RELATO DE EXPERIÊNCIAS: as ciências Física coletadas para atividades de popularização relacionadas à educação básica

A Física é a ciência que estuda as coisas naturais. É uma ciência de conteúdo vasto e sem fronteiras, que aborda todos os fenômenos da natureza. Ela também vem nos dizer que a ciência é uma construção humana, e que para tanto devemos tentar absorver o máximo que a natureza nos revela para melhor entendermos o funcionamento do mundo que nos cerca

Infraspecific variability in the essential oil composition of Lychnophora ericoides

Variations in the composition of the leaf essential oils of wild Lychnophora ericoides, with and without scent, which were grown in three sampling sites, were examined by GC-MS. Results were submitted to principal component and cluster analysis which allowed for two groups of essential oils to be distinguished with regard to scent: cluster I with specimens exhibiting an aromatic scent and containing a high percentage of α-bisabolol (34 ± 23%) and o-cymene (8.4 ± 6.9%); cluster II with specimens without any scent and characterised by a high percentage of caryophyllene oxide (11 ± 9%) and δ-elemene (5.7 ± 6.9%). The two types of oil coexist in all the populations under study, although patterns of aromatic samples deriving from Caldas Novas' State Park reveal chemical differences in relation to the samples from Brasília's National Park and Santo Antônio do Descoberto. Such chemical variations clearly suggest, apart from a geographical influence, genetic differences between individuals in the populations. The high content of α-bisabolol supports the folk medicinal use of arnica as anti-inflammatory

SETDB2 and RIOX2 are differentially expressed among renal cell tumor subtypes, associating with prognosis and metastization

Increasing detection of small renal masses by imaging techniques entails the need for accurate discrimination between benign and malignant renal cell tumors (RCTs) as well as among malignant RCTs, owing to differential risk of progression through metastization. Although histone methylation has been implicated in renal tumorigenesis, its potential as biomarker for renal cell carcinoma (RCC) progression remains largely unexplored. Thus, we aimed to characterize the differential expression of histone methyltransferases (HMTs) and histone demethylases (HDMs) in RCTs to assess their potential as metastasis biomarkers. We found that SETDB2 and RIOX2 (encoding for an HMT and an HDM, respectively) expression levels was significantly altered in RCTs; these genes were further selected for validation by quantitative RT-PCR in 160 RCTs. Moreover, SETDB2, RIOX2, and three genes encoding for enzymes involved in histone methylation (NO66, SETD3, and SMYD2), previously reported by our group, were quantified (RT-PCR) in an independent series of 62 clear cell renal cell carcinoma (ccRCC) to assess its potential role in ccRCC metastasis development. Additional validation was performed using TCGA dataset. SETDB2 and RIOX2 transcripts were overexpressed in RCTs compared to renal normal tissues (RNTs) and in oncocytomas vs. RCCs, with ccRCC and papillary renal cell carcinoma (pRCC) displaying the lowest levels. Low SETDB2 expression levels and higher stage independently predicted shorter disease-free survival. In our 62 ccRCC cohort, significantly higher RIOX2, but not SETDB2, expression levels were depicted in cases that developed metastasis during follow-up. These findings were not apparent in TCGA dataset. We concluded that SETDB2 and RIOX2 might be involved in renal tumorigenesis and RCC progression, especially in metastatic spread. Moreover, SETDB2 expression levels might independently discriminate among RCC subgroups with distinct outcome, whereas higher RIOX2 transcript levels might identify ccRCC cases with more propensity to endure metastatic dissemination.This study was funded by research grants from Research Center of Portuguese Oncology Institute - Porto (CI-IPOP 4-2012 and CI-IPOP 27) and from Associacao Portuguesa de Urologia (APU-2010). ASP-L was supported by FCT-Fundacao para a Ciencia e a Tecnologia fellowship (SFRH/SINTD/94217/2013). CSG is supported by FCT- Fundacao para a Ciencia e Tecnologia PhD fellowships (SFRH/BD/92786/2013) and BMC is funded by FCT-Fundacao para a Ciencia e a Tecnologia (IF/00601/2012).info:eu-repo/semantics/publishedVersio

Y-system for Scattering Amplitudes

We compute N=4 Super Yang Mills planar amplitudes at strong coupling by considering minimal surfaces in AdS_5 space. The surfaces end on a null polygonal contour at the boundary of AdS. We show how to compute the area of the surfaces as a function of the conformal cross ratios characterizing the polygon at the boundary. We reduce the problem to a simple set of functional equations for the cross ratios as functions of the spectral parameter. These equations have the form of Thermodynamic Bethe Ansatz equations. The area is the free energy of the TBA system. We consider any number of gluons and in any kinematic configuration.Comment: 69 pages, 19 figures, v2: references added, minor addition

The Usage of Julia Programming in Grounding Grids Simulations : An alternative to MATLAB and Python

Matlab and Python have been widely used in science field, mainly used by scientists who are involved in numerical and technical computing. However, other programming languages have arisen in recent years aim to create a combination of power, and efficiency for free. In light of this, this work presents a comparison between three computational environments (MATLAB, Python and Julia) - on the study of grounding grids for lightning transients - to evaluate the best programming language (among all studied). The main parameter presented on this paper is computational time. The results showed Julia programming language provided simulations six times faster than Matlab and twenty-eight faster than Python

Adenine interaction with and adsorption on Fe-ZSM-5 zeolites: A prebiotic chemistry study using different techniques

Most adsorption experiments are performed under conditions that did not exist on Earth before the life arose on it. Because adsorption is the first step for all other processes (protection against degradation and polymerization), it is important that it is performed under conditions that existed on prebiotic Earth. In this paper, we use an artificial seawater (seawater 4.0 Ga), which contains major cations and anions that could present on the oceans of the prebiotic Earth. In addition, zeolites, with substituted Fe in the framework, and adenine were probably common substances on the prebiotic Earth. Thus, study the interaction between them is an important issue in prebiotic chemistry. There are two main findings described in this paper. Firstly, zeolites with different Si/Fe ratios adsorbed adenine differently. Secondly, XAFS showed that, after treatments with seawater 4.0 Ga and adenine, an increase in the complexity of the system occurred. In general, salts of seawater 4.0 Ga did not affect the adsorption of adenine onto zeolites and adenine adsorbed less onto zeolites with iron isomorphically substituted. The C=C and NH2 groups of adenine interacted with the zeolites. Gypsum, formed from aqueous species dissolved in seawater 4.0 Ga, precipitated onto zeolites. EPR spectra of zeolites showed lines caused by Fe framework and Fe3+ species. TG curves of zeolites showed events caused by loss of water weakly bound to zeolite (in the 30-140 °C range), water bounded to iron species or cations from seawater 4.0 Ga or located in the cavities of zeolites (157-268 °C) and degradation of adenine adsorbed onto zeolites (360-600 °C). Mass loss follows almost the same order as the amount of adenine adsorbed onto zeolites. The XAFS spectrum showed that Fe3+ could be substituted into the framework of the Fe7-ZSM-5 zeolite