1,940 research outputs found

    Evidence of Two Distinct Dynamic Critical Exponents in Connection with Vortex Physics

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    The dynamic critical exponent zz is determined from numerical simulations for the three-dimensional (3D) lattice Coulomb gas (LCG) and the 3D XY models with relaxational dynamics. It is suggested that the dynamics is characterized by two distinct dynamic critical indices z0z_0 and zz related to the divergence of the relaxation time τ\tau by τξz0\tau\propto \xi^{z_0} and τkz\tau\propto k^{-z}, where ξ\xi is the correlation length and kk the wavevector. The values determined are z01.5z_0\approx 1.5 and z1z\approx 1 for the 3D LCG and z01.5z_0\approx 1.5 and z2z\approx 2 for the 3D XY model. It is argued that the nonlinear IVIV exponent relates to z0z_0, whereas the usual Hohenberg-Halperin classification relates to zz. Possible implications for the interpretation of experiments are pointed out. Comparisons with other existing results are discussed.Comment: to appear in PR

    A PRODUÇÃO ACADÊMICA JURÍDICA SOBRE AS AÇÕES AFIRMATIVAS NO BRASIL (2013 A 2016): TESES E DISSERTAÇÕES SOB A ÓTICA DOS DIREITOS HUMANOS E FUNDAMENTAIS

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    O presente trabalho é resultado de pesquisa consistente em levantamento da produção científica na área do Direito das Teses e Dissertações defendidas nas universidades brasileiras no período de 2013 a 2016, que tenham como pano de fundo – principal ou parcial - o tema das ações afirmativas. A metodologia utilizada na pesquisa foi a do “estado do conhecimento”, com a finalidade de mapear e levantar dados sobre o conhecimento produzido sobre esse novel tema em um universo específico. A opção pela análise das Teses e Dissertações desse período justifica-se porque os trabalhos e resumos encontram-se disponíveis no Banco de Teses da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES. A importância das ações afirmativas, como instrumentos de promoção da igualdade material ou substancial direcionados para algumas minorias sociais, em razão de exclusões históricas, se reflete não só pela produção acadêmica, mas também pelas atuais políticas públicas que têm sido amplificadas em todos os níveis federativos. A constitucionalidade de normas que criaram algumas dessas políticas de discriminação positiva foi reconhecida inclusive pelo Supremo Tribunal Federal, que as considerou como reais e necessárias medidas a serem adotadas a fim de amenizar os déficits de cidadania ou remediar as condições sociais resultantes de uma herança histórica discriminatória. Nesse trabalho mencionaremos um esboço do conteúdo jurídico das ações afirmativas e suas políticas, quais foram os principais temas tratados na referida produção científico-jurídica, a sua divisão por regiões e uma singela análise do “estado do conhecimento”

    What is the relationship between intracellular and extracellular metabolites? The theory of "metabolic overflow" put into test

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    Compared to our knowledge on metabolic pathways and the establishment of tools to manipulate these pathways, we know very little about the mechanisms behind the secretion of metabolic intermediates. Microorganisms secrete a wide range of metabolic intermediates, and many of them are of great industrial interest. Despite the cellular process of metabolite efflux being ubiquitous to all microbial cells, we still do not know clearly how this process works and how it is regulated. It is believed that small metabolites, mainly those end products of fermentation are excreted through the plasma membrane passively, or they are secreted through specialised mechanisms such as vectorial reaction in response to hypo-osmotic stress, or uniport and synport transport systems. However, all of these mechanisms are based on the concept of “metabolic overflow”, which under specific metabolic conditions it is observed a massive excretion of some metabolic intermediates due to their intracellular accumulation. Although this concept seems appropriate to explain the secretion of some intracellular metabolites, it does not apply to many cases studied during continuous culture. Our metabolomics data obtained during different time-series studies of microbial growth under continuous and batch cultures confirm that the concept of “metabolic overflow” cannot be applied to explain the efflux of several intracellular metabolites found in the extracellular medium. Most of our studies indicate that microbial cells very often get rid of some intracellular metabolites in response to an environmental stimulus, even if these metabolites are key intermediates of central carbon metabolism

    DiGeorge Syndrome: a not so rare disease

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    INTRODUCTION: The DiGeorge Syndrome was first described in 1968 as a primary immunodeficiency resulting from the abnormal development of the third and fourth pharyngeal pouches during embryonic life. It is characterized by hypocalcemia due to hypoparathyroidism, heart defects, and thymic hypoplasia or aplasia. Its incidence is 1:3000 live births and, despite its high frequency, little is known about its natural history and progression. ←This is probably due to diagnostic difficulties and the great variety of names used to describe it, such as velocardiofacial, Shprintzen, DiGeorge, and CATCH 22 Syndromes, as well as conotruncal facial anomaly. All represent the same genetic condition, chromosome 22q11.2 deletion, which might have several clinical expressions. OBJECTIVES: To describe clinical and laboratorial data and phenotypic characteristics of patients with DiGeorge Syndrome. METHODS: Patients underwent standard clinical and epidemiological protocol and tests to detect heart diseases, facial abnormalities, dimorphisms, neurological or behavioral disorders, recurrent infections and other comorbidities. RESULTS: Of 14 patients (8m - 18y11m), only one did not have 22q11.2 deletion detected. The main findings were: conotruncal malformation (n = 12), facial abnormalities (n = 11), hypocalcemia (n = 5) and low lymphocyte count (n=2). CONCLUSION: The authors pointed out the necessity of DGS suspicion in all patient presenting with heart defects, facial abnormalities (associated or not with hypocalcemia), and immunological disorders because although frequency of DGS is high, few patients with a confirmed diagnosis are followed up

    A Dumbbell-Shaped Solitary Fibrous Tumor of the Cervical Spinal Cord

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    A 40-year-old Asian female presented with a 2-month history of right shoulder pain and right triceps weakness. MRI revealed an extramedullary, extradural, dumbbell-shaped spinal cord tumor with C6 to C7 iso- and hyperintensity on T1 and T2 weighted imaging, respectively. Histological examination revealed monomorphous spindle cells with a storiform pattern. Immunohistochemistry was positive for CD34, CD99, and negative for EMA, SMA, and S100; solitary fibrous tumor (SFT) was confirmed

    Soluble human Suppression of Tumorigenicity 2 is associated with endoscopic activity in patients with moderate-to-severe ulcerative colitis treated with golimumab

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    Suppressor of Tumorigenicity 2 (ST2) is an IL33 receptor detected in the mucosa and serum of ulcerative colitis (UC) patients. We evaluated soluble ST2 (sST2) as a surrogate biomarker of disease outcome and therapeutic response, in moderate-to-severe UC patients treated with golimumab.Agência financiadora Merck Sharp and Dohme, Lda, Portugal MK8259-22info:eu-repo/semantics/publishedVersio

    Nephrogenic Diabetes Insipidus (NDI): Clinical, Laboratory and Genetic Characterization of Five Brazilian Patients

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    INTRODUCTION: Nephrogenic diabetes insipidus is characterized by a lack of response in the distal nephron to the antidiuretic hormone arginine vasopressin. Manifestations include polyuria, polydipsia, hyposthenuria, recurrent episodes of dehydration and fever and growth failure. Most cases are caused by mutations in the AVPR2 gene. The mutant receptors are trapped intracellularly. METHOD: We studied five boys using clinical, laboratory and molecular data. The mean age at diagnosis was 14.6 months (range 6 to 24) and 12.2 years (7.8 to 19) after the follow-up period. The mean period of follow-up was 132.2 ± 50.9 months. RESULTS: The geometric means of the z-scores of weight and stature were -4.5 and -3.6, respectively, at diagnosis. At the last medical appointment, the z-scores of weight and stature were -0.3 and -0.9, respectively. Three patients were diagnosed with ureterohydronephrosis and exhibited increased post-void urine volume. Mutations in the AVPR2 gene were found in all patients, and the carrier status was confirmed in four of five cases. Two unrelated children presented identical mutations (S167L) in arginine vasopressin R2. Two of the patients had a mutation that has already been described in other Brazilian families (R337X), and one patient showed a de novo mutation (Y128D) in arginine vasopressin R2, since his mother's molecular analysis was normal. The recurrence risk for this family was significantly reduced. CONCLUSION: This study reports the clinical and laboratory characterization of Nephrogenic diabetes insipidus and reiterates the importance of the genetic basis that underlies the disease diagnosis and genetic counseling

    Achados hematológicos na síndrome de Noonan

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    OBJETIVO: A síndrome de Noonan é uma patologia de múltiplas anomalias congênitas e, dentre os achados clínicos, a diátese hemorrágica está incluída. O propósito deste estudo é determinar a freqüência de anormalidades hemostáticas nos pacientes afetados. MÉTODO: Nós estudamos 30 pacientes afetados pela síndrome quanto aos aspectos hematológicos que consistiu de tempo de sangramento, tempo de protrombina, tempo de tromboplastina parcial ativada, tempo de trombina, contagem de plaquetas e dosagem do fator de coagulação XI. RESULTADOS: Um resultado laboratorial anormal foi observado em 9 desses pacientes (30%). Apesar dos achados mais comuns terem sido as deficiências dos fatores de coagulação, especialmente do fator XI, também observamos anormalidades no número e na função plaquetária. CONCLUSÕES: Anormalidades hemostáticas são observadas com certa freqüência em pacientes com síndrome de Noonan (30% em nossa amostra). Enfatizamos, portanto, a importância de uma investigação hematológica mais detalhada nesses pacientes, especialmente antes da realização de um procedimento invasivo, o qual é requerido com certa freqüência na síndrome.OBJECTIVE: Noonan syndrome is a multiple congenital anomaly syndrome, and bleeding diathesis is considered part of the clinical findings. The purpose of this study was to determine the frequency of hemostatic abnormalities in a group of Noonan syndrome patients. METHOD: We studied 30 patients with clinical diagnosis of Noonan syndrome regarding their hemostatic status consisting of bleeding time, prothrombin time, activated partial thromboplastin time and thrombin time tests, a platelet count, and a quantitative determination of factor XI. RESULTS: An abnormal laboratory result was observed in 9 patients (30%). Although coagulation-factor deficiencies, especially factor XI deficiency, were the most common hematological findings, we also observed abnormalities of platelet count and function in our screening. CONCLUSIONS: Hemostatic abnormalities are found with some frequency in Noonan syndrome patients (30% in our sample). Therefore, we emphasize the importance of a more extensive hematological investigation in these patients, especially prior to an invasive procedure, which is required with some frequency in this disorder

    Universal subgap optical conductivity in quasi-one-dimensional Peierls systems

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    Quasi-one-dimensional Peierls systems with quantum and thermal lattice fluctuations can be modeled by a Dirac-type equation with a Gaussian-correlated off-diagonal disorder. A powerful new method gives the exact disorder-averaged Green function used to compute the optical conductivity. The strong subgap tail of the conductivity has a universal scaling form. The frequency and temperature dependence of the calculated spectrum agrees with experiments on KCP(Br) and trans-polyacetylene.Comment: 11 pages (+ 3 figures), LATEX (REVTEX 3.0
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