bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemostatic Risk Factors and Insulin Sensitivity, Regional Body Fat Distribution, and the Metabolic Syndrome
Authors: Godsland I. F. , Crook D. , Proudler A. J. , Stevenson J. C.
Published: January 2005

Disturbances in the thrombotic and fibrinolytic systems are a feature of insulin resistance, obesity, and the metabolic syndrome. However, there are few studies in which these relationships have been explored in mainly asymptomatic individuals using sophisticated measures of insulin sensitivity and regional adiposity. Variables of the hemostatic system were measured in 106 men (aged 32–68 yr; body mass index, 20–34 kg/m2). Insulin sensitivity was measured by minimal model analysis and regional adiposity by dual energy x-ray absorptiometry. Clustering of intercorrelated variables was assessed by the statistical technique of factor analysis. Plasma levels of procoagulant factors VII and X, anticoagulant proteins C and S, and plasminogen activator inhibitor-1 correlated positively with total and percent central body fat (r = 0.25–0.38; P < 0.05) and negatively with insulin sensitivity (except protein S; r = −0.24 to −0.35; P < 0.05). On factor analysis, procoagulant factors VII and X, proteins C and S, and plasminogen activator inhibitor-1 were components of the cluster of variables that explained the greatest proportion of the variance in the data (39.2%). Other variables included in this cluster were those typical of the metabolic syndrome and also serum γ-glutamyl transferase activity. These results suggest that factors VII and X and proteins C and S are features of the intercorrelated disturbances of the metabolic syndrome. Associations with adiposity and liver enzyme activity suggest the involvement of hepatic fat deposition.
Gonadotroph Tumor Associated with Multiple Endocrine Neoplasia Type 1
Authors: Benito Maria , Asa Sylvia L. , LiVolsi Virginia A. , West Valerie A. , Snyder Peter J.
Published: January 2005

Although anterior pituitary tumors constitute a main clinical feature of multiple endocrine neoplasia type 1 (MEN1), and most types of pituitary tumors have been associated with MEN1, gonadotroph tumors have not previously been recognized clinically as part of this syndrome. We report here a woman who presented with ovarian hyperstimulation due to a gonadotroph tumor that was confirmed biochemically and immunohistochemically. She then developed hyperparathyroidism, and she was found to have three hypercellular parathyroid glands. Subsequently, she developed a temporal lobe metastasis of the gonadotroph tumor, demonstrating that it was a gonadotroph carcinoma. The diagnosis of MEN1 was confirmed by finding a deletion mutation (c.307delC) on the second exon of the MEN1 gene that predicts truncation of the resulting menin protein 15 codons downstream from the deletion (p.Leu103fsX15). This case illustrates that gonadotroph tumors, like other pituitary tumors, can be part of MEN1. The clinical implications of this case are that the clinical and biochemical features of gonadotroph tumors should be considered when evaluating patients for MEN1, and MEN1 should be considered in patients who have gonadotroph tumors.
Inflammation, Insulin Resistance, and Glucose Intolerance in Acute Myocardial Infarction Patients without a Previous Diagnosis of Diabetes Mellitus
Authors: Choi K. M. , Lee K. W. , Kim S. G. , Kim N. H. , Park C. G. , Seo H. S. , Oh D. J. , Choi D. S. , Baik S. H.
Published: January 2005

We examined the prevalence of impaired glucose metabolism and its association with inflammation and insulin resistance (IR) in acute myocardial infarction (AMI) patients without a previous diagnosis of diabetes. This prospective study enrolled 52 AMI patients, and 75-g oral glucose tolerance testing was performed on 30 patients at discharge and again 3 months later. We also measured serum adiponectin, high sensitive C-reactive protein, and IL-6 on both occasions. Data were compared with those of 30 type 2 diabetic patients without a history of AMI. Forty percent and 36.7% of AMI patients had impaired glucose tolerance (IGT) at discharge and at 3 months, respectively. The corresponding proportions for newly diagnosed diabetes are 33.0% and 30.0%. At discharge, AMI patients with IGT or diabetes showed higher high sensitive C-reactive protein and IL-6 levels compared with AMI patients with normal glucose tolerance or control type 2 diabetic patients. Furthermore, AMI patients with IGT or diabetes exhibited higher IR and lower serum adiponectin levels than AMI patients with normal glucose tolerance at 3 months after discharge. Previously undiagnosed diabetes and IGT are common in Korean patients with AMI. These glycometabolic abnormalities are associated with inflammation, IR, and serum adiponectin levels.
Label-retaining epithelial cells in mouse mammary gland divide asymmetrically and retain their template DNA strands
Authors: Smith Gilbert H.
Published: January 2005

It has been postulated that the stem cells of somatic tissues protect themselves from mutation and cancer risk by selective segregation of their template DNA strands. Self-renewing mammary epithelial stem cells that were originated during allometric growth of the mammary ducts in pubertal females were labeled using [3H]-thymidine (3HTdR). After a prolonged chase during which much of the branching duct morphogenesis was completed, 3HTdR-label retaining epithelial cells (LREC) were detected among the epithelium of the maturing glands. Labeling newly synthesized DNA in these glands with a different marker, 5-bromodeoxyuridine(5BrdU), resulted in the appearance of doubly labeled nuclei in a large percentage of the LREC. By contrast, label-retaining cells within the stroma did not incorporate 5BrdU during the pulse, indicating that they were not traversing the cell cycle. Upon chase, the second label (5BrdU) was distributed from the double-labeled LREC to unlabeled mammary cells while 3HTdR was retained. These results demonstrate that mammary LREC selectively retain their 3HTdR-labeled template DNA strands and pass newly synthesized 5BrdU-labeled DNA to their progeny during asymmetric divisions. Similar results were obtained in mammary transplants containing self-renewing, lacZ-positive epithelial cells suggesting that cells capable of expansive self-renewal may repopulate new mammary stem cell niches during the allometric growth of new mammary ducts.
Effect and control of hatch length on material properties in the direct metal laser sintering process
Authors: Ning Y , Wong Y S , Fuh J Y H
Published: January 2005

As one of the advanced rapid prototyping and manufacturing processes, the direct metal laser sintering (DMLS) process gives designers the possibility of building parts of almost any complexity in a wide range of metal materials. In DMLS, the sintered material is anisotropic and heterogeneous, affecting the quality and performance of the built parts. This paper presents a study that focuses on these two material characteristics and proposes a method to control them. Firstly, a series of experiments have been designed and conducted to study the influence of material anisotropy and heterogeneity on the built part strength. The heterogeneity was analysed and the microstructural changes due to different hatch line lengths were observed using scanning electron microscopy. The relationship between the hatch line length and the part quality is derived on the basis of experimental data collected and an appropriate statistical analysis applied. A genetic algorithm method is also proposed to optimize the hatch direction for obtaining more homogeneous sintered material properties. The experimental results verify that the negative effect of varying hatch lines in the early sintering process can be controlled effectively.
Finite element simulation of the thermal properties of particulate and continuous network-reinforced metal-matrix composites
Authors: Liu X D , Zhang J S , Cao X M , Zhang H
Published: January 2005

An analysis of the effective coefficient of thermal expansion (CTE) and thermal conductivity (TC) of metal-matrix composites was conducted, focusing on composites with potential for use in electronic packaging applications. Using the finite element method, these thermal properties were simulated on discontinuous SiC-particle and continuous three-dimensional SiC-network-reinforced Al-matrix composites. The calculated CTEs of particle-reinforced composites agree well with those predicted by the Kerner model. While these CTEs increase with increasing temperature, the composites with SiC networks were found to exhibit the opposite trend in the high-temperature region (above about 250 °C). The TCs of the three-dimensional SiC-network-reinforced composites are found to be much less sensitive to volume fraction of reinforcement than those of particle-reinforced composites. Continuous three-dimensional network-reinforced composites possess a higher TC than particulate composites, and their CTEs agree well with those of the electronic devices. Therefore, it is possible to use three-dimensional SiC-network-reinforced Al-matrix composites as electronic packaging materials to achieve a high heat dissipation rate and yet to minimize interfacial stresses resulting from a CTE mismatch.
One-pass milling machining parameter optimization to achieve mirror surface roughness
Authors: Wang S-G , Hsu Y-L
Published: January 2005

In this paper, the possibility of just using general machine centres in one-pass milling process to finish an aluminium plate with the mirror surface roughness is studied. In particular, how to find the optimal setting of machining parameters is presented. In this optimization problem, to evaluate whether the surface roughness meets the average criterion of a mirror surface requires real cutting experiments, and it is desirable to find the optimal machining parameters using as few experiments as possible. The ‘sequential neural network approximation method’ was used to find the optimal machining parameters, including the spindle speed, feed rate, depth of cut, and number of inserted blades in the cutter to maximize the metal removal rate while the surface roughness meets the average criterion of a mirror surface.
Modelling the transient behaviours of a fully penetrated gas-tungsten arc weld pool with surface deformation
Authors: Zhao P C , Wu C S , Zhang Y M
Published: January 2005

Numerical analysis of the dynamic behaviours of a gas-tungsten arc (GTA) weld pool with full penetration is of great significance to designing the process control algorithm. In this paper, a three-dimensional transient numerical model is developed to investigate the dynamic behaviours of a fully penetrated GTA weld pool with surface deformation. A body-fitted coordinate system is used to transform the complex physical boundaries resulted from the surface deformation into regular boundaries. A separated algorithm is employed to solve the strongly coupling problems between the surface deformation, fluid flow, and heat transfer. By using the model, the whole gas-tungsten arc welding (GTAW) process (including arc ignition, weld pool formation and growth, penetration, quasi-steady state, and arc extinguishments) are simulated, and the transient development of a three-dimensional weld pool shape and fluid flow inside the pool are obtained. The predicted weld geometry matches the experimental results. It provides useful basic data for the development of sensing and control systems of GTAW.
Slipline field solutions for metal machining with adhesion friction and elastic effects at the chip-tool contact region
Authors: Das N S , Dundur S T
Published: January 2005

Slipline field solutions for orthogonal metal machining are presented by considering elastic effects on chip formation and assuming adhesion friction at the chip-tool interface. The slipline fields are constructed following the matrix operational procedure developed by Dewhurst and Collins and by Dewhurst and assuming a linear relation between the angular range of α and β lines within the secondary shear zone. The limits of validity of the proposed solutions are examined using Hill's overstressing criteria. Elastic, plastic, total cutting, and total thrust forces and contact lengths are computed assuming an exponential pressure distribution in the elastic contact region. Results indicate that for any given rake angle and coefficient of friction the machining parameters are not uniquely determined but may have a range of allowable values and this is due to the non-unique nature of the machining process. Rake angle and rake friction are found to be the most important variables that influence cutting forces, cutting ratio, and contact length. The predicted results show excellent agreement with experimental observations, especially at small rake angles.
Multielement Determination of Trace Metals in Seawater by ICP-MS Using a Chelating Resin-Packed Minicolumn for Preconcentration
Authors: Zhu Yanbei , Itoh Akihide , Haraguchi Hiroki
Published: January 2005

A chelating resin-packed minicolumn was developed to pretreat seawater samples for the determination of trace metals by inductively coupled plasma mass spectrometry (ICP-MS). The preconcentration conditions, such as the flow rate of sample loading, pH for adsorption, amount of ammonium acetate for eliminating matrix elements, and the amount of nitric acid for eluting trace metals from the resin, were investigated and optimized. Firstly, 50 mL of seawater samples was adjusted to pH 6.0 and loaded into the column at the flow rate of 3 mL min−1. Secondly, 8 mL of 1 M ammonium acetate and 5 mL of pure water were passed through the column for eliminating matrix elements, such as Mg and Ca. Finally, trace metals were eluted with 2.25 mL of 2 M nitric acid, and then 0.25 mL of internal standard elements (Ge, In, Re, Tl, 100 μg L−1 each) was added to the eluted solution in order to correct matrix effects in the ICP-MS measurements. The recoveries for 23 elements (Mn, Co, Ni, Cu, Zn, Y, Cd, all-REEs, Pb, and U) were more than 80%. The analytical results for the concentrations of trace metals in seawater reference material (NASS-5) agreed well with certified or reference values. The present method was also applied to the multielement analysis of the coastal seawater samples from the Take Island (Gamagoori, Aichi prefecture, Japan) and the Ise Bay (Nagoya, Aichi prefecture, Japan).
In-Situ DRIFT Study of a New Low-Temperature Methanol Synthesis Mechanism
Authors: Yang Ruiqin , Fu Yilu , Zhang Yi , Xu Bolian , Tsubaki Noritatsu
Published: January 2005

In-situ DRIFTS was used to clarify the reaction mechanism of a new methanol synthesis method on a Cu/ZnO catalyst at low temperature from syngas containing CO2 using an ethanol promoter. The formate species was formed by exposing Cu/ZnO catalyst to syngas, and it reacted easily with ethanol to form an ethyl formate species at low temperature. Ethyl formate was easily reduced to form methanol.
Substituent Effects on the Gas Phase Acidity of Phenylacetylenes and Benzyl Alcohols
Authors: Matsuoka Mio , Mustanir  , Than Soe , Mishima Masaaki
Published: January 2005

The gas phase acidities of meta- and para-substituted phenylacetylenes and benzyl alcohols were determined by measuring equilibrium constants of proton transfer reactions using a FT-ICR spectrometer. The gas phase acidities of phenylacetylenes and benzyl alcohols are related linearly to those of benzoic acids with a slope of unity. Since the CH2 group of benzyl alcohol prevents a direct π-electron interaction between substituents and the negative charge at the oxygen atom, the existence of these linear relationships suggests that σo parameters best describe the substituent effects in all three systems. Indeed, the acidities of phenylacetylenes and benzoic acids correlate with σo values determined in the gas phase. The theoretical calculations of these acidities at MP2/6-311++G**//B3LYP/6-311++G** level of theory could reproduce the substituent effects observed experimentally. The optimized geometries and the elctrostatic charges computed using the CHELPG scheme of Breneman for the conjugate anions of all three acid systems also indicate that there is no π-delocalization of the negative charge into the benzene ring.
Investigation of the Structure and Stability of an Alcohol-Based Polymer for Hydrogen Storage in the Form of Ions
Authors: Matsuura Hiroshi , Tanikawa Tamio , Ushiba Shuichi , Ogawa Makoto
Published: January 2005

This study reports on the structure and stability of an alcohol-based polymer, which stores hydrogen in the form of ions. The hydrogen-storing polymer is produced from alcohol using a plasma-induced method. Measurements of the electrical resistivity and the IR spectra of the polymer indicate that it is in an electrically unstable state. The hydrogen produced by the polymer following the application of an electric signal demonstrates that the hydrogen ions are trapped within the polymer. The development of hydrogen-storing techniques in the form of ions improves the controllable extraction of hydrogen.
Platinum-catalyzed Tandem Carboalkoxylation-Claisen Rearrangement of Arylalkynes Bearing an ortho-1,5-Dihydro-3H-2,4-dioxepine Group
Authors: Nakamura Itaru , Bajracharya Gan B , Yamamoto Yoshinori
Published: January 2005

The platinum-catalyzed tandem carboalkoxylation-Claisen rearrangement reaction of arylalkynes 1 bearing an ortho-1,5-dihydro-3H-2,4-dioxepine group gave the corresponding tricyclic compounds 2 in good to allowable yields. For example, the reaction of 2-[2-(pent-1-ynyl)phenyl]-4,7-dihydro[1,3]dioxepin 1a, 2-[2-(oct-1-ynyl)phenyl]-4,7-dihydro[1,3]dioxepin 1c, and 2-[2-(phenylethynyl)phenyl]-4,7-dihydro[1,3]dioxepin 1d in the presence of 10 mol % of PtCl2 and 40 mol % of β-pinene in acetonitrile at 100 °C gave the corresponding tricyclic compounds 2a, 2c, and 2d in 69, 63, and 50% yields, respectively.
Kilogram-scale [60]Fullerene Separation from a Fullerene Mixture: Selective Complexation of Fullerenes with 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU)
Authors: Nagata Koichi , Dejima Eiji , Kikuchi Yasuharu , Hashiguchi Masahiko
Published: January 2005

A very simple and efficient separation procedure for [60]fullerene from a fullerene mixture has been developed using the novel selective complexation of fullerenes with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). From 3.3 kg of the fullerene mixture, 1.35 kg of pure [60]fullerene was obtained.
A New Method for the Lactonization of ω-Hydroxy Carboxylic Acids with Di-2-thienyl Carbonate by the Promotion of DMAP and Iodine
Authors: Oohashi Yoshiaki , Fukumoto Kentarou , Mukaiyama Teruaki
Published: January 2005

Successive reactions of ω-hydroxycarboxylic acids with an equimolar amount of di-2-thienyl carbonate (2-DTC) in the presence of a catalytic amount of 4-(dimethylamino)pyridine (DMAP) followed by an addition of 2–4 equimolar amounts of iodine afforded the corresponding lactones in good to high yields.
Asymmetric Synthesis of Axially Chiral cis-Arylmethylenebicyclo[3.3.0]octanes Using α-Thio- and α-Selenoorganolithium Compounds
Authors: Wang Libo , Nakamura Shuichi , Shibata Norio , Toru Takeshi
Published: January 2005

Enantioselective reaction of α-thio carbanion derived from 1-phenyl-1-(phenylthio)-1-(tributylstannyl)methane with cis-bicyclo[3.3.0]octane-3,7-dione monoethylene ketals in the presence of bis(oxazoline)s gave products with high diastereoselectivity and with high enantioselectivity. The reaction of α-seleno carbanions derived from bis(phenylseleno)arylmethanes also showed high diastereoselectivity and enantioselectivity. Deprotection and subsequent stereospecific elimination afforded axially chiral cis-arylmethylenebicyclo[3.3.0]octanes with high enantioselectivity (up to 99% ee).
Lewis Base-catalyzed anti-Selective Mannich-type Reaction between Trimethylsilyl Enolates and Aldimines
Authors: Takahashi Eiki , Fujisawa Hidehiko , Mukaiyama Teruaki
Published: January 2005

Potassium or ammonium carboxylates catalyzed Mannich-type reaction between trimethylsilyl enolates and aldimines proceeded smoothly to afford the corresponding β-amino carbonyl compounds in good to high yields with high anti selectivity.
Simplified Synthesis of Cobalt Ferrite Nanotubes Using Sol–Gel Method
Authors: Ji G B , Su H L , Tang S L , Du Y W , Xu B L
Published: January 2005

Cobalt ferrite nanotubes with diameter of 50 nm were prepared using a simple sol–gel process within the pores of anodic aluminum oxide (AAO) template. SEM, TEM, XRD, VSM were used to characterize the morphology, crystalloid structure, and magnetic properties of the samples. The results indicate that the cobalt ferrites thus prepared were polycrystalline phase with the smooth and uniform tube-like structure. The method is also expected to be applicable to the preparation of other multicomponent oxide nanotubes.
Toward an Integration of Agent- and Activity-Centric Approaches in Organizational Process Modeling: Incorporating Incentive Mechanisms
Authors: Raghu T. S. , Jayaraman B. , Rao H. R.
Published: January 2005

This paper presents an approach to organizational modeling that combines both agent-centric and activity-centric approaches. Activity-centric approaches to process modeling capture the mechanistic components of a process (including aspects of workflow, decision, and information), but agent-centric approaches capture specific aspects of the human component. In this paper, we explore an integrative viewpoint in which the transactional aspects of agent-centric concerns—for example, economic incentives for agents to perform—are integrated with decision and informational aspects of a process. To illustrate issues in this approach, we focus on modeling incentive mechanisms in a specific sales process and present results from an extensive simulation experiment. Our results highlight the importance of considering the effects of incentives when decision and informational aspects of a process undergo changes.
Internet Users' Information Privacy Concerns (IUIPC): The Construct, the Scale, and a Causal Model
Authors: Malhotra Naresh K. , Kim Sung S. , Agarwal James
Published: January 2005

The lack of consumer confidence in information privacy has been identified as a major problem hampering the growth of e-commerce. Despite the importance of understanding the nature of online consumers' concerns for information privacy, this topic has received little attention in the information systems community. To fill the gap in the literature, this article focuses on three distinct, yet closely related, issues. First, drawing on social contract theory, we offer a theoretical framework on the dimensionality of Internet users' information privacy concerns (IUIPC). Second, we attempt to operationalize the multidimensional notion of IUIPC using a second-order construct, and we develop a scale for it. Third, we propose and test a causal model on the relationship between IUIPC and behavioral intention toward releasing personal information at the request of a marketer. We conducted two separate field surveys and collected data from 742 household respondents in one-on-one, face-to-face interviews. The results of this study indicate that the second-order IUIPC factor, which consists of three first-order dimensions—namely, collection, control, and awareness—exhibited desirable psychometric properties in the context of online privacy. In addition, we found that the causal model centering on IUIPC fits the data satisfactorily and explains a large amount of variance in behavioral intention, suggesting that the proposed model will serve as a useful tool for analyzing online consumers' reactions to various privacy threats on the Internet.
IT Outsourcing Success: A Psychological Contract Perspective
Authors: Koh Christine , Ang Soon , Straub Detmar W.
Published: January 2005

Information technology (IT) outsourcing success requires careful management of customer-supplier relationships. However, there are few published studies on the ongoing relationships, and most of these adopt a customer perspective, de-emphasizing suppliers. In this study, we look at both customer and supplier perspectives, by means of the psychological contract of customer and supplier project managers. We apply the concept of psychological contract to perceived mutual obligations, and to how such fulfillment of obligations can predict success. Our research questions are (1) What are the critical customer-supplier obligations in an IT outsourcing relationship? and (2) What is the impact of fulfilling these obligations on success?

We use a sequential, qualitative-quantitative approach to develop and test our model. In the qualitative study, we probe the nature of customer-supplier obligations using in-depth interviews. Content analysis of interview transcripts show that both customers and suppliers identify six obligations that are critical to success. Customers perceive supplier obligations to be accurate project scoping, clear authority structures, taking charge, effective human capital management, effective knowledge transfer, and effective interorganizational teams. Suppliers perceive customer obligations as clear specifications, prompt payment, close project monitoring, dedicated project staffing, knowledge sharing, and project ownership. In the second quantitative study, we assess the impact of fulfilling these obligations on success through a field study of 370 managers. Results show that fulfilled obligations predict success over and above the effects of contract type, duration, and size.
Bradley — Terry — Luce models to incorporate within‐pair order effects: Representation and uniqueness theorems
Authors: Augustin Thomas
Published: January 2005

The paper presents different representation theorems for the Bradley — Terry — Luce (BTL) models of Beaver and Gokhale and of Davidson and Beaver. In particular, algorithms that can be used in constructing BTL scales are provided. The uniqueness theorems show that the Davidson — Beaver model should be preferred to the Beaver — Gokhale model since the multiplicative order effect parameter is uniquely determined whereas the additive effect parameter is merely a ratio scale. Finally, a relationship to the simple BTL model is established. Let p(a, b) denote the probability that a is chosen when (a, b) is presented in a fixed order. Then the probabilities p(a, b) satisfy the Beaver — Gokhale model if and only if the balanced probabilities pb(a, b):= ½ (p(a, b) + 1–p (b, a)) satisfy the simple BTL model.
Positioning a ‘mature’ self in interactive practices: How adolescent males negotiate ‘physical attraction’ in group talk
Authors: Korobov Neill , Bamberg Michael
Published: January 2005

This article presents a discursive psychological approach in examining the ways that adolescent boys (ages 12–15 years) accomplish a sense of ‘maturity’ by bringing off and managing certain features of ‘heterosexuality’ in group interaction. We focus on and analyse moments when the boys negotiate implicit challenges, make evaluations and offer assessments concerning their physical and sexual attraction to girls' looks. These moments are highly important for negotiating their peer status, for working toward a distinction between ‘childhood’ and ‘adolescence’, and for marking a normatively heterosexual self within the burgeoning institution of adolescence. We will specifically show how ‘heterosexual desire’ is carefully managed in group discussions where the boys participate in normative heterosexuality, but in ways that are nevertheless designed to appear mature and knowing, rather than shallow, naïve or sexist. Three discursive methods of negotiation are identified and described in detail: (1) underscoring the non‐literality of actions by appealing to motives, (2) denials with built‐in concessions, and (3) differentiation through caricature. Couched within the proposed discursive framework, we are reversing the traditional logic of developmental approaches to ‘maturation’. Rather than viewing maturation as the effect of resolving developmental tasks, we argue that ‘maturity’ comes to existence in the way talk is accomplished; that is, as highly flexible and fragile projections of identity that involve a continuous refinement of ‘finely tuned positioning skills'.
Relationship between In Vitro Lipopolysaccharide-Induced Cytokine Response in Whole Blood, Angiographic In-Stent Restenosis, and Toll-Like Receptor 4 Gene Polymorphisms
Authors: Rittersma Saskia ZH , Kremer Hovinga Johanna A , Koch Karel T , Boekholdt S Matthijs , van Aken Benien E , Scheepmaker Arko , Bax Matthijs , Schotborgh Carl E , Piek Jan J , Tijssen Jan GP , Reitsma Pieter H , de Winter Robbert J
Published: January 2005

Background: In coronary in-stent restenosis (ISR), a substantial contribution of inflammation is assumed. We evaluated the association between polymorphisms in the Toll-like receptor 4 (TLR4) gene and cytokine response after lipopolysaccharide (LPS) challenge and the development of ISR.

Methods: Patients were included after successful elective stent placement in a native coronary artery and were scheduled for follow-up angiography after 6 months. Quantitative coronary analysis was performed off-line. Patient whole blood was challenged with LPS for 24 h. Baseline and stimulated concentrations of interleukin (IL)-1β, IL-6, tumor necrosis factor-α, and IL-10 were assessed by ELISA. Two cosegregating single-nucleotide polymorphisms in the TLR4 gene (Asp299Gly and Thr399Ile) were analyzed by allele-specific PCR amplification of genomic DNA.

Results: A total of 236 consecutive patients were included, and 40 (17%) developed ISR. Median baseline and stimulated cytokine concentrations did not differ between patients with and without ISR. In multivariate analysis, male sex, unstable angina, hypertension, and chronic total occlusion were predictors of ISR. TLR4 genotypes were not associated with baseline or stimulated cytokine concentrations or with angiographic variables at follow-up.

Conclusions: In vitro cytokine response to LPS challenge is not increased in patients with ISR. Functionality of the TLR4 Asp299Gly polymorphism could not be demonstrated in this setting, and this polymorphism was not associated with angiographic outcome, calling into question its role in the progression of neointimal tissue growth.
Pricing of Conspicuous Goods: A Competitive Analysis of Social Effects
Authors: Amaldoss Wilfred , Jain Sanjay
Published: January 2005

Social needs play an important role in the purchase of conspicuous goods. In this article, the authors extend traditional economic models to accommodate social needs, such as desire for uniqueness and conformism, and examine their implications for pricing conspicuous goods. First, in the context of a duopoly, the authors identify the conditions under which the desire for uniqueness can increase demand among some consumers as the price of a product increases. Second, the authors show that though the desire for uniqueness leads to higher prices and firm profits, a desire for conformity leads to lower prices and profits. Third, the authors find that consumers purchase high-quality products not because of their desire for uniqueness but despite it. Finally, marketers of conspicuous goods may find it beneficial not to emphasize the functional differences among their products when the need for uniqueness is high. In a laboratory test, the authors find support for the claim that demand for a product among consumers who desire uniqueness may increase as its price increases.
Justification Effects on Consumer Choice of Hedonic and Utilitarian Goods
Authors: Okada Erica Mina
Published: January 2005

People want to have fun, and they are more likely to have fun if the situation allows them to justify it. This research studies how people's need for justifying hedonic consumption drives two choice patterns that are observed in typical purchase contexts. First, relative preferences between hedonic and utilitarian alternatives can reverse, depending on how the immediate purchase situation presents itself. A hedonic alternative tends to be rated more highly than a comparable utilitarian alternative when each is presented singly, but the utilitarian alternative tends to be chosen over the hedonic alternative when the two are presented jointly. Second, people have preferences for expending different combinations of time (effort) and money for acquiring hedonic versus utilitarian items. They are willing to pay more in time for hedonic goods and more in money for utilitarian goods. The author explores the topic through a combination of four experiments and field studies.
Who Advised the Hong Kong Government? The Politics of Absorption before and after 1997
Authors: Cheung Anthony B. L. , Wong Paul C. W.
Published: January 2005

This article explores the socioeconomic patterns of cooptation to advisory bodies and other political offices in Hong Kong during the colonial, transition, and post-colonial periods. Despite a substantial continuity in the composition of elites coopted, government/elites relations have changed because of the rise of a new form of functional-elite politics.
Fences and Neighbors: Segregation in 21st-Century America
Authors: Farley John E. , Squires Gregory D.
Published: January 2005

After more than three decades of fair housing laws, residential segregation is declining, but it remains pervasive. It undermines minority families' search for good jobs, quality schools, health care, and financial success. However, new organizing efforts, tools, and tactics offer hope for greater progress.
Grignard Reactions
Authors: Rakita Philip E.
Published: January 2005

The term
Grignard reaction
refers to both the preparation of a class of organomagnesium halide compounds and their subsequent reaction with a wide variety of organic and inorganic substrates.

The general sequence of the reactions is now embodied in the following generic forms, where RX = an organic halide (most typically a chloride or bromide, although fluorides can be induced to react); S = a coordinating solvent (such as an ether or an amine); and AZ = a substrate with an electronegative group, Z: RX + Mg + 
n
S → RMgX·S

n

RMgX·S

n

 + AZ → RAZMgX·S

n

RAZMgX·S

n

 → RA + ZMgX·S

n

.

The development of improved industrial procedures, including the substitution of tetrahydrofuran (THF) for diethyl ether and the demonstration that the less reactive, but significantly less expensive, vinyl and aryl chlorides could be successfully used, has greatly expanded the commercial possibilities of this reaction. In the flavor, fragrance, pharmaceutical, and fine chemical industries, its use can generally be regarded as routine.

The great value of the Grignard reaction to the synthetic chemist is its general applicability as a building block for an impressive range of structures and functional groups.
Polymethine Dyes
Authors: Tolmachev Aleksei I. , Il’chenko Andrei Ya.
Published: January 2005

This article contains basic information on the structure of polymethine dyes, their absorption and fluorescence spectra, and practical applications in various areas of science and engineering.
Ag‐Functionalized Carbon Molecular‐Sieve Membranes Based on Polyelectrolyte/Polyimide Blend Precursors
Authors: Barsema J. N. , van der Vegt N. F. A. , Koops G. H. , Wessling M.
Published: January 2005

We prepared dense flat‐sheet Ag‐functionalized carbon molecular‐sieve (CMS) membranes from blends of P84 co‐polyimide and a sulfonated poly(ether ether ketone) with a Ag+ counterion (AgSPEEK). These blends offer the possibility of producing new functionalized precursor structures, which were previously not possible, such as integrally skinned asymmetric hollow fibers. Membranes prepared at a pyrolysis end temperature of 800 °C showed a maximum permeability for all tested gases at a Ag content of approximately 2.5 wt.‐% (He permeability PHe = 465 Barrer (1 Barrer = 7.5 × 10–18 m2 s–1 Pa–1), P = 366 Barrer, P = 91.8 Barrer, P = 10.3 Barrer). The maximum achieved selectivity for O2 over N2 with CMS membranes based on these blends was α = 13.5 (Ag content: 4.5 wt.‐%, P = 52.7 Barrer). The CO2 over N2 selectivity reached a value of 48.9 (Ag content: 4.5 wt.‐%, P = 191 Barrer). These observations are explained by the formation of selective bypasses around Ag nanoclusters in the CMS matrix.
Air‐Pulse‐Drive Fabrication of Photonic Crystal Films of Colloids with High Spectral Quality
Authors: Kanai T. , Sawada T. , Toyotama A. , Kitamura K.
Published: January 2005

A fast and highly controllable method of fabricating large films of photonic crystals of colloids is reported. A charge‐stabilized colloidal suspension was run in a flat capillary driven by a pressure‐regulated air pulse. The colloidal crystal texture formed in the capillary was a sensitive function of air pressure. Above a critical pressure, the entire capillary was filled with a uniform single‐domain texture whose transmittance spectrum showed a high quality as a photonic crystal, i.e., excellent opacity at a photonic bandgap and high transparency at other wavelengths. The present method is easily applicable to industrial processes for mass production.
Enhancement of Field‐Effect Mobility Due to Surface‐Mediated Molecular Ordering in Regioregular Polythiophene Thin Film Transistors
Authors: Kim D. H. , Park Y. D. , Jang Y. , Yang H. , Kim Y. H. , Han J. I. , Moon D. G. , Park S. , Chang T. , Chang C. , Joo M. , Ryu C. Y. , Cho K.
Published: January 2005

With the aim of enhancing the field‐effect mobility by promoting surface‐mediated two‐dimensional molecular ordering in self‐aligned regioregular poly(3‐hexylthiophene) (P3HT) we have controlled the intermolecular interaction at the interface between P3HT and the insulator substrate by using self‐assembled monolayers (SAMs) functionalized with various groups (–NH2, –OH, and –CH3). We have found that, depending on the properties of the substrate surface, the P3HT nanocrystals adopt two different orientations—parallel and perpendicular to the insulator substrate—which have field‐effect mobilities that differ by more than a factor of 4, and that are as high as 0.28 cm2 V–1 s–1. This surprising increase in field‐effect mobility arises in particular for the perpendicular orientation of the nanocrystals with respect to the insulator substrate. Further, the perpendicular orientation of P3HT nanocrystals can be explained by the following factors: the unshared electron pairs of the SAM end groups, the π–H interactions between the thienyl‐backbone bearing π‐systems and the H (hydrogen) atoms of the SAM end groups, and interdigitation between the alkyl chains of P3HT and the alkyl chains of the SAMs.
From Blue to Red: Syntheses, Structures, Electronic and Electroluminescent Properties of Tunable Luminescent N,N Chelate Boron Complexes
Authors: Liu Q. D. , Mudadu M. S. , Thummel R. , Tao Y. , Wang S.
Published: January 2005

A comprehensive study of a series four‐coordinate boron compounds with the general formula of BPh2(N,N), where N,N are bidentate chelate ligands containing both neutral and negatively charged nitrogen donor atoms has been conducted. The structures of the boron complexes were examined via single‐crystal X‐ray diffraction. The series of molecules display bright luminescence with emission maxima λmax ranging from blue to red, depending on the nature of the N,N chelate ligand. The electronic effects and their consequences on the luminescent properties of the complexes due to the CH replacement of the chelate ligand by a nitrogen atom, the increase of conjugation, or the change of substituents on the chelate ligand have been examined using electrochemical analysis, UV‐visible, and fluorescence spectroscopic methods, and by molecular orbital calculations (Gaussian 98). Experimental data and MO calculation results established that the emission of this class of compounds is caused by π–π* transitions centered on the chelate ligand. Furthermore, the experimental and theoretical results consistently and conclusively established that electron withdrawing groups on the negatively charged N‐donor portion of the chelate ligand causes a decrease in the highest occupied molecular orbital (HOMO) energy level, thus increasing the energy gap. The CH replacement by a nitrogen atom on the negatively charged portion of the chelate ligand causes a dramatic decrease of the HOMO energy level, and the increase of conjugation in the chelate ligand significantly decreases the energy gap. Blue and red electroluminescent (EL) devices were fabricated successfully using two representative boron compounds from the series. The new boron compounds have been found to be able to function as both emitters and electron transport materials in EL devices.
Primary Cell Adhesion on RGD‐Functionalized and Covalently Crosslinked Thin Polyelectrolyte Multilayer Films
Authors: Picart C. , Elkaim R. , Richert L. , Audoin F. , Arntz Y. , Da Silva Cardoso M. , Schaaf P. , Voegel J.‐C. , Frisch B.
Published: January 2005

Polyelectrolyte multilayers (PEMs) are now widely used for biomedical applications. In this work, we investigated the primary osteoblast adhesion properties of PEMs of poly(L‐lysine) (PLL), poly(L‐glutamic acid) (PGA), poly(alginic acid) (Palg), and poly(galacturonic acid) (Pgal). In order to compensate for the poor adhesion of the as‐synthesized films, two kinds of film modifications were achieved: a purely physical modification by film crosslinking, and a chemical modification by grafting a arginine–glycine–aspartic acid (RGD) peptide to PGA. Crosslinking was performed using a water‐soluble carbodiimide in combination with N‐hydroxysulfosuccinimide (sulfo‐NHS) to induce amide formation. This reaction was followed by Fourier‐transform IR spectroscopy. For film functionalization, a 15‐amino‐acid peptide was grafted to PGA and deposited as the top layer of the film. PLL/PGA, PLL/Palg, and PLL/Pgal films were crosslinked or functionalized. The films were tested for both short‐term adhesion properties and long‐term proliferation of primary osteoblasts. Whereas the effect of film crosslinking on short‐term adhesion was moderate, it was much more important for the RGD‐functionalized films. On the other hand, the long‐term proliferation was the same or even higher for the crosslinked films as compared with the functionalized films. This effect was particularly enhanced for the PLL/Palg and PLL/Pgal films. Finally, we functionalized PLL/PGA that had been crosslinked prior to PGA‐RGD deposition. These architectures exhibited even higher short‐term adhesion and proliferation. These results clearly show the important role of the physical properties of the films, besides their chemical properties, for the modulation of primary cell‐adhesion behavior.
Solar‐Energy Conversion in TiO2/CuInS2 Nanocomposites
Authors: Nanu M. , Schoonman J. , Goossens A.
Published: January 2005

The search for low‐cost thin‐film solar cells, to replace silicon multi‐crystalline cells in due course, calls for new combinations of materials and new cell configurations. Here we report on a new approach, based on semiconductor nanocomposites, towards what we refer to as the three‐dimensional (3D) solar‐cell concept. Atomic layer chemical vapor deposition is employed for infiltration of CuInS2 inside the pores of nanostructured TiO2. In this way it is possible to obtain a nanometer‐scale interpenetrating network between n‐type TiO2 and p‐type CuInS2. X‐ray diffraction, Raman spectroscopy, photoluminescence spectroscopy, scanning electron microscopy, transmission electron microscopy, and current–voltage measurements are used to characterize the nanostructured devices. The 3D solar cells obtained show photovoltaic activity with a maximum monochromatic incident photon‐to‐current conversion efficiency of 80 % and have an energy‐conversion efficiency of 4 %.
Growth Control and Optics of Organic Nanoaggregates
Authors: Balzer F. , Rubahn H.‐G.
Published: January 2005

Light‐emitting organic nanofibers made of phenyl molecules like para‐hexaphenyl (p‐6P) and grown on muscovite mica form a model system well‐suited for the study of optics in the sub‐wavelength regime. We demonstrate that p‐6P nanofibers can be grown with high control of the morphology of individual nanoaggregates and also of the mutual alignment of aggregates by the use of appropriate growth conditions and substrate surfaces. The nanofibers can be detached from the substrate, thus allowing one to study the optical response under a huge variety of fundamentally different conditions, from individual floating aggregates to dense bunches of interacting aggregates. We show examples of linear and nonlinear optical properties of the blue‐light‐emitting aggregates and mention possible applications in future submicrometer‐sized optoelectronics.
Covalent Surface Chemistry of Single‐Walled Carbon Nanotubes
Authors: Banerjee S. , Hemraj‐Benny T. , Wong S. S.
Published: January 2005

In this review article, we explore covalent chemical strategies for the functionalization of carbon‐nanotube surfaces. In recent years, nanotubes have been treated as chemical reagents (be it inorganic or organic) in their own right. Indeed, from their inherent structure, one can view nanotubes as sterically bulky, π‐conjugated ligands, or conversely as electron‐deficient alkenes. Hence, herein we seek to understand, from a structural perspective, the breadth and types of reactions single‐walled nanotubes (SWNTs) can undergo in solution phase, not only at the ends and defect sites but also along the sidewalls. Controllable chemical functionalization suggests that the unique electronic and mechanical properties of SWNTs can be tailored in a determinable manner. Moreover, prevailing themes in nanotube functionalization have been involved with dissolution of tubes.
Induction period of CaCO3 interpreted by the Smoluchowski's coagulation theory
Authors: Tai C. Y. , Chien W. C. , Hsu J. P.
Published: January 2005

Smoluchowski's coagulation theory is adopted to estimate the induction period for the formation of the critical nuclei of CaCO3 in a supersaturated CaCl2‐Na2CO3 aqueous solution. The effects of the presence of impurity and crystal seeds, degree of supersaturation and operating temperature on the induction period are discussed. The association coefficient between two clusters is found to depend on both the degree of supersaturation and the temperature. The estimated activation energy for the association between two clusters is about 200 J/mol, which implies that the association between two clusters is of physical nature. It is found that the increase in the induction period with the presence of Mg2+ may be caused by an increase in the solid‐liquid interfacial energy, and a decrease in the association coefficient. Due to van der Waals attraction, the addition of crystal seeds increases the concentration of clusters near seed surface, and, thus, yields a shorter induction period. © 2005 American Institute of Chemical Engineers AIChE J, 51: 480–486, 2005
The Dihydroxyacetone Unit—A Versatile C3Building Block in Organic Synthesis
Authors: Enders Dieter , Voith Matthias , Lenzen Achim
Published: January 2005

Nature employs dihydroxyacetone phosphate (DHAP) as the donor component in various enzyme‐catalyzed aldol reactions. Probably the most significant example in this regard is photosynthesis, in whichD‐glucose, the most widespread natural product, is formed in just a few steps from DHAP. In recent years a number of synthetic equivalents of DHAP have been reported that deserve particular attention, as their applicability in organic synthesis is not limited to (stereoselective) aldol reactions. The power of these reagents has also been demonstrated convincingly in numerous other asymmetric electrophilic α‐substitution reactions in target‐oriented syntheses. Furthermore, the related 1,3‐dioxins are useful equivalents of 2‐substituted acrolein derivatives.