Search results for "RELEASE"

Selective adsorption of oppositely charged PNIPAAM on halloysite surfaces: a route to thermo-responsive nanocarriers.

2018

Halloysite nanotubes were functionalized with stimuli-responsive macromolecules to generate smart nanohybrids. Poly(N-isopropylacrylamide)-co-methacrylic acid (PNIPAAM-co-MA) was selectively adsorbed into halloysite lumen by exploiting electrostatic interactions. Amine-terminated PNIPAAM polymer was also investigated that selectively interacts with the outer surface of the nanotubes. The adsorption site has a profound effect on the thermodynamic behavior and therefore temperature responsive features of the hybrid material. The drug release kinetics was investigated by using diclofenac as a non-steroidal anti-inflammatory drug model. The release kinetics depends on the nanoarchitecture of th…

Relationship between particle size and dissolution rate of bulk powders and sieving characterized fractions of two qualities of orthoboric acid

1996

Drug Dev. Ind. Pharm. ISI Document Delivery No.: VN279 Times Cited: 1 Cited Reference Count: 22 Tromelin, A Habillon, S Andres, C Pourcelot, Y Chaillot, B; International audience; We have carried out a study of the particle size distribution and aqueous dissolution rate of two commercially available qualities of orthoboric acid, labeled ''crystal'' (ABC) and ''powder'' (ABP). In a previous work, we have shown that the two commercial qualities of orthoboric acid chosen as model compound (''powder'' and ''crystal'') are related to the same crystal network in spite of their different names. However, these two qualities have very different size particle distributions, as previously determined b…

Ability of the T cell-replacing polyanion dextran sulfate to trigger the alternate pathway of complement activation.

1973

Dextran sulfate (DS) consumed C3 in C4 deficient guinea pig serum. This temperature-dependent reaction required Mg++ ions and could therefore be blocked by EDTA. Isolated C3 was not influenced by DS, but serum factors were required for C3 consumption. The C3 proactivator as well as C3 were converted to their activated state by DS in guinea pig and human serum, as revealed by immunoelectrophoretical analysis. DS generated anaphylatoxin activity in serum. It is concluded that DS activates C3 via the alternate pathway of complement activation. This potency of the polyanion might serve as a tentative explanation for its T cell-replacing effect in an antibody-forming system, which was reported b…

2021

The controlled release of antibiotics prevents the spread of pathogens and thereby improves healing processes in regenerative medicine. However, high concentrations may interfere with healing processes. It is therefore advantageous to use biodegradable materials for a controlled release. In particular, multilayer materials enable differential release at different surfaces. For this purpose, collagen sheets of different properties can be bonded by photochemical crosslinking. Here, we present the development and application of an easily accessible, additively manufactured sample holder to study the controlled release of vancomycin from modularly assembled collagen laminates in two directions.…

Nanosponges for the protection and release of the natural phenolic antioxidants quercetin, curcumin and phenethyl caffeate

2020

The inclusion of polyphenols into nanoporous materials may significantly improve their application as radical trapping agents for therapeutic purposes. In the present work, nanosponges based on hypercross- linked cyclodextrins and calixarenes (NS1–NS3) were used as carriers of three natural phenolic antioxidants: quercetin (Que), curcumin (Cur) and phenethyl caffeate (Phec). Good w/w loadings, namely 7.3% for the Que–NS1 composite, 17.3% for Cur–NS2 and 12.9% for Phec–NS3, were achieved. The release kinetics and the inhibition rate constants (kinh) of the reaction with alkylperoxyl radicals (ROO.) in 0.1 M phosphate buffer solutions at pH 7.4 were studied and indicated better antioxidant ac…

Algae and Their Extracts in Medical Treatment

2018

Scientific efforts undertaken in recent decades have undoubtedly proven that algae are an inestimable and, what is more, important renewable source of hundreds of chemical compounds characterized by a wide spectrum of biological activity. Polysaccharides, phenolic compounds and their derivatives, pigments, proteins, lipids, and fatty acids are the substances that can be isolated from seaweeds, possessing antimicrobial, antiviral, antifungal, antilipidemic, antitumor, antidiabetic, anticoagulant, antioxidant, and antiallergic properties, which can be successfully utilized for human needs. The majority of attention has been focused on marine polysaccharides and their application in medicine a…

Diagnostyka sądowo-kryminalna w orzekaniu i wykonywaniu warunkowego przedterminowego zwolnienia w teorii i praktyce sądowej – raport z badania

2019

Niniejsza praca stanowi podsumowanie projektu badawczego Diagnostyka sądowo-kryminalna w orzekaniu i wykonywaniu warunkowego przedterminowego zwolnienia w teorii i praktyce sądowej, zrealizowanego przez Instytut Wymiaru Sprawiedliwości. Celem projektu, w tym w szczególności przeprowadzonego w jego ramach badania empirycznego, było (m.in.) zweryfi kowanie twierdzenia, w myśl którego w pracy administracji jednostek penitencjarnych oraz sądów penitencjarnych występują niedostatki profesjonalnej i pogłębionej prognozy kryminologicznej. W ramach badania empirycznego przeprowadzono analizę 540 spraw, w których w drugim kwartale 2013 r. pozytywnie rozpatrzono wnioski o udzielenie skazanym warunkow…

Testing standard and nonstandard neutrino physics with cosmological data

2012

Cosmological constraints on the sum of neutrino masses and on the effective number of neutrino species in standard and nonstandard scenarios are computed using the most recent available cosmological data. Our cosmological data sets include the measurement of the baryonic acoustic oscillation (BAO) feature in the data release 9 CMASS sample of the baryon oscillation spectroscopic survey. We study in detail the different degeneracies among the parameters, as well as the impact of the different data sets used in the analyses. When considering bounds on the sum of the three active neutrino masses, the information in the BAO signal from galaxy clustering measurements is approximately equally pow…

Acetylcholine via Muscarinic Receptors Inhibits Histamine Release from Human Isolated Bronchi

1997

Human bronchi were incubated in organ baths to measure histamine release. The calcium ionophore A23187 (10 mumol/L; 1 min) stimulated histamine release by 148 +/- 28% (n = 11) above the prestimulation level but was ineffective in epithelium-denuded bronchi. Neither bradykinin (0.1 mumol/L) nor compound 48/80 (10 micrograms/ml) triggered the release of histamine from epithelium-intact bronchi. Acetylcholine did not affect spontaneous histamine release (about 2 nmol/g x 5 min) but inhibited A23187-evoked histamine release in an atropine-sensitive manner. Already a concentration as low as 0.1 nmol/L acetylcholine was effective, the maximal inhibition (by 89%) occurred at 100 nmol/L, whereas a …

Performance of QuantiFERON-TB Gold Plus for detection of latent tuberculosis infection in pregnant women living in a tuberculosis- and HIV-endemic se…

2017

We evaluated the performance of QuantiFERON-TB Gold Plus (QFT-Plus), which includes two Mycobacterium tuberculosis antigen formulations (TB1 and TB2), for detection of latent tuberculosis infection during pregnancy. Eight-hundred-twenty-nine Ethiopian pregnant women (5.9% HIV-positive) were tested with QFT-Plus, with bacteriological sputum analysis performed for women with clinically suspected tuberculosis and HIV-positive women irrespective of clinical presentation. QFT-Plus read-out was categorized according to the conventional cut-off (0.35 IU/ml) for both antigen formulations. In addition, we analysed the distribution of QFT-Plus results within a borderline zone (0.20–0.70 IU/ml), and i…