bluuebunny/crossref_metadata_2025 huggingface dataset:
Standing laparoscopic repair of a ruptured urinary bladder in a mature draught horse
Authors: Tuohy J. L. , Hendrickson D. A. , Hendrix S. M. , Bohanon T. C.
Published: April 2009

Rupture of the urinary bladder, although relatively common in foals, is an infrequent occurrence in adult stallions. Standing laparoscopic repair of a ruptured urinary bladder offers significant advantages over other treatment options, and to date, there are no reports describing this technique in treating adult stallions. This case study details the treatment of a mature draught horse for uroperitoneum secondary to a ruptured urinary bladder. Standing laparoscopic repair of the ruptured bladder was performed. No major post operative complications developed, and the horse has not had any recurrence of problems with the urinary bladder. Successful standing laparoscopic repair in this horse demonstrated the method's viability, which offers superior intraoperative visualisation and access to the bladder, while eliminating the risks of general anaesthesia.
Posterior lens luxation with associated glaucoma in a pony
Authors: McCluskie L. K. , Woodford N. S. , Carter W. J.
Published: April 2009

Secondary lens luxation is an infrequent consequence of equine recurrent uveitis (ERU). This Case Report describes a pony with posterior lens luxation with associated glaucoma, thought to be secondary to ERU.
The Anti-American as Americanizer: Revisiting the Anti-American Century in Germany
Authors: Gassert Philip
Published: April 2009

This article contextualizes the recent debates about German and European anti-Americanism by highlighting the paradoxical nature of such sentiments. Using examples from the Weimar Republic, Nazi Germany, and the postwar period, this article shows that anti-Americanism arose less from divergent cultural trends and perceived "value gaps," as many recent authors have argued. Rather, anti-Americanism should be seen as a measure of America's continued influence and success. After all, anti-Americanism more often than not went hand in glove with "Americanization." Frequently, anti-Americans, namely those who are voicing anti-Americanism, were products of cultural transfer-processes emanating in the U.S. They also saw themselves allied with American anti-establishment forces. Thus, to a degree, anti-Americanism can be seen as by-product of westernization. Although the focus of this article is on Germany, the argument about the complex web of repudiation and embrace can be observed in other European (or even African, Arab, Asian, or South American) contexts as well.
Turning "liberal Critics" into "Liberal-Conservatives": Kurt Sontheimer and the Re-coding of the Political Culture in the Wake of the Student Revolt of "1968"
Authors: Bavaj Riccardo
Published: April 2009

The student revolt of the late 1960s had far-reaching repercussions in large parts of West German academia. This article sheds light on the group of liberal scholars who enjoyed a relative cohesiveness prior to "1968" and split up in the wake of the student revolt. The case of Kurt Sontheimer (1928-2005) offers an instructive example of the multifaceted process of a "liberal critic" turning into a liberal-conservative. While he initially welcomed the politicization of students and the democratization of universities, he became increasingly concerned about the stability of West Germany's political order and placed more and more emphasis on preserving, rather than changing the status quo. Sontheimer was a prime example of a liberal critic shifting and being shifted to the center-Right within a political culture that became increasingly polarized during the 1970s.
Current Trends in German Foreign Policy Analysis: A Farewell to Old Ideals?
Authors: Crueger Hans-Christian
Published: April 2009

Siegmar Schmidt, Gunther Hellmann and Reinhard Wolf, eds., Handbuch zur deutschen Außenpolitik (Wiesbaden: VS Verlag, 2007)

Thomas Jäger, Alexander Höse and Kai Oppermann, eds., Deutsche Außenpolitik. Sicherheit, Wohlfahrt, Institutionen und Normen (Wiesbaden: VS Verlag, 2007)

Gunther Hellmann, Deutsche Außenpolitik. Eine Einführung (Wiesbaden: VS Verlag, 2006)

Wilfried von Bredow, Die Außenpolitik der Bundesrepublik Deutschland. Eine Einführung (Wiesbaden: VS Verlag, 2006)
Generalised Entropy of Curves for the Analysis and Classification of Dynamical Systems
Authors: Balestrino Aldo , Caiti Andrea , Crisostomi Emanuele
Published: April 2009

This paper provides a new approach for the analysis and eventually the classification of dynamical systems. The objective is pursued by extending the concept of the entropy of plane curves, first introduced within the theory of the thermodynamics of plane curves, to Rn space. Such a generalised entropy of a curve is used to evaluate curves that are obtained by connecting several points in the phase space. As the points change their coordinates according to the equations of a dynamical system, the entropy of the curve connecting them is used to infer the behaviour of the underlying dynamics. According to the proposed method all linear dynamical systems evolve at constant zero entropy, while higher asymptotic values characterise nonlinear systems. The approach proves to be particularly efficient when applied to chaotic systems, in which case it has common features with other classic approaches. Performances of the proposed method are tested over several benchmark problems.
The Potential Impact on Farmer Health of Enhanced Export Horticultural Trade between the U.K. and Uganda
Authors: Cross Paul , Edwards Rhiannon T , Nyeko Philip , Edwards-Jones Gareth
Published: April 2009

The export of vegetables from African countries to European markets presents consumers with an ethical dilemma: should they support local, but relatively well-off farmers, or poorer farmers from distant countries? This paper considers the issue of farm worker health in the U.K. and Uganda, and considers the dilemma facing U.K. consumers if Uganda achieves their aim of exporting more vegetables to the U.K. Self-reported health scores of 1,200 farm workers in the U.K. and Uganda were measured with the internationally recognised SF-36 questionnaire and compared to an international population norm. The age-corrected health status of U.K. farm workers was significantly lower than the population norm, whereas Ugandans scored significantly higher (indicating good health) for physical health and lower for mental health. If Ugandan produce enters U.K. markets, then consumers may wish to consider both the potential benefits that enhanced trade could offer Ugandan farmers compared with its impacts on U.K. workers.
Comparison of Low Cost Miniature Spectrometers for Volcanic SO2 Emission Measurements
Authors: Kantzas Euripides P. , McGonigle Andrew J. S. , Bryant Robert G.
Published: April 2009

Miniature ultraviolet USB coupled spectrometers have become ubiquitously applied over the last decade for making volcanic SO2 emission rate measurements. The dominantly applied unit has recently been discontinued however, raising the question of which currently available devices should now be implemented. In this paper, we consider, and make recommendations on this matter, by studying a number of inexpensive compact spectrometers in respect of measurement performance and thermal behaviour. Of the studied units, the Avaspec demonstrated the best prospects for the highest time resolution applications, but in the majority of cases, we anticipate users likely preferring the less bulky USB2000+s.
Constructing a Regional Tourism Satellite Account: The Case of Queensland
Authors: Pham Tien Duc , Dwyer Larry , Spurr Ray
Published: April 2009

This article presents the results of a scoping study to examine the feasibility of constructing Tourism Satellite Accounts (TSAs) for the regions of Queensland, Australia's primary holiday state. The construction of a regional TSA should not be considered as the end of a process but
rather as the beginning of an ongoing process to unfold the importance of the tourism sector at a level relevant to policy makers. Regional TSAs may be expected to generate policy-relevant insights so that tourism activity can be adequately nurtured and stimulated at the right time and right
place for sustainable regional economic development. This report presents findings regarding the most suitable methodology for the task, given the available data. The construction of a TSA at the regional level is a complex and potentially expensive task, and the aim of this study has been
to propose a methodology that will have long-term application and that can be maintained and updated in an efficient and cost-effective manner. Although set in the context of regional Queensland, the discussion is of general interest for regional tourism stakeholders in destinations worldwide.
The Physical Carrying Capacity at the Cultural Heritage Site of Petra
Authors: Magablih Khalid , Al-Shorman Abdulla
Published: April 2009

This study aims at estimating the physical carrying capacity at Petra and offering alternatives to the current situation, which negatively affects the physical and ecological environments of the site. The study utilized data from the Ministry of Tourism, the Central Bank of Jordan,
and Jordan Tourism Board for the years 1999 to 2005. The carrying capacity was estimated based on specific formulas after Boullon. The results show that the calculated carrying capacity (16,200 visitors per month) exceeds the acceptable limits except in January. It is also visible that the
number of monthly visitors is about the calculated carrying capacity during the season of Arab tourism in Jordan, which is the largest market segment. The study recommends controlling the seasonality of tourism in Petra, using the Siq as an entry point with a single direction flow for tourists,
and adopting a promotional policy that ensures the balanced distribution of tourists around the year.
Small Island Developing States (SIDS): Tourism and Economic Development
Authors: Singh Diaram Ramjee
Published: April 2009

For several decades many small island developing states (SIDS) have come to rely on tourism as the primary agent of economic development. Although in many instances the industry has emerged as one of the largest and fastest growing economic sectors, much of the anticipated developmental
benefits that tourism was expected to deliver have failed to materialize. This has influenced several tourism researchers to question the presumed link between tourism and economic development. This article seeks to explore whether such a link exists and if so what is the extent of the industry's
contribution among SIDS. To answer these questions the study will rely on evidence obtained from a simple cross-sectional regression model as well as on estimates of the tourism income multipliers that were generated for several of these island states.
Tourism Information Trust as a Bridge Between Information Value and Satisfaction: An Exploratory Study
Authors: Tang Liang , Jang Soocheong (Shawn)
Published: April 2009

Online travel information embraces a variety of sources that represent different views and orientations. How do potential travelers decide whether or not to believe the information and, further, use it for their trips? This research proposes a theoretical model of potential tourists' level of trust regarding online tourism information, empirically investigates factors that produce trust (utilitarian value and hedonic value), and identifies beneficial consequences of trust (satisfaction). Structural Equation Modeling was employed to fulfill these research aims. The findings confirm that both the utilitarian and hedonic value attributes of travel information significantly contribute to the generation of trust. Travelers' trust was found to depend upon their satisfaction with online information. This study suggests that tourism information providers should not only limit their views to communicating marketing information and positioning strategies via the websites, but also need to think more about what information “buyers” need and want.
Management and Policy Implications of Coastal Tourism Forecasts
Authors: Dixon Anthony W. , Oh Chi-Ok , Draper Jason
Published: April 2009

One of the fastest growing segments of the world's tourism industry is coastal tourism. As interest in coastal tourism intensifies, the increasing demand on coastal resources will require local governments and private businesses to obtain information on future tourism demand. However,
management agencies often fail to incorporate forecasting results into the strategic planning process. The purpose of this article is to present comprehensive forecasting information of coastal tourism demand using various tourism-related time series variables, and provide public and private
agencies with a framework for integrating coastal demand forecasts into the strategic planning process. Two different quantitative forecasting techniques were used to project future coastal tourism demand in South Carolina: Auto Regressive Integrated Moving Average (ARIMA) methods for short-term
and midterm forecasts and Naive 1 method for long-term forecasts. Short-term forecast results suggest accommodation taxes in coastal counties will steadily increase over the next several years, while midterm forecasts of coastal tourism-related employment indicates a significant increase in
labor force requirements. Long-term forecasts imply visitation to and demand of beaches and coastal resources will continue to intensify. In the coming years, tourism-related businesses in coastal destinations will be challenged to provide satisfactory experiences due to a small labor pool
of quality workers. Failure to incorporate forecasts in the strategic planning process may result in the degradation of tourism resources, resulting in a reduction of tourist visitation. Integrating accurate forecasts into the strategic planning process are essential to improving the likelihood
of sustainable development at tourism destinations.
Skiers' Sense of Snow: Tourist Skills and Winter Holiday Attribute Preferences
Authors: Steen Jacobsen Jens KR. , Denstadli Jon Martin , Rideng Arne
Published: April 2009

Winter sports holidaymaking is an essential part of tourism, but skiers and their preferences and perceptions have not been much researched in academic contexts. This article presents certain factors influencing alpine skiers' destination choices and incorporates an examination of how
these holidaymakers regard various attributes in relation to their destination choice. The study encompasses three types of destination aspects: ski attributes, price attributes, and destination/facility attributes. Alpine ski holidaymaking is here regarded as a skilled activity, and the skiers'
destination choices and the related information sources are analyzed in relation to their winter holiday expertise, operationalized here as skiing skill level.
Are Local Residents Fickle Minded? Influence of Moral Beliefs on Perceived Gambling Impacts
Authors: Chhabra Deepak
Published: April 2009

This study examines the influence of moral beliefs on casino-style gambling impact perceptions. The subjects under investigation are the local population of the State of Iowa (USA). Results suggest that there is a significant relationship between moral values and the local resident
attitudes toward gambling. Moral values predict quite a bit of variance in perceptions and they serve as a catalyst for negative perceptions. Overall, the results indicate that the Iowans are not fickle minded but they are a heterogeneous group of residents and their perceptions reflect their
values.
Residents' View of Expected Tourism Impact, Attitude, and Behavioral Intention
Authors: Yen I-Yin , Kerstetter Deborah
Published: April 2009

We examined the relationships between expected tourism impacts, attitudes toward local tourism development, and behavioral intention to support local tourism development using data collected from residents of Penghu, Taiwan. The results indicated that expected tourism impacts are perceived
to be multidimensional, attitudes differ towards current and future tourism development, and support for and objection to tourism development are separate constructs. Further, the effects of beliefs (i.e., tourism impacts) on attitudes and intentions are not as straightforward as previous
research has suggested. Study limitations, implications, and recommendation for future research are discussed.
The Assessment Model for Cultural Festival Budgets
Authors: Byun Woo-Hee , Lee Timothy Jeonglyeol , Han Sang-Hyun
Published: April 2009

The purpose of this study is to develop local cultural festivals by providing an effective model for objectively evaluating the tourism events, so that public agencies can allocate the budget in the light of accurate information. It establishes model from analyzing the five cultural
festivals in Korea by measuring the evaluation variables and using them as coefficients. This study also provides local governments with objective data to make better decisions when allocating the annual budgets of the cultural festivals. To achieve this, three types of value variables were
investigated from industry professionals, Korean/foreign visitors, and local residents. The authors examined the model from the viewpoint of the public officials in charge of budgeting for the festivals. The contribution of this study is that it can be applied to the postevaluation of public
tourism projects, and it can also be useful for applying the results to managerial decision making for the future planning of cultural tourism events.
Synthesis of unsymmetrically substituted biaryls via sequential lithiation of dibromobiaryls using integrated microflow systems
Authors: Nagaki Aiichiro , Takabayashi Naofumi , Tomida Yutaka , Yoshida Jun-ichi
Published: April 2009

A microflow system consisting of micromixers and microtube reactors provides an effective method for the introduction of two electrophiles onto dibromobiaryls. Selective monolithiation of dibromobiaryls, such as 2,2′-dibromobiphenyl, 4,4′-dibromobiphenyl, 2,7-dibromo-9,9-dioctylfluorene, 2,2′-dibromo-1,1′-binaphthyl, and 2,2′-dibromobibenzyl with 1 equiv ofn-butyllithium followed by the reaction with electrophiles was achieved using a microflow system by virtue of fast micromixing and precise temperature control. Sequential introduction of two different electrophiles was achieved using an integrated microflow system composed of four micromixers and four microtube reactors to obtain unsymmetrically substituted biaryl compounds.
Oxidative cyclization of alkenols with Oxone using a miniflow reactor
Authors: Yamada Yoichi M A , Torii Kaoru , Uozumi Yasuhiro
Published: April 2009

A miniflow system for oxidative cyclization of alkenols with Oxone was developed. Thus, the oxidative cyclization of (Z)- and (E)-alkenols in i-PrOH with an aqueous solution of Oxone proceeded smoothly and safely in a PTFE tube without any exogenous catalytic species, and was subsequently quenched in a flow-reaction manner to afford the corresponding furanyl and pyranyl carbinols quantitatively within 5 or 10 min of residence time.
Asymmetric reactions in continuous flow
Authors: Mak Xiao Yin , Laurino Paola , Seeberger Peter H
Published: April 2009

An overview of asymmetric synthesis in continuous flow and microreactors is presented in this review. Applications of homogeneous and heterogeneous asymmetric catalysis as well as biocatalysis in flow are discussed.
Inversión de efectos de sitio y factor Q utilizando cocientes espectrales
Authors: Moya Fernández A.
Published: April 2009

En este estudio se llevó a cabo la inversión de los efectos de sitio y del valor de la atenuación Q, utilizando la técnica de cocientes espectrales. La zona de estudio corresponde a la parte central de Costa Rica y los datos utilizados provienen de la red de movimiento fuerte que el Laboratorio de Ingeniería Sísmica (INII-UCR) tiene instalada en el país. La técnica empleada utiliza un evento como referencia en lugar de una estación sísmica, por esa razón, los efectos de sitio que se obtienen son los valores absolutos de amplificación. Los resultados muestran que varias de las estaciones ubicadas en sitios sobre suelo blando tienen mayores factores de amplificación que las que se encuentran sobre terrenos relativamente mejor consolidados. También, el valor de la atenuación en la forma de factor Q se encontró que era dependiente de la frecuencia con un valor aproximado de Q(f) = (131,6 ± 0,1)f (1,1 ± 0,2).
Overview of the Physical State of Proteins Within Cells
Authors: Petty Howard R.
Published: April 2009

Proteins, the end product of gene expression, play a pivotal role in cellular structure and function. To understand how proteins work it is necessary to understand their physical state within the cell. This unit reviews the classification of proteins, how that is related to the hydropathicity of the protein, other factors that affect the heterogeneity of proteins, protein assemblies, methods for altering the solubility of proteins, and limitations of in vitro manipulations of proteins.
Stereoselective Synthesis of Metalated Cyclobutyl Derivatives
Authors: Tsoglin Einav , Chechik Helena , Karseboom Guy , Chinkov Nicka , Stanger Amnon , Marek Ilan
Published: April 2009

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Treatment of Z‐vinyl carbamates with dicyclopentadienyl(diethyl)zirconium [Et2ZrCp2] leads to cyclobutyl‐zirconocene derivatives in good yields and as a unique diastereoisomer. The reaction proceeds through a carbometalative ring‐expansion followed by an intramolecular migratory insertion.
Supply chain risk identification using a HAZOP‐based approach
Authors: Adhitya Arief , Srinivasan Rajagopalan , Karimi Iftekhar A.
Published: April 2009

Risk management has become imperative for today's complex supply chains. Most approaches reported in the literature have been ad‐hoc and specific to certain risks; a general and comprehensive approach is lacking. To address this, we present a structured methodology for risk identification. Supply chain networks are in many ways similar to chemical plants, therefore well‐established methods and concepts from chemical process risk management can be adapted to supply chains. Drawing from this analogy, we propose to represent supply chain structure and operations using flow and work‐flow diagrams, equivalent to process flow diagrams (PFDs) and operating procedures. Following the HAZard and OPerability (HAZOP) analysis method common in process safety, risk identification can be performed by systematically generating deviations in different supply chain parameters and identifying their possible causes, consequences, safeguards, and mitigating actions. The application and benefits of the proposed approach are demonstrated using a refinery supply chain case study. © 2009 American Institute of Chemical Engineers AIChE J, 2009
The grandmaternal niche: Critical caretaking among Martu Aborigines
Authors: Scelza Brooke A.
Published: April 2009

This paper expands upon the existing literature on the evolutionary importance of grandmothers by examining how direct care by grandmothers differs from care provided by other helpers within a population of Martu Aborigines. Behavioral observations were collected on ten babies who ranged from 3 months to 3 years of age. The results show that Martu grandmothers were in contact with their grandchildren more than any person other than the mother, and they were also more likely than any other category of caregiver to perform high‐demand tasks, such as bathing or feeding. These results suggest that Martu grandmothers are specializing in the type of care they provide and posits that high‐quality allocare is an important pathway to increased health and survival of grandchildren. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Platinum(II)‐Catalyzed Intramolecular Cyclization of o‐Substituted Aryl Alkynes through sp3 CH Activation
Authors: Yang Shangdong , Li Zigang , Jian Xing , He Chuan
Published: April 2009

In‐den Ring: PtCl2 katalysiert die Cyclisierung von o‐Isopropyl‐ und o‐Benzylarylalkinen zu Indenderivaten, die in guten Ausbeuten und mit hohen Selektivitäten entstehen. Der Reaktionsmechanismus scheint eine sp3‐C‐H‐Aktivierung und eine 1,4‐Wasserstoffwanderung einzuschließen (siehe Schema).

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Highly Selective Catalytic Conversion of Phenolic Bio‐Oil to Alkanes
Authors: Zhao Chen , Kou Yuan , Lemonidou Angeliki A. , Li Xuebing , Lercher Johannes A.
Published: April 2009

Öl und Wasser: Eine neue energieeffiziente und atomökonomische katalytische Produktion von Alkanen und Methanol durch Veredelung der phenolischen Fraktion von Bioöl wird vorgestellt. Der in wässriger Phase durchgeführte Eintopf‐Hydrodesoxygenierungsprozess nutzt zwei Katalysatoren, was die Teilreaktionen Hydrierung, Hydrolyse und Dehydratisierung erleichtert.

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Structural Tracking of a Bimolecular Reaction in Solution by Time‐Resolved X‐Ray Scattering
Authors: Haldrup Kristoffer , Christensen Morten , Cammarata Marco , Kong Qingyu , Wulff Michael , Mariager Simon O. , Bechgaard Klaus , Feidenhans'l Robert , Harrit Niels , Nielsen Martin M.
Published: April 2009

Molekülfilm: Zeitauflösende Röntgenbeugungsstudien lieferten direkte Informationen über die Struktur eines elektronisch angeregten Komplexes während seiner Bildung in der bimolekularen Reaktion zwischen angeregten Octawasserstoff[tetrakis‐μ‐diphosphito‐1κP:2κP′‐diplatinat](4‐)‐Ionen (PtPOP*) und Thalliumionen. Im Exciplex sind ein Thallium(I)‐ und zwei Platin(II)‐Ionen kollinear.

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Innentitelbild: Challenging the Metallocene Dominance in Actinide Chemistry with a Soft PNP Pincer Ligand: New Uranium Structures and Reactivity Patterns (Angew. Chem. 20/2009)
Authors: Cantat Thibault , Graves Christopher R. , Scott Brian L. , Kiplinger Jaqueline L.
Published: April 2009

Ein stehender Eisberg versinnbildlicht, wie der weiche PNP‐Pinzettenligand, den J. L. Kiplinger et al. in der Zuschrift auf S. 3735 ff. beschreiben, die Vorherrschaft der Metallocene (als Schiff) in der Actinoidenchemie herausfordert. Der Ersatz von C5Me5 durch den PNP‐Liganden ist eine exzellente Strategie, um neue Reaktionsweisen und neue Actinoidstrukturen zu erzeugen. Die besonderen elektronischen und sterischen Eigenschaften des PNP‐Liganden schaffen Zugang zu Strukturen, die mit dem C5Me5‐Ligandensatz nicht erhältlich sind und die für Urankomplexe bisher nie beschrieben wurden. (Wir danken Anthony Mancinco für die Graphikgestaltung.)

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Solution‐Based Evolution and Enhanced Methanol Oxidation Activity of Monodisperse Platinum–Copper Nanocubes
Authors: Xu Dan , Liu Zhaoping , Yang Hongzhou , Liu Qingsheng , Zhang Jun , Fang Jiye , Zou Shouzhong , Sun Kai
Published: April 2009

Shape‐controlled catalysis: High‐quality Pt–Cu nanocubes with an average size of about 8 nm (see picture, scale bar=20 nm) were synthesized from a high‐temperature organic solution system in the presence of various capping ligands. These cubic Pt–Cu nanocrystals terminated with {100} facets demonstrated a superior catalytic activity towards methanol oxidation compared to similar sized Pt–Cu and Pt nanospheres.

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Toroidal Micelles of Uniform Size from Diblock Copolymers
Authors: Huang Haiying , Chung Bonghoon , Jung Jueun , Park Hae‐Woong , Chang Taihyun
Published: April 2009

Uniform nanodonuts: Stable toroidal micelles that have a highly uniform size and shape spontaneously self‐assemble from a selective THF/ethanol solvent mixture (see 3D AFM image). The donut‐shaped micelles can be used as a template to grow gold nanoparticles, which form along the ring surface.

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Synthesis of β,γ‐Unsaturated Acids from Allenes and Carbon Dioxide
Authors: North Michael
Published: April 2009

Hidden talent: Often perceived to be too thermodynamically and kinetically inert to be a useful chemical feedstock, carbon dioxide adds to allenes under exceptionally mild reductive conditions in the presence of a palladium pincer complex to give β,γ‐unsaturated carboxylic acids (see scheme). This transformation is discussed in the context of the requirements for CO2 fixation. DMF=N,N‐dimethylformamide, Tf=trifluoromethanesulfonyl.

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Modern Supramolecular Gold Chemistry.Gold‐Metal Interactions and Applications. Edited by A. Laguna.
Authors: Puddephatt Richard J.
Published: April 2009

Wiley‐VCH, Weinheim 2008. 505 pp., hardcover € 159.00.—ISBN 978‐352732095

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A Hydride‐Rich Magnesium Cluster
Authors: Arrowsmith Merle , Hill Michael S. , MacDougall Dugald J. , Mahon Mary F.
Published: April 2009

High‐de‐hydride! A straightforward reaction between a magnesium silylamido/N‐heterocyclic carbene adduct and phenylsilane provides a {Mg4H6} cluster molecule that may be regarded as a combination of two magnesium dihydride and two magnesium monohydride moieties.

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Cover Picture: Nanoscale Chemical Imaging of the Reduction Behavior of a Single Catalyst Particle (Angew. Chem. Int. Ed. 20/2009)
Authors: de Smit Emiel , Swart Ingmar , Creemer J. Fredrik , Karunakaran Chithra , Bertwistle Drew , Zandbergen Henny W. , de Groot Frank M. F. , Weckhuysen Bert M.
Published: April 2009

Iron‐based catalysts for the Fischer–Tropsch synthesis bring about the conversion of synthesis gas (CO/H2) derived from coal or biomass into liquid transportation fuels. In their Communication on page 3632 ff., B. M. Weckhuysen, F. M. F. de Groot, and co‐workers provide insights into the difference in behavior of the catalyst precursors during pretreatment in H2 on both the nanoscopic and the bulk scale. These findings enable further understanding of how the activated catalyst works.

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Broadband dielectric spectroscopy on the molecular dynamics in different generations of hyperbranched polyester
Authors: Turky Gamal , Shaaban Shereen S. , Schöenhals Andreas
Published: April 2009

Dielectric spectroscopy (10−2 Hz to 106 Hz) was employed to investigate the molecular dynamics of hyperbranched polyesters where the number of the generation is systematically varied from 2 to 5. As a first result, the dielectric properties depends strongly on the generation of the hyperbranched polymers. For higher generations (3 to 5) at temperatures below Tg two relaxation processes are observed, a γ‐process at lower temperatures and a β‐process at higher ones. The apparent activation energies are around 100 kJ/mol which seems to be too high for truly localized processes. For the Generation 2, only the γ‐process is observed. For all investigated polymers the dielectric α‐relaxation could not be observed because of strong conductivity effects. Therefore, the conductivity is systematically analyzed which obeys the peculiarities found to be characteristic for semiconducting disordered materials. Especially, the Barton/Nakajima/Namikawa relationship is found to be valid. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Selective particle distribution and mechanical properties of nano‐CaCO3/ethylene‐propylene‐diene terpolymer/polypropylene composites with high content of nano‐CaCO3
Authors: Wang Xu , Xu Ke‐Jie , Xu Xiang‐Bin , Park Soo‐Jin , Kim Seok
Published: April 2009

Ternary composite of nano‐CaCO3/ethylene‐propylene‐diene terpolymer (EPDM)/polypropylene (PP) with high content of nano‐CaCO3 was prepared by two step compounding route, in which EPDM and nano‐CaCO3 were mixed first, and then melt compounding with PP matrix. The influence of mixing time during the second compounding on distribution of nano‐CaCO3 particles and the impact strength of the ternary composite have been investigated. It was found that the Izod impact strength of composite decreased with increasing mixing time. The observation of transmission electron microscopy obviously showed that nano‐CaCO3 particles transported from EPDM to PP matrix firstly and then from PP to the vicinity of EPDM dispersed phase with the increase of mixing time. This phenomenon can be well explained by the minimization of the dissipative energy and the Young's equation. The scanning electron microscope images show that lots of nano fibrils exist at the interface between nano‐CaCO3 agglomerates and matrix, which can dissipate lots of energy. The toughening mechanism has been interpreted in terms of three‐stage‐mechanism: stress concentration, void and shear band formation, and induced shear yielding. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Investigation of the postcure reaction and surface energy of epoxy resins using time‐of‐flight secondary ion mass spectrometry and contact‐angle measurements
Authors: Awaja Firas , Gilbert Michael , Fox Bronwyn , Kelly Georgina , Pigram Paul J.
Published: April 2009

Time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) was used to investigate correlations between the molecular changes and postcuring reaction on the surface of a diglycidyl ether of bisphenol A and diglycidyl ether of bisphenol F based epoxy resin cured with two different amine‐based hardeners. The aim of this work was to present a proof of concept that ToF‐SIMS has the ability to provide information regarding the reaction steps, path, and mechanism for organic reactions in general and for epoxy resin curing and postcuring reactions in particular. Contact‐angle measurements were taken for the cured and postcured epoxy resins to correlate changes in the surface energy with the molecular structure of the surface. Principal components analysis (PCA) of the ToF‐SIMS positive spectra explained the variance in the molecular information, which was related to the resin curing and postcuring reactions with different hardeners and to the surface energy values. The first principal component captured information related to the chemical phenomena of the curing reaction path, branching, and network density based on changes in the relative ion density of the aliphatic hydrocarbon and the C7H7O+ positive ions. The second principal component captured information related to the difference in the surface energy, which was correlated to the difference in the relative intensity of the CxHyNz+ ions of the samples. PCA of the negative spectra provided insight into the extent of consumption of the hardener molecules in the curing and postcuring reactions of both systems based on the relative ion intensity of the nitrogen‐containing negative ions and showed molecular correlations with the sample surface energy. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Influence of the molecular weight of chitosan on the spinnability of chitosan/poly(vinyl alcohol) blend nanofibers
Authors: Homayoni Homa , Ravandi Seyed Abdolkarim Hosseini , Valizadeh Masoumeh
Published: April 2009

The electrospinning of the biopolymer chitosan (CS) and poly(vinyl alcohol) (PVA) was investigated with 90% acetic acid as the solvent and with different CS/PVA ratios. The long chains of high‐molecular‐weight CS prevented it from forming nanofibers in a high‐voltage field. The treatment of CS under high‐temperature alkali conditions reduced its molecular weight exponentially with the treatment time and caused a reduction of the viscosity consequently. PVA, acting as a plasticizer and accompanied by the alkali‐treated CS of lower viscosity, made the electrospinning of CS/PVA blends possible. The effects of the duration of the alkali treatment on the molecular weight of CS and its viscosity were investigated and optimized. The diameter of the bicomponent nanofiber decreased proportionally with the increase in the CS portion, whereas the surface porosity increased inversely. Fourier transform infrared studies illustrated that the alkali treatment or blending of CS with PVA had no effect on its chemical nature. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Potentiometric studies on the interaction between superoxide dismutase and hyaluronic acid
Authors: Fan Yaofeng , Wang Yinong , Fan Yunge , Ma Jianbiao
Published: April 2009

The formation process of soluble complexes and insoluble aggregates between superoxide dismutase (SOD) and hyaluronic acid (HA) was studied using quasielastic light scattering and turbidimetric titration. The electrostatic binding between them was investigated in detail through potentiometric titration and turbidimetric titration carried out from high to low pH. Turbidimetric titration was used to determine the specific pH values at which soluble complex formation was initiated (pHc) and phase separation occurred (pHϕ). An increase of the ionic strength causes a decrease of pHc and pHϕ. With the increase of HA concentrations, pHϕ increases but pHc does not vary. The formed “salt bridges” between
$-{\rm NH_3^+}$
(SOD) and COO− (HA) result in the formation of stable SOD‐HA complexes and even aggregates. The necessary condition of electrostatic binding was also given for protein‐acidic polyelectrolyte systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Using isoconversional kinetic analysis of liquid melamine–formaldehyde resin curing to predict laminate surface properties
Authors: Kandelbauer A. , Wuzella G. , Mahendran A. , Taudes I. , Widsten P.
Published: April 2009

The curing kinetics of a liquid melamine–formaldehyde impregnation resin were analyzed with differential scanning calorimetry, and the conversion‐dependent activation energy for melamine–formaldehyde curing was estimated with the isoconversional model‐free kinetic approach developed by Vyazovkin. The conversion‐dependent activation energy was used to extend the predictive power of a response surface model describing the influence of some processing factors (press time and resin composition) in the manufacturing of particleboards coated with melamine–formaldehyde‐impregnated papers. By substituting the factor “press time” in an RSM established for a press temperature of 170 °C by the factor “conversion” which is accessible from thermo‐chemical analysis, additional information on temperature was incorporated into the model. Model applicability for additional temperatures was evaluated with 12 validation experiments. Although chemical resistance was difficult to model, cleanability was sufficiently well described by only one factor (conversion). Surface gloss depended on both the conversion and catalyst amount and was predicted by a two‐factor interaction model (R2 = 0.95). This study demonstrates that parameters derived from the isoconversional kinetic analysis of liquid resins not only are theoretical descriptors but also have direct practical relevance in the modeling of product properties derived from these liquid resins when used to supplement technological databases. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Poly(vinylbenzylchloride) beads grafted with polymer brushes carrying hydrazine ligand for reversible enzyme immobilization
Authors: Yavuz Erdem , Bayramoğlu Gülay , Şenkal B. Filiz , Arıca M. Yakup
Published: April 2009

Poly(glycidylmethacrylate), p(GMA), brush grafted poly(vinylbenzyl chloride/ethyleneglycol dimethacrylate), p(VBC/EGDMA), beads were prepared by suspension polymerization and the beads were grafted with poly(glycidyl methacrylate), p(GMA), via surface‐initiated atom transfer radical polymerization aiming to construct a material surface with fibrous polymer. The epoxy groups of the fibrous polymer were reacted with hydrazine (HDZ) to create affinity binding site on the support for adsorption of protein. The influence of pH, and initial invertase concentration on the immobilization capacity of the p(VBC/EGDMA‐g‐GMA)‐HDZ beads has been investigated. Maximum invertase immobilization onto hydrazine functionalized beads was found to be 86.7 mg/g at pH 4.0. The experimental equilibrium data obtained invertase adsorption onto p(VBC/EGDMA‐g‐GMA)‐HDZ affinity beads fitted well to the Langmuir isotherm model. It was shown that the relative activity of immobilized invertase was higher than that of the free enzyme over broader pH and temperature ranges. The Km and Vmax values of the immobilized invertase were larger than those of the free enzyme. After inactivation of enzyme, p(VBC/EGDMA‐g‐GMA)‐HDZ beads can be easily regenerated and reloaded with the enzyme for repeated use. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Adsorption of a gold‐iodide complex (AuI2−) onto cellulose acetate‐polyaniline membranes: Equilibrium experiments
Authors: Rodríguez F. , Castillo‐Ortega M. M. , Encinas J. C. , Sánchez‐Corrales V. M. , Pérez‐Tello M. , Munive G. T.
Published: April 2009

The adsorption of AuI complex onto acetate cellulose‐polyaniline membranes was investigated. Kinetic experiments showed a rapid adsorption of this complex, which was attributed to an ion‐exchange mechanism. Equilibrium adsorption results were represented by the Langmuir model, showing a correlation coefficient of 0.9852. Langmuir parameters K and Qm were found to be 0.2937 L mg−1 and 1.2394 mg g−1, respectively. Approximately 94% of AuI was adsorbed when a solid/liquid ratio of 40 g L−1 (grams of membrane/ liter of solution) was used. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Treatment of relapsing polychondritis with rituximab: A retrospective study of nine patients
Authors: Leroux Gaëlle , Costedoat‐Chalumeau Nathalie , Brihaye Benoît , Cohen‐Bittan Judith , Amoura Zahir , Haroche Julien , Limal Nicolas , Bletry Olivier , Piette Jean‐Charles
Published: April 2009

Objective

Rituximab, a chimeric monoclonal antibody directed against the CD20 antigen expressed by B cells, is now considered an effective second‐line therapy in various systemic diseases. We describe here the effects of rituximab in patients with relapsing polychondritis.

Methods

This was a retrospective study of 9 patients with relapsing polychondritis who received different regimens of rituximab in addition to their ongoing therapies. Clinical, laboratory, physiologic, and radiologic indicators were used to assess disease activity. We also examined their corticosteroid doses and any change in immunosuppressive agents. We then compared disease activity in the 6 months preceding rituximab administration and at 6 and 12 months after.

Results

At 6 months, 2 patients showed partial improvement, 4 were stable, and 3 had worsened disease; however, no patient had complete remission. At 12 months (after exclusion of the 3 patients whose disease had worsened at 6 months), 2 patients remained stable and 4 had worsened disease; however, there were no partial or complete remissions. B cells were counted in 8 patients during the first 6 months after treatment, and B cell depletion was observed in all of the patients.

Conclusion

Although we cannot rule out the possibility that rituximab had a small effect, our patients' clinical courses did not improve significantly with this treatment.
Epidemiology and clinical characteristics of behçet's disease in the US: A population‐based study
Authors: Calamia Kenneth T. , Wilson Floranne C. , Icen Murat , Crowson Cynthia S. , Gabriel Sherine E. , Kremers Hilal Maradit
Published: April 2009

Objective

Behçet's disease (BD) is a rare, multisystem inflammatory disorder of unknown cause. Although well‐documented in Eastern populations, epidemiologic data is scarce in North American countries. Here we describe the incidence and prevalence of BD in Olmsted County, Minnesota over 45 years.

Methods

We identified an incidence cohort of subjects age ≥18 years who had a clinical diagnosis of and/or fulfilled the International Study Group (ISG) criteria for BD from January 1, 1960 to January 1, 2005. Age‐ and sex‐specific incidence and prevalence were estimated and age‐ and sex‐adjusted to the 2000 US total population.

Results

The study population was comprised of 13 subjects with BD; 11 fulfilled ISG criteria between 1960 and 2005. Mean ± SD age was 31 ± 9 years, and 69% were white. Point prevalence in 2000 was 5.2 per 100,000 population (95% confidence interval [95% CI] 0.64–9.84). The overall annual age‐ and sex‐adjusted incidence of BD was 0.38 per 100,000 population (95% CI 0.17–0.59), with a higher incidence in women (0.51 per 100,000; 95% CI 0.17–0.84) than in men (0.26 per 100,000; 95% CI 0.004–0.52). Dermatologic lesions included oral ulcers (100%), genital ulcers (62%), erythema nodosum (46%), and papulopustular lesions (54%). Ocular lesions, vascular complications, and central nervous system involvement were present in 8, 3, and 3 subjects, respectively.

Conclusion

Our study shows an overall incidence of 0.38 per 100,000 population, which is comparable with other Western populations. The prevalence of 5.2 per 100,000 population is similar to estimates reported in Western countries, but lower than that in countries along the Silk Road.
Chlamydiae as etiologic agents in chronic undifferentiated spondylarthritis
Authors: Carter John D. , Gérard Hervé C. , Espinoza Luis R. , Ricca Louis R. , Valeriano Joanne , Snelgrove Jessica , Oszust Cynthia , Vasey Frank B. , Hudson Alan P.
Published: April 2009

Objective

The majority of patients with Chlamydia‐induced reactive arthritis do not present with the classic triad of arthritis, conjunctivitis/iritis, and urethritis. Moreover, acute chlamydial infections are often asymptomatic. The aim of the present study was to assess the prevalence of synovial Chlamydia trachomatis and Chlamydia pneumoniae infections in patients with chronic undifferentiated spondylarthritis (uSpA).

Methods

Study patients met the European Spondylarthropathy Study Group criteria for SpA, without evidence of ankylosing spondylitis, psoriasis, inflammatory bowel disease, or preceding dysentery. Symptoms were present for ≥6 months. Each patient underwent a synovial biopsy; tissue and concomitantly obtained peripheral blood mononuclear cells (PBMCs) were analyzed by polymerase chain reaction (PCR) for C trachomatis and C pneumoniae DNA. Other data collected on the day of the biopsy included standard demographic information and medical history, including any known history of C trachomatis or C pneumoniae. Physical examination (including joint count, evaluation for dactylitis and/or enthesitis, and skin examination) and HLA–B27 typing were performed. Synovial tissue (ST) samples from 167 patients with osteoarthritis (OA) were used as controls.

Results

Twenty‐six patients met the entry criteria and underwent synovial biopsy (25 knee, 1 wrist). Sixteen of them (62%) were positive for C trachomatis and/or C pneumoniae DNA (10 for C trachomatis, 4 for C pneumoniae, and 2 for both). PCR analysis of ST revealed the presence of Chlamydia significantly more frequently in patients with uSpA than in OA controls (P < 0.0001). No specific clinical characteristics differentiated Chlamydia‐positive from Chlamydia‐negative patients. PBMCs from 4 of the 26 uSpA patients (15%) were positive for Chlamydia, and Chlamydia was found in ST from 2 of these 4 patients. No significant correlation between PCR positivity and HLA–B27 positivity was found.

Conclusion

The frequency of Chlamydia‐positive ST samples, as determined by PCR, was found to be significantly higher in patients with uSpA than in patients with OA. Our results suggest that in many patients with uSpA, chlamydial infection, which is often occult, may be the cause.