3,328 research outputs found

    Dynamical amplification of magnetoresistances and Hall currents up to the THz regime

    Full text link
    Spin-orbit-related effects offer a highly promising route for reading and writing information in magnetic units of future devices. These phenomena rely not only on the static magnetization orientation but also on its dynamics to achieve fast switchings that can reach the THz range. In this work, we consider Co/Pt and Fe/W bilayers to show that accounting for the phase difference between different processes is crucial to the correct description of the dynamical currents. By tuning each system towards its ferromagnetic resonance, we reveal that dynamical spin Hall angles can non-trivially change sign and be boosted by over 500%, reaching giant values. We demonstrate that charge and spin pumping mechanisms can greatly magnify or dwindle the currents flowing through the system, influencing all kinds of magnetoresistive and Hall effects, thus impacting also dc and second harmonic experimental measurements.Comment: 19 pages, 4 figures, Supplementary Informatio

    What are the Best Hierarchical Descriptors for Complex Networks?

    Full text link
    This work reviews several hierarchical measurements of the topology of complex networks and then applies feature selection concepts and methods in order to quantify the relative importance of each measurement with respect to the discrimination between four representative theoretical network models, namely Erd\"{o}s-R\'enyi, Barab\'asi-Albert, Watts-Strogatz as well as a geographical type of network. The obtained results confirmed that the four models can be well-separated by using a combination of measurements. In addition, the relative contribution of each considered feature for the overall discrimination of the models was quantified in terms of the respective weights in the canonical projection into two dimensions, with the traditional clustering coefficient, hierarchical clustering coefficient and neighborhood clustering coefficient resulting particularly effective. Interestingly, the average shortest path length and hierarchical node degrees contributed little for the separation of the four network models.Comment: 9 pages, 4 figure

    Secondary Metabolites

    Get PDF
    Plants are the main source for obtaining secondary metabolites that are used in the pharmaceutical, cosmetic and food industries. In nature, the performance of bioactive compounds is affected by biotic and abiotic factors, an alternative to overcome this adversity is in vitro plant cultures and particularly plant cell culture that has multiple advantages, highlighting the possibility of controlling variables to increase the content. of compounds of interest. The objective of this research was to determine and optimize the effect of some elicitors on the production of secondary flavonoid metabolites in suspension cell cultures of Thevetia peruviana on a shake flask scale. The experimental part was performed from cell cultures in suspension cells of T. peruviana maintained by the Bioconversion Laboratory of the Universidad Nacional de Colombia, sede Medellin. Firstly, methyl jasmonate (MeJa) 3 µM and salicylic acid (SA) 300 µM were added to two los of cell cultures, that circumstantially they differed in their time suspension state lot 1 (9 months) and lot 2 (3 months). Secondly, certain were evaluated, in order to be optimized; the operational parameters cosidered were: day of addition, concentration and hours of harvest. Finally, the combined effect of MeJa (0.3 µM) and SA (100 µM) was determined in different proportions, the day of elicitation and the hours of harvest were constant. Flavonoid content was quantified by UV-vis spectrophotometry usinfg the AlCl3 complexation method and was evaluated at extracellular and intracellular level. In the first part, at intracellular level, SA generated 14.6 % and 9.56 % more flavonoid content than MeJa in lots 1 and 2, respectively. In the second part, 4.14 mg EQ/g DW were generated with MeJa 0.3 µM, elicitation day 5 and harvest at 90 h; 3.75 mg EQ/g DW were generated with 100 µM SA, elicitation day 0 and harvests at 96 h. In the third part, 4.62 mg EQ / g DW were generated with the combination of MeJa (0.3 µM) – SA (100 µM) in a ratio of 20-80, elicitation on day 0 and harvest at 96 h. Eliciting cell cultures of Thevetia peruviana with MeJa and SA under optimal conditions of concentration, day of addition and hours of harvest increased the content of flavonoid compounds. The results obtained could serve as a basis for the development of investigations at the bioreactor scale.Las plantas son la principal fuente para la obtención de metabolitos secundarios que se usan en la industria farmacéutica, cosmética y alimentaria. En la naturaleza el rendimiento de compuestos bioactivos se ve afectado por factores bióticos y abióticos, una alternativa para superar esta adversidad son los cultivos vegetales in vitro y particularmente el cultivo de células en suspensión que presenta múltiples ventajas destacándose la posibilidad de controlar variables para aumentar el contenido de compuestos de interés. El objetivo del presente trabajo de investigación fue determinar y optimizar el efecto de algunos elicitores sobre la producción de metabolitos secundarios tipo flavonoides en cultivos de células en suspensión de Thevetia peruviana a escala de matraz agitado. La parte experimental se realizó a partir de cultivos de células en células en suspensión de T. peruviana que mantenía el laboratorio de bioconversiones de la Universidad Nacional de Colombia sede Medellín. Primeramente, metil jasmonato (MeJa) 3 μM y ácido salicílico (AS) 300 μM se adicionaron a dos lotes de cultivos de células; que circunstancialmente diferían en su tiempo en estado de suspensión lote 1 (9 meses) y lote 2 (3 meses). Segundamente, determinadas condiciones fueron evaluadas, con el fin de ser optimizadas; los parámetros operacionales que se consideraron fueron: día de adición, concentración y las horas de cosecha. Por último, el efecto combinado de MeJa (0,3 μM) – AS (100 μM) se determinó en diferentes proporciones, el día de elicitación y las horas de cosecha fueron constantes. El contenido de flavonoides se cuantificó por espectrofotometría UV – vis por el método de complejación de AlCl3 y se evaluaron a nivel extracelular e intracelular. En la primera parte, a nivel intracelular AS generaron 14,6 % y 9,56 % más contenido de flavonoides que MeJa en lotes 1 y 2, respectivamente. En la segunda parte, 4,14 mg EQ/g MS fueron generados con MeJa 0,3 μM, elicitación día 5 y cosecha a 90 h; por otro lado, 3,75 mg EQ/g MS fueron generados con AS 100 μM, elicitación día 0 y cosecha a 96 h. En la tercera parte, 4,62 mg EQ/g MS fueron generados con la combinación de MeJa (0,3 μM) – AS (100 μM) en proporción 20 – 80, elicitación el día 0 y cosecha a las 96 h. Elicitar cultivos celulares de Thevetia peruviana con MeJa y AS en condiciones óptimas de concentración, día de adición y horas de cosecha incrementaron el contenido de compuestos flavonoides. Los resultados obtenidos podrían servir como base para el desarrollo de investigaciones a escala de biorreactor.Maestrí

    Upregulation of Nrf2 and decreased redox signaling contribute to renoprotective effects of chemerin receptor blockade in diabetic mice

    Get PDF
    Chemerin, acting through its receptor ChemR23, is an adipokine associated with inflammatory response, glucose and lipid metabolism and vascular function. Although this adipokine has been associated with the development and progression of kidney disease, it is not clear whether the chemerin/ChemR23 system plays a role in renal function in the context of diabetes. Therefore, we sought to determine whether ChemR23 receptor blockade prevents the development and/or progression of diabetic nephropathy and questioned the role of oxidative stress and Nrf2 in this process. Renal redox state and function were assessed in non-diabetic lean db/m and diabetic obese db/db mice treated with vehicle or CCX832 (ChemR23 antagonist). Renal reactive oxygen species (ROS) production, which was increased in diabetic mice, was attenuated by CCX832. This was associated with an increase in Nox 4 expression. Augmented protein oxidation in db/db mice was not observed when mice were treated with CCX832. CCX832 also abrogated impaired Nrf2 nuclear activity and associated downregulation in antioxidants expression in kidneys from db/db mice. Our in vivo findings highlight the role of the redox signaling and Nrf2 system as renoprotective players during chemerin receptor blockade in diabetic mice. The chemerin/ChemR23 system may be an important target to limit renal dysfunction associated with obesity-related diabetes

    Nietzsche, ressentimento e a inocência do esquecimento

    Get PDF
    O presente artigo pretende discutir o conceito de ressentimento na Genealogia da moral de Friedrich Nietzsche e em outros escritos do filósofo. Analisaremos o ressentimento em duas perspectivas. Em primeiro lugar, o ressentimento entendido como o problema individual do homem vingativo, fraco, adoecido pela incapacidade de dar conta das impressões que chegam à sua consciência. Neste primeiro momento, o ressentimento se expressa como memória das marcas, nas quais as forças ativas, aquelas que permitem a renovação da consciência estão interiorizadas no homem reativo. Posteriormente, trataremos o ressentimento como espírito de vingança, como um modo doente de existir, uma vez que o sujeito que interioriza seus instintos criadores assume como meio de vida a vingança contra os saudáveis. Nesta segunda perspectiva, o ressentimento se apresenta como um fenômeno social, cuja sede de vingança se encontra no corpo político e moral cuja organização visa a produção do homem manso, civilizado, animal doméstico, o antípoda do homem de exceção, isto é, do homem nobre nietzschiano

    Effects of Different Number of Sets of Resistance Training on Flexibility

    Get PDF
    International Journal of Exercise Science 10(3): 354-364, 2017. The aim of this study was to investigate the effects of six months of training with three different number of sets of resistance training on flexibility in young men. Forty-seven men (mean ± SD age = 24 ± 1yrs; body mass = 79.39 ± 9.12 kg; height = 174.5 ± 5.6 cm) were randomly divided into three training groups performing either one set (G1S), three sets (G3S), or five sets (G5S) of all exercises in a resistance training session or a control group (CG). All groups were assessed pre- and post-training for Sit-and-Reach test and range of motion of 10 joints using goniometry. The training protocol included three weekly sessions and was composed of nine exercises performed at a moderate intensity (eight to 12RM). The results demonstrated significant differences pre- to post-training for the Sit-and-Reach test for all training groups; however, only the G5S showed significant differences when compared to the CG (31.04 ± 5.94cm vs. 23.56 ± 6.76cm, respectively; p \u3c 0.05). Of the ten joint movements measured, there were range of motion increases only to shoulder flexion (G1S), shoulder extension (G3S), elbow flexion (G3S), and knee flexion (G3S) when comparing pre- to post-training (p \u3c 0.05). In conclusion, different resistance training volumes improved flexibility for some joints of young men. These findings indicate that performing only resistance training can result in increases in flexibility

    Estudo dos efeitos de diferentes doses de surfactante exógeno para o tratamento da síndrome de aspiração de mecônio em coelhos recém-nascidos

    Get PDF
    OBJECTIVE: To evaluate the effects of 2 different doses of exogenous surfactant on pulmonary mechanics and on the regularity of pulmonary parenchyma inflation in newborn rabbits. METHOD: Newborn rabbits were submitted to tracheostomy and randomized into 4 study groups: the Control group did not receive any material inside the trachea; the MEC group was instilled with meconium, without surfactant treatment; the S100 and S200 groups were instilled with meconium and were treated with 100 and 200 mg/kg of exogenous surfactant (produced by Instituto Butantan) respectively. Animals from the 4 groups were mechanically ventilated during a 25-minute period. Dynamic compliance, ventilatory pressure, tidal volume, and maximum lung volume (P-V curve) were evaluated. Histological analysis was conducted using the mean linear intercept (Lm), and the lung tissue distortion index (SDI) was derived from the standard deviation of the means of the Lm. One-way analysis of variance was used with a = 0.05. RESULTS: After 25 minutes of ventilation, dynamic compliance (mL/cm H2O · kg) was 0.87 ± 0.07 (Control); 0.49 ± 0.04 (MEC*); 0.67 ± 0.06 (S100); and 0.67 ± 0.08 (S200), and ventilatory pressure (cm H2O) was 9.0 ± 0.9 (Control); 16.5 ± 1.7 (MEC*); 12.4 ± 1.1 (S100); and 12.1 ± 1.5 (S200). Both treated groups had lower Lm values and more homogeneity in the lung parenchyma compared to the MEC group: SDI = 7.5 ± 1.9 (Control); 11.3 ± 2.5 (MEC*), 5.8 ± 1.9 (S100); and 6.7 ± 1.7 (S200) (*P < 0.05 versus all the other groups). CONCLUSIONS: Animals treated with surfactant showed significant improvement in pulmonary mechanics and more regularity of the lung parenchyma in comparison to untreated animals. There was no difference in results after treatment with either of the doses used.OBJETIVO: Avaliar os efeitos de duas diferentes doses de surfactante exógeno sobre a mecânica pulmonar e sobre a regularidade da expansão do parênquima pulmonar em coelhos recém-nascidos. MÉTODO: Coelhos recém-nascidos foram traqueostomizados e randomizados em quatro grupos de estudo: grupo-Controle, sem aspiração de mecônio; grupo MEC, com aspiração de mecônio e sem tratamento com surfactante exógeno; grupos S100 e S200, ambos com aspiração de mecônio e tratados respectivamente com 100 e 200 mg/kg de surfactante exógeno (produzido e fornecido pelo Instituto Butantan). Os animais dos 4 grupos foram ventilados por 25 minutos. A mecânica pulmonar foi avaliada a partir dos valores de complacência dinâmica, pressão ventilatória, volume-corrente e volume pulmonar máximo (curva P-V). A análise histológica foi feita calculando-se o diâmetro alveolar médio (Lm) e o índice de distorção através do desvio padrão do Lm. Utilizou-se ANOVA One Way com a = 0,05. RESULTADOS: Após 25 minutos de ventilação, os valores de complacência dinâmica (ml/cm H2O.kg) foram: 0,87± 0,07 (Controle); 0,49±0,04 (MEC*); 0,67±0,06 (S100) e 0,67±0,08 (S200) e de pressão ventilatória (cm H2O): 9,0± 0,9 (Controle); 16,5±1,7 (MEC*); 12,4±1,1 (S100) e 12,1±1,5 (S200). Ambos os grupos tratados tiveram padrão de expansão do parênquima mais homogêneo em relação aos animais não tratados: índice de distorção de 7,5± 1,9 (Controle); 11,3±2,5 (MEC*); 5,8±1,9 (S100) e 6,7±1,7 (S200) (*p < 0,05 vs outros grupos). CONCLUSÕES: Animais tratados com surfactante mostraram melhora significativa da mecânica pulmonar e maior homogeneidade do padrão de expansão pulmonar comparados ao grupo não tratado. Não houve influência das doses de surfactante utilizadas

    Síndrome metabólica em adolescentes obesos: comparação entre três diferentes critérios diagnósticos

    Get PDF
    Objective: To investigate the difference in the proportion of adolescents with metabolic syndrome diagnosed based on three different criteria, as well as the use of insulin resistance instead of fasting glucose.Methods: Cross-sectional study with 121 obese adolescents, between 10 and 14 years old, from public schools of the city of Porto Alegre, Brazil, in 2011. Anthropometric, blood pressure, and biochemical variables were assessed. Metabolic syndrome was defined using three different diagnostic criteria: the International Diabetes Federation (IDF), Cook and de Ferranti. All of them include five components: waist circumference, blood pressure, high-density lipoprotein (HDL) cholesterol, triglycerides and fasting glucose, and there should be at least three abnormal results for the diagnosis of the syndrome. the Homeostasis Model Assessment - Insuline Resistance (HOMA-IR) was used for the characterization of insulin resistance. the analysis of agreement among the criteria was performed using Kappa statistics.Results: Metabolic syndrome Was diagnosed in 39.7, 51.2, and 74.4% of adolescents, according to the IDF, Cook and de Ferranti criteria, respectively. There was agreement for the three diagnostic criteria in 60.3% of the sample. Waist circumference was the most prevalent component (81.0, 81.0, and 96.7%), whereas high fasting glucose was the least prevalent (7.4, 1.7, and 1.7%). the use of HOMA-IR significantly increased the proportion of positive diagnoses for the syndrome.Conclusion: the results showed significant differences between the three diagnostic criteria. While there is no consensus on the diagnostic criteria for metabolic syndrome, differences in the prevalence of the disease in pediatric population will be frequent.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundo de Incentivo a Pesquisa e Eventos (FIPE), Hospital de Clinicas de Porto Alegre (HCPA)Research and Events Incentive Fund - FIPE of Hospital de Clinicas de Porto Alegre - HCPAUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilUniv Fed Rio Grande do Sul, Escola Educ Fis ESEF, Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, ESEF, Porto Alegre, RS, BrazilUniv London, Inst Child Hlth, London WC1N 1EH, EnglandUniv Fed Rio Grande do Sul, Fac Med, Dept Pediat, Porto Alegre, RS, BrazilHCPA, Serv Pediat, Porto Alegre, RS, BrazilUniv Fed Santa Maria, Santa Maria, RS, BrazilUniversidade Federal de São Paulo UNIFESP, São Paulo, BrazilCNPq: 159754/2010-0Web of Scienc

    Dental approach of orofacial pain in head and neck cancer patients

    Get PDF
    Orofacial pain (OFP) is an undesirable sensation frequently associated with head and neck cancer (HNC) and its treatment. OFP negatively impacts the quality of life of oncological patients. The approach to OFP diagnosis and management can differ if the patient visits a dentist or physician. The aim of this study was to present a case series of HNC with OFP managed by a dentist team and to discuss its role in the management of OFP. We recruited twenty-two adult patients with OFP and previous diagnosis of HNC referred to an academic dental clinic from 2015 to 2017. Nociceptive was more frequent than mixed and neuropathic pain, however 54,4% of the cases showed a neurological component. All types of pain were managed by dentist through removal of pain?s cause and appropriated local and systemic treatment. The intensity of pain was reduced in 86,3% of patients, and 45,4% of them reported absence of pain at the end of treatment. Dentist?s assessment plays a distinct and crucial role in the diagnosis and management of OFP in HNC patients throughout the oncological treatment
    • …
    corecore