Electrochemical nanoarchitectonics through polyaminobenzylamine-dodecyl phosphate complexes: Redox activity and mesoscopic organization in self-assembled nanofilms

Molecular design and preparation of redox active films displaying mesoscopic levels of organization represents one of the most actively pursued research areas in nanochemistry. These mesostructured materials are not only of great interest at the fundamental level because of their unique properties but they can also be employed for a wide range of applications such as electrocatalysts, electronic devices, and electrochemical energy conversion and storage. Herein, we introduce a simple and straightforward strategy to chemically modify electrode surfaces with self-assembled electroactive polyelectrolyte-surfactant complexes. These assemblies are composed of amino-appended polyaniline and monododecyl phosphate. The complexes were deposited by spin-coating and the films were characterized by spectroscopic and X-ray-based techniques: XRR, GISAXS, WAXS, and XPS. The films presented a well-defined lamellar structure, directed by the strong interaction between the phosphate groups and the positively charged amine groups in the polyelectrolyte. These films also displayed intrinsic electroactivity in both acidic and neutral solutions, showing that the polymer remains electroactive and ionic transport is still possible through the stratified and hydrophobic coatings. The stability and enhanced electroactivity in neutral solutions make these assembled films promising building blocks for the construction of nanostructured electrochemical platforms.Fil: Lorenzo, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Marmisollé, Waldemar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Ceolin, Marcelo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Containment of a genetically modified microorganism by an activated sludge system

Abstract The effectiveness of physical, chemical and biological barriers to the diffusion of genetically modified microorganisms (GMMs) to prevent their release into the environment is currently under scrutiny worldwide because of the associated potential ecological impacts. An industrial discharge of a non-sterilized fermentation broth containing GMM biomass into a conventional municipal wastewater treatment plant would deliver the GMMs into the activated sludge system process (ASSP). The present work aimed to model and evaluate the containment capability of a small ASSP (part of a 20,000 people equivalent municipal plant) in the event of receiving GMM biomass from a medium-small biotechnological plant dedicated to the production of polyhydroxyalkanoates (3000 t/year of biopolymer). An actual GMM (Pseudomonas putida KTOY06) was injected into a bench-scale ASSP (ASSPLab) in a quantity proportional to the relative dimensions of the plants mentioned. The experimental and model results indicated that the ASSP of the target municipal treatment plant would not be capable of holding back such a sudden input of GMM; 6 h after the discharge, 11–15 % of injected GMM cells were released through the clarified stream of the ASSPLab, with the rest being gradually released over time. Since the GMM employed did not exhibit any growth in the ASSPLab, its concentration in the clarified water stream would not represent a substantial risk of release into the environment if appropriate tertiary treatments were integrated. This study confirmed the necessity of a thorough risk assessment of biotechnological processes prior to their implementation

Highly-organized stacked multilayers: Via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Stratified supramolecular structures for (bio)electrochemical nanoarchitectonics

Supramolecular self-assembly is of paramount importance for the development of novel functional materials with molecular-level feature control. In particular, the interest in creating well-defined stratified multilayers through simple methods using readily available building blocks is motivated by a multitude of research activities in the field of "nanoarchitectonics" as well as evolving technological applications. Herein, we report on the facile preparation and application of highly organized stacked multilayers via layer-by-layer assembly of lipid-like surfactants and polyelectrolytes. Polyelectrolyte multilayers with high degree of stratification of the internal structure were constructed through consecutive assembly of polyallylamine and dodecyl phosphate, a lipid-like surfactant that act as a structure-directing agent. We show that multilayers form well-defined lamellar hydrophilic/hydrophobic domains oriented parallel to the substrate. More important, X-ray reflectivity characterization conclusively revealed the presence of Bragg peaks up to fourth order, evidencing the highly stratified structure of the multilayer. Additionally, hydrophobic lamellar domains were used as hosts for ferrocene in order to create an electrochemically active film displaying spatially-addressed redox units. Stacked multilayers were then assembled integrating redox-tagged polyallylamine and glucose oxidase into the stratified hydrophilic domains. Bioelectrocatalysis and "redox wiring" in the presence of glucose was demonstrated to occur inside the stratified multilayer.Fil: Cortez, María Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Lorenzo, Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Marmisollé, Waldemar Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Von Bilderling, Catalina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Maza, Eliana María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Pietrasanta, Lia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; ArgentinaFil: Battaglini, Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ceolin, Marcelo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Azzaroni, Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Influence of the Interposition of a Nonhollow Probe during Cannula Extraction on Sclerotomy Vitreous Incarceration in Sutureless Vitrectomy

PURPOSE. To evaluate the effect of the cannula removal technique on postoperative vitreous incarceration using an experimental model of vitrectomized eye. METHODS. In a prospective, experimental, randomized, and observer-masked study, 118 cadaveric pig eyes were vitrectomized through 23-gauge transconjunctival sclerotomies. Once vitrectomy was finished, one of the superior cannulas was extracted with the illumination probe inserted through it, and the other cannula was removed with a cannula plug inserted. Postoperative incisional vitreous entrapment was evaluated by direct visualization. No vitreous incarceration was classified as grade 0 (G0), thin vitreous entrapment was classified as grade 1 (G1), and thick vitreous strands as grade 2 (G2). RESULTS. Considering the sclerotomies whose cannulas were extracted with the light probe inside, vitreous incarceration was detected in 93.2% (73.7% G1, 19.5% G2) of the incisions. In turn, vitreous entrapment was observed in 95.8% (43.2% G1, 52.6% G2) of the entry sites whose cannulas were extracted with the plug inserted. Statistical analysis showed significant differences when comparing postvitrectomy vitreous incarceration grades in sclerotomies according to the cannula extraction technique (P < 0.0001). CONCLUSIONS. Interposing the light probe through the cannula during its removal reduces vitreous incarceration grade in our experimental model. This simple maneuver may decrease complications related to vitreous entrapment, such as peripheral retinal tears and acute endophthalmitis. (Invest Ophthalmol Vis Sci. 2012;53:7322-7326

Canine Filamentous Dermatitis Associated with Borrelia Infection

Background: Although canine clinical manifestations of Lyme disease vary widely, cutaneous manifestations are not well documented in dogs. In contrast, a variety of cutaneous manifestations are reported in human Lyme disease caused by the spirochete Borrelia burgdorferi. A recently recognized dermopathy associated with tickborne illness known as Morgellons disease is characterized by brightly-colored filamentous inclusions and projections detected in ulcerative lesions and under unbroken skin. Recent studies have demonstrated that the dermal filaments are collagen and keratin biofibers produced by epithelial cells in response to spirochetal infection. We now describe a similar filamentous dermatitis in canine Lyme disease. Methods and Results: Nine dogs were found to have cutaneous ulcerative lesions containing embedded or projecting dermal filaments. Spirochetes characterized as Borrelia spp. were detected in skin tissue by culture, histology, immunohistochemistry, polymerase chain reaction (PCR) and gene sequencing performed at five independent laboratories. Borrelia DNA was detected either directly from skin specimens or from cultures inoculated with skin specimens taken from the nine canine study subjects. Amplicon sequences from two canine samples matched gene sequences for Borrelia burgdorferi sensu stricto. PCR amplification failed to detect spirochetes in dermatological specimens from four healthy asymptomatic dogs. Conclusions: Our study provides evidence that a filamentous dermatitis analogous to Morgellons disease may be a manifestation of Lyme disease in domestic dogs

Haemoglobin levels for population from Gambo, a rural area of Ethiopia, and their association with anaemia and malaria

BACKGROUND: Knowledge of appropriate reference intervals is critical not only to provide optimal clinical care, but also to enrol populations in medical research. The aim of this study was to generate normal ranges of laboratory values for haemoglobin among healthy Ethiopian adults and children and to determine if anaemia is a possible indicator of malaria in women and children in this area of Ethiopia. METHODS: This study was carried out from January 2008 to May 2010. The reference sample population with malaria-negative consisted of 454 individuals, divided women, men and children. The malaria-infected sample population consisted of 117 individuals. The reference ranges were based on the guidelines from the Clinical and Laboratory Standards Institute. Haemoglobin concentration was determined by Hemo-Control EKF Diagnostic Analyser on whole blood. Testing for malaria-positive and negative infection was done by microscopy and by PCR. RESULTS: The lower limits for adult haemoglobin range obtained from this population were slightly higher than those derived from other African populations, but were equal to those established by other studies in Ethiopia and the World Health Organization (WHO). Regarding children, the minimum values were lower than those obtained from different African populations and those established by WHO. The malaria-negative group had anaemia in 35.6% of cases and in the malaria-positive group in 70.9%. There was a stronger, statistically significant association between anaemia and malaria-positive samples than between anaemia and malaria-negative samples in women and both groups of children. CONCLUSIONS: The results from this study are a contribution in the definition of the haemoglobin parameters in African populations, which could be taken as standards for interpretation of laboratory results. The haemoglobin indices in adults from Gambo tended to be higher than other African populations and in children were lower than other studies in Africa. The results also suggest that anaemia is not useful as a supportive diagnostic criterion to monitor and evaluate malaria in women and children from Ethiopia, because a 29.1% of malaria cases will be not detected, because of not having anaemia

A 2200-year record of Andean Condor diet and nest site usage reflects natural and anthropogenic stressors

Understanding how animals respond to large-scale environmental changes is difficult to achieve because monitoring data are rarely available for more than the past few decades, if at all. Here, we demonstrate how a variety of palaeoecological proxies (e.g. isotopes, geochemistry and DNA) from an Andean Condor (Vultur gryphus) guano deposit from Argentina can be used to explore breeding site fidelity and the impacts of environmental changes on avian behaviour. We found that condors used the nesting site since at least approximately 2200 years ago, with an approximately 1000-year nesting frequency slowdown from ca 1650 to 650 years before the present (yr BP). We provide evidence that the nesting slowdown coincided with a period of increased volcanic activity in the nearby Southern Volcanic Zone, which resulted in decreased availability of carrion and deterred scavenging birds. After returning to the nest site ca 650 yr BP, condor diet shifted from the carrion of native species and beached marine animals to the carrion of livestock (e.g. sheep and cattle) and exotic herbivores (e.g. red deer and European hare) introduced by European settlers. Currently, Andean Condors have elevated lead concentrations in their guano compared to the past, which is associated with human persecution linked to the shift in diet.Fil: Duda, Matthew P.. Queen's University; CanadáFil: Grooms, Christopher. Queen's University; CanadáFil: Sympson, Lorenzo. Sociedad Naturalista Andino Patagonica; ArgentinaFil: Blais, Jules M.. University of Ottawa; CanadáFil: Dagodzo, Daniel. University of Ottawa; CanadáFil: Feng, Wenxi. Queen's University; CanadáFil: Hayward, Kristen M.. Queen's University; CanadáFil: Julius, Matthew L.. St. Cloud State University; Estados UnidosFil: Kimpe, Linda E.. University of Ottawa; CanadáFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Layton Matthews, Daniel. Queen's University; CanadáFil: Lougheed, Stephen. Queen's University; CanadáFil: Massaferro, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Michelutti, Neal. Queen's University; CanadáFil: Pufahl, Peir K.. Queen's University; CanadáFil: Vuletich, April. Queen's University; CanadáFil: Smol, John P.. Queen's University; Canad