bluuebunny/crossref_metadata_2025 huggingface dataset:
Demonstration of Techniques and a Suitable Atomizer for Practical Multielement Atomic Absorption Analysis
Authors: Lawson Stephen R. , Nichols John A. , Viswanadham Puligandla , Woodriff Ray
Published: August 2005

Simultaneous multielement atomic absorption spectroscopy has not become a common laboratory workhorse for elemental analyses despite recent advances in instrumentation. Two major obstacles preventing its implementation are the sometimes severe matrix interferences which occur in some pulsed atomizers and the limited working range of atomic absorption spectroscopy compared to the wide linear dynamic range of inductively coupled plasma-atomic emission spectroscopy. Use of a constant temperature furnace in conjuction with techniques such as peak width at fixed height, random dilutions with element rationing, and monitoring two or more wavelengths of different sensitivities of an element are effective methods for eliminating or reducing these obstacles. Determination of trace zinc in unweighed samples of reagent grade CdCl2·2.5H2O and the determination of lead in unknown volumes of blood using hemoglobin iron as the internal standard are examples of analyses performed on the dual channel monochromator used in this work. Problems in selecting appropriate compromise conditions of atomization are exemplified in work done on solid samples. Although full recoveries of Zn and Cd were obtained at 1800 K in biological samples, low recoveries for Zn were obtained in NBS coal fly ash at this temperature. Atomization at 2100 K was necessary to restore full recovery.
Surface Spectroscopic Studies of High-Strength Low-Alloy Steels before and after Annealing
Authors: Graham Susan W. , Hercules David M.
Published: August 2005

Surface analyses of two high-strength low-alloy steels are reported before and after annealing. The surface analysis techniques used include ESCA, AES, and SIMS. The steel samples were hand polished and cleaned before annealing; the effects of cleaning have been investigated. Samples were annealed in flowing N2 or in vacuum at 650°C. Changes in the steel surface as the annealing time and atmosphere were changed are reported. Additionally, differences between surfaces of two steels having similar bulk compositions were investigated both before and after annealing. Cleaning high-strength low-alloy steels generally decreased carbon contamination on the surface without affecting the nature or surface concentrations of iron, oxygen, or manganese. Vacuum annealing the steel produces a steady state much faster than when the steel is nitrogen annealed; however, the composition of the steel surface after vacuum annealing is similar to the surface after annealing in flowing N2. Although the two steels investigated have similar bulk concentrations, type B steel has much higher Mn concentration on the surface than type A steel. The amount of Mn on the surface appears to affect the surface concentrations of Fe and O as the sample is annealed.
Interactions Among DNA Ligase I, the Flap Endonuclease and Proliferating Cell Nuclear Antigen in the Expansion and Contraction of CAG Repeat Tracts in Yeast
Authors: Refsland Eric W , Livingston Dennis M
Published: August 2005

Among replication mutations that destabilize CAG repeat tracts, mutations of RAD27, encoding the flap endonuclease, and CDC9, encoding DNA ligase I, increase the incidence of repeat tract expansions to the greatest extent. Both enzymes bind to proliferating cell nuclear antigen (PCNA). To understand whether weakening their interactions leads to CAG repeat tract expansions, we have employed alleles named rad27-p and cdc9-p that have orthologous alterations in their respective PCNA interaction peptide (PIP) box. Also, we employed the PCNA allele pol30-90, which has changes within its hydrophobic pocket that interact with the PIP box. All three alleles destabilize a long CAG repeat tract and yield more tract contractions than expansions. Combining rad27-p with cdc9-p increases the expansion frequency above the sum of the numbers recorded in the individual mutants. A similar additive increase in tract expansions occurs in the rad27-p pol30-90 double mutant but not in the cdc9-p pol30-90 double mutant. The frequency of contractions rises in all three double mutants to nearly the same extent. These results suggest that PCNA mediates the entry of the flap endonuclease and DNA ligase I into the process of Okazaki fragment joining, and this ordered entry is necessary to prevent CAG repeat tract expansions.
Genetic Basis of Spectral Tuning in the Violet-Sensitive Visual Pigment of African Clawed Frog, Xenopus laevis
Authors: Takahashi Yusuke , Yokoyama Shozo
Published: August 2005

Ultraviolet (UV) and violet vision in vertebrates is mediated by UV and violet visual pigments that absorb light maximally (λmax) at ∼360 and 390–440 nm, respectively. So far, a total of 11 amino acid sites only in transmembrane (TM) helices I–III are known to be involved in the functional differentiation of these short wavelength-sensitive type 1 (SWS1) pigments. Here, we have constructed chimeric pigments between the violet pigment of African clawed frog (Xenopus laevis) and its ancestral UV pigment. The results show that not only are the absorption spectra of these pigments modulated strongly by amino acids in TM I–VII, but also, for unknown reasons, the overall effect of amino acid changes in TM IV–VII on the λmax-shift is abolished. The spectral tuning of the contemporary frog pigment is explained by amino acid replacements F86M, V91I, T93P, V109A, E113D, L116V, and S118T, in which V91I and V109A are previously unknown, increasing the total number of critical amino acid sites that are involved in the spectral tuning of SWS1 pigments in vertebrates to 13.
Ultraviolet B but Not A Radiation Activates Suppressor B Cells in Draining Lymph Nodes
Authors: Byrne Scott N. , Ahmed Jarin , Halliday Gary M.
Published: August 2005

Immunosuppressive doses of solar‐simulated UV radiation activate lymph node B cells that can suppress primary immunity by inhibiting the function of dendritic cells. The aim of this study was to determine the waveband responsible for activation of these suppressor B cells. We exposed C57BL/6 mice to various doses of either UVA or UVB radiation and analyzed the number and activation state of lymph node antigen‐presenting cells (APC). Immunosuppressive doses of UVB but not UVA activated B cells as assessed by major histocompatibility complex II (MHC II) expression and doubled their numbers in draining lymph nodes. Higher doses of UVA that were not immunosuppressive actually suppressed B cell activation. Our results show that UVA and UVB suppress systemic immunity via different mechanisms. Lymph node B cells are activated in response to immunosuppressive doses of UVB but not UVA. Thus, the activation state of lymph node APC appears to be important for UV immunomodulation.
Cover Picture: Ductile‐to‐Brittle Transition in Nanocrystalline Metals (Adv. Mater. 16/2005)
Authors: Li H. , Ebrahimi F.
Published: August 2005

Uniaxial tensile studies concerning electrodeposited nanocrystalline face‐centered cubic Ni and Ni–Fe alloys are reported on p. 1969 by Ebrahimi and Li. The nanograined metals display a transition in the deformation mechanism at a critical grain size. The cover shows that their fracture surfaces exhibited a ductile‐to‐brittle transition from the “cup–cup” (intragranular, ductile failure, dislocation controlled) (top panels) to “cup–cone” (intergranular, brittle fracture, probably due to breaking of atomic bonds) (bottom panels) characteristics at room temperature across this critical grain size value.
No support for association between the dopamine transporter (DAT1) gene and ADHD
Authors: Langley K. , Turic D. , Peirce T.R. , Mills S. , Van Den Bree M.B. , Owen M.J. , O'Donovan M.C. , Thapar A.
Published: August 2005

Several groups have reported an association between the 10‐repeat allele of a dopamine transporter (DAT1) 3′UTR VNTR variant and ADHD but the finding has not been universally observed. An association between DAT1 genotype and stimulant medication response has also been reported although again there are conflicting data. We tested the DAT1 3′VNTR and three SNPs in the putative promoter region of DAT1 for association with ADHD in 263 parent‐proband trios. Analyses of genotypes, alleles, and haplotypes were performed using family‐based association methods. Case‐control analysis of the VNTR in 263 cases and 287 controls was also conducted. In addition, we tested for association between the VNTR marker and stimulant medication response. Comparing allele 10 versus all other alleles combined, no significant association was found with ADHD, using FBAT analysis (χ2 = 0.1 (df 1), P = 0.9, (odds ratio (OR) = 1.0, 95% CI 0.8–1.2), and case‐control analysis (χ2 = 0.12 (df 2), P = 0.91). No evidence of association with any of the SNPs in the promoter region was found. Haplotype analysis was also non‐significant (χ2 = 3.93, (df 9) global P = 0.85). Finally, no association was found between the DAT 1 VNTR and response to stimulant medication (χ2 = 1.63 (df 3) P = 0.65). We conclude that the 3′ VNTR and three additional promoter variants in DAT1 do not appear to be associated with ADHD, or response to stimulant mediation in our sample. © 2005 Wiley‐Liss, Inc.
Transmission disequilibrium and haplotype analyses of the G72/G30 locus: Suggestive linkage to schizophrenia in Palestinian Arabs living in the North of Israel
Authors: Korostishevsky M. , Kremer I. , Kaganovich M. , Cholostoy A. , Murad I. , Muhaheed M. , Bannoura I. , Rietschel M. , Dobrusin M. , Bening‐Abu‐Shach U. , Belmaker R.H. , Maier W. , Ebstein R.P. , Navon Ruth
Published: August 2005

Association of the G72/G30 locus with schizophrenia was recently reported in French Canadian, Russian, and Ashkenazi populations using case‐control studies. In the present study we hypothesize the existence of a G72/G30 risk allele over‐transmitted to affected sibs in Palestinian Arab families. A total of 223 Palestinian Arab families that included an affected offspring and parents were genotyped with 11 SNPs encompassing the G72/G30 genes. The families were recruited from three regions of Israel: 56 from the North (Afula), 136 from the central hill region (Bethlehem, Palestinian Authority), and 31 from the South (Beersheva). Individual SNP analyses disclosed a risk allele in SNP rs3916970 by both haplotype relative risk (HRR: χ2 = 5.59, P = 0.018) and transmission disequilibrium test (TDT: χ2 = 6.03, P = 0.014) in the Afula families. Follow‐up multilocus analysis using family‐based association tests (FBAT: z = 2.197, P = 0.028) exposed the adjacent haplotype. SNP rs3916970 is located about 8 kb from the linkage disequilibrium block that was reported to be associated with schizophrenia in Ashkenazi Jews. Excess of similar haplotypes of this region was observed in the Palestinian Arabs and the Ashkenazi patients. These data suggest a common risk factor for schizophrenia susceptibility in the G72/G30 locus among Ashkenazi Jews and Palestinian Arabs. The results strengthen previous reports on the role of this locus in the etiology of schizophrenia. © 2005 Wiley‐Liss, Inc.
Family‐based association study of the serotonin transporter gene polymorphisms in Korean ADHD trios
Authors: Kim Soo‐Jeong , Badner Judith , Cheon Keun‐Ah , Kim Boong‐Nyun , Yoo Hee‐Jeong , Kim Se‐Joo , Cook Edwin , Leventhal Bennett L. , Kim Young Shin
Published: August 2005

The dopamine (DA) system has been implicated in attention deficit hyperactivity disorder (ADHD) based on pharmacologic evidence. Because of an interaction between the serotonin (5‐HT) and DA systems, the serotonin transporter gene (SLC6A4) has been considered as a candidate ADHD susceptibility gene. Two common polymorphisms, 5‐HTTLPR and the intron 2 VNTR, have been studied for association in ADHD, with both positive (increased frequency of long allele of 5‐HTTLPR and decreased frequency of 12 repeats of the intron 2 VNTR) and negative findings. However, there has not been an association study in an East Asian ADHD population. In this study, we examined the genotypes of these two polymorphisms in 126 Korean ADHD families and investigated linkage disequilibrium (LD) between SLC6A4 and ADHD, using the transmission disequilibrium test (TDT) and haplotype analysis. Additionally, association with quantitative measures of inattention, hyperactivity‐impulsivity, and overall severity was tested using logistic regression and QTDT analysis. TDT of both polymorphisms and haplotype analysis failed to detect LD. However, after excluding ADHD NOS subtype, TDT revealed nominally significant LD between 5‐HTTLPR and ADHD (χ2 = 4.9, P = 0.036). QTDT revealed positive association between 12 repeats of the intron 2 VNTR and attention (P = 0.031), but case‐control and TDT logistic regression analyses were negative. These markers have low heterozygosity in the Korean population, which would be expected to reduce the power of association. This result suggests that future studies should include more polymorphic markers and subjects to thoroughly investigate a potential association between SLC6A4 and ADHD in the Korean population. © 2005 Wiley‐Liss, Inc.
Non‐linear electrical conductivity of urea‐formaldehyde‐cellulose loaded with powders of different carbon fillers
Authors: Maaroufi Abdel‐Karim , Pinto Gabriel , Paz Isabel
Published: August 2005

This article reports on the making and characterization of composite materials prepared by compression molding of a commercial grade thermosetting resin of urea‐formaldehyde filled with α‐cellulose in powder form mixed successively with carbon black, synthetic graphite, and activated carbon. The morphology of the constituents and the composites has been characterized by optical microscopy. The porosity effect has been discussed from density measurements. Furthermore, it has been shown that the hardness of the samples remains almost constant with the increase of filler concentration. The electrical conductivity shows clearly a non‐linear behavior. The observed values are lower than 10−11 S/cm, unless the filler content reaches the percolation threshold beyond which the conductivity increases markedly by as much as ten orders of magnitude, indicating insulator‐conductor phase transition. The conduction threshold depends on the filler nature. The results have been interpreted by means of the statistical percolation theory. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 990–996, 2005
Antibacterial activity of modified polyamide fibers
Authors: Saïhi D. , El‐Achari A. , Vroman I. , Périchaud A.
Published: August 2005

Polyamide fibers were modified for the attainment of antibacterial activity using a graft copolymerization method. The fibers were grafted with monomers containing quaternary ammonium groups using sodium persulfate as initiator. Two monomers were used as vinyl monomers. The first monomer, called METAC, is methacryloyloxyethyl trimethylammonium chloride [H2C = C(CH3)‐ CO2CH2CH2N(CH3)3Cl]. The second monomer, denoted CATAL, is a methacryloyloxyethyl dimethyldodecylammonium bromide [H2C = C(CH3)CONHCH2CH2CH2N‐ (CH3)2(C12H25)Br], kindly supplied by Catalyze (France). The graft copolymerization was confirmed by several methods such as elemental analysis and FTIR spectroscopy. The antibacterial activity of modified samples was investigated against Staphylococcus aureus using the antibacterial standard AFNOR test method XP G39–100. Polyamide fibers grafted with the second monomer exhibit high antibacterial activity against S. aureus, but the fibers grafted with the methacryloyloxyethyl trimethylammonium chloride did not. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 997–1000, 2005
Polymerization in a magnetic field. XV Some azo‐initiators behavior in a high magnetic field
Authors: Chiriac Aurica P.
Published: August 2005

The effect of a high magnetic field of 7 T on styrene polymerization reactions was taken under study. The intervened magnetokinetic modifications are correlated to the system of radical initiation, respectively: benzoyl peroxide, 2, 2′‐azobis(2‐methylpropionitrile), 4, 4′‐azobis(4‐cyanopentanoic acid), and 1,1′‐azobis (cyclohexan‐1‐carbonitrile). The reaction products are also characterized from the viewpoint of their molecular weights correlated with the reaction conditions, as well as their thermal stability. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1025–1031, 2005
Effects of molding conditions on the electromagnetic interference performance of conductive ABS parts
Authors: Chen Shia‐Chung , Chien Rean‐Der , Lee Ping‐Hwei , Huang Jeng‐Sheng
Published: August 2005

Polymers filled with conducting fibers to prevent electromagnetic interference (EMI) performance have recently received great attention due to the requirements of 3C (computer, communication, and consumer electronics) products. In the present article, the effect of fiber content and processing parameters, including melt temperature, mold temperature, and injection velocity, on the electromagnetic interference shielding effectiveness (SE) in injection molded ABS polymer composites filled with conductive stainless steel fiber (SSF) was investigated. The influence of fiber orientation and distribution resulting from fiber content and molding conditions on EMI performance was also examined. It was found from measured results that fiber content plays a significant role in influencing part EMI SE performance. SE value can reach the highest values of approximately 40 dB and 60 dB at 1000 MHz frequency for fiber content 7 wt % and 14 wt %, respectively, under the best choice of molding conditions. Higher melt and mold temperature would increase shielding effectiveness due to a more uniform and random fiber orientation. However, higher injection velocity leading to highly‐orientated and less uniform distribution of fiber reduces shielding effectiveness. Among all molding parameters, melt temperature affects SE performance most significantly. Its influence slightly decreases as fiber content increases. Injection speed plays a secondary importance in affecting SE values, and its influence increases as fiber content increases. Upon examination of fiber distribution via optical microscope and subsequent image analysis, it was found that the fiber becomes more densely and random distributed toward the last melt‐filled region, whereas fiber exhibits less concentration around the middle way of the flow path. This can be attributed to the combined effects of fountain flow, frozen layer thickness, and gapwise melt front velocity. The results indicate that molding conditions, instead of fiber content alone, are very important on the SE performance for injection molded SSF filled ABS composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1072–1080, 2005
Spatial models in marketing research and practice
Authors: J. Bronnenberg Bart
Published: August 2005

Spatial models formalize how cross‐sectional observations relate to each other as a function of their spatial location. This paper discusses the generality of such models and how they are helpful to marketing practitioners in the description of marketing data, segmentation of markets, prediction of market behaviour, and the pooling of data. Copyright © 2005 John Wiley & Sons, Ltd.
The proper interpretation of sales promotion effects: supplement elasticities with absolute sales effects
Authors: van Heerde Harald J.
Published: August 2005

Sales promotions such as temporary price reductions are frequently used by managers to stimulate sales in the short run. Marketing academics and practitioners tend to rely on price elasticities to summarize sales promotion effects. Although elasticities have some attractive benefits such as the invariance to measurement units, they have led to three misinterpretations in the marketing literature, as described in this paper. The proper theoretical and managerial interpretation of sales promotion effects is obtained by expressing effects in terms of absolute sales. Copyright © 2005 John Wiley & Sons, Ltd.
Market response models and marketing practice
Authors: Hanssens Dominique M. , Leeflang Peter S. H. , Wittink Dick R.
Published: August 2005

Market response models are intended to help scholars and managers understand how consumers individually and collectively respond to marketing activities, and how competitors interact. Appropriately estimated effects constitute a basis for improved decision making in marketing. We review the demand and supply of market response models and we highlight areas of future growth. We discuss two characteristics that favour model use in practice, viz. the supply of standardized models and the availability of empirical generalizations.

Marketing as a discipline and market response models as a technology may often not receive top management attention. In order to have enhanced relevance for senior management, we argue that marketing models should be cross‐functional, include short‐ and long‐term effects, and be considerate of capital markets. We also identify emerging opportunities for marketing model applications in areas such as public policy and litigation. Copyright © 2005 John Wiley & Sons, Ltd.
Lessons from the front line: two key ways in which the internet has changed marketing forever
Authors: Drèze Xavier
Published: August 2005

Ten years after the first banner ad was served, we can reflect on how dramatically the Internet actually changed the way we conduct business. We highlight two areas in which there has been change that provides both challenges and opportunities to firms and researchers alike. First, we see the rise of permission‐based marketing as a great opportunity to increase the effectiveness of business‐to‐consumer communication. Second, we see auctions for the masses as a unique opportunity to learn more about the consumer's processing of price information. Copyright © 2005 John Wiley & Sons, Ltd.
The effect of survey measurement on respondent behaviour
Authors: Morwitz Vicki G.
Published: August 2005

Although it is well known that measures obtained from surveyed samples may not perfectly match the true values in the population, surveys are generally thought to reflect but not to change opinion or subsequent behaviour. The purpose of this paper is to review a new, growing stream of research that demonstrates that merely responding to a marketing research survey alters subsequent behaviour. The papers in this stream of research compare the behaviour of an experimental group where individuals respond to a marketing research survey to a control group where individuals do not complete a survey. The results show that measuring intentions or satisfaction in a marketing research survey, changes the behaviour of respondents in the experimental group. For positively viewed products, overall, respondents in the experimental group have higher purchase incidence, buy more quickly, and are more profitable customers than those in the control group. Further, the results in some cases persist over time. Although research to determine why this mere measurement effect occurs is ongoing, to date, results suggest that measurement increases the accessibility of attitudes toward the product, which in turn makes the resulting behaviour more consistent with those attitudes than when measurement does not occur. Copyright © 2005 John Wiley & Sons, Ltd.
An Additive Edge Correction for the Influence Potential of Trees
Authors: Kühlmann‐Berenzon S. , Heikkinen J. , Särkkä A.
Published: August 2005

The influence potential on a quadrat (IPQ) is an index for measuring the ecological effect that trees have on understory vegetation observed in a quadrat of a plot. IPQ is defined as the sum of the effect of every trees in the plot, where the effect depends on the size of the tree and the distance between the tree and the quadrat. Since only the trees in the plot have been observed and not the trees outside the plot, the true IPQ may be underestimated. Existing edge corrections are not appropriate for this case. We propose a correction that consists of adding the expected IPQ due to effects of trees outside the plot to the observed IPQ. The expectation is obtained by applying the Campbell theorem for stationary marked point processes. Data from the 1985–86 National Forest Inventory of Finland was used to calculate IPQ for six quadrats systematically allocated to each of 1240 plots. The implementation of the correction for this data is described. The distributions of IPQ with and without the correction proved the existence of edge effects and the effectiveness of the correction to eliminate the bias. This method has the potential to be applied to other additive functions. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparing the Likelihood Ratios of Two Binary Diagnostic Tests in the Presence of Partial Verification
Authors: Roldán Nofuentes J. A. , Luna del Castillo J. D.
Published: August 2005

The comparison of the efficiency of two binary diagnostic tests requires one to know the disease status for all patients in the sample, by applying a gold standard. In two‐phase studies the gold standard is not applied to all patients in a sample, and the problem of partial verification of the disease arises. At present, one of the approaches most used for comparing two binary diagnostic tests are the likelihood ratios. In this study, the maximum likelihood estimators of likelihood ratios are obtained. The tests of hypothesis to compare the likelihood ratios of two binary diagnostic tests when both are applied to the same random sample in the presence of verification bias are deduced, and simulation experiments are performed in order to investigate the asymptotic behaviour of the tests of hypothesis. The results obtained have been applied to the study of Alzheimer's disease. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Estimation of the Youden Index and its Associated Cutoff Point
Authors: Fluss Ronen , Faraggi David , Reiser Benjamin
Published: August 2005

The Youden Index is a frequently used summary measure of the ROC (Receiver Operating Characteristic) curve. It both, measures the effectiveness of a diagnostic marker and enables the selection of an optimal threshold value (cutoff point) for the marker. In this paper we compare several estimation procedures for the Youden Index and its associated cutoff point. These are based on (1) normal assumptions; (2) transformations to normality; (3) the empirical distribution function; (4) kernel smoothing. These are compared in terms of bias and root mean square error in a large variety of scenarios by means of an extensive simulation study. We find that the empirical method which is the most commonly used has the overall worst performance. In the estimation of the Youden Index the kernel is generally the best unless the data can be well transformed to achieve normality whereas in estimation of the optimal threshold value results are more variable. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural Heterogeneity in DNA: Temperature Dependence of 2‐Aminopurine Fluorescence in Dinucleotides
Authors: Somsen Oscar J. G. , Keukens Linda B. , de Keijzer M. Niels , van Hoek Arie , van Amerongen Herbert
Published: August 2005

The fluorescent base analogue 2‐aminopurine is a sensitive probe for local dynamics of DNA. Its fluorescence is quenched by interaction with the neighboring bases, but the underlying mechanisms are still under investigation. We studied 2‐aminopurine fluorescence in dinucleotides with each of the natural bases. Consistently, two of the four fluorescence‐decay components depend strongly on temperature. Our results indicate that these components are due to the excited‐state dynamics of a single conformational state. We propose a variation of the gating model in which transient unstacking occurs in the excited state.
Molecular Dynamics Simulation of Water Near Nanostructured Hydrophobic Surfaces: Interfacial Energies
Authors: Pal Sandeep , Roccatano Danilo , Weiss Horst , Keller Harald , Müller‐Plathe Florian
Published: August 2005

We present results from molecular dynamics simulations of water near structured hydrophobic surfaces. The surface structures reported herein are a planar alkane crystal as a reference and crystals with a hole and a protrusion of approximately 2.5 nm diameter and 0.5 nm depth or height. All indicators show that surface structuring increases the hydrophobicity: The water density is reduced near the structure elements, and the number of residual contacts between water and the surface decreases by about 40 % with respect to the planar surface. Thermodynamic integration shows that the interfacial energy of the structured surfaces is about 7 mJ m−2 higher for structured surfaces than for the planar surface. The hydrophobicity increases by a similar amount for the hole and the protrusion geometries compared to the planar surface.
Phase Diagram of Electrostricted H2O at Surfaces of Electrodes at 273–373 K: Electric Critical Point of Water
Authors: Danielewicz‐Ferchmin Irena , Ferchmin A. Ryszard
Published: August 2005

The equation of state of an open system containing water in an electric field of strength E greater than 108 V m−1 leads to a phase diagram with two‐phase and single‐phase regions in the Π,E,T coordinates (Π=electrostriction pressure). The phases differ by their degree of orientation of H2O molecules in the field. The phase transition is discontinuous with respect to E. The calculation shows that the discontinuity vanishes at the critical point: Πc≈0.2 GPa, Ec≈109 V m−1 and ${{\rm T}{{{\rm E}\hfill \atop c\hfill}}}$ below 313 K. The thermal effect of the transition is calculated and compared with an experiment at the Hg/aqueous electrolyte interface found in the literature.
In Situ and Online Monitoring of Hydrodynamic Flow Profiles in Microfluidic Channels Based upon Microelectrochemistry: Concept, Theory, and Validation
Authors: Amatore Christian , Oleinick Alexander , Klymenko Oleksiy V. , Svir Irina
Published: August 2005

Herein, we propose a method for reconstructing any plausible macroscopic hydrodynamic flow profile occurring locally within a rectangular microfluidic channel. The method is based on experimental currents measured at single or double microband electrodes embedded in one channel wall. A perfectly adequate quasiconformal mapping of spatial coordinates introduced in our previous work [Electrochem. Commun. 2004, 6, 1123] and an exponentially expanding time grid, initially proposed [J. Electroanal. Chem. 2003, 557, 75] in conjunction with the solution of the corresponding variational problem approached by the Ritz method are used for the numerical reconstruction of flow profiles. Herein, the concept of the method is presented and developed theoretically and its validity is tested on the basis of the use of pseudoexperimental currents emulated by simulation of the diffusion–convection problem in a channel flow cell, to which a random Gaussian current noise is added. The flow profiles reconstructed by our method compare successfully with those introduced a priori into the simulations, even when these include significant distortions compared with either classical Poiseuille or electro‐osmotic flows.
Cover Picture: Structural Colors in Nature: The Role of Regularity and Irregularity in the Structure (ChemPhysChem 8/2005)
Authors: Kinoshita Shuichi , Yoshioka Shinya
Published: August 2005

The cover picture shows the mechanism of structural color in the famous Morpho butterflies ranging over Central and South America. Their wings are covered extensively with iridescent scales, on which a lot of ridges bristle with regular projections at both sides. In their Review on page 1442 Kinoshita et al. demonstrate that these regular structures assist the selective reflection of blue light through interference, while their irregular heights give the diffusive light through diffraction. Thus the cooperation of regularity and irregularity generates wavelength‐selective, highly reflective, and spatially diffusive light in the blue region.
Synthesis, Characterization, and Electrochemical Properties of Dinuclear Complexes Assembled from Asymmetric CoIII Bis(dioximates) and Boronic Acids
Authors: Dreos Renata , Siega Patrizia , Scagliola Silvia , Randaccio Lucio , Nardin Giorgio , Tavagnacco Claudio , Bevilacqua Manuela
Published: August 2005

Bis(methylphenylglyoximate)cobalt(III) complexes exist both as cis and trans isomers due to the asymmetry of the equatorial ligand, and, when the axial ligands are different, the trans isomer is chiral. The reaction of racemic trans‐[CH3Co(mpgH)2py] (1) with either 3‐ or 4‐pyridylboronic acid affords dimeric units arranged on a crystallographic symmetry center such that the pyridyl nitrogen of one moiety coordinates to the Co atom of the symmetry‐related unit. In principle, three structurally different dimeric species (two homodimers and one heterodimer) can be obtained. Time‐resolved 1H NMR spectra of a 1:1 mixture of racemic 1 and either 3‐ or 4‐pyridylboronic acid in CDCl3/CD3OD show that the reaction does not converge toward a unique species in solution. Nevertheless, X‐ray structures show that the heterochiral dimers are the only products that crystallize from the reaction mixture. The nature of the dioximate side groups does not affect the geometry of the dimeric arrangements assembled by 4‐pyridylboronic acid (“molecular box”). On the contrary, the geometry of the species assembled by 3‐pyridylboronic acid varies from the “molecular parallelogram” obtained from the bis(dimethylglyoximates) to the highly squeezed “molecular box” obtained from bis(methylphenylglyoximates). Cyclic voltammetry studies show that the metal centers in the dimeric species do not interact with each other and undergo a simultaneous redox process. However, depending on the geometry of the systems, the redox process involves a single four‐electron reduction for 3 and 5 or two consecutive two‐electron reduction steps for 4 and 6. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Molecular Recognition – Allosterism Generated by Weak Host–Guest Interactions in Molecular Rectangles
Authors: Crowley James D. , Steele Ian M. , Bosnich Brice
Published: August 2005

Two metal‐based molecular rectangles that bear two identical binding sites form 1:2 host–guest adducts with a pair of analogous planar Pt2+ complexes. The larger of the two guests shows no binding allosterism with either of the two rectangles, but substantial positive allosterism is observed when the smaller guest binds to the rectangles. It is proposed that the smaller guest is better accommodated in the binding sites of the receptor and that this leads to allosterism. Various experiments, including 1H NOESY spectroscopy, support the supposition that the smaller guest is better incarcerated in the receptors. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Storage stability study of margarines produced from enzymatically interesterified fats compared to margarines produced by conventional methods. I. Physical properties
Authors: Zhang Hong , Jacobsen Charlotte , Adler‐Nissen Jens
Published: August 2005

In this study, margarine hardstocks were produced from two enzymatically interesterified fats at conversion degrees of 80 and 100%, a chemically randomized fat and a physically mixed fat, respectively. These four hardstocks blended with 50% of sunflower oil were mainly used for the production of table margarines in a pilot plant. Storage stability studies were carried out at storage temperatures of 5 and 25 °C during 12 wk. Margarines from the enzymatically interesterified fats were compared to the margarines produced by conventional methods and to selected commercial products. The changes in the physical properties of margarines, including hardness, dropping point, crystal form, and sensory evaluation, were examined during storage. It was observed that margarine storage stability increased with increasing conversion degree. The color of margarines made from the enzymatically interesterified fats was more similar to that of the physically mixed fat than that of the margarine from the chemically randomized fat, which had less color. Crystal transformation was accelerated at high storage temperature. Crystal size was not only related to the types of crystals, but also to the driving force of temperature difference. A larger crystal size was observed at 5 °C than at 25 °C for the margarine made from the blend. Margarines produced from interesterified fats had better physical properties than the blend. Overall, the margarine produced from the enzymatically fully converted fat had physical properties similar to the margarine produced from the chemically interesterified fat.
A Facile and Potent Synthesis of meso,meso‐Linked Porphyrin Arrays Using Iodine(III) Reagents
Authors: Jin Li‐Mei , Chen Liang , Yin Juan‐Juan , Guo Can‐Cheng , Chen Qing‐Yun
Published: August 2005

The synthesis of meso,meso‐linked fluoroalkylporphyrin arrays has been accomplished, in excellent yields, by the simple treatment of a CHCl3 solution of zincated 5‐fluoroalkyl‐10,20‐diarylporphyrins (where fluoroalkyl = CF3, ClC2F4, n‐ClC4F8, n‐C6F13, etc.) with iodine(III) reagents such as PhI(O–CO–CF3)2 (PIFA, also named as bis(trifluoroacetoxy)iodo]benzene) or PhI(OAc)2 (PIDA). For nonfluorinated zincated 5‐substituted‐10–20‐diarylporphyrins (where substituent = phenyl, 4‐methoxyphenyl, 4‐methylphenyl, etc.) the similar coupling reactions also proceed fast and quantitatively. Moreover, various 15‐unsubstituted metalloporphyrins can also be coupled in high yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
New Oblongolides Isolated from the Endophytic Fungus Phomopsis sp. from Melilotus dentata from the Shores of the Baltic Sea
Authors: Dai Jingqiu , Krohn Karsten , Gehle Dietmar , Kock Ines , Flörke Ulrich , Aust Hans‐Jürgen , Draeger Siegfried , Schulz Barbara , Rheinheimer Joachim
Published: August 2005

Thirteen new metabolites, namely oblongolides B–M (2–13) and 4‐[5‐(1‐hydroxyethyl)furan‐2‐yl]‐4‐oxobutanoic acid (14), together with the six known compounds phomopsolide B (15), alternariol dimethyl ether (16), alternariol monomethyl ether (17), the mycotoxin alternariol (18), ergosterol (19), and 5α,8α‐epidioxyergosterol (20) were isolated from the endophytic fungus Phomopsis sp. The new biologically active norsesquiterpene γ‐lactones differ in their degree of substitution, saturation, and substituent pattern from the known oblongolide 1. Their structures were determined by means of spectroscopic data including HREIMS, 1H NMR, 13C NMR, 2D NMR (HMQC, HMBC, NOESY) and X‐ray single crystal analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Regioselective and Divergent Opening of Vinyl Epoxides with Alkyne Nucleophiles
Authors: Restorp Per , Somfai Peter
Published: August 2005

A divergent procedure for nucleophilic ring‐opening of vinyl epoxides with alkynes has been developed. The combination of lithium acetylides and BF3·OEt2 afforded the SN2 products, whereas alkynylalanes gave SN2′ addition. The regioselectivity of these processes is affected by the alkyne substituent. Ethoxyacetylene added with complete regiocontrol under both SN2 and SN2′ conditions, and the SN2 isomeric adducts could be rearranged into γ‐butyrolactones. The synthetic utility of the process is demonstrated by a short synthesis of γ‐butyrolactone 24, a key intermediate in the synthesis of prostaglandin PGF2α. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Investigation of solvent effects in capillary electrophoresis for the separation of biological porphyrin methyl esters
Authors: Li Qi , Chang Chi K. , Huie Carmen W.
Published: August 2005

The effects of organic solvents on the capillary electrophoresis (CE) separation of a number of important biological porphyrin methyl esters – six weakly basic, hydrophobic cyclic tetrapyrroles possessing two and four to eight methyl ester groups around the periphery of the porphyrin ring – were investigated in the mode of micellar electrokinetic chromatography (MEKC), microemulsion electrokinetic chromatography (MEEKC), and nonaqueous CE. In aqueous MEKC, partial separation of the six neutral porphyrin methyl esters was obtained with an organic modifier (acetonitrile) in the concentration range between 20 and 40%, in which sodium dodecyl sulfate (SDS) molecules might be present in the form of SDS micelles and/or SDS micelle‐like aggregates. Relatively stable SDS micelles can be formed in nonaqueous MEKC using formamide as the separation medium, but the separation of the target analytes remained unsatisfactory. Improved resolution of all six porphyrin methyl esters was obtained using MEEKC with the running buffer consisting of 0.8% w/w n‐heptane (oil phase), 2.25% w/w SDS and 1.0% w/w Brij 35 (mixed surfactant), 6.6% w/w 1‐butanol (cosurfactant), and 30% v/v 2‐propanol (second cosurfactant), but reproducibility in terms of peak areas for certain porphyrins (especially uroporphyrin I octamethyl ester) was found to be very poor. Best separation performances were achieved with nonaqueous CE separations in which the weakly basic porphyrin methyl esters were protonated under strongly acidic conditions (e.g., using 10 mM perchloric acid) in mixed organic solvents. For example, using a 50:50 mixture of methanol and acetonitrile as the separation medium, baseline separation of all six (positively charged) porphyrin methyl esters can be obtained within 3 min and the average precision (RSD, N = 13) in terms of migration time and peak area were 0.55 and 2.16%, respectively.
Nonaqueous capillary electrophoresis in coated capillaries: An interesting alternative for proteomic applications
Authors: Assunção Nilson A. , Deziderio Leandro A. Grange , Paulino Luis G. , Lupetti Karina O. , Carrilho Emanuel
Published: August 2005

This work brings together some contributions for the use of nonaqueous media for proteomic analysis, for both capillary electrophoresis (CE) separation and the preparation of tryptic digests. First, a ternary nonaqueous buffer consisting of 60/30/10 v/v methanol/acetonitrile/acetic acid with 12.5 mmol/L ammonium acetate was optimized for CE separation of the tryptic digest of lysozyme. Lysozyme was chosen as a model system for the protein digestion, which has also been prepared in an organic‐rich medium with methanol/50 mmol/L NH4HCO3, pH 8.0 (60/40 v/v). The separation results were compared to in silico (PeptideCutter program) digestion conditions, and high‐efficiency peak separation (18 peaks) was obtained in 20 min with an electric field of 350 V/cm. In addition, we have evaluated the stability of a coated capillary with poly‐N,N‐dimethylacrylamide (60/30 cm total/effective length and 75 μm ID) for over 100 runs of tryptic digest with the nonaqueous background electrolyte solvent system. The migration times for ten selected peptide peaks presented 3–7% relative standard deviation.
Age effects on diffusion tensor magnetic resonance imaging tractography measures of frontal cortex connections in schizophrenia
Authors: Jones Derek K. , Catani Marco , Pierpaoli Carlo , Reeves Suzanne J.C. , Shergill Sukhwinder S. , O'Sullivan Michael , Golesworthy Pasha , McGuire Phillip , Horsfield Mark A. , Simmons Andrew , Williams Steven C.R. , Howard Robert J.
Published: August 2005

Diffusion tensor magnetic resonance imaging (DT‐MRI) has previously been used to investigate white matter tracts in schizophrenia, with inconsistent results. The aim of the study was to use a novel method for tract‐specific measurements of fronto‐temporal fasciculi in early‐onset schizophrenia. We hypothesized that by making tract‐specific measurements, clear diffusion abnormalities would be revealed in specific fasciculi in schizophrenia. Measurements of diffusion anisotropy and mean diffusivity were localized within fronto‐temporal fasciculi by forming 3‐D reconstructions of the cingulum, uncinate, superior longitudinal, and inferior fronto‐occipital fasciculi using diffusion tensor tractography. We were limited in our ability to test our hypothesis by the important and surprising finding that age affected DT‐MRI‐based measures in schizophrenia patients in a different way from comparison subjects, most notably in the left superior longitudinal fasciculus. The youngest schizophrenia patients that we studied had lower diffusion anisotropy than age‐matched comparison subjects, but this difference diminished with increasing age. The main conclusion of this study was that direct comparisons of absolute DT‐MRI‐based measures between individuals with schizophrenia and comparison subjects may be problematic and misleading because of underlying age‐related differences in brain maturation between groups. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Impact of organizational change on the delivery of reproductive services: a review of the literature
Authors: Ensor Tim , Ronoh Jeptepkeny
Published: August 2005

In order to understand the impact of specific maternal health interventions, it is necessary to understand the likely effect of the health system structure. An important aspect of this structure is the organizational culture. Many systems in low‐income countries have been based on a centrally planned and financed system. In recent years a series of organizational changes have been introduced into many systems and these substantially alter the way in which the system operates and impacts on reproductive health care provision. The main changes reviewed in this paper are: (i) decentralization, (ii) privatization and (iii) integration and sector wide approaches. Each of these changes is seen to have important implications for reproductive health. In each case it is clear that the nature of the impact depends crucially on the way it is implemented. Quantifying the impact of these changes remains extremely difficult given the many different ways they can be introduced and the many confounding factors that affect the overall impact. The literature does, however, point to a number of key issues that impinge on the way in which change is likely to affect reproductive health initiatives. Copyright © 2005 John Wiley & Sons, Ltd.
Transferable learning from international primary care developments
Authors: Meads Geoffrey , Iwami Michiyo , Wild Andrea
Published: August 2005

Alternative approaches to the comparative analysis of international health systems developments are reviewed in relation to the advent of new primary care organizations in countries with parallel ‘modernizing’ policies. A framework for transferable learning between these is articulated and its design described. This is derived from priorities defined by lead policy and practice representatives in UK primary care. It points to the benefits of examining the interaction of critical new public management and planning functions as an effective vehicle for identifying both individual country role models and shared international experiences. Illustrative examples are provided in five subject areas ranging from local engagement to multiple forms of financing. Copyright © 2005 John Wiley & Sons, Ltd.
Identification and thermodynamic treatment of several types of large‐amplitude motions
Authors: Katzer Gernot , Sax Alexander F.
Published: August 2005

We present a partially automated method for the thermodynamic treatment of large‐amplitude motions. Starting from the molecular geometry and the Hessian matrix, we evaluate anharmonic partition functions for selected vibrational degrees of freedom. Supported anharmonic vibration types are internal rotation and inversion (oscillation in a double‐well potential). By heuristic algorithms, we identify internal rotations in most cases automatically from the Hessian eigenvectors, and we also estimate the parameters of anharmonic partition functions (e.g., potential barrier, periodicity, and symmetry number) with thermodynamically sufficient precision. We demonstrate the validity of our schemes by comparison to pointwise calculated ab initio potential curves. © 2005 Wiley Periodicals, Inc. J Comput Chem 14: 1438–1451, 2005