1,364 research outputs found

    Análise de Resíduos de Disparos de Armas de Fogo usando ICP OES: desenvolvimento de uma nova metodologia analítica.

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    A violência envolvendo armas de fogo representa um grande problema no Estado do Espírito Santo e o desenvolvimento de novos métodos e técnicas que possam auxiliar a polícia na elucidação de homicídios é de fundamental importância para a redução da criminalidade. A espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) ganha destaque por ser uma técnica de alta sensibilidade, versátil e mais barata quando comparada com técnicas atualmente utilizadas pela polícia. Desta forma o objetivo deste trabalho foi desenvolver uma metodologia rápida, sensível e confiável para coleta e quantificação de resíduos de disparos de armas de fogo (GSR) utilizando a técnica de ICP OES para medir as concentrações de Chumbo (Pb), Bário (Ba) e Antimônio (Sb) liberados em revólver calibre .38 e pistolas calibres .380 e .40. O trabalho dividiu-se em três capítulos. O capítulo 1 abordou a etapa de otimização da técnica de ICP OES para GSR, no qual foram avaliados os parâmetros operacionais de potência, fluxo do gás de nebulização e taxa de aspiração, utilizando planejamento multivariado. No capítulo 2foi realizado um estudo para revólver Taurus.38, no qual investigou-se a melhor região de coleta da mão em homens e mulheres, a viabilidade de diferentes coletores para GSR, a comparação do teste colorimétrico e da técnica de ICP OES para distâncias variadas e a influência da lavagem da mão antes e após os disparos. Os resultados mostraram que as regiões das pinças dorsal e palmar são os melhores locais de coleta e que o swab puro apresentou melhores resultados em termos de custo/benefício e que é possível obter concentrações dos metais de interesse mesmo com a lavagem da mão do atirador. No capítulo 3 foi feito um estudo comparativo entre revólver .38 e pistolas .380 e .40. Foram quantificados Pb, Ba e Sb na mão direita e esquerda dos atiradores para as três armas e realizada uma predição do número de disparos através da construção de uma curva de calibração. Foi observado a quantidade de GSR encontrado nas armas segue a ordem revólver .38 > pistola .380 > pistola .40. Os resultados gerais mostraram importantes informações em análises de GSR, representando um avanço nas investigações forenses

    Noise reduction in muon tomography for detecting high density objects

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    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented

    Precision measurements of Linear Scattering Density using Muon Tomography

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    We demonstrate that muon tomography can be used to precisely measure the properties of various materials. The materials which have been considered have been extracted from an experimental blast furnace, including carbon (coke) and iron oxides, for which measurements of the linear scattering density relative to the mass density have been performed with an absolute precision of 10%. We report the procedures that are used in order to obtain such precision, and a discussion is presented to address the expected performance of the technique when applied to heavier materials. The results we obtain do not depend on the specific type of material considered and therefore they can be extended to any application.Comment: 16 pages, 4 figure

    Mycobacterium tuberculosis Immune Response in Patients With Immune-Mediated Inflammatory Disease

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    Subjects with immune-mediated inflammatory diseases (IMID), such as rheumatoid arthritis (RA), have an intrinsic higher probability to develop active-tuberculosis (TB) compared to the general population. The risk ranges from 2.0 to 8.9 in RA patients not receiving therapies. According to the WHO, the RA prevalence varies between 0.3% and 1% and is more common in women and in developed countries. Therefore, the identification and treatment of TB infection (TBI) in this fragile population is important to propose the TB preventive therapy. We aimed to study the M. tuberculosis (Mtb) specific T-cell response to find immune biomarkers of Mtb burden or Mtb clearance in patients with different TB status and different risk to develop active-TB disease. We enrolled TBI subjects as example of Mtb-containment, the active-TB as example of a replicating Mtb status, and the TBI-IMID as fragile population. To study the Mtb-specific response in a condition of possible Mtb sterilization, we longitudinally enrolled TBI subjects and active-TB patients before and after TB therapy. Peripheral blood mononuclear cells were stimulated overnight with Mtb peptides contained in TB1- and TB2-tubes of the Quantiferon-Plus kit. Then, we characterized by cytometry the Mtb-specific CD4 and CD8 T cells. In TBI-IMID, the TB therapy did not affect the ability of CD4 T cells to produce interferon-γ, tumor necrosis factor-α, and interleukin-2, their functional status, and their phenotype. The TB therapy determined a contraction of the triple functional CD4 T cells of the TBI subjects and active-TB patients. The CD45RA- CD27+ T cells stood out as a main subset of the Mtb-specific response in all groups. Before the TB-preventive therapy, the TBI subjects had higher proportion of Mtb-specific CD45RA-CD27+CD4+ T cells and the active-TB subjects had higher proportion of Mtb-specific CD45RA-CD27-CD4+ T cells compared to other groups. The TBI-IMID patients showed a phenotype similar to TBI, suggesting that the type of IMID and the IMID therapy did not affect the activation status of Mtb-specific CD4 T cells. Future studies on a larger and better-stratified TBI-IMID population will help to understand the change of the Mtb-specific immune response over time and to identify possible immune biomarkers of Mtb-containment or active replication

    Monitoring the degradation and the corrosion of naphthenic acids by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry and atomic force microscopy

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    AbstractAlthough the term “naphthenic acids” was originally used to describe acids that contain naphthenic rings, today this term is used in a more general sense and refers to all components in the acid extractable fraction. In crude oil, naphthenic acids exist as a complex mixture of compounds with broad polydispersity with respect to both molecular weight and structure. There has been increasing interest in the naphthenic acids in crude oil because of the corrosion problems that cause during oil refining. Herein, two powerful analytical tools, negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, ESI(-)FT-ICR MS and atomic force microscopy (AFM), were combined to monitor the thermal degradation of naphthenic acids and their corrosion effects on AISI 1020 steel, respectively. Two different acidic crude oils (TAN=2.38 and 4.79mgKOHg−1, and total sulfur=0.7993 and 1.0220wt%) have been submitted to thermal treatment at 280, 300 and 350°C during 2, 4 and 6h, and characterized by ESI(-)-FT-ICR MS, total acid number (TAN), and total sulfur. The AISI 1020 steel was analyzed by scanning electron microscopy (SEM) and AFM. Generally, heating the crude oil at 350°C in a period of 6h, it was observed that a high efficiency (≅80%) and selectivity of thermal decarboxylation process was monitored by decay of TAN (4.79→0.44mgKOHg−1). ESI(-)-FT-ICR MS results showed that naphthenic acid species remained after the heating have DBE ranging 1–12 and carbon number from C15 to C45. AFM topographic profile evidenced that the naphthenic acid corrosion of the crude oil with TAN of 4.73mgKOHg−1 on AISI 1020 steel was profoundly altered and a marked reduction in peak to peak height values (obtained by subtracting the value of the lowest peak by the highest peak in the topographic area examined). Optical images and microphotographs confirmed the presence of irregularities, characterizing the corrosion mechanism as pitting type. The naphthenic corrosion was also evidenced in samples with low TAN value (0.44mgKOHg−1)

    Emotional Appetite Questionnaire : psychometric properties in Brazilian adult samples before and after the COVID-19 pandemic onset

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    Background: Appetite represents a desire of a person to eat specific food in order to reach satisfaction and pleasure states. This desire may be associated with the experience of negative or positive emotions (emotional appetite). Emotional appetite can influence eating behavior, and its investigation is relevant to avoid possible damage to health resulting from a disordered eating. Objectives: To adapt the Emotional Appetite Questionnaire (EMAQ) to the Portuguese language; to assess the validity and reliability of the data; and to assess emotional appetite in three samples of adults collected before and after the outbreak of the COVID-19 pandemic. Methods: This is a cross-sectional study with non-probabilistic convenience sampling. The Portuguese version of the EMAQ was presented after translation, back-translation, and content analysis. Two studies were conducted, the first before and the second after the pandemic onset. Three samples were formed (2019: Sample 1 (age = 19.7 ± 1.5 years) n = 323; 2020: Sample 2 (age = 21.3 ± 1.8 years) n = 1,011; and Sample 3 (age = 28.9 ± 3.1 years) n = 909). An exploratory strategy with parallel analysis was performed. The analyses were conducted in FACTOR and R (lavaan and semTools packages) software. After determining the best-fit model for the data, emotional appetite was examined considering decrease, non-alteration, and increase in appetite in the face of positive and negative emotions/situations. The profile of emotional appetite was determined using a circumplex model. Results: The two-factor model described by the valence of emotions/situations fitted the samples (Comparative Fit Indexminimum-maximum = 0.95–0.98; Tucker-Lewis Index = 0.94–0.98; Root Mean Square Error of Approximation = 0.03–0.08; aord = 0.78–0.88). Increases in appetite were more frequent for positive emotions/ situations (52.0–57.5%), and both decreases (35.4–44.5%) and increases (50.0–56.2%) in appetite were observed for negative emotions/situations. Emotions with negative valence and activation were more relevant to appetite reduction, while a significant increase in appetite was observed with anxiety (negative valence and positive activation). Conclusion: Different emotions and situations may influence appetite in people, and such an investigation may be useful in preparing eating protocols.publishedVersionPeer reviewe

    Multicenter analysis of sputum microbiota in tuberculosis patients.

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    The impact of tuberculosis and of anti-tuberculosis therapy on composition and modification of human lung microbiota has been the object of several investigations. However, no clear outcome has been presented so far and the relationship between M. tuberculosis pulmonary infection and the resident lung microbiota remains vague. In this work we describe the results obtained from a multicenter study of the microbiota of sputum samples from patients with tuberculosis or unrelated lung diseases and healthy donors recruited in Switzerland, Italy and Bangladesh, with the ultimate goal of discovering a microbiota-based biomarker associated with tuberculosis. Bacterial 16S rDNA amplification, high-throughput sequencing and extensive bioinformatic analyses revealed patient-specific flora and high variability in taxon abundance. No common signature could be identified among the individuals enrolled except for minor differences which were not consistent among the different geographical settings. Moreover, anti-tuberculosis therapy did not cause any important variation in microbiota diversity, thus precluding its exploitation as a biomarker for the follow up of tuberculosis patients undergoing treatment

    Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

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    The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO
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