Nanocrystallitics of Zinc Oxide containing different amounts of Europium (Zn(1-X)EuxO – it being 0,0 ≤ x ≤ 0,035) were synthesized by a combustion reaction, with the aim of evaluating the effect of the concentration of Eu3+ in magnetic properties, after obtained. The chemical composition was determined by energy dispersive spectroscopy, X-ray (EDS). The structural characterization was performed by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetrics Analysis (TGA), Spectroscopy Photoelectrons Excited by X-Rays (XPS) and Transmission Electron Microscopy (TEM). Crystallinestructure powders of ZnO in wurtzita were formed after the thermical treatment at 550°C about one hour, with average size crystallites of 20 nm. The X-Ray Diffraction results showed presence of diffraction peaks of well-defined of ZnO primary characteristic phase and traces of oxide Europium (Eu2O3) as secondary stage for samples doped with 3.5% of Eu3+. The analyzes showed the magnetic samples exhibit ferromagnetism at room temperature dependent content of ions Eu3+, but for the sample doped with 3.5% Europium the magnetization drops considerably, due to the formation of Oxide Europium (Eu2O3) non-magnetic. This fact suggests that the ferromagnetism of samples is associated with the Eu3+ ions, it is occupying the interstices of matrix semiconductor wafer.

Organylzinc chalcogenolate mediated hydrochalcogenation of propargyl alcohols organylzinc chalcogenolate (chalcogen = sulfur, selenium and tellurium) prepared from the reductive cleavage of diorganyl dichalcogenide bonds by the Zn/NH4OH system led to organylzinc chalcogenolates that provide an alternative synthetic route to produce carbon-chalcogen bonds. This work presents new synthetic methodology and discusses the general aspects and limitations of organylzinc chalcogenolate to promote the hydrochalcogenetion of 2-alkyn-1-ol derivates leading mainly the Markovnikov allylic alcohols bearing a vinylic chalcogenide substituints. We investigated the chemo, regio- and stereoselctivity for this protocol in two different systems: in aqueous medium and in organic medium.

OBJECTIVE: To assess the relationship of blood lead and hemoglobin, zinc protoporphyrin, and ferritin concentrations in children. METHODS: A cross-sectional study was carried out in 136 anemic and non-anemic children from two rural villages near a lead smelter in Adrianópolis, Southern Brazil, from July to September 2001. Hemoglobin electrophoresis was performed to exclude children with hemoglobin variants and thalassemia syndromes associated with anemia. Lead was determined by atomic absorption spectrophotometry; hemoglobin by automated cell counting; zinc protoporphyrin by hematofluorometry; ferritin by chemiluminescence. Student's t-test, Mann-Whitney test, and the c² test were used to assess the significance of the differences between the variables investigated in anemic and non-anemic children. Stepwise multivariate linear regression analysis was performed using two models for anemic and non-anemic children respectively. RESULTS: Lead was negatively associated to hemoglobin (p

No presente estudo foram investigadas as respostas fisiológicas da alga vermelha Porphyra haitanesis às elevadas concentrações de cobre (acima de 50 μM) e de zinco (acima de 100 μM). Os resultados mostram que os efeitos de Cu2+ e Zn2+ sobre o crescimento, pigmentos fotossintéticos (clorofilas e carotenóides), ficobiliproteína e metabolismo (o espectro de emissão de fluorescência e as atividades do fotossistema) não seguem o mesmo padrão. A taxa de crescimento relativo foi inibida por diferentes concentrações de Cu2+ e, em presença de Zn2+, aumentou ligeiramente em baixas concentrações (abaixo de 10 μM) e foi inibida em altas concentrações. Por outro lado, os teores de ficoeritrina apresentaram leve aumento em concentrações relativamente baixas de Cu2+ e Zn2+ (até 1 μM Cu2+ e até 20 μM Zn2+, respectivamente) e foram inibidas por altas concentrações. Além disso, tanto a fotossíntese quanto a respiração mostraram aumento nas trocas de oxigênio em resposta às concentrações relativamente baixas de Cu2+ (até 1 μM) e de Zn2+ (até 10 μM), além da redução em concentrações relativamente altas desses metais. Adicionalmente, as atividades fotoredutoras e as emissões de fluorescência do fotossistema II (PSII) foram incrementadas em baixas concentrações de Cu2+ (até 0,1 μM) e de Zn2+ (até 10 μM) e inibidas por altas concentrações. Desta forma, a intensidade da fluorescência da clorofila-a e dos centros de reação ativa PSII seguiram um padrão semelhante em resposta às elevadas concentrações de Cu2+ e Zn2+. Esses resultados sugerem que baixas concentrações de Cu2+ e Zn2+ afetam o metabolismo de P. haitanesis, que se torna inibido por altas concentrações desses metais.

Recent studies have demonstrated that 30% of the world’s population suffers of anemia, half of the cases are related to iron deficiency, and the most common treatment is the use of iron supplementation. In this framework, the iron and zinc determination from different dietary supplements was performed by flame atomic absorption spectrophotometry. Concerning the dissolution of supplements, direct acid dissolution, wet digestion, and microwave digestion (MW) techniques were used for sample preparation. The iron and zinc recovery results demonstrated that the MW technique was the most appropriate for all of the supplements with the highest metal recovery yields. Moreover, the method validation parameters referred to a linear range for iron of 0.1-4 mg L-1 with a regression coefficient (R2) of 0.9998 ± 0.002, while for zinc it was 0.01-1 mg L-1 (R2 = 0.9997 ± 0.003). The limit of detection and quantification values were calculated as 0.03 and 0.09 mg L-1 for iron and 0.01 and 0.02 mg L-1 for zinc, respectively. The accuracy of the method was evaluated from the % recovery yield for iron and zinc, which, respectively, resulted in an oscillate of 99.2% to 102%, and 99.4% to 100.4% for the dietary investigated supplements. The precision of the method was determined by intra-day and inter-day precision with a relative standard deviation that was <2.0%.

Objectives: This study investigated the physical and mechanical properties, antibacterial effect and biocompatibility of novel elastomeric temporary resin-based filling materials (TFMs) containing zinc methacrylate (ZM). Material and Methods: Experimental TFMs were prepared by mixing the zinc methacrylate with monomer, co-monomer, photoinitiator and fillers. A ZM concentration of 0 (control), 0.5% (Z0.5); 1% (Z1), 2% (Z2), or 5% (ZM5) wt% was added to the TFMs. Fermit-N (F) was used for comparison with the experimental material. Microleakage, water sorption/solubility, degree of conversion, depth of cure, ultimate tensile strength, and hardness were determined and compared. A modified direct contact test (DCT) with Enterococcus faecalis and a Streptococcus mutans' biofilm accumulation assay was carried out to evaluate the antimicrobial effect and cytotoxicity of the assay. Statistical comparisons were performed (α=5%). Results: The results showed that the physical and mechanical properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference and some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values. TFMs with ZM killed E. faecalis only after 1 h. Biofilm development of S. mutans was not affected by the inclusion of ZM in the experimental TFMs. Conclusions: The present findings suggest that the physical, mechanical and biological properties of the experimental TFMs with ZM are comparable with the properties of the commercial reference. However, some properties were improved, such as lower microleakage and water sorption, and higher ultimate tensile strength values.

OBJECTIVE: To identify the impact of supplemental zinc, vitamin A, and glutamine, alone or in combination, on long-term cognitive outcomes among Brazilian shantytown children with low median height-for-age z-scores. METHODS: A randomized, double-blind, placebo-controlled trial was conducted in children aged three months to nine years old from the urban shanty compound community of Fortaleza, Brazil. Demographic and anthropometric information was assessed. The random treatment groups available for cognitive testing (total of 167 children) were: (1) placebo, n = 25; (2) glutamine, n = 23; (3) zinc, n = 18; (4) vitamin A, n = 19; (5) glutamine+zinc, n = 20; (6) glutamine+vitamin A, n = 21; (7) zinc+vitamin A, n = 23; and (8) glutamine+zinc+vitamin A, n = 18. Neuropsychological tests were administered for the cognitive domains of non-verbal intelligence and abstraction, psychomotor speed, verbal memory and recall ability, and semantic and phonetic verbal fluency. Statistical analyses were performed using SPSS, version 16.0. ClinicalTrials.gov: NCT00133406. RESULTS: Girls receiving a combination of glutamine, zinc, and vitamin A had higher mean age-adjusted verbal learning scores than girls receiving only placebo (9.5 versus 6.4, p = 0.007) and girls receiving zinc+vitamin A (9.5 versus 6.5, p = 0.006). Similar group differences were not found between male study children. CONCLUSIONS: The findings suggest that combination therapy offers a sex-specific advantage on tests of verbal learning, similar to that seen among female patients following traumatic brain injury.

Prostate cancer is one of the most common causes of cancer death in men and the treatment options are limited for advanced prostate cancer. Zinc is a vital metal ion that plays a crucial role in prostate physiology. Zinc is particularly concentrated in normal prostate cells, being mainly used for citrate secretion. On the other hand, Zinc levels are heavily reduced in prostate cancer, which lead to a more energy-efficient metabolic state. Interestingly, Zinc has also been shown to negatively affect MAPK signalling. In this study, DU-145 and PC-3 prostate cancer cell lines were tested with ZnSO4 for the assessment of the phosphorylation of KSR1, a scaffold protein of the MAPK/ERK 1/2 pathway. Our findings revealed that only the DU-145 cell line transfected with KSR1 plasmid presented detectable phosphorylation levels of KSR1. To overcome the scarce uptake of Zinc by prostate cancer cell lines, the transformed K1-4 cells were used to prove the modulation of ERK 1/2 activity by KSR1. This role of KSR1 was confirmed by MEK and KSR1 inhibitors that demonstrated that the inhibition of KSR1 results in diminished ERK 1/2 activation. This correlates with the hypothesis that the Zinc-induced phosphorylation of KSR1 leads to lower ERK 1/2 activity. KSR1 can be therefore considered as a new valid target for the development of prostate cancer therapies.

The increasing average life expectancy and the increasing need to improve existing therapeutic techniques have led to the development of new approaches to tissue engineering. The use of bioactive glasses as biomaterials for tissue recovery is a very common practice. However, they have recently been developed to allow the controlled release of clinically beneficial ions, thereby improving their therapeutic effects. One of the disadvantages of these materials is the fact that they generally have properties very different from those of the tissues in which they are implanted. In this sense new materials arose, including the organic-inorganic hybrid materials, which are formed by an inorganic component, such as tetraethyl orthosilicate (TEOS), to which an organic component, polydimethylsiloxane (PDMS) is added. This work follows on from a previous work entitled "Hybrid organic-inorganic borosilicate materials by sol-gel for bone tissue engineering", The novelty of this work consisted of the development of materials in the PDMS-SiO2-B2O3 hybrid system with antibacterial properties through the addition of zinc and copper. Thus, three distinct compositions were developed for each of the systems, changing the amounts of added zinc, or copper, but keeping the remaining reagents constant. For each of the hybrid systems a different protocol was used, but all materials were obtained by the sol-gel method. The materials resulting from the addition of zinc to the PDMS-SiO2-B2O3 hybrid system are porous and white opaque monoliths, while the samples resulting from the addition of copper are monolithic samples with no porosity. The structural analysis of the different materials was performed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and magnetic nuclear resonance (NMR), which allowed to verify the presence of hybrid bonds, due to the existence of the bonds between the organic phase and the inorganic phase (D-Q), as well as characteristic bonds of borosiloxane (B-O-Si). The 1H NMR results, together with the XRD analysis, led to the conclusion that zinc-containing samples had shorter PDMS chains, while in copper-containing samples had longer PDMS chains were present. The 11B NMR analysis allowed to conclude that in copper-containing samples boron is present only in the trigonal form (BO3), However, in the zinc-containing samples, as zinc is an intermediate species that can behave as a network modifier, the change of boron coordination from trigonal (BO3) to tetrahedral (BO4) occurs. The microstructural analysis was performed by determining the specific surface area by Brunauer-Emmett-Teller (BET) method and scanning electron microscopy (SEM), which led to the conclusion that, unlike copper-containing samples, zinc-containing samples have a porous structure with a much larger specific surface area (SSA). The degradation test was performed according to ISO 10993-13 for different immersion times in deionized water: 30 minutes, 1 hour and 5 hours. Subsequently, analysis by inductively coupled plasma optical emission spectrometry (ICP-OES) revealed the ability of the material to release the added ions, zinc and copper. Finally, antibacterial assays performed according to the ASTM E2149 method revealed the ability of the developed materials to reduce bacterial activity for Escherichia coli ATCC 25922 and Staphylococcus aureus NCTC 6871 bacterial strains.