Search results for " LAB"

Capillaroscopic and histologic examination of the human labial mucosa: A new non invasive methodology compared with the histological exam

2005

The aim of our study is to compare the capillaroscopic examination in vivo with the histological examination in vitro of labial microcirculation in healthy subjects. Methods. Twenty-nine subjects (19 females, 10 males; mean±SD age 55.61±2.55; range 45-65 years) were examined in our laboratory. The characteristics of labial microcirculation were examined using computerised videomicroscopic techniques and histological exam. Results. The results obtained with both methods showed some analogies: in fact, the differences in capillary diameter were in the range of ±0.3 µ; regarding capillary density as well, a variation of ±2 capillaries per mm2 was found. Comparing the results obtained with both…

El capital psicológico del líder y su efecto en la capacidad de aprendizaje organizativo, la flexibilidad y el rendimiento laboral del empleado

2022

Colombia tiene como meta convertirse en el país con el mejor sistema educativo de América Latina para el año 2025. Para lograr dicho objetivo, el Ministerio de Educación de Colombia ha desarrollado diferentes estrategias para optimizar el capital humano. Las condiciones psicológicas de sus líderes deben facilitar la generación y capitalización del conocimiento en contextos como el educativo y mejorar la flexibilidad y el rendimiento laboral del empleado para intervenir y modificar estructuras administrativas que cada vez sean más horizontales. En el nivel organizacional, es importante evaluar el papel del capital psicológico del líder y su influencia en la capacidad de aprendizaje organizat…

Acomiadament per causes econòmiques: causes i control judicial després de la reforma de 2012

2017

Covalent modificaition of juvenile hormone binding proteins by photoaffinity labeling: An unexpected gel shift effect

1994

The 32 kD juvenile hormone binding protein (JHBP) and two 80 kD proteins in larval Manduca sexta hemolymph were labeled with [3H]FDK, a photoaffinity analog of methyl farnesoate (MF). The labeling could be completely displaced by a 30-fold excess of either MF or JH II, demonstrating that [3H]FDK binds specifically to the JH binding sites of the 32 kD JHBP and the 80 kD proteins. In addition, a high molecular-mass protein was labeled with [3H]FDK; labeling could be displaced by excess MF but not by JH II, demonstrating the selectivity in binding MF. The 32 kD JHBP also appeared to weakly bind the potent juvenoid, methoprene, at the JH binding site. Covalent modification by [3H]FDK induced a …

3'-Arylazido-beta-alanyl-2-azido ATP, a cross-linking photoaffinity label for F1ATPases.

1989

Abstract The synthesis of the 3′-arylazido-2-azido ATP derivative 3′-O-{3-[N-(4-azido-2-nitrophenyl)-amino]propionyl}2-azido-adenosine 5′-triphosphate (2,3′-DiN3ATP) is described. The bifunc­ tional photoreactive ATP analog is characterized spectroscopically. Photoaffinity labeling of F, ATPase from Micrococcus luteus by this analog results in the inactivation of the enzyme and in the formation of higher molecular weight cross-links,

Radioactive labeling of defined HPMA-based polymeric structures using [18F]FETos for in vivo imaging by positron emission tomography.

2009

During the last decades polymer-based nanomedicine has turned out to be a promising tool in modern pharmaceutics. The following article describes the synthesis of well-defined random and block copolymers by RAFT polymerization with potential medical application. The polymers have been labeled with the positron-emitting nuclide fluorine-18. The polymeric structures are based on the biocompatible N-(2-hydroxypropyl)-methacrylamide (HPMA). To achieve these structures, functional reactive ester polymers with a molecular weight within the range of 25,000-110,000 g/mol were aminolyzed by 2-hydroxypropylamine and tyramine (3%) to form (18)F-labelable HPMA-polymer precursors. The labeling procedure…

Tin compounds interaction with membranes of egg lecithin liposomes.

2007

This work is a continuation of earlier research concerning the influence of tin compounds on the dynamic properties of liposome membranes produced with lecithin hen egg yolks (EYL). The experiments were carried out at room temperature (about 25 ∞C). Four tin compounds were chosen, including three organic ones, (CH3)4Sn, (C2H5)4Sn and (C3H7)3SnCl, and one inorganic, SnCl2. The investigated compounds were admixed to water dispersions of liposomes. The content of the admixture changed within the range 0 mol-% to 11mol-% in proportion to EYL. Two spin probes were used in the experiment: 2,2,6,6-tetramethylpiperidine- 1-oxyl (TEMPO) and 2-ethyl-2-(15-methoxy-15-oxopentadecyl)-4,4-dimethyl-3-oxaz…

The Influence of Natural and Model Forms of Humic Acids on the Dynamic Parameters of Model Membranes

2016

Abstract In this paper the influence of humic acid concentrations extracted from Histosols (HA-A) and their model forms (HA-B) separated from humic substances commercially produced by Carl Roth GmbH + Co.KG on the dynamic properties of liposome membranes was determined. Differences in the quality of the humic acids (HA-A and HA-B) were determined by the 1HNMR and FTIR methods. Liposomes from the sonication of egg yolk lecithin (EYL) in an aqueous solution and synthetic Dipalmitoylphosphatidylcholine (DPPC) were used. Fluidity of liposome membranes was determined by the EPR technique with spin probes (TEMPO, 16DOIXYL). The electrical parameters of membranes were found using a Keithley 6517 e…

Biochemistry and cell biology of silica formation in sponges

2003

The main inorganic material forming the skeletal elements in Demospongiae as well as in Hexactinellida, the spicules, is amorphous silica. The spicules occur in the cytoplasm and the extracellular space and also in the nucleus (as silicate crystals) of some sponge cells; the function in the latter compartment is unknown. Recent evidence shows that the formation of spicules is mediated by the enzyme silicatein. The cDNA as well as the gene encoding this enzyme was cloned from Suberites domuncula. The recombinant silicatein catalyzes the syn- thesis of amorphous silicate using tetraethoxysilane as substrate. The enzyme is dependent on ferric iron. Silicatein also has proteolytic (cathepsin-li…

Cytochemical techniques for zinc and heavy metals localization in nerve cells

2002

Zinc is one of the most abundant oligoelements in the living cell. It appears tightly bound to metallothioneins, loosely bound to some metalloproteins and nucleic acids, or even as free ion. Small amounts of zinc ions (in the nanomolar range) regulate a plentitude of enzymatic proteins, receptors, and transcription factors; thus, cells need accurate homeostasis of zinc ions. Some neurons have developed mechanisms to accumulate zinc in specific membrane compartments ("vesicular zinc") which can be revealed using histochemical techniques. This article is a short report on the different direct-indirect experimental approaches for zinc and heavy metal detection in neurons. Substances giving a b…