bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of (R)‐ and (S)‐phenprocoumon in human plasma by enantioselective liquid chromatography/electrospray ionisation tandem mass spectrometry
Authors: Kammerer Bernd , Kahlich Rainer , Ufer Mike , Laufer Stefan , Gleiter Christoph H. 
Published: February 2004

AbstractPhenprocoumon is a commonly used oral anticoagulant of the coumarin type, and has found extensive clinical use in the treatment of thrombophlebitis, pulmonary embolism and atrial fibrillation. In the course of a clinical study to investigate the influence of genetic polymorphisms of the CYP2C9 enzyme on phenprocoumon metabolism, we developed a new enantioselective liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/MS/MS) method to quantify (R)‐ and (S)‐phenprocoumon in human plasma. HPLC separation of the enantiomers was achieved on a Chira‐Grom‐2 column under isocratic conditions using a water/acetonitrile/formic acid eluent. For detection and quantification a triple‐quadrupole MS system was used in the selected reaction monitoring (SRM) mode. As an internal standard the structurally homologous compound warfarin was chosen. The detector response was linear with a correlation coefficient of 0.988–0.999 for (R)‐phenprocoumon and 0.989–0.999 for (S)‐phenprocoumon in the investigated concentration range between 62.5 and 1000 ng/mL (per enantiomer). The limit of detection (LOD) was 12.5 ng/mL. Copyright © 2004 John Wiley & Sons, Ltd.
Sensitivity improvement of amino acids by N‐terminal diisopropyloxyphosphorylation in electrospray ionization mass spectrometry
Authors: Chen Yi , Zhang Jianchen , Chen Jing , Cao Xiao‐Yu , Wang Jin , Zhao Yu‐Fen 
Published: February 2004

AbstractWith the introduction of a diisopropyloxyphosphoryl (DIPP) group at the N‐terminus of amino acids, the signal response in electrospray ionization mass spectrometry can be enhanced by 10–100‐fold in positive mode and even more in negative mode. An enhancement of proton affinity due to the N‐terminal DIPP derivatization was considered to be responsible for the sensitivity improvement in positive mode, which was supported by kinetic method studies. Two possible mechanisms, i.e., an increase in gas‐phase acidity due to the introduction of the electron‐withdrawing DIPP group, and the effect of pH on the formation of anions of amino acids and their phosphorylated derivatives, were considered for the signal response enhancement in negative mode. Copyright © 2004 John Wiley & Sons, Ltd.
Surface field activated fragmentation of arginine oligomers
Authors: Jungclas H. , Schmidt L. , Komarov V. V. , Popova A. M. , Stureiko I. O. 
Published: February 2004

AbstractProtonated arginine oligomers produced by matrix‐assisted laser desorption/ionization (MALDI) graze at a kinetic energy of 350 eV along a surface of fluorinated hydrocarbon or mineral oil. The cation fragments activated by excitation processes during the slide on the surface are analyzed by time‐of‐flight mass spectrometry. The resulting fragment ion mass spectra are interpreted by applying a theoretical concept of excimol accumulation and trap bond dissociation, suggested earlier. According to this theory, energy is accumulated and fragments are formed independently by each arginine residue of a sliding oligomer ion. It is concluded that the observed variation in the fragment ion spectra of the oligomers is a consequence of different oligomer velocities and not a fingerprint of different ion structures. Copyright © 2004 John Wiley & Sons, Ltd.
Product identification and adenylyl cyclase activity in chloroplasts of Nicotiana tabacum
Authors: Witters Erwin , Quanten Lieve , Bloemen Jo , Valcke Roland , Onckelen Harry Van 
Published: February 2004

AbstractIn view of the ongoing debate on plant cyclic nucleotide metabolism, especially the functional presence of adenylyl cyclase, a novel detection method has been worked out to quantify the reaction product. Using uniformly labelled 15N‐ATP as a substrate for adenylyl cyclase, a qualitative and quantitative liquid chromatography/electrospray ionisation tandem mass spectrometry (LC/ESI‐MS/MS) method was developed to measure de novo formed 15N‐adenosine 3′,5′‐cyclic monophosphate. Adenylyl cyclase activity was observed in chloroplasts obtained from Nicotiana tabacum cv. Petit Havana and the kinetic parameters and influence of various metabolic effectors are discussed in their context. Copyright © 2004 John Wiley & Sons, Ltd.
Maturation of astrocyte morphology and the establishment of astrocyte domains during postnatal hippocampal development
Authors: Bushong Eric A. , Martone Maryann E. , Ellisman Mark H. 
Published: February 2004

AbstractMature protoplasmic astrocytes exhibit an extremely dense ramification of fine processes, yielding a ‘spongiform’ morphology. This complex morphology enables protoplasmic astrocytes to maintain intimate relationships with many elements of the brain parenchyma, most notably synapses. Recently, it has been demonstrated that astrocytes establish individual cellular‐level domains within the neuropil, with limited overlap occurring between the extents of neighboring astrocytes. The highly ramified nature of protoplasmic astrocytes is closely associated with their ability to create such domains. This study was an attempt to characterize the development of spongiform processes and the establishment of astrocyte domains. A combination of immunolabeling for the astrocyte‐specific markers glial fibrillary acidic protein and S100β with intracellular dye labeling in fixed tissue slices allowed for the identification of immature astrocytes and the elucidation of their complete, well‐preserved morphologies. We find that during the first two postnatal weeks astrocytes extend stringy, filopodial processes. Fine, spongiform processes appear during the third week. Protoplasmic astrocytes are quite heterogeneous in morphology at 1‐week postnatum, but there is a remarkable consistency in morphology by 2 weeks of age. Finally, protoplasmic astrocytes initially extend long, overlapping processes during the first two postnatal weeks. The subsequent elaboration of spongiform processes results in the development of boundaries between neighboring astrocyte domains. Stray processes that encroach on neighboring domains are eventually pruned by 1 month of age. These observations suggest that domain formation is largely the consequence of competition between astrocyte processes, similar to the well‐studied competitive interactions between certain neuronal dendritic fields.
The role of cutaneous sensation in the motor function of the hand
Authors: Ebied Ayman M. , Kemp Graham J. , Frostick Simon P. 
Published: February 2004

AbstractWe studied the effect of abolishing cutaneous sensation (by infiltrating local anaesthetic around the median nerve at the wrist) on the ability of 10 healthy volunteers (a) to maintain a submaximal isometric pinch‐grip force for 30 s without visual feedback, and (b) to perform a fine finger‐manipulation „handwriting”︁ task. Blocking cutaneous sensation had no effect on ability to maintain pinch force, suggesting that muscle afferents have the major role in force‐control feedback. However, a near‐linear fall in force, present with or without block (mean slope = −1.3 ± 0.2% s−1), which cannot be attributed to motor fatigue, reveals a shortcoming of the afferent feedback system. Blocking cutaneous sensation did impair ability to perform the more demanding writing task, as judged by an 18 ± 6% increase in the length of the path between target points, a 22 ± 9% increase in the duration of the movement and a 63 ± 24% in „normalised averaged rectified jerk”︁, an averaged time‐derivative of acceleration (all significantly nonzero, P < 0.04). These experiments demonstrate the relative importance of muscular and cutaneous afferent feedback on two aspects of hand performance, and provide a way to quantify the deficit resulting from the lack of cutaneous sensation. © 2003 Published by Elsevier Ltd. on behalf of Orthopaedic Research Society. All rights reserved.
Assessment of healing of grade III posterolateral corner injuries: An in vivo model
Authors: LaPrade Robert F. , Wentorf Fred A. , Crum Joshua A. 
Published: February 2004

AbstractThe primary purpose of this study was to test the hypothesis that an in vivo model of posterolateral knee instability could be created in the rabbit and to develop a natural history model in animals.The biomechanical and gross features of the rabbit knee 12 weeks after rupture of the fibular collateral ligament (FCL) and popliteus tendon were investigated in 14 skeletally mature New Zealand white rabbits. In the operated leg both the FCL and popliteus tendon were traumatically ruptured near their respective femoral insertions and the contralateral leg served as the control. At 12 weeks, the legs were removed for analysis of healing by both gross analysis and by biomechanical testing of knee joint stability. Biomechanical testing of varus–valgus knee rotation as well as concurrent coupled external rotation was performed to measure the amount of force necessary to produce a uniform amount of displacement.Grossly, only one of the FCLs and none of the popliteus tendons healed. Biomechanical testing revealed a statistically significant difference in the amount of force necessary to achieve 10 mm displacement for the operative versus the contralateral control knee for varus at 30° (p < 0.001), 60° (p < 0.006), and 90° (p < 0.01).Our data supports the clinical observations of human grade III posterolateral corner (PLC) injuries, which appear to undergo minimal healing and generally result in poor outcomes with conservative treatment, that the FCL or popliteus tendon rarely heal when torn. This initial study of healing and knee stability after PLC injuries in rabbits supports the further study of in vivo animal models for evaluation of posterolateral knee injuries. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Effects of juvenile hormone I, precocene I and precocene II on the progeny of Microplitis rufiventris Kok. female when administered via its host, Spodoptera littoralis (Boisd.)
Authors: Khafagi W. E. 
Published: February 2004

Abstract:Reproductive biologies of Microplitis rufiventris Kok. females resulting from topically treated Spodoptera littoralis (Boisd.) larvae with constant effective doses of juvenile hormone I (JHI, 1 μg), precocene I (PI, 25 μg) or PII (25 μg) were investigated. Although the female wasps were treated during their presence as eggs or larvae in their hosts, the complete effects of the test compound were not apparent until the wasps had become adults. On the bases of the obtained results, the reproductive inhibition activity caused by the test compounds comprises of two categories: (1) reduction in progeny production, and (2) induction of significant proportion of imperfect ‘non‐functional’ parasitoid progeny. Whereas, the adverse effect of JHI is only restricted to the second category, the adverse effects of PI or PII fall into both categories. Thus, workers should be aware of the delayed effects of new generations of pesticides which may occur in later stages of the non‐target insects.
Ovipositional discrimination by Microplitis rufiventris females between healthy and granulosis virus‐infected Spodoptera littoralis larvae
Authors: Hegazi E. M. , Abo Abd‐Allah L. M. Z. 
Published: February 2004

Abstract:Ovipositional choice tests by Microplitis rufiventris females (Hym., Braconidae) between granulosis virus‐infected (GVI) and non‐infected (NI) Spodoptera littoralis larvae (Lep., Noctuidae), were assessed using discriminatory methods for re‐isolating the NI and virus‐infected hosts after removing the female parasitoid. When M. rufiventris females were given a choice between NI and GVI S. littoralis hosts, the adult females exhibited marked preference (P < 0.01) for the NI (i.e. higher quality) hosts. In this case, M. rufiventris females and S. littoralis GV (SlGV) did not significantly compete for the same type of host larvae and are, generally, compatible. However, when the choice was given between two low qualities of S. littoralis hosts, i.e. virus‐free previously parasitized hosts and viral‐infected hosts a significant preference (P < 0.01) of the parasitoid females for the GVI larvae was observed. In this case, the parasitoid would be at a disadvantage when competing with GV for the same host. However, the parasitoid could be used as an additional tool for the dissemination of biocontrol viruses within different pest populations, i.e. hosts other than S. littoralis. Importantly, the results showed different strategies of parasitoid female in egg‐laying management. When M. rufiventris female was given a choice between healthy and SlGVI hosts, the female deposited more eggs than when she was given a choice between two low qualities of host larvae. The results of the study may have implications in pest management strategies using M. rufiventris and SlGV against S. littoralis larvae.
Population dynamics of Monochamus carolinensis (Col., Cerambycidae) under laboratory conditions
Authors: Akbulut S. , Stamps W. T. , Linit M. J. 
Published: February 2004

Abstract:The study of life history dynamics of the pine sawyer beetle Monochamus carolinensis (Olivier) is of interest because the beetles are vectors for the pinewood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle, the causal agent of pine wilt in susceptible pine trees. Previous observation of a laboratory colony of M. carolinensis suggested numbers of adult beetles reared from logs varied little in relation to oviposition densities among individual logs. Logs in laboratory colonies are routinely subjected to artificially high oviposition rates. The objectives of this study were to examine the relationship between initial oviposition rate, holding time (time between log cut and oviposition), log volume and area and adult survivorship in laboratory colony. This study examined the number of eggs, larvae, adults and generation survivorship in logs over a 2‐year period. The number of adults emerged per log was not related to the number of eggs laid. Late larval and adult numbers were significantly correlated with log size. Only 12% of the initial cohort completed development and emerged as adults. We attribute the high within‐log mortality of beetles to intraspecific competition and cannibalism.
A kaolin‐based particle film for suppression of the olive fruit fly Bactrocera oleae Gmelin (Dip., Tephritidae) in olive groves
Authors: Saour G. , Makee H. 
Published: February 2004

Abstract:The efficacy of a kaolin‐based particle film formulation M‐99‐099 to control olive fruit fly, Bactrocera oleae Gmelin, field infestations was investigated in north‐western Syria. The results showed that fruit infestation levels were significantly reduced on kaolin‐treated trees compared with untreated trees. Kaolin particle film successfully suppressed B. oleae populations and provided season‐long insect control (>14 weeks) whereas the insecticide dimethoate failed to protect olives for as long a period after the last spray. Consistent with previous findings, the M‐99‐099 kaolin particle film proved to be a promising alternative method to synthetic insecticides and could be used to control B. oleae in olive groves.
Inverse Functions of the Products of Two Bessel Functions and Applications to Potential Scattering
Authors: Mavromatis H. A. , Schilcher K. 
Published: February 2004

Inverse functions of products of two Bessel functions jl(xy)jm(xy) are determined for the cases m = l, l + 1, and l + 2. Integral representations for these inverse functions in terms of Neumann functions are given, and some of the simplest ones are expressed in terms of trigonometric functions.
We show how one may obtain an integral representation for any well-behaved function in terms of products of two Bessel functions, with the help of these inverse functions and also outline some of their applications to potential scattering. In particular, we demonstrate the usefulness of the inverse functions in determining the potential explicitly from the phase shifts in the Born approximation.
Almost Symmetric Spaces and Gravitational Radiation
Authors: Matzner Richard A. 
Published: February 2004

A generalization of the idea of Killing fields to spaces which are not symmetric is given. The field so defined specifies coordinate lines along which the variation of the metric tensor is the slowest possible in a global sense. Thus it generalizes the Killing fields in spaces with a symmetry where the metric tensor does not change along Killing trajectories. Several examples are given, and the method is then applied to spaces containing gravitational radiation of the type considered by Issacson.
For spaces containing radiation, it is shown that a real functional λ[ξ], associated with every vector field ξ, measures some parameters associated with the radiation. In the simplest case this parameter is the ``energy density'' of the radiation, but, if a sufficient number of vector fields can be invariantly defined in the background, the average gravitational ``stress'' associated with the wave may also be measured. We conclude with some conjectures about further application of these ideas to the theory of gravitational radiation.
Diffuse Transmission of Light from a Central Source through an Inhomogeneous Spherical Shell with Isotropic Scattering
Authors: Bellman R. E. , Kagiwada H. H. , Kalaba R. E. , Ueno S. 
Published: February 2004

A partial-differential-integral equation is derived in this paper for the angular distribution of the radiation which is diffusely transmitted through an inhomogeneous, isotropically scattering, spherical shell when there is a constant net flux of radiation normally incident on the inner surface. An equation is also derived for the strength of the diffusely reflected radiation when the shell is illuminated at each point on the outer surface by constant isotropic incident radiation.
The equations obtained appear to lend themselves well to numerical solution. Astrophysically, the situation corresponds to determining the brightness of a spherical planetary nebula. As far as is known, the equations are new and exact.
On dynamical groups: Classification of Lie algebras with Galilei subalgebras
Authors: Doebner H. D. , Hennig J. 
Published: February 2004

Because of the pure group theoretical approach to the free nonrelativistic particle through an integrable irreducible representation of the quantum mechanical Galilei (Lie) algebra G, it is reasonable to construct so-called dynamical (Lie) algebras D which possess an integrable representation describing interacting (nonrelativistic) systems. Such dynamical algebras D should contain the geometrical subalgebra G0 of G, spanned by the mass operator, the momentum, the angular-momentum and the position operators. Furthermore, the relation between the free and the interacting system is simplified if the one-dimensional Lie algebra T generating free time translations is a subalgebra of D. Hence preferred candidates for D are those Lie algebras L which possess a subalgebra isomorphic to G or to G0, i.e., those L for which an injective homomorphism ε:G→ε(G)⊂L or G0→ε(G0)⊂L exists. ε is called an embedding of G or of G0 in L. Our main result is a complete classification of (i) all nonsemisimple L with Levi decomposition L=S[addition in left half circle]F with G or G0 embedding ε such that S⊂ε(G) or S⊂ε(G0) (ii) all complex semisimple L̄ with an embedding of the complex extension of G, (iii) all real simple L being real forms or realifications of the lowest dimensional L̄ (i.e., A5, B3, C4) with G-embedding.
The result gives a fairly complete list of all candidates for dynamical nonrelativistic algebras. The physical aspects of two of them, the conformal Galilei algebra Gc and a limitable dynamical algebra Dt, are discussed. A method for the construction of physically useful integrable representations for Gc and Dt is given. Some general properties of nonrelativistic and of relativistic dynamical algebras with G-embeddings are considered.
Diet, nutrition and the prevention of type 2 diabetes
Authors: Steyn NP , Mann J , Bennett PH , Temple N , Zimmet P , Tuomilehto J , Lindström J , Louheranta A 
Published: February 2004

AbstractObjectives:The overall objective of this study was to evaluate and provide evidence and recommendations on current published literature about diet and lifestyle in the prevention of type 2 diabetes.Design:Epidemiological and experimental studies, focusing on nutritional intervention in the prevention of type 2 diabetes are used to make disease-specific recommendations. Long-term cohort studies are given the most weight as to strength of evidence available.Setting and subjects:Numerous clinical trials and cohort studies in low, middle and high income countries are evaluated regarding recommendations for dietary prevention of type 2 diabetes. These include, among others, the Finnish Diabetes Prevention Study, US Diabetes Prevention Program, Da Qing Study; Pima Indian Study; Iowa Women's Health Study; and the study of the US Male Physicians.Results:There is convincing evidence for a decreased risk of diabetes in adults who are physically active and maintain a normal body mass index (BMI) throughout adulthood, and in overweight adults with impaired glucose tolerance who lose weight voluntarily. An increased risk for developing type 2 diabetes is associated with overweight and obesity; abdominal obesity; physical inactivity; and maternal diabetes. It is probable that a high intake of saturated fats and intrauterine growth retardation also contribute to an increased risk, while non-starch polysaccharides are likely to be associated with a decreased risk. From existing evidence it is also possible that omega-3 fatty acids, low glycaemic index foods and exclusive breastfeeding may play a protective role, and that total fat intake andtransfatty acids may contribute to the risk. However, insufficient evidence is currently available to provide convincing proof.Conclusions:Based on the strength of available evidence regarding diet and lifestyle in the prevention of type 2 diabetes, it is recommended that a normal weight status in the lower BMI range (BMI 21–23) and regular physical activity be maintained throughout adulthood; abdominal obesity be prevented; and saturated fat intake be less than 7% of the total energy intake.