2,767 research outputs found
Galactic Outflows and the pollution of the Galactic Environment by Supernovae
We here explore the effects of the SN explosions into the environment of
star-forming galaxies like the Milky Way. Successive randomly distributed and
clustered SNe explosions cause the formation of hot superbubbles that drive
either fountains or galactic winds above the galactic disk, depending on the
amount and concentration of energy that is injected by the SNe. In a galactic
fountain, the ejected gas is re-captured by the gravitational potential and
falls back onto the disk. From 3D nonequilibrium radiative cooling
hydrodynamical simulations of these fountains, we find that they may reach
altitudes up to about 5 kpc in the halo and thus allow for the formation of the
so called intermediate-velocity-clouds (IVCs) which are often observed in the
halos of disk galaxies. The high-velocity-clouds that are also observed but at
higher altitudes (of up to 12 kpc) require another mechanism to explain their
production. We argue that they could be formed either by the capture of gas
from the intergalactic medium and/or by the action of magnetic fields that are
carried to the halo with the gas in the fountains. Due to angular momentum
losses to the halo, we find that the fountain material falls back to smaller
radii and is not largely spread over the galactic disk. Instead, the SNe ejecta
fall nearby the region where the fountain was produced, a result which is
consistent with recent chemical models of the galaxy. The fall back material
leads to the formation of new generations of molecular clouds and to supersonic
turbulence feedback in the disk.Comment: 10 pages, 5 figures; paper of invited talk for the Procs. of the 2007
WISER Workshop (World Space Environment Forum), Alexandria, Egypt, October
2007, Spa. Sci. Rev
12-Year-Old Female with Mucocutaneous Lesions
info:eu-repo/semantics/publishedVersio
Comparability and similarity protocols for biotechnology products
Over lifecycle, from development through all industrialization stages and then over manufacturing history across multiple sites, a biotechnology product must show very high levels of quality consistency, as that is a pre-requisite for safety and efficacy to patients (cf. ICH Q5E, 2004).
Recently, FDA defined different levels of similarity (Draft Guidance, May 2014, “Clinical Pharmacology Data to Support a Demonstration of Biosimilarity to a Reference Product”) namely the concepts of (1) “highly similar with fingerprint-like similarity” and that of (2) “residual uncertainty” in regard to similarity.
Here we present a new approach to combine whole analytical domains from different techniques used in comparability protocols (to support change management for same product and process) that also is applicable to assess similarity in biocomparability investigations.
Our approach ensures much higher levels of confidence in Comparability Protocols by not overlooking differences that might be unnoticed or overlooked due to incomplete prior-knowledge in regards to methods used and attributes considered. Our approach can (a) detect very small differences, (b) establish therefore the exact level of comparability / similarity and (c) provides a sound statistical foundation to assess residual uncertainties. We will illustrate our approach on reference products over their lifecycle and to compare reference with putatively similar products. The outcome of assessments (a) through (c) can then be linked to pharmacological performance or both types of biotechnology products, and support regulatory or other decisions related to managing filings
Characterization of bioactive colored materials produced from bacterial cellulose and bacterial pigments
A Bacterial Cellulose (BC) film was developed and characterized as a potential functional bioactive material. BC films, obtained from a microbial consortium of bacteria and yeast species, were functionalized with the bacterial pigment prodigiosin, produced by Serratia plymuthica, and flexirubin-type pigment, from Chryseobacterium shigense, which exhibit a wide range of biological properties. BC was successfully functionalized at 15% over the weight of the fiber at 40 °C during 60 min, and a color strength of 1.00 ± 0.01 was obtained for BC_prodigiosin and 0.38 ± 0.02 for BC_flexirubin-type pigment. Moreover, the BC films showed moderate hydrophilic character following alkaline treatment, which was maintained after both pigments were incorporated. The porosity and mechanical performance of the functionalized BC samples also remained unaffected. Furthermore, the BC samples functionalized with prodigiosin presented antibacterial activity and were able to inhibit the growth of pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa, with inhibition rates of 97.89 ± 0.60% and 85.12 ± 0.17%, respectively, while BC samples functionalized with flexirubin-type pigment exhibited the highest antioxidant activity, at 38.96 ± 0.49%. This research provides an eco-friendly approach to grant BC film-based material with color and advantageous bioactive properties, which can find application in several fields, especially for medical purposes.This work was funded by the Portuguese Foundation for Science and Technology (FCT), I.P./MCTES through national funds (PIDDAC), in the scope of the FibEnTech Research Unit project (UIDB/00195/2020) and of the 2C2T Research Unit Project (UIDB/00264/2020). L.F.A. Amorim also acknowledges the doctoral fellowship (PD/BD/128417/2017) from Portuguese Foundation for Science and Technology (FCT), co-financed by the European Social Fund (FSE), through the Regional Operational Program of the Center (Centro2020)
Integrating analysis with process control for continuous bioprocessing: Extending the lifecycle concept to process analytical technologies
The most notable trends in the use of PAT tools in bioprocessing nowadays are: (1) the combined use of multiple tools to a product & process and (2) that information fusion provides a better process estimation and product quality knowledge foundation than the use classical use of one analytical method The lifecycle management aspects of validation launched by FDA in its 2011 Validation Guidance, arrived - through ICH Q11 (2012) and the forth coming ICH Q12 (2017), to all aspects of development, qualification and commercial manufacturing of large molecule drug substances. For continuous bioprocessing that challenges are significantly different and more complex than for batch processing of small molecules. The homeostasis state that are targeted for most continuous bioprocesses, puts specific requirements in each individual PAT tool chosen and in their combined use over lifecycle. Here, using case-studies, a discussion is done of specific challenges at each of the three stages of lifecycle, about how and when the shift is made from understanding (acquiring data & information) to enhanced bioprocess control (knowledge-based decisions) to realize product quality by design (predictive product quality). Finally, we show how platform knowledge can be managed across multiple products for a company’s own portfolio benefit, through aggregation and high-level visualization of multiple PAT projects
Ácido ascórbico, betalaínas, e fenóis totais em ecótipos de Opuntia spp.
O género Opuntia spp. pertence à família Cactaceae, sendo a espécie Opuntia ficus-indica (OFI) a que tem maior importância económica. Em frutos de vinte populações provenientes de quatro espécies do género Opuntia spp. (OFI, O. robusta, O. dillenii and O. elata), com origem em Portugal, foram estudadas as características cromáticas, a acidez, o pH, o teor em sólidos solúveis totais (SST) e ainda os teores em ácido ascórbico (AA), betalaínas e fenóis totais (FT). As cultivares Italianas de OFI ‘Bianca’, ‘Gialla’ e ‘Rossa’ foram incluídas como termo de comparação. Os valores mais elevados de acidez foram registados nos frutos de O. dillenii e O. elata e os menores em OFI. Os frutos de O. dillenii apresentaram os teores mais elevados de betalaínas e FT, ao passo que as concentrações mais elevadas de AA foram registadas nos frutos de O. elata. Os ecótipos de OFI mostraram variação na concentração de compostos bioativos. Em OFI, a cv. de polpa vermelha ‘Rossa’ é a que apresenta maior concentração de betalaínas, seguida pelos ecótipos de polpa laranja e, finalmente, os ecótipos de polpa branca. Os valores mais elevados de FT foram encontrados nos ecótipos de polpa branca. O género Opuntia spp. é uma fonte de compostos bioativos, pelo que o consumo dos seus frutos representa uma boa forma de ingestão de compostos de elevado valor nutricional
Layer-by-Layer Deposition of Antibacterial Polyelectrolytes on Cotton Fibres
The introduction of molecules with biological
properties on textile materials is essential for a number of
biotechnological applications. With the purpose of testing
new processes applied to textiles, in this study, we present
the first results on the feasibility of using the Layerby-Layer (LbL) deposition process in natural fibers such as
cotton, with natural polyelectrolytes like chitosan (CH) and
alginic acid sodium salt (ALG), the durability of CH/ALG
multilayer on cotton were evaluated. The increase of negative charges to the substrate cotton was made with NaBr
and TEMPO, to ensure the success of the process of LbL.
Three characterization methods to assess electrostatic LbL
deposition were performed: the contact angle between a
liquid (water) and the sample surface, in order to characterize the wettability of the samples with the different
layers of CH and ALG; dyeing of the CH/ALG assembled
cotton fabric with cationic methylene blue that shows
regular changes in terms of color depth (K/S value), which
indicate that the surface were alternately deposited with
CH and ALG layers and, finally, the analysis by infrared
spectroscopy using Fourier Transform with Attenuated
Total Reflection (ATR-FTIR), to assess the changes in the
interaction between CH and ALG deposited on cotton
samples.info:eu-repo/semantics/publishedVersio
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