Search results for "Biomaterial"

Evidence of atrazine mineralization in a soil from the Nile Delta: Isolation of Arthrobacter sp. TES6, an atrazine-degrading strain

2011

International audience; The s-triazine herbicide atrazine was rapidly mineralized (i.e., about 60% of C-14-ring-labelled atrazine released as (CO2)-C-14 within 21 days) by an agricultural soil from the Nile Delta (Egypt) that had been cropped with corn and periodically treated with this herbicide. Seven strains able to degrade atrazine were isolated by enrichment cultures of this soil. DNA fingerprint and phylogenetic studies based on 165 rRNA analysis showed that the seven strains were identical and belonged to the phylogeny of the genus Arthrobacter (99% similarity with Arthrobacter sp. AD38, EU710554). One strain, designated Arthrobacter sp. strain TES6, degraded atrazine and mineralized…

Biomineralizations: insights and prospects from crustaceans.

2011

19 pages; International audience; For growing, crustaceans have to molt cyclically because of the presence of a rigid exoskeleton. Most of the crustaceans harden their cuticle not only by sclerotization, like all the arthropods, but also by calcification. All the physiology of crustaceans, including the calcification process, is then linked to molting cycles. This means for these animals to find regularly a source of calcium ions quickly available just after ecdysis. The sources of calcium used are diverse, ranging from the environment where the animals live to endogenous calcium deposits cyclically elaborated by some of them. As a result, crustaceans are submitted to an important and energ…

Strengthening of Masonry Columns with BFRCM or with Steel Wires: An Experimental Study

2016

Nowadays, innovative materials are more frequently adopted for strengthening historical constructions and masonry structures. The target of these techniques is to improve the structural efficiency with retrofitting methods while having a reduced aesthetical impact. In particular, the use of basalt fiber together with a cementitious matrix emerges as a new technique. This kind of fiber is obtained by basalt rock without other components, and consequently it could be considered a natural material, compatible with masonry. Another innovative technique for strengthening masonry columns consists of applying steel wires in the correspondence of mortar joints. Both techniques have been recently pr…

An impaired alveolar-capillary barrier in vitro : effect of proinflammatory cytokines and consequences on nanocarrier interaction.

2009

The alveolar region of the lung is an important target for drug and gene delivery approaches. Treatment with drugs is often necessary under pathophysiological conditions, in which there is acute inflammation of the target organ. Therefore, in vitro models of the alveolar-capillary barrier, which mimic inflammatory conditions in the alveolar region, would be useful to analyse and predict effects of novel drugs on healthy or inflamed tissues. The epithelial cell line H441 was cultivated with primary isolated human pulmonary microvascular endothelial cells (HPMECs) or the endothelial cell line ISO-HAS-1 on opposite sides of a permeable filter support under physiological and inflammatory condi…

A simple strategy based on photobiotin irradiation for the photoelectrochemical immobilization of proteins on electrode surfaces

2006

Abstract A photoactivable organic polymer was prepared first by electrogeneration of a conductive biotinylated polypyrrole film in acetonitrile electrolyte. The successive anchoring of avidin and photobiotin led to a multilayer configuration. The latter was illuminated with light (wavelength 370–400 nm) in the presence of proteins adsorbed onto its surface. The irradiation allowed the covalent linking of the proteins to the modified electrode. As a result of the photochemical reaction, a monolayer of enzyme (glucose oxidase, GOX or alkaline phosphatase, AP) was covalently bound to the photobiotin-modified surface with retention of their catalytic activities. The surfacic activities were 34 …

Microstructures in shells of the freshwater gastropod Viviparus viviparus: a potential sensor for temperature change?

2013

Abstract Mollusk shells contain a plethora of information on past climate variability. However, only a limited toolkit is currently available to reconstruct such data from the shells. The environmental data of some proxies (e.g. Sr/Ca ratios) is obscured by physiological effects, whereas other proxies, such as δ 18 O, simultaneously provide information on two or more different environmental variables. The present study investigates whether microstructures of the freshwater gastropod Viviparus viviparus provide an alternative means to reconstruct past water temperature. Cold and highly variable temperature regimes resulted in the precipitation of highly unordered first-order lamellae of simp…

Surface Modification of Porous Polyethylene Implants with an Albumin-Based Nanocarrier-Release System

2021

Background: Porous polyethylene (PPE) implants are used for the reconstruction of tissue defects but have a risk of rejection in case of insufficient ingrowth into the host tissue. Various growth factors can promote implant ingrowth, yet a long-term gradient is a prerequisite for the mediation of these effects. As modification of the implant surface with nanocarriers may facilitate a long-term gradient by sustained factor release, implants modified with crosslinked albumin nanocarriers were evaluated in vivo. Methods: Nanocarriers from murine serum albumin (MSA) were prepared by an inverse miniemulsion technique encapsulating either a low- or high-molar mass fluorescent cargo. PPE implants …

Boron Ions: Simultaneous Boron Ion‐Channel/Growth Factor Receptor Activation for Enhanced Vascularization (Adv. Biosys. 1/2019)

2019

Optical sensing of cyanide using hybrid biomolecular films

2006

The selective sensing of cyanide anions in water has been studied using a hybrid biomaterial composed of a mesoporous TiO2 film of crystalline nanoparticles and the protein hemoglobin. The mesoporous structure of the film prevents protein unfolding and also stabilizes the oxidized form of the prosthetic groups. Low-levels of cyanide anions (<0.2 ppm (0.2 mgr/L)) can be detected by monitoring the changes in the optical properties of the hybrid biomolecular films upon cyanide binding to the heme groups.

Spoilage of oat bran by sporogenic microorganisms revived from soil buried 4000 years ago in Iranian archaeological site

2015

Abstract The Bronze Age archaeological site of Shahr-i Sokhta (30° 39′ N; 61° 24’ E), located today in southeastern Iran, Sistan region, is a special archaeological deposit in which the exceptional preservation of human, plant and animal remains, due to the dry climate of the region, can provide detailed information on one of the first complex proto-urban societies. In recent years, there has been growing interest in changes in local climate and environment as major reasons why the settlement was abandoned about 4000 years ago. Food shortage has been regarded as a direct effect of these changes. No attention has been paid to the potential health hazards associated with ancient urban/domesti…