A molecular substitutional disorder case study suitable for instruction: L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L is 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide).

A solution of CrII and CrIII complexes, bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)(tetrahydrofuran)chromium(II)-bis(2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ido)[(trimethylsilyl)methyl]chromium(III) (0.88/0.12), [Cr(C30H38N3)2(C4H8O)]0.88[Cr(C30H38N3)2(C4H11Si)]0.12 or L2CrII(THF)/L2[(trimethylsilyl)methyl]CrIII (L = 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrol-1-ide and THF is tetrahydrofuran), in pentane crystallizes in the monoclinic space group P21/c. The structure obtained shows most of the atoms coincident but with THF disordered with the (trimethylsilyl)methyl ligand. Structures with this disorder, involving more than two or three atoms, seem to appear rarely in the literature; however, in this case, the data set is ideal for the crystallographic instruction of molecular substitution disorder.

Precious-Metal-Decorated Chromium(IV) Oxide Nanowires as Efficient Catalysts for 2,4-Toluenediamine Synthesis.

The catalytic hydrogenation of 2,4-dinitrotoluene (DNT) to 2,4-toluenediamine (TDA) is a key step in the production of polyurethanes; therefore, the development of efficient hydrogenation catalysts for industrial use is of paramount importance. In the present study, chromium(IV) oxide nanowires were decorated by palladium and platinum nanoparticles in a one-step, simple, and fast preparation method to yield highly efficient hydrogenation catalysts for immediate use. The nanoparticles were deposited onto the surface of CrO2 nanowires by using ultrasonic cavitation and ethanol as a reduction agent. Beneficially, the catalyst became catalytically active right at the end of the preparation and no further treatment was necessary. The activity of the Pd- and Pt-decorated CrO2 catalysts were compared in the hydrogenation of 2,4-dinitrotoluene (DNT). Both catalysts have shown high activity in the hydrogenation tests. The DNT conversion exceeded 98% in both cases, whereas the 2,4-toluenediamine (TDA) yields were 99.7 n/n% and 98.8 n/n%, with the Pd/CrO2 and Pt/CrO2, respectively, at 333 K and 20 bar H2 pressure. In the case of the Pt/CrO2 catalyst, 304.08 mol of TDA formed with 1 mol Pt after 1 h hydrogenation. Activation energies were also calculated to be approximately 24 kJ∙mol-1. Besides their immediate applicability, our catalysts were well dispersible in the reaction medium (methanolic solution of DNT). Moreover, because of their magnetic behavior, the catalysts were easy to handle and remove from the reaction media by using a magnetic field.

Design of Multi-Shelled Hollow Cr2 O3 Spheres for Metabolic Fingerprinting.

Schizophrenia (SZ) detection enables effective treatment to improve the clinical outcome, but objective and reliable SZ diagnostics are still limited. An ideal diagnosis of SZ suited for robust clinical screening must address detection throughput, low invasiveness, and diagnosis accuracy. Herein, we built a multi-shelled hollow Cr2 O3 spheres (MHCSs) assisted laser desorption/ionization mass spectrometry (LDI MS) platform for the direct metabolic profiling of biofluids towards SZ diagnostics. The MHCSs displayed strong light absorption for enhanced ionization and microscale surface roughness with stability for the effective LDI of metabolites. We profiled urine and serum metabolites (≈1 µL) with the enhanced LDI efficacy in seconds. We discriminated SZ patients (SZs) from healthy controls (HCs) with the highest area under the curve (AUC) value of 1.000 for the blind test. We identified four compounds with optimal diagnostic power as a simplified metabolite panel for SZ and demonstrated the metabolite quantification for clinic use. Our approach accelerates the growth of new platforms toward a precision diagnosis in the near future.

Green Synthesis of Chromium Oxide Nanoparticles for Antibacterial, Antioxidant Anticancer, and Biocompatibility Activities.

This study deals with the green synthesis of chromium oxide (Cr2O3) nanoparticles using a leaf extract of Abutilon indicum (L.) Sweet as a reducing and capping agent. Different characterization techniques were used to characterize the synthesized nanoparticles such as X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), Energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible (UV-VIS) spectroscopy. The X-ray diffraction technique confirmed the purity and crystallinity of the Cr2O3 nanoparticles. The average size of the nanoparticles ranged from 17 to 42 nm. The antibacterial activity of the green synthesized nanoparticles was evaluated against four different bacterial strains, E. coli, S. aureus, B. bronchiseptica, and B. subtilis using agar well diffusion and a live/dead staining assay. The anticancer activities were determined against Michigan Cancer Foundation-7 (MCF-7) cancer cells using MTT and a live/dead staining assay. Antioxidant activity was investigated in the linoleic acid system. Moreover, the cytobiocompatibility was analyzed against the Vero cell lines using MTT and a live/dead staining assay. The results demonstrated that the green synthesized Cr2O3 nanoparticles exhibited superior antibacterial activity in terms of zones of inhibition (ZOIs) against Gram-positive and Gram-negative bacteria compared to plant extracts and chemically synthesized Cr2O3 nanoparticles (commercial), but comparable to the standard drug (Leflox). The green synthesized Cr2O3 nanoparticles exhibited significant anticancer and antioxidant activities against MCF-7 cancerous cells and the linoleic acid system, respectively, compared to chemically synthesized Cr2O3 nanoparticles. Moreover, cytobiocompatibility analysis displayed that they presented excellent biocompatibility with Vero cell lines than that of chemically synthesized Cr2O3 nanoparticles. These results suggest that the green synthesized Cr2O3 nanoparticles' enhanced biological activities might be attributed to a synergetic effect. Hence, green synthesized Cr2O3 nanoparticles could prove to be promising candidates for future biomedical applications.

Pipette-tip SPE based on Graphene/ZnCr LDH for Pb(II) analysis in hair samples followed by GFAAS.

In this work, a nanocomposite of ZnCr layered double hydroxide (ZnCr LDH) and graphene oxide (GO) was successfully assembled. An efficient pipette-tip solid-phase extraction (PT-SPE) based on GO/ZnCr LDH followed by GFAAS analysis was used for to preconcentrate Pb(II) in hair samples. Hair samples were treated using acid digestion to make the solid samples suitable for performing the PT-SPE procedure and decrease the interactions between Pb(II) ions and the sample matrix. The sorbent was characterized by FT-IR, SEM, TEM, EDX, elemental mapping, and XRD. Effective extraction parameters were thoroughly investigated. Under the best conditions, the calibration plot was linear within the range of 0.5-15 ng mL-1 (R2 = 0.991). Preconcentration factor (PF) of 10 and absolute recovery (%) of 100% were obtained. LOD and LOQ were found to be 0.1 µg g-1 and 0.5 µg g-1, respectively. The intra-day and inter-day precisions (n = 3) at the concentrations of 2.0 and 10 ng mL-1 were less than 6.8% and 12.5%, respectively. Finally, the method efficiency was investigated for the analysis of Pb(II) in hair samples, and good relative recoveries (RR%) were obtained within the range of 92%-104%.

Anion-regulated binding selectivity of Cr(III) in collagen.

We present a mechanism for the selectivity of covalent/electrostatic binding of the Cr(III) ion to collagen, mediated by the kosmotropicity of the anions. Although a change in the long-range ordered structure of collagen is observed after covalent binding (Cr(III)-OOC) in the presence of SO4 2- at pH 4.5, the νsym (COO- ) band remains intense, suggesting a relatively lower propensity for the Cr(III) to bind covalently instead of electrostatically through Cr(H2 O)6 3+ . Replacing SO4 2- with Cl- reduces the kosmotropic effect which further favors the electrostatic binding of Cr(III) to collagen. Our findings allow a greater understanding of mechanism-specific metal binding in the collagen molecule. We also report for the first time, surface-enhanced Raman spectroscopy to analyze binding mechanisms in collagen, suggesting a novel way to study chemical modifications in collagen-based biomaterials.

In situ structural studies during denaturation of natural and synthetically crosslinked collagen using synchrotron SAXS.

Collagen is an important biomacromolecule, making up the majority of the extracellular matrix in animal tissues. Naturally occurring crosslinks in collagen stabilize its intermolecular structure in vivo, whereas chemical treatments for introducing synthetic crosslinks are often carried out ex vivo to improve the physical properties or heat stability of the collagen fibres for applications in biomaterials or leather production. Effective protection of intrinsic natural crosslinks as well as allowing them to contribute to collagen stability together with synthetic crosslinks can reduce the need for chemical treatments. However, the contribution of these natural crosslinks to the heat stability of collagen fibres, especially in the presence of synthetic crosslinks, is as yet unknown. Using synchrotron small-angle X-ray scattering, the in situ role of natural and synthetic crosslinks on the stabilization of the intermolecular structure of collagen in skins was studied. The results showed that, although natural crosslinks affected the denaturation temperature of collagen, they were largely weakened when crosslinked using chromium sulfate. The development of synergistic crosslinking chemistries could help retain the intrinsic chemical and physical properties of collagen-based biological materials.

A comparative study on the physicochemical characteristics of nanoparticles released in vivo from CoCrMo tapers and cement-stem interfaces of total hip replacements.

The good biocompatibility and corrosion resistance of the bulk CoCrMo alloy has resulted in it being used in the manufacture of implants and load bearing medical devices. These devices, however, can release wear and corrosion products which differ from the composition of the bulk CoCrMo alloy. The physicochemical characteristics of the particles and the associated in vivo reactivity are dictated by the wear mechanisms and electrochemical conditions at the sites of material loss. Debris released from CoCrMo hip bearings, taper junctions, or cement-stem interfaces can, therefore, have different chemical and morphological characteristics, which provide them with different in vivo toxicities. Here, we propose to assess and compare the characteristics of the particles released in vivo from CoCrMo tapers and cement-stem interfaces which have received less attention compared to debris originating from the hip bearings. The study uses state-of-art characterization techniques to provide a detailed understanding of the size, morphology, composition, and chemistry of the particles liberated from the wear and corrosion flakes from revised hip replacements, with an enzymatic treatment. The phase analyses identified Cr2 O3 nanoparticles released from tapers and cement-stem interfaces, whose composition did not vary with origin or particle morphology. The size distributions showed significantly smaller particles were released from the stems, compared to the particles originating from the corresponding tapers. The investigation demonstrates that the tribocorrosive processes occurring at the taper and stem interfaces both result in Cr2 O3 nanoparticle formation.

Facile green synthesis approach for the production of chromium oxide nanoparticles and their different in vitro biological activities.

Green synthesis of nanoparticles using plants has become a promising substitute for the conventional chemical synthesis methods. In the present study, our aim was to synthesize chromium oxide nanoparticles (Cr2 O3 NPs) through a facile, low-cost, eco-friendly route using leaf extract of Rhamnus virgata (RV). The formation of Cr2 O3 NPs was confirmed and characterized by spectroscopic profile of UV-Vis, EDX, FTIR, and XRD analyses. The UV-visible spectroscopy has confirmed the formation of Cr2 O3 NPs by the change of color owing to surface plasmon resonance. The bioactive functional groups present in the leaf extract of RV involved in reduction and stabilization of Cr2 O3 NPs were determined by FTIR analysis. Based on XRD analysis, crystalline nature of Cr2 O3 NPs was determined. The morphological shape and elemental composition of Cr2 O3 NPs were investigated using SEM and EDX analyses, respectively. With growing applications of Cr2 O3 NPs in biological perspectives, Cr2 O3 NPs were evaluated for diverse biopotentials. Cr2 O3 NPs were further investigated for its cytotoxicity potentials against HepG2 and HUH-7 cancer cell lines (IC50 : 39.66 and 45.87 µg/ml), respectively. Cytotoxicity potential of Cr2 O3 NPs was confirmed against promastigotes (IC50 : 33.24 µg/ml) and amastigotes (IC50 : 44.31 µg/ml) using Leishmania tropica (KMH23 ). The Cr2 O3 NPs were further evaluated for antioxidants, biostatic, alpha-amylase, and protein kinase inhibition properties. Biocompatibility assay was investigated against human macrophages which confirmed the nontoxic nature of Cr2 O3 NPs. Overall, the synthesized Cr2 O3 NPs are biocompatible and nontoxic and proved to possess significant biopotentials. In future, different in vivo studies are needed to fully investigate the cytotoxicity and mechanism of action associated with these Cr2 O3 NPs.

Cr2O3/cellulose hybrid nanocomposites with unique properties: Facile synthesis, photocatalytic, bactericidal and antioxidant application.

Development of high responsive photocatalysts for the degradation of dye from water is a significance method to solve the difficulties of water contamination. In the present project, Cr2O3 nanoparticles were decorated onto cellulose through a facile synthesis method, which was exposed to characterization by XRD, FESEM, DLS, PL, and UV-vis spectroscopy. The structural attributes confirmed the presence of rhombohedral phase of Cr2O3 nanoparticles. The mean crystal size of Cr2O3, and Cr2O3/cellulose nanocomposites were 38.50 nm, and 50.11 nm, respectively. The band gap values (Eg) of Cr2O3, and Cr2O3/cellulose nanocomposites were was found 3.00, and 2.53 eV, respectively. Moreover, the morphological and optical studies have been showed the impressive photocatalytic properties of the prepared Cr2O3/cellulose nanocomposites. The photocatalytic efficiency of Cr2O3, and Cr2O3/cellulose nanocomposites has been investigated for the photo-degradation of crystal violet in the ultraviolet light region. The Cr2O3/cellulose indicated promising photocatalytic performance and up to 99.65% of the crystal violet was photo-degraded in 40 min. The obtained crystal violet degradation results were fitted onto a Langmuir-Hinshelwood (L-H) plot. The antioxidant performances of Cr2O3, and Cr2O3/cellulose were analyzed. The beneficial antibacterial performance of the Cr2O3/cellulose nanocomposites was tested by various bacteria as Escherichia coli, Pseudomonas aeruginosa, staphylococcus aurous, and Streptococcus pyogenes.

Preliminary studies of the effect of doping of chromium oxide in SiO2-CaO-P2O5 bioceramics for bone regeneration applications.

Bioceramics of composition xCr2O3∙(43-x) CaO∙42SiO2∙15P2O5 (x varying from 0 to 8 mol%) have been synthesized in the laboratory by using sol-gel technique. The morphology and structure has been determined by using Powder X-ray Diffraction, Fourier Transform Infrared and Raman spectroscopy and Field Emission Scanning Electron Microscopy. The in vitro bio mineralization behavior has been assessed by immersion in simulated body fluid for 7 days. The results obtained in our studies have indicated excellent hydroxyapatite formation ability of our samples. Drug delivery property of synthesized samples has been checked by using UV-spectroscopy of antibiotic 'gentamicin'. The in vitro drug release profile was fitted best in the Higuchi model with the highest value of coefficient of determination (R2 = 0.9970). Antimicrobial properties have been evaluated from minimum inhibitory concentration and time kill assay values. The cellular response has been investigated by using human osteosarcoma MG 63 cell line. Also to check charge on the synthesized samples, Zeta potential studies have been conducted and it has been observed that samples carry negative charge when immersed in simulated body fluid. Negative surface charge provide suitable environment for cell adhesion and proliferation. Experiments have been undertaken to explore suitable composition with an objective of development of suitable implant material for bone regeneration applications.

Cr2S3-Co3O4 on polyethylene glycol-chitosan nanocomposites with enhanced ultraviolet light photocatalysis activity, antibacterial and antioxidant studies.

A novel chromium sulfide-cobalt oxide nanostructures and decorated on Polyethylene Glycol (PEG)-chitosan (CS) nanocomposites as catalyst was synthesized by a facile method, and characterized by XRD, SEM, UV-Vis and XPS spectrum. The as-prepared Cr2S3-Co3O4/PEGCS composites represented the photo-decompose efficiency against the decomposition of basic dye (Rhodamine B (RhB)). The band gap of nano-catalyst was determined to be in the range of 2.61 to 3.32 eV. The introduction of Cr2S3 into Co3O4 increased the photocatalytic performance slightly, and decoration of Cr2S3-Co3O4 on PEGCS, which indicated the highest photo-degradation performance. Under the light irradiation, the active species OH and O2- radicals were important active agents in the photocatalysis process. The Cr2S3-Co3O4/PEGCS nanocomposites can maintain a stable photocatalysis performance after five cycles. Finally, the reaction mechanism of photo-degradation of RhB was put forward. The antibacterial test demonstrated the remarkable properties of Cr2S3-Co3O4/PEGCS nanocomposites in this research.

Interaction of polypyridyl Cr(III) complexes with bovine serum albumin.

We report a detailed investigation of the interaction of Cr(NN)33+ with bovine serum albumin (BSA), an important protein for the transport of drugs in blood plasma which allows us to understand further the role of Cr(NN)33+ as a sensitizer in photodynamic therapy (PDT). Chromium(III) complexes, Cr(5Cl-phen)33+, Cr(5Me-phen)33+ and Cr(5Ph-phen)33+ (where Cl = chlorine, Me = methyl and Ph = phenyl are substituents in position 5 of the phen = 1,10-phenanthroline bidentate ligand), were used for the present study. The interactions of BSA with Cr(NN)33+ were assessed employing fluorescence spectroscopy and UV-Vis absorption spectroscopy; in addition electrochemical experiments carried out at a liquid/liquid interface gave insight into the relative hydrophobicities of the complexes. We found that chromium complexes bind strongly with bovine serum albumins (BSA) with intrinsic binding constants, Kb, of (3.33 ± 0.08) × 105 M-1, (5.92 ± 0.08) × 105 M-1 and (1.64 ± 0.05) × 105 M-1 at 300.3 K. Analysis of the thermodynamic parameters ΔG, ΔH, and ΔS indicated that hydrophobic interactions played a major role in all the BSA-Cr(NN)33+ association processes. The binding distances and transfer efficiencies for BSA binding reactions were calculated according to the Förster theory of non-radiation energy transfer giving distance (r) of 2.63 nm, 2.94 nm and 3.00 nm for 5Clphen, 5Mephen and 5Ph phenanthroline complexes, respectively. All these experimental results indicate that Cr(NN)33+ binds to serum albumins, by which these proteins could act as carriers of this complex for further applications in PDT.

Coagulation mechanism of cellulose/metal nanohybrids through a simple one-step process and their interaction with Cr (VI).

In this work, the coagulation mechanism of the cellulose/metal nanohybrids and the binding mode with Cr (VI) are deeply described. Nanohybrids with 3D porous networks were prepared from cellulose/Fe2O3-SO3H solutions through a simple one-step coagulation process in NaCl aqueous solutions. The structure and properties of nanohybrids were characterized by SEM, EDS, XRD, FTIR, and XPS. The cellulose/metal nanohybrids have a langmuir maximum adsorption capacity of 11.46 mg/g. The dissolved metal nanoparticles could form strong hydrogen bonding with cellulose by breaking the intermolecular hydrogen bonds between the polymer molecules. The porous networks of cellulose/metal nanohybrids provided multiple adsorption sites for Cr2O72- anion through FeO…Cr interactions. The cooperation between cellulose and Fe2O3-SO3H nanoparticles makes the hybrids exhibiting a satisfactory selectivity and affinity for Cr (VI). The cellulose/metal nanohybrids selectively interacted with Cr2O72- via Fe atom from Fe2O3 and oxygen atom from SO3- groups. The Cr (VI) adsorption occurred via a two-step process, the first of them was the initial adsorption of Cr2O72- on cellulose/metal nanohybrids surface, followed by the rearrangement of Cr2O72- molecules and the consecutive growth of Cr2O72- aggregate layers.

Analysis of Density Changes of Selected Brain Receptors After a 14-Day Supply of Chromium(III) and Evaluation of Chromium(III) Affinity to Selected Receptors and Transporters.

Chromium(III) is one of the most controversial biometals. Although, it is no longer on the list of minerals necessary for the proper functioning of the human body, and its pharmacological effect is still under discussion. One of the purposes of Cr(III) administration is to use it in patients with mood disorders and it is strictly related to its pharmacological, not dietary effect. This is because its high doses are necessary to obtain the results and additionally, no deficiencies in human population have been noted. In this study, the affinity of chromium(III) to selected receptors and transporters in the rat brain was evaluated, and the effect of the 14-day administration of this metal was assessed on the density of selected receptors. All analyses were performed in vitro using radioligand binding assays, and the results indicated lack of affinity to ß1 and α1 receptors and serotonin transporter (SERT), furthermore very weak affinity to the 5-HT1A receptor (30% inhibition at 10-4 and 10-5 M). Analysis of the α1 and ß1 adrenergic receptor density indicated lack of any adaptive effects after 14 days of Cr(III) administration through intraperitoneal injections (doses 6 and 12 mg/kg). The antidepressant activity of chromium(III) indicated in clinical trials concerned patients with atypical, seasonal, or dystonic symptoms. This effect, as it seems based on the presented results, does not depend on direct affinity to serotonin receptors and transporter nor is the result of adaptive changes in the adrenoreceptor system.

Oxygen-Tolerant Hydrogen Peroxide Reduction Catalysts for Reliable Noninvasive Bioassays.

Noninvasive bioassays based on the principle of a hydrogen peroxide (H2 O2 ) cathodic reaction are highly desirable for low concentration analyte detection within biofluids since the reaction is immune to interference from oxidizable species. However, the inability to selectively reduce H2 O2 over O2 for commonly used stable catalysts (carbon or noble metals) is one of the key factors limiting their development and practical applications. Herein, catalysts that enable selective H2 O2 reduction in the presence of oxygen with fluctuating concentrations are reported. These catalysts consist of noble metal nanoparticles underneath an amorphous chromium oxide nanolayer, which inhibits O2 diffusion to the metal/oxide interface and suppresses its reduction reaction. Using these catalysts, analytes of low concentration in biofluids, including but not limited to glucose and lactate, are detected within the presence of various interferents. This work enables wide application of the cathodic detection principle and the development of reliable noninvasive bioassays.

Preparation, and structural of new NiS-SiO2 and Cr2S3-TiO2 nano-catalyst: Photocatalytic and antimicrobial studies.

NiS-SiO2 and Cr2S3-TiO2 synthesized by Ultrasound-Microwave method was tested for the photo-degradation of methyl red as azo dye under ultraviolet (UV) light. The structure and morphology of the synthesized materials were examined through scanning electron microscopy, X-ray diffraction and photoelectron spectroscopy, energy-dispersive spectroscopy, dynamic light scattering and the band gap energy differences were determined through diffuse reflectance spectroscopy (DRS). The crystallite size and band gap values of SiO2, TiO2, NiS-SiO2 and Cr2S3-TiO2-1 were obtained from XRD and UV-vis DRS analysis and found insignificant 44.22, 54.11, and 57.11 nm, and 8.9, 3.2, 3.0, 2.7 eV, respectively. The NiS-SiO2 and Cr2S3-TiO2 nanocomposites exhibited good stability and catalytic performance in the azo dye degradation; the composite provides a complete degradation after 50 min under UV irradiation. The effects of different quencher compounds on the Methyl red dye degradation were also investigated. The result for this experiment shows the system without the quencher was highly degradation of Methyl red. The antibacterial influence of the SiO2, TiO2, NiS-SiO2 and Cr2S3-TiO2-1 were studied versus two species bacteria. The antifungal performance of this nanoparticle was analyzed versus two species fungi as the C. albicans and P. funiculosum. Biological data demonstrated that the prepared catalyst has great bactericidal and fungicidal properties.

Hypoglycemic activity and mechanism of the sulfated rhamnose polysaccharides chromium(III) complex in type 2 diabetic mice.

The sulfated rhamnose polysaccharides found in Enteromorpha prolifera belong to a class of unique polyanionic polysaccharides with high chelation capacity. In this study, a complex of sulfated rhamnose polysaccharides with chromium(III) (SRPC) was synthesized, and its effect on type 2 diabetes mellitus (T2DM) in mice fed a high-fat, high-sucrose diet was investigated. The molecular weight of SRPC is 4.57 kDa, and its chromium content is 28 µg/mg. Results indicated that mice treated by oral administration of SRPC (10 mg/kg and 30 mg/kg body mass per day) for 11 weeks showed significantly improved oral glucose tolerance, decreased body mass gain, reduced serum insulin levels, and increased tissue glycogen content relative to T2DM mice (p < 0.01). SRPC treatment improved glucose metabolism via activation of the IR/IRS-2/PI3K/PKB/GSK-3ß signaling pathway (which is related to glycogen synthesis) and enhanced glucose transport through insulin signaling cascade-induced GLUT4 translocation. Because of its effectiveness and stability, SRPC could be used as a therapeutic agent for blood glucose control and a promising nutraceutical for T2DM treatment.

Chromium(VI) formation via heating of Cr(III)-Fe(III)-(oxy)hydroxides: A pathway for fire-induced soil pollution.

Mixed Cr(III)-Fe(III) (oxy)hydroxides are important Cr-bearing phases in natural, unpolluted soil. Fires frequently affect large areas of land around the world, causing the temporary development of elevated soil temperatures. This study examines the hypothesis that heating Cr(III)-Fe(III) (oxy)hydroxides at temperatures which occur in surface soils during fires can drive rapid oxidation of Cr(III) to hazardous Cr(VI). To test this, poorly-ordered Cr(III)x-Fe(III)1-x (oxy)hydroxides, with x spanning 0.1 to 0.9, were heated at up to 800 °C for 2 h. Heating at 400-800 °C produced a highly crystalline hematite-eskolaite solid-solution (FeIII2-nCrIIInO3, where n ranges from 0 to 2). Chromium K-edge X-ray absorption spectroscopy showed that during heating up to ∼40% of the initial Cr(III) was oxidized to Cr(VI), with the greatest extent of Cr(VI) formation occurring at 200-400 °C. At these temperatures, a substantial proportion (17%-70%) of the newly-formed Cr(VI) was exchangeable (i.e. extracted by a pH 7.2, 10 mM PO43- solution). This suggests that much of the Cr(VI) formed by heating of Cr(III)x-Fe(III)1-x (oxy)hydroxides at 200-400 °C is likely to be relatively mobile in fire-impacted soils. The results of this study provide new insights into a potentially-important pathway for the in-situ formation of Cr(VI) in soil.