bluuebunny/crossref_metadata_2025 huggingface dataset:
Skid resistance loss of plastic-grooved concrete roadways
Authors: Lee S. W. , Chon B.-J.
Published: May 2008

An adequate level of skid resistance should be maintained during the entire service life of a roadway to provide safe driving conditions. To plan the appropriate timing of surface restoration, it is necessary to predict the change in skid resistance with time. However, no reliable method to predict the change in skid resistance has been suggested yet. In this study, a method to predict the rate of skid resistance loss for a plastic-grooved concrete roadway is suggested. Accelerated road-surface wearing tests were conducted to investigate the general pattern in the rate of skid resistance loss with the repetition of wheel pass. The relationship between skid resistance and the number of wheel passes is nonlinear and can be expressed linearly using a log–log scale. The rates of skid resistance loss to number of wheel passes of plastic-grooved concrete roadway differ section by section. The difference may be caused by the traffic mixture and climatic conditions of each section. Based on the analysis of the multi-year measurements of skid resistance and the potentially related factors obtained from 13 long-term roadway performance sections, a reliable equation to predict the rate of skid resistance loss for a particular plastic-grooved concrete roadway section is suggested.
Iberian rail: adding a new dimension to international travel
Authors: López Pita A. , Teixeira P. F. , Bachiller A. , Casas-Esplugas C. , Insa R.
Published: May 2008

The purpose of the present paper is to analyse the experience of operating the Madrid–Seville line from 1992 to 2005 and then to describe the scenario that will result from the entry into service of the Madrid–Barcelona and Barcelona–Perpignan routes, within the European context. During the next decade, after the new line between Avignon and Perpignan (approximately 250 km) has been constructed, it will be possible to establish a very long high-speed route between London and Seville in southern Spain (over 2700 km), and this is when the international dimension of high-speed rail transport and its role as a structural element within Europe will acquire a new practical significance.
Nested and teleconnected vulnerabilities to environmental change
Authors: Adger W Neil , Eakin Hallie , Winkels Alexandra
Published: May 2008

The vulnerability of distant peoples and places to global change in environment and society is nested and teleconnected. Here, we argue that such vulnerabilities are linked through environmental change process feedbacks, economic market linkages, and flows of resources, people, and information. We illustrate these linkages through the examples of the global transmission of severe acute respiratory syndrome (SARS) and the interdependent vulnerabilities and adaptations of coffee farmers in Vietnam and Mexico. These cases demonstrate that the vulnerability of specific individuals and communities is not geographically bounded but, rather, is connected at different scales, so that the drivers of their exposure and sensitivity are inseparable from large‐scale processes of sociocultural change and market integration. Aggregate outcomes of government policies, trends in global commodity markets, and even decisions by individuals to improve livelihood security can have negative repercussions, not only locally, through transformations of ecological systems and social relations, but also at larger scales.
Back to Basics: Bit Hydraulics
Authors: Wing C. S. , Brogdin M. J.
Published: May 2008

This paper describes the application of current technology to drill liner holes with conventional bits in Roger Mills County, Oklahoma. A re-evaluation of the parameters to drill liner holes (6" and above) with a conventional bit vs. a downhole motor has reduced drilling costs by $10 to $20 per foot. Using a good bit hydraulics program and the hand held computer has changed liner hole drilling standards for us in this area.
Modified acrylamide copolymers as flocculants for model aqueous suspensions
Authors: Drzycimska Agnieszka , Schmidt Beata , Spychaj Tadeusz
Published: May 2008

Modified acrylamide copolymers as flocculants for model aqueous suspensions

Two groups of acrylamide copolymers have been obtained by inverse microemulsion polymerization using: (i) acrylamide (AAm) with [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETAC) in the presence of sodium montmorillonite (MMT), and (ii) acrylamide with acrylic acid (AA) in the presence of aluminum sulphate. The received materials were characterised by capillary viscometry and the DSC methods, as well as the flocculation performances of the modified copolymers in the treatment of aqueous model suspensions of talc and calcium montmorillonite have been investigated. The effectiveness of the acrylamide flocculants was evaluated on the basis of the suspension extinction reduction and the sludge volume. The obtained results have been compared while using the modified materials and appropriate anionic and cationic AAm copolymers.
Polarization sensitivity of optical resonant dipole antennas
Authors: Fischer Holger , Martin Olivier J. F.
Published: May 2008

The polarization sensitivity of optical resonant dipole antennas is investigated numerically using the Green’s tensor technique. The electric field-intensity in the feed-gap of the antenna is calculated as function of the polarization of the incident field. A simple analytical model is proposed that matches the numerical data very well. While a very strong polarization sensitivity can be achieved for specific wavelengths, our results also indicate that there are situations where the antenna is not sensitive at all to the polarization. The role played by different plasmon resonances in the system is illustrated.
James Bond, Peter Pan, and A Sticky Night of Love: Irony and Masculinities in Amateur Animated Videos
Authors: Kendall Lori
Published: May 2008

This paper analyzes a genre of videos created and distributed online mostly by young men. These videos use a variety of playful and decontextualized images to present messages about masculinities. They both celebrate and denigrate some hegemonic and non-hegemonic masculine identities, while specifically making fun of homosexual males. As in previous studies of adolescent male discourse, the creators of these videos rely on irony and humor to distance themselves from potential claims of heterosexism and sexism. The particular fractured and frenetic style of the videos, and the ability to juxtapose conflicting images, make this somewhat easier to accomplish than it would be through text alone. The videos thus provide a safety net of deniability, allowing their creators to present multiple conflicting identities, while leaving the status quo intact.
A Room of (His) Own: Italian and Italian-American Male-Bonding Spaces and Homosociality
Authors: Weibel-Orlando Joan
Published: May 2008

This article focuses on underlying psychosocial rationales for perpetuating male-exclusive associations. Further explored is what establishment of such female-excluding male spaces reveal about relative parallels and/or differences in construction of gender identity and definitions of masculinity held by participating members of two male group—one in the Tuscany region of Central Italy, the other in southwestern Connecticut and made up largely of second and third generation Italian-Americans. Do these men, when in their own and exclusive company, act out too easily assumed stereotypes of Italian and Italian-American masculinities—hot tempered, competitive, prone to violence, mother adoring, Latin lovers? Or are their constructions of masculinity based on other and socioculturally and ethnohistorically tempered criteria of masculinity (Società, skill attainment, physical strength and separation from an impoverished past and the feminine)?
How Personal Control Mediates Suffering: Elderly Husbands' Narratives of Caregiving
Authors: Black Helen K. , Schwartz Abby J. , Caruso Christa J. , Hannum Susan M.
Published: May 2008

This article is based on ethnographic research that explored experiences of suffering in late life. From a group of 60 oldest-old (age 80 and above) male participants, four were primary, at-home caregivers for wives with dementia. Men's narratives showed the inter-relation between masculinities, a sense of personal control, and experiences of suffering within caregiving. Three thematic “tools” of control emerged as strategies men used to mediate their suffering: 1) the power of the little; 2) preserving self-identity and marriage-identity and, 3) finding purpose in the role of caregiver. We offer insight into the world of the oldest-old male caregiver through men's accounts of suffering, their daily tasks, thoughts about themselves as caregivers, and the manner in which they embody their masculinity in caregiving.
Infestation of trees by lianas in a tropical forest in Amazonian Peru
Authors: van der Heijden Geertje M.F. , Healey John R. , Phillips Oliver L.
Published: May 2008

Question:

In Amazonian moist forest, four questions arose: 1. Do tree species differ in their susceptibility to lianas? 2. What host tree traits (branch‐free bole height, growth rate, bark type, leaf length and adult stature) are correlated with the susceptibility of tree species to lianas infesting the trunk and the crown? 3. To what extent do spatial variables (proximity to liana‐infested trees and the light environment of the tree crown) affect the likelihood of liana infestation? 4. Are spatial variables or tree traits relatively more important in influencing the susceptibility of trees to lianas? We address all questions separately for trunk and crown infestation.

Location:

Tambopata Nature Reserve, Peru.

Methods:

We collected information on liana infestation, tree morphological traits, growth, light‐environment and position for 3675 trees in seven 1‐ha permanent sample plots. We separated trunk from crown infestation and used correlation and logistic regression analyses for tree species and individual tree‐level analyses, respectively.

Results:

Half of all trees were colonised by at least one liana. Of 41 relatively common dicot tree species, at least five have significantly greater and three significantly lower crown infestation rates than expected by chance. Trunk and crown infestation are influenced by different host traits – trunk infestation was only affected by bark type, while crown infestation is reduced when trees are fast‐growing, tall, have low‐density wood, long branch‐free boles and long leaves. The likelihood of both trunk and crown infestation increases for trees growing in close proximity to another liana‐infested tree, but is invariant with the light environment of tree crowns.

Conclusion:

Crown and trunk infestation have not been properly distinguished before; it is important to do so as the factors determining the different modes of infestation differ fundamentally. The association between crown infestation and tree traits suggests that increases in liana dominance in Amazonian forests could cause changes in forest composition, including favouring faster growing tree species with low density wood, potentially reducing the carbon stored by mature forests.
A Statistical Analysis of the Robustness of Alternate Genetic Coding Tables
Authors: Kurnaz Mehmet Levent , Kurnaz Isil Aksan
Published: May 2008

The rules that specify how the information contained in DNA is translated into amino acid “language” during protein synthesis are called “the genetic code”, commonly called the “Standard” or “Universal” Genetic Code Table. As a matter of fact, this coding table is not at all “universal”: in addition to different genetic code tables used by different organisms, even within the same organism the nuclear and mitochondrial genes may be subject to two different coding tables. Results In an attempt to understand the advantages and disadvantages these coding tables may bring to an organism, we have decided to analyze various coding tables on genes subject to mutations, and have estimated how these genes “survive” over generations. We have used this as indicative of the “evolutionary” success of that particular coding table. We find that the “standard” genetic code is not actually the most robust of all coding tables, and interestingly, Flatworm Mitochondrial Code (FMC) appears to be the highest ranking coding table given our assumptions. Conclusions It is commonly hypothesized that the more robust a genetic code, the better suited it is for maintenance of the genome. Our study shows that, given the assumptions in our model, Standard Genetic Code is quite poor when compared to other alternate code tables in terms of robustness. This brings about the question of why Standard Code has been so widely accepted by a wider variety of organisms instead of FMC, which needs to be addressed for a thorough understanding of genetic code evolution.
Purification and Preliminary Crystallographic Analysis of a New Lys49-PLA2 from B. Jararacussu
Authors: Dos Santos Marcelo L. , Fagundes Fábio H. R. , Teixeira Bruno R. F. , Toyama Marcos H. , Aparicio Ricardo
Published: May 2008

BjVIII is a new myotoxic Lys49-PLA2 isolated from Bothrops jararacussu venom that exhibits atypical effects on human platelet aggregation. To better understand the mode of action of BjVIII, crystallographic studies were initiated. Two crystal forms were obtained, both containing two molecules in the asymmetric unit (ASU). Synchrotron radiation diffraction data were collected to 2.0 °A resolution and 1.9 °A resolution for crystals belonging to the space group P212121 (a = 48:4 A° , b = 65:3 A° , c = 84:3 A° ) and space group P3121 (a = b = 55:7 A° , c = 127:9 A° ), respectively. Refinement is currently in progress and the refined structures are expected to shed light on the unusual platelet aggregation activity observed for BjVIII.
Carbon‐Carbon Double Bond versus Carbonyl Group Hydrogenation: Controlling the Intramolecular Selectivity with Polyaniline‐Supported Platinum Catalysts
Authors: Steffan Martin , Klasovsky Florian , Arras Jürgen , Roth Christina , Radnik Jörg , Hofmeister Herbert , Claus Peter
Published: May 2008

The use of polyaniline (PANI) as catalyst support for heterogeneous catalysts and their application in chemical catalysis is hitherto rather poorly known. We report the successful synthesis of highly dispersed PANI‐supported platinum catalysts (particle sizes between 1.7 and 3.7 nm as revealed by transmission electron microscopy, TEM) choosing two different approaches, namely (i) deposition‐precipitation of H2PtCl6 onto polyaniline, suspended in basic medium (DP method) and, (ii) immobilization of a preformed nanoscale platinum colloid on polyaniline (sol‐method). The PANI‐supported platinum catalysts were applied in the selective hydrogenation of the α,β‐unsaturated aldehyde citral. In order to benchmark their catalytic performance, citral hydrogenation was also carried out by using platinum supported on the classical support materials silica (SiO2), alumina (Al2O3), active carbon and graphite. The relations of the structural characteristics and surface state of the catalysts with respect to their hydrogenation properties have been probed by EXAFS and XPS. It is found that the DP method yields chemically prepared PtO2 on polyaniline and, thus, produces a highly dispersed and immobilized Adams catalyst (in the β‐PtO2 form) which is able to efficiently hydrogenate the conjugated CC bond of citral (selectivity to citronellal=87%), whereas reduction of the CO group occurs with polyaniline‐supported platinum (selectivity to geraniol/nerol=78%) prepared via the sol‐method. The complete reversal of the selectivity between the preferred hydrogenation of the conjugated CC or CO group is not only particularly useful for the selective hydrogenation of α,β‐unsaturated aldehydes but also unveils the great potential of conducting polymer‐supported precious metals in the field of hitherto barely investigated chemical catalysis.
Highly Enantioselective Construction of a Quaternary Carbon Center of Dihydroquinazoline by Asymmetric Mannich Reaction and Chiral Recognition
Authors: Jiang Biao , Dong Jia Jia , Si Yu Gui , Zhao Xiao Long , Huang Zuo Gang , Xu Min
Published: May 2008

The highly enantioselective construction of a quaternary carbon center of dihydroquinazoline by an asymmetric Mannich reaction and chiral recognition are described. The key transformation was to establish the chiral trifluoromethyl quaternary carbon center by a diamine‐Brønsted acid‐catalyzed enantioselective and regioselective Mannich reaction of a methyl ketone and 4‐trifluoromethyldihydroquinazoline. An unusual phenomenon of self‐discrimination of enantiomers in hydrogen‐bonded dimers was observed. A valuable intermediate was transformed into the enantiopure HIV reverse transcriptase inhibitor DPC 083 (>99.9 ee) simply by reduction of the carbonyl group and elimination of the hydroxy group in hexamethylphosphoric tramide (HMPA).
Rhodium‐Catalyzed Highly Regioselective Hydroformylation‐Hydrogenation of 1,2‐Allenyl‐Phosphine Oxides and ‐Phosphonates
Authors: Guo Hao , Ma Shengming
Published: May 2008

The rhodium‐catalyzed hydroformylation‐hydrogenation of 1,2‐allenyl‐phosphine oxides and ‐phosphonates is reported in this paper. The regioselectivity was well controlled, affording only saturated linear γ‐phosphinyl aldehydes under the standard conditions: (carbonyl)tris(triphenylphosphine)‐rhodium hydride [RhH(CO)(PPh3)3] (3 mol%), triphenylphosphine (PPh3) (10 mol%), carbon monoxide (CO) (2.4×106 Pa), hydrogen (H2) (subsequently charged to 4.8×106 Pa), toluene, 100 °C, 24 h.
Unmodified Nano‐Powder Magnetite Catalyzes a Four‐ Component Aza‐Sakurai Reaction
Authors: Martínez Ricardo , Ramón Diego J. , Yus Miguel
Published: May 2008

A new catalyst for an old material: magnetite is an excellent Lewis acid catalyst for the four‐component aza‐Sakurai reaction. The process could be repeated up to 15‐times without losing effectiveness, with the catalyst recycling being as easy as the use of a simple magnet. The catalyst is selective and could discriminate between aldehyde and ketone functionalities, catalyzing first the reaction with the higher electrophilic aldehyde.
Partial HLA matching and RH incompatibility resulting in graft versus host reaction and Evans syndrome after liver transplantation
Authors: Grosskreutz Celia , Gudzowaty Oksana , Shi Patricia , Rodriguez‐Laiz Gonzalo , Malone Adriana , Isola Luis
Published: May 2008

We report a case of a 67‐year‐old male who underwent OLT from a deceased, sex‐matched donor. Two months later he developed Evans syndrome and GVHD of the skin. Donor and recipient were matched for HLA‐A and ‐B loci in the direction of rejection but mismatched in the direction of GVHD and fully mismatched for DRB1. These mismatches were permissible for engraftment of donor T‐cells but led to GVHD. Chimerism appeared restricted to the T‐cell compartment. In this case, partially matched passenger lymphocytes triggered a graft versus host reaction. In addition, alloantibodies caused cytopenias that improved after immunosuppression. HLA typing was critical in confirming this rare diagnosis and elucidating its cause. Recipients of solid organs from donors that are partially matched in the direction of rejection may need to be closely monitored for GVHD. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Caudal dysgenesis, sirenomelia, and situs inversus totalis: A primitive defect in blastogenesis
Authors: Rougemont Anne‐Laure , Bouron‐Dal Soglio Dorothée , Désilets Valérie , Jovanovic Mubina , Perreault Gilles , Laurier Oligny Luc , Fournet Jean‐Christophe
Published: May 2008

Caudal dysgenesis (CD) constitutes a heterogeneous spectrum of congenital caudal anomalies, including varying degrees of agenesis of the vertebral column, as well as anorectal and genitourinary anomalies. Sirenomelia, characterized by a fusion of the lower limbs, could represent the most severe end of this spectrum. The two main debated pathogenic hypotheses are an aberrant vascular supply versus a primary axial mesoderm defect. We present the autopsy findings of two fetuses of non‐diabetic mothers, with normal karyotype. Both fetuses presented situs inversus associated with a CD, in one case consisting of sirenomelia, establishing a very rare association profile that might be random. This association also suggests the occurrence of a common pathogenic mechanism, in accordance to recent genetic data, such as displayed in the Kif3A murine mutation phenotype. Some cases of sirenomelia and CD could represent developmental field defects of blastogenesis involving the caudal mesoderm, rather than being related to vascular insufficiency. © 2008 Wiley‐Liss, Inc.
Deletion of 8p23.1 with features of Cornelia de Lange syndrome and congenital diaphragmatic hernia and a review of deletions of 8p23.1 to 8pter ? A further locus for Cornelia de Lange syndrome
Authors: Baynam Gareth , Goldblatt Jack , Walpole Ian
Published: May 2008

Cornelia de Lange syndrome (CdLS) is characterized by facial dysmorphism; hirsutism; internal organ anomalies, including diaphragmatic hernia, and limb defects. While causative mutations in three genes have been identified the etiology of a significant number of cases remains unknown. We report on a child with an 8p23.1 deletion with features of CdLS and congenital diaphragmatic hernia. We review cases with cytogenetic anomalies involving 8p23.1, discuss a potential relationship between 8p23.1 deletions and CdLS and suggest a novel candidate gene for CdLS—Tankyrase 1. © 2008 Wiley‐Liss, Inc.
GAPO syndrome: Three new Brazilian cases, additional osseous manifestations, and review of the literature
Authors: Goloni‐Bertollo Eny Maria , Ruiz Mariangela Torreglosa , Goloni Cristina B. Vendrame , Muniz Marcos Pontes , Valério Nelson Iguimar , Pavarino‐Bertelli Érika Cristina
Published: May 2008

The GAPO syndrome is an extremely rare autosomal recessive disease that presents as main characteristics evident growth retardation, alopecia, pseudoanodontia, progressive optic atrophy and a typical face. Until now, only 30 patients have been reported in the medical literature (nine of them from Brazil, including the three cases described in the present article). This study describes three siblings with GAPO syndrome, two female and one male, the children of consanguineous parents (first‐degree cousins, inbreeding F = 1/16), who are older than the previously described patients, presenting the characteristic phenotype besides serious bone alterations in the lower limbs, which had not yet been observed. © 2008 Wiley‐Liss, Inc.
The influence of basal metabolic rate on blood pressure among indigenous Siberians
Authors: Snodgrass J. Josh , Leonard William R. , Sorensen Mark V. , Tarskaia Larissa A. , Mosher M.J.
Published: May 2008

Hypertension is an important global health issue and is currently increasing at a rapid pace in most industrializing nations. Although a number of risk factors have been linked with the development of hypertension, including obesity, high dietary sodium, and chronic psychosocial stress, these factors cannot fully explain the variation in blood pressure and hypertension rates that occurs within and between populations. The present study uses data collected on adults from three indigenous Siberian populations (Evenki, Buryat, and Yakut [Sakha]) to test the hypothesis of Luke et al. (Hypertension 43 (2004) 555–560) that basal metabolic rate (BMR) and blood pressure are positively associated independent of body size. When adjusted for body size and composition, as well as potentially confounding variables such as age, smoking status, ethnicity, and degree of urbanization, BMR was positively correlated with systolic blood pressure (SBP; P < 0.01) and pulse pressure (PP; P < 0.01); BMR showed a trend with diastolic blood pressure (DBP; P = 0.08). Thus, higher BMR is associated with higher SBP and PP; this is opposite the well‐documented inverse relationship between physical activity and blood pressure. If the influence of BMR on blood pressure is confirmed, the systematically elevated BMRs of indigenous Siberians may help explain the relatively high blood pressures and hypertension rates documented among native Siberians in the post‐Soviet period. These findings underscore the importance of considering the influence of biological adaptation to regional environmental conditions in structuring health changes associated with economic development and lifestyle change. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Influence of the amount of ferromagnetic addition on the rheological properties of spinning solutions, the structure, the strength, and thermal properties of polyacrylonitrile fibres
Authors: Mikołajczyk Teresa , Janowska Grażyna , Wójcik Mariusz , Boguń Maciej , Kurzak Andrzej
Published: May 2008

The rheological properties of spinning solutions of polyacrylonitrile in dimethyl formamide (DMF) containing various amounts of a ferromagnetic nanoaddition were investigated. The porous structure, the strength and thermal properties of fibers obtained from these solutions were assessed, as well as the uniformity of the nanoaddition distribution on the fiber surface was estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of initiators on the cure kinetics and mechanical properties of vinyl ester resins
Authors: Li Peng , Yu Yunhua , Yang Xiaoping
Published: May 2008

Initiators play an important role in the curing of vinyl ester resins. In this study, two kinds of initiators were used to investigate the effects of initiator systems on the cure kinetics, microstructure, and mechanical properties of vinyl ester resins. The reaction kinetics, investigated with isothermal differential scanning calorimetry (DSC), showed that the combination of different kinds of initiators could significantly decrease the induction times and exothermal peak times and increase the amount of isothermal reaction heat in comparison with a single‐initiator system. The residual heat of the isothermal cure of vinyl ester resins, obtained by DSC, demonstrated the existence of microheterogeneity in the cured resins. The DSC data also showed that the highly crosslinked phase (the microgel phase) was more perfect for the resins cured with an initiator‐combination system. No significant difference was observed in the mechanical properties of resins cured under different conditions, whereas the cure temperature had a great effect on the mechanical properties of cured resins. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Silane‐crosslinked ethylene–octene copolymer blends: Thermal aging and crystallization study
Authors: Sirisinha Kalyanee , Chimdist Sirinya
Published: May 2008

Thermally stable materials can be achieved by crosslinking. This article presents the thermal aging and thermal energy storage properties of ethylene–octene copolymer (EOR) and low‐density polyethylene (LDPE) blends as affected by silane crosslinking. Fourier transform infrared spectroscopy revealed a similar degree of silane grafting among the various blend compositions. However, the highest crosslink content was observed in EOR, whereas the lowest was found for LDPE. From melting temperature and heat of fusion data, a linear relationship between the amount of the crystalline component and the crosslink content was found. The decrease in crystallinity due to crosslinking was very limited, which implied a high thermal energy storage capacity of the silane‐crosslinked products and their good mechanical properties at room temperature. Furthermore, a strong ability to retain the properties after thermal aging indicated good thermal stability of the materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Toughening of polyamide 6 with a maleic anhydride functionalized acrylonitrile–butadiene–styrene copolymer
Authors: Xu X. Y. , Sun S. L. , Chen Z. C. , Zhang H. X.
Published: May 2008

Maleic anhydride functionalized acrylonitrile–butadiene–styrene (ABS‐g‐MA) copolymers were prepared via an emulsion polymerization process. The ABS‐g‐MA copolymers were used to toughen polyamide 6 (PA‐6). Fourier transform infrared results show that the maleic anhydride (MA) grafted onto the polybutadiene phase of acrylonitrile–butadiene–styrene (ABS). Rheological testing identified chemical reactions between PA‐6 and ABS‐g‐MA. Transmission electron microscopy and scanning electron microscopy displayed the compatibilization reactions between MA of ABS‐g‐MA and the amine and/or amide groups of PA‐6 chain ends, which improved the disperse morphology of the ABS‐g‐MA copolymers in the PA‐6 matrix. The blends compatibilized with ABS‐g‐MA exhibited notched impact strengths of more than 900 J/m. A 1 wt % concentration of MA in ABS‐g‐MA appeared sufficient to improve the impact properties and decreased the brittle–ductile transition temperature from 50 to 10°C. Scanning electron microscopy results show that the shear yielding of the PA‐6 matrix was the major toughening mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermoplastic elastomers based on epoxidized natural rubber and high‐density polyethylene blends: Effect of blend compatibilizers on the mechanical and morphological properties
Authors: Nakason Charoen , Jarnthong Methakarn , Kaesaman Azizon , Kiatkamjornwong Suda
Published: May 2008

Epoxidized natural rubber (ENR) with a level of epoxide groups of 20 mol % was prepared via the performic epoxidation method. It was then used to blend with high‐density polyethylene (HDPE) at various blend ratios. Three types of blend compatibilizers were prepared. These included a graft copolymer of HDPE and maleic anhydride (MA; i.e., HDPE‐g‐MA) and two types of phenolic modified HDPEs using phenolic resins SP‐1045 and HRJ‐10518 (i.e., PhSP‐PE and PhHRJ‐PE), respectively. We found that the blend with compatibilizer exhibited superior tensile strength, hardness, and set properties to that of the blend without compatibilizer. The ENR and HDPE interaction via the link of compatibilizer molecules was the polar functional groups of the compatibilizer with the oxirane groups in the ENR molecules. Also, another end of the compatibilizer molecules (i.e., HDPE segments) was compatibilizing with the HDPE molecules in the blend components. The blend with compatibilizer also showed smaller phase morphology than the blend without compatibilizer. Among the three types of the blend compatibilizer, HDPE‐g‐MA provided the blend with the greatest strength and hardness properties but the lowest set properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of α‐butyl‐ω‐N,N‐dihydroxyethylaminopropylpolydimethylsiloxane
Authors: Yu Yitao , Zhang Qingsi , Zhang Meng , Sun Haifeng
Published: May 2008

α‐Butyl‐ω‐N,N‐dihydroxyethylaminopropylpolydimethylsiloxane, a monotelechelic polydimethylsiloxane with a diol‐end group, which is used to prepare polyurethane–polysiloxane graft polymer, was successfully synthesized. The preparation included five steps, which are hydroxyl protection, alkylation, anionic ring‐opening polymerization, hydrosilylation, and deprotection. The products were characterized by FTIR, GC, LC‐MS, 1H NMR, and elemental analysis. The results showed that each step was successfully carried out and the targeted products were synthesized in all cases. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis, characterization, and kinetics study of thermal decomposition of epoxidized soybean oil acrylate
Authors: Behera D. , Banthia A. K.
Published: May 2008

The synthesis of epoxidized soybean oil acrylate (ESOA) from epoxidized soybean oil (ESO) had been carried out by reacting acrylic acid with the oxirane group in ESO. The acrylated ESO products were characterized using a variety of analytical techniques. The oxygen value, iodine value, and acid value were obtained to know the amount of unsaturation in the synthesized product. Infrared and proton NMR spectra were carried out to confirm the participation of oxirane group in the acrylation reaction. Free‐radical initiators, benzoyl peroxide and tertiary butyl peroxy benzoate, were used for the curing of ESOA resin. Thermal decomposition kinetics of ESOA was studied by the methods of Ozawa, Kissinger, and Horowitz‐Metzger, and the kinetic parameters were compared. The thermal decomposition data of the cured ESOA resin was analyzed by thermogravimetric analysis (TGA) at different heating rates. TG curves showed that the thermal decomposition of the ESOA system occurred in one stage. The apparent activation energies determined by the Ozawa, Kissinger, and Horowitz‐Metzger methods are 122.69, 95.347, and 126.20 kJ/mol, respectively. The results show that there was a reasonably good agreement between the calculated activation energies for stage one in the above methods. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Unforseen factors influencing Fe(III)‐containing cations sorption on strongly basic anion exchangers
Authors: Gutsanu Vasile , Schitco Cristina , Drutsa Raisa
Published: May 2008

The sorption and partial destruction of the Fe(III)‐containing compounds in the aqueous medium in strongly basic anion exchangers AV‐17 and Varion‐AD phase have been investigated. It is shown that partial destruction of the Fe (III) compounds in acidulated water (pH = 2) and in K2SO4, Fe2(SO4)3 solutions takes place. With increasing of temperature up to 50°C, the desorption degree of the iron ions from polymer phase decreases. In dried polymer, the structural and electronic state of iron compounds, according to their magnetic susceptibility, remains stable for a long time. The sorption of the Fe(III)‐containing cations at 50°C during 12 h depends essentially on the sizes of polymer granules. Sorption increases with growing of polymer granules. For comparison of sorptional capacities, the sorption of Fe(III)‐containing cations was determined on different cation and anion exchangers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of fluoropolymers with intrinsic microporosity and their hydrogen adsorption studies
Authors: Makhseed Saad , Samuel Jacob , Bumajdad Ali , Hassan Mohammed
Published: May 2008

Microporous polymers with rigid organic architecture offer a wide range of efficient on board hydrogen storage at low temperature. The fluoropolymers with intrinsic microporosity (MP1 and MP2) were synthesized and characterized. Characterization technique such as high resolution transmission electron microscopy (HRTEM) revealed that the highly stable microporous structure of MP2 was composed of nanoporous frame work which was further supported by the computational study. The high surface area and microporosity of the polymers were estimated by measuring the N2 gas adsorption. The MP1 and MP2 exhibit BET surface areas 666 and 1050 m2/g respectively. The micropore size distribution curves show a higher concentration of subnanometer pores. The hydrogen storage capacity of the prepared polymers are promising and the performance relative to other microporous polymers is comparable. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Enhancing the electroluminescence performances of blue polymer light emitting devices via carriers transporting materials incorporation
Authors: Lee Rong‐Ho , Hsu Hsin‐Fang , Chan Li‐Hsin , Chen Chin‐Ti
Published: May 2008

A series of polymer light emitting devices (PLEDs) based on the composite films of N‐arylbenzimidazoles trimer (TPBI), poly (n‐vinylcarbazole) (PVK), and a triarylaminooxadiazole‐containing tetraphenylsilane light emitting polymer (PTOA) were investigated. Electroluminescence (EL) performance is enhanced with doped TPBI into the light‐emitting layer for the PTOA‐based devices. A deep blue emission (Commission Internationale de L'Eclairage (CIEx,y) corodinates (0.16,0.06)) is obtained for the TPBI‐PTOA‐based device. Brightness and current efficiency of the TPBI‐PTOA‐based device can be as high as 961 cd/m2 and 1.85 cd/A, respectively. The EL performances of TPBI‐PTOA composite film‐based devices are further enhanced by inserting a TPBI layer into the light emitting layer and cathode interface for a better electron and hole charge balance. Doping TPBI into the light‐emitting layer of PVK‐PTOA is not favorable for enhanced EL performances. Brightness and current efficiency reduced with increasing TPBI content for the TPBI‐PVK‐PTOA‐based devices. Similar results are obtained for devices based on the TPBI‐PVK‐PTOA/TPBI bi‐layer composite solid film. Morphology and charge balance effects on EL performances of TPBI‐PTOA and TPBI‐PVK‐PTOA composite films based PLEDs are discussed in detail. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Amorphous copolyesters based on 1,3/1,4‐cyclohexanedimethanol: Synthesis, characterization and properties
Authors: Tsai Yuhsin , Fan Cheng‐Hsing , Hung Chi‐Yuan , Tsai Fuu‐Jen
Published: May 2008

Two series of amorphous copolyesters, PETGN and PETGS, were synthesized by the copolymerization of 2,6‐naphthalene dicarboxylic acid (NDA) (0–40%), succinic acid (SA) (0–40%), 1,3/1,4‐cyclohexanedimethanol (1,3/1,4‐CHDM) (10–50%), ethylene glycol (EG), and terephthalic acid (TPA). The compositions and molecular weights of the copolyesters were determined by 1H NMR spectroscopy and viscometry, respectively. The thermal behaviors were studied over the entire range of copolymer compositions, using DSC and TGA. The optical characteristics, heat‐shrinkable effects and tensile properties of these polymers were also determined. Experimental results indicated that the thermal, optical, tensile, and shrinkage properties of PETGN and PETGS were functions of NDA or SA content. DSC and X‐ray analysis demonstrated that both PETGN and PETGS series were amorphous. Incorporating NDA and SA influenced the Tg values of those polymers, from about 37°C for PETG30S40 to 89°C for PETG30N40. Furthermore, the shrinkage of these amorphous copolyesters was more than 40% when the heating temperature was higher than the corresponding Tg. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ontology‐based evaluation of organizational memory
Authors: Weinberger Hadas , Te'eni Dov , Frank Ariel J.
Published: May 2008

In this article we offer a new approach to evaluating Organizational Memory (OM). Our proposed evaluation methodology, named KnowledgeEco, is based on an ontology for the domain of OM. Its key steps are: 1) mapping the OM in the evaluated organization onto the ontology concepts; 2) noting which entities from the ontology are missing in the OM; and 3) applying a series of rules that help assess the impact of the OM on organizational learning. This systematic evaluation thus helps to propose ways to improve the evaluated OM.

We present three case studies that demonstrate the feasibility of KnowledgeEco for evaluating OM and for suggesting improvements. We also identify some weaknesses in the OMs common to the three organizations cited in the case studies. Finally, we discuss how the KnowledgeEco ontology‐based methodology establishes utility and contributes to further research in the field of OM.
Co‐word analysis using the Chinese character set
Authors: Leydesdorff Loet , Zhou Ping
Published: May 2008

Until recently, Chinese texts could not be studied using co‐word analysis because the words are not separated by spaces in Chinese (and Japanese). A word can be composed of one or more characters. The online availability of programs that separate Chinese texts makes it possible to analyze them using semantic maps. Chinese characters contain not only information but also meaning. This may enhance the readability of semantic maps. In this study, we analyze 58 words which occur 10 or more times in the 1,652 journal titles of the China Scientific and Technical Papers and Citations Database. The word‐occurrence matrix is visualized and factor‐analyzed.
Novel Ascorbic Acid Based Ionic Liquids for the In Situ Synthesis of Quasi‐Spherical and Anisotropic Gold Nanostructures in Aqueous Medium
Authors: Dinda Enakshi , Si Satyabrata , Kotal Atanu , Mandal Tarun K.
Published: May 2008

A series of newly designed ascorbic acid based room temperature ionic liquids were successfully used to prepare quasi‐spherical and anisotropic gold nanostructures in an aqueous medium at ambient temperature. The synthesis of these room temperature ionic liquids involves, first, the preparation of a 1‐alkyl (such as methyl, ethyl, butyl, hexyl, octyl, and decyl) derivative of 3‐methylimidazolium hydroxide followed by the neutralization of the derivatised product with ascorbic acid. These ionic liquids show significantly better thermal stability and their glass transition temperature (Tg) decreases with increasing alkyl chain length. The ascorbate counter anion of these ionic liquids acts as a reducing agent for HAuCl4 to produce metallic gold and the alkylated imidazolium counter cation acts as a capping/shape‐directing agent. It has been found that the nature of the ionic liquids and the mole ratio of ionic liquid to HAuCl4 has a significant effect on the morphology of the formed gold nanostructures. If an equimolar mixture of ionic liquid and HAuCl4 is used, predominantly anisotropic gold nanostructures are formed and by varying the alkyl chain length attached to imidazolium cation of the ionic liquids, various particle morphologies can formed, such as quasispherical, raspberry‐like, flakes or dendritic. A probable formation mechanism for such anisotropic gold nanostructures has been proposed, which is based on the results of some control experiments.
The Synthesis of Di(aminoguanidine) 5‐Nitroiminotetrazolate: Some Diprotic or Monoprotic Acids as Precursors of Energetic Salts
Authors: Gao Haixiang , Huang Yangen , Ye Chengfeng , Twamley Brendan , Shreeve Jean'ne M.
Published: May 2008

Syntheses of salts with 4,6‐bis(nitroimino)‐1,3,5‐triazinan‐2‐one (DNAM), 3,5‐dinitro‐1,2,4‐cyclopentanetrione (DDCP), 3‐nitroiminotriazolate, and 5‐nitroiminotetrazolate as anions yielded moderately dense nitro‐containing energetic salts that are thermally stable to >200 °C (measured by thermogravimetric analysis). Di(aminoguanidine) 5‐nitroiminotetrazolate (8) crystallizes in the monoclinic space group P2(1)/c with an essentially planar 5‐nitroiminotetrazolate dianion. Based on experimental and calculated densities, and theoretical calculations carried out by using the Gaussian 03 suite of programs, all of the salts have calculated detonation pressures and velocities that exceed those of 2,4,6‐trinitrotoluene (TNT) and a few have values that approach those of triaminotrinitrobenzene (TATB).
Enhanced Iodide Sequestration by 3‐Biphenyl‐5,6‐dihydroimidazo[2,1‐b]thiazole in Sodium/Iodide Symporter (NIS)‐Expressing Cells
Authors: Lecat‐Guillet Nathalie , Ambroise Yves
Published: May 2008

The ability of the sodium/iodide symporter (NIS) to take up iodide has long provided the basis for cytoreductive gene therapy and cancer treatment with radioiodide. One of the major limitations of this approach is that radioiodide retention in NIS‐expressing cells is not sufficient for their destruction. We identified and characterized a small organic molecule capable of increasing iodide retention in HEK293 cells permanently transfected with human NIS cDNA (hNIS‐HEK293) and in the rat thyroid‐derived cell line FRTL‐5. In the presence of 3‐biphenyl‐4′‐yl‐5,6‐dihydroimidazo[2,1‐b]thiazole (ISA1), the transmembrane iodide concentration gradient was increased up to 4.5‐fold. Our experiments indicate that the imidazothiazole derivative acts either by inhibiting anion efflux mechanisms, or by promoting the relocation of iodide into subcellular compartments. This new compound is not only an attractive chemical tool to investigate the mechanisms of iodide flux at the cellular level, but also opens promising perspectives in the treatment of cancer after NIS gene transfer.
Characteristics of the original patient navigation programs to reduce disparities in the diagnosis and treatment of breast cancer
Authors: Vargas Roberto B. , Ryan Gery W. , Jackson Catherine A. , Rodriguez Rian , Freeman Harold P.
Published: May 2008

BACKGROUND.

Patient navigation is an intervention developed to reduce disparities in cancer care that is being widely replicated and receiving considerable support for demonstration projects and research to test its effectiveness. In the current study, the authors present an in‐depth descriptive analysis of the original patient navigation programs to inform current and future program development.

METHODS.

A qualitative multistakeholder case study using interviews and site visits of the first patient navigation site and 2 sites subsequently developed by the leadership of the original site were evaluated.

RESULTS.

At these sites, patient navigation is a system, as opposed to a person, comprised primarily of navigators and directors that work together to remove barriers and facilitate access in a well‐defined course of care; navigators were from the community or were culturally similar to the patient population served but were also paid employees of the clinical care site with detailed knowledge of the clinical course patients must traverse to complete care plans. Directors had administrative authority over the clinical facility and social capital across institutions, and communicated regularly and openly with navigators to implement system level changes to remove barriers to care. Contextual factors such as policies supporting breast cancer care also influenced the implementation of these programs.

CONCLUSIONS.

The first patient navigation programs combined community and culturally sensitive care‐coordination with aspects of disease management programs to reduce racial, ethnic, and poverty‐driven disparities in care. Future efforts to replicate and evaluate patient navigation should take into account these unique aspects of the original patient navigation programs. Cancer 2008. © 2008 American Cancer Society.