Lithographic feature size requirements have approached a few radius of gyration of photoresist polymers used in thin-film patterning. Furthermore, the feature dimensions are commensurate with the photoacid diffusion length that defines the underlying latent image. Smaller imaging building blocks may enable reduced feature sizes; however, resolution limits are also dependent ...

Knowledge of location and intracellular subcompartmentalization is essential for the understanding of redox processes, because oxidants, owing to their reactive nature, must be generated close to the molecules modified in both signaling and damaging processes. Here we discuss known redox characteristics of various mitochondrial microenvironments. Points covered are the locations ...

In oxides, the substitution of non-oxide anions (F(-),S(2-),N(3-) and so on) for oxide introduces many properties, but the least commonly encountered substitution is where the hydride anion (H(-)) replaces oxygen to form an oxyhydride. Only a handful of oxyhydrides have been reported, mainly with electropositive main group elements or as ...

ABSTRACT: Hydrocephalus is associated with reduced blood flow in periventricular white matter. To investigate hypoxic and oxidative damage in the brains of rats with hydrocephalus, kaolin was injected into the cisterna magna of newborn 7- and 21-day-old Sprague-Dawley rats, and ventricle size was assessed by magnetic resonance imaging at 7, ...

Striking gold: Rather simple aryl substituents are required to convert acyclic diaminocarbenes (ADC) into useful pseudo-bidentate ligands for monomeric gold(I), which can enantioselectively catalyze a tandem acetylization/cycloisomerization reaction. Tf=trifluoromethanesulfonyl.

In the present work, in situ reduction of graphene oxide (GO) into graphene was preformed, after diffusion in exponentially growing polyelectrolyte multilayers, using sodium citrate as the reducing agent. First, the graphene oxide was obtained by treating a commercial grade of Expanded Graphite (EG). Based on XRD and Raman spectroscopy ...

In the present article a facile synthesis of cerium oxide nanoparticles (CNPs) encapsulated in PLGA microparticles is reported. The release kinetics of the CNPs from the PLGA matrix was investigated under acidic, basic and near-neutral pH. A diffusion model was applied to determine the diffusivity of the CNPs from the ...

Urea, the white gold: The efficient synthesis of tertiary and secondary amines is achieved by heterogeneous gold-catalyzed direct amination of stoichiometric alcohols with urea in good to excellent yields. Via a hydrogen autotransfer pathway, the reactions of primary alcohols with urea give tertiary amines exclusively, while secondary alcohols selectively afford ...

Three novel coumarin compounds along with two known amide alkaloids were isolated from a methanol extract of the red ants of ChangBai Mountain, Tetramorium sp. Their structures were identified on the basis of IR, 2D NMR ((1)H-(1)H COSY, HSQC, HMBC and NOESY) and HRESIMS analysis. Antibacterial activity of all the ...

Solution combustion using urea as a fuel was employed to synthesise Co oxide and Al(2)O(3)-, SiO(2)- and TiO(2)-supported Co oxide catalysts. The catalysts were characterised using several techniques such as N(2) adsorption/desorption, XRD, FTIR, UV-vis diffuse reflectance and SEM-EDX, and their catalytic activity was evaluated in phenol degradation in aqueous ...

Catalytic wet air oxidation (CWAO) using membrane contactors is attractive for remediation of aqueous pollutants, but previous studies of even simple reactions such as formic acid oxidation required multiple passes through tubular ceramic membrane contactors to achieve high conversion. This work aims to increase single-pass CWAO conversions by using polysulfone ...

The nitric acid oxidation of d-glucose was reinvestigated in an effort to better understand and improve the oxidation and subsequent work up steps. The oxidation was carried out using a computer controlled reactor employing a closed reaction flask under an atmosphere of oxygen which allowed for a catalytic oxidation process ...

The chemical composition of the hydrodistilled leaf essential oil from Pulicaria stephanocarpa Balf. Fil was determined by GC-MS analysis, and its antimicrobial, antioxidant and anticholinesterase (AChE) activities were evaluated. Eighty-three compounds were identified representing 97.2% of the total oil. (E)-Caryophyllene 13.4%, (E)-nerolidol 8.5%, caryophyllene oxide 8.5%, alpha-cadinol 8.2% spathulenol 6.8% ...

Piceatannol is present in passion fruit (<i>Passiflora edulis</i>) seeds in high amounts. In this study, we isolated the second major polyphenolic compound of passion fruit seeds and identified it as scirpusin B, which is a dimer of piceatannol. We investigated the antioxidant activities and vasorelaxing effects of these polyphenols. Their ...

The present study was undertaken to assess the role of reactive oxygen species (ROS) in rat aortic ring vasoreactivity and integrity by using various peroxovanadate (pV) compounds. All the pV compounds (1nM-300μM) used in the present study exerted concentration-dependent contractions on endothelium intact rat aortic rings. All compounds with an ...

This study was aimed to assess the desirable and undesirable effects of iron (100 mg/day as ferrous sulphate) and folic acid (500 μg/day) supplementation in iron deficient anemic women. Iron and folic acid supplementations were given to 117 anemic women (mild = 55, moderate = 40, and severe = 22) and 60 age matched placebo treated (100 mg cane ...

A facile synthetic approach towards 6-alkyl-2-amino-4-aryl-4a,5,6,7,8,8a-hexahydro-8a-methoxy-4H-pyrano[3,2-c]pyridine-3-carbonitriles 3a-n was reported via reaction of 1-alkyl-4-piperidones 1a,b with ylidenemalononitriles 2a-h in methanol in the presence of sufficient amount of sodium. The structure of 3 was established through different spectroscopic techniques and confirmed by single crystal X-ray studies. Vasodilation activities of the synthesized compounds ...

Flexible protected 1,3,4-trihydroxy-2-butanone is synthesized in high enantiomeric excesses by using asymmetric homo- and cross- acyloin coupling of aliphatic aldehydes catalyzed by benzaldehyde lyase.

Three series of new 2-[(4-substituted piperazin-1-yl) methyl]quinazolin-4(3H)-ones 4a-c, Ethyl 6,7-dimethoxy-4-oxo-3-[2-(4-substituted piperazin-1-yl)acetamido/propanamido]-3,4-dihydroquinazoline-2-carboxylates 9a-f and their 2-methyl analogues 13a-l were designed and synthesized as promising α(1)-adrenoceptor antagonists. The final compounds were evaluated for their in vivo hypotensive activity in normotensive cats. The most potent hypotensive quinazolinone derivatives 4b, 9e, 13i, 13j were ...

Ionizing radiation causes DNA damage and consequent apoptosis, mainly due to the production of hydroxyl radicals (HO•) that follows radiolytic splitting of water. However, superoxide (O2•-) and H2O2 also form and induce oxidative stress with resulting LMP (lysosomal membrane permeabilization) arising from iron-catalysed oxidative events. The latter will contribute significantly ...

As a part of the nitroso signalling pathway, nitroso-compounds serve as stores and carriers of NO; as part of the sulphide signalling pathway, bound sulfane-sulphur compounds serve as stores and carriers of H2S. Here we hypothesise a coupled sulphide-nitroso signalling pathway, in which H2S plays a main role. H2S releases ...

Arsenite (As(III)) is the predominant arsenic (As) species in reducing environments. As(III) is less strongly adsorbed than As(V) at circumneutral pH conditions by common non-iron metal oxides in sediments such as those of aluminum. Therefore, oxidation of As(III) to As(V) could contribute to an improved immobilization of As and thus ...

Radical halo-nitration of alkenes using iron(III) nitrate nonahydrate and halogen salt has been developed. The present reaction proceeds by radical addition of nitrogen dioxide generated by thermal decomposition of iron(III) nitrate nonahydrate and subsequent trapping of the resultant radical by a halogen atom in the presence of halogen salt. Application ...

Tridentate chelate ligands of 2,6-bis[hydroxy(methyl)amino]-1,3,5-triazine family rapidly release iron from human recombinant ferritin in the presence of oxygen. The reaction is inhibited by superoxide dismutase, catalase, mannitol and urea. Suggested reaction mechanism involves reduction of the ferritin iron core by superoxide anion, diffusion of iron(II) cations outside the ferritin shell, ...

In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl(3) under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized ...

Dexrazoxane (ICRF-187) has been clinically used to reduce doxorubicin-induced cardiotoxicity for more than 20 years. It has been proposed that dexrazoxane may act through its rings-opened hydrolysis product ADR-925, which can either remove iron from the iron-doxorubicin complex or bind to free iron, thus preventing iron-based oxygen radical formation. However, ...

Phosphorus is a biolimiting nutrient that has an important role in regulating the burial of organic matter and the redox state of the ocean-atmosphere system. The ratio of phosphorus to iron in iron-oxide-rich sedimentary rocks can be used to track dissolved phosphate concentrations if the dissolved silica concentration of sea ...

The use N-sulfonyl-protected hydroxylamines as bi-nucleophiles in iron-catalyzed propargylic substitutions allows the selective one-pot synthesis of four classes of substituted isoxazoles or isoxazolines from the same propargylic alcohols (21 examples) by simply tuning the nature of the base. By using an iron(III) catalyst and a base such as triethylamine (3 ...

An efficient method for an iron catalyzed oxidative indolation and methoxyphenylation of N-protected tetrahydroisoquinolines and isochroman is described including subsequent facile deprotection.

An efficient alkene aza-Cope-Mannich cyclization between 2-hydroxy homoallyl tosylamine and aldehydes in the presence of iron(III) salts to obtain 3-alkyl-1-tosyl pyrrolidines in good yields is described. The process is based on the consecutive generation of a γ-unsaturated iminium ion, 2-azonia-[3,3]-sigmatropic rearrangement, and further intramolecular Mannich reaction. Iron(III) salts are also ...

The iron complex [Fe(II)(TPA)(CH(3)CN)(2)](OTf)(2) (1) [TPA = tris(2-pyridylmethyl)amine] with H(2)O(2) as an oxidant performs ipso-hydroxylation of electron-withdrawing benzoic acids at room temperature, leading to multiple turnovers of corresponding phenols. ipso-Hydroxylation competes with olefin epoxidation and cis-dihydroxylation in the presence of olefins, with the product ratios being modulated by the relative ...

Iron oxide magnetic nanoparticles (MNPs) alone are suitable for a broad spectrum of applications, but the low stability and heterogeneous size distribution in aqueous medium represent major setbacks. These setbacks can however be reduced or diminished through the coating of MNPs with various polymers, especially biopolymers such as polysaccharides. Polysaccharides ...

A growing number of non-heme-iron oxygenases and oxidases catalyze reactions for which the well-established mechanistic paradigm involving a single C-H-bond-cleaving intermediate of the Fe(IV)-oxo (ferryl) type [1(•)] is insufficient to explain the chemistry. It is becoming clear that, in several of these cases, Fe(III)-superoxide complexes formed by simple addition of ...

Iron(III) chloride hexahydrate promotes a cascade of transformations on a Petasis condensation product that sets up the right dihydropyran precursors of valuable Relenza congeners.

Iron sulfide (as mackinawite, FeS) has shown considerable promise as a material for the removal of As(III) under anoxic conditions. However, as a nanoparticulate material, synthetic FeS is not suitable for use in conventional permeable reactive barriers (PRBs). This study developed a methodology for coating a natural silica sand to ...

Investigated the self-assembly and characterization of novel antifouling polyethylene glycol (PEG)-coated iron oxide nanoparticles as nanoprobes for magnetic resonance imaging (MRI) contrast agent. Monodisperse oleic acid-coated superparamagnetic iron oxide cores are synthesized by thermal decomposition of iron oleate. The self-assembly behavior between iron oxide cores and PEG-lipid conjugates in water ...

Methaemoglobin is the form of haemoglobin in which the iron moiety of the haem group has been oxidized from the ferrous to the ferric state. Methaemoglobinaemia is due to either an increase in the production of the oxidized haem moiety or due to decreased conversion back to the reduced form. ...

Autotrophic acidophilic iron- and sulfur-oxidizing bacteria of the genus Acidithiobacillus constitute a heterogeneous taxon encompassing a high degree of diversity at the phylogenetic and genetic levels, though currently only two species are recognized (Acidithiobacillus ferrooxidans and Acidithiobacillus ferrivorans). One of the major functional disparities concerns the biochemical mechanisms of iron ...

Polyphenol prevention of iron-mediated DNA damage occurs primarily through iron binding. Once bound, iron in the Fe(2+)-polyphenol complex autooxidizes to Fe(3+) in the presence of O(2). To determine the correlation between the rate of Fe(2+)-polyphenol autooxidation and polyphenol antioxidant ability, kinetic studies at pH = 6.0 in the presence of ...

Iron species have been suggested to be highly involved in the pathogenesis of Parkinson disease. However, the detailed mechanism of iron-induced dopaminergic degeneration is still unclear. In this study, we demonstrate that free iron ions (trivalent or bivalent) and iron ions in stable complex with cyanide ions (K(4)Fe(CN)(6) and K(3)Fe(CN)(6)) ...

A new method is described for facile synthesis of metal-chelating magnetic nanoparticles by simply mixing iron oxide nanoparticles with a bifunctional organophosphorus compound, N-(phosphonomethyl)iminodiacetic acid (PM-IDA), in aqueous solution. On charging with nickel ions, the PM-IDA functionalized iron oxide nanoparticles exhibited high His-tag protein binding capacity (0.21 and 0.58 mg/mg ...

Three samples of manganese associated hydrous iron(III) oxide (MNHFO), prepared by incinerating metal hydroxide precipitate at T (± 5)=90, 300 and 600°C, showed increase of crystalline nature in XRD patterns with decreasing As(III) removal percentages. TEM images showed the increase of crystallinity from sample-1 (MNHFO-1) to sample-3 (MNHFO-3). Dimensions (nm) ...

Oxidative stress resulting from photosensitized ROS production in skin is widely accepted as the main contributor to the deleterious effects of UVA exposure. Among the mechanisms known to be involved in UVA-induced oxidative damage, iron plays a central role. UVA radiation of skin cells induces an immediate release of iron, ...

Controversy exists about the safety of the parenteral iron dextran products, Dexferrum and INFeD, which have been associated with rare, serious anaphylactic-type reactions. In the United States, their product labels carry boxed warnings of this adverse event; some have called for the withdrawal from marketing of the higher molecular weight ...

The oxidation of organic compounds in oxygen saturated aqueous suspensions of nanoparticulate zero valent iron (nZVI) is rapidly becoming an area of important consideration for environmental scientists and engineers. Through the production of reactive oxygen species, oxidative processes do occur but have been shown to be of limited efficiency. To ...

The combined processes of biological As(III) oxidation and removal of As(III) and As(V) by zero-valent iron were investigated with synthetic water containing high As(III) concentration (10 mg L(-1)). Two up-flow fixed-bed reactors (R1 and R2) were filled with 2 L of sieved sand (d = 3 ± 1 mm) while ...

Multi-tiered arsenic distributions within nanoscale zero-valent iron (nZVI) were observed upon reactions of nZVI with aqueous As(iii) species, suggesting arsenite oxidation and reduction may occur in parallel at different sub-domains of the nanoparticles owing to the particle's core-shell structure. New insights into arsenic remediation with iron nanomaterials are obtained.

The nonheme di-iron oxygenase, AurF, converts p-aminobenzoate (Ar-NH(2), where Ar = 4-carboxyphenyl) to p-nitrobenzoate (Ar-NO(2)) in the biosynthesis of the antibiotic, aureothin, by Streptomyces thioluteus. It has been reported that this net six-electron oxidation proceeds in three consecutive, two-electron steps, through p-hydroxylaminobenzoate (Ar-NHOH) and p-nitrosobenzoate (Ar-NO) intermediates, with each step ...

We report a fundamental change in the understanding of iron oxide thermochemistry, opening a facile, new CO(2)-free route to iron production. The resultant process can eliminate a major global source of greenhouse gas emission, producing the staple iron in molten media at high rate and low electrolysis energy.

An electrochemical reactor was built and used to remove arsenite from water. In this reactor, arsenite can be oxidized into arsenate, which was removed by electro-coagulation process simultaneously. The reactor mainly included dimension stable anode (DSA) and iron plate electrode. Oxidation of arsenite will occur at the DSA electrode in ...