170 research outputs found

    Evaluation of daylighting performance in a retrofitted building facade

    Get PDF
    ThispaperanalysestwomainrenovationsofaUniversitybuildingfaçaderetrofitfromtheviewpoint ofannualdaylightingimprovement.Currently, thisbuildingconsistsofsome teaching roomsconnectedbya hallbutitisexpected that thisarrangementwillchangeinorder toaccommodate twoopen-planspaces for architecturestudents.TherenovateddesignwillincreasetheheightoftheNorth-Eastwindowsandintroduce shading devices on the South-West facade. These renovations were explored to determine if the internal luminousconditionswillmaintainadequatelevels.Fivedegreesofvisualscreening(100,90,70,45and34%) and two slats positions (horizontal and vertical) wereevaluated inrelation to the building with no screens. Climate-baseddaylightmodelling (CBDM)wascarriedoutbyusingDiva-for-Grasshopper.Thestudyrevealed that effectiveness of convergence testing depends strongly on the choice of CBDM metrics employed as a diagnostic– animportantconsiderationwhenmodellinglighttransferthroughlouvres.Resultsrecommended using louvred panels with no more than 70% of visual screening as higher percentages decrease useful illuminances over the range 300-3000 lux (UDI-a), to less than 50% of the occupancy time. Furthermore, verticallouvreswerebettersuitedtoincreaseUDI-athanhorizontalslats

    Inter-model comparison of five climate-based daylight modelling techniques: redirecting glazing/shading systems

    Get PDF
    The evolution of building facades towards increasingly smarter and more complex fenestration systems required an evolution in simulation capabilities too. While simulation software can reliably reproduce the system’s optical behaviour, the climate-based daylight evaluation of entire buildings needs to efficiently combine accuracy and computation speed. Five state-of-the-art Climate-Based Daylight Modelling (CBDM) techniques to evaluate a space with fixed venetian blinds are compared with each others. Multiple options to apply these techniques are also considered. The use of annual metrics based on global illumination led to a good agreement between all methods, while evaluating only direct sunlight exposed some profound differences between simulation techniques

    IL-25 participates in keratinocyte-driven dermal matrix turnover and is reduced in systemic sclerosis epidermis

    Get PDF
    OBJECTIVES: Evidence shows that dysfunctional SSc keratinocytes contribute to fibrosis by altering dermal homeostasis. Whether IL-25, an IL-17 family member regulating many epidermal functions, takes part in skin fibrosis is unknown. Here we address the role of IL-25 in skin fibrosis. METHODS: The expression of IL-25 was evaluated by immunofluorescence and in situ hybridization in 10 SSc and seven healthy donor (HD) skin biopsies. Epidermal equivalents (EE) reconstituted by primary HD keratinocytes were used as a model to study transcriptomic changes induced by IL-25 in the epidermis. RNA expression profile in EEs was characterized by RNAseq. The conditioned medium (CM) from primary SSc and HD keratinocytes primed with IL-25 was used to stimulate fibroblasts. IL-6, IL-8, MMP-1, type-I collagen (Col-I), and fibronectin production by fibroblasts was assessed by ELISA. RESULTS: SSc epidermis expressed lower levels of IL-25 compared with HDs. In EEs, IL-25 regulated several molecular pathways related to wound healing and extracellular matrix remodelling. Compared with control CM, the CM from IL-25-primed keratinocytes enhanced the fibroblast production of MMP-1, IL-6 and IL-8, but not of Col-I nor fibronectin. However, IL-25 significantly reduced the production of Col-I when applied directly to fibroblasts. The activation of keratinocytes by IL-25 was receptor-dependent and evident after a very short incubation time (10 min), largely mediated by IL-1, suggesting enhanced and specific release of preformed mediators. CONCLUSIONS: These results show that IL-25 participates in skin homeostasis, and its decreased expression in SSc may contribute to skin fibrosis by favouring extracellular matrix deposition over degradation

    Progressive age-associated activation of JNK associates with conduction disruption in the aged atrium.

    Get PDF
    Connexin43 (Cx43) is critical for maintaining electrical conduction across atrial muscle. During progressive aging cardiac conduction slows and becomes susceptible to disruption, predisposing to arrhythmias. Changes in Cx43 protein expression, or its phosphorylation status, can instigate changes in the conduction of the cardiac action potential. Our study investigated whether increased levels of activated c-jun N-terminal kinase (JNK) is the mechanism responsible for the decline of Cx43 protein and intercellular communication during progressive aging. We examined right atrial muscle from guinea pigs between 1 day and 38 months of age. The area of the intercalated disc increased with age concurrent with a 75% decline in total C43 protein expression and spatial re-organisation of the remaining protein. An age-dependent increase in activated-JNK correlated with a rise in phosphorylated Cx43. The data also correlated with slowing of the action potential conduction velocity across the right atria from 0.38±0.01 m/s at 1 month of age to 0.30±0.01 m/s at 38 months of age. The JNK activator anisomycin increased levels of activated JNK in myocytes and reduced Cx43 protein expression paralleling the aging effect The JNK inhibitor SP600125, was found to eradicate almost all trace of Cx43 protein from the intercalating discs. We conclude that in vivo activation of JNK increases with age leading to the loss of Cx43 protein from atrial myocytes. This progressive loss results in impaired conduction and is likely to contribute to the increasing risk of atrial arrhythmias with advancing age

    Quantification of Prostate Cancer Metabolism Using 3D Multiecho bSSFP and Hyperpolarized [1-13 C] Pyruvate: Metabolism Differs Between Tumors of the Same Gleason Grade

    Get PDF
    BACKGROUND: Three-dimensional (3D) multiecho balanced steady-state free precession (ME-bSSFP) has previously been demonstrated in preclinical hyperpolarized (HP) 13 C-MRI in vivo experiments, and it may be suitable for clinical metabolic imaging of prostate cancer (PCa). PURPOSE: To validate a signal simulation framework for the use of sequence parameter optimization. To demonstrate the feasibility of ME-bSSFP for HP 13 C-MRI in patients. To evaluate the metabolism in PCa measured by ME-bSSFP. STUDY TYPE: Retrospective single-center cohort study. PHANTOMS/POPULATION: Phantoms containing aqueous solutions of [1-13 C] lactate (2.3 M) and [13 C] urea (8 M). Eight patients (mean age 67 ± 6 years) with biopsy-confirmed Gleason 3 + 4 (n = 7) and 4 + 3 (n = 1) PCa. FIELD STRENGTH/SEQUENCES: 1 H MRI at 3 T with T2 -weighted turbo spin-echo sequence used for spatial localization and spoiled dual gradient-echo sequence used for B0 -field measurement. ME-bSSFP sequence for 13 C MR spectroscopic imaging with retrospective multipoint IDEAL metabolite separation. ASSESSMENT: The primary endpoint was the analysis of pyruvate-to-lactate conversion in PCa and healthy prostate regions of interest (ROIs) using model-free area under the curve (AUC) ratios and a one-directional kinetic model (kP ). The secondary objectives were to investigate the correlation between simulated and experimental ME-bSSFP metabolite signals for HP 13 C-MRI parameter optimization. STATISTICAL TESTS: Pearson correlation coefficients with 95% confidence intervals and paired t-tests. The level of statistical significance was set at P  0.96). Therefore, the simulation framework was used for sequence optimization. Whole prostate metabolic HP 13 C-MRI, observing the conversion of pyruvate into lactate, with a temporal resolution of 6 seconds was demonstrated using ME-bSSFP. Both assessed metrics resulted in significant differences between PCa (mean ± SD) (AUC = 0.33 ± 012, kP  = 0.038 ± 0.014) and healthy (AUC = 0.15 ± 0.10, kP  = 0.011 ± 0.007) ROIs. DATA CONCLUSION: Metabolic HP 13 C-MRI in the prostate using ME-bSSFP allows for differentiation between aggressive PCa and healthy tissue. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 1

    In Vivo Dioxin Favors Interleukin-22 Production by Human CD4+ T Cells in an Aryl Hydrocarbon Receptor (AhR)-Dependent Manner

    Get PDF
    The transcription factor aryl hydrocarbon receptor (AhR) mediates the effects of a group of chemicals known as dioxins, ubiquitously present in our environment. However, it is poorly known how the in vivo exposure to these chemicals affects in humans the adaptive immune response. We therefore assessed the functional phenotype of T cells from an individual who developed a severe cutaneous and systemic syndrome after having been exposed to an extremely high dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).T cells of the TCDD-exposed individual were studied for their capacity to produce cytokines in response to polyclonal and superantigenic stimulation, and for the expression of chemokine receptors involved in skin homing. The supernatants from T cells of the exposed individual contained a substantially increased amount of interleukin (IL)-22 but not of IL-17A, interferon (IFN)-γ or IL-10 when compared to nine healthy controls. In vitro experiments confirmed a direct, AhR-dependent, enhancing effect of TCDD on IL-22 production by CD4+ T cells. The increased production of IL-22 was not dependent on AhR occupancy by residual TCDD molecules, as demonstrated in competition experiments with the specific AhR antagonist CH-223191. In contrast, it was due to an increased frequency of IL-22 single producing cells accompanied by an increased percentage of cells expressing the skin-homing chemokine receptors CCR6 and CCR4, identified through a multiparameter flow cytometry approach. Of interest, the frequency of CD4+CD25(hi)FoxP3+ T regulatory cells was similar in the TCDD-exposed and healthy individuals.This case strongly supports the contention that human exposure to persistent AhR ligands in vivo induce a long-lasting effect on the human adaptive immune system and specifically polarizes CD4+ T cells to produce IL-22 and not other T cell cytokines with no effect on T regulatory cells

    MIF Participates in Toxoplasma gondii-Induced Pathology Following Oral Infection

    Get PDF
    BACKGROUND: Macrophage migration inhibitory factor (MIF) is essential for controlling parasite burden and survival in a model of systemic Toxoplasma gondii infection. Peroral T. gondii infection induces small intestine necrosis and death in susceptible hosts, and in many aspects resembles inflammatory bowel disease (IBD). Considering the critical role of MIF in the pathogenesis of IBD, we hypothesized that MIF participates in the inflammatory response induced by oral infection with T. gondii. METHODOLOGY/PRINCIPAL FINDINGS: Mif deficient (Mif(-/-)) and wild-type mice in the C57Bl/6 background were orally infected with T. gondii strain ME49. Mif(-/-) mice had reduced lethality, ileal inflammation and tissue damage despite of an increased intestinal parasite load compared to wt mice. Lack of MIF caused a reduction of TNF-α, IL-12, IFN-γ and IL-23 and an increased expression of IL-22 in ileal mucosa. Moreover, suppressed pro-inflammatory responses at the ileal mucosa observed in Mif(-/-) mice was not due to upregulation of IL-4, IL-10 or TGF-β. MIF also affected the expression of matrix metalloproteinase-9 (MMP-9) but not MMP-2 in the intestine of infected mice. Signs of systemic inflammation including the increased concentrations of inflammatory cytokines in the plasma and liver damage were less pronounced in Mif(-/-) mice compared to wild-type mice. CONCLUSION/SIGNIFICANCE: In conclusion, our data suggested that in susceptible hosts MIF controls T. gondii infection with the cost of increasing local and systemic inflammation, tissue damage and death

    Arrhythmias in Dilated Cardiomyopathy: Diagnosis and Treatment

    Get PDF
    In patients with dilated cardiomyopathy (DCM), it is possible to find a broad range of bradyrhythmias and tachyarrhythmias. Bradyrhythmias and supraventricular arrhythmias can frequently occur in some familial forms such as lamin A/C mutations. Nonsustained ventricular arrhythmias (VA) are observed in about 40% of patients with DCM, but their prognostic role is not clear, and conflicting data have been published in the last 30 years. Multiple mechanisms can explain atrial and ventricular tachyarrhythmias in DCM. Reentry is associated with slow conduction across surviving muscle bundles within regions of interstitial fibrosis, but other mechanisms can be involved, as nonuniform anisotropy of impulse propagation, ion channel dysfunction, and reduced gap junction function

    Reading Contemporary Serial Television Universes: A Narrative Ecosystem Framework

    No full text
    Reading Contemporary Serial Television Universes provides a new framework – the metaphor of the narrative ecosystem – for the analysis of serial television narratives. Contributors use this metaphor to address the ever-expanding and evolving structure of narratives far beyond their usual spatial and temporal borders, in general and in reference to specific series. Other scholarly approaches consider each narrative as composed of modular elements, which combine to create a bigger picture. The narrative ecosystem approach, on the other hand, argues that each portion of the narrative world contains all of the main elements that characterize the world as a whole, such as narrative tensions, production structures, creative dynamics and functions. The volume details the implications of the narrative ecosystem for narrative theory and the study of seriality, audiences and fandoms, production, and the analysis of the products themselves
    corecore