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Sample records for orthogonal injection tof

  1. A novel ion trap that enables high duty cycle and wide m/z range on an orthogonal injection TOF mass spectrometer.

    PubMed

    Loboda, Alexander V; Chernushevich, Igor V

    2009-07-01

    Although TOF analyzers with orthogonal ion injection provide the whole spectrum without scanning, their duty cycle is low compared with scanning analyzers in single ion monitoring mode. Typical duty cycle is in the range of 5% to 30% depending on the instrument geometry and ion m/z value. We present here a novel trapping/releasing setup, which offers the duty cycle near 100% over a wide range. Operation in the mass range from m/z 120 to almost 2000 is demonstrated. Ions are trapped in a short linear ion trap at the end of the collision cell in an axial pseudopotential well created by additional rf ("AC") voltage applied to all four rods of the trap with the same amplitude and phase. The pseudopotential created by AC field is mass dependent, and by ramping down the AC voltage, ions can be released from the trap sequentially from high m/z to low, while all ions are gaining the same kinetic energy. Upon entering the TOF accelerator, ions with lower m/z catch up with heavier ions, and the AC ramp parameters can be selected to make all ions meet in the center of the TOF extraction region, resulting in sensitivity gains from 3 to 14 without loss of mass accuracy or resolution.

  2. Orthogonal ion injection apparatus and process

    DOEpatents

    Kurulugama, Ruwan T; Belov, Mikhail E

    2014-04-15

    An orthogonal ion injection apparatus and process are described in which ions are directly injected into an ion guide orthogonal to the ion guide axis through an inlet opening located on a side of the ion guide. The end of the heated capillary is placed inside the ion guide such that the ions are directly injected into DC and RF fields inside the ion guide, which efficiently confines ions inside the ion guide. Liquid droplets created by the ionization source that are carried through the capillary into the ion guide are removed from the ion guide by a strong directional gas flow through an inlet opening on the opposite side of the ion guide. Strong DC and RF fields divert ions into the ion guide. In-guide orthogonal injection yields a noise level that is a factor of 1.5 to 2 lower than conventional inline injection known in the art. Signal intensities for low m/z ions are greater compared to convention inline injection under the same processing conditions.

  3. Intraspecific variations in Conus purpurascens injected venom using LC/MALDI-TOF-MS and LC-ESI-TripleTOF-MS.

    PubMed

    Rodriguez, Alena M; Dutertre, Sebastien; Lewis, Richard J; Marí, Frank

    2015-08-01

    The venom of cone snails is composed of highly modified peptides (conopeptides) that target a variety of ion channels and receptors. The venom of these marine gastropods represents a largely untapped resource of bioactive compounds of potential pharmaceutical value. Here, we use a combination of bioanalytical techniques to uncover the extent of venom expression variability in Conus purpurascens, a fish-hunting cone snail species. The injected venom of nine specimens of C. purpurascens was separated by reversed-phase high-performance liquid chromatography (RP-HPLC), and fractions were analyzed using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) in parallel with liquid chromatography-electrospray ionization (LC-ESI)-TripleTOF-MS to compare standard analytical protocols used in preparative bioassay-guided fractionations with a deeper peptidomic analysis. Here, we show that C. purpurascens exhibits pronounced intraspecific venom variability. RP-HPLC fractionation followed by MALDI-TOF-MS analysis of the injected venom of these nine specimens identified 463 distinct masses, with none common to all specimens. Using LC-ESI-TripleTOF-MS, the injected venom of these nine specimens yielded a total of 5517 unique masses. We also compare the injected venom of two specimens with their corresponding dissected venom. We found 2566 and 1990 unique masses for the dissected venom compared to 941 and 1959 masses in their corresponding injected venom. Of these, 742 and 1004 masses overlapped between the dissected and injected venom, respectively. The results indicate that larger conopeptide libraries can be assessed by studying multiple individuals of a given cone snail species. This expanded library of conopeptides enhances the opportunities for discovery of molecular modulators with direct relevance to human therapeutics. Graphical Abstract The venom of cone snails are extraordinarily complex mixtures of highly modified peptides. Venom

  4. The 2nd order focusing sector field type TOF mass analyzer with an orthogonal ion acceleration for LC-IMS-MS.

    PubMed

    Poteshin, S S; Zarakovsky, A I

    2017-03-15

    Original orthogonal acceleration (OA) electrostatic sector time of flight (TOF) mass analyzer is proposed those allows the second order focusing of time of flight by initial ions position. Resolving power aberration limit exceeding 80,000 FW (full width mass peak) was shown to be obtainable for mass analyzer with the total length of flight L=133.2cm, the average ion energy 3700V and the ion energy spread of 2.5% on the entrance of sector field.

  5. Investigation of injection molding of orthogonal fluidic connector for microfluidic devices

    NASA Astrophysics Data System (ADS)

    Xu, Zheng; Cao, Dong; Zhao, Wei; Song, Man-cang; Liu, Jun-shan

    2017-02-01

    Orthogonal fluidic connections are essential for developing multilayered microfluidic devices. At present, most orthogonal connectors are realized by a horizontal channel and a vertical channel in different plates. Therefore, some extra alignment and adhesion processes for precise plate assembly are required. In this paper, the method of injection molding is proposed to make a one-body-type orthogonal connector in a single plastic plate. The connector was composed of a cantilevered tube and the other in the substrate. An injection mold was developed in which a side core-pulling mechanism and an ejection mechanism of push-pipes were combined to form the mold for an orthogonal connector. Both the type and the location of gate were optimized for the mold. The results showed that the fan gate in the middle position of the plate was the most suitable in term of both defect control and practicability. The effect of melt temperature was numerically investigated and then verified experimentally. With the optimized parameters, the relative length and the relative wall thickness of a cantilevered tube in the plastic part can reach 98.89% and 99.80%, respectively. Furthermore, using the plastic part as a cover plate, a three-layer plastic microfluidic device was conveniently fabricated for electrochemical detection.

  6. Inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (ICP-oa-TOF-MS) analysis of heavy metal content in Indocalamus tesselatus samples.

    PubMed

    Qin, Yuyue; Zhang, Zhihong; Li, Lin; Chen, Chunsheng; Shun, Sha; Huang, Yinchuan

    2013-12-01

    Indocalamus tesselatus is one of the most popular packing materials in China. Heavy metals in Chinese I. tesselatus samples have received great interest because they are related to health. A simple and fast method for the determination of Pb, Cd, Mn, Ni, Cr, As, Hg, Cu and Zn, by inductively coupled plasma orthogonal acceleration time-of-flight mass spectrometry (ICP-oa-TOF-MS), following microwave closed vessel digestion of samples, was proposed. The method was validated using standard reference material (GBW 07605-Tea). Samples of I. tesselatus from five different regions of China were analysed using the proposed method. Heavy metals contents from different regions were found at different levels. Their low contents of heavy metals showed that collection areas were not polluted and all collected I. tesselatus samples could be unreservedly used as food packing materials without any health risk.

  7. The 2nd Order Focusing by Energy for TOF Sector Field Mass Analyzer with an Orthogonal Acceleration: Theory, Modeling, Experiment

    NASA Astrophysics Data System (ADS)

    Poteshin, S. S.; Chernyshev, D. M.; Sysoev, Alexey A.; Sysoev, Alexander A.

    Currently axially symmetric type of analyzer with an electrostatic sector fields (AESF) is rarely used to construct time-of-flight mass spectrometers. The main drawback, hindering the wider use of the analyzers of this type, is the lack of chromatic second-order focusing by energy. However, the configuration of AESF in combination with orthogonal accelerator (OA) allows to achieved it through compensation of energy aberrations of the analyzer in the system of orthogonal input of the ion beam. In the presented work the results of theoretical calculation, simulation and experimentally obtained data are compared. Characteristics of the analyzer with OA in a large extent depend on the parameters of the incoming ion beam. Data of modeling the 2nd stage of gas-dynamic interface, which have the greatest influence on the parameters of the ion beam, is provided.

  8. Rapid Identification and Assignation of the Active Ingredients in Fufang Banbianlian Injection Using HPLC-DAD-ESI-IT-TOF-MS.

    PubMed

    Li, Sensen; Lin, Zongtao; Jiang, Haixiu; Tong, Lingkun; Wang, Hong; Chen, Shizhong

    2016-08-01

    Fufang Banbianlian Injection (FBI) is a well-known traditional Chinese medicine formula composed of three herbal medicines. However, the systematic investigation on its chemical components has not been reported yet. In this study, a high-performance liquid chromatography combined with diode-array detector, and coupled to an electrospray ionization with ion-trap time-of-flight mass spectrometry (HPLC-DAD-ESI-IT-TOF-MS) method, was established for the identification of chemical profile in FBI. Sixty-six major constituents (14 phenolic acids, 14 iridoids, 20 flavonoids, 2 benzylideneacetone compounds, 3 phenylethanoid glycosides, 1 coumarin, 1 lignan, 3 nucleosides, 1 amino acids, 1 monosaccharides, 2 oligosaccharides, 3 alduronic acids and citric acid) were identified or tentatively characterized by comparing their retention times and MS spectra with those of standards or literature data. Finally, all constituents were further assigned in the individual herbs (InHs), although some of them were from multiple InHs. As a result, 11 compounds were from Lobelia chinensis Lour, 33 compounds were from Scutellaria barbata D. Don and 38 compounds were from Hedyotis diffusa Willd. In conclusion, the developed HPLC-DAD-ESI-IT-TOF-MS method is a rapid and efficient technique for analysis of FBI sample, and could be a valuable method for the further study on the quality control of the FBI.

  9. UHPLC-Q-TOF-MS-based metabolomics approach to compare the saponin compositions of Xueshuantong injection and Xuesaitong injection.

    PubMed

    Yao, Changliang; Yang, Wenzhi; Zhang, Jingxian; Qiu, Shi; Chen, Ming; Shi, Xiaojian; Pan, Huiqin; Wu, Wanying; Guo, Dean

    2017-02-01

    Various traditional Chinese medicine preparations developed from Notoginseng total saponins, including Xueshuantong injection and Xuesaitong injection, are extensively used in China to treat cardiocerebrovascular diseases. However, the difference of their saponin compositions remains unknown. An ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry based metabolomics approach was developed to probe the saponin discrimination between Xueshuantong and Xuesaitong and the related factors by large sample analysis. A highly efficient chromatographic separation was achieved on an HSS T3 column within 20 min with the holistic metabolites information recorded in the negative MS(E) mode. A six-step data pretreatment procedure mainly based on Progenesis QI and mass defect filtering was established. Pattern recognition chemometrics was used to discover the potential saponin markers. The saponin composition of Wuzhou Xueshuantong showed distinct discrimination from the other products. Wuzhou Xueshuantong contains more abundant protopanaxatriol-type noto-R1 , Rg1 , Re, and protopanaxadiol-type Rb1 , but less Rd and other low-polarity protopanaxadiol-type ginsenosides. These differences could not directly correlate to the use of different parts of Panax notoginseng, but possibly to the different preparation techniques employed by different manufacturers. These results are beneficial to the establishment of pharmacopoeia standards and the assessment of the efficacy and adverse drug reactions for these homologous products.

  10. TOF mobility measurements in pristine films of P3HT: control of hole injection and influence of film thickness

    NASA Astrophysics Data System (ADS)

    Ballantyne, Amy M.; Wilson, Joanne S.; Nelson, Jenny; Bradley, Donal D. C.; Durrant, James R.; Heeney, Martin; Duffy, Warren; McCulloch, Iain

    2006-08-01

    Time-of-flight (TOF) photocurrent measurements have been used to study charge transport in films of regioregular poly(3-hexylthiophene) (P3HT). Devices in which the P3HT film had been deposited directly onto an indium tin oxide (ITO) electrode produced high dark currents as a result of hole injection into P3HT from ITO. Photocurrent transients in such devices were disperse. It was found however, that these dark currents could be significantly reduced by inserting a dense TiO II layer between the ITO and the polymer film. The resulting devices gave non-dispersive transients with hole and electron mobilities in the range of 1 - 2 10 -4 cm2 V -1 s -1 at room temperature. The mobility values were observed to be almost independent of film thickness over the range of 350 nm to 4.3 μm. Temperature dependence studies showed a weak dependence on temperature with a low energetic disorder parameter according to analysis using the Gaussian Disorder Model (GDM) of 71 meV.

  11. Experimental investigation on nonlinear dynamics of 1550 nm VCSEL simultaneously subject to orthogonal optical injection and negative optoelectronic feedback

    NASA Astrophysics Data System (ADS)

    Deng, Tao; Xia, Guang-Qiong; Chen, Jian-Jun; Tang, Xi; Lin, Xiao-Dong; Yang, Xin; Huang, Shou-Wen; Wu, Zheng-Mao

    2017-04-01

    Nonlinear dynamic characteristics of a 1550 nm vertical-cavity surface-emitting laser (1550 nm VCSEL) simultaneously subject to orthogonal optical injection and negative optoelectronic feedback are experimentally investigated. The results show that, under suitable orthogonal optical injection the VCSEL can exhibit rich nonlinear dynamic behaviors such as stable state (S), period-one (P1), period-two (P2), chaos (CO), stable injection locking (SIL) and polarization switching (PS). After further introducing negative optoelectronic feedback with a certain feedback delay time, the dynamic distribution of the orthogonal optical injection 1550 nm VCSEL is significantly affected, and some new phenomena including three-frequency quasiperiodic (Q3) state can be observed. With the increase of optoelectronic feedback strength, the S and SIL regions typically are shrank, while the quasiperiodic (QP) and CO regions are enlarged.

  12. Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

    DOE PAGES

    Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; ...

    2015-06-24

    The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ionmore » injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.« less

  13. Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

    SciTech Connect

    Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; Moore, Ronald J.; Ibrahim, Yehia M.; Smith, Richard D.

    2015-06-24

    The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ion injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.

  14. Stability-indicating HPLC method development and structural elucidation of novel degradation products in posaconazole injection by LC-TOF/MS, LC-MS/MS and NMR.

    PubMed

    Yang, Yidi; Zhu, Xi; Zhang, Fei; Li, Wei; Wu, Ying; Ding, Li

    2016-06-05

    Stress testing was carried out under acidic, alkaline, oxidative, thermal and photolytic conditions to evaluate the intrinsic stability of posaconazole injection. A total of four degradation products were detected and the drug was found to be susceptible to oxidative and thermal degradations. Three unknown degradants formed under oxidative stress condition were isolated by preparative HPLC and unambiguously elucidated by LC-TOF/MS, LC-MS/MS, (1)H NMR, (13)C NMR and 2D NMR techniques. Based on the spectrometric and spectroscopic information, these novel degradation products were unequivocally assigned as the N-oxides of posaconazole. Probable mechanisms for the formation of the degradants were proposed. A new and selective HPLC method was developed and validated to separate, detect and quantify all the degradants in posaconazole injection.

  15. Research on the change of chemical composition in productive process of Re Du Ning injection by HPLC/Q-TOF MS.

    PubMed

    Zhang, Shan; Li, Yan-Jing; Zhang, Chun-Xiao; Huang, Wen-Zhe; Ding, Gang; Wang, Zhen-Zhong; Bi, Yu-An; Xiao, Wei

    2016-02-01

    A high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) was developed for the analysis of chemical composition change in the production process of Re Du Ning injection, a Chinese medicine preparation with a combination of Lonicera japonica Thunb., Gardenia jasminoides Ellis and Artemisia annua L. A total of 90 compounds from raw materials-intermediates-Re Du Ning injection were detected; among them, 55 compounds were identified or tentatively characterized, and the characteristic ions of different types of compounds were described. Based on these studies, the different types of compounds in the various process routes were analyzed. A total of 28 compounds, including seven iridoid glycosides and six monoterpenes from G. jasminoides Ellis, five iridoid glycosides, nine phenolic acids and one unknown compound from L. japonica Thunb., were transferred to Re Du Ning injection, and two unknown compounds were generated in the production process of Re Du Ning injection. The results indicated that the Chinese Medicine Pharmaceutical process control is very important. This method could provide some reference for other Chinese medicine preparations.

  16. Orthogonal projection (OP) technique applied to pattern recognition of fingerprints of the herbal medicine houttuynia cordata Thunb. and its final injection products.

    PubMed

    Zeng, Zhong-Da; Liang, Yi-Zeng; Zhang, Ting; Chau, Foo-Tim; Wang, Ya-Li

    2006-05-01

    It is a crucial issue to determine the origins of herbal medicinal materials and identify the quality grades and fakes of their final products collected from different pharmaceutical corporations. Pattern recognition technique may assist the manufacturers to achieve this purpose and effectively control the quality of their products. In this work, a widely used method in chemometrics, orthogonal projection (OP) technique, was applied to discrimination analysis and identification of fingerprints of the herbal medicine houttuynia cordata Thunb. (HCT) and its final injection products. The advantages of the OP technique are clearly shown after comparing with the conventional methods such as principal component analysis (PCA), Mahalanobis distance (MD), and similarity comparison method (SCM). Three different sources of medicinal material HCT and its final injection products from six different manufacturers were studied under 'sixfold', 'threefold' and 'threefold-bis' cross-validation procedures. The good performance of the proposed method in determination and identification of unknown samples shows it could be a powerful tool for quality control in herbal medicine production and other related research fields.

  17. Screening anaphylactic components of MaiLuoNing injection by using rat basophilic leukemia-2H3 cell membrane chromatography coupled with HPLC-ESI-TOF-MS.

    PubMed

    Han, Shengli; Lv, Yanni; Xue, Wenjing; Cao, Jiao; Cui, Ronghua; Zhang, Tao

    2016-02-01

    MaiLuoNing injection is a traditional Chinese medicine that used clinically since the 1950s in China. However, anaphylactic reactions, through the potentiation of mast cell degranulation, have been reported. In the present study, a rat basophilic leukemia-2H3 cell membrane chromatography coupled with high-performance liquid chromatography and electrospray ionization-ion trap-time of flight-mass spectrometry method was established for screening, analyzing, and identifying the potential anaphylactic components of MaiLuoNing injection. Harpagoside, a potential degranulator of rat basophilic leukemia-2H3 cells, was retained in rat basophilic leukemia-2H3 cell membrane chromatography. We aimed to evaluate the retained components to determine which of those were capable of inducing degranulation of basophilic leukemia cells. A β-hexosaminidase assay revealed that harpagoside can induce rat basophilic leukemia-2H3 cell degranulation in a dose-dependent manner. BLBA/c mice also exhibit passive cutaneous anaphylaxis in response to harpagoside. These results indicate that rat basophilic leukemia-2H3 cell membrane chromatography coupled with high-performance liquid chromatography and electrospray ionization ion trap time-of-flight mass spectrometry is effective in screening for the anaphylactic components of MaiLuoNing injection.

  18. PHENIX Fast TOF

    SciTech Connect

    Soha, Aria; Chiu, Mickey; Mannel, Eric; Stoll, Sean; Lynch, Don; Boose, Steve; Northacker, Dave; Alfred, Marcus; Lindesay, James; Chujo, Tatsuya; Inaba, Motoi; Nonaka, Toshihiro; Sato, Wataru; Sakatani, Ikumi; Hirano, Masahiro; Choi, Ihnjea

    2014-01-15

    This is a technical scope of work (TSW) between the Fermi National Accelerator Laboratory (Fermilab) and the experimenters of PHENIX Fast TOF group who have committed to participate in beam tests to be carried out during the FY2014 Fermilab Test Beam Facility program. The goals for this test beam experiment are to verify the timing performance of the two types of time-of-flight detector prototypes.

  19. Coherent orthogonal polynomials

    SciTech Connect

    Celeghini, E.; Olmo, M.A. del

    2013-08-15

    We discuss a fundamental characteristic of orthogonal polynomials, like the existence of a Lie algebra behind them, which can be added to their other relevant aspects. At the basis of the complete framework for orthogonal polynomials we include thus–in addition to differential equations, recurrence relations, Hilbert spaces and square integrable functions–Lie algebra theory. We start here from the square integrable functions on the open connected subset of the real line whose bases are related to orthogonal polynomials. All these one-dimensional continuous spaces allow, besides the standard uncountable basis (|x〉), for an alternative countable basis (|n〉). The matrix elements that relate these two bases are essentially the orthogonal polynomials: Hermite polynomials for the line and Laguerre and Legendre polynomials for the half-line and the line interval, respectively. Differential recurrence relations of orthogonal polynomials allow us to realize that they determine an infinite-dimensional irreducible representation of a non-compact Lie algebra, whose second order Casimir C gives rise to the second order differential equation that defines the corresponding family of orthogonal polynomials. Thus, the Weyl–Heisenberg algebra h(1) with C=0 for Hermite polynomials and su(1,1) with C=−1/4 for Laguerre and Legendre polynomials are obtained. Starting from the orthogonal polynomials the Lie algebra is extended both to the whole space of the L{sup 2} functions and to the corresponding Universal Enveloping Algebra and transformation group. Generalized coherent states from each vector in the space L{sup 2} and, in particular, generalized coherent polynomials are thus obtained. -- Highlights: •Fundamental characteristic of orthogonal polynomials (OP): existence of a Lie algebra. •Differential recurrence relations of OP determine a unitary representation of a non-compact Lie group. •2nd order Casimir originates a 2nd order differential equation that defines

  20. Multiplexed Ion Mobility Spectrometry - Orthogonal Time-Of-Flight Mass Spectrometry

    SciTech Connect

    Belov, Mikhail E.; Buschbach, Michael A.; Prior, David C.; Tang, Keqi; Smith, Richard D.

    2007-03-15

    Ion mobility spectrometry (IMS) coupled to orthogonal time-of-flight mass spectrometry (TOF) has shown significant promise for the characterization of complex biological mixtures. The enormous complexity of biological samples (e.g. from proteomics) and the need for both biological and technical analysis replicates imposes major challenges for multidimensional separation platforms in regard to both sensitivity and sample throughput. A major potential attraction of the IMS-TOF MS platform is separation speeds exceeding that of conventional condensed-phase separations by orders of magnitude. Known limitations of the IMS-TOF MS platforms that presently mitigate this attraction include the need for extensive signal averaging due to factors that include significant ion losses in the IMS-TOF interface and an ion utilization efficiency of less than ~1% with continuous ion sources (e.g. ESI). We have developed a new multiplexed ESI-IMS-TOF mass spectrometer that enables lossless ion transmission through the IMS-TOF as well as a utilization efficiency of >50% for ions from the ESI source. Initial results with a mixture of peptides show a ~10-fold increase in signal-to-noise ratio with the multiplexed approach compared to a signal averaging approach, with no reduction in either IMS or TOF MS resolution.

  1. Accelerated time-of-flight (TOF) PET image reconstruction using TOF bin subsetization and TOF weighting matrix pre-computation.

    PubMed

    Mehranian, Abolfazl; Kotasidis, Fotis; Zaidi, Habib

    2016-02-07

    Time-of-flight (TOF) positron emission tomography (PET) technology has recently regained popularity in clinical PET studies for improving image quality and lesion detectability. Using TOF information, the spatial location of annihilation events is confined to a number of image voxels along each line of response, thereby the cross-dependencies of image voxels are reduced, which in turns results in improved signal-to-noise ratio and convergence rate. In this work, we propose a novel approach to further improve the convergence of the expectation maximization (EM)-based TOF PET image reconstruction algorithm through subsetization of emission data over TOF bins as well as azimuthal bins. Given the prevalence of TOF PET, we elaborated the practical and efficient implementation of TOF PET image reconstruction through the pre-computation of TOF weighting coefficients while exploiting the same in-plane and axial symmetries used in pre-computation of geometric system matrix. In the proposed subsetization approach, TOF PET data were partitioned into a number of interleaved TOF subsets, with the aim of reducing the spatial coupling of TOF bins and therefore to improve the convergence of the standard maximum likelihood expectation maximization (MLEM) and ordered subsets EM (OSEM) algorithms. The comparison of on-the-fly and pre-computed TOF projections showed that the pre-computation of the TOF weighting coefficients can considerably reduce the computation time of TOF PET image reconstruction. The convergence rate and bias-variance performance of the proposed TOF subsetization scheme were evaluated using simulated, experimental phantom and clinical studies. Simulations demonstrated that as the number of TOF subsets is increased, the convergence rate of MLEM and OSEM algorithms is improved. It was also found that for the same computation time, the proposed subsetization gives rise to further convergence. The bias-variance analysis of the experimental NEMA phantom and a clinical

  2. Parallel Spectral Acquisition with Orthogonal ICR Cells

    NASA Astrophysics Data System (ADS)

    Park, Sung-Gun; Anderson, Gordon A.; Bruce, James E.

    2017-03-01

    FT-based high performance mass analyzers yield increased resolving power and mass measurement accuracy, yet require increased duration of signal acquisition that can limit many applications. The implementation of stronger magnetic fields, multiple detection electrodes for harmonic signal detection, and an array of multiple mass analyzers arranged along the magnetic field axis have been used to decrease required acquisition time. The results presented here show that multiple ion cyclotron resonance (ICR) mass analyzers can also be implemented orthogonal to the central magnetic field axis. The orthogonal ICR cell system presented here consisting of two cells (master and slave cells) was constructed with printed circuit boards and installed within a single superconducting magnet and vacuum system. A master cell was positioned, as is normally done with ICR cells, on the central magnetic field axis and a slave cell was located off this central axis, but directly adjacent and alongside the master cell. To achieve ion transfer between cells, ions that were initially trapped in the master cell were drifted across the magnetic field into the slave cell with application of a small DC field applied perpendicularly to the magnetic field axis. A subsequent population of ions was injected and accumulated in the master cell. Simultaneous excitation of cyclotron motion of ions in both cells was carried out; ICR signals from each cell were independently amplified and recorded in parallel. Presented here are the initial results of successful parallel spectral acquisition with this orthogonal dual ICR cell array.

  3. Parallel Spectral Acquisition with Orthogonal ICR Cells

    NASA Astrophysics Data System (ADS)

    Park, Sung-Gun; Anderson, Gordon A.; Bruce, James E.

    2017-01-01

    FT-based high performance mass analyzers yield increased resolving power and mass measurement accuracy, yet require increased duration of signal acquisition that can limit many applications. The implementation of stronger magnetic fields, multiple detection electrodes for harmonic signal detection, and an array of multiple mass analyzers arranged along the magnetic field axis have been used to decrease required acquisition time. The results presented here show that multiple ion cyclotron resonance (ICR) mass analyzers can also be implemented orthogonal to the central magnetic field axis. The orthogonal ICR cell system presented here consisting of two cells (master and slave cells) was constructed with printed circuit boards and installed within a single superconducting magnet and vacuum system. A master cell was positioned, as is normally done with ICR cells, on the central magnetic field axis and a slave cell was located off this central axis, but directly adjacent and alongside the master cell. To achieve ion transfer between cells, ions that were initially trapped in the master cell were drifted across the magnetic field into the slave cell with application of a small DC field applied perpendicularly to the magnetic field axis. A subsequent population of ions was injected and accumulated in the master cell. Simultaneous excitation of cyclotron motion of ions in both cells was carried out; ICR signals from each cell were independently amplified and recorded in parallel. Presented here are the initial results of successful parallel spectral acquisition with this orthogonal dual ICR cell array.

  4. Parallel Spectral Acquisition with Orthogonal ICR Cells.

    PubMed

    Park, Sung-Gun; Anderson, Gordon A; Bruce, James E

    2017-01-05

    FT-based high performance mass analyzers yield increased resolving power and mass measurement accuracy, yet require increased duration of signal acquisition that can limit many applications. The implementation of stronger magnetic fields, multiple detection electrodes for harmonic signal detection, and an array of multiple mass analyzers arranged along the magnetic field axis have been used to decrease required acquisition time. The results presented here show that multiple ion cyclotron resonance (ICR) mass analyzers can also be implemented orthogonal to the central magnetic field axis. The orthogonal ICR cell system presented here consisting of two cells (master and slave cells) was constructed with printed circuit boards and installed within a single superconducting magnet and vacuum system. A master cell was positioned, as is normally done with ICR cells, on the central magnetic field axis and a slave cell was located off this central axis, but directly adjacent and alongside the master cell. To achieve ion transfer between cells, ions that were initially trapped in the master cell were drifted across the magnetic field into the slave cell with application of a small DC field applied perpendicularly to the magnetic field axis. A subsequent population of ions was injected and accumulated in the master cell. Simultaneous excitation of cyclotron motion of ions in both cells was carried out; ICR signals from each cell were independently amplified and recorded in parallel. Presented here are the initial results of successful parallel spectral acquisition with this orthogonal dual ICR cell array. Graphical Abstract ᅟ.

  5. Orthogonal Regression: A Teaching Perspective

    ERIC Educational Resources Information Center

    Carr, James R.

    2012-01-01

    A well-known approach to linear least squares regression is that which involves minimizing the sum of squared orthogonal projections of data points onto the best fit line. This form of regression is known as orthogonal regression, and the linear model that it yields is known as the major axis. A similar method, reduced major axis regression, is…

  6. "Orthogonality" in Learning and Assessment

    ERIC Educational Resources Information Center

    Leslie, David

    2014-01-01

    This chapter proposes a simple framework, "orthogonality," to help clarify what stakeholders think about learning in college, how we assess outcomes, and how clear assessment methods might help increase confidence in returns on investment.

  7. Compact orthogonal NMR field sensor

    DOEpatents

    Gerald, II, Rex E.; Rathke, Jerome W.

    2009-02-03

    A Compact Orthogonal Field Sensor for emitting two orthogonal electro-magnetic fields in a common space. More particularly, a replacement inductor for existing NMR (Nuclear Magnetic Resonance) sensors to allow for NMR imaging. The Compact Orthogonal Field Sensor has a conductive coil and a central conductor electrically connected in series. The central conductor is at least partially surrounded by the coil. The coil and central conductor are electrically or electro-magnetically connected to a device having a means for producing or inducing a current through the coil and central conductor. The Compact Orthogonal Field Sensor can be used in NMR imaging applications to determine the position and the associated NMR spectrum of a sample within the electro-magnetic field of the central conductor.

  8. Orthogonal polynomials and deformed oscillators

    NASA Astrophysics Data System (ADS)

    Borzov, V. V.; Damaskinsky, E. V.

    2015-10-01

    In the example of the Fibonacci oscillator, we discuss the construction of oscillator-like systems associated with orthogonal polynomials. We also consider the question of the dimensions of the corresponding Lie algebras.

  9. Orthogonality of spherical harmonic coefficients

    NASA Technical Reports Server (NTRS)

    Mcleod, M. G.

    1980-01-01

    Orthogonality relations are obtained for the spherical harmonic coefficients of functions defined on the surface of a sphere. Following a brief discussion of the orthogonality of Fourier series coefficients, consideration is given to the values averaged over all orientations of the coordinate system of the spherical harmonic coefficients of a function defined on the surface of a sphere that can be expressed in terms of Legendre polynomials for the special case where the function is the sum of two delta functions located at two different points on the sphere, and for the case of an essentially arbitrary function. It is noted that the orthogonality relations derived have found applications in statistical studies of the geomagnetic field.

  10. Orthogonal Mapping in Two Dimensions

    NASA Astrophysics Data System (ADS)

    Duraiswami, Ramani; Prosperetti, Andrea

    1992-02-01

    A method for the generation of orthogonal boundary-fitted curvilinear coordinates for arbitrary simply- and doubly-connected domains is developed on the basis of the theory of quasi-conformal mappings of quadrilaterals and of previous work by Ryskin and Leal. The method has useful applications in orthogonal grid generation in two-dimensional and axi-symmetric domains and in the extension of rapid elliptic solvers and spectral methods to complex geometries. A new technique for the calculation of the conformal module of quadrilaterals is also presented.

  11. TOF PET offset calibration from clinical data

    NASA Astrophysics Data System (ADS)

    Werner, M. E.; Karp, J. S.

    2013-06-01

    In this paper, we present a timing calibration technique for time-of-flight positron emission tomography (TOF PET) that eliminates the need for a specialized data acquisition. By eliminating the acquisition, the process becomes fully automated, and can be performed with any clinical data set and whenever computing resources are available. It also can be applied retroactively to datasets for which a TOF offset calibration is missing or suboptimal. Since the method can use an arbitrary data set to perform a calibration prior to a TOF reconstruction, possibly of the same data set, one also can view this as reconstruction from uncalibrated data. We present a performance comparison with existing calibration techniques.

  12. Semiquantitative multielemental analysis of biological samples by a laser ionization orthogonal time-of-flight mass spectrometer.

    PubMed

    Chen, Lizhi; Lin, Lin; Yu, Quan; Yan, Xiaomei; Hang, Wei; He, Jian; Huang, Benli

    2009-07-01

    Semiquantitative multielemental analyses of biological samples (tea leaf standard, Laminaria japonica, and pig skin) were demonstrated with a newly developed laser ionization orthogonal time-of-flight mass spectrometer (LI-O-TOFMS). The sample was directly ablated and ionized with high irradiance after simple sample preparation. Relative sensitivity coefficients (RSC) were calculated and evaluated for sensitivity differences. Due to the employment of a collisional cooling device and the orthogonal geometry of the TOF system, high resolving power can be obtained, such that elemental peaks and interferential peaks with the same nominal mass can be distinguished. The detection limit of microg g(-1) levels can be commonly achieved for elemental determination.

  13. Orthogonality catastrophes in quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Merlin, R.

    2017-02-01

    The insertion of a small polarizable particle in an arbitrarily large optical cavity significantly alters the quantum-mechanical state of the electromagnetic field in that the photon ground state of the empty cavity and that of the cavity with the particle become mutually orthogonal and, thus, cannot be connected adiabatically in the infinite limit. The photon problem can be mapped exactly onto that of a many-body system of fermions, which is known to exhibit an orthogonality catastrophe when a finite-range local potential is introduced. We predict that the motion of polarizable objects inside a cavity as well as their addition and removal from the cavity, will generate a macroscopic, diverging number of low-energy photons. The significance of these results in regard to the quantum measurement problem and the dynamical Casimir effect are also discussed.

  14. Orthogonality preserving infinite dimensional quadratic stochastic operators

    SciTech Connect

    Akın, Hasan; Mukhamedov, Farrukh

    2015-09-18

    In the present paper, we consider a notion of orthogonal preserving nonlinear operators. We introduce π-Volterra quadratic operators finite and infinite dimensional settings. It is proved that any orthogonal preserving quadratic operator on finite dimensional simplex is π-Volterra quadratic operator. In infinite dimensional setting, we describe all π-Volterra operators in terms orthogonal preserving operators.

  15. Folded orthogonal frequency division multiplexing.

    PubMed

    Corcoran, Bill; Zhu, Chen; Song, Binhuang; Lowery, Arthur J

    2016-12-26

    We propose and demonstrate a new sub-carrier multiplexing scheme, utilizing orthogonal, periodic-sinc-shaped sub-carrier spectra. This 'folded' OFDM allows for multi-carrier bands to be generated with the precise, rectangular frequency definition of Nyquist WDM. We show that this scheme can be implemented with 10 GHz sub-bands, showing a 0.5-dB implementation penalty and successful transmission over 4160-km. We further investigate 40-GHz bands in an add/drop multiplexing scenario on a 50-GHz WDM grid, and show that folded OFDM can provided advantages over conventional OFDM in bandwidth-limited systems.

  16. Species identification within Acinetobacter calcoaceticus-baumannii complex using MALDI-TOF MS.

    PubMed

    Toh, Benjamin E W; Paterson, David L; Kamolvit, Witchuda; Zowawi, Hosam; Kvaskoff, David; Sidjabat, Hanna; Wailan, Alexander; Peleg, Anton Y; Huber, Charlotte A

    2015-11-01

    Acinetobacter baumannii, one of the more clinically relevant species in the Acinetobacter genus is well known to be multi-drug resistant and associated with bacteremia, urinary tract infection, pneumonia, wound infection and meningitis. However, it cannot be differentiated from closely related species such as Acinetobacter calcoaceticus, Acinetobacter pittii and Acinetobacter nosocomialis by most phenotypic tests and can only be differentiated by specific, time consuming genotypic tests with very limited use in clinical microbiological laboratories. As a result, these species are grouped into the A. calcoaceticus-A. baumannii (Acb) complex. Herein we investigated the mass spectra of 73 Acinetobacter spp., representing ten different species, using an AB SCIEX 5800 MALDI-TOF MS to differentiate members of the Acinetobacter genus, including the species of the Acb complex. RpoB gene sequencing, 16S rRNA sequencing, and gyrB multiplex PCR were also evaluated as orthogonal methods to identify the organisms used in this study. We found that whilst 16S rRNA and rpoB gene sequencing could not differentiate A. pittii or A. calcoaceticus, they can be differentiated using gyrB multiplex PCR and MALDI-TOF MS. All ten Acinetobacter species investigated could be differentiated by their MALDI-TOF mass spectra.

  17. Development of a linear ion trap/orthogonal-time-of-flight mass spectrometer for time-dependent observation of product ions by ultraviolet photodissociation of peptide ions.

    PubMed

    Kim, Tae-Young; Schwartz, Jae C; Reilly, James P

    2009-11-01

    A hybrid linear ion trap/orthogonal time-of-flight (TOF) mass spectrometer has been developed to observe time-dependent vacuum ultraviolet photodissociation product ions. In this apparatus, a reflectron TOF mass analyzer is orthogonally interfaced to an LTQ using rf-only octopole and dc quadrupole ion guides. Precursor ions are generated by electrospray ionization and isolated in the ion trap. Subsequently they are directed to the TOF source where photodissociation occurs and product ions are extracted for mass analysis. To detect photodissociation product ions having axially divergent trajectories, a large rectangular detector is utilized. With variation of the time between photodissociation and orthogonal extraction in the TOF source, product ions formed over a range of times after photoexcitation can be sampled. Time-dependent observation of product ions following 157 nm photodissociation of a singly charged tryptic peptide ion (NWDAGFGR) showed that prompt photofragment ions (x- and v-type ions) dominate the tandem mass spectrum up to 1 micros after the laser shot, but the intensities of low energy thermal fragment ions (y-type ions) become comparable several microseconds later. Different proton mobilization time scales were observed for arginine- and lysine-terminated tryptic peptides.

  18. Nonambipolarity, orthogonal conductivity, poloidal flow, and torque

    SciTech Connect

    Hulbert, G.W.; Perkins, F.W.

    1989-02-01

    Nonambipolar processes, such as neutral injection onto trapped orbits or ripple-diffusion loss of ..cap alpha..-particles, act to charge a plasma. A current j/sub r/ across magnetic surfaces must arise in the bulk plasma to maintain charge neutrality. An axisymmetric, neoclassical model of the bulk plasma shows that these currents are carried by the ions and exert a j/sub r/B/sub theta/R/c torque in the toroidal direction. A driven poloidal flow V/sub theta/ = E/sub r/'c/B must also develop. The average current density is related to the radial electric field E/sub r/' = E/sub r/ + v/sub /phi//B/sub theta//c in a frame moving with the plasma via the orthogonal conductivity = sigma/sub /perpendicular//E/sub r/', which has the value sigma/sub /perpendicular// = (1.65epsilon/sup 1/2/)(ne/sup 2/..nu../sub ii//M..cap omega../sub theta//sup 2/) in the banana regime. If an ignited plasma loses an appreciable fraction ..delta.. of its thermonuclear ..cap alpha..-particles by banana ripple diffusion, then the torque will spin the plasma to sonic rotation in a time /tau//sub s/ approx. 2/tau//sub E//..delta.., /tau//sub E/ being the energy confinement time. 10 refs., 1 fig.

  19. Fragmentation of multiply-charged intact protein ions using MALDI TOF-TOF mass spectrometry.

    PubMed

    Liu, Zhaoyang; Schey, Kevin L

    2008-02-01

    Top down proteomics in a TOF-TOF instrument was further explored by examining the fragmentation of multiply charged precursors ions generated by matrix-assisted laser desorption ionization. Evaluation of sample preparation conditions allowed selection of solvent/matrix conditions and sample deposition methods to produce sufficiently abundant doubly and triply charged precursor ions for subsequent CID experiments. As previously reported, preferential cleavage was observed at sites C-terminal to acidic residues and N-terminal to proline residues for all ions examined. An increase in nonpreferential fragmentation as well as additional low mass product ions was observed in the spectra from multiply charged precursor ions providing increased sequence coverage. This enhanced fragmentation from multiply charged precursor ions became increasingly important with increasing protein molecular weight and facilitates protein identification using database searching algorithms. The useable mass range for MALDI TOF-TOF analysis of intact proteins has been expanded to 18.2 kDa using this approach.

  20. Rapid Detection & Identification of Bacillus Species using MALDI-TOF/TOF and Biomarker Database

    DTIC Science & Technology

    2006-06-01

    Identification of Selected Bacillus Species (excerpt from [42]) S0 0 00 two IL - ZZO al 0 > W Z 0 . 0j~ COLN SPECIESIL B. megaterium v + + + v + + - v...identification for genus (eg. Bacillus vs. Escherichia) and species ( Bacillus anthracis vs. Bacillus megaterium ), but not strains (B. anthracis Ames... Bacillus Species using MALDI-TOF/TOF and Biomarker Database A Strategic Plan Nora W.C. Chan and William E. Lee Defence R&D Canada - Suffield Zoltan Mester

  1. Structural Analysis of Triacylglycerols by Using a MALDI-TOF/TOF System with Monoisotopic Precursor Selection

    NASA Astrophysics Data System (ADS)

    Kubo, Ayumi; Satoh, Takaya; Itoh, Yoshiyuki; Hashimoto, Masahiro; Tamura, Jun; Cody, Robert B.

    2013-05-01

    A new MALDI-TOF/TOF system with monoisotopic precursor selection was applied to the analysis of triacylglycerols in an olive oil sample. Monoisotopic precursor selection made it possible to obtain product-ion mass spectra without interference from species that differed by a single double bond. Complete structure determination of all triacylglycerols, including structural isomers, was made possible by interpreting the charge-remote fragmentation resulting from high-energy collision-induced dissociation (CID) of the sodiated triacylglycerols.

  2. Numerical analysis of the orthogonal descent method

    SciTech Connect

    Shokov, V.A.; Shchepakin, M.B.

    1994-11-01

    The author of the orthogonal descent method has been testing it since 1977. The results of these tests have only strengthened the need for further analysis and development of orthogonal descent algorithms for various classes of convex programming problems. Systematic testing of orthogonal descent algorithms and comparison of test results with other nondifferentiable optimization methods was conducted at TsEMI RAN in 1991-1992 using the results.

  3. Topochemical Analysis of Cell Wall Components by TOF-SIMS.

    PubMed

    Aoki, Dan; Fukushima, Kazuhiko

    2017-01-01

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a recently developing analytical tool and a type of imaging mass spectrometry. TOF-SIMS provides mass spectral information with a lateral resolution on the order of submicrons, with widespread applicability. Sometimes, it is described as a surface analysis method without the requirement for sample pretreatment; however, several points need to be taken into account for the complete utilization of the capabilities of TOF-SIMS. In this chapter, we introduce methods for TOF-SIMS sample treatments, as well as basic knowledge of wood samples TOF-SIMS spectral and image data analysis.

  4. Orthogonal separations: Comparison of orthogonality metrics by statistical analysis.

    PubMed

    Schure, Mark R; Davis, Joe M

    2015-10-02

    Twenty orthogonality metrics (OMs) derived from convex hull, information theory, fractal dimension, correlation coefficients, nearest neighbor distances and bin-density techniques were calculated from a diverse group of 47 experimental two-dimensional (2D) chromatograms. These chromatograms comprise two datasets; one dataset is a collection of 2D chromatograms from Peter Carr's laboratory at the University of Minnesota, and the other dataset is based on pairs of one-dimensional chromatograms previously published by Martin Gilar and coworkers (Waters Corp.). The chromatograms were pooled to make a third or combined dataset. Cross-correlation results suggest that specific OMs are correlated within families of nearest neighbor methods, correlation coefficients and the information theory methods. Principal component analysis of the OMs show that none of the OMs stands out as clearly better at explaining the data variance than any another OM. Principal component analysis of individual chromatograms shows that different OMs favor certain chromatograms. The chromatograms exhibit a range of quality, as subjectively graded by nine experts experienced in 2D chromatography. The subjective (grading) evaluations were taken at two intervals per expert and demonstrated excellent consistency for each expert. Excellent agreement for both very good and very bad chromatograms was seen across the range of experts. However, evaluation uncertainty increased for chromatograms that were judged as average to mediocre. The grades were converted to numbers (percentages) for numerical computations. The percentages were correlated with OMs to establish good OMs for evaluating the quality of 2D chromatograms. Certain metrics correlate better than others. However, these results are not consistent across all chromatograms examined. Most of the nearest neighbor methods were observed to correlate poorly with the percentages. However, one method, devised by Clark and Evans, appeared to work

  5. MAP reconstruction for Fourier rebinned TOF-PET data.

    PubMed

    Bai, Bing; Lin, Yanguang; Zhu, Wentao; Ren, Ran; Li, Quanzheng; Dahlbom, Magnus; DiFilippo, Frank; Leahy, Richard M

    2014-02-21

    Time-of-flight (TOF) information improves the signal-to-noise ratio in positron emission tomography (PET). The computation cost in processing TOF-PET sinograms is substantially higher than for nonTOF data because the data in each line of response is divided among multiple TOF bins. This additional cost has motivated research into methods for rebinning TOF data into lower dimensional representations that exploit redundancies inherent in TOF data. We have previously developed approximate Fourier methods that rebin TOF data into either three-dimensional (3D) nonTOF or 2D nonTOF formats. We refer to these methods respectively as FORET-3D and FORET-2D. Here we describe maximum a posteriori (MAP) estimators for use with FORET rebinned data. We first derive approximate expressions for the variance of the rebinned data. We then use these results to rescale the data so that the variance and mean are approximately equal allowing us to use the Poisson likelihood model for MAP reconstruction. MAP reconstruction from these rebinned data uses a system matrix in which the detector response model accounts for the effects of rebinning. Using these methods we compare the performance of FORET-2D and 3D with TOF and nonTOF reconstructions using phantom and clinical data. Our phantom results show a small loss in contrast recovery at matched noise levels using FORET compared to reconstruction from the original TOF data. Clinical examples show FORET images that are qualitatively similar to those obtained from the original TOF-PET data but with a small increase in variance at matched resolution. Reconstruction time is reduced by a factor of 5 and 30 using FORET3D+MAP and FORET2D+MAP respectively compared to 3D TOF MAP, which makes these methods attractive for clinical applications.

  6. Cherenkov TOF PET with silicon photomultipliers

    NASA Astrophysics Data System (ADS)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2015-12-01

    As previously demonstrated, an excellent timing resolution below 100 ps FWHM is possible in time-of-flight positron emission tomography (TOF PET) if the detection method is based on the principle of detecting photons of Cherenkov light, produced in a suitable material and detected by microchannel plate photomultipliers (MCP PMTs). In this work, the silicon photomultipliers (SiPMs) were tested for the first time as the photodetectors in Cherenkov TOF PET. The high photon detection efficiency (PDE) of SiPMs led to a large improvement in detection efficiency. On the other hand, the time response of currently available SiPMs is not as good as that of MCP PMTs. The SiPM dark counts introduce a new source of random coincidences in Cherenkov method, which would be overwhelming with present SiPM technology at room temperature. When the apparatus was cooled, its performance significantly improved.

  7. Astrophysics at n_TOF Facility

    NASA Astrophysics Data System (ADS)

    Tagliente, G.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Heil, M.; Herrera-Martinez, A.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Kossionides, E.; Krtička, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Pancin, J.; Papachristodoulou, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K.

    2010-08-01

    Heavy elements with Z>=30 are made by neutron capture reactions during stellar He burning and presumably in supernovae. This contribution deals mainly with the slow neutron capture (s) process which is responsible for about one half of the abundances in the mass region between Fe and Bi. The slow time scale implies that the reaction path of this process involves mostly stable isotopes which can be studied in detail in laboratory experiments. The neutron time of flight (n_TOF) facility at CERN is a neutron spallation source, its white neutron energy spectrum ranges from thermal to several MeV, covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross section required in s-process nucleosynthesis. This contribution gives an overview on the astrophysical program made at n_TOF facility, the results and the implications will be considered.

  8. Dose Optimization in TOF-PET/MR Compared to TOF-PET/CT

    PubMed Central

    Queiroz, Marcelo A.; Delso, Gaspar; Wollenweber, Scott; Deller, Timothy; Zeimpekis, Konstantinos; Huellner, Martin; de Galiza Barbosa, Felipe; von Schulthess, Gustav; Veit-Haibach, Patrick

    2015-01-01

    Purpose To evaluate the possible activity reduction in FDG-imaging in a Time-of-Flight (TOF) PET/MR, based on cross-evaluation of patient-based NECR (noise equivalent count rate) measurements in PET/CT, cross referencing with phantom-based NECR curves as well as initial evaluation of TOF-PET/MR with reduced activity. Materials and Methods A total of 75 consecutive patients were evaluated in this study. PET/CT imaging was performed on a PET/CT (time-of-flight (TOF) Discovery D 690 PET/CT). Initial PET/MR imaging was performed on a newly available simultaneous TOF-PET/MR (Signa PET/MR). An optimal NECR for diagnostic purposes was defined in clinical patients (NECRP) in PET/CT. Subsequent optimal activity concentration at the acquisition time ([A]0) and target NECR (NECRT) were obtained. These data were used to predict the theoretical FDG activity requirement of the new TOF-PET/MR system. Twenty-five initial patients were acquired with (retrospectively reconstructed) different imaging times equivalent for different activities on the simultaneous PET/MR for the evaluation of clinically realistic FDG-activities. Results The obtained values for NECRP, [A]0 and NECRT were 114.6 (± 14.2) kcps (Kilocounts per second), 4.0 (± 0.7) kBq/mL and 45 kcps, respectively. Evaluating the NECRT together with the phantom curve of the TOF-PET/MR device, the theoretical optimal activity concentration was found to be approximately 1.3 kBq/mL, which represents 35% of the activity concentration required by the TOF-PET/CT. Initial evaluation on patients in the simultaneous TOF-PET/MR shows clinically realistic activities of 1.8 kBq/mL, which represent 44% of the required activity. Conclusion The new TOF-PET/MR device requires significantly less activity to generate PET-images with good-to-excellent image quality, due to improvements in detector geometry and detector technologies. The theoretically achievable dose reduction accounts for up to 65% but cannot be fully translated into clinical

  9. New identification of proanthocyanidins in cinnamon (Cinnamomum zeylanicum L.) using MALDI-TOF/TOF mass spectrometry.

    PubMed

    Mateos-Martín, María Luisa; Fuguet, Elisabet; Quero, Carmen; Pérez-Jiménez, Jara; Torres, Josep Lluís

    2012-01-01

    The inner bark of Ceylon cinnamon (Cinnamomum zeylanicum L.) is commonly used as a spice and has also been widely employed in the treatment and prevention of disease. The positive health effects associated with the consumption of cinnamon could in part be due to its phenolic composition; proanthocyanidins (PA) are the major polyphenolic component in commercial cinnamon. We present a thorough study of the PA profile of cinnamon obtained using matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. In addition to the advantages of MALDI-TOF as a sensitive technique for the analysis of high-molecular-weight compounds, the tandem arrangement allows the identification of the compounds through their fragmentation patterns from MS/MS experiments. This is the first time that this technique has been used to analyze polymeric PA. The results show that cinnamon PA are more complex than was previously thought. We show here for the first time that they contain (epi)gallocatechin and (epi)catechingallate units. As gallates (galloyl moieties) and the pyrogallol group in gallocatechins have been related to the biological activity of grape and tea polyphenols, the presence of these substructures may explain some of the properties of cinnamon extracts. MALDI-TOF/TOF reveals that cinnamon bark PA include combinations of (epi)catechin, (epi)catechingallate, (epi)gallocatechin, and (epi)afzelechin, which results in a highly heterogeneous mixture of procyanidins, prodelphinidins, and propelargonidins.

  10. Which are more accurate, orthogonal or non-orthogonal sonic anemometers?

    NASA Astrophysics Data System (ADS)

    Massman, W. J.; Frank, J. M.; Swiatek, E.; Zimmerman, H.; Ewers, B. E.

    2013-12-01

    Sonic anemometry is fundamental to all eddy-covariance studies of surface energy, ecosystem carbon, and water balance. Recent studies have shown the potential underestimation of the vertical wind fluctuations among the most commonly encountered anemometer models, but thus far testing has been focused on non-orthogonal sonic anemometer designs. We hypothesize that these underestimates are systematic to the non-orthogonal design and not attributable to a single manufacturer. If so, orthogonal measurements of vertical wind should be more accurate. We tested this by conducting an experiment to measure the relative consistency between vertical and horizontal wind measurements for three sonic anemometer designs: orthogonal, non-orthogonal, and quasi-orthogonal. Both the orthogonal and non-orthogonal models were from a single manufacturer (K-probe and A-probe, Applied Technologies, Inc.) while the quasi-orthogonal design featured non-orthogonal u- and v-axes but with an orthogonal w-axis (CSAT3V, Campbell Scientific, Inc.). We conducted a 12-week experiment, testing four sonic anemometers relative to a control (CSAT3, Campbell Scientific, Inc.), each week randomly selecting at least one of each model from a pool of twelve instruments (three of each model) and randomly locating the test anemometers around the control. Half-way through the week the test anemometers were re-mounted in a horizontal position. Work was done at the GLEES AmeriFlux site (southeastern Wyoming, USA) which experiences large, uni-directional wind and turbulence. Results are discussed.

  11. Analysis of Combustion Chamber Deposits by ESI-TOF-MS and MALDI-TOF-MS

    SciTech Connect

    Reynolds, J G; Shields, S J; Roos, J W

    2001-06-14

    Combustion chamber deposits (CCDs) in internal combustion engines have been studied by various techniques to understand the relationship of performance degradation with deposit quantity and structure. XPS, XAS, NMR, and elemental analysis have offered insight into the bulk structure of C, H, N, O and metal components [1]. MS has offered some information about compound structure, but results are limited due to the insolubility and complexity of the materials. Recent advances in MS have opened new possibilities for analysis of CCDs. Here we report initial findings on the carbon structure of these deposits determined by ESI-TOF-MS and MADLI-TOF-MS.

  12. On orthogonality preserving quadratic stochastic operators

    SciTech Connect

    Mukhamedov, Farrukh; Taha, Muhammad Hafizuddin Mohd

    2015-05-15

    A quadratic stochastic operator (in short QSO) is usually used to present the time evolution of differing species in biology. Some quadratic stochastic operators have been studied by Lotka and Volterra. In the present paper, we first give a simple characterization of Volterra QSO in terms of absolutely continuity of discrete measures. Further, we introduce a notion of orthogonal preserving QSO, and describe such kind of operators defined on two dimensional simplex. It turns out that orthogonal preserving QSOs are permutations of Volterra QSO. The associativity of genetic algebras generated by orthogonal preserving QSO is studied too.

  13. Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework

    NASA Astrophysics Data System (ADS)

    Matej, Samuel; Daube-Witherspoon, Margaret E.; Karp, Joel S.

    2016-05-01

    Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of time-of-flight (TOF) scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (DIRECT: direct image reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias versus variance performance to iterative TOF reconstruction with a matched resolution model.

  14. Analytic TOF PET reconstruction algorithm within DIRECT data partitioning framework.

    PubMed

    Matej, Samuel; Daube-Witherspoon, Margaret E; Karp, Joel S

    2016-05-07

    Iterative reconstruction algorithms are routinely used for clinical practice; however, analytic algorithms are relevant candidates for quantitative research studies due to their linear behavior. While iterative algorithms also benefit from the inclusion of accurate data and noise models the widespread use of time-of-flight (TOF) scanners with less sensitivity to noise and data imperfections make analytic algorithms even more promising. In our previous work we have developed a novel iterative reconstruction approach (DIRECT: direct image reconstruction for TOF) providing convenient TOF data partitioning framework and leading to very efficient reconstructions. In this work we have expanded DIRECT to include an analytic TOF algorithm with confidence weighting incorporating models of both TOF and spatial resolution kernels. Feasibility studies using simulated and measured data demonstrate that analytic-DIRECT with appropriate resolution and regularization filters is able to provide matched bias versus variance performance to iterative TOF reconstruction with a matched resolution model.

  15. Quantitative differences in [(18)F] NaF PET/CT: TOF versus non-TOF measurements.

    PubMed

    Oldan, Jorge D; Turkington, Timothy G; Choudhury, Kingshuk; Chin, Bennett B

    2015-01-01

    [(18)F] sodium fluoride (NaF) PET/CT is a current, clinically relevant method to assess bone metastases. Time-of-flight (TOF) PET provides better statistical data quality, which can improve either lower image noise or improve resolution, or both, depending on the image reconstruction. Improved resolution can improve quantitative measurements of standardized uptake value (SUV) in small structures. These quantitative differences may be important in both clinical interpretation and multicenter clinical trials where quantification is integral to assessing response to therapy. The purpose of this study is to determine if and by how much SUV quantitatively differs between TOF and conventional non-TOF reconstructions in [(18)F] NaF PET/CT. SUV measurements (mean and maximum) were compared in TOF and non-TOF [(18)F] NaF PET-CT reconstructions for 47 prostate cancer patients in normal regions including: soft tissue (n=282 total regions; liver, aorta, posterior abdominal fat, bladder, brain, and paraspinal muscles), and osseous structures (n=188; T12 vertebral body, femoral diaphyseal cortex, femoral head, and lateral rib). Comparisons were also made for benign degenerative changes (n=281) and metastases (n=159). TOF and non-TOF SUVs were assessed with paired t-test and linear correlations. Normal soft tissue showed lower SUVmean for TOF compared to non-TOF in liver, brain, and adipose. All osseous structures showed higher SUVmean for TOF compared to non-TOF including normal regions, degenerative joint disease, and metastases. For all metastatic lesions, the average SUVmean increased by 2.5%, and in degenerative joint disease it increased by 3.5% on TOF reconstructions. Smaller lesion size was a significant factor influencing this increase in SUVmean. TOF SUVmean values are higher in osseous structures and lower in background soft tissue structures. While these differences are statistically significant, the magnitudes of these changes are relatively modest. Smaller osseous

  16. Gaussian quadrature for multiple orthogonal polynomials

    NASA Astrophysics Data System (ADS)

    Coussement, Jonathan; van Assche, Walter

    2005-06-01

    We study multiple orthogonal polynomials of type I and type II, which have orthogonality conditions with respect to r measures. These polynomials are connected by their recurrence relation of order r+1. First we show a relation with the eigenvalue problem of a banded lower Hessenberg matrix Ln, containing the recurrence coefficients. As a consequence, we easily find that the multiple orthogonal polynomials of type I and type II satisfy a generalized Christoffel-Darboux identity. Furthermore, we explain the notion of multiple Gaussian quadrature (for proper multi-indices), which is an extension of the theory of Gaussian quadrature for orthogonal polynomials and was introduced by Borges. In particular, we show that the quadrature points and quadrature weights can be expressed in terms of the eigenvalue problem of Ln.

  17. PTR-QMS versus PTR-TOF comparison in a region with oil and natural gas extraction industry in the Uintah Basin in 2013

    NASA Astrophysics Data System (ADS)

    Warneke, C.; Veres, P.; Murphy, S. M.; Soltis, J.; Field, R. A.; Graus, M. G.; Koss, A.; Li, S.-M.; Li, R.; Yuan, B.; Roberts, J. M.; de Gouw, J. A.

    2015-01-01

    Here we compare volatile organic compound (VOC) measurements using a standard proton-transfer-reaction quadrupole mass spectrometer (PTR-QMS) with a new proton-transfer-reaction time of flight mass spectrometer (PTR-TOF) during the Uintah Basin Winter Ozone Study 2013 (UBWOS2013) field experiment in an oil and gas field in the Uintah Basin, Utah. The PTR-QMS uses a quadrupole, which is a mass filter that lets one mass to charge ratio pass at a time, whereas the PTR-TOF uses a time of flight mass spectrometer, which takes full mass spectra with typical 0.1 s-1 min integrated acquisition times. The sensitivity of the PTR-QMS in units of counts per ppbv (parts per billion by volume) is about a factor of 10-35 times larger than the PTR-TOF, when only one VOC is measured. The sensitivity of the PTR-TOF is mass dependent because of the mass discrimination caused by the sampling duty cycle in the orthogonal-acceleration region of the TOF. For example, the PTR-QMS on mass 33 (methanol) is 35 times more sensitive than the PTR-TOF and for masses above 120 amu less than 10 times more. If more than 10-35 compounds are measured with PTR-QMS, the sampling time per ion decreases and the PTR-TOF has higher signals per unit measuring time for most masses. For UBWOS2013 the PTR-QMS measured 34 masses in 37 s and on that timescale the PTR-TOF is more sensitive for all masses. The high mass resolution of the TOF allows for the measurements of compounds that cannot be separately detected with the PTR-QMS, such as oxidation products from alkanes and cycloalkanes emitted by oil and gas extraction. PTR-TOF masses do not have to be preselected, allowing for identification of unanticipated compounds. The measured mixing ratios of the two instruments agreed very well (R2 ≥ 0.92 and within 20%) for all compounds and masses monitored with the PTR-QMS.

  18. Cabazitaxel Injection

    MedlinePlus

    ... injection is used along with prednisone to treat prostate cancer (cancer of a male reproductive organ) that has ... cabazitaxel injection is usually used in men with prostate cancer. If used by pregnant women, cabazitaxel injection can ...

  19. Fondaparinux Injection

    MedlinePlus

    ... fondaparinux injection.Talk to your doctor about the risk of using fondaparinux injection. ... Fondaparinux injection is used to prevent deep vein thrombosis (DVT; a blood ... Xa inhibitors. It works by decreasing the clotting ability of the blood.

  20. Morphine Injection

    MedlinePlus

    Morphine injection is used to relieve moderate to severe pain. Morphine is in a class of medications called opiate ( ... Morphine injection comes as a solution (liquid) to inject intramuscularly (into a muscle) or intravenously (into a ...

  1. Dexamethasone Injection

    MedlinePlus

    Dexamethasone injection is used to treat severe allergic reactions. It is used in the management of certain types of ... gastrointestinal disease, and certain types of arthritis. Dexamethasone injection is also used for diagnostic testing. Dexamethasone injection ...

  2. Romidepsin Injection

    MedlinePlus

    Romidepsin injection is used to treat cutaneous T-cell lymphoma (CTCL; a group of cancers of the immune system ... one other medication given by mouth or by injection. Romidepsin injection is in a class of medications ...

  3. Ondansetron Injection

    MedlinePlus

    Zofran® Injection ... Ondansetron injection is used to prevent nausea and vomiting caused by cancer chemotherapy and surgery. Ondansetron is in a ... medications: or any of the ingredients in ondansetron injection. Ask your pharmacist for a list of the ...

  4. TOF-SIMS analysis of polymers

    NASA Astrophysics Data System (ADS)

    Wien, Karl

    1997-08-01

    When solid polymers are irradiated with heavy ions, atomic and molecular particles are ejected from the uppermost layers of the surface. A technique to determine the mass spectrum of the charged fraction of these particles is time-of-flight secondary-ion-mass spectrometry, TOF-SIMS. The present article describes, how the mass spectra measured with polymers are generally structured and under which conditions the various types of secondary ions like cationized oligomers, fragment ions and "fingerprint" ions are observable. The mechanisms leading to formation and ejection of the ions are not well understood. At bombarding energies of 10 keV, they are mainly based on atomic collision processes, at 100 MeV on the electronic excitation of the solid in the vicinity of the nuclear track. Processes, which are capable to desorb large organic molecules, seem not to work with oligomers of similar mass. Mass spectrometry of "real world" polymers, i.e. thick samples, depends mostly on the low-mass fingerprint spectrum, which can be produced by keV MeV SIMS. Modern TOF-SIMS instruments are equipped with a pulsed ion gun and an energy focussing ion mirror. They provide high mass resolution ( {m}/{Δm} ⋍ 10000 ) and high transmission (20-50%). Examples of applications are given, like the determination of mean molecular weights or investigations of radiation induced modifications of polymers.

  5. Triacylglycerol profile in cocoa liquors using MALDI-TOF and LC-ESI tandem mass spectrometry.

    PubMed

    Bono, Luca; Seraglia, Roberta; Roverso, Marco; Di Carro, Marina; Magi, Emanuele

    2014-09-01

    Triacylglycerols are responsible for chocolate's peculiar melting behavior: the type and position of fatty acids on the glycerol molecule strongly affect the melting range of cocoa butter. For this reason, the characterization of triglyceride composition in cocoa products is particularly important. In this work, triacylglycerols extracted from cocoa liquor samples were analyzed by matrix-assisted laser desorption/ionization time-of-flight (TOF) and electrospray ionization tandem mass spectrometry (MS/MS) coupled to liquid chromatography. Extracted samples were initially analyzed by direct injection in MS to obtain information on triglyceride molecular weights; relevant MS parameters were optimized, and the possible formation of the adducts [M + Na](+) and [M + NH(4)](+) was studied. Tandem mass experiments (both with triple quadrupole and TOF/TOF) were performed to study the fragmentation pathways (in particular, the loss of palmitic, stearic and oleic acid) and identify the triacylglycerols in cocoa liquors. Some signals of the spectra obtained with both MS techniques could indicate the presence of diacylglycerols in the cocoa extract, but different experimental evidences demonstrated that they were generated by the in-source fragmentation of triglycerides. A nonaqueous reversed-phase chromatographic separation was also developed and used to support the identification of the analytes; nine triacylglycerols were recognized in the cocoa liquor extracts. The three different batches of Ecuador cocoa liquor did not show significant differences in the triacylglycerol profile.

  6. Ibandronate Injection

    MedlinePlus

    Boniva® Injection ... Ibandronate injection is used to treat osteoporosis (a condition in which the bones become thin and weak and break ... Ibandronate injection comes as a solution (liquid) to be injected into a vein by a doctor or nurse in ...

  7. Leuprolide Injection

    MedlinePlus

    Leuprolide injection comes as a long-acting suspension (Lupron) that is injected intramuscularly (into a muscle) by a doctor or nurse in a medical ... Depot-4 month, Lupron Depot-6 Month). Leuprolide injection also comes as a long-acting suspension (Eligard) that is injected subcutaneously (just under ...

  8. Face hallucination using orthogonal canonical correlation analysis

    NASA Astrophysics Data System (ADS)

    Zhou, Huiling; Lam, Kin-Man

    2016-05-01

    A two-step face-hallucination framework is proposed to reconstruct a high-resolution (HR) version of a face from an input low-resolution (LR) face, based on learning from LR-HR example face pairs using orthogonal canonical correlation analysis (orthogonal CCA) and linear mapping. In the proposed algorithm, face images are first represented using principal component analysis (PCA). Canonical correlation analysis (CCA) with the orthogonality property is then employed, to maximize the correlation between the PCA coefficients of the LR and the HR face pairs to improve the hallucination performance. The original CCA does not own the orthogonality property, which is crucial for information reconstruction. We propose using orthogonal CCA, which is proven by experiments to achieve a better performance in terms of global face reconstruction. In addition, in the residual-compensation process, a linear-mapping method is proposed to include both the inter- and intrainformation about manifolds of different resolutions. Compared with other state-of-the-art approaches, the proposed framework can achieve a comparable, or even better, performance in terms of global face reconstruction and the visual quality of face hallucination. Experiments on images with various parameter settings and blurring distortions show that the proposed approach is robust and has great potential for real-world applications.

  9. Haunted Quantum Entanglement, Quantum Erasure, and Orthogonality

    NASA Astrophysics Data System (ADS)

    Snyder, Douglas

    2010-02-01

    Both haunted quantum entanglement (hqe) and quantum erasure (qe) demonstrate interference. For interference, overlapping waves are needed which are likely supplied by equations such as 1/√ 2 [\\vert P/u>+\\vert P/l>] = \\vert P/s> and 1/√ 2 [\\vert P/u>-\\vert P/l>] = \\vert P/a> where \\vert P/u> and \\vert P/l> are generally considered orthogonal (i.e., no overlap) and \\vert P/s> and \\vert P/a> are symmetric and anti-symmetric wave functions. The conventional consideration of orthogonality in hqe and qe may need adjustment given empirical support for the presence of fringes and anti-fringes in qe. Orthogonality as regards hqe and qe is tied to the possibility of obtaining which way information. If this possibility is lost, it would appear that orthogonality which is based on this possibility may be lost. A completed measurement appears central to establishing orthogonality as regards hqe and qe. In hqe, this completed measurement could be for example an atom passing through a double slit arrangement after having emitted a photon in one of two micromaser cavities, thus providing general which way information without specifying through which specific slit the atom passed. In qe, the completed measurement could be this atom subsequently striking a detection screen, providing the ability to obtain information regarding through which specific slit the atom passed. Hqe and qe occur when which way information is lost before their respective completed measurements are made. )

  10. Investigating the microstructure of keratin extracted from wool: peptide sequence (MALDI-TOF/TOF) and protein conformation (FTIR)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Keratin was extracted from wool by reduction with 2-mercaptoethanol. It was isolated as intact keratin and characterized by its similar molecular weight, protein composition, and secondary structure to native keratin. Gel electrophoresis patterns and MALDI-TOF/TOF peptide sequences provided the ide...

  11. Thermotriggered Catalyst-Free Modification of a Glass Surface with an Orthogonal Agent Possessing Nitrile N-Oxide and Masked Ketene Functions.

    PubMed

    Cheawchan, Sumitra; Uchida, Satoshi; Sogawa, Hiromitsu; Koyama, Yasuhito; Takata, Toshikazu

    2016-01-12

    The thermotriggered modification of surfaces was performed under catalyst-free conditions using an orthogonal agent possessing both nitrile N-oxide and Meldrum's acid moieties. The nitrile N-oxide moiety of the orthogonal agent successfully underwent catalyst-free 1,3-dipolar cycloaddition to unsaturated bonds of glass surfaces to produce Meldrum's acid-functionalized surfaces. The subsequent thermal decomposition of Meldrum's acid moiety in the presence of nucleophiles afforded versatile nucleophile-modified surfaces (e.g., wet, waterproof, and photoactive surfaces). Surface characteristics were investigated with the water contact angle, time-of-flight secondary ion mass spectrometry (TOF-SIMS), and X-ray photoelectron spectroscopy (XPS). In addition, the surface modification of silica nanoparticles using the orthogonal agent was also achieved to evaluate the density of the functional group concentration on the surface.

  12. MALDI-TOF and cluster-TOF-SIMS imaging of Fabry disease biomarkers

    NASA Astrophysics Data System (ADS)

    Touboul, David; Roy, Sandrine; Germain, Dominique P.; Chaminade, Pierre; Brunelle, Alain; Laprevote, Olivier

    2007-02-01

    Fabry disease is an X-linked disorder of glycosphingolipid metabolism, in which a partial or total deficiency of [alpha]-galactosidase A, a lysosomal enzyme, results in the progressive accumulation of neutral glycosphingolipids (globotriaosylceramide and digalactosylceramide) in most fluids and tissues of the body. Few information is available about the composition and distribution in tissues of the accumulated glycosphingolipids species. Mass spectrometry imaging is an innovative technique, which can provide pieces of information about the distribution of numerous biological compounds, such as lipids, directly on the tissue sections. MALDI-TOF and cluster-TOF-SIMS imaging approaches were used to study the localization of lipids (cholesterol, cholesterol sulfate, vitamin E, glycosphingolipids ...) on skin and kidney sections of patients affected by the Fabry disease. Numerous information on pathophysiology were enlightened by both techniques.

  13. Orthogonal grid generation in two dimensional space

    NASA Astrophysics Data System (ADS)

    Theodoropoulos, T.; Bergeles, G.; Athanassiadis, N.

    A generalization of a numerical technique for orthogonal mapping, used by Ryskin and Leal (1983) for the construction of boundary-fitted curvilinear coordinate systems in two-dimensional space, is proposed. The boundary-fitted orthogonal curvilinear coordinates are assumed to transform to Cartesian coordinates by Laplace equations. The scale factors involved in the Laplace equations are computed on boundaries and estimated on internal points by means of an interpolation formula. Three types of boundary conditions have been tested: Dirichlet, Cauchy-Riemann, and pseudo-Dirichlet. It is shown that, using this method, grids appropriate for the calculation of flow fields over sharp edges, complex boundary shapes, etc., can be easily constructed. Examples on various geometries are presented, together with a convenient method to check the orthogonality of the resulting meshes.

  14. Phase array calibration orthogonal phase sequence

    NASA Technical Reports Server (NTRS)

    Sorace, Ronald E. (Inventor); Reinhardt, Victor S. (Inventor); Chan, Clinton (Inventor)

    1999-01-01

    Methods and systems for calibrating an array antenna are described. The array antenna has a plurality of antenna elements each having a signal with a phase and an amplitude forming an array antenna signal. For calibration, the phase of each element signal is sequentially switched one at a time through four orthogonal phase states. At each orthogonal phase state, the power of the array antenna signal is measured. A phase and an amplitude error for each of the element signals is determined based on the power of the array antenna signal at each of the four orthogonal phase states. The phase and amplitude of each of the element signals is then adjusted by the corresponding phase and amplitude errors.

  15. The stable computation of formal orthogonal polynomials

    NASA Astrophysics Data System (ADS)

    Beckermann, Bernhard

    1996-12-01

    For many applications - such as the look-ahead variants of the Lanczos algorithm - a sequence of formal (block-)orthogonal polynomials is required. Usually, one generates such a sequence by taking suitable polynomial combinations of a pair of basis polynomials. These basis polynomials are determined by a look-ahead generalization of the classical three term recurrence, where the polynomial coefficients are obtained by solving a small system of linear equations. In finite precision arithmetic, the numerical orthogonality of the polynomials depends on a good choice of the size of the small systems; this size is usually controlled by a heuristic argument such as the condition number of the small matrix of coefficients. However, quite often it happens that orthogonality gets lost.

  16. Higher-Pressure Ion Funnel Trap Interface for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia; Belov, Mikhail E.; Tolmachev, Aleksey V.; Prior, David C.; Smith, Richard D.

    2008-01-01

    A combined electrodynamic ion funnel and ion trap coupled to an orthogonal acceleration (oa)-time-of-flight mass spectrometer (oa-TOF MS) was developed and characterized. The ion trap was incorporated through the use of added terminal electrodynamic ion funnel electrodes enabling control over the axial DC gradient in the trap section. The ion trap operates efficiently at a pressure of 1 Torr, and measurements indicate a maximum charge capacity of ~3×107 charges. An order of magnitude increase in sensitivity was observed in the analysis of low concentration peptides mixtures with oa-TOF MS in the trapping mode as compared to the continuous regime. A signal increase in the trapping mode was accompanied by reduction in the background chemical noise, due to more efficient desolvation of e.g., solvent related clusters. Controlling the ion trap ejection time was found to result in efficient removal of singly charged species and improving signal-to-noise ratio (S/N) for the multiply charged analytes. PMID:17850113

  17. Golimumab Injection

    MedlinePlus

    ... body and causes pain, swelling, and damage) including: rheumatoid arthritis (condition in which the body attacks its own ... doctor.If golimumab injection is used to treat rheumatoid arthritis, it may also be injected intravenously (into a ...

  18. Adalimumab Injection

    MedlinePlus

    ... causes pain, swelling, and damage) including the following: rheumatoid arthritis (a condition in which the body attacks its ... If you are using adalimumab injection to treat rheumatoid arthritis, your doctor may tell you to inject the ...

  19. Aripiprazole Injection

    MedlinePlus

    ... aripiprazole injection and aripiprazole extended-release injection developed gambling problems or other intense urges or behaviors that ... even if you do not realize that your gambling or any other intense urges or unusual behaviors ...

  20. Teduglutide Injection

    MedlinePlus

    ... mix and inject it.Teduglutide comes as a kit containing vials of teduglutide powder for injection, prefilled syringes containing diluent (liquid to be mixed with teduglutide powder), needles to attach to the diluent syringe, dosing syringes ...

  1. Degarelix Injection

    MedlinePlus

    Degarelix injection is used to treat advanced prostate cancer (cancer that begins in the prostate [a male reproductive gland]). Degarelix injection is in a class of medications called gonadotropin-releasing hormone (GnRH) ...

  2. Cyclosporine Injection

    MedlinePlus

    ... injection is used with other medications to prevent transplant rejection (attack of the transplanted organ by the ... people who have received kidney, liver, and heart transplants. Cyclosporine injection should only be used to treat ...

  3. Colistimethate Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria. Colistimethate injection is in a class of medications called antibiotics. It works by killing bacteria.Antibiotics such as colistimethate injection will not work ...

  4. Chloramphenicol Injection

    MedlinePlus

    ... treat certain types of serious infections caused by bacteria when other antibiotics cannot be used. Chloramphenicol injection ... antibiotics. It works by stopping the growth of bacteria..Antibiotics such as chloramphenicol injection will not work ...

  5. Estrogen Injection

    MedlinePlus

    ... forms of estrogen injection are used to treat hot flushes (hot flashes; sudden strong feelings of heat and sweating) ... If you are using estrogen injection to treat hot flushes, your symptoms should improve within 1 to ...

  6. Medroxyprogesterone Injection

    MedlinePlus

    ... Medroxyprogesterone injection is a very effective method of birth control but does not prevent the spread of human ... you have been using a different method of birth control and are switching to medroxyprogesterone injection, your doctor ...

  7. Etanercept Injection

    MedlinePlus

    ... areas causing pain and joint damage), chronic plaque psoriasis (a skin disease in which red, scaly patches ... etanercept injection is used to treat chronic plaque psoriasis, it may be injected twice a week during ...

  8. Levoleucovorin Injection

    MedlinePlus

    Levoleucovorin injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall) when methotrexate is used to to treat certain types of cancer. Levoleucovorin injection is also used to treat people ...

  9. Leucovorin Injection

    MedlinePlus

    Leucovorin injection is used to prevent harmful effects of methotrexate (Rheumatrex, Trexall; cancer chemotherapy medication) when methotrexate is used to to treat certain types of cancer. Leucovorin injection is used to ...

  10. Teniposide Injection

    MedlinePlus

    ... in men. You should not become pregnant or breast-feed while you are receiving teniposide injection. If you or your partner become pregnant while receiving teniposide injection, call your doctor. Teniposide may harm the fetus.

  11. Ipilimumab Injection

    MedlinePlus

    ... are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while receiving ipilimumab injection, call your doctor. Ipilimumab injection may cause your baby to be born too early or to die before birth.

  12. Pralatrexate Injection

    MedlinePlus

    Pralatrexate injection is used to treat peripheral T-cell lymphoma (PTCL; a form of cancer that begins in a ... come back after treatment with other medications. Pralatrexate injection has not been shown to help people who ...

  13. Cyanocobalamin Injection

    MedlinePlus

    Cyanocobalamin injection is used to treat and prevent a lack of vitamin B12 that may be caused by any ... organs) and permanent damage to the nerves. Cyanocobalamin injection also may be given as a test to ...

  14. Paclitaxel Injection

    MedlinePlus

    Paclitaxel injection manufactured with human albumin is used to treat breast cancer that has not improved or that has come back after treatment with other medications. Paclitaxel injection manufactured with polyoxyethylated castor oil is used to ...

  15. Diphenhydramine Injection

    MedlinePlus

    Diphenhydramine injection is used to treat allergic reactions, especially for people who are unable to take diphenhydramine by mouth. ... is used also to treat motion sickness. Diphenhydramine injection is also used alone or along with other ...

  16. Peramivir Injection

    MedlinePlus

    Peramivir injection is used to treat some types of influenza infection ('flu') in people who have had symptoms of ... flu for no longer than 2 days. Peramivir injection is in a class of medications called neuraminidase ...

  17. Cefotetan Injection

    MedlinePlus

    Cefotetan injection is used to treat infections of the lungs, skin, bones, joints, stomach area, blood, female reproductive organs, and urinary tract. Cefotetan injection is also used before surgery to prevent infections. ...

  18. Mipomersen Injection

    MedlinePlus

    Mipomersen injection is used to decrease levels of cholesterol and other fatty substances in the blood in people who ... that removes LDL from the blood), but mipomersen injection should not be used along with this treatment. ...

  19. Romiplostim Injection

    MedlinePlus

    Romiplostim injection is used to increase the number of platelets (cells that help the blood to clot) in order ... low number of platelets in the blood). Romiplostim injection should only be used in people who cannot ...

  20. Hydrocortisone Injection

    MedlinePlus

    Hydrocortisone injection is used to treat symptoms of low corticosteroid levels (lack of certain substances that are usually produced ... also used to treat severe allergic reactions. Hydrocortisone injection is used in the management of multiple sclerosis ( ...

  1. Palivizumab Injection

    MedlinePlus

    Palivizumab injection is used to help prevent respiratory syncytial virus (RSV; common virus that can cause serious lung infections) ... or have certain heart or lung diseases. Palivizumab injection is not used to treat the symptoms of ...

  2. Naltrexone Injection

    MedlinePlus

    Naltrexone injection is used along with counseling and social support to help people who have stopped drinking large amounts of alcohol to avoid drinking again. Naltrexone injection is also used along with counseling and social ...

  3. Tesamorelin Injection

    MedlinePlus

    Tesamorelin injection is used to decrease the amount of extra fat in the stomach area in adults with human ... fat in certain areas of the body). Tesamorelin injection is not used to help with weight loss. ...

  4. Testosterone Injection

    MedlinePlus

    ... and testosterone pellet (Testopel) are forms of testosterone injection used to treat symptoms of low testosterone in ... are low before you begin to use testosterone injection. Testosterone enanthate (Delatestryl) and testosterone pellet (Testopel) are ...

  5. Tigecycline Injection

    MedlinePlus

    Tigecycline injection used to treat certain serious infections including community acquired pneumonia (a lung infection that developed in a ... area between the chest and the waist). Tigecycline injection should not be used to treat pneumonia that ...

  6. Eculizumab Injection

    MedlinePlus

    Eculizumab injection is used to treat paroxysmal nocturnal hemoglobinuria (PNH: a type of anemia in which too many red ... oxygen to all parts of the body). Eculizumab injection is also used to treat atypical hemolytic uremic ...

  7. Pembrolizumab Injection

    MedlinePlus

    Pembrolizumab injection is used to treat melanoma (a type of skin cancer) that cannot be treated with surgery or ... spread to other parts of the body. Pembrolizumab injection is also used to treat a certain type ...

  8. Methylprednisolone Injection

    MedlinePlus

    ... allergic reactions. Methylprednisolone injection is used in the management of multiple sclerosis (a disease in which the ... laboratory test, tell your doctor and the laboratory personnel that you are using methylprednisolone injection.If you ...

  9. Obinutuzumab Injection

    MedlinePlus

    Obinutuzumab injection is used with chlorambucil (Leukeran) to treat chronic lymphocytic leukemia (CLL; a type of cancer of the white blood cells). Obinutuzumab injection is in a class of medications called ...

  10. 2D nearly orthogonal mesh generation

    NASA Astrophysics Data System (ADS)

    Zhang, Yaoxin; Jia, Yafei; Wang, Sam S. Y.

    2004-11-01

    The Ryskin and Leal (RL) system is the most widely used mesh generation system for the orthogonal mapping. However, when this system is used in domains with complex geometry, particularly in those with sharp corners and strong curvatures, serious distortion or overlapping of mesh lines may occur and an acceptable solution may not be possible. In the present study, two methods are proposed to generate nearly orthogonal meshes with the smoothness control. In the first method, the original RL system is modified by introducing smoothness control functions, which are formulated through the blending of the conformal mapping and the orthogonal mapping; while in the second method, the RL system is modified by introducing the contribution factors. A hybrid system of both methods is also developed. The proposed methods are illustrated by several test examples. Applications of these methods in a natural river channel are demonstrated. It is shown that the modified RL systems are capable of producing meshes with an adequate balance between the orthogonality and the smoothness for complex computational domains without mesh distortions and overlapping.

  11. About orthogonality one system of functions

    NASA Astrophysics Data System (ADS)

    Barmenkov, A. N.

    2017-01-01

    For the modeling of physical processes is proposed to use representation of functions by a special trigonometric system. We present a method for constructing full orthogonal sequences of this type depending on the parameter. This parameter can be selected optimally based on specification of modeling task.

  12. Gram-Schmidt Orthogonalization by Gauss Elimination.

    ERIC Educational Resources Information Center

    Pursell, Lyle; Trimble, S. Y.

    1991-01-01

    Described is the hand-calculation method for the orthogonalization of a given set of vectors through the integration of Gaussian elimination with existing algorithms. Although not numerically preferable, this method adds increased precision as well as organization to the solution process. (JJK)

  13. Families of Ellipses and their Orthogonal Trajectories

    ERIC Educational Resources Information Center

    Ayoub, Ayoub B.

    2004-01-01

    The topic of orthogonal trajectories is taught as a geometric application of first order differential equations. Instructors usually elaborate on the concept of a family of curves to emphasize that they are different even if their members are of the same type. In this article the author considers five families of ellipses, discusses their…

  14. Multipartite invariant states. II. Orthogonal symmetry

    SciTech Connect

    Chruscinski, Dariusz; Kossakowski, Andrzej

    2006-06-15

    We construct a class of multipartite states possessing orthogonal symmetry. This new class contains multipartite states which are invariant under the action of local unitary operations introduced in our preceding paper [Phys. Rev. A 73, 062314 (2006)]. We study basic properties of multipartite symmetric states: separability criteria and multi-PPT conditions.

  15. Orthogonal and Non-Orthogonal Tight Binding Parameters for III-V Semiconductors Nitrides

    NASA Astrophysics Data System (ADS)

    Martins, A. S.; Fellows, C. E.

    2016-12-01

    A simulated annealing (SA) approach is employed in the determination of different tight binding (TB) sets of parameters for the nitride semiconductors AlN, GaN and InN, as well their limitations and potentialities are also discussed. Two kinds of atomic basis set are considered: (i) the orthogonal sp 3 s∗ with interaction up to second neighbors and (ii) a spd non-orthogonal set, with the Hamiltonian matrix elements calculated within the Extended Hückel Theory (EHT) prescriptions. For the non-orthogonal method, TB parameters are given for both zincblend and wurtzite crystalline structures.

  16. Busulfan Injection

    MedlinePlus

    Busulfex® Injection ... Busulfan injection is used to treat a certain type of chronic myelogenous leukemia (CML; a type of cancer of ... of 16 doses) before bone marrow transplant.Busulfan injection may cause seizures during therapy with the medication. ...

  17. ABJM amplitudes and the positive orthogonal Grassmannian

    NASA Astrophysics Data System (ADS)

    Huang, Yu-tin; Wen, CongKao

    2014-02-01

    A remarkable connection between perturbative scattering amplitudes of four dimensional planar SYM, and the stratification of the positive Grassmannian, was revealed in the seminal work of Arkani-Hamed et al. Similar extension for three-dimensional ABJM theory was proposed. Here we establish a direct connection between planar scattering amplitudes of ABJM theory, and singularities thereof, to the stratification of the positive orthogonal Grassmannian. In particular, scattering processes are constructed through on-shell diagrams, which are simply iterative gluing of the fundamental four-point amplitude. Each diagram is then equivalent to the merging of fundamental OG2 orthogonal Grassmannian to form a larger OG k , where 2 k is the number of external particles. The invariant information that is encoded in each diagram is precisely this stratification. This information can be easily read off via permutation paths of the on-shell diagram, which also can be used to derive a canonical representation of OG k that manifests the vanishing of consecutive minors as the singularity of all on-shell diagrams. Quite remarkably, for the BCFW recursion representation of the tree-level amplitudes, the on-shell diagram manifests the presence of all physical factorization poles, as well as the cancellation of the spurious poles. After analytically continuing the orthogonal Grassmannian to split signature, we reveal that each on-shell diagram in fact resides in the positive cell of the orthogonal Grassmannian, where all minors are positive. In this language, the amplitudes of ABJM theory is simply an integral of a product of d log forms, over the positive orthogonal Grassmannian.

  18. Influence of internal standard charge state on the accuracy of mass measurements in orthogonal acceleration time-of-flight mass spectrometers.

    PubMed

    Charles, Laurence

    2008-01-01

    Accuracy of mass measurements performed in orthogonal acceleration time-of-flight (oa-TOF) mass spectrometers highly depends on the quality of the signal and the internal calibration. The use of two reference compounds which bracket the targeted unknown, give rise to ions with sufficient signal-to-noise ratio while avoiding detector saturation and produce signals of similar intensity as compared to the target is a common requirement which allow a 5 ppm accuracy on a routine basis. Ion charge state is demonstrated here to be an additional and particularly critical parameter. Using internal references of lower charge state than the target ion systematically yielded overestimated data. Errors measured for quadruply charged molecules were in the range 16-18 ppm when mass calibrants were singly charged ions while accuracy was below 5 ppm when references and target ions were in the same charge state. Magnitude of errors was found to increase with the difference in charge state. This phenomenon arises from the orthogonal acceleration of ions in the TOF analyzer, an interface implemented in all TOF mass spectrometers to accommodate continuous beam ionization sources.

  19. Application of nano-LC-MALDI-TOF/TOF-MS for proteomic analysis of microvesicles.

    PubMed

    Kasprzyk, Joanna; Stępień, Ewa; Piekoszewski, Wojciech

    2017-03-01

    Activated platelets and platelet derived microvesicles (PMVs) emerged recently to be promising biomarkers. There is no universal procedure to carry out the proteomic analysis on microvesicles. In this study we proposed a nano-liquid chromatography (nano-LC) technique coupled off-line with a spectrometric measurement MALDI-TOF-MS/MS as a throughput and time-saving procedure. In this study we developed a simplified method to evaluate the protein composition of platelet organelles and PMVs. Platelet-rich plasma (PRP) was collected from healthy donors. PMVs were generated from washed and thrombin activated platelets. Activated platelets from every donor were used to compare the PMV proteome. Enzymatic digestion of protein lysate was carried out using Filter Aided Sample Preparation (FASP) method with trypsin as a proteolytic enzyme. Tryptic peptides derived from PMVs and activated platelets were analysed using nano-LC coupled off-line mode with a MALDI-TOF/TOF-MS. PMV and platelet protein identification was performed using the Mascot engine for searching against the Swiss-Prot human database. The precision tolerance was 100ppm for peptide masses and 0.7Da for fragment ion masses. Individual peptide matches with a score above 28 were considered statistically significant. In total, 446 proteins were identified in PMVs and 513 proteins in activated platelets. Among them 190 were specific for activated platelets and 123 were PMV specific. Cellular component analysis of identified proteins revealed that PMVs contained relatively more extracellular proteins than activated platelets (9.6 vs. 6.0 %) and unique synaptic proteins (0.3%). A new simplified bottom-up method for PMV proteome analysis allowed eliminating the drawbacks of the previously used protocols. This approach can be used in PMV proteome identification.

  20. Astrophysics at n_TOF Facility at CERN

    NASA Astrophysics Data System (ADS)

    Tagliente, G.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Bisterzo, S.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillman, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Gallino, R.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krtička, M.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Mosconi, M.; Neves, F.; Oberhummer, H.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescher, M.; Wisshak, K.

    2011-09-01

    The neutron time of flight (n_TOF) facility at CERN is a spallation neutron source with white neutron energy spectrum (from thermal to several GeV), covering the full energy range of interest for nuclear astrophysics, in particular for measurements of the neutron capture cross section required in s-process nucleosynthesis. This contribution presents an overview on the astrophysical program carried on at the n_TOF facility, the main results and their implications.

  1. Generalized Orthogonality Relations and SU(1,1)-Quantum Tomography

    NASA Astrophysics Data System (ADS)

    Carmeli, C.; Cassinelli, G.; Zizzi, F.

    2009-06-01

    We present a mathematically precise derivation of some generalized orthogonality relations for the discrete series representations of SU(1,1). These orthogonality relations are applied to derive tomographical reconstruction formulas. Their physical interpretation is also discussed.

  2. High-energy collision induced dissociation fragmentation pathways of peptides, probed using a multiturn tandem time-of-flight mass spectrometer 'MULTUM-TOF/TOF'

    SciTech Connect

    Toyoda, Michisato; Giannakopulos, Anastassios E.; Colburn, Alex W.; Derrick, Peter J.

    2007-07-15

    A new multiturn tandem time-of-flight (TOF) mass spectrometer 'MULTUM-TOF/TOF' has been designed and constructed. It consists of a matrix-assisted laser desorption/ionization ion source, a multiturn TOF mass spectrometer, a collision cell, and a quadratic-field ion mirror. The multiturn TOF mass spectrometer can overcome the problem of precursor ion selection in TOF, due to insufficient time separation between two adjacent TOF peaks, by increasing the number of cycles. As a result, the total TOF increases with the increase in resolving power. The quadratic-field ion mirror allows temporal focusing for fragment ions with different kinetic energies. Product ion spectra from monoisotopically selected precursor ions of angiotensin I, substance P, and bradykinin have been obtained. The fragment ions observed are mainly the result of high-energy collision induced dissociation.

  3. HOLA: Human-like Orthogonal Network Layout.

    PubMed

    Kieffer, Steve; Dwyer, Tim; Marriott, Kim; Wybrow, Michael

    2016-01-01

    Over the last 50 years a wide variety of automatic network layout algorithms have been developed. Some are fast heuristic techniques suitable for networks with hundreds of thousands of nodes while others are multi-stage frameworks for higher-quality layout of smaller networks. However, despite decades of research currently no algorithm produces layout of comparable quality to that of a human. We give a new "human-centred" methodology for automatic network layout algorithm design that is intended to overcome this deficiency. User studies are first used to identify the aesthetic criteria algorithms should encode, then an algorithm is developed that is informed by these criteria and finally, a follow-up study evaluates the algorithm output. We have used this new methodology to develop an automatic orthogonal network layout method, HOLA, that achieves measurably better (by user study) layout than the best available orthogonal layout algorithm and which produces layouts of comparable quality to those produced by hand.

  4. An orientation-selective orthogonal lapped transform.

    PubMed

    Kunz, Dietmar

    2008-08-01

    A novel critically sampled orientation-selective orthogonal lapped transform called the lapped Hartley transform (LHT) is derived. In a first step, overlapping basis functions are generated by modulating basis functions of a 2-D block Hartley transform by a cosine wave. To achieve invertibility and orthogonality, an iterative filter is applied as prefilter in the analysis and as postfilter in the synthesis operation, respectively. Alternatively, filtering can be restricted to analysis or synthesis, ending up with a biorthogonal transform (LHT-PR, LHT-PO). A statistical analysis based on a 4000-image data base shows that the LHT and LHT-PO have better redundancy removal properties than other block or lapped transforms. Finally, image compression and noise removal examples are given, showing the advantages of the LHT especially in images containing oriented textures.

  5. Orthogonal photoswitching in a multifunctional molecular system

    PubMed Central

    Lerch, Michael M.; Hansen, Mickel J.; Velema, Willem A.; Szymanski, Wiktor; Feringa, Ben L.

    2016-01-01

    The wavelength-selective, reversible photocontrol over various molecular processes in parallel remains an unsolved challenge. Overlapping ultraviolet-visible spectra of frequently employed photoswitches have prevented the development of orthogonally responsive systems, analogous to those that rely on wavelength-selective cleavage of photo-removable protecting groups. Here we report the orthogonal and reversible control of two distinct types of photoswitches in one solution, that is, a donor–acceptor Stenhouse adduct (DASA) and an azobenzene. The control is achieved by using three different wavelengths of irradiation and a thermal relaxation process. The reported combination tolerates a broad variety of differently substituted photoswitches. The presented system is also extended to an intramolecular combination of photoresponsive units. A model application for an intramolecular combination of switches is presented, in which the DASA component acts as a phase-transfer tag, while the azobenzene moiety independently controls the binding to α-cyclodextrin. PMID:27401266

  6. Greedy Criterion in Orthogonal Greedy Learning.

    PubMed

    Xu, Lin; Lin, Shaobo; Zeng, Jinshan; Liu, Xia; Fang, Yi; Xu, Zongben

    2017-02-23

    Orthogonal greedy learning (OGL) is a stepwise learning scheme that starts with selecting a new atom from a specified dictionary via the steepest gradient descent (SGD) and then builds the estimator through orthogonal projection. In this paper, we found that SGD is not the unique greedy criterion and introduced a new greedy criterion, called as ''δ-greedy threshold'' for learning. Based on this new greedy criterion, we derived a straightforward termination rule for OGL. Our theoretical study shows that the new learning scheme can achieve the existing (almost) optimal learning rate of OGL. Numerical experiments are also provided to support that this new scheme can achieve almost optimal generalization performance while requiring less computation than OGL.

  7. Multicarrier orthogonal spread-spectrum (MOSS) data communications

    DOEpatents

    Smith, Stephen F.; Dress, William B.

    2008-01-01

    Systems and methods are described for multicarrier orthogonal spread-spectrum (MOSS) data communication. A method includes individually spread-spectrum modulating at least two of a set of orthogonal frequency division multiplexed carriers, wherein the resulting individually spread-spectrum modulated at least two of a set of orthogonal frequency division multiplexed carriers are substantially mutually orthogonal with respect to both frequency division multiplexing and spread-spectrum modulation.

  8. Optimization of a MALDI TOF-TOF mass spectrometer for intact protein analysis.

    PubMed

    Liu, Zhaoyang; Schey, Kevin L

    2005-04-01

    A MALDI TOF-TOF instrument was optimized and evaluated for intact protein analysis by tandem mass spectrometry. Ion source voltages and delay times were adjusted to affect an up to a 10-fold improvement in fragment ion yield compared to data obtained using default settings employed in peptide analysis. For large peptides (3-4.5 kDa), up to 90% of all possible b- and y-fragment ions were observed, which provides sufficient information for de novo sequencing and unambiguous protein identification. Product ion signals associated with preferential cleavages C-terminal to aspartic acid and glutamic acid residues and N-terminal to proline residues became dominant with increased protein molecular weight. Matrix effects were also evaluated and, among the eight matrices examined, alpha-cyano-4-hydroxycinnamic acid (CHCA) was found to produce the best intact protein tandem mass spectra for proteins up to 12 kDa. Optimized performance yielded detection limits of 50-125 fmol for proteins of 4 and 12 kDa, respectively. This improved performance has yielded an instrument with potential to be a useful tool in proteomic investigations via analysis of intact proteins.

  9. High-Energy Collision-Induced Dissociation by MALDI TOF/TOF Causes Charge-Remote Fragmentation of Steroid Sulfates

    NASA Astrophysics Data System (ADS)

    Yan, Yuetian; Ubukata, Masaaki; Cody, Robert B.; Holy, Timothy E.; Gross, Michael L.

    2014-08-01

    A method for structural elucidation of biomolecules dating to the 1980s utilized high-energy collisions (~10 keV, laboratory frame) that induced charge-remote fragmentations (CRF), a class of fragmentations particularly informative for lipids, steroids, surfactants, and peptides. Unfortunately, the capability for high-energy activation has largely disappeared with the demise of magnetic sector instruments. With the latest designs of tandem time-of-flight mass spectrometers (TOF/TOF), however, this capability is now being restored to coincide with the renewed interest in metabolites and lipids, including steroid-sulfates and other steroid metabolites. For these metabolites, structure determinations are required at concentration levels below that appropriate for NMR. To meet this need, we explored CRF with TOF/TOF mass spectrometry for two groups of steroid sulfates, 3-sulfates and 21-sulfates. We demonstrated that the current generation of MALDI TOF/TOF instruments can generate charge-remote fragmentations for these materials. The resulting collision-induced dissociation (CID) spectra are useful for positional isomer differentiation and very often allow the complete structure determination of the steroid. We also propose a new nomenclature that directly indicates the cleavage sites on the steroid ring with carbon numbers.

  10. MALDI TOF/TOF-Based Approach for the Identification of d- Amino Acids in Biologically Active Peptides and Proteins.

    PubMed

    Koehbach, Johannes; Gruber, Christian W; Becker, Christian; Kreil, David P; Jilek, Alexander

    2016-05-06

    Several biologically active peptides contain a d- amino acid in a well-defined position, which is position 2 in all peptide epimers isolated to date from vertebrates and also some from invertebrates. The detection of such D- residues by standard analytical techniques is challenging. In tandem mass spectrometric (MS) analysis, although fragment masses are the same for all stereoisomers, peak intensities are known to depend on chirality. Here, we observe that the effect of a d- amino acid in the second N-terminal position on the fragmentation pattern in matrix assisted laser desorption time-of-flight spectrometry (MALDI-TOF/TOF MS) strongly depends on the peptide sequence. Stereosensitive fragmentation (SF) is correlated to a neighborhood effect, but the d- residue also exerts an overall effect influencing distant bonds. In a fingerprint analysis, multiple peaks can thus serve to identify the chirality of a sample in short time and potentially high throughput. Problematic variations between individual spots could be successfully suppressed by cospotting deuterated analogues of the epimers. By identifying the [d-Leu2] isomer of the predicted peptide GH-2 (gene derived bombininH) in skin secretions of the toad Bombina orientalis, we demonstrated the analytical power of SF-MALDI-TOF/TOF measurements. In conclusion, SF-MALDI-TOF/TOF MS combines high sensitivity, versatility, and the ability to complement other methods.

  11. MALDI TOF/TOF-Based Approach for the Identification of d- Amino Acids in Biologically Active Peptides and Proteins

    PubMed Central

    2016-01-01

    Several biologically active peptides contain a d- amino acid in a well-defined position, which is position 2 in all peptide epimers isolated to date from vertebrates and also some from invertebrates. The detection of such D- residues by standard analytical techniques is challenging. In tandem mass spectrometric (MS) analysis, although fragment masses are the same for all stereoisomers, peak intensities are known to depend on chirality. Here, we observe that the effect of a d- amino acid in the second N-terminal position on the fragmentation pattern in matrix assisted laser desorption time-of-flight spectrometry (MALDI-TOF/TOF MS) strongly depends on the peptide sequence. Stereosensitive fragmentation (SF) is correlated to a neighborhood effect, but the d- residue also exerts an overall effect influencing distant bonds. In a fingerprint analysis, multiple peaks can thus serve to identify the chirality of a sample in short time and potentially high throughput. Problematic variations between individual spots could be successfully suppressed by cospotting deuterated analogues of the epimers. By identifying the [d-Leu2] isomer of the predicted peptide GH-2 (gene derived bombininH) in skin secretions of the toad Bombina orientalis, we demonstrated the analytical power of SF-MALDI-TOF/TOF measurements. In conclusion, SF-MALDI-TOF/TOF MS combines high sensitivity, versatility, and the ability to complement other methods. PMID:26985971

  12. Orthogonal topography in the parallel input architecture of songbird HVC.

    PubMed

    Elliott, Kevin C; Wu, Wei; Bertram, Richard; Hyson, Richard L; Johnson, Frank

    2017-02-11

    Neural activity within the cortical premotor nucleus HVC (acronym is name) encodes the learned songs of adult male zebra finches (Taeniopygia guttata). HVC activity is driven and/or modulated by a group of five afferent nuclei (the Medial Magnocellular nucleus of the Anterior Nidopallium, MMAN; Nucleus Interface, NIf; nucleus Avalanche, Av; the Robust nucleus of the Arcopallium, RA; the Uvaeform nucleus, Uva). While earlier evidence suggested that HVC receives a uniformly distributed and nontopographic pattern of afferent input, recent evidence suggests this view is incorrect (Basista et al., ). Here, we used a double-labeling strategy (varying both the distance between and the axial orientation of dual tracer injections into HVC) to reveal a massively parallel and in some cases topographic pattern of afferent input. Afferent neurons target only one rostral or caudal location within medial or lateral HVC, and each HVC location receives convergent input from each afferent nucleus in parallel. Quantifying the distributions of single-labeled cells revealed an orthogonal topography in the organization of afferent input from MMAN and NIf, two cortical nuclei necessary for song learning. MMAN input is organized across the lateral-medial axis whereas NIf input is organized across the rostral-caudal axis. To the extent that HVC activity is influenced by afferent input during the learning, perception, or production of song, functional models of HVC activity may need revision to account for the parallel input architecture of HVC, along with the orthogonal input topography of MMAN and NIf. J. Comp. Neurol., 2016. © 2016 Wiley Periodicals, Inc.

  13. A high-performance matrix-assisted laser desorption/ionization orthogonal time-of-flight mass spectrometer with collisional cooling.

    PubMed

    Loboda, A V; Ackloo, S; Chernushevich, I V

    2003-01-01

    A high-performance orthogonal time-of-flight (TOF) mass spectrometer was developed specifically for use in combination with a matrix-assisted laser desorption/ionization (MALDI) source. The MALDI source features an ionization region containing a buffer gas with variable pressure. The source is interfaced to the TOF section via a collisional focusing ion guide. The pressure in the source influences the rate of cooling and allows control of ion fragmentation. The instrument provides uniform resolution up to 18,000 FWHM (full width at half maximum). Mass accuracy routinely achieved with a single-point internal recalibration is below 2 ppm for protein digest samples. The instrument is also capable of recording spectra of samples containing compounds with a broad range of masses while using one set of experimental conditions and without compromising resolution or mass accuracy.

  14. Musculoskeletal Injection

    PubMed Central

    Wittich, Christopher M.; Ficalora, Robert D.; Mason, Thomas G.; Beckman, Thomas J.

    2009-01-01

    Patients commonly present to primary care physicians with musculoskeletal symptoms. Clinicians certified in internal medicine must be knowledgeable about the diagnosis and management of musculoskeletal diseases, yet they often receive inadequate postgraduate training on this topic. The musculoskeletal problems most frequently encountered in our busy injection practice involve, in decreasing order, the knees, trochanteric bursae, and glenohumeral joints. This article reviews the clinical presentations of these problems. It also discusses musculoskeletal injections for these problems in terms of medications, indications, injection technique, and supporting evidence from the literature. Experience with joint injection and the pharmacological principles described in this article should allow primary care physicians to become comfortable and proficient with musculoskeletal injections. PMID:19720781

  15. Tracking Invisible Transformations of Physisorbed Monolayers: LDI-TOF and MALDI-TOF Mass Spectrometry as Complements to STM Imaging.

    PubMed

    He, Jian; Fang, Chen; Shelp, Russell A; Zimmt, Matthew B

    2017-01-17

    Triphenyleneethynylene (TPEE) derivatives bearing one long aliphatic chain on each terminal aryl ring and two short aliphatic chains on the central aryl ring (core chains) self-assemble single component and 1-D patterned, two-component, crystalline monolayers at the solution-graphite interface. The monolayer morphology directs the core chains off the graphite, making them accessible for chemical reactions but invisible to imaging by scanning tunneling microscopy (STM). This precludes using STM to monitor transformations of the core chains, either by reaction or solution-monolayer exchange of TPEE molecules. Laser desorption/ionization time-of-flight mass spectrometry (LDI-TOF MS) successfully identifies TPEE compounds within physisorbed monolayers. The LDI-TOF spectra of TPEE monolayer-graphite samples exhibit strong molecular ion peaks and minimal fragmentation or background. LDI-TOF and STM techniques are combined to evaluate monolayer composition and morphology, track solution-monolayer exchange, to identify reaction products and to measure kinetics of chemical reactions at the solution-monolayer interface. LDI-TOF MS provides rapid qualitative evaluation of monolayer composition across a graphite substrate. Challenges to quantitative composition evaluation by LDI-TOF include compound-specific light absorption, surface desorption/ionization and fragmentation characteristics. For some, but not all, compounds, applying matrix onto a self-assembled monolayer increases molecular ion intensities and affords more accurate assessment of monolayer composition via matrix assisted laser desorption/ionization (MALDI) MS. Matrix addition precludes subsequent chemical or STM studies of the monolayer, whereas reactions and STM may be performed at nonirradiated regions following LDI-TOF measurements. LDI- and MALDI-TOF MS are useful complements to STM and are easily implemented tools for study of physisorbed monolayers.

  16. GC-TOF/MS-based metabolomics approach to study the cellular immunotoxicity of deoxynivalenol on murine macrophage ANA-1 cells.

    PubMed

    Ji, Jian; Sun, Jiadi; Pi, Fuwei; Zhang, Shuang; Sun, Chao; Wang, Xiumei; Zhang, Yinzhi; Sun, Xiulan

    2016-08-25

    Gas chromatography-time of fly/mass spectrum (GC-TOF/MS) based complete murine macrophage ANA-1 cell metabolome strategy, including the endo-metabolome and the exo-metabolome, ANA-1 cell viability assays and apoptosis induced by diverse concentrations of DON were evaluated for selection of an optimized dose for in-depth metabolomic research. Using the optimized chromatography and mass spectrometry parameters, the metabolites detected by GC-TOF/MS were identified and processed with multivariate statistical analysis, including principal componentanalysis (PCA) and orthogonal projection to latent structures-discriminant analysis (OPLS-DA) analysis. The data sets were screened with a t-test (P) value < 0.05, VIP value > 1, similarity value > 500, leaving 16 exo-metabolite variables and 11 endo-metabolite variables for further pathway analysis. Implementing the integration of key metabolic pathways, the metabolism pathways were categorized into two dominating types, metabolism of amino acid and glycometabolism. Glycine, serine and threonine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis and phenylalanine metabolism were the significant amino acids affected by the metabolic pathways, indicating statistically significant fold changes including pyruvate, serine, glycine, lactate and threonine. Glycolysis or gluconeogenesis, starch and sucrose metabolism, and galactose metabolism, belonging to glycometabolism, were the pathways that were found to be primarily affected, resulting in abnormal metabolites such as glucose-1P, Glucose, gluconic acid, myo-inositol, sorbitol and glycerol.

  17. Momentum space orthogonal polynomial projection quantization

    NASA Astrophysics Data System (ADS)

    Handy, C. R.; Vrinceanu, D.; Marth, C. B.; Gupta, R.

    2016-04-01

    The orthogonal polynomial projection quantization (OPPQ) is an algebraic method for solving Schrödinger’s equation by representing the wave function as an expansion {{\\Psi }}(x)={\\displaystyle \\sum }n{{{Ω }}}n{P}n(x)R(x) in terms of polynomials {P}n(x) orthogonal with respect to a suitable reference function R(x), which decays asymptotically not faster than the bound state wave function. The expansion coefficients {{{Ω }}}n are obtained as linear combinations of power moments {μ }{{p}}=\\int {x}p{{\\Psi }}(x) {{d}}x. In turn, the {μ }{{p}}'s are generated by a linear recursion relation derived from Schrödinger’s equation from an initial set of low order moments. It can be readily argued that for square integrable wave functions representing physical states {{lim}}n\\to ∞ {{{Ω }}}n=0. Rapidly converging discrete energies are obtained by setting Ω coefficients to zero at arbitrarily high order. This paper introduces an extention of OPPQ in momentum space by using the representation {{Φ }}(k)={\\displaystyle \\sum }n{{{\\Xi }}}n{Q}n(k)T(k), where Q n (k) are polynomials orthogonal with respect to a suitable reference function T(k). The advantage of this new representation is that it can help solving problems for which there is no coordinate space moment equation. This is because the power moments in momentum space are the Taylor expansion coefficients, which are recursively calculated via Schrödinger’s equation. We show the convergence of this new method for the sextic anharmonic oscillator and an algebraic treatment of Gross-Pitaevskii nonlinear equation.

  18. Discriminating orthogonal single-photon images

    NASA Astrophysics Data System (ADS)

    Broadbent, Curtis J.; Zerom, Petros; Shin, Heedeuk; Howell, John C.; Boyd, Robert W.

    2009-03-01

    We can encode an image from an orthogonal basis set onto a single photon from a downconverted pair via the use of an amplitude mask. We can then discriminate the image imprinted on the photon from other images in the set using holographic-matched filtering techniques. We demonstrate this procedure experimentally for an image space of two objects, and we discuss the possibility of applying this method to a much larger image space. This process could have important implications for the manipulation of images at the quantum level.

  19. Orthogonal Synthesis of Xeno Nucleic Acids.

    PubMed

    Fiers, Guillaume; Chouikhi, Dalila; Oswald, Laurence; Al Ouahabi, Abdelaziz; Chan-Seng, Delphine; Charles, Laurence; Lutz, Jean-François

    2016-12-12

    Sequence-defined peptide triazole nucleic acids (PTzNA) were synthesized by means of a solid-phase orthogonal "AB+CD" iterative strategy. In this approach, AB and CD building blocks containing carboxylic acid (A), azide (B), alkyne (C), and primary amine (D) functions are assembled together by successive copper-catalyzed azide-alkyne cycloaddition (CuAAC) and acid-amine coupling steps. Different PTzNA genetic sequences were prepared using a library of eight building blocks (i.e., four AB and four CD building blocks).

  20. Intensity correlation of orthogonally crossed speckle waves

    NASA Astrophysics Data System (ADS)

    Okamoto, Takashi

    2006-05-01

    The statistical properties of three-dimensional laser speckles formed with orthogonally crossed multiple speckle waves are studied theoretically. The analytical expressions for the first and second order statistics of the crossed speckle fields are derived, and the theoretical results are verified by means of computer simulations. In the simulations, fractal speckles are also analyzed to examine the self-similar properties of the resulting field. The correlation properties of clipped speckles are investigated to explore the possibility of fabricating fractal random media by means of photopolymerization for three-dimensional patterning of micro structures.

  1. Noncommutative Pfaffians associated with the orthogonal algebra

    SciTech Connect

    Artamonov, Dmitrii V; Golubeva, Valentina A

    2012-12-31

    Commutators of Pfaffians associated with the orthogonal algebra are found in skew-symmetric and root realizations of o{sub N}. A generating function of Pfaffians is proved to satisfy the reflection equation. A relation between Pfaffians in skew-symmetric and root realizations of o{sub N} is established. Using these results we construct an integrable equation of Knizhnik-Zamolodchikov type using the Capelli central elements in U(o{sub N}), which are sums of squares of the considered Pfaffians. A classical limit of the obtained Knizhnik-Zamolodchikov type equation turns out to be a very specific system of equations of isomonodromic deformations. Bibliography: 18 titles.

  2. Observations on the Proper Orthogonal Decomposition

    NASA Technical Reports Server (NTRS)

    Berkooz, Gal

    1992-01-01

    The Proper Orthogonal Decomposition (P.O.D.), also known as the Karhunen-Loeve expansion, is a procedure for decomposing a stochastic field in an L(2) optimal sense. It is used in diverse disciplines from image processing to turbulence. Recently the P.O.D. is receiving much attention as a tool for studying dynamics of systems in infinite dimensional space. This paper reviews the mathematical fundamentals of this theory. Also included are results on the span of the eigenfunction basis, a geometric corollary due to Chebyshev's inequality and a relation between the P.O.D. symmetry and ergodicity.

  3. [Applications of MALDI-TOF technology in clinical microbiology].

    PubMed

    Suarez, S; Nassif, X; Ferroni, A

    2015-02-01

    Until now, the identification of micro-organisms has been based on the cultural and biochemical characteristics of bacterial and fungal species. Recently, Mass Spectrometry type Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF MS) was developed in clinical microbiology laboratories. This new technology allows identification of micro-organisms directly from colonies of bacteria and fungi within few minutes. In addition, it can be used to identify germs directly from positive blood culture bottles or directly from urine samples. Other ways are being explored to expand the use of MALDI-TOF in clinical microbiology laboratories. Indeed, some studies propose to detect bacterial antibiotic resistance while others compare strains within species for faster strain typing. The main objective of this review is to update data from the recent literature for different applications of MALDI-TOF technique in microbiological diagnostic routine.

  4. MALDI-TOF-mass spectrometry applications in clinical microbiology.

    PubMed

    Seng, Piseth; Rolain, Jean-Marc; Fournier, Pierre Edouard; La Scola, Bernard; Drancourt, Michel; Raoult, Didier

    2010-11-01

    MALDI-TOF-mass spectrometry (MS) has been successfully adapted for the routine identification of microorganisms in clinical microbiology laboratories in the past 10 years. This revolutionary technique allows for easier and faster diagnosis of human pathogens than conventional phenotypic and molecular identification methods, with unquestionable reliability and cost-effectiveness. This article will review the application of MALDI-TOF-MS tools in routine clinical diagnosis, including the identification of bacteria at the species, subspecies, strain and lineage levels, and the identification of bacterial toxins and antibiotic-resistance type. We will also discuss the application of MALDI-TOF-MS tools in the identification of Archaea, eukaryotes and viruses. Pathogenic identification from colony-cultured, blood-cultured, urine and environmental samples is also reviewed.

  5. 3D object recognition in TOF data sets

    NASA Astrophysics Data System (ADS)

    Hess, Holger; Albrecht, Martin; Grothof, Markus; Hussmann, Stephan; Oikonomidis, Nikolaos; Schwarte, Rudolf

    2003-08-01

    In the last years 3D-Vision systems based on the Time-Of-Flight (TOF) principle have gained more importance than Stereo Vision (SV). TOF offers a direct depth-data acquisition, whereas SV involves a great amount of computational power for a comparable 3D data set. Due to the enormous progress in TOF-techniques, nowadays 3D cameras can be manufactured and be used for many practical applications. Hence there is a great demand for new accurate algorithms for 3D object recognition and classification. This paper presents a new strategy and algorithm designed for a fast and solid object classification. A challenging example - accurate classification of a (half-) sphere - demonstrates the performance of the developed algorithm. Finally, the transition from a general model of the system to specific applications such as Intelligent Airbag Control and Robot Assistance in Surgery are introduced. The paper concludes with the current research results in the above mentioned fields.

  6. The application of MALDI TOF MS in biopharmaceutical research.

    PubMed

    Kafka, Alexandra P; Kleffmann, Torsten; Rades, Thomas; McDowell, Arlene

    2011-09-30

    The development and quality assessment of modern biopharmaceuticals, particularly protein and peptide drugs, requires an array of analytical techniques to assess the integrity of the bioactive molecule during formulation and administration. Mass spectrometry is one of these methods and is particularly suitable for determining chemical modifications of protein and peptide drugs. The emphasis of this review is the identification of covalent interactions between protein and peptide bioactives with polymeric pharmaceutical formulations using mass spectrometry with the main focus on matrix-assisted laser desorption/ionization (MALDI) coupled tandem time-of-flight (TOF/TOF) mass spectrometry (MS). The basics of MALDI TOF MS and collision-induced dissociation (CID)-based ion fragmentation will be explained and applications for qualitative characterization of protein and peptide drugs and their interactions with pharmaceutical polymers will be discussed using three case studies.

  7. Identification of flea species using MALDI-TOF/MS.

    PubMed

    Yssouf, Amina; Socolovschi, Cristina; Leulmi, Hamza; Kernif, Tahar; Bitam, Idir; Audoly, Gilles; Almeras, Lionel; Raoult, Didier; Parola, Philippe

    2014-05-01

    In the present study, a molecular proteomics (MALDI-TOF/MS) approach was used as a tool for identifying flea vectors. We measured the MS spectra from 38 flea specimens of 5 species including Ctenocephalides felis, Ctenocephalides canis, Archaeopsylla erinacei, Xenopsylla cheopis and Stenoponia tripectinata. A blind test performed with 24 specimens from species included in a library spectral database confirmed that MALDI-TOF/MS is an effective tool for discriminating flea species. Although fresh and 70% ethanol-conserved samples subjected to MALDI-TOF/MS in blind tests were correctly classified, only MS spectra of quality from fresh specimens were sufficient for accurate and significant identification. A cluster analysis highlighted that the MALDI Biotyper can be used for studying the phylogeny of fleas.

  8. Differentiation of isomeric N-glycan structures by normal-phase liquid chromatography-MALDI-TOF/TOF tandem mass spectrometry.

    PubMed

    Maslen, Sarah; Sadowski, Pawel; Adam, Alex; Lilley, Kathryn; Stephens, Elaine

    2006-12-15

    The detailed characterization of protein N-glycosylation is very demanding given the many different glycoforms and structural isomers that can exist on glycoproteins. Here we report a fast and sensitive method for the extensive structure elucidation of reducing-end labeled N-glycan mixtures using a combination of capillary normal-phase HPLC coupled off-line to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and TOF/TOF-MS/MS. Using this method, isobaric N-glycans released from honey bee phospholipase A2 and Arabidopsis thaliana glycoproteins were separated by normal-phase chromatography and subsequently identified by key fragment ions in the MALDI-TOF/TOF tandem mass spectra. In addition, linkage and branching information were provided by abundant cross-ring and "elimination" fragment ions in the MALDI-CID spectra that gave extensive structural information. Furthermore, the fragmentation characteristics of N-glycans reductively aminated with 2-aminobenzoic acid and 2-aminobenzamide were compared. The identification of N-glycans containing 3-linked core fucose was facilitated by distinctive ions present only in the MALDI-CID spectra of 2-aminobenzoic acid-labeled oligosaccharides. To our knowledge, this is the first MS/MS-based technique that allows confident identification of N-glycans containing 3-linked core fucose, which is a major allergenic determinant on insect and plant glycoproteins.

  9. Speciation of surface gold in pressure oxidized carbonaceous gold ores by TOF-SIMS and TOF-LIMS

    NASA Astrophysics Data System (ADS)

    Dimov, S. S.; Chryssoulis, S. L.; Sodhi, R. N.

    2003-01-01

    To the best of our knowledge, this is the first attempt ever to speciate gold preg-robbed by carbonaceous matter using a surface sensitive microbeam technique. This approach enables the direct determination of gold species sorbed on carbonaceous particulates thus providing a new tool in understanding the chemistry of gold sorption on carbon. The reasoning behind this effort was to study the detrimental effect chloride ions have on gold recovery by pressure oxidation of carbonaceous sulfide ores, a technology largely used by the mining industry. The characterization of the sorbed gold species involved three surface sensitive microbeam analytical techniques (TOF-SIMS, TOF-LIMS and XPS) providing confirmatory results for better accuracy. Optimum conditions for detection of gold compounds with minimum fragmentation by TOF-SIMS and TOF-LIMS mass spectrometers have been determined. A reference library of 16 major gold complexes with halogen, thiosulfate, cyanide and thiocyanate groups relevant to the gold recovery processes has been established. The most suitable of the microbeam techniques tested was found to be negative (-ve) ion TOF-LIMS, offering best sensitivity and a small analytical spot size.

  10. Orthogonal optical label swapping and novel BER algorithm for 8PSK signal

    NASA Astrophysics Data System (ADS)

    Tang, Chanjuan; Tao, Li; Li, Rongling; Fang, Wuliang; Zou, Shumin; Chi, Nan

    2011-12-01

    For the first time, we propose a novel BER estimation algorithm for 8PSK signal, the idea of which is also applicable to other multi-dimensional and multi-level modulation formats. And a 2 × 4 orthogonal optical label swapping based on 120Gb/s 8PSK payload and 78Mb/s ASK label by using optical switching devices is demonstrated. Through numerical simulations under different circumstances, we get some orthogonal label switching network's characteristics by analyzing the receiver BER utilizing the new BER algorithm, such as that different combination of label will have a different impact on the transmission performance of the packets. In addition, by changing the receiver optical power, transmitter optical power and optical power launched into the fiber, we get the system's receiver sensitivity, the optimum transmitter power and optimum optical power injected into the fiber, which will be a reference for the actual systems' design.

  11. Certolizumab Injection

    MedlinePlus

    ... has not improved when treated with other medications, rheumatoid arthritis (a condition in which the body attacks its ... continues. When certolizumab injection is used to treat rheumatoid arthritis, it is usually given every other week and ...

  12. Natalizumab Injection

    MedlinePlus

    ... prevent episodes of symptoms in people who have Crohn's disease (a condition in which the body attacks the ... If you are receiving natalizumab injection to treat Crohn's disease, your symptoms should improve during the first few ...

  13. Vedolizumab Injection

    MedlinePlus

    ... injection may cause serious allergic reactions during an infusion and for several hours afterward. A doctor or ... of the following symptoms during or after your infusion: rash; itching; swelling of the face, eyes, mouth, ...

  14. Panitumumab Injection

    MedlinePlus

    ... as a solution (liquid) to be given by infusion (injected into a vein). It is usually given ... doctor or nurse in a doctor's office or infusion center. Panitumumab is usually given once every 2 ...

  15. Methotrexate Injection

    MedlinePlus

    ... woman's uterus while she is pregnant), breast cancer, lung cancer, certain cancers of the head and neck; certain ... Methotrexate injection is also used along with rest, physical therapy and ... treat rheumatoid arthritis by decreasing the activity of the immune system.

  16. Alirocumab Injection

    MedlinePlus

    ... injection is used along with diet and certain cholesterol-lowering medications (HMG-CoA reductase inhibitors [statins]) in ... familial heterozygous hypercholesterolemia (an inherited condition in which cholesterol cannot be removed from the body normally) or ...

  17. Evolocumab Injection

    MedlinePlus

    ... injection is used along with diet and certain cholesterol-lowering medications, HMG-CoA reductase inhibitors (statins), in ... heterozygous hypercholesterolemia (HeFH; an inherited condition in which cholesterol cannot be removed from the body normally) or ...

  18. Pentamidine Injection

    MedlinePlus

    Pentamidine injection is used to treat pneumonia caused by a fungus called Pneumocystis carinii. It is in a class of medications called antiprotozoals. It works by stopping the growth of protozoa that can cause pneumonia.

  19. Oxytocin Injection

    MedlinePlus

    Oxytocin injection is used to begin or improve contractions during labor. Oxytocin also is used to reduce bleeding after childbirth. ... other medications or procedures to end a pregnancy. Oxytocin is in a class of medications called oxytocic ...

  20. Ibritumomab Injection

    MedlinePlus

    ... is in a class of medications called monoclonal antibodies with radioisotopes. It works by attaching to cancer ... you receive ibritumomab injection, your body may develop antibodies (substances in the blood that help the immune ...

  1. Ganciclovir Injection

    MedlinePlus

    ... problems, eye problems other than CMV retinitis, or kidney disease.tell your doctor if you are pregnant or plan to become pregnant. Ganciclovir injection may cause infertility (difficulty becoming pregnant). However, if you are a ...

  2. Bendamustine Injection

    MedlinePlus

    ... a type of cancer of the white blood cells). Bendamustine injection is also used to treat a ... that begins in a type of white blood cell that normally fights infection) that is slow spreading, ...

  3. Vancomycin Injection

    MedlinePlus

    ... medications called glycopeptide antibiotics. It works by killing bacteria that cause infections.Antibiotics such as vancomycin injection ... infection may not be completely treated and the bacteria may become resistant to antibiotics.

  4. Levofloxacin Injection

    MedlinePlus

    ... of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.Antibiotics such as levofloxacin injection ... infection may not be completely treated and the bacteria may become resistant to antibiotics.

  5. Doxycycline Injection

    MedlinePlus

    ... medications called tetracycline antibiotics. It works by killing bacteria that cause infections.Antibiotics such as doxycycline injection ... infection may not be completely treated and the bacteria may become resistant to antibiotics.

  6. Sumatriptan Injection

    MedlinePlus

    ... accompanied by nausea and sensitivity to sound and light). Sumatriptan injection is also used to treat the ... children. Store it at room temperature, away from light, excess heat, and moisture (not in the bathroom). ...

  7. Alemtuzumab Injection

    MedlinePlus

    ... injection, the medication is usually given three times weekly on alternate days (usually Monday, Wednesday, and Friday) ... that you eat foods that are rich in iron such as meats, leafy green vegetables, and fortified ...

  8. Epinephrine Injection

    MedlinePlus

    Epinephrine injection is used along with emergency medical treatment to treat life-threatening allergic reactions caused by ... or stings, foods, medications, latex, and other causes. Epinephrine is in a class of medications called alpha- ...

  9. Mitoxantrone Injection

    MedlinePlus

    ... medications to relieve pain in people with advanced prostate cancer who did not respond to other medications. Mitoxantrone ... doses). When mitoxantrone injection is used to treat prostate cancer, it is usually given once every 21 days. ...

  10. Trastuzumab Injection

    MedlinePlus

    ... with other medications to treat certain types of stomach cancer that have spread to other parts of the ... weeks. When trastuzumab injection is used to treat stomach cancer, it is usually given once every 3 weeks. ...

  11. Topotecan Injection

    MedlinePlus

    ... organs where eggs are formed) and small cell lung cancer (a type of cancer that begins in the ... topotecan injection is used to treat ovarian or lung cancer, it is usually given once a day for ...

  12. Palonosetron Injection

    MedlinePlus

    ... that may occur several days after receiving certain chemotherapy medications. Palonosetron injection is in a class of medications called 5-HT3 receptor antagonists. It works by blocking the action of serotonin, a natural ...

  13. Meropenem Injection

    MedlinePlus

    ... skin and abdominal (stomach area) infections caused by bacteria and meningitis (infection of the membranes that surround ... of medications called antibiotics. It works by killing bacteria that cause infection.Antibiotics such as meropenem injection ...

  14. Amikacin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as amikacin injection will not work ...

  15. Ertapenem Injection

    MedlinePlus

    ... abdominal (stomach area) infections, that are caused by bacteria. It is also used for the prevention of ... medications called carbapenem antibiotics. It works by killing bacteria.Antibiotics such as ertapenem injection will not work ...

  16. Moxifloxacin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as pneumonia; ; and , skin, and abdominal (stomach ... antibiotics called fluoroquinolones. It works by killing the bacteria that cause infections.Antibiotics such as moxifloxacin injection ...

  17. Cefepime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia, and skin, urinary tract, and kidney ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefepime injection will not work ...

  18. Cefazolin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including skin, bone, joint, genital, blood, heart valve, ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as cefazolin injection will not work ...

  19. Daptomycin Injection

    MedlinePlus

    ... blood infections or serious skin infections caused by bacteria. Daptomycin injection is in a class of medications called cyclic lipopeptide antibiotics. It works by killing bacteria. Antibiotics will not work for treating colds, flu, ...

  20. Aztreonam Injection

    MedlinePlus

    ... to treat certain infections that are caused by bacteria, including respiratory tract (including pneumonia and bronchitis), urinary ... abdominal (stomach area) infections, that are caused by bacteria. Aztreonam injection also may be used before, during, ...

  1. Ceftazidime Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria including pneumonia and other lower respiratory tract (lung) ... medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftazidime injection will not work ...

  2. Tobramycin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as tobramycin injection will not work ...

  3. Ciprofloxacin Injection

    MedlinePlus

    ... is used to treat certain infections caused by bacteria such as pneumonia; and infections of the skin, ... of antibiotics called fluoroquinolones. It works by killing bacteria that cause infections.Antibiotics such as ciprofloxacin injection ...

  4. Gentamicin Injection

    MedlinePlus

    ... treat certain serious infections that are caused by bacteria such as meningitis (infection of the membranes that ... medications called aminoglycoside antibiotics. It works by killing bacteria.Antibiotics such as gentamicin injection will not work ...

  5. Ceftaroline Injection

    MedlinePlus

    ... infections and pneumonia (lung infection) caused by certain bacteria. Ceftaroline is in a class of medications called cephalosporin antibiotics. It works by killing bacteria.Antibiotics such as ceftaroline injection will not work ...

  6. Daclizumab Injection

    MedlinePlus

    ... course of disease where symptoms flare up from time to time) of multiple sclerosis (MS; a disease in which ... injections. Before you use daclizumab yourself the first time, read the written instructions that come with it. ...

  7. Risperidone Injection

    MedlinePlus

    ... release (long-acting) injection is used to treat schizophrenia (a mental illness that causes disturbed or unusual ... do not already have diabetes. If you have schizophrenia, you are more likely to develop diabetes than ...

  8. Acyclovir Injection

    MedlinePlus

    ... chickenpox in the past) in people with weak immune systems. It is also used to treat first-time ... from time to time) in people with normal immune systems. Acyclovir injection is used to treat herpes simplex ...

  9. Omalizumab Injection

    MedlinePlus

    ... steroids. Omalizumab is also used to treat chronic hives without a known cause that cannot successfully be ... is not used to treat other forms of hives or allergic conditions. Omalizumab injection is in a ...

  10. Pegloticase Injection

    MedlinePlus

    ... doctor if you have glucose-6-phosphate dehydrogenase (G6PD) deficiency (an inherited blood disease). Your doctor may test you for G6PD deficiency before you start to receive pegloticase injection. If ...

  11. Lacosamide Injection

    MedlinePlus

    ... with other medications to control certain types of seizures in people who cannot take oral medications. Lacosamide ... If you suddenly stop using lacosamide injection, your seizures may happen more often. Your doctor will probably ...

  12. Oxacillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to oxacillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  13. Nafcillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to nafcillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin, cefdinir, ...

  14. Ampicillin Injection

    MedlinePlus

    ... injection is in a class of medications called penicillins. It works by killing bacteria.Antibiotics such as ... and pharmacist if you are allergic to ampicillin; penicillins; cephalosporin antibiotics such as cefaclor, cefadroxil, cefazolin (Ancef, ...

  15. Naloxone Injection

    MedlinePlus

    ... emergency medical treatment to reverse the life-threatening effects of a known or suspected opiate (narcotic) overdose. ... is also used after surgery to reverse the effects of opiates given during surgery. Naloxone injection is ...

  16. Omacetaxine Injection

    MedlinePlus

    ... or cannot take these medications due to side effects. Omacetaxine injection is in a class of medications ... a treatment cycle if you experience serious side effects of the medication or if blood tests show ...

  17. Methylnaltrexone Injection

    MedlinePlus

    ... injection is used to treat constipation caused by opioid (narcotic) pain medications in patients with chronic (on-going) pain that is not caused by ... by protecting the bowel from the effects of opioid (narcotic) medications.

  18. Denosumab Injection

    MedlinePlus

    ... menstrual periods), who have an increased risk for fractures (broken bones) or who cannot take or did ... receiving certain treatments that increase their risk for fractures. Denosumab injection (Xgeva) is used to reduce fractures ...

  19. Rasburicase Injection

    MedlinePlus

    ... break down) in people with certain types of cancer who are being treated with chemotherapy medications. Rasburicase injection is in a class of medications called enzymes. It works by breaking down uric acid so that the body can eliminate it.

  20. Gemcitabine Injection

    MedlinePlus

    ... with surgery. Gemcitabine is also used to treat cancer of the pancreas that has spread to other parts of the ... 4 weeks. When gemcitabine is used to treat cancer of pancreas it may be injected once every week. The ...

  1. Doxercalciferol Injection

    MedlinePlus

    Doxercalciferol injection is used to treat secondary hyperparathyroidism (a condition in which the body produces too much parathyroid hormone [PTH; a natural substance needed to control the amount of calcium in ...

  2. Granisetron Injection

    MedlinePlus

    ... that may occur after surgery. Granisetron extended-release (long-acting) injection is used with other medications to prevent nausea and vomiting caused by cancer chemotherapy that may occur immediately ...

  3. Fluconazole Injection

    MedlinePlus

    ... injection is used to treat fungal infections, including yeast infections of the mouth, throat, esophagus (tube leading ... by fungus. Fluconazole is also used to prevent yeast infections in patients who are likely to become ...

  4. Docetaxel Injection

    MedlinePlus

    ... allergic to docetaxel injection or drugs made with polysorbate 80, an ingredient found in some medications. Ask ... if a medication you are allergic to contains polysorbate 80. If you experience any of the following ...

  5. Haloperidol Injection

    MedlinePlus

    ... emotions). Haloperidol injection is also used to control motor tics (uncontrollable need to repeat certain body movements) ... people who have Tourette's disorder (condition characterized by motor or verbal tics). Haloperidol is in a class ...

  6. Qualitative and quantitative analyses of alkaloids in Uncaria species by UPLC-ESI-Q-TOF/MS.

    PubMed

    Wang, Hai-Bo; Qi, Wen; Zhang, Lin; Yuan, Dan

    2014-01-01

    An ultra performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (Q-TOF/MS) method has been optimized and established for the rapid analysis of the alkaloids in 22 samples originating from five Uncaria (U.) species. The accurate mass measurement of all the protonated molecules and subsequent fragment ions offers higher quality structural information for the interpretation of fragmentation pathways of the various groups of alkaloids. A total of 19 oxindole alkaloids, 16 indole alkaloids and 1 flavone were identified by co-chromatography of the sample extract with authentic standards, comparison of the retention time, characteristic molecular ions and fragment ions, or were tentatively identified by MS/MS determination. Moreover, the method was validated for the simultaneous quantification of the 24 components within 10.5 min. The potential chemical markers were identified for classification of the U. species samples by principal component analysis (PCA) and orthogonal partial least squared discriminant analysis (OPLS-DA). The results demonstrate the similarity and differences in alkaloids among the five U. species, which is helpful for the standardization and quality control of the medical materials of the U. Ramulus Cum Unics (URCU). Furthermore, with multivariate statistical analysis, the determined markers are more definite and useful for chemotaxonomy of the U. genus.

  7. Orthogonally-oriented nanotube arrays: experiment I.

    PubMed

    Sheehan, D P; Webster, J T; Baird, L M

    2007-10-01

    Recently a new type of self-assembling surface has been proposed that, in theory, possesses a number of desirable tribological, electrical, and thermal characterstics. The surface consists of arrays of carbon nanotubes partially embedded lengthwise in a substrate such that when two arrayed surfaces are brought together orthogonally, the areal contact between them is small, limited to a lattice of nearly point-like contacts. These orthogonally-oriented nanotube arrays (ONAs) are predicted to exhibit: (i) surface adhesion (stiction) 10-100 times less than for Teflon or other advanced perfluorocarbons; (ii) frictional coefficients up to 1000 times less than for conventional solids; (iii) ultra-low wear; and (iv) superior thermal and electrical conductivity. In this paper, laboratory methods are described for embedding nanotubes in trenched substrates. Using microscopically trenched substrates and a custom ultrasonic atomization source, experiments show that individual nanotubes can spontaneously and controllably entrench themselves via interfacial forces (capillary and surface tension). Results indicate ONAs might be relatively simply and inexpensively fabricated. More decisive experiments are proposed.

  8. Injection overview

    SciTech Connect

    Prestwich, S.

    1983-12-01

    The test program was initiated at the Raft River Geothermal Field in southern Idaho in September 1982. A series of eight short-term injection and backflow tests, followed by a long-term injection test, were conducted on one well in the field. Tracers were added during injection and monitored during backflow as well. The principal objective was to determine if tracers could be effectively used as a means to assess reservoir characteristics in a one-well test. The test program resulted in a unique data set which shows promise as a means to improve understanding of the reservoir characteristics. In December 1982, an RFP was issued to obtain an industrial partner to obtain follow-on data on the injection/backflow technique in a second field, and to study any alternate advanced concepts for injection testing which the industrial community might recommend. The East Mesa Geothermal Field was selected for the second test series. Two wells were utilized for testing, and a series of ten tests were conducted in July and August 1983, aimed principally at further evaluation of the injection/backflow technique.

  9. C60 SIMS with a Hybrid-Quadrupole Orthogonal time-of-flight Mass Spectrometer

    PubMed Central

    Carado, Anthony; Passarelli, M. K.; Kozole, Joseph; Wingate, J. E.; Winograd, Nicholas; Loboda, A. V.

    2009-01-01

    A hybrid quadrupole orthogonal time-of-flight mass spectrometer optimized for MALDI and electrospray ionization has been equipped with a C60 cluster ion source. This configuration is shown to exhibit a number of characteristics that improve the performance of traditional time-of-flight secondary ion mass spectrometry (SIMS) experiments for the analysis of complex organic materials, and potentially, for chemical imaging. Specifically, the primary ion beam is operated as a continuous rather than a pulsed beam, resulting in up to 4 orders of magnitude greater ion fluence on the target. The secondary ions are extracted at very low voltage into 8 millitorr of N2 gas introduced for collisional focusing and cooling purposes. This extraction configuration is shown to yield secondary ions that rapidly lose memory of the mechanism of their birth, yielding tandem mass spectra that are identical for SIMS and MALDI. With implementation of ion trapping, the extraction efficiency is shown to be equivalent to that found in traditional TOF-SIMS machines. Examples are given, for a variety of substrates that illustrate mass resolution of 12,000–15,600 with mass range for inorganic compounds to m/z 40,000. Preliminary chemical mapping experiments show that with added sensitivity, imaging in the MS/MS mode of operation is straightforward. In general, the combination of MALDI and SIMS is shown to add capabilities to each technique, providing a robust platform for TOF-SIMS experiments that already exists in a large number of laboratories. PMID:18844371

  10. MALDI-TOF MS analysis of plant proanthocyanidins.

    PubMed

    Monagas, María; Quintanilla-López, Jesús Eduardo; Gómez-Cordovés, Carmen; Bartolomé, Begoña; Lebrón-Aguilar, Rosa

    2010-01-20

    Proanthocyanidins or condensed tannins are among the most abundant polyphenols compounds in our diet and may play a key role in the prevention of cardiovascular and neurodegenerative diseases and cancer. These antioxidants are widely distributed in the plant kingdom both in food plants and in non-food plants. The biological activity of plant proanthocyanidins depends on their chemical structure and concentration. However, due to their structural diversity and complexity, the qualitative and quantitative analysis of proanthocyanidins is a difficult task. Mass spectrometry has enabled great advances in the characterization of plant proanthocyanidins. Among these techniques, MALDI-TOF MS has proved to be highly suited for the analysis of highly polydisperse and heterogeneous proanthocyanidins. The objective of the present paper was to assess the potential, limitations and future challenges of the analysis of plant proanthocyanidins by MALDI-TOF MS techniques. Firstly, the fundamental of this technique, including modes of operation, advantages and limitations, as well as quantitative and qualitative operations, have been summarized. Applications of MALDI-TOF analysis to plant proanthocyanidins reported in the last decade (1997-2008) have been extensively covered, including the sample preparation protocols and conditions used for proanthocyanidin analysis, as well as the main findings regarding the determination of the structural features of different plant proanthocyanidin types (procyanidins, propelargonidins, prodelphinidins, profisetinidins and prorobinetinidins). Finally, attempts in the assessment of the molecular weight distribution of proanthocyanidins by MALDI-TOF are described.

  11. DNA analysis by MALDI-TOF mass spectrometry.

    PubMed

    Gut, Ivo Glynne

    2004-05-01

    The last decade has seen an increased demand for high-throughput DNA analysis. This is mainly due to the human genome sequencing project that is now completed. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry was pinpointed early on as a technology that could be of great use for sequence variation analysis in the post-genome sequencing era. Applications developed first on this platform were for SNP genotyping. Several strategies for allele-discrimination (hybridization, cleavage, ligation, and primer extension) were combined with MALDI-TOF mass spectrometric detection. Nowadays, in practice, only primer extension methods are applied for large-scale SNP genotyping studies with MALDI-TOF detection. Problems surrounding the integration of SNP genotyping by MALDI-TOF mass spectrometry at high throughput are largely mastered now. Mass spectrometry geared presentations at the HUGO Mutation Detection Meeting in Palm Cove, Australia almost exclusively focused on novel applications that go beyond standard SNP genotyping. These applications are more demanding in terms of chemistry and molecular biology. Molecular haplotyping, expression profiling, DNA methylation analysis, and mutation detection are now being demonstrated.

  12. Inverse solutions for tilting orthogonal double prisms.

    PubMed

    Li, Anhu; Ding, Ye; Bian, Yongming; Liu, Liren

    2014-06-10

    An analytical reverse solution and actual examples are given to show how to direct a laser beam from a pair of orthogonal prisms to given targets in free space. Considering the influences of double-prism structural parameters, a lookup table method to seek the numerical reverse solution of each prism's tilting angle is also proposed for steering the double-prism orientation to track a target position located in the near field. Some case studies, as well as a specified elliptical target trajectory scanned by the cam-based driving double prisms, exhibit the significant application values of the theoretical derivation. The analytic reverse and numerical solutions can be generalized to investigate the synthesis of scanning patterns and the controlling strategy of double-prism tilting motion, the potentials of which can be explored to perform the orientation and position tracking functions in applications of precision engineering fields.

  13. Measuring the orthogonality error of coil systems

    USGS Publications Warehouse

    Heilig, B.; Csontos, A.; Pajunpää, K.; White, Tim; St. Louis, B.; Calp, D.

    2012-01-01

    Recently, a simple method was proposed for the determination of pitch angle between two coil axes by means of a total field magnetometer. The method is applicable when the homogeneous volume in the centre of the coil system is large enough to accommodate the total field sensor. Orthogonality of calibration coil systems used for calibrating vector magnetometers can be attained by this procedure. In addition, the method can be easily automated and applied to the calibration of delta inclination–delta declination (dIdD) magnetometers. The method was tested by several independent research groups, having a variety of test equipment, and located at differing geomagnetic observatories, including: Nurmijärvi, Finland; Hermanus, South Africa; Ottawa, Canada; Tihany, Hungary. This paper summarizes the test results, and discusses the advantages and limitations of the method.

  14. Response Surface Modeling Using Multivariate Orthogonal Functions

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.; DeLoach, Richard

    2001-01-01

    A nonlinear modeling technique was used to characterize response surfaces for non-dimensional longitudinal aerodynamic force and moment coefficients, based on wind tunnel data from a commercial jet transport model. Data were collected using two experimental procedures - one based on modem design of experiments (MDOE), and one using a classical one factor at a time (OFAT) approach. The nonlinear modeling technique used multivariate orthogonal functions generated from the independent variable data as modeling functions in a least squares context to characterize the response surfaces. Model terms were selected automatically using a prediction error metric. Prediction error bounds computed from the modeling data alone were found to be- a good measure of actual prediction error for prediction points within the inference space. Root-mean-square model fit error and prediction error were less than 4 percent of the mean response value in all cases. Efficacy and prediction performance of the response surface models identified from both MDOE and OFAT experiments were investigated.

  15. Partially orthogonal resonators for magnetic resonance imaging

    PubMed Central

    Chacon-Caldera, Jorge; Malzacher, Matthias; Schad, Lothar R.

    2017-01-01

    Resonators for signal reception in magnetic resonance are traditionally planar to restrict coil material and avoid coil losses. Here, we present a novel concept to model resonators partially in a plane with maximum sensitivity to the magnetic resonance signal and partially in an orthogonal plane with reduced signal sensitivity. Thus, properties of individual elements in coil arrays can be modified to optimize physical planar space and increase the sensitivity of the overall array. A particular case of the concept is implemented to decrease H-field destructive interferences in planar concentric in-phase arrays. An increase in signal to noise ratio of approximately 20% was achieved with two resonators placed over approximately the same planar area compared to common approaches at a target depth of 10 cm at 3 Tesla. Improved parallel imaging performance of this configuration is also demonstrated. The concept can be further used to increase coil density. PMID:28186135

  16. Partially orthogonal resonators for magnetic resonance imaging

    NASA Astrophysics Data System (ADS)

    Chacon-Caldera, Jorge; Malzacher, Matthias; Schad, Lothar R.

    2017-02-01

    Resonators for signal reception in magnetic resonance are traditionally planar to restrict coil material and avoid coil losses. Here, we present a novel concept to model resonators partially in a plane with maximum sensitivity to the magnetic resonance signal and partially in an orthogonal plane with reduced signal sensitivity. Thus, properties of individual elements in coil arrays can be modified to optimize physical planar space and increase the sensitivity of the overall array. A particular case of the concept is implemented to decrease H-field destructive interferences in planar concentric in-phase arrays. An increase in signal to noise ratio of approximately 20% was achieved with two resonators placed over approximately the same planar area compared to common approaches at a target depth of 10 cm at 3 Tesla. Improved parallel imaging performance of this configuration is also demonstrated. The concept can be further used to increase coil density.

  17. Orthogonal patterns in binary neural networks

    NASA Technical Reports Server (NTRS)

    Baram, Yoram

    1988-01-01

    A binary neural network that stores only mutually orthogonal patterns is shown to converge, when probed by any pattern, to a pattern in the memory space, i.e., the space spanned by the stored patterns. The latter are shown to be the only members of the memory space under a certain coding condition, which allows maximum storage of M=(2N) sup 0.5 patterns, where N is the number of neurons. The stored patterns are shown to have basins of attraction of radius N/(2M), within which errors are corrected with probability 1 in a single update cycle. When the probe falls outside these regions, the error correction capability can still be increased to 1 by repeatedly running the network with the same probe.

  18. Fragmentation of Leucine Enkephalin as a Function of Laser Fluence in a MALDI TOF-TOF

    PubMed Central

    Campbell, Jennifer M.; Stein, Stephen E.; Blank, Paul S.; Epstein, Jonathan A.; Vestal, Marvin L.; Yergey, Alfred L.

    2007-01-01

    The effects of laser fluence on ion formation in MALDI were studied using a tandem TOF mass spectrometer with a Nd-YAG laser and alpha-cyano hydrocinnamic acid matrix. Leucine enkephalin ionization and fragmentation were followed as a function of laser fluence ranging from the threshold of ion formation to the maximum available, i.e., approximately 280 – 930 mJ/mm2. The most notable finding was the appearance of immonium ions at fluence values close to threshold, increasing rapidly and then tapering in intensity with the appearance of typical backbone fragment ions. The data suggest the presence of two distinct environments for ion formation. One is associated with molecular desorption at low values of laser fluence that leads to extensive immonium ion formation. The second becomes dominant at higher fluences, is associated initially with backbone type fragments, but, at the highest values of fluence, progresses to immonium fragments. This second environment is suggestive of ion desorption from large pieces of material ablated from the surface. Arrhenius rate law considerations were used to estimate temperatures associated with the onset of these two processes. PMID:17204430

  19. LOCC indistinguishable orthogonal product quantum states

    PubMed Central

    Zhang, Xiaoqian; Tan, Xiaoqing; Weng, Jian; Li, Yongjun

    2016-01-01

    We construct two families of orthogonal product quantum states that cannot be exactly distinguished by local operation and classical communication (LOCC) in the quantum system of 2k+i ⊗ 2l+j (i, j ∈ {0, 1} and i ≥ j ) and 3k+i ⊗ 3l+j (i, j ∈ {0, 1, 2}). And we also give the tiling structure of these two families of quantum product states where the quantum states are unextendible in the first family but are extendible in the second family. Our construction in the quantum system of 3k+i ⊗ 3l+j is more generalized than the other construction such as Wang et al.’s construction and Zhang et al.’s construction, because it contains the quantum system of not only 2k ⊗ 2l and 2k+1 ⊗ 2l but also 2k ⊗ 2l+1 and 2k+1 ⊗ 2l+1. We calculate the non-commutativity to quantify the quantumness of a quantum ensemble for judging the local indistinguishability. We give a general method to judge the indistinguishability of orthogonal product states for our two constructions in this paper. We also extend the dimension of the quantum system of 2k ⊗ 2l in Wang et al.’s paper. Our work is a necessary complement to understand the phenomenon of quantum nonlocality without entanglement. PMID:27377310

  20. Pegaptanib Injection

    MedlinePlus

    ... if you have or have ever had diabetes, high blood pressure, a heart attack, or a stroke.tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while using pegaptanib injection, ...

  1. Ramucirumab Injection

    MedlinePlus

    ... doctor if you have or have ever had high blood pressure, a wound that has not healed, or liver disease.tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. Ramucirumab injection may harm your unborn baby. You ...

  2. Reslizumab Injection

    MedlinePlus

    ... the infusion or for a short period of time after the infusion has finished.You will receive each injection of reslizumab in a doctor's office or medical facility. You will stay in the office for some time after you receive the medication so your doctor ...

  3. Dexrazoxane Injection

    MedlinePlus

    ... are used to treat or prevent certain side effects that may be caused by chemotherapy medications. Dexrazoxane ... Dexrazoxane injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away: pain or swelling in the place ...

  4. Improvement of the duty cycle of an orthogonal acceleration time-of-flight mass spectrometer using ion gates.

    PubMed

    Brenton, A G; Krastev, T; Rousell, D J; Kennedy, M A; Craze, A S; Williams, C M

    2007-01-01

    A method to control the duty cycle of a time-of-flight mass spectrometer is described. The method relies on one or more ion gates placed in the beam path that have the function to transmit or stop the beam. These ion gates can switch from the open state to the closed state in tens of nanoseconds and effectively select portions of the mass range. The method is useful in circumstances where recording the complete mass spectrum is not an essential requirement, for example, in the analysis of known compounds where sensitivity and speed of operation are more important. It will be of benefit for applications in separation sciences with techniques involving fast chromatographic separations, where hundreds of mass spectra may be required per second. In such circumstances analytical identification may require only a limited number of masses (or mass regions) to be continuously monitored. Improvement of the duty cycle is particularly important for orthogonal-acceleration time-of-flight (oa-TOF) mass spectrometry instruments whose performance suffers from a low duty cycle. The duty cycle is not a constant for an instrument design but is a mass-dependent function and is least for smaller masses. The method described here is capable of raising the duty cycle to 100%. A theory is developed for one or more ion gate arrangements, for both linear- and reflectron-TOF systems. For a two-gate system the relationship between the positions of the first and second gates is described by a '2/3 rule'. Experimental results are shown for one-gate and two-gate operation, both in linear and in reflectron modes of operation, on an oa-TOF system built in-house.

  5. Coumarin tags for analysis of peptides by MALDI-TOF MS and MS/MS. 2. Alexa Fluor 350 tag for increased peptide and protein Identification by LC-MALDI-TOF/TOF MS.

    PubMed

    Pashkova, Anna; Chen, Hsuan-Shen; Rejtar, Tomas; Zang, Xin; Giese, Roger; Andreev, Victor; Moskovets, Eugene; Karger, Barry L

    2005-04-01

    The goal of this study was the development of N-terminal tags to improve peptide identification using high-throughput MALDI-TOF/TOF MS. Part 1 of the study was focused on the influence of derivatization on the intensities of MALDI-TOF MS signals of peptides. In part 2, various derivatization approaches for the improvement of peptide fragmentation efficiency in MALDI-TOF/TOF MS are explored. We demonstrate that permanent cation tags, while significantly improving signal intensity in the MS mode, lead to severe suppression of MS/MS fragmentation, making these tags unsuitable for high-throughput MALDI-TOF/TOF MS analysis. In the present work, it was found that labeling with Alexa Fluor 350, a coumarin tag containing a sulfo group, along with guanidation of epsilon-amino groups of Lys, could enhance unimolecular fragmentation of peptides with the formation of a high-intensity y-ion series, while the peptide intensities in the MS mode were not severely affected. LC-MALDI-TOF/TOF MS analysis of tryptic peptides from the SCX fractions of an E. coli lysate revealed improved peptide scores, a doubling of the total number of peptides, and a 30% increase in the number of proteins identified, as a result of labeling. Furthermore, by combining the data from native and labeled samples, confidence in correct identification was increased, as many proteins were identified by different peptides in the native and labeled data sets. Additionally, derivatization was found not to impair chromatographic behavior of peptides. All these factors suggest that labeling with Alexa Fluor 350 is a promising approach to the high-throughput LC-MALDI-TOF/TOF MS analysis of proteomic samples.

  6. Least-Squares Adaptive Control Using Chebyshev Orthogonal Polynomials

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.; Burken, John; Ishihara, Abraham

    2011-01-01

    This paper presents a new adaptive control approach using Chebyshev orthogonal polynomials as basis functions in a least-squares functional approximation. The use of orthogonal basis functions improves the function approximation significantly and enables better convergence of parameter estimates. Flight control simulations demonstrate the effectiveness of the proposed adaptive control approach.

  7. The Gibbs Phenomenon for Series of Orthogonal Polynomials

    ERIC Educational Resources Information Center

    Fay, T. H.; Kloppers, P. Hendrik

    2006-01-01

    This note considers the four classes of orthogonal polynomials--Chebyshev, Hermite, Laguerre, Legendre--and investigates the Gibbs phenomenon at a jump discontinuity for the corresponding orthogonal polynomial series expansions. The perhaps unexpected thing is that the Gibbs constant that arises for each class of polynomials appears to be the same…

  8. Approximate Orthogonal Sparse Embedding for Dimensionality Reduction.

    PubMed

    Lai, Zhihui; Wong, Wai Keung; Xu, Yong; Yang, Jian; Zhang, David

    2016-04-01

    Locally linear embedding (LLE) is one of the most well-known manifold learning methods. As the representative linear extension of LLE, orthogonal neighborhood preserving projection (ONPP) has attracted widespread attention in the field of dimensionality reduction. In this paper, a unified sparse learning framework is proposed by introducing the sparsity or L1-norm learning, which further extends the LLE-based methods to sparse cases. Theoretical connections between the ONPP and the proposed sparse linear embedding are discovered. The optimal sparse embeddings derived from the proposed framework can be computed by iterating the modified elastic net and singular value decomposition. We also show that the proposed model can be viewed as a general model for sparse linear and nonlinear (kernel) subspace learning. Based on this general model, sparse kernel embedding is also proposed for nonlinear sparse feature extraction. Extensive experiments on five databases demonstrate that the proposed sparse learning framework performs better than the existing subspace learning algorithm, particularly in the cases of small sample sizes.

  9. An orthogonal oriented quadrature hexagonal image pyramid

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.; Ahumada, Albert J., Jr.

    1987-01-01

    An image pyramid has been developed with basis functions that are orthogonal, self-similar, and localized in space, spatial frequency, orientation, and phase. The pyramid operates on a hexagonal sample lattice. The set of seven basis functions consist of three even high-pass kernels, three odd high-pass kernels, and one low-pass kernel. The three even kernels are identified when rotated by 60 or 120 deg, and likewise for the odd. The seven basis functions occupy a point and a hexagon of six nearest neighbors on a hexagonal sample lattice. At the lowest level of the pyramid, the input lattice is the image sample lattice. At each higher level, the input lattice is provided by the low-pass coefficients computed at the previous level. At each level, the output is subsampled in such a way as to yield a new hexagonal lattice with a spacing sq rt 7 larger than the previous level, so that the number of coefficients is reduced by a factor of 7 at each level. The relationship between this image code and the processing architecture of the primate visual cortex is discussed.

  10. Analytical modeling of orthogonal spiral structures

    NASA Astrophysics Data System (ADS)

    Santos, Auteliano A.; Hobeck, Jared D.; Inman, Daniel J.

    2016-11-01

    This paper presents the analytical modeling of orthogonal spiral structures (OSS), a promising option for small-scale energy harvesting applications. This unique multi-beam structure is analyzed using a distributed parameter approach with Euler-Bernoulli assumptions. First, an aluminum substrate is evaluated to determine if the proposed design can be used to capture vibration energy in the desired frequency range using a twelve beam OSS. Finite element calculations are used to validate the analytical model. This model is then modified to include the electromechanical effects of a piezoelectric layer added to the aluminum substrate. Lastly, the effects of the beam width and the number of beams is analyzed for a particular surface area of the OSS. Results show that increasing the number of beams causes a reduction in the first natural frequency. From those results, it is possible to conclude that OSS can be used as an alternative to current energy harvesting systems for MEMS applications, allowing the capture of environmental energy in the frequency range of common mechanical systems.

  11. Aeroservoelastic modeling with proper orthogonal decomposition

    NASA Astrophysics Data System (ADS)

    Carlson, Henry A.; Verberg, Rolf; Harris, Charles A.

    2017-02-01

    A physics-based, reduced-order, aeroservoelastic model of an F-18 aircraft has been developed using the method of proper orthogonal decomposition (POD), introduced to the field of fluid mechanics by Lumley. The model is constructed with data from high-dimensional, high-fidelity aeroservoelastic computational fluid dynamics (CFD-ASE) simulations that couple equations of motion of the flow to a modal model of the aircraft structure. Through POD modes, the reduced-order model (ROM) predicts both the structural dynamics and the coupled flow dynamics, offering much more information than typically employed, low-dimensional models based on system identification are capable of providing. ROM accuracy is evaluated through direct comparisons between predictions of the flow and structural dynamics with predictions from the parent, the CFD-ASE model. The computational overhead of the ROM is six orders of magnitude lower than that of the CFD-ASE model—accurately predicting the coupled dynamics from simulations of an F-18 fighter aircraft undergoing flutter testing over a wide range of transonic and supersonic flight speeds on a single processor in 1.073 s.

  12. Remote beating of parallel or orthogonally polarized dual-wavelength optical carriers for 5G millimeter-wave radio-over-fiber link.

    PubMed

    Wang, Huai-Yung; Chi, Yu-Chieh; Lin, Gong-Ru

    2016-08-08

    A novel millimeter-wave radio over fiber (MMW-RoF) link at carrier frequency of 35-GHz is proposed with the use of remotely beating MMW generation from reference master and injected slave colorless laser diode (LD) carriers at orthogonally polarized dual-wavelength injection-locking. The slave colorless LD supports lasing one of the dual-wavelength master modes with orthogonal polarizations, which facilitates the single-mode direct modulation of the quadrature amplitude modulation (QAM) orthogonal frequency division multiplexing (OFDM) data. Such an injected single-carrier encoding and coupled dual-carrier transmission with orthogonal polarization effectively suppresses the cross-heterodyne mode-beating intensity noise, the nonlinear modulation (NLM) and four-wave mixing (FWM) sidemodes during injection locking and fiber transmission. In 25-km single-mode fiber (SMF) based wireline system, the dual-carrier under single-mode encoding provides baseband 24-Gbit/s 64-QAM OFDM transmission with an error vector magnitude (EVM) of 8.8%, a bit error rate (BER) of 3.7 × 10-3, a power penalty of <1.5 dB. After remotely self-beating for wireless transmission, the beat MMW carrier at 35 GHz can deliver the passband 16-QAM OFDM at 4 Gbit/s to show corresponding EVM and BER of 15.5% and 1.4 × 10-3, respectively, after 25-km SMF and 1.6-m free-space transmission.

  13. Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry

    PubMed Central

    Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

    2011-01-01

    In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000–15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert’s visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition. PMID:21544266

  14. MALDI linear TOF mass spectrometry of PEGylated (glyco)proteins.

    PubMed

    Seyfried, Birgit K; Siekmann, Jürgen; Belgacem, Omar; Wenzel, Ryan J; Turecek, Peter L; Allmaier, Günter

    2010-06-01

    PEGylation of proteins is a fast growing field in biotechnology and pharmaceutical sciences owing to its ability to prolong the serum half-life time of recombinant proteins. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) has been shown to be a powerful tool in the analysis of several PEGylated small proteins. Here we present data obtained with a standard secondary electron multiplier (SEM) and a high mass (HM) detector combined with a MALDI linear TOF MS system for the detection of PEGylated (glyco)proteins in the range of 60-600 kDa. Examples of MALDI TOF MS of small (interferon alpha2a), middle (human serum albumin (HSA)) and high molecular mass proteins (coagulation factor VIII and von Willebrand factor (vWF), both heavily glycosylated proteins) are presented. The particular challenge for the analysis was the heterogeneity of the (glyco)proteins in the high molecular weight range in combination with additional PEGylation, which even introduced more heterogeneity and was more challenging for interpretation. Nevertheless, the performance of MALDI linear TOF MS with both detector systems in terms molecular weight and heterogeneity determination depending on the m/z range was superior to the other methods. Although the SEM was able to obtain information about protein PEGylation in the mass range up to 100 kDa (e.g. PEGylated HSA), the HM system was crucial for detection of HM ions (e.g. PEGylated recombinant vWF), which was impossible with the standard SEM.

  15. LC-IM-TOF Instrument Control & Data Visualization Software

    SciTech Connect

    2011-05-12

    Liquid Chromatography-Ion Mobility-time of Flight Instrument Control and Data Visualization software is designed to control instrument voltages for the Ion Mobility drift tube. It collects and stores information collected from the Agilent TOF instrument and analyses/displays the ion intensity information acquired. The software interface can be split into 3 categories -- Instrument Settings/Controls, Data Acquisition, and Viewer. The Instrument Settings/Controls prepares the instrument for Data Acquisition. The Viewer contains common objects that are used by Instrument Settings/Controls and Data Acquisition. Intensity information is collected in 1 nanosec bins and separated by TOF pulses called scans. A collection of scans are stored side by side making up an accumulation. In order for the computer to keep up with the stream of data, 30-50 accumulations are commonly summed into a single frame. A collection of frames makes up an experiment. The Viewer software then takes the experiment and presents the data in several possible ways, each frame can be viewed in TOF bins or m/z (mass to charge ratio). The experiment can be viewed frame by frame, merging several frames, or by viewing the peak chromatogram. The user can zoom into the data, export data, and/or animate frames. Additional features include calibration of the data and even post-processing multiplexed data.

  16. The Fission Programme at the CERN n_TOF Facility

    NASA Astrophysics Data System (ADS)

    Tsinganis, A.; Barbagallo, M.; Berthoumieux, E.; Calviani, M.; Chiaveri, E.; Colonna, N.; Diakaki, M.; Duran, I.; Guerrero, C.; Gunsing, F.; Leal-Cidoncha, E.; Leong, L.-S.; Paradela, C.; Tarrio, D.; Tassan-Got, L.; Vlastou, R.

    Since 2001, the scientific programme of the CERN n_TOF facility has focused mainly on the study of radiative neutron capture reactions, which are of great interest to nuclear astrophysics and on neutron-induced fission reactions, which are of relevance for nuclear technology, as well as essential for the development of theoretical models of fission. In particular, taking advantage of the high instantaneous neutron flux and high energy resolution of the facility, as well as of high-performance detection and acquisition systems, accurate new measurements on several long-lived major and minor actinides, from 232Th to 245Cm, have been performed so far. Data on these isotopes are needed in order to improve the safety and efficiency of conventional reactors, as well as to develop new systems for nuclear energy production and treatment of nuclear waste, such as Generation IV reactors, Accelerator Driven Systems and reactors based on innovative fuel cycles. A review of the most important results on fission cross-sections and fragment properties obtained at n_TOF for a variety of (radioactive) isotopes is presented along with the perspectives arising from the coming on line in the second half of 2014 of a new 19 m flight-path, which will allow n_TOF to expand its measurement capabilities to even more rare or short-lived isotopes, such as 230Th, 232U, 238,240Pu and 244Cm.

  17. Exploratory analysis of TOF-SIMS data from biological surfaces

    NASA Astrophysics Data System (ADS)

    Vaidyanathan, Seetharaman; Fletcher, John S.; Henderson, Alex; Lockyer, Nicholas P.; Vickerman, John C.

    2008-12-01

    The application of multivariate analytical tools enables simplification of TOF-SIMS datasets so that useful information can be extracted from complex spectra and images, especially those that do not give readily interpretable results. There is however a challenge in understanding the outputs from such analyses. The problem is complicated when analysing images, given the additional dimensions in the dataset. Here we demonstrate how the application of simple pre-processing routines can enable the interpretation of TOF-SIMS spectra and images. For the spectral data, TOF-SIMS spectra used to discriminate bacterial isolates associated with urinary tract infection were studied. Using different criteria for picking peaks before carrying out PC-DFA enabled identification of the discriminatory information with greater certainty. For the image data, an air-dried salt stressed bacterial sample, discussed in another paper by us in this issue, was studied. Exploration of the image datasets with and without normalisation prior to multivariate analysis by PCA or MAF resulted in different regions of the image being highlighted by the techniques.

  18. Quantitative Analysis with Heavy Ion E-TOF ERD

    SciTech Connect

    Banks, J.C.; Doyle, B.L.; Font, A. Climent

    1999-07-23

    Heavy ion TOF ERD combined with energy detection (E-TOF-ERD) is a powerful analytical technique taking advantage of the following facts: the scattering cross section is usually very high ({approximately}10{sup {minus}21} cm{sup 2}/sr) compared to regular He RBS ({approximately}10{sup {minus}25} cm{sup 2}/sr), contrary to what happens with the energy resolution in ordinary surface solid barrier detectors, time resolution is almost independent of the atomic mass of the detected element, and the detection in coincidence of time and energy signals allows for the mass separation of overlapping signals with the same energy (or time of flight). Measurements on several oxides have been performed with the E-TOF-ERD set up at Sandia National Laboratories using an incident beam of 10-15 MeV Au. The information on the composition of the sample is obtained from the time domain spectrum, which is converted to energy domain, and then, using existing software codes, the analysis is performed. During the quantification of the results, they have found problems related to the interaction of the beam with the sample and to the tabulated values of the stopping powers for heavy ions.

  19. Spontaneous-Desorption Ionizer for a TOF-MS

    NASA Technical Reports Server (NTRS)

    Schultz, J. Albert

    2006-01-01

    A time-of-flight mass spectrometer (TOF-MS) like the one mentioned in the immediately preceding article has been retrofitted with an ionizer based on a surface spontaneous-desorption process. This ionizer includes an electron multiplier in the form of a microchannel plate (MCP). Relative to an ionizer based on a hot-filament electron source, this ionizer offers advantages of less power consumption and greater mechanical ruggedness. The current density and stability characteristics of the electron emission of this ionizer are similar to those of a filament-based ionizer. In tests of various versions of this ionizer in the TOF-MS, electron currents up to 100 nA were registered. Currents of microamperes or more - great enough to satisfy requirements in most TOFMS applications - could be obtained by use of MCPs different from those used in the tests, albeit at the cost of greater bulk. One drawback of this ionizer is that the gain of the MCP decreases as a function of the charge extracted thus far; the total charge that can be extracted over the operational lifetime is about 1 coulomb. An MCP in the ion-detector portion of the TOF-MS is subject to the same limitation.

  20. Computing the roots of complex orthogonal and kernel polynomials

    SciTech Connect

    Saylor, P.E.; Smolarski, D.C.

    1988-01-01

    A method is presented to compute the roots of complex orthogonal and kernel polynomials. An important application of complex kernel polynomials is the acceleration of iterative methods for the solution of nonsymmetric linear equations. In the real case, the roots of orthogonal polynomials coincide with the eigenvalues of the Jacobi matrix, a symmetric tridiagonal matrix obtained from the defining three-term recurrence relationship for the orthogonal polynomials. In the real case kernel polynomials are orthogonal. The Stieltjes procedure is an algorithm to compute the roots of orthogonal and kernel polynomials bases on these facts. In the complex case, the Jacobi matrix generalizes to a Hessenberg matrix, the eigenvalues of which are roots of either orthogonal or kernel polynomials. The resulting algorithm generalizes the Stieljes procedure. It may not be defined in the case of kernel polynomials, a consequence of the fact that they are orthogonal with respect to a nonpositive bilinear form. (Another consequence is that kernel polynomials need not be of exact degree.) A second algorithm that is always defined is presented for kernel polynomials. Numerical examples are described.

  1. YahO protein as a calibrant for top-down proteomic identification of Shiga toxin using MALDI-TOF-TOF-MS/MS and post-source decay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF-TOF) mass spectrometry is increasingly utilized for rapid top-down proteomic identification of proteins. This identification may involve analysis of either a pure protein or a protein mixture. For analysis of a pure protein...

  2. Rapid Identification of Protein Biomarkers of E. coli O157:H7 by MALDI-TOF-TOF Mass Spectrometry and Top-Down Proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have identified six protein biomarkers from two strains of E. coli O157:H7 and one non-pathogenic E. coli strain by matrix-assisted laser desorption/ionization (MALDI) time-of-flight/time-of-flight tandem mass spectrometry (TOF/TOF-MS/MS) and top-down proteomics. Mature, intact proteins were ext...

  3. Comparison of yttrium-90 quantitative imaging by TOF and non-TOF PET in a phantom of liver selective internal radiotherapy

    NASA Astrophysics Data System (ADS)

    van Elmbt, Larry; Vandenberghe, Stefaan; Walrand, Stephan; Pauwels, Stanislas; Jamar, François

    2011-11-01

    The aim of this study is to determine the feasibility of achieving quantitative measurement in 90Y-microspheres liver selective internal radiotherapy (SIRT) by imaging 90Y with a conventional non-time of flight (TOF) PET device. Instead of the bremsstrahlung x-rays of the β-decay, the low branch of e-- e+ pair production in the 90Y-decay was used. The activity distribution in a phantom-simulated liver SIRT was obtained by direct 90Y-PET imaging. We tested a LYSO TOF PET and two GSO and BGO non-TOF PET scanners using a 3.6-l cylindrical phantom filled with the 90Y solution containing two sets of hot and cold spheres. The best hot contrast was obtained with the LYSO TOF. It was close to the expected value and remained constant, even for short acquisition times. The LYSO non-TOF was about 10% lower. The GSO performed similarly but degraded for shorter times whilst the BGO was the worst with 40% loss. For the cold spheres, the LYSO TOF and the GSO provided the best results, while the LYSO non-TOF and the BGO were the worst. 90Y PET imaging in liver SIRT is achievable with LYSO TOF. Conventional LYSO and GSO show a loss of contrast and require longer acquisition times. BGO imaging is not feasible for dosimetry calculation.

  4. The benefit of combining nLC-MALDI-Orbitrap MS data with nLC-MALDI-TOF/TOF data for proteomic analyses employing elastase.

    PubMed

    Rietschel, Benjamin; Baeumlisberger, Dominic; Arrey, Tabiwang N; Bornemann, Sandra; Rohmer, Marion; Schuerken, Malte; Karas, Michael; Meyer, Bjoern

    2009-11-01

    The recently established coupling of a MALDI-type ion source to a linear ion trap and an orbitrap mass analyzer offers high-accuracy mass measurements compared to common MALDI-TOF/TOF instruments. Contrary to MALDI-TOF/TOF, the fragmentation of peptides in the new hybrid mass spectrometer is less efficient due to the generation of predominantly singly charged ions by the MALDI process. Therefore, data from two MALDI instruments, TOF/TOF and Orbitrap, were combined into a single data set in order to obtain accurate precursor masses as well as superior MS/MS spectra. This study demonstrates that an accurate precursor mass is particularly important for the nLC-MS/MS analyses of less-specific proteolytic digests. A potential gain of approximately one-third additional peptides identifications was theoretically estimated from previously published MALDI-TOF/TOF data. These calculations were verified by the nLC-MS/MS analysis of two elastatically digested proteomes, one cytosolic (Corynebacterium glutamicum) and one membrane (Halobacterium salinarium). Thereby it was discovered that the error distribution of a MALDI-Orbitrap can be significantly improved by applying an easy recalibration strategy. In summary, this study represents an updated workflow for the analysis of less-specific digests using nLC-MALDI.

  5. Polar Plate Theory for Orthogonal Anisotropy

    NASA Technical Reports Server (NTRS)

    Bailey, Michelle D.; Bower, Mark V.

    2000-01-01

    Laminated fiber-reinforced (or filamentary) composites are used today for their high strength-to-weight and stiffness-to-weight ratios. However, because of the anisotropic behavior of composites, determining the response on a macroscopic scale is challenging. This is particularly evident in the evaluation of the governing differential equations of a circular disk with the fibers of the lamina oriented with rectilinear orthogonality. This includes any situation involving a composite plate of circular geometry in which out-of-plane displacements due to load are desired, such as fastener pull through loading of a composite plate. Current analysis techniques use numerical methods with rectilinear coordinate systems to solve problems with circular geometry. These analyses over predict plate stiffness by 20% and underpredict failure by 70%. Consequently, there is a need to transform classical composite plate theory to a polar coordinate system. In order to better analyze structures with circular geometries the classical composite plate equations are transformed into the plate equations for a rectilinearly anisotropic composite in polar coordinates. A composite plate is typically a laminate of fibers in rectilinear directions. Subsequent to the lay-tip the necessary geometry is cut out of a rectangular plate. In a similar manner, the derivation of the plate equation starts with the fundamental definitions of strain, displacement and curvature and incorporates the material property angular dependence into the equilibrium equations for a differential polar element. In the transformed state, the stiffness coefficients are no longer constant, adding to the complexity of the governing differential equations. This paper discusses the new derivation and evaluation of the plate equations for a circular composite disk with orthogonal rectilinear anisotropy. The resultant new three partial differential equations, which describe the circular anisotropic plate, can be used to

  6. A case study of de novo sequence analysis of N-sulfonated peptides by MALDI TOF/TOF mass spectrometry.

    PubMed

    Samyn, Bart; Debyser, Griet; Sergeant, Kjell; Devreese, Bart; Van Beeumen, Jozef

    2004-12-01

    The simplicity and sensitivity of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry have increased its application in recent years. The most common method of "peptide mass fingerprint" analysis often does not provide robust identification. Additional sequence information, obtained by post-source decay or collision induced dissociation, provides additional constraints for database searches. However, de novo sequencing by mass spectrometry is not yet common practice, most likely because of the difficulties associated with the interpretation of high and low energy CID spectra. Success with this type of sequencing requires full sequence coverage and demands better quality spectra than those typically used for data base searching. In this report we show that full-length de novo sequencing is possible using MALDI TOF/TOF analysis. The interpretation of MS/MS data is facilitated by N-terminal sulfonation after protection of lysine side chains (Keough et al., Proc. Natl. Acad. Sci. U.S.A. 1999, 96, 7131-7136). Reliable de novo sequence analysis has been obtained using sub-picomol quantities of peptides and peptide sequences of up to 16 amino acid residues in length have been determined. The simple, predictable fragmentation pattern allows routine de novo interpretation, either manually or using software. Characterization of the complete primary structure of a peptide is often hindered because of differences in fragmentation efficiencies and in specific fragmentation patterns for different peptides. These differences are controlled by various structural parameters including the nature of the residues present. The influence of the presence of internal Pro, acidic and basic residues on the TOF/TOF fragmentation pattern will be discussed, both for underivatized and guanidinated/sulfonated peptides.

  7. Subjective ranking of concert halls substantiated through orthogonal objective parameters.

    PubMed

    Cerdá, Salvador; Giménez, Alicia; Cibrián, Rosa; Girón, Sara; Zamarreño, Teófilo

    2015-02-01

    This paper studies the global subjective assessment, obtained from mean values of the results of surveys addressed to members of the audience of live concerts in Spanish auditoriums, through the mean values of the three orthogonal objective parameters (Tmid, IACCE3, and LEV), expressed in just noticeable differences (JNDs), regarding the best-valued hall. Results show that a linear combination of the relative variations of orthogonal parameters can largely explain the overall perceived quality of the sample. However, the mean values of certain orthogonal parameters are not representative, which shows that an alternative approach to the problem is necessary. Various possibilities are proposed.

  8. A comparative study on detection of organic surface modifiers on mineral grains by TOF-SIMS, VUV SALI TOF-SIMS and VUV SALI with laser desorption

    NASA Astrophysics Data System (ADS)

    Dimov, S. S.; Chryssoulis, S. L.

    2004-06-01

    Results from a comparative study on the detection of organic collectors by TOF-SIMS, vacuum ultraviolet surface analysis by laser ionization with TOF-SIMS detection (VUV SALI TOF-SIMS) and VUV SALI with laser desorption (VUV TOF-LIMS) are reported. The study was carried out on a PHI 7200 TOF-SIMS instrument upgraded with two lasers: one for laser desorption and another one for VUV laser postionization. A systematic analysis of the laser desorption process lead to a set of optimized desorption parameters and desorption of molecules with a controlled level of fragmentation. The recorded spectra of organic collectors by VUV SALI with laser desorption are characterized by strong parent peaks and simpler fragmentation patterns, which allow for easy molecular identification. Advantages and limitations of the three techniques for analysis of organic collectors on mineral grains are discussed.

  9. Secondary metabolite profiling of Curcuma species grown at different locations using GC/TOF and UPLC/Q-TOF MS.

    PubMed

    Lee, Jueun; Jung, Youngae; Shin, Jeoung-Hwa; Kim, Ho Kyoung; Moon, Byeong Cheol; Ryu, Do Hyun; Hwang, Geum-Sook

    2014-07-04

    Curcuma, a genus of rhizomatous herbaceous species, has been used as a spice, traditional medicine, and natural dye. In this study, the metabolite profile of Curcuma extracts was determined using gas chromatography-time of flight mass spectrometry (GC/TOF MS) and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) to characterize differences between Curcuma aromatica and Curcuma longa grown on the Jeju-do or Jin-do islands, South Korea. Previous studies have performed primary metabolite profiling of Curcuma species grown in different regions using NMR-based metabolomics. This study focused on profiling of secondary metabolites from the hexane extract of Curcuma species. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) plots showed significant differences between the C. aromatica and C. longa metabolite profiles, whereas geographical location had little effect. A t-test was performed to identify statistically significant metabolites, such as terpenoids. Additionally, targeted profiling using UPLC/Q-TOF MS showed that the concentration of curcuminoids differed depending on the plant origin. Based on these results, a combination of GC- and LC-MS allowed us to analyze curcuminoids and terpenoids, the typical bioactive compounds of Curcuma, which can be used to discriminate Curcuma samples according to species or geographical origin.

  10. Generalized Rayleigh and Jacobi Processes and Exceptional Orthogonal Polynomials

    NASA Astrophysics Data System (ADS)

    Chou, C.-I.; Ho, C.-L.

    2013-09-01

    We present four types of infinitely many exactly solvable Fokker-Planck equations, which are related to the newly discovered exceptional orthogonal polynomials. They represent the deformed versions of the Rayleigh process and the Jacobi process.

  11. Systems of Differential Equations with Skew-Symmetric, Orthogonal Matrices

    ERIC Educational Resources Information Center

    Glaister, P.

    2008-01-01

    The solution of a system of linear, inhomogeneous differential equations is discussed. The particular class considered is where the coefficient matrix is skew-symmetric and orthogonal, and where the forcing terms are sinusoidal. More general matrices are also considered.

  12. 13. Credit JTL: Detail, orthogonal view of Egyptian Revivial decorative ...

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

    13. Credit JTL: Detail, orthogonal view of Egyptian Revivial decorative motifs used typically at midpoints of diagonals - Reading-Halls Station Bridge, U.S. Route 220, spanning railroad near Halls Station, Muncy, Lycoming County, PA

  13. Symmetry Groups for Linear Programming Relaxations of Orthogonal Array Problems

    DTIC Science & Technology

    2015-03-26

    Symmetry Groups for Linear Programming Relaxations of Orthogonal Array Problems THESIS MARCH 2015 David M. Arquette, Second Lieutenant, USAF AFIT-ENC...work of the U.S. Government and is not subject to copyright protection in the United States. AFIT-ENC-MS-15-M-003 SYMMETRY GROUPS FOR LINEAR...PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENC-MS-15-M-003 SYMMETRY GROUPS FOR LINEAR PROGRAMMING RELAXATIONS OF ORTHOGONAL ARRAY PROBLEMS David M

  14. Expansion and orthogonalization of measured modes for structure identification

    NASA Technical Reports Server (NTRS)

    Smith, Suzanne Weaver

    1989-01-01

    The purpose was to investigate a new simultaneous expansion/orthogonalization method in comparison with two previously published expansion methods and a widely used orthogonalization technique. Each expansion method uses data from an analytical model of the structure to complete the estimate of the mode shape vectors. Berman and Nagy used Guyan expansion in their work with improving analytical models. In this method, modes are expanded one at a time, producing a set not orthogonal with respect to the mass matrix. Baruch and Bar Itzhack's optimal orthogonalization procedure was used to subsequently adjust the expanded modes. A second expansion technique was presented by O'Callahan, Avitabile, and Reimer and separately by Kammer. Again, modes are expanded individually and orthogonalized after expansion with the same optimal technique as above. Finally, a simultaneous expansion/orthogonalization method was developed from the orthogonal Procrustes problem of computational mathematics. In this method modes are optimally expanded as a set and orthogonal with respect to the mass matrix as a result. Two demonstation problems were selected for the comparison of the methods described. The first problem is an 8 degree of freedom spring-mass problem first presented by Kabe. Several conditions were examined for expansion method including the presence of errors in the measured data and in the analysis models. As a second demonstration problem, data from tests of laboratory scale model truss structures was expanded for system identification. Tests with a complete structure produced a correlated analysis model and the stiffness and mass matrices. Tests of various damaged configurations produced measured data for 6 modes at 14 dof locations.

  15. Using Non-Orthogonal Iris Images for Iris Recognition

    DTIC Science & Technology

    2006-05-05

    geometry, face, voice , and iris. These quantifiable features are measured and stored in a database to be used for automatic recognition . The...U.S.N.A. --- Trident Scholar project report; no. 342 (2006) USING NON-ORTHOGONAL IRIS IMAGES FOR IRIS RECOGNITION by MIDN 1/C Ruth Mary...orthogonal iris images for iris recognition 6. AUTHOR(S) Gaunt, Ruth Mary, 1984- 5. FUNDING NUMBERS 7. PERFORMING ORGANIZATION NAME

  16. Local unitary equivalence of quantum states and simultaneous orthogonal equivalence

    NASA Astrophysics Data System (ADS)

    Jing, Naihuan; Yang, Min; Zhao, Hui

    2016-06-01

    The correspondence between local unitary equivalence of bipartite quantum states and simultaneous orthogonal equivalence is thoroughly investigated and strengthened. It is proved that local unitary equivalence can be studied through simultaneous similarity under projective orthogonal transformations, and four parametrization independent algorithms are proposed to judge when two density matrices on ℂd1 ⊗ ℂd2 are locally unitary equivalent in connection with trace identities, Kronecker pencils, Albert determinants and Smith normal forms.

  17. A few thoughts on proper orthogonal decomposition in turbulence

    NASA Astrophysics Data System (ADS)

    Podvin, Bérengère; Fraigneau, Yann

    2017-02-01

    Proper orthogonal decomposition was originally introduced in turbulence to identify large-scale patterns in turbulent flows. Over the years, several extensions have been formulated in order to strengthen its model-predictive abilities, with limited success in the case of fully developed turbulence. We argue that physics-based insight obtained from the proper orthogonal decomposition structures and other turbulence analysis techniques could lead to significant developments in that respect. Numerical results from channel flow simulations are used to illustrate our conjectures.

  18. Retrospective data-driven respiratory gating for PET using TOF information.

    PubMed

    Mengdie Wang; Ning Guo; Hui Zhang; Elfhakri, Georges; Guangshu Hu; Quanzheng Li

    2015-08-01

    Traditional data-driven respiratory gating method is capable of detecting breathing cycles directly from positron emission tomography (PET) data, but usually fails at low SNR, particularly at low dose PET/CT study. Time-of-flight (TOF) PET has the potential to improve the SNR. In order for TOF information to reduce the statistical noise and boost the performance of respiratory gating, we present a robust data-driven respiratory gating method using TOF information, which retrospectively derived the respiratory signal from the acquired TOF-PET data. The PET data was acquired in list mode format and analyzed in sinogram space. The method was demonstrated with patient datasets acquired on a TOF PET/CT system. Data-driven gating methods by center of mass (COM) and principle component analysis (PCA) algorithm were successfully performed on nonTOF PET and TOF PET dataset. To assess the accuracy of the data-driven respiratory signal, a hardware-based signal was acquired for comparison. The study showed that retrospectively respiratory gating using TOF sinograms has improved the SNR, and outperforms the non-TOF gating under both COM and PCA algorithms.

  19. MONSTER: a TOF Spectrometer for β-delayed Neutron Spectroscopy

    SciTech Connect

    Martínez, T.; Cano-Ott, D.; Castilla, J.; Garcia, A.R.; Marin, J.; Martinez, G.; Mendoza, E.; Santos, C.; Tera, F.J.; Villamarin, D.; Agramunt, J.; Algora, A.; Domingo, C.; Jordan, M.D.; Rubio, B.; Taín, J.L.; Bhattacharya, C.; Banerjee, K.; Bhattacharya, S.; Roy, P.; and others

    2014-06-15

    β-delayed neutron (DN) data, including emission probabilities, Pn, and energy spectrum, play an important role in our understanding of nuclear structure, nuclear astrophysics and nuclear technologies. A MOdular Neutron time-of-flight SpectromeTER (MONSTER) is being built for the measurement of the neutron energy spectra and branching ratios. The TOF spectrometer will consist of one hundred liquid scintillator cells covering a significant solid angle. The MONSTER design has been optimized by using Monte Carlo (MC) techniques. The response function of the MONSTER cell has been characterized with mono-energetic neutron beams and compared to dedicated MC simulations.

  20. [Studies of bacterial typing with MALDI-TOF].

    PubMed

    Culebras, Esther; Alvarez-Buylla, Adela; Jose Artacho Reinoso, M; Antonio Lepe, Jose

    2016-06-01

    MALDI-TOF (matrix-assisted laser desorption ionization time-of-flight) mass spectrometry has emerged as a potential tool for microbial characterization and identification in many microbiology departments. The technology is rapid, sensitive, and relatively inexpensive in terms of both the labour and costs involved. This review provides an overview on its utility for strain typing and epidemiological studies and explains the methodological approaches that can be used both for the performance of the technique and for the analysis of results. Finally, the review summarizes studies on the characterization of distinct bacterial species.

  1. MONSTER: a TOF Spectrometer for β-delayed Neutron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Martínez, T.; Cano-Ott, D.; Castilla, J.; Garcia, A. R.; Marin, J.; Martinez, G.; Mendoza, E.; Santos, C.; Tera, F. J.; Villamarin, D.; Agramunt, J.; Algora, A.; Domingo, C.; Jordan, M. D.; Rubio, B.; Taín, J. L.; Bhattacharya, C.; Banerjee, K.; Bhattacharya, S.; Roy, P.; Meena, J. K.; Kundu, S.; Mukherjee, G.; Ghosh, T. K.; Rana, T. K.; Pandey, R.; Saxena, A.; Behera, B.; Penttilä, H.; Jokinen, A.; Rinta-Antila, S.; Guerrero, C.; Ovejero, M. C.

    2014-06-01

    β-delayed neutron (DN) data, including emission probabilities, Pn, and energy spectrum, play an important role in our understanding of nuclear structure, nuclear astrophysics and nuclear technologies. A MOdular Neutron time-of-flight SpectromeTER (MONSTER) is being built for the measurement of the neutron energy spectra and branching ratios. The TOF spectrometer will consist of one hundred liquid scintillator cells covering a significant solid angle. The MONSTER design has been optimized by using Monte Carlo (MC) techniques. The response function of the MONSTER cell has been characterized with mono-energetic neutron beams and compared to dedicated MC simulations.

  2. Long-distance eye-safe laser TOF camera design

    NASA Astrophysics Data System (ADS)

    Kovalev, Anton V.; Polyakov, Vadim M.; Buchenkov, Vyacheslav A.

    2016-04-01

    We present a new TOF camera design based on a compact actively Q-switched diode pumped solid-state laser operating in 1.5 μm range and a receiver system based on a short wave infrared InGaAs PIN diodes focal plane array with an image intensifier and a special readout integration circuit. The compact camera is capable of depth imaging up to 4 kilometers with 10 frame/s and 1.2 m error. The camera could be applied for airborne and space geodesy location and navigation.

  3. Prototype of time digitizing system for BESIII endcap TOF upgrade

    NASA Astrophysics Data System (ADS)

    Cao, Ping; Sun, Wei-Jia; Ji, Xiao-Lu; Fan, Huan-Huan; Wang, Si-Yu; Liu, Shu-Bin; An, Qi

    2014-04-01

    The prototype of a time digitizing system for the BESIII endcap TOF (ETOF) upgrade is introduced in this paper. The ETOF readout electronics has a distributed architecture. Hit signals from the multi-gap resistive plate chamber (MRPC) are signaled as LVDS by front-end electronics (FEE) and are then sent to the back-end time digitizing system via long shield differential twisted pair cables. The ETOF digitizing system consists of two VME crates, each of which contains modules for time digitization, clock, trigger, fast control, etc. The time digitizing module (TDIG) of this prototype can support up to 72 electrical channels for hit information measurement. The fast control (FCTL) module can operate in barrel or endcap mode. The barrel FCTL fans out fast control signals from the trigger system to the endcap FCTLs, merges data from the endcaps and then transfers to the trigger system. Without modifying the barrel TOF (BTOF) structure, this time digitizing architecture benefits from improved ETOF performance without degrading the BTOF performance. Lab experiments show that the time resolution of this digitizing system can be lower than 20 ps, and the data throughput to the DAQ can be about 92 Mbps. Beam experiments show that the total time resolution can be lower than 45 ps.

  4. Studies of charge transport in DNA films using the time-of-flight (TOF) technique

    NASA Astrophysics Data System (ADS)

    Yaney, Perry P.; Gorman, Timothy; Ouchen, Fahima; Grote, James G.

    2011-09-01

    Measurements were carried out on salmon DNA-based films, including as-received DNA (molecular weight, MW>2000 kDa) without and with hexacetyltrimethl-ammonium chloride (CTMA) surfactant, and sonicated DNA of MW~200 kDa with CTMA. The test specimens were spin-coated or drop-cast films on ITO-coated quartz slides with a gold charge-collecting electrode. To protect the films from atmospheric influences, the TOF devices were coated with a 200-400 nm polyurethane passivation layer. A quadrupled 20 ns, pulsed Nd:YAG laser with output at 266 nm was used for charge injection. The room temperature photoconductive transients were dispersive to varying degrees with hole mobilities in DNA materials films ranging between 2E-5 to 6E-3 cm2/Vs for fields ranging from 8 to 58 kV/cm. Only hole response was observed in DNA. The dispersive data were analyzed using a simple, quasi-empirical equation for the photocurrent transient data.

  5. Carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool

    NASA Astrophysics Data System (ADS)

    Cai, Yu; Sha, Shuang

    2016-09-01

    This paper proposes a new carrier-interleaved orthogonal multi-electrode multi-carrier resistivity-measurement tool used in a cylindrical borehole environment during oil-based mud drilling processes. The new tool is an orthogonal frequency division multiplexing access-based contactless multi-measurand detection tool. The tool can measure formation resistivity in different azimuthal angles and elevational depths. It can measure many more measurands simultaneously in a specified bandwidth than the legacy frequency division multiplexing multi-measurand tool without a channel-select filter while avoiding inter-carrier interference. The paper also shows that formation resistivity is not sensitive to frequency in certain frequency bands. The average resistivity collected from N subcarriers can increase the measurement of the signal-to-noise ratio (SNR) by N times given no amplitude clipping in the current-injection electrode. If the clipping limit is taken into account, with the phase rotation of each single carrier, the amplitude peak-to-average ratio can be reduced by 3 times, and the SNR can achieve a 9/N times gain over the single-carrier system. The carrier-interleaving technique is also introduced to counter the carrier frequency offset (CFO) effect, where the CFO will cause inter-pad interference. A qualitative analysis and simulations demonstrate that block-interleaving performs better than tone-interleaving when coping with a large CFO. The theoretical analysis also suggests that increasing the subcarrier number can increase the measurement speed or enhance elevational resolution without sacrificing receiver performance. The complex orthogonal multi-pad multi-carrier resistivity logging tool, in which all subcarriers are complex signals, can provide a larger available subcarrier pool than other types of transceivers.

  6. Asymmetric flow field flow fractionation with light scattering detection - an orthogonal sensitivity analysis.

    PubMed

    Galyean, Anne A; Filliben, James J; Holbrook, R David; Vreeland, Wyatt N; Weinberg, Howard S

    2016-11-18

    Asymmetric flow field flow fractionation (AF(4)) has several instrumental factors that may have a direct effect on separation performance. A sensitivity analysis was applied to ascertain the relative importance of AF(4) primary instrument factor settings for the separation of a complex environmental sample. The analysis evaluated the impact of instrumental factors namely, cross flow, ramp time, focus flow, injection volume, and run buffer concentration on the multi-angle light scattering measurement of natural organic matter (NOM) molar mass (MM). A 2((5-1)) orthogonal fractional factorial design was used to minimize analysis time while preserving the accuracy and robustness in the determination of the main effects and interactions between any two instrumental factors. By assuming that separations resulting in smaller MM measurements would be more accurate, the analysis produced a ranked list of effects estimates for factors and interactions of factors based on their relative importance in minimizing the MM. The most important and statistically significant AF(4) instrumental factors were buffer concentration and cross flow. The least important was ramp time. A parallel 2((5-2)) orthogonal fractional factorial design was also employed on five environmental factors for synthetic natural water samples containing silver nanoparticles (NPs), namely: NP concentration, NP size, NOM concentration, specific conductance, and pH. None of the water quality characteristic effects or interactions were found to be significant in minimizing the measured MM; however, the interaction between NP concentration and NP size was an important effect when considering NOM recovery. This work presents a structured approach for the rigorous assessment of AF(4) instrument factors and optimal settings for the separation of complex samples utilizing efficient orthogonal factional factorial design and appropriate graphical analysis.

  7. Inverse spin Hall effect by spin injection

    NASA Astrophysics Data System (ADS)

    Liu, S. Y.; Horing, Norman J. M.; Lei, X. L.

    2007-09-01

    Motivated by a recent experiment [S. O. Valenzuela and M. Tinkham, Nature (London) 442, 176 (2006)], the authors present a quantitative microscopic theory to investigate the inverse spin-Hall effect with spin injection into aluminum considering both intrinsic and extrinsic spin-orbit couplings using the orthogonalized-plane-wave method. Their theoretical results are in good agreement with the experimental data. It is also clear that the magnitude of the anomalous Hall resistivity is mainly due to contributions from extrinsic skew scattering.

  8. Application of joint orthogonal bases in compressive sensing ghost image

    NASA Astrophysics Data System (ADS)

    Fan, Xiang; Chen, Yi; Cheng, Zheng-dong; Liang, Zheng-yu; Zhu, Bin

    2016-11-01

    Sparse decomposition is one of the core issue of compressive sensing ghost image. At this stage, traditional methods still have the problems of poor sparsity and low reconstruction accuracy, such as discrete fourier transform and discrete cosine transform. In order to solve these problems, joint orthogonal bases transform is proposed to optimize ghost imaging. First, introduce the principle of compressive sensing ghost imaging and point out that sparsity is related to the minimum sample data required for imaging. Then, analyze the development and principle of joint orthogonal bases in detail and find out it can use less nonzero coefficients to reach the same identification effect as other methods. So, joint orthogonal bases transform is able to provide the sparsest representation. Finally, the experimental setup is built in order to verify simulation results. Experimental results indicate that the PSNR of joint orthogonal bases is much higher than traditional methods by using same sample data in compressive sensing ghost image.Therefore, joint orthogonal bases transform can realize better imaging quality under less sample data, which can satisfy the system requirements of convenience and rapid speed in ghost image.

  9. Sodiation as a tool for enhancing the diagnostic value of MALDI-TOF/TOF-MS spectra of complex astaxanthin ester mixtures from Haematococcus pluvialis.

    PubMed

    Weesepoel, Yannick; Vincken, Jean-Paul; Pop, Raluca Maria; Liu, Kun; Gruppen, Harry

    2013-07-01

    The microalga Haematococcus pluvialis produces the pigment astaxanthin mainly in esterified form with a multitude of fatty acids, which results in a complex mixture of carotenol mono- and diesters. For rapid fingerprinting of these esters, matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF/TOF-MS) might be an alternative to traditional chromatographic separation combined with MS. Investigation of ionization and fragmentation of astaxanthin mono- and diester palmitate standards in MALDI-TOF/TOF-MS showed that sodium adduct parent masses [M + Na](+) gave much simpler MS(2) spectra than radical / protonated [M](+●) / [M + H](+) parents. [M + Na](+) fragments yielded diagnostic polyene-specific eliminations and fatty acid neutral losses, whereas [M](+●) / [M + H](+) fragmentation resulted in a multitude of non-diagnostic daughters. For diesters, a benzonium fragment, formed by polyene elimination, was required for identification of the second fatty acid attached to the astaxanthin backbone. Parents were forced into [M + Na](+) ionization by addition of sodium acetate, and best signal-to-noise ratios were obtained in the 0.1 to 1.0 mM range. This method was applied to fingerprinting astaxanthin esters in a crude H. pluvialis extract. Prior to MALDI-TOF/TOF-MS, the extract was fractionated by normal phase Flash chromatography to obtain fractions enriched in mono- and diesters and to remove pheophytin a, which compromised monoester signals. All 12 types of all-trans esterified esters found in LC were identified with MALDI-TOF/TOF-MS, with the exception of two minor monoesters.

  10. Complementary b/y fragment ion pairs from post-source decay of metastable YahO for calibration of MALDI-TOF-TOF-MS/MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Complementary b/y fragment ion pairs from post-source decay (PSD) of metastable YahO protein ion were evaluated for use in the calibration of MALDI-TOF-TOF for tandem mass spectrometry (MS/MS). The yahO gene from pathogenic Escherichia coli O157:H7 strain EDL933 was cloned into a pBAD18 plasmid vect...

  11. Identification of citrullinated peptides in the synovial fluid of patients with rheumatoid arthritis using LC-MALDI-TOF/TOF.

    PubMed

    Wang, Fei; Chen, Fang-Fang; Gao, Wen-Bo; Wang, Hai-Yong; Zhao, Ning-Wei; Xu, Min; Gao, De-Yu; Yu, Wei; Yan, Xiao-Ling; Zhao, Jian-Ning; Li, Xiao-Jun

    2016-09-01

    The objective of the study is to investigate potential citrullinated autoantigens as targets of anti-citrullinated protein antibodies (ACPAs) response in synovial fluids (SFs) of patients with rheumatoid arthritis (RA). SFs from six RA patients and six osteoarthritis (OA) patients as controls were collected. The citrullinated proteins in SFs were extracted by immunoprecipitation with rabbit anti-citrulline antibodies. Matrix-assisted laser desorption/ionization time of flight mass spectrometry/time of flight mass spectrometry (MALDI-TOF/TOF) mass spectrometry was subsequently performed to discover a characteristic neutral loss to finally determine citrullinated autoantigens. A total of 182 citrullinated peptides and 200 citrullinated sites were identified in RA SFs, while 3 citrullinated peptides and 4 citrullinated sites were identified in OA SFs. The 182 citrullinated peptides from RA SFs and the 3 citrullinated peptides from OA SFs were derived from 83 and 3 autoantigens, respectively. Eighty-three autoantigens except protein-arginine deiminase type-2 (PADI2) and protein-arginine deiminase type-2 (PADI4) were over-citrullinated compared with controls, and the citrullinated sites of PADI2 and PADI4 were different in two groups. Interestingly, citrullinated histone H3.3 (H3F3A) was found in OA controls, but not in RA groups. The differential citrullinated proteins identified in RA SFs suggested potential autoantigens were targeted for ACPAs response and might contribute to the induction and perpetuation of complement activation and joint inflammation in RA.

  12. MALDI-TOF/TOF Mass Spectrometric Determination and Antioxidative Activity of Purified Phosphatidylcholine Fractions from Shrimp Species.

    PubMed

    Zhou, Li; Wang, Yan; Wang, Xiaolin; Liang, Yi; Huang, Zheng; Zeng, Xiaoxiong

    2017-02-15

    Purification, characterization, and antioxidative activity in vitro of shrimp phosphatidylcholines (PCs) were investigated. The molecular structures of shrimp PCs were determined by MALDI-TOF/TOF MS. The MS(2) fragments produced from protonated PC precursors and sodiated PC precursors were identified. The specific fragments including [M + Na - trimethylamine](+), [M + Na - 205](+), [M + Na - RCOOH - trimethylamine](+), and [M + H - RCOOH - trimethylamine](+) could distinguish the precursor type to confirm PC molecular structures. The antioxidative activities of purified shrimp PC fractions were evaluated by assay of DPPH free radical scavenging activity, and their effects on the oxidative stability of camellia oil were measured by monitoring changes in the peroxide value assay during oxidation. The PC fractions from Penaeus chinesis and Macrobranchium nipponense showed stronger antioxidative activities than those of other species. All of the shrimp PCs at 0.2% (w/w) improved the oxidative stability of camellia oil significantly (P < 0.05) compared to controls. The experimental findings suggest that shrimp PCs might be a valuable source of natural antioxidants for edible oils or other food dispersions.

  13. Rapid typing of Mannheimia haemolytica major genotypes 1 and 2 using MALDI-TOF mass spectrometry.

    PubMed

    Loy, John Dustin; Clawson, Michael L

    2017-05-01

    Genotype 2M. haemolytica predominantly associate over genotype 1 with the lungs of cattle with respiratory disease and ICEs containing antimicrobial resistance genes. Distinct protein masses were detected by MALDI-TOF MS between genotype 1 and 2 strains. MALDI-TOF MS could rapidly differentiate genotype 2 strains in veterinary diagnostic laboratories.

  14. MALDI-TOF MS of Trichoderma: A model system for the identification of microfungi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This investigation aimed to assess whether MALDI-TOF MS analysis of proteomics could be applied to the study of Trichoderma, a fungal genus selected because it includes many species and is phylogenetically well defined. We also investigated whether MALDI-TOF MS analysis of proteomics would reveal ap...

  15. TOF-SIMS Analysis of Red Color Inks of Writing and Printing Tools on Questioned Documents.

    PubMed

    Lee, Jihye; Nam, Yun Sik; Min, Jisook; Lee, Kang-Bong; Lee, Yeonhee

    2016-05-01

    Time-of-flight secondary ion mass spectrometry (TOF-SIMS) is a well-established surface technique that provides both elemental and molecular information from several monolayers of a sample surface while also allowing depth profiling or image mapping to be performed. Static TOF-SIMS with improved performances has expanded the application of TOF-SIMS to the study of a variety of organic, polymeric, biological, archaeological, and forensic materials. In forensic investigation, the use of a minimal sample for the analysis is preferable. Although the TOF-SIMS technique is destructive, the probing beams have microsized diameters so that only small portion of the questioned sample is necessary for the analysis, leaving the rest available for other analyses. In this study, TOF-SIMS and attenuated total reflectance Fourier transform infrared (ATR-FTIR) were applied to the analysis of several different pen inks, red sealing inks, and printed patterns on paper. The overlapping areas of ballpoint pen writing, red seal stamping, and laser printing in a document were investigated to identify the sequence of recording. The sequence relations for various cases were determined from the TOF-SIMS mapping image and the depth profile. TOF-SIMS images were also used to investigate numbers or characters altered with two different red pens. TOF-SIMS was successfully used to determine the sequence of intersecting lines and the forged numbers on the paper.

  16. Rapid typing of Mannheimia haemolytica major genotypes 1 and 2 using MALDI-TOF mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genotype 2 M. haemolytica predominantly associate over genotype 1 with the lungs of cattle with respiratory disease and ICEs containing antimicrobial resistance genes. Distinct protein masses were detected by MALDI-TOF MS between genotype 1 and 2 strains. MALDI-TOF MS could rapidly differentiate ge...

  17. Simultaneous expansion and orthogonalization of measured modes for structure identification

    NASA Technical Reports Server (NTRS)

    Smith, Suzanne Weaver; Beattie, Christopher A.

    1990-01-01

    Tests of large structures on-orbit will be performed with measurements at a relatively few structure points. Values for the unmeasured degrees of freedom (dofs) can be estimated based on measured dofs and analytical model dynamic information. These 'expanded' mode shapes are useful for optimal-update identification and damage location as well as test/analysis correlation. A new method of expansion for test mode shape vectors is developed from the orthogonal Procrustes problem from computational linear algebra. A subspace defined by the set of measured dofs is compared to a subspace defined by mode shapes from an analytical model of the structure. The method simultaneously expands and orthogonalizes the mode shape vectors. Two demonstration problems are used to compare the new method to current expansion techniques. One demonstration uses test data from a laboratory scale-model truss structure. Performance of the new method is comparable or superior to that of the previous expansion methods which require separate orthogonalization.

  18. Locally indistinguishable orthogonal product bases in arbitrary bipartite quantum system

    PubMed Central

    Xu, Guang-Bao; Yang, Ying-Hui; Wen, Qiao-Yan; Qin, Su-Juan; Gao, Fei

    2016-01-01

    As we know, unextendible product basis (UPB) is an incomplete basis whose members cannot be perfectly distinguished by local operations and classical communication. However, very little is known about those incomplete and locally indistinguishable product bases that are not UPBs. In this paper, we first construct a series of orthogonal product bases that are completable but not locally distinguishable in a general m ⊗ n (m ≥ 3 and n ≥ 3) quantum system. In particular, we give so far the smallest number of locally indistinguishable states of a completable orthogonal product basis in arbitrary quantum systems. Furthermore, we construct a series of small and locally indistinguishable orthogonal product bases in m ⊗ n (m ≥ 3 and n ≥ 3). All the results lead to a better understanding of the structures of locally indistinguishable product bases in arbitrary bipartite quantum system. PMID:27503634

  19. Positroid stratification of orthogonal Grassmannian and ABJM amplitudes

    NASA Astrophysics Data System (ADS)

    Kim, Joonho; Lee, Sangmin

    2014-09-01

    A novel understanding of scattering amplitudes in terms of on-shell diagrams and positive Grassmannian has been recently established for four dimensional Yang-Mills theories and three dimensional Chern-Simons theories of ABJM type. We give a detailed construction of the positroid stratification of orthogonal Grassmannian relevant for ABJM amplitudes. On-shell diagrams are classified by pairing of external particles. We introduce a combinatorial aid called `OG tableaux' and map each equivalence class of on-shell diagrams to a unique tableau. The on-shell diagrams related to each other through BCFW bridging are naturally grouped by the OG tableaux. Introducing suitably ordered BCFW bridges and positive coordinates, we construct the complete coordinate charts to cover the entire positive orthogonal Grassmannian for arbitrary number of external particles. The graded counting of OG tableaux suggests that the positive orthogonal Grassmannian constitutes a combinatorial polytope.

  20. Investigation of formation mechanisms of chips in orthogonal cutting process

    NASA Astrophysics Data System (ADS)

    Ma, W.

    2012-08-01

    This work investigates the formation mechanisms of chips in orthogonal cutting of mild steel and the transformation conditions between various morphology chips. It is supposed that the modeling material follows the Johnson-Cook constitutive model. In orthogonal cutting process, both the plastic flow and the instability behaviors of chip materials are caused by the plane strain loadings. Therefore, the general instability behaviors of materials in plane strain state are first analyzed with linear perturbation method and a universal instability criterion is established. Based on the analytical results, the formation mechanisms of chips and the transformation conditions between continuous and serrated chips are further studied by instability phase diagram method. The results show that the chip formation strongly depends on the intensity ratios between shear and normal stresses. The ratios of dissipative rates of plastic work done by compression and shear stresses govern the transformation from continuous to serrated chips. These results are verified by the numerical simulations on the orthogonal cutting process.

  1. National Ignition Facility (NIF) Neutron time-of-flight (nTOF) Measurements

    SciTech Connect

    Lerche, R A; Glebov, V Y; Moran, M J; McNaney, J M; Kilkenny, J D; Eckart, M; Zacharias, R A; Haslam, J J; Clancy, T J; Yeoman, M F; Warwas, D P; Sangster, T C; Stoeckl, C; Knauer, J; Horsfield, C J

    2010-05-13

    The first three of eighteen neutron time-of-flight (nTOF) channels have been installed at the National Ignition Facility (NIF). The role of these detectors includes yield, temperature, and bang time measurements. This article focuses on nTOF data analysis and quality of results obtained for the first set of experiments to use all 192 NIF beams. Targets produced up to 2 x 10{sup 10} 2.45-MeV neutrons for initial testing of the nTOF detectors. Differences in neutron scattering at the OMEGA laser facility where the detectors were calibrated and at NIF result in different response functions at the two facilities. Monte Carlo modeling shows this difference. The nTOF performance on these early experiments indicates the nTOF system with its full complement of detectors should perform well in future measurements of yield, temperature, and bang time.

  2. Effect of process parameters on cavity pressure in injection molding

    NASA Astrophysics Data System (ADS)

    Wang, Quan; Zhen, Mengxiang; Wu, Zhenghuan; Cai, Yujun

    2017-03-01

    In this study, an experimental work is performed on the effect of injection molding parameters on the polymer pressure inside the mold cavity. Different process parameters of the injection molding are considered during the experimental work (packing pressure, packing time, injection pressure, mold temperature, and melt temperature). A set analyses are carried out by combining the process parameters based on the L16(45)Taguchi orthogonal design. The cavity pressure is measured with time by using Kistler pressure sensor at different injection molding cycles. The results show the packing pressure is significant factor of affecting the maximum of diverse spline cavity pressure. The results obtained specify well the developing of the cavity pressure inside the mold cavity during the injection molding cycles.

  3. Modelling Trends in Ordered Correspondence Analysis Using Orthogonal Polynomials.

    PubMed

    Lombardo, Rosaria; Beh, Eric J; Kroonenberg, Pieter M

    2016-06-01

    The core of the paper consists of the treatment of two special decompositions for correspondence analysis of two-way ordered contingency tables: the bivariate moment decomposition and the hybrid decomposition, both using orthogonal polynomials rather than the commonly used singular vectors. To this end, we will detail and explain the basic characteristics of a particular set of orthogonal polynomials, called Emerson polynomials. It is shown that such polynomials, when used as bases for the row and/or column spaces, can enhance the interpretations via linear, quadratic and higher-order moments of the ordered categories. To aid such interpretations, we propose a new type of graphical display-the polynomial biplot.

  4. Post-functionalization of polymers via orthogonal ligation chemistry.

    PubMed

    Goldmann, Anja S; Glassner, Mathias; Inglis, Andrew J; Barner-Kowollik, Christopher

    2013-05-27

    The establishment of advanced living/controlled polymerization protocols allows for engineering synthetic polymers in a precise fashion. Combining advanced living/controlled polymerization techniques with highly efficient coupling chemistries facilitates quantitative, modular, and orthogonal functionalization of synthetic polymer strands at their chain termini as well as side-chain functionalization. The review highlights the current status of selected post-functionalization techniques of polymers via orthogonal ligation chemistries, major characteristics of the specific transformation chemistry, as well as the characterization of the products.

  5. Uniform Asymptotics of Orthogonal Polynomials Arising from Coherent States

    NASA Astrophysics Data System (ADS)

    Dai, Dan; Hu, Weiying; Wang, Xiang-Sheng

    2015-08-01

    In this paper, we study a family of orthogonal polynomials {φ_n(z)} arising from nonlinear coherent states in quantum optics. Based on the three-term recurrence relation only, we obtain a uniform asymptotic expansion of φ_n(z) as the polynomial degree n tends to infinity. Our asymptotic results suggest that the weight function associated with the polynomials has an unusual singularity, which has never appeared for orthogonal polynomials in the Askey scheme. Our main technique is the Wang and Wong's difference equation method. In addition, the limiting zero distribution of the polynomials φ_n(z) is provided.

  6. An online incremental orthogonal component analysis method for dimensionality reduction.

    PubMed

    Zhu, Tao; Xu, Ye; Shen, Furao; Zhao, Jinxi

    2017-01-01

    In this paper, we introduce a fast linear dimensionality reduction method named incremental orthogonal component analysis (IOCA). IOCA is designed to automatically extract desired orthogonal components (OCs) in an online environment. The OCs and the low-dimensional representations of original data are obtained with only one pass through the entire dataset. Without solving matrix eigenproblem or matrix inversion problem, IOCA learns incrementally from continuous data stream with low computational cost. By proposing an adaptive threshold policy, IOCA is able to automatically determine the dimension of feature subspace. Meanwhile, the quality of the learned OCs is guaranteed. The analysis and experiments demonstrate that IOCA is simple, but efficient and effective.

  7. Empirical orthogonal functions and normal modes. [for atmospheric data studies

    NASA Technical Reports Server (NTRS)

    North, G. R.

    1984-01-01

    An attempt to provide physical insight into the empirical orthogonal function (EOF) representation of data fields by the study of fields generated by linear stochastic models is presented in this paper. In a large class of these models, the EOFs at individual Fourier frequencies coincide with the orthogonal mechanical modes of the system - provided they exist. The precise mathematical criteria for this coincidence are derived and a physical interpretation is provided. A scheme possibly useful in forecasting is formally constructed for representing any stochastic field by a linear Hermitian model forced by noise.

  8. Multielement analysis of interplanetary dust particles using TOF-SIMS

    NASA Technical Reports Server (NTRS)

    Stephan, T.; Kloeck, W.; Jessberger, E. K.; Rulle, H.; Zehnpfenning, J.

    1993-01-01

    Sections of three stratospheric particles (U2015G1, W7029*A27, and L2005P9) were analyzed with TOF-SIMS (Time Of Flight-Secondary Ion Mass Spectrometry) continuing our efforts to investigate the element distribution in interplanetary dust particles (IDP's) with high lateral resolution (approximately 0.2 micron), to examine possible atmospheric contamination effects, and to further explore the abilities of this technique for element analysis of small samples. The samples, previously investigated with SXRF (synchrotron X-ray fluorescence analysis), are highly enriched in Br (Br/Fe: 59 x CI, 9.2 x CI, and 116 x CI, respectively). U2015G1 is the IDP with the by far highest Zn/Fe-ratio (81 x CI) ever reported in chondritic particles.

  9. A MRPC prototype for SOLID-TOF in Jlab

    SciTech Connect

    Wang, Y; Wang, J; Gonzalez-Diaz, D; Chen, H; Chen, J; Li, Y; Camsonne, A; Chen, J -P; Gao, H; Meziane, M

    2013-03-01

    A prototype of Multi-gap Resistive Plate Chamber (MRPC) for the future SoLID time of flight system at JLab has been developed. The counter, trapezoidal in shape, is assembled with the newly developed low-resistive Chinese glass. It has 10 × 0.25 mm gas gaps and 11 readout strips of different lengths. The strip width is 2.5 cm with a strip-to-strip interval of 3 mm. Preliminary tests performed with cosmic-rays showed an efficiency higher than 95% and a time resolution around 50 ps. Results under diffuse/uniform irradiation performed at JLab with scattered high energy electrons showed a time resolution of 70–80 ps and over-95% efficiency up to an incoming flux of 15 kHz/cm{sup 2}. These performances meet the requirements of the new time of flight system SoLID-TOF.

  10. Epidural Injections for Spinal Pain

    MedlinePlus

    ... Physician Resources Professions Site Index A-Z Epidural Injections An epidural injection provides temporary or prolonged relief ... limitations of Epidural Injection? What is an Epidural Injection? An epidural injection is an injection of medication ...

  11. Applications of a matrix-assisted laser desorption/ionization orthogonal time-of-flight mass spectrometer. l. Metastable decay and collision-induced dissociation for sequencing peptides.

    PubMed

    Ackloo, Suzanne; Loboda, Alexandre

    2005-01-01

    The use of a high-performance orthogonal time-of-flight (o-TOF) mass spectrometer for sequence analysis is described. The mass spectrometer is equipped with a matrix-assisted laser desorption/ionization (MALDI) source that operates at elevated pressure, 0.01-1 Torr. Ion fragmentation is controlled by varying the pressure of the buffer gas, the laser energy, the voltage difference between the MALDI target and the adjacent sampling cone, and between the cone and the quadrupole ion guide. The peptides were analyzed under optimal ionization conditions to obtain their molecular mass, and under conditions that promote ion dissociation via metastable decomposition or collision-induced dissociation (CID). The fragmentation spectra were used to obtain sequence information. Ion dissociation was promoted via three configurations of the ionization parameters. All methods yielded sequencing-grade b- and y-type ions. Two binary mixtures of peptides were used to demonstrate that: (1) external calibration provides a standard deviation (sigma) of 4 ppm with a mode of 9 ppm; and (2) that peptides with molecular masses that differ by a factor of two may be independently fragmented by appropriately choosing the CID energy and the low-mass cut-off. Analyses of tryptic digests employed liquid chromatography (LC), deposition of the eluant on a target, and finally MALDI-TOF mass spectrometry. The mass fingerprint and the (partial) sequence of the tryptic peptides were matched to their precursor protein via database searches.

  12. Response Surface Model Building Using Orthogonal Arrays for Computer Experiments

    NASA Technical Reports Server (NTRS)

    Unal, Resit; Braun, Robert D.; Moore, Arlene A.; Lepsch, Roger A.

    1997-01-01

    This study investigates response surface methods for computer experiments and discusses some of the approaches available. Orthogonal arrays constructed for computer experiments are studied and an example application to a technology selection and optimization study for a reusable launch vehicle is presented.

  13. A four-component organogel based on orthogonal chemical interactions.

    PubMed

    Luisier, Nicolas; Schenk, Kurt; Severin, Kay

    2014-09-14

    A thermoresponsive organogel was obtained by orthogonal assembly of four compounds using dynamic covalent boronate ester and imine bonds, as well as dative boron-nitrogen bonds. It is shown that the gel state can be disrupted or reinforced by chemicals which undergo exchange reactions with the gel components.

  14. Orthogonality criterion for banishing hydrino states from standard quantum mechanics

    NASA Astrophysics Data System (ADS)

    de Castro, Antonio S.

    2007-10-01

    Orthogonality criterion is used to shown in a very simple and general way that anomalous bound-state solutions for the Coulomb potential (hydrino states) do not exist as bona fide solutions of the Schr\\"{o}dinger, Klein-Gordon and Dirac equations.

  15. Application of orthogonal eigenstructure control to flight control design

    NASA Astrophysics Data System (ADS)

    Rastgaar Aagaah, M. A.; Ahmadian, M.; Southward, S. C.

    2008-03-01

    Orthogonal eigenstructure control is used for designing a control law that decouples the dynamic modes of a flying vehicle. Orthogonal eigenstructure control is a feedback control method for linear time invariant multi-input multi-output systems. This method has been recently developed by authors. The advantage of this control method over eigenstructure assignment methods is that there is no need for defining the closed-loop poles or shaping the closed-loop eigenvectors. This method eliminates the error due to the difference between achievable and desirable eigenvectors, by finding vectors orthogonal to the open-loop eigenvectors within the achievable eigenvectors set and replacing the open-loop eigenvectors with them. This method is also applicable to the systems with non-collocated actuators and sensors. Application of this method for designing a flight control law for the lateral directional dynamics of an F-18 HARV is presented, and compared to the results of an eigenstructure assignment method. In this case study, the actuators and sensors are not collocated. It is shown that the application of the orthogonal eigenstructure control results in a more significant dynamic modes decoupling in comparison to the application of the eigenstructure assignment technique.

  16. Orthogonal Projection in Teaching Regression and Financial Mathematics

    ERIC Educational Resources Information Center

    Kachapova, Farida; Kachapov, Ilias

    2010-01-01

    Two improvements in teaching linear regression are suggested. The first is to include the population regression model at the beginning of the topic. The second is to use a geometric approach: to interpret the regression estimate as an orthogonal projection and the estimation error as the distance (which is minimized by the projection). Linear…

  17. Deep learning classifier based on NPCA and orthogonal feature selection

    NASA Astrophysics Data System (ADS)

    Jankowski, Stanisław; Szymański, Zbigniew; Dziomin, Uladzimir; Golovko, Vladimir; Barcz, Aleksy

    2016-09-01

    In this paper the idea of deep learning classifier is developed. The effectiveness of discriminative classifier, as e.g. multilayer perceptron, support vector machine can be improved by adding the data preprocessing blocks: orthogonal feature selection (Gram-Schmidt method) and nonlinear principal component analysis. We present the case study of various structures of deep learning systems (scenarios).

  18. Digital orthogonal receiver for wideband radar based on compressed sensing

    NASA Astrophysics Data System (ADS)

    Hou, Qingkai; Liu, Yang; Chen, Zengping; Su, Shaoying

    2014-10-01

    Digital orthogonal receiver is one of the key techniques in digital receiver of soft radar, and compressed sensing is attracting more and more attention in radar signal processing. In this paper, we propose a CS digital orthogonal receiver for wideband radar which utilizes compressed sampling in the acquisition of radar raw data. In order to reconstruct complex signal from sub-sampled raw data, a novel sparse dictionary is proposed to represent the real-valued radar raw signal sparsely. Using our dictionary and CS algorithm, we can reconstruct the complex-valued radar signal from sub-sampled echoes. Compared with conventional digital orthogonal radar receiver, the architecture of receiver in this paper is more simplified and the sampling frequency of ADC is reduced sharply. At the same time, the range profile can be obtained during the reconstruction, so the matched filtering can be eliminated in the receiver. Some experiments on ISAR imaging based on simulated data prove that the phase information of radar echoes is well reserved in our orthogonal receiver and the whole design is effective for wideband radar.

  19. Wave Propagation in Isotropic Media with Two Orthogonal Fracture Sets

    NASA Astrophysics Data System (ADS)

    Shao, S.; Pyrak-Nolte, L. J.

    2016-10-01

    Orthogonal intersecting fracture sets form fracture networks that affect the hydraulic and mechanical integrity of a rock mass. Interpretation of elastic waves propagated through orthogonal fracture networks is complicated by guided modes that propagate along and between fractures, by multiple internal reflections, as well as by scattering from fracture intersections. The existence of some or all of these potentially overlapping modes depends on local stress fields that can preferentially close or open either one or both sets of fractures. In this study, an acoustic wave front imaging system was used to examine the effect of bi-axial loading conditions on acoustic wave propagation in isotropic media containing two orthogonal fracture sets. From the experimental data, orthogonal intersecting fracture sets support guided waves that depend on fracture spacing and fracture-specific stiffnesses. In addition, fracture intersections have stronger effects on propagating wave fronts than merely the superposition of the effects of two independent fractures because of energy partitioning among transmitted/reflected waves, scattered waves and guided modes. Interpretation of the properties of fractures or fracture sets from seismic measurements must consider non-uniform fracture stiffnesses within and among fracture sets, as well as considering the striking effects of fracture intersections on wave propagation.

  20. Trusted materials using orthogonal testing. 2015 Annual report

    SciTech Connect

    Van Benthem, Mark

    2015-09-01

    The purpose of this project is to prove (or disprove) that a reasonable number of simple tests can be used to provide a unique data signature for materials, changes in which could serve as a harbinger of material deviation, prompting further evaluations. The routine tests are mutually orthogonal to any currently required materials specification tests.

  1. Velocity field calculation for non-orthogonal numerical grids

    SciTech Connect

    Flach, G. P.

    2015-03-01

    Computational grids containing cell faces that do not align with an orthogonal (e.g. Cartesian, cylindrical) coordinate system are routinely encountered in porous-medium numerical simulations. Such grids are referred to in this study as non-orthogonal grids because some cell faces are not orthogonal to a coordinate system plane (e.g. xy, yz or xz plane in Cartesian coordinates). Non-orthogonal grids are routinely encountered at the Savannah River Site in porous-medium flow simulations for Performance Assessments and groundwater flow modeling. Examples include grid lines that conform to the sloping roof of a waste tank or disposal unit in a 2D Performance Assessment simulation, and grid surfaces that conform to undulating stratigraphic surfaces in a 3D groundwater flow model. Particle tracking is routinely performed after a porous-medium numerical flow simulation to better understand the dynamics of the flow field and/or as an approximate indication of the trajectory and timing of advective solute transport. Particle tracks are computed by integrating the velocity field from cell to cell starting from designated seed (starting) positions. An accurate velocity field is required to attain accurate particle tracks. However, many numerical simulation codes report only the volumetric flowrate (e.g. PORFLOW) and/or flux (flowrate divided by area) crossing cell faces. For an orthogonal grid, the normal flux at a cell face is a component of the Darcy velocity vector in the coordinate system, and the pore velocity for particle tracking is attained by dividing by water content. For a non-orthogonal grid, the flux normal to a cell face that lies outside a coordinate plane is not a true component of velocity with respect to the coordinate system. Nonetheless, normal fluxes are often taken as Darcy velocity components, either naively or with accepted approximation. To enable accurate particle tracking or otherwise present an accurate depiction of the velocity field for a non-orthogonal

  2. Investigating the microstructure of keratin extracted from wool: Peptide sequence (MALDI-TOF/TOF) and protein conformation (FTIR)

    NASA Astrophysics Data System (ADS)

    Cardamone, Jeanette M.

    2010-04-01

    Investigations of keratins extracted from wool by reduction hydrolysis and by alkaline hydrolysis showed that their chemical compositions and secondary structures were similar to original wool. The keratin isolates were similar in amino acid, Amides I and II, and secondary structure to each other and to original wool. From SDS-PAGE electrophoresis, keratin isolated by reduction contained protein homologs of molecular weight, ˜40-60 kDa and keratin isolate from alkaline hydrolysis contained peptide fragments of ˜6-8 kDa. MALDI-TOF/TOF spectrometry confirmed that the reduction isolate contained Type II microfibrillar component 7C, hair Type II intermediate filament, Type I microfibrillar 48 kDa component 8C-1, and Type I microfibrillar 47.6 kDa protein homologs which contained alanine, glutamine, glutamic acid, leucine, serine, leucine, and cystine with highest amounts glutamic acid and leucine amino acids. FTIR spectroscopy was applied to examine secondary structure to confirm the content of α-helix/β-sheet/disordered regions for original wool (58.2%/37.9%/3.9%); keratin from reduction (36.7%/50.2%/13.1%); and keratin from alkaline hydrolysis (25.7%/51.8%/22.5%). The higher content of β-sheet secondary structure and intact α-helical conformation characterized these isolates as viable starting materials for chemical modification to form novel bio-based materials useful in industrial formulations and compositions. In particular keratin extracted by reduction with the molecular weight of original wool and the probability of useful mechanical properties can be transformed into stand-alone products of various shapes and forms such as porous foams, sponges, mats, and films for bio-based, adaptable structures.

  3. Absolute Quantification of Rifampicin by MALDI Imaging Mass Spectrometry Using Multiple TOF/TOF Events in a Single Laser Shot.

    PubMed

    Prentice, Boone M; Chumbley, Chad W; Caprioli, Richard M

    2017-01-01

    Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for the visualization of molecular distributions within tissue sections. While providing excellent molecular specificity and spatial information, absolute quantification by MALDI IMS remains challenging. Especially in the low molecular weight region of the spectrum, analysis is complicated by matrix interferences and ionization suppression. Though tandem mass spectrometry (MS/MS) can be used to ensure chemical specificity and improve sensitivity by eliminating chemical noise, typical MALDI MS/MS modalities only scan for a single MS/MS event per laser shot. Herein, we describe TOF/TOF instrumentation that enables multiple fragmentation events to be performed in a single laser shot, allowing the intensity of the analyte to be referenced to the intensity of the internal standard in each laser shot while maintaining the benefits of MS/MS. This approach is illustrated by the quantitative analyses of rifampicin (RIF), an antibiotic used to treat tuberculosis, in pooled human plasma using rifapentine (RPT) as an internal standard. The results show greater than 4-fold improvements in relative standard deviation as well as improved coefficients of determination (R(2)) and accuracy (>93% quality controls, <9% relative errors). This technology is used as an imaging modality to measure absolute RIF concentrations in liver tissue from an animal dosed in vivo. Each microspot in the quantitative image measures the local RIF concentration in the tissue section, providing absolute pixel-to-pixel quantification from different tissue microenvironments. The average concentration determined by IMS is in agreement with the concentration determined by HPLC-MS/MS, showing a percent difference of 10.6%. Graphical Abstract ᅟ.

  4. Absolute Quantification of Rifampicin by MALDI Imaging Mass Spectrometry Using Multiple TOF/TOF Events in a Single Laser Shot

    NASA Astrophysics Data System (ADS)

    Prentice, Boone M.; Chumbley, Chad W.; Caprioli, Richard M.

    2017-01-01

    Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI IMS) allows for the visualization of molecular distributions within tissue sections. While providing excellent molecular specificity and spatial information, absolute quantification by MALDI IMS remains challenging. Especially in the low molecular weight region of the spectrum, analysis is complicated by matrix interferences and ionization suppression. Though tandem mass spectrometry (MS/MS) can be used to ensure chemical specificity and improve sensitivity by eliminating chemical noise, typical MALDI MS/MS modalities only scan for a single MS/MS event per laser shot. Herein, we describe TOF/TOF instrumentation that enables multiple fragmentation events to be performed in a single laser shot, allowing the intensity of the analyte to be referenced to the intensity of the internal standard in each laser shot while maintaining the benefits of MS/MS. This approach is illustrated by the quantitative analyses of rifampicin (RIF), an antibiotic used to treat tuberculosis, in pooled human plasma using rifapentine (RPT) as an internal standard. The results show greater than 4-fold improvements in relative standard deviation as well as improved coefficients of determination (R2) and accuracy (>93% quality controls, <9% relative errors). This technology is used as an imaging modality to measure absolute RIF concentrations in liver tissue from an animal dosed in vivo. Each microspot in the quantitative image measures the local RIF concentration in the tissue section, providing absolute pixel-to-pixel quantification from different tissue microenvironments. The average concentration determined by IMS is in agreement with the concentration determined by HPLC-MS/MS, showing a percent difference of 10.6%.

  5. Multiplex detection of protein toxins using MALDI-TOF-TOF tandem mass spectrometry: application in unambiguous toxin detection from bioaerosol.

    PubMed

    Alam, Syed Imteyaz; Kumar, Bhoj; Kamboj, Dev Vrat

    2012-12-04

    Protein toxins, such as botulinum neurotoxins (BoNTs), Clostridium perfringens epsilon toxin (ETX), staphylococcal enterotoxin B (SEB), shiga toxin (STX), and plant toxin ricin, are involved in a number of diseases and are considered as potential agents for bioterrorism and warfare. From a bioterrorism and warfare perspective, these agents are likely to cause maximum damage to a civilian or military population through an inhalational route of exposure and aerosol is considered the envisaged mode of delivery. Unambiguous detection of toxin from aerosol is of paramount importance, both for bringing mitigation protocols into operation and for implementation of effective medical countermeasures, in case a "biological cloud" is seen over a population. A multiplex, unambiguous, and qualitative detection of protein toxins is reported here using tandem mass spectrometry with MALDI-TOF-TOF. The methodology involving simple sample processing steps was demonstrated to identify toxins (ETX, Clostridium perfringes phospholipase C, and SEB) from blind spiked samples. The novel directed search approach using a list of unique peptides was used to identify toxins from a complex protein mixture. The bioinformatic analysis of seven protein toxins for elucidation of unique peptides with conservation status across all known sequences provides a high confidence for detecting toxins originating from any geographical location and source organism. Use of tandem MS data with peptide sequence information increases the specificity of the method. A prototype for generation of aerosol using a nebulizer and collection using a cyclone collector was used to provide a proof of concept for unambiguous detection of toxin from aerosol using precursor directed tandem mass spectrometry combined with protein database searching. ETX prototoxin could be detected from aerosol at 0.2 ppb concentration in aerosol.

  6. Charge transport and injection in amorphous organic electronic materials

    NASA Astrophysics Data System (ADS)

    Tse, Shing Chi

    This thesis presents how we use various measuring techniques to study the charge transport and injection in organic electronic materials. Understanding charge transport and injection properties in organic solids is of vital importance for improving performance characteristics of organic electronic devices, including organic-light-emitting diodes (OLEDs), photovoltaic cells (OPVs), and field effect transistors (OFETs). The charge transport properties of amorphous organic materials, commonly used in organic electronic devices, are investigated by the means of carrier mobility measurements. Transient electroluminescence (EL) technique was used to evaluate the electron mobility of an electron transporting material--- tris(8-hydroxyquinoline) aluminum (Alq3). The results are in excellent agreement with independent time-of-flight (TOF) measurements. Then, the effect of dopants on electron transport was also examined. TOF technique was also used to examine the effects of tertiary-butyl (t-Bu) substitutions on anthracene derivatives (ADN). All ADN compounds were found to be ambipolar. As the degree of t-Bu substitution increases, the carrier mobilities decrease progressively. The reduction of carrier mobilities with increasing t-butylation can be attributed to a decrease in the charge-transfer integral or the wavefunction overlap. In addition, from TOF measurements, two naphthylamine-based hole transporters, namely, N,N'-diphenyl-N,N'-bis(1-naphthyl)(1,1'-biphenyl)-4,4'diamine (NPB) and 4,4',4"-tris(n-(2-naphthyl)-n-phenyl-amino)-triphenylamine (2TNATA) were found to possess electron-transporting (ET) abilities. An organic light-emitting diode that employed NPB as the ET material was demonstrated. The electron conducting mechanism of NPB and 2TNATA in relation to the hopping model will be discussed. Furthermore, the ET property of NPB applied in OLEDs will also be examined. Besides transient EL and TOF techniques, we also use dark-injection space-charge-limited current

  7. Chemical Bonding: The Orthogonal Valence-Bond View

    PubMed Central

    Sax, Alexander F.

    2015-01-01

    Chemical bonding is the stabilization of a molecular system by charge- and spin-reorganization processes in chemical reactions. These processes are said to be local, because the number of atoms involved is very small. With multi-configurational self-consistent field (MCSCF) wave functions, these processes can be calculated, but the local information is hidden by the delocalized molecular orbitals (MO) used to construct the wave functions. The transformation of such wave functions into valence bond (VB) wave functions, which are based on localized orbitals, reveals the hidden information; this transformation is called a VB reading of MCSCF wave functions. The two-electron VB wave functions describing the Lewis electron pair that connects two atoms are frequently called covalent or neutral, suggesting that these wave functions describe an electronic situation where two electrons are never located at the same atom; such electronic situations and the wave functions describing them are called ionic. When the distance between two atoms decreases, however, every covalent VB wave function composed of non-orthogonal atomic orbitals changes its character from neutral to ionic. However, this change in the character of conventional VB wave functions is hidden by its mathematical form. Orthogonal VB wave functions composed of orthonormalized orbitals never change their character. When localized fragment orbitals are used instead of atomic orbitals, one can decide which local information is revealed and which remains hidden. In this paper, we analyze four chemical reactions by transforming the MCSCF wave functions into orthogonal VB wave functions; we show how the reactions are influenced by changing the atoms involved or by changing their local symmetry. Using orthogonal instead of non-orthogonal orbitals is not just a technical issue; it also changes the interpretation, revealing the properties of wave functions that remain otherwise undetected. PMID:25906476

  8. Optical design through optimization for rectangular apertures using freeform orthogonal polynomials: a case study

    NASA Astrophysics Data System (ADS)

    Nikolic, Milena; Benítez, Pablo; Narasimhan, Bharathwaj; Grabovickic, Dejan; Liu, Jayao; Miñano, Juan C.

    2016-07-01

    Several applications of freeform optics call for deeper analysis of systems with rectangular apertures. We study the behavior of a freeform mirror system by comparing four orthogonal polynomial surface representations through local optimization. We compare polynomials with different orthogonal areas (rectangular-circular) and different metrics (sag-gradient). Polynomials orthogonal inside a rectangle converge faster or to a better local minimum than those orthogonal inside a circle in the example considered. This is the most likely due to the loss of the good properties of orthogonality when the orthogonality area does not coincide with the surface area used.

  9. MALDI-TOF alone versus MALDI-TOF combined with real-time antimicrobial stewardship interventions on time to optimal antimicrobial therapy in patients with positive blood cultures.

    PubMed

    Beganovic, Maya; Costello, Michael; Wieczorkiewicz, Sarah M

    2017-02-22

    Introduction: Matrix-assisted laser desorption ionization time of flight (MALDI-TOF) decreases time to organism identification and improves clinical and financial outcomes. The purpose of this study was to evaluate the impact of MALDI-TOF alone vs MALDI-TOF combined with real-time, pharmacist-driven, antimicrobial stewardship (AMS) intervention on patient outcomes.Methods: This single-center, pre-post quasi-experimental study evaluated hospitalized patients with positive blood cultures identified via MALDI-TOF combined with prospective AMS intervention, compared to a control cohort with MALDI-TOF identification without AMS intervention. AMS intervention included: real-time MALDI-TOF pharmacist notification, and prospective AMS provider feedback. The primary outcome was time to optimal antimicrobial therapy (TTOT).Results: A total of 252 blood cultures were included for final analysis: 126 in each group. MALDI-TOF + AMS intervention significantly reduced overall TTOT (75.17 vs 43.06 h, p <0.001), Gram + contaminant TTOT (48.21 vs 11.75 h, p <0.001), Gram - infection (GNI) TTOT (71.83 vs 35.98 h, p <0.001), and reduced overall hospital LOS (15.03 vs 9.02 days, p 0.021). TTOT for Gram + infection (GPI) was improved (64.04 vs 41.61 h, p 0.082). For GPI: reduced hospital LOS (14.64 vs 10.31 days, p 0.002) and length of antimicrobial therapy 24.30 vs 18.97 days, p 0.018). For GNI: reduced time to microbiologic clearance (51.13 vs 34.51 h, p <0.001), hospital LOS (15.40 vs 7.90 days, p 0.027), and ICU LOS (5.55 vs 1.19 days, p 0.035).Conclusion: In order to achieve optimal outcomes, rapid identification with MALDI-TOF combined with real-time AMS interventions is more impactful than MALDI-TOF alone.

  10. Beam Injection into RHIC

    NASA Astrophysics Data System (ADS)

    Fischer, W.; Hahn, H.; Mackay, W. W.; Tsoupas, N.

    1997-05-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. We describe the injection zone and its bottlenecks, the application program to steer the beam and the injection kickers. We report on the commissioning of the injection systems and on measurements of the kickers.

  11. TOF Mass Measurements of Very Exotic Nuclides: an Input for Astrophysical Calculations

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, M.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Stolz, A.; Aprahamian, A.; Shapira, D.; Smith, E.; Gupta, S.; Wallace, M.

    2007-10-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. Very exotic nuclei can be accessed by time-of- flight techniques at radioactive beam facilities. The NSCL facility provides a well-suited infrastructure for TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for calculations of the r-process and processes occurring in the crust of accreting neutron stars. Description of the TOF technique, results and future plans related to nuclear astrophysics will be presented.

  12. Quantification in MALDI-TOF mass spectrometry of modified polymers.

    PubMed

    Walterová, Zuzana; Horský, Jiří

    2011-05-05

    MALDI-TOF mass spectrometry quantification is hampered by the poor reproducibility of the signal intensity and by molecular-mass and compositional discrimination. The addition of a suitable compound as an internal standard increases reproducibility and allows a calibration curve to be constructed. The concept was also verified with synthetic polymers but no instructions for practical implementation were given [H. Chen, M. He, J. Pei, H. He, Anal. Chem. 75 (2003) 6531-6535.], even though synthetic polymers are generally non-uniform with respect to molecular mass and composition and access to the polymer of the same molecular mass distribution and composition as that of the quantified one is thus the exception rather than rule. On the other hand, relative quantification of polymers e.g., the content of the precursor polymer in a batch of a modified polymer, is usually sought. In this particular case, the pure precursor is usually available and the modified polymer can serve as an internal standard. However, the calibration curve still cannot be constructed and the use of the internal standard has to be combined with the method of standard addition in which the precursor polymer is added directly to the analyzed sample. The experiments with simulated modified polymers, mixtures of poly(ethylene glycol) (PEG) and poly(ethylene glycol) monomethyl ether (MPEG) of similar molecular-mass distribution, revealed a power dependence of the PEG/MPEG signal-intensity ratio (MS ratio) on the PEG/MPEG concentrations ratio in the mixture (gravimetric ratio). The result was obtained using standard procedures and instrumentation, which means that the basic assumption of the standard-addition method, i.e., the proportionality of the MS and gravimetric ratios, generally cannot be taken for granted. Therefore, the multi-point combined internal-standard standard-addition method was developed and experimentally verified for the quantification of the precursor in modified polymers. In this

  13. Sternal wound infection caused by Gordonia bronchialis: identification by MALDI-TOF MS

    PubMed Central

    Rodriguez-Lozano, Jesús; Pérez-Llantada, Enrique; Agüero, Jesús; Rodríguez-Fernández, Ana; Ruiz de Alegria, Carlos; Martinez-Martinez, Luis

    2016-01-01

    Introduction: Gordonia spp. infections are uncommon. However, a few clinical cases have been reported in the literature, particularly those involving immunocompromised hosts. Advanced microbiology diagnosis techniques, such as matrix-assisted laser desorption ionization-time of flight MS (MALDI-TOF MS), have been recently introduced in clinical microbiology laboratories in order to improve microbial identification, resulting in better patient management. Case presentation: Here, we present a new clinical case of persistent wound infection caused by Gordonia bronchialis in a 64-year-old woman after a mitral valve replacement, using two MALDI-TOF-based systems for identifying this micro-organism. Conclusion: Both MALDI-TOF systems were able to identify Gordonia spp.; thus, providing a useful tool that overcomes the current limitations of phenotypic identification associated with this micro-organism. Although the technique validation deserves additional verification, our study provides guidance about MALDI-TOF as a fast and easy method for Gordonia spp. identification. PMID:28348789

  14. Toward an In Situ Organic and Atomic Microprobe with Laser TOF-MS

    NASA Technical Reports Server (NTRS)

    Brinckerhoff, W. B.; Cornish, T. J.; McEntire, R. W.; Cheng, A. F.; Benson, R. C.

    2000-01-01

    We present details of a new miniature laser time-of-flight mass spectrometer (TOF-MS) with improved resolution and sensitivity, for in situ analysis of elemental, isotopic, and organic/molecular composition.

  15. MALDI-TOF MS meets WGS in a VRE outbreak investigation.

    PubMed

    Schlebusch, S; Price, G R; Gallagher, R L; Horton-Szar, V; Elbourne, L D H; Griffin, P; Venter, D J; Jensen, S O; Van Hal, S J

    2017-03-01

    The use of MALDI-TOF MS (matrix-assisted laser desorption/ ionization-time of flight mass spectrometry) and WGS (whole genome sequencing) has been described for identification and strain relatedness determination. We describe the complementary use of MALDI-TOF MS and WGS in a VRE (vancomycin-resistant enterococci) outbreak investigation, and discuss some of the challenges with defining strain similarity across these two platforms. Although both assays indicated multiple clusters involved in the outbreak of vancomycin resistant Enterococcus faecium isolates from positive blood cultures of four haematology-oncology patients, the small cohort and discrepancies between findings indicate the limitations of MALDI-TOF MS and the cautious interpretation of MALDI-TOF MS dendrograms during outbreaks. For definitive determination of the evolutionary distance between isolates, WGS can be used.

  16. Use of MALDI-TOF MS for Identification of Nontuberculous Mycobacterium Species Isolated from Clinical Specimens

    PubMed Central

    Mediavilla-Gradolph, María Concepción; De Toro-Peinado, Inmaculada; Bermúdez-Ruiz, María Pilar; García-Martínez, María de los Ángeles; Ortega-Torres, María; Montiel Quezel-Guerraz, Natalia; Palop-Borrás, Begoña

    2015-01-01

    The aim of this study was to compare the results obtained for identification by MALDI-TOF of nontuberculous mycobacteria (NTM) isolated in clinical samples with those obtained by GenoType Mycobacterium CM/AS (common mycobacteria/additional species). A total of 66 Mycobacterium isolates from various clinical specimens (mainly respiratory) were tested in this study. They were identified using MALDI-TOF Bruker from strains isolated in Lowenstein, following the recommended protocol of heat inactivation and extraction, and were simultaneously analyzed through hybridization by GenoType Mycobacterium from liquid culture MGIT. Our results showed that identification by MALDI-TOF was correct in 98.4% (65/66) of NTM isolated in our clinical practice (M. avium, M. intracellulare, M. abscessus, M. chelonae, M. fortuitum, M. mucogenicum, M. kansasii, and M. scrofulaceum). MALDI-TOF was found to be an accurate, rapid, and cost-effective system for identification of mycobacteria species. PMID:26106617

  17. Identification of microorganisms grown on chromogenic media by MALDI-TOF MS.

    PubMed

    Lüthje, Petra; Pranada, Arthur B; Carruthers-Lay, Duncan; Desjardins, Marc; Gaillot, Olivier; Wareham, David; Ciesielczuk, Holly; Özenci, Volkan

    2017-05-01

    Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and chromogenic media are widely used in clinical microbiology laboratories to facilitate the rapid selection and identification of pathogens. The aim of this study was to evaluate whether usage of chromogenic media limits the diagnostic performance of MALDI-TOF MS for microbial identification. A total of 386 microorganisms collected and analyzed at five laboratories were included. Isolates were cultured on relevant chromogenic media and non-selective agar plates in parallel and identified using the Bruker MALDI-TOF MS. Among the tested isolates, no misidentification was recorded and there was no medium-related difference in the identification level. However, score values were overall slightly but significantly lower for isolates grown on chromogenic media. In conclusion, the use of chromogenic culture media tested here had no relevant impact on MALDI-TOF MS performance for diagnostic purposes.

  18. [Discrimination of plasticizers and screening of phthalates in polyvinyl chloride using DART-TOF/MS].

    PubMed

    Abe, Yutaka; Yamaguchi, Miku; Mutsuga, Motoh; Hirahara, Yoshichika; Kawamura, Maiko; Kikura-Hanajiri, Ruri; Goda, Yukihiro; Kawamura, Yoko

    2010-01-01

    A technique using a direct analysis in real time (DART) ion source coupled with time of flight/mass spectrometry (TOF/MS) was developed to discriminate plasticizers and to screen phthalates in polyvinyl chloride (PVC). In DART-TOF/MS analysis of 40 plasticizers, the protonated molecular ion, [M+H](+), was detected for most plasticizers, and the molecular weight could be easily predicted. In the analysis of PVC sheets and toys, mass spectra of plasticizers were successfully detected, and accordingly, plasticizers in PVC were easily discriminated. PVC with a phthalates content in excess of 0.1% could be screened accurately according to the DART-TOF/MS ion intensity of phthalates corresponding to the limit of detection or a suitable criterion value. DART-TOF/MS analysis is a simple and rapid technique that is suitable for the discrimination of plasticizers and for screening of phthalates in PVC.

  19. TOF-SIMS analysis of magnetic materials in chum salmon head

    NASA Astrophysics Data System (ADS)

    Yano, Akira; Aoyagi, Satoka

    2008-12-01

    A piece of tissue extracted from a chum salmon Oncorhynchus keta head was measured with time-of-flight secondary ion mass spectrometry (TOF-SIMS) in order to evaluate the distribution and composition of magnetic materials in the tissue, which may concern with geomagnetic navigation of long-distance migrating salmon. Several depositions of iron compounds were detected in the tissue by TOF-SIMS analysis. Comparing with total ion images providing a topological tissue structure, specific distribution of iron ion in the tissue was clearly shown. Higher magnification TOF-SIMS analysis revealed the existence of the aggregations of iron particles. Iron oxide clusters comprising many submicron particles were also detected in the tissue using scanning electron microscopy and X-ray analysis, suggesting the common existence of submicron-scale iron oxides in salmon heads. These results suggest that TOF-SIMS analysis is a valid method to clarify detailed structures and chemical properties of candidate magnetoreceptors in fish heads.

  20. Clusters of Monoisotopic Elements for Calibration in (TOF) Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Kolářová, Lenka; Prokeš, Lubomír; Kučera, Lukáš; Hampl, Aleš; Peňa-Méndez, Eladia; Vaňhara, Petr; Havel, Josef

    2017-03-01

    Precise calibration in TOF MS requires suitable and reliable standards, which are not always available for high masses. We evaluated inorganic clusters of the monoisotopic elements gold and phosphorus (Au n +/Au n - and P n +/P n -) as an alternative to peptides or proteins for the external and internal calibration of mass spectra in various experimental and instrumental scenarios. Monoisotopic gold or phosphorus clusters can be easily generated in situ from suitable precursors by laser desorption/ionization (LDI) or matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Their use offers numerous advantages, including simplicity of preparation, biological inertness, and exact mass determination even at lower mass resolution. We used citrate-stabilized gold nanoparticles to generate gold calibration clusters, and red phosphorus powder to generate phosphorus clusters. Both elements can be added to samples to perform internal calibration up to mass-to-charge ( m/z) 10-15,000 without significantly interfering with the analyte. We demonstrated the use of the gold and phosphorous clusters in the MS analysis of complex biological samples, including microbial standards and total extracts of mouse embryonic fibroblasts. We believe that clusters of monoisotopic elements could be used as generally applicable calibrants for complex biological samples.

  1. Performance of TOF-RPC for the BGOegg experiment

    NASA Astrophysics Data System (ADS)

    Tomida, N.; Tran, N.; Niiyama, M.; Ohnishi, H.; Muramatsu, N.

    2016-11-01

    We constructed a new time-of-flight (TOF) detector consisting of resistive plate chambers (RPCs) to measure particle energy in the BGOegg experiment. The BGOegg-RPC has a unique feature which enables us to cover a large area with a small number of readout channels. For this purpose, we developed the RPC with a strip size of 2.5 cm × 100 cm. The BGOegg-RPC covers an area of 320 cm × 200 cm with only 256 channels of readout electronics. In case of large readout RPCs, an originated signal is distorted and dispersed during propagation. In addition, there happens a signal reflection at the end of the strip. Although we designed the BGOegg-RPC and front-end electronics with minimized signal reflection, a small reflection still remained, deteriorating the resulting time resolution. After establishing calibration and correction methods to improve the performance of the BGOegg-RPC, we obtained the time resolution of σ ~ 60 ps around the central region of strips.

  2. Quantitative determination of Piroxicam by TLC-MALDI TOF MS.

    PubMed

    Crecelius, Anna; Clench, Malcolm R; Richards, Don S; Parr, Vic

    2004-04-01

    A quantitative thin-layer chromatography (TLC)-matrix-assisted laser desorption (MALDI) TOF mass spectrometry (MS) method for the determination of Piroxicam has been developed. Following preliminary experiments three different approaches to the incorporation of the internal standard (Tenoxicam) into the TLC plates were investigated. These were: (a) adding the internal standard to the mobile phase and pre-developing the plate, (b) coating the plate with internal standard by electrospraying prior to matrix application and finally, (c) mixing the internal standard into the matrix solution and electrospraying both. The most successful method was that where the internal standard was pre-developed over the plate. For this method linearity was observed over the range between 400 and 800ng of Piroxicam. The precision was found to be in the range of 1-9% R.S.D. from the average detected value (n = 5), dependent on the amount of analyte on the TLC plate. The proposed method was accurate with +/-2% deviation from the known amount of Piroxicam in the sample spot.

  3. Clusters of Monoisotopic Elements for Calibration in (TOF) Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Kolářová, Lenka; Prokeš, Lubomír; Kučera, Lukáš; Hampl, Aleš; Peňa-Méndez, Eladia; Vaňhara, Petr; Havel, Josef

    2016-12-01

    Precise calibration in TOF MS requires suitable and reliable standards, which are not always available for high masses. We evaluated inorganic clusters of the monoisotopic elements gold and phosphorus (Au n +/Au n - and P n +/P n -) as an alternative to peptides or proteins for the external and internal calibration of mass spectra in various experimental and instrumental scenarios. Monoisotopic gold or phosphorus clusters can be easily generated in situ from suitable precursors by laser desorption/ionization (LDI) or matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Their use offers numerous advantages, including simplicity of preparation, biological inertness, and exact mass determination even at lower mass resolution. We used citrate-stabilized gold nanoparticles to generate gold calibration clusters, and red phosphorus powder to generate phosphorus clusters. Both elements can be added to samples to perform internal calibration up to mass-to-charge (m/z) 10-15,000 without significantly interfering with the analyte. We demonstrated the use of the gold and phosphorous clusters in the MS analysis of complex biological samples, including microbial standards and total extracts of mouse embryonic fibroblasts. We believe that clusters of monoisotopic elements could be used as generally applicable calibrants for complex biological samples.

  4. Clusters of Monoisotopic Elements for Calibration in (TOF) Mass Spectrometry.

    PubMed

    Kolářová, Lenka; Prokeš, Lubomír; Kučera, Lukáš; Hampl, Aleš; Peňa-Méndez, Eladia; Vaňhara, Petr; Havel, Josef

    2017-03-01

    Precise calibration in TOF MS requires suitable and reliable standards, which are not always available for high masses. We evaluated inorganic clusters of the monoisotopic elements gold and phosphorus (Au n(+)/Au n(-) and P n(+)/P n(-)) as an alternative to peptides or proteins for the external and internal calibration of mass spectra in various experimental and instrumental scenarios. Monoisotopic gold or phosphorus clusters can be easily generated in situ from suitable precursors by laser desorption/ionization (LDI) or matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Their use offers numerous advantages, including simplicity of preparation, biological inertness, and exact mass determination even at lower mass resolution. We used citrate-stabilized gold nanoparticles to generate gold calibration clusters, and red phosphorus powder to generate phosphorus clusters. Both elements can be added to samples to perform internal calibration up to mass-to-charge (m/z) 10-15,000 without significantly interfering with the analyte. We demonstrated the use of the gold and phosphorous clusters in the MS analysis of complex biological samples, including microbial standards and total extracts of mouse embryonic fibroblasts. We believe that clusters of monoisotopic elements could be used as generally applicable calibrants for complex biological samples. Graphical Abstract ᅟ.

  5. Entanglement as a resource to distinguish orthogonal product states

    PubMed Central

    Zhang, Zhi-Chao; Gao, Fei; Cao, Tian-Qing; Qin, Su-Juan; Wen, Qiao-Yan

    2016-01-01

    It is known that there are many sets of orthogonal product states which cannot be distinguished perfectly by local operations and classical communication (LOCC). However, these discussions have left the following open question: What entanglement resources are necessary and/or sufficient for this task to be possible with LOCC? In m ⊗ n, certain classes of unextendible product bases (UPB) which can be distinguished perfectly using entanglement as a resource, had been presented in 2008. In this paper, we present protocols which use entanglement more efficiently than teleportation to distinguish some classes of orthogonal product states in m ⊗ n, which are not UPB. For the open question, our results offer rather general insight into why entanglement is useful for such tasks, and present a better understanding of the relationship between entanglement and nonlocality. PMID:27458034

  6. Guide RNA functional modules direct Cas9 activity and orthogonality.

    PubMed

    Briner, Alexandra E; Donohoue, Paul D; Gomaa, Ahmed A; Selle, Kurt; Slorach, Euan M; Nye, Christopher H; Haurwitz, Rachel E; Beisel, Chase L; May, Andrew P; Barrangou, Rodolphe

    2014-10-23

    The RNA-guided Cas9 endonuclease specifically targets and cleaves DNA in a sequence-dependent manner and has been widely used for programmable genome editing. Cas9 activity is dependent on interactions with guide RNAs, and evolutionarily divergent Cas9 nucleases have been shown to work orthogonally. However, the molecular basis of selective Cas9:guide-RNA interactions is poorly understood. Here, we identify and characterize six conserved modules within native crRNA:tracrRNA duplexes and single guide RNAs (sgRNAs) that direct Cas9 endonuclease activity. We show the bulge and nexus are necessary for DNA cleavage and demonstrate that the nexus and hairpins are instrumental in defining orthogonality between systems. In contrast, the crRNA:tracrRNA complementary region can be modified or partially removed. Collectively, our results establish guide RNA features that drive DNA targeting by Cas9 and open new design and engineering avenues for CRISPR technologies.

  7. CVS Decomposition of 3D Homogeneous Turbulence Using Orthogonal Wavelets

    NASA Technical Reports Server (NTRS)

    Farge, Marie; Schneider, Kai; Pellegrino, Giulio; Wray, A. A.; Rogallo, R. S.

    2000-01-01

    This paper compares the filtering used in Coherent Vortex Simulation (CVS) decomposition with an orthogonal wavelet basis, with the Proper Orthogonal Decomposition (POD) or Fourier filtering. Both methods are applied to a field of Direct Numerical Simulation (DNS) data of 3D forced homogeneous isotropic turbulence at microscale Reynolds number R(sub lambda) = 168. We show that, with only 3%N retained modes, CVS filtering separates the coherent vortex tubes from the incoherent background flow. The latter is structureless, has an equipartition energy spectrum, and has a Gaussian velocity probability distribution function (PDF) and an exponential vorticity PDF. On the other hand, the Fourier basis does not extract the coherent vortex tubes cleanly and leaves organized structures in the residual high wavenumber modes whose PDFs are stretched exponentials for both the velocity and the vorticity.

  8. Entanglement as a resource to distinguish orthogonal product states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhi-Chao; Gao, Fei; Cao, Tian-Qing; Qin, Su-Juan; Wen, Qiao-Yan

    2016-07-01

    It is known that there are many sets of orthogonal product states which cannot be distinguished perfectly by local operations and classical communication (LOCC). However, these discussions have left the following open question: What entanglement resources are necessary and/or sufficient for this task to be possible with LOCC? In m ⊗ n, certain classes of unextendible product bases (UPB) which can be distinguished perfectly using entanglement as a resource, had been presented in 2008. In this paper, we present protocols which use entanglement more efficiently than teleportation to distinguish some classes of orthogonal product states in m ⊗ n, which are not UPB. For the open question, our results offer rather general insight into why entanglement is useful for such tasks, and present a better understanding of the relationship between entanglement and nonlocality.

  9. Orthogonally modulated molecular transport junctions for resettable electronic logic gates

    PubMed Central

    Meng, Fanben; Hervault, Yves-Marie; Shao, Qi; Hu, Benhui; Norel, Lucie; Rigaut, Stéphane; Chen, Xiaodong

    2014-01-01

    Individual molecules have been demonstrated to exhibit promising applications as functional components in the fabrication of computing nanocircuits. Based on their advantage in chemical tailorability, many molecular devices with advanced electronic functions have been developed, which can be further modulated by the introduction of external stimuli. Here, orthogonally modulated molecular transport junctions are achieved via chemically fabricated nanogaps functionalized with dithienylethene units bearing organometallic ruthenium fragments. The addressable and stepwise control of molecular isomerization can be repeatedly and reversibly completed with a judicious use of the orthogonal optical and electrochemical stimuli to reach the controllable switching of conductivity between two distinct states. These photo-/electro-cooperative nanodevices can be applied as resettable electronic logic gates for Boolean computing, such as a two-input OR and a three-input AND-OR. The proof-of-concept of such logic gates demonstrates the possibility to develop multifunctional molecular devices by rational chemical design. PMID:24394717

  10. Design of robust differential microphone arrays with orthogonal polynomials.

    PubMed

    Pan, Chao; Benesty, Jacob; Chen, Jingdong

    2015-08-01

    Differential microphone arrays have the potential to be widely deployed in hands-free communication systems thanks to their frequency-invariant beampatterns, high directivity factors, and small apertures. Traditionally, they are designed and implemented in a multistage way with uniform linear geometries. This paper presents an approach to the design of differential microphone arrays with orthogonal polynomials, more specifically with Jacobi polynomials. It first shows how to express the beampatterns as a function of orthogonal polynomials. Then several differential beamformers are derived and their performance depends on the parameters of the Jacobi polynomials. Simulations show the great flexibility of the proposed method in terms of designing any order differential microphone arrays with different beampatterns and controlling white noise gain.

  11. Tracking Lung Tumors in Orthogonal X-Rays

    PubMed Central

    2013-01-01

    This paper presents a computationally very efficient, robust, automatic tracking method that does not require any implanted fiducials for low-contrast tumors. First, it generates a set of motion hypotheses and computes corresponding feature vectors in local windows within orthogonal-axis X-ray images. Then, it fits a regression model that maps features to 3D tumor motions by minimizing geodesic distances on motion manifold. These hypotheses can be jointly generated in 3D to learn a single 3D regression model or in 2D through back projection to learn two 2D models separately. Tumor is tracked by applying regression to the consecutive image pairs while selecting optimal window size at every time. Evaluations are performed on orthogonal X-ray videos of 10 patients. Comparative experimental results demonstrate superior accuracy (~1 pixel average error) and robustness to varying imaging artifacts and noise at the same time. PMID:23986789

  12. Ultrahigh-speed "orthogonal" TDM transmission with an optical Nyquist pulse train.

    PubMed

    Nakazawa, Masataka; Hirooka, Toshihiko; Ruan, Peng; Guan, Pengyu

    2012-01-16

    We propose a novel "orthogonal" TDM transmission scheme using an optical Nyquist pulse that enables us to achieve an ultrahigh data rate and spectral efficiency simultaneously without any intersymbol interference (ISI). We analytically describe the principle of orthogonal TDM, and demonstrate a 160 Gbaud optical orthogonal TDM transmission using 40 GHz optical Nyquist pulses. Tolerance to GVD and the dispersion slope is significantly improved by virtue of the orthogonality, reduced bandwidth, and minimum ISI.

  13. MALDI-TOF typing highlights geographical and fluconazole resistance clusters in Candida glabrata.

    PubMed

    Dhieb, C; Normand, A C; Al-Yasiri, M; Chaker, E; El Euch, D; Vranckx, K; Hendrickx, M; Sadfi, N; Piarroux, R; Ranque, S

    2015-06-01

    Utilizing matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra for Candida glabrata typing would be a cost-effective and easy-to-use alternative to classical DNA-based typing methods. This study aimed to use MALDI-TOF for the typing of C. glabrata clinical isolates from various geographical origins and test its capacity to differentiate between fluconazole-sensitive and -resistant strains.Both microsatellite length polymorphism (MLP) and MALDI-TOF mass spectra of 58 C. glabrata isolates originating from Marseilles (France) and Tunis (Tunisia) as well as collection strains from diverse geographic origins were analyzed. The same analysis was conducted on a subset of C. glabrata isolates that were either susceptible (MIC ≤ 8 mg/l) or resistant (MIC ≥ 64 mg/l) to fluconazole.According to the seminal results, both MALDI-TOF and MLP classifications could highlight C. glabrata population structures associated with either geographical dispersal barriers (p < 10(-5)) or the selection of antifungal drug resistance traits (<10(-5)).In conclusion, MALDI-TOF geographical clustering was congruent with MPL genotyping and highlighted a significant population genetic structure according to fluconazole susceptibility in C. glabrata. Furthermore, although MALDI-TOF and MLP resulted in distinct classifications, MALDI-TOF also classified the isolates with respect to their fluconazole susceptibility profile. Further prospective studies are required to evaluate the capacity of MALDI-TOF typing to investigate C. glabrata infection outbreaks and predict the antifungal susceptibility profile of clinical laboratory isolates.

  14. Robustness of two MALDI-TOF mass spectrometry systems for bacterial identification.

    PubMed

    Carbonnelle, Etienne; Grohs, Patrick; Jacquier, Hervé; Day, Nesrine; Tenza, Sylvie; Dewailly, Alexandra; Vissouarn, Odile; Rottman, Martin; Herrmann, Jean-Louis; Podglajen, Isabelle; Raskine, Laurent

    2012-05-01

    MALDI-TOF-MS systems (Microflex-Bruker Daltonics/BioTyper™ and Axima-Assurance-Shimadzu/SARAMIS-AnagnosTec) were assessed for bacterial identification. Focusing on bacteria difficult to identify routinely, 296 strains were identified by molecular biology techniques as gold standard. MALDI-TOF-MS identification provided correct results at genus and species level for 94.9%, 83.4% and 83.8%, 65.9% with Biotyper and Saramis respectively.

  15. Improved Efficient, Nearly Orthogonal, Nearly Balanced Mixed Designs

    DTIC Science & Technology

    2011-12-01

    been widely used for computational experiments ( Sacks et al. 1989). They tend to have good space-filling and orthogonality behavior if n p, but when n...Fisher, R. A. 2000. Statistical methods for research workers. Edinburgh, Scotland: Oliver and Boyd. Hedayat, A. S., N. J. Sloane, and J. Stufken. 1999...methods. 2nd ed. Hoboken, New Jersey: Wiley. Sacks , J., W. J. Welch, T. J. Mitchell, and H. P. Wynn. 1989. Design and analysis of computer experiments

  16. Orthogonal Fabry-Pérot sensors for photoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Ellwood, R.; Ogunlade, O.; Zhang, E. Z.; Beard, P. C.; Cox, B. T.

    2016-03-01

    Fabry-Pérot (FP) sensors have been used to produce in-vivo photoacoustic images of exquisite quality. However, for simplicity of construction FP sensors are produced in a planar form. Planar sensors suffer from a limited detection aperture, due to their planarity. We present a novel sensor geometry that allowed a greater field of view by placing a second sensor orthogonal to the first. This captured data from the deeper lying regions of interest and mitigated the limited view.

  17. A general boundary capability embedded in an orthogonal mesh

    SciTech Connect

    Hewett, D.W.; Yu-Jiuan Chen

    1995-07-01

    The authors describe how they hold onto orthogonal mesh discretization when dealing with curved boundaries. Special difference operators were constructed to approximate numerical zones split by the domain boundary; the operators are particularly simple for this rectangular mesh. The authors demonstrated that this simple numerical approach, termed Dynamic Alternating Direction Implicit, turned out to be considerably more efficient than more complex grid-adaptive algorithms that were tried previously.

  18. Orthogonal mapping: A computer program for quantifying shape differences

    USGS Publications Warehouse

    Huffman, T.; Christopher, R.A.; Hazel, J.E.

    1978-01-01

    Quantitative differences in the shape of two or more objects can be obtained by Orthogonal Mapping provided coincidental or analogous points can be identified on each object. The least-squares difference between each set of analogous points is determined by use of a projective transformation of a set of measured points which involves the rotation, translocation, and scaling of these points relative to a set of fixed points. ?? 1978.

  19. Limited-memory adaptive snapshot selection for proper orthogonal decomposition

    SciTech Connect

    Oxberry, Geoffrey M.; Kostova-Vassilevska, Tanya; Arrighi, Bill; Chand, Kyle

    2015-04-02

    Reduced order models are useful for accelerating simulations in many-query contexts, such as optimization, uncertainty quantification, and sensitivity analysis. However, offline training of reduced order models can have prohibitively expensive memory and floating-point operation costs in high-performance computing applications, where memory per core is limited. To overcome this limitation for proper orthogonal decomposition, we propose a novel adaptive selection method for snapshots in time that limits offline training costs by selecting snapshots according an error control mechanism similar to that found in adaptive time-stepping ordinary differential equation solvers. The error estimator used in this work is related to theory bounding the approximation error in time of proper orthogonal decomposition-based reduced order models, and memory usage is minimized by computing the singular value decomposition using a single-pass incremental algorithm. Results for a viscous Burgers’ test problem demonstrate convergence in the limit as the algorithm error tolerances go to zero; in this limit, the full order model is recovered to within discretization error. The resulting method can be used on supercomputers to generate proper orthogonal decomposition-based reduced order models, or as a subroutine within hyperreduction algorithms that require taking snapshots in time, or within greedy algorithms for sampling parameter space.

  20. Parallel and orthogonal stimulus in ultradiluted neural networks

    NASA Astrophysics Data System (ADS)

    Sobral, G. A., Jr.; Vieira, V. M.; Lyra, M. L.; da Silva, C. R.

    2006-10-01

    Extending a model due to Derrida, Gardner, and Zippelius, we have studied the recognition ability of an extreme and asymmetrically diluted version of the Hopfield model for associative memory by including the effect of a stimulus in the dynamics of the system. We obtain exact results for the dynamic evolution of the average network superposition. The stimulus field was considered as proportional to the overlapping of the state of the system with a particular stimulated pattern. Two situations were analyzed, namely, the external stimulus acting on the initialization pattern (parallel stimulus) and the external stimulus acting on a pattern orthogonal to the initialization one (orthogonal stimulus). In both cases, we obtained the complete phase diagram in the parameter space composed of the stimulus field, thermal noise, and network capacity. Our results show that the system improves its recognition ability for parallel stimulus. For orthogonal stimulus two recognition phases emerge with the system locking at the initialization or stimulated pattern. We confront our analytical results with numerical simulations for the noiseless case T=0 .

  1. Parallel and orthogonal stimulus in ultradiluted neural networks.

    PubMed

    Sobral, G A; Vieira, V M; Lyra, M L; da Silva, C R

    2006-10-01

    Extending a model due to Derrida, Gardner, and Zippelius, we have studied the recognition ability of an extreme and asymmetrically diluted version of the Hopfield model for associative memory by including the effect of a stimulus in the dynamics of the system. We obtain exact results for the dynamic evolution of the average network superposition. The stimulus field was considered as proportional to the overlapping of the state of the system with a particular stimulated pattern. Two situations were analyzed, namely, the external stimulus acting on the initialization pattern (parallel stimulus) and the external stimulus acting on a pattern orthogonal to the initialization one (orthogonal stimulus). In both cases, we obtained the complete phase diagram in the parameter space composed of the stimulus field, thermal noise, and network capacity. Our results show that the system improves its recognition ability for parallel stimulus. For orthogonal stimulus two recognition phases emerge with the system locking at the initialization or stimulated pattern. We confront our analytical results with numerical simulations for the noiseless case T = 0.

  2. Orthogonal design for scale invariant feature transform optimization

    NASA Astrophysics Data System (ADS)

    Ding, Xintao; Luo, Yonglong; Yi, Yunyun; Jie, Biao; Wang, Taochun; Bian, Weixin

    2016-09-01

    To improve object recognition capabilities in applications, we used orthogonal design (OD) to choose a group of optimal parameters in the parameter space of scale invariant feature transform (SIFT). In the case of global optimization (GOP) and local optimization (LOP) objectives, our aim is to show the operation of OD on the SIFT method. The GOP aims to increase the number of correctly detected true matches (NoCDTM) and the ratio of NoCDTM to all matches. In contrast, the LOP mainly aims to increase the performance of recall-precision. In detail, we first abstracted the SIFT method to a 9-way fixed-effect model with an interaction. Second, we designed a mixed orthogonal array, MA(64,23420,2), and its header table to optimize the SIFT parameters. Finally, two groups of parameters were obtained for GOP and LOP after orthogonal experiments and statistical analyses were implemented. Our experiments on four groups of data demonstrate that compared with the state-of-the-art methods, GOP can access more correct matches and is more effective against object recognition. In addition, LOP is favorable in terms of the recall-precision.

  3. Modular and orthogonal synthesis of hybrid polymers and networks.

    PubMed

    Liu, Shuang; Dicker, Kevin T; Jia, Xinqiao

    2015-03-28

    Biomaterials scientists strive to develop polymeric materials with distinct chemical make-up, complex molecular architectures, robust mechanical properties and defined biological functions by drawing inspirations from biological systems. Salient features of biological designs include (1) repetitive presentation of basic motifs; and (2) efficient integration of diverse building blocks. Thus, an appealing approach to biomaterials synthesis is to combine synthetic and natural building blocks in a modular fashion employing novel chemical methods. Over the past decade, orthogonal chemistries have become powerful enabling tools for the modular synthesis of advanced biomaterials. These reactions require building blocks with complementary functionalities, occur under mild conditions in the presence of biological molecules and living cells and proceed with high yield and exceptional selectivity. These chemistries have facilitated the construction of complex polymers and networks in a step-growth fashion, allowing facile modulation of materials properties by simple variations of the building blocks. In this review, we first summarize features of several types of orthogonal chemistries. We then discuss recent progress in the synthesis of step growth linear polymers, dendrimers and networks that find application in drug delivery, 3D cell culture and tissue engineering. Overall, orthogonal reactions and modulular synthesis have not only minimized the steps needed for the desired chemical transformations but also maximized the diversity and functionality of the final products. The modular nature of the design, combined with the potential synergistic effect of the hybrid system, will likely result in novel hydrogel matrices with robust structures and defined functions.

  4. Minimal parameter solution of the orthogonal matrix differential equation

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, Itzhack Y.; Markley, F. Landis

    1990-01-01

    As demonstrated in this work, all orthogonal matrices solve a first order differential equation. The straightforward solution of this equation requires n sup 2 integrations to obtain the element of the nth order matrix. There are, however, only n(n-1)/2 independent parameters which determine an orthogonal matrix. The questions of choosing them, finding their differential equation and expressing the orthogonal matrix in terms of these parameters are considered. Several possibilities which are based on attitude determination in three dimensions are examined. It is shown that not all 3-D methods have useful extensions to higher dimensions. It is also shown why the rate of change of the matrix elements, which are the elements of the angular rate vector in 3-D, are the elements of a tensor of the second rank (dyadic) in spaces other than three dimensional. It is proven that the 3-D Gibbs vector (or Cayley Parameters) are extendable to other dimensions. An algorithm is developed emplying the resulting parameters, which are termed Extended Rodrigues Parameters, and numerical results are presented of the application of the algorithm to a fourth order matrix.

  5. The Sedimentation of Particles under Orthogonal Shear in Viscoelastic Fluids

    NASA Astrophysics Data System (ADS)

    Murch, William L.; Krishnan, Sreenath; Shaqfeh, Eric S. G.

    2016-11-01

    Many engineering applications, including oil and gas recovery, require the suspension of particles in viscoelastic fluids during fluid transport and processing. A topic of specific importance involves such particle suspensions experiencing an applied shear flow in a direction perpendicular to gravity (referred to as orthogonal shear). Previously, it has been shown that particle sedimentation coupled with an orthogonal shear flow can reduce the particle settling rate in elastic fluids. The underlying mechanism of this enhanced coupling drag is not fully understood, particularly at finite Weissenberg numbers. This talk examines the role of fluid elasticity on a single, non-Brownian, rigid sphere settling in orthogonal shear using experiments and numerical simulations. New experiments were performed in a Taylor-Couette flow cell using Boger fluids to study the coupling drag as a function of the shear and sedimentation Weissenberg numbers as well as particle confinement. The elastic effect was also studied with fully 3D simulations of flow past a rigid sphere, using the FENE-P constitutive model to describe the polymeric fluid rheology. These simulations show good agreement with the experiments and allow for further insight into the mechanism of elasticity-enhanced drag. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship.

  6. Minimal parameter solution of the orthogonal matrix differential equation

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, Itzhack Y.; Markley, F. Landis

    1988-01-01

    As demonstrated in this work, all orthogonal matrices solve a first order differential equation. The straightforward solution of this equation requires n sup 2 integrations to obtain the element of the nth order matrix. There are, however, only n(n-1)/2 independent parameters which determine an orthogonal matrix. The questions of choosing them, finding their differential equation and expressing the orthogonal matrix in terms of these parameters are considered. Several possibilities which are based on attitude determination in three dimensions are examined. It is shown that not all 3-D methods have useful extensions to higher dimensions. It is also shown why the rate of change of the matrix elements, which are the elements of the angular rate vector in 3-D, are the elements of a tensor of the second rank (dyadic) in spaces other than three dimensional. It is proven that the 3-D Gibbs vector (or Cayley Parameters) are extendable to other dimensions. An algorithm is developed employing the resulting parameters, which are termed Extended Rodrigues Parameters, and numerical results are presented of the application of the algorithm to a fourth order matrix.

  7. Multilayer block copolymer meshes by orthogonal self-assembly

    PubMed Central

    Tavakkoli K. G., Amir; Nicaise, Samuel M.; Gadelrab, Karim R.; Alexander-Katz, Alfredo; Ross, Caroline A.; Berggren, Karl K.

    2016-01-01

    Continued scaling-down of lithographic-pattern feature sizes has brought templated self-assembly of block copolymers (BCPs) into the forefront of nanofabrication research. Technologies now exist that facilitate significant control over otherwise unorganized assembly of BCP microdomains to form both long-range and locally complex monolayer patterns. In contrast, the extension of this control into multilayers or 3D structures of BCP microdomains remains limited, despite the possible technological applications in next-generation devices. Here, we develop and analyse an orthogonal self-assembly method in which multiple layers of distinct-molecular-weight BCPs naturally produce nanomesh structures of cylindrical microdomains without requiring layer-by-layer alignment or high-resolution lithographic templating. The mechanisms for orthogonal self-assembly are investigated with both experiment and simulation, and we determine that the control over height and chemical preference of templates are critical process parameters. The method is employed to produce nanomeshes with the shapes of circles and Y-intersections, and is extended to produce three layers of orthogonally oriented cylinders. PMID:26796218

  8. Modular and Orthogonal Synthesis of Hybrid Polymers and Networks

    PubMed Central

    Liu, Shuang; Dicker, Kevin T.; Jia, Xinqiao

    2015-01-01

    Biomaterials scientists strive to develop polymeric materials with distinct chemical make-up, complex molecular architectures, robust mechanical properties and defined biological functions by drawing inspirations from biological systems. Salient features of biological designs include (1) repetitive presentation of basic motifs; and (2) efficient integration of diverse building blocks. Thus, an appealing approach to biomaterials synthesis is to combine synthetic and natural building blocks in a modular fashion employing novel chemical methods. Over the past decade, orthogonal chemistries have become powerful enabling tools for the modular synthesis of advanced biomaterials. These reactions require building blocks with complementary functionalities, occur under mild conditions in the presence of biological molecules and living cells and proceed with high yield and exceptional selectivity. These chemistries have facilitated the construction of complex polymers and networks in a step-growth fashion, allowing facile modulation of materials properties by simple variations of the building blocks. In this review, we first summarize features of several types of orthogonal chemistries. We then discuss recent progress in the synthesis of step growth linear polymers, dendrimers and networks that find application in drug delivery, 3D cell culture and tissue engineering. Overall, orthogonal reactions and modulular synthesis have not only minimized the steps needed for the desired chemical transformations but also maximized the diversity and functionality of the final products. The modular nature of the design, combined with the potential synergistic effect of the hybrid system, will likely result in novel hydrogel matrices with robust structures and defined functions. PMID:25572255

  9. Rapid detection of AAC(6')-Ib-cr production using a MALDI-TOF MS strategy.

    PubMed

    Pardo, C-A; Tan, R N; Hennequin, C; Beyrouthy, R; Bonnet, R; Robin, F

    2016-12-01

    Plasmid-mediated quinolone resistance mechanisms have become increasingly prevalent among Enterobacteriaceae strains since the 1990s. Among these mechanisms, AAC(6')-Ib-cr is the most difficult to detect. Different detection methods have been developed, but they require expensive procedures such as Sanger sequencing, pyrosequencing, polymerase chain reaction (PCR) restriction, or the time-consuming phenotypic method of Wachino. In this study, we describe a simple matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) method which can be easily implemented in clinical laboratories that use the MALDI-TOF technique for bacterial identification. We tested 113 strains of Enterobacteriaceae, of which 64 harbored the aac(6')-Ib-cr gene. We compared two MALDI-TOF strategies, which differed by their norfloxacin concentration (0.03 vs. 0.5 g/L), and the method of Wachino with the PCR and sequencing strategy used as the reference. The MALDI-TOF strategy, performed with 0.03 g/L norfloxacin, and the method of Wachino yielded the same high performances (Se = 98 %, Sp = 100 %), but the turnaround time of the MALDI-TOF strategy was faster (<5 h), simpler, and inexpensive (<1 Euro). Our study shows that the MALDI-TOF strategy has the potential to become a major method for the detection of many different enzymatic resistance mechanisms.

  10. Progress in proteomics for clinical microbiology: MALDI-TOF MS for microbial species identification and more.

    PubMed

    van Belkum, Alex; Chatellier, Sonia; Girard, Victoria; Pincus, David; Deol, Parampal; Dunne, Wm Michael

    2015-01-01

    Although classical proteomic approaches are still used regularly in routine clinical diagnostic procedures, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) MS has recently moved into diagnostic microbiology laboratories. MALDI-TOF MS is currently replacing phenotypic microbial identification. Many laboratories now use MALDI-TOF MS for its high efficiency, both from a diagnostic and a cost-per-analysis point of view. The US FDA has now cleared two of the commercially available systems for in vitro diagnostics. This will further spark development of MS applications in antimicrobial susceptibility testing and epidemiology. This review summarizes the state of affairs of MALDI-TOF MS in clinical microbiology; however, this is an active field of research subject to rapid evolution. We emphasize assessment of the clinical relevance and studies focusing on data obtained through comparative analyses of different MALDI-TOF MS instrumentation and multicenter validation studies. The future of MALDI-TOF MS, including antimicrobial susceptibility testing and epidemiological typing, is also highlighted.

  11. MALDI TOF-TOF characterization of a light stabilizer polymer contaminant from polypropylene or polyethylene plastic test tubes.

    PubMed

    Sachon, Emmanuelle; Matheron, Lucrèce; Clodic, Gilles; Blasco, Thierry; Bolbach, Gérard

    2010-01-01

    Disposable plasticware such as plastic test tubes are routinely used in all proteomics laboratories. Additives in polymers are used to protect them against oxygen or ultraviolet (UV) light degradation. Hindered amine light stabilizers (HALSs) are of utmost importance in modern polyolefin (polypropylene, polyethylene) stabilization. In this article, we demonstrate that the manufacturing polymeric agent: poly-(N-beta-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidinyl succinate), known as Tinuvin-622 or Lowilite 62, from the HALS family, leaches from laboratory polypropylene or polyethylene plastic test tubes into the standard solvents for sample preparation. The analysis of these polluted samples by matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) mass spectrometry, in the positive mode, shows highly contaminated mass spectra, due to the high sensitivity of this technique. These contaminants have mass range and mass defect similar to those of peptides arising from the digestion of a protein in a conventional proteomics study. Therefore, they can be really harmful for proteomics studies, leading to misattributions, preventing any protein identification. In this article, an MS and MS/MS fingerprint of this pollutant is given and some pieces of advice to avoid it are proposed.

  12. Design and content determination of nimesulide injectable formulation.

    PubMed

    Luo, Lei; Tao, Wanfu; Bourkaib, Nadia; Luo, Yonghuang

    2015-07-01

    The aim of the present study was to formulate Nimesulide inject able solution, establish a method for content determination, and accumulate data for registration of a new Nimesulide formulation. The optimal Nimesulide inject able formulation was determined based on the results of single factor test and orthogonal test. Moreover, clarity, stability, pH, content and related substances of Nimesulide were used as the main study indicators. The content of Nimesulide in inject able solution was determined by the high performance liquid chromatography (HPLC) method. The mobile phase consisted of V (methanol): V (potassium dihydrogen phosphate, pH 4.2)=60:40 at a flow rate of 1.0 mL/min. The detection was carried out with UV detector (λ(max) =254 nm) under a column temperature of 25°C and an injection volume of 20μL. The optimal inject able formulation was 4% Nimesulide, 4% ethanolamine, 0.1% L-cysteine, 0.01% EDTA-2Na, a suitable amount of lactic acid and water for injection. Nimesulide detection limits range from 20 to 80 μg/mL with a correlation coefficient of 0.9995 and high average recovery 99.91% (RSD=0.06%). In conclusion, the formulation was suitable for Nimesulide inject able form, and the determination method was simple, sensitive and accurate. Therefore, the Nimesulide inject able formulation can be used for industrial production and effectively controlled.

  13. GC-TOF/MS-based metabolomic strategy for combined toxicity effects of deoxynivalenol and zearalenone on murine macrophage ANA-1 cells.

    PubMed

    Ji, Jian; Zhu, Pei; Pi, Fuwei; Sun, Chao; Jiang, Hui; Sun, Jiadi; Wang, Xiumei; Zhang, Yinzhi; Sun, Xiulan

    2016-09-15

    The actual health risk from exposure to combined mycotoxins is unknown, and few studies have focused on changes to cellular biological systems (e.g., metabolomics) caused by combined mycotoxic effects. To evaluate the combined mycotoxic effects of deoxynivalenol (DON) and zearalenone (ZEN) on the level of cellular biological systems, gas chromatographic, time-of-flight mass spectroscopy (GC-TOF/MS) of the complete murine macrophage ANA-1 cell metabolome was implemented in this study. Using optimized chromatography and mass spectrometry parameters, the metabolites detected by GC-TOF/MS were identified and processed using multivariate statistical analysis, including principal component analysis (PCA) and orthogonal projection on latent-structures discriminant analysis (OPLS-DA). The metabolite sets were screened for further pathway analysis under rules of t-test (P) value < 0.05, VIP value > 1, and similarity value > 500. The mainly interfered metabolism pathways were categorized into two dominant types: amino acid metabolism and glycometabolism. Four metabolites, palmitic acid, 1-monopalmitin, ribose-5-phosphate and 2-deoxy-D-galactose, occur only under combined "DON + ZEN" treatment, indicating abnormal metabolism in ANA-1 cells. The metabolic state of ANA-1 cells under induction by combined "DON + ZEN" illustrates that DON may inhibit the estrogenic effects of ZEN. Thus, the combined effect of "DON + ZEN" may exacerbate toxicity in the pentose phosphate pathway, while palmitic acid metabolism is likely a new pathway effected by the combination, "DON + ZEN."

  14. Iron Sucrose Injection

    MedlinePlus

    Iron sucrose injection is used treat iron-deficiency anemia (a lower than normal number of red blood cells due ... and may cause the kidneys to stop working). Iron sucrose injection is in a class of medications called iron ...

  15. Antigen injection (image)

    MedlinePlus

    Leprosy is caused by the organism Mycobacterium leprae . The leprosy test involves injection of an antigen just under ... if your body has a current or recent leprosy infection. The injection site is labeled and examined ...

  16. Corticotropin, Repository Injection

    MedlinePlus

    ... age; episodes of symptoms in people who have multiple sclerosis (MS; a disease in which the nerves do ... When corticotropin repository injection is used to treat multiple sclerosis, it is usually injected once a day for ...

  17. Sodium Ferric Gluconate Injection

    MedlinePlus

    Sodium ferric gluconate injection is used to treat iron-deficiency anemia (a lower than normal number of ... are also receiving the medication epoetin (Epogen, Procrit). Sodium ferric gluconate injection is in a class of ...

  18. Amphotericin B Liposomal Injection

    MedlinePlus

    Amphotericin B liposomal injection is used to treat fungal infections such as cryptococcal meningitis (a fungal infection of the ... infections in people who cannot receive conventional amphotericin B therapy. Amphotericin B liposomal injection is in a ...

  19. Calcitonin Salmon Injection

    MedlinePlus

    Calcitonin salmon injection is used to treat osteoporosis in postmenopausal women. Osteoporosis is a disease that causes bones to weaken and break more easily. Calcitonin salmon injection is also used to ...

  20. Urinary incontinence - injectable implant

    MedlinePlus

    Intrinsic sphincter deficiency repair; ISD repair; Injectable bulking agents for stress urinary incontinence ... Urine leakage that gets worse Pain where the injection was done Allergic reaction to the material Implant ...

  1. Slit injection device

    DOEpatents

    Alger, Terry W.; Schlitt, Leland G.; Bradley, Laird P.

    1976-06-15

    A laser cavity electron beam injection device provided with a single elongated slit window for passing a suitably shaped electron beam and means for varying the current density of the injected electron beam.

  2. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  3. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  4. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  5. Rich catalytic injection

    DOEpatents

    Veninger, Albert

    2008-12-30

    A gas turbine engine includes a compressor, a rich catalytic injector, a combustor, and a turbine. The rich catalytic injector includes a rich catalytic device, a mixing zone, and an injection assembly. The injection assembly provides an interface between the mixing zone and the combustor. The injection assembly can inject diffusion fuel into the combustor, provides flame aerodynamic stabilization in the combustor, and may include an ignition device.

  6. Flow injection mass spectral fingerprints demonstrate chemical differences in rio red grapefruit with respect to year, harvest time, and conventional versus organic farming

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spectral fingerprints were acquired for Ruby Red grapefruit using direct injection-electrospray ionization with time-of-flight and ion trap mass spectrometry (DI-ESI-TOF-MS and DI-ESI-IT-MS). Rio Red grapefruits were harvested 3 times a year (early, mid, and late harvests) in 2005 and 2006 from con...

  7. Fast SiPM Readout of the PANDA TOF Detector

    NASA Astrophysics Data System (ADS)

    Böhm, M.; Lehmann, A.; Motz, S.; Uhlig, F.

    2016-05-01

    For the identification of low momentum charged particles and for event timing purposes a barrel Time-of-Flight (TOF) detector surrounding the interaction point is planned for the PANDA experiment at FAIR . Since the boundary conditions in terms of available radial space and radiation length are quite strict the favored layout is a hodoscope composed of several thousand small scintillating tiles (SciTils) read out by silicon photomultipliers (SiPMs). A time resolution of well below 100 ps is aimed for. With the originally proposed 30 × 30 × 5 mm3 SciTils read out by two single 3 × 3 mm2 SiPMs at the rims of the scintillator the targeted time resolution can be just reached, but with a considerable position dependence across the scintillator surface. In this paper we discuss other design options to further improve the time resolution and its homogeneity. It will be shown that wide scintillating rods (SciRods) with a size of, e.g., 50 × 30 × 5 mm3 or longer and read out at opposite sides by a chain of four serially connected SiPMs a time resolution down to 50 ps can be reached without problems. In addition, the position dependence of the time resolution is negligible. These SciRods were tested in the laboratory with electrons of a 90Sr source and under real experimental conditions in a particle beam at CERN. The measured time resolutions using fast BC418 or BC420 plastic scintillators wrapped in aluminum foil were consistently between 45 and 75 ps dependent on the SciRod design. This is a significant improvement compared to the original SciTil layout.

  8. Beam injection into RHIC

    SciTech Connect

    Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

    1997-07-01

    During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

  9. MALDI-TOF Mass Spectrometry Discriminates Known Species and Marine Environmental Isolates of Pseudoalteromonas.

    PubMed

    Emami, Kaveh; Nelson, Andrew; Hack, Ethan; Zhang, Jinwei; Green, David H; Caldwell, Gary S; Mesbahi, Ehsan

    2016-01-01

    The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) biotyping has promise as a rapid and reliable method of identifying and distinguishing between different types of bacteria, but has had relatively limited application to marine bacteria and has not been applied systematically to Pseudoalteromonas. Therefore, we constructed a MALDI-TOF MS database of 31 known Pseudoalteromonas species, to which new isolates can be compared by MALDI-TOF biotyping. The ability of MALDI-TOF MS to distinguish between species was scrutinized by comparison with 16S rRNA gene sequencing. The patterns of similarity given by the two approaches were broadly but not completely consistent. In general, the resolution of MALDI-TOF MS was greater than that of 16S rRNA gene sequencing. The database was tested with 13 environmental Pseudoalteromonas isolates from UK waters. All of the test strains could be identified to genus level by MALDI-TOF MS biotyping, but most could not be definitely identified to species level. We conclude that several of these isolates, and possibly most, represent new species. Thus, further taxonomic investigation of Pseudoalteromonas is needed before MALDI-TOF MS biotyping can be used reliably for species identification. It is, however, a powerful tool for characterizing and distinguishing among environmental isolates and can make an important contribution to taxonomic studies.

  10. Utility of the MALDI-TOF MS method to identify nontuberculous mycobacteria.

    PubMed

    Kodana, Masahiro; Tarumoto, Norihito; Kawamura, Tohru; Saito, Taeko; Ohno, Hideaki; Maesaki, Shigefumi; Ikebuchi, Kenji

    2016-01-01

    In comparison to the conventional real-time polymerase chain reaction method (PCR method) or the DNA-DNA hybridization method (DDH method), the utility of NTM identification by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) method has seldom been reported. In this study, 75 clinical NTM isolates from our hospital between April 2013 and July 2014 were identified and analyzed using PCR, DDH, and MALDI-TOF MS methods, and the results for the MALDI-TOF MS method were compared with the others. Identification at the species level was in agreement for 71 (94.5%) of the 75 isolates. For further details, identification was possible for 23 (95.8%) of 24 Mycobacterium avium, 11 (100%) of 11 Mycobacterium intracellulare, and 1 (50%) of 2 isolates mixed with M. avium and M. intracellulare. Mycobacterium ksansasii, Mycobacterium abscessus, Mycobacterium fortuitum, Mycobacterium gordonae, and Mycobacterium chelonae identified by DDH method were same result by MALDI-TOF MS. Additionally, Mycobacterium mucogenicum, which could not be identified by the DDH method, was identified by the MALDI-TOF MS method. However, two isolates identified as Mycobacterium terrae by DDH method could not be identified by the MALDI-TOF MS method and were determined to be Mycobacterium arupense by 16S ribosomal RNA (rRNA) sequence analysis. The present findings show that, for rare bacterial species, identification is sometimes not possible, but, in most cases, the results of identification by the MALDI-TOF MS method have a high concordance rate with the results of the PCR and DDH methods.

  11. Strategies for safe injections.

    PubMed Central

    Battersby, A.; Feilden, R.; Stoeckel, P.; Da Silva, A.; Nelson, C.; Bass, A.

    1999-01-01

    In 1998, faced with growing international concern, WHO set out an approach for achieving injection safety that encompassed all elements from patients' expectations and doctors' prescribing habits to waste disposal. This article follows that lead and describes the implications of the approach for two injection technologies: sterilizable and disposable. It argues that focusing on any single technology diverts attention from the more fundamental need for health services to develop their own comprehensive strategies for safe injections. National health authorities will only be able to ensure that injections are administered safely if they take an approach that encompasses the whole system, and choose injection technologies that fit their circumstances. PMID:10680247

  12. Integrated, Dual Orthogonal Antennas for Polarimetric Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Pauli, Mario; Wiesbeck, Werner

    2015-04-01

    Ground penetrating radar systems are mostly equipped with single polarized antennas, for example with single linear polarization or with circular polarization. The radiated waves are partly reflected at the ground surface and very often the penetrating waves are distorted in their polarization. The distortion depends on the ground homogeneity and the orientation of the antennas relative to the ground structure. The received signals from the reflecting objects may most times only be classified according to their coverage and intensity. This makes the recognition of the objects difficult or impossible. In airborne and spaceborne Remote Sensing the systems are meanwhile mostly equipped with front ends with dual orthogonal polarized antennas for a full polarimetric operation. The received signals, registered in 2x2 scattering matrices according to co- and cross polarization, are processed for the evaluation of all features of the targets. Ground penetrating radars could also profit from the scientific results of Remote Sensing. The classification of detected objects for their structure and orientation requires more information in the reflected signal than can be measured with a single polarization [1, 2]. In this paper dual linear, orthogonal polarized antennas with a common single, frequency independent phase center, are presented [3]. The relative bandwidth of these antennas can be 1:3, up to 1:4. The antenna is designed to work in the frequency range between 3 GHz and 11 GHz, but can be easily adapted to the GPR frequency range by scaling. The size of the antenna scaled for operation in typical GPR frequencies would approximately be 20 by 20 cm2. By the implementation in a dielectric carrier it could be reduced in size if required. The major problem for ultra wide band, dual polarized antennas is the frequency independent feed network, realizing the required phase shifts. For these antennas a network, which is frequency independent over a wide range, has been

  13. Resolution enhancement of computed radiography images using two orthogonal tilts

    NASA Astrophysics Data System (ADS)

    Pollmann, Steven I.; Norley, Chris J. D.; Yuan, Xunhua; Holdsworth, David W.

    2012-03-01

    Limitations to the spatial resolution of current digital x-ray systems are bounded by the physical characteristics of the xray detector. However, the need to image smaller structures provides motivation to develop high-resolution x-ray detector systems for use with computed radiographic, and tomographic x-ray systems. We report the implementation of a tilted detector technique (TDT) to attain near isotropic resolution enhancement by combining two orthogonal image views, acquired with existing detector hardware tilted at a fixed angle. Images were acquired using a ceiling-mounted x-ray unit (Proteus XR/a, GE Medical Systems, 50kVp, 250mAs). Images were digitized using a Fujifilm Capsula X CR system, from a 35×43cm detector cassette placed on an angulated stand, featuring a 3520×4280 image matrix with an in-plane pixel spacing of 0.1mm. Three images were acquired: two for use with our TDT; and one for comparison, with no detector tilt. Performance was determined by using two line-pair phantoms (Models 07-521 and 07-533, Nuclear Associates) placed orthogonally to each other in the field of view. Custom software corrected for perspective distortion, co-registered and combined the tilted-detector images into a single higher-resolution image. Following unwarping and co-registration, the limiting spatial resolution of an image obtained via the weighted combination of the two orthogonal views (8 lp/mm) is found to be superior to that of a single view acquired with no detector tilt (5 lp/mm). This novel technique shows significant improvement in the spatial resolution of x-ray image acquisitions, using existing x-ray components and detector hardware.

  14. Adaptive PID control based on orthogonal endocrine neural networks.

    PubMed

    Milovanović, Miroslav B; Antić, Dragan S; Milojković, Marko T; Nikolić, Saša S; Perić, Staniša Lj; Spasić, Miodrag D

    2016-12-01

    A new intelligent hybrid structure used for online tuning of a PID controller is proposed in this paper. The structure is based on two adaptive neural networks, both with built-in Chebyshev orthogonal polynomials. First substructure network is a regular orthogonal neural network with implemented artificial endocrine factor (OENN), in the form of environmental stimuli, to its weights. It is used for approximation of control signals and for processing system deviation/disturbance signals which are introduced in the form of environmental stimuli. The output values of OENN are used to calculate artificial environmental stimuli (AES), which represent required adaptation measure of a second network-orthogonal endocrine adaptive neuro-fuzzy inference system (OEANFIS). OEANFIS is used to process control, output and error signals of a system and to generate adjustable values of proportional, derivative, and integral parameters, used for online tuning of a PID controller. The developed structure is experimentally tested on a laboratory model of the 3D crane system in terms of analysing tracking performances and deviation signals (error signals) of a payload. OENN-OEANFIS performances are compared with traditional PID and 6 intelligent PID type controllers. Tracking performance comparisons (in transient and steady-state period) showed that the proposed adaptive controller possesses performances within the range of other tested controllers. The main contribution of OENN-OEANFIS structure is significant minimization of deviation signals (17%-79%) compared to other controllers. It is recommended to exploit it when dealing with a highly nonlinear system which operates in the presence of undesirable disturbances.

  15. Generation, modulation and reception of orthogonally polarized signals

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.

    1985-01-01

    The radiating electromagnetic field of a dipole antenna is considered. By allowing the dipole to rotate about its midpoint, one can construct an entire set of signal polarizations wherein distinct members of the set are mutually orthogonal. It is shown how these signals can be modulated and demodulated to convey information. These ideas are then generalized, and both balanced, as well as unbalanced quadrapole modulations are defined. Methods of receiver synchronization to such signals are described, as well as their potential application to multiple access and anti-jam communications.

  16. Orthogonal Matching Pursuit under the Restricted Isometry Property

    DTIC Science & Technology

    2015-06-17

    ar X iv :1 50 6. 04 77 9v 1 [ m at h. N A ] 1 5 Ju n 20 15 Orthogonal Matching Pursuit under the Restricted Isometry Property ∗ Albert Cohen...applied to a dictionary D in a Hilbert space H. Given an element f ∈ H, OMP generates a sequence of approximations fn, n = 1, 2, . . ., each of which...is a linear combination of n dictionary elements chosen by a greedy criterion. It is studied whether the approximations fn are in some sense

  17. Dendron avidity platforms with orthogonal focal point coupling site

    NASA Astrophysics Data System (ADS)

    McNerny, Daniel Quinn

    This thesis explores the design and synthesis of bifunctional or modular platforms from poly(amidoamine) (PAMAM) dendrons. PAMAM dendrons with an orthogonal focal point are evaluated, testing several click chemistry reactions for high conversion and mild conditions. The orthogonal reaction chemistry used at the dendron focal point gives a precise 1:1 ratio of the attachment of multiple functionalities to a small molecular weight, chemically stable high avidity molecule. In the first component of the thesis, dendrons were synthesized with c(RGDyK) peptide on the surface to create a scaffold for cellular targeting and multivalent binding. Binary dendron-RGD conjugates were synthesized with a single imaging agent, therapeutic drug, or additional functionalized dendron at the focal point after a copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) click reaction. The targeted-dendron platform was shown to specifically target alphaVbeta3 integrin expressing human umbilical vein endothelial cells (HUVEC) and human glioblastoma cells (U87MG) in vitro via flow cytometry. Specific targeting of the dendron-RGD platform was further confirmed by confocal microscopy. Biological activity of the targeted drug conjugate was confirmed via XTT assay. The remainder of the thesis explores click chemistry reactions that do not require a metal catalyst, which may cause undesired toxicity for some biological applications. Thiol-based click chemistry, specifically the thiol-ene and thiol-yne reactions, is explored on dendron platforms. The thiol click reactions provide an improved efficiency, compared to CuAAC, by reaching quantitative conversion of the focal point in most cases. The thiol click reactions suffer from some setbacks: the need for a thermal or photoinitiator may prevent the conjugation of some functional ligands and the thiol chemistry is more prone to side reactions. Finally, strain-promoted alkyne-azide cycloadditions are examined. The ring-strain click chemistry

  18. Optimal approximation of harmonic growth clusters by orthogonal polynomials

    SciTech Connect

    Teodorescu, Razvan

    2008-01-01

    Interface dynamics in two-dimensional systems with a maximal number of conservation laws gives an accurate theoreticaI model for many physical processes, from the hydrodynamics of immiscible, viscous flows (zero surface-tension limit of Hele-Shaw flows), to the granular dynamics of hard spheres, and even diffusion-limited aggregation. Although a complete solution for the continuum case exists, efficient approximations of the boundary evolution are very useful due to their practical applications. In this article, the approximation scheme based on orthogonal polynomials with a deformed Gaussian kernel is discussed, as well as relations to potential theory.

  19. Variability in GRB light curves: Introducing Orthogonal Matching Pursuit

    NASA Astrophysics Data System (ADS)

    Dereli, Husne; Bégué, Damien; Ryde, Felix

    2016-07-01

    Constraining the variability of GRBs is important as it is one of the few keys to estimate many unknown parameters, such as the emission radius, the Lorentz factor, the size of the progenitor. In this work, we introduced the Orthogonal Matching Pursuit (OMP) method to study GRB light curves and to compute the minimum time variability of GRBs. Commonly used in medical sciences, this method reconstructs a signal by choosing among predefined functional shapes. We will discuss the implementation of the code, and compare its performances with those of other dedicated methods (Haar wavelet analysis, peak finding algorithm and step wise filter correlation).

  20. Conditioning Analysis of Incomplete Cholesky Factorizations with Orthogonal Dropping

    SciTech Connect

    Napov, Artem

    2013-08-01

    The analysis of preconditioners based on incomplete Cholesky factorization in which the neglected (dropped) components are orthogonal to the approximations being kept is presented. General estimate for the condition number of the preconditioned system is given which only depends on the accuracy of individual approximations. The estimate is further improved if, for instance, only the newly computed rows of the factor are modified during each approximation step. In this latter case it is further shown to be sharp. The analysis is illustrated with some existing factorizations in the context of discretized elliptic partial differential equations.

  1. Some properties of multiple orthogonal polynomials associated with Macdonald functions

    NASA Astrophysics Data System (ADS)

    Coussement, Els; van Assche, Walter

    2001-08-01

    Multiple orthogonal polynomials corresponding to two weights on [0,[infinity]) associated with modified Bessel functions (Macdonald functions) K[nu] and K[nu]+1 were introduced in Van Assche, Yakubovich (Integral Transforms Special Funct. 9 (2000) 229-244) and recently also studied by Ben Cheikh, Douak (Meth. Appl. Anal., to appear). We obtain explicit formulas for type I vector polynomials (An,n,Bn,n) and (An+1,n,Bn+1,n) and for type II polynomials Pn,n and Pn+1,n. We also obtain generating functions for types I and II polynomials.

  2. Transfer Function Identification Using Orthogonal Fourier Transform Modeling Functions

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2013-01-01

    A method for transfer function identification, including both model structure determination and parameter estimation, was developed and demonstrated. The approach uses orthogonal modeling functions generated from frequency domain data obtained by Fourier transformation of time series data. The method was applied to simulation data to identify continuous-time transfer function models and unsteady aerodynamic models. Model fit error, estimated model parameters, and the associated uncertainties were used to show the effectiveness of the method for identifying accurate transfer function models from noisy data.

  3. Magnetic particle detection in unshielded environment using orthogonal fluxgate gradiometer

    SciTech Connect

    Elrefai, Ahmed L. Sasada, Ichiro

    2015-05-07

    A new detection system for magnetic particles, which can operate in an unshielded environment, is developed using a fundamental mode orthogonal fluxgate gradiometer. The proposed detection system offers the advantages of cost, size, and weight reduction as compared to contamination detection systems using superconducting quantum interference device sensor. The detection system can be used to detect metallic contamination in foods or lithium ion battery production lines. The system has been investigated numerically to optimize various design parameters of the system. Experimental setup has been developed to evaluate some of the numerically predicted results. Steel balls were successfully detected down to the diameter of 50 μm.

  4. Capillary-Driven Flow in Liquid Filaments Connecting Orthogonal Channels

    NASA Technical Reports Server (NTRS)

    Allen, Jeffrey S.

    2005-01-01

    Capillary phenomena plays an important role in the management of product water in PEM fuel cells because of the length scales associated with the porous layers and the gas flow channels. The distribution of liquid water within the network of gas flow channels can be dramatically altered by capillary flow. We experimentally demonstrate the rapid movement of significant volumes of liquid via capillarity through thin liquid films which connect orthogonal channels. The microfluidic experiments discussed provide a good benchmark against which the proper modeling of capillarity by computational models may be tested. The effect of surface wettability, as expressed through the contact angle, on capillary flow will also be discussed.

  5. Magnetic particle detection in unshielded environment using orthogonal fluxgate gradiometer

    NASA Astrophysics Data System (ADS)

    Elrefai, Ahmed L.; Sasada, Ichiro

    2015-05-01

    A new detection system for magnetic particles, which can operate in an unshielded environment, is developed using a fundamental mode orthogonal fluxgate gradiometer. The proposed detection system offers the advantages of cost, size, and weight reduction as compared to contamination detection systems using superconducting quantum interference device sensor. The detection system can be used to detect metallic contamination in foods or lithium ion battery production lines. The system has been investigated numerically to optimize various design parameters of the system. Experimental setup has been developed to evaluate some of the numerically predicted results. Steel balls were successfully detected down to the diameter of 50 μm.

  6. Comprehensive Quantitative Analysis of SQ Injection Using Multiple Chromatographic Technologies.

    PubMed

    Chau, Siu-Leung; Huang, Zhi-Bing; Song, Yan-Gang; Yue, Rui-Qi; Ho, Alan; Lin, Chao-Zhan; Huang, Wen-Hua; Han, Quan-Bin

    2016-08-19

    Quality control of Chinese medicine injections remains a challenge due to our poor knowledge of their complex chemical profile. This study aims to investigate the chemical composition of one of the best-selling injections, Shenqi Fuzheng (SQ) injection (SQI), via a full component quantitative analysis. A total of 15 representative small molecular components of SQI were simultaneously determined using ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole tandem time-of-flight mass spectrometry (Q-TOF-MS); saccharide composition of SQI was also quantitatively determined by high performance liquid chromatography (HPLC) with evaporative light scattering detector (ELSD) on an amino column before and after acid hydrolysis. The existence of polysaccharides was also examined on a gel permeation chromatography column. The method was well validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to analyze 13 SQI samples. The results demonstrate that up to 94.69% (w/w) of this injection product are quantitatively determined, in which small molecules and monosaccharide/sucrose account for 0.18%-0.21%, and 53.49%-58.2%, respectively. The quantitative information contributes to accumulating scientific evidence to better understand the therapy efficacy and safety of complex Chinese medicine injections.

  7. [Identification of staphylococci directly from positive blood culture bottles by MALDI-TOF MS system].

    PubMed

    Kilic, Abdullah; Baysallar, Mehmet

    2014-07-01

    Bloodstream infections are substantial causes of morbidity and mortality worldwide. Staphylococcus species are the most commonly isolated microorganisms from blood cultures in clinical microbiology laboratories. MALDI-TOF MS (Matrix-Assisted Laser Desorption/Ionization Time- of- Flight Mass Spectrometry) system allows the identification of microorganisms directly from positive blood culture bottles. The aim of this study was to evaluate the MALDI-TOF MS system for the identification of staphylococci directly from the positive blood culture bottles which revealed the presence of gram-positive cocci by staining. A total of 96 positive blood culture bottles that yielded gram-positive cocci by Gram stain were evaluated. These blood cultures were obtained from 69 patients between December 2013-February 2014. Conventional methods and BD Phoenix™ automated bacterial identification system (Becton Dickinson, USA) were used for routine identification. The strains were also identified by real-time Taqman PCR (qPCR) which was considered as the reference method. In MALDI-TOF MS method, MALDI Sepsityper™ Kit was used for the bacterial identification and all measurements were carried out by using Microflex LT instrument and FlexControl 3.0 software (Bruker Daltonics, USA). Of 96 culture bottles positive for gram-positive cocci, 90 were correctly identified as staphylococci at genus level with all the three study methods (qPCR, BD Phoenix, Bruker MALDI-TOF MS). The other six samples were identified as Enterococcus faecium (n= 4) and Streptococcus pyogenes (n= 2) by both Phoenix and the MALDI-TOF systems. Of the 90 samples, 87 were identified at the species level (15 S.aureus, 33 S.epidermidis, 29 S.hominis, 10 S.haemolyticus) and three at the genus level by the reference qPCR method. When comparing the results obtained by qPCR and Bruker MALDI-TOF MS, incompatibility was detected for three isolates. Those isolates were identified as S.hominis by qPCR, however two of them were

  8. Developing integrated TOF-SIMS/MALDI IMS system in studying biological systems

    NASA Astrophysics Data System (ADS)

    Wu, Ligang

    Using imaging mass spectrometry (IMS) techniques (including TOF-SIMS and MALDI IMS) to study biological systems is a relatively new concept and quickly gained popularity in recent years. Imaging mass spectrometry is a discovery technology that utilizes a focused ion beam or laser beam to desorb ions from sample surface. By detecting the desorbed ions, the chemical distributions and biological changes of a sample surface can be analyzed. These techniques offer a new analytical imaging approach to investigate biological processes at the cellular and tissue level. In this research, a novel integrated TOF-SIMS/MALDI IMS system as well as IMS based biological-sample-preparation techniques and data-reduction methods are developed. We then demonstrate the power of these techniques in studying different biological systems, including monosaccharides isomers, human breast cancer cell lines, mouse embryo tissues and mouse kidney sections. Using TOF-SIMS and statistical analysis methods, seven monosaccharide isomers are fully differentiated by analyzing their characteristic spectral pattern. In addition, a deep understanding of the fragmentation pathway of these isomers under ion bombardment is gained. In an application of TOF-SIMS to the differentiation of three human breast cancer cell lines, MCF-7, T47D, and MDA-MB-231, we show that principal component analysis (PCA) data reduction of TOF-SIMS spectra can differentiate cellular compartments (cytosol, nuclear and particulate) within the cell types, as well as homogenates from among the three cell lines. In a tissue-specific application, we extend the analytical capabilities of TOF-SIMS and PCA by imaging and differentiating Formalin-fixed paraffin-embedded (FFPE) mouse embryo tissues. We demonstrate reproducible differentiation of six tissue types based on the remaining small molecules after paraffin-embedding and the fragments of the cellular proteins. In a unique study of fresh frozen mouse kidney tissues, both TOF

  9. Identification of bacteria isolated from veterinary clinical specimens using MALDI-TOF MS.

    PubMed

    Pavlovic, Melanie; Wudy, Corinna; Zeller-Peronnet, Veronique; Maggipinto, Marzena; Zimmermann, Pia; Straubinger, Alix; Iwobi, Azuka; Märtlbauer, Erwin; Busch, Ulrich; Huber, Ingrid

    2015-01-01

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has recently emerged as a rapid and accurate identification method for bacterial species. Although it has been successfully applied for the identification of human pathogens, it has so far not been well evaluated for routine identification of veterinary bacterial isolates. This study was performed to compare and evaluate the performance of MALDI-TOF MS based identification of veterinary bacterial isolates with commercially available conventional test systems. Discrepancies of both methods were resolved by sequencing 16S rDNA and, if necessary, the infB gene for Actinobacillus isolates. A total of 375 consecutively isolated veterinary samples were collected. Among the 357 isolates (95.2%) correctly identified at the genus level by MALDI-TOF MS, 338 of them (90.1% of the total isolates) were also correctly identified at the species level. Conventional methods offered correct species identification for 319 isolates (85.1%). MALDI-TOF identification therefore offered more accurate identification of veterinary bacterial isolates. An update of the in-house mass spectra database with additional reference spectra clearly improved the identification results. In conclusion, the presented data suggest that MALDI-TOF MS is an appropriate platform for classification and identification of veterinary bacterial isolates.

  10. Matrix assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS) in clinical microbiology.

    PubMed

    Angeletti, Silvia

    2016-09-06

    The microbiological management of patients with suspected bacterial infection includes the identification of the pathogen and the determination of the antibiotic susceptibility. These traditional approaches, based on the pure culture of the microorganism, require at least 36-48h. A new method, Matrix Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS), has been recently developed to profile bacterial proteins from whole cell extracts and obtain a bacterial fingerprint able to discriminate microorganisms from different genera and species. By whole cell-mass spectrometry, microbial identification can be achieved within minutes from cultured isolate, rather than traditional phenotypic or genotypic characterizations. From the year 2009 an explosion of applications of this technology has been observed with promising results. Several studies have been performed and showed that MALDI-TOF represents a reliable alternative method for rapid bacteria and fungi identification in clinical setting. A future area of expansion is represented by the application of MALDI-TOF technology to the antibiotic susceptibility test. In conclusion, the revision of the literature available up to date demonstrated that MALDI-TOF MS represents an innovative technology for the rapid and accurate identification of bacterial and fungal isolates in clinical settings. By an earlier microbiological diagnosis, MALDI-TOF MS contributes to a reduced mortality and hospitalization time of the patients and consequently has a significant impact on cost savings and public health.

  11. Identification of urinary tract pathogens after 3-hours urine culture by MALDI-TOF mass spectrometry.

    PubMed

    Haiko, Johanna; Savolainen, Laura E; Hilla, Risto; Pätäri-Sampo, Anu

    2016-10-01

    Complicated urinary tract infections, such as pyelonephritis, may lead to sepsis. Rapid diagnosis is needed to identify the causative urinary pathogen and to verify the appropriate empirical antimicrobial therapy. We describe here a rapid identification method for urinary pathogens: urine is incubated on chocolate agar for 3h at 35°C with 5% CO2 and subjected to MALDI-TOF MS analysis by VITEK MS. Overall 207 screened clinical urine samples were tested in parallel with conventional urine culture. The method, called U-si-MALDI-TOF (urine short incubation MALDI-TOF), showed correct identification for 86% of Gram-negative urinary tract pathogens (Escherichia coli, Klebsiella pneumoniae, and other Enterobacteriaceae), when present at >10(5)cfu/ml in culture (n=107), compared with conventional culture method. However, Gram-positive bacteria (n=28) were not successfully identified by U-si-MALDI-TOF. This method is especially suitable for rapid identification of E. coli, the most common cause of urinary tract infections and urosepsis. Turnaround time for identification using U-si-MALDI-TOF compared with conventional urine culture was improved from 24h to 4-6h.

  12. Depth Errors Analysis and Correction for Time-of-Flight (ToF) Cameras.

    PubMed

    He, Ying; Liang, Bin; Zou, Yu; He, Jin; Yang, Jun

    2017-01-05

    Time-of-Flight (ToF) cameras, a technology which has developed rapidly in recent years, are 3D imaging sensors providing a depth image as well as an amplitude image with a high frame rate. As a ToF camera is limited by the imaging conditions and external environment, its captured data are always subject to certain errors. This paper analyzes the influence of typical external distractions including material, color, distance, lighting, etc. on the depth error of ToF cameras. Our experiments indicated that factors such as lighting, color, material, and distance could cause different influences on the depth error of ToF cameras. However, since the forms of errors are uncertain, it's difficult to summarize them in a unified law. To further improve the measurement accuracy, this paper proposes an error correction method based on Particle Filter-Support Vector Machine (PF-SVM). Moreover, the experiment results showed that this method can effectively reduce the depth error of ToF cameras to 4.6 mm within its full measurement range (0.5-5 m).

  13. Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS.

    PubMed

    Cai, Lesi; Sheng, Linfeng; Xia, Mengchan; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong; Chen, Hongyuan

    2016-12-15

    Using matrix to enhance the molecular ion signals for biomolecule identification without loss of spatial resolution caused by matrix crystallization is a great challenge for the application of TOF-SIMS in real-world biological research. In this report, graphene oxide (GO) was used as a matrix for TOF-SIMS to improve the secondary ion yields of intact molecular ions ([M + H](+)). Identifying and distinguishing the molecular ions of lipids (m/z >700) therefore became straightforward. The spatial resolution of TOF-SIMS imaging could also be improved as GO can form a homogeneous layer of matrix instead of crystalline domain, which prevents high spatial resolution in TOF-SIMS imaging. Lipid mapping in presence of GO revealed the delicate morphology and distribution of single vesicles with a diameter of 800 nm. On GO matrix, the vesicles with similar shape but different chemical composition could be distinguished using molecular ions. This novel matrix holds potentials in such applications as the analysis and imaging of complex biological samples by TOF-SIMS. Graphical Abstract ᅟ.

  14. Evaluation of ice-tea quality by DART-TOF/MS.

    PubMed

    Rajchl, Aleš; Prchalová, Jana; Kružík, Vojtěch; Ševčík, Rudolf; Čížková, Helena

    2015-11-01

    DART (Direct Analysis in Real Time) coupled with Time-of-Flight Mass Spectrometry (TOF/MS) has been used for analyses of ice-teas. The article focuses on quality and authenticity of ice-teas as one of the most important tea-based products on the market. Twenty-one samples of ice-teas (black and green) were analysed. Selected compounds of ice-teas were determined: theobromine, caffeine, total phenolic compounds, total soluble solids, total amino acid concentration, preservatives and saccharides were determined. Fingerprints of DART-TOF/MS spectra were used for comprehensive assessment of the ice-tea samples. The DART-TOF/MS method was used for monitoring the following compounds: citric acid, caffeine, saccharides, artificial sweeteners (saccharin, acesulphame K), and preservatives (sorbic and benzoic acid), phosphoric acid and phenolic compounds. The measured data were subjected to a principal components analysis. The HPLC and DART-TOF/MS methods were compared in terms of determination of selected compounds (caffeine, benzoic acid, sorbic acid and saccharides) in the ice-teas. The DART-TOF/MS technique seems to be a suitable method for fast screening, testing quality and authenticity of tea-based products.

  15. Diversity of Clonostachys species assessed by molecular phylogenetics and MALDI-TOF mass spectrometry.

    PubMed

    Abreu, Lucas M; Moreira, Gláucia M; Ferreira, Douglas; Rodrigues-Filho, Edson; Pfenning, Ludwig H

    2014-12-01

    We assessed the species diversity among 45 strains of Clonostachys from different substrates and localities in Brazil using molecular phylogenetics, and compared the results with the phenotypic classification of strains obtained from matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analyses were based on beta tubulin (Tub), ITS-LSU rDNA, and a combined Tub-ITS DNA dataset. MALDI-TOF MS analyses were performed using intact conidia and conidiophores of strains cultivated on oatmeal agar and 4% malt extract agar. Six known species were identified: Clonostachys byssicola, Clonostachys candelabrum, Clonostachys pseudochroleuca, Clonostachys rhizophaga, Clonostachys rogersoniana, and Clonostachys rosea. Two clades and two singleton lineages did not correspond to known species represented in the reference DNA dataset and were identified as Clonostachys sp. 1-4. Multivariate cluster analyses of MALDI-TOF MS data classified the strains into eight clusters and three singletons, corresponding to the ten identified species plus one additional cluster containing two strains of C. rogersoniana that split from the other co-specific strains. The consistent results of MALDI-TOF MS supported the identification of strains assigned to C. byssicola and C. pseudochroleuca, which did not form well supported clades in all phylogenetic analyses, but formed distinct clusters in the MALDI-TOF dendrograms.

  16. [Utility of MALDI-TOF MS for the identification of anaerobic bacteria].

    PubMed

    Zárate, Mariela S; Romano, Vanesa; Nievas, Jimena; Smayevsky, Jorgelina

    2014-01-01

    The analysis by MALDI-TOF MS (Matrix-assited laser desorption/ionization time-of-flight mass spectrometry) has become a reference method for the identification of microorganisms in Clinical Microbiology. However, data on some groups of microorganisms are still controversial. The aim of this study is to determine the utility of MALDI-TOF MS for the identification of clinical isolates of anaerobic bacteria. One-hundred and six anaerobic bacteria isolates were analyzed by MALDI-TOF MS and by conventional biochemical tests. In those cases where identification by conventional methodology was not applicable or in the face of discordance between sequencing methodologies, 16 S rRNA gene sequence analysis was performed. The conventional method and MALDI-TOF MS agreed at genus and species level by 95.3 %. Concordance in gram-negative bacilli was 91.4% and 100% among gram-positive bacilli; there was also concordance both in the 8 isolates studied in gram-positive cocci and in the single gram-negative cocci included. The data obtained in this study demonstrate that MALDI-TOF MS offers the possibility of adequate identification of anaerobic bacteria.

  17. Depth Errors Analysis and Correction for Time-of-Flight (ToF) Cameras

    PubMed Central

    He, Ying; Liang, Bin; Zou, Yu; He, Jin; Yang, Jun

    2017-01-01

    Time-of-Flight (ToF) cameras, a technology which has developed rapidly in recent years, are 3D imaging sensors providing a depth image as well as an amplitude image with a high frame rate. As a ToF camera is limited by the imaging conditions and external environment, its captured data are always subject to certain errors. This paper analyzes the influence of typical external distractions including material, color, distance, lighting, etc. on the depth error of ToF cameras. Our experiments indicated that factors such as lighting, color, material, and distance could cause different influences on the depth error of ToF cameras. However, since the forms of errors are uncertain, it’s difficult to summarize them in a unified law. To further improve the measurement accuracy, this paper proposes an error correction method based on Particle Filter-Support Vector Machine (PF-SVM). Moreover, the experiment results showed that this method can effectively reduce the depth error of ToF cameras to 4.6 mm within its full measurement range (0.5–5 m). PMID:28067767

  18. Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS

    NASA Astrophysics Data System (ADS)

    Cai, Lesi; Sheng, Linfeng; Xia, Mengchan; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong; Chen, Hongyuan

    2016-12-01

    Using matrix to enhance the molecular ion signals for biomolecule identification without loss of spatial resolution caused by matrix crystallization is a great challenge for the application of TOF-SIMS in real-world biological research. In this report, graphene oxide (GO) was used as a matrix for TOF-SIMS to improve the secondary ion yields of intact molecular ions ([M + H]+). Identifying and distinguishing the molecular ions of lipids (m/z >700) therefore became straightforward. The spatial resolution of TOF-SIMS imaging could also be improved as GO can form a homogeneous layer of matrix instead of crystalline domain, which prevents high spatial resolution in TOF-SIMS imaging. Lipid mapping in presence of GO revealed the delicate morphology and distribution of single vesicles with a diameter of 800 nm. On GO matrix, the vesicles with similar shape but different chemical composition could be distinguished using molecular ions. This novel matrix holds potentials in such applications as the analysis and imaging of complex biological samples by TOF-SIMS.

  19. Investigation of natural dyes and ancient textiles from korea using TOF-SIMS

    NASA Astrophysics Data System (ADS)

    Lee, Yeonhee; Lee, Jihye; Kim, Youngsoo; Choi, Seokchan; Ham, Seung Wook; Kim, Kang-Jin

    2008-12-01

    The identification of the colorants used on ancient textiles provides a historical pathway to the understanding of the processes associated with one of the oldest of chemical technologies, namely textile dyeing. In this paper, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to detect dyes on textiles avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. The plant dyes investigated belong to a variety of chemical groups, which include curcumin, crocin, carthamin, purpurin, alizarin, brazilin, shikonin, and indigo. Reference textile samples were prepared with dye extracts of plants and were characterized by TOF-SIMS. TOF-SIMS spectra for the dyed textiles showed element ions from metallic mordants, specific fragment ions, and molecular ions from organic dyes. Remnant dyes on excavated textiles have also been identified using TOF-SIMS. The ancient textile sample showed the presence of indigo clearly, although the fiber itself had degraded badly. From the results, it was concluded that most of plant dyes can be identified with TOF-SIMS and it is a very promising technique for the archaeology field.

  20. Graphene Oxide as a Novel Evenly Continuous Phase Matrix for TOF-SIMS

    NASA Astrophysics Data System (ADS)

    Cai, Lesi; Sheng, Linfeng; Xia, Mengchan; Li, Zhanping; Zhang, Sichun; Zhang, Xinrong; Chen, Hongyuan

    2017-03-01

    Using matrix to enhance the molecular ion signals for biomolecule identification without loss of spatial resolution caused by matrix crystallization is a great challenge for the application of TOF-SIMS in real-world biological research. In this report, graphene oxide (GO) was used as a matrix for TOF-SIMS to improve the secondary ion yields of intact molecular ions ([M + H]+). Identifying and distinguishing the molecular ions of lipids ( m/z >700) therefore became straightforward. The spatial resolution of TOF-SIMS imaging could also be improved as GO can form a homogeneous layer of matrix instead of crystalline domain, which prevents high spatial resolution in TOF-SIMS imaging. Lipid mapping in presence of GO revealed the delicate morphology and distribution of single vesicles with a diameter of 800 nm. On GO matrix, the vesicles with similar shape but different chemical composition could be distinguished using molecular ions. This novel matrix holds potentials in such applications as the analysis and imaging of complex biological samples by TOF-SIMS.

  1. Flavonoids as matrices for MALDI-TOF mass spectrometric analysis of transition metal complexes

    NASA Astrophysics Data System (ADS)

    Petkovic, Marijana; Petrovic, Biljana; Savic, Jasmina; Bugarcic, Zivadin D.; Dimitric-Markovic, Jasmina; Momic, Tatjana; Vasic, Vesna

    2010-02-01

    Matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a suitable method for the analysis of inorganic and organic compounds and biomolecules. This makes MALDI-TOF MS convenient for monitoring the interaction of metallo-drugs with biomolecules. Results presented in this manuscript demonstrate that flavonoids such as apigenin, kaempferol and luteolin are suitable for MALDI-TOF MS analysis of Pt(II), Pd(II), Pt(IV) and Ru(III) complexes, giving different signal-to-noise ratios of the analyte peak. The MALDI-TOF mass spectra of inorganic complexes acquired with these flavonoid matrices are easy to interpret and have some advantages over the application of other commonly used matrices: a low number of matrix peaks are detectable and the coordinative metal-ligand bond is, in most cases, preserved. On the other hand, flavonoids do not act as typical matrices, as their excess is not required for the acquisition of MALDI-TOF mass spectra of inorganic complexes.

  2. Tof1p regulates DNA damage responses during S phase in Saccharomyces cerevisiae.

    PubMed Central

    Foss, E J

    2001-01-01

    A tof1 mutant was recovered in a screen aimed at identifying genes involved specifically in the S phase branch of the MEC1-dependent DNA damage response pathway. The screen was based on the observation that mutants missing this branch are particularly dependent on the cell cycle-wide branch and, therefore, on RAD9, for surviving DNA damage. tof1 and rad9 conferred synergistic sensitivity to MMS, UV, and HU, and the double mutant was incapable of slowing S phase in response to MMS, inducing RNR3 transcription in response to UV, and phosphorylating Rad53p in response to HU. TOF1's contribution to DNA damage response appeared to be restricted to S phase, since TOF1 did not contribute to UV-induced transcription during G1 or to the cdc13-1-induced block to anaphase in G2/M. I suggest a model in which Tof1p functions to link Mec1p with Rad53p. PMID:11156979

  3. Fuel injection apparatus

    SciTech Connect

    Omori, T.; Sakakibara, S.; Kato, M.; Masuda, A.

    1986-06-10

    A fuel injection apparatus is described for supplying fuel from a fuel tank to at least one combustion chamber of an internal combustion engine, comprising: an injector housing defining therein a pressure cylinder bore, an injection cylinder bore and a timing cylinder bore connected in series with the pressure cylinder bore; a pressure plunger, fitted in the pressure cylinder bore and having one end defining, in the pressure cylinder bore, a pressure pump chamber communicating with the injection cylinder bore and the timing cylinder bore; first fuel supply means for supplying fuel from the fuel tank to the pressure pump chamber; pressurizing means for reciprocating the pressure plunger in the pressure cylinder bore in synchronism with the engine operation so as to pressurize fuel in the pressure pump chamber; an injection plunger, having a diameter smaller than the pressure plunger, fitted in the injection cylinder bore and having two ends defining, in the injection cylinder bore, an injection pump chamber and a first communicating chamber communicating with the pressure pump chamber; second fuel supply means for adjusting the quantity of the fuel from the fuel tank in accordance with engine operation conditions so as to supply the adjusted fuel quantity to the injection pump chamber; injection valve means for injecting the fuel into the fuel pump chamber toward a combustion chamber of the engine when the pressure in the pressure pump chamber is applied to the injection plunger through the first communicating chamber, and the fuel pressure in the injection pump chamber reaches a predetermined injection pressure.

  4. Gas Chromatography Time-Of-Flight Mass Spectrometry (GC-TOF-MS)-Based Metabolomics for Comparison of Caffeinated and Decaffeinated Coffee and Its Implications for Alzheimer’s Disease

    PubMed Central

    Chang, Kai Lun; Ho, Paul C.

    2014-01-01

    Findings from epidemiology, preclinical and clinical studies indicate that consumption of coffee could have beneficial effects against dementia and Alzheimer’s disease (AD). The benefits appear to come from caffeinated coffee, but not decaffeinated coffee or pure caffeine itself. Therefore, the objective of this study was to use metabolomics approach to delineate the discriminant metabolites between caffeinated and decaffeinated coffee, which could have contributed to the observed therapeutic benefits. Gas chromatography time-of-flight mass spectrometry (GC-TOF-MS)-based metabolomics approach was employed to characterize the metabolic differences between caffeinated and decaffeinated coffee. Orthogonal partial least squares discriminant analysis (OPLS-DA) showed distinct separation between the two types of coffee (cumulative Q2 = 0.998). A total of 69 discriminant metabolites were identified based on the OPLS-DA model, with 37 and 32 metabolites detected to be higher in caffeinated and decaffeinated coffee, respectively. These metabolites include several benzoate and cinnamate-derived phenolic compounds, organic acids, sugar, fatty acids, and amino acids. Our study successfully established GC-TOF-MS based metabolomics approach as a highly robust tool in discriminant analysis between caffeinated and decaffeinated coffee samples. Discriminant metabolites identified in this study are biologically relevant and provide valuable insights into therapeutic research of coffee against AD. Our data also hint at possible involvement of gut microbial metabolism to enhance therapeutic potential of coffee components, which represents an interesting area for future research. PMID:25098597

  5. Langevin dynamics of a heavy particle and orthogonality effects

    NASA Astrophysics Data System (ADS)

    Thomas, Mark; Karzig, Torsten; Viola Kusminskiy, Silvia

    2015-12-01

    The dynamics of a classical heavy particle moving in a quantum environment is determined by a Langevin equation which encapsulates the effect of the environment-induced reaction forces on the particle. For an open quantum system, these include a Born-Oppenheimer force, a dissipative force, and a stochastic force due to shot and thermal noise. Recently, it was shown that these forces can be expressed in terms of the scattering matrix of the system by considering the classical heavy particle as a time-dependent scattering center, allowing to demonstrate interesting features of these forces when the system is driven out of equilibrium. At the same time, it is well known that small changes in a scattering potential can have a profound impact on a fermionic system due to the Anderson orthogonality catastrophe. In this work, by calculating the Loschmidt echo, we relate Anderson orthogonality effects with the mesoscopic reaction forces for an environment that can be taken out of equilibrium. In particular, we show how the decay of the Loschmidt echo is characterized by fluctuations and dissipation in the system and discuss different quench protocols.

  6. Texel-based image classification with orthogonal bases

    NASA Astrophysics Data System (ADS)

    Carbajal-Degante, Erik; Nava, Rodrigo; Olveres, Jimena; Escalante-Ramírez, Boris; Kybic, Jan

    2016-04-01

    Periodic variations in patterns within a group of pixels provide important information about the surface of interest and can be used to identify objects or regions. Hence, a proper analysis can be applied to extract particular features according to some specific image properties. Recently, texture analysis using orthogonal polynomials has gained attention since polynomials characterize the pseudo-periodic behavior of textures through the projection of the pattern of interest over a group of kernel functions. However, the maximum polynomial order is often linked to the size of the texture, which implies in many cases, a complex calculation and introduces instability in higher orders leading to computational errors. In this paper, we address this issue and explore a pre-processing stage to compute the optimal size of the window of analysis called "texel." We propose Haralick-based metrics to find the main oscillation period, such that, it represents the fundamental texture and captures the minimum information, which is sufficient for classification tasks. This procedure avoids the computation of large polynomials and reduces substantially the feature space with small classification errors. Our proposal is also compared against different fixed-size windows. We also show similarities between full-image representations and the ones based on texels in terms of visual structures and feature vectors using two different orthogonal bases: Tchebichef and Hermite polynomials. Finally, we assess the performance of the proposal using well-known texture databases found in the literature.

  7. Orthogonalizing EM: A design-based least squares algorithm.

    PubMed

    Xiong, Shifeng; Dai, Bin; Huling, Jared; Qian, Peter Z G

    We introduce an efficient iterative algorithm, intended for various least squares problems, based on a design of experiments perspective. The algorithm, called orthogonalizing EM (OEM), works for ordinary least squares and can be easily extended to penalized least squares. The main idea of the procedure is to orthogonalize a design matrix by adding new rows and then solve the original problem by embedding the augmented design in a missing data framework. We establish several attractive theoretical properties concerning OEM. For the ordinary least squares with a singular regression matrix, an OEM sequence converges to the Moore-Penrose generalized inverse-based least squares estimator. For ordinary and penalized least squares with various penalties, it converges to a point having grouping coherence for fully aliased regression matrices. Convergence and the convergence rate of the algorithm are examined. Finally, we demonstrate that OEM is highly efficient for large-scale least squares and penalized least squares problems, and is considerably faster than competing methods when n is much larger than p. Supplementary materials for this article are available online.

  8. Orthogonalizing EM: A design-based least squares algorithm

    PubMed Central

    Xiong, Shifeng; Dai, Bin; Huling, Jared; Qian, Peter Z. G.

    2016-01-01

    We introduce an efficient iterative algorithm, intended for various least squares problems, based on a design of experiments perspective. The algorithm, called orthogonalizing EM (OEM), works for ordinary least squares and can be easily extended to penalized least squares. The main idea of the procedure is to orthogonalize a design matrix by adding new rows and then solve the original problem by embedding the augmented design in a missing data framework. We establish several attractive theoretical properties concerning OEM. For the ordinary least squares with a singular regression matrix, an OEM sequence converges to the Moore-Penrose generalized inverse-based least squares estimator. For ordinary and penalized least squares with various penalties, it converges to a point having grouping coherence for fully aliased regression matrices. Convergence and the convergence rate of the algorithm are examined. Finally, we demonstrate that OEM is highly efficient for large-scale least squares and penalized least squares problems, and is considerably faster than competing methods when n is much larger than p. Supplementary materials for this article are available online. PMID:27499558

  9. Supervised orthogonal discriminant subspace projects learning for face recognition.

    PubMed

    Chen, Yu; Xu, Xiao-Hong

    2014-02-01

    In this paper, a new linear dimension reduction method called supervised orthogonal discriminant subspace projection (SODSP) is proposed, which addresses high-dimensionality of data and the small sample size problem. More specifically, given a set of data points in the ambient space, a novel weight matrix that describes the relationship between the data points is first built. And in order to model the manifold structure, the class information is incorporated into the weight matrix. Based on the novel weight matrix, the local scatter matrix as well as non-local scatter matrix is defined such that the neighborhood structure can be preserved. In order to enhance the recognition ability, we impose an orthogonal constraint into a graph-based maximum margin analysis, seeking to find a projection that maximizes the difference, rather than the ratio between the non-local scatter and the local scatter. In this way, SODSP naturally avoids the singularity problem. Further, we develop an efficient and stable algorithm for implementing SODSP, especially, on high-dimensional data set. Moreover, the theoretical analysis shows that LPP is a special instance of SODSP by imposing some constraints. Experiments on the ORL, Yale, Extended Yale face database B and FERET face database are performed to test and evaluate the proposed algorithm. The results demonstrate the effectiveness of SODSP.

  10. Impact Damage of 3D Orthogonal Woven Composite Circular Plates

    NASA Astrophysics Data System (ADS)

    Ji, Changgan; Sun, Baozhong; Qiu, Yiping; Gu, Bohong

    2007-11-01

    The damages of 3D orthogonal woven composite circular plate under quasi-static indentation and transverse impact were tested with Materials Test System (MTS) and modified split Hopkinson bar (SHPB) apparatus. The load vs. displacement curves during quasi-static penetration and impact were obtained to study the energy absorption of the composite plate. The fluctuation of the impact stress waves has been unveiled. Differences of the load-displacement curves between the quasi-static and impact loading are discussed. This work also aims at establishing a unit-cell model to analyze the damage of composites. A user material subroutine which named VUMAT for characterizing the constitutive relationship of the 3-D orthogonal woven composite and the damage evolution is incorporated with a finite element code ABAQUS/Explicit to simulate the impact damage process of the composite plates. From the comparison of the load-displacement curves and energy absorption curves of the composite plate between experimental and FEM simulation, it is shown that the unit-cell model of the 3D woven composite and the VUMAT combined with the ABAQUS/Explicit can calculate the impact responses of the circular plate precisely. Furthermore, the model can also be extended to simulate the impact behavior of the 3D woven composite structures.

  11. Geometric Attitude Controls And Estimations On The Special Orthogonal Group

    NASA Astrophysics Data System (ADS)

    Wu, Tse-Huai

    This dissertation is concerned with spacecraft attitude control and estimation problems from the point of view of geometric mechanics. The controllers and observers are built on the special orthogonal group without any parameterizations, where the attitude dynamics is treated in a global and unique manner. The dissertation is composed of three parts. A leader-follower attitude formation control scheme is reported such that the leader spacecraft control its absolute attitude with respect to the inertial reference frame and the follower spacecraft control relative attitude with respect to other spacecraft in the formation. The unique feature is that both the absolute attitude and the relative attitude control systems are developed directly in terms of the line-of-sight observations, where attitude determination and estimation processes are not required. Second, an angular velocity observer is developed such that the estimated angular velocity is guaranteed to converge to the true angular velocity asymptotically from almost all initial estimates. Then, the presented observer is integrated with a proportional-derivative attitude tracking controller to show a separation type property for attitude tracking in the absence of angular velocity measurements. A hybrid observer for the attitude dynamics of a rigid body is proposed to guarantee global asymptotic stability. By designing a set of attitude error functions, attitude estimates are expelled from undesired equilibria to achieve global asymptotic stability. To guarantee that the estimated attitudes evolve on the special orthogonal group, a numerical algorithm based on the Lie group method is presented.

  12. Statistical benchmarking for orthogonal electrostatic quantum dot qubit devices

    NASA Astrophysics Data System (ADS)

    Gamble, John; Frees, Adam; Friesen, Mark; Coppersmith, S. N.

    2014-03-01

    Quantum dots in semiconductor systems have emerged as attractive candidates for the implementation of quantum information processors because of the promise of scalability, manipulability, and integration with existing classical electronics. A limitation in current devices is that the electrostatic gates used for qubit manipulation exhibit strong cross-capacitance, presenting a barrier for practical scale-up. Here, we introduce a statistical framework for making precise the notion of orthogonality. We apply our method to analyze recently implemented designs at the University of Wisconsin-Madison that exhibit much increased orthogonal control than was previously possible. We then use our statistical modeling to future device designs, providing practical guidelines for devices to have robust control properties. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy Nuclear Security Administration under contract DE-AC04-94AL85000. The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the US Government. This work was supported in part by the Laboratory Directed Research and Development program at Sandia National Laboratories, by ARO (W911NF-12-0607), and by the United States Department of Defense.

  13. Cerenkov luminescence tomography based on preconditioning orthogonal matching pursuit

    NASA Astrophysics Data System (ADS)

    Liu, Haixiao; Hu, Zhenhua; Wang, Kun; Tian, Jie; Yang, Xin

    2015-03-01

    Cerenkov luminescence imaging (CLI) is a novel optical imaging method and has been proved to be a potential substitute of the traditional radionuclide imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This imaging method inherits the high sensitivity of nuclear medicine and low cost of optical molecular imaging. To obtain the depth information of the radioactive isotope, Cerenkov luminescence tomography (CLT) is established and the 3D distribution of the isotope is reconstructed. However, because of the strong absorption and scatter, the reconstruction of the CLT sources is always converted to an ill-posed linear system which is hard to be solved. In this work, the sparse nature of the light source was taken into account and the preconditioning orthogonal matching pursuit (POMP) method was established to effectively reduce the ill-posedness and obtain better reconstruction accuracy. To prove the accuracy and speed of this algorithm, a heterogeneous numerical phantom experiment and an in vivo mouse experiment were conducted. Both the simulation result and the mouse experiment showed that our reconstruction method can provide more accurate reconstruction result compared with the traditional Tikhonov regularization method and the ordinary orthogonal matching pursuit (OMP) method. Our reconstruction method will provide technical support for the biological application for Cerenkov luminescence.

  14. Epidural injections for back pain

    MedlinePlus

    ESI; Spinal injection for back pain; Back pain injection; Steroid injection - epidural; Steroid injection - back ... pillow under your stomach. If this position causes pain, you either sit up or lie on your ...

  15. Methods and compositions for the production of orthogonal tRNA-aminoacyl tRNA synthetase pairs

    DOEpatents

    Schultz, Peter G.; Wang, Lei; Anderson, John Christopher; Chin, Jason W.; Liu, David R.; Magliery, Thomas J.; Meggers, Eric L.; Mehl, Ryan Aaron; Pastrnak, Miro; Santoro, Stephen William; Zhang, Zhiwen

    2015-10-20

    This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.

  16. Methods and compositions for the production of orthogonal tRNA-aminoacyl tRNA synthetase pairs

    SciTech Connect

    Schultz, Peter; Wang, Lei; Anderson, John Christopher; Chin, Jason; Liu, David R.; Magliery, Thomas J.; Meggers, Eric L.; Mehl, Ryan Aaron; Pastrnak, Miro; Santoro, Stephen William; Zhang, Zhiwen

    2006-08-01

    This invention provides compositions and methods for generating components of protein biosynthetic machinery including orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases. Methods for identifying orthogonal pairs are also provided. These components can be used to incorporate unnatural amino acids into proteins in vivo.

  17. Injection-water quality

    SciTech Connect

    Patton, C.C. )

    1990-10-01

    Ideally, injection water should enter the reservoir free of suspended solids or oil. It should also be compatible with the reservoir rock and fluids and would be sterile and nonscaling. This paper discusses how the objective of any water-injection operation is to inject water into the reservoir rock without plugging or permeability reduction from particulates, dispersed oil, scale formation, bacterial growth, or clay swelling. In addition, souring of sweet reservoirs by sulfate-reducing bacteria should be prevented if possible.

  18. [Stability of liensinine injection].

    PubMed

    Hu, X M; Zhou, B H; Luo, S D

    1993-06-01

    The stability of liensinine injection was studied by accelarating test with classical isothermal method. Results of the study showed that the decomposition of the injection was found to be a first-order reaction. The activation energy was 75030 J.mol-1. The shelf life at 10 degrees C and 25 degrees C was predicted to be about 15 months and 3 months respectively. This experiment provides a reference for the storage of the injection.

  19. MALDI-TOF MS in clinical parasitology: applications, constraints and prospects.

    PubMed

    Singhal, Neelja; Kumar, Manish; Virdi, Jugsharan Singh

    2016-10-01

    Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) is currently being used for rapid and reproducible identification of bacteria, viruses and fungi in clinical microbiological laboratories. However, some studies have also reported the use of MALDI-TOF MS for identification of parasites, like Leishmania, Giardia, Cryptosporidium, Entamoeba, ticks and fleas. The present review collates all the information available on the use of this technique for parasites, in an effort to assess its applicability and the constraints for identification/diagnosis of parasites and diseases caused by them. Though MALDI-TOF MS-based identification of parasites is currently done by reference laboratories only, in future, this promising technology might surely replace/augment molecular methods in clinical parasitology laboratories.

  20. A solution for the inner area of CBM-TOF with pad-MRPC

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Huang, X. J.; Lyu, P. F.; Han, D.; Xie, B.; Li, Y. J.; Herrmann, N.; Deppner, I.; Loizeau, P.; Simon, C.; Frühauf, J.; Kiš, M.

    2017-02-01

    The Compressed Baryonic Matter (CBM) experiment has decided to use the Multi-gap Resistive Plate Chambers(MRPC) technology to build its Time-Of-Flight (TOF) wall. CBM-TOF requires a rate capability over 20 kHz/cm2 for inner region. A 10-gap pad-MRPC assembled with low resistive glass is designed to construct this area. The prototypes, which consist of 10×0.22 mm gas gaps and 2×8 20 mm×20 mm readout pads, require fewer electronic channels compared to the strip design. A timing resolution of around 60 ps and an efficiency above 98% were obtained in a cosmic test and a beam test taken in 2014 October GSI beam time. The results show that the real-size prototypes fulfill the requirements of the CBM-TOF.

  1. Geant4 simulations of the neutron production and transport in the n_TOF spallation target

    NASA Astrophysics Data System (ADS)

    Lerendegui-Marco, J.; Cortés-Giraldo, M. A.; Guerrero, C.; Quesada, J. M.

    2016-11-01

    The neutron production and transport in the spallation target of the n_TOF facility at CERN has been simulated with Geant4. The results obtained with the different hadronic Physics Lists provided by Geant4 have been compared with the experimental neutron flux in n_TOF-EAR1. The best overall agreement in both the absolute value and the energy dependence of the flux from thermal to 1GeV, is obtained with the INCL++ model coupled with the Fritiof Model(FTFP). This Physics List has been thus used to simulate and study the main features of the new n_TOF-EAR2 beam line, currently in its commissioning phase.

  2. [A new neuromuscular transmission monitor (TOF Guard): the rationale behind the method and its clinical usefulness].

    PubMed

    Ueda, N; Masuda, Y; Muteki, T; Tsuda, H; Hiraki, T; Harada, H; Tobata, H

    1994-01-01

    TOF Guard is one of the latest developments in the field of neuromuscular monitoring equipment. This system uses a miniature acceleration transducer (a piezo-electric ceramic wafer is used), simply fastened to the thumb with tape. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. In this study, authors assessed the accuracy of this system in clinical use, comparing with the force transducer method (Myograph 2000). The result showed that there was a very close positive correlation between the values of T1, TOF ratio and posttetanic count simultaneously measured by both methods. The coefficient of correlation was 0.96, and its significance level was P < 0.001. From the clinical view point, it is concluded that TOF Guard is very useful because of its accuracy and because the equipment is easy to handle, compact and of low price as a neuromuscular monitoring system for routine anesthesia.

  3. TOF-Bρ mass measurements of very exotic nuclides for astrophysical calculations at the NSCL

    NASA Astrophysics Data System (ADS)

    Matoš, M.; Estrade, A.; Amthor, M.; Aprahamian, A.; Bazin, D.; Becerril, A.; Elliot, T.; Galaviz, D.; Gade, A.; Gupta, S.; Lorusso, G.; Montes, F.; Pereira, J.; Portillo, M.; Rogers, A. M.; Schatz, H.; Shapira, D.; Smith, E.; Stolz, A.; Wallace, M.

    2008-01-01

    Atomic masses play a crucial role in many nuclear astrophysics calculations. The lack of experimental values for relevant exotic nuclides triggered a rapid development of new mass measurement devices around the world. The time-of-flight (TOF) mass measurements offer a complementary technique to the most precise one, Penning trap measurements (Blaum 2006 Phys. Rep. 425 1), the latter being limited by the rate and half-lives of the ions of interest. The NSCL facility provides a well-suited infrastructure for the TOF mass measurements of very exotic nuclei. At this facility, we have recently implemented a TOF-Bρ technique and performed mass measurements of neutron-rich nuclides in the Fe region, important for r-process calculations and for calculations of processes occurring in the crust of accreting neutron stars.

  4. [Evaluation of mass spectrometry: MALDI-TOF MS for fast and reliable yeast identification].

    PubMed

    Relloso, María S; Nievas, Jimena; Fares Taie, Santiago; Farquharson, Victoria; Mujica, María T; Romano, Vanesa; Zarate, Mariela S; Smayevsky, Jorgelina

    2015-01-01

    The matrix-assisted laser desorption/ionization time-of-flight mass spectrometry technique known as MALDI-TOF MS is a tool used for the identification of clinical pathogens by generating a protein spectrum that is unique for a given species. In this study we assessed the identification of clinical yeast isolates by MALDI-TOF MS in a university hospital from Argentina and compared two procedures for protein extraction: a rapid method and a procedure based on the manufacturer's recommendations. A short protein extraction procedure was applied in 100 isolates and the rate of correct identification at genus and species level was 98.0%. In addition, we analyzed 201 isolates, previously identified by conventional methods, using the methodology recommended by the manufacturer and there was 95.38% coincidence in the identification at species level. MALDI TOF MS showed to be a fast, simple and reliable tool for yeast identification.

  5. MALDI-TOF MS: an upcoming tool for rapid detection of antibiotic resistance in microorganisms.

    PubMed

    Kostrzewa, Markus; Sparbier, Katrin; Maier, Thomas; Schubert, Sören

    2013-12-01

    MALDI-TOF MS profiling for microorganism detection has already been demonstrated in the 1990s, but has evolved to the first-line identification method in many laboratories just during the past five years. While this application of MALDI-TOF MS has proven its broad applicability, accuracy, robustness, and cost-effectiveness it is of particular interest to expand the capabilities of the mass spectrometric platform. Resistance detection is the most desirable further application of MALDI-TOF MS in microbiology, but maybe also the most challenging. Different approaches have been published regarding diverse antibiotic drugs and distinct microorganism classes. The current review shall give an overview about the developments of the recent years and their potential to get transformed in clinical useful assays in the future.

  6. Automated Gain Control Ion Funnel Trap for Orthogonal Time-of-Flight Mass Spectrometry

    PubMed Central

    Ibrahim, Yehia M.; Belov, Mikhail E.; Liyu, Andrei V.; Smith, Richard D.

    2009-01-01

    Time-of-flight mass spectrometry (TOF MS) is increasingly used in proteomics research. Herein, we report on the development and characterization of a TOF MS instrument with improved sensitivity equipped with an electrodynamic ion funnel trap (IFT) that employs an automated gain control (AGC) capability. The IFT-TOF MS was coupled to a reversed-phase capillary liquid chromatography (RPLC) separation and evaluated in experiments with complex proteolytic digests. When applied to a global tryptic digest of Shewanella oneidensis proteins, an order-of-magnitude increase in sensitivity compared to that of the conventional continuous mode of operation was achieved due to efficient ion accumulation prior to TOF MS analysis. As a result of this sensitivity improvement and related improvement in mass measurement accuracy, the number of unique peptides identified in the AGC-IFT mode was 5-fold greater than that obtained in the continuous mode. PMID:18512944

  7. Botulinum toxin injection - larynx

    MedlinePlus

    Injection laryngoplasty; Botox-larynx: spasmodic dysphonia-BTX; Essential voice tremor (EVT)-btx; Glottic insufficiency; Percutaneous electromyography-guided botulinum toxin treatment; Percutaneous indirect laryngoscopy- ...

  8. Underground Injection Control (UIC)

    EPA Pesticide Factsheets

    Provide information on: individual injection well classes; regulations specific to each well class; technical guidance; compliance assistance; federal, state, and tribal/territory roles and responsibilities.

  9. Piezoelectric Injection Systems

    NASA Astrophysics Data System (ADS)

    Mock, R.; Lubitz, K.

    The origin of direct injection can be doubtlessly attributed to Rudolf Diesel who used air assisted injection for fuel atomisation in his first self-ignition engine. Although it became apparent already at that time that direct injection leads to reduced specific fuel consumption compared to other methods of fuel injection, it was not used in passenger cars for the moment because of its disadvantageous noise generation as the requirements with regard to comfort were seen as more important than a reduced specific consumption.

  10. Comparison of MALDI-TOF mass spectra with microsatellite length polymorphisms in Candida albicans.

    PubMed

    Dhieb, C; Normand, A C; L'Ollivier, C; Gautier, M; Vranckx, K; El Euch, D; Chaker, E; Hendrickx, M; Dalle, F; Sadfi, N; Piarroux, R; Ranque, S

    2015-02-01

    Candida albicans is the most frequent yeast involved in human infections. Its population structure can be divided into several genetic clades, some of which have been associated with antifungal susceptibility. Therefore, detecting and monitoring fungal clones in a routine laboratory setting would be a major epidemiological advance. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra results are now widely used as bar codes to identify microorganisms in clinical microbiology laboratories. This study aimed at testing MALDI-TOF mass spectra bar codes to identify clades among a set of C. albicans isolates. Accordingly, 102 clinical strains were genotyped using 10 microsatellite markers and analyzed via MALDI-TOF mass spectrometry. The mass spectra were compared with a reference spectral library including 33 well-characterized collection strains, using a Microflex(TM) system and Biotyper(TM) software, to test the capacity of the spectrum of a given isolate to match with the reference mass spectrum of an isolate from the same genetic clade. Despite high confidence species identification, the spectra failed to significantly match with the corresponding clade (p = 0.74). This was confirmed with the MALDI-TOF spectra similarity dendrogram, in which the strains were dispersed irrespective of their genetic clade. Various attempts to improve intra-clade spectra recognition were unsuccessful. In conclusion, MALDI-TOF mass spectra bar code analysis failed to reliably recognize genetically related C. albicans isolates. Further studies are warranted to develop alternative MALDI-TOF mass spectra analytical approaches to identify and monitor C. albicans clades in the routine clinical laboratory.

  11. Shiga toxin 2 subtypes of enterohemorrhagic E. coli O157:H- E32511 analyzed by RT-qPCR and top-down proteomics using MALDI-TOF-TOF-MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have measured the relative abundance of the B-subunits and mRNA transcripts of two Stx2 subtypes present in Shiga toxin-producing Escherichia coli (STEC) O157:H- strain E32511 using matrix-assisted laser desorption/ionization time-of-flight-time-of-flight tandem mass spectrometry (MALDI-TOF-TOF-M...

  12. Three Dimensional Wind Speed and Flux Measurement over a Rain-fed Soybean Field Using Orthogonal and Non-orthogonal Sonic Anemometer Designs

    NASA Astrophysics Data System (ADS)

    Thomas, T.; Suyker, A.; Burba, G. G.; Billesbach, D.

    2014-12-01

    The eddy covariance method for estimating fluxes of trace gases, energy and momentum in the constant flux layer above a plant canopy fundamentally relies on accurate measurements of the vertical wind speed. This wind speed is typically measured using a three dimensional ultrasonic anemometer. These anemometers incorporate designs with transducer sets that are aligned either orthogonally or non-orthogonally. Previous studies comparing the two designs suggest differences in measured 3D wind speed components, in particular vertical wind speed, from the non-orthogonal transducer relative to the orthogonal design. These differences, attributed to additional flow distortion caused by the non-orthogonal transducer arrangement, directly affect fluxes of trace gases, energy and momentum. A field experiment is being conducted over a rain-fed soybean field at the AmeriFlux site (US-Ne3) near Mead, Nebraska. In this study, ultrasonic anemometers featuring orthogonal transducer sets (ATI Vx Probe) and non-orthogonal transducer sets (Gill R3-100) collect high frequency wind vector and sonic temperature data. Sensible heat and momentum fluxes and other key sonic performance data are evaluated based on environmental parameters including wind speed, wind direction, temperature, and angle of attack. Preliminary field experiment results are presented.

  13. Sweet characterisation of prostate specific antigen using electrochemical lectin-based immunosensor assay and MALDI TOF/TOF analysis: Focus on sialic acid.

    PubMed

    Pihikova, Dominika; Pakanova, Zuzana; Nemcovic, Marek; Barath, Peter; Belicky, Stefan; Bertok, Tomas; Kasak, Peter; Mucha, Jan; Tkac, Jan

    2016-12-01

    The construction of a sensitive electrochemical lectin-based immunosensor for detection of a prostate specific antigen (PSA) is shown here. Three lectins with different carbohydrate specificities were used in this study to glycoprofile PSA, which is the most common biomarker for prostate cancer (PCa) diagnosis. The biosensor showed presence of α-L-fucose and α-(2,6)-linked terminal sialic acid within PSA´s glycan with high abundance, while only traces of α-(2,3)-linked terminal sialic acid were found. MALDI TOF/TOF mass spectrometry was applied to validate results obtained by the biosensor with a focus on determination of a type of sialic acid linkage by two methods. The first direct comparison of electrochemical immunosensor assay employing lectins for PSA glycoprofiling with mass spectrometric techniques is provided here and both methods show significant agreement. Thus, electrochemical lectin-based immunosensor has potential to be applied for prostate cancer diagnosis.

  14. Application of neural networks with orthogonal activation functions in control of dynamical systems

    NASA Astrophysics Data System (ADS)

    Nikolić, Saša S.; Antić, Dragan S.; Milojković, Marko T.; Milovanović, Miroslav B.; Perić, Staniša Lj.; Mitić, Darko B.

    2016-04-01

    In this article, we present a new method for the synthesis of almost and quasi-orthogonal polynomials of arbitrary order. Filters designed on the bases of these functions are generators of generalised quasi-orthogonal signals for which we derived and presented necessary mathematical background. Based on theoretical results, we designed and practically implemented generalised first-order (k = 1) quasi-orthogonal filter and proved its quasi-orthogonality via performed experiments. Designed filters can be applied in many scientific areas. In this article, generated functions were successfully implemented in Nonlinear Auto Regressive eXogenous (NARX) neural network as activation functions. One practical application of the designed orthogonal neural network is demonstrated through the example of control of the complex technical non-linear system - laboratory magnetic levitation system. Obtained results were compared with neural networks with standard activation functions and orthogonal functions of trigonometric shape. The proposed network demonstrated superiority over existing solutions in the sense of system performances.

  15. Real-time analysis of aromatics in combustion engine exhaust by resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS): a robust tool for chassis dynamometer testing.

    PubMed

    Adam, T W; Clairotte, M; Streibel, T; Elsasser, M; Pommeres, A; Manfredi, U; Carriero, M; Martini, G; Sklorz, M; Krasenbrink, A; Astorga, C; Zimmermann, R

    2012-07-01

    Resonance-enhanced multiphoton ionisation time-of-flight mass spectrometry (REMPI-TOF-MS) is a robust method for real-time analysis of monocyclic and polycyclic aromatic hydrocarbons in complex emissions. A mobile system has been developed which enables direct analysis on site. In this paper, we utilize a multicomponent calibration scheme based on the analytes' photo-ionisation cross-sections relative to a calibrated species. This allows semi-quantification of a great number of components by only calibrating one compound of choice, here toluene. The cross-sections were determined by injecting nebulised solutions of aromatic compounds into the TOF-MS ion source with the help of a HPLC pump. Then, REMPI-TOF-MS was implemented at various chassis dynamometers and test cells and the exhaust of the following vehicles and engines investigated: a compression ignition light-duty (LD) passenger car, a compression ignition LD van, two spark ignition LD passenger cars, 2 two-stroke mopeds, and a two-stroke engine of a string gas trimmer. The quantitative time profiles of benzene are shown. The results indicate that two-stroke engines are a significant source for toxic and cancerogenic compounds. Air pollution and health effects caused by gardening equipment might still be underestimated.

  16. Time expanding multihit TDC for the BELLE TOF detector at the KEK B-factory

    SciTech Connect

    Varner, G.; Kichimi, H.; Yamaguchi, H.

    1997-12-31

    Utilizing a time expansion technique, a multihit TDC has been developed for readout of the BELLE TOF detector at the KEK B-Factory. Time digitization consists of three steps: tagging an input signal with respect to a beam collision synchronized reference clock, expansion of this time interval, and readout by a conventional multihit TDC. Using a time expansion factor of 20 and a multihit TDC with a 500 ps LSB, this system provides a precision TOF measurement of 25 ps LSB, {approximately}20 ps resolution, and with a dead time of less than 1 {mu}s.

  17. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

    PubMed

    van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

    2016-05-01

    We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used.

  18. Routine identification of Nocardia species by MALDI-TOF mass spectrometry.

    PubMed

    Girard, Victoria; Mailler, Sandrine; Polsinelli, Sophie; Jacob, Delphine; Saccomani, Marie Christine; Celliere, Beatrice; Monnin, Valerie; van Belkum, Alex; Hagen, Ferry; Meis, Jacques F; Durand, Géraldine

    2017-01-01

    We here show adequate species identification for bacterial isolates of the genus Nocardia spp. through VITEK mass spectrometry. Application of a specific sample preparation method in combination with a robust matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) database leads to 94% accurate identification to the species level on a set of 164 isolates. The possibility to identify Nocardia spp. using MALDI-TOF MS will be available in the next release of VITEK MS update (IVD Version 3.0).

  19. The TOF-RPC for the BGO-EGG experiment at LEPS2

    NASA Astrophysics Data System (ADS)

    Tomida, N.; Tran, N.; Niiyama, M.; Ohnishi, H.; Hsieh, C.-Y.; Chu, M.-L.; Chang, W.-C.; Chen, J.-Y.; Matsumura, Y.; Shiraishi, K.; Hashimoto, T.

    2014-10-01

    We have developed Resistive Plate Chambers (RPCs) and the FEEs for the Time-of-Flight (TOF) system of the BGO-EGG experiment at LEPS2. The TOF system has an excellent time resolution of 50 ps with large readout strips of 2.5 × 100 cm2. The large readout strip and the signal combining technique enable us to cover the area of 6.4 m2 with only 256 channels of the readout electronics. The details of the RPC and the FEE are described in this article.

  20. The 237Np(n,f) cross section at the CERN n-TOF facility

    NASA Astrophysics Data System (ADS)

    Karadimos, D.; Vlastou, R.; Vlachoudis, V.; Pavlopoulos, P.; Konovalov, V.; Diakaki, M.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvár, F.; Benlliure, J.; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; de Albornoz, A. Carrillo; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Cortina, D.; Couture, A.; Cox, J.; David, S.; Dolfini, R.; Domingo-Pardo, C.; Dorochenko, A.; Dridi, W.; Duran, I.; Eleftheriadis, Ch.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fitzpatrick, L.; Frais-Koelbl, H.; Fujii, K.; Furman, W.; Goncalves, I.; Gallino, R.; Cennini, P.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Kolokolov, D.; Kossionides, E.; Krticka, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Sedysheva, M.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Voss, F.; Wendler, H.; Wiescher, M.; Wisshak, K.

    2011-10-01

    The 237Np(n,f) cross sections have been measured at the n-TOF facility relative to the 235U and 238U fission cross sections. The n-TOF spallation neutron source at CERN is characterized by a high intensity flux, an excellent time resolution and an extensive neutron energy range (from eV to GeV). A fast ionization chamber was used as a fission fragment detector with efficiency better than 97%. Preliminary 237Np(n,f) cross sections have been deduced in the energy range from 20 keV to 10 MeV and are found in good agreement with data from literature.

  1. Orthogonal self-assembly in folding block copolymers.

    PubMed

    Hosono, Nobuhiko; Gillissen, Martijn A J; Li, Yuanchao; Sheiko, Sergei S; Palmans, Anja R A; Meijer, E W

    2013-01-09

    We herein report the synthesis and characterization of ABA triblock copolymers that contain two complementary association motifs and fold into single-chain polymeric nanoparticles (SCPNs) via orthogonal self-assembly. The copolymers were prepared using atom-transfer radical polymerization (ATRP) and possess different pendant functional groups in the A and B blocks (alcohols in the A block and acetylenes in the B block). After postfunctionalization, the A block contains o-nitrobenzyl-protected 2-ureidopyrimidinone (UPy) moieties and the B block benzene-1,3,5-tricarboxamide (BTA) moieties. While the protected UPy groups dimerize after photoinduced deprotection of the o-nitrobenzyl group, the BTA moieties self-assemble into helical aggregates when temperature is reduced. In a two-step thermal/photoirradiation treatment under dilute conditions, the ABA block copolymer forms both BTA-based helical aggregates and UPy dimers intramolecularly. The sequential association of the two self-assembling motifs results in single-chain folding of the polymer, affording nanometer-sized particles with a compartmentalized interior. Variable-temperature NMR studies showed that the BTA and UPy self-assembly steps take place orthogonally (i.e., without mutual interference) in dilute solution. In addition, monitoring of the intramolecular self-assembly of BTA moieties into helical aggregates by circular dichroism spectroscopy showed that the stability of the aggregates is almost independent of UPy dimerization. Size-exclusion chromatography (SEC) and small-angle X-ray scattering analysis provided evidence of significant reductions in the hydrodynamic volume and radius of gyration, respectively, after photoinduced deprotection of the UPy groups; a 30-60% reduction in the size of the polymer chains was observed using SEC in CHCl(3). Molecular imaging by atomic force microscopy (AFM) corroborated significant contraction of individual polymer chains due to intramolecular association of the

  2. Compositions of orthogonal lysyl-tRNA and aminoacyl-tRNA synthetase pairs and uses thereof

    DOEpatents

    Anderson, J. Christopher; Wu, Ning; Santoro, Stephen; Schultz, Peter G

    2014-03-11

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal lysyl-tRNAs, orthogonal lysyl-aminoacyl-tRNA synthetases, and orthogonal pairs of lysyl-tRNAs/synthetases, which incorporate homoglutamines into proteins are provided in response to a four base codon. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with homoglutamines using these orthogonal pairs.

  3. Gas injected vacuum switch

    DOEpatents

    Hardin, K. Dan

    1977-01-01

    The disclosure relates to a gas injected vacuum switch comprising a housing having an interior chamber, a conduit for evacuating the interior chamber, within the chamber an anode and a cathode spaced from the anode, and a detonator for injecting electrically conductive gas into the chamber between the anode and the cathode to provide a current path therebetween.

  4. Injection rate control cam

    SciTech Connect

    Perr, J.P.; Liang, E.; Yu, R.C.; Ghuman, A.S.

    1990-10-16

    This patent describes a cam for controlling the injection rate of fuel in a fuel injection system of an engine. The fuel injection system including a cyclically operating unit injector having a body, an injector plunger mounted for reciprocating movement in the injector body between an advanced position and a retracted portion to pump into the engine during each cycle a variable quantity of fuel up to a maximum quantity under rated engine conditions, and a drive train for converting rotational movement of the cam into reciprocating movement of the pumping plunger depending on the profile of the cam. The cam profile comprises at least a plunger retraction segment and a plunger advancement segment for controlling the velocity if injector plunger retraction and advancement, respectively, the plunger advancement segment including a pre-injection subsequent shaped to cause an initial quantity of fuel to be injected into the engine during each cycle at rated engine conditions while the pre-injection subsegment is in contact with the drive train, and an injection subsegment following the pre-injection subsegment.

  5. Health Instruction Packages: Injections.

    ERIC Educational Resources Information Center

    Dunkleman, Ellie; And Others

    Text, illustrations, and exercises are utilized in this set of four learning modules designed to instruct nursing students in techniques and equipment utilized for intramuscular injections. The first module, "Equipment for Intramuscular Injections" by Ellie Dunkleman, presents guidelines for selecting needles of the proper length and…

  6. Orthogonally bifunctionalised polyacrylamide nanoparticles: a support for the assembly of multifunctional nanodevices

    NASA Astrophysics Data System (ADS)

    Giuntini, F.; Dumoulin, F.; Daly, R.; Ahsen, V.; Scanlan, E. M.; Lavado, A. S. P.; Aylott, J. W.; Rosser, G. A.; Beeby, A.; Boyle, R. W.

    2012-03-01

    Polyacrylamide nanoparticles bearing two orthogonal reactive functionalities were prepared by reverse microemulsion polymerisation. Water-soluble photosensitisers and peptide or carbohydrate moieties were sequentially attached to the new nanospecies by orthogonal conjugations based on copper-catalysed azide-alkyne cycloaddition and isothiocyanate chemistry.Polyacrylamide nanoparticles bearing two orthogonal reactive functionalities were prepared by reverse microemulsion polymerisation. Water-soluble photosensitisers and peptide or carbohydrate moieties were sequentially attached to the new nanospecies by orthogonal conjugations based on copper-catalysed azide-alkyne cycloaddition and isothiocyanate chemistry. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11947a

  7. Orthogonally referenced integrated ensemble for navigation and timing

    DOEpatents

    Smith, Stephen Fulton; Moore, James Anthony

    2014-04-01

    An orthogonally referenced integrated ensemble for navigation and timing includes a dual-polyhedral oscillator array, including an outer sensing array of oscillators and an inner clock array of oscillators situated inside the outer sensing array. The outer sensing array includes a first pair of sensing oscillators situated along a first axis of the outer sensing array, a second pair of sensing oscillators situated along a second axis of the outer sensing array, and a third pair of sensing oscillators situated along a third axis of the outer sensing array. The inner clock array of oscillators includes a first pair of clock oscillators situated along a first axis of the inner clock array, a second pair of clock oscillators situated along a second axis of the inner clock array, and a third pair of clock oscillators situated along a third axis of the inner clock array.

  8. Orthogonally referenced integrated ensemble for navigation and timing

    DOEpatents

    Smith, Stephen Fulton; Moore, James Anthony

    2013-02-26

    An orthogonally referenced integrated ensemble for navigation and timing includes a dual-polyhedral oscillator array, including an outer sensing array of oscillators and an inner clock array of oscillators situated inside the outer sensing array. The outer sensing array includes a first pair of sensing oscillators situated along a first axis of the outer sensing array, a second pair of sensing oscillators situated along a second axis of the outer sensing array, and a third pair of sensing oscillators situated along a third axis of the outer sensing array. The inner clock array of oscillators includes a first pair of clock oscillators situated along a first axis of the inner clock array, a second pair of clock oscillators situated along a second axis of the inner clock array, and a third pair of clock oscillators situated along a third axis of the inner clock array.

  9. Thermal shock characterization of tungsten deformed in two orthogonal directions

    NASA Astrophysics Data System (ADS)

    Pintsuk, G.; Prokhodtseva, A.; Uytdenhouwen, I.

    2011-10-01

    The increasing importance of tungsten and tungsten alloys for future nuclear fusion facilities and reactors requires an increasing understanding of the materials behavior under operational loading conditions. Among others this comprises the thermal shock and thermal fatigue resistance of the material before and after recrystallization. This study in particular aims for the qualification of deformed tungsten forged in two orthogonal directions intending to obtain a dense and nearly isotropic grain structure. The material is investigated in its stress relieved and recrystallized state and acts as a reference material for a better understanding of the cracking process when exposed to transient thermal loads, e.g. Edge Localized Modes (ELMs: f ⩾ 1 Hz, t = hundreds of μs). This is addressed by multiple thermal shock loadings in the electron beam facility JUDITH at different base temperatures. Hereby the influence of the DBTT on the onset of crack formation is verified and the latter qualified and quantified by metallographic means.

  10. Structure identification in pipe flow using proper orthogonal decomposition

    NASA Astrophysics Data System (ADS)

    Hellström, Leo H. O.; Smits, Alexander J.

    2017-03-01

    The energetic motions in direct numerical simulations of turbulent pipe flow at Reτ=685 are investigated using proper orthogonal decomposition. The procedure is extended such that a pressure component is identified in addition to the three-component velocity field for each mode. The pressure component of the modes is shown to align with the streamwise velocity component associated with the large-scale motions, where positive pressure coincides with positive streamwise velocity, and vice versa. The streamwise evolution of structures is then visualized using a conditional mode, which exhibit a strong similarity to the large-scale, low-momentum motions. A low-pressure region is present in the downstream section of the structure, and a high-pressure region is present in the upstream section.

  11. State diagram of an orthogonal spin transfer spin valve device

    SciTech Connect

    Ye, Li; Wolf, Georg; Pinna, Daniele; Chaves-O'Flynn, Gabriel D.; Kent, Andrew D.

    2015-05-21

    We present the switching characteristics of a spin-transfer device that incorporates a perpendicularly magnetized spin-polarizing layer with an in-plane magnetized free and fixed magnetic layer, known as an orthogonal spin transfer spin valve device. This device shows clear switching between parallel (P) and antiparallel (AP) resistance states and the reverse transition (AP → P) for both current polarities. Further, hysteretic transitions are shown to occur into a state with a resistance intermediate between that of the P and AP states, again for both current polarities. These unusual spin-transfer switching characteristics can be explained within a simple macrospin model that incorporates thermal fluctuations and considers a spin-polarized current that is tilted with respect to the free layer's plane, due to the presence of the spin-transfer torque from the polarizing layer.

  12. Orthogonal acoustic dimensions define auditory field maps in human cortex.

    PubMed

    Barton, Brian; Venezia, Jonathan H; Saberi, Kourosh; Hickok, Gregory; Brewer, Alyssa A

    2012-12-11

    The functional organization of human auditory cortex has not yet been characterized beyond a rudimentary level of detail. Here, we use functional MRI to measure the microstructure of orthogonal tonotopic and periodotopic gradients forming complete auditory field maps (AFMs) in human core and belt auditory cortex. These AFMs show clear homologies to subfields of auditory cortex identified in nonhuman primates and in human cytoarchitectural studies. In addition, we present measurements of the macrostructural organization of these AFMs into "clover leaf" clusters, consistent with the macrostructural organization seen across human visual cortex. As auditory cortex is at the interface between peripheral hearing and central processes, improved understanding of the organization of this system could open the door to a better understanding of the transformation from auditory spectrotemporal signals to higher-order information such as speech categories.

  13. Orthogonal predictions: follow-up questions for suggestive data.

    PubMed

    Walker, Alexander M

    2010-05-01

    When a biological hypothesis of causal effect can be inferred, the hypothesis can sometimes be tested in the selfsame database that gave rise to the study data from which the hypothesis grew. Valid testing happens when the inferred biological hypothesis has scientific implications that predict new relations between observations already recorded. Testing for the existence of the new relations is a valid assessment of the biological hypothesis, so long as the newly predicted relations are not a logical correlate of the observations that stimulated the hypothesis in the first place. These predictions that lead to valid tests might be called 'orthogonal' predictions in the data, and stand in marked contrast to 'scrawny' hypotheses with no biological content, which predict simply that the same data relations will be seen in a new database. The Universal Data Warehouse will shortly render moot searches for new databases in which to test.

  14. Asymptotic formulae for the zeros of orthogonal polynomials

    NASA Astrophysics Data System (ADS)

    Badkov, V. M.

    2012-09-01

    Let p_n(t) be an algebraic polynomial that is orthonormal with weight p(t) on the interval \\lbrack -1, 1 \\rbrack . When p(t) is a perturbation (in certain limits) of the Chebyshev weight of the first kind, the zeros of the polynomial p_n(\\cos\\tau) and the differences between pairs of (not necessarily consecutive) zeros are shown to satisfy asymptotic formulae as n\\to\\infty, which hold uniformly with respect to the indices of the zeros. Similar results are also obtained for perturbations of the Chebyshev weight of the second kind. First, some preliminary results on the asymptotic behaviour of the difference between two zeros of an orthogonal trigonometric polynomial, which are needed, are established. Bibliography: 15 titles.

  15. Orthogonal amplification of nanoparticles for improved diagnostic sensing.

    PubMed

    Peterson, Vanessa M; Castro, Cesar M; Lee, Hakho; Weissleder, Ralph

    2012-04-24

    There remains an ongoing need for fast, highly sensitive, and quantitative technologies that can detect and profile rare cells in freshly harvested samples. Recent developments in nanomaterial-based detection platforms provide advantages over traditional approaches in terms of signal sensitivity, stability, and the possibility for performing multiplexed measurements. Here, we describe a bioorthogonal, nanoparticle amplification technique capable of rapid augmentation of detection sensitivities by up to 1-2 orders of magnitude over current methods. This improvement in sensitivity was achieved by (i) significantly reducing background noise arising from nonspecific nanoparticle binding, (ii) increasing nanomaterial binding through orthogonal rounds of amplification, and (iii) implementing a cleavage step to improve assay robustness. The developed method allowed sensitive detection and molecular profiling of scant tumor cells directly in unpurified human clinical samples such as ascites. With its high sensitivity and simplified assay steps, this technique will likely have broad utility in nanomaterial-based diagnostics.

  16. Vectorial strain gauge method using single flexible orthogonal polydimethylsiloxane gratings

    NASA Astrophysics Data System (ADS)

    Guo, Hao; Tang, Jun; Qian, Kun; Tsoukalas, Dimitris; Zhao, Miaomiao; Yang, Jiangtao; Zhang, Binzhen; Chou, Xiujian; Liu, Jun; Xue, Chenyang; Zhang, Wendong

    2016-03-01

    A vectorial strain gauge method using a single sensing element is reported based on the double-sided polydimethylsiloxane (PDMS) Fraunhofer diffraction gratings structures. Using O2 plasma treatment steps, orthogonal wrinkled gratings were fabricated on both sides of a pre-strained PDMS film. Diffracted laser spots from this structure have been used to experimentally demonstrate, that any applied strain can be quantitatively characterized in both the x and y directions with an error of less than 0.6% and with a gauge factor of approximately 10. This simple and low cost technology which is completely different from the traditional vectorial strain gauge method, can be applied to surface vectorial strain measurement and multi-axis integrated mechanical sensors.

  17. Vectorial strain gauge method using single flexible orthogonal polydimethylsiloxane gratings.

    PubMed

    Guo, Hao; Tang, Jun; Qian, Kun; Tsoukalas, Dimitris; Zhao, Miaomiao; Yang, Jiangtao; Zhang, Binzhen; Chou, Xiujian; Liu, Jun; Xue, Chenyang; Zhang, Wendong

    2016-03-23

    A vectorial strain gauge method using a single sensing element is reported based on the double-sided polydimethylsiloxane (PDMS) Fraunhofer diffraction gratings structures. Using O2 plasma treatment steps, orthogonal wrinkled gratings were fabricated on both sides of a pre-strained PDMS film. Diffracted laser spots from this structure have been used to experimentally demonstrate, that any applied strain can be quantitatively characterized in both the x and y directions with an error of less than 0.6% and with a gauge factor of approximately 10. This simple and low cost technology which is completely different from the traditional vectorial strain gauge method, can be applied to surface vectorial strain measurement and multi-axis integrated mechanical sensors.

  18. Ultrasound vibrometry using orthogonal- frequency-based vibration pulses.

    PubMed

    Zheng, Yi; Yao, Aiping; Chen, Shigao; Urban, Matthew W; Lin, Haoming; Chen, Xin; Guo, Yanrong; Chen, Ke; Wang, Tianfu; Chen, Siping

    2013-11-01

    New vibration pulses are developed for shear wave generation in a tissue region with preferred spectral distributions for ultrasound vibrometry applications. The primary objective of this work is to increase the frequency range of detectable harmonics of the shear wave. The secondary objective is to reduce the required peak intensity of transmitted pulses that induce the vibrations and shear waves. Unlike the periodic binary vibration pulses, the new vibration pulses have multiple pulses in one fundamental period of the vibration. The pulses are generated from an orthogonal-frequency wave composed of several sinusoidal signals, the amplitudes of which increase with frequency to compensate for higher loss at higher frequency in tissues. The new method has been evaluated by studying the shear wave propagation in in vitro chicken and swine liver. The experimental results show that the new vibration pulses significantly increase tissue vibration with a reduced peak ultrasound intensity, compared with the binary vibration pulses.

  19. Rational design of orthogonal libraries of protein coding genes.

    PubMed

    Ryan, Daniel; Papamichail, Dimitris

    2013-05-17

    Array-based oligonucleotide synthesis technologies provide access to thousands of custom-designed sequence variants at low cost. Large-scale synthesis and high-throughput assays have become valuable experimental tools to study in detail the interplay between sequence and function. We have developed a methodology and corresponding algorithms for the design of diverse protein coding gene libraries, to exploit the potential of multiplex synthesis and help elucidate the effects of codon utilization and other factors in gene expression. Using our algorithm, we have computationally designed gene libraries with hundreds to thousands of orthogonal codon usage variants, uniformly exploring the design space of codon utilization, while demanding only a small fraction of the synthesis cost that would be required if these variants were synthesized independently.

  20. Orthogonal combination of local binary patterns for dynamic texture recognition

    NASA Astrophysics Data System (ADS)

    Chen, Yin; Guo, Xuejun; Klein, Dominik

    2015-12-01

    Dynamic texture (DT) is an extension of texture to the temporal domain. Recognizing DTs has received increasing attention. Volume local binary pattern (VLBP) is the most widely used descriptor for DTs. However, it is time consuming to recognize DTs using VLBP due to the large scale of data and the high dimensionality of the descriptor itself. In this paper, we propose a new operator called orthogonal combination of VLBP (OC-VLBP) for DT recognition. The original VLBP is decomposed both longitudinally and latitudinally, and then combined to constitute the OC-VLBP operator, so that the dimensionality of the original VLBP descriptor is lowered. The experimental results show that the proposed operator significantly reduces the computational costs of recognizing DTs without much loss in recognizing accuracy.

  1. Vectorial strain gauge method using single flexible orthogonal polydimethylsiloxane gratings

    PubMed Central

    Guo, Hao; Tang, Jun; Qian, Kun; Tsoukalas, Dimitris; Zhao, Miaomiao; Yang, Jiangtao; Zhang, Binzhen; Chou, Xiujian; Liu, Jun; Xue, Chenyang; Zhang, Wendong

    2016-01-01

    A vectorial strain gauge method using a single sensing element is reported based on the double-sided polydimethylsiloxane (PDMS) Fraunhofer diffraction gratings structures. Using O2 plasma treatment steps, orthogonal wrinkled gratings were fabricated on both sides of a pre-strained PDMS film. Diffracted laser spots from this structure have been used to experimentally demonstrate, that any applied strain can be quantitatively characterized in both the x and y directions with an error of less than 0.6% and with a gauge factor of approximately 10. This simple and low cost technology which is completely different from the traditional vectorial strain gauge method, can be applied to surface vectorial strain measurement and multi-axis integrated mechanical sensors. PMID:27005493

  2. Temporal extension of phase screen sequences using proper orthogonal decomposition

    NASA Astrophysics Data System (ADS)

    Henriksson, Markus; Sjöqvist, Lars; Tidström, Jonas

    2016-10-01

    For performance modelling of optical countermeasure systems simulation of turbulence effects is necessary. Physical optics numerical beam propagation using phase screens is an established method in this respect. In some cases a short sequence of temporally resolved phase screens is available from Computational Fluid Dynamics (CFD) simulations or from wavefront sensor measurements. It is, however, seldom possible to provide enough sequences and sufficient sequence length for Monte Carlo simulations of system performance utilizing these methods. Therefore, we have investigated the possibility to generate an arbitrary number of longer temporal sequences of phase screens with the same statistical properties for simulation of turbulence, based on an available short phase screen sequence. The method apply Proper Orthogonal Decomposition (POD), a method used to generate orthogonal modes from a dataset. For discretely sampled sequences the Singular Value Decomposition (SVD) algorithm is suitable to extract the set of POD modes. This scheme provides a separate temporal sequence of coefficients for each spatial mode. The next step is to generate new, longer temporal sequences of coefficients with the same statistical properties as those extracted by the SVD algorithm. Finally a new sequence of phase screens is generated by adding all spatial modes. The method is illustrated using data from CFD calculations of a down-scaled jet engine plume. The method is especially suitable for very strong localized turbulence as in aero optics and engine exhaust plumes, but may be useful also for extended turbulence. The use to generate Power-In-Bucket (PIB) sequences for evaluation of turbulence distortion effects is demonstrated. PIB is an important quantity when evaluating e.g. the performance of directed infrared countermeasure (DIRCM) systems.

  3. Compression of Laplacian pyramids through orthogonal transforms and improved prediction.

    PubMed

    Rath, Gagan; Yang, Wenxian; Guillemot, Christine

    2008-09-01

    Scalable representation of visual signals, such as image and video signals, has become a subject of active research since early 1980s. Scalability allows the adaptation of the bit rate and/or the resolution of the transmitted data to the network bandwidth and/or the rendering capability of the receiving device. For many years, spatial scalability has been achieved through wavelets, but recently the Laplacian pyramid (LP) has become an alternative choice because of reduced aliasing in the lower resolutions. In this paper, we focus on the coding efficiency of the LP with a view to transmitting it over a communication channel. In particular, we aim to improve the compression efficiency of the LP detail layers through improved interlayer prediction and orthogonal spatial transforms. First, we consider an LP in the open-loop configuration and propose to improve its rate-distortion performance by compressing it to a critically sampled representation. We derive four different orthogonal spatial transforms from the upsampling and downsampling filters that can achieve this representation, and apply them on the detail layers. The application of these transforms to the detail layers renders a fixed number of transform coefficients either zero or redundant, thus making their transmission unnecessary. Then we consider the compression of an LP in the closed-loop configuration through similar spatial transforms. Because of the introduction of quantization in the prediction loop, these spatial transforms applied on the detail layers do not produce the same number of zero or redundant transform coefficients as in the open-loop case. Nevertheless, the insight obtained from the open-loop coding leads us to enhance the interlayer prediction, and the subsequent application of the spatial transforms to the new detail layers aims to achieve better energy compaction.

  4. Orthogonal polynomial projection quantization: a new Hill determinant method

    NASA Astrophysics Data System (ADS)

    Handy, C. R.; Vrinceanu, D.

    2013-04-01

    Accurate energy eigenvalues are obtained by simply projecting the unknown bound state wave function on, essentially, arbitrary sets of orthogonal polynomials, and setting a subset of these to zero. The projection integrals are represented in terms of the power moments of the wave function, obtained recursively by transforming Schrödinger’s equation into a moment equation. Because unbounded wave functions do not have power moments, all solutions are guaranteed to be L2, resulting in a more robust, rapidly converging and stable method when compared with configuration space Hill determinant methods. More importantly, our approach permits the use of arbitrary, nonanalytic, positive reference functions, including those that manifest the true asymptotic behavior of the discrete states. These advantages are not usually possible with the standard Hill approach. The formulation presented here can be applied to any problem for which Schrödinger’s equation can be transformed into a moment equation. In this regard it is related to the L2 quantization prescription developed by Tymczak et al (1998 Phys. Rev. Lett. 80 3674; 1998 Phys. Rev. A 58 2708) corresponding to the Hill determinant method in momentum space, and to the eigenvalue moment method (Handy and Bessis 1985 Phys. Rev. Lett. 55 931; Handy et al 1988 Phys. Rev. Lett. 60 253), the first use of semidefinite programming related analysis in quantum physics. The latter method can be used to generate the ground state, whose orthogonal polynomials can serve to generate even more rapidly converging estimates for the excited discrete state energies. We demonstrate the power of this new approach on the sextic and quartic anharmonic oscillators, as well as on recently studied one- and two-dimensional pseudo-Hermitian Hamiltonians.

  5. A new orthogonal lead for P synchronous pacing.

    PubMed

    Goldreyer, B N; Olive, A L; Leslie, J; Cannom, D S; Wyman, M G

    1981-11-01

    P synchronous pacing has long been identified as advantageous for patients with atrioventricular conduction defects and intact sinus node function. Prior endocavitary systems have been infrequently employed, because of unreliable P wave sensing from standard ring electrodes in the atrium or the requirement for a second atrial sensing lead. A single endocardial lead employing a unipolar ventricular stimulating electrode and an orthogonal P wave sensing design was developed and tested in 22 patients undergoing electrophysiologic study or pacemaker implantation. Thirteen centimeters from the stimulating tip of a standard permanent pacing lead, three or four electrodes with a surface area of one millimeter squared, equidistant from the tip, were placed circumferentially about the catheter. With the catheter tip normally placed in the right ventricular apex, atrial sensing electrodes were positioned in the mid-high lateral right atrium, adjacent to, but not affixed to, the right atrial wall. Bipolar orthogonal leads X and Y were obtained. In 22 patients, during sinus rhythm, atrial electrogram voltages in the X axis of 2.47 plus or minus 1.6 millivolts and 2.32 plus or minus 1.6 millivolts in the Y axis were recorded. QRS voltages of 0.078 millivolts and 0.073 millivolts, respectively, allowed dramatic ability to discriminate P from QRS complexes (P/QRS equals 32/1). There was no change in QRS or unipolar ventricular pacing. A single catheter designed for P synchronous pacing employing circumferentially placed atrial sensing electrodes has demonstrated unique atrial sensing voltages with excellent QRS signal rejection.

  6. Laser-induced oxidation of cholesterol observed during MALDI-TOF mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Conditions for the detection of three odd-electron cholesterol oxidation peaks were determined and these peaks were shown to be artifacts of the matrix-assisted laser desorption time of flight (MALDI-TOF) process. Matrix choice, solvent, laser intensity and cholesterol concentration were systematica...

  7. New Insights for Diagnosis of Pineapple Fusariosis by MALDI-TOF MS Technique.

    PubMed

    Santos, Cledir; Ventura, José Aires; Lima, Nelson

    2016-08-01

    Fusarium is one of the most economically important fungal genus, since it includes many pathogenic species which cause a wide range of plant diseases. Morphological or molecular biology identification of Fusarium species is a limiting step in the fast diagnosis and treatment of plant disease caused by these fungi. Mass spectrometry by matrix-assisted laser/desorption ionisation-time-of-flight (MALDI-TOF)-based fingerprinting approach was applied to the fungal growth monitoring and direct detection of strain Fusarium guttiforme E-480 inoculated in both pineapple cultivars Pérola and Imperial side shoots, that are susceptible and resistant, respectively, to this fungal strain. MALDI-TOF MS technique was capable to detect fungal molecular mass peaks in the susceptible pineapple stem side shoot tissue. It is assumed that these molecular masses are mainly constituted by ribosomal proteins. MALDI-TOF-based fingerprinting approach has herein been demonstrated to be sensitive and accurate for the direct detection of F. guttiforme E-480 molecular masses on both susceptible and resistant pineapple side stem free of any pre-treatment. According to the results obtained, the changing on molecular mass peaks of infected susceptible pineapple tissue together with the possibility of fungal molecular masses analysis into this pineapple tissue can be a good indication for an early diagnosis by MALDI-TOF MS of pineapple fusariosis.

  8. MALDI-TOF Mass Spectrometry of Naturally-Occurring Mixtures of Mono- and Di-rhamnolipids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has been developed for high-throughput screening of naturally-occurring mixtures of rhamnolipids from Pseudomonas spp. Mono- and di-rhamnolipids are readily distinguished by characteristic molecular adduct i...

  9. Serum biomarker screening for the diagnosis of early gastric cancer using SELDI-TOF-MS.

    PubMed

    Li, Ping; Zhang, Dianliang; Guo, Chunbao

    2012-06-01

    In this study, we performed a proteomic analysis of sera from stage I gastric cancer patients using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and established a diagnostic model for the early diagnosis of stage I gastric cancer. Serum samples from 169 gastric cancer patients and 83 age- and gender-matched healthy individuals were analyzed by SELDI-TOF-MS ProteinChip array technology. The SELDI-TOF-MS spectral data were analyzed using the Biomarker Wizard™ and Biomarker Patterns™ software to find differential proteins and develop a classification tree for gastric cancer. A total of 34 mass peaks were identified. Six peaks at a mass-to-charge ratio (m/z) of 2873, 3163, 4526, 5762, 6121 and 7778 were used to construct the diagnostic model. The model effectively distinguished gastric cancer samples from control samples, achieving a sensitivity and specificity of 93.49 and 91.57%, respectively. In addition, we identified 3 of the 6 protein peaks at 2873, 6121 and 7778 m/z, which distinguished between stage I and stage II/III/IV gastric cancer. The model had an accuracy of 88.89% for the identification of stage I gastric cancer. In conclusion, the diagnostic model for the detection of serum proteins by SELDI-TOF-MS ProteinChip array technology correctly distinguishes gastric cancer from healthy samples, and has the ability to screen and distinguish between early gastric cancer from advanced gastric cancer.

  10. A multiplexed TOF and DOI capable PET detector using a binary position sensitive network

    NASA Astrophysics Data System (ADS)

    Bieniosek, M. F.; Cates, J. W.; Levin, C. S.

    2016-11-01

    Time of flight (TOF) and depth of interaction (DOI) capabilities can significantly enhance the quality and uniformity of positron emission tomography (PET) images. Many proposed TOF/DOI PET detectors require complex readout systems using additional photosensors, active cooling, or waveform sampling. This work describes a high performance, low complexity, room temperature TOF/DOI PET module. The module uses multiplexed timing channels to significantly reduce the electronic readout complexity of the PET detector while maintaining excellent timing, energy, and position resolution. DOI was determined using a two layer light sharing scintillation crystal array with a novel binary position sensitive network. A 20 mm effective thickness LYSO crystal array with four 3 mm  ×  3 mm silicon photomultipliers (SiPM) read out by a single timing channel, one energy channel and two position channels achieved a full width half maximum (FWHM) coincidence time resolution of 180  ±  2 ps with 10 mm of DOI resolution and 11% energy resolution. With sixteen 3 mm  ×  3 mm SiPMs read out by a single timing channel, one energy channel and four position channels a coincidence time resolution 204  ±  1 ps was achieved with 10 mm of DOI resolution and 15% energy resolution. The methods presented here could significantly simplify the construction of high performance TOF/DOI PET detectors.

  11. MALDI-TOF MS distinctly differentiates nontypable Haemophilus influenzae from Haemophilus haemolyticus.

    PubMed

    Zhu, Bingqing; Xiao, Di; Zhang, Huifang; Zhang, Yongchan; Gao, Yuan; Xu, Li; Lv, Jing; Wang, Yingtong; Zhang, Jianzhong; Shao, Zhujun

    2013-01-01

    Nontypable Haemophilus influenzae (NTHi) and Haemophilus haemolyticus exhibit different pathogenicities, but to date, there remains no definitive and reliable strategy for differentiating these strains. In this study, we evaluated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a potential method for differentiating NTHi and H. haemolyticus. The phylogenetic analysis of concatenated 16S rRNA and recombinase A (recA) gene sequences, outer membrane protein P6 gene sequencing and single-gene PCR were used as reference methods. The original reference database (ORD, provided with the Biotyper software) and new reference database (NRD, extended with Chinese strains) were compared for the evaluation of MALDI-TOF MS. Through a search of the ORD, 76.9% of the NTHi (40/52) and none of the H. haemolyticus (0/20) strains were identified at the species level. However, all NTHi and H. haemolyticus strains used for identification were accurately recognized at the species level when searching the NRD. From the dendrogram clustering of the main spectra projections, the Chinese and foreign H. influenzae reference strains were categorized into two distinct groups, and H. influenzae and H. haemolyticus were also separated into two categories. Compared to the existing methods, MALDI-TOF MS has the advantage of integrating high throughput, accuracy and speed. In conclusion, MALDI-TOF MS is an excellent method for differentiating NTHi and H. haemolyticus. This method can be recommended for use in appropriately equipped laboratories.

  12. The Ongoing Revolution of MALDI-TOF Mass Spectrometry for Microbiology Reaches Tropical Africa

    PubMed Central

    Fall, Bécaye; Lo, Cheikh Ibrahima; Samb-Ba, Bissoume; Perrot, Nadine; Diawara, Silman; Gueye, Mamadou Wague; Sow, Kowry; Aubadie-Ladrix, Maxence; Mediannikov, Oleg; Sokhna, Cheikh; Diemé, Yaya; Chatellier, Sonia; Wade, Boubacar; Raoult, Didier; Fenollar, Florence

    2015-01-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) represents a revolution in routine pathogen identification in clinical microbiology laboratories. A MALDI-TOF MS was introduced to tropical Africa in the clinical microbiology laboratory of the Hôpital Principal de Dakar (Senegal) and used for routine pathogen identification. Using MS, 2,429 bacteria and fungi isolated from patients were directly assayed, leading to the identification of 2,082 bacteria (85.7%) and 206 fungi (8.5%) at the species level, 109 bacteria (4.5%) at the genus level, and 16 bacteria (0.75%) at the family level. Sixteen isolates remained unidentified (0.75%). Escherichia coli was the most prevalent species (25.8%) followed by Klebsiella pneumoniae (14.8%), Streptococcus agalactiae (6.2%), Acinetobacter baumannii (6.1%), Pseudomonas aeruginosa (5.9%), and Staphylococcus aureus (5.9%). MALDI-TOF MS has also enabled the detection of rare bacteria and fungi. MALDI-TOF MS is a powerful tool for the identification of bacterial and fungal species involved in infectious diseases in tropical Africa. PMID:25601995

  13. A High-Throughput MALDI-TOF Mass Spectrometry-Based Assay of Chitinase Activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A high-throughput MALDI-TOF mass spectrometric assay is described for assay of chitolytic enzyme activity. The assay uses unmodified chitin oligosaccharide substrates, and is readily achievable on a microliter scale (2 µL total volume, containing 2 µg of substrate and 1 ng of protein). The speed a...

  14. Molecular weight evaluation of poly-dimethylsiloxane on solid surfaces using silver deposition/TOF-SIMS

    NASA Astrophysics Data System (ADS)

    Inoue, Masae; Murase, Atsushi

    2004-06-01

    Molecular ions include information about end groups, functional groups and molecular weight. A method for directly detecting this in the high-mass region of the spectrum (>1000 amu) from poly-dimethylsiloxane (PDMS) on a solid surface was investigated. It was found that a TOF-SIMS analysis of silver-deposited surfaces (silver deposition/TOF-SIMS) is useful for this purpose. Two methods for silver deposition, the diode sputtering method and the vacuum evaporation coating method, were tried. The former required the sample to be cooled so as to prevent the damage of the sample surface due to thermal oxidation; the latter caused no damage to sample surfaces at room temperature. Using silver deposition/TOF-SIMS analysis, silver-cationized quasi-molecular ions were clearly detected from PDMS on solid surfaces and their images were observed without the interference of deposited silver. By applying to the analysis of paint defects, etc., it was confirmed that this technique is useful to analyze practical industrial materials. Silver-cationized ions were detected not only from PDMS, but also from other organic materials, such as some kinds of lubricant additives and fluorine oils on solid surfaces. Therefore, silver deposition/TOF-SIMS was proved to be useful for the analysis of thin substances on solid surfaces.

  15. Comparison of imipenem and meropenem antibiotics for the MALDI-TOF MS detection of carbapenemase activity.

    PubMed

    Rotova, Veronika; Papagiannitsis, Costas C; Skalova, Anna; Chudejova, Katerina; Hrabak, Jaroslav

    2017-04-05

    A comparison of carbapenem molecules for the detection of carbapenemase-producing bacteria by MALDI-TOF MS showed that imipenem exhibited higher sensitivity (97%) and specificity (100%) scores for Pseudomonas aeruginosa than meropenem. However, meropenem was more efficient (98% sensitivity and 100% specificity) against Enterobacteriaceae.

  16. Density profile in thin films of polybutadiene on silicon oxide substrates: a TOF-NR study.

    PubMed

    Hoppe, E Tilo; Sepe, Alessandro; Haese-Seiller, Martin; Moulin, Jean-François; Papadakis, Christine M

    2013-08-27

    We have investigated thin films from fully deuterated polybutadiene (PB-d6) on silicon substrates with the aim of detecting and characterizing a possible interphase in the polymer film near the substrate using time-of-flight neutron reflectometry (TOF-NR). As substrates, thermally oxidized silicon wafers were either used as such or they were coated with triethylethoxysilyl modified 1,2-PB prior to deposition of the PB-d6 film. TOF-NR reveals that, for both substrates, the scattering length density (SLD) of the PB films decreases near the solid interface. The reduction of SLD is converted to an excess fraction of free volume. To further verify the existence of the interphase in PB-d6, we attempt to model the TOF-NR curves with density profiles which do not feature an interphase. These density profiles do not describe the TOF-NR curves adequately. We conclude that, near the solid interface, an interphase having an SLD lower than the bulk of the film is present.

  17. Detection of Rickettsia spp in Ticks by MALDI-TOF MS

    PubMed Central

    Yssouf, Amina; Almeras, Lionel; Terras, Jérôme; Socolovschi, Cristina; Raoult, Didier; Parola, Philippe

    2015-01-01

    Background Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown to be an effective tool for the rapid identification of arthropods, including tick vectors of human diseases. Methodology/Principal Findings The objective of the present study was to evaluate the use of MALDI-TOF MS to identify tick species, and to determine the presence of rickettsia pathogens in the infected Ticks. Rhipicephalus sanguineus and Dermacentor marginatus Ticks infected or not by R. conorii conorii or R. slovaca, respectively, were used as experimental models. The MS profiles generated from protein extracts prepared from tick legs exhibited mass peaks that distinguished the infected and uninfected Ticks, and successfully discriminated the Rickettsia spp. A blind test was performed using Ticks that were laboratory-reared, collected in the field or removed from patients and infected or not by Rickettsia spp. A query against our in-lab arthropod MS reference database revealed that the species and infection status of all Ticks were correctly identified at the species and infection status levels. Conclusions/Significance Taken together, the present work demonstrates the utility of MALDI-TOF MS for a dual identification of tick species and intracellular bacteria. Therefore, MALDI-TOF MS is a relevant tool for the accurate detection of Rickettsia spp in Ticks for both field monitoring and entomological diagnosis. The present work offers new perspectives for the monitoring of other vector borne diseases that present public health concerns. PMID:25659152

  18. A multiplexed TOF and DOI capable PET detector using a binary position sensitive network.

    PubMed

    Bieniosek, M F; Cates, J W; Levin, C S

    2016-11-07

    Time of flight (TOF) and depth of interaction (DOI) capabilities can significantly enhance the quality and uniformity of positron emission tomography (PET) images. Many proposed TOF/DOI PET detectors require complex readout systems using additional photosensors, active cooling, or waveform sampling. This work describes a high performance, low complexity, room temperature TOF/DOI PET module. The module uses multiplexed timing channels to significantly reduce the electronic readout complexity of the PET detector while maintaining excellent timing, energy, and position resolution. DOI was determined using a two layer light sharing scintillation crystal array with a novel binary position sensitive network. A 20 mm effective thickness LYSO crystal array with four 3 mm  ×  3 mm silicon photomultipliers (SiPM) read out by a single timing channel, one energy channel and two position channels achieved a full width half maximum (FWHM) coincidence time resolution of 180  ±  2 ps with 10 mm of DOI resolution and 11% energy resolution. With sixteen 3 mm  ×  3 mm SiPMs read out by a single timing channel, one energy channel and four position channels a coincidence time resolution 204  ±  1 ps was achieved with 10 mm of DOI resolution and 15% energy resolution. The methods presented here could significantly simplify the construction of high performance TOF/DOI PET detectors.

  19. SELDI-TOF analysis of glioblastoma cyst fluid is an approach for assessing cellular protein expression

    PubMed Central

    Hoelscher, Martin; Richter, Nina; Melle, Christian; von Eggeling, Ferdinand; Schaenzer, Anne; Nestler, Ulf

    2013-01-01

    Objectives: In about 10% of glioblastoma patients, preoperative MRI discloses the presence of tumor cysts. Whereas the impact of cystic appearance on prognosis has been discussed extensively, only little is known about the tumor cyst fluid. In this study, we tested the feasibility of the surface enhanced laser desorption ionization time of flight (SELDI-TOF) technique to detect cyst fluid proteins. Methods: Cyst fluid was collected from 21 glioblastoma patients for SELDI-TOF analysis and compared to control cerebrospinal fluids from 15 patients with spinal stenosis. Resulting protein peaks with significant differences between groups were further described, using the molecular weight in an internet search of protein databases and publications. Two potential cyst fluid proteins, basigin and ferritin light chain, were selected for immunohistological detection in the histologic slides of the patients, metallothionein (MT) served as negative control. Results: As supposed from the results of the SELDI-TOF analysis, basigin and ferritin were detected immunohistochemically in the cyst wall, whereas MT was more equally distributed between the cyst wall and the surrounding tumor tissue. Median survival time of the patients was 20 months (range 2 to 102 months) and correlated with age, but not with expression of the three proteins. Discussion: The SELDI-TOF approach reveals a number of proteins, potentially present in glioblastoma cyst fluid. Identification of these proteins in tumor cells may help understand the pathogenetic pathways and the prognostic value of cystic changes. PMID:24225180

  20. GC/TOF-MS as a new method for halocarbon observation in the atmosphere

    NASA Astrophysics Data System (ADS)

    Obersteiner, Florian; Boenisch, Harald; Hoker, Jesica; Engel, Andreas

    2015-04-01

    The need for halocarbon measurements in the atmosphere arose with the anthropogenic emission of CFCs beginning in the 1950s and the discovery of their ozone depleting potential in the 1980s. CFCs were replaced by HCFCs and are nowadays replaced by HFCs, with new compounds continuously being developed and introduced to the atmosphere. While not being harmful to the ozone layer, HFCs are still greenhouse gases and many tend to be hazardous to human health at high concentration. They can also serve as tracers to study atmospheric transport at low concentration, making high precision measurement interesting to atmospheric studies. Gas chromatography coupled with time-of-flight mass spectrometry (GC/TOF-MS) is still a new method in the field of atmospheric halocarbon measurement compared to the well-established GC/QP(quadrupole)-MS. The QP-MS is indeed a very stable and easy-to-operate instrument but also limited by mass resolution and either mass range or sensitivity. We will present the general applicability of GC/TOF-MS to regular halocarbon observation by a time series of halocarbon measurements from the Taunus Observatory (Kleiner Feldberg, Germany) and the implementation of a second, high-resolution (max. R=4000) TOF-MS system. Both GC/TOF-MS systems are characterized with respect to reproducibility, non-linearity and limits of detection (LOD). Furthermore, the advantages of a higher mass resolution are demonstrated with respect to LOD, substance identification and substance quantification.

  1. The ongoing revolution of MALDI-TOF mass spectrometry for microbiology reaches tropical Africa.

    PubMed

    Fall, Bécaye; Lo, Cheikh Ibrahima; Samb-Ba, Bissoume; Perrot, Nadine; Diawara, Silman; Gueye, Mamadou Wague; Sow, Kowry; Aubadie-Ladrix, Maxence; Mediannikov, Oleg; Sokhna, Cheikh; Diemé, Yaya; Chatellier, Sonia; Wade, Boubacar; Raoult, Didier; Fenollar, Florence

    2015-03-01

    Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) represents a revolution in routine pathogen identification in clinical microbiology laboratories. A MALDI-TOF MS was introduced to tropical Africa in the clinical microbiology laboratory of the Hôpital Principal de Dakar (Senegal) and used for routine pathogen identification. Using MS, 2,429 bacteria and fungi isolated from patients were directly assayed, leading to the identification of 2,082 bacteria (85.7%) and 206 fungi (8.5%) at the species level, 109 bacteria (4.5%) at the genus level, and 16 bacteria (0.75%) at the family level. Sixteen isolates remained unidentified (0.75%). Escherichia coli was the most prevalent species (25.8%) followed by Klebsiella pneumoniae (14.8%), Streptococcus agalactiae (6.2%), Acinetobacter baumannii (6.1%), Pseudomonas aeruginosa (5.9%), and Staphylococcus aureus (5.9%). MALDI-TOF MS has also enabled the detection of rare bacteria and fungi. MALDI-TOF MS is a powerful tool for the identification of bacterial and fungal species involved in infectious diseases in tropical Africa.

  2. Silicon detectors for monitoring neutron beams in n-TOF beamlines

    SciTech Connect

    Cosentino, L.; Pappalardo, A.; Piscopo, M.; Finocchiaro, P.; Musumarra, A.; Barbagallo, M.; Colonna, N.; Damone, L.

    2015-07-15

    During 2014, the second experimental area (EAR2) was completed at the n-TOF neutron beam facility at CERN (n-TOF indicates neutron beam measurements by means of time of flight technique). The neutrons are produced via spallation, by means of a high-intensity 20 GeV pulsed proton beam impinging on a thick target. The resulting neutron beam covers the energy range from thermal to several GeV. In this paper, we describe two beam diagnostic devices, both exploiting silicon detectors coupled with neutron converter foils containing {sup 6}Li. The first one is based on four silicon pads and allows monitoring of the neutron beam flux as a function of the neutron energy. The second one, in beam and based on position sensitive silicon detectors, is intended for the reconstruction of the beam profile, again as a function of the neutron energy. Several electronic setups have been explored in order to overcome the issues related to the gamma flash, namely, a huge pulse present at the start of each neutron bunch which may blind the detectors for some time. The two devices were characterized with radioactive sources and also tested at the n-TOF facility at CERN. The wide energy and intensity range they proved capable of sustaining made them attractive and suitable to be used in both EAR1 and EAR2 n-TOF experimental areas, where they became immediately operational.

  3. MALDI-TOF mass spectrometry for early identification of bacteria grown in blood culture bottles.

    PubMed

    Zabbe, Jean-Benoît; Zanardo, Laura; Mégraud, Francis; Bessède, Emilie

    2015-08-01

    This note reports an interesting way to rapidly identify bacteria grown from blood culture bottles. Chocolate agar plates were inoculated with 1 drop of the positive blood bottle medium. After a 3-hour incubation, the growth veil was submitted to MALDI-TOF mass spectrometry: 77% of the bacteria present have been correctly identified.

  4. THE RHIC INJECTION SYSTEM.

    SciTech Connect

    FISCHER,W.; GLENN,J.W.; MACKAY,W.W.; PTITSIN,V.; ROBINSON,T.G.; TSOUPAS,N.

    1999-03-29

    The RHIC injection system has to transport beam from the AGS-to-RHIC transfer line onto the closed orbits of the RHIC Blue and Yellow rings. This task can be divided into three problems. First, the beam has to be injected into either ring. Second, once injected the beam needs to be transported around the ring for one turn. Third, the orbit must be closed and coherent beam oscillations around the closed orbit should be minimized. We describe our solutions for these problems and report on system tests conducted during the RHIC Sextant test performed in 1997. The system will be fully commissioned in 1999.

  5. CALIOP-derived Smoke Plume Injection Height

    NASA Astrophysics Data System (ADS)

    Soja, A. J.; Winker, D. M.; Choi, H. D.; Fairlie, T. D.; Westberg, D. J.; Roller, C. M.; Pouliot, G.; Vaughan, M.; Pierce, T. E.; Trepte, C. R.; Rao, V.

    2014-12-01

    Biomass burning is a dominant natural and anthropogenic disturbance that feeds back to the climate system. Fire regimes, ecosystem fuels, fire severity and intensity vary widely, even within the same system, largely under the control of weather and climate. These strongly influence fire plume injection height and thus the transport of related biomass burning emissions, affecting air quality, human health and the climate system. If our knowledge of plume injection height is incorrect, transport models of those emissions will likewise be incorrect, adversely affecting our ability to analyze and predict climate feedbacks (i.e. black carbon to the Arctic, precipitation, cloud-radiation relationships) and public health (air quality forecast). Historically, plume height was based on the pioneering work of G.A. Briggs [1969; 1971] and verified with limited field campaigns. However, we currently have two satellite instruments, Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) onboard CALIPSO (afternoon overpass) and Multi-angle Imaging SpectroRadiometer (MISR) onboard TERRA (morning overpass), that can provide the statistics necessary to verify our assumptions and improve fire plume injection height estimates for use in both small- and large-scale models. We have developed a methodology to assess fire plume injection height using the Langley Trajectory Model (LaTM), CALIOP, Hazard Mapping System (HMS) smoke plume, and MODerate Resolution Imaging Spectrometer (MODIS) thermal anomaly data that is capable of generating two distinct types of verification data. A single CALIOP smoke-filled aerosol envelop can be traced back to numerous fire events, and using multiple CALIOP transects from numerous days, a daily smoke plume injection height evolution from a single fire can be defined. Additionally, we have linked the smoke plumes to ecosystems and the meteorological variables that define fire weather. In concert, CALIOP and MISR data can produce the statistical knowledge

  6. Common injections in musculoskeletal medicine.

    PubMed

    Monseau, Aaron J; Nizran, Parminder Singh

    2013-12-01

    Musculoskeletal injections are a common procedure in primary care and sports medicine but can be intimidating for some clinicians. This article addresses current evidence for corticosteroid injections, and common injection indications and techniques, namely knee, subacromial bursa, glenohumeral joint, lateral epicondyle, de Quervain tenosynovitis, and greater trochanteric bursa injections. Preparation for injections and some evidence for ultrasound guidance are also reviewed.

  7. Rapid and accurate bacterial identification in probiotics and yoghurts by MALDI-TOF mass spectrometry.

    PubMed

    Angelakis, Emmanouil; Million, Matthieu; Henry, Mireille; Raoult, Didier

    2011-10-01

    Probiotic food is manufactured by adding probiotic strains simultaneously with starter cultures in fermentation tanks. Here, we investigate the accuracy and feasibility of matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) for bacterial identification at the species level in probiotic food and yoghurts. Probiotic food and yoghurts were cultured in Columbia and Lactobacillus specific agar and tested by quantitative real-time PCR (qPCR) for the detection and quantification of Lactobacillus sp. Bacterial identification was performed by MALDI-TOF analysis and by amplification and sequencing of tuf and 16S rDNA genes. We tested 13 probiotic food and yoghurts and we identified by qPCR that they presented 10(6) to 10(7) copies of Lactobacillus spp. DNA/g. All products contained very large numbers of living bacteria varying from 10(6) to 10(9) colony forming units/g. These bacteria were identified as Lactobacillus casei, Lactococcus lactis, Bifidobacterium animalis, Lactobacillus delbrueckii, and Streptococcus thermophilus. MALDI-TOF MS presented 92% specificity compared to the molecular assays. In one product we found L. lactis, instead of Bifidus spp. which was mentioned on the label and for another L. delbrueckii and S. thermophilus instead of Bifidus spp. MALDI-TOF MS allows a rapid and accurate bacterial identification at the species level in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified. Practical Application:  MALDI-TOF MS is rapid and specific for the identification of bacteria in probiotic food and yoghurts. Although the safety and functionality of probiotics are species and strain dependent, we found a discrepancy between the bacterial strain announced on the label and the strain identified.

  8. Design considerations for a limited angle, dedicated breast, TOF PET scanner

    NASA Astrophysics Data System (ADS)

    Surti, S.; Karp, J. S.

    2008-06-01

    Development of partial ring, dedicated breast positron emission tomography (PET) scanners is an active area of research. Due to the limited angular coverage, generation of distortion and artifact-free, fully 3D tomographic images is not possible without rotation of the detectors. With time-of-flight (TOF) information, it is possible to achieve the 3D tomographic images with limited angular coverage and without detector rotation. We performed simulations for a breast scanner design with a ring diameter and an axial length of 15 cm and comprising a full (180° in-plane angular coverage), 2/3 (120° in-plane angular coverage) or 1/2 (90° in-plane angular coverage) ring detector. Our results show that as the angular coverage decreases, improved timing resolution is needed to achieve distortion-free and artifact-free images with TOF. The contrast recovery coefficient (CRC) value for small hot lesions in a partial ring scanner is similar to a full ring non-TOF scanner. Our results indicate that a timing resolution of 600 ps is needed for a 2/3 ring scanner, while a timing resolution of 300 ps is needed for a 1/2 ring scanner. We also analyzed the ratio of lesion CRC to the background pixel noise (SNR) and concluded that TOF improves the SNR values of the partial ring scanner, and helps to compensate for the loss in sensitivity due to reduced geometric sensitivity in a limited angle coverage PET scanner. In particular, it is possible to maintain similar SNR characteristic in a 2/3 ring scanner with a timing resolution of 300 ps as in a full ring non-TOF scanner.

  9. Reliable identification at the species level of Brucella isolates with MALDI-TOF-MS

    PubMed Central

    2011-01-01

    Background The genus Brucella contains highly infectious species that are classified as biological threat agents. The timely detection and identification of the microorganism involved is essential for an effective response not only to biological warfare attacks but also to natural outbreaks. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is a rapid method for the analysis of biological samples. The advantages of this method, compared to conventional techniques, are rapidity, cost-effectiveness, accuracy and suitability for the high-throughput identification of bacteria. Discrepancies between taxonomy and genetic relatedness on the species and biovar level complicate the development of detection and identification assays. Results In this study, the accurate identification of Brucella species using MALDI-TOF-MS was achieved by constructing a Brucella reference library based on multilocus variable-number tandem repeat analysis (MLVA) data. By comparing MS-spectra from Brucella species against a custom-made MALDI-TOF-MS reference library, MALDI-TOF-MS could be used as a rapid identification method for Brucella species. In this way, 99.3% of the 152 isolates tested were identified at the species level, and B. suis biovar 1 and 2 were identified at the level of their biovar. This result demonstrates that for Brucella, even minimal genomic differences between these serovars translate to specific proteomic differences. Conclusions MALDI-TOF-MS can be developed into a fast and reliable identification method for genetically highly related species when potential taxonomic and genetic inconsistencies are taken into consideration during the generation of the reference library. PMID:22192890

  10. Orthogonality of Bethe Ansatz Eigenfunctions for the Laplacian on a Hyperoctahedral Weyl Alcove

    NASA Astrophysics Data System (ADS)

    van Diejen, J. F.; Emsiz, E.

    2017-03-01

    We prove the orthogonality of the Bethe Ansatz eigenfunctions for the Laplacian on a hyperoctahedral Weyl alcove with repulsive homogeneous Robin boundary conditions at the walls. To this end these eigenfunctions are retrieved as the continuum limit of an orthogonal basis of algebraic Bethe Ansatz eigenfunctions for a finite {q}-boson system endowed with diagonal open-end boundary interactions.

  11. Sensitivity Simulation of Compressed Sensing Based Electronic Warfare Receiver Using Orthogonal Matching Pursuit Algorithm

    DTIC Science & Technology

    2016-02-01

    AFRL-RY-WP-TR-2016-0006 SENSITIVITY SIMULATION OF COMPRESSED SENSING BASED ELECTRONIC WARFARE RECEIVER USING ORTHOGONAL MATCHING PURSUIT...TITLE AND SUBTITLE SENSITIVITY SIMULATION OF COMPRESSED SENSING BASED ELECTRONIC WARFARE RECEIVER USING ORTHOGONAL MATCHING PURSUIT ALGORITHM 5a...August 2014. Report contains color. 14. ABSTRACT The wideband coverage of the traditional fast Fourier transform (FFT)-based electronic warfare

  12. RESEARCH NOTE: Orthogonality and mean squares of the vector fields given by spherical cap harmonic potentials

    NASA Astrophysics Data System (ADS)

    Lowes, F. J.

    1999-03-01

    It is well known that the vector fields derived from spherical harmonics are orthogonal over the sphere. It is now shown that the vector fields derived from spherical cap harmonics are orthogonal over the cap, to the same extent as the cap potentials are, and expressions are given for their mean squares.

  13. One-parameter extension of the Doi-Peliti formalism and its relation with orthogonal polynomials.

    PubMed

    Ohkubo, Jun

    2012-10-01

    An extension of the Doi-Peliti formalism for stochastic chemical kinetics is proposed. Using the extension, path-integral expressions consistent with previous studies are obtained. In addition, the extended formalism is naturally connected to orthogonal polynomials. We show that two different orthogonal polynomials, i.e., Charlier polynomials and Hermite polynomials, can be used to express the Doi-Peliti formalism explicitly.

  14. A note on the zeros of Freud-Sobolev orthogonal polynomials

    NASA Astrophysics Data System (ADS)

    Moreno-Balcazar, Juan J.

    2007-10-01

    We prove that the zeros of a certain family of Sobolev orthogonal polynomials involving the Freud weight function e-x4 on are real, simple, and interlace with the zeros of the Freud polynomials, i.e., those polynomials orthogonal with respect to the weight function e-x4. Some numerical examples are shown.

  15. 2D nearly orthogonal mesh generation with controls on distortion functions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method to control the distortion function of the Ryskin and Leal (RL) orthogonal mesh generation system is presented. The proposed method considers the effects from not only the local orthogonal condition but also the local smoothness condition (the geometry and the mesh size) on the distortion fu...

  16. OnabotulinumtoxinA Injection

    MedlinePlus

    ... years of age and older; treat severe underarm sweating in people 18 years of age and older ... the muscle. When onabotulinumtoxinA is injected into a sweat gland, it decreases the activity of the gland ...

  17. Collagenase Clostridium Histolyticum Injection

    MedlinePlus

    ... disease (a thickening of tissue [plaque] inside the penis that causes the penis to curve). Collagenase Clostridium histolyticum injection is in ... the plaque of thickened tissue and allows the penis to be straightened.

  18. Sipuleucel-T Injection

    MedlinePlus

    ... doctor or nurse in a doctor's office or infusion center. It is usually given once every 2 ... injection may cause serious allergic reactions during an infusion and for about 30 minutes afterwards. A doctor ...

  19. Albumin injection (image)

    MedlinePlus

    ... a nuclear scan test that is performed to measure the supply of blood through the lungs. After the injection, the lungs are scanned to detect the location of the radioactive particles as blood flows through the lungs.

  20. Talimogene Laherparepvec Injection

    MedlinePlus

    Talimogene laherparepvec injection is used to treat certain melanoma (a type of skin cancer) tumors that cannot ... had radiation treatment in the area of the melanoma tumors, multiple myeloma (cancer of the plasma cells ...