Search results for "plastic"
showing 10 items of 7296 documents
Unveiling adaptive mechanisms though experimental evolution: the role of duplicated genes and phenotypic plasticity in yeast, and the genetic variabi…
2021
Los seres vivos se enfrentan a condiciones ambientales cambiantes y habitualmente estresantes, agravadas por el cambio climático, que ponen a prueba su capacidad de supervivencia. El cambio en la composición genética de las poblaciones reside en las mutaciones, que son la fuente para la evolución y la adaptación a los cambios. La diversidad genética intrapoblacional está regulada por dos grandes fuerzas evolutivas que cambian la composición genética permitiendo así el acceso a nuevos fenotipos: la deriva genética y la selección natural. Por un lado, la deriva genética fija mutaciones en la población de manera aleatoria e independiente del efecto que suponga dicha mutación para la población.…
Growing Like Germany: Local Public Debt, Local Banks, Low Private Investment
2021
The paper uses a panel of more than 1m German firms over 2010-2016, to provide the first firm-bank level evidence of local crowding out for a developed economy characterized by low interest rates and fiscal austerity. Our mechanism relies on two structural features of Germany's banking landscape: the local segmentation of credit markets for small and medium-sized firms (SME) and the role of local public banks in local public finance. Local public banks dominate lending to small and medium firms in Germany and also have an explicit mandate to lend to the local public sector. With spreads on local government debt at all-time lows, local public banks tried to break even, using their market pow…
A computational framework for microstructural modelling of polycrystalline materials with damage and failure
2017
In the present thesis, a computational framework for the analysis of the deformation and damage phenomena occurring at the scale of the constituent grains of polycrystalline materials is presented. The research falls within the area of Computational Micro-mechanics that has been attracting remarkable technological interest due to the capability of explaining the link between the micro-structural details of heterogenous materials and their macroscopic response, and the possibility of fine-tuning the macroscopic properties of engineered components through the manipulation of their micro-structure. However, despite the significant developments in the field of materials characterisation and the…
Cytokines gene expression in the tunica albuginea in patients with Peyronie’s disease. Pilot study with a control group
2011
INTRODUCTION: We decided to conduct a study to investigate the presence of cytokines in the albuginea of subjects with Peyronie's disease (PD). Cytokines, as responsible for intercellular communication, maybe involved in the pathogenesis of the disease. The identification of one or more involved cytokines may, in fact, be useful in the pharmacological treatment with biologic drugs that are able to interfere with specific cytokines. MATERIALS AND METHODS: Between January 2009 and Decembre 2010 at the Clinic of Urological outpatients clinic of the Policlinico of Palermo were recruited 20 subjects with PD, mean age 62.3 years (range 51-70) and 8 subjects with congenital recurvatum penis (mean …
Synthesis and characterization of ethylene-1-hexene copolymers prepared by using MgCl2(THF)2-supported Ziegler-Natta catalysts
2000
Ethylene was copolymerized with 1-hexene over vanadium (VOCl3 and VCl4) and titanium (TiCl4) catalysts supported on MgCl2(THF)2 and activated with Et2AlCl. So far these catalyst systems have not been known as initiators of ethylene-1-hexene copolymerization. The vanadium catalysts were more active than the titanium catalyst and, at identical comonomer concentrations in the feed, gave rise to a greater incorporation of 1-hexene into the copolymer. Even at relatively low fractions of 1-hexene, the MgCl2(THF)2-supported catalysts affected much the copolymer properties like density, melting point and crystallinity.
Neuronal structural plasticity in the Medial Prefrontal Cortex: regulation by Dopamine and PSA-NCAM
2011
Although there is a decline in brain plasticity across lifespan, neurons in certain areas of the adult brain retain the ability to undergo synaptic, dendritic and spine remodeling in response to different stimuli. This neuronal structural plasticity seems to be the basis for many cognitive processes and it is crucial for adaptive responses to aversive experiences and recovery from brain damage and disease. Among the numerous candidate molecules that have been identified for mediating this neuronal remodeling, cell adhesion molecules and, specially, the neural cell adhesion molecule (NCAM), are of particular interest. The addition of polysialic acid (PSA) to the NCAM is critical for the stru…
Polytetrafluoroethylene Films in Rigid Polyurethane Foams' Dielectric Permittivity Measurements with a One-Side Access Capacitive Sensor.
2021
As a non-metallic composite material, widely applied in industry, rigid polyurethane (PUR) foams require knowledge of their dielectric properties. In experimental determination of PUR foams’ dielectric properties protection of one-side capacitive sensor’s active area from adverse effects caused by the PUR foams’ test objects has to be ensured. In the given study, the impact of polytetrafluoroethylene (PTFE) films, thickness 0.20 mm and 0.04 mm, in covering or simulated coating the active area of one-side access capacitive sensor’ electrodes on the experimentally determined true dielectric permittivity spectra of rigid PUR foams is estimated. Penetration depth of the low frequency excitation…
Review of photoelastic image analysis applied to structural birefringent materials: glass and polymers
2015
Photoelasticity is particularly suitable for the analysis of the stress state in structural materials that are transparent and birefringent. Some techniques of digital photoelasticity (phase shifting and RGB) are applied to the analysis of stress field in two classes of structural materials. The first one consists of tempered glasses, such as those used in the automotive and architectural fields. The second one consists of thermoset polymers, typically used as matrices in fiber reinforced plastic structural composites. The birefringence of such resins is, in particular, exploited to investigate the development of swelling stresses and changes in fracture toughness as induced by water uptake…
Targeting DNA double strand break repair with hyperthermia and DNA-PKcs inhibition to enhance the effect of radiation treatment
2016
// Bregje van Oorschot 1 , Giovanna Granata 1 , Simone Di Franco 2 , Rosemarie ten Cate 1 , Hans M. Rodermond 1 , Matilde Todaro 3 , Jan Paul Medema 1 , Nicolaas A.P. Franken 1 1 Laboratory for Experimental Oncology and Radiobiology (LEXOR), Center for Experimental Molecular Medicine, Department of Radiation Oncology, Academic Medical Center, Cancer Genomics Center, Amsterdam, The Netherlands 2 Department of Surgical, Oncological and Stomatological Sciences (DICHIRONS), Cellular and Molecular Pathophysiology Laboratory, University of Palermo, Palermo, Italy 3 Biomedical Department of Internal and Specialistic Medicine (DIBIMIS), University of Palermo, Palermo, Italy Correspondence to: Nicol…
Data from an international multi-centre Study of Statistics and Mathematics Anxieties and Related Variables in University Students (the SMARVUS Datas…
2023
This large, international dataset contains survey responses from N = 12,570 students from 100 universities in 35 countries, collected in 21 languages. We measured anxieties (statistics, mathematics, test, trait, social interaction, performance, creativity, intolerance of uncertainty, and fear of negative evaluation), self-efficacy, persistence, and the cognitive reflection test, and collected demographics, previous mathematics grades, self-reported and official statistics grades, and statistics module details. Data reuse potential is broad, including testing links between anxieties and statistics/mathematics education factors, and examining instruments’ psychometric properties across differ…