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11.
D. Bisello G. Busetto A. Castro M. Nigro M. Penzo L. Pescara M. Posocco P. Sartori L. Stanco Z. Ajaltouni A. Falvard J. Jousset B. Michel J. C. Montret A. Antonelli R. Baldini A. Calcaterra G. Capon M. Schioppa J. -E. Augustin G. Cosme F. Couchot B. Dudelzak F. Fulda G. Grosdidier B. Jean-Marie S. Jullian D. Lalanne V. Lepeltier F. Manè C. Paulot R. Riskalla Ph. Roy G. Szklarz DM Collaboration 《Zeitschrift fur Physik C Particles and Fields》1988,39(1):13-19
Thee + e ?→K + K ? cross section has been measured from about 750 events in the energy interval \(1350 \leqq \sqrt s \leqq 2400 MeV\) with the DM2 detector at DCI. TheK ± form factor |F F ±| cannot be explained by the ρ, ω, ? and ρ′(1600). An additional resonant amplitude at 1650 MeV has to be added as suggested by a previous experiment. 相似文献
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H.W. Atherton C. Bovet P. Coet R. Desalvo N. Doble R. Maleyran E.W. Anderson G. Von Dardel K. Kulka M. Boratav J.W. Cronin B.D. Milliken 《Physics letters. [Part B]》1985,158(1):81-84
The lifetime of the neutral pion (π0) has been directly measured. The lifetime has been found to be τπ0 = (0.897±0.022±0.017) × 10?16 s. The systematic error results from uncertainties in the momentum spectrum of the π0 used for the measurement. This measurement yields a decay width of the π0 of (7.34±0.18±0.11) eV. An axial anomaly calculation, which neglects the finite mass of the π0, predicts a value of 7.87 eV. 相似文献
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The steady propagation of a thin smouldering front in a half-spacehas been considered. A suitable coordinate transformation hasallowed the region near the leading edge of the front to beexamined for both a maintained planar surface and with surfacecollapse due to material shrinkage. The change in the oxidizerconcentration for a small increment in the propagation speedfor large time and surface collapse has been determined. Theinfluence of two types of nonlinear diffusion on the shape ofthe smouldering front has been found; other cases can be dealtwith in a similar manner. 相似文献
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Bence Paul Kai Kysenius James B. Hilton Michael W. M. Jones Robert W. Hutchinson Daniel D. Buchanan Christophe Rosty Fred Fryer Ashley I. Bush Janet M. Hergt Jon D. Woodhead David P. Bishop Philip A. Doble Michelle M. Hill Peter J. Crouch Dominic J. Hare 《Chemical science》2021,12(30):10321
Tumours are abnormal growths of cells that reproduce by redirecting essential nutrients and resources from surrounding tissue. Changes to cell metabolism that trigger the growth of tumours are reflected in subtle differences between the chemical composition of healthy and malignant cells. We used LA-ICP-MS imaging to investigate whether these chemical differences can be used to spatially identify tumours and support detection of primary colorectal tumours in anatomical pathology. First, we generated quantitative LA-ICP-MS images of three colorectal surgical resections with case-matched normal intestinal wall tissue and used this data in a Monte Carlo optimisation experiment to develop an algorithm that can classify pixels as tumour positive or negative. Blinded testing and interrogation of LA-ICP-MS images with micrographs of haematoxylin and eosin stained and Ki67 immunolabelled sections revealed Monte Carlo optimisation accurately identified primary tumour cells, as well as returning false positive pixels in areas of high cell proliferation. We analysed an additional 11 surgical resections of primary colorectal tumours and re-developed our image processing method to include a random forest regression machine learning model to correctly identify heterogenous tumours and exclude false positive pixels in images of non-malignant tissue. Our final model used over 1.6 billion calculations to correctly discern healthy cells from various types and stages of invasive colorectal tumours. The imaging mass spectrometry and data analysis methods described, developed in partnership with clinical cancer researchers, have the potential to further support cancer detection as part of a comprehensive digital pathology approach to cancer care through validation of a new chemical biomarker of tumour cells.Digital pathology and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imaging reveals a unique elemental signature of colorectal cancer. 相似文献
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This review provides analysts with critical insights of current approaches for quantification by laser ablation-inductively coupled plasma-mass spectrometry in the field of elemental imaging. This encompasses both calibration strategies that have been used with success in imaging biological samples, as well as those with potential to improve analytical accuracy and precision if applied to imaging. Methods reviewed include the use of CRMs, laboratory prepared matrix matched standards, internal standardisation, online standard addition and a variety of novel approaches that makes elemental imaging accessible to a wider base of analysts. The importance of quantification and factors affecting its use in imaging will also be considered. 相似文献
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G. D. Barr P. Buchholz D. Cundy N. Doble L. Gatignon P. Grafström R. Hagelberg H. Wahl K. J. Peach T. Beier H. Blümer D. Coward R. Heinz K. Kleinknecht F. Leber P. Mayer B. Renk H. Rohrer H. G. Sander J. Scheidt J. Staeck A. Wagner E. Augé D. Fournier L. Iconomidou-Fayard O. Perdereau A. C. Schaffer L. Serin L. Bertanza P. Calafiura M. Calvetti R. Carosi R. Casali C. Cerri I. Mannelli V. M. Marzulli A. Nappi G. M. Pierazzini M. Holder A. Kreutz M. Rost R. Werthenbach 《Zeitschrift fur Physik C Particles and Fields》1995,65(3):361-365
Data from the NA31 experiment at CERN have been used to measure the branching ratio of the double Dalitz decay of the long-lived neutral kaon. Eight events have been found with negligible background. The measured distribution of the angle between the planes of the two e+e?-pairs favours aCP=?1 state for the long-lived neutral kaon. 相似文献
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Esseiva P Anglada F Dujourdy L Taroni F Margot P Pasquier ED Dawson M Roux C Doble P 《Talanta》2005,67(2):360-367
Artificial neural networks (ANNs) were utilised to validate illicit drug classification in the profiling method used at “Institut de Police Scientifique” of the University of Lausanne (IPS). This method established links between samples using a combination of principal component analysis (PCA) and calculation of a correlation value between samples.Heroin seizures sent to the IPS laboratory were analysed using gas chromatography (GC) to separate the major alkaloids present in illicit heroin. Statistical analysis was then performed on 3371 samples. Initially, PCA was performed as a preliminary screen to identify samples of a similar chemical profile. A correlation value was then calculated for each sample previously identified with PCA. This correlation value was used to determine links between drug samples. These links were then recorded in an Ibase® database. From this database the notion of “chemical class” arises, where samples with similar chemical profiles are grouped together. Currently, about 20 “chemical classes” have been identified.The normalised peak areas of six target compounds were then used to train an ANN to classify each sample into its appropriate class. Four hundred and sixty-eight samples were used as a training data set. Sixty samples were treated as blinds and 370 as non-linked samples. The results show that in 96% of cases the neural network attributed the seizure to the right “chemical class”.The application of a neural network was found to be a useful tool to validate the classification of new drug seizures in existing chemical classes. This tool should be increasingly used in such situations involving profile comparisons and classifications. 相似文献
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Doble DM Melchior M O'Sullivan B Siering C Xu J Pierre VC Raymond KN 《Inorganic chemistry》2003,42(16):4930-4937
The thermodynamic stabilities of the Gd(III) complexes of five hexadentate ligands, which incorporate the 2,3-dihydroxyterephthalamide and 2,3-hydroxypyridonate chelating moieties, have been determined by potentiometric and spectrophotometric titration. The ligands were chosen to span a range of basicities while maintaining a similar tripodal structural motif, facilitating a study of the effect of ligand basicity on the thermodynamic stability of the Gd(III) complexes. The relative stability of the five complexes is found to be highly pH dependent, with the most acidic ligands forming the most stable complexes at low pH and more basic ligands forming more stable complexes at high pH. The most stable Gd(III) complex at a physiological pH of 7.4 is formed with a ligand of intermediate basicity and is of stability comparable to that of Gd(III) complexes that feature eight-coordinate amino-carboxylate ligands and are currently used as magnetic resonance imaging contrast agents in diagnostic medicine. A single-crystal X-ray structure of the intermediate compound 3-hydroxy-6-methyl-2-oxo-1,2-dihydropyridine-4-carboxylic acid ethyl ester is described: This compound crystallizes in the triclinic space group P1 with a = 7.4801(3) A, b = 8.0671(3) A, c = 8.3457(4) A, alpha = 72.242(2) degrees, beta = 80.693(2) degrees, gamma = 69.943(3) degrees, V = 449.60(3) A(3), Z = 2, and R = 0.042. 相似文献
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