Search results for "Oxide"

Automated pre-column derivatization of amines in biological samples with dansyl chloride and with or without post-column chemiluminescence formation …

1999

On-line automation of two different liquid chromatographic procedures, a pre-column derivatization system and a pre- and post-column system, in order to generate chemiluminescence is reported. Dansyl chloride (Dns-Cl) was used as a pre-column reagent to form fluorophores and bis(2,4,6-trichlorophenyl) oxalate (TCPO) and hydrogen peroxide (H2O2) as a post-column reagent to generate chemiluminescence. This procedure is based on the employment of a primary column packed with C18 material inserted in a multi-dimensional assembly for sample clean-up and derivatization with Dns-Cl. The dansyl derivatives formed are transferred and separated in a LiChrospher 100 RP18 analytical column (125 x 4 mm …

A solid device based on doped hybrid composites for controlling the dosage of the biocide N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine in industria…

2015

A colorimetric composite device is proposed to determine the widely used biocide N-(3-aminopropyl)-N-dodecyl-1,3-propanediamine (ADP).This sensing device is based on a film of 1,2-Naphthoquinone-4-sulfonate (NQS) embedded into polydimethylsiloxane-tetraethylortosilicate-SiO2 nanoparticles composite (PDMS-TEOS-SiO2NPs). Semiquantitative analysis can be performed by visual inspection. Digitalized image or diffuse reflectance (DR) measurements can be carried out for quantitative analysis. Satisfactory detection limit (0.018%, w/v) and relative standard deviations <12% were achieved. The proposed device has been applied for the determination of ADP in detergent industrial formulations with reco…

Influence of a bioceramic root end material and mineral trioxide aggregates on fibroblasts and osteoblasts

2012

The biocompatibility of materials used in endodontic treatment is of high importance, because they can come in contact with periradicular tissues and there is a risk of possible systemic toxicity. The aim of the present study was to investigate the in vitro reaction to a bioceramic based root end material in comparison to mineral trioxide aggregates (MTA) as the established gold standard.The root end materials grey MTA Angelus (GMTA), white MTA Angelus (WMTA), ProRoot MTA, and EndoSequence Root Repair Material (ERRM) were incubated with human periodontal ligament fibroblasts and osteoblasts (10(4)cells/ml) for up to 96h. Cell proliferation (RFU) was determined by means of the Alamar Blue as…

Silver Oxide Mediated Monotosylation of Poly(ethylene glycol) (PEG): Heterobifunctional PEG via Polymer Desymmetrization

2017

Heterobifunctional poly(ethylene glycol)s (PEGs) are key structures for bioconjugation in the context of the “PEGylation” strategy to enhance blood circulation times of, for example, peptide drugs or “stealth” liposomes. The formation of heterobifunctional PEGs from symmetric PEG diols is challenging because of limited yields of the targeted monofunctional product and difficulties associated with separation steps. On the basis of a detailed comparison of reaction conditions, we have investigated a “polymer desymmetrization” strategy to maximize the yields of monofunctional PEG tosylate. The tosylation reaction in the presence of the heterogeneous catalyst silver oxide and potassium iodide i…

Microbiological transformations. 30. Enantioselective hydrolysis of racemic epoxides: the synthesis of enantiopure insect juvenile hormone analogs (b…

1993

Abstract The enantioselective epoxide biohydrolysis of the racemic benzodioxole 6,7-epoxygeraniol derivative 1 has been achieved using the fungus A. niger . This new type of preparative scale bioconversion allows the synthesis of both enantiomers of Bower's compound, an analogue of insect juvenile hormone. Biological tests showed that the 6(R) enantiomer was about ten times more active than the 6(S) enantiomer against the yellow meal worm Tenebrio molitor .

Biomateriālu: Biodentīna un Minerāltrioksīda agregāta (MTA) izmantošana zobārstniecībā anonīmā aptauja

2020

Ievads: Šī pētījuma mērķis bija noskaidrot, kādu biomateriālu, MTA vai Biodentīnu ikdienā izmanto zobārsti Latvijā un kādi ir faktori to nosaka. Metodes: Šķērsgriezuma pētījums tika veikts starp zobārstniecības speciālistiem, kuri strādā dažādu Latvijas Republikas reģionu klīnikās. Anketa tika izveidota, lai iegūtu nepieciešamo informāciju par MTA un Biodentīna izmantošanu konservatīvajā zobārstniecībā un endodontijā. Pētījumu apstiprināja Latvijas Universitātes Kardioloģijas un reģeneratīvās medicīnas institūta zinātniskās izpētes ētikas komisija. Rezultāti: No respondentiem tika saņemtas 105 aizpildītas anketas, kuras arī tika iekļautas datu analīzē. Respondenti bija vispārējie zobārsti (…

Influence of Surface Charge and Polymer Coating on Internalization and Biodistribution of Polyethylene Glycol-Modified Iron Oxide Nanoparticles

2015

International audience; The aim of this study was to investigate the influence of the surface charge and coating of Superparamagnetic Iron Oxide Nanoparticles (SPIONs) on their in vitro and in vivo behaviors. Neutral and negatively-charged PEG-based SPIONs were synthesized and compared to Resovist (R), a carboxydextran-based SPION currently used in clinics. Their cytotoxicity, cell internalization, and potential as contrast agents for magnetic resonance imaging were assessed. Neutral pegylated SPIONs were internalized less readily by the reticuloendothelial system and showed a lower uptake by the liver, compared to negatively-charged SPIONs (with carboxydextran and PEG). These results sugge…

CMR 2005: 12.06: Ultra-small iron oxide nanoparticle (USPIO)-labeled baculoviruses as novel MRI agents for imaging viral vector biodistributionin vivo

2006

Granulocyte Colony-Stimulating Factor Nanocarriers for Stimulation of the Immune System (Part I): Synthesis and Biodistribution Studies

2018

In the field of cancer immunotherapy, an original approach consists of using granulocyte colony-stimulating factor (G-CSF) to target and activate neutrophils, cells of the innate immune system. G-CSF is a leukocyte stimulating molecule which is commonly used in cancer patients to prevent or reduce neutropenia. We focused herein on developing a G-CSF nanocarrier which could increase the in vivo circulation time of this cytokine, keeping it active for targeting the spleen, an important reservoir of neutrophils. G-CSF-functionalized silica and gold nanoparticles were developed. Silica nanoparticles of 50 nm diameter were functionalized by a solid phase synthesis approach. The technology enable…

Chemical composition of essential oil from Italian populations of Artemisia alba Turra (Asteraceae).

2012

The use of essential oils as chemotaxonomic markers could be useful for the classification of Artemisia species and to caracterize biodiversity in the different populations. An analysis of the chemical composition of four essential oils from Italian populations of Artemisia alba Turra (collected in Sicily, Marche and Abruzzo) was investigated. In this paper an in depth study of the significant differences observed in the composition of these oils is reported.