds were established on the basis of IR, ¹H‐NMR, mass spectral data, and elemental analysis.     

Stochastic optimization in supply chain networks: averaging robust solutions

We propose a novel robust optimization approach to analyze and optimize the expected performance of supply chain networks. We model uncertainty in the dema     

A Struwe Type Decomposition Result for a Singular Elliptic Equation on Compact Riemannian Manifolds

On a compact Riemannian manifold,we prove a decomposition theorem for arbitrarily bounded energy sequence of solutions of a singular elliptic equation.     

One-pot preparation of 2-(alkyl)arylbenzoselenazoles from the corresponding N-(acetyl)benzoyl-2-iodoanilines via a microwave-assisted methodology

We report here the first example of a one-pot synthesis of 2-(alkyl)arylbenzoselenazoles from N-(acetyl)benzoyl-2-iodoanilines. The reaction was carried out in the presence of Woollins’ reagent under microwave irradiation and resulted in moderate to good yields.