Abstract  The in situ monitoring of phosphate has been of great importance in many environmental applications, particularly those involving biological treatment processes and eutrophication monitoring. A microelectrode with small tip size (~10 mum) was fabricated with cobalt wire, characterized and evaluated for in situ and in vivo environmental analysis of phosphate in biological applications. The electrochemical performance of this cobalt-based microelectrode was fully examined for its characteristics, including detection limit, response time, selectivity, reproducibility, life time, interference with pH, ions and dissolved oxygen (DO), and the stirring effect. The microelectrode showed excellent selectivity for the orthophosphate ions (HPO(4) (2-), H(2)PO(4) (-)) in various environmental conditions. Alkalinity and DO were found to interfere with electrode response to phosphate. The phosphate microelectrode was also evaluated with Scanning Electron Microscopy (SEM) and Cyclic Voltammetry (CV). The developed microelectrode was used for in situ monitoring of phosphate in microbial flocs. Well-defined phosphate profiles across the flocs were observed under anaerobic (phosphorus release) conditions. This full characterization and successful application showed that the cobalt-based phosphate microelectrodes can be a very useful tool for in situ measurement of phosphate in various environmental conditions, including within microbial flocs.

Abstract  The reaction mechanism for the hydrolysis of trimethyl phosphate and of the obtained phosphodiester by the di-Co(II) derivative of organophosphate degrading enzyme from Agrobacterium radiobacter P230(OpdA), have been investigated at density functional level of theory in the framework of the cluster model approach. Both mechanisms proceed by a multistep sequence and each catalytic cycle begins with the nucleophilic attack by a metal-bound hydroxide on the phosphorus atom of the substrate, leading to the cleavage of the phosphate-ester bond. Four exchange-correlation functionals were used to derive the potential energy profiles in protein environments. Although the enzyme is confirmed to work better as triesterase, as revealed by the barrier heights in the rate-limiting steps of the catalytic processes, its promiscuous ability to hydrolyze also the product of the reaction has been confirmed. The important role played by water molecules and some residues in the outer coordination sphere has been elucidated, while the binuclear Co(II) center accomplishes both structural and catalytic functions. To correctly describe the electronic configuration of the d shell of the metal ions, high- and low-spin arrangement jointly with the occurrence of antiferromagnetic coupling, have been herein considered.

Abstract  Stabilized bovine pericardium (BP) belongs to tissues routinely applied in production of heart valves. Commercial products are manufactured from tissues crosslinked by glutaraldehyde (GA). Dye-mediated photooxidation was also proposed as an alternative method, which allows for the elimination of clinical failures of GA-treated tissues. The aim of the study was to investigate the density of BP stabilized by GA and the methylene blue-mediated photooxidation, as compared with a native tissue. Cross linking density was evaluated based on their ability to accumulate radioactive cobalt ions (Co-60(2+)) and the permeability to these ions. Radioactivity was examined using a gamma-spectrophotometer (Packard). The results showed the changes in the crosslinking density between the native tissues and photooxidized or GA-crosslinked tissues. Significant decreases in radioactivity were detected only in the thinnest tissues after photoxidation and in filtrates penetrating the same samples. Photooxidized pericardium of a larger thickness did not reveal any significant changes. Weight-dependence for the permeability was observed in the case of filtrates penetrating the GA-treated tissues. However, Co-60(2+)-accumulation in these samples remained at the same level. Photooxidation may lead to obtaining biomaterials with advantageous properties, i.e. a decreased calcium-binding capacity. Photooxidation efficiencies were dependent both on compactness and thickness of tissues and on process duration. It should be emphasized that the tissues' structure after photooxidation was characterized by lower density. This may point to the presence of crosslinks of a smaller compactness in comparison with GA treatment. It has been shown that the factor indeed influencing the result of crosslinking is tissue thickness.

Abstract  Skutterudite compounds form a new class of potential candidates for thermoelectric applications. Cobalt triantimonide (CoSb3) shows good thermoelectric properties at medium and high temperatures. Doping this system with substitution elements, for either Co or Sb or both, may result in an increase of the thermoelectric figure of merit (ZT). This work focused on the electrochemical doping and characterization of films and nanowires of Co-Sb system in citrate solutions using gold-coated PCTE templates. The electrodeposition was performed on gold surface that was pre-treated electrochemically to ensure reproducible results. The electrochemical treatment acted as an annealing process for the surface, which resulted in an increase in Au(111) as demonstrated by XRD. Detailed electrochemical studies including deposition-stripping experiments was performed in order to develop a better understanding of the co-deposition kinetics and a better control over the composition of doped Co-Sb system. Scanning electron microscopy (SEM/EDS) helped study the morphology and the composition of the doped and undoped Co-Sb system. Co-deposition of Co-Sb showed that the amount of Co is higher in nanowires than in film or mushroom caps due to the slow Sb deposition rate dictated by slow Sb(III) complex diffusion. Doped nanowires have been also obtained. Both Ni and Te electrochemical doping of the Co-Sb system affected the composition of the deposit but there was no effect on nanowire morphology.

Abstract  In this work, zeolitic imidazolate framework (ZIF) nanocrystal arrays were supported by graphene oxide (GO) nanosheets by a graphene assembly route. Then, ZIF-67/GO was transformed into nanoporous Co3O4/rGO composites through calcination. Both ZIF-67/GO and Co3O4/rGO were employed as active materials to modify glass carbon electrodes for hydrogen peroxide (H2O2) non-enzymatic sensor. The measurement results indicate that ZIF-67/GO presented excellent electro-catalytic activity towards H2O2 with a linear range of 0.1-22.9 mM and a low detection limit of 1.92 mM. More important, the Co3O4/rGO modified GC electrode showed higher detection sensitivity for H2O2 and the limit of detection can be as low as 7.87 nM. Furthermore, ZIF-67/GO and Co3O4/rGO modified electrodes both exhibited excellent selectivity in phosphate buffer solution and NaOH.

Abstract  It is highly attractive to develop non-noble-metal nanoarray architecture as a high-active catalyst electrode for molecular detection due to its large specific surface area and easy accessibility to target molecules. In this paper, we demonstrate the development of cobalt nitride nanowire array on Ti mesh(Co3N NW/TM) as an efficient catalyst electrode for glucose oxidation in alkaline solutions and H2O2 reduction in neutral solutions. Electrochemical tests suggest that such Co3N NW/TM possesses superior non-enzymatic sensing ability toward rapid glucose and H2O2 detection. As a glucose sensor, this fabricated electrode offers a high sensitivity of 3325.6 mu A mM(-1)cm(- 2), with a wide linear range from 0.1 mu M to 2.5 mM, a low detection limit of 50 nM (S/N = 3), and satisfactory stability and reproducibility. Its application in determining glucose in human blood serum is also successful. Amperometric H2O2 sensing canalso been realized with a sensitivity of 139.9 mu A mM(-1)cm(-2), a linear range from 2 mu M to 28 mM, and adetection limit of 1 mu M (S/N = 3). This nanoarray architecture holds great promise as an attractive sensing platform toward electrochemical small molecules detection. (C) 2017 Published by Elsevier B.V.

Abstract  Cobalt-rich slag from blister refining is leached with an oxidising acid, and Co3O4 powder is prepared by an ozonation-precipitation-calcination method after iron has been removed from the solution by the goethite process at different pH values. The effects of stirring speed, gas flow rate, ozone concentration, pH and solution temperature on the precipitation rate of cobalt are investigated. The solution pH has an obvious effect on the precipitation rate, as do the stirring speed, gas flow rate and ozone concentration, but the temperature has little effect. With almost all the cobalt precipitated from the solution, the losses of copper and zinc are about 10% and 1.5%, respectively. The cobalt is precipitated in the form of amorphous CoOOH, identified by X-ray diffraction and with some physicochemical properties similar to those of cobalt hydroxide. The amorphous CoOOH is transformed into spherical Co3O4 powder by the calcination treatment.

Abstract  A process utilizing ozone as the precipitant for the oxidation-precipitation of cobalt from cobalt chloride solution has been studied. The main factors affecting the oxidation rate such as the stirring speed, solution temperature, ozone partial pressure, initial concentration and flow rate were investigated comprehensively. The results demonstrated that the precipitate was CoOOH and the precipitation reaction is diffusion-controlled. The oxidation rate was independent of the initial concentration or solution temperature. The oxidation rate increases obviously with increasing the stirring speed. The Linear Relationship Between ozone partial pressure or flow rate and oxidation rate was found in this paper.

Abstract  A detailed study of the structural, surface, and gas-sensing properties of nanostructured CoxZn1-xO films is presented. X-ray diffraction (XRD) analysis revealed a decrease in the crystallization degree with increasing Co content. The X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopies (XPS) revealed that the Co2+ions preferentially occupied the Zn2+sites and that the oxygen vacancy concentration increased as the amount of cobalt increased. Electrical measurements showed that the Co dopants not only enhanced the sensor response at low ozone levels (ca. 42 ppb) but also led to a decrease in the operating temperature and improved selectivity. The enhancement in the gas-sensing properties was attributed to the presence of oxygen vacancies, which facilitated ozone adsorption.

Abstract  To obtain insights into the roles of carbon and nitrogen contained in the starting materials in partially oxidized tantalum carbonitride (TaCxNy) oxygen-reduction electrocatalysts, we studied oxygen-reduction-reaction (ORR) behaviors and structural properties of tantalum-oxide-based catalysts prepared by partial oxidation of tantalum carbides (TaC) and nitrides (TaN) under low oxygen pressure with 2%H-2/N-2 based gas at 1000 degrees C. The surface tantalum-oxide phase obtained from TaC were beta-Ta2O5 in whole degree of oxidation (DOO) range, while the both TaON and Ta2O5 were formed in the surface phases obtained by the oxidation of TaN, especially at low DOO regions. The highest ORR response was obtained for beta-Ta2O5 containing partially oxidized TaC (Ta-COs). Although, the local structure of surface oxide phase of beta-Ta2O5 containing partially oxidized TaN (Ta-NOs) are almost identical, Ta-NOs showed no significant ORR responses. Carbon contained in the starting materials, therefore, plays an indispensable role in emergence of ORR activity. (C) 2012 Elsevier Ltd. All rights reserved.

Abstract  A cobalt molybdate catalyst was synthesised by the co-precipitation method and characterized by XRD, BET-surface area measurements, ICP-OES, Raman, TPR, TPO, SEM and SEM-EDX. XRD results showed that the dominant phase in the catalyst is the beta-phase. The ratio of Co : Mo was determined by ICP-OES to be 1 : 1.04. The excess molybdenum is found in the molybdenum trioxide phase as shown by the Raman results. The TPR/O/R/O/R results showed that the catalyst can undergo the redox cycle where cobalt molybdate reduces to the molybdite and spinel form of cobalt molybdate ( by 5% hydrogen) and oxidize back to the cobalt molybdate after oxygen exposure. The catalytic testing was carried out in a continuous flow fixed bed reactor at atmospheric pressure and a temperature range of 350 to 550 degrees C in 50 degrees C intervals with different oxygen content (i.e. C : O ratio of 8 : 0, 8 : 1, 8 : 2, 8 : 3 and 8 : 4) in the reaction mixture. The conversion of n-octane increased with increase in the oxygen content in the reaction mixture, which was accompanied by changes in the selectivity patterns. The dominant products were the octenes and COx at all temperatures and different carbon to oxygen ratios. Furthermore, the selectivity to aromatic products increased with increase in the strength of the oxidising environment in the feed mixture and was dominated by styrene and ethylbenzene ( both products of 1,6-cyclization). The yields of octenes, aromatics, cracked products and COx at 500 degrees C showed that an increase in the oxygen content resulted in a decrease in the yield to octenes and an increase in what can be considered secondary products (i.e. aromatics and COx). The total selectivity percentage of value-added products (i.e. octenes and aromatics) also decreased with increase in the oxygen content, due to the increase in cracked products and COx yields ( which are not considered value added products). Characterization of the spent catalysts at the different conditions showed that the catalyst maintains the cobalt molybdate phase under the 8 : 2, 8 : 3 and 8 : 4 C : O conditions, while complete segregation took place under dehydrogenation conditions and partial segregation occurred at an 8 : 1 C : O ratio.

Abstract  The synthesis of planar chiral N-(4-[2.2]paracyclophanyl)-2'-hydroxyacetophenone imine (5) and its use as a ligand for the copper(II) catalyzed cyclopropanation of styrene and stilbene derivatives using diazoesters is presented. Catalyst loadings of 0.1 mol% gave conversions of >80% (turnover numbers approaching 1000) for styrene and its derivatives. When enantiomerically enriched (R)-5 was used to form the catalyst for cyclopropanation of styrene using ethyldiazoacetate, the cyclopropane products were obtained in a trans/cis ratio of 1.9-1 and 75.8% and 60.5% ee (corrected), respectively. The use of t-butyldiazoacetate resulted in an increased trans/cis ratio of 4.6-1 and 88.2% and 77.9% ee, respectively. Enantioselectivities of up to 95% ee were observed. These are among the highest enantioselectivities observed for asymmetric reactions using catalysts where chirality is solely derived from the paracyclophanyl moiety. When compared to its non-methylated analog, the simple presence of a methyl group on the carbon of the imine moiety in 5 resulted in an average increase in enantioselectivity of ca. 60% ee for a variety of substrates. The origin of this dramatic improvement in selectivity is discussed. (c) 2012 Elsevier B.V. All rights reserved.

Abstract  In this study, effects of saturated acids on physical properties, including hardness, impact strength, flexural properties and thermal properties, of unsaturated polyester or UPE resins prepared from recycled PET bottles and fabrics were investigated. PET was depolymerized by glycolysis reaction with the excess propylene glycol in the presence of zinc acetate as a catalyst. UPE resins were then synthesized by polyesterification of these glycolyzed products with maleic anhydride as an unsaturated diacid as well as succinic acid and adipic acid as a saturated diacid. With the addition of styrene monomer, UPEs were subsequently casted into specimens by crosslinking reaction using methyl ethyl ketone peroxide and cobalt octoate as an initiator and a catalyst, respectively. Physical properties of the cured specimens were then studied. The results showed that, when a saturated acid was incorporated, the hardness of the cured UPE resins decreased due to the decreasing amount of crosslinks. The extended distance between crosslinking sites on molecular chains facilitated load distribution, resulting in the significant improvement of impact strength. The flexural strength was also improved when the small amount of saturated acid was used. The onset thermal degradation temperatures and the glass transition temperatures of the prepared UPE resins were almost unchanged.

Abstract  In this study, five mono and bimetallic xNi-(10-x)Co/SBA-15 catalysts (x = 10, 8, 5, 2 and 0, with a total metallic content of 10 wt%) have been synthesized using a deposition-precipitation (DP) methodology. Catalytic performances on the steam reforming of ethanol reaction (SRE) have been determined and correlated with their physical and chemical state. A nickel content of 5% or higher yields catalytic systems with good activity, high selectivity to hydrogen and a low production of acetaldehyde (less than 5%). However, in the systems where the cobalt is the main component of the metallic phase (8-10%), the selectivity changes, mainly due to the production of an excess of acetaldehyde, which is also reflected in the larger H-2/CO2 ratio. In agreement with previous findings, this important modification in the selectivity comes from the formation of a cobalt carbide phase, where only takes place in the cobalt enriched systems, and is inhibited with nickel content larger than 5%. The formation of this carbide phase seems to be responsible for the decrease of cobalt particle size during the SRE reaction. Even though this cobalt carbide phase is thermodynamically metastable against decomposition to metallic cobalt and graphite carbon, our results have shown that it only reacts and decomposes after a hydrogen treatment at 600 degrees C.

Abstract  A methodology providing access to dumbbell-tipped, metal-semiconductor and metal oxide-semiconductor heterostructured nanorods has been developed. The synthesis and characterization of CdSe@CdS nanorods incorporating ferromagnetic cobalt nanoinclusions at both nanorod termini (i.e., dumbbell morphology) are presented. The key step in the synthesis of these heterostructured nanorods was the decoration of CdSe@CdS nanorods with platinum nanoparticle tips, which promoted the deposition of metallic CoNPs onto Pt-tipped CdSe@CdS nanorods. Cobalt nanoparticle tips were then selectively oxidized to afford CdSe@CdS nanorods with cobalt oxide domains at both termini. In the case of longer cobalt-tipped nanorods, heterostructured nanorods were observed to self-organize into complex dipolar assemblies, which formed as a consequence of magnetic associations of terminal CoNP tips. Colloidal polymerization of these cobalt-tipped nanorods afforded fused nanorod assemblies from the oxidation of cobalt nanoparticle tips at the ends of nanorods via the nanoscale Kirkendall effect. Wurtzite CdS nanorods survived both the deposition of metallic CoNP tips and conversion into cobalt oxide phases, as confirmed by both XRD and HRTEM analysis. A series of CdSe@CdS nanorods of four different lengths ranging from 40 to 174 nm and comparable diameters (6-7 nm) were prepared and modified with both cobalt and cobalt oxide tips. The total synthesis of these heterostructured nanorods required five steps from commercially available reagents. Key synthetic considerations are discussed, with particular emphasis on reporting isolated yields of all intermediates and products from scale up of intermediate precursors.

Abstract  BACKGROUND: Table salt is the most commonly used food additive. Since most of the salt consumed in Iran comes from mines, contamination with heavy metals is a health concern. The commonest salt purification method in Iran is washing with water. But recently, some industries have turned to recrystallization method. The present study aimed to determine the level of essential and non-essential heavy metals in the table salt refined with recrystallization and washing methods.

METHODS: Thirty eight pre-packed salt samples were directly collected from retail market in Shiraz (22 samples refined with recrystallization method and 16 with washing method). The level of lead, cadmium, copper, zinc, nickel and cobalt was determined using Voltammetric method. Daily intakes of lead and cadmium as well as their weekly intakes were calculated.

RESULTS: The levels of lead, cadmium, copper, zinc, nickel and cobalt in recrystallized samples were 0. 30 ± 0.26, 0.02 ± 0.02, 0.11 ± 0.06, 0.34 ± 0.22, 0.15 ± 0.19 and 0.008 ± 0.007 μg/g, respectively, and also 0.37 ± 0.27, 0.017 ± 0.021, 0.19 ± 0.18, 0.37 ± 0.20, 0.13 ± 0.23 and 0.037 ± 0.06 μg/g in washed salt samples. The calculated weekly intake of lead and cadmium was 0.216 and 0.014 μg/kg, respectively for the recrystallized and 0.2653 and 0.0119 μg/kg for the washed salts.

CONCLUSION: All values for toxic metals were lower than the permitted maximum for human consumption as prescribed by Codex and Institute of Standards and Industrial Research of Iran. Only 0.8652-1.0612% of lead and 0.17-0.2% of cadmium PTWIs are received via salt consumption weekly.

Abstract  Some heteropoly salts - mesoporous silica composites were prepared from Co salt of molybdophosphoric acid CoHPMo12O40(CoHPM) by supporting on mesoporous silica in different concentrations (20-40 wt% CoHPM) of active phase. The acidity of composites was studied by the adsorption of ammonia and its temperature programmed desorption - TPD using thermogravimetry. The evolved gases during the adsorption-desorption of ammonia on CoPM-silica composites were identified by online mass spectrometry coupled with thermal gravimetry technique. The elemental concentrations based on the relative area of XPS spectra components for Co 2p, Mo 3d, Si 2p and O 1s were obtained for the surface of CoHPM/silica. The dehydration of ethanol was used to probe the catalytic properties of the CoHPM samples incorporated on the silica matrix. The main reaction products obtained on acid (dehydration) catalytic centres were ethylene and diethyl ether, besides acetaldehyde which was obtained on redox (dehydrogenation) catalytic centres. It is shown that silica - supported catalysts, appeared to be more active than bulk CoHPM catalyst in dehydration and dehydrogenation reactions. The higher values of dehydration and reaction products formation are obtained with the lowest loading (20 wt% CoHPM) and as a consequence the highest dispersion of active phase. The ethanol conversion and the carbon selectivity to the primary compounds were investigated during time on stream in order to study the stability and regenerability of supported catalysts. (c) 2017 Elsevier B.V. All rights reserved.

Abstract  Pre-treatment process carried out on raw municipal solid waste incineration (MSWI) fly ash (FA) sample that did not comply initially with the USEPA method 1311 toxicity characteristic leaching procedure (TCLP) regulatory limits of 2011 reduced its chloride and heavy metal content appreciably, thereby making it compliant with the aforementioned regulatory requirement. More than 98% of each heavy metal was successfully removed. The process was excellent in removing cadmium (Cd) (99.99%) and very good at removing the rest. About 99.96% of Cu was eliminated, 99.96% of cobalt (Co), 99.95% of Zn, 98.61% of Cr, and 98.12% of nickel (Ni). Also, the leachate resulting from these pre-treatment steps met the China (GB 16889-2008) and USEPA method 1311 regulatory standards for safe discharge. The density and compressive strength of all the samples prepared increased as the FA content decreased. The compressive strength of all the samples passed the 1989 USEPA-recommended value of 0.34 MPa (50 psi), thereby making them suitable for industrial application. The sample that attained the highest compressive strength (2.08 MPa) after 28 days of curing incorporated 55% fly ash (FACS55), while the one with the least compressive strength (0.65 MPa) after the same period was made from only fly ash (FACS100). Moreover, the concentration of heavy metals in all the samples generally decreased with the FA content. Chromium was not detected in all the samples, thereby making this an excellent method for its immobilization. From the leachability test results, all the samples prepared met the USEPA method 1311 TCLP regulatory limits.

Abstract  The determination of several trace elements [arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), molybdenum (Mo), nickel (Ni), and lead (Pb)] in plant samples using inductively coupled plasma-mass spectrometry (ICP-MS) was evaluated. It was established experimentally that moderate amounts (0.2-2%) of dissolved solids decreased the analyte signals significantly. Internal standardization with Rh was efficiently used to compensate for these matrix effects. The accuracy of the method was verified using reference materials digested according to two different procedures: dry ashing and microwave digestion. No significant differences were observed between measured concentrations and certified values. The investigation was next extended for the determination of major elements [aluminum (Al), boron (B), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), sodium (Na), phosphorus (P), and zinc (Zn)] on the same reference materials. The ICP-MS values agree well with the values supplied. However, it appeared that Sc was the most useful internal standard for major elements.

Abstract  An alkyne tetracarbonyl dicobalt complex with a chelated phosphine-alkene ligand, in which the phosphorus atom and the alkene from the ligand are attached to the same cobalt atom has been prepared, isolated, and characterized by X-ray crystallography. The complex serves as a mechanistic model for an intermediate of the Pauson-Khand (PK) reaction. Although the alkene fragment is located in an equatorial coordination site with an appropriate orientation, and, therefore, should undergo insertion, it failed to give the PK product upon either thermal or N-methylmorpholine N-oxide activation. However, a phosphine-alkene complex that contains a terminal alkene readily provided the corresponding PK product. We attribute this change in reactivity to the different ability of each olefin to undergo 1,2-insertion. These results provide further insights into the factors that govern a crucial step in the PK reaction, the olefin insertion.

Abstract  Antimicrobial properties of sulfur, nitrogen, and oxygen bonded organoboron (III) complexes with biologically potent ligands viz., 2-hydroxy-N-phenyl benzamide hydrazine carboxamide(HONOH), 2-hydroxy-N-phenyl benzamide hydrazine carbothioamide (HONSH), and 2-hydroxy-N-phenyl benzamide hydrazine carbodithioic acid (HONSH), have been studied. The unimolar and bimolar reactions of triisopropoxy borane with dibasic tridentate ligands resulted in the formation of colored solids, which have been characterized by elemental analysis, molecular weight determinations, and conductance measurements. The UV, IR, and NMR (1H, 13C, and 11B) spectral studies indicate a tetra-coordinated geometry for the resulting complexes. The ligands and their complexes have been screened for their fungicidal and bactericidal activities, and the results indicate that they exhibit significant antimicrobial properties. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Abstract  Mipu1 (myocardial ischemic preconditioning up-regulated protein 1), recently identified in our lab, is a novel zinc-finger transcription factor which is up-regulated during ischemic preconditioning. However, it is not clear what transcription factor contributes to its inducible expression. In the present study, we reported that HIF-1 regulates the inducible expression of Mipu1 which is involved in the cytoprotection of HIF-1α against oxidative stress by inhibiting Bax expression. Our results showed that the inducible expression of Mipu1 was associated with the expression and activation of transcription factor HIF-1 as indicated by cobalt chloride (CoCl2) treatment, HIF-1α overexpression and knockdown assays. EMSA and luciferase reporter gene assays showed that HIF-1α bound to the hypoxia response element (HRE) within Mipu1 promoter region and promoted its transcription. Moreover, our results revealed that Mipu1 inhibited the expression of Bax, an important pro-apoptosis protein associated with the intrinsic pathway of apoptosis, elevating the cytoprotection of HIF-1 against hydrogen peroxide (H2O2)-mediated injury in H9C2 cells. Our findings implied that Bax may be a potential target gene of transcription factor Mipu1, and provided a novel insight for understanding the cytoprotection of HIF-1 and new clues for further elucidating the mechanisms by which Mipu1 protects cell against pathological stress.

Abstract  In this work were characterized the palettes of some of the most representative Brazilian painters from the XIX century: Eliseu Visconti, Almeida Junior, Rodolfo Amoedo, Henrique Bernardelli, Rafael Frederico, Modesto Brocos, Augusto Rodrigues Duarte and Pedro Peres. EDXRF measurements were carried out with a portable system consisting of an X-ray tube Oxford TF3005 and a Si-PIN XR-100CR detector from Amptek. Some pigments identified were: zinc and lead white, ochre, umber, vermilion, Prussian blue, cobalt blue, cadmium yellow, black iron oxide, etc.

Abstract  Metal toxicity is a global environmental challenge. Fish are particularly prone to metal exposure, which can be lethal or cause sublethal physiological impairments. The objective of this study was to investigate how adverse effects of chronic exposure to non-toxic levels of essential and non-essential metals in early life stage zebrafish may be explained by changes in the transcriptome. We therefore studied the effects of three different metals at low concentrations in zebrafish embryos by transcriptomics analysis. The study design compared exposure effects caused by different metals at different developmental stages (pre-hatch and post-hatch). Wild-type embryos were exposed to solutions of low concentrations of copper (CuSO4), cadmium (CdCl2) and cobalt (CoSO4) until 96h post-fertilization (hpf) and microarray experiments were carried out to determine transcriptome profiles at 48 and 96hpf. We found that the toxic metal cadmium affected the expression of more genes at 96hpf than 48hpf. The opposite effect was observed for the essential metals cobalt and copper, which also showed enrichment of different GO terms. Genes involved in neuromast and motor neuron development were significantly enriched, agreeing with our previous results showing motor neuron and neuromast damage in the embryos. Our data provide evidence that the response of the transcriptome of fish embryos to metal exposure differs for essential and non-essential metals.

Abstract  The influence of salts of heavy metals on trypsin-like peptide hydrolase of drosophila larvae partly refined by methods of salting-out, gel chromatography and electrophoresis has been researched. It is established that cadmium chloride is characterized by the greatest inhibitory effect, while zinc chloride by the lowest one. Since metal chlorides were used in all cases, it is the differentiated effect of metal ions on manifestations of amidase activity of trypsin-like peptide hydrolase of drosophila larvae, which rather may be considered as proved than the effect of chlorine ions. This, as a whole, agrees with the effect of these ions on proteolytic digestion system at the level of live organisms.