Effect of Metal-containing Nanoparticles on Bacterial Biofilms and on the Microbiome of Girardia tigrina

Anthropogenically-produced nanoparticles are a form of nanotechnology being used in industries including food and textiles. Humans and livestock are frequently exposed to metal-containing nanoparticles (MCNPs), that have been washed into streams and rivers, have been deliberately used in food packaging as antimicrobials, preservatives or for supplementation. The animal microbiome, which consists of a diverse community of microorganisms, provides a number of benefits to the host in terms of nutrition availability, immune support, and can influence behavior. Biofilms of diverse microbes may cause detrimental effects, for instance by causing dental diseases in humans. However, the scientific community has not reached consensus on if direct contact with MCNPs is harmful to animals and or the microbiomes. This study exposed the microbiota of the planarian flatworm Girardia tigrine and developing microbial biofilms to MCNPs to investigate their effect on biofilms and the microbiome of this model organism. Zinc oxide (ZnO), copper silicon (CuSi), and tribasic copper chloride (TBCC) nanoparticles were used at 6 different concentrations. ZnO NPs, CuSi NPs, and TBCC NPs, inhibited the formation of a mixed community plastic-adherent biofilm as determined by plate assay. The pure culture Staphylococcus aureus F-182 biofilm was inhibited by ZnO NPs and CuSi NPs but was not inhibited when exposed to TBCC NPs. The planarian microbiome experienced a pronounced shift from Betaproteobacteria to Gammaproteobacteria when exposed to ZnO NPs, and CuSi NPs. Of the MCNPs CuSi NPs increased the diversity of the microbiome while TBCC treatment induced minimal microbiome disruption as compared to untreated control

Bond Behaviour of Steel Reinforcing Bars Embedded in Ultra-High-Performance Steel Fiber Reinforced Concrete

Ultra-High-Performance Steel Fiber Reinforced Concrete (UHP-SFRC) is an emerging concrete considered as an optimal, durable material that can substitute conventional concrete owing to its distinct fresh and hardened properties. Thus, it is essential to understand the mechanism of stress transfer between this concrete and conventional reinforcement that permits the composite action of both materials. A four-point bending test program (FPBT) was arranged and conducted on 19 beams designed for the bond development to occur in the constant moment region along a short embedment length in order to achieve a uniform distribution of bond stresses, enabling measurement of bond strength through reverse engineering of beam strength and deformation. Additional material testing was conducted on prisms under 4-point loading in order to extract the mechanical properties for all material mixes considered. The bond-specimens failed either by pullout or by cone formation with minimal deterioration of the concrete cover, illustrating the high confinement provided by the novel concrete surrounding the bar in tension. The bond strength was determined to be directly proportional to the tensile strength capacity of the design mix, where for the strongest material the bond strength was approximately 30 MPa. Moreover, the test results indicated a very ductile flexural beam response accompanied by significant mid-span deflection reaching 27 mm and substantial bar-slip values attaining 19 mm. Different UHP-SFRC mixes, concrete covers, and embedment lengths were considered. A numerical model was developed to simulate the FPBT using a nonlinear finite element analysis platform, VecTor2, with the ability to model this novel concrete. This high bond strength provided by the concrete cover enables a significant reduction in the design development length as compared to what is used today for conventional concrete

Role of IGF-1/IGF-1R in regulation of invasion in DU145 prostate cancer cells

<p>Abstract</p> <p>Background</p> <p>Prostate cancer progression to androgen independence is the primary cause of mortality by this tumor type. The IGF-1/IGF-1R axis is well known to contribute to prostate cancer initiation, but its contribution to invasiveness and the downstream signalling mechanisms that are involved are unclear at present.</p> <p>Results</p> <p>We examined the invasive response of androgen independent DU145 prostate carcinoma cells to IGF-1 stimulation using Matrigel assays. We then examined the signaling mechanisms and protease activities that are associated with this response. IGF-1 significantly increased the invasive capacity of DU145 cells <it>in vitro</it>, and this increase was inhibited by blocking IGF-1R. We further demonstrated that specific inhibitors of the MAPK and PI3-K pathways decrease IGF-1-mediated invasion. To determine potential molecular mechanisms for this change in invasive capacity, we examined changes in expression and activity of matrix metalloproteinases. We observed that IGF-1 increases the enzymatic activity of MMP-2 and MMP-9 in DU145 cells. These changes in activity are due to differences in expression in the case of MMP-9 but not in the case of MMP-2. This observation is corroborated by the fact that correlated changes of expression in a regulator of MMP-2, TIMP-2, were also seen.</p> <p>Conclusion</p> <p>This work identifies a specific effect of IGF-1 on the invasive capacity of DU145 prostate cancer cells, and furthermore delineates mechanisms that contribute to this effect.</p

Comparisons of experimental measurements and large eddy simulations for a helium release in a two vents enclosure.

This work takes place in the context of potential hazards in the use of hydrogen in fuel cells. The present article describes comparisons between PIV measurements performed on a two vented cavity with an helium injection and Large Eddy Simulation of the same configuration. A two vented cavity is chosen because a quasi state is reached rapidly and it facilitates both CFD calculations by reducing the CPU costs and also enables statistical treatment of the data, the temporal averaging being possible at steady state. At the same time, this configuration is close to fuel cell designs, except for the set-up reduced size. We also describe the experimental set-up and the care which has to be taken to produce Particle Image Velocimetry velocity fields. The final goal of the paper is to validate a L.E.S approach as a good replacement to experiments, since access to both velocity and con- centration fields is required to improve existing simplified models. Indeed, most of the 2 vents models rely on simplified assumptions such as a constant entrainment coefficient, a bi-layer formation which is not always the case in real situations

Radiological-pathological correlation in Alzheimer's disease : systematic review of antemortem MRI findings

Background: The standard method of ascertaining Alzheimer’s disease (AD) remains postmortem assessment of amyloid plaques and neurofibrillary degeneration. Vascular pathology, Lewy bodies, TDP-43, and hippocampal sclerosis are frequent comorbidities. There is therefore a need for biomarkers that can assess these aetiologies and provide a diagnosis in vivo. Objective: We conducted a systematic review of published radiological-pathological correlation studies to determine the relationship between antemortem magnetic resonance imaging (MRI) and neuropathological findings in AD. Methods: We explored PubMed in June-July 2015 using “Alzheimer’s disease” and combinations of radiological and pathological terms. After exclusion following screening and full-text assessment of the 552 extracted manuscripts, three others were added from their reference list. In fine, we report results based on 27 articles. Results: Independently of normal age-related brain atrophy, AD pathology is associated with whole-brain and hippocampal atrophy and ventricular expansion as observed on T1-weighted images. Moreover, cerebral amyloid angiopathy and cortical microinfarcts are also related to brain volume loss in AD. Hippocampal sclerosis and TDP-43 are respectively associated with hippocampal and medial temporal lobe atrophy. Brain volume loss correlates more strongly with tangles than with any other pathological finding. White matter hyperintensities observed on proton density, T2-weighted and FLAIR images are strongly related to vascular pathologies, but are also associated with other histological changes such as gliosis or demyelination. Discussion: Cerebral atrophy and white matter changes in the living brain reflect underlying neuropathology and may be detectable using antemortem MRI. In vivo MRI may therefore be an avenue for AD pathological staging

A (im)prescritibilidade das ações de ressarcimento ao erário por conta de atos de improbidade administrativa : uma análise do art. 37, § 5º, da constituição da república

Orientador: Daniel Wunder HachemMonografia (Graduação) - Universidade Federal do Paraná, Setor de Ciências Jurídicas, Curso de Graduação em DireitoResumo: O presente estudo aborda o debate acerca da imprescritibilidade das ações de ressarcimento ao erário nos casos de improbidade administrativa, segundo a exegese do art. 37, § 5º, da Constituição Federal. De início, buscou-se apresentar o princípio da segurança jurídica no cenário brasileiro, bem como demonstrar seu caráter constitucional. Diante de um contexto de instabilidade das relações jurídicas, a ausência de segurança leva à incerteza e a instabilidade nas relações jurídicas. Isto posto, demonstrou-se que no cenário constitucional brasileiro existem três casos em que a imprescritibilidade é expressada de forma inequívoca pelo constituinte: nos crimes de racismo, nos crimes de grupos armados, civis ou militares, contra a ordem constitucional e o Estado Democrático e no direito que as comunidades indígenas possuem à terra que tradicionalmente ocupam. Após, foi analisado os atos que causam dano ao erário público, bem como o papel do Supremo Tribunal Federal no debate, seja através do RE 669.609/MG ou do RE 852.475/SP. Ainda, apontou-se as razões em favor da defesa da prescritibilidade das referidas ações de ressarcimento ao erário, bem como os argumentos elencados pela doutrina contrária. Ao final, conclui-se que a ausência de prazo prescricional para que o Estado ajuíze as ações de ressarcimento viola princípios basilares da Constituição brasileira, quais sejam, os princípios da segurança jurídica e devido processo legal

Highly resolved large eddy simulations of a binary mixture flow in a cavity with two vents: Influence of the computational domain.

In this article, numerical results from a highly resolved large eddy simulations (LES) of an air-helium buoyant jet developing in a two vented cavity are presented. The simulated configuration mimics the helium-release experiment carried out at CEA Saclay in the framework of security assessment of indoor used hydrogen-based systems. The height of the enclosure was chosen so that a laminar-turbulent transition occurs approximately at the middle of the upstream direction. An exterior region, of different spatial dimensions, has been modeled in the computational domain in order to move the boundary conditions away from the vent surface and to approach the natural inlet/outlet conditions. A sensi- tivity analysis regarding the size of the exterior region is presented to define the minimum horizontal extension so that the flow inside the cavity is not furthermore influenced by bigger computational domains. We observe mainly that applying an ambient equilibrium- hydrostatic pressure outlet condition directly on the surface of the vent reduces the vol- ume of the air inflow, and thus predicts larger helium mass inside the cavity, in contrary with the cases where an exterior region is considered. A qualification analysis shows that the sub-grid scale model plays a small role in the calculations and thus implies that the LES predictions approach the direct numerical simulation (DNS) solution. Analysis carried out on the time-averaged helium field depicts a concentration regime that is not classical in such configurations and thus the theoretical model used in safety pre-calculations can not be served

Braak neurofibrillary tangle staging prediction from in vivo MRI metrics

INTRODUCTION: Alzheimer’s disease (AD) diagnosis requires postmortem visualization of amyloid and tau deposits. As brain atrophy can provide assessment of consequent neurodegeneration, our objective was to predict postmortem neurofibrillary tangles (NFT) from in vivo MRI measurements. METHODS: All participants with neuroimaging and neuropathological data from the Alzheimer’s Disease Neuroimaging Initiative, the National Alzheimer’s Coordinating Center and the Rush Memory and Aging Project were selected (n=186). 232 variables were extracted from last MRI before death using FreeSurfer. Nonparametric correlation analysis and multivariable support vector machine classification were performed to provide a predictive model of Braak NFT staging. RESULTS: We demonstrated that 59 of our MRI variables, mostly temporal lobe structures, were significantly associated with Braak NFT stages (p<.005). We obtained a 62.4% correct classification rate for discrimination between transentorhinal, limbic and isocortical groups. DISCUSSION: Structural neuroimaging may therefore be considered as a potential biomarker for early detection of AD-associated neurofibrillary degeneration