Fan-less long range alpha detector

DOEpatents

MacArthur, D.W.; Bounds, J.A.

1994-05-10

A fan-less long range alpha detector is disclosed which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces. 2 figures.

Fan-less long range alpha detector

DOEpatents

MacArthur, Duncan W.; Bounds, John A.

1994-01-01

A fan-less long range alpha detector which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces.

Age-related alterations in the fractal scaling of cardiac interbeat interval dynamics

NASA Technical Reports Server (NTRS)

Iyengar, N.; Peng, C. K.; Morin, R.; Goldberger, A. L.; Lipsitz, L. A.

1996-01-01

We postulated that aging is associated with disruption in the fractallike long-range correlations that characterize healthy sinus rhythm cardiac interval dynamics. Ten young (21-34 yr) and 10 elderly (68-81 yr) rigorously screened healthy subjects underwent 120 min of continuous supine resting electrocardiographic recording. We analyzed the interbeat interval time series using standard time and frequency domain statistics and using a fractal measure, detrended fluctuation analysis, to quantify long-range correlation properties. In healthy young subjects, interbeat intervals demonstrated fractal scaling, with scaling exponents (alpha) from the fluctuation analysis close to a value of 1.0. In the group of healthy elderly subjects, the interbeat interval time series had two scaling regions. Over the short range, interbeat interval fluctuations resembled a random walk process (Brownian noise, alpha = 1.5), whereas over the longer range they resembled white noise (alpha = 0.5). Short (alpha s)- and long-range (alpha 1) scaling exponents were significantly different in the elderly subjects compared with young (alpha s = 1.12 +/- 0.19 vs. 0.90 +/- 0.14, respectively, P = 0.009; alpha 1 = 0.75 +/- 0.17 vs. 0.99 +/- 0.10, respectively, P = 0.002). The crossover behavior from one scaling region to another could be modeled as a first-order autoregressive process, which closely fit the data from four elderly subjects. This implies that a single characteristic time scale may be dominating heartbeat control in these subjects. The age-related loss of fractal organization in heartbeat dynamics may reflect the degradation of integrated physiological regulatory systems and may impair an individual's ability to adapt to stress.

Alpha-ray detection with a MgB 2 transition edge sensor

NASA Astrophysics Data System (ADS)

Okayasu, S.; Katagiri, M.; Hojou, K.; Morii, Y.; Miki, S.; Shimakage, H.; Wang, Z.; Ishida, T.

2008-09-01

We have been investigating for neutron detection with the MgB 2 transition edge sensor (TES). For the purpose, we have been developing a low noise measurement system for the detection. To confirm the performance of the detecting sensor, alpha ray detection from an americium-241 ( 241Am) alpha-ray source was achieved. A short microfabricated sample with 10 μm length and 1 μm width is used to improve the S/N ratio. The detection is achieved under a constant current condition in the range between 1 and 6 μA bias current, and the resistivity changes at the sample due to the alpha ray irradiation is detected just on the transition edge.

Temperature dependence of alpha-induced scintillation in the 1,1,4,4-tetraphenyl-1,3-butadiene wavelength shifter

NASA Astrophysics Data System (ADS)

Veloce, L. M.; Kuźniak, M.; Di Stefano, P. C. F.; Noble, A. J.; Boulay, M. G.; Nadeau, P.; Pollmann, T.; Clark, M.; Piquemal, M.; Schreiner, K.

2016-06-01

Liquid noble based particle detectors often use the organic wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) which shifts UV scintillation light to the visible regime, facilitating its detection, but which also can scintillate on its own. Dark matter searches based on this type of detector commonly rely on pulse-shape discrimination (PSD) for background mitigation. Alpha-induced scintillation therefore represents a possible background source in dark matter searches. The timing characteristics of this scintillation determine whether this background can be mitigated through PSD. We have therefore characterized the pulse shape and light yield of alpha induced TPB scintillation at temperatures ranging from 300 K down to 4 K, with special attention given to liquid noble gas temperatures. We find that the pulse shapes and light yield depend strongly on temperature. In addition, the significant contribution of long time constants above ~50 K provides an avenue for discrimination between alpha decay events in TPB and nuclear-recoil events in noble liquid detectors.

Ca2+ permeability through rat cloned alpha9-containing nicotinic acetylcholine receptors.

PubMed

Fucile, Sergio; Sucapane, Antonietta; Eusebi, Fabrizio

2006-04-01

We investigated the functional properties of rat alpha9 and alpha9alpha10 nicotinic acetylcholine receptors (nAChRs) expressed by transient transfection in the rat GH4C1 cell line, using both Ca(2+) imaging and whole-cell recording. Acute applications of ACh generated short-delay fast-rising and quick-decaying Ca(2+) transients, suppressed in Ca(2+)-free medium and invariably accompanied by the activation of whole-cell inward currents. The mean amplitude of ACh-induced currents was as small as -16 pA in alpha9 subunit cDNA-transfected GH4C1 cells (alpha9-GH4C1), while they were much larger (range: -150 to -300 pA) in alpha9alpha10 subunit cDNAs-transfected GH4C1 cells (alpha9alpha10-GH4C1). Currents were not activated by nicotine, were blocked by methyllycaconitine and were ACh concentration-dependent. Because the Ca(2+) permeability of alpha9-containing nAChRs has been estimated in immortalized cochlear UB/OC-2 mouse cells, we also characterized the ACh-induced responses in these cells. Unlike alpha9- and alpha9alpha10-GH4C1 cells, UB/OC-2 cells responded to ACh with both long-delay methyllycaconitine-insensitive whole-cell currents and long-lasting Ca(2+) transients, the latter being detected in the absence of Ca(2+) in the extracellular medium and being suppressed by the Ca(2+)-ATPase inhibitor thapsigargin, known to deplete IP(3)-sensitive stores. These results indicated the involvement of muscarinic nAChRs and the lack of functional ACh-gated receptor channels in UB/OC-2 cells. Thus, we measured the fractional Ca(2+) current (P(f), i.e. the percentage of total current carried by Ca(2+) ions) in alpha9alpha10-GH4C1, obtaining a P(f) value of 22 +/- 4%; this is the largest value estimated to date for a ligand-gated receptor channel. The physiological role played by Ca(2+) entry through alpha9-containing nAChRs gated by ACh is discussed.

Nonlinear Recurrent Dynamics and Long-Term Nonstationarities in EEG Alpha Cortical Activity: Implications for Choosing Adequate Segment Length in Nonlinear EEG Analyses.

PubMed

Cerquera, Alexander; Vollebregt, Madelon A; Arns, Martijn

2018-03-01

Nonlinear analysis of EEG recordings allows detection of characteristics that would probably be neglected by linear methods. This study aimed to determine a suitable epoch length for nonlinear analysis of EEG data based on its recurrence rate in EEG alpha activity (electrodes Fz, Oz, and Pz) from 28 healthy and 64 major depressive disorder subjects. Two nonlinear metrics, Lempel-Ziv complexity and scaling index, were applied in sliding windows of 20 seconds shifted every 1 second and in nonoverlapping windows of 1 minute. In addition, linear spectral analysis was carried out for comparison with the nonlinear results. The analysis with sliding windows showed that the cortical dynamics underlying alpha activity had a recurrence period of around 40 seconds in both groups. In the analysis with nonoverlapping windows, long-term nonstationarities entailed changes over time in the nonlinear dynamics that became significantly different between epochs across time, which was not detected with the linear spectral analysis. Findings suggest that epoch lengths shorter than 40 seconds neglect information in EEG nonlinear studies. In turn, linear analysis did not detect characteristics from long-term nonstationarities in EEG alpha waves of control subjects and patients with major depressive disorder patients. We recommend that application of nonlinear metrics in EEG time series, particularly of alpha activity, should be carried out with epochs around 60 seconds. In addition, this study aimed to demonstrate that long-term nonlinearities are inherent to the cortical brain dynamics regardless of the presence or absence of a mental disorder.

A one-dimensional free energy surface does not account for two-probe folding kinetics of protein alpha(3)D.

PubMed

Liu, Feng; Dumont, Charles; Zhu, Yongjin; DeGrado, William F; Gai, Feng; Gruebele, Martin

2009-02-14

We present fluorescence-detected measurements of the temperature-jump relaxation kinetics of the designed three-helix bundle protein alpha(3)D taken under solvent conditions identical to previous infrared-detected kinetics. The fluorescence-detected rate is similar to the IR-detected rate only at the lowest temperature where we could measure it (326 K). The fluorescence-detected rate decreases by a factor of 3 over the 326-344 K temperature range, whereas the IR-detected rate remains nearly constant over the same range. To investigate this probe dependence, we tested an extensive set of physically reasonable one-dimensional (1D) free energy surfaces by Langevin dynamics simulation. The simulations included coordinate- and temperature-dependent roughness, diffusion coefficients, and IR/fluorescence spectroscopic signatures. None of these can reproduce the IR and fluorescence data simultaneously, forcing us to the conclusion that a 1D free energy surface cannot accurately describe the folding of alpha(3)D. This supports the hypothesis that alpha(3)D has a multidimensional free energy surface conducive to downhill folding at 326 K, and that it is already an incipient downhill folder with probe-dependent kinetics near its melting point.

Molecular characterization and heterologous expression of a Xanthophyllomyces dendrorhous α-glucosidase with potential for prebiotics production.

PubMed

Gutiérrez-Alonso, Patricia; Gimeno-Pérez, María; Ramírez-Escudero, Mercedes; Plou, Francisco J; Sanz-Aparicio, Julia; Fernández-Lobato, María

2016-04-01

Basidiomycetous yeast Xanthophyllomyces dendrorhous expresses an α-glucosidase with strong transglycosylation activity producing prebiotic sugars such as panose and an unusual tetrasaccharides mixture including α-(1-6) bonds as major products, which makes it of biotechnological interest. Initial analysis pointed to a homodimeric protein of 60 kDa subunit as responsible for this activity. In this study, the gene Xd-AlphaGlu was characterized. The 4131-bp-long gene is interrupted by 13 short introns and encodes a protein of 990 amino acids (Xd-AlphaGlu). The N-terminal sequence of the previously detected 60 kDa protein resides in this larger protein at residues 583-602. Functionality of the gene was proved in Saccharomyces cerevisiae, which produced a protein of about 130 kDa containing Xd-AlphaGlu sequences. All properties of the heterologously expressed protein, including thermal and pH profiles, activity on different substrates, and ability to produce prebiotic sugars were similar to that of the α-glucosidase produced in X. dendrorhous. No activity was detected in S. cerevisiae containing exclusively the 1256-bp from gene Xd-AlphaGlu that would encode synthesis of the 60 kDa protein previously detected. Data were compatible with an active monomeric α-glucosidase of 990 amino acids and an inactive hydrolysis product of 60 kDa. Protein Xd-AlphaGlu contained most of the elements characteristic of α-glucosidases included in the glycoside hydrolases family GH31 and its structural model based on the homologous human maltase-glucoamylase was obtained. Remarkably, the Xd-AlphaGlu C-terminal domain presents an unusually long 115-residue insertion that could be involved in this enzyme's activity against long-size substrates such as maltoheptaose and soluble starch.

Photoelectrochemical detection of alpha-fetoprotein based on ZnO inverse opals structure electrodes modified by Ag2S nanoparticles

PubMed Central

Jiang, Yandong; Liu, Dali; Yang, Yudan; Xu, Ru; Zhang, Tianxiang; Sheng, Kuang; Song, Hongwei

2016-01-01

In this work, a new photoelectrochemical biosensor based on Ag2S nanoparticles (NPs) modified macroporous ZnO inverse opals structure (IOs) was developed for sensitive and rapid detection of alpha fetal protein (AFP). Small size and uniformly dispersed Ag2S NPs were prepared using the Successive Ionic Layer Adsorption And Reaction (SILAR) method, which were adsorbed on ZnO IOs surface and frame work as matrix for immobilization of AFP. The composite structure of ZnO/Ag2S expanded the scope of light absorption to long wavelength, which can make full use of the light energy. Meanwhile, an effective matching of energy levels between the conduction bands of Ag2S and ZnO are beneficial to the photo-generated electrons transfer. The biosensors based on FTO (fluorine-doped tinoxide) ZnO/Ag2S electrode showed enough sensitivity and a wide linear range from 0.05 ng/mL to 200 ng/mL with a low detection limit of 8 pg/mL for the detection of AFP. It also exhibited high reproducibility, specificity and stability. The proposed method was potentially attractive for achieving excellent photoelectrochemical biosensor for detection of other proteins. PMID:27922086

Detection and identification of plasma progesterone metabolites in the female Florida manatee (Trichechus manatus latirostris) using GC/MS/MS.

PubMed

Tripp, K M; Dubois, M; Delahaut, P; Verstegen, J P

2009-08-01

Florida manatees (Trichechus manatus latirostris) have relatively low peripheral concentrations of progesterone (P4). The objective of this study was to determine if these relatively low P4 concentrations are associated with a high ratio of progestin metabolites and to document metabolite concentrations from individual blood samples obtained from manatees during diestrus or pregnancy. Metabolites known to exist in elephants-terrestrial manatee relatives-were targeted. These included 5alpha-reduced progestins (5alpha-pregnane-3,20-dione [5alpha-DHP] and 3alpha-hydroxy-5alpha-pregnan-20-one [5alpha-P3-OH]) and 17alpha-hydroxyprogesterone (17alpha-OHP), which occurs in Asian elephants. An additional, inactive metabolite, 20alpha-hydroxyprogesterone (20alpha-OHP), indicative of P4 overproduction, was also targeted. Progesterone itself was the predominant progestin detected in pregnant and nonpregnant manatee plasma (n = 10) using gas chromatography-mass spectrometry with tandem quadrupole detectors (GC/MS/MS). Progesterone concentrations in pregnant females varied from early (moderate to high) through mid and late (low) pregnancy. Progesterone concentrations ranged from low to high in nonpregnant, nonlactating females. The most commonly detected metabolite was 5alpha-P3-OH (n = 7), which occurred in pregnant (lower limit of detection [LLOD] to high) and nonpregnant (trace to high) females. The 5alpha-DHP metabolite was also detected in pregnant (LLOD to moderate) and nonpregnant (low) females. The 17alpha-OHP metabolite was not detected in any tested female. The 20alpha-OHP metabolite was detected in one nonpregnant, nonlactating, captive female (LLOD). Metabolites were most prevalent during early pregnancy, concurrent with maximum P4 concentrations. Based on their concentrations in peripheral circulation, we inferred that these metabolites may have, opposite to elephants, a limited physiologic role during luteal, pregnant, and nonpregnant phases in the manatee.

Confirmation of hormones in animal serum by liquid chromatography/tandem mass spectrometry according to European Commission Decision 2002/657.

PubMed

McDonald, Mark; Malone, Edward; McBride, John

2010-01-01

A novel and rapid method was developed and validated for the confirmation of endogenous and synthetic hormones in animal serum using LC/MS/MS. Detection of 17 beta-estradiol and beta-testosterone below the respective European Union-recommended levels of 0.1 and 0.5 microg/L was achieved, as was a required performance level of 0.1 microg/L for 17 alpha-estradiol and 0.5 microg/L for 17 alpha-testosterone, medroxyprogesterone-17-acetate, and progesterone. The method was established with dilution of serum followed by ion-exchange SPE, LC separation and MS detection with electrospray ionization, selected reaction monitoring, and positivelnegative switching. Two characteristic transitions were monitored for each analyte. The method was applied to bovine, ovine, porcine, equine, and avian samples and validated according to European Commission Decision 2002/657/EC and accepted for ISO/IEC 17025:2005 accreditation. An extended calibration curve allows naturally occurring levels of endogenous hormones to be quantified. Recoveries ranged from 97.3% for 17 alpha-testosterone to 102.0% for 17 alpha-estradiol. The decision limit CCalpha ranged from 0.02 microg/L for 17 alpha- and beta-estradiol to 0.12 microg/L for progesterone. Detection capability CCbeta ranged from 0.03 microg/L for 17 a-estradiol to 0.20 microg/L for progesterone.

Detecting Circumstellar ``Hydrogen Wall'' Emission Around a Nearby, Sun-like Star

NASA Astrophysics Data System (ADS)

Wood, Brian

1999-07-01

Using the long-slit spectroscopy capabilities of STIS, we propose to try to detect for the first time nebular Lyman- Alpha emission surrounding a Sun-like star produced by the interaction of its stellar wind with the ISM. Such ``hydrogen walls'' have likely been detected in absorption around the Sun and several other nearby stars using GHRS Lyman-Alpha spectra. However, most of these detections are tentative due to the difficulty in separating the H-wall absorption from the interstellar H I absorption. Furthermore, even if one accepts the reality of the detected hot H I absorption components, it is impossible to prove that circumstellar material is in fact responsible. We propose to circumvent these difficulties by detecting a hydrogen wall in emission around 40 Eri A, which is one of the stars for which a tentative H-wall detection already exists. A successful detection of the expected circumstellar emission would validate the previous Lyman-Alpha aborption line studies, a nd the combined spectroscopic and spatial information provided by long-slit spectroscopy would contribute valuable new information on the stellar wind of 40 Eri A and how it interacts with the ISM, especially when compared with models that we will construct of 40 Eri A's ``astrosphere.'' This new information includes a direct measurement of the distance to the stellar bow shock, information that we do not possess for any other nearby star, including the Sun.

Altered long-range alpha-band synchronization during visual short-term memory retention in children born very preterm.

PubMed

Doesburg, Sam M; Ribary, Urs; Herdman, Anthony T; Miller, Steven P; Poskitt, Kenneth J; Moiseev, Alexander; Whitfield, Michael F; Synnes, Anne; Grunau, Ruth E

2011-02-01

Children born very preterm, even when intelligence is broadly normal, often experience selective difficulties in executive function and visual-spatial processing. Development of structural cortical connectivity is known to be altered in this group, and functional magnetic resonance imaging (fMRI) evidence indicates that very preterm children recruit different patterns of functional connectivity between cortical regions during cognition. Synchronization of neural oscillations across brain areas has been proposed as a mechanism for dynamically assigning functional coupling to support perceptual and cognitive processing, but little is known about what role oscillatory synchronization may play in the altered neurocognitive development of very preterm children. To investigate this, we recorded magnetoencephalographic (MEG) activity while 7-8 year old children born very preterm and age-matched full-term controls performed a visual short-term memory task. Very preterm children exhibited reduced long-range synchronization in the alpha-band during visual short-term memory retention, indicating that cortical alpha rhythms may play a critical role in altered patterns functional connectivity expressed by this population during cognitive and perceptual processing. Long-range alpha-band synchronization was also correlated with task performance and visual-perceptual ability within the very preterm group, indicating that altered alpha oscillatory mechanisms mediating transient functional integration between cortical regions may be relevant to selective problems in neurocognitive development in this vulnerable population at school age. Copyright © 2010 Elsevier Inc. All rights reserved.

Spectral measurements of alpha-induced radioluminescence in various gases

NASA Astrophysics Data System (ADS)

Brett, Jaclyn; Koehler, Katrina E.; Bischak, Michael; Famiano, Michael; Jenkins, Jared; Klankowski, Levi; Niraula, Prashantamani; Pancella, Paul; Lakis, Rollin

2017-12-01

Radioluminescent emission in Ar, N2, O2, and dry air at P = 1 atm was observed induced by 5 MeV α particles. The wavelength range with a single detector spanned 250-1100 nm, extending the range well into the UV and IR bands with a single detector. Measured spectral lines for alpha-induced luminescence were corrected for detector transmission and intensities compared to previous work. The exploration of multiple gases over a wide frequency range opens the door to security and remote sensing applications, where different environments are routinely encountered. This work provides spectra that can be used in guiding future filter development focusing on remote alpha detection.

Growth and Characterization of alpha-PbO for Room Temperature Radiation Detection

NASA Astrophysics Data System (ADS)

Ford, Erin Leigh

A global trading structure and high throughput of shipping containers into ports around the world increases the chance of nuclear terrorism via cargo containers. Harmless radioactive sources confuse and impede detection of the materials that pose a real threat, making spectroscopy difficult and requiring detectors with high resolution. The current methods that are used to check containers in ports have security flaws, and only 5% of all shipping containers are checked. The development of semiconductor gamma-ray detectors is one of the protocols being advanced to alleviate this risk because they can function at room temperature and they are cost effective, easily produced, and have high resolution. This dissertation has addressed the current lack of "perfect" room temperature detector materials by investigating alpha-PbO, a novel material in this field. This includes the development of a growth process for alpha-PbO thin films, as well as its structural and performance characterization as a detector material. Because we intend alpha-PbO to be a photoconductive detector, it should have certain properties. A photoconductive detector consists of a highly resistive material with a voltage bias across it. It absorbs incident gamma-rays, creating electron-hole pairs that provide a signal. To function well, it must have a high atomic number and a high density in order to absorb high-energy photons via the photoelectric effect. It should also have a large resistivity and a wide band gap to avoid large leakage currents at room temperature. Finally, it must have good charge carrier transport properties and detector resolution in order to be able to determine the characteristic energy peaks of the radiation-emitting source. We chose alpha-PbO because it has a very high Z and a very high density and a band gap in the correct range. It also has a rich history of use as a photoconductor that reaches back to the 1950s. Numerous methods have been used to grow thin films of alpha-PbO. However, rarely are those films single phase or highly oriented. Pulsed laser deposition provides a method to grow epitaxial thin films of alpha-PbO. The structure of the grown films was characterized using X-ray diffraction 2θ-o scans, rocking curves, and reciprocal space mapping. Feedback from a parameterized study of the structural characterization enabled optimization of the growth process to improve the quality of the thin films. The methods used for the optical measurement of alpha-PbO films included absorption spectroscopy and ellipsometry. Determination of the spectral absorption coefficient was achieved by transmission spectroscopy and reflection spectroscopy via a PerkinElmer Lambda 950 UV-Vis spectrophotometer. Study of the electronic and transport properties of alpha-PbO is important in order to understand how the material will behave as a radiation detector. Spectral photoconductivity was measured to ensure that alpha-PbO's response to light was large enough for it to be a useful detector material and to confirm the band gap measurements. In the field of detector materials, the mutau-product is commonly used as a figure of merit because it enables a measurement of the trapping length of the charge carriers within the detector. Many's equation, which is a derivation of the photocurrent with respect to the applied voltage across a wide band gap semiconductor, is one of the methods used to determine the mutau-product. The photocurrent voltage measurements were obtained from the 0.5 V to 80 V range. This data was difficult to fit with Many's equation over that whole range. Higher voltages displayed deviation from ideal behavior due to the contact effects, but at the lower voltages the data were unaffected. Fits to the lower voltage range, from 0.5 V to 10 V, yielded mutau = 6.8 x 10-4 cm2/V. Room temperature photoconductors will ultimately be used to detect gamma-rays; however, thin films do not have enough stopping power to absorb the total energy of a gamma-ray. Therefore, we study the alpha-PbO detector response to radiation in the form of alpha particles because they are large, charged, and relatively easy to stop. SRIM calculation estimated that alpha particles have a range of up to 16 mum in alpha-PbO. The initial long-duration film growth yielded films that were ˜ 8 mum thick. Therefore, a full energy peak from alpha particles was not seen in alpha-PbO. We did see a shoulder protruding out of the noise peak due to the charge carriers that were created before the alpha particles escaped the detector volume. (Abstract shortened by UMI.)

Intraoperative detection of 18F-FDG-avid tissue sites using the increased probe counting efficiency of the K-alpha probe design and variance-based statistical analysis with the three-sigma criteria

PubMed Central

2013-01-01

Background Intraoperative detection of 18F-FDG-avid tissue sites during 18F-FDG-directed surgery can be very challenging when utilizing gamma detection probes that rely on a fixed target-to-background (T/B) ratio (ratiometric threshold) for determination of probe positivity. The purpose of our study was to evaluate the counting efficiency and the success rate of in situ intraoperative detection of 18F-FDG-avid tissue sites (using the three-sigma statistical threshold criteria method and the ratiometric threshold criteria method) for three different gamma detection probe systems. Methods Of 58 patients undergoing 18F-FDG-directed surgery for known or suspected malignancy using gamma detection probes, we identified nine 18F-FDG-avid tissue sites (from amongst seven patients) that were seen on same-day preoperative diagnostic PET/CT imaging, and for which each 18F-FDG-avid tissue site underwent attempted in situ intraoperative detection concurrently using three gamma detection probe systems (K-alpha probe, and two commercially-available PET-probe systems), and then were subsequently surgical excised. Results The mean relative probe counting efficiency ratio was 6.9 (± 4.4, range 2.2–15.4) for the K-alpha probe, as compared to 1.5 (± 0.3, range 1.0–2.1) and 1.0 (± 0, range 1.0–1.0), respectively, for two commercially-available PET-probe systems (P < 0.001). Successful in situ intraoperative detection of 18F-FDG-avid tissue sites was more frequently accomplished with each of the three gamma detection probes tested by using the three-sigma statistical threshold criteria method than by using the ratiometric threshold criteria method, specifically with the three-sigma statistical threshold criteria method being significantly better than the ratiometric threshold criteria method for determining probe positivity for the K-alpha probe (P = 0.05). Conclusions Our results suggest that the improved probe counting efficiency of the K-alpha probe design used in conjunction with the three-sigma statistical threshold criteria method can allow for improved detection of 18F-FDG-avid tissue sites when a low in situ T/B ratio is encountered. PMID:23496877

Spectral Measurements of Alpha-induced Radioluminescence in Various Gases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brett, Jaclyn; Koehler, Katrina Elizabeth; Bischak, Michael

Radioluminescent emission in Ar, N 2, O 2, and dry air at P=1 atm was observed induced by 5 MeV α particles. The wavelength range with a single detector spanned 250–1100 nm, extending the range well into the UV and IR bands with a single detector. Measured spectral lines for alpha-induced luminescence were corrected for detector transmission and intensities compared to previous work. The exploration of multiple gases over a wide frequency range opens the door to security and remote sensing applications, where different environments are routinely encountered. Finally, this work provides spectra that can be used in guiding futuremore » filter development focusing on remote alpha detection.« less

Spectral Measurements of Alpha-induced Radioluminescence in Various Gases

DOE PAGES

Brett, Jaclyn; Koehler, Katrina Elizabeth; Bischak, Michael; ...

2017-09-06

Radioluminescent emission in Ar, N 2, O 2, and dry air at P=1 atm was observed induced by 5 MeV α particles. The wavelength range with a single detector spanned 250–1100 nm, extending the range well into the UV and IR bands with a single detector. Measured spectral lines for alpha-induced luminescence were corrected for detector transmission and intensities compared to previous work. The exploration of multiple gases over a wide frequency range opens the door to security and remote sensing applications, where different environments are routinely encountered. Finally, this work provides spectra that can be used in guiding futuremore » filter development focusing on remote alpha detection.« less

223Ra-dichloride spectrometric characterization: Searching for the presence of long-lived isotopes with radiological protection implications.

PubMed

Sánchez-Jiménez, J; López-Montes, A; Núñez-Martínez, L; Villa-Abaunza, A; Fraile, L M; Sánchez-Tembleque, V; Udías, J M

2017-03-01

223 Ra-dichloride was approved with the commercial name of Xofigo in 2014 for treatment of metastatic castration-resistant prostate cancer. 223 Ra is obtained by neutron irradiation of 226 Ra yielding 227 Ac, which decays to 227 Th and 223 Fr, both decaying to 223 Ra. Since 223 Ra is predominantly (95.3%) an alpha emitter with a 11.42days long half-life, the radiopharmaceutical, its remnants, the patient, and waste material can be managed and disposed with low radiation protection requirements. 227 Ac is a long-lived (T 1/2 =21.77years) beta emitter that demands strong radiation protection measures. In particular waste disposal has to follow the International Atomic Energy Agency (IAEA) and European Commission (EC) regulations. Since 227 Ac is involved in the production of 223 Ra, an impurity analysis of each batch is required after production. Due to time restrictions, the manufacturer's detection limit (<0.001%) exceeds the one required to assure that 227 Ac concentrations are below direct disposal levels. To improve the detection limit, long-term accurate spectroscopy is required. Alpha and gamma spectroscopy measurements were carried out at the Complutense University Nuclear Physics Laboratory. After twelve months follow up of a sample, 227 Ac concentration was found to be smaller than 10 -9 . This allows for direct waste disposal and no additional radiation protection restrictions than those required for 223 Ra. The presence of contamination by other radioisotopes was also ruled out by this experiment. Specifically 226 Ra, involved in 223 Ra production as the original parent and with a very long-lived (T 1/2 =1577years) alpha emitter, was also below the experimental detection limit. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Alpha-decay-induced fracturing in zircon - The transition from the crystalline to the metamict state

NASA Technical Reports Server (NTRS)

Chakoumakos, Bryan C.; Murakami, Takashi; Lumpkin, Gregory R.; Ewing, Rodney C.

1987-01-01

Zonation due to alpha-decay damage in a natural single crystal of zircon from Sri Lanka is discussed. The zones vary in thickness on a scale from one to hundreds of microns. The uranium and thorium concentrations vary from zone to zone such that the alpha decay dose is between 0.2 x 10 to the 16th and 0.8 x 10 to the 16th alpha-events per milligram. The transition from the crystalline to the aperiodic metamict state occurs over this dose range. At doses greater than 0.8 x 10 to the 16th alpha events/mg there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.

Characterization of inhibin forms and their measurement by an inhibin alpha-subunit ELISA in serum from postmenopausal women with ovarian cancer.

PubMed

Robertson, D M; Stephenson, T; Pruysers, E; McCloud, P; Tsigos, A; Groome, N; Mamers, P; Burger, H G

2002-02-01

The aim of this study was to characterize the molecular wt forms of inhibins A and B and its free alpha-subunit present in serum from women with ovarian cancer as a basis for developing improved monoclonal antibody-based inhibin assays for monitoring ovarian cancer. Three new inhibin alpha-subunit (alphaC) ELISAs were developed using monoclonal antibodies directed to three nonoverlapping peptide regions of the alphaC region of the inhibin alpha-subunit. To characterize serum inhibin molecular wt forms present in women with ovarian cancer, existing inhibin immunoassays (inhibin A, inhibin B, and pro-alphaC) and the new alphaC ELISAs were applied to sera from women with granulosa cell tumors and mucinous carcinomas previously fractionated using a combined immunoaffinity chromatography, preparative SDS-PAGE, and electroelution procedure. The distribution and molecular size of dimeric inhibins and alpha-subunit detected were consistent with known mol wt forms of inhibins A and B and inhibin alpha-subunit and their precursor forms present in serum and follicular fluid from healthy women. The alphaC ELISAs recognized all known forms of inhibin and the free inhibin alpha-subunit, although differences between alphaC ELISAs were observed in their ability to detect high mol wt forms. To assess which of the alphaC ELISAs was preferred in application to ovarian cancer, the alphaC ELISAs were applied to serum from a range of normal postmenopausal women (n = 61) and postmenopausal women (n = 152) with ovarian (serous, mucinous, endometrioid, clear cell carcinomas, and granulosa cell tumors) and nonovarian (breast and colon) cancers. Despite differences in their ability to detect high mol wt forms of inhibin, the alphaC ELISAs showed similar sensitivity (i.e. proportion of cancer patients correctly detected) and specificity (proportion of controls correctly detected) indexes in the detection of mucinous carcinomas (84% and 95%) and granulosa cell tumors (100% and 95%) compared with earlier inhibin RIA or polyclonal antibody-based immunofluorometric assays. A combination of the alphaC ELISAs with the CA125 assay, an ovarian tumor marker that has a high sensitivity and specificity for other ovarian cancers (serous, clear cell, and endometrioid), resulted in an increase in sensitivity/specificity indexes (95% and 95%) for the all ovarian cancer group. These new monoclonal antibody-based inhibin alphaC ELISAs now provide practical and sensitive assays suitable for evaluation as diagnostic tests for monitoring ovarian cancers.

Immunological monitoring of dry-cleaning shop workers--exposure to tetrachloroethylene.

PubMed

Andrýs, C; Hanovcová, I; Chýlková, V; Tejral, J; Eminger, S; Procházková, J

1997-09-01

A panel of immunological parameters has been examined in a group of dry-cleaning workers (n = 21) and in a control group of administrators (n = 16) from the same plant. The results were also compared to long-term laboratory reference values (LRV) (n = 14-311). External exposure to tetrachloroethylene (PER) was represented by TWA (8 h) values in the range 11-752 mg PER/m3. Biological monitoring showed an amount from 9 to 344 mg PER/m3 in exhaled air by the end of workshift. 1. The exposed dry-cleaning workers compared to the controls from the plant had statistically significant changes in metabolic activity of phagocytes, alpha 2-macroglobulin, C3 and C4 complement component, salivary secretory IgA, and blastic transformation test. Most of the values were within the range of normal values. 2. The exposed dry-cleaning workers had several abnormal immune parameters compared to the long-term laboratory values (LRV) especially in the alpha 2-macroglobulin, C3 and percentage of T-lymphocytes. Most of the changes, even those that were statistically significant, were still within the range of normal values, but they might be classified as trends or shifts away from normal (spontaneous blastic transformation, absolute number of phagocyting cells, coeruloplasmin, circulating immunocomplexes, serum lysozyme). 3. The non-exposed controls from the same plant showed both quantitative and qualitative differences when compared to the LRV. Changes were seen in IgG, C4, CSI and in increased spontaneous metabolic activity of leucocytes, total leucocyte count, absolute number of phagocyting cells, alpha 2-macroglobulin, prealbumin, C4, circulating immunocomplexes and serum lysozyme. 4. The distribution analysis of all results detected a large number of abnormal values in both groups, more in the at-risk group. 5. As inhalation was the main route of PER exposure it was concluded that the changes might represent aspects of the response of the respiratory immune system, mainly of the alveolar macrophages. Additional postinfection effects could not be excluded in both studied groups. Individual differences in immune reactivity as well as individual range of exposure should be taken into consideration.

Polycarbonates: a long-term highly sensitive radon monitor

NASA Astrophysics Data System (ADS)

Pressyanov, D.; Buysse, J.; Poffijn, A.; Meesen, G.; Van Deynse, A.

2000-06-01

An approach for long-term (either retrospective or prospective) 222Rn measurements is proposed that is based on the combination of the high radon absorption ability of some polycarbonates with their alpha track-etch properties. The detection limit is projected to be <10 Bq m -3 for an exposure time of 20 yr.

A Very Large Array search for emission from HI associated with nearby Lyman alpha absorbers

NASA Technical Reports Server (NTRS)

Van Gorkom, J. H.; Bahcall, J. N.; Jannuzi, B. T.; Schneider, D. P.

1993-01-01

We present a sensitive Very Large Array (VLA) search for H I emission from the vicinity of the Lyman alpha clouds in the Virgo Cluster, which were recently discovered with Hubble Space Telescope (HST) in absorption toward the nearest quasar 3C273. We searched an area of 40 by 40 arcmin centered on 3C273, covering a velocity range from 840 to 1840 km/s. The bandpass was self-calibrated on 3C273 leading to a spectral dynamic range of better than 10(exp 5) to 1. No H I was detected. The rms noise in the final images corresponds to a 3 sigma column density sensitivity of 2.8 x 10(exp 19) sq cm on scales of a few kpc. Small H I clouds could have been detected down to a few times 10(exp 6) solar mass. Our failure to detect H I emission at the higher column densities sets a lower limit to the radius of the Lyman alpha clouds of 3.9 kpc, assuming a spherical geometry.

A new scanning system for alpha decay events as calibration sources for range-energy relation in nuclear emulsion

NASA Astrophysics Data System (ADS)

Yoshida, J.; Kinbara, S.; Mishina, A.; Nakazawa, K.; Soe, M. K.; Theint, A. M. M.; Tint, K. T.

2017-03-01

A new scanning system named "Vertex picker" has been developed to rapid collect alpha decay events, which are calibration sources for the range-energy relation in nuclear emulsion. A computer-controlled optical microscope scans emulsion layers exhaustively, and a high-speed and high-resolution camera takes their micrographs. A dedicated image processing picks out vertex-like shapes. Practical operations of alpha decay search were demonstrated by emulsion sheets of the KEK-PS E373 experiment. Alpha decays of nearly 28 events were detected in eye-check work on a PC monitor per hour. This yield is nearly 20 times more effective than that by the conventional eye-scan method. The speed and quality is acceptable for the coming new experiment, J-PARC E07.

Abnormal resting-state cortical coupling in chronic tinnitus

PubMed Central

Schlee, Winfried; Hartmann, Thomas; Langguth, Berthold; Weisz, Nathan

2009-01-01

Background Subjective tinnitus is characterized by an auditory phantom perception in the absence of any physical sound source. Consequently, in a quiet environment, tinnitus patients differ from control participants because they constantly perceive a sound whereas controls do not. We hypothesized that this difference is expressed by differential activation of distributed cortical networks. Results The analysis was based on a sample of 41 participants: 21 patients with chronic tinnitus and 20 healthy control participants. To investigate the architecture of these networks, we used phase locking analysis in the 1–90 Hz frequency range of a minute of resting-state MEG recording. We found: 1) For tinnitus patients: A significant decrease of inter-areal coupling in the alpha (9–12 Hz) band and an increase of inter-areal coupling in the 48–54 Hz gamma frequency range relative to the control group. 2) For both groups: an inverse relationship (r = -.71) of the alpha and gamma network coupling. 3) A discrimination of 83% between the patient and the control group based on the alpha and gamma networks. 4) An effect of manifestation on the distribution of the gamma network: In patients with a tinnitus history of less than 4 years, the left temporal cortex was predominant in the gamma network whereas in patients with tinnitus duration of more than 4 years, the gamma network was more widely distributed including more frontal and parietal regions. Conclusion In the here presented data set we found strong support for an alteration of long-range coupling in tinnitus. Long-range coupling in the alpha frequency band was decreased for tinnitus patients while long-range gamma coupling was increased. These changes discriminate well between tinnitus and control participants. We propose a tinnitus model that integrates this finding in the current knowledge about tinnitus. Furthermore we discuss the impact of this finding to tinnitus therapies using Transcranial Magnetic Stimulation (TMS). PMID:19228390

Direct determination of the estrogenic compounds 8-prenylnaringenin, zearalenone, alpha- and beta-zearalenol in beer by liquid chromatography-mass spectrometry.

PubMed

Maragou, Niki C; Rosenberg, Erwin; Thomaidis, Nikolaos S; Koupparis, Michael A

2008-08-15

A novel LC-ESI-MS method for the simultaneous determination of four of the most significant estrogenic compounds naturally occurring in beer, 8-prenylnaringenin (8-PN), zearalenone (ZON), alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL) which requires minimal sample preparation was developed using a chemometric approach. Experimental design was applied to assess the effects of the LC-ESI-MS parameters (mobile phase flow rate, drying gas flow, nebuliser pressure and capillary potential) on the obtained signal and to optimize the values in order to provide maximum sensitivity and detectability. The proposed method is simple, consisting only of degassing the beer and diluting with water (1:1, v/v) before injection. Comparison between the two internal standards used, zearalanone (ZAN) and 4,2'-dihydroxychalcone (4,2'-DHC), showed that ZAN performs better as internal standard not only for the mycotoxins but for 8-PN as well, giving lower % RSDs. Under inter-day conditions mean recoveries were 107% for ZON, 87.8% for alpha-ZOL, 72.8% for beta-ZOL, and 77.5% for 8-PN. The corresponding % RSDs ranged between 5.0 and 8.0. The method limits of detection were 1.3, 1.4, 1.0 and 0.8 ng mL(-1) for ZON, alpha-ZOL, beta-ZOL and 8-PN, respectively. The method was applied to 15 beer samples obtained from local supermarkets and the concentration of the phytoestrogen 8-PN in beer ranged between <0.8 and 38.6 ng mL(-1), while neither ZON nor its metabolites, alpha-ZOL and beta-ZOL, were detected.

Background canceling surface alpha detector

DOEpatents

MacArthur, D.W.; Allander, K.S.; Bounds, J.A.

1996-06-11

A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone. 5 figs.

Background canceling surface alpha detector

DOEpatents

MacArthur, Duncan W.; Allander, Krag S.; Bounds, John A.

1996-01-01

A background canceling long range alpha detector which is capable of providing output proportional to both the alpha radiation emitted from a surface and to radioactive gas emanating from the surface. The detector operates by using an electrical field between first and second signal planes, an enclosure and the surface or substance to be monitored for alpha radiation. The first and second signal planes are maintained at the same voltage with respect to the electrically conductive enclosure, reducing leakage currents. In the presence of alpha radiation and radioactive gas decay, the signal from the first signal plane is proportional to both the surface alpha radiation and to the airborne radioactive gas, while the signal from the second signal plane is proportional only to the airborne radioactive gas. The difference between these two signals is proportional to the surface alpha radiation alone.

The role of alpha oscillations for illusory perception

PubMed Central

Lange, Joachim; Keil, Julian; Schnitzler, Alfons; van Dijk, Hanneke; Weisz, Nathan

2014-01-01

Alpha oscillations are a prominent electrophysiological signal measured across a wide range of species and cortical and subcortical sites. Alpha oscillations have been viewed for a long time as an “idling” rhythm, purely reflecting inactive sites. Despite earlier evidence from neurophysiology, awareness that alpha oscillations can substantially influence perception and behavior has grown only recently in cognitive neuroscience. Evidence for an active role of alpha for perception comes mainly from several visual, near-threshold experiments. In the current review, we extend this view by summarizing studies showing how alpha-defined brain states relate to illusory perception, i.e. cases of perceptual reports that are not “objectively” verifiable by distinct stimuli or stimulus features. These studies demonstrate that ongoing or prestimulus alpha oscillations substantially influence the perception of auditory, visual or multisensory illusions. PMID:24931795

Resolution of G(s)alpha and G(q)alpha/G(11)alpha proteins in membrane domains by two-dimensional electrophoresis: the effect of long-term agonist stimulation.

PubMed

Matousek, P; Novotný, J; Svoboda, P

2004-01-01

Low-density membrane-domain fractions were prepared from S49 lymphoma cells and clone e2m11 of HEK293 cells expressing a large number of thyrotropin-releasing hormone receptor (TRH-R) and G(11)alpha by flotation on sucrose density gradients. The intact cell structure was broken by detergent-extraction, alkaline-treatment or drastic homogenization. Three types of low-density membranes were resolved by two-dimensional electrophoresis and analyzed for G(s)alpha (S49) or G(q)alpha/G11) (e2m11) content. Four individual immunoblot signals of Gsalpha protein were identified in S49 lymphoma cells indicating complete resolution of the long G(s)alpha L+/-ser and short G(s)alpha S+/-ser variants of G(s)alpha. All these were diminished by prolonged agonist (isoprenaline) stimulation. In e2m11-HEK cells, five different immunoblot signals were detected indicating post-translational modification of G proteins of G(q)alpha/G(11)alpha family. The two major spots corresponding to exogenously (over)expressed G(11)alpha and endogenous G(q)alpha were reduced; the minor spots diminished by hormonal stimulation. Parallel analysis by silver staining of the total protein content indicated that no major changes in protein composition occurred under these conditions. Our data thus indicate that agonist-stimulation of target cells results in down-regulation of all different members of G(s) and G(q)/G(11) families. This agonist-specific effect may be demonstrated in crude membrane as well as domain/raft preparations and it is not accompanied by changes in overall protein composition.

Determination of 17alpha-ethynylestradiol, carbamazepine, diazepam, simvastatin, and oxybenzone in fish livers.

PubMed

Kwon, Jeong-Wook; Armbrust, Kevin L; Vidal-Dorsch, Doris; Bay, Steven M

2009-01-01

A method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed for the determination of 17alpha-ethynylestradiol in fish liver; a second method using LC/MS was developed for the determination of carbamazepine, diazepam, simvastatin, and oxybenzone in fish liver. The fish liver samples were extracted and cleaned up by using liquid-liquid extraction and solid-phase extraction before the extracts were analyzed by LC/MS or LC/MS/MS with electrospray negative and positive ionization. Recoveries of the 5 target compounds from spiked catfish liver ranged from 72 +/- 2 to 100 +/- 3%. Limits of quantification for the 5 compounds were between 4.2 and 12.3 ng/g (wet weight). Ten turbot (Pleuronichthys verticalis) liver samples were analyzed; levels of 17alpha-ethynylestradiol, carbamazepine, simvastatin, and oxybenzone were below the detection limits. Diazepam was detected in all 10 fish liver samples at concentrations ranging from 23 to 110 ng/g (wet weight).

Registration of alpha particles in Makrofol-E nuclear track detectors

NASA Astrophysics Data System (ADS)

Rammah, Y. S.; Abdalla, Ayman M.; Ashraf, O.; Ashry, A. H.

2016-06-01

Fast detection of alpha particles in the range from 1 to 5 MeV in Makrofol-E polycarbonate nuclear track detectors (PCTDs) using a new chemical etchant was investigated. 252Cf and 241Am-thin open sources were used for irradiating Makrofol-E detectors with fission fragments and alpha particles in air at normal pressure and temperature (NPT). A chain of experimental work has been carried out using new etchants to register alpha particle in short time in Makrofol-E polycarbonate detectors. The etching efficiency were exhibited a clear dependence on the amount of methanol in the etching solution and etching time. The optimized chemical condition obtained at this stage of development for 200 μm Makrofol-E detectors are (8 ml of 10 N NaOH + 2 ml CH3OH) etching solutions at 60 °C for 3 h. In this study; it is possible to observe energy detection windows for Makrofol-E detectors according to applied etching duration. Makrofol-E introduced the characteristic Bragg peak, which indicates the advantages of this detector as alpha spectrometer. Consequently, the suggested new etchant can be developed for heavy ions detection and monitoring radon levels and its daughters.

TCAD simulation for alpha-particle spectroscopy using SIC Schottky diode.

PubMed

Das, Achintya; Duttagupta, Siddhartha P

2015-12-01

There is a growing requirement of alpha spectroscopy in the fields context of environmental radioactive contamination, nuclear waste management, site decommissioning and decontamination. Although silicon-based alpha-particle detection technology is mature, high leakage current, low displacement threshold and radiation hardness limits the operation of the detector in harsh environments. Silicon carbide (SiC) is considered to be excellent material for radiation detection application due to its high band gap, high displacement threshold and high thermal conductivity. In this report, an alpha-particle-induced electron-hole pair generation model for a reverse-biased n-type SiC Schottky diode has been proposed and verified using technology computer aided design (TCAD) simulations. First, the forward-biased I-V characteristics were studied to determine the diode ideality factor and compared with published experimental data. The ideality factor was found to be in the range of 1.4-1.7 for a corresponding temperature range of 300-500 K. Next, the energy-dependent, alpha-particle-induced EHP generation model parameters were optimised using transport of ions in matter (TRIM) simulation. Finally, the transient pulses generated due to alpha-particle bombardment were analysed for (1) different diode temperatures (300-500 K), (2) different incident alpha-particle energies (1-5 MeV), (3) different reverse bias voltages of the 4H-SiC-based Schottky diode (-50 to -250 V) and (4) different angles of incidence of the alpha particle (0°-70°).The above model can be extended to other (wide band-gap semiconductor) device technologies useful for radiation-sensing application. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Homogeneous Time-Resolved Fluorescence Immunoassay Method for the Measurement of Compound W

PubMed Central

Huang, Biao; Yu, Huixin; Bao, Jiandong; Zhang, Manda; Green, William L; Wu, Sing-Yung

2018-01-01

Objective: Using compound W (a 3,3′-diiodothyronine sulfate [T2S] immuno-crossreactive material)-specific polyclonal antibodies and homogeneous time-resolved fluorescence immunoassay assay techniques (AlphaLISA) to establish an indirect competitive compound W (ICW) quantitative detection method. Method: Photosensitive particles (donor beads) coated with compound W or T2S and rabbit anti-W antibody were incubated with biotinylated goat anti-rabbit antibody. This constitutes a detection system with streptavidin-coated acceptor particle. We have optimized the test conditions and evaluated the detection performance. Results: The sensitivity of the method was 5 pg/mL, and the detection range was 5 to 10 000 pg/mL. The intra-assay coefficient of variation averages <10% with stable reproducibility. Conclusions: The ICW-AlphaLISA shows good stability and high sensitivity and can measure a wide range of compound W levels in extracts of maternal serum samples. This may have clinical application to screen congenital hypothyroidism in utero. PMID:29449777

A Homogeneous Time-Resolved Fluorescence Immunoassay Method for the Measurement of Compound W.

PubMed

Huang, Biao; Yu, Huixin; Bao, Jiandong; Zhang, Manda; Green, William L; Wu, Sing-Yung

2018-01-01

Using compound W (a 3,3'-diiodothyronine sulfate [T 2 S] immuno-crossreactive material)-specific polyclonal antibodies and homogeneous time-resolved fluorescence immunoassay assay techniques (AlphaLISA) to establish an indirect competitive compound W (ICW) quantitative detection method. Photosensitive particles (donor beads) coated with compound W or T 2 S and rabbit anti-W antibody were incubated with biotinylated goat anti-rabbit antibody. This constitutes a detection system with streptavidin-coated acceptor particle. We have optimized the test conditions and evaluated the detection performance. The sensitivity of the method was 5 pg/mL, and the detection range was 5 to 10 000 pg/mL. The intra-assay coefficient of variation averages <10% with stable reproducibility. The ICW-AlphaLISA shows good stability and high sensitivity and can measure a wide range of compound W levels in extracts of maternal serum samples. This may have clinical application to screen congenital hypothyroidism in utero.

Predictions on the modes of decay of even Z superheavy isotopes within the range 104 ≤ Z ≤ 136

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Nithya, C.

2018-01-01

The decay modes and half lives of all the even Z isotopes of superheavy elements within the range 104 ≤ Z ≤ 136 have been predicted by comparing the alpha decay half-lives with the spontaneous fission half-lives. The Coulomb and proximity potential model for deformed nuclei (CPPMDN) and the shell-effect-dependent formula of Santhosh et al. are used to calculate the alpha half-lives and spontaneous fission half-lives respectively. For theoretical comparison the alpha decay half-lives are also calculated using Coulomb and proximity potential model (CPPM), the Viola-Seaborg-Sobiczewski semi-empirical (VSS) relation, the universal (UNIV) curve of Poenaru et al., the analytical formula of Royer and the universal decay law (UDL) of Qi et al. Another tool used for the evaluation of spontaneous fission half-lives is the semi-empirical formula of Xu et al. The nuclei with alpha decay half-lives less than spontaneous fission half-lives will survive fission and hence decay through alpha emission. The predicted half lives and decay modes are compared with the available experimental results. The one-proton and two-proton separation energies of all the isotopes are calculated to find nuclei which lie beyond the proton drip line. Among 1119 even Z nuclei within the range 104 ≤ Z ≤ 136, 164 nuclei show sequential alpha emission followed by subsequent spontaneous fission. Since the isotopes decay through alpha decay chain and the half-lives are in measurable range, these isotopes are predicted to be synthesized and detected in laboratory via alpha decay. 2 nuclei will decay by alpha decay followed by proton emission, 54 nuclei show full alpha chains, 642 nuclei will decay through spontaneous fission, 166 nuclei exhibit proton decay and 91 isotopes are found to be stable against alpha decay. All the isotopes are tabulated according to their decay modes. The study is intended to enhance further experimental investigations in superheavy region.

Fractals in biology and medicine

NASA Technical Reports Server (NTRS)

Havlin, S.; Buldyrev, S. V.; Goldberger, A. L.; Mantegna, R. N.; Ossadnik, S. M.; Peng, C. K.; Simons, M.; Stanley, H. E.

1995-01-01

Our purpose is to describe some recent progress in applying fractal concepts to systems of relevance to biology and medicine. We review several biological systems characterized by fractal geometry, with a particular focus on the long-range power-law correlations found recently in DNA sequences containing noncoding material. Furthermore, we discuss the finding that the exponent alpha quantifying these long-range correlations ("fractal complexity") is smaller for coding than for noncoding sequences. We also discuss the application of fractal scaling analysis to the dynamics of heartbeat regulation, and report the recent finding that the normal heart is characterized by long-range "anticorrelations" which are absent in the diseased heart.

Revisiting alpha decay-based near-light-speed particle propulsion.

PubMed

Zhang, Wenwu; Liu, Zhen; Yang, Yang; Du, Shiyu

2016-08-01

Interplanet and interstellar travels require long-term propulsion of spacecrafts, whereas the conventional schemes of propulsion are limited by the velocity of the ejected mass. In this study, alpha particles released by nuclear decay are considered as a potential solution for long-time acceleration. The principle of near-light-speed particle propulsion (NcPP) was elucidated and the stopping and range of ions in matter (SRIM) was used to predict theoretical accelerations. The results show that NcPP by means of alpha decay is feasible for long-term spacecraft propulsion and posture adjustment in space. A practical NcPP sail can achieve a speed >150km/s and reach the brink of the solar system faster than a mass equivalent solar sail. Finally, to significantly improve the NcPP sail, the hypothesis of stimulated acceleration of nuclear decay (SAND) was proposed, which may shorten the travel time to Mars to within 20 days. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oscillatory signatures of crossmodal congruence effects: An EEG investigation employing a visuotactile pattern matching paradigm.

PubMed

Göschl, Florian; Friese, Uwe; Daume, Jonathan; König, Peter; Engel, Andreas K

2015-08-01

Coherent percepts emerge from the accurate combination of inputs from the different sensory systems. There is an ongoing debate about the neurophysiological mechanisms of crossmodal interactions in the brain, and it has been proposed that transient synchronization of neurons might be of central importance. Oscillatory activity in lower frequency ranges (<30Hz) has been implicated in mediating long-range communication as typically studied in multisensory research. In the current study, we recorded high-density electroencephalograms while human participants were engaged in a visuotactile pattern matching paradigm and analyzed oscillatory power in the theta- (4-7Hz), alpha- (8-13Hz) and beta-bands (13-30Hz). Employing the same physical stimuli, separate tasks of the experiment either required the detection of predefined targets in visual and tactile modalities or the explicit evaluation of crossmodal stimulus congruence. Analysis of the behavioral data showed benefits for congruent visuotactile stimulus combinations. Differences in oscillatory dynamics related to crossmodal congruence within the two tasks were observed in the beta-band for crossmodal target detection, as well as in the theta-band for congruence evaluation. Contrasting ongoing activity preceding visuotactile stimulation between the two tasks revealed differences in the alpha- and beta-bands. Source reconstruction of between-task differences showed prominent involvement of premotor cortex, supplementary motor area, somatosensory association cortex and the supramarginal gyrus. These areas not only exhibited more involvement in the pre-stimulus interval for target detection compared to congruence evaluation, but were also crucially involved in post-stimulus differences related to crossmodal stimulus congruence within the detection task. These results add to the increasing evidence that low frequency oscillations are functionally relevant for integration in distributed brain networks, as demonstrated for crossmodal interactions in visuotactile pattern matching in the current study. Copyright © 2015 Elsevier Inc. All rights reserved.

Groundwater quality of the Gulf Coast aquifer system, Houston, Texas, 2010

USGS Publications Warehouse

Oden, Jeannette H.; Brown, Dexter W.; Oden, Timothy D.

2011-01-01

Gross alpha-particle activities and beta-particle activities for all 47 samples were analyzed at 72 hours after sample collection and again at 30 days after sample collection, allowing for the measurement of the activity of short-lived isotopes. Gross alpha-particle activities reported in this report were not adjusted for activity contributions by radon or uranium and, therefore, are conservatively high estimates if compared to the U.S. Environmental Protection Agency National Primary Drinking Water Regulation for adjusted gross alpha-particle activity. The gross alpha-particle activities at 30 days in the samples ranged from R0.60 to 25.5 picocuries per liter and at 72 hours ranged from 2.58 to 39.7 picocuries per liter, and the "R" preceding the value of 0.60 picocuries per liter refers to a nondetected result less than the sample-specific critical level. Gross beta-particle activities measured at 30 days ranged from 1.17 to 14.4 picocuries per liter and at 72 hours ranged from 1.97 to 4.4 picocuries per liter. Filtered uranium was detected in quantifiable amounts in all of the 47 wells sampled. The uranium concentrations ranged from 0.03 to 42.7 micrograms per liter. One sample was analyzed for carbon-14, and the amount of modern atmospheric carbon was reported as 0.2 percent. Six source-water samples collected from municipal supply wells were analyzed for radium-226, and all of the concentrations were considered detectable concentrations (greater than their associated sample-specific critical level). Three source-water samples collected were analyzed for radon-222, and all of the concentrations were substantially greater than the associated sample-specific critical level.

Decrease in early right alpha band phase synchronization and late gamma band oscillations in processing syntax in music.

PubMed

Ruiz, María Herrojo; Koelsch, Stefan; Bhattacharya, Joydeep

2009-04-01

The present study investigated the neural correlates associated with the processing of music-syntactical irregularities as compared with regular syntactic structures in music. Previous studies reported an early ( approximately 200 ms) right anterior negative component (ERAN) by traditional event-related-potential analysis during music-syntactical irregularities, yet little is known about the underlying oscillatory and synchronization properties of brain responses which are supposed to play a crucial role in general cognition including music perception. First we showed that the ERAN was primarily represented by low frequency (<8 Hz) brain oscillations. Further, we found that music-syntactical irregularities as compared with music-syntactical regularities, were associated with (i) an early decrease in the alpha band (9-10 Hz) phase synchronization between right fronto-central and left temporal brain regions, and (ii) a late ( approximately 500 ms) decrease in gamma band (38-50 Hz) oscillations over fronto-central brain regions. These results indicate a weaker degree of long-range integration when the musical expectancy is violated. In summary, our results reveal neural mechanisms of music-syntactic processing that operate at different levels of cortical integration, ranging from early decrease in long-range alpha phase synchronization to late local gamma oscillations. 2008 Wiley-Liss, Inc.

Heart rate dynamics in patients with stable angina pectoris and utility of fractal and complexity measures

NASA Technical Reports Server (NTRS)

Makikallio, T. H.; Ristimae, T.; Airaksinen, K. E.; Peng, C. K.; Goldberger, A. L.; Huikuri, H. V.

1998-01-01

Dynamic analysis techniques may uncover abnormalities in heart rate (HR) behavior that are not easily detectable with conventional statistical measures. However, the applicability of these new methods for detecting possible abnormalities in HR behavior in various cardiovascular disorders is not well established. Conventional measures of HR variability were compared with short-term (< or = 11 beats, alpha1) and long-term (> 11 beats, alpha2) fractal correlation properties and with approximate entropy of RR interval data in 38 patients with stable angina pectoris without previous myocardial infarction or cardiac medication at the time of the study and 38 age-matched healthy controls. The short- and long-term fractal scaling exponents (alpha1, alpha2) were significantly higher in the coronary patients than in the healthy controls (1.34 +/- 0.15 vs 1.11 +/- 0.12 [p <0.001] and 1.10 +/- 0.08 vs 1.04 +/- 0.06 [p <0.01], respectively), and they also had lower approximate entropy (p <0.05), standard deviation of all RR intervals (p <0.01), and high-frequency spectral component of HR variability (p <0.05). The short-term fractal scaling exponent performed better than other heart rate variability parameters in differentiating patients with coronary artery disease from healthy subjects, but it was not related to the clinical or angiographic severity of coronary artery disease or any single nonspectral or spectral measure of HR variability in this retrospective study. Patients with stable angina pectoris have altered fractal properties and reduced complexity in their RR interval dynamics relative to age-matched healthy subjects. Dynamic analysis may complement traditional analyses in detecting altered HR behavior in patients with stable angina pectoris.

The Cambridge-Cambridge x-ray serendipity survey. 2: Classification of x-ray luminous galaxies

NASA Technical Reports Server (NTRS)

Boyle, B. J.; Mcmahon, R. G.; Wilkes, B. J.; Elvis, Martin

1994-01-01

We present the results of an intermediate-resolution (1.5 A) spectroscopic study of 17 x-ray luminous narrow emission-line galaxies previously identified in the Cambridge-Cambridge ROSAT Serendipity Survey and the Einstein Extended Medium Sensitivity Survey. Emission-line ratios reveal that the sample is composed of ten Seyfert and seven starburst galaxies. Measured linewidths for the narrow H alpha emission lines lie in the range 170 - 460 km s(exp -1). Five of the objects show clear evidence for asymmetry in the (OIII) lambda 5007 emission-line profile. Broad H alpha emission is detected in six of the Seyfert galaxies, which range in type from Seyfert 1.5 to 2. Broad H beta emission is only detected in one Seyfert galaxy. The mean full width at half maximum for the broad lines in the Seyfert galaxies is FWHM = 3900 +/- 1750 km s(exp -1). Broad (FWHM = 2200 +/- 600 km s(exp -1) H alpha emission is also detected in three of the starburst galaxies, which could originate from stellar winds or supernovae remnants. The mean Balmer decrement for the sample is H alpha / H beta = 3, consistent with little or no reddening for the bulk of the sample. There is no evidence for any trend with x-ray luminosity in the ratio of starburst galaxies to Seyfert galaxies. Based on our previous observations, it is therefore likely that both classes of object comprise approximately 10 percent of the 2 keV x-ray background.

Analysis of residual products in benzyl chloride used for the industrial synthesis of quaternary compounds by liquid chromatography with diode-array detection.

PubMed

Prieto-Blanco, M C; López-Mahía, P; Prada-Rodríguez, D

2009-02-01

In industrial and pharmaceutical processes, the study of residual products becomes essential to guarantee the quality of compounds and to eliminate or minimize toxic residual products. Knowledge about the origin of impurities (raw materials, processes, the contamination of industrial plants, etc.) is necessary in preventive treatment and in the control of a product's lifecycle. Benzyl chloride is used as raw material to synthesize several quaternary ammonium compounds, such as benzalkonium chloride, which may have pharmaceutical applications. Benzaldehyde, benzyl alcohol, toluene, chloro derivatives of toluene, and dibenzyl ether are compounds that may be found as impurities in technical benzyl chloride. We proposed a high-performance liquid chromatography method for the separation of these compounds, testing two stationary phases with different dimensions and particle sizes, with the application of photodiode array-detection. The linearity for four possible impurities (benzaldehyde, toluene, alpha,alpha-dichlorotoluene, and 2-chlorotoluene) ranged from 0.1 to 10 microg/mL, limits of detection from 11 to 34 ng/mL, and repeatability from 1% to 2.9% for a 0.3-1.2 microg/mL concentration range. The method was applied to samples of technical benzyl chloride, and alpha,alpha-dichlorotoluene and benzaldehyde were identified by spectral analysis and quantitated. The selection of benzyl chloride with lower levels of impurities is important to guarantee the reduction of residual products in further syntheses.

Electronic Properties of DNA-Based Schottky Barrier Diodes in Response to Alpha Particles.

PubMed

Al-Ta'ii, Hassan Maktuff Jaber; Periasamy, Vengadesh; Amin, Yusoff Mohd

2015-05-21

Detection of nuclear radiation such as alpha particles has become an important field of research in recent history due to nuclear threats and accidents. In this context; deoxyribonucleic acid (DNA) acting as an organic semiconducting material could be utilized in a metal/semiconductor Schottky junction for detecting alpha particles. In this work we demonstrate for the first time the effect of alpha irradiation on an Al/DNA/p-Si/Al Schottky diode by investigating its current-voltage characteristics. The diodes were exposed for different periods (0-20 min) of irradiation. Various diode parameters such as ideality factor, barrier height, series resistance, Richardson constant and saturation current were then determined using conventional, Cheung and Cheung's and Norde methods. Generally, ideality factor or n values were observed to be greater than unity, which indicates the influence of some other current transport mechanism besides thermionic processes. Results indicated ideality factor variation between 9.97 and 9.57 for irradiation times between the ranges 0 to 20 min. Increase in the series resistance with increase in irradiation time was also observed when calculated using conventional and Cheung and Cheung's methods. These responses demonstrate that changes in the electrical characteristics of the metal-semiconductor-metal diode could be further utilized as sensing elements to detect alpha particles.

Assessing the dependency of the fine structure constant on gravity using hot DA white dwarfs

NASA Astrophysics Data System (ADS)

Barstow, Martin

2016-10-01

Variation of fundamental constants is a common theme of many theories of quantum gravity and Grand Unification. Using spectra obtained with the Hubble Space Telescope, it has been shown by Berengut et al. (2013), and Bagdonaite et al. (2014), that it is possible to place strong constraints on gravitational variations of the fine structure constant (alpha), and the proton to electron mass ratio (mu) in white dwarf stars.As part of the UV initiative, we propose to observe four hot DA white dwarf stars using STIS with the E140H grating, totalling 12 orbits. These four stars have been chosen so as to have a wide range of masses, allowing a full exploration of the compactness parameter space (M/R). We will measure several absorption features of Fe V and Ni V, and extract any potential variation in alpha in a manner similar to Berengut et al. (2013).This proposal will be a significant advance in the effort to detect gravitational variations in alpha. A confirmed detection of alpha variation would have extensive consequences for fundamental physics, cosmology, and would also signal the breakdown of Einstein's Equivalence principle, and hence, general relativity. Furthermore, a null detection would also allow strong limits to be placed on any potential alpha variation in a strong gravitational field.

Time-averaged exposures to 220Rn and 222Rn progeny in Colorado homes.

PubMed

Martz, D E; Falco, R J; Langner, G H

1990-06-01

Week-long time-averaged exposures to naturally occurring 220Rn and 222Rn progeny have been measured at several locations in Colorado by monitoring the alpha activity collected continuously on a fixed-membrane filter. The alpha-energy spectrum associated with the activity collected on the filter was recorded every 15 min using a microcomputer-controlled alpha spectrometer. The alpha counts observed in three energy regions permitted complete separation of the contributions from each decay chain, and calculation of the separate time-averaged potential alpha-energy concentrations in air from 220Rn progeny, PAEC(Tn), and from 222Rn progeny, PAEC(Rn). The time-averaged PAEC(Tn) ranged from 0.3 to 6.9 mWL at 12 indoor locations, and the time-averaged PAEC(Rn) ranged from 1.0 to 59.0 mWL. The ratios of the indoor PAEC(Tn) to indoor PAEC(Rn) ranged from 0.09 to 0.58, with an overall average ratio of 0.32 and a standard deviation of 0.15. The 10 L min-1 flow rate through the filter was selected to approximate the air intake rate of a resting human; the time-averaged PAEC thus represents the progeny concentrations that would have been inhaled by a person breathing the same atmosphere.

Tuning the effective fine structure constant in graphene: opposing effects of dielectric screening on short- and long-range potential scattering.

PubMed

Jang, C; Adam, S; Chen, J-H; Williams, E D; Das Sarma, S; Fuhrer, M S

2008-10-03

We reduce the dimensionless interaction strength alpha in graphene by adding a water overlayer in ultrahigh vacuum, thereby increasing dielectric screening. The mobility limited by long-range impurity scattering is increased over 30%, due to the background dielectric constant enhancement leading to a reduced interaction of electrons with charged impurities. However, the carrier-density-independent conductivity due to short-range impurities is decreased by almost 40%, due to reduced screening of the impurity potential by conduction electrons. The minimum conductivity is nearly unchanged, due to canceling contributions from the electron-hole puddle density and long-range impurity mobility. Experimental data are compared with theoretical predictions with excellent agreement.

Actin Filaments and Myosin I Alpha Cooperate with Microtubules for the Movement of LysosomesV⃞

PubMed Central

Cordonnier, Marie-Neige; Dauzonne, Daniel; Louvard, Daniel; Coudrier, Evelyne

2001-01-01

An earlier report suggested that actin and myosin I alpha (MMIα), a myosin associated with endosomes and lysosomes, were involved in the delivery of internalized molecules to lysosomes. To determine whether actin and MMIα were involved in the movement of lysosomes, we analyzed by time-lapse video microscopy the dynamic of lysosomes in living mouse hepatoma cells (BWTG3 cells), producing green fluorescent protein actin or a nonfunctional domain of MMIα. In GFP-actin cells, lysosomes displayed a combination of rapid long-range directional movements dependent on microtubules, short random movements, and pauses, sometimes on actin filaments. We showed that the inhibition of the dynamics of actin filaments by cytochalasin D increased pauses of lysosomes on actin structures, while depolymerization of actin filaments using latrunculin A increased the mobility of lysosomes but impaired the directionality of their long-range movements. The production of a nonfunctional domain of MMIα impaired the intracellular distribution of lysosomes and the directionality of their long-range movements. Altogether, our observations indicate for the first time that both actin filaments and MMIα contribute to the movement of lysosomes in cooperation with microtubules and their associated molecular motors. PMID:11739797

Innovative procedure for the determination of gross-alpha/gross-beta activities in drinking water.

PubMed

Wisser, S; Frenzel, E; Dittmer, M

2006-03-01

An alternative sample preparation method for the determination of gross-alpha/beta activity concentrations in drinking water is introduced in this paper. After the freeze-drying of tap water samples, determination by liquid scintillation counting can be applied utilizing alpha/beta separation. It has been shown that there is no adsorption or loss of solid radionuclides during the freeze-drying procedure. However, the samples have to be measured quickly after the preparation since the ingrowth of daughter isotopes negatively effects the measurement. The limits of detection for gross-alpha and gross-beta activity are in the range 25-210 mBq/l, respectively, for a measurement time of only 8-9 h.

Detection of alpha-fetoprotein in magnetic immunoassay of thin channels using biofunctional nanoparticles

NASA Astrophysics Data System (ADS)

Tsai, H. Y.; Gao, B. Z.; Yang, S. F.; Li, C. S.; Fuh, C. Bor

2014-01-01

This paper presents the use of fluorescent biofunctional nanoparticles (10-30 nm) to detect alpha-fetoprotein (AFP) in a thin-channel magnetic immunoassay. We used an AFP model biomarker and s-shaped deposition zones to test the proposed detection method. The results show that the detection using fluorescent biofunctional nanoparticle has a higher throughput than that of functional microparticle used in previous experiments on affinity reactions. The proposed method takes about 3 min (versus 150 min of previous method) to detect 100 samples. The proposed method is useful for screening biomarkers in clinical applications, and can reduce the run time for sandwich immunoassays to less than 20 min. The detection limits (0.06 pg/ml) and linear ranges (0.068 pg/ml-0.68 ng/ml) of AFP using fluorescent biofunctional nanoparticles are the same as those of using functional microparticles within experimental errors. This detection limit is substantially lower and the linear range is considerably wider than those of enzyme-linked immunosorbent assay (ELISA) and other methods in sandwich immunoassay methods. The differences between this method and an ELISA in AFP measurements of serum samples were less than 12 %. The proposed method provides simple, fast, and sensitive detection with a high throughput for biomarkers.

Fast retrospective determination of radon exposure with a sensitive alpha scintillation probe.

PubMed

von Philipsborn, Henning; Just, Günther

2005-09-01

The background of a hand-held alpha ZnS scintillation probe of 44 cm(2) was reduced from the normal 50 counts per hour (cph) to 4 +/- 2 cph and the efficiency increased to 34%. The limit of detection for a 30 min measurement is now 5 Bq m(-2) Po-210 on glass surfaces, corresponding to about 200 Bq m(-3) indoor Rn-222 exposure for 20 years. The probe was successfully used for retrospective determination of radon exposure. The probe is simpler, faster and more convenient, and more economic than alpha spectrometry or nuclear track detectors currently used in the field of lung cancer epidemiology and long term radon exposure.

Procedure for the determination of retinol and alpha-tocopherol in poultry tissues using capillary gas chromatography with solvent venting injection.

PubMed

Maraschiello, C; García Regueiro, J A

1998-08-28

A procedure designed for the determination of retinol (vitamin A) and alpha-tocopherol (vitamin E) in poultry tissues has been developed. The procedure involves lipid extraction, saponification, solid-phase clean-up and capillary gas chromatography (cGC). Retinol and alpha-tocopherol were determined separately by cGC-flame ionisation detection using a fused-silica open tubular capillary column, 30 m x 0.25 mm I.D. coated with 5% phenylmethylsilicone and with a film thickness of 0.25 micron. Solvent extraction followed by saponification were sufficient to provide a purified extract which was directly analyzed for retinol by cGC in the solvent venting mode. However, in order to accurately determine alpha-tocopherol by cGC, further purification of the extract by solid-phase extraction was necessary. A silica SPE column was used to remove interfering cholesterol from the extract. alpha-Tocopherol was analyzed in its derivatized form. Absolute and relative recoveries for both vitamins from spiked samples were evaluated. Absolute and relative recoveries ranging from 80 to 95% were obtained for both compounds. 5 alpha-Cholestane and alpha-tocopheryl acetate were used as internal standards. Poultry muscle meat and liver tissue were analyzed for their retinol and alpha-tocopherol content and the peaks detected by cGC were confirmed by cGC-mass spectrometry.

Natural radionuclides in waste water discharged from coal-fired power plants in Serbia.

PubMed

Janković, Marija M; Todorović, Dragana J; Sarap, Nataša B; Krneta Nikolić, Jelena D; Rajačić, Milica M; Pantelić, Gordana K

2016-12-01

Investigation of the natural radioactivity levels in water around power plants, as well as in plants, coal, ash, slag and soil, and to assess the associated radiation hazard is becoming an emerging and interesting topic. This paper is focused on the results of the radioactivity analysis in waste water samples from five coal-fired power plants in Serbia (Nikola Tesla A, Nikola Tesla B, Kolubara, Morava and Kostolac), which were analyzed in the period 2003-2015. River water samples taken upstream and downstream from the power plants, drain water and overflow water were analyzed. In the water samples gamma spectrometry analysis was performed as well as determination of gross alpha and beta activity. Natural radionuclide 40 K was detected by gamma spectrometry, while the concentrations of other radionuclides, 226 Ra, 235 U and 238 U, usually were below the minimum detection activity (MDA). 232 Th and artificial radionuclide 137 Cs were not detected in these samples. Gross alpha and beta activities were determined by the α/β low level proportional counter Thermo Eberline FHT 770 T. In the analyzed samples, gross alpha activity ranged from MDA to 0.47 Bq L - 1 , while the gross beta activity ranged from MDA to 1.55 Bq L - 1 .

Far-Infrared and Millimeter Continuum Studies of K-Giants: Alpha Boo and Alpha Tau

NASA Technical Reports Server (NTRS)

Cohen, Martin; Carbon, Duane F.; Welch, William J.; Lim, Tanya; Forster, James R.; Goorvitch, David; Thigpen, William (Technical Monitor)

2002-01-01

We have imaged two normal, non-coronal, infrared-bright K-giants, alpha Boo and alpha Tau, in the 1.4-millimeter and 2.8-millimeter continuum using BIMA. These stars have been used as important absolute calibrators for several infrared satellites. Our goals are: (1) to probe the structure of their upper photospheres; (2) to establish whether these stars radiate as simple photospheres or possess long-wavelength chromospheres; and (3) to make a connection between millimeter-wave and far-infrared absolute flux calibrations. To accomplish these goals we also present ISO Long Wavelength Spectrometer (LWS) measurements of both these K-giants. The far-infrared and millimeter continuum radiation is produced in the vicinity of the temperature minimum in a Boo and a Tau, offering a direct test of the model photospheres and chromospheres for these two cool giants. We find that current photospheric models predict fluxes in reasonable agreement with those observed for those wavelengths which sample the upper photosphere, namely less than or equal to 170 micrometers in alpha Tau and less than or equal to 125 micrometers in alpha Boo. It is possible that alpha Tau is still radiative as far as 0.9 - 1.4 millimeters. We detect chromospheric radiation from both stars by 2.8 millimeters (by 1.4 millimeters in alpha Boo), and are able to establish useful bounds on the location of the temperature minimum. An attempt to interpret the chromospheric fluxes using the two-component "bifurcation model" proposed by Wiedemann et al. (1994) appears to lead to a significant contradiction.

Luminescence imaging of water during alpha particle irradiation

NASA Astrophysics Data System (ADS)

Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Toshito, Toshiyuki

2016-05-01

The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of 241Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

Determination of gross alpha and gross beta in soil around repository facility at Bukit Kledang, Perak, Malaysia

NASA Astrophysics Data System (ADS)

Adziz, Mohd Izwan Abdul; Siong, Khoo Kok

2018-04-01

Recently, the Long Term Storage Facility (LTSF) in Bukit Kledang, Perak, Malaysia, has been upgraded to repository facility upon the completion of decontamination and decommissioning (D&D) process. Thorium waste and contaminated material that may contain some minor amounts of thorium hydroxide were disposed in this facility. This study is conducted to determine the concentrations of gross alpha and gross beta radioactivities in soil samples collected around the repository facility. A total of 12 soil samples were collected consisting 10 samples from around the facility and 2 samples from selected residential area near the facility. In addition, the respective dose rates were measured 5 cm and 1 m above the ground by using survey meter with Geiger Muller (GM) detector and Sodium Iodide (NaI) detector. Soil samples were collected using hand auger and then were taken back to the laboratory for further analysis. Samples were cleaned, dried, pulverized and sieved prior to analysis. Gross alpha and gross beta activity measurements were carried out using gas flow proportional counter, Canberra Series 5 XLB - Automatic Low Background Alpha and Beta Counting System. The obtained results show that, the gross alpha and gross beta activity concentration ranged from 1.55 to 5.34 Bq/g with a mean value of 3.47 ± 0.09 Bq/g and 1.64 to 5.78 Bq/g with a mean value of 3.49 ± 0.09 Bq/g, respectively. These results can be used as an additional data to represent terrestrial radioactivity baseline data for Malaysia environment. This estimation will also serve as baseline for detection of any future related activities of contamination especially around the repository facility area.

Changes in Alpha Frequency and Power of the Electroencephalogram during Volatile-Based General Anesthesia.

PubMed

Hight, Darren; Voss, Logan J; Garcia, Paul S; Sleigh, Jamie

2017-01-01

Oscillations in the electroencephalogram (EEG) at the alpha frequency (8-12 Hz) are thought to be ubiquitous during surgical anesthesia, but the details of how this oscillation responds to ongoing changes in volatile anesthetic concentration have not been well characterized. It is not known how often alpha oscillations are absent in the clinical context, how sensitively alpha frequency and power respond to changes in anesthetic concentration, and what effect increased age has on alpha frequency. Bipolar EEG was recorded frontally from 305 patients undergoing surgery with sevoflurane or desflurane providing general anesthesia. A new method of detecting the presence of alpha oscillations based on the stability of the rate of change of the peak frequency in the alpha range was developed. Linear concentration-response curves were fitted to assess the sensitivity of alpha power and frequency measures to changing levels of anesthesia. Alpha oscillations were seen to be inexplicably absent in around 4% of patients. Maximal alpha power increased with increasing volatile anesthetic concentrations in half of the patients, and decreased in the remaining patients. Alpha frequency decreased with increasing anesthetic concentrations in near to 90% of patients. Increasing age was associated with decreased sensitivity to volatile anesthesia concentrations, and with decreased alpha frequency, which sometimes transitioned into the theta range (5-7 Hz). While peak alpha frequency shows a consistent slowing to increasing volatile concentrations, the peak power of the oscillation does not, suggesting that frequency might be more informative of depth of anesthesia than traditional power based measures during volatile-based anesthesia. The alpha oscillation becomes slower with increasing age, even when the decreased anesthetic needs of older patients were taken into account.

The Fabrication and Characterization of Ni/4H-SiC Schottky Diode Radiation Detectors with a Sensitive Area of up to 4 cm².

PubMed

Liu, Lin-Yue; Wang, Ling; Jin, Peng; Liu, Jin-Liang; Zhang, Xian-Peng; Chen, Liang; Zhang, Jiang-Fu; Ouyang, Xiao-Ping; Liu, Ao; Huang, Run-Hua; Bai, Song

2017-10-13

Silicon carbide (SiC) detectors of an Ni/4H-SiC Schottky diode structure and with sensitive areas of 1-4 cm² were fabricated using high-quality lightly doped epitaxial 4H-SiC material, and were tested in the detection of alpha particles and pulsed X-rays/UV-light. A linear energy response to alpha particles ranging from 5.157 to 5.805 MeV was obtained. The detectors were proved to have a low dark current, a good energy resolution, and a high neutron/gamma discrimination for pulsed radiation, showing the advantages in charged particle detection and neutron detection in high-temperature and high-radiation environments.

The solar-flare infrared continuum - Observational techniques and upper limits

NASA Technical Reports Server (NTRS)

Hudson, H. S.

1975-01-01

Exploratory observations at 20 microns and 350 microns have determined detection thresholds for solar flares in these wavelengths. In the 20-micron range, solar atmospheric fluctuations (the 'temperature field') set the basic limits on flare detectability at about 5 K; at 350 microns, extinction in the earth's atmosphere provides the basic limitation of about 30 K. These thresholds are low enough for the successful detection of several infrared-emitting components of large flares. The upper limits obtained for subflares indicate that the thickness of the H-alpha flare region does not exceed approximately 10 km. This result confirms the conclusion of Suemoto and Hiei (1959) regarding the small effective thickness of the H-alpha-emitting regions in solar flares.

Functional connectivity changes detected with magnetoencephalography after mild traumatic brain injury

PubMed Central

Dimitriadis, Stavros I.; Zouridakis, George; Rezaie, Roozbeh; Babajani-Feremi, Abbas; Papanicolaou, Andrew C.

2015-01-01

Mild traumatic brain injury (mTBI) may affect normal cognition and behavior by disrupting the functional connectivity networks that mediate efficient communication among brain regions. In this study, we analyzed brain connectivity profiles from resting state Magnetoencephalographic (MEG) recordings obtained from 31 mTBI patients and 55 normal controls. We used phase-locking value estimates to compute functional connectivity graphs to quantify frequency-specific couplings between sensors at various frequency bands. Overall, normal controls showed a dense network of strong local connections and a limited number of long-range connections that accounted for approximately 20% of all connections, whereas mTBI patients showed networks characterized by weak local connections and strong long-range connections that accounted for more than 60% of all connections. Comparison of the two distinct general patterns at different frequencies using a tensor representation for the connectivity graphs and tensor subspace analysis for optimal feature extraction showed that mTBI patients could be separated from normal controls with 100% classification accuracy in the alpha band. These encouraging findings support the hypothesis that MEG-based functional connectivity patterns may be used as biomarkers that can provide more accurate diagnoses, help guide treatment, and monitor effectiveness of intervention in mTBI. PMID:26640764

A cog in cognition: how the alpha 7 nicotinic acetylcholine receptor is geared towards improving cognitive deficits.

PubMed

Leiser, Steven C; Bowlby, Mark R; Comery, Thomas A; Dunlop, John

2009-06-01

Cognition, memory, and attention and arousal have been linked to nicotinic acetylcholine receptors (nAChRs). Thus it is not surprising that nAChRs have been strongly implicated as therapeutic targets for treating cognitive deficits in disorders such as schizophrenia and Alzheimer's disease (AD). In particular the alpha7 (alpha7) nAChR has been closely linked with normalization of P50 auditory evoked potential (AEP) gating deficits, and to a lesser extent improvements in pre-pulse inhibition (PPI) of the acoustic startle response. These two brain phenomena can be considered as pre-attentive, occurring while sensory information is being processed, and are important endophenotypes in schizophrenia with deficits likely contributing to the cognitive fragmentation associated with the disease. In addition alpha7 nAChRs have been implicated in attention, in particular under high attentional demand, and in more demanding working memory tasks such as long delays in delayed matching tasks. Efficacy of alpha7 nAChR agonists across a range of cognitive processes ranging from pre-attentive to attentive states and working and recognition memory provides a solid basis for their pro-cognitive effects. This review will focus on the recent work highlighting the role of alpha7 in cognition and cognitive processes.

Predicting the Redshift 2 H-Alpha Luminosity Function Using [OIII] Emission Line Galaxies

NASA Technical Reports Server (NTRS)

Mehta, Vihang; Scarlata, Claudia; Colbert, James W.; Dai, Y. S.; Dressler, Alan; Henry, Alaina; Malkan, Matt; Rafelski, Marc; Siana, Brian; Teplitz, Harry I.;

Copernicus measurement of the Jovian Lyman-alpha emission and its aeronomical significance

NASA Technical Reports Server (NTRS)

Atreya, S. K.; Kerr, R. B.; Upson, W. L., II; Festou, M. C.; Donahue, T. M.; Barker, E. S.; Cochran, W. D.; Bertaux, J. L.

1982-01-01

It is pointed out that the intensity of the Lyman-alpha emission is a good indicator of the principal aeronomical processes on the major planets. The high-resolution ultraviolet spectrometer aboard the Orbiting Astronomical Observatory Copernicus was used in 1980 April and May to detect the Jovian Lyman-alpha emission by spectroscopically discriminating it from other Doppler shifted Lyman-alpha emissions such as those of the geocorona, and the interplanetary medium. Taking into consideration the reported emission data, it appears that an unusually large energy input due to the particle precipitation in the auroral region must have been responsible for the large observed Lyman-alpha intensity during the Voyager encounter. At most other times, the observed Jovian Lyman-alpha intensity can be explained, within the range of statistical uncertainty, by a model that takes into consideration the solar EUV flux, the solar Lyman-alpha flux, the high exospheric temperature, and the eddy diffusion coefficient without energy input from the auroral sources.

Dose-equivalent neutron dosimeter

DOEpatents

Griffith, R.V.; Hankins, D.E.; Tomasino, L.; Gomaa, M.A.M.

1981-01-07

A neutron dosimeter is disclosed which provides a single measurement indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer contaning conversion material such as /sup 6/Li and /sup 10/B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet.

Improving the limits of detection of low background alpha emission measurements

NASA Astrophysics Data System (ADS)

McNally, Brendan D.; Coleman, Stuart; Harris, Jack T.; Warburton, William K.

2018-01-01

Alpha particle emission - even at extremely low levels - is a significant issue in the search for rare events (e.g., double beta decay, dark matter detection). Traditional measurement techniques require long counting times to measure low sample rates in the presence of much larger instrumental backgrounds. To address this, a commercially available instrument developed by XIA uses pulse shape analysis to discriminate alpha emissions produced by the sample from those produced by other surfaces of the instrument itself. Experience with this system has uncovered two residual sources of background: cosmogenics and radon emanation from internal components. An R&D program is underway to enhance the system and extend the pulse shape analysis technique further, so that these residual sources can be identified and rejected as well. In this paper, we review the theory of operation and pulse shape analysis techniques used in XIA's alpha counter, and briefly explore data suggesting the origin of the residual background terms. We will then present our approach to enhance the system's ability to identify and reject these terms. Finally, we will describe a prototype system that incorporates our concepts and demonstrates their feasibility.

Relationships Between Long-Range Lightning Networks and TRMM/LIS Observations

NASA Technical Reports Server (NTRS)

Rudlosky, Scott D.; Holzworth, Robert H.; Carey, Lawrence D.; Schultz, Chris J.; Bateman, Monte; Cummins, Kenneth L.; Cummins, Kenneth L.; Blakeslee, Richard J.; Goodman, Steven J.

2012-01-01

Recent advances in long-range lightning detection technologies have improved our understanding of thunderstorm evolution in the data sparse oceanic regions. Although the expansion and improvement of long-range lightning datasets have increased their applicability, these applications (e.g., data assimilation, atmospheric chemistry, and aviation weather hazards) require knowledge of the network detection capabilities. The present study intercompares long-range lightning data with observations from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite. The study examines network detection efficiency and location accuracy relative to LIS observations, describes spatial variability in these performance metrics, and documents the characteristics of LIS flashes that are detected by the long-range networks. Improved knowledge of relationships between these datasets will allow researchers, algorithm developers, and operational users to better prepare for the spatial and temporal coverage of the upcoming GOES-R Geostationary Lightning Mapper (GLM).

A survey on uncertainty in bioassay measurements carried out within the OMINEX project.

PubMed

Hurtgen, C; Cossonnet, C

2003-01-01

One of the topics covered by the OMINEX (Optimisation of Monitoring for Internal Exposure) project was to look at the bioassay measurements performed in the European laboratories. Questionnaires on bioassay measurements by alpha spectrometry or inductively coupled plasma-mass spectrometry (ICP-MS) were sent to European laboratories. The main objective was to collect information on analytical procedures and on the uncertainties associated with bioassay results. Alpha spectrometry is the technique most often used for the determination of alpha emitters, such as actinides in biological samples. ICP-MS is not used much as yet for routine measurements of actinides in biological samples, but is very sensitive for measurements of long-lived radionuclides. The different parameters influencing the uncertainties on the results and the minimum detectable amount have been investigated. Optimum conditions for achieving low result uncertainties and high sensitivity are given for alpha spectrometry and ICP-MS.

Prevalence of -alpha(3.7) and alpha alpha alpha(anti3.7) alleles in sickle cell trait and beta-thalassemia patients in Mexico.

PubMed

Nava, María Paulina; Ibarra, Bertha; Magaña, María Teresa; de la Luz Chávez, María; Perea, F Javier

2006-01-01

The aim of this study was to determine the frequency of alpha-globin gene mutations in three groups of Mexican unrelated individuals. The first two groups were normal and sickle cell trait individuals from the Costa Chica region, a place with a 12.8% frequency of HbS carriers, and the third group comprised of Mexican mestizo patients with beta-thalassemia. We searched for -alpha(3.7) and -alpha(4.2) alpha(+)-thalassemia deletion alleles, as well as the alpha alpha alpha(anti3.7) triplication through long-gap PCR. The alleles -alpha(3.7) and alpha alpha alpha(anti3.7) were found in the heterozygote state only; 19% of the normal subjects had the -alpha(3.7) allele, and 2% showed the alpha alpha alpha(anti3.7) allele. In individuals with the sickle cell trait, 17% had the -alpha(3.7) deletion, and the alpha alpha alpha(anti3.7) triplication was observed in 3% of these individuals. We revealed that 16% of the subjects with beta-thalassemia showed the -alpha(3.7) deletion and 28% the alpha alpha alpha(anti3.7) triplication. The -alpha(4.2) deletion was not detected in any individual. The frequency of the -alpha(3.7) allele was roughly the same in the three groups studied; this can be explained by the fact that the three groups have common genes from Africa and the Mediterranean, where a high prevalence of alpha(+)-thalassemia has been observed. To our knowledge, the frequency of alpha alpha alpha(anti3.7) triplication observed in the Mexican beta-thalassemia patients is the highest reported. As the -alpha(3.7) and alpha alpha alpha(anti3.7) alleles are very common in our selected populations, we believe that there is a need to investigate systematically the alpha-globin gene mutations in all hemoglobinopathies in the Mexican population.

Modeling the effect of snow and ice on the global environmental fate and long-range transport potential of semivolatile organic compounds.

PubMed

Stocker, Judith; Scheringer, Martin; Wegmann, Fabio; Hungerbuhler, Konrad

2007-09-01

Snow and ice have been implemented in a global multimedia box model to investigate the influence of these media on the environmental fate and long-range transport (LRT) of semivolatile organic compounds (SOCs). Investigated compounds include HCB, PCB28, PCB180, PBDE47, PBDE209, alpha-HCH, and dacthal. In low latitudes, snow acts as a transfer medium taking up chemicals from air and releasing them to water or soil during snowmelt. In high latitudes, snow and ice shield water, soil, and vegetation from chemical deposition. In the model version including snow and ice (scenario 2), the mass of chemicals in soil in high latitudes is between 27% (HCB) and 97% (alpha-HCH) of the mass calculated with the model version without snow and ice (scenario 1). Amounts in Arctic seawater in scenario 2 are 8% (alpha-HCH) to 21% (dacthal) of the amounts obtained in scenario 1. For all investigated chemicals except alpha-HCH, presence of snow and ice in the model increases the concentration in air by a factor of 2 (HCB)to 10 (PBDE209). Because of reduced net deposition to snow-covered surfaces in high latitudes, LRT to the Arctic is reduced for most chemicals whereas transport to the south is more pronounced than in scenario 1 ("southward shift"). The presence of snow and ice thus considerably changes the environmental fate of SOCs.

Standoff alpha radiation detection for hot cell imaging and crime scene investigation

NASA Astrophysics Data System (ADS)

Kerst, Thomas; Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Nicholl, Adrian; Hrnecek, Erich; Toivonen, Harri; Toivonen, Juha

2018-02-01

This paper presents the remote detection of alpha contamination in a nuclear facility. Alpha-active material in a shielded nuclear radiation containment chamber has been localized by optical means. Furthermore, sources of radiation danger have been identified in a staged crime scene setting. For this purpose, an electron-multiplying charge-coupled device camera was used to capture photons generated by alpha-induced air scintillation (radioluminescence). The detected radioluminescence was superimposed with a regular photograph to reveal the origin of the light and thereby the alpha radioactive material. The experimental results show that standoff detection of alpha contamination is a viable tool in radiation threat detection. Furthermore, the radioluminescence spectrum in the air is spectrally analyzed. Possibilities of camera-based alpha threat detection under various background lighting conditions are discussed.

Standoff alpha radiation detection for hot cell imaging and crime scene investigation

NASA Astrophysics Data System (ADS)

Kerst, Thomas; Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Nicholl, Adrian; Hrnecek, Erich; Toivonen, Harri; Toivonen, Juha

2018-06-01

This paper presents the remote detection of alpha contamination in a nuclear facility. Alpha-active material in a shielded nuclear radiation containment chamber has been localized by optical means. Furthermore, sources of radiation danger have been identified in a staged crime scene setting. For this purpose, an electron-multiplying charge-coupled device camera was used to capture photons generated by alpha-induced air scintillation (radioluminescence). The detected radioluminescence was superimposed with a regular photograph to reveal the origin of the light and thereby the alpha radioactive material. The experimental results show that standoff detection of alpha contamination is a viable tool in radiation threat detection. Furthermore, the radioluminescence spectrum in the air is spectrally analyzed. Possibilities of camera-based alpha threat detection under various background lighting conditions are discussed.

Quantitative detection of liver-relevant biomarkers by SERS-immunolabeled gold nanoparticles

NASA Astrophysics Data System (ADS)

Payne, William Mark

Lab-on-a-chip technology has the potential to rapidly change the way experiments are conducted in a variety of fields ranging from medicine to environmental science. Specifically, sensors, detectors, and monitoring devices are increasingly being miniaturized to perform many experiments or measurements on a single chip. In this research, we develop an immunolabeled gold nanoparticle complex capable of detecting liver organoid biomarkers intended for use in a microfluidic device. Human Serum Albumin (HSA) and alpha-Glutathione S-Transferase (alpha-GST) are liver biomarkers that indicate liver health and damage respectively. Herein we demonstrate detection of the liver organoid biomarkers at nanomolar concentrations. Through plasmonic coupling induced by aggregation in the presence of analyte, the SERS signal obtained from the nanoparticles is dramatically increased. Furthermore, detection is demonstrated in a simple fluidic device to show the feasibility of implementing an optimized SERS-immunolabeled nanoparticle for translational application.

Alpha-fetoprotein detection by using a localized surface plasmon coupled fluorescence fiber-optic biosensor

NASA Astrophysics Data System (ADS)

Chang, Ying-Feng; Chen, Ran-Chou; Li, Ying-Chang; Yu, Chih-Jen; Hsieh, Bao-Yu; Chou, Chien

2007-11-01

Alpha-fetoprotein (AFP) detection by using a localized surface plasmon coupled fluorescence (LSPCF) fiber-optic biosensor is setup and experimentally demonstrated. It is based on gold nanoparticle (GNP) and coupled with localized surface plasmon wave on the surface of GNP. In this experiment, the fluorophores are labeled on anti-AFP which are bound to protein A conjugated GNP. Thus, LSPCF is excited with high efficiency in the near field of localized surface plasmon wave. Therefore, not only the sensitivity of LSPCF biosensor is enhanced but also the specific selectivity of AFP is improved. Experimentally, the ability of real time measurement in the range of AFP concentration from 0.1ng/ml to 100ng/ml was detected. To compare with conventional methods such as enzyme-linked immunosorbent assay (ELISA) or radioimmunoassay (RIA), the LSPCF fiber-optic biosensor performs higher or comparable detection sensitivity, respectively.

The biological activity of alpha-mangostin, a larvicidal botanic mosquito sterol carrier protein-2 inhibitor.

PubMed

Larson, Ryan T; Lorch, Jeffrey M; Pridgeon, Julia W; Becnel, James J; Clark, Gary G; Lan, Que

2010-03-01

alpha-Mangostin derived from mangosteen was identified as a mosquito sterol carrier protein-2 inhibitor via high throughput insecticide screening, alpha-Mangostin was tested for its larvicidal activity against third instar larvae of six mosquito species, and the median lethal concentration values range from 0.84 to 2.90 ppm. The residual larvicidal activity of alpha-mangostin was examined under semifield conditions. The results indicated that alpha-mangostin was photolytic with a half-life of 53 min in water under full sunlight exposure. The effect of alpha-mangostin on activities of major detoxification enzymes such as P450, glutathione S-transferase, and esterase was investigated. The results showed that alpha-mangostin significantly elevated activities of P450 and glutathione S-transferase in larvae, whereas it suppressed esterase activity. Toxicity of alpha-mangostin against young rats was studied, and there was no detectable adverse effect at dosages as high as 80 mg/kg. This is the first multifaceted study of the biological activity of alpha-mangostin in mosquitoes. The results suggest that alpha-mangostin may be a lead compound for the development of a new organically based mosquito larvicide.

Influence of climate on the tocopherol content of shea butter.

PubMed

Maranz, Steven; Wiesman, Zeev

2004-05-19

The shea tree, Vitellaria paradoxa Gaertner, is the source of a commercial seed fat known as shea butter. High-performance liquid chromatography (HPLC) analysis of the tocopherol content of shea butters from different regions of Africa showed high variability between provenances and a significant effect of climate on alpha-tocopherol levels. The total tocopherol content (alpha, beta, gamma, and delta) in 102 shea butter samples from 11 countries ranged from 29 to 805 microg/g of shea butter, with a mean of 220 microg/g. alpha-Tocopherol, the principal form detected, averaged 64% of the total tocopherol content. Shea butters from Vitellaria populations situated in hot, dry climates had the highest levels of alpha-tocopherol (for example, a mean of 414 microg/g in samples from N'Djamena, Chad). The lowest concentrations of alpha-tocopherol were found in samples from cool highland areas, especially in northern Uganda (a mean of 29 microg/g).

Brain oscillatory subsequent memory effects differ in power and long-range synchronization between semantic and survival processing.

PubMed

Fellner, Marie-Christin; Bäuml, Karl-Heinz T; Hanslmayr, Simon

2013-10-01

Memory crucially depends on the way information is processed during encoding. Differences in processes during encoding not only lead to differences in memory performance but also rely on different brain networks. Although these assumptions are corroborated by several previous fMRI and ERP studies, little is known about how brain oscillations dissociate between different memory encoding tasks. The present study therefore compared encoding related brain oscillatory activity elicited by two very efficient encoding tasks: a typical deep semantic item feature judgment task and a more elaborative survival encoding task. Subjects were asked to judge words either for survival relevance or for animacy, as indicated by a cue presented prior to the item. This allowed dissociating pre-item activity from item-related activity for both tasks. Replicating prior studies, survival processing led to higher recognition performance than semantic processing. Successful encoding in the semantic condition was reflected by a strong decrease in alpha and beta power, whereas successful encoding in the survival condition was related to increased alpha and beta long-range phase synchrony. Moreover, a pre-item subsequent memory effect in theta power was found which did not vary with encoding condition. These results show that measures of local synchrony (power) and global long range-synchrony (phase synchronization) dissociate between memory encoding processes. Whereas semantic encoding was reflected in decreases in local synchrony, increases in global long range synchrony were related to elaborative survival encoding, presumably reflecting the involvement of a more widespread cortical network in this task. Copyright © 2013 Elsevier Inc. All rights reserved.

A Ly{alpha} GALAXY AT REDSHIFT z = 6.944 IN THE COSMOS FIELD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rhoads, James E.; Hibon, Pascale; Malhotra, Sangeeta

2012-06-20

Ly{alpha} emitting galaxies can be used to study cosmological reionization, because a neutral intergalactic medium (IGM) scatters Ly{alpha} photons into diffuse halos whose surface brightness falls below typical survey detection limits. Here, we present the Ly{alpha} emitting galaxy LAE J095950.99+021219.1, identified at redshift z = 6.944 in the COSMOS field using narrowband imaging and follow-up spectroscopy with the IMACS instrument on the Magellan I Baade telescope. With a single object spectroscopically confirmed so far, our survey remains consistent with a wide range of IGM neutral fraction at z Almost-Equal-To 7, but further observations are planned and will help clarify themore » situation. Meantime, the object we present here is only the third Ly{alpha}-selected galaxy to be spectroscopically confirmed at z {approx}> 7, and is {approx}2-3 times fainter than the previously confirmed z Almost-Equal-To 7 Ly{alpha} galaxies.« less

Reduced variability of auditory alpha activity in chronic tinnitus.

PubMed

Schlee, Winfried; Schecklmann, Martin; Lehner, Astrid; Kreuzer, Peter M; Vielsmeier, Veronika; Poeppl, Timm B; Langguth, Berthold

2014-01-01

Subjective tinnitus is characterized by the conscious perception of a phantom sound which is usually more prominent under silence. Resting state recordings without any auditory stimulation demonstrated a decrease of cortical alpha activity in temporal areas of subjects with an ongoing tinnitus perception. This is often interpreted as an indicator for enhanced excitability of the auditory cortex in tinnitus. In this study we want to further investigate this effect by analysing the moment-to-moment variability of the alpha activity in temporal areas. Magnetoencephalographic resting state recordings of 21 tinnitus subjects and 21 healthy controls were analysed with respect to the mean and the variability of spectral power in the alpha frequency band over temporal areas. A significant decrease of auditory alpha activity was detected for the low alpha frequency band (8-10 Hz) but not for the upper alpha band (10-12 Hz). Furthermore, we found a significant decrease of alpha variability for the tinnitus group. This result was significant for the lower alpha frequency range and not significant for the upper alpha frequencies. Tinnitus subjects with a longer history of tinnitus showed less variability of their auditory alpha activity which might be an indicator for reduced adaptability of the auditory cortex in chronic tinnitus.

A capacitive, biocompatible and adhesive electrode for long-term and cap-free monitoring of EEG signals.

PubMed

Lee, Seung Min; Kim, Jeong Hun; Byeon, Hang Jin; Choi, Yoon Young; Park, Kwang Suk; Lee, Sang-Hoon

2013-06-01

Long-term electroencephalogram (EEG) monitoring broadens EEG applications to various areas, but it requires cap-free recording of EEG signals. Our objective here is to develop a capacitive, small-sized, adhesive and biocompatible electrode for the cap-free and long-term EEG monitoring. We have developed an electrode made of polydimethylsiloxane (PDMS) and adhesive PDMS for EEG monitoring. This electrode can be attached to a hairy scalp and be completely hidden by the hair. We tested its electrical and mechanical (adhesive) properties by measuring voltage gain to frequency and adhesive force using 30 repeat cycles of the attachment and detachment test. Electrode performance on EEG was evaluated by alpha rhythm detection and measuring steady state visually evoked potential and N100 auditory evoked potential. We observed the successful recording of alpha rhythm and evoked signals to diverse stimuli with high signal quality. The biocompatibility of the electrode was verified and a survey found that the electrode was comfortable and convenient to wear. These results indicate that the proposed EEG electrode is suitable and convenient for long term EEG monitoring.

In vitro characterization of high purity factor IX concentrates for the treatment of hemophilia B.

PubMed

Limentani, S A; Gowell, K P; Deitcher, S R

1995-04-01

This study employed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and immunoblotting to assess the purity of seven high purity factor IX concentrates: Aimafix (Aima), AlphaNine-SD (Alpha Therapeutic), Factor IX VHP (Biotransfusion), Immunine (Immuno), Mononine (Armour Pharmaceutical), Nanotiv (Kabi Pharmacia), and 9MC (Blood Products Laboratory). The mean specific activity of these products ranged from 68 U factor IX/mg (Aimafix) to 246 U factor IX/mg (Mononine). SDS-PAGE analysis showed that the highest purity product, Mononine, had a single contaminating band under non-reducing conditions. Two additional bands were detected when this product was analyzed under reducing conditions. All other products had multiple contaminating bands that were more apparent under reducing than non-reducing conditions. The immunoblot for factor IX showed a dominant factor IX band for all products. In addition, visible light chain of factor IX was detected for AlphaNine-SD, Factor IX VHP, Immunine, Mononine, Nanotiv, and 9MC, suggesting that the factor IX in these products had undergone partial activation to factor IXa. Another contaminating band was visible at 49,500 for all of the products except 9MC. In addition to this band, high molecular weight contaminants were apparent for some products, most notably AlphaNine-SD. The identity of these bands is unknown. Immunoblotting failed to demonstrate factor VII as a contaminant of any of the high purity products, although factor VIIa could be detected in some lots of Immunine, Nanotiv, and 9MC by a clot-based assay. Factor X contaminated Aimafix, AlphaNine-SD, Factor IX VHP, Immunine, Nanotiv, and 9MC, but activation products of factor X were not detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Film Vetoes for Alpha Background Rejection in Bolometer Detectors

NASA Astrophysics Data System (ADS)

Deporzio, Nicholas; Bucci, Carlo; Canonica, Lucia; Divacri, Marialaura; Cuore Collaboration; Absurd Team

2015-04-01

This study characterizes the effectiveness of encasing bolometer detectors in scintillator, metal ionization, and more exotic films to veto alpha radiation background. Bolometers are highly susceptible to alpha background and a successful veto should boost the statistical strength, speed, and signal-background ratio of bolometer particle searches. Plastic scintillator films are cooled to bolometer temperatures and bombarded with 1.4 MeV to 6.0 MeV alpha particles representative of detector conditions. Photomultipliers detect the keV range scintillation light and produce a veto signal. Also, layered films of a primary metal, dielectric, and secondary metal, such as gold-polyethylene-gold films, are cooled to milli-kelvin temperatures and biased with 0.1V to 100V to produce a current signal when incident 1.4 MeV to 6.0 MeV alpha particles ionize conduction paths through the film. Veto signals are characterized by their affect on bolometer detection of 865 keV target signals. Similar methods are applied to more exotic films. Early results show scintillator films raise target signal count rate and suppress counts above target energy by at least a factor of 10. This indicates scintillation vetoes are effective and that metal ionization and other films under study will also be effective.

ENU mutagenesis identifies mice with cardiac fibrosis and hepatic steatosis caused by a mutation in the mitochondrial trifunctional protein beta-subunit.

PubMed

Kao, Hsiao-Jung; Cheng, Ching-Feng; Chen, Yen-Hui; Hung, Shuen-Iu; Huang, Cheng-Chih; Millington, David; Kikuchi, Tateki; Wu, Jer-Yuarn; Chen, Yuan-Tsong

2006-12-15

Using the metabolomics-guided screening coupled to N-ethyl-N-nitrosourea-mediated mutagenesis, we identified mice that exhibited elevated levels of long-chain acylcarnitines. Whole genome homozygosity mapping with 262 SNP markers mapped the disease gene to chromosome 5 where candidate genes Hadha and Hadhb, encoding the mitochondria trifunctional protein (MTP) alpha- and beta-subunits, respectively, are located. Direct sequencing revealed a normal alpha-subunit, but detected a nucleotide T-to-A transversion in exon 14 (c.1210T>A) of beta-subunit (Hadhb) which resulted in a missense mutation of methionine to lysine (M404K). Western blot analysis showed a significant reduction of both the alpha- and beta-subunits, consistent with reduced enzyme activity in both the long-chain 3-hydroxyacyl-CoA dehydrogenase and the long-chain 3-ketoacyl-CoA thiolase activities. These mice had a decreased weight gain and cardiac arrhythmias which manifested from a prolonged PR interval to a complete atrio-ventricular dissociation, and died suddenly between 9 and 16 months of age. Histopathological studies showed multifocal cardiac fibrosis and hepatic steatosis. This mouse model will be useful to further investigate the mechanisms underlying arrhythmogenesis relating to lipotoxic cardiomyopathy and to investigate pathophysiology and treatment strategies for human MTP deficiency.

Steroid determination in fish plasma using capillary electrophoresis.

PubMed

Bykova, Liliya; Archer-Hartmann, Stephanie A; Holland, Lisa A; Iwanowicz, Luke R; Blazer, Vicki S

2010-09-01

A capillary separation method that incorporates pH-mediated stacking is employed for the simultaneous determination of circulating steroid hormones in plasma from Perca flavescens (yellow perch) collected from natural aquatic environments. The method can be applied to separate eight steroid standards: progesterone, 17alpha,20beta-dihydroxypregn-4-en-3-one, 17alpha-hydroxyprogesterone, testosterone, estrone, 11-ketotestosterone, ethynyl estradiol, and 17beta-estradiol. Based on screening of plasma, the performance of the analytical method was determined for 17alpha,20beta-dihydroxypregn-4-en-3-one, testosterone, 11-ketotestosterone, and 17beta-estradiol. The within-day reproducibility in migration time for these four steroids in aqueous samples was < or =2%. Steroid quantification was accomplished using a calibration curve obtained with external standards. Plasma samples from fish collected from the Choptank and Severn Rivers, Maryland, USA, stored for up to one year were extracted with ethyl acetate and then further processed with anion exchange and hydrophobic solid phase extraction cartridges. The recovery of testosterone and 17beta-estradiol from yellow perch plasma was 84 and 85%, respectively. Endogenous levels of testosterone ranged from 0.9 to 44 ng/ml, and when detected 17alpha,20beta-dihydroxypregn-4-en-3-one ranged from 5 to 34 ng/ml. The reported values for testosterone correlated well with the immunoassay technique. Endogenous concentrations of 17beta-estradiol were < or =1.7 ng/ml. 11-Ketotestosterone was not quantified because of a suspected interferant. Higher levels of 17alpha,20beta-dihydroxypregn-4-en-3-one were found in male and female fish in which 17beta-estradiol was not detected. Monitoring multiple steroids can provide insight into hormonal fluctuations in fish. Copyright 2010 SETAC.

Validation of the Health-Promoting Lifestyle Profile II for Hispanic male truck drivers in the Southwest.

PubMed

Mullins, Iris L; O'Day, Trish; Kan, Tsz Yin

2013-08-01

The aims of the study were to validate the English and Spanish Versions of the Health-Promoting Lifestyle Profile II (HPLP II) with Hispanic male truck drivers and to determine if there were any differences in drivers' responses based on driving responsibility. The methods included a descriptive correlation design, the HPLP II (English and Spanish versions), and a demographic questionnaire. Fifty-two Hispanic drivers participated in the study. There were no significant differences in long haul and short haul drivers' responses to the HPLP II. Cronbach's alpha for the Spanish version was .97 and the subscales alphas ranged from .74 to .94. The English version alpha was .92 and the subscales ranged from .68 to .84. Findings suggest the subscales of Health Responsibility, Physical Activities, Nutrition, and Spirituality Growth on the HPLP II Spanish and English versions may not adequately assess health-promoting behaviors and cultural influences for the Hispanic male population in the southwestern border region.

Detection of alpha radiation in a beta radiation field

DOEpatents

Mohagheghi, Amir H.; Reese, Robert P.

2001-01-01

An apparatus and method for detecting alpha particles in the presence of high activities of beta particles utilizing an alpha spectrometer. The apparatus of the present invention utilizes a magnetic field applied around the sample in an alpha spectrometer to deflect the beta particles from the sample prior to reaching the detector, thus permitting detection of low concentrations of alpha particles. In the method of the invention, the strength of magnetic field required to adequately deflect the beta particles and permit alpha particle detection is given by an algorithm that controls the field strength as a function of sample beta energy and the distance of the sample to the detector.

Autoradiography imaging in targeted alpha therapy with Timepix detector.

PubMed

A L Darwish, Ruqaya; Staudacher, Alexander Hugo; Bezak, Eva; Brown, Michael Paul

2015-01-01

There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy.

Autoradiography Imaging in Targeted Alpha Therapy with Timepix Detector

PubMed Central

AL Darwish, Ruqaya; Staudacher, Alexander Hugo; Bezak, Eva; Brown, Michael Paul

2015-01-01

There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. These data are required to estimate the absorbed dose on a cellular level as alpha particles have a limited range and traverse only a few cells. Tracking of individual alpha particles is possible using the Timepix semiconductor radiation detector. We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. Additionally, the sensitivity of the Timepix detector to monitor variations in tumour uptake based on the necrotic tissue volume was also studied. Compartmental analysis model was used, based on the obtained imaging data, to assess the Th-227 uptake. Results show that alpha particle, photon, electron, and muon tracks were detected and resolved by Timepix detector. The current study demonstrated that individual alpha particle emissions, resulting from targeted alpha therapy, can be visualised and quantified using Timepix detector. Furthermore, the variations in the uptake based on the tumour necrotic volume have been observed with four times higher uptake for tumours pretreated with chemotherapy than for those without chemotherapy. PMID:25688285

Alpha-PVP as an active component of herbal highs in Poland between 2013 and 2015.

PubMed

Byrska, Bogumiła; Stanaszek, Roman; Zuba, Dariusz

2017-08-01

Alpha-PVP (alpha-pyrrolidinovalerophenone, α-PVP) is a synthetic derivative of cathinone. It has been one of the most frequently detected new psychoactive substances (NPS) available on the drug market in recent years in Poland. The usual routes of administration of the drug include oral, insufflation, and injection. Unexpectedly, we dealt with a great number of herbal samples that turned out to contain α-PVP. A total number of 352 herbal samples from 19 cases in which we detected synthetic cathinones, were investigated in the Institute of Forensic Research (IFR) from 2013 to 2015. The seized products that were received by our laboratory were first screened by gas chromatography coupled to mass spectrometry (GC-MS). Quantification of α-PVP and other cathinones was performed by ultra-performance liquid chromatography with photodiode array detection (UPLC-PDA). Of the samples, 84% contained only α-PVP. Other groups of products were those containing only α-PVT, α-PVP and α-PVT, α-PVP and synthetic cannabinoid A-834, 735, and α-PVP and cannabis. In one herbal sample, α-PVP was detected along with caffeine and tadalafil. The herbal products present on the market containing only α-PVP usually had a mass of 0.3 to 0.6 g, and concentration range in this group of samples was 3.0-44.0% (content: 13.0-222.0 mg per package). The amount of α-PVP in samples below 0.30 g was in a range 9-18 mg whiles in samples above 0.60 g it was in the range 30-716 mg. There were also products containing a mixture of α-PVP and α-PVT. In those samples, α-PVP concentrations were: 3.0-6.0% (amount: 15.0-34.0 mg). Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A bipolar outflow of ionized gas in K3-50A: H76 alpha radio recombination line and continuum observations of K3-50

NASA Technical Reports Server (NTRS)

Depree, C. G.; Goss, W. M.; Palmer, Patrick; Rubin, Robert H.

1994-01-01

The H II regions near K3-50 (G70.3 + 1.6) have been imaged at high angular resolution (approximately 1 sec .3) in the continuum and the recombination lines H76(sub alpha and He76(sub alpha) using the Very Large Array (VLA). The helium line is detected in only the brightest component K3-50A while the hydrogen line is detected in three components (K3-50A, B and C1). K3-50A shows a pronounced velocity gradient of approximately 150 km/sec/pc along its major axis (P.A. = 160 deg); in addition a wide range of line widths are observed, from 20 to 65 km/sec. Kinematics from the line data and the morphology of the continuum emission suggest that the ionized material associated with K3-50A is undergoing a high-velocity bipolar outflow.

Lenses in the forest: cross correlation of the Lyman-alpha flux with cosmic microwave background lensing.

PubMed

Vallinotto, Alberto; Das, Sudeep; Spergel, David N; Viel, Matteo

2009-08-28

We present a theoretical estimate for a new observable: the cross correlation between the Lyman-alpha flux fluctuations in quasar spectra and the convergence of the cosmic microwave background as measured along the same line of sight. As a first step toward the assessment of its detectability, we estimate the signal-to-noise ratio using linear theory. Although the signal-to-noise is small for a single line of sight and peaks at somewhat smaller redshifts than those probed by the Lyman-alpha forest, we estimate a total signal-to-noise of 9 for cross correlating quasar spectra of SDSS-III with Planck and 20 for cross correlating with a future polarization based cosmic microwave background experiment. The detection of this effect would be a direct measure of the neutral hydrogen-matter cross correlation and could provide important information on the growth of structures at large scales in a redshift range which is still poorly probed.

Gold nanoparticles based chemiluminescent resonance energy transfer for immunoassay of alpha fetoprotein cancer marker.

PubMed

Huang, Xiangyi; Ren, Jicun

2011-02-07

In this paper, we report a new strategy of chemiluminescence resonance energy transfer (CRET) by using gold nanoparticles (AuNPs) as efficient long-range energy acceptor in sandwich immunoassays. In the design of CRET system, we chose the highly sensitive chemiluminescence (CL) reaction of luminol and hydrogen peroxide catalysed by horseradish peroxidase (HRP) because the CL spectrum of luminol (λ(max) 425 nm) partially overlaps with the visible absorption bands of AuNPs. On the basis of CRET strategy, we developed a sandwich immunoassay of alpha fetoprotein (AFP) cancer marker. In immunoassay, two antibodies (anti-AFP-1 and anti-AFP-2) were conjugated to AuNPs and horseradish peroxidase (HRP), respectively. The sandwich-type immunoreactions between the AFP (antigen) and the two different antibodies bridged the donors (luminol) and acceptors (AuNPs), which led to the occurrence of CRET from luminol to AuNPs upon chemiluminescent reaction. We observed that the quenching of chemiluminescence signal depended linearly on the AFP concentration within a range of concentration from 5 to 70 ng mL(-1) and the detection limit of AFP was 2.5 ng mL(-1). Our method was successfully applied for determination of AFP levels in sera from cancer patients, and the results were in good agreement with ELISA assays. This approach is expected to be extended to other assay designs, that is, using other antibodies, analytes, chemiluminescent substance, and even other metallic nanoparticles. Copyright © 2010 Elsevier B.V. All rights reserved.

Evaluation of pGL1-TNF-alpha therapy in combination with radiation

NASA Technical Reports Server (NTRS)

Li, J.; Andres, M. L.; Fodor, I.; Nelson, G. A.; Gridley, D. S.

1998-01-01

Long-term control of high-grade brain tumors is rarely achieved with current therapeutic regimens. In this study a new plasmid-based human tumor necrosis factor-alpha (TNF-alpha) expression vector was synthesized (pGL1-TNF-alpha) and evaluated together with radiation in the aggressive, rapidly growing C6 rat glioma model. pGL1-TNF-alpha was successfully transfected into C6 cells in vitro using a cationic polyamine method. Expression was detected up to 7 days and averaged 0.4 ng of TNF-alpha in the culture medium from 1x10(5) cells. The expressed protein was biologically functional, as evidenced by growth inhibition of L929, a TNF-alpha-susceptible cell line. Using fluorescence-labeled monoclonal antibodies and laser scanning cytometry, we confirmed that both the P55 and P75 receptors for TNF-alpha were present on the C6 cell membrane. However, the receptors were present at low density and P55 was expressed more than the P75 receptor. These findings were in contrast to results obtained with TNF-alpha-susceptible L929 cells. Tests in athymic mice showed that pGL1-TNF-alpha administered intratumorally 16-18 h before radiation (each modality given three times) significantly inhibited C6 tumor progression (P<0.05). This effect was more than additive, because pGL1-TNF-alpha alone did not slow tumor growth and radiation alone had little effect on tumor growth. These results indicate that pGL1-TNF-alpha has potential to augment the antitumor effects of radiation against a tumor type that is virtually incurable.

A triple-crystal phoswich detector with digital pulse shape discrimination for alpha/beta/gamma spectroscopy

NASA Astrophysics Data System (ADS)

White, Travis L.; Miller, William H.

1999-02-01

Researchers at the University of Missouri - Columbia have developed a three-crystal phoswich detector coupled to a digital pulse shape discrimination system for use in alpha/beta/gamma spectroscopy. Phoswich detectors use a sandwich of scintillators viewed by a single photomultiplier tube to simultaneously detect multiple types of radiation. Separation of radiation types is based upon pulse shape difference among the phosphors, which has historically been performed with analog circuitry. The system uses a GaGe CompuScope 1012, 12 bit, 10 MHz computer-based oscilloscope that digitally captures the pulses from a phoswich detector and subsequently performs pulse shape discrimination with cross-correlation analysis. The detector, based partially on previous phoswich designs by Usuda et al., uses a 10 mg/cm 2 thick layer of ZnS(Ag) for alpha detection, followed by a 0.254 cm CaF 2(Eu) crystal for beta detection, all backed by a 2.54 cm NaI(Tl) crystal for gamma detection. Individual energy spectra and count rate information for all three radiation types are displayed and updated periodically. The system shows excellent charged particle discrimination with an accuracy of greater than 99%. Future development will include a large area beta probe with gamma-ray discrimination, systems for low-energy photon detection (e.g. Bremsstrahlung or keV-range photon emissions), and other health physics instrumentation.

Label-free immunosensor based on Pd nanoplates for amperometric immunoassay of alpha-fetoprotein.

PubMed

Wang, Huan; Li, He; Zhang, Yihe; Wei, Qin; Ma, Hongmin; Wu, Dan; Li, Yan; Zhang, Yong; Du, Bin

2014-03-15

In this paper, Pd nanoplates were used as a kind of electrode materials for fabrication of an electrochemical immunosensor, which was applied for detection of cancer biomarker alpha-fetoprotein (AFP). Thanks to the unique structure and properties of Pd nanoplates, the antibody of AFP (Ab) was effectively immobilized onto the surface of the Pd nanoplates modified glassy carbon electrode (GCE). Moreover, the good electrochemical properties of Pd nanoplates greatly improved the electronic transmission rate and enhanced the electrochemical signal, which led to an increase of the detection sensitivity. Based on the specific antibody-antigen interaction, a label-free immunosensor based on Pd nanoplates was developed for sensing of AFP. The current method allows us to detect AFP over a wide concentration range from 0.01 to 75.0 ng/mL with a detection limit of 4 pg/mL. The proposed immunosensor has been used to determine AFP in human serum with satisfactory results. © 2013 Elsevier B.V. All rights reserved.

Rapid detection of α-thalassaemia variants using droplet digital PCR.

PubMed

Lee, T-Y; Lai, M-I; Ramachandran, V; Tan, J A M A; Teh, L-K; Othman, R; Hussein, N H; George, E

2016-08-01

Alpha thalassaemia is a highly prevalent disease globally and is a well-known public health problem in Malaysia. The deletional forms of the mutation are the most common forms found in alpha thalassaemia. The three most common deletional alpha thalassaemia found in this region include --(SEA) deletion, -α(3.7) rightward and -α(4.2) leftward deletions. The prevalence rate of triplication alpha cases such as ααα(anti3.7) and ααα(anti4.2) is not known in Malaysia although it plays a role in exacerbating the clinical phenotypes in beta thalassaemia carriers. Recently, there have been more reported cases of rare alpha thalassaemia mutations due to the advancement of molecular techniques involved in thalassaemia detections. Therefore, it is essential to develop a new method which allows the detection of different alpha thalassaemia mutations including the rare ones simultaneously and accurately. The purpose of this study was to design an assay for the detection of triplications, common and rare deletional alpha thalassaemia using droplet digital PCR (ddPCR). This is a quantitative detection method to measure the changes of copy number which can detect deletions, duplications and triplications of the alpha globin gene simultaneously. In conclusion, ddPCR is an alternative method for rapid detection of alpha thalassaemia variants in Malaysia. © 2016 John Wiley & Sons Ltd.

Survey of Indoor Radon Concentrations in California Elementary Schools. Final Report.

ERIC Educational Resources Information Center

Zhou, Joey Y.; Liu, Kai-Shen; Waldman, Jed

This paper reports on the concentrations of radon found within a sample of 378 elementary schools in California. Long-term alpha-track radon detectors were placed in 6,485 classrooms within participating schools to detect radon levels for between 220 to 366 days. Only classrooms were tested. Results show that about 5.6 percent of the schools…

Cloning and expression pattern of a gene encoding an alpha-xylosidase active against xyloglucan oligosaccharides from Arabidopsis.

PubMed

Sampedro, J; Sieiro, C; Revilla, G; González-Villa, T; Zarra, I

2001-06-01

An alpha-xylosidase active against xyloglucan oligosaccharides was purified from cabbage (Brassica oleracea var. capitata) leaves. Two peptide sequences were obtained from this protein, the N-terminal and an internal one, and these were used to identify an Arabidopsis gene coding for an alpha-xylosidase that we propose to call AtXYL1. It has been mapped to a region of chromosome I between markers at 100.44 and 107.48 cM. AtXYL1 comprised three exons and encoded a peptide that was 915 amino acids long, with a potential signal peptide of 22 amino acids and eight possible N-glycosylation sites. The protein encoded by AtXYL1 showed the signature regions of family 31 glycosyl hydrolases, which comprises not only alpha-xylosidases, but also alpha-glucosidases. The alpha-xylosidase activity is present in apoplastic extractions from Arabidopsis seedlings, as suggested by the deduced signal peptide. The first eight leaves from Arabidopsis plants were harvested to analyze alpha-xylosidase activity and AtXYL1 expression levels. Both increased from older to younger leaves, where xyloglucan turnover is expected to be higher. When this gene was introduced in a suitable expression vector and used to transform Saccharomyces cerevisiae, significantly higher alpha-xylosidase activity was detected in the yeast cells. alpha-Glucosidase activity was also increased in the transformed cells, although to a lesser extent. These results show that AtXYL1 encodes for an apoplastic alpha-xylosidase active against xyloglucan oligosaccharides that probably also has activity against p-nitrophenyl-alpha-D-glucoside.

Correlation of high-temperature stability of alpha-chymotrypsin with 'salting-in' properties of solution.

PubMed

Levitsky VYu; Panova, A A; Mozhaev, V V

1994-01-15

A correlation between the stability of alpha-chymotrypsin against irreversible thermal inactivation at high temperatures (long-term stability) and the coefficient of Setchenov equation as a measure of salting-in/out efficiency of solutes in the Hofmeister series has been found. An increase in the concentration of salting-in solutes (KSCN, urea, guanidinium chloride, formamide) leads to a many-fold decrease of the inactivation rate of the enzyme. In contrast, addition of salting-out solutes has a small effect on the long-term stability of alpha-chymotrypsin at high temperatures. The effects of solutes are additive with respect to their salting-in/out capacities; the stabilizing action of the solutes is determined by the calculated Setchenov coefficient of solution. The correlation is explained by a solute-driven shift of the conformational equilibrium between the 'low-temperature' native and the 'high-temperature' denatured forms of the enzyme within the range of the kinetic scheme put forward in the preceding paper in this journal: irreversible inactivation of the high-temperature form proceeds much more slowly compared with the low-temperature form.

The serine proteinase inhibitory proteins of the chondrodystrophoid (beagle) and non-chondrodystrophoid (greyhound) canine intervertebral disc.

PubMed

Melrose, J; Taylor, T K; Ghosh, P

1997-06-01

Trypsin inhibitory proteins of low buoyant density (p < or = 1.35 g/mL) fractions were prepared by CsCl density gradient ultracentrifugation of 4 M guanidinium hydrochloride extracts of lumbar beagle and greyhound annulus fibrosus and nucleus pulposus from animals aged 1 to 6 years. Affinity blotting with biotinylated trypsin was used to identify active trypsin inhibitory protein species; these species were also identified immunologically by Western blotting using antibodies against bovine pancreatic trypsin inhibitor (BPTI), and human inter-alpha-trypsin inhibitor (ITI). None of the trypsin inhibitory species evident in Western blots were reactive with anti-human alpha1-proteinase inhibitor (alpha-1-PI), alpha2-macroglobulin or secretory leucocyte proteinase inhibitor. The greyhound intervertebral disc samples generally had higher levels of active trypsin inhibitor species per unit weight of tissue extracted, and a more extensive range of inhibitor species. Inhibitor species of 30, 32, 34 kDa were identified in both beagle and greyhound intervertebral disc samples; these species were generally most prominent in the annulus fibrosus samples. In contrast, the nucleus pulposus samples contained relatively large trypsin inhibitor species; the anti-BPTI detected an inhibitor species of approximately 85-90 kDa; anti-ITI detected species of 120-250 kDa; biotinylated trypsin detected species of 60-110 kDa. A small molecular mass trypsin inhibitor species of 6 kDa, which was of similar mobility to BPTI, was also detected in annulus fibrosus samples; however, this species did not react with anti-BPTI.

Rotational modulation and flares on RS CVn and BY DRA systems. VIII - Simultaneous EXOSAT and H-alpha observations of a flare on the dMe star GL 644 AB (Wolf 630) on 24/25 August 1985

NASA Astrophysics Data System (ADS)

Doyle, J. G.; Butler, C. J.; Callanan, P. J.; Tagliaferri, G.; de La Reza, R.; White, N. E.; Torres, C. A.; Quast, G.

1988-02-01

A large flare was detected simultaneously in X-rays and H-alpha on the visual binary Gl 644 AB at about 00:15 UT on August 25, 1985. The flare was detected with both the low (0.05-2 keV) and medium energy (2-7 keV) experiments onboard Exosat, with the flare rise time being similar in both the low and medium energy ranges, although in the low energy the peak occurred about 30 s later. This was followed a few minutes later by a second burst. The flare decay time lasted about 10 minutes longer in the low energy band than in the medium energy. The integrated flare energy detected was 11.9 x 10 to the 32nd and 4.15 x 10 to the 32nd erg respectively in the low and medium energy X-rays and 7 x 10 to the 31st erg in H-alpha. This gives an H-alpha flux of approximately 4 percent of the total X-ray flux detected from the flare or 6 percent of the low X-ray flare energy, similar to that observed in a compact solar flare. Based on the observed cooling time, the flare was estimated to have 2-3 loops of height about 10 to the 9th cm and electron density of about 10 to the 12th/cu cm.

On the detectability of key-MeV solar protons through their nonthermal Lyman-alpha emission

NASA Technical Reports Server (NTRS)

Canfield, R. C.; Chang, C. R.

1985-01-01

The intensity and timescale of nonthermal Doppler-shifted hydrogen L alpha photon emission as diagnostics of 10 keV to 10 MeV protons bombarding the solar chromosphere during flares are investigated. The steady-state excitation and ionization balance of the proton beam are determined, taking into account all important atomic interactions with the ambient chromosphere. For a proton energy flux comparable to the electron energy flux commonly inferred for large flares, L alpha wing intensities orders of magnitude larger than observed nonflaring values were found. Investigation of timescales for ionization and charge exchange leads researchers to conclude that over a wide range of values of mean proton energy and beam parameters, Doppler-shifted nonthermal L alpha emission is a useful observational diagnostic of the presence of 10 keV to 10 MeV superthermal proton beams in the solar flare chromosphere.

RADIATION COUNTER

DOEpatents

Goldsworthy, W.W.

1958-02-01

This patent relates to a radiation counter, and more particularly, to a scintillation counter having high uniform sensitivity over a wide area and capable of measuring alpha, beta, and gamma contamination over wide energy ranges, for use in quickly checking the contami-nation of personnel. Several photomultiplier tubes are disposed in parallel relationship with a light tight housing behind a wall of scintillation material. Mounted within the housing with the photomultipliers are circuit means for producing an audible sound for each pulse detected, and a range selector developing a voltage proportional to the repetition rate of the detected pulses and automatically altering its time constant when the voltage reaches a predetermined value, so that manual range adjustment of associated metering means is not required.

Executive control processes underlying multi-item working memory

PubMed Central

Lara, Antonio H.; Wallis, Jonathan D.

2014-01-01

A dominant view of prefrontal cortex (PFC) function is that it stores task-relevant information in working memory. To examine this and determine how it applies when multiple pieces of information must be stored, we trained two macaque monkeys to perform a multi-item color change-detection task and recorded activity of neurons in PFC. Few neurons encoded the color of the items. Instead, the predominant encoding was spatial: a static signal reflecting the item's position and a dynamic signal reflecting the animal's covert attention. These findings challenge the notion that PFC stores task-relevant information. Instead, we suggest that the contribution of PFC is in controlling the allocation of resources to support working memory. In support of this, we found that increased power in the alpha and theta bands of PFC local field potentials, which are thought to reflect long-range communication with other brain areas, was correlated with more precise color representations. PMID:24747574

HtrA3 as an Early Marker for Preeclampsia: Specific Monoclonal Antibodies and Sensitive High-Throughput Assays for Serum Screening

PubMed Central

Dynon, Kemperly; Heng, Sophea; Puryer, Michelle; Li, Ying; Walton, Kelly; Endo, Yaeta; Nie, Guiying

2012-01-01

Mammalian HtrA3 (high temperature requirement A3) is a serine protease of the HtrA family. It has two isoforms [long (HtrA3-L) and short (HtrA3-S)] and is important for placental development and cancer progression. Recently, HtrA3 was identified as a potential diagnostic marker for early detection of preeclampsia, a life-threatening pregnancy-specific disorder. Currently there are no high-throughput assays available to detect HtrA3 in human serum. In this study we generated and fully tested a panel of five HtrA3 mouse monoclonal antibodies (mAbs). Three mAbs recognised both HtrA3-L and HtrA3-S and the other two detected HtrA3-L only. All five mAbs were highly specific to HtrA3 and applicable in western blotting and immunohistochemical analysis of endogenous HtrA3 proteins in the mouse and human tissues. Amplified luminescent proximity homogeneous assays-linked immunosorbent assays (AlphaLISAs), were developed to detect HtrA3 isoforms in picomolar levels in serum. The HtrA3 AlphaLISA detected significantly higher serum levels of HtrA3 in women at 13–14 weeks of gestation who subsequently developed preeclampsia compared to gestational-age matched controls. These HtrA3 mAbs are valuable for the development of immunoassays and characterisation of HtrA3 isoform-specific biology. The newly developed HtrA3 AlphaLISA assays are suitable for large scale screening of human serum. PMID:23049902

The nuclear superbubble of NGC 3079

NASA Technical Reports Server (NTRS)

Veilleux, S.; Cecil, G.; Bland-Hawthorn, J.; Tully, R. B.; Filippenko, A. V.; Sargent, W. L. W.

1994-01-01

We have used the Hawaii Imaging Fabry-Perot Interferometer (HIFI) at the CFH 3.6 m telescope to map H-alpha + (N II) lambda-lambda 6548, 6583 emission-line profiles across the entire edge-on, nearby SBc galaxy NGC 3079, with resolution 70 km/s and subarcsecond sampling. Blue and red long-slit spectra were obtained with the Double Spectrograph on the Palomar 5 meter telescope to provide additional emission-line diagnostics. A spectacular, line emitting bubble of diameter 13 sec (approximately 1.1 kpc) is observed immediately east of the nucleus. Its unusual gaseous excitation (e.g., (N II) lambda(6583)/H-alpha greater than 1) suggests that shocks are important. Extremely violent gas motions that range over 2000 km/s are detected across the bubble and diametrically opposite on the west side of the nucleus. Nonrotational motions are also found in the inner galaxy disk. The superbubble of NGC 3079 is the most powerful example known of a wind-blown bubble, and an excellent laboratory to study wind dynamics. The dimensions and energies of the bubble imply that is likely to be in the blowout phase and partially ruptured. The predicted rate of kinetic energy output from the central starburst appears sufficient to power most of this outflow. It is possible that a central active galactic nucleus also contributes to the outflow.

STAR-FORMING GALAXIES IN THE HERCULES CLUSTER: H{alpha} IMAGING OF A2151

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cedres, Bernabe; Iglesias-Paramo, Jorge; VIlchez, Jose Manuel

2009-09-15

This paper presents the first results of an H{alpha} imaging survey of galaxies in the central regions of the A2151 cluster. A total of 50 sources were detected in H{alpha}, from which 41 were classified as secure members of the cluster and 2 as likely members based on spectroscopic and photometric redshift considerations. The remaining seven galaxies were classified as background contaminants and thus excluded from our study on the H{alpha} properties of the cluster. The morphologies of the 43 H{alpha} selected galaxies range from grand design spirals and interacting galaxies to blue compacts and tidal dwarfs or isolated extragalacticmore » H II regions, spanning a range of magnitudes of -21 {<=} M{sub B} {<=} -12.5 mag. From these 43 galaxies, 7 have been classified as active galactic nucleus (AGN) candidates. These AGN candidates follow the L(H{alpha}) versus M{sub B} relationship of the normal galaxies, implying that the emission associated with the nuclear engine has a rather secondary impact on the total H{alpha} emission of these galaxies. A comparison with the clusters Coma and A1367 and a sample of field galaxies has shown the presence of cluster galaxies with L(H{alpha}) lower than expected for their M{sub B} , a consequence of the cluster environment. This fact results in differences in the L(H{alpha}) versus EW(H{alpha}) and L(H{alpha}) distributions of the clusters with respect to the field, and in cluster-to-cluster variations of these quantities, which we propose are driven by a global cluster property as the total mass. In addition, the cluster H{alpha} emitting galaxies tend to avoid the central regions of the clusters, again with different intensity depending on the cluster total mass. For the particular case of A2151, we find that most H{alpha} emitting galaxies are located close to the regions with the higher galaxy density, offset from the main X-ray peak. Overall, we conclude that both the global cluster environment and the cluster merging history play a non-negligible role in the integral star formation properties of clusters of galaxies.« less

An improved electrostatic integrating radon monitor with the CR-39 as alpha-particle detector.

PubMed

Fan, D; Zhuo, W; Chen, B; Zhao, C; Yi, Y; Zhang, Y

2015-11-01

In this study, based on the electrostatic integrating radon monitor (EIRM) developed by Iida et al., a new type of EIRM with the allyl glycol carbonate (CR-39) as alpha-particle detector was developed for outdoor radon measurements. Besides using the CR-39 to replace the cellulose nitrate film as alpha-particle detector, the electrode and the setting place of the CR-39 were also optimally designed based on the simulation results of the electric field and the detection efficiency. The calibration factor of the new EIRM was estimated to be 0.136±0.002 tracks cm(-2) (Bq m(-3) h)(-1), with the lower detection limit of 0.6 Bq m(-3) for a 2-month exposure. Furthermore, both the battery and the dry agent were also replaced to protect the environment. The results of intercomparison and field experiments showed that the performances of the new EIRM were much better than the original one. It suggests that the new type of ERIM is more suitable for large-scale and long-term outdoor radon surveys. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Alpha-2-Macroglobulin Is Acutely Sensitive to Freezing and Lyophilization: Implications for Structural and Functional Studies

PubMed Central

Wyatt, Amy R.; Kumita, Janet R.; Farrawell, Natalie E.; Dobson, Christopher M.; Wilson, Mark R.

2015-01-01

Alpha-2-macroglobulin is an abundant secreted protein that is of particular interest because of its diverse ligand binding profile and multifunctional nature, which includes roles as a protease inhibitor and as a molecular chaperone. The activities of alpha-2-macroglobulin are typically dependent on whether its conformation is native or transformed (i.e. adopts a more compact conformation after interactions with proteases or small nucleophiles), and are also influenced by dissociation of the native alpha-2-macroglobulin tetramer into stable dimers. Alpha-2-macroglobulin is predominately present as the native tetramer in vivo; once purified from human blood plasma, however, alpha-2-macroglobulin can undergo a number of conformational changes during storage, including transformation, aggregation or dissociation. We demonstrate that, particularly in the presence of sodium chloride or amine containing compounds, freezing and/or lyophilization of alpha-2-macroglobulin induces conformational changes with functional consequences. These conformational changes in alpha-2-macroglobulin are not always detected by standard native polyacrylamide gel electrophoresis, but can be measured using bisANS fluorescence assays. Increased surface hydrophobicity of alpha-2-macroglobulin, as assessed by bisANS fluorescence measurements, is accompanied by (i) reduced trypsin binding activity, (ii) increased chaperone activity, and (iii) increased binding to the surfaces of SH-SY5Y neurons, in part, via lipoprotein receptors. We show that sucrose (but not glycine) effectively protects native alpha-2-macroglobulin from denaturation during freezing and/or lyophilization, thereby providing a reproducible method for the handling and long-term storage of this protein. PMID:26103636

A practical extension of hydrodynamic theory of porous transport for hydrophilic solutes.

PubMed

Bassingthwaighte, James B

2006-03-01

The equations for transport of hydrophilic solutes through aqueous pores provide a fundamental basis for examining capillary-tissue exchange and water and solute flux through transmembrane channels, but the theory remains incomplete for ratios, alpha, of sphere diameters to pore diameters greater than 0.4. Values for permeabilities, P, and reflection coefficients, sigma, from Lewellen, working with Lightfoot et al., at alpha = 0.5 and 0.95, were combined with earlier values for alpha < 0.4, and the physically required values at alpha = 1.0, to provide accurate expressions over the whole range of 0 < alpha < 1. The "data" were the long-accepted theory for alpha < 0.2 and the computational results from Lewellen and Lightfoot et al. on hard spheres (of 5 different alpha's) moving by convection and diffusion through a tight cylindrical pore, accounting for molecular exclusion, viscous forces, pressure drop, torque and rotation of spheres off the center line (averaging across all accessible radial positions), and the asymptotic values at alpha = 1.0. Coefficients for frictional hindrance to diffusion, F(alpha), and drag, G(alpha), and functions for sigma(alpha) and P(alpha), were represented by power law functions and the parameters optimized to give best fits to the combined "data." The reflection coefficient sigma = {1 - [1 - (1 - phi)2]G'(alpha)} + 2alpha2 phi F'(alpha), and the relative permeability P/Pmax = phi F '(alpha)[1 + 9alpha5.5 x (1.0 - alpha5)0.02], where phi is the partition coefficient or volume fraction of the pore available to solute. The new expression for the diffusive hindrance is F'(alpha) = (1 - alpha2)(3/2) phi/[1 + 0.2 x alpha2 x (1 - alpha2)16], and for the drag factor is G'(alpha) = (1 - 2alpha(2)/3 - 0.20217 alpha5)/(1 - 0.75851 alpha5) - 0.0431[1 - (1 - alpha10)]. All of these converge monotonically to the correct limits at alpha = 1. These are the first expressions providing hydrodynamically based estimates of sigma(alpha) and P(alpha) over 0 < alpha < 1 They should be accurate to within 1-2%.

Transfer RNA mimicry among tymoviral genomic RNAs ranges from highly efficient to vestigial.

PubMed

Dreher, T W; Goodwin, J B

1998-10-01

Three tRNA-associated properties of a representative set of tymoviral RNAs have been quantitatively assessed using higher plant (wheat germ) proteins: aminoacylation, EF-1alpha*GTP binding, and 3'-adenylation of 3'-CC forms of the RNAs by CTP, ATP:tRNA nucleotidyltransferase. The RNAs fall into three classes differing in the extent of tRNA mimicry. Turnip yellow mosaic (TYMV) and kennedya yellow mosaic virus RNAs had activities in all three properties similar to those of a higher plant tRNAValtranscript, and thus are remarkable tRNA mimics. Although the isolated approximately 83 nt long tRNA-like structures showed high activity in these assays, in the case of TYMV, the 6318 nt long TYMV RNA was an even better substrate for valylation. Eggplant mosaic virus RNA, which has a differently constructed acceptor stem pseudoknot, differed from the above tymoviral RNAs in binding more weakly to EF-1alpha*GTP. Erysimum latent virus RNA, which lacks an identifiable anticodon domain, could not be valylated and had very low 3'-adenylation activity. The range of tRNA mimicry within the tymovirus genus thus ranges from extremely highly developed to minimal. The implications on the role of the tRNA mimicry in viral biology are discussed.

Evaluation of Long-Range Lightning Detection Networks Using TRMM/LIS Observations

NASA Technical Reports Server (NTRS)

Rudlosky, Scott D.; Holzworth, Robert H.; Carey, Lawrence D.; Schultz, Chris J.; Bateman, Monte; Cecil, Daniel J.; Cummins, Kenneth L.; Petersen, Walter A.; Blakeslee, Richard J.; Goodman, Steven J.

2011-01-01

Recent advances in long-range lightning detection technologies have improved our understanding of thunderstorm evolution in the data sparse oceanic regions. Although the expansion and improvement of long-range lightning datasets have increased their applicability, these applications (e.g., data assimilation, atmospheric chemistry, and aviation weather hazards) require knowledge of the network detection capabilities. Toward this end, the present study evaluates data from the World Wide Lightning Location Network (WWLLN) using observations from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite. The study documents the WWLLN detection efficiency and location accuracy relative to LIS observations, describes the spatial variability in these performance metrics, and documents the characteristics of LIS flashes that are detected by WWLLN. Improved knowledge of the WWLLN detection capabilities will allow researchers, algorithm developers, and operational users to better prepare for the spatial and temporal coverage of the upcoming GOES-R Geostationary Lightning Mapper (GLM).

Comprehensive long-term efficacy and safety of recombinant human alpha-mannosidase (velmanase alfa) treatment in patients with alpha-mannosidosis.

PubMed

Lund, Allan M; Borgwardt, Line; Cattaneo, Federica; Ardigò, Diego; Geraci, Silvia; Gil-Campos, Mercedes; De Meirleir, Linda; Laroche, Cécile; Dolhem, Philippe; Cole, Duncan; Tylki-Szymanska, Anna; Lopez-Rodriguez, Monica; Guillén-Navarro, Encarna; Dali, Christine I; Héron, Bénédicte; Fogh, Jens; Muschol, Nicole; Phillips, Dawn; Van den Hout, J M Hannerieke; Jones, Simon A; Amraoui, Yasmina; Harmatz, Paul; Guffon, Nathalie

2018-05-03

Long-term outcome data provide important insights into the clinical utility of enzyme replacement therapies. Such data are presented for velmanase alfa in the treatment of alpha-mannosidosis (AM). Patient data (n = 33; 14 adults, 19 paediatric) from the clinical development programme for velmanase alfa were integrated in this prospectively-designed analysis of long-term efficacy and safety. Patients who participated in the phase I/II or phase III trials and were continuing to receive treatment after completion of the trials were invited to participate in a comprehensive evaluation visit to assess long-term outcomes. Primary endpoints were changes in serum oligosaccharide and the 3-minute stair climb test (3MSCT). Mean (SD) treatment exposure was 29.3 (15.2) months. Serum oligosaccharide levels were significantly reduced in the overall population at 12 months (mean change: -72.7%, P < 0.001) and remained statistically significant at last observation (-62.8%, P < 0.001). A mean improvement of +9.3% in 3MSCT was observed at 12 months (P = 0.013), which also remained statistically significant at last observation (+13.8%, P = 0.004), with a more pronounced improvement detected in the paediatric subgroup. No treatment-emergent adverse events were reported leading to permanent treatment discontinuation. Patients treated with velmanase alfa experienced improvements in biochemical and functional measures that were maintained for up to 4 years. Long term follow-up is important and further supports the use of velmanase alfa as an effective and well-tolerated treatment for AM. Based on the currently available data set, no baseline characteristic can be predictive of treatment outcome. Early treatment during paediatric age showed better outcome in functional endpoints.

Use of Concept of Chemotherapy-Equivalent Biologically Effective Dose to Provide Quantitative Evaluation of Contribution of Chemotherapy to Local Tumor Control in Chemoradiotherapy Cervical Cancer Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Plataniotis, George A.; Dale, Roger G.

2008-12-01

Purpose: To express the magnitude of the contribution of chemotherapy to local tumor control in chemoradiotherapy cervical cancer trials in terms of the concept of the biologically effective dose. Methods and Materials: The local control rates of both arms of each study (radiotherapy vs. radiotherapy plus chemotherapy) reported from randomized controlled trials of concurrent chemoradiotherapy for cervical cancer were reviewed and expressed using the Poisson model for tumor control probability (TCP) as TCP = exp(-exp E), where E is the logarithm of cell kill. By combining the two TCP values from each study, we calculated the chemotherapy-related log cell killmore » as Ec = ln[(lnTCP{sub Radiotherapy})/(lnTCP{sub Chemoradiotherapy})]. Assuming a range of radiosensitivities ({alpha} = 0.1-0.5 Gy{sup -1}) and taking the calculated log cell kill, we calculated the chemotherapy-BED, and using the linear quadratic model, the number of 2-Gy fractions corresponding to each BED. The effect of a range of tumor volumes and radiosensitivities ({alpha} Gy{sup -1}) on the TCP was also explored. Results: The chemotherapy-equivalent number of 2-Gy fractions range was 0.2-4 and was greater in tumors with lower radiosensitivity. In those tumors with intermediate radiosensitivity ({alpha} = 0.3 Gy{sup -1}), the equivalent number of 2-Gy fractions was 0.6-1.3, corresponding to 120-260 cGy of extra dose. The opportunities for clinically detectable improvement are only available in tumors with intermediate radiosensitivity with {alpha} = 0.22-0.28 Gy{sup -1}. The dependence of TCP on the tumor volume decreases as the radiosensitivity increases. Conclusion: The results of our study have shown that the contribution of chemotherapy to the TCP in cervical cancer is expected to be clinically detectable in larger and less-radiosensitive tumors.« less

Gold nanoparticle labeling with tyramide signal amplification for highly sensitive detection of alpha fetoprotein in human serum by ICP-MS.

PubMed

Li, Xiaoting; Chen, Beibei; He, Man; Xiao, Guangyang; Hu, Bin

2018-01-01

In this work, we developed an immunoassay based on tyramide signal amplification (TSA) and gold nanoparticles (Au NPs) labeling for highly sensitive detection of alpha fetoprotein (AFP) by inductively coupled plasma mass spectrometry (ICP-MS). AFP was captured by anti-AFP1 coating on the 96-well plate and labeled by anti-AFP2-horseradish peroxidase (HRP), in which the HRP can catalyze the deposition of biotinylated tyramine on the nearby protein. Then the streptavidin (SA)-Au NPs was labeled on the deposited biotinylated tyramine as the intensive signal probe for ICP-MS measurement. Under the optimal experimental conditions, the limit of detection of the developed method for AFP was 1.85pg/mL and the linear range was 0.005-2ng/mL. The relative standard deviation for seven replicate detections of 0.01ng/mL AFP was 5.2%. The proposed method was successfully applied to the detection of AFP in human serum with good recoveries. This strategy is highly sensitive and easy to operate, and can be extended to the sensitive detection of other biomolecules in human serum. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of the Performance of the Near-Bottom Hydrophones of the U.S. Navy Southern California Offshore Range in Detecting, Localizing and Reconstructing 10-20 kHz Odontocete Whistles

DTIC Science & Technology

2008-03-01

Stafford et al. ( 1998 ) utilized MSP for long range and acoustic detection and localization of blue whale calls in the northeast Pacific Ocean...J. Acoust . Soc. Am. 107 (6):3496:3508 (2000). Stafford , K. M., Fox, C. G., Clark, D. S., “ Long - range acoustic detection and localization of blue ...OF THE PERFORMANCE OF THE NEAR- BOTTOM HYDROPHONES OF THE U.S. NAVY SOUTHERN CALIFORNIA OFFSHORE

Functional and genomic analyses of alpha-solenoid proteins.

PubMed

Fournier, David; Palidwor, Gareth A; Shcherbinin, Sergey; Szengel, Angelika; Schaefer, Martin H; Perez-Iratxeta, Carol; Andrade-Navarro, Miguel A

2013-01-01

Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others). While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/.

High-alpha band synchronization across frontal, parietal and visual cortex mediates behavioral and neuronal effects of visuospatial attention.

PubMed

Lobier, Muriel; Palva, J Matias; Palva, Satu

2018-01-15

Visuospatial attention prioritizes processing of attended visual stimuli. It is characterized by lateralized alpha-band (8-14 Hz) amplitude suppression in visual cortex and increased neuronal activity in a network of frontal and parietal areas. It has remained unknown what mechanisms coordinate neuronal processing among frontoparietal network and visual cortices and implement the attention-related modulations of alpha-band amplitudes and behavior. We investigated whether large-scale network synchronization could be such a mechanism. We recorded human cortical activity with magnetoencephalography (MEG) during a visuospatial attention task. We then identified the frequencies and anatomical networks of inter-areal phase synchronization from source localized MEG data. We found that visuospatial attention is associated with robust and sustained long-range synchronization of cortical oscillations exclusively in the high-alpha (10-14 Hz) frequency band. This synchronization connected frontal, parietal and visual regions and was observed concurrently with amplitude suppression of low-alpha (6-9 Hz) band oscillations in visual cortex. Furthermore, stronger high-alpha phase synchronization was associated with decreased reaction times to attended stimuli and larger suppression of alpha-band amplitudes. These results thus show that high-alpha band phase synchronization is functionally significant and could coordinate the neuronal communication underlying the implementation of visuospatial attention. Copyright © 2017 Elsevier Inc. All rights reserved.

Long-term stability of diurnal salivary cortisol and alpha-amylase secretion patterns.

PubMed

Skoluda, Nadine; La Marca, Roberto; Gollwitzer, Mario; Müller, Andreas; Limm, Heribert; Marten-Mittag, Birgitt; Gündel, Harald; Angerer, Peter; Nater, Urs M

2017-06-01

This study aimed to investigate long-term stability and variability of diurnal cortisol and alpha-amylase patterns. Diurnal cortisol and alpha-amylase secretion patterns were assessed on a single workday with three waves of measurement across a total time period of 24months in 189 participants. Separate hierarchical linear models were analyzed, with and without a number of potential predictor variables (age, BMI, smoking, chronic stress, stress reactivity). While low long-term stability was found in diurnal cortisol, the stability of diurnal alpha-amylase was moderate across the time period of 24months. Several predictor variables had a positive impact on diurnal cortisol and alpha-amylase secretion patterns averaged across waves. Our findings underpin the notion that long-term stability is not necessarily warranted in longitudinal studies. It is important to choose an appropriate study design when attempting to disentangle clinically and biologically relevant changes from naturally occurring variations in diurnal cortisol and alpha-amylase. Copyright © 2017 Elsevier Inc. All rights reserved.

Tonic pain and continuous EEG: prediction of subjective pain perception by alpha-1 power during stimulation and at rest.

PubMed

Nir, Rony-Reuven; Sinai, Alon; Moont, Ruth; Harari, Eyal; Yarnitsky, David

2012-03-01

Pain neurophysiology has been chiefly characterized via event-related potentials (ERPs), which are exerted using brief, phase-locked noxious stimuli. Striving for objectively characterizing clinical pain states using more natural, prolonged stimuli, tonic pain has been recently associated with the individual peak frequency of alpha oscillations. This finding encouraged us to explore whether alpha power, reflecting the magnitude of the synchronized activity within this frequency range, will demonstrate a corresponding relationship with subjective perception of tonic pain. Five-minute-long continuous EEG was recorded in 18 healthy volunteers under: (i) resting-state; (ii) innocuous temperature; and (iii) psychophysically-anchored noxious temperature. Numerical pain scores (NPSs) collected during the application of tonic noxious stimuli were tested for correlation with alpha-1 and alpha-2 power. NPSs and alpha power remained stable throughout the recording conditions (Ps⩾0.381). In the noxious condition, alpha-1 power obtained at the bilateral temporal scalp was negatively correlated with NPSs (Ps⩽0.04). Additionally, resting-state alpha-1 power recorded at the bilateral temporal scalp was negatively correlated with NPSs reported during the noxious condition (Ps⩽0.038). Current findings suggest alpha-1 power may serve as a direct, objective and experimentally stable measure of subjective perception of tonic pain. Furthermore, resting-state alpha-1 power might reflect individuals' inherent tonic pain responsiveness. The relevance of alpha-1 power to tonic pain perception may deepen the understanding of the mechanisms underlying the processing of prolonged noxious stimulation. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

[Methodological study for detecting gene mutation of family with genotyping of compound heterogenicity of SEA alpha-thalassemia 1 and HbCS].

PubMed

Chen, Jian; Luo, Bi; Qi, Zhu; Huo, Pei-Dan; Zhang, Quan-Sheng; Wang, Hong

2010-06-01

This study was aimed to establish a method of PCR combination with PCR-RFLP for detecting the South-East Asian (SEA) deletion type alpha-thalassemia 1 and non-deletion mutation of Hb Constant Spring (CS), and to investigate the application value of this method. For the members of the families with alpha-thalassemia, SEA deletion mutation was detected by PCR, then the HbCS point mutation was screened by PCR-RFLP. The results indicated that 15 carriers with alpha-thalassemia (--(SEA)/) were found in 19 members from 7 families, and 2 families with genotype of --(SEA)/alpha(CS)alpha were screened out successfully. It is concluded that the PCR combination with PCR-RFLP is a simple, rapid, and reliable method for screening HbH disease with genotype of --(SEA)/alpha(CS)alpha.

Absence of detectable immunoreactive alpha melanocyte stimulating hormone in plasma in various types of Cushing's disease.

PubMed

Croughs, R J; Thijssen, J H; Mol, J A

1991-03-01

We have measured alpha-MSH in plasma of normal subjects and subjects with various diseases of the pituitary-adrenocortical system using a radioimmunoassay with a sensitivity of 1.2 pmol/l. No alpha-MSH could be detected in plasma of normal subjects (n = 6), in plasma of patients with Addison's disease (n = 3), Nelson's syndrome (n = 2), bromocriptine responsive (n = 2) and unresponsive (n = 5) Cushing's disease and in plasma of psychiatric patients on chronic treatment with the dopamine antagonist haloperidol (n = 5). Plasma alpha-MSH remained undetectable in 2 patients with Cushing's disease after iv injection of 60 micrograms/kg haloperidol. In contrast, alpha-MSH was detectable in plasma of normal dogs (n = 2) and dogs with pituitary dependent hyperadrenocorticism (n = 2), whereas the iv injection of halo peridol was associated with a rise of plasma alpha-MSH. Thus we are unable to detect circulating alpha-MSH in man despite the use of a sensitive radioimmunoassay.

[Determination of serum or plasma alpha-tocopherol by high performance liquid chromatography: optimization of operative models].

PubMed

Jezequel-Cuer, M; Le Moël, G; Mounié, J; Peynet, J; Le Bizec, C; Vernet, M H; Artur, Y; Laschi-Loquerie, A; Troupel, S

1995-01-01

A previous multicentric study set up by the Société française de biologie clinique has emphasized the usefulness of a standardized procedure for the determination by high performance liquid chromatography of alpha-tocopherol in serum or plasma. In our study, we have tested every step of the different published procedures: internal standard adduct, lipoprotein denaturation and vitamin extraction. Reproducibility of results was improved by the use of tocol as an internal standard when compared to retinol or alpha-tocopherol acetates. Lipoprotein denaturation was more efficient with ethanol addition than with methanol and when the ethanol/water ratio was > or = 0.7. Use of n-hexane or n-heptane gave the same recovery of alpha-tocopherol. When organic solvent/water ratio was > or = 1, n-hexane enabled to efficiently extract, in a one-step procedure, the alpha-tocopherol from both normo and hyperlipidemic sera. Performances of the selected procedure were: detection limit: 0.5 microM--linear range: 750 microM--within run coefficient of variation: 2.03%--day to day: 4.76%. Finally, this pluricentric study allows us to propose an optimised procedure for the determination of alpha-tocopherol in serum or plasma.

Determinants of wheat antigen and fungal alpha-amylase exposure in bakeries.

PubMed

Burstyn, I; Teschke, K; Bartlett, K; Kennedy, S M

1998-05-01

The study's objectives were to measure flour antigen exposure in bakeries and define the determinants of exposure. Ninety-six bakery workers, employed in seven different bakeries, participated in the study. Two side-by-side full-shift inhalable dust samples were obtained from each study participant on a single occasion. The flour antigen exposure was measured as wheat antigen and fungal alpha-amylase content of the water-soluble fraction of inhalable dust, assayed via enzyme-linked immunosorbent assays. During the entire sampling period bakers were observed and information on 14 different tasks was recorded at 15-minute intervals. Other production characteristics were also recorded for each sampling day and used in statistical modeling to identify significant predictors of exposure. The mean alpha-amylase antigen exposure was 22.0 ng/m3 (ranging from below the limit of detection of 0.1 ng/m3 to 307.1 ng/m3) and the mean wheat antigen exposure was 109 micrograms/m3 (ranging from below the limit of detection of 1 microgram/m3 to 1018 micrograms/m3). Regression models that explained 74% of variability in wheat antigen and alpha-amylase antigen exposures were constructed. The models indicated that tasks such as weighing, pouring, and operating dough-brakers increased flour antigen exposure, while packing and decorating resulted in lower exposures. Croissant, puff-pastry, and bread/bun production lines were associated with increased exposure, while cake production and substitution of dusting with the use of divider oil were associated with decreased exposure. Exposure levels can be reduced by the automation of forming tasks, alteration of tasks requiring pouring of flour, and changes to the types of products manufactured.

Prognostic value of the immunocytochemical detection of extramural venous invasion in Dukes' C colorectal adenocarcinomas. A preliminary study.

PubMed Central

Lapertosa, G.; Baracchini, P.; Fulcheri, E.; Tanzi, R.

1989-01-01

In postsurgical staging of colorectal adenocarcinomas, it is sometimes difficult to determine the range of possible venous spread. Distinguishing between the extramural veins (especially when the neoplastic embolus takes up the whole lumen and the endothelium cannot be identified) and the smallest extramural lymph nodes (when they are completely replaced by metastatic carcinoma, leaving the capsule alone) is also difficult. This work proposes a more precise definition of true venous invasion to improve histopathologic staging. Immunohistochemical techniques employing commercial antibodies against Factor VIII RAG, with and without enzymatic digestion, and UEA I lectin for residual endothelium detection, were applied, as well as antibodies against vimentin, desmin, and alpha sm-1 actin to detect wall components. The immunohistochemical evaluation of colorectal adenocarcinomas, in particular by anti-alpha sm-1 actin antibodies, permitted a reliable morphologic distinction of the true venous invasion. This factor proved to be relevant for survival rate prediction. Images Figure 1 Figure 2 PMID:2817085

The EEG Split Alpha Peak: Phenomenological Origins and Methodological Aspects of Detection and Evaluation.

PubMed

Olejarczyk, Elzbieta; Bogucki, Piotr; Sobieszek, Aleksander

2017-01-01

Electroencephalographic (EEG) patterns were analyzed in a group of ambulatory patients who ranged in age and sex using spectral analysis as well as Directed Transfer Function, a method used to evaluate functional brain connectivity. We tested the impact of window size and choice of reference electrode on the identification of two or more peaks with close frequencies in the spectral power distribution, so called "split alpha." Together with the connectivity analysis, examination of spatiotemporal maps showing the distribution of amplitudes of EEG patterns allowed for better explanation of the mechanisms underlying the generation of split alpha peaks. It was demonstrated that the split alpha spectrum can be generated by two or more independent and interconnected alpha wave generators located in different regions of the cerebral cortex, but not necessarily in the occipital cortex. We also demonstrated the importance of appropriate reference electrode choice during signal recording. In addition, results obtained using the original data were compared with results obtained using re-referenced data, using average reference electrode and reference electrode standardization techniques.

[Alpha interferon induced hyperthyroidism: a case report and review of the literature].

PubMed

Maiga, I; Valdes-Socin, H; Thiry, A; Delwaide, J; Sidibe, A T; Beckers, A

2015-01-01

Treatment with alpha interferon in hepatitis C triggers a thyroid autoimmunity in a variable percentage of cases (2-8%). This complication raises some questions about its screening, the possibility to continue anti-viral therapy and thyroid treatment. Alpha interferon has an immunomodulatory effect on the thyroid, but also an inhibitory effect on thyroid hormone synthesis. This explains the occurrence of cases of thyroid dysfunction, which often remain undetected because of their latency. Factors predicting thyroid dysfunction with interferon use are: female sex, history of thyroid disease and previous autoimmunity. Several clinical aspects are encountered including hypothyroidism (the most frequent depending on the series) and hyperthyroidism related to Graves' disease. For their detection, a cooperation between general practionners, gastroenterologists and endocrinologists is mandatory thyroid function tests are requested before, during and after treatment,with alpha interferon. Therapeutic aspects of thyroid disorders range from simple monitoring to symptomatic treatment, such as thyroxine prescription in the presence of hypothyroidism. Antithyroid drugs radioactive iodine or thyroid surgery are used in cases of severe or persistent Graves' disease induced by alpha interferon.

The Use of AlphaScreen Technology in HTS: Current Status

PubMed Central

Eglen, Richard M; Reisine, Terry; Roby, Philippe; Rouleau, Nathalie; Illy, Chantal; Bossé, Roger; Bielefeld, Martina

2008-01-01

AlphaScreen (Amplified Luminescent Proximity Homogeneous Assay Screen) is versatile assay technology developed to measuring analytes using a homogenous protocol. This technology is an example of a bead-based proximity assay and was developed from a diagnostic assay technology known as LOCI (Luminescent Oxygen Channeling Assay). Here, singlet oxygen molecules, generated by high energy irradiation of Donor beads, travel over a constrained distance (approx. 200 nm) to Acceptor beads. This results in excitation of a cascading series of chemical reactions, ultimately causing generation of a chemiluminescent signal. In the past decade, a wide variety of applications has been reported, ranging from detection of analytes involved in cell signaling, including protein:protein, protein:peptide, protein:small molecule or peptide:peptide interactions. Numerous homogeneous HTS-optimized assays have been reported using the approach, including generation of second messengers (such as accumulation of cyclic AMP, cyclic GMP, inositol [1, 4, 5] trisphosphate or phosphorylated ERK) from liganded GPCRs or tyrosine kinase receptors, post-translational modification of proteins (such as proteolytic cleavage, phosphorylation, ubiquination and sumoylation) as well as protein-protein and protein-nucleic acid interactions. Recently, the basic AlphaScreen technology was extended in that the chemistry of the Acceptor bead was modified such that emitted light is more intense and spectrally defined, thereby markedly reducing interference from biological fluid matrices (such as trace hemolysis in serum and plasma). In this format, referred to as AlphaLISA, it provides an alternative technology to classical ELISA assays and is suitable for high throughput automated fluid dispensing and detection systems. Collectively, AlphaScreen and AlphaLISA technologies provide a facile assay platform with which one can quantitate complex cellular processes using simple no-wash microtiter plate based assays. They provide the means by which large compound libraries can be screened in a high throughput fashion at a diverse range of therapeutically important targets, often not readily undertaken using other homogeneous assay technologies. This review assesses the current status of the technology in drug discovery, in general, and high throughput screening (HTS), in particular. PMID:20161822

Method for detecting and correcting for isotope burn-in during long-term neutron dosimetry exposure

DOEpatents

Ruddy, Francis H.

1988-01-01

A method is described for detecting and correcting for isotope burn-in during-long term neutron dosimetry exposure. In one embodiment, duplicate pairs of solid state track recorder fissionable deposits are used, including a first, fissionable deposit of lower mass to quantify the number of fissions occuring during the exposure, and a second deposit of higher mass to quantify the number of atoms of for instance .sup.239 Pu by alpha counting. In a second embodiment, only one solid state track recorder fissionable deposit is used and the resulting higher track densities are counted with a scanning electron microscope. This method is also applicable to other burn-in interferences, e.g., .sup.233 U in .sup.232 Th or .sup.238 Pu in .sup.237 Np.

Beyond detection: nuclear physics with a webcam in an educational setting

NASA Astrophysics Data System (ADS)

Pallone, Arthur

2015-03-01

Nuclear physics affects our daily lives in such diverse fields from medicine to art. I believe three obstacles - limited time, lack of subject familiarity and thus comfort on the part of educators, and equipment expense - must be overcome to produce a nuclear-educated populace. Educators regularly use webcams to actively engage students in scientific discovery as evidenced by a literature search for the term webcam paired with topics such as astronomy, biology, and physics. Inspired by YouTube videos that demonstrate alpha particle detection by modified webcams, I searched for examples that go beyond simple detection with only one education-oriented result - the determination of the in-air range of alphas using a modified CCD camera. Custom-built, radiation-hardened CMOS detectors exist in high energy physics and for soft x-ray detection. Commercial CMOS cameras are used for direct imaging in electron microscopy. I demonstrate charged-particle spectrometry with a slightly modified CMOS-based webcam. When used with inexpensive sources of radiation and free software, the webcam charged-particle spectrometer presents educators with a simple, low-cost technique to include nuclear physics in science education.

A new method for evaluating radon and thoron alpha-activities per unit volume inside and outside various natural material samples by calculating SSNTD detection efficiencies for the emitted alpha-particles and measuring the resulting track densities.

PubMed

Misdaq, M A; Aitnouh, F; Khajmi, H; Ezzahery, H; Berrazzouk, S

2001-08-01

A Monte Carlo computer code for determining detection efficiencies of the CR-39 and LR-115 II solid-state nuclear track detectors (SSNTD) for alpha-particles emitted by the uranium and thorium series inside different natural material samples was developed. The influence of the alpha-particle initial energy on the SSNTD detection efficiencies was investigated. Radon (222Rn) and thoron (220Rn) alpha-activities per unit volume were evaluated inside and outside the natural material samples by exploiting data obtained for the detection efficiencies of the SSNTD utilized for the emitted alpha-particles, and measuring the resulting track densities. Results obtained were compared to those obtained by other methods. Radon emanation coefficients have been determined for some of the considered material samples.

Use of the Filovirus Animal Non-Clinical Group (FANG) Ebola virus immuno-assay requires fewer study participants to power a study than the Alpha Diagnostic International assay

PubMed Central

Logue, James; Tuznik, Kaylie; Follmann, Dean; Grandits, Greg; Marchand, Jonathan; Reilly, Cavan; Sarro, Yeya dit Sadio; Pettitt, James; Stavale, Eric J.; Fallah, Mosoka; Olinger, Gene G.; Bolay, Fatorma K.; Hensley, Lisa E.

2018-01-01

As part of the scientific community’s development of medical countermeasures against Ebola virus disease, optimization of standardized assays for product evaluation is paramount. The recent outbreak heightened awareness to the scarcity of available assays and limited information on performance and reproducibility. To evaluate the immunogenicity of vaccines entering Phase I–III trials and to identify survivors, two enzyme-linked immunosorbent assays, the Filovirus Animal Non-Clinical Group assay and the Alpha Diagnostics International assay, were evaluated for detection of immunoglobulin G against Ebola virus glycoprotein. We found that the Filovirus Animal Nonclinical Group assay produced a wider range of relative antibody concentrations, higher assay precision, larger relative accuracy range, and lower regional background. Additionally, to sufficiently power a vaccine trial, use of the Filovirus Animal Nonclinical Group assay would require one third the number of participants than the Alpha Diagnostics International assay. This reduction in needed study participants will require less money, fewer man hours, and much less time to evaluate vaccine immunogenicity. PMID:29481881

Prostaglandin F2alpha-induced estrus in ewes exhibiting estrous cycles of different duration.

PubMed

Cárdenas, Horacio; Wiley, Todd M; Pope, William F

2004-07-01

Effects of prostaglandin F(2alpha) (PGF(2alpha)), administered during the mid-luteal phase of the estrous cycle, were examined in ewes exhibiting estrous cycles classified as short (< or =16.5 days, short-cycle ewes, n = 10) or long (> or =18 days, long-cycle ewes, n = 9) based on the durations of two estrous cycles (cycles -2 and -1) before treatment. The ewes received (i.m.) 20mg of PGF(2alpha) on day 10 of the third estrous cycle (cycle 0) followed, 36 h later, by 25 microg of gonadotropin releasing hormone (GnRH) to time the events of ovulation. Duration of subsequent estrous cycles +1 and +2 were recorded, and then the ewes were treated with the same combination of PGF(2alpha) and GnRH beginning on day 10 of estrous cycle +3. Ovaries were recovered 6h after GnRH administration to assess development of pre-ovulatory follicles. The proportion of ewes that exhibited estrus after PGF(2alpha) and GnRH treatment on cycle 0 was not different (P > 0.05) between short- and long-cycle ewes. Onset of estrus occurred sooner (P < 0.05) after PGF(2alpha) injection in short-cycle ewes than in long-cycle ewes (1.9 +/- 0.1 days and 2.3 +/- 0.1 days, duration of cycle 0 was 11.9 and 12.3 days, respectively). Duration of estrous cycle +1 was 1.2 days longer (P < 0.01) than cycle -1 in short-cycle ewes. However, duration of estrous cycle +1 did not change (P > 0.05) after PGF(2alpha) and GnRH administration in ewes having long cycles. Pre-ovulatory follicles did not differ (P > 0.05) in numbers, diameter, layers of granulosa cells nor concentrations of progesterone and estradiol-17beta in follicular fluid between short- and long-cycle ewes after PGF(2alpha) and GnRH treatment. In conclusion, ewes having short or long estrous cycles responded differently to PGF(2alpha) and GnRH treatment with respect to the interval to onset of estrus and duration of the subsequent estrous cycle.

Removal of Long-Lived Radon Daughters by Electropolishing Thin Layers of Stainless Steel

NASA Astrophysics Data System (ADS)

White, James; Schnee, Richard; Bunker, Raymond; Bowles, Michael; Cushman, Priscilla; Epland, Matthew; Pepin, Mark; Guiseppe, Vince

2012-10-01

Long-lived alpha and beta emitters in the Radon decay chain on detector surfaces may be limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. To screen detector surfaces for this radioactive contamination, a low-radiation, multi-wire proportional chamber (the BetaCage) is under construction. Removal of Pb-210 implanted on its 25-micron stainless steel wires without causing significant variation in the diameter of the wires is critical to the BetaCage's ultimate sensitivity. An apparatus to perform electropolishing trials to remove roughly a micron of material has been assembled. These trials have shown promising results. Stainless steel square samples implanted with Pb-210 have shown counts with a reduction factor greater than 10 after electropolishing according to gamma assay. Furthermore, alpha counting has produced similar results, with a reduction factor greater than 100. Lastly, the diameters of wires after electropolishing have remained sufficiently uniform, with reduction in thickness consistent with expectations.

Functional and Genomic Analyses of Alpha-Solenoid Proteins

PubMed Central

Fournier, David; Palidwor, Gareth A.; Shcherbinin, Sergey; Szengel, Angelika; Schaefer, Martin H.; Perez-Iratxeta, Carol; Andrade-Navarro, Miguel A.

2013-01-01

Alpha-solenoids are flexible protein structural domains formed by ensembles of alpha-helical repeats (Armadillo and HEAT repeats among others). While homology can be used to detect many of these repeats, some alpha-solenoids have very little sequence homology to proteins of known structure and we expect that many remain undetected. We previously developed a method for detection of alpha-helical repeats based on a neural network trained on a dataset of protein structures. Here we improved the detection algorithm and updated the training dataset using recently solved structures of alpha-solenoids. Unexpectedly, we identified occurrences of alpha-solenoids in solved protein structures that escaped attention, for example within the core of the catalytic subunit of PI3KC. Our results expand the current set of known alpha-solenoids. Application of our tool to the protein universe allowed us to detect their significant enrichment in proteins interacting with many proteins, confirming that alpha-solenoids are generally involved in protein-protein interactions. We then studied the taxonomic distribution of alpha-solenoids to discuss an evolutionary scenario for the emergence of this type of domain, speculating that alpha-solenoids have emerged in multiple taxa in independent events by convergent evolution. We observe a higher rate of alpha-solenoids in eukaryotic genomes and in some prokaryotic families, such as Cyanobacteria and Planctomycetes, which could be associated to increased cellular complexity. The method is available at http://cbdm.mdc-berlin.de/~ard2/. PMID:24278209

Cloning and Molecular Characterization of an Alpha-Glucosidase (MalH) from the Halophilic Archaeon Haloquadratum walsbyi.

PubMed

Cuebas-Irizarry, Mara F; Irizarry-Caro, Ricardo A; López-Morales, Carol; Badillo-Rivera, Keyla M; Rodríguez-Minguela, Carlos M; Montalvo-Rodríguez, Rafael

2017-11-21

We report the heterologous expression and molecular characterization of the first extremely halophilic alpha-glucosidase (EC 3.2.1.20) from the archaeon Haloquadratum walsbyi . A 2349 bp region ( Hqrw_2071 ) from the Hqr. walsbyi C23 annotated genome was PCR-amplified and the resulting amplicon ligated into plasmid pET28b(+), expressed in E. coli Rosetta cells, and the resulting protein purified by Ni-NTA affinity chromatography. The recombinant protein showed an estimated molecular mass of 87 kDa, consistent with the expected value of the annotated protein, and an optimal activity for the hydrolysis of α-PNPG was detected at 40 °C, and at pH 6.0. Enzyme activity values were the highest in the presence of 3 M NaCl or 3-4 M KCl. However, specific activity values were two-fold higher in the presence of 3-4 M KCl when compared to NaCl suggesting a cytoplasmic localization. Phylogenetic analyses, with respect to other alpha-glucosidases from members of the class Halobacteria, showed that the Hqr. walsbyi MalH was most similar (up to 41%) to alpha-glucosidases and alpha-xylosidases of Halorubrum . Moreover, computational analyses for the detection of functional domains, active and catalytic sites, as well as 3D structural predictions revealed a close relationship with an E. coli YicI-like alpha-xylosidase of the GH31 family. However, the purified enzyme did not show alpha-xylosidase activity. This narrower substrate range indicates a discrepancy with annotations from different databases and the possibility of specific substrate adaptations of halophilic glucosidases due to high salinity. To our knowledge, this is the first report on the characterization of an alpha-glucosidase from the halophilic Archaea, which could serve as a new model to gain insights into carbon metabolism in this understudied microbial group.

Enzyme replacement therapy in alpha-mannosidosis guinea-pigs.

PubMed

Crawley, Allison C; King, Barbara; Berg, Thomas; Meikle, Peter J; Hopwood, John J

2006-01-01

alpha-Mannosidosis is a lysosomal storage disorder caused by deficient activity of lysosomal alpha-mannosidase and is characterised by massive accumulation of mannose-containing oligosaccharides in affected individuals. Patients develop behaviour and learning difficulties, skeletal abnormalities, immune deficiency and hearing impairment. Disease in alpha-mannosidosis guinea-pigs resembles the clinical, histopathological, biochemical and molecular features of the human disease. We have used the guinea-pig model to investigate efficacy of enzyme replacement therapy as a treatment for alpha-mannosidosis. Intravenous recombinant human lysosomal alpha-mannosidase, administered at a dose of 1mg/kg, was cleared from circulation with a half-life of 53 h, with significant enzyme activity (1.4x normal levels) detected in circulation one week post-injection. alpha-Mannosidase administered to alpha-mannosidosis guinea-pigs at 1mg/kg (onset at birth or approximately 30 days) and 10mg/kg (at birth) was distributed widely amongst tissues, including to capillary depleted brain. By monitoring with tandem mass spectrometry, enzyme replacement therapy was found to be effective in reducing stored substrates in peripheral tissues at both dose rates, and in brain by up to 39% at the 10mg/kg dose, compared with untreated alpha-mannosidosis controls. Reductions of up to 60% of urinary mannose containing oligosaccharides were also observed. No histological improvements were seen in the brain at either dose, however marked decreases in lysosomal vacuolation in liver, kidney, spleen and endocrine pancreas, as well as a significant reduction in trigeminal ganglion neurons were observed. Multiple injections of 1mg/kg recombinant enzyme in alpha-mannosidosis guinea-pigs induced a very rapid humoral immune response precluding long-term intravenous treatment.

Antibody modified gold nano-mushroom arrays for rapid detection of alpha-fetoprotein.

PubMed

Li, Wanbo; Jiang, Xueqin; Xue, Jiancai; Zhou, Zhangkai; Zhou, Jianhua

2015-06-15

Localized surface plasmon resonance (LSPR) combined with immunoassay shows greatly potential in fast detection of tumor markers. In this paper, a highly sensitive LSPR substrate has been fabricated and modified for direct detection of alpha-fetoprotein (AFP). The biosensor was prepared by interference lithography, and modified by covalently immobilizing anti-AFP on the surface of gold nano-mushroom arrays (GNMA). The modification process was investigated by Vis-NIR reflectance spectra and cyclic voltammogram measurements. We revealed the optical properties of the modified GNMA by measuring the Vis-NIR reflectance spectra and simulating its electric intensity field distribution under light illumination. The GNMA substrate was highly sensitive, with a refractive index sensitivity of ~465 nm/RIU. The substrate can be applied to label-free detection of AFP, with the linear range and the limit of detection determined to be 20-200 ng/mL and 24 ng/mL (S/N=3), respectively. We also demonstrated its clinical application by directly detecting AFP in human serum samples. It is expected that our biosensor could be integrated on microfluidic chips for high-throughput detection in portable early diagnosis, post-operative and point-of-care (POC) in clinical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Human exposure to power frequency magnetic fields up to 7.6 mT: An integrated EEG/fMRI study.

PubMed

Modolo, Julien; Thomas, Alex W; Legros, Alexandre

2017-09-01

We assessed the effects of power-line frequency (60 Hz in North America) magnetic fields (MF) in humans using simultaneous electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Twenty-five participants were enrolled in a pseudo-double-blind experiment involving "real" or "sham" exposure to sinusoidal 60 Hz MF exposures delivered using the gradient coil of an MRI scanner following two conditions: (i) 10 s exposures at 3 mT (10 repetitions); (ii) 2 s exposures at 7.6 mT (100 repetitions). Occipital EEG spectral power was computed in the alpha range (8-12 Hz, reportedly the most sensitive to MF exposure in the literature) with/without exposure. Brain functional activation was studied using fMRI blood oxygen level-dependent (BOLD, inversely correlated with EEG alpha power) maps. No significant effects were detected on occipital EEG alpha power during or post-exposure for any exposure condition. Consistent with EEG results, no effects were observed on fMRI BOLD maps in any brain region. Our results suggest that acute exposure (2-10 s) to 60 Hz MF from 3 to 7.6 mT (30,000 to 76,000 times higher than average public exposure levels for 60 Hz MF) does not induce detectable changes in EEG or BOLD signals. Combined with previous findings in which effects were observed on the BOLD signal after 1 h exposure to 3 mT, 60 Hz MF, this suggests that MF exposure in the low mT range (<10 mT) might require prolonged durations of exposure to induce detectable effects. Bioelectromagnetics. 38:425-435, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Self-Gravitating Fundamental Strings and Black Holes

NASA Technical Reports Server (NTRS)

Damour, T.; Veneziano, G.

1999-01-01

The configuration of typically highly excited M much greater than M(sub s) which is approximately equal to alpha(prime) to the 1/2 power string states is considered as the string coupling g is adiabatically increased. The size distribution of very massive single string states is studied and the mass shift, due to a long-range gravitational, dilatonic, and axionic attraction, is estimated.

Long-term safety and efficacy of enzyme replacement therapy for Fabry disease.

PubMed

Wilcox, William R; Banikazemi, Maryam; Guffon, Nathalie; Waldek, Stephen; Lee, Philip; Linthorst, Gabor E; Desnick, Robert J; Germain, Dominique P

2004-07-01

Elsewhere, we reported the safety and efficacy results of a multicenter phase 3 trial of recombinant human alpha -galactosidase A (rh-alpha GalA) replacement in patients with Fabry disease. All 58 patients who were enrolled in the 20-wk phase 3 double-blind, randomized, and placebo-controlled study received subsequently 1 mg/kg of rh-alpha GalA (agalsidase beta, Fabrazyme, Genzyme Corporation) biweekly in an ongoing open-label extension study. Evidence of long-term efficacy, even in patients who developed IgG antibodies against rh- alpha GalA, included the continuously normal mean plasma globotriaosylceramide (GL-3) levels during 30 mo of the extension study and the sustained capillary endothelial GL-3 clearance in 98% (39/40) of patients who had a skin biopsy taken after treatment for 30 mo (original placebo group) or 36 mo (original enzyme-treated group). The mean serum creatinine level and estimated glomerular filtration rate also remained stable after 30-36 mo of treatment. Infusion-associated reactions decreased over time, as did anti-rh- alpha GalA IgG antibody titers. Among seroconverted patients, after 30-36 mo of treatment, seven patients tolerized (no detectable IgG antibody), and 59% had > or =4-fold reductions in antibody titers. As of 30 mo into the extension trial, three patients were withdrawn from the study because of positive serum IgE or skin tests; however, all have been rechallenged successfully at the time of this report. Thus, enzyme replacement therapy for 30-36 mo with agalsidase beta resulted in continuously decreased plasma GL-3 levels, sustained endothelial GL-3 clearance, stable kidney function, and a favorable safety profile.

Stuck in default mode: inefficient cross-frequency synchronization may lead to age-related short-term memory decline.

PubMed

Pinal, Diego; Zurrón, Montserrat; Díaz, Fernando; Sauseng, Paul

2015-04-01

Aging-related decline in short-term memory capacity seems to be caused by deficient balancing of task-related and resting state brain networks activity; however, the exact neural mechanism underlying this deficit remains elusive. Here, we studied brain oscillatory activity in healthy young and old adults during visual information maintenance in a delayed match-to-sample task. Particular emphasis was on long range phase:amplitude coupling of frontal alpha (8-12 Hz) and posterior fast oscillatory activity (>30 Hz). It is argued that through posterior fast oscillatory activity nesting into the excitatory or the inhibitory phase of frontal alpha wave, long-range networks can be efficiently coupled or decoupled, respectively. On the basis of this mechanism, we show that healthy, elderly participants exhibit a lack of synchronization in task-relevant networks while maintaining synchronized regions of the resting state network. Lacking disconnection of this resting state network is predictive of aging-related short-term memory decline. These results support the idea of inefficient orchestration of competing brain networks in the aging human brain and identify the neural mechanism responsible for this control breakdown. Copyright © 2015 Elsevier Inc. All rights reserved.

Double helix boron-10 powder thermal neutron detector

DOEpatents

Wang, Zhehui; Morris, Christopher L.; Bacon, Jeffrey D.

2015-06-02

A double-helix Boron-10 powder detector having intrinsic thermal neutron detection efficiency comparable to 36'' long, 2-in diameter, 2-bar Helium-3 detectors, and which can be used to replace such detectors for use in portal monitoring, is described. An embodiment of the detector includes a metallic plate coated with Boron-10 powder for generating alpha and Lithium-7 particles responsive to neutrons impinging thereon supported by insulators affixed to at least two opposing edges; a grounded first wire wound in a helical manner around two opposing insulators; and a second wire having a smaller diameter than that of the first wire, wound in a helical manner around the same insulators and spaced apart from the first wire, the second wire being positively biased. A gas, disposed within a gas-tight container enclosing the plate, insulators and wires, and capable of stopping alpha and Lithium-7 particles and generating electrons produces a signal on the second wire which is detected and subsequently related to the number of neutrons impinging on the plate.

Molecular characterization of variant alpha-subunit of electron transfer flavoprotein in three patients with glutaric acidemia type II--and identification of glycine substitution for valine-157 in the sequence of the precursor, producing an unstable mature protein in a patient.

PubMed Central

Indo, Y; Glassberg, R; Yokota, I; Tanaka, K

1991-01-01

In our previous study of eight glutaric acidemia type II (GAII) fibroblast lines by using [35S]methionine labeling and immunoprecipitation, three of them had a defect in the synthesis of the alpha-subunit of electron transfer flavoprotein (alpha-ETF) (Ikeda et al. 1986). In one of them (YH1313) the labeling of the mature alpha-ETF was barely detectable, while that of the precursor (p) was stronger. In another (YH605) no synthesis of immunoreactive p alpha-ETF was detectable. In the third cell line (YH1391) the rate of variant p alpha-ETF synthesis was comparable to normal, but its electrophoretic mobility was slightly faster than normal. In the present study, the northern blot analysis revealed that all three mutant cell lines contained p alpha-ETF mRNA and that their size and amount were comparable to normal. In immunoblot analysis, both alpha- and beta-ETF bands were barely detectable in YH1313 and YH605 but were detectable in YH1391 in amounts comparable to normal. Sequencing of YH1313 p alpha-ETF cDNA via PCR identified a transversion of T-470 to G. We then devised a simple PCR method for the 119-bp section (T-443/G-561) for detecting this mutation. In the upstream primer, A-466 was artificially replaced with C, to introduce a BstNI site into the amplified copies in the presence of G-470 from the variant sequence. The genomic DNA analysis using this method demonstrated that YH1313 was homozygous for T----G-470 transversion. It was not detected either in two other alpha-ETF-deficient GAII or in seven control cell lines. The alpha-ETF cDNA sequence in YH605 was identical to normal. Images Figure 1 Figure 2 Figure 3 Figure 5 PMID:1882842

Detection of Polonium-210 on Spirit Dust Magnets and Implications for the Global Martian Dust Cycle

NASA Astrophysics Data System (ADS)

Wong, R.; Meslin, P.; Sabroux, J.; Madsen, M. B.; Pineau, J.; Richon, P.

2013-12-01

The radioactivity of airborne aerosols, which originates from the attachment of radionuclides produced by radon disintegration, Galactic Cosmic Rays (GCR) or anthropogenic activities, especially fallouts from nuclear weapons testing, can be used to measure the residence time of these aerosols in the atmosphere and their deposition rate. It is also used to characterize soils erosion rates (Matissof et al., 2002) or to investigate the origin of desert rock varnish (Hodge et al., 2005), to name only a few terrestrial applications. A translation of these nuclear methods to the Martian atmosphere, which is characterized by a very active dust cycle, is tempting, and has the potential to offer a unique insight into the present-day recycling of the Martian surface. This approach is made possible by two facts: 1) the presence of radon in the Martian atmosphere, which produces long-lived radioactive decay products, in particular polonium-210, and whose abundance can be indirectly inferred by gamma ray spectrometry from orbit using Mars Odyssey Gamma Ray Spectrometer (GRS) (Meslin et al., 2012); 2) the presence at the surface of Mars of two Alpha Particle X-Ray Spectrometers (APXS), onboard Opportunity and Spirit Mars Exploration Rovers, whose energy range (in the alpha mode) very fortuitously happens to include the energy of alpha particles emitted by the decay of polonium-210. The long half-life of this radionuclide is such that it is almost entirely attached to the particles that have been in suspension in the atmosphere, especially those characterized by a large specific surface area or by a long atmospheric residence time. It can therefore be used as a tracer of the dust cycle. An analysis of the alpha spectra acquired on the dust Capture and Filter magnets of the Spirit rover confirms results obtained by Meslin et al. (2006) that the Martian dust is radioactive w/r to polonium-210, thereby extending Opportunity's result to a global scale. This result enables us to derive an estimate of the effective thickness of the dust reservoir that is involved in the present-day Mars atmospheric cycle. Differences between 210Po activities measured at Gusev and Meridiani Planum could be indicative of different dust transport histories and/or physical properties, possibly related to the differences in brightness/mineralogy/composition already noted on the dust magnets at the two sites (Madsen et al., 2009). The dust coating of rocks, on the other hand, does not show any detectable 210Po signal, which suggests that these dust particles are not as easily mobilized and have not been as much involved in the present-day atmospheric cycle. Finally, a new upper limit of radon near-surface concentration has been derived. Hodge, V. F., et al. (2005), J. Env. Radioactivity, 78, 331-342. Madsen, M.B., et al. (2009), J. Geophys. Res., 114, E06S90. Matissof, G., et al. (2002), Journal Environ. Qual., 31, 54-61. Meslin, P.-Y., et al. (2006), J. Geophys. Res., 111, E09012. Meslin, P.-Y., et al. (2012), 43rd LPSC, abstr. #2852.

Mid Infrared Hydrogen Recombination Line Emission from the Maser Star MWC 349A

NASA Technical Reports Server (NTRS)

Smith, Howard A.; Strelnitski, V.; Miles, J. W.; Kelly, D. M.; Lacy, J. H.

1997-01-01

We have detected and spectrally resolved the mid-IR hydrogen recombination lines H6(alpha)(12.372 micrometers), H7(alpha)(19.062 micrometers), H7(beta)(l1.309 micrometers) and H8(gamma)(12.385 micrometers) from the star MWC349A. This object has strong hydrogen maser emission (reported in the millimeter and submillimeter hydrogen recombination lines from H36(alpha) to H21(alpha)) and laser emission (reported in the H15(alpha), H12(alpha) and H10(alpha) lines). The lasers/masers are thought to arise predominantly in a Keplerian disk around the star. The mid-IR lines do not show evident signs of lasing, and can be well modeled as arising from the strong stellar wind, with a component arising from a quasi-static atmosphere around the disk, similar to what is hypothesized for the near IR (less than or equal to 4 micrometers) recombination lines. Since populations inversions in the levels producing these mid-IR transitions are expected at densities up to approximately 10(exp 11)/cu cm, these results imply either that the disk does not contain high-density ionized gas over long enough path lengths to produce a gain approximately 1, and/or that any laser emission from such regions is small compared to the spontaneous background emission from the rest of the source as observed with a large beam. The results reinforce the interpretation of the far-IR lines as true lasers.

An Alpha Proton X-Ray Spectrometer for Mars-96 and Mars Pathfinder

NASA Astrophysics Data System (ADS)

Rieder, R.; Wanke, H.; Economou, T.

1996-09-01

Mars Pathfinder and the Russian Mars-96 will carry an Alpha Proton X-Ray Spectrometer (APXS) for the determination of the chemical composition of Martian rocks and soil. The instrument will measure the concentration of all major and many minor elements, including C,N and O, at levels above typically 1%. The method employed consist of bombarding a sample of 50 mm diameter with alpha particles from a radioactive source (50 mCi of Cm-244) and measuring: (i) backscattered alpha particles (alpha mode) (ii) protons from (a,p) reactions with some light elements (proton mode) (iii) characteristic X-rays emitted from the sample (X-ray mode). The APXS has a long standing space heritage, going back to Surveyor V,VI and VII (1967/68) and the Soviet Phobos (1988) missions. The present design is the result of an endeavour to reduce mass and power consumption to 600g/ 300mW. It consist of a sensor head containing the alpha sources, a telescope of a silicon detectors for the detection of the alpha particles and protons and a separate X-ray detector with its preamplifier, and an electronics box (80x70x60 mm) containing a microcontroller based multichannel spectrometer. The paper will describe the APXS flight hardware and present results obtained with the flight instrument that will show the instrument capabili- ties and the expected results to be obtained during surface operations on Mars.

Detection of cat-eye effect echo based on unit APD

NASA Astrophysics Data System (ADS)

Wu, Dong-Sheng; Zhang, Peng; Hu, Wen-Gang; Ying, Jia-Ju; Liu, Jie

2016-10-01

The cat-eye effect echo of optical system can be detected based on CCD, but the detection range is limited within several kilometers. In order to achieve long-range even ultra-long-range detection, it ought to select APD as detector because of the high sensitivity of APD. The detection system of cat-eye effect echo based on unit APD is designed in paper. The implementation scheme and key technology of the detection system is presented. The detection performances of the detection system including detection range, detection probability and false alarm probability are modeled. Based on the model, the performances of the detection system are analyzed using typical parameters. The results of numerical calculation show that the echo signal-to-noise ratio is greater than six, the detection probability is greater than 99.9% and the false alarm probability is less tan 0.1% within 20 km detection range. In order to verify the detection effect, we built the experimental platform of detection system according to the design scheme and carry out the field experiments. The experimental results agree well with the results of numerical calculation, which prove that the detection system based on the unit APD is feasible to realize remote detection for cat-eye effect echo.

Quantum Dot-Induced Phase Stabilization of ..alpha..-CsPbI3 Perovskite for High-Efficiency Photovoltaics

DOE PAGES

Swarnkar, Abhishek; Marshall, Ashley R.; Sanehira, Erin M.; ...

2016-10-07

Here, we show nanoscale phase stabilization of CsPbI 3 quantum dots (QDs) to low temperatures that can be used as the active component of efficient optoelectronic devices. CsPbI 3 is an all-inorganic analog to the hybrid organic cation halide perovskites, but the cubic phase of bulk CsPbI3 (..alpha..-CsPbI 3) -- the variant with desirable band gap -- is only stable at high temperatures. We also describe the formation of ..alpha..-CsPbI 3 QD films that are phase-stable for months in ambient air. The films exhibit long-range electronic transport and were used to fabricate colloidal perovskite QD photovoltaic cells with an open-circuitmore » voltage of 1.23 volts and efficiency of 10.77%. Furthermore, these devices function as light-emitting diodes with low turn-on voltage and tunable emission.« less

Long-Range Correlation in alpha-Wave Predominant EEG in Human

NASA Astrophysics Data System (ADS)

Sharif, Asif; Chyan Lin, Der; Kwan, Hon; Borette, D. S.

2004-03-01

The background noise in the alpha-predominant EEG taken from eyes-open and eyes-closed neurophysiological states is studied. Scale-free characteristic is found in both cases using the wavelet approach developed by Simonsen and Nes [1]. The numerical results further show the scaling exponent during eyes-closed is consistently lower than eyes-open. We conjecture the origin of this difference is related to the temporal reconfiguration of the neural network in the brain. To further investigate the scaling structure of the EEG background noise, we extended the second order statistics to higher order moments using the EEG increment process. We found that the background fluctuation in the alpha-predominant EEG is predominantly monofractal. Preliminary results are given to support this finding and its implication in brain functioning is discussed. [1] A.H. Simonsen and O.M. Nes, Physical Review E, 58, 2779¡V2748 (1998).

First detection of winds in red giants by microwave continuum techniques

NASA Technical Reports Server (NTRS)

Drake, S. A.; Linsky, J. L.

1983-01-01

Eight red giants and supergiants have been observed at 4885 MHz (6 cm) with the Very Large Array in an attempt to detect continuum emission. The bright giant Alpha-1 Her (M5 II) was detected at an average flux density of 0.9 + or - 0.13 mJy. Since the likely source of this emission is an ionized, optically thick component of a stellar wind, this detection implies a mass loss rate of 2 x 10 to the -9th solar masses per yr for the ionized gas. The fraction of the outflow in Alpha-1 Her that is ionized (0.002-0.02) seems to be similar to that previously found for Alpha Ori and Alpha Sco A. Alpha Boo (K2 IIIp) and Beta Gem (K0 III) are probable and definite detections, respectively. The derived ionized mass loss rates for these two stars are about 1 x 10 to the -10th solar masses per yr, implying in the case of Alpha Boo that the wind is largely ionized.

Detection of Fast Moving and Accelerating Targets Compensating Range and Doppler Migration

DTIC Science & Technology

2014-06-01

Radon -Fourier transform has been introduced to realize long- term coherent integration of the moving targets with range migration [8, 9]. Radon ...2010) Long-time coherent integration for radar target detection base on Radon -Fourier transform, in Proceedings of the IEEE Radar Conference, pp...432–436. 9. Xu, J., Yu, J., Peng, Y. & Xia, X. (2011) Radon -Fourier transform for radar target detection, I: Generalized Doppler filter bank, IEEE

Flash Detection Efficiencies of Long Range Lightning Detection Networks During GRIP

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Bateman, Monte G.; Blakeslee, Richard J.

2012-01-01

We flew our Lightning Instrument Package (LIP) on the NASA Global Hawk as a part of the Genesis and Rapid Intensification Processes (GRIP) field program. The GRIP program was a NASA Earth science field experiment during the months of August and September, 2010. During the program, the LIP detected lighting from 48 of the 213 of the storms overflown by the Global Hawk. The time and location of tagged LIP flashes can be used as a "ground truth" dataset for checking the detection efficiency of the various long or extended range ground-based lightning detection systems available during the GRIP program. The systems analyzed included Vaisala Long Range (LR), Vaisala GLD360, the World Wide Lightning Location Network (WWLLN), and the Earth Networks Total Lightning Network (ENTLN). The long term goal of our research is to help understand the advantages and limitations of these systems so that we can utilize them for both proxy data applications and cross sensor validation of the GOES-R Geostationary Lightning Mapper (GLM) sensor when it is launched in the 2015 timeframe.

Reproducibility of African giant pouched rats detecting Mycobacterium tuberculosis.

PubMed

Ellis, Haylee; Mulder, Christiaan; Valverde, Emilio; Poling, Alan; Edwards, Timothy

2017-04-24

African pouched rats sniffing sputum samples provided by local clinics have significantly increased tuberculosis case findings in Tanzania and Mozambique. The objective of this study was to determine the reproducibility of rat results. Over an 18-month period 11,869 samples were examined by the rats. Intra-rater reliability was assessed through Yule's Q. Inter-rater reliability was assessed with Krippendorff's alpha. Intra-rater reliability was high, with a mean Yule's Q of 0.9. Inter-rater agreement was fair, with Krippendorf's alpha ranging from 0.15 to 0.45. Both Intra- and Inter-rater reliability was independent of the sex of the animals, but they were positively correlated with age. Both intra- and inter-rater agreement was lowest for samples designated as smear-negative by the clinics. Overall, the reproducibility of tuberculosis detection rat results was fair and diagnostic results were therefore independent of the rats used.

Spatial and Time Coincidence Detection of the Decay Chain of Short-Lived Radioactive Nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granja, Carlos; Jakubek, Jan; Platkevic, Michal

The quantum counting position sensitive pixel detector Timepix with per-pixel energy and time resolution enables to detect radioactive ions and register the consecutive decay chain by simultaneous position-and time-correlation. This spatial and timing coincidence technique in the same sensor is demonstrated by the registration of the decay chain {sup 8}He{yields}{sup {beta} 8}Li and {sup 8}Li{yields}{sup {beta}-} {sup 8}Be{yields}{alpha}+{alpha} and by the measurement of the {beta} decay half-lives. Radioactive ions, selectively obtained from the Lohengrin fission fragment spectrometer installed at the High Flux Reactor of the ILL Grenoble, are delivered to the Timepix silicon sensor where decays of the implanted ionsmore » and daughter nuclei are registered and visualized. We measure decay lifetimes in the range {>=}{mu}s with precision limited just by counting statistics.« less

Pregnancy outcomes and community health: the POUCH study of preterm delivery.

PubMed

Holzman, C; Bullen, B; Fisher, R; Paneth, N; Reuss, L

2001-07-01

In light of the social/ethnic disparity in preterm delivery (PTD) rates, the Pregnancy Outcomes and Community Health (POUCH) Study takes a broad view of the determinants of PTD by attempting to link underlying biological and psychosocial factors. The relationships between placental pathology, maternal biomarkers, and antecedent psychosocial factors are evaluated in three hypothesised pathways of PTD - one characterised primarily by infection, one by maternal vascular disease, and one by premature elevations in corticotropin releasing hormone in the absence of histological evidence of placental pathology. Within each pathway, an emphasis is placed on understanding the roles of stress and of maternal serum alpha-fetoprotein, an early biomarker associated with PTD. The POUCH Study enrolls pregnant women from five Michigan communities. Information about these women and their environments is gathered through detailed interviews and collection of biological samples including hair, urine, saliva, blood, vaginal fluid, and vaginal smear at 15-26 weeks of gestation. We have chosen to focus on the second trimester--a time when pathological processes may have evolved to a detectable stage, but generally before the onset of biological changes that accompany labour. This focus is consistent with the long-range goal of early detection/intervention and prevention of PTD.

Tertiary structure in N-linked oligosaccharides.

PubMed

Homans, S W; Dwek, R A; Rademacher, T W

1987-10-06

Distance constraints derived from two-dimensional nuclear Overhauser effect measurements have been used to define the orientation of the Man alpha 1-3Man beta linkage in seven different N-linked oligosaccharides, all containing the common pentasaccharide core Man alpha 1-6(Man alpha 1-3)Man beta 1-4GlcNAc beta 1-4GlcNAc. Conformational invariance of the Man alpha 1-3Man beta linkage was found for those structures bearing substitutions on the Man alpha 1-3Man beta antenna. However, the presence of either a GlcNAc residue in the beta 1-4 linkage to Man beta ("bisecting GlcNAc") or a xylose residue in the beta 1-2 linkage to Man beta of the trimannosyl core was found to generate conformational transitions that were similar. These transitions were accompanied by characteristic chemical shift perturbations of proton resonances in the vicinity of the Man alpha 1-3Man beta linkage. Molecular orbital energy calculations suggest that the conformational transition between the unsubstituted and substituted cores arises from energetic constraints in the vicinity of the Man alpha 1-3Man beta linkage, rather than specific long-range interactions. These data taken together with our previous results on the Man alpha 1-6Man beta linkage [Homans, S. W., Dwek R. A., Boyd, J., Mahmoudian, M., Richards, W. G., & Rademacher, T. W. (1986) Biochemistry 25, 6342] allow us to discuss the consequences of the modulation of oligosaccharide solution conformations.

Determination of metallic traces in kidneys, livers, lungs and spleens of rats with metallic implants after a long implantation time.

PubMed

Rubio, Juan Carlos; Garcia-Alonso, Maria Cristina; Alonso, Concepcion; Alobera, Miguel Angel; Clemente, Celia; Munuera, Luis; Escudero, Maria Lorenza

2008-01-01

Metallic transfer from implants does not stop at surrounding tissues, and metallic elements may be transferred by proteins to become lodged in organs far from the implant. This work presents an in vivo study of metallic implant corrosion to measure metallic element accumulation in organs located far from the implant, such as kidneys, livers, lungs and spleens. The studied metallic implant materials were CoCr alloy, Ti, and the experimental alloy MA956 coated with alpha-alumina. The implants were inserted in the hind legs of Wistar rats. Analysis for Co, Cr, Ti and Al metallic traces was performed after a long exposure time of 12 months by Inductively Coupled Plasma (ICP) with Mass Spectrometry (MS). According to the results, the highest Cr and Ti concentrations were detected in spleens. Co is mainly found in kidneys, since this element is eliminated via urine. Cr and Ti traces increased significantly in rat organs after the long implantation time. The organs of rats implanted with the alpha-alumina coated experimental MA956 did not present any variation in Al content after 12 months, which means there was no degradation of the alumina layer surface.

Location, Characterization and Quantification of Hydroacoustic Signals in the Indian Ocean

DTIC Science & Technology

2004-10-01

and P-F Piserchia, Long range detection of hydroacoustic signals from large Icebergs in the Ross Sea, Antarctica, Ear. and Plan. Sci. Let., 203:519...Bohnenstiehl, and E. Chapp, Long Range Acoustic Propagation of High Frequency Energy in the Indian Ocean from Icebergs and Earthquakes, 26* Seismic...calculated for each hydrophone site in the Indian Ocean, which assists in understanding detection thresholds for each station at a range of frequencies

Acoustic and Visual Monitoring for Marine Mammals at the Southern California Off-Shore Range (SCORE)

DTIC Science & Technology

2005-02-28

1998 ). Long - range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean. Journal of the Acoustical ...C. G. and Clark, D.S. 1998 . Long - range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean, J. Acous. Soc. Am...Gulf of Alaska. Marine Mammal Science 19: 682-693. Stafford , K.M., C.G. Fox, and D.S. Clark. 1998 .

Organic electrochemical transistor based immunosensor for prostate specific antigen (PSA) detection using gold nanoparticles for signal amplification.

PubMed

Kim, Duck-Jin; Lee, Nae-Eung; Park, Joon-Shik; Park, In-Jun; Kim, Jung-Gu; Cho, Hyoung J

2010-07-15

We demonstrated a highly sensitive organic electrochemical transistor (OECT) based immunosensor with a low detection limit for prostate specific antigen/alpha1-antichymotrypsin (PSA-ACT) complex. The poly(styrenesulfonate) doped poly(3,4-ethylenedioxythiophene) (PEDOT:PSS) based OECT with secondary antibody conjugated gold nanoparticles (AuNPs) provided a detection limit of the PSA-ACT complex as low as 1pg/ml, as well as improved sensitivity and a dynamic range, due to the role of AuNPs in the signal amplification. The sensor performances were particularly improved in the lower concentration range where the detection is clinically important for the preoperative diagnosis and screening of prostate cancer. This result shows that the OECT-based immunosensor can be used as a transducer platform acceptable to the point-of-care (POC) diagnostic systems and demonstrates adaptability of organic electronics to clinical applications. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Magnetofluorescent nanocomposites and quantum dots used for optimal application in magnetic fluorescence-linked immunoassay.

PubMed

Tsai, H Y; Li, S Y; Fuh, C Bor

2018-03-01

Magnetofluorescent nanocomposites with optimal magnetic and fluorescent properties were prepared and characterized by combining magnetic nanoparticles (iron oxide@polymethyl methacrylate) with fluorescent nanoparticles (rhodamine 6G@mSiO 2 ). Experimental parameters were optimized to produce nanocomposites with high magnetic susceptibility and fluorescence intensity. The detection of a model biomarker (alpha-fetoprotein) was used to demonstrate the feasibility of applying the magnetofluorescent nanocomposites combined with quantum dots and using magnetic fluorescence-linked immunoassay. The magnetofluorescent nanocomposites enable efficient mixing, fast re-concentration, and nanoparticle quantization for optimal reactions. Biofunctional quantum dots were used to confirm the alpha-fetoprotein (AFP) content in sandwich immunoassay after mixing and washing. The analysis time was only one third that required in ELISA. The detection limit was 0.2 pg mL -1 , and the linear range was 0.68 pg mL -1 -6.8 ng mL -1 . This detection limit is lower, and the linear range is wider than those of ELISA and other methods. The measurements made using the proposed method differed by less than 13% from those obtained using ELISA for four AFP concentrations (0.03, 0.15, 0.75, and 3.75 ng mL -1 ). The proposed method has a considerable potential for biomarker detection in various analytical and biomedical applications. Graphical abstract Magnetofluorescent nanocomposites combined with fluorescent quantum dots were used in magnetic fluorescence-linked immunoassay.

Improved localization of cellular membrane receptors using combined fluorescence microscopy and simultaneous topography and recognition imaging.

PubMed

Duman, M; Pfleger, M; Zhu, R; Rankl, C; Chtcheglova, L A; Neundlinger, I; Bozna, B L; Mayer, B; Salio, M; Shepherd, D; Polzella, P; Moertelmaier, M; Kada, G; Ebner, A; Dieudonne, M; Schütz, G J; Cerundolo, V; Kienberger, F; Hinterdorfer, P

2010-03-19

The combination of fluorescence microscopy and atomic force microscopy has a great potential in single-molecule-detection applications, overcoming many of the limitations coming from each individual technique. Here we present a new platform of combined fluorescence and simultaneous topography and recognition imaging (TREC) for improved localization of cellular receptors. Green fluorescent protein (GFP) labeled human sodium-glucose cotransporter (hSGLT1) expressed Chinese Hamster Ovary (CHO) cells and endothelial cells (MyEnd) from mouse myocardium stained with phalloidin-rhodamine were used as cell systems to study AFM topography and fluorescence microscopy on the same surface area. Topographical AFM images revealed membrane features such as lamellipodia, cytoskeleton fibers, F-actin filaments and small globular structures with heights ranging from 20 to 30 nm. Combined fluorescence and TREC imaging was applied to detect density, distribution and localization of YFP-labeled CD1d molecules on alpha-galactosylceramide (alphaGalCer)-loaded THP1 cells. While the expression level, distribution and localization of CD1d molecules on THP1 cells were detected with fluorescence microscopy, the nanoscale distribution of binding sites was investigated with molecular recognition imaging by using a chemically modified AFM tip. Using TREC on the inverted light microscope, the recognition sites of cell receptors were detected in recognition images with domain sizes ranging from approximately 25 to approximately 160 nm, with the smaller domains corresponding to a single CD1d molecule.

The Remote Detection of Alpha-Radioactive Nucleus Decay

NASA Astrophysics Data System (ADS)

Gurkovskiy, Boris; Miroshnichenko, Vladimir; Onishchenko, Evgeny; Simakov, Andrey; Streil, Thomas

Results of the new device design for the alpha-radiation remote detection are presented. Negative ions from the alpha particle tracks are detected by the discharge wire counter opened to air. Ion clusters being transferred from the particle tracks to the detector volume by an air flux. The detector works in a counting mode that provides sharp selectivity and accuracy of measurements. The basic parameters of the device are: detecting distance -0.5 m; measurement time -30 s; the square sensitivity -0.05 Bq/cm2.

KECK SPECTROSCOPY OF FAINT 3 < z < 8 LYMAN BREAK GALAXIES: EVIDENCE FOR A DECLINING FRACTION OF EMISSION LINE SOURCES IN THE REDSHIFT RANGE 6 < z < 8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schenker, Matthew A.; Ellis, Richard S.; Robertson, Brant E.

2012-01-10

Using deep Keck spectroscopy of Lyman break galaxies selected from infrared imaging data taken with the Wide Field Camera 3 on board the Hubble Space Telescope, we present new evidence for a reversal in the redshift-dependent fraction of star-forming galaxies with detectable Lyman alpha (Ly{alpha}) emission in the redshift range 6.3 < z < 8.8. Our earlier surveys with the DEIMOS spectrograph demonstrated a significant increase with redshift in the fraction of line emitting galaxies over the interval 4 < z < 6, particularly for intrinsically faint systems which dominate the luminosity density. Using the longer wavelength sensitivities of Lowmore » Resolution Imaging Spectrometer and NIRSPEC, we have targeted 19 Lyman break galaxies selected using recent WFC3/IR data whose photometric redshifts are in the range 6.3 < z < 8.8 and which span a wide range of intrinsic luminosities. Our spectroscopic exposures typically reach a 5{sigma} sensitivity of <50 A for the rest-frame equivalent width (EW) of Ly{alpha} emission. Despite the high fraction of emitters seen only a few hundred million years later, we find only two convincing and one possible line emitter in our more distant sample. Combining with published data on a further seven sources obtained using FORS2 on the ESO Very Large Telescope, and assuming continuity in the trends found at lower redshift, we discuss the significance of this apparent reversal in the redshift-dependent Ly{alpha} fraction in the context of our range in continuum luminosity. Assuming all the targeted sources are at their photometric redshift and our assumptions about the Ly{alpha} EW distribution are correct, we would expect to find so few emitters in less than 1% of the realizations drawn from our lower redshift samples. Our new results provide further support for the suggestion that, at the redshifts now being probed spectroscopically, we are entering the era where the intergalactic medium is partially neutral. With the arrival of more sensitive multi-slit infrared spectrographs, the prospects for improving the statistical validity of this result are promising.« less

Development of a three-layer phoswich alpha-beta-gamma imaging detector

NASA Astrophysics Data System (ADS)

Yamamoto, Seiichi; Ishibashi, Hiroyuki

2015-06-01

For radiation monitoring at the sites of such nuclear power plant accidents as Fukushima Daiichi, radiation detectors are needed not only for gamma photons but also for alpha and beta particles because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. In some applications, imaging detectors are required to detect the distribution of plutonium particles that emit alpha particles and radiocesium in foods that emits beta particles and gamma photons. To solve these requirements, we developed an imaging detector that can measure the distribution of alpha and beta particles as well as gamma photons. The imaging detector consists of three-layer scintillators optically coupled to each other and to a position sensitive photomultiplier tube (PSPMT). The first layer, which is made of a thin plastic scintillator (decay time: 5 ns), detects alpha particles. The second layer, which is made of a thin Gd2SiO5 (GSO) scintillator with 1.5 mol% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol% Ce (decay time: 70 ns) detects gamma photons. Using pulse shape discrimination, the images of these layers can be separated. The position information is calculated by the Anger principle from 8×8 anode signals from the PSPMT. The images for the alpha and beta particles and the gamma photons are individually formed by the pulse shape discriminations for each layer. We detected alpha particle images in the first layer and beta particle images in the second layer. Gamma photon images were detected in the second and third layers. The spatial resolution for the alpha and beta particles was 1.25 mm FWHM and less than 2 mm FWHM for the gamma photons. We conclude that our developed alpha-beta-gamma imaging detector is promising for imaging applications not only for the environmental monitoring of radionuclides but also for medical and molecular imaging.

Time-resolved FT EPR and optical spectroscopy study on photooxidation of aliphatic alpha-amino acids in aqueous solutions; electron transfer from amino vs carboxylate functional group.

PubMed

Tarabek, Peter; Bonifacić, Marija; Beckert, Dieter

2006-06-08

Using time-resolved Fourier transform electron paramagnetic resonance, FT EPR, and optical spectroscopy, the photooxidation of glycine, alpha-alanine, alpha-aminoisobutyric acid, and model compounds beta-alanine, methylamine and sodium acetate, by excited triplets of anthraquinone-2,6-disulfonate dianion was studied in aqueous solutions in the pH range 5-13. Anthraquinone radical trianions showing strong emissive spin-polarization (CIDEP) were formed, indicating fast electron transfer from the quenchers to the spin-polarized quinone triplet as the primary reaction. None of the primary radicals formed upon one-electron oxidation of quenchers could be detected at the nanosecond time scale of FT EPR measurements because of their very fast transformation into secondary products. The latter were identified to be decarboxylated alpha-aminoalkyl radicals for alpha-amino acids anions and zwitterions, beta-aminoalkyl radicals for beta-alanine zwitterions, and methyl radicals for acetate anions; corresponding aminyl radicals were the first EPR detectable products from beta-alanine anions and methylamine. Thus, anthraquinone-2,6-disulfonate triplet can take an electron from both NH(2)- and -CO(2)(-) functional groups forming aminium ((+*)NH(2)-) and acyloxyl (-CO(2)(*)) radicals, respectively. Aminium radicals derived from beta-alanine anions and CH(3)-NH(2) stabilize by deprotonation into aminyl radicals, whereas these derived from alpha-amino acids anions are known to suffer ultrafast decarboxylation (tau approximately 10 ps). Analysis of the polarization patterns revealed that decarboxylation from acyloxyl radicals are considerably slower (ns < tau < 0.1 micros). Therefore, in the case of alpha-amino acids, the isoelectronic structures NH(2)-CR(2)-CO(2)(*) and (+*)NH(2)-CR(2)-CO(2)(-) probably do not constitute resonance mesomeric forms of one and the same species and the decarboxylation of aminium radicals is not preceded by the intramolecular carboxylate to amino group electron transfer. Absolute triplet quenching rate constants at zero ionic strength were in the range of 2 x 10(8) to 2 x 10(9) M(-1) s(-1) for R-NH(2) and 2 x 10(7) to 10(8) M(-1) s(-1) for R-CO(2)(-) type of electron donors, reflecting in principle their standard reduction potentials. The strengths of acids: (+)NH(3)-(*)CH(2), (+)NH(3)-(*)C(CH(3))H, and (+)NH(3)-(*)C(CH(3))(2), pK(a) <4, >6, and >7, respectively, were found to be remarkably strongly dependent on alpha-C substitution. The conjugate bases of these alpha-aminoalkyl radicals reduce anthraquinone-2,6-disulfonate dianion ground state with k(sec) = 3 x 10(9) M(-1) s(-1).

Detection of 210Po on filter papers 16 years after use for the collection of short-lived radon progeny in a room.

PubMed

Abu-Jarad, F; Fazal-ur-Rehman

2003-01-01

Radon gas was allowed to accumulate in its radium source and then injected into a 36 m(3) test room, resulting in an initial radon concentration of 15 kBq m(-3). Filter papers were used to collect the short-lived radon progeny and thus to measure the Potential Alpha Energy Concentration (PAEC) in-situ in the year 1984 at different times and conditions according to the experimental design. The radon progeny collected on the filter papers were studied as a function of aerosol particle concentration ranging from 10(2)-10(5) particles cm(-3) in three different experiments. The highest aerosol particle concentration was generated by indoor cigarette smoking. Those filters were stored after the experiment, and were used after 16 years to study the activity of the radon long-lived alpha emitter progeny, (210)Po (T(1/2)=138 days). This isotope is separated from the short-lived progeny by (210)Pb beta emitter with 22.3 years half-life. After 16 years' storage of these filters, each filter paper was sandwiched and wrapped between two CR-39 nuclear track detectors, to put the detectors in contact with the surfaces of different filters, for 337 days. Correlation between the PAEC measured using filter papers in the year 1984 and the activity of long-lived alpha emitter (210)Po on the same filter papers measured in the year 2000 were studied. The results of the (210)Po activity showed a very good correlation of 0.92 with the PAEC 16 years ago. The results also depict that the PAEC and (210)Po activity in indoor air increased with the increase of aerosol particle concentration, which shows the attachment of short-lived radon progeny with the aerosol particles. The experiment proves that indoor cigarette smoking is a major source of aerosol particles carrying radon progeny and, thus, indoor cigarette smoking is an additional source of internal radiation hazard to the occupants whether smoker or non-smoker.

Emergence of Alpha and Gamma Like Rhythms in a Large Scale Simulation of Interacting Neurons

NASA Astrophysics Data System (ADS)

Gaebler, Philipp; Miller, Bruce

2007-10-01

In the normal brain, at first glance the electrical activity appears very random. However, certain frequencies emerge during specific stages of sleep or between quiet wake states. This raises the question of whether current mathematical and computational models of interacting neurons can display similar behavior. A recent model developed by Eugene Izhikevich appears to succeed. However, early dynamical simulations used to detect these patterns were possibly compromised by an over-simplified initial condition and evolution algorithm. Utilizing the same model, but a more robust algorithm, here we present our initial results, showing that these patterns persist under a wide range of initial conditions. We employ spectral analysis of the firing patterns of a system of interacting excitatory and inhibitory neurons to demonstrate a bimodal spectrum centered on two frequencies in the range characteristic of alpha and gamma rhythms in the human brain.

Gene polymorphisms of TNF-alpha-308 (G/A), IL-10(-1082) (G/A), IL-6(-174) (G/C) and IL-1Ra (VNTR) in Egyptian cases with type 1 diabetes mellitus.

PubMed

Settin, Ahmad; Ismail, Azza; El-Magd, Megahed Abo; El-Baz, Rizk; Kazamel, Amira

2009-01-01

Type 1 diabetes (T1D) is a genetically conditioned autoimmune disease in which cytokines play an important role. Objectives. To check for the association of polymorphisms of cytokine genes with type 1 diabetes. Subjects. This work included 50 cases with T1D and 98 healthy individuals from the Nile Delta region of Egypt. Cases included 20 males and 30 females with a median age of 25 and range of 15-50 years. DNA was amplified using PCR with sequence-specific primers for detection of polymorphisms related to tumor necrosis factor (TNF)-alpha(- 308) (G/A), interleukin (IL)-10(- 1082) (G/A), IL-6(- 174) (G/C), and IL-1Ra (VNTR). Cases with T1D showed significant higher frequency of genotypes of TNF-alpha(- 308) AA (p < 0.001, odds ratio (OR) = 7.91), IL-6-17CC (p < 0.05, OR = 3.36) and IL-1Ra A1A1 (p < 0.05, OR = 3.68) with significant lower frequencies of TNF-alpha(- 308) GA, and IL-1Ra A1A2 genotypes (p < 0.001 and < 0.05, respectively). They also showed significant higher frequency of TNF-alpha(- 308) allele A (p < 0.05, OR = 2.0), IL-1Ra allele A1 (p < 0.05, OR = 2.98) with a significant lower frequency of TNF-alpha(- 308) G allele and IL-1Ra A2 allele (p < 0.05). No significant difference was detected among cases in relation to IL-10(- 1082) (G/A) genotypes or alleles nor in relation to age, sex, consanguinity or family history of the disease. Polymorphisms related to TNF-alpha and IL-1Ra genes may be considered genetic markers for T1D among Egyptians with a potential impact on family counseling and management.

A SUZAKU OBSERVATION OF Mkn 590 REVEALS A VANISHING SOFT EXCESS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivers, Elizabeth; Markowitz, Alex; Rothschild, Richard

2012-11-01

We have analyzed a long-look Suzaku observation of the Seyfert 1.2 Mkn 590. We aimed to measure the Compton reflection strength, Fe K complex properties, and soft excess emission as had been observed previously in this source. The Compton reflection strength was measured to be in the range 0.2-1.0 depending on the model used. A moderately strong Fe K{alpha} emission line was detected with an equivalent width of {approx}120 {+-} 25 eV and an Fe K{beta} line was identified with an equivalent width of {approx}30 {+-} 20 eV, although we could not rule out contribution from ionized Fe emission atmore » this energy. Surprisingly, we found no evidence for soft excess emission. Comparing our results with a 2004 observation from XMM-Newton we found that either the soft excess has decreased by a factor of 20-30 in 7 years or the photon index has steepened by 0.10 (with no soft excess present) while the continuum flux in the range 2-10 keV has varied only minimally (10%). This result could support recent claims that the soft excess is independent of the X-ray continuum.« less

Detector for imaging and dosimetry of laser-driven epithermal neutrons by alpha conversion

NASA Astrophysics Data System (ADS)

Mirfayzi, S. R.; Alejo, A.; Ahmed, H.; Wilson, L. A.; Ansell, S.; Armstrong, C.; Butler, N. M. H.; Clarke, R. J.; Higginson, A.; Notley, M.; Raspino, D.; Rusby, D. R.; Borghesi, M.; Rhodes, N. J.; McKenna, P.; Neely, D.; Brenner, C. M.; Kar, S.

2016-10-01

An epithermal neutron imager based on detecting alpha particles created via boron neutron capture mechanism is discussed. The diagnostic mainly consists of a mm thick Boron Nitride (BN) sheet (as an alpha converter) in contact with a non-borated cellulose nitride film (LR115 type-II) detector. While the BN absorbs the neutrons in the thermal and epithermal ranges, the fast neutrons register insignificantly on the detector due to their low neutron capture and recoil cross-sections. The use of solid-state nuclear track detectors (SSNTD), unlike image plates, micro-channel plates and scintillators, provide safeguard from the x-rays, gamma-rays and electrons. The diagnostic was tested on a proof-of-principle basis, in front of a laser driven source of moderated neutrons, which suggests the potential of using this diagnostic (BN+SSNTD) for dosimetry and imaging applications.

A comparison of cationic polymerization and esterification for end-point detection in the catalytic thermometric titration of organic bases.

PubMed

J Greenhow, E; Viñas, P

1984-08-01

A systematic comparison has been made of two indicator systems for the non-aqueous catalytic thermometric titration of strong and weak organic bases. The indicator reagents, alpha-methylstyrene and mixtures of acetic anhydride and hydroxy compounds, are shown to give results (for 14 representative bases) which do not diner significantly in coefficient of variation or titration error. Calibration graphs for all the samples, in the range 0.01-0.1 meq, are linear, with correlation coefficients of 0.995 or better. Aniline, benzylamine, n-butylamine, morpholine, pyrrole, l-dopa, alpha-methyl-l-dopa, dl-alpha-alanine, dl-leucine and l-cysteine cannot be determined when acetic anhydride is present in the sample solution, but some primary and second amines can. This is explained in terms of rates of acetylation of the amino groups.

Prestimulus neural oscillations inhibit visual perception via modulation of response gain.

PubMed

Chaumon, Maximilien; Busch, Niko A

2014-11-01

The ongoing state of the brain radically affects how it processes sensory information. How does this ongoing brain activity interact with the processing of external stimuli? Spontaneous oscillations in the alpha range are thought to inhibit sensory processing, but little is known about the psychophysical mechanisms of this inhibition. We recorded ongoing brain activity with EEG while human observers performed a visual detection task with stimuli of different contrast intensities. To move beyond qualitative description, we formally compared psychometric functions obtained under different levels of ongoing alpha power and evaluated the inhibitory effect of ongoing alpha oscillations in terms of contrast or response gain models. This procedure opens the way to understanding the actual functional mechanisms by which ongoing brain activity affects visual performance. We found that strong prestimulus occipital alpha oscillations-but not more anterior mu oscillations-reduce performance most strongly for stimuli of the highest intensities tested. This inhibitory effect is best explained by a divisive reduction of response gain. Ongoing occipital alpha oscillations thus reflect changes in the visual system's input/output transformation that are independent of the sensory input to the system. They selectively scale the system's response, rather than change its sensitivity to sensory information.

The phase of prestimulus alpha oscillations affects tactile perception.

PubMed

Ai, Lei; Ro, Tony

2014-03-01

Previous studies have shown that neural oscillations in the 8- to 12-Hz range influence sensory perception. In the current study, we examined whether both the power and phase of these mu/alpha oscillations predict successful conscious tactile perception. Near-threshold tactile stimuli were applied to the left hand while electroencephalographic (EEG) activity was recorded over the contralateral right somatosensory cortex. We found a significant inverted U-shaped relationship between prestimulus mu/alpha power and detection rate, suggesting that there is an intermediate level of alpha power that is optimal for tactile perception. We also found a significant difference in phase angle concentration at stimulus onset that predicted whether the upcoming tactile stimulus was perceived or missed. As has been shown in the visual system, these findings suggest that these mu/alpha oscillations measured over somatosensory areas exert a strong inhibitory control on tactile perception and that pulsed inhibition by these oscillations shapes the state of brain activity necessary for conscious perception. They further suggest that these common phasic processing mechanisms across different sensory modalities and brain regions may reflect a common underlying encoding principle in perceptual processing that leads to momentary windows of perceptual awareness.

Ultrastructural Aspects of the Prenatal Bovine Ovary Differentiation with a Special Focus on the Interstitial Cells.

PubMed

Kenngott, R A-M; Scholz, W; Sinowatz, F

2016-10-01

The aim of this investigation was to study the ultrastructural features during the development of fetal bovine ovaries (crown rump length ranging from 11.4 to 94.0 cm). An interesting observation was the occurrence of big elongated cells containing a variety of electron dense granules and light homogenous vacuoles/bodies. They were located between the stroma cells surrounding the germ cell cord ends, adjacent to the first formed primordial follicles, typically situated near blood vessels. ER alpha and ER beta receptor positive cells could be detected in the same regions by means of immunohistochemistry. Intercellular bridges linked the germ cells nests oogonia. Germ cell cords consisted of centrally located, large, pale oogonia, surrounded by elongated somatic cells with very long cytoplasm extensions. Primordial follicles with flat pale follicular cells could be observed on the inner end of the cords. Extrusions of the outer nuclear membrane could often been recognised in voluminous oocytes. © 2016 Blackwell Verlag GmbH.

Microwave enhanced electroanalysis of formulations: processes in micellar media at glassy carbon and at platinum electrodes.

PubMed

Ghanem, Mohamed A; Compton, Richard G; Coles, Barry A; Canals, Antonio; Marken, Frank

2005-10-01

The direct electroanalysis of complex formulations containing alpha-tocopherol (vitamin E) is possible in micellar solution and employing microwave-enhanced voltammetry. In the presence of microwave radiation substantial heating and current enhancement effects have been observed at 330 microm diameter glassy carbon electrodes placed into a micellar aqueous solution and both hydrophilic and highly hydrophobic redox systems are detected. For the water soluble Fe(CN)(6)(3-/4-) redox system in micellar aqueous solutions of 0.1 M NaCl and 0.1 M sodium dodecylsulfate (SDS) at low to intermediate microwave power, thermal effects and convection effects are observed. At higher microwave power, thermal cavitation is induced and dominates the mass transport at the electrode surface. For the micelle-soluble redox systems tert-butylferrocene and 2,5-di-tert-butyl-1,4-benzoquinone, strong and concentration dependent current responses are observed only in the presence of microwave radiation. For the oxidation of micelle-soluble alpha-tocopherol current responses at glassy carbon electrodes are affected by adsorption and desorption processes whereas at platinum electrodes, analytical limiting currents are obtained over a wide range of alpha-tocopherol concentrations. However, for the determination of alpha-tocopherol in a commercial formulation interference from proteins is observed at platinum electrodes and direct measurements are possible only over a limited concentration range and at glassy carbon electrodes.

Identification and quantification of metabolites common to 17alpha-methyltestosterone and mestanolone in horse urine.

PubMed

Yamada, Masayuki; Aramaki, Sugako; Okayasu, Toshimasa; Hosoe, Tomoo; Kurosawa, Masahiko; Kijima-Suda, Isao; Saito, Koichi; Nakazawa, Hiroyuki

2007-09-21

Anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, which were developed as oral formulations for therapeutic purposes, have been abused in the field of human sports. These anabolic steroids are also used to enhance racing performance in racehorses. In humans, structurally related 17alpha-methyltestosterone (MTS) and mestanolone (MSL), which are anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, have metabolites in common. The purpose of this study was to determine metabolites common to these two steroids in horses, which may serve as readily available screening targets for the doping test of these steroids in racehorses. Urine sample collected after administering MTS and MSL to horses was treated to obtain unconjugated steroid, glucuronide, and sulfate fractions. The fractions were subjected to gas chromatography/mass spectrometry (GC/MS), and 17alpha-methyl-5alpha-androstan-3beta,17beta-diol, 17alpha-hydroxymethyl-5alpha-androstan-3beta,17beta-diol, 17alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol, and 17alpha-methyl-5alpha-androstan-3beta,16alpha,17beta-triol were detected as the common metabolites by comparison with synthesized reference standards. The urinary concentrations of these metabolites after dosing were determined by GC/MS. 17Alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol was mainly detected in the sulfate fractions of urine samples after administration. This compound was consistently detected for the longest time in the urine samples after dosing with both steroids. The results suggest that 17alpha-methyl-5alpha-androstan-3beta,16beta,17beta-triol is a very useful screening target for the doping test of MTS and MSL in racehorses.

Immunoreactive transforming growth factor alpha is commonly present in colorectal neoplasia.

PubMed Central

Tanaka, S.; Imanishi, K.; Yoshihara, M.; Haruma, K.; Sumii, K.; Kajiyama, G.; Akamatsu, S.

1991-01-01

Surgical specimens from 19 patients with invasive colorectal cancers and 12 specimens of normal mucosa from the same patients were examined immunohistochemically for the production of the immunoreactive (IR-) transforming growth factor (TGF)-alpha and IR-epidermal growth factor (EGF) with an anti-TGF-alpha monoclonal antibody (MAb) OAL-MTG01 and anti-EGF MAb KEM-10. Immunoreactive TGF-alpha was detected in 16 (84.2%) of 19 colorectal cancers. In contrast, there was no IR-TGF-alpha in the gland cells of normal mucosa. Immunoreactive EGF was detected in 7 (36.8%) of 19 colorectal cancers and 1 (8.3%) of 12 cases of normal mucosa. The production of both IR-TGF-alpha and IR-EGF in colorectal cancer did not differ by histologic type and Dukes' stage. Immunoreactive TGF-alpha was detected at significantly higher incidence than IR-EGF in colorectal cancer. These results indicate that IR-TGF-alpha should prove valuable as a possible tumor marker in colorectal cancers, and it may be very useful in understanding the biology of colorectal cancer. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:1853928

Capillary electrochromatography immunoassay for alpha-fetoprotein based on poly(guanidinium ionic liquid) monolithic material.

PubMed

Liu, Cuicui; Deng, Qiliang; Fang, Guozhen; Dang, Meng; Wang, Shuo

2017-08-01

Alpha-fetoprotein (AFP) is widely used as a tumor marker for the serum diagnosis of primary hepatoma. Sensitive detection of AFP level plays an important role in the early diagnosis of disease and highly reliable prediction. In this study, a novel non-competitive immunoassay (IA) based on poly(guanidinium ionic liquid) monolithic material was developed for detecting ultra trace levels of AFP in capillary electrochromatography (CEC) mode. The AFP was mixed with an excess amount of fluorescently labeled antibody. After incubation, the immunocomplex was separated from the free labeled antibody and detected by CEC coupled with laser-induced fluorescence detector. Under the optimized conditions, the developed CEC-IA performed a low detection limit of 0.05 μg L -1  (S/N = 3) and a wide linearity ranging from 0.1 to 1000 μg L -1 for AFP, which can be largely attributed to the high separation and enrichment efficiency of poly(guanidinium ionic liquid) monolithic material for the targets. The application of this method was demonstrated by determining AFP in human serum. Copyright © 2017. Published by Elsevier Inc.

Tocopherol and tocotrienol levels of foods consumed in Hawaii.

PubMed

Franke, Adrian A; Murphy, Suzanne P; Lacey, Rochelle; Custer, Laurie J

2007-02-07

Because of the individual biological effects and the uncertain or missing information on levels of tocopherols (T) and tocotrienols (T3) in foods frequently consumed in Hawaii, 79 food items (50 in duplicate) were analyzed for alpha-, beta-, gamma-, and delta-tocopherol (alphaT, betaT, gammaT, and deltaT) and alpha-, beta-, gamma-, and delta-tocotrienol (alphaT3, betaT3, gammaT3, and deltaT3) in addition to alpha-tocopheryl acetate (alphaTac). Foods from local markets were stored according to usual household habits, freeze-dried, homogenized, and extracted three times with hexane containing butylated hydroxytoluene as a preservative and tocol as an internal standard. A normal-phase high-pressure liquid chromatography system was applied with fluorescence and photodiode array detection that resulted in baseline separation of all eight analytes and the internal standard tocol (To). The sum of all E vitamer concentrations, or total E vitamers (TEV), in all foods analyzed ranged an average from 0.6 to 828 mg/kg (T < or = 542 mg/kg and T3 < or = 432 mg/kg) and showed the following ranges: oils, 497-828 mg/kg (mainly alphaT and gammaT); margarines, 359-457 mg/kg (mainly gammaT); salad dressings, 20-291 mg/kg (mainly gammaT, except alphaT when soy oil was the main ingredient); cookies, 54-138 mg/kg (mainly gammaT); snacks, 101-220 mg/kg (mainly gammaT); nuts, 22-201 mg/kg (mainly alphaT); vegetables, 2-152 mg/kg (mainly alphaT); pasta, 24-90 mg/kg; cereals, 4-56 mg/kg (mainly betaT3 followed by alphaT); fish, 2-39 mg/kg (mainly alphaT); fried tofu, 64 mg/kg (mainly gammaT); breads, 20-22 mg/kg (mainly betaT3); fat-free mayonnaise, 5 mg/kg (mainly alphaT); poi (fermented taro root), 2 mg/kg (mostly alphaT); and fruits, 2 (papaya) to 13 mg/kg (canned pumpkin) with alphaT predominating. Cereals fortified with alphaTac ranked third and eighth among all foods assayed regarding alphaT and TEV levels, respectively. As compared to the few data available in the literature, our values agreed with some (corn flakes, mango fruit, fat-free mayonnaise, dry-roasted macadamia nuts, dry-roasted peanuts, mixed nuts, spaghetti/marinara pasta sauce, oils, and red bell pepper) but differed for many other items. Our results provide new information on the E vitamer content in foods, emphasize the vast differences of bioactivities of individual E vitamers, and confirm the need for analyses of foods consumed in specific study populations.

Postoperative alpha angle not associated with patient-centered midterm outcomes following hip arthroscopy for FAI.

PubMed

Briggs, Karen K; Soares, Eduardo; Bhatia, Sanjeev; Philippon, Marc J

2018-04-11

The most commonly used parameter for defining cam-type femoroacetabular impingement(FAI) has been the alpha angle. The purpose of this study was to determine if patient-reported outcomes 5 years following hip arthroscopy for FAI were associated with postoperative alpha angle. We hypothesized that patient-reported outcomes would not be influenced by postoperative alpha angle in patients with FAI. 230 patients had primary hip arthroscopy for FAI and chondrolabral dysfunction. The median age was 40 years (range 18-69). All patients had preoperative and 1 day postoperative alpha angles recorded. At minimum 5 years following arthroscopy, all patients completed an online questionnaire that included the modified Harris Hip score(MHHS), WOMAC, HOS ADL, HOS Sport, SF12 and patient satisfaction. This study was IRB approved. Patients were grouped into two, based on their postoperative alpha angle: <55° (n = 158) and ≥ 55° (n = 56). The median preoperative alpha angle was 72° (range 50°-105°) and the median postoperative alpha angle was 45° (range 30°-100°). The postoperative alpha angle did not correlate with any outcome measure. The median preoperative alpha angle in the < 55° group was 71° and in ≥ 55° group the median was 74° (p = 0.044). The median follow-up was 5.1 years (range 5-7). The median mHHS was 85 (range 47-100) in the < 55° and 85 (range 54-100) in the ≥ 55° group (n.s); WOMAC was 5 (range 0-73) in the < 55° and 4.5 (range 1-57) in the ≥ 55° group(n.s); HOS ADL was 95 (range 31-100) in the < 55° and 96 (range 50-100) in the ≥ 55° group (n.s); HOS Sport was 88 (range 0-100) in the < 55° and 88 (range 13-100) in the ≥ 55° group (n.s) Median patient satisfaction was 9 (range 1-10) in both groups. This study shows no statistically significant differences between the investigated patient-reported outcome scores at a 5 years postoperatively in relation to a correction of the alpha angle to 55°. While alpha angle has been shown to be an excellent preoperative diagnostic tool, the postoperative angle does not correlate with midterm outcomes or the development of osteoarthritis based on patient symptoms. The amount of osteoplasty should be based on dynamic examination at arthroscopy, and not by alpha angle. III Case-control, retrospective comparative study.

Modality-specific alpha modulations facilitate long-term memory encoding in the presence of distracters.

PubMed

Jiang, Haiteng; van Gerven, Marcel A J; Jensen, Ole

2015-03-01

It has been proposed that long-term memory encoding is not only dependent on engaging task-relevant regions but also on disengaging task-irrelevant regions. In particular, oscillatory alpha activity has been shown to be involved in shaping the functional architecture of the working brain because it reflects the functional disengagement of specific regions in attention and memory tasks. We here ask if such allocation of resources by alpha oscillations generalizes to long-term memory encoding in a cross-modal setting in which we acquired the ongoing brain activity using magnetoencephalography. Participants were asked to encode pictures while ignoring simultaneously presented words and vice versa. We quantified the brain activity during rehearsal reflecting subsequent memory in the different attention conditions. The key finding was that successful long-term memory encoding is reflected by alpha power decreases in the sensory region of the to-be-attended modality and increases in the sensory region of the to-be-ignored modality to suppress distraction during rehearsal period. Our results corroborate related findings from attention studies by demonstrating that alpha activity is also important for the allocation of resources during long-term memory encoding in the presence of distracters.

Evaluation of radioisotope tracer and activation analysis techniques for contamination monitoring in space environment simulation chambers

NASA Technical Reports Server (NTRS)

Smathers, J. B.; Kuykendall, W. E., Jr.; Wright, R. E., Jr.; Marshall, J. R.

1973-01-01

Radioisotope measurement techniques and neutron activation analysis are evaluated for use in identifying and locating contamination sources in space environment simulation chambers. The alpha range method allows the determination of total contaminant concentration in vapor state and condensate state. A Cf-252 neutron activation analysis system for detecting oils and greases tagged with stable elements is described. While neutron activation analysis of tagged contaminants offers specificity, an on-site system is extremely costly to implement and provides only marginal detection sensitivity under even the most favorable conditions.

Use of the Filovirus Animal Non-Clinical Group (FANG) Ebola virus immuno-assay requires fewer study participants to power a study than the Alpha Diagnostic International assay.

PubMed

Logue, James; Tuznik, Kaylie; Follmann, Dean; Grandits, Greg; Marchand, Jonathan; Reilly, Cavan; Sarro, Yeya Dit Sadio; Pettitt, James; Stavale, Eric J; Fallah, Mosoka; Olinger, Gene G; Bolay, Fatorma K; Hensley, Lisa E

2018-05-01

As part of the scientific community's development of medical countermeasures against Ebola virus disease, optimization of standardized assays for product evaluation is paramount. The recent outbreak heightened awareness to the scarcity of available assays and limited information on performance and reproducibility. To evaluate the immunogenicity of vaccines entering Phase I-III trials and to identify survivors, two enzyme-linked immunosorbent assays, the Filovirus Animal Non-Clinical Group assay and the Alpha Diagnostics International assay, were evaluated for detection of immunoglobulin G against Ebola virus glycoprotein. We found that the Filovirus Animal Nonclinical Group assay produced a wider range of relative antibody concentrations, higher assay precision, larger relative accuracy range, and lower regional background. Additionally, to sufficiently power a vaccine trial, use of the Filovirus Animal Nonclinical Group assay would require one third the number of participants than the Alpha Diagnostics International assay. This reduction in needed study participants will require less money, fewer man hours, and much less time to evaluate vaccine immunogenicity. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Long-range correlation and market segmentation in bond market

NASA Astrophysics Data System (ADS)

Wang, Zhongxing; Yan, Yan; Chen, Xiaosong

2017-09-01

This paper investigates the long-range auto-correlations and cross-correlations in bond market. Based on Detrended Moving Average (DMA) method, empirical results present a clear evidence of long-range persistence that exists in one year scale. The degree of long-range correlation related to maturities has an upward tendency with a peak in short term. These findings confirm the expectations of fractal market hypothesis (FMH). Furthermore, we have developed a method based on a complex network to study the long-range cross-correlation structure and applied it to our data, and found a clear pattern of market segmentation in the long run. We also detected the nature of long-range correlation in the sub-period 2007-2012 and 2011-2016. The result from our research shows that long-range auto-correlations are decreasing in the recent years while long-range cross-correlations are strengthening.

Long-range surface plasmon polariton detection with a graphene photodetector.

PubMed

Ee, Ho-Seok; No, You-Shin; Kim, Jinhyung; Park, Hong-Gyu; Seo, Min-Kyo

2018-06-15

We present an integration of a single Ag nanowire (NW) with a graphene photodetector and demonstrate an efficient and compact detection of long-range surface plasmon polaritons (SPPs). Atomically thin graphene provides an ideal platform to detect the evanescent electric field of SPPs extremely bound at the interface of the Ag NW and glass substrate. Scanning photocurrent microscopy directly visualizes a polarization-dependent excitation and detects the SPPs. The SPP detection responsivity is readily controlled up to ∼17  mA/W by the drain-source voltage. We believe that the graphene SPP detector will be a promising building block for highly integrated photonic and optoelectronic circuits.

Optimization of optical systems.

PubMed

Champagne, E B

1966-11-01

The power signal-to-noise ratios for coherent and noncoherent optical detection are presented, with the expression for noncoherent detection being examined in detail. It is found that for the long range optical system to compete with its microwave counterpart it is necessary to optimize the optical system. The optical system may be optimized by using coherent detection, or noncoherent detection if the signal is the dominate noise factor. A design procedure is presented which, in principle, always allows one to obtain signal shot-noise limited operation with noncoherent detection if pulsed operation is used. The technique should make reasonable extremely long range, high data rate systems of relatively simple design.

Addition products of alpha-tocopherol with lipid-derived free radicals.

PubMed

Yamauchi, Ryo

2007-01-01

The addition products of alpha-tocopherol with lipid-derived free radicals have been reviewed. Free radical scavenging reactions of alpha-tocopherol take place via the alpha-tocopheroxyl radical as an intermediate. If a suitable free radical is present, an addition product can be formed from the coupling of the free radical with the alpha-tocopheroxyl radical. The addition products of alpha-tocopherol with lipid-peroxyl radicals are 8a-(lipid-dioxy)-alpha-tocopherones, which are hydrolyzed to alpha-tocopherylquinone. On the other hand, the carbon-centered radicals of lipids prefer to react with the phenoxyl radical of alpha-tocopherol to form 6-O-lipid-alpha-tocopherol under anaerobic conditions. The addition products of alpha-tocopherol with peroxyl radicals (epoxylinoleoyl-peroxyl radicals) produced from cholesteryl ester and phosphatidylcholine were detected in the peroxidized human plasma using a high-sensitive HPLC procedure with postcolumn reduction and electrochemical detection. Thus, the formation of these addition products provides us with much information on the antioxidant function of vitamin E in biological systems.

Inflammatory C-reactive protein and cytokine levels in asymptomatic people with chronic spinal cord injury.

PubMed

Frost, Frederick; Roach, Mary Jo; Kushner, Irving; Schreiber, Peter

2005-02-01

To determine the relation between serologic markers of information and clinical characteristics of people with chronic spinal cord injury (SCI). Cross-sectional study. Academic medical center SCI outpatient clinic. Convenience sample of 37 men with chronic SCI and 10 healthy control subjects. Not applicable. Serum levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). The following results achieved statistical significance at P less than .05. Asymptomatic chronic SCI patients differed from referent controls with respect to serum CRP levels but not IL-6 or TNF-alpha. In SCI patients, higher levels of CRP correlated negatively with hemoglobin and albumin levels. A longer time since injury correlated with lower TNF-alpha values, whereas higher TNF-alpha levels correlated with higher serum albumin. Pressure ulcers and indwelling urinary catheters were associated with higher mean levels of CRP but not of the cytokines TNF-alpha and IL-6. Intermittent urinary catheterization was associated with lower levels of CRP when compared with other methods of bladder management. Asymptomatic people with long-term SCI, especially those with indwelling urinary catheters, showed serologic evidence of a systemic inflammatory state. There was no evidence of an elevation in proinflammatory cytokines. Detection of an ongoing systemic inflammatory response in apparently healthy people with indwelling urinary catheters and small skin ulcers further supports the aggressive pursuit of catheter-free voiding options and pressure ulcer healing.

Sub-lethal effects of the neurotoxic pyrethroid insecticide Fastac 50EC on the general motor and locomotor activities of the non-targeted beneficial carabid beetle Platynus assimilis (Coleoptera: Carabidae).

PubMed

Tooming, Ene; Merivee, Enno; Must, Anne; Sibul, Ivar; Williams, Ingrid

2014-06-01

Sub-lethal effects of pesticides on behavioural endpoints are poorly studied in carabids (Coleoptera: Carabidae) though changes in behaviour caused by chemical stress may affect populations of these non-targeted beneficial insects. General motor activity and locomotion are inherent in many behavioural patterns, and changes in these activities that result from xenobiotic influence mirror an integrated response of the insect to pesticides. Influence of pyrethroid insecticides over a wide range of sub-lethal doses on the motor activities of carabids still remains unclear. Video tracking of Platynus assimilis showed that brief exposure to alpha-cypermethrin at sub-lethal concentrations ranged from 0.01 to 100 mg L(-1) caused initial short-term (< 2 h) locomotor hyperactivity followed by a long-term (>24 h) locomotor hypo-activity. In addition, significant short- and long-term concentration and time-dependent changes occurred in general motor activity patterns and rates. Conspicuous changes in motor activity of Platynus assimilis beetles treated at alpha-cypermethrin concentrations up to 75,000-fold lower than maximum field recommended concentration (MFRC) suggest that many, basic fitness-related behaviours might be severely injured as well. These changes may negatively affect carabid populations in agro-ecosystems. Long-term hypo-activity could directly contribute to decreased trap captures of carabids frequently observed after insecticide application in the field. © 2013 Society of Chemical Industry.

Production stability of active polysaccharides of Dendrobium huoshanense using long-term cultures of protocorm-like bodies.

PubMed

Zha, Xue-Qiang; Luo, Jian-Ping

2008-01-01

In this study, the production stability of active polysaccharides in protocorm-like bodies (PLBs) induced from the seedling segments of Dendrobium huoshanense C. Z. Tang et S. J. Cheng was investigated during long-term subculture. Subcultures were conducted once every 30 days. With an average inoculum of 39 g/L fresh PLBs, the increase in biomass ranged from 95.7 g/L to 103.9 g/L in fresh weight and 3.2 g/L to 3.4 g/L in dry weight during eighteen continuous subcultures while polysaccharide content in PLBs was from 0.8 mg/g Fw (mg polysaccharide per gram PLBs in fresh weight) to 1.0 mg/g Fw. In addition, polysaccharides from all cultures showed a similar potential of stimulating interferon gamma (IFN-gamma) release in the supernatant of splenocytes and tumor necrosis factor alpha (TNF-alpha) release in the supernatant of peritoneal macrophages. To elucidate the genetic basis of polysaccharide production stability in long-term subculture of PLBs, the genetic fingerprints by RAPD were further analyzed using plantlets from PLB development. Results showed that there is no evidence of genetic variation both within the plantlets from the different subcultures of PLBs and between long-term subcultures and the donor plants.

ADRPM-VII applied to the long-range acoustic detection problem

NASA Technical Reports Server (NTRS)

Shalis, Edward; Koenig, Gerald

1990-01-01

An acoustic detection range prediction model (ADRPM-VII) has been written for IBM PC/AT machines running on the MS-DOS operating system. The software allows the user to predict detection distances of ground combat vehicles and their associated targets when they are involved in quasi-military settings. The program can also calculate individual attenuation losses due to spherical spreading, atmospheric absorption, ground reflection and atmospheric refraction due to temperature and wind gradients while varying parameters effecting the source-receiver problem. The purpose here is to examine the strengths and limitations of ADRPM-VII by modeling the losses due to atmospheric refraction and ground absorption, commonly known as excess attenuation, when applied to the long range detection problem for distances greater than 3 kilometers.

Suitability of ultra-high performance liquid chromatography for the determination of fat-soluble nutritional status (vitamins A, E, D, and individual carotenoids).

PubMed

Granado-Lorencio, F; Herrero-Barbudo, C; Blanco-Navarro, I; Pérez-Sacristán, B

2010-06-01

Our aim was to assess the suitability of ultra-high performance liquid chromatography (UHPLC) for the simultaneous determination of biomarkers of vitamins A (retinol, retinyl esters), E (alpha- and gamma-tocopherol), D (25-OH-vitamin D), and the major carotenoids in human serum to be used in clinical practice. UHPLC analysis was performed on HSS T3 column (2.1 x 100 mm; 1.8 microm) using gradient elution and UV-VIS detection. The system allows the simultaneous determination of retinol, retinyl palmitate, 25-OH-vitamin D, alpha- and gamma-tocopherol, lutein plus zeaxanthin, alpha-carotene, beta-carotene, alpha- and beta-cryptoxanthin and lycopene. The method showed a good linearity over the physiological range with an adequate accuracy in samples from quality control programs. Suitability of the method in clinical practice was tested by analyzing samples (n = 286) from patients. In conclusion, UHPLC constitutes a reliable approach for nutrient/biomarker profiling allowing the rapid, simultaneous and low-cost determination of vitamins A, E, and D (including vitamers and ester forms) and the major carotenoids in clinical practice.

A search for a new gauge boson A'

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jensen, Eric L.

2013-08-01

In the Standard Model, gauge bosons mediate the strong, weak, and electromagnetic forces. New forces could have escaped detection only if their mediators are either heavier than order(TeV) or weakly coupled to charged matter. New vector bosons with small coupling {alpha}' arise naturally from a small kinetic mixing with the photon and have received considerable attention as an explanation of various dark matter related anomalies. Such particles can be produced in electron-nucleus fixed-target scattering and then decay to e +e -+ pairs. New light vector bosons and their associated forces are a common feature of Standard Model extensions, but existingmore » constraints are remarkably sparse. The APEX experiment will search for a new vector boson A' with coupling α'/α fs > 6 × 10 -8 to electrons in the mass range 65MeV < mass A' < 550MeV. The experiment will study e +e - production off an electron beam incident on a high-Z target in Hall A at Jefferson Lab. The e - and e + will be detected in the High Resolution Spectrometers (HRSs). The invariant mass spectrum of the e +e - pairs will be scanned for a narrow resonance corresponding to the mass of the A'. A test run for the APEX experiment was held in the summer of 2010. Using the test run data, an A' search was performed in the mass range 175-250 MeV. The search found no evidence for an A' → e +e -reaction, and set an upper limit of {alpha}'/{alpha}{sub fs} ~ 10 -6.« less

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.; Li, Qian; Zhang, Yiwei

2014-11-01

Recently, we found that by terminating a long length of fiber of up to 1 km with an in-fiber cavity structure, the entire structure can detect vibrations over a frequency range from 5 Hz to 100 Hz. We want to determine whether the structure (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to the maintenance cost. Similarly, it will help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that will require the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Then, at even higher frequencies, the structure can be useful to detect acoustic vibrations (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large reenforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed long-gauge vibration sensor depends on packaging.

Uroepithelial cells are part of a mucosal cytokine network.

PubMed Central

Hedges, S; Agace, W; Svensson, M; Sjögren, A C; Ceska, M; Svanborg, C

1994-01-01

This study compared the cytokine production of uroepithelial cell lines in response to gram-negative bacteria and inflammatory cytokines. Human kidney (A498) and bladder (J82) epithelial cell lines were stimulated with either Escherichia coli Hu734, interleukin 1 alpha (IL-1 alpha), or tumor necrosis factor alpha (TNF-alpha). Supernatant samples were removed, and the RNA was extracted from cells at 0, 2, 6, and 24 h. The secreted cytokine levels were determined by bioassay or immunoassay; mRNA was examined by reverse transcription-PCR. The two cell lines secreted IL-6 and IL-8 constitutively. IL-6 and IL-8 mRNA were constitutively produced in both cell lines; IL-1 beta mRNA was detected in J82 cells. IL-1 alpha induced significantly higher levels of IL-6 secretion than did E. coli Hu734 or TNF-alpha. IL-1 alpha and TNF-alpha induced significantly higher levels of IL-8 secretion than did E. coli Hu734. Secreted IL-1 beta was not detected; IL-1 alpha and TNF-alpha were not detected above the levels used for stimulation. IL-1 alpha, IL-1 beta, IL-6, and IL-8 mRNAs were detected in both cell lines after exposure to the stimulants. TNF-alpha mRNA was occasionally detected in the J82 cell line after TNF-alpha stimulation. Cytokine (IL-6 and IL-8) and control (glyceraldehyde 3-phosphate dehydrogenase [G3PDH] and beta-actin) mRNA concentrations were quantitated with internal PCR standards. Cytokine mRNA levels relative to beta-actin mRNA levels were the highest in E. coli-stimulated cells. In comparison, the cytokine mRNA levels relative to G3PDH mRNA levels were the highest in IL-1 alpha-stimulated cells. beta-Actin mRNA levels decreased after bacterial stimulation but not after cytokine stimulation, while G3PDH mRNA levels increased in response to all of the stimulants tested. These results suggested that E. coli Hu734 lowered the beta-actin mRNA levels in uroepithelial cells, thus distorting the IL-6 and IL-8 mRNA levels relative to this control. In summary, E. coli IL-1 alpha and TNF-alpha were found to activate the de novo synthesis and secretion of IL-6 and IL-8 in uroepithelial cells. These results emphasize the role of epithelial cells in cytokine-mediated responses during the early stages of infection. Images PMID:8188354

Different patterns of 5{alpha}-reductase expression, cellular distribution, and testosterone metabolism in human follicular dermal papilla cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Shicheng; Yamauchi, Hitoshi

Androgens regulate hair growth, and 5{alpha}-reductase (5{alpha}R) plays a pivotal role in the action of androgens on target organs. To clarify the molecular mechanisms responsible for controlling hair growth, the present study presents evidence that the human follicular dermal papilla cells (DPCs) from either beard (bDPCs) or scalp hair (sDPCs) possess endogenous 5{alpha}R activity. Real-time RT-PCR revealed that the highest level of 5{alpha}R1 mRNA was found in bDPCs, followed by sDPCs, and a low but detectable level of 5{alpha}R1 mRNA was observed in fibroblasts. Minimally detectable levels of 5{alpha}R2 mRNA were found in all three cell types. A weak bandmore » at 26 kDa corresponding to the human 5{alpha}R1 protein was detected by Western blot in both DPCs, but not in fibroblasts. Immuonofluorescence analysis confirmed that 5{alpha}R1 was localized to the cytoplasm rather than in the nuclei in both DPCs Furthermore, a 5{alpha}R assay using [{sup 14}C]testosterone labeling in intact cells revealed that testosterone was transformed primarily into androstenedione, and in small amounts, into DHT. Our results demonstrate that the 5{alpha}R activities of either bDPCs or sDPCs are stronger than that of dermal fibroblasts, despite the fact that the major steroidogenic activity is attributed to 17{beta}-HSD rather than 5{alpha}R among the three cell types. The 5{alpha}R1 inhibitor MK386 exhibited a more potent inhibitory effect on 5{alpha}R activity than finasteride (5{alpha}R2 inhibitor) in bDPCs.« less

Induction of hypoxia-inducible factor-1alpha and activation of caspase-3 in hypoxia-reoxygenated bone marrow stroma is negatively regulated by the delayed production of substance P.

PubMed

Qian, J; Ramroop, K; McLeod, A; Bandari, P; Livingston, D H; Harrison, J S; Rameshwar, P

2001-10-15

The bone marrow (BM), which is the major site of immune cell development in the adult, responds to different stimuli such as inflammation and hemorrhagic shock. Substance P (SP) is the major peptide encoded by the immune/hemopoietic modulator gene, preprotachykinin-1 (PPT-I). Differential gene expression using a microarray showed that SP reduced hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA levels in BM stroma. Because long-term hypoxia induced the expression of PPT-I in BM mononuclear cells, we used timeline studies to determine whether PPT-I is central to the biologic responses of BM stroma subjected to 30-min hypoxia (pO(2) = 35 mm Hg) followed by reoxygenation. HIF-1alpha mRNA and protein levels were increased up to 12 h. At this time, beta-PPT-I mRNA was detected with the release of SP at 16 h. SP release correlated with down-regulation of HIF-1alpha to baseline. A direct role for SP in HIF-1alpha expression was demonstrated as follows: 1) transient knockout of beta-PPT-I showed an increase in HIF-1alpha expression up to 48 h of reoxygenation; and 2) HIF-1alpha expression remained baseline during reoxygenation when stroma was subjected to hypoxia in the presence of SP. Reoxygenation activated the PPT-I promoter with concomitant nuclear translocation of HIF-1alpha that can bind to the respective consensus sequences within the PPT-I promoter. SP reversed active caspase-3, an indicator of apoptosis and erythropoiesis, to homeostasis level after reoxygenation of hypoxic stroma. The results show that during reoxgenation the PPT-I gene acts as a negative regulator on the expression of HIF-1alpha and active caspase-3 in BM stroma subjected to reoxygenation.

Quantification of tamoxifen DNA adducts using on-line sample preparation and HPLC-electrospray ionization tandem mass spectrometry.

PubMed

Gamboa da Costa, Gonçalo; Marques, M Matilde; Beland, Frederick A; Freeman, James P; Churchwell, Mona I; Doerge, Daniel R

2003-03-01

The nonsteroidal antiestrogen tamoxifen is used as an adjuvant chemotherapeutic agent for the treatment of all stages of hormone-dependent breast cancer and more recently as a chemopreventive agent in women with elevated risk of developing the disease. While clearly beneficial for the treatment of breast cancer, tamoxifen has been reported to increase the risk of endometrial cancer in women. Furthermore, it has been shown to be hepatocarcinogenic in rats. Tamoxifen is clearly genotoxic in rat liver, as indicated by the formation of DNA adducts; the occurrence of tamoxifen DNA adducts in human endometrial tissue is more controversial. The detection and quantitation of tamoxifen DNA adducts have relied primarily upon (32)P-postlabeling, with other techniques, such as immunoassays and accelerator mass spectrometry, being used to a much lesser extent. To expand the range of available analytical methodologies for quantifying tamoxifen DNA adducts, we have developed an assay using on-line sample preparation, coupled with HPLC and electrospray ionization tandem mass spectrometry (ES-MS/MS). alpha-Acetoxytamoxifen was reacted with salmon testis DNA at ratios between 0.1 ng and 1 mg alpha-acetoxytamoxifen per mg DNA. After enzymatic hydrolysis to nucleosides, the most highly modified DNA samples were analyzed by HPLC-UV, which indicated the presence of two adduct peaks in approximately a 1:4 ratio. The major adduct was isolated, rigorously characterized as (E)-alpha-(deoxyguanosin-N(2)-yl)tamoxifen, and quantified on the basis of its molar extinction coefficient. A similar reaction was conducted with [N(CD(3))(2)]-alpha-acetoxytamoxifen to prepare a deuterated adduct that could serve as an internal standard for ES-MS/MS. The limit of detection for the HPLC-ES-MS/MS method was approximately 5 adducts/10(9) nucleotides, with an intra- and interassay precision of 3% relative standard deviation. The method was validated over the range of 8-1 520,000 adducts/10(8) nucleotides using 100 microg samples of DNA modified in vitro. Analysis of liver DNA from female Sprague-Dawley rats treated by gavage with seven daily doses of 20 mg tamoxifen/kg body weight gave a value of 496 +/- 16 adducts/10(8) nucleotides for (E)-alpha-(deoxyguanosin-N(2)-yl)tamoxifen and 626 +/- 18 adducts/10(8) nucleotides for (E)-alpha-(deoxyguanosin-N(2)-yl)-N-desmethyltamoxifen. These data indicate that the HPLC-ES-MS/MS methodology has sufficient sensitivity and precision to be useful in the analysis of tamoxifen DNA adducts formed in vivo in experimental models and may be able to detect tamoxifen DNA adduct formation in human tissue samples.

Automation of Classical QEEG Trending Methods for Early Detection of Delayed Cerebral Ischemia: More Work to Do.

PubMed

Wickering, Ellis; Gaspard, Nicolas; Zafar, Sahar; Moura, Valdery J; Biswal, Siddharth; Bechek, Sophia; OʼConnor, Kathryn; Rosenthal, Eric S; Westover, M Brandon

2016-06-01

The purpose of this study is to evaluate automated implementations of continuous EEG monitoring-based detection of delayed cerebral ischemia based on methods used in classical retrospective studies. We studied 95 patients with either Fisher 3 or Hunt Hess 4 to 5 aneurysmal subarachnoid hemorrhage who were admitted to the Neurosciences ICU and underwent continuous EEG monitoring. We implemented several variations of two classical algorithms for automated detection of delayed cerebral ischemia based on decreases in alpha-delta ratio and relative alpha variability. Of 95 patients, 43 (45%) developed delayed cerebral ischemia. Our automated implementation of the classical alpha-delta ratio-based trending method resulted in a sensitivity and specificity (Se,Sp) of (80,27)%, compared with the values of (100,76)% reported in the classic study using similar methods in a nonautomated fashion. Our automated implementation of the classical relative alpha variability-based trending method yielded (Se,Sp) values of (65,43)%, compared with (100,46)% reported in the classic study using nonautomated analysis. Our findings suggest that improved methods to detect decreases in alpha-delta ratio and relative alpha variability are needed before an automated EEG-based early delayed cerebral ischemia detection system is ready for clinical use.

Neutron detector using lithiated glass-scintillating particle composite

DOEpatents

Wallace, Steven [Knoxville, TN; Stephan, Andrew C [Knoxville, TX; Dai, Sheng [Knoxville, TN; Im, Hee-Jung [Knoxville, TN

2009-09-01

A neutron detector composed of a matrix of scintillating particles imbedded in a lithiated glass is disclosed. The neutron detector detects the neutrons by absorbing the neutron in the lithium-6 isotope which has been enriched from the natural isotopic ratio to a commercial ninety five percent. The utility of the detector is optimized by suitably selecting scintillating particle sizes in the range of the alpha and the triton. Nominal particle sizes are in the range of five to twenty five microns depending upon the specific scintillating particle selected.

Relating to monitoring ion sources

DOEpatents

Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore; Bounds, John Alan

2002-01-01

The apparatus and method provide techniques for monitoring the position on alpha contamination in or on items or locations. The technique is particularly applicable to pipes, conduits and other locations to which access is difficult. The technique uses indirect monitoring of alpha emissions by detecting ions generated by the alpha emissions. The medium containing the ions is moved in a controlled manner frog in proximity with the item or location to the detecting unit and the signals achieved over time are used to generate alpha source position information.

Biosensing using long-range surface plasmon waveguides

NASA Astrophysics Data System (ADS)

Krupin, Oleksiy; Khodami, Maryam; Fan, Hui; Wong, Wei Ru; Mahamd Adikan, Faisal Rafiq; Berini, Pierre

2017-05-01

Long-range surface plasmon waveguides, and their application to various transducer architectures for amplitude- or phase-sensitive biosensing, are discussed. Straight and Y-junction waveguides are used for direct intensity-based detection, whereas Bragg gratings and single-, dual- and triple-output Mach Zehnder interferometers are used for phasebased detection. In either case, multiple-output biosensors which provide means for referencing are very useful to eliminate common perturbations and drift. Application of the biosensors to disease detection in complex fluids is discussed. Application to biomolecular interaction analysis and kinetics extraction is also discussed.

Bayesian Analysis of Non-Gaussian Long-Range Dependent Processes

NASA Astrophysics Data System (ADS)

Graves, Timothy; Watkins, Nicholas; Franzke, Christian; Gramacy, Robert

2013-04-01

Recent studies [e.g. the Antarctic study of Franzke, J. Climate, 2010] have strongly suggested that surface temperatures exhibit long-range dependence (LRD). The presence of LRD would hamper the identification of deterministic trends and the quantification of their significance. It is well established that LRD processes exhibit stochastic trends over rather long periods of time. Thus, accurate methods for discriminating between physical processes that possess long memory and those that do not are an important adjunct to climate modeling. As we briefly review, the LRD idea originated at the same time as H-selfsimilarity, so it is often not realised that a model does not have to be H-self similar to show LRD [e.g. Watkins, GRL Frontiers, 2013]. We have used Markov Chain Monte Carlo algorithms to perform a Bayesian analysis of Auto-Regressive Fractionally-Integrated Moving-Average ARFIMA(p,d,q) processes, which are capable of modeling LRD. Our principal aim is to obtain inference about the long memory parameter, d, with secondary interest in the scale and location parameters. We have developed a reversible-jump method enabling us to integrate over different model forms for the short memory component. We initially assume Gaussianity, and have tested the method on both synthetic and physical time series. Many physical processes, for example the Faraday Antarctic time series, are significantly non-Gaussian. We have therefore extended this work by weakening the Gaussianity assumption, assuming an alpha-stable distribution for the innovations, and performing joint inference on d and alpha. Such a modified FARIMA(p,d,q) process is a flexible, initial model for non-Gaussian processes with long memory. We will present a study of the dependence of the posterior variance of the memory parameter d on the length of the time series considered. This will be compared with equivalent error diagnostics for other measures of d.

Long-range effect in nitrogen ion-implanted AISI 316L stainless steel

NASA Astrophysics Data System (ADS)

Budzynski, P.

2015-01-01

The effect of nitrogen ion implantation on AISI 316L stainless steel was investigated. The microstructure and composition of an N implanted layer were studied by RBS, GIXRD, SEM, and EDX measurements. Friction and wear tests were also performed. The discrepancy between the measured and calculated stopped ion maximum range does not exceed 0.03 μm. After nitrogen implantation with a fluence of 5 × 1017 ion/cm2, additional phases of expanded austenite were detected. At a 5-fold larger depth than the maximum ion range, improvement in the coefficient of friction and wear was detected. We have shown, for the first time, the long-range effect in tribological investigations. The long-range effect is caused by movement of not only defects along the depth of the sample, as assumed so far, but also nitrogen atoms.

Development of an alpha/beta/gamma detector for radiation monitoring

NASA Astrophysics Data System (ADS)

Yamamoto, Seiichi; Hatazawa, Jun

2011-11-01

For radiation monitoring at the site of nuclear power plant accidents such as Fukushima Daiichi, radiation detectors not only for gamma photons but also for alpha and beta particles are needed because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. We developed a radiation detector that can simultaneously monitor alpha and beta particles and gamma photons for radiation monitoring. The detector consists of three-layered scintillators optically coupled to each other and coupled to a photomultiplier tube. The first layer, which is made of a thin plastic scintillator (decay time: 2.4 ns), detects alpha particles. The second layer, which is made of a thin Gd2SiO5 (GSO) scintillator with 1.5 mol.% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol.% Ce (decay time: 70 ns) detects gamma photons. By using pulse shape discrimination, the count rates of these layers can be separated. With individual irradiation of alpha and beta particles and gamma photons, the count rate of the first layer represented the alpha particles, the second layer represented the beta particles, and the third layer represented the gamma photons. Even with simultaneous irradiation of the alpha and beta particles and the gamma photons, these three types of radiation can be individually monitored using correction for the gamma detection efficiency of the second and third layers. Our developed alpha, beta, and gamma detector is simple and will be useful for radiation monitoring, especially at nuclear power plant accident sites or other applications where the simultaneous measurements of alpha and beta particles and gamma photons are required.

Development of an alpha/beta/gamma detector for radiation monitoring.

PubMed

Yamamoto, Seiichi; Hatazawa, Jun

2011-11-01

For radiation monitoring at the site of nuclear power plant accidents such as Fukushima Daiichi, radiation detectors not only for gamma photons but also for alpha and beta particles are needed because some nuclear fission products emit beta particles and gamma photons and some nuclear fuels contain plutonium that emits alpha particles. We developed a radiation detector that can simultaneously monitor alpha and beta particles and gamma photons for radiation monitoring. The detector consists of three-layered scintillators optically coupled to each other and coupled to a photomultiplier tube. The first layer, which is made of a thin plastic scintillator (decay time: 2.4 ns), detects alpha particles. The second layer, which is made of a thin Gd(2)SiO(5) (GSO) scintillator with 1.5 mol.% Ce (decay time: 35 ns), detects beta particles. The third layer made of a thin GSO scintillator with 0.4 mol.% Ce (decay time: 70 ns) detects gamma photons. By using pulse shape discrimination, the count rates of these layers can be separated. With individual irradiation of alpha and beta particles and gamma photons, the count rate of the first layer represented the alpha particles, the second layer represented the beta particles, and the third layer represented the gamma photons. Even with simultaneous irradiation of the alpha and beta particles and the gamma photons, these three types of radiation can be individually monitored using correction for the gamma detection efficiency of the second and third layers. Our developed alpha, beta, and gamma detector is simple and will be useful for radiation monitoring, especially at nuclear power plant accident sites or other applications where the simultaneous measurements of alpha and beta particles and gamma photons are required. © 2011 American Institute of Physics

Project Longshot: An unmanned probe to Alpha Centauri

NASA Technical Reports Server (NTRS)

Beals, Keith A.; Beaulieu, Martin; Dembia, Frank J.; Kerstiens, Joseph; Kramer, Daniel L.; West, Jeffrey R.; Zito, James A.

1988-01-01

A preliminary design is presented for an unmanned probe to Alpha Centauri with a planned launch early in the 21st century. The probe would be assembled at the space station and take approx. 100 yrs to reach the nearest star. Several technologies must be developed in order for this mission to be possible. A pulsed fusion microexplosion drive with 1,000,000 secs of specific impulse is the primary enabling technology. A large, long life fission reactor with 300 kW power output is also required. Communications lasers would use a 0.532 micrometer wavelength since there is minimal power output by the stars in that frequency band. A laser with an input power of 250 kW would allow for a data rate of 1000 bits per second at maximum range. There are 3 types of information to be gathered by the probe: properties of the interstellar medium, characteristics of the three star Alpha Centauri system, and astrometry.

Long-range AIS message analysis based on the TianTuo-3 micro satellite

NASA Astrophysics Data System (ADS)

Li, Shiyou; Chen, Lihu; Chen, Xiaoqian; Zhao, Yong; Bai, Yuzhu

2017-07-01

The "Type-27 AIS message" is the long-range AIS broadcast message, which is primarily intended for the long-range detection of AIS typically by satellite. The TT3-AIS uses a four-frequency receiver scheme which includes two frequency channels conventionally applied by the AIS system and two new frequency channels allocated to the long-range AIS broadcast message. To the end of April 2016, the TT3-AIS has already received more than 11,400 packets of Type-27 AIS messages. In this paper, a detailed analysis of the Type-27 AIS messages is performed. Firstly, an eavesdropper diagram of the space-borne AIS received from the worldwide vessels is obtained. Secondly, the analysis to the trend of the number and the ratio of the new-type vessels is performed based on the Type-27 AIS message. The detection probability of the new-type vessels is also discussed. The result would be helpful on the usage of the long-range AIS message both for data application and for the improvement in designing the next space-based AIS receiver.

Search for long lived heaviest nuclei beyond the valley of stability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chowdhury, P. Roy; Samanta, C.; Physics Department, Virginia Commonwealth University, Richmond, Virginia 23284-2000

2008-04-15

The existence of long lived superheavy nuclei (SHN) is controlled mainly by spontaneous fission and {alpha}-decay processes. According to microscopic nuclear theory, spherical shell effects at Z=114, 120, 126 and N=184 provide the extra stability to such SHN to have long enough lifetime to be observed. To investigate whether the so-called 'stability island' could really exist around the above Z, N values, the {alpha}-decay half-lives along with the spontaneous fission and {beta}-decay half-lives of such nuclei are studied. The {alpha}-decay half-lives of SHN with Z=102-120 are calculated in a quantum tunneling model with DDM3Y effective nuclear interaction using Q{sub {alpha}}more » values from three different mass formulas prescribed by Koura-Uno-Tachibana-Yamada (KUTY), Myers-Swiatecki (MS), and Muntian-Hofmann-Patyk-Sobiczewski (MMM). Calculation of spontaneous fission (SF) half-lives for the same SHN are carried out using a phenomenological formula and compared with SF half-lives predicted by Smolanczuk et al. A possible source of discrepancy between the calculated {alpha}-decay half-lives of some nuclei and the experimental data of GSI, JINR-FLNR, RIKEN, is discussed. In the region of Z=106-108 with N{approx}160-164, the {beta}-stable SHN {sub 106}{sup 268}Sg{sub 162} is predicted to have highest {alpha}-decay half-life (T{sub {alpha}}{approx}3.2 h) using Q{sub {alpha}} value from MMM. Interestingly, it is much greater than the recently measured T{sub {alpha}} ({approx}22 s) of deformed doubly magic {sub 108}{sup 270}Hs{sub 162} nucleus. A few fission-survived long-lived SHN which are either {beta}-stable or having large {beta}-decay half-lives are predicted to exist near {sup 294}110{sub 184}, {sup 293}110{sub 183}, {sup 296}112{sub 184}, and {sup 298}114{sub 184}. These nuclei might decay predominantly through {alpha}-particle emission.« less

An alpha particle instrument with alpha, proton, and X-ray modes for planetary chemical analyses

NASA Technical Reports Server (NTRS)

Economou, T. E.; Turkevich, A. L.

1976-01-01

The interaction of alpha particles with matter is employed in a compact instrument that could provide rather complete in-situ chemical analyses of surfaces and thin atmospheres of extraterrestrial bodies. The instrument is a miniaturized and improved version of the Surveyor lunar instrument. The backscattering of alpha particles and (alpha, p) reactions provide analytical data on the light elements (carbon-iron). An X-ray mode that detects the photons produced by the alpha sources provides sensitivity and resolution for the chemical elements heavier than about silicon. The X-rays are detected by semiconductor detectors having a resolution between 150 and 250 eV at 5.9 keV. Such an instrument can identify and determine with good accuracy 99 percent of the atoms (except hydrogen) in rocks. For many trace elements, the detecting sensitivity is a few ppm. Auxiliary sources could be used to enhance the sensitivities for elements of special interest. The instrument could probably withstand the acceleration involved in semi-hard landings.

Hypertriglyceridemia during long-term interferon-alpha therapy: efficacy of diet and gemfibrosil treatment. A case report.

PubMed

Berruti, A; Gorzegno, G; Vitetta, G; Tampellini, M; Dogliotti, L

1992-10-31

Interferon-alpha might increase triglyceride serum levels through the enhancement of hepatic lipogenesis and/or inhibition of the peripheral lipoprotein lipase. Hypertriglyceridemia during interferon-alpha therapy has been only recently described, mostly in patients with previous abnormalities of lipid metabolism. The authors report here a case of a 65-year-old male bearing advanced colon carcinoma who developed hypertriglyceridemia during long-term interferon-alpha treatment in association with 5 fluorouracil administration. Hypertriglyceridemia was maintained within acceptable levels, without adjusting the treatment plan, by an appropriate diet and gemfibrosil administration.

Alpha2-adrenoceptor modulation of long-term potentiation elicited in vivo in rat occipital cortex.

PubMed

Mondaca, Mauricio; Hernández, Alejandro; Pérez, Hernán; Valladares, Luis; Sierralta, Walter; Fernández, Victor; Soto-Moyano, Rubén

2004-09-24

Pretreatment with the alpha(2)-adrenoceptor agonist clonidine (31.25, 62.5, or 125 microg/kg, i.p.) dose-dependently reduced long-term potentiation (LTP) elicited in vivo in the occipital cortex of anesthetized rats, whereas pretreatment with the alpha(2)-adrenoceptor antagonist yohimbine (0.133, 0.4, or 1.2 mg/kg, i.p.) increased neocortical LTP in a dose-dependent fashion. These effects could be related to the reported disruptive and facilitatory actions induced on memory formation by pretreatment with alpha(2)-adrenoceptor agonists and antagonists, respectively.

Near-complete teleportation of a superposed coherent state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheong, Yong Wook; Kim, Hyunjae; Lee, Hai-Woong

2004-09-01

The four Bell-type entangled coherent states, {alpha}>-{alpha}>{+-}-{alpha}>{alpha}> and {alpha}>{alpha}>{+-}-{alpha}>-{alpha}>, can be discriminated with a high probability using only linear optical means, as long as {alpha} is not too small. Based on this observation, we propose a simple scheme to almost completely teleport a superposed coherent state. The nonunitary transformation that is required to complete the teleportation can be achieved by embedding the receiver's field state in a larger Hilbert space consisting of the field and a single atom and performing a unitary transformation on this Hilbert space00.

Remote micro-encapsulation of curium-gold cermets

NASA Astrophysics Data System (ADS)

Coops, M. S.; Voegele, A. L.; Hayes, W. N.; Sisson, D. H.

1982-09-01

A technique has been developed to produce miniature, high-density capsules of curium-244 oxide contained in three concentric jackets of metallic gold or silver. The final capsules are right circular cylinders, 6.350 mm diameter by (3.18±0.05) mm long, with a minimum density of 11.0 g/cm 3. Each level of containment was soldered or brazed closed, with the outer surface free of detectable alpha contamination. Fabrication was performed in three separate small cells operated by standard master-slave manipulators. Production capsules have been stored for up to five years without indication of dimensional growth or leakage of radioactive contents. The dimensional stability of the capsules is attributed to the microporous structure of the plated-gold structure which permits helium gas resulting from alpha decay to diffuse through the capsule wall while retaining all radioactive materials.

Five-minute P Modes Detected in Doppler Shift Measurement on Alpha Centauri

NASA Technical Reports Server (NTRS)

Fossat, E.; Grec, G.; Gelly, B.

1984-01-01

A spectrophotometer using the principle of optical resonance spectroscopy, designed for the goal of identifying radial and weakly non radial eigenmodes in the five minute range in the case of stars, is discussed. The conclusion of the first test of this new instrument was that if the observation can be photon noise limited (i.e., in total absence of any instrumental source of noise), the five-minute solar oscillation could still be detected by removing the Sun far enough for its magnitude to become zero or one. Such a situation is very closely represented by the observation of Alpha Centauri A, because it is a G2 V star, very similar to the Sun, with a mass of 1.1 in solar unit. Six nights were granted to this program on a 3.6m telescope, from 22 to 28 May 1983. Two and half nights provided over 20 hours of data of photometric quality good enough for analysis.

GDNF and NGF family members and receptors in human fetal and adult spinal cord and dorsal root ganglia.

PubMed

Josephson, A; Widenfalk, J; Trifunovski, A; Widmer, H R; Olson, L; Spenger, C

2001-11-12

We describe the expression of mRNA encoding ligands and receptors of members of the GDNF family and members of the neurotrophin family in the adult human spinal cord and dorsal root ganglia (DRG). Fetal human spinal cord and ganglia were investigated for the presence of ligands and receptors of the neurotrophin family. Tissues were collected from human organ donors and after routine elective abortions. Messenger RNA was found encoding RET, GFR alpha-1, BDNF, trkB, and trkC in the adult human spinal cord and BDNF, NT-3, p75, trkB, and trkC in the fetal human spinal cord. The percentage of adult human DRG cells expressing p75, trkA, trkB, or trkC was 57, 46, 29, and 24%, respectively, and that of DRG cells expressing RET, GFR alpha-1, GFR alpha-2, or GFR alpha-3 was 79, 20, 51, and 32%, respectively. GFR alpha-2 was expressed selectively in small, GFR alpha-3 principally in small and GFR alpha-1 and RET in both large and small adult human DRG neurons. p75 and trkB were expressed by a wide range of DRG neurons while trkA was expressed in most small diameter and trkC primarily in large DRG neurons. Fetal DRG cells were positive for the same probes as adult DRG cells except for NT-3, which was only found in fetal DRG cells. Messenger RNA species only expressed at detectable levels in fetal but not adult spinal cord tissues included GDNF, GFR alpha-2, NT-3, and p75. Notably, GFR alpha-2, which is expressed in the adult rat spinal cord, was not found in the adult human spinal cord. Copyright 2001 Wiley-Liss, Inc.

The human interleukin-1 alpha gene is located on the long arm of chromosome 2 at band q13.

PubMed

Lafage, M; Maroc, N; Dubreuil, P; de Waal Malefijt, R; Pébusque, M J; Carcassonne, Y; Mannoni, P

1989-01-01

Interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) are two biochemically distinct, but distantly related, polypeptidic cytokines that play a key role in inflammation, immunologic reactions, and tissue repair. Recently, it has been shown that IL-1 alpha is identical to hematopoietin 1, which was described as a hematopoietic growth factor acting on early progenitor cells in synergy with other hematopoietic growth factors. In this report we discuss our use of in situ hybridization on human prometaphase cells with a human IL-1 alpha cDNA probe to localize the human IL-1 alpha gene on the proximal part of the long arm of chromosome 2 at band q13, in the same chromosomal region as the IL-1 beta gene.

Solar H-alpha features with hot onsets. III. Long fibrils in Lyman-alpha and with ALMA

NASA Astrophysics Data System (ADS)

Rutten, R. J.

2017-02-01

In H-alpha most of the solar surface is covered by dense canopies of long opaque fibrils, but predictions for quiet-Sun observations with ALMA have ignored this fact. Comparison with Ly-alpha suggests that the extraordinary opacity of H-alpha fibrils is caused by hot precursor events. Application of a recipe that assumes momentary Saha-Boltzmann extinction during their hot onset to millimeter wavelengths suggests that ALMA will observe H-alpha-like fibril canopies, not acoustic shocks underneath, and will yield data more interesting than if these canopies were transparent. An additional file is available at the end of the PDF file of this article.This study is offered as compliment to M.W.M. de Graauw. Our ways, objects, instruments and spectral domains parted after the 1970 eclipse but converge here.

Incidence of premature estrus in lactating dairy cows and conception rates to standing estrus or fixed-time inseminations after synchronization using GnRH and PGF(2alpha).

PubMed

DeJarnette, J M; Salverson, R R; Marshall, C E

2001-07-03

Fixed-time AI (TAI) after GnRH-PGF(2alpha)-GnRH treatment is a method to achieve pregnancies in dairy herds without estrous detection. However, cows that fail to respond to the initial GnRH may have compromised TAI conception rates due to asynchronous ovarian response. This study documented the percentage of GnRH-treated Holstein cows (n=345) in two herds that displayed estrus at an inopportune time for optimum TAI conception rate (< or =48h post-PGF(2alpha); premature estrus (PE)) and compared conception rates of two TAI protocols in cows that did not display PE. At biweekly herd health exams, cows diagnosed as not pregnant to a previous AI and cows >80 days postpartum with no AI were treated with 100 microg GnRH (day -7) and 25mg PGF(2alpha) (day 0). Cows detected in PE by twice-daily visual observation from day -7 to day 2 were bred by AI 8-12h later. Cows not detected in PE were randomly assigned by parity, body condition score, and postpartum interval to receive either: (1) 100microg GnRH at 48h after PGF(2alpha) and TAI 16 to 18h later (Ovsynch); or (2) TAI at 72h post-PGF(2alpha) and a concurrent 100 microg GnRH injection to those cows not detected in estrus between 48 and 72h post-PGF(2alpha) (modified Ovsynch (MOV)). All hormone injections were im. Twenty percent (68/345) of the cows were detected in estrus before 48 after PGF(2alpha), of which 5% (17/345) were detected in estrus before PGF(2alpha) (< or =day 0). Herd influenced the percentage of cows in the PE group (herd A versus herd B; 25% versus 14%; P<0.05). Conception rates were not affected by treatment (PE versus Ovsynch versus MOV; 32% (21/65) versus 30% (37/125) versus 32% (47/145); P>0.10). However, within MOV-treated cows, conception rates were greater (P<0.05) in cows detected in estrus (46% (23/50)) compared with cows not detected in estrus (25% (24/95)). In conclusion, 20% of GnRH-treated cows displayed PE and necessitates estrous detection during this period if maximal pregnancy rates are to be achieved. Although additional estrous detection is required compared to Ovsynch, reduced cow handling and hormone usage, efficient use of expensive semen through greater conception rates in cows detected in estrus, and comparable TAI conception rates, suggests the MOV protocol may be a cost effective alternative to Ovsynch in many dairy herd reproductive management programs.

Atmospheric organochlorine pollutants and air-sea exchange of hexachlorocyclohexane in the Bering and Chukchi Seas

USGS Publications Warehouse

Hinckley, D.A.; Bidleman, T.F.; Rice, C.P.

1991-01-01

Organochlorine pesticides have been found in Arctic fish, marine mammals, birds, and plankton for some time. The lack of local sources and remoteness of the region imply long-range transport and deposition of contaminants into the Arctic from sources to the south. While on the third Soviet-American Joint Ecological Expedition to the Bering and Chukchi Seas (August 1988), high-volume air samples were taken and analyzed for organochlorine pesticides. Hexachlorocyclohexane (HCH), hexachlorobenzene, polychlorinated camphenes, and chlordane (listed in order of abundance, highest to lowest) were quantified. The air-sea gas exchange of HCH was estimated at 18 stations during the cruise. Average alpha-HCH concentrations in concurrent atmosphere and surface water samples were 250 pg m-3 and 2.4 ng L-1, respectively, and average gamma-HCH concentrations were 68 pg m-3 in the atmosphere and 0.6 ng L-1 in surface water. Calculations based on experimentally derived Henry's law constants showed that the surface water was undersaturated with respect to the atmosphere at most stations (alpha-HCH, average 79% saturation; gamma-HCH, average 28% saturation). The flux for alpha-HCH ranged from -47 ng m-2 day-1 (sea to air) to 122 ng m-2 d-1 (air to sea) and averaged 25 ng m-2 d-1 air to sea. All fluxes of gamma-HCH were from air to sea, ranged from 17 to 54 ng m-2 d-1, and averaged 31 ng m-2 d-1.

Extended follow-up of anti-HBe-positive patients with chronic hepatitis B retreated with ribavirin and interferon-alpha.

PubMed

Carreño, V; Rico, M A; Pardo, M; Quiroga, J A

2001-11-01

In a pilot study of combination therapy with ribavirin and IFN alpha conducted in anti-HBe-positive individuals with chronic hepatitis B, 21% of patients achieved a sustained ALT normalization and clearance of hepatitis B virus (HBV) DNA as measured by PCR. The present work has assessed whether these sustained responses are lasting long-term. In addition, IFN gamma levels were tested serially in serum as a measure of the immune system activation during treatment. By extending the post-treatment follow-up period 2 years the occurrence of delayed HBV DNA relapses was observed. A low serum level of IFN gamma was detected during and after treatment. IFN gamma demonstrated a multiphasic time-course: the amount of IFN gamma increased in parallel with reductions in HBV DNA but also with ALT flare-ups. In conclusion, the extended follow-up study of anti-HBe-positive patients after combined treatment with ribavirin and IFN alpha has shown that sustained responses are lasting in 17% patients but also that a late onset HBV DNA relapse may occur.

Marine Mammal Acoustic Monitoring and Habitat Investigation, Southern California Channel Island Region

DTIC Science & Technology

2005-07-01

1998 . Long - range acoustic detection and localization of blue whale calls in the northeast Pacific Ocean. Journal of the Acoustical ...Peninsula. Deep-Sea Research II 51: 2327-2344. Stafford , K.M., C.G. Fox, and D.S. Clark. 1998 . Long - range acoustic detection and localization of blue ...speciation. Phil. Trans. R. Soc. Lond B 357:493-503. Stafford , K. M., Fox, C. G. and Clark, D.S. 1998

Rapid quantitative analysis of 8-iso-prostaglandin-F(2alpha) using liquid chromatography-tandem mass spectrometry and comparison with an enzyme immunoassay method.

PubMed

Dahl, Jeffrey H; van Breemen, Richard B

2010-09-15

A rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed for the measurement of urinary 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2alpha)), a biomarker of lipid peroxidation. Because urine contains numerous F(2) prostaglandin isomers, each with identical mass and similar mass spectrometric fragmentation patterns, chromatographic separation of 8-iso-PGF(2alpha) from its isomers is necessary for its quantitative analysis using MS/MS. We were able to achieve this separation using an isocratic LC method with a run time of less than 9min, which is at least threefold faster than previous methods, while maintaining sensitivity, accuracy, precision, and reliability. The limits of detection and quantitation were 53 and 178pg/ml urine, respectively. We compared our method with a commercially available affinity purification and enzyme immunoassay kit and found both assays to be in agreement. Despite the high sensitivity of the enzyme immunoassay method, it is more expensive and has a narrower dynamic range than LC-MS/MS. Our method was optimized for rapid measurement of 8-iso-PGF(2alpha) in urine, and it is ideally suited for clinical sample analysis. 2010 Elsevier Inc. All rights reserved.

Progress of pancreatitis disease biomarker alpha amylase enzyme by new nano optical sensor.

PubMed

Attia, M S; Al-Radadi, Najlaa S

2016-12-15

A new nano optical sensor binuclear Pd-(2-aminothiazole) (urea), Pd(atz,ur) complex was prepared and characterized for the assessment of the activity of alpha amylase enzyme in urine and serum samples for early diagnosis of Pancreatitis disease. The assessment of alpha amylase activity is carried out by the quenching of the luminescence intensity of the nano optical sensor binuclear Pd(atz,ur) complex at 457nm by the 2-chloro-4-nitrophenol (2-CNP) which produced from the reaction of the enzyme with 2-chloro-4-nitrophenyl-α-d-maltotrioside (CNPG3) substrate. The remarkable quenching of the luminescence intensity at 457nm of nano Pd(atz,ur) doped in sol-gel matrix by various concentrations of the 2-CNP was successfully used as an optical sensor for the assessment of α-amylase activity. The calibration plot was achieved over the concentration range 8.5×10(-6) to 1.9×10(-9)molL(-1) 2-CNP with a correlation coefficient of (0.999) and a detection limit of (7.4×10(-10)molL(-1)). The method was used satisfactorily for the assessment of the α-amylase activity over activity range (3-321U/L) in different urine and serum samples of pancreatitis patients. The assessment of the alpha amylase biomarker by the proposed method increases its sensitivity (96.88%) and specificity (94.41%) for early diagnosis of pancreatitis diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

Adverse Effects and Safety of 5-alpha Reductase Inhibitors (Finasteride, Dutasteride): A Systematic Review

PubMed Central

Hirshburg, Jason M.; Kelsey, Petra A.; Therrien, Chelsea A.; Gavino, A. Carlo; Reichenberg, Jason S.

2016-01-01

Finasteride and dutasteride, both 5-alpha reductase inhibitors, are considered first-line treatment for androgenetic hair loss in men and used increasingly in women. In each case, patients are expected to take the medications indefinitely despite the lack of research regarding long-term adverse effects. Concerns regarding the adverse effects of these medications has led the United States National Institutes of Health to add a link for post-finasteride syndrome to its Genetic and Rare Disease Information Center. Herein, the authors report the results of a literature search reviewing adverse events of 5-alpha reductase inhibitors as they relate to prostate cancer, psychological effects, sexual health, and use in women. Several large studies found no increase in incidence of prostate cancer, a possible increase of high-grade cancer when detected, and no change in survival rate with 5-alpha reductase inhibitor use. Currently, there is no direct link between 5-alpha reductase inhibitor use and depression; however, several small studies have led to depression being listed as a side effect on the medication packaging. Sexual effects including erectile dysfunction and decreased libido and ejaculate were reported in as many as 3.4 to 15.8 percent of men. To date, there are very few studies evaluating 5-alpha reductase inhibitor use in women. Risks include birth defects in male fetuses if used in pregnancy, decreased libido, headache, gastrointestinal discomfort, and isolated reports of changes in menstruation, acne, and dizziness. Overall, 5-alpha reductase inhibitors were well-tolerated in both men and women, but not without risk, highlighting the importance of patient education prior to treatment. PMID:27672412

Designing a valid and reliable Likert attitude scale on the generation of electricity from nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calhoun, L.D.

A 15-step flowchart model was applied to the construction of a 20-item long form and a 6-item short form of the scale. Both scales were field-tested on 829 respondents representing a diverse range of subjects: high school juniors and seniors, nuclear engineering students, pre-service teachers, and members of a citizens action group. Both scales are available for immediate use. The 20-item scale appears to be reliable, content valid, and construct valid. Content validity was examined through factor analysis and the use of two separate juries of nuclear experts. Construct validity was examined by application of the known-groups approach. Scale reliabilitymore » and homogeneity were evidenced by a 0.93 coefficient alpha, a range of positive interim correlations of 0.15 to 0.73, and a range of adjusted item-total correlations of 0.46 to 0.80. The 20-item scale also has evaluative quality; means ranged from 2.80 to 3.70. Content validity for the 6-item scale was examined by a jury of nuclear experts. An obtained coefficient alpha of 0.82, a range of interim correlations of 0.51 to 0.72 suggest the scale is reliable and homogeneous. The 6-item short form also appears to have evaluative quality; means ranged from 2.37 to 3.18.« less

Telangiectatic focal nodular hyperplasia of the liver in an infant with spontaneous regression: a case report.

PubMed

Hirakawa, Hitoshi; Ueno, Shigeru; Matuda, Hiromitu; Hinoki, Tomoya; Kato, Yuko

2009-04-20

A distinctive mass in the liver in a two-month-old girl with elevated serum alpha-fetoprotein (AFP) level was diagnosed as telangiectatic focal nodular hyperplasia (FNH) after biopsy. The tumor spontaneously regressed and finally became no longer detectable by any imaging study within normal range of AFP. The nature of this novel entity and its management are discussed based on literature review.

Fluorescence alteration of MPA capped CdSe quantum dots by spontaneous biomarker protein adsorption.

PubMed

Rowley, Amber; Parks, Tegan; Parks, Kaden; Medley, Kyle; Cordner, Alex; Yu, Ming

2018-05-23

Quantum dots (QDs) have significant potentials in biomedical applications of bioimaging and biosensing. Spontaneous adsorption of proteins on QDs surface is a common phenomenon, which occurred to serum proteins in biological samples, and has been observed to enhance QDs fluorescence. In this study, fluorescence alteration of 3-mercaptopropionic acid (MPA) capped CdSe quantum dots by four individual biomarker proteins was investigated. By monitoring the fluorescence emission of QDs, the biomarker protein adsorbed spontaneously on QDs surface was recognized and quantified. When alpha fetoprotein (AFP) or heat shock protein 90 alpha (HSP90α) were present, the QDs became brighter. The presence of cytochrome C (CytoC) or lysozyme (Lyz) made the QDs dimmer first, and then brighter. Within 5 min response time all four biomarker proteins were detected individually with the estimated detection limit in the range of 1-10 ng/mL and good linear dynamic ranges. The results suggested that the fluorescence of QDs was responsive to not only serum proteins but also biomarker proteins. The fluorescence response was able to correlate quantitatively with the amount of biomarker proteins in relatively low concentrations. These results provide more information to understand QDs and support their applications in biomedical fields. Copyright © 2018. Published by Elsevier Inc.

Nanobody medicated immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein.

PubMed

Chen, Jing; He, Qing-hua; Xu, Yang; Fu, Jin-heng; Li, Yan-ping; Tu, Zhui; Wang, Dan; Shu, Mei; Qiu, Yu-lou; Yang, Hong-wei; Liu, Yuan-yuan

2016-01-15

Immunoassay for cancer biomarkers plays an important role in cancer prevention and early diagnosis. To the development of immunoassay, the quality and stability of applied antibody is one of the key points to obtain reliability and high sensitivity for immunoassay. The main purpose of this study was to develop a novel immunoassay for ultrasensitive detection of cancer biomarker alpha-fetoprotein (AFP) based on nanobody against AFP. Two nanobodies which bind to AFP were selected from a phage display nanobody library by biopanning strategy. The prepared nanobodies are clonable, thermally stable and applied in both sandwich enzyme linked immunoassay (ELISA) and immuno-PCR assay for ultrasensitive detection of AFP. The limit detection of sandwich ELISA setup with optimized nanobodies was 0.48ng mL(-1), and the half of saturation concentration (SC50) value was 6.68±0.56ng mL(-1). These nanobodies were also used to develop an immuno-PCR assay for ultrasensitive detection of AFP, its limit detection values was 0.005ng mL(-1), and the linear range was 0.01-10,000ng mL(-1). These established immunoassays based on nanobodies were highly specific to AFP and with negligible cross reactivity with other tested caner biomarkers. Furthermore, this novel concept of nanobodies mediated immunoassay may provide potential applications in a general method for the ultrasensitive detection of various cancer biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

Twenty-four years of follow-up for a Hanford plutonium wound case.

PubMed

Carbaugh, Eugene H; Lynch, Timothy P; Antonio, Cheryl L; Medina-Del Valle, Fernando

2010-10-01

A 1985 plutonium puncture wound resulted in the initial deposition of 48 kBq of transuranic alpha activity, primarily 239+240Pu and 241Am, in a worker's right index finger. Surgical excisions in the week following reduced the long-term residual wound activity to 5.4 kBq, and 164 DTPA chelation therapy administrations over 17 mo resulted in urinary excretion of about 7 kBq. The case was published in 1988, but now 24 y of follow-up data are available. Annual bioassays have included in-vivo measurements of 241Am in the wound, skeleton, liver, lung, and axillary lymph nodes, and urinalyses for plutonium and 241Am. These measurements have shown relatively stable levels of 241Am at the wound site, with gradually increasing amounts of 241Am detected in the skeleton. Liver measurements have shown erratic detection of 241Am, and the lung measurements indicate Am but as interference from activity in the axillary lymph nodes and skeleton rather than activity in the lung. Urine excretion of Pu since termination of chelation therapy has typically ranged from 10 to 20 mBq d, with Am excretion about 10% of that for 239+240Pu. Annual routine medical exams have not identified any adverse health effects associated with the intake.

Twenty-four Years of Follow-Up for a Hanford Plutonium Wound Case

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Lynch, Timothy P.; Antonio, Cheryl L.

2010-10-01

A 1985 plutonium puncture wound resulted in the initial deposition of 48 kBq of transuranic alpha activity, primarily 239Pu and 241Am, in a worker’s right index finger. Surgical excisions in the week following reduced the long-term residual wound activity to 5.4 kBq, and 164 DTPA chelation therapy administrations over a 17-month period resulted in urinary excretion of about 7 kBq. The case was published in 1988, but now 20 additional years of follow-up data are available. Annual bioassay measurements have included wound counts, skeleton counts, liver counts, lung counts, axillary lymph node counts, and urinalyses for plutonium and 241Am. Thesemore » measurements have shown relatively stable levels of 241Am at the wound site, with gradually increasing amounts of 241Am detected in the skeleton. Liver counts has shown erratic detection of 241Am, and lung counts indicate 241Am as shine from the axillary lymph nodes and skeleton. Urine excretion of 239Pu since termination of chelation therapy has typically ranged from 10 to 20 mBq d-1, with 241Am excretion being about 10% of that for 239Pu. In addition, the worker has undergone annual routine medical exams, which have not identified any adverse health effects associated with the intake.« less

Noncompetitive Homogeneous Detection of Small Molecules Using Synthetic Nanopeptamer-Based Luminescent Oxygen Channeling.

PubMed

Lassabe, Gabriel; Kramer, Karl; Hammock, Bruce D; González-Sapienza, Gualberto; González-Techera, Andrés

2018-05-15

Our group has previously developed immunoassays for noncompetitive detection of small molecules based on the use of phage borne anti-immunocomplex peptides. Recently, we substituted the phage particles by biotinylated synthetic anti-immunocomplex peptides complexed with streptavidin and named these constructs nanopeptamers. In this work, we report the results of combining AlphaLisa, a commercial luminescent oxygen channeling bead system, with nanopeptamers for the development of a noncompetitive homogeneous assay for the detection of small molecules. The signal generation of AlphaLisa assays relies on acceptor-donor bead proximity induced by the presence of the analyte (a macromolecule) simultaneously bound by antibodies immobilized on the surface of these beads. In the developed assay, termed as nanoAlphaLisa, bead proximity is sustained by the presence of a small model molecule (atrazine, MW = 215) using an antiatrazine antibody captured on the acceptor bead and an atrazine nanopeptamer on the donor bead. Atrazine is one of the most used pesticides worldwide, and its monitoring in water has relevant human health implications. NanoAlphaLisa allowed the homogeneous detection of atrazine down to 0.3 ng/mL in undiluted water samples in 1 h, which is 10-fold below the accepted limit in drinking water. NanoAlphaLisa has the intrinsic advantages for automation and high-throughput, simple, and fast homogeneous detection of target analytes that AlphaLisa assay provides.

Upconversion nanoparticle as elemental tag for the determination of alpha-fetoprotein in human serum by inductively coupled plasma mass spectrometry.

PubMed

Liu, Zhengru; Yang, Bin; Chen, Beibei; He, Man; Hu, Bin

2016-12-19

Upconversion nanoparticles (UCNPs) have received increasing attention due to their unique optical properties. Recognizing that UCNPs are lanthanide-doped nanoparticles, we incorporated UCNPs into an immunoassay with inductively coupled plasma mass spectrometry (ICP-MS) detection for the determination of specific proteins, e.g., alpha-fetoprotein (AFP). The sensitivity of the assay was enhanced because of the ICP-MS detection of UCNPs that contained large numbers of lanthanide elemental tags. Conjugates of UCNPs and antibodies were prepared and the morphology of the conjugates was characterized by transmission electron microscopy. After a sandwich immunoreaction, the AFP was determined by the ICP-MS analysis of UCNPs. Under the optimized conditions, a limit of detection (3σ) of 0.31 ng mL -1 based on 89 Y signal and 0.22 ng mL -1 based on 174 Yb signal was obtained for AFP, with a dynamic range of 0.5-35 ng mL -1 and a relative standard deviation of 4.8% (c = 5 ng mL -1 , n = 9). The developed method was applied to the determination of AFP in human serum and the recovery for the spiked sample was in the range of 98.6-123%. The proposed method is simple, rapid, selective and sensitive, and has a good tolerance for the complex biological matrix, indicating great potential for the application of UCNP in biological research as an elemental tag.

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.

2014-06-01

Recently, we found that by terminating a long length of fiber of up to 2 km with an in-fiber cavity structure, the entire structure can detect vibrations over a frequency range from 5 Hz to 100 Hz. We want to determine whether the structure (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to the maintenance cost. Similarly, it will help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that will require the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Then, at even higher frequencies, the structure can be useful to detect acoustic vibrations (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large re-enforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed long-gauge vibration sensor depends on packaging.

Far-Infrared Hydrogen Lasers in the Peculiar Star MWC 349A

NASA Technical Reports Server (NTRS)

Strelnitski, Vladimir; Haas, Michael R.; Smith, Howard A.; Erickson, Edwin F.; Colgan, Sean W. J.; Hollenbach, David J.

1996-01-01

Far-infrared hydrogen recombination lines H15(alpha)(169.4 micrometers), H12(alpha)(88.8 micrometers), and H10(alpha)(52.5 micrometers) were detected in the peculiar luminous star MWC 349A from the Kuiper Airborne Observatory. Here it is shown that at least H15(alpha) is strongly amplified, with the probable amplification factor being greater than or about equal to 10(exp 3) and a brightness temperature that is greater than or about equal to 10(exp 7) kelvin. The other two lines also show signs of amplification, although to a lesser degree. Beyond H10(alpha) the amplification apparently vanishes. The newly detected amplified lines fall into the laser wavelength domain. These lasers, as well as the previously detected hydrogen masers may originate in the photoionized circumstellar disk of MWC 349A and constrain the disk's physics and structure.

A sensitive fluorescent sensor for quantification of alpha-fetoprotein based on immunosorbent assay and click chemistry.

PubMed

Xie, Qunfang; Weng, Xiuhua; Lu, Lijun; Lin, Zhenyu; Xu, Xiongwei; Fu, Caili

2016-03-15

A novel fluoresencent immunosensor for determination of cancer biomarkers such as alpha-fetoprotein (AFP) was designed by utilizing both the high specificity of antigen-antibody sandwich structure and the high sensitivity of the click chemistry based fluorescence detection. Instead of an enzyme or fluorophore, the CuO nanoparticles are labeled on the detection antibody, which was not susceptible to the change of the external environments. The CuO nanoparticles which were modified on the sandwich structure can be dissolved to produce Cu(2+) ions with the help of HCl and then the Cu(2+) ions were reduced by sodium ascorbate to produce Cu(+) ions which triggered the Cu(+) catalyzed alkyne-azide cycloaddition (CuAAC) reaction between the weak fluorescent compound (3-azido-7-hydroxycoumarin) and propargyl alcohol to form a strong fluorescent compound. A good linear relationship was observed between the fluorescence increase factor of the system and the concentration of AFP in the range of 0.025-5.0 ng/mL with a detection limit of 12 pg/mL (S/N=3). The proposed fluorescent sensor had been applied to detect AFP in the human serum samples and gave satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

A novel electrochemical immunosensor using β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase as labels for ultrasensitive detection of alpha-fetoprotein.

PubMed

Gao, Jian; Ma, Hongmin; Lv, Xiaohui; Yan, Tao; Li, Na; Cao, Wei; Wei, Qin

2015-09-17

In this work, a novel sandwich-type electrochemical immunosensor based on host-guest interaction was fabricated for the detection of alpha-fetoprotein (AFP). Due to the large specific surface area of multiwalled carbon nanotubes and the unique supramolecular recognition ability of β-cyclodextrins, ferrocenecarboxylic acid (Fc) was incorporated into this sensor platform by host-guest interaction to generate an electrochemical signal. And β-cyclodextrins functionalized silver supported adamantine-modified glucose oxidase (GOD-CD-Ag), was used as a label to improve the analytical performance of the immunosensor by the dual amplification strategy. The obtained GOD-CD-Ag conjugates could convert glucose into gluconic acid with the formation of hydrogen peroxide (H2O2). And then silver nanoparticles could in situ catalyze the reduction of the generated H2O2, dramatically improving the oxidation reaction of Fc. The developed immunosensor shows a wide linear calibration range from 0.001 to 5.0 ng/mL with a low detection limit (0.2 pg/mL) for the detection of AFP. The method, with ideal reproducibility and selectivity, has a wide application prospect in clinical research. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of an alpha-blocker (Nicergoline) and of a beta-blocker (Acebutolol) on the in vitro biosynthesis of vascular extracellular matrix.

PubMed

Moczar, M; Robert, A M; Jacotot, B; Robert, L

2001-05-01

The effect of an alpha-blocking agent and of a beta-blocking agent on the biosynthesis of extracellular matrix macromolecules of the arterial wall was investigated. Rabbit aorta explants were cultured up to 48 hours with radioactive proline, lysine or glucosamine. In presence of these drugs, at concentration shown to be effective for the inhibition of platelet-endothelial cell interactions (10(-7) M), the incorporation of 14C proline in total macromolecular proline was higher than in macromolecular hydroxyproline suggesting a relatively higher rate of biosynthesis of non-collagenous proteins as compared to collagens. The alpha-blocking increased the incorporation of 14C proline in collagenous and non-collagenous proteins after 18 hours of incubation. beta-blocking also increased the incorporation of proline in macromolecular proline and hydroxyproline as compared to control cultures. Both increased the incorporation of 3H glucosamine in newly synthesised glycosaminoglycans. beta-blocking increased mainly the neosynthesis of heparan sulphate, alpha-blocking that of hyaluronan. The incorporation of 14C-lysine in crosslinked, insoluble elastin was not modified. These experiments confirm that alpha and beta-blocking agents can influence not only the tonus of aortic smooth muscle cells but also the relative rates of biosynthesis of extracellular matrix macromolecules. This effect should be taken in consideration for the evaluation of the long range effect of alpha and beta-blocking drugs on the vascular wall.

Treatment of recalcitrant pemphigus vulgaris with the tumor necrosis factor alpha antagonist etanercept.

PubMed

Berookhim, Boback; Fischer, Harry D; Weinberg, Jeffrey M

2004-10-01

The treatment of pemphigus vulgaris (PV) is generally regarded as challenging. Patients with the disease require long-term systemic therapy, creating concern for the toxicities of these treatments. Corticosteroids, as drugs of first choice, often must be combined with steroid-sparing agents to prevent hazardous long-term side effects. We describe a 62-year-old woman with long-standing PV whose cutaneous disease responded to therapy with the tumor necrosis factor alpha (TNF-alpha) antagonist etanercept, which was started for treatment of her inflammatory seronegative arthritis. To our knowledge, this is the first report of its efficacy in the treatment of PV.

Application of inductively coupled plasma sector field mass spectrometry for low-level environmental americium-241 analysis.

PubMed

Varga, Zsolt

2007-03-28

An improved and novel sample preparation method for (241)Am analysis by inductively coupled plasma sector field mass spectrometry has been developed. The procedure involves a selective CaF(2) pre-concentration followed by an extraction chromatographic separation using TRU resin. The achieved absolute detection limit of 0.86 fg (0.11 mBq) is comparable to that of alpha spectrometry (0.1 mBq) and suitable for low-level environmental measurements. Analysis of different kinds of environmental standard reference materials (IAEA-384--Fangataufa lagoon sediment, IAEA-385--Irish Sea sediment and IAEA-308--Mixed seaweed from the Mediterranean Sea) and alpha spectrometry were used to validate the procedure. The chemical recovery of sample preparation ranged between 72 and 94%. The results obtained are in good agreement with reference values and those measured by alpha spectrometry. The proposed method offers a rapid and less labor-intensive possibility for environmental (241)Am analysis than the conventionally applied radioanalytical techniques.

24Mg(p, α) 21Na reaction study for spectroscopy of 21Na

DOE PAGES

Cha, S. M.; Chae, K. Y.; Kim, A.; ...

2015-11-03

The Mg-24(p, alpha)Na-21 reaction was measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to better constrain the spins and parities of the energy levels in Na-21 for the astrophysically important F-17(alpha, p)Ne-20 reaction rate calculation. 31-MeV proton beams from the 25-MV tandem accelerator and enriched Mg-24 solid targets were used. When recoiling He-4 particles from the Mg-24(p, alpha)Na-21 reaction we used a highly segmented silicon detector array to detect them; it measured the yields of He-4 particles over a range of angles simultaneously. A observed a new level at 6661 ± 5 keVmore » in the present work. The extracted angular distributions for the first four levels of Na-21 and the results from distorted wave Born approximation (DWBA) calculations were compared to verify and extract the angular momentum transfer.« less

Boron modulates extracellular matrix and TNF alpha synthesis in human fibroblasts.

PubMed

Benderdour, M; Hess, K; Dzondo-Gadet, M; Nabet, P; Belleville, F; Dousset, B

1998-05-29

Boric acid was not mitogenic for human fibroblasts and it did not change cell viability until 0.5% (w/v). Boric acid treatment affected the metabolism of human dermal fibroblasts in culture, decreasing the synthesis of extracellular matrix macromolecules such as proteoglycans, collagen, and total proteins. It also increased the release of these molecules into the culture medium. The principal proteins secreted into the medium after boric acid treatment had molecular masses of 90, 70, 58, 49, and 43 kDa and faint bands were detected by electrophoresis between 14 and 30 kDa. hsp 70 and TNF alpha were detected among the secreted proteins by immunoblotting, and the amount of TNF alpha released was quantified by radioimmunoassay. Total mRNA levels were higher after boric acid treatment and peaked after 6 h of treatment. TNF alpha mRNA was undetectable in unstimulated fibroblasts and two TNF alpha mRNA bands were detected after stimulation: immature mRNA (4.8 kb) and mature TNF alpha mRNA (1.9 kb). Thus, the effects of boric acid observed in wound repair in vivo may be due to TNF alpha synthesis and secretion.

QUASARS PROBING QUASARS. IV. JOINT CONSTRAINTS ON THE CIRCUMGALACTIC MEDIUM FROM ABSORPTION AND EMISSION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hennawi, Joseph F.; Prochaska, J. Xavier, E-mail: xavier@ucolick.org

2013-03-20

We have constructed a sample of 29 close projected quasar pairs where the background quasar spectrum reveals absorption from optically thick H I gas associated with the foreground quasar. These unique sightlines allow us to study the quasar circumgalactic medium (CGM) in absorption and emission simultaneously, because the background quasar pinpoints large concentrations of gas where Ly{alpha} emission, resulting from quasar-powered fluorescence, resonant Ly{alpha} scattering, and/or cooling radiation, is expected. A sensitive search (1{sigma} surface-brightness limits of SB{sub Ly{alpha}}{approx_equal}3 Multiplication-Sign 10{sup -18} erg s{sup -1} cm{sup -2} arcsec{sup -2}) for diffuse Ly{alpha} emission in the environments of the foreground (predominantlymore » radio-quiet) quasars is conducted using Gemini/GMOS and Keck/LRIS slit spectroscopy. We fail to detect large-scale {approx}100 kpc Ly{alpha} emission, either at the location of the optically thick absorbers or in the foreground quasar halos, in all cases except a single system. We interpret these non-detections as evidence that the gas detected in absorption is shadowed from the quasar UV radiation due to obscuration effects, which are frequently invoked in unified models of active galactic nuclei. Small-scale R {approx}< 50 kpc extended Ly{alpha} nebulosities are detected in 34% of our sample, which are likely the high-redshift analogs of the extended emission-line regions (EELRs) commonly observed around low-redshift (z < 0.5) quasars. This may be fluorescent recombination radiation from a population of very dense clouds with a low covering fraction illuminated by the quasar. We also detect a compact high rest-frame equivalent width (W{sub Ly{alpha}} > 50 A) Ly{alpha}-emitter with luminosity L{sub Ly{alpha}} = 2.1 {+-} 0.32 Multiplication-Sign 10{sup 41} erg s{sup -1} at small impact parameter R = 134 kpc from one foreground quasar, and argue that it is more likely to result from quasar-powered fluorescence, than simply be a star-forming galaxy clustered around the quasar. Our observations imply that much deeper integrations with upcoming integral-field spectrometers such as MUSE and KCWI will be able to routinely detect a diffuse Ly{alpha} glow around bright quasars on scales R {approx} 100 kpc and thus directly image the CGM.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panebianco, S.; Dore, D.; Giomataris, I.

Time Projection Chambers are widely used since many years for tracking and identification of charged particles in high energy physics. We present a new R and D project to investigate the feasibility of a Micromegas TPC for low energy heavy ions detection. Two physics cases are relevant for this project. The first is the study of the nuclear fission of actinides by measuring the fission fragments properties (mass, nuclear charge, kinetic energy) that will be performed at different installations and in particular at the NFS facility to be built in the framework of the SPIRAL2 project in GANIL. The secondmore » physics case is the study of heavy ion reactions, like ({alpha},{gamma}), ({alpha},p), ({alpha},n) and all the inverse reactions in the energy range between 1.5 and 3 AMeV using both stable and radioactive beams. These reactions have a key role in p process in nuclear astrophysics to explain the synthesis of heavy proton-rich nuclei. Within the project, a large effort is devoted to Monte-Carlo simulations and a detailed benchmark of different simulation codes on the energy loss and range in gas of heavy ions at low energy has been performed. A new approach for simulating the ion charge state evolution in GEANT4 is also presented. Finally, preliminary results of an experimental test campaign on prototype are discussed.« less

Extracting alpha band modulation during visual spatial attention without flickering stimuli using common spatial pattern.

PubMed

Fujisawa, Junya; Touyama, Hideaki; Hirose, Michitaka

2008-01-01

In this paper, alpha band modulation during visual spatial attention without visual stimuli was focused. Visual spatial attention has been expected to provide a new channel of non-invasive independent brain computer interface (BCI), but little work has been done on the new interfacing method. The flickering stimuli used in previous work cause a decline of independency and have difficulties in a practical use. Therefore we investigated whether visual spatial attention could be detected without such stimuli. Further, the common spatial patterns (CSP) were for the first time applied to the brain states during visual spatial attention. The performance evaluation was based on three brain states of left, right and center direction attention. The 30-channel scalp electroencephalographic (EEG) signals over occipital cortex were recorded for five subjects. Without CSP, the analyses made 66.44 (range 55.42 to 72.27) % of average classification performance in discriminating left and right attention classes. With CSP, the averaged classification accuracy was 75.39 (range 63.75 to 86.13) %. It is suggested that CSP is useful in the context of visual spatial attention, and the alpha band modulation during visual spatial attention without flickering stimuli has the possibility of a new channel for independent BCI as well as motor imagery.

Simultaneous separation and detection of actinides in acidic solutions using an extractive scintillating resin.

PubMed

Roane, J E; DeVol, T A

2002-11-01

An extractive scintillating resin was evaluated for the simultaneous separation and detection of actinides in acidic solutions. The transuranic extractive scintillating (TRU-ES) resin is composed of an inert macroporous polystyrene core impregnated with organic fluors (diphenyloxazole and 1,4-bis-(4-methyl-5-phenyl-2-oxazolyl)benzene) and an extractant (octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide in tributyl phosphate). The TRU-ES resin was packed into FEP Teflon tubing to produce a flow cell (0.2-mL free column volume), which is placed into a scintillation detection system to obtain pulse height spectra and time series data during loading and elution of actinides onto/from the resin. The alpha-particle absolute detection efficiencies ranged from 77% to 96.5%, depending on the alpha energy and quench. In addition to the on-line analyses, off-line analyses of the effluent can be conducted using conventional detection methods. The TRU-ES resin was applied to the quantification of a mixed radionuclide solution and two actual waste samples. The on-line characterization of the mixed radionuclide solution was within 10% of the reported activities whereas the agreement with the waste samples was not as good due to sorption onto the sample container walls and the oxidation state of plutonium. Agreement between the on-line and off-line analyses was within 35% of one another for both waste samples.

Asynchronous detection of kinesthetic attention during mobilization of lower limbs using EEG measurements.

PubMed

Melinscak, Filip; Montesano, Luis; Minguez, Javier

2016-02-01

Attention is known to modulate the plasticity of the motor cortex, and plasticity is crucial for recovery in motor rehabilitation. This study addresses the possibility of using an EEG-based brain-computer interface (BCI) to detect kinesthetic attention to movement. A novel experiment emulating physical rehabilitation was designed to study kinesthetic attention. The protocol involved continuous mobilization of lower limbs during which participants reported levels of attention to movement-from focused kinesthetic attention to mind wandering. For this protocol an asynchronous BCI detector of kinesthetic attention and deliberate mind wandering was designed. EEG analysis showed significant differences in theta, alpha, and beta bands, related to the attentional state. These changes were further pinpointed to bands relative to the frequency of the individual alpha peak. The accuracy of the designed BCI ranged between 60.8% and 68.4% (significantly above chance level), depending on the used analysis window length, i.e. acceptable detection delay. This study shows it is possible to use self-reporting to study attention-related changes in EEG during continuous mobilization. Such a protocol is used to develop an asynchronous BCI detector of kinesthetic attention, with potential applications to motor rehabilitation.

Asynchronous detection of kinesthetic attention during mobilization of lower limbs using EEG measurements

NASA Astrophysics Data System (ADS)

Melinscak, Filip; Montesano, Luis; Minguez, Javier

2016-02-01

Objective. Attention is known to modulate the plasticity of the motor cortex, and plasticity is crucial for recovery in motor rehabilitation. This study addresses the possibility of using an EEG-based brain-computer interface (BCI) to detect kinesthetic attention to movement. Approach. A novel experiment emulating physical rehabilitation was designed to study kinesthetic attention. The protocol involved continuous mobilization of lower limbs during which participants reported levels of attention to movement—from focused kinesthetic attention to mind wandering. For this protocol an asynchronous BCI detector of kinesthetic attention and deliberate mind wandering was designed. Main results. EEG analysis showed significant differences in theta, alpha, and beta bands, related to the attentional state. These changes were further pinpointed to bands relative to the frequency of the individual alpha peak. The accuracy of the designed BCI ranged between 60.8% and 68.4% (significantly above chance level), depending on the used analysis window length, i.e. acceptable detection delay. Significance. This study shows it is possible to use self-reporting to study attention-related changes in EEG during continuous mobilization. Such a protocol is used to develop an asynchronous BCI detector of kinesthetic attention, with potential applications to motor rehabilitation.

Cloning, sequence, and expression of a blood group B active recombinant alpha-D-galactosidase from pinto bean (Phaseolus vulgaris).

PubMed

Davis, M O; Hata, D J; Johnson, S A; Jones, D E; Harmata, M A; Evans, M L; Walker, J C; Smith, D S

1997-07-01

A cDNA encoding pinto bean alpha-D-galactosidase [E.C. 3.2.1.22] was obtained by amplification of cDNA using highly conserved sequences found in eucaryotic alpha-D-galactosidases. Subsequently a full length Phaseolus cDNA clone was obtained that is 1537 nt long and contains untranslated 5' and 3' sequences. The nucleotide sequence of the cDNA has a high degree of homology with other eucaryotic alpha-D-galactosidase genes. The recombinant alpha-D-galactosidase (rGal) was expressed in Escherichia coli and purified by ion exchange and affinity chromatography. Purified rGal was homogeneous by SDS-PAGE and had relative masses of 40.1 and 45.4 kDa under nonreducing and reducing conditions, respectively. The N-terminal sequence of the expressed protein contained the sequence GNGLGQTPPMG corresponding to that deduced from the cDNA sequence. The native molecular weight for rGal was determined to be 32.18 kDa by Sephacryl S-200 chromatography. The specific activity of the rGal was 349 mu moles of PNP-alpha-D-galactopyranoside hydrolyzed per mg of pure rGal per min. rGal was highly specific for alpha-D-galactosyl residues and degraded B oligosaccharide. No detectable hemagglutinin or protease activity was present in the preparations. Furthermore, rGal was active against the blood group B antigen on native human erythrocytes in cell suspension assays. The only detectable RBC phenotypic change was loss of the B and P1 epitopes. Recombinant Phaseolus vulgaris alpha-D-galactosidase may have useful biotechnical applications in the potential mass production of enzymatically converted, universally transfusable type O RBCs. alpha-D-galactosidase [E.C. 3.2.1.22] has been purified from a variety of procaryotic and eucaryotic species. Most alpha-D-galactosidases have similar low molecular weight substrate specificities, but activity against high molecular weight substrates is variable. Terminal alpha-D-galactoside residues are present in glycoproteins and glycolipids. Some alpha-D-galactosidases have activity against alpha-D-galactosyl residues on cell membrane glycoconjugates. Glycosidases with this property are useful for carbohydrate structural studies and biotechnical applications. Enzymes free of other glycosidase activities with activity near neutral pH are particularly useful for membrane modification studies on native cells. Complex sugar chains in glycolipids and glycoproteins have often been implicated in the growth and development of eucaryotes. In particular, complex sugar chains play an important role in the recognition of self in the immune system. Some alpha-D-galactosidases can modify certain carbohydrate membrane epitopes, thereby modulating the immune response. For example, the blood group B epitope expressed on erythrocytes contains a terminal alpha-D-galactosyl residue. Individuals lacking this antigen produce naturally occurring complement fixing antibodies to the B epitope. Hydrolysis of this terminal saccharide destroys the antigenic activity of the B determinant producing H antigen (blood type O) on erythrocytes. Only rare individuals produce clinically significant antibodies to the H antigen, and therefore, type O red blood cells are "universally" compatible and in great demand. Dhar purified alpha-D-galactosidase isozymes from Phaseolus vulgaris and characterized their activity. To our knowledge, our laboratory, in a brief report, is the first to describe the cloning of the gene and the use of recombinant enzyme for seroconverting blood type B to O cells. This paper describes the cloning, sequence, expression, purification, and characterization of recombinant alpha-D-galactosidase. Activity of the recombinant enzyme on the native human erythrocyte blood group B epitope is shown.

Efficient Bayesian inference for natural time series using ARFIMA processes

NASA Astrophysics Data System (ADS)

Graves, Timothy; Gramacy, Robert; Franzke, Christian; Watkins, Nicholas

2016-04-01

Many geophysical quantities, such as atmospheric temperature, water levels in rivers, and wind speeds, have shown evidence of long memory (LM). LM implies that these quantities experience non-trivial temporal memory, which potentially not only enhances their predictability, but also hampers the detection of externally forced trends. Thus, it is important to reliably identify whether or not a system exhibits LM. We present a modern and systematic approach to the inference of LM. We use the flexible autoregressive fractional integrated moving average (ARFIMA) model, which is widely used in time series analysis, and of increasing interest in climate science. Unlike most previous work on the inference of LM, which is frequentist in nature, we provide a systematic treatment of Bayesian inference. In particular, we provide a new approximate likelihood for efficient parameter inference, and show how nuisance parameters (e.g., short-memory effects) can be integrated over in order to focus on long-memory parameters and hypothesis testing more directly. We illustrate our new methodology on the Nile water level data and the central England temperature (CET) time series, with favorable comparison to the standard estimators [1]. In addition we show how the method can be used to perform joint inference of the stability exponent and the memory parameter when ARFIMA is extended to allow for alpha-stable innovations. Such models can be used to study systems where heavy tails and long range memory coexist. [1] Graves et al, Nonlin. Processes Geophys., 22, 679-700, 2015; doi:10.5194/npg-22-679-2015.

Silencing alpha-fetoprotein inhibits VEGF and MMP-2/9 production in human hepatocellular carcinoma cell.

PubMed

Meng, Wenbo; Li, Xun; Bai, Zhongtian; Li, Yan; Yuan, Jinqiu; Liu, Tao; Yan, Jun; Zhou, Wence; Zhu, Kexiang; Zhang, Hui; Li, Yumin

2014-01-01

Alpha-fetoprotein not only serves as a diagnostic marker for liver cancer, but also posses a variety of biological functions. However, the role of Alpha-fetoprotein on tumor angiogenesis and cell invasion remains incompletely understood. In this study, we aimed to evaluate if Alpha-fetoprotein can regulate the major angiogenic factors and matrix metalloproteinases in human liver cancer cells. Alpha-fetoprotein silencing was achieved by Stealth RNAi. Expression of Alpha-fetoprotein was examined by a full-automatic electrochemistry luminescence immunity analyzer. Expression of VEGF, VEGFR-2, MMP-9, and MMP-2 was examined by Western blot and immunocytochemistry. Apoptosis was detected by TUNEL assay. Angiogenesis was detected by in vitro angiogenesis assay kit. Silencing of Alpha-fetoprotein led to an increased apoptosis, which was associated with a decreased expression of vascular endothelial growth factor, vascular endothelial growth factor receptor 2, matrix metalloproteinases-2/9. These results suggest that Alpha-fetoprotein may play a regulatory role on angiogenesis and cell invasion during liver cancer development.

Determination of branched chain amino acids, methionine, phenylalanine, tyrosine and alpha-keto acids in plasma and dried blood samples using HPLC with fluorescence detection.

PubMed

Kand'ár, Roman; Záková, Pavla; Jirosová, Jana; Sladká, Michaela

2009-01-01

The determination of branched chain amino acids [BCAA; valine (Val), leucine (Leu), isoleucine (Ile)], alpha-keto acids derived from BCAA [BCKA; alpha-ketoisovaleric acid (KIV), alpha-ketoisocaproic acid (KIC), alpha-ketomethylvaleric acid (KMV)], methionine (Met), phenylalanine (Phe) and tyrosine (Tyr) is currently the most reliable approach for the diagnosis of maple syrup urine disease (MSUD), hypermethioninemia, phenylketonuria (PKU) and tyrosinemia. The aim of this study was to develop rapid and simple HPLC methods for measurement of BCAA, Met, Phe, Tyr and BCKA in plasma and dried blood samples. Samples of peripheral venous blood with EDTA as anticoagulant were obtained from a group of healthy blood donors (n=70, 35 females, 27-41 years of age and 35 males, 28-43 years of age). Blood-spot samples from a group of newborns (n=80, 40 girls and 40 boys 3-5 days of age) were collected onto #903 Specimen Collection Paper and allowed to dry for at least 24 h before analysis. Prior to separation, the amino acids (AA) were derivatized with o-phthaldialdehyde (OPA) and BCKA with o-phenylenediamine (OPD). Reverse phase column chromatography (LiChroCart 125-4 Purospher RP-18e, 5 microm) was used for separation and fluorescence detection used to monitoring of effluent. For AA analysis, 25 mmol/L sodium hydrogenphosphate-methanol (90:10, v/v), pH 6.5+/-0.1 was used as mobile phase A and 100% methanol was used as mobile phase B. Measurement of BCKA used a mixture of methanol and deionized water (55:45, v/v) as mobile phase A and mobile phase B consisted of 100% methanol. Analytical performance of these methods was satisfactory for the determination of all AA and BCKA. The intra-assay and inter-assay coefficients of variation were below 10% and recovery ranged from 90%-110%. We have developed simple, rapid and selective HPLC methods with fluorescence detection for the determination of BCAA, Met, Phe, Tyr and BCKA in plasma and dried blood samples.

Fabry-Perot Observations of [OI]6300, Hα, H-Beta, and NH2 Emissions from Comet Hyakutake C/1996B2

NASA Astrophysics Data System (ADS)

Scherb, F.; Roesler, F. L.; Tufte, S.; Haffner, M.

1996-05-01

During the period 16-23 March 1996, observations of Comet Hyakutake were carried out with the new WHAM facility at the University of Wisconsin Pine Bluff Observatory, near Madison. WHAM is a second-generation double-Fabry-Perot/CCD spectrometer that is more than ten times as efficient as our previous large-aperture Fabry-Perot instruments. Specifications of WHAM in the spectral mode are: a 1-degree field of view (FOV) on the sky, 10 km/sec velocity resolution, 200 km/sec range, and 20 sigma detection of a 1-Rayleigh H-alpha emission line in about 30 seconds. WHAM can also operate in a mode in which an image of an emission source over a 1-degree FOV can be obtained at a spectral resolution of about 10 km/sec. Spectra of cometary [OI]6300, H-alpha, H-beta, and NH2 emissions were obtained with the FOV centered on the comet head and also located 3/4 degree sunward of the comet head, repectively. This was the first time that cometary H-beta emission has been detected. Images of cometary [OI]6300 and NH2 emissions were obtained with the FOV centered on the comet head. The interpretation of these observations using coma gas dynamic and photochemical models yields values of the H2O production rate from both the [OI]6300 and H-alpha data. Comparison of the cometary H-alpha and H-beta intensities provides unique ground-based information on the EUV solar Lyman-beta and Lyman-gamma emission lines. These results will be presented.

The Ly(alpha) Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage

NASA Technical Reports Server (NTRS)

Martin, Crystal L.; Dijkstra, Mark; Henry, Alaina L.; Soto, Kurt T.; Danforth, Charles W.; Wong, Joseph

2015-01-01

We present new Hubble Space Telescope Cosmic Origins Spectrograph far-ultraviolet (far-UV) spectroscopy and Keck Echellete optical spectroscopy of 11 ultraluminous infrared galaxies (ULIRGs), a rare population of local galaxies experiencing massive gas inflows, extreme starbursts, and prominent outflows. We detect Ly(alpha) emission from eight ULIRGs and the companion to IRAS09583+4714. In contrast to the P Cygni profiles often seen in galaxy spectra, the Ly(alpha) profiles exhibit prominent, blueshifted emission out to Doppler shifts exceeding -1000 km/s in three H II-dominated and two AGN-dominated ULIRGs. To better understand the role of resonance scattering in shaping the Ly(alpha) line profiles, we directly compare them to non-resonant emission lines in optical spectra. We find that the line wings are already present in the intrinsic nebular spectra, and scattering merely enhances the wings relative to the line core. The Ly(alpha) attenuation (as measured in the COS aperture) ranges from that of the far-UV continuum to over 100 times more. A simple radiative transfer model suggests the Ly(alpha) photons escape through cavities which have low column densities of neutral hydrogen and become optically thin to the Lyman continuum in the most advanced mergers. We show that the properties of the highly blueshifted line wings on the Ly(alpha) and optical emission-line profiles are consistent with emission from clumps of gas condensing out of a fast, hot wind. The luminosity of the Ly(alpha) emission increases nonlinearly with the ULIRG bolometric luminosity and represents about 0.1-1% of the radiative cooling from the hot winds in the H II-dominated ULIRGs.

Mutual information identifies spurious Hurst phenomena in resting state EEG and fMRI data

NASA Astrophysics Data System (ADS)

von Wegner, Frederic; Laufs, Helmut; Tagliazucchi, Enzo

2018-02-01

Long-range memory in time series is often quantified by the Hurst exponent H , a measure of the signal's variance across several time scales. We analyze neurophysiological time series from electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) resting state experiments with two standard Hurst exponent estimators and with the time-lagged mutual information function applied to discretized versions of the signals. A confidence interval for the mutual information function is obtained from surrogate Markov processes with equilibrium distribution and transition matrix identical to the underlying signal. For EEG signals, we construct an additional mutual information confidence interval from a short-range correlated, tenth-order autoregressive model. We reproduce the previously described Hurst phenomenon (H >0.5 ) in the analytical amplitude of alpha frequency band oscillations, in EEG microstate sequences, and in fMRI signals, but we show that the Hurst phenomenon occurs without long-range memory in the information-theoretical sense. We find that the mutual information function of neurophysiological data behaves differently from fractional Gaussian noise (fGn), for which the Hurst phenomenon is a sufficient condition to prove long-range memory. Two other well-characterized, short-range correlated stochastic processes (Ornstein-Uhlenbeck, Cox-Ingersoll-Ross) also yield H >0.5 , whereas their mutual information functions lie within the Markovian confidence intervals, similar to neural signals. In these processes, which do not have long-range memory by construction, a spurious Hurst phenomenon occurs due to slow relaxation times and heteroscedasticity (time-varying conditional variance). In summary, we find that mutual information correctly distinguishes long-range from short-range dependence in the theoretical and experimental cases discussed. Our results also suggest that the stationary fGn process is not sufficient to describe neural data, which seem to belong to a more general class of stochastic processes, in which multiscale variance effects produce Hurst phenomena without long-range dependence. In our experimental data, the Hurst phenomenon and long-range memory appear as different system properties that should be estimated and interpreted independently.

Relapse surveillance in AFP-positive hepatoblastoma: re-evaluating the role of imaging.

PubMed

Rojas, Yesenia; Guillerman, R Paul; Zhang, Wei; Vasudevan, Sanjeev A; Nuchtern, Jed G; Thompson, Patrick A

2014-10-01

Children with hepatoblastoma routinely undergo repetitive surveillance imaging, with CT scans for several years after therapy, increasing the risk of radiation-induced cancer. The purpose of this study was to determine the utility of surveillance CT scans compared to serum alpha-fetoprotein (AFP) levels for the detection of hepatoblastoma relapse. This was a retrospective study of all children diagnosed with AFP-positive hepatoblastoma from 2001 to 2011 at a single institution. Twenty-six children with hepatoblastoma were identified, with a mean age at diagnosis of 2 years 4 months (range 3 months to 11 years). Mean AFP level at diagnosis was 132,732 ng/ml (range 172.8-572,613 ng/ml). Five of the 26 children had hepatoblastoma relapse. A total of 105 imaging exams were performed following completion of therapy; 88 (84%) CT, 8 (8%) MRI, 5 (5%) US and 4 (4%) FDG PET/CT exams. A total of 288 alpha-fetoprotein levels were drawn, with a mean of 11 per child. The AFP level was elevated in all recurrences and no relapses were detected by imaging before AFP elevation. Two false-positive AFP levels and 15 false-positive imaging exams were detected. AFP elevation was found to be significantly more specific than PET/CT and CT imaging at detecting relapse. We recommend using serial serum AFP levels as the preferred method of surveillance in children with AFP-positive hepatoblastoma, reserving imaging for the early postoperative period, for children at high risk of relapse, and for determination of the anatomical site of clinically suspected recurrence. Given the small size of this preliminary study, validation in a larger patient population is warranted.

Long-term intravenous treatment of Pompe disease with recombinant human alpha-glucosidase from milk.

PubMed

Van den Hout, Johanna M P; Kamphoven, Joep H J; Winkel, Léon P F; Arts, Willem F M; De Klerk, Johannes B C; Loonen, M Christa B; Vulto, Arnold G; Cromme-Dijkhuis, Adri; Weisglas-Kuperus, Nynke; Hop, Wim; Van Hirtum, Hans; Van Diggelen, Otto P; Boer, Marijke; Kroos, Marian A; Van Doorn, Pieter A; Van der Voort, Edwin; Sibbles, Barbara; Van Corven, Emiel J J M; Brakenhoff, Just P J; Van Hove, Johan; Smeitink, Jan A M; de Jong, Gerard; Reuser, Arnold J J; Van der Ploeg, Ans T

2004-05-01

Recent reports warn that the worldwide cell culture capacity is insufficient to fulfill the increasing demand for human protein drugs. Production in milk of transgenic animals is an attractive alternative. Kilogram quantities of product per year can be obtained at relatively low costs, even in small animals such as rabbits. We tested the long-term safety and efficacy of recombinant human -glucosidase (rhAGLU) from rabbit milk for the treatment of the lysosomal storage disorder Pompe disease. The disease occurs with an estimated frequency of 1 in 40,000 and is designated as orphan disease. The classic infantile form leads to death at a median age of 6 to 8 months and is diagnosed by absence of alpha-glucosidase activity and presence of fully deleterious mutations in the alpha-glucosidase gene. Cardiac hypertrophy is characteristically present. Loss of muscle strength prevents infants from achieving developmental milestones such as sitting, standing, and walking. Milder forms of the disease are associated with less severe mutations and partial deficiency of alpha-glucosidase. In the beginning of 1999, 4 critically ill patients with infantile Pompe disease (2.5-8 months of age) were enrolled in a single-center open-label study and treated intravenously with rhAGLU in a dose of 15 to 40 mg/kg/week. Genotypes of patients were consistent with the most severe form of Pompe disease. Additional molecular analysis failed to detect processed forms of alpha-glucosidase (95, 76, and 70 kDa) in 3 of the 4 patients and revealed only a trace amount of the 95-kDa biosynthetic intermediate form in the fourth (patient 1). With the more sensitive detection method, 35S-methionine incorporation, we could detect low-level synthesis of -glucosidase in 3 of the 4 patients (patients 1, 2, and 4) with some posttranslation modification from 110 kDa to 95 kDa in 1 of them (patient 1). One patient (patient 3) remained totally deficient with both detection methods (negative for cross-reactive immunologic material [CRIM negative]). The alpha-glucosidase activity in skeletal muscle and fibroblasts of all 4 patients was below the lower limit of detection (<2% of normal). The rhAGLU was tolerated well by the patients during >3 years of treatment. Anti-rhAGLU immunoglobulin G titers initially increased during the first 20 to 48 weeks of therapy but declined thereafter. There was no consistent difference in antibody formation comparing CRIM-negative with CRIM-positive patients. Muscle alpha-glucosidase activity increased from <2% to 10% to 20% of normal in all patients during the first 12 weeks of treatment with 15 to 20 mg/kg/week. For optimizing the effect, the dose was increased to 40 mg/kg/week. This resulted, 12 weeks later, in normal alpha-glucosidase activity levels, which were maintained until the last measurement in week 72. Importantly, all 4 patients, including the patient without any endogenous alpha-glucosidase (CRIM negative), revealed mature 76- and 70-kDa forms of -glucosidase on Western blot. Conversion of the 110-kDa precursor from milk to mature 76/70-kDa alpha-glucosidase provides evidence that the enzyme is targeted to lysosomes, where this proteolytic processing occurs. At baseline, patients had severe glycogen storage in the quadriceps muscle as revealed by strong periodic acid-Schiff--positive staining and lacework patterns in hematoxylin and eosin--stained tissue sections. The muscle pathology correlated at each time point with severity of signs. Periodic acid-Schiff intensity diminished and number of vacuoles increased during the first 12 weeks of treatment. Twelve weeks after dose elevation, we observed signs of muscle regeneration in 3 of the 4 patients. Obvious improvement of muscular architecture was seen only in the patient who learned to walk. Clinical effects were significant. All patients survived beyond the age of 4 years, whereas untreated patients succumb at a median age of 6 to 8 months. The characteristic cardiac hypertrophy present at start of treatment diminished significantly. The left ventricular mass index decreased from 171 to 599 g/m2 (upper limit of normal 86.6 g/m2 for infants from 0 to 1 year) to 70 to 160 g/m2 during 84 weeks of treatment. In addition, we found a significant change of slope for the diastolic thickness of the left ventricular posterior wall against time at t = 0 for each separate patient. Remarkably, the younger patients (patients 1 and 3) showed no significant respiratory problems during the first 2 years of life. One of the younger patients recovered from a life-threatening bronchiolitis at the age of 1 year without sequelae, despite borderline oxygen saturations at inclusion. At the age of 2, however, she became ventilator dependent after surgical removal of an infected Port-A-Cath. She died at the age of 4 years and 3 months suddenly after a short period of intractable fever of >42 degrees C, unstable blood pressure, and coma. The respiratory course of patient 1 remained uneventful. The 2 older patients, who both were hypercapnic (partial pressure of carbon dioxide: 10.6 and 9.8 kPa; normal range: 4.5-6.8 kPa) at start of treatment, became ventilator dependent before the first infusion (patient 2) and after 10 weeks of therapy (patient 4). Patient 4 was gradually weaned from the ventilator after 1 year of high-dose treatment and was eventually completely ventilator-free for 5 days, but this situation could not be maintained. Currently, both patients are completely ventilator dependent. The most remarkable progress in motor function was seen in the younger patients (patients 1 and 3). They achieved motor milestones that are unmet in infantile Pompe disease. Patient 1 learned to crawl (12 months), walk (16 months), squat (18 months), and climb stairs (22 months), and patient 3 learned to sit unsupported. The Alberta Infant Motor Scale score for patients 2, 3, and 4 remained far below p5. Patient 1 followed the p5 of normal. Our study shows that a safe and effective medicine can be produced in the milk of mammals and encourages additional development of enzyme replacement therapy for the several forms of Pompe disease. Restoration of skeletal muscle function and prevention of pulmonary insufficiency require dosing in the range of 20 to 40 mg/kg/week. The effect depends on residual muscle function at the start of treatment. Early start of treatment is required.

Effect of Box-Cox transformation on power of Haseman-Elston and maximum-likelihood variance components tests to detect quantitative trait Loci.

PubMed

Etzel, C J; Shete, S; Beasley, T M; Fernandez, J R; Allison, D B; Amos, C I

2003-01-01

Non-normality of the phenotypic distribution can affect power to detect quantitative trait loci in sib pair studies. Previously, we observed that Winsorizing the sib pair phenotypes increased the power of quantitative trait locus (QTL) detection for both Haseman-Elston (HE) least-squares tests [Hum Hered 2002;53:59-67] and maximum likelihood-based variance components (MLVC) analysis [Behav Genet (in press)]. Winsorizing the phenotypes led to a slight increase in type 1 error in H-E tests and a slight decrease in type I error for MLVC analysis. Herein, we considered transforming the sib pair phenotypes using the Box-Cox family of transformations. Data were simulated for normal and non-normal (skewed and kurtic) distributions. Phenotypic values were replaced by Box-Cox transformed values. Twenty thousand replications were performed for three H-E tests of linkage and the likelihood ratio test (LRT), the Wald test and other robust versions based on the MLVC method. We calculated the relative nominal inflation rate as the ratio of observed empirical type 1 error divided by the set alpha level (5, 1 and 0.1% alpha levels). MLVC tests applied to non-normal data had inflated type I errors (rate ratio greater than 1.0), which were controlled best by Box-Cox transformation and to a lesser degree by Winsorizing. For example, for non-transformed, skewed phenotypes (derived from a chi2 distribution with 2 degrees of freedom), the rates of empirical type 1 error with respect to set alpha level=0.01 were 0.80, 4.35 and 7.33 for the original H-E test, LRT and Wald test, respectively. For the same alpha level=0.01, these rates were 1.12, 3.095 and 4.088 after Winsorizing and 0.723, 1.195 and 1.905 after Box-Cox transformation. Winsorizing reduced inflated error rates for the leptokurtic distribution (derived from a Laplace distribution with mean 0 and variance 8). Further, power (adjusted for empirical type 1 error) at the 0.01 alpha level ranged from 4.7 to 17.3% across all tests using the non-transformed, skewed phenotypes, from 7.5 to 20.1% after Winsorizing and from 12.6 to 33.2% after Box-Cox transformation. Likewise, power (adjusted for empirical type 1 error) using leptokurtic phenotypes at the 0.01 alpha level ranged from 4.4 to 12.5% across all tests with no transformation, from 7 to 19.2% after Winsorizing and from 4.5 to 13.8% after Box-Cox transformation. Thus the Box-Cox transformation apparently provided the best type 1 error control and maximal power among the procedures we considered for analyzing a non-normal, skewed distribution (chi2) while Winzorizing worked best for the non-normal, kurtic distribution (Laplace). We repeated the same simulations using a larger sample size (200 sib pairs) and found similar results. Copyright 2003 S. Karger AG, Basel

Stellar neutron sources and s-process in massive stars

NASA Astrophysics Data System (ADS)

Talwar, Rashi

The s-process or the slow neutron capture process is a nucleosynthesis process taking place at relatively low neutron densities in stars. It runs along the valley of beta stability since the neutron capture rate is much slower compared to the beta decay rate. The s-process occurs mainly during core helium burning and shell carbon burning phase in massive stars and during thermally pulsing helium burning phase in asymptotic giant-branch stars. The potential stellar neutron source for the s-process is associated with alpha-capture reactions on light nuclei. The capture-reaction rates provide the reaction flow for the build-up of22Ne neutron source during the heliumburning phase in these stars. The low energy 26Mg resonances at stellar energies below 800 keV are predicted to have a critical influence on the alpha-capture rates on 22Ne. Some of these resonances may also correspond to pronounced alpha cluster structure near the alpha-threshold. However, these resonances have remained elusive during direct alpha capture measurements owing to the high Coulomb barrier and background from cosmic rays and beam induced reactions. Hence, in the present work, alpha-inelastic scattering and alpha- transfer measurements have been performed to probe the level structure of 26Mg nucleus in order to determine the 22Ne+alpha-capture rates. Both experiments have been performed using the high-resolution Grand Raiden Spectrometer at the Research Center for Nuclear Physics (RCNP), Osaka, Japan. For the alpha-inelastic scattering measurement, a self-supporting solid 26Mg target was used and for the alpha-transfer study via the (6Li,d) reaction, 22Ne gas enclosed in a gas cell with Aramid windows was used. The reaction products were momentum analysed by the spectrometer and detected at the focal plane equipped with two multi-wire drift chambers and two plastic-scintillation detectors. The focal plane detection system provided information on the position, the angle, the time of flight and the energy of the particles enabling the reconstruction of the kinematics at the target. The focal plane energy calibration allowed for the study of 26 Mg levels from Ex = 7.69 - 12.06 MeV in the (alpha; alpha0) measurement and Ex = 7.36 - 11.32 MeV in the (6Li,d) measurement. Six levels (Ex = 10717 (9) keV , 10822 (10) keV, 10951 (21) keV, 11085 (8) keV, 11167 (8) keV and 11317 (18) keV) were observed above the alpha-threshold in the region of interest (10.61 - 11.32 MeV). The Ex = 10717 keV had a negligible contribution to the alpha-capture rates. The Ex = 10951, 11167 and 11317 keV exhibited pronounced alpha-cluster structure and hence, dominated the alpha-capture rates. The Ex = 11167 keV had the most appreciable impact on the (alpha; gamma ) rate increasing it by 2 orders of magnitude above Longland et al. [58] and Bisterzo et al. [8] rates and by a factor of 3 above NACRE [2] rate. Hence, the recommended 22Ne(alpha,n) + 22Ne(alpha; ) rates, from the present work, strongly favour the reduction of s-process over-abundances associated with massive stars as well as AGB stars of intermediate initial mass. Also, the uncertainty range corresponding to the present rates suggest the need for a more refined measurement of the associated resonance parameters.

Anti-cytokine autoantibodies in autoimmunity: preponderance of neutralizing autoantibodies against interferon-alpha, interferon-omega and interleukin-12 in patients with thymoma and/or myasthenia gravis.

PubMed

Meager, A; Wadhwa, M; Dilger, P; Bird, C; Thorpe, R; Newsom-Davis, J; Willcox, N

2003-04-01

We have screened for spontaneous anticytokine autoantibodies in patients with infections, neoplasms and autoimmune diseases, because of their increasingly reported co-occurrence. We tested for both binding and neutralizing autoantibodies to a range of human cytokines, including interleukin-1alpha (IL-1alpha), IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-18, interferon-alpha2 (IFN-alpha2), IFN-omega, IFN-beta, IFN-gamma, tumour necrosis factor alpha (TNF-alpha), transforming growth factor beta-1 (TGF-beta1) and granulocyte-macrophage colony stimulating factor (GM-CSF), in plasmas or sera. With two notable exceptions described below, we found only occasional, mostly low-titre, non-neutralizing antibodies, mainly to GM-CSF; also to IL-10 in pemphigoid. Strikingly, however, high-titre, mainly IgG, autoantibodies to IFN-alpha2, IFN-omega and IL-12 were common at diagnosis in patients with late-onset myasthenia gravis (LOMG+), thymoma (T) but no MG (TMG-) and especially with both thymoma and MG together (TMG+). The antibodies recognized other closely related type I IFN-alpha subtypes, but rarely the distantly related type I IFN-beta, and never (detectably) the unrelated type II IFN-gamma. Antibodies to IL-12 showed a similar distribution to those against IFN-alpha2, although prevalences were slightly lower; correlations between individual titres against each were so modest that they appear to be entirely different specificities. Neither showed any obvious correlations with clinical parameters including thymoma histology and HLA type, but they did increase sharply if the tumours recurred. These antibodies neutralized their respective cytokine in bioassays in vitro; although they persisted for years severe infections were surprisingly uncommon, despite the immunosuppressive therapy also used in most cases. These findings must hold valuable clues to autoimmunizing mechanisms in paraneoplastic autoimmunity.

Expression of the transforming growth factor alpha protooncogene in differentiating human promyelocytic leukemia (HL-60) cells.

PubMed

Walz, T M; Malm, C; Wasteson, A

1993-01-01

The process of myeloid differentiation in human promyelocytic leukemia cells (HL-60) is accompanied by the coordinate expression of numerous protooncogenes. To investigate the expression of transforming growth factor alpha (TGF-alpha) in myeloid differentiation, HL-60 cells were induced to differentiate into granulocytes with 1.25% dimethyl sulfoxide, 0.2 microM all-trans retinoic acid, or 500 microM N6,O2-dibutyryladenosine-3'5'-cyclic monophosphate or differentiated along the monocyte/macrophage pathway with 0.1 microM phorbol-12-myristate-13-acetate. Using Northern blot analyses, TGF-alpha transcripts were detected within 24 h of treatment in cells differentiating toward granulocytes; maximal levels of gene expression were reached after 3 days or later and remained essentially constant throughout the observation period. These cells released TGF-alpha protein, as demonstrated by analysis of the incubation medium. In contrast, no TGF-alpha RNA or protein was detectable in HL-60 cell cultures when induced with phorbol-12-myristate-13-acetate. Epidermal growth factor receptor transcripts could not be detected either in undifferentiated or in differentiated HL-60 cells; therefore it appears as if an autocrine loop involving TGF-alpha in HL-60 cells is unlikely. In conclusion, the results demonstrate, for the first time, the expression of TGF-alpha in human granulocyte precursor cells. Our findings may indicate novel regulatory pathways in hematopoiesis.

Dose equivalent neutron dosimeter

DOEpatents

Griffith, Richard V.; Hankins, Dale E.; Tomasino, Luigi; Gomaa, Mohamed A. M.

1983-01-01

A neutron dosimeter is disclosed which provides a single measurements indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer containing conversion material such as .sup.6 Li and .sup.10 B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet. The density of conversion material in the radiator layer is of an amount which is chosen so that the density of tracks produced in the detecting sheet is proportional to the biological damage done by neutrons, regardless of whether the tracks are produced as the result of moderate energy neutrons striking the radiator layer or as the result of higher energy neutrons striking the sheet of track etch material.

The quantified EEG characteristics of responders and non-responders to long-term treatment with atomoxetine in children with attention deficit hyperactivity disorders.

PubMed

Chiarenza, Giuseppe Augusto; Chabot, Robert; Isenhart, Robert; Montaldi, Luciano; Chiarenza, Marco Paolo; Torto, Maria Grazia Lo; Prichep, Leslie S

2016-06-01

The aim of our study is to examine quantitative Electroencephalogram (QEEG) differences between ADHD patients that are responders and non-responders to long-term treatment with Atomoxetine at baseline and after 6 and 12months of treatment. Patients with attention deficit hyperactivity disorder (ADHD) received atomoxetine titrated, over 7days, from 0.5 to 1.2mg/kg/day. QEEG and Swanson, Nolan, and Pelham-IV Questionnaire (SNAP-IV) scores were recorded before treatment and after therapy. Twenty minutes of eyes closed resting EEG was recorded from 19 electrodes referenced to linked earlobes. Full frequency and narrow band spectra of two minutes of artifact-free EEG were computed as well as source localization using Variable Resolution Electrical Tomography (VARETA). Abnormalities were identified using Z-spectra relative to normative values. Patients were classified as responders, non-responders and partial responders based upon the SNAP-IV findings. At baseline, the responders showed increased absolute power in alpha and delta in frontal and temporal regions, whereas, non-responders showed increased absolute power in all frequency bands that was widely distributed. With treatment responders' absolute power values moved toward normal values, whereas, non-responders remained at baseline values. Patients with increased power in the alpha band with no evidence of alterations in the beta or theta range, might be responders to treatment with atomoxetine. Increased power in the beta band coupled with increased alpha seems to be related to non-responders and one should consider atomoxetine withdrawal, especially if there is persistence of increased alpha and beta accompanied by an increase of theta. Copyright © 2016 Elsevier B.V. All rights reserved.

Characterization of the key aroma compounds in dried fruits of the West African peppertree Xylopia aethiopica (Dunal) A. Rich (Annonaceae) using aroma extract dilution analysis.

PubMed

Tairu, A O; Hofmann, T; Schieberle, P

1999-08-01

Application of aroma extract dilution analysis on an extract of the dried fruits of the West African peppertree Xylopia aethiopica obtained by extraction with diethyl ether followed by sublimation in vacuo revealed 28 odor-active compounds in the flavor dilution (FD) factor range of 4-8192, all of which could be identified. The highest FD factor was found for linalol (floral), followed by (E)-beta-ocimene (flowery), alpha-farnesene (sweet, flowery), beta-pinene (terpeny), alpha-pinene (pine needle-like), myrtenol (flowery), and beta-phellandrene (terpeny). Vanillin (vanilla-like) and 3-ethylphenol (smoky, phenolic) showing somewhat lower FD factors (FD = 128) were detected for the first time as constituents of the dried fruit.

Magnetic Field Configuration of Active Region NOAA 6555 at the Time of a Long Duration Flare on 23 March 1991: An Exception to Standard Flare Reconnection Model

NASA Technical Reports Server (NTRS)

Choudhary, Debi Prasad; Gary, Allen G.

1998-01-01

The high-resolution H(sub alpha) images observed during the decay phase of a long duration flare on 23 March 1991 are used to study the three-dimensional magnetic field configuration of the active region NOAA 6555. Whereas, all the large flares in NOAA 6555 occurred at the location of high magnetic shear and flux emergence, this long duration flare was observed in the region of low magnetic shear at the photosphere. The H(sub alpha) loop activity started soon after the maximum phase of the flare. There were few long loop at the initial phase of the activity. Some of these were sheared in the chromosphere at an angle of about 45 deg with the east-west axis. Gradually, increasing number of shorter loops, oriented along the east-west axis, started appearing. The chromospheric Dopplergrams show blue-shifts at the end points of the loops. By using different magnetic field models, we have extrapolated the photospheric magnetograms to the chromospheric heights. The magnetic field lines computed by using the potential field model correspond to most of the observed H(sub alpha) loops. The height of the H(sub alpha) loops were derived by comparing them with the computed field lines. From the temporal evolution of the H(sub alpha) loop activity, we derive the negative rate of appearance of H(sub alpha) features as a function of height. It is found that the field lines oriented along one of the neutral lines was sheared and low lying. The higher field lines were mostly potential. The paper also outlines a possible scenario for describing the post-flare stage of the observed long duration flare.

Serum and Urinary Levels of Tumor Necrosis Factor-Alpha in Renal Transplant Patients.

PubMed

Senturk Ciftci, Hayriye; Demir, Erol; Savran Karadeniz, Meltem; Tefik, Tzevat; Yazici, Halil; Nane, Ismet; Savran Oguz, Fatma; Aydin, Filiz; Turkmen, Aydin

2017-12-18

Allograft rejection is an important cause of early and long-term graft loss in kidney transplant recipients. Tumor necrosis factor-alpha promotes T-cell activation, the key reaction leading to allograft rejection. Here, we investigated whether serum and urinary tumor necrosis factor-alpha levels can predict allograft rejection. This study included 65 living related-donor renal transplant recipients with mean follow-up of 26 ± 9 months. Serum and urinary tumor necrosis factor-alpha levels were measured at pretransplant and at posttransplant time points (days 1 and 7 and months 3 and 6); serum creatinine levels were also monitored during posttransplant follow-up. Standard enzyme-linked immunoabsorbent assay was used to detect tumor necrosis factor-alpha levels. Clinical variables were monitored. Nine of 65 patients (13.8%) had biopsy-proven rejection during follow-up. Preoperative serum and urinary tumor necrosis factor-alpha levels were not significantly different when we compared patients with and without rejection. Serum tumor necrosis factor-alpha levels (in pg/mL) were significantly higher in the allograft rejection versus nonrejection group at day 7 (11.5 ± 4.7 vs 15.4 ± 5.8; P = .029) and month 1 (11.1 ± 4.8 vs 17.8 ± 10.9; P =.003). Urinary tumor necrosis factor-alpha levels (in pg/mL) were also elevated in the allograft rejection versus the nonrejection group at days 1 (10.2 ± 2.5 vs 14.1 ± 6.8; P = .002) and 7 (9.8 ± 2.2 vs 14.5 ± 2.7; P < .001) and at months 1 (8.0 ± 1.7 vs 11.8 ± 2.4; P < .001), 3 (7.7 ± 1.6 vs 9.6 ± 1.7; P = .002), and 6 (7.4 ± 1.6 vs 8.9 ± 0.9; P = .005). Our preliminary findings suggest that tumor necrosis factor-alpha has a role in diagnosing renal transplant rejection. Serum and urinary tumor necrosis factor-alpha levels may be a possible predictor for allograft rejection.

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity

PubMed Central

1984-01-01

The processing of asparagine-linked oligosaccharides on the alpha- chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N- acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin. PMID:6420419

Processing of MOPC 315 immunoglobulin A oligosaccharides: evidence for endoplasmic reticulum and trans Golgi alpha 1,2-mannosidase activity.

PubMed

Hickman, S; Theodorakis, J L; Greco, J M; Brown, P H

1984-02-01

The processing of asparagine-linked oligosaccharides on the alpha-chains of an immunoglobulin A (IgA) has been investigated using MOPC 315 murine plasmacytoma cells. These cells secrete IgA containing complex-type oligosaccharides that were not sensitive to endo-beta-N-acetylglucosaminidase H. In contrast, oligosaccharides present on the intracellular alpha-chain precursor were of the high mannose-type, remaining sensitive to endo-beta-N-acetylglucosaminidase H despite a long intracellular half-life of 2-3 h. The major [3H]mannose-labeled alpha-chain oligosaccharides identified after a 20-min pulse were Man8GlcNAc2 and Man9GlcNAc2. Following chase incubations, the major oligosaccharide accumulating intracellularly was Man6GlcNAc2, which was shown to contain a single alpha 1,2-linked mannose residue. Conversion of Man6GlcNAc2 to complex-type oligosaccharides occurred at the time of secretion since appreciable amounts of Man5GlcNAc2 or further processed structures could not be detected intracellularly. The subcellular locations of the alpha 1,2-mannosidase activities were studied using carbonyl cyanide m-chlorophenylhydrazone and monensin. Despite inhibiting the secretion of IgA, these inhibitors of protein migration did not effect the initial processing of Man9GlcNAc2 to Man6GlcNAc2. Furthermore, no large accumulation of Man5GlcNAc2 occurred, indicating the presence of two subcellular locations of alpha 1,2-mannosidase activity involved in oligosaccharide processing in MOPC 315 cells. Thus, the first three alpha 1,2-linked mannose residues were removed shortly after the alpha-chain was glycosylated, most likely in rough endoplasmic reticulum, since this processing occurred in the presence of carbonyl cyanide m-chlorophenylhydrazone. However, the removal of the final alpha 1,2-linked mannose residue as well as subsequent carbohydrate processing occurred just before IgA secretion, most likely in the trans Golgi complex since processing of Man6GlcNAc2 to Man5GlcNAc2 was greatly inhibited in the presence of monensin.

CMOS sensor as charged particles and ionizing radiation detector

NASA Astrophysics Data System (ADS)

Cruz-Zaragoza, E.; Piña López, I.

2015-01-01

This paper reports results of CMOS sensor suitable for use as charged particles and ionizing radiation detector. The CMOS sensor with 640 × 480 pixels area has been integrated into an electronic circuit for detection of ionizing radiation and it was exposed to alpha particle (Am-241, Unat), beta (Sr-90), and gamma photons (Cs-137). Results show after long period of time (168 h) irradiation the sensor had not loss of functionality and also the energy of the charge particles and photons were very well obtained.

Transferred nuclear Overhauser enhancement experiments show that the monoclonal antibody strep 9 selects a local minimum conformation of a Streptococcus group A trisaccharide-hapten.

PubMed

Weimar, T; Harris, S L; Pitner, J B; Bock, K; Pinto, B M

1995-10-17

Transferred nuclear Overhauser enhancement (TRNOE) experiments have been performed to investigate the bound conformation of the trisaccharide repeating unit of the Streptococcus Group A cell-wall polysaccharide. Thus, the conformations of propyl 3-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-2-O-(alpha-L-rhamnopyran osyl)- alpha-L-rhamnopyranoside [C(A')B] (1) as a free ligand and when complexed to the monoclonal antibody Strep 9 were examined. Improved insights about the conformational preferences of the glycosidic linkages of the trisaccharide ligand showed that the free ligand populates various conformations in aqueous solution, thus displaying relatively flexible behavior. The NOE HNAc-H2A', which was not detected in previous work, accounts for a conformation at the beta-(1-->3) linkage with a phi angle of approximately 180 degrees. Observed TRNOEs for the complex are weak, and their analysis was further complicated by spin diffusion. With the use of transferred rotating-frame Overhauser enhancement (TRROE) experiments, the amount of spin diffusion was assessed experimentally, proving that all of the observed long-range TRNOEs arose through spin diffusion. Four interglycosidic distances, derived from the remaining TRNOEs and TRROEs, together with repulsive constraints, derived from the absence of TRROE effects, were used as input parameters in simulated annealing and molecular mechanics calculations to determine the bound conformation of the trisaccharide. Complexation by the antibody results in the selection of one defined conformation of the carbohydrate hapten. This bound conformation, which is a local energy minimum on the energy maps calculated for the trisaccharide ligand, shows only a change from a +gauche to a -gauche orientation at the psi angle of the alpha-(1-->2) linkage when compared to the global minimum conformation. The results infer that the bound conformation of the Streptococcus Group A cell-wall polysaccharide is different from its previously proposed solution structure (Kreis et al., 1995).

Hereditary alpha-1-antitrypsin deficiency and its clinical consequences.

PubMed

Fregonese, Laura; Stolk, Jan

2008-06-19

Alpha-1-antitrypsin deficiency (AATD) is a genetic disorder that manifests as pulmonary emphysema, liver cirrhosis and, rarely, as the skin disease panniculitis, and is characterized by low serum levels of AAT, the main protease inhibitor (PI) in human serum. The prevalence in Western Europe and in the USA is estimated at approximately 1 in 2,500 and 1 : 5,000 newborns, and is highly dependent on the Scandinavian descent within the population. The most common deficiency alleles in North Europe are PI Z and PI S, and the majority of individuals with severe AATD are PI type ZZ. The clinical manifestations may widely vary between patients, ranging from asymptomatic in some to fatal liver or lung disease in others. Type ZZ and SZ AATD are risk factors for the development of respiratory symptoms (dyspnoea, coughing), early onset emphysema, and airflow obstruction early in adult life. Environmental factors such as cigarette smoking, and dust exposure are additional risk factors and have been linked to an accelerated progression of this condition. Type ZZ AATD may also lead to the development of acute or chronic liver disease in childhood or adulthood: prolonged jaundice after birth with conjugated hyperbilirubinemia and abnormal liver enzymes are characteristic clinical signs. Cirrhotic liver failure may occur around age 50. In very rare cases, necrotizing panniculitis and secondary vasculitis may occur. AATD is caused by mutations in the SERPINA1 gene encoding AAT, and is inherited as an autosomal recessive trait. The diagnosis can be established by detection of low serum levels of AAT and isoelectric focusing. Differential diagnoses should exclude bleeding disorders or jaundice, viral infection, hemochromatosis, Wilson's disease and autoimmune hepatitis. For treatment of lung disease, intravenous alpha-1-antitrypsin augmentation therapy, annual flu vaccination and a pneumococcal vaccine every 5 years are recommended. Relief of breathlessness may be obtained with long-acting bronchodilators and inhaled corticosteroids. The end-stage liver and lung disease can be treated by organ transplantation. In AATD patients with cirrhosis, prognosis is generally grave.

Distribution of alpha3, alpha5 and alpha(v) integrin subunits in mature and immature human oocytes.

PubMed

Capmany, G; Mart, M; Santaló, J; Bolton, V N

1998-10-01

The distribution of three integrin subunits, alpha3, alpha5 and alpha(v), in immature and mature human oocytes has been examined using immunofluorescence and confocal microscopy. The results demonstrate that both alpha5 and alpha(v) are present at the germinal vesicle stage, while alpha3 was only detected in oocytes after germinal vesicle breakdown, in metaphase I and II stage oocytes. The cortical concentration of integrin subunits alpha3 and alpha5 is consistent with their localization in the oolemma. In contrast, the homogeneous distribution of alpha(v) throughout the oocyte suggests the existence of cytoplasmic reservoirs of this protein in the oocyte.

Cs 62 DJ Rydberg-atom macrodimers formed by long-range multipole interaction

NASA Astrophysics Data System (ADS)

Han, Xiaoxuan; Bai, Suying; Jiao, Yuechun; Hao, Liping; Xue, Yongmei; Zhao, Jianming; Jia, Suotang; Raithel, Georg

2018-03-01

Long-range macrodimers formed by D -state cesium Rydberg atoms are studied in experiments and calculations. Cesium [62DJ]2 Rydberg-atom macrodimers, bonded via long-range multipole interaction, are prepared by two-color photoassociation in a cesium atom trap. The first color (pulse A) resonantly excites seed Rydberg atoms, while the second (pulse B, detuned by the molecular binding energy) resonantly excites the Rydberg-atom macrodimers below the [62DJ]2 asymptotes. The molecules are measured by extraction of autoionization products and Rydberg-atom electric-field ionization, and ion detection. Molecular spectra are compared with calculations of adiabatic molecular potentials. From the dependence of the molecular signal on the detection delay time, the lifetime of the molecules is estimated to be 3 -6 μ s .

[Effect of Yiguan Decoction on differentiation of bone marrow mesenchymal stem cells into hepatocyte-like cells: an experimental research].

PubMed

Ping, Jian; Chen, Hong-Yun; Yang, Zhou; Yang, Cheng; Xu, Lie-Ming

2014-03-01

To observe the effect of Yiguan Decoction (YGD) on differentiation of bone marrow mesenchymal stem cells (BMSCs) into hepatocyte-like cells in vitro. Rat BMSCs were isolated using whole bone marrow adherent method. The properties of BMSCs were identified by analyzing the expression of surface cytokines by flow cytometry. The third passage cells were differentiated into fat cells to identify their features. BMSCs were incubated with hepatocyte growth factor (HGF) plus fibroblast growth factor 4 (FGF4) or YGD containing serum YGD for 21 days. The mRNA expression of alpha-fetoprotein (alphaAFP), albumin (Alb), and hepatocyte nuclear factor 4alpha (HNF4alpha) were detected by real time PCR. Expression of AFP and cytokeratin 18 (CK18) protein was detected by cell immunofluorescence. Glycogen synthesis was observed using periodic acid-Schiff stain (PAS). CK18, Wnt 3alpha, and alphacatenin protein expressions were detected by Western blot. High expression of CD90, CD29, and CD44, and low expression of CD34 and CD11b were observed in BMSCs isolated by whole bone mar- row adherent method, and numerous lipid droplets were observed in BMSCs using oil red O staining. Both YGD containing serum and growth factor stimulated the expression levels of Alb, AFP, HNF4alpha mRNA and CK18 protein. The down-regulated expression of Wnt 3alpha and beta-catenin could be detected at 21 days after induction. The synthesized glycogen granule could be seen. Down-regulated Wnt 3alpha and beta-catenin expression could also be observed. YGD could induce the differentiation of rat BMSCs into hepatocyte-like cells, which was related to down-regulating Wnt/beta-catenin signal pathway.

SU-E-J-03: A Comprehensive Comparison Between Alpha and Beta Emitters for Cancer Radioimmunotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, C.Y.; Guatelli, S; Oborn, B

2014-06-01

Purpose: The purpose of this study is to perform a comprehensive comparison of the therapeutic efficacy and cytotoxicity of alpha and beta emitters for Radioimmunotherapy (RIT). For each stage of cancer development, specific models were built for the separate objectives of RIT to be addressed:a) kill isolated cancer cells in transit in the lymphatic and vascular circulation,b) regress avascular cell clusters,c) regress tumor vasculature and tumors. Methods: Because of the nature of short range, high LET alpha and long energy beta radiation and heterogeneous antigen expression among cancer cells, the microdosimetric approach is essential for the RIT assessment. Geant4 basedmore » microdosimetric models are developed for the three different stages of cancer progression: cancer cells, cell clusters and tumors. The energy deposition, specific energy resulted from different source distribution in the three models was calculated separately for 4 alpha emitting radioisotopes ({sup 211}At, {sup 213}Bi, {sup 223}Ra and {sup 225}Ac) and 6 beta emitters ({sup 32}P, {sup 33}P, {sup 67}Cu, {sup 90}Y, {sup 131}I and {sup 177}Lu). The cell survival, therapeutic efficacy and cytotoxicity are determined and compared between alpha and beta emitters. Results: We show that internal targeted alpha radiation has advantages over beta radiation for killing isolated cancer cells, regressing small cell clusters and also solid tumors. Alpha particles have much higher dose specificity and potency than beta particles. They can deposit 3 logs more dose than beta emitters to single cells and solid tumor. Tumor control probability relies on deep penetration of radioisotopes to cancer cell clusters and solid tumors. Conclusion: The results of this study provide a quantitative understanding of the efficacy and cytotoxicity of RIT for each stage of cancer development.« less

Local Control of Lung Derived Tumors by Diffusing Alpha-Emitting Atoms Released From Intratumoral Wires Loaded With Radium-224

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooks, Tomer; Schmidt, Michael; Bittan, Hadas

2009-07-01

Purpose: Diffusing alpha-emitters radiation therapy (DART) is a new form of brachytherapy enabling the treatment of solid tumors with alpha radiation. The present study examines the antitumoral effects resulting from the release of alpha emitting radioisotopes into solid lung carcinoma (LL2, A427, and NCI-H520). Methods and Materials: An in vitro setup tested the dose-dependent killing of tumor cells exposed to alpha particles. In in vivo studies, radioactive wires (0.3 mm diameter, 5 mm long) with {sup 224}Ra activities in the range of 21-38 kBq were inserted into LL/2 tumors in C57BL/6 mice and into human-derived A427 or NCI-H520 tumors inmore » athymic mice. The efficacy of the short-lived daughters of {sup 224}Ra to produce tumor growth retardation and prolong life was assessed, and the spread of radioisotopes inside tumors was measured using autoradiography. Results: The insertion of a single DART wire into the center of 6- to 7-mm tumors had a pronounced retardation effect on tumor growth, leading to a significant inhibition of 49% (LL2) and 93% (A427) in tumor development and prolongations of 48% (LL2) in life expectancy. In the human model, more than 80% of the treated tumors disappeared or shrunk. Autoradiographic analysis of the treated sectioned tissue revealed the intratumoral distribution of the radioisotopes, and histological analysis showed corresponding areas of necrosis. In vitro experiments demonstrated a dose-dependent killing of tumors cells exposed to alpha particles. Conclusions: Short-lived diffusing alpha-emitters produced tumor growth retardation and increased survival in mice bearing lung tumor implants. These results justify further investigations with improved dose distributions.« less

Interferon-alpha 2b quantification in inclusion bodies using reversed phase-ultra performance liquid chromatography (RP-UPLC).

PubMed

Cueto-Rojas, H F; Pérez, N O; Pérez-Sánchez, G; Ocampo-Juárez, I; Medina-Rivero, E

2010-04-15

Interferon-alpha 2b (IFN-alpha 2b) is a recombinant therapeutic cytokine produced as inclusion bodies using a strain of Escherichia coli as expression system. After fermentation and recovery, it is necessary to know the amount of recombinant IFN-alpha 2b, in order to determine the yield and the load for solubilization, and chromatographic protein purification steps. The present work details the validation of a new short run-time and fast sample-preparation method to quantify IFN-alpha 2b in inclusion bodies using Reversed Phase-Ultra Performance Liquid Chromatography (RP-UPLC). The developed method demonstrated an accuracy of 100.28%; the relative standard deviations for method precision, repeatability and inter-day precision tests were found to be 0.57%, 1.54% and 1.83%, respectively. Linearity of the method was assessed in the range of concentrations from 0.05 mg/mL to 0.5 mg/mL, the curve obtained had a determination coefficient (r(2)) of 0.9989. Detection and quantification limits were found to be 0.008 mg/mL and 0.025 mg/mL, respectively. The method also demonstrated robustness for changes in column temperature, and specificity against host proteins and other recombinant protein expressed in the same E. coli strain. Copyright 2010 Elsevier B.V. All rights reserved.

Rapid modification in the olfactory signal of ants following a change in reproductive status

NASA Astrophysics Data System (ADS)

Cuvillier-Hot, Virginie; Renault, Valérie; Peeters, Christian

2005-02-01

In insect societies, the presence and condition of egg-layers can be assessed with pheromones. Exocrine secretions are expected to vary in time in order to give up-to-date information on an individual’s reproductive physiology. In the queenless monogynous ant Streblognathus peetersi, we allowed a previously infertile high-ranking worker to accede to the alpha rank, thus triggering the onset of her oogenesis (15 replicates). We then studied her interactions with an established egg-layer from the same colony after different durations, ranging from 20 h to several days. Even though her eggs are only ready to be laid after 30 days, the new alpha was recognised within 1 2 days. Detection occurred at a distance of a few millimetres, suggesting the involvement of a pheromone with low volatility, such as cuticular hydrocarbons. When the new alpha had differentiated for >48 h, she was attacked by the established egg-layer. In all cases, low-ranking workers eventually immobilised one of the two alphas: the new alpha was the target if she had differentiated only recently, suggesting that police workers select the dominant worker with the “less fertile” odour. Using the behaviour of ants as our measure, we demonstrate that a dominant’s olfactory signal changes rapidly with a modification in her social status, and it occurs well before the onset of egg-laying.

The shortened food expectations--Long-term care questionnaire: Assessing nursing home residents' satisfaction with food and food service.

PubMed

Crogan, Neva L; Evans, Bronwynne C

2006-11-01

Lack of nursing home resident satisfaction with meals often results in reduced food intake, leading to poor nutritional status, weight loss, functional decline, and depression. The purpose of this article is to describe the development and initial testing of the 28-item revised Food Expectations-Long-Term Care (FoodEx-LTC) questionnaire with a convenience sample of nursing home residents (N = 61). Because of possible respondent burden, the original 44-item, five-domain FoodEx-LTC was revised, resulting in the deletion of 16 redundant items and those with inter-item correlations less than .25. Coefficient alpha scores ranged from .65 to .82, and test-retest correlations ranged from .79 to .88, dependent on domain. This revised instrument has good initial validity and reliability, resulting in a shorter instrument that accurately assesses nursing home resident satisfaction with food and food service.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swarnkar, Abhishek; Marshall, Ashley R.; Sanehira, Erin M.

Here, we show nanoscale phase stabilization of CsPbI 3 quantum dots (QDs) to low temperatures that can be used as the active component of efficient optoelectronic devices. CsPbI 3 is an all-inorganic analog to the hybrid organic cation halide perovskites, but the cubic phase of bulk CsPbI3 (..alpha..-CsPbI 3) -- the variant with desirable band gap -- is only stable at high temperatures. We also describe the formation of ..alpha..-CsPbI 3 QD films that are phase-stable for months in ambient air. The films exhibit long-range electronic transport and were used to fabricate colloidal perovskite QD photovoltaic cells with an open-circuitmore » voltage of 1.23 volts and efficiency of 10.77%. Furthermore, these devices function as light-emitting diodes with low turn-on voltage and tunable emission.« less

Cloning and purification of alpha-neurotoxins from king cobra (Ophiophagus hannah).

PubMed

He, Ying-Ying; Lee, Wei-Hui; Zhang, Yun

2004-09-01

Thirteen complete and three partial cDNA sequences were cloned from the constructed king cobra (Ophiophagus hannah) venom gland cDNA library. Phylogenetic analysis of nucleotide sequences of king cobra with those from other snake venoms revealed that obtained cDNAs are highly homologous to snake venom alpha-neurotoxins. Alignment of deduced mature peptide sequences of the obtained clones with those of other reported alpha-neurotoxins from the king cobra venom indicates that our obtained 16 clones belong to long-chain neurotoxins (seven), short-chain neurotoxins (seven), weak toxin (one) and variant (one), respectively. Up to now, two out of 16 newly cloned king cobra alpha-neurotoxins have identical amino acid sequences with CM-11 and Oh-6A/6B, which have been characterized from the same venom. Furthermore, five long-chain alpha-neurotoxins and two short-chain alpha-neurotoxins were purified from crude venom and their N-terminal amino acid sequences were determined. The cDNAs encoding the putative precursors of the purified native peptide were also determined based on the N-terminal amino acid sequencing. The purified alpha-neurotoxins showed different lethal activities on mice.

CPT1{alpha} over-expression increases long-chain fatty acid oxidation and reduces cell viability with incremental palmitic acid concentration in 293T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jambor de Sousa, Ulrike L.; Koss, Michael D.; Fillies, Marion

2005-12-16

To test the cellular response to an increased fatty acid oxidation, we generated a vector for an inducible expression of the rate-limiting enzyme carnitine palmitoyl-transferase 1{alpha} (CPT1{alpha}). Human embryonic 293T kidney cells were transiently transfected and expression of the CPT1{alpha} transgene in the tet-on vector was activated with doxycycline. Fatty acid oxidation was measured by determining the conversion of supplemented, synthetic cis-10-heptadecenoic acid (C17:1n-7) to C15:ln-7. CPT1{alpha} over-expression increased mitochondrial long-chain fatty acid oxidation about 6-fold. Addition of palmitic acid (PA) decreased viability of CPT1{alpha} over-expressing cells in a concentration-dependent manner. Both, PA and CPT1{alpha} over-expression increased cell death. Interestingly,more » PA reduced total cell number only in cells over-expressing CPT1{alpha}, suggesting an effect on cell proliferation that requires PA translocation across the mitochondrial inner membrane. This inducible expression system should be well suited to study the roles of CPT1 and fatty acid oxidation in lipotoxicity and metabolism in vivo.« less

THE STELLAR INITIAL MASS FUNCTION OF ULTRA-FAINT DWARF GALAXIES: EVIDENCE FOR IMF VARIATIONS WITH GALACTIC ENVIRONMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Geha, Marla; Brown, Thomas M.; Tumlinson, Jason

2013-07-01

We present constraints on the stellar initial mass function (IMF) in two ultra-faint dwarf (UFD) galaxies, Hercules and Leo IV, based on deep Hubble Space Telescope Advanced Camera for Surveys imaging. The Hercules and Leo IV galaxies are extremely low luminosity (M{sub V} = -6.2, -5.5), metal-poor (([Fe/H]) = -2.4, -2.5) systems that have old stellar populations (>11 Gyr). Because they have long relaxation times, we can directly measure the low-mass stellar IMF by counting stars below the main-sequence turnoff without correcting for dynamical evolution. Over the stellar mass range probed by our data, 0.52-0.77 M{sub Sun }, the IMFmore » is best fit by a power-law slope of {alpha}= 1.2{sub -0.5}{sup +0.4} for Hercules and {alpha} = 1.3 {+-} 0.8 for Leo IV. For Hercules, the IMF slope is more shallow than a Salpeter ({alpha} = 2.35) IMF at the 5.8{sigma} level, and a Kroupa ({alpha} = 2.3 above 0.5 M{sub Sun }) IMF slope at 5.4{sigma} level. We simultaneously fit for the binary fraction, f{sub binary}, finding f{sub binary}= 0.47{sup +0.16}{sub -0.14} for Hercules, and 0.47{sup +0.37}{sub -0.17} for Leo IV. The UFD binary fractions are consistent with that inferred for Milky Way stars in the same mass range, despite very different metallicities. In contrast, the IMF slopes in the UFDs are shallower than other galactic environments. In the mass range 0.5-0.8 M{sub Sun }, we see a trend across the handful of galaxies with directly measured IMFs such that the power-law slopes become shallower (more bottom-light) with decreasing galactic velocity dispersion and metallicity. This trend is qualitatively consistent with results in elliptical galaxies inferred via indirect methods and is direct evidence for IMF variations with galactic environment.« less

Study on molecular epidemiology of the alpha-thalassemias in Liuzhou City, Guangxi Autonomous Region, China.

PubMed

Cai, Ren; Liu, Jingzhong; Wang, Lirong; Liang, Xin; Xiao, Bai; Su, Liu; Zhou, Yan; Pan, Lizhen

2004-01-01

Guangxi is one of the provinces of Southern China with the highest incidence of alpha-thalassemia (thal). Liuzhou is the second biggest city in Guangxi. To find out the incidence of the various alpha-thal genotypes, and their distribution in the Liuzhou area, an F820 Blood Cell Analysis System was used to measure the parameters of red blood cells. A SPIFE Rapid Auto-Electrophoresis System was used to analyze the normal and abnormal hemoglobins (Hbs). Multiplex polymerase chain reaction (mPCR) was used to detect the alpha-globin genotypes. Thirty-two (2.05%) out of 7805 young couples undergoing pre-marriage counseling, were diagnosed as having an Hb H (beta4) disease. The study of 1228 cord blood samples revealed 138 newborn children carrying an alpha-thal determinant with nine different genotypes, thus making the total incidence of alpha-thal 11.24%. Among 185 cases of Hb H, 119 (64.1%) were confirmed as being deletional, and 66 cases (35.7%) nondeletional types. The severity of the Hb H diseases could be classified in the following order: alphaCSalpha/--SEA (alphaConstant (Spring)alpha/--Southeast Asia); alpha(-4.2)/--SEA; alpha(-3.7)/--SEA. Ten cases of alpha-thal determinants were found in combination with beta-thal. The mPCR technique can detect all kinds of combinations of the three common large deletions (--SEA, alpha(-4.2) and alpha(-3.7)) accurately and conveniently.

Development of graphite carbon nitride based fluorescent immune sensor for detection of alpha fetoprotein

NASA Astrophysics Data System (ADS)

Li, Yike; Dong, Lingyu; Wang, Xiangfeng; Liu, Yuan; Liu, Hailing; Xie, Mengxia

2018-05-01

A novel fluorescent immunosensor for determination of alpha fetoprotein (AFP) in serum samples has been developed based on the nano graphite carbon nitride (g-C3N4) as fluorophore and immunomagnetic beads (MBs) as separation material. The bulk g-C3N4 was obtained by thermal polymerization of melamine, and then carboxylated and exfoliated to acquire the carboxylated nano g-C3N4 (c-n-g-C3N4), which has been characterized and the results showed that it had excellent fluorescent properties. The antibodies of AFP (Ab1, Ab2) were conjugated to the MBs and the c-n-g-C3N4, respectively. In assay of AFP detection, the magnetic part of the immunosensor, MBs-Ab1, would form the sandwich type complex with the signal part of the sensor, c-n-g-C3N4-Ab2. The developed immunosensor could simplify the process of separation due to the MBs. The results illustrated that proposed approach held a good linearity between the fluorescence intensity of the sensor and the AFP concentration ranging from 5-600 ng/mL with the limit of detection as low as 0.43 ng/mL, and its spiking recoveries ranged from 98.2% to 105.9% with RSD from 2.1% to 3.5%. The fabricated fluorescent immunosensor possesses the merits of good sensitivity, excellent selectivity, high biocompatibility and low cost, and the results provide a novel clue to develop immunosensor for determination of the biomarkers in complex matrices.

Development of a homogeneous pulse shape discriminating flow-cell radiation detection system

NASA Astrophysics Data System (ADS)

Hastie, K. H.; DeVol, T. A.; Fjeld, R. A.

1999-02-01

A homogeneous flow-cell radiation detection system which utilizes coincidence counting and pulse shape discrimination circuitry was assembled and tested with five commercially available liquid scintillation cocktails. Two of the cocktails, Ultima Flo (Packard) and Mono Flow 5 (National Diagnostics) have low viscosities and are intended for flow applications; and three of the cocktails, Optiphase HiSafe 3 (Wallac), Ultima Gold AB (Packard), and Ready Safe (Beckman), have higher viscosities and are intended for static applications. The low viscosity cocktails were modified with 1-methylnaphthalene to increase their capability for alpha/beta pulse shape discrimination. The sample loading and pulse shape discriminator setting were optimized to give the lowest minimum detectable concentration for alpha radiation in a 30 s count time. Of the higher viscosity cocktails, Optiphase HiSafe 3 had the lowest minimum detectable activities for alpha and beta radiation, 0.2 and 0.4 Bq/ml for 233U and 90Sr/ 90Y, respectively, for a 30 s count time. The sample loading was 70% and the corresponding alpha/beta spillover was 5.5%. Of the low viscosity cocktails, Mono Flow 5 modified with 2.5% (by volume) 1-methylnaphthalene resulted in the lowest minimum detectable activities for alpha and beta radiation; 0.3 and 0.5 Bq/ml for 233U and 90Sr/ 90Y, respectively, for a 30 s count time. The sample loading was 50%, and the corresponding alpha/beta spillover was 16.6%. HiSafe 3 at a 10% sample loading was used to evaluate the system under simulated flow conditions.

Diagnostic performance of tumor markers AFP and PIVKA-II in Chinese hepatocellular carcinoma patients.

PubMed

Huang, Shujing; Jiang, Feifei; Wang, Ying; Yu, Yanhua; Ren, Siqian; Wang, Xiaowei; Yin, Peng; Lou, Jinli

2017-06-01

Alpha-fetoprotein is an effective biomarker as an aid in hepatocellular carcinoma detection in many countries. However, alpha-fetoprotein has its limitations, especially in early hepatocellular carcinoma diagnosis. Protein induced by vitamin K absence or antagonist-II is another biomarker that is used for hepatocellular carcinoma detection. The aim of this study is to compare the diagnostic performance of alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II alone and in combination to explore improving biomarker performance as an aid in early hepatocellular carcinoma detection. In this study a total of 582 serum samples including 132 hepatocellular carcinoma patients, 250 non-hepatocellular carcinoma patients, and 200 healthy volunteers were collected. Alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II levels were measured by both chemiluminescent enzyme immunoassay on LUMIPULSE platform and by chemiluminescent microparticle immunoassay on ARCHITECT platform. Receiver operation characteristic curve analyses were performed for each biomarker and in combination. The results showed that Alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II in combination have shown higher area under the curve compared to alpha-fetoprotein alone for diagnosis in whole patients (0.906 vs 0.870) in hepatocellular carcinoma early-stage patients (0.809 vs 0.77) and in hepatitis B virus-related hepatocellular carcinoma patients (0.851 vs 0.788) with ARCHITECT platform. Protein induced by vitamin K absence or antagonist-II showed higher area under the curve than alpha-fetoprotein for diagnosis of hepatitis B virus-related hepatocellular carcinoma patients (0.901 vs 0.788).We conclude that Combining alpha-fetoprotein and protein induced by vitamin K absence or antagonist-II may improve the diagnostic value for early detection of hepatocellular carcinoma. Protein induced by vitamin K absence or antagonist-II performs better than alpha-fetoprotein in diagnosis of hepatitis B virus-related hepatocellular carcinoma patients.

Large-area imager of hydrogen leaks in fuel cells using laser-induced breakdown spectroscopy.

PubMed

Hori, M; Hayano, R S; Fukuta, M; Koyama, T; Nobusue, H; Tanaka, J

2009-10-01

We constructed a simple device, which utilized laser-induced breakdown spectroscopy to image H2 gas leaking from the surfaces of hydrogen fuel cells to ambient air. Nanosecond laser pulses of wavelength lambda=532 nm emitted from a neodymium-doped yttrium aluminum garnet laser were first compressed to a pulse length Deltat<1 ns using a stimulated Brillouin backscattering cell. Relay-imaging optics then focused this beam onto the H(2) leak and initiated the breakdown plasma. The Balmer-alpha (H-alpha) emission that emerged from this was collected with a 2-m-long macrolens assembly with a 90-mm-diameter image area, which covered a solid angle of approximately 1 x 10(-3)pi steradians seen from the plasma. The H-alpha light was isolated by two 100-mm-diameter interference filters with a 2 nm bandpass, and imaged by a thermoelectrically cooled charge-coupled device camera. By scanning the position of the laser focus, the spatial distribution of H2 gas over a 90-mm-diameter area was photographed with a spatial resolution of < or = 5 mm. Photoionization of the water vapor in the air caused a strong H-alpha background. By using pure N2 as a buffer gas, H2 leaks with rates of <1 cc/min were imaged. We also studied the possibilities of detecting He, Ne, or Xe gas leaks.

Simplified fast neutron dosimeter

DOEpatents

Sohrabi, Mehdi

1979-01-01

Direct fast-neutron-induced recoil and alpha particle tracks in polycarbonate films may be enlarged for direct visual observation and automated counting procedures employing electrochemical etching techniques. Electrochemical etching is, for example, carried out in a 28% KOH solution at room temperature by applying a 2000 V peak-to-peak voltage at 1 kHz frequency. Such recoil particle amplification can be used for the detection of wide neutron dose ranges from 1 mrad. to 1000 rads. or higher, if desired.

Detection of urinary biomarkers for early diagnosis of acute renal allograft rejection by proteomic analysis.

PubMed

Jia, Xiongfei; Gan, Chengjun; Xiao, Ke; He, Weifeng; Zhang, Tao; Huang, Cibing; Wu, Xiongfei; Luo, Gaoxing; Wang, Xiaojuan; Hu, Jie; Tan, Jiangling; Zhang, Xiaorong; Larsen, Peter Mose; Wu, Jun

2009-06-01

Acute allograft rejection has been recognized as a major impediment to improved success in renal transplantation. Timely detection and control of rejection are very important for the improvement in long-term renal allograft survival. Thus, biomarkers for early diagnosis of acute rejection are required urgently to clinical medication. This study seeks to search for such biomarker candidates by comparing patients' pre-treatment urinary protein profiling with their post-treatment urinary protein profiling. A total of 15 significantly and consistently down-regulated protein candidates were identified. Among them, alpha-1-antichymotrypsin precursor (AACT), tumor rejection antigen gp96 (GP96) and Zn-Alpha-2-Glycoprotein (ZAG) were selected for further analysis. The results indicated that Western Blot assay of AACT, GP96 and ZAG had advanced the diagnosis time of acute renal rejection by 3 days, compared with current standard clinical observation and laboratory examination. Furthermore, the double-blind detection revealed that the accuracy, sensitivity and specificity of the diagnosis of acute renal rejection of AACT, GP96 and ZAG were 66.67%/100%/60%, 83.33%/100%/80% and 66.67%/100%/60%, respectively, and 100%/100%/100% in combination. In conclusion, urinary protein AACT, GP96 and ZAG could be a set of potential biomarkers for early non-invasive diagnosis of the acute rejection after renal transplantation. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effective harmonic approach to helix proteins

NASA Astrophysics Data System (ADS)

Choi, Sung Nam Peter

Recent laser-induced experiments have shown that on the time scale of long range tertiary contact formation, the kinetics of the helix-coil interconversion are very rapid (1). The notion that secondary structures form first before long range tertiary contacts are made, suggests that the helix-coil interconversion is one key in understanding the protein folding problem. We developed a method of generating an alpha-helix conformation of any residue using AMBER 4.0, the Protein Data Bank (PDB), and a series of pattern matching translation and rotation operations. We have chosen to study Alanine for its highly non polar nature, and Glutamine for its highly polar characteristic. Using the information obtained from the above method, analysis of vibrational lattice dynamics are carried out on polymers Poly-alpha-L alanine (PLA) and Poly-alpha-L glutamic acid (PLGA). The lattice dynamics method called Modified Self- consistent Harmonic Approach theory (MSHA) was used in carrying out the analysis of the PLA and PLGA helix-coil transition. MSHA was originally developed for the DNA molecule by Prohofsky et al. In this model, the molecule is considered as a one dimensional, repeating unit cell of an infinite helix. The lattice was modeled with harmonic force constants. Anharmonicity of hydrogen bond force constants at different temperatures are introduced along with the effects of water on the polar PLGA and the non polar PLA. Using MSHA, we calculated the opening bond probabilities of PLGA at different temperatures. The experimentally observed helix to coil relaxation time τ* of PLGA was inversely compared to our results with a correlation coefficient of 0.8424 (5, 13, 58). These experiments were done at temperatures ranging from 295 K to 310 K. Our calculation also yielded critical melting temperatures of Tc=317 K for PLGA and Tc=347 K for PLA. The calculated acoustic compressional velocities were 4.78 km/s and 4.84 km/s for PLA and PLGA respectively. Our calculation clearly indicates that the MSHA methodology, along with the use of AMBER 4.0, yields a good physical model of helix to coil transition of proteins.

Measurement of the {sup 12}C({alpha},{gamma}){sup 16}O reaction at TRIAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makii, H.; Miyatake, H.; Wakabayashi, Y.

2012-11-12

We have measured the {gamma}-ray angular distribution of the {sup 12}C({alpha},{gamma}){sup 16}O reaction at TRIAC (Tokai Radioactive Ion Accelerator Complex) to accurately determine the E1 and E2 cross sections. In this experiment, we used high efficiency anti-Compton NaI(T1) spectrometers to detect a {gamma}-ray from the reaction with large S/N ratio, intense pulsed {alpha}-beams to discriminate true event from background events due to neutrons from {sup 13}C({alpha},n){sup 16}O reaction with a time-of-flight (TOF) method. We succeeded in removing a background events due to neutrons and clearly detected {gamma}-ray from the {sup 12}C({alpha}{gamma}){sup 16}O reaction with high statistics.

Ultrasensitive Label-free Electrochemical Immunosensor based on Multifunctionalized Graphene Nanocomposites for the Detection of Alpha Fetoprotein

PubMed Central

Wang, Yaoguang; Zhang, Yong; Wu, Dan; Ma, Hongmin; Pang, Xuehui; Fan, Dawei; Wei, Qin; Du, Bin

2017-01-01

In this work, a novel label-free electrochemical immunosensor was developed for the quantitative detection of alpha fetoprotein (AFP). Multifunctionalized graphene nanocomposites (TB-Au-Fe3O4-rGO) were applied to modify the electrode to achieve the amplification of electrochemical signal. TB-Au-Fe3O4-rGO includes the advantages of graphene, ferroferric oxide nanoparticles (Fe3O4 NPs), gold nanoparticles (Au NPs) and toluidine blue (TB). As a kind of redox probe, TB can produce the electrochemical signal. Graphene owns large specific surface area, high electrical conductivity and good adsorption property to load a large number of TB. Fe3O4 NPs have good electrocatalytic performance towards the redox of TB. Au NPs have good biocompatibility to capture the antibodies. Due to the good electrochemical performance of TB-Au-Fe3O4-rGO, the effective and sensitive detection of AFP was achieved by the designed electrochemical immunosensor. Under optimal conditions, the designed immunosensor exhibited a wide linear range from 1.0 × 10−5 ng/mL to 10.0 ng/mL with a low detection limit of 2.7 fg/mL for AFP. It also displayed good electrochemical performance including good reproducibility, selectivity and stability, which would provide potential applications in the clinical diagnosis of other tumor markers. PMID:28186128

Phase diagram of the quantum Ising model with long-range interactions on an infinite-cylinder triangular lattice

NASA Astrophysics Data System (ADS)

Saadatmand, S. N.; Bartlett, S. D.; McCulloch, I. P.

2018-04-01

Obtaining quantitative ground-state behavior for geometrically-frustrated quantum magnets with long-range interactions is challenging for numerical methods. Here, we demonstrate that the ground states of these systems on two-dimensional lattices can be efficiently obtained using state-of-the-art translation-invariant variants of matrix product states and density-matrix renormalization-group algorithms. We use these methods to calculate the fully-quantitative ground-state phase diagram of the long-range interacting triangular Ising model with a transverse field on six-leg infinite-length cylinders and scrutinize the properties of the detected phases. We compare these results with those of the corresponding nearest neighbor model. Our results suggest that, for such long-range Hamiltonians, the long-range quantum fluctuations always lead to long-range correlations, where correlators exhibit power-law decays instead of the conventional exponential drops observed for short-range correlated gapped phases. Our results are relevant for comparisons with recent ion-trap quantum simulator experiments that demonstrate highly-controllable long-range spin couplings for several hundred ions.

Detection of low-level environmental chemical allergy by a long-term sensitization method.

PubMed

Fukuyama, Tomoki; Ueda, Hideo; Hayashi, Koichi; Tajima, Yukari; Shuto, Yasufumi; Saito, Toru R; Harada, Takanori; Kosaka, Tadashi

2008-07-30

Multiple chemical sensitivity (MCS) is characterized by various signs, including neurological disorders and allergy. Exposure may occur through a major event, such as a chemical spill, or from long-term contact with chemicals at low levels. We are interested in the allergenicity of MCS and the detection of low-level chemical-related hypersensitivity. We used long-term sensitization followed by low-dose challenge to evaluate sensitization by well-known Th2 type sensitizers (trimellitic anhydride (TMA) and toluene diisocyanate (TDI)) and a Th1 type sensitizer (2,4-dinitrochlorobenzene (DNCB)). After topically sensitizing BALB/c mice (9 times in 3 weeks) and challenging them with TMA, TDI or DNCB, we assayed their auricular lymph nodes (LNs) for number of lymphocytes, surface antigen expression of B cells, and local cytokine production, and measured antigen-specific serum IgE levels. TMA and TDI induced marked increases in levels of antigen-specific serum IgE and of Th2 cytokines (IL-4, IL-5, IL-10, and IL-13) produced by ex vivo restimulated lymph node cells. DNCB induced a marked increase in Th1 cytokine (IL-2, IFN-gamma, and TNF-alpha) levels, but antigen-specific serum IgE levels were not elevated. All chemicals induced significant increases in number of lymphocytes and surface antigen expression of B cells. Our mouse model enabled the identification and characterization of chemical-related allergic reactions at low levels. This long-term sensitization method would be useful for detecting environmental chemical-related hypersensitivity.

pH regulation of mitochondrial branch chain alpha-keto acid transport and oxidation in rat heart mitochondria.

PubMed

Hutson, S M

1987-07-15

The kinetics of branched chain alpha-keto acid uptake and efflux were studied as a function of varied external and matrix pH. Matrix pH was determined by the distribution of 5,5'-dimethyloxazolidine-2,4-dione. When rat heart mitochondria were incubated under transport conditions at pH 7.0 with succinate as respiratory substrate, the matrix pH was significantly greater than 8.0. Matrix pH remained greater than or equal to 8.0 when the medium pH was varied from 6.3 to 8.3, and it was lowered below 8.0 by addition of 5 mM phosphate or uncoupler. No pH gradient was detectable when mitochondria were incubated in the presence of valinomycin and uncoupler. Efflux of alpha-ketoisocaproate or alpha-ketoisovalerate from rat heart mitochondria obeyed first order kinetics. Varying the external pH from 6.6 to 8.3 had no significant effect on efflux, and at an external pH of 7.0, the first order rate constant for efflux was not affected by decreasing the matrix pH. On the other hand, exchange was sensitive to changes in medium but not matrix pH. The K0.5 for external branched chain alpha-keto acid was lowered by changing the medium pH from 7.6 to 6.3. At medium pH values greater than or equal to 8.0 both K0.5 and Vmax were affected. Uptake was determined either by measuring initial rates or was calculated after measuring the first order approach to a final equilibrium value. Unlike efflux, uptake was sensitive to changes in both external and matrix pH. The rate of branched chain alpha-keto acid uptake was stimulated by decreasing the medium pH from 8.3 to 6.3 and by alkalinization of the mitochondrial matrix. The estimated external pK for proton binding was 6.9. The data indicate that the branched chain alpha-keto acid transporter is asymmetric, that is, binding sites for substrate on the inside and outside of the mitochondrial membrane are not identical. alpha-Ketoisocaproate oxidation was measured at 37 degrees C in isolated mitochondria over the pH range of 6.6 to 8.1. Changes in the rate of branched chain alpha-keto acid oxidation, particularly when ATP was added (increase delta pH), were found to parallel the pH effects observed on branched chain alpha-keto acid uptake. Therefore, transport, and by implication oxidation, can be regulated by pH changes within the physiological range. Furthermore, intracellular pH may affect the degree of compartmentation between the cytosolic and mitochondrial branched chain alpha-keto acid pools.

Label-free electrochemical aptasensor for detection of alpha-fetoprotein based on AFP-aptamer and thionin/reduced graphene oxide/gold nanoparticles.

PubMed

Li, Guiyin; Li, Shanshan; Wang, Zhihong; Xue, Yewei; Dong, Chenyang; Zeng, Junxiang; Huang, Yong; Liang, Jintao; Zhou, Zhide

2018-04-15

Sensitive and accurate detection of tumor markers is critical to early diagnosis, point-of-care and portable medical supervision. Alpha fetoprotein (AFP) is an important clinical tumor marker for hepatocellular carcinoma (HCC), and the concentration of AFP in human serum is related to the stage of HCC. In this paper, a label-free electrochemical aptasensor for AFP detection was fabricated using AFP-aptamer as the recognition molecule and thionin/reduced graphene oxide/gold nanoparticles (TH/RGO/Au NPs) as the sensor platform. With high electrocatalytic property and large specific surface area, RGO and Au NPs were employed on the screen-printed carbon electrode to load TH molecules. The TH not only acted as a bridging molecule to effectively capture and immobilize AFP-aptamer, but as the electron transfer mediator to provide the electrochemical signal. The AFP detection was based on the monitoring of the electrochemical current response change of TH by the differential pulse voltammetry. Under optimal conditions, the electrochemical responses were proportional to the AFP concentration in the range of 0.1-100.0 μg/mL. The limit of detection was 0.050 μg/mL at a signal-to-noise ratio of 3. The proposed method may provide a promising application of aptamer with the properties of facile procedure, low cost, high selectivity in clinic. Copyright © 2018. Published by Elsevier Inc.

Multiplexed detection of tumor markers with multicolor quantum dots based on fluorescence polarization immunoassay.

PubMed

Tian, Jianniao; Zhou, Liujin; Zhao, Yanchun; Wang, Yuan; Peng, Yan; Zhao, Shulin

2012-04-15

A multicolor quantum dot (QD)-based nanosensor for multiplex detection of two tumor markers in a homogeneous format based on fluorescence polarization immunoassay was proposed. QDs520 and QDs620 were labeled alpha-fetoprotein(α-AFP) and carcinoembryonic antigen (CEA), respectively. After separated and purified by ultrafiltration, they were used in fluorescence polarization immunoassay for the simultaneous detection of human serum alpha-fetoprotein and carcinoembryonic antigen. Under the optimal conditions, the multi-analyte immunosensor had a wide linear range (from 0.5 ng mL(-1) to 500 ng mL(-1)) for both two tumor markers and good correlation (0.996 for α-AFP and 0.993 for CEA). The detection limits (LOD) were 0.36 ng mL(-1) for CEA and 0.28 ng mL(-1) for α-AFP (S/N=3). The carcinoembryonic antigen and fetoprotein in clinical serum samples were simultaneously detected. The results from 28 serum samples had a good agreement with enzyme-linked immunosorbent assay (ELISA). The relative standard deviation and the recovery suggested that the precision and the accuracy of this analytical method were satisfactory. This strategy with high sensitivity, good specificity, easy procedures and short analysis time shows great promise for clinical diagnoses and basic discovery. The application of QDs with longer fluorescence lifetime and small fluorescence polarization can be used for the determination of high molecular-weight substances which cannot be analyzed using dye fluorescence polarization immunoassay. Copyright © 2012 Elsevier B.V. All rights reserved.

Segmentation of time series with long-range fractal correlations.

PubMed

Bernaola-Galván, P; Oliver, J L; Hackenberg, M; Coronado, A V; Ivanov, P Ch; Carpena, P

2012-06-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome.

Local Network-Level Integration Mediates Effects of Transcranial Alternating Current Stimulation.

PubMed

Fuscà, Marco; Ruhnau, Philipp; Neuling, Toralf; Weisz, Nathan

2018-05-01

Transcranial alternating current stimulation (tACS) has been proposed as a tool to draw causal inferences on the role of oscillatory activity in cognitive functioning and has the potential to induce long-term changes in cerebral networks. However, effectiveness of tACS underlies high variability and dependencies, which, as previous modeling works have suggested, may be mediated by local and network-level brain states. We used magnetoencephalography to record brain activity from 17 healthy participants at rest as they kept their eyes open (EO) or eyes closed (EC) while being stimulated with sham, weak, or strong alpha-tACS using a montage commonly assumed to target occipital areas. We reconstructed the activity of sources in all stimulation conditions by means of beamforming. The analysis of resting-state brain activity revealed an interaction of the external stimulation with the endogenous alpha power increase from EO to EC. This interaction was localized to the posterior cingulate, a region remote from occipital cortex. This suggests state-dependent (EO vs. EC) long-range effects of tACS. In a follow-up analysis of this online-tACS effect, we find evidence that this state-dependency effect is mediated by functional network changes: connection strength from the precuneus was significantly correlated with the state-dependency effect in the posterior cingulate during tACS. No analogous correlation could be found for alpha power modulations in occipital cortex. Altogether, this is the first strong evidence to illustrate how functional network architectures can shape tACS effects.

Alpha-helical hydrophobic polypeptides form proton-selective channels in lipid bilayers

NASA Technical Reports Server (NTRS)

Oliver, A. E.; Deamer, D. W.

1994-01-01

Proton translocation is important in membrane-mediated processes such as ATP-dependent proton pumps, ATP synthesis, bacteriorhodopsin, and cytochrome oxidase function. The fundamental mechanism, however, is poorly understood. To test the theoretical possibility that bundles of hydrophobic alpha-helices could provide a low energy pathway for ion translocation through the lipid bilayer, polyamino acids were incorporated into extruded liposomes and planar lipid membranes, and proton translocation was measured. Liposomes with incorporated long-chain poly-L-alanine or poly-L-leucine were found to have proton permeability coefficients 5 to 7 times greater than control liposomes, whereas short-chain polyamino acids had relatively little effect. Potassium permeability was not increased markedly by any of the polyamino acids tested. Analytical thin layer chromatography measurements of lipid content and a fluorescamine assay for amino acids showed that there were approximately 135 polyleucine or 65 polyalanine molecules associated with each liposome. Fourier transform infrared spectroscopy indicated that a major fraction of the long-chain hydrophobic peptides existed in an alpha-helical conformation. Single-channel recording in both 0.1 N HCl and 0.1 M KCl was also used to determine whether proton-conducting channels formed in planar lipid membranes (phosphatidylcholine/phosphatidylethanolamine, 1:1). Poly-L-leucine and poly-L-alanine in HCl caused a 10- to 30-fold increase in frequency of conductive events compared to that seen in KCl or by the other polyamino acids in either solution. This finding correlates well with the liposome observations in which these two polyamino acids caused the largest increase in membrane proton permeability but had little effect on potassium permeability. Poly-L-leucine was considerably more conductive than poly-L-alanine due primarily to larger event amplitudes and, to a lesser extent, a higher event frequency. Poly-L-leucine caused two populations of conductive events, one in the 0.1-0.5 pA range, and one in the 1.0-5.0 pA range, whereas nearly all events caused by poly-L-alanine were in the 0.1-0.5 pA range at an applied voltage of +60 mV. The channel-like activity appeared to switch between conductive and nonconductive states, with most open-times in the range of 50-200 ms. We conclude that hydrophobic polyamino acids produce proton-conducting defects in lipid bilayers that may be used to model functional proton channels in biological membranes.

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.; Li, Qian; Zhang, Yiwei

2015-03-01

We have recently found that a long length of fiber of up to 1 km terminated with an in-fiber cavity structure can detect vibrations over a frequency range from 5 Hz to 2 kHz. We want to determine whether the sensor (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to maintenance cost. The sensor may also help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that requires the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Acoustic vibration monitoring may need sensing at even higher frequencies (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large re-enforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed longgauge vibration sensor depends on packaging.

Preliminary results from the lunar prospector alpha particle spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawson, S. L.

2001-01-01

The Lunar Prospector Alpha Particle Spectrometer (LP APS) builds on Apollo heritage and maps the distribution of outgassing sites on the Moon. The APS searches for lunar surface gas release events and maps their distribution by detecting alpha particles produced by the decay of gaseous radon-222 (5.5 MeV, 3.8 day half-life) and solid polonium-210 (5.3 MeV, 138 day half-life, but remains on the surface with a 21 year half-life as lead-210), which are radioactive daughters from the decay of uranium-238. Radon is in such small quantities that it is not released directly from the lunar interior, rather it is entrainedmore » in a stream of gases and serves as a tracer for such gases. Once released, the radon spreads out by 'bouncing' across the surface on ballistic trajectories in a random-walk process. The 3.8 day half-life of radon-222 allows the gas to spread out by several 100 km before it decays and allows the APS to detect gas release events up to a few days after they occur. The long residence time (10s of years) of the lead-210 precursor to the polonium-210 allows the mapping of gas vents which have been active over the last approximately 50 years. Because radon and polonium are daughter products of the decay of uranium, the background level of alpha particle activity is a function of the lunar crustal uranium distribution. Using radioactive radon and polonium as tracers, the Apollo 15 and 16 Command Module orbital alpha particle experiments obtained evidence for the release of gases at several sites beneath the orbit tracks, especially over the Aristarchus Plateau and Mare Fecunditatis [1]. Aristarchus crater had previously been identified by ground-based observers as the site of transient optical events [2]. The Apollo 17 surface mass spectrometer showed that argon-40 is released from the lunar interior every few months, apparently in concert with some of the shallow moonquakes that are believed to be of tectonic origin [3]. The latter tectonic events could be associated with very young scarps identified in the lunar highlands [4] and are believed to indicate continued global contraction. Such quakes could open fissures leading to the release of gases that are trapped below the surface. The detection of radon-222 outgassing events at the margins of Fecunditatis basin was surprising because the observed surface distribution of uranium and thorium do not extend sufficiently eastward to cover Fecunditatis. If the Apollo detections prove sound, then those alpha particle emissions indicate substantial subsurface concentrations of uranium-238 within Fecunditatis. A primary goal of the APS was to map gas-release events, thus allowing both an appraisal of the current level of tectonic activity on the Moon and providing a probe of subsurface uranium concentrations.« less

[Alpha power voluntary increasing training for cognition enhancement study].

PubMed

Alekseeva, M V; Balioz, N V; Muravleva, K B; Sapina, E V; Bazanova, O M

2012-01-01

With the aim simultaneous alpha EEG stimulating and EMG decreasing biofeedback training impact on the alpha-activity and cognitive functions 27 healthy male subjects (18-34 years) were investigated in pre- and post 10 training sessions of the voluntary increasing alpha power in individual upper alpha range. The accuracy of conceptual span task, fluency and flexibility in alternatives use task performance and alpha-activity indices were compared in real (14 participants) and sham (13 participants) biofeedback groups for the discrimination of the feedback role in training. The follow up effect oftrainings was studied through month over the training sessions. Results showed that alpha biofeedback training enhanced the fluency and accuracy in cognitive performance, increased resting frequency, width and power in individual upper alpha range only in participants with low baseline alpha frequency. While mock biofeedback increased resting alpha power only in participants with high baseline resting alpha frequency and did not change the cognitive performance. Biofeedback training eliminated the alpha power decrease in response to arithmetic task in both with high and low alpha frequency participants and this effect was followed up over the month. Mock biofeedback training has no such effect. It could be concluded that alpha-EEG-EMG biofeedback has application not only for cognition enhancement, but also in prognostic aims in clinical practice and brain-computer interface technology.

Serum adipokines and HIV viral replication in patients undergoing antiretroviral therapy

PubMed Central

Aramă, Victoria; Tilişcan, Cătălin; Ion, Daniela Adriana; Mihăilescu, Raluca; Munteanu, Daniela; Streinu-Cercel, Anca; Tudor, Ana Maria; Hristea, Adriana; Leoveanu, Viorica; Olaru, Ioana; Aramă, Ştefan Sorin

2012-01-01

Introduction Several studies have reported that cytokines secreted by adipose tissue (adipokines) may be linked to HIV replication. The aim of the study was to evaluate the relationship between HIV replication and serum levels of adipokines, in a Caucasian HIV-infected population of men and women undergoing complex antiretroviral therapy. Methods A cross-sectional study was conducted in an unselected sample of 77 HIV-1-positive patients. Serum adipokines levels were measured including circulating adiponectin, leptin, resistin, tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6). Patients were divided into two groups: Group 1 - with undetectable viral load and Group 2 - with persistent HIV viral replication. Differences between groups ? were tested using independent-sample t-test for Gaussian variables and Mann–Whitney–Wilcoxon test for non-parametric variables. Pearson's chi-squared test was used for correlation analysis. Results A total of 77 patients (age range: 17-65, mean: 32.5 years) including 44 men (57.1% men, age range: 17–63 years, mean: 34.1 years) and 33 women (42.9% women age range: 19–65 years, mean: 30.3 years) were included in the study. TNF-alpha had significantly higher serum levels in patients with detectable viral load (16.89 vs. 9.35 pg/mL), (p=0.043), but correlation analysis lacked statistical significance. Adiponectin had median serum levels of 9.22 ìg/mL in Group 1 vs. 16.50 ìg/mL in Group 2 but the results lacked statistical significance (p=0.059). Higher leptin, IL-6 and resistin serum levels were noted in patients with undetectable HIV viral load, without statistical significance. Conclusions The present study reported higher TNF-alpha serum levels in patients with persistent HIV viral load. We found no statistically significant correlations between adiponectin, leptin, resistin and IL-6 and HIV viral load in our Caucasian HIV-positive study population, undergoing antiretroviral therapy. PMID:24432258

Energy-dependent etching-related impacts on CR-39 alpha detection efficiency for the Rn-222 and Rn-220 decay chains

NASA Astrophysics Data System (ADS)

Tan, Y.; Yuan, H.; Kearfott, K. J.

2018-04-01

CR-39 detectors are widely used to measure environmental levels of Rn-222, Rn-220 and their progeny. Prior research reported the CR-39 detection efficiency for alpha particles from Rn-222, Rn-220 and their progeny under a variety of etching conditions. This paper provides an explanation for interesting observations included in that work, namely that the critical incidence angle decreases with the increasing particle energy and the detection efficiency for 8.78 MeV alpha particles is zero. This paper explains these phenomena from a consideration of the interaction of alpha particles with the CR-39 detectors and the physics of etching dynamics. The proposed theory provides a rationale for an approach to optimizing the etching conditions of CR-39 detector for measuring Rn-222, Rn-220 and their progenies.

Glutathione regulation of redox-sensitive signals in tumor necrosis factor-{alpha}-induced vascular endothelial dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsou, T.-C.; Yeh, S.C.; Tsai, F.-Y.

2007-06-01

We investigated the regulatory role of glutathione in tumor necrosis factor-alpha (TNF-{alpha})-induced vascular endothelial dysfunction as evaluated by using vascular endothelial adhesion molecule expression and monocyte-endothelial monolayer binding. Since TNF-{alpha} induces various biological effects on vascular cells, TNF-{alpha} dosage could be a determinant factor directing vascular cells into different biological fates. Based on the adhesion molecule expression patterns responding to different TNF-{alpha} concentrations, we adopted the lower TNF-{alpha} (0.2 ng/ml) to rule out the possible involvement of other TNF-{alpha}-induced biological effects. Inhibition of glutathione synthesis by L-buthionine-(S,R)-sulfoximine (BSO) resulted in down-regulations of the TNF-{alpha}-induced adhesion molecule expression and monocyte-endothelial monolayermore » binding. BSO attenuated the TNF-{alpha}-induced nuclear factor-kappaB (NF-{kappa}B) activation, however, with no detectable effect on AP-1 and its related mitogen-activated protein kinases (MAPKs). Deletion of an AP-1 binding site in intercellular adhesion molecule-1 (ICAM-1) promoter totally abolished its constitutive promoter activity and its responsiveness to TNF-{alpha}. Inhibition of ERK, JNK, or NF-{kappa}B attenuates TNF-{alpha}-induced ICAM-1 promoter activation and monocyte-endothelial monolayer binding. Our study indicates that TNF-{alpha} induces adhesion molecule expression and monocyte-endothelial monolayer binding mainly via activation of NF-{kappa}B in a glutathione-sensitive manner. We also demonstrated that intracellular glutathione does not modulate the activation of MAPKs and/or their downstream AP-1 induced by lower TNF-{alpha}. Although AP-1 activation by the lower TNF-{alpha} was not detected in our systems, we could not rule out the possible involvement of transiently activated MAPKs/AP-1 in the regulation of TNF-{alpha}-induced adhesion molecule expression.« less

[Prevalence survey and molecular characterization of alpha and beta thalassemia in Liuzhou city of Guangxi].

PubMed

Cai, Ren; Li, Liyan; Liang, Xin; Liu, Zhongying; Su, Liu; Li, Wenjun; Zhu, Qiangui; Mo, Qiuhua; Pan, Lizhen; Ouyang, Hong; Huang, Lihua; Xu, Xiangmin

2002-08-01

To investigate the gene frequencies and mutation patterns of alpha thalassemia (alpha-thal) and beta thalassemia (beta-thal) in Liuzhou city of Guangxi Zhuang Autonomous Region. Cluster sampling was used. A total of 1 028 of umbilical blood samples were collected for a prevalence study of alpha-thal and a total of 1 312 healthy young people when receiving pre-marriage consultation were recruited for a beta-thal prevalence survey. Individuals live in city or town area of Liuzhou. A complete blood count as well as hemoglobin electrophoresis analysis were done in all of samples for phenotyping of alpha and beta-thals. Those with Hb Bart's for alpha-thal indicator and those with both microcytosis (MCV < 85 fl) and elevated levels of Hb A(2) (>/=4.0%) for beta-thal were further studied by DNA analysis. PCR-based methodologies were used to characterize the mutation contributions of alpha and beta-thals. All the subjects were tested for the state of carrying beta-thala alleles for evaluating the situation of the compound heterozygotes of alpha-thal with beta-thal. Of 1 028 random samples of umbilical blood screened, 112 of subjects were defined to be the gene carriers of alpha-thal. The alpha-thal carrier rate was as high as 11.19% including 3 compound heterozygotes. Five well-known types of alpha-thal alleles were detected with gene contributions of 37.4% (--(SEA) deletion), 31.3% (-alpha(3.7) deletion), 17.4% (-alpha(4.2) deletion), 12.1% (alpha(CS)alpha mutation), and 0.9% (alpha(QS)alpha mutation), successively. Of the 1 312 adult specimens studied, 89 with beta-thal including 14 of the compound higher Hb F subjects were detected. All of the 89 phenotypic beta-thal carriers had the mutations in the beta-globin gene, making the overall prevalence 6.78%. The commonly seen three mutations, beta CD41 - 42 (-CTTT) frameshift, beta CD17 (T-A) nonsense mutation and beta-28 (A-G) promoter variation were accounted for 90% of the beta-thal alleles in Liuzhou. Of these beta-thal subjects, 16 (accounting for 18%) were found to be the compound heterozygosity for a beta-thal and an alpha-thal with 9 different types of gene defects with a detection rate 1.22%. Data from ecidation of alpha and beta-thal gene frequencies and mutation spectrum in Liuzhou city was useful for genetic counselling and prenatal diagnosis of this disease.

Treatment of solid tumors by interstitial release of recoiling short-lived alpha emitters

NASA Astrophysics Data System (ADS)

Arazi, L.; Cooks, T.; Schmidt, M.; Keisari, Y.; Kelson, I.

2007-08-01

A new method utilizing alpha particles to treat solid tumors is presented. Tumors are treated with interstitial radioactive sources which continually release short-lived alpha emitting atoms from their surface. The atoms disperse inside the tumor, delivering a high dose through their alpha decays. We implement this scheme using thin wire sources impregnated with 224Ra, which release by recoil 220Rn, 216Po and 212Pb atoms. This work aims to demonstrate the feasibility of our method by measuring the activity patterns of the released radionuclides in experimental tumors. Sources carrying 224Ra activities in the range 10-130 kBq were used in experiments on murine squamous cell carcinoma tumors. These included gamma spectroscopy of the dissected tumors and major organs, Fuji-plate autoradiography of histological tumor sections and tissue damage detection by Hematoxylin-Eosin staining. The measurements focused on 212Pb and 212Bi. The 220Rn/216Po distribution was treated theoretically using a simple diffusion model. A simplified scheme was used to convert measured 212Pb activities to absorbed dose estimates. Both physical and histological measurements confirmed the formation of a 5-7 mm diameter necrotic region receiving a therapeutic alpha-particle dose around the source. The necrotic regions shape closely corresponded to the measured activity patterns. 212Pb was found to leave the tumor through the blood at a rate which decreased with tumor mass. Our results suggest that the proposed method, termed DART (diffusing alpha-emitters radiation therapy), may potentially be useful for the treatment of human patients.

Genotyping of alpha-thalassemia deletions using multiplex polymerase chain reactions and gold nanoparticle-filled capillary electrophoresis.

PubMed

Chen, Yen-Ling; Shih, Chi-Jen; Ferrance, Jerome; Chang, Ya-Sian; Chang, Jan-Gowth; Wu, Shou-Mei

2009-02-13

A gold nanoparticle-filled capillary electrophoresis method combined with three multiplex polymerase chain reactions (PCRs) was established for simultaneous diagnosis of five common alpha-thalassemia deletions, including the -alpha(3.7) deletion, -alpha(4.2) deletion, Southeast Asian (--(SEA)), Filipino (--(FIL)) and Thai (--(THAI)) deletions. Gold nanoparticles (GNPs) were used as a pseudostationary phase to improve the resolution between DNA fragments in a low-viscosity polymer. To achieve the best CE separation, several parameters were evaluated for optimizing the separation conditions, including the capillary coating, the concentrations of polymer sieving matrix, the sizes and concentrations of GNPs, the buffer concentrations, and the pH. The final CE method for separating a 200-base pair (bp) DNA ladder and alpha-thalassemia deletions used a DB-17 capillary, 0.6% poly(ethylene oxide) (PEO) prepared in a mixture of GNP(32nm) solution and glycine buffer (25mM, pH 9.0) (80:20, v/v) as the sieving matrix with 1microM YO-PRO-1 for fluorescence detection; the applied voltage was -10kV (detector at anode side) and the separation temperature was 25 degrees C. Under these optimal conditions, 15 DNA fragments with sizes ranging from 0.2kb to 3.0kb were resolved within 11.5min. The RSDs of migration times were less than 2.81%. A total of 21 patients with alpha-thalassemia deletions were analyzed using this method, and all results showed good agreement with those obtained by gel electrophoresis.

Neutron flux measurements using scintillator-photodiode-preamplifier system and new types of scintillators

NASA Astrophysics Data System (ADS)

Ryzhikov, Vladimir D.; Burachas, S. F.; Volkov, V. G.; Danshin, Evgeniy A.; Lisetskaya, Elena K.; Piven, L. A.; Svishch, Vladimir M.; Chernikov, Vyacheslav V.; Filimonov, A. E.

1997-02-01

After the Chernobyl catastrophe among the problems of current concern a question arose of detection of 'hot' particles formed from plutonium alloys with carbon, nitrogen, silicon, etc. For this purpose, the instruments are needed, which would be able to detect not only alpha- particles and low energy gamma-radiation, but also neutrons and high energy gamma-quanta from ((alpha) , n(gamma) ) - reactions. At present for each kind of radiation detectors of different types are used. A general drawback of all these instruments is their narrow dynamic range of dose rates and energies, and especially impossibility to registrate n-flux in condition large background activity gamma-rays nuclei, which makes each of them applicable only under certain specific conditions. For detection of 'hot' particles, oxide and semiconductor scintillators were used, which contained elements with large capture cross section for thermal neutrons. In this paper we try to determine possibilities and limitations of solid-state neutron detectors based on CdS(Te), ZnSe(Te), CdWO4 (CWO), Gd2SiO5 (GSO) scintillators developed and produced by the Science and Technology Center for Radiation Instruments of the Institute for Single Crystals. The instruments developed by Center are based preferable on a very promising system 'scintillator- photodiode-preamplifier' matched with modern computer data processing techniques.

Cow's milk proteins in human milk.

PubMed

Coscia, A; Orrù, S; Di Nicola, P; Giuliani, F; Rovelli, I; Peila, C; Martano, C; Chiale, F; Bertino, E

2012-01-01

Cow's milk proteins (CMPs) are among the best characterized food allergens. Cow's milk contains more than twenty five different proteins, but only whey proteins alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin (BSA), and lactoferrin, as well as the four caseins, have been identified as allergens. Aim of this study was to investigate by proteomics techniques cow's milk allergens in human colostrum of term and preterm newborns' mothers, not previously detected, in order to understand if such allergens could be cause of sensitization during lactation. Term colostrum samples from 62 healthy mothers and preterm colostrum samples from 11 healthy mothers were collected for this purpose. The most relevant finding was the detection of the intact bovine alpha-S1-casein in both term and preterm colostrum. Using this method, which allows direct proteins identification, beta-lactoglobulin was not detected in any of colostrum samples. According to our results bovine alpha 1 casein that is considered a major cow's milk allergen is readily secreted in human milk: further investigations are needed in order to clarify if alpha-1-casein has a major role in sensitization or tolerance to cow's milk of exclusively breastfed predisposed infants.

Detection of H-alpha emission in the hot white dwarf G191-B2B

NASA Astrophysics Data System (ADS)

Reid, Neill; Wegner, Gary

1988-12-01

High-resolution spectra of G191-B2B, the hottest known DA white dwarf were obtained which reveal emission in the core of the H-alpha line. The observations show little variation in the line profile over a period of four days, ruling out line-doubling in a close binary as an explanation. The observed emission cannot be due to a nearby red dwarf companion, while the absence of any spatially extended emission argues against either a planetary nebula remnant or local ionization of the interstellar medium. The determination of the systemic velocity, using the companion red dwarf G191-B2A, is 5 + or - 2 km/s and shows that both the H-alpha emission and the high-excitation species observed in the ultraviolet are redshifted by 19 + or - 3 km/s, suggesting a photospheric origin. The low redshift implies a mass of 0.45 solar mass for this hot white dwarf, although the uncertainties in the effective temperature and parallax permit masses in the range 0.29 to 0.60 solar mass.

Gold nanoparticles and polyethylene glycols functionalized conducting polyaniline nanowires for ultrasensitive and low fouling immunosensing of alpha-fetoprotein.

PubMed

Hui, Ni; Sun, Xiaotian; Song, Zhiling; Niu, Shuyan; Luo, Xiliang

2016-12-15

An ultrasensitive biosensor for alpha-fetoprotein was developed based on electrochemically synthesized polyaniline (PANI) nanowires, which were functionalized with gold nanoparticles (AuNPs) and polyethylene glycols (PEG). The prepared PEG/AuNPs/PANI composite, combining the electrical conductivity of the AuNPs/PANI with the robust antifouling ability of PEG, offered an ideal substrate for the development of low fouling electrochemical biosensors. Alpha-fetoprotein (AFP), a well-known hepatocellular carcinoma biomarker, was used as a model analyte, and its antibody was immobilized on the PEG/AuNPs/PANI for the construction of the AFP immunosensor. Using the redox current of PANI as the sensing signal, in addition to the good biocompatibility of PEG/AuNPs and the anti-biofouling property of PEG, the developed immunosensor showed improved biosensing performances, such as wide linear range and ultralow detection limit (0.007pgmL(-1)). More importantly, it is label-free, reagentless and low fouling, making it capable of assaying AFP in real serum samples without suffering from significant interference or biofouling. Copyright © 2016 Elsevier B.V. All rights reserved.

Ultra-broadband phase-sensitive optical time-domain reflectometry with a temporally sequenced multi-frequency source.

PubMed

Wang, Zhaoyong; Pan, Zhengqing; Fang, Zujie; Ye, Qing; Lu, Bin; Cai, Haiwen; Qu, Ronghui

2015-11-15

A phase-sensitive optical time-domain reflectometry (Φ-OTDR) with a temporally sequenced multi-frequency (TSMF) source is proposed. This technique can improve the system detection bandwidth without the sensing range decreasing. Up to 0.5 MHz detection bandwidth over 9.6 km is experimentally demonstrated as an example. To the best of our knowledge, this is the first time that such a high detection bandwidth over such a long sensing range is reported in Φ-OTDR-based distributed vibration sensing. The technical issues of TSMF Φ-OTDR are discussed in this Letter. This technique will help Φ-OTDR find new important foreground in long-haul distributed broadband-detection applications, such as structural-health monitoring and partial-discharge online monitoring of high voltage power cables.

3D imaging of neutron tracks using confocal microscopy

NASA Astrophysics Data System (ADS)

Gillmore, Gavin; Wertheim, David; Flowers, Alan

2016-04-01

Neutron detection and neutron flux assessment are important aspects in monitoring nuclear energy production. Neutron flux measurements can also provide information on potential biological damage from exposure. In addition to the applications for neutron measurement in nuclear energy, neutron detection has been proposed as a method of enhancing neutrino detectors and cosmic ray flux has also been assessed using ground-level neutron detectors. Solid State Nuclear Track Detectors (or SSNTDs) have been used extensively to examine cosmic rays, long-lived radioactive elements, radon concentrations in buildings and the age of geological samples. Passive SSNTDs consisting of a CR-39 plastic are commonly used to measure radon because they respond to incident charged particles such as alpha particles from radon gas in air. They have a large dynamic range and a linear flux response. We have previously applied confocal microscopy to obtain 3D images of alpha particle tracks in SSNTDs from radon track monitoring (1). As a charged particle traverses through the polymer it creates an ionisation trail along its path. The trail or track is normally enhanced by chemical etching to better expose radiation damage, as the damaged area is more sensitive to the etchant than the bulk material. Particle tracks in CR-39 are usually assessed using 2D optical microscopy. In this study 6 detectors were examined using an Olympus OLS4100 LEXT 3D laser scanning confocal microscope (Olympus Corporation, Japan). The detectors had been etched for 2 hours 50 minutes at 85 °C in 6.25M NaOH. Post etch the plastics had been treated with a 10 minute immersion in a 2% acetic acid stop bath, followed by rinsing in deionised water. The detectors examined had been irradiated with a 2mSv neutron dose from an Am(Be) neutron source (producing roughly 20 tracks per mm2). We were able to successfully acquire 3D images of neutron tracks in the detectors studied. The range of track diameter observed was between 4 and 10 microns. Thus this study suggests that, using confocal microscopy, 3D imaging of neutron tracks in SSNTDs is feasible. (1) Wertheim D, Gillmore G, Brown L, Petford N. A new method of imaging particle tracks in solid state nuclear track detectors. J Microsc. 2010; 237: 1-6.

Assessment of the severity of dementia: validity and reliability of the Chinese (Cantonese) version of the Hierarchic Dementia Scale (CV-HDS).

PubMed

Poon, Vickie Wan-kei; Lam, Linda Chiu-wa; Wong, Samuel Yeung-shan

2008-09-01

With the rapid growth of the older population, early detection of cognitive deficits is crucial in slowing down functional deterioration of the elderly persons. To examine the validity and reliability of the Chinese (Cantonese) version of the Hierarchic Dementia Scale (CV-HDS) for Chinese older persons in Hong Kong. The HDS was translated into Cantonese Chinese. The content and cultural validity were evaluated by six expert panel members. Sixty-two participants with diagnosis of dementia were recruited for evaluation. Inter-rater reliability, test-retest reliability, internal consistency and concurrent validity were examined. The CV-HDS demonstrated satisfactory psychometric properties. inter-rater reliability and test-retest reliability were high (alpha=0.89 and alpha=0.94 respectively). High value of Cronbach's alpha (alpha=0.94) demonstrated good internal consistency. The concurrent validity of CV-HDS, through correlation with its scores with that of the Chinese version of Mini Mental Status Examination, was established (ranged from r=0.58 to r=0.78, p<0.01). The CV-HDS is a reliable and valid instrument for assessing severity of cognitive impairment in Cantonese speaking Chinese people with dementia. It facilitates treatment planning to optimize the effects of functional training and rehabilitation.

Single-molecule study of thymidine glycol and i-motif through the alpha-hemolysin ion channel

NASA Astrophysics Data System (ADS)

He, Lidong

Nanopore-based devices have emerged as a single-molecule detection and analysis tool for a wide range of applications. Through electrophoretically driving DNA molecules across a nanosized pore, a lot of information can be received, including unfolding kinetics and DNA-protein interactions. This single-molecule method has the potential to sequence kilobase length DNA polymers without amplification or labeling, approaching "the third generation" genome sequencing for around $1000 within 24 hours. alpha-Hemolysin biological nanopores have the advantages of excellent stability, low-noise level, and precise site-directed mutagenesis for engineering this protein nanopore. The first work presented in this thesis established the current signal of the thymidine glycol lesion in DNA oligomers through an immobilization experiment. The thymidine glycol enantiomers were differentiated from each other by different current blockage levels. Also, the effect of bulky hydrophobic adducts to the current blockage was investigated. Secondly, the alpha-hemolysin nanopore was used to study the human telomere i-motif and RET oncogene i-motif at a single-molecule level. In Chapter 3, it was demonstrated that the alpha-hemolysin nanopore can differentiate an i-motif form and single-strand DNA form at different pH values based on the same sequence. In addition, it shows potential to differentiate the folding topologies generated from the same DNA sequence.

Images in the rocket ultraviolet - Young clusters in H II regions of M83

NASA Technical Reports Server (NTRS)

Bohlin, Ralph C.; Cornett, Robert H.; Hill, Jesse K.; Stecher, Theodore P.

1990-01-01

UV images of M83 at 1540 and 2360 A reveal 18 compact sources that are associated with H II regions. E(B - V) values were estimated individually from the observed UV and optical colors and the Galactic UV extinction curve, using theoretical flux distributions. The dereddened colors are consistent with ages up to 3 x 10 to the 6th yr. A maximum possible age of 6.5 x 10 to the 6th yr is obtained assuming foreground reddening only. The distribution of observed colors is consistent with the Galactic reddening curve but not with enhanced far-UV extinction, as in the LMC 30 Dor curve. The H-alpha fluxes suggest either that dust within the H II regions absorbs up to 70 percent of the Lyman continuum radiation or that a similar fraction of the H-alpha flux is below the surface brightness detection limit. Cluster mass estimates depend on the range of stellar masses present but are probably in the range 10,000-100,000 solar masses.

Simultaneous determination of carbohydrates and simmondsins in jojoba seed meal (Simmondsia chinensis) by gas chromatography.

PubMed

Lein, Sabine; Van Boven, Maurits; Holser, Ron; Decuypere, Eddy; Flo, Gerda; Lievens, Sylvia; Cokelaere, Marnix

2002-11-22

Separate methods for the analyses of soluble carbohydrates in different plants and simmondsins in jojoba seed meal are described. A reliable gas chromatographic procedure for the simultaneous quantification of D-pinitol, myo-inositoL sucrose, 5-alpha-D-galactopyranosyl-D-pinitol. 2-alpha-D-galactopyranosyl-D-pinitol, simmondsin, 4-demethylsimmondsin, 5-demethylsimmondsin and 4,5-didemethylsimmondsin as trimethylsilyl derivatives in jojoba seed meal has been developed. The study of different extraction mixtures allowed for the quantitative recovery of the 9 analytes by a mixture of methanol-water (80:20, v/v) in the concentration range between 0.1 and 4%. Comparison of the separation parameters on three different capillary stationary phases with MS detection allowed for the choice of the optimal gas chromatographic conditions for baseline separation of the analytes.

Rotational Periods and Starspot Activity of Young Solar-Type Dwarfs in the Open Cluster IC 4665

NASA Technical Reports Server (NTRS)

Allain, S.; Bouvier, J.; Prosser, C.; Marschall, L. A.; Laaksonen, B. D.

1995-01-01

We present the results of a V-band photometric monitoring survey of 15 late-type dwarfs in the young open cluster IC 4665. Low-amplitude periodic light variations are found for 8 stars and ascribed to the modulation by starspots that cover typically a few percent of the stellar disk. Periods range from 0.6 to 3.7 d, translating to equatorial velocities between 13 and 93 km/s. That no period longer than 4 d was detected suggests a relative paucity of extremely slow rotators (V(sub eq) much less than 10 km/s) among late-type dwarfs in IC 4665. The fractional number of slow rotators in IC 4665 is similar to that of Alpha Per cluster, suggesting that IC 4665 is close in age to Alpha Per (approx. 50 Myr).

Enzyme replacement therapy with velmanase alfa (human recombinant alpha-mannosidase): Novel global treatment response model and outcomes in patients with alpha-mannosidosis.

PubMed

Harmatz, Paul; Cattaneo, Federica; Ardigò, Diego; Geraci, Silvia; Hennermann, Julia B; Guffon, Nathalie; Lund, Allan; Hendriksz, Christian J; Borgwardt, Line

2018-06-01

Alpha-mannosidosis is an ultra-rare monogenic disorder resulting from a deficiency in the lysosomal enzyme alpha-mannosidase, with a prevalence estimated to be as low as 1:1,000,000 live births. The resulting accumulation of mannose-rich oligosaccharides in all tissues leads to a very heterogeneous disorder with a continuum of clinical manifestations with no distinctive phenotypes. Long-term enzyme replacement therapy (ERT) with velmanase alfa is approved in Europe for the treatment of non-neurological manifestations in patients with mild to moderate alpha-mannosidosis. The clinical heterogeneity and rarity of the disease limit the sensitivity of single parameters to detect clinically relevant treatment effects. Thus, we propose a novel multiple variable responder analysis to evaluate the efficacy of ERT for alpha-mannosidosis and present efficacy analyses for velmanase alfa using this method. Global treatment response to velmanase alfa (defined by response to ≥2 domains comprising pharmacodynamic, functional, and quality of life outcomes) was applied post hoc to data from the pivotal placebo-controlled rhLAMAN-05 study and to the longer-term integrated data from all patients in the clinical development program (rhLAMAN-10). After 12 months of treatment, a global treatment response was achieved by 87% of patients receiving velmanase alfa (n = 15) compared with 30% of patients receiving placebo (n = 10). Longer-term data from all patients in the clinical program (n = 33) showed 88% of patients were global responders, including all (100%) pediatric patients (n = 19) and the majority (71%) of adult patients (n = 14). The responder analysis model demonstrates a clinically meaningful treatment effect with velmanase alfa and supports the early initiation and continued benefit of longer-term treatment of all patients with alpha-mannosidosis with this ERT. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Ship Detection in SAR Image Based on the Alpha-stable Distribution

PubMed Central

Wang, Changcheng; Liao, Mingsheng; Li, Xiaofeng

2008-01-01

This paper describes an improved Constant False Alarm Rate (CFAR) ship detection algorithm in spaceborne synthetic aperture radar (SAR) image based on Alpha-stable distribution model. Typically, the CFAR algorithm uses the Gaussian distribution model to describe statistical characteristics of a SAR image background clutter. However, the Gaussian distribution is only valid for multilook SAR images when several radar looks are averaged. As sea clutter in SAR images shows spiky or heavy-tailed characteristics, the Gaussian distribution often fails to describe background sea clutter. In this study, we replace the Gaussian distribution with the Alpha-stable distribution, which is widely used in impulsive or spiky signal processing, to describe the background sea clutter in SAR images. In our proposed algorithm, an initial step for detecting possible ship targets is employed. Then, similar to the typical two-parameter CFAR algorithm, a local process is applied to the pixel identified as possible target. A RADARSAT-1 image is used to validate this Alpha-stable distribution based algorithm. Meanwhile, known ship location data during the time of RADARSAT-1 SAR image acquisition is used to validate ship detection results. Validation results show improvements of the new CFAR algorithm based on the Alpha-stable distribution over the CFAR algorithm based on the Gaussian distribution. PMID:27873794

A defective retroviral vector encoding human interferon-alpha2 can transduce human leukemic cell lines.

PubMed

Austruy, E; Bagnis, C; Carbuccia, N; Maroc, C; Birg, F; Dubreuil, P; Mannoni, P; Chabannon, C

1998-01-01

Using the LXSN backbone, a defective retroviral vector (LISN) was constructed that encodes the human interferon (IFN)-alpha2 (hIFN-alpha2) gene and the neomycin resistance gene; the hIFN-alpha2 gene was cloned from human placental genomic DNA. High titers of the LISN retrovirus were produced by the amphotropic packaging cell line GP+envAM12. LISN is able to infect three human hematopoietic and leukemic cell lines: K562, LAMA-84, and TF-1. G418-resistant cells were detected in a similar proportion after infection with either the LISN retroviral vector or the LnLSN retroviral vector (encoding the nlsLacZ gene instead of hIFN-alpha2), suggesting that hIFN-alpha2 does not inhibit (or only partially inhibits) the production of retroviral particles by the packaging cell line and the infection of human cells. LISN-infected cells express and secrete hIFN-alpha2 as demonstrated by Northern blot analysis of poly(A)+ RNA, detection of the intracellular protein by fluorescence-activated cell sorter analysis, and detection of secreted hIFN-alpha in cell supernatants using an enzyme-linked immunosorbent assay. Retrovirally produced hIFN-alpha2 is biologically active, as demonstrated by the partial inhibition of the growth of K562 and TF-1, the modulation of the expression of cell surface antigens, the induction of the (2'-5') oligoadenylate synthetase, and, for LAMA-84, the down-modulation of the BCR-ABL protein. We conclude that the infection of human leukemic cell lines with a retroviral vector encoding hIFN-alpha2 is feasible and induces the expected biological effects. This experimental model will be useful in investigating the possibility of transducing normal and leukemic cells and hematopoietic progenitors and in determining the consequences of the autocrine production of hIFN-alpha2 on the behavior of these cells.

Establishment of sandwich ELISA for soluble alpha-Klotho measurement: Age-dependent change of soluble alpha-Klotho levels in healthy subjects.

PubMed

Yamazaki, Yuji; Imura, Akihiro; Urakawa, Itaru; Shimada, Takashi; Murakami, Junko; Aono, Yukiko; Hasegawa, Hisashi; Yamashita, Takeyoshi; Nakatani, Kimihiko; Saito, Yoshihiko; Okamoto, Nozomi; Kurumatani, Norio; Namba, Noriyuki; Kitaoka, Taichi; Ozono, Keiichi; Sakai, Tomoyuki; Hataya, Hiroshi; Ichikawa, Shoji; Imel, Erik A; Econs, Michael J; Nabeshima, Yo-Ichi

2010-07-30

Alpha-Klotho (alphaKl) regulates mineral metabolism such as calcium ion (Ca(2+)) and inorganic phosphate (Pi) in circulation. Defects in mice result in clinical features resembling disorders found in human aging. Although the importance of transmembrane-type alphaKl has been demonstrated, less is known regarding the physiological importance of soluble-type alphaKl (salphaKl) in circulation. The aims of this study were: (1) to establish a sandwich ELISA system enabling detection of circulating serum salphaKl, and (2) to determine reference values for salphaKl serum levels and relationship to indices of renal function, mineral metabolism, age and sex in healthy subjects. We successively developed an ELISA to measure serum salphaKl in healthy volunteers (n=142, males 66) of ages (61.1+/-18.5year). The levels (mean+/-SD) in these healthy control adults were as follows: total calcium (Ca; 9.46+/-0.41mg/dL), Pi (3.63+/-0.51mg/dL), blood urea nitrogen (BUN; 15.7+/-4.3mg/dL), creatinine (Cre; 0.69+/-0.14mg/dL), 1,25 dihydroxyvitamin D (1,25(OH)(2)D; 54.8+/-17.7pg/mL), intact parathyroid hormone (iPTH; 49.2+/-20.6pg/mL), calcitonin (26.0+/-12.3pg/mL) and intact fibroblast growth factor (FGF23; 43.8+/-17.6pg/mL). Serum levels of salphaKl ranged from 239 to 1266pg/mL (mean+/-SD; 562+/-146pg/mL) in normal adults. Although salphaKl levels were not modified by gender or indices of mineral metabolism, salphaKl levels were inversely related to Cre and age. However, salphaKl levels in normal children (n=39, males 23, mean+/-SD; 7.1+/-4.8years) were significantly higher (mean+/-SD; 952+/-282pg/mL) than those in adults (mean+/-SD; 562+/-146, P<0.001). A multivariate linear regression analysis including children and adults in this study demonstrated that salphaKl correlated negatively with age and Ca, and positively with Pi. Finally, we measured a serum salphaKl from a patient with severe tumoral calcinosis derived from a homozygous missense mutation of alpha-klotho gene. In this patient, salphaKl level was notably lower than those of age-matched controls. We established a detection system to measure human serum salphaKl for the first time. Age, Ca and Pi seem to influence serum salphaKl levels in a normal population. This detection system should be an excellent tool for investigating salphaKl functions in mineral metabolism. Copyright 2010 Elsevier Inc. All rights reserved.

Mitigating Backgrounds with a Novel Thin-Film Cathode in the DRIFT-IId Dark Matter Detector

NASA Astrophysics Data System (ADS)

Miller, Eric H.

The nature of dark matter, which comprises 85% of the matter density in the universe, is a major outstanding question in physics today. The standard hypothesis is that the dark matter is a new weakly interacting massive particle, which is present throughout the galaxy. These particles could interact within detectors on Earth, producing low-energy nuclear recoils. Two distinctive signatures arise from the solar motion through the galaxy. The DRIFT experiment aims to measure one of these, the directional signature that is based on the sidereal modulation of the nuclear recoil directions. Although DRIFT has demonstrated its capability for detecting this signature, it has been plagued by a large number of backgrounds that have limited its reach. The focus of this thesis is on characterizing these backgrounds and describing techniques that have essentially eliminated them. The background events in the DRIFT-IId detector are predominantly caused by alpha decays on the central cathode in which the alpha particles completely or partially absorbed by the cathode material. This thesis describes the installation a 0.9 mum thick aluminized-mylar cathode as a way to reduce the probability of producing these backgrounds. We study three generations of cathode (wire, thin-film, and radiologically clean thin-film) with a focus on identifying and quantifying the sources of alpha decay backgrounds, as well as their contributions to the background rate in the detector. This in-situ study is based on alpha range spectroscopy and the determination of the absolute alpha detection efficiency. The results for the final radiologically clean version of the cathode give a contamination of 3.3 +/- 0.1 ppt 234U and 73 +/- 2 ppb 238U, and an efficiency for rejecting an RPR from an alpha decay that is a factor 70 +/- 20 higher than for the original wire cathode. Along with other background reduction measures, the thin-film cathode has reduced the observed background rate from 130/day to 1.7/day in the DRIFT experiment. The complete elimination of the remaining RPR backgrounds requires fiducialization of the detector along the drift direction. We describe two methods for doing this: one involving the detection of positive ions at the cathode, and the other using multiple species of charge carriers with variable drift speeds. With the recent successful implementation of the latter technique, the DRIFT experiment has run background-free for 46 days.

Principles of gross alpha and beta radioactivity detection in water.

PubMed

Semkow, T M; Parekh, P P

2001-11-01

A simultaneous detection of gross alpha and beta radioactivity was studied using gas proportional counting. This measurement is a part of a method mandated by US Environmental Protection Agency to screen for alpha and beta radioactivity in drinking water. Responses of a gas proportional detector to alpha and beta particles from several radionuclides were determined in drop and electroplated geometries. It is shown that, while the alpha radioactivity can be measured accurately in the presence of beta radioactivity, the opposite is not typically true due to alpha-to-beta crosstalk. The crosstalk, originating from the emission of conversion and Auger electrons as well as x rays, is shown to be dependent primarily on the particular alpha-decay scheme while the dependence on alpha energy is small but negligible. It was measured at 28-35% for 241Am, 22-24% for 230Th, and 4.9-6.5% for 239Pu. For 210Po, the crosstalk of 1.2-1.6% was observed mostly due to energy retardation. A method of reducing the crosstalk to a <3% level is proposed by absorbing the atomic electrons in a 6.2 mg cm(-2) Al absorber, at the same time decreasing the beta efficiency by 16-31%.

Significance of detecting circulating hepatocellular carcinoma cells in peripheral blood of hepatocellular carcinoma patients by nested reverse transcription-polymerase chain reaction and its clinical value: a retrospective study.

PubMed

Liu, Yang; Wang, Yue-ru; Wang, Long; Song, Rui-mei; Zhou, Bo; Song, Zhen-shun

2014-01-01

Circulating hepatocellular carcinoma cells may be detected by reverse transcription-polymerase chain reaction. We investigated the relationship between circulating hepatocellular carcinoma cells and hepatoma patient survival after different managements and survival periods. Peripheral vein blood (5 ml) samples were obtained from 113 patients with hepatocellular carcinoma and from 33 control subjects (9 with liver cirrhosis after hepatitis B, 14 with chronic hepatitis B, 10 healthy individuals) between January 1, 2009, and December 31, 2013. To detect circulating hepatocellular carcinoma cells in peripheral blood, alpha-fetoprotein messenger RNA was amplified from total RNA extracted from whole blood by reverse transcription-polymerase chain reaction. Alpha-fetoprotein messenger RNA was detected in 59 blood samples from the hepatocellular carcinoma patients (59/113, 52.2%). In contrast, there were no clinical control subjects whose samples showed detectable alpha-fetoprotein messenger RNA. The presence of alpha-fetoprotein messenger RNA in blood seemed to be correlated with the stage (by TNM classification) of hepatocellular carcinoma, serum alpha-fetoprotein value, and the presence of intrahepatic metastasis, portal vein thrombosis, tumor diameter and/or distant metastasis. In addition, alpha-fetoprotein messenger RNA was detected in the blood of 25 patients showing distant metastasis at extrahepatic organs (100%), in contrast to 32 of 88 cases without metastasis (36.4%). All the patients with hepatocellular carcinoma were followed. Seventeen patients with resection of a T 2 stage hepatocellular carcinoma had a survival of 3.2 years after surgical management, 38 cases with resection of a T3 stage hepatocellular carcinoma had a 1.3-year survival, and only 37 cases with T4 stage disease after different treatments except surgery survived for 0.6 years (P <0.01). The presence of alpha-fetoprotein messenger RNA in peripheral blood may be an indicator of circulating hepatocellular carcinoma cells, which might predict hematogenous spreading metastasis in patients with hepatocellular carcinoma and may be a poor prognostic factor for hepatocellular carcinoma patients.

Evaluation of selected thermal control coatings for long-life space structures

NASA Technical Reports Server (NTRS)

Teichman, Louis A.; Slemp, Wayne S.; Witte, William G., Jr.

1992-01-01

Graphite-reinforced resin matrix composites are being considered for spacecraft structural applications because of their light weight, high stiffness, and lower thermal expansion. Thin protective coatings with stable optical properties and the proper ratio of solar absorption (alpha sub s) to thermal emittance (epsilon) minimize orbital thermal extremes and protect these materials against space environment degradation. Sputtered coatings applied directly to graphite/epoxy composite surfaces and anodized coatings applied to thin aluminum foil were studied for use both as an atomic oxygen barrier and as thermal control coatings. Additional effort was made to develop nickel-based coatings which could be applied directly to composites. These coating systems were selected because their inherent tenacity made them potentially more reliable than commercial white paints for long-life space missions. Results indicate that anodized aluminum foil coatings are suitable for tubular and flat composite structures on large platforms in low Earth orbit. Anodized foil provides protection against some elements of the natural space environment (atomic oxygen, ultraviolet, and particulate radiation) and offers a broad range of tailored alpha sub s/epsilon. The foil is readily available and can be produced in large quantities, while the anodizing process is a routine commercial technique.

The future role of anti-tumour necrosis factor (TNF) products in the treatment of rheumatoid arthritis.

PubMed

Camussi, G; Lupia, E

1998-05-01

Tumour necrosis factor-alpha (TNF alpha) is a pleiotropic cytokine which is overproduced in rheumatoid joints primarily by macrophages. This cytokine has a potential pathogenic role in the establishment of rheumatoid synovitis, in the formation of pannus tissue and in the process of joint destruction, as it increases synoviocyte proliferation and triggers a cascade of secondary mediators involved in the recruitment of inflammatory cells, in neo-angiogenesis and in the process of joint destruction. These findings made TNF alpha a potential target for anticytokine therapy. Experimental studies have shown that TNF alpha blockade by monoclonal antibodies or by soluble TNF receptor reduced the extent and severity of arthritis both in collagen-induced arthritis in mice and in transgenic mice overexpressing TNF alpha, which develop a rheumatoid-like destructive arthritis. Clinical studies based on the use of anti-TNF alpha antibodies or soluble receptors have suggested a potential beneficial effect of TNF alpha-blocking therapy in inducing amelioration of inflammatory parameters in patients with long-standing active disease. In these patients anti-TNF alpha therapy induces a rapid improvement in multiple clinical assessment of disease activity, including morning stiffness, pain score, Ritchie articular index and swollen joint count. The clinical benefits are associated with an improvement in some serological parameters, such as C-reactive protein and serum amyloid-A, erythrocyte sedimentation rate, blood cytokine levels, haemoglobin, white cells and platelet counts, rheumatoid factor titre and histological features of the synovium. However, it remains to be determined whether anti-TNF alpha therapy may be useful in the long term management of rheumatoid patients and in the achievement of better outcomes of disease. Because TNF alpha production also serves a specific function in host defence against infections and tumours, the adverse effects of long term anti-TNF alpha therapy must be carefully evaluated. In addition, targeting a single mediator may be not sufficient to block the complex inflammatory response in rheumatoid arthritis. For these reasons therapeutic strategies aimed at concomitantly interfering with multiple pathogenic pathways are currently under investigation.

Closed-Loop Control of Vortex Formation in Separated Flows

NASA Technical Reports Server (NTRS)

Colonius, Tim; Joe, Won Tae; MacMynowski, Doug; Rowley, Clancy; Taira, Sam; Ahuja, Sunil

2010-01-01

In order to phase lock the flow at the desired shedding cycle, particularly at Phi,best, We designed a feedback compensator. (Even though the open-loop forcing at Wf below Wn can lead to phase-locked limit cycles with a high average lift,) This feedback controller resulted in the phase-locked limit cycles that the open-loop control could not achieve for alpha=30 and 40 Particularly for alpha=40, the feedback was able to stabilize the limit cycle that was not stable with any of the open-loop periodic forcing. This results in stable phase-locked limit cycles for a larger range of forcing frequencies than the open-loop control. Also, it was shown that the feedback achieved the high-lift unsteady flow states that open-loop control could not sustain even after the states have been achieved for a long period of time.

The highly obscured nucleus of 3C 219

NASA Technical Reports Server (NTRS)

Fabbiano, G.; Willner, S. P.; Carleton, N. P; Elvis, M.

1986-01-01

The detection of a strong, and possibly broad, Paschen-alpha line from the narrow-line radio galaxy 3C 219 is reported. The detected flux is larger than predicted from the H-alpha line and the case B recombination. This implies the presence of a highly reddened line-emitting region in the nucleus.

Schindler disease: the molecular lesion in the alpha-N-acetylgalactosaminidase gene that causes an infantile neuroaxonal dystrophy.

PubMed Central

Wang, A M; Schindler, D; Desnick, R

1990-01-01

Schindler disease is a recently recognized infantile neuroaxonal dystrophy resulting from the deficient activity of the lysosomal hydrolase, alpha-N-acetylgalctosaminidase (alpha-GalNAc). The recent isolation and expression of the full-length cDNA encoding alpha-GalNAc facilitated the identification of the molecular lesions in the affected brothers from family D, the first cases described with this autosomal recessive disease. Southern and Northern hybridization analyses of DNA and RNA from the affected homozygotes revealed a grossly normal alpha-GalNAc gene structure and normal transcript sizes and amounts. Therefore, the alpha-GalNAc transcript from an affected homozygote was reverse-transcribed, amplified by the polymerase chain reaction (PCR), and sequenced. A single G to A transition at nucleotide 973 was detected in multiple subclones containing the PCR products. This point mutation resulted in a glutamic acid to lysine substitution in residue 325 (E325K) of the alpha-GalNAc polypeptide. The base substitution was confirmed by dot blot hybridization analyses of PCR-amplified genomic DNA from family members with allele-specific oligonucleotides. Furthermore, transient expression of an alpha-GalNAc construct containing the E325K mutation resulted in the expression of an immunoreactive polypeptide which had no detectable alpha-GalNAc activity. Images PMID:2243144

Characterization of Si p-i-n diode for scanning transmission ion microanalysis of biological samples

NASA Astrophysics Data System (ADS)

Devès, G.; Matsuyama, S.; Barbotteau, Y.; Ishii, K.; Ortega, R.

2006-05-01

The performance of a silicon p-i-n diode (Hamamatsu S1223-01) for the detection of charged particles was investigated and compared with the response of a standard passivated implanted planar silicon (PIPS) detector. The photodiode was characterized by ion beam induced charge collection with a micrometer spatial resolution using proton and alpha particle beams in the 1-3MeV energy range. Results indicate that homogeneity, energy resolution, and reproducibility of detection of charged particles enable the use of the low cost silicon p-i-n device as a replacement of conventional PIPS detector during scanning transmission ion microanalysis experiments. The Si p-i-n diode detection setup was successfully applied to scanning transmission ion microscopy determination of subcellular compartments on human cancer cultured cells.

Long range surface plasmon resonance with ultra-high penetration depth for self-referenced sensing and ultra-low detection limit using diverging beam approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Isaacs, Sivan, E-mail: sivan.isaacs@gmail.com; Abdulhalim, Ibrahim; NEW CREATE Programme, School of Materials Science and Engineering, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602

2015-05-11

Using an insulator-metal-insulator structure with dielectric having refractive index (RI) larger than the analyte, long range surface plasmon (SP) resonance exhibiting ultra-high penetration depth is demonstrated for sensing applications of large bioentities at wavelengths in the visible range. Based on the diverging beam approach in Kretschmann-Raether configuration, one of the SP resonances is shown to shift in response to changes in the analyte RI while the other is fixed; thus, it can be used as a built in reference. The combination of the high sensitivity, high penetration depth and self-reference using the diverging beam approach in which a dark linemore » is detected of the high sensitivity, high penetration depth, self-reference, and the diverging beam approach in which a dark line is detected using large number of camera pixels with a smart algorithm for sub-pixel resolution, a sensor with ultra-low detection limit is demonstrated suitable for large bioentities.« less

Glycosidases in Brachionus plicatilis (Rotifera).

PubMed

Kühle, K; Kleinow, W

1990-01-01

1. Tests for glycosidases were performed in homogenates of Brachionus plicatilis. 2. Hydrolytic activity was detected with the following substrates: (a) with synthetic substrates (NP = 4-nitrophenyl): NP-alpha- and NP-beta-D-glucopyranoside, NP-alpha- and NP-beta-D-galactopyranoside, NP-N-acetyl-beta-D-glucosaminide, NP-N-acetyl-beta-D-galactosaminide, NP-alpha- and NP-beta-D-mannopyranoside and NP-alpha-L-fucopyranoside; (b) with disaccharides: sucrose, maltose, trehalose, isomaltose, cellobiose, gentiobiose and lactose; (c) with polysaccharides: laminarine, carboxymethyl-cellulose, avicel, Micrococcus luteus (for lysozyme) and 4-nitrophenyl-alpha-D-maltoheptaoside (for amylase). 3. The pH dependence of the glycosidase activities was determined. 4. The distribution of enzyme activities within fractions from the homogenate was studied in order to localize them within the cell. 5. Proteins from Brachionus homogenate were separated by SDS-gel electrophoresis and the positions of the following glycosidase activities were detected by assays performed on the gels (estimated molecular weights in parentheses): alpha-glucosidase (250,000); beta-glucosidase (200,000); beta-galactosidase (70,000); N-acetyl-beta-glucosaminidase (60,000).

Correlation between spontaneous apoptosis and the expression of angiogenic factors in advanced gastric adenocarcinoma.

PubMed

Ikeguchi, M; Cai, J; Fukuda, K; Oka, S; Katano, K; Tsujitani, S; Maeta, M; Kaibara, N

2001-06-01

The aim of this study was to investigate whether angiogenic factors influence the occurrence of spontaneous apoptosis in advanced gastric cancer. The apoptotic indices (AIs) of 97 tumors from 97 patients with advanced gastric cancer (pT3, pN0, pM0, Stage II) were analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) method. Intratumoral microvessel densities (IMVDs) of tumors stained with anti-CD34 monoclonal antibody were quantified under x 200 magnification using computer-assisted image analysis. The expressions of angiogenic factors, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (dThdPase), transforming growth factor-alpha (TGF-alpha), and p53 were analyzed immunohistochemically and compared with IMVDs and AIs. The mean IMVD of the 97 tumors was 365/mm2 (range 147-990/mm2). The mean AI of tumors was 2.1% (range 0-11.3%). A significant inverse correlation between the AIs and the IMVDs was shown (p = -0.278, P = 0.0064). The mean IMVDs of tumors with high expressions of dThdPase, TGF-alpha, or p53 were significantly higher than those of tumors with low expressions of these factors. The mean AI of tumors with high expressions of dThdPase was significantly lower than that of tumors with low expressions of dThdPase (P = 0.023). However, no significant correlations were detected between AIs and the expression levels of VEGF, TGF-alpha, or p53. In gastric cancer, dThdPase may play an important role in tumor progression by increasing microvessels and by suppressing apoptosis of cancer cells.

Effects of 6 months of aging in water on hardness and surface roughness of two microhybrid dental composites.

PubMed

de Moraes, Rafael Ratto; Marimon, José Laurindo Machado; Schneider, Luis Felipe; Sinhoreti, Mário Alexandre Coelho; Correr-Sobrinho, Lourenço; Bueno, Márcia

2008-06-01

This study assessed the effect of 6 months of aging in water on surface roughness and surface/subsurface hardness of two microhybrid resin composites. Filtek Z250 and Charisma were tested. Cylindrical specimens were obtained and stored in distilled water for 24 hours or 6 months, at 37 degrees C. For Knoop hardness evaluation, the specimens were transversely wet-flattened, and indentations were made on surface and subsurface layers. Data were submitted to three-way ANOVA and Tukey's test (alpha < or = 0.05). Surface roughness baseline measurements were made at 24 hours and repeated after 6 months of storage. Data were submitted to repeated measures ANOVA and Tukey's test (alpha < or = 0.05). Surface hardness (KHN, kg/mm(2)) means (+/- standard deviation) ranged from 55 +/- 1 to 49 +/- 4 for Z250 and from 50 +/- 2 to 41 +/- 3 for Charisma, at 24 hours and 6 months, respectively. Subsurface means ranged from 58 +/- 2 to 61 +/- 3 for Z250 and from 50 +/- 1 to 54 +/- 2 for Charisma, at 24 hours and 6 months. For both composites, the aged specimens presented significantly softer surfaces (p < 0.01). For the subsurface hardness, alteration after storage was detected only for Charisma, which presented a significant rise in hardness (p < 0.01). Z250 presented significantly harder surface and subsurface layers in comparison with Charisma. Surface roughness (Ra, mum) means ranged from 0.07 +/- 0.00 to 0.07 +/- 0.01 for Z250 and from 0.06 +/- 0.01 to 0.07 +/- 0.01 for Charisma, at 24 hours and 6 months, respectively. For both composites, no significant roughness alteration was detected during the study (p= 0.386). The 6-month period of storage in water presented a significant softening effect on the surfaces of the composites, although no significant deleterious alteration was detected for the subsurface hardness. In addition, the storage period had no significant effect on the surface roughness of the materials.

C(18) columns for the simultaneous determination of oxytetracycline and its related substances by reversed-phase high performance liquid chromatography and UV detection.

PubMed

Smyrniotakis, C G; Archontaki, Helen A

2007-01-17

Simultaneous determination of oxytetracycline, 4-epioxytetracycline, alpha-apooxytetracycline, tetracycline and beta-apooxytetracycline on C(18) columns has been accomplished using a high performance liquid chromatographic method with UV detection. Separation was achieved on a Hypersil BDS RP-C(18) column (250 mm x 4.6 mm) and on a Waters C(18) Symmetry column (150 mm x 3.9mm), 5 microm particle size each. These columns were equilibrated with mobile phases consisted of methanol-acetonitrile-0.1M phosphate buffer pH 8.0 (12.5:12.5:75, v/v/v) and (15:15:70, v/v/v), respectively. The flow rate was 1.0 ml/min and the total elution time was 15 and 5 min, respectively. Both methods were applied to oxytetracycline raw material, human and veterinary formulations, where the excipients did not interfere. External standard calibration curves were linear for 4-epioxytetracycline, oxytetracycline, alpha-apooxytetracycline, tetracycline and beta-apooxytetracycline in the concentration range of 0.27-200 microM, 0.05-200 microM, 0.03-200 microM, 0.35-200 microM and 0.20-200 microM on column A and 0.08-200 microM, 0.15-200 microM, 0.09-200 microM, 0.25-200 microM and 0.47-200 microM on column B, respectively. Day-to-day relative standard deviation of the determination for every component was less than 3%. Concerning the first column, limits of detection and quantification of the above compounds were in the concentration ranges of 10-106 nM and 30-352 nM, respectively, whereas on the second column these ranges became 27-144 nM and 81-475 nM, respectively. Recovery of the separated compounds was 95-105%.

Evaluation of IgY capture ELISA for sensitive detection of alpha hemolysin of Staphylococcus aureus without staphylococcal protein A interference.

PubMed

Reddy, Prakash Kudumala; Shekar, Aravind; Kingston, Joseph Jeyabalaji; Sripathy, Murali Harishchandra; Batra, Harshvardhan

2013-05-31

Staphylococcal protein A (Spa) secreted by all Staphylococcus aureus strains is the major hindrance in development of specific immunoassays for detecting S. aureus antigens, because of its characteristic feature of binding to Fc region of most mammalian immunoglobulins and also to Fab region of certain classes of mammalian immunoglobulins. Immunoglobulin Y (IgY) is the avian equivalent of mammalian IgG which does not have any affinity to Spa. In the present study we report that using chicken egg yolk IgY over mammalian IgG as capture antibody prevents both soluble and surface bound protein A from causing false positives quantified by chicken anti-protein A antibodies. This was demonstrated by development of sandwich ELISA for detection of alpha hemolysin toxin from culture supernatants of S. aureus strains with anti alpha hemolysin IgY as capture and rabbit anti alpha hemolysin IgG as revealing antibody. This indirect sandwich ELISA was evaluated onto a large number of S. aureus isolates recovered from clinical sources for alpha hemolysin secretion. Results of sandwich ELISA were compared with PCR and Western blot analysis. The immunoassay is highly specific and has high sensitivity of detecting less than 1 ng/ml. This procedure is highly effective in eliminating Spa interference and can be extended to detection of other important superantigen toxins of S. aureus. Copyright © 2013 Elsevier B.V. All rights reserved.

Protective specific immunity induced by cyclophosphamide plus tumor necrosis factor alpha combination treatment of EL4-lymphoma-bearing C57BL/6 mice.

PubMed

Krawczyk, C M; Verstovsek, S; Ujházy, P; Maccubbin, D; Ehrke, M J

1995-06-01

A combination treatment protocol initiated 12 days after tumor injection, when the tumor was large, by administering cyclophosphamide (CY, 150 or 250 mg/kg) intraperitoneally followed by intravenous tumor necrosis factor alpha (TNF alpha, 1000 units injection) on days 13, 16, 18, 21, and 23, resulted in about 60% long-term survival (i.e., survival for at least 60 days) in the syngeneic C57BL/6 mouse/EL4 lymphoma model system. The establishment of a specific antitumor immune memory and its possible therapeutic relevance was verified by reinjecting 60-day survivors with EL4 cells; all 60-day survivors that had received the combination treatments rejected the implants and survived for a further 60 days. Thymic cellularity was reduced during treatment and its recovery appeared to correlate with long-term survival and immunity. Thymocytes from mice treated with the combination were found to express significant levels of specific anti-EL4 cytolytic activity following a 4-day stimulation culture with X-irradiated EL4 cells and low concentrations of interleukin-2. This response could not be generated with thymocytes from naive animals. In each case the effect seen with the combination of a moderate CY dose (150 mg/kg) with TNF alpha was better than that seen with either dose of CY alone and equal to or better than that seen with the higher dose of CY combined with TNF alpha. These results indicate that treatment with a single moderate dose of CY in combination with TNF alpha is effective against a large, established tumor in this murine model. Furthermore, all the long-term survivors induced by this treatment developed protective immunity against reimplanted tumor and demonstrated a long-term specific immune memory in the thymus.

THE CORES OF THE Fe K{alpha} LINES IN ACTIVE GALACTIC NUCLEI: AN EXTENDED CHANDRA HIGH ENERGY GRATING SAMPLE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shu, X. W.; Wang, J. X.; Yaqoob, T.

We extend the study of the core of the Fe K{alpha} emission line at {approx}6.4 keV in Seyfert galaxies reported by Yaqoob and Padmanabhan using a larger sample observed by the Chandra high-energy grating (HEG). The sample consists of 82 observations of 36 unique sources with z < 0.3. Whilst heavily obscured active galactic nuclei are excluded from the sample, these data offer some of the highest precision measurements of the peak energy of the Fe K{alpha} line, and the highest spectral resolution measurements of the width of the core of the line in unobscured and moderately obscured (N {submore » H} < 10{sup 23} cm{sup -2}) Seyfert galaxies to date. From an empirical and uniform analysis, we present measurements of the Fe K{alpha} line centroid energy, flux, equivalent width (EW), and intrinsic width (FWHM). The Fe K{alpha} line is detected in 33 sources, and its centroid energy is constrained in 32 sources. In 27 sources, the statistical quality of the data is good enough to yield measurements of the FWHM. We find that the distribution in the line centroid energy is strongly peaked around the value for neutral Fe, with over 80% of the observations giving values in the range 6.38-6.43 keV. Including statistical errors, 30 out of 32 sources ({approx}94%) have a line centroid energy in the range 6.35-6.47 keV. The mean EW, among the observations in which a non-zero lower limit could be measured, was 53 {+-} 3 eV. The mean FWHM from the subsample of 27 sources was 2060 {+-} 230 km s{sup -1}. The mean EW and FWHM are somewhat higher when multiple observations for a given source are averaged. From a comparison with the H{beta} optical emission-line widths (or, for one source, Br{alpha}), we find that there is no universal location of the Fe K{alpha} line-emitting region relative to the optical broad-line region (BLR). In general, a given source may have contributions to the Fe K{alpha} line flux from parsec-scale distances from the putative black hole, down to matter a factor {approx}2 closer to the black hole than the BLR. We confirm the presence of the X-ray Baldwin effect, an anti-correlation between the Fe K{alpha} line EW and X-ray continuum luminosity. The HEG data have enabled isolation of this effect to the narrow core of the Fe K{alpha} line.« less

Confirmatory analysis of 17beta-boldenone, 17alpha-boldenone and androsta-1,4-diene-3,17-dione in bovine urine by liquid chromatography-tandem mass spectrometry.

PubMed

Draisci, Rosa; Palleschi, Luca; Ferretti, Emanuele; Lucentini, Luca; delli Quadri, Fernanda

2003-06-15

A sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for confirmatory analysis of 17beta-boldenone (17beta-BOL), 17alpha-boldenone (17alpha-BOL) and androsta-1,4-diene-3,17-dione (ADD) in bovine urine was developed. [2H(2)]17beta-Testosterone (17beta-T-d(2)) was used as the internal standard. Sample preparation involved enzymatic hydrolysis and purification on a C(18) solid-phase extraction column. Chromatographic separation of the analytes was obtained using an RP-C(18) HPLC column. LC-MS-MS detection was carried out with an atmospheric pressure chemical ionisation (APCI) source equipped with a heated nebulizer (HN) interface operating in the positive ion mode. For unambiguous hormone confirmation, three analyte precursor-product ion combinations were monitored during multiple-reaction monitoring (MRM) LC-MS-MS analysis. Overall recovery (%), repeatability (relative standard deviations, RSD, %) and within-laboratory reproducibility (RSD, %) ranged from 92.2 to 97.7%, from 6.50 to 2.94% and from 13.50 to 5.04%, respectively, for all analytes. The limit of quantification in bovine urine was 0.20 ng ml(-1) for 17beta-BOL and ADD and 0.50 ng ml(-1) for 17alpha-BOL. The validated method was successfully applied for determination of 17beta-BOL, 17alpha-BOL and ADD in a large number of bovine urine samples collected within the national Official Residue Control Program.

Feasibility of observing the α decay chains from isotopes of SHN with Z = 128, Z = 126, Z = 124 and Z = 122

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Priyanka, B.; Nithya, C.

2016-11-01

Within the Coulomb and proximity potential model for deformed nuclei (CPPMDN), the alpha decay properties of 34 isotopes of the superheavy nuclei with Z = 128 within the range 306 ≤ A ≤ 339 have been studied, considering both the parent and daughter nuclei to be deformed. The manuscript also deals with the decay properties of the isotopes of Z = 126 (within 288 ≤ A ≤ 339), Z = 124 (within 284 ≤ A ≤ 339) and Z = 122 (within 280 ≤ A ≤ 339). The alpha decay half lives thus evaluated have been compared with the values evaluated using other theoretical models and it was seen that, our theoretical alpha decay half lives match well with these values. Through the present study, we have underlined and have established the fact that, among the 192 isotopes considered in the present study, only those isotopes 321-324,328-335128, 318-320,323-327126, 305-308,315-322124 and 298-307,311-314122 can be synthesised and detected through alpha decay in laboratory. As the alpha decay half lives of these superheavy isotopes lie within the experimental limits, we hope these predictions, on the decay modes of these unknown nuclei, to pave the way for the future experiments. The proton separation energy calculations on 306-339128, 288-336126, 284-339124 and 280-339122 superheavy nuclei have also been done and the study revealed the probable proton emitters among these nuclei.

Mechanistic basis for estrogenic effects in fathead minnow (Pimephales promelas) following exposure to the androgen 17alpha-methyltestosterone: conversion of 17alpha-methyltestosterone to 17alpha-methylestradiol.

PubMed

Hornung, Michael W; Jensen, Kathleen M; Korte, Joseph J; Kahl, Michael D; Durhan, Elizabeth J; Denny, Jeffrey S; Henry, Tala R; Ankley, Gerald T

2004-01-07

Exposure of adult fathead minnows (Pimephales promelas) to the androgen 17alpha-methyltestosterone (MT) produces both androgenic and estrogenic effects, manifested as nuptial tubercle formation in females, and vitellogenin production in males and females, respectively. The present study was conducted to determine if the unanticipated estrogenic effects are produced by conversion of MT via aromatase activity to 17alpha-methylestradiol (ME2). Aromatase activity at the end of a 7-day waterborne MT exposure (20, 200microg/l) was significantly decreased in ovarian microsomes and brain homogenates from exposed fish, to about 30-50% of control activity. Although aromatase activity was decreased by 7 days, it is possible that the conversion of MT to ME2 occurred soon after initial exposure. In support of this, ME2 was detected in plasma samples of the fish following the 7-day exposure, confirming their ability convert the androgen MT to the estrogen ME2. The concentration of ME2 in plasma was within the range of plasma 17ss-estradiol (E2) found in control female fathead minnows (4-5ng/ml). These results, in conjunction with competitive binding assays that indicate ME2 binds to the fathead minnow estrogen receptor with a relative binding affinity of 68.3% of E2, support the hypothesis that aromatization of MT to ME2 contributes to the estrogenic effects in fathead minnows following exposure to this androgen.

Alpha phase determines successful lexical decision in noise.

PubMed

Strauß, Antje; Henry, Molly J; Scharinger, Mathias; Obleser, Jonas

2015-02-18

Psychophysical target detection has been shown to be modulated by slow oscillatory brain phase. However, thus far, only low-level sensory stimuli have been used as targets. The current human electroencephalography (EEG) study examined the influence of neural oscillatory phase on a lexical-decision task performed for stimuli embedded in noise. Neural phase angles were compared for correct versus incorrect lexical decisions using a phase bifurcation index (BI), which quantifies differences in mean phase angles and phase concentrations between correct and incorrect trials. Neural phase angles in the alpha frequency range (8-12 Hz) over right anterior sensors were approximately antiphase in a prestimulus time window, and thus successfully distinguished between correct and incorrect lexical decisions. Moreover, alpha-band oscillations were again approximately antiphase across participants for correct versus incorrect trials during a later peristimulus time window (∼500 ms) at left-central electrodes. Strikingly, lexical decision accuracy was not predicted by either event-related potentials (ERPs) or oscillatory power measures. We suggest that correct lexical decisions depend both on successful sensory processing, which is made possible by the alignment of stimulus onset with an optimal alpha phase, as well as integration and weighting of decisional information, which is coupled to alpha phase immediately following the critical manipulation that differentiated words from pseudowords. The current study constitutes a first step toward characterizing the role of dynamic oscillatory brain states for higher cognitive functions, such as spoken word recognition. Copyright © 2015 the authors 0270-6474/15/353256-07$15.00/0.

Optical Absorption in Liquid Semiconductors

NASA Astrophysics Data System (ADS)

Bell, Florian Gene

An infrared absorption cell has been developed which is suitable for high temperature liquids which have absorptions in the range .1-10('3) cm('-1). The cell is constructed by clamping a gasket between two flat optical windows. This unique design allows the use of any optical windows chemically compatible with the liquid. The long -wavelength limit of the measurements is therefore limited only by the choice of the optical windows. The thickness of the cell can easily be set during assembly, and can be varied from 50 (mu)m to .5 cm. Measurements of the optical absorption edge were performed on the liquid alloy Se(,1-x)Tl(,x) for x = 0, .001, .002, .003, .005, .007, and .009, from the melting point up to 475(DEGREES)C. The absorption was found to be exponential in the photon energy over the experimental range from 0.3 eV to 1.2 eV. The absorption increased linearly with concentration according to the empirical relation (alpha)(,T)(h(nu)) = (alpha)(,1) + (alpha)(,2)x, and the absorption (alpha)(,1) was interpreted as the absorption in the absence of T1. (alpha)(,1) also agreed with the measured absorption in 100% Se at corresponding temperatures and energies. The excess absorption defined by (DELTA)(alpha) = (alpha)(,T)(h(nu))-(alpha)(,1) was interpreted as the absorption associated with Tl and was found to be thermally activated with an activation energy E(,t) = 0.5 eV. The exponential edge is explained as absorption on atoms immersed in strong electric fields surrounding ions. The strong fields give rise to an absorption tail similar to the Franz-Keldysh effect. A simple calculation is performed which is based on the Dow-Redfield theory of absorption in an electric field with excitonic effects included. The excess absorption at low photon energies is proportional to the square of the concentration of ions, which are proposed to exist in the liquid according to the relation C(,i) (PROPORTIONAL) x(' 1/2)(.)e('-E)t('/kT), which is the origin of the thermal activation and the proportionality to Tl concentration. The ionic model satisfactorily explains the observed concentration and temperature dependence of the absorption. It also provides for the first time, a universal explanation of the exponential edge in liquid semiconductors where charged defects are present, and provides a means of measuring the concentration of ions when the absorption can be calibrated.

Diastereoselective addition of 2H-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines.

PubMed

Pirat, Jean-Luc; Monbrun, Jérôme; Virieux, David; Volle, Jean-Noël; Tillard, Monique; Cristau, Henri-Jean

2005-09-02

[reaction: see text] Diastereoselective additions of 2-hydrogeno-2-oxo-1,4,2-oxazaphosphinanes to aldehydes and imines are described. alpha,alpha'-Diaminophosphinic and alpha-amino-alpha'-hydroxyphosphinic derivatives were obtained with de's ranging from 24 to 90%.

Fertility in a high-altitude environment is compromised by luteal dysfunction: the relative roles of hypoxia and oxidative stress

PubMed Central

2013-01-01

Background At high altitudes, hypoxia, oxidative stress or both compromise sheep fertility. In the present work, we tested the relative effect of short- or long-term exposure to high altitude hypobaric hypoxia and oxidative stress on corpora luteal structure and function. Methods The growth dynamics of the corpora lutea during the estrous cycle were studied daily by ultrasonography in cycling sheep that were either native or naïve to high-altitude conditions and that were supplemented or not supplemented with antioxidant vitamins. Arterial and venous blood samples were simultaneously drawn for determination of gases and oxidative stress biomarkers and progesterone measurement. On day five after ovulation in the next cycle, the ovaries were removed for immunodetection of luteal HIF-1alpha and VEGF and IGF-I and to detect IGF-II gene expression. Results The results showed that both short- and long-term exposure to high-altitude conditions decreased luteal growth and IGF-I and IGF-II gene expression but increased HIF-1 alpha and VEGF immunoexpression. The level of plasma progesterone was also increased at a high altitude, although an association with increased corpus luteum vascularization was only found in sheep native to a high-altitude location. Administration of antioxidant vitamins resulted in a limited effect, which was restricted to decreased expression of oxidative stress biomarkers and luteal HIF-1alpha and VEGF immunoexpression. Conclusions Exposure of the sheep to high-altitude hypobaric hypoxia for short or long time periods affects the development and function of the corpus luteum. Moreover, the observed association of oxidative stress with hypoxia and the absence of any significant effect of antioxidant vitamins on most anatomical and functional corpus luteum traits suggests that the effects of high altitude on this ovarian structure are mainly mediated by hypoxia. Thus, these findings may help explain the decrease in sheep fertility at a high altitude. PMID:23521851

Fertility in a high-altitude environment is compromised by luteal dysfunction: the relative roles of hypoxia and oxidative stress.

PubMed

Parraguez, Víctor H; Urquieta, Bessie; Pérez, Laura; Castellaro, Giorgio; De los Reyes, Mónica; Torres-Rovira, Laura; Aguado-Martínez, Adriana; Astiz, Susana; González-Bulnes, Antonio

2013-03-23

At high altitudes, hypoxia, oxidative stress or both compromise sheep fertility. In the present work, we tested the relative effect of short- or long-term exposure to high altitude hypobaric hypoxia and oxidative stress on corpora luteal structure and function. The growth dynamics of the corpora lutea during the estrous cycle were studied daily by ultrasonography in cycling sheep that were either native or naïve to high-altitude conditions and that were supplemented or not supplemented with antioxidant vitamins. Arterial and venous blood samples were simultaneously drawn for determination of gases and oxidative stress biomarkers and progesterone measurement. On day five after ovulation in the next cycle, the ovaries were removed for immunodetection of luteal HIF-1alpha and VEGF and IGF-I and to detect IGF-II gene expression. The results showed that both short- and long-term exposure to high-altitude conditions decreased luteal growth and IGF-I and IGF-II gene expression but increased HIF-1 alpha and VEGF immunoexpression. The level of plasma progesterone was also increased at a high altitude, although an association with increased corpus luteum vascularization was only found in sheep native to a high-altitude location. Administration of antioxidant vitamins resulted in a limited effect, which was restricted to decreased expression of oxidative stress biomarkers and luteal HIF-1alpha and VEGF immunoexpression. Exposure of the sheep to high-altitude hypobaric hypoxia for short or long time periods affects the development and function of the corpus luteum. Moreover, the observed association of oxidative stress with hypoxia and the absence of any significant effect of antioxidant vitamins on most anatomical and functional corpus luteum traits suggests that the effects of high altitude on this ovarian structure are mainly mediated by hypoxia. Thus, these findings may help explain the decrease in sheep fertility at a high altitude.

Influence of the dispersive and dissipative scales alpha and beta on the energy spectrum of the Navier-Stokes alphabeta equations.

PubMed

Chen, Xuemei; Fried, Eliot

2008-10-01

Lundgren's vortex model for the intermittent fine structure of high-Reynolds-number turbulence is applied to the Navier-Stokes alphabeta equations and specialized to the Navier-Stokes alpha equations. The Navier-Stokes alphabeta equations involve dispersive and dissipative length scales alpha and beta, respectively. Setting beta equal to alpha reduces the Navier-Stokes alphabeta equations to the Navier-Stokes alpha equations. For the Navier-Stokes alpha equations, the energy spectrum is found to obey Kolmogorov's -5/3 law in a range of wave numbers identical to that determined by Lundgren for the Navier-Stokes equations. For the Navier-Stokes alphabeta equations, Kolmogorov's -5/3 law is also recovered. However, granted that beta < alpha, the range of wave numbers for which this law holds is extended by a factor of alphabeta . This suggests that simulations based on the Navier-Stokes alphabeta equations may have the potential to resolve features smaller than those obtainable using the Navier-Stokes alpha equations.

Specific 13C labeling of leucine, valine and isoleucine methyl groups for unambiguous detection of long-range restraints in protein solid-state NMR studies

NASA Astrophysics Data System (ADS)

Fasshuber, Hannes Klaus; Demers, Jean-Philippe; Chevelkov, Veniamin; Giller, Karin; Becker, Stefan; Lange, Adam

2015-03-01

Here we present an isotopic labeling strategy to easily obtain unambiguous long-range distance restraints in protein solid-state NMR studies. The method is based on the inclusion of two biosynthetic precursors in the bacterial growth medium, α-ketoisovalerate and α-ketobutyrate, leading to the production of leucine, valine and isoleucine residues that are exclusively 13C labeled on methyl groups. The resulting spectral simplification facilitates the collection of distance restraints, the verification of carbon chemical shift assignments and the measurement of methyl group dynamics. This approach is demonstrated on the type-three secretion system needle of Shigella flexneri, where 49 methyl-methyl and methyl-nitrogen distance restraints including 10 unambiguous long-range distance restraints could be collected. By combining this labeling scheme with ultra-fast MAS and proton detection, the assignment of methyl proton chemical shifts was achieved.

Activation of alpha-latrotoxin receptors in neuromuscular synapses leads to a prolonged splash acetylcholine release.

PubMed

Lelyanova, V G; Thomson, D; Ribchester, R R; Tonevitsky, E A; Ushkaryov, Y A

2009-06-01

The mechanisms of acetylcholine release in presynaptic terminals of motoneurons induced by mutant alpha-latrotoxin (LT(N4C)) were analyzed. In contrast to wild-type alpha-latrotoxin that causes both continuous and splash secretion of acetylcholine and necessarity block neuromuscular transmission, LT(N4C) causes only splash release lasting over many hours. Thus, activation of alpha-latrotoxin receptors controls long-lasting enhanced secretion of acetylcholine.

Role of constant value of surface diffuseness in alpha decay half-lives of superheavy nuclei

NASA Astrophysics Data System (ADS)

Dehghani, V.; Alavi, S. A.; Benam, Kh.

2018-05-01

By using WKB method and considering deformed Woods-Saxon nuclear potential, deformed Coulomb potential, and centrifugal potential, the alpha decay half-lives of 68 superheavy alpha emitters have been calculated. The effect of the constant value of surface diffuseness parameter in the range of 0.1 ≤ a ≤ 0.9 (fm) on the potential barrier, tunneling probability, assault frequency, and alpha decay half-lives has been investigated. Significant differences were observed for alpha decay half-lives and decay quantities in this range of surface diffuseness. Good agreement between calculated half-lives with fitted surface diffuseness parameter a = 0.54 (fm) and experiment was observed.

Hepatocellular carcinoma in biliary atresia: King's College Hospital experience.

PubMed

Hadžić, Nedim; Quaglia, Alberto; Portmann, Bernard; Paramalingam, Saravanakumar; Heaton, Nigel D; Rela, Mohamed; Mieli-Vergani, Giorgina; Davenport, Mark

2011-10-01

To establish risks for development of hepatocellular carcinoma (HCC) in children with biliary atresia (BA), the most common chronic liver disease of childhood. In our tertiary referral center database we have identified children with BA who had development of or have been incidentally found to have HCC. Their demographic, clinical, radiologic, and histologic features were analyzed. Between 1990 and 2008, 387 infants were diagnosed with BA at our center. Of these, three (0.8 %) who underwent operation at a median age of 68 (range 66 to 71) days had development of a histologically proven HCC detected at a median age of 2.1 (range 1.8 to 4.9) years. Another two, referred later, were diagnosed with HCC on their liver explants at ages 1.1 and 17.75 years, respectively. Overall, two had elevated serum levels of alpha-fetoprotein. All five children underwent successful liver transplantation at a median age of 2.1 years (range 1.1 to 17.75) and remain well after a median of 2.5 (range 2 to 5.7) years. HCC develops in a small percentage of children with BA. Serum alpha-fetoprotein levels and ultrasound screening are helpful but not absolute markers of the malignant change. In the absence of the extrahepatic involvement, liver transplantation represents an effective treatment. Copyright © 2011 Mosby, Inc. All rights reserved.

Memory and long-range correlations in chess games

NASA Astrophysics Data System (ADS)

Schaigorodsky, Ana L.; Perotti, Juan I.; Billoni, Orlando V.

2014-01-01

In this paper we report the existence of long-range memory in the opening moves of a chronologically ordered set of chess games using an extensive chess database. We used two mapping rules to build discrete time series and analyzed them using two methods for detecting long-range correlations; rescaled range analysis and detrended fluctuation analysis. We found that long-range memory is related to the level of the players. When the database is filtered according to player levels we found differences in the persistence of the different subsets. For high level players, correlations are stronger at long time scales; whereas in intermediate and low level players they reach the maximum value at shorter time scales. This can be interpreted as a signature of the different strategies used by players with different levels of expertise. These results are robust against the assignation rules and the method employed in the analysis of the time series.

Measurement of vitamin D3 metabolites in smelter workers exposed to lead and cadmium

PubMed Central

Chalkley, S. R.; Richmond, J.; Barltrop, D.

1998-01-01

OBJECTIVES: To investigate the effects of lead and cadmium on the metabolic pathway of vitamin D3. METHODS: Blood and urinary cadmium and urinary total proteins were measured in 59 smelter workers occupationally exposed to lead and cadmium. In 19 of these workers, the plasma vitamin D3 metabolites, (25-hydroxycholecalciferol (25 OHD3), 24R, 25-dihydroxycholecalciferol (24R,25(OH)2D3) and 1 alpha,25- dihydroxycholecalciferol (1 alpha, 25(OH)2D3)) were measured together with blood lead. Vitamin D3 metabolites were measured by radioimmunoassay, (RIA), lead and cadmium by atomic absorption spectrophotometry, and total proteins with a test kit. RESULTS: Ranges for plasma 25(OH)D3, 24R,25(OH)2D3 and 1 alpha,25(OH)2D3 were 1.0-51.9 ng/ml, 0.6-5.8 ng/ml, and 0.1-75.7 pg/ml, respectively. Ranges for blood lead were 1-3.7 mumol/l, (21-76 micrograms/dl), blood cadmium 6- 145 nmol/l, and urinary cadmium 3-161 nmol/l. Total proteins in random urine samples were 2.1-32.6 mg/dl. Concentrations of lead and cadmium in blood showed no correlation (correlation coefficient -0.265) but there was a highly significant correlation between blood and urinary cadmium. Concentrations for 24R,25(OH)2D3 were depressed below the normal range as blood and urinary cadmium increased, irrespective of lead concentrations. High cadmium concentrations were associated with decreased plasma 1 alpha,25(OH)2D3 when lead concentrations were < 1.9 mumol/l and with above normal plasma 1 alpha,25(OH)2D3 when lead concentrations were > 1.9 mumol/l, Kruskal-Wallis analysis of variance (K-W ANOVA) chi 2 = 10.3, p = 0.006. Plasma 25(OH)D3 was negatively correlated with both urinary total proteins and urinary cadmium, but showed no correlation with plasma 24R,25(OH)2D3, 1 alpha,25(OH)2D3, blood lead, or blood cadmium. CONCLUSION: Continuous long term exposure to cadmium may result in a state of equilibrium between blood and urinary cadmium. Cadmium concentrations in blood could be predicted from the cadmium concentration of the urine, (regression coefficient +0.35 SE 0.077). Exposure to cadmium alone decreased the concentrations of 1 alpha,25(OH)2D3 and 24R,25(OH)2D3, whereas exposure to both cadmium and lead increased the concentrations of 1 alpha,25(OH)2D3. It has been suggested that cadmium and lead interact with renal mitochondrial hydroxylases of the vitamin D3 endocrine complex. Perturbation of the vitamin D metabolic pathway by cadmium may result in health effect, such as osteoporosis or osteomalacia, risks which are possibly increased in the presence of lead.   PMID:9816377

Discovery of Ubiquitous Fast Propagating Intensity Disturbances by the Chromospheric Lyman Alpha Spectropolarimeter (CLASP)

NASA Technical Reports Server (NTRS)

Kubo, M.; Katsukawa, Y.; Suematsu, Y.; Kano, R.; Bando, T.; Narukage, N.; Ishikawa, R.; Hara, H.; Giono, G.; Tsuneta, S.;

Vitamin E in cranes: reference ranges and nutrient interactions

USGS Publications Warehouse

Dierenfeld, Ellen S.; Sheppard, C.D.; Langenberg, J.; Mirande, C.; Spratt, J.; Dein, F.J.

1993-01-01

Fat soluble vitamins E and A (quantified as alpha-tocopherol and all-trans retinol, respectively) were measured in plasma samples from 274 captive cranes from four institutions and five free-ranging birds. Ages ranged from 4 mo to 80 yr, and all 15 crane species were represented. Captive cranes had a mean +/- standard error (SE) of 6.57 +/- 0.82 micrograms/ml alpha-tocopherol; migrating greater sandhill cranes (Grus canadenis tabida) had a plasma concentration of 3.71 +/- 0.22 micrograms/ml. Sex and age differences were not significant, but crane species that evolved in temperate habitats had higher circulating levels of alpha-tocopherol than tropical or subtropical species. Mean +/- SE retinol values were 0.69 +/- 0.05 micrograms/ml in captive cranes, and 0.66 +/- 0.08 micrograms/ml in free-ranging cranes; values did not differ significantly by sex, age, or species. Dietary vitamin E concentrations were significantly correlated with plasma alpha-tocopherol levels in a logarithmic relationship. Dietary selenium at 0.5 mg/kg was associated with decreased circulating alpha-tocopherol concentrations.

Excretion profile of boldenone in urine of veal calves fed two different milk replacers.

PubMed

Draisci, R; Merlanti, R; Ferretti, G; Fantozzi, L; Ferranti, C; Capolongo, F; Segato, S; Montesissa, C

2007-03-14

The residue profiles of 17alpha-/17beta-boldenone conjugated (17alpha/beta-Bol) and ADD were investigated by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in urine of male veal calves fed two commercial milk replacers, with different content of cholesterol and phytosterols. The urine samples were collected within 4 h after feeding and further from all the animals. Detectable amounts of 17alpha-Bol conjugated were measured in urine collected from all calves, but the concentrations of 17alpha-Bol were higher in urine from calves receiving the milk replacer with the greater amount of phytosterols. During the whole experiment, 17beta-Bol and ADD were never detected in urine samples collected.

Markov Dynamics as a Zooming Lens for Multiscale Community Detection: Non Clique-Like Communities and the Field-of-View Limit

PubMed Central

Schaub, Michael T.; Delvenne, Jean-Charles; Yaliraki, Sophia N.; Barahona, Mauricio

2012-01-01

In recent years, there has been a surge of interest in community detection algorithms for complex networks. A variety of computational heuristics, some with a long history, have been proposed for the identification of communities or, alternatively, of good graph partitions. In most cases, the algorithms maximize a particular objective function, thereby finding the ‘right’ split into communities. Although a thorough comparison of algorithms is still lacking, there has been an effort to design benchmarks, i.e., random graph models with known community structure against which algorithms can be evaluated. However, popular community detection methods and benchmarks normally assume an implicit notion of community based on clique-like subgraphs, a form of community structure that is not always characteristic of real networks. Specifically, networks that emerge from geometric constraints can have natural non clique-like substructures with large effective diameters, which can be interpreted as long-range communities. In this work, we show that long-range communities escape detection by popular methods, which are blinded by a restricted ‘field-of-view’ limit, an intrinsic upper scale on the communities they can detect. The field-of-view limit means that long-range communities tend to be overpartitioned. We show how by adopting a dynamical perspective towards community detection [1], [2], in which the evolution of a Markov process on the graph is used as a zooming lens over the structure of the network at all scales, one can detect both clique- or non clique-like communities without imposing an upper scale to the detection. Consequently, the performance of algorithms on inherently low-diameter, clique-like benchmarks may not always be indicative of equally good results in real networks with local, sparser connectivity. We illustrate our ideas with constructive examples and through the analysis of real-world networks from imaging, protein structures and the power grid, where a multiscale structure of non clique-like communities is revealed. PMID:22384178

Detection and Monitoring of Toxic Chemical at Ultra Trace Level by Utilizing Doped Nanomaterial

PubMed Central

Khan, Sher Bahadar; Rahman, Mohammed M.; Akhtar, Kalsoom; Asiri, Abdullah M.

2014-01-01

Composite nanoparticles were synthesized by eco-friendly hydrothermal process and characterized by different spectroscopic techniques. All the spectroscopic techniques suggested the synthesis of well crystalline optically active composite nanoparticles with average diameter of ∼30 nm. The synthesized nanoparticles were applied for the development of chemical sensor which was fabricated by coating the nanoparticles on silver electrode for the recognition of phthalimide using simple I–V technique. The developed sensor exhibited high sensitivity (1.7361 µA.mM−1.cm−2), lower detection limit (8.0 µM) and long range of detection (77.0 µM to 0.38 M). Further the resistances of composite nanoparticles based sensor was found to be 2.7 MΩ which change from 2.7 to 1.7 with change in phthalimide concentration. The major advantages of the designed sensor over existing sensors are its simple technique, low cost, lower detection limit, high sensitivity and long range of detection. It can detect phthalimide even at trace level and sense over wide range of concentrations. Therefore the composite nanoparticals would be a better choice for the fabrication of phthalimide chemical sensor and would be time and cost substituted implement for environmental safety. PMID:25329666

Altered fractal dynamics of gait: reduced stride-interval correlations with aging and Huntington's disease

NASA Technical Reports Server (NTRS)

Hausdorff, J. M.; Mitchell, S. L.; Firtion, R.; Peng, C. K.; Cudkowicz, M. E.; Wei, J. Y.; Goldberger, A. L.

1997-01-01

Fluctuations in the duration of the gait cycle (the stride interval) display fractal dynamics and long-range correlations in healthy young adults. We hypothesized that these stride-interval correlations would be altered by changes in neurological function associated with aging and certain disease states. To test this hypothesis, we compared the stride-interval time series of 1) healthy elderly subjects and young controls and of 2) subjects with Huntington's disease and healthy controls. Using detrended fluctuation analysis we computed alpha, a measure of the degree to which one stride interval is correlated with previous and subsequent intervals over different time scales. The scaling exponent alpha was significantly lower in elderly subjects compared with young subjects (elderly: 0.68 +/- 0.14; young: 0.87 +/- 0.15; P < 0.003). The scaling exponent alpha was also smaller in the subjects with Huntington's disease compared with disease-free controls (Huntington's disease: 0.60 +/- 0.24; controls: 0.88 +/-0.17; P < 0.005). Moreover, alpha was linearly related to degree of functional impairment in subjects with Huntington's disease (r = 0.78, P < 0.0005). These findings demonstrate that strike-interval fluctuations are more random (i.e., less correlated) in elderly subjects and in subjects with Huntington's disease. Abnormal alterations in the fractal properties of gait dynamics are apparently associated with changes in central nervous system control.

Segmentation of time series with long-range fractal correlations

PubMed Central

Bernaola-Galván, P.; Oliver, J.L.; Hackenberg, M.; Coronado, A.V.; Ivanov, P.Ch.; Carpena, P.

2012-01-01

Segmentation is a standard method of data analysis to identify change-points dividing a nonstationary time series into homogeneous segments. However, for long-range fractal correlated series, most of the segmentation techniques detect spurious change-points which are simply due to the heterogeneities induced by the correlations and not to real nonstationarities. To avoid this oversegmentation, we present a segmentation algorithm which takes as a reference for homogeneity, instead of a random i.i.d. series, a correlated series modeled by a fractional noise with the same degree of correlations as the series to be segmented. We apply our algorithm to artificial series with long-range correlations and show that it systematically detects only the change-points produced by real nonstationarities and not those created by the correlations of the signal. Further, we apply the method to the sequence of the long arm of human chromosome 21, which is known to have long-range fractal correlations. We obtain only three segments that clearly correspond to the three regions of different G + C composition revealed by means of a multi-scale wavelet plot. Similar results have been obtained when segmenting all human chromosome sequences, showing the existence of previously unknown huge compositional superstructures in the human genome. PMID:23645997

A Review of the Growth Habits and Restoration Issues for Clitoria fragrans and Polygonella basiramia

DTIC Science & Technology

2007-06-01

ERDC/CRREL TR-07-6 2 Figure 1. Alpha impact area on Avon Park Air Force Range, showing the locations of Clitoria fragrans ( pigeon wing • ) and...herb belonging to the pea family (Fig. 3–5). One of about 35 species in the Clitoria genus (USDA 2007), C. fragrans is limited mainly to the rapidly...chasmogamous flowers have a typical zygomorphic pea family arrangement, with a large 3.5- to 5-cm-long wing petal and a small white keel petal forming a boat

Detection and characterization of a new metabolite of 17alpha-methyltestosterone.

PubMed

Pozo, Oscar J; Van Eenoo, Peter; Deventer, Koen; Lootens, Leen; Van Thuyne, Wim; Parr, Maria K; Schänzer, Wilhelm; Sancho, Juan V; Hernández, Felix; Meuleman, Philip; Leroux-Roels, Geert; Delbeke, Frans T

2009-11-01

The misuse of the anabolic steroid methyltestosterone is currently routinely monitored in doping control laboratories by gas chromatography-mass spectrometry (GC-MS) of two of its metabolites: 17alpha-methyl-5beta-androstane-3alpha,17beta-diol and 17alpha-methyl-5alpha-androstane-3alpha,17beta-diol. Because of the absence of any easy ionizable moiety, these metabolites are poorly detectable using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI). In this study, the metabolism of methyltestosterone has been reinvestigated by the use of a precursor ion scan method in LC-ESI-MS/MS. Two metabolites have been detected using this method. Both compounds have been confirmed in postadministration urine samples of an urokinase plasminogen activator-severe combined immunodeficiency (uPA-SCID) mouse with humanized liver and were characterized by LC-MS/MS and GC-MS using both quadrupole and time of flight analyzers. From the detailed study of the fragmentation, these metabolites were proposed to be epimethyltestosterone and a dehydrogenated compound. Epimethyltestosterone has previously been described as a minor metabolite, whereas the occurrence of the oxidized metabolite has not been reported. Comparison with the synthesized reference revealed that the structure of the dehydrogenated metabolite is 6-ene-epimethyltestosterone. A selected reaction monitoring method including three transitions for each metabolite has been developed and applied to samples from an excretion study and to samples declared positive after GC-MS analysis. 6-Ene-epimethyltestosterone was found in all samples, showing its applicability in the detection of methyltestosterone misuse.

Development of a continuous radon concentration monitoring system in underground soil

NASA Astrophysics Data System (ADS)

Yamamoto, S.; Tarutani, K.; Yamasoto, K.; Iskandar, D.; Iida, T.

2001-06-01

A continuous radon (Rn-222) concentration monitoring system for use in underground soil was developed and tested. The system consists of a 19-mm-diameter, 1100-mm-long detector assembly and a microprocessor based data logger. A small volume chamber is installed at the tip of the detector assembly. A thin ZnS(Ag) scintillator film inside the chamber and a photomultiplier tube (PMT) detect alpha particles from radon and its daughters. When the system is in measurement, the detector part is buried into underground soil. An energy resolution of approximately 70% full width half maximum (FWHM) was obtained for 5.5 MeV alpha particles from Am-241. Both the rise time and fall time for the system were measured to be approximately 1-2 h. Temporal variations in underground radon concentration at different depths were investigated simultaneously using four sets of the developed system. The results confirmed that the developed system is useful for continuous measurement of radon concentration in underground soil.

Search for dark companions of K and M giants - Preliminary results for Alpha Boo

NASA Technical Reports Server (NTRS)

Heyer, I.; Hall, D. N. B.; Hinkle, K.

1987-01-01

Preliminary results are presented for Alpha Boo, encompassing selected measurements during the period from January 1979 to June 1984. Four groups of data are chosen, each group taken within an interval of up to 1.5 months, and examined the internal consistency of each set to look for short term trends. The radial velocity was found to be very consistent with a standard deviation of about + or - 50 m/s within time scales of hours, days, and weeks. No significant radial velocity changes over these periods were detected. This suggests that the stellar surface activity is confined to the level of uncertainty. Because of this consistency it was possible to take the means of the radial velocity measurements within each group and compare them to look for possible long term changes. Variations of the radial velocity of about 200 m/s were found over the span of a few years, significant at the 6 to 8 sigma level.

Antagonism of Lateral Amygdala Alpha1-Adrenergic Receptors Facilitates Fear Conditioning and Long-Term Potentiation

ERIC Educational Resources Information Center

Lazzaro, Stephanie C.; Hou, Mian; Cunha, Catarina; LeDoux, Joseph E.; Cain, Christopher K.

2010-01-01

Norepinephrine receptors have been studied in emotion, memory, and attention. However, the role of alpha1-adrenergic receptors in fear conditioning, a major model of emotional learning, is poorly understood. We examined the effect of terazosin, an alpha1-adrenergic receptor antagonist, on cued fear conditioning. Systemic or intra-lateral amygdala…

Glucosylated free oligosaccharides are biomarkers of endoplasmic- reticulum alpha-glucosidase inhibition.

PubMed

Alonzi, Dominic S; Neville, David C A; Lachmann, Robin H; Dwek, Raymond A; Butters, Terry D

2008-01-15

The inhibition of ER (endoplasmic reticulum) alpha-glucosidases I and II by imino sugars, including NB-DNJ (N-butyl-deoxynojirimycin), causes the retention of glucose residues on N-linked oligosaccharides. Therefore, normal glycoprotein trafficking and processing through the glycosylation pathway is abrogated and glycoproteins are directed to undergo ERAD (ER-associated degradation), a consequence of which is the production of cytosolic FOS (free oligosaccharides). Following treatment with NB-DNJ, FOS were extracted from cells, murine tissues and human plasma and urine. Improved protocols for analysis were developed using ion-exchange chromatography followed by fluorescent labelling with 2-AA (2-aminobenzoic acid) and purification by lectin-affinity chromatography. Separation of 2-AA-labelled FOS by HPLC provided a rapid and sensitive method that enabled the detection of all FOS species resulting from the degradation of glycoproteins exported from the ER. The generation of oligosaccharides derived from glucosylated protein degradation was rapid, reversible, and time- and inhibitor concentration-dependent in cultured cells and in vivo. Long-term inhibition in cultured cells and in vivo indicated a slow rate of clearance of glucosylated FOS. In mouse and human urine, glucosylated FOS were detected as a result of transrenal excretion and provide unique and quantifiable biomarkers of ER-glucosidase inhibition.

Method for detecting the presence of prostate cancer

DOEpatents

Karin, Michael; Luo, Jun-Li; Tan, Wei

2010-04-13

The present invention relates to compositions and methods for cancer diagnosis, treatment and drug screening. In particular, the present invention provides compositions and methods for targeting the nuclear translocation of IkB kinase-.alpha. (IKK.alpha.) and the IKK.alpha.-mediated suppression of Maspin expression observed in metastatic prostate cancer cells.

Transcriptional Response of Human Cells to Microbeam Irradiation with 2.1 MeV Alpha Particles

NASA Astrophysics Data System (ADS)

Hellweg, C. E.; Bogner, S.; Spitta, L.; Arenz, A.; Baumstark-Khan, C.; Greif, K. D.; Giesen, U.

Within the next decades an increasing number of human beings in space will be simultaneously exposed to different stimuli especially microgravity and radiation To assess the risks for humans during long-duration space missions the complex interplay of these parameters at the cellular level must be understood Cellular stress protection responses lead to increased transcription of several genes via modulation of transcription factors Activation of the Nuclear Factor kappa B NF- kappa B pathway as a possible anti-apoptotic route represents such an important cellular stress response A screening assay for detection of NF- kappa B-dependent gene activation using the destabilized variant of Enhanced Green Fluorescent Protein d2EGFP as reporter protein had been developed It consists of Human Embryonic Kidney HEK 293 Cells stably transfected with a receptor-reporter-construct carrying d2EGFP under the control of a NF- kappa B response element Clones positive for Tumor Necrosis Factor alpha TNF- alpha inducible d2EGFP expression were selected as cellular reporters Irradiation was performed either with X-rays 150 kV 19 mA at DLR Cologne or with 2 1 MeV alpha particles LET sim 160 keV mu m at PTB Braunschweig After irradiation the following biological endpoints were determined i cell survival via the colony forming ability test ii time-dependent activation of NF- kappa B dependent d2EGFP gene expression using flow cytometry iii quantitative RT-PCR

First Results from Faint Infrared Grism Survey (Figs): First Simultaneous Detection of Ly Alpha Emission and Lyman Break From a Galaxy at Z =7.51

NASA Technical Reports Server (NTRS)

Tilvi, V.; Pirzkal, N.; Malhotra, S.; Finkelstein, S. L.; Rhoads, J. E.; Windhorst, R.; Grogin, N. A.; Koekemoer, A.; Zakamska, N. L.; Ryan, R.;

Hypoxia preconditioning protection of corneal stromal cells requires HIF1alpha but not VEGF.

PubMed

Xing, Dongmei; Bonanno, Joseph A

2009-05-18

Hypoxia preconditioning protects corneal stromal cells from stress-induced death. This study determined whether the transcription factor HIF-1alpha (Hypoxia Inducible Factor) is responsible and whether this is promulgated by VEGF (Vascular Endothelial Growth Factor). Cultured bovine stromal cells were preconditioned with hypoxia in the presence of cadmium chloride, a chemical inhibitor of HIF-1alpha, and HIF-1alpha siRNA to test if HIF-1alpha activity is needed for hypoxia preconditioning protection from UV-irradiation induced cell death. TUNEL assay was used to detect cell apoptosis after UV-irradiation. RT-PCR and western blot were used to detect the presence of HIF-1alpha and VEGF in transcriptional and translational levels. During hypoxia (0.5% O2), 5 muM cadmium chloride completely inhibited HIF-1alpha expression and reversed the protection by hypoxia preconditioning. HIF-1alpha siRNA (15 nM) reduced HIF-1alpha expression by 90% and produced a complete loss of protection provided by hypoxia preconditioning. Since VEGF is induced by hypoxia, can be HIF-1alpha dependent, and is often protective, we examined the changes in transcription of VEGF and its receptors after 4 h of hypoxia preconditioning. VEGF and its receptors Flt-1 and Flk-1 are up-regulated after hypoxia preconditioning. However, the transcription and translation of VEGF were paradoxically increased by siHIF-1alpha, suggesting that VEGF expression in stromal cells is not down-stream of HIF-1alpha. These findings demonstrate that hypoxia preconditioning protection in corneal stromal cells requires HIF-1alpha, but that VEGF is not a component of the protection.

Nicotinic Receptor Alpha7 Expression during Tooth Morphogenesis Reveals Functional Pleiotropy

PubMed Central

Rogers, Scott W.; Gahring, Lorise C.

2012-01-01

The expression of nicotinic acetylcholine receptor (nAChR) subtype, alpha7, was investigated in the developing teeth of mice that were modified through homologous recombination to express a bi-cistronic IRES-driven tau-enhanced green fluorescent protein (GFP); alpha7GFP) or IRES-Cre (alpha7Cre). The expression of alpha7GFP was detected first in cells of the condensing mesenchyme at embryonic (E) day E13.5 where it intensifies through E14.5. This expression ends abruptly at E15.5, but was again observed in ameloblasts of incisors at E16.5 or molar ameloblasts by E17.5–E18.5. This expression remains detectable until molar enamel deposition is completed or throughout life as in the constantly erupting mouse incisors. The expression of alpha7GFP also identifies all stages of innervation of the tooth organ. Ablation of the alpha7-cell lineage using a conditional alpha7Cre×ROSA26-LoxP(diphtheria toxin A) strategy substantially reduced the mesenchyme and this corresponded with excessive epithelium overgrowth consistent with an instructive role by these cells during ectoderm patterning. However, alpha7knock-out (KO) mice exhibited normal tooth size and shape indicating that under normal conditions alpha7 expression is dispensable to this process. The function of ameloblasts in alpha7KO mice is altered relative to controls. High resolution micro-computed tomography analysis of adult mandibular incisors revealed enamel volume of the alpha7KO was significantly reduced and the organization of enamel rods was altered relative to controls. These results demonstrate distinct and varied spatiotemporal expression of alpha7 during tooth development, and they suggest that dysfunction of this receptor would have diverse impacts upon the adult organ. PMID:22666322

Development and irradiation test of lost alpha detection system for ITER.

PubMed

Nishiura, M; Nagasaka, T; Fujioka, K; Fujimoto, Y; Tanaka, T; Ido, T; Yamamoto, S; Kashiwa, S; Sasao, M

2010-10-01

We developed a lost alpha detection system to use in burning plasma experiments. The scintillators of Ag:ZnS and polycrystalline Ce:YAG were designed for a high-temperature environment, and the optical transmission line was designed to transmit from the scintillator to the port plug. The required optical components of lenses and mirrors were irradiated using the fission reactor with the initial result that there was no clear change after the irradiation with a neutron flux of 9.6×10(17) nm(-2)  s(-1) for 48 h. We propose a diagnostic of alpha particle loss, so-called alpha particle induced gamma ray spectroscopy. The initial laboratory test has been carried out by the use of the Ce doped Lu(2)SiO(5) scintillator detector and an Am-Be source to detect the 4.44 MeV high energy gamma ray due to the (9)Be(α,nγ)(12)C reaction.

Modeling forest biomass and growth: Coupling long-term inventory and LiDAR data

Treesearch

Chad Babcock; Andrew O. Finley; Bruce D. Cook; Aaron Weiskittel; Christopher W. Woodall

2016-01-01

Combining spatially-explicit long-term forest inventory and remotely sensed information from Light Detection and Ranging (LiDAR) datasets through statistical models can be a powerful tool for predicting and mapping above-ground biomass (AGB) at a range of geographic scales. We present and examine a novel modeling approach to improve prediction of AGB and estimate AGB...

Rapid, automated, parallel quantitative immunoassays using highly integrated microfluidics and AlphaLISA

PubMed Central

Tak For Yu, Zeta; Guan, Huijiao; Ki Cheung, Mei; McHugh, Walker M.; Cornell, Timothy T.; Shanley, Thomas P.; Kurabayashi, Katsuo; Fu, Jianping

2015-01-01

Immunoassays represent one of the most popular analytical methods for detection and quantification of biomolecules. However, conventional immunoassays such as ELISA and flow cytometry, even though providing high sensitivity and specificity and multiplexing capability, can be labor-intensive and prone to human error, making them unsuitable for standardized clinical diagnoses. Using a commercialized no-wash, homogeneous immunoassay technology (‘AlphaLISA’) in conjunction with integrated microfluidics, herein we developed a microfluidic immunoassay chip capable of rapid, automated, parallel immunoassays of microliter quantities of samples. Operation of the microfluidic immunoassay chip entailed rapid mixing and conjugation of AlphaLISA components with target analytes before quantitative imaging for analyte detections in up to eight samples simultaneously. Aspects such as fluid handling and operation, surface passivation, imaging uniformity, and detection sensitivity of the microfluidic immunoassay chip using AlphaLISA were investigated. The microfluidic immunoassay chip could detect one target analyte simultaneously for up to eight samples in 45 min with a limit of detection down to 10 pg mL−1. The microfluidic immunoassay chip was further utilized for functional immunophenotyping to examine cytokine secretion from human immune cells stimulated ex vivo. Together, the microfluidic immunoassay chip provides a promising high-throughput, high-content platform for rapid, automated, parallel quantitative immunosensing applications. PMID:26074253

A SURVEY OF METAL LINES AT HIGH-REDSHIFT. I. SDSS ABSORPTION LINE STUDIES- THE METHODOLOGY AND FIRST SEARCH RESULTS FOR O VI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frank, S.; Mathur, S.; Pieri, M.

2010-09-15

We report the results of a systematic search for signatures of metal lines in quasar spectra of the Sloan Digital Sky Survey (SDSS) data release 3 (DR3), focusing on finding intervening absorbers via detection of their O VI doublet. Here, we present the search algorithm and criteria for distinguishing candidates from spurious Ly{alpha} forest lines. In addition, we compare our findings with simulations of the Ly{alpha} forest in order to estimate the detectability of O VI doublets over various redshift intervals. We have obtained a sample of 1756 O VI doublet candidates with rest-frame equivalent width (EW) {>=}0.05 A inmore » 855 active galactic nuclei spectra (out of 3702 objects with redshifts in the accessible range for O VI detection). This sample is further subdivided into three groups according to the likelihood of being real and the potential for follow-up observation of the candidate. The group with the cleanest and most secure candidates is comprised of 145 candidates. Sixty-nine of these reside at a velocity separation {>=}5000 km s{sup -1} from the QSO and can therefore be classified tentatively as intervening absorbers. Most of these absorbers have not been picked up by earlier, automated QSO absorption line detection algorithms. This sample increases the number of known O VI absorbers at redshifts beyond z{sub abs{>=}} 2.7 substantially.« less

The effect of Bobath approach on the excitability of the spinal alpha motor neurones in stroke patients with muscle spasticity.

PubMed

Ansari, N N; Naghdi, S

2007-01-01

A clinical study was performed to evaluate the efficacy of the Bobath approach on the excitability of the spinal alpha motor neurones in patients with poststroke spasticity. Ten subjects ranging in age from 37 through 76 years (average 60 years) with ankle plantarflexor spasticity secondary to a stroke were recruited and completed the trial. They had physiotherapy according to Bobath concept for ten treatment sessions, three days per week. Two repeated measures, one before and another after treatment, were taken to quantify clinical efficacy. The effect of this type of therapy on the excitability of alpha motor neurones (aMN) was assessed by measuring the latency of the Hoffmann reflex (H-reflex) and the Hmax/Mmax ratio. The original Ashworth scale and ankle range of motion were also measured. The mean HmaxlMmax ratio on the affected side at baseline was high in the study patients. However, there were no statistically significant differences in the HmaxlMmax ratio or in the H-reflex latency between the baseline values and those recorded after therapy intervention. Before treatment, the HmaxlMmax ratio was significantly higher in the affected side than in the unaffected side. However, it was similar at both sides after treatment. Following treatment, the significant reduction in spasticity was clinically detected as measured with the original Ashworth scale. The ankle joint active and passive range of motion was significantly increased. In conclusion, Bobath therapy had a statistically significant effect on the excitability of the aMN in the affected side compared to the unaffected side in stroke patients with muscle spasticity.

In utero exposure to low doses of bisphenol A lead to long-term deleterious effects in the vagina.

PubMed

Schönfelder, G; Flick, B; Mayr, E; Talsness, C; Paul, M; Chahoud, I

2002-01-01

The origins of the "endocrine disrupter hypothesis" may be traced to reports on adolescent daughters born to women who had taken the highly potent synthetic estrogen, diethylstilbestrol, while pregnant, and who developed a rare form of vaginal cancer and adenocarcinoma. Bisphenol A (BPA) is an estrogenic chemical that is highly employed in the manufacture of a wide range of consumer products. Some observational studies have suggested that the amounts of BPA to which we are exposed could alter the reproductive organs of developing rodents. We examined the influence of BPA at low doses to address the questions of (a) whether in utero exposure affects the vagina of the offspring and (b) which mechanisms cause the toxic effects. Gravid Sprague-Dawley dams were administered either 0.1 (low dose) or 50 mg/kg per day BPA, the no observed effect level, or 0.2 mg/kg per day 17 alpha-ethinyl estradiol by gavage. Striking morphological changes were observed in the vagina of postpubertal offspring leading us to examine vaginal estrogen receptor (ER) expression because BPA binds to the ER alpha, which is important for growth of the vaginal epithelium. We show that the full-length ER alpha is not expressed during estrus in the vagina of female offspring exposed to either dose of BPA when compared to the control group, whereas ER alpha expression does not differ from the control group during the diestrus stage. ER alpha downregulation seems to be responsible for the observed altered vaginal morphology.

Determination of the volume activity concentration of alpha artificial radionuclides with alpha spectrometer.

PubMed

Liu, B; Zhang, Q; Li, Y

1997-12-01

This paper introduces a method to determine the volume activity concentration of alpha and/or beta artificial radionuclides in the environment and radon/thoron progeny background-compensation based on a Si surface-barrier detector. By measuring the alpha peak counts of 218Po and 214Po in two time intervals, the activity concentration of 218Po, 214Pb and 214Bi aerosol particles were determined; meanwhile, the total beta count of 214Pb and 214Bi aerosols was also calculated from their decay scheme. With the average equilibrium factor of thoron progeny in general environment, the alpha and beta counts of thoron progeny were approximately evaluated by 212Po alpha peak counts. The alpha count of transuranic aerosols was determined by subtracting the trail counts of radon/thoron progeny alpha peaks. The total count of beta artificial radionuclides was determined by subtracting the beta counts of radon/thoron progeny aerosol particles. In our preliminary experiments, if the radon progeny concentration is less than 15 Bq m(-3), the lower limit of detection of transuranics concentration is less than 0.1 Bq m(-3). Even if the radon progeny concentration is as high as 75 Bq m(-3), the lower limit of detection of total beta activity concentration of artificial nuclides aerosols is less than 1 Bq m(-3).

Studies on in-vessel debris coolability in ALPHA program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maruyama, Yu; Yamano, Norihiro; Moriyama, Kiyofumi

1997-02-01

In-vessel debris coolability experiments have been performed in ALPHA Program at JAERI. Aluminum oxide (Al{sub 2}O{sub 3}) produced by a thermite reaction was applied as a debris simulant. Two scoping experiments using approximately 30 kg or 50 kg of Al{sub 2}O{sub 3} were conducted. In addition to post-test observations, temperature histories of the debris simulant and the lower head experimental vessel were evaluated. Rapid temperature reduction observed on the outer surface of the experimental vessel may imply that water penetration into a gap between the solidified debris and the experimental vessel occurred resulting in an effective cooling of once heatedmore » vessel wall. Preliminary measurement of a gap width was made with an ultrasonic device. Signals to show the existence of gaps, ranging from 0.7 mm to 1.4 mm, were detected at several locations.« less

Fourth International Symposium on Long-Range Sound Propagation

NASA Technical Reports Server (NTRS)

Willshire, William L., Jr. (Compiler)

1990-01-01

Long range sound propagation is an aspect of many acoustical problems ranging from en route aircraft noise to the acoustic detection of aircraft. Over the past decade, the University of Mississippi and the Open University of England, together with a third institution, have held a symposium approx. every 2 years so that experts in the field of long range propagation could exchange information on current research, identify areas needing additional work, and coordinate activities as much as possible. The Fourth International Symposium on Long Range Sound Propagation was jointly sponsored by the University of Mississippi, the Open University of England, and NASA. Papers were given in the following areas: ground effects on propagation; infrasound propagation; and meteorological effects on sound propagation. A compilation of the presentations made at the symposium is presented along with a list of attendees, and the agenda.

Monitoring materials

DOEpatents

Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore

2002-01-01

The apparatus and method provide techniques for effectively implementing alpha and/or beta and/or gamma monitoring of items or locations as desired. Indirect alpha monitoring by detecting ions generated by alpha emissions, in conjunction with beta and/or gamma monitoring is provided. The invention additionally provides for screening of items prior to alpha monitoring using beta and/or gamma monitoring, so as to ensure that the alpha monitoring apparatus is not contaminated by proceeding direct to alpha monitoring of a heavily contaminated item or location. The invention provides additional versatility in the emission forms which can be monitored, whilst maintaining accuracy and avoiding inadvertent contamination.

The deep structure of Venusian plateau highlands

NASA Technical Reports Server (NTRS)

Grimm, Robert E.

1994-01-01

Magellan gravity data confirm that several of the large, tectonically deformed, plateau-like highlands on venus are shallowly compensated, most likely by crustal thickness variations. Apparent depths of isostatic compensation, computed in the spatial domain, range from 30 to 50 km for Alpha, Tellus, Ovda, and Thetis Regiones. Using a two-layer model for isostatic compensation, Alpha, Tellus, and Ovda are best represented as nearly completely compensated in crust that is regionally 20-40 km thick around these highlands, with little contribution from deeper mantle sources. In contrast to these three areas, a stronger regional gravity high associated with Thetis requires a significant upper mantle component to compensation. This is evident in the spectral admittance as a pronounced deep, long-wavelength anomaly. In the two-layer isostatic model, a broad, deeply compensated upland underlies a shallowly compensated central block of Thetis. If this deep component is interpreted as a thermal anomaly, the loci of maximum upwelling agree well with sites of recent extension. The plateau highlands are thus physiographically and isostatically equivalent to terrestrial continents, though probably not compositionally. They also share the record of a long tectonic history. The large regional gravity anomaly of Thetis indicates that active mantle proceses continue even beneath some areas (tessera) thought to be a relic of a former geological regime. The excellent agreement of modeled crustal thicknesses around Alpha, Tellus, and Ovda Regiones suggests that 20-40 km is a representative global value for the plains. Such a crust is thicker than previously estimated and about twice as thick as the expected thickness of crust produced at venusian spreading centers

Molecular and functional analyses of the contractile apparatus in lymphatic muscle

NASA Technical Reports Server (NTRS)

Muthuchamy, Mariappan; Gashev, Anatoliy; Boswell, Niven; Dawson, Nancy; Zawieja, David; Delp, Z. (Principal Investigator)

2003-01-01

Lymphatics are necessary for the generation and regulation of lymph flow. Lymphatics use phasic contractions and extrinsic compressions to generate flow; tonic contractions alter resistance. Lymphatic muscle exhibits important differences from typical vascular smooth muscle. In this study, the thoracic duct exhibited significant functional differences from mesenteric lymphatics. To understand the molecular basis for these differences, we examined the profiles of contractile proteins and their messages in mesenteric lymphatics, thoracic duct, and arterioles. Results demonstrated that mesenteric lymphatics express only SMB smooth muscle myosin heavy chain (SM-MHC), whereas thoracic duct and arterioles expressed both SMA and SMB isoforms. Both SM1 and SM2 isoforms of SM-MHC were detected in arterioles and mesenteric and thoracic lymphatics. In addition, the fetal cardiac/skeletal slow-twitch muscle-specific beta-MHC message was detected only in mesenteric lymphatics. All four actin messages, cardiac alpha-actin, vascular alpha-actin, enteric gamma-actin, and skeletal alpha-actin, were present in both mesenteric lymphatics and arterioles. However, in thoracic duct, predominantly cardiac alpha-actin and vascular alpha-actin were found. Western blot and immunohistochemical analyses corroborated the mRNA studies. However, in arterioles only vascular alpha-actin protein was detected. These data indicate that lymphatics display genotypic and phenotypic characteristics of vascular, cardiac, and visceral myocytes, which are needed to fulfill the unique roles of the lymphatic system.

Concentration of carotenoids, retinol and alpha-tocopherol in plasma of six microchiroptera species.

PubMed

Müller, Kerstin; Voigt, Christian C; Raila, Jens; Hurtienne, Andrea; Vater, Marianne; Brunnberg, Leo; Schweigert, Florian J

2007-07-01

To adequately feed species in captivity it is necessary to know their nutritional habits and their natural availability of specific nutrients. Such essential nutrients are vitamin A, vitamin E and selected carotenoids as vitamin-A-precursors. Because their blood plasma concentration are valid biomarkers of nutritional status of dietary intake, we determined the concentrations of carotenoids, retinol and alpha-tocopherol by HPLC as well as the transport proteins for retinol, the retinol-binding protein (RBP) and transthyretin (TTR) immunologically in the plasma of six species of microchiroptera from free-ranging animals and compared it in one species (Carollia perspicillata) to a group held in captivity. Plasma concentrations of the investigated components were generally much lower compared to most other mammals. Within the bats, differences were observed for all components. As in other species retinol, RBP and TTR were present but no retinyl esters could be detected. Plasma of the insectivorous bat species Molossus molossus contained carotenoids. Within the group of carotenoids, beta-carotene was dominant and only traces of lutein were present. Phyllostomus hastatus revealed the highest alpha-tocopherol concentration. No differences in the plasma content of the investigated compounds were found between a group of Carollia perspicillata kept in captivity for 20 years and free-ranging individuals from a population in Central America. No sex related differences were obvious. In conclusion, nutritional biomarkers in bats were highly variable due to dietary and possible species-specific differences.

Quartz Crystal Microbalance: Aerosol Viscoelastic Measurement Calibration and Subsiquent H2O Uptake

NASA Astrophysics Data System (ADS)

Farland, D. R., Jr.; Gilles, M. K.; Harder, T.; Weis, J.; Mueller, S.

2015-12-01

Aerosol particles exposed to various atmospheric relative humidity (RH) levels exhibit hygroscopic properties which are not fully understood. Water adsorption or diffusion depends on particle viscosity in semi-solid to liquid states. This relationship between particle viscosity as a function of RH and the corresponding hygroscopic behavioral response is the purpose of this study. However, reliable techniques for viscosity quantification have been limited. A Quartz Crystal Microbalance with Dissipation (QCM-D) was used for viscosity measurements and to determine phase changes. Prior to studies on field samples, microscope immersion/viscosity standard oils, salt crystals, sugars and alpha-pinene secondary organic aerosol (SOA) surrogates are used for viscosity, RH calibrations, water uptake and phase change measurements. RH was controlled by flowing N2 gas saturated with H2O for RH's between 0-75% RH. For higher RH values, (75-100% RH range) saturated salt solutions were flowed over a gore membrane to protect the QCM sensor from direct contact with the solutions. The viscosity calibration constructed via QTools fitting software illustrates the limitations as well as the ranges of reliability of the QCM viscosity measurements. Deliquescing salt crystals of differing deliquescence relative humidity's (DRH), sugars and alpha-pinene SOA's provided insight into the detection of various phase change behaviors. Water uptake experiments performed on alpha-pinene SOA and sucrose sugar yielded significantly different frequency and dissipation responses than the deliquescing salts. Future work will apply these experimental methods and analysis on aerosol particles collected during the GoAmazon field campaign.

Characterization of antibodies that selectively detect alpha-synuclein in pathological inclusions.

PubMed

Waxman, Elisa A; Duda, John E; Giasson, Benoit I

2008-07-01

Sensitive detection of alpha-synuclein (alpha-syn) pathology is important in the diagnosis of disorders like Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy and in providing better insights into the etiology of these diseases. Several monoclonal antibodies that selectively react with aggregated alpha-syn in pathological inclusions and reveal extensive and underappreciated alpha-syn pathology in the brains of diseased patients were previously reported by Duda et al. (Ann Neurol 52:205-210, 2002). We sought to characterize the specificity of some of these antibodies (Syn 505, Syn 506 and Syn 514); using C-terminal and N-terminal truncations of alpha-syn, all three antibodies were determined to require N-terminal epitopes that minimally comprise amino acids 2-4, but possibly extend to amino acid 12 of alpha-syn. The selectivity of these antibodies was further assessed using biochemical analysis of human brains and reactivity to altered recombinant alpha-syn proteins with duplication variants of amino acids 1-12. In addition, by expressing wild-type or a double mutant (E46K/A53T) of alpha-syn in cultured cells and by comparing their immunoreactivities to another antibody (SNL-4), which has a similar primary epitope, it was determined that Syn 505, Syn 506 and Syn 514 recognize conformational variants of alpha-syn that is enhanced by the presence of the double mutations. These studies indicate that antibodies Syn 505, Syn 506 and Syn 514 preferentially recognize N-terminal epitopes in complex conformations, consistent with the dramatic conformational change associated with the polymerization of alpha-synuclein into amyloid fibrils that form pathological inclusions.

Development of an alpha scattering instrument for heavy element detection in surface materials

NASA Technical Reports Server (NTRS)

Turkevich, A. L.; Economou, T.; Blume, E.; Anderson, W.

1974-01-01

The development and characteristics of a portable instrument for detecting and measuring the amounts of lead in painted surfaces are discussed. The instrument is based on the ones used with the alpha scattering experiment on the Surveyor lunar missions. The principles underlying the instrument are described. It is stated that the performance tests of the instrument were satisfactory.

[Effect of long-term application of nitrogen fertilizer on the diversity of nitrifying genes (amoA and hao) in paddy soil].

PubMed

Chen, Chun-lan; Wu, Min-na; Wei, Wen-xue

2011-05-01

The aim of this study was to determine the effect of long-term (16 years) application of nitrogen fertilizer on the diversity of nitrifying genes (amoA and hao) in paddy soil on the basis of long-term paddy field experimental station (started in 1990) located in Taoyuan, with the molecular approaches of PCR, constructing libraries and sequencing. The fertilizer was urea and no fertilizer was as control. The Shannon index showed that long-term application of nitrogen fertilizer made the diversity of amoA gene descend while no effect on the diversity of hao gene. The LIBSHUFF statistical analyses demonstrated that both amoA and hao libraries of CK and N treatments were significantly different from each other and the rarefaction curves of libraries failed to meet the plateaus indicating that there were lots kinds of genes haven't been detected. The results of blasting with GenBank and the phylogenetic tree showed that the amoA genes detected in our study had a similarity with the uncultured gene of amoA, which showed some similar to Nitrosospira. Otherwise, the hao genes cloned showed a relationship to the genes of cultured bacteria such as Silicibacteria, Nitrosospira and Methylococcus, and the hao genes found in the N treatment dominated in alpha-Proteobacteria. These results suggest that long-term fertilization of nitrogen had significant impacts on the diversity or community of amoA and hao genes.

Blood and tissue tocopherol levels in rats following intraperitoneally administered alpha-tocopheryl acetate.

PubMed

McGee, C D; Greenwood, C E; Jeejeebhoy, K N

1990-01-01

The correction or maintenance of blood and tissue alpha-tocopherol (alpha-Toc) levels by intraperitoneally administered all-rac-alpha-tocopheryl acetate (alpha-Tac) was compared with RRR- alpha-tocopherol (alpha-Toc) in vitamin E-depleted and control rats. Rats received 1.3 TE vitamin E daily for 7 days. alpha-Tac was detected in plasma of one-third of alpha-Tac-treated rats 24 hr after the first treatment, although not in subsequent samplings. Both alpha-Tac and alpha-Toc increased tocopherol levels in plasma and liver of E-deprived rats, while little or no change was observed in adipose tissue and brain. Similarly, control rats treated with alpha-Tac or alpha-Toc had significantly greater (p less than 0.05) plasma and liver alpha-Toc levels at day 3 and day 7 than did saline-treated rats. There was no significant difference in adipose alpha-Toc levels among treatment groups of control rats. The results of this study suggest that alpha-Tac is rapidly hydrolyzed to its biologically active alcohol form and results in similar effects to that of intraperitoneally administered alpha-Toc.

Fusion of Scores in a Detection Context Based on Alpha Integration.

PubMed

Soriano, Antonio; Vergara, Luis; Ahmed, Bouziane; Salazar, Addisson

2015-09-01

We present a new method for fusing scores corresponding to different detectors (two-hypotheses case). It is based on alpha integration, which we have adapted to the detection context. Three optimization methods are presented: least mean square error, maximization of the area under the ROC curve, and minimization of the probability of error. Gradient algorithms are proposed for the three methods. Different experiments with simulated and real data are included. Simulated data consider the two-detector case to illustrate the factors influencing alpha integration and demonstrate the improvements obtained by score fusion with respect to individual detector performance. Two real data cases have been considered. In the first, multimodal biometric data have been processed. This case is representative of scenarios in which the probability of detection is to be maximized for a given probability of false alarm. The second case is the automatic analysis of electroencephalogram and electrocardiogram records with the aim of reproducing the medical expert detections of arousal during sleeping. This case is representative of scenarios in which probability of error is to be minimized. The general superior performance of alpha integration verifies the interest of optimizing the fusing parameters.

alpha-Tubulin of Histriculus cavicola (Ciliophora; Hypotrichea).

PubMed

Pérez-Romero, P; Villalobo, E; Díaz-Ramos, C; Calvo, P; Santos-Rosa, F; Torres, A

1997-03-01

An alpha-tubulin gene fragment amplified by PCR from the hypotrichous ciliate Histriculus cavicola has been sequenced. This fragment, 1,182 bp long, contains an in-frame "stop" codon (UAA), which in other hypotrichous species codes for a glutamine residue. The comparison of the alpha-tubulin genes from several ciliates classes have revealed amino acid positions which could serve to distinguish these taxonomic groups.

Alpha-dispersion in human tissue

NASA Astrophysics Data System (ADS)

Grimnes, Sverre; Martinsen, Ørjan G.

2010-04-01

Beta dispersion is found in living tissue in the kilohertz - megahertz range and is caused by the cellular structure of biological materials with low frequency properties caused by cell membranes. Alpha dispersion is found in the hertz range and the causes are not so well known. Alpha dispersions are the first to disappear when tissue dies. Tissue data have often been based upon excised specimen from animals and are therefore not necessarily representative for human tissue alpha dispersions. Here we present data obtained with non-invasive skin surface electrodes for different segments of the living human body. We found alpha dispersions in all cases; the ankle-wrist results had the smallest. Large alpha dispersions were found where the distance between the electrodes and muscle masses was small, e.g. on the calf. Further studies on electrode technique and reciprocity, electrode positioning, statistical variations, gender, age and bodily constitutions are necessary in order to reveal more about the alpha dispersion, its appearance and disappearance.

2J, 3J-HMBC: A New Long-Range Heteronuclear Shift Correlation Technique Capable of Differentiating 2JCH from 3JCH Correlations to Protonated Carbons

NASA Astrophysics Data System (ADS)

Krishnamurthy, V. V.; Russell, David J.; Hadden, Chad E.; Martin, Gary E.

2000-09-01

The development of a series of new, accordion-optimized long-range heteronuclear shift correlation techniques has been reported. A further derivative of the constant time variable delay introduced in the IMPEACH-MBC experiment, a STAR (Selectively Tailored Accordion F1 Refocusing) operator is described in the present report. Incorporation of the STAR operator with the capability of user-selected homonuclear modulation scaling as in the CIGAR-HMBC experiment, into a long-range heteronuclear shift correlation pulse sequence, 2J,3J-HMBC, affords for the first time in a proton-detected experiment the means of unequivocally differentiating two-bond (2JCH) from three-bond (3JCH) long-range correlations to protonated carbons.

Analysis of fragrance compounds in blood samples of mice by gas chromatography, mass spectrometry, GC/FTIR and GC/AES after inhalation of sandalwood oil.

PubMed

Jirovetz, L; Buchbauer, G; Jäger, W; Woidich, A; Nikiforov, A

1992-01-01

After inhalation experiments with sandalwood oil and the pure fragrance compounds coumarin and alpha-terpineol, substances were detected and measured in the blood samples of test animals (mice) using gas chromatography/mass spectrometry (GC/MS) (MID) in connection with GC/FTIR (SWC), GC/AES (carbon and oxygen trace) and flame ionization detection/gas chromatography. Using tiglinic acid benzyl ester as the internal standard the following concentrations in serum could be found: alpha-santalol 6.1 ng/mL, beta-santalol 5.3 ng/mL and alpha-santalene 0.5 ng/mL. In separate inhalation experiments with coumarin and with alpha-terpineol the corresponding concentrations were 7.7 ng/mL and 6.9 ng/mL, respectively.

Quantitative measurement of intact alpha-synuclein proteoforms from post-mortem control and Parkinson's disease brain tissue by intact protein mass spectrometry.

PubMed

Kellie, John F; Higgs, Richard E; Ryder, John W; Major, Anthony; Beach, Thomas G; Adler, Charles H; Merchant, Kalpana; Knierman, Michael D

2014-07-23

A robust top down proteomics method is presented for profiling alpha-synuclein species from autopsied human frontal cortex brain tissue from Parkinson's cases and controls. The method was used to test the hypothesis that pathology associated brain tissue will have a different profile of post-translationally modified alpha-synuclein than the control samples. Validation of the sample processing steps, mass spectrometry based measurements, and data processing steps were performed. The intact protein quantitation method features extraction and integration of m/z data from each charge state of a detected alpha-synuclein species and fitting of the data to a simple linear model which accounts for concentration and charge state variability. The quantitation method was validated with serial dilutions of intact protein standards. Using the method on the human brain samples, several previously unreported modifications in alpha-synuclein were identified. Low levels of phosphorylated alpha synuclein were detected in brain tissue fractions enriched for Lewy body pathology and were marginally significant between PD cases and controls (p = 0.03).

Systems and methods for neutron detection using scintillator nano-materials

DOEpatents

Letant, Sonia Edith; Wang, Tzu-Fang

2016-03-08

In one embodiment, a neutron detector includes a three dimensional matrix, having nanocomposite materials and a substantially transparent film material for suspending the nanocomposite materials, a detector coupled to the three dimensional matrix adapted for detecting a change in the nanocomposite materials, and an analyzer coupled to the detector adapted for analyzing the change detected by the detector. In another embodiment, a method for detecting neutrons includes receiving radiation from a source, converting neutrons in the radiation into alpha particles using converter material, converting the alpha particles into photons using quantum dot emitters, detecting the photons, and analyzing the photons to determine neutrons in the radiation.

Formation of ferric oxides from aqueous solutions: A polyhedral approach by X-ray absorption spectroscopy. I. Hydrolysis and formation of ferric gels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Combes, J.M.; Manceau, A.; Calas, G.

1989-03-01

X-ray absorption spectroscopy (XAS) was used to follow the evolution of local structural environments around ferric ions during the formation of ferric hydrous oxide gels from 1 M chloride and 0.1 M nitrate solutions. Fe K-XANES and EXAFS confirm that ferric ions remain 6-fold coordinated during this evolution. With increasing OH availability in the solution, Cl{sup {minus}} anions tend gradually to be exchanged for (O, OH, OH{sub 2}) ligands. Below OH/Fe = 1, no structural order is detected beyond the first coordination sphere. Above this ratio, two Fe-Fe distances at 3.05 {angstrom} and 3.44 {angstrom} are observed and correspond tomore » the presence of edge- and vertex-sharing Fe-octahedra. XAS results show that ferric gels and highly polymerized aqueous species are short-range ordered. The main contribution to disorder in the gels arises from the small size of coherently scattering domains also responsible for their X-ray amorphous character. From the initial to the final stage of hydrolysis, particles possess a nearly spherical shape with a minimum average diameter ranging from 10-30 {angstrom} for polymers formed from chloride and nitrate solutions. As polymerization proceeds, the local order extends to several tens of angstroms and the particle structures becomes progressively closer to that of akaganeite ({beta}-FeOOH) or goethite ({alpha}-FeOOH). This local structure is distinct from that of the lepidocrocite ({gamma}-FeOOH)-like structure of ferric gels precipitated after oxidation of divalent Fe solutions. The growth of the crystalline Fe-oxyhydroxides from gels takes place by the progressive long-range ordering in the ferric polymers without modifying the short-range order around Fe.« less

Diagnostic performance of alpha-fetoprotein, lens culinaris agglutinin-reactive alpha-fetoprotein, des-gamma carboxyprothrombin, and glypican-3 for the detection of hepatocellular carcinoma: a systematic review and meta-analysis protocol

PubMed Central

2013-01-01

Background Diagnosis of early-stage hepatocellular carcinoma (HCC) followed by curative resection or liver transplantation offers the best chance for long-term patient survival. Clinically, ultrasonography has suboptimal sensitivity for detecting early-stage HCC. Several serological tests including alpha-fetoprotein (AFP), the ratio of lens culinaris agglutinin-reactive alpha-fetoprotein to total AFP (AFP-L3/AFP), des-gamma carboxyprothrombin (DCP), and glypican-3 (GPC-3) have been widely investigated as diagnostic biomarkers for early-stage HCC in at-risk populations. However, these tests are not recommended for routine HCC screening. Our objective is to determine the diagnostic performance of AFP, AFP-L3/AFP, DCP, and GPC-3 for the detection of HCC, particularly early-stage tumors meeting the Milan criteria. Methods/design We will include cross-sectional studies that consecutively or randomly recruit target populations. We will search the Cochrane Library, Medline, Embase, Science Citation Index, and the Chinese National Knowledge Infrastructure. We will also search the MEDION and ARIF databases to identify diagnostic systematic reviews that include primary studies. Reference lists of relevant reviews will be searched for additional trials. Language restrictions will not be applied. Two reviewers will independently screen study eligibility and extract data. Methodological quality will be assessed according to the revised tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Two authors will apply the QUADAS-2 assessment to all the included studies, and any discrepancies will be resolved by the third author. The following test characteristics will be extracted into 2 × 2 tables for all included studies: true positives, false positives, true negatives, and false negatives. Study-specific estimates of sensitivity and specificity with 95% confidence intervals will be displayed in forest plots. When possible, we will use the bivariate random-effects model or the Rutter and Gatsonis hierarchical summary receiver operating characteristic model for statistical analysis. To investigate heterogeneity, we will include study designs, population characteristics, test characteristics, and types of reference standard as the study-level variables. Discussion Our systematic review will allow patients, clinicians, and researchers to determine the diagnostic performance of AFP, AFP-L3/AFP, DCP, and GPC-3 for the detection of early-stage HCC and the potential roles of these diagnostic biomarkers in the existing diagnostic pathways. Systematic Review Registration: PROSPERO 2013; CRD42013003879 PMID:23738605

Changing patterns of thalassemia worldwide.

PubMed

Vichinsky, Elliott P

2005-01-01

Thalassemia is a growing global public health problem with an estimated 900,000 births of clinically significant thalassemia disorders expected to occur in the next 20 years. This growth will occur in disorders previously uncommon in many parts of the world. In particular, hemoglobin (Hb) E-beta-thalassemia and Hb H disease account for much of the projected increases in thalassemia. Worldwide, Hb E-beta-thalassemia is one of the most frequent hemoglobinopathies. The incidence of Hb E approaches 60% of the populations in many regions of Southeast Asia. In coastal regions of North America, its prevalence is rapidly growing. The severity of Hb E-beta-thalassemia ranges from a complete lack of symptoms to transfusion dependence. alpha-Thalassemia diseases, often considered benign, are now recognized to be more severe than originally reported. Hb H, Hb H-Constant Spring (CS), and homozygous alpha-thalassemia affect at least a million people worldwide. California considers Hb H disease a public health problem and has initiated a neonatal screening program for Hb H and particularly Hb H-CS. Homozygous alpha-thalassemia, usually fatal, is also being more commonly detected. Several regions have initiated universal prenatal screening programs to address homozygous alpha-thalassemia. In summary, the prognosis for thalassemia disorders is improving, but prenatal diagnosis and neonatal screenings are needed. Comprehensive services that address language and social barriers as well as access to Hb F-enhancing agents and transfusions are needed.

Analysis of transcriptional isoforms of collagen types IX, II, and I in the developing avian cornea by competitive polymerase chain reaction.

PubMed

Fitch, J M; Gordon, M K; Gibney, E P; Linsenmayer, T F

1995-01-01

The genes for the alpha 1(IX), alpha 1(II), and alpha 2(I) collagen chains can give rise to different isoforms of mRNA, generated by alternative promotor usage [for alpha 1(IX) and alpha 2(I)] or alternative splicing [for alpha 1(II)]. In this study, we employed competitive reverse transcriptase PCR to quantitate the amounts of transcriptional isoforms for these genes in the embryonic avian cornea from its inception (about 3 1/2 days of development) to 11 days. In order to compare values at different time points, the results were normalized to those obtained for the "housekeeping" enzyme, glycerol-3-phosphate dehydrogenase (G3PDH). These values were compared to those obtained from other tissues (anterior optic cup and cartilage) that synthesize different combinations of the collagen isoforms. We found that, in the cornea, transcripts from the upstream promotor of alpha 1(IX) collagen (termed "long IX") were predominant at stage 18-20 (about 3 1/2 days), but then fell rapidly, and remained at a low level. By 5 days (just before stromal swelling) the major mRNA isoform of alpha 1(IX) was from the downstream promoter (termed "short IX"). The relative amount of transcript for the short form of type IX collagen rose to a peak at about 6 days of development, and then declined. Throughout this period, the predominant transcriptional isoform of the collagen type II gene was IIA (i.e., containing the alternatively spliced exon 2). This indicates that the molecules of type II collagen that are assembled into heterotypic fibrils with type I collagen possess, at least transiently, an amino-terminal globular domain similar to that found in collagen types I, III, and V. For type I, the "bone/tendon" mRNA isoform of the alpha 2(I) collagen gene was predominant; transcripts from the downstream promotor were at basal levels. In other tissues expressing collagen types IX and II, long IX was expressed predominantly with the IIA form in the anterior optic cup at stage 22/23; in 14 1/2 day cartilage, long IX was expressed predominantly along with the IIB form of alpha 1(II). The downstream transcript of the alpha 2(I) gene (Icart) was found at high levels only in cartilage.

Pulse-compression ghost imaging lidar via coherent detection.

PubMed

Deng, Chenjin; Gong, Wenlin; Han, Shensheng

2016-11-14

Ghost imaging (GI) lidar, as a novel remote sensing technique, has been receiving increasing interest in recent years. By combining pulse-compression technique and coherent detection with GI, we propose a new lidar system called pulse-compression GI lidar. Our analytical results, which are backed up by numerical simulations, demonstrate that pulse-compression GI lidar can obtain the target's spatial intensity distribution, range and moving velocity. Compared with conventional pulsed GI lidar system, pulse-compression GI lidar, without decreasing the range resolution, is easy to obtain high single pulse energy with the use of a long pulse, and the mechanism of coherent detection can eliminate the influence of the stray light, which is helpful to improve the detection sensitivity and detection range.

Prussian blue-gold nanoparticles-ionic liquid functionalized reduced graphene oxide nanocomposite as label for ultrasensitive electrochemical immunoassay of alpha-fetoprotein.

PubMed

Gao, Qi; Liu, Na; Ma, Zhanfang

2014-06-04

In this work, poly(diallyldimethylammonium chloride) (PDDA) protected Prussian blue/gold nanoparticles/ionic liquid functionalized reduced graphene oxide (IL-rGO-Au-PDDA-PB) nanocomposite was fabricated. The resulting nanocomposite exhibited high biocompatibility, conductivity and catalytic activity. To assess the performance of the nanocomposite, a sensitive sandwich-type immunosensor was constructed for detecting alpha-fetoprotein (AFP). Greatly enhanced sensitivity for this immunosensor was based on triple signal amplification strategies. Firstly, IL-rGO modified electrode was used as biosensor platform to capture a large amount of antibody due to its increased surface area, thus amplifying the detection response. Secondly, a large number of Au-PDDA-PB was conjugated on the surface of IL-rGO, which meant the enrichment of the signal and the more immobilization of label antibody. Finally, the catalytic reaction between H2O2 and the IL-rGO-Au-PDDA-PB nanocomposite further enhanced the signal response. The signals increased linearly with AFP concentrations in the range of 0.01-100 ng mL(-1). The detection limit for AFP was 4.6 pg mL(-1). The immunosensor showed high sensitivity, excellent selectivity and good stability. Moreover, the immunosensor was applied to the analysis of AFP in serum sample with satisfactory result. Copyright © 2014 Elsevier B.V. All rights reserved.

Intergalactic Hydrogen Clouds at Low Redshift: Connections to Voids and Dwarf Galaxies

NASA Technical Reports Server (NTRS)

Shull, J. Michael; Stocke, John T.; Penton, Steve

1996-01-01

We provide new post-COSTAR data on one sightline (Mrk 421) and updated data from another (I Zw 1) from our Hubble Space Telescope (HST) survey of intergalactic Ly(alpha) clouds located along sightlines to four bright quasars passing through well-mapped galaxy voids (16000 km/s pathlength) and superclusters (18000 km/s). We report two more definite detections of low-redshift Ly(alpha) clouds in voids: one at 3047 km/s (heliocentric) toward Mrk 421 and a second just beyond the Local Supercluster at 2861 km/s toward I Zw 1, confirming our earlier discovery of Ly(alpha) absorption clouds in voids (Stocke et al., ApJ, 451, 24). We have now identified ten definite and one probable low-redshift neutral hydrogen absorption clouds toward four targets, a frequency of approximately one absorber every 3400 km/s above 10(exp 12.7/sq cm column density. Of these ten absorption systems, three lie within voids; the probable absorber also lies in a void. Thus, the tendency of Ly(alpha) absorbers to 'avoid the voids' is not as clear as we found previously. If the Ly(alpha) clouds are approximated as homogeneous spheres of 100 kpc radius, their masses are approximately 10(exp 9)solar mass (about 0.01 times that of bright L* galaxies) and they are 40 times more numerous, comparable to the density of dwarf galaxies and of low-mass halos in numerical CDM simulations. The Ly(alpha) clouds contribute a fraction Omega(sub cl)approximately equals 0.003/h(sub 75) to the closure density of the universe, comparable to that of luminous matter. These clouds probably require a substantial amount of nonbaryonic dark matter for gravitational binding. They may represent extended haloes of low-mass protogalaxies which have not experienced significant star formation or low-mass dwarf galaxies whose star formation ceased long ago, but blew out significant gaseous material.

Amygdala, Anxiety and Alpha(1) Adrenoceptors: Investigations Utilizing a Rodent Model of Traumatic Stress

DTIC Science & Technology

2006-08-23

Hypothalamic-pituitary-adrenocortical (HPA) Lateral hypothalamus (LH) Long-term depression (LTD) Long-term potentiation (LTP) Medial geniculate ...Aghajanian,GK. Activation of lateral geniculate neurons by norepinephrine: mediation by an alpha-adrenergic receptor. Brain Res. 1980;182: 345- 359...expressed in moderate to high levels, whereas 1B and 1D receptors are expressed at low levels. Conversely, in the lateral nucleus, 1B and 1D receptors are

Short- and long-term consequences on biochemical markers after fundectomy in pigs supplemented with 3-hydroxy-3-methylbutyrate and alpha-ketoglutarate.

PubMed

Sliwa, Ewa; Adaszek, Łukasz; Tatara, Marcin; Dobrowolski, Piotr

2010-01-01

The aim of this study was to investigate short-term 4 and 14 weeks after fundectomy) and long-term (at the age of 8 months) postoperative effects of 3-hydroxy-3-methylbutyrate and/or alpha-ketoglutarate on selected serum biochemical markers in fundectomized pigs. Experimental fundectomy was performed in 30 castrated male pigs of the Puławska breed who received placebo or 3-hydroxy-3-methylbutyrate and/or alpha-ketoglutarate up to the age of 8 months. Plasma amino acid concentrations and selected blood parameters were analyzed. Main vital organs were weighed. Our study showed that the supplementations with alpha-ketoglutarate and/or 3-hydroxy-3-methylbutyrate to fundectomized pigs significantly prevented the reduction of stomach, liver and spleen weights. However, results of this study, either positive or negative, cannot categorically establish a beneficial effect of AKG and HMB nutritional support after fundectomy in pigs.

THE PREPARATION, PROPERTIES, AND USES OF AMERICIUM-241, ALPHA-, GAMMA-, AND NEUTRON SOURCES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strain, J.E.; Leddicotte, G.W.

1962-09-01

A study was made of the preparation of alpha, gamma, and neutron sources using the long-lived radioisotope of americium, Am/sup 241/. Americium-241 is an artificiallyproduced radioelement which has a half-life of 462 plus or minus 10 years and decays to Np/sup 237/ by alpha emission followed by low-energy gamma emission. The high specific activity of americium-241 (7.0 x 10/sup 9/ d/m/mg) combined with its reasonably long half-life makes it ideally sulted for the preparation of radioactive sources. The chemical and physical properties of Am/ sup 241/ and the physical manipulations involved in fabricating alpha, gamma, and neutron sources are generallymore » described in this report. Uses for each type of source are discussed and data are presented to indicate the respective properties and usefulness of each source type. (auth)« less

Importance of interferon alpha in the resistance of allogeneic C57B1/6 mice to the multiplication of Friend erythroleukemia cells in the liver.

PubMed

Gresser, I; Maury, C; Bandu, M T; Belardelli, F

1990-02-15

Friend erythroleukemia cells (FLC) (H-2d) injected intravenously multiply extensively in the livers of syngeneic DBA/2 mice and not at all in the livers of allogeneic C57B1/6 mice. Our results indicate that interferon alpha (IFN-alpha) is an important factor in the resistance of allogeneic mice to the multiplication of FLC in the liver. (a) After i.v. inoculation of FLC there was an inverse correlation between the presence of IFN-alpha in the serum and the capacity of FLC to multiply in the liver. Thus, all 44 FLC-injected adult C57B1/6 mice had circulating IFN-alpha and FLC did not multiply in the liver of any of the mice. Interferon was not detected in the serum of 83% of 41 FLC-injected DBA/2 mice (and was found only at a low titer in 17% of the mice) and FLC multiplied in the liver of all mice. (b) FLC did multiply in the livers of newborn C57B1/6 mice and in the livers of irradiated adult C57B1/6 mice, and IFN-alpha was not detected in their sera. In contrast, after i.v. inoculation of FLC, IFN-alpha was detected in the sera of 3-week-old and athymic nu/nu adult C57B1/6 mice while FLC failed to multiply in the liver. (c) FLC also induced IFN-alpha in congenic B10.D2 (H-2d) mice and FLC did not multiply in the liver. We suggest that, depending on the site of tumor implantation, different host mechanisms have various degrees of importance in controlling the growth and/or rejection of allogeneic tumor cells, and that IFN-alpha is particularly important when FLC are injected i.v.

Challenges in miniaturized automotive long-range lidar system design

NASA Astrophysics Data System (ADS)

Fersch, Thomas; Weigel, Robert; Koelpin, Alexander

2017-05-01

This paper discusses the current technical limitations posed on endeavors to miniaturize lidar systems for use in automotive applications and how to possibly extend those limits. The focus is set on long-range scanning direct time of flight LiDAR systems using APD photodetectors. Miniaturization evokes severe problems in ensuring absolute laser safety while maintaining the systems' performance in terms of maximum range, signal-to-noise ratio, detection probability, pixel density, or frame rate. Based on hypothetical but realistic specifications for an exemplary system the complete lidar signal path is calculated. The maximum range of the system is used as a general performance indicator. It is determined with the minimum signal-to-noise ratio required to detect an object. Various system parameters are varied to find their impact on the system's range. The reduction of the laser's pulse width and the right choice for the transimpedance amplifier's amplification have shown to be practicable measures to double the system's range.

The Distributed Air Wing

DTIC Science & Technology

2014-06-01

Cruise Missile LCS Littoral Combat Ship LEO Low Earth Orbit LER Loss-Exchange-Ration LHA Landing Helicopter Assault LIDAR Laser Imaging Detection and...Ranging LOC Lines of Communication LP Linear Programming LRASM Long Range Anti-Ship Missile LT Long Ton MANA Map-Aware Non-uniform Automata ME...enemy’s spy satellites. Based on open source information, China currently has 25 satellites operating in Low Earth Orbit ( LEO ), each operates at an

The relationships between half-life (t1/2) and mean residence time (MRT) in the two-compartment open body model.

PubMed

Sobol, Eyal; Bialer, Meir

2004-05-01

In the one-compartment model following i.v. administration the mean residence time (MRT) of a drug is always greater than its half-life (t(1/2)). However, following i.v. administration, drug plasma concentration (C) versus time (t) is best described by a two-compartment model or a two exponential equation:C=Ae(-alpha t)+Be(-beta t), where A and B are concentration unit-coefficients and alpha and beta are exponential coefficients. The relationships between t(1/2) and MRT in the two-compartment model have not been explored and it is not clear whether in this model too MRT is always greater than t(1/2). In the current paper new equations have been developed that describe the relationships between the terminal t(1/2) (or t(1/2 beta)) and MRT in the two-compartment model following administration of i.v. bolus, i.v. infusion (zero order input) and oral administration (first order input). A critical value (CV) equals to the quotient of (1-ln2) and (1-beta/alpha) (CV=(1-ln2)/(1-beta/alpha)=0.307/(1-beta/alpha)) has been derived and was compared with the fraction (f(1)) of drug elimination or AUC (AUC-area under C vs t curve) associated with the first exponential term of the two-compartment equation (f(1)=A/alpha/AUC). Following i.v. bolus, CV ranges between a minimal value of 0.307 (1-ln2) and infinity. As long as f(1)t(1/2) and vice versa, and when f(1)=CV, then MRT=t(1/2). Following i.v. infusion and oral administration the denominator of the CV equation does not change but its numerator increases to (0.307+beta T/2) (T-infusion duration) and (0.307+beta/ka) (ka-absorption rate constant), respectively. Examples of various drugs are provided. For every drug that after i.v. bolus shows two-compartment disposition kinetics the following conclusions can be drawn (a) When f(1)<0.307, then f(1)t(1/2). (b) When beta/alpha>ln2, then CV>1>f(1) and thus(,) MRT>t(1/2). (c) When ln2>beta/alpha>(ln4-1), then 1>CV>0.5 and thus, in order for t(1/2)>MRT, f(1) has to be greater than its complementary fraction f(2) (f(1)>f(2)). (d) When beta/alpha<(ln4-1), it is possible that t(1/2)>MRT even when f(2)>f(1), as long as f(1)>CV. (e) As beta gets closer to alpha, CV approaches its maximal value (infinity) and therefore, the chances of MRT>t(1/2) are growing. (f) As beta becomes smaller compared with alpha, beta/alpha approaches zero, the denominator approaches unity and consequently, CV gets its minimal value and thus, the chances of t(1/2)>MRT are growing. (g) Following zero and first order input MRT increases compared with i.v. bolus and so does CV and thus, the chances of MRT>t(1/2) are growing. Copyright 2004 John Wiley & Sons, Ltd.

Cherenkov light identification in TeO2 crystals with Si low-temperature detectors

NASA Astrophysics Data System (ADS)

Gironi, L.; Biassoni, M.; Brofferio, C.; Capelli, S.; Carniti, P.; Cassina, L.; Clemenza, M.; Cremonesi, O.; Faverzani, M.; Ferri, E.; Giachero, A.; Gotti, C.; Maino, M.; Margesin, B.; Nucciotti, A.; Pavan, M.; Pessina, G.; Pozzi, S.; Previtali, E.; Puiu, A.; Sisti, M.; Terranova, F.

2017-09-01

Low temperature thermal detectors with particle identification capabilities are among the best detectors for next generation experiments for the search of neutrinoless double beta decay. Thermal detectors allow to reach excellent energy resolution and to optimize the detection efficiency, while the possibility to identify the interacting particle allows to greatly reduce the background. Tellurium dioxide is one of the favourite compounds since it has long demonstrated the first two features and could reach the third through Cherenkov emission tagging [1]. A new generation of cryogenic light detectors are however required to detect the few Cherenkov photons emitted by electrons of few MeV energy. Preliminary measurements with new Si light detectors demonstrated a clear event-by-event discrimination between alpha and beta/gamma interactions at the 130Te neutrinoless double beta decay Q-value (2528 keV).

The Seyfert 2 Galaxy NGC 2110: Hard X-Ray Emission Observed by NuStar and Variability of the Iron K-Alpha Line

NASA Technical Reports Server (NTRS)

Marinucci, A.; Matt, G.; Bianchi, S.; Lu, T. N.; Arevalo, P.; Balokovic, M.; Ballantyne, D.; Bauer, F. E.; Boggs, S. E.; Stern, D.;

Micro-scale characterization of a CMOS-based neutron detector for in-phantom measurements in radiation therapy

NASA Astrophysics Data System (ADS)

Arbor, Nicolas; Higueret, Stephane; Husson, Daniel

2018-04-01

The CMOS sensor AlphaRad has been designed at the IPHC Strasbourg for real-time monitoring of fast and thermal neutrons over a full energy spectrum. Completely integrated, highly transparent to photons and optimized for low power consumption, this sensor offers very interesting characteristics for the study of internal neutrons in radiation therapy with anthropomorphic phantoms. However, specific effects related to the CMOS metal substructure and to the charge collection process of low energy particles must be carefully estimated before being used for medical applications. We present a detailed characterization of the AlphaRad chip in the MeV energy range using proton and alpha micro-beam experiments performed at the AIFIRA facility (CENBG, Bordeaux). Two-dimensional maps of the charge collection were carried out on a micro-metric scale to be integrated into a Geant4 Monte Carlo simulation of the system. The gamma rejection, as well as the fast and thermal neutrons separation, were studied using both simulation and experimental data. The results highlight the potential of a future system based on CMOS sensor for in-phantom neutron detection in radiation therapies.

Effect of long-term exposure to mobile phone radiation on alpha-Int1 gene sequence of Candida albicans

PubMed Central

Shahin-jafari, Ariyo; Bayat, Mansour; Shahhosseiny, Mohammad Hassan; Tajik, Parviz; Roudbar-mohammadi, Shahla

2015-01-01

Over the last decade, communication industries have witnessed a tremendous expansion, while, the biological effects of electromagnetic waves have not been fully elucidated. Current study aimed at evaluating the mutagenic effect of long-term exposure to 900-MHz radiation on alpha-Int1 gene sequences of Candida albicans. A standard 900 MHz radiation generator was used for radiation. 10 ml volumes from a stock suspension of C. albicans were transferred into 10 polystyrene tubes. Five tubes were exposed at 4 °C to a fixed magnitude of radiation with different time periods of 10, 70, 210, 350 and 490 h. The other 5 tubes were kept far enough from radiation. The samples underwent genomic DNA extraction. PCR amplification of alpha-Int1 gene sequence was done using one set of primers. PCR products were resolved using agarose gel electrophoresis and the nucleotide sequences were determined. All samples showed a clear electrophoretic band around 441 bp and further sequencing revealed the amplified DNA segments are related to alpha-Int1 gene of the yeast. No mutations in the gene were seen in radiation exposed samples. Long-term exposure of the yeast to mobile phone radiation under the above mentioned conditions had no mutagenic effect on alpha-Int1 gene sequence. PMID:27081370

Effect of long-term exposure to mobile phone radiation on alpha-Int1 gene sequence of Candida albicans.

PubMed

Shahin-Jafari, Ariyo; Bayat, Mansour; Shahhosseiny, Mohammad Hassan; Tajik, Parviz; Roudbar-Mohammadi, Shahla

2016-05-01

Over the last decade, communication industries have witnessed a tremendous expansion, while, the biological effects of electromagnetic waves have not been fully elucidated. Current study aimed at evaluating the mutagenic effect of long-term exposure to 900-MHz radiation on alpha-Int1 gene sequences of Candida albicans. A standard 900 MHz radiation generator was used for radiation. 10 ml volumes from a stock suspension of C. albicans were transferred into 10 polystyrene tubes. Five tubes were exposed at 4 °C to a fixed magnitude of radiation with different time periods of 10, 70, 210, 350 and 490 h. The other 5 tubes were kept far enough from radiation. The samples underwent genomic DNA extraction. PCR amplification of alpha-Int1 gene sequence was done using one set of primers. PCR products were resolved using agarose gel electrophoresis and the nucleotide sequences were determined. All samples showed a clear electrophoretic band around 441 bp and further sequencing revealed the amplified DNA segments are related to alpha-Int1 gene of the yeast. No mutations in the gene were seen in radiation exposed samples. Long-term exposure of the yeast to mobile phone radiation under the above mentioned conditions had no mutagenic effect on alpha-Int1 gene sequence.

Base compositions of genes encoding alpha-actin and lactate dehydrogenase-A from differently adapted vertebrates show no temperature-adaptive variation in G + C content.

PubMed

Ream, Rachael A; Johns, Glenn C; Somero, George N

2003-01-01

There is a long-standing debate in molecular evolution concerning the putative importance of GC content in adapting the thermal stabilities of DNA and RNA. Most studies of this relationship have examined broad-scale compositional patterns, for example, total GC percentages in genomes and occurrence of GC-rich isochores. Few studies have systematically examined the GC contents of individual orthologous genes from differently thermally adapted species. When this has been done, the emphasis has been on comparing large numbers of genes in only a few species. We have approached the GC-adaptation temperature hypothesis in a different manner by examining patterns of base composition of genes encoding lactate dehydrogenase-A (ldh-a) and alpha-actin (alpha-actin) from 51 species of vertebrates whose adaptation temperatures ranged from -1.86 degrees C (Antarctic fishes) to approximately 45 degrees C (desert reptile). No significant positive correlation was found between any index of GC content (GC content of the entire sequence, GC content of the third codon position [GC(3)], and GC content at fourfold degenerate sites [GC(4)]) and any index of adaptation temperature (maximal, mean, or minimal body temperature). For alpha-actin, slopes of regression lines for all comparisons did not differ significantly from zero. For ldh-a, negative correlations between adaptation temperature and total GC content, GC(3), and GC(4) were observed but were shown to be due entirely to phylogenetic influences (as revealed by independent contrast analyses). This comparison of GC content across a wide range of ectothermic ("cold-blooded") and endothermic ("warm-blooded") vertebrates revealed that frogs of the genus Xenopus, which have commonly been used as a representative cold-blooded species, in fact are outliers among ectotherms for the alpha-actin analyses, raising concern about the appropriateness of choosing these amphibians as representative of ectothermic vertebrates in general. Our study indicates that, whereas GC contents of isochores may show variation among different classes of vertebrates, there is no consistent relationship between adaptation temperature and the percentage of thermal stability-enhancing G + C base pairs in protein-coding genes.

Complex chromosome aberrations persist in individuals many years after occupational exposure to densely ionizing radiation: an mFISH study.

PubMed

Hande, M Prakash; Azizova, Tamara V; Burak, Ludmilla E; Khokhryakov, Valentin F; Geard, Charles R; Brenner, David J

2005-09-01

Long-lived, sensitive, and specific biomarkers of particular mutagenic agents are much sought after and potentially have broad applications in the fields of cancer biology, epidemiology, and prevention. Many clastogens induce a spectrum of chromosome aberrations, and some of them can be exploited as biomarkers of exposure. Densely ionizing radiation, for example, alpha particle radiation (from radon or plutonium) and neutron radiation, preferentially induces complex chromosome aberrations, which can be detected by the 24-color multifluor fluorescence in situ hybridization (mFISH) technique. We report the detection and quantification of stable complex chromosome aberrations in lymphocytes of healthy former nuclear-weapons workers, who were exposed many years ago to plutonium, gamma rays, or both, at the Mayak weapons complex in Russia. We analyzed peripheral-blood lymphocytes from these individuals for the presence of persistent complex chromosome aberrations. A significantly elevated frequency of complex chromosome translocations was detected in the highly exposed plutonium workers but not in the group exposed only to high doses of gamma radiation. No such differences were found for simple chromosomal aberrations. The results suggest that stable complex chromosomal translocations represent a long-lived, quantitative, low-background biomarker of densely ionizing radiation for human populations exposed many years ago. (c) 2005 Wiley-Liss, Inc.

[Cloning of Chinese Banna minipig inbred-line alpha1,3-galactosyltransferase gene and construction of its recombinant eukaryotic expression vector].

PubMed

Zhu, Shengming; Wang, Yanping; Zheng, Hong; Cheng, Jingqiu; Lu, Yanrong; Zeng, Yangzhi; Wang, Yu; Wang, Zhu

2009-04-01

This study sought to clone Chinese Banna minipig inbred-line (BMI) alpha1,3-galactosyltransferase (alpha1,3-GT) gene and construct its recombinant eukaryotic expression vector. Total RNA was isolated from BMI liver. Full length cDNA of alpha1,3-GT gene was amplified by RT-PCR and cloned into pMD18-T vector to sequence. Subsequently, alpha1,3-GT gene was inserted into pEGFP-N1 to construct eukaryotic expression vector pEGFP-N1-GT. Then the reconstructed plasmid pEGFP-N1-GT was transiently transfected into human lung cancer cell line A549. The expression of alpha1,3-GT mRNA in transfected cells was detected by RT-PCR. FITC-BS-IB4 lectin was used in the direct immunofluorescence method, which was performed to observe the alpha-Gal synthesis function of BMI alpha1,3-GT in transfected cells. The results showed that full length of BMI alpha1,3-GT cDNA was 1116 bp. BMI alpha1,3-GT cDNA sequence was highly homogenous with those of mouse and bovine, and was exactly the same as the complete sequence of those of swine, pEGFP-N1-GT was confirmed by enzyme digestion and PCR. The expression of alpha1,3-GT mRNA was detected in A549 cells transfected by pEGFP-N1-GT. The expression of alpha-Gal was observed on the membrane of A549 cells transfected by pEGFP-N1-GT. Successful cloning of BMI alpha1,3-GT cDNA and construction of its eukaryotic expression vector have established a foundation for further research and application of BMI alpha1,3-GT in the fields of xenotransplantation and immunological therapy of cancer.

Galaxy interactions and star formation: Results of a survey of global H-alpha emission in spiral galaxies in 8 clusters

NASA Technical Reports Server (NTRS)

Moss, C.

1990-01-01

Kennicutt and Kent (1983) have shown that the global H alpha emission from a spiral galaxy is an indicator of the formation rate of massive stars. Moss, Whittle and Irwin (1988) have surveyed two clusters (Abell 347 and 1367) for galaxies with H alpha emission using a high dispersion objective prism technique. The purpose of the survey is to investigate environmental effects on star formation in spiral galaxies, and in particular to ascertain whether star formation is enhanced in cluster spirals. Approximately 20 percent of CGCG galaxies were detected in emission. Two plates of excellent quality were obtained for each of the two clusters, and galaxies were only identified to have emission if this was detected on both plates of a plate pair. In this way, plate flaws and other spurious identifications of emission could be rejected, and weak emission confirmed. The results of this survey have been discussed by Moss (1987). The detected galaxies are of types SO-a and later. The frequency with which galaxies are detected in emission increases towards later morphological type as expected (cf. Kennicutt and Kent 1983). There is no evidence of any dependence of the frequency of detected emission on the absolute magnitude of the galaxy (cf. Moss and Whittle 1990), but there is a strong correlation between a disturbed morphological appearance of the galaxy and the detection of emission. Furthermore it is found that the emission is more centrally concentrated in those galaxies which show a disturbed morphology. It may be noted that the objective prism plate gives a spectrum of a 400 A region around rest wavelength H alpha, but superposed on this is the H alpha emission from the galaxy which, because the light is essentially monochromatic, results in a true two-dimensional image of the H alpha distribution. The visual appearance of the emission on the prism plates was classified according to its diffuseness on a 5 point scale (very diffuse, diffuse, intermediate, compact, and very compact). In tabular form, the relation is shown between this classification and a morphologically disturbed appearance for the galaxy.

Galex Lyman-alpha Emitters: Physical Properties, Luminosity Bimodality, And Morphologies.

NASA Astrophysics Data System (ADS)

Mallery, Ryan P.

2010-01-01

The Galaxy Evolution Explorer spectroscopic survey has uncovered a large statistically significant sample of Lyman-alpha emitters at z sim0.3. ACS imaging of these sources in the COSMOS and AEGIS deep fields reveals that these Lyman-alpha emitters consist of two distinct galaxy morphologies, face on spiral galaxies and compact starburst/merging systems. The morphology bimodality also results in a bimodal distribution of optical luminosity. A comparison between the UV photometry and MIPS 24 micron detections of these sources indicates that they are bluer, and have less dust extinction than similar star forming galaxies that lack Lyman-alpha detection. Our findings show how the global gas and dust distribution of star forming galaxies inhibits Lyman-alpha emission in star forming galaxies. GALEX is a NASA Small Explorer, launched in April 2003. We gratefully acknowledge NASA's support for construction, operation, and science analysis for the GALEX mission, developed in cooperation with the CNES of France and the Korean Ministry of Science and Technology.

Collaborative Point Paper on Border Surveillance Technology

DTIC Science & Technology

2007-06-01

Systems PLC LORHIS (Long Range Hyperspectral Imaging System ) can be configured for either manned or unmanned aircraft to automatically detect and...Airships, and/or Aerostats, (RF, Electro-Optical, Infrared, Video) • Land- based Sensor Systems (Attended/Mobile and Unattended: e.g., CCD, Motion, Acoustic...electronic surveillance technologies for intrusion detection and warning. These ground- based systems are primarily short-range, up to around 500 meters

The Assessment of Reliability Under Range Restriction: A Comparison of [Alpha], [Omega], and Test-Retest Reliability for Dichotomous Data

ERIC Educational Resources Information Center

Fife, Dustin A.; Mendoza, Jorge L.; Terry, Robert

2012-01-01

Though much research and attention has been directed at assessing the correlation coefficient under range restriction, the assessment of reliability under range restriction has been largely ignored. This article uses item response theory to simulate dichotomous item-level data to assess the robustness of KR-20 ([alpha]), [omega], and test-retest…

Vitamin E Supplementation in Burn Patients

DTIC Science & Technology

2013-10-01

consequences of this severe and rapid depletion are unknown because adipose tissue alpha- tocopherol normally takes years to deplete. Our long- term...proposal were to a) attenuate alpha- tocopherol depletion in burn patients by vitamin E supplementation, b) to prevent or reverse oxidative stress, c...hypothesis is that the administration of high doses of alpha- tocopherol will prevent or restore levels of vitamin E in adipose tissue and reverse

Vitamin E Supplementation in Burn Patients

DTIC Science & Technology

2014-10-01

The consequences of this severe and rapid depletion are unknown because adipose tissue alpha- tocopherol normally takes years to deplete. Our long...our proposal were to a) attenuate alpha- tocopherol depletion in burn patients by vitamin E supplementation, b) to prevent or reverse oxidative...central hypothesis is that the administration of high doses of alpha- tocopherol will prevent or restore levels of vitamin E in adipose tissue and

The Strontium Filament within the Homunculus of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Hartman, H.; Zethson, T.; Johansson, S.; Ishibashi, K.; Davidson, K.; Fisher, Richard R. (Technical Monitor)

2001-01-01

During a series of HST/STIS observations of Eta Carinae and associated ejecta, we noticed a peculiar emission filament located a few arcseconds north of the central source. While bright in nebular standards, it is submerged in a sea of scattered starlight until moderately high dispersion, long-slit spectroscopy with the STIS (R- 8000) brings the emission lines out. The initial spectrum, centered on 6768A with the STIS G750M grating, led to identification of twenty lines from singly-Ionized species including [Sr II], [Fe II], [Ti II], [Ni II], [Mn II], and [Co II] (Zethson, etal., 2001, AJ 122,322). No Balmer emission is detected from this filament and the Fe II 2507,9 lines, known to be pumped by Lyman alpha radiation in other regions near the central source, are not detected. Followup observations have led to detection of hundreds more emission lines from iron group elements in neutral and singly-ionized states. Thus far all are excited by less than 10 eV. This peculiar nebular emission is thought to be due to very intense stellar radiation, stripped of uv flux shortward of Lyman alpha, bathing a neutral structure. We are systematically identifying the many lines (over 90% identified) and measuring line intensities that will then be modeled to determine excitation mechanisms, temperature and density. Two [Sr II] and two Sr II lines have now been measured. Bautista, etal. (in preparation) have modeled the strontium flux ratios and find that large radiation fluxes and/or high strontium abundances may account for the detected emission. These observations were supported by STIS GTO funding and GO funding through the STScI

Position-sensitive radiation monitoring (surface contamination monitor). Innovative technology summary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1999-06-01

The Shonka Research Associates, Inc. Position-Sensitive Radiation Monitor both detects surface radiation and prepares electronic survey map/survey report of surveyed area automatically. The electronically recorded map can be downloaded to a personal computer for review and a map/report can be generated for inclusion in work packages. Switching from beta-gamma detection to alpha detection is relatively simple and entails moving a switch position to alpha and adjusting the voltage level to an alpha detection level. No field calibration is required when switching from beta-gamma to alpha detection. The system can be used for free-release surveys because it meets the federal detectionmore » level sensitivity limits requires for surface survey instrumentation. This technology is superior to traditionally-used floor contamination monitor (FCM) and hand-held survey instrumentation because it can precisely register locations of radioactivity and accurately correlate contamination levels to specific locations. Additionally, it can collect and store continuous radiological data in database format, which can be used to produce real-time imagery as well as automated graphics of survey data. Its flexible design can accommodate a variety of detectors. The cost of the innovative technology is 13% to 57% lower than traditional methods. This technology is suited for radiological surveys of flat surfaces at US Department of Energy (DOE) nuclear facility decontamination and decommissioning (D and D) sites or similar public or commercial sites.« less

Dysregulation of in vitro cytokine production by monocytes during sepsis.

PubMed Central

Munoz, C; Carlet, J; Fitting, C; Misset, B; Blériot, J P; Cavaillon, J M

1991-01-01

The production by monocytes of interleukin-1 alpha (IL-1 alpha), interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF alpha) in intensive care unit (ICU) patients with sepsis syndrome (n = 23) or noninfectious shock (n = 6) is reported. Plasma cytokines, cell-associated cytokines within freshly isolated monocytes and LPS-induced in vitro cytokine production were assessed at admission and at regular intervals during ICU stay. TNF alpha and IL-6 were the most frequently detected circulating cytokines. Despite the fact that IL-1 alpha is the main cytokine found within monocytes upon in vitro activation of cells from healthy individuals, it was very rarely detected within freshly isolated monocytes from septic patients, and levels of cell-associated IL-1 beta were lower than those of TNF alpha. Cell-associated IL-1 beta and TNF alpha were not correlated with corresponding levels in plasma. Upon LPS stimulation, we observed a profound decrease of in vitro IL-1 alpha production by monocytes in all patients, and of IL-1 beta, IL-6, and TNF alpha in septic patients. This reduced LPS-induced production of cytokines was most pronounced in patients with gram-negative infections. Finally, monocytes from survival patients, but not from nonsurvival ones recovered their capacity to produce normal amounts of cytokines upon LPS stimulation. In conclusion, our data indicate an in vivo activation of circulating monocytes during sepsis as well as in noninfectious shock and suggest that complex regulatory mechanisms can downregulate the production of cytokines by monocytes during severe infections. Images PMID:1939659

Construction of promoter-probe shuttle vectors for Escherichia coli and corynebacteria on the basis of promoterless alpha-amylase gene.

PubMed

Ugorcáková, J; Bukovská, G; Timko, J

2000-01-01

We constructed new promoter-probe vectors for E. coli and corynebacteria based on the promoterless alpha-amylase gene originating from Bacillus subtilis. Vectors pJUPAE1 and pJUPAE2 are suitable for isolation of transcriptionally active fragments from plasmids, phages or genomic DNA. alpha-Amylase activity can be easily visually detected on agar plates containing a chromogenic substrate, or by direct measurement of alpha-amylase activity.

X-ray emission on hybird stars: ROSAT observations of alpha Trianguli Australis and iota Aurigae

NASA Technical Reports Server (NTRS)

Kashyap, V.; Rosner, R.; Harnden, F. R., Jr.; Maggio, A.; Micela, G.; Sciortino, S.

1994-01-01

We report on deep ROSAT observations of two Hybrid atmosphere stars, alpha TrA and iota Aur, and our analysis of these observations. We detect high-energy transient phenomena on alpha TrA and consider the implications of this discovery to the atmospheres of Hybrid stars. We detect iota Aur in the high-energy passband of ROSAT, implying the existence of multimillion degree plasma on the star. Our major results include the following: discovery of two large flare events, detected during pointed observations of alpha TrA; the demonstration that the flare emission most likely comes from the giant itself, rather than from a previously unseen low-mass companion star; the demonstration that the plasma characteristics associated with the flares and with the 'quiescent' component are essentially indistinguishable; and that the geometric dimensions of the emitting plasma are considerably smaller than the critical dimension characterizing stable 'hot' coronal loop structures. Our results suggest that alpha TrA does not have any steady X-ray emission consistent with theoretical expectations, and support the argument that Hybrid stars constitute a transitional type of object in which large-scale magnetic dynamo activity ceases, and the dominant spatial scales characterizing coronal structure rapidly decline as such stars evolve across the X-ray 'Dividing Line' in the H-R diagram.

Specific 13C labeling of leucine, valine and isoleucine methyl groups for unambiguous detection of long-range restraints in protein solid-state NMR studies.

PubMed

Fasshuber, Hannes Klaus; Demers, Jean-Philippe; Chevelkov, Veniamin; Giller, Karin; Becker, Stefan; Lange, Adam

2015-03-01

Here we present an isotopic labeling strategy to easily obtain unambiguous long-range distance restraints in protein solid-state NMR studies. The method is based on the inclusion of two biosynthetic precursors in the bacterial growth medium, α-ketoisovalerate and α-ketobutyrate, leading to the production of leucine, valine and isoleucine residues that are exclusively (13)C labeled on methyl groups. The resulting spectral simplification facilitates the collection of distance restraints, the verification of carbon chemical shift assignments and the measurement of methyl group dynamics. This approach is demonstrated on the type-three secretion system needle of Shigella flexneri, where 49 methyl-methyl and methyl-nitrogen distance restraints including 10 unambiguous long-range distance restraints could be collected. By combining this labeling scheme with ultra-fast MAS and proton detection, the assignment of methyl proton chemical shifts was achieved. Copyright © 2015 Elsevier Inc. All rights reserved.

Radon Diffusion Measurement in Polyethylene based on Alpha Detection

NASA Astrophysics Data System (ADS)

Rau, Wolfgang

2011-04-01

We present a method to measure the diffusion of Radon in solid materials based on the alpha decay of the radon daughter products. In contrast to usual diffusion measurements which detect the radon that penetrates a thin barrier, we let the radon diffuse into the material and then measure the alpha decays of the radon daughter products in the material. We applied this method to regular and ultra high molecular weight poly ethylene and find diffusion lengths of order of mm as expected. However, the preliminary analysis shows significant differences between two different approaches we have chosen. These differences may be explained by the different experimental conditions.

Detecting potential teratogenic alkaloids from blue cohosh rhizomes using an in vitro rat embryo culture.

PubMed

Kennelly, E J; Flynn, T J; Mazzola, E P; Roach, J A; McCloud, T G; Danford, D E; Betz, J M

1999-10-01

The novel alkaloid thalictroidine (1), as well as the known alkaloids taspine (2), magnoflorine (3), anagyrine (4), baptifoline (5), 5,6-dehydro-alpha-isolupanine (6), alpha-isolupanine (7), lupanine (8), N-methylcytisine (9), and sparteine (10), were identified from an extract of Caulophyllum thalictroides rhizomes. N-Methylcytisine exhibited teratogenic activity in the rat embryo culture (REC), an in vitro method to detect potential teratogens. The structure of 1 was elucidated using various spectroscopic methods, primarily by NMR techniques. Thalictroidine, anagyrine, and alpha-isolupanine were not teratogenic in the REC at tested concentrations. Taspine (2) showed high embryotoxicity, but no teratogenic activity, in the REC.

Investigation of atomic oxygen-surface interactions related to measurements with dual air density explorer satellites

NASA Technical Reports Server (NTRS)

Wood, B. J.; Ablow, C. M.; Wise, H.

1973-01-01

For a number of candidate materials of construction for the dual air density explorer satellites the rate of oxygen atom loss by adsorption, surface reaction, and recombination was determined as a function of surface and temperature. Plain aluminum and anodized aluminum surfaces exhibit a collisional atom loss probability alpha .01 in the temperature range 140 - 360 K, and an initial sticking probability. For SiO coated aluminum in the same temperature range, alpha .001 and So .001. Atom-loss on gold is relatively rapid alpha .01. The So for gold varies between 0.25 and unity in the temperature range 360 - 140 K.

Theory for long memory in supply and demand.

PubMed

Lillo, Fabrizio; Mike, Szabolcs; Farmer, J Doyne

2005-06-01

Recent empirical studies have demonstrated long-memory in the signs of orders to buy or sell in financial markets [J.-P. Bouchaud, Y. Gefen, M. Potters, and M. Wyart, Quant. Finance 4, 176 (2004); F. Lillo and J. D. Farmer Dyn. Syst. Appl. 8, 3 (2004)]. We show how this can be caused by delays in market clearing. Under the common practice of order splitting, large orders are broken up into pieces and executed incrementally. If the size of such large orders is power-law distributed, this gives rise to power-law decaying autocorrelations in the signs of executed orders. More specifically, we show that if the cumulative distribution of large orders of volume v is proportional to v(-alpha) and the size of executed orders is constant, the autocorrelation of order signs as a function of the lag tau is asymptotically proportional to tau(-(alpha-1)). This is a long-memory process when alpha < 2. With a few caveats, this gives a good match to the data. A version of the model also shows long-memory fluctuations in order execution rates, which may be relevant for explaining the long memory of price diffusion rates.

Alpha-helix to beta-sheet transition in long-chain poly-l-lysine: Formation of alpha-helical fibrils by poly-l-lysine.

PubMed

Cieślik-Boczula, Katarzyna

2017-06-01

The temperature-induced α-helix to β-sheet transition in long-chain poly-l-lysine (PLL), accompanied by the gauche-to-trans isomerization of CH 2 groups in the hydrocarbon side chains of Lys amino acid residues, and formation of β-sheet as well as α-helix fibrillar aggregates of PLL have been studied using Fourier-transform infrared (FT-IR) and vibrational circular dichroism (VCD) spectroscopy, and transmission electron microscopy (TEM). In a low-temperature alkaline water solution or in a methanol-rich water mixture, the secondary structure of PLL is represented by α-helical conformations with unordered and gauche-rich hydrocarbon side chains. Under these conditions, PLL molecules aggregate into α-helical fibrils. PLLs dominated by extended antiparallel β-sheet structures with highly ordered trans-rich hydrocarbon side chains are formed in a high-temperature range at alkaline pD and aggregate into fibrillar, protofibrillar, and spherical forms. Presented data support the idea that fibrillar aggregation is a varied phenomenon possible in repetitive structural elements with not only a β-sheet-rich conformation, but also an α-helical-rich conformation. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

NMR solution structure of the mitochondrial F1beta presequence from Nicotiana plumbaginifolia.

PubMed

Moberg, Per; Nilsson, Stefan; Ståhl, Annelie; Eriksson, Anna-Carin; Glaser, Elzbieta; Mäler, Lena

2004-03-05

We have isolated, characterized and determined the three-dimensional NMR solution structure of the presequence of ATPsynthase F1beta subunit from Nicotiana plumbaginifolia. A general method for purification of presequences is presented. The method is based on overexpression of a mutant precursor containing a methionine residue introduced at the processing site, followed by CNBr-cleavage and purification of the presequence on a cation-exchange column. The F1beta presequence, 53 amino acid residues long, retained its native properties as evidenced by inhibition of in vitro mitochondrial import and processing at micromolar concentrations. CD spectroscopy revealed that the F1beta presequence formed an alpha-helical structure in membrane mimetic environments such as SDS and DPC micelles (approximately 50% alpha-helix), and in acidic phospholipid bicelles (approximately 60% alpha-helix). The NMR solution structure of the F1beta presequence in SDS micelles was determined on the basis of 518 distance and 21 torsion angle constraints. The structure was found to contain two helices, an N-terminal amphipathic alpha-helix (residues 4-15) and a C-terminal alpha-helix (residues 43-53), separated by a largely unstructured 27 residue long internal domain. The N-terminal amphipathic alpha-helix forms the putative Tom20 receptor binding site, whereas the C-terminal alpha-helix is located upstream of the mitochondrial processing peptidase cleavage site.

Post-Training Intrahippocampal Injection of Synthetic Poly-Alpha-2,8-Sialic Acid-Neural Cell Adhesion Molecule Mimetic Peptide Improves Spatial Long-Term Performance in Mice

ERIC Educational Resources Information Center

Florian, Cedrick; Foltz, Jane; Norreel, Jean-Chretien; Rougon, Genevieve; Roullet, Pascal

2006-01-01

Several data have shown that the neural cell adhesion molecule (NCAM) is necessary for long-term memory formation and might play a role in the structural reorganization of synapses. The NCAM, encoded by a single gene, is represented by several isoforms that differ with regard to their content of alpha-2,8-linked sialic acid residues (PSA) on their…

Laser-ranging long-baseline differential atom interferometers for space

NASA Astrophysics Data System (ADS)

Chiow, Sheng-wey; Williams, Jason; Yu, Nan

2015-12-01

High-sensitivity differential atom interferometers (AIs) are promising for precision measurements in science frontiers in space, including gravity-field mapping for Earth science studies and gravitational wave detection. Difficulties associated with implementing long-baseline differential AIs have previously included the need for a high optical power, large differential Doppler shifts, and narrow dynamic range. We propose a configuration of twin AIs connected by a laser-ranging interferometer (LRI-AI) to provide precise information of the displacements between the two AI reference mirrors and also to phase-lock the two independent interferometer lasers over long distances, thereby drastically improving the practical feasibility of long-baseline differential AI measurements. We show that a properly implemented LRI-AI can achieve equivalent functionality to the conventional differential AI measurement configuration.

Spectroscopic CCD surveys for quasars at large redshift. 3: The Palomar Transit Grism Survey catalog

NASA Technical Reports Server (NTRS)

Schneider, Donald P.; Schmidt, Maarten; Gunn, James E.

1994-01-01

This paper reports the initial results of the Palomar Transit Grism Survey (PTGS). The PTGS was designed to produce a sample of z greater than 2.7 quasars that were identified by well-defined selection criteria. The survey consists of six narrow (approximately equal to 8.5 min wide) strips of sky; the total effective area is 61.47 sq deg. Low-resolution slitless spectra, covering the wavelength range from 4400 to 7500 A, were obtained for approximately 600 000 objects. The wavelength- and flux-calibrated spectra were searched for emission lines with an automatic software algorithm. A total to 1655 emission features in the grism data satisfied our signal-to-noise ratio and equivalent width selection criteria; subsequent slit spectroscopy of the candidates confirmed the existence of 1052 lines (928 different objects). Six groups of emission lines were detected in the survey: Lyman alpha + N V, C IV, C III1, Mg II, H Beta + (O III), and H alpha + (S II). More than two-thirds of the candidates are low-redshift (z less than 0.45) emission-line galaxies; ninety objects are high-redshift quasars (z greater than 2.7) detected via their Lyman alpha + N V emission lines. The survey contains three previously unknown quasars brighter than 17th magnitude; all three have redshifts of approximately equal to 1.3. In this paper we present the observational properties of the survey, the algorithms used to select the emission-line candidates, and the catalog of emission-line objects.

Serum concentrations of micronutrient antioxidants in an adult Arab population.

PubMed

Abiaka, Clifford; Olusi, Samuel; Simbeye, Amos

2002-01-01

Serum concentrations of retinol, alpha-tocopherol, beta-carotene and lycopene were measured by reversed-phase high-performance liquid chromatography (r-P HPLC) in 260 randomly selected healthy adult Kuwaitis (159 men and 101 women) aged 18-63 years (mean 33.3 years) to established reference ranges of the micronutrient antioxidants. Total cholesterol concentrations were assayed by an enzymatic method to determine alpha-tocopherol: cholesterol ratios. The mean +/- SEM (micromol/L) for retinol, alpha-tocopherol, beta-carotene and lycopene were 1.76+/-0.02, 20.0+/-0.5, 0.52+/-0.03, 0.95+/-0.05, respectively. Compared to other populations, these data showed, on the whole, ordinary concentrations of beta-carotene, comparatively low concentrations of retinol and alpha-tocopherol and high concentrations of lycopene. Retinol concentrations were similar for both sexes, whereas alpha-tocopherol concentration was significantly (P < 0.0001) lower and the carotenoid levels (beta-carotene and lycopene) significantly higher (P < 0.0001) in women. Of the micronutrient antioxidants, alpha-tocopherol was most correlated with cholesterol (r = 0.492, P < 0.0001). beta-Carotene and lycopene were highly correlated with each other (r =0.744, P< 0.0001). Age was positively associated with beta-carotene (r = 0.214, P = 0.001) and lycopene (r = 239, P< 0.0001). Our data enabled us to establish a gender non-specific reference range for retinol and gender-specific reference ranges for alpha-tocopherol, beta-carotene and lycopene.

AlphaSpace: Fragment-Centric Topographical Mapping To Target Protein–Protein Interaction Interfaces

PubMed Central

2016-01-01

Inhibition of protein–protein interactions (PPIs) is emerging as a promising therapeutic strategy despite the difficulty in targeting such interfaces with drug-like small molecules. PPIs generally feature large and flat binding surfaces as compared to typical drug targets. These features pose a challenge for structural characterization of the surface using geometry-based pocket-detection methods. An attractive mapping strategy—that builds on the principles of fragment-based drug discovery (FBDD)—is to detect the fragment-centric modularity at the protein surface and then characterize the large PPI interface as a set of localized, fragment-targetable interaction regions. Here, we introduce AlphaSpace, a computational analysis tool designed for fragment-centric topographical mapping (FCTM) of PPI interfaces. Our approach uses the alpha sphere construct, a geometric feature of a protein’s Voronoi diagram, to map out concave interaction space at the protein surface. We introduce two new features—alpha-atom and alpha-space—and the concept of the alpha-atom/alpha-space pair to rank pockets for fragment-targetability and to facilitate the evaluation of pocket/fragment complementarity. The resulting high-resolution interfacial map of targetable pocket space can be used to guide the rational design and optimization of small molecule or biomimetic PPI inhibitors. PMID:26225450

Determination of (alpha)-dialkylamino acids and their Enantiomers in Geological Samples by High-Performance Liquid Chromatography after Dervatization with a Chiral Adduct of (omicron)-Phthaldialdehyde

NASA Technical Reports Server (NTRS)

Zhoa, Meixun; Bada, Jeffrey L.

1995-01-01

Derivatization with (omicron)-phthaldialdehyde (OPA) and the chiral thiol N-acetyl-L-cysteine (NAC) is a convenient and sensitive technique for the HPLC detection and resolution of protein amino acid enantiomers. The kinetics of the reaction of OPA-NAC with (alpha)-dialkylamino acids was investigated. The fluorescence yield of (alpha)-dialkylamino acids was only about 10% of that of protein amino acids when the derivatization was carried out at room temperature for 1-2 min, which is the procedure generally used for protein amino acid analyses. The fluorescence yield of (alpha)-dialkylamino acids can be enhanced by up to ten-fold when the derivatization reaction time is increased to 15 min at room temperature. The OPA-NAC technique was optimized for the detection and enantiomeric resolution of a-dialkylamino acids in geological samples which contain a large excess of protein amino acids. The estimated detection limit for a-dialkylamino acids is 1-2 pmol, comparable to that for protein amino acids.

Fluorescent x-ray computed tomography to visualize specific material distribution

NASA Astrophysics Data System (ADS)

Takeda, Tohoru; Yuasa, Tetsuya; Hoshino, Atsunori; Akiba, Masahiro; Uchida, Akira; Kazama, Masahiro; Hyodo, Kazuyuki; Dilmanian, F. Avraham; Akatsuka, Takao; Itai, Yuji

1997-10-01

Fluorescent x-ray computed tomography (FXCT) is being developed to detect non-radioactive contrast materials in living specimens. The FXCT systems consists of a silicon channel cut monochromator, an x-ray slit and a collimator for detection, a scanning table for the target organ and an x-ray detector for fluorescent x-ray and transmission x-ray. To reduce Compton scattering overlapped on the K(alpha) line, incident monochromatic x-ray was set at 37 keV. At 37 keV Monte Carlo simulation showed almost complete separation between Compton scattering and the K(alpha) line. Actual experiments revealed small contamination of Compton scattering on the K(alpha) line. A clear FXCT image of a phantom was obtained. Using this system the minimal detectable dose of iodine was 30 ng in a volume of 1 mm3, and a linear relationship was demonstrated between photon counts of fluorescent x-rays and the concentration of iodine contrast material. The use of high incident x-ray energy allows an increase in the signal to noise ratio by reducing the Compton scattering on the K(alpha) line.

Cerebrovascular events in inflammatory bowel disease patients treated with anti-tumour necrosis factor alpha agents.

PubMed

Karmiris, Konstantinos; Bossuyt, Peter; Sorrentino, Dario; Moreels, Tom; Scarcelli, Antonella; Legido, Jesus; Dotan, Iris; Naismith, Graham D; Jussila, Airi; Preiss, Jan C; Kruis, Wolfgang; Li, Andy C Y; Bouguen, Guillaume; Yanai, Henit; Steinwurz, Flavio; Katsanos, Konstantinos H; Subramaniam, Kavitha; Tarabar, Dino; Zaganas, Ioannis V; Ben-Horin, Shomron

2015-05-01

Cerebrovascular accidents [CVA] have rarely been reported in inflammatory bowel disease [IBD] patients treated with anti-tumour necrosis alpha [anti-TNF alpha] agents. Our aim here was to describe the clinical course of CVA in these patients. This was a European Crohn's and Colitis Organisation [ECCO] retrospective observational study, performed as part of the CONFER [COllaborative Network For Exceptionally Rare case reports] project. A call to all ECCO members was made to report on IBD patients afflicted with CVA during treatment with anti-TNF alpha agents. Clinical data were recorded in a standardised case report form and analysed for event association with anti-TNF alpha treatment. A total of 19 patients were identified from 16 centres: 14 had Crohn's disease, four ulcerative colitis and one IBD colitis unclassified [median age at diagnosis: 38.0 years, range: 18.6-62.5]. Patients received anti-TNF alpha for a median duration of 11.8 months [range: 0-62] at CVA onset; seven had previously been treated with at least one other anti-TNF alpha agent. Complete neurological recovery was observed in 16 patients. Anti-TNF alpha was discontinued in 16/19 patients. However, recurrent CVA or neurological deterioration was not observed in any of the 11 patients who received anti-TNF alpha after CVA [eight resumed after temporary cessation, three continued without interruption] for a median follow-up of 39.8 months [range: 5.6-98.2]. These preliminary findings do not unequivocally indicate a causal role of anti-TNF alpha in CVA complicating IBD. Resuming or continuing anti-TNF alpha in IBD patients with CVA may be feasible and safe in selected cases, but careful weighing of IBD activity versus neurological status is prudent. Copyright © 2015 European Crohn’s and Colitis Organisation (ECCO). Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Improved detection of radioactive material using a series of measurements

NASA Astrophysics Data System (ADS)

Mann, Jenelle

The goal of this project is to develop improved algorithms for detection of radioactive sources that have low signal compared to background. The detection of low signal sources is of interest in national security applications where the source may have weak ionizing radiation emissions, is heavily shielded, or the counting time is short (such as portal monitoring). Traditionally to distinguish signal from background the decision threshold (y*) is calculated by taking a long background count and limiting the false negative error (alpha error) to 5%. Some problems with this method include: background is constantly changing due to natural environmental fluctuations and large amounts of data are being taken as the detector continuously scans that are not utilized. Rather than looking at a single measurement, this work investigates looking at a series of N measurements and develops an appropriate decision threshold for exceeding the decision threshold n times in a series of N. This methodology is investigated for a rectangular, triangular, sinusoidal, Poisson, and Gaussian distribution.

Scaling Exponents in Financial Markets

NASA Astrophysics Data System (ADS)

Kim, Kyungsik; Kim, Cheol-Hyun; Kim, Soo Yong

2007-03-01

We study the dynamical behavior of four exchange rates in foreign exchange markets. A detrended fluctuation analysis (DFA) is applied to detect the long-range correlation embedded in the non-stationary time series. It is for our case found that there exists a persistent long-range correlation in volatilities, which implies the deviation from the efficient market hypothesis. Particularly, the crossover is shown to exist in the scaling behaviors of the volatilities.

Acid-base titration of melanocortin peptides: evidence of Trp rotational conformers interconversion.

PubMed

Fernandez, Roberto M; Vieira, Renata F F; Nakaie, Clóvis R; Lamy, M Teresa; Ito, Amando S

2005-01-01

Tryptophantime-resolved fluorescence was used to monitor acid-base titration properties of alpha-melanocyte stimulating hormone (alpha-MSH) and the biologically more potent analog [Nle4, D-Phe7]alpha -MSH (NDP-MSH), labeled or not with the paramagnetic amino acid probe 2,2,6,6-tetramthylpiperidine-N-oxyl-4-amino-4-carboxylic acid (Toac). Global analysis of fluorescence decay profiles measured in the pH range between 2.0 and 11.0 showed that, for each peptide, the data could be well fitted to three lifetimes whose values remained constant. The less populated short lifetime component changed little with pH and was ascribed to Trp g+ chi1 rotamer, in which electron transfer deactivation predominates over fluorescence. The long and intermediate lifetime preexponential factors interconverted along that pH interval and the result was interpreted as due to interconversion between Trp g- and trans chi1 rotamers, driven by conformational changes promoted by modifications in the ionization state of side-chain residues. The differences in the extent of interconversion in alpha-MSH and NDP-MSH are indicative of structural differences between the peptides, while titration curves suggest structural similarities between each peptide and its Toac-labeled species, in aqueous solution. Though less sensitive than fluorescence, the Toac electron spin resonance (ESR) isotropic hyperfine splitting parameter can also monitor the titration of side-chain residues located relatively far from the probe. Copyright (c) 2005 Wiley Periodicals, Inc.

Localization of Alpha-Keratin and Beta-Keratin (Corneous Beta Protein) in the Epithelium on the Ventral Surface of the Lingual Apex and Its Lingual Nail in the Domestic Goose (Anser Anser f. domestica) by Using Immunohistochemistry and Raman Microspectroscopy Analysis.

PubMed

Skieresz-Szewczyk, Kinga; Jackowiak, Hanna; Buchwald, Tomasz; Szybowicz, Mirosław

2017-08-01

The epithelium of the ventral surface of the apex of the tongue in most birds is specified by the presence of the special superficial layer called lingual nail. The aim of the present study is to determine the localization of the alpha-keratin and beta-keratin (corneous beta protein) in this special epithelium in the domestic goose by using immunohistochemistry staining and the Raman spectroscopy analysis. Due to lack of commercially available antibodies to detect beta-keratin (corneous beta protein), the Raman spectroscopy was used as a specific tool to detect and describe the secondary structure of proteins. The immunohistochemical (IHC) detections reveal the presence of alpha-keratin in all layers of the epithelium, but significant differences in the distribution of the alpha-keratin in the epithelial layers appear. The staining reaction is stronger from the basal layer to the upper zone of the intermediate layer. The unique result is weak staining for the alpha-keratin in the lingual nail. Applications of the Raman spectroscopy as a complementary method not only confirmed results of IHC staining for alpha-keratin, but showed that this technique could be used to demonstrate the presence of beta-keratin (corneous beta protein). Functionally, the localization of alpha-keratin in the epithelium of the ventral surface of the lingual apex provides a proper scaffold for epithelial cells and promotes structural integrity, whereas the presence of beta-keratin (corneous beta protein) in the lingual nail, described also as exoskeleton of the ventral surface of the apex, endures mechanical stress. Anat Rec, 300:1361-1368, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Aib and iva in the biosphere: neither rare nor necessarily extraterrestrial.

PubMed

Brückner, Hans; Becker, Dieter; Gams, Walter; Degenkolb, Thomas

2009-01-01

Fourty-nine species and strains of filamentous fungi of the genera Acremonium, Bionectria, Clonostachys, Emericellopsis, Hypocrea/Trichoderma, Lecythophora, Monocillium, Nectriopsis, Niesslia, Tolypocladium, and Wardomyces, deposited with the culture collection of the Centraalbureau voor Schimmelcultures (CBS) in Utrecht, The Netherlands, were grown on nutrient agar plates. Organic extracts of mycelia were analyzed after acidic total hydrolysis and derivatization by GC/SIM-MS on Chirasil-L-Val for the presence of Aib (=alpha-aminoisobutyric acid, 2-methylalanine) and DL-Iva (=isovaline, 2-ethylalanine). In 37 of the hydrolysates, Aib was detected, and in several of them D-Iva or mixtures of D- and L-Iva. Non-proteinogenic Aib, in particular, is a highly specific marker for a distinctive group of fungal polypeptides named peptaibols or, comprehensively, peptaibiotics, i.e., peptides containing Aib and displaying (anti)biotic activities. The biotic synthesis of these amino acids by filamentous fungi contradicts the still widespread belief that alpha,alpha-dialkyl-alpha-amino acids do not or rarely occur in the biosphere and, if detected, are of extraterrestrial origin. The abundant production of peptaibiotics by cosmopolitan species of microfungi has also to be considered in the discussion on the occurrence of Aib and Iva in ancient and recent sediments. The detection of trace amounts of Aib in ice samples of Antarctica that are devoid of meteorites might also be related to the presence of Aib-producing microorganisms, being either indigenous psychrophiles, or being transported and localized by mechanisms related to bioaerosols and cryoconites. The presence of microfungi being capable of producing alpha,alpha-dialkyl alpha-amino acids in terrestrial samples, and possible contamination of extraterrestrial materials are pointed out to be of relevance for the reliable interpretation of cosmogeochemical data.

A 3,387 bp 5'-flanking sequence of the goat alpha-S1-casein gene provides correct tissue-specific expression of human granulocyte colony-stimulating factor (hG-CSF) in the mammary gland of transgenic mice.

PubMed

Serova, Irina A; Dvoryanchikov, Gennady A; Andreeva, Ludmila E; Burkov, Ivan A; Dias, Luciene P B; Battulin, Nariman R; Smirnov, Alexander V; Serov, Oleg L

2012-06-01

A new expression vector containing the 1,944 bp 5'-flanking regulatory region together with exon 1 and intron 1 of the goat alpha-S1-casein gene (CSN1S1), the full-sized human granulocyte colony-stimulating factor gene (hGCSF) and the 3'-flanking sequence of the bovine CSN1S1, was created. The vector DNA was used for generation of four mouse transgenic lines. The transgene was integrated into chromosomes 8 and 12 of two founders as 2 and 5 copies, respectively. Tissue-specific secretion of hG-CSF into the milk of transgenic mice was in the range of 19-40 μg/ml. RT-PCR analysis of various tissues of the transgenic mice demonstrated that expression of hGCSF was detected in only the mammary gland in the progeny of all founders. Moreover, cells were shown to be positive for hG-CSF by immunofluorescent analysis in the mammary glands but not in any other tissues. There were no signs of mosaic expression in the mammary gland. Trace amounts of hG-CSF were detected in the serum of females of two transgenic lines during lactation only. However, no transgenic mice showed any changes in hematopoiesis based on the number of granulocytes in blood. Immunoblotting of hG-CSF in the milk of transgenic mice revealed two forms, presumably the glycosylated and non-glycosylated forms. The hematopoietic activity of hG-CSF in the milk of transgenic females is comparable to that of recombinant G-CSF. In general, the data obtained in this study show that the new expression vector is able to provide correct tissue-specific expression of hG-CSF with high biological activity in transgenic mice.

Many-body localization in a long range XXZ model with random-field

NASA Astrophysics Data System (ADS)

Li, Bo

2016-12-01

Many-body localization (MBL) in a long range interaction XXZ model with random field are investigated. Using the exact diagonal method, the MBL phase diagram with different tuning parameters and interaction range is obtained. It is found that the phase diagram of finite size results supplies strong evidence to confirm that the threshold interaction exponent α = 2. The tuning parameter Δ can efficiently change the MBL edge in high energy density stats, thus the system can be controlled to transfer from thermal phase to MBL phase by changing Δ. The energy level statistics data are consistent with result of the MBL phase diagram. However energy level statistics data cannot detect the thermal phase correctly in extreme long range case.

Antiobesity effects and improvement of insulin sensitivity by 1-deoxynojirimycin in animal models.

PubMed

Kong, Won-Ho; Oh, Seung-Hoon; Ahn, You-Ran; Kim, Kwang-Won; Kim, Jin-Hoon; Seo, Soo-Won

2008-04-23

The alpha-glucosidase inhibitor 1-deoxynojirimycin (DNJ) is one of the simplest naturally occurring carbohydrate mimics, with promising biological activity in vivo. Although there is considerable interest in the pharmacological effects of DNJ, the antidiabetic effects of DNJ in type 2 diabetes mellitus have received little attention. In this work, DNJ was isolated from the silkworm (Bombyx mori), and its antidiabetic effects were evaluated in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, an established animal model of human type 2 diabetes mellitus, and in control Long-Evans Tokushima Otsuka (LETO) rats. DNJ treatment showed significant antidiabetic effects in OLETF rats, with significant improvements in fasting blood glucose levels and glucose tolerance and, especially, increased insulin sensitivity. Furthermore, there was significant loss of body weight in both groups. DNJ also showed significant antihyperglycemic effects in streptozotocin- and high-fat-diet-induced hyperglycemic rats. Its efficacy and dose profiles were better than those of acarbose, a typical alpha-glucosidase inhibitor in clinical use. Furthermore, a substantial fraction of DNJ was absorbed into the bloodstream within a few minutes of oral administration. DNJ was also detected in the urine. These findings suggest that its postprandial hypoglycemic effect in the gastrointestinal tract is a possible but insufficient mechanism of action underlying the antidiabetic effects of DNJ. Its antiobesity effect and improvement of insulin sensitivity are other possible antidiabetic effects of DNJ.

NASA science utilization plans for the Space Station.

PubMed

Reeves, E M; Cressy, P J

1995-10-01

The Mir-1 and International Space Station Alpha capabilities present the science community with unique long duration platforms to conduct a wide range of scientific research in the microgravity and life sciences as well as in the observational sciences, NASA is developing plans to use the capabilities of Mir and Space Station as they emerge during the development of the orbital program. In both cases the planned science utilization programs take advantage of the volume, crew, power, microgravity and logistics resupply unique to each phase. The paper will present these utilization plans in the context of an evolving scientific program.

Detection of Lyman-alpha emission from the Saturnian disk and from the ring system

NASA Technical Reports Server (NTRS)

Weiser, H.; Vitz, R. C.; Moos, H. W.

1977-01-01

A rocket-borne spectrograph detected H I Lyman-alpha emission from the disk of Saturn and from the vicinity of the planet. The signal is consistent with an emission brightness of 700 rayleighs for the disk and 200 rayleighs for the vicinity of Saturn. The emission from the vicinity of the planet may be due to a hydrogen atmosphere associated with the Saturnian ring system.

Utilization of wavelength-shifting fibers coupled to ZnS(Ag) and plastic scintillator for simultaneous detection of alpha/beta particles

NASA Astrophysics Data System (ADS)

Ifergan, Y.; Dadon, S.; Israelashvili, I.; Osovizky, A.; Gonen, E.; Yehuda-Zada, Y.; Smadja, D.; Knafo, Y.; Ginzburg, D.; Kadmon, Y.; Cohen, Y.; Mazor, T.

2015-06-01

Low level radioactive surface contamination measurements require lightweight, large area and high efficiency detector. In most existing scintillation detectors there is a tradeoff between effective area and scintillation light collection. By using wavelength shifting (WLS) fibers the scintillation light may be collected efficiently also in a large area detector. In this study, WLS fibers were coupled to a beta sensitive plastic scintillator layer and to a alpha sensitive silver-activated zinc sulfide ZnS(Ag) layer for detecting both alpha and beta particles. The WLS fibers collect the scintillation light from the whole detector and transfer it to a single PMT. This first prototype unique configuration enables monitoring radioactive contaminated surfaces by both sides of the detector and provides high gamma rejection. In this paper, the detector structure, as well as the detector's measured linear response, will be described. The measured detection efficiency of 238Pu alpha particles (5.5 MeV) is 63%. The measured detection efficiency for beta particles is 89% for 90Sr-90Y (average energy of 195.8 keV, 934.8 keV), 50% for 36Cl (average energy of 251.3 keV), and 35% for 137Cs (average energy of 156.8 keV).

Liquid Phase Deposition of Single-Phase Alpha-Copper-Indium-Diselenide

NASA Technical Reports Server (NTRS)

Hepp, Aloysius F.; Bailey, S.; Cowen, Jonathan; Lucas, L.; Ernst, Frank; Pirouz, P.

2004-01-01

The success of exploratory missions in outer space often depends on a highly efficient renewable energy supply, as provided by solar cells. Since future missions will demand large aggregates of solar cells, and space flight is expensive, the solar cells must furthermore be available at low costs and have a long lifetime and high resistance against structural damage introduced by irradiation with high energy electrons and protons. The photovoltaic materials that are presently available only partly fulfill all these requirements. Therefore, we propose to explore a new method for fabricating thin-films for cost-efficient solar cells with very high specific power,high irradiation resistance and long lifetime based on the alpha-phase of the Cu-In-Se system "alpha-CIS."

Minisatellite and Hprt mutations in V79 cells irradiated with helium ions and gamma rays.

PubMed

Cherubinit, R; Canova, S; Favaretto, S; Bruna, V; Battivelli, P; Celotti, L

2002-09-01

To evaluate and compare cytotoxic and mutational effects of graded doses of gamma-rays and 4He++ ions at different LET values (nominally 80 and 123 keV/microm) in V79 cells. 4He++ ion beams at 80 and 123 keV/microm were supplied by the 7 MV Van de Graaff CN accelerator of the INFN-LNL in the dose range 0.3 2.4 Gy at a dose rate of 1 Gy/min. Gamma-irradiation was performed by the 60Co 'gamma beam' of CNR-FRAE (at the INFN-LNL) in the dose range 0.5 6.0 Gy at a dose rate of 1 Gy/min. After irradiation, the cells were seeded to measure surviving fraction (SF) and mutant frequency (MF) at the Hprt locus on the basis of 6-thioguanine resistance. Alterations at minisatellite sequences (MS) of clones derived from irradiated and unirradiated cells were detected by Southern blot analysis using a multi-locus probe (DNA fingerprinting). Survival data from 4He++ irradiation at two LET values (80 and 123 keV/microm) yielded similar results: alpha = (1.08 +/- 0.04)/Gy and (0.90 +/- 0.03)/Gy, respectively. The best fit for mutant induction at the Hprt locus after 80keV/microm 4He++ was a linear function of the dose in the dose-interval 0-1.5 Gy: alpha= (47.77 +/- 16.01) x 10(-6)/Gy. The best fit for mutant induction after 123 keV/microm 4He++ in the dose-interval 0-1.2 Gv was a linear-quadratic function: alpha=(86.01 +/- 13.80) x 10(-6)/Gy; beta = (42.87 +/- 11.03) x 10(-6)/Gy2. For gamma-irradiation, the best fit of Hprt mutation data gave: alpha = (4.14+2.67)x 10(-6)/Gy: beta = (0.63 +/- 0.86) x 10(-6)/Gy2. The best fitting of MS alteration data with linear-quadratic or linear relationships gave: for gamma-rays, alpha = 0.56 mutants/Gy and beta = 0.52 mutants/Gy2; for 80 keV/microm 4He++, alpha = 3.70 mutants/Gy and beta = 9.00 mutants/Gy2; for 123keV/microm 4He++, alpha = 4.36 mutants/Gy. The results reported here confirmed the higher cytotoxic and mutagenic effects of helium ions in comparison with gamma-irradiation and the ability of DNA fingerprint analysis to investigate DNA damage induced by different ionizing radiations. The results of the mutagenic effects measured by the two tests are in agreement.

A rapid method for identification and quantification of prostaglandins in cerebral tissues by UHPLC-ESI-MS/MS for the lipidomic in vivo studies.

PubMed

Gobo, Luciana Assis; de Carvalho, Leandro Machado; Temp, Fernanda; Viana, Carine; Mello, Carlos Fernando

2018-03-15

An analytical method utilizing liquid chromatography coupled to mass spectrometry with electrospray ionization has been developed for the identification of prostaglandins (PGs) in cerebral tissues. The five compounds identified (thromboxane B2, prostaglandin E2, prostaglandin D2, 6-keto-prostaglandin F1 alpha and prostaglandin F2 alpha) are cellular mediators of inflammation and are involved in a variety of physiological and pathological processes by acting on membrane receptors on the surfaces of target cells. The parameters of the electrospray ionization interface were optimized to obtain the highest possible sensitivity for all compounds studied. The limits of detection ranged from 0.25 to 1.09 μg L -1 , and the limits of quantification ranged from 0.83 to 3.64 μg L -1 . The method was validated and applied to samples of brain tissue from five mice. The sample concentrations of the four prostaglandins quantified ranged from 375 ȵg L -1 for prostaglandin E2 to 6602 μg L -1 for prostaglandin D2. An advantage of this work that should be emphasized is the fast response of the method, which allows to obtaining the lipid profile after a 3 min chromatographic run. Copyright © 2018 Elsevier Inc. All rights reserved.

Molecular cloning and expression analysis of sea bass (Dicentrarchus labrax L.) tumor necrosis factor-alpha (TNF-alpha).

PubMed

Nascimento, Diana S; Pereira, Pedro J B; Reis, Marta I R; do Vale, Ana; Zou, Jun; Silva, Manuel T; Secombes, Christopher J; dos Santos, Nuno M S

2007-09-01

In the search for pro-inflammatory genes in sea bass a TNF-alpha gene was cloned and sequenced. The sea bass TNF-alpha (sbTNF-alpha) putative protein conserves the TNF-alpha family signature, as well as the two cysteines usually involved in the formation of a disulfide bond. The mouse TNF-alpha Thr-Leu cleavage sequence and a potential transmembrane domain were also found, suggesting that sbTNF-alpha exists as two forms: a approximately 28 kDa membrane-bound form and a approximately 18.4 kDa soluble protein. The single copy sbTNF-alpha gene contains a four exon-three intron structure similar to other known TNF-alpha genes. Homology modeling of sbTNF-alpha is compatible with the trimeric quaternary architecture of its mammalian counterparts. SbTNF-alpha is constitutively expressed in several unstimulated tissues, and was not up-regulated in the spleen and head-kidney, in response to UV-killed Photobacterium damselae subsp. piscicida. However, an increase of sbTNF-alpha expression was detected in the head-kidney during an experimental infection using the same pathogen.

Dynamic radioactive particle source

DOEpatents

Moore, Murray E; Gauss, Adam Benjamin; Justus, Alan Lawrence

2012-06-26

A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

Cytoskeleton changes following differentiation of N1E-115 neuroblastoma cell line.

PubMed

Oh, J-E; Karlmark Raja, K; Shin, J-H; Pollak, A; Hengstschläger, M; Lubec, G

2006-10-01

No systematic approach to detect expression of differentiation-related elements was published so far. The undifferentiated N1E-115 neuroblastoma cell line was switched into a neuronal phenotype by DMSO treatment and used for proteomic experiments. We used two-dimensional gel electrophoresis followed by unambiguous mass spectrometrical identification of proteins to generate a map of cytoskeleton proteins (CPs), i.e., to search for differentiation-related structures. Alpha-actin, actin-like protein 6A, gamma-tubulin complex component 2, tubulin alpha 3/alpha 7, CLIP associating protein 2, B4 integrin interactor homolog were detectable in the undifferentiated cell line exclusively and neuron-specific CPs drebrin and presynaptic density protein 95, actin-related protein 2/3, alpha and beta-centractin, PDZ-domain actin binding protein, actinin alpha 1, profilin II, ezrin, coactosin-like protein, transgelin 2, myosin light polypeptide 6, tubulin alpha 2, 6 and 7, beta tubulin (94% similar with tubulin beta-2), tubulin beta 3, tubulin tyrosine ligase-like protein 1, lamin B1 and keratin 20 were observed in the differentiated cell line only. We herein identified differentiation-related expressional patterns thus providing new evidence for the role of CPs in the process of neuronal differentiation.

Vascular endothelial cells express isoforms of protein kinase A inhibitor.

PubMed

Lum, Hazel; Hao, Zengping; Gayle, Dave; Kumar, Priyadarsini; Patterson, Carolyn E; Uhler, Michael D

2002-01-01

The expression and function of the endogenous inhibitor of cAMP-dependent protein kinase (PKI) in endothelial cells are unknown. In this study, overexpression of rabbit muscle PKI gene into endothelial cells inhibited the cAMP-mediated increase and exacerbated thrombin-induced decrease in endothelial barrier function. We investigated PKI expression in human pulmonary artery (HPAECs), foreskin microvessel (HMECs), and brain microvessel endothelial cells (HBMECs). RT-PCR using specific primers for human PKI alpha, human PKI gamma, and mouse PKI beta sequences detected PKI alpha and PKI gamma mRNA in all three cell types. Sequencing and BLAST analysis indicated that forward and reverse DNA strands for PKI alpha and PKI gamma were of >96% identity with database sequences. RNase protection assays showed protection of the 542 nucleotides in HBMEC and HPAEC PKI alpha mRNA and 240 nucleotides in HBMEC, HPAEC, and HMEC PKI gamma mRNA. Western blot analysis indicated that PKI gamma protein was detected in all three cell types, whereas PKI alpha was found in HBMECs. In summary, endothelial cells from three different vascular beds express PKI alpha and PKI gamma, which may be physiologically important in endothelial barrier function.

Ultraviolet Imaging Spectrometer

NASA Technical Reports Server (NTRS)

Wdowiak, T. J.

1993-01-01

Wide-field imaging systems equipped with objective prisms or gratings have had a long history of utility in groundbased observations of meteors and comets. Deployment of similar instruments from low Earth orbit would allow the first UV observations of meteors. This instrument can be used for comets and Lyman alpha coronae of Earth-orbit-crossing asteroids. A CaF2 prism imaging spectrograph designed for stellar observations was used aboard Skylab to observe Comet Kohoutek (1973f), but its 1300-A cut-off precluded Lyman alpha images and it was not used for observation of meteors. Because the observation of the UV spectrum of a meteor has never been attempted, researchers are denied the opportunity to obtain composition information from spectra at those wavelengths. We propose construction of a flight instrument functioning in the 1100-3200 A spectral range that is suitable for a dedicated satellite ('Quick Star') or as a space-station-attached payload. It can also be an autonomous package in the space shuttle cargo bay.

Optical detection of radon decay in air

PubMed Central

Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Toivonen, Harri; Toivonen, Juha

2016-01-01

An optical radon detection method is presented. Radon decay is directly measured by observing the secondary radiolumines cence light that alpha particles excite in air, and the selectivity of coincident photon detection is further enhanced with online pulse-shape analysis. The sensitivity of a demonstration device was 6.5 cps/Bq/l and the minimum detectable concentration was 12 Bq/m3 with a 1 h integration time. The presented technique paves the way for optical approaches in rapid radon detec tion, and it can be applied beyond radon to the analysis of any alpha-active sample which can be placed in the measurement chamber. PMID:26867800

A New Conjugation Method Used for the Development of an Immunoassay for the Detection of Amanitin, a Deadly Mushroom Toxin.

PubMed

Bever, Candace S; Barnych, Bogdan; Hnasko, Robert; Cheng, Luisa W; Stanker, Larry H

2018-06-28

One of the deadliest mushrooms is the death cap mushroom, Amanita phalloides . The most toxic constituent is α-amanitin, a bicyclic octapeptide, which damages the liver and kidneys. To develop a new tool for detecting this toxin, polyclonal antibodies were generated and characterized. Both α- and β-amanitin were coupled to carrier proteins through four different linking chemistries, one of which has never before been described. These conjugates were evaluated for their effectiveness in generating antibodies specific for the free toxin, as well as their utility in formatting heterogeneous assays with high sensitivity. Ultimately, these efforts yielded a newly described conjugation procedure utilizing periodate oxidation followed by reductive amination that successfully resulted in generating sensitive immunoassays (limit of detection (LOD), ~1.0 µg/L). The assays were characterized for their selectivity and were found to equally detect α-, β-, and γ-amanitin, and not cross-react with other toxins tested. Toxin detection in mushrooms was possible using a simple sample preparation method. This enzyme-linked immunosorbent assay (ELISA) is a simple and fast test, and readily detects amatoxins extracted from A. phalloides .

Defense Coastal/Estuarine Research Program (DCERP)

DTIC Science & Technology

2007-09-19

area, determined by the North Carolina Division of Coastal Management from 1938 to 1992, and LIDAR data suggests that there is not a strong...spectrometry KBDI Keetch-Byram drought index LCAC landing craft air cushion LIDAR Light Detection and Ranging LTSC Long-Term Shoreline Change LVORI low...that the frequency distribution of marsh elevations relative to mean sea level, determined by analysis of Light Detection and Ranging ( LIDAR ) data, is

Development of a label-free gold nanoparticle-based colorimetric aptasensor for detection of human estrogen receptor alpha.

PubMed

Ahirwar, Rajesh; Nahar, Pradip

2016-01-01

The increasing demand for easily available and low-cost diagnostics has fuelled the development of aptasensors as platforms for rapid, sensitive, and point-of-care testing of target analytes. Recently, gold nanoparticle (AuNP)-based aptasensors have attracted wide recognition owing to their color transition properties which allow real-time rapid sensing of targets. In this study, we utilized the color transition property of aptamer-functionalized AuNPs to detect and quantify estrogen receptor alpha (ERα), a key biomarker protein in breast cancer. We found that the coating of AuNPs with unmodified ERα-RNA aptamer (GGGGUCAAGGUGACCCC) makes them resistant to salt-induced aggregation. However, addition of ERα to the aptamer-protected AuNPs results in their spontaneous aggregation as evident from a color transition from wine red to deep blue. On the basis of this, we developed an ERα aptasensor, with limits of detection and quantification of 0.64 and 2.16 ng/mL, respectively; the aptasensor can efficiently detect and quantify ERα in a working range of 10 ng/mL-5μg/mL protein. Validation of the aptasensor on cellular extracts of ERα-positive MCF-7 and ERα-deficient MDA-MB-231 breast cancer cells showed a target-selective response in ERα-positive samples but not in cellular extracts of ERα-deficient breast cancer cells. Further, the small size and simple fabrication chemistry of aptamers provide an additional benefit to make the ERα aptasensor a potentially useful and cost-effective tool in point-of-care analyses of ERα.

Intra- and intercompartmental associations between levels of organochlorines in maternal plasma, cord plasma and breast milk, and lead and cadmium in whole blood, for indigenous peoples of Chukotka, Russia.

PubMed

Eik Anda, E; Nieboer, E; Dudarev, A A; Sandanger, T M; Odland, J Ø

2007-08-01

Long-range transport of pollutants towards circumpolar regions emphasizes the need for up-to-date and reliable biological monitoring data. This paper explores the use, reliability and availability of maternal blood (MB) and plasma (MP), cord blood (CB) and plasma (CP) and mother's milk (MM) in terms of assessing exposure to persistent toxic substances (PTSs). It is concluded that MP has the best combination of availability, sensitivity in terms of number of PTSs, their detection frequency and concentrations, and physiological relevance. The study group consisted of 48 pregnant women of indigenous origin from the Chuchki district in the eastern Russian arctic. Blood, CB and MM specimens were collected from all women and MP, CP and MM were analyzed for the Arctic Monitoring and Assessment Programme (AMAP) suite of organochlorines (OCs) and metals (Pb and Cd in MB and CB). Generally speaking, the levels of PTSs coincided with those indicated in several AMAP publications from Chukotka and other areas of northern Russia. The correlations of PTS concentrations between the three body fluid compartments exceeded the minimum statistical requirements of alpha = 0.05 and beta = 0.20 for most of the compounds, with r > 0.46 except for Cd (r = 0.05); lipid adjustments for the OCs did not affect the r-values to any significant extent. The majority of the inter-OC correlations within compartments also fulfilled the indicated statistical condition. Careful consideration is given to the replacement of concentrations below the detection limit, OC detection frequency, the criteria for log-transformation of the data, analytical uncertainty, and biological variability. Practical implications of the findings are explored.

Serum IgG, IgM and slow alpha-globulin levels in carrageenan-treated rats.

PubMed Central

Fowler, E. F.; Thomson, A. W.

1979-01-01

Serum levels of IgM, IgG, slow alpha 1- and slow alpha 2-globulins were measured either by quantitative radial immunodiffusion (IgG) or immunoelectrophoresis (IgM and slow alpha-globulins) during the 3-week period after i.p. injection of 50 mg potassium carrageenan. There was a significant elevation in levels of IgM and slow alpha 1-globulin, maximal on Day 4 and returning to normal by Day 14. Slow alpha 2-globulin was detectable within 24 h, reached a peak at Day 2, and was no longer measurable in most rats by Day 14. Levels of IgG however, were unaffected by carrageenan injection. PMID:92333

THE SEGUE STELLAR PARAMETER PIPELINE. V. ESTIMATION OF ALPHA-ELEMENT ABUNDANCE RATIOS FROM LOW-RESOLUTION SDSS/SEGUE STELLAR SPECTRA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Young Sun; Beers, Timothy C.; Prieto, Carlos Allende

We present a method for the determination of [{alpha}/Fe] ratios from low-resolution (R = 2000) SDSS/SEGUE stellar spectra. By means of a star-by-star comparison with degraded spectra from the ELODIE spectral library and with a set of moderately high-resolution (R = 15, 000) and medium-resolution (R = 6000) spectra of SDSS/SEGUE stars, we demonstrate that we are able to measure [{alpha}/Fe] from SDSS/SEGUE spectra (with S/N>20/1) to a precision of better than 0.1 dex, for stars with atmospheric parameters in the range T{sub eff} = [4500, 7000] K, log g = [1.5, 5.0], and [Fe/H] = [-1.4, +0.3], over themore » range [{alpha}/Fe] = [-0.1, +0.6]. For stars with [Fe/H] <-1.4, our method requires spectra with slightly higher signal-to-noise to achieve this precision (S/N>25/1). Over the full temperature range considered, the lowest metallicity star for which a confident estimate of [{alpha}/Fe] can be obtained from our approach is [Fe/H] {approx}-2.5; preliminary tests indicate that a metallicity limit as low as [Fe/H] {approx}-3.0 may apply to cooler stars. As a further validation of this approach, weighted averages of [{alpha}/Fe] obtained for SEGUE spectra of likely member stars of Galactic globular clusters (M15, M13, and M71) and open clusters (NGC 2420, M67, and NGC 6791) exhibit good agreement with the values of [{alpha}/Fe] from previous studies. The results of the comparison with NGC 6791 imply that the metallicity range for the method may extend to {approx}+0.5.« less

Intercomparison of retrospective radon detectors.

PubMed Central

Field, R W; Steck, D J; Parkhurst, M A; Mahaffey, J A; Alavanja, M C

1999-01-01

We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, (210)Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha-emission of a (210)Pb-decay product, (210)Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface alpha-activity. In the absence of other strong sources of alpha-emission in the glass, the implanted surface alpha-activity should be proportional to the accumulated (210)Po, and hence to the cumulative radon gas exposure. The goals of the intercomparison were to a) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, b) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass-implanted polonium activities, and c) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted (210)Po activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type. Preliminary comparisons of the models used to translate track rate densities to average long-term radon concentrations differ between the two studies. Further calibration of the retrospective detectors' models for interpretation of track rate density may allow the pooling of studies that use glass-based retrospective radon detectors to determine historic residential radon exposures. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10545336

Intercomparison of retrospective radon detectors.

PubMed

Field, R W; Steck, D J; Parkhurst, M A; Mahaffey, J A; Alavanja, M C

1999-11-01

We performed both a laboratory and a field intercomparison of two novel glass-based retrospective radon detectors previously used in major radon case-control studies performed in Missouri and Iowa. The new detectors estimate retrospective residential radon exposure from the accumulation of a long-lived radon decay product, (210)Pb, in glass. The detectors use track registration material in direct contact with glass surfaces to measure the alpha-emission of a (210)Pb-decay product, (210)Po. The detector's track density generation rate (tracks per square centimeter per hour) is proportional to the surface alpha-activity. In the absence of other strong sources of alpha-emission in the glass, the implanted surface alpha-activity should be proportional to the accumulated (210)Po, and hence to the cumulative radon gas exposure. The goals of the intercomparison were to a) perform collocated measurements using two different glass-based retrospective radon detectors in a controlled laboratory environment to compare their relative response to implanted polonium in the absence of environmental variation, b) perform collocated measurements using two different retrospective radon progeny detectors in a variety of residential settings to compare their detection of glass-implanted polonium activities, and c) examine the correlation between track density rates and contemporary radon gas concentrations. The laboratory results suggested that the materials and methods used by the studies produced similar track densities in detectors exposed to the same implanted (210)Po activity. The field phase of the intercomparison found excellent agreement between the track density rates for the two types of retrospective detectors. The correlation between the track density rates and direct contemporary radon concentration measurements was relatively high, considering that no adjustments were performed to account for either the residential depositional environment or glass surface type. Preliminary comparisons of the models used to translate track rate densities to average long-term radon concentrations differ between the two studies. Further calibration of the retrospective detectors' models for interpretation of track rate density may allow the pooling of studies that use glass-based retrospective radon detectors to determine historic residential radon exposures.