Phenylalanine Losses in Neutralization Dialysis: Modeling and Experiment.

A non-steady state mathematical model of an amino acid (phenylalanine (Phe)) and mineral salt (NaCl) solution separation by neutralization dialysis (ND) carried out in a batch mode is proposed. The model takes into account the characteristics of membranes (thickness, ion-exchange capacity, and conductivity) and solutions (concentration, composition). As compared to previously developed models, the new one considers the local equilibrium of Phe protolysis reactions in solutions and membranes and the transport of all the phenylalanine forms (zwitterionic, positively and negatively charged) through membranes.

Uptake, tissue distribution and toxicological effects of environmental microplastics in early juvenile fish Dicentrarchus labrax.

As the smallest environmental microplastics (EMPs), even at nanoscale, are increasingly present in the environment, their availability and physical and chemical effects on marine organisms are poorly documented. In the present study, we primarily investigated the uptake and accumulation of a mixture of environmental microplastics (EMPs) obtained during an artificial degradation process in early-juvenile sea bass (Dicentrarchus labrax). Moreover, we evaluated their hazardous effects using biochemical markers of cytotoxicity.

Molecular "wiring" of plasma amine oxidase: Green and enzyme friendly approaches.

The study describes two approaches to enhance oxidoreductases. Both target molecular "wiring" of enzymes using green processes. The concepts were tested on plasma amine oxidase (PAO).

Fabrication of large pore mesoporous silica microspheres by salt-assisted spray-drying method for enhanced antibacterial activity and pancreatic cancer treatment.

Large-pore mesoporous silica (LPMS) microspheres with tunable pore size have received intensive interest in the field of drug delivery due to their high storage capacity and fast delivery rate of drugs. In this work, a facile salt-assisted spray-drying method has been developed to fabricate LPMS microspheres using continuous spray-drying of simple inorganic salts as pore templates and colloidal SiO nanoparticles as building blocks, followed by washing with water to remove the templates. More importantly, the porosity of the LPMS microspheres can be finely tuned by adjusting the furnace temperature and relative concentration of the salt to SiO, which could lead to optimal pharmaceutical outcomes.

Antibiotic loading and development of antibacterial capsules by using porous CaCO microparticles as starting material.

Porous calcium carbonate (CaCO) particles have been shown to be highly advantageous for biological applications, mainly due to their large surface area and their stability in physiological media. Also, developing appropriate antibacterial materials presenting the benefits of non-formation of harmful compounds is of major interest. Two characteristics of CaCO particles were investigated herein: (i) antibiotic-loading capacity and (ii) the possibility of using CaCO particles as a template for the fabrication of biocapsules presenting inherent antibacterial capacity.

Aerosol-Assisted Synthesis of Tailor-Made Hollow Mesoporous Silica Microspheres for Controlled Release of Antibacterial and Anticancer Agents.

Hollow mesoporous silica microsphere (HMSM) particles are one of the most promising vehicles for efficient drug delivery owing to their large hollow interior cavity for drug loading and the permeable mesoporous shell for controlled drug release. Here, we report an easily controllable aerosol-based approach to produce HMSM particles by continuous spray-drying of colloidal silica nanoparticles and Eudragit/Triton X100 composite (EUT) nanospheres as templates, followed by template removal. Importantly, the internal structure of the hollow cavity and the external morphology and the porosity of the mesoporous shell can be tuned to a certain extent by adjusting the experimental conditions (i.

Mechanistic Investigation of a Hybrid Zn/V O Rechargeable Battery with a Binary Li /Zn Aqueous Electrolyte.

Low-cost, easily processable, and environmentally friendly rechargeable aqueous zinc batteries have great potential for large-scale energy storage, which justifies their receiving extensive attention in recent years. An original concept based on the use of a binary Li /Zn aqueous electrolyte is described herein for the case of the Zn/V O system. In this hybrid, the positive side involves mainly the Li insertion/deinsertion reaction of V O , whereas the negative electrode operates according to zinc dissolution-deposition cycles.

Bilayered Potassium Vanadate K V O as Superior Cathode Material for Na-Ion Batteries.

A bilayered potassium vanadate K V O (KVO) is synthesized by a fast and facile synthesis route and evaluated as a positive electrode material for Na-ion batteries. Half the potassium ions can be topotactically extracted from KVO through the first charge, allowing 1.14 Na ions to be reversibly inserted.

Chitosan based self-assembled nanocapsules as antibacterial agent.

Creating an appropriate antibacterial disinfection system without forming any harmful compounds is still a major challenge and calls for new technologies for efficient disinfection and microbial control. Towards this aim, we report on the elaboration of biodegradable and biocompatible polymeric nanocapsules, also called hollow nanoparticles, for potential applications in antibiotic therapy. These nanomaterials are based on the self-assembly of charged polysaccharides, namely chitosan and alginate, onto gold nanoparticles as a sacrificial matrix (60 nm).

Unraveling the Structure-Raman Spectra Relationships in VO Polymorphs via a Comprehensive Experimental and DFT Study.

Vanadium pentoxide polymorphs (α-, β-, γ'-, and ε'-VO) have been studied using the Raman spectroscopy and quantum-chemical calculations based on density functional theory. All crystal structures have been optimized by minimizing the total energy with respect to the lattice parameters and the positions of atoms in the unit cell. The structural optimization has been followed by the analysis of the phonon states in the Γ-point of the Brillouin zone, and the analysis has been completed by the computation of the Raman scattering intensities of the vibrational modes of the structures.

Porous structure of ion exchange membranes investigated by various techniques.

A comparative review of various techniques is provided: mercury intrusion porosimetry, nitrogen sorption porosimetry, differential scanning calorimetry (DSC)-based thermoporosimetry, and standard contact porosimetry (SCP), which allows determining pore volume distribution versus pore radius/water binding energy in ion-exchange membranes (IEMs). IEMs in the swollen state have a labile structure involving micro-, meso- and macropores, whose size is a function of the external water vapor pressure. For such materials, the most appropriate methods for quantifying their porosity are DSC and SCP.

Nanoporous Polymer Films of Cyanate Ester Resins Designed by Using Ionic Liquids as Porogens.

Novel nanoporous film materials of thermostable cyanate ester resins (CERs) were generated by polycyclotrimerization of dicyanate ester of bisphenol E in the presence of varying amounts (from 20 to 40 wt%) of an ionic liquid (IL), i.e., 1-heptylpyridinium tetrafluoroborate, followed by its quantitative extraction after complete CER network formation.

Effect of Isovalent Substitution on the Electronic Structure and Thermoelectric Properties of the Solid Solution α-AsTeSe (0 ≤ x ≤ 1.5).

We report on the influence of Se substitution on the electronic band structure and thermoelectric properties (5-523 K) of the solid solution α-AsTeSe (0 ≤ x ≤ 1.5). All of the polycrystalline compounds α-AsTeSe crystallize isostructurally in the monoclinic space group C2/m (No.

Simultaneous Au Extraction and In Situ Formation of Polymeric Membrane-Supported Au Nanoparticles: A Sustainable Process with Application in Catalysis.

A polymeric membrane-supported catalyst with immobilized gold nanoparticles (AuNPs) was prepared through the extraction and in situ reduction of Au salts in a one-step strategy. Polymeric inclusion membranes (PIMs) and polymeric nanoporous membranes (PNMs) were tested as different membrane-support systems. Transport experiments indicated that PIMs composed of cellulose triacetate, 2-nitrophenyloctyl ether, and an aliphatic tertiary amine (Adogen 364 or Alamine 336) were the most efficient supports for Au extraction.

Design of functionalized biodegradable PHA-based electrospun scaffolds meant for tissue engineering applications.

Modification of electrospun nanofibrous poly(3-hydroxyalkanoate) (PHA)-based mats was implemented through two routes to obtain biomimetic scaffolds meant for tissue engineering applications. The first strategy relied on a physical functionalization of scaffolds thanks to an original route which combined both electrospinning and electrospraying, while the second approach implied the chemical modification of fiber surface via the introduction of reactive functional groups to further conjugate bioactive molecules. The degree of glycidyl methacrylate grafting on PHA reached 20% after 300s under photoactivation.

Polymorphism in Thermoelectric As2Te3.

Metastable β-As2Te3 (R3̅m, a = 4.047 Å and c = 29.492 Å at 300 K) is isostructural to layered Bi2Te3 and is known for similarly displaying good thermoelectric properties around 400 K.

Synthesis of 2,3-di- and 2,2,3-trisubstituted-3-methoxycarbonyl-γ-butyrolactones as potent antitumor agents.

Various 2,3-substituted γ-butyrolactones have been synthesized by three-component reaction of aryl bromides, dimethyl itaconate and carbonyl compounds. The in vitro cytotoxic activity of these products was evaluated against a representative panel of cancer cell lines (KB, HCT116, MCF7, MCF7R, PC3, SK-OV3, HL60 and HL60R). One compound (4x) displays a good anti-proliferative activity with IC50 in the sub-micromolar range.

Nanoalloying bulk-immiscible iridium and palladium inhibits hydride formation and promotes catalytic performances.

The hydrogen sorption properties of oxide-supported Ir-Pd nanoalloys have been determined for the first time, and correlated with their catalytic behavior. The addition of Ir to Pd suppresses hydride formation and leads to improved catalytic performances with respect to pure metals in the preferential oxidation of CO in H2 excess (PROX).

A comparative insight of potassium vanadates as positive electrode materials for Li batteries: influence of the long-range and local structure.

Potassium vanadates with ratio K/V = 1:3, 1:4, and 1:8, prepared by a fast and facile synthesis route, were investigated as positive electrode materials in lithium batteries. KV3O8 and K0.5V2O5 have layered structures, while K0.

A four-component reaction involving in situ generated organometallic reagents: straightforward access to β-amino esters.

Four in one: A straightforward synthesis of β(2,3)-amino esters is described through a new zinc-mediated, cobalt-catalyzed four-component reaction between organic bromides, alkyl acrylates, amines, and aldehydes (see scheme). Synthesis involves a Mannich-related conjugate addition/aza-aldol domino sequence, allowing the formation of three single bonds in one step. A reaction mechanism, emphasizing the crucial role of zinc salts, is described.

An electrochemical nickel-catalyzed arylation of 3-amino-6-chloropyridazines.

3-Amino-6-aryl- and 3-amino-6-heteroarylpyridazines have been obtained in generally good yield using a nickel-catalyzed electrochemical cross-coupling between 3-amino-6-chloropyridazines and aryl or heteroaryl halides at room temperature. Comparative experiments involving classical palladium-catalyzed reactions, such as Suzuki, Stille, or Negishi cross-couplings, reveal that the electrochemical method can constitute a reliable alternative tool for biaryl formation. A possible reaction mechanism is proposed on the basis of electrochemical analyses.

Segmental motions of poly(ethylene glycol) chains adsorbed on Laponite platelets in clay-based hydrogels: a NMR investigation.

The segmental dynamics of poly(ethylene glycol) (PEG) chains adsorbed on the clay platelets within nanocomposite PEG/Laponite hydrogels was investigated over the tens of microseconds time scale, using combined solution and solid-state NMR approaches. In a first step, the time evolution of the molecular mobility displayed by the PEG chains following the addition to a Laponite aqueous dispersion was monitored during the aggregation of the clay disks and the hydrogel formation, by means of (1)H solution-state NMR. Part of the PEG repeat units were found to get strongly constrained during the gelation process.

Synthesis and cytotoxic evaluation of novel paraconic acid analogs.

A novel class of 2,3-tri- and tetrasubstituted γ-butyrolactones analogous to paraconic acids has been synthesized in one step using a straightforward three-component reaction among aryl bromides, dimethyl itaconate and carbonyl compounds. The in vitro cytotoxic activity of representative compounds has been evaluated against a panel of human cancer cell lines (KB, HCT116, MCF7, HL60). While most molecules exhibit a low to moderate background activity on both KB and HL60 cancer cell lines, one compound shows increased antiproliferative activities against both cell lines with IC(50) values in the 10(-7)-10(-6)mol/L range.

Thermal aging of interfacial polymer chains in ethylene-propylene-diene terpolymer/aluminum hydroxide composites: solid-state NMR study.

The possible influence of micrometric-size filler particles on the thermo-oxidative degradation behavior of the polymer chains at polymer/filler interfaces is still an open question. In this study, a cross-linked ethylene-propylene-diene (EPDM) terpolymer filled by aluminum trihydrate (ATH) particles is investigated using (1)H solid-state NMR. The time evolution of the EPDM network microstructure under thermal aging at 80 °C is monitored as a function of the exposure time and compared to that of an unfilled EPDM network displaying a similar initial structure.

A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates.

A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates is described. This route involves the formation of an imine, which is used without isolation, followed by its activation by the carbonyl-containing electrophile and the trapping of the acyliminium by an organozinc reagent. Most steps are conducted concomitantly to render the procedure as practical and straightforward as possible.