bluuebunny/crossref_metadata_2025 huggingface dataset:
Screening of acrylamide contents in potato crisps using process variable settings and near‐infrared spectroscopy
Authors: Segtnan Vegard H. , Kita Agnieszka , Mielnik Maria , Jørgensen Kjetil , Knutsen Svein Halvor
Published: August 2006

In order to study the formation of acrylamide in potato crisps during processing, an experimental design was set up. The design variables were drying time (6 levels), frying temperature (2 levels) and frying time (8 levels). The design contained 36 samples, which were analysed for acrylamide contents using LC high‐resolution mass spectroscopy (LC‐HRMS), and fat contents using the Soxhlet apparatus. Prior to analysis, all potato crisp samples were ground and analysed on an NIRSystems 6500 near‐infrared (NIR) spectrometer. The acrylamide contents were modelled by: (i) design variables using multiple linear regression, (ii) NIR spectra using partial least squares regression (PLSR) and (iii) design variables and NIR spectra in combination using a novel technique combining least squares regression on the former, and PLSR on the latter. The results showed that the NIR spectra alone or in combination with the design variables gave better prediction models for acrylamide than the design variables alone. This implies that the spectra contain chemical information that is not purely a result of the processing variables that were investigated in this experiment. NIR spectroscopy is proposed as a possible tool for screening and identification of potato crisps with a high acrylamide content.
Relations between relative mRNA abundance and developmental competence of ovine oocytes
Authors: Leoni G.G. , Bebbere D. , Succu S. , Berlinguer F. , Mossa F. , Galioto M. , Bogliolo L. , Ledda S. , Naitana S.
Published: August 2006

The present study was conducted to investigate the relation between in vitro developmental competence and the expression of a panel of developmentally important genes in germinal vesicle (GV) stage oocytes. One‐month‐old prepubertal and adult sheep oocytes were used as models of low and high quality gametes, respectively. Cumulus‐oocyte complexes (COCs) derived from lambs and ewes were in vitro matured and fertilized, and their cleavage rate at 22, 26, and 32 hr post fertilization and the blastocyst yield were observed to assess their developmental potential. In parallel, the relative abundance (RA) of 11 genes was analyzed by semi‐quantitative Reverse Transcription Polymerase Chain Reaction (RT‐PCR) assay in the two groups of oocytes. We observed similar maturation and fertilization rates in the two groups, but a significant lower rate of cleaved prepubertal oocytes (P < 0.05), a general delay in the timing of their first division (P < 0.01), and a lower blastocysts production (P < 0.05). The analysis of gene expression evidenced no difference in the RA of four transcripts [superoxide dismutase (SOD), ubiquitin, β‐actin, cyclin B] in the two classes of oocytes, but a statistically lower RA of seven messenger RNAs (mRNA) [Na+K+ATPase, p34cdc2, Glucose‐transporter I (Glut‐1), Activin, Zona Occludens Protein 2 (PanZO2), Poli(A)Polymerase (PAP), E‐Cadherin (E‐Cad)] in the prepubertal oocytes compared to the adult ones. The present data show for the first time in the ovine species that the lower developmental competence is associated with deficiencies in the mRNAs storage during the oocyte growth. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Glycogen synthase kinase‐3 regulation of chromatin segregation and cytokinesis in mouse preimplantation embryos
Authors: Acevedo Nicole , Wang Xia , Dunn Rodney L. , Smith Gary D.
Published: August 2006

Glycogen synthase kinase‐3 (GSK‐3) is a highly conserved serine/threonine protein kinase implicated in diverse cellular processes. Activity of GSK‐3 is essential for meiotic chromatin segregation in oocytes, yet expression and/or function of GSK‐3 have not been reported in mammalian preimplantation embryos. Objectives of this study were to characterize GSK‐3 protein expression/phosphorylation in mouse preimplantation embryos, to assess the effect of GSK‐3 activity inhibition on early mitotic events, and to differentiate nuclear and cytoplasmic anomalies in GSK‐3 inhibited embryos. Both GSK‐3 isoforms were expressed during embryo development, with a differential expression of α versus β. Phosphorylation of GSK‐3α/β at residues Y279/Y216 indicated constitutive activation throughout preimplantation development. Phosphorylation at N‐terminal residues S21/S9 indicated inhibition of GSK‐3α/β activity that was differentially regulated during early development; both α and β isoforms were phosphorylated during early divisions, whereas at the blastocyst stage, only β was phosphorylated. Cytoplasmic microinjection of zygotes with anti‐GSK‐3α/β antibody significantly compromised embryonic development past the two‐cell stage compared to controls. Reversibility of developmental block was tested via pharmacological inhibitors of GSK‐3, lithium chloride (LiCl) and alsterpaullone. Similar to immunoneutralization, significantly fewer zygotes cultured with either LiCl or alsterpaullone developed past the two‐cell stage compared to controls and this mitotic block was not reversible. Inhibition of GSK‐3 activity significantly compromised timing of pronuclear membrane breakdown and mitosis initiation, nuclear development, and cytokinesis. Inhibition of GSK‐3 also resulted in abnormal chromatin segregation, evidenced by incomplete karyokinesis and micronuclei formation. These results suggest that GSK‐3 activity is critical for early preimplantation embryonic development. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.
Activation of ribosomal RNA genes in porcine embryos produced in vitro or by somatic cell nuclear transfer
Authors: Bjerregaard Bolette , Pedersen Hanne G. , Jakobsen Anne S. , Rickords Lee F. , Lai Liangxue , Cheong Hee‐Tae , Samuel Melissa , Prather Randall S. , Strejcek Frantisek , Rasmussen Zaida R. , Laurincik Jozef , Niemann Heiner , Maddox‐Hyttel Poul , Thomsen Preben D.
Published: August 2006

The onset of ribosomal RNA (rRNA) synthesis occurs during the second half of the third cell cycle, that is, at the four‐cell stage, in porcine embryos developed in vivo. In the present study the onset of rRNA synthesis was investigated in porcine embryos produced in vitro (IVP) or by somatic cell nuclear transfer (SCNT) using fluorescence in situ hybridization (FISH) with an rDNA probe and subsequent visualization of the nucleolar proteins by silver staining. In the 205 IVP embryos investigated, all two‐cell embryos (n = 34) were categorized as transcriptionally inactive. At the late four‐cell stage (n = 45), 38% of the embryos contained 1–3 nuclei with signs of rRNA transcription, indicating an asynchronous transcription initiation. This pattern continued in the following stages, as 78% (n = 47), 47% (n = 42) and 83% (n = 37) of the embryos revealed a mixture of transcriptionally inactive and active cells at the eight‐cell, 16‐cell and blastocyst stage, respectively. In the 143 SCNT embryos investigated, all two‐cell embryos (n = 34) and early four‐cell embryos (n = 12) were also transcriptionally inactive. At the late four‐cell stage (n = 33) and at the eight‐cell stage (n = 24) there were equal proportions of transcriptionally active and inactive embryos and essentially all embryos that developed to the 16‐cell stage (n = 21) and further to the blastocyst stage (n = 19) contained only transcriptionally active cells. In conclusion, porcine embryos produced in vitro had an asynchronous pattern of rRNA transcription initiation when compared to SCNT and in vivo developed porcine embryos. Mol. Reprod. Dev. 74: 35–41, 2007. © 2006 Wiley‐Liss, Inc.
Gene expression in bovine nuclear transfer embryos in relation to donor cell efficiency in producing live offspring
Authors: Beyhan Z. , Forsberg E.J. , Eilertsen K.J. , Kent‐First M. , First N.L.
Published: August 2006

Developmental abnormalities associated with the cloning process suggest that reprogramming of donor nuclei into an embryonic state may not be fully completed in most of the cloned animals. One of the areas of interest in this regard, is the analysis of gene expression patterns in nuclear transfer (NT) embryos to dissect the processes that failed and develop means to overcome the limitations imposed by these factors. In this study, we investigated expression patterns of histone deacetylase‐1, ‐2, ‐3 (HDAC‐1, ‐2, ‐3), DNA methyltransferase‐3a (DNMT3A), and octamer binding protein‐4 gene (OCT4) in donor cells with different cloning efficiencies and NT embryos derived from these cells employing a real‐time RT‐PCR assay. All genes investigated followed altered expression patterns in NT embryos when compared to IVF‐derived embryos. In general, expression of HDAC genes was elevated especially at the compact morula stage and comparable to in vitro fertilized (IVF) embryos at the hatched blastocyst stage. DNMT3A expression in NT embryos was lower than IVF embryos at all stages. Oct‐4 transcript levels were also reduced in cloned compared to IVF embryos at the compact morula and blastocyst stages. This difference disappeared at the hatched blastocyst stage. There was a donor cell effect on the expression patterns of all genes investigated. These results demonstrate altered gene expression patterns for certain genes, in cloned cattle embryos from our donor cells of different efficiency in producing live offspring. Therefore we suggest that differences in expression of developmentally important genes during early embryo development may characterize the efficiency of donor cells in producing live offspring. Mol. Reprod. Dev. 74: 18–27, 2007. © 2006 Wiley‐Liss, Inc.
Bone mineral densities in the prehistoric, Viking‐Age and medieval populations of Norway
Authors: Holck Per
Published: August 2006

Osteoporosis is a prevalent condition in Norway, as evidenced by the fact that this country has the highest reported incidences of hip and distal forearm fractures. Because recent studies suggest a higher bone density in rural populations compared with urban ones, increased physical activity is believed to be an important factor in reducing fracture incidence. In the present investigation, 185 femoral necks from the Schreiner Collection in Oslo were measured by means of a bone‐mass scanner. The bones, anthropological specimens ranging from the Stone Age to the Middle Ages, were separated into three groups: prehistoric (n = 36), Viking Age (n = 38) and medieval (n = 111). The medieval group was further separated into urban, rural and monastic populations. The examination showed that: (a) there was no significant difference at a 5% level in average bone mineral density (BMD) between the male and female material; (b) there was no significant difference in average BMD among the prehistoric, Viking Age, and medieval periods (P = 0.151); (c) there was no significant difference in average BMD between the rural and urban medieval material; (d) there was a significant difference in average BMD only between the monastic and the rural medieval material; (e) only the medieval material showed a significantly higher average BMD than that of today (P = 0.001). These findings may indicate that factors in addition to physical activity are important for normal BMD maintenance. Copyright © 2006 John Wiley & Sons, Ltd.
Use of phenytoin, phenobarbital, or diazepam during pregnancy and risk of congenital abnormalities: a case‐time‐control study
Authors: Kjær Dorte , Horvath‐Puhó Erzsébet , Christensen Jakob , Vestergaard Mogens , Czeizel Andrew E. , Sørensen Henrik Toft , Olsen Jørn
Published: August 2006

Purpose

Case‐control studies are often used to examine putative teratogenic drug effects during organogenesis but these studies are subject to confounding by indication, recall, and participation bias. The case‐time‐control approach is less susceptible to these sources of bias. We studied congenital abnormalities following exposure to phenytoin, phenobarbital, and diazepam in early pregnancy, i.e., second and third month, compared to mid‐pregnancy, i.e., fifth and sixth month of pregnancy.

Methods

We analyzed data from the Hungarian Case‐Control Surveillance of Congenital Abnormalities (1980–1996) in a case‐time‐control study.

Results

The study included 22 843 children with congenital abnormalities (cases) and 38 151 children with no abnormalities (controls). Overall, odds ratio (OR) for congenital abnormalities after exposure to one of the three drugs in early pregnancy was 1.2 (95% confidence interval (CI): 1.0–1.4). Among children exposed to phenytoin OR for congenital abnormalities was 3.7 (95%CI: 0.3–49.6), for children exposed to phenobarbital the OR was 1.1 (95%CI 0.7–1.7), and for diazepam, OR for congenital abnormalities was 1.2 (95%CI: 1.0–1.4).

Conclusions

The associations we found between the drugs examined and congenital abnormalities were either only borderline significant or not statistically significant. The case‐time‐control study provides an interesting way of using existing case‐control data to study rare side effect of drugs taken during pregnancy. Copyright © 2006 John Wiley & Sons, Ltd.
Turbulenzübergang in der Rohrströmung: Die Lösung eines alten Rätsels
Authors: Eckhardt Bruno , Hof Björn , Faisst Holger
Published: August 2006

Die Strömung von Flüssigkeiten und Gasen durch eine Röhre kann zwei Zustände annehmen. Einer ist laminar, also gleichmäßig geordnet, einer ist zeitlich‐räumlich verwirbelt und turbulent. Mit dem Übergang zur Turbulenz nimmt der Strömungswiderstand drastisch zu. Vor etwa 120 Jahren beschrieb Osborne Reynolds bereits das Verhalten der Rohrströmung sehr genau. Er beobachtete, dass der Turbulenzübergang sehr empfindlich von äußeren Störungen abhängt, was bislang rätselhaft blieb. Dieses Rätsel konnte nun mit einer Kombination aus Computerstudien, Konzepten aus der nichtlinearen Dynamik und speziell entwickelten Experimenten gelöst werden.
Ein Regenbogen ohne Regentropfen: Spielwiese
Authors: Schlichting Hans Joachim
Published: August 2006

Wenn Licht unter geeignetem Winkel auf eine quaderförmige mit Wasser gefüllte Wanne trifft, wirken die Lichtbrechungen beim Eintritt in die Wanne und beim Austritt so zusammen, dass ein bogenförmiges Band spektral zerlegten Lichts auf einer Projektionswand entsteht. Steht die Wanne mitten auf einem Overheadprojektor, so findet das Licht an allen Seitenflächen ähnliche Bedingungen vor. Unter Umständen sind dann an allen vier Wänden des Raumes “Regenbögen” zu sehen. Dieses Freihandexperiment, das ohne Aufwand realisiert werden kann, beeindruckt vor allem in großen Räumen.
Nanomagnetische Eigenschaften im Elektronenmikroskop
Authors: Schattschneider Peter
Published: August 2006

Magnetische Festkörper besitzen die Eigenschaft des Zirkulardichroismus, das heißt ihr Absorptionsgrad für Röntgenstrahlung hängt von der zirkularen Polarisation ab. Synchrotronstrahlung eignet sich ausgezeichnet, um mit Hilfe dieses Effekts magnetische Eigenschaften zu untersuchen. Sie ist aber teuer, und die Ortsauflösung ist meist nicht besser als 50 nm. Jetzt gelang es einer internationalen Forschergruppe, Zirkulardichroismus mit einem handelsüblichen Elektronenmikroskop nachzuweisen. Damit könnte eine neue, billige Untersuchungstechnik für Nanomagnetismus begründet werden.
Speicherscheibe für 300 Gigabyte
Authors: Wengenmayr Roland
Published: August 2006

Die optisch‐digitalen Datenspeicher CD und DVD haben unsere Lebensgewohnheiten stark verändert. Schon sind die Nachfolgesysteme Blue Ray Disk und HD‐DVD in einigen Ländern auf dem Markt. In den USA wird noch in diesem Jahr das Unternehmen InPhase Technologies in Longmond, Colorado, das erste holografische Datenspeichersystem herausbringen.
Der Lichtpfeil, der einen Tropfen durchbohrt
Authors: Schlichting Hans Joachim
Published: August 2006

Betrachtet man Wassertropfen oder Glaskugeln in der Sonne, so kann man den Eindruck gewinnen, ein Lichtstrahl würde die Kugel geradezu durchbohren. Gleichzeitig meint man, Eintritts‐ und Austrittsöffnung zu erkennen.
Morphology and interactions of polymer brush‐coated spheres in a polymer matrix
Authors: Xu Jiajing , Qiu Feng , Zhang Hongdong , Yang Yuliang
Published: August 2006

Using a real space implementation of the self‐consistent field theory, we calculated the morphology and interactions of spherical nanoparticles with radius Rp that are grafted by polymer chains of N monomers immersed in a chemically identical polymer melt of polymerization index P. The calculation shows that, for big particles (Rp ≫ N1/2a, with a the segment size), the interactions and density profiles of the grafted layers are that of brushes at flat interface; While for small particles (Rp ≪ N1/2a), the interactions and density profiles are characteristic of star polymers. In the case of intermediate grafted chain lengths, that is, Rp ∼ N1/2a, we found that the grafting density of the polymers and the radius of the spherical nanoparticles are both important in determining the structure and interactions of the grafted layers. Our findings suggest possible ways to tailor the structure and interactions of the nanoparticles to benefit the fabrication of polymeric nanocomposites. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2811–2820, 2006
Electrospun fiber mats of poly(3‐hydroxybutyrate), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate), and their blends
Authors: Sombatmankhong Korakot , Suwantong Orawan , Waleetorncheepsawat Suchada , Supaphol Pitt
Published: August 2006

Electrospinning of poly(3‐hydroxybutyrate) (PHB), poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) (PHBV), and their blends was first carried out in chloroform at 50 °C on a stationary collector. The average diameter of the as‐spun fiber from PHB and PHBV solutions decreased with increasing collection distance and increased with increasing solution concentration and applied electrical potential. In all of the spinning conditions investigated, the average diameter of the as‐spun pure fibers ranged between 1.6 and 8.8 μm. Electrospinning of PHB, PHBV, and their blends was carried out further at a fixed solution concentration of 14% w/v on a homemade rotating cylindrical collector. Well‐aligned, cross‐sectionally round fibers without beads were obtained. The average diameter of the as‐spun pure and blend fibers ranged between 2.3 and 4.0 μm. The as‐spun fiber mats appeared to be more hydrophobic than the corresponding films and much improvement in the tensile strength and the elongation at break was observed for the blend fiber mats over those of the pure fiber ones. Lastly, indirect cytotoxicity evaluation of the as‐spun pure and blend fiber mats with mouse fibroblasts (L929) indicated that these mats posed no threat to the cells. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2923–2933, 2006
Conformational structures and thermodynamic properties of compact polymer chains confined between two parallel plane boundaries
Authors: Li Shi‐Ben , Zhang Lin‐Xi
Published: August 2006

In this paper, the authors investigated the adsorption phenomenon of compact chains confined between two parallel plane boundaries using a pruned‐enriched Rosenbluth method. The authors considered three cases with different adsorption energies of ε = 0, −1, and −3 (in units of kBT) for the confined compact chains of different chain lengths N, respectively. Several parameters were employed to describe the size and shape of compact chain, and some special behaviors in the conformational structures were investigated for the first time. For example, the size and shape of confined compact chains undergo distinct changes in the adsorption cases of ε = −1 and −3, and pass through the maximum values at the characteristic distances Dc. The authors found that this characteristic distance Dc could be scaled as Dc∼ (N + 1)ν (ν = 0.56 ± 0.01) in the case of ε = −3. In addition, the microstructures of chains were investigated, and several significant results were obtained by analyzing the segment density distribution and the mean fractions of segment in tails, trains, bridges, and loops structures. On the other hand, the thermodynamic properties were also investigated for the confined compact chains, such as average energy per bond, Helmholtz free energy per bond, and elastic force per bond. Results show that elastic forces f have different behaviors in three cases, indicating that it is not necessary to exert an external force on the boundaries in the nonadsorption case. At the same time, the average contact energy of compact chain obviously changes when the distance between the two parallel boundaries D increases, which is similar to those of the size and shape parameters. The authors also conclude that these thermodynamic properties of compact chains depend strongly on not only the adsorption energies but also the chain lengths and the confined condition. In addition, several results of the conformational and thermodynamic parameters, such as the segment density distribution and free energy, were compared with the results from the self‐consistent field theory. These investigations may help us to deepen the knowledge about the adsorption phenomenon of confined compact chains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2888–2901, 2006
Monte Carlo simulation of diffusion effects on chain‐extension reactions
Authors: Yan Li‐Tang , Guo Bao‐Hua , Xu Jun , Xie Xu‐Ming
Published: August 2006

The diffusion effects on chain‐extension reactions using carboxyl‐terminated polyamide‐12 as a model reactant with bisoxazolines were investigated by the stochastic Monte Carlo method. Thus, complicated direct modeling and numerical calculations were avoided. The chain‐length dependence and detailed diffusive behavior were discussed in depth. The diffusion effects retarded the progress of chain‐extension reactions and led to lower coupling efficiency. The simulated results indicated that the diffusion effects could make the final molecular weight distributions wider. In the presence of diffusion and with the progress of the coupling efficiency, peaks in the evolution curves of the weight‐average molecular weight and valleys in the evolution curves of the polydispersity index were observed, respectively, when the coupling efficiency was low enough. These phenomena were different from those without diffusion effects and were analyzed in detail. The critical entanglement chain length had strong effects on the simulated results of the diffusion effects, especially when its value was near the average chain length. The results also showed that the effects of the reactant degradation made the molecular weight distribution of the reaction system wider and weakened the diffusion effects on the coupling reaction. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2902–2911, 2006
How inaccuracies in protein structure models affect estimates of protein–ligand interactions: Computational analysis of HIV‐I protease inhibitor binding
Authors: Thorsteinsdottir Holmfridur B. , Schwede Torsten , Zoete Vincent , Meuwly Markus
Published: August 2006

The influence of possible inaccuracies that can arise during homology modeling of protein structures used for ligand binding studies were investigated with the molecular mechanics generalized Born surface area (MM‐GBSA) method. For this, a family of well‐characterized HIV‐I protease–inhibitor complexes was used. Validation of MM‐GBSA led to a correlation coefficient ranging from 0.72 to 0.93 between calculated and experimental binding free energies ΔG. All calculated ΔG values were based on molecular dynamics simulations with explicit solvent. Errors introduced into the protein structure through misplacement of side‐chains during rotamer modeling led to a correlation coefficient between ΔGcalc and ΔGexp of 0.75 compared with 0.90 for the correctly placed side chains. This is in contrast to homology models for members of the retroviral protease family with template structures ranging in sequence identity between 32% and 51%. For these protein models, the correlation coefficients vary between 0.84 and 0.87, which is considerably closer to the original protein (0.90). It is concluded that HIV‐I low sequence identity with the template structure still allows creating sufficiently reliable homology models to be used for ligand‐binding studies, although placement of the rotamers is a critical step during the modeling. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Describing and projecting the age and spatial structures of interregional migration in Italy
Authors: Raymer James , Bonaguidi Alberto , Valentini Alessandro
Published: August 2006

A multiplicative component model is applied in this paper to present a simple, yet powerful, framework for analysing and projecting internal migration flows. The multiplicative components are useful for identifying important underlying structures in the migration patterns. To demonstrate, seven periods of age‐specific interregional migration in Italy (1970–1971 to 2000–2001) are analysed. This information is then used to project the age and spatial structures forward to the 2010–2011 period. The projection model focuses on the underlying structures, which allows both the stable and changing aspects of the migration patterns to be included. Copyright © 2006 John Wiley & Sons, Ltd.
Blacks and Hispanics in urban America: similar patterns of residential segregation?
Authors: Johnston Ron , Poulsen Michael , Forrest James
Published: August 2006

Studies of residential segregation of Blacks and Hispanics in United States' metropolitan areas over recent decades have suggested a convergence between the two groups, as Black segregation levels declined somewhat, whilst those for Hispanics have increased substantially. The latter has been associated with the rapid and very substantial growth in the Hispanic population. To some considerable extent, those changes have been taking place in different parts of the US. Many of the metropolitan areas experiencing major increases in their Hispanic populations contain relatively few Blacks; and the changes have varied considerably across the country. So are similar processes in operation? Are the same characteristics associated with high levels of segregation for each ethnic group? Regression analyses of data for 1980 and 2000, and for changes between those two dates, suggest that they are: that the size of a minority group – both absolute and as a percentage of the metropolitan population – is significantly linked to segregation levels and changes in them. There is clear convergence taking place, reflecting increasing segregation among recently‐arrived Hispanics and some desegregation among Blacks. This is consistent with general models of residential segregation, even if they are occurring in different parts of the country. Copyright © 2006 John Wiley & Sons, Ltd.
Prediction of ITQ‐21 Zeolite Phase Crystallinity: ParametricVersusNon‐parametric Strategies
Authors: Baumes Laurent A. , Moliner Manuel , Corma Avelino
Published: August 2006

This work deals with data analysis techniques and high‐throughput tools for synthesis and characterization of solid materials. In previous studies, it was found that the final properties of materials could be successfully modeled using learning systems. Machine learning algorithms such as neural networks, support vector machines, and regression trees are non‐parametric strategies. They are compared to traditional parametric statistical approaches. We review a wide range of statistical methodologies, and all the methods are evaluated using experimental data derived from an exploration‐optimization of the material ITQ‐21. The results are judged on the numerical prediction of phase's crystallinity. We discuss the theoretical aspects of such statistical techniques, which make them an attractive method when compared to other learning strategies for modeling the properties of the solids. Advantages and drawbacks are highlighted. We show that such approaches, by offering broad solutions, can reach high‐level performances while offering ease of use, comprehensibility, and control. Finally, we shed light on both the interpretation and stability of results, which remain the main drawbacks of the majority of machine learning methodologies when trying to retrieve knowledge from the data treatment.
Using QSPR Models to Predict the Enthalpy of Vaporization of 209 Polychlorinated Biphenyl Congeners
Authors: Padmanabhan Jaganathan , Parthasarathi Ramakrishnan , Subramanian Venkatesan , Chattaraj Pratim K.
Published: August 2006

Quantitative Structure–Property Relationship (QSPR) models to correlate the vaporization enthalpies (ΔvapHm) of a set containing biphenyl and 16/26 Polychlorinated Biphenyls (PCBs) with their conceptual Density Functional Theory (DFT)‐based global reactivity parameter such as electrophilicity index (ω) along with the energy of lowest unoccupied molecular orbital (ELUMO) and the number of chlorine substituents (NCl) as descriptors are presented. A good coefficient of determination (r2=0.976/0.858) and internal predictive ability ($\rm{ r_{{\rm{cv}}}^2 }$=0.948/0.758) values are obtained indicating the significance of the considered descriptors in the property analysis. The developed model is used to predict ΔvapHm of the remaining 193/183 PCB congeners.
Peptide derivatization as a strategy to form fixed‐charge peptide radicals
Authors: Karnezis Asimo , Barlow Christopher K. , O'Hair Richard A. J. , McFadyen W. David
Published: August 2006

As a means of generating fixed‐charge peptide radicals in the gas phase we have examined the collision‐induced dissociation (CID) chemistry of ternary [CuII(terpy)(TMPP‐M)]2+ complexes, where terpy = 2,2′:6′2″‐terpyridine and TMPP‐M represents a peptide (M) modified by conversion of the N‐terminal amine to a [tris(2,4,6‐trimethoxyphenyl)phosphonium]acetamide (TMPP‐) fixed‐charge derivative. The following modified peptides were examined: oligoglycines, (Gly)n (n = 1–5), alanylglycine, glycylalanine, dialanine, trialanine and leucine‐enkephaline (YGGFL). The [CuII(terpy)(TMPP‐M)]2+ complexes are readily formed upon electrospray ionization (ESI) of a mixture of derivatized peptide and [CuII(terpy)(NO3)2] and generally fragment to form transient peptide radical cations, TMPP‐M+., which undergo rapid decarboxylation for the simple aliphatic peptides. This is contrasted with the complexes containing the unmodified peptides, which predominantly undergo fragmentation of the coordinated peptide. These differences demonstrate the importance of proton mobility in directing fragmentation of ternary copper(II) peptide complexes. In the case of leucine‐enkephaline, a sufficient yield of the radical cation was obtained to allow further CID. The TMPP‐YGGFL+. ion showed a rich fragmentation chemistry, including CO2 loss, side‐chain losses of an isopropyl radical, 2‐methylpropene and p‐quinomethide, and *a1 and *a4 sequence ion formation. In contrast, the even‐electron TMPP‐YGGFL+ ion fragments to form *an and *bn sequence ions as well as the [*b4 + H2O]+ rearrangement ion. Copyright © 2006 John Wiley & Sons, Ltd.
Fragmentation study of hexanitrostilbene by ion trap multiple mass spectrometry and analysis by liquid chromatography/mass spectrometry
Authors: Fu Xiaofang , Zhang Yong , Shi Shenhua , Gao Fei , Wen Dawei , Li Wei , Liao Yiping , Liu Huwei
Published: August 2006

The fragmentation pathways of three explosive compounds with similar structures, hexanitrostilbene (HNS), cyclotrimethylene trinitramine (RDX), and 2,4,6‐trinitrotoluene (TNT), have been investigated by multiple mass spectrometry (MSn, n = 1, 2, 3) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) sources. The electron capture mechanism for these compounds in negative ion APCI and ESI mode differs from the usual negative ion mechanism, deprotonation or addition of other species. This was shown for HNS and TNT, which both gave a [M]− anion but not a [M–H]− ion in APCI, and the [M]− anion of HNS was observed in ESI. The quantitative analysis of HNS was performed by liquid chromatography (LC)/ESI‐MS, and the results obtained by the internal standard (ISTD) method were compared with those from the external standard (ESTD) method, demonstrating that both quantitation approaches are useful, with good sensitivity, reproducibility and linearity, and ESTD is preferable in routine applications. Copyright © 2006 John Wiley & Sons, Ltd.
Eye‐rollers, risk‐takers, and turn sharks: Target students in a professional science education program
Authors: Martin Sonya N. , Milne Catherine , Scantlebury Kathryn
Published: August 2006

In classrooms from kindergarten to graduate school, researchers have identified target students as students who monopolize material and human resources. Classroom structures that privilege the voice and actions of target students can cause divisive social dynamics that may generate cliques. This study focuses on the emergence of target students, the formation of cliques, and professors' efforts to mediate teacher learning in a Master of Science in Chemistry Education (MSCE) program by structuring the classroom environment to enhance nontarget students' agency. Specifically, we sought to answer the following question: What strategies could help college science professors enact more equitable teaching structures in their classrooms so that target students and cliques become less of an issue in classroom interactions? The implications for professional education programs in science and mathematics include the need for professors to consider the role and contribution of target students to the learning environment, the need to structure an equitable learning environment, and the need to foster critical reflection upon classroom interactions between students and instructors. © 2006 Wiley Periodicals, Inc. J Res Sci Teach 43: 819–851, 2006
Parental Participation in Pediatric Surgical Care
Authors: Kristensson‐Hallström Inger
Published: August 2006

Hospitalization and surgery are stressful experiences for children and their parents. In recent years, pediatric health care has shifted toward family‐centered care that is based on close and continuous involvement of the child's family members. To shape and improve how pediatric care is delivered, health care providers need to know what children and parents need, expect, and experience. Such knowledge would enable the development of appropriate, systematic, and effective routines to optimize care for all children. Parental participation is beneficial to children, parents, and health care facilities, but it is dependent on the existence of effective routines to facilitate adequate communication among all parties. AORN J71 (May 2000) 1021–1029.
Maximizing Nurses' Advocacy Role to Improve Patient Outcomes
Authors: Allen George
Published: August 2006

Perioperative nurses are eminently situated, academically prepared, and professionally qualified to positively affect patient outcomes. Increasing efficiency and justifying the need for an RN in the perioperative milieu revolve around nurses' role as patient advocates. Perioperative nurses can take many measures to maximize this role, including reducing surgical site infections by enabling the timely administration of antimicrobial prophylaxis and by ensuring that surgical staff members realize the documented risks of removing hair from the surgical site. AORN J 71 (May 2000) 1038–1050.
Nurses' Contributions to the US Space Program
Authors: Czerwinski Barbara S. , Plush Linda H. , Bailes Barbara K.
Published: August 2006

Nurses have been engaged in aspects of aviation and space endeavors from their beginnings. Although no nurse has been chosen as a potential astronaut, nurses have contributed to the space program in many ways. Nurses and other health care providers use technology adapted from the space program. The future of extended space flight remains unclear, although work continues on completing a space station for extended stays on the moon and trips to Mars. Nurses may be one of the health care team members on these excursions. AORN J 71 (May 2000) 1051–1057.
Case Manager's Desk Reference
Authors: Davis Janice
Published: August 2006

Case Manager's Desk Reference, Aspen Reference Group, 1999, paperback, 339 pp $69
Management of Sports‐Related Anterior Cruciate Ligament Injuries
Authors: Clasby Laura , Young Mary Ann
Published: August 2006

Injuries from recreational and competitive sports activities have increased significantly during the past two decades. The anterior cruciate ligament (ACL) is one of the most commonly injured knee ligament in athletes. As the ACL is the knee's primary intra‐articular stabilizer, injuries to this ligament can seriously alter athletes' physical activity levels or end their sports careers. The medical and surgical treatment options for a sports‐related ACL injury depend upon the age of the patient, the type and degree of the ACL injury, and the anticipated future activity level of the athlete. This article describes the anatomy and physiology of the knee joint, the different types and degrees of ACL injuries, diagnostic measures for ACL injuries, and treatment options, which include arthroscopically assisted ACL reconstruction procedures with autologous patellar tendon grafts. Preoperative, intraoperative, and postoperative nursing interventions, rehabilitation regimens, and sports injury prevention measures are discussed. AORN J 66 (Oct 1997) 609–630.
Guided Imagery as a Coping Strategy for Perioperative Patients
Authors: Tusek Diane , Church James M. , Fazio Victor W.
Published: August 2006

Patients who undergo surgery usually experience fear and apprehension about their surgical procedures. Guided imagery is a simple, low‐cost therapeutic tool that can help counteract surgical patients' fear and anxiety. The authors randomly assigned 130 patients undergoing elective colorectal surgical procedures into two groups. Members of one group received routine perioperative care. Members of the other group listened to guided imagery tapes for three days before their surgical procedures, during anesthesia induction, intraoperatively, in the postanesthesia care unit, and for six days after surgery. The authors measured patients' anxiety levels, pain perceptions, and narcotic medication requirements. The patients in the guided imagery group experienced considerably less preoperative and postoperative anxiety and pain, and they required almost 50% less narcotic medications after their surgical procedures than patients in the control group. AORN J 66 (Oct 1997) 644–649.
Competency Validation for Cross‐training in Surgical Services
Authors: Masson Laura , Fain James A.
Published: August 2006

Cross‐training is a cost‐effective means of maximizing the potential of staff members and available resources. The responsibility to provide quality patient care should not be compromised by cross‐training efforts. Surgical services department staff members at Deaconess‐Nashoba Hospital, Ayer, Mass, developed a competency validation project for nurses involved in the cross‐training program. They accomplished this by implementing current nursing standards and practices and promoting continuity of patient care through the preoperative, intraoperative, and postoperative phases. Perioperative nurses and health care facilities have the responsibility to provide safe, effective, and efficient care to all patients. By assessing competencles for perioperative nurses, staff members can enhance their commitment to caring for their profession and their communities. AORN J 66 (Oct 1997) 651–659.
Critical Issues in Operating Room Management
Authors: Lawrence Ardene M.
Published: August 2006

CRITICAL ISSUES IN OPERATING ROOM MANAGEMENT Edited by Mark A. Malangoni 1996, 304 pp $69 hardcover
Stereotactic Pallidotomy for Treatment of Parkinson's Disease
Authors: Eller Theodore W. , Dan Dorothy A.
Published: August 2006

There has been a resurgence of interest in surgical treatment of Parkinson's disease in the past five years due to the large number of patients who have medically intractable symptoms and because significant improvements in neuroimaging and stereotactic techniques have made surgical procedures safer and more accurate. Stereotactic pallidotomy procedures allow neurosurgeons to destroy a portion of the globus pallidus, and thereby, decrease patients' muscle rigidity from Parkinson's disease. These surgical procedures primarily involve magnetic resonance‐guided stereotactic targeting and microelectrode recording techniques. To ensure successful patient outcomes, stereotactic pallidotomy procedures require special perioperative nursing interventions discussed in this article. AORN J 65 (May 1997) 903–916.
The Nurse's Role in Bioethics
Authors: Beerman Christine M.
Published: August 2006

Hospital ethics committees consist of representatives from multiple disciplines who discuss potential issues and real‐life ethical dilemmas that confront patients, their family members, and the health care professionals involved in patient care. Bioethical issues may provoke strong emotional responses from ethics committee members. Recognizing the difficulty of resolving issues that address moral beliefs is imperative. Nurses are in key positions to help health care professionals navigate these troublesome ethical waters. AORN J 65 (May 1997) 923–926.
The Lay Perspective in Health Technology Assessment
Authors: McConnell Edwina A.
Published: August 2006

The Lay Perspective in Health Technology Assessment, BN Ong, International Journal of Technology Assessment in Health Care, 12, 3, 1996, 511–517
Purpose of Family Photographs Displayed in the Pediatric Intensive Care Unit
Authors: Sapnas Kathryn G.
Published: August 2006

Purpose of Family Photographs Displayed in the Pediatric Intensive Care Unit, AJ Macnab, Heart & Lung, 26, January/February 1997, 68–75
Lifebeats
Authors: Skelton Milha K.
Published: August 2006

LIFEBEATS By Linda Strangio 1996, 165 pp $12.95 paperback
Malignant Hyperthermia
Authors: Dunn Debra
Published: August 2006

Malignant hyperthermia (MH) is a medical emergency that all perioperative nurses should be prepared to handle. Patients with the inherited MH trait have a rare skeletal muscle disease that causes them to develop life‐threatening hyperthermia (ie, body temperatures of 43.3° C [110.0° F] or higher) at the time MH‐triggering agents are administered to induce general anesthesia or shortly thereafter. The incidence of MH episodes is reported to be 1 in every 12,000 pediatric anesthetic procedures and 1 in every 40,000 adult anesthetic procedures. The MH syndrome also is characterized by continuous skeletal muscle rigidity, hypermetabolism, hypercapnia, tachypnea, and tachycardia that result in cardiac arrest and death if left untreated. Perioperative staff members' knowledge of MH, the care of MH‐susceptible patients, and adequate preparation for MH crises are the cornerstones of successful patient outcomes to this life‐threatening syndrome. AORN J 65 (April 1997) 728–754.
Determining the Information Needs of Women After Breast Biopsy Procedures
Authors: Deane Karen A. , Degner Lesley F.
Published: August 2006

A focus group research study was conducted at a Canadian community hospital breast clinic to determine information needs of women who had experienced surgical breast biopsy procedures with benign results. Nine breast clinic patients who had benign breast biopsy results provided the researcher with findings related to this experience. The patients determined what they believed were the nine most important information needs during the diagnostic phase of a breast lump evaluation. These information needs emerged from the types of benign breast disease, the meaning of risk associated with benign breast disease developing into breast cancer, and the tests required to diagnose and treat benign breast disease. Perioperative nurses can use this information to plan and assess the care provided to women undergoing breast biopsy procedures. AORN J 65 (April 1997) 767–776.
Building Perioperative Nursing Research Teams—Part II
Authors: Csokasy Judith A.
Published: August 2006

Perioperative nurse managers can use the experiential learning model developed by David A. Kolb, PhD, to develop a team approach to nursing research and to implement research‐based perioperative nursing practice. In this second article of a two‐part series, the author describes the benefits of and barriers to developing nursing research teams and provides an overview of print and electronic resources that perioperative nurse managers can use to facilitate nursing research team members' learning. AORN J 65 (April 1997) 787–790.
The Public's Role in the Evaluation of Health Care Technology: The Conflict Over ECT
Authors: McConnell Edwina A.
Published: August 2006

The Public's Role in the Evaluation of Health Care Technology: The Conflict Over ECT, E Heitman, International Journal of Technology Assessment in Health Care, Vol 12, Fall 1996, 657–672
Implementation of the RN First Assistant Role
Authors: Poe Donna , Bubb Denise Marie , Freeman Laura K.
Published: August 2006

The RN first assistant (RNFA) program at Children's Hospital of The King's Daughters in Norfolk, Va, began as a dream in which RNs could expand their role within a cost‐effective, hospital‐based implementation of the RNFA role. Our dream included a career development path for perioperative nurses who had few other career options within the surgical arena. This article describes how the dream came true. AORN J 65 (Jan 1997) 32–41.
JCAHO Education Standards: From Challenge to Implementation
Authors: Schroeter Kathryn
Published: August 2006

JCAHO Education Standards: From Challenge to Implementation By Vicki Moss, Peggy Camp, Linda Brazen 1996, 97 pp $35 AORN members, $43.75 nonmembers, paperback
Management of Retrohepatic Venous Injuries with Atrial Caval Shunts
Authors: Weber S. , Murphy M.M. , Pitzer M.E. , Davis K.
Published: August 2006

Retrohepatic inferior vena caval injuries resulting from blunt or penetrating abdominal trauma are rare but devastating events that remain formidable challenges to even the most experienced Level I trauma center team members. Prepackaged atrial caval shunts have improved emergency medical treatments, and prior planning and coordination by perioperative nurses allow for rapid response by surgical team members. These efforts provide an optimal level of care required to increase patient survival. This article provides a general overview of abdominal trauma and retrohepatic inferior vena caval injuries and a proactive plan to meet the needs of patients with these injuries.
Perioperative Nursing Care of Patients with Craniofacial Injuries
Authors: Hayes Ketra Marie , Combs Nancy L.
Published: August 2006

Craniofacial injuries are the result of deceleration, blunt, or penetrating trauma. Depending on the mechanism of injury, craniofacial fractures can be minor and go undetected, or they can produce devastating facial deformities. With the advent of intermaxillary fixation devices, surgeons can manipulate facial bone structures and repair soft tissue damage in the majority of patients with craniofacial trauma injuries. Most patients experience optimal results from their craniofacial surgical procedures and return to normal lives after surgery.
Treatment of Conductive Hearing Loss with Ossicular Chain Reconstruction Procedures
Authors: Waddington Carolyn , McKennis Ann T. , Goodlett Ann
Published: August 2006

Middle ear infections and ossicular disorders can cause conductive hearing loss. Ossicular disorders include fibrous unions in which scar tissue replaces the long process of the incus; disarticulations caused by previous surgical procedures or chole‐steatomas; fixation from otosclerosis, cholesteatomas, or congenital malformations; and dislocations caused by trauma. Surgical reconstruction procedures, with the insertion of partial or total ossicular replacement prostheses, help restore conductive hearing. Patients who undergo these delicate procedures have significant hearing deficits and require sensitive, skilled perioperative nursing care. AORN J 65 (March 1997) 511–525.