bluuebunny/crossref_metadata_2025_split huggingface dataset:
Health‐related quality of life in sickle cell disease
Authors: Panepinto Julie A. 
Published: March 2008

AbstractAdvances in drug therapy, hematopoietic stem cell transplantation, and technology have improved the morbidity and survival for those with sickle cell disease. The effect of this modern therapy on the health‐related quality of life (HRQL) of those with sickle cell disease is not known. HRQL provides an assessment of how an illness, its complications, and its treatment are experienced by a patient. This review will examine prior work in HRQL in sickle cell disease and the rationale for utilizing HRQL as an outcome to measure impact of treatment. In addition, issues to consider when reporting HRQL will be presented. Pediatr Blood Cancer 2008;51:5–9. © 2008 Wiley‐Liss, Inc.
Refining homology models by combining replica‐exchange molecular dynamics and statistical potentials
Authors: Zhu Jiang , Fan Hao , Periole Xavier , Honig Barry , Mark Alan E. 
Published: March 2008

AbstractA protocol is presented for the global refinement of homology models of proteins. It combines the advantages of temperature‐based replica‐exchange molecular dynamics (REMD) for conformational sampling and the use of statistical potentials for model selection. The protocol was tested using 21 models. Of these 14 were models of 10 small proteins for which high‐resolution crystal structures were available, the remainder were targets of the recent CASPR exercise. It was found that REMD in combination with currently available force fields could sample near‐native conformational states starting from high‐quality homology models. Conformations in which the backbone RMSD of secondary structure elements (SSE‐RMSD) was lower than the starting value by 0.5–1.0 Å were found for 15 out of the 21 cases (average 0.82 Å). Furthermore, when a simple scoring function consisting of two statistical potentials was used to rank the structures, one or more structures with SSE‐RMSD of at least 0.2 Å lower than the starting value was found among the five best ranked structures in 11 out of the 21 cases. The average improvement in SSE‐RMSD for the best models was 0.42 Å. However, none of the scoring functions tested identified the structures with the lowest SSE‐RMSD as the best models although all identified the native conformation as the one with lowest energy. This suggests that while the proposed protocol proved effective for the refinement of high‐quality models of small proteins scoring functions remain one of the major limiting factors in structure refinement. This and other aspects by which the methodology could be further improved are discussed. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Effects of ligand binding on the dynamics of rice nonspecific lipid transfer protein 1: A model from molecular simulations
Authors: Lai Yen‐Ting , Cheng Chao‐Sheng , Liu Yu‐Nan , Liu Yaw‐Jen , Lyu Ping‐Chiang 
Published: March 2008

AbstractPlant nonspecific lipid transfer proteins (nsLTPs) are small, basic proteins constituted mainly of α‐helices and stabilized by four conserved disulfide bridges. They are characterized by the presence of a tunnel‐like hydrophobic cavity, capable of transferring various lipid molecules between lipid bilayers in vitro. In this study, molecular dynamics (MD) simulations were performed at room temperature to investigate the effects of lipid binding on the dynamic properties of rice nsLTP1. Rice nsLTP1, either in the free form or complexed with one or two lipids was subjected to MD simulations. The C‐terminal loop was very flexible both before and after lipid binding, as revealed by calculating the root‐mean‐square fluctuation. After lipid binding, the flexibility of some residues that were not in direct contact with lipid molecules increased significantly, indicating an increase of entropy in the region distal from the binding site. Essential dynamics analysis revealed clear differences in motion between unliganded and liganded rice nsLTP1s. In the free form of rice nsLTP1, loop1 exhibited the largest directional motion. This specific essential motion mode diminished after binding one or two lipid molecules. To verify the origin of the essential motion observed in the free form of rice nsLTP1, we performed multiple sequence alignments to probe the intrinsic motion encoded in the primary sequence. We found that the amino acid sequence of loop1 is highly conserved among plant nsLTP1s, thus revealing its functional importance during evolution. Furthermore, the sequence of loop1 is composed mainly of amino acids with short side chains. In this study, we show that MD simulations, together with essential dynamics analysis, can be used to determine structural and dynamic differences of rice nsLTP1 upon lipid binding. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Application of CCSD(T)/(ECP + GCM) for studying gas‐phase electron and proton affinities
Authors: Morgon Nelson H. 
Published: March 2008

AbstractThe aim of this work is to analyze high level [CCSD(T)/ECP + GCM] calculations employed to determine the electron and proton affinities (EA and PA) of a set of molecules. The basis sets were developed for pseudopotential using the GCM procedure. This technique is potentially useful for large molecules containing heavy atoms. It can be classified as a quantum chemistry composite method, and achieves similar performance to the Gaussian theory (G2, G3, and G4) and CBS methods at a lower computational cost. The root mean square deviations (δrmsd) of EA and PA, in comparison to the experimental results, obtained were 0.15 eV and 4.14 kJ mol−1, respectively. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A theoretical study of methanol vinylation reaction mechanism
Authors: Vitkovskaya Nadezhda M. , Larionova Elena Yu. , Kobychev Vladimir B. , Kaempf Natalia V. , Trofimov Boris A. 
Published: March 2008

AbstractThe mechanism of base‐catalyzed nucleophilic addition of methanol to acetylene triple bond (vinylation) in dimethyl sulfoxide (DMSO) and methanol solution was studied using the MP2/6‐311++G**//B3LYP/6‐31G* calculations with solvent effects included via continuum model. The proton abstraction from methanol by nondissociated alkali in DMSO surrounding media to form alkali metal methoxides CH3OM (M = Li, Na, K) was found to occur with a negligible activation barrier. The reasons for facilitation of base‐catalyzed alcohol vinylation in the DMSO medium are discussed in the light of both poor solvation of methoxide ion and a specific coordination of reactants by nondissociated alkali in the MOH/DMSO mixtures. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
On the possible removal of nitrogen monoxide and carbon monoxide on copper ion‐exchanged montmorillonite: A DFT study
Authors: Briones‐Jurado Claudia , Agacino‐Valdés Esther 
Published: March 2008

AbstractDFT calculations have been carried out in order to study the possibilities of Cu ion‐exchanged Montmorillonite to act as matrix in two important chemical processes: the possible NO bond breaking in NO molecule and the CO2 formation as the result of CO oxidation. The adsorptions of NO, CO and O2 on Cu+1‐Montmorillonite (Cu+1‐MMT) were modeled using the cluster methodology at the BLYP level of theory. The binding energies related with the adsorption processes of CO, NO and O2 were of −30, −26 and −13 kcal/mol, respectively; these results indicate that the corresponding processes are favored. Moreover, it was found that the oxidation of CO throughout a Langmuir‐Rideal type unimolecular mechanism is a highly favored process because the change of the electronic energy was of −166, 26 kcal mol−1. In relation to NO molecule, a coadsorption of a second molecule was attempted; the negative value of −19.56 kcal mol−1 for the change in the electronic energy suggests that a second NO molecule can also be adsorbed and probably a dimer of NO could be formed. According to the results we think that Cu ion‐exchanged Montmorillonite could be an interesting catalytic system to be tested in environmental applications. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Negative ion mode matrix‐assisted laser desorption/ionisation time‐of‐flight mass spectrometric analysis of oligosaccharides using halide adducts and 9‐aminoacridine matrix
Authors: Becher Jana , Muck Alexander , Mithöfer Axel , Svatoš Aleš , Boland Wilhelm 
Published: March 2008

Abstract9‐Aminoacridine was established as a matrix for the detection of neutral oligosaccharides in negative ion mode matrix‐assisted laser desorption/ionisation time‐of‐flight (MALDI‐TOF) mass spectrometry. Sodium iodide proved to be a useful additive inducing formation of stable iodide adducts of the analytes, in particular for oligosaccharides with a degree of polymerisation (DP) of three and higher. Lower oligomers (DP <3) and monosaccharides show more stable adducts with chloride ions. After optimisation of the sample preparation procedure, limits of quantitation were determined for α‐cyclodextrin and cellopentaose at 7 and 13 pmol, respectively, with a linear detector response over two concentration orders. The iodide additive could be successfully employed on MALDI‐TOF mass spectrometers with vacuum and atmospheric pressure ion sources. The value of the new method to solve biological problems has been demonstrated by the analysis of a mixture of β‐glucane elicitors isolated from the cell walls of Phytophthora sojae. Copyright © 2008 John Wiley & Sons, Ltd.
Development of a dual‐spray electrospray deposition system for matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Erb William J. , Owens Kevin G. 
Published: March 2008

AbstractA new method of matrix‐assisted laser desorption/ionization (MALDI) sample preparation using a dual‐spray electrospray deposition system is demonstrated and employed for the investigation of gas‐phase cationization reactions in the MALDI plume. The dual‐spray electrospray system is found to increase the homogeneity of the sample similarly to that of a conventional single‐spray electrospray system. The dual‐spray electrospray system allows for intimate mixing of separately prepared sample components and results in improved quantitative results. The development of this device also leads to the possibility of mixing sample components prepared in different solvents without the need to be concerned with solvent miscibility. Copyright © 2008 John Wiley & Sons, Ltd.
Absolute quantification of cardiac troponin T by means of liquid chromatography/triple quadrupole tandem mass spectrometry
Authors: Cavaliere Chiara , Cucci Francesca , Guarino Chiara , Gubbiotti Riccardo , Samperi Roberto , Laganà Aldo 
Published: March 2008

AbstractA liquid chromatography/tandem mass spectrometric method for absolute quantification of cardiac troponin T (cTnT) in mouse heart tissue is presented. Even in such a complex biological sample, the multiple reaction monitoring acquisition mode allowed the selective and sensitive determination of a specific peptide, obtained by cTnT enzymatic digestion. The concentration of this cTnT‐specific peptide was considered as a representation of the concentration of its parent protein. Quantification was carried out by means of the matrix‐matched calibration curve, constructed by adding the synthetic standard of the target peptide and another synthetic structurally analogous peptide as internal standard. Method identification limit and method quantification limit were estimated as 60 and 110 ng of cTnT per mg of total extracted proteins, respectively. The developed label‐free approach has been applied for the absolute quantitation of cTnT because of its diagnostic and prognostic value as cardiac disease marker. However, the method could be of general application, since it requires only the synthesis of two suitable peptides, a protein tryptic cleavage product and an internal standard. Copyright © 2008 John Wiley & Sons, Ltd.
Comparative performance of tripole and quadrupole ion guides at elevated pressure
Authors: Misharin Alexander S. , Moskovets Eugene , Gamage Chaminda M. , Doroshenko Vladimir M. , Vilkov Andrey N. 
Published: March 2008

AbstractThis study presents the first practical demonstration of an operational tripole ion guide. The transmission was measured for both the tripole and quadrupole ion guides at 1 Torr pressure. It was found that the quadrupole provides 2.5–3 times better ion transmission efficiency. Two different electric schemes for driving the tripole were tested. Similar transmission characteristics were obtained in both cases. A brief analysis of the tripole performance and ways to improve it is presented. Copyright © 2008 John Wiley & Sons, Ltd.
Numerical reconstruction of wavefront in phase‐shifting point diffraction interferometer by digital holography
Authors: Matsuura Toshiaki , Okagaki Satoru , Oshikane Yasushi , Inoue Haruyuki , Nakano Motohiro , Kataoka Toshihiko 
Published: March 2008

AbstractA phase‐shifting point diffraction interferometer (PS/PDI) is applied for absolute surface figure measurement for large aperture optics. The intensity and phase distributions of measurement wavefront containing the surface figure profile are measured on the projection plane. The phase map gives the surface figure of the mirror. However, the wavefront reflected by the test mirror changes itself while propagating due to the surface figure of the mirror and the position of the point light source. The wavefront is different from the surface figure on the projection plane. For absolute surface profiling, the wavefront on the mirror has to be reconstructed from the measurement results. To reconstruct the wavefront digital holography has been studied. We have developed the numerical reconstruction method by using the Helmholtz–Kirchhoff formula. Spherical concave mirror measurements have been simulated to verify the availability. Ideal spherical mirror measurements, aspherical mirror measurements and a spherical mirror measurement in which the point light source was slightly displaced were simulated. As a result, the phase map on the projection plane did not fit the surface figure. It was also revealed that the light intensity distribution causes changes in the wavefront. In contrast, the reconstructed phase map on the mirror gave the real surface figure. For precise reconstruction the number of sampling on the projection plane must be increased. Copyright © 2008 John Wiley & Sons, Ltd.
Bayesian hierarchical modeling of drug stability data
Authors: Chen Jie , Zhong Jinglin , Nie Lei 
Published: March 2008

AbstractStability data are commonly analyzed using linear fixed or random effect model. The linear fixed effect model does not take into account the batch‐to‐batch variation, whereas the random effect model may suffer from the unreliable shelf‐life estimates due to small sample size. Moreover, both methods do not utilize any prior information that might have been available. In this article, we propose a Bayesian hierarchical approach to modeling drug stability data. Under this hierarchical structure, we first use Bayes factor to test the poolability of batches. Given the decision on poolability of batches, we then estimate the shelf‐life that applies to all batches. The approach is illustrated with two example data sets and its performance is compared in simulation studies with that of the commonly used frequentist methods. Copyright © 2008 John Wiley & Sons, Ltd.
On effect‐measure modification: Relationships among changes in the relative risk, odds ratio, and risk difference
Authors: Brumback Babette , Berg Arthur 
Published: March 2008

AbstractIt is well known that the presence or absence of effect‐measure modification depends upon the chosen measure. What is perhaps more disconcerting is that a positive change in one measure may be accompanied by a negative change in another. Therefore, research demonstrating that an effect is ‘stronger’ in one population when compared with another, but based on only one measure, for example, the odds ratio, may be difficult to interpret for researchers interested in another measure. The present article investigates relationships among changes in the relative risk, odds ratio, and risk difference from one stratum to another. Monte Carlo integration shows that the three measures change in the same direction for 78 or 89 per cent of the volume of the geometric space defined by the four underlying proportions, depending on whether the strata are presumed to share the same direction of effect or not. Analytic results are presented concerning necessary and sufficient conditions for the measures to change in opposite directions. In general, the conditions are seen to be quite complicated, though they do give way to some interesting results. For example, when exposure increases risk but all risks are less than 0.5, it is impossible for the relative risk and risk difference to change in the same direction but opposite to that of the odds ratio. Both data‐analytic and hypothetical examples are presented to demonstrate circumstances under which the measures change in opposite directions. Copyright © 2008 John Wiley & Sons, Ltd.
The influence of dietary fatty acids and environmental temperature on the fatty acid composition of teleost fish
Authors: Reiser Raymond , Stevenson Bernadette , Kayama Mitsu , Choudhury R. B. R. , Hood D. W. 
Published: March 2008

AbstractMarine and fresh water fish were depleted of tissue unsaturated fatty acids to various degrees and subsequently presented with linoleic and linolenic acids at different dietary levels, at different temperatures, with and without other dietary fat.Examination of the tissue fatty acids demonstrated that marine and fresh water fish do not differ between themselves or from other classes of animals in the following basic mechanisms of deposition and interconversions of dietary fatty acids:

The fish are readily depleted of tissue polyunsaturated fatty acids.
Dietary linoleic and linolenic acids are deposited, the former to a greater degree than the latter.
At high levels of linoleic or linolenic acids in the diet there is no significant degree of their conversion to the longer chain more highly unsaturated acids typical of marine oils.
At low levels of linoleic or linolenic acids in the tissues there is a significant, but slight, conversion to the longer chain acids at low environmental temperatures.
The increase in the level of linoleic acid in tissue lipids which accompanies increases in the dietary levels, quickly tapers off above dietary levels of 5%.
Temperature differences between 13 and 23C had little or no influence on the deposition or interconversion of polyunsaturated acids.
Dietary cottonseed oil, which contains cyclopropene fatty acids, produces an increase in tissue stearic acid in the fundulus.
The quantitative analysis of triglyceride mixtures by thin layer chromatography on silica impregnated with silver nitrate
Authors: Barrett C. B. , Dallas M. S. J. , Padley F. B. 
Published: March 2008

AbstractThe paper describes a procedure involving thin layer chromatography on silica impregnated with silver nitrate, which makes possible the separation of synthetic and natural glyceride mixtures into classes according to their degree of unsaturation, and within those classes the resolution of certain isomeric unsaturated glycerides. The separations depend upon the ability of compounds having an olefinic double bond to form co‐ordination complexes with the silver ion.For qualitative analysis, developed chromatoplates are sprayed with dibromofluorescein. Reliable quantitative data may be obtained by charring the separated glycerides with phosphoric acid under carefully controlled conditions, and comparing the densities of the charred areas by means of a photodensitometer. Experiments with mixtures of pure synthetic glycerides revealed an error of less than 3%.Glyceride compositions of a number of natural fats have been determined, and compared with compositions obtained by enzymetic hydrolysis of the same samples.
N‐Carbamylglutamate for neonatal hyperammonaemia in propionic acidaemia
Authors: Jones S. , Reed C. A. B. , Vijay S. , Walter J. H. , Morris A. A. M. 
Published: March 2008

SummaryHyperammonaemia is common in neonates with branched‐chain organic acidaemias, primarily due to the inhibition of N‐acetylglutamate (NAG) synthetase; NAG is an activator for carbamylphosphate synthetase I, the first enzyme of the urea cycle. N‐Carbamylglutamate, a NAG analogue, has been reported to correct hyperammonaemia in neonates with organic acidaemias. It is, however, uncertain how the ammonia concentrations in these neonates would have progressed without the drug. We report a neonate with propionic acidaemia, whose plasma ammonia concentration responded dramatically to N‐carbamylglutamate, having previously been over 950 μmol/L for 33 h. Our patient presented with poor feeding, hypoglycaemia, acidosis and hyperammonaemia (1044 μmol/L at 65 h of age). The patient was treated with intravenous glucose (12 mg/kg per min), insulin, sodium benzoate, sodium phenylbutyrate, carnitine and continuous veno‐venous haemofiltration (CVVH). In spite of these measures, the plasma ammonia concentration remained above 950 μmol/L. After 30 h of CVVH, N‐carbamylglutamate (250 mg/kg) was given through a nasogastric tube. Over the following 4 h, the plasma ammonia fell from 1410 μmol/L to 267 μmol/L. Despite stopping CVVH, the ammonia level dropped to 137 μmol/L over the next 2 h and it continued to fall while the intravenous drug doses were reduced. The patient was readmitted, aged 4 weeks, with hyperammonaemia (347 μmol/L) and again this responded to N‐carbamylglutamate. In contrast, we report a previous patient with propionic acidaemia who showed no response to a lower dose of N‐carbamylglutamate (25 mg/kg).
Interaction between anxiety, depression, quality of life and clinical parameters in chronic tension‐type headache
Authors: Peñacoba‐Puente Cecilia , Fernández‐de‐las‐Peñas César , González‐Gutierrez Jose L. , Miangolarra‐Page Juan C. , Pareja Juan A. 
Published: March 2008

AbstractOur aim was to investigate the mediating or moderating role of anxiety and depression in the relationship between headache clinical parameters and quality of life in Chronic Tension‐Type Headache (CTTH). Twenty‐five patients diagnosed with CTTH according to the criteria of the International Headache Society were studied. A headache diary was kept for 4 weeks in order to substantiate the diagnosis and record the pain history. Quality of life was assessed by means of the Medical Outcome Study (MOS) 36‐Item Short‐Form (SF‐36) questionnaire. The Beck Depression Inventory (BDI‐II) was used to assess depression, and the Trait Anxiety Scale (TA) from the State‐Trait Anxiety Inventory was administered in order to assess anxiety. Moderating and mediating analyses were conducted with ordinary least squares multiple regression analysis using the SPSS General Linear Model procedure. Anxiety mediated the effect between headache frequency and quality of life, but not the effect of either headache intensity or duration. Anxiety totally mediated the effects of headache frequency on vitality, social functioning and mental health. On the other hand, depression modulated the effect in the mental health domain. The effect in the mental health domain was a function of the interaction between headache duration and depression (β=−0.34, p<0.05), after controlling for age, gender, the main effects of headache duration, and depression. We did not find anxiety to be a moderating factor between intensity, frequency or duration of headache and perceived quality of life. Anxiety exerts a mediating effect, conditioning the relationship between headache frequency and some quality of life domains; depression seems to play an inherent role in the reduced quality of life of these patients, that is, it has a moderating effect.