bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes of chemical composition and dough rheology in two fractions of sieve‐classified Polish spring wheat flour
Authors: Konopka Iwona , Drzewiecki Jerzy
Published: April 2004

The study of chemical composition and dough rheology changes in sieve‐classified two fractions (up to 60 and 60–240 μm particles) of wheat flour was the subject of this study. The straight grade flours were obtained by the milling of three Polish varieties of spring wheat, differing in •• abbreviation? (PSI) values. The flours were separated with the use of a SZ‐1 laboratory sifter. The yield of fine fraction was in the range 50.0–55.7%. The obtained fractions were assayed for the content and composition of free lipids, gluten proteins, damaged starch, ash, water absorption and amylograph viscosity. Dough rheology (extrusion in OTMS cell, alveograph and farinograph tests) and baking trials were also performed. The content of free lipids, including the non‐polar and phospholipids was lower and the content of glycolipids was higher in fine flours. Those fractions were more rich in linoleic acid but the lower content of oleic and linolenic acids resulted in a higher oxidizability index of free lipids. Fine flours contained less ash and significantly more damaged starch. At the same time, they were characterized by a higher content of wet gluten, water absorption, amylograph viscosity and better dough parameters. This was reflected in the bread volume, which was higher by 6.3–10.7%. The influence of the changes in composition and the content of free lipids upon the rheology of the dough after the 90 days flour storage has not been defined unambiguously and requires further research.
Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats
Authors: Regulska‐Ilow Bożena , Biernat Jadwiga , Grajeta Halina , Ilow Rafał , Drzewicka Maria
Published: April 2004

The aim of this study was to assess the influence of bioflavonoids from the radix of Scutellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high‐density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high‐fat and high‐cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 ± 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 ± 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.
Sensory and rheological properties of transgenically and chemically modified starch ingredients as evaluated in a food product model
Authors: Ahmt Tina , Wischmann Bente , Blennow Andreas , Madsen Finn , Bandsholm Ole , Thomsen Jens
Published: April 2004

Starches derived from five genetically modified potato lines, two chemically modified potato starches and two native starches from potato and maize were subjected to physical and chemical analyses and their functionality evaluated in a milk‐based food product model. The transgenic starches were specifically modified with respect to amylopectin chain length and phosphorous content by suppression of the starch branching enzyme and overexpression of glycogen branching enzyme. Transgenic starches with long amylopectin chains and high phosphorous content had increased gelatinisation temperatures, produced gels with a higher tendency to retrograde and a low freeze/thaw stability as compared to starches with shorter amylopectin chains and lower phosphorous content. The textural properties of the food product model prepared from genetically and chemically modified starches were characterised by sensory and rheological analyses. To clearly visualise the effects of the modifications, data was evaluated by radar plots and multiple regression analysis (chemometrics). Genetically modified potato starches with longer amylopectin chains and increased phosphorous content gave a more gelled and a shorter texture as compared to starches with shorter amylopectin chains and decreased phosphorous content. Acetylated and hydroxypropylated potato starches gave sticky and stringy textures. Correlations between rheology parameters and sensory parameters were found. The sensory parameter stringy/long could be predicted from the rheological data.
A utility‐theoretic approach to the aggregation of willingness to pay measured in decomposed scenarios: development and empirical test
Authors: Hammerschmidt Thomas , Zeitler Hans‐Peter , Leidl Reiner
Published: April 2004

For cost–benefit analysis, health technologies with multiple effects should be valued in a single scenario by a holistic willingness‐to‐pay (WTP) measure. Recent studies instead used decomposed scenarios in which respondents report their WTP for each individual effect. Evidence can be found that the sum of such decomposed WTPs overestimates the holistic WTP, i.e. the holistic WTP is sub‐additive. This sum of decomposed WTPs can lead to wrong conclusions on the efficiency of health technologies. This is also relevant in decision making about new technologies that are valued separately in different surveys. To date, no utility‐theoretical and empirically validated aggregation function for decomposed WTPs exists. Within an expected utility model, this paper identifies as a reason for sub‐additivity – beside risk aversion with respect to wealth – a negative influence of better health on the marginal utility of wealth, i.e. marginal utility of wealth is smaller in better health states. Assuming mutual utility independence of health and wealth, a theoretically founded aggregation function covering these two impacts is derived. In a contingent valuation study, 92 patients with diabetes were asked to state their WTP for reductions of the risk of several diabetic complications in decomposed as well as in holistic scenarios. The patients had preferences with a significant negative influence of health on the marginal utility of wealth. Sub‐additivity occurred and theoretically founded aggregation could considerably lower the degree of overestimation. These results suggest that the theoretically founded aggregation function might reduce problems of sub‐additivity that can be economically relevant. Further empirical testing of the approach is indicated. Copyright © 2003 John Wiley & Sons, Ltd.
Does more choice reduce waiting times?
Authors: Siciliani Luigi
Published: April 2004

This paper develops a model of the supply of elective treatments within a duopolistic market structure where patients can be referred to the hospital with the lowest waiting times. We investigate the effect of a higher degree of substitutability among the two hospitals on equilibrium supply, waiting time and the size of the waiting list. The degree of substitutability is interpreted as the degree of choice or the extent to which patients can switch from one hospital to the other.

We show that the greater the degree of substitutability among hospitals, the lower is the supply and the higher the waiting time. The effect on waiting list size is ambiguous. This result holds either when the hospital is remunerated with a fixed budget or with activity‐based funding. However, the reduction in supply and the increase in waiting time generated by higher substitutability are higher when hospitals are remunerated with fixed budgets. The main implication of the model is that, under certain assumptions, policies aimed at increasing provider choice may fail to reduce waiting times. Copyright © 2004 John Wiley & Sons, Ltd.
Testing the internal consistency of the lottery equivalents method using health outcomes
Authors: Oliver Adam
Published: April 2004

The standard gamble has a firm basis in the theory of risk and, for this reason, is the preferred method of health state value elicitation for many researchers. However, it is widely recognised that the use of immediate death as the failure outcome in the standard gamble renders the method insufficiently sensitive for the direct valuation of minor and temporary health states. Consequently, the indirect valuation of minor and temporary health states through a process of ‘chaining’ has been recommended. Unfortunately, a number of researchers have observed internal inconsistency in the standard gamble. That is, for health states that are not thought to be subject to the above mentioned insufficient sensitivity, the values elicited from indirect chained questions quite often significantly and systematically exceed those elicited from the direct procedure. A potential explanation for this is the possible influence of loss aversion when people are asked to weigh certainty against risk. The lottery equivalents method, an alternative value elicitation instrument that also has a firm grounding in the theory of risk, modifies the standard gamble approach of certainty versus risk to one of risk versus risk. The absence of certainty offers reason to suspect that the influence of loss aversion will be diminished (or even removed), and that the lottery equivalents method will thus prove to be internally consistent. The study reported in this article tests the internal consistency of the lottery equivalents method. In a manner similar to that observed with the standard gamble, the results indicate that the internal consistency of the lottery equivalents method is also to some extent compromised. Copyright © 2004 John Wiley & Sons, Ltd.
Heterologous CpG island becomes extensively methylated in the genome of transgenic mice
Authors: Ioudinkova Elena , Verbovaia Lilia , Kadulin Sergey , Goldman Igor , Razin Sergey V.
Published: April 2004

It is demonstrated that a heterologous (chicken) CpG island containing five Sp1 canonical recognition sequences becomes highly methylated in the genome of transgenic mice bearing one or several copies of the transgene. Similar levels of methylation of the chicken CpG island were observed in different tissues of transgenic mice except the brain where the level of methylation of this chicken CpG‐rich fragment was significantly lower than in other tissues. Analysis of susceptibility of the “transgenic” CpG island to Hpa II and Msp I restriction nucleases revealed an unusual methylation pattern interfering with the action of both of these enzymes. A conclusion has been drawn that heterologous CpG island per se does not contain all necessary signals permitting to maintain its own non‐methylated status in the genome of transgenic animals. © 2004 Wiley‐Liss, Inc.
Induction of G1 cell cycle arrest and P15INK4b expression by ECRG1 through interaction with Miz‐1
Authors: Zhao Nianxi , Wang Jianbo , Cui Yongping , Guo Liping , Lu Shih‐Hsin
Published: April 2004

ECRG1 is a novel candidate of tumor suppressor gene identified from human esophagus. To study the biological role of ECRG1 gene, we performed a GAL4‐based yeast two‐hybrid screen of a human fetal liver cDNA library. Using the ECRG1 cDNA as bait, we identified two putative clones as associated proteins, Miz‐1 and FLNA (Filamin A). The interaction of ECRG1 and Miz‐1 was confirmed by glutathione‐S‐transferase (GST)‐pull‐down assays in vitro and co‐immunoprecipitation experiments in vivo. ECRG1 was co‐localized with Miz‐1 in nucleus, as shown by confocal microscopy. Transfection of ECRG1 gene into the esophageal cancer (EC) cells inhibited cell proliferation and induced G1 phase arrest of cell cycle. In the co‐transfection of ECRG1 and Miz‐1 assays, we found inhibition of cell proliferation and G1/S phase in EC cells, but the levels of cell proliferation inhibition and G1/S phase arrest were more strongly compared with the transfection of ECRG1 or Miz‐1 alone. In addition, the interaction of ECRG1 and Miz‐1 could induce expression of P15INK4b gene in esophageal cancer 9706 (EC9706) cells. However, the transfection of ECRG1 or Miz‐1 alone was not revealed the expressions of P15INK4b gene. When antisense ECRG1 interdicted expression of endogenous ECRG1 in Balb/c‐3T3 cells, Transfection of Miz‐1 couldn't induce P15INK4b expression. The results provide evidences that ECRG1 and Miz‐1 in EC cells may be acting as a co‐functional protein associated with regulation of cell cycle and induction of P15INK4b expression. It suggests that ECRG1 may inhibit tumor cell growth by affecting cell cycle, and that expression of P15INK4b may be likely to enhance G1 cell cycle arrest during the interaction of ECRG1 and Miz‐1. The physical interaction of ECRG1 and Miz‐1 may play an important role in carcinogenesis of EC. © 2004 Wiley‐Liss, Inc.
Role of Citrobacter amalonaticus and Citrobacter farmeri in dissimilatory perchlorate reduction
Authors: Bardiya Nirmala , Bae JaeHo
Published: April 2004

The article deals with the novel physiological function of dissimilatory perchlorate reduction by strains JB101 and JB109 isolated from a laboratory‐enriched mixed consortium originating from a sewage treatment facility. The biochemical and physiological data of the strains showed good correspondence with members of the family Enterobacteriaceae. The partial 16S rDNA sequence of the strains JB101 and JB109 had similarity of 99.8% to Citrobacter amalonaticus and 98% to Citrobacter farmeri, respectively. The results inferred the possibility of Citrobacter spp. to form an important group of dissimilatory perchlorate reducers among the γ subclass of Proteobacteria, since the majority of the perchlorate reducers belong to two monophyletic groups, Dechloromonas and Dechlorosoma in β subclass. The perchlorate‐grown Citrobacter strains preferred perchlorate to nitrate as an electron acceptor unlike most of the reported dissimilatory perchlorate reducers. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparative analysis of laccase‐isozymes patterns of several related Polyporaceae species under different culture conditions
Authors: AranaCuenca Ainhoa , Roda Arantxa , Téllez Alejandro , Loera Octavio , Carbajo José M. , Terrón María C. , González Aldo E.
Published: April 2004

The study of isozymes has to date been successfully applied in the identification of a number of different microorganisms, particularly fungi. Trametes sp. I‐62 (CECT20197) is a white‐rot fungus with potential biotechnological applications. It has been identified as Trametes on the basis of the mycelium morphology, but the features observed are not sufficient for its classification at the species level. Given that this strain produces a very characteristic laccase isozyme pattern, in the present work we compared its isozyme profile with the profiles produced by ten other very closely phylogenetically related fungi from the Polyporaceae family. The data indicates that Trametes sp. I‐62 could not be included in any of the taxonomically related species which were analysed in the present work. Extracellular laccases were detected in nine of the fungi studied and in four of them namely Trametes subectypus, Trametes pavonia, Trametes ochracea and Trametes gallica, this is the first report of such activity. Given that phylogenetically related fungi growing in the same culture conditions exhibit different laccase patterns, these isozymes could be used as an additional criterion for fungal identification. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dimensionality estimate of the manifold in chemical composition space for a turbulent premixed H2 + air flame
Authors: Tonse Shaheen R. , Brown Nancy J.
Published: April 2004

The dimensionality (${\cal D}$) of manifolds of active chemical composition space has been measured using three different approaches: the Hausdorff geometrical binning method, Principal Component Analysis, and the Grassberger‐Procaccia cumulative distribution method. A series of artificial manifolds is also generated using a Monte Carlo approach to discern the advantages and limitations of the three methods. Dimensionality is quantified for different levels of turbulent intensity in a simulation of the interactions of a 2D premixed hydrogen flame with a localized region of turbulence superimposed over the cold region upstream of the flame front. The simulations are conducted using an adaptive mesh refinement code for low Mach number reacting flows. By treating the Ns species and temperature of the local thermo‐chemical state as a point in multidimensional chemical composition space, a snapshot of a flame region is mapped into chemical composition space to generate the manifold associated with the 2‐D flame system. An increase in ${\cal D}$ was observed with increasing turbulent intensity for all three methods. Although each method provides useful information, the Grassberger‐Procaccia method is subject to fewer artifacts than the other two thereby providing the most reliable quantification of ${\cal D}$. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 326–336, 2004
Cover Picture: Macromol. Rapid Commun. 7/2004
Authors: Maupin Paul H. , Gilman Jeffrey W. , Harris Richard H. , Bellayer Severine , Bur Anthony J. , Roth Steven C. , Murariu Marius , Morgan Alexander B. , Harris Joseph D.
Published: April 2004

Cover: The pictures show melt processed polyamide‐6 nanocomposites at 1 min (left) and 7 min (right) processing. The structure on the right is of Nile Blue A. Below each is the respective TEM of the nanocomposites and the graph at the bottom illustrates their fluorescence spectra.

Further details can be found in the Communication by P. H. Maupin,* J. W. Gilman, R. H. Harris, Jr., S. Bellayer, A. J. Bur, S. C. Roth, M. Murariu, A. B. Morgan, and J. D. Harris on page 788.
Comparison of different methods for the preparation of porous bone substitution materials and structural investigations by synchrotron μ‐computer tomography
Authors: Tadic D. , Beckmann F. , Donath T. , Epple M.
Published: April 2004

The preparation of porous biomaterials for bone substitution is an important clinical issue in current biomedical technology because the ingrowth of bone can only occur if a suitable number of sufficiently large pores is available. Different procedures are compared here: The combined chemical‐thermal treatment of bovine and human cancellous bone, the calcination of bovine cancellous bone, mechanical hole‐drilling, and the extraction of porogens (in this case: salt crystals). The inner structure and the porosity of all samples were studied using high‐resolution synchrotron μ‐computer tomography.
Functional Materials for Bone Regeneration from Beta‐Tricalcium Phosphate
Authors: Peters F. , Reif D.
Published: April 2004

Biodegradable ceramics of β‐tricalcium phosphate (β‐TCP, Ca3(PO4)2) are widely used as bone regeneration materials. The goal is a complete regeneration of the bony defect (restitutio ad integrum = full recovery). Different bioceramics made of β‐TCP show fundamental differences in terms of phase purity, primary particle size, stability, porosity, solubility and therefore biodegradation of the material.

Cerasorb® is a bioceramic consisting of phase pure β‐TCP. The primary particle size in connection with a stable sinter structure forms a porous biomaterial which is optimised in the functional surface, porosity and resorption/degradation behaviour. Different forms of Cerasorb® are available: granular materials with high and low porosity optimised for specific indications as well as block forms shapeable by the surgeon for various bony defects.
Individuelle Implantate aus biodegradierbarem Kompositmaterial zur Versorgung von Schädeldefekten
Authors: Weihe S. , Rasche C. , Schiller C. , Wehmöller M. , Böckmann R. , Eufinger H. , Epple M.
Published: April 2004

Titan ist ein etabliertes Knochenersatzmaterial für die Versorgung komplexer Schädeldefekte mittels individuell geplanter CAD/CAM‐Implantate. Zur Verbesserung der durch Patientenkontrollstudien evaluierten thermischen und psychischen Belastungsfaktoren wurde in der vorliegenden Studie ein gradiertes Kompositmaterial aus Polymeren und Calciumphosphat bzw. Calciumcarbonat entwickelt. Biokompatibilitätsuntersuchungen auf Basis des ISO‐Standards 10993‐5 erlaubten zunächst die Auswahl geeigneter Materialien sowie nachfolgend die Feststellung der verbesserten pH‐Charakteristika der Kompositmaterialien gegenüber den reinen Polymeren. Für die geometrisch korrekte Herstellung der Implantate aus Kompositmaterialien wurden zwei unterschiedliche Verarbeitungsmethoden gewählt und kombiniert. Diese Implantate konnten bereits durch in‐vivo Versuche an einem eigens entwickelten Großtiermodell getestet werden und zeigten post mortem bei einem Nachbeobachtungszeitraum von zwei Monaten keine histologischen Reaktionen außerhalb der Norm und eine beginnende Knochenbildung. Klinisch ergaben sich bei den lebenden Schafen auch nach einem Zeitraum von bisher 11 Monaten keinerlei Komplikationen.
Verbesserung der knöchernen Integration von Schanz’ Schrauben durch eine Poly(D,L‐laktid) Beschichtung
Authors: Duda G. N. , Partale K. , Klein P. , Schell H. , Schiller R. A. , Wildemann B. , Schmidmaier G. , Bail H.
Published: April 2004

Schraubenkanal‐Infektionen und Schraubenlockerungen sind wesentliche Komplikationen bei der Fixateur externe‐Osteosynthese. In dieser Studie wurde der Einfluss einer Poly(D,L‐laktid)‐Beschichtung auf die ossäre Integration der Schrauben während der Frakturversorgung analysiert.

An 16 Schafen wurden Osteotomien der rechten Tibia mit einem monolateralen Fixateur externe stabilisiert. Zusätzlich wurden mechanisch unbelastete Schanz' Schrauben eingebracht. Die Hälfte der implantierten Schrauben wurde mit Poly(D,L‐laktid) beschichtet. Nach neun Wochen wurden die Schrauben entnommen, auf Blutagar‐Platten ausgerollt und mikrobiologisch untersucht. Es erfolgte die histologische Aufarbeitung der Pintrakts und eine anschließende histochemische und histomorphometrische Analyse. Obwohl klinisch keine Anzeichen für Infektionen beobachtet wurden, zeigte die mikrobiologische Bewertung bei 15 % der beschichteten Schrauben versus 29 % der unbeschichteten Schrauben eine Kontamination durch Staphylococcus aureus. Die histologische Auswertung zeigte, dass beschichtete Schrauben eine bessere Osteointegrität (p=0,0006) als unbeschichtete Implantate aufwiesen. In der Histomorphometrie wurde in der Gruppe der unbeschichteten Schrauben ein höheres knöchernes Remodeling (p = 0,006) und eine höhere Osteoklastenaktivität (p = 0,019) festgestellt. Belastete Schrauben zeigten mehr Kallus am Schraubenaustritt (p = 0,048). Eine Poly(D,L‐laktid)‐Beschichtung bei Schanz' Schrauben scheint die ossäre Integration durch eine Verminderung des kortikalen Remodelings und der Osteoklastenaktivität zu verbessern.
Defining hormone replacement therapy in longitudinal studies: impact on measures of effect
Authors: Csizmadi Ilona , Collet Jean‐Paul , Benedetti Andrea , Boivin Jean‐François , Hanley James A.
Published: April 2004

Data from a nested case‐control study, designed to examine the effect of hormone replacement therapy (HRT) on colorectal cancer risk, were analyzed to determine the effect of exposure definition on the estimation of risk ratios (RR). A prescription drug plan database was used to ascertain HRT prescriptions dispensed prior to index dates to cases (n = 3059) and age‐matched controls (n = 12 116). HRT exposure was defined as ‘prescription’ and ‘tablet’ counts, ‘conjugated estrogen only’ and a method based on proportions of minimum exposure to a number of estrogens (SUM‐P3 and SUM‐P12). The effect of HRT was described with reference to ‘ever’, < 5 and ≥ 5 years of HRT use. Conditional logistic regression was used to estimate ORs and 95% confidence intervals (CI). Adjusted ORs for ‘ever use’ of HRT ranged from 0.72 (95%CI: 0.60–0.88) to 0.86 (95%CI: 0.76–0.99); for <5 years use, from 0.70 (95%CI: 0.56–0.88) to 0.89 (95%CI: 0.78–1.01) and for ≥5 year of HRT use, from 0.74 (95%CI: 0.59–0.92) to 0.98 (95%CI: 0.42–2.26). Various methods used to define HRT exposure produce a range of estimated ORs that vary in magnitude similar to results reported in the literature from observational studies investigating the association between HRT and colorectal cancer. Copyright © 2003 John Wiley & Sons, Ltd.
What is prescription labeling communicating to doctors about hepatotoxic drugs? A study of FDA approved product labeling
Authors: Willy Mary E. , Li Zili
Published: April 2004

Purpose

The objective of this study was to evaluate the informativeness and consistency of product labeling of hepatotoxic drugs marketed in the United States.

Methods

We searched the Physicians' Desk Reference—2000 for prescription drugs with hepatic failure and/or hepatic necrosis listed in the labeling. We used a six‐item checklist to evaluate the ‘informativeness’ and consistency of the labeling content. An informativeness score equaled the proportion of checklist items present in each drug's labeling.

Results

Ninety‐five prescription drugs were included in the study. Eleven (12%) of the drugs had information related to hepatic failure in a Black Boxed Warning, 52 (54%) in the Warnings section and 32 (34%) in the Adverse Reactions section of the label. The mean informativeness score was 35%; the score was significantly higher, 61%, when the risk was perceived to be high. The informativeness of labeling was not affected by the time of the labeling, but differed across the Center for Drug Evaluation and Research (CDER) Review Division responsible for the labeling.

Conclusions

The information provided in labeling is variable and affected by many factors, including the perceived level of risk and review division strategy. Product labeling may benefit from current FDA initiatives to improve the consistency of risk‐related labeling. Published in 2003 by John Wiley & Sons, Ltd.
Protein secondary structure assignment through Voronoï tessellation
Authors: Dupuis Franck , Sadoc Jean‐François , Mornon Jean‐Paul
Published: April 2004

We present a new automatic algorithm, named VoTAP (Voronoï Tessellation Assignment Procedure), which assigns secondary structures of a polypeptide chain using the list of α‐carbon coordinates. This program uses three‐dimensional Voronoï tessellation. This geometrical tool associates with each amino acid a Voronoï polyhedron, the faces of which unambiguously define contacts between residues. Thanks to the face area, for the contacts close together along the primary structure (low‐order contacts) a distinction is made between strong and normal ones. This new definition yields new contact matrices, which are analyzed and used to assign secondary structures. This assignment is performed in two stages. The first one uses contacts between residues close together along the primary structure and is based on data collected on a bank of 282 well‐refined nonredundant structures. In this bank, associations were made between the prints defined by these low‐order contacts and the assignments performed by different automatic methods. The second step focuses on the strand assignment and uses contacts between distant residues. Comparison with several other automatic assignment methods are presented, and the influence of resolution on the assignment is investigated. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Crystal structure of a putative aspartate aminotransferase belonging to subgroup IV
Authors: Katsura Yasuhiro , Shirouzu Mikako , Yamaguchi Hiroto , Ishitani Ryuichiro , Nureki Osamu , Kuramitsu Seiki , Hayashi Hideyuki , Yokoyama Shigeyuki
Published: April 2004

Protein TT0402 from Thermus thermophilus HB8 exhibits about 30–35% sequence identity with proteins belonging to subgroup IV in the aminotransferase family of the fold‐type I pyridoxal 5′‐phosphate (PLP)‐dependent enzymes. In this study, we determined the crystal structure of TT0402 at 2.3 Å resolution (Rfactor = 19.9%, Rfree = 23.6%). The overall structure of TT0402 exhibits the fold conserved in aminotransferases, and is most similar to that of the Escherichia coli phosphoserine aminotransferase, which belongs to subgroup IV but shares as little as 13% sequence identity with TT0402. Kinetic assays confirmed that TT0402 has higher transamination activities with the amino group donor, L‐glutamate, and somewhat lower activities with L‐aspartate. These results indicate that TT0402 is a subgroup IV aminotransferase for the synthesis/degradation of either L‐aspartate or a similar compound. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Unfolded state of polyalanine is a segmented polyproline II helix
Authors: Kentsis Alex , Mezei Mihaly , Gindin Tatyana , Osman Roman
Published: April 2004

Definition of the unfolded state of proteins is essential for understanding their stability and folding on biological timescales. Here, we find that under near physiological conditions the configurational ensemble of the unfolded state of the simplest protein structure, polyalanine α‐helix, cannot be described by the commonly used Flory random coil model, in which configurational probabilities are derived from conformational preferences of individual residues. We utilize novel effectively ergodic sampling algorithms in the presence of explicit aqueous solvation, and observe water‐mediated formation of polyproline II helical (PII) structure in the natively unfolded state of polyalanine, and its facilitation of α‐helix formation in longer peptides. The segmented PII helical coil preorganizes the unfolded state ensemble for folding pathway entry by reducing the conformational space available to the diffusive search. Thus, as much as half of the folding search in polyalanine is accomplished by preorganization of the unfolded state. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Folding of β/α‐unit scrambled forms of S. cerevisiae triosephosphate isomerase: Evidence for autonomy of substructure formation and plasticity of hydrophobic and hydrogen bonding interactions in core of (β/α)8‐barrel
Authors: Shukla Anshuman , Guptasarma Purnananda
Published: April 2004

The (β/α)8‐barrel domain consists of eight topologically equivalent supersecondary structural motifs known as β/α‐units. Each unit consists of a single β‐strand, an α‐helix, and two loops. Evidence collected in recent years indicates that the (β/α)8‐barrel motif may not be a single, autonomously‐folding domain, as was previously assumed. Segments of some (β/α)8‐barrels appear to fold autonomously. However, the extent to which this is true of various (β/α)8‐barrel domains remains to be explored. In this study, we have scrambled (reshuffled) the native order of β/α‐units (1‐2‐3‐4‐5‐6‐7‐8) comprising the polypeptide chain of a model (β/α)8‐barrel from S. cerevisiae, triosephosphate isomerase (TIM). Total scrambling was effected in order to examine whether folding can still occur to yield β/α‐structures in spite of a global ‘destruction’ of native hydrophobic and hydrogen bonding interactions among β/α‐units, while still allowing the occurrence of native interactions within individual units. Our results demonstrate that scrambled full‐barrel forms (2‐4‐6‐8‐1‐3‐5‐7 and 1‐3‐5‐7‐2‐4‐6‐8), as well as half‐barrel (2‐4‐6‐8) and quarter‐barrel (1‐3) forms of TIM fold into β/α‐structures that sustain tertiary and quaternary structural interactions. In particular, one variant (2‐4‐6‐8‐1‐3‐5‐7) was found to fold and form a stable dimer with native‐like structural content and other characteristics. Our results demonstrate that (β/α)8‐barrels can tolerate profound alterations of both strand–strand interactions responsible for the creation of the β‐barrel and the geometry of presentation of nonpolar sidechains into the hydrophobic core of the β‐barrel by individual β‐strands. These findings lend support to our recent proposal1 that a hierarchy of interactions probably regulates structure formation and stability in (β/α)8‐barrels, where folding proceeds successively through three stages: (i) the tentative formation of individual β/α‐units which associate through ‘near‐neighbor’ diffusion‐collision interactions into (ii) curved assemblies of multiple β/α‐units through sequence‐independent hydrogen bonding of strands of neighboring units, leading finally to (iii) the association of curved (quarter/half‐barrel) assemblies around a common hydrophobic core through packing interactions that remain plastic and amenable to change. Proteins 2004. © 2004 Wiley‐Liss, Inc.
CHOP proteins into structural domain‐like fragments
Authors: Liu Jinfeng , Rost Burkhard
Published: April 2004

We developed a method CHOP dissecting proteins into domain‐like fragments. The basic idea was to cut proteins beginning from very reliable experimental information (PDB), proceeding to expert annotations of domain‐like regions (Pfam‐A), and completing through cuts based on termini of known proteins. In this way, CHOP dissected more than two thirds of all proteins from 62 proteomes. Analysis of our structural domain‐like fragments revealed four surprising results. First, >70% of all dissected proteins contained more than one fragment. Second, most domains spanned on average over ∼100 residues. This average was similar for eukaryotic and prokaryotic proteins, and it is also valid—although previously not described—for all proteins in the PDB. Third, single‐domain proteins were significant longer than most domains in multidomain proteins. Fourth, three fourths of all domains appeared shorter than 210 residues. We believe that our CHOP fragments constituted an important resource for functional and structural genomics. Nevertheless, our main motivation to develop CHOP was that the single‐linkage clustering method failed to adequately group full‐length proteins. In contrast, CLUP—the simple clustering scheme CLUP introduced here—succeeded largely to group the CHOP fragments from 62 proteomes such that all members of one cluster shared a basic structural core. CLUP found >63,000 multi‐ and >118,000 single‐member clusters. Although most fragments were restricted to a particular cluster, ∼24% of the fragments were duplicated in at least two clusters. Our thresholds for grouping two fragments into the same cluster were rather conservative. Nevertheless, our results suggested that structural genomics initiatives have to target >30,000 fragments to at least cover the multimember clusters in 62 proteomes. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Discovery and characterization of novel oxide anodes for solid oxide fuel cells
Authors: Tao Shanwen , Irvine John T.S.
Published: April 2004

The search for alternative anode materials for solid oxide fuel cells (SOFCs) has been reviewed in the light of structure, stability, conductivity, chemical and thermal compatibility with electrolyte YSZ. In this review, we have presented the advantages and disadvantages of the traditional Ni‐YSZ anode for SOFCs. The development of alternative anode for SOFCs with fluorite, rutile, tungsten bronze, pyrochlore, perovskite and spinel structures has been reviewed and discussed in detail. Among the reported materials systems, materials with perovskite structure are promising particularly where two ions with complimentary function are present on the B‐site at high concentration. We have recently found a good redox stable anode (La0.75Sr0.25)1−xCr0.5Mn0.5O3 (0 ≤ x ≤ 0.1) using this approach. These materials exhibit comparable performance to the traditional Ni‐YSZ anode. Therefore, we can use nickel‐free redox stable anode for SOFCs. With further optimisation of the composition and microstructure, the performance of these materials may be further improved and hopefully replace the traditional Ni‐YSZ anode in the future. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 83–95; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20003
Tunable haptotropic metal migration in fused arenes: towards organometallic switches
Authors: Dötz Karl Heinz , Jahr Holger C.
Published: April 2004

Tricarbonyl chromium complexes of naphthalene derivatives are synthesized by chromium‐templated [3 + 2 + 1]‐benzannulation and subjected to thermally induced haptotropic rearrangement experiments. Thermodynamic and kinetic parameters for the metal shift demonstrate the influence of the arene substitution pattern. In turn, the chromium template may be tuned as well by phosphorus coligands which allow to accelerate or slow down the isomerization process; this effect quantitatively reflects the steric and electronic properties of the coligand sphere. Proper adjustment of the template allows for a photo‐induced reverse migration of the chromium moiety which results in a switchable organometallic device. Experiments with enantiopure arene chromium complexes indicate a stereospecific metal migration. The rearrangement proceeds by an intramolecular mechanism in both directions. Haptotropic isomerization reactions are not limited to bicyclic arenes and can be extended from naphthalenes to phenanthrene or tetra‐ and pentacyclic heteroarene systems. © 2004 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 4: 61–71; 2004: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20007
Gaseinlasssystem zur massenspektrometrischen Analyse kleiner Gasproben. Gas Inlet System to Analyse Small Gas Samples by a Mass Spectrometer
Authors: Bux R. , Juhnke Ch. , Klein H. H.
Published: April 2004

Für die quantitative Analyse kleiner Gasproben (< 1 cm3), die menschlichen Leichen mit einer Injektionsspritze entnommen werden, wurde für ein Quadrupol‐Massenspektrometer ein Gaseinlasssystem entwickelt und gebaut. Mit dem entwickelten Gaseinlasssystem können die Gasproben unverfälscht in Zusammensetzung und Größe in einen Probenraum überführt werden, von wo das Gas durch ein UHV‐Nadelventil direkt in die Ionenquelle des Massenspektrometers einströmt. Nach einer sorgfältigen Kalibrierung des Massenspektrometers bezüglich der interessierenden Probenbestandteile können diese quantitativ mit einer Ungenauigkeit von < 1 % bestimmt werden.
Flammenpyrolytische Silikatbeschichtung bei Normaldruck als Alternative zu Vakuumverfahren. Combustion CVD of silica as an alternative method to vakuum treatment
Authors: Richter Thomas , Tiller Hans‐Jürgen
Published: April 2004

In Weiterentwicklung des Pyrosil®‐Verfahrens wurde eine neue Art der Precursoreinspeisung in CCVD‐Systeme entwickelt, realisiert und anhand von technischen Substraten (Metall, Glas, Kunststoffe) auf ihre Funktionstüchtigkeit überprüft. Hierzu wurde eine Versuchsanlage aufgebaut, an welcher die Möglichkeiten des Verfahrens demonstriert werden können und welche Interessenten für Versuche zur Verfügung steht. Im Vergleich mit dem Pyrosil®‐Verfahren konnten gleiche und bessere Ergebnisse erzielt werden.
Quantitative or semi‐quantitative?–laboratory‐based WD‐XRF versus portable ED‐XRF spectrometer: results obtained from measurements on nickel‐base alloys
Authors: Zwicky Christoph N. , Lienemann Peter
Published: April 2004

‘Semi‐quantitative’ analytical procedures are becoming more and more popular. Using such procedures, the question of the accuracy of results arises. The accuracy of an analytical procedure depends to a great extent on spectral resolution, counting statistics and matrix correction. Two ‘semi‐quantitative’ procedures are compared with a quantitative analytical program. Using a laboratory‐based wavelength‐dispersive x‐ray fluorescence (WD‐XRF) spectrometer and a portable energy‐dispersive x‐ray fluorescence (ED‐XRF) spectrometer, 28 different nickel‐base alloy Certified Reference Materials (CRMs) were analyzed. Line interferences and inaccurate matrix correction are reasons for deviations from the reference value. As the comparison shows, ‘semi‐quantitative’ analyses on the WD‐XRF spectrometer can be accepted as quantitative determinations. The investigations show that the results obtained with the portable ED‐XRF spectrometer do not meet the quality requirements of laboratory analysis, but they are good enough for field investigations. Copyright © 2004 John Wiley & Sons, Ltd.
On the Replicability of the Affective Priming Effect in the Pronunciation Task
Authors: Spruyt Adriaan , Hermans Dirk , Pandelaere Mario , De Houwer Jan , Eelen Paul
Published: April 2004

Abstract. Bargh, Chaiken, Raymond, and Hymes (1996 ) and Hermans, De Houwer, and Eelen (1994 ) showed that a valenced target word is pronounced faster after the presentation of an affectively related prime word than after the presentation of an affectively unrelated prime word. This finding is important because it provides crucial evidence for the hypotheses that stimulus evaluation (a) is goal-independent and (b) facilitates the encoding of stimuli that have the same valence. However, recent studies indicate that the affective priming effect is not a reliable finding in the standard pronunciation task. We report the results of a nearly exact replication of Bargh et al.’s (1996 ) Experiment 2. In line with previous replication studies, we failed to detect the affective priming effect.
Outcome Value and Early Warning Indications as Determinants of Willingness to Learn from Experience
Authors: Zakay Dan , Ellis Shmuel , Shevalsky Morit
Published: April 2004

Abstract. In this study of willingness to learn from experience, it was hypothesized that managers would show a negative outcome bias, that is, a stronger tendency to initiate “learning-from-experience” processes after negative outcomes than after positive outcomes. Another aim of the study was to explore the impact of the existence of early warning signals about decision outcomes on the magnitude of the negative outcome bias. Eighty-three managers were asked to read vignettes describing a managerial decision and its outcomes. The outcomes were either positive or negative, and in half of the cases early warning signals existed that made it possible to predict potential negative outcomes while in the other half there were no such signals. The managers were asked to evaluate the need for a learning-from-experience process in general and to rate the degree to which several specific learning processes should be instituted in each of the scenarios. As hypothesized, a negative-outcome bias was found. The more negative the outcomes described, the stronger the managers’ inclination to recommend a more intensive learning process. Similarly, a need to ensure control and follow-up procedures was reported mostly after negative outcomes. The existence of early warning signals before the decision was taken did not influence the motivation to learn. Theoretical implications regarding the impact of negative outcomes in general and implications for understanding learning from experience processes in particular are discussed.
Sequential Modulations of Logical-Recoding Operations in the Simon Task
Authors: Wühr Peter
Published: April 2004

Abstract. The Simon effect consists of faster responses to the color (or another nonspatial feature) of spatially corresponding stimuli than to spatially noncorresponding stimuli. Recently, several studies observed the Simon effect after corresponding predecessor trials, but not after noncorresponding predecessor trials. To explain these sequential modulations, Stürmer et al. (2002 ) proposed a mechanism modulating the ability of stimulus position to automatically activate a response. The present study investigated which events are effectively triggering this mechanism in a variant of the Simon task, in which both stimuli and responses varied in color (participants wore colored gloves) as well as in horizontal position. In the same-color task (e.g., green stimulus-green response), a normal Simon effect showed up after corresponding trials, but no effect occurred after noncorresponding trials. In the alternate-color task (e.g., green stimulus-red hand), no effect occurred after spatially corresponding trials, whereas an inverted Simon effect was found after noncorresponding trials. Additional analyses showed that repetition (or alternation) effects did not affect the results. The results are discussed in terms of a conflict-monitoring account ( Stürmer et al., 2002 ), and in terms of a feature-integration account ( Hommel et al., 2002 ).
Polar cap index comparisons with AMIE cross polar cap potential, electric field, and polar cap area
Authors: Ridley A. J. , Kihn E. A.
Published: April 2004

The polar cap index (PCI) has been shown to be quite useful as an index of the electrodynamic processes within the high‐latitude ionosphere. Here we use between 150 and 180 magnetometers to model the high‐latitude electrodynamics with the assimilative mapping of ionospheric electrodynamics (AMIE) technique for all of 1997–2001. We compare AMIE calculations of the cross polar cap potential (CPCP), polar cap electric field, and polar cap area to the Northern PCI and the existing PCI‐based relationships for these quantities. We find that the existing PCI estimates underestimate all of the AMIE derived quantities. The PCI is best correlated with the CPCP, while it correlates least with the polar cap electric field. In addition, there is a seasonal effect in the relationship between all AMIE quantities and the PCI. It is most pronounced in the electric field. The polar cap area is shown to have a linear fit in the summer and an asymptotic fit in the winter. These differences indicate that there may be a conductance difference in the techniques. We derive new relationships between the Northern PCI and the AMIE derived polar cap area, CPCP, and polar cap electric field which include the seasonal dependence.
Geosynchronous magnetic field response to solar wind dynamic pressure pulse
Authors: Lee D.‐Y. , Lyons L. R.
Published: April 2004

We present a study of the response of the geosynchronous magnetic field to abrupt enhancements of the solar wind dynamic pressure. Results are obtained separately for cases of northward and southward interplanetary magnetic field (IMF) prior to and after the solar wind pressure jump. For pressure enhancements with southward IMF we find that the response of the geosynchronous magnetic field on the dayside is mostly compression. However, on the nightside it can be a dipolarization‐like change that is similar to that which occurs during substorms. We report four events showing the dipolarization‐like response on the nightside. Analysis using low‐latitude geomagnetic data as well as the geosynchronous energetic particle flux data leads us to argue that this dipolarization is part of the global disturbance directly driven by the solar wind pressure enhancement. We also find that the nightside magnetosphere is remarkably sensitive to small solar wind dynamic pressure enhancements when the IMF is strongly southward (i.e., Bz is below ∼−10 nT). For northward IMF, solar wind pressure enhancements generally lead to magnetic compression, with a few cases of depression on the nightside, neither of which is a dipolarization‐like response. The compression is strongest near noon, decreases toward dawn and dusk, and increases with the amount of increase in dynamic pressure.