Reinforced Epoxy Composites Modified with Functionalized Graphene Oxide

The possibility of using graphene oxide as a modifying additive for polymer fiber-reinforced composites based on epoxy resin and basalt roving has been studied. The content of graphene oxide in the system has been experimentally selected, which has the best effect on the physico-mechanical properties of the obtained polymer composite material. The efficiency of the modification of the graphene oxide surface with APTES finishing additives and aminoacetic acid, which provides chemical interaction at the polymer matrix–filler interface, has been considered. The influence of graphene oxide and functionalizing additives on the polymer curing process was investigated using the thermometric method and differential scanning calorimetry.

Anti-adhesive membranes based on crosslinked carboxymethyl cellulose

In recent times, new anti-adhesion devices including devices based on carboxymethyl cellulose (CMC), which have “barrier” effect are being developed and actively introduced into surgical practice. The “barrier” should be completely resorbed after the time required to healing the morphofunctional integrity of the injured peritoneum, be economically available and easy to use (including laparoscopic technologies). But the time when the CMC is in the body is insufficient to prevent the formation of adhesions, particularly in the presence of non-absorbable rigid implants. The reactive functional groups in CMC allow to transform the CMC-macromolecule into a spatial structure. For this are required the using of bifunctional (bicarboxylic or aminocarboxylic) acids and the transform of a part of the carboxyl groups from the Na-form to the hardly soluble H-form, i.e., it is necessary to crosslink CMC-macromolecules. Adipic acid and glutaric acid, aminoacetic acid and amino capronic acid used are linking agents. The influence of modification parameters on the degree of polymers swelling in water is studied. As a result, to obtain membranes designed for the treatment of adhesive disease, it is recommended to use additives in CMC of bifunctional compounds.

A novel adsorbent features like EDTA synthesized in situ by chemically modified cellulose and its behavior in metal ions adsorption from aqueous solution

This paper describes the synthesis of a novel chelating material derived from cellulose, and its heavy metal ions adsorption behavior from aqueous solution. The first section of this paper reports the chemical grafting of cellulose, that aminoacetic acid groups were grafted into the cellulose, resulted a novel yet unreported modified cellulose derivative N,N-(dicarboxymethylaminoethyl, carboxymethyl) aminoethylamine carboxymethyl cellulose amide. This obtained adsorbent was characterized by elemental analysis, infrared spectroscopy (IR) and Solid State Nuclear Magnetic Resonance (SSNMR) 13 C NMR spectroscopy. In the second section, adsorption behaviors such as kinetic study, adsorption isotherms of the adsorbent for Cu 2+ and Pb 2+ single metal ions from aqueous solution, and adsorption capacity for Ba 2+ , Mg 2+ , Mn 2+ , Co 2+ , Zn 2+ , Pb 2+ , Ni 2+ and Cu 2+ , and the competitive adsorption of this adsorbent between ions were evaluated by ICP spectroscopy.

Reaction Mechanism of 2-Amido-2-Aminoacetic Acid-Formation from Amides and 2-Iminoacetic Acid: A DFT-study and Wavefunction Analysis

<p> Based on a study of Wei Zeng et. al.[7], where the synthesis of <i>gem</i>-diamino acid esters from 2-iminoacetic acid esters and amides, with various N- and C-substituents, respectively, is reported, a modeled reaction, where the latter substituents were replaced by H, was simulated by means of DFT. A reasonable reaction mechanism was found for the formation of 2-amido-2-aminoacetic acid from formamide and 2-iminoacetic acid. Moreover, possible side reactions were simulated and discussed.</p>

Reaction Mechanism of 2-Amido-2-Aminoacetic Acid-Formation from Amides and 2-Iminoacetic Acid: A DFT-study and Wavefunction Analysis

<p> Based on a study of Wei Zeng et. al.[7], where the synthesis of <i>gem</i>-diamino acid esters from 2-iminoacetic acid esters and amides, with various N- and C-substituents, respectively, is reported, a modeled reaction, where the latter substituents were replaced by H, was simulated by means of DFT. A reasonable reaction mechanism was found for the formation of 2-amido-2-aminoacetic acid from formamide and 2-iminoacetic acid. Moreover, possible side reactions were simulated and discussed.</p>

Reaction Mechanism of 2-Amido-2-Aminoacetic Acid-Formation from Amides and 2-Iminoacetic Acid: A DFT-study and Wavefunction Analysis

<p> Based on a study of Wei Zeng et. al.[7], where the synthesis of <i>gem</i>-diamino acid esters from 2-iminoacetic acid esters and amides, with various N- and C-substituents, respectively, is reported, a modeled reaction, where the latter substituents were replaced by H, was simulated by means of DFT. A reasonable reaction mechanism was found for the formation of 2-amido-2-aminoacetic acid from formamide and 2-iminoacetic acid. Moreover, possible side reactions were simulated and discussed.</p>

Screening of Heteroaromatic Scaffolds against Cystathionine Beta-Synthase Enables Identification of Substituted Pyrazolo[3,4-c]Pyridines as Potent and Selective Orthosteric Inhibitors

Cystathionine β-synthase (CBS) is a key enzyme in the production of the signaling molecule hydrogen sulfide, deregulation of which is known to contribute to a range of serious pathological states. Involvement of hydrogen sulfide in pathways of paramount importance for cellular homeostasis renders CBS a promising drug target. An in-house focused library of heteroaromatic compounds was screened for CBS modulators by the methylene blue assay and a pyrazolopyridine derivative with a promising CBS inhibitory potential was discovered. The compound activity was readily comparable to the most potent CBS inhibitor currently known, aminoacetic acid, while a promising specificity over the related cystathionine γ-lyase was identified. To rule out any possibility that the inhibitor may bind the enzyme regulatory domain due to its high structural similarity with cofactor s-adenosylmethionine, differential scanning fluorimetry was employed. A sub-scaffold search guided follow-up screening of related compounds, providing preliminary structure-activity relationships with respect to requisites for efficient CBS inhibition by this group of heterocycles. Subsequently, a hypothesis regarding the exact binding mode of the inhibitor was devised on the basis of the available structure-activity relationships (SAR) and a deep neural networks analysis and further supported by induced-fit docking calculations.

Inoculation with Aspergillus aculeatus Alters the Performance of Perennial Ryegrass under Phosphorus Deficiency

Phosphorus (P) is an essential nutrient element that is necessary for plant growth and development. However, most of the P exists in insoluble form. Aspergillus aculeatus has been reported to be able to solubilize insoluble forms of P. Here, to investigate the P-solubilizing effect of A. aculeatus on the performance of perennial ryegrass (Lolium perenne) under P-deficiency stress, we created four treatment groups: control [i.e., no Ca3(PO4)2 or A. aculeatus], A. aculeatus only (F), Ca3(PO4)2 and Ca3(PO4)2 + A. aculeatus [Ca3(PO4)2 + F] treatment, and Ca3(PO4)2 at concentrations of 0 and 3 g per pot (0.5 kg substrate per pot). In our results, the liquid medium inoculated with A. aculeatus exhibited enhanced soluble P and organic acid content (tartaric acid, citric acid, and aminoacetic acid) accompanied with lower pH, compared with the noninoculated regimen. Furthermore, A. aculeatus also played a primary role in increasing the soluble P content of substrate (1 sawdust: 3 sand), the growth rate, turf quality, and photosynthetic capacity of the plant exposed to Ca3(PO4)2 + F treatment, compared with other groups. Finally, in perennial ryegrass leaves, there was a dramatic increase in the valine, serine, tyrosine, and proline contents, and a remarkable decline in the glutamic acid, succinic acid, citric acid, and fumaric acid contents in the Ca3(PO4)2 + F regimen, compared with other groups. Overall, our results suggested that A. aculeatus may play a crucial role in the process of solubilizing Ca3(PO4)2 and modulating perennial ryegrass growth under P-deficiency stress.