1,254 research outputs found
Phenotypic Features and Genetic Findings in a Cohort of Italian Pseudoxanthoma Elasticum Patients and Update of the Ophthalmologic Evaluation Score
Background: Pseudoxanthoma elasticum (PXE) is a rare ectopic calcification genetic disease mainly caused by ABCC6 rare sequence variants. The clinical phenotype is characterized by typical dermatological, ophthalmological and cardiovascular manifestations, whose frequency and severity are differently reported in the literature. Methods: A retrospective study was performed on 377 PXE patients of Italian origin, clinically evaluated according to the Phenodex Index, who underwent ABCC6 biomolecular analyses. Moreover, 53 PXE patients were further characterized by in-depth ophthalmological examinations. Results: A total of 117 different ABCC6 rare sequence variants were detected as being spread through the whole gene. The severity of the clinical phenotype was dependent on age, but it was not influenced by gender or by the type of sequence variants. In-depth ophthalmological examinations focused on the incidences of coquille d'oeuf, comet lesions, pattern dystrophy-like lesions, optic disk drusen and posterior-pole atrophy. Conclusion: Given the large number of patients analyzed, we were able to better evaluate the occurrence of less frequent alterations (e.g., stroke, myocardial infarction, nephrolithiasis). A more detailed description of ophthalmological abnormalities allowed us to stratify patients and better evaluate disease progression, thus suggesting a further update of the PXE score system
Fatigue analysis-based numerical design of stamping tools made of cast iron
This work concerns stress and fatigue analysis of stamping tools made of cast iron with an essentially pearlitic matrix and containing foundry defects. Our approach consists at first, in coupling the stamping numerical processing simulations and structure analysis in order to improve the tool stiffness geometry for minimizing the stress state and optimizing their fatigue lifetime. The method consists in simulating the stamping process by considering the tool as a perfect rigid body. The estimated contact pressure is then used as boundary condition for FEM structure loading analysis of the tool. The result of this analysis is compared with the critical stress limit depending on the automotive model. The acceptance of this test allows calculating the fatigue lifetime of the critical zone by using the S–N curve of corresponding load ratio. If the prescribed tool life requirements are not satisfied, then the critical region of the tool is redesigned and the whole simulation procedures are reactivated. This method is applied for a cast iron EN-GJS-600-3. The stress-failure (S–N) curves for this material is determined at room temperature under push pull loading with different load ratios R0σmin/σmax0−2, R0−1 and R00.1. The effects of the foundry defects are determined by SEM observations of crack initiation sites. Their presence in tested specimens is associated with a reduction of fatigue lifetime by a factor of 2. However, the effect of the load ratio is more important
High-yield production of nano-lateral size graphene oxide by high-power ultrasonication
Nanographene oxide (GOn) constitutes a nanomaterial of high value in the biomedical field. However, large scale production of highly stable aqueous dispersions of GOn is yet to be achieved. In this work, we explored high-power ultrasonication as a method to reduce particle size of GO and characterized the impact of the process on the physicochemical properties of the material. GOn was obtained with lateral dimensions of 99 ± 43 nm and surface charge of -39.9 ± 2.2 mV. High-power ultrasonication enabled an improvement of stability features, particularly by resulting in a decrease of the average particle size, as well as zeta potential, in comparison to GO obtained by low-power exfoliation and centrifugation (287 ± 139 nm; -29.7 ± 1.2 mV). Remarkably, GOn aqueous dispersions were stable for up to 6 months of shelf-time, with a global process yield of 74%. This novel method enabled the production of large volumes of highly concentrated (7.5 mg mL-1) GOn aqueous dispersions. Chemical characterization of GOn allowed the identification of characteristic oxygen functional groups, supporting high-power ultrasonication as a fast, efficient, and productive process for reducing GO lateral size, while maintaining the material’s chemical features.This work was financed by FEDER funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by national funds (PIDDAC) through FCT/MCTES in the framework of the project POCI-01-0145-FEDER-031143, and Base Funding—UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology and Energy—LEPABE. Authors would also like to thank the support of i3S Scientific Platforms and respective funding: HEMS, member of the national infrastructure PPBI—Portuguese Platform of Bioimaging: POCI-01-0145-FEDER-022122; and Biointerfaces and Nanotechnology (BN) Laboratory, Portuguese Funds through FCT, UID/BIM/04293/2019. Artur Pinto thanks the Portuguese Foundation for Science and Technology (FCT) for the financial support of his work contract through the Scientific Employment Stimulus—Individual Call—[CEECIND/03908/2017]
PHP12 Pesquisa Nacional de Acesso a Medicamentos no Brasil - Percepção dos Usuários da Atenção Básica do Sistema Único de Saúde
Graphene oxide topical administration: Skin permeability studies
Nanostructured carriers have been widely used in pharmaceutical formulations for der-matological treatment. They offer targeted drug delivery, sustained release, improved biostability, and low toxicity, usually presenting advantages over conventional formulations. Due to its large surface area, small size and photothermal properties, graphene oxide (GO) has the potential to be used for such applications. Nanographene oxide (GOn) presented average sizes of 197.6 ± 11.8 nm, and a surface charge of -39.4 ± 1.8 mV, being stable in water for over 6 months. 55.5% of the mass of GOn dispersion (at a concentration of 1000 µg mL-1 ) permeated the skin after 6 h of exposure. GOn dispersions have been shown to absorb near-infrared radiation, reaching temperatures up to 45.7¿ C, within mild the photothermal therapy temperature range. Furthermore, GOn in amounts superior to those which could permeate the skin were shown not to affect human skin fibroblasts (HFF-1) morphology or viability, after 24 h of incubation. Due to its large size, no skin permeation was observed for graphite particles in aqueous dispersions stabilized with Pluronic P-123 (Gt–P-123). Altogether, for the first time, Gon’s potential as a topic administration agent and for delivery of photothermal therapy has been demonstrated.This work was financed by FEDER funds through the COMPETE 2020–Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by national funds (PIDDAC) through FCT/MCTES in the framework of the project POCI-01-0145-FEDER-031143, and Base Funding-UIDB/00511/2020 of the Laboratory for Process Engineering, Environment, Biotechnology and Energy–LEPABE. Additional funding included FCT/MCTES in the framework of the project “Institute for Research and Innovation in Health Sciences” (UID/BIM/04293/2019). Authors would also like to thank the support of i3S Scientific Platforms and respective funding: HEMS, member of the national infrastructure PPBI–Portuguese Platform of Bioimaging: POCI-01-0145-FEDER-022122; and Biointerfaces and Nanotechnology (BN) Laboratory, Portuguese Funds through FCT, UID/BIM/04293/2019. Artur Pinto thanks the Portuguese Foundation for Science and Technology (FCT) for the financial support of his work contract through the Scientific Employment Stimulus-Individual Call–[CEECIND/03908/2017]. Soraia Pinto (SFRH/BD/144719/2019) would like to thank FCT, Portugal for financial support
On the leading OPE corrections to the ghost-gluon vertex and the Taylor theorem
This brief note is devoted to a study of genuine non-perturbative corrections
to the Landau gauge ghost-gluon vertex in terms of the non-vanishing
dimension-two gluon condensate. We pay special attention to the kinematical
limit which the bare vertex takes for its tree-level expression at any
perturbative order, according to the well-known Taylor theorem. Based on our
OPE analysis, we also present a simple model for the vertex, in acceptable
agreement with lattice data.Comment: Final version published in JHE
Neural development features: Spatio-temporal development of the Caenorhabditis elegans neuronal network
The nematode Caenorhabditis elegans, with information on neural connectivity,
three-dimensional position and cell linage provides a unique system for
understanding the development of neural networks. Although C. elegans has been
widely studied in the past, we present the first statistical study from a
developmental perspective, with findings that raise interesting suggestions on
the establishment of long-distance connections and network hubs. Here, we
analyze the neuro-development for temporal and spatial features, using birth
times of neurons and their three-dimensional positions. Comparisons of growth
in C. elegans with random spatial network growth highlight two findings
relevant to neural network development. First, most neurons which are linked by
long-distance connections are born around the same time and early on,
suggesting the possibility of early contact or interaction between connected
neurons during development. Second, early-born neurons are more highly
connected (tendency to form hubs) than later born neurons. This indicates that
the longer time frame available to them might underlie high connectivity. Both
outcomes are not observed for random connection formation. The study finds that
around one-third of electrically coupled long-range connections are late
forming, raising the question of what mechanisms are involved in ensuring their
accuracy, particularly in light of the extremely invariant connectivity
observed in C. elegans. In conclusion, the sequence of neural network
development highlights the possibility of early contact or interaction in
securing long-distance and high-degree connectivity
A deeply branching thermophilic bacterium with an ancient acetyl-CoA pathway dominates a subsurface ecosystem
<div><p>A nearly complete genome sequence of <em>Candidatus</em> ‘Acetothermum autotrophicum’, a presently uncultivated bacterium in candidate division OP1, was revealed by metagenomic analysis of a subsurface thermophilic microbial mat community. Phylogenetic analysis based on the concatenated sequences of proteins common among 367 prokaryotes suggests that <em>Ca.</em> ‘A. autotrophicum’ is one of the earliest diverging bacterial lineages. It possesses a folate-dependent Wood-Ljungdahl (acetyl-CoA) pathway of CO<sub>2</sub> fixation, is predicted to have an acetogenic lifestyle, and possesses the newly discovered archaeal-autotrophic type of bifunctional fructose 1,6-bisphosphate aldolase/phosphatase. A phylogenetic analysis of the core gene cluster of the acethyl-CoA pathway, shared by acetogens, methanogens, some sulfur- and iron-reducers and dechlorinators, supports the hypothesis that the core gene cluster of <em>Ca.</em> ‘A. autotrophicum’ is a particularly ancient bacterial pathway. The habitat, physiology and phylogenetic position of <em>Ca.</em> ‘A. autotrophicum’ support the view that the first bacterial and archaeal lineages were H<sub>2</sub>-dependent acetogens and methanogenes living in hydrothermal environments.</p> </div
Definitions, Criteria and Global Classification of Mast Cell Disorders with Special Reference to Mast Cell Activation Syndromes: A Consensus Proposal
Activation of tissue mast cells (MCs) and their abnormal growth and accumulation in various organs are typically found in primary MC disorders also referred to as mastocytosis. However, increasing numbers of patients are now being informed that their clinical findings are due to MC activation (MCA) that is neither associated with mastocytosis nor with a defined allergic or inflammatory reaction. In other patients with MCA, MCs appear to be clonal cells, but criteria for diagnosing mastocytosis are not met. A working conference was organized in 2010 with the aim to define criteria for diagnosing MCA and related disorders, and to propose a global unifying classification of all MC disorders and pathologic MC reactions. This classification includes three types of `MCA syndromes' (MCASs), namely primary MCAS, secondary MCAS and idiopathic MCAS. MCA is now defined by robust and generally applicable criteria, including (1) typical clinical symptoms, (2) a substantial transient increase in serum total tryptase level or an increase in other MC-derived mediators, such as histamine or prostaglandin D 2, or their urinary metabolites, and (3) a response of clinical symptoms to agents that attenuate the production or activities of MC mediators. These criteria should assist in the identification and diagnosis of patients with MCAS, and in avoiding misdiagnoses or overinterpretation of clinical symptoms in daily practice. Moreover, the MCAS concept should stimulate research in order to identify and exploit new molecular mechanisms and therapeutic targets. Copyright (C) 2011 S. Karger AG, Base
Familial predisposition to hypertension and the association between urinary sodium excretion and blood pressure in a population-based sample of young adults<A NAME="Home"></A>
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