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1

(re)producing Good Science Students: Girls' Participation in High School Physics  

NASA Astrophysics Data System (ADS)

In this ethnographic study, the author describes the meanings of science and science student in a physics classroom in an upper-middle-class high school and the ways girls participated within these meanings. The classroom practices reproduced prototypical meanings of science (as authoritative) and science student (as "dutiful"). The results highlight girls' embrace of prototypical school science. Yet at the end of the school year, the girls did not consider themselves "science people," nor did they want to pursue physics further. The author's interpretation of these results takes seriously girls' agency in producing the meaning of the physics class (as a way to polish one's transcript) and draws attention to the promoted identities (prototypical good student identities) in the classroom. The author argues that students' agency in resisting or accepting the practices, identities, and knowledge of school science is worth understanding for the improvement of science education.

Carlone, Heidi B.

2

Highly reliable field electron emitters produced from reproducible damage-free carbon nanotube composite pastes with optimal inorganic fillers.  

PubMed

Highly reliable field electron emitters were developed using a formulation for reproducible damage-free carbon nanotube (CNT) composite pastes with optimal inorganic fillers and a ball-milling method. We carefully controlled the ball-milling sequence and time to avoid any damage to the CNTs, which incorporated fillers that were fully dispersed as paste constituents. The field electron emitters fabricated by printing the CNT pastes were found to exhibit almost perfect adhesion of the CNT emitters to the cathode, along with good uniformity and reproducibility. A high field enhancement factor of around 10,000 was achieved from the CNT field emitters developed. By selecting nano-sized metal alloys and oxides and using the same formulation sequence, we also developed reliable field emitters that could survive high-temperature post processing. These field emitters had high durability to post vacuum annealing at 950 °C, guaranteeing survival of the brazing process used in the sealing of field emission x-ray tubes. We evaluated the field emitters in a triode configuration in the harsh environment of a tiny vacuum-sealed vessel and observed very reliable operation for 30 h at a high current density of 350 mA cm(-2). The CNT pastes and related field emitters that were developed could be usefully applied in reliable field emission devices. PMID:24434798

Kim, Jae-Woo; Jeong, Jin-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

2014-02-14

3

Reproducible High Yields of Recombinant Adeno-Associated Virus Produced Using Invertebrate Cells in 0.02- to 200-Liter Cultures  

PubMed Central

Abstract The large amounts of recombinant adeno-associated virus (rAAV) vector needed for clinical trials and eventual commercialization require robust, economical, reproducible, and scalable production processes compatible with current good manufacturing practice. rAAV produced using baculovirus and insect cells satisfies these conditions; however, recovering rAAV particles from 200-liter bioreactors is more complicated than bench-scale vector preparations. Using a variety of processing media, we developed a reliable and routine downstream procedure for rAAV production that is scalable from 0.02- to 200-liter cultures. To facilitate the upstream process, we adapted the titerless infected-cell preservation and scale-up process for rAAV production. Single-use aliquots of cryopreserved baculovirus-infected insect cells (BIIC) are thawed and added to the suspension culture to achieve the desired ratio of BIIC to rAAV-producer cells. By using conditions established with small-scale cultures, rAAV was produced in larger volume cultures. Strikingly consistent rAAV yields were attained in cultures ranging from 10 liters to 200 liters. Based on the final yield, each cell produced 18,000?±?6,800 particles of purified rAAV in 10-, 20-, 100-, and 200-liter cultures. Thus, with an average cell density of 4.32?×?106 cells/ml, ?1016 purified rAAV particles are produced from 100 to 200 liters. The downstream process resulted in about 20% recovery estimated from comparing the quantities of capsid protein antigen in the crude bioreactor material and in the final, purified product. The ease and reproducibility of rAAV production in 200-liter bioreactors suggest that the limit has not been reached, and 500-liter productions are planned.

Cecchini, Sylvain; Virag, Tamas

2011-01-01

4

Reproducible high yields of recombinant adeno-associated virus produced using invertebrate cells in 0.02- to 200-liter cultures.  

PubMed

The large amounts of recombinant adeno-associated virus (rAAV) vector needed for clinical trials and eventual commercialization require robust, economical, reproducible, and scalable production processes compatible with current good manufacturing practice. rAAV produced using baculovirus and insect cells satisfies these conditions; however, recovering rAAV particles from 200-liter bioreactors is more complicated than bench-scale vector preparations. Using a variety of processing media, we developed a reliable and routine downstream procedure for rAAV production that is scalable from 0.02- to 200-liter cultures. To facilitate the upstream process, we adapted the titerless infected-cell preservation and scale-up process for rAAV production. Single-use aliquots of cryopreserved baculovirus-infected insect cells (BIIC) are thawed and added to the suspension culture to achieve the desired ratio of BIIC to rAAV-producer cells. By using conditions established with small-scale cultures, rAAV was produced in larger volume cultures. Strikingly consistent rAAV yields were attained in cultures ranging from 10 liters to 200 liters. Based on the final yield, each cell produced 18,000 ± 6,800 particles of purified rAAV in 10-, 20-, 100-, and 200-liter cultures. Thus, with an average cell density of 4.32 × 10(6) cells/ml, ? 10(16) purified rAAV particles are produced from 100 to 200 liters. The downstream process resulted in about 20% recovery estimated from comparing the quantities of capsid protein antigen in the crude bioreactor material and in the final, purified product. The ease and reproducibility of rAAV production in 200-liter bioreactors suggest that the limit has not been reached, and 500-liter productions are planned. PMID:21381980

Cecchini, Sylvain; Virag, Tamas; Kotin, Robert M

2011-08-01

5

Photochemically-induced ischemia of the rat sciatic nerve produces a dose-dependent and highly reproducible mechanical, heat and cold allodynia, and signs of spontaneous pain.  

PubMed

Sensory abnormalities and changes in spontaneous behavior were examined after a photochemically induced ischemic lesion of the rat sciatic nerve. Male adult rats were anesthetized and the sciatic nerve was exposed. After the intravenous injection of a photosensitizing dye, erythrosin B, the exposed nerve was irradiated just proximal to the nerve trifurcation with light from an argon laser. Three different irradiation times were used, 30 s, 1 and 2 min. In sham-operated rats, the exposed sciatic nerve was irradiated for 2 min without prior injection of the erythrosin B. Rats were tested for the presence of mechanical, cold and heat allodynia or hyperalgesia. All the animals in the 1- and 2-min irradiation groups developed mechanical, cold and heat allodynia after nerve irradiation. A significant dose-dependent effect of laser exposure time was observed for all modalities tested (2 min > 1 min > 30 s = sham). The maximum effects were observed at 3 and 7 days postirradiation and remained present for up to 10 weeks. No significant contralateral effects were observed in any of the groups. In three separate groups of rats (1, 2 and 4 min of laser exposure), the presence of possible signs of spontaneous pain (paw shaking, paw elevation and freezing behavior) was tested. A significant and exposure time-dependent increase in spontaneous paw elevation and paw shaking was observed which was maximal at week 1, but resolved at 4 weeks (4 min > 2 min > 1 min > sham). In addition, animals in all ischemic groups, but not in the sham group, showed a significant increase in freezing behavior up to 4 weeks after nerve irradiation. Light microscopic evaluation of nerves removed 7 days post-irradiation, i.e. when maximal allodynia was observed, showed clear evidence of demyelination of large myelinated fibers. These data indicate that photochemically-induced peripheral nerve ischemia is associated with abnormal pain-related behaviors, including mechanical, thermal and cold allodynia and signs of spontaneous pain. The incidence and severity of the behavioral changes are clearly dependent on the exposure time and are probably due to, at least in part, a demyelinaton. These results partly confirm previous data using a similar technique and suggest that this may represent a new animal model for peripheral neuropathy of ischemic origin. The advantages of the present model are its good reproducibility and the fact that the nerve injury can be easily quantified and graded. PMID:9696458

Kupers, R; Yu, W; Persson, J K; Xu, X J; Wiesenfeld-Hallin, Z

1998-05-01

6

Reproducible, high performance patch antenna array apparatus and method of fabrication  

DOEpatents

A reproducible, high-performance patch antenna array apparatus includes a patch antenna array provided on a unitary dielectric substrate, and a feed network provided on the same unitary substrate and proximity coupled to the patch antenna array. The reproducibility is enhanced by using photolithographic patterning and etching to produce both the patch antenna array and the feed network.

Strassner, II, Bernd H. (Albuquerque, NM)

2007-01-23

7

Triploid planarian reproduces truly bisexually with euploid gametes produced through a different meiotic system between sex.  

PubMed

Although polyploids are common among plants and some animals, polyploidization often causes reproductive failure. Triploids, in particular, are characterized by the problems of chromosomal pairing and segregation during meiosis, which may cause aneuploid gametes and results in sterility. Thus, they are generally considered to reproduce only asexually. In the case of the Platyhelminthes Dugesia ryukyuensis, populations with triploid karyotypes are normally found in nature as both fissiparous and oviparous triploids. Fissiparous triploids can also be experimentally sexualized if they are fed sexual planarians, developing both gonads and other reproductive organs. Fully sexualized worms begin reproducing by copulation rather than fission. In this study, we examined the genotypes of the offspring obtained by breeding sexualized triploids and found that the offspring inherited genes from both parents, i.e., they reproduced truly bisexually. Furthermore, meiotic chromosome behavior in triploid sexualized planarians differed significantly between male and female germ lines, in that female germ line cells remained triploid until prophase I, whereas male germ line cells appeared to become diploid before entry into meiosis. Oocytes at the late diplotene stage contained not only paired bivalents but also unpaired univalents that were suggested to produce diploid eggs if they remained in subsequent processes. Triploid planarians may therefore form euploid gametes by different meiotic systems in female and male germ lines and thus are be able to reproduce sexually in contrast to many other triploid organisms. PMID:24402417

Chinone, Ayako; Nodono, Hanae; Matsumoto, Midori

2014-06-01

8

V-305 high-bandwidth analog airborne recorder/reproducer  

NASA Astrophysics Data System (ADS)

The V-305 High-Bandwidth Analog Airborne Recorder/Reproducer has been specifically developed to satisfy the airborne image recording requirements for various applications including high-resolution airborne reconnaissance, search and rescue operations, and surveillance. In addition, the V-305 has the flexibility to record many other types of signals such as those encountered in E-W, ELINT, and radar applications. As part of this new product's ongoing development and evaluation, NACOUS has recently performed airborne recording of infrared imagery from an AN/AAD-5 RC Infrared Linescanner. This paper describes the V-305 and the in-flight image recording results.

Ludeke, Peter J.

1993-02-01

9

Process validation and screen reproducibility in high-throughput screening.  

PubMed

The use of large-scale compound screening has become a key component of drug discovery projects in both the pharmaceutical and the biotechnological industries. More recently, these activities have also been embraced by the academic community as a major tool for chemical genomic activities. High-throughput screening (HTS) activities constitute a major step in the initial drug discovery efforts and involve the use of large quantities of biological reagents, hundreds of thousands to millions of compounds, and the utilization of expensive equipment. All these factors make it very important to evaluate in advance of the HTS campaign any potential issues related to reproducibility of the experimentation and the quality of the results obtained at the end of these very costly activities. In this article, the authors describe how GlaxoSmithKline (GSK) has addressed the need of a true validation of the HTS process before embarking in full HTS campaigns. They present 2 different aspects of the so-called validation process: (1) optimization of the HTS workflow and its validation as a quality process and (2) the statistical evaluation of the HTS, focusing on the reproducibility of results and the ability to distinguish active from nonactive compounds in a vast collection of samples. The authors describe a variety of reproducibility indexes that are either innovative or have been adapted from generic medical diagnostic screening strategies. In addition, they exemplify how these validation tools have been implemented in a number of case studies at GSK. PMID:19171922

Coma, Isabel; Clark, Liz; Diez, Emilio; Harper, Gavin; Herranz, Jesus; Hofmann, Glenn; Lennon, Mark; Richmond, Nicola; Valmaseda, Manuel; Macarron, Ricardo

2009-01-01

10

A simple safe, reliable and reproducible mechanism for producing experimental bite marks.  

PubMed

With improving technology it should be possible to develop an objective, reliable and valid method that can be undertaken by most forensic Odontologists without recourse to expensive or bulky equipment. One of the main factors that affect the physical appearance of bitemark is the amount of force applied during biting. There is little evidence relating the appearance of a bite mark to the amount of force applied and how that force relates to the biters maximal biteforce. This paper describes simple apparatus that can be used to inflict experimental bites on living subjects reproducibly and with minimal risk. The aims of this study are to report on the development of a mechanical apparatus that produces experimental bitemarks on living human subjects with a known force in a safe, reliable and reproducible manner and to relate the force applied during production of the experimental bitemark to the maximum bite force of the biter. Maximum bite force of one of the authors was determined as 324N. Experimental bitemarks were inflicted on living subjects with known weights. Weights of up to 10kg were well tolerated by the subjects. The relation between forces used to inflict bites and the maximum bite force of the author is reported, with 10kg being approximately one third of the maximum bite force. The apparatus was well tolerated and the results were reliable and reproducible. The results from this study could help in determining the severity of bitemarks. This apparatus could help researchers in developing objective based bitemark analysis techniques. PMID:24776438

Chinni, S S; Al-Ibrahim, A; Forgie, A H

2013-01-01

11

Reproducible Crystallite Size of Mono-Dispersed and Scalable Biologically Produced Metal-Substituted Nanometer-Sized Magnetites  

NASA Astrophysics Data System (ADS)

Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibited similar properties as chemically synthesized magnetite. To complement uses of the traditional chemically synthesized magnetite (chem-magnetite) biomagnetite must be exhibit highly reproducible sizes and be available in scalable qualities. Here we emphasize potentially advantageous properties of biomagnetite regarding size, reproducibility and scaling availability. Average crystallite size (ACS) of biomagnetites ranging from 10-100 nm was determined after varied 1) incubation times, 2) substitution of metal and lanthanide species, 3) degrees of congruent incorporation or retardation of substitution elements, 4) bacterial species with their varied ability to substitute elemental species, and 6) incubation temperature that can influence coalescence. The microbial production of biomagnetite has demonstrated capacity to make highly crystalline nanoscale particles of metal-substituted ferrites including compounds of Co, Ni, Cr, Mn, Zn and the rare earths in large quantity. Selected Zn-substituted magnetite (nominal composition of Zn0.6Fe2.4O4) has been recovered at over 1 kg (wet weight) in batches from 30 L fermentations. The massively produced extracellular magnetites were confirmed to exhibit good mono- dispersity via transmission electron microscopy (TEM). TEM also validated highly reproducible ACS of 13.1±0.8 nm size as determined through X-ray diffraction (N=7) at a 99 % confidence level. Based on the scale-up experiments performed using the 35 L reactor, the reduction in ACS variability and shorted incubation times of several days may be attributed to increases of electron donor input, and availability of divalent ions of the substitution metal with less ferrous ions in the case of doped magnetite, or a combination of the above. While costs of commercial nanometer sized magnetite (25-50 nm) may vary from 500/kg to > 1,000/kg, microbial mass production is likely capable of producing 13-90 nm magnetite or doped magnetites at a fraction of the cost of traditional chemical synthesis. While there are numerous approaches for the synthesis of nanoparticles, bacterial fermentation of magnetite or metal-substituted magnetite may represent a disruptive manufacturing technology with respect to yield, reproducibility and scalability.

Moon, J.; Rawn, C.; Rondinone, A.; Love, L.; Roh, Y.; Lauf, R.; Phelps, T.

2008-12-01

12

Reproducible Crystallite Size of Mono-Dispersed and Scalable Biologically Produced Metal-Substituted Nanometer-Sized Magnetites  

Microsoft Academic Search

Our previous research demonstrated that biosynthesized magnetite (biomagnetite) exhibited similar properties as chemically synthesized magnetite. To complement uses of the traditional chemically synthesized magnetite (chem-magnetite) biomagnetite must be exhibit highly reproducible sizes and be available in scalable qualities. Here we emphasize potentially advantageous properties of biomagnetite regarding size, reproducibility and scaling availability. Average crystallite size (ACS) of biomagnetites ranging from

J. Moon; C. Rawn; A. Rondinone; L. Love; Y. Roh; R. Lauf; T. Phelps

2008-01-01

13

Process Validation and Screen Reproducibility in High-Throughput Screening  

Microsoft Academic Search

The use of large-scale compound screening has become a key component of drug discovery projects in both the pharmaceutical and the biotechnological industries. More recently, these activities have also been embraced by the academic community as a major tool for chemical genomic activities. High-throughput screening (HTS) activities constitute a major step in the initial drug discovery efforts and involve the

Isabel Coma; Liz Clark; Emilio Diez; Gavin Harper; Jesus Herranz; Glenn Hofmann; Mark Lennon; Nicola Richmond; Manuel Valmaseda; Ricardo Macarron

2009-01-01

14

Biomolecular sensing for cancer diagnostics using highly reproducible SERS substrates  

NASA Astrophysics Data System (ADS)

We developed a SERS biosensor based on gold fishnets fabricated by using e-beam lithography. This device is used for glycerophosphoinositol (GroPIns) molecule sensing. GroPIns is an abundant component of cell cytosol and high GroPIns levels have been reported in several tumour cells. We demonstrate that our SERS sensor is able to accurately and quantitatively determine the concentration of GroPIns. These results indicate that SERS may provide a novel platform technology to identify GroPIns profiles in disease pathogenesis.

De Luca, Anna Chiara; Reader-Harris, Peter; Mazilu, Michael; Managò, Stefano; Mariggiò, Stefania; Corda, Daniela; Di Falco, Andrea

2014-03-01

15

High-throughput miniaturized bioreactors for cell culture process development: Reproducibility, scalability, and control.  

PubMed

Decreasing the timeframe for cell culture process development has been a key goal toward accelerating biopharmaceutical development. Advanced Microscale Bioreactors (ambr™) is an automated micro-bioreactor system with miniature single-use bioreactors with a 10-15 mL working volume controlled by an automated workstation. This system was compared to conventional bioreactor systems in terms of its performance for the production of a monoclonal antibody in a recombinant Chinese Hamster Ovary cell line. The miniaturized bioreactor system was found to produce cell culture profiles that matched across scales to 3 L, 15 L, and 200 L stirred tank bioreactors. The processes used in this article involve complex feed formulations, perturbations, and strict process control within the design space, which are in-line with processes used for commercial scale manufacturing of biopharmaceuticals. Changes to important process parameters in ambr™ resulted in predictable cell growth, viability and titer changes, which were in good agreement to data from the conventional larger scale bioreactors. ambr™ was found to successfully reproduce variations in temperature, dissolved oxygen (DO), and pH conditions similar to the larger bioreactor systems. Additionally, the miniature bioreactors were found to react well to perturbations in pH and DO through adjustments to the Proportional and Integral control loop. The data presented here demonstrates the utility of the ambr™ system as a high throughput system for cell culture process development. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:718-727, 2014. PMID:24449637

Rameez, Shahid; Mostafa, Sigma S; Miller, Christopher; Shukla, Abhinav A

2014-05-01

16

Month-to-month and year-to-year reproducibility of high frequency QRS ECG signals  

NASA Technical Reports Server (NTRS)

High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of root mean squared voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are sufficiently reproducible for clinical use.

Batdorf, Niles J.; Feiveson, Alan H.; Schlegel, Todd T.

2004-01-01

17

Efficient and reproducible high resolution spiral myocardial phase velocity mapping of the entire cardiac cycle  

PubMed Central

Background Three-directional phase velocity mapping (PVM) is capable of measuring longitudinal, radial and circumferential regional myocardial velocities. Current techniques use Cartesian k-space coverage and navigator-gated high spatial and high temporal resolution acquisitions are long. In addition, prospective ECG-gating means that analysis of the full cardiac cycle is not possible. The aim of this study is to develop a high temporal and high spatial resolution PVM technique using efficient spiral k-space coverage and retrospective ECG-gating. Detailed analysis of regional motion over the entire cardiac cycle, including atrial systole for the first time using MR, is presented in 10 healthy volunteers together with a comprehensive assessment of reproducibility. Methods A navigator-gated high temporal (21 ms) and spatial (1.4?×?1.4 mm) resolution spiral PVM sequence was developed, acquiring three-directional velocities in 53 heartbeats (100% respiratory-gating efficiency). Basal, mid and apical short-axis slices were acquired in 10 healthy volunteers on two occasions. Regional and transmural early systolic, early diastolic and atrial systolic peak longitudinal, radial and circumferential velocities were measured, together with the times to those peaks (TTPs). Reproducibilities were determined as mean?±?SD of the signed differences between measurements made from acquisitions performed on the two days. Results All slices were acquired in all volunteers on both occasions with good image quality. The high temporal resolution allowed consistent detection of fine features of motion, while the high spatial resolution allowed the detection of statistically significant regional and transmural differences in motion. Colour plots showing the regional variations in velocity over the entire cardiac cycle enable rapid interpretation of the regional motion within any given slice. The reproducibility of peak velocities was high with the reproducibility of early systolic, early diastolic and atrial systolic peak radial velocities in the mid slice (for example) being ?0.01?±?0.36, 0.20?±?0.56 and 0.14?±?0.42 cm/s respectively. Reproducibility of the corresponding TTP values, when normalised to a fixed systolic and diastolic length, was also high (?13.8?±?27.4, 1.3?±?21.3 and 3.0?±?10.9 ms for early systolic, early diastolic and atrial systolic respectively). Conclusions Retrospectively gated spiral PVM is an efficient and reproducible method of acquiring 3-directional, high resolution velocity data throughout the entire cardiac cycle, including atrial systole.

2013-01-01

18

Month-to-Month and Year-to-Year Reproducibility of High Frequency QRS ECG signals  

NASA Technical Reports Server (NTRS)

High frequency (HF) electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. We therefore prospectively investigated the reproducibility of the root mean squared (RMS) voltage, kurtosis, and the presence versus absence of reduced amplitude zones (RAzs) in signal averaged 12-lead HF QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of RMS voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-lead and CR-lead derivations. The relative error of RMS voltage was 12% month-to-month and 16% year-to-year in the serial recordings when averaged over all 12 leads. RAzs were also reproducible at a rate of up to 87% and 8 1 %, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead HF QRS electrocardiograms are sufficiently reproducible for clinical use.

Batdorf, Niles; Feiveson, Alan H.; Schlegel, Todd T.

2006-01-01

19

Rapidly-dissolvable microneedle patches via a highly scalable and reproducible soft lithography approach.  

PubMed

Microneedle devices for transdermal drug delivery have recently become an attractive method to overcome the diffusion-limiting epidermis and effectively transport therapeutics to the body. Here, we demonstrate the fabrication of highly reproducible and completely dissolvable polymer microneedles on flexible water-soluble substrates. These biocompatible microneedles (made by using a soft lithography process known as PRINT) showed efficacy in piercing both murine and human skin samples and delivering a fluorescent drug surrogate to the tissue. PMID:23893866

Moga, Katherine A; Bickford, Lissett R; Geil, Robert D; Dunn, Stuart S; Pandya, Ashish A; Wang, Yapei; Fain, John H; Archuleta, Christine F; O'Neill, Adrian T; Desimone, Joseph M

2013-09-25

20

Highly reproducible hybridization assay of zeptomole DNA based on adsorption of nanoparticle-bioconjugate.  

PubMed

A nanoparticle-bioconjugate was formed by homogeneous hybridization of one polynucleotide target with two oligonucleotide probes labelled by thiol and a nanoparticle, respectively. Deposition of the nanoparticle-bioconjugate on a gold surface by thiol-gold reaction was monitored in situ by quartz crystal microbalance (QCM) and applied for flow analysis of zeptomole amounts of polynucleotide. The formation in solution and adsorption of thiolated conjugates on gold could be fast, uniform and effective, and has been successfully exploited to construct a highly reproducible and sensitive platform for detection of target sequences. Being more rapid, reproducible, sensitive and amenable to automation than previously reported microgravimetric hybridization assays, this technology has great promise for practical applications in molecular diagnostics. PMID:16284656

Mo, Zhihong; Wang, Hongli; Liang, Yulong; Liu, Fengwei; Xue, Yongxin

2005-12-01

21

Pronuclear injection-based mouse targeted transgenesis for reproducible and highly efficient transgene expression  

PubMed Central

Mouse transgenesis has proven invaluable for analysis of gene function and generation of human disease models. We describe here the development of a pronuclear injection-based targeted transgenesis (PITT) system, involving site-specific integration in fertilized eggs. The system was applied to two different genomic target loci to generate a series of transgenic lines including fluorescent mice, which reproducibly displayed strong, ubiquitous and stable transgene expression. We also demonstrated that knockdown mice could be readily generated by PITT by taking advantage of the reproducible and highly efficient expression system. The PITT system, which circumvents the problem of unpredictable and unstable transgene expression of conventional random-integration transgenic mice, reduces the time, cost and effort needed to generate transgenic mice, and is potentially applicable to both in vivo ‘gain-of-function’ and ‘loss-of-function’ studies.

Ohtsuka, Masato; Ogiwara, Sanae; Miura, Hiromi; Mizutani, Akiko; Warita, Takayuki; Sato, Masahiro; Imai, Kenji; Hozumi, Katsuto; Sato, Takehito; Tanaka, Masafumi; Kimura, Minoru; Inoko, Hidetoshi

2010-01-01

22

Observation of highly reproducible resistive-switching behavior from solution-based ZnO nanorods.  

PubMed

The authors report upon highly reproducible, unipolar resistive-switching random access memory with narrow voltage distributions using Au/ZnO nanorods/Au structures. The ZnO nanorods resistive switching layer was prepared by a simple spin-coating process on a sol-gel seed layer, and from its size confinement effect, this device showed narrow set/reset voltage distributions and low voltage operations compared with Au/ZnO thin film/Au structures. With this electrical uniformity, the device exhibited good reliabilities such as long retention (> 70000 sec) and high endurance (> 5000 cycles). PMID:24205631

Song, Min Yeong; Seo, Yujeong; Park, Soyun; Lee, Jae Hyuk; An, Ho-Myoung; Kim, Tae Geun

2013-09-01

23

Design of experiments for highly reproducible pulsed laser deposition of YBa2Cu3O7-?  

NASA Astrophysics Data System (ADS)

Pulsed laser deposition (PLD) is a very versatile tool to deposit thin films from a large variety of materials. Pulsed KrF excimer laser radiation at 248 nm wavelength can be employed to evaporate most oxide materials. Special focus has been put on transferring the stoichiometry of the target to the thin film, which is very important for complex oxides such as the cuprate high-temperature superconductors. For the multilayer deposition of superconducting devices highly reproducible thin films with controlled morphological and electronic properties are required. We report on methods of experimental design for the optimized deposition of YBa2Cu3O7-? thin films on single crystalline oxide substrates.

Schilling, M.; Guillaume, A.; Scholtyssek, J. M.; Ludwig, F.

2014-01-01

24

Reproducibility of ultrasonography for assessing abdominal fat distribution in a population at high risk of diabetes  

PubMed Central

Background: Visceral fat plays an important role in the development of metabolic disease independently of the effect of overall abdominal fat. Ultrasonography is an accessible method of accurately assessing abdominal fat distribution in epidemiological studies, but few details about the reproducibility of this method have been published. Objective: The aim of this study was to investigate the reproducibility of ultrasonography in the assessment of abdominal fat distribution in a population at high risk of type 2 diabetes. Design and Methods: Ultrasonography was used to estimate visceral and subcutaneous abdominal fat. Intra- and interobserver variation, short-term variation and variation between estimates in the fasting and non-fasting state were examined in three samples of 30, 33 and 23 participants from the ADDITION-PRO study. A variance components model was used to calculate intra- and interobserver variation, and Bland–Altman plots were drawn for all three substudies. Results: Coefficients of variation for intra- and interobserver variation were in the range 3.4–6.1%, except for interobserver variation for subcutaneous fat (9.5%). Short-term variation over a median of 35 days had a coefficient of variation of 15%. The effect of a meal was primarily on the visceral estimates and did not extend beyond the first postprandial hour. Non-fasting visceral estimates were larger than fasting estimates. Conclusion: Both visceral and subcutaneous fat can be estimated with ultrasonography with adequate intra- and interobserver reproducibility by clinical researchers with limited training, making it a feasible method of assessing abdominal fat distribution in epidemiological studies.

Philipsen, A; Carstensen, B; Sandbaek, A; Almdal, T P; Johansen, N B; J?rgensen, M E; Witte, D R

2013-01-01

25

Highly reproducible low temperature scanning tunneling microscopy and spectroscopy with in situ prepared tips.  

PubMed

An in situ tip preparation procedure compatible with ultra-low temperature and high magnetic field scanning tunneling microscopes is presented. This procedure does not require additional preparation techniques such as thermal annealing or ion milling. It relies on the local electric-field-induced deposition of material from the tip onto the studied surface. Subsequently, repeated indentations are performed onto the sputtered cluster to mechanically anneal the tip apex and thus to ensure the stability of the tip. The efficiency of this method is confirmed by comparing the topography and spectroscopy data acquired with either unprepared or in situ prepared tips on epitaxial graphene grown on Ru (0001). We demonstrate that the use of in situ prepared tips increases the stability of the scanning tunneling images and the reproducibility of the spectroscopic measurements. PMID:22955323

Castellanos-Gomez, Andres; Rubio-Bollinger, Gabino; Garnica, Manuela; Barja, Sara; Vázquez de Parga, Amadeo L; Miranda, Rodolfo; Agraït, Nicolás

2012-11-01

26

High speed and reproducible analysis of nitrosamines by capillary electrophoresis with a sulfonated capillary.  

PubMed

Recently environmental control is regarded as important for good human health conditions, and toxic substances, including carcinogens and endocrine disruptors should be eliminated from our living environment. Hence easy quantitative methods are expected for a high level of environmental control. Our previous paper describes an easy quantitative analysis of nitrosamines (NAs) by capillary electrophoresis with an untreated fused silica capillary installed in an ordinary apparatus. In this paper, utilizing a novel type capillary column having sulfonated inner wall was investigated for improvements of separation performance and reproducibility. A sulfonated capillary causes fast and stabile electroosmotic flow because its inner wall is strongly negative charged. On a performance comparison of a sulfonated capillary with an untreated fused silica, analysis time reduction of c.a. forty percent was achieved, and relative standard deviations of migration times and peak responses were less than one third. In addition sample concentrations giving detection and quantitation limits were also reduced to a half. PMID:17898509

Taga, Atsushi; Nishi, Tomoko; Honda, Yoshitaka; Sato, Atsushi; Terashima, Hiroyuki; Suzuki, Kentaro; Kodama, Shuji; Boki, Keito

2007-01-01

27

A Novel Highly Reproducible and Lethal Nonhuman Primate Model for Orthopox Virus Infection  

PubMed Central

The intentional re-introduction of Variola virus (VARV), the agent of smallpox, into the human population is of great concern due its bio-terroristic potential. Moreover, zoonotic infections with Cowpox (CPXV) and Monkeypox virus (MPXV) cause severe diseases in humans. Smallpox vaccines presently available can have severe adverse effects that are no longer acceptable. The efficacy and safety of new vaccines and antiviral drugs for use in humans can only be demonstrated in animal models. The existing nonhuman primate models, using VARV and MPXV, need very high viral doses that have to be applied intravenously or intratracheally to induce a lethal infection in macaques. To overcome these drawbacks, the infectivity and pathogenicity of a particular CPXV was evaluated in the common marmoset (Callithrix jacchus). A CPXV named calpox virus was isolated from a lethal orthopox virus (OPV) outbreak in New World monkeys. We demonstrated that marmosets infected with calpox virus, not only via the intravenous but also the intranasal route, reproducibly develop symptoms resembling smallpox in humans. Infected animals died within 1–3 days after onset of symptoms, even when very low infectious viral doses of 5×102 pfu were applied intranasally. Infectious virus was demonstrated in blood, saliva and all organs analyzed. We present the first characterization of a new OPV infection model inducing a disease in common marmosets comparable to smallpox in humans. Intranasal virus inoculation mimicking the natural route of smallpox infection led to reproducible infection. In vivo titration resulted in an MID50 (minimal monkey infectious dose 50%) of 8.3×102 pfu of calpox virus which is approximately 10,000-fold lower than MPXV and VARV doses applied in the macaque models. Therefore, the calpox virus/marmoset model is a suitable nonhuman primate model for the validation of vaccines and antiviral drugs. Furthermore, this model can help study mechanisms of OPV pathogenesis.

Kramski, Marit; Matz-Rensing, Kerstin; Stahl-Hennig, Christiane; Kaup, Franz-Josef; Nitsche, Andreas; Pauli, Georg; Ellerbrok, Heinz

2010-01-01

28

Reproducible Science?  

PubMed Central

The reproducibility of an experimental result is a fundamental assumption in science. Yet, results that are merely confirmatory of previous findings are given low priority and can be difficult to publish. Furthermore, the complex and chaotic nature of biological systems imposes limitations on the replicability of scientific experiments. This essay explores the importance and limits of reproducibility in scientific manuscripts.

Casadevall, Arturo; Fang, Ferric C.

2010-01-01

29

State-of-the-art exposure chamber for highly controlled and reproducible THz biological effects studies  

NASA Astrophysics Data System (ADS)

Terahertz (THz) imaging and sensing technologies are increasingly being used at international airports for security screening purposes and at major medical centers for cancer and burn diagnosis. The emergence of new THz applications has directly resulted in an increased interest regarding the biological effects associated with this frequency range. Knowledge of THz biological effects is also desired for the safe use of THz systems, identification of health hazards, and development of empirically-based safety standards. In this study, we developed a state-of-the-art exposure chamber that allowed for highly controlled and reproducible studies of THz biological effects. This innovative system incorporated an industry grade cell incubator system that permitted a highly controlled exposure environment, where temperatures could be maintained at 37 °C +/- 0.1 °C, carbon dioxide (CO2) levels at 5% +/- 0.1%, and relative humidity (RH) levels at 95% +/- 1%. To maximize the THz power transmitted to the cell culture region inside the humid incubator, a secondary custom micro-chamber was fabricated and incorporated into the system. This micro-chamber shields the THz beam from the incubator environment and could be nitrogen-purged to eliminate water absorption effects. Additionally, a microscope that allowed for real-time visualization of the live cells before, during, and after THz exposure was integrated into the exposure system.

Cerna, Cesario Z.; Elam, David P.; Echchgadda, Ibtissam; Sloan, Mark A.; Wilmink, Gerald J.

2014-03-01

30

Reproducible fabrication of stable small nano Pt with high activity for sensor applications  

NASA Astrophysics Data System (ADS)

Pt nanoparticles with an average size of 2-3 nm in diameter were reproducibly synthesized by reduction of H2PtCl6 solution containing inositol hexaphosphate (IP6) as the stabilizing agent. Single crystals with Pt(111) faces of the resulting cubic nanoparticles were revealed by the electron diffraction pattern. The PtNPs-IP6 nanoparticles were used to modify an electrode as a nonenzymatic sensor for H2O2 detection, exhibiting a fast response and high sensitivity. A low detection limit of 2.0 × 10-7 M (S/N = 3) with two linear ranges between 2.4 × 10-7 and 1.3 × 10-3 M (R2 = 0.9987) and between 1.3 × 10-3 and 1.3 × 10-2 M (R2 = 0.9980) was achieved. The attractive electrochemical performance of PtNPs-IP6 enables it to be employed as a promising material for the development of Pt-based analytical systems and other applications.

Ye, Pingping; Guo, Xiaoyu; Liu, Guiting; Chen, Huifen; Pan, Yuxia; Wen, Ying; Yang, Haifeng

2013-07-01

31

High Performance High Repetition Rate Miniature Plasma Focus Device: Record Time Averaged Neutron Yield at 200 J with Enhanced Reproducibility  

NASA Astrophysics Data System (ADS)

A high performance high repetition rate plasma focus device with significant time averaged neutron yield and greater shot to shot reproducibility could be a highly valuable neutron source for Homeland Security applications. The single module fast miniature plasma focus `FMPF-2' (2.4 ?F, 56 ± 3 nH, 89 kA @ 14.0 kV, T/4~575 ns) was upgraded to four module `FMPF-3' (2.4 ?F, 34 ± 2 nH, 103 kA @ 14.0 kV, T/4~458 ns) device. The time averaged neutron output of (1.4 ± 0.6) × 106 n/sec at 1 Hz operation was enhanced to the record value of (1.4 ± 0.2) × 107 n/sec at 10 Hz operation for the burst length of 50 consecutive shots for deuterium filling gas pressure of 5.5 mbar in FMPF-3 device at storage energy of ~200 J. Other key findings of the investigation were: (i) the deuterium filling gas pressure for single shot and repetitive modes of device operation were needed to be optimized separately, and (ii) in the repetitive mode of operation the deuterium filling gas pressure was higher than that obtained for single shot mode and also yielded better reproducibility in neutron emission.

Verma, Rishi; Rawat, R. S.; Lee, P.; Springham, S. V.; Tan, T. L.

2013-02-01

32

Reproducible method to enrich membrane proteins with high purity and high yield for an LC-MS/MS approach in quantitative membrane proteomics.  

PubMed

The proportionately low abundance of membrane proteins hampers their proteomic analysis, especially for a quantitative LC-MS/MS approach. To overcome this limitation, a method was developed that consists of one cell disruption step in a hypotonic reagent using liquid nitrogen, one isolation step using a low speed centrifugation, and three wash steps using high speed centrifugation. Pellets contained plasma, nuclear, and mitochondrial membranes, including their integral, peripheral, and anchored membrane proteins. The reproducibility of this method was verified by protein assay of four separate experiments with a CV of 7.7%, and by comparative LC-MS/MS label-free quantification of individual proteins between two experiments with 99% of the quantified proteins having a CV ?30%. Western blot and LC-MS/MS results of markers for cytoplasm, nucleus, mitochondria, and their membranes indicated that the enriched membrane fraction was highly pure by the absence of, or presence of trace amounts of, nonmembrane marker proteins. The average yield of membrane proteins was 237 ?g/10 million HT29-MTX cells. LC-MS/MS analysis of the membrane-enriched sample resulted in the identification of 2597 protein groups. In summary, the developed method is reproducible, produces a highly pure membrane fraction, and generates a high yield of membrane proteins. PMID:23334993

Lai, Xianyin

2013-03-01

33

Quantifying Trends in Disease Impact to Produce a Consistent and Reproducible Definition of an Emerging Infectious Disease  

PubMed Central

The proper allocation of public health resources for research and control requires quantification of both a disease's current burden and the trend in its impact. Infectious diseases that have been labeled as “emerging infectious diseases” (EIDs) have received heightened scientific and public attention and resources. However, the label ‘emerging’ is rarely backed by quantitative analysis and is often used subjectively. This can lead to over-allocation of resources to diseases that are incorrectly labelled “emerging,” and insufficient allocation of resources to diseases for which evidence of an increasing or high sustained impact is strong. We suggest a simple quantitative approach, segmented regression, to characterize the trends and emergence of diseases. Segmented regression identifies one or more trends in a time series and determines the most statistically parsimonious split(s) (or joinpoints) in the time series. These joinpoints in the time series indicate time points when a change in trend occurred and may identify periods in which drivers of disease impact change. We illustrate the method by analyzing temporal patterns in incidence data for twelve diseases. This approach provides a way to classify a disease as currently emerging, re-emerging, receding, or stable based on temporal trends, as well as to pinpoint the time when the change in these trends happened. We argue that quantitative approaches to defining emergence based on the trend in impact of a disease can, with appropriate context, be used to prioritize resources for research and control. Implementing this more rigorous definition of an EID will require buy-in and enforcement from scientists, policy makers, peer reviewers and journal editors, but has the potential to improve resource allocation for global health.

Funk, Sebastian; Bogich, Tiffany L.; Jones, Kate E.; Kilpatrick, A. Marm; Daszak, Peter

2013-01-01

34

Unrefined wood hydrolysates are viable reactants for the reproducible synthesis of highly swellable hydrogels.  

PubMed

A value-adding robust and sequential synthetic pathway was elaborated to produce hydrogel structures with ionic character from crude acetylated galactoglucomannan-rich wood hydrolysate (WH). The WH was first-step liquor originating from a sulphite cracking pulp process for dissolving pulp. The synthetically modified WH fractions were verified at each step by NMR and FTIR, and the hydrogels were characterized with respect to their swelling and mechanical properties. Altering the crosslinking chemistry and the content of ionic moieties resulted in hydrogels with various swelling ratios and mechanical properties. Renewable hydrogel formulations with swelling ratios as high as Qeq=270 were achieved. PMID:24751275

Maleki, Laleh; Edlund, Ulrica; Albertsson, Ann-Christine

2014-08-01

35

Highly uniform and reproducible vertical-cavity surface emitting lasers grown by metalorganic chemical vapor deposition  

SciTech Connect

We show that the uniformity of the lasing wavelength of vertical-cavity surface emitting lasers (VCSELs) can be as good as {plus_minus}0.3% across a entire 3 in. wafer in MOCVD growth with a similar run-to-run reproducibility.

Hou, H.Q.; Chui, H.C.; Choquette, K.D.; Hammons, B.E.; Breiland, W.G.; Geib, K.M.

1996-01-01

36

The Hydrodynamics of High Temperature Plasma: Reproducing the Properties of High Temperature Emission in Solar Active Regions  

NASA Astrophysics Data System (ADS)

The launch of Hinode and SDO have revolutionized our ability to measure the plasma properties of the solar corona. Many studies have documented both the temperature structure of the corona as well as its temporal variability. Of particular interest is the behavior of high temperature loops that are typically found in the core of an active region. Temperature distributions in these regions are often sharply peaked near 4 MK but rapidly evolving loops are also observed. In this talk we will present results from our effort to perform hydrodynamic simulations of 15 solar active regions that cover a wide range of solar conditions and to reconcile these simulations with observations. In this work we have coupled non-linear force free extrapolations with solutions to the hydrodynamic loop equations approximated by EBTEL. Using relatively simple heating scenarios we are able to reproduce three important properties of the observations: the dependance of the observed intensity on magnetic flux, the sharply peaked emission measure distributions for large regions, and the general frequency distribution of the observed events. Our current simulations, however, suggest much stronger 1MK emission near the neutral line than is observed, indicating the heating of small loops is not well understood. We also do not properly reproduce the relative distribution of large and small events in these active regions.

Ugarte-Urra, Ignacio; Warren, Harry

2014-06-01

37

Sandwich ELISA Microarrays: Generating Reliable and Reproducible Assays for High-Throughput Screens  

SciTech Connect

The sandwich ELISA microarray is a powerful screening tool in biomarker discovery and validation due to its ability to simultaneously probe for multiple proteins in a miniaturized assay. The technical challenges of generating and processing the arrays are numerous. However, careful attention to possible pitfalls in the development of your antibody microarray assay can overcome these challenges. In this chapter, we describe in detail the steps that are involved in generating a reliable and reproducible sandwich ELISA microarray assay.

Gonzalez, Rachel M.; Varnum, Susan M.; Zangar, Richard C.

2009-05-11

38

Highly sensitive, uniform, and reproducible surface-enhanced Raman spectroscopy from hollow au-ag alloy nanourchins.  

PubMed

A hierarchical nanoparticle strategy to simultaneously gain super Raman signal amplification, high uniformity, and reproducibility is presented. Using hollow Au-Ag alloy nanourchins, an ultrahigh sensitivity, e.g., down to 1 fM concentrations for DEHP molecule is obtained. A small standard deviation of <10% is achieved by simply dropping and evaporating sub-100 nm nanourchins onto a substrate. PMID:24449036

Liu, Zhen; Yang, Zhongbo; Peng, Bo; Cao, Cuong; Zhang, Chao; You, Hongjun; Xiong, Qihua; Li, Zhiyuan; Fang, Jixiang

2014-04-01

39

Elusive reproducibility.  

PubMed

Reproducibility remains a mirage for many biomedical studies because inherent experimental uncertainties generate idiosyncratic outcomes. The authentication and error rates of primary empirical data are often elusive, while multifactorial confounders beset experimental setups. Substantive methodological remedies are difficult to conceive, signifying that many biomedical studies yield more or less plausible results, depending on the attending uncertainties. Real life applications of those results remain problematic, with important exceptions for counterfactual field validations of strong experimental signals, notably for some vaccines and drugs, and for certain safety and occupational measures. It is argued that industrial, commercial and public policies and regulations could not ethically rely on unreliable biomedical results; rather, they should be rationally grounded on transparent cost-benefit tradeoffs. PMID:24882687

Gori, Gio Batta

2014-08-01

40

Do Important Papers Produce High Citation Counts?  

Microsoft Academic Search

In honor of the centennial of the American Astronomical Society, we asked 53 senior astronomers to select what they thought were the most important papers published in the Astronomical Journal or Astrophysical Journal during this century. This selection of important papers gives us the opportunity to determine whether important papers invariably produce high citation counts. We compared those papers with

Helmut A. Abt

2000-01-01

41

Highly reproducible memory effect of organic multilevel resistive-switch device utilizing graphene oxide sheets\\/polyimide hybrid nanocomposite  

Microsoft Academic Search

The functionalization of graphene oxide (GO) sheets with polyimide (PI) enables the layer-by-layer fabrication of a GO-PI hybrid resistive-switch device and leads to high reproducibility of the memory effect. The current-voltage curves for the as-fabricated device exhibit multilevel resistive-switch properties under various reset voltages. The capacitance-voltage characteristics for a capacitor based on GO-PI nanocomposite indicate that the electrical switching may

Chaoxing Wu; Fushan Li; Yongai Zhang; Tailiang Guo; Ting Chen

2011-01-01

42

Reproducible High Density Field-Reversed Configuration Plasma for Magnetized Target Fusion  

NASA Astrophysics Data System (ADS)

Field-Reversed Configuration (FRC) plasma will be translated into an imploding metal liner in a Magnetized Target Fusion (MTF) scenario. Field-Reversed Theta Pinch technology is employed with programmed cusp fields at the theta coil ends to achieve non-tearing field line reconnection during FRC formation. In the Field Reversed Configuration Experiment with a Liner (FRX-L), an optimum formation procedure is identified. The well-formed FRC plasma has volume-averaged density of 2 - 4x10^22m-3, Te+Ti of 300-500 eV, and plasma lifetime between 15-20 ?s. These parameters are very close to the desired parameters of a target plasma for MTF, and they can be reproduced with standard deviation of less than 10% about the mean in consecutive discharges. Recently, the redesigned crowbar switches have reduced the external main field modulation from 52% previously to 21% now. Better FRC performance is expected in on-going experimental campaigns.

Zhang, Shouyin; Grabowski, Chris; Ruden, Edward

2005-10-01

43

Method for producing highly reflective metal surfaces  

DOEpatents

The invention is a novel method for producing mirror surfaces which are extremely smooth and which have high optical reflectivity. The method includes depositing, by electrolysis, an amorphous layer of nickel on an article and then diamond-machining the resulting nickel surface to increase its smoothness and reflectivity. The machined nickel surface then is passivated with respect to the formation of bonds with electrodeposited nickel. Nickel then is electrodeposited on the passivated surface to form a layer of electroplated nickel whose inside surface is a replica of the passivated surface. The mandrel then may be-re-passivated and provided with a layer of electrodeposited nickel, which is then recovered from the mandrel providing a second replica. The mandrel can be so re-used to provide many such replicas. As compared with producing each mirror-finished article by plating and diamond-machining, the new method is faster and less expensive.

Arnold, J.B.; Steger, P.J.; Wright, R.R.

1982-03-04

44

Reproducible Growth of High-Quality Cubic-SiC Layers  

NASA Technical Reports Server (NTRS)

Semiconductor electronic devices and circuits based on silicon carbide (SiC) are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which devices made from conventional semiconductors cannot adequately perform. The ability of SiC-based devices to function under such extreme conditions is expected to enable significant improvements in a variety of applications and systems. These include greatly improved high-voltage switching for saving energy in public electric power distribution and electric motor drives; more powerful microwave electronic circuits for radar and communications; and sensors and controls for cleaner-burning, more fuel-efficient jet aircraft and automobile engines.

Neudeck, Philip G.; Powell, J. Anthony

2004-01-01

45

Month-to-Month and Year-to-Year Reproducibility of High Frequency QRS ECG signals.  

National Technical Information Service (NTIS)

High frequency (HF) electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized....

N. Batdorf A. H. Feiveson T. T. Schlegel

2006-01-01

46

A Compendium to Ensure Computational Reproducibility in High-Dimensional Classification Tasks  

Microsoft Academic Search

We demonstrate a concept and implementation of a compendium for the classification of high-dimensional data from microarray gene expression profiles. A compendium is an interactive document that bundles primary data, statistical processing methods, figures, and derived data together with the textual documentation and conclusions. Interactivity allows the reader to modify and extend these components. We address the following questions: how

Markus Ruschhaupt; Wolfgang Huber; Annemarie Poustka; Ulrich Mansmann

2004-01-01

47

A Fabrication Process for Microstrip-Coupled Superconducting Transition Edge Sensors Giving Highly Reproducible Device Characteristics  

Microsoft Academic Search

Astronomical instruments for measuring Cosmic Microwave Background polarisation, such as CLOVER, require large arrays of Superconducting\\u000a Transition Edge Sensors (TESs). We report recent results from a processing route development aimed at high yield fabrication\\u000a of microstrip-coupled TESs. The incoming signal is delivered onto a silicon nitride membrane by means of a superconducting\\u000a microstrip transmission line. This transmission line is then

D. M. Glowacka; D. J. Goldie; S. Withington; M. Crane; V. Tsaneva; M. D. Audley; A. Bunting

2008-01-01

48

High reproducible ADCC analysis revealed a competitive relation between ADCC and CDC and differences between Fc?Rllla polymorphism.  

PubMed

The anti-CD20 chimeric monoclonal antibody rituximab mediates cytotoxicity in malignant B cells via multiple mechanisms, including complement-dependent cytotoxicity (CDC), antibody-dependent cellular cytotoxicity (ADCC) and direct induction of apoptosis. To optimize treatment of non-Hodgkin's lymphoma, a fuller understanding of these mechanisms and their relative contributions to clinical efficacy is required. Here, we report the characteristics of the mutual impact between ADCC and CDC, the two major effector functions through the Fc receptors. To compare ADCC induced under various conditions, we developed a highly reproducible method of estimating ADCC activity using immortalized effector cells. The set of the effector cells that we established was able to calculate net ADCC with high reproducibility by comparing the cytotoxicity of effector cells expressing exogeneous Fc?RIIIa to those of mock effector cells. In addition, the different property of effector cells of two Fc?RIIIa single-nucleotide polymorphisms (SNP) could be also evaluated in exactly identical background. ADCC assessment in the presence of human serum directly provided the evidence of the competitive interaction of ADCC and CDC. The inhibition of ADCC of effector cells having low affinity SNP of Fc?RIIIa by active complement was more potent than those having high-affinity SNP at the rituximab-concentration comparable to the serum level obtained in patients. These findings could have a profound impact on optimization of the regimen of therapeutic antibodies and on the development of antibodies that will enhance effector function. PMID:22438420

Mishima, Yuji; Terui, Yasuhito; Mishima, Yuko; Kuniyoshi, Ryoko; Matsusaka, Satoshi; Mikuniya, Mariko; Kojima, Kiyotsugu; Hatake, Kiyohiko

2012-08-01

49

Controlled reproducible alignment of cone targets and mitigation of preplasma in high intensity laser interactions.  

PubMed

The use of cone targets in high intensity laser-plasma experiments has been of recent interest because of their potential use in integrated fast ignition experiments. Simpler experiments provide a good avenue for understanding the underlying physics, however precise control of the alignment along with good pointing accuracy is of crucial importance. While on big laser facilities target alignment is done precisely with several microscopes, it is not always the case on smaller facilities. This can have a detrimental effect on the quality of the results. We have developed and characterized a method for accurate alignment of intense laser pulses into a cone target. This, along with optimal positioning of the focus compared to the tip, efficiently uses the shape of the target to microfocus the laser light and concentrates the hot electrons in the tip, and can mitigate preplasma issues. PMID:19044348

Renard-Le Galloudec, Nathalie; Cho, Byoung-Ick; Osterholz, Jens; Ditmire, Todd

2008-08-01

50

A highly reproducible and economically competitive SNP analysis of several well characterized human mutations.  

PubMed

During the last years several genetic markers have appeared which were extensively studied for their clinical consequences and impact. Therefore, we developed 14 new genetic tests using the TaqMan technology. The new test systems detect the alpha1-antitrypsin, ACE, apolipoprotein B-100, apolipoprotein E, factor V Leiden, prothrombin, HFE, MTHFR, COL1A1, VDR and HLA-B27 mutations. These new kits were compared to the established endonuclease restriction digestion and flow cytometry, respectively. The results showed, that the allelic discrimination assays (TaqMan method) were in 100% concordance with the formerly used digestion method. Flow cytometry revealed a lower specificity in contrast to the TaqMan PCR system. Thus, it could be demonstrated that the new TaqMan assays are robust, rapid and automated methods for high throughput applications which avoid time consuming (and therefore expensive) and difficult post-PCR steps. PMID:15209439

Behrens, Martin; Lange, Robert

2004-01-01

51

Highly reproducible memory effect of organic multilevel resistive-switch device utilizing graphene oxide sheets/polyimide hybrid nanocomposite  

NASA Astrophysics Data System (ADS)

The functionalization of graphene oxide (GO) sheets with polyimide (PI) enables the layer-by-layer fabrication of a GO-PI hybrid resistive-switch device and leads to high reproducibility of the memory effect. The current-voltage curves for the as-fabricated device exhibit multilevel resistive-switch properties under various reset voltages. The capacitance-voltage characteristics for a capacitor based on GO-PI nanocomposite indicate that the electrical switching may originate from the charge trapping in GO sheets. The high device-to-device uniformity and unique memory properties of the device make it an attractive candidate for applications in next-generation high-density nonvolatile flash memories.

Wu, Chaoxing; Li, Fushan; Zhang, Yongai; Guo, Tailiang; Chen, Ting

2011-07-01

52

Efficient digest of high-throughput sequencing data in a reproducible report  

PubMed Central

Background High-throughput sequencing (HTS) technologies are spearheading the accelerated development of biomedical research. Processing and summarizing the large amount of data generated by HTS presents a non-trivial challenge to bioinformatics. A commonly adopted standard is to store sequencing reads aligned to a reference genome in SAM (Sequence Alignment/Map) or BAM (Binary Alignment/Map) files. Quality control of SAM/BAM files is a critical checkpoint before downstream analysis. The goal of the current project is to facilitate and standardize this process. Results We developed bamchop, a robust program to efficiently summarize key statistical metrics of HTS data stored in BAM files, and to visually present the results in a formatted report. The report documents information about various aspects of HTS data, such as sequencing quality, mapping to a reference genome, sequencing coverage, and base frequency. Bamchop uses the R language and Bioconductor packages to calculate statistical matrices and the Sweave utility and associated LaTeX markup for documentation. Bamchop's efficiency and robustness were tested on BAM files generated by local sequencing facilities and the 1000 Genomes Project. Source code, instruction and example reports of bamchop are freely available from https://github.com/CBMi-BiG/bamchop. Conclusions Bamchop enables biomedical researchers to quickly and rigorously evaluate HTS data by providing a convenient synopsis and user-friendly reports.

2013-01-01

53

High-yield synthesis of millimetre-long, semiconducting carbon nitride nanotubes with intense photoluminescence emission and reproducible photoconductivity  

NASA Astrophysics Data System (ADS)

High-yield synthesis of millimetre-long, semiconducting nanotubular g-C3N4 with aspect ratio higher than 10 000 and strong photoluminscence emission was reported. The formation process of the nanotube was based on one-dimensional fibrous self-assembly of the protonated melamine in glycol mediated with nitric acid aqueous solution, which was subsequently thermalyzed into tubular carbon nitride through a rolling-up mechanism. The synthesized carbon nitride nanotube exhibits intense luminescent emission, fast photoresponse, and reproducible photoconductivity.High-yield synthesis of millimetre-long, semiconducting nanotubular g-C3N4 with aspect ratio higher than 10 000 and strong photoluminscence emission was reported. The formation process of the nanotube was based on one-dimensional fibrous self-assembly of the protonated melamine in glycol mediated with nitric acid aqueous solution, which was subsequently thermalyzed into tubular carbon nitride through a rolling-up mechanism. The synthesized carbon nitride nanotube exhibits intense luminescent emission, fast photoresponse, and reproducible photoconductivity. Electronic supplementary information (ESI) available: Details of experimental procedures, characterizations, and supporting images. See DOI: 10.1039/c2nr30777d

Gao, Jun; Zhou, Yong; Li, Zhaosheng; Yan, Shicheng; Wang, Nanyan; Zou, Zhigang

2012-05-01

54

Highly reproducible swept-source, dispersion-encoded full-range biometry and imaging of the mouse eye  

NASA Astrophysics Data System (ADS)

We report a high-speed, dispersion-encoded, full-range (DEFR) swept-source optical coherence tomography system for in vivo ocular imaging and biometry of small animals. The fast DEFR algorithm removes the depth ambiguity, gives access to objects located at the zero delay position, and doubles the sampling depth to 2×5.0 mm (at -101 to -71 dB sensitivity) in a single scan using 2048 samples/depth scan 0.43 nm line width of a light source operating at 1056 nm with 70 nm tuning range. The acquisition speed (frames of 512 depth scans in 18.3 ms) permits precise on-line monitoring during positioning and provides cross-sectional views of the mouse eye. Preliminary studies demonstrate high-throughput, reproducible assessment of multiple biometric features (e.g., day-to-day reproducibility of axial length measurement +/-5.3 ?m) that is insensitive to eye motion sufficient for long-term monitoring.

Wang, Ling; Hofer, Bernd; Chen, Yen-Po; Guggenheim, Jeremy A.; Drexler, Wolfgang; Považay, Boris

2010-07-01

55

Maximizing the quantitative accuracy and reproducibility of Förster resonance energy transfer measurement for screening by high throughput widefield microscopy.  

PubMed

Förster resonance energy transfer (FRET) between fluorescent proteins (FPs) provides insights into the proximities and orientations of FPs as surrogates of the biochemical interactions and structures of the factors to which the FPs are genetically fused. As powerful as FRET methods are, technical issues have impeded their broad adoption in the biologic sciences. One hurdle to accurate and reproducible FRET microscopy measurement stems from variable fluorescence backgrounds both within a field and between different fields. Those variations introduce errors into the precise quantification of fluorescence levels on which the quantitative accuracy of FRET measurement is highly dependent. This measurement error is particularly problematic for screening campaigns since minimal well-to-well variation is necessary to faithfully identify wells with altered values. High content screening depends also upon maximizing the numbers of cells imaged, which is best achieved by low magnification high throughput microscopy. But, low magnification introduces flat-field correction issues that degrade the accuracy of background correction to cause poor reproducibility in FRET measurement. For live cell imaging, fluorescence of cell culture media in the fluorescence collection channels for the FPs commonly used for FRET analysis is a high source of background error. These signal-to-noise problems are compounded by the desire to express proteins at biologically meaningful levels that may only be marginally above the strong fluorescence background. Here, techniques are presented that correct for background fluctuations. Accurate calculation of FRET is realized even from images in which a non-flat background is 10-fold higher than the signal. PMID:23927839

Schaufele, Fred

2014-03-15

56

High-reproducibility, flexible conductive patterns fabricated with silver nanowire by drop or fit-to-flow method  

PubMed Central

An unusual strategy was designed to fabricate conductive patterns with high reproducibility for flexible electronics by drop or fit-to-flow method. Silver nanowire (SNW) ink with surface tension of 36.9 mN/m and viscosity of 13.8 mPa s at 20°C was prepared and characterized using a field emission transmission electron microscope, X-ray diffractometer, thermogravimetric analyzer, scanning electron microscope, and four-point probe. Polydimethylsiloxane (PDMS) pattern as template was fabricated by spin coating (500 rpm), baking at 80°C for 3 h, and laser cutting. The prepared SNW ink can flow along the trench of the PDMS pattern spontaneously, especially after plasma treatment with oxygen, and show a low resistivity of 12.9 ?? cm after sintering at 125°C for 30 min. In addition, an antenna pattern was also prepared to prove the feasibility of the approach.

2013-01-01

57

Sensitivity gains, linearity, and spectral reproducibility in nonuniformly sampled multidimensional MAS NMR spectra of high dynamic range.  

PubMed

Recently, we have demonstrated that considerable inherent sensitivity gains are attained in MAS NMR spectra acquired by nonuniform sampling (NUS) and introduced maximum entropy interpolation (MINT) processing that assures the linearity of transformation between the time and frequency domains. In this report, we examine the utility of the NUS/MINT approach in multidimensional datasets possessing high dynamic range, such as homonuclear (13)C-(13)C correlation spectra. We demonstrate on model compounds and on 1-73-(U-(13)C,(15)N)/74-108-(U-(15)N) E. coli thioredoxin reassembly, that with appropriately constructed 50 % NUS schedules inherent sensitivity gains of 1.7-2.1-fold are readily reached in such datasets. We show that both linearity and line width are retained under these experimental conditions throughout the entire dynamic range of the signals. Furthermore, we demonstrate that the reproducibility of the peak intensities is excellent in the NUS/MINT approach when experiments are repeated multiple times and identical experimental and processing conditions are employed. Finally, we discuss the principles for design and implementation of random exponentially biased NUS sampling schedules for homonuclear (13)C-(13)C MAS correlation experiments that yield high-quality artifact-free datasets. PMID:24752819

Suiter, Christopher L; Paramasivam, Sivakumar; Hou, Guangjin; Sun, Shangjin; Rice, David; Hoch, Jeffrey C; Rovnyak, David; Polenova, Tatyana

2014-06-01

58

Reproducible Preparation of Au/TS-1 with High Reaction Rate for Gas Phase Epoxidation of Propylene  

SciTech Connect

A refined and reliable synthesis procedure for Au/TS-1(Si/Ti molar ratio {approx}100) with high reaction rate for the direct gas phase epoxidation of propylene has been developed by studying the effects of pH of the gold slurry solution, mixing time, and preparation temperature for deposition precipitation (DP) of Au on TS-1 supports. Au/TS-1 catalysts prepared at optimal DP conditions (pH {approx} 7.3, mixing for 9.5 h, room temperature) showed an average PO rate {approx} 160 g{sub PO} h{sup -1} kg{sub Cat}{sup -1} at 200 C at 1 atm. A reproducibility better than {+-}10% was demonstrated by nine independent samples prepared at the same conditions. These are the highest rates yet reported at 200 C. No visible gold particles were observed by the HRTEM analysis in the fresh Au/TS-1 with gold loading up to {approx}0.1 wt%, indicating that the gold species were smaller than 1 nm. Additionally, the rate per gram of Au and the catalyst stability increased as the Au loading decreased, giving a maximum value of 500 g{sub PO} h{sup -1} g{sub Au}{sup -1}, and Si/Ti molar ratios of {approx}100 gave the highest rates.

Lee W. S.; Stach E.; Akatay, M.C.; Ribeiro, F.H.; Delgass, N.

2012-03-01

59

Development of semi-automated system for preparation of (188)Re aqueous solutions of high and reproducible activity concentrations.  

PubMed

A semi-automated system has been developed for elution and concentration of the (188)Re-eluate from 111 GBq (3 Ci) (188)W/(188)Re-generators to provide a dissolved beta-source of high (188)Re-activity per unit volume. The elution progress and concentration were precisely and continuously monitored by use of collimated diode detectors. By using ion exchange cartridges, small eluate volumes (2-3 ml) of maximum 40 GBq, (188)Re/ml activity concentration were routinely prepared. The concentrated (188)Re solutions were used to beta-irradiate aqueous suspensions and solutions of iodine species to evaluate a simulation of the extent of radiolytic decomposition of chemical species (AgI and CH(3)I) expected to accumulate in the containment sump of a nuclear reactor in the event of a severe accident with reproducible dose rates of up to 0.4 Gys(-1). Results have shown that AgI colloidal particles decompose to varying extents, depending on conditions, and in proportion to their initial mass, which indicates surface oxidation. Experiments have also confirmed CH(3)I decomposition in proportion to initial aqueous concentration. PMID:15963728

Jäckel, B; Cripps, R; Güntay, S; Bruchertseifer, H

2005-09-01

60

Quantitative Analysis with the Cameca Sxfive fe at High Lateral Resolution and High Reproducibility. Applications to Geochronology and Mineralogy.  

NASA Astrophysics Data System (ADS)

The development of the Schottky emitter and its implementation as electron source in Electron Microprobe has significantly improved the characterization of materials in earth sciences and in metallurgy. The strength of an Electron Probe Microanalysis (EPMA) is the ability to accurately measure and quantify element in traces at few 10's ppm level. The Field Emission (FE) Source allows trace element analysis with high beam currents thanks to the high brightness of the source and the excellent stability of the beam current, trading off spatial resolution. Of course, accuracy of major element quantification is maintained with a FE source. As X-rays are generated from a much larger diameter than the diameter of the incident electron beam, it is advised to work at low voltage and low beam current in order to take full advantage of the small spot sizes achievable with a Field Emission Source. Thus, the analytical resolution is not limited anymore by the beam diameter but only by the diameter of the X-ray emission volume. One of the advantages of the FE Source is to obtain fine focused electron beam at low beam voltage (?10 keV) while maintaining high and stable beam current. In these experimental conditions, the penetration depth of the primary electrons and thus the interaction volume- in which electrons are scattered and generate X-rays- decreases to sub-?m scale (compared to micron scale of the traditional Electron Microprobe at 15 or 20 keV). Thanks to WDS spectrometers with sub 10eV energy resolution, accurate quantitative analysis can be achieved even on sub micron phases at low beam energy and high lateral resolution using L- and M-Lines for heavy elements. This will be illustrated, in a first example, by measuring different areas in a Monazite grain. U, Pb and Th are quantitatively analyzed with high precision in order to characterize age domains. PIC PIC In the above example, several generations of monazite growth are represented in the quantified high-resolution X-ray maps. Of foremost interest is the high Y rim and fracture filling monazite (ca. ~1800 Ma) which has penetrated much older monazite (ca. ~2400 Ma). (Monazite from Boothia Peninsula, Nunavut, Canadian Artic) In a second example, quantification of small refractory phases (hibonite, grossite, perovskite, ...) formed by gas condensation in the solar nebula will be presented. Paris Meteorite is a stone classified by the Muséum National d'Histoire Naturelle as a CM chondrite. It contains chondrules and Calcium-aluminum-rich inclusions (CAI). These latter are materials formed at nearly the same time as the solar system i.e. 4.56 billion years ago. PIC PIC

Ehrke, Hans-Ulrich; Hombourger, Chrystel; Outrequin, Michel

2014-05-01

61

Electron beam chemistry produces high purity metals  

NASA Technical Reports Server (NTRS)

Application of radiation chemistry for deposition of metals by irradiation of aqueous solutions with high energy electrons is presented. Design of reaction vessel for irradiation of solution is illustrated. Features of radiochemical technique and procedures followed are described.

Philipp, W. H.; May, C. E.; Marsik, S. J.; Lad, R. A.

1972-01-01

62

Method for producing high dielectric strength microvalves  

DOEpatents

A microvalve having a cast-in-place and lithographically shaped mobile, polymer monolith for fluid flow control in microfluidic devices and method of manufacture. The microvalve contains a porous fluorinated polymer monolithic element whose pores are filled with an electrically insulating, high dielectric strength fluid, typically a perfluorinated liquid. This combination provides a microvalve that combines high dielectric strength with extremely low electrical conductivity. These microvalves have been shown to have resistivities of at least 100 G.OMEGA. and are compatible with solvents such as water at a pH between 2.7 and 9.0, 1-1 propanol, acetonitrile, and acetone.

Kirby, Brian J. (San Francisco, CA); Reichmuth, David S. (Oakland, CA); Shepodd, Timothy J. (Livermore, CA)

2006-04-04

63

Perovskite-based hybrid solar cells exceeding 10% efficiency with high reproducibility using a thin film sandwich approach.  

PubMed

Organometal halide perovskites have tremendous potential as light absorbers for photovoltaic applications. In this work we demonstrate hybrid solar cells based on the mixed perovskite CH3 NH3 PbI2 Cl in a thin film sandwich structure, with unprecedented reproducibility and generating efficiencies up to 10.8%. The successfulness of our approach is corroborated by the experimental electronic structure determination of this perovskite. PMID:24338932

Conings, Bert; Baeten, Linny; De Dobbelaere, Christopher; D'Haen, Jan; Manca, Jean; Boyen, Hans-Gerd

2014-04-01

64

Maternal origins of developmental reproducibility.  

PubMed

Cell fate decisions during multicellular development are precisely coordinated, leading to highly reproducible macroscopic structural outcomes [1-3]. The origins of this reproducibility are found at the molecular level during the earliest stages of development when patterns of morphogen molecules emerge reproducibly [4, 5]. However, although the initial conditions for these early stages are determined by the female during oogenesis, it is unknown whether reproducibility is perpetuated from oogenesis or reacquired by the zygote. To address this issue in the early Drosophila embryo, we sought to count individual maternally deposited bicoid mRNA molecules and compare variability between embryos with previously observed fluctuations in the Bicoid protein gradient [6, 7]. Here, we develop independent methods to quantify total amounts of mRNA in individual embryos and show that mRNA counts are highly reproducible between embryos to within ?9%, matching the reproducibility of the protein gradient. Reproducibility emerges from perfectly linear feedforward processes: changing the genetic dosage in the female leads to proportional changes in both mRNA and protein numbers in the embryo. Our results indicate that the reproducibility of the morphological structures of embryos originates during oogenesis, which is when the expression of maternally provided patterning factors is precisely controlled. PMID:24856210

Petkova, Mariela D; Little, Shawn C; Liu, Feng; Gregor, Thomas

2014-06-01

65

Highly reproducible and sensitive surface-enhanced Raman scattering from colloidal plasmonic nanoparticle via stabilization of hot spots in graphene oxide liquid crystal  

NASA Astrophysics Data System (ADS)

Although it is now well recognized that plasmonic gold/silver nanoparticle based aggregates having electromagnetic hot spots are responsible for high sensitivity in surface-enhanced Raman spectroscopy (SERS), the high yield and reproducible production of such nanostructures are challenging and limit their practical application. Here we show a graphene oxide (GO) based approach in generating stable electromagnetic hot spots with high yield from colloidal plasmonic nanoparticles that leads to highly reproducible, stable and sensitive SERS for a wide range of molecules with Raman enhancement factors between 108 to 1011. The liquid crystalline property of dispersed GO directs the Raman probe induced controlled aggregation of plasmonic particles, restricting those aggregates to small and discrete clusters and stabilizing those clusters for longer times--offering the Raman probe induced `turn on' SERS with high sensitivity and reproducibility. The presented approach is broadly applicable to different types of colloidal plasmonic particles and a wide range of Raman probes and is ideal for SERS based reliable detection of analyte at ultralow concentration.Although it is now well recognized that plasmonic gold/silver nanoparticle based aggregates having electromagnetic hot spots are responsible for high sensitivity in surface-enhanced Raman spectroscopy (SERS), the high yield and reproducible production of such nanostructures are challenging and limit their practical application. Here we show a graphene oxide (GO) based approach in generating stable electromagnetic hot spots with high yield from colloidal plasmonic nanoparticles that leads to highly reproducible, stable and sensitive SERS for a wide range of molecules with Raman enhancement factors between 108 to 1011. The liquid crystalline property of dispersed GO directs the Raman probe induced controlled aggregation of plasmonic particles, restricting those aggregates to small and discrete clusters and stabilizing those clusters for longer times--offering the Raman probe induced `turn on' SERS with high sensitivity and reproducibility. The presented approach is broadly applicable to different types of colloidal plasmonic particles and a wide range of Raman probes and is ideal for SERS based reliable detection of analyte at ultralow concentration. Electronic supplementary information (ESI) available: Results of different control experiments on SERS signal dependence with time/different sets of experiments, UV-visible spectra and TEM of different colloidal plasmonic particles used for this study, peak assignment of different biomolecules, details of EF calculation, SERS/Raman spectra used for EF calculations. See DOI: 10.1039/c2nr31035j

Saha, Arindam; Palmal, Sharbari; Jana, Nikhil R.

2012-09-01

66

On the acquisition of +1 charge states during high-throughput proteomics: Implications on reproducibility, number and confidence of protein identifications  

Microsoft Academic Search

Modern high-throughput methods for the proteome analysis are gradually replacing more traditional 2D gel-based techniques. Almost immediately after the introduction of high-throughput proteomics techniques in 2001, reproducibility of the results became an issue. Extensive discussion in the literature led to the conclusion that certain “undersampling” exhibited during measurements could be due to the stochastic nature of the data-dependent sampling, routinely

Victor J. Nesatyy; Ksenia Groh; Holger Nestler; Marc J.-F. Suter

2009-01-01

67

High-precision, cost-effective cutting system for producing thin sections of oral tissues containing dental implants  

Microsoft Academic Search

A new high-precision, cost-effective cutting system, able to produce thin (20–30 ?m) sections of oral tissues, containing dental implants, is presented. With this system the authors have been able to obtain, in a reproducible and consistent way, thin slides containing biomaterials and biological tissues. Very high cellular detail was possible, even at high magnifications (× 1200). Histochemical reactions (e.g. acid

A. Piattelli; A. Scarano; M. Quaranta

1997-01-01

68

High resolution computed tomographic assessment of airway wall thickness in chronic asthma: reproducibility and relationship with lung function and severity  

PubMed Central

Background: In some patients chronic asthma results in irreversible airflow obstruction. High resolution computed tomography (HRCT) has been advocated for assessing the structural changes in the asthmatic lung and permits investigation of the relationships between airway wall thickening and clinical parameters in this condition. Methods: High resolution CT scanning was performed in 49 optimally controlled asthmatic patients and measurements of total airway and lumen diameter were made by two independent radiologists using electronic callipers. Wall area as % total airway cross sectional area (WA%) and wall thickness to airway diameter ratio (T/D) were calculated for all airways clearly visualised with a transverse diameter of more than 1.5 mm, with a mean value derived for each patient. Intra- and inter-observer variability was assessed for scope of agreement in a subgroup of patients. Measurements were related to optimum forced expiratory volume in 1 second (FEV1), forced mid expiratory flow, carbon monoxide gas transfer, two scores of asthma severity, airway inflammation as assessed with induced sputum, and exhaled nitric oxide. Results: Neither observer produced a statistically significant difference between measurements performed on two occasions but there was a significant difference between observers (limits of agreement –2.6 to 6.8 for WA%, p<0.0001). However, mean WA% measured on two occasions differed by no more than 5.4% (limits of agreement –4.0 to 5.4; mean (SD) 0.7 (2.4)). Statistically significant positive associations were observed between both WA% and T/D ratio and asthma severity (rS=0.29 and 0.30, respectively, for ATS score), and an inverse association with gas transfer coefficient was observed (rS=–0.43 for WA% and rS=–0.41 for T/D). No association was identified with FEV1 or airway inflammation. Conclusions: The airway wall is thickened in more severe asthma and is associated with gas transfer coefficient. This thickening does not relate directly to irreversible airflow obstruction as measured with FEV1.

Little, S; Sproule, M; Cowan, M; Macleod, K; Robertson, M; Love, J; Chalmers, G; McSharry, C; Thomson, N

2002-01-01

69

Three Types of Cable Sheath Produced by High Frequency Welding.  

National Technical Information Service (NTIS)

With the THERMATOOL high frequency resistance welding technique, three basic types of cable sheath welds can be produced in a variety of metals. All of the welds are continuous and do not involve the addition of any metal. They are all produced at speeds ...

W. C. Rudd

1966-01-01

70

Miniature bioreactors for automated high-throughput bioprocess design (HTBD): reproducibility of parallel fed-batch cultivations with Escherichia coli.  

PubMed

To verify the reproducibility of cultivations of Escherichia coli in novel millilitre-scale bioreactors, fully automated fed-batch cultivation was performed in seven parallel-operated ml-scale bioreactors with an initial volume of 10 ml/reactor. The process was automatically controlled by a liquid-handling system responsible for glucose feeding, titration and sampling. Atline analysis (carried out externally of the reaction vessel with a short time delay) comprised automated pH and attenuance measurements. The partial pressure of oxygen (pO2) was measured online by a novel fluorimetric sensor block measuring the fluorescence lifetime of fluorophors immobilized inside the millilitre-scale bioreactors. Within a process time of 14.6 h, the parallel cultivation yielded a dry cell weight of 36.9+/-0.9 g.l(-1). Atline pH measurements were characterized by an S.D. of <1.1% throughout the process. Computational-fluid-dynamics simulation of single-phase flow yields a mean power input of 21.9 W.l(-1) at an impeller speed of 2800 rev./min corresponding to a power number (NP) of 3.7. PMID:15853771

Puskeiler, Robert; Kusterer, Andreas; John, Gernot T; Weuster-Botz, Dirk

2005-12-01

71

Method for producing high quality thin layer films on substrates  

DOEpatents

A method for producing high quality, thin layer films of inorganic compounds upon the surface of a substrate is disclosed. The method involves condensing a mixture of preselected molecular precursors on the surface of a substrate and subsequently inducing the formation of reactive species using high energy photon or charged particle irradiation. The reactive species react with one another to produce a film of the desired compound upon the surface of the substrate.

Strongin, Myron (Center Moriches, NY); Ruckman, Mark (Middle Island, NY); Strongin, Daniel (Port Jefferson, NY)

1994-01-01

72

Method for producing high quality thin layer films on substrates  

DOEpatents

A method for producing high quality, thin layer films of inorganic compounds upon the surface of a substrate is disclosed. The method involves condensing a mixture of preselected molecular precursors on the surface of a substrate and subsequently inducing the formation of reactive species using high energy photon or charged particle irradiation. The reactive species react with one another to produce a film of the desired compound upon the surface of the substrate. 4 figures.

Strongin, M.; Ruckman, M.; Strongin, D.

1994-04-26

73

Highly reproducible SERS detection in sequential injection analysis: real time preparation and application of photo-reduced silver substrate in a moving flow-cell.  

PubMed

This paper reports an improved way for performing highly reproducible surface enhanced Raman scattering of different analytes using an automated flow system. The method uses a confocal Raman microscope to prepare SERS active silver spots on the window of a flow cell by photo-reduction of silver nitrate in the presence of citrate. Placement of the flow cell on an automated x and y stages of the Raman microscope allows to prepare a fresh spot for every new measurement. This procedure thus efficiently avoids any carry over effects which might result from adsorption of the analyte on the SERS active material and enables highly reproducible SERS measurements. For reproducible liquid handling the used sequential injection analysis system as well as the Raman microscope was operated by the flexible LabVIEW based software ATLAS developed in our group. Quantitative aspects were investigated using Cu(PAR)2 as a model analyte. Concentration down to 5×10(-6) M provided clear SERS spectra, a linear concentration dependence of the SERS intensities at 1333 cm(-1) was obtained from 5×10(-5) to 1×10(-3) with a correlation coefficient r=0.999. The coefficient of variation of the method Vxo was found to be 5.6% and the calculated limit of detection 1.7×10(-5) M. The results demonstrate the potential of SERS spectroscopy to be used as a molecular specific detector in aqueous flow systems. PMID:24148503

El-Zahry, Marwa R; Genner, Andreas; Refaat, Ibrahim H; Mohamed, Horria A; Lendl, Bernhard

2013-11-15

74

Quartz-Seq: a highly reproducible and sensitive single-cell RNA sequencing method, reveals non-genetic gene-expression heterogeneity  

PubMed Central

Development of a highly reproducible and sensitive single-cell RNA sequencing (RNA-seq) method would facilitate the understanding of the biological roles and underlying mechanisms of non-genetic cellular heterogeneity. In this study, we report a novel single-cell RNA-seq method called Quartz-Seq that has a simpler protocol and higher reproducibility and sensitivity than existing methods. We show that single-cell Quartz-Seq can quantitatively detect various kinds of non-genetic cellular heterogeneity, and can detect different cell types and different cell-cycle phases of a single cell type. Moreover, this method can comprehensively reveal gene-expression heterogeneity between single cells of the same cell type in the same cell-cycle phase.

2013-01-01

75

How Do Beetles Reproduce?  

NSDL National Science Digital Library

Every living thing must be able to reproduce and make offspring. Most of us are familiar with how humans and mammals make babies, but do all creatures reproduce in the same way? Do insects, like the beetle, give birth to little insects? Also in: Français | Español

Drnevich, Jenny

2009-07-02

76

Preliminary Results of High Resolution Regional Climate Simulations in EC FP6 Project CECILIA: Impact of High Resolution on Reproducing Extremes  

NASA Astrophysics Data System (ADS)

Project EC FP6 CECILIA - Central and Eastern Europe Climate Change Impact and Vulnerability Assessment is studying the impact of climate change in complex topography of the Central and Eastern Europe in high resolution. The impacts on agriculture, forestry, hydrology and air-quality are studied. Resolution of regional climate simulation is an important factor affecting the accuracy of dynamical downscaling of the global changes. Especially the extremes are strongly dependent on the terrain patterns as shape of orography or land use, which can contribute to extreme temperatures or precipitation appearance. Here the preliminary results of ERA40 reanalysis run at 10 km will be compared to previous results at 45 km from the experiment launched in connection to 2002 floods in Czech Republic, where we started to analyze whether RCMs are capable to reproduce extremes that can be quite important feature of changing climate. The experiments are compared in terms of mean temperature and extremes, other characteristics as the days with characteristic temperatures and heatwaves are analized as well. Some precipitation characteristics are compared, too. In the comparison to the real station data for Czech Republic it can be seen there is quite good agreement for 10 km simulation in temperature characteristics, there are still some problems with overestimation of small precipitation and underestimation of high precipitation by the model. The test of double nesting vs. direct forcing by reanalysis will be presented, on the selcted domain of quite big size the benefit of the double nesting can be seen against the results with direct driving of the model by ERA40 data.

Halenka, T.; Belda, M.; Miksovsky, J.

2007-12-01

77

Assembly of polymer-gold nanostructures with high reproducibility into a monolayer film SERS substrate with 5 nm gaps for pesticide trace detection.  

PubMed

A very simple and versatile polymer assembly approach was developed. We use methoxy-mercapto-poly(ethylene glycol) (mPEG-SH) to conjugate multiple Au shapes to form dense Au monolayer films (MLFs) with 5 nm gaps and generate gigantic enhancement. The results of the discrete dipole approximation (DDA) method to calculate the local electric field distribution of the nanoparticle dimer are in agreement with the experimental data of sensitivity of multiple Au MLFs. 3D Raman spectra, relative standard deviation (RSD) calculation and Raman mapping were used to study the high-reproducibility of the assembled substrate, which is sufficient for trace pesticide residue detection. PMID:23912071

Zhou, Xia; Zhou, Fei; Liu, Honglin; Yang, Liangbao; Liu, Jinhuai

2013-10-01

78

Reproducible, Ultra High-Throughput Formation of Multicellular Organization from Single Cell Suspension-Derived Human Embryonic Stem Cell Aggregates  

PubMed Central

Background Human embryonic stem cells (hESC) should enable novel insights into early human development and provide a renewable source of cells for regenerative medicine. However, because the three-dimensional hESC aggregates [embryoid bodies (hEB)] typically employed to reveal hESC developmental potential are heterogeneous and exhibit disorganized differentiation, progress in hESC technology development has been hindered. Methodology/Principal Findings Using a centrifugal forced-aggregation strategy in combination with a novel centrifugal-extraction approach as a foundation, we demonstrated that hESC input composition and inductive environment could be manipulated to form large numbers of well-defined aggregates exhibiting multi-lineage differentiation and substantially improved self-organization from single-cell suspensions. These aggregates exhibited coordinated bi-domain structures including contiguous regions of extraembryonic endoderm- and epiblast-like tissue. A silicon wafer-based microfabrication technology was used to generate surfaces that permit the production of hundreds to thousands of hEB per cm2. Conclusions/Significance The mechanisms of early human embryogenesis are poorly understood. We report an ultra high throughput (UHTP) approach for generating spatially and temporally synchronised hEB. Aggregates generated in this manner exhibited aspects of peri-implantation tissue-level morphogenesis. These results should advance fundamental studies into early human developmental processes, enable high-throughput screening strategies to identify conditions that specify hESC-derived cells and tissues, and accelerate the pre-clinical evaluation of hESC-derived cells.

Ungrin, Mark D.; Joshi, Chirag; Nica, Andra; Bauwens, Celine; Zandstra, Peter W.

2008-01-01

79

High yield method of producing pure rebaudioside A  

US Patent & Trademark Office Database

The invention provides a high throughput, high purity, high yield system and method of isolating and purifying rebaudioside A ("Reb A"), with acceptable water solubility for all commercial uses, from commercially available Stevia rebaudiana starting material. The invention also provides a means of maximizing yields of 99+% purity Reb A based on the attributes of a given batch of Stevia starting material. The Reb A produced by the invention is water soluble, devoid of bitterness heretofore associated with rebaudioside sweeteners, non-caloric, and suitable for use as a reagent and as an ingredient in orally consumed products, e.g., as a sweetener, flavor enhancer, and flavor modifier.

2011-04-12

80

Particle longitudinal diffusion produced by a High Frequency Cavity  

SciTech Connect

A High Frequency Cavity (HFC) can be a powerful tool for the reduction of particle losses during the energy passage through the ..gamma..-transition in proton synchrotrons, via bunch dilution. In this paper we consider some aspects of bunch dilution. With an appropriately chosen frequency of phase modulation, the HFC can produce parametric resonance for particles near the bunch center. As a result, the process of dilution can be accelerated.

Kats, J.M.

1987-01-01

81

Breeding of high ergosterol-producing yeast strains  

Microsoft Academic Search

  High ergosterol-producing yeast strains YEH-28 and YEH-56 were constructed by hybridization of two haploids with opposite\\u000a mating types from different species. The fermentation conditions of hybrid strain YEH-56 were studied. The highest level of\\u000a ergosterol was obtained in 30 h at 28°C and 200 rpm, when 60 ml of culture in 250-ml shake flasks was grown in fermentation\\u000a medium that

X He; W Huai; C Tie; Y Liu; B Zhang

2000-01-01

82

Process of producing gases having a high calorific value  

Microsoft Academic Search

In the production of a gas having a high calorific value and containing more than about 50% methane by volume by a process comprising gasifying a solid fuel under a pressure of about 5 to 150 bars by a treatment with oxygen and water vapor to produce a water vapor-containing raw gas at a temperature of about 350° to 700°C,

G. Baron; H. Bierbach; C. Hafke; G. Pockrandt

1978-01-01

83

Deposition method for producing silicon carbide high-temperature semiconductors  

DOEpatents

An improved deposition method for producing silicon carbide high-temperature semiconductor material comprising placing a semiconductor substrate composed of silicon carbide in a fluidized bed silicon carbide deposition reactor, fluidizing the bed particles by hydrogen gas in a mildly bubbling mode through a gas distributor and heating the substrate at temperatures around 1200.degree.-1500.degree. C. thereby depositing a layer of silicon carbide on the semiconductor substrate.

Hsu, George C. (La Crescenta, CA); Rohatgi, Naresh K. (W. Corine, CA)

1987-01-01

84

[Tobacco--a highly efficient producer of vaccines].  

PubMed

Along with the depreciation of tobacco as a source of nicotine-containing commercial products, the increase of its appreciation as a potential producer of recombinant therapeutical proteins can be observed. Two species of tobacco--Nicotiana tabacum L. and N. benthamiana are easily grown by well established methods of field or green-house cultivation or cell culture, yield high biomass and soluble protein content, can be easily transformed by several methods and are not food for humans or feed for animals. Expression of foreign proteins, including vaccines, can be achieved in those plants either through stable transformation of nuclear or plastid (chloroplast) genomes or by transient transformation using infection with plant virus or bacteria--Agrobacterium tumefaciens (agroinfiltration). The most advanced mode of agrofiltration termed magnifection, which combines benefits of virus and Agrobacterium and depends on using Agrobacterium with viral pro-vectors, enables high-yield and rapid expression of therapeutical proteins, even in a few days, and can be employed on an industrial scale. Expression of many antigenic proteins, which may serve as antiviral, antibacterial, antiprotozoan and anticancer vaccines, and additionally a few autoantigens designed for the treatment of autoimunogenic diseases, like diabetes, have been achieved in tobacco. To date, a vaccine against Newcastle virus disease in poultry produced by tobacco cell culture has been approved for commercial application and several other vaccines are in advanced stage of development. The possibility of a high-level production of vaccines in tobacco against pandemic influenza or anthrax and plague due to a bioterroristic attack, as well as of individualised anticancer vaccines against non-Hodgkin's lymphoma (NHL) in a much shorter period of time than by traditional methods became realistic and hence caused increased interest in tobacco as a high-efficient producer of vaccines not only of specialistic biotechnology firms but also a big pharmaceutical corporation and a department of defence. PMID:21360963

Budzianowski, Jaromir

2010-01-01

85

Low and high velocity clouds produced by young stellar clusters  

NASA Astrophysics Data System (ADS)

Context: Intermediate and high velocity HI clouds rain onto the plane of our Galaxy. They are observed at heights of between 500 and 1500 pc, falling onto the Galactic plane at velocities from 50 to 140 km s-1. Aims: To explain the origin of these clouds, we present a galactic fountain model, driven by the wind from a super stellar cluster (SSC). Methods: We solve the equations for a steady, radiative de Laval nozzle flow. We consider two effects not considered previously in astrophysical nozzle flow models: cooling functions for different metallicities, and the direct action of the galactic gravitational field on the gas flowing along the nozzle. Results: For an adiabatic nozzle flow, the gravity acting directly on the gas within the nozzle “stalls” the nozzle flow for initial wind velocities lower than the escape velocity from the Galaxy. For the same wind velocity, a radiative nozzle flow stalls at lower altitudes above the galactic plane. We find that SSC winds with velocities of vw = 500-800 km s-1 produce nozzles stall at heights of xm = 1-15 kpc. The stalled nozzle flow then rains back onto the galactic plane at velocities in the range observed in intermediate and high velocity HI clouds. Conclusions: We study a nozzle flow driven by a wind from a SSC close to the Galactic centre. We find that for velocities within the range expected for a SSC wind, we can produce nozzle flows that stall above the galactic plane. These stalled flows produce cool, infalling clouds with velocities similar to those of intermediate and high velocity HI clouds.

Rodríguez-González, A.; Raga, A. C.; Cantó, J.

2009-07-01

86

High surface area tapes produced with functionalized graphene.  

PubMed

We describe a scalable method for producing continuous graphene networks by tape casting surfactant-stabilized aqueous suspensions of functionalized graphene sheets. Similar to all other highly connected graphene-containing networks, the degree of overlap between the sheets controls the tapes' electrical and mechanical properties. However, unlike other graphene-containing networks, the specific surface area of the cast tapes remains high (>400 m(2)·g(-1)). Exhibiting apparent densities between 0.15 and 0.51 g·cm(-3), with electrical conductivities up to 24 kS·m(-1) and tensile strengths over 10 MPa, these tapes exhibit the best combination of properties with respect to density heretofore observed for carbon-based papers, membranes, or films. PMID:21545115

Korkut, Sibel; Roy-Mayhew, Joseph D; Dabbs, Daniel M; Milius, David L; Aksay, Ilhan A

2011-06-28

87

Adapting to blur produced by ocular high-order aberrations  

PubMed Central

The perceived focus of an image can be strongly biased by prior adaptation to a blurred or sharpened image. We examined whether these adaptation effects can occur for the natural patterns of retinal image blur produced by high-order aberrations (HOAs) in the optics of the eye. Focus judgments were measured for 4 subjects to estimate in a forced choice procedure (sharp/blurred) their neutral point after adaptation to different levels of blur produced by scaled increases or decreases in their HOAs. The optical blur was simulated by convolution of the PSFs from the 4 different HOA patterns, with Zernike coefficients (excluding tilt, defocus, and astigmatism) multiplied by a factor between 0 (diffraction limited) and 2 (double amount of natural blur). Observers viewed the images through an Adaptive Optics system that corrected their aberrations and made settings under neutral adaptation to a gray field or after adapting to 5 different blur levels. All subjects adapted to changes in the level of blur imposed by HOA regardless of which observer’s HOA was used to generate the stimuli, with the perceived neutral point proportional to the amount of blur in the adapting image.

Sawides, Lucie; de Gracia, Pablo; Dorronsoro, Carlos; Webster, Michael; Marcos, Susana

2011-01-01

88

Uniform metal nanoparticles produced at high yield in dense microemulsions.  

PubMed

This article demonstrates that bicontinuous microemulsions are optimal templates for high yield production of metal nanoparticles. We have verified this for a variety of microemulsion systems having AOT (sodium bis (2-ethyhexyl) sulphosuccinate) or a fluorocarbon (perfluoro (4-methyl-3,6-dioxaoctane)sulphonate) as surfactant mixed with water and oils like n-heptane or n-dodecane. Several types of metal nanoparticles, including platinum, gold and iron, were produced in these microemulsions having a size range spanning 1.8-17 nm with a very narrow size distribution of ±1 nm. Remarkably high mass concentrations up to 3% were reached. Size and concentration of the nanoparticles could be varied with the stoichiometries of the reagents that constituted them. The optimization towards high yield while maintaining low size polydispersity is due to the decoupling of the time scales for the precipitation reaction and for coarsening. In actual fact, coalescence is essentially prevented by the immobilization of nanoparticles within the bicontinuous microemulsion structure. PMID:22305574

Kowlgi, Krishna; Lafont, Ugo; Rappolt, Michael; Koper, Ger

2012-04-15

89

Laser-produced plasma in high-speed flows  

NASA Astrophysics Data System (ADS)

For the purpose of constructing the design rules of air- breathing laser launcher, the expansion of plasma, which was produced from air by focusing pulse laser, was investigated. A 10-J-pulse TEA CO2 laser was used for these experiments. First, plasma was formed in a quiescent atmospheric air. Photographs and shadowgraphs were taken using an ICCD camera with high-speed gating. From the photographs, the propagation velocity along the laser axis was measured. The velocity was found around 104 m/s much higher than that of a detonation wave calculated using LSD model. Since laser intensity at the plasma front was below the threshold for LSD regime, absorption/expansion mechanism other than LSD might predominate under the experimental condition. Shadowgraphs were taken to measure the expansion velocity of plasma and that of shock wave around plasma. The flow facility, in which plasma is formed in Mach 2 stream, was presented.

Mori, Koichi; Komurasaki, Kimiya; Arakawa, Yasuhiko

2001-04-01

90

Intra- and inter-examiner reproducibility of manual probing depth.  

PubMed

The periodontal probe remains the best clinical diagnostic tool for the collection of information regarding the health status and the attachment level of periodontal tissues. The aim of this study was to evaluate intra- and inter-examiner reproducibility of probing depth (PD) measurements made with a manual probe. With the approval of an Ethics Committee, 20 individuals without periodontal disease were selected if they presented at least 6 teeth per quadrant. Using a Williams periodontal probe, three calibrated thesis-level students (k > 0.6) assessed PD at 6 sites per tooth, from the gingival margin to the bottom of the periodontal sulcus (rounded to the next 0.5 mm). Initial and repeated measurements were performed by the same three examiners. The intra-examiner agreement (± 1 mm > 90%) was 99.85%, 100%, and 100% for the three examiners, respectively. When the variables vestibular/lingual surfaces, mesial/distal surfaces, or superior/inferior jaws were evaluated, no significant differences in reproducibility were detected at the inter-examiner level (p < 0.05). At this level, the only significant differences observed were in the three examiners' measurements of the anterior and posterior sites. While high intra-examiner reproducibility was detected, inter-examiner level proved to be low. We can conclude that measurement of PD with a manual periodontal probe produced high reproducibility in healthy individuals. The operators position can affect the reproducibility of repeated measures of PD. Calibration and operator training, rather than operator experience, were fundamental for reproducibility. Other factors, such as individual technique and probing depth force, can affect inter-examiner reproducibility. PMID:22344339

Andrade, Roberto; Espinoza, Manuel; Gómez, Elena Maria; Espinoza, José Rolando; Cruz, Elizabeth

2012-01-01

91

Processes for producing low cost, high efficiency silicon solar cells  

DOEpatents

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime {tau} and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime {tau} and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO{sub x}. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure. 28 figs.

Rohatgi, A.; Doshi, P.; Tate, J.K.; Mejia, J.; Chen, Z.

1998-06-16

92

Processes for producing low cost, high efficiency silicon solar cells  

DOEpatents

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. Silicon solar cell efficiencies of 16.9% have been achieved. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x.

Rohatgi, Ajeet (Marietta, GA); Chen, Zhizhang (Duluth, GA); Doshi, Parag (Atlanta, GA)

1996-01-01

93

Processes for producing low cost, high efficiency silicon solar cells  

DOEpatents

Processes which utilize rapid thermal processing (RTP) are provided for inexpensively producing high efficiency silicon solar cells. The RTP processes preserve minority carrier bulk lifetime .tau. and permit selective adjustment of the depth of the diffused regions, including emitter and back surface field (bsf), within the silicon substrate. In a first RTP process, an RTP step is utilized to simultaneously diffuse phosphorus and aluminum into the front and back surfaces, respectively, of a silicon substrate. Moreover, an in situ controlled cooling procedure preserves the carrier bulk lifetime .tau. and permits selective adjustment of the depth of the diffused regions. In a second RTP process, both simultaneous diffusion of the phosphorus and aluminum as well as annealing of the front and back contacts are accomplished during the RTP step. In a third RTP process, the RTP step accomplishes simultaneous diffusion of the phosphorus and aluminum, annealing of the contacts, and annealing of a double-layer antireflection/passivation coating SiN/SiO.sub.x. In a fourth RTP process, the process of applying front and back contacts is broken up into two separate respective steps, which enhances the efficiency of the cells, at a slight time expense. In a fifth RTP process, a second RTP step is utilized to fire and adhere the screen printed or evaporated contacts to the structure.

Rohatgi, Ajeet (Marietta, GA); Doshi, Parag (Altanta, GA); Tate, John Keith (Lawrenceville, GA); Mejia, Jose (Atlanta, GA); Chen, Zhizhang (Duluth, GA)

1998-06-16

94

The tussometer: accuracy and reproducibility.  

PubMed

Tussometry is a new non-invasive technique for objectively assessing laryngeal function by analysis of the airflow waveform produced by a maximum effort voluntary cough manoeuvre. We describe the technique and present the calibration data. The tussometer has been calibrated for flows of up to 1100 litre min-1 using a flowmeter with a quoted accuracy of +/- 1.75%. The variables measured (cough peak flow rate (CPFR) and peak velocity time (PVT)) were found to be reproducible; the within-subject variability for CPFR was found to be 23.9% and for PVT 9%. There was no inter-observer variation. We found that the size of the mask used did not influence the readings obtained, providing an adequate seal was achieved. PMID:7917725

Singh, P; Murty, G E; Mahajan, R P; Knights, D; Aitkenhead, A R

1994-08-01

95

A light hydrocarbon fuel processor producing high-purity hydrogen  

NASA Astrophysics Data System (ADS)

This paper discusses the design process and presents performance data for a dual fuel (natural gas and LPG) fuel processor for PEM fuel cells delivering between 2 and 8 kW electric power in stationary applications. The fuel processor resulted from a series of design compromises made to address different design constraints. First, the product quality was selected; then, the unit operations needed to achieve that product quality were chosen from the pool of available technologies. Next, the specific equipment needed for each unit operation was selected. Finally, the unit operations were thermally integrated to achieve high thermal efficiency. Early in the design process, it was decided that the fuel processor would deliver high-purity hydrogen. Hydrogen can be separated from other gases by pressure-driven processes based on either selective adsorption or permeation. The pressure requirement made steam reforming (SR) the preferred reforming technology because it does not require compression of combustion air; therefore, steam reforming is more efficient in a high-pressure fuel processor than alternative technologies like autothermal reforming (ATR) or partial oxidation (POX), where the combustion occurs at the pressure of the process stream. A low-temperature pre-reformer reactor is needed upstream of a steam reformer to suppress coke formation; yet, low temperatures facilitate the formation of metal sulfides that deactivate the catalyst. For this reason, a desulfurization unit is needed upstream of the pre-reformer. Hydrogen separation was implemented using a palladium alloy membrane. Packed beds were chosen for the pre-reformer and reformer reactors primarily because of their low cost, relatively simple operation and low maintenance. Commercial, off-the-shelf balance of plant (BOP) components (pumps, valves, and heat exchangers) were used to integrate the unit operations. The fuel processor delivers up to 100 slm hydrogen >99.9% pure with <1 ppm CO, <3 ppm CO 2. The thermal efficiency is better than 67% operating at full load. This fuel processor has been integrated with a 5-kW fuel cell producing electricity and hot water.

Löffler, Daniel G.; Taylor, Kyle; Mason, Dylan

96

Immuno-MS based targeted proteomics: highly specific, sensitive, and reproducible human chorionic gonadotropin determination for clinical diagnostics and doping analysis.  

PubMed

The human chorionic gonadotropin (hCG) proteins constitute a diverse group of molecules that displays biomarker value in pregnancy detection and cancer diagnostics, as well as in doping analysis. For the quantification of hCG? and qualitative differentiation between other hCG variants in a selective, sensitive, and reproducible manner, the targeted proteomics approach based on mass spectrometric (MS) selected reaction monitoring (SRM) detection was exploited. By optimizing immunoaffinity extraction using monoclonal antibodies coated to magnetic beads, access was granted for the MS to the low-abundance target proteins, ensuring proper sensitivity with limits of detection (LODs) of 2 and 5 IU/L, respectively, for urine and serum samples. Validation according to key elements and recommendations defined by the European Medicines Agency in Guideline on Validation of Bioanalytical Methods was performed. For both matrixes this demonstrated good within-day precision results (within 20% for the lowest concentration, and within 15% for the medium and high concentration), good accuracy results (within 15% for all concentrations), and proper linearity, >0.997 for serum and of 0.999 for urine, in the concentration range up to 5000 IU/L. The method's application in clinical diagnostics was tested on samples from a pregnant woman and from patients previously diagnosed with testicular cancer. For doping analysis, samples from one man having received injection of the hCG-containing pharmaceutical Pregnyl were analyzed. The method proved to be quantitatively accurate with indisputable identification specificity, reducing risks of false positive and false negative results. The successfully validated method advocates thus for more extended use of MS in routine analysis. PMID:22894612

Lund, Hanne; Løvsletten, Karoline; Paus, Elisabeth; Halvorsen, Trine Grønhaug; Reubsaet, Léon

2012-09-18

97

Solar-Power System Produces High-Pressure Steam  

NASA Technical Reports Server (NTRS)

Combination of three multistaged solar collectors produces highpressure steam for large-scale continuously operating turbines for generating mechanical or electrical energy. Superheated water vapor drives turbines, attaining an overall system efficiency about 22 percent.

Lansing, F. L.

1985-01-01

98

Method for producing high surface area chromia materials for catalysis  

DOEpatents

Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

Gash, Alexander E. (Brentwood, CA); Satcher, Joe (Patterson, CA); Tillotson, Thomas (Tracy, CA); Hrubesh, Lawrence (Pleasanton, CA); Simpson, Randall (Livermore, CA)

2007-05-01

99

Diagnostics of Shiva Nova produced high yield thermonuclear events  

SciTech Connect

Experiments with the Shiva Nova laser facility which produce yield levels of scientific breakeven and above will result in neutron, x-ray and particle fluxes which will require specific attention to the survivability of diagnostic instrumentation. These yield levels will also allow the utilization of new diagnotics techniques which can provide detailed information on the state of the imploded fuel and pusher shells.

Ahlstrom, H.G.; Banner, D.L.; Boyle, M.J.; Campbell, E.M.; Coleman, L.W.; Koppel, L.N.; Kornblum, H.N. Jr.; Rienecker, F.; Severyn, J.R.; Slivinsky, V.W.

1978-01-01

100

High gain CO chemical laser produced in a shock tunnel  

Microsoft Academic Search

Experimental theoretical results are presented of small signal gain in a CO chemical laser produced in a shock tunnel. The thermal dissociation of CS2 into CS + S is effected by a reflected shock wave. The dissociated products, diluted in Ar, expand through a supersonic nozzle having an area ratio of 40 into a combustion chamber. At the nozzle exit,

M. Tilleman; J. Stricker

1982-01-01

101

High capacity adsorption media and method of producing  

DOEpatents

A method of producing an adsorption medium to remove at least one constituent from a feed stream. The method comprises dissolving and/or suspending at least one metal compound in a solvent to form a metal solution, dissolving polyacrylonitrile into the metal solution to form a PAN-metal solution, and depositing the PAN-metal solution into a quenching bath to produce the adsorption medium. The at least one constituent, such as arsenic, selenium, or antimony, is removed from the feed stream by passing the feed stream through the adsorption medium. An adsorption medium having an increased metal loading and increased capacity for arresting the at least one constituent to be removed is also disclosed. The adsorption medium includes a polyacrylonitrile matrix and at least one metal hydroxide incorporated into the polyacrylonitrile matrix.

Tranter, Troy J. (Idaho Falls, ID); Mann, Nicholas R. (Blackfoot, ID); Todd, Terry A. (Aberdeen, ID); Herbst, Ronald S. (Idaho Falls, ID)

2010-10-05

102

Reproducibility in a multiprocessor system  

DOEpatents

Fixing a problem is usually greatly aided if the problem is reproducible. To ensure reproducibility of a multiprocessor system, the following aspects are proposed; a deterministic system start state, a single system clock, phase alignment of clocks in the system, system-wide synchronization events, reproducible execution of system components, deterministic chip interfaces, zero-impact communication with the system, precise stop of the system and a scan of the system state.

Bellofatto, Ralph A; Chen, Dong; Coteus, Paul W; Eisley, Noel A; Gara, Alan; Gooding, Thomas M; Haring, Rudolf A; Heidelberger, Philip; Kopcsay, Gerard V; Liebsch, Thomas A; Ohmacht, Martin; Reed, Don D; Senger, Robert M; Steinmacher-Burow, Burkhard; Sugawara, Yutaka

2013-11-26

103

Molecular Crowding of Collagen: A Pathway to Produce Highly-Organized Collagenous Structures  

PubMed Central

Collagen in vertebrate animals is often arranged in alternating lamellae or in bundles of aligned fibrils which are designed to withstand in vivo mechanical loads. The formation of these organized structures is thought to result from a complex, large-area integration of individual cell motion and locally-controlled synthesis of fibrillar arrays via cell-surface fibripositors (direct matrix printing). The difficulty of reproducing such a process in vitro has prevented tissue engineers from constructing clinically useful load-bearing connective tissue directly from collagen. However, we and others have taken the view that long-range organizational information is potentially encoded into the structure of the collagen molecule itself, allowing the control of fibril organization to extend far from cell (or bounding) surfaces. We here demonstrate a simple, fast, cell-free method capable of producing highly-organized, anistropic collagen fibrillar lamellae de novo which persist over relatively long-distances (tens to hundreds of microns). Our approach to nanoscale organizational control takes advantage of the intrinsic physiochemical properties of collagen molecules by inducing collagen association through molecular crowding and geometric confinement. To mimic biological tissues which comprise planar, aligned collagen lamellae (e.g. cornea, lamellar bone or annulus fibrosus), type I collagen was confined to a thin, planar geometry, concentrated through molecular crowding and polymerized. The resulting fibrillar lamellae show a striking resemblance to native load-bearing lamellae in that the fibrils are small, generally aligned in the plane of the confining space and change direction en masse throughout the thickness of the construct. The process of organizational control is consistent with embryonic development where the bounded planar cell sheets produced by fibroblasts suggest a similar confinement/concentration strategy. Such a simple approach to nanoscale organizational control of structure not only makes de novo tissue engineering a possibility, but also suggests a clearer pathway to organization for fibroblasts than direct matrix printing.

Saeidi, Nima; Karmelek, Kathryn N.; Paten, Jeffrey. A; Zareian, Ramin; DiMasi, Elaine

2013-01-01

104

FORMATION OF COSMIC CRYSTALS IN HIGHLY SUPERSATURATED SILICATE VAPOR PRODUCED BY PLANETESIMAL BOW SHOCKS  

SciTech Connect

Several lines of evidence suggest that fine silicate crystals observed in primitive meteorite and interplanetary dust particles (IDPs) nucleated in a supersaturated silicate vapor followed by crystalline growth. We investigated evaporation of {mu}m-sized silicate particles heated by a bow shock produced by a planetesimal orbiting in the gas in the early solar nebula and condensation of crystalline silicate from the vapor thus produced. Our numerical simulation of shock-wave heating showed that these {mu}m-sized particles evaporate almost completely when the bow shock is strong enough to cause melting of chondrule precursor dust particles. We found that the silicate vapor cools very rapidly with expansion into the ambient unshocked nebular region; for instance, the cooling rate is estimated to be as high as 2000 K s{sup -1} for a vapor heated by a bow shock associated with a planetesimal of radius 1 km. The rapid cooling of the vapor leads to nonequilibrium gas-phase condensation of dust at temperatures much lower than those expected from the equilibrium condensation. It was found that the condensation temperatures are lower by a few hundred K or more than the equilibrium temperatures. This explains the results of the recent experimental studies of condensation from a silicate vapor that condensation in such large supercooling reproduces morphologies similar to those of silicate crystals found in meteorites. Our results strongly suggest that the planetesimal bow shock is one of the plausible sites for formation of not only chondrules but also other cosmic crystals in the early solar system.

Miura, H.; Yamada, J.; Tsukamoto, K.; Nozawa, J. [Department of Earth Sciences, Tohoku University, Aoba 6-3, Aramaki, Aoba-ku, Sendai 980-8578 (Japan); Tanaka, K. K.; Yamamoto, T. [Institute of Low Temperature Science, Hokkaido University, Sapporo 060-0819 (Japan); Nakamoto, T., E-mail: miurah@m.tohoku.ac.j [Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551 (Japan)

2010-08-10

105

Experimental challenges to reproduce seismic fault motion  

NASA Astrophysics Data System (ADS)

This presentation briefly reviews scientific and technical development in the studies of intermediate to high-velocity frictional properties of faults and summarizes remaining technical challenges to reproduce nucleation to growth processes of large earthquakes in laboratory. Nearly 10 high-velocity or low to high-velocity friction apparatuses have been built in the last several years in the world and it has become possible now to produce sub-plate velocity to seismic slip rate in a single machine. Despite spreading of high-velocity friction studies, reproducing seismic fault motion at high P and T conditions to cover the entire seismogenic zone is still a big challenge. Previous studies focused on (1) frictional melting, (2) thermal pressurization, and (3) high-velocity gouge behavior without frictional melting. Frictional melting process was solved as a Stefan problem with very good agreement with experimental results. Thermal pressurization has been solved theoretically based on measured transport properties and has been included successfully in the modeling of earthquake generation. High-velocity gouge experiments in the last several years have revealed that a wide variety of gouges exhibit dramatic weakening at high velocities (e.g., Di Toro et al., 2011, Nature). Most gouge experiments were done under dry conditions partly to separate gouge friction from the involvement of thermal pressurization. However, recent studies demonstrated that dehydration or degassing due to mineral decomposition can occur during seismic fault motion. Those results not only provided a new view of looking at natural fault zones in search of geological evidence of seismic fault motion, but also indicated that thermal pressurization and gouge weakening can occur simultaneously even in initially dry gouge. Thus experiments with controlled pore pressure are needed. I have struggled to make a pressure vessel for wet high-velocity experiments in the last several years. A technical difficulty was how to absorb hydrodynamic shock due to abrupt fault motion in the vessel, and this was overcome by pressurizing water in the vessel, acting as pore fluid, using pressurized gas (in other words using gas as a cushion). I will report preliminary experimental results on high-velocity rock-on-rock friction under pore-water pressure. Other technical challenges are (i) how to produce step-change in velocity to see if the framework of rate-and-state friction law holds in high-velocity regime, (ii) how to conduct high-velocity friction experiments in hydrothermal conditions to study frictional properties relevant to slow slip and low-frequency tremors, and (iii) how to conduct high-velocity friction experiments at high normal stresses. The first task became possible with a low to high-velocity apparatus in Beijing and a few other machines, and I will show some preliminary results. There is no fundamental difficulty in (ii) since O-ring is enough to seal piston rotating at a high speed. However, (iii) will be the hardest because of severe thermal fracturing of host rocks that limits the axial stress. Use of aluminum sleeve made it possible to apply the normal stress to about 30 MPa, but new device and a high motor power is needed to go higher normal stress.

Shimamoto, T.

2011-12-01

106

Process produces chlorinated aromatic isocyanate in high yield  

NASA Technical Reports Server (NTRS)

Tetrachloreterephthaloyl chloride reacts with sodium azide in an atmosphere of nitrogen to form a high yield of tetrachloro-p-phenylene diisocyanate. The chlorinated diisocyanate should have application as an intermediate in the preparation of polyurethane foams. The high halogen content would impart added flame resistance to these foams.

Trischler, F.

1966-01-01

107

High gain CO chemical laser produced in a shock tunnel  

NASA Astrophysics Data System (ADS)

Experimental theoretical results are presented of small signal gain in a CO chemical laser produced in a shock tunnel. The thermal dissociation of CS2 into CS + S is effected by a reflected shock wave. The dissociated products, diluted in Ar, expand through a supersonic nozzle having an area ratio of 40 into a combustion chamber. At the nozzle exit, molecular oxygen is injected supersonically. The two streams mix and combustion occurs where vibrationally excited CO is produced by the CS + O - CO (v) + S reaction. Gain measurements of the P7(14) line are made at distances of 5.5 and 11.5 cm downstream of the oxygen injection point, the stagnation pressure being 25 atm. The stagnation temperatures are varied in the range of 2500-4600 K and mixtures of CS2:Ar between 5:95 and 30:70 are tested. A maximum gain of 8% per cm is observed for CS2:Ar = 20:80 at a stagnation temperature of about 4000 K and a distance of 11.5 cm. A semiempirical model describing the fuel-diluent expansion through the supersonic nozzle and the fuel-oxidizer mixing process is then developed.

Tilleman, M.; Stricker, J.

108

Highly uniform and reproducible vertical-cavity surface-emitting lasers grown by metalorganic vapor phase epitaxy with in-situ reflectometry  

SciTech Connect

Vertical-cavity surface-emitting lasers (VCSELs) were grown by metalorganic vapor phase epitaxy. Excellent uniformity of Fabry-Perot cavity wavelength for VCSEL materials of {+-}0.2% across a 3-in diameter wafer was achieved. This results in excellent uniformity of the lasing wavelength and threshold current of VCSEL devices. Employing pregrowth calibrations on growth rates periodically with an in situ reflectometer, the authors obtained a run-to-run wavelength reproducibility for 770- and 850-nm VCSELs of {+-}0.3% over the course of more than a hundred runs.

Hou, H.Q.; Choquette, K.D.; Hammons, B.E.; Breiland, W.G.; Geib, K.M. [Sandia National Labs., Albuquerque, NM (United States)] [Sandia National Labs., Albuquerque, NM (United States); Chui, H.C. [Hewlett-Packard Co., San Jose, CA (United States)] [Hewlett-Packard Co., San Jose, CA (United States)

1996-10-01

109

Title: Technology to produce high energy biomass briquettes  

Microsoft Academic Search

Briquetting is a process that has the objective of concentrating the sparse energy of vegetable residues such as wood residues, rice husk, bagasse, etc., into high density particles of varied forms and sizes known as \\

M. P. Juan Miguel; F. E. F. Felfli; J. D. Rocha; C. A. Luengo

110

Composing with Images: A Study of High School Video Producers.  

ERIC Educational Resources Information Center

At Bell High School (Los Angeles, California), students have been using video cameras, computers and editing machines to create videos in a variety of forms and on a variety of topics; in this setting, video is the textual medium of expression. A study was conducted using participant-observation and interviewing over the course of one school year…

Reilly, Brian

111

Ticks produce highly selective chemokine binding proteins with antiinflammatory activity  

PubMed Central

Bloodsucking parasites such as ticks have evolved a wide variety of immunomodulatory proteins that are secreted in their saliva, allowing them to feed for long periods of time without being detected by the host immune system. One possible strategy used by ticks to evade the host immune response is to produce proteins that selectively bind and neutralize the chemokines that normally recruit cells of the innate immune system that protect the host from parasites. We have identified distinct cDNAs encoding novel chemokine binding proteins (CHPBs), which we have termed Evasins, using an expression cloning approach. These CHBPs have unusually stringent chemokine selectivity, differentiating them from broader spectrum viral CHBPs. Evasin-1 binds to CCL3, CCL4, and CCL18; Evasin-3 binds to CXCL8 and CXCL1; and Evasin-4 binds to CCL5 and CCL11. We report the characterization of Evasin-1 and -3, which are unrelated in primary sequence and tertiary structure, and reveal novel folds. Administration of recombinant Evasin-1 and -3 in animal models of disease demonstrates that they have potent antiinflammatory properties. These novel CHBPs designed by nature are even smaller than the recently described single-domain antibodies (Hollinger, P., and P.J. Hudson. 2005. Nat. Biotechnol. 23:1126–1136), and may be therapeutically useful as novel antiinflammatory agents in the future.

Deruaz, Maud; Frauenschuh, Achim; Alessandri, Ana L.; Dias, Joao M.; Coelho, Fernanda M.; Russo, Remo C.; Ferreira, Beatriz R.; Graham, Gerard J.; Shaw, Jeffrey P.; Wells, Timothy N.C.; Teixeira, Mauro M.; Power, Christine A.; Proudfoot, Amanda E.I.

2008-01-01

112

Lipidation of intact proteins produces highly immunogenic vaccine candidates  

Microsoft Academic Search

In this study we investigate the feasibility of generating self-adjuvanting vaccines capable of inducing high titre antibody responses following the covalent attachment of the TLR2 agonist Pam2Cys to intact proteins. Three Pam2Cys-based lipid moieties were prepared which contain a solubilising spacer composed of either lysine residues or polyethyleneglycol. A model protein, hen egg white lysozyme (HEL), was lipidated individually with

Weiguang Zeng; Emily M. Eriksson; Andrew Lew; David C. Jackson

2011-01-01

113

Method of producing high T(subc) superconducting NBN films  

NASA Technical Reports Server (NTRS)

Thin films of niobium nitride with high superconducting temperature (T sub c) of 15.7 K are deposited on substrates held at room temperature (approx 90 C) by heat sink throughout the sputtering process. Films deposited at P sub Ar 12.9 + or - 0.2 mTorr exhibit higher T sub c with increasing P sub N2,I with the highest T sub c achieved at P sub n2,I= 3.7 + or - 0.2 mTorr and total sputtering pressure P sub tot = 16.6 + or - 0.4. Further increase of N2 injection starts decreasing T sub c.

Thakoor, Sarita (inventor); Lamb, James L. (inventor); Thakoor, Anilkumar P. (inventor); Khanna, Satish K. (inventor)

1988-01-01

114

Material Science Developments Enhancing Excess of Power Reproducibility  

NASA Astrophysics Data System (ADS)

Material science research activities have been carried out in order to increase the reproducibility of the excess of power production during electrochemical loading of palladium with deuterium. In the past a wide work was developed to obtain a metallurgical structure of the palladium able to ensure a significant loading of deuterium above the threshold of 0.95 (D/Pd atomic fraction). It was observed that the high loading of the Pd cathode with deuterium was a necessary condition to have the occurrence of the excess of power production. The more recent work was mainly oriented to optimize the material properties in order to have a significant improvement of the reproducibility of the excess of power. During the last campaign of experiments more than 50% of the experienced cathodes produced excess of heat ranging from 30% up to more than 100% of the input.

Violante, V.; Bertolotti, M.; Castagna, E.; McKubre, M.; Sarto, F.; Sibilia, C.; Tanzella, F.; Zilov, T.

2007-03-01

115

High quality optically polished aluminum mirror and process for producing  

NASA Technical Reports Server (NTRS)

A new technical advancement in the field of precision aluminum optics permits high quality optical polishing of aluminum monolith, which, in the field of optics, offers numerous benefits because of its machinability, lightweight, and low cost. This invention combines diamond turning and conventional polishing along with india ink, a newly adopted material, for the polishing to accomplish a significant improvement in surface precision of aluminum monolith for optical purposes. This invention guarantees the precise optical polishing of typical bare aluminum monolith to surface roughness of less than about 30 angstroms rms and preferably about 5 angstroms rms while maintaining a surface figure accuracy in terms of surface figure error of not more than one-fifteenth of wave peak-to-valley.

Lyons, III, James J. (Inventor); Zaniewski, John J. (Inventor)

2005-01-01

116

High quality optically polished aluminum mirror and process for producing  

NASA Technical Reports Server (NTRS)

A new technical advancement in the field of precision aluminum optics permits high quality optical polishing of aluminum monolith, which, in the field of optics, offers numerous benefits because of its machinability, lightweight, and low cost. This invention combines diamond turning and conventional polishing along with india ink, a newly adopted material, for the polishing to accomplish a significant improvement in surface precision of aluminum monolith for optical purposes. This invention guarantees the precise optical polishing of typical bare aluminum monolith to surface roughness of less than about 30 angstroms rms and preferably about 5 angstroms rms while maintaining a surface figure accuracy in terms of surface figure error of not more than one-fifteenth of wave peak-to-valley.

Lyons, III, James J. (Inventor); Zaniewski, John J. (Inventor)

2002-01-01

117

High pressure polymorphs produced by the shock transformation of coals  

SciTech Connect

Impact glasses from meteorite craters often contain high pressure polymorphic modifications derived from quartz, graphite, and other minerals. The transformation of carbonaceous material under these conditions remained unknown until recently. This lends interest to impactites from the melting of low-grade metamorphic rocks (polymict sandstones, shales, and so on) containing coals of various rank. Such impactites (suevites and tagamites) consist mainly of altered impact glasses but contain fragments of shock-metamorphosed and other rocks, among which are sediments containing fragments of coals of ranks T-A. The overall chemical compositions of the impactites are close to those of the corresponding target rocks: SiO/sub 2/ 57-59%, Al/sub 2/O/sub 3/ 13-17%, FeO + Fe/sub 2/O/sub 3/ 5.6-7.2%, MgO 3.8-4.5%, CaO 3.7-5.8%, Na/sub 2/O + K/sub 2/O 3.8-5.6%, and other components. This paper describes a series of shock-transformed coals from an unnamed impact structure (presumably Popigay), which includes types very similar to carbonado. The origin of carbonado diamond has never been clear, and Yezerskiy suggests it may be an impact product. 26 references.

Ezerskiy, V.A.

1986-02-01

118

Characterization of uniformity and reproducibility of photoresist nanomasks fabricated by near-field scanning optical nanolithography.  

PubMed

The uniformity and reproducibility of the photoresist nanopatterns fabricated using near-field scanning optical nanolithography (NSOL) are investigated. The nanopatterns could be used as nanomasks for pattern transfer on a silicon wafer. In the NSOL process, uniform patterning with high reproducibility is essential for reliable transfer of the mask patterns on a silicon substrate. Using an aperture type cantilever nanoprobe operated at contact mode and a positive photoresist, various nanopatterns are produced on thin photoresist layer coated on the silicon substrate. The size and shape variations of thereby produced patterns are investigated using atomic force microscope to determine their uniformity and reproducibility. It is demonstrated that the NSOL-produced photo-resist nanomasks can be successfully applied for silicon pattern transfer by fabricating a silicon nanochannel array. PMID:17252829

Kwon, Sangjin; Jeong, Youngmo; Jeong, Sungho

2006-11-01

119

Impact of (111)-Oriented SrRuO3/Pt Tailored Electrode for Highly Reproducible Preparation of Metal Organic Chemical Vapour Deposited Pb(Zr,Ti)O3 Films for High Density Ferroelectric Random Access Memory Applications  

NASA Astrophysics Data System (ADS)

In the present paper we report a comparative study of the structural, morphologic, and electric properties of Pb(Zr,Ti)O3 films, deposited by pulsed metal-organic chemical vapour deposition (MOCVD), on different (111)-oriented bottom-electrode stacks (SrRuO3/Pt, Pt, and Ir substrates). The Pb input ratio in the MOCVD chamber was systematically modified for each deposition run to obtain PZT films with various compositions within the Pb process window. Our results clearly demonstrate that only PZT films deposited on SrRuO3 show high quality and reproducible properties throughout the process window, i.e., high (111) texture, low roughness (<5 nm), high Pr (˜40 ?C/cm2), low Vc (<1 V), as well as a relatively low leakage current (˜ 10-5 A/cm2 at 1.5 V). This study provides further evidence that SrRuO3/Pt substrates are good candidates for integration in next-generation high-density ferroelectric random access memories (FeRAM).

Menou, Nicolas; Kuwabara, Hiroki; Funakubo, Hiroshi

2007-04-01

120

Lentiviral vectors containing an enhancer-less ubiquitously acting chromatin opening element (UCOE) provide highly reproducible and stable transgene expression in hematopoietic cells  

Microsoft Academic Search

Ubiquitously acting chromatin opening elements (UCOEs) consist of methylation- free CpG islands encompassing dual diver- gently transcribed promoters of house- keeping genes that have been shown to confer resistance to transcriptional si- lencing and to produce consistent and stable transgene expression in tissue culture systems. To develop improved strat- egies for hematopoietic cell gene therapy, we have assessed the potential

Fang Zhang; Susannah I. Thornhill; Steven J. Howe; Meera Ulaganathan; Axel Schambach; Joanna Sinclair; Christine Kinnon; H. Bobby Gaspar; Michael Antoniou; Adrian J. Thrasher; R. S. Larson; B. P. Alter; G. M. Baerlocher; S. A. Savage; S. J. Chanock; B. B. Weksler; J. P. Willner; J. A. Peters; N. Giri; P. M. Lansdorp; F. Zhang

2007-01-01

121

WHY DO MOST TROPICAL ANIMALS REPRODUCE SEASONALLY? TESTING HYPOTHESES ON AN AUSTRALIAN SNAKE  

Microsoft Academic Search

Most species reproduce seasonally, even in the tropics where activity occurs year-round. Squamate reptiles provide ideal model organisms to clarify the ultimate (adap- tive) reasons for the restriction of reproduction to specific times of year. Females of almost all temperate-zone reptile species produce their eggs or offspring in the warmest time of the year, thereby synchronizing embryogenesis with high ambient

G. P. Brown; R. Shine

2006-01-01

122

Rotary head type reproducing apparatus  

DOEpatents

In an apparatus of the kind arranged to reproduce, with a plurality of rotary heads, an information signal from a record bearing medium having many recording tracks which are parallel to each other with the information signal recorded therein and with a plurality of different pilot signals of different frequencies also recorded one by one, one in each of the recording tracks, a plurality of different reference signals of different frequencies are simultaneously generated. A tracking error is detected by using the different reference signals together with the pilot signals which are included in signals reproduced from the plurality of rotary heads.

Takayama, Nobutoshi (Kanagawa, JP); Edakubo, Hiroo (Tokyo, JP); Kozuki, Susumu (Tokyo, JP); Takei, Masahiro (Kanagawa, JP); Nagasawa, Kenichi (Kanagawa, JP)

1986-01-01

123

Comparability and reproducibility of biomedical data  

PubMed Central

With the development of novel assay technologies, biomedical experiments and analyses have gone through substantial evolution. Today, a typical experiment can simultaneously measure hundreds to thousands of individual features (e.g. genes) in dozens of biological conditions, resulting in gigabytes of data that need to be processed and analyzed. Because of the multiple steps involved in the data generation and analysis and the lack of details provided, it can be difficult for independent researchers to try to reproduce a published study. With the recent outrage following the halt of a cancer clinical trial due to the lack of reproducibility of the published study, researchers are now facing heavy pressure to ensure that their results are reproducible. Despite the global demand, too many published studies remain non-reproducible mainly due to the lack of availability of experimental protocol, data and/or computer code. Scientific discovery is an iterative process, where a published study generates new knowledge and data, resulting in new follow-up studies or clinical trials based on these results. As such, it is important for the results of a study to be quickly confirmed or discarded to avoid wasting time and money on novel projects. The availability of high-quality, reproducible data will also lead to more powerful analyses (or meta-analyses) where multiple data sets are combined to generate new knowledge. In this article, we review some of the recent developments regarding biomedical reproducibility and comparability and discuss some of the areas where the overall field could be improved.

Huang, Yunda; Gottardo, Raphael

2013-01-01

124

Comparability and reproducibility of biomedical data.  

PubMed

With the development of novel assay technologies, biomedical experiments and analyses have gone through substantial evolution. Today, a typical experiment can simultaneously measure hundreds to thousands of individual features (e.g. genes) in dozens of biological conditions, resulting in gigabytes of data that need to be processed and analyzed. Because of the multiple steps involved in the data generation and analysis and the lack of details provided, it can be difficult for independent researchers to try to reproduce a published study. With the recent outrage following the halt of a cancer clinical trial due to the lack of reproducibility of the published study, researchers are now facing heavy pressure to ensure that their results are reproducible. Despite the global demand, too many published studies remain non-reproducible mainly due to the lack of availability of experimental protocol, data and/or computer code. Scientific discovery is an iterative process, where a published study generates new knowledge and data, resulting in new follow-up studies or clinical trials based on these results. As such, it is important for the results of a study to be quickly confirmed or discarded to avoid wasting time and money on novel projects. The availability of high-quality, reproducible data will also lead to more powerful analyses (or meta-analyses) where multiple data sets are combined to generate new knowledge. In this article, we review some of the recent developments regarding biomedical reproducibility and comparability and discuss some of the areas where the overall field could be improved. PMID:23193203

Huang, Yunda; Gottardo, Raphael

2013-07-01

125

Reproducibility of ambulatory blood pressure load.  

PubMed

Twenty-two hypertensive patients were monitored during two separate drug-free occasions with a Del Mar Avionics ambulatory device. Blood pressure loads (percentage of systolic and diastolic readings more than 140 and 90 mmHg, respectively) and mean BP were measured both to determine their reproducibility and to examine how they correlate with each other. The systolic and diastolic mean awake BPs for day 1 and day 2 were 140/93 mmHg and 140/91 mmHg, respectively, and BP loads were 45%/55% and 43%/54%. Moreover, mean BP loads correlated highly (r = 0.93) with mean BP values taken on the same day. Both ambulatory mean SBP and BP load were highly reproducible (r = 0.87 and 0.80, respectively, during the awake hours), and mean DBP and load were fairly reproducible (r = 0.59 and 0.39, respectively, during the awake hours). Clinically, however, both were consistent from day 1 to day 2. Mean and individual standard deviations also were reproducible for both systolic and diastolic pressures and loads. PMID:2096203

Zachariah, P K; Sheps, S G; Bailey, K R; Wiltgen, C M; Moore, A G

1990-12-01

126

Phase distortions of attosecond pulses produced by resonance-enhanced high harmonic generation  

NASA Astrophysics Data System (ADS)

Resonant enhancement of high harmonic generation can be obtained in plasmas containing ions with strong radiative transitions resonant with harmonic orders. The mechanism for this enhancement is still debated. We perform the first temporal characterization of the attosecond emission from a tin plasma under near-resonant conditions for two different resonance detunings. We show that the resonance considerably changes the relative phase of neighboring harmonics. For very small detunings, their phase locking may even be lost, evidencing strong phase distortions in the emission process and a modified attosecond structure. These features are well reproduced by our simulations, allowing their interpretation in terms of the phase of the recombination dipole moment.

Haessler, S.; Strelkov, V.; Elouga Bom, L. B.; Khokhlova, M.; Gobert, O.; Hergott, J.-F.; Lepetit, F.; Perdrix, M.; Ozaki, T.; Salières, P.

2013-01-01

127

Oxygen-sensitive phosphorescent nanomaterials produced from high-density polyethylene films by local solvent-crazing.  

PubMed

Discrete solid-state phosphorescent oxygen sensors produced by local solvent-crazing of high density polyethylene films are described. The simple spotting of dye solution followed by tensile drawing of the polymer substrate provides uniform nanostructures with good spatial control, effective encapsulation of dye molecules, and quenchability by O2. The dye-polymer composite sensors prepared using toluene as a solvent and stabilized by annealing at high temperature, show moderate optical signals, near-optimal sensitivity to O2 (RSD at 21 KPa 1.9%), and reproducible phosphorescence lifetime readings. Calibration experiments performed over 0-25 kPa O2 and 10-30 °C temperatures ranges reveal linear Stern-Volmer plots and temperature dependences and minimal effect of humidity on sensor calibration. The high degree of lateral and in-depth homogeneity of these O2-sensitive materials was confirmed by high-resolution atomic force and wide-field optical microscopy, including 2D and 3D phosphorescence lifetime imaging. PMID:24422456

Toncelli, Claudio; Arzhakova, Olga V; Dolgova, Alla; Volynskii, Aleksandr L; Bakeev, Nikolai F; Kerry, Joe P; Papkovsky, Dmitri B

2014-02-01

128

Reproducibility of striatal and thalamic dopamine D2 receptor binding using [11C]raclopride with high-resolution positron emission tomography  

Microsoft Academic Search

Positron emission tomography (PET) imaging of small striatal brain structures such as the ventral striatum (VST) has been hampered by low spatial resolution causing partial-volume effects. The high-resolution research tomograph (HRRT) is a brain-dedicated PET scanner that has considerably better spatial resolution than its predecessors. However, its superior spatial resolution is associated with a lower signal-to-noise ratio. We evaluated the

Kati Alakurtti; Sargo Aalto; Jarkko J Johansson; Kjell Någren; Terhi Tuokkola; Vesa Oikonen; Matti Laine; Juha O Rinne

2011-01-01

129

Interaction of high Mach-number shocks in laser-produced plasmas  

NASA Astrophysics Data System (ADS)

We report the laboratory experiment for high Mach-number collisionless shock formation and for studying the interaction of them. These shocks are formed in high-velocity counterstreaming plasmas produced by ablating a double-foil plastic target with a high-power laser. The laser-produced plasmas are diagnosed with space and time-resolved optical pyrometry and shadowgraphy. Multiple shocks are formed and interact with each other, resulting in the increase of plasma temperature and density.

Morita, T.; Sakawa, Y.; Kuramitsu, Y.; Dono, S.; Tanji, H.; Aoki, H.; Ide, T.; Nishio, K.; Gregory, C. D.; Waugh, J. N.; Woolsey, N.; Diziére, A.; Koenig, M.; Ide, H.; Tsubouchi, K.; Takabe, H.

2013-03-01

130

Reproducibility of Magnetic Avalanches in a Ferromagnet  

NASA Astrophysics Data System (ADS)

We have been studying the Barkhausen effect (magnetic avalanches produced by the motion of domain walls) in an unsual Fe-Ni-Co ferromagnet that allows us to repeatedly prepare the magnet in a particular disordered domain configuration. We have found that the avalanche sequence produced as the system is forced out of this configuration by an applied magnetic field has features that are almost exactly reproducible (events that occur at the same field on every cycle) intermingled with events that show no apparent reproducibility.(J.S. Urbach, R.C. Madison, J.T. Markert, Phys. Rev. Lett., 12/11/95.) Averaging the avalanche activity over many cycles produces a fingerprint, analogous to effects observed in mesoscopic samples, that reflects the quenched disorder in the material. The fingerprint is not strongly temperature or driving-rate dependent, indicating that the variability is a consequence of dynamical effects. We also have found that the slope of the cycle-averaged magnetization, d/dH, is correlated with the cycle-to-cycle variations in magnetization, <(?M)^2>, suggesting an analogy with the fluctuation-dissipation relationship of equilibrium thermodynamics.

Urbach, J. S.; Madison, R. C.; Markert, J. T.

1996-03-01

131

Sickle cell disease in areas of immigration of high-risk populations: a low cost and reproducible method of screening in northern Italy  

PubMed Central

Background From 2005 to 2010, we observed a 10-fold increase of newly diagnosed sickle cell disease in children in the province of Modena (northern Italy). The median age at diagnosis was 24 months. Since these children are too old for optimal disease management, earlier detection of the disease is needed for prophylaxis and comprehensive care before the occurrence of clinical manifestations. Materials and methods In each Maternity Unit of the province of Modena, blood samples are collected daily for assessment of haemolytic disease of the newborn. We designed a selective, low-cost haemoglobin screening for sickle cell disease in high-risk immigrants. We enrolled 469 mothers from sub-Saharan countries and their neonates for a primary screening of peripheral blood haemoglobin variants using high-performance liquid chromatography. Results Of the 469 women approached, 330 (70.36%) agreed to undergo the test. Ninety-two (27.88%) were carriers of variant haemoglobin, 48 newborns (51%) of these carriers had the carrier trait and 9 (9.6%) were affected (haemoglobin SC compound heterozigote - HbSC, haemoglobin S homozygote - HbSS). Discussion These results support the feasibility and usefulness of a selective screening for the detection of haemoglobin variants in high-risk subjects in an area in which sickle cells disease is not endogenous. We achieved the goal of detecting subjects with carrier trait/disease in order to implement preventive measures that reduce the clinical manifestations of sickle cell disease. We are, however, aware that it will be necessary to extend this screening to the overall population in the near future.

Venturelli, Donatella; Lodi, Mariachiara; Palazzi, Giovanni; Bergonzini, Giuliano; Doretto, Giada; Zini, Annalisa; Monica, Cellini; Cano, M. Carmen; Ilaria, Mariotti; Montagnani, Giuliano; Paolucci, Paolo

2014-01-01

132

Well-organized raspberry-like Ag@Cu bimetal nanoparticles for highly reliable and reproducible surface-enhanced Raman scattering  

NASA Astrophysics Data System (ADS)

Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy (SERS) with a large enhancement factor (EF). A highly reliable SERS effect was demonstrated using Rhodamine 6G (R6G) molecules and a thin film of gadolinium doped ceria.Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy (SERS) with a large enhancement factor (EF). A highly reliable SERS effect was demonstrated using Rhodamine 6G (R6G) molecules and a thin film of gadolinium doped ceria. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03363e

Lee, Jung-Pil; Chen, Dongchang; Li, Xiaxi; Yoo, Seungmin; Bottomley, Lawrence A.; El-Sayed, Mostafa A.; Park, Soojin; Liu, Meilin

2013-11-01

133

Well-organized raspberry-like Ag@Cu bimetal nanoparticles for highly reliable and reproducible surface-enhanced Raman scattering.  

PubMed

Surface-enhanced Raman scattering (SERS) is ideally suited for probing and mapping surface species and incipient phases on fuel cell electrodes because of its high sensitivity and surface-selectivity, potentially offering insights into the mechanisms of chemical and energy transformation processes. In particular, bimetal nanostructures of coinage metals (Au, Ag, and Cu) have attracted much attention as SERS-active agents due to their distinctive electromagnetic field enhancements originated from surface plasmon resonance. Here we report excellent SERS-active, raspberry-like nanostructures composed of a silver (Ag) nanoparticle core decorated with smaller copper (Cu) nanoparticles, which displayed enhanced and broadened UV-Vis absorption spectra. These unique Ag@Cu raspberry nanostructures enable us to use blue, green, and red light as the excitation laser source for surface-enhanced Raman spectroscopy (SERS) with a large enhancement factor (EF). A highly reliable SERS effect was demonstrated using Rhodamine 6G (R6G) molecules and a thin film of gadolinium doped ceria. PMID:24126702

Lee, Jung-Pil; Chen, Dongchang; Li, Xiaxi; Yoo, Seungmin; Bottomley, Lawrence A; El-Sayed, Mostafa A; Park, Soojin; Liu, Meilin

2013-12-01

134

Derivation of High Enterotoxin B-Producing Mutants of Staphylococcus aureus from the Parent Strains  

PubMed Central

Certain pH-sensitive (membrane) mutants of Staphylococcus aureus, strains 14458 and 778, produce significantly more type-B enterotoxin (SEB) than the parent type. Some carbohydrate mutants (car) from these parent strains also are superior to the parent in SEB formation. By isolating car mutants from high-SEB-producing membrane mutants, it is possible to derive a double mutant producing from six to 50 times as much SEB as the parent type. Inversion of the sequence by isolating pH-sensitive mutants from car mutants does not yield clones with strikingly higher SEB production than the parent strain. The successful isolation sequence (pH-sensitive mutant first and car mutants derived from it) is relatively simple and virtually assures detection of a truly high-SEB-producing clone. The total number of clones whose direct assay for SEB formation is necessary for detection of a high-producing mutant is on the order of 50 to 60.

Altenbern, Robert A.

1975-01-01

135

Desalination and reuse of high-salinity shale gas produced water: drivers, technologies, and future directions.  

PubMed

In the rapidly developing shale gas industry, managing produced water is a major challenge for maintaining the profitability of shale gas extraction while protecting public health and the environment. We review the current state of practice for produced water management across the United States and discuss the interrelated regulatory, infrastructure, and economic drivers for produced water reuse. Within this framework, we examine the Marcellus shale play, a region in the eastern United States where produced water is currently reused without desalination. In the Marcellus region, and in other shale plays worldwide with similar constraints, contraction of current reuse opportunities within the shale gas industry and growing restrictions on produced water disposal will provide strong incentives for produced water desalination for reuse outside the industry. The most challenging scenarios for the selection of desalination for reuse over other management strategies will be those involving high-salinity produced water, which must be desalinated with thermal separation processes. We explore desalination technologies for treatment of high-salinity shale gas produced water, and we critically review mechanical vapor compression (MVC), membrane distillation (MD), and forward osmosis (FO) as the technologies best suited for desalination of high-salinity produced water for reuse outside the shale gas industry. The advantages and challenges of applying MVC, MD, and FO technologies to produced water desalination are discussed, and directions for future research and development are identified. We find that desalination for reuse of produced water is technically feasible and can be economically relevant. However, because produced water management is primarily an economic decision, expanding desalination for reuse is dependent on process and material improvements to reduce capital and operating costs. PMID:23885720

Shaffer, Devin L; Arias Chavez, Laura H; Ben-Sasson, Moshe; Romero-Vargas Castrillón, Santiago; Yip, Ngai Yin; Elimelech, Menachem

2013-09-01

136

Epoxy Resin Laminates with High Heat Resistance Based on a Curing System Producing the Oxazolidone Ring.  

National Technical Information Service (NTIS)

New epoxy resin laminates were developed, which showed high heat resistance and which contained oxazolidone rings produced by reaction of epoxy and isocyanate groups. These laminates were prepared by using a prepolymer stable at room temperature which was...

S. Yamaoka M. Mizuno

1986-01-01

137

Chemical composition of smoke produced by high-frequency electrosurgery in a closed gaseous environment  

Microsoft Academic Search

Background: High-frequency (HF) electrocoagulation and cutting procedures produce smoke by high-temperature pyrolysis of tissues. As\\u000a distinct from the experience of conventional surgery, electrosurgical smoke is produced in a closed gaseous environment during\\u000a laparoscopic operations. As a result, toxic chemicals may be absorbed into the circulation. The effects of this absorption\\u000a are not known. Furthermore, the chemical composition of electrosurgical smoke

C. Hensman; D. Baty; R. G. Willis; A. Cuschieri

1998-01-01

138

Reproducibility of 3D chromatin configuration reconstructions.  

PubMed

It is widely recognized that the three-dimensional (3D) architecture of eukaryotic chromatin plays an important role in processes such as gene regulation and cancer-driving gene fusions. Observing or inferring this 3D structure at even modest resolutions had been problematic, since genomes are highly condensed and traditional assays are coarse. However, recently devised high-throughput molecular techniques have changed this situation. Notably, the development of a suite of chromatin conformation capture (CCC) assays has enabled elicitation of contacts-spatially close chromosomal loci-which have provided insights into chromatin architecture. Most analysis of CCC data has focused on the contact level, with less effort directed toward obtaining 3D reconstructions and evaluating the accuracy and reproducibility thereof. While questions of accuracy must be addressed experimentally, questions of reproducibility can be addressed statistically-the purpose of this paper. We use a constrained optimization technique to reconstruct chromatin configurations for a number of closely related yeast datasets and assess reproducibility using four metrics that measure the distance between 3D configurations. The first of these, Procrustes fitting, measures configuration closeness after applying reflection, rotation, translation, and scaling-based alignment of the structures. The others base comparisons on the within-configuration inter-point distance matrix. Inferential results for these metrics rely on suitable permutation approaches. Results indicate that distance matrix-based approaches are preferable to Procrustes analysis, not because of the metrics per se but rather on account of the ability to customize permutation schemes to handle within-chromosome contiguity. It has recently been emphasized that the use of constrained optimization approaches to 3D architecture reconstruction are prone to being trapped in local minima. Our methods of reproducibility assessment provide a means for comparing 3D reconstruction solutions so that we can discern between local and global optima by contrasting solutions under perturbed inputs. PMID:24519450

Segal, Mark R; Xiong, Hao; Capurso, Daniel; Vazquez, Mariel; Arsuaga, Javier

2014-07-01

139

Within-patient reproducibility of the aldosterone: renin ratio in primary aldosteronism.  

PubMed

The plasma aldosterone concentration:renin ratio (ARR) is widely used for the screening of primary aldosteronism, but its reproducibility is unknown. We, therefore, investigated the within-patient reproducibility of the ARR in a prospective multicenter study of consecutive hypertensive patients referred to specialized centers for hypertension in Italy. After the patients were carefully prepared from the pharmacological standpoint, the ARR was determined at baseline in 1136 patients and repeated after, on average, 4 weeks in the patients who had initially an ARR > or =40 and in 1 of every 4 of those with an ARR <40. The reproducibility of the ARR was assessed with Passing and Bablok and Deming regression, coefficient of reproducibility, and Bland-Altman and Mountain plots. Within-patient ARR comparison was available in 268 patients, of whom 49 had an aldosterone-producing adenoma, on the basis of the "4-corner criteria." The ARR showed a highly significant within-patient correlation (r=0.69; P<0.0001) and reproducibility. Bland-Altman plot showed no proportional, magnitude-related, or absolute systematic error between the ARR; moreover, only 7% of the values, for example, slightly more than what could be expected by chance, fell out of the 95% CI for the between-test difference. The accuracy of each ARR for pinpointing aldosterone-producing adenoma patients was approximately 80%. Thus, although it was performed under different conditions in a multicenter study, the ARR showed a good within-patient reproducibility. Hence, contrary to previously claimed poor reproducibility of the ARR, these data support its use for the screening of primary aldosteronism. PMID:19933925

Rossi, Gian Paolo; Seccia, Teresa Maria; Palumbo, Gaetana; Belfiore, Anna; Bernini, Giampaolo; Caridi, Graziella; Desideri, Giovambattista; Fabris, Bruno; Ferri, Claudio; Giacchetti, Gilberta; Letizia, Claudio; Maccario, Mauro; Mallamaci, Francesca; Mannelli, Massimo; Patalano, Anna; Rizzoni, Damiano; Rossi, Ermanno; Pessina, Achille Cesare; Mantero, Franco

2010-01-01

140

Quantizations from reproducing kernel spaces  

SciTech Connect

The purpose of this work is to explore the existence and properties of reproducing kernel Hilbert subspaces of L{sup 2}(C,d{sup 2}z/?) based on subsets of complex Hermite polynomials. The resulting coherent states (CS) form a family depending on a nonnegative parameter s. We examine some interesting issues, mainly related to CS quantization, like the existence of the usual harmonic oscillator spectrum despite the absence of canonical commutation rules. The question of mathematical and physical equivalences between the s-dependent quantizations is also considered. -- Highlights: ? We discuss in detail an interesting decomposition of L{sup 2}, in terms of ladder operators. ? We consider coherent states on this structure and we use them for quantization. ? We show how this structure is related with non hermitian quantum mechanics. ? We consider the relation between different schemes of quantizations.

Twareque Ali, S., E-mail: stali@mathstat.concordia.ca [Department of Mathematics and Statistics, Concordia University, Montréal, Québec, Canada H3G 1M8 (Canada); Bagarello, F., E-mail: fabio.bagarello@unipa.it [Dieetcam, Facoltà di Ingegneria, Università di Palermo, I-90128 Palermo (Italy); Pierre Gazeau, Jean, E-mail: gazeau@apc.univ-paris7.fr [Laboratoire APC, Université Paris 7-Denis Diderot, 10, rue A. Domon et L. Duquet, 75205 Paris Cedex 13 (France)

2013-05-15

141

Reproducibility of magnetic resonance perfusion imaging.  

PubMed

Dynamic MR biomarkers (T2*-weighted or susceptibility-based and T1-weighted or relaxivity-enhanced) have been applied to assess tumor perfusion and its response to therapies. A significant challenge in the development of reliable biomarkers is a rigorous assessment and optimization of reproducibility. The purpose of this study was to determine the measurement reproducibility of T1-weighted dynamic contrast-enhanced (DCE)-MRI and T2*-weighted dynamic susceptibility contrast (DSC)-MRI with two contrast agents (CA) of different molecular weight (MW): gadopentetate (Gd-DTPA, 0.5 kDa) and Gadomelitol (P792, 6.5 kDa). Each contrast agent was tested with eight mice that had subcutaneous MDA-MB-231 breast xenograft tumors. Each mouse was imaged with a combined DSC-DCE protocol three times within one week to achieve measures of reproducibility. DSC-MRI results were evaluated with a contrast to noise ratio (CNR) efficiency threshold. There was a clear signal drop (>95% probability threshold) in the DSC of normal tissue, while signal changes were minimal or non-existent (<95% probability threshold) in tumors. Mean within-subject coefficient of variation (wCV) of relative blood volume (rBV) in normal tissue was 11.78% for Gd-DTPA and 6.64% for P792. The intra-class correlation coefficient (ICC) of rBV in normal tissue was 0.940 for Gd-DTPA and 0.978 for P792. The inter-subject correlation coefficient was 0.092. Calculated K(trans) from DCE-MRI showed comparable reproducibility (mean wCV, 5.13% for Gd-DTPA, 8.06% for P792). ICC of K(trans) showed high intra-subject reproducibility (ICC = 0.999/0.995) and inter-subject heterogeneity (ICC = 0.774). Histograms of K(trans) distributions for three measurements had high degrees of overlap (sum of difference of the normalized histograms <0.01). These results represent homogeneous intra-subject measurement and heterogeneous inter-subject character of biological population, suggesting that perfusion MRI could be an imaging biomarker to monitor or predict response of disease. PMID:24587040

Zhang, Xiaomeng; Pagel, Mark D; Baker, Amanda F; Gillies, Robert J

2014-01-01

142

Evaluation of guidewire path reproducibility.  

PubMed

The number of minimally invasive vascular interventions is increasing. In these interventions, a variety of devices are directed to and placed at the site of intervention. The device used in almost all of these interventions is the guidewire, acting as a monorail for all devices which are delivered to the intervention site. However, even with the guidewire in place, clinicians still experience difficulties during the interventions. As a first step toward understanding these difficulties and facilitating guidewire and device guidance, we have investigated the reproducibility of the final paths of the guidewire in vessel phantom models on different factors: user, materials and geometry. Three vessel phantoms (vessel diameters approximately 4 mm) were constructed having tortuousity similar to the internal carotid artery from silicon tubing and encased in Sylgard elastomer. Several trained users repeatedly passed two guidewires of different flexibility through the phantoms under pulsatile flow conditions. After the guidewire had been placed, rotational c-arm image sequences were acquired (9 in. II mode, 0.185 mm pixel size), and the phantom and guidewire were reconstructed (512(3), 0.288 mm voxel size). The reconstructed volumes were aligned. The centerlines of the guidewire and the phantom vessel were then determined using region-growing techniques. Guidewire paths appear similar across users but not across materials. The average root mean square difference of the repeated placement was 0.17 +/- 0.02 mm (plastic-coated guidewire), 0.73 +/- 0.55 mm (steel guidewire) and 1.15 +/- 0.65 mm (steel versus plastic-coated). For a given guidewire, these results indicate that the guidewire path is relatively reproducible in shape and position. PMID:18561663

Schafer, Sebastian; Hoffmann, Kenneth R; Noël, Peter B; Ionita, Ciprian N; Dmochowski, Jacek

2008-05-01

143

Directional solidification of alloys as a means of producing structures ensuring high wear resistance  

Microsoft Academic Search

1.A description is given of a new process for the preparation of surface layers of high wear resistance, and its effectiveness is demonstrated.2.A high resistance to rupture under the action of friction is achieved by producing in the surface layer ordered fibrous structures containing hardening phases. This is achieved by heating the surface of coated parts to incipient melting temperatures

L. F. Kolesnichenko; V. V. Polotai

1970-01-01

144

Measurements of spatially resolved high resolution spectra of laser-produced plasmas. FY 83 annual report  

Microsoft Academic Search

A high resolution grazing incidence spectrograph, provided by the Naval Research Laboratory and the Goddard Space Flight Center, has been installed on the Omega laser facility of the Laboratory for Laser Energetics (LLE) at the University of Rochester. This 3 meter instrument, with a 1200 lines\\/mm grating blazed at 2° 35', has produced extremely high quality spectra in the wavelength

1984-01-01

145

Some new schemes for producing high-accuracy elliptical X-ray mirrors by elastic bending  

SciTech Connect

Although x-ray micro-foci can be produced by a variety of diffractive methods, grazing incidence mirrors are the only route to an achromatic focus. In this paper we describe our efforts to produce elliptically shaped mirrors with the very high figure accuracy necessary for producing a micro-focus. The motivation for this work is provided by the need to produce achromatic foci for a range of applications ranging from tunable micro-focus x-ray photoelectron spectroscopy ({mu}-XPS) at soft x-ray energies to micro-focus white beam x-ray diffraction ({mu}-XRD) at hard x-ray energies. We describe the methodology of beam bending, a practical example of a system we have produced for {mu}-XRD, and results demonstrating the production of a surface with micro-radian figure accuracy.

Padmore, H.A.; Howells, M.R.; Irick, S.; Renner, T.; Sandler, R. [Lawrence Berkeley National Lab., CA (US); Koo, Y.-M. [Pohang Univ. of Science and Technology (Korea, Republic of)

1996-08-01

146

Fatal Syndrome in Mice Engrafted with Cells Producing High Levels of the Leukemia Inhibitory Factor  

Microsoft Academic Search

Cells of the murine hemopoietic cell line FDC-P1 were multiply infected with a retroviral construct containing cDNA encoding the leukemia inhibitory factor (LIF) to produce cells secreting high levels of LIF. Injection of these cells to unirradiated or irradiated syngeneic DBA\\/2 mice resulted in animals engrafted with LIF-producing cells in the marrow, spleen, and lymph nodes and with elevated serum

D. Metcalf; D. P. Gearing

1989-01-01

147

Assessment of high and low enterotoxin A producing Staphylococcus aureus strains on pork sausage.  

PubMed

Three Staphylococcus aureus strains representing different alleles of the Siphoviridae prophage-encoded enterotoxin A (SEA) gene, including two high-SEA-producing strains and one low-SEA-producing strain were studied to investigate sea expression and SEA formation on a frankfurter type of sausage. The effect of lactic acid, an antimicrobial compound used as a preservative in food, was also investigated on the same product. All three strains were grown on pork sausages at 15°C for 14days in the presence or absence of lactic acid (1 or 2% v/v). Growth, sea mRNA expression and SEA formation were regularly monitored and compared between non-treated and treated sausages. For all experiments performed, the extracellular SEA formation significantly differed between the high- and low-SEA-producing strains, although growth and viability were overall the same. For the low producer (Sa51), the accumulated amount of extracellular SEA formed after 14days was close to the detection limit (less than 1ng/g) in all conditions; while Sa21 and Sa17, the two high-producing strains, formed 250±25.37ng/g and 750±82.65ng/g in non-treated sausage and 150±75.75ng/g and 300±83.89ng/g when treated with 1% lactic acid, respectively, after 14days. Sausages treated with 2% lactic acid followed the same pattern as above, but with an extended lag phase to 4days and reduced levels of enterotoxin formed for all strains. The difference in the level of SEA between the two high-producing strains is most likely due to the different clonal lineages of the sea-encoded Siphoviridae phages where induction of the prophage potentially could be the reason for higher production of SEA in one of the lines. Furthermore, a prolonged expression of sea gene in the two high-producing strains was observed during the entire incubation period, while the sea expression was under the detection limit in the low-producing strain. This study indicates that the high-SEA-producing strains, especially the strains with the putative capacity of prophage induction, could be more relevant in food safety aspects than low-producing type of strains on pork sausage. PMID:24859189

Zeaki, Nikoleta; Cao, Rong; Skandamis, Panagiotis N; Rådström, Peter; Schelin, Jenny

2014-07-16

148

A visual method for direct selection of high-producing Pichia pastoris clones  

PubMed Central

Background The methylotrophic yeast, Pichia pastoris, offers the possibility to generate a high amount of recombinant proteins in a fast and easy way to use expression system. Being a single-celled microorganism, P. pastoris is easy to manipulate and grows rapidly on inexpensive media at high cell densities. A simple and direct method for the selection of high-producing clones can dramatically enhance the whole production process along with significant decrease in production costs. Results A visual method for rapid selection of high-producing clones based on mannanase reporter system was developed. The study explained that it was possible to use mannanase activity as a measure of the expression level of the protein of interest. High-producing target protein clones were directly selected based on the size of hydrolysis holes in the selected plate. As an example, the target gene (9elp-hal18) was expressed and purified in Pichia pastoris using this technology. Conclusions A novel methodology is proposed for obtaining the high-producing clones of proteins of interest, based on the mannanase reporter system. This system may be adapted to other microorganisms, such as Saccharomyces cerevisiae for the selection of clones.

2011-01-01

149

Insulator coating for high temperature alloys method for producing insulator coating for high temperature alloys  

DOEpatents

A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface. Lastly, the invention provides an electrically insulative coating comprising an underlying structural substrate coated with an oxide or nitride compound. 2 figs.

Park, J.H.

1998-06-23

150

Properties of a high-torularhodin-producing mutant of Rhodotorula glutinis cultivated under oxidative stress.  

PubMed

To characterize the properties of torularhodin, which is one of the carotenoid pigments produced by the yeast Rhodotorula sp., a mutant which produces large amounts of torularhodin was constructed and its tolerance against oxidative stress was investigated. The mutant we obtained was capable of producing large amounts of torularhodin in response to irradiation with blue light. The mutant, incubated under irradiation with white light that resulted in an increased production of torularhodin, exhibited resistance to growth inhibition induced by the addition of methylene blue as the generator of singlet oxygen. Leakage of lactate dehydrogenase to the growth medium from the mutant was not increased as compared to that from a parent strain and a high-beta-carotene-producing mutant. These results suggest that an increase in the production of torularhodin reduces the susceptibility to injury induced by an active oxygen species. PMID:16232728

Sakaki, H; Nakanishi, T; Satonaka, K; Miki, W; Fujita, T; Komemushi, S

2000-01-01

151

High-strength, creep-resistant molybdenum alloy and process for producing the same  

DOEpatents

A wet-doping process for producing an oxide-dispersion strengthened (ODS), creep-resistant molybdenum alloy is disclosed. The alloy is made by adding nitrate or acetate salts of lanthanum, cerium, thorium, or yttrium to molybdenum oxide to produce a slurry, heating the slurry in a hydrogen atmosphere to produce a powder, mixing and cold isostatically pressing the powder, sintering in a hydrogen atmosphere, and thermomechanically processing (swaging, extruding, cold drawing) the product. The ODS molybdenum alloy produced by the process contains 2-4% by volume (.about.1-4% by weight) of an oxide of lanthanum, cerium, thorium, or yttrium. The alloy has high strength and improved creep-resistance at temperatures greater than 0.55T.sub.m of molybdenum.

Bianco, Robert (Finleyville, PA) [Finleyville, PA; Buckman, Jr., R. William (Pittsburgh, PA); Geller, Clint B. (Pittsburgh, PA) [Pittsburgh, PA

1999-01-01

152

High-strength, creep-resistant molybdenum alloy and process for producing the same  

DOEpatents

A wet-doping process for producing an oxide-dispersion strengthened (ODS), creep-resistant molybdenum alloy is disclosed. The alloy is made by adding nitrate or acetate salts of lanthanum, cerium, thorium, or yttrium to molybdenum oxide to produce a slurry, heating the slurry in a hydrogen atmosphere to produce a powder, mixing and cold isostatically pressing the powder, sintering in a hydrogen atmosphere, and thermomechanically processing (swaging, extruding, cold drawing) the product. The ODS molybdenum alloy produced by the process contains 2--4% by volume (ca. 1--4% by weight) of an oxide of lanthanum, cerium, thorium, or yttrium. The alloy has high strength and improved creep-resistance at temperatures greater than 0.55T{sub m} of molybdenum. 10 figs.

Bianco, R.; Buckman, R.W. Jr.; Geller, C.B.

1999-02-09

153

High strength-high conductivity Cu-Fe composites produced by powder compaction/mechanical reduction  

DOEpatents

A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an ''in-situ'' Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite. 5 figures.

Verhoeven, J.D.; Spitzig, W.A.; Gibson, E.D.; Anderson, I.E.

1991-08-27

154

High strength-high conductivity Cu--Fe composites produced by powder compaction/mechanical reduction  

DOEpatents

A particulate mixture of Cu and Fe is compacted and mechanically reduced to form an "in-situ" Cu-Fe composite having high strength and high conductivity. Compaction and mechanical reduction of the particulate mixture are carried out at a temperature and time at temperature selected to avoid dissolution of Fe into the Cu matrix particulates to a harmful extent that substantially degrades the conductivity of the Cu-Fe composite.

Verhoeven, John D. (Ames, IA); Spitzig, William A. (Ames, IA); Gibson, Edwin D. (Ames, IA); Anderson, Iver E. (Ames, IA)

1991-08-27

155

Colour changes produced in natural brown diamonds by high-pressure, high-temperature treatment  

Microsoft Academic Search

Absorption and luminescence spectra have been measured for natural brown diamonds before and after high-pressure, high-temperature (HPHT) treatment at 1700–1800°C, and after HPHT treatment at 2025°C. The reduction of the brown colour noted in diamonds with low nitrogen concentration is attributed to the annealing of plastic deformation. In nitrogen-containing diamonds the vacancies released during this annealing are trapped to form

Alan T Collins; Hisao Kanda; Hiroshi Kitawaki

2000-01-01

156

Cloning to reproduce desired genotypes  

Microsoft Academic Search

Cloned sheep, cattle, goats, pigs and mice have now been produced using somatic cells for nuclear transplantation. Animal cloning is still very inefficient with on average less than 10% of the cloned embryos transferred resulting in a live offspring. However successful cloning of a variety of different species and by a number of different laboratory groups has generated tremendous interest

M. E. Westhusin; C. R. Long; T. Shin; J. R. Hill; C. R. Looney; J. H. Pryor; J. A. Piedrahita

2001-01-01

157

Generalized multiple scale reproducing kernel particle methods  

Microsoft Academic Search

An approach to unify reproducing kernel methods under one large umbrella and an extension to include time and spatial shifting are proposed. The study is divided into three major topics. The groundwork is set by revisiting the Fourier analysis of discrete systems. The multiresolution concept and its significance in devising the reproducing kernel methods and its discrete counterpart, reproducing kernel

Wing Kam Liu; Yijung Chen; R. Aziz Uras; Chin Tang Chang

1996-01-01

158

Hot compression behavior of the AZ91 magnesium alloy produced by high pressure die casting  

Microsoft Academic Search

The hot deformation behavior of a Mg–9Al–1Zn alloy produced by high pressure die casting has been investigated by means of compression tests in the temperature and strain rate ranges of 125–300°C and 1.6×10?5 to 10?1s?1, respectively. The samples were deformed in the high pressure die casting state or after an exposure at 415°C for 2h to evaluate any different response

E. Cerri; P. Leo; P. P. De Marco

2007-01-01

159

Superplastic behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die cast  

Microsoft Academic Search

The room temperature and hot tensile properties of AZ91 magnesium alloy produced by high pressure die cast after friction stir processing (FSP) were studied in the present paper. Such process is a modification of classical friction stir welding one in which the sheets are not joined but the stirring action of the tool, on the bulk material, is used to

P. Cavaliere; P. P. De Marco

2007-01-01

160

Removal of As, Cd, Pb, and Zn from contaminated soil by high biomass producing plants  

Microsoft Academic Search

The uptake of As, Cd, Pb, and Zn and potential phytoremediation efficiency of five high biomass producing crops, white sweetclover (Melilotus alba L.), red clover (Trifolium pratense L.), curled mallow (Malva verticillata L.), saf- flower (Carthamus tinctorius L.) and hemp (Cannabis sativa L.) commonly used as grazing and\\/or energy crops was evaluated in both pot and field experiments at soils

P. Tlustoš; J. Száková; J. Hrubý; I. Hartman; J. Najmanová; J. Ned?lník; D. Pavlíková; M. Batysta

2006-01-01

161

Optical Particle Trapping with Higher-order Doughnut Beams Produced Using High Efficiency Computer Generated Holograms  

Microsoft Academic Search

Laser beams containing higher-order phase singularities can be produced with high efficiency computer generated holograms made with very simple equipment. Using such holograms in an optical tweezers experiment we have successfully trapped reflective and absorptive particles in the dark central spot of a focused charge 3 singularity beam. Angular momentum absorbed from the beam can set particles into rotation.

H. He; N. R. Heckenberg; H. Rubinsztein-Dunlop

1995-01-01

162

HF echoes from ionization potentially produced by high-altitude discharges  

SciTech Connect

In this paper the authors report on recent radar measurements taken during the month of October 1994 with the LDG HF radar in the Ivory Coast, Africa as part of the International Equatorial Electrojet Year. The purpose of this experimental effort in part was to study the effects of thunderstorms on the ionosphere. At the same time, the authors decided to carry out a set of experiments of an exploratory nature to look for echoes that could potentially arise from ionization produced in the mesosphere. The two leading candidates for producing transient ionization in the mesosphere are meteors and high-altitude discharges. Each is discussed in the context of these measurements.

Roussel-Dupre, R.; Fitzgerald, T.J.; Symbalisty, E. [and others

1997-04-01

163

Highly oil-producing microalgae selected through directed-evolution on a microfludic chip  

NASA Astrophysics Data System (ADS)

Some species of photosynthetic microalgae produce signi?cant amounts of oil which can be easily converted to diesel fuel. However, as it stands today, biodiesel is signi?cantly more expensive than fossil fuels. We wish to improve the oil yield and production rate of a single species of microalgae through directed evolution. We propose to utilize our microfabication technology to create microhabitats to control the nutrient environment of the species, monitor oil production through Raman Spectroscopy, and punish colonies of algae which have low oil yield. We believe this process will produce a mutant species with a high oil yield.

Mestler, Troy; Estevez-Torres, Andre; Lambert, Guillaume; Austin, Robert H.

2009-03-01

164

Breakdown voltages for discharges initiated from plasma pulses produced by high-frequency excimer lasers  

SciTech Connect

The triggering ability under the different electric field was investigated using a KrF excimer laser with a high repetition rate of kilohertz order. Measurements were made of the magnitude of impulse voltages that were required to initiate a discharge from plasmas produced by a high-frequency excimer laser. Breakdown voltages were found to be reduced by 50% through the production of plasmas in the discharge gap by a high-frequency excimer laser. However, under direct-current electric field, triggering ability decreased drastically due to low plasma density. It is considered that such laser operation applied for laser-triggered lightning due to the produced location of plasma channel is formed under the impulse electric field since an electric field of the location drastically reduces temporary when the downward leader from thunderclouds propagates to the plasma channel.

Yamaura, Michiteru [Department of Electrical and Electronic Engineering, Faculty of Science and Engineering, Saga University, 1 Honjo-machi, Saga 840-8502 (Japan)

2006-06-19

165

Precipitation-strengthened high-strength, high-conductivity Cu-Cr-Nb alloys produced by chill blockmelt spinning  

Microsoft Academic Search

There are many potential applications for materials that possess a combination of high strength, high conductivity, and good long term stability at elevated temperatures. In an effort to achieve this combination of properties a series of Cu-based alloys containing 2 to 10 a\\/o Cr and 1 to 5 a\\/o Nb were produced by chill block melt spinning (CBMS). The melt

1989-01-01

166

Liquid State Forging: Novel Potentiality to Produce High Performance Components, Process, Plant and Tooling  

NASA Astrophysics Data System (ADS)

The paper deals about a new patented process able to the production of high resistance and high toughness parts, taking into consideration also the tooling need. The molten alloy is introduced into the die cavity at low pressure, then the alloy is forged. The forging action takes place during the alloy solidification process, favouring the reduction of the duration of the process and the production of parts characterised by very high mechanical and ductility properties. The very high mechanical characteristics of the produced parts are obtained thank to their very low porosity content, as well as to their unique microstructure features. Moreover, the process allow the optimisation of the yield of the alloy, in fact the feeding system and the risers are practically absent, this means minimum production of scraps to be recycled. After a short description of the main features of the equipment and of the process, the work take into consideration the aluminium based produced parts, in their as cast state and after T6 heat treatment, comparing their characteristics with those obtainable by the most traditional low pressure and gravity casting processes. In particular, samples for the evaluation of the mechanical properties have been machined from the produced parts to obtain their tensile strength, together with their ductility characteristics. The maximum attained hardness values have also been evaluated. Tensile strength higher than 440 MPa, with elongation up to 18% with hardness higher than 125 HB are easily attainable on Al alloys type A356. Light microscopy observations performed on the transverse section of polished samples and the analysis of the fracture surfaces after mechanical tests allowed to focus the attention on the microstructure details and to highlight the ductile aspects of the fracture to confirm the high quality and high performance of the produced parts.

Rosso, M.; Zago, A.; Claus, P.; Motoiu, P.

2007-04-01

167

Method for producing ceramic composition having low friction coefficient at high operating temperatures  

DOEpatents

A method for producing a stable ceramic composition having a surface with a low friction coefficient and high wear resistance at high operating temperatures. A first deposition of a thin film of a metal ion is made upon the surface of the ceramic composition and then a first ion implantation of at least a portion of the metal ion is made into the near surface region of the composition. The implantation mixes the metal ion and the ceramic composition to form a near surface composite. The near surface composite is then oxidized sufficiently at high oxidizing temperatures to form an oxide gradient layer in the surface of the ceramic composition.

Lankford, Jr., James (San Antonio, TX)

1988-01-01

168

Method to Produce Flexible Ceramic Thermal Protection System Resistant to High Aeroacoustic Noise  

NASA Technical Reports Server (NTRS)

A method of producing a three dimensional angle interlock ceramic fiber which is stable to high aeroacoustic noise of about 170 decibels and to high temperatures of about 2500 F is disclosed. The method uses multiple separate strands of a ceramic fiber or ceramic tow suitable for weaving having multiple warp fibers and multiple fill fibers woven with a modified fly-shuttle loom or rapier shuttleless loom which has nip rolls, a modified fabric advancement mechanism and at least eight harnesses in connection with a Dobby pattern chain utilizing sufficient heddles for each warp fiber and a reed which accommodates at least 168 ends per inch. The method produces a multilayered top fabric, rib fabric and single-layered bottom fabric.

Sawko, Paul M. (Inventor); Calamito, Dominic P. (Inventor); Jong, Anthony (Inventor)

1997-01-01

169

Looking for the pick of the bunch: high-throughput screening of producing microorganisms with biosensors.  

PubMed

The engineering of microbial strains for the production of small molecules of biotechnological interest is a time-consuming, laborious and expensive process. This can be mostly attributed to the fact that good producers cannot be readily obtained by high-throughput screening approaches since increased product formation usually does not confer a clear phenotype to producing strain variants. Recently, advances were made in the design and construction of genetically encoded RNA aptamer-based or transcription factor-based biosensors for detecting small molecules at the single-cell level. The first promising examples for the application of these molecular biosensors in combination with fluorescent-activated cell sorting as a high-throughput screening device demonstrated the value and potential of these new tools for microbial strain development. PMID:24480185

Schallmey, Marcus; Frunzke, Julia; Eggeling, Lothar; Marienhagen, Jan

2014-04-01

170

Fatigue behaviour of friction stir processed AZ91 magnesium alloy produced by high pressure die casting  

Microsoft Academic Search

The room temperature fatigue properties of AZ91 magnesium alloy produced by high pressure die casting (HPDC) as cast, heat treated, friction stir processed (FSP) and FSP and heat treated were studied. The fatigue properties of the material were evaluated for the HPDC magnesium alloy in the as-received state and after a solution treatment at 415 °C for 2 h and an ageing

P.. Cavaliere; P. P. De Marco

2007-01-01

171

Process for producing synthetic natural gas and high octane motor fuel components  

Microsoft Academic Search

Engelhard Minerals and Chemicals Corp.'s process produces both synthetic natural gas and high-octane motor-fuel blending stock by catalytically reforming a naphtha feedstock containing naphthenes of low severity, thereby maximizing production of aromatics and hydrogen by dehydrogenation of naphthenes and minimizing hydrocracking of paraffins. The effluent from the reforming reaction zone is cooled and separated in a first separation zone into

W. C. Pfefferle; W. P. Jr. Hettinger

1978-01-01

172

Polydiacetylene-based high-throughput screen for surfactin producing strains of Bacillus subtilis.  

PubMed

Although traditional mutation is still an attractive approach for strain improvement, it is tedious, time-consuming, and inefficient to screen for surfactin producing strains. To overcome this, we developed a high-throughput screening method for surfactin producing mutants by applying polydiacetylene (PDA) vesicles as sensors with visible chromatic change from blue to red, detected as colorimetric response (CR%) signal, which can even semi-quantify the yields of surfactin. Bacillus subtilis 723 was used as parent strain and multiply mutated with atmospheric and room temperature plasma (ARTP). Mutants were cultured in MicroFlask by Duetz (24 square deepwell plates, Applikon Biotechnology) and surfactin titers were tested in 96-well plates with PDA vesicles. Mutants with surfactin titers above150 mg/L (CR% value above 26%) were selected as high-yield strains and further quantified by HPLC. By integrating MicroFlask cultivation and the PDA vesicles detection, we screened 27,000 mutants and found 37 high-yield strains. From these, one mutant produced 473.6 mg/L surfactin (including 353.1 mg/L C15 surfactin), which was 5.4-fold than that of the parent strain. This method is efficient, cost-effective and provides wider application in screening for various surfactants. PMID:24498439

Zhu, Lingyan; Xu, Qing; Jiang, Ling; Huang, He; Li, Shuang

2014-01-01

173

Process for producing high purity isoolefins and dimers thereof by dissociation of ethers  

DOEpatents

Alkyl tertiary butyl ether or alkyl tertiary amyl ether is dissociated by vapor phase contact with a cation acidic exchange resin at temperatures in the range of 150 to 250 F at LHSV of 0.1 to 20 to produce a stream consisting of unreacted ether, isobutene or isoamylene and an alcohol corresponding to the alkyl radical. After the alcohol is removed, the ether/isoolefin stream may be fractionated to obtain a high purity isoolefin (99+%) or the ether/isoolefin stream can be contacted in liquid phase with a cation acidic exchange resin to selectively dimerize the isoolefin in a highly exothermic reaction, followed by fractionation of the dimerization product to produce high purity diisoolefin (97+%). In the case where the alkyl is C[sub 3] to C[sub 6] and the corresponding alcohol is produced on dissociation of the ether, combined dissociation-distillation may be carried out such that isoolefin is the overhead product and alcohol the bottom. 2 figs.

Smith, L.A. Jr.; Jones, E.M. Jr.; Hearn, D.

1984-05-08

174

Polydiacetylene-Based High-Throughput Screen for Surfactin Producing Strains of Bacillus subtilis  

PubMed Central

Although traditional mutation is still an attractive approach for strain improvement, it is tedious, time-consuming, and inefficient to screen for surfactin producing strains. To overcome this, we developed a high-throughput screening method for surfactin producing mutants by applying polydiacetylene (PDA) vesicles as sensors with visible chromatic change from blue to red, detected as colorimetric response (CR%) signal, which can even semi-quantify the yields of surfactin. Bacillus subtilis 723 was used as parent strain and multiply mutated with atmospheric and room temperature plasma (ARTP). Mutants were cultured in MicroFlask by Duetz (24 square deepwell plates, Applikon Biotechnology) and surfactin titers were tested in 96-well plates with PDA vesicles. Mutants with surfactin titers above150 mg/L (CR% value above 26%) were selected as high-yield strains and further quantified by HPLC. By integrating MicroFlask cultivation and the PDA vesicles detection, we screened 27,000 mutants and found 37 high-yield strains. From these, one mutant produced 473.6 mg/L surfactin (including 353.1 mg/L C15 surfactin), which was 5.4-fold than that of the parent strain. This method is efficient, cost-effective and provides wider application in screening for various surfactants.

Zhu, Lingyan; Xu, Qing; Jiang, Ling; Huang, He; Li, Shuang

2014-01-01

175

Poor Reproducibility of Allergic Rhinitis SNP Associations  

PubMed Central

Replication of reported associations is crucial to the investigation of complex disease. More than 100 SNPs have previously been reported as associated with allergic rhinitis (AR), but few of these have been replicated successfully. To investigate the general reproducibility of reported AR-associations in candidate gene studies, one Swedish (352 AR-cases, 709 controls) and one Singapore Chinese population (948 AR-cases, 580 controls) were analyzed using 49 AR-associated SNPs. The overall pattern of P-values indicated that very few of the investigated SNPs were associated with AR. Given published odds ratios (ORs) most SNPs showed high power to detect an association, but no correlations were found between the ORs of the two study populations or with published ORs. None of the association signals were in common to the two genome-wide association studies published in AR, indicating that the associations represent false positives or have much lower effect-sizes than reported.

Nilsson, Daniel; Andiappan, Anand Kumar; Hallden, Christer; Tim, Chew Fook; Sall, Torbjorn

2013-01-01

176

Simulation of mass spectra produced in collisions of highly charged ions with sodium clusters  

NASA Astrophysics Data System (ADS)

Neutral sodium clusters containing up to several hundred atoms are multi-ionized in low-energy collisions with Xe28+ projectiles (560 keV). The time-of-flight mass spectra of singly and multiply charged sodium clusters, produced in single collisions, are measured with a high-resolution reflectron-type mass spectrometer. They are compared with theoretical spectra based on Monte Carlo simulations. The comparison allows one to evaluate the energy transferred to the cluster during the ionizing collision and suggests for high cluster charges a multi-fragmentation process, where nearly all charges are emitted creating a low-charged residual ion.

Ntamack, G. E.; Huber, B. A.; Chandezon, F.; Njock, M. G. Kwato; Guet, C.

2002-06-01

177

Structure of a novel highly branched alpha-glucan enzymatically produced from maltodextrin.  

PubMed

The bacterial strain PP710, isolated from soil and identified as Paenibacillus species, produced a low-digestibility alpha-glucan containing a large amylase-resistant portion. This alpha-glucan was obtained in high yields from maltodextrin (dextrose equivalent 3) by using the condensed culture supernatant of the strain as the enzyme preparation. The water-soluble dietary fiber content of the low-digestibility alpha-glucan was 80.2%, and showed resistance to a rat intestinal enzyme preparation. The alpha-glucan was found to be a novel highly branched alpha-glucan by acid hydrolysis, NMR analysis, gel permeation chromatography, methylation analysis, and enzymatic digestion. PMID:19740459

Tsusaki, Keiji; Watanabe, Hikaru; Nishimoto, Tomoyuki; Yamamoto, Takuo; Kubota, Michio; Chaen, Hiroto; Fukuda, Shigeharu

2009-11-01

178

Prepulse Effect for Recombining Plasma Produced by Ultrashort High-Intensity Lasers  

NASA Astrophysics Data System (ADS)

We compare the space-resolved characteristics of carbon plasmas produced using a single ultrashort high-intensity laser pulse (>1019 W/cm2) of less than 800 fs duration and those using a combination of a 100 ps duration prepulse and an ultrashort laser pulse. Profiles of electron density and electron temperature as functions of position from the original target surface are derived from the measured one-dimensional space-resolved soft X-ray spectra. The electron density was estimated from the Inglis-Teller limit and from a comparison of the experimental and the calculated profiles of Lyman series lines. The electron density gradually increases up to the critical density of the incident laser light near the target surface, and the density gradient is much steeper when the plasma is produced using the single ultrashort pulse. The electron temperature was estimated from the intensity ratio of the H-like Ly-? line to the He-like He-? line and that of the H-like Ly-? line to its satellite lines. The plasmas produced using the prepulse additionally are relatively uniform with moderate electron density and temperature, and a larger portion of the K-shell lines from carbon ions is produced in the recombining phase, rather than in the heating phase. With a suitable choice of prepulses, the spatial and temporal profiles of the plasma density and temperature can be controlled, which can facilitate applications of the laser-produced plasmas to various kinds of research, such as producing a gain medium for X-ray lasers.

Choi, Il Woo; Daido, Hiroyuki; Sakaya, Noriyuki; Tohyama, Yusuke; Izumi, Nobuhiko; Kodama, Ryosuke; Kitagawa, Yoneyoshi; Tanaka, Kazuo A.; Mima, Kunioki

2001-03-01

179

Isolation of Bacillus subtilis (chungkookjang), a poly-gamma-glutamate producer with high genetic competence.  

PubMed

A bacterium with high poly-gamma-glutamate (PGA) productivity was isolated from the traditional Korean seasoning, Chung-Kook-Jang. This bacterium could be classified as a Bacillus subtilis, but sporulation in culture was infrequent in the absence of Mn2+. It was judged to be a variety of B. subtilis and designated B. subtilis (chungkookjang). L-Glutamate significantly induced PGA production, and highly elongated PGAs were synthesized. The volumetric yield reached 13.5 mg ml(-1) in the presence of 2% L-glutamate. The D-glutamate content was over 50% in every PGA produced under the conditions used. During PGA production, glutamate racemase activity was found in the cells, suggesting that the enzyme is involved in the D-glutamate supply. Molecular sizes of PGAs were changed by the salt concentration in the medium; PGAs with comparatively low molecular masses were produced in culture media containing high concentrations of NaCl. B. subtilis (chungkookjang) harbors no plasmid and is the first B. subtilis strain reported with both naturally high PGA productivity and high genetic competence. PMID:11778891

Ashiuchi, M; Kamei, T; Baek, D H; Shin, S Y; Sung, M H; Soda, K; Yagi, T; Misono, H

2001-12-01

180

High-Throughput Sorting of the Highest Producing Cell via a Transiently Protein-Anchored System  

PubMed Central

Developing a high-throughput method for the effecient selection of the highest producing cell is very important for the production of recombinant protein drugs. Here, we developed a novel transiently protein-anchored system coupled with fluorescence activated cell sorting (FACS) for the efficient selection of the highest producing cell. A furin cleavage peptide (RAKR) was used to join a human anti-epithelial growth factor antibody (?EGFR Ab) and the extracellular-transmembrane-cytosolic domains of the mouse B7-1 antigen (B7). The furin inhibitor can transiently switch secreted ?EGFR Ab into a membrane-anchored form. After cell sorting, the level of membrane ?EGFR Ab-RAKR-B7 is proportional to the amount of secreted ?EGFR Ab in the medium. We further selected 23 ?EGFR Ab expressing cells and demonstrated a high correlation (R2?=?0.9165) between the secretion level and surface expression levels of ?EGFR Ab. These results suggested that the novel transiently protein-anchored system can easily and efficiently select the highest producing cells, reducing the cost for the production of biopharmaceuticals.

Chiang, I-Shiuan; Chuang, Chih-Hung; Kao, Chien-Han; Cheng, Ta-Chun; Wang, Yeng-Tseng; Lin, Wen-Wei; Chen, Bing-Mae; Roffler, Steve R.; Huang, Ming-Yii; Cheng, Tian-Lu

2014-01-01

181

Generation and Evaluation of High ?-Glucan Producing Mutant Strains of Sparassis crispa  

PubMed Central

A chemical mutagenesis technique was employed for development of mutant strains of Sparassis crispa targeting the shortened cultivation time and the high ?-glucan content. The homogenized mycelial fragments of S. crispa IUM4010 strain were treated with 0.2 vol% methyl methanesulfonate, an alkylating agent, yielding 199 mutant strains. Subsequent screening in terms of growth and ?-glucan content yielded two mutant strains, B4 and S7. Both mutants exhibited a significant increase in ?-glucan productivity by producing 0.254 and 0.236 mg soluble ?-glucan/mg dry cell weight for the B4 and S7 strains, respectively, whereas the wild type strain produced 0.102 mg soluble ?-glucan/mg dry cell weight. The results demonstrate the usefulness of chemical mutagenesis for generation of mutant mushroom strains.

Kim, Seung-Rak; Kang, Hyeon-Woo

2013-01-01

182

The origin of replicators and reproducers  

PubMed Central

Replicators are fundamental to the origin of life and evolvability. Their survival depends on the accuracy of replication and the efficiency of growth relative to spontaneous decay. Infrabiological systems are built of two coupled autocatalytic systems, in contrast to minimal living systems that must comprise at least a metabolic subsystem, a hereditary subsystem and a boundary, serving respective functions. Some scenarios prefer to unite all these functions into one primordial system, as illustrated in the lipid world scenario, which is considered as a didactic example in detail. Experimentally produced chemical replicators grow parabolically owing to product inhibition. A selection consequence is survival of everybody. The chromatographized replicator model predicts that such replicators spreading on surfaces can be selected for higher replication rate because double strands are washed away slower than single strands from the surface. Analysis of real ribozymes suggests that the error threshold of replication is less severe by about one order of magnitude than thought previously. Surface-bound dynamics is predicted to play a crucial role also for exponential replicators: unlinked genes belonging to the same genome do not displace each other by competition, and efficient and accurate replicases can spread. The most efficient form of such useful population structure is encapsulation by reproducing vesicles. The stochastic corrector model shows how such a bag of genes can survive, and what the role of chromosome formation and intragenic recombination could be. Prebiotic and early evolution cannot be understood without the models of dynamics.

Szathmary, Eors

2006-01-01

183

Reversible and Reproducible Giant Universal Electroresistance Effect  

NASA Astrophysics Data System (ADS)

After the prediction of the giant electroresistance effect, much work has been carried out to find this effect in practical devices. We demonstrate a novel way to obtain a large electroresistance (ER) effect in the multilayer system at room temperature. The current-in-plane (CIP) electric transport measurement is performed on the multilayer structure consisting of (011)-Pb(Mg1/3Nb2/3)O3-PbTiO3(PMN-PT)/Ta/Al-O/metal. It is found that the resistance of the top metallic layer shows a hysteretic behavior as a function electric field, which corresponds well with the substrate polarization versus electric field (P—E) loop. This reversible hysteretic R—E behavior is independent of the applied magnetic field as well as the magnetic structure of the top metallic layer and keeps its memory state. This novel memory effect is attributed to the polarization reversal induced electrostatic potential, which is felt throughout the multilayer stack and is enhanced by the dielectric Al-O layer producing unique hysteretic, reversible, and reproducible resistance switching behavior. This novel universal electroresistance effect will open a new gateway to the development of future multiferroic memory devices operating at room temperature.

Syed, Rizwan; Zhang, Sen; Yu, Tian; Zhao, Yong-Gang; Zhang, Shu-Feng; Han, Xiu-Feng

2011-10-01

184

High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays  

SciTech Connect

Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

2007-04-17

185

Accelerating in the Future: Lasers Start to Produce Quality High Energy Electron Beams  

ScienceCinema

Twenty-five years ago, a new method was proposed for the acceleration of electrons to high energies using lasers. The simplest implementation of a so-called laser wakefield accelerator involves sending an intense laser pulse through a gas to ionize it and form a plasma of dissociated electrons and ions. The radiation pressure of the laser pushes the plasma electrons aside, creating a density modulation, or 'wake'. This changing electron density can result in fields that accelerate particles thousands of times more strongly than in conventional machines, accelerating electrons to high energies in short distances. The compactness of these accelerators would allow higher energies for the frontiers of fundamental physics and make clinical and laboratory applications of accelerators practical. In work that brings the promise of laser-driven particle accelerators dramatically closer to reality, we have produced high-quality electron beams in a plasma channel based accelerating structure akin to an optical fiber of only a few millimeters long.

186

Reproducibility of endoscopic sphincter of Oddi manometry  

Microsoft Academic Search

Results from endoscopic sphincter of Oddi manometry are being used to support the diagnosis of sphincter dysfunction in patients with unexplained pain after cholecystectomy. However, there are few data on the reproducibility of manometric records or motility diagnosis during a second test. In this study, the reproducibility of manometric records was assessed in 12 patients with pain after cholecystectomy by

A. Thune; J. Scicchitano; I. Roberts-Thomson; J. Toouli

1991-01-01

187

Reproducibility of Research Algorithms in GOES-R Operational Software  

NASA Astrophysics Data System (ADS)

The research to operations transition for satellite observations is an area of active interest as identified by The National Research Council Committee on NASA-NOAA Transition from Research to Operations. Their report recommends improved transitional processes for bridging technology from research to operations. Assuring the accuracy of operational algorithm results as compared to research baselines, called reproducibility in this paper, is a critical step in the GOES-R transition process. This paper defines reproducibility methods and measurements for verifying that operationally implemented algorithms conform to research baselines, demonstrated with examples from GOES-R software development. The approach defines reproducibility for implemented algorithms that produce continuous data in terms of a traditional goodness-of-fit measure (i.e., correlation coefficient), while the reproducibility for discrete categorical data is measured using a classification matrix. These reproducibility metrics have been incorporated in a set of Test Tools developed for GOES-R and the software processes have been developed to include these metrics to validate both the scientific and numerical implementation of the GOES-R algorithms. In this work, we outline the test and validation processes and summarize the current results for GOES-R Level 2+ algorithms.

Kennelly, E.; Botos, C.; Snell, H. E.; Steinfelt, E.; Khanna, R.; Zaccheo, T.

2012-12-01

188

High-resolution music with inaudible high-frequency components produces a lagged effect on human electroencephalographic activities.  

PubMed

High-quality digital sound sources with inaudible high-frequency components (above 20 kHz) have become available because of recent advances in information technology. Listening to such sounds has been shown to increase the ?-band power of an electroencephalogram (EEG). The present study scrutinized the time course of this effect by recording EEG along with autonomic measures (skin conductance level and heart rate) and facial electromyograms (corrugator supercilii and zygomaticus major). Twenty university students (19-24 years old) listened to two types of a 200-s musical excerpt (J. S. Bach's French Suite No. 5) with or without inaudible high-frequency components using a double-blind method. They were asked to rate the sound quality and to judge which excerpt contained high-frequency components. High-? EEG power (10.5-13 Hz) was larger for the excerpt with high-frequency components than for the excerpt without them. This effect was statistically significant only in the last quarter of the period (150-200 s). Participants were not able to distinguish between the excerpts, which did not produce any discernible differences in subjective, autonomic, and facial muscle measures. This study shows that inaudible high-frequency components have an impact on human brain activity without conscious awareness. Unlike a standard test for sound quality, at least 150 s of exposure is required to examine this effect in future research. PMID:24722228

Kuribayashi, Ryuma; Yamamoto, Ryuta; Nittono, Hiroshi

2014-06-18

189

High-performance nanocrystalline PrFeB-based magnets produced by intensive milling  

NASA Astrophysics Data System (ADS)

The intensive milling technique has been used to produce nanocrystalline isotropic PrFeB-based powders. Highly coercive powders were obtained using the base composition R16T76B8 (R: rare earth, T: transition metal) with Dy and Zr additions achieving a high value of ?0Hc=2.66 T for Pr15Dy1Fe75.9B8Zr0.1. The influence of Dy and Zr, and the substitution of Pr by Nd, on the microstructural and magnetic properties have been studied. Reduction of the R content, increase of the T content, and the presence of Co in the starting composition gave rise to an improved performance with values of Jr=0.92 T, ?0Hc=1.25 T, and (BH)max=140 kJ/m3 for Pr9Nd3Dy1Fe72Co8B6.9Zr0.1, originating from a very fine microstructure with a mean grain size of 20 nm. Furthermore, intensive milling has been shown to be a very versatile technique to produce high-performance nanocomposite magnets by blending this latter alloy with different fractions of soft magnetic ?-Fe (x=5-35 wt % Fe). A 25 wt % Fe addition resulted in an optimum combination of magnetic properties with a very high (BH)max value of 178 kJ/m3 due to an effective exchange coupling between the hard- and soft-magnetic phases. A Curie temperature of about 370 °C was observed for this magnet. Demagnetization recoil loops of both single-phase and nanocomposite magnets showed clear differences with relatively open minor loops in the case of the latter due to the exchange-spring mechanism present. ?J plots for the nanocomposite magnets showed a negative deviation of the demagnetizing remanence from the Wohlfarth model, indicative of exchange-coupling interactions being dominant.

Bollero, A.; Gutfleisch, O.; Müller, K.-H.; Schultz, L.; Drazic, G.

2002-05-01

190

One-step hydrotreatment of vegetable oil to produce high quality diesel-range alkanes.  

PubMed

A one-step hydrotreatment of vegetable oil combining deoxygenation and isomerization to directly produce low cloud point, high quality diesel is devised. The Pt/zeolite bifunctional catalysts prepared by using SAPO-11 and ZSM-22 zeolites as supports are used in this process. Catalytic reactions are conducted in a fixed-bed reactor under a hydrogen atmosphere. Over the bifunctional catalyst, 100 % conversion of soybean oil is obtained at 357 °C, 4 MPa, and 1 h(-1), and 80 % organic liquid yield is achieved, which is close to the maximum theoretical liquid yield. In the organic products, the alkanes selectivity is 100 % with an i-alkanes selectivity above 63 %. NH(3)-temperature programmed desorption (TPD), pyridine IR spectroscopy, and other characterization techniques are used to study the effect of the support acidity on the reaction pathway. Over the Pt/zeolite bifunctional catalyst with less strong Lewis acid sites, the reaction proceeds via the decarboxylation plus decarbonylation pathway. This one-step method provides a new strategy to produce low cloud point, high quality diesel from biomass feedstock in a more economic and attractive way. PMID:22764086

Wang, Congxin; Tian, Zhijian; Wang, Lei; Xu, Renshun; Liu, Qianhe; Qu, Wei; Ma, Huaijun; Wang, Bingchun

2012-10-01

191

Multibeneficial Use of Produced Water through High-Pressure Membrane Treatment and Capacitive Deionization Technology.  

National Technical Information Service (NTIS)

Large volumes of produced water are generated during natural gas production. Beneficial use of produced water has become an attractive solution to produced water management by providing additional and reliable water supplies and reducing the cost for disp...

D. Heil G. Wang J. E. Drewes P. Xu

2005-01-01

192

Semiautomated, Reproducible Batch Processing of Soy  

NASA Technical Reports Server (NTRS)

A computer-controlled apparatus processes batches of soybeans into one or more of a variety of food products, under conditions that can be chosen by the user and reproduced from batch to batch. Examples of products include soy milk, tofu, okara (an insoluble protein and fiber byproduct of soy milk), and whey. Most processing steps take place without intervention by the user. This apparatus was developed for use in research on processing of soy. It is also a prototype of other soy-processing apparatuses for research, industrial, and home use. Prior soy-processing equipment includes household devices that automatically produce soy milk but do not automatically produce tofu. The designs of prior soy-processing equipment require users to manually transfer intermediate solid soy products and to press them manually and, hence, under conditions that are not consistent from batch to batch. Prior designs do not afford choices of processing conditions: Users cannot use previously developed soy-processing equipment to investigate the effects of variations of techniques used to produce soy milk (e.g., cold grinding, hot grinding, and pre-cook blanching) and of such process parameters as cooking times and temperatures, grinding times, soaking times and temperatures, rinsing conditions, and sizes of particles generated by grinding. In contrast, the present apparatus is amenable to such investigations. The apparatus (see figure) includes a processing tank and a jacketed holding or coagulation tank. The processing tank can be capped by either of two different heads and can contain either of two different insertable mesh baskets. The first head includes a grinding blade and heating elements. The second head includes an automated press piston. One mesh basket, designated the okara basket, has oblong holes with a size equivalent to about 40 mesh [40 openings per inch (.16 openings per centimeter)]. The second mesh basket, designated the tofu basket, has holes of 70 mesh [70 openings per inch (.28 openings per centimeter)] and is used in conjunction with the press-piston head. Supporting equipment includes a soy-milk heat exchanger for maintaining selected coagulation temperatures, a filter system for separating okara from other particulate matter and from soy milk, two pumps, and various thermocouples, flowmeters, level indicators, pressure sensors, valves, tubes, and sample ports

Thoerne, Mary; Byford, Ivan W.; Chastain, Jack W.; Swango, Beverly E.

2005-01-01

193

High Prevalence of Mucosa-Associated E. coli Producing Cyclomodulin and Genotoxin in Colon Cancer  

PubMed Central

Some Escherichia coli strains produce toxins designated cyclomodulins (CMs) which interfere with the eukaryotic cell cycle of host cells, suggesting a possible link between these bacteria and cancers. There are relatively few data available concerning the colonization of colon tumors by cyclomodulin- and genotoxic-producing E. coli. We did a qualitative and phylogenetic analysis of mucosa-associated E. coli harboring cyclomodulin-encoding genes from 38 patients with colorectal cancer (CRC) and 31 with diverticulosis. The functionality of these genes was investigated on cell cultures and the genotoxic activity of strains devoid of known CM-encoding gene was investigated. Results showed a higher prevalence of B2 phylogroup E. coli harboring the colibatin-producing genes in biopsies of patients with CRC (55.3%) than in those of patients with diverticulosis (19.3%), (p<0.01). Likewise, a higher prevalence of B2 E. coli harboring the CNF1-encoding genes in biopsies of patients with CRC (39.5%) than in those of patients with diverticulosis (12.9%), (p?=?0.01). Functional analysis revealed that the majority of these genes were functional. Analysis of the ability of E. coli to adhere to intestinal epithelial cells Int-407 indicated that highly adherent E. coli strains mostly belonged to A and D phylogroups, whatever the origin of the strains (CRC or diverticulosis), and that most E. coli strains belonging to B2 phylogroup displayed very low levels of adhesion. In addition, 27.6% (n?=?21/76) E. coli strains devoid of known cyclomodulin-encoding genes induced DNA damage in vitro, as assessed by the comet assay. In contrast to cyclomodulin-producing E. coli, these strains mainly belonged to A or D E. coli phylogroups, and exhibited a non significant difference in the distribution of CRC and diverticulosis specimens (22% versus 32.5%, p?=?0.91). In conclusion, cyclomodulin-producing E. coli belonging mostly to B2 phylogroup colonize the colonic mucosa of patients with CRC.

Sauvanet, Pierre; Raisch, Jennifer; Delmas, Julien

2013-01-01

194

Reproducibility and utility of dune luminescence chronologies  

NASA Astrophysics Data System (ADS)

Optically stimulated luminescence (OSL) dating of dune deposits has increasingly been used as a tool to investigate the response of aeolian systems to environmental change. Amalgamation of individual dune accumulation chronologies has been employed in order to distinguish regional from local geomorphic responses to change. However, advances in dating have produced chronologies of increasing complexity. In particular, questions regarding the interpretation of dune ages have been raised, including over the most appropriate method to evaluate the significance of suites of OSL ages when local 'noisy' and discontinuous records are combined. In this paper, these issues are reviewed and the reproducibility of dune chronologies is assessed. OSL ages from two cores sampled from the same dune in the northeast Rub' al Khali, United Arab Emirates, are presented and compared, alongside an analysis of previously published dune ages dated to within the last 30 ka. Distinct periods of aeolian activity and preservation are identified, which can be tied to regional climatic and environmental changes. This case study is used to address fundamental questions that are persistently asked of dune dating studies, including the appropriate spatial scale over which to infer environmental and climatic change based on dune chronologies, whether chronological hiatuses can be interpreted, how to most appropriately combine and display datasets, and the relationship between geomorphic and palaeoclimatic signals. Chronological profiles reflect localised responses to environmental variability and climatic forcing, and amalgamation of datasets, with consideration of sampling resolution, is required; otherwise local factors are always likely to dominate. Using net accumulation rates to display ages may provide an informative approach of analysing and presenting dune OSL chronologies less susceptible to biases resulting from insufficient sampling resolution.

Leighton, Carly L.; Thomas, David S. G.; Bailey, Richard M.

2014-02-01

195

Kinematics used by world class tennis players to produce high-velocity serves.  

PubMed

The purpose of this study was to quantify ranges and speeds of movement, from shoulder external rotation to ball impact, in the tennis service actions of world class players. Two electronically synchronised 200 Hz video cameras were used to record 20 tennis players during singles competition at the Sydney 2000 Olympic games. Three-dimensional motion of 20 landmarks on each player and racquet were manually digitized. Based upon the mean values for this group, the elbow flexed to 104 degrees and the upper arm rotated into 172 degrees of shoulder external rotation as the front knee extended. From this cocked position, there was a rapid sequence of segment rotations. The order of maximum angular velocities was trunk tilt (280 degrees/s), upper torso rotation (870 degrees/s), pelvis rotation (440 degrees/s), elbow extension (1510 degrees/s), wrist flexion (1950 degrees/s), and shoulder internal rotation. Shoulder internal rotation was greater for males (2420 degrees/s) than females (1370 degrees/s), which may be related to the faster ball velocity produced by the males (50.8 m/s) than the females (41.5 m/s). Although both genders produced segment rotations in the same order, maximum upper torso velocity occurred earlier for females (0.075 s before impact) than for males (0.058 s). At impact, the trunk was tilted 48 degrees above horizontal, the arm was abducted 101 degrees and the elbow, wrist, and lead knee were slightly flexed. Male and female players should be trained to develop the kinematics measured in this study in order to produce effective high-velocity serves. PMID:14658245

Fleisig, Glenn; Nicholls, Rochelle; Elliott, Bruce; Escamilla, Rafael

2003-01-01

196

Metabolic engineering of a thermophilic bacterium to produce ethanol at high yield.  

PubMed

We report engineering Thermoanaerobacterium saccharolyticum, a thermophilic anaerobic bacterium that ferments xylan and biomass-derived sugars, to produce ethanol at high yield. Knockout of genes involved in organic acid formation (acetate kinase, phosphate acetyltransferase, and L-lactate dehydrogenase) resulted in a strain able to produce ethanol as the only detectable organic product and substantial changes in electron flow relative to the wild type. Ethanol formation in the engineered strain (ALK2) utilizes pyruvate:ferredoxin oxidoreductase with electrons transferred from ferredoxin to NAD(P), a pathway different from that in previously described microbes with a homoethanol fermentation. The homoethanologenic phenotype was stable for >150 generations in continuous culture. The growth rate of strain ALK2 was similar to the wild-type strain, with a reduction in cell yield proportional to the decreased ATP availability resulting from acetate kinase inactivation. Glucose and xylose are co-utilized and utilization of mannose and arabinose commences before glucose and xylose are exhausted. Using strain ALK2 in simultaneous hydrolysis and fermentation experiments at 50 degrees C allows a 2.5-fold reduction in cellulase loading compared with using Saccharomyces cerevisiae at 37 degrees C. The maximum ethanol titer produced by strain ALK2, 37 g/liter, is the highest reported thus far for a thermophilic anaerobe, although further improvements are desired and likely possible. Our results extend the frontier of metabolic engineering in thermophilic hosts, have the potential to significantly lower the cost of cellulosic ethanol production, and support the feasibility of further cost reductions through engineering a diversity of host organisms. PMID:18779592

Shaw, A Joe; Podkaminer, Kara K; Desai, Sunil G; Bardsley, John S; Rogers, Stephen R; Thorne, Philip G; Hogsett, David A; Lynd, Lee R

2008-09-16

197

Reproducibility of neuroendocrine lung tumor classification  

Microsoft Academic Search

For a tumor classification scheme to be useful, it must be reproducible and it must show clinical significance. Classification of neuroendocrine lung tumors is a difficult problem with little information about interobserver reproducibility. We sought to evaluate the classification of typical carcinoid (TC), atypical carcinoid (AC), large-cell neuroendocrine carcinoma (LCNEC), and small-cell carcinoma (SCC) tumors as proposed by W.D. Travis

William D Travis; Anthony A Gal; Thomas V Colby; David S Klimstra; Roni Falk; Michael N Koss

1998-01-01

198

Aircraft-produced Ice Particles in a Highly Supercooled Altocumulus Cloud.  

NASA Astrophysics Data System (ADS)

On 25 October during the 1986 Project FIRE Intensive Field Observations experiment, a NCAR King Air mission conducted over a ground-based polarization lidar site at Wausau, Wisconsin, sampled a highly supercooled (28° to 31°C) altocumulus perlucidus layer. Ground-based photography shows the concurrent formation of a contrail, which glaciated and gradually spread until producing an ice crystal optical display. According to wind-advected flight tracks, the aircraft-produced ice particles (APIP)-affected cloud volume was later sampled during zenith lidar measurements, indicating a 1.0 m s1 horizontal dispersion rate, and accidentally repenetrated by the aircraft during a spiral descent. In situ data obtained during the legs generating the APIP measured average liquid-water contents of 0.02-0.05 gm3, mean droplet diameters of 12-15 m, and droplet concentrations of 20-25 cm3. The resampling of the APIP region yielded ice crystal concentrations of 242 I1 at the original leg altitude, and 36 11 within an apparent crystal fallstreak. The background altocumulus ice particle concentration averaged 411.The APIP mechanism most likely to explain the observations involves the homogeneous freezing of contrail and natural cloud droplets induced by the rapid cooling behind the King Air propeller tips. In view of the wide use of aircraft of this type in basic and applied cloud physics research, caution should be exercised in interpreting ice particle data obtained when the likelihood of flight track resampling exists.

Sassen, Kenneth

1991-06-01

199

Mutation breeding of acetoin high producing Bacillus subtilis blocked in 2,3-butanediol dehydrogenase.  

PubMed

Bacillus subtilis mutants were obtained after the wild strain JNA 3-10 was mutagenized by UV irradiation coupled with diethyl sulfate. A visual filter assay was employed for the qualitative identification of 2,3-butanediol dehydrogenase (BDH) blocked B. subtilis. Selected mutants were tested for the activities of acetoin reductase (AR) and BDH. According to further batch fermentation, one mutant named JNA-UD-6 that produced 24.3 % more acetoin than JNA 3-10 with the corresponding byproducts of 2,3-butanediol decreased by 39.8 % was isolated. A nonsense mutation (p.Tyr118X) that precluded the synthesis of a full-length functional AR/BDH within the bdhA gene of JNA-UD-6 was detected. Acetoin production of JNA-UD-6 was further improved to about 53.9 g/L in a 5-L fermentor with 150 g/L glucose consumed. However,a small amount of 2,3-butanediol was found in late phase of JNA-UD-6 fermentation, and it was due to the existence of a putative gene that encoding a minor AR. This work proved a strategy to efficiently breeding an acetoin high producing strain by traditional mutation methods. PMID:23549901

Zhang, Xian; Zhang, Rongzhen; Yang, Taowei; Zhang, Jing; Xu, Meijuan; Li, Huazhong; Xu, Zhenghong; Rao, Zhiming

2013-10-01

200

Selection of high ginsenoside producing ginseng hairy root lines using targeted metabolic analysis.  

PubMed

To develop an experimental system for studying ginsenoside biosynthesis, we generated thousands of ginseng (Panax ginseng C.A. Meyer) hairy roots, genetically transformed roots induced by Agrobacterium rhizogenes, and analyzed the ginsenosides in the samples. 27 putative ginsenosides were detected in ginseng hairy roots. Quantitative and qualitative variations in the seven major ginsenosides were profiled in 993 ginseng hairy root lines using LC/MS and HPLC-UV. Cluster analysis of metabolic profiling data enabled us to select hairy root lines, which varied significantly in ginsenoside production. We selected hairy root lines producing total ginsenoside contents 4-5 times higher than that of a common hairy root population, as well as lines that varied in the ratio of the protopanaxadiol to protopanaxatriol type ginsenoside. Some of the hairy root lines produce only a single ginsenoside in relatively high amounts. These metabolites represent the end product of gene expression, thus metabolic profiling can give a broad view of the biochemical status or biochemical phenotype of a hairy root line that can be directly linked to gene function. PMID:15474561

Woo, Sung-Sick; Song, Ji-Sook; Lee, Ju-Yeon; In, Dong Su; Chung, Hwa-Jee; Liu, Jang Ryol; Choi, Dong-Woog

2004-10-01

201

High level compressive residual stresses produced in aluminum alloys by laser shock processing  

NASA Astrophysics Data System (ADS)

Laser shock processing (LSP) has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals. We present a configuration and results for metal surface treatments in underwater laser irradiation at 1064 nm. A convergent lens is used to deliver 1.2 J/cm 2 in a 8 ns laser FWHM pulse produced by 10 Hz Q-switched Nd:YAG, two laser spot diameters were used: 0.8 and 1.5 mm. Results using pulse densities of 2500 pulses/cm 2 in 6061-T6 aluminum samples and 5000 pulses/cm 2 in 2024 aluminum samples are presented. High level of compressive residual stresses are produced -1600 MPa for 6061-T6 Al alloy, and -1400 MPa for 2024 Al alloy. It has been shown that surface residual stress level is higher than that achieved by conventional shot peening and with greater depths. This method can be applied to surface treatment of final metal products.

Gomez-Rosas, G.; Rubio-Gonzalez, C.; Ocaña, J. L.; Molpeceres, C.; Porro, J. A.; Chi-Moreno, W.; Morales, M.

2005-11-01

202

A simple, robust and highly efficient transient expression system for producing antibodies.  

PubMed

Transient expression systems in mammalian cells have become the method of choice for producing research quantities of antibodies. Both the speed and yield of the available transient systems and the natural posttranslational modifications favor these systems above expression in lower eukaryotes, prokaryotes or stable cell lines. We describe an optimized mammalian transient expression system, capable of producing up to 400mg/L of native secreted antibodies in less than a week. The system is composed of commercially available components and is based on expression in the fast growing suspension cell line, FreeStyle™ 293-F (HEK-293F). The method depends on an optimal combination of a gene transfer method, an expression vector and cotransfection with expression enhancing plasmids, encoding the large T antigen of the SV40 virus and the cell cycle inhibitors p21 and p27. Optimization of all components of the expression system, by experimental design techniques, yielded maximal expression levels (including antibody isotypes IgG1, 2, 3, 4 and Fab fragments of various species). Expression volumes were scalable from 0.1 ml up to 1.2L in a simple shaker flask system in animal component free, low protein medium, enabling consistent production of relatively high amounts of a large number of native antibodies. PMID:23872061

Vink, Tom; Oudshoorn-Dickmann, Maroeska; Roza, Marcel; Reitsma, Jelte-Jan; de Jong, Rob N

2014-01-01

203

Genomic insights into high exopolysaccharide-producing dairy starter bacterium Streptococcus thermophilus ASCC 1275  

PubMed Central

Streptococcus thermophilus ASCC 1275 (ST 1275), a typical dairy starter bacterium, yields the highest known amount (~1,000?mg/L) of exopolysaccharide (EPS) in milk among the species of S. thermophilus. The addition of this starter in milk fermentation exhibited texture modifying properties for fermented dairy foods such as yogurt and cheese in the presence of EPS as its important metabolite. In this genomic study, a novel eps gene cluster for EPS assembly of repeating unit has been reported. It contains two-pair epsC-epsD genes which are assigned to determine the chain length of EPS. This also suggests this organism produces two types of EPSs – capsular and ropy EPS, as observed in our previous studies. Additionally, ST 1275 appears to exhibit effective proteolysis system and sophisticated stress response systems to stressful conditions, and has the highest number of four separate CRISPR/Cas loci. These features may be conducive to milk adaptation of this starter and against undesirable bacteriophage infections which leads to failure of milk fermentation. Insights into the genome of ST 1275 suggest that this strain may be a model high EPS-producing dairy starter.

Wu, Qinglong; Tun, Hein Min; Leung, Frederick Chi-Ching; Shah, Nagendra P.

2014-01-01

204

Solar photo-thermal catalytic reactions to produce high value chemicals  

SciTech Connect

This report presents a summary of the research work accomplished to date on the utilization of solar photo-thermal energy to convert low cost chemical feedstocks into high $-value chemical products. The rationale is that the solar IR-VIS-UV spectrum is unique, supplying endothermic reaction energy as well as VIS-UV for photochemical activation. Chemical market analysis and product price distribution focused attention on speciality chemicals with prices >$1.00/lb, and a synthesis sequence of n-paraffins to aromatics to partial oxidized products. The experimental work has demonstrated that enhanced reaction effects result from VIS-UV irradiation of catalytically active V2O5/SiO2. Experiments of the past year have been on dehydrogenation and dehydrocyclization of n-paraffins to olefins and aromatics with preference for the latter. Recent results using n-hexane produced 95% conversion with 56% benzene; it is speculated that aromatic yield should reach {approximately}70% by further optimization. Pilot- and commercial-scale reactor configurations have been examined; the odds-on-favorite being a shallow fluid-bed of catalyst with incident radiation from the top. Sequencing for maximum cost effectiveness would be day-time endothermic followed by night-time exothermic reactions to produce the products.

Prengle, H.W. Jr.; Wentworth, W.E. [Houston Univ., TX (United States)] [Houston Univ., TX (United States)

1992-04-01

205

Genomic insights into high exopolysaccharide-producing dairy starter bacterium Streptococcus thermophilus ASCC 1275.  

PubMed

Streptococcus thermophilus ASCC 1275 (ST 1275), a typical dairy starter bacterium, yields the highest known amount (~1,000?mg/L) of exopolysaccharide (EPS) in milk among the species of S. thermophilus. The addition of this starter in milk fermentation exhibited texture modifying properties for fermented dairy foods such as yogurt and cheese in the presence of EPS as its important metabolite. In this genomic study, a novel eps gene cluster for EPS assembly of repeating unit has been reported. It contains two-pair epsC-epsD genes which are assigned to determine the chain length of EPS. This also suggests this organism produces two types of EPSs - capsular and ropy EPS, as observed in our previous studies. Additionally, ST 1275 appears to exhibit effective proteolysis system and sophisticated stress response systems to stressful conditions, and has the highest number of four separate CRISPR/Cas loci. These features may be conducive to milk adaptation of this starter and against undesirable bacteriophage infections which leads to failure of milk fermentation. Insights into the genome of ST 1275 suggest that this strain may be a model high EPS-producing dairy starter. PMID:24827399

Wu, Qinglong; Tun, Hein Min; Leung, Frederick Chi-Ching; Shah, Nagendra P

2014-01-01

206

Fast Magnetic Reconnection in High-Energy-Density Laser-Produced Plasmas  

NASA Astrophysics Data System (ADS)

Recent experiments have observed magnetic reconnection in high-energy-density, laser-produced plasma bubbles [1,2], with reconnection rates observed to be much higher than can be explained by classical theory. This is a novel regime for magnetic reconnection study, characterized by extremely high magnetic fields, high plasma beta and strong, supersonic plasma inflow. Reconnection in this regime is investigated with particle-in-cell simulations. Collisionless simulations have identified two key ingredients, simultaneously present for the first time: two-fluid reconnection mediated by collisionless effects (that is, the Hall current and electron pressure tensor), and strong flux pile-up of the inflowing magnetic field [3]. These effects combine to yield reconnection rates independent of the nominal Alfvén speed (based on the magnetic field before interaction), and simply given by the dynamic time L/V, in qualitative agreement with the experiments. We present detailed simulations spanning the parameter ranges of the experiments, and further compare the results of simulations with and without binary collisions, in 2D and 3D. Finally we discuss plans for future laser-driven reconnection experiments.[4pt] [1] P. M. Nilson, et al, Phys. Rev. Lett. 97, 255001 (2006).[0pt] [2] C. K. Li, et al, Phys. Rev. Lett. 99, 055001 (2007).[0pt] [3] W. Fox, A. Bhattacharjee, K. Germaschewski, Phys. Rev. Lett. 106, 215003 (2011).

Fox, William

2011-11-01

207

3-D simulations of magnetic reconnection in high-energy-density laser-produced plasmas  

NASA Astrophysics Data System (ADS)

Magnetic reconnection has recently been observed and studied in high-energy-density, laser-produced plasmas, in a regime characterized by extremely high magnetic fields, high plasma beta and strong, supersonic plasma inflow. These experiments are interesting both for obtaining fundamental data on reconnection, and may also be relevant for inertial fusion, as this magnetic reconnection geometry, with multiple, colliding, magnetized plasma bubbles occurs naturally inside ICF hohlraums. Previous 2-d particle-in-cell reconnection simulations, with parameters and geometry relevant to the experiments, identified key ingredients for obtaining the very fast reconnection rates, namely two-fluid reconnection mediated by collisionless effects (the Hall current and electron pressure tensor), and strong flux pile-up of the inflowing magnetic field [1]. We present results from extending the previous simulations to 3-d, and discuss 3-d effects in the experiments, including instabilities in the reconnection layer, the topological skeleton of null-null lines, and field-generation from the Biermann battery effect. [4pt] [1] W. Fox, A. Bhattacharjee, and K. Germaschewski, PRL 106, 215003 (2011).

Fox, W.; Bhattacharjee, A.; Germaschewski, K.

2012-10-01

208

Tribological properties of carbon coatings produced by high temperature chlorination of silicon carbide.  

SciTech Connect

The tribological properties of highly disordered graphitic carbon layers formed on silicon carbide (SiC) substrates by reaction with chlorine and chlorine-hydrogen gas mixtures at 1000 {sup o}C were studied. Si was selectively removed from the near surface of SiC by chlorine gas, leaving behind a layer of carbon having high structural density and strong bonding characteristics. Tribological tests showed that the carbon films were highly adherent and able to reduce friction coefficients of the base SiC by factors of up to seven. There was little or no change in the factional behavior of carbon layers when sliding velocity and load were increased. Low friction coefficients (-0.1) could be obtained under wet, dry, polished, and rough conditions. The initially rough carbon surface underwent plastic flow producing a smooth, self-adjusting carbon layer. Structural morphology and the amount of disorder in the carbon layers were correlated with the friction and wear performance of the resultant films.

Ersoy, D. A.; McNallan, M. J.; Gogotsi, Y.; Erdemir, A.; Univ. of Illinois at Chicago; Drexel Univ.

2000-01-01

209

ROSE.C—a program in ``C'' for producing high-quality rose diagrams  

NASA Astrophysics Data System (ADS)

ROSE.C is a program written in "C" to draw Rose diagrams of high quality using 24-pin dot-matrix printers. It can handle both unidirectional and bidirectional (axial) data, and also compute and print various statistical parameters such as the direction of the resultant, the circular variance, consistency ratio, and the mean angular deviation. The diagrams produced can be scaled up to a maximum size of 9.3 cm. A number of options, including a selection of nine different patterns to shade the Rose diagram, have been provided. One of them allows the user to control the pattern. The program is designed to run up to 20 datafiles in a batch, each with its own options.

Kutty, T. S.; Ghosh, Parthasarathi

1992-10-01

210

Micro-cone targets for producing high energy and low divergence particle beams  

DOEpatents

The present invention relates to micro-cone targets for producing high energy and low divergence particle beams. In one embodiment, the micro-cone target includes a substantially cone-shaped body including an outer surface, an inner surface, a generally flat and round, open-ended base, and a tip defining an apex. The cone-shaped body tapers along its length from the generally flat and round, open-ended base to the tip defining the apex. In addition, the outer surface and the inner surface connect the base to the tip, and the tip curves inwardly to define an outer surface that is concave, which is bounded by a rim formed at a juncture where the outer surface meets the tip.

Le Galloudec, Nathalie

2013-09-10

211

Isolation of New Aureobasidium Strains That Produce High-Molecular-Weight Pullulan with Reduced Pigmentation  

PubMed Central

New isolates of Aureobasidium pullulans were obtained from plant leaf surfaces gathered in San Diego County. The new fungal isolates were identified as A. pullulans on the basis of the appearance of polymorphic colonies formed on agar plates, the electrophoretic profiles of repeated genomic DNA sequences, and the production of pullulan in shake flask cultures. The isolates showed different degrees of pigmentation. One of the natural isolates was nonpigmented under mock production conditions in liquid culture, but was still able to synthesize a reduced amount of pigment on agar plates at late times. A mutagenic treatment with ethidium bromide produced derivatives of normally pigmented natural isolates that exhibited an increased tendency toward yeastlike growth and reduced pigmentation. Additionally, some of the new isolates and mutant derivatives accumulated pullulan of relatively high molecular weight in the culture broths. Images

Pollock, Thomas J.; Thorne, Linda; Armentrout, Richard W.

1992-01-01

212

On the highly directional expansion of laser-produced plasmas. [metallic targets  

NASA Technical Reports Server (NTRS)

The expansion of plasmas produced by focusing a CO2 laser pulse onto solid planar targets is discussed. The plasmas are studied using an extreme-ultraviolet spectroheliograph. With titanium and iron targets the plasma blow-off observed in transitions within highly ionized species (e.g., Fe XVI) occurs parallel to the target normal. The plasma is tightly confined to narrow cylindrical structures about 0.7 mm in diameter and is observed as far as 1 cm from the target surface. The electron density is about 2.8 by 10 to the 18th power per cu cm at a distance of 0.7 mm from the target surface and decreases to approximately 6.5 by 10 to the 17th power per cu cm at a distance of 2.9 mm from the surface.

Doschek, G. A.; Feldman, U.; Burkhalter, P. G.; Finn, T.; Feibelman, W. A.

1977-01-01

213

Testing Different Materials to Produce Gas Gaps in High Rate RPCs  

NASA Astrophysics Data System (ADS)

The PHENIX experiment at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory uses polarized proton-proton collisions to study the spin of the proton. This study is made by reconstructing muons produced in the proton collisions. As RHIC moves to higher energies, the existing trigger is not sufficient to select the events of interest such as single high pT muons that are a result of W-Boson production. To aid the current muon triggering system, fast Resistive Plate Chambers made from Italian Bakelite are being added to the detector system. At the University of Illinois Urbana-Champaign, a test stand has been built to help understand different factors that affect the RPCs performance and rate capabilities. The test stand uses open gas gap RPCs which are ideal for testing different materials and their rate capabilities of these different materials. Various materials and their data will be presented.

Wright, Ryan

2008-10-01

214

Interlocking of ?-carotene in beta-lactoglobulin aggregates produced under high pressure.  

PubMed

Vitamin A deficiency is one of the major causes of mortality and morbidity in the developing World. This deficiency can be prevented by alimentary or pharmaceutical supplementation. However, both vitamin A oxidation and isomerization should be prevented, as these phenomenons result in loss of nutritional efficacy. The aim of this study was to investigate the effect of a food protein matrix, ?-lactoglobulin (?-Lg) aggregates produced by high pressure (HP), on the stabilization of ?-carotene during storage and gastro-duodenal digestion and therefore on its bioavailability. In vitro gastro-duodenal digestion of ?-Lg aggregates entrapping ?-carotene showed that up to 12% and 33% of total ?-carotene was released after peptic and pancreatic digestion, respectively. Overall, our study showed that ?-Lg aggregates are efficient for caging and stabilization of ?-carotene during storage and digestion. Hence, it may be an interesting approach for the protection and the delivery of vitamin A. PMID:23561103

Mensi, Azza; Choiset, Yvan; Haertlé, Thomas; Reboul, Emmanuelle; Borel, Patrick; Guyon, Claire; de Lamballerie, Marie; Chobert, Jean-Marc

2013-08-15

215

Producing pure gas of high calorific value from gasification of solid fuel  

SciTech Connect

A process is described for producing and then using a gas of high calorific value and low dust content comprising contacting a solid fuel with water vapor and free oxygen in a gasification reactor at a pressure of about 5 to 150 bars and a temperature sufficient to produce a gas containing hydrogen and carbon monoxide, containing at least about 8 grams of dust per standard cubic meter and having a temperature of about 350 to 800/sup 0/C, subjecting the gas to a dry coarse purification to reduce the solids content thereof, intensely scrubbing the gas at about 150 to 350/sup 0/C with a scrubbing liquid predominantly comprising hydrocarbons and including less than 2% of water by weight, after said dry coarse purification and before said scrubbing spraying water into the gas thereby to cool it to below 350/sup 0/C so as to prevent cracking of constituents of said scrubbing liquid, at least about 70% of said hyudrocarbons of the scrubbing liquid having a boiling point abouve about 350/sup 0/C, said scrubbing liquid being supplied to the scrubbing stage at a rate of about 0.5 to 6 liters per standard cubic meter of raw gas, withdrawing a purified gas with a solids content not exceeding 10 milligrams per standard cubic meter and having an enchanced calorific value and employing it as a fuel for the operation of at least one turbine, withdrawing used scrubbing liquid from said intense scrubbing stage and cooling it by indirect heat exchange in a cooling zone, separating the liquid from said cooling zone in a tar separator into a high-solids heavy phase and a low solids lighter phase, and using said lighter phase as said scrubbing liquid in the intense scrubbing stage.

Bierbach, H.; Hafke, C.; Kohlen, R.

1980-07-08

216

Precipitation-strengthened high-strength, high-conductivity Cu-Cr-Nb alloys produced by chill blockmelt spinning  

SciTech Connect

There are many potential applications for materials that possess a combination of high strength, high conductivity, and good long term stability at elevated temperatures. In an effort to achieve this combination of properties a series of Cu-based alloys containing 2 to 10 a/o Cr and 1 to 5 a/o Nb were produced by chill block melt spinning (CBMS). The melt spun ribbons were consolidated and hot rolled to sheet for testing. The desire was to produce a supersaturated Cu-Cr-Nb solid solution from which the high melting point intermetallic compound Cr{sub 2}Nb could be preferentially precipitated to precipitation strengthen the Cu matrix. By using the intermetallic phase, it was hoped that the precipitates would not coarsen readily and lose their strength as Cu-Cr alloys do when exposed to elevated temperatures, particularly above 500{degree}C. The results show that the materials possess electrical conductivities in excess of 90% that of pure Cu at 200{degree}C and above. This implies that the thermal conductivities of these alloys are near that of pure Cu at temperatures above 200{degree}C. The strengths of the Cu-Cr-Nb alloys were much greater than Cu, Cu-0.6 Cr, NARloy-A, and NARloy-Z in the as-melt spun condition. The strengths of the consolidated materials were less than Cu-Cr and Cu-Cr-Zr below 500{degree}C and 600{degree}C respectively, but were significantly better above these temperatures. The strengths of the consolidated materials were greater than conventional wrought NARloy-Z, the material currently used in rocket nozzles, at all temperatures. GLIDCOP possessed similar strength levels up to 750{degree}C when the strength of the Cu-Cr-Nb alloys begins to degrade.

Ellis, D.L.

1989-01-01

217

An ex vivo imaging pipeline for producing high-quality and high-resolution diffusion-weighted imaging datasets.  

PubMed

Diffusion tensor (DT) imaging and related multifiber reconstruction algorithms allow the study of in vivo microstructure and, by means of tractography, structural connectivity. Although reconstruction algorithms are promising imaging tools, high-quality diffusion-weighted imaging (DWI) datasets for verification and validation of postprocessing and analysis methods are lacking. Clinical in vivo DWI is limited by, for example, physiological noise and low signal-to-noise ratio. Here, we performed a series of DWI measurements on postmortem pig brains, which resemble the human brain in neuroanatomical complexity, to establish an ex vivo imaging pipeline for generating high-quality DWI datasets. Perfusion fixation ensured that tissue characteristics were comparable to in vivo conditions. There were three main results: (i) heat conduction and unstable tissue mechanics accounted for time-varying artefacts in the DWI dataset, which were present for up to 15 h after positioning brain tissue in the scanner; (ii) using fitted DT, q-ball, and persistent angular structure magnetic resonance imaging algorithms, any b-value between ?2,000 and ?8,000 s/mm(2) , with an optimal value around 4,000 s/mm(2) , allowed for consistent reconstruction of fiber directions; (iii) diffusivity measures in the postmortem brain tissue were stable over a 3-year period. On the basis of these results, we established an optimized ex vivo pipeline for high-quality and high-resolution DWI. The pipeline produces DWI data sets with a high level of tissue structure detail showing for example two parallel horizontal rims in the cerebral cortex and multiple rims in the hippocampus. We conclude that high-quality ex vivo DWI can be used to validate fiber reconstruction algorithms and to complement histological studies. PMID:20945352

Dyrby, Tim B; Baaré, William F C; Alexander, Daniel C; Jelsing, Jacob; Garde, Ellen; Søgaard, Lise V

2011-04-01

218

Study of intense electron beams produced by high-voltage pulsed glow discharges  

SciTech Connect

The authors report the generation of high-current-density (20 A/cm/sup 2/) pulsed electron beams from high-voltage (48-100 kV) glow discharges using cathodes 7.5 cm in diameter. The pulse duration was determined by the energy of the pulse generator and varied between 0.2 ..mu..s and several microseconds, depending on the discharge current. The largest electron beam current (900 A) was obtained with an oxidized aluminum cathode in a helium-oxygen atmosphere. An oxidized magnesium cathode produced similar results, and a molybdenum cathode operated at considerably lower currents. A small-diameter (<1 mm) well-collimated beam of energetic electrons of very high current density (>1 kA/cm/sup 2/) was also observed to develop in the center of the discharge. Electrostatic probe measurements show that the negative glow plasma density and the electron beam current have a similar spatial distribution. Electron temperatures of 1-1.5 eV were measured at 7 cm from the cathode. The plasma density (8.5 . 10/sup 11/ cm/sup -3/ at 450 A) was found to depend linearly on the discharge current. In discharges at high currents a denser and higher temperature plasma region was observed to develop at approximately 20 cm from the cathode. We have modeled the process of electron beam generation and predicted the energy distribution of the electron beam. More than 95 percent of the electron beam energy is calculated to be within 10 percent of that corresponding to the discharge voltage.

Ranea-Sandoval, H.F.; Reesor, N.; Szapiro, B.T.; Murray, C.; Rocca, J.J.

1987-08-01

219

Producing high pressure pseudotachylytes: implications for the generation of intermediate-depth earthquakes  

NASA Astrophysics Data System (ADS)

Gabbro- and peridotite-hosted blueschist facies pseudotachylytes (PST) from Cima di Gratera, Corsica, previously determined to have formed under high pressure and temperature conditions (1.8 - 2.6 GPa, 1400 °C), have been causally linked to the generation of intermediate-depth earthquakes. Detailed petrographic and microtextural analyses of these PST indicate that their initiation is controlled by a thermally activated shear runaway process that is controlled by rheology rather than mineralogy (as with dehydration embrittlement or transformational faulting), such that the rock behaves as a viscoelastic material. This is evidenced by sheared out, prolate, kinked and twinned wallrock clasts that have been peeled off and entrained into the PST vein as sigmoids. The presence of gouge and wallrock grains that have undergone crystal plastic behaviour that increases towards PST are suggestive of a high temperature shear localization mechanism. The presence of metastable high temperature crystallisation products from the PST such as hoppers and dendrites of olivine (Mg# 84), enstatite and diopside (peridotite), and Al-rich omphacite and Fe-rich anorthite (gabbro) support the hypothesis of a short-lived high temperature event resulting from thermal runaway. Overprinting of these high temperature mineral assemblages by ones indicating lower temperatures, but still high pressures, such as glaucophane, albite and epidote (gabbro) and clinochore, fine-grained granoblastic olivine, enstatite and diopside (peridotite) are further support of this. The detailed study of two different lithologies (peridotite and gabbro) that were exposed to similarly high PST-producing P-T conditions are used to corroborate the proposed runaway process. This work provides the first detailed observations from natural samples indicating that intermediate-depth seismicity may be generated by thermal runaway. Detailed microprobe analyses and BSE imaging of the PST vein matrix (comprising glass, the crystallisation products and entrained wallrock material) show that the PST melt ranges in water content from 0 - 14 wt%. This water is derived internally within the shear system due to the wholesale fusion of hydrous wallrock minerals (glaucophane, tremolite, clinochlore and serpentine) rather than dehydration. These observations, together with the microtextures, preclude local dehydration embrittlement, transformational faulting and purely ductile models such as self-localizing runaway (as proposed by Kelemen and Hirth, 2007 and John et al., 2009) as sources of intermediate-depth seismicity.

Deseta, Natalie; Ashwal, Lewis; Andersen, Torgeir

2013-04-01

220

[Evaluation of micturitional disturbance in spinal disorders: reproducibility of uroflowmetry].  

PubMed

Patients with spinal degenerative diseases suffer not only neuropathy in the extremities but also lower urinary tract dysfunction(LUTD). Patients with cauda equina syndrome generally need emergency decompression to pelvic visceral function, especially that of the urinary bladder. However, less prominent voiding symptoms can be missed in clinical settings. There is a discrepancy between lower urinary tract symptoms and LUTD. Therefore, urodynamic studies are needed to screen of patients with spinal diseases. Cystometry and urethral sphincter electromyography are useful for increasing our understanding of LUTD but are too invasive for screening. Our protocol for the evaluation of LUTD consists of residual urine measurement and uroflowmetry(UFM). UFM is the simplest and noninvasive urodynamic technique;however, it has the disadvantage of being nonreproducible, which depends on bladder volume, diurnal variation, presence of obstructive disease, and mental stress. UFM was reportedly reproducible in normal individuals in 1979, but was not evaluated in patients with spinal disease. This study examined the reproducibility of UFM in patients with spinal disease. UFM was performed twice in 26 male patients with cervical or lumbar degenerative disease. Maximum urinary flow rate corrected with Siroky's nomogram was reproducible in 23(88.5%)of the 26 patients. A urinary flow curve was reproducible in 25(96.2%)of the 26 patients, and only 1 patient had excessive urination at the 1st UFM and normal urination at the 2nd UFM. The reproducibility of UFM was high in patients with spinal degenerative disease. PMID:24388936

Kuraishi, Keita; Hanakita, Junya; Takahashi, Toshiyuki; Watanabe, Mizuki; Uesaka, Toshio; Honda, Fumiaki; Minami, Manabu; Ueno, Manabu

2014-01-01

221

Wave propagation software, computational science, and reproducible research  

Microsoft Academic Search

Wave propagation algorithms are a class of high-resolution finite volume methods for solving hyperbolic partial differential equations arising in diverse applications. The development and use of the clawpack software implementing these methods serves as a case study for a more general discussion of mathematical aspects of software development and the need for more reproducibility in computational research. Sample applications discussed

Randall J. LeVeque

2006-01-01

222

Development of high-emittance scales on thoriated nickel-chromium-aluminum-base alloys. [produced by high temperature oxidation  

NASA Technical Reports Server (NTRS)

The surface regions of a DSNiCrAl alloy have been doped, by a pack diffusion process, with small amounts of Mn, Fe, or Co, and the effect of these dopants on the total normal emissivity of the scales produced by subsequent high temperature oxidation has been measured. While all three elements lead to a modest increase in emissivity, (up to 23% greater than the undoped alloy) only the change caused by manganese is thermally stable. However, this increased emissivity is within 85 percent of that of TDNiCr oxidized to form a chromia scale. The maganese-doped alloy is some 50 percent weaker than undoped DSNiCrAl after the doping treatment, and approximately 30 percent weaker after oxidation.

Seltzer, M. S.; Wright, I. G.; Wilcox, B. A.

1973-01-01

223

Enzymatic modification of high-laurate canola to produce margarine fat.  

PubMed

Stearic acid was enzymatically transesterified with high-laurate canola using a nonspecific lipase from Candida antarctica to produce structured lipids (SL) suitable for margarine application. Stearic acid levels ranged from 10 to 40 wt % of high-laurate canola oil. Differential scanning calorimetry was used to evaluate melting characteristics of the transesterified products. A stearic acid level of 30% was found to best match the melting characteristics of fat extracted from commercially available stick margarine. This SL was used to prepare nonrefrigerated and refrigerated margarine samples. Refrigerated margarine was prepared using 60% SL and 40% canola oil, whereas 100% SL was used for the nonrefrigerated margarine. Slip melting point, solid fat content, and hardness index were determined for all samples. Application of a dynamic temperature step using a dynamic stress rheometer showed complete breakdown of the commercial stick margarine and the experimental refrigerated margarine at approximately 30 degrees C and complete breakdown of the nonrefrigerated margarine at approximately 35 degrees C. Addition of canola oil to the SL improved spreadability at refrigeration temperatures and reduced the hardening effect of lauric acid in the SL. The nonrefrigerated margarine was spreadable at room temperature and exhibited no oil exudation or phase separation. PMID:11559158

Fomuso, L B; Akoh, C C

2001-09-01

224

Coupled-Multiplier Accelerator Produces High-Power Electron Beams for Industrial Applications  

SciTech Connect

The coupled multiplier is a new approach to efficient generation of MeV d.c. power for accelerator applications. High voltage is produced by a series of modules, each of which consists of a high-power alternator, step-up transformer, and 3-phase multiplier circuit. The alternators are connected mechanically along a rotating shaft, and connected by insulating flexible couplers. This approach differs from all previous d.c. technologies in that power is delivered to the various stages of the system mechanically, rather than through capacitive or inductive electrical coupling. For this reason the capital cost depends linearly on required voltage and power, rather than quadratically as with conventional technologies. The CM technology enables multiple electron beams to be driven within a common supply and insulating housing. MeV electron beam is extremely effective in decomposing organic contaminants in water. A 1 MeV, 100 kW industrial accelerator using the CM technology has been built and is being installed for treatment of wastewater at a petrochemical plant.

Hatridge, M.; McIntyre, P.; Roberson, S.; Sattarov, A.; Thomas, E.; Meitzler, Charles [Department of Physics, Texas A and M University (United States); Department of Physics, Sam Houston State University (United States)

2003-08-26

225

Use of high-boiling alcohols to produce shale oil from Green River shale  

SciTech Connect

This report describes the results of experiments in which Green River shale was treated with mono-, di-, or trifunctional alcohols in an attempt to produce high oil yields under lower pressure treatment conditions. The experiment using 1,2-ethanediol (ethylene glycol) and water resulted in a yield of 81 weight percent based on recovered liquid organic matter, a yield equivalent ro 124% of Fischer assay. The experiments using other di- and trifunctional alcohols were not successful in recovering large amounts of oil from the shale. The 1, 2-ethanediol experiments suggests that it may be possible to recover oil from shale in yields much higher than those of conventional retorting precesses at pressures well below supercritical methanol-water. Solvents with boiling points up to 200C, such as n-octanol boiling at 194C and 1,2-ethanediol boiling at 198C, can be removed from liquid product using rotary evaporation under reduced pressure. Higher-boiling alcohols such as glycerin and diethylene glycol would probably not be satisfactory solvents even if recoveries were high because of complicated separation requirements. 10 refs., 1 tab.

McKay, J.F.; Blanche, M.S.

1985-03-01

226

Producing High-Accuracy Lattice Models from Protein Atomic Coordinates Including Side Chains  

PubMed Central

Lattice models are a common abstraction used in the study of protein structure, folding, and refinement. They are advantageous because the discretisation of space can make extensive protein evaluations computationally feasible. Various approaches to the protein chain lattice fitting problem have been suggested but only a single backbone-only tool is available currently. We introduce LatFit, a new tool to produce high-accuracy lattice protein models. It generates both backbone-only and backbone-side-chain models in any user defined lattice. LatFit implements a new distance RMSD-optimisation fitting procedure in addition to the known coordinate RMSD method. We tested LatFit's accuracy and speed using a large nonredundant set of high resolution proteins (SCOP database) on three commonly used lattices: 3D cubic, face-centred cubic, and knight's walk. Fitting speed compared favourably to other methods and both backbone-only and backbone-side-chain models show low deviation from the original data (~1.5?Å RMSD in the FCC lattice). To our knowledge this represents the first comprehensive study of lattice quality for on-lattice protein models including side chains while LatFit is the only available tool for such models.

Mann, Martin; Saunders, Rhodri; Smith, Cameron; Backofen, Rolf; Deane, Charlotte M.

2012-01-01

227

Method and source for producing a high concentration of positively charged molecular hydrogen or deuterium ions  

DOEpatents

One principal object of the present invention is to provide a novel method and apparatus for generating a high concentration of H/sub 2//sup +/ or D/sub 2//sup +/ ions by using a new and improved multicusp ion source. The basic principle in achieving a high percentage of H/sub 2//sup +/ or D/sub 2//sup +/ ions is to extract them from the source as soon as they are produced. Otherwise they will react with background gas molecules to form tri-atomic ions H/sub 3//sup +/ or D/sub 3//sup +/ or be dissociated by electrons. The former reaction H/sub 2//sup +/ + H/sub 2/ ..-->.. H/sub 3//sup +/ + H can have a very short mean free path length lambda. Assuming a background neutral gas density of approximately 3.3 x 10/sup 13/ cm/sup -3/ and a cross-section sigma of approximately 6 x 10/sup -15/ cm/sup 2/, lambda = (n/sub 0/ sigma)/sup -1/ is estimated to be about 5 cm. Thus the distance traversed by the H/sub 2//sup +/ ion before it arrives at the extractor electrode cannot exceed this value. This in turn sets a limit on the length of the source chamber.

Ehlers, K.W.; Leung, K.N.

1983-07-26

228

Effect of osmotic dehydration and vacuum-frying parameters to produce high-quality mango chips.  

PubMed

Mango (Mangifera indica L.) is a fruit rich in flavor and nutritional values, which is an excellent candidate for producing chips. The objective of this study was to develop high-quality mango chips using vacuum frying. Mango ("Tommy Atkins") slices were pretreated with different maltodextrin concentrations (40, 50, and 65, w/v), osmotic dehydration times (45, 60, and 70 min), and solution temperatures (22 and 40 degrees C). Pretreated slices were vacuum fried at 120, 130, and 138 degrees C and product quality attributes (oil content, texture, color, carotenoid content) determined. The effect of frying temperatures at optimum osmotic dehydration times (65 [w/v] at 40 degrees C) was assessed. All samples were acceptable (scores > 5) to consumer panelists. The best mango chips were those pretreated with 65 (w/v) concentration for 60 min and vacuum fried at 120 degrees C. Mango chips under atmospheric frying had less carotenoid retention (32%) than those under vacuum frying (up to 65%). These results may help further optimize vacuum-frying processing of high-quality fruit-based snacks. PMID:19895464

Nunes, Yolanda; Moreira, Rosana G

2009-09-01

229

Carbapenemase-producing Enterobacteriaceae in a tertiary hospital in Madrid, Spain: high percentage of colistin resistance among VIM-1-producing Klebsiella pneumoniae ST11 isolates.  

PubMed

Here we describe the carbapenemase genes, genetic relatedness and antimicrobial susceptibility data of 123 carbapenemase-producing Enterobacteriaceae (CPE) clinical isolates recovered from 2010 to 2012, comprising Klebsiella pneumoniae (n = 79), Klebsiella oxytoca (n = 13), Serratia marcescens (n = 14), Enterobacter cloacae (n = 12), Enterobacter asburiae (n = 4) and Enterobacter aerogenes (n = 1). VIM-1 was the most common carbapenemase (n = 101) followed by KPC-2 (n = 19), OXA-48 (n = 2) and IMP-22 (n = 1). Among the K. pneumoniae isolates, nine sequence types (STs) were identified but two clones were dominant: ST11 (54/79) containing mainly VIM-1-producing isolates; and ST101 (13/79) constituted by KPC-2-producing strains. Pulsed-field gel electrophoresis (PFGE) showed a higher genetic diversity among the remaining Enterobacteriaceae. Amikacin and fosfomycin were the most active agents with 82.9% and 80.5% susceptibility, respectively. Non-susceptibility to tigecycline was detected in 36.5% of strains. Overall, colistin resistance was 24.7% and was as high as 47% in Enterobacter spp. An increase in colistin resistance from 13.5% to 31.7% was observed among K. pneumoniae isolates during the study period. Resistance was focused on ST11 since 83.3% of colistin-resistant strains belonged to this clone. The high level of colistin resistance observed in this study is worrying with respect to the already limited therapeutic options for infections caused by multidrug-resistant Gram-negative bacteria. PMID:24657043

Pena, Irene; Picazo, Juan J; Rodríguez-Avial, Carmen; Rodríguez-Avial, Iciar

2014-05-01

230

Synthesis and stability of nanocrystalline Fe alloys produced by high energy ball milling  

NASA Astrophysics Data System (ADS)

In the first portion of the study, the synthesis of a nanocrystalline Fe-B-Si alloy by mechanical alloying in a SPEX shaker mill is investigated. Electron probe microanalysis and precise lattice parameter measurements indicate that 64 hours of milling of elemental powders is insufficient to produce the complete dissolution of either Si or B in Fe, while milling to 128 hours results in dissolution of the majority of Si, but only partial dissolution of B. Second, the volume of debris incurred due to vial and ball wear is found to be large, representing 38 wt.% of the powders after 128 hours of milling. Milling of pre-alloyed Fe-7at.%B-10at.%Si powders produced by spray atomization, resulted in the precipitation of Fesb2B. This precipitation process was essentially complete after 50 hours of milling, resulting in a nanocrystalline Fe(Si) solid solution with homogeneously distributed Fesb2B precipitates. This result indicates that the extent of supersaturation which may be achieved by ball milling is not unlimited, but instead approaches a metastable equilibrium limit which is related to the equilibrium solid solubility limit. In the second segment of the study, the thermal stability of nanocrystalline Fe alloys is addressed. Nanocrystalline Fe-xAl (x = 0, 2.6 or 10 wt.%) powders are prepared using cryogenic mechanical alloying (cryomilling). The extremely low rate of diffusion of Al in Fe at the process temperature ({-}196sp°C) effectively limits dissolution of Al in the nanocrystalline alphaFe grains. Grain growth of the nanocrystalline Fe is rapid, leading to an average grain size of approximately 100 nm after 1 hour at 700sp°C. Thermal stability of the cryomilled Fe-Al materials, in contrast, is significantly higher. For example, the average grain size of cryomilled Fe-10wt.%Al is less than 20 nm after 1 hour at 700sp°C. Transmission electron microscopy demonstrates that heat treatment of the cryomilled Fe-Al materials results in a highly inhomogeneous distribution of grain size and microchemistry. The observed thermal stability is evaluated in terms of Zener pinning, solute drag and chemical ordering mechanisms. Hot isostatic pressing of the stable Fe-Al powders at 900sp°C produces compacts of greater than 99% density with an average grain size of less than 50 nm.

Perez, Robert James

231

Relevance relations for the concept of reproducibility  

PubMed Central

The concept of reproducibility is widely considered a cornerstone of scientific methodology. However, recent problems with the reproducibility of empirical results in large-scale systems and in biomedical research have cast doubts on its universal and rigid applicability beyond the so-called basic sciences. Reproducibility is a particularly difficult issue in interdisciplinary work where the results to be reproduced typically refer to different levels of description of the system considered. In such cases, it is mandatory to distinguish between more and less relevant features, attributes or observables of the system, depending on the level at which they are described. For this reason, we propose a scheme for a general ‘relation of relevance’ between the level of complexity at which a system is considered and the granularity of its description. This relation implies relevance criteria for particular selected aspects of a system and its description, which can be operationally implemented by an interlevel relation called ‘contextual emergence’. It yields a formally sound and empirically applicable procedure to translate between descriptive levels and thus construct level-specific criteria for reproducibility in an overall consistent fashion. Relevance relations merged with contextual emergence challenge the old idea of one fundamental ontology from which everything else derives. At the same time, our proposal is specific enough to resist the backlash into a relativist patchwork of unconnected model fragments.

Atmanspacher, H.; Bezzola Lambert, L.; Folkers, G.; Schubiger, P. A.

2014-01-01

232

Reproducing or Challenging Power in the Questions We Ask and the Methods We Use: A Framework for Activist Research in Urban Education  

ERIC Educational Resources Information Center

Many have argued that educational research does little to change (and may actually reproduce) the social-structural inequalities shaping the quality of high-poverty urban schools. Building from this premise, this paper asks: How can university-based scholars of urban education do research that encourages, produces, or informs change in urban…

Nygreen, Kysa

2006-01-01

233

Quantitative production of xylitol from D-xylose by a high-xylitol producing yeast mutant Candida tropicalis HXP2  

Microsoft Academic Search

Xylitol was produced as a metabolic by-product by a number of yeasts when grown on medium containing D-xylose as carbon and energy sources. Among the yeast strains tested, a mutant strain of Candida tropicalis (HXP2) was found to produce xylitol from D-xylose with a high yield (>90%). Ethanol was also produced by HXP2 when D-glucose, D-fructose, or sucrose were used

Cheng-Shung Gong; Li Fu Chen; George T. Tsao

1981-01-01

234

Energy deposition at the bone-tissue interface from nuclear fragments produced by high-energy nucleons  

NASA Technical Reports Server (NTRS)

The transport of nuclear fragmentation recoils produced by high-energy nucleons in the region of the bone-tissue interface is considered. Results for the different flux and absorbed dose for recoils produced by 1 GeV protons are presented in a bidirectional transport model. The energy deposition in marrow cavities is seen to be enhanced by recoils produced in bone. Approximate analytic formulae for absorbed dose near the interface region are also presented for a simplified range-energy model.

Cucinotta, Francis A.; Hajnal, Ferenc; Wilson, John W.

1990-01-01

235

Reproducible measurements of MPI performance characteristics.  

SciTech Connect

In this paper we describe the difficulties inherent in making accurate, reproducible measurements of message-passing performance. We describe some of the mistakes often made in attempting such measurements and the consequences of such mistakes. We describe mpptest, a suite of performance measurement programs developed at Argonne National Laboratory, that attempts to avoid such mistakes and obtain reproducible measures of MPI performance that can be useful to both MPI implementers and MPI application writers. We include a number of illustrative examples of its use.

Gropp, W.; Lusk, E.

1999-06-25

236

Real-time measurement of materials properties at high temperatures by laser produced plasmas  

NASA Technical Reports Server (NTRS)

Determination of elemental composition and thermophysical properties of materials at high temperatures, as visualized in the context of containerless materials processing in a microgravity environment, presents a variety of unusual requirements owing to the thermal hazards and interferences from electromagnetic control fields. In addition, such information is intended for process control applications and thus the measurements must be real time in nature. A new technique is described which was developed for real time, in-situ determination of the elemental composition of molten metallic alloys such as specialty steel. The technique is based on time-resolved spectroscopy of a laser produced plasma (LPP) plume resulting from the interaction of a giant laser pulse with a material target. The sensitivity and precision were demonstrated to be comparable to, or better than, the conventional methods of analysis which are applicable only to post-mortem specimens sampled from a molten metal pool. The LPP technique can be applied widely to other materials composition analysis applications. The LPP technique is extremely information rich and therefore provides opportunities for extracting other physical properties in addition to the materials composition. The case in point is that it is possible to determine thermophysical properties of the target materials at high temperatures by monitoring generation and transport of acoustic pulses as well as a number of other fluid-dynamic processes triggered by the LPP event. By manipulation of the scaling properties of the laser-matter interaction, many different kinds of flow events, ranging from shock waves to surface waves to flow induced instabilities, can be generated in a controllable manner. Time-resolved detection of these events can lead to such thermophysical quantities as volume and shear viscosities, thermal conductivity, specific heat, mass density, and others.

Kim, Yong W.

1990-01-01

237

Solar selective absorber coating for high service temperatures, produced by plasma sputtering  

NASA Astrophysics Data System (ADS)

Spectrally selective absorber coatings, deposited on engineering material substrates such as stainless steel, have been developed for service as efficient solar photothermal energy converters. The selective solar absorber is based on a multilayer of thin films, produced by sputtering. The main solar absorber is a metal/ceramic (cermet) composite, such as, Mo/Al2th or Mo/Si02, with a graded metal concentration. Such a cermet layer, strongly absorbs radiation over most of the range of the solar spectrum but is transparent to longer wavelength radiation. The cermet layer is deposited on a highly reflecting infrared metal layer. Two more layers were added: An AhO diffusion barrier layer which is deposited first on the substrate and an AI2O or a Si02 antireflection layer which is deposited on the top of the cermet film. In order to better understand the spectral reflectivity of the multilayered selective coating, a procedure for the calculation of the optical properties was developed. After the R&D development phase was successfully completed, a full scale production coating machine was constructed. The production machine is a linear in line coater. The selective coating is deposited on stainless steel tubes, translating in the coating machine while rotating about their axes, along their axial direction. Measurements of reflectance, solar absorptivity, a, thermal emissivity, C, and high temperature durability, are all parts of the quality control routine. The results show values of a in the range 0.96 - 0.98. The thermal emissivity at 350CC is in the range 0.16 - 0.18. Thermal durability tests, show no degradation of the coating when subjected to up to 65O in vacuum for one month and when passed through a temperature cycling test which includes 1200 cycles between temperatures of 150CC and 450CCfor a period of two months.

Lanxner, Michael; Elgat, Zvi

1990-08-01

238

Magnetic reconnection in high-energy-density laser-produced plasmas  

SciTech Connect

Recently, novel experiments on magnetic reconnection have been conducted in laser-produced plasmas in a high-energy-density regime. Individual plasma bubbles self-generate toroidal, mega-gauss-scale magnetic fields through the Biermann battery effect. When multiple bubbles are created at small separation, they expand into one another, driving reconnection of this field. Reconnection in the experiments was reported to be much faster than allowed by both Sweet-Parker, and even Hall-MHD theories, when normalized to the nominal magnetic fields self-generated by single bubbles. Through particle-in-cell simulations (both with and without a binary collision operator), we model the bubble interaction at parameters and geometry relevant to the experiments. This paper discusses in detail the reconnection regime of the laser-driven experiments and reports the qualitative features of simulations. We find substantial flux-pileup effects, which boost the relevant magnetic field for reconnection in the current sheet. When this is accounted for, the normalized reconnection rates are much more in line with standard two-fluid theory of reconnection. At the largest system sizes, we additionally find that the current sheet is prone to breakup into plasmoids.

Fox, W.; Bhattacharjee, A.; Germaschewski, K. [Center for Integrated Computation and Analysis of Reconnection and Turbulence, and Center for Magnetic Self-Organization in Laboratory and Astrophysical Plasmas, University of New Hampshire, Durham, New Hampshire 03824 (United States)

2012-05-15

239

Initial energy density of gluons produced in very-high-energy nuclear collisions  

PubMed

In very-high-energy nuclear collisions, the initial energy of produced gluons per unit area per unit rapidity, (dE/L2)/deta, is equal to f(g(2)&mgr;L) (g(2)&mgr;)(3)/g(2), where &mgr;(2) is proportional to the gluon density per unit area of the colliding nuclei. For an SU(2) gauge theory, a nonperturbative computation of f(g(2)&mgr;L) shows that it varies rapidly for small g(2)&mgr;L but varies only by approximately 25%, from 0.208+/-0.004 to 0.257+/-0. 005, for a wide range 35.36- 296.98 in g(2)&mgr;L. This includes the range relevant for collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). Extrapolating to SU(3), we estimate dE/deta for Au-Au collisions in the central region at RHIC and LHC. PMID:10990673

Krasnitz; Venugopalan

2000-05-01

240

Reduction of Dislocation Density in HgCdTe on Si by Producing Highly Reticulated Structures  

NASA Astrophysics Data System (ADS)

HgCdTe, because of its narrow band gap and low dark current, is the infrared detector material of choice for several military and commercial applications. CdZnTe is the substrate of choice for HgCdTe as it can be lattice matched, resulting in low-defect-density epitaxy. Being often small and not circular, layers grown on CdZnTe are difficult to process in standard semiconductor equipment. Furthermore, CdZnTe can often be very expensive. Alternative inexpensive large circular substrates, such as silicon or gallium arsenide, are needed to scale production of HgCdTe detectors. Growth of HgCdTe on these alternative substrates has its own difficulty, namely a large lattice mismatch (19% for Si and 14% for GaAs). This large mismatch results in high defect density and reduced detector performance. In this paper we discuss ways to reduce the effects of dislocations by gettering these defects to the edge of a reticulated structure. These reticulated surfaces enable stress-free regions for dislocations to glide to. In the work described herein, HgCdTe-on-Si diodes have been produced with R 0 A 0 of over 400 ? cm2 at 78 K and cutoff of 10.1 ?m. Further, these diodes have good uniformity at 78 K at both 9.3 ?m and 10.14 ?m.

Stoltz, A. J.; Benson, J. D.; Carmody, M.; Farrell, S.; Wijewarnasuriya, P. S.; Brill, G.; Jacobs, R.; Chen, Y.

2011-08-01

241

Spectroscopy of high lying resonances in 9Be produced with radioactive 8Li beams  

NASA Astrophysics Data System (ADS)

We present the results of the 8Li(p,?)5He and 8Li(p,p)8Li reactions measured at the RIBRAS (Radioactive Ion Beams in Brazil) system. The experiment was realized in inverse kinematics using a thick [CH2]n polyethylene target and an incident 8Li beam, produced by RIBRAS. Using the thick target method, the complete excitation function could be measured between Ecm = 0.2 - 2.1 MeV, which includes the Gamow peak energy region. The excitation function of the 8Li(p,?)5He reaction, populating resonances between 16.888 and 19.0 MeV in 9Be, was obtained[1] and the resonances were fitted using R-matrix calculations. This study shed light on spins, parities, partial widths and isospin values of high lying resonances in 9Be. The measurement of the resonant elastic scattering 8Li(p,p)8Li populating resonances in the same energy region can constrain the resonance parameters. Preliminary results of the elastic scattering are also presented.

Lépine-Szily, A.; Leistenschneider, E.; Mendes, D. R.; Descouvemont, P.; Lichtenthäler, R.; Guimarães, V.; de Faria, P. N.; Barioni, A.; Pires, K. C. C.; Morcelle, V.; Pampa Condori, R.; Moraes, M. C.; Scarduelli, V.; Rossi, E.; Zagatto, V. A.; Santos, H.; Aguiar, V. A. P.; Britos, T.; Assunção, M.; Zamora, J. C.; Duarte, J.; Shorto, J. M. B.

2014-04-01

242

Reproducibility of multifocal VEP latency using different stimulus presentations.  

PubMed

The aims of the article were to study the reproducibility of latency of multifocal visual evoked potential (mfVEP) recorded using different stimulus presentations and to identify the peak with least variability. Ten normal subjects, aged between 22 and 52 years (mean age 32 ± 8.37 years), participated in the study. All subjects underwent mfVEP testing with pattern reversal and pattern pulse stimulus presentations. The stimulus subtends 26° from fixation and includes 24 segments. Only the vertical channel was recorded on all subjects. Testing was repeated after 1-2 weeks. Only the right eye of all subjects was analysed. Segments with low signal-to-noise ratios (SNR < 1.5) were excluded from analysis. The latencies were analysed to confirm values from the same peak for the two tests. The latency values were then analysed for the start of the response, the first peak and the second peak. The waveforms were reproducible throughout the field. Reproducibility of latency at the "start of the response" was significantly lesser than the first and the second peaks studied, while the reproducibility of latency at the first peak was not statistically different from the second peak for either pattern reversal or pattern pulse stimulation. The latency values were not different between the first and the second sessions for either pattern reversal or pattern pulse stimulation for any of the peaks. The pattern reversal stimulus presentation produced less variability in latency. The first peak is the most reproducible among the three measures in both the stimulus presentation. PMID:22669286

Sriram, Prema; Klistorner, Alexander; Arvind, Hemamalini; Graham, Stuart L

2012-08-01

243

Reproducibility of peroneal motor nerve conduction measurement in older adults  

PubMed Central

Objective While neuropathy is common in the elderly, nerve conduction (NC) reproducibility in older adults is not well-established. We sought to evaluate intraobserver reproducibility of peroneal motor NC measures in a diverse sample of older adults. Methods We measured peroneal motor NC amplitude and velocity in a subset of participants (mean age=82.9 ± 2.7, n=62, 50% female, 51.6% black, 35.5% DM) in the Health, Aging, and Body Composition Study. Using coefficients of variation (CVs), intraclass correlation coefficients (ICCs), and Bland Altman Plots, we compared two sets of measurements taken by the same examiner hours apart on the same day. Results Low CVs (2.15–4.24%) and moderate to high ICCs (0.75–0.99) were observed. No systematic variation was found across measures. Despite small numbers in some subgroups, we found no differences in reproducibility by diabetes, race, or study site. Conclusion NC measures have moderate to high intraobsever reproducibility in older adults and are not affected by diabetes, race, or gender. Significance These data provide evidence to support use of these measures in aging research.

Ward, Rachel E.; Boudreau, Robert M.; Vinik, Aaron I.; Zivkovic, Sasa A.; Njajou, Omer T.; Satterfield, Suzanne; Harris, Tamara B.; Newman, Anne B.; Strotmeyer, Elsa S.

2012-01-01

244

Time Series of High Resolution Satellite Data as a Means to Produce and Validate Biogeophysical Parameters  

NASA Astrophysics Data System (ADS)

The retrieval of biogeophysical parameters time series from space has up to now concerned mostly low or medium resolution satellite data, the highest resolution being on the order of 250 m with MODIS or MERIS observations. However, the forthcoming of new satellite data at high resolution and high revisit frequency such as the Sentinel-2 satellite from the European Space Agency (ESA) may induce new efforts to process time series of biogeophysical variables at higher spatial resolution. Sentinel-2 will produce data at 10-20 m resolution in the visible and near infrared and data at 60 m resolution in the blue and middle infrared with a wide field of view allowing a repetitiveness of 10 days with 1 satellite and 5 days with two satellites at the Equator. The expected launch dates of the two Sentinel-2 satellites are 2014 and end of 2015. Orthorectified top of atmosphere reflectances will be delivered globally free of charge within 24 hour delay after acquisition by ESA. The Sentinel-2 data will offer great opportunities to generate time series of biogeophysical variables exhaustively over the world with high spatial resolution, in particular Essential Climate Variables over land such as the Leaf Area Index (LAI) or the Fraction of Absorbed Photosynthetically Active Radiation (FAPAR). Algorithms are currently being developed to transform such data into products ready to be used by the community. To validate the corresponding products it is important to build appropriate satellite data sets of high spatial resolution and high temporal frequencies well before launch along with the associated ground measurements. CNES, CESBIO and INRA have been active these last ten years in building such data sets. Over the last ten years, the Kalideos program of CNES has provided time series of SPOT data over 3 sites in France and 1 site in Romania to the scientific community. CESBIO has gathered over 800 Landsat images and 400 Formosat-2 images (multispectral imagery at 8 m resolution, 1 day repetitiveness) over the South of France for the years 2002, 2003, 2006 to 2011. These data have served as a platform for the test and validation of an atmospheric correction scheme based on both the multispectral and multitemporal dimensions of the signal. Their use for the validation of biophysical variable retrieval has also started. To anticipate the massive coming of these high spatial resolution time series of biophysical products, a validation strategy should be designed and implemented. It should capitalize on the experience gained with the validation of medium spatial resolution products, in order to reach stage 4 of the validation, i.e. "Quantify uncertainties in the product and its associated structure with systematic updates when new product versions are released and as the time-series expand". For this a collection of satellite data and ground data on a variety of sites and ecoclimatic situations should be progressively built with an easy and transparent access for the community. The data sets described above could be part of such a collection.

Leroy, M.; Hagolle, O.; Demarez, V.; Claverie, M.; Baret, F.

2012-12-01

245

MASSIVE DATA, THE DIGITIZATION OF SCIENCE, AND REPRODUCIBILITY OF RESULTS  

ScienceCinema

As the scientific enterprise becomes increasingly computational and data-driven, the nature of the information communicated must change. Without inclusion of the code and data with published computational results, we are engendering a credibility crisis in science. Controversies such as ClimateGate, the microarray-based drug sensitivity clinical trials under investigation at Duke University, and retractions from prominent journals due to unverified code suggest the need for greater transparency in our computational science. In this talk I argue that the scientific method be restored to (1) a focus on error control as central to scientific communication and (2) complete communication of the underlying methodology producing the results, ie. reproducibility. I outline barriers to these goals based on recent survey work (Stodden 2010), and suggest solutions such as the ?Reproducible Research Standard? (Stodden 2009), giving open licensing options designed to create an intellectual property framework for scientists consonant with longstanding scientific norms.

None

2011-10-06

246

Reproducibility of callosal effects of transcranial magnetic stimulation (TMS) with interhemispheric paired pulses.  

PubMed

Transcranial magnetic stimulation (TMS) of the motor cortex of one hemisphere (conditioning stimulus (CS)) inhibits EMG responses evoked in distal hand muscles by a later magnetic stimulus given at an appropriate interval, over the opposite hemisphere (test stimulus (TS)). This effect is commonly attributed to an inhibition produced at cortical level via a transcallosal route. The present study assessed the reproducibility of the transcallosal inhibition effects in different sessions in healthy subjects. Within- and between-subject variability, relating to interhemispheric differences was also evaluated. A magnetic CS on one hemisphere effectively inhibited EMG responses of the abductor digiti minimi stimulated by a TS delivered over the opposite hemisphere in a range of intervals centered at 12 ms. Even though group effects were reproduced in separate sessions, the high between- and within-subject variability yielded low test-retest correlations. This differentiation forces the definition of reproducibility (or repeatability), as the replication of the same mean curves of EMG reduction, and of reliability, as the between- or within-subject correlations between values of specific EMG measures. PMID:12767485

De Gennaro, Luigi; Ferrara, Michele; Bertini, Mario; Pauri, Flavia; Cristiani, Riccardo; Curcio, Giuseppe; Romei, Vincenzo; Fratello, Fabiana; Rossini, Paolo Maria

2003-06-01

247

Reproducing Groups for the Metaplectic Representation  

Microsoft Academic Search

We consider the (extended) metaplectic representation of the semidirect product G of the symplectic group and the Heisenberg group. By looking at the standard resolution of the identity formula and inspired by previous work [5], [13], [4], we introduce the notion of admissible (reproducing) subgroup of G via the Wigner distribution. We prove some features of admissible groups and then

E. Cordero; F. DE MARI; K. Nowak; A. Tabacco

248

Explicit recursivity into reproducing kernel Hilbert spaces  

Microsoft Academic Search

Thispaper presentsa methodologyto developrecursivefilters in reproducing kernel Hilbert spaces (RKHS). Unlike previous approaches that exploit the kernel trick on filtered and then mapped samples, we explicitly define model recursivity in the Hilbert space. The method exploits some properties of functionalanalysis and recursive computation of dot products without the need of pre-imaging. We illustrate the feasibility of the methodology in the

Devis Tuia; Gustavo Camps-Valls; Manel Martinez-Ramon

2011-01-01

249

Extreme ultraviolet spectra from highly charged gadolinium and neodymium ions in the Large Helical Device and laser produced plasmas  

NASA Astrophysics Data System (ADS)

We have observed extreme ultraviolet spectra from highly charged gadolinium (Gd) and neodymium (Nd) ions produced in two different types of light sources for comparative studies. Only broad quasicontinuum feature arising from unresolved transition array was observed in high-density laser produced plasmas of pure/diluted Gd and Nd targets at the University College Dublin, and the spectral feature largely depends on electron temperature in optically thin plasmas produced in the Large Helical Device at the National Institute for Fusion Science. The difference in spectral feature among a number of spectra can be qualitatively interpreted by considering dominant ion stages and opacity effects in the plasmas.

Suzuki, C.; Koike, F.; Murakami, I.; Tamura, N.; Sudo, S.; O'Gorman, C.; Li, B.; Harte, C. S.; Donnelly, T.; O'Sullivan, G.

2013-09-01

250

A high-throughput approach to identify genomic variants of bacterial metabolite producers at the single-cell level  

PubMed Central

We present a novel method for visualizing intracellular metabolite concentrations within single cells of Escherichia coli and Corynebacterium glutamicum that expedites the screening process of producers. It is based on transcription factors and we used it to isolate new L-lysine producing mutants of C. glutamicum from a large library of mutagenized cells using fluorescence-activated cell sorting (FACS). This high-throughput method fills the gap between existing high-throughput methods for mutant generation and genome analysis. The technology has diverse applications in the analysis of producer populations and screening of mutant libraries that carry mutations in plasmids or genomes.

2012-01-01

251

Reproducing the assembly of massive galaxies within the hierarchical cosmogony  

NASA Astrophysics Data System (ADS)

In order to gain insight into the physical mechanisms leading to the formation of stars and their assembly in galaxies, we compare the predictions of the MOdel for the Rise of GAlaxies aNd Active nuclei (MORGANA) to the properties of K- and 850-?m-selected galaxies (such as number counts, redshift distributions and luminosity functions) by combining MORGANA with the spectrophotometric model GRASIL. We find that it is possible to reproduce the K- and 850-?m-band data sets at the same time and with a standard Salpeter initial mass function, and ascribe this success to our improved modelling of cooling in DM haloes. We then predict that massively star-forming discs are common at z ~ 2 and dominate the star formation rate, but most of them merge with other galaxies within ~100 Myr. Our preferred model produces an overabundance of bright galaxies at z < 1; this overabundance might be connected to the build-up of the diffuse stellar component in galaxy clusters, as suggested by Monaco et al., but a naive implementation of the mechanism suggested in that paper does not produce a sufficient slowdown of the evolution of these objects. Moreover, our model overpredicts the number of 1010-1011Msolar galaxies at z ~ 1; this is a common behaviour of theoretical models as shown by Fontana et al.. These findings show that, while the overall build-up of the stellar mass is correctly reproduced by galaxy formation models, the `downsizing' trend of galaxies is not fully reproduced yet. This hints to some missing feedback mechanism in order to reproduce at the same time the formation of both the massive and the small galaxies.

Fontanot, Fabio; Monaco, Pierluigi; Silva, Laura; Grazian, Andrea

2007-12-01

252

High-energy electrons produced in subpicosecond laser-plasma interactions from subrelativistic laser intensities to relativistic intensities.  

PubMed

The characteristics of the forward hot electrons produced by subpicosecond laser-plasma interactions are studied for different laser polarizations at laser intensities from subrelativistic to relativistic. The peak of the hot electron beam produced by p-polarized laser beam shifts to the laser propagation direction from the target normal direction as the laser intensity reaches the relativistic. For s-polarized laser pulse, hot electrons are mainly directed to the laser axis direction. The temperature and the maximum energy of hot electrons are much higher than that expected by the empirical scaling law. The energy spectra of the hot electrons evolve to be a single-temperature structure at relativistic laser intensities from the two-temperature structure at subrelativistic intensities. For relativistic laser intensities, the forward hot electrons are less dependent on the laser polarization under the laser conditions. The existing of a preplasma formed by the laser amplified spontaneous emission pedestal plays an important role in the interaction. One-dimensional particle-in-cell simulations reproduce the most characteristics observed in the experiment. PMID:15089413

Li, Y T; Zhang, J; Sheng, Z M; Zheng, J; Chen, Z L; Kodama, R; Matsuoka, T; Tampo, M; Tanaka, K A; Tsutsumi, T; Yabuuchi, T

2004-03-01

253

Lactobacillus reuteri CRL 1101 highly produces mannitol from sugarcane molasses as carbon source.  

PubMed

Mannitol is a natural polyol extensively used in the food industry as low-calorie sugar being applicable for diabetic food products. We aimed to evaluate mannitol production by Lactobacillus reuteri CRL 1101 using sugarcane molasses as low-cost energy source. Mannitol formation was studied in free-pH batch cultures using 3-10% (w/v) molasses concentrations at 37 °C and 30 °C under static and agitated conditions during 48 h. L. reuteri CRL 1101 grew well in all assayed media and heterofermentatively converted glucose into lactic and acetic acids and ethanol. Fructose was used as an alternative electron acceptor and reduced it to mannitol in all media assayed. Maximum mannitol concentrations of 177.7?±?26.6 and 184.5?±?22.5 mM were found using 7.5% and 10% molasses, respectively, at 37 °C after 24-h incubation. Increasing the molasses concentration from 7.5% up to 10% (w/v) and the fermentation period up to 48 h did not significantly improve mannitol production. In agitated cultures, high mannitol values (144.8?±?39.7 mM) were attained at 8 h of fermentation as compared to static ones (5.6?±?2.9 mM), the highest mannitol concentration value (211.3?±?15.5 mM) being found after 24 h. Mannitol 2-dehydrogenase (MDH) activity was measured during growth in all fermentations assayed; the highest MDH values were obtained during the log growth phase, and no correlation between MDH activities and mannitol production was observed in the fermentations performed. L. reuteri CRL 1101 successfully produced mannitol from sugarcane molasses being a promising candidate for microbial mannitol synthesis using low-cost substrate. PMID:22350320

Ortiz, Maria Eugenia; Fornaguera, María José; Raya, Raúl R; Mozzi, Fernanda

2012-08-01

254

Batch-to-batch reproducibility of Transferon™.  

PubMed

Human dialyzable leukocyte extracts (DLEs) are heterogeneous mixtures of low-molecular-weight peptides that modulate immune responses in various diseases. Due their complexity, standardized methods to identify their physicochemical properties and determine that production batches are biologically active must be established. We aimed to develop and validate a size exclusion ultra performance chromatographic (SE-UPLC) method to characterize Transferon™, a DLE that is produced under good manufacturing practices (GMPs). We analyzed an internal human DLE standard and 10 representative batches of Transferon™, all of which had a chromatographic profile characterized by 8 main peaks and a molecular weight range between 17.0 and 0.2kDa. There was high homogeneity between batches with regard to retention times and area percentages, varying by less than 0.2% and 30%, respectively, and the control chart was within 3 standard deviations. To analyze the biological activity of the batches, we studied the ability of Transferon™ to stimulate IFN-? production in vitro. Transferon™ consistently induced IFN-? production in Jurkat cells, demonstrating that this method can be included as a quality control step in releasing Transferon™ batches. Because all analyzed batches complied with the quality attributes that were evaluated, we conclude that the DLE Transferon™ is produced with high homogeneity. PMID:24099727

Medina-Rivero, Emilio; Merchand-Reyes, Giovanna; Pavón, Lenin; Vázquez-Leyva, Said; Pérez-Sánchez, Gilberto; Salinas-Jazmín, Nohemí; Estrada-Parra, Sergio; Velasco-Velázquez, Marco; Pérez-Tapia, Sonia Mayra

2014-01-01

255

Precipitation Strengthened High Strength, High Conductivity Cu-Cr-Nb Alloys Produced by Chill Block Melt Spinning.  

National Technical Information Service (NTIS)

A series of Cu-based alloys containing 2 to 10 a/o Cr and 1 to 5 a/o Nb were produced by chill block melt spinning (CBMS). The melt spun ribbons were consolidated and hot rolled to sheet to produce a supersaturated Cu-Cr-Nb solid solution from which the h...

D. L. Ellis G. M. Michal

1989-01-01

256

Frozen tissue can provide reproducible proteomic results of subcellular fractionation.  

PubMed

Differential detergent fractionation (DDF) is frequently used to partition fresh cells and tissues into distinct compartments. We have tested whether DDF can reproducibly extract and fractionate cellular protein components from frozen tissues. Frozen kidneys were sequentially extracted with three different buffer systems. Analysis of the three fractions with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified 1693 proteins, some of which were common to all fractions and others of which were unique to specific fractions. Normalized spectral index (SI(N)) values obtained from these data were compared to evaluate both the reproducibility of the method and the efficiency of enrichment. SI(N) values between replicate fractions demonstrated a high correlation, confirming the reproducibility of the method. Correlation coefficients across the three fractions were significantly lower than those for the replicates, supporting the capability of DDF to differentially fractionate proteins into separate compartments. Subcellular annotation of the proteins identified in each fraction demonstrated a significant enrichment of cytoplasmic, cell membrane, and nuclear proteins in the three respective buffer system fractions. We conclude that DDF can be applied to frozen tissue to generate reproducible proteome coverage discriminating subcellular compartments. This demonstrates the feasibility of analyzing cellular compartment-specific proteins in archived tissue samples with the simple DDF method. PMID:21802400

Lim, Jihyeon; Menon, Vilas; Bitzer, Markus; Miller, Leah M; Madrid-Aliste, Carlos; Weiss, Louis M; Fiser, Andras; Angeletti, Ruth H

2011-11-01

257

Use of palm oil fuel ash as a supplementary cementitious material for producing high-strength concrete  

Microsoft Academic Search

The objective of this study is to investigate the use of ground palm oil fuel ash with high fineness (GPA) as a pozzolanic material to produce high-strength concrete. Samples were made by replacing Type I Portland cement with various proportions of GPA. Properties such as the compressive strength, drying shrinkage, water permeability, and sulfate resistance, were then investigated. After aging

Weerachart Tangchirapat; Chai Jaturapitakkul; Prinya Chindaprasirt

2009-01-01

258

Producing ultrashort Terahertz to UV photons at high repetition rates for research into materials  

SciTech Connect

A new THz/IR/UV photon source at Jefferson Lab is the first of a new generation of light sources based on a Energy-Recovered, (superconducting) Linac (ERL). The machine has a 160 MeV electron beam and an average current of 10 mA in 75 MHz repetition rate hundred femtosecond bunches. These electron bunches pass through a magnetic chicane and therefore emit synchrotron radiation. For wavelengths longer than the electron bunch the electrons radiate coherently a broadband THz {approx} half cycle pulse whose average brightness is > 5 orders of magnitude higher than synchrotron IR sources. Previous measurements showed 20 W of average power extracted[1]. The new facility offers simultaneous synchrotron light from the visible through the FIR along with broadband THz production of 100 fs pulses with >200 W of average power (see G. P. Williams, this conference). The FELs also provide record-breaking laser power [2]: up to 10 kW of average power in the IR from 1 to 14 microns in 400 fs pulses at up to 74.85 MHz repetition rates and soon will produce similar pulses of 300-1000 nm light at up to 3 kW of average power from the UV FEL. These ultrashort pulses are ideal for maximizing the interaction with material surfaces. The optical beams are Gaussian with nearly perfect beam quality. See www.jlab.org/FEL for details of the operating characteristics; a wide variety of pulse train configurations are feasible from 10 microseconds long at high repetition rates to continuous operation. The THz and IR system has been commissioned. The UV system is to follow in 2005. The light is transported to user laboratories for basic and applied research. Additional lasers synchronized to the FEL are also available. Past activities have included production of carbon nanotubes, studies of vibrational relaxation of interstitial hydrogen in silicon, pulsed laser vapor deposition, nitriding of metals, and energy flow in proteins. This paper will present the status of the system and discuss some of the opportunities provided by this unique light source for modifying and studying materials.

G. R. Neil; C. Behre; S. V. Benson; G. Biallas; J. Boyce; L.A. Dillon-Townes; D. Douglas; H. F. Dylla; R. Evans; A. Grippo; D. Gruber; J. Gubeli; C. Hernandez-Garcia; K. Jordan; M. J. Kelley; L. Merminga; J. Mammosser; N. Nishimori; J. Preble; R. Rimmer; Michelle D. Shinn; T. Siggins; R. Walker; G. P. Williams; and S. Zhang

2005-11-01

259

A meshfree unification: reproducing kernel peridynamics  

NASA Astrophysics Data System (ADS)

This paper is the first investigation establishing the link between the meshfree state-based peridynamics method and other meshfree methods, in particular with the moving least squares reproducing kernel particle method (RKPM). It is concluded that the discretization of state-based peridynamics leads directly to an approximation of the derivatives that can be obtained from RKPM. However, state-based peridynamics obtains the same result at a significantly lower computational cost which motivates its use in large-scale computations. In light of the findings of this study, an update to the method is proposed such that the limitations regarding application of boundary conditions and the use of non-uniform grids are corrected by using the reproducing kernel approximation.

Bessa, M. A.; Foster, J. T.; Belytschko, T.; Liu, Wing Kam

2014-06-01

260

Technique for increasing reproducibility in EPR dosimetry of tooth enamel  

NASA Astrophysics Data System (ADS)

Variations in several electron paramagnetic resonance (EPR) spectral parameters of importance in retrospective dosimetry of tooth enamel were measured using instrumentation and methodologies designed to maximize measurement reproducibility. Measurements were made using accessory EPR equipment that can be readily constructed with little more than a variable power supply, a geared down motor and some high-purity CaO. Spectroscopic precision is considerably enhanced due to elimination of sample anisotropies by scanning samples throughout their angular range. Frequency drifting incurred by sample reorientation and instrument/sample warm-up is effectively eliminated using an in-cavity 0957-0233/9/12/011/img7:CaO standard. This work shows that for highly anisotropic samples, spectral characteristic parameters (peak-to-peak amplitudes, signal component widths and positions) are reproduced with equal or comparable precision to the case where standard EPR configurations are used while measuring approximately isotropic samples.

Hayes, R. B.; Haskell, E. H.; Romanyukha, A. A.; Kenner, G. H.

1998-12-01

261

Reproducibility of PMR-15 graphite polymide material  

NASA Technical Reports Server (NTRS)

Investigation was made into the reproducibility of PMR polyimide/graphite prepreg reinforcement and the influence of these variabilities on processing characteristics and final composite properties. The purpose of these investigations was to establish specification controls and limits of acceptance/rejection on incoming materials. Prepreg samples were chemically analyzed and the results compared to the processing and property results of the resulting composites. The findings from these comparisons are discussed.

Hoggatt, J. T.; Hunter, A. B.; Sheppard, C. H.

1978-01-01

262

Independence and reproducibility across microarray platforms  

Microsoft Academic Search

Microarrays have been widely used for the analysis of gene expression, but the issue of reproducibility across platforms has yet to be fully resolved. To address this apparent problem, we compared gene expression between two microarray platforms: the short oligonucleotide AffymetrixMouse Genome 430 2.0 GeneChip and a spotted cDNA array using a mouse model of angiontensin II–induced hypertension. RNA extracted

Jennie E. Larkin; Bryan C. Frank; Haralambos Gavras; Razvan Sultana; John Quackenbush

2005-01-01

263

Reproducibility of liquid oxygen impact test results  

NASA Technical Reports Server (NTRS)

Results for 12,000 impacts on a wide range of materials were studied to determine the reproducibility of the liquid oxygen impact test method. Standard deviations representing the overall variability of results were in close agreement with the expected values for a binomial process. This indicates that the major source of variability is due to the go - no go nature of the test method and that variations due to sampling and testing operations were not significant.

Gayle, J. B.

1975-01-01

264

Enhanced Dynamic Documents for Reproducible Research  

Microsoft Academic Search

\\u000a Dynamic documents that combine text and code, which is evaluated to dynamically create content when the document is “rendered,”\\u000a for example, Sweave, are a large step forward in reproducible data analysis and computation. However, to capture the research\\u000a process, we need richer paradigms and infrastructure. The process includes all the investigations and computations, and not just\\u000a the final reported ones,

Deborah Nolan; Roger D. Peng; Duncan Temple Lang

265

Dosimetric Algorithm to Reproduce Isodose Curves Obtained from a LINAC  

PubMed Central

In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18?MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18?MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo.

Estrada Espinosa, Julio Cesar; Martinez Ovalle, Segundo Agustin; Pereira Benavides, Cinthia Kotzian

2014-01-01

266

Induction of reproducible brain infarction by photochemically initiated thrombosis.  

PubMed

We have used a photochemical reaction in vivo to induce reproducible thrombosis leading to cerebral infarction in rats. After the intravenous injection of rose bengal, a potent photosensitizing dye, an ischemic lesion was formed by irradiating the left parietal convexity of the exposed skull for 20 minutes with green light (560 nm) from a filtered xenon arc lamp. Animals were allowed to survive from 30 minutes to 15 days after irradiation. Early microscopic alterations within the irradiated zone included the formation of thrombotic plugs and adjacent red blood cell stasis within pial and parenchymal vessels. Scanning electron microscopy revealed frequent platelet aggregates adhering to the vascular endothelium, often resulting in vascular occlusion. Carbon-black brain perfusion demonstrated that occlusion of vascular channels progressed after irradiation and was complete within 4 hours. Histopathological examination at 1, 5, and 15 days revealed that the associated infarct evolved reproducibly through several characteristic stages, including a phase of massive macrophage infiltration. Although cerebral infarction in this model is initiated by thrombosis of small blood vessels, the fact that the main pathological features of stroke are consistently reproduced should permit its use in assessing treatment regimens. Further, the capability of producing infarction in preselected cortical regions may facilitate the study of behavioral, functional, and structural consequences of acute and chronic stroke. PMID:4004172

Watson, B D; Dietrich, W D; Busto, R; Wachtel, M S; Ginsberg, M D

1985-05-01

267

Dosimetric Algorithm to Reproduce Isodose Curves Obtained from a LINAC.  

PubMed

In this work isodose curves are obtained by the use of a new dosimetric algorithm using numerical data from percentage depth dose (PDD) and the maximum absorbed dose profile, calculated by Monte Carlo in a 18?MV LINAC. The software allows reproducing the absorbed dose percentage in the whole irradiated volume quickly and with a good approximation. To validate results an 18?MV LINAC with a whole geometry and a water phantom were constructed. On this construction, the distinct simulations were processed by the MCNPX code and then obtained the PDD and profiles for the whole depths of the radiation beam. The results data were used by the code to produce the dose percentages in any point of the irradiated volume. The absorbed dose for any voxel's size was also reproduced at any point of the irradiated volume, even when the voxels are considered to be of a pixel's size. The dosimetric algorithm is able to reproduce the absorbed dose induced by a radiation beam over a water phantom, considering PDD and profiles, whose maximum percent value is in the build-up region. Calculation time for the algorithm is only a few seconds, compared with the days taken when it is carried out by Monte Carlo. PMID:25045398

Estrada Espinosa, Julio Cesar; Martínez Ovalle, Segundo Agustín; Pereira Benavides, Cinthia Kotzian

2014-01-01

268

Reproducibility of quantitative two-dimensional echocardiography.  

PubMed

In order to assess reproducibility of quantitative planimetry, three physicians trained in two-dimensional echocardiography performed five successive studies on one another over 2 weeks (30 total studies). Then each physician traced each study (90 total tracings) for left ventricular and atrial volumes and ejection fraction by means of a modification of Simpson's rule, and left ventricular mass and average wall thickness by means of a truncated ellipsoid formula. Calculation of intertechnician variability, intertracer variability, and 95% confidence limits showed that measurements of volumes were less reproducible than measurements of ejection fraction, average wall thickness, and mass. Mean intertracer variability of 15% exceeded mean intertechnician variability of 11%; this disparity was magnified in the subject who was technically difficult to image. Ninety-five percent confidence limits were: ejection fraction +/- 7%, average wall thickness +/- 9%, left ventricular mass +/- 12%, left ventricular end-diastolic volume +/- 11%, stroke volume +/- 14%, left ventricular end-systolic volume +/- 15%, and left atrial volume +/- 19%. Reproducible planimetry data can be obtained in normal hearts with the use of a protocol for quantitative imaging and planimetry. PMID:3341178

Himelman, R B; Cassidy, M M; Landzberg, J S; Schiller, N B

1988-02-01

269

Development of a high-power neutron-producing lithium target for boron neutron capture therapy  

Microsoft Academic Search

A neutron producing lithium target for a novel, accelerator based cancer treatment requires the removal of up to 6kW of heat produced by 1-2mA beam of 2.3-3.0MeV protons. This paper presents the results form computer simulations which show that, using submerged jet cooling, a solid lithium target can be maintained up to 1.6mA, and a liquid target up to 2.6mA,

Adam V. Brown; Malcolm C. Scott

2000-01-01

270

Measurements of Secondary Neutrons Produced from Thick Targets Bombarded by High Energy Neon Ions  

Microsoft Academic Search

Following our preceding study on thick target neutron yields by He and C, we measured angular and energy distributions of neutrons produced by 100, 180 and 400 MeV\\/nucleon Ne ions stopping in thick carbon, aluminum, copper and lead targets using the heavy ion medical accelerator of the National Institute of Radiological Sciences. The neutron spectra in the forward direction have

Tadahiro KUROSAWA; Noriaki NAKAO; Takashi NAKAMURA; Yoshitomo UWAMINO; Tokushi SHIBATA; Akifumi FUKUMURA; Ken MURAKAMI

1999-01-01

271

Ultra-high temperature chirped fiber Bragg gratings produced by gradient stretching of viscoelastic silica.  

PubMed

By applying a suitable quadratic temperature distribution at a temperature within the viscoelastic softening region for silica, a regenerated chirped grating with bandwidth of 9.8 nm is produced from a uniform grating using post strain-tuning under load. Simulated and experimental results are in good agreement. PMID:24322267

Gao, Shaorui; Canning, John; Cook, Kevin

2013-12-15

272

Instabilities of a Gyroscope Produced by Rapidly Rotating, Highly Viscous Liquids.  

National Technical Information Service (NTIS)

A series of experiments were conducted to determine the yaw behavior of a gyroscope that contained a liquid-filled rotor. Spin rates, liquid viscosities, and cylinder geometries were selected to produce a wide range of Reynolds numbers (5 < RE < 12,000). ...

W. P. D'Amico

1983-01-01

273

A highly integrated, mass produced battery module as basis for various EV and HEV systems  

Microsoft Academic Search

The battery system is the key component in a full electric or a plug-in electric vehicle. Important aspects are cost, package, safety, performance and durability. With a modular design the fundamental requirements can be fulfilled at a sub-level. Providing easy and appropriate interfaces all special issues can be solved efficient on system level. Such a module can be mass produced

B. Eberleh; F. von Borck; S. Raiser

2010-01-01

274

High prevalence of faecal carriage of ESBL-producing Enterobacteriaceae in Norwegian patients with gastroenteritis.  

PubMed

We conducted a cross-sectional study to examine the prevalence of faecal carriage of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in patients with gastroenteritis. During April 2011, all faecal samples submitted to our hospital laboratory were examined for ESBL-producing Enterobacteriaceae. Isolates expressing an ESBL phenotype were investigated for the presence of genes encoding broad-spectrum beta-lactamases, ESBLs, carbapenemases, and plasmid-mediated AmpC. Information on age, gender, and travel history was extracted from the laboratory records. In total 273 faecal samples were included. The overall carrier rate in the study population was 15.8%. The ESBL carrier rate among patients with no history of recent travel, or where this information was missing, was 10.3%. In contrast, the carrier rate was 56.3% (odds ratio 16.3, p < 0.001) among patients with a record of travel to Asia. Two ESBL-producing isolates were identified as enteropathogenic Escherichia coli. Co-resistance between third-generation cephalosporins, trimethoprim-sulfamethoxazole, and fluoroquinolones was seen in 49% of isolates. No carbapenemase-producers were found. PMID:24702690

Jørgensen, Silje Bakken; Samuelsen, Orjan; Sundsfjord, Arnfinn; Bhatti, Sidra Ahmad; Jørgensen, Ingvild; Sivapathasundaram, Thusanth; Leegaard, Truls Michael

2014-06-01

275

Treatment of Strontium Hexaferrite Powder Synthesized Conventionally to Produce High Coercivity  

Microsoft Academic Search

Strontium hexaferrite powder, produced conventionally from strontium carbonate and iron oxide has been treated in nitrogen and hydrogen atmospheres and then calcined in air. Magnetic measurements after the gas treatment stage indicated a marked decrease of intrinsic coercivity and an increase in saturation magnetisation. During the calcination stage there was a recovery of the magnetic properties. The material now exhibited

S. A. Seyyed Ebrahimi; A. J. Williams; N. Martinez; A. Ataie; A. Kianvash; C. B. Ponton; I. R. Harris

1997-01-01

276

Derivation of High Enterotoxin B-Producing Mutants of 'Staphylococcus aureus' from the Parent Strains.  

National Technical Information Service (NTIS)

Certain pH-sensitive (membrane) mutants of Staphylococcus aureus, strains 14458 and 778, produce significantly more type-B enterotoxin (SEB) than the parent type. Some carbohydrate mutants (car) from these parent strains also are superior to the parent in...

R. A. Altenbern

1975-01-01

277

Assessment of Early Postpartum Reproductive Performance in Two High Producing Estonian Dairy Herds  

PubMed Central

Early postpartum (6 weeks) ovarian activity, hormonal profiles, uterine involution, uterine infections, serum electrolytes, glucose, milk acetoacetate and blood urea nitrogen (BUN) levels were studied in 2 Estonian high producing dairy herd with annual milk production of 7688 (Farm A) and 9425 (Farm B). From each farm 10 cows, with normal calving performance were used. Blood samples for the hormonal (PGF2?-metabolite, progesterone) analyses were withdrawn. On day 25 PP blood serum samples were taken for the evaluation of metabolic/electrolyte status. On the same day estimation of milk acetoacetate values was done. The ultrasound (US) was started on day 7 PP and was performed every 3rd day until the end of experiment. Uterine content, follicular activity and sizes of the largest follicle and corpus luteum were monitored and measured. Vaginal discharge and uterine tone were recorded during the rectal palpation. Each animal in the study was sampled for bacteriological examination using endometrial biopsies once a week. Two types of PGF2?-metabolite patterns were detected: elevated levels during 14 days PP, then decline to the basal level and then a second small elevation at the time of final elimination of the bacteria from the uterus; or elevated levels during first 7 days PP, then decline to the basal level and a second small elevation before the final elimination of bacteria. Endometritis was diagnosed in 5 cows in farm A and in 3 cows in farm B respectively. In farm A, 5 cows out of 10 ovulated during experimental period and in 1 cow cystic ovaries were found. In farm B, 3 cows out of 10 ovulated. In 3 cows cystic ovaries were found. Altogether 40% of cows had their first ovulation during the experimental period. Three cows in farm A and 5 cows in farm B were totally bacteria negative during the experimental period. The most frequent bacteria found were A. pyogenes, Streptococcus spp., E. coli., F. necrophorum and Bacteroides spp. The highest incidence of bacteriological species was found during the first 3 weeks in both farms. All animals were free from bacteria after 5th week PP in farm A and after 4th week in farm B respectively. Serum electrolytes and glucose levels were found to be within the reference limits for the cows in both farms. No significant difference was found between farms (p > 0.05). Low phosphorus levels were found in both farms. Significant difference (p < 0.05) was found in BUN levels between farms. In both farms milk acetoacetate values were staying within the reference range given for the used test (<100 ?mol/l). The uterine involution and bacterial elimination in the investigated cows could consider as normal but more profound metabolic studies could be needed to find reasons for later resumption of ovarian activity. Some recommendations to changing feeding regimes and strategies should also be given.

Kask, K; Kurykin, J; Lindjarv, R; Kask, A; Kindahl, H

2003-01-01

278

Gaseous discharge plasmas produced by high-energy electron-irradiated insulators for spacecraft  

Microsoft Academic Search

High-energy electron irradiation of insulators in vacuum causes both internal regions and surfaces of insulators to achieve high (negative) static voltage relative to nearby “ground”. Occasional spontaneous discharges inject pulses of partially ionized gas composed of the insulating material and surface gas-adatoms into the adjacent vacuum. The gas is capable of partially discharging the high surface potentials by carrying current

Arthur Robb Frederickson; C. E. Benson; E. M. Cooke

2000-01-01

279

New approach to increasing rice lodging resistance and biomass yield through the use of high gibberellin producing varieties.  

PubMed

Traditional breeding for high-yielding rice has been dependent on the widespread use of fertilizers and the cultivation of gibberellin (GA)-deficient semi-dwarf varieties. The use of semi-dwarf plants facilitates high grain yield since these varieties possess high levels of lodging resistance, and thus could support the high grain weight. Although this approach has been successful in increasing grain yield, it is desirable to further improve grain production and also to breed for high biomass. In this study, we re-examined the effect of GA on rice lodging resistance and biomass yield using several GA-deficient mutants (e.g. having defects in the biosynthesis or perception of GA), and high-GA producing line or mutant. GA-deficient mutants displayed improved bending-type lodging resistance due to their short stature; however they showed reduced breaking-type lodging resistance and reduced total biomass. In plants producing high amounts of GA, the bending-type lodging resistance was inferior to the original cultivars. The breaking-type lodging resistance was improved due to increased lignin accumulation and/or larger culm diameters. Further, these lines had an increase in total biomass weight. These results show that the use of rice cultivars producing high levels of GA would be a novel approach to create higher lodging resistance and biomass. PMID:24586255

Okuno, Ayako; Hirano, Ko; Asano, Kenji; Takase, Wakana; Masuda, Reiko; Morinaka, Yoichi; Ueguchi-Tanaka, Miyako; Kitano, Hidemi; Matsuoka, Makoto

2014-01-01

280

A method of producing high quality oxide and related films on surfaces  

NASA Technical Reports Server (NTRS)

Aluminum oxide or aluminum nitride films were deposited on molecular beam epitaxy (MBE) grown GaAS(100) using a novel cryogenic-based reactive thin film deposition technique. The process involves the condensation of molecular oxygen, ammonia, or other gases normally used for reactive thin film deposition on the substrate before the metal is deposited. The metal vapor is deposited into this layer and reacts with the molecular solid to form the desired compound or a precursor that can be thermally decomposed to generate the desired compound. The films produced by this method are free of impurities, and the low temperatures can be used to control the film and interfacial structure. The process can be easily integrated with existing MBE systems. Ongoing research using the same apparatus suggests that photon or electron irradiation could be used to promote the reactions needed to produce the intended material.

Ruckman, Mark W.; Strongin, Myron; Gao, Yongli

1991-01-01

281

Development of a high-power neutron-producing lithium target for boron neutron capture therapy  

NASA Astrophysics Data System (ADS)

A neutron producing lithium target for a novel, accelerator based cancer treatment requires the removal of up to 6kW of heat produced by 1-2mA beam of 2.3-3.0MeV protons. This paper presents the results form computer simulations which show that, using submerged jet cooling, a solid lithium target can be maintained up to 1.6mA, and a liquid target up to 2.6mA, assuming a 3.0MeV proton beam. The predictions from the simulations are verified through the use of an experimental heat transfer test-rig and the result form a number of metallurgical studies made to select a compatible substrate material for the lithium are reported.

Brown, Adam V.; Scott, Malcolm C.

2000-12-01

282

High-temperature deformation behavior of aluminum alloys produced from centrifugally-atomized powders  

Microsoft Academic Search

Powder metallurgy (P\\/M) aluminum alloys have been expected to have extended application in the production of such items as automobile, aeroplane and machine parts. P\\/M AlAl?10mass%Mg and hyper-eutectic Al?Si alloys have been produced using a centrifugal-atomization process, which is one of the rapid-solidification techniques, and the possibility of superplastic deformation has been investigated because the components required have become of

T. Satoh; K. Okimoto; S. Nishida

1997-01-01

283

Generation of high-charge-state ions from CO2 laser-produced plasma  

Microsoft Academic Search

The measurement results are presented for angular dependency of the CO2 laser produced plasma parameters at power density of 4 by 1013W\\/cm2 and laser pulse duration of 14 ns. 2D numerical simulations are in sufficiently good agreement with experiment. It is shown that the light pressure effects on plasma expansion dynamics and the number of particles generated at the target

K. N. Makarov; S. V. Khomenko; S. G. Nischuk; V. C. Roerich; Yu. A. Satov; Yu. B. Smakovskii; A. E. Stepanov

2001-01-01

284

Feasibility of meltcasing strontium fluoride to produce high-density heat sources  

Microsoft Academic Search

Melt casting as a process for compacting SrF2 to near theoretical density was investigated. A nonradioactive SrF2 mixture, similar in chemical composition and method of preparation to SrF2 encapsulated at the Hanford waste encapsulation and storage facility (WESF) was used for the test evaluations. Hard, dimensionally stable, monolithic ingots that are 98% of theoretical density were produced. Significant chemical purification

E. J. Wheelwright; D. R. Montgomery

1985-01-01

285

The large plasmids of Shiga-toxin-producing Escherichia coli (STEC) are highly variable genetic elements  

Microsoft Academic Search

Shiga-toxin-producing Escherichia coli (STEC) of different serotypes are known to harbour large plasmids. The aim of this study was to investigate, using the example of the plasmid-encoded serine protease EspP, whether these plasmids are a uniform genetic element present in STEC. Examination of 201 diarrhoeagenic E. coli strains using a newly developed espP-specific PCR showed that espP is specific for

Werner Brunder; Herbert Schmidt; Matthias Frosch; Helge Karch

1999-01-01

286

Nonlinear sequential laminates reproducing hollow sphere assemblages  

NASA Astrophysics Data System (ADS)

A special class of nonlinear porous materials with isotropic 'sequentially laminated' microstructures is found to reproduce exactly the hydrostatic behavior of 'hollow sphere assemblages'. It is then argued that this result supports the conjecture that Gurson's approximate criterion for plastic porous materials, and its viscoplastic extension of Leblond et al. (1994), may actually yield rigorous upper bounds for the hydrostatic flow stress of porous materials containing an isotropic, but otherwise arbitrary, distribution of porosity. To cite this article: M.I. Idiart, C. R. Mecanique 335 (2007).

Idiart, Martín I.

2007-07-01

287

Development of Bottom-Fermenting Saccharomyces Strains That Produce High SO2 Levels, Using Integrated Metabolome and Transcriptome Analysis?  

PubMed Central

Sulfite plays an important role in beer flavor stability. Although breeding of bottom-fermenting Saccharomyces strains that produce high levels of SO2 is desirable, it is complicated by the fact that undesirable H2S is produced as an intermediate in the same pathway. Here, we report the development of a high-level SO2-producing bottom-fermenting yeast strain by integrated metabolome and transcriptome analysis. This analysis revealed that O-acetylhomoserine (OAH) is the rate-limiting factor for the production of SO2 and H2S. Appropriate genetic modifications were then introduced into a prototype strain to increase metabolic fluxes from aspartate to OAH and from sulfate to SO2, resulting in high SO2 and low H2S production. Spontaneous mutants of an industrial strain that were resistant to both methionine and threonine analogs were then analyzed for similar metabolic fluxes. One promising mutant produced much higher levels of SO2 than the parent but produced parental levels of H2S.

Yoshida, Satoshi; Imoto, Jun; Minato, Toshiko; Oouchi, Rie; Sugihara, Mao; Imai, Takeo; Ishiguro, Tatsuji; Mizutani, Satoru; Tomita, Masaru; Soga, Tomoyoshi; Yoshimoto, Hiroyuki

2008-01-01

288

80 GHz field-effect transistors produced using high purity semiconducting single-walled carbon nanotubes  

NASA Astrophysics Data System (ADS)

This paper presents the high frequency performance of single-walled carbon nanotube (SWNT) field-effect transistors, with channel consisting of dense networks of high purity semiconducting SWNTs. Using SWNT samples containing 99% pure semiconducting SWNTs, we achieved operating frequencies above 80 GHz. This record frequency does not require aligned SWNTs, thus demonstrating the remarkable potential of random networks of sorted SWNTs for high frequency electronics.

Nougaret, L.; Happy, H.; Dambrine, G.; Derycke, V.; Bourgoin, J.-P.; Green, A. A.; Hersam, M. C.

2009-06-01

289

Highly Flexible Dye-sensitized Solar Cells Produced by Sewing Textile Electrodes on Cloth  

PubMed Central

Textile forms of solar cells possess special advantages over other types of solar cells, including their light weight, high flexibility, and mechanical robustness. Recent demand for wearable devices has promoted interest in the development of high-efficiency textile-based solar cells for energy suppliers. However, the weaving process occurs under high-friction, high-tension conditions that are not conducive to coated solar-cell active layers or electrodes deposited on the wire or strings. Therefore, a new approach is needed for the development of textile-based solar cells suitable for woven fabrics for wide-range application. In this report, we present a highly flexible, efficient DSSC, fabricated by sewing textile-structured electrodes onto casual fabrics such as cotton, silk, and felt, or paper, thereby forming core integrated DSSC structures with high energy-conversion efficiency (~5.8%). The fabricated textile-based DSSC devices showed high flexibility and high performance under 4-mm radius of curvature over thousands of deformation cycles. Considering the vast number of textile types, our textile-based DSSC devices offer a huge range of applications, including transparent, stretchable, wearable devices.

Yun, Min Ju; Cha, Seung I.; Seo, Seon Hee; Lee, Dong Y.

2014-01-01

290

Highly Flexible Dye-sensitized Solar Cells Produced by Sewing Textile Electrodes on Cloth.  

PubMed

Textile forms of solar cells possess special advantages over other types of solar cells, including their light weight, high flexibility, and mechanical robustness. Recent demand for wearable devices has promoted interest in the development of high-efficiency textile-based solar cells for energy suppliers. However, the weaving process occurs under high-friction, high-tension conditions that are not conducive to coated solar-cell active layers or electrodes deposited on the wire or strings. Therefore, a new approach is needed for the development of textile-based solar cells suitable for woven fabrics for wide-range application. In this report, we present a highly flexible, efficient DSSC, fabricated by sewing textile-structured electrodes onto casual fabrics such as cotton, silk, and felt, or paper, thereby forming core integrated DSSC structures with high energy-conversion efficiency (~5.8%). The fabricated textile-based DSSC devices showed high flexibility and high performance under 4-mm radius of curvature over thousands of deformation cycles. Considering the vast number of textile types, our textile-based DSSC devices offer a huge range of applications, including transparent, stretchable, wearable devices. PMID:24957920

Yun, Min Ju; Cha, Seung I; Seo, Seon Hee; Lee, Dong Y

2014-01-01

291

Feasibility of meltcasing strontium fluoride to produce high-density heat sources  

SciTech Connect

A modest proof-of-principle effort has been conducted to investigate melt casting as a process for compacting SrF/sub 2/ to near theoretical density. A nonradioactive SrF/sub 2/ mixture, similar in chemical composition and method of prepartion to SrF/sub 2/ encapsulated at the Hanford Waste Encapsulation and Storage Facility (WESF) was used for the test evaluations. Hard, dimensionally stable, monolithic ingots that are >98% of theoretical density have been produced. Significant chemical purification from Al, Fe, Cr, Ni, Na and Zr has been demonstrated.

Wheelwright, E.J.; Montgomery, D.R.

1985-02-01

292

Precision and Reproducibility in Biological Patterning  

NASA Astrophysics Data System (ADS)

During embryonic development, information about spatial location is represented by the concentration of various morphogen molecules. The reproducibility and precision of biological pattern formation thus is limited by the accuracy with which these concentration profiles can be established and ``read out'' by their target pathways. We consider four measures of precision for the Bicoid morphogen in the Drosophila embryo: The concentration differences that distinguish neighboring cells, the limits set by the random arrival of Bcd molecules at their targets (which depends on the absolute concentration), the noise in readout of Bcd by the activation of Hunchback, and the reproducibility of Bcd concentration at corresponding positions in multiple embryos. We show, through a combination of different experiments, that all of these quantities are ˜10%. This agreement among different measures of accuracy, which depend on very different molecular mechanisms, indicates that the embryo is not faced with sloppy input signals and noisy readout mechanisms; rather we have to understand how the embryo exerts precise control over absolute concentrations and responds reliably to small changes in these concentrations, down to the limits set by basic physical principles.

Gregor, Thomas; Wieschaus, Eric F.; Bialek, William; Tank, David W.

2007-03-01

293

Fish Offal Recycling by the Black Soldier Fly Produces a Foodstuff High in Omega3 Fatty Acids  

Microsoft Academic Search

The black soldier fly, Hermetia illucens, has the potential to reduce animal waste on livestock facilities and produce an animal-grade feedstuff high in protein and fat. The lipid content of insects is largely dependent on their diet. Data from this study suggest that black soldier fly prepupae incorporate a-linolenic acid (ALA), eicosapen- taenoic acid (EPA), and docosahexaenoic acid (DHA) when

Sophie St-Hilaire; Katie Cranfill; Mark A. McGuire; Erin E. Mosley; Jeffery K. Tomberlin; Larry Newton; Wendy Sealey; Craig Sheppard; Stephen Irving

2007-01-01

294

Process for producing silicon nitride based articles of high fracture toughness and strength  

DOEpatents

A process for producing a silicon nitride-based article of improved fracture toughness and strength is disclosed. The process involves densifying to at least 98% of theoretical density a mixture including (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12 m[sup 2]/g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. Optionally, the mixture may be blended with a binder and injection molded to form a green body, which then may be densified by, for example, hot isostatic pressing.

Huckabee, M.; Buljan, S.T.; Neil, J.T.

1991-09-10

295

Reproducible tip fabrication and cleaning for UHV STM.  

PubMed

Several technical modifications related to the fabrication and ultra-high vacuum (UHV) treatments of the scanning tunneling microscope (STM) tips have been implemented to improve a reliability of the tip preparation for high-resolution STM. Widely used electrochemical etching drop-off technique has been further refined to enable a reproducible fabrication of the tips with a radius

Yu, Z Q; Wang, C M; Du, Y; Thevuthasan, S; Lyubinetsky, I

2008-08-01

296

Chemotherapy for malignant melanoma: combinations and high doses produce more responses without survival benefit.  

PubMed Central

In a consecutive series of studies, 164 patients with symptomatic and/or visceral metastatic malignant melanoma were treated with single agent vindesine, high dose melphalan with autologous bone marrow transplantation (AMBT), high dose BCNU with ABMT or the BOLD (bleomycin, vincristine, CCNU and DTIC) combination. The high dose treatments and the combination chemotherapy resulted in significantly higher response rates but no prolongation of survival. Factors associated with longer survival included the absence of visceral metastases, the absence of bulky disease and good performance status. For all treatments, life table estimates of survival at 1 and 2 years were only 10% and 4% respectively.

Lakhani, S.; Selby, P.; Bliss, J. M.; Perren, T. J.; Gore, M. E.; McElwain, T. J.

1990-01-01

297

Observation of Dust Stream Formation Produced by Low Current, High Voltage Cathode Spots  

NASA Technical Reports Server (NTRS)

Macro-particle acceleration driven by low current, high voltage cathode spots has been investigated. The phenomenon was observed to occur when nanometer and micrometer-sized particles in the presence of a discharge plasma were exposed to a high voltage pulse. The negative voltage pulse initiates the formation of multiple, high voltage, low current cathode spots which provides the mechanism of actual acceleration of the charged dust particles. Dust streams generated by this process were detected using laser scattering techniques. The particle impact craters observed at the surface of downstream witness badges were documented using SEM and light microscopy.

Foster, John E.

2004-01-01

298

Isolation of Bacillus subtilis (chungkookjang), a poly-?-glutamate producer with high genetic competence  

Microsoft Academic Search

A bacterium with high poly-?-glutamate (PGA) productivity was isolated from the traditional Korean seasoning, Chung-Kook-Jang. This bacterium could be classified as a Bacillus subtilis, but sporulation in culture was infrequent in the absence of Mn 2+. It was judged to be a variety of B. subtilis and designated B. subtilis ( chungkookjang). L-Glutamate significantly induced PGA production, and highly elongated

M. Ashiuchi; T. Kamei; D.-H. Baek; S.-Y. Shin; M.-H. Sung; K. Soda; T. Yagi; H. Misono

2001-01-01

299

Highly Active HDS Catalyst for Producing Ultra-low Sulfur Diesel Fuels  

Microsoft Academic Search

Cosmo Oil Co., Ltd. developed a highly active CoMo HDS catalyst, C-606A, for the production of ultra-low sulfur diesel fuels.\\u000a This patented preparation method involves impregnation of the support with a solution containing CoCO3, MoO3, citric acid, and phosphoric acid, and air-drying without calcination, to provide the high activity HDS catalyst. XPS studies\\u000a suggested that the addition of citric acid

Takashi Fujikawa

2009-01-01

300

Analysis of Atomic Beams Produced by Laser-Induced Ablation  

Microsoft Academic Search

Pulsed atomic beams with flux densities above 1016 cm-2 s-1 have been produced in vacuum with high reproducibility by laser induced ablation from titanium and iron targets. The power of the TEA CO2 laser was kept at a level where plasma production at the target surface was avoided: no ions were detectable. The beams were analysed by laser fluorescence. The

K P Selter; H-J Kunze

1982-01-01

301

Git can facilitate greater reproducibility and increased transparency in science  

PubMed Central

Background Reproducibility is the hallmark of good science. Maintaining a high degree of transparency in scientific reporting is essential not just for gaining trust and credibility within the scientific community but also for facilitating the development of new ideas. Sharing data and computer code associated with publications is becoming increasingly common, motivated partly in response to data deposition requirements from journals and mandates from funders. Despite this increase in transparency, it is still difficult to reproduce or build upon the findings of most scientific publications without access to a more complete workflow. Findings Version control systems (VCS), which have long been used to maintain code repositories in the software industry, are now finding new applications in science. One such open source VCS, Git, provides a lightweight yet robust framework that is ideal for managing the full suite of research outputs such as datasets, statistical code, figures, lab notes, and manuscripts. For individual researchers, Git provides a powerful way to track and compare versions, retrace errors, explore new approaches in a structured manner, while maintaining a full audit trail. For larger collaborative efforts, Git and Git hosting services make it possible for everyone to work asynchronously and merge their contributions at any time, all the while maintaining a complete authorship trail. In this paper I provide an overview of Git along with use-cases that highlight how this tool can be leveraged to make science more reproducible and transparent, foster new collaborations, and support novel uses.

2013-01-01

302

Reporting research antibody use: how to increase experimental reproducibility  

PubMed Central

Research antibodies are used in a wide range of bioscience disciplines, yet it is common to hear dissatisfaction amongst researchers with respect to their quality. Although blame is often attributed to the manufacturers, scientists are not doing all they can to help themselves. One example of this is in the reporting of research antibody use. Publications routinely lack key details, including the host species, code number and even the company who supplied the antibody. Authors also fail to demonstrate that validation of the antibodies has taken place. These omissions make it harder for reviewers to establish the likely reliability of the results and for researchers to reproduce the experiments. The scale of this problem, combined with high profile concerns about experimental reproducibility, has caused the Nature Publishing Group to include a section on antibody information in their recent Reporting Checklist for Life Science Articles. In this commentary we consider the issue of reporting research antibody use and ask what details authors should be including in their publications to improve experimental reproducibility.

Chalmers, Andrew D

2013-01-01

303

Optical pyrometer system for collisionless shock experiments in high-power laser-produced plasmas  

SciTech Connect

A temporally and spatially resolved optical pyrometer system has been fielded on Gekko XII experiments. The system is based on the self-emission measurements with a gated optical imager (GOI) and a streaked optical pyrometer (SOP). Both detectors measure the intensity of the self-emission from laser-produced plasmas at the wavelength of 450 nm with a bandpass filter with a width of {approx}10 nm in FWHM. The measurements were calibrated with different methods, and both results agreed with each other within 30% as previously reported [T. Morita et al., Astrophys. Space Sci. 336, 283 (2011)]. As a tool for measuring the properties of low-density plasmas, the system is applicable for the measurements of the electron temperature and density in collisionless shock experiments [Y. Kuramitsu et al., Phys. Rev. Lett. 106, 175002 (2011)].

Morita, T.; Sakawa, Y.; Kuramitsu, Y.; Sano, T.; Takabe, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Dono, S.; Ide, T.; Tanji, H.; Shiroshita, A. [Graduate School of Engineering, Osaka University, 1-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Shibata, S.; Aoki, H. [Graduate School of Science, Osaka University, 1-1 Machikane-yama, Toyonaka, Osaka 560-0043 (Japan); Waugh, J. N.; Woolsey, N. C. [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Gregory, C. D. [LULI, Ecole Polytechnique, CNRS, CEA, UPMC, Route de Saclay, 91128 Palaiseau (France)

2012-10-15

304

Optical pyrometer system for collisionless shock experiments in high-power laser-produced plasmas.  

PubMed

A temporally and spatially resolved optical pyrometer system has been fielded on Gekko XII experiments. The system is based on the self-emission measurements with a gated optical imager (GOI) and a streaked optical pyrometer (SOP). Both detectors measure the intensity of the self-emission from laser-produced plasmas at the wavelength of 450 nm with a bandpass filter with a width of ~10 nm in FWHM. The measurements were calibrated with different methods, and both results agreed with each other within 30% as previously reported [T. Morita et al., Astrophys. Space Sci. 336, 283 (2011)]. As a tool for measuring the properties of low-density plasmas, the system is applicable for the measurements of the electron temperature and density in collisionless shock experiments [Y. Kuramitsu et al., Phys. Rev. Lett. 106, 175002 (2011)]. PMID:23126856

Morita, T; Sakawa, Y; Kuramitsu, Y; Dono, S; Ide, T; Shibata, S; Aoki, H; Tanji, H; Sano, T; Shiroshita, A; Waugh, J N; Gregory, C D; Woolsey, N C; Takabe, H

2012-10-01

305

CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance  

NASA Technical Reports Server (NTRS)

A method of depositing by chemical vapor deposition a modified platinum aluminide diffusion coating onto a superalloy substrate comprising the steps of applying a layer of a platinum group metal to the superalloy substrate; passing an externally generated aluminum halide gas through an internal gas generator which is integral with a retort, the internal gas generator generating a modified halide gas; and co-depositing aluminum and modifier onto the superalloy substrate. In one form, the modified halide gas is hafnium chloride and the modifier is hafnium with the modified platinum aluminum bond coat comprising a single phase additive layer of platinum aluminide with at least about 0.5 percent hafnium by weight percent and about 1 to about 15 weight percent of hafnium in the boundary between a diffusion layer and the additive layer. The bond coat produced by this method is also claimed.

Nagaraj, Bangalore A. (Inventor); Williams, Jeffrey L. (Inventor)

2003-01-01

306

Quantitative measurement of hard x-ray spectra for high intensity laser produced plasma.  

PubMed

X-ray line spectra ranging from 17 to 77 keV were quantitatively measured with a Laue spectrometer, composed of a cylindrically curved crystal and a detector. Either a visible CCD detector coupled with a CsI phosphor screen or an imaging plate can be chosen, depending on the signal intensities and exposure times. The absolute sensitivity of the spectrometer system was calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency for specific x-ray line emissions, is derived as a consequence of this work. PMID:22667617

Zhang, Z; Nishimura, H; Namimoto, T; Fujioka, S; Arikawa, Y; Nishikino, M; Kawachi, T; Sagisaka, A; Hosoda, H; Orimo, S; Ogura, K; Pirozhkov, A; Yogo, A; Okano, Y; Kiriyama, H; Kondo, K; Ohshima, S; Azechi, H

2012-05-01

307

X-ray spectral line shapes for the excimer-laser-produced high density plasma diagnostics  

SciTech Connect

The time and space-integrated emission spectra measurements have been performed in plasma produced by 308 nm wavelength XeCl laser radiation (I{sub L}=(4-10){center_dot}10{sup 12} W/cm{sup 2}, {tau}=10 ns) and by 248 nm wavelength KrF laser pulse train radiation I{sub L}=5{center_dot}10{sup 15} W/cm{sup 2}, {tau}=7 ps, 16 pulses in train) on (CF{sub n} plane target. The lines' shapes and intensities modeling of Lyman series and He-like ion resonance series of fluorine up to n=7 by fitting experimental data shows the considerable difference of plasma formation features for these two sets of the laser pulse parameters.

Magunov, A.; Faenov, A.; Skobelev, I.; Pikuz, T.; Batani, D.; Milani, M.; Conti, A.; Masini, A.; Costato, M.; Pozzi, A.; Turcu, E.; Allot, R.; Lisi, N.; Koenig, M.; Benuzzi, A.; Flora, F.; Letardi, T.; Palladino, L.; Reale, A. [Multicharged Ions Spectra Data Center, VNIIFTRI, Mendeleevo, 141570 (Russian Federation); Dipartimento di Fisica, Universita di Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione. di Milano (Italy); Dipartimento di Fisica, Univerista di Milano (Italy); Dipartimento di Fisica, Universita di Modena (Italy); Rutherford Appleton Laboratory (United Kingdom); LULl, Ecole Polytechnique (France); Dipartimento Innovazione, Settore INN-FIS, CRE ENEA, Frascati (Italy); Dipartimento di Fisica, Universita dell' Aquila, e INFN G. Coll. LNGS, Assergi (Italy)

1997-01-05

308

X-ray spectral line shapes for the excimer-laser-produced high density plasma diagnostics  

SciTech Connect

The time and space-integrated emission spectra measurements have been performed in plasma produced by 308 nm wavelength XeCl laser radiation (I{sub L}=(4{minus}10){center_dot}10{sup 12} W/cm{sup 2}, {tau}=10 ns) and by 248 nm wavelength KrF laser pulse train radiation (I{sub L}=5{center_dot}10{sup 15} W/cm{sup 2}, {tau}=7 ps, 16 pulses in train) on CF{sub n} plane target. The lines` shapes and intensities modeling of Lyman series and He-like ion resonance series of fluorine up to n=7 by fitting experimental data shows the considerable difference of plasma formation features for these two sets of the laser pulse parameters.

Magunov, A.; Faenov, A.; Skobelev, I.; Pikuz, T. [Multicharged Ions Spectra Data Center, VNIIFTRI, Mendeleevo, 141570 (Russia); Batani, D.; Milani, M.; Conti, A. [Dipartimento di Fisica, Universita di Milano (Italy)]|[Istituto Nazionale di Fisica Nucleare, Sezione. di Milano (Italy); Masini, A. [Dipartimento di Fisica, Univerista di Milano (Italy); Costato, M.; Pozzi, A. [Dipartimento di Fisica, Universita di Modena (Italy); Turcu, E.; Allot, R.; Lisi, N. [Rutherford Appleton Laboratory (United Kingdom); Koenig, M.; Benuzzi, A. [LULl, Ecole Polytechnique (France); Flora, F.; Letardi, T. [Dipartimento Innovazione, Settore INN-FIS, CRE ENEA, Frascati (Italy); Palladino, L.; Reale, A. [Dipartimento di Fisica, Universita dell Aquila, e INFN G. Coll. LNGS, Assergi (Italy)

1997-01-01

309

Quantitative measurement of hard x-ray spectra for high intensity laser produced plasma  

SciTech Connect

X-ray line spectra ranging from 17 to 77 keV were quantitatively measured with a Laue spectrometer, composed of a cylindrically curved crystal and a detector. Either a visible CCD detector coupled with a CsI phosphor screen or an imaging plate can be chosen, depending on the signal intensities and exposure times. The absolute sensitivity of the spectrometer system was calibrated using pre-characterized laser-produced x-ray sources and radioisotopes. The integrated reflectivity for the crystal is in good agreement with predictions by an open code for x-ray diffraction. The energy transfer efficiency from incident laser beams to hot electrons, as the energy transfer agency for specific x-ray line emissions, is derived as a consequence of this work.

Zhang, Z.; Nishimura, H.; Namimoto, T.; Fujioka, S.; Arikawa, Y.; Hosoda, H.; Azechi, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Nishikino, M.; Kawachi, T.; Sagisaka, A.; Orimo, S.; Ogura, K.; Pirozhkov, A.; Yogo, A.; Kiriyama, H.; Kondo, K. [Quantum Beam Science Directorate, Kansai Photon Science Institute, JAEA, Kyoto 619-0215 (Japan); Okano, Y. [Laser Research Center for Molecular Science, Institute for Molecular Science, National Institute of Natural Science 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585 (Japan); Ohshima, S. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565-0871 (Japan); Pioneering Research Unit for Next Generation, Kyoto University, Uji 611-0011 (Japan)

2012-05-15

310

Reconstructed skin kits: reproducibility of cutaneous irritancy testing.  

PubMed

The aim of this study was to determine the reproducibility of data obtained from in vitro irritation testing using three industrial reconstructed human epidermis models, EpiDerm, Episkin and SkinEthic, and one in-house model developed at Wella/Cosmital. A common protocol was established based on the measurement of cytotoxicity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and of extracellular release of proinflammatory mediators and cytosolic enzymes after a range of exposure times to sodium lauryl sulfate (SLS). This time course protocol was applied to 6 different batches of each skin model using triplicate tissue cultures per test condition. The parameters analyzed for intra- and inter-batch reproducibility were the cell viability determined as MTT reduction capacity and the ET-50 values in the 6 batches, as well as the release of the cytokine IL-1alpha and of the cellular enzymes LDH and GOT in 3 batches only. The MTT viability results showed that EpiDerm was the most resistant to the SLS treatment and at the same time the most reproducible model, SkinEthic was the most sensitive to SLS and the least reproducible, and Episkin and the Cosmital model were intermediate. Measurements of IL-1alpha release showed a relatively high intra- and inter-batch variability in all the skin models. It was not possible to detect the extracellular release of the enzymes LDH and GOT in the Episkin assay medium. With the 3 other models, the release of LDH and GOT varied in about the same range as that of IL-1alpha. For all the parameters in this study, the inter-batch variability was generally greater than the intra-batch variability. A possible reduction in the number of batches and replicates for future applications in routine irritancy testing is discussed on the basis of the results obtained using 6 batches in triplicate. PMID:12476011

Faller, C; Bracher, M

2002-01-01

311

Precipitation strengthened high strength, high conductivity Cu-Cr-Nb alloys produced by chill block melt spinning. Final report Ph. D. Thesis  

Microsoft Academic Search

A series of Cu-based alloys containing 2 to 10 a\\/o Cr and 1 to 5 a\\/o Nb were produced by chill block melt spinning (CBMS). The melt spun ribbons were consolidated and hot rolled to sheet to produce a supersaturated Cu-Cr-Nb solid solution from which the high melting point intermetallic compound Cr2Nb could be precipitated to strengthen the Cu matrix.

D. L. Ellis; G. M. Michal

1989-01-01

312

High spectral contrast filtering produced by multiple pass reflections from paired Bragg gratings in PTR glass  

NASA Astrophysics Data System (ADS)

The properties of multiple reflections from narrow bandwidth reflection Bragg gratings are presented. The use of multiple reflections serves to increase the suppression ratio of the out-of-band spectral content such that contributions of grating sidelobes can be mitigated. The result is a device which retains spectral and angular selectivity in a single high efficiency diffraction order but reshapes spectral/angular response to achieve higher signal to noise ratios (SNR). The material for recording these high suppression devices is photo-thermo-refractive (PTR) glass. PTR is a highly homogeneous photosensitive glass with features such as low losses and high laser damage threshold. It has recently been used with good success to record permanent volume Bragg gratings with high efficiency and narrow band selectivity for use in laser cavities. Multiple reflections from the grating surface are achieved using several different arrangements. The multiple pass grating reflections are demonstrated and compared to the performance of a single reflection from a volume Bragg grating.

Ott, Daniel; SeGall, Marc; Divliansky, Ivan; Venus, George; Glebov, Leonid

2014-03-01

313

A review of research and methods for producing high-consequence software  

SciTech Connect

The development of software for use in high-consequence systems mandates rigorous (formal) processes, methods, and techniques to improve the safety characteristics of those systems. This paper provides a brief overview of current research and practices in high-consequence software, including applied design methods. Some of the practices that are discussed include: fault tree analysis, failure mode effects analysis, petri nets, both hardware and software interlocks, n-version programming, Independent Vulnerability Analyses, and watchdogs. Techniques that offer improvement in the dependability of software in high-consequence systems applications are identified and discussed. Limitations of these techniques are also explored. Research in formal methods, the cleanroom process, and reliability models are reviewed. In addition, current work by several leading researchers as well as approaches being used by leading practitioners are examined.

Collins, E.; Dalton, L.; Peercy, D.; Pollock, G.; Sicking, C.

1994-12-31

314

A high-resolution coherent transition radiation diagnostic for laser-produced electron transport studies (invited)  

NASA Astrophysics Data System (ADS)

High-resolution images of the rear-surface optical emission from high-intensity (I~1019 W/cm2) laser illuminated metal foils have been recorded using coherent transition radiation (CTR). CTR is generated as relativistic electrons, generated in high-intensity laser-plasma interactions, exit the target's rear surface and move into vacuum. A transition radiation diagnostic (TRD) records time-integrated images in a 24 nm bandwidth window around ?=529 nm. The optical transmission at ?=1053 nm, the laser wavelength, is 15 orders of magnitude lower than the transmission at the wavelength of interest, ?=527 nm. The detector is a scientific grade charge-coupled device (CCD) camera that operates with a signal-to-noise ratio of 103 and has a dynamic range of 104. The TRD has demonstrated a spatial resolution of 1.4 ?m over a 1 mm field of view, limited only by the CCD pixel size.

Storm, M.; Begishev, I. A.; Brown, R. J.; Guo, C.; Meyerhofer, D. D.; Mileham, C.; Myatt, J. F.; Nilson, P. M.; Sangster, T. C.; Stoeckl, C.; Theobald, W.; Zuegel, J. D.

2008-10-01

315

Effects of Neutral Density on Energetic Ions Produced Near High-Current Hollow Cathodes  

NASA Technical Reports Server (NTRS)

Energy distributions of ion current from high-current, xenon hollow cathodes, which are essential information to understand erosion phenomena observed in high-power ion thrusters, were obtained using an electrostatic energy analyzer (ESA). The effects of ambient pressure and external flow rate introduced immediately downstream of hollow cathode on ion currents with energies greater than that associated with the cathode-to-anode potential difference were investigated. The results were analyzed to determine the changes in the magnitudes of ion currents to the ESA at various energies. Either increasing the ambient pressure or adding external flow induces an increase in the distribution of ion currents with moderate energies (epsilon less than 25 to 35 eV) and a decrease in the distribution for high energies (epsilon greater than 25 to 35 eV). The magnitude of the current distribution increase in the moderate energy range is greater for a cathode equipped with a toroidal keeper than for one without a keeper, but the distribution in the high energy range does not seem to be affected by a keeper. An MHD model, which has been proposed to describe energetic-ion production mechanism in hollow cathode at high discharge currents, was developed to describe these effects. The results show, however, that this model involves no mechanism by which a significant increase of ion current could occur at any energy. It was found, on the other hand, that the potential-hill model of energetic ion production, which assumes existence of a local maximum of plasma potential, could explain combined increases in the currents of ions with moderate energies and decreases in high energy ions due to increased neutral atom density using a charge-exchange mechanism. The existing, simplified version of the potential-hill model, however, shows poor quantitative agreement with measured ion-current-energy-distribution changes induced by neutral density changes.

Kameyama, Ikuya

1997-01-01

316

Properties and biodegradability of ultra-high-molecular-weight poly[( R)-3-hydroxybutyrate] produced by a recombinant Escherichia coli  

Microsoft Academic Search

Ultra-high-molecular-weight poly[(R)-3-hydroxybutyrate] (P(3HB)) (Mw=3–11×106) was produced from glucose by a recombinant Escherichia coli XL1-Blue (pSYL105) harboring Ralstonia eutropha H16 polyhydroxyalkanoate (PHA) biosynthesis genes. Morphology of ultra-high-molecular-weight P(3HB) granules in the recombinant cells was studied by transmission electron microscopy. The recombinant E. coli contained several P(3HB) granules within a cell. Freeze-fracture morphology of ultra-high-molecular-weight P(3HB) granules showed the needle-type as that

Satoshi Kusaka; Tadahisa Iwata; Yoshiharu Doi

1999-01-01

317

Solar photo-thermal catalytic reactions to produce high value chemicals.  

National Technical Information Service (NTIS)

This report presents a summary of the research work accomplished to date on the utilization of solar photo-thermal energy to convert low cost chemical feedstocks into high $-value chemical products. The rationale is that the solar IR-VIS-UV spectrum is un...

H. W. Prengle W. E. Wentworth

1992-01-01

318

Novel method for producing high frequency 2-2 composites from PZT ceramic  

Microsoft Academic Search

The fabrication of 2-2 PZT\\/epoxy composites by laminating ceramic tape printed with carbon black was investigated as a way to make very high frequency ultrasound transducers. When the laminates were fired, the tape layers densified to form the PZT beams and the carbon volatilized leaving behind kerf space. The kerf was then filled with epoxy, and resulting composites had properties

Wesley Hackenberger; Ming-Jen Pan; Daryl Kuban; Timothy Ritter; Thomas Shrout

2000-01-01

319

Case Study: Louvered Screen Produces High Efficiency Boreholes for Mine Dewatering - Sub-Saharan Africa  

Microsoft Academic Search

Each dewatering borehole within a dewatering system is designed to accommodate a dedicated pump whose capacity may be several thousand cubic meters of water per day. A typical network of dewatering boreholes (i.e. wellfield) is designed to operate continuously 24 hours-per day without interruption. Its demands for power or fuel are often high, particularly when the efficiencies of the boreholes

320

(Search for strange quark matter and antimatter produced in high energy heavy ion collisions)  

SciTech Connect

This document describes the development and progress of our group's research program in high energy heavy ion physics. We are a subset of the Yale experimental high energy physics effort (YAUG group) who became interested in the physics of high energy heavy ions in 1988. Our interest began with the possibility of performing significant searches for strange quark matter. As we learned more about the subject and as we gained experimental experience through our participation in AGS experiment 814, our interests have broadened. Our program has focused on the study of new particles, including (but not exclusively) strange quark matter, and the high sensitivity measurement of other composite nuclear systems such as antinuclei and various light nuclei. The importance of measurements of the known, but rare, nuclear systems lies in the study of production mechanisms. A good understanding of the physics and phenomenology of rare composite particle production in essential for the interpretation of limits to strange quark matter searches. We believe that such studies will also be useful in probing the mechanisms involved in the collision process itself. We have been involved in the running and data analysis for AGS E814. We have also worked on the R D for AGS E864, which is an approved experiment designed to reach sensitivities where there will be a good chance of discovering strangelets or of setting significant limits on the parameters of strange quark matter.

Not Available

1992-01-01

321

Alkali slurry ozonation to produce a high capacity nickel battery material  

DOEpatents

A high capacity battery material is made, consisting essentially of hydrated Ni(II) hydroxide, and about 5 wt. % to about 40 wt. % of Ni(IV) hydrated oxide interlayer doped with alkali metal cations selected from potassium, sodium and lithium cations.

Jackovitz, John F. (Monroeville, PA); Pantier, Earl A. (Penn Hills, PA)

1984-11-06

322

Highly conductive multiwall carbon nanotube and epoxy composites produced by three-roll milling  

Microsoft Academic Search

Length and diameter distributions as well as the conductivity of bucky papers made of different multiwalled carbon nanotubes (MWCNTs) have been measured. While the average diameter is in good agreement with the manufacturer specification, the average length is significantly shorter than that given by the manufacturer. Highly conductive and homogeneous dispersions of up to 8wt% MWCNTs in an epoxy resin

Iosif D. Rosca; Suong V. Hoa

2009-01-01

323

Research Investigation of Phase-Reinforced High Temperature Alloys Produced Directly from a Melt.  

National Technical Information Service (NTIS)

The results of preliminary studies on potential whisker-reinforcing high-temperature eutectic alloys are presented. The eutectic compositions have been re-established in the Ni-Ni3B and NiNiBe systems and the published eutectic composition confirmed in th...

J. A. Ford F. D. Lemkey B. J. Bayles

1964-01-01

324

Method of producing highly oxidized superconductors containing barium, copper, and a third metal  

DOEpatents

Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed.

Morris, Donald E. (Kensington, CA)

1996-01-01

325

Method of producing highly oxidized superconductors containing barium, copper, and a third metal  

DOEpatents

Novel superconducting materials in the form of compounds, structures or phases are formed by performing otherwise known syntheses in a highly oxidizing atmosphere rather than that created by molecular oxygen at atmospheric pressure or below. This leads to the successful synthesis of novel superconducting compounds which are thermodynamically stable at the conditions under which they are formed. 16 figs.

Morris, D.E.

1996-02-20

326

Novel APP/A? mutation K16N produces highly toxic heteromeric A? oligomers  

PubMed Central

Here, we describe a novel missense mutation in the amyloid precursor protein (APP) causing a lysine-to-asparagine substitution at position 687 (APP770; herein, referred to as K16N according to amyloid-? (A?) numbering) resulting in an early onset dementia with an autosomal dominant inheritance pattern. The K16N mutation is located exactly at the ?-secretase cleavage site and influences both APP and A?. First, due to the K16N mutation APP secretion is affected and a higher amount of A? peptides is being produced. Second, A? peptides carrying the K16N mutation are unique in that the peptide itself is not harmful to neuronal cells. Severe toxicity, however, is evident upon equimolar mixture of wt and mutant peptides, mimicking the heterozygous state of the subject. Furthermore, A?42 K16N inhibits fibril formation of A?42 wild-type. Even more, A?42 K16N peptides are protected against clearance activity by the major A?-degrading enzyme neprilysin. Thus the mutation characterized here harbours a combination of risk factors that synergistically may contribute to the development of early onset Alzheimer disease.

Kaden, Daniela; Harmeier, Anja; Weise, Christoph; Munter, Lisa M; Althoff, Veit; Rost, Benjamin R; Hildebrand, Peter W; Schmitz, Dietmar; Schaefer, Michael; Lurz, Rudi; Skodda, Sabine; Yamamoto, Raina; Arlt, Sonke; Finckh, Ulrich; Multhaup, Gerd

2012-01-01

327

Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.  

PubMed

The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60?kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40?°C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30?°C after 5 days fermentation, the quercetin production raised up to 1.78?mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds. PMID:22581711

Zheng, Ya-Di; Luo, Qing-Lin; Zhou, Mei-Liang; Wang, De-Zhou; Zhang, Ye-Dong; Shao, Ji-Rong; Zhu, Xue-Mei; Tang, Yu

2013-02-01

328

Increasing gas hydrate formation temperature for desalination of high salinity produced water with secondary guests  

SciTech Connect

We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from ?2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydrate turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.

Cha, Jong-Ho [ORISE; Seol, Yongkoo [U.S. DOE

2013-01-01

329

Extending the laserspray ionization concept to produce highly charged ions at high vacuum on a time-of-flight mass analyzer.  

PubMed

A new matrix compound, 2-nitrophloroglucinol, is reported which not only produces highly charged ions similar to electrospray ionization (ESI) under atmospheric pressure (AP) and intermediate pressure (IP) laserspray ionization (LSI) conditions but also the most highly charged ions so far observed for small proteins in mass spectrometry (MS) under high vacuum (HV) conditions. This new matrix extends the compounds that can successfully be employed as matrixes with LSI, as demonstrated on an LTQ Velos (Thermo) at AP, a matrix-assisted laser desorption/ionization (MALDI)-ion mobility spectrometry (IMS) time-of-flight (TOF) SYNAPT G2 (Waters) at IP, and MALDI-TOF Ultraflex, UltrafleXtreme, and Autoflex Speed (Bruker) mass spectrometers at HV. Measurements show that stable multiple charged molecular ions of proteins are formed under all pressure conditions indicating softer ionization than MALDI, which suffers a high degree of metastable fragmentation when multiply charged ions are produced. An important analytical advantage of this new LSI matrix are the potential for high sensitivity equivalent or better than AP-LSI and vacuum MALDI and the potential for enhanced mass selected fragmentation of the abundant highly charged protein ions. A second new LSI matrix, 4,6-dinitropyrogallol, produces abundant multiply charged ions at AP but not under HV conditions. The differences in these similar compounds ability to produce multiply charged ions under HV conditions is believed to be related to their relative ability to evaporate from charged matrix/analyte clusters. PMID:21678939

Trimpin, Sarah; Ren, Yue; Wang, Beixi; Lietz, Christopher B; Richards, Alicia L; Marshall, Darrell D; Inutan, Ellen D

2011-07-15

330

High-resolution X-ray focusing concave (elliptical) curved crystal spectrograph for laser-produced plasma  

NASA Astrophysics Data System (ADS)

The X-ray spectrum emitted from laser-produced plasma contains plentiful information. X-ray spectrometer is a powerful tool for plasma diagnosis and studying the information and evolution of the plasma. X-ray concave (elliptical) curved crystals analyzer was designed and manufactured to investigate the properties of laser-produced plasma. The experiment was carried out on Mianyang Xingguang-II Facility and aimed at investigating the characteristics of a high density iron plasma. Experimental results using KAP, LIF, PET, and MICA curved crystal analyzers are described, and the spectra of Au, Ti laser-produced plasma are shown. The focusing crystal analyzer clearly gave an increase in sensitivity over a flat crystal.

Xiao, Shali; Pan, Yingjun; Zhong, Xianxin; Xiong, Xiancai; Yang, Guohong; Liu, Zongli; Ding, Yongkun

2004-08-01

331

A high-sugar diet produces obesity and insulin resistance in wild-type Drosophila  

PubMed Central

SUMMARY Insulin-resistant, ‘type 2’ diabetes (T2D) results from a complex interplay between genes and environment. In particular, both caloric excess and obesity are strongly associated with T2D across many genetic backgrounds. To gain insights into how dietary excess affects insulin resistance, we studied the simple model organism Drosophila melanogaster. Larvae reared on a high-sugar diet were hyperglycemic, insulin resistant and accumulated fat – hallmarks of T2D – compared with those reared on control diets. Excess dietary sugars, but not fats or proteins, elicited insulin-resistant phenotypes. Expression of genes involved in lipogenesis, gluconeogenesis and ?-oxidation was upregulated in high-sugar-fed larvae, as were FOXO targets, consistent with known mechanisms of insulin resistance in humans. These data establish a novel Drosophila model of diet-induced insulin resistance that bears strong similarity to the pathophysiology of T2D in humans.

Musselman, Laura Palanker; Fink, Jill L.; Narzinski, Kirk; Ramachandran, Prasanna Venkatesh; Hathiramani, Sumitha Sukumar; Cagan, Ross L.; Baranski, Thomas J.

2011-01-01

332

Quantified high-throughput screening of Escherichia coli producing poly(3-hydroxybutyrate) based on FACS.  

PubMed

Here, we report on a highly sensitive method for the detection of P(3HB) accumulation in Escherichia coli cells based on the automated flow cytometry system using fluorescent dyes. E. coli containing P(3HB) were stained with either BODIPY or Nile red fluorescent dye, and their staining properties were analyzed under a variety of conditions. Compared with Nile red, BODIPY was much more sensitive in staining P(3HB) and overall demonstrated a more rapid staining of cells, a greater resistance to photobleaching, and greater cell viability. In addition, we also successfully monitored heterogeneity in P(3HB) accumulation within a cell population using BODIPY staining and flow cytometry. We believe this optimized staining method using BODIPY in combination with screening by high-speed flow cytometer will be helpful in the engineering of host cells toward an enhanced production of bioplastics. PMID:23740474

Lee, Jae Hyung; Lee, Seung Hwan; Yim, Sung Sun; Kang, Kyoung-Hee; Lee, Sang Yup; Park, Si Jae; Jeong, Ki Jun

2013-08-01

333

STUDY OF REACTIONS BETWEEN HIGHLY FUNCTIONALIZED LOW MOLECULAR WEIGHT POLYETHYLENE AND POLYAMINES TO PRODUCE THERMOSET MATERIALS  

Microsoft Academic Search

Low molecular weight functionalized polyolefins are mainly used as additives in adhesive formulations, compatibilizing agents and aqueous dispersions. However, the low viscosity and functionality they offer has never been explored to generate high molecular weight products that offer improved processing routes for polyolefins as well as wider applications.\\u000aThe aim of this thesis work was to investigate the preparation and

Tayyab Hameed

2012-01-01

334

Measurement of Forward Jets Produced in High-Transverse-Momentum Hadron-Proton Collisions  

Microsoft Academic Search

A measurement of charged-particle production is reported for the forward region in events triggered by high-transverse-momentum (p?) jets and single particles. The momentum distributions of forward-going particles are observed to scale in a simple p?-dependent longitudinal variable. Forward-going (beam) jets are observed to be tilted away from the original direction by an amount which agrees with muon-pair data when interpreted

C. Bromberg; G. Fox; R. Gomez; J. Pine; J. Rohlf; S. Stampke; K. Yung; S. Erhan; E. Lorenz; M. Medinnis; P. Schlein; V. Ashford; H. Haggerty; R. Juhala; E. Malamud; S. Mori; R. Abrams; R. Delzenero; H. Goldberg; S. Margulies; D. McLeod; J. Solomon; R. Stanek; A. Dzierba; W. Kropac

1980-01-01

335

False positive reactivity of recombinant, diagnostic, glycoproteins produced in High Five™ insect cells: Effect of glycosylation  

Microsoft Academic Search

Baculovirus-mediated expression of recombinant proteins for use in diagnostic assays is commonplace. We expressed a diagnostic antigen for cysticercosis, GP50, caused by the larval stage of Taenia solium, in both High Five™ and Sf9 insect cells. Upon evaluation of the specificity of recombinant GP50 (rGP50) in a western blot assay, we observed that 12.5% (21\\/168) of the serum samples from

Kathy Hancock; Someet Narang; Sowmya Pattabhi; Melinda L. Yushak; Azra Khan; Seh-ching Lin; Robert Plemons; Michael J. Betenbaugh; Victor C. W. Tsang

2008-01-01

336

Application of x-ray-laser interferometry to study high-density laser-produced plasmas  

Microsoft Academic Search

Collisionally pumped soft-x-ray lasers now operate over a wavelength range extending from 4 to 40 nm. With the recent advances in the development of multilayer mirrors and beam splitters in the soft-x-ray regime, we can utilize the unique properties of x-ray lasers to study large, rapidly evolving laser-driven plasmas with high electron densities. Using a neonlike yttrium x-ray laser, which

A. S. Wan; L. B. da Silva; T. W. Barbee Jr.; R. Cauble; P. Celliers; S. B. Libby; R. A. London; J. C. Moreno; J. E. Trebes; F. Weber

1996-01-01

337

Changes produced in etching parameters of CR39 by high-dose pre- and post-? irradiation  

Microsoft Academic Search

The effect of post- and pre-high doses of ?–radiation in CR-39 plastic detectors has been studied in the dose range of 3×10?10 Gy. Some properties like bulk-etch rate (VB), track-etch rate (VT), sensitivity (VT\\/VB) and efficiency have been found out for different gamma doses from a Co source in CR-39. It is found that VB and VT remain almost invariant up

M. F. Zaki; U. Seddik

2007-01-01

338

Milk Response to Concentrate Supplementation of High Producing Dairy Cows Grazing at Two Pasture Allowances  

Microsoft Academic Search

Twenty multiparous Holstein cows (four ruminally cannulated)infive4 ×4Latinsquareswith21-dperiods were used to study the effect of concentrate supplemen- tation when grazed at two pasture allowances. The four dietary treatments resulted from the combination of two pasture allowance targets (low, 25 vs. high, 40 kg of dry matter\\/cow per day) and two concentrate supple- mentation levels (zero vs. 1 kg of concentrate\\/4

F. Bargo; L. D. Muller; J. E. Delahoy; T. W. Cassidy

2002-01-01

339

Development of Compton radiography using high-Z backlighters produced by ultra-intense lasers  

SciTech Connect

High-energy x-ray backlighters will be valuable for radiography experiments at the National Ignition Facility (NIF), and for radiography of imploded inertial confinement fusion cores using Compton scattering to observe cold, dense plasma. Key considerations are the available backlight brightness, and the backlight size. To quantify these parameters we have characterized the emission from low- and high-Z planar foils irradiated by intense picosecond and femtosecond laser pulses from the TITAN laser facility at Lawrence Livermore National Laboratory. Spectra generated by a sequence of elements from Mo to Pb, spanning the x-ray energy range from 17 keV to 75 keV, have been recorded using a Charged Coupled Device (CCD) in single hit regime and a Dual Crystal Spectrometer (DCS). High-resolution point-projection 2D radiographs have also been recorded on Fuji BaFBr:Eu2 image plates using calibrated resolution grids. We discuss the results in light of the requirements for applications at NIF.

Tommasini, Riccardo; Park, Hye-Sook; Patel, Prav; Maddox, Brian; Le Pape, Sebastien; Hatchett, Stephen P.; Remington, Bruce A.; Key, Michael H.; Izumi, Nobuhiko; Tabak, Max; Koch, Jeffrey A.; Landen, Otto L.; Hey, Dan; MacKinnon, Andy; Seely, John; Holland, Glenn; Hudson, Larry; Szabo, Csilla [Lawrence Livermore National Laboratory, Livermore CA (United States); Naval Research Laboratory, Washington DC (United States); National Institute of Standards and Technology, Gaithersburg, MD (United States)

2007-08-02

340

Producing high sugar concentrations from loblolly pine using wet explosion pretreatment.  

PubMed

We present quantitative analysis of pretreatment for obtaining high conversion and release of sugars from loblolly pine. We use wet explosion (WEx): wet oxidation followed by steam explosion and enzymatic hydrolysis (EH) at high dry matter to solubilize sugars. WEx was conducted at 25% (w/w) solids in presence of oxygen at pressures 6.5-7.2 bar, temperatures 170-175°C and residence time from 20 to 22.5 min. EH of pretreated samples was performed by Cellic® Ctec2 (60 mg protein/g cellulose) and Cellic® Htec2 enzymes (10% of Ctec2) at 50°C for 72 h. At the optimal WEx condition 96% cellulose and nearly 100% hemicellulose yield were obtained. The final concentrations of monomeric sugars were 152 g/L of glucose, 67 g/L of xylose, and 67 g/L of minor sugars (galactose, arabinose and mannose). Compared to previous work WEx seems to be superior for releasing high concentrations of monomeric sugars. PMID:22854131

Rana, Diwakar; Rana, Vandana; Ahring, Birgitte K

2012-10-01

341

Culture of a high-chlorophyll-producing and halotolerant Chlorella vulgaris.  

PubMed

In order to increase the value of freshwater algae as raw ingredients for health foods and feed for seawater-based farmed fish, we sought to breed high-chlorophyll halotolerant Chlorella with the objective of generating strains with both high chlorophyll concentrations (? 5%) and halotolerance (up to 1% NaCl). We used the Chlorella vulgaris K strain in our research institute culture collection and induced mutations with UV irradiation and acriflavine which is known to effect mutations of mitochondrial DNA that are associated with chlorophyll production. Screenings were conducted on seawater-based "For Chlorella spp." (FC) agar medium, and dark-green-colored colonies were visually selected by macroscopic inspection. We obtained a high-chlorophyll halotolerant strain (designated C. vulgaris M-207A7) that had a chlorophyll concentration of 6.7% (d.m.), a level at least three-fold higher than that of K strain. This isolate also exhibited a greater survival rate in seawater that of K strain. PMID:24331982

Nakanishi, Koichi; Deuchi, Keiji

2014-05-01

342

Streptomyces sp. JS520 produces exceptionally high quantities of undecylprodigiosin with antibacterial, antioxidative, and UV-protective properties.  

PubMed

A Gram-positive, red-pigment-producing bacterial strain, designated JS520 was isolated from the pristine sediment from the cave on mountain Miroc in Serbia. Strain was confirmed to belong to Streptomyces genus based on phenotypic and genetic analysis. Streptomyces sp. JS520 has the ability to produce exceptionally high amounts of deep red pigment into both solid and liquid media. Liquid chromatography and mass spectroscopy of the purified pigments revealed the major component to be undecylprodigiosin (93 %) with minor component being oxidatively cyclized derivative. The pigment production was affected by medium composition, temperature, pH, and the aeration rate. By medium optimization, yields of undecylprodigiosin of 138 mg l(-1) were achieved, what is the highest level of undecylprodigiosin production reported for the members of Gram-positive Streptomyces genus. Purified pigment had antimicrobial properties against bacterial Bacillus and Micrococcus species (50 ?g ml(-1)) and against Candida albicans species (100-200 ?g ml(-1) range). The ability to affect auto-oxidation of the linoleic acid was demonstrated for the purified undecylprodigiosin, suggesting antioxidative properties of this pigment. Multiple ecophysiological roles of the pigment were revealed by comparing cultures grown under pigment-producing and pigment-nonproducing conditions. Cells grown under undecylprodigiosin-producing conditions could tolerate presence of hydrogen peroxide exhibiting three times smaller zones of inhibition at 100 mM H(2)O(2). Undecylprodigiosin-producing cells were also less susceptible to tetracycline, kanamycin, chloramphenicol, and 8-hydroxyquinoline. While the growth of the cells not producing pigment was completely inhibited by 15 min of exposure to ultraviolet light (254 nm), cells producing undecylprodigiosin and cells supplied with purified pigment in vitro showed survival rates at 22 and 8 %, respectively. PMID:22767180

Stankovic, Nada; Radulovic, Vanja; Petkovic, Milos; Vuckovic, Ivan; Jadranin, Milka; Vasiljevic, Branka; Nikodinovic-Runic, Jasmina

2012-12-01

343

A tetracycline-regulated cell line produces high-titer lentiviral vectors that specifically target dendritic cells.  

PubMed

Lentiviral vectors (LVs) are a powerful means of delivering genetic material to many types of cells. Because of safety concerns associated with these HIV-1 derived vectors, producing large quantities of LVs is challenging. In this paper, we report a method for producing high titers of self-inactivating LVs. We retrovirally transduce the tet-off stable producer cell line GPR to generate a cell line, GPRS, which can express all the viral components, including a dendritic cell-specific glycoprotein, SVGmu. Then, we use concatemeric DNA transfection to transfect the LV transfer plasmid encoding a reporter gene GFP in combination with a selectable marker. Several of the resulting clones can produce LV at a titer 10-fold greater than what we achieve with transient transfection. Plus, these viruses efficiently transduce dendritic cells in vitro and generate a strong T cell immune response to our reporter antigen. This method may be a good option for producing strong LV-based vaccines for clinical studies of cancer or infectious diseases. PMID:23851977

Bryson, Paul D; Zhang, Chupei; Lee, Chi-Lin; Wang, Pin

2013-01-01

344

High-stearic and High-oleic cottonseed oils produced by hairpin RNA-mediated post-transcriptional gene silencing.  

PubMed

We have genetically modified the fatty acid composition of cottonseed oil using the recently developed technique of hairpin RNA-mediated gene silencing to down-regulate the seed expression of two key fatty acid desaturase genes, ghSAD-1-encoding stearoyl-acyl-carrier protein Delta 9-desaturase and ghFAD2-1-encoding oleoyl-phosphatidylcholine omega 6-desaturase. Hairpin RNA-encoding gene constructs (HP) targeted against either ghSAD-1 or ghFAD2-1 were transformed into cotton (Gossypium hirsutum cv Coker 315). The resulting down-regulation of the ghSAD-1 gene substantially increased stearic acid from the normal levels of 2% to 3% up to as high as 40%, and silencing of the ghFAD2-1 gene resulted in greatly elevated oleic acid content, up to 77% compared with about 15% in seeds of untransformed plants. In addition, palmitic acid was significantly lowered in both high-stearic and high-oleic lines. Similar fatty acid composition phenotypes were also achieved by transformation with conventional antisense constructs targeted against the same genes, but at much lower frequencies than were achieved with the HP constructs. By intercrossing the high-stearic and high-oleic genotypes, it was possible to simultaneously down-regulate both ghSAD-1 and ghFAD2-1 to the same degree as observed in the individually silenced parental lines, demonstrating for the first time, to our knowledge, that duplex RNA-induced posttranslational gene silencing in independent genes can be stacked without any diminution in the degree of silencing. The silencing of ghSAD-1 and/or ghFAD2-1 to various degrees enables the development of cottonseed oils having novel combinations of palmitic, stearic, oleic, and linoleic contents that can be used in margarines and deep frying without hydrogenation and also potentially in high-value confectionery applications. PMID:12177486

Liu, Qing; Singh, Surinder P; Green, Allan G

2002-08-01

345

Measurement of forward jets produced in high--transverse-momentum hadron-proton collisions  

SciTech Connect

A measurement of charged-particle production is reported for the forward region in events triggered by high--transverse-momentum (p/sub perpendicular/) jets and single particles. The momentum distributions of forward-going particles are observed to scale in a simple p/sub perpendicular/-dependent longitudinal variable. Forward-going (beam) jets are observed to be tilted away from the original direction by an amount which agrees with muon-pair data when interpreted in a parton (quantum-chromodynamics) model.

Bromberg, C.; Fox, G.; Gomez, R.; Pine, J.; Rohlf, J.; Stampke, S.; Yung, K.; Erhan, S.; Lorenz, E.; Medinnis, M.; Schlein, P.; Ashford, V.; Haggerty, H.; Juhala, R.; Malamud, E.; Mori, S.; Abrams, R.; Delzenero, R.; Goldberg, H.; Margulies, S.; McLeod, D.; Solomon, J.; Stanek, R.; Dzierba, A.; Kropac, W.

1980-09-08

346

A promising plasmatron-produced highly ionized plasma source for research\\/industrial demand  

Microsoft Academic Search

Presents the design features and basic parameters of an industrially important plasma jets source developed from a high-current arc pasmatron (I<=3D500A, G=3D1-4g\\/s, jet diameter at a minimum-6mm). The system has been realized of to collect and process data on plasma radiation in the 200-950nm region (resolution=3D0.01nm) allowing securing of a great body of information on atomic\\/ionic line characteristics (radiation transition

A. A. Belevtsev; V. F. Chinnov; E. Kh. Isakaev; A. D. Iserov; V. I. Kalinin; V. K. Korolev; A. V. Markin; D. I. Ryazhsky; O. A. Sinkevich; S. A. Tereshkin; A. S. Tyuftyaev

1998-01-01

347

A search for highly ionizing particles produced at the OPAL intersection point at LEP  

NASA Astrophysics Data System (ADS)

We report the results from a search for highly ionizing and magnetically charged particles at the OPAL intersection point at the LEP e+e- storage ring. The search was sensitive to Dirac monopoles with magnetic charge in the range 0.9gD < g < 3.6.gD, where 68.5e?gD. New upper limits are established on the production of monopoles with charge gD and mass up to 45.0 GeV/c2.

Pinfold, J. L.; Du, R.; Kinoshita, K.; Lorazo, B.; Price, B.; Regimbald, M.

1993-10-01

348

Structure and blood compatibility of highly oriented PLA/MWNTs composites produced by solid hot drawing.  

PubMed

Highly oriented poly(lactic acid) (PLA)/multi-walled carbon nanotubes (MWNTs) composites were fabricated through solid hot drawing technology in an effort to improve the mechanical properties and blood biocompatibility of PLA as blood-contacting medical devices. It was found that proper MWNTs content and drawing orientation can improve the tensile strength and modulus of PLA dramatically. With the increase in draw ratio, the cold crystallization peak became smaller, and the glass transition and the melting peak of PLA moved to high temperature, while the crystallinity increased, and the grain size decreased, indicating the stress-induced crystallization of PLA during drawing. MWNTs showed a nucleation effect on PLA, leading to the rise in the melting temperature, increase in crystallinity and reduction of spherulite size for the composites. Moreover, the intensity of (002) diffraction of MWNTs increased with draw ratio, indicating that MWNTs were preferentially aligned and oriented during drawing. Microstructure observation demonstrated that PLA matrix had an ordered fibrillar bundle structure, and MWNTs in the composite tended to align parallel to the drawing direction. In addition, the dispersion of MWNTs in PLA was also improved by orientation. Introduction of MWNTs and drawing orientation could significantly enhance the blood compatibility of PLA by prolonging kinetic clotting time, reducing hemolysis ratio and platelet activation. PMID:23733838

Li, Zhengqiu; Zhao, Xiaowen; Ye, Lin; Coates, Phil; Caton-Rose, Fin; Martyn, Michasel

2014-03-01

349

Time-resolved Thomson scattering on high-intensity laser-produced hot dense helium plasmas  

NASA Astrophysics Data System (ADS)

The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm and hot dense matter states, i.e. systems at solid-like densities and temperatures of one to several hundred eV. Such extreme conditions are relevant for high-energy density studies such as, e.g., in planetary physics and inertial confinement fusion. We consider here a liquid helium jet pumped with a high-intensity optical short-pulse laser that is subsequently probed with brilliant soft x-ray radiation. The optical short-pulse laser generates a strongly inhomogeneous helium plasma which is characterized with particle-in-cell simulations. We derive the respective Thomson scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We observe plasmon modes that are generated in the interior of the target and study their temporal evolution. Such pump-probe experiments are promising tools to measure the important plasma parameters density and temperature. The method described here can be applied to various pump-probe scenarios by combining optical lasers, soft x-rays and hard x-ray sources.

Sperling, P.; Liseykina, T.; Bauer, D.; Redmer, R.

2013-02-01

350

Ablation cleaning techniques for high-power short-pulse laser produced heavy ion targets  

NASA Astrophysics Data System (ADS)

It has become apparent in the last few years that the light ion surface contamination on short-pulse laser targets is a major impediment to the acceleration of heavier target ions. Mitigation strategies have been tested in experiments at the Los Alamos Trident Laser facility using one arm of the Trident laser at 150 ps to ablatively clean a large area of heated targets in a single short that are subsequently irradiated by the Trident 30 TW short-pulse arm to accelerate the bulk target ions to high energies. This process was used on targets consisting of 15 microns of vanadium. The 150 ps pulse rids the rear of the target of its omnipresent surface contamination layer, consisting mainly of water vapor and hydrocarbons, and allows the Trident 30 TW short-pulse arm to illuminate the target and accelerate ions via the Target Normal Sheath Acceleration (TNSA) mechanism. Because this mechanism relies on a laser generated electrostatic sheath, the ions with the lightest charge to mass ratio (i.e. protons) would be accelerated preferentially at the expense of heavier ions. However with the contamination layer removed, and hence the bulk of the available protons, the TNSA mechanism is able to accelerate the bulk material ions to high energies. Our experimental results are discussed and compared to the LASNEX rad-hydro code to validate and improve our predictive capabilities for future acceleration experiments.

Flippo, Kirk A.; Hegelich, B. Manuel; Schmitt, Mark J.; Gauthier, D. Cort; Meserole, Chad A.; Fisher, Gregory L.; Cobble, James A.; Johnson, Randall A.; Letzring, Samuel A.; Fernández, Juan C.; Schollmeier, Marius; Schreiber, Jörg

2006-05-01

351

High stress abrasive wear behavior of some hardfaced surfaces produced by thermal spraying  

NASA Astrophysics Data System (ADS)

Steel surfaces were thermally sprayed with nickel chromium boron (NCB) powder (with and without tungsten carbide) using an oxy-acetylene torch. The sprayed (hard) surfaces and substrate were characterized for abrasive wear properties. Test parameters such as load and sliding distance were varied. A significant improvement in the abrasive wear resistance (inverse of wear rate) was noted for the thermally sprayed surfaces as compared to that of the substrate. Wear surfaces, subsurface regions, and debris were examined in order to ascertain the operating wear mechanisms. Substrate (mild steel), because of its low hardness, suffered severe wear through the cutting, ploughing, and wedging action of the hard abrasive (silicon carbide). Deep cuts on the worn surface, a bulky transfer layer, subsurface cracks, and large-size debris were observed. However, wear was reduced due to high hardness of the layer of NCB powder on the substrate, which resisted the penetration of abrasive into the surface. Presence of tungsten carbide in the layer of NCB powder further reduced the wear of the corresponding specimen because of very high hardness of the tungsten carbide. Shallow wear grooves and finer debris were observed for the NCB coating with and without tungsten carbide. Cutting was the predominating wear mechanism in the case of coatings.

Jha, A. K.; Gachake, Arati; Prasad, B. K.; Dasgupta, Rupa; Singh, M.; Yegneswaran, A. H.

2002-02-01

352

NOD macrophages produce high levels of inflammatory cytokines upon encounter of apoptotic or necrotic cells.  

PubMed

During the development of type 1 diabetes, pancreatic beta-cells are subject to an immune attack, leading to their apoptotic or necrotic cell death. Apoptotic beta-cells are also present during periods of tissue remodeling, such as in early life. Macrophages should clear apoptotic cells silently without production of pro-inflammatory cytokines. The aim of the present study was to investigate the cytokine pattern of NOD macrophages exposed to apoptotic or necrotic cells in vitro. In contrast to the limited response of macrophages from C57BL/6 or NOR mice, NOD macrophages reacted aberrantly to both necrotic and apoptotic cells, with secretion of inappropriately high amounts of IL1beta and TNFalpha. Further exploration of the macrophage behavior showed an excessive response of NOD macrophages when exposed to LPS (high iNOS and IL12p40 levels), accompanied by hyper-activation of NF-kappaB(p65). In contrast, NOD macrophages failed to up-regulate IL1beta and IL12p40 in response to IFNgamma. This failure correlated with low protein levels and a low phosphorylation state of STAT1alpha. We conclude that NOD macrophages have severely aberrant cytokine expression patterns that could contribute to the initiation or continuation of an immune attack towards the pancreatic beta-cells and thus onset and progression of type 1 diabetes. PMID:15236748

Stoffels, K; Overbergh, L; Giulietti, A; Kasran, A; Bouillon, R; Gysemans, C; Mathieu, C

2004-08-01

353

High fat diet produces brain insulin resistance, synaptodendritic abnormalities and altered behavior in mice.  

PubMed

Insulin resistance and other features of the metabolic syndrome are increasingly recognized for their effects on cognitive health. To ascertain mechanisms by which this occurs, we fed mice a very high fat diet (60% kcal by fat) for 17days or a moderate high fat diet (HFD, 45% kcal by fat) for 8weeks and examined changes in brain insulin signaling responses, hippocampal synaptodendritic protein expression, and spatial working memory. Compared to normal control diet mice, cerebral cortex tissues of HFD mice were insulin-resistant as evidenced by failed activation of Akt, S6 and GSK3? with ex-vivo insulin stimulation. Importantly, we found that expression of brain IPMK, which is necessary for mTOR/Akt signaling, remained decreased in HFD mice upon activation of AMPK. HFD mouse hippocampus exhibited increased expression of serine-phosphorylated insulin receptor substrate 1 (IRS1-pS(616)), a marker of insulin resistance, as well as decreased expression of PSD-95, a scaffolding protein enriched in post-synaptic densities, and synaptopodin, an actin-associated protein enriched in spine apparatuses. Spatial working memory was impaired as assessed by decreased spontaneous alternation in a T-maze. These findings indicate that HFD is associated with telencephalic insulin resistance and deleterious effects on synaptic integrity and cognitive behaviors. PMID:24686304

Arnold, Steven E; Lucki, Irwin; Brookshire, Bethany R; Carlson, Gregory C; Browne, Caroline A; Kazi, Hala; Bang, Sookhee; Choi, Bo-Ran; Chen, Yong; McMullen, Mary F; Kim, Sangwon F

2014-07-01

354

TECHNICAL DESIGN NOTE: Reproducible noncontact force spectroscopy for studying molecules  

NASA Astrophysics Data System (ADS)

We developed an alternative method to measure force curves reproducibly by noncontact force spectroscopy for studying molecules. In this method, the force curve is collected without disabling the tip-sample distance feedback thereby in a non-destructive manner. The method can be used when the interaction force versus the tip-sample distance is monotonic and it is useful especially for measuring force curves on organic surfaces. We safely obtained the force curves, which are overlapped with those measured by the conventional method on graphite and lead-phthalocyanine samples in ultra high vacuum.

Hosokawa, Yoshihiro; Kobayashi, Kei; Matsushige, Kazumi; Yamada, Hirofumi

2009-09-01

355

High-strain-rate superplasticity at low temperature in a ZK61 magnesium alloy produced by powder metallurgy  

SciTech Connect

In the present study, superplastic behavior of a pseudo single phase magnesium alloy, ZK61, was investigated at about half the absolute melting point. The material was produced by the P/M route, and had a fine grain size of [approximately]500 nm. It is demonstrated that the P/M ZK61 alloy can behave in a superplastic manner at a high strain rate of 1 [times] 10[sup [minus]2] s[sup [minus]1] albeit at the low temperature.

Watanabe, Hiroyuki; Mukai, Toshiji (Osaka Municipal Technical Research Inst. (Japan)); Mabuchi, Mamoru (National Industrial Research Inst. of Nagoya (Japan)); Higashi, Kenji (Osaka Prefecture Univ., Sakai (Japan). Coll. of Engineering)

1999-06-18

356

Microbial community structure analysis of produced water from a high-temperature North Sea oil-field  

Microsoft Academic Search

Molecular and culture-based methods were used to investigate the microbial diversity in produced water obtained from the high-temperature\\u000a Troll oil formation in the North Sea. 16S rRNA gene libraries were generated from total community DNA, using universal archaeal\\u000a or bacterial oligonucleotide primer sets. Sequence analysis of 88 clones in the bacterial library indicated that they originated\\u000a from members of Firmicutes

Håkon Dahle; Frøydis Garshol; Marit Madsen; Nils-Kåre Birkeland

2008-01-01

357

Deep oxidation of methane using catalysts and carriers produced by self-propagating high-temperature synthesis  

Microsoft Academic Search

The self-propagating high-temperature synthesis (SHS) method has been used to produce a range of oxide catalysts which have been found to be active for deep oxidation of methane. The SHS materials studied include various compositions based on the systems Al–Mn–Mg–O, Mg–Cr–O, Mg–Al–O, Mg–Cr–Al–O and Cu–Cr–O with and without the addition of Cerium oxide and an epoxide additive. Specific compositions of

G Xanthopoulou; G Vekinis

2000-01-01

358

Highly efficient differentiation of human ES cells and iPS cells into mature pancreatic insulin-producing cells  

Microsoft Academic Search

Human pluripotent stem cells represent a potentially unlimited source of functional pancreatic endocrine lineage cells. Here we report a highly efficient approach to induce human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells to differentiate into mature insulin-producing cells in a chemical-defined culture system. The differentiated human ES cells obtained by this approach comprised nearly 25% insulin-positive cells

Donghui Zhang; Wei Jiang; Meng Liu; Xin Sui; Xiaolei Yin; Song Chen; Yan Shi; Hongkui Deng

2009-01-01

359

Purification of trans-astaxanthin from a high-yielding astaxanthin ester-producing strain of the microalga Haematococcus pluvialis  

Microsoft Academic Search

The purification method including extraction, saponification, and separation was established for preparing free trans-astaxanthin from a high-yielding astaxanthin ester-producing strain of the microalga Haematococcus pluvialis which contained 3.67% trans-astaxanthins and 1.35% cis-astaxanthins of the dry cells. Low temperature (5°C) was chosen to minimize the degradation of astaxanthins during saponification, and 94.4% free trans-astaxanthin was obtained from trans-astaxanthin esters after 12

Jian-Ping Yuan; Feng Chen

2000-01-01

360

Local bioprospecting for high-lipid producing microalgal strains to be grown on concentrated municipal wastewater for biofuel production  

Microsoft Academic Search

Mass cultivation of microalgae for biofuel production depends heavily on the performance of the microalgae strains used. In this study, 60 algae-like microorganisms collected from different sampling sites in Minnesota were examined using multi-step screening and acclimation procedures to select high-lipid producing facultative heterotrophic microalgae strains capable of growing on concentrated municipal wastewater (CMW) for simultaneous energy crop production and

Wenguang Zhou; Yecong Li; Min Min; Bing Hu; Paul Chen; Roger Ruan

2011-01-01

361

Factors affecting the occurrence of postpartum prolonged luteal activity in clinically healthy high-producing dairy cows  

Microsoft Academic Search

The objective was to characterize risk factors affecting the occurrence of prolonged luteal phase (PLP) in postpartum, clinically healthy, high-producing dairy cows. Transrectal ultrasound examinations of the reproductive tract were performed twice weekly, from the 1st to 8th wk after calving in 151 multiparous clinically healthy lactating Holstein cows (mean ± SD of peak milk yield = 56.7 ± 7.4

Mojtaba Kafi; Abdolah Mirzaei; Amin Tamadon; Mehdi Saeb

362

Isolation of a novel high erythritol-producing Pseudozyma tsukubaensis and scale-up of erythritol fermentation to industrial level  

Microsoft Academic Search

This study isolated a novel erythritol-producing yeast strain, which is capable of growth at high osmolarity. Characteristics\\u000a of the strain include asexual reproduction by multilateral budding, absence of extracellular starch-like compounds, and a\\u000a negative Diazonium blue B color reaction. Phylogenetic analysis based on the 26S rDNA sequence and physiological analysis\\u000a indicated that the strain belongs to the species Pseudozyma tsukubaensis

Marimuthu Jeya; Kyoung-Mi Lee; Manish Kumar Tiwari; Jung-Soo Kim; Paramasamy Gunasekaran; Sang-Yong Kim; In-Won Kim; Jung-Kul Lee

2009-01-01

363

The Impact of “High-Producer” Interleukin6 Haplotypes on Cardiovascular Morbidity and Mortality in a Kidney Transplant Population  

Microsoft Academic Search

BackgroundAt present, inflammation is considered to be one of the key players in the development and maintenance of atherosclerosis, with ample impact on renal transplant outcomes. Interleukin-6 (IL-6) levels and the underlying genetically determined “high-producer” status impact cardiovascular morbidity and mortality. In end-stage renal disease (ESRD) patients, the role of genetically determined IL-6 differences in cardiovascular and renal outcomes of

B. Krüger; A. Walberer; S. Farkas; F. Tokmak; A. Obed; P. Schenker; B. Henning; H. J. Schlitt; B. K. Krämer; B. Banas

2009-01-01

364

Widespread occurrence of neonicotinoid insecticides in streams in a high corn and soybean producing region, USA  

USGS Publications Warehouse

Neonicotinoid insecticides are of environmental concern, but little is known about their occurrence in surface water. An area of intense corn and soybean production in the Midwestern United States was chosen to study this issue because of the high agricultural use of neonicotinoids via both seed treatments and other forms of application. Water samples were collected from nine stream sites during the 2013 growing season. The results for the 79 water samples documented similar patterns among sites for both frequency of detection and concentration (maximum:median) with clothianidin (75%, 257 ng/L:8.2 ng/L) > thiamethoxam (47%, 185 ng/L: imidacloprid (23%, 42.7 ng/L: <2 ng/L). Neonicotinoids were detected at all nine sites sampled even though the basin areas spanned four orders of magnitude. Temporal patterns in concentrations reveal pulses of neonicotinoids associated with rainfall events during crop planting, suggesting seed treatments as their likely source.

Hladik, Michelle L.; Kolpin, Dana W.; Kuivila, Kathryn M.

2014-01-01

365

On the formation of silicon wires produced by high-energy ion irradiation  

NASA Astrophysics Data System (ADS)

We present a detailed study of simulated and experimentally observed factors which influence the formation of wires in p-type silicon which is irradiated with a high energy, small diameter proton beam, and subsequently electrochemically etched in dilute hydrofluoric acid. A better understanding of the variety of factors influencing wire formation enables a better control of their size, gap between adjacent wires and shape. This addresses a previous limitation in fabricating such structures, such as uncontrollable wire shape and undefined minimum gaps. Furthermore it removes limitations in their application in photonics, such as the difficulty in coupling light between adjacent waveguides, a smearing of the band gap of photonic crystals due to imperfect periodicity, and difficulty in moving the photonic band gap towards near infra-red range. Therefore, the present work allows better control in fabricating components for three dimensional silicon machining and silicon photonics using ion irradiation in conjunction with electrochemical etching.

Dang, Z. Y.; Song, J.; Azimi, S.; Breese, M. B. H.; Forneris, J.; Vittone, E.

2013-02-01

366

Intense high-frequency pressure waves produced with low laser fluences  

NASA Astrophysics Data System (ADS)

Pressure waves generated by laser pulses can permeabilize biological barriers, such as the skin or cellular membranes. The characteristics of the absorbing materials are decisive in determining the shape and amplitude of pressure impulse transients. Based on the physics and photochemistry of light-to-pressure conversion, we generate high intensity broadband ultrasound capable of transiently permeabilizing biological barriers. We show evidence that no damage is done to cells exposed to such pressure waves and that skin recovers its protective function some minutes after exposure to the pressure waves. The ability of the pressure waves to promote transient skin permeabilization is assessed by the increase of transepidermal water loss (TEWL) immediately after the application of pressure waves, and by the full recovery of the skin to the normal TEWL values in the following minutes.

Serpa, Carlos; Sá, Gonçalo F. F.; Arnaut, Luis G.

2012-02-01

367

New Crystal-Growth Methods for Producing Lattice-Matched Substrates for High-Temperature Superconductors  

SciTech Connect

This effort addressed the technical problem of identifying and growing, on a commercial scale, suitable single-crystal substrates for the subsequent deposition of epitaxial thin films of high temperature semiconductors such as GaN/AlN. The lack of suitable lattice-matched substrate materials was one of the major problem areas in the development of semiconducting devices for use at elevated temperatures as well as practical opto-electronic devices based on Al- and GaN technology. Such lattice-matched substrates are necessary in order to reduce or eliminate high concentrations of defects and dislocations in GaN/AlN and related epitaxial thin films. This effort concentrated, in particular, on the growth of single crystals of ZnO for substrate applications and it built on previous ORNL experience in the chemical vapor transport growth of large single crystals of zinc oxide. This combined expertise in the substrate growth area was further complemented by the ability of G. Eres and his collaborators to deposit thin films of GaN on the subject substrates and the overall ORNL capability for characterizing the quality of such films. The research effort consisted of research on the growth of two candidate substrate materials in conjunction with concurrent research on the growth and characterization of GaN films, i.e. the effort combined bulk crystal growth capabilities in the area of substrate production at both ORNL and the industrial partner, Commercial Crystal Growth Laboratories (CCL), Naples, Florida, with the novel thin-film deposition techniques previously developed in the ORNL SSD.

Boatner, L.A.

2008-06-24

368

Technique for the efficient and reproducible fabrication of electromagnetic levitation coils  

NASA Technical Reports Server (NTRS)

A technique has been developed for fabricating electromagnetic induction coils in a reproducible manner. The process utilizes a split mandrel that can be disassembled to remove the mandrel from the coil. The technique has increased coil production rates by a factor of 8 over the freehand winding method. The success rate for producing a functional levitation coil has been increased from 50 percent to 95 percent. The levitation coil designed during this work has successfully levitated and melted a variety of alloys including Cu, Ag, Ag-Ni, Cu-Fe, Fe-C, and Nb-Ge. W was also levitated but not melted at temperatures as high as 2700 C. The highest sample melt temperature achieved was 2400 C for the Nb-Ge samples.

Ethridge, E. C.; Curreri, P. A.; Theiss, J.; Abbaschian, G. J.

1984-01-01

369

Apparatus and method for enhanced chemical processing in high pressure and atmospheric plasmas produced by high frequency electromagnetic waves  

DOEpatents

An apparatus and method for creating high temperature plasmas for enhanced chemical processing of gaseous fluids, toxic chemicals, and the like, at a wide range of pressures, especially at atmospheric and high pressures includes an electro-magnetic resonator cavity, preferably a reentrant cavity, and a wave guiding structure which connects an electro-magnetic source to the cavity. The cavity includes an intake port and an exhaust port, each having apertures in the conductive walls of the cavity sufficient for the intake of the gaseous fluids and for the discharge of the processed gaseous fluids. The apertures are sufficiently small to prevent the leakage of the electro-magnetic radiation from the cavity. Gaseous fluid flowing from the direction of the electro-magnetic source through the guiding wave structure and into the cavity acts on the plasma to push it away from the guiding wave structure and the electro-magnetic source. The gaseous fluid flow confines the high temperature plasma inside the cavity and allows complete chemical processing of the gaseous fluids at a wide range of pressures.

Efthimion, Philip C. (Bedminister, NJ) [Bedminister, NJ; Helfritch, Dennis J. (Flemington, NJ) [Flemington, NJ

1989-11-28

370

Exome capture from saliva produces high quality genomic and metagenomic data  

PubMed Central

Background Targeted capture of genomic regions reduces sequencing cost while generating higher coverage by allowing biomedical researchers to focus on specific loci of interest, such as exons. Targeted capture also has the potential to facilitate the generation of genomic data from DNA collected via saliva or buccal cells. DNA samples derived from these cell types tend to have a lower human DNA yield, may be degraded from age and/or have contamination from bacteria or other ambient oral microbiota. However, thousands of samples have been previously collected from these cell types, and saliva collection has the advantage that it is a non-invasive and appropriate for a wide variety of research. Results We demonstrate successful enrichment and sequencing of 15 South African KhoeSan exomes and 2 full genomes with samples initially derived from saliva. The expanded exome dataset enables us to characterize genetic diversity free from ascertainment bias for multiple KhoeSan populations, including new exome data from six HGDP Namibian San, revealing substantial population structure across the Kalahari Desert region. Additionally, we discover and independently verify thirty-one previously unknown KIR alleles using methods we developed to accurately map and call the highly polymorphic HLA and KIR loci from exome capture data. Finally, we show that exome capture of saliva-derived DNA yields sufficient non-human sequences to characterize oral microbial communities, including detection of bacteria linked to oral disease (e.g. Prevotella melaninogenica). For comparison, two samples were sequenced using standard full genome library preparation without exome capture and we found no systematic bias of metagenomic information between exome-captured and non-captured data. Conclusions DNA from human saliva samples, collected and extracted using standard procedures, can be used to successfully sequence high quality human exomes, and metagenomic data can be derived from non-human reads. We find that individuals from the Kalahari carry a higher oral pathogenic microbial load than samples surveyed in the Human Microbiome Project. Additionally, rare variants present in the exomes suggest strong population structure across different KhoeSan populations.

2014-01-01

371

High energy density plasmas produced by x-ray and extreme ultraviolet lasers  

NASA Astrophysics Data System (ADS)

A comprehensive simulation study is presented, examining the interaction of an EUV capillary discharge laser, operating at 46.9nm, within carbon at solid density. By incorporating a detailed model of photoionization, equation of state calculations, electronic term accounting and refractive index calculation into a pre-existing 2D radiative-hydrodynamic code POLLUX, target ablation and subsequent plasma expansion has been simulated for target material under intense (1011 W cm-2) EUV irradiation. Unique ablation based on direct photoionization by EUV photons creates solid density plasma with a temperature below 20eV. Plasma in this warm dense matter state is of particular interest to inertial con_nement fusion research. A reduction in focal spot size, due to a decrease in the di_raction limit, combined with increased target penetration allows for high-aspect ratio hole drilling and a signi_cant increase in the ejected target mass. This work outlines a comprehensive computational environment used to simulate the EUV/x-ray laser interaction within solid material and expanding plasma.

Rossall, Andrew K.; Aslanyan, Valentin; Tallents, Greg J.

2013-09-01

372

Rhodotorula mucilaginosa, a carotenoid producing yeast strain from a Patagonian high-altitude lake.  

PubMed

The red yeast Rhodotorula mucilaginosa strain CRUB 0138 (previously identified as R. lactosa) was isolated from a high-altitude Patagonian Lake Toncek (1700 m a.s.l.), and assigned with mucilaginosa species. Its biochemical, physiological and molecular features were assessed and compared to R. mucilaginosa PYCC 5166 type strain using a polyphasic approach; in addition, biomass and carotenoid pigment production at different C/N ratios were determined in an incubator shaker. Phenetic characterization by means of 70 current physiological tests including assimilation of aldaric acids and aromatic compounds, and also the ability to grow with amino acids as sole carbon sources, was carried out. According to numerical taxonomy calculations, similarity indexes between R. mucilaginosa CRUB 0138 and PYCC 5166 type strain were 0.86 and 0.77, corresponding to a complete set of physiological tests and MSP-PCR (Mini/Micro Satellite Primed PCR; (GTG)5, M13 and (GAC)5 primers were employed) fingerprinting. Killer activity against 2 native strains, Rhodosporidium kratochvilovae and R. mucilaginosa was detected. Maximum biomass-glucose conversion efficiency (87%) and maximum carotenoid yield (2.32 mg/L) were obtained at C/N = 5 in culture medium containing 10 and 40 g/L glucose, respectively. Different C/N ratios did not influence carotenoid pigment production but low C/N enhanced biomass yield. PMID:15143736

Libkind, D; Brizzio, S; van Broock, M

2004-01-01

373

Plasma Density in a Planar Current Sheet Produced under High-Pressure He-filling  

NASA Astrophysics Data System (ADS)

Formation of current sheets (CS) in 2D magnetic fields with a null-line is usually accompanied by effective plasma compression into planar sheets and in a significant increase in the electron concentration as compared with the initial plasma density. We have demonstrated recently that CS formation is also possible under high-pressure He-filling (300 mTorr), if the radial gradient of magnetic field was strong enough. Now we report the results of spectroscopic measurements on the time evolution of electron concentrations in different regions of CS. In addition, we observed the decay in the He-Ne laser (632.8 nm) intensity because of its refraction in the plasma sheet. So a gradient of electron concentration was obtained. Experiments were carried out with the device CS-3D. Plasma emission from the central part of the CS plasma was analyzed with the standard monochromator and the detector MORS-3 (CCD-line array combined with a microchannel plate). The profiles of He II and He I spectral lines have been recorded at successive stages of the CS evolution and processed using special codes. Plasma density at the CS middle plane increased up to 10E17 per cc, the value exceeded about ten times the initial atomic concentration. Supported by INTAS (grant 96-456) and by RFBR (grant 96- 02-18546).

Kunze, H.-J.; Busher, St.; Frank, A. G.; Kyrie, N. P.

1998-11-01

374

Study of near surface layer of graphite produced by nitrogen ion bombardment at high doses  

NASA Astrophysics Data System (ADS)

To study the modified surface layers of graphites and deposited films of sputtered material, the dependences of sputtering yield Y, and ion-electron emission coefficient gamma on ion incidence angle and target temperature under high dose 30 keV N-2(+) ion irradiation have been measured. In the angular range theta=0-80degrees Y and gamma increase approximately as inverse costheta, Y of POCO-AXF-5Q are 1.5 times larger than of MPG-LT. The dependences of gamma (T) manifests a step-like behaviour typical for the radiation induced phase transitions. EPR analysis shows that at near room temperatures the point electron defects are typical of carbon and the defects due to carbon atoms interacting with N-14 nuclei. At elevated temperatures (greater than or equal to300 degreesC) there are the defects typical of graphite-like structures. The films deposited on glass collectors shows for cold targets only the defects typical of carbon, for the heated graphites - also the defects associated with C-N-14 nuclei interaction.

Bogomolova, L. D.; Borisov, A. M.; Krasil'Nikova, N. A.; Mashkova, E. S.; Nemov, A. S.; Tarasova, V. V.

375

Nitrogen-doped carbon nanotubes with tunable structure and high yield produced by ultrasonic spray pyrolysis  

NASA Astrophysics Data System (ADS)

Nitrogen-doped carbon nanotubes (CN x) were prepared by ultrasonic spray pyrolysis from mixtures of imidazole and acetonitrile. Imidazole, as an additive, was used to control the structure and nitrogen doping in CN x by adjusting its concentration in the mixtures. Scanning electron microscopy observation showed that the addition of imidazole increased the nanotube growth rate and yield, while decreased the nanotube diameter. Transmission electron microscopy study indicated that the addition of imidazole promoted the formation of a dense bamboo-like structure in CN x. X-ray photoelectron spectroscopy analysis demonstrated that the nitrogen content varied from 3.2 to 5.2 at.% in CN x obtained with different imidazole concentrations. Raman spectra study showed that the intensity ratio of D to G bands gradually increased, while that of 2D to G bands decreased, due to increasing imidazole concentration. The yield of CN x made from mixtures of imidazole and acetonitrile can reach 192 mg in 24 min, which is 15 times that of CN x prepared from only acetonitrile. The aligned CN x, with controlled nitrogen doping, tunable structure and high yield, may find applications in developing non-noble catalysts and novel catalyst supports for fuel cells.

Liu, Jian; Zhang, Yong; Ionescu, Mihnea Ioan; Li, Ruying; Sun, Xueliang

2011-06-01

376

Effect of high SARs produced by cell phone like radiofrequency fields on mollusk single neuron.  

PubMed

During exposure to the cell phone electromagnetic field (EMF), some neurons in the brain at areas of peak specific absorption rate (SAR) absorb more electromagnetic energy than is permitted by existing guidelines. The goal of the present work was to investigate the influence of cell phone-like EMF signal on excitability and memory processes in single neurons. A Transverse Electromagnetic Cell (TEM Cell) was used to expose single neurons of mollusk to the EMF. Finite-Difference Time-Domain (FDTD) method was used for modeling the TEM Cell and the EMF interactions with living nerve ganglion and neurons. Neuron electrophysiology was investigated using standard microelectrode technique. SAR deposited into the single neuron was calculated to be 8.2 W/kg with a temperature increment of 1.21°C. After acute exposure, the threshold of firing of action potentials (AP) was significantly decreased (p ? 0.001). Time of habituation to stimulation with the intracellular current injection was increased (p ? 0.003). These results indicate that acute exposure to EMF at high SARs impairs the ability of neurons to store information. PMID:23046101

Partsvania, B; Sulaberidze, T; Shoshiashvili, L

2013-03-01

377

Application of High-Density DNA Resequencing Microarray for Detection and Characterization of Botulinum Neurotoxin-Producing Clostridia  

PubMed Central

Background Clostridium botulinum and related clostridia express extremely potent toxins known as botulinum neurotoxins (BoNTs) that cause severe, potentially lethal intoxications in humans. These BoNT-producing bacteria are categorized in seven major toxinotypes (A through G) and several subtypes. The high diversity in nucleotide sequence and genetic organization of the gene cluster encoding the BoNT components poses a great challenge for the screening and characterization of BoNT-producing strains. Methodology/Principal Findings In the present study, we designed and evaluated the performances of a resequencing microarray (RMA), the PathogenId v2.0, combined with an automated data approach for the simultaneous detection and characterization of BoNT-producing clostridia. The unique design of the PathogenID v2.0 array allows the simultaneous detection and characterization of 48 sequences targeting the BoNT gene cluster components. This approach allowed successful identification and typing of representative strains of the different toxinotypes and subtypes, as well as the neurotoxin-producing C. botulinum strain in a naturally contaminated food sample. Moreover, the method allowed fine characterization of the different neurotoxin gene cluster components of all studied strains, including genomic regions exhibiting up to 24.65% divergence with the sequences tiled on the arrays. Conclusions/Significance The severity of the disease demands rapid and accurate means for performing risk assessments of BoNT-producing clostridia and for tracing potentials sources of contamination in outbreak situations. The RMA approach constitutes an essential higher echelon component in a diagnostics and surveillance pipeline. In addition, it is an important asset to characterise potential outbreak related strains, but also environment isolates, in order to obtain a better picture of the molecular epidemiology of BoNT-producing clostridia.

Vanhomwegen, Jessica; Berthet, Nicolas; Mazuet, Christelle; Guigon, Ghislaine; Vallaeys, Tatiana; Stamboliyska, Rayna; Dubois, Philippe; Kennedy, Giulia C.; Cole, Stewart T.; Caro, Valerie; Manuguerra, Jean-Claude; Popoff, Michel-Robert

2013-01-01

378

Review of high-throughput techniques for detecting solid phase Transformation from material libraries produced by combinatorial methods  

NASA Technical Reports Server (NTRS)

High-throughput measurement techniques are reviewed for solid phase transformation from materials produced by combinatorial methods, which are highly efficient concepts to fabricate large variety of material libraries with different compositional gradients on a single wafer. Combinatorial methods hold high potential for reducing the time and costs associated with the development of new materials, as compared to time-consuming and labor-intensive conventional methods that test large batches of material, one- composition at a time. These high-throughput techniques can be automated to rapidly capture and analyze data, using the entire material library on a single wafer, thereby accelerating the pace of materials discovery and knowledge generation for solid phase transformations. The review covers experimental techniques that are applicable to inorganic materials such as shape memory alloys, graded materials, metal hydrides, ferric materials, semiconductors and industrial alloys.

Lee, Jonathan A.

2005-01-01

379

T cells of the human intestinal lamina propria are high producers of interleukin-10  

PubMed Central

Background and aim—Some of the recently observed functional features characteristic of immunocompetent cells residing in the human intestinal lamina propria could be mediated by interleukin- 10 (IL-10). To investigate the role of IL-10 in the human intestinal mucosa, the regulation of IL-10 production by lamina propria T lymphocytes (LPL-T) was determined and compared with that of peripheral blood T lymphocytes (PBL-T). ?Methods—Following activation by using different stimuli, IL-10 release by LPL-T and PBL-T into the supernatant was measured by enzyme linked immunosorbent assay (ELISA). In parallel, cell growth was determined by [3H]-thymidine incorporation. ?Results—Neither LPL-T nor PBL-T release IL-10 constitutively. Triggering through CD2 or the T cell receptor (TCR)/CD3 complex in the presence of autologous monocytes induces significantly greater IL-10 secretion by LPL-T than by PBL-T. Engagement of the CD45 receptor enhances IL-10 release and proliferation of CD2 triggered CD45RO+ PBL-T. In contrast, it reduces CD2 induced IL-10 production by LPL-T without altering cell growth significantly. ?Conclusions—Activated LPL-T release relatively high amounts of IL-10. Enhanced IL-10 production by activated LPL-T, in comparison with activated PBL-T, is not only related to the presence of a higher proportion of CD45RO+ T cells in the intestinal lamina propria, but is also caused by increased sensitivity of LPL-T to CD2 co-stimulation. The differential responsiveness of LPL-T, compared with PBL-T, to CD45 engagement demonstrates that CD45 could be involved in the altered CD2 reactivity of LPL-T. ?? Keywords: CD2; CD45; interleukin 10; lamina propria; T cell subsets; T lymphocytes

Braunstein, J; Qiao, L; Autschbach, F; Schurmann, G; Meuer, S

1997-01-01

380

High prevalence of Cfr-producing Staphylococcus species in retail meat in Guangzhou, China  

PubMed Central

Background The emergence and wide distribution of the transferable gene for linezolid resistance, cfr, in staphylococci of human and animal origins is of great concern as it poses a serious threat to the public health. In the present study, we investigated the emergence and presence of the multiresistance gene, cfr, in retail meat sourced from supermarkets and free markets of Guangzhou, China. Results A total of 118 pork and chicken samples, collected from Guangzhou markets, were screened by PCR for cfr. Twenty-two Staphylococcus isolates obtained from 12 pork and 10 chicken samples harbored cfr. The 22 cfr-positive staphylococci isolates, including Staphylococcus equorum (n?=?8), Staphylococcus simulans (n?=?7), Staphylococcus cohnii (n?=?4), and Staphylococcus sciuri (n?=?3), exhibited 17 major SmaI pulsed-field gel electrophoresis (PFGE) patterns. In 14 isolates, cfr was located on the plasmids. Sequence analysis revealed that the genetic structures (including ?tnpA of Tn558, IS21-558, ?tnpB, and tnpC of Tn558, orf138, fexA) of cfr in plasmid pHNTLD18 of a S. sciuri strain and in the plasmid pHNLKJC2 (including rep, ?pre/mob, cfr, pre/mob and partial ermC) of a S. equorum strain were identical or similar to the corresponding regions of some plasmids in staphylococcal species of animal and human origins. Conclusions To the best of our knowledge, this is the first study to report the presence of the multiresistance gene, cfr, in animal meat. A high occurrence of cfr was observed in the tested retail meat samples. Thus, it is important to monitor the presence of cfr in animal foods in China.

2014-01-01

381

Ablation produced using a toroidal High Intensity Focused Ultrasound device is independent of hepatic perfusion  

NASA Astrophysics Data System (ADS)

In the liver, the efficacy of radiofrequency or HIFU ablation is impaired by blood perfusion. This can be overcome by hepatic inflow occlusion using a Pringle manoeuver. Here we report the in vivo evaluation of ablations performed in the liver using a surgical toroidal High Intensity Focused Ultrasound (HIFU) device used during an open procedure with and without hepatic inflow occlusion. The HIFU device was composed of 256 toroidal-shaped emitters working at 3 MHz and an integrated ultrasound imaging probe working at 7.5 MHz. Using an Intermittent Pringle Manoeuver (IPM), thermal ablations were created in three pigs with hepatic inflow occlusion (IPM Group) and in three pigs with normal perfusion (NoIPM Group). The ablations were studied on sonograms, macroscopically and microscopically fourteen days after the treatment. In the NoIPM group, the average coagulated volume obtained after a 40 s total exposure was 7.4+/-3.8 cm3 (2.2-16.6). In the IPM group, the average ablated volume was 6.3+/-2.9 cm3 (2.6-12.1). There was no significant difference between the two groups in terms of ablated volume (p = 0.25), diameter (p = 0.37), or depth (p = 0.61). The data from the present study demonstrated that there is no significant influence of hepatic vascular flow on the size and shape of ablations created with the toroidal-shaped HIFU device that has been used. The HIFU approach presented in this study is characterized by the brevity of the treatment (40 seconds for one ablation of 7 cm3), which makes it possible to reduce treatment dependence on blood perfusion. Ablations obtained with or without a Pringle manoeuver were homogeneous in both groups and were not significantly different in terms of diameter, depth and volumes in the IPM group compared with the NoIPM group.

Melodelima, David; N'djin, William A.; Favre, Julia; Parmentier, Hubert; Rivoire, Michel; Chapelon, Jean Yves

2011-09-01

382

Clospore: a liquid medium for producing high titers of semi-purified spores of Clostridium difficile.  

PubMed

Clostridium difficile continues to cause infections in healthcare and other settings. Its spores survive well indoors and require sporicidal chemicals for infection control. However, proper testing of disinfectants is impeded due to difficulties in obtaining viable spores of high enough quality and titers to meet current regulations for sporicidal claims. A new liquid medium (Clospore) has been developed, based on a systematic review of the compositions of 20 other available media. C. difficile spores grown in the new medium and treated with a mixture of lysozyme and trypsin yielded final suspensions with > 10(9) CFU/mL of viable spores, with a purity of > 91% as tested by spore-staining and phase-contrast microscopy. The spores showed a biological decay rate of about 0.1 log10/month when dried on metal disks and stored indoors (air temperature 23 +/- 2 degrees C; relative humidity 52.76 +/- 15.08%). Heating the purified spore suspensions to 70 degrees C for 10 min to inactivate any vegetative cells showed no spore activation or inactivation. The spores could be stored for at least 14 months either refrigerated (4 degrees C) or frozen (-20 or -80 degrees C) in 50% (v/v) ethanol with virtually no loss in viability. The resistance of the enzyme-treated spores to three levels of sodium hypochlorite (1000, 3000, and 5000 ppm), using a standardized quantitative carrier test, was almost identical to that of the spores concentrated by centrifugation alone. The described procedure has been successfully applied to four standard (ATCC) and six clinical strains of C. difficile. PMID:21563698

Perez, Justo; Springthorpe, V Susan; Sattar, Syed A

2011-01-01

383

Commercial intermediate pressure MALDI ion mobility spectrometry mass spectrometer capable of producing highly charged laserspray ionization ions.  

PubMed

The first examples of highly charged ions observed under intermediate pressure (IP) vacuum conditions are reported using laser ablation of matrix/analyte mixtures. The method and results are similar to those obtained at atmospheric pressure (AP) using laserspray ionization (LSI) and/or matrix assisted inlet ionization (MAII). Electrospray ionization (ESI), LSI, and MAII are methods operating at AP and have been shown, with or without the use of a voltage or a laser, to produce highly charged ions with very similar ion abundance and charge states. A commercial matrix-assisted laser desorption/ionization ion mobility spectrometry (IMS) mass spectrometry (MS) instrument (SYNAPT G2) was used for the IP developments. The necessary conditions for producing highly charged ions of peptides and small proteins at IP appear to be a pressure drop region and the use of suitable matrixes and laser fluence. Ionization to produce these highly charged ions under the low pressure conditions of IP does not require specific heating or a special inlet ion transfer region. However, under the current setup, ubiquitin is the highest molecular weight protein observed. These findings are in accord with the need to provide thermal energy in the pressure drop region, similar to LSI and MAII, to improve sensitivity and extend the types of compounds that produce highly charged ions. The practical utility of IP-LSI in combination with IMS-MS is demonstrated for the analysis of model mixtures composed of a lipid, peptides, and a protein. Further, endogenous multiply charged peptides are observed directly from delipified mouse brain tissue with drift time distributions that are nearly identical in appearance to those obtained from a synthesized neuropeptide standard analyzed by either LSI- or ESI-IMS-MS at AP. Efficient solvent-free gas-phase separation enabled by the IMS dimension separates the multiply charged peptides from lipids that remained on the delipified tissue. Lipid and peptide families are exceptionally well separated because of the ability of IP-LSI to produce multiple charging. PMID:21166462

Inutan, Ellen D; Wang, Beixi; Trimpin, Sarah

2011-02-01

384

Mycobacterium leprae Hsp65 administration reduces the lifespan of aged high antibody producer mice  

PubMed Central

Background Aging process may result in immune modifications that lead to disruption of innate and acquired immunity mechanisms that may induce chronic-degenerative events. The heat shock proteins (Hsp), phylogeneticaly conserved among organisms, present as main function the ability of folding and refolding proteins, but they also are associated with chronic-degenerative disorders. Here were evaluated the role of M. leprae native Hsp65 (WT) and its point-mutated (K409A) on survival and anti-DNA and anti-Hsp65 antibody production of aged genetically selected mice for high (HIII) and low (LIII) antibody production; data from 120- and 270-days old mice (named “adult” or “aged”, respectively) were compared. Results WT Hsp65 administration induces reduction in the mean survival time of adult and aged female HIII mice, this effect being stronger in aged individuals. Surprisingly, the native protein administration increased the survival of aged female LIII when compared to K409A and control groups. No survival differences were observed in aged male mice after Hsp65 proteins inoculation. We observed increase in IgG1 anti-Hsp65 in WT and K409A aged HIII female mice groups and no marked changes in the anti-DNA (adult and aged HIII) and anti-Hsp65 IgG1 or IgG2a isotypes production in adult HIII female and aged male mice. LIII male mice presented increased anti-DNA and anti-Hsp65 IgG2a isotype production after WT or K409A injection, and LIII female groups showed no alterations. Conclusions The results revealed that the WT Hsp65 interferes with survival of aged HIII female mice without involvement of a remarkable IgG1 and IgG2a anti-DNA and anti-Hsp65 antibodies production. The deleterious effects of Hsp65 on survival time in aged HIII female mice could be linked to a gender-effect and are in agreement with those previously reported in lupus-prone mice.

2014-01-01

385

Formation of Highly Twisted Ribbons in a Carboxymethylcellulase Gene-Disrupted Strain of a Cellulose-Producing Bacterium  

PubMed Central

Cellulases are enzymes that normally digest cellulose; however, some are known to play essential roles in cellulose biosynthesis. Although some endogenous cellulases of plants and cellulose-producing bacteria are reportedly involved in cellulose production, their functions in cellulose production are unknown. In this study, we demonstrated that disruption of the cellulase (carboxymethylcellulase) gene causes irregular packing of de novo-synthesized fibrils in Gluconacetobacter xylinus, a cellulose-producing bacterium. Cellulose production was remarkably reduced and small amounts of particulate material were accumulated in the culture of a cmcax-disrupted G. xylinus strain (F2-2). The particulate material was shown to contain cellulose by both solid-state 13C nuclear magnetic resonance analysis and Fourier transform infrared spectroscopy analysis. Electron microscopy revealed that the cellulose fibrils produced by the F2-2 cells were highly twisted compared with those produced by control cells. This hypertwisting of the fibrils may reduce cellulose synthesis in the F2-2 strains.

Sugano, Yasushi; Shoda, Makoto; Sakakibara, Hitoshi; Oiwa, Kazuhiro; Tuzi, Satoru; Imai, Tomoya; Sugiyama, Junji; Takeuchi, Miyuki; Yamauchi, Daisuke

2013-01-01

386

Formation of highly twisted ribbons in a carboxymethylcellulase gene-disrupted strain of a cellulose-producing bacterium.  

PubMed

Cellulases are enzymes that normally digest cellulose; however, some are known to play essential roles in cellulose biosynthesis. Although some endogenous cellulases of plants and cellulose-producing bacteria are reportedly involved in cellulose production, their functions in cellulose production are unknown. In this study, we demonstrated that disruption of the cellulase (carboxymethylcellulase) gene causes irregular packing of de novo-synthesized fibrils in Gluconacetobacter xylinus, a cellulose-producing bacterium. Cellulose production was remarkably reduced and small amounts of particulate material were accumulated in the culture of a cmcax-disrupted G. xylinus strain (F2-2). The particulate material was shown to contain cellulose by both solid-state (13)C nuclear magnetic resonance analysis and Fourier transform infrared spectroscopy analysis. Electron microscopy revealed that the cellulose fibrils produced by the F2-2 cells were highly twisted compared with those produced by control cells. This hypertwisting of the fibrils may reduce cellulose synthesis in the F2-2 strains. PMID:23243308

Nakai, Tomonori; Sugano, Yasushi; Shoda, Makoto; Sakakibara, Hitoshi; Oiwa, Kazuhiro; Tuzi, Satoru; Imai, Tomoya; Sugiyama, Junji; Takeuchi, Miyuki; Yamauchi, Daisuke; Mineyuki, Yoshinobu

2013-03-01

387

Producing highly charged ions without solvent using laserspray ionization: a total solvent-free analysis approach at atmospheric pressure.  

PubMed

First examples of highly charged ions in mass spectrometry (MS) produced from the solid state without using solvent during either sample preparation or mass measurement are reported. Matrix material, matrix/analyte homogenization time and frequency, atmospheric pressure (AP) to vacuum inlet temperature, and mass analyzer ion trap conditions are factors that influence the abundance of the highly charged ions created by laserspray ionization (LSI). LSI, like matrix-assisted laser desorption/ionization (MALDI), uses laser ablation of a matrix/analyte mixture from a surface to produce ions. Preparing the matrix/analyte sample without the use of solvent provides the ability to perform total solvent-free analysis (TSA) consisting of solvent-free ionization and solvent-free gas-phase separation using ion mobility spectrometry (IMS) MS. Peptides and small proteins such as non-?-amyloid components of Alzheimer's disease and bovine insulin are examples in which LSI and TSA were combined to produce multiply charged ions, similar to electrospray ionization, but without the use of solvent. Advantages using solvent-free LSI and IMS-MS include simplicity, rapid data acquisition, reduction of sample complexity, and the potential for an enhanced effective dynamic range. This is achieved by more inclusive ionization and improved separation of mixture components as a result of multiple charging. PMID:21520968

Wang, Beixi; Lietz, Christopher B; Inutan, Ellen D; Leach, Samantha M; Trimpin, Sarah

2011-06-01

388

Collagen solubility testing, a quality assurance step for reproducible electro-spun nano-fibre fabrication. A technical note.  

PubMed

Collagen is the main component of the extra-cellular matrix and has been utilised for numerous clinical applications in many forms and products. However, since collagen remains a natural animal-derived biopolymer, variation between batches should be addressed and minimised to ensure reproducibility of the fabrication process. Recently, electro-spinning of collagen has been introduced as a leading technique for the production of bio-mimetic nano-scale scaffolds for tissue-engineering applications. However, no protocols are available that would allow comparisons of the quality of different collagen raw materials prior to the electro-spinning process. In order to bridge this gap we assessed the solubility of various freeze-dried collagens in 0.5 M acetic acid and analysed the solved collagen by gel electrophoresis. We show that raw material of limited solubility in acetic acid will not render high quality electro-spun nano-fibres using hexafluoropropanol. In particular, insoluble collagen directly failed to produce nano-fibres, collagen of reduced solubility produced fused nano-fibres with limited inter-nano-fibre space, whilst purified type-I collagen of high solubility produced smooth, reproducible nano-fibres. Gel electrophoresis confirmed the amount of solubility, as well as qualitative differences in terms of collagen cross-links and collagen types. We recommend this simple and fast step to save costs and to enhance control over the electro-spinning process of collagen. Furthermore, we believe that the solubility test should be introduced prior to any collagenous matrix preparation in order to ensure reproducibility and accuracy. PMID:18854124

Zeugolis, D I; Li, B; Lareu, R R; Chan, C K; Raghunath, M

2008-01-01

389

High Strength and High Ductility of Ultrafine-Grained, Interstitial-Free Steel Produced by ECAE and Annealing  

NASA Astrophysics Data System (ADS)

Interstitial-free steel (IF steel) underwent severe plastic deformation by equal-channel angular extrusion/pressing (ECAE/P) to improve its strength, and then it was annealed to achieve a good strength-ductility balance. The coarse-grained microstructure of IF steel was refined down to the submicron level after eight-pass ECAE. The ultrafine-grained (UFG) microstructure with high dislocation density brought about substantially improved strength but limited tensile ductility. The limited ductility was attributed to the small, uniform elongation caused by early plastic instability. The annealing at temperatures below 723 K (450 °C) for 1 hour did not lead to remarkable softening, whereas annealing at temperatures up to 923 K (650 °C) resulted in complete softening depending on the development of recrystallization. Therefore, the temperature of approximately 923 K (650 °C) can be considered as a critical recrystallization temperature for UFG IF steel. The annealing at 873 K (600 °C) for different time intervals resulted in different stress-strain response. Uniform tensile elongation increased at the expense of strength with annealing time intervals. After annealing at 873 K (600 °C) for 60 minutes, the yield strength, tensile strength, uniform elongation, and total elongation were found to be 320 MPa, 485 MPa, 15.1 pct, and 33.7 pct, respectively, showing the better combination of strength and ductility compared with cold-rolled samples.

Purcek, Gencaga; Saray, Onur; Karaman, Ibrahim; Maier, Hans J.

2012-06-01

390

Experiences with a new generation of electrically produced radiation sources: High energy, high power electron linear accelerators  

SciTech Connect

AECL Accelerators has built the three highest power 10 MeV industrial electron accelerators in the world. Two are in commercial use, one is operating under demanding conditions in AECL`s laboratories. The new IMPELA{reg_sign}{sup 2} technology is proving more than adequately rugged for industrial use. Experience in financing, facility design, construction, licensing, commissioning and early operation of the IMPELA accelerators is reviewed. The availability of the IMPELA prototype has been 99% over the past 12 months. The first commercial IMPELA has had an availability of 95% in its first six months of operation. Mean-time-to-repair has been four hours. IMPELA`s high power level opens new horizons for the use of electron beams. Currently being treated are medical devices, plastic pellets and formed plastic parts. Future applications will likely include cellulose pulp, wood chips, animal feed, and spices. A large future market in irradiating food awaits commercial development. Similarly large opportunities may exist in the disinfection of medical wastes and the destruction of chemical and biological weapons.

Stirling, A.J.

1994-12-31

391

Compositional, nutritional, and functional characteristics of instant teas produced from low- and high-quality black teas.  

PubMed

Two types of instant teas produced from low- and high-quality black teas were examined for their proximate composition, dietary fiber, minerals, water-soluble vitamins, total phenolic content, various antioxidant assays, phenolics (flavanols, condensed phenolics, and phenolic acids), alkaloids, and carotenoids as well as taste-active compounds (sugars, organic acids, and free amino acids). Some variations, albeit to different extents, were observed (p < 0.05) among these parameters between instant teas produced from low- and high-quality black teas. With respect to proximate composition, carbohydrate was the predominant component (56.68-59.84 g/100 g), followed by protein (19.31-19.86 g/100 g). Ash, moisture, and, to a lesser extent, dietary fiber and fat were also present in both instant teas. Thirteen minerals, four water-soluble vitamins, six flavanols, two alkaloids, three condensed phenolics, one phenolic acid, and one carotenoid were identified. Total phenolic content varied between 17.35 and 17.82 g of gallic acid equivalents (GAE)/100 g instant tea. With regard to antioxidant activities, three different assays such as oxygen radical absorbance capacity (ORAC), trolox equivalent antioxidant capacity (TEAC), and cupric ion reducing antioxidant capacity (CUPRAC) were measured. No significant differences (p > 0.05) in total phenolic, ORAC, TEAC, and CUPRAC contents between low- and high-quality instant teas were observed. With regard to taste-active compounds, 3 sugars, 5 organic acids, and 18 free amino acids were positively identified, of which fructose, tannic acid, and theanine predominated, respectively. The present work suggests that despite some differences, instant teas produced from low- and high-quality black teas should not be distinguished on the basis of their compositional, nutritional, and functional characteristics as well as taste-active compounds. PMID:23837397

Alasalvar, Cesarettin; Pelvan, Ebru; Ozdemir, Kübra Sultan; Kocada?l?, Tolgahan; Mogol, Burçe Ataç; Pasl?, Ayça Ayfer; Ozcan, Nihat; Ozçelik, Beraat; Gökmen, Vural

2013-08-01

392

Produced Particle Rapidity (Pseudorapidity) Distribution in Au--Au and Pb--Pb Collisions at High Energy  

NASA Astrophysics Data System (ADS)

The rapidity (pseudorapidity) distribution of produced particles in high-energy nucleus--nucleus collisions are studied by the thermalized cylinder model. In the calculation, two rapidity (pseudorapidity) distribution formulas for an isotropic thermal source are used. The calculated results are compared with the experimental data of Au--Au collisions at 11.5A and 10.8A GeV/c and Pb--Pb collisions at 158A GeV/c. The formula for rapidity (pseudorapidity) agrees well with data on rapidity (pseudorapidity) distribution, whereas approximating rapidity (pseudorapidity) by pseudorapidity (rapidity) leads to discrepancies in the fragmentation regions. The fit parameter ? y representing the rapidity interval over which isotropic sources are distributed seems to be independent on the kinds of concerned produced particles and the centrality cut in the fitted data.

Liu, Fu-Hu

2001-01-01

393

High prevalence of fecal carriage of extended spectrum ?-lactamase/AmpC-producing Enterobacteriaceae in cats and dogs  

PubMed Central

Extended-spectrum-?-lactamase (ESBL)/AmpC producing Enterobacteriaceae have been reported worldwide amongst isolates obtained from humans, food-producing animals, companion animals, and environmental sources. However, data on prevalence of fecal carriage of ESBL/AmpC producing Enterobacteriaceae in healthy companion animals is limited. This pilot study describes the prevalence of ESBL/AmpC encoding genes in healthy cats and dogs, and cats and dogs with diarrhea. Twenty fecal samples of each group were cultured on MacConkey agar supplemented with 1 mg/L cefotaxime and in LB-enrichment broth supplemented with 1 mg/L cefotaxime, which was subsequently inoculated on MacConkey agar supplemented with 1 mg/L cefotaxime. ESBL/AmpC genes were identified using the Check-Points CT103 micro array kit and subsequently by sequencing analysis. Chromosomal ampC promoter mutations were detected by PCR and sequencing analysis. From the healthy and diarrheic dogs, respectively 45 and 55% were positive for Escherichia coli with reduced susceptibility for cefotaxime. From the healthy and diarrheic cats, the estimated prevalence was respectively 0 and 25%. One diarrheic cat was positive for both reduced susceptible E. coli and Proteus mirabilis. The ESBL/AmpC genes found in this study were mainly blaCTX-M-1, but also blaCTX-M-14, blaCTX-M-15, blaTEM-52-StPaul, blaSHV-12, and blaCMY-2 were detected. This pilot study showed that the prevalence of ESBL/AmpC producing Enterobacteriaceae in healthy and diarrheic dogs, and diarrheic cats was relatively high. Furthermore, the genes found were similar to those found in isolates of both human and food-producing animal origin. However, since the size of this study was relatively small, extrapolation of the data to the general population of cats and dogs should be done with great care.

Hordijk, Joost; Schoormans, Anky; Kwakernaak, Mandy; Duim, Birgitta; Broens, Els; Dierikx, Cindy; Mevius, Dik; Wagenaar, Jaap A.

2013-01-01

394

Comparable High Rates of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli in Birds of Prey from Germany and Mongolia  

PubMed Central

Frequent contact with human waste and liquid manure from intensive livestock breeding, and the increased loads of antibiotic-resistant bacteria that result, are believed to be responsible for the high carriage rates of ESBL-producing E. coli found in birds of prey (raptors) in Central Europe. To test this hypothesis against the influence of avian migration, we initiated a comparative analysis of faecal samples from wild birds found in Saxony-Anhalt in Germany and the Gobi-Desert in Mongolia, regions of dissimilar human and livestock population characteristics and agricultural practices. We sampled a total of 281 wild birds, mostly raptors with primarily north-to-south migration routes. We determined antimicrobial resistance, focusing on ESBL production, and unravelled the phylogenetic and clonal relatedness of identified ESBL-producing E. coli isolates using multi-locus sequence typing (MLST) and macrorestriction analyses. Surprisingly, the overall carriage rates (approximately 5%) and the proportion of ESBL-producers among E. coli (Germany: 13.8%, Mongolia: 10.8%) were similar in both regions. Whereas blaCTX-M-1 predominated among German isolates (100%), blaCTX-M-9 was the most prevalent in Mongolian isolates (75%). We identified sequence types (STs) that are well known in human and veterinary clinical ESBL-producing E. coli (ST12, ST117, ST167, ST648) and observed clonal relatedness between a Mongolian avian ESBL-E. coli (ST167) and a clinical isolate of the same ST that originated in a hospitalised patient in Europe. Our data suggest the influence of avian migratory species in the transmission of ESBL-producing E. coli and challenge the prevailing assumption that reducing human influence alone invariably leads to lower rates of antimicrobial resistance.

Guenther, Sebastian; Aschenbrenner, Katja; Stamm, Ivonne; Bethe, Astrid; Semmler, Torsten; Stubbe, Annegret; Stubbe, Michael; Batsajkhan, Nyamsuren; Glupczynski, Youri; Wieler, Lothar H.; Ewers, Christa

2012-01-01

395

Unacceptably High Error Rates in Vitek 2 Testing of Cefepime Susceptibility in Extended-Spectrum-?-Lactamase-Producing Escherichia coli.  

PubMed

While a lack of concordance is known between gold standard MIC determinations and Vitek 2, the magnitude of the discrepancy and its impact on treatment decisions for extended-spectrum-?-lactamase (ESBL)-producing Escherichia coli are not. Clinical isolates of ESBL-producing E. coli were collected from blood, tissue, and body fluid samples from January 2003 to July 2009. Resistance genotypes were identified by PCR. Primary analyses evaluated the discordance between Vitek 2 and gold standard methods using cefepime susceptibility breakpoint cutoff values of 8, 4, and 2 ?g/ml. The discrepancies in MICs between the methods were classified per convention as very major, major, and minor errors. Sensitivity, specificity, and positive and negative predictive values for susceptibility classifications were calculated. A total of 304 isolates were identified; 59% (179) of the isolates carried blaCTX-M, 47% (143) carried blaTEM, and 4% (12) carried blaSHV. At a breakpoint MIC of 8 ?g/ml, Vitek 2 produced a categorical agreement of 66.8% and exhibited very major, major, and minor error rates of 23% (20/87 isolates), 5.1% (8/157 isolates), and 24% (73/304), respectively. The sensitivity, specificity, and positive and negative predictive values for a susceptibility breakpoint of 8 ?g/ml were 94.9%, 61.2%, 72.3%, and 91.8%, respectively. The sensitivity, specificity, and positive and negative predictive values for a susceptibility breakpoint of 2 ?g/ml were 83.8%, 65.3%, 41%, and 93.3%, respectively. Vitek 2 results in unacceptably high error rates for cefepime compared to those of agar dilution for ESBL-producing E. coli. Clinicians should be wary of making treatment decisions on the basis of Vitek 2 susceptibility results for ESBL-producing E. coli. PMID:24752253

Rhodes, Nathaniel J; Richardson, Chad L; Heraty, Ryan; Liu, Jiajun; Malczynski, Michael; Qi, Chao; Scheetz, Marc H

2014-07-01

396

Psychophysiological responses to pain identify reproducible human clusters.  

PubMed

Pain is a ubiquitous yet highly variable experience. The psychophysiological and genetic factors responsible for this variability remain unresolved. We hypothesised the existence of distinct human pain clusters (PCs) composed of distinct psychophysiological and genetic profiles coupled with differences in the perception and the brain processing of pain. We studied 120 healthy subjects in whom the baseline personality and anxiety traits and the serotonin transporter-linked polymorphic region (5-HTTLPR) genotype were measured. Real-time autonomic nervous system parameters and serum cortisol were measured at baseline and after standardised visceral and somatic pain stimuli. Brain processing reactions to visceral pain were studied in 29 subjects using functional magnetic resonance imaging (fMRI). The reproducibility of the psychophysiological responses to pain was assessed at year. In group analysis, visceral and somatic pain caused an expected increase in sympathetic and cortisol responses and activated the pain matrix according to fMRI studies. However, using cluster analysis, we found 2 reproducible PCs: at baseline, PC1 had higher neuroticism/anxiety scores (P ? 0.01); greater sympathetic tone (P<0.05); and higher cortisol levels (P ? 0.001). During pain, less stimulus was tolerated (P ? 0.01), and there was an increase in parasympathetic tone (P ? 0.05). The 5-HTTLPR short allele was over-represented (P ? 0.005). PC2 had the converse profile at baseline and during pain. Brain activity differed (P ? 0.001); greater activity occurred in the left frontal cortex in PC1, whereas PC2 showed greater activity in the right medial/frontal cortex and right anterior insula. In health, 2 distinct reproducible PCs exist in humans. In the future, PC characterization may help to identify subjects at risk for developing chronic pain and may reduce variability in brain imaging studies. PMID:23714265

Farmer, Adam D; Coen, Steven J; Kano, Michiko; Paine, Peter A; Shwahdi, Mustafa; Jafari, Jafar; Kishor, Jessin; Worthen, Sian F; Rossiter, Holly E; Kumari, Veena; Williams, Steven C R; Brammer, Michael; Giampietro, Vincent P; Droney, Joanne; Riley, Julia; Furlong, Paul L; Knowles, Charles H; Lightman, Stafford L; Aziz, Qasim

2013-11-01

397

Can global chemistry-climate models reproduce air quality extremes?  

NASA Astrophysics Data System (ADS)

We identify and characterize extreme ozone pollution episodes over the USA and EU through a novel analysis of ten years (2000-2010) of surface ozone measurements. An optimal interpolation scheme is developed to create grid-cell averaged values of surface ozone that can be compared with gridded model simulations. In addition, it also allows a comparison of two non-coincident observational networks in the EU. The scheme incorporates techniques borrowed from inverse distance weighting and Kriging. It uses all representative observational site data while still recognizing the heterogeneity of surface ozone. Individual, grid-cell level events are identified as an exceedance of historical percentile (10 worst days in a year, 97.3 percentile). A clustering algorithm is then used to construct the ozone episodes from the individual events. We then test the skill of the high-resolution (100 km) two-year (2005-2006) hindcast from the UCI global chemistry transport model in reproducing the events/episodes identified in the observations using the same identification criteria. Although the UCI CTM has substantial biases in surface ozone, we find that it has considerable skill in reproducing both individual grid-cell level extreme events and their connectedness in space and time with an overall skill of 24% (32%) for the US (EU). The grid-cell level extreme ozone events in both the observations and UCI CTM are found to occur mostly (~75%) in coherent, multi-day, connected episodes covering areas greater than 1000 x 1000 square km. In addition the UCI CTM has greater skill in reproducing these larger episodes. We conclude that even at relatively coarse resolution, global chemistry-climate models can be used to project major synoptic pollution episodes driven by large-scale climate and chemistry changes even with their known biases.

Schnell, J.; Prather, M. J.; Holmes, C. D.

2013-12-01

398

Reproducibility and quantitation of amplicon sequencing-based detection  

PubMed Central

To determine the reproducibility and quantitation of the amplicon sequencing-based detection approach for analyzing microbial community structure, a total of 24 microbial communities from a long-term global change experimental site were examined. Genomic DNA obtained from each community was used to amplify 16S rRNA genes with two or three barcode tags as technical replicates in the presence of a small quantity (0.1% wt/wt) of genomic DNA from Shewanella oneidensis MR-1 as the control. The technical reproducibility of the amplicon sequencing-based detection approach is quite low, with an average operational taxonomic unit (OTU) overlap of 17.2%±2.3% between two technical replicates, and 8.2%±2.3% among three technical replicates, which is most likely due to problems associated with random sampling processes. Such variations in technical replicates could have substantial effects on estimating ?-diversity but less on ?-diversity. A high variation was also observed in the control across different samples (for example, 66.7-fold for the forward primer), suggesting that the amplicon sequencing-based detection approach could not be quantitative. In addition, various strategies were examined to improve the comparability of amplicon sequencing data, such as increasing biological replicates, and removing singleton sequences and less-representative OTUs across biological replicates. Finally, as expected, various statistical analyses with preprocessed experimental data revealed clear differences in the composition and structure of microbial communities between warming and non-warming, or between clipping and non-clipping. Taken together, these results suggest that amplicon sequencing-based detection is useful in analyzing microbial community structure even though it is not reproducible and quantitative. However, great caution should be taken in experimental design and data interpretation when the amplicon sequencing-based detection approach is used for quantitative analysis of the ?-diversity of microbial communities.

Zhou, Jizhong; Wu, Liyou; Deng, Ye; Zhi, Xiaoyang; Jiang, Yi-Huei; Tu, Qichao; Xie, Jianping; Van Nostrand, Joy D; He, Zhili; Yang, Yunfeng

2011-01-01

399

Potential for green microalgae to produce hydrogen, pharmaceuticals and other high value products in a combined process  

PubMed Central

Green microalgae for several decades have been produced for commercial exploitation, with applications ranging from health food for human consumption, aquaculture and animal feed, to coloring agents, cosmetics and others. Several products from green algae which are used today consist of secondary metabolites that can be extracted from the algal biomass. The best known examples are the carotenoids astaxanthin and ?-carotene, which are used as coloring agents and for health-promoting purposes. Many species of green algae are able to produce valuable metabolites for different uses; examples are antioxidants, several different carotenoids, polyunsaturated fatty acids, vitamins, anticancer and antiviral drugs. In many cases, these substances are secondary metabolites that are produced when the algae are exposed to stress conditions linked to nutrient deprivation, light intensity, temperature, salinity and pH. In other cases, the metabolites have been detected in algae grown under optimal conditions, and little is known about optimization of the production of each product, or the effects of stress conditions on their production. Some green algae have shown the ability to produce significant amounts of hydrogen gas during sulfur deprivation, a process which is currently studied extensively worldwide. At the moment, the majority of research in this field has focused on the model organism, Chlamydomonas reinhardtii, but other species of green algae also have this ability. Currently there is little information available regarding the possibility for producing hydrogen and other valuable metabolites in the same process. This study aims to explore which stress conditions are known to induce the production of different valuable products in comparison to stress reactions leading to hydrogen production. Wild type species of green microalgae with known ability to produce high amounts of certain valuable metabolites are listed and linked to species with ability to produce hydrogen during general anaerobic conditions, and during sulfur deprivation. Species used today for commercial purposes are also described. This information is analyzed in order to form a basis for selection of wild type species for a future multi-step process, where hydrogen production from solar energy is combined with the production of valuable metabolites and other commercial uses of the algal biomass.

2013-01-01

400

Dose equivalent near the bone-soft tissue interface from nuclear fragments produced by high-energy protons  

NASA Technical Reports Server (NTRS)

During manned space missions, high-energy nucleons of cosmic and solar origin collide with atomic nuclei of the human body and produce a broad linear energy transfer spectrum of secondary particles, called target fragments. These nuclear fragments are often more biologically harmful than the direct ionization of the incident nucleon. That these secondary particles increase tissue absorbed dose in regions adjacent to the bone-soft tissue interface was demonstrated in a previous publication. To assess radiological risks to tissue near the bone-soft tissue interface, a computer transport model for nuclear fragments produced by high energy nucleons was used in this study to calculate integral linear energy transfer spectra and dose equivalents resulting from nuclear collisions of 1-GeV protons transversing bone and red bone marrow. In terms of dose equivalent averaged over trabecular bone marrow, target fragments emitted from interactions in both tissues are predicted to be at least as important as the direct ionization of the primary protons-twice as important, if recently recommended radiation weighting factors and "worst-case" geometry are used. The use of conventional dosimetry (absorbed dose weighted by aa linear energy transfer-dependent quality factor) as an appropriate framework for predicting risk from low fluences of high-linear energy transfer target fragments is discussed.

Shavers, M. R.; Poston, J. W.; Cucinotta, F. A.; Wilson, J. W.

1996-01-01

401

Multi-Parametric Neuroimaging Reproducibility: A 3T Resource Study  

PubMed Central

Modern MRI image processing methods have yielded quantitative, morphometric, functional, and structural assessments of the human brain. These analyses typically exploit carefully optimized protocols for specific imaging targets. Algorithm investigators have several excellent public data resources to use to test, develop, and optimize their methods. Recently, there has been an increasing focus on combining MRI protocols in multi-parametric studies. Notably, these have included innovative approaches for fusing connectivity inferences with functional and/or anatomical characterizations. Yet, validation of the reproducibility of these interesting and novel methods has been severely hampered by the limited availability of appropriate multi-parametric data. We present an imaging protocol optimized to include state-of-the-art assessment of brain function, structure, micro-architecture, and quantitative parameters within a clinically feasible 60 minute protocol on a 3T MRI scanner. We present scan-rescan reproducibility of these imaging contrasts based on 21 healthy volunteers (11 M/10 F, 22–61 y/o). The cortical gray matter, cortical white matter, ventricular cerebrospinal fluid, thalamus, putamen, caudate, cerebellar gray matter, cerebellar white matter, and brainstem were identified with mean volume-wise reproducibility of 3.5%. We tabulate the mean intensity, variability and reproducibility of each contrast in a region of interest approach, which is essential for prospective study planning and retrospective power analysis considerations. Anatomy was highly consistent on structural acquisition (~1–5% variability), while variation on diffusion and several other quantitative scans was higher (~<10%). Some sequences are particularly variable in specific structures (ASL exhibited variation of 28% in the cerebral white matter) or in thin structures (quantitative T2 varied by up to 73% in the caudate) due, in large part, to variability in automated ROI placement. The richness of the joint distribution of intensities across imaging methods can be best assessed within the context of a particular analysis approach as opposed to a summary table. As such, all imaging data and analysis routines have been made publicly and freely available. This effort provides the neuroimaging community with a resource for optimization of algorithms that exploit the diversity of modern MRI modalities. Additionally, it establishes a baseline for continuing development and optimization of multi-parametric imaging protocols.

Landman, Bennett A.; Huang, Alan J.; Gifford, Aliya; Vikram, Deepti S.; Lim, Issel Anne L.; Farrell, Jonathan A.D.; Bogovic, John A.; Hua, Jun; Chen, Min; Jarso, Samson; Smith, Seth A.; Joel, Suresh; Mori, Susumu; Pekar, James J.; Barker, Peter B.; Prince, Jerry L.; van Zijl, Peter C.M.

2010-01-01

402

High damping Al-Fe-Mo-Si/Zn-Al composites produced by rapidly solidified powder metallurgy process  

SciTech Connect

The metallic materials commonly used in aircraft and aerospace fields, such as aluminum and titanium alloys, steels, etc., show extremely low damping capacity (usually of the order of or less than 10{sup {minus}3}). Thus, some problems related to vibration may emerge and influence the reliability, safety and life of airplanes, satellites, etc. It has been reported that almost two thirds of errors for rockets and satellites are related to vibration and noise. One effective way to solve these vibration-related problems is to adopt high damping metallic materials. Conventional high damping alloys exhibit damping capacity above 10{sup {minus}2}, however, their densities are usually great than 5 x 10{sup 3} kg m{sup {minus}3}, or their strengths are less than 200 MPa (for alloys based on dislocation damping), making them impossible to be applied to aircraft and aerospace areas. Recently, some low-density high-damping metal/metal composites based on aluminum and high damping alloys have been developed in Beijing Institute of Aeronautical Materials (BIAM) by the rapidly solidified power metallurgy process. This paper aims to report the properties of the composites based on a high temperature Al-Fe-Mo-Si alloy and a high damping Zn-Al alloy, and compare them with that of 2618-T61 alloy produced by the ingot metallurgy process.

Li, P.Y.; Dai, S.L.; Chai, S.C.; Li, Y.R.

2000-05-10

403

Neutron-deficient N{approx_equal}126 nuclei produced in 238U fragmentation: population of high-spin states  

SciTech Connect

The population of metastable states produced in relativistic-energy fragmentation of a 238U beam has been measured. For states with high angular momentum, I=17({Dirac_h}/2{pi}) and I=21.5({Dirac_h}/2{pi}), a higher population than expected has been observed, with the discrepancy increasing with angular momentum. By considering two sources for the angular momentum, related to single-particle and collective motions, a much improved description of the experimental results can be obtained. In addition, new results on the structure of 208Fr, 211Ra and 216Ac are reported.

Podolyak, Zs.; Regan, P. H.; Walker, P. M.; Pearson, C. J.; Valiente-Dobon, J. J. [Department of Physics, University of Surrey, Guildford GU2 7XH (United Kingdom); Gerl, J.; Hellstroem, M.; Becker, F.; Gorska, M.; Kelic, A.; Kopatch, Y.; Mandal, S.; Schmidt, K.-H.; Wollersheim, H. J.; Banu, A.; Geissel, H.; Grawe, H.; Kojouharov, I.; Lozeva, R.; Portillo, M. [CSI, Planckstrasse 1, D-64291 Darmstadt (Germany)] (and others)

2006-04-26

404

Development of a high-frequency cold neutron pulser for producing a time-dependent optical potential  

NASA Astrophysics Data System (ADS)

A performance of a high-frequency cold neutron pulser (hf-CNP) consisiting of a Supersendust magnetic mirror and a magnetic coil is tested using TOF method. The test has been done using MINE installed at the C3-1-2 beam hole of the JRR3M in JAERI. “A cold neutron magnetic mirror placed in the pulsed magnetic field” is called a cold neutron pulser(CNP). The switching function of the hf-CNP could be used for producing a time-dependent magnetic potential to a neutron. The result of a test in the frequency range of kHz is reported.

Kawai, Takeshi; Hino, Masahiro; Ebisawa, Toru; Tasaki, Seiji; Yamazaki, Dai; Otake, Yoshie; Shirouzu, Go; Achiwa, Norio

2000-03-01

405

Juvenile female Litomosoides sigmodontis produce an excretory/secretory antigen (Juv-p120) highly modified with dimethylaminoethanol.  

PubMed

A 120 kDa antigen produced by juvenile female Litomosoides sigmodontis (Juv-p120) was isolated and purified. The amino acid composition of the molecule was determined. Juv-p120 was shown to be highly modified with N,N-dimethyl-aminoethanol (28.4 mol%). Treatment of Juv-p120 with potassium hydroxide (beta-elimination) or with sodium m-periodate leads to the destruction of epitopes recognized by antibodies immune affinity-purified with isolated Juv-p120. Juvenile L. sigmodontis were shown to release Juv-p120 into the pleural cavity of infected Mastomys coucha before the onset of patency. PMID:9774792

Hintz, M; Schares, G; Taubert, A; Geyer, R; Zahner, H; Stirm, S; Conraths, F J

1998-09-01

406

A precision translation stage for reproducing measured target volume motions.  

PubMed

The development of 4D imaging, treatment planning and treatment delivery methods for radiation therapy require the use of a high-precision translation stage for testing and validation. These technologies may require spatial resolutions of 1 mm, and temporal resolutions of 2-30 Hz for CT imaging, electromagnetic tracking, and fluoroscopic imaging. A 1D programmable translation stage capable of reproducing idealized and measured anatomic motions common to the thorax has been design and built to meet these spatial and temporal resolution requirement with phantoms weighing up to 27 kg. The stage consists of a polycarbonate base and table, driven by an AC servo motor with encoder feedback by means of a belt-coupled precision screw. Complex motions are possible through a programmable motion controller that is capable of running multiple independent control and monitoring programs concurrently. Programmable input and output ports allow motion to be synchronized with beam delivery and other imaging and treatment delivery devices to within 2.0 ms. Average deviations from the programmed positions are typically 0.2 mm or less, while the average typical maximum positional errors are typically 0.5 mm for an indefinite number of idealized breathing motion cycles and while reproducing measured target volume motions for several minutes. PMID:17712294

Litzenberg, Dale W; Hadley, Scott W; Lam, Kwok L; Balter, James M

2007-01-01

407

Reproducibility of the measurement of sweet taste preferences?  

PubMed Central

Developing interventions to prevent and treat obesity are medical and public health imperatives. Taste is a major determinant of food intake and reliable methods to measure taste preferences need to be established. This study aimed to establish the short-term reproducibility of sweet taste preference measurements using 5-level sucrose concentrations in healthy adult volunteers. We defined sweet taste preference as the geometric mean of the preferred sucrose concentration determined from two series of two-alternative, forced-choice staircase procedures administered 10 min apart on a single day. We repeated the same procedures at a second visit 3–7 days later. Twenty-six adults (13 men and 13 women, age 33.2 ± 12.2 years) completed the measurements. The median number of pairs presented for each series was three (25th and 75th percentiles: 3, 4). The intraclass correlation coefficients between the measurements was 0.82 (95% confidence interval [CI]: 0.63–0.92) within a few days. This study showed high short-term reproducibility of a simple, 5-level procedure for measuring sweet taste preferences. This method may be useful for assessing sweet taste preferences and the risks resulting from those preferences.

Asao, Keiko; Luo, Wendy; Herman, William H.

2014-01-01

408

Residential wire codes: reproducibility and relation with measured magnetic fields  

PubMed Central

OBJECTIVES: To investigate the reproducibility of wire codes to characterise residential power line configurations and to determine the extent to which wire codes provide a proxy measure of residential magnetic field strength in a case-control study of childhood leukaemia conducted in nine states within the United States. METHODS: Misclassification of wire codes was assessed with independent measurements by two technicians for 187 residences. The association between categories of wire code and measured level of magnetic field was evaluated in 858 residences with both a wire code measurement and a 24 hour measurement of the magnetic field in the bedroom. The strength of the association between category of wire code and risk of leukaemia was examined in two regions with different average levels of magnetic field in homes with high cate