Search results for " Structures"

Vitrectomía enzimática por inyección intravítrea de plasmina autóloga como tratamiento inicial del edema macular diabético difuso

2008

espanolObjetivo: Determinar si la inyeccion intravitrea de plasmina es efectiva en el tratamiento del edema macular diabetico difuso (EMDD). Diseno: Estudio piloto prospectivo, comparativo, de intervencion, serie de casos. Pacientes: Dieciocho pacientes con edema macular diabetico bilateral, recibieron como primera actuacion terapeutica una inyeccion intravitrea de plasmina en un ojo, sirviendo el ojo contralateral como control. Tratamiento: Inyeccion intravitrea de 0,2 ml de plasmina autologa bajo anestesia topica. La plasmina fue obtenida por un metodo simplificado. Principales medidas: Engrosamiento macular central (EMC) medido por tomografia de coherencia optica (OCT) y agudeza visual (…

Nested allosteric interactions in extracellular hemoglobin of the leech Macrobdella decora

2003

Hemoglobin from the leech Macrobdella decora belongs to the class of giant extracellular hexagonal bilayer globin structures found in annelid and vestimentiferan worms. These complexes consist of 144 heme-bearing subunits, exhibit a characteristic quaternary structure (2 × (6 × (3 × 4))), and contain tetramers as basic substructures that express cooperative oxygen binding and thus provide a structural basis for a hierarchy in allosteric interactions. A thorough analysis of the isolated tetramer indicates that it functions as a trimer of cooperatively interacting subunits and a non-cooperative monomer rather than as four interacting subunits. A thermodynamic analysis of the whole molecule fa…

2017

In continuous flash suppression (CFS), a dynamic noise masker, presented to one eye, suppresses conscious perception of a test stimulus, presented to the other eye, until the suppressed stimulus comes to awareness after few seconds. But what do we see breaking the dominance of the masker in the transition period? We addressed this question with a dual-task in which observers indicated (i) whether the test object was left or right of the fixation mark (localization) and (ii) whether it was a face or a house (categorization). As done recently (Stein et al., 2011), we used two experimental varieties to rule out confounds with decisional strategy. In the terminated mode, stimulus and masker wer…

Biocompatibility and biodistribution of functionalized carbon nano-onions (f-CNOs) in a vertebrate model

2016

AbstractFunctionalized carbon nano-onions (f-CNOs) are of great interest as platforms for imaging, diagnostic and therapeutic applications due to their high cellular uptake and low cytotoxicity. To date, the toxicological effects of f-CNOs on vertebrates have not been reported. In this study, the possible biological impact of f-CNOs on zebrafish during development is investigated, evaluating different toxicity end-points such as the survival rate, hatching rate, and heart beat rate. Furthermore, a bio-distribution study of boron dipyrromethene (BODIPY) functionalized CNOs in zebrafish larvae is performed by utilizing inverted selective plane illumination microscopy (iSPIM), due to its intri…

Molecular Cloning, Heterologous Expression, and Characterization of Ornithine Decarboxylase from Oenococcus oeni

2011

International audience; Ornithine decarboxylase (ODC) is responsible for the production of putrescine, the major biogenic amine found in wine. Oenococcus oeni is the most important lactic acid bacterium in the winemaking process and is involved in malolactic fermentation. We report here the characterization of ODC from an O. oeni strain isolated from wine. Screening of 263 strains isolated from wine and cider from all over the world revealed that the presence of the odc gene appears to be strain specific in O. oeni. After cloning, heterologous expression in Escherichia coli, and characterization, the enzyme was found to have a molecular mass of 85 kDa and a pI of 6.2 and revealed maximal ac…

Geographical variation in egg size of the Great Tit Parus major: a new perspective.

2002

A recent study on geographical variation in egg size of Great Tits Parus major concluded that: (1) mean egg size tended to increase with increasing latitude; and (2) mean egg size was positively correlated with mean clutch size. Including new data on both egg and clutch size, we reanalysed the relationships between egg size, clutch size and latitude, and investigated the possible effects of habitat type, female body size and egg shape on these relationships. We found that (1) egg volume showed minimum values around 51°N, increasing both north and southwards; (2) female body size increased linearly with increasing latitude; (3) female body size was positively correlated with egg breadth, but…

Regulatory factor for the transcription of the ribosomal genes in amphibian oocytes.

1970

AMPHIBIAN oocytes provide very convenient material for the study of the mechanisms that control ribosomal RNA synthesis because their pattern of ribosomal RNA synthesis does not change greatly during oogenesis. During the lampbrush stage of oogenesis (stage 4) more than 97 per cent of the RNA synthesized per unit time in the oocytes is ribosomal. This happens because the genes for ribosomal RNA are specifically amplified3–5 to such an extent that the oocyte nucleus (germinal vesicle) has an rDNA content approximately 1,500 times more than the haploid amount4. On the other hand, in mature oocytes (stage 6) no ribosomal RNA is synthesized1,2, although the extra copies of the ribosomal cistron…

Titanium Lattice Structures Produced via Additive Manufacturing for a Bone Scaffold: A Review

2023

The progress in additive manufacturing has remarkably increased the application of lattice materials in the biomedical field for the fabrication of scaffolds used as bone substitutes. Ti6Al4V alloy is widely adopted for bone implant application as it combines both biological and mechanical properties. Recent breakthroughs in biomaterials and tissue engineering have allowed the regeneration of massive bone defects, which require external intervention to be bridged. However, the repair of such critical bone defects remains a challenge. The present review collected the most significant findings in the literature of the last ten years on Ti6Al4V porous scaffolds to provide a comprehensive summa…

Ocular biometry with swept-source optical coherence tomography

2020

This study aimed to summarize the outcomes reported when swept-source optical coherence tomography (SS-OCT) is used for ocular biometry. A literature search was performed to identify publications reporting clinical outcomes of patients measured with commercial SS-OCT. Twenty-nine studies were included in this review. A comprehensive analysis of the available data was performed, focusing on parameters used for intraocular lens (IOL) power calculation in cataract surgery, including keratometry, central corneal thickness, white-to-white distance, anterior chamber depth, lens thickness, axial length, IOL power, and pupil diameter. Different metrics for repeatability, reproducibility, and agreem…

Evaluation of 6 biometers based on different optical technologies

2021

This study shows that optical biometers based on different technologies provide repeatable measurements for different ocular parameters and, when compared, statistically significant differences between them were found when measuring most parameters.