382 research outputs found

    Synthesis of Silver Nanoparticles Using Curcumin-Cyclodextrins Loaded into Bacterial Cellulose-Based Hydrogels for Wound Dressing Applications.

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    Chronic wounds are often recalcitrant to treatment because of high microbial bioburden and the problem of microbial resistance. Silver is a broad-spectrum natural antimicrobial agent with wide applications extending to proprietary wound dressings. Recently, silver nanoparticles have attracted attention in wound management. In the current study, the green synthesis of nanoparticles was accomplished using a natural reducing agent, curcumin, which is a natural polyphenolic compound that is well-known as a wound-healing agent. The hydrophobicity of curcumin was overcome by its microencapsulation in cyclodextrins. This study demonstrates the production, characterization of silver nanoparticles using aqueous curcumin:hydroxypropyl-β-cyclodextrin complex and loading them into bacterial cellulose hydrogel with moist wound-healing properties. These silver nanoparticle-loaded bacterial cellulose hydrogels were characterized for wound-management applications. In addition to high cytocompatibility, these novel dressings exhibited antimicrobial activity against three common wound-infecting pathogenic microbes , , and

    Mechanisms generating long-range correlation in nucleotide composition of the Borrelia burgdorferi genome

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    Abstract We have analysed protein coding and intergenic sequences in the Borrelia burgdorferi (the Lyme disease bacterium) genome using di erent kinds of DNA walks. Genes occupying the leading strand of DNA have signiÿcantly di erent nucleotide composition from genes occupying the lagging strand. Nucleotide compositional bias of the two DNA strands re ects the aminoacid composition of proteins. 96% of genes coding for ribosomal proteins lie on the leading DNA strand, which suggests that the positions of these as well as other genes are non-random. In the B. burgdorferi genome, the asymmetry in intergenic DNA sequences is lower than the asymmetry in the third positions in codons. All these characters of the B. burgdorferi genome suggest that both replication-associated mutational pressure and recombination mechanisms have established the speciÿc structure of the genome and now any recombination leading to inversion of a gene in respect to the direction of replication is forbidden. This property of the genome allows us to assume that it is in a steady state, which enables us to ÿx some parameters for simulations of DNA evolution. c 1999 Elsevier Science B.V. All rights reserved. PACS: 87.14.G; 05.10-a Keywords: Long-range correlation; Replication; Transcription * Corresponding author. Fax: +48-71-3252151. E-mail addresses: [email protected] (S. Cebrat), [email protected] (M.R. Dudek) 0378-4371/99/$ -see front matter c 1999 Elsevier Science B.V. All rights reserved. PII: S 0 3 7 8 -4 3 7 1 ( 9 9 ) 0 0 3 4 5 -3 104 P. Mackiewicz et al. / Physica A 273 (1999) 103-11

    Anti-Inflammatory Effect of Dexamethasone Controlled Released From Anterior Suprachoroidal Polyurethane Implants on Endotoxin-Induced Uveitis in Rats.

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    Targeted drug delivery to the ocular tissues remains a challenge. Biodegradable intraocular implants allow prolonged controlled release of drugs directly into the eye. In this study, we evaluated an anterior suprachoroidal polyurethane implant containing dexamethasone polyurethane dispersions (DX-PUD) as a drug delivery system in the rat model of endotoxin-induced uveitis (EIU). In vitro drug release was studied using PUD implants containing 8%, 20%, and 30% (wt/wt) DX. Cytotoxicity of the degradation products of DX-PUD was assessed on human ARPE-19 cells using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) test. Short-term ocular biocompatibility of suprachoroidal DX-PUD implants was evaluated in normal rat eyes. Endotoxin-induced uveitis was then induced in rat eyes preimplanted with DX-PUD. Clinical examination was performed at 24 hours; eyes were used to assess inflammatory cell infiltration and macrophage/microglial activation. Cytokine and chemokine expression in the iris/ciliary body and in the retina was investigated using quantitative PCR. Feasibility of anterior suprachoroidal PUD implantation was also tested using postmortem human eyes. A burst release was followed by a sustained controlled release of DX from PUD implants. By-products of the DX-PUD were not toxic to human ARPE-19 cells or to rat ocular tissues. Dexamethasone-PUD implants prevented EIU in rat eyes, reducing inflammatory cell infiltration and inhibiting macrophage/microglial activation. Dexamethasone-PUD downregulated proinflammatory cytokines/chemokines (IL-1β, IL-6, cytokine-induced neutrophil chemoattractant [CINC]) and inducible nitric oxide synthase (iNOS) and upregulated IL-10 anti-inflammatory cytokine. Polyurethane dispersion was successfully implanted into postmortem human eyes. Dexamethasone-PUD implanted in the anterior suprachoroidal space may be of interest in the treatment of intraocular inflammation

    Solvent contribution to the stability of a physical gel characterized by quasi-elastic neutron scattering

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    The dynamics of a physical gel, namely the Low Molecular Mass Organic Gelator {\textit Methyl-4,6-O-benzylidene-α\alpha -D-mannopyranoside (α\alpha-manno)} in water and toluene are probed by neutron scattering. Using high gelator concentrations, we were able to determine, on a timescale from a few ps to 1 ns, the number of solvent molecules that are immobilised by the rigid network formed by the gelators. We found that only few toluene molecules per gelator participate to the network which is formed by hydrogen bonding between the gelators' sugar moieties. In water, however, the interactions leading to the gel formations are weaker, involving dipolar, hydrophobic or ππ\pi-\pi interactions and hydrogen bonds are formed between the gelators and the surrounding water. Therefore, around 10 to 14 water molecules per gelator are immobilised by the presence of the network. This study shows that neutron scattering can give valuable information about the behaviour of solvent confined in a molecular gel.Comment: Langmuir (2015

    Protocols for the field testing

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    The COMMON SENSE project has been designed and planned in order to meet the general and specific scientific and technical objectives mentioned in its Description of Work (page 77). In an overall strategy of the work plan, work packages (11) can be grouped into 3 key phases: (1) RD basis for cost-effective sensor development, (2) Sensor development, sensor web platform and integration, and (3) Field testing. In the first two phases WP1 and WP2 partners have provided a general understanding and integrated basis for a cost effective sensors development. Within the following WPs 4 to 8 the new sensors are created and integrated into different identified platforms. During the third phase 3, characterized by WP9, partners will deploy precompetitive prototypes at chosen platforms (e.g. research vessels, oil platforms, buoys and submerged moorings, ocean racing yachts, drifting buoys). Starting from August 2015 (month 22; task 9.2), these platforms will allow the partnership to test the adaptability and performance of the in-situ sensors and verify if the transmission of data is properly made, correcting deviations. In task 9.1 all stakeholders identified in WP2, and other relevant agents, have been contacted in order to close a coordinated agenda for the field testing phase for each of the platforms. Field testing procedures (WP2) and deployment specificities, defined during sensor development in WPs 4 to 8, are closely studied by all stakeholders involved in field testing activities in order for everyone to know their role, how to proceed and to provide themselves with the necessary material and equipment (e.g. transport of instruments). All this information will provide the basis for designing and coordinating field testing activities. Type and characteristics of the system (vessel or mooring, surface or deep, open sea or coastal area, duration, etc.), used for the field testing activities, are planned comprising the indicators included in the above-mentioned descriptors, taking into account that they must of interest for eutrophication, concentration of contaminants, marine litter and underwater noise. In order to obtain the necessary information, two tables were realized starting from the information acquired for D2.2 delivered in June 2014. One table was created for sensor developers and one for those partners that will test the sensors at sea. The six developers in COMMON SENSE have provided information on the seven sensors: CEFAS and IOPAN for underwater noise; IDRONAUT and LEITAT for microplastics; CSIC for an innovative piro and piezo resistive polymeric temperature and pressure and for heavy metal; DCU for the eutrophication sensor. This information is anyway incomplete because in most cases the novel sensors are still far to be ready and will be developed over the course of COMMON SENSE. So the sensors cannot be clearly designed yet and, consequently, technical characteristics cannot still be perfectly defined. This produces some lag in the acquired information and, consequently, in the planning of their testing on specific platforms that will be solved in the near future. In the table for Testers, partners have provided information on fifteen available platforms. Specific answers have been given on number and type of sensors on each platforms, their availability and technical characteristics, compatibility issues and, very important when new sensors are tested, comparative measurements to be implemented to verify them. Finally IOPAN has described two more platforms, a motorboat not listed in the DoW, but already introduced in D2.2, and their oceanographic buoy in the Gdansk Bay that was previously unavailable. The same availability now is present for the OBSEA Underwater observatory from CSIC, while their Aqualog undulating mooring is still not ready for use. In the following months, new information on sensors and platforms will be provided and the planning of testing activities will improve. Further updates of this report will be therefore necessary in order to individuate the most suitable platforms to test each kind of sensor. Objectives and rationale The objective of deliverable 9.1 is the definition of field testing procedures (WP2), the study of deployment specificities during sensor development work packages (from WP4 to WP8) and the preparation of protocols. This with the participation of all stakeholders involved in field testing activities in order for everyone to know their role, how to proceed and to provide themselves with the necessary material and equipment

    Field testing, validation and optimization report

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    The COMMON SENSE project has been designed and planned in order to meet the general and specific scientific and technical objectives mentioned in its Description of Work (page 77). As the overall strategy, the 11 work packages (WPs) of the work plan were grouped into 3 key phases: (1) RD basis for cost-effective sensor development , (2) Sensor development, sensor web platform and integration, and (3) Field testing. In the first two phases, partners involved in WP1 and WP2 have provided a general understanding and integrated basis for a cost effective sensors development. Within the following WPs 4 to 8 the new sensors were created and integrated into different identified platforms. During the third phase of field testing (WP9), partners have deployed precompetitive prototypes at chosen platforms (e.g. research vessels, oil platforms, buoys and submerged moorings, ocean racing yachts, drifting buoys). Starting from August 2015 (month 22; task 9.2), these platforms have allowed the partnership to test the adaptability and performance of the in-situ sensors and verify if the transmission of data is properly made, correcting deviations. In task 9.1 all stakeholders identified in WP2 have been contacted in order to agree upon a coordinated agenda for the field testing phase for each of the platforms. Field testing procedures (WP2) and deployment specificities, defined during sensor development in WPs 4 to 8, have been closely studied by all stakeholders involved in field testing activities in order for everyone to know their role, how to proceed and to provide themselves with the necessary material and equipment (e.g. transport of instruments). All this information have provided the basis for designing and coordinating field testing activities. Subsequently, the available new sensors have been tested since August 2015 till mid-October of the current year (2016) as part of task 9.2, following the indications defined in D9.1, such as the intercomparison of the new sensors with commercial ones, when possible. The availability of new sensors was quite different in time starting with the first tests in September and October 2015 on noise, nutrient and heavy metals sensors and closing with pCO2 in late September 2016. Sensors are technically fully described in the deliverables of WPs 3 to 8 and are here just mentioned where necessary. For further details, please consider those reports. Objectives and rationale The protocols prepared in D9.1 have been verified during the field testing activities of the innovative sensors on platforms. These can be summarized into 3 categories: (1) Research vessels (regular cruises); (2) Fixed platforms; (3) Ocean racing yachts. An exhaustive analysis of the different data obtained during field testing activities has been carried on in order to set possible optimization actions for prototypes design and performances. The data from each platform have been analyzed to verify limits and optimal installations or possible improvements. Finally a set of possible optimization actions has been defined. Data and observations collected during the course of field testing have been used to iteratively optimize the design and performance of the precompetitive prototypes
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