1,187 research outputs found
Confinement of Masonry Columns with Natural Lime-Based Mortar Composite: An Experimental Investigation
The paper presents the results of an experimental campaign on the confinement of masonry square columns with fiber-reinforced lime mortar (FRLM) composites made of a natural lime-based matrix. The experimental results show the effectiveness of such a composite for increasing both strength and ductility performances of strengthened columns. Predictive formulas from the literature and from the Italian guidelines CNR-DT 215/2018 do not perfectly fit the experimental outcomes and do not confirm the strength increase of the confined columns. The reason can be attributed to the very low mechanical properties of the natural matrix used to form such a composite. Therefore, considering that the use of a natural and sustainable matrix fully compatible with the masonry substrate is a fundamental requirement for strengthening masonry columns of buildings belonging to architectural heritage, an additional future effort should be made by researchers involved in this field. In particular, for a reliable prediction of the strength of masonry columns confined with composites made of natural matrices, wider experimental campaigns are necessary to refine available formulas with respect to different substrates and component materials
Heat transfer enhancement in turbulent boundary layers with a pulsed slot jet in crossflow
The convective heat transfer enhancement in a turbulent boundary layer (TBL) employing a pulsed, slot jet in crossflow is investigated experimentally. A parametric study on actuation frequencies and duty cycles is performed. The actuator is a flush-mounted slot jet that injects fluid into a well-behaved zero-pressure-gradient TBL over a flat plate. A heated-thin-foil sensor measures the time-averaged convective heat transfer coefficient downstream of the actuator location and the flow field is characterised by means of Particle Image Velocimetry. The results show that both the jet penetration in the streamwise direction and the overall Nusselt number increase with increasing duty cycle. The frequency at which the Nusselt number is maximised is independent of the duty cycle. The flow topology is considerably altered by the jet pulsation. A wall-attached jet rises from the slot accompanied by a pair of counter-rotating vortices that promote flow entrainment and mixing. Eventually, a simplified model is proposed which decouples the effect of pulsation frequency and duty cycle in the overall heat transfer enhancement, with a good agreement with experimental data. The cost of actuation is also quantified in terms of the amount of injected fluid during the actuation, leading to conclude that the lowest duty cycle is the most efficient for heat transfer enhancement.The work has been supported by the project ARTURO, ref. PID2019-109717RB-I00/AEI/10.13039/501100011033, funded by the Spanish State Research Agency. Funding for APC: Universidad Carlos III de Madrid (Read & Publish Agreement CRUE-CSIC 2022). Paul Murphy is kindly acknowledged for his support during the experimental campaign
Graphene sustained nonlinear modes in dielectric waveguides
We discuss the existence of nonlinear modes sustained by graphene layers in dielectric waveguides. Taking advantage of the almost two dimensional nature of graphene, we introduce the nonlinear effect as a parameter in the continuity equations. We then apply our modeling to a simple slab waveguide to enlighten how graphene can be used to induce huge nonlinear phase shifts at easily accessible power levels
In-Vivo Real-Time Control of Protein Expression from Endogenous and Synthetic Gene Networks
We describe an innovative experimental and computational approach to control the expression of a protein in a population of yeast cells. We designed a simple control algorithm to automatically regulate the administration of inducer molecules to the cells by comparing the actual protein expression level in the cell population with the desired expression level. We then built an automated platform based on a microfluidic device, a time-lapse microscopy apparatus, and a set of motorized syringes, all controlled by a computer. We tested the platform to force yeast cells to express a desired fixed, or time-varying, amount of a reporter protein over thousands of minutes. The computer automatically switched the type of sugar administered to the cells, its concentration and its duration, according to the control algorithm. Our approach can be used to control expression of any protein, fused to a fluorescent reporter, provided that an external molecule known to (indirectly) affect its promoter activity is available
Integrated Analysis of Myocardial Blush and ST-Segment Elevation Recovery After Successful Primary Angioplasty
Background
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ST-segment elevation (ÎŁSTe) recovery and the angiographic myocardial blush (MB) grade are useful markers of microvascular reperfusion after recanalization of the infarct-related artery. We investigated the ability of a combined analysis of MB grade and ÎŁSTe changes to identify different patterns of myocardial reperfusion shortly after primary percutaneous coronary angioplasty (PTCA) and to predict 7-day and 6-month left ventricular (LV) functional recovery.
Methods and Results
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MB grade and ÎŁSTe recovery were evaluated shortly after successful primary PTCA (restoration of TIMI grade 3 flow) in 114 consecutive patients with ÎŁSTe acute myocardial infarction. LV function was assessed by 2D echocardiograms before PTCA and at 7 days and 6 months thereafter. By combining MB and ÎŁSTe changes, 3 main groups of patients were identified. Group 1 patients (n=60) had both significant MB (grade 2 to 3) and ÎŁSTe recovery (>50% versus basal ÎŁSTe) and a high rate of 7-day (65%) and 6-month (95%) LV functional recovery. In group 2 patients (n=21), who showed MB but persistent ÎŁSTe, the prevalence of early LV functional recovery was low (24%) but increased up to 86% in the late phase. Group 3 patients (n=28), who had neither significant MB nor ÎŁSTe resolution, had poor early (18%) and late (32%) LV functional recovery.
Conclusions
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After successful primary PTCA, integrated analysis of MB and ÎŁSTe recovery allows a real-time grading of microvascular reperfusion of the infarct area and predicts the time-course and magnitude of LV functional recovery
Haplotypes in SLC24A5 Gene as Ancestry Informative Markers in Different Populations
Ancestry informative markers (AIMs) are human polymorphisms that exhibit substantially allele frequency differences among populations. These markers can be useful to provide information about ancestry of samples which may be useful in predicting a perpetrator’s ethnic origin to aid criminal investigations. Variations in human pigmentation are the most obvious phenotypes to distinguish individuals. It has been recently shown that the variation of a G in an A allele of the coding single-nucleotide polymorphism (SNP) rs1426654 within SLC24A5 gene varies in frequency among several population samples according to skin pigmentation. Because of these observations, the SLC24A5 locus has been evaluated as Ancestry Informative Region (AIR) by typing rs1426654 together with two additional intragenic markers (rs2555364 and rs16960620) in 471 unrelated individuals originating from three different continents (Africa, Asia and Europe). This study further supports the role of human SLC24A5 gene in skin pigmentation suggesting that variations in SLC24A5 haplotypes can correlate with human migration and ancestry. Furthermore, our data do reveal the utility of haplotype and combined unphased genotype analysis of SLC24A5 in predicting ancestry and provide a good example of usefulness of genetic characterization of larger regions, in addition to single polymorphisms, as candidates for population-specific sweeps in the ancestral population
Gut microbiota markers in obese adolescent and adult patients: Age-dependent differential patterns
Obesity levels, especially in children, have dramatically increased over the last few decades. Recently, several studies highlighted the involvement of gut microbiota in the pathophysiology of obesity. We investigated the composition of gut microbiota in obese adolescents and adults compared to age-matched normal weight (NW) volunteers in order to assemble age- and obesity-related microbiota profiles. The composition of gut microbiota was analyzed by 16S rRNA-based metagenomics. Ecological representations of microbial communities were computed, and univariate, multivariate, and correlation analyses performed on bacterial profiles. The prediction of metagenome functional content from 16S rRNA gene surveys was carried out. Ecological analyses revealed a dissimilarity among the subgroups, and resultant microbiota profiles differed between obese adolescents and adults. Using statistical analyses, we assigned, as microbial markers, Faecalibacterium prausnitzii and Actinomyces to the microbiota of obese adolescents, and Parabacteroides, Rikenellaceae, Bacteroides caccae, Barnesiellaceae, and Oscillospira to the microbiota of NW adolescents. The predicted metabolic profiles resulted different in adolescent groups. Particularly, biosynthesis of primary bile acid and steroid acids, metabolism of fructose, mannose, galactose, butanoate, and pentose phosphate and glycolysis/gluconeogenesis were for the majority associated to obese, while biosynthesis and metabolism of glycan, biosynthesis of secondary bile acid, metabolism of steroid hormone and lipoic acid were associated to NW adolescents. Our study revealed unique features of gut microbiota in terms of ecological patterns, microbial composition and metabolism in obese patients. The assignment of novel obesity bacterial markers may open avenues for the development of patient-tailored treatments dependent on age-related microbiota profiles
CYP1A1 Variability In Human Populations
The human cytochrome P4501A1 (CYP1A1) enzyme plays an important role in the metabolism of xenobiotics and endogenous substrates. Because polymorphisms within the CYP1A1 gene have been shown to be associated with various cancer risks and with the predicting clinical efficacy of some chemotherapies in different populations, most studies focus on their clinical significance. We, however, were interested in evaluating whether the polymorphisms could be used to distinguish human populations. Four single nucleotide CYP1A1 polymorphisms (rs4646903/ g.75011641; rs1048943/g.75012985; g.75012235; and rs1799814/ g.75012987) were analysed via PCR-RFLP assay in 1,195 individuals of various human groups from all over the world. In order to gain a more complete view of the genetic variability of the CYP1A1 gene, different statistical analyses were performed upon the populations of the present study and upon the limited data gleaned from previously studied populations. The allele and haplotype frequencies vary among populations: the rs4646903 (C) and rs1048943 (G) have been found to be nearly always linked and were found at the highest frequencies in Native Americans, while the variant associated to the position g.75012235 was only detected in certain African populations. Our work clearly indicates that the CYP1A1 polymorphisms differ among populations and that the prediction of genotypes constitutes an important aspect of precision medicine since some variants were associated with certain cancers and rs1048943 show strong association with optimized chemotherapy. Moreover, the CYP1A1 gene plays an important role in the metabolism of xenobiotics and it is likely that its frequencies could be strongly influenced by environmental factors
Adverse psychiatric effects associated with herbal weight-loss products
Date of Acceptance: 02/08/2015. Copyright © 2015 F. Saverio Bersani et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedObesity and overeating are among the most prevalent health concerns worldwide and individuals are increasingly using performance and image-enhancing drugs (PIEDs) as an easy and fast way to control their weight. Among these, herbal weight-loss products (HWLPs) often attract users due to their health claims, assumed safety, easy availability, affordable price, extensive marketing, and the perceived lack of need for professional oversight. Reports suggest that certain HWLPs may lead to onset or exacerbation of psychiatric disturbances. Here we review the available evidence on psychiatric adverse effects of HWLPs due to their intrinsic toxicity and potential for interaction with psychiatric medicationsPeer reviewe
Trigeminal neuropathy presenting secondary to SARS-CoV-2 infection.
IntroductionA 58-year-old woman presented to a multidisciplinary facial pain clinic in October 2021 complaining of a constant pain in the right side of her face since contracting coronavirus SARS-CoV-2 18 months earlier. The pain extending from the right temple down to her right cheek extraorally and including the maxillary teeth and right side of tongue intraorally. This was accompanied by anosmia, diplopia on lateral gaze, and dizziness.MethodsClinical examination was supplemented with several neurophysiological tests to confirm the diagnosis including an MRI brain scan, quantitative sensory testing, electrophysiological blink reflex testing, corneal confocal microscopy, and pain and short-form anxiety and depression questionnaires.ResultsQuantitative sensory testing showed unilateral loss of perception in thermal and mechanical sensibility and bilateral hyperalgesia indicating central sensitization. Bilateral corneal confocal microscopy showed an abnormally reduced corneal nerve fibre length on the right side. MRI, blink reflex, and masseter inhibitory testing findings were normal.ConclusionThis case study is the first case of trigeminal neuropathy related to SARS-CoV-2 infection reported in the literature. It also discusses the successful management of the patient's trigeminal neuropathic pain
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