Sample records for tandem kappab enhancer

  1. Enhancing Tandem Language Learning Using an Interactive Tabletop

    E-print Network

    Enhancing Tandem Language Learning Using an Interactive Tabletop by Erik Paluka A thesis submitted, then my peer, but most importantly, he turned into my friend. i #12;Abstract Language learning takes a lot of time, patience, and effort. Despite this, there exists many language learning models that help learners

  2. Tandem shock wave cavitation enhancement for extracorporeal lithotripsy

    NASA Astrophysics Data System (ADS)

    Loske, Achim M.; Prieto, Fernando E.; Fernández, Francisco; van Cauwelaert, Javier

    2002-11-01

    Extracorporeal shock wave lithotripsy (ESWL) has been successful for more than twenty years in treating patients with kidney stones. Hundreds of underwater shock waves are generated outside the patient's body and focused on the kidney stone. Stones fracture mainly due to spalling, cavitation and layer separation. Cavitation bubbles are produced in the vicinity of the stone by the tensile phase of each shock wave. Bubbles expand, stabilize and finally collapse violently, creating stone-damaging secondary shock waves and microjets. Bubble collapse can be intensified by sending a second shock wave a few hundred microseconds after the first. A novel method of generating two piezoelectrically generated shock waves with an adjustable time delay between 50 and 950 µs is described and tested. The objective is to enhance cavitation-induced damage to kidney stones during ESWL in order to reduce treatment time. In vitro kidney stone model fragmentation efficiency and pressure measurements were compared with those for a standard ESWL system. Results indicate that fragmentation efficiency was significantly enhanced at a shock wave delay of about 400 and 250 µs using rectangular and spherical stone phantoms, respectively. The system presented here could be installed in clinical devices at relatively low cost, without the need for a second shock wave generator.

  3. Physical interference between escherichia coli RNA polymerase molecules transcribing in tandem enhances abortive synthesis and misincorporation.

    PubMed Central

    Kubori, T; Shimamoto, N

    1997-01-01

    Transcription initiation is accompanied with iterative synthesis and release of short transcripts. The molar ratio of enzyme to template was found to be critical for the amounts and distribution of the abortive products synthesized by Escherichia coli RNA polymerase from several promoters. At a high ratio abortive synthesis of 4-8 nt were enhanced at thelambda P R promoter. Removing excess RNA polymerase just before initiation, achieved by washing immobilized transcription complexes, prevented this enhancement. At this high ratio synthesis of an unexpected 6 nt transcript was enhanced when the enzyme stalled at position +32, but not when it stalled at position +73. This transcript had misincorporations at its fifth and sixth positions, probably due to slippage. Hydroxyl radical footprinting of the complex stalled at +32 in the presence of excess enzyme showed that more than one molecule of RNA polymerase was tandemly bound to the same DNA. These results suggest that: (i) when RNA polymerase molecules are tandemly transcribing the same DNA, transient collisions enhance abortive synthesis by the trailing molecule; (ii) when the leading polymerase stalled in the initially transcribed region blocks progression of the trailing polymerase, the latter can commit misincorporations, probably due to slippage synthesis. PMID:9185576

  4. Surface-up constructed tandem-inverted bilayer cyclodextrins for enhanced enantioseparation and adsorption.

    PubMed

    Zhao, Jie; Lu, Xiaohong; Wang, Yong; Tan, Timothy Thatt Yang

    2014-05-23

    A new generation of triazole-bridged bilayer cyclodextrins (CDs) chiral stationary phase (CSP) material was constructed via a surface-up 'click' approach. The synergistic effect of the tandem-inverted duplex CDs was evidenced by the superior enantioresolution ability toward selected chiral compounds and the enhanced adsorption ability toward hesperetin. The enantioselectivities of dansyl amino acids and aryl carboxylic acids were promoted by 10-20%, while the resolutions of some aryl carboxylic acids were significantly increased from 0 to 3.5 and beyond. Adsorption experiments of hesperetin reveal that the binding ability of the target bilayer CDCSP is nearly 2.8 times than that of the single layer CDCSP. The current work provides a simple and practical approach to design and synthesize novel functional materials with cooperative CD dimers on surfaces. PMID:24720902

  5. Two structurally distinct {kappa}B sequence motifs cooperatively control LPS-induced KC gene transcription in mouse macrophages

    SciTech Connect

    Ohmori, Y.; Fukumoto, S.; Hamilton, T.A. [Cleveland Clinic Foundation, Cleveland, OH (United States)

    1995-10-01

    The mouse KC gene is an {alpha}-chemokine gene whose transcription is induced in mononuclear phagocytes by LPS. DNA sequences necessary for transcriptional control of KC by LPS were identified in the region flanking the transcription start site. Transient transfection analysis in macrophages using deletion mutants of a 1.5-kb sequence placed in front of the chloramphenicol acetyl transferase (CAT) gene identified an LPS-responsive region between residues -104 and +30. This region contained two {kappa}B sequence motifs. The first motif (position -70 to -59, {kappa}B1) is highly conserved in all three human GRO genes and in the mouse macrophage inflammatory protein-2 (MIP-2) gene. The second {kappa}B motif (position -89 to -78, {kappa}B2) was conserved only between the mouse and the rat KC genes. Consistent with previous reports, the highly conserved {kappa}B site ({kappa}B1) was essential for LPS inducibility. Surprisingly, the distal {kappa}B site ({kappa}B2) was also necessary for optimal response; mutation of either {kappa}B site markedly reduced sensitivity to LPS in RAW264.7 cells and to TNF-{alpha} in NIH 3T3 fibroblasts. Although both {kappa}B1 and {kappa}B2 sequences were able to bind members of the Rel homology family, including NF{kappa}B1 (P50), RelA (65), and c-Rel, the {kappa}B1 site bound these factors with higher affinity and functioned more effectively than the {kappa}B2 site in a heterologous promoter. These findings demonstrate that transcriptional control of the KC gene requires cooperation between two {kappa}B sites and is thus distinct from that of the three human GRO genes and the mouse MIP-2 gene. 71 refs., 8 figs.

  6. Performance enhancement of existing two-stage sounding rocket vehicles through the use of tandem booster systems

    NASA Astrophysics Data System (ADS)

    Flores, C. C.; Gurkin, L. W.

    The three-stage Taurus-Nike-Tomahawk launch vehicle is being considered for performance enhancement of the existing Taurus-Tomahawk flight system. In addition, performance enhancement of other existing two-stage launch vehicles is being considered through the use of tandem booster systems. Aeroballistic characteristics of the proposed Taurus-Nike-Tomahawk vehicle are presented, as are overall performance capabilities of other potential three-stage flight systems.

  7. MEASUREMENT OF PYRETHROID RESIDUES IN ENVIRONMENTAL AND FOOD SAMPLES BY ENHANCED SOLVENT EXTRACTION/SUPERCRITICAL FLUID EXTRACTION COUPLED WITH GAS CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    The abstract summarizes pyrethorid methods development research. It provides a summary of sample preparation and analytical techniques such as supercritical fluid extraction, enhance solvent extraction, gas chromatography and tandem mass spectrometry....

  8. Ion mobility tandem mass spectrometry enhances performance of bottom-up proteomics.

    PubMed

    Helm, Dominic; Vissers, Johannes P C; Hughes, Christopher J; Hahne, Hannes; Ruprecht, Benjamin; Pachl, Fiona; Grzyb, Arkadiusz; Richardson, Keith; Wildgoose, Jason; Maier, Stefan K; Marx, Harald; Wilhelm, Mathias; Becher, Isabelle; Lemeer, Simone; Bantscheff, Marcus; Langridge, James I; Kuster, Bernhard

    2014-12-01

    One of the limiting factors in determining the sensitivity of tandem mass spectrometry using hybrid quadrupole orthogonal acceleration time-of-flight instruments is the duty cycle of the orthogonal ion injection system. As a consequence, only a fraction of the generated fragment ion beam is collected by the time-of-flight analyzer. Here we describe a method utilizing postfragmentation ion mobility spectrometry of peptide fragment ions in conjunction with mobility time synchronized orthogonal ion injection leading to a substantially improved duty cycle and a concomitant improvement in sensitivity of up to 10-fold for bottom-up proteomic experiments. This enabled the identification of 7500 human proteins within 1 day and 8600 phosphorylation sites within 5 h of LC-MS/MS time. The method also proved powerful for multiplexed quantification experiments using tandem mass tags exemplified by the chemoproteomic interaction analysis of histone deacetylases with Trichostatin A. PMID:25106551

  9. MAZIE: a Mass and Charge Inference Engine to Enhance Database Searching of Tandem Mass Spectra

    PubMed Central

    Victor, Ken G.; Murgai, Meera; Lyons, Charles E.; Templeton, Thaddeus A. B.; Moshnikov, Sergey A.; Templeton, Dennis J.

    2009-01-01

    Peptide sequence identification using tandem mass spectroscopy remains a major challenge for complex proteomic studies. Peptide matching algorithms require the accurate determination of both the mass and charge of the precursor ion and accommodate uncertainties in these properties by using a wide precursor mass tolerance and by testing, for each spectrum, several possible candidate charges. Using a data acquisition strategy that includes obtaining narrow mass-range MS1 “zoom” scans, we describe here a post-acquisition algorithm dubbed MAZIE, that accurately determines the charge and monoisotopic mass of precursor ions on a low-resolution Thermo LTQ-XL mass spectrometer. This is achieved by examining the isotopic distribution obtained in the preceding MS1 zoom spectrum and comparing to theoretical distributions for candidate charge states from +1 to +4. MAZIE then writes modified data files with the corrected monoisotopic mass and charge. We have validated MAZIE results by comparing the sequence search results obtained with the MAZIE-generated data files to results using the unmodified data files. Using two different search algorithms and a false discovery rate filter, we found that MAZIE-interpreted data resulted in 80% (using SEQUEST) and 30% (using OMSSA) more high-confidence sequence identifications. Analyses of these results indicate that the accurate determination of the precursor ion mass greatly facilitates the ability to differentiate between true and false positive matches, while the determination of the precursor ion charge reduces the overall search time but does not significantly reduce the ambiguity of interpreting the search results. MAZIE is distributed as an open-source PERL script. PMID:19850495

  10. Correction of errors in tandem mass spectrum extraction enhances phosphopeptide identification.

    PubMed

    Hao, Piliang; Ren, Yan; Tam, James P; Sze, Siu Kwan

    2013-12-01

    The tandem mass spectrum extraction of phosphopeptides is more difficult and error-prone than that of unmodified peptides due to their lower abundance, lower ionization efficiency, the cofragmentation with other high-abundance peptides, and the use of MS(3) on MS(2) fragments with neutral losses. However, there are still no established methods to evaluate its correctness. Here we propose to identify and correct these errors via the combinatorial use of multiple spectrum extraction tools. We evaluated five free and two commercial extraction tools using Mascot and phosphoproteomics raw data from LTQ FT Ultra, in which RawXtract 1.9.9.2 identified the highest number of unique phosphopeptides (peptide expectation value <0.05). Surprisingly, ProteoWizzard (v. 3.0.3476) extracted wrong precursor mass for most MS(3) spectra. Comparison of the top three free extraction tools showed that only 54% of the identified spectra were identified consistently from all three tools, indicating that some errors might happen during spectrum extraction. Manual check of 258 spectra not identified from all three tools revealed 405 errors of spectrum extraction with 7.4% in selecting wrong precursor charge, 50.6% in selecting wrong precursor mass, and 42.1% in exporting MS/MS fragments. We then corrected the errors by selecting the best extracted MGF file for each spectrum among the three tools for another database search. With the errors corrected, it results in the 22.4 and 12.2% increase in spectrum matches and unique peptide identification, respectively, compared with the best single method. Correction of errors in spectrum extraction improves both the sensitivity and confidence of phosphopeptide identification. Data analysis on nonphosphopeptide spectra indicates that this strategy applies to unmodified peptides as well. The identification of errors in spectrum extraction will promote the improvement of spectrum extraction tools in future. PMID:24147958

  11. Enhanced expression of tandem multimers of the antimicrobial peptide buforin II in Escherichia coli by the DEAD-box protein and trxB mutant.

    PubMed

    Lee, J H; Kim, M S; Cho, J H; Kim, S C

    2002-05-01

    The tandem multimeric expression of various peptides has been explored by many researchers. However, expression levels have usually not been proportional to the degree of multimerization. To increase the expression level in Escherichia coli of tandem multimers of a cationic antimicrobial peptide, buforin II, fused to an anionic peptide, we studied the effect of the DEAD-box protein and the trxB mutant on the expression of tandem multimers. An expression vector with a tac promoter was more effective in directing multimeric expression than one with a T7 promoter. The expression level of large multimers was substantially increased with the tac promoter, possibly through stabilization of long transcripts by synchronization of transcription and translation. Coexpression of the DEAD-box protein, an RNA-binding protein, with the T7 expression system increased the expression level of multimers, especially large multimers, due to protection of the long RNA transcripts. In addition, the use of the trxB mutant also enhanced the expression level of tandem multimers, which contain two cysteine residues at both ends of the monomeric unit. It seems that disulfide bonds formed in the multimers in the trxB mutant might help efficient charge neutralization for inclusion body formation of the multimers, resulting in enhancement of expression. Our results show that the expression of multimers can be improved through the stabilization of the long transcripts by the DEAD-box protein or the expression, under an oxidizing environment, of the trxB mutant in which covalent cross-links through disulfide bonds facilitate inclusion body formation of the multimeric fusion peptide. PMID:12021800

  12. Tandem tracking

    USGS Multimedia Gallery

    Biologist Sabrina Davenport tandem tracks the Lower Missouri River during high water on June 2, 2011.  Two boats (note boat out window) tracking in tandem can detect fish effectively across a wider river and can turn to search behind wing dikes and sandbars where sturgeon can hide during h...

  13. Sage components enhance cell death through nuclear factor kappa-B signaling.

    PubMed

    Deeb, Sally Joseph; El-Baba, Chirine Omar; Hassan, Saadia Bashir; Larsson, Rolf Lennart; Gali-Muhtasib, Hala Uthman

    2011-01-01

    The sage components linalyl acetate (Ly) and alpha-terpineol (Te) exhibit synergistic anti-proliferative effects. We investigated the effects of Ly and Te on NF-kappaB signaling in HCT-116 colon cancer cells. Ly and Te combinations dose-dependently reduced HCT-116 viability at non-cytotoxic concentrations. Combination treatment induced 30%-60% increase in PreG1 through induction of apoptosis and necrosis. DNA binding assays revealed that combination treatment suppressed both basal and TNF-alpha-induced NF-kappaB activation. This suppression correlated with the inhibition of p65 nuclear translocation and IkappaB-alpha degradation. The lack of change in IKK expression levels or inhibition in IkappaB-alpha phosphorylation suggest the involvement of an IKK-independent mechanism. Ly and Te combination was found to downregulate the expression of NF-kappaB-regulated antiapoptotic and proliferative gene products. Separate treatments and drug combinations significantly decreased DNA binding activity of NF-kappaB which led to the potentiation of cell death induced by the colon cancer drugs oxaliplatin and 5-FU. These results indicate that Ly and Te anticancer activities are partly mediated through the suppression of NF-kappaB activation, suggesting their use in combination with chemotherapeutic agents to induce apoptosis. PMID:21196321

  14. Efficient enhancement of hydrogen production by Ag/Cu2O/ZnO tandem triple-junction photoelectrochemical cell

    NASA Astrophysics Data System (ADS)

    Liu, Ying; Ren, Feng; Shen, Shaohua; Fu, Yanming; Chen, Chao; Liu, Chang; Xing, Zhuo; Liu, Dan; Xiao, Xiangheng; Wu, Wei; Zheng, Xudong; Liu, Yichao; Jiang, Changzhong

    2015-03-01

    Highly efficient semiconductor photoelectrodes for solar hydrogen production through photocatalytic water splitting are a promising and challenge solution to solve the energy problems. In this work, Ag/Cu2O/ZnO tandem triple-junction photoelectrode was designed and prepared. An increase of 11 times of photocurrent is achieved in the Ag/Cu2O/ZnO photoelectrode comparing to that of the Cu2O film. The high performance of the Ag/Cu2O/ZnO film is due to the optimized design of the tandem triple-junction structure, where the localized surface Plasmon resonance of Ag and the hetero-junctions efficiently absorb solar energy, produce, and separate electron-hole pairs in the photocathode.

  15. Enhanced fill factor of tandem organic solar cells incorporating a diketopyrrolopyrrole-based low-bandgap polymer and optimized interlayer.

    PubMed

    Wang, Dong Hwan; Kyaw, Aung Ko Ko; Park, Jong Hyeok

    2015-01-01

    We demonstrate that reproducible results can be obtained from tandem solar cells based on the wide-bandgap poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4,7-di-2-thienyl-2',1',3'-benzothiadiazole] (PCDTBT) and the diketopyrrolopyrrole (DPP)-based narrow bandgap polymer (DT-PDPP2T-TT) with a decyltetradecyl (DT) and an electron-rich 2,5-di-2-thienylthieno[3,2-b]thiophene (2T-TT) group fabricated using an optimized interlayer (ZnO NPs/ph-n-PEDOT:PSS) [NPs: nanoparticles; ph-n: pH-neutral PEDOT: poly(3,4-ethylenedioxythiophene); PSS: polystyrene sulfonate]. The tandem cells are fabricated by applying a simple process without thermal annealing. The ZnO NP interlayer operates well when the ZnO NPs are dispersed in 2-methoxyethanol, as no precipitation and chemical reactions occur. In addition to the ZnO NP film, we used neutral PEDOT:PSS as a second interlayer which is not affect to the sequential deposited bulk heterojunction (BHJ) active layer of acidification. The power conversion efficiency (PCE) of a tandem device reaches 7.4?% (open-circuit voltage VOC =1.53?V, short-circuit current density JSC =7.3?mA?cm(-2) , and fill factor FF=67?%). Furthermore, FF is increased to up to 71?% when another promising large bandgap (bandgap ?1.94?eV) polymer (PBnDT-FTAZ) is used. The surface of each layer with nanoscale morphology (BHJ1/ZnO NPs film/ph-n-PEDOT:PSS/BHJ2) was examined by means of AFM analysis during sequential processing. The combination of these factors, efficient DPP-based narrow bandgap material and optimized interlayer, leads to the high FF (average approaches 70?%) and reproducibly operating tandem BHJ solar cells. PMID:25404201

  16. Tandemization of a Subregion of the Enhancer Sequences from SRS 19-6 Murine Leukemia Virus Associated with T-Lymphoid but Not Other Leukemias

    PubMed Central

    Granger, Steven W.; Bundy, Linda M.; Fan, Hung

    1999-01-01

    Most simple retroviruses induce tumors of a single cell type when infected into susceptible hosts. The SRS 19-6 murine leukemia virus (MuLV), which originated in mainland China, induces leukemias of multiple cellular origins. Indeed, infected mice often harbor more than one tumor type. Since the enhancers of many MuLVs are major determinants of tumor specificity, we tested the role of the SRS 19-6 MuLV enhancers in its broad disease specificity. The enhancer elements of the Moloney MuLV (M-MuLV) were replaced by the 170-bp enhancers of SRS 19-6 MuLV, yielding the recombinants ?Mo+SRS+ and ?Mo+SRS? M-MuLV. M-MuLV normally induces T-lymphoid tumors in all infected mice. Surprisingly, when neonatal mice were inoculated with ?Mo+SRS+ or ?Mo+SRS? M-MuLV, all tumors were of T-lymphoid origin, typical of M-MuLV rather than SRS 19-6 MuLV. Thus, the SRS 19-6 MuLV enhancers did not confer the broad disease specificity of SRS 19-6 MuLV to M-MuLV. However, all tumors contained ?Mo+SRS M-MuLV proviruses with common enhancer alterations. These alterations consisted of tandem multimerization of a subregion of the SRS 19-6 enhancers, encompassing the conserved LVb and core sites and adjacent sequences. Moreover, when tumors induced by the parental SRS 19-6 MuLV were analyzed, most of the T-lymphoid tumors had similar enhancer alterations in the same region whereas tumors of other lineages retained the parental SRS 19-6 MuLV enhancers. These results emphasize the importance of a subregion of the SRS 19-6 MuLV enhancer in induction of T-cell lymphoma. The relevant sequences were consistent with crucial sequences for T-cell lymphomagenesis identified for other MuLVs such as M-MuLV and SL3-3 MuLV. These results also suggest that other regions of the SRS 19-6 MuLV genome contribute to its broad leukemogenic spectrum. PMID:10438804

  17. Tandem Fusion of Hepatitis B Core Antigen Allows Assembly of Virus-Like Particles in Bacteria and Plants with Enhanced Capacity to Accommodate Foreign Proteins

    PubMed Central

    Peyret, Hadrien; Gehin, Annick; Thuenemann, Eva C.; Blond, Donatienne; El Turabi, Aadil; Beales, Lucy; Clarke, Dean; Gilbert, Robert J. C.; Fry, Elizabeth E.; Stuart, David I.; Holmes, Kris; Stonehouse, Nicola J.; Whelan, Mike; Rosenberg, William; Lomonossoff, George P.; Rowlands, David J.

    2015-01-01

    The core protein of the hepatitis B virus, HBcAg, assembles into highly immunogenic virus-like particles (HBc VLPs) when expressed in a variety of heterologous systems. Specifically, the major insertion region (MIR) on the HBcAg protein allows the insertion of foreign sequences, which are then exposed on the tips of surface spike structures on the outside of the assembled particle. Here, we present a novel strategy which aids the display of whole proteins on the surface of HBc particles. This strategy, named tandem core, is based on the production of the HBcAg dimer as a single polypeptide chain by tandem fusion of two HBcAg open reading frames. This allows the insertion of large heterologous sequences in only one of the two MIRs in each spike, without compromising VLP formation. We present the use of tandem core technology in both plant and bacterial expression systems. The results show that tandem core particles can be produced with unmodified MIRs, or with one MIR in each tandem dimer modified to contain the entire sequence of GFP or of a camelid nanobody. Both inserted proteins are correctly folded and the nanobody fused to the surface of the tandem core particle (which we name tandibody) retains the ability to bind to its cognate antigen. This technology paves the way for the display of natively folded proteins on the surface of HBc particles either through direct fusion or through non-covalent attachment via a nanobody. PMID:25830365

  18. Enhanced methamphetamine metabolism in rhesus macaque as compared with human: an analysis using a novel method of liquid chromatography with tandem mass spectrometry, kinetic study, and substrate docking.

    PubMed

    Earla, Ravinder; Kumar, Santosh; Wang, Lei; Bosinger, Steven; Li, Junhao; Shah, Ankit; Gangwani, Mohitkumar; Nookala, Anantha; Liu, Xun; Cao, Lu; Jackson, Austin; Silverstein, Peter S; Fox, Howard S; Li, Weihua; Kumar, Anil

    2014-12-01

    Methamphetamine (MA), which remains one of the widely used drugs of abuse, is metabolized by the cytochrome P450 (P450) family of enzymes in humans. However, metabolism of methamphetamine in macaques is poorly understood. Therefore, we first developed and validated a very sensitive liquid chromatography with tandem mass spectrometry (LC-MS/MS) method using solid phase extraction of rhesus plasma with a lower limit of quantitation at 1.09 ng/ml for MA and its metabolites, 4-hydroxy methamphetamine (4-OH MA), amphetamine (AM), 4-OH amphetamine (4-OH AM), and norephedrine. We then analyzed plasma samples of MA-treated rhesus, which showed >10-fold higher concentrations of AM (?29 ng/ml) and 4-OH AM (?28 ng/ml) than MA (?2 ng/ml). Because the plasma levels of MA metabolites in rhesus were much higher than in human samples, we examined MA metabolism in human and rhesus microsomes. Interestingly, the results showed that AM and 4-OH AM were formed more rapidly and that the catalytic efficiency (Vmax/Km) for the formation of AM was ?8-fold higher in rhesus than in human microsomes. We further examined the differences in these kinetic characteristics using three selective inhibitors of each human CYP2D6 and CYP3A4 enzymes. The results showed that each of these inhibitors inhibited both d- and l-MA metabolism by 20%-60% in human microsomes but not in rhesus microsomes. The differences between human and rhesus CYP2D6 and CYP3A4 enzymes were further assessed by docking studies for both d and l-MA. In conclusion, our results demonstrated an enhanced MA metabolism in rhesus compared with humans, which is likely to be caused by differences in MA-metabolizing P450 enzymes between these species. PMID:25301936

  19. Fingerprint enhancement revisited and the effects of blood enhancement chemicals on subsequent profiler Plus fluorescent short tandem repeat DNA analysis of fresh and aged bloody fingerprints.

    PubMed

    Frégeau, C J; Germain, O; Fourney, R M

    2000-03-01

    This study was aimed at determining the effect of seven blood enhancement reagents on the subsequent Profiler Plus fluorescent STR DNA analysis of fresh or aged bloody fingerprints deposited on various porous and nonporous surfaces. Amido Black, Crowle's Double Stain. 1,8-diazafluoren-9-one (DFO), Hungarian Red, leucomalachite green, luminol and ninhydrin were tested on linoleum, glass, metal, wood (pine, painted white), clothing (85% polyester/15% cotton, 65% polyester/35% cotton, and blue denim) and paper (Scott 2-ply and Xerox-grade). Preliminary experiments were designed to determine the optimal blood dilutions to use to ensure a DNA typing result following chemical enhancement. A 1:200 blood dilution deposited on linoleum and enhanced with Crowle's Double Stain generated enough DNA for one to two rounds of Profiler Plus PCR amplification. A comparative study of the DNA yields before and after treatment indicated that the quantity of DNA recovered from bloody fingerprints following enhancement was reduced by a factor of 2 to 12. Such a reduction in the DNA yields could potentially compromise DNA typing analysis in the case of small stains. The blood enhancement chemicals selected were also evaluated for their capability to reveal bloodmarks on the various porous and nonporous surfaces chosen in this study. Luminol. Amido Black and Crowle's Double Stain showed the highest sensitivity of all seven chemicals tested and revealed highly diluted (1:200) bloody fingerprints. Both luminol and Amido Black produced excellent results on both porous and nonporous surfaces, but Crowle's Double Stain failed to produce any results on porous substrates. Hungarian Red, DFO, leucomalachite green and ninhydrin showed lower sensitivities. Enhancement of bloodmarks using any of the chemicals selected, and short-term exposure to these same chemicals (i.e., less than 54 days), had no adverse effects on the PCR amplification of the nine STR systems surveyed (D3S 1358, HumvWA, HumFGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) or of the gender determination marker Amelogenin. The intensity of the fluorescent signals was very similar and the allele size measurements remained constant and identical to those of untreated bloody fingerprints. No additional background fluorescence was noted. Continuous exposure (for 54 days) to two of the seven enhancement chemicals selected (i.e., Crowle's Double Stain and Hungarian Red) slightly reduced the amplification efficiency of the longer STR loci in profiles of fresh and 7 to 14-day-old bloodprints. This suggests that long-term exposure to these chemicals possibly affects the integrity of the DNA molecules. This study indicates that significant evidence can be obtained from fresh or aged bloody fingerprints applied to a variety of absorbent and nonabsorbent surfaces which are exposed to different enhancement chemicals for short or long periods of time. It also reaffirms that PCR STR DNA typing procedures are robust and provide excellent results when used in concert with fluorescence-based detection assays after fingerprint identification has taken place. PMID:10782955

  20. TANDEM: matching proteins with tandem mass spectra

    Microsoft Academic Search

    Robertson Craig; Ronald C. Beavis

    2004-01-01

    ABSTRACT Summary: Tandem mass spectra obtained from fragmenting peptide ions contain some peptide sequence specific information, but often there is not enough information to completely sequence the original peptide. Several proprietary software applications have been developed to attempt to match the spectra with a list of protein sequencesthat may contain the sequence of the peptide. The application TANDEM was writtento

  1. Effect of fluoride on calcium ion concentration and expression of nuclear transcription factor kappa-B ?65 in rat hippocampus.

    PubMed

    Zhang, Jing; Zhu, Wen-Jing; Xu, Xiao-Hong; Zhang, Zi-Gui

    2011-07-01

    The study investigated the neurotoxicity of drinking water fluorosis in rat hippocampus. Just weaning male Sprague-Dawley (SD) rats were given 15, 30, 60 mg/L NaF solution and tap water for 9 months. The calcium ion concentration ([Ca(2+)]) in synaptosomes was measured by double wavelength fluorescence spectrophotometer and the expression level of nuclear transcription factor kappa-B ?65 (NF-?B ?65) in hippocampal CA3 region was measured by immunohistochemistry. The results showed that [Ca(2+)] significantly increased (F = 33.218, P < 0.01) in moderate fluoride group compared with the control group, and the expression level of NF-?B ?65 in CA3 region presented an increasing trend as fluoride concentration increased. These results indicate that increase of synaptosomes [Ca(2+)] and NF-?B ?65 expression level may be the molecular basis of central nervous system damage caused by chronic fluoride intoxication. NF-?B ?65 in CA3 region is probably a target molecule for fluorosis. PMID:20304620

  2. Cellular monitoring of the nuclear factor kappaB pathway for assessment of space environmental radiation.

    PubMed

    Baumstark-Khan, Christa; Hellweg, Christine E; Arenz, Andrea; Meier, Matthias M

    2005-10-01

    A screening assay for the detection of NF-kappaB-dependent gene induction using the destabilized variant of the reporter protein enhanced green fluorescent protein (d2EGFP) is used for assessing the biological effects of accelerated heavy ions as a model of space environmental radiation conditions. The time course of d2EGFP expression and therefore of activation of NF-kappaB-dependent gene expression was measured after treatment with TNFA or after heavy-ion exposure using flow cytometry. The reported experiments clearly show that accelerated argon ions (95 MeV/nucleon, LET 230 keV/microm) induce the NF-kappaB pathway at low particle densities (1-2 particle hits per nucleus), which result in as few as 5-50 induced DSBs per cell. PMID:16187762

  3. In tandem analysis of CLCN1 and SCN4A greatly enhances mutation detection in families with non-dystrophic myotonia

    Microsoft Academic Search

    Jeroen Trip; Gea Drost; Dennis J Verbove; Anneke J van der Kooi; Jan B M Kuks; Nicolette C Notermans; Jan J Verschuuren; Marianne de Visser; Baziel G M van Engelen; Carin G Faber; Ieke B Ginjaar

    2008-01-01

    Non-dystrophic myotonias (NDMs) are caused by mutations in CLCN1 or SCN4A. The purpose of the present study was to optimize the genetic characterization of NDM in The Netherlands by analysing CLCN1 and SCN4A in tandem. All Dutch consultant neurologists and the Dutch Patient Association for Neuromuscular Diseases (Vereniging Spierziekten Nederland) were requested to refer patients with an initial diagnosis of

  4. Tandem hydrofoil system

    Microsoft Academic Search

    Konstantin I. Matveev; Ivan Ivanovich Matveev

    2001-01-01

    A tandem hydrofoil system enables an improvement in the lift-drag ratio of a high-speed ship. The conditions for favorable application of this type of foil structure are determined. The data on hydrofoil boats using a tandem system are presented. The problem of the stability of the vertical plane motion of a hydrofoil with bow and stern foils is considered. The

  5. In tandem analysis of CLCN1 and SCN4A greatly enhances mutation detection in families with non-dystrophic myotonia.

    PubMed

    Trip, Jeroen; Drost, Gea; Verbove, Dennis J; van der Kooi, Anneke J; Kuks, Jan B M; Notermans, Nicolette C; Verschuuren, Jan J; de Visser, Marianne; van Engelen, Baziel G M; Faber, Carin G; Ginjaar, Ieke B

    2008-08-01

    Non-dystrophic myotonias (NDMs) are caused by mutations in CLCN1 or SCN4A. The purpose of the present study was to optimize the genetic characterization of NDM in The Netherlands by analysing CLCN1 and SCN4A in tandem. All Dutch consultant neurologists and the Dutch Patient Association for Neuromuscular Diseases (Vereniging Spierziekten Nederland) were requested to refer patients with an initial diagnosis of NDM for clinical assessment and subsequent genetic analysis over a full year. Based on clinical criteria, sequencing of either CLCN1 or SCN4A was performed. When previously described mutations or novel mutations were identified in the first gene under study, the second gene was not sequenced. If no mutations were detected in the first gene, the second gene was subsequently also analysed. Underlying NDM mutations were explored in 54 families. In total, 20% (8 of 40) of our probands with suspected chloride channel myotonia showed no CLCN1 mutations but subsequent SCN4A screening revealed mutations in all of them. All 14 probands in whom SCN4A was primarily sequenced showed a mutation. In total, CLCN1 mutations were identified in 32 families (59%) and SCN4A in 22 (41%), resulting in a diagnostic yield of 100%. The yield of mutation detection was 93% with three recessive and three sporadic cases not yielding a second mutation. Among these mutations, 13 in CLCN1 and 3 in SCN4A were novel. In conclusion, the current results show that in tandem analysis of CLCN1 and SCN4A affords high-level mutation ascertainment in families with NDM. PMID:18337730

  6. Orthogonal tandem catalysis

    NASA Astrophysics Data System (ADS)

    Lohr, Tracy L.; Marks, Tobin J.

    2015-06-01

    Tandem catalysis is a growing field that is beginning to yield important scientific and technological advances toward new and more efficient catalytic processes. 'One-pot' tandem reactions, where multiple catalysts and reagents, combined in a single reaction vessel undergo a sequence of precisely staged catalytic steps, are highly attractive from the standpoint of reducing both waste and time. Orthogonal tandem catalysis is a subset of one-pot reactions in which more than one catalyst is used to promote two or more mechanistically distinct reaction steps. This Perspective summarizes and analyses some of the recent developments and successes in orthogonal tandem catalysis, with particular focus on recent strategies to address catalyst incompatibility. We also highlight the concept of thermodynamic leveraging by coupling multiple catalyst cycles to effect challenging transformations not observed in single-step processes, and to encourage application of this technique to energetically unfavourable or demanding reactions.

  7. Diagnosing tandem cells

    SciTech Connect

    Hou, J.; Fonash, S.J. [Pennsylvania State Univ., University Park, PA (United States). Electronic Materials and Processing Research Laboratory; Ghosh, M.; Xi, J.; Liu, T.; Kampas, F. [Advanced Photovoltaic Systems Inc., San Bruno, CA (United States)

    1994-12-31

    In this paper the authors report three new diagnostic techniques for identifying problem areas in tandem cells. These techniques can be easily extended to diagnosing triple junction cells. They applied these techniques to diagnose an a-Si:H based tandem cell having an extraordinarily low Voc. As they demonstrated, the assessments of the problem in this cell produced by each of the diagnostic approaches agree well with each other.

  8. Tandem Air Propellers - II

    NASA Technical Reports Server (NTRS)

    Lesley, E. P.

    1939-01-01

    Tests of three-blade, adjustable-pitch counterrotating tandem model propellers, adjusted to absorb equal power at maximum efficiency of the combination, were made at Stanford University. The aerodynamic characteristics, for blade-angle settings of 15, 25, 35, 45, 55, and 65 degrees at 0.75R of the forward propeller and for diameters spacings of 8-1/2, 15 and 30% were compared with those of three-blade and six-blade propellers of the same blade form. It was found that, in order to realize the condition of equal power at maximum efficiency, the blade angles for the rear propeller must be generally less than for the forward propeller, the difference increasing the blade angle. The tests showed that, at maximum efficiency, the tandem propellers absorb about double the power of three-blade propellers and about 8% more power than six-blade propellers having the pitch of the forward propeller of the tandem combination. The maximum efficiency of the tandem propellers was found to be from 2-15% greater than for six-blade propellers, the difference varying directly with blade angle. It was also found that the maximum efficiency of the tandem propellers was greater than that of a three-blade propeller for blade angles at 0.75R of 25 degrees or more. The difference in maximum efficiency again varied directly with blade angle, being about 9% for 65 degrees at 0.75R.

  9. A simple parallel tandem organic solar cell based on metallophthalocyanines

    NASA Astrophysics Data System (ADS)

    Yuen, Avery P.; Hor, Ah-Mee; Preston, John S.; Klenkler, Richard; Bamsey, Nathan M.; Loutfy, Rafik O.

    2011-04-01

    A simple parallel tandem solar cell based on a combination of Zn-phthalocyanine (Pc) and ClInPc has been fabricated and characterized. Compared to a traditional series tandem cell, parallel tandem cells eliminate the need for a semitransparent recombination layer, reducing the complexity of device fabrication while still providing an excellent increase in device performance. Results show a realized broadening of the spectral response and enhancement of the external quantum efficiency as a result of the complementary absorption profiles of ZnPc and ClInPc in the near infrared region. Introduction of a blended ClInPc:C60 layer is shown to more than double the power conversion efficiency of a standard ZnPc/C60 bilayer device (PCE=0.86%). The enhanced performance of the parallel tandem (PCE=1.81%) arises from an increase in both the open circuit voltage and the short circuit current.

  10. Organic Tandem Solar Cells: Design and Formation

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Chao

    In the past decade, research on organic solar cells has gone through an important development stage leading to major enhancements in power conversion efficiency, from 4% to 9% in single-junction devices. During this period, there are many novel processing techniques and device designs that have been proposed and adapted in organic solar-cell devices. One well-known device architecture that helps maximize the solar cell efficiency is the multi-junction tandem solar-cell design. Given this design, multiple photoactive absorbers as subcells are stacked in a monolithic fashion and assembled via series connection into one complete device, known as the tandem solar cell. Since multiple absorbers with different optical energy bandgaps are being applied in one tandem solar-cell device, the corresponding solar cell efficiency is maximized through expanded absorption spectrum and reduced carrier thermalization loss. In Chapter 3, the architecture of solution-processible, visibly transparent solar cells is introduced. Unlike conventional organic solar-cell devices with opaque electrodes (such as silver, aluminum, gold and etc.), the semi-transparent solar cells rely on highly transparent electrodes and visibly transparent photoactive absorbers. Given these two criteria, we first demonstrated the visibly transparent single-junction solar cells via the polymer absorber with near-infrared absorption and the top electrode based on solution-processible silver nanowire conductor. The highest visible transparency (400 ˜ 700 nm) of 65% was achieved for the complete device structure. More importantly, power conversion efficiency of 4% was also demonstrated. In Chapter 4, we stacked two semi-transparent photoactive absorbers in the tandem architecture in order to realize the semi-transparent tandem solar cells. A noticeable performance improvement from 4% to 7% was observed. More importantly, we modified the interconnecting layers with the incorporation of a thin conjugated polyelectrolyte layer functioning as the surface dipole formation layer to provide better electrical contact with the photoactive layer. Due to the effectiveness of the conjugated polyelectrolyte layer, performance improvement was also observed. Furthermore, other issues regarding the semi-transparent tandem solar cells (e.g., photocurrent matching, exterior color tuning, and transparency tuning) are all explored to optimize best performance. In Chapter 5 and 6, the architectures of double- and triple-junction tandem solar cells are explored. Theoretically, triple-junction tandem solar cells with three photoactive absorbers with cascaded energy bandgaps have the potential to achieve higher performance, in comparison with double-junction tandem solar cells. Such expectations can be ascribed to the minimized carrier thermalization loss and further improved light absorption. However, the design of triple-junction solar cells often involves sophisticated multiple layer deposition as well as substantial optimization. Therefore, there is a lack of successful demonstrations of triple-junction solar cells outperforming the double-junction counterparts. To solve the incompatible issues related to the layer deposition in the fabrication, we proposed a novel architecture of inverted-structure tandem solar cells with newly designed interconnecting layers. Our design of interconnecting layers does not only focus on maintaining the orthogonal solution processing advantages, but also provides an excellent compatibility in the energy level alignment to allow different absorber materials to be used. Furthermore, we also explored the light management inside the double- and triple-junction tandem solar cells. The study of light management was carried out through optical simulation method based transfer matrix formalism. The intention is to obtain a balanced photocurrent output from each subcells inside the tandem solar cell, thus the minimal recombination loss at the contact of interconnecting layers and the optimal efficiency can be expected. With help from simulations, we were able to ca

  11. Tandem resonator reflectance modulator

    Microsoft Academic Search

    I. J. Fritz; J. R. Wendt

    1994-01-01

    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and

  12. Tandem mirror fusion research

    SciTech Connect

    Baldwin, D.E.

    1983-12-02

    The tandem mirror program has evolved considerably in the last decade. Of significance is the viable reactor concept embodied in the MARS design. An aggressive experimental program, culminating in the operation of MFTF-B in late 1986, will provide a firm basis for refining the MARS design as necessary for constructing a reactor prototype in the 1990s.

  13. Efficient production of safety-enhanced Escherichia coli ghosts by tandem expression of PhiX 174 mutant gene E and staphylococcal nuclease A gene.

    PubMed

    Zhu, Wenxing; Zhang, Yuyu; Liu, Xinli

    2015-07-01

    The application of bacterial ghosts as vaccines is limited because of their low lysis efficiency and production and the presence of pathogenic islands and/or antibiotic resistance genes within ghost preparations. To overcome these problems, a new lysis plasmid with fusion gene of mutant gene E and staphylococcal nuclease A gene (mE-L-SNA) were constructed and characterized. The new plasmid pBV-mELS could efficiently induce the genetic inactivation of Escherichia coli cultures, accompanied by the intracellular degradation of the genetic material of host cells, devoid of the presence of pathogenic islands and antibiotic resistance genes within ghost preparations. Furthermore, the lysis efficiency of the plasmid pBV-mELS was not affected by bacterial concentration and could reach 99.99995% for E. coli at late-log phase. However, when the 74-bp non-encoding region of the gene mE-L-SNA were deleted or the first T nucleotide of the gene mE-L-SNA were substituted, these resulting genes lost the function of bacteriolysis, which suggested the 74-bp region of the gene mE-L-SNA, especially the first T nucleotide, played a crucial role in enhancement of bacteriolysis. The lysis system with the gene mE-L-SNA had predominance for large-scale production of safety-enhanced bacterial ghosts. The strategy may provide a promising avenue for efficient production of safe bacterial ghost vaccines. PMID:26070687

  14. Tandem resonator reflectance modulator

    DOEpatents

    Fritz, Ian J. (Albuquerque, NM); Wendt, Joel R. (Albuquerque, NM)

    1994-01-01

    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors.

  15. Tandem resonator reflectance modulator

    DOEpatents

    Fritz, I.J.; Wendt, J.R.

    1994-09-06

    A wide band optical modulator is grown on a substrate as tandem Fabry-Perot resonators including three mirrors spaced by two cavities. The absorption of one cavity is changed relative to the absorption of the other cavity by an applied electric field, to cause a change in total reflected light, as light reflecting from the outer mirrors is in phase and light reflecting from the inner mirror is out of phase with light from the outer mirrors. 8 figs.

  16. Steroid Hormone Analysis by Tandem Mass Spectrometry

    PubMed Central

    Soldin, Steven J.; Soldin, Offie P.

    2013-01-01

    BACKGROUND New high-performance liquid chromatography/ tandem mass spectrometry (LC-MS/MS) methods are among the most successful approaches to improve specificity problems inherent in many immunoassays. CONTENT We emphasize problems with immunoassays for the measurement of steroids and review the emerging role of LC-MS/MS in the measurement of clinically relevant steroids. The latest generation of tandem mass spectrometers has superior limits of quantification, permitting omission of previously employed derivatization steps. The measurement of steroid profiles in the diagnosis and treatment of congenital adrenal hyperplasia, adrenal insufficiency, chronic pelvic pain and prostatitis, oncology (breast cancer), and athletes has important new applications. CONCLUSIONS LC-MS/MS now affords the specificity, imprecision, and limits of quantification necessary for the reliable measurement of steroids in human fluids, enhancing diagnostic capabilities, particularly when steroid profiles are available. PMID:19325015

  17. Molecular profiling of giant cell tumor of bone and the osteoclastic localization of ligand for receptor activator of nuclear factor kappaB.

    PubMed

    Morgan, Teresa; Atkins, Gerald J; Trivett, Melanie K; Johnson, Sandra A; Kansara, Maya; Schlicht, Stephen L; Slavin, John L; Simmons, Paul; Dickinson, Ian; Powell, Gerald; Choong, Peter F M; Holloway, Andrew J; Thomas, David M

    2005-07-01

    Giant cell tumor of bone (GCT) is a generally benign, osteolytic neoplasm comprising stromal cells and osteoclast-like giant cells. The osteoclastic cells, which cause bony destruction, are thought to be recruited from normal monocytic pre-osteoclasts by stromal cell expression of the ligand for receptor activator of nuclear factor kappaB (RANKL). This model forms the foundation for clinical trials in GCTs of novel cancer therapeutics targeting RANKL. Using expression profiling, we identified both osteoblast and osteoclast signatures within GCTs, including key regulators of osteoclast differentiation and function such as RANKL, a C-type lectin, osteoprotegerin, and the wnt inhibitor SFRP4. After ex vivo generation of stromal- and osteoclast-enriched cultures, we unexpectedly found that RANKL mRNA and protein were more highly expressed in osteoclasts than in stromal cells, as determined by expression profiling, flow cytometry, immunohistochemistry, and reverse transcriptase-polymerase chain reaction. The expression patterns of molecules implicated in signaling between stromal cells and monocytic osteoclast precursors were analyzed in both primary and fractionated GCTs. Finally, using array-based comparative genomic hybridization, neither GCTs nor the derived stromal cells demonstrated significant genomic gains or losses. These data raise questions regarding the role of RANKL in GCTs that may be relevant to the development of molecularly targeted therapeutics for this disease. PMID:15972958

  18. Nuclear factor {kappa}B (NF{kappa}B) and cyclooxygenase-2 (Cox-2) expression in the irradiated colorectum is associated with subsequent histopathological changes

    SciTech Connect

    Yeoh, Ann S.J. [Department of Medical Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia) and Department of Physiology, School of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, South Australia (Australia)]. E-mail: ann.yeoh@imvs.sa.gov.au; Bowen, Joanne M. [Department of Medical Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Department of Medicine, University of Adelaide, Adelaide, South Australia (Australia); Gibson, Rachel J. [Department of Medical Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Department of Medicine, University of Adelaide, Adelaide, South Australia (Australia); Keefe, Dorothy M.K. [Department of Medical Oncology, Royal Adelaide Hospital, Adelaide, South Australia (Australia); Department of Medicine, University of Adelaide, Adelaide, South Australia (Australia)

    2005-12-01

    Purpose: Recent studies have proposed that mucositis development is the same throughout the gastrointestinal tract (GIT), as it is formed from one structure embryologically. Radiation-induced oral mucositis studies have outlined the key involvement of nuclear factor {kappa}B (NF{kappa}B) and cyclooxygenase-2 (Cox-2) in its pathobiology. The purpose of this study was therefore to investigate the expression of NF{kappa}B and Cox-2 in the irradiated colorectum and to correlate these with the associated histopathologic changes. Methods and Materials: Colorectal tissues from 28 colorectal cancer patients treated with preoperative radiotherapy were analyzed for histopathologic changes using a variety of tissue staining methods. The expression of NF{kappa}B and Cox-2 in these tissues was investigated using immunohistochemistry. Changes in expression of these proteins were then correlated with the histopathologic changes. Results: Radiation therapy caused injury to the normal colorectal tissue surrounding tumor site, particularly around the blood vessels. These changes were reflected in changes in NF{kappa}B and Cox-2 expression. Conclusions: We conclude that different regions of the GIT, the colorectum, and oral cavity have similar underlying mechanisms of radiation-induced mucositis. Understanding these mechanisms will allow new approaches to be developed to specifically target steps in the evolution of alimentary mucositis.

  19. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1994-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched.

  20. Monolithic tandem solar cell

    DOEpatents

    Wanlass, Mark W. (Golden, CO)

    1991-01-01

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surface of the InP substrate, and (c) a second photoactive subcell on the first subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched. The solar cell can be provided as a two-terminal device or a three-terminal device.

  1. Osteopontin is associated with nuclear factor {kappa}B gene expression during tail-suspension-induced bone loss

    SciTech Connect

    Ishijima, Muneaki [Department of Molecular Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, 3-10, Kanda-Surugadai 2-Chome, Chiyoda-Ku, Tokyo 101-0062 (Japan); Ezura, Yoichi [Department of Molecular Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, 3-10, Kanda-Surugadai 2-Chome, Chiyoda-Ku, Tokyo 101-0062 (Japan) and Department of Molecular Biology, Institute of Gerontology, Nippon Medical School, Kawasaki (Japan)]. E-mail: ezura.mph@mril.tmd.ac.jp; Tsuji, Kunikazu [Department of Molecular Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, 3-10, Kanda-Surugadai 2-Chome, Chiyoda-Ku, Tokyo 101-0062 (Japan)] (and others)

    2006-10-01

    Osteoporosis due to unloading-induced bone loss is a critical issue in the modern aging society. Although the mechanisms underlying this phenomenon are largely unknown, osteopontin (OPN) is one of the critical mediators required for unloading-induced bone loss [M. Ishijima, S.R. Rittling, T. Yamashita, K. Tsuji, H. Kurosawa, A. Nifuji, D.T. Denhardt, and M. Noda, Enhancement of osteoclastic bone resorption and suppression of osteoblastic bone formation in response to reduced mechanical stress do not occur in the absence of osteopontin, J Exp Med, 193 (2001) 399-404]. To clarify the molecular bases for OPN actions, we carried out microarray analyses on the genes expressed in the femoral bone marrow cells in wild type and OPN-/- mice. The removal of the mechanical load induced bone loss in wild type, but not in OPN-/- mice, as previously reported. Expression analysis of 9586 cDNAs on a microarray system revealed that OPN deficiency blocked tail-suspension-induced expression of ten genes (group A). This observation was confirmed based on semi-quantitative RT-PCR analyses. On the other hand, expression of four genes (group B) was not altered by tail suspension in wild type but was enhanced in OPN-deficient mice. NF-{kappa}B p105 subunit gene (Nfkb1) was found in group A and Bax in group B. p53 gene expression was upregulated by tail suspension in wild type mice, but it was no longer observed in OPN-/- mice. These data indicate that OPN acts to mediate mechanical stress signaling upstream to the genes encoding apoptosis-related molecules, and its action is associated with alteration of the genes.

  2. Enhanced Nicotine Metabolism in HIV-1–Positive Smokers Compared with HIV-Negative Smokers: Simultaneous Determination of Nicotine and its Four Metabolites in Their Plasma Using a Simple and Sensitive Electrospray Ionization Liquid Chromatography–Tandem Mass Spectrometry Technique

    PubMed Central

    Earla, Ravinder; Ande, Anusha; McArthur, Carole; Kumar, Anil

    2014-01-01

    Smoking is approximately three times more prevalent in HIV-1–positive than HIV-negative individuals in the United States. Nicotine, which is the major constituent of tobacco, is rapidly metabolized mainly by cytochrome P450 (CYP2A6) to many metabolites. In this study, we developed a simple, fast, and sensitive electrospray ionization liquid chromatography–tandem mass spectrometry method using a strong cation solid phase extraction, and determined the concentration of nicotine and its four major metabolites (cotinine, nornicotine, norcotinine, and trans-3?-hydroxycotinine) in the plasma of HIV-1–positive and HIV-negative smokers. The multiple reaction monitoring transitions for nicotine, cotinine, trans-3?-hydroxycotinine, nornicotine, norcotinine, nicotine-d4, and cotinine-d3 were selected at mass-to-charge ratios of 163.3/117.1, 177.5/80.3, 193.2/80.1, 149.5/132.3, 163.4/80.3, 167.3/121.4, and 180.3/101.2, respectively. The lower limit of quantitation for nicotine and its metabolites was 0.53 ng/ml, which is relatively more sensitive than those previously reported. The concentration of nicotine was detected 5-fold lower in HIV-1–positive smokers (7.17 ± 3.8 ng/ml) than that observed in HIV-negative smokers (33.29 ± 15.4 ng/ml), whereas the concentration of the metabolite nornicotine was 3-fold higher in HIV-1–positive smokers (6.8 ± 2.9 ng/ml) than in HIV-negative smokers (2.3 ± 1.2 ng/ml). Although it was statistically nonsignificant, the concentration of the metabolite cotinine was also higher in HIV-1–positive smokers (85.6 ± 60.5 ng/ml) than in HIV-negative smokers (74.9 ± 40.5 ng/ml). In conclusion, a decrease in the concentration of nicotine and an increase in the concentration of its metabolites in HIV-1–positive smokers compared with HIV-negative smokers support the hypothesis that nicotine metabolism is enhanced in HIV-1–positive smokers compared with HIV-negative smokers. PMID:24301609

  3. Fueling of tandem mirror reactors

    SciTech Connect

    Gorker, G.E.; Logan, B.G.

    1985-01-01

    This paper summarizes the fueling requirements for experimental and demonstration tandem mirror reactors (TMRs), reviews the status of conventional pellet injectors, and identifies some candidate accelerators that may be needed for fueling tandem mirror reactors. Characteristics and limitations of three types of accelerators are described; neutral beam injectors, electromagnetic rail guns, and laser beam drivers. Based on these characteristics and limitations, a computer module was developed for the Tandem Mirror Reactor Systems Code (TMRSC) to select the pellet injector/accelerator combination which most nearly satisfies the fueling requirements for a given machine design.

  4. Ten tandem repeats of {beta}-hCG 109-118 enhance immunogenicity and anti-tumor effects of {beta}-hCG C-terminal peptide carried by mycobacterial heat-shock protein HSP65

    SciTech Connect

    Zhang Yankai [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Yan Rong [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); He Yi [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Liu Wentao [Nanjing Medical University, Nanjing 210029 (China); Cao Rongyue [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Yan Ming [National Drug Screening Laboratory, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Li Taiming [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Liu Jingjing [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China); Wu Jie [Minigene Pharmacy Laboratory, Biopharmaceutical College, China Pharmaceutical University, Tongjia Xiang 24, Nanjing 210009 (China)]. E-mail: wu_jie97@yahoo.com.cn

    2006-07-14

    The {beta}-subunit of human chorionic gonadotropin ({beta}-hCG) is secreted by many kinds of tumors and it has been used as an ideal target antigen to develop vaccines against tumors. In view of the low immunogenicity of this self-peptide,we designed a method based on isocaudamer technique to repeat tandemly the 10-residue sequence X of {beta}-hCG (109-118), then 10 tandemly repeated copies of the 10-residue sequence combined with {beta}-hCG C-terminal 37 peptides were fused to mycobacterial heat-shock protein 65 to construct a fusion protein HSP65-X10-{beta}hCGCTP37 as an immunogen. In this study, we examined the effect of the tandem repeats of this 10-residue sequence in eliciting an immune by comparing the immunogenicity and anti-tumor effects of the two immunogens, HSP65-X10-{beta}hCGCTP37 and HSP65-{beta}hCGCTP37 (without the 10 tandem repeats). Immunization of mice with the fusion protein HSP65-X10-{beta}hCGCTP37 elicited much higher levels of specific anti-{beta}-hCG antibodies and more effectively inhibited the growth of Lewis lung carcinoma (LLC) in vivo than with HSP65-{beta}hCGCTP37, which should suggest that HSP65-X10-{beta}hCGCTP37 may be an effective protein vaccine for the treatment of {beta}-hCG-dependent tumors and multiple tandem repeats of a certain epitope are an efficient method to overcome the low immunogenicity of self-peptide antigens.

  5. Microstability of the TMX tandem mirror experiments

    SciTech Connect

    Casper, T.A.; Berzins, L.V.

    1987-08-01

    In the tandem mirror device, an efficient source of warm ions, the central cell, is available for stabilization of ion loss-cone instabilities. These instabilities previously limited ion confinement in single-cell mirror experiments. In the simple tandem mirror device, TMX, the drift cyclotron loss-cone (DCLC) mode was stabilized by plasma flow from the central cell into the end cell. However, to enhance the central-cell confinement and provide MHD stability, neutral beams were injected perpendicular to the magnetic field, which resulted in the excitation in the end cell of the Alfven ion-cyclotron (AIC) instability driven by plasma pressure and velocity distribution anisotropy. In the thermal-barrier experiment, TMX-U, the end-cell beams were injected at a 45/sup 0/ angle to the magnetic field to produce a sloshing-ion distribution, which is required to form the thermal barrier and the plugging potential. Ion distributions created by oblique injection were stable to the AIC mode and to the midplane (minimum magnetic field location) DCLC mode. However, an ion loss-cone instability remained at an axial location just outside the outboard peak of the sloshing-ion axial density profile, which is the density peak closest to the end wall. This mode can enhance the sloshing-ion loss rate, particularly at the lower levels of electron-cyclotron resonance heating (ECRH) used to form the thermal barrier. The stability to ion-cyclotron modes is critical to the performance of tandem mirrors and to designs for a mirror-based, high-fluence neutron source.

  6. Tandem pump assembly

    SciTech Connect

    Dzioba, D.L.

    1986-05-06

    In combination, an engine having an oil pan containing oil at a certain level, a tandem pump arrangement is described mounted in the oil pan, the pump arrangement comprising an oil pump for delivering the oil under pressure to lubricate the engine and a vacuum pump for establishing a vacuum, the oil pump having two meshing gears of different pitch diameter adapted to produce oil pumping action by their meshing engagement upon drive to the one gear having the larger pitch diameter and the drive thereby of the other gear having the smaller pitch diameter at a higher speed, drive means for connecting the engine to drive the one gear. The vacuum pump has an input connected to be driven by the other gear whereby the vacuum pump is driven through the the oil pump at increased speed with an overdrive ratio determined by the ratio of the pitch diameters of the gears, the vacuum pump being lubricated by the oil in the oil pan and having an exhaust line exiting in the oil pan above the oil level so as to ensure return of such oil to the oil pan.

  7. Tandem Cylinder Noise Predictions

    NASA Technical Reports Server (NTRS)

    Lockhard, David P.; Khorrami, Mehdi R.; CHoudhari, Meelan M.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2007-01-01

    In an effort to better understand landing-gear noise sources, we have been examining a simplified configuration that still maintains some of the salient features of landing-gear flow fields. In particular, tandem cylinders have been studied because they model a variety of component level interactions. The present effort is directed at the case of two identical cylinders spatially separated in the streamwise direction by 3.7 diameters. Experimental measurements from the Basic Aerodynamic Research Tunnel (BART) and Quiet Flow Facility (QFF) at NASA Langley Research Center (LaRC) have provided steady surface pressures, detailed off-surface measurements of the flow field using Particle Image Velocimetry (PIV), hot-wire measurements in the wake of the rear cylinder, unsteady surface pressure data, and the radiated noise. The experiments were conducted at a Reynolds number of 166 105 based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent shedding process and simulate the effects of a high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The current calculations further explore the influence of the grid resolution and spanwise extent on the flow and associated radiated noise. Extensive comparisons with the experimental data are used to assess the ability of the computations to simulate the details of the flow. The results show that the pressure fluctuations on the upstream cylinder, caused by vortex shedding, are smaller than those generated on the downstream cylinder by wake interaction. Consequently, the downstream cylinder dominates the noise radiation, producing an overall directivity pattern that is similar to that of an isolated cylinder. Only calculations based on the full length of the model span were able to capture the complete decay in the spanwise correlation, thereby producing reasonable noise radiation levels.

  8. Tandem-structured, hot electron based photovoltaic cell with double Schottky barriers

    PubMed Central

    Lee, Young Keun; Lee, Hyosun; Park, Jeong Young

    2014-01-01

    We demonstrate a tandem-structured, hot electron based photovoltaic cell with double Schottky barriers. The tandem-structured, hot electron based photovoltaic cell is composed of two metal/semiconductor interfaces. Two types of tandem cells were fabricated using TiO2/Au/Si and TiO2/Au/TiO2, and photocurrent enhancement was detected. The double Schottky barriers lead to an additional pathway for harvesting hot electrons, which is enhanced through multiple reflections between the two barriers with different energy ranges. In addition, light absorption is improved by the band-to-band excitation of both semiconductors with different band gaps. Short-circuit current and energy conversion efficiency of the tandem-structured TiO2/Au/Si increased by 86% and 70%, respectively, compared with Au/Si metal/semiconductor nanodiodes, showing an overall solar energy conversion efficiency of 5.3%. PMID:24694838

  9. Micromorph silicon tandem solar cells with fully integrated 3D photonic crystal intermediate reflectors

    Microsoft Academic Search

    J. Üpping; A. Bielawny; S. Fahr; C. Rockstuhl; F. Lederer; L. Steidl; R. Zentel; T. Beckers; A. Lambertz; R. Carius; R. B. Wehrspohn

    2010-01-01

    A 3D photonic intermediate reflector for textured micromorph silicon tandem solar cells has been investigated. In thin-film silicon tandem solar cells consisting of amorphous and microcrystalline silicon with two junctions of a-Si\\/c-Si, efficiency enhancements can be achieved by increasing the current density in the a-Si top cell providing an optimized current matching at high current densities. For an ideal photon-management

  10. Modeling and Simulation of Tandem Tollbooth Operations with Max-Algebra Approach

    Microsoft Academic Search

    Young-Chae Hong; Dong-Kyu Kim; Seung-Young Kho; Soo Wook Kim; Hongsuk Yang

    2009-01-01

    This study proposes a new model to simulate tandem tollbooth system in order to enhance planning and management of toll plaza\\u000a facilities. A discrete-event stochastic microscopic simulation model is presented and developed to evaluate the operational\\u000a performance of tandem tollbooth. Traffic behavior is represented using a set of mathematical and logical algorithms. Modified\\u000a versions of Max-algebra approach are integrated into

  11. Hybrid tandem photovoltaic devices with a transparent conductive interconnecting recombination layer

    SciTech Connect

    Kim, Taehee; Choi, Jin Young; Jeon, Jun Hong; Kim, Youn-Su; Kim, Bong-Soo; Lee, Doh-Kwon; Kim, Honggon; Han, Seunghee [Solar Cell Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 136-791 (Korea, Republic of)] [Solar Cell Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 136-791 (Korea, Republic of); Kim, Kyungkon, E-mail: kimkk@ewha.ac.kr [Solar Cell Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 136-791 (Korea, Republic of) [Solar Cell Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul 136-791 (Korea, Republic of); Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750 (Korea, Republic of)

    2012-10-15

    Highlights: ? This work enhanced power conversion efficiency of the hybrid tandem solar cell from 1.0% to 2.6%. ? The interfacial series resistance of the tandem solar cell was eliminated by inserting ITO layer. ? This work shows the feasibility of the highly efficient hybrid tandem solar cells. -- Abstract: We demonstrate hybrid tandem photovoltaic devices with a transparent conductive interconnecting recombination layer. The series-connected hybrid tandem photovoltaic devices were developed by combining hydrogenated amorphous silicon (a-Si:H) and polymer-based organic photovoltaics (OPVs). In order to enhance the interfacial connection between the subcells, we employed highly transparent and conductive indium tin oxide (ITO) thin layer. By using the ITO interconnecting layer, the power conversion efficiency of the hybrid tandem solar cell was enhanced from 1.0% (V{sub OC} = 1.041 V, J{sub SC} = 2.97 mA/cm{sup 2}, FF = 32.3%) to 2.6% (V{sub OC} = 1.336 V, J{sub SC} = 4.65 mA/cm{sup 2}, FF = 41.98%) due to the eliminated interfacial series resistance.

  12. Tandem Mass Spectrometry in Physiology

    NSDL National Science Digital Library

    2007-12-01

    Tandem mass spectrometry coupled to liquid chromatography (LC-MS/MS) allows identification of proteins in a complex mixture without need for protein purification ("shotgun" proteomics). Recent progress in LC-MS/MS-based quantification, phosphoproteomic analysis, and targeted LC-MS/MS using multiple reaction monitoring (MRM) has made LC-MS/MS a powerful tool for the study of cell physiology.

  13. Tandem Filter Development for Thermophotovoltaic Energy Conversion from January 2003 to February 2006

    SciTech Connect

    Fourspring PM

    2007-03-19

    The intent of this report is to summarize the tandem filter development for spectral control of thermophotovoltaic energy conversion from January 2003 to the termination of the program in February 2006 and to closeout tandem filter development in order to capture the knowledge gained from the development effort. Over the last three years, the goals of the tandem filter development have been the following: (1) Study the limits of the design of the interference optical coatings component of a tandem filter in order to develop higher performance designs; (2) Enhance the fabrication process of the optical interference coatings to increase the fidelity with the intended design and allow more complex, higher performing designs; (3) Support TPV module testing by providing tandem filters and assembly assistance; (4) Identify and develop materials for optical interference coatings that are stable at higher temperatures than current materials; and (5) Improve the understanding of the directional and spectral reflectance and transmittance characterization of the completed tandem filters to insure the veracity of the characterization data and to provide useful feedback to the tandem filter development process. This development effort has been a collaboration between KAPL and its contracted development partner, Rugate Technologies Inc.

  14. Tandem electrostatic accelerators for BNCT

    SciTech Connect

    Ma, J.C. [Yanch and W.B. Howard Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1994-12-31

    The development of boron neutron capture therapy (BNCT) into a viable therapeutic modality will depend, in part, on the availability of suitable neutron sources compatible with installation in a hospital environment. Low-energy accelerator-based intense neutron sources, using electrostatic or radio frequency quadrupole proton accelerators have been suggested for this purpose and are underdevelopment at several laboratories. New advances in tandem electrostatic accelerator technology now allow acceleration of the multi-milliampere proton beams required to produce therapeutic neutron fluxes for BNCT. The relatively compact size, low weight and high power efficiency of these machines make them particularly attractive for installation in a clinical or research facility. The authors will describe the limitations on ion beam current and available neutron flux from tandem accelerators relative to the requirements for BNCT research and therapy. Preliminary designs and shielding requirements for a tandern accelerator-based BNCT research facility will also be presented.

  15. "Nanocrystal bilayer for tandem catalysis"

    SciTech Connect

    Yamada, Yusuke; Tsung, Chia Kuang; Huang, Wenyu; Huo, Ziyang; E.Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Samorjai, Gabor A; Yang, Peidong

    2011-01-24

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts

  16. Nanocrystal bilayer for tandem catalysis.

    PubMed

    Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu; Huo, Ziyang; Habas, Susan E; Soejima, Tetsuro; Aliaga, Cesar E; Somorjai, Gabor A; Yang, Peidong

    2011-05-01

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO(2)-Pt and Pt-SiO(2), can be used to catalyse two distinct sequential reactions. The CeO(2)-Pt interface catalysed methanol decomposition to produce CO and H(2), which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO(2) interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts. PMID:21505495

  17. Nanocrystal bilayer for tandem catalysis

    NASA Astrophysics Data System (ADS)

    Yamada, Yusuke; Tsung, Chia-Kuang; Huang, Wenyu; Huo, Ziyang; Habas, Susan E.; Soejima, Tetsuro; Aliaga, Cesar E.; Somorjai, Gabor A.; Yang, Peidong

    2011-05-01

    Supported catalysts are widely used in industry and can be optimized by tuning the composition and interface of the metal nanoparticles and oxide supports. Rational design of metal-metal oxide interfaces in nanostructured catalysts is critical to achieve better reaction activities and selectivities. We introduce here a new class of nanocrystal tandem catalysts that have multiple metal-metal oxide interfaces for the catalysis of sequential reactions. We utilized a nanocrystal bilayer structure formed by assembling platinum and cerium oxide nanocube monolayers of less than 10 nm on a silica substrate. The two distinct metal-metal oxide interfaces, CeO2-Pt and Pt-SiO2, can be used to catalyse two distinct sequential reactions. The CeO2-Pt interface catalysed methanol decomposition to produce CO and H2, which were subsequently used for ethylene hydroformylation catalysed by the nearby Pt-SiO2 interface. Consequently, propanal was produced selectively from methanol and ethylene on the nanocrystal bilayer tandem catalyst. This new concept of nanocrystal tandem catalysis represents a powerful approach towards designing high-performance, multifunctional nanostructured catalysts.

  18. Superior radiation-resistant properties of InGaP\\/GaAs tandem solar cells

    Microsoft Academic Search

    Masafumi Yamaguchi; Takeshi Okuda; Stephen J. Taylor; Tatsuya Takamoto; Eiji Ikeda; Hiroshi Kurita

    1997-01-01

    The observation of minority-carrier injection-enhanced annealing of radiation damage to InGa0.5P0.5\\/GaAs tandem solar cells is reported. Radiation resistance of InGaP\\/GaAs tandem solar cells as is similar with GaAs-on-Ge cells have been confirmed with 1 MeV electron irradiations. Moreover, minority-carrier injection under light illumination and forward bias conditions is shown to enhance defect annealing in InGaP and to result in the

  19. Short Tandem Repeat DNA Internet Database

    National Institute of Standards and Technology Data Gateway

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  20. 47 CFR 69.129 - Signalling for tandem switching.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Signalling for tandem switching. 69.129 Section 69...Charges § 69.129 Signalling for tandem switching. A charge that is expressed...company for provision of signalling for tandem switching. [59 FR 32930, June...

  1. The construction of tandem dye-sensitized solar cells from chemically-derived nanoporous photoelectrodes

    NASA Astrophysics Data System (ADS)

    Choi, Hongsik; Hwang, Taehyun; Lee, Sangheon; Nam, Seunghoon; Kang, Joonhyeon; Lee, Byungho; Park, Byungwoo

    2015-01-01

    A tandem dye-sensitized solar cell (tandem-DSSC) was synthesized on the basis of thin-film semiconductor electrodes. The nanoporous p-type NiO films were successfully obtained by simultaneous deposition of Al and Ni, followed by selective etching of Al and oxidation. Likewise, the n-type photoanode was made where Ag was etched in nitric acid after the initial formation of Ag/TiO2 nanocomposites. Such dye-sensitized photoelectrodes were combined to construct a tandem solar cell which exhibited an enhanced open-circuit voltage. Also, the tandem devices were subjected to various light fluxes to correlate the experimental cell parameters (open-circuit voltage, short-circuit current, fill factor, recombination shunt resistance, etc.) with the ideal one-diode model. Interestingly, impedance spectra of the tandem cell was well matched with the parameters from each of the n-type or p-type DSSC, indicative of successfully-designed tandem structure.

  2. Superior radiation-resistant properties of InGaP/GaAs tandem solar cells

    SciTech Connect

    Yamaguchi, M.; Okuda, T.; Taylor, S.J.; Takamoto, T. [Toyota Technological Institute 2-12-1 Hisakata, Tempaku, Nagoya 468 (Japan)] [Toyota Technological Institute 2-12-1 Hisakata, Tempaku, Nagoya 468 (Japan); Ikeda, E.; Kurita, H. [Central Resource Laboratory, Japan Energy Company, Niizo-Minami, Toda, Saitama 335 (Japan)] [Central Resource Laboratory, Japan Energy Company, Niizo-Minami, Toda, Saitama 335 (Japan)

    1997-03-01

    The observation of minority-carrier injection-enhanced annealing of radiation damage to InGa{sub 0.5}P{sub 0.5}/GaAs tandem solar cells is reported. Radiation resistance of InGaP/GaAs tandem solar cells as is similar with GaAs-on-Ge cells have been confirmed with 1 MeV electron irradiations. Moreover, minority-carrier injection under light illumination and forward bias conditions is shown to enhance defect annealing in InGaP and to result in the recovery of InGaP/GaAs tandem solar cell properties. These results suggest that the InGaP/GaAs(/Ge) multijunction solar cells and InGaP-based devices have great potential for space applications. {copyright} {ital 1997 American Institute of Physics.}

  3. Improved monolithic tandem solar cell

    SciTech Connect

    Wanlass, M.W.

    1991-04-23

    A single-crystal, monolithic, tandem, photovoltaic solar cell is described which includes (a) an InP substrate having upper and lower surfaces, (b) a first photoactive subcell on the upper surf ace of the InP substrate, (c) a second photoactive subcell on the first subcell; and (d) an optically transparent prismatic cover layer over the second subcell. The first photoactive subcell is GaInAsP of defined composition. The second subcell is InP. The two subcells are lattice matched.

  4. Argonne Tandem-Linac Accelerator System

    NASA Astrophysics Data System (ADS)

    Bollinger, L. M.

    1983-03-01

    Design considerations and operational experience for the existing heavy-ion accelerator consisting of a tandem injecting into a superconducting linac are summarized, with emphasis on the general features of the system. This introduction provides the basis for a discussion of the objectives and design of ATLAS, a larger tandem-linac system being formed by expanding the existing superconducting linac.

  5. 33 CFR 401.41 - Tandem lockage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Navigable Waters 3 2010-07-01 2010-07-01 false Tandem lockage. 401.41 Section 401.41 Navigation and Navigable...REGULATIONS AND RULES Regulations Seaway Navigation § 401.41 Tandem lockage. Where two or more vessels are being locked...

  6. Software dependability in the Tandem GUARDIAN system

    NASA Technical Reports Server (NTRS)

    Lee, Inhwan; Iyer, Ravishankar K.

    1995-01-01

    Based on extensive field failure data for Tandem's GUARDIAN operating system this paper discusses evaluation of the dependability of operational software. Software faults considered are major defects that result in processor failures and invoke backup processes to take over. The paper categorizes the underlying causes of software failures and evaluates the effectiveness of the process pair technique in tolerating software faults. A model to describe the impact of software faults on the reliability of an overall system is proposed. The model is used to evaluate the significance of key factors that determine software dependability and to identify areas for improvement. An analysis of the data shows that about 77% of processor failures that are initially considered due to software are confirmed as software problems. The analysis shows that the use of process pairs to provide checkpointing and restart (originally intended for tolerating hardware faults) allows the system to tolerate about 75% of reported software faults that result in processor failures. The loose coupling between processors, which results in the backup execution (the processor state and the sequence of events) being different from the original execution, is a major reason for the measured software fault tolerance. Over two-thirds (72%) of measured software failures are recurrences of previously reported faults. Modeling, based on the data, shows that, in addition to reducing the number of software faults, software dependability can be enhanced by reducing the recurrence rate.

  7. The thermodynamic limits of tandem photovoltaic devices with intermediate band

    NASA Astrophysics Data System (ADS)

    Lee, Jongwon; Honsberg, Christiana B.

    2012-02-01

    We present a hybrid thermodynamic model for multijunction solar cells with intermediate bands that demonstrates possible improvements to conventional multijunction photovoltaic systems. Applying this model to selected tandem cell structures shows that the performance of such hybrid solar cells is enhanced and that multiple transitions from intermediate bands can reduce the number of material stacks and boost overall efficiency. We demonstrate the results of detailed simulations for multiple numbers of stacks of hybrid multijunction solar cells. And, we can choose proper materials to compose intermediate band for each junction. Furthermore, we suggest other alternative hybrid solar cell systems to absorb moderate photon energy range and find appropriate materials for hybrid solar cells.

  8. Tandem Mirror Reactor Systems Code (Version I)

    SciTech Connect

    Reid, R.L.; Finn, P.A.; Gohar, M.Y.; Barrett, R.J.; Gorker, G.E.; Spampinaton, P.T.; Bulmer, R.H.; Dorn, D.W.; Perkins, L.J.; Ghose, S.

    1985-09-01

    A computer code was developed to model a Tandem Mirror Reactor. Ths is the first Tandem Mirror Reactor model to couple, in detail, the highly linked physics, magnetics, and neutronic analysis into a single code. This report describes the code architecture, provides a summary description of the modules comprising the code, and includes an example execution of the Tandem Mirror Reactor Systems Code. Results from this code for two sensitivity studies are also included. These studies are: (1) to determine the impact of center cell plasma radius, length, and ion temperature on reactor cost and performance at constant fusion power; and (2) to determine the impact of reactor power level on cost.

  9. A decoupled observer for tandem systems

    E-print Network

    Earhart, Robert Jenkins

    1971-01-01

    A DECOUPLED OBSERVER FOR TANDEM SYSTEMS A Thesis by Robert Jenkins Earhart Submitted to the Graduate College of Texas AGM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1971 Major Subject...: Electrical Engineering A DECOUPLED OBSERVER FOR TANDEM SYSTEMS A Thesis by Robert Jenkins Earhart Approved as to style and content by: ( airman of Comms tee) He of D tment) Member) Member) Member) (Member) Member August 1971 ABSTRACT A Decoupled...

  10. Microstability of the TMX tandem mirror experiments

    Microsoft Academic Search

    T. A. Casper; L. V. Berzins

    1987-01-01

    In the tandem mirror device, an efficient source of warm ions, the central cell, is available for stabilization of ion loss-cone instabilities. These instabilities previously limited ion confinement in single-cell mirror experiments. In the simple tandem mirror device, TMX, the drift cyclotron loss-cone (DCLC) mode was stabilized by plasma flow from the central cell into the end cell. However, to

  11. Lack of p53 Decreases Basal Oxidative Stress Levels in the Brain Through Upregulation of Thioredoxin-1, Biliverdin Reductase-A, Manganese Superoxide Dismutase, and Nuclear Factor Kappa-B

    PubMed Central

    Barone, Eugenio; Cenini, Giovanna; Sultana, Rukhsana; Di Domenico, Fabio; Fiorini, Ada; Perluigi, Marzia; Noel, Teresa; Wang, Chi; Mancuso, Cesare; St. Clair, Daret K.

    2012-01-01

    Abstract Aims: The basal oxidative and nitrosative stress levels measured in cytosol, mitochondria, and nuclei as well as in the whole homogenate obtained from the brain of wild type (wt) and p53 knockout [p53(?/?)] mice were evaluated. We hypothesized that the loss of p53 could trigger the activation of several protective mechanisms such as those involving thioredoxin-1 (Thio-1), the heme-oxygenase-1/biliverdin reductase-A (HO-1/BVR-A) system, manganese superoxide dismutase (MnSOD), the IkB kinase type ? (IKK?)/nuclear factor kappa-B (NF-kB), and the nuclear factor-erythroid 2 (NF-E2) related factor 2 (Nrf-2). Results: A decrease of protein carbonyls, protein-bound 4-hydroxy-2-nonenal (HNE), and 3-nitrotyrosine (3-NT) was observed in the brain from p53(?/?) mice compared with wt. Furthermore, we observed a significant increase of the expression levels of Thio-1, BVR-A, MnSOD, IKK?, and NF-kB. Conversely a significant decrease of Nrf-2 protein levels was observed in the nuclear fraction isolated from p53(?/?) mice. No changes were found for HO-1. Innovation: This is the first study of basal oxidative/nitrosative stress in in vivo conditions of brain obtained from p53(?/?) mice. New insights into the role of p53 in oxidative stress have been gained. Conclusion: We demonstrated, for the first time, that the lack of p53 reduces basal oxidative stress levels in mice brain. Due to the pivotal role that p53 plays during cellular stress response our results provide new insights into novel therapeutic strategies to modulate protein oxidation and lipid peroxidation having p53 as a target. The implications of this work are profound, particularly for neurodegenerative disorders. Antioxid. Redox Signal. 16, 1407–1420. PMID:22229939

  12. A mechanistic insight into a proteasome-independent constitutive inhibitor kappaBalpha (IkappaBalpha) degradation and nuclear factor kappaB (NF-kappaB) activation pathway in WEHI-231 B-cells.

    PubMed Central

    Shumway, Stuart D; Miyamoto, Shigeki

    2004-01-01

    Inducible activation of the transcription factor NF-kappaB (nuclear factor kappaB) is classically mediated by proteasomal degradation of its associated inhibitors, IkappaBalpha (inhibitory kappaBalpha) and IkappaBbeta. However, certain B-lymphocytes maintain constitutively nuclear NF-kappaB activity (a p50-c-Rel heterodimer) which is resistant to inhibition by proteasome inhibitors. This activity in the WEHI-231 B-cell line is associated with continual and preferential degradation of IkappaBalpha, which is also unaffected by proteasome inhibitors. Pharmacological studies indicated that there was a correlation between inhibition of IkappaBalpha degradation and constitutive p50-c-Rel activity. Domain analysis of IkappaBalpha by deletion mutagenesis demonstrated that an N-terminal 36-amino-acid sequence of IkappaBalpha represented an instability determinant for constitutive degradation. Moreover, domain grafting studies indicated that this sequence was sufficient to cause IkappaBbeta, but not chloramphenicol acetyltransferase, to be rapidly degraded in WEHI-231 B-cells. However, this sequence was insufficient to target IkappaBbeta to the non-proteasome degradation pathway, suggesting that there was an additional cis-element(s) in IkappaBalpha that was required for complete targeting. Nevertheless, the NF-kappaB pool associated with IkappaBbeta now became constitutively active by virtue of IkappaBbeta instability in these cells. These findings further support the notion that IkappaB instability governs the maintenance of constitutive p50-c-Rel activity in certain B-cells via a unique degradation pathway. PMID:14763901

  13. Antiosteoclastogenesis activity of a CO2 laser antagonizing receptor activator for nuclear factor kappaB ligand-induced osteoclast differentiation of murine macrophages

    NASA Astrophysics Data System (ADS)

    Kuo, Chun-Liang; Kao, Chia-Tze; Fang, Hsin-Yuan; Huang, Tsui-Hsien; Chen, Yi-Wen; Shie, Ming-You

    2015-03-01

    Macrophage cells are the important effector cells in the immune reaction which are indispensable for osteoclastogenesis; their heterogeneity and plasticity renders macrophages a primer target for immune system modulation. In recent years, there have been very few studies about the effects of macrophage cells on laser treatment-regulated osteoclastogenesis. In this study, RAW 264.7 macrophage cells were treated with RANKL to regulate osteoclastogenesis. We used a CO2 laser as a model biostimulation to investigate the role of osteoclastogenic. We also evaluated cell viability, cell death and cathepsin K expression. The CO2 laser inhibited a receptor activator of the NF-?B ligand (RANKL)-induced formation of osteoclasts during the osteoclast differentiation process. It was also found that irradiation for two times reduced RANKL-enhanced TRAP activity in a dose-dependent manner. Furthermore, CO2 laser-treatment diminished the expression and secretion of cathepsin K elevated by RANKL and was concurrent with the inhibition of TRAF6 induction and NF-?B activation. The current report demonstrates that CO2 laser abrogated RANKL-induced osteoclastogenesis by retarding osteoclast differentiation. The CO2 laser can modulate every cell through dose-dependent in vitro RANKL-mediated osteoclastogenesis, such as the proliferation and fusion of preosteoclasts and the maturation of osteoclasts. Therefore, the current results serve as an improved explanation of the cellular roles of macrophage cell populations in osteoclastogenesis as well as in alveolar bone remodeling by CO2 laser-treatment.

  14. Development of a rapid capture-cum-detection method for Escherichia coli O157 from apple juice comprising nano-immunomagnetic separation in tandem with surface enhanced Raman scattering.

    PubMed

    Najafi, Roya; Mukherjee, Shubhasish; Hudson, Jim; Sharma, Anup; Banerjee, Pratik

    2014-10-17

    A combined capture and detection method comprising of nano-immunomagnetic separation (NIMS) and surface enhanced Raman spectroscopy (SERS) was developed to detect Escherichia coli O157 from liquid media including apple juice. The capture antibodies (cAbs) were immobilized on magnetite-gold (Fe3O4/Au) magnetic nanoparticles (MNPs) which were used for separation and concentration of the E. coli O157 cells from model liquid food matrix. The capture efficiency (CE) for E. coli O157 using MNP was found to be approximately 84-94%. No cross reactivity was observed with background non-target organisms. There was a significant difference in the mean CE of bacteria captured by MNP and commercially sourced immunomagnetic microbeads (p<0.05). For the detection of target pathogen, SERS labels were prepared by conjugating gold nanoparticles with Raman reporter molecules and the detector antibody (dAb). Au-Raman label-dAb was interacted with gold coated MNP-cAb-E. coli O157 complex. The ability of this immunoassay to detect E. coli O157 in apple juice was investigated. We have successfully applied the synthesized Fe3O4/Au nanoclusters to E. coli O157 detection in apple juice using the SERS method. The lowest detectable bacterial cell concentration in apple juice was 10(2)CFU/mL with a total analysis time of less than an hour. This method presents a convenient way of preconcentration, separation, and detection of low levels of target pathogen from liquid food matrix. PMID:25133877

  15. Ant search strategies after interrupted tandem runs.

    PubMed

    Franks, Nigel R; Richardson, Thomas O; Keir, Samantha; Inge, Stephen J; Bartumeus, Frederic; Sendova-Franks, Ana B

    2010-05-01

    Tandem runs are a form of recruitment in ants. During a tandem run, a single leader teaches one follower the route to important resources such as sources of food or better nest sites. In the present study, we investigate what tandem leaders and followers do, in the context of nest emigration, if their partner goes missing. Our experiments involved removing either leaders or followers at set points during tandem runs. Former leaders first stand still and wait for their missing follower but then most often proceed alone to the new nest site. By contrast, former followers often first engage in a Brownian search, for almost exactly the time that their former leader should have waited for them, and then former followers switch to a superdiffusive search. In this way, former followers first search their immediate neighbourhood for their lost leader before becoming ever more wide ranging so that in the absence of their former leader they can often find the new nest, re-encounter the old one or meet a new leader. We also show that followers gain useful information even from incomplete tandem runs. These observations point to the important principle that sophisticated communication behaviours may have evolved as anytime algorithms, i.e. procedures that are beneficial even if they do not run to completion. PMID:20435821

  16. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...part. (3) The tandem parachute system contains an operational automatic...manufacturer of that tandem parachute system. The device must— (i) Have...is equipped with a single-point release system. (6) The reserve...

  17. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...part. (3) The tandem parachute system contains an operational automatic...manufacturer of that tandem parachute system. The device must— (i) Have...is equipped with a single-point release system. (6) The reserve...

  18. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...part. (3) The tandem parachute system contains an operational automatic...manufacturer of that tandem parachute system. The device must— (i) Have...is equipped with a single-point release system. (6) The reserve...

  19. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...part. (3) The tandem parachute system contains an operational automatic...manufacturer of that tandem parachute system. The device must— (i) Have...is equipped with a single-point release system. (6) The reserve...

  20. heritability. The overdue promise of short tandem repeat variation for

    E-print Network

    Queitsch, Christine

    heritability. The overdue promise of short tandem repeat variation for Maximilian Press, Keisha D variation for heritability.1 2 Maximilian O. Press, Keisha D. Carlson, Christine Queitsch3 Keywords: short tandem repeats, microsatellites, heritability, epistasis,9 sequencing technologies.10

  1. Tandem mass spectrometry in the clinical chemistry laboratory

    Microsoft Academic Search

    Kent C. Dooley

    2003-01-01

    Tandem mass spectrometry is becoming an increasingly important analytical technology in the clinical laboratory environment. Applications in toxicology and therapeutic drug monitoring have opened the door for tandem mass spectrometry and now we are seeing a vast array of new applications being developed. It has been the combination of tandem mass spectrometry with sample introduction techniques employing atomospheric pressure ionization

  2. Tandem repeats finder: a program to analyze DNA sequences

    Microsoft Academic Search

    Gary Benson

    1999-01-01

    A tandem repeat in DNA is two or more contiguous, approximate copies of a pattern of nucleotides. Tandem repeats have been shown to cause human disease, may play a variety of regulatory and evolutionary roles and are important laboratory and analytic tools. Extensive knowledge about pattern size, copy number, mutational history, etc. for tandem repeats has been limited by the

  3. Techniques for detecting approximate tandem repeats in DNA

    Microsoft Academic Search

    Thao T. Tran; Vincent A. Emanuele; G. Tong Zhou II

    2004-01-01

    The detection of tandem repeats is important in biology and medicine as it can be used for phylogenetic studies and disease diagnosis. The paper proposes two techniques for detecting approximate tandem repeats (ATRs) in DNA sequences. First, an evolutionary force heuristic is proposed to merge interspersed perfect tandem repeat sequences into an ATR structure. Next., a more general method is

  4. 14 CFR 105.45 - Use of tandem parachute systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Use of tandem parachute systems. 105.45 Section...Equipment and Packing § 105.45 Use of tandem parachute systems. (a) No person may conduct a parachute operation using a tandem parachute system, and no pilot in...

  5. Technology for large tandem mirror experiments

    SciTech Connect

    Thomassen, K.I.

    1980-09-04

    Construction of a large tandem mirror (MFTF-B) will soon begin at Lawrence Livermore National Laboratory (LLNL). Designed to reach break-even plasma conditions, the facility will significantly advance the physics and technology of magnetic-mirror-based fusion reactors. This paper describes the objectives and the design of the facility.

  6. Short tandem repeat polymorphism evolution in humans

    Microsoft Academic Search

    F Calafell; A Shuster; WC Speed; JR Kidd; KK Kidd

    1998-01-01

    Forty-five dinucleotide short tandem repeat polymorphisms were typed in ten large samples of a globally distributed set of populations. Although these markers had been selected for high heterozygosity in European populations, we found them to be sufficiently informative for linkage analysis in non-Europeans. Heterozygosity, mean number of alleles, and mean number of private alleles followed a common trend: they were

  7. Swept Inducer Blades With Tandem Radial Slots

    NASA Technical Reports Server (NTRS)

    Meng, Sen Y.

    1995-01-01

    Slanted radial slots at tandem positions along approximate streamlines incorporated into swept inducer blades in turbopump, according to proposal. With suitable design, slots suppress low-frequency oscillations induced by cavitation, without causing excessive loss of inducer head. Slots cut into solid blades by wire electrical-discharge machining.

  8. MASPIC: intensity-based tandem mass spectrometry scoring scheme that improves peptide identification at high confidence.

    PubMed

    Narasimhan, Chandrasegaran; Tabb, David L; Verberkmoes, Nathan C; Thompson, Melissa R; Hettich, Robert L; Uberbacher, Edward C

    2005-12-01

    Algorithmic search engines bridge the gap between large tandem mass spectrometry data sets and the identification of proteins associated with biological samples. Improvements in these tools can greatly enhance biological discovery. We present a new scoring scheme for comparing tandem mass spectra with a protein sequence database. The MASPIC (Multinomial Algorithm for Spectral Profile-based Intensity Comparison) scorer converts an experimental tandem mass spectrum into a m/z profile of probability and then scores peak lists from potential candidate peptides using a multinomial distribution model. The MASPIC scoring scheme incorporates intensity, spectral peak density variations, and m/z error distribution associated with peak matches into a multinomial distribution. The scoring scheme was validated on two standard protein mixtures and an additional set of spectra collected on a complex ribosomal protein mixture from Rhodopseudomonas palustris. The results indicate a 5-15% improvement over Sequest for high-confidence identifications. The performance gap grows as sequence database size increases. Additional tests on spectra from proteinase-K digest data showed similar performance improvements demonstrating the advantages in using MASPIC for studying proteins digested with less specific proteases. All these investigations show MASPIC to be a versatile and reliable system for peptide tandem mass spectral identification. PMID:16316165

  9. Tandem microwave waste remediation and decontamination system

    SciTech Connect

    Wicks, G.G.; Clark, D.E.; Schulz, R.L.

    1999-10-19

    The invention discloses a tandem microwave system consisting of a primary chamber in which microwave energy is used for the controlled combustion of materials. A second chamber is used to further treat the off-gases from the primary chamber by passage through a susceptor matrix subjected to additional microwave energy. The direct microwave radiation and elevated temperatures provide for significant reductions in the qualitative and quantitative emissions of the treated off gases. The tandem microwave system can be utilized for disinfecting wastes, sterilizing materials, and/or modifying the form of wastes to solidify organic or inorganic materials. The simple design allows on-site treatment of waste by small volume waste generators.

  10. The metal interlayer in the charge generation layer of tandem organic light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Lee, Yu-Hao; Lin, Ming-Wei; Wen, Ten-Chin; Guo, Tzung-Fang

    2013-10-01

    This work studies the interface in the charge generation layer (CGL), consisting of aluminum (Al) doped in poly(ethylene glycol) dimethyl ether as an n-type layer and 2, 3, 5, 6-tetrafluoro-7, 7, 8, 8-tetracyanoquinodimethane (F4-TCNQ) doped in N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine as an p-type layer, in tandem organic light-emitting diodes (OLEDs). Introducing a thin high work function metal interlayer (e.g., Ag or Au) effectively improves the transport and inhibits the accumulation of charges in the CGL, which markedly reduces the operating voltage and enhances the efficiency of tandem OLEDs. We attribute that the high density of surface states on metal clusters (interlayer) reduce the junction barrier to facilitate the transport of carriers through CGL. Experimental results show enhancements of tandem OLEDs by an additional metal interlayer as follows: luminous efficiency increases from 37.2 to 51.4 cd A-1, the light turn-on voltage decreases from 9.2 to 6.6 V, and luminescence at 10 mA cm-2 increases from 3712 to 5211 cd m-2.

  11. Tandem mirror next step: remote maintenance

    SciTech Connect

    Doggett, J.N.; Damm, C.C.; Hanson, C.L.

    1980-10-27

    This study of the next proposed experiment in the Mirror Fusion Program, the Tandem Mirror Next Step (TMNS), has included serious consideration of the maintenance requirements of such a large source of high energy neutrons with its attendant throughput of tritium. Although maintenance will be costly in time and money, our conclusion is that with careful attention to a design for maintenance plan such a device can be reliably operated.

  12. Current and lattice matched tandem solar cell

    DOEpatents

    Olson, Jerry M. (Lakewood, CO)

    1987-01-01

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga.sub.x In.sub.1-x P (0.505.ltoreq.X.ltoreq.0.515) top cell semiconductor lattice matched to a GaAs bottom cell semiconductor at a low-resistance heterojunction, preferably a p+/n+ heterojunction between the cells. The top and bottom cells are both lattice matched and current matched for high efficiency solar radiation conversion to electrical energy.

  13. Short Tandem Repeat DNA Internet Database

    NSDL National Science Digital Library

    This website contains comprehensive information relating to forensic DNA analysis. It has material from an introductory to an advanced level on forensic DNA technology. The material provides general information on DNA markers that are of interest to human identification. The site contains both introductory and in-depth discussions of short tandem repeats (STRs) and other DNA markers currently used by the forensic community. Powerpoint and PDF presentations on STR training material are available and can be readily downloaded.

  14. Small, octopole-stabilized tandem mirror reactor

    Microsoft Academic Search

    R. S. Devoto; D. E. Baldwin; B. G. Logan; G. W. Hamilton; B. W. Johnston

    1984-01-01

    It is shown that the use of octopole stabilization in a tandem mirror allows a large reduction in end-cell length. A novel feature of the method proposed is the placement of the minimum IBI region considerably off axis, thus rendering the core plasma more axisymmetric. The region from the core to the field minimum is bridged by a mirror-confined, hot-electron

  15. Strain Balanced Quantum Well Monolithic Tandem Solar Cells

    Microsoft Academic Search

    A. Ioannides; T. N. D. Tibbits; J. P. Connolly; D. B. Bushnell; K. W. J. Barnham; C. Calder; G. Hill; J. S. Roberts; G. Smekens

    2006-01-01

    The effect of incorporating strain balanced multi-quantum well structures in InGaP\\/GaAs monolithic tandem solar cells is investigated. At present the majority of InGaP\\/GaAs tandem cells are current limited by the bottom GaAs junction. Incorporation of multi-quantum well structures in the GaAs bottom junction extends the cell absorption to longer wavelengths. This allows current matched dual junction tandem cells to achieve

  16. 47 CFR 36.124 - Tandem switching equipment-Category 2.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... false Tandem switching equipment-Category 2. 36.124 Section 36.124 Telecommunication...124 Tandem switching equipment—Category 2. (a) Tandem switching...included with Local Switching Equipment—Category 3. (1) At toll center...

  17. 47 CFR 36.124 - Tandem switching equipment-Category 2.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... false Tandem switching equipment-Category 2. 36.124 Section 36.124 Telecommunication...124 Tandem switching equipment—Category 2. (a) Tandem switching...included with Local Switching Equipment—Category 3. (1) At toll center...

  18. 47 CFR 69.713 - Common line, traffic-sensitive, and tandem-switched transport services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...traffic-sensitive, and tandem-switched transport services. 69.713 Section 69...traffic-sensitive, and tandem-switched transport services. (a) Scope. This paragraph...traffic-sensitive components of tandem-switched transport services, as described in §§...

  19. 47 CFR 69.713 - Common line, traffic-sensitive, and tandem-switched transport services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...Common line, traffic-sensitive, and tandem-switched transport services. 69...Common line, traffic-sensitive, and tandem-switched transport services. (a...The traffic-sensitive components of tandem-switched transport services, as...

  20. A Hybrid Approach To Tandem Cylinder Noise

    NASA Technical Reports Server (NTRS)

    Lockard, David P.

    2004-01-01

    Aeolian tone generation from tandem cylinders is predicted using a hybrid approach. A standard computational fluid dynamics (CFD) code is used to compute the unsteady flow around the cylinders, and the acoustics are calculated using the acoustic analogy. The CFD code is nominally second order in space and time and includes several turbulence models, but the SST k - omega model is used for most of the calculations. Significant variation is observed between laminar and turbulent cases, and with changes in the turbulence model. A two-dimensional implementation of the Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise.

  1. Tandem constructs: preventing the rise of superweeds.

    PubMed

    Gressel, J

    1999-09-01

    Transgenic crops may interbreed with nearby weeds, increasing their competitiveness, and may themselves become a 'volunteer' weed in the following crop. The desired transgene can be coupled in tandem with genes that would render hybrid offspring or volunteer weeds less able to compete with crops, weeds and wild species. Genes that prevent seed shatter or secondary dormancy, or that dwarf the recipient could all be useful for mitigation and may have value to the crop. Many such genes have been isolated in the past few years. PMID:10461182

  2. The capacity of digital links in tandem

    NASA Technical Reports Server (NTRS)

    Posner, E. C.; Rubin, A. L.

    1984-01-01

    The present investigation is concerned with the error control strategy used in connection with digital data networks, taking into account the capacity of the end-to-end channel. It is assumed that the only source of noise is Gaussian and that bandwidth limitation on capacity can be ignored. Attention is given to L links in tandem with binary repeaters, the asymptotic capacity with a large number of links, some alternative repeater strategies, and approaches for lowering the bit error probability. Numerical results are presented, taking into consideration capacity versus link error probability for various numbers of links.

  3. Potential of optical design in tandem micromorph silicon solar cells

    NASA Astrophysics Data System (ADS)

    Krc, J.; Campa, A.; Smole, F.; Topic, M.

    2006-04-01

    The potential of three advanced optical designs in tandem micromorph silicon solar cells are analysed by means of optical simulations: enhanced light scattering, intermediate reflector (interlayer) and antireflective coating (ARC) on glass. The effects on quantum efficiency, QE, and short circuit current density, J SC, of the top and bottom cell are investigated. In case of enhanced light scattering, the role of haze parameter and angular distribution function of scattered light is analysed separately. High haze parameter improves light trapping in top and bottom cell. However, the improvement in QE and J SC of the bottom cell is limited at higher haze parameters due to increased absorption in top cell and increased optical losses in realistic textured ZnO/Ag back contact. Broad ADF plays an important role for improving the performances of both, top and bottom cell. The role of refractive index of an interlayer between top and bottom cell is analysed. Significant increases in QE and J SC of the top cell are revealed for small refractive indexes of the interlayer (n < 2.0). At the same time noticeable decrease in the performance of the bottom cell is observed. Optimisation of thickness and refractive index of a single-layer ARC on glass is carried out in order to obtain maximal J SC either in top or in bottom cell. Moderate increases in J SC and QE are obtained for optimised ARC parameters. Among the three optical designs, the greatest potential, considering the improvements in both cells, is revealed for enhanced light scattering.

  4. TassDB: a database of alternative tandem splice sites

    Microsoft Academic Search

    Michael Hiller; Swetlana Nikolajewa; Klaus Huse; Karol Szafranski; Philip Rosenstiel; Stefan Schuster; Rolf Backofen; Matthias Platzer

    2007-01-01

    Subtle alternative splice events at tandem splice sites are frequent in eukaryotes and substantially increase the complexity of transcriptomes and proteomes. We have developed a relational data- base, TassDB (TAndem Splice Site DataBase), which stores extensive data about alternative splice events at GYNGYN donors and NAGNAG acceptors. These splice events are of subtle nature since they mostly result in the

  5. Speckle-phase measurement in a tandem-vortex coronagraph.

    PubMed

    Serabyn, Eugene; Wallace, J Kent; Mawet, Dimitri

    2011-10-01

    A tandem-vortex coronagraph can in theory enable high-contrast imaging behind a classical on-axis telescope. Here we point out that a tandem-vortex coronagraph configuration can also directly enable the measurement of the phases of focal-plane speckles, thereby allowing for their suppression in the resultant high-contrast image. PMID:22016212

  6. Monitoring Bilingualism: Pedagogical Implications of the Bilingual Tandem Analyser

    ERIC Educational Resources Information Center

    Schwienhorst, Klaus; Borgia, Alexandre

    2006-01-01

    Tandem learning is the collaborative learning partnership of two language learners with complementary language combinations, for example an Irish student learning German and a German student learning English. One of the major principles in tandem learning, apart from reciprocity and learner autonomy, is balanced bilingualism. While learners may…

  7. The Shaft Torque of a Tandem Axial-Piston Pump

    E-print Network

    Manring, Noah D.

    The Shaft Torque of a Tandem Axial- Piston Pump Noah D. Manring Viral S. Mehta Mechanical of this study is to identify the best indexed position of two rotating groups within a tandem axial-piston pump characteristics of the pump, other vibration aspects of the machine are also expected to be reduced. In particular

  8. Tandem acoustic modeling in large-vocabulary recognition

    Microsoft Academic Search

    Daniel P. W. Ellis; Rita Singh; Sunil Sivadas

    2001-01-01

    In the tandem approach to modeling the acoustic signal, a neural-net preprocessor is first discriminatively trained to estimate posterior probabilities across a phone set. These are then used as feature inputs for a conventional hidden Markov model (HMM) based speech recognizer, which relearns the associations to subword units. We apply the tandem approach to the data provided for the first

  9. Linearbeschleuniger und Tandem-van-de-Graaffs: Werkzeuge der Schwerionenforschung

    NASA Astrophysics Data System (ADS)

    Brix, P.; Ingwersen, H.; Jaeschke, E.; Repnow, R.

    1980-06-01

    The basic principles of dc-tandem and high-frequency linear accelerator are discussed by referring to the pioneering work of H. Kallmann and R. Wideröe. The 30 MV Supertandem in Daresbury, the Heidelberg combination of tandem and linac, and the universal linear accelerator Unilac of the GSI at Darmstadt serve as examples of modern heavy-ion accelerators.

  10. Simple tandem DNA repeats and human genetic disease

    Microsoft Academic Search

    G. R. Sutherland; R. I. Richards

    1995-01-01

    The human genome contains many repeated DNA sequences that vary in complexity of repeating unit from a single nucleotide to a whole gene. The repeat sequences can be widely dispersed or in simple tandem arrays. Arrays of up to 5 or 6 nt are known as simple tandem repeats, and these are widely dispersed and highly polymorphic. Members of one

  11. Form-Focused Interaction in Online Tandem Learning

    ERIC Educational Resources Information Center

    O'Rourke, Breffni

    2005-01-01

    Tandem language learning--a configuration involving pairs of learners with complementary target/native languages--is an underexploited but potentially very powerful use of computer-mediated communication (CMC) in second-language pedagogy. Tandem offers the benefits of authentic, culturally grounded interaction, while also promoting a pedagogical…

  12. APPLICATION NOTE SILVER Helps Assign Peptides to Tandem

    E-print Network

    Roth, Frederick

    Pharmacology, Harvard Medical School, Boston, Massachusetts, USA Tandem mass spectrometry is commonly used" peptide-spectrum matches (PSMs). SILVER is web-based software that assists manual curation of tandem mass at http://llama.med.harvard.edu/Software.html. (J Am Soc Mass Spectrom 2004, 15, 910­912) © 2004 American

  13. Monolithic Tandem Organic Photovoltaic Cell Utilizing Transparent Carbon Nanotube Interlayer

    Microsoft Academic Search

    Kamil Mielczarek; Senku Tanaka; Raquel Ovalle Robles; Alexander Kuznetsov; Brian Wang; Dean Hsu; Ray Baughman; Anvar Zakhidov

    2009-01-01

    We demonstrate an organic photovoltaic multijunction cell in a monolithic parallel tandem structure in which transparent multi and single-walled nanotube sheets are used as an interlayer electrode connecting two cells; polymeric photovoltaic (PPV) cell or organic low molecular PV (OPV). Each cell is characterized independently and the short circuit current density of the tandem is shown to be larger than

  14. The Bucharest FN Tandem Accelerator: Modernization and Development

    NASA Astrophysics Data System (ADS)

    Dobrescu, S.; Mosu, D. V.; Moisa, D.; Papureanu, S.

    2009-03-01

    The Bucharest FN tandem accelerator, installed in 1973 and upgraded in 1983 to 9 MV, has been used for atomic and nuclear physics studies as well as for different applications using accelerated ion beams. In the last three years a program of modernization of the tandem accelerator including the replacement of the old accelerator equipment by new ones, installation of a pelletron system for the Van de Graaff generator and installation of new negative ion injectors was undertaken. In parallel a development of the tandem accelerator was started. In 2009, a beam pulsing system in the nanosecond range is scheduled to be installed. All these works aimed to transform the tandem accelerator in a reliable and efficient tool for research and applications are presented. The main lines of the research program at the Bucharest tandem accelerator are shortly presented too.

  15. Electronic Tandem Language Learning (eTandem): A Third Approach to Second Language Learning for the 21st Century

    ERIC Educational Resources Information Center

    Cziko, Gary A.

    2004-01-01

    Tandem language learning occurs when two learners of different native languages work together to help each other learn the other language. First used in face-to-face contexts, Tandem is now increasingly being used by language-learning partners located in different countries who are linked via various forms of electronic communication, a context…

  16. Axisymmetric Tandem Mirrors: Stabilization and Confinement Studies

    SciTech Connect

    Post, R.F.; Fowler, T.K.; Bulmer, R.; Byers, J.; Hua, D.; Tung, L. [Lawrence Livermore National Laboratory (United States)

    2005-01-15

    The 'Kinetic Stabilizer' has been proposed as a means of MHD stabilizing an axisymmetric tandem mirror system. The K-S concept is based on theoretical studies by Ryutov, confirmed experimentally in the Gas Dynamic Trap experiment in Novosibirsk. In the K-S beams of ions are directed into the end of an 'expander' region outside the outer mirror of a tandem mirror. These ions, slowed, stagnated, and reflected as they move up the magnetic gradient, produce a low-density stabilizing plasma.At the Lawrence Livermore National Laboratory we have been conducting theoretical and computational studies of the K-S Tandem Mirror. These studies have employed a low-beta code written especially to analyze the beam injection/stabilization process,and a new code SYMTRAN (by Hua and Fowler)that solves the coupled radial and axial particle and energy transport in a K-S T-M. Also, a 'legacy' MHD stability code, FLORA, has been upgraded and employed to benchmark the injection/stabilization code and to extend its results to high beta values.The FLORA code studies so far have confirmed the effectiveness of the K-S in stabilizing high-beta (40%) plasmas with stabilizer plasmas the peak pressures of which are several orders of magnitude smaller than those of the confined plasma.Also the SYMTRAN code has shown D-T plasma ignition from alpha particle energy deposition in T-M regimes with strong end plugging.Our studies have confirmed the viability of the K-S T-M concept with respect to MHD stability and radial and axial confinement. We are continuing these studies in order to optimize the parameters and to examine means for the stabilization of possible residual instability modes, such as drift modes and 'trapped-particle' modes. These modes may in principle be controlled by tailoring the stabilizer plasma distribution and/or the radial potential distribution.In the paper the results to date of our studies are summarized and projected to scope out possible fusion-power versions of the K-S T-M.

  17. The construction of tandem dye-sensitized solar cells from chemically-derived nanoporous photoelectrodes

    E-print Network

    Park, Byungwoo

    The construction of tandem dye-sensitized solar cells from chemically-derived nanoporous Available online 24 October 2014 Keywords: Tandem solar cell Selective etching Dye-sensitized solar cell Nanoporous electrode a b s t r a c t A tandem dye-sensitized solar cell (tandem-DSSC) was synthesized

  18. Classroom Tandem--Outlining a Model for Language Learning and Instruction

    ERIC Educational Resources Information Center

    Karjalainen, Katri; Pörn, Michaela; Rusk, Fredrik; Björkskog, Linda

    2013-01-01

    The aim of this paper is to outline classroom tandem by comparing it with informal tandem learning contexts and other language instruction methods. Classroom tandem is used for second language instruction in mixed language groups in the subjects of Finnish and Swedish as L2. Tandem learning entails that two persons with different mother tongues…

  19. Parametric systems analysis for tandem mirror hybrids

    SciTech Connect

    Lee, J.D.; Chapin, D.L.; Chi, J.W.H.

    1980-09-01

    Fusion fission systems, consisting of fissile producing fusion hybrids combining a tandem mirror fusion driver with various blanket types and net fissile consuming LWR's, have been modeled and analyzed parametrically. Analysis to date indicates that hybrids can be competitive with mined uranium when U/sub 3/O/sub 8/ cost is about 100 $/lb., adding less than 25% to present day cost of power from LWR's. Of the three blanket types considered, uranium fast fission (UFF), thorium fast fission (ThFF), and thorium fission supressed (ThFS), the ThFS blanket has a modest economic advantage under most conditions but has higher support ratios and potential safety advantages under all conditions.

  20. Protein Sequencing with Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Ziady, Assem G.; Kinter, Michael

    The recent introduction of electrospray ionization techniques that are suitable for peptides and whole proteins has allowed for the design of mass spectrometric protocols that provide accurate sequence information for proteins. The advantages gained by these approaches over traditional Edman Degradation sequencing include faster analysis and femtomole, sometimes attomole, sensitivity. The ability to efficiently identify proteins has allowed investigators to conduct studies on their differential expression or modification in response to various treatments or disease states. In this chapter, we discuss the use of electrospray tandem mass spectrometry, a technique whereby protein-derived peptides are subjected to fragmentation in the gas phase, revealing sequence information for the protein. This powerful technique has been instrumental for the study of proteins and markers associated with various disorders, including heart disease, cancer, and cystic fibrosis. We use the study of protein expression in cystic fibrosis as an example.

  1. Tandem Subunits Effectively Constrain GABAA Receptor Stoichiometry and Recapitulate Receptor Kinetics But Are Insensitive to GABAA Receptor-Associated Protein

    PubMed Central

    Boileau, Andrew J.; Pearce, Robert A.; Czajkowski, Cynthia

    2008-01-01

    GABAergic synapses likely contain multiple GABAA receptor subtypes, making postsynaptic currents difficult to dissect. However, even in heterologous expression systems, analysis of receptors composed of ?, ?, and ? subunits can be confounded by receptors expressed from ? and ? subunits alone. To produce recombinant GABAA receptors containing fixed subunit stoichiometry, we coexpressed individual subunits with a “tandem” ?1 subunit linked to a ?2 subunit. Cotransfection of the ?2 subunit with ??-tandem subunits in human embryonic kidney 293 cells produced currents that were similar in their macroscopic kinetics, single-channel amplitudes, and pharmacology to overexpression of the ? subunit with nonlinked ?1 and ?2 subunits. Similarly, expression of ? subunits together with ??-tandem subunits produced receptors having physiological and pharmacological characteristics that closely matched cotransfection of ? with ? subunits. In this first description of tandem GABAA subunits measured with patch-clamp and rapid agonist application techniques, we conclude that incorporation of ??-tandem subunits can be used to fix stoichiometry and to establish the intrinsic kinetic properties of ?1?2 and ?1?2?2 receptors. We used this method to test whether the accessory protein GABAA receptor-associated protein (GABARAP) alters GABAA receptor properties directly or influences subunit composition. In recombinant receptors with fixed stoichiometry, coexpression of GABARAP-enhanced green fluorescent protein (EGFP) fusion protein had no effect on desensitization, deactivation, or diazepam potentiation of GABA-mediated currents. However, in ?1?2?2S transfections in which stoichiometry was not fixed, GABARAP-EGFP altered desensitization, deactivation, and diazepam potentiation of GABA-mediated currents. The data suggest that GABARAP does not alter receptor kinetics directly but by facilitating surface expression of ??? receptors. PMID:16339017

  2. 5. GENERAL VIEW OF UNITEDTOD TWIN TANDEM STEAM ENGINE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. GENERAL VIEW OF UNITED-TOD TWIN TANDEM STEAM ENGINE. - Republic Iron & Steel Company, Youngstown Works, Blooming Mill & Blooming Mill Engines, North of Poland Avenue, Youngstown, Mahoning County, OH

  3. Plasma-wall interactions in tandem mirror machines

    SciTech Connect

    Allen, S.L.

    1984-11-01

    A description is presented of the plasma-surface interactions in thermal-barrier tandem-mirror machines. The thermal-barrier mode of axial confinement is an integral part of a tandem mirror, and it dictates the required plasma conditions, particularly at the surface of the plasma. For this reason, a qualitative discussion of the thermal barrier is presented first in Section 2. A brief description of the experimental configuration used in tandem mirrors to create the thermal barrier is then examined in detail in Section 3; the TMX-U and MFTF-B machines are used as specific examples. In Section 4, the relevant plasma-surface interaction issues are addressed, and experimental results from currently operating tandom mirror machines are included. Section 5 is both a summary and a discussion of future work concerned with plasma-surface interactions in tandem mirrors.

  4. Solar-to-Chemical Energy Conversion with Photoelectrochemical Tandem Cells.

    PubMed

    Sivula, Kevin

    2013-01-01

    Efficiently and inexpensively converting solar energy into chemical fuels is an important goal towards a sustainable energy economy. An integrated tandem cell approach could reasonably convert over 20% of the sun's energy directly into chemical fuels like H2 via water splitting. Many different systems have been investigated using various combinations of photovoltaic cells and photoelectrodes, but in order to be economically competitive with the production of H2 from fossil fuels, a practical water splitting tandem cell must optimize cost, longevity and performance. In this short review, the practical aspects of solar fuel production are considered from the perspective of a semiconductor-based tandem cell and the latest advances with a very promising technology - metal oxide photoelectrochemical tandem cells - are presented. PMID:23574955

  5. Tandem wheel drop-legs for standard truck trailer

    NASA Technical Reports Server (NTRS)

    Cantwell, W.; Selstad, R.

    1970-01-01

    Tandem wheel drop-leg device provides a semitrailer with fore and aft mobility that allows it to be moved without a prime mover. The modified drop-legs have trunnion dual wheels and an adjustable brace.

  6. Finding Approximate Tandem Repeats in Genomic Zohar Yakhini

    E-print Network

    Shamir, Ron

    Dan Geiger § ABSTRACT An efficient algorithm is presented for detecting approxi- mate tandem repeats. Copyright 2004 ACM 1-58113-755-9/04/0003 ...$5.00. Replication slippage, unequal crossing-over and evolution

  7. Finding Approximate Tandem Repeats in Genomic Zohar Yakhini

    E-print Network

    Friedman, Nir

    Dan Geiger § ABSTRACT An efficient algorithm is presented for detecting approxi- mate tandem repeats, California, USA. Copyright 2004 ACM 1-58113-755-9/04/0003 ...$5.00. Replication slippage, unequal crossing

  8. Heavy-ion injection from tandems into an isochronous cyclotron

    SciTech Connect

    LeVine, M.J.; Chasman, C.

    1981-01-01

    A design has been realized for the injection of heavy ion beams generated by the BNL 3-stage tandem facility into a proposed isochronous cyclotron. The tandem beams are bunched into +- 1/sup 0/ R.F. phase (less than or equal to 0.5 nsec) in two stages. The beam is then injected into the cyclotron through a valley, past a hill, and into the next valley on to a stripper foil. Only a single steerer is required to make trajectory corrections for the different beams. Two achromats are used to regulate the tandem potential and to provide phase control. A final section of the injection optics provides matching of transverse phase space to the acceptance of the cyclotron. The calculations use realistic tandem emittances and magnetic fields for the cyclotron based on measurements with a model magnet.

  9. Investigation of flow in centrifugal impeller with tandem inducer

    E-print Network

    Nishida, Akira

    1976-01-01

    INVESTIGATION OF FLOW IN CENTRIFUGAL IMPELLER WITH TANDEM INDUCER A Thesis by AKIRA NISHIDA Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1976... Major Subject: Mechanical Engineering INVESTIGATION OF FLOW IN CENTRIFUGAL IMPELLER WITH TANDEM INDUCER A Thesis by AKIRA NISHIDA P&~ (Chairman of C ittee) (Head of Department) (Member) (Member) Ld 4(? (Member) (Member) August 1976 AOSTRACT...

  10. ADVANCES IN STRAIN BALANCED QUANTUM WELL TANDEM SOLAR CELLS

    Microsoft Academic Search

    A. Ioannides; J. P. Connolly; D. B. Bushnell; C. Calder; G. Hill; J. S Roberts

    The latest work in SB-QWSC tandem solar cells leading to higher efficiencies is presented in this paper. Having demonstrated the benefits of incorporating strain balanced multi-quantum well structures in InGaP\\/GaAs bottom cells further improvement has been implemented on the latest devices. Characterization at higher concentrations was made possible using an increased emitter doping in the tandem top cell. A new

  11. Patterns of tandem repetition in plant whole genome assemblies

    Microsoft Academic Search

    Rafael Navajas-Pérez; Andrew H. Paterson

    2009-01-01

    Tandem repeats often confound large genome assemblies. A survey of tandemly arrayed repetitive sequences was carried out in\\u000a whole genome sequences of the green alga Chlamydomonas\\u000a reinhardtii, the moss Physcomitrella patens, the monocots rice and sorghum, and the dicots Arabidopsis thaliana, poplar, grapevine, and papaya, in order to test how these assemblies deal with this fraction of DNA. Our results

  12. Self-assembled growth of tandem nanostructures based on TiO2 mesoporous/ZnO nanowire arrays and their optoelectronic and photoluminescence properties

    NASA Astrophysics Data System (ADS)

    K?l?ç, Bayram; Çelik, Volkan

    2015-02-01

    Growth of ZnO nanowires within TiO2 mesoporous structures is carried out by hydrothermal method. Structural, optical and thermal characterizations have been carried out by SEM, XRD, EDAX, DTG, TG, PL and UV-Vis spectroscopy. XRD characterization shows that the all diffraction peaks of the tandem nanostructures films can be well indexed to a mixture of hexagonal wurtzite ZnO and anatase TiO2 structures. The UV-Visible absorbance spectrum indicates that the tandem nanostructures based on TiO2 mesoporous/ZnO nanowire arrays have 3.13 eV band gap energy while pure ZnO nanowire and bare TiO2 mesoporous show 3.37 and 3.22 eV band gap energy, respectively. The PL spectra of tandem nanostructures show that the UV, violet and yellow emission peaks appeared at 3.1, 2.6 and 2.3 eV, respectively. It has been shown that from the PL spectra, the enhanced ultraviolet emission of TiO2/ZnO tandem structures is related to the fluorescence resonance energy transfer between TiO2 mesoporous and ZnO nanowires. Thermogravimetric analysis from room temperature to 800 °C has been performed to identify the thermal stability and the amount of tandem TiO2/ZnO structures.

  13. Self-assembled growth of tandem nanostructures based on TiO2 mesoporous/ZnO nanowire arrays and their optoelectronic and photoluminescence properties

    NASA Astrophysics Data System (ADS)

    K?l?ç, Bayram; Çelik, Volkan

    2015-05-01

    Growth of ZnO nanowires within TiO2 mesoporous structures is carried out by hydrothermal method. Structural, optical and thermal characterizations have been carried out by SEM, XRD, EDAX, DTG, TG, PL and UV-Vis spectroscopy. XRD characterization shows that the all diffraction peaks of the tandem nanostructures films can be well indexed to a mixture of hexagonal wurtzite ZnO and anatase TiO2 structures. The UV-Visible absorbance spectrum indicates that the tandem nanostructures based on TiO2 mesoporous/ZnO nanowire arrays have 3.13 eV band gap energy while pure ZnO nanowire and bare TiO2 mesoporous show 3.37 and 3.22 eV band gap energy, respectively. The PL spectra of tandem nanostructures show that the UV, violet and yellow emission peaks appeared at 3.1, 2.6 and 2.3 eV, respectively. It has been shown that from the PL spectra, the enhanced ultraviolet emission of TiO2/ZnO tandem structures is related to the fluorescence resonance energy transfer between TiO2 mesoporous and ZnO nanowires. Thermogravimetric analysis from room temperature to 800 °C has been performed to identify the thermal stability and the amount of tandem TiO2/ZnO structures.

  14. Role negotiation in tandem distance tutorial relationships

    E-print Network

    Paris-Sud XI, Université de

    · Multimodality & distance pedagogy (Decamps, Depover & De Lièvre 2009) · Discourse analysis of tutor to technology-enhanced/ distance teaching contexts · Critical analysis of on-line instructional courseware

  15. Follower ants in a tandem pair are not always naïve

    PubMed Central

    Schultheiss, Patrick; Raderschall, Chloé A; Narendra, Ajay

    2015-01-01

    In addition to foraging individually several species of ants guide nestmates to a goal by tandem running. We found that the Australian ant, Camponotus consobrinus, forages both individually and by tandem running to head to the same goal, nest-specific native Australian trees on which they forage. While paths of solitary foragers and initial paths of tandem followers showed no differences in heading directions or straightness, tandem followers moved at about half the speed of solitary runs. When leaders were experimentally removed, follower ants initially engaged in a systematic search around the point of interruption, following which they either (a) headed directly towards and successfully reached the foraging trees, or (b) continued searching or (c) returned to the nest. The high incidence of followers that successfully navigated towards the foraging trees on their own provides strong evidence that many tandem followers are in fact experienced foragers. Detailed analysis of the searching behaviour revealed that even seemingly lost followers displayed a directional bias towards the foraging trees in their search path. Our results show that in a foraging context follower ants in a tandem pair are not always naïve. PMID:26021611

  16. Follower ants in a tandem pair are not always naïve.

    PubMed

    Schultheiss, Patrick; Raderschall, Chloé A; Narendra, Ajay

    2015-01-01

    In addition to foraging individually several species of ants guide nestmates to a goal by tandem running. We found that the Australian ant, Camponotus consobrinus, forages both individually and by tandem running to head to the same goal, nest-specific native Australian trees on which they forage. While paths of solitary foragers and initial paths of tandem followers showed no differences in heading directions or straightness, tandem followers moved at about half the speed of solitary runs. When leaders were experimentally removed, follower ants initially engaged in a systematic search around the point of interruption, following which they either (a) headed directly towards and successfully reached the foraging trees, or (b) continued searching or (c) returned to the nest. The high incidence of followers that successfully navigated towards the foraging trees on their own provides strong evidence that many tandem followers are in fact experienced foragers. Detailed analysis of the searching behaviour revealed that even seemingly lost followers displayed a directional bias towards the foraging trees in their search path. Our results show that in a foraging context follower ants in a tandem pair are not always naïve. PMID:26021611

  17. Analysis of flavonoids: tandem mass spectrometry, computational methods, and NMR.

    PubMed

    March, Raymond; Brodbelt, Jennifer

    2008-12-01

    Due to the increasing understanding of the health benefits and chemopreventive properties of flavonoids, there continues to be significant effort dedicated to improved analytical methods for characterizing the structures of flavonoids and monitoring their levels in fruits and vegetables, as well as developing new approaches for mapping the interactions of flavonoids with biological molecules. Tandem mass spectrometry (MS/MS), particularly in conjunction with liquid chromatography (LC), is the dominant technique that has been pursued for elucidation of flavonoids. Metal complexation strategies have proven to be especially promising for enhancing the ionization of flavonoids and yielding key diagnostic product ions for differentiation of isomers. Of particular value is the addition of a chromophoric ligand to allow the application of infrared (IR) multiphoton dissociation as an alternative to collision-induced dissociation (CID) for the differentiation of isomers. CID, including energy-resolved methods, and nuclear magnetic resonance (NMR) have also been utilized widely for structural characterization of numerous classes of flavonoids and development of structure/activity relationships.The gas-phase ion chemistry of flavonoids is an active area of research particularly when combined with accurate mass measurement for distinguishing between isobaric ions. Applications of a variety of ab initio and chemical computation methods to the study of flavonoids have been reported, and the results of computations of ion and molecular structures have been shown together with computations of atomic charges and ion fragmentation. Unambiguous ion structures are obtained rarely using MS alone. Thus, it is necessary to combine MS with spectroscopic techniques such as ultraviolet (UV) and NMR to achieve this objective. The application of NMR data to the mass spectrometric examination of flavonoids is discussed. PMID:18855332

  18. The Impact of Genome Triplication on Tandem Gene Evolution in Brassica rapa.

    PubMed

    Fang, Lu; Cheng, Feng; Wu, Jian; Wang, Xiaowu

    2012-01-01

    Whole genome duplication (WGD) and tandem duplication (TD) are both important modes of gene expansion. However, how WGD influences tandemly duplicated genes is not well studied. We used Brassica rapa, which has undergone an additional genome triplication (WGT) and shares a common ancestor with Arabidopsis thaliana, Arabidopsis lyrata, and Thellungiella parvula, to investigate the impact of genome triplication on tandem gene evolution. We identified 2,137, 1,569, 1,751, and 1,135 tandem gene arrays in B. rapa, A. thaliana, A. lyrata, and T. parvula respectively. Among them, 414 conserved tandem arrays are shared by the three species without WGT, which were also considered as existing in the diploid ancestor of B. rapa. Thus, after genome triplication, B. rapa should have 1,242 tandem arrays according to the 414 conserved tandems. Here, we found 400 out of the 414 tandems had at least one syntenic ortholog in the genome of B. rapa. Furthermore, 294 out of the 400 shared syntenic orthologs maintain tandem arrays (more than one gene for each syntenic hit) in B. rapa. For the 294 tandem arrays, we obtained 426 copies of syntenic paralogous tandems in the triplicated genome of B. rapa. In this study, we demonstrated that tandem arrays in B. rapa were dramatically fractionated after WGT when compared either to non-tandem genes in the B. rapa genome or to the tandem arrays in closely related species that have not experienced a recent whole genome polyploidization event. PMID:23226149

  19. Small, octopole-stabilized tandem mirror reactor

    SciTech Connect

    Devoto, R.S.; Baldwin, D.E.; Logan, B.G.; Hamilton, G.W.; Johnston, B.W.

    1984-10-03

    It is shown that the use of octopole stabilization in a tandem mirror allows a large reduction in end-cell length. A novel feature of the method proposed in this report is the placement of the minimum IBI region coonsiderably off axis, thus rendering the core plasma more axisymmetric. The region from the core to the field minimum is bridged by a mirror-confined hot-electron mantle. Low ..beta.., ideal magnetohydrodynamic stability, as evaluated with the interchange criterion, yields an upper limit to the required mantle peak ..beta.. of 78% for a center-cell peak ..beta.. of 75% and barrier peak ..beta.. of 30%. Estimates for the worst type of classical radial diffusion - with stochastic displacements per bounce - show that such radial losses are negligible for this configuration. First estimates of power balance indicate Q approx. 10 for a reactor producing 500 MW of fusion power and Q approx. 25 for one producing 1000 MW, using conservative assumptions regarding mantle ..beta.. requirements and synchrotron radiation losses.

  20. Hot-electron plasma formation and confinement in the tandem mirror experiment-upgrade

    SciTech Connect

    Ress, D.B.

    1988-06-01

    The tandem mirror experiment-upgrade (TMX-U) at the Lawrence Livermore National Laboratory (LLNL) is the first experiment to investigate the thermal-barrier tandem-mirror concept. One attractive feature of the tandem magnetic mirror as a commercial power reactor is that the fusion reactions occur in an easily accessible center-cell. On the other hand, complicated end-cells are necessary to provide magnetohydrodynamic (MHD) stability and improved particle confinement of the center-cell plasma. In these end-cells, enhanced confinement is achieved with a particular axial potential profile that is formed with electron-cyclotron range-of-frequency heating (ECRF heating, ECRH). By modifying the loss rates of electrons at spatially distinct locations within the end-cells, the ECRH can tailor the plasma potential profile in the desired fashion. Specifically, the thermal-barrier concept requires generation of a population of energetic electrons near the midplane of each end-cell. To be effective, the transverse (to the magnetic field) spatial structure of the hot-electron plasma must be fairly uniform. In this dissertation we characterize the spatial structure of the ECRH-generated plasma, and determine how the structure builds up in time. Furthermore, the plasma should efficiently absorb the ECRF power, and a large fraction of the electrons must be well confined near the end-cell midplane. Therefore, we also examine in detail the ECRH power balance, determining how the ECRF power is absorbed by the plasma, and the processes through which that power is confined and lost. 43 refs., 69 figs., 6 tabs.

  1. N, N-Dimethyl Leucines as Novel Isobaric Tandem Mass Tags for Quantitative Proteomics and Peptidomics

    PubMed Central

    Xiang, Feng; Ye, Hui; Chen, Ruibing; Fu, Qiang; Li, Lingjun

    2010-01-01

    Herein we describe the development and application of a set of novel N, N-dimethyl leucine (DiLeu) 4-plex isobaric tandem mass (MS2) tagging reagents with high quantitation efficacy and greatly reduced cost for neuropeptide and protein analysis. DiLeu reagents serve as attractive alternatives for isobaric tag for relative and absolute quantitation (iTRAQ) and tandem mass tags (TMTs) due to their synthetic simplicity, labeling efficiency and improved fragmentation efficiency. DiLeu reagent resembles the general structure of a tandem mass tag in that it contains an amine reactive group (triazine ester) targeting the N-terminus and ?-amino group of the lysine side-chain of a peptide, a balance group, and a reporter group. A mass shift of m/z 145.1 is observed for each incorporated label. Intense a1 reporter ions at m/z 115.1, 116.1, 117.1, and 118.1 are observed for all pooled samples upon MS2. All labeling reagents are readily synthesized from commercially available chemicals with greatly reduced cost. Labels 117 and 118 can be synthesized in one step and labels 115 and 116 can be synthesized in two steps. Both DiLeu and iTRAQ reagents show comparable protein sequence coverage (~43%) and quantitation accuracy (<15%) for tryptically digested protein samples. Furthermore, enhanced fragmentation of DiLeu labeling reagents offers greater confidence in protein identification and neuropeptide sequencing from complex neuroendocrine tissue extracts from a marine model organism, Callinectes sapidus. PMID:20218596

  2. Dynamic analysis of FPSO with a tandem offloading system

    SciTech Connect

    Nishimoto, K.; Brinati, H.L.; Fucatu, C.H. [Univ. of Sao Paulo (Brazil). Dept. of Naval Architecture and Ocean Engineering

    1996-12-31

    Turret-moored tankers have been conceived by the oil industry as a Floating Production Storage and Offloading system (FPSO). The oil stored in ship hull may be offloaded by a shuttle ship connected to the FPSO by a hawser, in a so called tandem system configuration. The problem of dynamic instability, that arises with other ship mooring systems, like single point mooring and spread mooring systems subjected to the environment forces, may also be present with the tandem system. The present paper is concerned with the dynamic analysis of the tandem system. It is an extension of the research that the authors had carried out with the application of a new mathematical model to deal with the SPM dynamics. This formulation is a manoeuvering model specially developed to represent low speed ship motion. Initially presented is the mathematical model that represents the dynamics of the tandem system. Particular emphasis is given to the description of the slow ship dynamics for the two vessels. Simulation of the mathematical model is used to analyze the dynamical behavior of the tandem system. The effects of hawser length, wind and current speeds and wave angle of incidence are investigated.

  3. The Tandem-ALPI-PIAVE accelerator complex of LNL

    SciTech Connect

    Ur, C. A. [INFN Sezione di Padova, 35131 Padova (Italy)

    2013-07-18

    Heavy ion beams are delivered at the Laboratori Nazionali di Legnaro by the accelerator complex Tandem-ALPI-PIAVE. The Tandem XTU is a Van de Graaff accelerator normally operated at terminal voltages of up to about 15 MV. The Tandem accelerator can be operated in stand-alone mode or as an injector for the linac booster ALPI. The linear accelerator ALPI is built of superconducting resonant cavities and consists of a low-beta branch, particularly important for the acceleration of the heavier mass ions, a medium-beta branch, and a high-beta branch. ALPI can be operated also with the PIAVE injector that consists of a superconducting linac and an ECR source. The PIAVE source was mainly used for the acceleration of intense noble gas beams but most recently also a first metallic beam was delivered to the users. The accelerator complex delivers beams of ions from protons to gold in three experimental areas on 11 different beam lines. A rich scientific activity is ongoing at the Tandem-ALPI-PIAVE accelerator complex, beam time being shared between nuclear physics research and applied and interdisciplinary physics research. An overview of the present status and perspectives of the Tandem-ALPI-PIAVE complex and its physics program is given in the present paper.

  4. Design of a new tandem wings hybrid airship

    NASA Astrophysics Data System (ADS)

    Li, Feng; Ye, ZhengYin; Gao, Chao

    2012-10-01

    It is scientifically important science value and engineering promising to develop the buoyancy-lift integrated hybrid airship for high attitude platform. Through the numerical method, a new tandem wings hybrid airship with both higher utility value and economy efficiency was obtained and its total performance and technical parameters were analyzed in detail. In order to further improve the lift-drag characteristics, we implemented the optimization design for aerodynamic configuration of tandem wings hybrid airship via the response surface method. The results indicate that the tandem wings hybrid airship has considerable volume efficiency and higher aerodynamic characteristics. After optimization, the lift-drag ratio of this hybrid airship was increased by 6.08%. In a given gross lift condition, tandem wings hybrid airship may provide more payload and specific productivity. Furthermore, the size of tandem airship is smaller so the demand for skin flexible materials can be reduced. Results of this study could serve as a new approach to designing buoyancy-lifting integrated hybrid airship.

  5. Protein tandem repeats: the more perfect the less structured

    PubMed Central

    Jorda, Julien; Xue, Bin; Uversky, Vladimir N.; Kajava, Andrey V.

    2010-01-01

    We analysed structural properties of protein regions containing arrays of perfect and nearly perfect tandem repeats. Naturally occurring proteins with perfect repeats are practically absent among the proteins with known 3D structures. The great majority of such regions in the Protein DataBank (PDB) are found in the de novo designed proteins. The abundance of natural structured proteins with tandem repeats is inversely correlated with the repeat perfection: the chance to find natural structured proteins in PDB increases with a decrease in the level of repeat perfection. Prediction of intrinsic disorder within the tandem repeats in the SwissProt proteins supports the conclusion that the level of repeat perfection correlates with their tendency to be unstructured. This correlation is valid across the various species and subcellular localizations, although the level of disordered tandem repeats varies significantly between these datasets. On average, in prokaryotes, tandem repeats of cytoplasmic proteins were predicted to be the most structured, whereas in eukaryotes, the most structured portion of the repeats was found in the membrane proteins. Our study supports the hypothesis that in general, the repeat perfection is a sign of recent evolutionary events rather than of exceptional structural and (or) functional importance of the repeat residues. PMID:20553501

  6. Tandem-yeast expression system for engineering and producing unspecific peroxygenase.

    PubMed

    Molina-Espeja, Patricia; Ma, Su; Mate, Diana M; Ludwig, Roland; Alcalde, Miguel

    2015-06-01

    Unspecific peroxygenase (UPO) is a highly efficient biocatalyst with a peroxide dependent monooxygenase activity and many biotechnological applications, but the absence of suitable heterologous expression systems has precluded its use in different industrial settings. Recently, the UPO from Agrocybe aegerita was evolved for secretion and activity in Saccharomyces cerevisiae [8]. In the current work, we describe a tandem-yeast expression system for UPO engineering and large scale production. By harnessing the directed evolution process in S. cerevisiae, the beneficial mutations for secretion enabled Pichia pastoris to express the evolved UPO under the control of the methanol inducible alcohol oxidase 1 promoter. Whilst secretion levels were found similar for both yeasts in flask fermentation (?8mg/L), the recombinant UPO from P. pastoris showed a 27-fold enhanced production in fed-batch fermentation (217mg/L). The P. pastoris UPO variant maintained similar biochemical properties of the S. cerevisiae counterpart in terms of catalytic constants, pH activity profiles and thermostability. Thus, this tandem-yeast expression system ensures the engineering of UPOs to use them in future industrial applications as well as large scale production. PMID:26002501

  7. Statistical Characterization of Ion Trap Tandem Mass Spectra from Doubly Charged Tryptic Peptides

    PubMed Central

    Tabb, David L.; Smith, Lori L.; Breci, Linda A.; Wysocki, Vicki H.; Lin, Dayin; Yates, John R.

    2010-01-01

    Collision-induced dissociation (CID) is a common ion activation technique used to energize mass-selected peptide ions during tandem mass spectrometry. Characteristic fragment ions form from the cleavage of amide bonds within a peptide undergoing CID, allowing the inference of its amino acid sequence. The statistical characterization of these fragment ions is essential for improving peptide identification algorithms and for understanding the complex reactions taking place during CID. An examination of 1465 ion trap spectra from doubly charged tryptic peptides reveals several trends important to understanding this fragmentation process. While less abundant than y ions, b ions are present in sufficient numbers to aid sequencing algorithms. Fragment ions exhibit a characteristic series-specific relationship between their masses and intensities. Each residue influences fragmentation at adjacent amide bonds, with Pro quantifiably enhancing cleavage at its N-terminal amide bond and His increasing the formation of b ions at its C-terminal amide bond. Fragment ions corresponding to a formal loss of ammonia appear preferentially in peptides containing Gln and Asn. These trends are partially responsible for the complexity of peptide tandem mass spectra. PMID:12641236

  8. Flow quality experiment in a tandem nozzle wind tunnel at Mach 3

    NASA Astrophysics Data System (ADS)

    Wu, Jie; Zamre, Pradip; Radespiel, Rolf

    2015-01-01

    In this study, the disturbance characterization and flow quality improvement of a newly designed Tandem Nozzle Mach 3 Wind Tunnel are presented. Firstly, a combined modal analysis is conducted to characterize the freestream disturbances with initial set-up of the settling chamber by using a Pitot probe and a hot-wire anemometry. Then, disturbance reduction in the supersonic wind tunnel is investigated by inserting various damping materials into the settling chamber, while a Pitot probe instrumented with Kulite sensor is employed to monitor the variation of the Pitot pressure fluctuation in the test section. Eventually, an optimized configuration of the settling chamber is determined by a combination of certain damping materials. Afterward, the freestream disturbances are re-characterized with the optimized set-up of the settling chamber, and the disturbance level is found to be significantly reduced. Through this study, valuable experience has been acquired for the disturbance reduction in tandem nozzle type supersonic wind tunnel for the first time, which enhances the feasibility of extending the operation range of conventional hypersonic Ludwieg tubes.

  9. Rules of Stereoselectivity in Tandem Oxidative Polycyclization Reaction with Rhenium(VII) Oxides

    E-print Network

    Keinan, Ehud

    Rules of Stereoselectivity in Tandem Oxidative Polycyclization Reaction with Rhenium(VII) Oxides, Israel ReceiVed April 17, 1998 The tandem oxidative polycyclization reaction with rhenium- (VII) reagents

  10. A new optically pumped tandem magnetometer: principles and experiences

    NASA Astrophysics Data System (ADS)

    Pulz, E.; Jäckel, K.-H.; Linthe, H.-J.

    1999-11-01

    In this paper we describe a new design for an optically pumped tandem magnetometer situated at the GeoForschungsZentrum Potsdam. A tandem magnetometer combines the fast response of a self-oscillating vapour magnetometer with the accuracy of a narrow line Mz-type magnetometer. A newly patented method of coupling the two sensors avoids any stray magnetic fields and so allows a compact design of the instrument itself, as well as facilitating its operation in close proximity to other magnetometers. A prototype Cs-K tandem magnetometer for use in magnetic observatories is described. We then show typical results of a long-term comparison with both a second type of optically pumped magnetometer and an Overhauser proton magnetometer. Finally, a resuméis given of four years of continuous operation of this new type of magnetometer with respect to the data quality produced and its operational reliability.

  11. Advancing tandem solar cells by spectrally selective multilayer intermediate reflectors.

    PubMed

    Hoffmann, Andre; Paetzold, Ulrich W; Zhang, Chao; Merdzhanova, Tsvetelina; Lambertz, Andreas; Ulbrich, Carolin; Bittkau, Karsten; Rau, Uwe

    2014-08-25

    Thin-film silicon tandem solar cells are composed of an amorphous silicon top cell and a microcrystalline silicon bottom cell, stacked and connected in series. In order to match the photocurrents of the top cell and the bottom cell, a proper photon management is required. Up to date, single-layer intermediate reflectors of limited spectral selectivity are applied to match the photocurrents of the top and the bottom cell. In this paper, we design and prototype multilayer intermediate reflectors based on aluminum doped zinc oxide and doped microcrystalline silicon oxide with a spectrally selective reflectance allowing for improved current matching and an overall increase of the charge carrier generation. The intermediate reflectors are successfully integrated into state-of-the-art tandem solar cells resulting in an increase of overall short-circuit current density by 0.7 mA/cm(2) in comparison to a tandem solar cell with the standard single-layer intermediate reflector. PMID:25322181

  12. mreps: efficient and flexible detection of tandem repeats in DNA

    PubMed Central

    Kolpakov, Roman; Bana, Ghizlane; Kucherov, Gregory

    2003-01-01

    The presence of repeated sequences is a fundamental feature of genomes. Tandemly repeated DNA appears in both eukaryotic and prokaryotic genomes, it is associated with various regulatory mechanisms and plays an important role in genomic fingerprinting. In this paper, we describe mreps, a powerful software tool for a fast identification of tandemly repeated structures in DNA sequences. mreps is able to identify all types of tandem repeats within a single run on a whole genomic sequence. It has a resolution parameter that allows the program to identify ‘fuzzy’ repeats. We introduce main algorithmic solutions behind mreps, describe its usage, give some execution time benchmarks and present several case studies to illustrate its capabilities. The mreps web interface is accessible through http://www.loria.fr/mreps/. PMID:12824391

  13. mreps: Efficient and flexible detection of tandem repeats in DNA.

    PubMed

    Kolpakov, Roman; Bana, Ghizlane; Kucherov, Gregory

    2003-07-01

    The presence of repeated sequences is a fundamental feature of genomes. Tandemly repeated DNA appears in both eukaryotic and prokaryotic genomes, it is associated with various regulatory mechanisms and plays an important role in genomic fingerprinting. In this paper, we describe mreps, a powerful software tool for a fast identification of tandemly repeated structures in DNA sequences. mreps is able to identify all types of tandem repeats within a single run on a whole genomic sequence. It has a resolution parameter that allows the program to identify 'fuzzy' repeats. We introduce main algorithmic solutions behind mreps, describe its usage, give some execution time benchmarks and present several case studies to illustrate its capabilities. The mreps web interface is accessible through http://www.loria.fr/mreps/. PMID:12824391

  14. A tandem mirror plasma source for hybrid plume plasma studies

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Chang, F. R.; Miller, R. H.; Wenzel, K. W.; Krueger, W. A.

    1985-01-01

    A tandem mirror device to be considered as a hot plasma source for the hybrid plume rocket concept is discussed. The hot plamsa from this device is injected into an exhaust duct, which will interact with an annular hypersonic layer of neutral gas. The device can be used to study the dynamics of the hybrid plume, and to verify the numerical predictions obtained with computer codes. The basic system design is also geared towards low weight and compactness, and high power density at the exhaust. The basic structure of the device consists of four major subsystems: (1) an electric power supply; (2) a low temperature, high density plasma gun, such as a stream gun, an MPD source or gas cell; (3) a power booster in the form of a tandem mirror machine; and (4) an exhaust nozzle arrangement. The configuration of the tandem mirror section is shown.

  15. Silicon based tandem cells: novel photocathodes for hydrogen production.

    PubMed

    Calvet, W; Murugasen, E; Klett, J; Kaiser, B; Jaegermann, W; Finger, F; Hoch, S; Blug, M; Busse, J

    2014-06-28

    A photovoltaic tandem cell made of amorphous silicon (a-Si) and microcrystalline silicon (?c-Si) was investigated as a photocathode for hydrogen evolution in a photoelectrochemical device. The electronic and electrochemical properties of the samples were characterized using X-ray photoemission spectroscopy (XPS) and cyclic voltammetry (CV), whereas the morphology of the surface in contact with the electrolyte was investigated by scanning electron microscopy (SEM). The electric efficiency of the tandem cell was determined to be 5.2% in a photoelectrochemical (PEC) setup in acidic solution which is only about half of the photovoltaic efficiency of the tandem cell. A significant improvement in efficiency was achieved with platinum as a catalyst which was deposited by physical vapour deposition (PVD) under ultra-high vacuum (UHV) conditions. PMID:24710175

  16. A tandem mirror hybrid plume plasma propulsion facility

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Krueger, W. A.; Peng, S.; Urbahn, J.; Chang-Diaz, F. R.

    1988-01-01

    This paper discusses a novel concept in electrodeless plasma propulsion, in which the materials problems are ameliorated by an electrodeless magnetic confinement scheme borrowed from the tandem mirror approach to controlled thermonuclear fusion. The concept also features a two-stage magnetic nozzle with an annular hypersonic coaxial gas injector near the throat. The nozzle produces hybrid plume by the coaxial injection of hypersonic neutral gas, and the gas layer thus formed protects the material walls from the hot plasma and, through increased collisions, helps detach it from the diverging magnetic field. The tandem mirror plasma propulsion facility is capable of delivering a variable I(sp). The results of numerical simulation of this concept are presented together with those from an experimental tandem-mirror plasma propulsion device.

  17. The query execution engine in Tandem`s new ServerWare SQL product

    SciTech Connect

    Celis, P.; Zeller, H.

    1996-12-31

    Tandem has re-written its SQL compiler and its query execution engine into a new product that will be available on multiple operating systems. The new product uses a novel query execution engine and we will highlight the unique aspects of the new engine. ServerWare SQL uses a data flow and scheduler driven task model to execute queries. Tasks communicate either via in-memory queues or via interprocess communication. Partitioned, pipelined, or independent operations are executed in parallel. By adding new task types the model can be easily extended. Parallelism in a distributed memory environment is implemented as a special {open_quotes}Exchange{close_quotes} task type, as in the Volcano research prototype. Scheduling and load balancing are performed by separate scheduler tasks.

  18. Characterization of Conserved Tandem Donor Sites and Intronic Motifs Required for Alternative Splicing in Corticosteroid Receptor Genes

    PubMed Central

    Qian, Xiaoxiao; Matthews, Laura; Lightman, Stafford; Ray, David; Norman, Michael

    2015-01-01

    Alternative splicing events from tandem donor sites result in mRNA variants coding for additional amino acids in the DNA binding domain of both the glucocorticoid (GR) and mineralocorticoid (MR) receptors. We now show that expression of both splice variants is extensively conserved in mammalian species, providing strong evidence for their functional significance. An exception to the conservation of the MR tandem splice site (an A at position +5 of the MR+12 donor site in the mouse) was predicted to decrease U1 small nuclear RNA binding. In accord with this prediction, we were unable to detect the MR+12 variant in this species. The one exception to the conservation of the GR tandem splice site, an A at position +3 of the platypus GR? donor site that was predicted to enhance binding of U1 snRNA, was unexpectedly associated with decreased expression of the variant from the endogenous gene as well as a minigene. An intronic pyrimidine motif present in both GR and MR genes was found to be critical for usage of the downstream donor site, and overexpression of TIA1/TIAL1 RNA binding proteins, which are known to bind such motifs, led to a marked increase in the proportion of GR? and MR+12. These results provide striking evidence for conservation of a complex splicing mechanism that involves processes other than stochastic spliceosome binding and identify a mechanism that would allow regulation of variant expression. PMID:19819975

  19. The innervation of tandem muscle spindles in the cat neck.

    PubMed

    Richmond, F J; Bakker, G J; Bakker, D A; Stacey, M J

    1986-03-22

    Patterns of innervation were examined in tandem muscle spindles teased from silver-stained muscles of the cat neck. Each tandem spindle was composed of two or more encapsulated receptors linked in series by a shared bag2 fiber. In most tandem spindles, two different types of encapsulation were identified according to differences in their intrafusal fiber content. One type, the b1b2c unit, contained typical bag1, bag2, and chain fibers and was structurally similar to single spindles described in other cat muscles. Each b1b2c unit contained a single primary sensory ending and 1-6 secondary endings. Fusimotor innervation was supplied by many axons. Some fusimotor axons ended in trail ramifications on bag2 and chain fibers, others ended in plates on the bag1 or long chain fiber. The other type of tandem encapsulation, the b2c unit, had only bag2 and chain fibers in its intrafusal fiber bundle. The b2c unit was usually supplied by only one sensory axon that ended on the nucleated part of the intrafusal fiber bundle. This single ending had a more variable terminal morphology than the primary ending in b1b2c units. A few b2c units (3/49) were also supplied by a secondary ending. The fusimotor innervation of the b2c unit was relatively simple. A single pole of the b2c unit was usually supplied by only one to three axons, all ending in trail ramifications. No plate endings were found in b2c units. These morphological specializations suggest that b1b2c and b2c units in tandem spindles differ in both their transductive and fusimotor mechanisms. Thus, the tandem spindle is a specialized structure that may provide additional proprioceptive information beyond that available from single muscle spindles. PMID:2422225

  20. Counter-Rotating Tandem Motor Drilling System

    SciTech Connect

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than that of slim holes. As a result, the research team decided to complete the project, document the tested designs and seek further support for the concept outside of the DOE.

  1. Monolithic parallel tandem organic photovoltaic cell with transparent carbon nanotube interlayer

    Microsoft Academic Search

    S. Tanaka; K. Mielczarek; R. Ovalle-Robles; B. Wang; D. Hsu; A. A. Zakhidov

    2009-01-01

    We demonstrate an organic photovoltaic cell with a monolithic tandem structure in parallel connection. Transparent multiwalled carbon nanotube sheets are used as an interlayer anode electrode for this parallel tandem. The characteristics of front and back cells are measured independently. The short circuit current density of the parallel tandem cell is larger than the currents of each individual cell. The

  2. Tandem junction amorphous semiconductor photovoltaic cell

    DOEpatents

    Dalal, V.L.

    1983-06-07

    A photovoltaic stack comprising at least two p[sup +]i n[sup +] cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p[sup +]i n[sup +] cells. 3 figs.

  3. Tandem junction amorphous semiconductor photovoltaic cell

    DOEpatents

    Dalal, Vikram L. (Newark, DE)

    1983-01-01

    A photovoltaic stack comprising at least two p.sup.+ i n.sup.+ cells in optical series, said cells separated by a transparent ohmic contact layer(s), provides a long optical path for the absorption of photons while preserving the advantageous field-enhanced minority carrier collection arrangement characteristic of p.sup.+ i n.sup.+ cells.

  4. C60/N,N?-bis(1-naphthyl)-N,N?-diphenyl-1,1?-biphenyl-4,4?-diamine:MoO3 as the interconnection layer for high efficient tandem blue fluorescent organic light-emitting diodes

    PubMed Central

    Wu, Xiaoming; Bi, Wentao; Hua, Yulin; Sun, Jin'e; Xiao, Zhihui; Wang, Li; Yin, Shougen

    2013-01-01

    The high efficient tandem blue fluorescent organic light emitting diodes (OLEDs) with the transparent interconnection layer (ICL) of fullerence (C60)/Molybdenum oxide (MoO3)-doped N,N?-bis(1-naphthyl)-N,N?-diphenyl-1,1?-biphenyl-4,4?-diamine (NPB) were presented. A stack consisting of 0.5?nm of LiF and 1?nm of Ca, which is located from C60 to adjacent electron transporting layer is used as an electron injection layer. The experiment results indicate that the luminance of the tandem device is basically equal to that of the traditional single-unit device, but the current density of the tandem device is much less than that of the single-unit device under a same luminance. The current efficiency and the maximal power efficiency of tandem device with LiF/Ca/C60/NPB:MoO3/MoO3-based interconnection layer have been approximately enhanced by 250% and 126%, respectively. In addition, we also analyze that the mechanism of the efficiency enhancement is ascribed to the effective charge separation and transport of the ICL in tandem OLEDs. PMID:23861554

  5. Improved performance of GaAs tunnel diode by embedding InAs quantum dot layer for tandem solar cells

    NASA Astrophysics Data System (ADS)

    Park, Kwang Wook; Kang, Seok Jin; Ravindran, Sooraj; Min, Jung Wook; Lee, Soo Kyung; Park, Min Su; Tak Lee, Yong

    2015-06-01

    GaAs tunnel diodes (TDs) embedded with an InAs quantum dot (QD) layer were grown and their performance was compared with that of TDs without a QD layer. The TDs embedded with a QD layer showed enhanced peak tunnel current density and lower differential resistivity at zero bias compared with the TDs without a QD layer. The samples were then annealed to mimic the overlayer growth process. It was found that the performance degradation after annealing was smaller for the QD-layer-embedded TDs. The improved characteristics of the QD-layer-embedded GaAs TDs make them advantageous for interconnecting unit cells in tandem solar cells.

  6. Routine approach to qualitatively screening 300 pesticides and quantification of those frequently detected in fruit and vegetables using liquid chromatography tandem mass spectrometry (LCMS\\/MS)

    Microsoft Academic Search

    B. Kmellár; L. Abrankó; P. Fodor; S. J. Lehotay

    2010-01-01

    This paper describes an efficient and effective analytical scheme to first screen for 300 pesticides in fruit and vegetables samples using liquid chromatography tandem mass spectrometry (LC-MS\\/MS) with a commercially enhanced product ion method. Then presumed positive extracts are analysed using a quantitative and confirmatory LC-MS\\/MS method optimized for 55 pesticides. A quick, easy, cheap, effective, rugged, and safe (QuEChERS)

  7. Tandemly Arrayed Genes in Vertebrate Genomes and Liqing Zhang2

    E-print Network

    Zhang, Liqing

    Tandemly Arrayed Genes in Vertebrate Genomes Deng Pan1 and Liqing Zhang2 1 Department of Computer a survey of these genes in 11 available vertebrate genomes. TAGs account for an average of about 14% of all genes in these vertebrate genomes, and about 25% of all duplications. The majority of TAGs (72-94%) have

  8. Metallic nanoparticles as intermediate reflectors in tandem solar cells

    Microsoft Academic Search

    Stephan Fahr; Carsten Rockstuhl; Falk Lederer

    2009-01-01

    Tandem thin film solar cells made of amorphous and microcrystalline silicon offer the potential for high conversion efficiencies at low costs. However, their finite thickness imposed by intrinsic materials properties hinders the complete absorption of light and requires smart photon management. We reveal a genuine strategy to use metallic nanoparticles, appropriately tailored to provide a spectrally selective reflection, as an

  9. High efficiency GaAs/Ge monolithic tandem solar cells

    NASA Technical Reports Server (NTRS)

    Tobin, S. P.; Vernon, S. M.; Bajgar, C.; Haven, V. E.; Geoffroy, L. M.; Sanfacon, M. M.; Lillington, D. R.; Hart, R. E., Jr.

    1988-01-01

    Two-terminal monolithic tandem cells consisting of a GaAs solar cell grown epitaxially on a Ge solar cell substrate are very attractive for space applications. Tandem cells of GaAs grown by metal-organic chemical vapor deposition on thin Ge were investigated to address both higher efficiency and reduced weight. Two materials growth issues associated with this heteroepitaxial system, autodoping of the GaAs layers by Ge and diffusion of Ga and As into the Ge substrate, were addressed. The latter appears to result in information of an unintentional p-n junction in the Ge. Early simulator measurements gave efficiencies as high as 21.7 percent for 4 cm2 GaAs/Ge cells, but recent high-altitude testing has given efficiencies of 18 percent. Sources of errors in simulator measurements of two-terminal tandem cells are discussed. A limiting efficiency of about 36 percent for the tandem cell at AMO was calculated. Ways to improve the performance of present cells, primarily by increasing the Isc and Voc of the Ge cell, are proposed.

  10. Verification of automated peptide identifications from proteomic tandem mass spectra

    Microsoft Academic Search

    David B Friedman; Amy-Joan L Ham; David L Tabb

    2006-01-01

    Shotgun proteomics yields tandem mass spectra of peptides that can be identified by database search algorithms. When only a few observed peptides suggest the presence of a protein, establishing the accuracy of the peptide identifications is necessary for accepting or rejecting the protein identification. In this protocol, we describe the properties of peptide identifications that can differentiate legitimately identified peptides

  11. High power tandem-pumped thulium-doped fiber laser.

    PubMed

    Wang, Yao; Yang, Jianlong; Huang, Chongyuan; Luo, Yongfeng; Wang, Shiwei; Tang, Yulong; Xu, Jianqiu

    2015-02-01

    We propose a cascaded tandem pumping technique and show its high power and high efficient operation in the 2-?m wavelength region, opening up a new way to scale the output power of the 2-?m fiber laser to new levels (e.g. 10 kW). Using a 1942 nm Tm3+ fiber laser as the pump source with the co- (counter-) propagating configuration, the 2020 nm Tm3+ fiber laser generates 34.68 W (35.15W) of output power with 84.4% (86.3%) optical-to-optical efficiency and 91.7% (92.4%) slope efficiency, with respect to launched pump power. It provides the highest slope efficiency reported for 2-?m Tm3+-doped fiber lasers, and the highest output power for all-fiber tandem-pumped 2-?m fiber oscillators. This system fulfills the complete structure of the proposed cascaded tandem pumping technique in the 2-?m wavelength region (~1900 nm ? ~1940 nm ? ~2020 nm). Numerical analysis is also carried out to show the power scaling capability and efficiency of the cascaded tandem pumping technique. PMID:25836159

  12. Alkyne hydroacylation: switching regioselectivity by tandem ruthenium catalysis.

    PubMed

    Chen, Qing-An; Cruz, Faben A; Dong, Vy M

    2015-03-11

    By using tandem Ru-catalysis, internal alkynes can be coupled with aldehydes for the synthesis of ?,?-unsaturated ketones. The catalyst promotes alkyne transformations with high regioselectivity, with examples that include the differentiation of a methyl vs ethyl substituent on the alkyne. Mechanistic studies suggest that the regioselectivity results from a selective allene formation that is governed by allylic strain. PMID:25608143

  13. MINIMARS: An attractive small tandem mirror fusion reactor

    Microsoft Academic Search

    L. J. Perkins; B. G. Logan; J. N. Doggett; R. S. Devoto; W. D. Nelson; D. C. Lousteau; G. L. Kulcinski; J. F. Santarius; J. D. Gordon; R. B. Campbell

    1985-01-01

    Through the innovative design of a novel end plug scheme employing octopole MHD stabilization, we present the conceptual design of MINIMARS, a small commercial fusion reactor based on the tandem mirror principle. The current baseline for MINIMARS has a net electric output of 600 MWe and we have configured the design for short construction times, factory-built modules, inherently safe blanket

  14. Instability and transition of flow past two tandem circular cylinders

    Microsoft Academic Search

    Jiro Mizushima; Norihisa Suehiro

    2005-01-01

    The instability and transition of flow past two circular cylinders arranged in tandem are investigated numerically. A steady symmetric flow is realized at small Reynolds numbers, but the flow becomes unstable above a critical Reynolds number and makes a transition to an oscillatory flow. We obtained the symmetric flow numerically and analyze its stability by applying linear stability theory. The

  15. Simple tandem DNA repeats and human genetic disease

    SciTech Connect

    Sutherland, G.R.; Richards, R.I. [Women`s and Children`s Hospital, Adelaide (Australia)

    1995-04-25

    The human genome contains many repeated DNA sequences that vary in complexity of repeating unit from a single nucleotide to a whole gene. The repeat sequences can be widely dispersed or in simple tandem arrays. Arrays of up to 5 or 6 nt are known as simple tandem repeats, and these are widely dispersed and highly polymorphic. Members of one group of the simple tandem repeats, the trinucleotide repeats, can undergo an increase in copy number by a process of dynamic mutation. Dynamic mutations of the CCG trinucleotide give rise to one group of fragile sites on human chromosomes, the rare folate-sensitive group. One member of this group, the fragile X (FRAXA) is responsible for the most common familial form of mental retardation. Another member of the group FRAXE is responsible for a rarer mild form of mental retardation. Similar mutations of AGC repeats give rise to a number of neurological disorders. The expanded repeats are unstable between generations and somatically. The intergenerational instability gives rise to unusual patterns of inheritance - particularly anticipation, the increasing severity and/or earlier age of onset of the disorder in successive generations. Dynamic mutations have been found only in the human species, and possible reasons for this are considered. The mechanism of dynamic mutation is discussed, and a number of observations of simple tandem repeat mutation that could assist in understanding this phenomenon are commented on.

  16. Efficient tandem and triple-junction polymer solar cells.

    PubMed

    Li, Weiwei; Furlan, Alice; Hendriks, Koen H; Wienk, Martijn M; Janssen, René A J

    2013-04-17

    We demonstrate tandem and triple-junction polymer solar cells with power conversion efficiencies of 8.9% and 9.6% that use a newly designed, high molecular weight, small band gap semiconducting polymer and a matching wide band gap polymer. PMID:23544881

  17. A small, octopole-stabilized tandem mirror reactor

    Microsoft Academic Search

    R. S. Devoto; D. E. Baldwin; E. B. Hooper; B. G. Logan; G. W. Hamilton; B. M. Johnston

    1986-01-01

    It is shown that the use of octopole stabilization in a tandem mirror reactor allows a large reduction in end-cell length. A novel feature of the method proposed in this report is the placement of the minimum |B| region considerably off axis, thus rendering the core plasma more axisymmetric. The region from the core to the field minimum is bridged

  18. Production of Arq+ ions with a tandem linear Paul trap

    NASA Astrophysics Data System (ADS)

    Higaki, H.; Nagayasu, K.; Iwai, T.; Ito, K.; Okamoto, H.

    2015-06-01

    A tandem linear Paul trap was used to create highly charged Argon ions by electron impact ionizations. By improving the operation scheme, the production of Ar4+ ions was confirmed. Possible improvements for the future experiments with laser cooled Ca+ ions are suggested.

  19. Bio-olefins from unsaturated fatty acids via tandem catalysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new catalytic route to bio-olefins from unsaturated fatty acids will be described. At the heart of the process, the catalyst apparently functions in a tandem mode by both dynamically isomerizing the positions of double bonds in an aliphatic chain and, subsequently, decarboxylating specific isomers...

  20. Tandem fan applications in advanced STOVL fighter configurations

    NASA Technical Reports Server (NTRS)

    Zola, C. L.; Wilson, S. B., III; Eskey, M. A.

    1984-01-01

    The series/parallel tandem fan engine is evaluated for application in advanced STOVL supersonic fighter aircraft. Options in engine cycle parameters and design of the front fan flow diverter are examined for their effects on engine weight, dimensions, and other factors in integration of the engine with the aircraft. Operation of the engine in high-bypass flow mode during cruise and loiter flight is considered as a means of minimizing fuel consumption. Engine thrust augmentation by burning in the front fan exhaust is discussed. Achievement of very short takeoff with vectored thrust is briefly reviewed for tandem fan engine configurations with vectorable front fan nozzles. Examples are given of two aircraft configuration planforms, a delta-canard, and a forward-swept wing, to illustrate the major features, design considerations, and potential performance of the tandem fan installation in each. Full realization of the advantages of tandem fan propulsion are found to depend on careful selection of the aircraft configuration, since integration requirements can strongly influence the engine performance. Previously announced in STAR as N84-24579

  1. Tandem Fan Applications in Advanced STOVL Fighter Configurations

    NASA Technical Reports Server (NTRS)

    Zola, Charlse L.; Wilson, Samuel B., III; Eskey, Megan A.

    1984-01-01

    The series/parallel tandem fan engine is evaluated for application in advanced STOVL supersonic fighter aircraft. Options in engine cycle parameters and design of the front fan flow diverter are examined for their effects on engine weight, dimensions, and other factors in integration of the engine with the aircraft. Operation of the engine in high-bypass flow mode during cruise and loiter flight is considered as a means of minimizizng fuel consumption. Engine thrust augmentation by burning in the front fan exhaust is discussed. Achievement of very sort takeoff with vectored thrust in briefly reviewed for tandem fan engine configurations with vectorable front fan nozzles. Examples are given of two aircraft configuration planforms, a delta-canard, and a forward-swept wing, to illustrate the major features. design considerations, and potential performance of the tandem fan installation in each. Full realization of the advantages of tandem fan propulsion are found to depend on careful selection of the aircraft configuration, since integration requirements can strongly influence the engine performance.

  2. Dynamics of tandem bubble interaction in a microfluidic channel

    PubMed Central

    Yuan, Fang; Sankin, Georgy; Zhong, Pei

    2011-01-01

    The dynamics of tandem bubble interaction in a microfluidic channel (800?×?21 ?m, W?×?H) have been investigated using high-speed photography, with resultant fluid motion characterized by particle imaging velocimetry. A single or tandem bubble is produced reliably via laser absorption by micron-sized gold dots (6 ?m in diameter with 40 ?m in separation distance) coated on a glass surface of the microfluidic channel. Using two pulsed Nd:YAG lasers at ??=?1064 nm and ?10 ?J/pulse, the dynamics of tandem bubble interaction (individual maximum bubble diameter of 50 ?m with a corresponding collapse time of 5.7 ?s) are examined at different phase delays. In close proximity (i.e., interbubble distance?=?40 ?m or ??=?0.8), the tandem bubbles interact strongly with each other, leading to asymmetric deformation of the bubble walls and jet formation, as well as the production of two pairs of vortices in the surrounding fluid rotating in opposite directions. The direction and speed of the jet (up to 95 m/s), as well as the orientation and strength of the vortices can be varied by adjusting the phase delay. PMID:22088007

  3. IMPLEMENTATION OF PLANARIZING LAYERS IN TANDEM SOLAR CELLS Hamed Achour

    E-print Network

    Candea, George

    IMPLEMENTATION OF PLANARIZING LAYERS IN TANDEM SOLAR CELLS Hamed Achour Under the Supervision temperature for application as an intermediate reflector (ZIR) in micromorph solar cells The ZIR layer should: Fill the amorphous top cell (a-Si:H) "Pinches" to avoid crack formation Possess high transparency near

  4. CHARACTERIZATION OF INTEGRINS AND ASSOCIATED PROTEINS USING MALDI TANDEM MASS

    E-print Network

    Ens, Werner

    CHARACTERIZATION OF INTEGRINS AND ASSOCIATED PROTEINS USING MALDI TANDEM MASS SPECTROMETRY IGOR examined purified integrins and characterized the associated molecular species using MALDI-QqTOF mass transduction pathways OBJECTS : Human 1 and 3 integrin complexes METHOD: MALDI-TOF mass spectrometry #12;Figure

  5. DPF-based japanese phoneme recognition using tandem MLNs

    Microsoft Academic Search

    M. R. A. Kotwal; M. Banik; G. M. M. Islam; M. S. Hossain; F. Hassan; M. M. Hasan; G. Muhammad; M. N. Huda

    2010-01-01

    This paper presents a method for automatic phoneme recognition for Japanese language using tandem MLNs. The method comprises three stages: (i) multilayer neural network (MLN) that converts acoustic features into distinctive phonetic features DPFs, (ii) MLN that combines DPFs and acoustic features as input and generates a 45 dimensional DPF vector with less context effect and (iii) the 45 dimensional

  6. Monolithic Parallel Tandem Organic Photovoltaic Cell with Transparent Carbon Nanotube Interlayer

    NASA Technical Reports Server (NTRS)

    Tanaka, S.; Mielczarek, K.; Ovalle-Robles, R.; Wang, B.; Hsu, D.; Zakhidov, A. A.

    2009-01-01

    We demonstrate an organic photovoltaic cell with a monolithic tandem structure in parallel connection. Transparent multiwalled carbon nanotube sheets are used as an interlayer anode electrode for this parallel tandem. The characteristics of front and back cells are measured independently. The short circuit current density of the parallel tandem cell is larger than the currents of each individual cell. The wavelength dependence of photocurrent for the parallel tandem cell shows the superposition spectrum of the two spectral sensitivities of the front and back cells. The monolithic three-electrode photovoltaic cell indeed operates as a parallel tandem with improved efficiency.

  7. ?-BaB 2O 4 deep UV monolithic walk-off compensating tandem

    NASA Astrophysics Data System (ADS)

    Friebe, J.; Moldenhauer, K.; Rasel, E. M.; Ertmer, W.; Isaenko, L.; Yelisseyev, A.; Zondy, J.-J.

    2006-05-01

    The generation of watt-level cw narrow-linewidth sources at specific deep-UV wavelengths corresponding to atomic cooling transitions usually employs external cavity-enhanced second-harmonic generation (SHG) of moderate-power visible lasers in birefringent materials. Among the oxo-borate materials, barium borate (?-BaB 2O 4 or BBO) combines the highest UV band edge and largest nonlinearity but suffers from large walk-off angles that limits the nonlinear interaction length. Alternative quasi-phase-matched (QPM) ferroelectrics are hardly suited for cavity-enhanced operation due to their much larger UV absorption and associated photo-refractive and thermal lensing effects, in addition to the difficult fabrication of fine-pitch domain gratings for short UV coherence lengths. In this work, we investigate an alternative approach to cw deep-UV generation by employing the low-loss BBO in a monolithic walk-off compensating structure [J.-J. Zondy, Ch. Bonnin, D. Lupinski, J. Opt. Soc. Am. B 20 (2003) 1675] to simultaneously enhance the effective nonlinear coefficient while minimizing the UV beam ellipticity under tight focusing. As a preliminary step to cavity-enhanced operation, and in order to apprehend the design difficulties stemming from the extremely low acceptance angle of BBO, we investigate and analyze the single-pass performance of a Lc = 8 mm monolithic walk-off compensating structure made of 2 optically-contacted BBO plates cut for type-I critically phase-matched SHG of a cw ? = 570.4 nm dye laser. As compared with a bulk crystal of identical length, a sharp UV efficiency enhancement factor of 1.65 has been evidenced with the tandem structure, but at ˜-1 nm from the targeted fundamental wavelength, highlighting the sensitivity of this technique when applied to a highly birefringent material such as BBO. Solutions to angle cut residual errors are identified so as to match accurately more complex periodic-tandem structure performance to any target UV wavelength, opening the prospect for high-power, good beam quality deep-UV cw laser sources for atom cooling and trapping.

  8. Enhanced oil recovery system

    DOEpatents

    Goldsberry, Fred L. (Spring, TX)

    1989-01-01

    All energy resources available from a geopressured geothermal reservoir are used for the production of pipeline quality gas using a high pressure separator/heat exchanger and a membrane separator, and recovering waste gas from both the membrane separator and a low pressure separator in tandem with the high pressure separator for use in enhanced oil recovery, or in powering a gas engine and turbine set. Liquid hydrocarbons are skimmed off the top of geothermal brine in the low pressure separator. High pressure brine from the geothermal well is used to drive a turbine/generator set before recovering waste gas in the first separator. Another turbine/generator set is provided in a supercritical binary power plant that uses propane as a working fluid in a closed cycle, and uses exhaust heat from the combustion engine and geothermal energy of the brine in the separator/heat exchanger to heat the propane.

  9. Propulsive performance of unsteady tandem hydrofoils in a side-by-side configuration

    NASA Astrophysics Data System (ADS)

    Dewey, Peter A.; Quinn, Daniel B.; Boschitsch, Birgitt M.; Smits, Alexander J.

    2014-04-01

    Experimental and analytical results are presented on two identical bio-inspired hydrofoils oscillating in a side-by-side configuration. The time-averaged thrust production and power input to the fluid are found to depend on both the oscillation phase differential and the transverse spacing between the foils. For in-phase oscillations, the foils exhibit an enhanced propulsive efficiency at the cost of a reduction in thrust. For out-of-phase oscillations, the foils exhibit enhanced thrust with no observable change in the propulsive efficiency. For oscillations at intermediate phase differentials, one of the foils experiences a thrust and efficiency enhancement while the other experiences a reduction in thrust and efficiency. Flow visualizations reveal how the wake interactions lead to the variations in propulsive performance. Vortices shed into the wake from the tandem foils form vortex pairs rather than vortex streets. For in-phase oscillation, the vortex pairs induce a momentum jet that angles towards the centerplane between the foils, while out-of-phase oscillations produce vortex pairs that angle away from the centerplane between the foils.

  10. Ganoderma lucidum mycelia enhance innate immunity by activating NF-kappaB.

    PubMed

    Kuo, Mei-Chun; Weng, Ching-Yi; Ha, Choi-Lan; Wu, Ming-Jiuan

    2006-01-16

    Ganoderma lucidum is a popular medicinal mushroom in China and Japan for its immunomodulatory and antitumor effects. The goal of this research is to investigate the effect of dried mycelia of Ganoderma lucidum produced by submerged cultivation on the enhancement of innate immune response. We found that Ganoderma lucidum mycelia (0.2-1.6 mg/ml) stimulated TNF-alpha and IL-6 production after 8h treatment in human whole blood. IFN-gamma release from human whole blood was also enhanced after 3 day-culture with Ganoderma lucidum mycelia (0.2-1.0mg/ml). However, Ganoderma lucidum mycelia did not potentiate nitric oxide production in RAW264.7 cells. To better understand the possible immuno-enhancement mechanisms involved, we focused on nuclear factor (NF)-kappaB activation. Electrophoretic mobility shift assay revealed that the Ganoderma lucidum mycelia (1.6 mg/ml) activated kappaB DNA binding activity in RAW264.7 cells. These results provide supporting evidences for the immunomodulatory effect of Ganoderma lucidum mycelia. PMID:16169168

  11. Trail laying during tandem-running recruitment in the ant Temnothorax albipennis.

    PubMed

    Basari, Norasmah; Laird-Hopkins, Benita C; Sendova-Franks, Ana B; Franks, Nigel R

    2014-07-01

    Tandem running is a recruitment strategy whereby one ant leads a single naïve nest mate to a resource. While tandem running progresses towards the goal, the leader ant and the follower ant maintain contact mainly by tactile signals. In this paper, we investigated whether they also deposit chemical signals on the ground during tandem running. We filmed tandem-running ants and analysed the position of the gasters of leaders and followers. Our results show that leader ants are more likely to press their gasters down to the substrate compared to follower ants, single ants and transporter ants. Forward tandem-run leaders (those moving towards a new nest site) performed such trail-marking procedures three times more often than reverse tandem leaders (those moving towards an old nest site). That leader ants marked the trails more often during forward tandem runs may suggest that it is more important to maintain the bond with the follower ant on forward tandem runs than on reverse tandem runs. Marked trails on the ground may serve as a safety line that improves both the efficiency of tandem runs and their completion rates. PMID:24903681

  12. Comparison of short tandem repeat and variable number tandem repeat genetic markers for quantitative determination of allogeneic bone marrow transplant engraftment

    Microsoft Academic Search

    SA Schichman; P Suess; AM Vertino; PS Gray

    2002-01-01

    Variable number tandem repeats (VNTRs) were among the first genetic markers used to quantitate bone marrow transplant engraftment. The limitations of PCR-based VNTR markers in distinguishing some donor\\/recipient pairs has shown the need for additional genetic markers to analyze engraftment. Short tandem repeats (STRs) provide an excellent tool for this purpose because of their high degree of polymorphism and relatively

  13. Versatile communication strategies among tandem WW domain repeats

    PubMed Central

    Dodson, Emma Joy; Fishbain-Yoskovitz, Vered; Rotem-Bamberger, Shahar

    2015-01-01

    Interactions mediated by short linear motifs in proteins play major roles in regulation of cellular homeostasis since their transient nature allows for easy modulation. We are still far from a full understanding and appreciation of the complex regulation patterns that can be, and are, achieved by this type of interaction. The fact that many linear-motif-binding domains occur in tandem repeats in proteins indicates that their mutual communication is used extensively to obtain complex integration of information toward regulatory decisions. This review is an attempt to overview, and classify, different ways by which two and more tandem repeats cooperate in binding to their targets, in the well-characterized family of WW domains and their corresponding polyproline ligands. PMID:25710931

  14. Single P-N junction tandem photovoltaic device

    DOEpatents

    Walukiewicz, Wladyslaw (Kensington, CA); Ager, III, Joel W. (Berkeley, CA); Yu, Kin Man (Lafayette, CA)

    2011-10-18

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  15. Single P-N junction tandem photovoltaic device

    DOEpatents

    Walukiewicz, Wladyslaw (Kensington, CA); Ager, III, Joel W. (Berkeley, CA); Yu, Kin Man (Lafayette, CA)

    2012-03-06

    A single P-N junction solar cell is provided having two depletion regions for charge separation while allowing the electrons and holes to recombine such that the voltages associated with both depletion regions of the solar cell will add together. The single p-n junction solar cell includes an alloy of either InGaN or InAlN formed on one side of the P-N junction with Si formed on the other side in order to produce characteristics of a two junction (2J) tandem solar cell through only a single P-N junction. A single P-N junction solar cell having tandem solar cell characteristics will achieve power conversion efficiencies exceeding 30%.

  16. Magnet system for a thermal barrier Tandem Mirror Reactor

    SciTech Connect

    Kim, N.S.; Conn, R.W.

    1981-01-01

    The magnet system for a thermal barrier D-D tandem mirror reactor has been studied as part of the UCLA tandem mirror reactor design study SATYR. Three main considerations in designing the SATYR magnet system are to obtain the desired field strength variation throughout the system, to have proper space for plasma and neutron shielding, and to satisfy the MHD stability to achieve maximum central cell /beta/. Due to the importance and the complexity, the 'internal' field reversal magnet is the main concern in the entire magnet system for SATYR. Two different magnet designs, a non-uniform current density solenoid and a higher-order solenoid, are discussed. Coil levitation for the internal field reversal magnet has been analyzed.

  17. Analysis of protein dynamics with tandem fluorescent protein timers.

    PubMed

    Khmelinskii, Anton; Knop, Michael

    2014-01-01

    Fluorescent timers (FTs) are fluorescent proteins that change color with time. FTs can be used as tags to follow protein dynamics in living cells. Recently we described a novel class of FTs called tandem fluorescent protein timers (tFTs). Each tFT is a tandem fusion of two different conventional fluorescent proteins having distinct kinetics of fluorophore maturation. tFTs suitable for studying protein dynamics on different scales can be generated from a broad range of commonly used fluorescent proteins. Here we describe how to establish new tFTs and consider potential pitfalls. We detail a protocol for quantitative fluorescence microscopy imaging and analysis of intracellular protein dynamics with tFTs in the budding yeast Saccharomyces cerevisiae. PMID:24947383

  18. Parametric instabilities during electron cyclotron heating of tandem mirrors

    NASA Technical Reports Server (NTRS)

    Nicholson, D. R.

    1984-01-01

    Electron cyclotron resonance heating is one of the most commonly used methods of heating electrons in the plugs and in the thermal barriers of tandem mirrors. The intense coherent electromagnetic waves used for such heating are susceptible to parametric decay into other modes. Significant growth rates are found for the decay of either ordinary or extraordinary waves into two magnetized electron plasma waves. This and related effects may result in electron heating mechanisms rather different than those assumed in linear ray-tracing calculations. These results may help explain the unusual effects observed during heating of the Phaedrus tandem mirror device. In the general case, these instabilities may be strongly inhibited by density gradients.

  19. Nanopyramid structure for ultrathin c-Si tandem solar cells.

    PubMed

    Li, Guijun; Li, He; Ho, Jacob Y L; Wong, Man; Kwok, Hoi Sing

    2014-05-14

    Recently, ultrathin crystalline silicon solar cells have gained tremendous interest because they are deemed to dramatically reduce material usage. However, the resulting conversion efficiency is still limited by the incomplete light absorption in such ultrathin devices. In this letter, we propose ultrathin a-Si/c-Si tandem solar cells with an efficient light trapping design, where a nanopyramid structure is introduced between the top and bottom cells. The superior light harvesting results in a 48% and 35% remarkable improvement of the short-circuit current density for the top and bottom cells, respectively. Meanwhile, the use of SiOx mixed-phase nanomaterial helps to provide the maximum light trapping without paying the price of reduced electrical performance, and conversion efficiencies of up to 13.3% have been achieved for the ultrathin tandem cell employing only 8 ?m of silicon, which is 29% higher than the result obtained for the planar cell. PMID:24730470

  20. Dye-sensitized solar cell using novel tandem cell structure

    Microsoft Academic Search

    M. Murayama; T. Mori

    2007-01-01

    The authors report a new tandem cell structure for improving the short-circuit performance of a dye-sensitized solar cell. Two dye-sensitized nanocrystalline TiO2 films were placed face-to-face as electrodes. As a counter electrode, a platinum mesh sheet with transmittance was inserted between the electrodes. Two TiO2 anodes were connected in parallel with each other and in series with the Pt-mesh sheet

  1. 27. Bollinger twinchain tandem, pigcasting machine, located at the north ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Bollinger twin-chain tandem, pig-casting machine, located at the north end of the plant. Prior to closing, approximately 40 percent of the plant's: iron production was cast into pigs and sold to foundry customers. The pig-casting machine employed a controller, lime man, trough man, and crane operator. - Central Furnaces, 2650 Broadway, east bank of Cuyahoga River, Cleveland, Cuyahoga County, OH

  2. Traffic Congestion at a Two-Tandem Bottleneck

    Microsoft Academic Search

    Kabsung Kim

    1999-01-01

    Equilibrium queuing patterns are analyzed in the context of a two-tandem bottleneck with two origins and one destination. The individual in the model chooses his\\/her departure time, considering the trade-off between travel time and schedule delay. At equilibrium, no one can alter his\\/her departure time in the sense of the Wardrop principle. Four different configurations are analyzed associated with the

  3. Automatic Quality Assessment of Peptide Tandem Mass Spectra

    Microsoft Academic Search

    Marshall W. Bern; David Goldberg; W. Hayes Mcdonald; John R. Yates III

    2004-01-01

    Motivation: A powerful proteomics methodology couples high-performance liquid chromatography (HPLC) with tandem mass spectrometry and database-search software, such as SEQUEST. Such a set-up, however, produces a large num- ber of spectra, many of which are of too poor quality to be useful. Hence a filter that eliminates poor spectra before the database search can significantly improve throughput and robustness. Moreover,

  4. Investigations into tandem acoustic modeling for the Aurora task

    Microsoft Academic Search

    Daniel P. W. Ellis; Manuel J. Reyes Gomez

    2001-01-01

    In tandem acoustic modeling, signal features are first processed by a discriminantly-trained neural network, then the outputs of this network are treated as the feature inputs to a conventional distribution-modeling Gaussian-mixture model (GMM) speech recognizer. This arrangement achieves relative error rate reduc- tions of 30% or more on the Aurora task, as well as support- ing feature stream combination at

  5. Simulation of Wind Pressure on Two Tandem Tanks

    Microsoft Academic Search

    Saeed-Reza Sabbagh-Yazdi; Farzad Meysami-Azad; Nikos E. Mastorakis

    \\u000a In this work, the set of two dimensional for the incompressible fluid is combined with an subgrid scale (SGS) turbulence viscosity\\u000a turbulence mode. The SGS turbulence viscosity model is applied to simulate the changes in the pressure distributions in two\\u000a storage tanks in tandem arrangement due to the wind flow at supercritical Reynolds number (1.43×108). These two storage tanks are

  6. Crux: rapid open source protein tandem mass spectrometry analysis.

    PubMed

    McIlwain, Sean; Tamura, Kaipo; Kertesz-Farkas, Attila; Grant, Charles E; Diament, Benjamin; Frewen, Barbara; Howbert, J Jeffry; Hoopmann, Michael R; Käll, Lukas; Eng, Jimmy K; MacCoss, Michael J; Noble, William Stafford

    2014-10-01

    Efficiently and accurately analyzing big protein tandem mass spectrometry data sets requires robust software that incorporates state-of-the-art computational, machine learning, and statistical methods. The Crux mass spectrometry analysis software toolkit ( http://cruxtoolkit.sourceforge.net ) is an open source project that aims to provide users with a cross-platform suite of analysis tools for interpreting protein mass spectrometry data. PMID:25182276

  7. Single and Tandem Axialp-i-nNanowire Photovoltaic Devices

    Microsoft Academic Search

    Thomas J. Kempa; Bozhi Tian; Dong Rip Kim; Jinsong Hu; Xiaolin Zheng; Charles M. Lieber

    2008-01-01

    Nanowires represent a promising class of materials for exploring new concepts in solar energy conversion. Here we report the first experimental realization of axial modulation-doped p-i-n and tandem p-i-n+-p+-i-n silicon nanowire (SiNW) photovoltaic elements. Scanning electron microscopy images of selectively etched nanowires demonstrate excellent synthetic control over doping and lengths of distinct regions in the diode structures. Current-voltage (I-V) characteristics

  8. Simple tandem organic photovoltaic cells for improved energy conversion efficiency

    Microsoft Academic Search

    Chunfu Zhang; Shi Wun Tong; Changyun Jiang; E. T. Kang; D. S. H. Chan; Chunxiang Zhu

    2008-01-01

    We proposed and demonstrated a simple tandem structure of organic photovoltaic (PV) cell for efficient light harvesting. In this device structure, a soluble fullerene derivative of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is employed simultaneously to form a bilayer heterojunction PV subcell with the underlying copper phthalocyanine (CuPc) and a bulk heterojunction PV subcell with blended poly(3-hexylthiophene-2,5-diyl) (P3HT). In comparison with

  9. Tandem Repeat-Containing MITEs in the Clam Donax trunculus

    PubMed Central

    Šatovi?, Eva; Plohl, Miroslav

    2013-01-01

    Two distinct classes of repetitive sequences, interspersed mobile elements and satellite DNAs, shape eukaryotic genomes and drive their evolution. Short arrays of tandem repeats can also be present within nonautonomous miniature inverted repeat transposable elements (MITEs). In the clam Donax trunculus, we characterized a composite, high copy number MITE, named DTC84. It is composed of a central region built of up to five core repeats linked to a microsatellite segment at one array end and flanked by sequences holding short inverted repeats. The modular composition and the conserved putative target site duplication sequence AA at the element termini are equivalent to the composition of several elements found in the cupped oyster Crassostrea virginica and in some insects. A unique feature of D. trunculus element is ordered array of core repeat variants, distinctive by diagnostic changes. Position of variants in the array is fixed, regardless of alterations in the core repeat copy number. Each repeat harbors a palindrome near the junction with the following unit, being a potential hotspot responsible for array length variations. As a consequence, variations in number of tandem repeats and variations in flanking sequences make every sequenced element unique. Core repeats may be thus considered as individual units within the MITE, with flanking sequences representing a “cassette” for internal repeats. Our results demonstrate that onset and spread of tandem repeats can be more intimately linked to processes of transposition than previously thought and suggest that genomes are shaped by interplays within a complex network of repetitive sequences. PMID:24317975

  10. Tandem repeat-containing MITEs in the clam Donax trunculus.

    PubMed

    Satovic, Eva; Plohl, Miroslav

    2013-01-01

    Two distinct classes of repetitive sequences, interspersed mobile elements and satellite DNAs, shape eukaryotic genomes and drive their evolution. Short arrays of tandem repeats can also be present within nonautonomous miniature inverted repeat transposable elements (MITEs). In the clam Donax trunculus, we characterized a composite, high copy number MITE, named DTC84. It is composed of a central region built of up to five core repeats linked to a microsatellite segment at one array end and flanked by sequences holding short inverted repeats. The modular composition and the conserved putative target site duplication sequence AA at the element termini are equivalent to the composition of several elements found in the cupped oyster Crassostrea virginica and in some insects. A unique feature of D. trunculus element is ordered array of core repeat variants, distinctive by diagnostic changes. Position of variants in the array is fixed, regardless of alterations in the core repeat copy number. Each repeat harbors a palindrome near the junction with the following unit, being a potential hotspot responsible for array length variations. As a consequence, variations in number of tandem repeats and variations in flanking sequences make every sequenced element unique. Core repeats may be thus considered as individual units within the MITE, with flanking sequences representing a "cassette" for internal repeats. Our results demonstrate that onset and spread of tandem repeats can be more intimately linked to processes of transposition than previously thought and suggest that genomes are shaped by interplays within a complex network of repetitive sequences. PMID:24317975

  11. Optimal design of high-efficiency tandem cells

    NASA Technical Reports Server (NTRS)

    Fan, J. C. C.; Tsaur, B.-Y.; Palm, B. J.

    1982-01-01

    Computer analysis indicates that a substantial increase in solar cell conversion efficiencies can be achieved by using two-cell, multi-bandgap tandem structures instead of single-junction cells. Practical AM1 efficiencies of about 30 percent at one sun and over 30 percent at multiple suns are to be expected. The further increases in efficiency calculated for a three-cell tandem structure are much smaller and may not justify the added complexity. For inexpensive two-cell tandem modules, Si is preferred for the bottom cell, and the top-cell material should have a bandgap of 1.75 to 1.80 eV. The GaAs-AlAs and GaAs-GaP systems are very attractive candidates for the top cell. Significant advances have been achieved in growing GaAs on Ge-coated Si substrates (for the two-terminal, two-cell structure) and in growing free-standing ultrathin GaAs layers (for the two-terminal or four-terminal structures). These advances should be transferable to the GaAs-AlAs and GaAs-GaP systems.

  12. Tandem cylinder aerodynamic sound control using porous coating

    NASA Astrophysics Data System (ADS)

    Liu, Hanru; Azarpeyvand, Mahdi; Wei, Jinjia; Qu, Zhiguo

    2015-01-01

    This study is concerned with the application of porous coatings as a passive flow control method for reducing the aerodynamic sound from tandem cylinders. The aim here is to perform a parametric proof-of-concept study to investigate the effectiveness of porous treatment on bare tandem cylinders to control and regularize the vortex shedding and flow within the gap region between the two bluff bodies, and thereby control the aerodynamic sound generation mechanism. The aerodynamic simulations are performed using 2D transient RANS approach with k - ? turbulence model, and the acoustic computations are carried out using the standard Ffowcs Williams-Hawkings (FW-H) acoustic analogy. Numerical flow and acoustic results are presented for bare tandem cylinders and porous-covered cylinders, with different porosities and thicknesses. Experimental flow and acoustic data are also provided for comparison. Results show that the proper use of porous coatings can lead to stabilization of the vortex shedding within the gap region, reduction of the vortex shedding interaction with the downstream body, and therefore the generation of tonal and broadband noise. It has also been observed that the magnitude and the frequency of the primary tone reduce significantly as a result of the flow regularization. The proposed passive flow-induced noise and vibration control method can potentially be used for other problems involving flow interaction with bluff bodies.

  13. Collision-induced dissociation of corticosteroids in electrospray tandem mass spectrometry and development of a screening method by high performance liquid chromatography/tandem mass spectrometry.

    PubMed

    Antignac, J P; Le Bizec, B; Monteau, F; Poulain, F; André, F

    2000-01-01

    A screening method based on liquid chromatography/electrospray tandem mass spectrometry was developed in order to control the illegal use of corticosteroids as growth promoters in cattle. The objective was the detection of low residue levels of corticosteroids or metabolites in biological matrices. Relative to other studies published on this subject, the present work focused on enhancing specificity and sensitivity. Firstly, fragmentation of corticosteroids by collision-induced dissociation was studied. In positive mode, the losses of H(2)O for each hydroxyl group fixed on the molecule, as well as the loss of HF or HCl for halogenated compounds, were observed. For higher collision energy, fragmentations in the B, C and D rings were induced. The negative mode was found to be more specific, inducing a cleavage of the C(20)-C(21) bond with concomitant loss of formaldehyde (CH(2)O). Secondly, three acquisition methods in the negative mode were studied and evaluated, recorded signals being the parent ion [M + acetate](-) and the two daughter ions, [M - H](-) and [M - H - CH(2)O](-). For dexamethasone, MS/MS instrumental detection limits of fragment ion and neutral loss scans, and of multiple reaction monitoring (MRM), were 250, 20 and 5 pg injected, respectively. The MRM method was then evaluated with the objective of use for the detection of corticosteroid residues in biological samples (urine, hair, muscle) and for a metabolism study. PMID:10623925

  14. Structural and biochemical characterizations of an intramolecular tandem coiled coil protein.

    PubMed

    Shin, Donghyuk; Kim, Gwanho; Kim, Gyuhee; Zheng, Xu; Kim, Yang-Gyun; Lee, Sangho

    2014-12-12

    Coiled coil has served as an excellent model system for studying protein folding and developing protein-based biomaterials. Most designed coiled coils function as oligomers, namely intermolecular coiled coils. However, less is known about structural and biochemical behavior of intramolecular coiled coils where coiled coil domains are covalently linked in one polypeptide. Here we prepare a protein which harbors three coiled coil domains with two short linkers, termed intramolecular tandem coiled coil (ITCC) and characterize its structural and biochemical behavior in solution. ITCC consists of three coiled coil domains whose sequences are derived from Coil-Ser and its domain swapped dimer. Modifications include positioning E (Glu) residue at "e" and K (Lys) at "g" positions throughout heptad repeats to enhance ionic interaction among its constituent coiled coil domains. Molecular modeling of ITCC suggests a compact triple helical bundle structure with the second and the third coiled coil domains forming a canonical coiled coil. ITCC exists as a mixture of monomeric and dimeric species in solution. Small-angle X-ray scattering reveals ellipsoidal molecular envelopes for both dimeric and monomeric ITCC in solution. The theoretically modeled structures of ITCC dock well into the envelopes of both species. Higher ionic strength shifts the equilibrium into monomer with apparently more compact structure while secondary structure remains unchanged. Taken together, our results suggest that our designed ITCC is predominantly monomeric structure through the enhanced ionic interactions, and its conformation is affected by the concentration of ionic species in the buffer. PMID:25446089

  15. Progress in High-Performance PV: Polycrystalline Thin-Film Tandem Cells

    SciTech Connect

    Symko-Davies, M.

    2004-08-01

    The High-Performance Photovoltaic (HiPerf PV) Project was initiated by the U.S. Department of Energy to substantially increase the viability of PV for cost-competitive applications. The goal is that PV will contribute significantly to the U.S. and world energy supply and environmental enhancement in the 21st century. The HiPerf PV Project aims at exploring the ultimate performance limits of existing PV technologies, approximately doubling their sunlight-to-electricity conversion efficiencies during its course, to accelerate and enhance their impact in the marketplace. To accomplish this, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices. This paper will describe progress of the subcontractor and in-house R&D on critical pathways for a PV technology having a high potential to reach cost-competitiveness goals: 25%-efficient, low-cost polycrystalline thin-film tandems for large-area, flat-plate modules.

  16. Monolithic, Ultra-Thin GaInP\\/GaAs\\/GaInAs Tandem Solar Cells

    Microsoft Academic Search

    Mark Wanlass; Phil Ahrenkiel; David Albin; Jeff Carapella; Anna Duda; Keith Emery; Daniel Friedman; John Geisz; Kim Jones; Alan Kibbler; James Kiehl; Sarah Kurtz; William McMahon; Tom Moriarty; Jerry Olson; Aaron Ptak; Manuel Romero; Scott Ward

    2006-01-01

    We present here a new approach to tandem cell design that offers near-optimum subcell bandgaps, as well as other special advantages related to cell fabrication, operation, and cost reduction. Monolithic, ultra-thin GaInP\\/GaAs\\/GaInAs triple-bandgap tandem solar cells use this new approach, which involves inverted epitaxial growth, handle mounting, and parent substrate removal. The optimal ~1-eV bottom subcell in the tandem affords

  17. LipidBlast - in-silico tandem mass spectrometry database for lipid identification

    PubMed Central

    Kind, Tobias; Liu, Kwang-Hyeon; Yup Lee, Do; DeFelice, Brian; Meissen, John K.; Fiehn, Oliver

    2013-01-01

    Current tandem mass spectral libraries for lipid annotations in metabolomics are limited in size and diversity. We provide a freely available computer generated in-silico tandem mass spectral library of 212,516 MS/MS spectra covering 119,200 compounds from 26 lipid compound classes, including phospholipids, glycerolipids, bacterial lipoglycans and plant glycolipids. Platform independence is shown by using tandem mass spectra from 40 different mass spectrometer types including low-resolution and high-resolution instruments. PMID:23817071

  18. Evolution of Tandemly Repeated Sequences: What Happens at the End of an Array?

    Microsoft Academic Search

    Bryant F. McAllister; John H. Werren

    1999-01-01

    .   Tandemly repeated sequences are a major component of the eukaryotic genome. Although the general characteristics of tandem\\u000a repeats have been well documented, the processes involved in their origin and maintenance remain unknown. In this study, a\\u000a region on the paternal sex ratio (PSR) chromosome was analyzed to investigate the mechanisms of tandem repeat evolution. The\\u000a region contains a junction

  19. Tandem Organic Photovoltaic Cells Based on Low-Molecular-Weight Semiconductors

    Microsoft Academic Search

    Tetsuya Taima; Toshihiro Yamanari; Jun Sakai; Yuji Yoshida

    2010-01-01

    Recently, the power conversion efficiency (\\\\mathit{PCE}) of organic photovoltaic (OPV) cells has been improved through increased photocurrent density. To further increase \\\\mathit{PCE}, open circuit voltage (Voc) should also be increased. Here, we report tandem OPV cells based on low-molecular-weight semiconductors evaporated in vacuum. The tandem system produced a high Voc that is proportional to the number of tandem OPV cells.

  20. GaAs(1-x)P(x) high efficiency tandem solar cells

    Microsoft Academic Search

    Matthias E. Nell; Allen M. Barnett

    1985-01-01

    The GaAs(1-x) solar cell on a GaP wafer represents a novel approach for a high efficiency tandem solar cell. These solar cells can be produced on a transparent substrate for a mechanically stacked multijunction tandem solar cell structure. For a tandem solar cell consisting of a GaAs(1-x)P(x) top and a Si bottom solar a theoretical maximum efficiency can be predicted

  1. PTGBase: an integrated database to study tandem duplicated genes in plants.

    PubMed

    Yu, Jingyin; Ke, Tao; Tehrim, Sadia; Sun, Fengming; Liao, Boshou; Hua, Wei

    2015-01-01

    Tandem duplication is a wide-spread phenomenon in plant genomes and plays significant roles in evolution and adaptation to changing environments. Tandem duplicated genes related to certain functions will lead to the expansion of gene families and bring increase of gene dosage in the form of gene cluster arrays. Many tandem duplication events have been studied in plant genomes; yet, there is a surprising shortage of efforts to systematically present the integration of large amounts of information about publicly deposited tandem duplicated gene data across the plant kingdom. To address this shortcoming, we developed the first plant tandem duplicated genes database, PTGBase. It delivers the most comprehensive resource available to date, spanning 39 plant genomes, including model species and newly sequenced species alike. Across these genomes, 54?130 tandem duplicated gene clusters (129?652 genes) are presented in the database. Each tandem array, as well as its member genes, is characterized in complete detail. Tandem duplicated genes in PTGBase can be explored through browsing or searching by identifiers or keywords of functional annotation and sequence similarity. Users can download tandem duplicated gene arrays easily to any scale, up to the complete annotation data set for an entire plant genome. PTGBase will be updated regularly with newly sequenced plant species as they become available. PMID:25797062

  2. Forensic analysis of printing inks using tandem Laser Induced Breakdown Spectroscopy and Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Subedi, Kiran; Trejos, Tatiana; Almirall, José

    2015-01-01

    Elemental analysis, using either LA-ICP-MS or LIBS, can be used for the chemical characterization of materials of forensic interest to discriminate between source materials originating from different sources and also for the association of materials known to originate from the same source. In this study, a tandem LIBS/LA-ICP-MS system that combines the benefits of both LIBS and LA-ICP-MS was evaluated for the characterization of samples of printing inks (toners, inkjets, intaglio and offset.). The performance of both laser sampling methods is presented. A subset of 9 black laser toners, 10 colored (CMYK) inkjet samples, 12 colored (CMYK) offset samples and 12 intaglio inks originating from different manufacturing sources were analyzed to evaluate the discrimination capability of the tandem method. These samples were selected because they presented a very similar elemental profile by LA-ICP-MS. Although typical discrimination between different ink sources is found to be > 99% for a variety of inks when only LA-ICP-MS was used for the analysis, additional discrimination was achieved by combining the elemental results from the LIBS analysis to the LA-ICP-MS analysis in the tandem technique, enhancing the overall discrimination capability of the individual laser ablation methods. The LIBS measurements of the Ca, Fe, K and Si signals, in particular, improved the discrimination for this specific set of different ink samples previously shown to exhibit very similar LA-ICP-MS elemental profiles. The combination of these two techniques in a single setup resulted in better discrimination of the printing inks with two distinct fingerprint spectra, providing information from atomic/ionic emissions and isotopic composition (m/z) for each ink sample.

  3. Interpretation of tandem mass spectra obtained from cyclic nonribosomal peptides.

    PubMed

    Liu, Wei-Ting; Ng, Julio; Meluzzi, Dario; Bandeira, Nuno; Gutierrez, Marcelino; Simmons, Thomas L; Schultz, Andrew W; Linington, Roger G; Moore, Bradley S; Gerwick, William H; Pevzner, Pavel A; Dorrestein, Pieter C

    2009-06-01

    Natural and non-natural cyclic peptides are a crucial component in drug discovery programs because of their considerable pharmaceutical properties. Cyclosporin, microcystins, and nodularins are all notable pharmacologically important cyclic peptides. Because these biologically active peptides are often biosynthesized nonribosomally, they often contain nonstandard amino acids, thus increasing the complexity of the resulting tandem mass spectrometry data. In addition, because of the cyclic nature, the fragmentation patterns of many of these peptides showed much higher complexity when compared to related counterparts. Therefore, at the present time it is still difficult to annotate cyclic peptides MS/MS spectra. In this current work, an annotation program was developed for the annotation and characterization of tandem mass spectra obtained from cyclic peptides. This program, which we call MS-CPA is available as a web tool (http://lol.ucsd.edu/ms-cpa_v1/Input.py). Using this program, we have successfully annotated the sequence of representative cyclic peptides, such as seglitide, tyrothricin, desmethoxymajusculamide C, dudawalamide A, and cyclomarins, in a rapid manner and also were able to provide the first-pass structure evidence of a newly discovered natural product based on predicted sequence. This compound is not available in sufficient quantities for structural elucidation by other means such as NMR. In addition to the development of this cyclic annotation program, it was observed that some cyclic peptides fragmented in unexpected ways resulting in the scrambling of sequences. In summary, MS-CPA not only provides a platform for rapid confirmation and annotation of tandem mass spectrometry data obtained with cyclic peptides but also enables quantitative analysis of the ion intensities. This program facilitates cyclic peptide analysis, sequencing, and also acts as a useful tool to investigate the uncommon fragmentation phenomena of cyclic peptides and aids the characterization of newly discovered cyclic peptides encountered in drug discovery programs. PMID:19413302

  4. Tandem-repeat protein domains across the tree of life

    PubMed Central

    Jernigan, Kristin K.

    2015-01-01

    Tandem-repeat protein domains, composed of repeated units of conserved stretches of 20–40 amino acids, are required for a wide array of biological functions. Despite their diverse and fundamental functions, there has been no comprehensive assessment of their taxonomic distribution, incidence, and associations with organismal lifestyle and phylogeny. In this study, we assess for the first time the abundance of armadillo (ARM) and tetratricopeptide (TPR) repeat domains across all three domains in the tree of life and compare the results to our previous analysis on ankyrin (ANK) repeat domains in this journal. All eukaryotes and a majority of the bacterial and archaeal genomes analyzed have a minimum of one TPR and ARM repeat. In eukaryotes, the fraction of ARM-containing proteins is approximately double that of TPR and ANK-containing proteins, whereas bacteria and archaea are enriched in TPR-containing proteins relative to ARM- and ANK-containing proteins. We show in bacteria that phylogenetic history, rather than lifestyle or pathogenicity, is a predictor of TPR repeat domain abundance, while neither phylogenetic history nor lifestyle predicts ARM repeat domain abundance. Surprisingly, pathogenic bacteria were not enriched in TPR-containing proteins, which have been associated within virulence factors in certain species. Taken together, this comparative analysis provides a newly appreciated view of the prevalence and diversity of multiple types of tandem-repeat protein domains across the tree of life. A central finding of this analysis is that tandem repeat domain-containing proteins are prevalent not just in eukaryotes, but also in bacterial and archaeal species. PMID:25653910

  5. Tandem-repeat protein domains across the tree of life.

    PubMed

    Jernigan, Kristin K; Bordenstein, Seth R

    2015-01-01

    Tandem-repeat protein domains, composed of repeated units of conserved stretches of 20-40 amino acids, are required for a wide array of biological functions. Despite their diverse and fundamental functions, there has been no comprehensive assessment of their taxonomic distribution, incidence, and associations with organismal lifestyle and phylogeny. In this study, we assess for the first time the abundance of armadillo (ARM) and tetratricopeptide (TPR) repeat domains across all three domains in the tree of life and compare the results to our previous analysis on ankyrin (ANK) repeat domains in this journal. All eukaryotes and a majority of the bacterial and archaeal genomes analyzed have a minimum of one TPR and ARM repeat. In eukaryotes, the fraction of ARM-containing proteins is approximately double that of TPR and ANK-containing proteins, whereas bacteria and archaea are enriched in TPR-containing proteins relative to ARM- and ANK-containing proteins. We show in bacteria that phylogenetic history, rather than lifestyle or pathogenicity, is a predictor of TPR repeat domain abundance, while neither phylogenetic history nor lifestyle predicts ARM repeat domain abundance. Surprisingly, pathogenic bacteria were not enriched in TPR-containing proteins, which have been associated within virulence factors in certain species. Taken together, this comparative analysis provides a newly appreciated view of the prevalence and diversity of multiple types of tandem-repeat protein domains across the tree of life. A central finding of this analysis is that tandem repeat domain-containing proteins are prevalent not just in eukaryotes, but also in bacterial and archaeal species. PMID:25653910

  6. Tandem isomerization/telomerization of long chain dienes

    PubMed Central

    Torrente-Murciano, Laura; Nielsen, David J.; Cavell, Kingsley J.; Lapkin, Alexei A.

    2014-01-01

    The first example of a tandem reaction involving double-bond migration in combination with telomerization is reported. Homogeneous and heterogeneous Ru catalysts were employed as isomerization catalysts, and telomerization was realized using a homogeneous Pd(0) precursor complex with a N-heterocyclic carbene (IMes) ligand. Overall conversions approaching 60% were achieved with the best selectivity to telomerization products of 91% attained at 11% conversion. Conversion was markedly higher in the presence of longer-chain alcohol (1-butanol) as the nucleophile (telogen). PMID:24982855

  7. Short tandem repeat sequencing on the 454 platform

    Microsoft Academic Search

    Melissa Scheible; Odile Loreille; Rebecca Just; Jodi Irwin

    To investigate the feasibility of next generation sequencing (NGS) technology for the multiplex detection and sequence production of short tandem repeats (STRs), thirteen STR markers (CSF1PO, D2S441, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D13S317, D16S539, D21S11, D22S1045, TPOX, and vWA) were amplified using an optimized multiplex reaction with primer sequences designed for reduced size amplicons. Each sample multiplex was barcoded with

  8. GaInP/GaAs monolithic tandem concentrator cells

    SciTech Connect

    Friedman, D.J.; Kurtz, S.R.; Bertness, K.A.; Kibbler, A.E.; Kramer, C.; Olson, J.M. [National Renewable Energy Lab., Golden, CO (United States); King, D.L.; Hansen, B.R.; Snyder, J.K. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    This paper discusses design considerations for the recently introduced GaInP/GaAs monolithic tandem concentrator cell. The prototype device achieves a peak efficiency of 30.2% in a range of 140--180 suns, making this the first two-terminal device to demonstrate a verified efficiency exceeding 30%. At 425 suns the efficiency is still above 29%. The authors focus on the issues of grid design, top-cell thickness, and antireflectance coat. They also examine ways in which these aspects of the device may be modified to provide further performance improvements for future devices.

  9. Optimization of tandem-structured dye-sensitized solar cell

    Microsoft Academic Search

    Masatoshi Yanagida; Nobuko Onozawa-Komatsuzaki; Mitsuhiko Kurashige; Kazuhiro Sayama; Hideki Sugihara

    2010-01-01

    We optimized tandem-structured dye-sensitized solar cells (T-DSSCs) that consist of a N719-sensitized UV–visible-responsive top cell and a black dye-sensitized near-infrared-responsive bottom cell. The relationship between the thickness (dT) of TiO2 film in the top cell and the performance of T-DSSC was examined both for parallel and series T-DSSCs. The optimized parallel T-DSSC gave the photovoltaic conversion efficiency (?) of 10.6%

  10. Current- and lattice-matched tandem solar cell

    DOEpatents

    Olson, J.M.

    1985-10-21

    A multijunction (cascade) tandem photovoltaic solar cell device is fabricated of a Ga/sub x/In/sub 1-x/P (0.505 equal to or less than x equal to or less than 0.515) top cell semiconductor lattice-matched to a GaAs bottom cell semiconductor at a low resistance heterojunction, preferably a p/sup +//n/sup +/ heterojunction between the cells. The top and bottom cells are both lattice-matched and current-matched for high efficiency solar radiation conversion to electrical energy.

  11. Present status of tandem mirrors and their prospects

    SciTech Connect

    Tamano, Teruo [Univ. of Tsukuba, Ibaraki (Japan)

    1995-04-01

    Recent tandem mirror operations are summarized. These include potential formation without sloshing ion beam injection, MHD stability, axial potential confinement, and radial transport. As a result of potential plugging, ion temperatures of 10 keV are achieved. Beta values of 14% are also observed, and thermonuclear fusion neutrons are detected. Suppression of drift waves due to ExB shear flows is identified as a key factor for good radial confinement. Work to be done in present-day devices and future prospects are discussed. 7 refs., 11 figs.

  12. Tandem mass spectrometry data quality assessment by self-convolution

    PubMed Central

    Choo, Keng Wah; Tham, Wai Mun

    2007-01-01

    Background Many algorithms have been developed for deciphering the tandem mass spectrometry (MS) data sets. They can be essentially clustered into two classes. The first performs searches on theoretical mass spectrum database, while the second based itself on de novo sequencing from raw mass spectrometry data. It was noted that the quality of mass spectra affects significantly the protein identification processes in both instances. This prompted the authors to explore ways to measure the quality of MS data sets before subjecting them to the protein identification algorithms, thus allowing for more meaningful searches and increased confidence level of proteins identified. Results The proposed method measures the qualities of MS data sets based on the symmetric property of b- and y-ion peaks present in a MS spectrum. Self-convolution on MS data and its time-reversal copy was employed. Due to the symmetric nature of b-ions and y-ions peaks, the self-convolution result of a good spectrum would produce a highest mid point intensity peak. To reduce processing time, self-convolution was achieved using Fast Fourier Transform and its inverse transform, followed by the removal of the "DC" (Direct Current) component and the normalisation of the data set. The quality score was defined as the ratio of the intensity at the mid point to the remaining peaks of the convolution result. The method was validated using both theoretical mass spectra, with various permutations, and several real MS data sets. The results were encouraging, revealing a high percentage of positive prediction rates for spectra with good quality scores. Conclusion We have demonstrated in this work a method for determining the quality of tandem MS data set. By pre-determining the quality of tandem MS data before subjecting them to protein identification algorithms, spurious protein predictions due to poor tandem MS data are avoided, giving scientists greater confidence in the predicted results. We conclude that the algorithm performs well and could potentially be used as a pre-processing for all mass spectrometry based protein identification tools. PMID:17880728

  13. Strongly-localized ballooning modes in an axisymmetric tandem mirror

    SciTech Connect

    D'Ippolito, D.A.; Myra, J.R.

    1981-12-01

    A simple model of an axisymmetric tandem mirror without thermal barriers is employed to study the stability of ballooning modes which are confined to the central mirror cell. The central cell is treated as long-thin with isotropic pressure, while the end plug is modeled by a line-tying boundary condition. The scaling of ..beta../sub c/ with the mirror ratio R( and the connection length L/sub c/ is computed, and the sensitivity of these results to the magnetic field profile chosen is discussed.

  14. 21 CFR 862.1055 - Newborn screening test system for amino acids, free carnitine, and acylcarnitines using tandem...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...screening test system for amino acids, free carnitine, and acylcarnitines using tandem mass...screening test system for amino acids, free carnitine, and acylcarnitines using tandem mass...screening test system for amino acids, free carnitine, and acylcarnitines using...

  15. 21 CFR 862.1055 - Newborn screening test system for amino acids, free carnitine, and acylcarnitines using tandem...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...screening test system for amino acids, free carnitine, and acylcarnitines using tandem mass...screening test system for amino acids, free carnitine, and acylcarnitines using tandem mass...screening test system for amino acids, free carnitine, and acylcarnitines using...

  16. Tandem acoustic modeling in large-vocabulary recognition Dan Ellis Columbia University & ICSI dpwe@ee.columbia.edu

    E-print Network

    Ellis, Dan

    in a neural net system. · We used CMU's SPINE1 setup, optimized for MFC features, with 2600 context compared 4 feature sets: mfc - standard MFC features plp - comparable PLP features tandem1 - Tandem based

  17. PROBLEMS ENCOUNTERED DURING THE UP-GRADING TRANSFORMATION OF THE FN-TANDEM OF SACLAY

    E-print Network

    Boyer, Edmond

    . There is no indication of any SF6 presence in both cases. (The insulating gas was N2 + C02 + SF6 mixture, with respective1431 PROBLEMS ENCOUNTERED DURING THE UP-GRADING TRANSFORMATION OF THE FN-TANDEM OF SACLAY L Gif-sur-Yvette, France Résumé. 2014 Les problèmes rencontrés lors de transformation du Tandem FN de

  18. MELT DETECTION AND ESTIMATION IN GREENLAND USING TANDEM SEAWINDS AND QUIKSCAT

    E-print Network

    Long, David G.

    MELT DETECTION AND ESTIMATION IN GREENLAND USING TANDEM SEAWINDS AND QUIKSCAT SCATTEROMETERS AND ESTIMATION IN GREENLAND USING TANDEM SEAWINDS AND QUIKSCAT SCATTEROMETERS Brandon R. Hicks Department are used to classify the melt state and estimate melt severity in Greenland. Backscatter measurements

  19. Investigations on a radial compressor tandem-rotor stage with adjustable geometry

    Microsoft Academic Search

    B. Josuhn-Kadner; B. Hoffmann

    1992-01-01

    A radial compressor stage has been investigated experimentally for aerodynamic stage optimization. The rotor consists of a profiled axial inducer and a conventionally designed radial impeller. Inducer and impeller can be locked at different circumferential positions relative to each other thus, forming a tandem wheel with adjustable geometry. Conventional and laser-2-focus system measurements for the tandem-rotor and the stage were

  20. R&D issues in scale-up and manufacturing of amorphous silicon tandem modules

    NASA Astrophysics Data System (ADS)

    Arya, R. R.; Carlson, D. E.; Chen, L. F.; Ganguly, G.; He, M.; Lin, G.; Middya, R.; Wood, G.; Newton, J.; Bennett, M.; Jackson, F.; Willing, F.

    1999-03-01

    R & D on amorphous silicon based tandem junction devices has improved the throughtput, the material utilization, and the performance of devices on commercial tin oxide coated glass. The tandem junction technology has been scaled-up to produce 8.6 Ft2 monolithically integrated modules in manufacturing at the TF1 plant. Optimization of performance and stability of these modules is ongoing.

  1. Origin and Evolution of Tandem Repeats in the Mitochondrial DNA Control Region of Shrikes (Lanius spp.)

    Microsoft Academic Search

    Nicholas I. Mundy; Andreas J. Helbig

    2004-01-01

    The origin and evolution of a 128-bp tandem repeat in the mtDNA control region of shrikes ( Lanius: Aves) were investigated. The tandem repeat is present in only two species, L. excubitor and L. ludovicianus. In contrast to the variation in repeat number in L. ludovicianus, all individuals of three subspecies of L. excubitor had three repeats. Comparative analysis suggests

  2. Achieving High Performance Polymer Tandem Solar Cells via Novel Materials Design

    E-print Network

    Dou, Letian

    2014-01-01

    GaInP/GaInAs/Ge multijunction solar cells. Appl. Phys. Lett.of tandem/multijunction organic solar cells is nontrivial.multijunction cells and more recently adopted by Kim and Janssen [6,44] in organic tandem solar

  3. A Transposable Element can Drive the Concerted Evolution of Tandemly Repetitious DNA

    Microsoft Academic Search

    Dianne Thompson-Stewart; Gary H. Karpen; Allan C. Spradling

    1994-01-01

    Recombination and conversion have been proposed to drive the concerted evolution of tandemly repeated DNA sequences. However, specific correction events within the repeated genes of multicellular organisms have not been observed directly, so their nature has remained speculative. We investigated whether the excision of transposable P elements from tandemly repeated sequences would induce unequal gene conversion. Genetically marked elements located

  4. Assigning Significance to Peptides Identified by Tandem Mass Spectrometry Using Decoy Databases

    E-print Network

    Storey, John D.

    Assigning Significance to Peptides Identified by Tandem Mass Spectrometry Using Decoy Databases, Washington 98195 Received September 18, 2007 Automated methods for assigning peptides to observed tandem mass spectra typically return a list of peptide-spectrum matches, ranked according to an arbitrary score

  5. Effects of Environmental Stress on Stability of Tandem Repeat in Escherichia coli O157:H7

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multilocus variable-number tandem-repeat analysis (MLVA) is used for source tracking Escherichia coli O157:H7 in agricultural environments. Tandem repeats were stable after limited replication but changed after exposure to irradiation, elevated temperatures, and starvation conditions. The pO157 plas...

  6. Negotiation of Meaning and Corrective Feedback in Japanese/English eTandem

    ERIC Educational Resources Information Center

    Bower, Jack; Kawaguchi, Satomi

    2011-01-01

    This paper presents a comparative analysis of corrective feedback provided by participants in an eTandem interaction between university students in Japan and Australia who were learning each other's language. Corrective feedback provided to tandem partners during interaction via text-based Synchronous Computer Mediated Communication (SCMC) is…

  7. Direct Assay of Enzymes in Heme Biosynthesis for the Detection of Porphyrias by Tandem Mass

    E-print Network

    Gelb, Michael

    Direct Assay of Enzymes in Heme Biosynthesis for the Detection of Porphyrias by Tandem Mass porphyria cutanea tarda and hereditary copro- porphyria, respectively. Electrospray ionization tandem mass, and em- ploy commercially available substrates and internal stan- dards. Porphyrias are a group of rare

  8. Analyzing Proteomes and Protein Function Using Graphical Comparative Analysis of Tandem Mass Spectrometry Results

    Microsoft Academic Search

    K. Jill McAfee; Dexter T. Duncan; Michael Assink; Andrew J. Link

    2006-01-01

    Although generating large amounts of proteomic data us- ing tandem mass spectrometry has become routine, there is currently no single set of comprehensive tools for the rigorous analysis of tandem mass spectrometry results given the large variety of possible experimental aims. Cur- rently available applications are typically designed for dis- playing proteins and posttranslational modifications from the point of view

  9. Origin and evolution of tandem repeats in the mitochondrial DNA control region of shrikes (Lanius spp.).

    PubMed

    Mundy, Nicholas I; Helbig, Andreas J

    2004-08-01

    The origin and evolution of a 128-bp tandem repeat in the mtDNA control region of shrikes (Lanius: Aves) were investigated. The tandem repeat is present in only two species, L. excubitor and L. ludovicianus. In contrast to the variation in repeat number in L. ludovicianus, all individuals of three subspecies of L. excubitor had three repeats. Comparative analysis suggests that a short direct repeat, and a secondary structure including the tandem repeat and a downstream inverted repeat, may be important in the origin of the tandem repeat by slipped-strand mispairing and its subsequent turnover. Homogenization of repeat sequences is most simply explained by expansion and contraction of the repeat array. Surprisingly, mtDNA sequences from L. excubitor were found to be paraphyletic with respect to L. ludovicianus. These results show the utility of a comparative analysis for insights into the evolutionary dynamics of mtDNA tandem repeats. PMID:15486698

  10. Numerical investigation & comparison of a tandem-bladed turbocharger centrifugal compressor stage with conventional design

    NASA Astrophysics Data System (ADS)

    Danish, Syed Noman; Qureshi, Shafiq Rehman; EL-Leathy, Abdelrahman; Khan, Salah Ud-Din; Umer, Usama; Ma, Chaochen

    2014-12-01

    Extensive numerical investigations of the performance and flow structure in an unshrouded tandem-bladed centrifugal compressor are presented in comparison to a conventional compressor. Stage characteristics are explored for various tip clearance levels, axial spacings and circumferential clockings. Conventional impeller was modified to tandem-bladed design with no modifications in backsweep angle, meridional gas passage and camber distributions in order to have a true comparison with conventional design. Performance degradation is observed for both the conventional and tandem designs with increase in tip clearance. Linear-equation models for correlating stage characteristics with tip clearance are proposed. Comparing two designs, it is clearly evident that the conventional design shows better performance at moderate flow rates. However; near choke flow, tandem design gives better results primarily because of the increase in throat area. Surge point flow rate also seems to drop for tandem compressor resulting in increased range of operation.

  11. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-print Network

    Asadpour, Reza; Khan, M Ryyan; Alam, Muhammad A

    2015-01-01

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceed...

  12. Evaluating Tandem Language Learning by E-Mail: Report on a Bilateral Project. CLCS Occasional Paper No. 55.

    ERIC Educational Resources Information Center

    Little, David; Ushioda, Ema; Appel, Marie Christine; Moran, John; O'Rourke, Breffni; Schwienhorst, Klaus

    The report details the Irish portion of an experiment in tandem language learning by electronic mail (e-mail). The partners were Trinity College, Dublin (Ireland) and Ruhr University, Bochum (Germany), funded by the European Union within the International E-Mail Tandem Network as part of a two-year project. Tandem language learning is a form of…

  13. Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact on an ocean model

    E-print Network

    Talley, Lynne D.

    Wind stress measurements from the QuikSCAT-SeaWinds scatterometer tandem mission and the impact by the QuikSCAT-SeaWinds scatterometer tandem mission (April­October 2003) and their impact on ocean model simulation. The diurnal variability captured by twice-daily scatterometer wind from the tandem mission

  14. The first tandem, all-exciplex-based WOLED.

    PubMed

    Hung, Wen-Yi; Fang, Guan-Cheng; Lin, Shih-Wei; Cheng, Shuo-Hsien; Wong, Ken-Tsung; Kuo, Ting-Yi; Chou, Pi-Tai

    2014-01-01

    Exploiting our recently developed bilayer interface methodology, together with a new wide energy-gap, low LUMO acceptor (A) and the designated donor (D) layers, we succeeded in fabricating an exciplex-based organic light-emitting diode (OLED) systematically tuned from blue to red. Further optimization rendered a record-high blue exciplex OLED with ?(ext) of 8%. We then constructed a device structure configured by two parallel blend layers of mCP/PO-T2T and DTAF/PO-T2T, generating blue and yellow exciplex emission, respectively. The resulting device demonstrates for the first time a tandem, all-exciplex-based white-light OLED (WOLED) with excellent efficiencies ?(ext): 11.6%, ?(c): 27.7?cd A(-1), and ?(p): 15.8?ml W(-1) with CIE(0.29, 0.35) and CRI 70.6 that are nearly independent of EL intensity. The tandem architecture and blend-layer D/A (1:1) configuration are two key elements that fully utilize the exciplex delay fluorescence, providing a paragon for the use of low-cost, abundant organic compounds en route to commercial WOLEDs. PMID:24895098

  15. The First Tandem, All-exciplex-based WOLED

    NASA Astrophysics Data System (ADS)

    Hung, Wen-Yi; Fang, Guan-Cheng; Lin, Shih-Wei; Cheng, Shuo-Hsien; Wong, Ken-Tsung; Kuo, Ting-Yi; Chou, Pi-Tai

    2014-06-01

    Exploiting our recently developed bilayer interface methodology, together with a new wide energy-gap, low LUMO acceptor (A) and the designated donor (D) layers, we succeeded in fabricating an exciplex-based organic light-emitting diode (OLED) systematically tuned from blue to red. Further optimization rendered a record-high blue exciplex OLED with ?ext of 8%. We then constructed a device structure configured by two parallel blend layers of mCP/PO-T2T and DTAF/PO-T2T, generating blue and yellow exciplex emission, respectively. The resulting device demonstrates for the first time a tandem, all-exciplex-based white-light OLED (WOLED) with excellent efficiencies ?ext: 11.6%, ?c: 27.7 cd A-1, and ?p: 15.8 ml W-1 with CIE(0.29, 0.35) and CRI 70.6 that are nearly independent of EL intensity. The tandem architecture and blend-layer D/A (1:1) configuration are two key elements that fully utilize the exciplex delay fluorescence, providing a paragon for the use of low-cost, abundant organic compounds en route to commercial WOLEDs.

  16. Multipyrene Tandem Probes for Point Mutations Detection in DNA

    PubMed Central

    Kholodar, Svetlana A.; Novopashina, Darya S.; Meschaninova, Mariya I.; Venyaminova, Alya G.

    2013-01-01

    Here we report design, synthesis and characterization of highly sensitive, specific and stable in biological systems fluorescent probes for point mutation detection in DNA. The tandems of 3?- and 5?-mono- and bis-pyrene conjugated oligo(2?-O-methylribonucleotides), protected by 3?-“inverted” thymidine, were constructed and their potential as new instruments for genetic diagnostics was studied. Novel probes have been shown to exhibit an ability to form stable duplexes with DNA target due to the stabilizing effect of multiple pyrene units at the junction. The relationship between fluorescent properties of developed probes, the number of pyrene residues at the tandem junction, and the location of point mutation has been studied. On the basis of the data obtained, we have chosen the probes possessing the highest fluorescence intensity along with the best mismatch discrimination and deletion and insertion detection ability. Application of developed probes for detection of polymorphism C677T in MTHFR gene has been demonstrated on model systems. PMID:24455205

  17. A numerical parametric study on hydrofoil interaction in tandem

    NASA Astrophysics Data System (ADS)

    Kemal, Omer

    2015-01-01

    Understanding the effects of the parameters affecting the interaction of tandem hydrofoil system is a crucial subject in order to fully comprehend the aero/hydrodynamics of any vehicle moving inside a fluid. This study covers a parametric study on tandem hydrofoil interaction in both potential and viscous fluids using iterative Boundary Element Method (BEM) and RANSE. BEM allows a quick estimation of the flow around bodies and may be used for practical purposes to assess the interaction inside the fluid. The produced results are verified by conformal mapping and Finite Volume Method (FVM). RANSE is used for viscous flow conditions to assess the effects of viscosity compared to the inviscid solutions proposed by BEM. Six different parameters are investigated and they are the effects of distance, thickness, angle of attack, chord length, aspect ratio and tapered wings. A generalized 2-D code is developed implementing the iterative procedure and is adapted to generate results. Effects of free surface and cavitation are ignored. It is believed that the present work will provide insight into the parametric interference between hydrofoils inside the fluid

  18. Engineering validamycin production by tandem deletion of ?-butyrolactone receptor genes in Streptomyces hygroscopicus 5008.

    PubMed

    Tan, Gao-Yi; Peng, Yao; Lu, Chenyang; Bai, Linquan; Zhong, Jian-Jiang

    2015-03-01

    Paired homologs of ?-butyrolactone (GBL) biosynthesis gene afsA and GBL receptor gene arpA are located at different positions in genome of Streptomyces hygroscopicus 5008. Inactivation of afsA homologs dramatically decreased biosynthesis of validamycin, an important anti-fungal antibiotic and a critical substrate for antidiabetic drug synthesis, and the deletion of arpA homologs increased validamycin production by 26% (?shbR1) and 20% (?shbR3). By double deletion, the ?shbR1/R3 mutant showed higher transcriptional levels of adpA-H (the S. hygroscopicus ortholog of the global regulatory gene adpA) and validamycin biosynthetic genes, and validamycin production increased by 55%. Furthermore, by engineering a high-producing industrial strain via tandem deletion of GBL receptor genes, validamycin production and productivity were enhanced from 19 to 24 g/L (by 26%) and from 6.7 to 9.7 g/L(-1) d(-1) (by 45%), respectively, which was the highest ever reported. The strategy demonstrated here may be useful to engineering other Streptomyces spp. with multiple pairs of afsA-arpA homologs. PMID:25527439

  19. TOPEX/Poseidon and Jason-1 Formation Flying; Applications of the Tandem Mission Data

    NASA Astrophysics Data System (ADS)

    Srinivasan, M.; Fu, L.

    2001-12-01

    Jason-1 will join a suite of oceanographic satellites in Earth orbit following its planned December 2001 launch from Vandenburg Air Force Base in California. Jason-1 will be positioned along the same groundtrack that TOPEX/Poseidon has faithfully flown for over nine years. After a brief period of Jason-1 measurement calibration and validation, TOPEX/Poseidon will be maneuvered to an interleaved groundtrack, half-way between the tracks of its former path. TOPEX/Poseidon will continue collecting its valuable data in this new orbital position, thereby increasing the altimetry dataset by a factor of two. Jason-1 will remain on the original TOPEX/Poseidon groundtrack and assume its role as the primary source for many researchers and operational entities utilizing this valued oceanographic data. Jason-1 has a primary mission phase of three years, with a projected five year extended life. As long as TOPEX/Poseidon remains operational, this enhanced dual dataset can provide an unprecedented opportunity for improved resolution in ocean surface topography measurement that may never again be possible. The Tandem Mission phase, as this formation-flying period is described, will be a unique and valuable opportunity for many potentially new scientific discoveries and practical applications. These include, but may not be limited to, ocean eddy velocity and interaction with mean currents, Rossby wave dynamics, coastal currents and tides, oceanic internal tides, fisheries management, ship routing, ocean debris tracking, and offshore operations.

  20. GaAsSb-based heterojunction tunnel diodes for tandem solar cell interconnects

    SciTech Connect

    Zolper, J.C.; Klem, J.F.; Plut, T.A.; Tigges, C.P.

    1995-01-01

    We report a new approach to tunnel junctions that employs a pseudomorphic GaAsSb layer to obtain a band alignment at a InGaAs or InAlAs p-n junction favorable for forward bias tunneling. Since the majority of the band offset between GaAsSb and InGaAs or InAlAs is in the valence band, when an GaAsSb layer is placed at an InGaAs or InAlAs p-n junction the tunneling distance is reduced and the tunneling current is increased. For all doping levels studied, the presence of the GaAsSb-layer enhanced the forward tunneling characteristics. In fact, in a InGaAs/GaAsSb tunnel diode a peak tunneling current sufficient for a 1000 sun intercell interconnect was achieved with p = 1.5{times}l0{sup 18} cm{sup -3} while a similarly doped all-InGaAs diode was rectifying. This approach affords a new degree of freedom in designing tunnel junctions for tandem solar cell interconnects. Previously only doping levels could be varied to control the tunneling properties. Our approach relaxes the doping requirements by employing a GaAsSb-based heterojunction.

  1. Tracing isolates of bacterial species by multilocus variable number of tandem repeat analysis (MLVA).

    PubMed

    van Belkum, Alex

    2007-02-01

    All bacterial genomes contain multiple loci of repetitive DNA. Repeat unit sizes and repeat sequences may vary when multiple loci are considered for different isolates of an individual microbial species. Moreover, it has been documented on many occasions that the number of repeat units per locus is a strain-defining parameter. Consequently, there is isolate-specificity in the number of repeats per locus when different strains of a given bacterial species are compared. The experimental assessment of this variability for a number of different loci has been called 'multilocus variable number of tandem repeat analysis' (MLVA). The approach can be supported or extended by locus-specific DNA sequencing for establishing mutations in the individual repeat units, which usually enhances the resolution of the approach considerably. Essentially, MLVA with or without supportive sequencing has been developed for all of the medically relevant bacterial species and can be used effectively for tracing outbreaks or other forms of bacterial dissemination. MLVA is a modern, timely and versatile bacterial typing methodology. PMID:17266711

  2. Effects of tandem and colliding shock waves on the initiation of triaminotrinitrobenzene

    SciTech Connect

    Tarver, C.M.; Urtiew, P.A.; Tao, W.C. [Energetic Materials Center L-282, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [Energetic Materials Center L-282, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    1995-09-01

    The shock initiation of the insensitive high-explosive LX-17, which contains 92.5% triaminotrinitrobenzene and 7.5% Kel-F binder, was studied under simulated accident conditions in which two shock waves interact producing locally high pressures and temperatures. Two experimental geometries were studied using embedded manganin pressure gauges to measure the increases in pressure due to exothermic reaction at various locations as functions of time. These pressure histories were compared to ignition and growth reactive flow model calculations to determine whether a second shock compression of reacting LX-17 caused unusually rapid reaction rates and thus more extreme hazards. One experiment used a tandem flyer plate of aluminum and steel separated by a gap to shock the LX-17 charge, allow it to rarify, and then reshock the damaged charge to even higher pressures. These experiments revealed no significant enhancement of the LX-17 reaction rates under this shock, rarefaction, and reshock loading. The second experiment used a grooved flyer plate to produce a subcritical shock wave in LX-17, which then diverged and collided, producing a Mach stem interaction at the charge axis. The threshold conditions under which the Mach stem grew to detonation were measured. The standard LX-17 ignition and growth model yielded excellent agreement with the pressure gauge records in the Mach stem interaction region. The formation of Mach stem interactions by nearly simultaneous multiple high-velocity impacts was identified as a serious shock initiation hazard for heterogeneous solid explosives.

  3. Confirmation and quantification of clenbuterol in horse urine using liquid chromatography tandem mass spectrometry triple quadrupole.

    PubMed

    Bishop, Jennifer; Heffron, Brendan; Taddei, Lisa; Benoit, Marc; Hurt, Laura; Costello, Sara; Gross, Melissa; Negrusz, Adam

    2015-03-01

    Clenbuterol (CLE) is used in horses as a bronchodilator and for its anabolic steroid-like effects. CLE is a Class 3 drug according to current Association of Racing Commissioners International (ARCI) Uniform Classification Guidelines. The Racing Medication and Testing Consortium recommended a urine CLE threshold of 140 pg/mL after careful scientific review of the results of studies describing the disposition of CLE in the horse and this threshold was adopted by the ARCI. Enzyme-linked immunosorbent assay was previously used to screen samples for CLE in Illinois, but could not detect such low concentrations in urine. Thus, a liquid-liquid extraction of CLE from urine followed by quantification by liquid chromatography-tandem mass spectrometry was developed and validated. Method validation included testing stability, ion suppression and enhancement, precision, accuracy and uncertainty. Intra-, interday and total precision and accuracy were calculated for each control and found to be within the ±15% acceptance range. The Guide to the Expression of Uncertainty in Measurement approach was used to calculate uncertainty, which was 11% at the 95% confidence level. In the past 5 years, only 15 samples were reported as positive for CLE in Illinois. This new method was used in a pilot program to screen and confirm samples received from thoroughbred and harness horses. PMID:25505053

  4. Quantification of peramivir in dog plasma by liquid chromatography/tandem mass spectrometry employing precolumn derivatization.

    PubMed

    Li, Xin; Li, Ying; Wang, Juan; Wang, Lili; Zhong, Wu; Ruan, Jinxiu; Zhang, Zhenqing

    2014-01-01

    Peramivir is a novel influenza neuraminidase inhibitor used for anti-influenza. In this article, a novel method was developed to determine peramivir in dog plasma using a derivatization treatment step to increase the retention time and enhance the signal intensity. The sample preparation consisted of a protein precipitation extraction followed by derivatization with 10M hydrochloric acid-methanol (10:90, v/v) and determined by liquid chromatography coupled with tandem mass spectrometry. The selected reaction monitoring mode of the positive ion was performed and the precursor to the product ion transitions of m/z 343?284 and m/z 299?152 were used to measure the derivative of peramivir and Ro 64-0802 (internal standard, an active metabolite of oseltamivir). The chromatographic separation was achieved using a ZORBAX RX-C8 (2.0mm×150mm×5?m) analytical column with an isocratic mobile phase composed of acetonitrile-water-formic acid (30:70:0.1, v/v/v, 0.2mL/min). The method was linear over a concentration range of 0.25-250ng/mL. The average intra-day/inter-day precision values were 4.04-8.17% and 3.02-7.08%, respectively, while the average accuracy value was 93.99-106.48%. This method has been successfully applied to the preclinical dog research of peramivir following intragastric administration. PMID:24280376

  5. Graph-based modeling of tandem repeats improves global multiple sequence alignment

    PubMed Central

    Szalkowski, Adam M.; Anisimova, Maria

    2013-01-01

    Tandem repeats (TRs) are often present in proteins with crucial functions, responsible for resistance, pathogenicity and associated with infectious or neurodegenerative diseases. This motivates numerous studies of TRs and their evolution, requiring accurate multiple sequence alignment. TRs may be lost or inserted at any position of a TR region by replication slippage or recombination, but current methods assume fixed unit boundaries, and yet are of high complexity. We present a new global graph-based alignment method that does not restrict TR unit indels by unit boundaries. TR indels are modeled separately and penalized using the phylogeny-aware alignment algorithm. This ensures enhanced accuracy of reconstructed alignments, disentangling TRs and measuring indel events and rates in a biologically meaningful way. Our method detects not only duplication events but also all changes in TR regions owing to recombination, strand slippage and other events inserting or deleting TR units. We evaluate our method by simulation incorporating TR evolution, by either sampling TRs from a profile hidden Markov model or by mimicking strand slippage with duplications. The new method is illustrated on a family of type III effectors, a pathogenicity determinant in agriculturally important bacteria Ralstonia solanacearum. We show that TR indel rate variation contributes to the diversification of this protein family. PMID:23877246

  6. Doping control analysis of metamfepramone and two major metabolites using liquid chromatography-tandem mass spectrometry.

    PubMed

    Thevis, Mario; Sigmund, Gerd; Thomas, Andreas; Gougoulidis, Vassilios; Rodchenkov, Grigory; Schänzer, Wilhelm

    2009-01-01

    The sympathomimetic agent metamfepramone (2-dimethylamino-1-phenylpropan-1-one, dimethylpropion) is widely used for the treatment of the common cold or hypotonic conditions. Due to its stimulating properties and its rapid metabolism resulting in major degradation products such as methylpseudoephedrine and methcathinone, it has been considered relevant for doping controls by the World Anti-Doping Agency (WADA). The rapid degradation of the active drug complicates the detection of metamfepramone itself but the metabolites methylpseudoephedrine and methcathinone can be monitored, and the finding of the latter in particular allows the inference of a metamfepramone administration. In order to improve sports drug testing procedures, metamfepramone, methylpseudoephedrine and methcathinone were characterized using electrospray ionization-high resolution/high accuracy mass spectrometry, and a method employing liquid chromatography/tandem mass spectrometry was established that allowed the analysis of these three analytes by direct injection of 2 microL of urine specimens. The assay was validated with regard to specificity, lower limits of detection (2-10 ng mL(-1)), intraday and interday precision (3-17%) and ion suppression/enhancement effects. The developed procedure has been used to verify or falsify suspicious signals observed in routine screening procedures based on gas chromatography/mass spectrometry and yielded an adverse analytical finding concerning a metamfepramone administration in an authentic doping control sample. Although the active drug was not detected, the indicative metabolites methylpseudoephedrine and methcathinone were considered sufficient to infer the application of the prohibited drug. PMID:19661559

  7. Behavior of the plasma in the anchor cell of the GAMMA 10 tandem mirror

    SciTech Connect

    Islam, Md. Khairul; Nakashima, Yousuke; Higashizono, Yuta; Cho, Teruji [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2006-08-01

    Anchor cells of the GAMMA 10 tandem mirror are composed of minimum-B magnetic field configuration. Behavior of the plasma in the anchor cell is studied using puffing gas flow rate (PGFR) modulation and by covering some parts of the flux tube of each anchor cell by conducting plates (APs). Ambient neutral pressure is decreased by PGFR modulation during axial/potential confinement in both cases without and with APs and it is found that both line density (nl{sub EA}) and diamagnetism (dm{sub EA}) of the anchor cell plasma increase. Lower neutral pressure in the minimum-B region is investigated during the floated APs and significant improvement of the GAMMA 10 plasma parameters is observed. Possible explanations of the experimental results are given from the viewpoint of ambient neutral pressure oriented anchor plasma behavior. Probable reasons of enhanced ambient neutral pressure in the anchor cell and adverse effects of these neutrals on GAMMA 10 plasma parameters are also pointed out.

  8. Neutral Beam Injection Experiments and Related Behavior of Neutral Particles in the GAMMA 10 Tandem Mirror

    SciTech Connect

    Nakashima, Y. [Plasma Research Center, University of Tsukuba (Japan); Watanabe, K. [Plasma Research Center, University of Tsukuba (Japan); Higashizono, Y. [Plasma Research Center, University of Tsukuba (Japan); Ohki, T. [Plasma Research Center, University of Tsukuba (Japan); Ogita, T. [Plasma Research Center, University of Tsukuba (Japan); Shoji, M. [National Institute for Fusion Science(Japan); Kobayashi, S. [Institute of Advanced Energy, Kyoto University (Japan); Islam, M.K. [Plasma Research Center, University of Tsukuba (Japan); Kubota, Y. [Plasma Research Center, University of Tsukuba (Japan); Yoshikawa, M. [Plasma Research Center, University of Tsukuba (Japan); Kobayashi, T. [Plasma Research Center, University of Tsukuba (Japan); Yamada, M. [Plasma Research Center, University of Tsukuba (Japan); Murakami, R. [Plasma Research Center, University of Tsukuba (Japan); Cho, T. [Plasma Research Center, University of Tsukuba (Japan)

    2005-01-15

    Results of neutral beam injection (NBI) experiments in the GAMMA 10 tandem mirror plasmas are presented together with the neutral particle behavior observed in the experiments. A hydrogen neural beam was injected into the hot-ion-mode plasmas by using the injector installed in the central-cell for the plasma heating and fueling. High-energy ions produced by NBI were observed and its energy distribution was measured for the first time with a neutral particle analyzer installed in the central-cell. The temporal and spatial behavior of hydrogen was observed with axially aligned H{sub {alpha}} detectors installed from the central midplane to anchor-cell. Enhancement of hydrogen recycling due to the beam injection and the cause of the observed decrease in plasma diamagnetism are discussed. The Monte-Carlo code DEGAS for neutral transport simulation was applied to the GAMMA 10 central-cell and a 3-dimensional simulation was performed in the NBI experiment. Localization of neutral particle during the beam injection is investigated based on the simulation and it was found that the increased recycling due to the beam injection was dominant near the injection port.

  9. Electric transport in 3D photonic crystal intermediate reflectors for micromorph thin-film tandem solar cells

    NASA Astrophysics Data System (ADS)

    Üpping, J.; Bielawny, A.; Lee, S.; Knez, M.; Carius, R.; Wehrspohn, R. B.

    2009-08-01

    The progress of 3D photonic intermediate reflectors for micromorph silicon tandem cells towards a first prototype cell is presented. Intermediate reflectors enhance the absorption of spectrally-selected light in the top cell and decrease the current mismatch between both junctions. A numerical method to predict filter properties for optimal current matching is presented. Our device is an inverted opal structure made of ZnO and fabricated using self-organized nanoparticles and atomic layer deposition for conformal coating. In particular, the influence of ZnO-doping and replicated cracks during drying of the opal is discussed with respect to conductivity and optical properties. A first prototype is compared to a state-of-the-art reference cell.

  10. Enhancing Children

    ERIC Educational Resources Information Center

    Cigman, Ruth

    2008-01-01

    The "enhancement agenda" in educational policy is based on the idea that "something affective", which supports and improves learning, can be a) measured and b) enhanced. This idea is explored, and it is argued that the identity of the "something" that the enhancement agenda seeks to enhance is fatally obscure, as is the idea of measurable…

  11. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Brown, Edward J. (Clifton Park, NY); Baldasaro, Paul F. (Clifton Park, NY); Dziendziel, Randolph J. (Middlegrove, NY)

    1997-01-01

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength .lambda..sub.IF approximately equal to the bandgap wavelength .lambda..sub.g of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5.lambda..sub.IF to .lambda..sub.IF and reflect from .lambda..sub.IF to about 2.lambda..sub.IF ; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5.lambda..sub.IF.

  12. Segregated tandem filter for enhanced conversion efficiency in a thermophotovoltaic energy conversion system

    DOEpatents

    Brown, E.J.; Baldasaro, P.F.; Dziendziel, R.J.

    1997-12-23

    A filter system to transmit short wavelength radiation and reflect long wavelength radiation for a thermophotovoltaic energy conversion cell comprises an optically transparent substrate segregation layer with at least one coherent wavelength in optical thickness; a dielectric interference filter deposited on one side of the substrate segregation layer, the interference filter being disposed toward the source of radiation, the interference filter including a plurality of alternating layers of high and low optical index materials adapted to change from transmitting to reflecting at a nominal wavelength {lambda}{sub IF} approximately equal to the bandgap wavelength {lambda}{sub g} of the thermophotovoltaic cell, the interference filter being adapted to transmit incident radiation from about 0.5{lambda}{sub IF} to {lambda}{sub IF} and reflect from {lambda}{sub IF} to about 2{lambda}{sub IF}; and a high mobility plasma filter deposited on the opposite side of the substrate segregation layer, the plasma filter being adapted to start to become reflecting at a wavelength of about 1.5{lambda}{sub IF}. 10 figs.

  13. Topex/Jason combined GPS/DORIS orbit determination in the tandem phase

    NASA Astrophysics Data System (ADS)

    Willis, P.; Haines, B.; Bar-Sever, Y.; Bertiger, W.; Muellerschoen, R.; Kuang, D.; Desai, S.

    2003-04-01

    In December 2001, the Jason-1 satellite was launched to extend the long-term success of the TOPEX/POSEIDON (T/P) oceanographic mission. The goals for the Jason-1 mission represent both a significant challenge and a rare opportunity for precise orbit determination (POD) analysts. Like its predecessor, Jason-1 carries three types of POD systems: a GPS receiver, a DORIS receiver and a laser retro-reflector. In view of the 1-cm goal for radial orbit accuracy, several major improvements have been made to the POD systems: 1) the GPS "BlackJack" TurboRogue Space Receiver (TRSR) tracks up to 12 GPS spacecraft using advanced codeless tracking techniques; 2) a newly developed DORIS receiver can track two ground beacons simultaneously with lower noise. In addition, the satellite itself features more straightforward attitude behavior, and a symmetric shape, simplifying the orbit determination models compared to T/P. On the other hand, the area-to-mass ratio for Jason-1 is larger, implying larger potential surface-force errors. This paper presents Jason-1 POD results obtained at JPL using the GIPSY-OASIS II (GOA) software package. Results from standard tests (orbit overlaps, laser control points) suggest that 1 to 2 cm radial orbit precision is already being achieved using the JPL reduced-dynamic estimation approach. We also report new DORIS POD strategies that make full profit of the additional number of common DORIS observations due to the T/P·Jason-1 tandem mode of orbit as well the additional dual-channel capability of the upgraded JASON receiver (allowing simultaneous tracking of two ground stations). New information on the satellite's time scale is availed through this new estimation strategy. Results show that a significant improvement to DORIS-based orbits could be gained using this strategy. Building on these results, we have extended the GIPSY/OASIS 11 software capability to more fully exploit the combined benefit of both GPS and DORIS measurements from T/P and Jason-1 in their preliminary tandem mode. POD test results are used to demonstrate the accuracy of these orbits and to compare results in different cases: DORIS-alone, and GPS and DORIS together in both single- and multi-satellite modes. On the other, we have demonstrated and explained an anomalous behavior of the on-board oscillator when crossing the South Atlantic Anomaly region. Finally, plans for future software enhancements, processing strategies and modeling improvements are presented.

  14. Optical extinction monitor using cw cavity enhanced detection

    Microsoft Academic Search

    Paul L. Kebabian; Wade A. Robinson; Andrew Freedman

    2007-01-01

    We present details of an apparatus capable of measuring optical extinction (i.e., scattering and\\/or absorption) with high precision and sensitivity. The apparatus employs one variant of cavity enhanced detection, specifically cavity attenuated phase shift spectroscopy, using a near-confocal arrangement of two high reflectivity (R~0.9999) mirrors in tandem with an enclosed cell 26 cm in length, a light emitting diode (LED),

  15. Tandem demodulation lock-in amplifier based on digital signal processor for dual-modulated spectroscopy.

    PubMed

    Qin, Jianhuan; Huang, Zhiming; Ge, Yujian; Hou, Yun; Chu, Junhao

    2009-03-01

    Dual-modulated spectroscopy is one of the most powerful methods in the measurement of modulation spectroscopy. Here we develop a tandem lock-in amplifier (LIA) based on digital signal processor to implement a novel algorithm of tandem demodulation. The theoretical analysis of demodulation algorithm is presented, and the implementation of this tandem LIA is described in detail. Compared to the traditional demodulating way with two LIAs in cascade, this tandem LIA eliminates the extra quantization error of redundant analog-to-digital and digital-to-analog conversions and removes the limitation to the time constant in the commercial LIA, hence lowers the requirement of frequency ratio in dual-modulated spectroscopy. The applications are given as examples in the photoreflectance (PR) measurements of GaAs (100) thin film and GaSb bulk material, respectively, at the different optical energy regions. The experimental results indicate that this tandem is well capable of PR spectra measurement with good PR lineshapes and reasonable signal noise ratio. A brief comparison of GaAs PR results between tandem LIA and two LIAs is made to prove the efficiency and advantages of the tandem LIA. PMID:19334912

  16. Tandem demodulation lock-in amplifier based on digital signal processor for dual-modulated spectroscopy

    NASA Astrophysics Data System (ADS)

    Qin, Jianhuan; Huang, Zhiming; Ge, Yujian; Hou, Yun; Chu, Junhao

    2009-03-01

    Dual-modulated spectroscopy is one of the most powerful methods in the measurement of modulation spectroscopy. Here we develop a tandem lock-in amplifier (LIA) based on digital signal processor to implement a novel algorithm of tandem demodulation. The theoretical analysis of demodulation algorithm is presented, and the implementation of this tandem LIA is described in detail. Compared to the traditional demodulating way with two LIAs in cascade, this tandem LIA eliminates the extra quantization error of redundant analog-to-digital and digital-to-analog conversions and removes the limitation to the time constant in the commercial LIA, hence lowers the requirement of frequency ratio in dual-modulated spectroscopy. The applications are given as examples in the photoreflectance (PR) measurements of GaAs (100) thin film and GaSb bulk material, respectively, at the different optical energy regions. The experimental results indicate that this tandem is well capable of PR spectra measurement with good PR lineshapes and reasonable signal noise ratio. A brief comparison of GaAs PR results between tandem LIA and two LIAs is made to prove the efficiency and advantages of the tandem LIA.

  17. DNA Damage by Ionizing Radiation: Tandem Double Lesions by Charged Particles

    NASA Technical Reports Server (NTRS)

    Huo, Winifred M.; Chaban, Galina M.; Wang, Dunyou; Dateo, Christopher E.

    2005-01-01

    Oxidative damages by ionizing radiation are the source of radiation-induced carcinogenesis, damage to the central nervous system, lowering of the immune response, as well as other radiation-induced damages to human health. Monte Carlo track simulations and kinetic modeling of radiation damages to the DNA employ available molecular and cellular data to simulate the biological effect of high and low LET radiation io the DNA. While the simulations predict single and double strand breaks and base damages, so far all complex lesions are the result of stochastic coincidence from independent processes. Tandem double lesions have not yet been taken into account. Unlike the standard double lesions that are produced by two separate attacks by charged particles or radicals, tandem double lesions are produced by one single attack. The standard double lesions dominate at the high dosage regime. On the other hand, tandem double lesions do not depend on stochastic coincidences and become important at the low dosage regime of particular interest to NASA. Tandem double lesions by hydroxyl radical attack of guanine in isolated DNA have been reported at a dosage of radiation as low as 10 Gy. The formation of two tandem base lesions was found to be linear with the applied doses, a characteristic of tandem lesions. However, tandem double lesions from attack by a charged particle have not been reported.

  18. Targeted Tandem Duplication of a Large Chromosomal Segment in Aspergillus oryzae

    PubMed Central

    Sato, Atsushi; Ogawa, Masahiro; Hanya, Yoshiki; Oguma, Tetsuya

    2014-01-01

    We describe here the first successful construction of a targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae. The targeted tandem chromosomal duplication was achieved by using strains that had a 5?-deleted pyrG upstream of the region targeted for tandem chromosomal duplication and a 3?-deleted pyrG downstream of the target region. Consequently, strains bearing a 210-kb targeted tandem chromosomal duplication near the centromeric region of chromosome 8 and strains bearing a targeted tandem chromosomal duplication of a 700-kb region of chromosome 2 were successfully constructed. The strains bearing the tandem chromosomal duplication were efficiently obtained from the regenerated protoplast of the parental strains. However, the generation of the chromosomal duplication did not depend on the introduction of double-stranded breaks (DSBs) by I-SceI. The chromosomal duplications of these strains were stably maintained after five generations of culture under nonselective conditions. The strains bearing the tandem chromosomal duplication in the 700-kb region of chromosome 2 showed highly increased protease activity in solid-state culture, indicating that the duplication of large chromosomal segments could be a useful new breeding technology and gene analysis method. PMID:24837372

  19. Transcription enhancer factor-1 (TEF-1) DNA binding sites can specifically enhance gene expression at the beginning of mouse development.

    PubMed Central

    Mélin, F; Miranda, M; Montreau, N; DePamphilis, M L; Blangy, D

    1993-01-01

    In an effort to identify transcriptional elements that are recognized at different stages of early mouse development, polyomavirus (PyV) enhancer mutations were selected for their ability to support PyV transcription and replication in various mouse undifferentiated embryonal carcinoma (EC) and embryonic stem (ES) cell lines. Several of these enhancer mutations were then isolated, sequenced and tested for their ability to stimulate the PyV early gene promoter in plasmid DNA that was either transfected into EC, ES and fibroblast cell lines, or injected into the nuclei of mouse 1-cell and 2-cell embryos. EC, ES and fibroblast cell lines showed clear preferences for different enhancer configurations, and cleavage-stage embryos (2- to 8-cell stage) strongly preferred the same enhancer configuration favored by ES cells. This 'embryo responsive' (ER) enhancer configuration was characterized by a tandem duplication of the region containing a single point mutation that created a DNA binding site for Transcription Enhancer Factor-1 (TEF-1). ER enhancers stimulated the PyV promoter up to 350-fold in embryos, and were up to 74-fold more active than the wild-type PyV enhancer. Most of the activity from PyER enhancers could be duplicated in 2-cell embryos by synthesizing only the tandemly repeated sequence. Comparison of these synthetic enhancers with ER enhancers confirmed that TEF-1 DNA binding sites were highly preferred in ES cells and cleavage-stage embryos, and suggested that ER enhancer activity resulted primarily from cooperative interaction between either two closely spaced TEF-1 DNA binding sites or two TEF-1 DNA binding sites separated by a third, as yet unidentified, transcription factor binding site. These results provide a prototype of a mammalian embryo responsive enhancer, and suggest that TEF-1 plays an important role in activation of gene expression at the beginning of mammalian development. Images PMID:8223475

  20. BLACKBOARD ENHANCEMENT BLACKBOARD ENHANCEMENT SURVEY

    E-print Network

    Rosen, Jay

    · BLACKBOARD ENHANCEMENT · BLACKBOARD ENHANCEMENT SURVEY · UPGRADE TO LIBRARY SYSTEM · STUDIOABROAD INITIATIVE · MICROSOFT IT ACADEMY TECHNOLOGY TODAY Blackboard Enhancement Blackboard underwent a significant enhancement at the end of December with the upgrade of the CUNY Blackboard environment from version 9

  1. Enhancing practice Quality Enhancement Themes

    E-print Network

    Azzopardi, Leif

    Enhancing practice Quality Enhancement Themes: The First Year Experience Transforming assessment and feedback: enhancing integration and empowerment in the first year #12;© The Quality Assurance Agency for Higher Education 2009 ISBN 978 1 84482 901 9 All Enhancement Themes publications are also available

  2. Structural Characterization of Carbohydrates by Fourier Transform Tandem Mass Spectrometry

    PubMed Central

    Zhou, Wen; Håkansson, Kristina

    2012-01-01

    Fourier transform tandem mass spectrometry (MS/MS) provides high mass accuracy, high sensitivity, and analytical versatility and has therefore emerged as an indispensable tool for structural elucidation of biomolecules. Glycosylation is one of the most common posttranslational modifications, occurring in ~50% of proteins. However, due to the structural diversity of carbohydrates, arising from non-template driven biosynthesis, achievement of detailed structural insight is highly challenging. This review briefly discusses carbohydrate sample preparation and ionization methods, and highlights recent developments in alternative high-resolution MS/MS strategies, including infrared multiphoton dissociation (IRMPD), electron capture dissociation (ECD), and electron detachment dissociation (EDD), for carbohydrates with a focus on glycans and proteoglycans from mammalian glycoproteins. PMID:22389641

  3. A tandem mass spectrometric method for singlet oxygen measurement.

    PubMed

    Karonen, Maarit; Mattila, Heta; Huang, Ping; Mamedov, Fikret; Styring, Stenbjörn; Tyystjärvi, Esa

    2014-01-01

    Singlet oxygen, a harmful reactive oxygen species, can be quantified with the substance 2,2,6,6-tetramethylpiperidine (TEMP) that reacts with singlet oxygen, forming a stable nitroxyl radical (TEMPO). TEMPO has earlier been quantified with electron paramagnetic resonance (EPR) spectroscopy. In this study, we designed an ultra-high-performance liquid chromatographic-tandem mass spectrometric (UHPLC-ESI-MS/MS) quantification method for TEMPO and showed that the method based on multiple reaction monitoring (MRM) can be used for the measurements of singlet oxygen from both nonbiological and biological samples. Results obtained with both UHPLC-ESI-MS/MS and EPR methods suggest that plant thylakoid membranes produce 3.7 × 10(-7) molecules of singlet oxygen per chlorophyll molecule in a second when illuminated with the photosynthetic photon flux density of 2000 ?mol m(-2 ) s(-1). PMID:24849296

  4. Structural Basis of Actin Filament Nucleation by Tandem W Domains

    PubMed Central

    Chen, Xiaorui; Ni, Fengyun; Tian, Xia; Kondrashkina, Elena; Wang, Qinghua; Ma, Jianpeng

    2013-01-01

    SUMMARY Spontaneous nucleation of actin is very inefficient in cells. To overcome this barrier, cells have evolved a set of actin filament nucleators to promote rapid nucleation and polymerization in response to specific stimuli. However, the molecular mechanism of actin nucleation remains poorly understood. This is hindered largely by the fact that actin nucleus, once formed, rapidly polymerizes into filament, thus making it impossible to capture stable multisubunit actin nucleus. Here, we report an effective double-mutant strategy to stabilize actin nucleus by preventing further polymerization. Employing this strategy, we solved the crystal structure of AMPPNP-actin in complex with the first two tandem W domains of Cordon-bleu (Cobl), a potent actin filament nucleator. Further sequence comparison and functional studies suggest that the nucleation mechanism of Cobl is probably shared by the p53 cofactor JMY, but not Spire. Moreover, the double-mutant strategy opens the way for atomic mechanistic study of actin nucleation and polymerization. PMID:23727244

  5. Sequencing of Oligourea Foldamers by Tandem Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bathany, Katell; Owens, Neil W.; Guichard, Gilles; Schmitter, Jean-Marie

    2013-03-01

    This study is focused on sequence analysis of peptidomimetic helical oligoureas by means of tandem mass spectrometry, to build a basis for de novo sequencing for future high-throughput combinatorial library screening of oligourea foldamers. After the evaluation of MS/MS spectra obtained for model compounds with either MALDI or ESI sources, we found that the MALDI-TOF-TOF instrument gave more satisfactory results. MS/MS spectra of oligoureas generated by decay of singly charged precursor ions show major ion series corresponding to fragmentation across both CO-NH and N'H-CO urea bonds. Oligourea backbones fragment to produce a pattern of a, x, b, and y type fragment ions. De novo decoding of spectral information is facilitated by the occurrence of low mass reporter ions, representative of constitutive monomers, in an analogous manner to the use of immonium ions for peptide sequencing.

  6. The overdue promise of short tandem repeat variation for heritability.

    PubMed

    Press, Maximilian O; Carlson, Keisha D; Queitsch, Christine

    2014-11-01

    Short tandem repeat (STR) variation has been proposed as a major explanatory factor in the heritability of complex traits in humans and model organisms. However, we still struggle to incorporate STR variation into genotype-phenotype maps. We review here the promise of STRs in contributing to complex trait heritability and highlight the challenges that STRs pose due to their repetitive nature. We argue that STR variants are more likely than single-nucleotide variants to have epistatic interactions, reiterate the need for targeted assays to genotype STRs accurately, and call for more appropriate statistical methods in detecting STR-phenotype associations. Lastly, we suggest that somatic STR variation within individuals may serve as a read-out of disease susceptibility, and is thus potentially a valuable covariate for future association studies. PMID:25182195

  7. An RF heated tandem mirror plasma propulsion study

    NASA Technical Reports Server (NTRS)

    Yang, T. F.; Yao, X.; Peng, S.; Krueger, W. A.; Chang-Diaz, F. R.

    1989-01-01

    Experimental results on a tandem mirror hybrid plume rocket involving a three-stage system of plasma injection, heating, and subsequent injection through a magnetic nozzle are presented. In the experiments, a plasma is created by breaking down the gas with electron cyclotron resonance heating at 2 kW in the central cell, and the ion species is then heated to high temperatures with ion cyclotron resonance heating at 10 kW in the end cell. A Langmuir probe measured an electron density of 2.5 x 10 to the 16th/cu m and a temperature of 100 eV in the central cell and an ion density of 1.25 x 10 to the 17th/cu m and a temperature of 500 eV in the end cell.

  8. 60Fe measurements with an EN tandem accelerator

    NASA Astrophysics Data System (ADS)

    Gartenmann, P.; Schnabel, C.; Suter, M.; Synal, H.-A.

    1997-03-01

    The long-lived radionuclide 60Fe has been detected at the low energies of an EN tandem accelerator. At an energy of 60 MeV, the suppression of the stable isobar 60Ni is the main problem. Spraying hydrogen gas onto the ion source target and extracting the metal single hydrides the nickel contamination in the beam can be reduced more than 500 fold. In the gas ionization detector another five orders of magnitude of suppression are obtained. The resulting background {60Fe}/{Fe} ratio of about 10-11 has enabled first measurements with the standard samples used earlier at Argonne National Laboratory. The results of the two facilities are in agreement.

  9. A new control system for an old tandem

    SciTech Connect

    Jones, N.L.

    1996-11-01

    In an effort to maintain the most flexible environment for accelerator-based atomic physics research at ORNL EN Tandem facility, a recirculating terminal stripper project has been in development. In the early stages of planning for this upgrade, the necessity for monitoring and control of various parameters in the accelerator terminal was considered. To provide proper flexibility and accuracy, telemetry via computer seemed to be the obvious route. Since the development of a robust system not prone to upset from sparks was necessary, a phased development approach was taken. This involves first converting the accelerator`s ground potential systems, then ion source ({similar_to}100 kV) systems that can be easily accessed by merely running down high voltage supplies, and finally terminal potential systems operating in high pressure gas at potentials over 7 MV. Progress to date, including hardware arrangement and software development, is discussed.

  10. Design and testing of a tandem row pump inducer

    NASA Technical Reports Server (NTRS)

    Etter, R. J.

    1974-01-01

    The design and testing of a tandem row pump inducer having a supercavitating first stage with a 0.60 hub ratio is presented. The second stage tested was a helical impeller with a 0.70 hub ratio. A cubic arc transition was utilized to accomplish the hub change. The first stage had two blades and the free-vortex design approach was empirically modified based on previous experience. The recommended second stage design having four blades and using cambered blade section is presented but the model was not built or tested. The more simple helix was built instead to reduce cost. Data taken included head generation, cavitation observations and unsteady head fluctuations over the 0-100Hz range.

  11. Radical-driven peptide backbone dissociation tandem mass spectrometry.

    PubMed

    Oh, Han Bin; Moon, Bongjin

    2015-01-01

    In recent years, a number of novel tandem mass spectrometry approaches utilizing radical-driven peptide gas-phase fragmentation chemistry have been developed. These approaches show a peptide fragmentation pattern quite different from that of collision-induced dissociation (CID). The peptide fragmentation features of these approaches share some in common with electron capture dissociation (ECD) or electron transfer dissociation (ETD) without the use of sophisticated equipment such as a Fourier-transform mass spectrometer. For example, Siu and coworkers showed that CID of transition metal (ligand)-peptide ternary complexes led to the formation of peptide radical ions through dissociative electron transfer (Chu et al., 2000. J Phys Chem B 104:3393-3397). The subsequent collisional activation of the generated radical ions resulted in a number of characteristic product ions, including a, c, x, z-type fragments and notable side-chain losses. Another example is the free radical initiated peptide sequencing (FRIPS) approach, in which Porter et al. and Beauchamp et al. independently introduced a free radical initiator to the primary amine group of the lysine side chain or N-terminus of peptides (Masterson et al., 2004. J Am Chem Soc 126:720-721; Hodyss et al., 2005 J Am Chem Soc 127: 12436-12437). Photodetachment of gaseous multiply charged peptide anions (Joly et al., 2008. J Am Chem Soc 130:13832-13833) and UV photodissociation of photolabile radical precursors including a C-I bond (Ly & Julian, 2008. J Am Chem Soc 130:351-358; Ly & Julian, 2009. J Am Soc Mass Spectrom 20:1148-1158) also provide another route to generate radical ions. In this review, we provide a brief summary of recent results obtained through the radical-driven peptide backbone dissociation tandem mass spectrometry approach. PMID:24863492

  12. Expansion of tandem repeats and oligomer clustering in coding and noncoding DNA sequences

    NASA Astrophysics Data System (ADS)

    Buldyrev, Sergey V.; Dokholyan, Nikolay V.; Havlin, Shlomo; Stanley, H. Eugene; Stanley, Rachel H. R.

    1999-12-01

    We review recent studies of distribution of dimeric tandem repeats and short oligomer clustering in DNA sequences. We find that distribution of dimeric tandem repeats in coding DNA is exponential, while in noncoding DNA it often has long power-law tails. We explain this phenomenon using mutation models based on random multiplicative processes. We also develop a clustering measure based on percolation theory that quantifies the degree of clustering of short oligomers. We find that mono-, di-, and tetramers cluster more in noncoding DNA than in coding DNA. However trimers have some degree of clustering in coding DNA and noncoding DNA. We relate this phenomena to modes of tandem repeat expansion.

  13. 3.75 MeV electron irradiation of III-V concentrator tandem cells

    SciTech Connect

    Andreev, V.M.; Chosta, O.I.; Khvostikov, V.P.; Paleeva, E.V.; Shvarts, M.Z. [Ioffe Physico-Technical Inst., St. Petersburg (Russian Federation)

    1997-12-31

    3.75 MeV electron irradiation of LPE-grown AlGaAs/GaAs monolithic two-terminal tandem solar cells was studied. In addition, Al{sub 0.35}Ga{sub 0.65}As and GaAs single-junction cells with various junction depths prepared to simulate the top and bottom cells of the tandems were irradiated. The cell degradation was characterized by spectral response and by illuminated current-voltage measurements. The degradation of minority-carrier diffusion length were measured on the AlGaAs and GaAs structures for optimization of the tandem solar cells.

  14. A new family of tandem repetitive early histone genes in the sea urchin Lytechinus pictus: evidence for concerted evolution within tandem arrays.

    PubMed Central

    Holt, C A; Childs, G

    1984-01-01

    We have isolated and characterized a third nonallelic tandemly arrayed histone cluster (LpE) from the sea urchin Lytechinus pictus. Although this tandem array is not intermingled with the other two early histone gene families also found in the L. pictus genome, the order and polarity of the five histone coding sequences in this family are the same as every other well characterized sea urchin early histone gene family. Heteroduplex analysis and restriction endonuclease mapping experiments indicate that the LpE family is more closely related to the B-C than the A-D family of early histone genes. Examination of several individual sperm DNA samples has revealed considerable polymorphism in each of the three tandem repeat families. Within an individual, however, each family is remarkably homogeneous. Thus, our results indicate that rapid fixation of variants acts to homogenize the members of a single tandem array at a considerably faster rate within a family than between families. However, at least some exchange of sequences between families is evident based on the conservation of many restriction endonuclease recognition sites and from analysis of a a cosmid clone in which the A-D and E tandem repeats are found adjacent to one another. These differences in the rate of fixation of variants within and between these families are likely to be responsible for the maintenance of diversity between the different families. Images PMID:6089115

  15. Modulation of RNA Metal Binding by Flanking Bases: 15N NMR Evaluation of GC, Tandem GU, and Tandem GA Sites

    PubMed Central

    Wang, Weimin; Zhao, Jianwei; Han, Qianwei; Wang, Gang; Yang, Gengcheng; Shallop, Anthony J.; Liu, Jane; Gaffney, Barbara L.; Jones, Roger A.

    2009-01-01

    15N NMR chemical shift changes in the presence of Mg(H2O)62+, Zn2+, Cd2+, and Co(NH3)63+ were used to probe the effect of flanking bases on metal binding sites in three different RNA motifs. We found that: for GC pairs, the presence of a flanking purine creates a site for the soft metals Zn2+ and Cd2+ only; a GG·UU motif selectively binds only Co(NH3)63+, while a UG·GU motif binds none of these metals; a 3? guanosine flanking the adenosine of a sheared GA·AG pair creates an unusually strong binding site that precludes binding to the cross-strand stacked guanosines within the tandem pair. PMID:20183593

  16. Low driving voltage simplified tandem organic light-emitting devices by using exciplex-forming hosts

    NASA Astrophysics Data System (ADS)

    Zhou, Dong-Ying; Cui, Lin-Song; Zhang, Ying-Jie; Liao, Liang-Sheng; Aziz, Hany

    2014-10-01

    Tandem organic light-emitting devices (OLEDs), i.e., OLEDs containing multiple electroluminescence (EL) units that are vertically stacked, are attracting significant interest because of their ability to realize high current efficiency and long operational lifetime. However, stacking multiple EL units in tandem OLEDs increases driving voltage and complicates fabrication process relative to their standard single unit counterparts. In this paper, we demonstrate low driving voltage tandem OLEDs via utilizing exciplex-forming hosts in the EL units instead of conventional host materials. The use of exciplex-forming hosts reduces the charge injection barriers and the trapping of charges on guest molecules, resulting in the lower driving voltage. The use of exciplex-forming hosts also allows using fewer layers, hence simpler EL configuration which is beneficial for reducing the fabrication complexity of tandem OLEDs.

  17. Genealogy Reconstruction From Short Tandem Repeat Genotypes in an Amazonian Population

    E-print Network

    Kidd, Kenneth

    Genealogy Reconstruction From Short Tandem Repeat Genotypes in an Amazonian Population FRANCESC-8005 KEY WORDS microsatellites; Surui; parentage ABSTRACT We have reconstructed partial genealogies or half sibs. The genealogies inferred show that instances of polygyny and polyandry (or, alternatively

  18. A One-Pot Tandem Olefin Isomerization/Metathesis-Coupling (ISOMET) Reaction

    E-print Network

    Dobereiner, Graham E.

    A tandem catalytic reaction has been developed as part of a process to discover tungsten-based olefin metathesis catalysts that have a strong preference for terminal olefins over cis or trans internal isomers in olefin ...

  19. Nondestructive Evaluation of Double Bevel T-Joint by Tandem Array Ultrasonic Transducer

    NASA Astrophysics Data System (ADS)

    Shirahata, H.; Miki, C.; Yamaguchi, R.

    2003-03-01

    The double bevel T-joint is one of the most fundamental joints of steel bridges. Double bevel T-joint can be seen at beam-column connection of bridge pier. In the Japanese specifications, the welding should be full penetration. However, weld defect of incomplete penetration could be left in the joint due to the lack of quality control in welding. Fatigue cracks can be propagated from the weld defects. The authors developed a tandem array transducer. The tandem array transducer consists of 10 elements aligned in the same direction. Tandem scanning can be simulated by the transducer. Image reconstruction of incomplete penetration by synthetic aperture focusing technique was carried out. The test results showed sufficient detectability of incomplete penetration by the tandem array transducer. Height of incomplete of penetration could be estimated.

  20. Synfuels from fusion: producing hydrogen with the Tandem Mirror Reactor and thermochemical cycles

    SciTech Connect

    Werner, R.W.; Ribe, F.L.

    1981-01-21

    This volume contains the following sections: (1) the Tandem Mirror fusion driver, (2) the Cauldron blanket module, (3) the flowing microsphere, (4) coupling the reactor to the process, (5) the thermochemical cycles, and (6) chemical reactors and process units. (MOW)

  1. Sequence-specific DNA alkylation by tandem Py-Im polyamide conjugates.

    PubMed

    Taylor, Rhys Dylan; Kawamoto, Yusuke; Hashiya, Kaori; Bando, Toshikazu; Sugiyama, Hiroshi

    2014-09-01

    Tandem N-methylpyrrole-N-methylimidazole (Py-Im) polyamides with good sequence-specific DNA-alkylating activities have been designed and synthesized. Three alkylating tandem Py-Im polyamides with different linkers, which each contained the same moiety for the recognition of a 10?bp DNA sequence, were evaluated for their reactivity and selectivity by DNA alkylation, using high-resolution denaturing gel electrophoresis. All three conjugates displayed high reactivities for the target sequence. In particular, polyamide 1, which contained a ?-alanine linker, displayed the most-selective sequence-specific alkylation towards the target 10?bp DNA sequence. The tandem Py-Im polyamide conjugates displayed greater sequence-specific DNA alkylation than conventional hairpin Py-Im polyamide conjugates (4 and 5). For further research, the design of tandem Py-Im polyamide conjugates could play an important role in targeting specific gene sequences. PMID:24942204

  2. Tandem Isotachophoresis-Zone Electrophoresis via Base-Mediated Destacking for Increased

    E-print Network

    Barron, Annelise E.

    Tandem Isotachophoresis-Zone Electrophoresis via Base-Mediated Destacking for Increased Detection Engineering, Northwestern University, Evanston, Illinois 60208 Electrophoresis in microfluidic devices electrophoresis devices. This capability is provided by the implementation of a particular buffer system

  3. Expansion of stochastic expression repertoire by tandem duplication in mouse Protocadherin-? cluster

    PubMed Central

    Kaneko, Ryosuke; Abe, Manabu; Hirabayashi, Takahiro; Uchimura, Arikuni; Sakimura, Kenji; Yanagawa, Yuchio; Yagi, Takeshi

    2014-01-01

    Tandem duplications are concentrated within the Pcdh cluster throughout vertebrate evolution and as copy number variations (CNVs) in human populations, but the effects of tandem duplication in the Pcdh cluster remain elusive. To investigate the effects of tandem duplication in the Pcdh cluster, here we generated and analyzed a new line of the Pcdh cluster mutant mice. In the mutant allele, a 218-kb region containing the Pcdh-?2 to Pcdh-?c2 variable exons with their promoters was duplicated and the individual duplicated Pcdh isoforms can be disctinguished. The individual duplicated Pcdh-? isoforms showed diverse expression level with stochastic expression manner, even though those have an identical promoter sequence. Interestingly, the 5?-located duplicated Pcdh-?c2, which is constitutively expressed in the wild-type brain, shifted to stochastic expression accompanied by increased DNA methylation. These results demonstrate that tandem duplication in the Pcdh cluster expands the stochastic expression repertoire irrespective of sequence divergence. PMID:25179445

  4. Gold-catalyzed efficient tandem assembly of terminal alkynes and arynes: synthesis of alkynylated biphenyl derivatives.

    PubMed

    Xie, Chunsong; Zhang, Yuhong; Yang, Yuzhu

    2008-10-21

    Gold catalysts have been found to catalyze the tandem assembly of arynes and terminal alkynes efficiently in the presence of CuI under mild reaction conditions to provide useful alkynylated biphenyl derivatives. PMID:18830501

  5. Tandem Oxidative Cyclization with Rhenium Oxide. Total Synthesis of 17,18-bisepi-Goniocin

    E-print Network

    Keinan, Ehud

    Tandem Oxidative Cyclization with Rhenium Oxide. Total Synthesis of 17,18-bisepi-Goniocin Subhash C of a rhenium(VII) reagent to produce a single stereoisomer of a tris-THF product. Surprisingly, however

  6. Theoretical and experimental investigation on tandem Theoretical and experimental investigation on tandem modulator configurations for Frequency Coded Quantum Key Distribution systems

    E-print Network

    J. Mora; A. Ruiz-Alba; W. Amaya; V. Garcia-Munoz; J. Capmany

    2009-11-04

    We have theoretically and experimentally address the possible tandem electro-optical modulator configurations that can be employed to implement Frequency Coded Quantum Key Distribution systems (FC-QKD). A closed and general formulation of the end to end field propagation in a dispersion compensated FC-QKD optical fiber system under the low modulation index regime is presented which accounts for all the possible tandem combinations. The properties and the parameter selection of the modulators to achieve each one are summarized. We also address which protocol (B92, BB84 or either) is feasible to be implemented with each configuration. The results confirm those reported for the configurations previously reported in the literature and, at the same time, show the existence of four novel tandem modulator configurations that can also be employed. We have also provided experimental evidence of the successful operation of the novel configurations that confirm the behavior predicted by the theoretical results.

  7. A new simulation approach and its integration with perturbation analysis in tandem queueing systems

    E-print Network

    Jeong, Ki-Young

    1992-01-01

    : Don T, Phillips (Chair of committee) Alberta Garcia-Diaz (Member) Daten B. Cline (Member) Gary J. H (Head ot Departmen August 1992 ABSTRACT A New Simulation Approach and its Integration with Perturbation Analysis in Tandem Queueing Systems.... (August 1992) Ki- Young Jeong, B. E. (Industrial Engr. ), Korea University, Korea Chair of Advisory Committee: Dr. Don T, Phillips This research presents a new simulation approach (NSA) to a single-server tandem queueing system (TQS) and empirically...

  8. Organic-inorganic hybrid tandem multijunction photovoltaics with extended spectral response

    Microsoft Academic Search

    Taehee Kim; Jun Hong Jeon; Seunghee Han; Doh-Kwon Lee; Honggon Kim; Wonmok Lee; Kyungkon Kim

    2011-01-01

    We demonstrate series-connected hybrid tandem multijunction photovoltaics by combining hydrogenated amorphous silicon (a-Si:H) and polymer-based organic photovoltaics (OPVs). To utilize the wide solar spectrum with cost-effective processes, we employed a solution-processed low band gap OPV subcell onto the a-Si:H subcell. The interfacial contact between the subcells strongly affects the photovoltaic performance of the tandem cells. By using MoO3 as an

  9. Design of Integrated III-Nitride\\/Non-III-Nitride Tandem Photovoltaic Devices

    Microsoft Academic Search

    N. G. Toledo; D.. J. Friedman; R. M. Farrell; E. E. Perl; C. T. Lin; J. E. Bowers; J. S. Speck; U. K. Mishra

    2012-01-01

    The integration of III-nitride and non-III-nitride materials for tandem solar cell applications can improve the efficiency of the photovoltaic device due to the added power contributed by the III-nitride top cell to that of high-efficiency multi-junction non-III-nitride solar cells if the device components are properly designed and optimized. The proposed tandem solar cell is comprised of a III-nitride top cell

  10. High efficiency GaAs\\/CuInSe2 tandem junction solar cells

    Microsoft Academic Search

    N. P. Kim; R. M. Burgess; B. J. Stanbery; R. A. Mickelsen; J. E. Avery

    1988-01-01

    High-efficiency, mechanically stacked tandem junction solar cells based on a double-heterostructure GaAs single-crystal thin-film top cell and a polycrystalline CuInSe2 (CIS) thin-film bottom cell were developed to meet the power needs projected for future spacecraft. The best performance of these tandem cells achieved so far is 21.3 percent AM0, one sun, for a 1-cm2 four-terminal device at 28 deg C.

  11. High efficiency GaAs\\/CuInSe2 tandem junction solar cells

    Microsoft Academic Search

    N. P. Kim; R. M. Burgess; B. J. Stanbery; R. A. Mickelsen; J. E. Avery; R. W. McClelland; B. D. King; M. J. Boden; R. P. Gale

    1988-01-01

    High-efficiency, mechanically stacked tandem junction solar cells based on a double-heterostructure GaAs single-crystal thin-film top cell and a polycrystalline CuInSe2 (CIS) thin-film bottom cell were developed to meet the power needs projected for future spacecraft. The best performance of these tandem cells achieved so far is 21.3% AM0, one sun, for a 1 cm2 four-terminal device at 28 degrees C.

  12. The DCX-domain tandems of doublecortin and doublecortin-like kinase

    Microsoft Academic Search

    Myung Hee Kim; Tomasz Cierpicki; Urszula Derewenda; Daniel Krowarsch; Yuanyi Feng; Yancho Devedjiev; Zbigniew Dauter; Christopher A. Walsh; Jacek Otlewski; John H. Bushweller; Zygmunt S. Derewenda

    2003-01-01

    The doublecortin-like domains (DCX), which typically occur in tandem, are novel microtubule-binding modules. DCX tandems are found in doublecortin, a 360-residue protein expressed in migrating neurons; the doublecortin-like kinase (DCLK); the product of the RP1 gene that is responsible for a form of inherited blindness; and several other proteins. Mutations in the gene encoding doublecortin cause lissencephaly in males and

  13. Triacylglycerols of human milk: Rapid analysis by ammonia negative ion tandem mass spectrometry

    Microsoft Academic Search

    Graeme J. Currie; Heikki Kallio

    1993-01-01

    Human milk traicylglycerols (TAG) were analyzed by ammonia negative ion chemical ionization tandem mass spectrometry. The\\u000a deprotonated molecular ions of triacylglycerols were fractionated at the first mass spectrometry (MS) stage. Twenty-nine of\\u000a the deprotonated TAG ions were further analyzed based on their collisionally activated (CA) spectra. The tandem MS analysis\\u000a covered eleven major acyl carbon number fractions, two of which

  14. The tandem inverter: combining the advantages of voltage-source and current-source inverters

    Microsoft Academic Search

    A. M. Trznadlowski; F. Blaabjerg; J. K. Pedersen; N. Patriciu

    1998-01-01

    A combination of a current-source primary inverter and a voltage-source secondary inverter is proposed as the so-called tandem inverter. The primary inverter operates in the square-wave mode, handling most of the converted power, while its output harmonic currents are compensated by the much smaller secondary inverter. As a result, the tandem inverter, to be used for AC motor control, combines

  15. In situ ion irradiation \\/implantation studies in the HVEM-tandem facility at argonne national laboratory

    Microsoft Academic Search

    C. W. Allen; L. L. Funk; E. A. Ryan; A. Taylor

    1989-01-01

    The HVEM-Tandem User Facility at Argonne National Laboratory interfaces two ion accelerators, a 2 MV tandem accelerator and a 650 kV ion implanter, to a 1.2 MV high-voltage electron microscope. This combination allows experiments involving simultaneous ion irradiation\\/ion implantation, electron irradiation and electron microscopy\\/electron diffraction to be performed. In addition the availability of a variety of microscope sample holders permits

  16. Transparent and tandem solar cells using solution-processed metal nanowire transparent electrodes

    Microsoft Academic Search

    Jung-Yong Lee; Seung-Bum Rim; Whitney Gaynor; Steve T. Connor; Brian E. Hardin; Han Sun Kim; Yi Cui; M. D. McGehee; P. Peumans

    2009-01-01

    Tandem architectures in which multiple energy gaps are combined in a series-connected stack of solar cells are seen as a promising approach to increasing the power conversion efficiency of organic solar cells to commercially relevant values. Even higher efficiencies can be obtained if the photocurrent-matching requirement of such tandem cells is removed by the use of intermediate electrodes in multi-terminal

  17. Structural determination by atmospheric pressure photoionization tandem mass spectrometry of some compounds isolated from the SARA fractions obtained from bitumen.

    PubMed

    Tachon, Nadine; Jahouh, Farid; Delmas, Michel; Banoub, Joseph H

    2011-09-30

    We have identified compounds obtained from the SARA fractions of bitumen by using atmospheric pressure photoionization mass spectrometry and low-energy collision tandem mass spectrometric analyses with a QqToF-MS/MS hybrid instrument. The identified compounds were isolated from the maltene saturated oil and the aromatic fractions of the SARA components of a bitumen. The QqToF instrument had sufficient mass resolution to provide accurate molecular weight information and to enhance the tandem mass spectrometry results. The APPI-QqToF-MS analysis of the separated compounds showed a series of protonated molecules [M + H](+) and molecular ions [M](+?) of the same mass but having different chemical structures, in the maltene saturated oil and the aromatic SARA fractions. These isobaric ions were a molecular ion [M2 ](+?) at m/z 418.2787 and a protonated molecule [M5 + H](+) at m/z 287.1625 in the saturated oil fraction, and molecular ions [M6 ](+?) at m/z 418.1584 and [M7 ](+?) at m/z 287.1285 in the aromatic fraction. The identification of this series of chemical compounds was achieved by performing CID-MS/MS analyses of the molecular ions [M](+?) ([M1 ](+?) at m/z 446. 2980, [M2 ](+?) at m/z 418.2787, [M3 ](+?) at m/z 360.3350 and [M4 ](+?) at m/z 346.2095) in the saturated oil fraction and of the [M5 + H](+) ion at m/z 287.1625 also in the saturated oil fraction. The observed CID-MS/MS fragmentation differences were explained by proposed different breakdown processes of the precursor ions. The presented tandem mass spectrometric study shows the capability of MS/MS experiments to differentiate between different classes of chemical compounds of the SARA components of bitumen and to explain the reasons for the observed mass spectrometric differences. However, greater mass resolution than that provided by the QqToF-MS/MS instrument would be required for the analysis of the asphaltene fraction of bitumen. PMID:23657961

  18. Single and Tandem Stents in Sheep Iliac Arteries: Is There a Difference in Patency?

    SciTech Connect

    Schuermann, Karl; Vorwerk, Dierk; Buecker, Arno; Grosskortenhaus, Stefanie; Guenther, Rolf W. [Department of Diagnostic Radiology, University of Technology, Pauwelsstrasse 30, D-52057 Aachen (Germany)

    1998-09-15

    Purpose: To compare patency and neointima formation of single and tandem arterial stents. Methods: In each of six sheep, two Memotherm nitinol stents (tandem stents) were inserted into the external iliac artery on one side and a single stent into the artery on the opposite side. The size of the iliac lumen was assessed in the proximal, middle, and distal segments of the stents by intravascular ultrasound (IVUS) before, immediately after, and 1 month after implantation when the sheep were killed. Neointimal thickness was determined in the proximal, middle, and distal segments of each stent by light microscopy. Results: All stents remained patent. There was no significant difference in lumen and neointimal thickness between single and tandem stents. Cranial tandem stents showed a significantly wider lumen and smaller neointimal thickness than caudal tandem stents. In the proximal and distal segments, the lumen of the stents was significantly smaller and the neointimal thickness greater than in the middle segment; differences in neointimal thickness were significant only between the proximal and the middle segment. Conclusion: In an experimental setting, tandem stents did not interfere with one another with regard to patency and neointima formation when compared with a single contralateral stent. Neointimal thickening after stent insertion seems to be inversely related to the original arterial diameter.

  19. Peptide Identification by Tandem Mass Spectrometry with Alternate Fragmentation Modes*

    PubMed Central

    Guthals, Adrian; Bandeira, Nuno

    2012-01-01

    The high-throughput nature of proteomics mass spectrometry is enabled by a productive combination of data acquisition protocols and the computational tools used to interpret the resulting spectra. One of the key components in mainstream protocols is the generation of tandem mass (MS/MS) spectra by peptide fragmentation using collision induced dissociation, the approach currently used in the large majority of proteomics experiments to routinely identify hundreds to thousands of proteins from single mass spectrometry runs. Complementary to these, alternative peptide fragmentation methods such as electron capture/transfer dissociation and higher-energy collision dissociation have consistently achieved significant improvements in the identification of certain classes of peptides, proteins, and post-translational modifications. Recognizing these advantages, mass spectrometry instruments now conveniently support fine-tuned methods that automatically alternate between peptide fragmentation modes for either different types of peptides or for acquisition of multiple MS/MS spectra from each peptide. But although these developments have the potential to substantially improve peptide identification, their routine application requires corresponding adjustments to the software tools and procedures used for automated downstream processing. This review discusses the computational implications of alternative and alternate modes of MS/MS peptide fragmentation and addresses some practical aspects of using such protocols for identification of peptides and post-translational modifications. PMID:22595789

  20. Measurements of Unsteady Wake Interference Between Tandem Cylinders

    NASA Technical Reports Server (NTRS)

    Jenkins, Luther N.; Neuhart, Dan H.; McGinley, Cahterine B.; Choudhari, Meelan M.; Khorrami, Mehdi R.

    2006-01-01

    A multi-phase, experimental study in the Basic Aerodynamics Research Tunnel at the NASA Langley Research Center has provided new insight into the unsteady flow interaction around cylinders in tandem arrangement. Phase 1 of the study characterized the mean and unsteady near-field flow around two cylinders of equal diameter using 2-D Particle Image Velocimetry (PIV) and hot-wire anemometry. These measurements were performed at a Reynolds number of 1.66 x 10(exp 5), based on cylinder diameter, and spacing-to-diameter ratios, L/D, of 1.435 and 3.7. The current phase, Phase 2, augments this dataset by characterizing the surface flow on the same configurations using steady and unsteady pressure measurements and surface flow visualization. Transition strips were applied to the front cylinder during both phases to produce a turbulent boundary layer upstream of the flow separation. For these flow conditions and L/D ratios, surface pressures on both the front and rear cylinders show the effects of L/D on flow symmetry, pressure recovery, and the location of flow separation and attachment. Mean streamlines and instantaneous vorticity obtained from the PIV data are used to explain the flow structure in the gap and near-wake regions and its relationship to the unsteady surface pressures. The combination of off-body and surface measurements provides a comprehensive dataset to develop and validate computational techniques for predicting the unsteady flow field at higher Reynolds numbers.

  1. Silicon wafer-based tandem cells: The ultimate photovoltaic solution?

    NASA Astrophysics Data System (ADS)

    Green, Martin A.

    2014-03-01

    Recent large price reductions with wafer-based cells have increased the difficulty of dislodging silicon solar cell technology from its dominant market position. With market leaders expected to be manufacturing modules above 16% efficiency at 0.36/Watt by 2017, even the cost per unit area (60-70/m2) will be difficult for any thin-film photovoltaic technology to significantly undercut. This may make dislodgement likely only by appreciably higher energy conversion efficiency approaches. A silicon wafer-based cell able to capitalize on on-going cost reductions within the mainstream industry, but with an appreciably higher than present efficiency, might therefore provide the ultimate PV solution. With average selling prices of 156 mm quasi-square monocrystalline Si photovoltaic wafers recently approaching 1 (per wafer), wafers now provide clean, low cost templates for overgrowth of thin, wider bandgap high performance cells, nearly doubling silicon's ultimate efficiency potential. The range of possible Si-based tandem approaches is reviewed together with recent results and ultimate prospects.

  2. Modeling tandem AAG8-MEK inhibition in melanoma cells.

    PubMed

    Sun, Bing; Kawahara, Masahiro; Nagamune, Teruyuki

    2014-06-01

    Drug resistance presents a challenge to the treatment of cancer patients, especially for melanomas, most of which are caused by the hyperactivation of MAPK signaling pathway. Innate or acquired drug-resistant relapse calls for the investigation of the resistant mechanisms and new anti-cancer drugs to provide implications for the ultimate goal of curative therapy. Aging-associated gene 8 (AAG8, encoded by the SIGMAR1 gene) is a chaperone protein profoundly elaborated in neurology. However, roles of AAG8 in carcinogenesis remain unclear. Herein, we discover AAG8 antagonists as new MEK inhibitors in melanoma cells and propose a novel drug combination strategy for melanoma therapy by presenting the experimental evidences. We report that specific antagonism of AAG8, efficiently suppresses melanoma cell growth and migration through, at least in part, the inactivation of the RAS-CRAF-MEK signaling pathway. We further demonstrate that melanoma cells that are resistant to AAG8 antagonist harbor refractory CRAF-MEK activity. MEK acts as a central mediator for anti-cancer effects and also for the resistance mechanism, leading to our proposal of tandem AAG8-MEK inhibition in melanoma cells. Combination of AAG8 antagonist and very low concentration of a MEK inhibitor synergistically restricts the growth of drug-resistant cells. These data collectively pinpoint AAG8 as a potential target and delineate a promising drug combination strategy for melanoma therapy. PMID:24634165

  3. ECRH and ICRH in the TMX-U tandem mirror

    SciTech Connect

    Stallard, B.W.; Cummins, W.F.; Molvik, A.W.; Poulsen, P.; Simonen, T.C.; Falabella, S.; Barter, J.D.; Christensen, T.; Dimonte, G.; Romesser, T.E.

    1984-03-15

    In the Tandem Mirror Experiment Upgrade (TMX-U), the formation of a thermal barrier and the potential plugging of ion end loss were achieved at central-cell densities up to 2 x 10/sup 12/ cm/sup -3/. The presence of a thermal barrier was confirmed by direct measurement, and ion axial-confinement times in the range 50 to 100 ms were measured. The ECRH in the end cells (a) initiates plasma startup, (b) generates hot, mirror-confined electrons to form thermal barriers, and (c) creates the plugging potential for central-cell ions. The ECRH system consists of four 200 kW, 28 GHz gyrotrons each feeding power to a separate heating location (two in each end plug). Fundamental heating is used at the potential plug, and second harmonic is used in the thermal barrier. Hot-electron plasmas are produced at total end-cell antenna power levels up to 300 kW. Strong single-pass absorption and net hot-electron heating efficiencies exceeding 40% are observed. Hot-electron parameters achieved are: n/sub eh//n/sub et/ up to 0.8, volume-average beta <..beta..> approx. = 0.15, and T/sub x/ (x-ray tail above 40 keV) in the range 75 to 200 keV.

  4. Sequence analysis of styrenic copolymers by tandem mass spectrometry.

    PubMed

    Yol, Aleer M; Janoski, Jonathan; Quirk, Roderic P; Wesdemiotis, Chrys

    2014-10-01

    Styrene and smaller molar amounts of either m-dimethylsilylstyrene (m-DMSS) or p-dimethylsilylstyrene (p-DMSS) were copolymerized under living anionic polymerization conditions, and the compositions, architectures, and sequences of the resulting copolymers were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and tandem mass spectrometry (MS(2)). MS analysis revealed that linear copolymer chains containing phenyl-Si(CH3)2H pendants were the major product for both DMSS comonomers. In addition, two-armed architectures with phenyl-Si(CH3)2-benzyl branches were detected as minor products. The comonomer sequence in the linear chains was established by MS(2) experiments on lithiated oligomers, based on the DMSS content of fragments generated by backbone C-C bond scissions and with the help of reference MS(2) spectra obtained from a polystyrene homopolymer and polystyrene end-capped with a p-DMSS block. The MS(2) data provided conclusive evidence that copolymerization of styrene/DMSS mixtures leads to chains with a rather random distribution of the silylated comonomer when m-DMSS is used, but to chains with tapered block structures, with the silylated units near the initiator, when p-DMSS is used. Hence, MS(2) fragmentation patterns permit not only differentiation of the sequences generated in the synthesis, but also the determination of specific comonomer locations along the polymer chain. PMID:25181590

  5. Aerodynamics of biplane and tandem wings at low Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Jones, R.; Cleaver, D. J.; Gursul, I.

    2015-06-01

    Experiments were performed to investigate the aerodynamic characteristics of two-wing configurations at a low Reynolds number of 100,000. The wing models were rectangular flat plates with a semi-aspect ratio of two. The stagger between the wings was varied from ? X/c = 0 to 1.5; the gap was varied from ? Y/c = 0 to 2 and ? Y/c = -1.5 to 1.5 for biplane and tandem configurations, respectively, with the decalage angle fixed at 0°. Lift, drag, aerodynamic efficiency and power efficiency ratios show that for small incidence angles, performance compared with the single wing is degraded. However, for single-wing post-stall angles of attack, lift performance improves and stall is delayed significantly for many configurations with nonzero gap, i.e., ? Y/c ? 0. For a fixed angle of attack, there are optimal gaps between the wings for which total lift becomes maximum. Particle image velocimetry measurements show that performance improvement relies heavily on the strength of the inter-wing flow and the interaction of the separated shear layers from the leading edge and trailing edge of the leading wing with the trailing wing. Unsteady forces are found to intensify for certain two-wing configurations. A switching between the stalled and unstalled states for the trailing wing as well as a switching between the merged and distinct wakes is shown to have high flow unsteadiness and large lift fluctuations.

  6. Tandem self-powered photovoltaic-electrochromic window coatings

    SciTech Connect

    Bullock, J.N.; Xu, Y.; Benson, D.K.; Branz, H.M. [National Renewable Energy Lab., Golden, CO (United States)

    1995-12-31

    Wide-gap, transparent amorphous silicon based photovoltaics can be integrated with electrochromic materials to produce a self-powered ``smart`` window coating. Existing electrochromic window designs external electrical connection, which may be economically unfeasible. This problem is solved by the tandem photovoltaic-electrochromic (PV/EC) device, in which a wide-gap amorphous silicon-based alloy (a-SiC:H) photovoltaic device is deposited together with an electrochromic optical transmittance modulator in a monolithic device on a single substrate. In this paper, the authors discuss their proposed monolithic photovoltaic-electrochromic device. They also present studies of transparent, wide-gap (Tauc gap of 1.8 to 2.2 eV) amorphous silicon-carbon thin films and p-i-n devices designed for use in the photovoltaic-electrochromic device. The photovoltaic cells in the PV-EC can operate at low current (<1 mA/cm{sup 2}) because a total injected charge of only 60 {micro}C/cm{sup 2} will darken the EC layer to a visible transmission of 5%, but they will need a high open-circuit voltage (>1.0 V) and high transparency ({approx}70%). They describe the progress toward these design targets.

  7. The evolution and function of protein tandem repeats in plants.

    PubMed

    Schaper, Elke; Anisimova, Maria

    2015-04-01

    Sequence tandem repeats (TRs) are abundant in proteomes across all domains of life. For plants, little is known about their distribution or contribution to protein function. We exhaustively annotated TRs and studied the evolution of TR unit variations for all Ensembl plants. Using phylogenetic patterns of TR units, we detected conserved TRs with unit number and order preserved during evolution, and those TRs that have diverged via recent TR unit gains/losses. We correlated the mode of evolution of TRs to protein function. TR number was strongly correlated with proteome size, with about one-half of all TRs recognized as common protein domains. The majority of TRs have been highly conserved over long evolutionary distances, some since the separation of red algae and green plants c. 1.6 billion yr ago. Conversely, recurrent recent TR unit mutations were rare. Our results suggest that the first TRs by far predate the first plants, and that TR appearance is an ongoing process with similar rates across the plant kingdom. Interestingly, the few detected highly mutable TRs might provide a source of variation for rapid adaptation. In particular, such TRs are enriched in leucine-rich repeats (LRRs) commonly found in R genes, where TR unit gain/loss may facilitate resistance to emerging pathogens. PMID:25420631

  8. Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

    PubMed

    Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

    2011-05-01

    Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers. PMID:21472518

  9. A tandem mirror hybrid plume plasma propulsion facility

    NASA Technical Reports Server (NTRS)

    Chang-Diaz, F. R.; Yang, T. F.; Krueger, W. A.; Peng, S.; Urbahn, J.; Yao, X.; Griffin, D.

    1988-01-01

    A concept in electrodeless plasma propulsion, which is also capable of delivering a variable Isp, is presented. The concept involves a three-stage system of plasma injection, heating, and subsequent ejection through a magnetic nozzle. The nozzle produces the hybrid plume by the coaxial injection of hypersonic neutral gas. The gas layer, thus formed, protects the material walls from the hot plasma and, through increased collisions, helps detach it from the diverging magnetic field. The physics of this concept is evaluated numerically through full spatial and temporal simulations; these explore the operating characteristics of such a device over a wide region of parameter space. An experimental facility to study the plasma dynamics in the hybrid plume was built. The device consists of a tandem mirror operating in an asymmetric mode. A later upgrade of this system will incorporate a cold plasma injector at one end of the machine. Initial experiments involve the full characterization of the operating envelope, as well as extensive measurements of plasma properties at the exhaust. The results of the numerical simulations are described.

  10. Inhibition of the PI3K/AKT-NF-?B pathway with curcumin enhanced radiation-induced apoptosis in human Burkitt's lymphoma.

    PubMed

    Qiao, Qiao; Jiang, Yuanjun; Li, Guang

    2013-01-01

    The phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) signal transduction pathway is commonly misregulated in lymphoma and associated with tumorigenesis and enhanced resistance to radiotherapy. Curcumin has been shown to inhibit the PI3K/AKT signal transduction pathway in several tumor models. In this study, we found that curcumin inhibits constitutive and radiation-induced expression of the PI3K/AKT pathway and its downstream regulator nuclear factor kappaB (NF-?B) in human Burkitt's lymphoma, a high-grade non-Hodgkin's lymphoma (NHL). We further demonstrated that the blockage of radiation-induced activation of the PI3K/AKT pathway and its downstream regulator NF-?B by either curcumin or specific PI3/AKT inhibitors (LY294002 for PI3K or SH-5 for AKT) enhance apoptosis in three human Burkitt's lymphoma cell lines (Namalwa, Ramos, and Raji) that were treated with ionizing radiation. However, no synergic effect on radiation-induced apoptosis was found in the cells co-pretreated with curcumin combined with LY294002 or curcumin combined with SH-5. The results from this study suggest that curcumin might play an important role in radiotherapy of high-grade NHL through inhibition of the PI3K/AKT-dependent NF-?B pathway. PMID:23603894

  11. Multivalent binding of formin-binding protein 21 (FBP21)-tandem-WW domains fosters protein recognition in the pre-spliceosome.

    PubMed

    Klippel, Stefan; Wieczorek, Marek; Schümann, Michael; Krause, Eberhard; Marg, Berenice; Seidel, Thorsten; Meyer, Tim; Knapp, Ernst-Walter; Freund, Christian

    2011-11-01

    The high abundance of repetitive but nonidentical proline-rich sequences in spliceosomal proteins raises the question of how these known interaction motifs recruit their interacting protein domains. Whereas complex formation of these adaptors with individual motifs has been studied in great detail, little is known about the binding mode of domains arranged in tandem repeats and long proline-rich sequences including multiple motifs. Here we studied the interaction of the two adjacent WW domains of spliceosomal protein FBP21 with several ligands of different lengths and composition to elucidate the hallmarks of multivalent binding for this class of recognition domains. First, we show that many of the proteins that define the cellular proteome interacting with FBP21-WW1-WW2 contain multiple proline-rich motifs. Among these is the newly identified binding partner SF3B4. Fluorescence resonance energy transfer (FRET) analysis reveals the tandem-WW domains of FBP21 to interact with splicing factor 3B4 (SF3B4) in nuclear speckles where splicing takes place. Isothermal titration calorimetry and NMR shows that the tandem arrangement of WW domains and the multivalency of the proline-rich ligands both contribute to affinity enhancement. However, ligand exchange remains fast compared with the NMR time scale. Surprisingly, a N-terminal spin label attached to a bivalent ligand induces NMR line broadening of signals corresponding to both WW domains of the FBP21-WW1-WW2 protein. This suggests that distinct orientations of the ligand contribute to a delocalized and semispecific binding mode that should facilitate search processes within the spliceosome. PMID:21917930

  12. Novel Tandem Biotransformation Process for the Biosynthesis of a Novel Compound, 4-(2,3,5,6-Tetramethylpyrazine-1)-4?-Demethylepipodophyllotoxin?

    PubMed Central

    Tang, Ya-Jie; Zhao, Wei; Li, Hong-Mei

    2011-01-01

    According to the structure of podophyllotoxin and its structure-function relationship, a novel tandem biotransformation process was developed for the directional modification of the podophyllotoxin structure to directionally synthesize a novel compound, 4-(2,3,5,6-tetramethylpyrazine-1)-4?-demethylepipodophyllotoxin (4-TMP-DMEP). In this novel tandem biotransformation process, the starting substrate of podophyllotoxin was biotransformed into 4?-demethylepipodophyllotoxin (product 1) with the demethylation of the methoxyl group at the 4? position by Gibberella fujikuroi SH-f13, which was screened out from Shennongjia prime forest humus soil (Hubei, China). 4?-Demethylepipodophyllotoxin (product 1) was then biotransformed into 4?-demethylpodophyllotoxone (product 2) with the oxidation of the hydroxyl group at the 4 position by Alternaria alternata S-f6, which was screened out from the gathered Dysosma versipellis plants in the Wuhan Botanical Garden, Chinese Academy of Sciences. Finally, 4?-demethylpodophyllotoxone (product 2) and ligustrazine were linked with a transamination reaction to synthesize the target product 4-TMP-DMEP (product 3) by Alternaria alternata S-f6. Compared with podophyllotoxin (i.e., a 50% effective concentration [EC50] of 529 ?M), the EC50 of 4-TMP-DMEP against the tumor cell line BGC-823 (i.e., 0.11 ?M) was significantly reduced by 5,199 times. Simultaneously, the EC50 of 4-TMP-DMEP against the normal human proximal tubular epithelial cell line HK-2 (i.e., 0.40 ?M) was 66 times higher than that of podophyllotoxin (i.e., 0.006 ?M). Furthermore, compared with podophyllotoxin (i.e., log P = 0.34), the water solubility of 4-TMP-DMEP (i.e., log P = 0.66) was significantly enhanced by 94%. For the first time, the novel compound 4-TMP-DMEP with superior antitumor activity was directionally synthesized from podophyllotoxin by the novel tandem biotransformation process developed in this work. PMID:21398491

  13. TRStalker: an efficient heuristic for finding fuzzy tandem repeats

    PubMed Central

    Pellegrini, Marco; Renda, M. Elena; Vecchio, Alessio

    2010-01-01

    Motivation: Genomes in higher eukaryotic organisms contain a substantial amount of repeated sequences. Tandem Repeats (TRs) constitute a large class of repetitive sequences that are originated via phenomena such as replication slippage and are characterized by close spatial contiguity. They play an important role in several molecular regulatory mechanisms, and also in several diseases (e.g. in the group of trinucleotide repeat disorders). While for TRs with a low or medium level of divergence the current methods are rather effective, the problem of detecting TRs with higher divergence (fuzzy TRs) is still open. The detection of fuzzy TRs is propaedeutic to enriching our view of their role in regulatory mechanisms and diseases. Fuzzy TRs are also important as tools to shed light on the evolutionary history of the genome, where higher divergence correlates with more remote duplication events. Results: We have developed an algorithm (christened TRStalker) with the aim of detecting efficiently TRs that are hard to detect because of their inherent fuzziness, due to high levels of base substitutions, insertions and deletions. To attain this goal, we developed heuristics to solve a Steiner version of the problem for which the fuzziness is measured with respect to a motif string not necessarily present in the input string. This problem is akin to the ‘generalized median string’ that is known to be an NP-hard problem. Experiments with both synthetic and biological sequences demonstrate that our method performs better than current state of the art for fuzzy TRs and that the fuzzy TRs of the type we detect are indeed present in important biological sequences. Availability: TRStalker will be integrated in the web-based TRs Discovery Service (TReaDS) at bioalgo.iit.cnr.it. Contact: marco.pellegrini@iit.cnr.it Supplementary information: Supplementary data are available at Bioinformatics online. PMID:20529928

  14. Two immunoglobulin tandem proteins with a linking ?-strand reveal unexpected differences in cooperativity and folding pathways.

    PubMed

    Steward, Annette; Chen, Qing; Chapman, Robert I; Borgia, Madeleine B; Rogers, Joseph M; Wojtala, Alexsandra; Wilmanns, Matthias; Clarke, Jane

    2012-02-10

    The study of the folding of single domains, in the context of their multidomain environment, is important because more than 70% of eukaryotic proteins are composed of multiple domains. The structures of the tandem immunoglobulin (Ig) domain pairs A164-A165 and A168-A169, from the A-band of the giant muscle protein titin, reveal that they form tightly associated domain arrangements, connected by a continuous ?-strand. We investigate the thermodynamic and kinetic properties of these tandem domain pairs. While A164-A165 apparently behaves as a single cooperative unit at equilibrium, unfolding without the accumulation of a large population of intermediates, domains in A168-A169 behave independently. Although A169 appears to be stabilized in the tandem protein, we show that this is due to nonspecific stabilization by extension. We elucidate the folding and unfolding pathways of both tandem pairs and show that cooperativity in A164-A165 is a manifestation of the relative refolding and unfolding rate constants of each individual domain. We infer that the differences between the two tandem pairs result from a different pattern of interactions at the domain/domain interface. PMID:22197372

  15. Two Immunoglobulin Tandem Proteins with a Linking ?-Strand Reveal Unexpected Differences in Cooperativity and Folding Pathways

    PubMed Central

    Steward, Annette; Chen, Qing; Chapman, Robert I.; Borgia, Madeleine B.; Rogers, Joseph M.; Wojtala, Alexsandra; Wilmanns, Matthias; Clarke, Jane

    2012-01-01

    The study of the folding of single domains, in the context of their multidomain environment, is important because more than 70% of eukaryotic proteins are composed of multiple domains. The structures of the tandem immunoglobulin (Ig) domain pairs A164–A165 and A168–A169, from the A-band of the giant muscle protein titin, reveal that they form tightly associated domain arrangements, connected by a continuous ?-strand. We investigate the thermodynamic and kinetic properties of these tandem domain pairs. While A164–A165 apparently behaves as a single cooperative unit at equilibrium, unfolding without the accumulation of a large population of intermediates, domains in A168–A169 behave independently. Although A169 appears to be stabilized in the tandem protein, we show that this is due to nonspecific stabilization by extension. We elucidate the folding and unfolding pathways of both tandem pairs and show that cooperativity in A164–A165 is a manifestation of the relative refolding and unfolding rate constants of each individual domain. We infer that the differences between the two tandem pairs result from a different pattern of interactions at the domain/domain interface. PMID:22197372

  16. Organic-inorganic halide perovskite/crystalline silicon four-terminal tandem solar cells.

    PubMed

    Löper, Philipp; Moon, Soo-Jin; de Nicolas, Sílvia Martín; Niesen, Bjoern; Ledinsky, Martin; Nicolay, Sylvain; Bailat, Julien; Yum, Jun-Ho; De Wolf, Stefaan; Ballif, Christophe

    2015-01-21

    Tandem solar cells constructed from a crystalline silicon (c-Si) bottom cell and a low-cost top cell offer a promising way to ensure long-term price reductions of photovoltaic modules. We present a four-terminal tandem solar cell consisting of a methyl ammonium lead triiodide (CH3NH3PbI3) top cell and a c-Si heterojunction bottom cell. The CH3NH3PbI3 top cell exhibits broad-band transparency owing to its design free of metallic components and yields a transmittance of >55% in the near-infrared spectral region. This allows the generation of a short-circuit current density of 13.7 mA cm(-2) in the bottom cell. The four-terminal tandem solar cell yields an efficiency of 13.4% (top cell: 6.2%, bottom cell: 7.2%), which is a gain of 1.8%abs with respect to the reference single-junction CH3NH3PbI3 solar cell with metal back contact. We employ the four-terminal tandem solar cell for a detailed investigation of the optical losses and to derive guidelines for further efficiency improvements. Based on a power loss analysis, we estimate that tandem efficiencies of ?28% are attainable using an optically optimized system based on current technology, whereas a fully optimized, ultimate device with matched current could yield up to 31.6%. PMID:25437303

  17. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-print Network

    Reza Asadpour; Raghu V. K. Chavali; M. Ryyan Khan; Muhammad A. Alam

    2015-05-15

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceeding the bifacial HIT performance at practical albedo reflections. Unlike the traditional design, this bifacial design is relatively insensitive to Perovskite thickness variations, which may translate to simpler manufacture and higher yield.

  18. Ab initio detection of fuzzy amino acid tandem repeats in protein sequences

    PubMed Central

    2012-01-01

    Background Tandem repetitions within protein amino acid sequences often correspond to regular secondary structures and form multi-repeat 3D assemblies of varied size and function. Developing internal repetitions is one of the evolutionary mechanisms that proteins employ to adapt their structure and function under evolutionary pressure. While there is keen interest in understanding such phenomena, detection of repeating structures based only on sequence analysis is considered an arduous task, since structure and function is often preserved even under considerable sequence divergence (fuzzy tandem repeats). Results In this paper we present PTRStalker, a new algorithm for ab-initio detection of fuzzy tandem repeats in protein amino acid sequences. In the reported results we show that by feeding PTRStalker with amino acid sequences from the UniProtKB/Swiss-Prot database we detect novel tandemly repeated structures not captured by other state-of-the-art tools. Experiments with membrane proteins indicate that PTRStalker can detect global symmetries in the primary structure which are then reflected in the tertiary structure. Conclusions PTRStalker is able to detect fuzzy tandem repeating structures in protein sequences, with performance beyond the current state-of-the art. Such a tool may be a valuable support to investigating protein structural properties when tertiary X-ray data is not available. PMID:22536906

  19. Simulation of two dimensional electrophoresis and tandem mass spectrometry for teaching proteomics.

    PubMed

    Fisher, Amanda; Sekera, Emily; Payne, Jill; Craig, Paul

    2012-01-01

    In proteomics, complex mixtures of proteins are separated (usually by chromatography or electrophoresis) and identified by mass spectrometry. We have created 2DE Tandem MS, a computer program designed for use in the biochemistry, proteomics, or bioinformatics classroom. It contains two simulations-2D electrophoresis and tandem mass spectrometry. The two simulations are integrated together and are designed to teach the concept of proteome analysis of prokaryotic and eukaryotic organisms. 2DE-Tandem MS can be used as a freestanding simulation, or in conjunction with a wet lab, to introduce proteomics in the undergraduate classroom. 2DE Tandem MS is a free program available on Sourceforge at https://sourceforge.net/projects/jbf/. It was developed using Java Swing and functions in Mac OSX, Windows, and Linux, ensuring that every student sees a consistent and informative graphical user interface no matter the computer platform they choose. Java must be installed on the host computer to run 2DE Tandem MS. Example classroom exercises are provided in the Supporting Information. PMID:23166029

  20. Detailed balance analysis of area de-coupled double tandem photovoltaic modules

    NASA Astrophysics Data System (ADS)

    Strandberg, Rune

    2015-01-01

    This paper describes how layers of area de-coupled top and bottom cells in photovoltaic tandem modules can increase the efficiency of two-terminal tandem devices. The point of the area de-coupling is to allow the number of top cells to differ from the number of bottom cells. Within each of the layers, the cells can be horizontally series-connected and the layers can then be current- or voltage-matched with each other in a tandem module. Using detailed balance modeling, it is shown that two-terminal tandem modules of this type can achieve the same theoretical efficiency as stacks of independently operated cells, often referred to as four-terminal cells. Optimal ratios of the number of bottom cells to the number of top cells are calculated. Finally, it is shown that modules with a bottom layer consisting of 60 cells with a band gap of 1.11 eV, resembling standard silicon modules, offer sufficient resolution to optimize the number of top cells and achieve high efficiency over a large range of top cell band gaps. This result extends the list of materials that can be used as top cells in two-terminal tandem modules with silicon bottom cells.

  1. Generation of Tandem Direct Duplications by Reversed-Ends Transposition of Maize Ac Elements

    PubMed Central

    Peterson, Thomas

    2013-01-01

    Tandem direct duplications are a common feature of the genomes of eukaryotes ranging from yeast to human, where they comprise a significant fraction of copy number variations. The prevailing model for the formation of tandem direct duplications is non-allelic homologous recombination (NAHR). Here we report the isolation of a series of duplications and reciprocal deletions isolated de novo from a maize allele containing two Class II Ac/Ds transposons. The duplication/deletion structures suggest that they were generated by alternative transposition reactions involving the termini of two nearby transposable elements. The deletion/duplication breakpoint junctions contain 8 bp target site duplications characteristic of Ac/Ds transposition events, confirming their formation directly by an alternative transposition mechanism. Tandem direct duplications and reciprocal deletions were generated at a relatively high frequency (?0.5 to 1%) in the materials examined here in which transposons are positioned nearby each other in appropriate orientation; frequencies would likely be much lower in other genotypes. To test whether this mechanism may have contributed to maize genome evolution, we analyzed sequences flanking Ac/Ds and other hAT family transposons and identified three small tandem direct duplications with the structural features predicted by the alternative transposition mechanism. Together these results show that some class II transposons are capable of directly inducing tandem sequence duplications, and that this activity has contributed to the evolution of the maize genome. PMID:23966872

  2. Matching Patterns of Gene Expression to Mechanical Stiffness at Cell Resolution through Quantitative Tandem Epifluorescence and Nanoindentation1[C][W][OPEN

    PubMed Central

    Milani, Pascale; Mirabet, Vincent; Cellier, Coralie; Rozier, Frédérique; Hamant, Olivier; Das, Pradeep; Boudaoud, Arezki

    2014-01-01

    Cell differentiation has been associated with changes in mechanical stiffness in single-cell systems, yet it is unknown whether this association remains true in a multicellular context, particularly in developing tissues. In order to address such questions, we have developed a methodology, termed quantitative tandem epifluorescence and nanoindentation, wherein we sequentially determine cellular genetic identity with confocal microscopy and mechanical properties with atomic force microscopy. We have applied this approach to examine cellular stiffness at the shoot apices of Arabidopsis (Arabidopsis thaliana) plants carrying a fluorescent reporter for the CLAVATA3 (CLV3) gene, which encodes a secreted glycopeptide involved in the regulation of the centrally located stem cell zone in inflorescence and floral meristems. We found that these CLV3-expressing cells are characterized by an enhanced stiffness. Additionally, by tracking cells in young flowers before and after the onset of GREEN FLUORESCENT PROTEIN expression, we observed that an increase in stiffness coincides with this onset. This work illustrates how quantitative tandem epifluorescence and nanoindentation can reveal the spatial and temporal dynamics of both gene expression and cell mechanics at the shoot apex and, by extension, in the epidermis of any thick tissue. PMID:24924426

  3. Conversion of 3-nitrotyrosine to 3-aminotyrosine residues facilitates mapping of tyrosine nitration in proteins by electrospray ionization-tandem mass spectrometry using electron capture dissociation.

    PubMed

    Guo, Jia; Prokai, Laszlo

    2012-12-01

    Protein tyrosine nitration is associated with oxidative stress and various human diseases. Tandem mass spectrometry has been the method of choice for the identification and localization of this posttranslational modification to understand the underlying mechanisms and functional consequences. Due to the electron predator effect of the nitro group limiting fragmentation of the peptide backbone, electron-based dissociation has not been applicable, however, to nitrotyrosine-containing peptides. A straightforward conversion of the nitrotyrosine to the aminotyrosine residues is introduced to address this limitation. When tested with nitrated ubiquitin and human serum albumin as model proteins in top-down and bottom-up approaches, respectively, this chemical derivatization enhanced backbone fragmentation of the corresponding nitroproteins and nitropeptides by electron capture dissociation (ECD). Increased sequence coverage has been obtained by combining in the bottom-up strategy the conversion of nitrotyrosine to aminotyrosine and introducing, in addition to trypsin, a further digesting enzyme of complementary specificity, when protein nitration was mapped by liquid chromatography-electrospray ionization tandem mass spectrometry using both collision-induced dissociation (CID) and ECD. PMID:23280749

  4. Combination of an AccQ·Tag-ultra performance liquid chromatographic method with tandem mass spectrometry for the analysis of amino acids.

    PubMed

    Salazar, Carolina; Armenta, Jenny M; Cortés, Diego F; Shulaev, Vladimir

    2012-01-01

    Amino acid analysis is a powerful tool in life sciences. Current analytical methods used for the detection and quantitation of low abundance amino acids in complex samples face intrinsic challenges such as insufficient sensitivity, selectivity, and throughput. This chapter describes a protocol that makes use of AccQ?Tag chemical derivatization combined with the exceptional chromatographic resolution of ultra performance liquid chromatography (UPLC), and the sensitivity and selectivity of tandem mass spectrometry (MS/MS). The method has been fully implemented and validated using different tandem quadrupole detectors, and thoroughly tested for a variety of samples such as Plasmodium falciparum, human red blood cells, and Arabidopsis thaliana extracts. Compared to currently available methods for amino acid analysis, the AccQ?Tag UPLC-MS/MS method presented here provides enhanced sensitivity and reproducibility, and offers excellent performance within a short analysis time and a broad dynamic range of analyte concentration. The focus of this chapter is the application of this improved protocol for the compositional amino acid analysis in A. thaliana leaf extracts using the Xevo TQ for mass spectrometric detection. PMID:22125132

  5. Identification of flavonoid glycosides in Rosa chinensis flowers by liquid chromatography-tandem mass spectrometry in combination with ¹³C nuclear magnetic resonance.

    PubMed

    Qing, Lin-Sen; Xue, Ying; Zhang, Jian-Guang; Zhang, Zhi-Feng; Liang, Jian; Jiang, Yan; Liu, Yi-Ming; Liao, Xun

    2012-08-01

    Flowers of Rosa chinensis are widely used in traditional Chinese medicine as well as in food industry. Flavonoid glycosides are believed to be the major components in R. chinensis that are responsible for its antioxidant activities. In this work, a liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for analysis of flavonoid glycosides presented in ethyl acetate extract of dried R. chinensis flowers. Twelve flavonoid glycosides were separated and detected. By comparing the retention times, UV spectra, and tandem MS fragments with those of respective authentic compounds, eight flavonoid glycosides were unequivocally identified. Although the other four were also identified as flavonoid glycosides, the glycosylation positions could not be determined due to lack of authentic compounds. Fortunately, the glycosylation effects were clearly observed in the (13)C NMR spectrum of the extract. The detailed structural information was, therefore, obtained to identify the four flavonoid glycosides as quercetin-3-O-D-glucoside, quercetin-3-O-D-xyloside, kaempferol-3-O-D-xyloside and quercetin-3-O-D-(6?-coumaroyl)-galactoside. These flavonoid glycosides were detected and identified for the first time in this botanic material. This work reports on the first use of (13)C NMR of a mixture to enhance a rapid HPLC-MS/MS analysis. The proposed analytical protocol was validated with a mixture of authentic flavonoid glycosides. PMID:22749452

  6. Tandem structured quantum dot/rod sensitized solar cell based on solvothermal synthesized CdSe quantum dots and rods

    NASA Astrophysics Data System (ADS)

    Golobostanfard, Mohammad Reza; Abdizadeh, Hossein

    2014-06-01

    The quantum dots (QD) and quantum rods (QR) of different sizes, shapes, and crystalline phases are synthesized by modified solvothermal method spontaneously employed stirring system and controlled internal applied pressure. The tandem structure of QDs and QRs as well as tetrapods is formed on hierarchical porous titania photoanode by means of electrophoretic deposition. A tremendous enhancement in efficiency of the cell is obtained in samples synthesized at 220 °C for 24 h due to the formation of tandem structure, utilization of Cu2S/CNT composite cathode, co-sensitization of CdS and CdSe, and beneficial role of QRs in electron lifetime. Smaller size QDs with higher band gaps penetrate deeper through the macro-channels of the hierarchical porous structure, while the QRs and tetrapods with lower band gaps are placed on upper layers. Although the charge injection is improved in smaller QDs, the electron lifetime in QRs is longer mainly due to the higher absorption cross section, proper charge separation, introduction of quasi-one dimensional route for charge transport through QRs, and higher surface area available for regeneration with electrolyte. The cell shows the efficiency of 1.05% with JSC of 4.48 mA cm-2, VOC of 0.45 V, and fill factor of 0.52.

  7. Identification and Characterization of Cell-Specific Enhancer Elements for the Mouse ETF\\/Tead2 Gene

    Microsoft Academic Search

    Yasuyuki Tanoue; Michio Yasunami; Kazuo Suzuki; Hiroaki Ohkubo

    2001-01-01

    We have identified and characterized by transient transfection assays the cell-specific 117-bp enhancer sequence in the first intron of the mouse ETF (Embryonic TEA domain-containing factor)\\/Tead2 gene required for transcriptional activation in ETF\\/Tead2 gene-expressing cells, such as P19 cells. The 117-bp enhancer contains one GC-rich sequence (5?-GGGGCGGGG-3?), termed the GC box, and two tandemly repeated GA-rich sequences (5?-GGGGGAGGGG-3?), termed the

  8. Pulsating Tandem Microbubble for Localized and Directional Single Cell Membrane Poration

    PubMed Central

    Sankin, G.N.; Yuan, F.; Zhong, P.

    2013-01-01

    The interaction of laser-generated tandem microbubble (maximum diameter about 50 ?m) with single (rat mammary carcinoma) cells is investigated in a 25-?m liquid layer. Anti-phase and coupled oscillation of the tandem microbubble leads to the formation of alternating, directional microjets (with max. microstreaming velocity of 10 m/s) and vortices (max. vorticity of 350,000 s?1) in opposite directions. Localized and directional membrane poration (200 nm to 2 ?m in pore size) can be produced by the tandem microbubble in an orientation and proximity dependent manner, which is absence from a single oscillating microbubble of comparable size and at the same stand-off distance. PMID:20868077

  9. Fourier transform two-dimensional fluorescence excitation spectrometer by using tandem Fabry-Pérot interferometer.

    PubMed

    Anzai, Hiroshi; Joshi, Neeraj Kumar; Fuyuki, Masanori; Wada, Akihide

    2015-01-01

    A Fourier transform two-dimensional fluorescence excitation spectrometer (FT-2DFES) was developed based on the multiplex technique using a tandem Fabry-Pérot interferometer (tandem FPI). In addition to the advantage of the multiplex technique, the main advantage of the tandem FPI is applicable to the modulation of transition with a large absorption bandwidth (larger than 100 nm) and is thus applicable to the modulation of the excitation of molecules in the condensed phase. As a demonstration of the effectiveness of FT-2DFES, we succeeded in separately observing the fluorescence excitation peaks from a mixed methanol solution of laser dyes (coumarin 480, rhodamine 6G, DCM (4-dicyanomethylene-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran), and LDS750). Furthermore, the energy transfer from rhodamine 6G to LDS750 was observed. PMID:25638100

  10. Hybrid inorganic-organic tandem solar cells for broad absorption of the solar spectrum.

    PubMed

    Speirs, M J; Groeneveld, B G H M; Protesescu, L; Piliego, C; Kovalenko, M V; Loi, M A

    2014-05-01

    We report the first hybrid tandem solar cell with solution processable active layers using colloidal PbS quantum dots (QDs) as the front subcell in combination with a polymer-fullerene rear subcell. Al/WO3 is introduced as an interlayer, yielding an open circuit voltage (VOC) equal to about 92% of the sum of the VOC of the subcells. The device exhibits a power conversion efficiency of 1.8%. Optical simulations of various tandem configurations show that combining PbS QDs with small-bandgap polymers is a promising strategy to obtain tandem solar cells with a very broad absorption range and a high short circuit current. PMID:24652186

  11. Pt-free tandem molecular photoelectrochemical cells for water splitting driven by visible light.

    PubMed

    Fan, Ke; Li, Fusheng; Wang, Lei; Daniel, Quentin; Gabrielsson, Erik; Sun, Licheng

    2014-12-14

    Photoelectrochemical (PEC) cells using molecular catalysts to split water into hydrogen and oxygen have been investigated intensively during the past years. However, the high-cost of Pt counter electrodes and instability of molecular PEC cells hinder the practical applications. We describe in this article a Pt-free tandem molecular PEC cell, for the first time, employing molecular ruthenium- and cobalt-catalysts with strong dipicolinic acid anchoring groups on the respective photoanode and photocathode for total water splitting. The Pt-free tandem molecular PEC cell showed an effective and steady photocurrent density of ca. 25 ?A cm(-2) for water splitting driven by visible light without external bias. This study indicates that tandem molecular PEC cells can provide great potential to the Pt-free devices for light driven total water splitting. PMID:25341620

  12. Tandem repeats and heteroplasmy in the mitochondrial DNA control region of the loggerhead shrike (Lanius ludovicianus).

    PubMed

    Mundy, N I; Winchell, C S; Woodruff, D S

    1996-01-01

    We report the presence of a 128 bp tandem repeat in the mitochondrial control region of the loggerhead shrike (Aves: Lanius ludovicianus). All individuals examined had either two or three copies of the repeat or were heteroplasmic for two and three copies. This is the first direct demonstration of a tandem repeat associated with heteroplasmy in the control region of a bird. A novel model for repeat duplication, which involves an inverted repeat located adjacent to the tandemly repeated sequence, is presented. Individuals with three repeats are absent from the endangered population of San Clemente loggerhead shrike in southern California, suggesting that the island endemic has a small effective population size and that there is insignificant gene flow from the adjacent mainland. PMID:8742819

  13. Construction and operational experience of the Tandem Mirror Experiment-Upgrade (TMX-U)

    SciTech Connect

    Chargin, A.K.; Calderon, M.O.; Moore, T.L.

    1983-07-01

    The Tandem Mirror Experiment-Upgrade (TMX-U) incorporates two new features at Lawrence Livermore National Laboratory (LLNL) tandem mirror program, thermal barriers in the end plugs and injection of the neutral beams at several oblique angles. The thermal barriers isolate the electrons in the end plugs from those in the central cell, making it possible to heat them independently with microwaves. In addition, this innovation produces a large potential gradient in the end plugs with lower magnetic fields and lower neutral-beam energies than would be possible in a conventional tandem mirror device. The TMX-U is also designed to test neutral-beam-injection angles as an experimental parameter. We use angles other than 90/sup 0/ to produce a plasma with improved microstability.

  14. Architecture, performance, and implementation of the tandem banyan fast packet switch

    NASA Technical Reports Server (NTRS)

    Tobagi, Fouad A.; Chiussi, Fabio M.; Kwok, Timothy

    1991-01-01

    The authors propose a space-division fast packet switch architecture based on banyan interconnection networks, called the tandem banyan switching fabric. It consists of placing banyan networks in tandem, offering multiple paths from each input to each output, thus overcoming in a very simple way the effect of conflicts among packets (to which banyan networks are prone) and achieving output buffering. From a hardware implementation perspective, this architecture is simple in that it consists of several instances of only two VLSI chips, one implementing the banyan network and the other implementing the output buffer function. The basic structure and operation of the tandem banyan switching fabric are described, and its performance is discussed. The authors propose a modification to the basic structure which decreases the hardware complexity of the switch while maintaining its performance. An implementation of the banyan network using a high-performance BiCMOS sea-of-gates on 0.8-micron technology is reported.

  15. Two-terminal monolithic InP-based tandem solar cells with tunneling intercell ohmic connections

    NASA Technical Reports Server (NTRS)

    Shen, C. C.; Chang, P. T.; Emery, K. A.

    1991-01-01

    A monolithic two-terminal InP/InGaAsP tandem solar cell was successfully fabricated. This tandem solar cell consists of a p/n InP homojunction top subcell and a 0.95 eV p/n InGaAsP homojunction bottom subcell. A patterned 0.95 eV n(+)/p(+) InGaAsP tunnel diode was employed as an intercell ohmic connection. The solar cell structure was prepared by two-step liquid phase epitaxial growth. Under one sun, AM1.5 global illumination, the best tandem cell delivered a conversion efficiency of 14.8 pct.

  16. Fourier transform two-dimensional fluorescence excitation spectrometer by using tandem Fabry-Pérot interferometer

    NASA Astrophysics Data System (ADS)

    Anzai, Hiroshi; Joshi, Neeraj Kumar; Fuyuki, Masanori; Wada, Akihide

    2015-01-01

    A Fourier transform two-dimensional fluorescence excitation spectrometer (FT-2DFES) was developed based on the multiplex technique using a tandem Fabry-Pérot interferometer (tandem FPI). In addition to the advantage of the multiplex technique, the main advantage of the tandem FPI is applicable to the modulation of transition with a large absorption bandwidth (larger than 100 nm) and is thus applicable to the modulation of the excitation of molecules in the condensed phase. As a demonstration of the effectiveness of FT-2DFES, we succeeded in separately observing the fluorescence excitation peaks from a mixed methanol solution of laser dyes (coumarin 480, rhodamine 6G, DCM (4-dicyanomethylene-2-methyl-6-(p-(dimethylamino)styryl)-4H-pyran), and LDS750). Furthermore, the energy transfer from rhodamine 6G to LDS750 was observed.

  17. GaAs(1-x)P(x) high efficiency tandem solar cells

    NASA Astrophysics Data System (ADS)

    Nell, Matthias E.; Barnett, Allen M.

    The GaAs(1-x) solar cell on a GaP wafer represents a novel approach for a high efficiency tandem solar cell. These solar cells can be produced on a transparent substrate for a mechanically stacked multijunction tandem solar cell structure. For a tandem solar cell consisting of a GaAs(1-x)P(x) top and a Si bottom solar a theoretical maximum efficiency can be predicted by the spectral p-n junction model of 36.7 percent for AM1.5 direct. For that configuration under AM0 illumination the prediction is 35.8 percent. The design considering losses and higher concentration ratios is described.

  18. Biocatalyst Enhancement

    EPA Science Inventory

    The increasing availability of enzyme collections has assisted attempts by pharmaceutical producers to adopt green chemistry approaches to manufacturing. A joint effort between an enzyme producer and a pharmaceutical manufacturer has been enhanced over the past three years by ena...

  19. Penetration enhancers

    Microsoft Academic Search

    Adrian C Williams; Brian W Barry

    2004-01-01

    One long-standing approach for improving transdermal drug delivery uses penetration enhancers (also called sorption promoters or accelerants) which penetrate into skin to reversibly decrease the barrier resistance. Numerous compounds have been evaluated for penetration enhancing activity, including sulphoxides (such as dimethylsulphoxide, DMSO), Azones (e.g. laurocapram), pyrrolidones (for example 2-pyrrolidone, 2P), alcohols and alkanols (ethanol, or decanol), glycols (for example propylene

  20. Overview of the Applications of Tandem Mass Spectrometry (MS\\/MS) in Food Analysis of Nutritionally Harmful Compounds

    Microsoft Academic Search

    Stamatia I. Kotretsou; Aglaia Koutsodimou

    2006-01-01

    Tandem mass spectrometry (MS\\/MS) has proved to be a useful and a time saving analytical tool, with many applications of direct detection of target molecules in food samples. When coupled with chromatographic techniques, it combines the separation capabilities of chromatography and the power of MS\\/MS as an identification and confirmation method. This article reviews the use of tandem mass spectrometry

  1. Human mucin gene MUC4: organization of its 5'-region and polymorphism of its central tandem repeat array.

    PubMed Central

    Nollet, S; Moniaux, N; Maury, J; Petitprez, D; Degand, P; Laine, A; Porchet, N; Aubert, J P

    1998-01-01

    In a previous study we isolated a partial cDNA with a tandem repeat of 48 bp, which allowed us to map a novel human mucin gene named MUC4 to chromosome 3q29. Here we report the organization and sequence of the 5'-region and its junction with the tandem repeat array of MUC4. Analysis of three overlapping genomic clones allowed us to obtain a partial restriction map of MUC4 and to locate the complete 48 bp tandem repeat domain on a PstI/EcoRI genomic fragment that exhibits a very large variation in number of tandem repeats (7-19 kb). cDNA clonal extension allowed us to obtain the entire 5' coding region of MUC4. Exon 1 consists of a 5' untranslated region and an 82 bp fragment encoding the signal peptide. This latter shows a high degree of similarity to the signal peptide of another apomucin, ASGP-1. Exon 2 is extremely large and contains a unique sequence that is followed by the whole tandem repeat domain. It encodes only one cysteine residue, making MUC4 different from mucin genes belonging to the 11p15.5 family. Moreover, an intron downstream from the tandem repeat array consists mainly of a 15 bp tandem repeat that exhibits a polymorphism in having a variable number of tandem repeats. PMID:9620877

  2. Cavitation experiments with tandem propellers designed for large high speed cargo ship. Interim report October 1981March 1983

    Microsoft Academic Search

    1983-01-01

    As part of a Maritime Administration project in energy conservation, the David Taylor Naval Ship Research and Development Center (DTNSRDC) has been tasked to design and evaluate a set of tandem propellers for a high-speed containership (Model 5218). This report presents the results of open water and cavitation experiments for these design tandem propellers. A conventional single propeller was also

  3. Genetic Diversity of Typha latifolia (Typhaceae) and the Impact of Pollutants Examined with Tandem-Repetitive DNA Probes

    Microsoft Academic Search

    Brian Keane; Stephan Pelikan; Greg P. Toth; M. Kate Smith; Steven H. Rogstad

    1999-01-01

    Genetic diversity at variable-number-tandem-repeat (VNTR) loci was examined in the common cattail, Typha latifolia (Typhaceae), using three synthetic DNA probes composed of tandemly repeated ''core'' sequences (GACA, GATA, and GCAC). The principal objectives of this investigation were to determine whether: (1) the previously reported almost complete lack of polymorphism at allozyme loci in this species was indicative of a reduced

  4. 76 FR 40935 - Vertical Tandem Lifts in Marine Terminals; Extension of the Office of Management and Budget's...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-12

    ...OSHA-2011-0066] Vertical Tandem Lifts in Marine Terminals; Extension of the Office of Management...Vertical Tandem Lifts (VTLs) in Marine Terminals (29 CFR part 1917). The collection...transporting vertically coupled containers in a terminal. DATES: Comments must be...

  5. A POWER SHAFT FOR THE MUNICH MP-TANDEM H. STEFFENS, L. ROHRER and S. J. SKORKA

    E-print Network

    Paris-Sud XI, Université de

    1583 A POWER SHAFT FOR THE MUNICH MP-TANDEM H. STEFFENS, L. ROHRER and S. J. SKORKA power shaft developed for the Munich MP-Tandem is described. The shaft transfers energy at a rate by the Pelletron charging chains. For the energy transfer to the dead sections a rotating power shaft was developed

  6. Microfluidic chip-based assay for post-hematopoietic stem cell transplantation chimerism monitoring using polymorphic tandem repeat markers

    Microsoft Academic Search

    Siti Sarah Daud; Kamariah Ibrahim; Soo Sin Choong; Lelamekala Vengidasan; Lee Ai Chong; Hany Ariffin

    2010-01-01

    Following hematopoietic stem cell transplantation (HSCT), it is important to determine whether engraftment is successful and to track the dynamic changes of the graft. Tandem repeats such as minisatellites and microsatellites are currently the most established markers for chimerism application. We have developed a reliable method to quantitatively evaluate engraftment status in post-allogeneic HSCT patients using variable number of tandem

  7. J Physiol 587.20 (2009) pp 47694783 4769 The response of the tandem pore potassium channel

    E-print Network

    Feng, Jianfeng

    2009-01-01

    J Physiol 587.20 (2009) pp 4769­4783 4769 The response of the tandem pore potassium channel TASK-3 potassium channel TASK-3 is thought to open and shut at its selectivity filter in response to changes Tandem pore potassium channels help set the resting membrane potential of a wide variety of cells

  8. 3.75 MeV electron irradiation of III-V concentrator tandem cells

    Microsoft Academic Search

    V. M. Andreev; O. I. Chosta; V. P. Khvostikov; E. V. Paleeva; M. Z. Shvarts

    1997-01-01

    3.75 MeV electron irradiation of LPE-grown AlGaAs\\/GaAs monolithic two-terminal tandem solar cells was studied. In addition, Al0.35 Ga0.65As and GaAs single-junction cells with various junction depths prepared to simulate the top and bottom cells of the tandems were irradiated. The cell degradation was characterized by spectral response and by illuminated current-voltage measurements. The degradation of minority-carrier diffusion length were measured

  9. Temperature dependent spectral response characteristic of III-V compound tandem cell

    Microsoft Academic Search

    Lei Liu; NuoFu Chen; Yu Wang; YiMing Bai; Min Cui; FuBao Gao

    2009-01-01

    The GaInP\\/GaAs\\/Ge triple-junction tandem cells with a conversion efficiency of 27.1% were fabricated using metalorganic chemical\\u000a vapor deposition (MOCVD) technique. Temperature dependence of the spectral response measurements of the GaInP\\/GaAs\\/Ge tandem\\u000a cell was performed by a quantum efficiency system at temperatures ranging from 25°C to 160°C. The red-shift phenomena of the\\u000a absorption limit for all subcells were observed with increasing

  10. Stripping Target of 2.5 MeV 10 mA Tandem Accelerator

    SciTech Connect

    Davydenko, V.I.; Dranichnikov, A.N.; Ivanov, A.A.; Krainov, G.S.; Krivenko, A.S.; Shirokov, V.V. [Budker Institute of Nuclear Physics, Novosibirsk, 630090 (Russian Federation)

    2005-04-06

    An electrostatic tandem-accelerator with 2.5 MeV 10 mA proton beam is under development at BINP. One of the important accelerator parts is a target that converts the half energy accelerated negative hydrogen ions into the proton beam. In the tandem accelerator an argon stripping target with 1 cm tube diameter and 40 cm tube length will be used. To reduce argon flux from the target to accelerator gaps a gas recirculation by turbomolecular pump installed in high voltage electrode is provided. Processes of plasma production and ultraviolet emission due to target ionization by fast ions and stripped electrons are considered in the report.

  11. Tandem Z-Selective Cross-Metathesis/Dihydroxylation: Synthesis of anti-1,2-Diols.

    PubMed

    Dornan, Peter K; Wickens, Zachary K; Grubbs, Robert H

    2015-06-01

    A stereoselective synthesis of anti-1,2-diols has been developed using a multitasking Ru catalyst in an assisted tandem catalysis protocol. A cyclometalated Ru complex catalyzes first a Z-selective cross-metathesis of two terminal olefins, followed by a stereospecific dihydroxylation. Both steps are catalyzed by Ru, as the Ru complex is converted to a dihydroxylation catalyst upon addition of NaIO4 . A variety of olefins were transformed into valuable, highly functionalized, and stereodefined molecules. Mechanistic experiments were performed to probe the nature of the oxidation step and catalyst inhibition pathways. These experiments point the way to more broadly applicable tandem catalytic transformations. PMID:25914354

  12. Physicochemical/Thermodynamic Framework for the Interpretation of Peptide Tandem Mass Spectra

    SciTech Connect

    Cannon, William R.; Rawlins, Mitchell M.

    2010-04-01

    The interpretation of tandem mass spectra of peptides from collision-induced dissociation is discussed from the perspective of a multinomial data analysis problem and from the perspective of statistical mechanics. Both approaches use the same statistical likelihood function, and it is shown that this statistical likelihood is equivalent to an information theory entropy when scaled appropriately. The likelihood function provides a physically and chemically principled way to incorporate intensity information into the interpretation of tandem mass spectra and enables the use of predictive modeling and simulation to inform the peptide identification process.

  13. A statistical approach to peptide identification from clustered tandem mass spectrometry data

    PubMed Central

    Ryu, Soyoung; Goodlett, David R.; Noble, William S.; Minin, Vladimir N.

    2013-01-01

    Tandem mass spectrometry experiments generate from thousands to millions of spectra. These spectra can be used to identify the presence of proteins in biological samples. In this work, we propose a new method to identify peptides, substrings of proteins, based on clustered tandem mass spectrometry data. In contrast to previously proposed approaches, which identify one representative spectrum for each cluster using traditional database searching algorithms, our method uses all available information to score all the spectra in a cluster against candidate peptides using Bayesian model selection. We illustrate the performance of our method by applying it to seven-standard-protein mixture data. PMID:23828149

  14. Solution-processed high-performance colloidal quantum dot tandem photodetectors on flexible substrates

    SciTech Connect

    Jiang, Zhenyu; You, Guanjun; Wang, Li; Liu, Jie; Xu, Jian, E-mail: jianxu@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Hu, Wenjia [China Tianchen Engineering Corporation, Tianjin 300400 (China); Zhang, Yu [State Key Laboratory on Integrated Optoelectronics and College of Electronic Science and Engineering, Jilin University, Changchun 130012 (China)

    2014-08-28

    We report a high-performance colloidal quantum dot (CQD)-based near-infrared tandem photodetector fabricated on flexible substrates via solution-processed method. The tandem photodetector on poly(ethylene terephthalate) substrates exhibited low dark current and high detectivities over ?8.8?×?10{sup 11} Jones at near infrared range at ?0.5?V bias and over ?10{sup 13} Jones near 0 bias. The critical bend radii of ?8?mm and ?3?mm have been demonstrated for tensile and compressive bending, respectively. The performance of photodetectors remains stable under mechanical stress, making PbSe CQD material a promise candidate for flexible infrared sensing applications.

  15. Organic Dye-Sensitized Tandem Photoelectrochemical Cell for Light Driven Total Water Splitting.

    PubMed

    Li, Fusheng; Fan, Ke; Xu, Bo; Gabrielsson, Erik; Daniel, Quentin; Li, Lin; Sun, Licheng

    2015-07-22

    Light driven water splitting was achieved by a tandem dye-sensitized photoelectrochemical cell with two photoactive electrodes. The photoanode is constituted by an organic dye L0 as photosensitizer and a molecular complex Ru1 as water oxidation catalyst on meso-porous TiO2, while the photocathode is constructed with an organic dye P1 as photoabsorber and a molecular complex Co1 as hydrogen generation catalyst on nanostructured NiO. By combining the photocathode and the photoanode, this tandem DS-PEC cell can split water by visible light under neutral pH conditions without applying any bias. PMID:26132113

  16. Equivalent circuit analysis of radiative coupling in monolithic tandem solar cells

    NASA Astrophysics Data System (ADS)

    Lan, Dongchen; Green, Martin A.

    2015-06-01

    As solar cell efficiency improves towards the Shockley-Queisser limit, so does the radiative efficiency of the cell. For tandem stacks of cells where energy conversion efficiency now exceeds 46%, radiative coupling between the cells is becoming increasingly important to consider in cell design, measurement, and performance prediction. We show how an equivalent circuit model can capture the complex radiative interactions between cells in such tandem stacks, allowing more insight into the impact on cell performance. The circuit's use is demonstrated by deriving results relevant to the critical step of eliminating coupling effects from measured cell spectral responses.

  17. Tandem-pumped 1120-nm actively Q-switched fiber laser

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Hua; Hu, Jin-Meng; Zhang, Shi-Qiang; Chen, Lu-Lu; Fang, Yong; Feng, Yan; Li, Zhi

    2015-02-01

    We report on a tandem-pumped actively Q-switched fiber laser system emitting at 1120 nm. Parasitic oscillation is challenging in Yb-doped Q-switched 1120-nm fiber laser, which is suppressed by pumping with a fiber laser at 1018 nm. At least four times improvement in output peak power is demonstrated in a single laser setup with 1018-nm fiber laser pumping instead of 976-nm laser diode pumping. This is, to the best of our knowledge, the first demonstration of a tandem-pumped Q-switched fiber laser.

  18. Optimization of a-SiGe based triple, tandem and single-junction solar cells

    Microsoft Academic Search

    Xunming Deng

    2005-01-01

    Recent research activities at the University of Toledo (UT) in the fabrication of high-efficiency triple, tandem and single-junction solar cells, all employing high-quality a-SiGe cells, are reviewed in this paper. Incorporating various improvements in device fabrication, the UT group fabricated 1) triple-junction a-Si\\/a-SiGe\\/a-SiGe solar cells with 12.5% initial efficiency and 10.7% stable efficiency, tandem-junction a-Si\\/a-SiGe solar cells with 12.9% initial

  19. Nonlinear optical propagation in a tandem structure comprising nonlinear absorption and scattering materials

    SciTech Connect

    Wang, Kangpeng; Ju, Yongfeng; He, Jin; Zhang, Long, E-mail: jwang@siom.ac.cn, E-mail: lzhang@siom.ac.cn; Wang, Jun, E-mail: jwang@siom.ac.cn, E-mail: lzhang@siom.ac.cn [Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); Chen, Yu [Key Laboratory for Advanced Materials, Department of Chemistry, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237 (China); Blau, Werner J. [Key Laboratory of Materials for High-Power Laser, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physics and the Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College Dublin, Dublin 2 (Ireland)

    2014-01-13

    Laser propagation in a tandem structure comprising carbon nanotubes and phthalocyanines is studied by Z-scan method. Due to the different mechanisms of the two materials, the laser beam can be attenuated with different absorptivities, by changing the sequence of light passing through each material. Numerical simulations considering the effect of path length and the change of nonlinear coefficient within each material are conducted for understanding the distribution of laser intensity in the tandem system and hence, fitting of the asymmetric Z-scan curves. The results are helpful for the design of nonlinear optical devices comprising multiple nonlinear materials and mechanisms.

  20. Analysis of isoaspartate in peptides by electrospray tandem mass spectrometry.

    PubMed Central

    Lehmann, W. D.; Schlosser, A.; Erben, G.; Pipkorn, R.; Bossemeyer, D.; Kinzel, V.

    2000-01-01

    In view of the significance of Asn deamidation and Asp isomerization to isoAsp at certain sites for protein aging and turnover, it was desirable to challenge the extreme analytical power of electrospray tandem mass spectrometry (ESI-MS/MS) for the possibility of a site-specific detection of this posttranslational modification. For this purpose, synthetic L-Asp/L-isoAsp containing oligopeptide pairs were investigated by ESI-MS/MS and low-energy collision-induced dissociation (CID). Replacement of L-Asp by L-isoAsp resulted in the same kind of shifts for all 15 peptide pairs investigated: (1) the b/y intensity ratio of complementary b and y ions generated by cleavage of the (L-Asp/L-isoAsp)-X bond and of the X-(L-Asp/L-isoAsp) bond was decreased, and (2) the Asp immonium ion abundance at m/z 88 was also decreased. It is proposed that the isoAsp structure hampers the accepted mechanism of b-ion formation on both its N- and C-terminal side. The b/y ion intensity ratio and the relative immonium ion intensity vary considerably, depending on the peptide sequence, but the corresponding values are reproducible when recorded on the same instrument under identical instrumental settings. Thus, once the reference product ion spectra have been documented for a pair of synthetic peptides containing either L-Asp or L-isoAsp, these identify one or the other form. Characterization and relative quantification of L-Asp/L-isoAsp peptide mixtures are also possible as demonstrated for two sequences for which isoAsp formation has been described, namely myrG-D/isoD-AAAAK (deamidated peptide 1-7 of protein kinase A catalytic subunit) and VQ-D/isoD-GLR (deamidated peptide 41-46 of human procollagen alpha 1). Thus, the analytical procedures described may be helpful for the identification of suspected Asn deamidation and Asp isomerization sites in proteolytic digests of proteins. PMID:11152137

  1. Aeroacoustic Simulations of Tandem Cylinders with Subcritical Spacing

    NASA Technical Reports Server (NTRS)

    Lockard, David P.; Choudhari, Meelan M.; Khorrami, Mehdi R.; Neuhart, Dan H.; Hutcheson, Florence V.; Brooks, Thomas F.; Stead, Daniel J.

    2008-01-01

    Tandem cylinders are being studied because they model a variety of component level interactions of landing gear. The present effort is directed at the case of two identical cylinders with their centroids separated in the streamwise direction by 1.435 diameters. Experiments in the Basic Aerodynamic Research Tunnel and Quiet Flow Facility at NASA Langley Research Center have provided an extensive experimental database of the nearfield flow and radiated noise. The measurements were conducted at a Mach number of 0.1285 and Reynolds number of 1.66x10(exp 5) based on the cylinder diameter. A trip was used on the upstream cylinder to insure a fully turbulent flow separation and, hence, to simulate a major aspect of high Reynolds number flow. The parallel computational effort uses the three-dimensional Navier-Stokes solver CFL3D with a hybrid, zonal turbulence model that turns off the turbulence production term everywhere except in a narrow ring surrounding solid surfaces. The experiments exhibited an asymmetry in the surface pressure that was persistent despite attempts to eliminate it through small changes in the configuration. To model the asymmetry, the simulations were run with the cylinder configuration at a nonzero but small angle of attack. The computed results and experiments are in general agreement that vortex shedding for the spacing studied herein is weak relative to that observed at supercritical spacings. Although the shedding was subdued in the simulations, it was still more prominent than in the experiments. Overall, the simulation comparisons with measured near-field data and the radiated acoustics are reasonable, especially if one is concerned with capturing the trends relative to larger cylinder spacings. However, the flow details of the 1.435 diameter spacing have not been captured in full even though very fine grid computations have been performed. Some of the discrepancy may be associated with the simulation s inexact representation of the experimental configuration, but numerical and flow modeling errors are also likely contributors to the observed differences.

  2. Voltage-matched, two-terminal, GaAs (AlGaAs)/CuInSe2 tandem solar cells

    NASA Astrophysics Data System (ADS)

    Kim, N. P.; Stewart, J. M.; Stanbery, B. J.; Mickelsen, R. A.; Devaney, W. E.; Chen, W. S.; Burgess, R. M.; McClelland, R. W.; Shastry, S.; Dingle, J.

    Mechanically stacked tandem solar cells based on GaAs thin-film single-crystal top cells and CuInSe2 (CIS) bottom cells were developed to meet the weight and radiation-resistance requirements of advanced spacecraft power systems. Efficiencies over 23 percent were demonstrated with these cells in a four-terminal configuration. In order to use the device as a direct replacement for conventional single-junction cells with existing array designs, a two-terminal, voltage-matched tandem cell with 8 sq cm area is designed and fabricated. Tandem cells with efficiencies over 20 percent are demonstrated with this design. AlGaAs high-bandgap cells are demonstrated with efficiencies of over 17 percent for AlGaAs/CIS tandem cells capable of higher end-of-life efficiency. The performance of the two-terminal tandem cells and the AlGaAs high-bandgap cell are described.

  3. Linguistic Affordances of Korean-English Tandem Learning: A Case Study of Korean-English On-Line Chat Pair Interaction

    ERIC Educational Resources Information Center

    Cheon, Heesok

    2012-01-01

    In an attempt to explore an environment for language learning that tandem learning via real-time chat affords to foreign language learners and how language learners respond to those affordances, this study examined learner interaction in online Korean-English Tandem Learning with focus on how tandem learners engaged in peer assistance and how they…

  4. [Determination of streptomycin and dihydrostreptomycin residues in tomato paste by tandem dual solid phase extraction column-liquid chromatography-tandem mass spectrometry].

    PubMed

    Gong, Zhiguo; Su, Min; Ji, Xincheng; Li, Shiyu; Wan, Yuping

    2012-01-01

    The method was specifically developed for the simultaneous determination of streptomycin and dihydrostreptomycin residues in tomato paste by tandem dual solid phase extraction (SPE) column cleanup-liquid chromatography-tandem mass spectrometry. The residues were extracted from the samples with phosphate buffer solution (pH 4). The cleanup was performed by the way of dispersive solid phase extraction and tandem dual solid phase extraction column. The polar chromatographic column was used to complete the separation of the analytes under gradient elution and the analytes were detected in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI +). The external standard calibration curves were used for the quantification. The linear ranges were from 0.01 to 0.2 mg/L with a good linear relationship (r > 0.999) for streptomycin and dihydrostreptomycin. The limit of quantification (LOQs) was 0.02 mg/kg for the both analytes. The recovery range was from 71% to 101% with the relative standard deviations (RSDs) between 2.3% and 15%. It was indicated that this method is accurate, easier, more sensitive, and has a better purification effect in the monitoring and analysis. The method is accurate and specific to monitor and analyze of streptomycin and dihydrostreptomycin residues in tomato paste and its products. PMID:22667088

  5. Quantitative determination of nebivolol from human plasma using liquid chromatography-tandem mass spectrometry.

    PubMed

    Nandania, Jatin; Rajput, S J; Contractor, Pritesh; Vasava, Pragnesh; Solanki, Bhavik; Vohra, Mohsin

    2013-04-01

    In the present work, a rapid, sensitive, specific, precise and accurate liquid chromatography-tandem mass spectrometry method for determination of nebivolol in human plasma was developed and validated with a large calibration curve range (50-5000 pg/mL) which can be used for routine drug analysis and bioequivalence studies. Liquid-liquid extraction method was used to extract the analyte from the human plasma. The separation was achieved using Waters symmetry, C18, 4.6 × 150 mm, 5 ?m column with formic acid in water, 0.01%, v/v: Acetonitrile (40:60) as a mobile phase. A flow rate of 0.8 mL/min, no splitting and run time 2.00 min was used for the chromatographic analysis of nebivolol. Sensitivity of this method was found to be 30 pg/mL. The analyte was analyzed by mass spectrometry in the multiple reaction monitoring mode. A Turbo-Ion spray source was interfaced between the HPLC and triple quadrupole mass spectrometer (MDS Sciex API 4000). The precursor-product ion m/z 406.00-151.00 for nebivolol and m/z 410.20-151.00 for nebivolol-D4 were used for quantification of an analyte and its IS. The method was validated in terms of accuracy, precision, selectivity, absolute recovery, freeze-thaw stability, bench-top stability, dry extract stability, short and long term stock solution stability, wet extract stability and re-injection reproducibility. The within- and between-batch accuracy was found to lie within the range of 87.00-100.40% and within- and between-batch precision was obtained within the range 0.33-8.67%. The mean recovery of all three concentration levels for drug was obtained 67.67% where as the mean recovery of IS was 68.74%. The %RSD value at higher concentration and lower concentration in all stability experiments was within 15%. This method is free from ion suppression, ion enhancement and any type of abnormal ionization. PMID:23500355

  6. Quantification of the 5-lipoxygenase inhibitor zileuton in human plasma using high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Pian, Phillip; Labovitz, Edward; Hoffman, Keith; Clavijo, Claudia F; Rzasa Lynn, Rachael; Galinkin, Jeffrey L; Vinks, Alexander A; Malik, Punam; Christians, Uwe

    2013-10-15

    Zileuton is an orally active, selective inhibitor of 5-lipoxygenase, which catalyzes the first step in the conversion of arachadonic acid into leukotrienes. Given the important role of leukotrienes in inflammation and cell signaling, multiple studies have investigated the efficacy of zileuton in the treatment of human disease. Examples of disease targets include asthma, ulcerative colitis, rheumatoid arthritis, and more recently, acne, ischemic/reperfusion injury, inflammatory pain, and sickle cell anemia. Zileuton is currently approved for the prophylaxis and chronic treatment of asthma. We report the development and validation of a sensitive and specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for the quantification of zileuton in human EDTA plasma. The range of reliable response was 3.05-20,000ng/mL in human plasma. The calibration curves had a correlation coefficient of r(2)>0.99. The intra-day precision was 3.4-5.3%. The inter-day precision ranged from 4.5% to 7.3% and inter-day accuracy from 100% to 107%. No matrix interferences, ion suppression/enhancement, or carry-over was observed. The assay met all predefined acceptance criteria and was subsequently employed to measure plasma zileuton concentrations in a clinical trial. PMID:24029553

  7. Monolith immuno-affinity enrichment liquid chromatography tandem mass spectrometry for quantitative protein analysis of recombinant bovine somatotropin in serum.

    PubMed

    Smits, Nathalie G E; Blokland, Marco H; Wubs, Klaas L; Nessen, Merel A; van Ginkel, Leen A; Nielen, Michel W F

    2015-08-01

    The use of recombinant bovine somatotropin (rbST) to enhance milk production is approved in several countries, but it is prohibited in the European Union. According to EU legislation, it is necessary to confirm positive screening results prior to enforcement. Although adequate screening assays are available nowadays, development of liquid chromatography tandem mass spectrometry (LC-MS/MS) confirmatory methods to detect low levels of rbST is still a challenge. Here, we present a novel approach using immuno-affinity enrichment on monolithic micro-columns in combination with state-of-the-art ultra-high pressure LC-MS/MS (UHPLC-MS/MS) detection. The developed approach enables detection and confirmation of rbST in serum at a decision limit (CC?) concentration of 0.8 ng mL(-1). Furthermore, the method is easy to handle, robust and reproducible. We successfully applied the confirmatory method to serum samples from rbST treated cows that were found suspect after immunoassay-based screening. The use of rbST could be confirmed over 1 week after treatment, and the developed method demonstrated the sensitivity needed for effective control. Graphical Abstract Graphical summary of the workflow, for serum preparation, enrichment with monolith microcolumns and LC-MS/MS measurement of rbST. PMID:26077745

  8. Optical design of GaN/InxGa1-xN/cSi tandem solar cells with triangular diffraction grating.

    PubMed

    Lin, Leo Jyun-Hong; Chiou, Yih-Peng

    2015-06-01

    Optical design in enhancing optical absorption of group-III-nitride- and multiple quantum well-based GaN/InxGa1-xN/cSi dual-junction tandem solar cells with triangular diffraction grating is simulated and optimized by using combined two-dimensional rigorous coupled wave analysis and transfer matrix methods. This paper thoroughly examines these phenomena of optical absorption affected by antireflection coatings, multiple thin-film layers and diffraction gratings with the integrated perspectives of semiconductor physics and electromagnetic theory for the first time. An improvement of 58% in absorption compared to the prototype SC is obtained which means more than 80% of incoming light (h? > EgSi) can be harvested in this thin-film (< 4 ?m in total) design. PMID:26072886

  9. Detection of UV-induced activation of NF-kappaB in a recombinant human cell line by means of Enhanced Green Fluorescent Protein (EGFP).

    PubMed

    Hellweg, Christine E; Baumstark-Khan, Christa

    2007-08-01

    The cellular protection reaction known as ultraviolet (UV) response leads to increased transcription of several genes. Parts of this transcriptional response are transmitted via activation of the Nuclear factor kappaB (NF-kappaB). The contribution of different UV radiation qualities to this process is not yet known. In a previous work, a stably transfected human cell line was developed which indicates activation of the NF-kappaB pathway by fluorescence of the reporters Enhanced Green Fluorescent Protein (EGFP) and its destabilized variant (d2EGFP) thereby allowing a fast and reliable monitoring of UV effects on the NF-kappaB pathway. Cells were exposed to a mercury low-pressure lamp or to simulated sunlight of different wavelength ranges and subjected to flow cytometric analysis after different post-irradiation periods. Growth capacity of cells after UV irradiation was quantified using a luminance measurement of crystal violet stained cell layers. In contrast to UVC and UVB, UVA radiation induced d2EGFP expression and NF-kappaB activation in a non-cytotoxic dose range. These results show that NF-kappaB plays a role in the UVA-induced gene activation in a non-cytotoxic dose range in a human epithelial cell line. PMID:17429671

  10. Mechanism of constitutive activation of FLT3 with internal tandem duplication in the juxtamembrane domain

    Microsoft Academic Search

    Hitoshi Kiyoi; Ryuzo Ohno; Ryuzo Ueda; Hidehiko Saito; Tomoki Naoe

    2002-01-01

    Internal tandem duplication (ITD) of the juxtamembrane (JM) domain of FLT3 is the most frequent mutation in human acute myeloid leukemia, and is significantly associated with leukocytosis and a poor prognosis. Previously we reported that FLT3 with ITD (FLT3\\/ITD) formed a homodimer and was autophosphorylated on tyrosine residues, while the mechanism remains unclear. In this study, we elucidated the role

  11. Large-scale analysis of tandem repeat variability in the human genome

    PubMed Central

    Duitama, Jorge; Zablotskaya, Alena; Gemayel, Rita; Jansen, An; Belet, Stefanie; Vermeesch, Joris R.; Verstrepen, Kevin J.; Froyen, Guy

    2014-01-01

    Tandem repeats are short DNA sequences that are repeated head-to-tail with a propensity to be variable. They constitute a significant proportion of the human genome, also occurring within coding and regulatory regions. Variation in these repeats can alter the function and/or expression of genes allowing organisms to swiftly adapt to novel environments. Importantly, some repeat expansions have also been linked to certain neurodegenerative diseases. Therefore, accurate sequencing of tandem repeats could contribute to our understanding of common phenotypic variability and might uncover missing genetic factors in idiopathic clinical conditions. However, despite long-standing evidence for the functional role of repeats, they are largely ignored because of technical limitations in sequencing, mapping and typing. Here, we report on a novel capture technique and data filtering protocol that allowed simultaneous sequencing of thousands of tandem repeats in the human genomes of a three generation family using GS-FLX-plus Titanium technology. Our results demonstrated that up to 7.6% of tandem repeats in this family (4% in coding sequences) differ from the reference sequence, and identified a de novo variation in the family tree. The method opens new routes to look at this underappreciated type of genetic variability, including the identification of novel disease-related repeats. PMID:24682812

  12. -7. Mol. Biol. (1978) 119, 147-166 Tandem Chromosomal Duplications in Salmonella typhimurium

    E-print Network

    California at Davis, University of

    1978-01-01

    -7. Mol. Biol. (1978) 119, 147-166 Tandem Chromosomal Duplications in Salmonella typhimurium University of Utah ASalt Lake City, Utah 84112, U.S'.A. (Received 16 August 1977) Salmonella strains are merodiploid for large regions (up to 25%) of the Salmonella genome. (4) Recipient strains that inherit the His

  13. J. Mol. Biol. (1978) 126, 53-71 Tandem Genetic Duplications in Salmonella typhimurium

    E-print Network

    California at Davis, University of

    1978-01-01

    J. Mol. Biol. (1978) 126, 53-71 Tandem Genetic Duplications in Salmonella typhimurium AND .I. R. ROTH co& and Salmonella typhimurium (Langridge. 1969; Miller $ Roth. 1971; Hill & Combriato of the histidine operon in Salmonella have previously been described. One is based upon the ability of duplica

  14. Characterization of Tandem Repeats and Repetitive Elements in the Genomes of Mycosphaerella graminicola and M. figiensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the genome of Mycosphaerella graminicola, the causal agent of septoria leaf blotch of wheat, a total of 22745 tandem repeat sites at least 15 bp in length were isolated for motifs from two to 250 bases long by the same processing pipeline that we have used to analyze such repeats in plant EST col...

  15. OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng

    E-print Network

    Deng, Xunming

    -chamber PECVD/Sputtering cluster tool used at UT for the fabrication of triple-junction solar cells [19 structure of a-Si/a-SiGe/a-SiGe triple-junction solar cells used at UT. #12;The solar cells fabricatedOPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR CELLS Xunming Deng Department

  16. Sensitive, Preclinical Detection of Prions in Brain by nanospray liquid chromatography/tandem mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    More sensitive detection of prions in brain is important because it would allow early detection of disease in young animals and assure a safer food supply. We quantitated the amount of proteinase K-resistant prion protein (PrP 27-30) by use of nano-scale liquid chromatography coupled to a tandem ma...

  17. Tandem Smart Cards: Enforcing Trust for TLS-Based Network Services

    Microsoft Academic Search

    Pascal Urien; Simon Elrharbi

    2008-01-01

    This paper presents a new concept, called tandem, dedicated to smart cards that control TLS-based applications. The originality of this approach is to introduce a collaborative process between a smart card and its docking host. This technology enables the secure downloading of a huge amount of data, in untrustworthy computers. We present software paradigms and APIs that facilitate the practical

  18. STRUCTURAL CHARACTERIZATION OF SULFONATED AZO DYES USING LIQUID SECONDARY ION MASS SPECTROMETRY/TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    Eight monosulfonated and disulfonated azo dyes were analyzed using liquid secondary ion mass spectrometry/tandem mass spectrometry, in the negative ion mode, under low-energy conditions (110-150 eV). any structurally characteristic fragment ions were obtained, several of which ha...

  19. IDENTIFICATION OF FLAVONE AGLYCONES AND GLYCOSIDES IN SOYBEAN PODS BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS) was used to identify flavone aglycones and glycosides in soybean pods. Tandem mass spectrometry (MS/MS and MS3) and photodiode array detection were also utilized in flavone characterizat...

  20. Monte Carlo particle simulation and finite-element techniques for tandem mirror transport

    SciTech Connect

    Rognlien, T.D.; Cohen, B.I.; Matsuda, Y.; Stewart, J.J. Jr.

    1985-12-01

    A description is given of numerical methods used in the study of axial transport in tandem mirrors owing to Coulomb collisions and rf diffusion. The methods are Monte Carlo particle simulations and direct solution to the Fokker-Planck equations by finite-element expansion. 11 refs.

  1. Deposition pressure effects on material structure and performance of micromorph tandem solar cells

    Microsoft Academic Search

    Paola Delli Veneri; Lucia V. Mercaldo; Carlo Privato

    2008-01-01

    Tandem solar cells represent an elegant way of overcoming the efficiency limits of single-junction solar cells and reducing the light-induced degradation of amorphous silicon films. Stacked structures consisting of an amorphous silicon top cell and a microcrystalline silicon bottom cell allow a good utilization of the solar spectrum due to the band gap values of the two materials. These devices,

  2. Improving the efficiency of thin film tandem solar cells by plasmonic intermediate reflectors

    Microsoft Academic Search

    Stephan Fahr; Carsten Rockstuhl; Falk Lederer

    2010-01-01

    Thin film tandem solar cells made of amorphous and microcrystalline silicon provide renewable energy at the benefit of low material consumption. As a drawback, these materials do not posses the high carrier mobilities of their crystalline counterpart which limits the feasible material thickness. For maintaining the light absorption as high as possible, photon management is required. Here we show that

  3. Simultaneous determination of dihydrocodeine and dihydromorphine in serum by gas chromatography-tandem mass spectrometry

    Microsoft Academic Search

    Ute Hofmann; Martin F. Fromm; Susanne Johnson; Gerd Mikus

    1995-01-01

    A sensitive and specific method was developed for the determination of dihydrocodeine and its metabolite dihydromorphine in human serum using codeine and morphine as internal standards. Measurement is performed with GC-tandem MS after one simple extraction step and derivatization to the pentafluoropropionic esters. Sensitivity of the method is excellent and allows for the reproducible quantification of dihydrocodeine and dihydromorphine with

  4. PROTEIN-PROTEIN INTERACTIONS OF TANDEM AFFINITY PURIFICATION (TAP)-TAGGED PROTEIN KINASES IN RICE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forty-one rice cDNAs encoding protein kinases were fused to the tandem affinity purification (TAP) tag and expressed in transgenic rice plants. The TAP-tagged kinases and interacting proteins were purified from the T1 progeny of the transgenic rice plants and identified by mass spectrometry. Ninet...

  5. Widespread and subtle: alternative splicing at short-distance tandem sites

    E-print Network

    Will, Sebastian

    ], and the regulation of alternative splicing is important for diverse biological processes. For example, the brain-specific species. It results in subtle changes in the transcripts and often in the encoded proteins. Several of these tandem splice events contribute to the repertoire of functionally different proteins, whereas many

  6. Efficient Tandem Polymer Solar Cells Fabricated by All-Solution Processing

    Microsoft Academic Search

    Jin Young Kim; Kwanghee Lee; Nelson E. Coates; Daniel Moses; Thuc-Quyen Nguyen; Mark Dante; Alan J. Heeger

    2007-01-01

    Tandem solar cells, in which two solar cells with different absorption characteristics are linked to use a wider range of the solar spectrum, were fabricated with each layer processed from solution with the use of bulk heterojunction materials comprising semiconducting polymers and fullerene derivatives. A transparent titanium oxide (TiOx) layer separates and connects the front cell and the back cell.

  7. The tandemly repeated sequences of cartilage link protein contain the sites for interaction with hyaluronic acid

    Microsoft Academic Search

    P. F. Goetinck; N. S. Stirpe; P. A. Tsonis; D. Carlone

    1987-01-01

    The ternary complex involving link protein (LP), proteoglycan monomer, and hyaluronic acid (HA) is an important component of the extracellular matrix of cartilage. LP contains tandemly repeated se- quences that were tested for their ability to interact with HA. A solid-phase assay was developed in which LP could specifically bind to immobilized HA. Detec- tion of LP was by means

  8. Photoelectric properties of a-Si/mesoporous ZnO tandem solar cells

    NASA Astrophysics Data System (ADS)

    Wu, Guizhi; Shen, Yue; Cheng, Wanxi; Gu, Feng; Zhang, Jiancheng; Wang, Linjun

    2011-02-01

    Mesoporous nanocrystalline ZnO applied to a-Si/mesoporous tandem solar cell was synthesized through the hydrothermal method. The structures and morphologies were characterized by X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis based on the nitrogen adsorption isotherm. The test results indicated that the samples had an average pore size of 17 nm and the BET specific surface area was approximately 37.5 m2/g. The transparent a-Si film on fluorine-tin-oxide (FTO) coated glass was obtained by chemical treatment and was used to structure a-Si/mesoporous ZnO tandem solar cell. Under AM 1.5 irradiation, the a- Si/mesoporous tandem solar cell had an open circuit voltage (Voc) of 560 mV, a short circuit current (Jsc) of 3.61 mA/cm2 and a conversion efficiency of 0.28%. The conversion efficiency of tandem solar cell was improved obviously than that of the transparent a-Si film, which had lost special solar cell properties in chemical processing.

  9. An in-depth population genetic analysis of forensic short tandem repeat loci in Indonesia

    Microsoft Academic Search

    S. J. Venables; D. McNevin; R. Daniel; S. D. Sarre; R. A. H. van Oorschot; S. J. Walsh

    Allele frequency data and knowledge of the population genetic features of relevant populations are required to substantiate the strength of forensic DNA evidence. It is conceivable that population substructure exists within Indonesia given that it is an archipelago with over 17,000 islands and encompasses numerous distinct ethnic and linguistic groups. However, the population genetic features of forensic short tandem repeat

  10. Passive Oscillations of Two Tandem Flexible Filaments in a Flowing Soap Film

    Microsoft Academic Search

    Lai-Bing Jia; Xie-Zhen Yin

    2008-01-01

    The passive oscillations of flexible filaments in a flowing soap film were investigated to learn the serial interaction between them. When arranged in tandem, the downstream filament flaps at the same frequency as that of the upstream one, but with a larger amplitude, whereas the upstream one is almost unaffected compared to the single filament case. The data analysis shows

  11. Identification and Characterization of Variable-Number Tandem Repeats in the Yersinia pestis Genome

    Microsoft Academic Search

    ALEXANDRA M. KLEVYTSKA; LANCE B. PRICE; JAMES M. SCHUPP; PATRICIA L. WORSHAM; JANE WONG; PAUL KEIM; Fort Detrick

    2001-01-01

    Yersinia pestis, the infamous plague-causing pathogen, appears to have emerged in relatively recent history. Evidence of this fact comes from several studies that document a lack of nucleotide diversity in the Y. pestis ge- nome. In contrast, we report that variable-number tandem repeat (VNTR) sequences are common in the Y. pestis genome and occur frequently in gene coding regions. Larger

  12. Quaternionic periodicity transform: an algebraic solution to the tandem repeat detection problem

    Microsoft Academic Search

    Andrzej K. Brodzik

    2007-01-01

    Motivation: One of the main tasks of DNA sequence analysis is identification of repetitive patterns. DNA symbol repetitions play a key role in a number of applications, including prediction of gene and exon locations, identification of diseases, reconstruction of human evolutionary history and DNA forensics. Results: A new approach towards identification of tandem repeats in DNA sequences is proposed. The

  13. Quantitative phosphoproteome analysis using a dendrimer conjugation chemistry and tandem mass spectrometry

    Microsoft Academic Search

    W Andy Tao; Bernd Wollscheid; Robert O'Brien; Jimmy K Eng; Xiao-jun Li; Bernd Bodenmiller; Julian D Watts; Leroy Hood; Ruedi Aebersold

    2005-01-01

    We present a robust and general method for the identification and relative quantification of phosphorylation sites in complex protein mixtures. It is based on a new chemical derivatization strategy using a dendrimer as a soluble polymer support and tandem mass spectrometry (MS\\/MS). In a single step, phosphorylated peptides are covalently conjugated to a dendrimer in a reaction catalyzed by carbodiimide

  14. Nonlinear dynamics of an archetypal model of ships motions in tandem

    Microsoft Academic Search

    Jessé Rebello de Souza Jr.; Claudio Gomes Fernandes

    2005-01-01

    Large converted tankers operate as floating platforms for the production of oil in off- shore fields whose depth approaches 2000 m. Their dynamics are influenced by wind, currents, and waves, and also by the physical characteristics of mooring lines. In addi- tion to the single-vessel operation mode, a two-ship tandem arrangement is employed during the transfer of cargo (offloading) from

  15. Performance predictions for monolithic, thin-film CdTe/Ge tandem solar cells

    E-print Network

    Pulfrey, David L.

    Performance predictions for monolithic, thin-film CdTe/Ge tandem solar cells D.L. Pulfrey*, J. Dell be attainable. 1. INTRODUCTION Thin film solar cells based on polycrystalline CdTe have been investigated extensively1-3 . While the technologies for deposition and recrystallisation of CdTe, and the formation

  16. Single versus tandem radar sensor target tracking in the adaptive cruise control environment

    Microsoft Academic Search

    Derek Caveney; J. Karl Hedrick

    2002-01-01

    The multiple target tracking performance of a multiple model technique is investigated. The performance when using a single radar sensor is compared to that when a tandem radar set is employed and the technique implemented is a combination of the interactive multiple model algorithm and the probabilistic data association filter. The investigation shows that the inclusion of a second redundant

  17. Development of a tandem repeat-based multilocus typing system distinguishing Babesia bovis geographic isolates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mini and microsatellite sequences have proven to be excellent tools for the differentiation of strains and populations in several protozoan parasites due to their high variability. In the present work we have searched the genome of the tick-transmitted bovine hemoprotozoon Babesia bovis for tandem r...

  18. High explosives vapor detection by atmospheric sampling glow discharge ionization/tandem mass spectrometry

    SciTech Connect

    McLuckey, S.A.; Goeringer, D.E.; Asano, K.G. [Oak Ridge National Lab., TN (United States). Chemical and Analytical Sciences Div.

    1996-02-01

    The combination of atmospheric sampling glow discharge ionization with tandem mass spectrometry for the detection of traces of high explosives is described. Particular emphasis is placed on use of the quadrupole ion trap as the type of tandem mass spectrometer. Atmospheric sampling glow discharge provides a simple, rugged, and efficient means for anion formation while the quadrupole ion trap provides for efficient tandem mass spectrometry. Mass selective ion accumulation and non-specific ion activation methods can be used to overcome deleterious effects arising from ion/ion interactions. Such interactions constitute the major potential technical barrier to the use of the ion trap for real-time monitoring of targeted compounds in uncontrolled and highly variable matrices. Tailored waveforms can be used to effect both mass selective ion accumulation and ion activation. Concatenated tailored waveforms allow for both functions in a single experiment thereby providing the capability for monitoring several targeted species simultaneously. The combination of atmospheric sampling glow discharge ionization with a state-of-the-art analytical quadrupole ion trap is a highly sensitive and specific detector for traces of high explosives. The combination is also small and inexpensive relative to virtually any other form of tandem mass spectrometry. The science and technology underlying the glow discharge/ion trap combination is sufficiently mature to form the basis for an engineering effort to make the detector portable. 85 refs.

  19. Thermal hydraulic study of the ESPRESSO blanket for a Tandem Mirror Reactor

    SciTech Connect

    Raffray, A.R.; Hoffman, M.A.

    1986-02-01

    This paper deals primarily with the thermal-hydraulic design and some critical thermomechanical aspects of the proposed ESPRESSO blanket for the Tandem Mirror Fusion Reactor. This conceptual design was based on the same physics as used in the MARS study.

  20. A Dynamic Programming Approach to De Novo Peptide Sequencing via Tandem Mass Spectrometry

    E-print Network

    Chen, Ting

    are complementary because joining them determines the original peptide sequence. This dissociation process fragmentsA Dynamic Programming Approach to De Novo Peptide Sequencing via Tandem Mass Spectrometry Ting Chen number of molecules of the same peptide sequence into charged molecules of prefix and suffix peptide

  1. AN ACCURATE AND EFFICIENT ALGORITHM FOR PEPTIDE AND PTM IDENTIFICATION BY TANDEM MASS SPECTROMETRY

    E-print Network

    Wong, Limsoon

    of the database, and the process is usually slow. Additionally, they generally do not perform well for peptides automata to search for peptide sequences. For a batch of spectrum data, the process can be very quickAN ACCURATE AND EFFICIENT ALGORITHM FOR PEPTIDE AND PTM IDENTIFICATION BY TANDEM MASS SPECTROMETRY

  2. Photoelectrochemical Behavior of Hierarchically Structured Si/WO3 Core-Shell Tandem Photoanodes

    E-print Network

    Braun, Paul

    Photoelectrochemical Behavior of Hierarchically Structured Si/WO3 Core-Shell Tandem Photoanodes-shell photoanodes exhibited en- hanced near-visible spectral response behavior, due to increased light absorption-oxide photoanodes coupled with Si photocathodes11,12 and composite metal-oxide photocatalysts,13 have mutually

  3. A Comparison of Tandem Walk Performance Between Bed Rest Subjects and Astronauts

    NASA Technical Reports Server (NTRS)

    Miller, Chris; Peters, Brian; Kofman, Igor; Philips, Tiffany; Batson, Crystal; Cerisano, Jody; Fisher, Elizabeth; Mulavara, Ajitkumar; Feiveson, Alan; Reschke, Millard; Bloomberg, Jacob

    2015-01-01

    Astronauts experience a microgravity environment during spaceflight, which results in a central reinterpretation of both vestibular and body axial-loading information by the sensorimotor system. Subjects in bed rest studies lie at 6deg head-down in strict bed rest to simulate the fluid shift and gravity-unloading of the microgravity environment. However, bed rest subjects still sense gravity in the vestibular organs. Therefore, bed rest isolates the axial-unloading component, thus allowing for the direct study of its effects. The Tandem Walk is a standard sensorimotor test of dynamic postural stability. In a previous abstract, we compared performance on a Tandem Walk test between bed rest control subjects, and short- and long-duration astronauts both before and after flight/bed rest using a composite index of performance, called the Tandem Walk Parameter (TWP), that takes into account speed, accuracy, and balance control. This new study extends the previous data set to include bed rest subjects who performed exercise countermeasures. The purpose of this study was to compare performance during the Tandem Walk test between bed rest subjects (with and without exercise), short-duration (Space Shuttle) crewmembers, and long-duration International Space Station (ISS) crewmembers at various time points during their recovery from bed rest or spaceflight.

  4. Multiple-Locus Variable-Number Tandem Repeat Analysis Reveals Genetic Relationships within Bacillus anthracis

    Microsoft Academic Search

    P. Keim; L. B. Price; A. M. Klevytska; K. L. Smith; J. M. Schupp; R. Okinaka; P. J. Jackson; M. E. Hugh-Jones

    2000-01-01

    Bacillus anthracis is one of the most genetically homogeneous pathogens described, making strain discrim- ination particularly difficult. In this paper, we present a novel molecular typing system based on rapidly evolving variable-number tandem repeat (VNTR) loci. Multiple-locus VNTR analysis (MLVA) uses the com- bined power of multiple alleles at several marker loci. In our system, fluorescently labeled PCR primers are

  5. DEVELOPMENT OF THE HIGH-GRADIENT ELECTROSTATIC ACCELERATOR TECHNIQUES IN THE KYUSHU UNIVERSITY TANDEM

    E-print Network

    Paris-Sud XI, Université de

    1315 DEVELOPMENT OF THE HIGH-GRADIENT ELECTROSTATIC ACCELERATOR TECHNIQUES IN THE KYUSHU UNIVERSITY. MITARAI and K. KOBAYASHI Department of Physics, Faculty of Science, Kyushu University, Hakozaki, Fukuoka électrique élevé. Abstract. - At Kyushu university a 10 MV tandem accelerator is just completed and being

  6. STRUCTURAL CHARACTERIZATION OF REACTIVE DYES USING SECONDARY ION MASS SPECTROMETRY/TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    Reactive Blue 19 (RB 19), its reactive form (RB 19-VS) and its hydrolyzed form, (RB 19-OH) were examined using liquid secondary ion mass spectrometry/tandem mass spectrometry (LSIMS/MS/MS) in the negative-ion mode under low-energy collision conditions (240-300 eV). tructurally ch...

  7. In Two Minds? Learner Attitudes to Bilingualism and the Bilingual Tandem Analyser

    ERIC Educational Resources Information Center

    Kapec, Peter; Schwienhorst, Klaus

    2005-01-01

    One of the issues that has been debated in the context of fairly open learning partnerships such as tandem learning has been whether and, if so, how much pedagogical support should be provided. Another issue is how do language learners who have grown accustomed to maximising their learning through comprehensible input and output make the…

  8. Pool boiling heat transfer of tandem tubes provided with the novel microstructures

    Microsoft Academic Search

    Alexander Ustinov; Victor Ustinov; Jovan Mitrovic

    2011-01-01

    The paper presents experimental data on pool boiling heat transfer of tandem tubes, arranged one above the other in the same vertical plane. The outer surface of the tubes is provided with the novel microstructures. The structure elements are micropins created by electrolytic deposition of copper upon the tube, using a specially treated polycarbonate foil. By this technique the pins

  9. A machine learning approach to explore the spectra intensity pattern of peptides using tandem mass

    E-print Network

    Feng, Jianfeng

    - 1 - A machine learning approach to explore the spectra intensity pattern of peptides using tandem-phase fragmentation of peptides is essential for the development of more reliable algorithms for high- throughput in 13878 different MS/MS spectra. The influence of a library of 35 features on peptide fragmentation

  10. Perovskite-Hematite Tandem Cells for Efficient Overall Solar Driven Water Splitting.

    PubMed

    Gurudayal; Sabba, Dharani; Kumar, Mulmudi Hemant; Wong, Lydia Helena; Barber, James; Grätzel, Michael; Mathews, Nripan

    2015-06-10

    Photoelectrochemical water splitting half reactions on semiconducting photoelectrodes have received much attention but efficient overall water splitting driven by a single photoelectrode has remained elusive due to stringent electronic and thermodynamic property requirements. Utilizing a tandem configuration wherein the total photovoltage is generated by complementary optical absorption across different semiconducting electrodes is a possible pathway to unassisted overall light-induced water splitting. Because of the low photovoltages generated by conventional photovoltaic materials (e.g., Si, CIGS), such systems typically consist of triple junction design that increases the complexity due to optoelectrical trade-offs and are also not cost-effective. Here, we show that a single solution processed organic-inorganic halide perovskite (CH3NH3PbI3) solar cell in tandem with a Fe2O3 photoanode can achieve overall unassisted water splitting with a solar-to-hydrogen conversion efficiency of 2.4%. Systematic electro-optical studies were performed to investigate the performance of tandem device. It was found that the overall efficiency was limited by the hematite's photocurrent and onset potential. To understand these limitations, we have estimated the intrinsic solar to chemical conversion efficiency of the doped and undoped Fe2O3 photoanodes. The total photopotential generated by our tandem system (1.87 V) exceeds both the thermodynamic and kinetic requirements (1.6 V), resulting in overall water splitting without the assistance of an electrical bias. PMID:25942281

  11. Comparative Evaluation of Tandem MS Search Algorithms Using a Target-Decoy Search Strategy

    Microsoft Academic Search

    Brian M. Balgley; Tom Laudeman; Li Yang; Tao Song; Cheng S. Lee

    2007-01-01

    Peptide identification of tandem mass spectra by a variety of available search algorithms forms the foundation for much of modern day mass spectrometry-based proteom- ics. Despite the critical importance of proper evaluation and interpretation of the results generated by these algo- rithms there is still little consistency in their application or understanding of their similarities and differences. A sur- vey

  12. Simultaneous determination of triclocarban and triclosan in municipal biosolids by liquid chromatography tandem mass spectrometry

    Microsoft Academic Search

    Shaogang Chu; Chris D. Metcalfe

    2007-01-01

    A sensitive and accurate method was developed for the simultaneous determination of triclosan and triclocarban in sludge and treated biosolids from municipal wastewater treatment plants (WWTPs). The methods involved extraction by pressurized liquid extraction (PLE), followed by sample clean-up on a Oasis HLB solid phase extraction (SPE) cartridge and analysis by liquid chromatography with electrospray ionization and tandem mass spectrometry

  13. 10 K Ring Electrode Trap—Tandem Mass Spectrometer for Infrared Spectroscopy of Mass Selected Ions

    Microsoft Academic Search

    Daniel J. Goebbert; Gerard Meijer; Knut R. Asmis

    2009-01-01

    A novel instrumental setup for measuring infrared photodissociation spectra of buffer gas cooled, mass-selected ions is described and tested. It combines a cryogenically cooled, linear radio frequency ion trap with a tandem mass spectrometer, optimally coupling continuous ion sources to pulsed laser experiments. The use of six independently adjustable DC potentials superimposed over the trapping radio frequency field provides control

  14. 10 K Ring Electrode Trap-Tandem Mass Spectrometer for Infrared Spectroscopy of Mass Selected Ions

    Microsoft Academic Search

    Daniel J. Goebbert; Gerard Meijer; Knut R. Asmis

    2009-01-01

    A novel instrumental setup for measuring infrared photodissociation spectra of buffer gas cooled, mass-selected ions is described and tested. It combines a cryogenically cooled, linear radio frequency ion trap with a tandem mass spectrometer, optimally coupling continuous ion sources to pulsed laser experiments. The use of six independently adjustable DC potentials superimposed over the trapping radio frequency field provides control

  15. msmsEval: tandem mass spectral quality assignment for high-throughput proteomics

    Microsoft Academic Search

    Jason W. H. Wong; Matthew J. Sullivan; Hugh M. Cartwright; Gerard Cagney

    2007-01-01

    Background: In proteomics experiments, database-search programs are the method of choice for protein identification from tandem mass spectra. As amino acid sequence databases grow however, computing resources required for these programs have become prohibitive, particularly in searches for modified proteins. Recently, methods to limit the number of spectra to be searched based on spectral quality have been proposed by different

  16. Dual-Operability and Bandwidth Partitioning Enabled by an ONU With Tandem-Modulator

    Microsoft Academic Search

    Bernhard Schrenk; Johan Bauwelinck; Jose A. Lazaro; Christophe Kazmierski; Xing-Zhi Qiu; Josep Prat

    2011-01-01

    An upgrade at the physical layer regarding unbundling and dynamic bandwidth provisioning of a wave- length division multiplexed access network is presented. The capability of a reflective modulator to act as a photodetector is exploited and allows a tandem configuration to be used at the optical network unit (ONU) for flexible switching of the detection and modulation branch. Consequently, a

  17. Extension to the 350-kV negative ion injector for the JAERI tandem accelerator

    SciTech Connect

    Minehara, E.; Yoshida, T.; Abe, S.; Kanazawa, S.; Tsukihashi, Y.; Horie, K.; Hanashima, S.

    1987-02-01

    An extension to the 350-kV negative ion injector for the JAERI tandem accelerator was constructed to minimize loss of the beam time due to changing and tuning the ion sources, and to improve substantially the reliability and personal safety in the accelerator operation. Performance during the first operation over three months is reported and discussed in comparison with the previous performance.

  18. Protein Complexes Characterization in Arabidopsis thaliana by Tandem Affinity Purification Coupled

    E-print Network

    Hirt, Heribert

    in vivo protein complexes. Key words Arabidopsis thaliana, Protein complexes, Tandem affinity purification purification). The TAP method was initially developed to isolate and identify protein complexes in the yeast protocols allow the purification of better purified protein complexes compared to sin- gle-step procedures

  19. CHARACTERIZATION OF DOXYLAMINE AND PYRILAMINE METABOLITES VIA THERMOSPRAY/MASS SPECTROMETRY AND TANDEM MASS SPECTROMETRY

    EPA Science Inventory

    Analysis of doxylamine N-oxide and pyrilamine N-oxide as synthetic standards and biologically derived metabolites by thermospray mass spectrometry (TSP/MS) provided (M + H)+ ions for each metabolite. TSP/tandem mass spectrometry (TSP/MS/MS) of the (M + H)+ ions provided fragment ...

  20. Multiple-Locus Variable-Number Tandem-Repeat Analysis for Rapid Typing of Candida glabrata?

    PubMed Central

    Grenouillet, Frédéric; Millon, Laurence; Bart, Jean-Mathieu; Roussel, Sandrine; Biot, Isabelle; Didier, Emeline; Ong, Anne-Sophie; Piarroux, Renaud

    2007-01-01

    A multiple-locus variable-number tandem-repeat analysis (MLVA) using six microsatellite markers was assessed in 127 Candida glabrata isolates. Thirty-seven different genotypes, stable both in vitro and in vivo, were observed. The highest discriminatory power (D = 0.902) was reached by using only four markers. MLVA seems to be relevant for C. glabrata typing. PMID:17855568

  1. -Triggered Simultaneous Membrane Penetration of the Tandem C2-Domains of Synaptotagmin I

    E-print Network

    Chapman, Edwin R.

    Ca21 -Triggered Simultaneous Membrane Penetration of the Tandem C2-Domains of Synaptotagmin I Enfu Ca21 , C2A and C2B partially penetrate into membranes that contain anionic phospholipids. However, or in a mutually exclusive manner. We have used site-directed fluorescent probes to monitor the penetration of syt

  2. Local and long-range stability in tandemly arrayed tetratricopeptide repeats

    E-print Network

    Jackson, Sophie

    Local and long-range stability in tandemly arrayed tetratricopeptide repeats Ewan R. G. Main. Chemical denaturation, monitored by CD and fluorescence, was used to assess the folding and global, protein folding, and neurogenesis (3, 5). The uniform secondary structure and regular tertiary structure

  3. The Axisymmetric Tandem Mirror: A Magnetic Mirror Concept Game Changer Magnet Mirror Status Study Group

    Microsoft Academic Search

    T Simonen; R Cohen; D Correll; K Fowler; D Post; H Berk; W Horton; E B Hooper; N Fisch; A Hassam; D Baldwin; D Pearlstein; G Logan; B Turner; R Moir; A Molvik; D Ryutov; A A Ivanov; J Kesner; B Cohen; H McLean; T Tamano; X Z Tang; T Imai

    2008-01-01

    Experimental results, theory and innovative ideas now point with increased confidence to the possibility of a Gas Dynamic Trap (GDT) neutron source which would be on the path to an attractively simple Axisymmetric Tandem Mirror (ATM) power plant. Although magnetic mirror research was terminated in the US 20 years ago, experiments continued in Japan (Gamma 10) and Russia (GDT), with

  4. Differences in Scour for Submerged and Surface Piercing Circular Cylinders in Tandem

    NASA Astrophysics Data System (ADS)

    Pulvino, N. T.; Riley, D.; Beninati, M. L.; Krane, M.; Fontaine, A.

    2012-12-01

    An experimental study was conducted to investigate how the scour hole of surface piercing and submerged cylinders in tandem is affected by the separation of the cylinders. The study was motivated by the need to predict the environmental effects of Marine Hydrokinetic (MHK) turbines arrays where the cylinders used represent the bluff bodies of MHK turbines. Small scale experiments were performed to find scour rate and scour statistics; including: scour size and deposition. The cases studied were tandem cylinders separated by 1, 2, 3, 4, 6, 8, 10, and 12 diameters (D = 2.54 cm). These studies were performed in a test section in the hydraulic flume facility (1.22-m-wide, 0.38-m-deep, and 9.75-m-long) at Bucknell University. The bottoms of each cylinder tested were taped in 0.318 cm color-coded increments and buried beneath the sediment. This allowed for visual determination of the scour rate by looking at how many strips had been uncovered at intervals over three hours of testing at live bed conditions. Subsequently, bed form topology was measured using an HR Wallingford 2D Sediment Bed Profiler with a low-powered laser distance sensor. Results show that surface piercing cylinders in tandem consistently have a wider scour hole than submerged cylinders. Furthermore, it is determined that the threshold for when the tandem cylinders have separate scour holes occurring at a separation of 10 diameters for both sets of cylinders.

  5. Detecting short tandem repeats from genome data: opening the software black box

    Microsoft Academic Search

    Angelika Merkel; Neil Gemmell

    2008-01-01

    Short tandem repeats, specifically microsatellites, are widely used genetic markers, associated with human genetic diseases, and play an important role in various regulatory mechanisms and evolution. Despite their importance, much is yet unknown about their mutational dynamics. The increasing availability of genome data has led to several in silico studies of microsatellite evolution which have produced a vast range of

  6. Impeller tandem blade study with grid embedding for local grid refinement

    NASA Technical Reports Server (NTRS)

    Bache, George

    1992-01-01

    Flow non-uniformity at the discharge of high power density impellers can result in significant unsteady interactions between impeller blades and downstream diffuser vanes. These interactions result in degradation of both performance and pump reliability. The MSFC Pump Technology Team has recognized the importance of resolving this problem and has thus initiated the development and testing of a high head coefficient impeller. One of the primary goals of this program is to improve impeller performance and discharge flow uniformity. The objective of the present work is complimentary. Flow uniformity and performance gains were sought through the application of a tandem blade arrangement. The approach adopted was to numerically establish flow characteristics at the impeller discharge for the baseline MSFC impeller and then parametrically evaluate tandem blade configurations. A tandem design was sought that improves both impeller performance and discharge uniformity. The Navier-Stokes solver AEROVISC was used to conduct the study. Grid embedding is used to resolve local gradients while attempting to minimize model size. Initial results indicate that significant gains in flow uniformity can be achieved through the tandem blade concept and that blade clocking rather than slot location is the primary driver for flow uniformity.

  7. Recording of current accompanying an ion beam in a tandem accelerator with vacuum insulation

    NASA Astrophysics Data System (ADS)

    Kasatov, D. A.; Makarov, A. N.; Taskaev, S. Yu.; Shchudlo, I. M.

    2015-02-01

    A proton beam (2 MeV and 1.6 mA) has been obtained on a tandem accelerator with vacuum insulation. Experimental results are given that outline the reasons for current limits, and approaches to increasing the current of a proton beam are proposed.

  8. Design, characterization and fabrication of silicon solar cells for ?50% efficient 6-junction tandem solar cells

    Microsoft Academic Search

    Ngwe Soe Zin; Andrew Blakers; Evan Franklin; Vernie Everett

    2008-01-01

    A major objective for photovoltaic conversion is to develop high efficiency solar cells. Many approaches are under investigation - Multiple Junction Solar Cell, Multiple Spectrum Solar Cell, Multiple Absorption Path Solar Cell, Multiple Energy Solar Cell, and Multiple Temperature Solar Cells [1]. The Multiple Junction Solar Cell approach based on a six-junction tandem solar cell has been adopted to achieve

  9. Using Tandem Scanning Confocal Microscopy to Predict the Status of Donor Kidneys

    Microsoft Academic Search

    Peter M. Andrews; Bijan S. Khirabadi; Benjamin C. Bengs

    2002-01-01

    Tandem scanning confocal microscopy (TSCM) is a noninvasive form of vital microscopy that can be used to evaluate superficial uriniferous tubules in living kidneys. Because TSCM has a number of advantages over conventional microscopic examination of renal biopsies, the present study was undertaken to determine whether the histopathological images obtained by TSCM correlate with post-transplant renal function. The kidneys of

  10. Direct Assay of Enzymes in Heme Biosynthesis for the Detection of Porphyrias by Tandem Mass

    E-print Network

    Gelb, Michael

    Direct Assay of Enzymes in Heme Biosynthesis for the Detection of Porphyrias by Tandem Mass activity causes acute intermittent porphyria, the most common disorder of heme biosynthesis. The assay%) is significantly lower than the decrease due to acute intermittent porphyria (50%). Acute intermittent porphyria

  11. Modification of the macroscopic stability of a tandem mirror by partial line-tying

    Microsoft Academic Search

    A. W. Molvik; R. A. Breun; S. N. Golovato; Noah Hershkowitz; B. McVey; R. S. Post; D. Smatlak; L. Yujiri

    1984-01-01

    Increased stability is observed during experiments with gun injection in the Phaedrus tandem mirror. This is manifested by three effects. First, a magnetic mirror cell with bad average curvature, adjacent to a plasma gun, confines plasma with betas up to 20%. Second, the central cell, also with bad curvature, is stable at betas up to 20%, exceeding the minimum-B interchange

  12. Modelling single- and tandem-bubble dynamics between two parallel plates for biomedical applications

    PubMed Central

    Hsiao, C.-T.; Choi, J.-K.; Singh, S.; Chahine, G. L.; Hay, T. A.; Ilinskii, Yu. A.; Zabolotskaya, E. A.; Hamilton, M. F.; Sankin, G.; Yuan, F.; Zhong, P.

    2013-01-01

    Carefully timed tandem microbubbles have been shown to produce directional and targeted membrane poration of individual cells in microfluidic systems, which could be of use in ultrasound-mediated drug and gene delivery. This study aims at contributing to the understanding of the mechanisms at play in such an interaction. The dynamics of single and tandem microbubbles between two parallel plates is studied numerically and analytically. Comparisons are then made between the numerical results and the available experimental results. Numerically, assuming a potential flow, a three-dimensional boundary element method (BEM) is used to describe complex bubble deformations, jet formation, and bubble splitting. Analytically, compressibility and viscous boundary layer effects along the channel walls, neglected in the BEM model, are considered while shape of the bubble is not considered. Comparisons show that energy losses modify the bubble dynamics when the two approaches use identical initial conditions. The initial conditions in the boundary element method can be adjusted to recover the bubble period and maximum bubble volume when in an infinite medium. Using the same conditions enables the method to recover the full dynamics of single and tandem bubbles, including large deformations and fast re-entering jet formation. This method can be used as a design tool for future tandem-bubble sonoporation experiments. PMID:24293683

  13. Improving the Similarity Search of Tandem Mass Spectra using Metric Access Methods

    E-print Network

    Skopal, Tomas

    of peptide mass spectra interpretation than the cosine similarity commonly mentioned in mass spectrometryImproving the Similarity Search of Tandem Mass Spectra using Metric Access Methods Jirí Novák, Tomás Skopal, David Hoksza and Jakub Lokoc SIRET Research Group Department of Software Engineering

  14. Structural Analysis of Superconducting Choke Coil in Conceptual Design for Tandem Mirror Fusion Reactor GAMMA R

    Microsoft Academic Search

    Masakatsu SAITO; Tokuo TERAMOTO

    1986-01-01

    GAMMA R is a preliminary design study of a Tandem Mirror fusion power reactor of 3,500 MW. The ratio of the central cell magnetic field to the choke coil magnetic field has a serious influence on the plasma Q. It is desirable to construct a high field choke coil. As a first step, a superconducting magnetic coil with 20 T

  15. Analysis of the Anaplasma marginale Major Surface Protein 1 Complex Protein Composition by Tandem Mass Spectrometry

    PubMed Central

    Macmillan, Henriette; Brayton, Kelly A.; Palmer, Guy H.; McGuire, Travis C.; Munske, Gerhard; Siems, William F.; Brown, Wendy C.

    2006-01-01

    The protective major surface protein 1 (MSP1) complex of Anaplasma marginale is a heteromer of MSP1a and MSP1b, encoded by a multigene family. The msp1? sequences were highly conserved throughout infection. However, liquid chromatography-tandem mass spectrometry analysis identified only a single MSP1b protein, MSP1b1, within the MSP1 complex. PMID:16788207

  16. The heterochronic maize mutant Corngrass1 results from overexpression of a tandem microRNA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We cloned Cg1 and found that it encodes two tandem miR156 genes that are over expressed in the meristem and lateral organs. Furthermore, a target of Cg1 is teosinte glume architecture11, a gene known to have played a role in the domestication of maize from teosinte. Cg1 mutant plants overexpressing ...

  17. A Hybrid Intelligent Controller for Control of Strip Tension and Looper Height in Tandem Finishing Mill

    Microsoft Academic Search

    S. Thangavel; V. Palanisamy; K. Duraiswamy; S. Chenthur Pandian

    2006-01-01

    Strip tension control is crucial in the tandem finishing mills for its safe operation. Most of the industrial applications are of nonlinear. Fuzzy logic controller is the most useful approach to achieve the adaptive ness in the case of nonlinear system. Since fuzzy logic control provides a systematic method of incorporating human expertise and implementing non-linear system. Neural networks are

  18. Primary sequence information from intact proteins by electrospray ionization tandem mass spectrometry

    Microsoft Academic Search

    J. A. Loo; C. G. Edmonds; R. D. Smith

    1990-01-01

    Tandem mass spectrometry has been used to obtain information related to portions of the primary sequence for an intact protein, bovine ribonuclease A. Multiply charged molecular ions, generated by electrospray ionization, were collisionally dissociated at low energies in a triple quadrupole mass spectrometer to yield singly and multiply charged fragment ions that can be assigned to the known sequence of

  19. Primary Sequence Information from Intact Proteins by Electrospray Ionization Tandem Mass Spectrometry

    Microsoft Academic Search

    Joseph A. Loo; Charles G. Edmonds; Richard D. Smith

    1990-01-01

    Tandem mass spectrometry has been used to obtain information related to portions of the primary sequence for an intact protein, bovine ribonuclease A. Multiply charged molecular ions, generated by electrospray ionization, were collisionally dissociated at low energies in a triple quadrupole mass spectrometer to yield singly and multiply charged fragment ions that can be assigned to the known sequence of

  20. Tandem isomerization-decarboxylation for converting alkenoic fatty acids into alkenes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report a facile Ru-catalyzed route to alkenes from alkenoic fatty acids via a readily accessible pre-catalyst [Ru(CO)2RCO2]n. The catalyst apparently functions in a tandem mode by dynamically isomerizing the positions of double bonds in an aliphatic chain and, subsequently, decarboxylating specif...

  1. Chimeric adenoviral vector Ad5/F35-mediated APE1 siRNA enhances sensitivity of human colorectal cancer cells to radiotherapy in vitro and in vivo.

    PubMed

    Xiang, D-B; Chen, Z-T; Wang, D; Li, M-X; Xie, J-Y; Zhang, Y-S; Qing, Y; Li, Z-P; Xie, J

    2008-10-01

    Apurinic/apyrimidinic endonuclease (APE1), a bifunctional AP endonuclease/redox factor, is important in DNA repair and redox signaling, may be associated with radioresistance. Here we investigate whether targeted inhibition of APE1 can sensitize tumor cells to irradiation in vitro and in vivo. We first constructed chimeric adenoviral vector Ad5/F35 carrying human APE1 siRNA (Ad5/F35-APE1 siRNA). The infectivity of chimeric Ad5/F35 to LOVO colon cancer cells was greater than that of Ad5. APE1 was strongly expressed and nuclear factor kappaB (NF-kappaB), a downstream molecule of APE1, known as a radioresistance factor, was constitutively active in LOVO cells. Infection of LOVO cells with Ad5/F35-APE1 siRNA resulted in a dose-dependent decrease of APE1 protein and AP endonuclease activity in vitro. Ad5/F35-APE1 siRNA significantly enhanced sensitivity of LOVO cells to irradiation in clonogenic survival assays, associated with increased cell apoptosis. The APE1 expression in LOVO cells was induced by irradiation in a dose-dependent manner, accompanied with the enhancement of DNA-binding activity of NF-kappaB and Ad5/F35-APE1 siRNA effectively inhibited constitutive and irradiation-induced APE1 expression and NF-kappaB activation. In a subcutaneous nude mouse colon cancer model, Ad5/F35-APE1 siRNA (5 x 10(8) IU, intratumoral injection) inhibited the expression of APE1 protein in LOVO xenografts, and significantly enhanced inhibition of tumor growth by irradiation. In conclusion, APE1 may be involved as one of the radioresistance factors, and targeted inhibition of APE1 shows an effective means of enhancing tumor sensitivity to radiotherapy. PMID:18535621

  2. Both Polymorphic Variable Number of Tandem Repeats and Autoimmune Regulator Modulate Differential Expression of Insulin in Human Thymic Epithelial Cells

    PubMed Central

    Cai, Chuan Qi; Zhang, Tao; Breslin, Mary B.; Giraud, Matthieu; Lan, Michael S.

    2011-01-01

    OBJECTIVE Polymorphic INS-VNTR plays an important role in regulating insulin transcript expression in the human thymus that leads to either insulin autoimmunity or tolerance. The molecular mechanisms underlying the INS-VNTR haplotype-dependent insulin expression are still unclear. In this study, we determined the mechanistic components underlying the differential insulin gene expression in human thymic epithelial cells, which should have profound effects on the insulin autoimmune tolerance induction. RESEARCH DESIGN AND METHODS A repetitive DNA region designated as a variable number of tandem repeats (VNTR) is located upstream of the human insulin gene and correlates with the incidence of type 1 diabetes. We generated six class I and two class III VNTR constructs linked to the human insulin basal promoter or SV40 heterologous promoter/enhancer and demonstrated that AIRE protein modulates the insulin promoter activities differentially through binding to the VNTR region. RESULTS Here we show that in the presence of the autoimmune regulator (AIRE), the class III VNTR haplotype is responsible for an average of three-fold higher insulin expression than class I VNTR in thymic epithelial cells. In a protein-DNA pull-down experiment, AIRE protein is capable of binding to VNTR class I and III probes. Further, the transcriptional activation of the INS-VNTR by AIRE requires the insulin basal promoter. The VNTR sequence loses its activation activity when linked to a heterologous promoter and/or enhancer. CONCLUSIONS These findings demonstrate a type 1 diabetes predisposition encoded by the INS-VNTR locus and a critical function played by AIRE, which constitute a dual control mechanisms regulating quantitative expression of insulin in human thymic epithelial cells. PMID:20876716

  3. Elements in the long terminal repeat of murine retroviruses enhance stable transformation by thymidine kinase gene.

    PubMed Central

    Jolly, D J; Esty, A C; Subramani, S; Friedmann, T; Verma, I M

    1983-01-01

    We have investigated the effects of long terminal repeats (LTRs) of murine retroviruses on the frequency of obtaining stable transfectants by the herpes virus thymidine kinase (TK) gene. The results indicate that addition of LTRs enhances the number of TK+ transformants by 10-20 fold. A 5-12 fold enhancement was also observed when chromosomal DNA from either human or hamster cells was mixed with a plasmid containing LTR sequences and transfected onto LTR- cells. The LTR sequences involved in the enhancement were localized in the region which contains tandem repeats. All other regions of the LTR did not show any enhancement of stable TK+ transfectants. The location or the orientation of the enhancer sequences with respect to the TK gene did not exert any influence on the frequency of transformation. The enhancement effect does not appear to be linked to either increased numbers of chromosomal integrations or elevated levels of transcription of the TK gene. Images PMID:6300781

  4. Randomized Trial of Oral Misoprostol Treatment for Cervical Ripening Before Tandem Application in Cervix Cancer

    SciTech Connect

    Cepni, Kimia; Gul, Sule [Department of Radiation Oncology, Ministry of Health, Dr. Lutfi Kirdar Kartal Training and Research Hospital, Istanbul (Turkey); Cepni, Ismail [Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Gueralp, Onur, E-mail: dronur@hotmail.com [Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Sal, Veysel [Department of Obstetrics and Gynecology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul (Turkey); Mayadagli, Alpaslan [Department of Radiation Oncology, Ministry of Health, Dr. Lutfi Kirdar Kartal Training and Research Hospital, Istanbul (Turkey)

    2011-11-01

    Purpose: To investigate the efficacy of oral misoprostol administered to facilitate tandem application to the cervix as a part of brachytherapy in patients with cervical cancer. Methods and Materials: Eighty patients with cervical cancer who had been planned to undergo brachytherapy at Dr. Luetfi Kirdar Kartal Training and Research Hospital were evaluated in a double-blind, prospective, randomized trial. Patients were divided randomly into two groups of 40 patients. The first and second groups received 400 {mu}g of misoprostol orally and placebo, respectively, 3 h before tandem application. The two groups were compared in terms of age, diameter of tumor, parity, age at first intercourse, amount of bleeding and pain at first tandem application, length of endometrial cavity measured by hysterometer, and size of Hegar dilators used for cervical dilatation. Results: Of all cases, 63.6%, 16.3%, 10%, 6.3%, 2.5%, and 1.3% were Stage IIB, IIIB, IIIA, IVA, IIA and IIC, respectively. Mean ({+-}SD) age (range) was 49.3 {+-} 13.1 (25-83) years and 56.6 {+-} 13.2 (30-78) years in the study and control groups, respectively (p = 0.015). Age at first intercourse, diameter of tumor, parity, amount of bleeding at first tandem application, and length of endometrial cavity measured by hysterometer were not significantly different between the two groups. Pain score was significantly higher in the control group (p < 0.001). Application was significantly easier in the study group compared with controls (p < 0.001). Average size of initial Hegar dilators used for cervical dilatation was significantly higher in the study group compared with controls (p = 0.017). Conclusion: Administration of misoprostol 400 {mu}g orally for cervical ripening before tandem application facilitates the procedure, increases patient tolerability and comfort, and may decrease complication rates.

  5. Specific Tandem Repeats Are Sufficient for Paramutation-Induced Trans-Generational Silencing

    PubMed Central

    Bader, Rechien; Arteaga-Vazquez, Mario A.; Chandler, Vicki L.

    2013-01-01

    Paramutation is a well-studied epigenetic phenomenon in which trans communication between two different alleles leads to meiotically heritable transcriptional silencing of one of the alleles. Paramutation at the b1 locus involves RNA-mediated transcriptional silencing and requires specific tandem repeats that generate siRNAs. This study addressed three important questions: 1) are the tandem repeats sufficient for paramutation, 2) do they need to be in an allelic position to mediate paramutation, and 3) is there an association between the ability to mediate paramutation and repeat DNA methylation levels? Paramutation was achieved using multiple transgenes containing the b1 tandem repeats, including events with tandem repeats of only one half of the repeat unit (413 bp), demonstrating that these sequences are sufficient for paramutation and an allelic position is not required for the repeats to communicate. Furthermore, the transgenic tandem repeats increased the expression of a reporter gene in maize, demonstrating the repeats contain transcriptional regulatory sequences. Transgene-mediated paramutation required the mediator of paramutation1 gene, which is necessary for endogenous paramutation, suggesting endogenous and transgene-mediated paramutation both require an RNA-mediated transcriptional silencing pathway. While all tested repeat transgenes produced small interfering RNAs (siRNAs), not all transgenes induced paramutation suggesting that, as with endogenous alleles, siRNA production is not sufficient for paramutation. The repeat transgene-induced silencing was less efficiently transmitted than silencing induced by the repeats of endogenous b1 alleles, which is always 100% efficient. The variability in the strength of the repeat transgene-induced silencing enabled testing whether the extent of DNA methylation within the repeats correlated with differences in efficiency of paramutation. Transgene-induced paramutation does not require extensive DNA methylation within the transgene. However, increased DNA methylation within the endogenous b1 repeats after transgene-induced paramutation was associated with stronger silencing of the endogenous allele. PMID:24146624

  6. Structures of Naturally Evolved CUP1 Tandem Arrays in Yeast Indicate That These Arrays Are Generated by Unequal Nonhomologous Recombination

    PubMed Central

    Zhao, Ying; Strope, Pooja K.; Kozmin, Stanislav G.; McCusker, John H.; Dietrich, Fred S.; Kokoska, Robert J.; Petes, Thomas D.

    2014-01-01

    An important issue in genome evolution is the mechanism by which tandem duplications are generated from single-copy genes. In the yeast Saccharomyces cerevisiae, most strains contain tandemly duplicated copies of CUP1, a gene that encodes a copper-binding metallothionein. By screening 101 natural isolates of S. cerevisiae, we identified five different types of CUP1-containing repeats, as well as strains that only had one copy of CUP1. A comparison of the DNA sequences of these strains indicates that the CUP1 tandem arrays were generated by unequal nonhomologous recombination events from strains that had one CUP1 gene. PMID:25236733

  7. Analysis of the possibility of high-efficiency photovoltaic conversion in tandem heterojunction thin-layer solar cells

    NASA Astrophysics Data System (ADS)

    Sachenko, A. V.; Kryuchenko, Yu. V.; Bobyl', A. V.; Kostylyov, V. P.; Terukov, E. I.; Bogdanov, D. A.; Panaiotti, I. E.; Sokolovskyi, I. O.; Orekhov, D. L.

    2015-05-01

    The possibility of creating tandem heterojunction-with-intrinsic-thin-layer (HIT) solar cells possessing photovoltaic conversion efficiency greater than that of the best existing single-junction HIT structures is analyzed. It is established that, because of small carrier lifetimes and high degrees of compensation, the use of amorphous silicon in tandem HIT cells cannot provide for record high conversion efficiency. Key parameters of the material for a widegap p- n junction on the frontal side of tandem solar cells are determined that will allow a photovoltaic conversion efficiency above 25% under AM1.5 conditions to be reached.

  8. Oak Ridge 25URC Tandem Accelerator 2007 SNEAP Lab Report

    SciTech Connect

    Meigs, Martha J [ORNL; Juras, Raymond C [ORNL

    2008-01-01

    During FY 2008, the 25URC operated for slightly over 3,000 research hours. The radioactive species 80Ge and 17,18F accounted for 763 of these hours. This included an experiment using 17F which was only possible due to an improvement of a factor of 50 in beam intensity over our previous facility record. Twenty stable beam species were provided this year. Operation for the experimental program was at terminal potentials from 2.02 to 23.8 MV. Approximately 200 hours of conditioning were done to return the machine to operation after tank openings. There were six tank openings during the year: three scheduled for general maintenance and three unscheduled. Two of the unscheduled openings were required to correct shorting rod issues and the other was to reestablish communication with one of the major dead sections. On July 28, an event happened that caused all accelerators at the Holifield Radioactive Ion Beam Facility (HRIBF) to suspend operation. At approximately 8 AM on that Monday, during operations with approximately 12 {micro}A of 50-MeV protons on a uranium carbide target, delivering neutron-rich 81Zn beam to the new Low-energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS), a radiological control technician (RCT) reported higher than normal radiation levels just outside the shield door to the IRIS1 vault (the room in which RIBs are produced at HRIBF). The measured dose rate equivalent was 4 mrem/hr. The presence of radiological contamination on the floor just outside the shield door was subsequently noted, as was the possible presence of airborne radioactivity. These observations were reported to facility management. Accelerators were put in standby immediately and the building evacuated. The event was declared a laboratory operational emergency. Parts of the building were cleared for reentry to collect belongings on Monday afternoon. The entire building was cleared for reoccupation on Tuesday morning after a detailed radiological survey found no contamination outside the shielded vaults. No decontamination was required. No individual received any detectable radiological dose as a result of this event. The 25URC tandem accelerator was given permission to resume operation with stable beams in early September, but radioactive ion production is still not allowed. Subsequent analysis indicated a release that consisted entirely of noble gasses (Xe and Kr isotopes). We believe we have identified two unrelated failures, one associated with the HVAC system and the other with the roughing system exhaust which accounts for both the escape of noble gasses into the IRIS1 vault and their migration outside the vault. An investigation team report is expected by October 24. At that time, corrective actions will be determined and the path to future radioactive ion beam production will be known. The break from operations allowed a few upgrades to be implemented. The most notable was the installation and commissioning of a SNICS ion source purchased from National Electrostatics Corporation (NEC). The SNICS replaced the old Alton/Aarhus source that we have used for many years. An ANU style gas cathode holder was purchased also but has not yet been implemented. The first beams have been produced by the source and the biggest problem encountered was reducing the beam for very low current experiments. A new power supply for the injection magnet was installed during this period also. Radioactive ion beam (RIB) development at the High Power Target Laboratory (HPTL) has been delayed this year while installing the platforms, conduits and equipment for the second Injector for Radioactive Ion Species (IRIS2) which is co-located with the HPTL facility. The majority of development activities have been performed at the two off-line ion source test facilities (ISTF1 and ISTF2) and the On-Line Test Facility (OLTF). Both test facilities have been developing systems which will eventually be used with IRIS2. Two new tunable Ti:Sapphire lasers have been ordered for continuing development of an ion source based on laser ionization using all solid-state

  9. Oak Ridge 25URC Tandem Accelerator 2008 SNEAP Lab Report

    SciTech Connect

    Meigs, Martha J [ORNL; Juras, Raymond C [ORNL

    2011-01-01

    During FY 2008, the 25URC operated for slightly over 3,000 research hours. The radioactive species {sup 80}Ge and {sup 17,18}F accounted for 763 of these hours. This included an experiment using {sup 17}F which was only possible due to an improvement of a factor of 50 in beam intensity over our previous facility record. Twenty stable beam species were provided this year. Operation for the experimental program was at terminal potentials from 2.02 to 23.8 MV. Approximately 200 hours of conditioning were done to return the machine to operation after tank openings. There were six tank openings during the year: three scheduled for general maintenance and three unscheduled. Two of the unscheduled openings were required to correct shorting rod issues and the other was to reestablish communication with one of the major dead sections. On July 28, an event happened that caused all accelerators at the Holifield Radioactive Ion Beam Facility (HRIBF) to suspend operation. At approximately 8 AM on that Monday, during operations with approximately 12 {micro}A of 50-MeV protons on a uranium carbide target, delivering neutron-rich {sup 81}Zn beam to the new Low-energy Radioactive Ion Beam Spectroscopy Station (LeRIBSS), a radiological control technician (RCT) reported higher than normal radiation levels just outside the shield door to the IRIS1 vault (the room in which RIBs are produced at HRIBF). The measured dose rate equivalent was 4 mrem/hr. The presence of radiological contamination on the floor just outside the shield door was subsequently noted, as was the possible presence of airborne radioactivity. These observations were reported to facility management. Accelerators were put in standby immediately and the building evacuated. The event was subsequently declared a laboratory operational emergency. Parts of the building were cleared for reentry to collect belongings on Monday afternoon. The entire building was cleared for reoccupation on Tuesday morning after a detailed radiological survey found no contamination outside the shielded vaults. No decontamination was required. No individual received any detectable radiological dose as a result of this event. The 25URC tandem accelerator was given permission to resume operation with stable beams in early September, but radioactive ion production is still not allowed. Subsequent analysis indicated a release that consisted entirely of noble gasses (Xe and Kr isotopes). We believe we have identified two unrelated failures, one associated with the HVAC system and the other with the roughing system exhaust which accounts for both the escape of noble gasses into the IRIS1 vault and their migration outside the vault. An investigation team report is expected by October 24. At that time, corrective actions will be determined and the path to future radioactive ion beam production will be known. The break from operations allowed a few upgrades to be implemented. The most notable was the installation and commissioning of a SNICS ion source purchased from National Electrostatics Corporation (NEC). The SNICS replaced the old Alton/Aarhus source that we have used for many years. An ANU style gas cathode holder was purchased also but has not yet been implemented. The first beams have been produced by the source and the biggest problem encountered was reducing the beam for very low current experiments. A new power supply for the injection magnet was installed during this period also. Radioactive ion beam (RIB) development at the High Power Target Laboratory (HPTL) has been delayed this year while installing the platforms, conduits and equipment for the second Injector for Radioactive Ion Species (IRIS2) which is co-located with the HPTL facility. Therefore, the majority of development activities have been performed at the two off-line ion source test facilities (ISTF1 and ISTF2) and the On-Line Test Facility (OLTF). Both test facilities have been developing systems which will eventually be used with IRIS2. Two new tunable Ti:Sapphire lasers have been ordered for continuing development of an ion source

  10. Translation enhancer improves the ribosome liberation from translation initiation.

    PubMed

    Takahashi, Shuntaro; Furusawa, Hiroyuki; Ueda, Takuya; Okahata, Yoshio

    2013-09-01

    For translation initiation in bacteria, the Shine-Dalgarno (SD) and anti-SD sequence of the 30S subunit play key roles for specific interactions between ribosomes and mRNAs to determine the exact position of the translation initiation region. However, ribosomes also must dissociate from the translation initiation region to slide toward the downstream sequence during mRNA translation. Translation enhancers upstream of the SD sequences of mRNAs, which likely contribute to a direct interaction with ribosome protein S1, enhance the yields of protein biosynthesis. Nevertheless, the mechanism of the effect of translation enhancers to initiate the translation is still unknown. In this paper, we investigated the effects of the SD and enhancer sequences on the binding kinetics of the 30S ribosomal subunits to mRNAs and their translation efficiencies. mRNAs with both the SD and translation enhancers promoted the amount of protein synthesis but destabilized the interaction between the 30S subunit and mRNA by increasing the dissociation rate constant (koff) of the 30S subunit. Based on a model for kinetic parameters, a 16-fold translation efficiency could be achieved by introducing a tandem repeat of adenine sequences (A20) between the SD and translation enhancer sequences. Considering the results of this study, translation enhancers with an SD sequence regulate ribosomal liberation from translation initiation to determine the translation efficiency of the downstream coding region. PMID:23927491

  11. Small tandemly repeated DNA sequences of higher plants likely originate from a tRNA gene ancestor.

    PubMed Central

    Benslimane, A A; Dron, M; Hartmann, C; Rode, A

    1986-01-01

    Several monomers (177 bp) of a tandemly arranged repetitive nuclear DNA sequence of Brassica oleracea have been cloned and sequenced. They share up to 95% homology between one another and up to 80% with other satellite DNA sequences of Cruciferae, suggesting a common ancestor. Both strands of these monomers show more than 50% homology with many tRNA genes; the best homologies have been obtained with Lys and His yeast mitochondrial tRNA genes (respectively 64% and 60%). These results suggest that small tandemly repeated DNA sequences of plants may have evolved from a tRNA gene ancestor. These tandem repeats have probably arisen via a process involving reverse transcription of polymerase III RNA intermediates, as is the case for interspersed DNA sequences of mammalians. A model is proposed to explain the formation of such small tandemly repeated DNA sequences. Images PMID:3774553

  12. Power generation of series and series/parallel triple junction tandem solar cells derived from measured spectra in Japan

    NASA Astrophysics Data System (ADS)

    Naito, Shunya; Okada, Yoshitaka

    2013-09-01

    A limiting efficiency of a solar cell changes according to the incident solar spectrum. With respect to a two-terminal triple junction tandem solar cell and interconnection of individual cells within it, the variation of limiting efficiency of a modified triple-tandem solar cell, in which two series-connected bottom cells are connected in parallel to the top cell, is lower than that of a conventional fully series-connected tandem cell. We calculate limiting efficiency of these two structures using measured solar spectra and meteorological condition at four different locations in Japan. It is shown that a triple junction tandem cell in a combination of series and parallel connections generates 7% larger amount of power than a series-connected cell does in average if these cells are optimized at airmass (AM) 1.5.

  13. Genomic Diversity at Thirteen Short Tandem Repeat Loci in a Substructured Caste Population, Golla, of Southern Andhra Pradesh, India

    E-print Network

    Reddy, B Mohan; Sun, Guangyun; Luis, Javier Rodriguez; Crawford, Michael H; Hemam, Natabar Shyam; Deka, Ranjan

    2001-04-01

    Genomic diversity based on 13 short tandem repeat (STR) loci was studied in seven population groups of a substructured Golla caste from Chittoor district in southern Andhra Pradesh, India. These groups are traditionally pastoral, culturally...

  14. DETERMINATION OF PHTHALATES IN WATER AND SOIL BY TANDEM MASS SPECTROMETRY UNDER CHEMICAL IONIZATION CONDITIONS WITH ISOBUTANE AS REAGENT GAS

    EPA Science Inventory

    Phthalate determination is important because phthalates often are major impurities in samples and can have significant health effects. Tandem mass spectrometry under chemical ionization mass spectrometry conditions with isobutane as the reagent gas was used to determine 11 phthal...

  15. Identification and characterization of tandem repeats in exon III of dopamine receptor D4 (DRD4) genes from different mammalian species.

    PubMed

    Larsen, Svend Arild; Mogensen, Line; Dietz, Rune; Baagøe, Hans Jørgen; Andersen, Mogens; Werge, Thomas; Rasmussen, Henrik Berg

    2005-12-01

    In this study we have identified and characterized dopamine receptor D4 (DRD4) exon III tandem repeats in 33 public available nucleotide sequences from different mammalian species. We found that the tandem repeat in canids could be described in a novel and simple way, namely, as a structure composed of 15- and 12- bp modules. Tandem repeats composed of 18-bp modules were found in sequences from the horse, zebra, onager, and donkey, Asiatic bear, polar bear, common raccoon, dolphin, harbor porpoise, and domestic cat. Several of these sequences have been analyzed previously without a tandem repeat being found. In the domestic cow and gray seal we identified tandem repeats composed of 36-bp modules, each consisting of two closely related 18-bp basic units. A tandem repeat consisting of 9-bp modules was identified in sequences from mink and ferret. In the European otter we detected an 18-bp tandem repeat, while a tandem repeat consisting of 27-bp modules was identified in a sequence from European badger. Both these tandem repeats were composed of 9-bp basic units, which were closely related with the 9-bp repeat modules identified in the mink and ferret. Tandem repeats could not be identified in sequences from rodents. All tandem repeats possessed a high GC content with a strong bias for C. On phylogenetic analysis of the tandem repeats evolutionary related species were clustered into the same groups. The degree of conservation of the tandem repeats varied significantly between species. The deduced amino acid sequences of most of the tandem repeats exhibited a high propensity for disorder. This was also the case with an amino acid sequence of the human DRD4 exon III tandem repeat, which was included in the study for comparative purposes. We identified proline-containing motifs for SH3 and WW domain binding proteins, potential phosphorylation sites, PDZ domain binding motifs, and FHA domain binding motifs in the amino acid sequences of the tandem repeats. The numbers of potential functional sites varied pronouncedly between species. Our observations provide a platform for future studies of the architecture and evolution of the DRD4 exon III tandem repeat, and they suggest that differences in the structure of this tandem repeat contribute to specialization and generation of diversity in receptor function. PMID:16332176

  16. High-efficiency p\\/n In0.53Ga0.47As solar cell for tandem applications

    Microsoft Academic Search

    A. Bensaoula; N. Medelci; M. F. Vilela; A. Freundlich; S. Taylor; B. Beaumont

    1994-01-01

    InP-based multijunction tandem solar cells show great promise for high conversion efficiency (?) and high radiation resistance. InP and its related ternary and quaternary compound semiconductors such InGaAs and InGaAsP offer desirable combinations of energy bandgap values which are very suitable for multijunction tandem solar cell applications. In this work we present results on an InGaAs solar cell with a

  17. Experimental and simulation analysis of the dye sensitized solar cell\\/Cu(In,Ga)Se 2 solar cell tandem structure

    Microsoft Academic Search

    W. L. Wang; H. Lin; J. Zhang; X. Li; A. Yamada; M. Konagai; J. B. Li

    2010-01-01

    A novel tandem structure composed of dye sensitized solar cell (DSC) and CuInGaSe2 (CIGS) solar cell shows the potential to increase conversion efficiency by fully utilizing the sunlight. In our research, a tandem solar cell with a high open-circuit voltage of 1.15V and a conversion efficiency of 10.46%, which is both larger than that of DSC and CIGS solar cell

  18. Design of a tandem target for a simultaneous production of C-11 and F-18 with 18 MeV

    Microsoft Academic Search

    Min Goo Hur; Sang Wook Kim; Seung Dae Yang; In Su Jung; Tae Keun Yang; Hong Suk Chang; Bong Hwan Hong; Joon Sun Kang; Dong Hyun An; Jong-Seo Chai; Kook Hyun Yu

    2007-01-01

    A tandem target for the simultaneous production of [18F]-fluoride and [11C]CH4 with 18MeV protons has been manufactured and evaluated. Tungsten was chosen as a grid material because of its good mechanical and thermal properties. Four tungsten grids were placed between the liquid target cavities and between the air cooling units. This tandem target system showed a stable production yield and

  19. Design of a tandem target for a simultaneous production of C-11 and F-18 with 18 MeV

    Microsoft Academic Search

    Min Goo Hur; Sang Wook Kim; Seung Dae Yang; In Su Jung; Tae Keun Yang; Hong Suk Chang; Bong Hwan Hong; Joon Sun Kang; Dong Hyun An; Jong-Seo Chai; Kook Hyun Yu

    2007-01-01

    A tandem target for the simultaneous production of [18F]-fluoride and [11C]CH4 with 18 MeV protons has been manufactured and evaluated. Tungsten was chosen as a grid material because of its good mechanical and thermal properties. Four tungsten grids were placed between the liquid target cavities and between the air cooling units. This tandem target system showed a stable production yield

  20. Comprehensive multi-residue method for the target analysis of pesticides in crops using liquid chromatography–tandem mass spectrometry

    Microsoft Academic Search

    Maurice Hiemstra; André de Kok

    2007-01-01

    A liquid chromatography–tandem quadrupole mass spectrometry (LC–MS\\/MS) multi-residue method for the simultaneous target analysis of a wide range of pesticides and metabolites in fruit, vegetables and cereals has been developed. Gradient elution has been used in conjunction with positive mode electrospray ionization tandem mass spectrometry to detect up to 171 pesticides and\\/or metabolites in different crop matrices using a single

  1. Tandem Germline RET Mutations in a Family Pathogenetic for Multiple Endocrine Neoplasia 2B, Confirmed by a Natural Experiment

    PubMed Central

    Kihara, Minoru; Miyauchi, Akira; Yoshida, Hiroshi; Yamada, Osamu; Masuoka, Hiroo; Yabuta, Tomonori; Higashiyama, Takuya; Fukushima, Mitsuhiro; Ito, Yasuhiro; Kobayashi, Kaoru; Miya, Akihiro

    2014-01-01

    A family with germline tandem V804M/Y806C mutations in the RET proto-oncogene was reported. The in vitro study results showing that these mutations were on the same allele and that RET with these mutations had a moderate transforming activity were confirmed by the clinical features of the offspring as a natural experiment. Thus, the tandem double RET mutations are pathogenetic for MEN 2B. PMID:25759805

  2. Identification of phosphorylation sites in phosphopeptides by positive and negative mode electrospray ionization-tandem mass spectrometry

    Microsoft Academic Search

    Mark Busman; Kevin L. Schey; John E. Oatis; Daniel R. Knapp

    1996-01-01

    A series of synthetic mono- and diphosphorylated peptides has been analyzed by positive and negative mode electrospray ionization-tandem\\u000a mass spectrometry. The synthetic peptides are serine- and threonine-phosphorylated analogs of proteolytic fragments from the\\u000a C-terminal region of rhodopsin. Use of positive and negative modes of electrospray ionization to produce ions for tandem mass\\u000a spectrometry via low energy collision-induced dissociation was explored.

  3. The biological effects of simple tandem repeats: Lessons from the repeat expansion diseases

    PubMed Central

    Usdin, Karen

    2008-01-01

    Tandem repeats are common features of both prokaryote and eukaryote genomes, where they can be found not only in intergenic regions but also in both the noncoding and coding regions of a variety of different genes. The repeat expansion diseases are a group of human genetic disorders caused by long and highly polymorphic tandem repeats. These disorders provide many examples of the effects that such repeats can have on many biological processes. While repeats in the coding sequence can result in the generation of toxic or malfunctioning proteins, noncoding repeats can also have significant effects including the generation of chromosome fragility, the silencing of the genes in which they are located, the modulation of transcription and translation, and the sequestering of proteins involved in processes such as splicing and cell architecture. PMID:18593815

  4. Lightweight concentrator module with 30 percent AM0 efficient GaAs/GaSb tandem cells

    NASA Technical Reports Server (NTRS)

    Avery, J. E.; Fraas, L. M.; Sundaram, V. S.; Mansoori, N.; Yerkes, J. W.; Brinker, D. J.; Curtis, H. B.; O'Neill, M. J.

    1990-01-01

    A concept is presented for an aerospace concentrator module with lightweight domed lenses and 30 percent AM0 efficient GaAs/GaSb tandem solar cell circuits. The performance of transparent GaAs cells is reviewed. NASA's high-altitude jet flight calibration data for recent GaSb cells assembled with bulk GaAs filters are reported, along with subsequent Boeing and NASA measurements of GaSb I-V performance at various light levels and temperatures. The expected performance of a basic two-terminal tandem concentrator circuit with three-to-one voltage matching is discussed. All of the necessary components being developed to assemble complete flight test coupons are shown. Straightforward interconnect and assembly techniques yield voltage matched circuits with near-optimum performance over a wide temperature range.

  5. From relative to absolute quantification of tryptic peptides with tandem mass tags: application to cerebrospinal fluid.

    PubMed

    Dayon, Loïc; Turck, Natacha; Scherl, Alexander; Hochstrasser, Denis F; Burkhard, Pierre R; Sanchez, Jean-Charles

    2010-01-01

    Quantification is a major task in proteomics. Among the different analytical strategies to enable peptide and protein quantification, tagging with isotopic labels has emerged as a practical, versatile, and efficient alternative. In particular, isobaric labels, such as TMT or iTRAQ, are now widely employed to make relative comparison of the protein amounts in separate biological samples with tandem mass spectrometry (MS/MS). We used herein a shotgun proteomic approach based on labelling with tandem mass tags (TMTs) for the relative quantification of proteins, and the absolute quantification of their tryptic peptides in human cerebrospinal fluid (CSF). First, the comparison of ante- and post-mortem CSF samples was carried out for the discovery of protein marker candidates of brain-damage disorders. Second, tryptic peptides representative of these candidates were measured in CSF using reporter-ion calibration curves. These works highlighted the advantages and limitations of such strategies for quantification purposes in proteomics. PMID:21140904

  6. Rapid method for Mycobacterium tuberculosis identification using electrospray ionization tandem mass spectrometry analysis of mycolic acids.

    PubMed

    Szewczyk, Rafa?; Kowalski, Konrad; Janiszewska-Drobinska, Beata; Druszczy?ska, Magdalena

    2013-07-01

    Mycolic acids (MAs), which play a crucial role in the architecture of mycobacterial cell walls, were analyzed using electrospray ionization tandem mass spectrometry. A targeted analysis based on the 10 most abundant and characteristic multiple reaction monitoring pairs was used to profile the crude fatty acid mixtures from Mtb and several nontuberculous mycobacterial strains. Comparative analysis yielded unique profiles for MAs, enabling the reliable identification of mycobacterial species. In a case-control study of tuberculosis (TB) and non-TB Polish patients, we demonstrated the potential diagnostic utility of our approach for the rapid diagnosis of active TB with sensitivity and specificity surpassing those of existing methods. This robust method allows the identification of TB-positive patients after 2 h of sample preparation in the case of direct sputum analysis or 10 days of culturing, both of which are followed by 1 min of liquid chromatography-tandem mass spectrometry analysis. PMID:23669043

  7. MOCVD growth of high efficiency current-matched {AlGaAs}/{Si} tandem solar cell

    NASA Astrophysics Data System (ADS)

    Soga, T.; Baskar, K.; Kato, T.; Jimbo, T.; Umeno, M.

    1997-04-01

    The improvements of the AlGaAs crystal quality grown on Si substrate and the {AlGaAs}/{Si} tandem solar cell have been studied by varying the growth conditions and solar cell structure. The crystal quality of the AlGaAs layer was evaluated by time resolved photoluminescence and double crystal X-ray diffraction while varying the thermal cycle annealing temperature. The optimum thermal cycle annealing temperature and the buffer layer thickness for the growth of high efficiency {AlGaAs}/{Si} tandem solar cells have been presented. The active-area conversion efficiency of 21.2 and 21.4% (AM 0 and 1 sun at 27°C) has been demonstrated with two-terminal and four-terminal configurations, respectively, by perfect photocurrent matching between the top cell and the bottom cell.

  8. The crystal structure of an RNA oligomer incorporating tandem adenosine-inosine mismatches.

    PubMed Central

    Carter, R J; Baeyens, K J; SantaLucia, J; Turner, D H; Holbrook, S R

    1997-01-01

    The X-ray crystallographic structure of the RNA duplex [r(CGCAIGCG)]2 has been refined to 2.5 A. It shows a symmetric internal loop of two non-Watson-Crick base pairs which form in the middle of the duplex. The tandem A-I/I-A pairs are related by a crystallographic two-fold axis. Both A(anti)-I(anti) mismatches are in a head-to-head conformation forming hydrogen bonds using the Watson-Crick positions. The octamer duplexes stack above one another in the cell forming a pseudo-infinite helix throughout the crystal. A hydrated calcium ion bridges between the 3'-terminal of one molecule and the backbone of another. The tandem A-I mismatches are incorporated with only minor distortion to the backbone. This is in contrast to the large helical perturbations often produced by sheared G-A pairs in RNA oligonucleotides. PMID:9321667

  9. Pyramidal surface textures for light trapping and antireflection in perovskite-on-silicon tandem solar cells.

    PubMed

    Schneider, Bennett W; Lal, Niraj N; Baker-Finch, Simeon; White, Thomas P

    2014-10-20

    Perovskite-on-silicon tandem solar cells show potential to reach > 30% conversion efficiency, but require careful optical control. We introduce here an effective light-management scheme based on the established pyramidal texturing of crystalline silicon cells. Calculations show that conformal deposition of a thin film perovskite solar cell directly onto the textured front surface of a high efficiency silicon cell can yield front surface reflection losses as low as 0.52mA/cm(2). Combining this with a wavelength-selective intermediate reflector between the cells additionally provides effective light-trapping in the high-bandgap top cell, resulting in calculated absolute efficiency gains of 2 - 4%. This approach provides a practical and effective method to adapt existing high efficiency silicon cell designs for use in tandem cells, with conversion efficiencies approaching 35%. PMID:25607299

  10. Investigations on a radial compressor tandem-rotor stage with adjustable geometry

    NASA Astrophysics Data System (ADS)

    Josuhn-Kadner, B.; Hoffmann, B.

    1992-06-01

    A radial compressor stage has been investigated experimentally for aerodynamic stage optimization. The rotor consists of a profiled axial inducer and a conventionally designed radial impeller. Inducer and impeller can be locked at different circumferential positions relative to each other thus, forming a tandem wheel with adjustable geometry. Conventional and laser-2-focus system measurements for the tandem-rotor and the stage were performed at different operating points to study the influence of the circumferential clearance geometry between inducer and impeller with respect to compressor characteristics and performance. Furthermore, 3D Navier-Stokes calculations are being developed at design point condition to analyze the flow field. Small influence of the inducer adjustment on the rotor characteristics is observed. The maximum rotor efficiency of 93.5 percent varies in a range of less than 1 percent depending on the different inducer positions.

  11. The molecular organisation of a B chromosome tandem repeat sequence from Brachycome dichromosomatica.

    PubMed

    Franks, T K; Houben, A; Leach, C R; Timmis, J N

    1996-10-01

    A high copy, tandemly repeated, sequence (Bd49) specific to the B chromosome and located near the centromere in Brachycome dichromosomatica was used to identify lambda genomic clones from DNA of a 3B plant. Only one clone of those analysed was composed entirely of a tandem array of the B-specific repeat unit. In other clones, the Bd49 repeats were linked to, or interspersed with, sequences that are repetitious and distributed elsewhere on the A and B chromosomes. One such repetitious flanking sequence has similarity to retrotransposon sequences and a second is similar to chloroplast DNA sequences. Of the four separate junctions analysed of Bd49-like sequence with flanking sequence, three were associated with the same A/T-rich region in Bd49 and the fourth was close to a 25 bp imperfect dyadic sequence. No novel B-specific sequences were detected within the genomic clones. PMID:8854881

  12. A transposable element can drive the concerted evolution of tandemly repetitious DNA.

    PubMed

    Thompson-Stewart, D; Karpen, G H; Spradling, A C

    1994-09-13

    Recombination and conversion have been proposed to drive the concerted evolution of tandemly repeated DNA sequences. However, specific correction events within the repeated genes of multicellular organisms have not been observed directly, so their nature has remained speculative. We investigated whether the excision of transposable P elements from tandemly repeated sequences would induce unequal gene conversion. Genetically marked elements located in a subtelomeric repeat were mobilized, and the structure of the region was analyzed in progeny. We observed that the number of repeats was frequently altered. Decreases were more common than increases, and this bias probably resulted from intrinsic mechanisms governing P element-induced double-strand break repair. Our results suggest that transposable elements play an important role in the evolution of repetitious DNA. PMID:8090766

  13. Non-Target Screening of Veterinary Drugs Using Tandem Mass Spectrometry on SmartMass

    NASA Astrophysics Data System (ADS)

    Xia, Bing; Liu, Xin; Gu, Yu-Cheng; Zhang, Zhao-Hui; Wang, Hai-Yan; Ding, Li-Sheng; Zhou, Yan

    2013-05-01

    Non-target screening of veterinary drugs using tandem mass spectrometric data was performed on the SmartMass platform. This newly developed software uses the characteristic fragmentation patterns (CFP) to identify chemicals, especially those containing particular substructures. A mixture of 17 sulfonamides was separated by ultra performance liquid chromatography (UPLC), and SmartMass was used to process the tandem mass spectrometry (MS/MS) data acquired on an Orbitrap mass spectrometer. The data were automatically extracted, and each sulfonamide was recognized and analyzed with a prebuilt analysis rule. By using this software, over 98 % of the false candidate structures were eliminated, and all the correct structures were found within the top 10 of the ranking lists. Furthermore, SmartMass could also be used to identify slightly modified contraband drugs and metabolites with simple prebuilt rules. [Figure not available: see fulltext.

  14. Simulation of drift-cyclotron-loss-cone modes in tandem mirrors with sloshing ions

    SciTech Connect

    Cohen, B.I.; Maron, N.; Nevins, W.M.

    1984-03-01

    Particle simulations of drift-cyclotron-loss-cone modes in a tandem-mirror end cell confirm that sloshing-ion distributions and the concomitant trapping of low-energy ions by a depression in the ambipolar potential lead to improved microstablity. The simulations study the influences of neutral-beam-injection angle, the magnetic-mirror ratio, the size of the depression in the ambipolar potential, and warm streaming plasma on both plasma confinement and drift-cone instability. A simple nonlinear theory of velocity-space transport predicts wave amplitudes and end-loss rates at steady state that are reasonably consistent with the simulation results. This study supports both the basic strategy for sloshing-ion operation of tandem mirrors and corroborates the first measurements of ion-cyclotron modes in the TMX-Upgrade experiment at the Lawrence Livermore National Laboratory.

  15. Tandem and triple-junction polymer:nanocrystal hybrid solar cells consisting of identical subcells.

    PubMed

    Lu, Haipeng; Bartynski, Andrew N; Greaney, Matthew J; Thompson, Mark E; Brutchey, Richard L

    2014-10-22

    Tandem and triple-junction polymer:nanocrystal hybrid solar cells with identical subcells based on P3HT:CdSe nanocrystal bulk heterojunctions (BHJs) are reported for the first time showing 2-fold and 3-fold increases of open-circuit voltage (VOC), respectively, relative to the single-junction cell. A combination of nanocrystalline ZnO and pH-neutral PEDOT:PSS is used as the interconnecting layer, and the thicknesses of subcells are optimized with the guidance of optical simulations. As a result, the average power conversion efficiency (PCE) exhibits a significant increase from 2.0% (VOC = 0.57 V) in single-junction devices to 2.7% (champion 3.1%, VOC = 1.28 V) in tandem devices and 2.3% (VOC = 1.98 V) in triple-junction devices. PMID:25233268

  16. Vacuum-free and metal electrode-free organic tandem solar cells

    NASA Astrophysics Data System (ADS)

    Tong, Jinhui; Xiong, Sixing; Li, Zaifang; Jiang, Fangyuan; Mao, Lin; Meng, Wei; Zhou, Yinhua

    2015-02-01

    We report on vacuum-free and metal electrode-free organic tandem solar cells that use conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the top electrode. The PEDOT:PSS top electrode was deposited via film-transfer lamination that does not need high-vacuum processing. The fabricated tandem solar cells exhibit an open-circuit voltage of 1.62 V, which is nearly the sum of the VOC of individual subcells, a high fill factor up to 0.72, and averaged power conversion efficiency of 3.6% under 100 mW cm-2 AM 1.5 illumination. The effect of the patterning of charge recombination layer and electrodes on the device performance has also been discussed.

  17. GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators

    SciTech Connect

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2005-08-01

    We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

  18. Monolithic InP/Ga0.47In0.53As tandem solar cells for space

    NASA Technical Reports Server (NTRS)

    Wanlass, M. W.; Ward, J. S.; Coutts, T. J.; Emery, K. A.; Gessert, T. A.; Osterwald, C. R.

    1991-01-01

    A review is provided of progress made in the development of InP/Ga(0.47)In(0.53)As monolithic tandem solar cells since the last SPRAT conference. Improved one-sun, three terminal tandem designs have resulted in Air Mass Zero (AM0) efficiencies as high as 23.9 pct. at 25 C. Additionally, high efficiency concentrator versions of the three terminal device were developed. The best concentrator tandem has a peak AM0 efficiency of 28.8 pct. under 40.3 suns at 25 C. For the concentrator tandems, the subcell performance parameter temperature coefficients are reported as a function of the concentration ratio. Results from a computer modeling study are presented which provide a clear direction for improving the efficiency of the concentrator tandem. The prospects for fabricating high efficiency, series connected (i.e., two terminal) InP/Ga(0.47)In(0.53)As monolithic tandem cells are also discussed.

  19. Tandem duplications of the FLT3 receptor gene are associated with leukemic transformation of myelodysplasia

    Microsoft Academic Search

    S Horiike; S Yokota; M Nakao; T Iwai; Y Sasai; H Kaneko; M Taniwaki; K Kashima; H Fujii; T Abe; S Misawa

    1997-01-01

    We recently reported an internal tandem duplication of the human flt3 receptor gene (FLT3) as a somatic mutation in 17% of acute myelogenous leukemia (AML). The present study revealed the duplication at the juxtamembrane and the first tyrosine kinase domains of FLT3 in seven of 92 (8%) patients with myelodysplastic syndrome (MDS) and AML with trilineage myelodysplasia (AML\\/TMDS), the diseases

  20. High energy collisions on tandem time-of-flight mass spectrometers.

    PubMed

    Cotter, Robert J

    2013-05-01

    Long before the introduction of matrix-assisted laser desorption/ionization (MALDI), electrospray ionization (ESI), Orbitraps, and any of the other tools that are now used ubiquitously for proteomics and metabolomics, the highest performance mass spectrometers were sector instruments, providing high resolution mass measurements by combining an electrostatic energy analyzer (E) with a high field magnet (B). In its heyday, the four sector mass spectrometer (or EBEB) was the crown jewel, providing the highest performance tandem mass spectrometry using single, high energy collisions to induce fragmentation. During a time in which quadrupole and tandem triple quadrupole instruments were also enjoying increased usage and popularity, there were, nonetheless, some clear advantages for sectors over their low collision energy counterparts. Time-of-flight (TOF) mass spectrometers are high voltage, high vacuum instruments that have much in common with sectors and have inspired the development of tandem instruments exploiting single high energy collisions. In this retrospective, we recount our own journey to produce high performance TOFs and tandem TOFs, describing the basic theory, problems, and the advantages for such instruments. An experiment testing impulse collision theory (ICT) underscores the similarities with sector mass spectrometers where this concept was first developed. Applications provide examples of more extensive fragmentation, side chain cleavages, and charge-remote fragmentation, also characteristic of high energy sector mass spectrometers. Moreover, the so-called curved-field reflectron has enabled the design of instruments that are simpler, collect and focus all of the ions, and may provide the future technology for the clinic, for tissue imaging, and the characterization of microorganisms. PMID:23519928