Our aim was to study Brazilian consumer attitudes towards cell-based meat and related issues. From 408 respondents from Curitiba and 218 from Joinville, the majority was women with higher level of ...education; 65.2% and 70.2% frequently consumed meat and 50.7% and 50.9% would not stop eating meat; 81.6% and 82.6% had little or no knowledge about cell-based meat. After watching an explanatory video, 41.9% and 34.4% stated they would eat cell-based meat without restrictions; 24.5% and 23.9% stated they would try depending on conditionals. Overall, 63.6% declared they would eat cell-based meat; among vegetarians and vegans, 24% and 8% stated they would eat cell-based meat, with additional 25.0% and 27.0% stating "it depends"; thus, the major public for cell-based meat seems to be meat eaters. Animal welfare was the principal reason for considering not eating meat and a major benefit of cell-based meat. In conclusion, the majority of respondents would not stop eating meat; additionally, they would eat cell-based meat.
•Magneto-responsive devices for cancer theranostics are reviewed.•Magnetic nanoparticles are used for cancer diagnostic through MRI.•Magnetic nanoparticles are clinically approved for magnetic ...hyperthermia application.•1D and 2D magnetic nanosystems have huge potential for cancer theranostics.•3D and 4D magnetic nanosystems still need further study and optimization.
Design, research, and development of new and improved smart multifunctional devices is one of the main topics in the advanced functional materials agenda for the next decade. Smart materials that can be triggered by external stimuli are seen with high potential for innovative treatments and improved drug delivery systems by regulatory agencies like the FDA and EMA. The incorporation of magnetic nanostructures into complex systems produces multifunctional devices that can be spatiotemporally controlled by an external magnetic field. These magneto-responsive devices can be used for a multitude of biomedical applications, from diagnostic to the treatment of tumors, and are actively being developed and tested for cancer theranostics. Herein, we review the development of magneto-responsive devices for cancer theranostics, starting from the most straightforward architecture, single nanoparticles. We give some theoretical concepts about the design and production of such systems while providing a critical review of applications in clinical practice. Naturally, the review evolves to more complex architectures, from one-dimensional to three-dimensional magneto-responsive systems, demonstrating higher complexity and multifunctionality, and consequently, higher interest for clinical practice. The review ends with the main challenges in the design and engineering of magneto-responsive devices for cancer theranostics and future trends in this biomedical field.
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•Superparamagnetic iron oxide nanoparticles with 9nm were produced.•Three different surfactants (oleic acid, sodium citrate, and Triton X-100) were tested.•Surfactants presence on the ...nanoparticles was confirmed by InfraRed analysis.•Oleic acid exhibits a good performance as stabilizer for concentrations above 64mM.•Apart from oleic acid, surfactants do not significantly affect magnetic properties.
Iron oxide nanoparticles are having been extensively investigated for several biomedical applications such as hyperthermia and magnetic resonance imaging. However, one of the biggest problems of these nanoparticles is their aggregation.
Taking this into account, in this study the influence of three different surfactants (oleic acid, sodium citrate and Triton X-100) each one with various concentrations in the colloidal solutions stability was analyzed by using a rapid and facile method, the variation in the optical absorbance along time.
The synthesized nanoparticles through chemical precipitation showed an average size of 9nm and a narrow size distribution. X-ray diffraction pattern and Fourier Transform Infrared analysis confirmed the presence of pure magnetite. SQUID measurements showed superparamagnetic properties with a blocking temperature around 155K. In addition it was observed that neither sodium citrate nor Triton X-100 influences the magnetic properties of the nanoparticles. On the other hand, oleic acid in a concentration of 64mM decreases the saturation magnetization from 67 to 45emu/g. Oleic acid exhibits a good performance as stabilizer of the iron oxide nanoparticles in an aqueous solution for 24h, for concentrations that lead to the formation of the double layer.
•Chitosan is widely used for biomedical applications.•Chitosan-iron oxide nanoparticles are suitable for magnetic hyperthermia.•Chitosan coating does not affect the properties of iron oxide ...nanoparticles.•Chitosan-iron oxide nanoparticles have a nanometric hydrodynamic diameter.
Chitosan is a biopolymer widely used for biomedical applications such as drug delivery systems, wound healing, and tissue engineering. Chitosan can be used as coating for other types of materials such as iron oxide nanoparticles, improving its biocompatibility while extending its range of applications.
In this work iron oxide nanoparticles (Fe3O4 NPs) produced by chemical precipitation and thermal decomposition and coated with chitosan with different molecular weights were studied. Basic characterization on bare and chitosan-Fe3O4 NPs was performed demonstrating that chitosan does not affect the crystallinity, chemical composition, and superparamagnetic properties of the Fe3O4 NPs, and also the incorporation of Fe3O4 NPs into chitosan nanoparticles increases the later hydrodynamic diameter without compromising its physical and chemical properties. The nano-composite was tested for magnetic hyperthermia by applying an alternating current magnetic field to the samples demonstrating that the heating ability of the Fe3O4 NPs was not significantly affected by chitosan.
ABSTRACT
We assess the performance of the multipole expansion formalism in the case of single-dish H i intensity mapping, including instrumental and foreground removal effects. This formalism is used ...to provide Markov chain Monte Carlo forecasts for a range of H i and cosmological parameters, including redshift space distortions and the Alcock–Paczynski effect. We first determine the range of validity of our power spectrum modelling by fitting to simulation data, concentrating on the monopole, quadrupole, and hexadecapole contributions. We then show that foreground subtraction effects can lead to severe biases in the determination of cosmological parameters, in particular the parameters relating to the transverse Baryon Acoustic Oscillations (BAO) rescaling, the growth rate, and the H i bias (α⊥, $\overline{T}_\rm{H{\small I}}f\sigma _8$, and $\overline{T}_{\mathrm {H}\,{\small I}}b_{\mathrm {H}\,{\small I}}\sigma _8$, respectively). We attempt to account for these biases by constructing a two-parameter foreground modelling prescription, and find that our prescription leads to unbiased parameter estimation at the expense of increasing the estimated uncertainties on cosmological parameters. In addition, we confirm that instrumental and foreground removal effects significantly impact the theoretical covariance matrix, and cause the covariance between different multipoles to become non-negligible. Finally, we show the effect of including higher order multipoles in our analysis, and how these can be used to investigate the presence of instrumental and systematic effects in H i intensity mapping data.
ABSTRACT
We determine the cosmic abundance of molecular hydrogen (H2) in the local Universe from the xCOLD GASS survey. To constrain the H2 mass function at low masses and correct for the effect of ...the lower stellar mass limit of $10^9 \, \mathrm{M}_{\odot }$ in the xCOLD GASS survey, we use an empirical approach based on an observed scaling relation between star formation rate and gas mass. We also constrain the H i and H i+H2 mass functions using the xGASS survey and compare them to the H i mass function from the ALFALFA survey. We find the cosmic abundance of molecular gas in the local Universe to be $\Omega _{\mathrm{H_2}} = (5.34 \pm 0.47) \times 10^{-5} h^{-1}$. Molecular gas accounts for $19.6\pm 3.9{{\ \rm per\ cent}}$ of the total abundance of cold gas, $\mathrm{\Omega _{H\,{\small I}+H_{2}}} = (4.66 \pm 0.70) \times 10^{-4}\, h_{70}^{-1}$. Galaxies with stellar masses in excess of 109$\, \mathrm{M}_{\odot }$ account for 89 per cent of the molecular gas in the local Universe, while in comparison such galaxies only contain 73 per cent of the cold atomic gas as traced by the H i 21cm line. The xCOLD GASS CO, molecular gas and cold gas mass functions, and $\Omega _{\mathrm{H_2}}$ measurements provide constraints for models of galaxy evolution and help to anchor blind molecular gas surveys attempting to determine the abundance of molecular gas at high redshifts.
ABSTRACT
We apply for the first time Gaussian Process Regression (GPR) as a foreground removal technique in the context of single-dish, low redshift H i intensity mapping, and present an open-source ...python toolkit for doing so. We use MeerKAT and SKA1-MID-like simulations of 21 cm foregrounds (including polarization leakage), H i cosmological signal, and instrumental noise. We find that it is possible to use GPR as a foreground removal technique in this context, and that it is better suited in some cases to recover the H i power spectrum than principal component analysis (PCA), especially on small scales. GPR is especially good at recovering the radial power spectrum, outperforming PCA when considering the full bandwidth of our data. Both methods are worse at recovering the transverse power spectrum, since they rely on frequency-only covariance information. When halving our data along frequency, we find that GPR performs better in the low-frequency range, where foregrounds are brighter. It performs worse than PCA when frequency channels are missing, to emulate RFI flagging. We conclude that GPR is an excellent foreground removal option for the case of single-dish, low-redshift H i intensity mapping in the absence of missing frequency channels. Our python toolkit gpr4im and the data used in this analysis are publicly available on GitHub.
ABSTRACT
We present a framework and an open-source python toolkit to analyse the two-point statistics of 3D fluctuations in the context of H i intensity maps using the multipole expansion formalism. ...We include simulations of the cosmological H i signal using N-body and lognormal methods, foregrounds and their removal, as well as instrumental effects. Using these simulations and analytical modelling, we investigate the impact of foreground cleaning and the instrumental beam on the power spectrum multipoles as well as on the Fourier space clustering wedges. We find that both the instrumental beam and the foreground removal can produce a quadrupole (and a hexadecapole) signal, and demonstrate the importance of controlling and accurately modelling these effects for precision radio cosmology. We conclude that these effects can be modelled with reasonable accuracy using our multipole expansion technique. We also perform a Markov Chain Monte Carlo (MCMC) analysis to showcase the effect of foreground cleaning on the estimation of the H i abundance and bias parameters. The accompanying python toolkit is available at https://github.com/IntensityTools/MultipoleExpansion, and includes an interactive suite of examples to aid new users.
The mTOR signalling pathway in human cancer Pópulo, Helena; Lopes, José Manuel; Soares, Paula
International Journal of Molecular Sciences,
02/2012, Volume:
13, Issue:
2
Journal Article, Book Review
Peer reviewed
Open access
The conserved serine/threonine kinase mTOR (the mammalian target of rapamycin), a downstream effector of the PI3K/AKT pathway, forms two distinct multiprotein complexes: mTORC1 and mTORC2. mTORC1 is ...sensitive to rapamycin, activates S6K1 and 4EBP1, which are involved in mRNA translation. It is activated by diverse stimuli, such as growth factors, nutrients, energy and stress signals, and essential signalling pathways, such as PI3K, MAPK and AMPK, in order to control cell growth, proliferation and survival. mTORC2 is considered resistant to rapamycin and is generally insensitive to nutrients and energy signals. It activates PKC-α and AKT and regulates the actin cytoskeleton. Deregulation of multiple elements of the mTOR pathway (PI3K amplification/mutation, PTEN loss of function, AKT overexpression, and S6K1, 4EBP1 and eIF4E overexpression) has been reported in many types of cancers, particularly in melanoma, where alterations in major components of the mTOR pathway were reported to have significant effects on tumour progression. Therefore, mTOR is an appealing therapeutic target and mTOR inhibitors, including the rapamycin analogues deforolimus, everolimus and temsirolimus, are submitted to clinical trials for treating multiple cancers, alone or in combination with inhibitors of other pathways. Importantly, temsirolimus and everolimus were recently approved by the FDA for the treatment of renal cell carcinoma, PNET and giant cell astrocytoma. Small molecules that inhibit mTOR kinase activity and dual PI3K-mTOR inhibitors are also being developed. In this review, we aim to survey relevant research, the molecular mechanisms of signalling, including upstream activation and downstream effectors, and the role of mTOR in cancer, mainly in melanoma.
Energy security and environmental concerns, related to the increasing carbon emissions, have prompted in the last years the search for renewable and sustainable fuels. Biodiesel, a mixture of fatty ...acids alkyl esters shows properties, which make it a feasible substitute for fossil diesel. Biodiesel can be produced using different processes and different raw materials. The most common, first generation, biodiesel is produced by methanolysis of vegetable oils using basic or acid homogeneous catalysts. The use of vegetable oils for biodiesel production raises serious questions about biodiesel sustainability. Used cooking oils and animal fats can replace the vegetable oils in biodiesel production thus allowing to produce a more sustainable biofuel. Moreover, methanol can be replaced by ethanol being totally renewable since it can be produced by biomass fermentation. The substitution of homogeneous catalyzed processes, nowadays used in the biodiesel industry, by heterogeneous ones can contribute to improve the biodiesel sustainability with simultaneous cost reduction. From the existing literature on biodiesel production, it stands out that several strategies can be adopted to improve the sustainability of biodiesel. A literature review is presented to underline the strategies allowing to improve the biodiesel sustainability.
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