Comment on “Faraday waves in a Hele–Shawcell” [Phys. Fluids 30, 042106 (2018)]

Comment on “Faraday waves in a Hele-Shaw cell” [Phys Fluids 30, 042106 (2018).We propose improved dimensionless variables and scaling law to describe the height ofFaraday waves in a vertically vibrating Hele-Shaw cell. In comparison with those suggestedby Li et al., the influence of the liquid depth d on the wave height H is disregarded, andthe critical acceleration Fc, at which the Faraday instability is triggered, is now taken intoaccount. We support our approach with results from an additional set of experimental data,that includes the measurement of Fc, and encompasses the parameter range studied by Liet al.Fil: Boschan, A.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Noseda, M.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; ArgentinaFil: Aguirre, Maria Alejandra. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Piva, M.. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Física. Grupo de Medios Porosos; Argentin

Enhanced efficiency of genetic programming toward cardiomyocyte creation through topographical cues

AbstractGeneration of de novo cardiomyocytes through viral over-expression of key transcription factors represents a highly promising strategy for cardiac muscle tissue regeneration. Although the feasibility of cell reprogramming has been proven possible both in vitro and in vivo, the efficiency of the process remains extremely low. Here, we report a chemical-free technique in which topographical cues, more specifically parallel microgrooves, enhance the directed differentiation of cardiac progenitors into cardiomyocyte-like cells. Using a lentivirus-mediated direct reprogramming strategy for expression of Myocardin, Tbx5, and Mef2c, we showed that the microgrooved substrate provokes an increase in histone H3 acetylation (AcH3), known to be a permissive environment for reprogramming by “stemness” factors, as well as stimulation of myocardin sumoylation, a post-translational modification essential to the transcriptional function of this key co-activator. These biochemical effects mimicked those of a pharmacological histone deacetylase inhibitor, valproic acid (VPA), and like VPA markedly augmented the expression of cardiomyocyte-specific proteins by the genetically engineered cells. No instructive effect was seen in cells unresponsive to VPA. In addition, the anisotropy resulting from parallel microgrooves induced cellular alignment, mimicking the native ventricular myocardium and augmenting sarcomere organization

Insight Report: Online public involvement session on proposed cardiovascular research programmes

A group of researchers across Imperial College London (some of whom are also part of the Imperial Biomedical Research Centre (BRC)) are applying for £5 million funding over 5 years from the British Heart Foundation (BHF) to fund a BHF Centre for Research Excellence at Imperial to support research on various aspects of cardiovascular medicine. The four research themes the funding proposal will cover are as follows: 1. Societal and Environmental Factors 2. Learning from Heart Patients 3. Vascular Ageing (Blood vessels) 4. Remote (at home) personal monitorin

Multi-modal hydrogel-based platform to deliver and monitor cardiac progenitor/stem cell engraftment

Retention and survival of transplanted cells are major limitations to the efficacy of regenerative medicine, with short-term paracrine signals being the principal mechanism underlying current cell therapies for heart repair. Consequently, even improvements in short-term durability may have a potential impact on cardiac cell grafting. We have developed a multimodal hydrogel-based platform comprised of a poly(ethylene glycol) network cross-linked with bioactive peptides functionalized with Gd(III) in order to monitor the localization and retention of the hydrogel in vivo by magnetic resonance imaging. In this study, we have tailored the material for cardiac applications through the inclusion of a heparin-binding peptide (HBP) sequence in the cross-linker design and formulated the gel to display mechanical properties resembling those of cardiac tissue. Luciferase-expressing cardiac stem cells (CSC-Luc2) encapsulated within these gels maintained their metabolic activity for up to 14 days in vitro. Encapsulation in the HBP hydrogels improved CSC-Luc2 retention in the mouse myocardium and hind limbs at 3 days by 6.5- and 12- fold, respectively. Thus, this novel heparin-binding based, Gd(III)-tagged hydrogel and CSC-Luc2 platform system demonstrates a tailored, in vivo detectable theranostic cell delivery system that can be implemented to monitor and assess the transplanted material and cell retention

Co-culture of microalgae, cyanobacteria, and macromycetes for exopolysaccharides production: process preliminary optimization and partial characterization.

In this study, the biomass and exopolysaccharides (EPS) production in co-cultures of microalgae/cyanobacteria and macromycetes was evaluated as a technology for producing new polysaccharides for medical and/or industrial application. Based on biomass and EPS productivity of monocultures, two algae and two fungi were selected and cultured in different co-culture arrangements. The hydrosoluble EPS fractions from mono- and cocultures were characterized by ¹³C NMR spectroscopy and gas chromatography coupled to mass spectrometry and compared. It was found that co-cultures resulted in the production of an EPS different from those produced by monocultures, showing fungal predominance with microalgal/cyanobacterial traces. Co-cultures conditions were screened (temperature, agitation speed, fungal and microalgae inoculation rate, initial pH, illumination rate, and glucose concentration) in order to achieve maximum biomass and EPS production, resulting in an increase of 33 and 61% in exopolysaccharides and biomass productions, respectively (patent pending)

Towards Multidisciplinary HIV-Cure Research: Integrating Social Science with Biomedical Research

The quest for a cure for HIV remains a timely and key challenge for the HIV research community. Despite significant scientific advances, current HIV therapy regimens do not completely eliminate the negative impact of HIV on the immune system; and the economic impact of treating all people infected with HIV globally, for the duration of their lifetimes, presents significant challenges. This article discusses, from a multi-disciplinary approach, critical social, behavioral, ethical, and economic issues permeating the HIV cure research agenda. As part of a search for an HIV cure, both the perspective of patients/participants and clinical researchers should be taken into account. In addition, continued efforts should be made to involve and educate the broader community

Chemical structure and biological activity of the (1 → 3)-linked β-D-glucan isolated from marine diatom Conticribra weissflogii

Several polysaccharides are considered to be "biological response modifiers" (BRM) - these refer to biomolecules that augment immune responses and can be derived from a variety of sources. Microalgae produce a diverse range of polysaccharides and could be an excellent source of BRM. Here, we describe the chemical structure and biological activity of water-soluble polysaccharide isolated from the marine diatom Conticribra weissflogii. Using chemical and NMR spectroscopic methods, the polysaccharide was identified as a (1 → 3)-linked β-D-glucan with a low proportion of C-6 substitution by single β-glucose units. The biological activity of this low molecular weight β-glucan (11.7 kDa) was investigated with respect to glioblastoma cell lines (U87 MG and U251) and macrophages (RAW 264.7). We observed that this β-D-glucan did not exhibit cytotoxic activity against glioblastoma cells, but did enhance the phagocytic activity of macrophages, suggesting that it possesses immunomodulatory properties.</p

AVALIAÇÃO DA PRODUÇÃO DE METIL-GALACTOPIRANOSÍDEOS NA GLICOSIDAÇÃO DE FISCHER:: INFLUÊNCIA DE CATALISADORES ÁCIDOS HETEROGÊNEOS

A glicosidação de Fischer foi o primeiro método desenvolvido para a síntese de alquil-piranosídeos e é considerado um dos métodos mais econômicos. Porém, o piranosídeo majoritário desta reação, quando se parte da D-galactose, é o metil-α-Galp. Tendo em conta o alto custo do metil-β-Galp, sua importância no mercado de química fina e as vantagens da glicosidação de Fischer, este trabalho teve por objetivo estudar a influência dos catalisadores ácidos heterogêneos na produção de metil-Galps na glicosidação de Fischer, reagindo a galactose com o metanol na presença de diferentes catalisadores ácidos heterogêneos(sílica-ácido-sulfúrico, sílica-ácido-clorossulfónico, alumina sulfúrica e resina catiônica AMBERLITE-IR-120), em diferentes tempos de reação e diferentes temperaturas. O estudo foi realizado em duas etapas. Na etapa I, todos os catalisadores acima citados, foram avaliados nas mesmas condições reacionais. Os principais resultados obtidos nesta etapa, foram otimizados na etapa II, em diferentes condições reacionais, com o uso de ultrassom, quantidades adicionais de água, metanol desidratado e molecular sieives. Os parâmetros que mais contribuiram para os resultados, foram o tempo de reação e temperatura. Os melhores resultados foram obtidos com a sílica-ácido sulfúrico e sílica-ácido clorossulfônico, na temperatura de 64,7ºC. Na temperatura ambiente, o percentual de metil-Galps foi baixíssimo. Ainda na temperatura de 64,7ºC, a maior produção de metil-Galps foi obtida entre 48 h - 72 h, com algumas exceções. Os melhores resultados do estudo, foram obtidos com os catalisadores sílica-ácido sulfúrico em 48 h (56%metil-α-Galp/43%metil-β-Galp) e sílica-ácido clorossulfônico em 5 h (26%metil-α-Galp/33%metil-β-Galp)