Enhancement of Thermoelectric Behavior of La0.5Co4Sb12−x Te x Skutterudite Materials

Metallurgical and Materials Transactions A - In this work, the effects of Te doping on the microstructure and thermoelectric properties of the partially filled skutterudite La0.5Co4Sb12 compounds...     

Adsorptive removal of veterinary antibiotics from water using an integrated photocatalyst (IPCA)

ABSTRACT

The synthesising of a novel catalyst known as the integrated photo-catalysts (IPCA) by impregnating activated carbon (AC) with titanium dioxide (TiO₂) particles by ultra-sonication was used. The kinetics of antibiotics removal using adsorption and photodegradation were monitored and modelled. The effects of photocatalyst concentration and solution pH were investigated. Maximum removal percentages for both AC and IPCA were above 50% for an initial concentration of 100 mg/L. Adsorption using AC and IPCA followed the Langmuir and Freundlich isotherms. Higher coefficients of correlation were obtained for the Langmuir isotherms for four of the antibiotics. With regard to the photodegradation, it was found that photocatalysis attained almost 100% degradation of the target contaminants. Complete degradation was achieved within half-lives of 60 to 102 minutes for all the compounds. Although both photo-catalysts effectively degraded the contaminants, the IPCA had the unique advantages of possessing both adsorptive and photocatalytic properties.     

Central haemodynamic and forearm vascular effects of morphine in patients after open heart surgery

Central haemodynamic and forearm vascular changes following administration of morphine i.v. were studied in patients 24--30 h after open heart surgery. Right atrial pressure, heart rate, mean arterial pressure, cardiac output and stroke volume were measured before and after morphine 5 and 10 mg per 70 kg in 14 subjects. In a further group of eight subjects, forearm blood flow was measured after morphine 10 mg per 70 kg. Total systemic and forearm vascular resistance were derived from these measurements. In spite of wide individual variations, significant decreases in mean arterial pressure occurred in most of the patients and appeared to be dose related. Significant decreases in mean cardiac index were noted only after morphine 10 mg per 70 kg. Forearm blood flow increased consistently and significantly and there was a corresponding decrease in vascular resistance. The decrease in mean arterial pressure and the change in forearm vascular resistance indicated that vasodilatation was probably the principle cause of the decrease in arterial pressure, whereas the sustained decrease in cardiac output seemed to indicate an effect on venous capacitance. The predominant action of morphine appears to be peripheral, causing a decrease in vascular resistance and, possibly, an increase in venous capacitance.     

Analysing wear behaviour of Al–CaCO3 composites using ANN and Sugeno-type fuzzy inference systems

Neural Computing and Applications - Design of experiment for the development of stir cast calcium carbonate-reinforced aluminium composite is a search for optimum combination of material and...     

Formulation of silver chloride/poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (AgCl/PHBV) films for potential use in bone tissue engineering

Orthopedic implant failure due to bacterial infection has been a concern in bone tissue engineering. Here, we have formulated a composite made of biodegradable polymer, i.e., poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and silver chloride. Ag⁺ ions released from the AgCl/PHBV film can promote an aseptic environment by promoting inhibition of bacterial growth while maintaining bone cell growth, depending on AgCl loading. The objective of this study is to formulate AgCl/PHBV film(s) of varying composition so as to evaluate the dependence of AgCl loading in the film on antimicrobial activity and cytotoxicity. The release kinetics of silver ions from AgCl/PHBV film in aqueous and Dulbecco's Modified Eagle Medium showed similarity in the initial burst of ions during the first day of desorption followed by a gradual release of ions over extended time period. The antibacterial efficacy of AgCl/PHBV film against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa was evaluated by microbiological assay, while cytotoxicity of the film toward MC3T3‐E1 cells was determined by MTT assay. For all compositions studied, a clear zone of inhibition around AgCl/PHBV film was noticed on a modified Kirby‐Bauer disk diffusion assay. We established that MC3T3‐E1 cell attachment on AgCl/PHBV film is strongly related to loading of AgCl in the film. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45162.     

Dehydrocyanation of cultivars of lima bean (Phaseolus lunatus L) and its effect on tryptophan content

Three cultivars (red, black and white) of lima bean were studied to determine the best medium in which to cook them in order to reduce their hydrocyanic acid content to tolerable levels. The study also investigated the effects of processing media on the trytophan content of lima beans. Samples of each cultivar were parboiled in each of three media, 0.94 M HCl, 0.47 M H₂SO₄ and distilled water, for various times. Portions of each cultivar were also parboiled in the three media after enzyme incubation. Boiled samples were dried, pulverised and analysed for cyanide and tryptophan contents. There were 96.82, 99.78 and 99.62% reductions in cyanide content of the red cultivar after boiling in water, dilute HCl and dilute H₂SO₄ respectively for 30 min. The corresponding values for the white cultivar were 96.39, 99.59 and 94.77% respectively. Dehydrocyanation was more effective in enzyme‐incubated samples when they were parboiled in dilute mineral acids. The residual cyanide content in enzyme‐incubated samples was below tolerable limits after 30 min of treatment. However, the longer the parboiling time, the higher was the trytophan loss. Therefore parboiling for 30 min in dilute HCl will produce the desired result of insignificant residual cyanide content and minimal tryptophan loss in all samples. Copyright © 2004 Society of Chemical Industry     

MR of hippocampal sclerosis: comparison of qualitative and quantitative assessments

We describe a patient with dysgerminoma who had elevated serum inhibin, tumor-associated trypsin inhibitor (TATI), and CA 125 concentrations, which increased progressively during follow-up of the advancing disease. Inhibin levels correlated closely with disease behavior. In contrast to inhibin, serum TATI and CA 125 failed to reveal the presence of silent disease.     

Oxygen modulation of guanylate cyclase-mediated retinal pericyte relaxations with 3-morpholino-sydnonimine and atrial natriuretic peptide

PURPOSE: This study explores at which level of the guanylate cyclase pathway oxygen modulates retinal pericyte relaxation induced by nitric oxide (NO). METHODS: Bovine retinal microvascular pericytes were grown on silicone. On silicone, pericyte contractile tone induces wrinkles. Drug-induced relaxation was quantified as a reduced number of wrinkles after exposure to 3-morpholino-sydnonimine (SIN-1) or atrial natriuretic peptide (ANP) in the absence or in the presence of either 0.3 microM methylene blue (MB), a guanylate cyclase inhibitor, or 10 microM hemoglobin, a NO scavenger; and under 100% oxygen (hyperoxia), ambient air (normoxia), or 100% nitrogen (hypoxia). RESULTS: Pericytes were relaxed with SIN-1 and ANP in a concentration-dependent manner (EC50: 0.1 microM and 0.01 microM, respectively). Relaxations induced by SIN-1 or ANP were inhibited (P < 0.001) by MB, whereas hemoglobin inhibited only SIN-1 relaxations (P < 0.001). Relaxations induced by SIN-1, but not by ANP were increased (P < 0.001) under hypoxia and decreased (P = 0.002) under hyperoxia. CONCLUSIONS: SIN-1 and ANP relax pericytes through the activation of guanylate cyclase (inhibited by MB), but only SIN-1 through an extracellular release of NO (inhibited by hemoglobin). That oxygen only modulates pericyte relaxations induced by SIN-1 (NO-mediated) but not those induced by ANP suggests that an interaction between oxygen and NO might participate in the capillary network's blood-flow modulation according to local tissue oxygen tension.     

In vivo and in vitro responses to poly(ethylene terephthalate-co-diethylene glycol terephthalate) and polyethylene oxide blends

Although biocompatible polymeric compounds are generally nontoxic, nonimmunogenic, and chemically inert, implants made from these materials may trigger acute and chronic inflammatory responses. These inflammatory reactions may induce degeneration of implanted biopolymer. Interactions between implanted biomaterial and inflammatory cells are mediated by many cellular events involving cellular adhesion and activation. We studied the inflammatory responses in vivo and in vitro to samples of biopolymers composed of poly(ethylene terephthalate-co-diethylene glycol terephthalate) plus 0, 5, 25% of polyethylene oxide. We observed that these biopolymers did not induce inflammatory responses when implanted in the peritoneal cavity of mice for 28 days. However we observed deposition of hyaluronic acid at the surface of implanted biomaterial, suggesting that tolerance to biomaterial occurred after surgical implantation. No significant adhesion of inflammatory cells such as mononuclear phagocytes and peripheral leukocytes were observed in vitro, when poly(ethylene terephthalate-co-diethylene glycol terephthalate) blends were used as substratum to cellular adhesion. These results suggest that blends composed of poly(ethylene terephthalate-co-diethylene glycol terephthalate) induce low inflammatory cell adhesion, since no rejection of biopolymer was observed when implanted in experimental animal models.