Magnetic Bone Tissue Engineering: Reviewing the Effects of Magnetic Stimulation on Bone Regeneration and Angiogenesis.

Bone tissue engineering emerged as a solution to treat critical bone defects, aiding in tissue regeneration and implant integration. Mainly, this field is based on the development of scaffolds and coatings that stimulate cells to proliferate and differentiate in order to create a biologically active bone substitute. In terms of materials, several polymeric and ceramic scaffolds have been developed and their properties tailored with the objective to promote bone regeneration.

and Genes in the Blue Crab, : A Temporal Evaluation and Melatonin Effects.

Environmental cues synchronize endogenous rhythms of many physiological processes such as hormone synthesis and secretion. Little is known about the diurnal pattern of hormones and gene expression of the molt cycle. We aimed to investigate in the eyestalk and hepatopancreas of premolt and intermolt the following parameters: 1) the diurnal expression of the ecdysteroid receptor isoforms, and the molt inhibiting hormone 2) the diurnal hemolymph ecdysteroid and melatonin levels; and 3) melatonin effects on the transcripts of the above-mentioned genes in intermolt .

Seasonal effect on biomarker responses in sentinel species: innovation in mangrove conservation status assessment.

We evaluated the environmental quality in mangrove areas of the Western Atlantic with different levels and history of contamination, considering biomarkers for the crab Ucides cordatus. For this purpose, specimens were collected in two climatic seasons (rainy and dry seasons) and assays of genotoxicity (MN, micronucleus), cytotoxicity (NRRT, neutral red retention time) and biochemical (MT, metallothionein; and LPO, lipoperoxidation) were conducted. In the most impacted mangroves, there was an increase in the mean of micronucleus (frequency of MN/1000), which was associated with a shorter retention time (minutes of NRRT).

Experimental effects of cadmium on physiological response of Callinectes danae (Crustacea, Portunidae) from environments with different levels of Cd contamination.

Cadmium (Cd) can adversely affect aquatic life, altering reproductive and molting processes in crustaceans. The objective of this study was to evaluate the influence of Cd on reproduction and molting in the crab Callinectes danae. Adult females were obtained from environments with different levels of pollution: low (LC), medium (MC), and high contaminated (HC) areas.

Hyperscroll dynamics: Vortices in four-dimensional networks.

We investigate a network of excitable nodes diffusively coupled to their neighbors along four orthogonal directions. This regular network effectively forms a four-dimensional reaction-diffusion system and has rotating wave solutions. We analyze some of the general features of these hyperscroll waves, which rotate around surfaces such as planes, spheres, or tori.

Asymmetric synchronization in lattices of pinned spiral waves.

Networks of coupled oscillators show a wealth of fascinating dynamics and are capable of storing and processing information. In biological and social networks, the coupling is often asymmetric. We use the chirality of rotating spiral waves to introduce this asymmetry in an excitable reaction-diffusion model.

Magnetic Resonance Imaging in Situ Visualization of an Electrochemical Reaction under Forced Hydrodynamic Conditions.

Magnetic resonance imaging (MRI) has proven to be a powerful tool for the characterization and investigation of in situ chemical reactions. This is more relevant when dealing with complex systems, where the spatial distribution of the species, partition equilibrium, flow patterns, among other factors have a determining effect over mass transport and therefore over the reaction rate. The advantage of MRI is that it provides spatial information in a noninvasive way and does not require any molecular sensor or sample extraction.

Magnetite nanoparticles coated with oleic acid: accumulation in hepatopancreatic cells of the mangrove crab Ucides cordatus.

The field of nanotechnology had enormous developments, resulting in new methods for the controlled synthesis of a wide variety of nanoscale materials with unique properties. Efficient methods such as thermal decomposition for efficient size control have been developed in recent years for the synthesis of oleic acid (OA)-coated magnetite (FeO) nanoparticles (MNP-OA). These nanostructures can be a source of pollution when emitted in the aquatic environment and could be accumulated by vulnerable marine species such as crustaceans.

Evaluation of iron loading in four types of hepatopancreatic cells of the mangrove crab Ucides cordatus using ferrocene derivatives and iron supplements.

The mangrove crab Ucides cordatus is a bioindicator of aquatic contamination. In this work, the iron availability and redox activity of saccharide-coated mineral iron supplements (for both human and veterinary use) and ferrocene derivatives in Saline Ucides Buffer (SUB) medium were assessed. The transport of these metallodrugs by four different hepatopancreatic cell types (embryonic (E), resorptive (R), fibrillar (F), and blister (B)) of U.

Flow-Pattern Characterization of Biphasic Electrochemical Cells by Magnetic Resonance Imaging under Forced Hydrodynamic Conditions.

The fluid dynamics of a liquid|liquid system inside a four-electrode electrochemical cell were studied by velocimetry magnetic resonance imaging (MRI) and flow propagator measurements. To characterize this system fully, three different cell configurations operating at two rotational frequencies were analyzed. Quantitative information about the stability of the liquid|liquid interface and the dynamics of the organic phase were determined.

Characterization of cadmium transport in hepatopancreatic cells of a mangrove crab Ucides cordatus: The role of calcium.

Cadmium is a toxic metal, present in batteries and discarded in estuaries and mangrove habitats. Apart from that, it is a non-essential metal that causes toxic effects in many organisms. Cadmium accumulates in gills and hepatopancreas of crustaceans and its route into the cell is unknown.

Physiological differences in the crab Ucides cordatus from two populations inhabiting mangroves with different levels of cadmium contamination.

Crustaceans found in metal-contaminated regions are able to survive, and the authors investigated the physiological mechanisms involved by comparing populations from contaminated and noncontaminated areas. The objective of the present study was to measure the cellular transport of a nonessential metal (cadmium [Cd]) in gills and hepatopancreas of Ucides cordatus, together with cell membrane fluidity, metallothionein levels, and lipid peroxidation. The 2 populations compared were from a polluted and a nonpolluted mangrove area of São Paulo State, Brazil.

Mechanochemical stability of sub-nm ZnO chains.

Formation of monoatomic chains by axial stretching of zinc oxide nanowires is investigated using molecular dynamics and supported by density functional calculations. Special focus is made on the mechanical properties of these structures. Using a state-of-the-art force field it was found that O2 species are commonly formed within the chain.

Iron metallodrugs: stability, redox activity and toxicity against Artemia salina.

Iron metallodrugs comprise mineral supplements, anti-hypertensive agents and, more recently, magnetic nanomaterials, with both therapeutic and diagnostic roles. As biologically-active metal compounds, concern has been raised regarding the impact of these compounds when emitted to the environment and associated ecotoxicological effects for the fauna. In this work we assessed the relative stability of several iron compounds (supplements based on glucoheptonate, dextran or glycinate, as well as 3,5,5-trimethylhexanoyl (TMH) derivatives of ferrocene) against high affinity models of biological binding, calcein and aprotransferrin, via a fluorimetric method.

Characterization of angiotensin I-converting enzyme from anterior gills of the mangrove crab Ucides cordatus.

Angiotensin I-converting enzyme (ACE) is a well-known metallopeptidase that is found in vertebrates, invertebrates and bacteria. We isolated from the anterior gill of the crab Ucides cordatus an isoform of ACE, here named crab-ACE, which presented catalytic properties closely resembling to those of mammalian ACE. The enzyme was purified on Sepharose-lisinopril affinity chromatography to apparent homogeneity and a band of about 72 kDa could be visualized after silver staining and Western blotting.

Characterization of cadmium plasma membrane transport in gills of a mangrove crab Ucides cordatus.

Membrane pathway for intracellular cadmium (Cd(2+)) accumulation is not fully elucidated in many organisms and has not been studied in crab gill cells. To characterize membrane Cd(2+) transport of anterior and posterior gill cells of Ucides cordatus, a hypo-hyper-regulating crab, a change in intracellular Cd(2+) concentration under various experimental conditions was examined by using FluoZin, a fluorescent probe. The membrane Cd(2+) transport was estimated by the augmentation of FluoZin fluorescence induced by extracellular application of CdCl2 and different inhibitors.

Characterization of copper transport in gill cells of a mangrove crab Ucides cordatus.

The branchial epithelium of crustaceans is exposed to the environment and is the first site affected by metal pollution. The aim of this work was to characterize copper (Cu) transport using a fluorescent dye, Phen Green, in gill cells of a hypo-hyper-regulator mangrove crab Ucides cordatus. The results showed that added extracellular CuCl2 (0, 0.

Calcium transport in gill cells of Ucides cordatus, a mangrove crab living in variable salinity environments.

Crustaceans show discontinuous growth and have been used as a model system for studying cellular mechanisms of calcium transport, which is the main mineral found in their exoskeleton. Ucides cordatus, a mangrove crab, is naturally exposed to fluctuations in calcium and salinity. To study calcium transport in this species during isosmotic conditions, dissociated gill cells were marked with fluo-3 and intracellular Ca(2+) change was followed by adding extracellular Ca(2+) as CaCl2 (0, 0.

Accumulation of six metals in the mangrove crab Ucides cordatus (Crustacea: Ucididae) and its food source, the red mangrove Rhizophora mangle (Angiosperma: Rhizophoraceae).

The crab Ucides cordatus and the red mangrove Rhizophora mangle are endemic mangrove species and potential bio-accumulators of metals. This study quantified the accumulation of six metals (Cd, Cr, Cu, Hg, Mn and Pb) in different organs (claw muscle, hepatopancreas and gills) of U. cordatus, as well as in different maturation stages of the leaves (buds, green mature, and pre-abscission senescent) of R.

3H-L-leucine transport by the promiscuous crustacean dipeptide-like cotransporter.

The crustacean intestine and hepatopancreas display a variety of solute transport mechanisms for transmembrane transfer of dietary contents from lumen to epithelial cytosol. An in vitro intestinal perfusion apparatus was used to characterize mucosal to serosoal (MS) and serosal to mucosal (SM) Zn(2+) -dependent (3)H-L-leucine transport by the intestine of the American lobster, Homarus americanus. Transmural 20 µM MS (3)H-L-leucine fluxes across lobster intestine were a hyperbolic function of luminal zinc concentration (1-50 µM) following Michaelis-Menten kinetics (K(m) = 2.

Separation and viability of gill and hepatopancreatic cells of a mangrove crab Ucides cordatus.

The gills contain essential cells for respiration and osmoregulation, whereas the hepatopancreas is the site of digestion, absorption, and nutrients storage. The aim of this work was to separate and characterize gill and hepatopancreatic cells of the mangrove crab, Ucides cordatus. For gills, the methodology consisted of an enzymatic cellular dissociation using Trypsin at 0.

ATP pulse and calcium homeostasis in cells from hepatopancreas of Dilocarcinus pagei, a freshwater crab.

Calcium (Ca) is critical for crustaceans due to their molting cycle and its presence in the carapace as calcium carbonate, apart from the usual functions of Ca, such as cell signalling. Ca transport in Dilocarcinus pagei, a freshwater crab, was studied in isolated cells from hepatopancreas to further characterize Ca transport mechanisms in these crabs. Cells were isolated and loaded with Fluo-3, a calcium fluorescent dye.

Calcium transport and homeostasis in gill cells of a freshwater crab Dilocarcinus pagei.

Crustaceans present a very interesting model system to study the process of calcification and calcium (Ca(2+)) transport because of molting-related events and the deposition of CaCO(3) in the new exoskeleton. Dilocarcinus pagei, a freshwater crab endemic to Brazil, was studied to understand Ca(2+) transport in whole gill cells using a fluorescent probe. Cells were dissociated, all of the gill cell types were loaded with fluo-3 and intracellular Ca(2+) change was monitored by adding Ca as CaCl(2) (0, 0.

65Zn2+ transport by isolated gill epithelial cells of the American lobster, Homarus americanus.

Gills are the first site of impact by metal ions in contaminated waters. Work on whole gill cells and metal uptake has not been reported before in crustaceans. In this study, gill filaments of the American lobster, Homarus americanus, were dissociated in physiological saline and separated into several cell types on a 30, 40, 50, and 80% sucrose gradient.