Search results for "reparation"
showing 10 items of 944 documents
Analysis of Trace Pharmaceuticals and Related Compounds in Municipal Wastewaters by Preconcentration, Chromatography, Derivatization, and Separation …
2014
A significant portion of pharmaceuticals and other organic chemicals consumed by people and animals are released into municipal wastewater treatment plants. Most of them are degraded during the wastewater treatment processes, but some of them degrade only partially and may be widely transported and dispersed into the aquatic environment. This is why efficient and fast analytical methods are needed for detection of organic compounds in wastewaters at trace levels. Because wastewaters often consist of complex matrices and high-molecular mass materials, e.g., lignocellulosic biomass, which may bring challenges to the sample preparation procedures, efficient pre-concentration methods such as so…
Fractionation of mercury in sediments during draining of Augusta (Italy) coastal area by modified Tessier method
2013
Abstract A modified Tessier method was applied to sediments dredged from Augusta (Italy) coastal area with the purpose of establishing the amount and the forms in which mercury is present in the different sediment fractions. The mercury fractionation was made by measuring the concentration of the metal ion on the solutions and directly on the sediment fractions obtained by sequential extraction. The measurements on the solutions as well as that on the solid fractions were carried out by using a Direct Mercury Analyser, DMA 80. This new instrument does not require sample preparation, and gives results comparable to those obtained with CV-AAS and ICP-MS and few minutes are necessary for each …
Derivatization of ephedrine with o-phthaldialdehyde for liquid chromatography after treatment with sodium hypochlorite.
2000
The usefulness of the reaction with NaClO followed by derivatization with o-phthaldialdehyde (OPA) and N-acetyl-L-cysteine (NAC) has been investigated for the chromatographic analysis of ephedrine. The influence of parameters affecting the two-stage reaction has been evaluated, including concentration of NaClO, time of reaction, temperature and pH. On the basis of these studies, conditions for the pre-column and (automated) post-column determination of ephedrine are presented. The described conditions have been applied to the measurement of ephedrine in the concentration intervals 0.2-20.0 microg/ml and 2.0-50.0 microg/ml for the pre-column and post-column methods, respectively. The possibi…
Swellable microparticles containing Suprofen: evaluation of in vitro release and photochemical behaviour
1998
Suprofen, an anti-inflammatory drug was incorporated in polymer networks based on biocompatible macromolecules, such as alpha,beta-polyasparthydrazide (PAHy) and alpha,beta-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) crosslinked by glutaraldehyde or gamma-rays, respectively. Swelling tests carried out in aqueous media showed that pH value affects the swelling degree of the prepared hydrogels. In vitro release tests were performed in simulated gastrointestinal fluids (pH 1/6.8) using the pH variation method and in phosphate-buffered saline, pH 7.4. Experimental data indicated that Suprofen was released in a sustained way both from PAHy and PHEA microparticles. Further, incorporation of Suprof…
Spectroscopic studies of 5,5′-dimethoxy-3,3,′-disulfobutyl-9-ethylthiacarbocyanine (DDTC) in solutions and immobilized in sol-gel matrices
1998
Abstract Absorption spectra of 5,5′-dimethoxy-3,3,′-disulfobutyl-9-ethylthiacarbocyanine (DDTC) in aqueous solutions and immobilized in xerogels prepared by the sol-gel method were obtained. Influence of pH, detergent (Triton X-100), ethanol addition and sol-gel preparation method on the dye aggregation equilibria and its photostability were investigated. In liquid solutions lowering of pH, as well as addition of the detergent, shift the aggregation equilibrium towards the DDTC monomeric form. However, while more acidic conditions result in a decrease of the dye stability, addition of the detergent has a slightly stabilizing effect on the dye. However, addition of ethanol drastically reduce…
Micellar electrokinetic chromatography of polyamines and monoacetylpolyamines
2001
A selective procedure for qualitative and quantitative analysis of ten polyamines by micellar electrokinetic chromatography (MEKC) was developed. Benzoylated polyamines and acetylpolyamines in micellar phase of SDS (10 mM) were separated at 25 degrees C by 20 mM borate buffer pH 8.5, containing 8% ethanol, with an applied voltage of 25 kV (5 microA) and then detected at 198 nm. The experimental factors and operational parameters were optimized by performing analysis at different surfactant concentrations, pH, voltage and temperature with and without ethanol. The repeatibility of migration times and peak heights is a peculiarity of the method here described.
Medicinal plants and their uses recorded in the Archives of Latvian Folklore from the 19th century.
2020
Abstract Ethnopharmacological relevance The records of folk medicine present historical evidence of medicinal plant usage in the territory of Latvia and describe native and imported plants and plant products that were used as medicine. Aim of the study To collect and analyse the ethnobotanical knowledge found in records of Latvian folk medicine available in the Archives of Latvian Folklore. Materials and methods Following the International Classification of Primary Care, plant uses were grouped into one of the 17 categories based on the body systems and psychological and social problems. Each plant was identified by its scientific name according to The Plant List website. Additionally, the …
LABA/LAMA fixed-dose combinations in patients with COPD: A systematic review
2018
Paola Rogliani,1 Luigino Calzetta,1 Fulvio Braido,2 Mario Cazzola,1 Enrico Clini,3 Girolamo Pelaia,4 Andrea Rossi,5 Nicola Scichilone,6 Fabiano Di Marco7 1Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy; 2Department of Internal Medicine, IRCCS San Martino Genoa University Hospital, Genoa, Italy; 3Department of Medical and Surgical Sciences, University of Modena and Reggio Emilia, Modena, Italy; 4Department of Medical and Surgical Sciences, Section of Respiratory Diseases, Magna Græcia University, Catanzaro, Italy; 5Pulmonary Unit, University of Verona, Verona, Italy; 6Department of Internal Medicine, University of Palermo, Palermo, Italy; 7…
Exopeptidase digestion in combination with field desorption mass spectrometry for amino acid sequence determination
1982
Numerous studies have been devoted in the last years to the development of mass spectrometric methods for the sequence determination of peptides [ 1,2]. Most advanced among this work has been so far the rigorous chemical derivatization of oligopeptides to achieve sufficient volatility for the application of conventional (electron impact, EI) mass spectrometry [2-41. For example, the analysis by gas chromatography-mass spectrometry (GC-MS) of mixtures of oligopeptide fragments derivatized after chemical or enzymatic hydrolysis of polypeptides has been successfully used for sequence determinations [2,5]. Major limitations of this approach are that only small peptide derivatives are amenable t…
Vertical preparation for fixed prosthesis rehabilitation in the anterior sector
2015
This clinical report describes a biologically oriented preparation technique (BOPT) for teeth and an implant for the esthetic rehabilitation of the maxillary anterior sector. The technique was designed to create an anatomic crown with a prosthetic emergence profile that simulated the shape of the natural tooth.