Search results for "alloys"

Calcium isotopes as a biomarker for vascular calcification in chronic kidney disease

2022

AbstractCalcium balance is abnormal in adults with chronic kidney disease (CKD) and is associated with the development of vascular calcification. It is currently not routine to screen for vascular calcification in CKD patients. In this cross-sectional study, we investigate whether the ratio of naturally occurring calcium (Ca) isotopes, 44Ca and 42Ca, in serum could be used as a noninvasive marker of vascular calcification in CKD.We recruited 78 participants from a tertiary hospital renal center: 28 controls, 9 subjects with mild–moderate CKD, 22 undertaking dialysis and 19 who received a kidney transplant. For each participant, systolic blood pressure, ankle brachial index, pulse wave veloc…

Modification of halloysite lumen with dopamine derivatives as filler for antibiofilm coating

2023

Hypothesis: Development of nanocomposite coating with antibiofilm properties is of fundamental importance to efficient fight biofilm formation preventing infections in biomedical area. In this context, halloysite nanotubes (HNTs), biocompatible and low-cost clay mineral, have been efficiently used as filler for different polymeric matrices affording several nanocomposites with appealing antimicrobial properties. The modification of HNTs surfaces represents a valuable strategy to improve the utilization of the clay for biological purposes. Experiments: Herein, the covalent modification of the HNTs lumen with properly designed dopamine derivatives with different perfluoroalkyl chain length is…

Surface modification of AISI-304 steel by ZnO synthesis using cathodic cage plasma deposition

2021

Abstract Zinc-oxide (ZnO), a solid lubricant coating, can increase the wear resistance of steels by working as a self-lubricant. In this study, ZnO film is synthesized using the cathodic cage plasma deposition (CCPD) technique, using galvanized steel cathodic cage (steel cage with zinc coating). The effect of gas composition (H2 is added in Ar-O2) is investigated to optimize the film properties. The surface hardness is increased more than twice in each processing condition. The deposited film shows ZnO phases for samples treated with low hydrogen contents and a combination of ZnO and magnetite phase (Fe3O4) with higher hydrogen contents. The thickness of film reduced from 1.28 μm to 0.5 μm …

Effects of hydrostatic pressure on the thermoelectric properties of the ϵ-polytype of InSe, GaSe, and InGaSe2 semiconductor compounds: anab initiostu…

2017

Manganese(II) complexes of scorpiand-like azamacrocycles as MnSOD mimics.

2011

Mn(II) complexes of scorpiand-type azamacrocycles constituted by a tretrazapyridinophane core appended with an ethylamino tail including 2- or 4-quinoline functionalities show very appealing in vitro SOD activity. The observed behaviour is related to structural and electrochemical parameters.

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

2019

[EN] Based on the unique ability of defibrillated sepiolite (SEP) to form stable and homogeneous colloidal dispersions of diverse types of nanoparticles in aqueous media under ultrasonication, multicomponent conductive nanoarchitectured materials integrating halloysite nanotubes (HNTs), graphene nanoplatelets (GNPs) and chitosan (CHI) have been developed. The resulting nanohybrid suspensions could be easily formed into films or foams, where each individual component plays a critical role in the biocomposite: HNTs act as nanocontainers for bioactive species, GNPs provide electrical conductivity (enhanced by doping with MWCNTs) and, the CHI polymer matrix introduces mechanical and membrane pr…

Halloysite-Based Bionanocomposites

2017

Scientific research has been invigorated by a new class of biodegradable materials as alternatives to polymers derived from fossils. Such biomaterials can also offer economic advantages because they are derived from renewable resources. Several biopolymers (gelatin, chitin, chitosan, starch, pectin, cellulose and its modified versions, etc.) have been exploited to produce films and formulations. Their use is limited because of fast degradation, predominant hydrophilic character, and, in some cases, unsatisfactory mechanical properties. However, the properties of these polymers can be improved by using inorganic fillers such as additives. Halloysite nanotube is a promising green filler for t…

Colloidal stability of halloysite clay nanotubes

2019

Abstract The colloidal stability of halloysite clay nanotubes dispersion is reviewed showing the strategy and the mechanism to obtain stable systems in water and apolar solvents. The selective modification of halloysite inner/outer surfaces can be achieved by exploiting electrostatic interactions. The adsorption of anionic surfactants onto the halloysite cavity allows generating inorganic cylindrical micelles that can be separated from the solvent. On the other hand, the functionalization of halloysite shell by positively charged surfactants drives to obtain stable water-in-oil emulsions. The interactions with ionic and nonionic polymers alters the dispersability of halloysite due to electr…

Effects of halloysite content on the thermo-mechanical performances of composite bioplastics

2020

Abstract The aim of this study is the design and preparation of Mater-Bi/halloysite nanocomposite materials that could be employed as bioplastics alternative to the petroleum derived products. The biocomposite materials at variable halloysite content (from 0 to 30 wt%) were prepared by using the solvent casting method. We investigated the mechanical behaviour and the thermal properties of the prepared nanocomposites in order to estimate their suitability as biocompatible packaging materials. The thermo-mechanical characteristics were correlated to the nanocomposites' morphologies, which were studied by Scanning Electron Microscopy (SEM). As a general result, the physico-chemical performance…

The magnetic properties of ferrocene based macromolecules

1993

Abstract Magnetic susceptibility data for conjugatively linked biferrocenes and a methylene bridged ferrocene polymer are presented. In 9,10-di((2-ferrocenyl)vinyl)anthracene a rigid divinylanthracene bridge is connecting two ferrocene units, and the oxidation of both iron centers leads to an antiferromagnetic coupling. In contrast, ferromagnetic coupling between iron centers is indicated for 2,2'-cis,trans-di((2-ferrocenyl)vinyl)biphenyl, where a twist around the phenyl-phenyl bond in the divinylbiphenyl bridging molecule is likely to occur.