3,337 research outputs found

    Thermodynamics of the quantum spin-S XXZ chain

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    The thermodynamics of the spin-SS anisotropic quantum XXZXXZ chain with arbitrary value of SS and unitary norm, in the high-temperature regime, is reported. The single-ion anisotropy term and the interaction with an external magnetic field in the zz-direction are taken into account. We obtain, for arbitrary value of SS, the ÎČ\beta-expansion of the Helmholtz free energy of the model up to order ÎČ6\beta^6 and show that it actually depends on 1S(S+1)\frac{1}{S(S+1)}. Its classical limit is obtained by simply taking S→∞S\to \infty. At h=0h=0 and D=0, our high temperature expansion of the classical model coincides with Joyce's exact solution\cite{joyce_prl}. We study, in the high temperature region, some thermodynamic quantities such as the specific heat and the magnetic susceptibility as functions of spin and verify for which values of SS those thermodynamic functions behave classically. Their finite temperature behavior is inferred from interpolation of their high- and low-temperature behavior, and shown to be in good agreement with numerical results. The finite temperature behavior is shown for higher values of spin.Comment: 18 pages, 14 figure

    Tissue Factor-dependent Coagulation Activation By Heme: A Thromboelastometry Study

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Heme has been characterized as potent trigger of inflammation. In hemostasis, although heme has been shown to both induce and inhibit different compartments of hemostasis, its net effect on the hemostatic balance, and the biological relevance of these effects remain to be determined. Herein we evaluated the effect of heme on hemostasis using a global assay able to generate clinically relevant data in several other complex hemostatic diseases. Citrated whole blood samples from healthy participants were stimulated by heme or vehicle and incubated for 4h at 37 degrees C. Rotational thromboelastometry was immediately performed. The participation of tissue factor in coagulation activation was evaluated using inhibitory antibody. Heme was able of inducing ex vivo coagulation activation in whole blood, affecting predominantly parameters associated with the initial phases of clot formation. This activation effect was at least partially dependent on hematopoietic tissue factor, since the effects of heme were partially abrogated by the inhibition of human tissue factor. In conclusion, using a global hemostasis assay, our study confirmed that heme is able to activate coagulation in whole blood, in a tissue factor-dependent way. These findings could explain the disturbance in hemostatic balance observed in conditions associated with the release of heme such as sickle cell disease.124Fapesp [2013/09319-0, 2014/00984-3, 2015/24666-3]CNPq-Brazil [2014/457780]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Expressions of the Individual’s behavior in Digital Network: Education in a Technological Society

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    The article assumes that the behavior of expressions of individuals is related to the digital network, in which forms of human relationships are being forged in order to understand differently the process of teaching and learning with autonomy that can generate a new way of thinking, creating values and representations. This may resize behaviors in individuals and affect the perception of the subject in relation to themselves and others. New technologies, consumption and media influence shape and build the contemporary psyche. Thus, it becomes essential to consider the force with which the new messaging serving media plays in order to socialize and in the individual subjectivity. In this context, new challenges for education that allow the birth of studies and concepts, in order to explain this new reality and to contribute to the art of teaching and learning. One of these, therefore, will be part of this work, which is called Informational Normosis or Informatosis

    Proposal of a virtual collaborative news environment: an interdisciplinary study

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    The main objective of this work is to demonstrate the advances made by the CATI research group with regard to the proposal to create a virtual collaborative news environment (AVNC) , to be initially implemented at the Northern Fluminense Darcy Ribeiro State University(UENF) through the Postgraduate Program in Cognition and Language. This interdisciplinary environment involves concepts from the area of communication, administration and information technology and seeks to meet the demands of generation, storage, retrieval, processing and transmission of information in this digital age. The AVNC involves three research fronts: rethinking the logic of news production, structuring a platform that is collaborative and defining what a business and management model should be that can give sustainability to this environment. In today\u27s world, it is important to consider the reader\u27s increasingly active participation in journalism, through information and communication technologies, thanks to the social changes that come with them. In times of cyberspace and cyberculture, it is necessary to rethink the dynamics of journalistic production. For this, authors like Pierre LĂ©vy, LĂșcia Santaella, Henry Jenkins, Caio TĂșlio Costa, among others were searched. In an era in which forms of collaborative ownership prevail, the platform being considered in this research follows the 3C collaboration model, according to Michalsky, Mamani, and Gerosa. A global platform where individuals interact, communicate, collaborate and gather information requires a business model and management that assists in managing the collaborative virtual news environment. For this, we used authors such as Alex Osterwalder, Eric Flamholtz, Siqueira and Crispim, Campos, among others. With this, an increasingly intelligent and collaborative environment is expected, with the active participation of all the agents involved. That is, what is proposed is the total interaction of the Internet user-reader

    Virtual Environment, Digital Hypertext, Reading and Writing in Foreign Language

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    This work intends to analyze - in an activity carried out with students from the third period of the Language (Spanish) undergraduate course of a college located in Itaperuna, a town in the State of Rio de Janeiro, Brazil - how the digital hyper textual reading can facilitate the selection of information in order to facilitate the writing process of texts in Spanish that can be broadcasted in the virtual environment, verifying how this may happen, so that these productions are shared, also allowing the interaction of the subjects with the language and with their peers. For this objective, we used the qualitative methodology (Erickson, 1986) with action research, seeking foundation in what theorists such as Lévy (1996, 1999), Coscarelli (2006, 2009), Gomes et al. (2015), Bannell et al. (2016), among others, investigate. As results, we emphasize that the subjects of the research actively participated in the construction of their own learning regarding the aspects covered in the foreign language class, and with this they were able to practice reading, writing, and the USAge of the vocabulary and grammar studied. Finally, we conclude that the hypertext worked here as an inclusive device, facilitator of reading and propitiator of writing, making the participant students authors of digital texts that provided them with learning throughout all the process they have been through

    Time-course of sFlt-1 and VEGF-A release in neutropenic patients with sepsis and septic shock: a prospective study

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    <p>Abstract</p> <p>Background</p> <p>Septic shock is the most feared complication of chemotherapy-induced febrile neutropenia. So far, there are no robust biomarkers that can stratify patients to the risk of sepsis complications. The VEGF-A axis is involved in the control of microvascular permeability and has been involved in the pathogenesis of conditions associated with endothelial barrier disruption such as sepsis. sFlt-1 is a soluble variant of the VEGF-A receptor VEGFR-1 that acts as a decoy receptor down-regulating the effects of VEGF-A. In animal models of sepsis, sFlt-1 was capable to block the barrier-breaking negative effects of VEGF-A and to significantly decrease mortality. In non-neutropenic patients, sFlt-1 has been shown to be a promising biomarker for sepsis severity.</p> <p>Methods</p> <p>We prospectively evaluated concentrations of sFlt-1 and VEGF-A at different time-points during febrile neutropenia, and evaluated the association of these levels with sepsis severity and septic shock development.</p> <p>Results</p> <p>Neutropenic patients that evolved with septic shock (n = 10) presented higher levels of sFlt-1 and VEGF-A measured 48 hours after fever onset than patients with non-complicated sepsis (n = 31) and levels of these biomarkers correlated with sepsis severity scores. Estimation of the diagnostic accuracy of sFlt-1 levels for the discrimination of patients that evolved to septic shock yielded promising results in our study population.</p> <p>Discussion</p> <p>Our data suggest that sFlt-1 and VEGF-A could be useful biomarkers for sepsis severity in patients with febrile neutropenia. In addition, the kinetics of sFlt-1 release in patients that evolve to septic shock suggest that the sFlt-1 could be a salvage compensatory mechanism in patients with septic shock, but that the magnitude of the sFlt-1 release observed in human sepsis is not sufficient to reproduce the beneficial anti-VEGF-A effects observed in animal models of sepsis.</p

    Comparison of antibodies that mediate HIV type 1 gp120 antibody-dependent cell-mediated cytotoxicity in asymptomatic HIV type 1-positive men and women

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    Recent studies suggest that HIV-specific antibody-dependent cell-mediated cytotoxicity (ADCC) antibodies contribute to protective immunity against HIV. An important characteristic of future HIV vaccines will, therefore, be the ability to stimulate production of these antibodies in both men and women. Early studies suggest that men may have a better ADCC antibody response against HIV than women. Our objective was to determine whether men and women differ with respect to their ADCC response to HIV-1 gp120. HIV-positive, asymptomatic untreated men and women were matched for race, age, CD4(+) T cell number, HIV-1 viral load, and treatment and HIV-1 gp120 ADCC antibody titers were compared. A standard (51)Cr-release assay was used to determine HIV-1 gp120 ADCC antibody titers in HIV-1-seropositive individuals from the Multicenter AIDS Cohort Study (MACS; n=32) and the Women's Interagency HIV Study (WIHS; n=32). Both sexes had high ADCC titers against HIV-1 gp120: 34.4% (n=11) and 40.6% (n=13) of men and women, respectively, had titers of 10,000; 62.5% (n=20) and 56.3% (n=18) had titers of 100,000. Groups did not differ in percent specific release (% SR), lytic units (LU), correlations of titer to viral load, or titer to CD4(+) T cells in men or women. Both groups also had similar cross-clade ADCC antibody responses (p>0.5 for % SR and LU). Comparable groups of asymptomatic HIV-1-infected men and women had comparable HIV-1 gp120 ADCC antibodies. Both sexes had significant cross-clade reactivity. Differences between men and women may become evident as disease progresses; this should be evaluated at later stages of HIV-1 infection

    Bilayer mucoadhesive buccal film for mucosal ulcers treatment: development, characterization, and single study case

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    The formation of mucosal ulcers is an end result of epithelial damage, and it occurs due to some specific causes, such as trauma, aphthous stomatitis, lichen planus and lichenoid reactions, cytotoxic effects of chemotherapy and radiation, and drug-induced hypersensitivity reactions and malignant settings. This study focused on films for target drug delivery with respect to the treatment of the diseases of the oral mucosa, specifically mucositis. The results of a single clinical study as a pre-experimental design was performed and followed up to the outcome until 30 days. The polymeric film was prepared in a mucoadhesive bilayer structure: the basal layer with lidocaine HCl had a faster release than the apical layer with benzydamine HCl and N-acetyl-cysteine. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and SEM characterized the physical–chemical and morphological properties. The cell viability and cytotoxicity were evaluated in cell line MCF7. The transport mechanism of the solvent (swelling) and the drugs in the basal or apical layer (drug release) was explained with mathematical models. To evaluate the effect of movement inside the mouth, the folding endurance was determined. The mucoadhesive bilayer film is biologically safe and stimulates cellular proliferation. A single study in vivo demonstrated the therapeutic effect of the mucoadhesive bilayer film in buccal mucositis.The authors express their gratitude to financial support from CAPES/PROSUP-Brazil; Sao Paulo Research Foundation 2011/21219-5; Sao Paulo Research Foundation. 2018/13432-0; Sao Paulo Research Foundation. 2018/11350-6; National Council for Scientific and Technological Development (CNPq) 425271/2016-1.info:eu-repo/semantics/publishedVersio

    Safety and Immunogenicity of an In Vivo Muscle Electroporation Delivery System for DNA-hsp65 Tuberculosis Vaccine in Cynomolgus Monkeys

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    A Bacille Calmette–GuĂ©rin (BCG) is still the only licensed vaccine for the prevention of tuberculosis, providing limited protection against Mycobacterium tuberculosis infection in adulthood. New advances in the delivery of DNA vaccines by electroporation have been made in the past decade. We evaluated the safety and immunogenicity of the DNA-hsp65 vaccine administered by intramuscular electroporation (EP) in cynomolgus macaques. Animals received three doses of DNA-hsp65 at 30-day intervals. We demonstrated that intramuscular electroporated DNA-hsp65 vaccine immunization of cynomolgus macaques was safe, and there were no vaccine-related effects on hematological, renal, or hepatic profiles, compared to the pre-vaccination parameters. No tuberculin skin test conversion nor lung X-ray alteration was identified. Further, low and transient peripheral cellular immune response and cytokine expression were observed, primarily after the third dose of the DNA-hsp65 vaccine. Electroporated DNA-hsp65 vaccination is safe but provides limited enhancement of peripheral cellular immune responses. Preclinical vaccine trials with DNA-hsp65 delivered via EP may include a combination of plasmid cytokine adjuvant and/or protein prime–boost regimen, to help the induction of a stronger cellular immune response
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