Search results for "probe"
showing 10 items of 534 documents
Preparation and characterization of Al2O3 supported TiO2 catalysts employed for 4-nitrophenol photodegradation in aqueous medium
1998
Abstract In this paper the preparation and some bulk and surface characterizations of set of Al2O3 supported TiO2 photocatalysts are reported. The powders were home prepared by a wet impregnation method using titanium (IV) isopropylate. The impregnation was followed by thermal treatments and this procedure was repeated several times in order to obtain samples with different amounts of TiO2. The solids were characterized by X-ray diffraction, specific surface area determination, scanning electron microscopy coupled with an electron microprobe used in an energy-dispersive mode and diffuse reflectance spectroscopy. Moreover, all of them were tested as photocatalysts by using different kinds of…
Highly selective fluorescence detection of hydrogen sulfide by using an anthracene-functionalized cyclam-CuII complex
2013
An anthracene-functionalised cyclam-copper(II) complex for the detection of HS- in aqueous environments has been prepared. This probe displays poor fluorescence but can selectively and sensitively detect HS- anions in water over other anions, biothiols and common oxidants such as H2O2 through remarkably enhanced emission. This turn-on response in the presence of the HS- anion is ascribed to a demetallation reaction that inhibits emission quenching observed in the initial complex as a result of the presence of the paramagnetic Cu2+ centre. Moreover, real-time fluorescence imaging measurements confirm that probe [Cu(1)](2+) can be easily used to detect intracellular HS- at micromolar concentr…
Micellization and Micellar Structure of a Poly(ethylene oxide)/Poly(propylene oxide)/Poly(ethylene oxide) Triblock Copolymer in Water Solution, As St…
1997
The micellization of the triblock copolymer Pluronic P85 (poly(oxyethylene)27/poly(oxypropylene)39/poly(oxyethylene)27) in aqueous solution was followed vs temperature and addition of aliphatic alcohols, using the spin probe technique. Different types of probes properly chosen (spin-labeled (SL) poly(oxyethylene(4))nonylphenol, SL-Pluronic L62, TEMPO-laurate, TEMPO-hexanoate, CAT 4, CAT 8, CAT 11, CAT 16, and 5-, 7-, 10-, and 12-doxylstearic acids) provided information about the micellar structure (polarity, viscosity, and order degree) at different radial locations. Micellization was found to be low at room temperature, even for 10% aqueous solutions, but strongly increasing with temperatu…
Probing the internal environment of PVP networks generated by irradiation with different sources
2010
Poly(N-vinyl-2-pyrrolidone) (PVP) hydrogels have been synthesised from the aqueous solutions of the same linear polymer by two different radiation sources: electron beams and UV rays. The present investigation couples conventional hydrogel characterisation techniques with the study of the partition equilibria, fluorescence behaviour and release of two different molecular probes, 1-anilino-8-naphthalene sulphonate (ANS) and Thioflavin T (ThT). The two probes have comparable molecular weight and different structural and optical properties. The chemical networks produced upon irradiation in different experimental conditions presented quite distinctive mechanical spectra, yielded to different…
Solution versus Fluorous versus Solid-Phase Synthesis of 2,5-Disubstituted 1,3-Azoles. Preliminary Antibacterial Activity Studies
2009
A small library of compounds with an oxa(thia)zole scaffold and structural diversity in both positions 2 and 5 has been synthesized. Double acylation of a protected glycine affords intermediate α-amido-β-ketoesters, which in turn can be dehydrated to afford 1,3-oxazoles or reacted with Lawesson’s reagent to furnish 1,3-thiazoles. This procedure was designed with its adaptation to fluorous techniques in mind. Thus, when a protected glycine with a fluorous tag in the ester moiety is used as a starting material, the synthesis can be easily completed without column chromatography purification of intermediate compounds with good to excellent yields, thus affording a suitable entry to the prepara…
Development of fluorogenic probe-based PCR assays for the detection and quantification of bovine piroplasmids.
2009
This paper reports two new quantitative PCR (qPCR) assays, developed in an attempt to improve the detection of bovine piroplasmids. The first of these techniques is a duplex TaqMan assay for the simultaneous diagnosis of Babesia bovis and B. bigemina. This technique is ideal for use in South America where bovids harbour no theilerids. The second technique, which is suitable for the diagnosis of both babesiosis and theileriosis worldwide, involves fluorescence resonance energy transfer (FRET) probes. In FRET assays, Babesia bovis, B. divergens, Babesia sp. (B. major or B. bigemina), Theileria annae and Theileria sp. were all identifiable based on the melting temperatures of their amplified f…
Fluorescence In Situ Hybridization (FISH) on Formalin-Fixed Paraffin-Embedded (FFPE) Tissue Sections
2011
Fluorescence In Situ Hybridization (FISH) is a powerful technique for localizing specific DNA targets directly in the fixed tissue or cells. Bacterial artificial chromosome (BAC) as well as commercial probes, which could be supplied ready for use or concentrated and must be diluted following the manufacturers instructions, can be used. The technique requires 2 days, as an overnight incubation of the FISH probes is needed for optimal hybridization. The critical steps include deparaffinization of tissue sections, optimal pretreatment (target retrieval and protein digestion), and probe hybridization. In this chapter, the described FISH protocol provides a methodology for analyzing the cytogene…
Direct detection of repetitive, whole chromosome paint and telomere DNA probes by immunogold electron microscopy
1993
Biotinylated repetitive, whole chromosome paint and telomere DNA probes were investigated at the electron microscope level after non-isotopic in situ hybridization and direct immunogold detection. The protocol described allowed the visualization of a biotinylated chromosome 1 specific satellite DNA probe in the light microscope without silver intensification. This sensitive method was exploited to analyse factors contributing to signal strength in immunogold chromosome painting. Furthermore, it allowed us to investigate the distribution of (TTAGGG)n telomere repeats in human metaphase chromosomes and interphase nuclei. Telomeric and internal (TTAGGG)n repeats were detected at high spatial r…
Recent advances in smart biotechnology: Hydrogels and nanocarriers for tailored bioactive molecules depot
2017
Over the past ten years, the global biopharmaceutical market has remarkably grown, with ten over the top twenty worldwide high performance medical treatment sales being biologics. Thus, biotech R&D (research and development) sector is becoming a key leading branch, with expanding revenues. Biotechnology offers considerable advantages compared to traditional therapeutic approaches, such as reducing side effects, specific treatments, higher patient compliance and therefore more effective treatments leading to lower healthcare costs. Within this sector, smart nanotechnology and colloidal self-assembling systems represent pivotal tools able to modulate the delivery of therapeutics. A comprehens…
Hybrid, multiplexed, functional DNA nanotechnology for bioanalysis
2015
We herein aim to report on the fabrication of DNA nano-heterostructures usable as a robust multi-functional analytical system to obtain multiple and complex data in parallel format from a single sample with unprecedented analytical performances. The ability of chemical information contained in the sequences of programmed DNA structures to organize matter made DNA become a unique material in “the nanoworld”. Such carefully designed DNA nanostructures can then be functionalized/templated with different biomolecules/nanomaterials as different as nanoparticles, nanowires, organic molecules, peptides, and proteins with controlled spacing on the nanometer scale (<10 nm). In this way, it is possib…