bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rheological 3-D Modeling of Scuffing for the EP-Additive Condition
Authors: Escobar Jaramillo EF , Escobar López CE 
Published: March 2005

Abstract
A rheology-based new model for predicting the scuffing limit in heavily loaded contacts, concerned especially with effects of EP-Additive Oil (Antiwearbasis Sulfure phosphore Zinc Nitrogen and Zincdithio phosphare) is developed here. The theoretical framework is sustained on the main assumption that all of the effects of additives can be modeled by the use of a combined friction-temperature variable, introduced in the theoretical known Blok's calculating criterion. The analytical step-jump method3 is used to expand the rearranged form of Blok's Flash Temperature expression, to yield a constitutive integral equation in order to describe a generalized friction process. The particular solution found is assumed to be representative for the rheological behavior of contacts, in the Additive Containing Condition (ACC), thus representing the linear step response contribution of protective layers due to tribochemical action. The improvement of the scuffing capacity with speed is influenced radically by the derived thermorheological friction-function, which at least turns out to be explicitly a function of the sliding speed. Physically, the friction-function represents the rheological response of the lubricated contact to the operating conditions. Mathematically, it is equivalent to the relaxation modulus in viscoelasticity. Thereafter, the scuffing capacity depends on the sliding speed as a dominant variable and markedly on two experimental response coefficients containing all the tribology of the model. Additionally, a short and economical method for determining experimentally the scuffing limit is suggested for the FZG-rig [33]. This study is concerned with Blok's calculating method and its extension to the ACC [3] and also with the view to incorporate the model into a code to form a general predictive capability for the design of gearing [25].
Aboriginal Health in Canada: Historical, Cultural, and Epidemiological Perspectives; Disciplined Hearts: History, Identity, and Depression in an American Indian Community
Authors: Harkin Michael 
Published: March 2005

Aboriginal Health in Canada: Historical, Cultural, and Epidemiological Perspectives. JAMES B. WALDRAM, D. ANN HERRING, and T. KUE YOUNG. Toronto: University of Toronto Press, 1995. xii + 334 pp., figures, tables, index.Disciplined Hearts: History, Identity, and Depression in an American Indian Community. THERESA DELEANE O'NELL. Berkeley and Los Angeles: University of California Press, 1996. xi + 252 pp., figures, maps, index.
The American Revolution in Indian Country: Crisis and Diversity in Native American Communities; Buried Roots and Indestructible Seeds: The Survival of American Indian Life in Story, History, and Spirit
Authors: Dinwoodie David W. 
Published: March 2005

The American Revolution in Indian Country: Crisis and Diversity in Native American Communities. COLIN CALLOWAY. Cambridge: Cambridge University Press, 1995. xxiii + 327 pp., maps, tables, photographs, index.Burled Roots and Indestructible Seeds: The Survival of American Indian Life in Story, History, and Spirit. MARK LINDQUIST and MARTIN ZANGER, eds. Madison: University of Wisconsin Press, 1994, photographs, notes, references.
Lower back disorders among forklift operators: An emerging occupational health problem?
Authors: Waters Thomas , Genaidy Ash , Deddens James , Barriera‐Viruet Heriberto 
Published: March 2005

AbstractBackgroundMost studies focusing on the occupational hazards associated with forklift operation have examined risks of fatalities and traumatic injuries. Few studies have examined the magnitude of risk of musculoskeletal disorders (MSDs). We review and critically appraise the epidemiological studies conducted on forklift operators in relation to MSDs, such as lower back pain and neck problems.MethodsA comprehensive search of databases resulted in the identification of seven epidemiological studies that addressed MSDs. A critical appraisal of these studies was conducted using epidemiological principles and a meta‐analysis approach that involved the use of the confidence limit method to determine an overall “meta‐odds ratio.”ResultsThe methodological quality of these studies ranged from “marginal” to “average” with the exception of one study, which was considered “good.” The meta‐odds ratio for lower back pain among forklift operators was 2.13 (95% CI: 1.57, 2.87).ConclusionsOur results suggest that forklift operators are at increased risk of lower back pain. Additional high quality epidemiological studies are needed in the US, however, to determine the magnitude of risk for MSDs. In this regard, studies should address not only lower back pain among forklifts operators, but also neck pain. A full exposure assessment of physical and non‐physical factors in these studies is needed. Am. J. Ind. Med. 47:333–340, 2005. © 2005 Wiley‐Liss, Inc.
Synthesis of glycidylethylhexylphthalate and its effects on poly(vinyl chloride) films as a novel plasticizer
Authors: Kim Sang‐Woo , Kim Jeong‐Gon , Choi Jung‐Ik , Jeon Il‐Ryun , Seo Kwan‐Ho 
Published: March 2005

AbstractTo improve the processability and prevent the thermal degradation of poly(vinyl chloride) (PVC), various plasticizers and heat stabilizers have to be compounded. Phthalic plasticizers and metal soap stabilizers are usually used with epoxides as costabilizers. Epoxidized soybean oil (ESO), is one of the most commonly used epoxides because of its typical combined roles as a plasticizer and heat stabilizer in PVC compounds. ESO, however, sometimes causes surface contamination of PVC compounds because saturated fatty acids such as stearic and palmitic acids in soybean oil easily bleed onto the surface. In addition, some ingredients in ESO with hydroxide groups and unreacted double bonds during epoxidization also tend to increase the bleeding of ESO. This is due to their low compatibility with PVC resins. In this study, a novel plasticizer of PVC resins, glycidylethylhexylphthalate (GEHP), was synthesized, and its performance was evaluated. GEHP was designed to act as a plasticizer like normal phthalic plasticizers and to act as a heat stabilizer like ESO. Through the addition of epoxy groups in phthalic compounds, the resistance to bleeding was improved, and the plasticizing and heat‐stabilizing effects on the PVC compounds were preserved. Soft PVC films were prepared with GEHP. The mechanical properties, thermal stability, and bleeding properties of the films were investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1347–1356, 2005
Gas sensing in microplates with optodes: Influence of oxygen exchange between sample, air, and plate material
Authors: Arain Sarina , Weiss Svenja , Heinzle Elmar , John Gernot T. , Krause Christian , Klimant Ingo 
Published: March 2005

AbstractMicroplates with integrated optical oxygen sensors are a new tool to study metabolic rates and enzyme activities. Precise measurements are possible only if oxygen exchange between the sample and the environment is known. In this study we quantify gas exchange in plastic microplates. Dissolved oxygen was detected using either an oxygen‐sensitive film fixed at the bottom of each well or a needle‐type sensor. The diffusion of oxygen into wells sealed with different foils, paraffin oil, and paraffin wax, respectively, was quantified. Although foil covers showed the lowest oxygen permeability, they include an inevitable gas phase between sample and sealing and are difficult to manage. The use of oil was found to be critical due to the extensive shaking caused by movement of the plates during measurements in microplate readers. Thus, paraffin wax was the choice material because it avoids convection of the sample and is easy to handle. Furthermore, without shaking, significant gradients in pO2 levels within a single well of a polystyrene microplate covered with paraffin oil were detected with the needle‐type sensor. Higher pO2 levels were obtained near the surface of the sample as well as near the wall of the well. A significant diffusion of oxygen through the plastic plate material was found using plates based on polystyrene. Thus, the location of a sensor element within the well has an effect on the measured pO2 level. Using a sensor film fixed on the bottom of a well or using a dissolved pO2‐sensitive indicator results in pO2 offset and in apparently lower respiration rates or enzyme activities. Oxygen diffusion through a polystyrene microplate was simulated for measurements without convection—that is, for samples without oxygen diffusion through the cover and for unshaken measurements using permeable sealings. This mathematical model allows for calculation of the correct kinetic parameters. © 2005 Wiley Periodicals, Inc.
Cytochalasin D can improve heterologous protein productivity in adherent Chinese hamster ovary cells
Authors: Hayduk Eric J. , Lee Kelvin H. 
Published: March 2005

AbstractWe generated a series of adherent gene‐amplified CHO clones expressing human secreted alkaline phosphatase (SEAP) as a model for heterologous protein production. Clones demonstrate a 26‐ to 52‐fold increase in productivity compared to controls after dhfr/methotrexate‐mediated gene amplification and clone selection. SEAP is stably expressed in these clones over at least a 6‐week period without significant productivity loss. Two‐dimensional protein electrophoresis identified 21 proteins that exhibited altered expression in clones of increasing SEAP productivity. Based on MALDI TOF/TOF mass spectrometry of relevant protein spots, changes in translation, energy pathways, chaperones, regulatory proteins, and cytoskeletal proteins were observed, including a 4‐fold expression increase in actin capping protein. We hypothesized that an alteration of the actin cytoskeleton using cytochalasin D as a mimic for actin‐capping protein could have a beneficial effect on heterologous protein secretion. Treatment with 0.5 μg/mL cytochalasin D increased SEAP productivity 2‐ to 3‐fold compared to an amplified control which resulted in an increase in productivity from 52‐ to 150‐fold compared to a nonamplified parent. © 2005 Wiley Periodicals, Inc.
Rotational Dynamics Account for pH‐Dependent Relaxivities of PAMAM Dendrimeric, Gd‐Based Potential MRI Contrast Agents
Authors: Laus Sabrina , Sour Angélique , Ruloff Robert , Tóth Éva , Merbach André E. 
Published: March 2005

AbstractThe EPTPA5− chelate, which ensures fast water exchange in GdIII complexes, has been coupled to three different generations (5, 7, and 9) of polyamidoamine (PAMAM) dendrimers through benzylthiourea linkages (H5EPTPA=ethylenepropylenetriamine‐N,N,N′,N′′,N′′‐pentaacetic acid). The proton relaxivities measured at pH 7.4 for the dendrimer complexes G5‐(GdEPTPA)111, G7‐(GdEPTPA)253 and G9‐(GdEPTPA)1157 decrease with increasing temperature, indicating that, for the first time for dendrimers, slow water exchange does not limit relaxivity. At a given field and temperature, the relaxivity increases from G5 to G7, and then slightly decreases for G9 (r1=20.5, 28.3 and 27.9 mM−1 s−1, respectively, at 37 °C, 30 MHz). The relaxivities show a strong and reversible pH dependency for all three dendrimer complexes. This originates from the pH‐dependent rotational dynamics of the dendrimer skeleton, which was evidenced by a combined variable‐temperature and multiple‐field 17O NMR and 1H relaxivity study performed at pH 6.0 and 9.9 on G5‐(GdEPTPA)111. The longitudinal 17O and 1H relaxation rates of the dendrimeric complex are strongly pH‐dependent, whereas they are not for the [Gd(EPTPA)(H2O)]2− monomer chelate. The longitudinal 17O and 1H relaxation rates have been analysed by the Lipari–Szabo spectral density functions and correlation times have been calculated for the global motion of the entire macromolecule (τgO) and the local motion of the GdIII chelates on the surface (τlO), correlated by means of an order parameter S2. The dendrimer complex G5‐(GdEPTPA)111 has a considerably higher τgO under acidic than under basic conditions (${\tau {{298\hfill \atop {\rm gO}\hfill}}}$=4040 ps and 2950 ps, respectively), while local motions are less influenced by pH (${\tau {{298\hfill \atop {\rm lO}\hfill}}}$=150 and 125 ps). The order parameter, characterizing the rigidity of the macromolecule, is also higher at pH 6.0 than at pH 9.9 (S2=0.43 vs 0.36, respectively). The pH dependence of the global correlation time can be related to the protonation of the tertiary amine groups in the PAMAM skeleton, which leads to an expanded and more rigid dendrimeric structure at lower pH. The increase of τgO with decreasing pH is responsible for the pH dependent proton relaxivities. The water exchange rate on G5‐(GdEPTPA)111 (${k{{298\hfill \atop {\rm ex}\hfill}}}$=150×106 s−1) shows no significant pH dependency and is similar to the one measured for the monomer [Gd(EPTPA)(H2O)]2−. The proton relaxivity of G5‐(GdEPTPA)111 is mainly limited by the important flexibility of the dendrimer structure, and to a small extent, by a faster than optimal water exchange rate.
High‐Electron‐Density C6H6 Units: Stable Ten‐π‐Electron Benzene Complexes
Authors: Diefenbach Martin , Schwarz Helmut 
Published: March 2005

AbstractThe first stable benzene molecule with ten π electrons is predicted. Stability is achieved through barium atoms acting as an electron‐donating “matrix” to C6H6 in the inverted sandwich complex [Ba2(C6H6)]. The bis(barium)benzene complex has been computed at the density functional level of theory by using the hybrid functional mPW1PW91. Ab initio calculations were performed by using the coupled‐cluster expansion, CCSD(T). Nucleus independent chemical shift (NICS) indices imply distinct aromatic character in the benzene ring of bis(barium)benzene. The D6h‐symmetric structure with a 1A1g electronic ground state represents a thermochemically stable, aromatic benzene molecule with four excess π electrons, stabilised by two barium ions. A possible molecular wire, built up from Ba end‐capped thorium–benzene “sandwiches”, is discussed.
Trend‐setters in environmental policy: the character and role of pioneer countries
Authors: Jänicke Martin 
Published: March 2005

AbstractThere is reason to believe that environmental policy convergence resulting from policy diffusion is influenced not only by functional imperatives of the world market, but also by a collective behaviour of national governments, where pioneer countries function as (intellectual) leaders under conditions of uncertainty. Their solutions for general environmental problems are adopted by other countries. As a rule, there is one single solution that is preferred by a large group or the majority of countries. This regulatory ‘conformism’ makes pioneer roles of countries highly relevant. The article analyses the character and role of such ‘trend‐setters’ in environmental policy. A necessary condition for becoming a pioneer country in environmental policy is a high domestic capacity for environmental policy‐making. This encompasses institutional, economic and informational framework conditions as well as the relative strength of the green advocacy coalition of a country. While these factors refer to relatively stable factors of policy‐making, this does not explain why sometimes countries give up their roles as pioneers. To explain this, an analytical framework is proposed that encompasses situative factors, strategic factors and actor constellations, especially the coalition between organized proponents of environmental objectives and economic modernizers. This coalition of ecological modernizers may break down, for example in times of economic crisis. The political and economic framework conditions of globalization may sometimes bear impediments for pioneers, but at the same time they also provide incentives for highly advanced countries to take over national pioneer roles – at least in the field of environmental protection, which has become an important issue in the competition for innovation. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Synthesis and Conformational Analysis of Saturated3,1,2‐Benzoxazaphosphinine 2‐Oxides
Authors: Kivelä Henri , Zalán Zita , Tähtinen Petri , Sillanpää Reijo , Fülöp Ferenc , Pihlaja Kalevi 
Published: March 2005

AbstractN‐Unsubstituted, N‐methyl and N‐benzyl cis‐ and trans‐2‐(hydroxymethyl)cyclohexylamines were subjected to ring closure with phenylphosphonic dichloride, phenyl dichlorophosphate and bis(2‐chloroethyl)phosphoramidic dichloride in order to synthesize P‐epimeric diastereomers of the corresponding unsubsituted and N‐substituted 2‐phenyl‐, 2‐phenoxy‐ and 2‐[bis(2‐chloroethyl)amino]octahydro‐2H‐3,1,2‐benzoxazaphosphinine 2‐oxides. The stereochemistry and conformations of the prepared compounds were analyzed mainly by variable‐temperature1H, 13C and 31P NMR spectroscopy. Geometry optimizations were performed for some trans‐fused molecules by utilizing the B3LYP DFT method and a locally dense basis set, followed by JH,P coupling constant calculations at the UB3LYP/cc‐pVTZ level of theory. The population of the N‐out conformation of the cis‐fused compounds was found to increase with increasing steric size of the N substituent (H < Me < CH2Ph), and also to be strongly influenced by the configuration at the phosphorus atom. The heteroring of the trans‐fused compounds predominantly adopts a chair conformation with the notable exception of the (2R*,4aS*,8aS*) epimers of the 2‐phenoxy‐substituted compounds, for which the axial tendency of OPh causes the heteroring to adopt mainly B2,4a‐ and/or 1S4a‐type nonchair conformations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Functionalisation of 5‐Substituted Neocuproine Derivatives
Authors: Eggert Jan P. W. , Lüning Ulrich , Näther Christian 
Published: March 2005

Abstract2,9‐Dimethyl‐1,10‐phenanthroline (neocuproine, 1) was functionalised selectively in the 5‐position. Silylation of the methyl groups followed by bromination in the 5‐position was carried out to give the bis(tert‐butyldimethylsilyl)‐substituted neocuproine 3 and 5‐bromo‐2,9‐dimethyl‐1,10‐phenanthroline (4) after deprotection. Compounds 3 and 4 are versatile building blocks for the construction of 5‐substituted neocuproines. Palladium‐catalysed couplings (Suzuki, Sonogashira, Buchwald/Hartwig) can be utilized to connect different substituents to the 1,10‐phenanthroline moiety (5–7). These substituents may carry additional functional groups that allow the further connection of the 5‐substituted neocuproines to form other molecules. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Cobalt‐Catalyzed Vinylation of Functionalized Aryl Halides with Vinyl Acetates
Authors: Amatore Muriel , Gosmini Corinne , Périchon Jacques 
Published: March 2005

AbstractA new method for the preparation of styrene derivatives is described on the basis of the activation of aryl halides by low‐valent cobalt species. A combination of CoII bromide and 2,2′‐bipyridine is suitable as catalyst for the cross‐coupling reaction of a wide range of aromatic halides (X = Cl, Br, I), mostly bearing sensitive moieties, with vinyl acetates. These reactions proceed under mild conditions in the presence of the appropriate reducing agent to afford α‐substituted styrene compounds in satisfactory to high yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Analysis of the glucosinolate pattern of Arabidopsis thaliana seeds by capillary zone electrophoresis coupled to electrospray ionization‐mass spectrometry
Authors: Bringmann Gerhard , Kajahn Inga , Neusüß Christian , Pelzing Matthias , Laug Stefanie , Unger Matthias , Holzgrabe Ulrike 
Published: March 2005

AbstractAn easy and rapid method for the analysis of intact, non‐desulfated glucosinolates by capillary zone electrophoresis (CZE) coupled to electrospray ionization‐time of flight‐mass spectrometry (ESI‐TOF‐MS) is described. Surprisingly, an electrolyte and a sheath liquid based on formic acid provided the best results. In this strongly acidic system, the glucosinolates were separated and detected as anions, resulting in an excellent selectivity. Thus, crude plant extracts could be analyzed without any interference of matrix constituents. The sensitivity together with mass accuracy and true isotopic pattern of the TOF‐MS allowed identification of a broad series of glucosinolates in Arabidopsis thaliana seeds.
Ribozymes against TGFβ1 reverse character of activated hepatic stellate cells in vitro and inhibit liver fibrosis in rats
Authors: Song Yu‐Hu , Chen Xiang‐Long , Kong Xin‐Juan , Liu Nan‐Zhi , Li Wei , Wu Xiao‐Li , Lin Ju‐Sheng , Jin You‐Xin 
Published: March 2005

AbstractBackground/aimsTransforming growth factor β (TGFβ1) is considered the key mediator in the process of liver fibrosis. The purpose of this investigation was to evaluate the activity of ribozymes against TGFβ1 in a cell‐free system and activated hepatic stellate cells (HSCs), and antifibrotic effect in activated HSCs in vitro and in rats.MethodsThree ribozymes targeting against TGFβ1 mRNA were designed, and then cloned into the U1 snRNA expression cassette. The chimeric ribozymes were selected for the analysis of their performances in activated HSCs through the detection of their cleavage activities in a cell‐free system. After ribozyme‐encoding plasmids had been transfected into HSC‐T6 cells, the effects of ribozymes on activated HSCs were evaluated through the analysis of proliferation, activation and collagen deposition of HSC‐T6. The adenoviral vector expressing the ribozymes was constructed, and then delivered into rat models of hepatic fibrosis induced by carbon tetrachloride.ResultsTGFβ1 expression was efficiently down‐regulated in activated HSCs by U1 snRNA chimeric ribozymes which possessed perfect cleavage activity in a cell‐free system. Further studies demonstrated that U1 snRNA chimeric ribozymes inhibited the synthesis of collagen I, reduced deposition of collagen I, suppressed BrdU incorporation, but had no effect on desmin and α‐SMA expression in transfected HSC‐T6 cells. Histological analysis demonstrated that the adenoviral vector expressing ribozyme (Rz803) could alleviate fibrotic pathology in rats treated with carbon tetrachloride.ConclusionsThe anti‐TGFβ1 ribozymes could reverse the character of activated HSCs in vitro and improve fibrotic pathology in vivo. It indicated that TGFβ1 could be considered as a novel candidate for a therapeutic agent against hepatic fibrosis. Copyright © 2005 John Wiley & Sons, Ltd.