Electron transfer in multicentre redox proteins: from fundamentals to extracellular electron transfer.

Multicentre redox proteins participate in diverse metabolic processes, such as redox shuttling, multielectron catalysis, or long-distance electron conduction. The detail in which these processes can be analysed depends on the capacity of experimental methods to discriminate the multiple microstates that can be populated while the protein changes from the fully reduced to the fully oxidized state. The population of each state depends on the redox potential of the individual centres and on the magnitude of the interactions between the individual redox centres with their neighbours.

Environmental salinity modulates olfactory sensitivity in the euryhaline European seabass, Dicentrarchus labrax, acclimated to seawater and brackish water.

The olfactory epithelium of fish is - of necessity - in intimate contact with the surrounding water. In euryhaline fish, movement from seawater to freshwater (and vice versa) exposes the epithelium to massive changes in salinity and ionic concentrations. How does the olfactory system function in the face of such changes? The current study compared olfactory sensitivity in seawater- (35‰) and brackish water-adapted seabass (5‰) using extracellular multi-unit recording from the olfactory nerve.

Protein Interactions in TIE-1 Reveal the Molecular Basis for Resilient Photoferrotrophic Iron Oxidation.

is an alphaproteobacterium with impressive metabolic versatility, capable of oxidizing ferrous iron to fix carbon dioxide using light energy. Photoferrotrophic iron oxidation is one of the most ancient metabolisms, sustained by the operon coding for three proteins: PioB and PioA, which form an outer-membrane porin-cytochrome complex that oxidizes iron outside of the cell and transfers the electrons to the periplasmic high potential iron-sulfur protein (HIPIP) PioC, which delivers them to the light-harvesting reaction center (LH-RC). Previous studies have shown that PioA deletion is the most detrimental for iron oxidation, while, the deletion of PioC resulted in only a partial loss.

Validity of the Paediatric Canadian Triage Acuity Scale in a Tertiary Hospital: An Analysis of Severity Markers' Variability.

With the increasing influx of patients and frequent overcrowding, the adoption of a valid triage system, capable of distinguishing patients who need urgent care, from those who can wait safely is paramount. Hence, the aim of this study is to evaluate the validity of the Paediatric Canadian Triage and Acuity Scale (PaedCTAS) in a Portuguese tertiary hospital. Furthermore, we aim to study the performance and appropriateness of the different surrogate severity markers to validate triage.

On the Reuse of SLS Polyamide 12 Powder.

In the Selective Laser Sintering (SLS) technique, the great majority of the powder involved is not included in the final printed parts, being just used as a support material. However, the quality of this powder is negatively affected during the process since it is subjected to high temperatures (close to its melting temperature) during a long time, i.e.

Tribocorrosion-Resistant Ti40Nb-TiN Composites Having TiO-Based Nanotubular Surfaces.

A novel multifunctional material was developed by hard TiN particle reinforcement addition to a β-type Ti40Nb alloy, followed by surface functionalization, yielding the formation of a nanotubular layer. Corrosion and tribocorrosion behaviors were investigated in a phosphate-buffered saline solution at body temperature. The results revealed that the Ti40Nb-TiN composites presented similar and values together with relatively similar and .

High-grade L5-S1 spondylolisthesis with lumbosacral kyphosis: Long-term results of non-instrumented circumferential arthrodesis in children, adolescents.

Introduction: The choice of surgical technique for high-grade spondylolisthesis (HGS) associated with lumbosacral kyphosis remains controversial. Are non-instrumented techniques still relevant, what with the multiplicity and modernity of patient-specific instrumentation?

Hypothesis: Our hypothesis was that a non-instrumented circumferential arthrodesis performed after a period of gradual reduction of HGS, associated with lumbosacral kyphosis, provided satisfactory long-term functional and radiographic results in children and adolescents while minimizing the risk of complications.

Materials And Methods: Thirty-one L5-S1 HGS associated with a lumbosacral kyphosis operated by non-instrumented circumferential arthrodesis after a period of traction and suspension were included in our study.

Intestinal response to ocean acidification in the European sea bass (Dicentrarchus labrax).

The intestine of marine fishes contributes to the ocean carbon cycle producing carbonate aggregates as part of the osmoregulatory process. Therefore, this study aimed to evaluate physiological adjustments of European sea bass (Dicentrarchus labrax) intestine to a higher pCO environment likely in the near future (~1700 μatm). At the whole-body level, hypercapnia for 5 weeks resulted in fish having a significantly diminished specific growth rate, condition factor and hepatosomatic index.

Exposure effects of endotoxin-free titanium-based wear particles to human osteoblasts.

Titanium-based materials are widely employed by the biomedical industry in orthopedic and dental implants. However, when placed into the human body, these materials are highly susceptible to degradation processes, such as corrosion, wear, and tribocorrosion. As a consequence, metallic ions or particles (debris) may be released, and although several studies have been conducted in recent years to better understand the effects of their exposure to living cells, a consensual opinion has not yet been obtained.

Molecular and functional regionalization of bicarbonate secretion cascade in the intestine of the European sea bass (Dicentrarchus labrax).

In marine fish the intestinal HCO secretion is the key mechanism to enable luminal aggregate formation and water absorption. Using the sea bass (Dicentrarchus labrax), the present study aimed at establishing the functional and molecular organization of different sections of the intestine concerning bicarbonate secretion and Cl movements. The proximal intestinal regions presented similar HCO secretion rates, while differences were detected in the molecular expression of the transporters involved and on regional HCO concentrations.

Modulation of the reactivity of multiheme cytochromes by site-directed mutagenesis: moving towards the optimization of microbial electrochemical technologies.

Dissimilatory metal-reducing bacteria perform extracellular electron transfer, a metabolic trait that is at the core of a wide range of biotechnological applications. To better understand how these microorganisms transfer electrons from their metabolism to an extracellular electron acceptor, it is necessary to characterize in detail the key players in this process, the multiheme c-type cytochromes. Shewanella oneidensis MR-1 is a model organism for studying extracellular electron transfer, where the heme protein referred to as small tetraheme cytochrome is one of the most abundant multiheme cytochromes found in the periplasmic space of this bacterium.

Characterization of the periplasmic redox network that sustains the versatile anaerobic metabolism of Shewanella oneidensis MR-1.

The versatile anaerobic metabolism of the Gram-negative bacterium Shewanella oneidensis MR-1 (SOMR-1) relies on a multitude of redox proteins found in its periplasm. Most are multiheme cytochromes that carry electrons to terminal reductases of insoluble electron acceptors located at the cell surface, or bona fide terminal reductases of soluble electron acceptors. In this study, the interaction network of several multiheme cytochromes was explored by a combination of NMR spectroscopy, activity assays followed by UV-visible spectroscopy and comparison of surface electrostatic potentials.

The effect of thermal cycling on the shear bond strength of porcelain/Ti-6Al-4V interfaces.

The aim of the study was to evaluate the effect of thermal cycling on the shear bond strength of the porcelain/Ti-6Al-4V interfaces prepared by two different processing routes and metallic surface conditions. Polished and SiO2 particle abraded Ti-6Al-4V alloy and Triceram bonder porcelain were used to produce the interfaces. Porcelain-to-metal specimens were processed by conventional furnace firing and hot pressing.

Understanding bone safety zones during bone marrow aspiration from the iliac crest: the sector rule.

Purpose: Should the trocar suddenly lose contact with bone during bone marrow aspiration, it may result in visceral injury. The anatomy of the ilium and the structures adjacent to the iliac bone were studied to determine the danger of breach by a trocar introduced into the iliac crest.

Methods: The authors followed two series of patients, one series to do measurements of distance and angles of the structures at risk to the iliac bone and the other to evaluate the risk of a trocar being directed outside the iliac wing during bone marrow aspiration.

Anatomy of the ilium for bone marrow aspiration: map of sectors and implication for safe trocar placement.

Purpose: The bony anatomy of the human ilium has been well described from a qualitative perspective; however, there are little quantitative data to help the surgeon to perform bone marrow aspiration from the iliac crest in the thickest part of the ilium. The minimum thickness of the spongiousus bone in an iliac wing (transverse thickness between the two tables) is an important factor in ensuring the safe placement of a trocar between the two tables of the iliac wing. For example, with an 8-gauge (3.

Influence of the processing route of porcelain/Ti-6Al-4V interfaces on shear bond strength.

This study aims at evaluating the two-fold effect of initial surface conditions and dental porcelain-to-Ti-6Al-4V alloy joining processing route on the shear bond strength. Porcelain-to-Ti-6Al-4V samples were processed by conventional furnace firing (porcelain-fused-to-metal) and hot pressing. Prior to the processing, Ti-6Al-4V cylinders were prepared by three different surface treatments: polishing, alumina or silica blasting.

Exploration of the 'cytochromome' of Desulfuromonas acetoxidans, a marine bacterium capable of powering microbial fuel cells.

Recent progress in bacterial genomic analysis has revealed a vast number of genes that encode c-type cytochromes that contain multiple heme cofactors. This high number of multiheme cytochromes in several bacteria has been correlated with their great respiratory flexibility, and in what concerns biotechnological applications, has been correlated with electricity production in Microbial Fuel Cells. Desulfuromonas acetoxidans, a member of the Geobactereaceae family, is one of these organisms for which the genome was recently made available, coding for 47 putative multiheme cytochromes.

Arachnoid cyst in a patient with psychosis: Case report.

Background: The aetiology of a psychotic disturbance can be due to a functional or organic condition. Organic aetiologies are diverse and encompass organ failures, infections, nutritional deficiencies and space-occupying lesions. Arachnoid cysts are rare, benign space-occupying lesions formed by an arachnoid membrane containing cerebrospinal fluid (CSF).

Highly efficient production of laccase by the basidiomycete Pycnoporus cinnabarinus.

An efficient transformation and expression system was developed for the industrially relevant basidiomycete Pycnoporus cinnabarinus. This was used to transform a laccase-deficient monokaryotic strain with the homologous lac1 laccase gene placed under the regulation of its own promoter or that of the SC3 hydrophobin gene or the glyceraldehyde-3-phosphate dehydrogenase (GPD) gene of Schizophyllum commune. SC3-driven expression resulted in a maximal laccase activity of 107 nkat ml(-1) in liquid shaken cultures.

Two novel homologous proteins of Streptomyces coelicolor and Streptomyces lividans are involved in the formation of the rodlet layer and mediate attachment to a hydrophobic surface.

The filamentous bacteria Streptomyces coelicolor and Streptomyces lividans exhibit a complex life cycle. After a branched submerged mycelium has been established, aerial hyphae are formed that may septate to form chains of spores. The aerial structures possess several surface layers of unknown nature that make them hydrophobic, one of which is the rodlet layer.