41 research outputs found
Flow responses alteration by geometrical effects of tubercles on plates under the maximal angle of attack
Plates with leading-edge tubercles experience beneficially more gradual aerodynamics stalling when entering the poststall regime. Little is known, however, about the corresponding aquatic flow responses when these tubercles-furnished
plates are subjected to the maximal angle of attack, with the flow direction perpendicular to their planar area. Hence,
this study presents numerically, by means of the flow behavior solver ANSYS, the flow responses alteration in terms of
the geometrical effects of tubercles on plates through changes in amplitudes (5 mm, 10 mm, 15 mm) and wavelengths
(50 mm, 100 mm, 150 mm) under the maximal angle of attack in comparison to a control case, i.e., without tubercles.
Additional to the commonly examined flow velocity and pressure, characteristics such as wake (area, reattachment
length, flow recirculation intensity) and newly defined downstream vortical parameters (area, perimeter, and Feret
diameters) for the vortex region have been proposed and assessed. It is found that the drag increases with the tubercle
wavelength but corresponds inversely with the tubercle amplitude. By correlating with the best beneficial velocity and
pressure profiles, it has been characterized that the optimally performing plate is the one that generates the greatest
flow recirculation intensity, wake area, and reattachment length, corresponding to the capability to produce also the
highest vortical area, perimeter, and major Feret diameter. Compared to the control case, all plates with tubercles alter
beneficially these flow behaviors. In conclusion, plates with tubercles contribute favorably to the flow behaviors under
the maximal angle of attack compared to the control case while the newly proposed downstream parameters could
serve capably as alternatives in corroborating the flow physics description in future studies
Variation in Uteroglobin-Related Protein 1 (UGRP1) gene is associated with Allergic Rhinitis in Singapore Chinese
<p>Abstract</p> <p>Background</p> <p>Uteroglobin-Related Protein 1 (<it>UGRP1</it>) is a secretoglobulin protein which has been suggested to play a role in lung inflammation and allergic diseases. UGRP1 has also been shown to be an important pneumoprotein, with diagnostic potential as a biomarker of lung damage. Previous genetic studies evaluating the association between variations on <it>UGRP1 </it>and allergic phenotypes have yielded mixed results. The aim of this present study was to identify genetic polymorphisms in <it>UGRP1 </it>and investigate if they were associated with asthma and allergic rhinitis in the Singapore Chinese population.</p> <p>Methods</p> <p>Resequencing of the <it>UGRP1 </it>gene was conducted on 40 randomly selected individuals from Singapore of ethnic Chinese origin. The polymorphisms identified were then tagged and genotyped in a population of 1893 Singapore Chinese individuals. Genetic associations were evaluated in this population comparing 795 individuals with allergic rhinitis, 718 with asthma (of which 337 had both asthma and allergic rhinitis) and 717 healthy controls with no history of allergy or allergic diseases.</p> <p>Results</p> <p>By resequencing the <it>UGRP1 </it>gene within our population, we identified 11 novel and 16 known single nucleotide polymorphisms (SNPs). TagSNPs were then genotyped, revealing a significant association between rs7726552 and allergic rhinitis (Odds Ratio: 0.81, 95% Confidence Interval: 0.66-0.98, P = 0.039). This association remained statistically significant when it was analyzed genotypically or when stratified according to haplotypes. When variations on <it>UGRP1 </it>were evaluated against asthma, no association was observed.</p> <p>Conclusion</p> <p>This study documents the association between polymorphisms in <it>UGRP1 </it>and allergic rhinitis, suggesting a potential role in its pathogenesis.</p
Small Cationic DDA:TDB Liposomes as Protein Vaccine Adjuvants Obviate the Need for TLR Agonists in Inducing Cellular and Humoral Responses
Most subunit vaccines require adjuvants in order to induce protective immune responses to the targeted pathogen. However, many of the potent immunogenic adjuvants display unacceptable local or systemic reactogenicity. Liposomes are spherical vesicles consisting of single (unilamellar) or multiple (multilamellar) phospholipid bi-layers. The lipid membranes are interleaved with an aqueous buffer, which can be utilised to deliver hydrophilic vaccine components, such as protein antigens or ligands for immune receptors. Liposomes, in particular cationic DDA:TDB vesicles, have been shown in animal models to induce strong humoral responses to the associated antigen without increased reactogenicity, and are currently being tested in Phase I human clinical trials. We explored several modifications of DDA:TDB liposomes - including size, antigen association and addition of TLR agonists – to assess their immunogenic capacity as vaccine adjuvants, using Ovalbumin (OVA) protein as a model protein vaccine. Following triple homologous immunisation, small unilamellar vesicles (SUVs) with no TLR agonists showed a significantly higher capacity for inducing spleen CD8 IFNγ responses against OVA in comparison with the larger multilamellar vesicles (MLVs). Antigen-specific antibody reponses were also higher with SUVs. Addition of the TLR3 and TLR9 agonists significantly increased the adjuvanting capacity of MLVs and OVA-encapsulating dehydration-rehydration vesicles (DRVs), but not of SUVs. Our findings lend further support to the use of liposomes as protein vaccine adjuvants. Importantly, the ability of DDA:TDB SUVs to induce potent CD8 T cell responses without the need for adding immunostimulators would avoid the potential safety risks associated with the clinical use of TLR agonists in vaccines adjuvanted with liposomes
Impaired immune function in Gulf War Illness
<p>Abstract</p> <p>Background</p> <p>Gulf War Illness (GWI) remains a serious health consequence for at least 11,000 veterans of the first Gulf War in the early 1990s. Our understanding of the health consequences that resulted remains inadequate, and this is of great concern with another deployment to the same theater of operations occurring now. Chronic immune cell dysfunction and activation have been demonstrated in patients with GWI, although the literature is not uniform. We exposed GWI patients and matched controls to an exercise challenge to explore differences in immune cell function measured by classic immune assays and gene expression profiling.</p> <p>Methods</p> <p>This pilot study enrolled 9 GWI cases identified from the Department of Veterans Affairs GWI registry, and 11 sedentary control veterans who had not been deployed to the Persian Gulf and were matched to cases by sex, body mass index (BMI) and age. We measured peripheral blood cell numbers, NK cytotoxicity, cytokines and expression levels of 20,000 genes immediately before, immediately after and 4 hours following a standard bicycle ergometer exercise challenge.</p> <p>Results</p> <p>A repeated-measures analysis of variance revealed statistically significant differences for three NK cell subsets and NK cytotoxicity between cases and controls (p < 0.05). Linear regression analysis correlating NK cell numbers to the gene expression profiles showed high correlation of genes associated with NK cell function, serving as a biologic validation of both the <it>in vitro </it>assays and the microarray platform. Intracellular perforin levels in NK and CD8 T-cells trended lower and showed a flatter profile in GWI cases than controls, as did the expression levels of the perforin gene PRF1. Genes distinguishing cases from controls were associated with the glucocorticoid signaling pathway.</p> <p>Conclusion</p> <p>GWI patients demonstrated impaired immune function as demonstrated by decreased NK cytotoxicity and altered gene expression associated with NK cell function. Pro-inflammatory cytokines, T-cell ratios, and dysregulated mediators of the stress response (including salivary cortisol) were also altered in GWI cases compared to control subjects. An interesting and potentially important observation was that the exercise challenge augments these differences, with the most significant effects observed immediately after the stressor, possibly implicating some block in the NK and CD8 T-cells ability to respond to "stress-mediated activation". This has positive implications for the development of laboratory diagnostic tests for this syndrome and provides a paradigm for exploration of the immuno-physiological mechanisms that are operating in GWI, and similar complex syndromes. Our results do not necessarily elucidate the cause of GWI, but they do reveal a role for immune cell dysfunction in sustaining illness.</p
Emotional intelligence training intervention among trainee teachers: a quasi-experimental study
Background: Emotional intelligence (EI) has often been linked to improvements in professional performance. Indeed, generic competencies related to EI have been included in university curricula. However, learning EI involves significant time and effort on the part of students, and this may hinder the acquisition of specific content for each degree. In this study, an intervention to develop EI in higher education students is described and evaluated. Methods: The intervention consisted of eight group sessions performed in a regular course aiming to increase EI. The sessions included strategies and training on perceiving and understanding one’s own emotions and others’ emotions, identifying and understanding the impact one’s own feelings in adopting decisions, expressing one’s own emotions and the stress experienced, and managing both one’s own emotions and emotions of others. Participants were 192 students studying for a Master of Primary Education degree. A quasi-experimental nonequivalent control group pretest-posttest design was adopted. The effectiveness of the intervention was evaluated using multi-level analyses. Results: The results showed a significant improvement in the EI of students in the experimental group compared with the control group. Conclusions: This research demonstrates that it is possible to develop EI in higher education students, without hindering the acquisition of specific content competencies and, therefore, without interfering with their academic performance and without overburdening students with work outside the classroom. Trial registration: The experiment has been registered in the Initial Deposit of the Spanish Center for Sociological Research (CIS). 7/6/2015. http://www.cis.es/cis/opencms/ES/index.html.This research was supported by the Spanish Ministry of Economy and Competitiveness under Grant number EDU2015-64562-R
There is limited existing evidence to support the common assumption that strenuous endurance exercise bouts impair immune competency
Pulmonary absorption of liposomal levonorgestrel
The purpose of these studies was to achieve desired bioavailability after pulmonary administration of Levonorgestrel (LN) and to provide prolonged effective concentration of the drug in plasma and to reduce reported side effects of orally administered drug. The plain drug suspension, physical mixture (plain drug with liposomal constituents), and drug-encapsulated liposomes containing 10 μg of drug were instilled intratracheally in rats. Similarly, 10-μg drug suspension (LO) was administered orally. The blood samples were withdrawn at specific time intervals and were subjected to LN analysis by spectrofluorimetric technique. The plasma drug concentration data of both the treatments were plotted, and pharmacokinetics data were calculated and compared with that of oral administration. Percentage relative bioavailability (F*) of 97.6% 98.6%, and 109.9% were observed after pulmonary administration of plain drug formulation (LP1), physical mixture (plain drug along with constituents of liposomes [LP2], and liposomal (LP3) formulations of the drug, respectively. Following oral administration, Cmax of 14.4±0.6 ng/mL was observed at 2.1±0.2 hours followed by subtherapeutic concentration beyond 30±0.2 hours, while after pulmonary administration of LP1, LP2, and LP3 formulations, Cmax of 4.4±0.4 ng/mL, 4.2±0.5 ng/mL, and 4.4±0.6 ng/ML were observed at 6.0±0.2 hours, 7.0±0.2 hours, and 6.8±0.2 hours, respectively, followed by maintenance of effective plasma drug concentration up to 60±2 hours. These studies demonstrate superiority of pulmonary drug delivery with regards to maintenance of effective therapeutic concentration of the LN in the plasma over a period of 6 to 60 hours. Hence, the pulmonary delivery is expected to reduce frequency of dosing and systemic side effects associated with oral administration of LN