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171.
Hernández-Ledesma Ana Laura Rodríguez-Méndez Adriana Jheny Gallardo-Vidal Lilia Susana García-Gasca Teresa Alatorre-Cruz Julia María García-Solís Pablo López Reyes Julián Solís-Saínz Juan Carlos 《Molecular biology reports》2020,47(12):9667-9676
Molecular Biology Reports - Although cognitive impairment (CI) is classically associated with aging, it has been proposed that neurological pathologies may increase the risk to suffer CI. Despite... 相似文献
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Julia S. Markl Werner E. G. Müller Dayane Sereno Tarek A. Elkhooly Maria Kokkinopoulou Johan Gardères Frank Depoix Matthias Wiens 《Biotechnology and bioengineering》2020,117(6):1789-1804
During evolution, sponges (Porifera) have honed the genetic toolbox and biosynthetic mechanisms for the fabrication of siliceous skeletal components (spicules). Spicules carry a protein scaffold embedded within biogenic silica (biosilica) and feature an amazing range of optical, structural, and mechanical properties. Thus, it is tempting to explore the low-energy synthetic pathways of spiculogenesis for the fabrication of innovative hybrid materials. In this synthetic biology approach, the uptake of multifunctional nonbiogenic nanoparticles (fluorescent, superparamagnetic) by spicule-forming cells of bioreactor-cultivated sponge primmorphs provides access to spiculogenesis. The ingested nanoparticles were detected within intracellular vesicles resembling silicasomes (silica-rich cellular compartments) and as cytosolic clusters where they lent primmorphs fluorescent/magnetic properties. During spiculogenesis, the nanoparticles initially formed an incomplete layer around juvenile, intracellular spicules. In the mature, extracellular spicules the nanoparticles were densely arranged as a surface layer that rendered the resulting composite fluorescent and magnetic. By branching off the conventional route of solid-state materials synthesis under harsh conditions, a new pathway has been opened to a versatile platform that allows adding functionalities to growing spicules as templates in living cells, using nonbiogenic nanoscale building blocks with multiple functionalities. The magnet-assisted alignment renders this composite with its fluorescent/magnetic properties potentially suitable for application in biooptoelectronics and microelectronics (e.g., microscale on-chip waveguides for applications of optical detection and sensing). 相似文献
175.
Ernetti Julia R. Boschetti Joana P. Delazeri Francieli De Bastiani Veluma I. M. Pontes Mariana R. Ribeiro Luisa P. Lingnau Rodrigo Toledo Luís Felipe Lucas Elaine M. 《Hydrobiologia》2020,847(16):3355-3364
Hydrobiologia - Pithecopus rusticus is an endemic amphibian restricted to the type locality, in southern Brazil, and possibly endangered to extinction, due to habitat degradation. However, an... 相似文献
176.
Pedro M. F. Sousa Marco A. M. Videira Thomas Vorburger Sara T. N. Silva James W. Moir Julia Steuber Ana M. P. Melo 《Archives of microbiology》2013,195(3):211-217
Neisseria meningitidis is a pathogenic bacterium responsible for meningitis. The mechanisms underlying the control of Na+ transmembrane movement, presumably important to pathogenicity, have been barely addressed. To elucidate the function of the components of the Na+ transport system in N. meningitidis, an open reading frame from the genome of this bacterium displaying similarity with the NhaE type of Na+/H+ antiporters was expressed in Escherichia coli and characterized for sodium transport ability. The N. meningitidis antiporter (NmNhaE) was able to complement an E. coli strain devoid of Na+/H+ antiporters (KNabc) respecting the ability to grow in the presence of NaCl and LiCl. Ion transport assays in everted vesicles prepared from KNabc expressing NmNhaE from a plasmid confirmed its ability to translocate Na+ and Li+. Here is presented the characterization of the first NhaE from a pathogen, an important contribution to the comprehension of sodium ion metabolism in this kind of microorganisms. 相似文献
177.
A volume-penalizing immersed boundary method is presented for the simulation of laminar incompressible flow inside geometrically complex blood vessels in the human brain. We concentrate on cerebral aneurysms and compute flow in curved brain vessels with and without spherical aneurysm cavities attached. We approximate blood as an incompressible Newtonian fluid and simulate the flow with the use of a skew-symmetric finite-volume discretization and explicit time-stepping. A key element of the immersed boundary method is the so-called masking function. This is a binary function with which we identify at any location in the domain whether it is ‘solid’ or ‘fluid’, allowing to represent objects immersed in a Cartesian grid. We compare three definitions of the masking function for geometries that are non-aligned with the grid. In each case a ‘staircase’ representation is used in which a grid cell is either ‘solid’ or ‘fluid’. Reliable findings are obtained with our immersed boundary method, even at fairly coarse meshes with about 16 grid cells across a velocity profile. The validation of the immersed boundary method is provided on the basis of classical Poiseuille flow in a cylindrical pipe. We obtain first order convergence for the velocity and the shear stress, reflecting the fact that in our approach the solid-fluid interface is localized with an accuracy on the order of a grid cell. Simulations for curved vessels and aneurysms are done for different flow regimes, characterized by different values of the Reynolds number ( $Re$ ). The validation is performed for laminar flow at $Re=250$ , while the flow in more complex geometries is studied at $Re = 100$ and $Re = 250$ , as suggested by physiological conditions pertaining to flow of blood in the circle of Willis. 相似文献
178.
Norbert Pfeiffer Julia Lamparter Adrian Gericke Franz H. Grus Esther M. Hoffmann Jochen Wahl 《Cell and tissue research》2013,353(2):245-251
Intraocular pressure (IOP)-lowering therapy has been shown to arrest or retard the progression of optic neuropathy typical for glaucoma and can, thus, be described as neuroprotective. At present, six classes of medical therapy are employed, namely parasympathomimetics, alpha/beta-sympathomimetics, β-blockers, carbonic anhydrase inhibitors, α2-adrenergic receptor agonists and prostaglandin analogues. For several of these substances, some experimental evidence exists of a possible neuroprotective mechanism, beyond their IOP-lowering activity. β-Blockers are involved in the up-regulation of brain-derived neurotrophic factor (BDNF) and can decrease glutamate-mediated NMDA receptor activation. Not only systemic but also topical carbonic anhydrase inhibitors are able to increase retinal blood flow. α2-Adrenergic receptor agonists can up-regulate the formation of BDNF and anti-apoptotic factors. Prostaglandin analogues increase blood flow to the eye, possibly including the retina. To date, evidence for a neuroprotective effect independent of IOP regulation in human glaucoma is scarce and has only been shown to be likely for the α2-adrenergic receptor agonist, brimonidine. 相似文献
179.
N. Belén Rumie Vittar María Julia Lamberti María Florencia Pansa Renzo E. Vera M. Exequiel RodriguezI. Sol Cogno Laura N. Milla SanabriaViviana A. Rivarola 《生物化学与生物物理学报:癌评论》2013
As with natural ecosystems, species within the tumor microenvironment are connected by pairwise interactions (e.g. mutualism, predation) leading to a strong interdependence of different populations on each other. In this review we have identified the ecological roles played by each non-neoplastic population (macrophages, endothelial cells, fibroblasts) and other abiotic components (oxygen, extracellular matrix) directly involved with neoplastic development. A way to alter an ecosystem is to affect other species within the environment that are supporting the growth and survival of the species of interest, here the tumor cells; thus, some features of ecological systems could be exploited for cancer therapy. We propose a well-known antitumor therapy called photodynamic therapy (PDT) as a novel modulator of ecological interactions. We refer to this as “ecological photodynamic therapy.” The main goal of this new strategy is the improvement of therapeutic efficiency through the disruption of ecological networks with the aim of destroying the tumor ecosystem. It is therefore necessary to identify those interactions from which tumor cells get benefit and those by which it is impaired, and then design multitargeted combined photodynamic regimes in order to orchestrate non-neoplastic populations against their neoplastic counterpart. Thus, conceiving the tumor as an ecological system opens avenues for novel approaches on treatment strategies. 相似文献
180.