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31.
32.
C Johnson NL Adolphi KL Butler L Debbie M R Larson PD Schwindt ER Flynn 《Journal of magnetism and magnetic materials》2012,324(17):2613-2619
Magnetic relaxometry methods have been shown to be very sensitive in detecting cancer cells and other targeted diseases. Superconducting Quantum Interference Device (SQUID) sensors are one of the primary sensor systems used in this methodology because of their high sensitivity with demonstrated capabilities of detecting fewer than 100,000 magnetically-labeled cancer cells. The emerging technology of atomic magnetometers (AM) represents a new detection method for magnetic relaxometry with high sensitivity and without the requirement for cryogens. We report here on a study of magnetic relaxometry using both AM and SQUID sensors to detect cancer cells that are coated with superparamagnetic nanoparticles through antibody targeting. The AM studies conform closely to SQUID sensor results in the measurement of the magnetic decay characteristics following a magnetization pulse. The AM and SQUID sensor data are well described theoretically for superparamagnetic particles bound to cells and the results can be used to determine the number of cells in a cell culture or tumor. The observed fields and magnetic moments of cancer cells are linear with the number of cells over a very large range. The AM sensor demonstrates very high sensitivity for detecting magnetically labeled cells does not require cryogenic cooling and is relatively inexpensive. 相似文献
33.
Debbie?Leung Laura?Mancinska William?MatthewsEmail author Maris?Ozols Aidan?Roy 《Communications in Mathematical Physics》2012,311(1):97-111
It is known that the number of different classical messages which can be communicated with a single use of a classical channel with zero probability of decoding error can sometimes be increased by using entanglement shared between
sender and receiver. It has been an open question to determine whether entanglement can ever increase the zero-error communication
rates achievable in the limit of many channel uses. In this paper we show, by explicit examples, that entanglement can indeed
increase asymptotic zero-error capacity, even to the extent that it is equal to the normal capacity of the channel. 相似文献
34.
Celeste Garcia Antonio Quesada Manuel Melguizo Justo Cobo Manuel Nogueras Adolfo Snchez Debbie Cannon John Nicolson Low 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1103-1105
The title compound, C9H12N2O3, crystallizes with two molecules in the asymmetric unit. There is extensive hydrogen bonding which results in the formation of a two‐dimensional corrugated sheet. This supramolecular structure is determined by the formation of hydrogen‐bonded chains resulting from the presence of a 6‐amino group and an ethoxycarbonyl group as substituents on a pyridine ring in relative para positions which constitute a π‐electron `push–pull' system. 相似文献
35.
Debbie van der Burg Leila Josefsson Saara Mikkonen Véronique Chotteau Åsa Emmer Hermann Wätzig Cari E. Sänger-van de Griend 《Electrophoresis》2022,43(9-10):922-929
The rapidly growing, competitive biopharmaceutical market requires tight bioprocess monitoring. An integrated, automated platform for the routine online/at-line monitoring of key factors in the cell culture medium could greatly improve process monitoring. Mono- and disaccharides, as the main energy and carbon source, are one of these key factors. A CE-LIF method was developed for the analysis of several mono- and disaccharides, considering requirements and restrictions for analysis in an integrated, automated monitoring platform, such as the possibility for miniaturization to microchip electrophoresis. Analysis was performed after fluorescent derivatization with 8-aminopyrene-1,3,6-trisulfonic acid. The derivatisation reaction and the separation BGE were optimized using design of experiments. The developed method is applicable to the complex matrix of cell culture medium and proved transferable to microchip electrophoresis. 相似文献
36.
L. Van Vaeck J. Bennett P. van Espen E. Schweikert R. Gijbels F. Adams W. Lauwers 《Journal of mass spectrometry : JMS》1989,24(9):797-806
Laser microprobe mass spectrometry (LMMS) has been applied systematically to a variety of organic polyfunctional molecules, covering a wide range of structures and polarities. The microprobe generally offers a combination of desorption under relatively mild conditions with abundant fragmentation. We attempted an empirical approach by tentative hypotheses about desorption and ionization in LMMS to consistently rationalize the detected fragments. The complementary nature of structural data, carried by positive and negative ions, is characteristic for LMMS results of non-ionic compounds. The analysis of salts represents, traditionally, an ultimate test case for soft methods in organic mass spectrometry. Hence, by a selected series of compounds, we have tried to assess to which extent the presence of preformed ions becomes an asset for LMMS analysis and affects the amount, the accessibility or the distribution of organic information between positive and negative fragments. 相似文献
37.
38.
Sterically hindered ligands generally form metal complexes with lower coordination numbers than less hindered ligands. In contrast to dogma, the solid state vanadium(V) complexes with ethylene glycol and pinacol contain four- and five-coordinate vanadium atoms, respectively. Ab initio and electrostatic potential distribution calculations were conducted on both experimental and optimized geometries of the four- and five-coordinate oxovanadium chloroalkoxides. Ab initio energy calculations favor the five-coordinate species for all ligands at all levels of theory examined. No significant differences in the electrostatic properties of the vanadium atoms in the two types of molecules were observed by using electrostatic potential distribution analysis. Methyl group substitutions on the ligand did not change the electronics of the vanadium atoms sufficiently to be a factor. Thus, we conclude that neither electronics nor sterics at the metal center explains the experimental geometries. In the absence of a significant observable electronic effect at the vanadium, we note that the experimental observations can be attributed to ligand geometric effects such as the Thorpe-Ingold and/or gem-dialkyl effects. 相似文献
39.
R. Ben-Av D. Kandel E. Katznelson P. G. Lauwers S. Solomon 《Journal of statistical physics》1990,58(1-2):125-139
We present a stochastic cluster algorithm that drastically reduces critical slowing down forZ
2 lattice gauge theory in three dimensions. The dynamical exponentz is reduced fromz>2 (standard Metropolis algorithm) tozO.73. The Monte Carlo pseudodynamics acts on the gauge-invariant flux tubes that are known to be the relevant large-scale low-energy excitations. A comparison of our results with known results for the 3D Ising model and
4 model supports the conjecture of universality classes for stochastic cluster algorithms. 相似文献
40.
The mass spectral fragmentation of methyl esters of α,β- and β,γ-unsaturated carboxylic acids has been studied. Deuterium labelling, metastable ion analysis and high resolution mass spectrometry have been utilised to elucidate the mechanism of a number of fragmentations and to check possible double bond migration prior to fragmentation. Some breakdown modes were found to occur through double bond migration. Additional support was provided by application of the ‘Metastable Ion Characteristics’ method. Partial isomerisation of molecular ions must therefore be accepted. 相似文献