3,844 research outputs found

    Chronic hyperplastic anemia as an independent risk factor for atherosclerotic lesions: a lesson from thalassemia intermedia

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    Introduction. Cardiovascular involvement represents a well-known complication and the primary cause of mortality, both in transfusion-dependent beta thalassemia major (β-TM) and in transfusion-independent beta thalassemia intermedia (β-TI). In β-TM, heart iron overload is considered the main cause of this complication. This is likely due to poor adherence to iron-chelating therapy, resulting in the inability of the body to efficiently remove iron excess derived from transfused red blood cell breakdown. Different clinical pictures may instead be evoked in cardiovascular involvement occurring in β-TI; however, until now, no factor has emerged as the major one responsible for these complications. 
Design and Methods. In the present study, iron status, and lipid profiles in serum, as well as lipid content in peripheral blood mononuclear cells (PBMCs) were evaluated in 70 adult β-TM and in 22 adult β-TI patients. Ninety-two age-matched blood donors, free from any form of thalassemia, were utilized as controls. The mRNA levels of genes involved in the regulation of iron metabolism, such as interleukine 1 alfa (IL1α), tumor necrosis factor alfa (TNFα), as well as those involved in cholesterol homeostasis, such as acetyl-coenzymeA: cholesterol acyltransferase (ACAT-1), neutral cholesterol ester hydrolase (nCEH), and ATP binding cassette-A (ABCA1), were also evaluated in PBMCs from the above subjects.
Results. In β-TI patients, serum iron, transferrin saturation and erythropoietin levels were higher, while transferrin and hepcidin were lower, compared to both β-TM and controls. Hepcidin and ILα mRNA levels were found to be reduced in β-TI-PBMCs, while those of TNFα were increased. A reduction in total and high density lipoprotein cholesterol (TC and HDL-C) in serum, and an accumulation of neutral lipids (NL), coupled with increased mRNA levels of ACAT-1 and decreased nCEH in PBMCs were also observed in β-TI. 
Conclusions. Since most of the parameters found to be altered in β-TI patients have a key role in the initiation and progression of atherosclerosis, we suggest that cardiovascular complications in these patients may be, at least partially, dependent on the occurrence of premature atherosclerotic lesions. 
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    A Comparison of IoT Communication Libraries: APIs and Performances

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    The Internet of Things (IoT) and the number of deployed IoT devices are growing exponentially nowadays. These devices play pivotal roles in diverse domains, e.g., smart homes. Given their constrained processing and memory capacities, IoT devices communicate with one another through specialized protocols. The two main IoT communication protocols are the Constrained Application Protocol (CoAP) and Message Queuing Telemetry Transport (MQTT). By March 1, 2023, there were 35 public libraries of CoAP and 40 of MQTT. These libraries have different characteristics, including levels of completeness and runtime performances. Because of diverse requirements in different domains, the same protocol/library does not apply to any applications. Consequently, developers must select a library (e.g., Californium, java-coap, Paho MQTT, or HiveMQ MQTT Client) but they do not have access to comprehensive and clear comparisons of the API and performance of these protocols and their implementations, impeding their ability to make informed choices. In this thesis, we implement multiple IoT scenarios using the CoAP and MQTT protocols and several of their implementation libraries. We conduct a comprehensive comparative analysis based on API and performance metrics, including static metrics, packet sizes, and runtime performance. We thus provide developers with evidence to choose between CoAP and MQTT protocols and their libraries. In future work, we will expand this work to include other IoT protocols and libraries, more scenarios and metrics

    Evidence for a correlation between the sizes of quiescent galaxies and local environment to z ~ 2

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    We present evidence for a strong relationship between galaxy size and environment for the quiescent population in the redshift range 1 < z < 2. Environments were measured using projected galaxy overdensities on a scale of 400 kpc, as determined from ~ 96,000 K-band selected galaxies from the UKIDSS Ultra Deep Survey (UDS). Sizes were determined from ground-based K-band imaging, calibrated using space-based CANDELS HST observations in the centre of the UDS field, with photometric redshifts and stellar masses derived from 11-band photometric fitting. From the resulting size-mass relation, we confirm that quiescent galaxies at a given stellar mass were typically ~ 50 % smaller at z ~ 1.4 compared to the present day. At a given epoch, however, we find that passive galaxies in denser environments are on average significantly larger at a given stellar mass. The most massive quiescent galaxies (M_stellar > 2 x 10^11 M_sun) at z > 1 are typically 50 % larger in the highest density environments compared to those in the lowest density environments. Using Monte Carlo simulations, we reject the null hypothesis that the size-mass relation is independent of environment at a significance > 4.8 sigma for the redshift range 1 < z < 2. In contrast, the evidence for a relationship between size and environment is much weaker for star-forming galaxies.Comment: Accepted for publication in MNRAS. 16 pages, 11 figures, 6 table

    The protection of Victoria Harbour in Hong Kong : an analysis of civic engagement strategies

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    published_or_final_versionPolitics and Public AdministrationMasterMaster of Public Administratio

    A conserved amino-terminal Shc domain binds to phosphotyrosine motifs in activated receptors and phosphopeptides

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    AbstractBackground: Signal transduction by growth factor receptor protein-tyrosine kinases is generally initiated by autophosphorylation on tyrosine residues following ligand binding. Phosphotyrosines within activated receptors form binding sites for the Src homology 2 (SH2) domains of cytoplasmic signalling proteins. One such protein, Shc, is tyrosine phosphorylated in response to a large number of growth factors and cytokines. Phosphorylation of Shc on tyrosine residue Y317 allows binding to the SH2 domain of Grb2, and hence stimulation of the Ras pathway. Shc is therefore implicated as an adaptor protein able to couple normal and oncogenic protein-tyrosine kinases to Ras activation. Shc itself contains an SH2 domain at its carboxyl terminus, but the function of the amino-terminal half of the protein is unknown.Results We have found that the Shc amino-terminal region binds to a number of tyrosine-phosphorylated proteins in v-src-transformed cells. This domain also bound directly to the activated epidermal growth factor (EGF) receptor. A phosphotyrosine (pY)-containing peptide modeled after the Shc-binding site in polyoma middle T antigen (LLSNPTpYSVMRSK) was able to compete efficiently with the activated EGF receptor for binding to the Shc amino terminus. This competition was dependent on phosphorylation of the tyrosine residue within the peptide, and was abrogated by deletion of the leucine residue at position –5. The Shc amino-terminal domain also bound to the autophosphorylated nerve growth factor receptor (Trk), but bound significantly less well to a mutant receptor in which tyrosine Y490 in the receptor's Shc-binding site had been substituted by phenylalanine.Conclusion These data implicate the amino-terminal region of Shc in binding to activated receptors and other tyrosine-phosphorylated proteins. Binding appears to be specific for phosphorylated tyrosine residues within the sequence NPXpY, which is conserved in many Shc-binding sites. The Shc amino-terminal region bears only very limited sequence identity to known SH2 domains, suggesting that it represents a new class of phosphotyrosine-binding modules. Consistent with this view, the amino-terminal Shc domain is highly conserved in a Drosophila Shc homologue. Binding of Shc to activated receptors through its amino terminus could leave the carboxy-terminal SH2 domain free for other interactions. In this way, Shc may function as an adaptor protein to bring two tyrosine-phosphorylated proteins together

    A Comparative Study of Patients’ Attitudes Toward Clinical Research in the United States and Urban and Rural China

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    As the number of clinical trials conducted in China increases, understanding Chinese attitudes toward clinical research is critical for designing effective and ethical studies. Two survey studies were conducted in 2012 and 2013 to compare patient attitudes toward clinical research and factors affecting research participation in the United States and urban and rural China. We surveyed 525 patients in 2012 (186 US, 186 urban, 153 rural China) and 690 patients in 2013 (412 US, 206 urban, 72 rural China). US patients were more likely to have no concerns regarding research participation than Chinese patients. Most common concerns of US patients were safety, privacy and confidentiality, and time required. Safety was a top concern for many Chinese. Chinese patients, particularly rural Chinese, were more concerned about the likelihood of self‐benefit, and receiving free medical care and financial incentive had greater influence on their participation. Being informed of the freedom to choose whether to participate or to leave a study was less important to Chinese patients. Our study provides important insights into Chinese patients' attitudes toward clinical research and the need to educate them about their rights. These findings help in designing cross‐cultural clinical studies that maximize enrollment while upholding Western ethical standards.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111170/1/cts12254.pd

    Designing and implementing a COPD discharge care bundle

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    National surveys have revealed significant differences in patient outcomes following admission to hospital with acute exacerbation of COPD which are likely to be due to variations in care. We developed a care bundle, comprising a short list of evidence-based practices to be implemented prior to discharge for all patients admitted with this condition, based on a review of national guidelines and other relevant literature, expert opinion and patient consultation. Implementation was then piloted using action research methodologies with patient input. Actively involving staff was vital to ensure that the changes introduced were understood and the process followed. Implementation of a care bundle has the potential to produce a dramatic improvement in compliance with optimum health care practice

    FRP-to-masonry bond durability assessment with infrared thermography method

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    The bond behavior between FRP composites and masonry substrate plays an important role in the performance of externally bonded reinforced masonry structures. Therefore, monitoring the bond quality during the application and subsequent service life of a structure is of crucial importance for execution control and structural health monitoring. The bond quality can change during the service life of the structure due to environmental conditions. Local detachments may occur at the FRP/substrate interface, affecting the bond performance to a large extent. Therefore, the use of expedite and efficient non-destructive techniques for assessment of the bond quality and monitoring FRP delamination is of much interest. Active infrared thermography (IR) technique was used in this study for assessing the bond quality in environmentally degraded FRP-strengthened masonry elements. The applicability and accuracy of the adopted method was initially validated by localization and size quantification of artificially embedded defects in FRP-strengthened brick specimens. Then, the method was used for investigating the appearance and progression of FRP delaminations due to environmental conditions. GFRP-strengthened brick specimens were exposed to accelerated hygrothermal ageing tests and inspected periodically with the IR camera. The results showed environmental exposure may produce large progressive FRP delaminations.Fundação para a CiĂȘncia e Tecnologi
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