86 research outputs found

    Liquid crystal thermography for the thermal analysis of gas turbine blades internal cooling systems

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    The present work focus on the analysis of the transient liquid crystal thermography, which is employed to accomplish spatially resolved heat transfer performance on cooling channel of gas turbine blades. This methodology has already been implemented to its early stage in the rotating channel test facility of the Turbomachinery and Energy Systems Laboratory of the University of Udine; however, several aspects are still unsettled. Therefore, the main objectives of this thesis is to address the accuracy and validation of the transient thermography technique with the particular approach developed at the University of Udine. With these aims, transient thermography tests are carried out in a ribbed cooling channel on both static and rotating conditions. Even if a very common channel geometry has been chosen as a study case, no reliable experimental data were found in the open literature for validation purposes. In order to overcome this lack, the heat transfer data necessary to perform the comparison are achieved with the better-established liquid crystal thermography in steady-state approach. This work addresses further development and improvement of the test facility to make possible the implementation of the steady-state methodology. Moreover, a complex iterative numerical procedure is set up to estimate the heat losses that are the major cause of the lack of accuracy in the steady-state thermography measurements. Part of the work was also dedicated to the definition of the best calibration methodology to take when liquid crystals are exploited as temperature indicators in transient thermography; especially, when liquid crystals with activation temperatures below ambient one are used, as in the present case. The results clearly show that the temperature evolution approach must be preferred to the previously used calibration method (gradient temperature approach). The results for all the rotation conditions provided by the two experimental approaches are in good agreement, representing the evidence of the validation of the transient thermography. Nevertheless, this work suggests a possible method to estimate the uncertainty of the heat transfer coefficient values in transient experimental approach, and this is done by a sensitivity analysis to the variation of the most important experimental parameters. Furthermore, the influence of two uneven channel wall heating conditions on the local heat transfer distribution is investigated by means of the steady-state technique. The results show that the uneven thermal conditions have negligible impact on the stationary case, but they significantly affect the heat transfer when the rotation takes place. This can be due to the different buoyancy effects that in turns affects the secondary flow structures, and consequently, the local heat transfer. Anyway, additional investigations are required to better understand the reasons why of this behaviour

    The small molecule ephrin receptor inhibitor, GLPG1790, Reduces renewal capabilities of cancer stem cells, showing anti-tumour efficacy on preclinical glioblastoma models

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    Therapies against glioblastoma (GBM) show a high percentage of failure associated with the survival of glioma stem cells (GSCs) that repopulate treated tumours. Forced differentiation of GSCs is a promising new approach in cancer treatment. Erythropoietin-producing hepatocellular (Eph) receptors drive tumourigenicity and stemness in GBM. We tested GLPG1790, a first small molecule with inhibition activity versus inhibitor of various Eph receptor kinases, in preclinical GBM models using in vitro and in vivo assays. GLPG1790 rapidly and persistently inhibited Ephrin-A1-mediated phosphorylation of Tyr588 and Ser897, completely blocking EphA2 receptor signalling. Similarly, this compound blocks the ephrin B2-mediated EphA3 and EphB4 tyrosine phosphorylation. This resulted in anti-glioma effects. GLPG1790 down-modulated the expression of mesenchymal markers CD44, Sox2, nestin, octamer-binding transcription factor 3/4 (Oct3/4), Nanog, CD90, and CD105, and up-regulated that of glial fibrillary acidic protein (GFAP) and pro-neural/neuronal markers, βIII tubulin, and neurofilaments. GLPG1790 reduced tumour growth in vivo. These effects were larger compared to radiation therapy (RT; U251 and T98G xenografts) and smaller than those of temozolomide (TMZ; U251 and U87MG cell models). By contrast, GLPG1790 showed effects that were higher than Radiotherapy (RT) and similar to Temozolomide (TMZ) in orthotopic U87MG and CSCs-5 models in terms of disease-free survival (DFS) and overall survival (OS). Further experiments were necessary to study possible interactions with radio- and chemotherapy. GLPG1790 demonstrated anti-tumor effects regulating both the differentiative status of Glioma Initiating Cells (GICs) and the quality of tumor microenvironment, translating into efficacy in aggressive GBM mouse models. Significant common molecular targets to radio and chemo therapy supported the combination use of GLPG1790 in ameliorative antiglioma therapy

    High-efficiency all-solution-processed light-emitting diodes based on anisotropic colloidal heterostructures with polar polymer injecting layers

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    Colloidal quantum dots (QDs) are emerging as true candidates for light-emitting diodes with ultrasaturated colors. Here, we combine CdSe/CdS dot-in-rod hetero-structures and polar/polyelectrolytic conjugated polymers to demonstrate the first example of fully solution-based quantum dot light-emitting diodes (QD-LEDs) incorporating all-organic injection/transport layers with high brightness, very limited roll-off and external quantum efficiency as high as 6.1%, which is 20 times higher than the record QD-LEDs with all-solution processed organic interlayers and exceeds by over 200% QD-LEDs embedding vacuum-deposited organic molecules

    Gingival overgrowth caused by Olmesartan Medoxomil: Observational study

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    Objective: Olmesartan Medoxomil is a type 1 receptor antagonist an antagonist of type 1 receptor (AT1) of angiotensin II (A-II) that inhibits numerous actions of A-II in the renin-angiotensin-aldosterone system (RAAS). A-II is a significant and multifunctional peptide involved in the pathophysiology of blood hypertension and for this reason it represents the main target in several classes of drugs used to treat and control arterial hypertension, such as angiotensin converting enzyme inhibitors (ACE-i), angiotensin receptor blockers (ARB) and renin direct inhibitors. The aim of the study is to evaluate whether the two drugs that have as an active principle Olmesartan Medoxomil, with and without the diuretic hydrochlorothiazide, are able to determine gingival overgrowth. Study Design: 108 subjects were examined and divided into three groups: G1, subjects treated with Olmesartan Medoxomil and hydrochlorothiazide (n=60); G2, subjects received only Olmesartan Medoxomil (n=24); G3, control group without pharmacological therapies (n=24). The plaque index (IP) and the gingival overgrowth index (OI) were recorded, considering the vertical and horizontal components. Results: Vertical overgrowth averaged between 0.17 \ub1 0.15 (G3) and 0.34 \ub1 0.26 (G2) showing statistically significant differences (p <0.05) compared to the other groups. Horizontal overgrowth ranged from 0.18 \ub1 0.26 (G3) to 0.49 \ub1 0.35 (G2) showing statistically significant differences (p <0.05). Conclusions: antihypertensive agents as Olmesartan Medoxomil may result in mild gingival overgrowth in the upper and lower frontal dental elements not related to other etiological factors

    Anti Transglutaminase Antibodies Cause Ataxia in Mice

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    Background: Celiac disease (CD) is an autoimmune gastrointestinal disorder characterized by the presence of anti-transglutaminase 2 (TG2) and anti-gliadin antibodies. Amongst the neurological dysfunctions associated with CD, ataxia represents the most common one. Methods: We analyzed by immunohistochemistry, the anti-neural reactivity of the serum from 20 CD patients. To determine the role of anti-TG2 antibodies in ataxia, two anti-TG2 single chain variable fragments (scFv), isolated from a phage-display IgA antibody library, were characterized by immunohistochemistry and ELISA, and injected in mice to study their effects on motor coordination. We found that 75% of the CD patient population without evidence of neurological involvement, has circulating anti-neural IgA and/or IgG antibodies. Two anti-TG2 scFvs, cloned from one CD patient, stained blood vessels but only one reacted with neurons. This anti-TG2 antibody showed cross reactivity with the transglutaminase isozymes TG3 and TG6. Intraventricular injection of the anti-TG2 or the anti-TG2/3/6 cross-reactive scFv provoked transient, equally intensive ataxia in mice. Conclusion: The serum from CD patients contains anti-TG2, TG3 and TG6 antibodies that may potentially cause ataxia

    Antimicrobial treatment with the fixed-dose antibiotic combination RHB-104 for Mycobacterium avium subspecies paratuberculosis in Crohn\u2019s disease: pharmacological and clinical implications

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    Introduction: Crohn\u2019s disease (CD) is an inflammatory bowel disease of unknown etiology. However, increasing evidence suggests Mycobacterium avium subspecies paratuberculosis (MAP) as a putative causative agent: 1) MAP is the etiological agent of Johne\u2019s disease, a granulomatous enteritis affecting ruminants, which shares clinical and pathological features with CD; 2) MAP has been detected in tissues and blood samples from CD patients; 3) case reports have documented a favorable therapeutic response to anti-MAP antibiotics. Area covered: This review provides an appraisal of current information on MAP characteristics, diagnostic methodologies and emerging drug treatments. The authors focus on RHB-104, a novel oral formulation containing a fixed-dose combination of clarithromycin, clofazimine and rifabutin, endowed with synergistic inhibitory activity on MAP strains isolated from CD patients. Expert opinion: Based on encouraging in vitro data, RHB-104 has entered recently the clinical phase of its development, and is being investigated in a randomized, placebo-controlled phase III trial aimed at evaluating its efficacy and safety in CD. Provided that the overall clinical development will support the suitability of RHB-104 for inducing disease remission in CD patients with documented MAP infection, this novel antibiotic combination will likely take a relevant position in the therapeutic armamentarium for CD management

    TRAIL reduces impaired glucose tolerance and NAFLD in the high-fat diet-fed mouse

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    Recent studies suggest that a circulating protein called TRAIL (TNF-related apoptosis inducing ligand) may have an important role in the treatment of type 2 diabetes. It has been shown that TRAIL deficiency worsens diabetes and that TRAIL delivery, when it is given before disease onset, slows down its development. The present study aimed at evaluating whether TRAIL had the potential not only to prevent, but also to treat type 2 diabetes. Thirty male C57BL/6J mice were randomized to a standard or a high-fat diet (HFD). After 4 weeks of HFD, mice were further randomized to receive either placebo or TRAIL, which was delivered weekly for 8 weeks. Body weight, food intake, fasting glucose, and insulin were measured at baseline and every 4 weeks. Tolerance tests were performed before drug randomization and at the end of the study. Tissues were collected for further analyses. Parallel in vitro studies were conducted on HepG2 cells and mouse primary hepatocytes. TRAIL significantly reduced body weight, adipocyte hypertrophy, free fatty acid levels, and inflammation. Moreover, it significantly improved impaired glucose tolerance, and ameliorated non-alcoholic fatty liver disease (NAFLD). TRAIL treatment reduced liver fat content by 47% in vivo as well as by 45% in HepG2 cells and by 39% in primary hepatocytes. This was associated with a significant increase in liver peroxisome proliferator-activated receptor (PPAR) \u3b3 (PPAR\u3b3) co-activator-1 \u3b1 (PGC-1\u3b1) expression both in vivo and in vitro, pointing to a direct protective effect of TRAIL on the liver. The present study confirms the ability of TRAIL to significantly attenuate diet-induced metabolic abnormalities, and it shows for the first time that TRAIL is effective also when administered after disease onset. In addition, our data shed light on TRAIL therapeutic potential not only against impaired glucose tolerance, but also against NAFLD

    Radiomics and artificial intelligence in prostate cancer: new tools for molecular hybrid imaging and theragnostics

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    In prostate cancer (PCa), the use of new radiopharmaceuticals has improved the accuracy of diagnosis and staging, refined surveillance strategies, and introduced specific and personalized radioreceptor therapies. Nuclear medicine, therefore, holds great promise for improving the quality of life of PCa patients, through managing and processing a vast amount of molecular imaging data and beyond, using a multi-omics approach and improving patients' risk-stratification for tailored medicine. Artificial intelligence (AI) and radiomics may allow clinicians to improve the overall efficiency and accuracy of using these "big data" in both the diagnostic and theragnostic field: from technical aspects (such as semi-automatization of tumor segmentation, image reconstruction, and interpretation) to clinical outcomes, improving a deeper understanding of the molecular environment of PCa, refining personalized treatment strategies, and increasing the ability to predict the outcome. This systematic review aims to describe the current literature on AI and radiomics applied to molecular imaging of prostate cancer
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