169 research outputs found
A GRASP-based heuristic for allocating the roadside infrastructure maximizing the number of distinct vehicles experiencing contact opportunities
In this work the allocation of Roadside Units (RSUs) in a V2I network is modeled as a Maximum Coverage Problem. The main objective is to maximize the number of distinct vehicles contacting the infrastructure. Two different approaches are presented to solve the problem. The first one is an ILP model that can found optimal solutions or give sharp upper and lower bounds for the problem. The second one is a GRASP-based heuristic that can found close-to-optimal solutions. The GRASP-based heuristic is compared with a previous work achieving better results. Furthermore, a new metric to measure the efficiency of a Deployment strategy is presented
Validation of a quantitative lateral flow immunoassay (LFIA)-based point-of-care (POC) rapid test for SARS-CoV-2 neutralizing antibodies
With the widespread use of coronavirus disease 2019 (COVID-19) vaccines, a rapid and reliable method to detect SARS-CoV-2 neutralizing antibodies (NAbs) is extremely important for monitoring vaccine effectiveness and immunity in the population. The purpose of this study was to evaluate the performance of the RapiRead (TM) reader and the TestNOW (TM) COVID-19 NAb rapid point-of-care (POC) test for quantitative measurement of antibodies against the spike protein receptor-binding domain of severe respiratory syndrome coronavirus 2 (SARS-CoV-2) in different biological matrices compared to chemiluminescence immunoassay (CLIA) methods. Ninety-four samples were collected and analyzed using a RapiRead (TM) reader and TestNOW (TM) COVID-19 NAb kits for detecting neutralizing antibodies, and then using two CLIAs. The data were compared statistically using the Kruskal-Wallis test for more than two groups or the Mann-Whitney test for two groups. Specificity and sensitivity were evaluated using a receiver operating characteristic (ROC) curve. Good correlation was observed between the rapid lateral flow immunoassay (LFIA) test system and both CLIA methods. RapiRead (TM) reader/TestNOW (TM) COVID-19 NAb vs. Maglumi: correlation coefficient (r) = 0.728 for all patients; r = 0.841 for vaccinated patients. RapiRead (TM) reader/TestNOW (TM) COVID-19 NAb vs. Mindray: r = 0.6394 in all patients; r = 0.8724 in vaccinated patients. The time stability of the POC serological test was also assessed considering two times of reading, 12 and 14 minutes. The data revealed no significant differences. The use of a RapiRead (TM) reader and TestNOW (TM) COVID-19 NAb assay is a quantitative, rapid, and valid method for detecting SARS-CoV-2 neutralizing antibodies and could be a useful tool for screening studies of SARS-CoV-2 infection and assessing the efficacy of vaccines in a non-laboratory context
Uso de controlador PID como tecnologia eficiente em sistema de aquecimento de creche suína
End-stage heart failure in congenitally corrected transposition of the great arteries:a multicentre study
BACKGROUND AND AIMS: For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear. METHODS: This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death. RESULTS: From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome. CONCLUSIONS: Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.</p
A Multicenter, Long-Term Study on Arrhythmias in Children with Ebstein Anomaly
To assess the prevalence, history, and treatment of arrhythmias, in particular preexcitation and Wolff–Parkinson–White (WPW) syndrome, in patients with Ebstein anomaly (EA) during childhood and adolescence, we performed a multicenter retrospective study of all consecutive live-born patients with EA, diagnosed, and followed by pediatric cardiologists between 1980 and 2005 in The Netherlands. During a follow-up after EA diagnosis of 13 years 3 months (range: 6 days to 28 years 2 months), 16 (17%) of the 93 pediatric EA patients exhibited rhythm disturbances. Nine patients showed arrhythmic events starting as of the neonatal period. Supraventricular tachycardia was noted in 11 patients. One patient died in the neonatal period due to intractable supraventricular tachycardia resulting in heart failure and one patient died at 5 weeks of age most probably due to an arrhythmic event. The 14 surviving patients all show preexcitation, albeit 4 of them intermittently, and all have a right-sided accessory pathway location. Nine patients underwent catheter ablation of an accessory pathway. Only four patients are currently on antiarrhythmic drugs. The 17% prevalence of rhythm disturbances in pediatric EA patients, most commonly supraventricular arrhythmias, is significantly lower than in adult EA patients. Life-threatening rhythm disturbances are not frequent early in life. Symptomatic patients are well treated with radiofrequency catheter ablation
Massive-Scale RNA-Seq Analysis of Non Ribosomal Transcriptome in Human Trisomy 21
Hybridization- and tag-based technologies have been successfully used in Down
syndrome to identify genes involved in various aspects of the pathogenesis.
However, these technologies suffer from several limits and drawbacks and, to
date, information about rare, even though relevant, RNA species such as long and
small non-coding RNAs, is completely missing. Indeed, none of published works
has still described the whole transcriptional landscape of Down syndrome.
Although the recent advances in high-throughput RNA sequencing have revealed the
complexity of transcriptomes, most of them rely on polyA enrichment protocols,
able to detect only a small fraction of total RNA content. On the opposite end,
massive-scale RNA sequencing on rRNA-depleted samples allows the survey of the
complete set of coding and non-coding RNA species, now emerging as novel
contributors to pathogenic mechanisms. Hence, in this work we analysed for the
first time the complete transcriptome of human trisomic endothelial progenitor
cells to an unprecedented level of resolution and sensitivity by RNA-sequencing.
Our analysis allowed us to detect differential expression of even low expressed
genes crucial for the pathogenesis, to disclose novel regions of active
transcription outside yet annotated loci, and to investigate a
plethora of non-polyadenilated long as well as short non coding RNAs. Novel
splice isoforms for a large subset of crucial genes, and novel extended
untranslated regions for known genes—possibly novel miRNA targets or
regulatory sites for gene transcription—were also identified in this
study. Coupling the rRNA depletion of samples, followed by high-throughput
RNA-sequencing, to the easy availability of these cells renders this approach
very feasible for transcriptome studies, offering the possibility of
investigating in-depth blood-related pathological features of Down syndrome, as
well as other genetic disorders
Impairment of circulating endothelial progenitors in Down syndrome
<p>Abstract</p> <p>Background</p> <p>Pathological angiogenesis represents a critical issue in the progression of many diseases. Down syndrome is postulated to be a systemic anti-angiogenesis disease model, possibly due to increased expression of anti-angiogenic regulators on chromosome 21. The aim of our study was to elucidate some features of circulating endothelial progenitor cells in the context of this syndrome.</p> <p>Methods</p> <p>Circulating endothelial progenitors of Down syndrome affected individuals were isolated, <it>in vitro </it>cultured and analyzed by confocal and transmission electron microscopy. ELISA was performed to measure SDF-1α plasma levels in Down syndrome and euploid individuals. Moreover, qRT-PCR was used to quantify expression levels of <it>CXCL12 </it>gene and of its receptor in progenitor cells. The functional impairment of Down progenitors was evaluated through their susceptibility to hydroperoxide-induced oxidative stress with BODIPY assay and the major vulnerability to the infection with human pathogens. The differential expression of crucial genes in Down progenitor cells was evaluated by microarray analysis.</p> <p>Results</p> <p>We detected a marked decrease of progenitors' number in young Down individuals compared to euploid, cell size increase and some major detrimental morphological changes. Moreover, Down syndrome patients also exhibited decreased SDF-1α plasma levels and their progenitors had a reduced expression of SDF-1α encoding gene and of its membrane receptor. We further demonstrated that their progenitor cells are more susceptible to hydroperoxide-induced oxidative stress and infection with Bartonella henselae. Further, we observed that most of the differentially expressed genes belong to angiogenesis, immune response and inflammation pathways, and that infected progenitors with trisomy 21 have a more pronounced perturbation of immune response genes than infected euploid cells.</p> <p>Conclusions</p> <p>Our data provide evidences for a reduced number and altered morphology of endothelial progenitor cells in Down syndrome, also showing the higher susceptibility to oxidative stress and to pathogen infection compared to euploid cells, thereby confirming the angiogenesis and immune response deficit observed in Down syndrome individuals.</p
The Role of relA and spoT in Yersinia pestis KIM5+ Pathogenicity
The ppGpp molecule is part of a highly conserved regulatory system for mediating the growth response to various environmental conditions. This mechanism may represent a common strategy whereby pathogens such as Yersinia pestis, the causative agent of plague, regulate the virulence gene programs required for invasion, survival and persistence within host cells to match the capacity for growth. The products of the relA and spoT genes carry out ppGpp synthesis. To investigate the role of ppGpp on growth, protein synthesis, gene expression and virulence, we constructed a ΔrelA ΔspoT Y. pestis mutant. The mutant was no longer able to synthesize ppGpp in response to amino acid or carbon starvation, as expected. We also found that it exhibited several novel phenotypes, including a reduced growth rate and autoaggregation at 26°C. In addition, there was a reduction in the level of secretion of key virulence proteins and the mutant was>1,000-fold less virulent than its wild-type parent strain. Mice vaccinated subcutaneously (s.c.) with 2.5×104 CFU of the ΔrelA ΔspoT mutant developed high anti-Y. pestis serum IgG titers, were completely protected against s.c. challenge with 1.5×105 CFU of virulent Y. pestis and partially protected (60% survival) against pulmonary challenge with 2.0×104 CFU of virulent Y. pestis. Our results indicate that ppGpp represents an important virulence determinant in Y. pestis and the ΔrelA ΔspoT mutant strain is a promising vaccine candidate to provide protection against plague
Comparative Activity of Meropenem (SM-7338) Against Major Respiratory Pathogens and Amikacin-Resistant Nosocomial Isolates
Meropenem, a new broad-spectrum carbapenem antibiotic, demonstrated excellent in vitro activity against major respiratory pathogens including Moraxella catarrhalis, Haemophilus influenzae and Streptococcus pneumoniae. Minimal inhibitory concentrations of meropenem for Moraxella catarrhalis and Haemophilus influenzae isolates were frequently less than those of imipenem. For nosocomial amikacin-resistant gram-negative bacilli, meropenem had eightfold lower MIC90 values compared to imipenem against strains of Serratia marcescens, Enterobacter cloacae and Escherichia coli; it was 32-fold more active than imipenem against Proteus mirabilis isolates. Activity was similar to that of imipenem against Pseudomonas aeruginosa isolates. Overall, meropenem showed excellent activity against common community-acquired pathogens as well as amikacin-resistant nosocomial pathogens
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