447 research outputs found
exploding clusters dynamics probed by XUV fluorescence
Clusters excited by intense laser pulses are a unique source of warm dense
matter, that has been the subject of intensive experimental studies. The
majority of those investigations concerns atomic clusters, whereas the
evolution of molecular clusters excited by intense laser pulses is less
explored. In this work we trace the dynamics of clusters
triggered by a few-cycle 1.45-m driving pulse through the detection of XUV
fluorescence induced by a delayed 800-nm ignition pulse. Striking differences
among fluorescence dynamics from different ionic species are observed
Protocol to generate an in vitro model to study vascular calcification using human endothelial and smooth muscle cells
Vascular calcification is a systemic disease characterized by calcium salt deposition
within vascular walls. Here, we present a protocol for establishing an
advanced dynamic in vitro co-culture system using endothelial and smooth muscle
cells to replicate vascular tissue complexity. We describe steps for cell culture
and seeding in a double-flow bioreactor that recreates the action of blood in humans.
We then detail the induction of calcification, setting up of the bioreactor,
followed by cell viability assessment and calcium quantification
Phase-matching effects in the generation of high-energy photons by mid-infrared few-cycle laser pulses
We report on our experimental and theoretical investigations on the generation of high-order harmonics driven by 1500 nm few-cycle laser pulses in xenon. In contrast to the common belief, we found experimental evidence suggesting that harmonic generation driven by mid-infrared laser pulses can be realized with high efficiency; in particular, an enhancement of very high harmonic orders can be achieved under suitable conditions of the laser–medium interaction. The experimental results were simulated by a 3D non-adiabatic model. The theoretical outcomes confirm the experimental findings and provide a physical explanation for the counter-intuitive results. In particular, a time-dependent phase-matching analysis threw light on the generation mechanisms at a timescale of half optical cycle of the fundamental pulse
Análise de pedigree aplicada a rebanhos bubalinos do Estado do Pará.
O estudo da variabilidade genética nos rebanhos participantes do Programa de Melhoramento Genético de Búfalos do Estado do Pará foi realizado por meio da análise de pedigree, a qual estima parâmetros baseados na probabilidade de origem de gene: coeficiente de endogamia, parentesco, intervalo médio de gerações, número efetivo de fundadores (Nf), número efetivo de ancestrais (Na), intervalo de gerações e número efetivo de genomas remanescentes (Ng). O Nf foi igual a 28,6 animais, o Na igual a 22,8 animais, o Ng igual a 11,2, a razão Nf/Na foi 1,25, indicando a diminuição do número de reprodutores ao longo dos períodos e a razão Ng/Nf foi de 0,39. Apesar do intervalo de gerações de 12,5 anos, o número efetivo de gerações foi próximo a cinco. O número total de animais estudados considerados endogâmicos foi 33,4%, sendo o valor médio da endogamia no arquivo total de 3,5%. A adoção de acasalamentos otimizados com controle de parentesco seria uma saída para o controle da endogamia e, consequentemente, da perda de variabilidade genética
Quantum path control in harmonic generation by temporal shaping of few-optical-cycle pulses in ionizing media
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Proteomic Modulation in TGF-β-Treated Cholangiocytes Induced by Curcumin Nanoparticles
Curcumin is a natural polyphenol that exhibits a variety of beneficial effects on health, including anti-inflammatory, antioxidant, and hepato-protective properties. Due to its poor water solubility and membrane permeability, in the present study, we prepared and characterized a water-stable, freely dispersible nanoformulation of curcumin. Although the potential of curcumin nanoformulations in the hepatic field has been studied, there are no investigations on their effect in fibrotic pathological conditions involving cholangiocytes. Exploiting an in vitro model of transforming
growth factor- (TGF- )-stimulated cholangiocytes, we applied the Sequential Window Acquisition of All Theoretical Mass Spectra (SWATH-MS)-based quantitative proteomic approaches to study the proteome modulation induced by curcumin nanoformulation. Our results confirmed the well-documented anti-inflammatory properties of this nutraceutic, highlighting the induction of programmed cell death as a mechanism to counteract the cellular damages induced by TGF- . Moreover, curcumin nanoformulation positively influenced the expression of several proteins involved in TGF- -mediated fibrosis. Given the crucial importance of deregulated cholangiocyte functions during cholangiopathies, our results provide the basis for a better understanding of the mechanisms associated with this pathology and could represent a rationale for the development of more targeted therapies
Different gene expression modulation is the major effect fue to shear stress and stent application in huvecs model: preliminary results
Although it is known that disturbed shear stress may cause endothelial damage, the mechanism by which a stent procedure may affect the endothelium is not yet fully clarify. We present the preliminary data on gene expression analysis of human endothelial cells in a laminar flow bioreactor (LFB) system submitted to different physical (flow changes) and/or mechanical (stent application) stimuli. Our preliminary results show that low shear stress together with stent procedure are the experimental conditions that mainly modulate the highest number of genes in human endothelial model. Those genes belong to pathways specifically involved in the endothelial dysfunctio
Type-specific inflammatory responses of vascular cells activated by interaction with virgin and aged microplastics
Microplastics (MPs) are recognized as a major environmental problem due to their ubiquitous presence in ecosystems and bioaccumulation in food chains. Not only humans are continuously exposed to these pollutants through ingestion and inhalation, but recent findings suggest they may trigger vascular inflammation and potentially worsen the clinical conditions of cardiovascular patients. Here we combine headspace analysis by needle trap microextraction-gas chromatography-mass spectrometry (HS-NTME-GC-MS) and biological assays to evaluate the effects of polystyrene, high- and low-density polyethylene MPs on phenotype, metabolic activity, and pro-inflammatory status of Vascular Smooth Muscle Cells (VSMCs) the most prominent cells in vascular walls. Virgin and artificially aged MPs (4 weeks at 40 °C and 750 W/m2 simulated solar irradiation) were comparatively tested at 1 mg/mL to simulate a realistic exposure scenario. Our results clearly show the activation of oxidative stress and inflammatory processes when VSMCs were cultured with aged polymers, with significant overexpression of IL-6 and TNF-α. In addition, volatile organic compounds (VOCs), including pentane, acrolein, propanal, and hexanal as the main components, were released by VSMCs into the headspace. Type-specific VOC response profiles were induced on vascular cells from different MPs
Análise de pedigree como auxílio às decisões de acasalamento em bubalinos: resultados preliminares.
Parâmetros baseados na probabilidade de origem do gene foram usados para descrever a variabilidade em uma população de búfalos da Embrapa Amazônia Oriental. A magnitude dos resultados foi de média a baixa (por volta de 20 animais), sugerindo que poucos fundadores contribuiriam para a formação da população, fato confirmado em estudos e relatórios da década de 60. Dentre os 20 ancestrais que mais aportam genes ao machos (representando ao todo 71% dos alelos), 39%, 26% e 5%, respectivamente, são as contribuições marginais das raças Murrah, Mediterrâneo e mestiços. Para as fêmeas, onde os 20 ancestrais aportam 67,5% dos genes, 42% e 26%, respectivamente, são as contribuições marginais da raça Murrah e Mediterrâneo. Estudos posteriores considerarão os resultados destas análises iniciais, os quais indicaram quais ancestrais são os mais representativos, auxiliando a identificação de famílias ou linhagens, dentro de cada raça.Disponível também on-line
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