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61.
Hyyryläinen AR Pakarinen JM Vainiotalo P Stájer G Fülöp F 《Journal of the American Society for Mass Spectrometry》2007,18(6):1038-1045
Host-guest complexes where tetraethyl resorcarene was the host molecule were used to study the stereoselectivity of diasteromeric pairs of di-endo- and di-exo-2,3-disubstituted norbornane and norbornene amino acids by ion-molecule reactions and collision-induced dissociation with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Both methods showed stereoselectivity for the diastereomeric pairs. Particularly high selectivity was achieved for di-endo- and di-exo-2,3-disubstituted norbornane amino acids with ion-molecule reactions. Also, ab initio and hybrid density functional theory calculations were performed to study the different structures of the host-guest complexes. Hydrogen bonding was crucial for the calculated lowest energy structures, and sterical considerations satisfactorily explained the ion-molecule reaction results. 相似文献
62.
Rust T. Tlegenov Jaana M. H. Pakarinen Larisa Oresmaa Markku Ahlgrén Pirjo Vainiotalo 《Journal of heterocyclic chemistry》2007,44(6):1339-1344
Some ester, amide and thioether derivatives of lupinine, aminolupinine and bromolupinine were synthesized and characterized in order to search biologically active compounds. The protonated molecules were studied by tandem mass spectrometry using collision induced dissociation (CID) technique in order to find out how different structural features and functional groups in different quinolizidine derivatives influence fragmentation behavior. Some theoretical calculations were also made to clarify the conformations of neutral and protonated molecules, to reveal the fragmentation routes and the product ions obtained. The functional groups clearly directed the fragmentations although the typical fragments for lupinine were still observed in all the cases. Theoretical calculations were in agreement with observed fragmentations and greatly helped interpretation of the CID spectra. 相似文献
63.
Nikky Kortbeek Aleida Braaksma Ferry HF Smeenk Piet JM Bakker Richard J Boucherie 《The Journal of the Operational Research Society》2015,66(7):1061-1076
The design and operations of inpatient care facilities are typically largely historically shaped. A better match with the changing environment is often possible, and even inevitable due to the pressure on hospital budgets. Effectively organizing inpatient care requires simultaneous consideration of several interrelated planning issues. Also, coordination with upstream departments like the operating theatre and the emergency department is much-needed. We present a generic analytical approach to predict bed census on nursing wards by hour, as a function of the Master Surgical Schedule and arrival patterns of emergency patients. Along these predictions, insight is gained on the impact of strategic (ie, case mix, care unit size, care unit partitioning), tactical (ie, allocation of operating room time, misplacement rules), and operational decisions (ie, time of admission/discharge). The method is used in the Academic Medical Center Amsterdam as a decision-support tool in a complete redesign of the inpatient care operations. 相似文献
64.
A. -P. Leppänen J. Uusitalo P. T. Greenlees R. -D. Herzberg N. Amzal F. Becker P. A. Butler A. J. C. Chewter J. F. C. Cocks O. Dorvaux S. Eeckhaudt K. Eskola J. Gerl T. Grahn N. J. Hammond K. Hauschild K. Helariutta F. P. Heßberger M. Houry G. D. Jones P. M. Jones R. Julin S. Juutinen H. Kankaanpää H. Kettunen T. L. Khoo W. Korten P. Kuusiniemi Y. Le Coz M. Leino C. J. Lister R. Lucas M. Muikku P. Nieminen M. Nyman R. D. Page J. Pakarinen P. Rahkila P. Reiter J. Sarén Ch. Schlegel C. Scholey O. Stezowski Ch. Theisen W. H. Trzaska H. J. Wollersheim 《The European Physical Journal A - Hadrons and Nuclei》2006,28(3):301-306
An in-beam study of the transfermium nucleus 252No has been performed using the JUROSPHERE II array of germanium detectors coupled to the gas-filled recoil separator RITU.
A new technique of recoil-fission tagging was used to extract tagged γ-ray data. Having significant spontaneous fission and
α-decay branches, 252No is an ideal candidate for a comparative study. In a similar manner to α-decay tagging the fission events can be used to
obtain γ-ray data. The recoil-fission tagged γ-ray spectrum showed a similar structure to the α-decay tagged γ-ray spectrum.
By comparing the α-tagged and fission-tagged spectra and decay curves, it was shown that the spontaneous fission originates
from the same initial state as the α decay. This extension of the tagging method allows in-beam spectroscopic data to be obtained
from heavy nuclei with significant spontaneous-fission branches. 相似文献
65.
66.
B. S. Nara Singh A. N. Steer D. G. Jenkins R. Wadsworth P. J. Davies R. Glover N. S. Pattabiraman T. Grahn P. T. Greenlees P. Jones R. Julin M. Leino M. Nyman J. Pakarinen P. Rahkila C. Scholey J. Sorri J. Uusitalo P. A. Butler M. Dimmock D. T. Joss J. Thomson C. J. Lister B. Cederwall B. Hadinia M. Sandzelius 《The European physical journal. Special topics》2007,150(1):147-148
We present a study of low-spin states in 74Rb and 78Y
using the new technique of Recoil Beta Tagging.
This yielded new information on 74Rb and has provided the first evidence
for non-isomeric T= 1 states in 78Y. 相似文献
67.
68.
69.
Hyyryläinen AR Pakarinen JM Fülöp F Vainiotalo P 《Journal of the American Society for Mass Spectrometry》2009,20(1):34-41
Stereochemical differentiation of five diastereomeric pairs of β-amino acids, di-endo- and di-exo-2,3-disubstituted norbornane and norbornene amino acids, cis- and trans-2-aminocyclohexane-, 2-amino-4-cyclohexene-, and 2-aminocyclopentanecarboxylic acids, was investigated via the kinetic method
with metal-bound trimeric complexes. This is the first time that diastereomers (di-endo/di-exo and cis/trans) have been differentiated with metal-bound trimeric complexes and the kinetic method. Moreover, determination of diastereochemical
excess by the kinetic method was applied to norbornane β-amino acids and cyclopentane β-amino acids. Experiments showed that a remarkable differentiation of the studied diastereomers was achieved. It was observed
that better selectivity values correlated to more rigid structures. The reference compounds for the studied β-amino acids varied from α-amino acids to some β-amino acids. In addition, variation of the metal ion (Cu2+ and Ni2+) had some role in the selectivity values obtained. Ab initio and hybrid density functional theory calculations were performed
to clarify the results obtained by mass spectrometry. 相似文献
70.
Anna R. M. Hyyryläinen Jaana M. H. Pakarinen Enikő Forró Ferenc Fülöp Pirjo Vainiotalo 《Journal of the American Society for Mass Spectrometry》2009,20(7):1235-1241
Chiral differentiation of four enantiomeric pairs of β-amino acids, cis-(1R,2S)-, cis-(1S,2R)-, trans-(1R,2R)-, and trans-(1S,2S)-2-aminocyclopentanecarboxylic acids (cyclopentane β-amino acids), and cis-(1R,2S)-, cis-(1S,2R)-, trans-(1R,2R)-, and trans-(1S,2S)-2-aminocyclohexanecarboxylic acids (cyclohexane β-amino acids) was performed successfully by using host-guest complexes and ion/molecule reactions. The experiments were conducted
by using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. The effect of a chiral host
molecule was tested by using three different host compounds; (+)-(18-Crown-6)-2,3,11,12-tetracarboxylic acid, (−)-(18-Crown-6)-2,3,11,12-tetracarboxylic
acid, and β-cyclodextrin. This is the first time that small enantiomeric pairs with two chiral centers have been differentiated using
ion/molecule reactions and host-guest complexes. 相似文献