Biological synthesis of fluorescent nanoparticles by cadmium and tellurite resistant Antarctic bacteria: exploring novel natural nanofactories

Indexación: Web of ScienceBackground: Fluorescent nanoparticles or quantum dots (QDs) have been intensely studied for basic and applied research due to their unique size-dependent properties. There is an increasing interest in developing ecofriendly methods to synthesize these nanoparticles since they improve biocompatibility and avoid the generation of toxic byproducts. The use of biological systems, particularly prokaryotes, has emerged as a promising alternative. Recent studies indicate that QDs biosynthesis is related to factors such as cellular redox status and antioxidant defenses. Based on this, the mixture of extreme conditions of Antarctica would allow the development of natural QDs producing bacteria. Results: In this study we isolated and characterized cadmium and tellurite resistant Antarctic bacteria capable of synthesizing CdS and CdTe QDs when exposed to these oxidizing heavy metals. A time dependent change in fluorescence emission color, moving from green to red, was determined on bacterial cells exposed to metals. Biosynthesis was observed in cells grown at different temperatures and high metal concentrations. Electron microscopy analysis of treated cells revealed nanometric electron-dense elements and structures resembling membrane vesicles mostly associated to periplasmic space. Purified biosynthesized QDs displayed broad absorption and emission spectra characteristic of biogenic Cd nanoparticles. Conclusions: Our work presents a novel and simple biological approach to produce QDs at room temperature by using heavy metal resistant Antarctic bacteria, highlighting the unique properties of these microorganisms as potent natural producers of nano-scale materials and promising candidates for bioremediation purposes.http://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-016-0477-

Assessment of left ventricle dynamic from cardiac magnetic resonance imaging by means a correspondence approach

In this research, an approach to assess the heart dynamics is reported. The cardiac magnetic resonance images are considered for assessing the left ventricle motion and deformation. The shape of the cavity is obtained by means a segmentation procedure based on a clustering algorithm at an initial instant. This three-dimensional structure is used to establish a region of interest around the border of the structure. An optical flow method allows determining the displacement vector of this region and then defining the shapes of the cavity during the all cardiac cycle. The points of the left ventricle are followed using the displacement vectors in the cardiac cycle, obtaining thus, a dense motion field of the cavity. This approximate deformation field is refined with a correspondence method that working in the three-dimensional space. The mapping of the points that define the left ventricle in the cardiac cycle obtained with the correspondence procedure are then used for computing a set of clinical parameters that allows assessing the motion and deformation of this principal structure of the human heart. The torsion, radial and longitudinal contraction are quantified. The obtained results are promising for evaluating the heart dynamics

Uncertainty as key element in the analysis of X–ray angiography images

The X–ray angiography images are routinely used to assess the blood vessels. The acquisition procedure considers a medical imaging system which allows obtaining views of the vessel while the blood flows thought them. The X–ray source is influenced on the region to be viewed and then, the projection of the all anatomical structures in the champ of view is shown through an image intensifier. The information of the blood vessel is impacted for the other structures. Additionally, the blood and the contrast product required in the acquisition are not mixed homogeneously, producing artifacts in the images. Finally, the noise is also an impact factor in the quality of the angiography images. In the coronary vessel case, the branches of the network are superposed. In this paper, an enhancement procedure to diminish the uncertainty associated to X–ray angiography images is reported. The relation between two versions of the angiograms is determined using a fuzzy connector considering that this relation diminishes the images intrinsic uncertainty. These versions correspond with images filtered with low-pass and high-pass image filters, respectively. The technique is tested with images of the coronary and kidney vessels. The qualitative results show a good enhanced of the angiography images

O PROCESSO DE INCLUSÃO ESCOLAR DE UMA CRIANÇA COM SÍNDROME DE NOONAN: UM ESTUDO DE CASO

O objetivo central desta dissertação é entender como tem se dado o processo de inclusão de um aluno com deficiência intelectual, causada pela síndrome de Noonan, no contexto da escola comum. Em relação ao desenvolvimento desta pesquisa optei por assumir como aporte os pressupostos teórico-filosóficos da abordagem sócio-histórica, com base nas contribuições teóricas de Vigotski. Com a finalidade de alcançar esse objetivo utilizei como metodologia o estudo de caso do tipo etnográfico e para obter os dados utilizei como ferramentas a observação participante, o diário de campo e as entrevistas semiestruturadas. Foram nos momentos de investigação que surgiram as análises de dados, evidenciando que a aprendizagem do aluno com deficiência intelectual não se diferencia dos demais alunos, porém necessita de outras vias para se realizar, cabendo à interação o papel de renovar, compartilhar e ressignificar conhecimentos no ambiente escolar. Considerando o objetivo central pude entender que o processo de inclusão do aluno com deficiência intelectual surge do resultado da combinação da história do indivíduo com o meio social. Nesse contexto, os dados obtidos revelam que é no cotidiano escolar que se manifestam as diferenças, realidade na qual poderia haver ações curriculares para um currículo flexível adaptado às necessidades dos alunos com e sem deficiência, em uma prática pedagógica estimulante e atrativa conforme as particularidades de cada criança. Por fim, é importante ressaltar que a apropriação do conhecimento pelo aluno, independentemente de suas condições orgânicas, é possível desde que o sujeito seja vislumbrado como um ser social e cultural e não apenas um ser biológico

Social Perception of the Residents of Olón, Montañita, and Valdivia as a Conditioning Factor in the Satisfaction of Tourists

This research aims to understand the social perception of the communities of Olón, Montañita, and Valdivia in the sociocultural, socio-territorial, and socio-cognitive dimensions, as a determining factor in the satisfaction of national and foreign tourists in terms of destination, service, and infrastructure. The design is nonexperimental, with a correlational scope and a mixed approach. Data collection techniques used were a semi-structured interview with 24 residents and a survey of 396 residents and 396 tourists. STATIS Dual and MPLS (multiway partial least squares) were the software used for the treatment of quantitative information. It was determined that the social perception in the three communes was relatively similar, the sociocultural dimension being the best scored for being linked to the tourist development of Olón and Montañita. Whereas a significant difference was observed between the communes in terms of tourist satisfaction, placing Montañita as the leader in all dimensions of the variable, followed by Olón and Valdivia. With an adjustment of 69%, the MPLS model was directly related to the variables, implying that any change in the perception of the residents affects the satisfaction of tourists. Keywords: tourist satisfaction, social perception, spondylus route. Resumen El objetivo de esta investigación es conocer la percepción social de las comunidades de Olón, Montañita y Valdivia en las dimensiones socio cultural, socio territorial y socio cognitivo, como condicionante en la satisfacción de los turistas nacionales y extranjeros en cuanto al destino, servicio e infraestructura. El diseño es no experimental, de alcance correlacional y enfoque mixto; como técnicas de recolección de datos se utilizaron: entrevista semi estructurada a 24 residentes y, encuesta a 396 residentes y 396 turistas. Para el tratamiento de la información cuantitativa se utilizaron software STATIS Dual y MPLS (Multiway partial least squares). Se determinó que la percepción social en las tres comunas es relativamente similar, siendo la dimensión socio cultural la mejor puntuada por encontrarse ligada al desarrollo turístico de Olón y Montañita; mientras que, existe diferencia significativa entre las comunas en cuanto a satisfacción de los turistas, colocando a Montañita como líder en todas las dimensiones de la variable, seguida de Olón y Valdivia. Con un ajuste de 69%, el modelo MPLS relacionó directamente las variables, implicando que cualquier cambio en la percepción de los residentes incide sobre la satisfacción de los turistas. Palabras Clave: satisfacción del turista, percepción social, ruta spondylus

Magnesium(II)-ATP Complexes in 1-Ethyl-3-Methylimidazolium Acetate Solutions Characterized by 31Mg β-Radiation-Detected NMR Spectroscopy

The complexation of MgII with adenosine 5′-triphosphate (ATP) is omnipresent in biochemical energy conversion, but is difficult to interrogate directly. Here we use the spin-urn:x-wiley:14337851:media:anie202207137:anie202207137-math-0001 β-emitter 31Mg to study MgII-ATP complexation in 1-ethyl-3-methylimidazolium acetate (EMIM-Ac) solutions using β-radiation-detected nuclear magnetic resonance (β-NMR). We demonstrate that (nuclear) spin-polarized 31Mg, following ion-implantation from an accelerator beamline into EMIM-Ac, binds to ATP within its radioactive lifetime before depolarizing. The evolution of the spectra with solute concentration indicates that the implanted 31Mg initially bind to the solvent acetate anions, whereafter they undergo dynamic exchange and form either a mono- (31Mg-ATP) or di-nuclear (31MgMg-ATP) complex. The chemical shift of 31Mg-ATP is observed up-field of 31MgMg-ATP, in accord with quantum chemical calculations. These observations constitute a crucial advance towards using β-NMR to probe chemistry and biochemistry in solution

Phase I dose-escalation study of the mTOR inhibitor sirolimus and the HDAC inhibitor vorinostat in patients with advanced malignancy.

Preclinical models suggest that histone deacetylase (HDAC) and mammalian target of rapamycin (mTOR) inhibitors have synergistic anticancer activity. We designed a phase I study to determine the safety, maximum tolerated dose (MTD), recommended phase II dose (RP2D), and dose-limiting toxicities (DLTs) of combined mTOR inhibitor sirolimus (1 mg-5 mg PO daily) and HDAC inhibitor vorinostat (100 mg-400 mg PO daily) in patients with advanced cancer. Seventy patients were enrolled and 46 (66%) were evaluable for DLT assessment since they completed cycle 1 without dose modification unless they had DLT. DLTs comprised grade 4 thrombocytopenia (n = 6) and grade 3 mucositis (n = 1). Sirolimus 4 mg and vorinostat 300 mg was declared RP2D because MTD with sirolimus 5 mg caused significant thrombocytopenia. The grade 3 and 4 drug-related toxic effects (including DLTs) were thrombocytopenia (31%), neutropenia (8%), anemia (7%), fatigue (3%), mucositis (1%), diarrhea (1%), and hyperglycemia (1%). Of the 70 patients, 35 (50%) required dose interruption or modification and 61 were evaluable for response. Partial responses were observed in refractory Hodgkin lymphoma (-78%) and perivascular epithelioid tumor (-54%), and stable disease in hepatocellular carcinoma and fibromyxoid sarcoma. In conclusion, the combination of sirolimus and vorinostat was feasible, with thrombocytopenia as the main DLT. Preliminary anticancer activity was observed in patients with refractory Hodgkin lymphoma, perivascular epithelioid tumor, and hepatocellular carcinoma