394 research outputs found
Erratum to: Mechano-Transduction Signals Derived from Self-Assembling Peptide Nanofibers Containing Long Motif of Laminin Influence Neurogenesis in In-Vitro and In-Vivo (Mol Neurobiol, 10.1007/s12035-016-9836-z)
Astroglial scaring and limited neurogenesis are two problematic issues in recovery of spinal cord injury (SCI). In the meantime, it seems that mechanical manipulations of scaffold to inhibit astroglial scarring and improve neurogenesis is worthy of value. In the present investigation, the effect of nanofiber (gel) concentration as a mechanical-stimuli in neurogenesis was investigated. Cell viability, membrane damage, and neural differentiation derived from endometrial stem cells encapsulated into self-assembling peptide nanofiber containing long motif of laminin were assessed. Then, two of their concentrations that had no significant difference of neural differentiation potential were selected for motor neuron investigation in SCI model of rat. MTT assay data showed that nanofibers at the concentrations of 0.125 and 0.25 % w/v induced higher and less cell viability than others, respectively, while cell viability derived from higher concentrations of 0.25 % w/v had ascending trend. Gene expression results showed that noggin along with laminin motif over-expressed TH gene and the absence of noggin or laminin motif did not in all concentrations. Bcl2 over-expression is concomitant with the decrease of nanofiber stiffness, NF+ cells increment, and astrogenesis inhibition and dark neuron decrement in SCI model. It seems that stiffness affects on Bcl2 gene expression and may through β-Catenin/Wnt signaling pathway and BMP-4 inhibition decreases astrogenesis and improves neurogenesis. However, stiffness had a significant effect on upregulation of GFAP+ cells and motor neuron recovery in in vivo. It might be concluded that eventually there is a critical definitive point concentration that at less or higher than of it changes cell behavior and neural differentiation through different molecular pathways
Angiotensin-converting enzyme inhibitors and cytokines in heart failure: dose and effect?∗∗Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology.
Tyrosine hydroxylase (TH), a rate-limiting step in catecholamine synthesis in which its activity influences Alzheimer disease, Parkinson disease, and IQ of schizophrenia patients, has been studied for a long time. In the meantime, the present investigation assessed the effect of noggin and type of self-assembling nanofibers in TH gene over-expression by neuron-like cells derived from human endometrial-derived stromal cells (hEnSCs). Neuroblastoma cells and hEnSCs encapsulated into nanofibers including Matrigel, (RADA)4, laminin, and BMHP-1 motif bounded to (RADA)4 and their cell viability were studied for 48 h and 18 days in basal and neurogenic media, respectively, in noggin-rich media. Then, expression of neural genes and proteins has been investigated by immunocytochemistry (ICC) and real-time PCR methods, respectively. The results indicated that neuroblastoma cell and hEnSC viability is in good agreement with the level of Bcl2 and β-tubulin III gene expression; however, -BMHP-1 and -laminin nanofibers exhibited significantly higher cell viability eventually through Wnt/β-catenin signaling pathway as compared to others, respectively. The gene expression analysis of nanofibers showed that none of them induced gamma-aminobutyric acid (GABA) gene expression while glial fibrillary acidic protein (GFAP) gene just over-expressed in cells encapsulated into Matrigel with a low level of Bcl2 gene expression. However, the TH gene just had been over-expressed in cells encapsulated into -laminin nanofiber and 2D cell culture. In the absence of noggin with -laminin nanofibers, TH gene expression was suppressed. It might be concluded that although noggin through anti-BMP pathways resulted in GFAP decrement and TH gene increment, the type of scaffold that defined the final fate of cells and -laminin accompaniment might be useful for the recovery of Alzheimer and Parkinson disease patients. © 2016 Springer Science+Business Media New Yor
The Local Shape of the Universe in the Inflationary Limit
Recent high precision data by WMAP and SDSS have provided strong evidence to
suggest that the universe is nearly flat. They are also making it possible to
probe the topology of the universe. Motivated by these results, we have
recently studied the consequences of taking the inflationary limit, i.e.
. We have shown that in this limit a generic detectable
spherical or hyperbolic topology is locally indistinguishable from either or , irrespective of its global shape. Here we briefly present
these results and further discuss their observational implications.Comment: To appear in Int J. Mod. Phys A (2005), Latex 2e. World Scientific
proc. style files, 1 fig, 6 pages. Typos correcte
Consequences of Observational Uncertainties on the Detection of Cosmic Topology
The observed values of density parameters inevitably involve uncertainties.
We study the conditions for detectability and undetectability of cosmic
topology in presence of such uncertainties. We present closed analytical forms
of (un)detectability conditions for infinite redshift, which are important
because: (i) they allow the examine of the detectability of cosmic topology not
only for individual manifolds (topologies), but also in whole classes of
manifolds; (ii) they are, to a very good approximation, (un)detectibility
conditions for z=1100.Comment: To appear in the Proc. of 10th Marcel Grossmann Meeting on General
Relativity. Latex2e, World Scientific proc. style files, 1 fig., 4 page
The impact of the particle size of curcumin nanocarriers and the ethanol on beta1-integrin overexpression in fibroblasts: A regenerative pharmaceutical approach in skin repair and anti-aging formulations
Background: Since women pay more attention to their skin�s health, pharmaceutical companies invest heavily on skin care product development. Further, the success of drug nano-carriers in passing through the skin justifies the need to conduct studies at the nano-scale. β1-integrin down regulation has been proposed as a sign of skin aging. Methods: Six drug nano-carriers (50 and 75 nm) were prepared at three ethanol concentrations (0, 3,and 5) and different temperatures. Then, the impact of Nanocarriers on fibroblasts were investigated. Results: DLS showed that increasing ethanol concentration decreased the surface tension that caused a decrease in the particle size in non-temperature formulations while increasing the temperature to 60 °C to lower Gibbs free energy increased the particle size. Ethanol addition decreased β1-integrin over-expression, whereas larger nano-carriers induced an over-expression of β1-integrin, Bcl2/Bax ratio, and an increase in live cell number. β1-integrin over-expression did not correlate with the rate of fibroblast proliferation and NFκB expression. An increase in fibroblast mortality in relation to smaller nano-carriers was not only due to the increase in Bax ratio, but was related to NFκB over-expression. Conclusion: The development of a regenerative pharmaceutical approach in skin repair was based on the effect of particle size and ethanol concentration of the drug nano-carriers on the expression of β1-integrin in fibroblasts. A curcumin nanoformulation sized 77 nm and containing of 3 ethanol was more effective in increasing β1-integrin gene over-expression, anti-apoptosis of fibroblast cells (Bcl2/Bax ratio), and in decreasing Bax and NFκB gene expression than that with a particle size of 50 nm. Such a formulation may be considered a valuable candidate in anti-aging and wound-healing formulations. Figure not available: see fulltext.. © 2019, Springer Nature Switzerland AG
Evolution of the density contrast in inhomogeneous dust models
With the help of families of density contrast indicators, we study the
tendency of gravitational systems to become increasingly lumpy with time.
Depending upon their domain of definition, these indicators could be local or
global. We make a comparative study of these indicators in the context of
inhomogeneous cosmological models of Lemaitre--Tolman and Szekeres. In
particular, we look at the temporal asymptotic behaviour of these indicators
and ask under what conditions, and for which class of models, they evolve
monotonically in time. We find that for the case of ever-expanding models,
there is a larger class of indicators that grow monotonically with time,
whereas the corresponding class for the recollapsing models is more restricted.
Nevertheless, in the absence of decaying modes, indicators exist which grow
monotonically with time for both ever-expanding and recollapsing models
simultaneously. On the other hand, no such indicators may found which grow
monotonically if the decaying modes are allowed to exist. We also find the
conditions for these indicators to be non-divergent at the initial singularity
in both models. Our results can be of potential relevance for understanding
structure formation in inhomogeneous settings and in debates regarding
gravitational entropy and arrow of time. In particular, the spatial dependence
of turning points in inhomogeneous cosmologies may result in multiple density
contrast arrows in recollapsing models over certain epochs. We also find that
different notions of asymptotic homogenisation may be deduced, depending upon
the density contrast indicators used.Comment: 22 pages, 1 figure. To be published in Classical and Quantum Gravit
A note on the large-angle anisotropies in the WMAP cut-sky maps
Recent analyses of the WMAP data seem to indicate the possible presence of
large-angle anisotropy in the Universe. If confirmed, these can have important
consequences for our understanding of the Universe. A number of attempts have
recently been made to establish the reality and nature of such anisotropies in
the CMB data. Among these is a directional indicator recently proposed by the
authors. A distinctive feature of this indicator is that it can be used to
generate a sky map of the large-scale anisotropies of the CMB maps. Applying
this indicator to full-sky temperature maps we found a statistically
significant preferred direction. The full-sky maps used in these analyses are
known to have residual foreground contamination as well as complicated noise
properties. Thus, here we performed the same analysis for a map where regions
with high foreground contamination were removed. We find that the main feature
of the full-sky analysis, namely the presence of a significant axis of
asymmetry, is robust with respect to this masking procedure. Other subtler
anomalies of the full-sky are on the other hand no longer present.Comment: 10 pages, 3 figeres. We performed a similar analysis of
arXiv:astro-ph/0511666 by considering the LILC map with a Kp2 sky cut, and
find that the presence of a significant axis of asymmetry is robust with
respect to this masking procedur
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