318 research outputs found

    Noise reduction performance of thermobonded nonwovens

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    Acoustic insulation is an important requirement for the human life today, since noise affects the efficiency of day-to-day activities and even cause various health problems Materials based on fibrous structures show very good acoustic insulation properties, which however strongly depends on the type of structures used. The present paper reports the qualitative analysis of the acoustic insulation behavior of various thermo-bonded nonwoven fabrics. The results showed that the acoustic insulation of thermo-bonded nonwovens improves with their thickness. Also, nonwovens laminated with aluminum foil exhibited better sound reduction performance than other single layered nonwovens made from recycled fibres and even better performance than the nonwovens made from mineral wool, in the frequency range perceptible by human air

    Caloric restriction rescues yeast cells from alpha-synuclein toxicity through autophagic control of proteostasis

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    α-Synuclein (SNCA) is a presynaptic protein that is associated with the pathophysiology of synucleinopathies, including Parkinson's disease. SNCA is a naturally aggregation-prone protein, which may be degraded by the ubiquitin-proteasome system (UPS) and by lysosomal degradation pathways. Besides being a target of the proteolytic systems, SNCA can also alter the function of these pathways further, contributing to the progression of neurodegeneration. Deterioration of UPS and autophagy activities with aging further aggravates this toxic cycle. Caloric restriction (CR) is still the most effective non-genetic intervention promoting lifespan extension. It is known that CR-mediated lifespan extension is linked to the regulation of proteolytic systems, but the mechanisms underlying CR rescue of SNCA toxicity remain poorly understood. This study shows that CR balances UPS and autophagy activities during aging. CR enhances UPS activity, reversing the decline of the UPS activity promoted by SNCA, and keeps autophagy at homeostatic levels. Maintenance of autophagy at homeostatic levels appears to be relevant for UPS activity and for the mechanism underlying rescue of cells from SNCA-mediated toxicity by CR.BSM and HP are supported by fellowships from the Fundação para a Ciência e Tecnologia (FCT, Portugal) (SFRH/BPD/90533/2012 and SFRH/BD/133087/2017, respectively).info:eu-repo/semantics/publishedVersio

    Prevalence of articular cartilage lesions and surgical clinical outcomes in football (soccer) players' knees: a systematic review

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    "Article in Press" ; "Published Online: April 16, 2016"Purpose: To systematize the available scientific literature on the prevalence of articular cartilage and/or osteo- chondral lesions in football (soccer) playersâ knees, and overview the surgical procedures and functional outcomes and return to sports. Methods: A comprehensive search using Pubmed, Cochrane Library, SPORTDiscus, and CINAHL databases was carried out until September 30, 2015. All English language studies that assessed the outcomes of a surgical technique for the treatment of articular cartilage lesions in football playersâ knees, with a minimum follow-up of 12 months, were included. The reference list of the most relevant papers was screened. The main outcomes of interest were the clinical, arthroscopy or imaging primary outcomes and the return to sports rate. The methodological and reporting qualities were assessed according to Coleman methodology score. Results: The search provided 485 titles and abstracts. Five studies were eligible for inclusion (mean Coleman score of 37.2 points), comprising a total of 183 football players with a mean age of 25.7 years. A total of 217 articular cartilage and/or osteochondral lesions were reported, where the medial and lateral femoral condyles were the most common sites of lesion. The surgical procedures investigated were mosaicplasty, microfracture, autologous chondrocyte implantation, and chondral debridement. Conclusions: No definitive conclusion could be made in respect to the best current surgical technique for articular cartilage and osteochondral lesions. Microfracture and mosaicplasty can provide a faster return to competition and faster clinical and functional results, whereas autologous chondrocyte implantation and/or matrix-induced autologous chondrocytes implantation procedures can enhance longstanding clinical and functional results. Level of Evidence: Level IV, systematic review of Level III and IV studies

    A novel approach for micro-antenna fabrication on ZrO2 substrate assisted by laser printing for smart implants

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    The use of Yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) in medicine has rapidly expanded over the past decade, driven by its advantageous properties, showing potential to overcome titanium alloy in implant fabrication. The release of metal ions and the aesthetic problems of titanium alloy implants are the main reasons for this trend. In addition to meeting expectations regarding its properties, an implant must possess intrinsic capacities such as auto-diagnostic and auto-treatment. Thus, based on the concept of smart implants, this work proposes a hybrid approach for printing a part of the communication system of a zirconia implant by resorting to laser technology, aiming to endow the implant with intrinsic capacities. Therefore, the antenna was designed and then printed on the zirconia surface. The laser was applied as a versatile tool, whether for preparing the surface of the material in a subtractive way, by creating the micro-cavity, or for printing the silver-based antenna in an additive way through laser technology. The silver powder was used as the conductor material of the antenna. The results revealed that the antenna is capable of communicating from inside the body with the outside world without needing to have an exterior antenna attached to the skin.This work has been supported by the FCT (Fundação para a Ciência e Tecnologia -Portugal) in the scope of the projects UID/EEA/04436/2019; Magsense_POCI-01-0247-FEDER-033783, Add.Additive_Manufacturing to Portuguese Industry_POCI-01-0247-FEDER-024533, grant SFRH/BD/ 116554/2016 and the CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) for the grant 205791/2014-

    Altered bone microarchitecture in a type 1 diabetes mouse model Ins2 Akita

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    Type 1 diabetes mellitus (T1DM) has been associated to several cartilage and bone alterations including growth retardation, increased fracture risk, and bone loss. To determine the effect of long term diabetes on bone we used adult and aging Ins2(Akita) mice that developed T1DM around 3-4 weeks after birth. Both Ins2(Akita) and wild-type (WT) mice were analyzed at 4, 6, and 12 months to assess bone parameters such as femur length, growth plate thickness and number of mature and preapoptotic chondrocytes. In addition, bone microarchitecture of the cortical and trabecular regions was measured by microcomputed tomography and gene expression of Adamst-5, Col2, Igf1, Runx2, Acp5, and Oc was quantified by quantitative real-time polymerase chain reaction. Ins2(Akita) mice showed a decreased longitudinal growth of the femur that was related to decreased growth plate thickness, lower number of chondrocytes and to a higher number of preapoptotic cells. These changes were associated with higher expression of Adamst-5, suggesting higher cartilage degradation, and with low expression levels of Igf1 and Col2 that reflect the decreased growth ability of diabetic mice. Ins2(Akita) bone morphology was characterized by low cortical bone area (Ct.Ar) but higher trabecular bone volume (BV/TV) and expression analysis showed a downregulation of bone markers Acp5, Oc, and Runx2. Serum levels of insulin and leptin were found to be reduced at all-time points Ins2(Akita). We suggest that Ins2(Akita) mice bone phenotype is caused by lower bone formation and even lower bone resorption due to insulin deficiency and to a possible relation with low leptin signaling.F. R. Carvalho and S. M. Calado acknowledge the financial support from the Portuguese Foundation for Science and Technology (FCT) through Ph.D. fellowships SFRH/BD/76429/2011 and SFRH/BD/76873/2011, respectively. This study was funded in part by CCMAR funding from European Regional Development Fund (ERDF) under COMPETE Program and through FCT under PEst-C/MAR/LA0015/2011 project and through UID/Multi/04326/2013 project. GA Silva was funded by (PIRG05-GA-2009-249314-EyeSee) and Research Center Grant UID/BIM/04773/2013 to CBMR

    Arthroscopic repair of ankle instability with all-soft knotless anchors

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    In recent years, arthroscopic and arthroscopically assisted techniques have been increasingly used to reconstruct the lateral ligaments of the ankle. Besides permitting the treatment of several comorbidities, arthroscopic techniques are envisioned to lower the amount of surgical aggression and to improve the assessment of anatomic structures. We describe our surgical technique for arthroscopic, two-portal ankle ligament repair using an all-soft knotless anchor, which is made exclusively of suture material. This technique avoids the need for classic knot-tying methods. Thus it diminishes the chance of knot migration caused by pendulum movements. Moreover, it avoids some complications that have been related to the use of metallic anchors and some currently available biomaterials. It also prevents prominent knots, which have been described as a possible cause of secondary complaints.info:eu-repo/semantics/publishedVersio

    Genetic variants of vascular endothelial growth factor predict risk and survival of gliomas

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    The vascular endothelial growth factor regulates angiogenesis that is increased in glioma. VEGF polymorphisms are thought to modulate vascular endothelial growth factor plasma levels and therefore may be implicated in glioma risk. We aimed to clarify the role of VEGF and von Willebrand factor polymorphisms in glioma susceptibility and prognosis. A case-control study of 126 glioma patients and 180 cancer-free controls was performed. Using Sequenom MassARRAY platform, 11 VEGF and 1 VWF polymorphisms were genotyped. Unconditional multivariate logistic regression models were used to calculate odds ratios and 95% confidence intervals. The associations between polymorphisms and survival were evaluated using a Cox regression model. Bonferroni's adjustment was used to correct for multiple testing. The VEGF polymorphism rs833061 was strongly associated with increased risk for glioma (odds ratio = 164.85) and glioblastoma (odds ratio = 155.66), confirmed after Bonferroni correction. Also, the VEGF polymorphisms rs3024994, rs2010963, and particularly the homozygous carriers of rs1005230 were associated with a worse prognosis for glioma and glioblastoma. Our data support a role of VEGF and VWF polymorphisms as glioma biomarkers, with additional potential relevance for molecular stratification of patients for anti-angiogenic therapies.FCT -Fundação para a Ciência e a Tecnologia(NORTE-01-0145-FEDER-000013)info:eu-repo/semantics/publishedVersio

    Simple strategies for stable aqueous suspensions of carbon nanotubes

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    Carbon nanotubes (CNT) are attractive nanoparticles for biological applications due to their broad absorption of light in the UV-Vis-NIR, NIR photoluminescence, unique Raman signature, photothermal response, and large surface area for the covalent and non-covalent conjugation of contrast agents and drugs, DNA/RNA. However, pristine CNT are highly hydrophobic and not biocompatible, requiring functionalization with hydrophilic molecules in order to form stable aqueous suspensions. Here, simple functionalization methods of perylene bisimides and pyrene, to render these polyaromatic molecules amphiphilic, will be presented. Bolaamphiphilic perylene bisimides (PBI) were prepared by the reaction of perylenetetracarboxylic dianhydride with -amino acids in good yield, using a simple protocol and avoiding complex purification methods. [1] Pyrene was modified by nitration followed by amination, and further reacted with maleic anhydride yielding carboxylic acid-functionalized pyrene. The CNT aqueous suspensions were studied by absorption and emission spectroscopy. Theoretical calculations were used to support the experimental observations. The possibility of CNT double functionalization (covalent and non-covalent) will be discussed based on CNT solubility studies in surfactant aqueous solutions. Pristine and covalently functionalized CNT, at different functionalization yields, were compared. The CNT were functionalized by the 1,3-dipolar cycloaddition of azomethine ylides. [2] The ability of CNT to adsorb surfactant molecules was reduced by the covalent functionalization. Nevertheless, depending on the extent of covalent functionalization, a high concentration of CNT in water could be attained, in comparison to that of pristine CNT.Fundação para a Ciência e a Tecnologia (FCT

    Sewage sludge fertilization—A case study of Sweet Potato yield and heavy metal accumulation

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    Sewage sludge (SS) is derived from wastewater treatment plants and can be used as a biofertilizer when properly stabilized. This work aimed to evaluate SS application for agricultural production improvement. SS was tested on Porto Santo Island (Portugal). The experiment was randomly designed with three 25 m2 plots for each treatment (2 SS concentrations + control without SS) and performed in two consecutive cycles. For the first cycle, dehydrated sludge was mixed with soil, obtaining final concentrations of 0.8 kg/m2 (C1) and 1.6 kg/m2 (C2). Half of the concentration was used for the second cycle. Fifty-eight sweet potato plants were used in each plot. SS application boosted the agronomic parameters of biomass, productivity, and shoot biomass. Furthermore, improvements in soil properties were observed, mainly for pH, CEC, and NO3 -N, with no significant increase in heavy metals. For the edible parts, heavy metal concentrations decreased, and Pb was the only one that still exceeded the maximum limits. The results demonstrated that SS application to low-fertility soil is effective in improving the agronomic parameters of sweet potato and enhancing soil features. Further studies considering other variables, i.e., SS origin, soil properties, and the crop, must be carried out to propose custom applications.info:eu-repo/semantics/publishedVersio
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