Electrochemical oxidation of water on synthetic boron-doped diamond thin film anodes

Electrolysis in aqueous 1 M HClO₄ and 1 M H₂SO₄ solutions has been carried out under galvanostatic conditions using boron-doped diamond electrodes (BDD). Analyses of the oxidation products have shown that in 1 M HClO₄ the main reaction is oxygen evolution, while in H₂SO₄ the main reaction is the formation of H₂S₂O₈. In both electrolytes small amounts of O₃ and H₂O₂ are formed. Finally, a simplified mechanism involving hydroxyl radicals formed by water discharge has been proposed for water oxidation on boron-doped diamond anodes.     

Enhanced image-based coordinate measurement using a super-resolution method

This paper proposed super-resolution measurement to improve the conventional image-based coordinate measurement system. An undesirable attribute showed by the conventional system is that increasing the accuracy of the system would compromise the field of view of the system. To improve this problem, image super-resolution techniques are proposed to preprocess the observed frames. A Lagrange–Newton method is derived specifically for automatic measurement consideration. Different a priori knowledge was also examined and it was identified that identity model is the most efficient a priori knowledge among the four a priori knowledge tested. Using the Lagrange–Newton method and identity model, an experiment is carried out to evaluate the proposed super-resolution measurement. The result showed that super-resolution measurement increases the accuracy of the system without compromising the field of view. Furthermore, it is also shown that super-resolution measurement can perform measurement on dimension not achievable using the conventional method.     

The Effect of Compatibilization of Maleated Polypropylene on a Blend of Polyamide-6 and Liquid Crystalline Copolyester

Blends of polyamide-6 (PA6) and thermotropic liquid crystalline polymer (LCP) compatibilized with various maleic-anhydride-grafted polypropylene (MAP) contents were injection-moulded. The effect of compatibilization on the mechanical properties of the blends was investigated by means of tensile testing, drop weight Charpy impact measurement and dynamic mechanical analysis. The static tensile measurement showed that the strain-at-break depends strongly on the MAP content. The impact test also indicated that the critical strain energy release rate (G_IC) is dependent on the MAP concentration. These results revealed that the 80%PA6/MAP(86/14)–20%LCP blend exhibits the highest strain-at-break and G_IC values. Moreover, the tensile ductility and impact toughness tended to decrease dramatically with increasing MAP content. This was attributed to the chemical and thermal decomposition of PA6 during blending for the LCP/PA6 blends containing higher MAP concentration. © of SCI.     

Carriage of bacteria by proboscises, legs, and feces of two species of flies in street food vending sites in Ouagadougou, Burkina Faso

Flies are widely recognized as potential reservoirs and vectors of bacteria. In the present study, an attempt was made to assess meat-poultry and local fruit juice processing and vending sites for their hygienic status and the presence of houseflies, Musca domestica, and blow flies, Lucilia caesar, for bacterial carriage. The hygienic status results revealed the presence of waste and sewage nearby which provided food and harborage for flies. On the two sites, the M. domestica population was dominant ranging from 76.48 to 91.30%, while the L. caesar population rate ranged from 8.70 to 23.52%. Using specific growth media for bacteria and biochemical tests, bacterial carriage of pooled fly proboscises, legs, and feces were assessed. For both flies, 66.67 to 100% of feces pools were positive for Shigella, Salmonella, and streptococci, while 35.41 to 82.05% of leg and proboscis pools were positive for the same bacteria. In assessment, 0 to 2.56% of feces pools and 8.33 to 28.20% of leg and proboscis pools were staphylococci positive. Coliforms were detected in 100% of pooled organs, while 10 x 10(3) to 1.1 x 10(3) CFU with predominance of coliforms, streptococci, and Shigella were counted on legs and feces of houseflies captured on the two vending sites. Blow flies from the same vending site had an organ bacterial load in the range of 3 x 10(2) to 2.7 x 10(3) CFU per organ. Coliforms, Shigella, and streptococci were present in high numbers. Staphylococci was noticed in low numbers in all parts tested of both flies. Captured housefly and blow fly bacteria-releasing frequency through feces was estimated at 5 to 35 CFU per feces sample for Salmonella and 85 to 495 CFU per feces sample for Shigella.     

Lipofundin Mediates the Major Inhibition of Intravenous Propofol in IL-1β Secretion and Phagocytosis of Staphylococcus aureus-Infected Macrophages

Lipofundin is the solvent for propofol in the intravenous injection of Propofol-Lipuro® and is used in patients who need intravenous feeding to provide fatty acids and fat for energy. In addition to propofol, Lipofundin also affects the immune modulation of phagocytes. In a previous study, we reported that intravenous propofol effectively decreased Staphylococcus aureus-stimulated reactive oxygen species (ROS) levels, IL-1β secretion, and phagocytosis in RAW264.7 macrophages. It is important to separately assess the effects of pure propofol, Lipofundin, and Propofol-Lipuro. By using an S. aureus-infected RAW264.7 macrophage model, the levels of secreted IL-1β in cell supernatants were determined by ELISA. IL-1β mRNA in cell pellets was further analyzed by quantitative polymerase chain reaction (qPCR), and Western blotting was performed to detect pro-IL-1β synthesis. Total ROS levels were determined by a luminol chemiluminescence assay. Compared with pure propofol, treatment with clinically relevant concentrations of Propofol-Lipuro and Lipofundin obviously reduced IL-1β secretion (>85% inhibition), S. aureus-stimulated ROS production (50% inhibition), and phagocytosis (>60% inhibition) to similar levels. Treatment with pure propofol alone significantly decreased IL-1β mRNA levels and pro-IL-1β protein synthesis, and slightly inhibited phagocytosis. In contrast, treatment with Propofol-Lipuro did not influence IL-1β mRNA or pro-IL-1β protein expression, even though treatment with Lipofundin increased the levels of both IL-1β mRNA and its precursor protein. In conclusion, IL-1β secretion is regulated at the posttranslational level. Lipofundin mediated the major effect of Propofol-Lipuro on the inhibition of IL-1β secretion, ROS production, and phagocytosis in S. aureus-infected RAW264.7 cells.     

Efficacy of a short 6 month therapeutic coursefor HIV infected tuberculosis patients in Abidjan, C?te d''Ivoire

From December 1992 to February 1993, 104 newly diagnosed pulmonary tuberculosis patients were enrolled in a prospective cohort study to assess the response to the 6 month-short-course regimen implemented in Cote d'Ivoire. This treatment encompassed the daily intake of Rifampicin and Pyrazinamide for 2 months followed by Rifampicin and Isoniazid for the remaining 4 months. All the patients were enrolled at the Treichville Tuberculosis Treatment Centre in Abidjan, and a follow-up of 6 months was observed for each patient. All in all, 41 patients were HIV-positive whereas 63 where HIV-negative. No statistical difference was noted between HIV-positive and HIV-negative patients with regard to the completion of therapy (85% versus 87%). The cure rate after an effective 6 month-therapy was similar among HIV-positive and HIV-negative patients (83% versus 84%) as well as the treatment failure rate which was 2.4% and 3% respectively. The results clearly indicate that the 6 month-short-course regimen policy implemented in C?te d'Ivoire is as effective for the treatment of HIV-associated tuberculosis as for the treatment of tuberculosis.     

Spark Plasma Sintered Hydroxyapatite/Graphite Nanosheet and Hydroxyapatite/Multiwalled Carbon Nanotube Composites: Mechanical and in Vitro Cellular Properties

Hyroxyapatite (HA) and its nanocomposites reinforced with 0.5, 1, 1.5, and 2 wt% graphite nanosheets (GNs) and multi‐walled carbon nanotubes (MWNTs) are fabricated by means of spark plasma sintering (SPS) process. The effects of MWNT and GN additions on the morphology, mechanical behavior, cell adhesion, and biocompatibility of HA were studied. Three‐point‐bending test shows that the bending strength of MWNT/HA nanocomposites increases with increasing MWNT content. However, the bending strength of GN/HA nanocomposites initially increases by adding 0.5 wt% GN, and then decreases markedly as the filler content increases. Cell culture and viability test results demonstrate that the GNs with diameters of several micrometers retard osteoblast cell adhesion and proliferation on the GN/HA nanocomposite. In contrast, the addition of 2 wt% MWNT to HA is beneficial to promote osteoblast adhesion and proliferation, thereby enhancing the biocompatibility of MWNT/HA nanocomposite.     

Epidemiology and features of knee osteoarthritis in the Ivory Coast

We retrospectively studied 369 cases of knee osteoarthritis in 240 patients seen at the Cocody Teaching Hospital in Abidjan, Ivory Coast, from November 1984 through March 1989. There were 126 cases (34.14%) of patellofemoral osteoarthritis, 104 cases (28.18%) of femorotibial osteoarthritis and 139 cases (37.66%) of global knee osteoarthritis (defined as patellofemoral and femorotibial osteoarthritis in the same joint). There was a marked female bias (80.42% of patients). Onset was earlier in patellofemoral osteoarthritis (51.25 years) than in femorotibial osteoarthritis (57.85 years). Half the patients (51.25%) were housewives. The Akan and Mandé ethnic groups contributed 61.54% and 33.03% of patients, respectively. Obesity was present in 19.04% of cases of patellofemoral osteoarthritis and in 10.57% of cases of femorotibial osteoarthritis. Of the patients with femorotibial osteoarthritis, 20.20% had a history of arthritis of the knee and of those with global knee osteoarthritis, 12.23% reported a prior injury to the knee. Varus deformity was found in 24.03% and valgus deformity in 19.23% of the patients with femorotibial osteoarthritis.     

GaAs/AlGaAs nanowire heterostructures studied by scanning tunneling microscopy

We directly image the interior of GaAs/AlGaAs axial and radial nanowire heterostructures with atomic-scale resolution using scanning tunneling microscopy. We show that formation of monolayer sharp and smooth axial interfaces are possible even by vapor-phase epitaxy. However, we also find that instability of the ternary alloys formed in the Au seed fundamentally limits axial heterostructure control, inducing large segment asymmetries. We study radial core-shell nanowires, imaging even ultrathin submonolayer shells. We demonstrate how large twinning-induced morphological defects at the wire surfaces can be removed, ensuring the formation of wires with atomically flat sides.     

Physicochemical Properties of Calcium Caseinate Films Cross-Linked by Gamma-Irradiation

Gamma-irradiation was used to produce freestanding, sterilized, cross-linked caseinate films and gels. Mechanical properties of gels and films and water vapor permeability of dried films were determined. Irradiated films were significantly ( p ≤0.05) more resistant to puncture and moisture. Also, gels were formed when protein solutions received radiation doses ≥16 kGy. The addition of CaCl 2 in the solution containing proteins, glycerol, and carboxymethylcellulose (base formulation) increased significantly the puncture strength for the films atirradiation doses ≥16 kGy. Sorbitol had the greatest plasticizing effect andsignificantly ( p ≤0.05) increased distance to puncture, while mannitoldecreased distance to puncture. Size-exclusion chromatography performed on the irradiated solutions of the base formulation showed that gamma-irradiation increased the molecular weight of calcium caseinate by 100 times; the molecular weight was ≥2×10 3 kDa. Films produced with base formulation were alsoimmersed in flasks containing 100mL of boiling water during 30 min forinsolubility measurements. Results showed that the proportion of the insolublefraction increased with the irradiationdose. Seventy percent of the irradiated films (32 kGy) remained insoluble after immersion in water at 100°C, 30 min and 20°C, 24 h. Water vapor permeability (WVP) of the base formulation films was reduced from 3.99±0.23 to 2.57±0.63 g.mm/m 2 .d.mmHg after irradiationtreatment. Microbial resistance of cross-linked films (base formulation)showed that 36% of N from calcium caseinate films was converted to soluble N after 60 d in presence of Pseudomonas aeruginosa .