bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serial killing of tumor cells by cytotoxic T cells redirected with a CD19‐/CD3‐bispecific single‐chain antibody construct
Authors: Hoffmann Patrick , Hofmeister Robert , Brischwein Klaus , Brandl Christian , Crommer Sandrine , Bargou Ralf , Itin Christian , Prang Nadja , Baeuerle Patrick A. 
Published: February 2005

AbstractCertain bispecific antibodies exhibit an extraordinary potency and efficacy for target cell lysis by eliciting a polyclonal T‐cell response. One example is a CD19‐/CD3‐bispecific single‐chain antibody construct (bscCD19xCD3), which at femtomolar concentrations can redirect cytotoxic T cells to eliminate human B lymphocytes, B lymphoma cell lines and patient‐derived malignant B cells. Here we have further explored the basis for this high potency. Using video‐assisted microscopy, bscCD19xCD3 was found to alter the motility and activity of T cells from a scanning to a killing mode. Individual T cells could eliminate multiple target cells within a 9 hr time period, resulting in nuclear fragmentation and membrane blebbing of target cells. Complete target cell elimination was observed within 24 hr at effector‐to‐target cell ratios as low as 1:5. Under optimal conditions, cell killing started within minutes after addition of bscCD19xCD3, suggesting that the rate of serial killing was mostly determined by T‐cell movement and target cell scanning and lysis. At all times, T cells remained highly motile, and no clusters of T and target cells were induced by the bispecific antibody. Bystanding target‐negative cells were not detectably affected. Repeated target cell lysis by bscCD19xCD3‐activated T cells increased the proportion of CD19/CD3 double‐positive T cells, which was most likely a consequence of transfer of CD19 from B to T cells during cytolytic synapse formation. To our knowledge, this is the first study showing that a bispecific antibody can sustain multiple rounds of target cell lysis by T cells. © 2005 Wiley‐Liss, Inc.
Identification and characterisation of the major aspartic proteinase activity in Theobroma cacao seeds
Authors: Guilloteau Martine , Laloi Maryse , Michaux Stephan , Bucheli Peter , McCarthy James 
Published: February 2005

AbstractTheobroma cacao seeds contain an unusually high level of aspartic proteinase activity. Although this activity is central to the development of high‐quality cocoa flavour, the T cacao polypeptide responsible has not yet been definitively identified. Here we report the identification and characterisation of an active protein complex from T cacao seeds with an apparent molecular weight of approximately 50 kDa. This active complex contains at least two polypeptides: an approximately 30.5 kDa aspartic proteinase, the product of the TcAP2 gene, and an associated polypeptide, the 20.5 kDa trypsin inhibitor protein. The active complex co‐eluted off a size exclusion column with another complex containing the trypsin inhibitor and a putative acid chitinase. The 30.5 kDa TcAP2 proteinase is apparently a monomeric aspartic proteinase with optimal activity between 42 and 47 °C and an optimal pH of 3.0. Significant inactivation of the TcAP2 activity occurs at acid pH around 47–52 °C, a temperature potentially obtained during cocoa bean fermentation. SDS‐PAGE analysis showed that the purified TcAP2 complex efficiently degrades the cacao seed storage protein vicilin into peptides smaller than 10 kDa. In addition, high‐resolution size exclusion chromatography showed that this proteinase is capable of degrading proteins into peptides as small as di‐ and tripeptides, indicating for the first time that the main T cacao seed aspartic proteinase can produce very small peptide products. Our results demonstrate that the aspartic proteinase encoded by the TcAP2 gene plays a critical role in the production of cocoa flavour precursor peptides during cocoa bean fermentation. Copyright © 2005 Society of Chemical Industry
Melanosis inhibition and SO2 residual levels in shrimps (Parapenaeus longirostris) after different sulfite‐based treatments
Authors: Gómez‐Guillén M Carmen , Martínez‐Alvarez Óscar , Llamas Argimiro , Montero Pilar 
Published: February 2005

AbstractThe effectiveness of different sulfite‐based treatments to prevent melanosis in fresh deepwater pink shrimp (Parapenaeus longirostris) was evaluated. Increasing the concentration of sulfites, different methods of application (immersion and dust) and synergy with other compounds, such as citric acid and chelants, were investigated. The level of SO2 residues in the muscle was determined in a selection of the most effective treatments. One‐hour dip treatment with 50 g kg−1 sulfite, together with citric acid and chelants, was effective for melanosis prevention for at least one week. With this treatment, the statutory limit of 0.3 g kg−1 SO2 in edible part was not exceeded by the majority of samples analysed. Copyright © 2005 Society of Chemical Industry
Strikingly high content of grain protein in solution‐cultured rice
Authors: Qiuxia He , Qifa Zhou , Xuemei Sun 
Published: February 2005

AbstractA greenhouse experiment was conducted to investigate the nutritional quality of solution‐cultured rice. Five rice cultivars, different in grain amylose content and protein content, were grown under 10, 40 and 80 mg l−1 nitrogen levels during the period of July 2003 to October 2003. In comparison to their original seeds, the solution‐cultured rice Oryza sativa L grain had strikingly higher protein content across all the cultivars and nitrogen levels, and remarkably lower amylose content in the waxy and low amylose cultivars, which might be due to the sufficiently stable nitrogen supply and well‐controlled temperature and humidity. The highest grain protein content was 163.6 g kg−1 in this experiment, which is the highest reported rice grain protein content. The residual nitrogen concentration was greater than 12.39 g kg−1 in the roots, 8.95 g kg−1 in the stems, and 21.97 g kg−1 in the flag leaves across all the cultivars and nitrogen treatments at harvesting. The rice grain had a narrow range of grain carbon content and hydrogen content. The average grain carbon and hydrogen contents for all the rice samples were 42.95 ± 0.15 (n = 60) and 6.81 ± 0.04 g kg−1 (n = 60), respectively. The solution cultured rice grain was characterized with lower carbon–nitrogen mole ratio and lower hydrogen–nitrogen mole ratio, which could be mainly attributed to the increased protein content. The response of plant nitrogen, grain protein and amylose concentration to the supplemental nitrogen level varied with the cultivars. The results in this study suggested that solution culture technology could improve the production potential of rice. Copyright © 2005 Society of Chemical Industry
Instrumental measurement of orange juice colour: a review
Authors: Meléndez‐Martínez Antonio Jesús , Vicario Isabel M. , Heredia Francisco J 
Published: February 2005

AbstractColour of orange juice is provided by carotenoids, which belong to one of the main classes of natural pigments, although the colour of particular orange varieties, blood oranges, is mainly due to anthocyanins. Colour of food influences consumers' preferences. For orange juices, some studies have revealed that the colour of citrus beverages in general is related to the consumer's perception of the quality of these products. The USA attaches great importance to the objective evaluation of orange juice colour, to the point that this attribute is evaluated for the commercial classification of the product on the basis of its quality. Apart from the importance of orange juice colour in relation to the quality of the product, it is important to accurately measure this parameter since it has been demonstrated that colour measurements can be used to estimate the carotenoid content rapidly for quality control purposes. Owing to this factors, several techniques and instruments have been developed over the years. This review assesses these methods and the results gained from them. Copyright © 2005 Society of Chemical Industry
Structure determination and conformation analysis of symmetrical dimers
Authors: Buevich Alexei V. , Chan Tze‐Ming , Wang C. H. , McPhail Andrew T. , Ganguly A. K. 
Published: February 2005

AbstractConformational and stereochemical analysis of six new symmetrical dimers was performed using proton–proton vicinal coupling measured from 1H NMR and 13C satellites of 1H NMR signals, natural abundance 13C‐edited nuclear overhauser effect (NOE) experiments, comprehensive NOE analysis and molecular modeling. The 13C satellite analysis and 13C‐edited NOE experiments were carried out to extract spectral information between equivalent protons. Molecular modeling was applied for estimations of three‐dimensional parameters of the studied dimers, which were subsequently used to generate a set of theoretical NOE for each possible conformation. The J‐coupling, 13C‐edited NOE and quantitative NOE analyses showed the predominance of gauche conformation for three dimers, whereas a mixture of gauche and anti conformations (45:55) for three other dimers was established by quantitative NOE analysis. X‐ray crystallographic study confirmed the stereochemistry of one of the dimers and revealed a discrepancy in conformation stability between liquid and solid states. Copyright © 2004 John Wiley & Sons, Ltd.
1H, 13C and 15N NMR assignments of phenazopyridine derivatives
Authors: Burgueño‐Tapia Eleuterio , Mora‐Pérez Yolanda , Morales‐Ríos Martha S. , Joseph‐Nathan Pedro 
Published: February 2005

AbstractPhenazopyridine hydrochloride (1), a drug in clinical use for many decades, and some derivatives were studied by one‐ and two‐dimensional 1H, 13C and 15N NMR methodology. The assignments, combined with DFT calculations, reveal that the preferred protonation site of the drug is the pyridine ring nitrogen atom. The chemoselective acetylation of phenazopyridine (2) and its influence on the polarization of the azo nitrogen atoms were evidenced by the 15N NMR spectra. Molecular calculations of the phenazopyridines 2–4 show that the pyridine and phenyl groups are oriented in an antiperiplanar conformation with intramolecular hydrogen bonding between the N‐b atom and the C‐2 amino group preserving the E‐azo stereochemistry. Copyright © 2004 John Wiley & Sons, Ltd.
Computational study of the thermal rearrangement of acetoxy(methoxy)carbene
Authors: Czardybon Wojciech , Warkentin John , Werstiuk Nick Henry 
Published: February 2005

AbstractThermolysis of 2‐acetoxy‐2‐methoxy‐5,5‐dimethyl‐Δ3‐1,3,4‐oxadiazoline affords acetoxy(methoxy)carbene. Thermal rearrangement of acetoxy(methoxy)carbene to methyl pyruvate is a concerted 1,2‐migration, avoiding a potential radical‐pair mechanism. Copyright © 2005 John Wiley & Sons, Ltd.
An amino acid has two sides: A new 2D measure provides a different view of solvent exposure
Authors: Hamelryck Thomas 
Published: February 2005

AbstractThe concept of amino acid solvent exposure is crucial for understanding and predicting various aspects of protein structure and function. The traditional measures of solvent exposure however suffer from various shortcomings, like for example the inability to distinguish exposed, partly exposed, buried, and deeply buried residues. This article introduces a new measure of solvent exposure called Half‐Sphere Exposure that addresses many of the shortcomings of other methods. The new measure outperforms other measures with respect to correlation with protein stability, conservation among fold homologs, amino acid‐type dependency and interpretation. The measure consists of the number of Cα atoms in two half spheres around a residue's Cα atom. Conceptually, one of the half spheres corresponds to the side chain's neighborhood, the other half sphere being in the opposite direction. We show here that the two half spheres correspond to two regions around an amino acid that are surprisingly distinct in terms of geometry and energy. This aspect of protein structure introduced here forms the basis of the Half‐Sphere Exposure measure. The results strongly suggest that in many respects, a 2D measure is inherently much better suited to describe solvent exposure than the traditional 1D measures. Importantly, Half‐Sphere Exposure can be calculated from the Cα atom coordinates only, which abolishes the need for a full‐atom model to calculate solvent exposure. Hence, the measure can be used in protein structure prediction methods that are based on various simplified models. Half‐Sphere Exposure has great potential for use in protein structure prediction and analysis. Proteins 2005. © 2005 Wiley‐Liss, Inc.
A theoretical DFT investigation of the lysozyme mechanism: Computational evidence for a covalent intermediate pathway
Authors: Bottoni Andrea , Miscione Gian Pietro , De Vivo Marco 
Published: February 2005

AbstractA theoretical DFT(B3LYP) investigation of the catalytic cycle of lysozyme has provided further evidence for a mechanism involving a glycosil‐enzyme covalent intermediate, in agreement with recent experimental data. This type of intermediate has been located along two different pathways. Along the favored path the retention of the anomeric configuration of the peptidoglycan NAM unit involved in the reaction, is the result of two subsequent inversions at the C1 carbon. The other path involves the opening of the pyranose ring and a nucleophilic attack on the prochiral carbonyl group of the open aldehyde, restoring the original anomeric configuration. No evidence has been found for a pathway characterized by the formation of an oxocarbenium ion (stabilized by resonance and electrostatic interactions), as suggested in the most popular mechanistic schemes. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Continuous wave pump–probe experiment on a planar microcavity
Authors: Sanvitto D. , Whittaker D. M. , Skolnick M. S. , Roberts J. S. 
Published: February 2005

AbstractThe effect of two CW laser beams resonant with the polariton dispersion of a GaAs planar microcavity is discussed. A new coherent polariton emission is observed when the pump and the probe beams are both resonant with the dispersion at finite k‐vectors. This feature is the idler of an optical parametric amplifier (OPA) and is generated by probe‐stimulated scattering of pairs of polaritons from the pump. OPA behaviour is also observed in the optical parametric oscillator (OPO) regime. A study is made of the effect of varying the probe power on the interaction between the pump OPO and the probe OPA states; the OPA idler is found to be a much stronger emission than the signal of the OPO on its own. A simple theoretical model is used to simulate the pump‐probe interactions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of InN with stoichoimetry violation and indium clustering
Authors: Shubina T. V. , Ivanov S. V. , Jmerik V. N. , Glazov M. M. , Kalvarskii A. P. , Tkachman M. G. , Vasson A. , Leymarie J. , Kavokin A. , Amano H. , Akasaki I. , Butcher K. S. A. , Guo Q. , Monemar B. , Kop'ev P. S. 
Published: February 2005

AbstractWe demonstrate that nonstoichiometry is one of the main reason of strong deviation of the InN optical gap in the 0.7–2 eV range, with N/In < 1 and N/In > 1 corresponding to the lower and higher energies, respectively. The phenomenon is discussed in terms of atomic orbital energies, which are strongly different for indium and nitrogen, therefore both excess atom incorporation and elimination could change the optical gap. We estimate such trends using the approximation of the empirical nearest‐neighbor tight binding theory. It is also demonstrated that resonant absorption in In‐enriched regions is an additional factor lowering an effective absorption edge. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Temperature‐dependent polarized luminescence of exciton polaritons in a ZnO film
Authors: Toropov A. A. , Nekrutkina O. V. , Shubina T. V. , Gruber Th. , Kirchner C. , Waag A. , Karlsson K. F. , Monemar B. 
Published: February 2005

AbstractWe report on the studies of linearly polarized photoluminescence (PL) in a (0001) oriented ZnO epitaxial film, grown by metal organic chemical vapor deposition on a GaN template. The emission of mixed longitudinal–transverse exciton polariton modes was observed up to 130 K that evidences polaritonic nature of the excitonic spectrum up to this elevated temperature. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
TDDFT from molecules to solids: The role of long‐range interactions
Authors: Sottile Francesco , Bruneval Fabien , Marinopoulos A. G. , Dash L. K. , Botti Silvana , Olevano Valerio , Vast Nathalie , Rubio Angel , Reining Lucia 
Published: February 2005

AbstractClassical Hartree effects contribute substantially to the success of time‐dependent density functional theory, especially in finite systems. Moreover, exchange‐correlation contributions have an asymptotic Coulomb tail similar to the Hartree term, and turn out to be crucial in describing response properties of solids. In this work, we analyze in detail the role of the long‐range part of the Coulomb potential in the dielectric response of finite and infinite systems, and elucidate its importance in distinguishing between optical and electron energy loss spectra (in the long wavelength limit q → 0). We illustrate numerically and analytically how the imaginary part of the dielectric function and the loss function coincide for finite systems, and how they start to show differences as the distance between objects in an infinite array is decreased (which simulates the formation of a solid). We discuss calculations for the model case of a set of interacting and noninteracting beryllium atoms, as well as for various realistic systems, ranging from molecules to solids, and for complex systems, such as superlattices, nanotubes, nanowires, and nanoclusters. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
From quantum chemistry and the classical theory of polar liquids to continuum approximations in molecular mechanics calculations
Authors: Hassan Sergio A. , Mehler Ernest L. 
Published: February 2005

AbstractBiological macromolecules and other polymers belong to the class of mesoscopic systems, with characteristic length scale of the order of a nanometer. Although microscopic models would be the preferred choice in theoretical calculations, their use in computer simulations becomes prohibitive for large systems or long simulation times. On the other hand, the use of purely macroscopic models in the mesoscopic domain may introduce artifacts, with effects that are difficult to assess and that may compromise the reliability of the calculations. Here is proposed an approach with the aim of minimizing the empirical nature of continuum approximations of solvent effects within the scope of molecular mechanics (MM) approximations in mesoscopic systems. Using quantum chemical methods, the potential generated by the molecular electron density is first decomposed in a multicenter‐multipole expansion around predetermined centers. The monopole and dipole terms of the expansion at each site create electric fields that polarize the surrounding aqueous medium whose dielectric properties can be described by the classical theory of polar liquids. Debye's theory allows a derivation of the dielectric profiles created around isolated point charges and dipoles that can incorporate Onsager reaction field corrections. A superposition of screened Coulomb potentials obtained from this theory makes possible a simple derivation of a formal expression for the total electrostatic energy and the polar component of the solvation energy of the system. A discussion is presented on the physical meaning of the model parameters, their transferability, and their convergence to calculable quantities in the limit of simple systems. The performance of this continuum approximation in computer calculations of amino acids in the context of an atomistic force field is discussed. Applications of a continuum model based on screened Coulomb potentials in multinanosecond simulations of peptides and proteins are briefly reviewed. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Constrained TST MUSIC for joint spatio‐temporal channel parameter estimation in DS/CDMA systems
Authors: Lin Jen‐Der , Fang Wen‐Hsien , Chen Jiunn‐Tsair 
Published: February 2005

AbstractIn this paper, we present a blind and robust algorithm to jointly estimate the directions of arrival (DOAs) and propagation delays in DS/CDMA systems. The rationale of the proposed approach is a hybrid of one‐dimensional (1‐D)multiplesignalclassification (MUSIC) algorithms and constrained spatial/temporal filtering processes. As previously addressed TST MUSIC, two temporal (T)‐MUSIC and one spatial (S)‐MUSIC are employed alternatively in the proposed algorithm to estimate the group delays and the DOAs respectively. However, by utilizing the structure of the data model, no training sequences are required. Furthermore, a constrained temporal filtering process and a constrained spatial beamforming process, which minimize the filtered noise power under a set of judiciously chosen linear constraints, are now employed after the T‐MUSIC and S‐MUSIC respectively. These filtering processes aim to effectively partition the incoming rays and to be robust against the propagation errors in the tree‐structured estimation scheme so that the overall performance can be enhanced. Also, the incoming rays are grouped, isolated and estimated, and the pairing of the estimated delays and DOAs is automatically achieved without extra computational overhead. Furnished simulations show that the new approach can exhibit satisfactory performance with low complexity compared with previous works. Copyright © 2005 John Wiley & Sons, Ltd.
Impact of channel conditions on the throughput optimization in 802.11 DCF
Authors: Wang Xiaodong , Yin Jun , Agrawal Dharma P. 
Published: February 2005

AbstractIn this paper, we evaluate the impact of transmission error rate on the contention and the system throughput in IEEE 802.11 DCF. We identify the trade‐off between the desire to reduce the ratio of overhead in the data packet by adopting larger packet size and the need to reduce the packet error rate by using smaller packet length. Meanwhile, we provide a novel approach to model the different channel conditions incurred by different nodes. This work has applications in performance optimization by establishing trade‐offs between transmission error rate and transmission power, modulation, coding scheme, packet size. Our results substantiate the intuition that in a contention‐based system like 802.11 DCF, the channel variation of any single node in the system not only impacts the throughput of itself, but also affects the throughput of other nodes and the system throughput. Our work shows that to achieve maximum optimization of the throughput, the channel conditions of all the nodes in the system have to be taken into account. Otherwise the optimization is suboptimal. Copyright © 2005 John Wiley & Sons, Ltd.
Brief report: A quality of life instrument for adolescents with growth disorders
Authors: Cramer Joyce A. , Claude Simeoni Marie , Auquier Pascal , Robitail Stéphane , Brasseur Pascale , Beresniak Ariel 
Published: February 2005

AbstractThis study assessed the psychometric properties of a recently developed health‐related quality of life (HRQOL) instrument (Vécu et Santé Perçue de l’Adolescent –Malade, VSP‐AM) in 172 adolescents receiving growth hormone. The VSP‐AM was cross‐culturally adapted into English and tested for internal consistency ( subscales, 0.74 Summary Score), construct and criterion validity, and responsiveness. Correlations with other scales demonstrated convergent validity. Adolescents who reported HRQOL as high or low had significantly different scores (all p<0.001). Adolescents receiving growth hormone therapy differed significantly from adolescents with medical, surgical or psychiatric disorders. The VSP‐AM shows reliability and validity for HRQOL measurement in adolescents with growth disorders.