The influence of the deposition time on morphological and optical properties of Cu x S films deposited on polypropylene substrate

Copper sulfide (Cu _x S) films deposited on polypropylene substrate were obtained by chemical bath deposition (CBD) method. The influence of the deposition time on the morphology of Cu _x S films was studied by means of scanning electron microscopy. We have found that the average particles dimension increased from 37 to 49 nm with the increase of deposition time from 20 to 30 minutes. The study of optical properties of the copper sulfide films was carried out based on optical transmission spectra recorded in the 400–1000 nm wavelength range. The optical constants, such as refractive index, extinction coefficient and dielectric constant as well as electrical and optical conductivity of Cu _x S films were calculated. The obtained values are in accordance with the ones reported in the literature:We have shown that both, morphological and optical properties of Cu _x S films are strongly affected by the deposition time.     

Copolymers of glycerol and propylene glycol diglycidyl ethers with aromatic dithiols

Monomers derived from renewable recourses have the potential to become the biobased alternatives for petroleum derived chemicals in the production of polymers. Glycerol, the byproduct of biodiesel refining, and propylene glycol derived from glycerol are promising candidates which can be used in the synthesis of polymers as they are or after chemical modification. The new copolymers of glycerol and propylene glycol diglycidyl ethers with aromatic dithiols were synthesized and investigated in this study. Their chemical structures were confirmed by IR, ¹H‐NMR spectroscopy, and gel permeation chromatography. The dependencies of the mechanical, thermal properties, swelling in the different solvents, biodegradability, and bioresistance of synthesized copolymers on their chemical structures were studied. The properties of some synthesized copolymer films were found to be comparable with those of commodity polymer films. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4367–4374, 2013     

Nanocrystalline/Nanosized Ni1−γFe2+γO4 Ferrite Obtained by Contamination with Fe During Milling of NiO–Fe2O3 Mixture. Structural and Magnetic Characterization

The nanocrystalline nickel ferrite (NiFe₂O₄) was synthesized by reactive milling starting from equimolar mixture of oxides. The iron contamination during milling leads to a solid state reaction between Fe and NiFe₂O₄ spinel. This reaction starts for a milling time longer than 30 h. A mixed nickel–iron ferrite (Ni_1?γFe_2+γO₄) and elemental Ni are obtained. The evolution of the nickel–iron mixed ferrite during milling and its properties were investigated using X‐ray diffraction, Fourier Transform Infrared Spectroscopy (FTIR), Laser Particles Size Analyzer and magnetic measurements. Annealing treatment (350°C/4 h in vacuum) is favorable to the reaction between phases. Replacement of Ni²⁺ cations by iron cations provided by contamination leads to the increase of lattice parameter value of the spinel structure. The magnetization of the nickel–iron mixed ferrite newly formed is larger than the nickel ferrite magnetization (13.6 μ_B/f.u. and 6.22 μ_B/f.u., respectively), due to the magnetic moment of Fe²⁺ cation which is double as compared to the Ni²⁺ cation. Magnetization of the milled samples decreases during milling due to the structural changes induced by milling in the nickel–iron mixed ferrite. The annealing induces a reordering of the cations which leads to a larger magnetization.     

A comparative study of natural, formaldehyde-treated and copolymer-grafted orange peel for Pb(II) adsorption under batch and continuous mode

Natural, formaldehyde-treated and copolymer-grafted orange peels were evaluated as adsorbents to remove lead ions from aqueous solutions. The optimum pH for lead adsorption was found to be pH 5. The adsorption process was fast, reaching 99% of sorbent capacity in 10 min for the natural and treated biomasses and 20 min for the grafted material. The treated biomass showed the highest sorption rate and capacity in the batch experiments, with the results fitting well to a pseudo-first order rate equation. In the continuous test with the treated biomass, the capacity at complete exhaustion was 46.61 mg g(-1) for an initial concentration of 150 mg L(-1). Scanning electronic microscopy and energy dispersive X-ray spectroscopy indicated that the materials had a rough surface, and that the adsorption of the metal took place on the surface. Fourier transform infrared spectroscopy revealed that the functional groups responsible for metallic biosorption were the -OH, -COOH and -NH(2) groups on the surface. Finally, the thermogravimetric analysis indicates that a mass reduction of 80% can be achieved at 600 degrees C.     

Characterization of aerosols containing Zn, Pb, and Cl from an industrial region of Mexico City

Recent ice core measurements show lead concentrations increasing since 1970, suggesting new nonautomobile-related sources of Pb are becoming important worldwide (1). Developing a full understanding of the major sources of Pb and other metals is critical to controlling these emissions. During the March, 2006 MILAGRO campaign, single particle measurements in Mexico City revealed the frequent appearance of particles internally mixed with Zn, Pb, Cl, and P. Pb concentrations were as high as 1.14 microg/m3 in PM10 and 0.76 microg/m3 in PM2.5. Real time measurements were used to select time periods of interest to perform offline analysis to obtain detailed aerosol speciation. Many Zn-rich particles had needle-like structures and were found to be composed of ZnO and/or Zn(NO3)2 x 6H2O. The internally mixed Pb-Zn-Cl particles represented as much as 73% of the fine mode particles (by number) in the morning hours between 2-5 am. The Pb-Zn-Cl particles were primarily in the submicrometer size range and typically mixed with elemental carbon suggesting a combustion source. The unique single particle chemical associations measured in this study closely match signatures indicative of waste incineration. Our findings also show these industrial emissions play an important role in heterogeneous processing of NO(y) species. Primary emissions of metal and sodium chloride particles emitted by the same source underwent heterogeneous transformations into nitrate particles as soon as photochemical production of nitric acid began each day at approximately 7 am.     

Phenolic acids and flavonoids profiles of extracts from edible wild fruits and their antioxidant properties

In this study, the total phenolic, total flavonoids, phenolic compounds, the mineral content, and antioxidant activity of fruit extracts of seven wild species (Crataegus monogyna Jacq., Prunus spinosa L., Rosa canina L., Hippophaë rhamnoides L., Rubus fruticosus L., Prunus padus, Cornus mas L.) were investigated. The results indicated significant differences (p < 0.05) in the total phenolics and total flavonoids content, between the seven analyzed species. These ranged from 184.69 to 727.29 mg GAE/100 g FW and 17.27 to –165.55 mg QE/100 g FW, respectively. The antioxidant activity found in fruits was not directly affected by the total phenolic content (TPC). This activity was linked to a larger extent to the type of individual phenolic compounds and to a lesser extent to the TPC, because fruits with higher TPC have not always presented the highest values of antioxidant activity. HPLC analysis of methanolic extract showed the presence of phenolic acids (i.e. gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salycilic, elagic, and trans-cinnamic) and flavonoids (i.e. catechin, epicatechin, rutin, myricetin, and quercetin). Significant differences (p < 0.05) were observed in each individual mineral between fruits from wild flora. The fruits tissues of wild species turned out to be a good source of calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), manganese (Mn), copper (Cu), chromium (Cr), zinc (Zn), and boron (B). The results demonstrated that wild species possessed great potential for food production as sources of bioactive compounds such as phenolic compounds and minerals, for food supplements or functional foods.     

Asymmetric Dimethylarginine Is a Marker of Endothelial Dysfunction in Thrombotic Antiphospholipid Syndrome Patients

Objective: The potential contribution of asymmetric dimethylarginine (ADMA) and high-sensitivity C reactive protein (hsCRP) to endothelial dysfunction in APS patients has not been studied in detail, until now. The study involved 105 APS patients (59 diagnosed with primary APS (PAPS) and 46 APS associated with systemic lupus erythematosus (SAPS)) who were compared to 40 controls. Endothelial dysfunction was assessed by measurement of flow-mediated dilatation (FMD) and glyceryl trinitrate dilatation (NMD) of the brachial artery. ADMA (micromol/L) was analyzed by ELISA. Results: FMD in patients with APS was significantly lower than that of the controls (p < 0.001), with no difference between the PAPS and the SAPS groups. ADMA and hsCRP concentrations were significantly higher in the patient cohort than in the control group (p < 0.001, p = 0.006, respectively), as was the case with the SAPS group as compared to the PAPS group (p < 0.001, p = 0.022, respectively). FMD impairment correlated to ADMA (ρ 0.472, p < 0.001) and to hsCRP (ρ 0.181, p = 0.033). In the regression model, the ADMA concentration confirmed the strength of its association (B 0.518, SE 0.183, Wald 8.041, p = 0.005, Exp(B) 1.679, 95% CI 1.174–2.402) to FMD impairment. The synergistic probability model of ADMA and hsCRP caused FMD impairment when the positivity of β2GPIIgG was added. ADMA may be used as a simple and low-cost tool for verifying the presence of endothelial dysfunction in APS patients. According to the results of the study, we could presume that hsCRP, together with aPL, has a preparatory effect on the endothelium in causing endothelial dysfunction.     

The Yin/Yang Balance of Communication between Sensory Neurons and Macrophages in Traumatic Peripheral Neuropathic Pain

Traumatic peripheral neuropathic pain is a complex syndrome caused by a primary lesion or dysfunction of the peripheral nervous system. Secondary to the lesion, resident or infiltrating macrophages proliferate and initiate a cross-talk with the sensory neurons, at the level of peripheral nerves and sensory ganglia. The neuron–macrophage interaction, which starts very early after the lesion, is very important for promoting pain development and for initiating changes that will facilitate the chronicization of pain, but it also has the potential to facilitate the resolution of injury-induced changes and, consequently, promote the reduction of pain. This review is an overview of the unique characteristics of nerve-associated macrophages in the peripheral nerves and sensory ganglia and of the molecules and signaling pathways involved in the neuro-immune cross-talk after a traumatic lesion, with the final aim of better understanding how the balance between pro- and anti-nociceptive dialogue between neurons and macrophages may be modulated for new therapeutic approaches.     

Gold-standard and improved framework for sperm head segmentation

Semen analysis is the first step in the evaluation of an infertile couple. Within this process, an accurate and objective morphological analysis becomes more critical as it is based on the correct detection and segmentation of human sperm components. In this paper, we present an improved two-stage framework for detection and segmentation of human sperm head characteristics (including acrosome and nucleus) that uses three different color spaces. The first stage detects regions of interest that define sperm heads, using k-means, then candidate heads are refined using mathematical morphology. In the second stage, we work on each region of interest to segment accurately the sperm head as well as nucleus and acrosome, using clustering and histogram statistical analysis techniques. Our proposal is also characterized by being fully automatic, where a user intervention is not required. Our experimental evaluation shows that our proposed method outperforms the state-of-the-art. This is supported by the results of different evaluation metrics. In addition, we propose a gold-standard built with the cooperation of a referent expert in the field, aiming to compare methods for detecting and segmenting sperm cells. Our results achieve notable improvement getting above 98% in the sperm head detection process at the expense of having significantly fewer false positives obtained by the state-of-the-art method. Our results also show an accurate head, acrosome and nucleus segmentation achieving over 80% overlapping against hand-segmented gold-standard. Our method achieves higher Dice coefficient, lower Hausdorff distance and less dispersion with respect to the results achieved by the state-of-the-art method.