3,517 research outputs found
Growth factors and experimental arterial grafts
Background: The production of growth factors from several experimental arterial conduits was determined.
Methods: We implanted 105 experimental arterial grafts that were 1 cm long in the abdominal aorta of Lewis rats (average
weight, 250 g). Five different types of grafts were analyzed: arterial isografts, vein grafts, arterial allografts, and polytetrafluoroethylene
(PTFE) grafts with normal or decreased compliance. Animals were killed humanely 4 weeks after
surgery and the production of platelet-derived growth factor (PDGF), basic fibroblast growth factor (bFGF), transforming
growth factor-b, tumor necrosis factor-a, and interleukin-1 was analyzed.
Results: Myointimal hyperplasia (MH) was evident in vein grafts, arterial allografts, and PTFE grafts, but not in arterial
isografts. Growth factor production was increased for grafts prone to develop MH like vein, PTFE grafts, and arterial
allografts. PDGF and bFGF were increased significantly for PTFE and vein grafts, but not for arterial allografts. The
importance of bFGF and PGDF was confirmed by the capability of antibody to PDGF and to bFGF to reduce the
mitogenic activity of smooth muscle cells, in vivo and in vitro, for PTFE and vein grafts, but not for arterial allografts, in
which a predominant role was played by interleukin-1 and tumor necrosis factor-a.
Conclusions: Agents able to neutralize this increased production of growth factors, either directly or by competition with
their receptors, can prevent MH formation. (J Vasc Surg 2016;64:1444-9.)
Clinical Relevance: Arterial grafts release growth factors, which can lead to myointimal hyperplasia formation and
atherosclerosis progression in the arterial tree. Both phenomena can cause graft occlusion. Inhibition of growth factor release by arterial grafts can improve their clinical effectiveness
Effects of Dried Blood Spot Storage on Lipidomic Analysis
During the lipidomic analysis of red blood cell membranes, the distribution and percentage
ratios of the fatty acids are measured. Since fatty acids are the key constituents of cell membranes,
by evaluating their quantities it possible to understand the general health of the cells and to obtain
health indicators of the whole organism. However, because the analysis is precise, it is necessary to
ensure that the blood does not undergo significant variations between the point of collection and
analysis. The composition of the blood may vary dramatically weeks after collection, hence, here an
attempt is made to stabilize these complex matrixes using antioxidants deposited on the paper cards
on which the blood itself is deposited
Scavenging Effect of Various Extracts of the Gymnema sylvestre R. Br. and Antioxidant Activity of the Isolated Triterpenes
Gymnema sylvestre has been used in Asian traditional medicine for its anti-microbial, antihypercholesterolemic, hepatoprotective and sweet suppressing properties and activities. G. sylvestre has also been used extensively in chewing gum, as a health food for preventing obesity and diabetes, and as a tea. This study has evaluated the total phenolic content and antioxidant activity of the aqueous and organic G. sylvestre extracts and their sub-fractions for the initial characterization of the biological properties of the isolated compounds. An in vivo cell model was used to calculate the concentration inhibiting cell growth by 50% and the ability to exert antioxidant activity. All compounds inhibit cell growth in a dose-dependent manner, with an IC50 value ranging between 29 and 1462 μM. The effects on intracellular ROS levels are extremely variable, but it is of interest that some of the compounds appear to display an antioxidant effect
Web interactive non intrusive load disaggregation system for active demand in smart grids
A Smart Grid combines the use of traditional technology with innovative digital solutions, making the management of the electricity grid more flexible. It allows for monitoring, analysis, control and communication within the supply chain to improve efficiency, reduce the energy consumption and cost, and maximize the transparency and reliability of the energy supply chain. The optimization of energy consumption in Smart Grids is possible by using an innovative system based on Non Intrusive Appliance Load Monitoring (NIALM) algorithms, in which individual appliance power consumption information is disaggregated from single-point measurements, that provide a feedback in such a way to make energy more visible and more amenable to understanding and control. We contribute with an approach for monitoring consumption of electric power in households based on both a NILM algorithm, that uses a simple load signatures, and a web interactive systems that allows an active role played by users
Magnetic resonance imaging 3t and total fibrotic volume in autosomal dominant polycystic kidney disease
INTRODUCTION:
Autosomal dominant polycystic kidney disease (ADPKD) is the most common renal hereditary disorder. Several authors have attempted to identify a kidney damage marker for predicting the prognosis and the effectiveness of therapy in ADPKD. The aim of this study was to identify and quantify in ADPKD, through a novel MR protocol with 3 Tesla (MRI 3Tesla), the presence of parenchymal fibrotic tissue at early stage of disease, able to correlate the glomerular filtrate and to predict the loss of the function renal.
MATERIAL AND METHODS:
15 ADPKD patients undergone to renal MRI 3Tesla at T0 and revaluated after follow up (T1) of 5 years. We have evaluated renal function, plasma aldosterone concentration (PAC), insulin resistance and surrogate markers of atherosclerosis (carotid intima media thickness (IMT), ankle/brachial index (ABI) and left ventricular mass index (LVMI).
RESULTS:
Our study showed a significant negative correlation between total kidney volume and estimated glomerular filtration rate (eGFR) during observational observation (p<0.02). Moreover, we showed a negative correlation between eGFR with Total Fibrotic Volume (TFV) (p<0.04) and Total Perfusion Volume/Total kidney Volume(<0.02). Moreover TFV was correlated positively with PAC (p<0.05), insulin values (p<0.05), ABI (p <0.05) and LVMI(p<0.01).
CONCLUSIONS:
The MRI 3Tesla, despite the high costs, could be considered an useful and non-invasive method in the evaluation of fibrotic tissue and progression of the disease in ADPKD patients. Further clinical trials on larger group are due to confirm the results of this pilot study, suggesting that MRI 3Tesla can be useful to evaluate the effectiveness of new therapeutic strategies. This article is protected by copyright. All rights reserved
The Performance of Distributed Applications: A Traffic Shaping Perspective
Widely used in datacenters and clouds, network traffic shaping is a performance influencing factor that is often overlooked when benchmarking or simply deploying distributed applications. While in theory traffic shaping should allow for a fairer sharing of network resources, in practice it also introduces new problems: performance (measurement) inconsistency and long tails. In this paper we investigate the effects of traffic shaping mechanisms on common distributed applications. We characterize the performance of a distributed key-value store, big data workloads, and high-performance computing under state-of-the-art benchmarks, while the underlying network's traffic is shaped using state-of-the-art mechanisms such as token-buckets or priority queues. Our results show that the impact of traffic shaping needs to be taken into account when benchmarking or deploying distributed applications. To help researchers, practitioners, and application developers we uncover several practical implications and make recommendations on how certain applications are to be deployed so that performance is least impacted by the shaping protocols
El nuevo comercio digital : Mercado libre
Trabajo Final de Práctica ProfesionalEn un mundo en el que Internet ya no es un fenómeno nuevo, pero si un invento que revolucionó el mundo tal y como se lo conocÃa hace 30 años, las empresas... ¿supieron hacer frente a este cambio?. La era digital en la que la sociedad se encuentra inmersa, es la precursora de una nueva forma de comercio, en la que Internet cobra una importancia significativa. Dar la espalda al universo online, puede suponer no tener acceso a una gran cantidad de clientes. Las plataformas de compra-venta permiten dar soluciones a las empresas grandes, Pymes y comerciantes para utilizar las herramientas que Internet brinda. Funcionan como intermediarias entre el comprador y el vendedor, y permiten que los tres eslabones logren su cometido, el cliente obtiene el producto, el vendedor realiza la venta, y la plataforma se reditúa de la transacción. Las nuevas generaciones prefieren esta modalidad de comercio, debido a la dependencia que tienen con el celular, las tabletas o las computadoras, que se las utiliza como medio de comunicación, de distracción y de búsqueda de información. Se agiliza el proceso, porque la persona no tiene que dirigirse a un establecimiento de compra. ¿Son estas plataformas la nueva forma de comercio? ¿Resultan más beneficiosas que las maneras tradicionales? ¿Estas compañÃas, y en especial Mercado Libre, controlan el mercado? El objetivo del trabajo es abordar estos temas, y desarrollar en profundidad la importancia del Marketing Digital, y en especial la empresa Mercado Libre en la actualidad con sus innovaciones.Fil: De Piero, Valeria. Universidad Nacional de San MartÃn. Escuela de EconomÃa y NegociosFil: Di Marco, MarÃa Julieta. Universidad Nacional de San MartÃn. Escuela de EconomÃa y Negocio
Effect of pore modulating additives-sepiolite and colloidal nano silica-on physical, mechanical and durability properties of lime-based renders
Does the Element Availability Change in Soils Exposed to Bioplastics and Plastics for Six Months?
Plastic sheets are widely used in farming soil to improve the productivity of cultures. Due to their absorption capacity, plastic sheets can alter element and metal content in soils, and in turn affect soil properties. The use of biodegradable films is an attractive eco-sustainable alternative approach to overcome the environmental pollution problems due to the use of plastic films but their impacts on soil are scarcely studied. The aim of the research was to evaluate the impact of conventional plastic and bioplastic sheets on total and available concentrations of elements (Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn) in soils. The research was performed in mesocosm trials, filled with soil covered by conventional plastic and bioplastic sheets. After six months of exposure, soils were characterized for pH, water content, concentrations of organic and total carbon and total nitrogen, and total and available Al, Ca, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn element concentrations. The results highlighted that soils covered by bioplastic sheets showed higher total and available concentrations of elements and higher contamination factors, suggesting that bioplastic sheets represented a source of metals or a less-effective sink to these background metals in soils, compared to conventional plastic ones
- …