UK PubMed Central (United Kingdom)

AbstractX-ray diffraction analysis of pressure-induced structural changes in the Aequorea yellow fluorescent protein Citrine reveals the structural basis for the continuous...Full Text Available

Science.gov (United States)

Autofluorescence spectroscopy has been a widely explored technique for in vivo and noninvasive diagnosis of pre-cancer lesions in epithelium where 90% cancers originate. For extracting more accurate fluorescence information for cancer diagnosis, depth-resolved fluorescence measurements are crucial to assess NADH and FAD in non-keratinized epithelial layer and collagen in stromal layer, respectively. In this study, we achieved the depth-resolved fluorescence spectral measurements of squamous epithelial tissue based on confocal technique. We found that in non-keratinized epithelial layer the fluorescence signals excited at 405 nm were the combination of NADH and FAD fluorescence and could be used for evaluating the redox ratio. Moreover, we found that confocal time-resolved autofluorescence measurements of epithelial tissue with 405 nm excitations could provide the information on the ...

British Library Electronic Table of Contents (United Kingdom)

A comparative study on the interaction of (PEG-co-P(FA/SC)-co-PEG) triblock copolymer with bovine and human insulins was carried out using isothermal titration calorimetry (ITC), circular dichroism (CD), and fluorescence spectroscopy. ITC data show that the copolymer has a low affinity for both proteins, with an association constant of about 7?9?103?M ?1. Results also show that binding is enthalpically driven, and disfavored by conformational entropy. CD spectroscopy studies reveal a small increase in the helical content and a decrease in ?-structure as well as random coil in both proteins. Acrylamide quenching experiments display reduced accessibility of tyrosines, while intrinsic fluorescence spectra show lower tyrosine emission. Furthermore, thermal unfolding experiments, studied by far...

Science.gov (United States)

Progress on Ultrasensitive fluorescence detection of DNA is briefly described. (CBS)

Science.gov (United States)

... significantly lower limits of detection. The complex fluorescence spectra of these constructs indicated that only a portion ...

International Nuclear Information System (INIS)

The photophysical investigation of different para-substituted tetraphenylporphyrins (TP), viz., meso-tetra(4'-hydroxyphenyl)-21H-23H-porphyrin(1),meso-tetrakis (4'-hex-5-enyloxyphenyl)-21H-23H-porphyrin(2), meso-tetrakis(4'-oct-7-enyloxyphenyl)-21H-23H-porphyrin(3) and meso-tetrakis(4'-undecyloxyphenyl)-21H-23H-porphyrin (4) revealed that except for quantum yield (#phi#) the para-substitution has little effect on any other photophysical properties like lifetime, excitation, emission wavelength, etc. The host-guest type interactions of these tetraarylporphyrins (TP 1-4), with [60]-fullerene (F) have been studied with "1H NMR and fluorescence spectrometric techniques in carbon tetrachloride medium. Fluorescence studies revealed that the Q band of the TPs was sufficiently quenched upon addition of F. All the fullerene/porphyrin systems were found to produce stable complexes with 1:1 stoichiometry. Binding ...

International Nuclear Information System (INIS)

Focused-ion beam (FIB) milling provides rapid fabrication of individual cylindrical submicrometer channels with reproducible dimensions (#+-#5% diameters) through 8-#mu#m thick poly(methylmethacrylate) (PMMA) films. PMMA films are spincast on sacrificial Si carriers and sputter-coated with Au before the 30-kV gallium FIB milling process. By adding a trace amount of poly(ethyleneoxide) and poly(dimethylsiloxane) to the PMMA solution before casting, the films can be released for subsequent mounting in microfluidic devices to create hybrid microfluidic-nanofluidic multilevel architectures. In situ FIB sectioning demonstrates the smooth cylindrical surface within the pore. Placing a milled film in contact with an aqueous fluorescein solution fills the channel by capillary action, as verified by confocal fluorescence microscopy. Confocal fluorescence of dyed films reveals that the pores span the thickness of the PMMA film. Small ...

British Library Electronic Table of Contents (United Kingdom)

A stable BSA blocking poly(dimethylsiloxane) (PDMS) microchannel was prepared based on in situ synthesized PDMS-gold nanoparticles composite films. The modified microchip could successfully suppress protein adsorption. The assembly was followed by contact angle, charge-coupled device (CCD) imaging, electroosmotic flow (EOF) measurements and electrophoretic separation methods. Contact angle measurements revealed the coated surface was hydrophilic, water contact angle for coated chips was 45.2^o compared to a water contact angle for native PDMS chips of 88.5^o. The coated microchips exhibited reproducible and stable EOF behavior. With FITC-labeled myoglobin incubation in the coated channel, no fluorescence was observed with CCD image, and the protein exhibited good electrophoretic effect in ...

British Library Electronic Table of Contents (United Kingdom)

Heme peroxidases are a class of multifunctional redox-active proteins found in all organisms. We recently cloned, expressed, and characterized an ascorbate peroxidase from Leishmania major (LmAPX) that was capable of detoxifying hydrogen peroxide. Localization studies using green fluorescent protein fusions revealed that LmAPX was localized within the mitochondria by its N-terminal signal sequence. Subcellular fractionation analysis of the cell homogenate by the Percoll density-gradient method and subsequent Western blot analysis with anti-LmAPX antibody further confirmed the mitochondrial localization of mature LmAPX. Submitochondrial fractionation analysis showed that the mature enzyme (?3.6?kDa shorter than the theoretical value of the whole gene) was present in the intermembrane space ...

Energy Technology Data Exchange (ETDEWEB)

The large aggregating proteoglycan aggrecan is a major structural component of the extracellular matrix of articular cartilage. Recent cDNA cloning of the human aggrecan gene (AGC1) reveals a core protein of at least 2316 amino acids characterized by several distinct structural domains. Two globular domains, termed G1 and G2, are present at the amino terminus of the molecule and a third, termed G3, is present at the carboxy terminus. The G1 domain is homologous in structure to the cartilage link protein and accounts for the aggregating potential of aggrecan through its ability to interact with hyaluronic acid. The aggrecan gene is known to consist of 15 exons, with each exon encoding a distinct functional region of the mature protein. However, while the link protein gene is known to reside on chromosome 5 in the human, the location of the aggrecan gene is currently undetermined in any species. The probe (pAGG2) for the aggrecan gene was mapped on chromosome band ...

Energy Technology Data Exchange (ETDEWEB)

The Drosophila hairy gene encodes a basic helix- loop-helix protein that functions in at least two steps during Drosophila development: (1) during embryogenesis, when it partakes in the establishment of segments, and (2) during the larval stage, when it functions negatively in determining the pattern of sensory bristles on the adult fly. In the rat, a structurally homologous gene (RHL) behaves as an immediate-early gene in its response to growth factors and can, like that in Drosophila, suppress neuronal differentiation events. Here, the authors report the genomic cloning of the human hairy gene homolog (HRY). The coding region of the gene is contained within four exons. The predicted amino acid sequence reveals only four amino acid differences between the human and rat genes. Analysis of the DNA sequence 5[prime] to the coding region reveals a putatitve untranslated exon. To increase the value of the HRY gene as a genetic marker and to assess ...

UK PubMed Central (United Kingdom)

The utility of a two-photon optical fiber fluorescence probe (TPOFF) for sensing and quantifying tumor fluorescent signals was tested in vivo. Xenograft tumors were developed in athymic mice using MCA207...Full Text Available

Science.gov (United States)

The principles of radionuclide excitation of X-ray fluorescence radiation and its application in

Science.gov (United States)

Aug 1, 1972 ... The principles of radionuclide excitation of X-ray fluorescence radiation and its application in analytic chemistry are discussed.

International Nuclear Information System (INIS)

Dysprosium ion doped fluorophosphate glasses with compositions of PKMAFDy: (56-x/2) P2O5+17K2O+8Al2O3+(15-x/2)MgO+4AlF3+xDy2O3 (x=0.01, 0.05, 0.1, 1.0 and 2.0 mol%) have been prepared by melt quenching technique and are characterized by optical absorption, emission spectra and fluorescence lifetime measurements. The observed bands in the absorption spectrum are analysed by using free-ion Hamiltonian (HFI) model. The Judd-Ofelt (JO) analysis has been performed and the intensity parameters (??, ?=2, 4, 6) have been evaluated that are used to predict radiative properties. From emission spectra, the effective bandwidth (??eff) and the stimulated emission cross-section (?(?p)) were evaluated. The fluorescence decay from the 4F9/2 level of Dy3+ ions have been measured by monitoring the intense 4F9/2#->#6H13/2 transition (573 nm). The lifetimes (?) are found to decrease with increasing concentration due to concentration quenching. The decay curves ...

Energy Technology Data Exchange (ETDEWEB)

This work analyzes the unoptimized prototype triode-sputtered, 150 microns thick tantalum coatings deposited with a 2.5 microns niobium underlayer on the bore of a large-diameter A723 steel cylinder. The coating was deposited for wear and erosion protection by Pacific Northwest National Laboratory. The phase determination was based on X ray diffraction analysis, wavelength dispersive X ray fluorescence analysis, energy dispersive X ray analysis, and hardness and electrical resistivity measurements. Both X ray diffraction and radius-of- curvature methods were used to determine residual stresses. A locally developed high-resolution pole figure technique was used to perform texture analysis. The post-firing, debonded coating showed alpha-tantalum, preferred 110 orientation, high surface stresses, tantalum oxides, entrapped krypton sputtering gas, interstitial oxygen, and other impurities. The surface and subsurface pole figures revealed broadened ...

Energy Technology Data Exchange (ETDEWEB)

Radixin is a cytoskeletal protein that may be important in linking actin to the plasma membrane. Recent cloning of the murine and porcine radixin cDNAs revealed a protein highly homologous to ezrin and moesin. The authors have cloned and sequenced the human radixin cDNA and found the predicted amino acid sequence for the human protein to be nearly identical to those predicted for radixin in the two other species. By Southern analyses of Chinese hamster x human somatic cell hybrid DNA and of PCR products derived from hybrids, the coding gene (RDX) was mapped to 11q. Fluorescence chromosomal in situ hybridization with a cDNA plasmid further localized this gene to band 11q23. However, PCR amplification with [open quotes]radixin-specific[close quotes] primers on the hybrid DNA panel yielded an additional, very similar DNA sequence that was further characterized by direct sequencing of PCR products. This sequence represents a truncated version and ...

Energy Technology Data Exchange (ETDEWEB)

The chicken extracellular matrix glycoprotein ES/130 is necessary for epithelial-mesenchymal transformation in the developing hear and is also expressed in noncardiac chicken tissues such as limb and notochord. We have identified hES, the human homology of chicken ES/130. Fluorescence in situ hybridization analysis (FISH) localizes hES to human chromosome 20p11.2-p12. FISH analyses of individuals with 20p12 deletions and affected by Alagille syndrome exclude hES as a candidate gene for this disorder. Reverse transcriptase-polymerase chain reaction studies reveal that hES is expressed in both fetal and adult human tissues and that hES expression in the left ventricle is increased in the failing adult heart. Further studies will evaluate how hES mutations may relate to congenital human cardiac and skeletal anomalies as well as cardiac remodeling in the adult. 16 refs., 2 figs.

International Nuclear Information System (INIS)

Published in summary form only.

International Nuclear Information System (INIS)

Slovak 1973. 164 p. Czechoslovakia Havranek, E. Bumbalova, A. Svitel,

Science.gov (United States)

... NONDESTRUCTIVE DETERMINATION OF AIRBORNE LEAD PARTICULATES BY THE RADIONUCLIDE X-RAY FLUORESCENCE ANALYSIS. ...

Energy Technology Data Exchange (ETDEWEB)

Four techniques for using LIDAR in Search and Rescue Operations will be discussed. The topic will include laser retroreflection, laser-induced fluorescence in the visible, laser-induced fluorescence during daylight hours, and laser-induced fluorescence in the uv. These techniques use high-repetition rate lasers at a variety of frequencies to induce either fluorescence in dye markers or retroreflection from plastic corner cubes on life preservers and other emergency markers.

International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The author's achievements in the title field are summarized and discussed. The following topics are dealt with: (i) principles of radionuclide X-ray fluorescence analysis; (ii) mathematical methods in X-ray fluorescence analysis; (iii) Ross differential filters; (iv) application of radionuclide X-ray fluorescence analysis in the coal industry (with emphasis on the determination of the ash content, sulfur content, and arsenic content of coal); and (v) evaluation of the X-ray fluorescence analyzer from the radiological safety point of view. (P.A.).

Science.gov (United States)

BackgroundIn recent years, near-infrared fluorescence (NIRF)-labeled iron nanoparticles have been synthesized and applied in a number of applications, including the labeling of human cells for monitoring the engraftment process, imaging tumors, sensoring the in vivo molecular environment surrounding nanoparticles and tracing their in vivo biodistribution. These studies demonstrate that NIRF-labeled iron nanoparticles provide an efficient probe for cell labeling. Furthermore, the in vivo imaging studies show excellent performance of the NIR fluorophores. However, there is a limited selection of NIRF-labeled iron nanoparticles with an optimal wavelength for imaging around 800 nm, where tissue autofluorescence is minimal. Therefore, it is necessary to develop additional alternative NIRF-labeled iron nanoparticles for application in this area.ResultsThis study manufactured 12-nm DMSA-coated Fe3O4 nanoparticles labeled with a near-infrared fluorophore, IRDye800CW ...

Energy Technology Data Exchange (ETDEWEB)

We report on the single and double multiphoton ionization of ground state Sr atoms observed in an atomic beam experiment with laser pulses of {approx}5 ns duration, maximum intensity {approx}4 x 10{sup 11} W cm{sup -2} and within the 710-740 nm wavelength range. The Sr{sup +} spectrum consists of two strong lines originating from three-photon resonant four-photon ionization of bound states, a number of weak autoionizing resonances and a broad line due to four-photon excitation of the doubly excited 5p{sup 2} {sup 1}S{sub 0} state. The latter, along with a strong, broad and structured spectral feature, is also evident in the wavelength dependence of the doubly charged Sr{sup 2+} ion. A weakly evident but reproducible inflection point ('knee' structure) appears in the intensity dependence of the Sr{sup 2+} yield at the location of the 5p{sup 2} {sup 1}S{sub 0} resonance. A complementary fluorescence experiment revealed the ...

UK PubMed Central (United Kingdom)

An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly...Full Text Available

UK PubMed Central (United Kingdom)

We have measured the forward and reverse rates of the allosteric transition of hemoglobin A with three CO molecules bound by using modulated excitation coupled with fluorescence quenching of the DPG...Full Text Available

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of iron, calcium, potassium, copper, manganese and zinc in waste water from the production process of citric acid. (author).

UK PubMed Central (United Kingdom)

A new gadolinium chelating NIR fluorescent molecular probe increases T₁ relaxivity of water protons, facilitating combined optical and magnetic resonance imaging.

UK PubMed Central (United Kingdom)

A comparison of chlorophyll-a fluorescence in brown algae (Macrocystis integrifolia, Fucus vesiculosis), green algae (Scenedesmus obliquus, Ulva sp.)...Full Text Available

International Nuclear Information System (INIS)

A photon-induced x-ray fluorescence method allowing the simultaneous determination of iron, copper, zinc, bromine and rubidium in human blood and blood plasma samples is described. The method is reliable and has a good sensitivity for a wide range of elements. (author).

UK PubMed Central (United Kingdom)

BackgroundThe pH is an important parameter controlling many metabolic and signalling pathways in living cells. Recombinant fluorescent pH indicators (pHluorins) have come into vogue...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Cadmium sulfide particles have been synthesized in the aqueous medium using the amino acid histidine as a stabilizing agent. These particles demonstrate the phenomenon of size quantization effect. The fluorescence of histidine-stabilized CdS was found to be enhanced and quenched by the addition of DNA bases adenine and guanine, respectively. The fluorescence enhancement of CdS in the presence of adenine has been explained on the basis of interaction between the quantum dot stabilizer and the amino group of adenine. Quenching of CdS fluorescence by guanine occurs due to interaction of the substrate with the quantum dot surface.

International Nuclear Information System (INIS)

Slovak May 1981. p. 30. Czechoslovakia Sandrik, R. Kliment, V.

International Nuclear Information System (INIS)

Argon ion laser induced fluorescence measurements were carried out in a multipolar filament discharge with a broadband diode laser centered on 668 nm, which stimulated a transition from the metastable state in Ar(II) 3d4F7/2 to 4p4D05/2. The intensity of the induced fluorescence at 442 nm was maximized by the optimization of the discharge parameters and the laser power. From the recovery of the background fluorescence after the laser was turned off, the ion diffusion coefficient was deduced and compared with the result inferred from the experiments of ion acoustic wave (IAW) damping.

Energy Technology Data Exchange (ETDEWEB)

Discusses methods for determining ash content in coal using backscattering in X-ray fluorescence. The following aspects are evaluated: principle of ash content determination, energy sources, factors that influence measurement accuracy, reliability. Types of X-ray fluorescence analyzers developed in Czechoslovakia and manufactured in the Czech Republic are comparatively evaluated. Operation of the RPM 113.1 radionuclide X-ray fluorescence analyzer developed by the PAR company and used for measuring ash content in coal and coal calorific value is discussed. 7 refs.

UK PubMed Central (United Kingdom)

Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of...Full Text Available

International Nuclear Information System (INIS)

The physical foundations and methodology are described of radionuclide X-ray fluorescence analysis. The sources are listed of air, water and soil pollution, and the transfer of impurities into biological materials is described. A detailed description is presented of the sampling of air, soil and biological materials and their preparation for analysis. Greatest attention is devoted to radionuclide X-ray fluorescence analysis of the components of the environment. (ES).

Wastenet

...) Abstract: Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated strategies that have been developed for selectively labeling target molecules. More recently, two and ...

International Nuclear Information System (INIS)

Determination of Mn, Fe, Ni, Cu, Zn, and Pb in human soft tissues by radionuclide X-ray fluorescence analysis (using "2"3"8Pu and "1"0"9Cd sources) is described. The results of multielement XRS analysis of selected human tissues are tabulated. They are in good agreement with the literature data. It is concluded that X-ray fluorescence technique is a suitable method for trace element determination. (author).

British Library Electronic Table of Contents (United Kingdom)

The ultrafast dynamics of the DNA fluorescent dye Sybr Green I (SG) has been studied in buffer, single-stranded (ssDNA), double-stranded (dsDNA) and triple-stranded DNA (tsDNA). The fluorescence quantum yield of SG increases dramatically when bound to DNA (including tsDNA). The fluorescence dynamics of the free SG has shown two decay components with 0.15-0.4ps and 1.3-2.1ps time constants, depending on the fluorescence wavelength. Upon binding to DNA, the dynamics becomes slower exhibiting four decay components. This is mainly due to the restriction of the internal motions of the dye caused by the relatively rigid environment of the dye complexed with DNA.

Energy Technology Data Exchange (ETDEWEB)

Transducin {alpha} subunits are members of a large family of G-proteins and play an important role in phototransduction in rod and cone photoreceptors. We report the localization of the human cone {alpha} transducin (GNAT2) gene using fluorescence in situ hybridization (FISH) on chromosome 1 in band p13. The recent assignment of a gene for Stargardt`s disease to the same chromosomal region by linkage analysis prompted us to investigate the possible role of GNAT2 in the pathogenesis of this disease. Stargardt`s disease is characterized by degeneration in late childhood or early adulthood of the macula of the retina, a region rich in cones. We screened patients with Stargardt`s disease, with or without peripheral cone involvement as monitored by the full-field ERG, for mutations in this gene. We investigated 66 unrelated patients including 22 with peripheral cone dysfunction for mutations in the coding region of the GNAT2 gene using polymerase chain reaction-single ...

Energy Technology Data Exchange (ETDEWEB)

A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and ...

ScienceCinema

...english ...

International Nuclear Information System (INIS)

The principle is described of X-ray fluorescence analysis and the manner of detecting the emitted characteristic radiation. The advantages are presented of radionuclide X-ray fluorescence analysis which consist primarily in the possibility of conducting a totally non-destructive analysis, and of accurate and relatively narrow localization of the analyzed area, the simultaneous qualitative and quantitative determinations of a large number of elements in the order of concentrations 10"1 to 10"-"4%, stability of excitation radiation flux, simple design and relatively low capital costs. The so-called matrix effect is pointed to. A number of examples is given of the use of the cited method, including its use in the analysis of art objects. (J.B.).

Science.gov (United States)

... The constancy of the X-ray intensity ratio for each element in Table 8 as the X-ray tube settings were changed shows the excellent compensating ...

UK PubMed Central (United Kingdom)

The in vivo photochemical activity of photosystem II was inferred from modulated chlorophyll fluorescence and photoacoustic measurements in intact leaves of several plant species (Lycopersicon...Full Text Available

International Nuclear Information System (INIS)

English 2004 p. 766 Germany Krasnopyorova, AP Lebedeva, LT Yukhno, GD

International Nuclear Information System (INIS)

The model compounds, 8-methoxypsoralen-CH_2O(CH_2)_n-adenine (MOPCH_2OC_nAd, n=2,3,5,6,8, and 10) in which 5 position of 8-methoxypsoralen (8-MOP) is linked by various lengths of polymethylene bridge to N"9 of adenine. UV absorption spectra are identical with the sum of MOPCH_2OC3 and adenine absorption spectra. Solvent effect on the UV absorption and fluorescence emission spectra indicate that the lowest excited singlet state is the (#pi##->##pi#"*) state. The spectral characteristics of the fluorescence of MOPCH_2OC_nAd are strongly dependent upon the nature of the solvents. The fluorescence emission spectra in aprotic solvents are broad and structrueless due to the excimer formation through the folded conformation accelerated by hydrophobic #pi#-#pi# stacking interaction. Increasing polarity of the protic solvents leads to higher population of unfolded conformation stabilized through favorable solvation and H-bonding, ...

Science.gov (United States)

by the radionuclide X-ray fluorescence analysis into several groups according to the atomic number of the determined element. Table I documents this. ...

International Nuclear Information System (INIS)

English 1 Jul 1997 [vp.] United States McLaughlin, KW Yenen, O. Samson,

International Nuclear Information System (INIS)

German May 1981. p. 17-18. Germany Kramar, U. Puchelt, H. Karlsruhe

Science.gov (United States)

... r2 = 0.9) in the data was a power model where the number of filters was equal to ... ...

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Large-scale problems such as nuclear waste disposal are increasingly recognized to be interconnected to small scale-mechanisms. Thus, synchrotron-based high-resolution analytical X-ray probes become important tools for exploring the micro-scale chemical reactivity of heterogeneous barrier materials used in nuclear waste repositories. In this study the layout of the micro-XAS beamline at the Swiss Light Source (SLS) will be presented. The beamline is optimized towards micro beam experiments ({approx}1 x 1 {mu}m{sup 2}) in the hard-X-ray regime (4 - {approx}22 keV) and allows to combine micro X-ray fluorescence (micro-XRF), micro X-ray absorption spectroscopy (micro- XAS), and micro X-ray diffraction (micro-XRD) investigations with radioactive samples. Furthermore, the potential of micro-XRF/XAS/XRD for acquiring spatially resolved molecular level information on the speciation and structural coordination environment of radionuclides ...

Energy Technology Data Exchange (ETDEWEB)

Theoretical x-ray transition energies, lifetimes and partial multiplet fluorescence yields are presented for all spectroscopic terms of electron configurations with a single K-shell vacancy and varying number of electrons in the L-shell and M/sub 1/-subshell for multiply-ionized silicon. 9 tables.

UK PubMed Central (United Kingdom)

Human serum albumin (HSA) has two primary binding sites for drug molecules. These sites selectively bind different dansylated amino acid compounds, which—due to their intrinsic fluorescence—have...Full Text Available

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of Cr, Fe, Cu, Zn and Ph in industrial wastewaters (from surface treatment of metals and glasses) after precipitation of determined elements by 8-hydroxyquinoline. (author).

International Nuclear Information System (INIS)

Airborne lead particulates collected on a membrane filter were determined by the nondestructive X-ray fluorescence method. The gamma/X radionuclide source "2"4"1Am/Ag and a scintillation detector with a NaI/Tl crystal were used for the excitation and detection, respectively, of L X-rays of Pb. One can say, with reference to the obtained results, that the sensitivity and accuracy of the measurement is more than adequate for monitoring the Pb level in air. (author).

International Nuclear Information System (INIS)

Determination of Mn, Fe, Cu, Zn, Hg, Pb, Br, Se, Rb, Sr and Cd in the medicinal plants by radionuclide X-ray fluorescence analysis (using "2"3"8Pu, "2"4"1Am/Ag and "1"2"5I) is described. (author). 12 refs., 2 tabs.

International Nuclear Information System (INIS)

A radiometric method was elaborated for surface density determinations of the adhesive layer of plasters by radionuclide X-ray fluorescence using the 17.47 keV bremsstrahlung of "1"4"7Pm/Mo. The bremsstrahlung line excites the 8.63 keV characteristic K#alpha# line of Zn contained in the adhesive layer of the plaster as a filling material in the form of ZnO. In homogeneous adhesive layers the Zn content is proportional to surface density. (author).

International Nuclear Information System (INIS)

The basic principles of determination of the ash content of coal by the title methods are outlined. A brief technical characteristic of the ash meters and radionuclide X-ray fluorescence analyzers manufactured by the PAR company is presented. (Z.S.). 4 figs., 7 refs.

Energy Technology Data Exchange (ETDEWEB)

The applicability of the radionuclide X-ray fluorescence analysis (RXFA) for qualitative and quantitative evaluation of environmental plant samples is discussed and examples of determination of Mn, Fe, Ni, Cu, Zn, Pb in samples of apple trees are given. The instrumentation, the standard and sample preparation are also presented.

International Nuclear Information System (INIS)

Fe and Zn were determined in various parts of maize (Zea mays) in dependence on quantity of organic substrate EKOFERT as organic fertilizer in soil, using radionuclide X-ray fluorescence analysis. The increase of quantity of organic substrate EKOFERT in soil causes a decrease of heavy metal concentrations in certain parts of the plant. (author). 4 refs., 1 tab.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with Si/Li semiconductor detector and "2"3"8Pu exciting source was used for the determination of Cu, Ni, Pb, and Zn in soil samples from various localities near the D-61 Bratislava-Trnava highway (CSFR). (author) 1 ref.; 1 tab.

International Nuclear Information System (INIS)

A survey is presented of studies dealing with radionuclide X-ray fluorescence analysis (RXFA) of impurities in the air, water, soil, sediments and biological materials, mainly blood, urine, hair, soft tissues and bones. Tabulated are lists of published works on RXFA of the air, water and biological materials. (ES).

DEFF Research Database (Denmark)

Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain ...

Energy Technology Data Exchange (ETDEWEB)

This paper proves that it is practicable to build a new power model which can work efficiently at night by using a type of fluorescence material. The utilization efficiency of photovoltaic cell is improved by prolonging the actual working hours of the cell within 24 hours. Both theoretical analysis and experiment on this model are carried out, and base on which the current-time curve (I-t curve) is depicted. It shows that the model which applies the fluorescence material to photovoltaic system is available. According to the analysis and comparison between the attenuating curve of the material and I-t curve of the power system, we can conclude that the weak illumination and the mismatch on wavelength are primary reasons for the low current. Finally, several improved measures of this power model for practical application are given, and it is expected to provide a new thought for photovoltaic study. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis for nondestructive determination of Fe, Zn, Pb, and Br in air samples collected on nitrocellulose membrane filter Synpor 4 is described. A /sup 238/Pu source for the excitation and a semiconductor Si/Li detector for the detection of characteristic and L-fluorescent radiation of the above elements were used. A correction method based upon the measurements of simple or multiple Compton scattering for compensation of varying mass per unit area values in sample deposits was theoretically proposed and experimentally tested. The results obtained both with and without the correction were compared and good agreement with those given by atomic absorption spectrometry was observed.

International Nuclear Information System (INIS)

Anthracene-bis-resorcinol is an interesting molecule as it forms a hydrogen-bonded network when guest molecules with weak polarity are included. Focused ion beam (FIB) was irradiated on a part of its amorphous film with low dose, and the film was exposed to the vapor of guest molecules. From fluorescence and AFM analyses of this film, it was found that no inclusion compound was formed in FIB irradiated area, i.e. FIB irradiation suppresses the ability to form the inclusion compounds. By utilizing this phenomenon, we succeeded in a microfabrication of relief structures consisting of inclusion compounds which has different fluorescence from its surrounding. Morphology, fluorescence, and IR absorption analyses indicated that hydroxyl or resorcin groups are damaged by ion beams, and consequently a formation of hydrogen-bonded networks, which play a role of a lattice caging guest molecules, becomes impossible.

Energy Technology Data Exchange (ETDEWEB)

Five arylethylenes with 1-naphthyl, 2-naphthyl, and phenyl groups in 1,2-positions have been studied for singlet-mediated charge-transfer interactions with several amines and paraquat dication. 1-Phenyl-2-(2-naphthyl)ethylene and 1,2-di(2-naphthyl)ethylene exhibit distinct dependence of exciplex emission maxima and lifetimes, and fluorescence quenching constants, on excitation and/or monitoring wavelengths; this is in conformity with the existence of ground-state rotamers for these systems, wtih distinguishable absorption-emission spectra and fluorescence lifetimes. The fluorescence quenching by aromatic amines and paraquat dication occurs with rate constants in the limit of diffusion control and is accompanied by the formation of radical ions in polar solvents (acetonitrile). The transient spectra and kinetics associated with the radical ions, observed by 337.1- and 355-nm laser flash photolysis, are also reported. 10 ...

International Nuclear Information System (INIS)

In the electrorefining step of the pyrochemical process, actinide ions dissolved in the LiCl-KCl eutectic salt are recovered as pure actinide metals at a cathode for a re-use as a nuclear fuel from the aspect of its nonproliferation of the nuclear fuel cycles. The lanthanide species dissolved in the LiCl-KCl eutectic salt play an important role in an effective metal purification during the electrorefining step, so it is necessary to understand the chemical and physical behaviors of lanthanides in molten salt. The in situ spectroscopic measurement system and studies according to temperature changes are essential for better understandable information. To our knowledge, the absorption studies of lanthanides at high temperatures have been reported before, but the fluorescence studies of those at high temperature are not reported yet. We will discuss here the fluorescence behaviors of lanthanides in LiCl-KCl molten salt medium according to a ...

International Nuclear Information System (INIS)

Using bremsstrahlung, the resonance fluorescence yield has been measured for the 1.836-MeV 2"+_1 level in "8"8Sr. The observed yield corresponds to a level width GAMMA = 2.94 +- 0.15 meV.

UK PubMed Central (United Kingdom)

The Arabidopsis ref2 mutant was identified in a screen for plants having altered fluorescence under UV light. Characterization of the ref2 mutants showed that they...Full Text Available

Science.gov (United States)

Radiation Measurement in Crew Compartment. DTO 805: .... spacecraft and aircraft propulsion, and hazardous waste disposal. ...... combustion reactions in a turbulent chemical kinetic flow reactor using laser induced fluorescence and ...

International Nuclear Information System (INIS)

Ring opening dynamics of diarylethene derivative (BTF6) in n-hexane are studied by femtosecond transient absorption and time resolved spontaneous fluorescence techniques. Cyclo-reversion time constant is obtained.

UK PubMed Central (United Kingdom)

The ability of bovine polymorphonuclear leukocytes (PMN) to phagocytose fluorescent beads in vitro was studied using flow cytometry. The effects of varying laboratory conditions (bead:PMN ratio, length...Full Text Available

International Nuclear Information System (INIS)

An x-ray fluorescence spectrometer was designed and fabricated which nondestructively determines the thickness of aluminum cladding at small suspected thin spots in the inner or outer surface of actinide reactor tubes. The analysis method is based on the difference in absorption of actinide L/sub #alpha#/ and L/sub #beta#/ fluorescent x-rays in passing through the cladding. Calibration plots of the logarithm of the L/sub #beta#//L/sub #alpha#/ x-ray intensity ratio versus cladding thickness are linear to at least 40 mils for U-Al, U_3O_8-Al, and PuO_2-Al substrates. Accuracy and precision of the experimentally determined cladding thickness and evaluated for both uranium and plutonium substrates. Experimental thickness data are reported for 618 quality assurance analyses on six Mark 41 PuO_2-Al target tubes. An x-ray fluorescence cladding thickness monitor operated with a computer-controlled fluoroscope holds considerable ...

International Nuclear Information System (INIS)

Lysozyme dimers produced on oxidation of lysozyme with Br_2anion radicals in aqueous solutions exhibit a fluorescence spectrum (lambdasub(max) = 400 nm) closely similar to that of bi-tyrosine. This suggests that the dimer is likely to have a tyrosine-tyrosine bond resulting from the combination of tyrosine phenoxy radicals of two lysozyme molecules. Kinetic studies on dimer formation were made by measuring time-dependent fluorescence after pulsed-electron irradiation over wide pH range. The results lead to the following conclusions. The second-order growth of the dimer fluorescence observed at pH 10.7-12.5 reflects the combination process of the lysozyme radicals, which is rate-determining in the pH range. On the other hand, the first-order growth observed at pH 6.8-10.2 is attributable to the enolization of the keto-form of the dimer. A tentative reaction scheme is proposed for the dimer formation. (author).

UK PubMed Central (United Kingdom)

In vivo two-photon imaging through the pupil of the primate eye has the potential to become a useful tool for functional imaging of the retina. Two-photon excited fluorescence images...Full Text Available

UK PubMed Central (United Kingdom)

BACKGROUND: Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A new spectrofluorimetric method was developed for the determination of trace amount of nicotinamide adenine dinucleotide phosphate (NADP). Using europium (Eu{sup 3+})-tetracycline (TC) complex as a fluorescent probe, in the buffer solution of pH 7.60. NADP can remarkably enhance the fluorescence intensity of the Eu{sup 3+}-TC complex at {lambda} = 612 nm and the enhanced fluorescence intensity of Eu{sup 3+} ion is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 4.4 x 10{sup -7} to 2.2 x 10{sup -6} mol l{sup -1} with detection limit of 6.9 x 10{sup -8} mol l{sup -1}. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the ...

UK PubMed Central (United Kingdom)

Antibodies to extractable nuclear antigens (ENA) are found in a variety of collagen vascular diseases. Determining the individual specificities of these antibodies is extremely useful in establishing...Full Text Available

International Nuclear Information System (INIS)

Tris(8-quinolinolato)aluminum(III) (Alq3) shows electronic absorption bands at 378, 360 (in a 1:1 mixed solvent of methanol and ethanol (ME) at 77 K), 334, 316, 300, 263, 255.8, and 233 nm in ethanol at room temperature. According to the polarized fluorescence excitation spectrum together with MO calculations, for instance, the 360 nm band is assigned to an LL CT transition (an intramolecular charge transfer transition between two ligands), and the 378 nm band to an LM/ML CT one (an intramolecular charge transfer transition between ligand and metal). Alq3 shows a broad fluorescence band peaking at around 478 nm in the ME matrix at 77 K. The emission spectrum measured with a phosphoroscope has two emission bands at 567 and 478 nm. The 567 nm band accompanies vibronic bands at 578 and 605 nm, being safely assigned to a phosphorescence of Alq3. The lifetimes of the 478 and 567 nm bands are both 5.4 ms. The lifetime of the 478 nm band together with ...

UK PubMed Central (United Kingdom)

The drug-binding properties of human alpha-foetoprotein (alpha FP) were investigated by a fluorescence-spectral method. Human alpha FP was shown to bind to albumin's site I marker (warfarin, phenylbutazone),...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

X-ray fluorescence (XRF) and total-reflection X-ray fluorescence (TXRF) techniques suited well for a multi-element determination of K, Ca, Mn, Fe, Cu, Zn, Rb, and Sr in some Syrian medicinal plant species. The accuracy and the precision of both techniques were verified by analyzing the Standard Reference Materials (SRM) peach-1547 and apple leaves-1515. A good agreement between the measured concentrations of the previously mentioned elements and the certified values were obtained with errors less than 10.7% for TXRF and 15.8% for XRF. The determination of Br was acceptable only by XRF with an error less than 24%. Furthermore, the XRF method showed a very good applicability for the determination of K, Ca, Mn, Fe, Cu, Zn, Rb, Sr, and Br in infusions of different Syrian medicinal plant species, namely anise (Anisum vulgare), licorice root (Glycyrrhiza glabra), and white wormwood (Artemisia herba-alba)

Energy Technology Data Exchange (ETDEWEB)

The applicability of two nuclear analytical methods: radionuclide X-ray fluorescence analysis and radiometric titrations based on precipitate formations was studied in order to determine the heptacaine hydrochloride in solutions. The applied methods were evaluated based on the obtained sensitivity values.

Science.gov (United States)

Cyteogenetic maps of sorghum chromosomes 3-7, 9, and 10 were constructed on the basis of the fluorescence in situ hybridization (FISH) of ~ ... regions of heterchromatin were delimited for all 10 sorghum chrom...

UK PubMed Central (United Kingdom)

1. Digital imaging and photometry were used in conjunction with the fluorescent Ca2+ indicator, Fura-2, to examine intracellular Ca2+ signals produced by depolarization of single adrenal chromaffin...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundGenotyping analysis using capillary DNA sequencing with fluorescently labeled primer pairs obtained by polymerase chain reaction (PCR) is widely used, but is expensive....Full Text Available

Science.gov (United States)

Severe Crohn's Disease; Anxiety

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis (XFA) was used in the determination of the contents of metal residues in dosing plates for coin minting. XFA was also used for the determination of the strontium/calcium ratio in bone samples of different animals with the aim to obtain information on the food composition of these animals. It was found that bones of different animals can be distinguished based on the Sr/Ca ratio. No significant differences in the Sr/Ca ratio were observed in human bones of individuals from different social groups. (author). 1 fig., 5 tabs., 4 refs.

Energy Technology Data Exchange (ETDEWEB)

Surface probe and laser-induced fluorescence measurements in ISX-B and EBT-S have made significant contributions to the understanding of plasma edge characteristics and plasma-surface interactions in these devices. Where comparison is possible, these techniques have led to results which are consistent with plasma diagnostics. Charge-exchange neutral sputtering and self-ion sputtering have been identified as the dominent heavy impurity release mechanisms in ISX-B and EBT-S, respectively.

International Nuclear Information System (INIS)

Total M X-ray cross sections for 12 elements in atomic range 70#<=#Z#<=#92 were measured at 5.96 keV Mn K X-ray photon energy. The average M shell fluorescence yields (anti #omega#_M) of these elements have also been observed using the presently measured cross section values and the theoretical M shell photoionisation cross section values. (orig.).

International Nuclear Information System (INIS)

The present work gives preliminary results of analysis of drug mixtures (NEPHROSAL tea bag) and its water infusion. In a sample of dried drugs the elements K, Ca, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, Pb were identified, whereas in their water infusion only Ca, Mn, Zn and Sr were found. The method applied was radionuclide X-ray fluorescence analysis using a radionuclide source "1"0"9Cd, a Si/Li semiconductor detector and a multichannel analyzer Canberra 8100. (author) 6 refs.; 3 figs.

Science.gov (United States)

We demonstrated that the intensity levels and lifetimes of two-photon autofluorescences (2PAF) in human liver tissues can be exploited to diagnose hepatocellular carcinoma (HCC). Excited by an infrared femtosecond laser, we suppressed the two-photon autofluorescences of most endogenous fluorophores and made red autofluorescences more specific to particular molecules in the cryo-sectioned human livers. Using such fluorescence contrast, we found HCC tissues have reduced levels of 2PAF and longer fluorescence lifetime.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with a Si/Li semiconductor detector and "2"3"8Pu exciting source was used in the study of Mn, Fe, Cu, Zn, and Pb content of solid emissions, raw and final materials of a brick factory. From the point of view of metal content, the working environment if the brick factory is safe for workers. (author) 2 refs.; 2 figs.; 1 tab.

Energy Technology Data Exchange (ETDEWEB)

Short communication.

Science.gov (United States)

... structure along an elevational gradient in Hawaiian honeycreepers reveals contrasting evolutionary responses to avian malaria. BMC Evolutionary Biology 8: ... ...

Science.gov (United States)

Aluminum electrolytic capacitors, with 1043 failures, are a good example. Also, categorization by size and voltage reveals such frequencies of occurrence as ...

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The effect of the #+-# 0.75 T external magnetic field on the K_#alpha#_1, K_#alpha#_2, K_#beta#_'_1 and K_#beta#_'_2 x-ray production cross sections and radiative vacancy transfer probabilities from K-shell to L2 and L3 subshells and M-shell for ferromagnetic Nd, Gd and Dy and paramagnetic Eu and Ho have been investigated, using the 59.5 keV incident photons. K-shell fluorescence yields and K x-ray intensity ratios for these elements have been determined in the external magnetic field also. The K x-rays from different targets were detected using a high-resolution Si(Li) semiconductor detector. For B = 0, the present experimental results were compared with the experimental and theoretical data in the literature. The results show that K-shell fluorescence parameters such as photoionization cross section, fluorescence yield, radiation rates, vacancy transfer probabilities and spectral linewidth can change owing to the applied ...

Energy Technology Data Exchange (ETDEWEB)

Molecular imaging represents a modern research area that allows the in vivo study of molecular biological process kinetics using appropriate probes and visualization methods. This methodology may be defined- apart from the contrast media injection - as non-abrasive. In order to reach an in vivo molecular process imaging as accurate as possible the effects of the used probes on the biological should not be too large. The contrast media as important part of the molecular imaging can significantly contribute to the understanding of molecular processes and to the development of tailored diagnostics and therapy. Since more than 15 years PTB is developing optic imaging systems that may be used for fluorescence based visualization of tissue phantoms, small animal models and the localization of tumors and their predecessors, and for the early recognition of inflammatory processes in clinical trials. Cellular changes occur during many diseases, thus the molecular imaging ...

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis (RXRFA), as a non-destructive method, relatively simple and allowing measurements to be carried out in situ, is an excellent tool in research on various objects of art. A range of artefacts have been investigated by our laboratory, in part for the purposes of history of art and in part as a basis for restoration works - medieval frescoes in some Czech castles and churches, metal sculptures and objects of applied art, paints and inks of old manuscripts, paintings. Some of these are among the most valuable monuments in the Czech cultural heritage. The contribution of the results of the tests to the investigation of their 'life story' and, in some cases, to their conservation, is not negligible. Later additions and repairs can be recognised, and materials and technologies that are close to their historic counterparts can be used in restoration work.

International Nuclear Information System (INIS)

Transmission nuclear resonance fluorescence measurements were made on targets consisting of Pb and depleted U with total areal densities near 86g/cm"2. The "2"3"8U content in the targets varied from 0% to 8.5% (atom fraction). The experiment demonstrates the capability of using transmission measurements as a non-destructive technique to identify and quantify the presence of an isotope in samples with thicknesses comparable to the average thickness of a nuclear fuel assembly. The experimental data also appear to demonstrate the process of notch refilling with a predictable intensity. Comparison of measured spectra to previous backscatter "2"3"8U measurements indicates general agreement in observed excited states. Evidence of two new "2"3"8U excited states and possibly a third state have also been observed.

British Library Electronic Table of Contents (United Kingdom)

The study aimed to determine the chemical effects on the K and L X-ray intensity ratios and the K and L X-ray production cross sections for gold compounds. The K shell fluorescence yields and L shell average yields were also investigated. The samples were excited by 59.5keV ?-rays from an 241Am annular radioactive source and 123.6keV ?-rays from a 57Co annular radioactive source. K and L X-rays emitted from samples were counted by an Ultra-LEGe detector with a resolution of 0.150keV at 5.9keV. The experimental values were compared with theoretical, the semi-empirical and other experimental values.

British Library Electronic Table of Contents (United Kingdom)

The physicochemical properties of binary lipid mixtures of diether C25,25 lipids and dipalmitoyl-L-a-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C25,25 lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50^oC, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC lipo...

British Library Electronic Table of Contents (United Kingdom)

In this Letter, we demonstrate the application of time-resolved fluorescence anisotropy measurements to detect solution state hybridization of streptavidin conjugate (CdSe)ZnS quantum dots (QD). The study was performed on samples containing 10nM QD incubated with 800nM DNA. We show that the rotational correlation time of QD-DNA constructs increases significantly upon hybridization with values of 330ns (QD-ssDNA) and 1.3ms (QD-dsDNA), corresponding to a diameter of 14nm and 23nm respectively. The present study opens a new modality for hybridization detection using quantum dots.

International Nuclear Information System (INIS)

The whole equipment consists of three separate portable parts: a detector case, a microprocessor and a graphic TV monitor. Magnetic tape memory and an x-y recorder can be connected for recording the measured spectra. The analyzer contains two built-in exchangeable excitation radionuclides. Fluorescence and scattered radiation is detected using a proportional detector. The detected pulses are analyzed by a 256-channel analyzer and the results are shown on the display. The device may be used in mining laboratories, coal and ore dressing plant control rooms or in mining fields of open cast mines for quick detection of the quality of mined or dressed raw materials. (E.S.). 1 fig.

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence analyzer consists of a source changer and a sample changer. "5"5Fe, "1"0"9Cd and "2"4"1Am are used as excitation sources. The radiation is detected with a semiconductor Si(Li) detector. The complete assembly of the apparatus consists of an imagine unit, a keyboard, a floppy disc drive, a printer, a console and a rack with analog and digital electronics. Its multichannel amplitude analyzer consists of power supplies, a high voltage supply, a linear amplifier, an analog-to-digital converter and a computer. The technical specifications are given. The control and data processing system is controlled with an MHB 8080A microprocessor. Software for semiconductor gamma spectrometry and for quantitative gamma spectrometry will be supplied with the equipment. (E.S.). 3 figs., 4 refs.

Energy Technology Data Exchange (ETDEWEB)

Genetic mapping is approached using the techniques of high resolution fluorescence in situ hybridization (FISH). This technology and the results of its application are designed to rapidly generate whole genome as tool box of expressed sequence to speed the identification of human disease genes. The results of this study are intended to dovetail with and to link the results of existing technologies for creating backbone YAC and genetic maps. In the first eight months, this approach generated 60--80% of the expressed sequence map, the remainder expected to be derived through more long-term, labor-intensive, regional chromosomal gene searches or sequencing. The laboratory has made significant progress in the set-up phase, in mapping fetal and adult brain and other cDNAs, in testing a model system for directly linking genetic and physical maps using FISH with small fragments, in setting up a database, and in establishing the validity and throughput of the system.

International Nuclear Information System (INIS)

This paper aimed to the evaluation of different kinds of sorbent material preparation and to the evaluation of their characteristics at different pH conditions by X-ray fluorescence analysis. This method is suitable for identification and determination of elements in samples of different character, state and origin because it is a polycomponent, non-destructive, fast and simple analytical method. Moreover, it allows timeadvantageous and reliable measurements. This paper studies problems concerning the determination of some selected elements (Mn, Fe, Ni, Cu, Zn, Pb) in pharmaceutical samples of sodium chloride in the solid state as well as in its solution by sorption on chelating extraction membrane 3M Empore"T"M and on the strongly acidic ion-exchanger Dowex 50Wx8. Conditions for the most effective sorption of determined elements are also interpreted. (author)

British Library Electronic Table of Contents (United Kingdom)

Abstract In 46 febrile neutropenic patients who had undergone haematopoietic stem cell transplantation, the fluorescence in situ hybridisation using peptide nucleic acid probes (PNA FISH), Gram stain/acridine orange leukocyte cytospin (Gram/AOLC), and differential time to positivity (DTP) methods were performed for detection of catheter related bloodstream infections (CRBSIs). As compared with the DTP method (which detected 11 patients with CRBSI), the PNA FISH and the Gram/AOLC methods detected ten of 11 CRBSI patients, resulting in a sensitivity, specificity, negative predictive value and positive predictive value of 91%, 100%, 97% and 100%, respectively, for the PNA FISH method as well as for the Gram/AOLC method.

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for rapid and nondestructive analysis of metallic glasses. The methods were compared for accuracy and precision with the atomic absorption method. Some results of the analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width as well as the length and a qualitative analysis of the composition of material surfaces are considered. (author).

International Nuclear Information System (INIS)

It is shown that it is necessary to take into account locality of the analysis and to introduce additional corrections for partial capture of matrix and fluorescent subexcitation by matrix during quantitative X-ray spectral microanalysis of finely dispersed materials. Cast two-phase (#alpha#+#beta#) titanium alloy VT3-1 is chosen as an investigation object.

UK PubMed Central (United Kingdom)

When high-purity copper (≥99.98%_wt) is melted, held in its liquid state for a few hours with iterative thermal cycling, then allowed to resolidify, the ingot surface is found to have...Full Text Available

International Nuclear Information System (INIS)

The standard deviation of measurement results of a given element in XRF spectrometry depends on three factors: concentration and concentration region, atomic number and matrix. The effects of these factors were investigated by an XRF instrument type ARL 72.000 for aluminium metal, bauxite-red mud and aluminium using computerized data processing. A comparison of linear and nonlinear relation between concentration and the result of XRF analysis was made for the determination of standard deviation. (R.P.).

International Nuclear Information System (INIS)

The water soluble, photolabile nitrene precursor, azidonaphthalene-2,7-disulfonic acid (ANDS) was encapsulated in small unilamellar, isoelectric (egg PC) or negatively charged (egg PC + dihexadecylphosphate) liposomes. The individual and combined effects of heme-proteins and UV irradiation on the fluorescence of these vesicles under aerobic conditions were studied. Consistent with the catalytic action of heme-proteins on lipid peroxidation and peroxide decomposition, addition of cytochrome c (positively charged) or catalase (negatively charged) to the vesicles elicited immediate formation of a fluorescence band at 470 nm, characteristic of Schiff bases that form from aldehyde byproducts of decomposing hydroperoxides. Ultraviolet irradiation of liposomes caused no significant changes in the fluorescence spectrum, in spite of the radiolysis of ANDS inside the vesicles with consequent formation of nitrene radicals. When ...

Energy Technology Data Exchange (ETDEWEB)

The authors identify a need for a device which can remotely measure methane in coal mines. Similar techniques which have been used to measure atmospheric pollutants are discussed. These techniques include adsorption, Raman scattering and fluorescence. While differential adsorption and Raman scattering techniques have potential there are a number of problems to be resolved before they could be applied effectively. It is felt that an area which may provide suitable technology sometime in the future is in the field of laser sources. 6 refs., 4 tabs.

International Nuclear Information System (INIS)

This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).

UK PubMed Central (United Kingdom)

Anti-TAG-72 monoclonal antibodies target the tumor-associated glycoprotein (TAG)-72 in various solid tumors. This study evaluated the use of anti-TAG-72 monoclonal antibodies, both murine CC49...Full Text Available

International Nuclear Information System (INIS)

Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the target to measure the K shell fluorescence parameters such as ...

Energy Technology Data Exchange (ETDEWEB)

Elements Ti, Mn, Fe, Ni, Cu, Zn, Pb, Br, Rb and Sr were determined by the method of radionuclide X-ray fluorescence analysis with semiconductor detection in samples of Taraxacum officinale from various localities of Bratislava. The dependence of their content on the source and the degree of the air pollution was found out.

Energy Technology Data Exchange (ETDEWEB)

Fe, Mn, Ni, V, Ti and Mo were determined in aerosols from manual arc welding. Samples of welding aerosols were trapped on a Synpor 4 filter. The amount of determined elements in aerosols was detected using the method of radionuclide X-ray fluorescence analysis. A /sup 241/Am annular source was used as the source of excitation radiation and radiation was processed using a Si(Li) spectrometer.

UK PubMed Central (United Kingdom)

AbstractWe describe the fusion of enhanced green fluorescent protein to the C-terminus of the HsdS DNA sequence-specificity subunit of the Type I DNA modification methyltransferase M.EcoKI....Full Text Available

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of Sr/Ca ratio in bones to test the influence of a diet on this ratio. Significant differences were observed for Sr/Ca ratio in bones of various animals. Only small differences in the Ca/Sr ratio were observed for the samples of various prehistoric human bones. (author) 4 refs.; 4 tabs.

Energy Technology Data Exchange (ETDEWEB)

Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed.

Energy Technology Data Exchange (ETDEWEB)

Trace elements have been determined in biological samples including pepperwort, thyme, plantain, blessed thistle and common comfrey as well as cabbage leaves and milk powder. Concentrations of Al, Si, and Cl have been determined by fast neutron activation analysis while, in the case of Mg-, K, and Cl the X-ray fluorescence method was used.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

An energy sensitive Si(Li) detector XRF analyzer built by ATOMKI, Hungary, has been applied for various analytical purposes in alumina production at the Almasfuezitoe Alumina Company, Hungary. Specifically, the CaO content in red mud was determined by the new XRF technique using isotope excitation sources. The analysis of other components is under way. (R.P.).

UK PubMed Central (United Kingdom)

The nature of binding of Ru(phen) 2+ (I), Ru(bipy) 2+ (II), Ru(terpy) 2+ (III) (phen = 1,10-phenanthroline, bipy 3 = 2,2'-bipyridyl, 3 terpy = 2,2'2," - 2 terpyridyl) to DNA, poly[d(G-C)] and poly[d(A-T)]...Full Text Available

International Nuclear Information System (INIS)

The first step in the protection of the environment is the control of pollutant level in the components of the environment. The application is compared of radionuclide X-ray fluorescence analysis (RXFA) used for this purpose with polarographic and nuclear analytical techniques. The advantage of RXFA is its high sensitivity and selectivity, its low time and cost exactingness. The origins and development of RXFA are described. (Ha).

UK PubMed Central (United Kingdom)

BackgroundLate-onset sepsis in the premature infant is frequently revealed by severe, unusual and recurrent bradycardias. In view of the high morbidity and mortality...Full Text Available

Science.gov (United States)

... herbaceous and low succulents (mostly Sesuvium portulacastrum, also Ipomea sp., Euphorbia sp.). Local informants revealed that historic colonies ... vegetation (Sesuvium portulacastrum, Suriana maritima, ...

Science.gov (United States)

Evolution in Space Radio Telescopes Reveal Youngest Stellar Corpse Gas Clouds in Whirlpool Galaxy Yield Important Clues Supporting Theory on Spiral Arms Starbust-driven Winds...

UK PubMed Central (United Kingdom)

The rapidly emerging science of epigenetics and epigenomic medicine promises to reveal novel insights into the susceptibility to and the onset and progression of epileptic disorders. Epigenetic...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Radionuclide X-ray fluorescence analysis is a method, which has many advantages for analysing various historic artefacts, as it is relatively cheap, sensitive and non-destructive, and it allows measurements in-situ. However, this analysis has also certain limitations especially concerning sensitivity to chemical elements only, irrespective of the compounds or chemical forms in which these elements have been bonded. In addition, light elements emitting very soft X-rays cannot be measured, and in order to detect a wide range of elements, it is necessary to carry out repeated measurements with different radiation sources. Despite these limitations, valuable information can be obtained about the composition of historic materials and data about the origin and age of these artefacts can be derived. Analyses of wall paintings, ancient metal sculptures or other objects of art provide the basis for historic considerations documented in our results for some objects belonging ...

British Library Electronic Table of Contents (United Kingdom)

We present a forward modelling technique for calculating the surface X-ray spectra for a variety of lunar terrains. Our calculations considered variations in solar fluxes from solar quiescent condition to large flare activity (M1 flare), and expected elemental concentrations in the target, as well as yield, instrumental, and viewing geometry parameters for X-ray induced fluorescence from the lunar surface. Additionally, we present estimates of anticipated XRF signals from prominent Ka lines observable by a collimated 14cm2 X-ray detector from a 100km lunar orbit with 20km spatial resolution. Our results show that Mg, Al and Si characteristic Ka lines can be observed for all solar conditions. The Ca Ka lines line can be differentiated from a fixed background during more energetic solar cond...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis and fast neutron activation analysis were used for the determination of chromium. The excitation source for X-ray fluorescence analysis was a ring-shaped "2"4"1Am source with an activity of 18.5x10"9 Bq. SYNPOR filters of 35 mm in diameter were used for the measurement. The 5.414 keV Cr peak was measured with a Si(Li) detector. The sensitivity was 0.05 mg for a period of measurement of 1000 s. A neutron generator with an emission of 10"9 s"-"1 was used as the source of fast neutrons. "5"2V and "5"3V, the products of nuclear reaction with Cr, were measured gamma spectrometrically with a Ge(Li) detector. The sensitivity for Cr is 0.015 mg, in the presence of Mn which causes interference the sensitivity is a mere 0.075 mg. The mentioned methods were used to determine total Cr and Cr(VI) in welding aerosols. It was found that the most toxic form, i.e., Cr(VI), is released during manual arc welding of high ...

International Nuclear Information System (INIS)

A 'Laboratory of Quantitative Methods in Monument Research' is being built at the CTU Prague. Its primary orientation is the investigation of historic architecture, although other objects of art can also be investigated. In the first phase, two radiation methods are being established, but it is set up in such a way, that various other methods can readily be added in its future development. The radiation methods chosen for the initial development of the laboratory are: thermoluminescence dating and X-ray fluorescence analysis. The design of the automated TL-reader, built in our laboratories, is adjusted for the purpose of dating of historic brick architecture (which, of course, does not exclude applications for ceramics and other materials). The investigation of renaissance architecture in southern Bohemia and Moravia is under preparation as the first large campaign of this kind in the Czech Republic. Radionuclide X-ray fluorescence analysis has ...

Energy Technology Data Exchange (ETDEWEB)

The fluorescent behaviour and the photodynamic effect was studied in native and structurally modified lysozyme and ..cap alpha..-lactalbumin. The Tyr residues in lysozyme and ..cap alpha..-lactalbumin show different sensitivities to the photodynamic effect. The effect is zero in the case of Tyr from native lysozyme. In contrast, the Tyr residues in ..cap alpha..-lactalbumin are susceptible to photooxidation, which indicates a greater degree of exposure to the solvent. The three His residues of ..cap alpha..-lactalbumin have different degrees of exposure and show two different kinetics of photooxidation whereas the His residue of lysozyme is photooxidized with a single kinetic. Two photooxidation kinetics were obtained for the Trp residues of both native proteins, an indication that in both cases there are Trp residues that are differently exposed to the solvent. The wavelengths of maximum fluorescent emission of the Trp residues were different ...

International Nuclear Information System (INIS)

The design of a gaging head for a portable radionuclide X-ray fluorescence analyzer is described. The gaging head is designed as a construction unit system which enables the application of lateral reflexion geometry as well as of coaxial geometry. It is designed so that adjustment from one geometry to the other is labour and time saving. The selection of characteristic radiation is performed by a couple of Ross' differential filters. These filters are prepared by a novel technique developed by our laboratory. The filter exchange is effected by the longitudinal move of the couple of filters encapsulated in a holder. The shift of the filters is controlled by means of a triggering mechanism situated in the body of the gaging head handle. This design makes is possible to handle the gaging head during measurements with one hand. A simple interchange of the absorption filter for the transmissive filter allows the operator to avoid any unwanted shift of the head during ...

International Nuclear Information System (INIS)

Reaction of formation of 3, 5, 7, 3', 4', 5' - hexaoxiflavone - myricetin complexes with zirconium and hafnium ions has been the basis for development of luminescent method of determining these elements. Optimum conditions for complexing have been determined. For Hf they are : 8-9 HCl concentration, maximum fluorescence wave length (lambda fl.)of 520 nm, wave length of exciting light (lambda el) of 436 nm, for Zr lambda fl = 536nm, lambda el = 436 nm. Stable fluorescence establishes after 25 min. for Zr and after 15 min for Hf in the presence of 40% ethanol. Usage of various camouflage agents has permitted to attain high selectivity of the method. Possibility for determination of Zr with myricetin in the presence of a 10-time excess of Hf, Cr, Cu, 50-time excess of Mo and Ti is shown. Sensitivity of Zr determination is 2.0x10 #mu#g"-"2/ml, for Hf it is 9.0x10 #mu#g"-"3 and mineral waters.

Energy Technology Data Exchange (ETDEWEB)

A highly efficiency partial smoothing method is proposed to be used for inverters for 40W class household fluorescent inverters. In this system, the input current from the commercial AC power source is accumulated in a capacitor with comparatively small capacity as the electric charge, and then the lamp circuit is driven by the inverter utilizing the charging voltage of the capacitor and the charging voltage of the separately prepared partial smoothing capacitor. By this method, the RF harmonic components in the supply current can be decreased to improve the power factor with no complicated feedback controlling device. In addition, comparatively small capacity coils and capacitors can be used. The structure of the circuit and the operation of this proposed method are described, and the operational characteristic of the prototype circuit and the result of analysis are shown. Furthermore, problems and improving method of the actual circuit are investigated by an ...

International Nuclear Information System (INIS)

The determination of small amounts of elements by radionuclide X-ray fluorescence analysis is described. Samples containing 5x10"-"4 to 5x10"-"6 g of elements were fixed on a suitable carrier. For a coaxial configuration a low-energy source of the #gamma#/X type was used, namely an annular "2"4"1Am/Ag source with an activity of 7.4x10"8 s"-"1 (20 mCi), and for a configuration with side reflection source of the #beta#/X type was used, namely "1"4"7Pm/Sm with the activity of Pm(OH)_3 approximately 3.7x1O"1"0 s"-"1 (1 Ci). Cs, Ba, La, Pr, Nd, and Ag were determined by means of the Ksub(#alpha#) line and Hg, W, Er, and Pr by means of the Lsub(#alpha#) line. For all elements studied a detection limit of the order of 10"-"7 g was achieved. (author).

International Nuclear Information System (INIS)

Atomic oxygen is measured in a pulsed dielectric barrier discharge (DBD) using two-photon absorption laser-induced fluorescence (TALIF). The ground-level atomic oxygen is excited to the 3p "3P state by two-photon absorption at 226 nm. Negative (-40 kV) or positive (+30 kV) pulsed DBD occurs in an O_2-N_2 mixture at atmospheric pressure. The pulse width of the DBD current is approximately 50 ns. The TALIF experiment shows that the decay rate of atomic oxygen increases linearly with O_2 concentration. This result proves that atomic oxygen decays mainly by the third-body reaction, O + O_2 + M #-># O_3 + M. The rate coefficient of the third-body reaction is estimated to be 2.2 x 10"-"3"4 cm"6 s"-"1 in the negative DBD and 0.89 x 10"-"3"4 cm"6 s"-"1 in the positive DBD. It is shown that the decay rate of atomic oxygen increases linearly with humidity. This can explain the well-known fact that ozone production in DBD is suppressed by increasing humidity.

International Nuclear Information System (INIS)

The purpose of this work is to present a comprehensive, instructive analysis of the basis of radionuclide XRFA, to describe methods of sample preparation for environmental analysis and to make the reader more familiar with the procedures, methods and instrumentation of radionuclide XRFA used in this field. This book discusses the use of radionuclide XRFA for solving analytical problems of the environment and information is presented concerning the current state of research and use of radionuclide XRFA in this significant area. The present volume will serve as a basic source of data and also as a laboratory handbook. refs.; figs.; tabs.

British Library Electronic Table of Contents (United Kingdom)

We have prepared a series of novel gemini surfactants having ester bonds in their structures. These surfactants possess two identical hydrophilic polyethylene glycol moieties, two hydrophobic alkyl group moieties, and an anionic spacer. The structures of these compounds were confirmed through infrared and nuclear magnetic resonance spectroscopic and elemental analyses. The novel gemini surfactants exhibit excellent surface activity in terms of their surface tension, low-foaming, wetting power, and fluorescence properties. The presence of the ester linkages made these structures cleavable surfactants.

British Library Electronic Table of Contents (United Kingdom)

A new coumarin-based sensor molecule (L1) has been synthesized and this was found to bind calcium and magnesium ions more effectively as compared to other alkali/alkaline earth/lanthanide and certain transition metal ions. A significant enhancement in fluorescence intensity was observed on binding to Ca2+ and Mg2+ ions; while a minor quenching was observed for weakly bound Hg2+, Ni2+, Fe3+, and Co2+ ions. PET process, coupled with the ICT process, is proposed to explain the observed spectral response.

International Nuclear Information System (INIS)

Radionuclide x-ray fluorescence analysis was used for the determination of Fe, Zn, Br and Rb levels in whole blood from dilated cardiomyopathy patients and from a control group. The XRF-system consisted of a radionuclide source "1"0"9Cd, a semiconductor Si/Li detector connected to a multichannel analyzer. Fe content in blood of patients was significantly lower than that of the control. Zn content showed no deviation from normal range. Values for Br and Rb in patients highly exceed the range reported for them. (author) 4 tabs.; 9 refs.

Energy Technology Data Exchange (ETDEWEB)

Flow cytogenetics is a rapidly developing technology which complements rather than supplants the traditional methods of cytogenetic analysis. As an adjunctive approach to chromosome classification, flow systems measurements of isolated chromosomes give new information relative to the enrichment of A-T or G-C base sequences on specific chromosomes. As a result, chromosomal fluorescence polymorphisms both within and among individuals that are not always associated with banding polymorphisms can be detected. Finally, flow sorting provides bulk quantities of highly purified chromosomes for use in biochemical studies. Methodology is detailed. (PSB)

International Nuclear Information System (INIS)

The elemental analysis of some plant samples have been carried out in Trabzon region (Turkey) using energy-dispersive X-ray fluorescence (EDXRF) spectrometry. We have analyzed plant samples for nine stations using 1.85 GBq 55Fe radioactive sources. We have found that potassium and calcium within 0.3-1.4% and 0.3-2.8% were present in concentration in plants for every station, respectively. The concentration of Cl and Ti generally changed according to the plant species and the sampling station.

Science.gov (United States)

In November 1977, 627 soldiers belonging primarily to the First Battalion, 82nd Airborne Division, stationed at Fort Bragg, were sent to the Canal Zone, Panama, for jungle warfare training. A medical surveillance program incorporating pre- and post-evaluations over a 6-month period with dermatologic examinations, questionnaires, and serologic tests was established. Ten cases of cutaneous leishmaniasis (1.6/100 men) were diagnosed by positive Leishmania culture. The demonstrated lack of sensitivity and specificity of the indirect fluorescent antibody test and the direct agglutination test render these serological methods useless as diagnostic screening methods in the early stages of this disease. PMID:7406101

Energy Technology Data Exchange (ETDEWEB)

Human BTEB cDNA clones have been isolated, sequenced, and the corresponding gene has been assigned to human chromosome 9, region q13, by fluorescent in situ hybridization and DNA blot analysis using DNAs from hybrid cell clones containing a single human chromosome. The cDNA clone encodes a polypeptide of 244 amino acids whose sequence shows a high sequence similarity with the rat BTEB (98% amino acid identity).

International Nuclear Information System (INIS)

The use of the method is described on powder samples before and after sintering with an La content of up to 1%. For excitation of the K series of La a _2_4_1Am source with an activity of 1.11 GBq was used. The obtained results showed that the method is sufficiently accurate (error 7%) at a short period of measurement (100 s). It gives satisfactory results even in the comparison of the experimental relative count rate and the theoretically calculated value despite the fact that the analytical signal comes from the sample surface. (Ha).

CERN Document Server

CH Cygni is a symbiotic star consisting of an M giant and an accreting white dwarf, which is known to be a highly variable X-ray source with a complex, two-component, spectra. Here we report on two Suzaku observations of CH Cyg, taken in 2006 January and May, during which the system was seen to be in a soft X-ray bright, hard X-ray faint state. Based on the extraordinary strength of the 6.4 keV fluorescent Fe K-alpha line, we show that the hard X-rays observed with Suzaku are dominated by scattering.

International Nuclear Information System (INIS)

Examples are given of reference materials for radionuclide X-ray fluorescence analysis (RXFA) of the environment processed by the National Bureau of Standards and the IAEA. Methods are described used for preparing standard materials for RXFA. For determining air pollutants the sample is prepared by dry or wet mineralization. Water samples have to be preserved prior to analysis. Insoluble components are separated by filtration or centrifugation. Biological materials must be dehydrated and homogenized. Samples of soil, sludges, sediments and solid wastes will sometimes have to be converted into a solution in some cases a leachate will have to be obtained. (ES).

International Nuclear Information System (INIS)

A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step quantitative stripping with dilute neutral sodium pyrophosphate, which also acts as ...

International Nuclear Information System (INIS)

M-shell x-ray production cross sections for selected heavy elements, namely, _7_2Hf, _7_3Ta, _7_4W, _7_5Re, _7_6Os, _7_7Ir, _7_8Pt, _7_9Au, _8_3Bi, and _9_0Th, were measured for protons of energy 0.6--4.0 MeV. The experimental results are compared with the predictions of the first Born and semiclassical approximations for M-shell ionization; these data are also compared with the theory that accounts for the projectile's energy loss and Coulomb deflection as well as for the target's M-shell electron perturbed stationary state and relativistic nature (ECPSSR). Generally, fair agreement between the data and the ECPSSR theory is found. Some systematical discrepancies observed for the lightest elements (Hf, Ta, and W) are explained as possible ambiguities in the M-shell Coster-Kronig factors and fluorescence yields, which were used to convert theoretical M-subshell ionization cross sections to the total M-x-ray production cross sections. The experimental total M-shell ...

International Nuclear Information System (INIS)

A simple and specific method has been developed for the simultaneous determination of the four major Cinchona alkaloids and their dihydroderivatives and pyridoxine hydrochloride (Vitamin B_6) by high-performance liquid chromatography (HPLC) with fluorescence detection (#lambda#_e_m=420 nm with #lambda#_e_x=330 nm). The chromatographic separation was performed on a Phenomenex Prodigy ODS column (5 #mu#m, 250 mmx3.2 mm i.d.), recommended for basic compounds, under isocratic reversed-phase conditions. The method allowed a good peak shape and an effective resolution of the tested compounds. The extraction of alkaloids from the Cinchona succirubra bark was carried out in mild and fast conditions (ambient temperature, 20 min) by ultrasonication. The procedure showed to be advantageous respect to a reference method, which involved Soxhlet extraction. The results were compared statistically by means of the Student's t-test and the variance ratio F-test; no significant ...

UK PubMed Central (United Kingdom)

Auditory neurons in the superior colliculus (SC) respond preferentially to sounds from restricted directions to form a map of auditory space. The development of this representation is shaped...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Research reported here reveals that the reduction of CO{sub 2} emissions into the atmosphere, is mainly dependent on the decrease of the use of fossil fuels, but also on the development of environment-friendly technology and greening of the environment. 2 refs.

UK PubMed Central (United Kingdom)

The bovine syncytial virus, a member of the retroviral subfamily Spumavirinae, causes a persistent, asymptomatic infection in cattle. Nucleotide sequence analysis of the viral genome revealed two overlapping...Full Text Available

UK PubMed Central (United Kingdom)

Assessments of drinking water safety rely on the assumption that ingestion represents the principal route of exposure. A review of the experimental literature revealed that skin penetration rates for...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundHigh complexity is considered a hallmark of living systems. Here we investigate the complexity of temporal gene expression patterns using the concept of Permutation Entropy...Full Text Available

UK PubMed Central (United Kingdom)

How does complex social behavior evolve? What are the developmental building blocks of division of labor and specialization, the hallmarks of insect societies? Studies have revealed the developmental...Full Text Available

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Previous studies have revealed marked differences in the incidence of leukemia between rats and mice exposed to 1,3-butadiene that do not appear to be readily explained on the basis of pharmacokinetics...Full Text Available

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SUMMARYThe cytolytic activity of natural killer (NK) cells is regulated by inhibitory receptors that detect the absence of self molecules on target cells. Structural studies of...Full Text Available

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Background: In North America and Europe, 80% of invasive skin cancers are basal cell carcinoma while 20% are squamous cell carcinoma (SCC). In contrast, African studies reveal a preponderance...Full Text Available

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Early on, intriguing biological activities were found associated with the EETs using in vitro systems. Although the EETs other than the 5,6-isomer, are quite stable chemically,...Full Text Available

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The specific white matter location of all the spinal pathways conveying penile input to the rostral medulla is not known. Our previous studies using rats demonstrated the loss of low but not high threshold...Full Text Available

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The anatomy of the labyrinth and the structure of the macula utriculi of the teleost fish (burbot) Lota vulgaris was studied by dissection, phase contrast, and electron microscopy....Full Text Available

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A recent EPA-sponsored study of sediment and seafood contamination in Quincy Bay revealed elevated levels of several complex organic pollutants frequently of concern in human health assessments. A seafood...Full Text Available

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BackgroundSynonymous sites are freer to vary because of redundancy in genetic code. Messenger RNA secondary structure restricts this freedom, as revealed by previous findings in...Full Text Available

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We have established a cartilaginous fish cell line [Squalus acanthias embryo cell line (SAE)], a mesenchymal stem cell line derived from the embryo of an elasmobranch, the spiny dogfish...Full Text Available

UK PubMed Central (United Kingdom)

Earlier studies of white London busmen revealed that the ischaemic heart disease experience of conductors is better than that of drivers. Various factors which might be related to this difference have...Full Text Available

UK PubMed Central (United Kingdom)

Electrophoretic analysis of protein variation at the coagulation F13B locus has previously revealed three alleles, with alleles 1, 2, and 3 each being at high frequency in European,...Full Text Available

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Vulnerability to abused drugs is influenced by multiple genes unique to each drug as well as to risk genes for polydrug abuse. If several inbred mouse strains respond to different drugs similarly,...Full Text Available

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Sibling Paenibacillus dendritiformis bacterial colonies grown on low-nutrient agar medium mutually inhibit growth through secretion of a lethal factor. Analysis of secretions reveals...Full Text Available

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Hematopoiesis is the cumulative result of intricately regulated signaling pathways that are mediated by cytokines and their receptors. Studies conducted over the past 10 to 15 years have revealed that...Full Text Available

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Marine sediments are frequently covered by mats of the filamentous Beggiatoa and other large nitrate-storing bacteria that oxidize hydrogen sulfide using either oxygen or nitrate, which...Full Text Available

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BackgroundThe Gram-negative bacterium Burkholderia pseudomallei (Bp) is the causative agent of the human disease melioidosis. To understand the evolutionary mechanisms...Full Text Available

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Bovine embryos can be generated by in vitro fertilization or somatic nuclear transfer; however, these differ from their in vivo counterparts in many aspects and exhibit a higher proportion of developmental...Full Text Available

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The role of pheromone biosynthesis activating neuropeptide (PBAN) in the regulation of pheromone biosynthesis of several female moth species is well elucidated, but its role in the males has been a...Full Text Available

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BackgroundNew technology allows more precise definition of structural alterations of all retinal layers although it has not been used previously in cases of optic...Full Text Available

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Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics...Full Text Available

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BackgroundThe transcription factor Pax6 is essential for the development of the central nervous system and it exerts its multiple functions by regulating the expression of downstream...Full Text Available

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BACKGROUND AND AIMS:In view of increasing therapeutic efficacy, the delivery of hepatitis C virus (HCV) antiviral treatment is expected to increase. Yet practical experience reveals...Full Text Available

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MicroRNAs (miRNAs) have been implicated to play key roles in normal physiological functions, and altered expression of specific miRNAs has been associated with a number of diseases. It is of great interest...Full Text Available

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BackgroundStructured noncoding RNAs perform many functions that are essential for protein synthesis, RNA processing, and gene regulation. Structured RNAs can be detected by comparative...Full Text Available

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This study examined the genetic basis of hypertension and renal disease in Dahl SS/Mcwi (Dahl Salt-Sensitive) rats using a complete chromosome substitution panel of consomic rats in which each of the...Full Text Available

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DYF-13, originally identified in C. elegans within a collection of dye-filling chemosensory mutants, is one of several proteins that have been classified as putatively involved...Full Text Available

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We used tryptophan auxotrophs of the dicot Arabidopsis thaliana (wall cress) to determine whether tryptophan has the capacity to serve as a precursor to the auxin, indole-3-acetic acid (IAA). Quantitative...Full Text Available

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During formation of the optic projection in astray/robo2 mutant zebrafish, optic axons exhibit rostro-caudal pathfinding errors, ectopic midline crossing and...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A correlation investigation was carried out on the series of atomic coordinates (MPV) and temperature factor (T {sub f}), respectively for human hemoglobin and HIV-1 protease protein main chains. The MPV series revealed resemblances to the corresponding T {sub f} series. Each minor or major peak in a series had a corresponding peak in the related series. This brings a qualitative evidence for the connection of the two parameters. The series were further subjected to spectral and detrended fluctuation analysis which all revealed long-range correlation properties. This combined analysis revealed that the data were controlled both by the correlation of stationary fluctuation and trends or non-stationary contribution to correlation. The correlation of all MPV series was found to be much less sensitive to ligand binding than the corresponding T {sub f} series. Thus the long-range correlation properties of the protein main chain ...