33 research outputs found
Efficient synthesis of small-sized phosphonated dendrons: potential organic coatings of iron oxide nanoparticles:
We report herein the synthesis of biocompatible small-sized phosphonated monomers and dendrons used as functional coatings of metal oxide nanoparticles, more specifically superparamagnetic iron oxides (SPIOs) for magnetic resonance imaging (MRI) and therapy through hyperthermia. The molecules were engineered to modulate their size, their hydrophilic and/or biocompatible character (poly(amido) amine versus oligoethyleneglycol), the number of anchoring phosphonate groups (monophosphonate versus phosphonic tweezers) and the number of peripheral functional groups for further grafting of dyes or specific vectors. Such a library of hydrophilic phosphonic acids opens new possibilities for the investigation of dendronized nanohybrids as theranostics
Aplicação de um modelo de avaliação de alinhamento estratégico em construtoras cearenses
Reconstruction and simulation of neocortical microcircuitry
We present a first-draft digital reconstruction of the microcircuitry of somatosensory cortex of juvenile rat. The reconstruction uses cellular and synaptic organizing principles to algorithmically reconstruct detailed anatomy and physiology from sparse experimental data. An objective anatomical method defines a neocortical volume of 0.29 ± 0.01 mm3 containing âŒ31,000 neurons, and patch-clamp studies identify 55 layer-specific morphological and 207 morpho-electrical neuron subtypes. When digitally reconstructed neurons are positioned in the volume and synapse formation is restricted to biological bouton densities and numbers of synapses per connection, their overlapping arbors form âŒ8 million connections with âŒ37 million synapses. Simulations reproduce an array of in vitro and in vivo experiments without parameter tuning. Additionally, we find a spectrum of network states with a sharp transition from synchronous to asynchronous activity, modulated by physiological mechanisms. The spectrum of network states, dynamically reconfigured around this transition, supports diverse information processing strategies
Tissue adhesives for meniscus tear repair: an overview of current advances and prospects for future clinical solutions
Fabrication of Composite Hydrogels Based on Soy Protein Isolate and their Controlled Globular Protein Delivery
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The efficacy of a lysine-based dendritic hydrogel does not differ from those of commercially available tissue sealants and adhesives: an ex vivo study
Background: Hemostatic agents, tissue adhesives and sealants may contribute to a reduction in hemorrhage-associated morbidity and mortality. Towards this end, we have recently developed a lysine-based dendritic hydrogel (PEG-LysNH2) that can potentially be used in the management of severe trauma and/or intraoperative bleeding. As a first step in demonstrating the potential utility of this approach, our objective was to ascertain the ability of the PEG-LysNH2 to adhere to and seal injured tissues, as well as to maintain the seal under physiological conditions. Methods: The efficacy of the PEG-LysNH2 in sealing injured tissues was evaluated using an ex-vivo pressure testing system. A 2.5 mm incision was made on intact ex-vivo tissues and then sealed with the PEG-LysNH2. Application of the PEG-LysNH2 was followed by 1) step-wise pressure increase to a maximum of 250 mmHg and 2) fluctuating pressures, between 100â180 mmHg with a rate of 3 Hz, over a 24-hour period. The performance of the PEG-LysNH2 was compared to those of commercially available sealants and adhesives. Results: During gradual pressure increase, mean pressures at 30 seconds (P30) ranged between 206.36 - 220.17 mmHg for the sealants, and they were greater than control and suture groups (p < 0.01 and p = 0.013, respectively). Additionally, all products held under fluctuating pressures: mean pressures ranged between 135.20 - 160.09 mmHg, and there were no differences observed between groups (p = 0.96). Conclusions: The efficacy of the PEG-LysNH2 was significantly superior to conventional injury repair methods (sutures) and did not differ from those of commercially available products when sealing small incisions
Curbing Foreign Distributor Opportunism: An Examination of Trust, Contracts, and the Legal Environment in International Channel Relationships
The efficacy of a lysine-based dendritic hydrogel does not differ from those of commercially available tissue sealants and adhesives: an ex vivo study
The chemistry and engineering of polymeric hydrogel adhesives for wound closure: a tutorial
Development and applications of a DNA labeling method with magnetic nanoparticles to study the role of horizontal gene transfer events between bacteria in soil pollutant bioremediation processes
International audienceHorizontal gene transfers are critical mechanisms of bacterial evolution and adaptation that are involved to a significant level in the degradation of toxic molecules such as xenobiotic pesticides. However, understanding how these mechanisms are regulated in situ and how they could be used by man to increase the degradation potential of soil microbes is compromised by conceptual and technical limitations. This includes the physical and chemical complexity and heterogeneity in such environments leading to an extreme bacterial taxonomical diversity and a strong redundancy of genes and functions. In addition, more than 99 % of soil bacteria fail to develop colonies in vitro, and even new DNA-based investigation methods (metagenomics) are not specific and sensitive enough to consider lysis recalcitrant bacteria and those belonging to the rare biosphere. The objective of the ANR funded project âEmergentâ was to develop a new culture independent approach to monitor gene transfer among soil bacteria by labeling plasmid DNA with magnetic nanoparticles in order to specifically capture and isolate recombinant cells using magnetic microfluidic devices. We showed the feasibility of the approach by using electrotransformation to transform a suspension of Escherichia coli cells with biotin-functionalized plasmid DNA molecules linked to streptavidin-coated superparamagnetic nanoparticles. Our results have demonstrated that magnetically labeled cells could be specifically retained on micromagnets integrated in a microfluidic channel and that an efficient selective separation can be achieved with the microfluidic device. Altogether, the project offers a promising alternative to traditional culture-based approaches for deciphering the extent of horizontal gene transfer events mediated by electro or natural genetic transformation mechanisms in complex environments such as soil