1,136 research outputs found

    Simvastatin Alters the RhoA Adaptation to Skeletal Muscle Stress Conditions

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    Please refer to the pdf version of the abstract located adjacent to the title

    Topological Friction and Relaxation Dynamics of Spatially Confined Catenated Polymers

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    We study catenated ring polymers confined inside channels and slits with Langevin dynamics simulations and address how the contour position and size of the interlocked or physically linked region evolve with time. We show that the catenation constraints generate a drag, or topological friction, that couples the contour motion of the interlocked regions. Notably, the coupling strength decreases as the interlocking is made tighter, but also shorter, by confinement. Though the coupling strength differs for channel and slit confinement, the data outline a single universal curve when plotted against the size of the linked region. Finally, we study how the relaxation kinetics changes after one of the rings is cut open and conclude that considering interlocked circular polymers is key for isolating the manifestations of topological friction. The results ought to be relevant for linked biomolecules in experimental or biological confining conditions

    sheets impact simulation for safety guards design experiments and correlation for fe explicit models of non alloy steel

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    Abstract In the last few years, some international standards for the safety of machine tools have been developed improving the ballistic protection of safety guards. The uncontrolled projection of parts of work piece or tools can often cause very dangerous perforations of the safety guards. In such a way specific experimental tests like the ones conducted in EU, have assured the possibility to write appendices of ISO standards for safety guards design of machine tools. These tests are based on impact between a particular standardized projectile, which exemplifies an impacting fragment of variable size and energy, and a flat plate placed in the trajectory of the projectile. The penetration or buckling of the target determines the non-suitability of a particular material of a given thickness, for the design and production of safety guards. However, these tests have following limitations: they are valid only for: a limited type of thickness and materials, a perpendicular impact with flat plates of about 500 mm x 500 mm and when the standardized penetrator is a cylinder with a prismatic head. Another limitation is based on design of real safety guards: difficulties in taking into account curved design of guards such as the ones typically used in the spindles of machine tools. Moreover, it is very difficult to take into account innovative materials different from the ones provided by the standards. It is also impossible to consider projected objects whose geometry is not regular, for example fragmented parts of tools, broken as a result of a wrong manoeuvre of the machine user. The focus of this paper is to give an overview of possible material models usable for FEM explicit virtual testing of safety guards. Correlation between experimental penetration of international standards and numerical tests will be presented as a proof of the possibility to implement reliable testing virtual procedures. It is possible to think of exploring the uncertainty of the standardized tests procedure due to, as an example, non-perpendicular impact of the projectile on the safety guard, using simulations

    Perfil sócio-econômico dos alunos da creche Irmã Anísia Rocha da cidade de Sobral, CE no ano de 2005.

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    O estudo é parte do projeto "Manipulação de constituintes e prospecção de propriedades funcionais do leite de cabra" financiado pelo Macroprograma 2 da Embrapa e, liderado pela Embrapa Caprinos, que teve objetivo geral: Conhecer o efeito de estratégias nutricionais para manipulação do perfil de caseínas e de ácidos graxos do leite de cabra e seus impactos sobre a saúde humana na prospecção de propriedades funcionais. Além de conhecer melhor o aluno, trata-se de gerar subsídios para melhorar a qualidade do ensino e prestação de serviços pela Creche Irmã Anísia Rocha.bitstream/CNPC/20815/1/cot84.pd

    Theoretical model for the superconducting and magnetically ordered borocarbides

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    We present a theory of superconductivity in presence of a general magnetic structure in a form suitable for the description of complex magnetic phases encountered in borocarbides. The theory, complemented with some details of the band structure and with the magnetic phase diagram, may explain the nearly reentrant behaviour and the anisotropy of the upper critical field of HoNi2B2C. The onset of the helical magnetic order depresses superconductivity via the reduction of the interaction between phonons and electrons caused by the formation of magnetic Bloch states. At mean field level, no additional suppression of superconductivity is introduced by the incommensurability of the helical phase.Comment: 8 pages, 2 figures. Published version, one important reference adde

    DNA vaccines against ErbB2+ Carcinomas: From mice to humans.

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    DNA vaccination exploits a relatively simple and flexible technique to generate an immune response against microbial and tumor-associated antigens (TAAs). Its effectiveness is enhanced by the application of an electrical shock in the area of plasmid injection (electroporation). In our studies we exploited a sophisticated electroporation device approved for clinical use (Cliniporator, IGEA, Carpi, Italy). As the target antigen is an additional factor that dramatically modulates the efficacy of a vaccine, we selected ErbB2 receptor as a target since it is an ideal oncoantigen. It is overexpressed on the cell membrane by several carcinomas for which it plays an essential role in driving their progression. Most oncoantigens are self-tolerated molecules. To circumvent immune tolerance we generated two plasmids (RHuT and HuRT) coding for chimeric rat/human ErbB2 proteins. Their immunogenicity was compared in wild type mice naturally tolerant for mouse ErbB2, and in transgenic mice that are also tolerant for rat or human ErbB2. In several of these mice, RHuT and HuRT elicited a stronger anti-tumor response than plasmids coding for fully human or fully rat ErbB2. The ability of heterologous moiety to blunt immune tolerance could be exploited to elicit a significant immune response in patients. A clinical trial to delay the recurrence of ErbB2+ carcinomas of the oral cavity, oropharynx and hypopharynx is awaiting the approval of the Italian authorities

    Li+ Insertion in Nanostructured TiO2 for Energy Storage

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    Nanostructured materials possess unique physical-chemical characteristics and have attracted much attention, among others, in the field of energy conversion and storage devices, for the possibility to exploit both their bulk and surface properties, enabling enhanced electron and ion transport, fast diffusion of electrolytes, and consequently high efficiency in the electrochemical processes. In particular, titanium dioxide received great attention, both in the form of amorphous or crystalline material for these applications, due to the large variety of nanostructures in which it can be obtained. In this paper, a comparison of the performance of titanium dioxide prepared through the oxidation of Ti foils in hydrogen peroxide is reported. In particular, two thermal treatments have been compared. One, at 150 °C in Ar, which serves to remove the residual hydrogen peroxide, and the second, at 450 °C in air. The material, after the treatment at 150 °C, results to be not stoichiometric and amorphous, while the treatment at 450 °C provide TiO2 in the anatase form. It turns out that not-stoichiometric TiO2 results to be a highly stable material, being a promising candidate for applications as high power Li-ion batteries, while the anatase TiO2 shows lower cyclability, but it is still promising for energy-storage devices

    Insertion of the DNA for the 163-171 peptide of IL1beta enables a DNA vaccine encoding p185(neu) to inhibit mammary carcinogenesis in Her-2/neu transgenic BALB/c mice.

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    Insertion of the DNA for the 163–171 peptide of IL1β enables a DNA vaccine encoding p185 neu to inhibit mammary carcinogenesis in Her-2/neu transgenic BALB/c mic

    Waking and sleeping following water deprivation in the rat

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    Wake-sleep (W-S) states are affected by thermoregulation. In particular, REM sleep (REMS) is reduced in homeotherms under a thermal load, due to an impairment of hypothalamic regulation of body temperature. The aim of this work was to assess whether osmoregulation, which is regulated at a hypothalamic level, but, unlike thermoregulation, is maintained across the different W-S states, could influence W-S occurrence. Sprague-Dawley rats, kept at an ambient temperature of 24 \ub0C and under a 12 h:12 h light-dark cycle, were exposed to a prolonged osmotic challenge of three days of water deprivation (WD) and two days of recovery in which free access to water was restored. Two sets of parameters were determined in order to assess: i) the maintenance of osmotic homeostasis (water and food consumption; changes in body weight and fluid composition); ii) the effects of the osmotic challenge on behavioral states (hypothalamic temperature (Thy), motor activity, and W-S states). The first set of parameters changed in WD as expected and control levels were restored on the second day of recovery, with the exception of urinary Ca++ that almost disappeared in WD, and increased to a high level in recovery. As far as the second set is concerned, WD was characterized by the maintenance of the daily oscillation of Thy and by a decrease in activity during the dark periods. Changes in W-S states were small and mainly confined to the dark period: i) REMS slightly decreased at the end of WD and increased in recovery; ii) non-REM sleep (NREMS) increased in both WD and recovery, but EEG delta power, a sign of NREMS intensity, decreased in WD and increased in recovery. Our data suggest that osmoregulation interferes with the regulation of W-S states to a much lesser extent than thermoregulation

    Synthesis and application of isotope-labeled carnosine in LCMS/MS

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    Carnosine is an endogenous dipeptide, composed of \u3b2-alanine and L-histidine, and is highly concentrated in skeletal muscle and other excitable tissues. Its physiological roles, based on its biochemical properties, include pH-buffering, metal-ion chelation and antioxidant capacity as well as the ability to protect against the formation of advanced glycation and lipoxidation end-products.1 For these reasons, besides its nutritional ergogenic application in the sport community,2 carnosine supplementation offers a therapeutic potential for the treatment of numerous diseases in which ischemic or oxidative stress is involved.1 Quantitation of carnosine in biological matrices appears to be crucial for these applications, and LC-MS procedures with isotope-labeled internal standards are the state-of-the-art approach for this analytical need.3 The use of these standards allows to account for variations during the complex sample preparation process, different matrix effects between patient samples, and variations in instrument performance. Figure 1 In this work, we present a fast and highly efficient synthetic route to obtain a deuterated carnosine analogue (Figure 1) starting from the trideuterated L-histidine (\u3b1-d1, imidazole-2,5-d2). Moreover, the use of Carnosine-d3 in the validation of a multiple reaction monitoring (MRM) LC-MS/MS method for the analytical quantitation of carnosine in a biological matrix will be reported. References 1. Boldyrev, A. A.; Aldini, G.; Derave, W. Physiol. Rev. 2013, 93, 1803\u20131845. 2. Brisola, G.; Zagatto, A. J. Strength Cond. Res. 2019, 33, 253-282. 3. Stokvis, E.; Rosing, H.; L\uf3pez-L\ue1zaro, L.; Schellens, J. H. M.; Beijnen, J. H. Biomed. Chromatogr. 2004, 18, 400-402
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