bluuebunny/crossref_metadata_2025 huggingface dataset:
New Poly(oxyethylene) Derivatives from Diels–Alder Reactions of 3‐[Methoxypoly(oxyethylene)]methylene Furan
Authors: Sedaghat‐Herati Reza , Chacon Almary , Hansen Mary E. , Yalaoui Skander
Published: September 2005

Summary: A new poly(ethylene glycol) derivative, 3‐[methoxypoly(oxyethylene)]methylene furan, I, was prepared from the reaction of 3‐furanmethanol with the mesylate of methoxypoly(oxyethylene) in tetrahydrofuran. The degree of end‐group conversion, as determined by NMR spectroscopy, was 100%. The Diels–Alder reactions of I with N‐phenylmaleimide, N‐glycinylmaleimide, maleic anhydride, N,N′‐hexamethylene bismaleimide, and diethyl acetylenedicarboxylate resulted in the corresponding adducts. For the adduct derived from I and N‐phenylmaleimide, its thermal reversible character was confirmed by applying a retro‐Diels–Alder reaction in the presence of a large excess of 2‐methylfuran, which restored the initial polymer I quantitatively. The adduct obtained from I and N‐glycinylmaleimide was converted into its succinimidyl ester and its hydrolysis rate in phosphate buffer (pH = 8) was determined. The reactivity of the adduct derived from I and N,N′‐hexamethylene bismaleimide with benzyl mercaptan was also investigated.

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Synthesis of Polyolefins Containing Silacycloalkane Units in the Main Chain, 1
Authors: Naga Naofumi
Published: September 2005

Summary: Copolymerizations of ethylene and disubstituted diallylsilanes (CH2CHCH2)2R2Si (R = CH3, C6H5) have been investigated with various zirconocene catalysts using methylaluminoxane as a cocatalyst. The bridged stereospecific catalysts showed a higher reactivity for disubstituted diallylsilanes than the non‐bridged aspecific catalysts. Disubstituted diallylsilanes were incorporated into the polymer chain via cyclization insertion preferentially, and formed 3,5‐disubstituted silacyclohexane units in the polyethylene main chain. A zirconocene catalyst, dimethylsilylenebis(indenyl)zirconium dichloride, produced a copolymer containing pendant allyl groups derived from the 1,2‐insertion of diallyldiphenylsilane without cyclization.

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Cover Picture: Macromol. Chem. Phys. 18/2005
Authors: Wangsoub Supatra , Olley Robert H. , Mitchell Geoffrey R.
Published: September 2005

Cover: Time‐resolving SAXS shows that the application of modest levels of shear flow to a poly(ε‐caprolactone) melt containing dibenzylidene sorbitol leads to self‐assembled highly extended nanoparticles which on cooling direct the polymer crystallisation to yield a high level of lamellar orientation. Further details can be found in the Full Paper by S. Wangsoub, R. H. Olley and G. R. Mitchell* on page 1826.
The cultural shaping of scholarly communication: Explaining e‐journal use within and across academic fields
Authors: Fry Jenny , Talja Sanna
Published: September 2005

Current research on e‐journal usage patterns focuses more on measuring levels of use and measuring changes in reading patterns than developing theoretical models that enable the explanation and prediction of patterns in the adoption and uptake of e‐journals across scientific fields. Typically, studies either focus on single disciplines or attempt to reach an overview of disciplinary differences by using broad disciplinary groupings, such as physical sciences, health sciences, applied technologies, social sciences, or humanities. We argue that there is a need for extending the domain analytic approach to incorporate a fuller understanding of the cultural characteristics of scientific specialisms, which include both epistemological and social considerations. To this end we suggest that Whitley's theory of the social organization of scholarly fields can be effectively used as an explanatory model of e‐journal use across scientific fields. By using Whitley's theory we also illustrate the limitation of current approaches to the explanation of information practices and e‐journal use that use the administrative unit of the discipline, or base comparison on coarse‐grained aggregations as the unit of analysis, rather than the specialism.
Evolution of the interdisciplinary characteristics of information and library science
Authors: Tang Rong
Published: September 2005

An empirical investigation of citations to 150 publications in the field of Information and Library Science (ILS) has enabled mapping of the development of the interdisciplinary scope of the ILS field. The publications were drawn randomly in six years between 1975 and 2000, with 25 articles each from the selected years. Network‐based graphical presentation of number of extradisciplinary citations show that the field attracts a significant wide spectrum of disciplines in the domains of science, social science, and the humanities, and that the kinds of disciplines interested in the field vary by year. ANOVA result based on the number of extradisciplines was significant and the linear contract between the year group of 1975,1980,1985 and the year group of 1990,1995, 2000 was highly statistically significant. Interdisciplinary diversity was further examined through measures of Citations Outside Category and Brillouin's Index. Kruskal Wallis test showed significant results, however, when the two measures were considered independently, only the contrast of the year of 1990 to the prior three years was significant.
Use of electronic science journals in the undergraduate curriculum: An observational study
Authors: Tenopir Carol , Wang Peiling , Pollard Richard , Zhang Yan , Simmons Beverly
Published: September 2005

Phase 2 of a 2‐phase project funded by the NSF–National Science Digital Library Project observed undergraduate and graduate engineering, chemistry, and physics students and faculty while they searched the ScienceDirect e‐journals system for scholarly science journal articles for simulated class‐related assignments. Think‐aloud protocol was used to capture affective and cognitive state information, while online monitoring provided an automatic log of interactions with the system. Pre‐and post‐search questionnaires and a learning style test provided additional data. Preliminary analysis shows differences in search patterns among undergraduates, graduates, and faculty. All groups used basic search functions the most. Graduate students on average spent more time per session and viewed more pages. Further analysis, including analysis of affective and cognitive reactions is continuing.
Library portals: The impact of the library information environment on information seeking success
Authors: Detlor Brian , Lewis Vivian
Published: September 2005

This paper raises awareness of the impact, both positive and negative, of a library's information environment on library portal design and usability in terms of information seeking. The authors propose that healthy information environments lay the groundwork for effective end‐user searching and browsing. Deficiencies in the information environment place constraints on a library portal's functionality and form, thereby inhibiting searching and browsing. A case study of the McMaster University Library Gateway is put forward to illustrate the influence of a library's information environment on portal design and, ultimately, information seeking success. Several recommendations are made on ways to instill healthy information environments which better support a full range of end‐user information seeking behaviors. Though libraries may be unable to change all aspects of their information environments, they should be aware of the impact these aspects have on library portal adoption and use and take steps to minimize any resultant negative effects.
Keeping and re‐finding information on the web: What do people do and what do they need?
Authors: Bruce Harry , Jones William , Dumais Susan
Published: September 2005

This study (Keeping Found Things Found ‐KFTF) investigated the methods that people use in their workplace to re‐access web information. People were observed using many different methods to keep web information for later use including the use of Bookmarks (or Favorites), self‐addressed email, hand‐written notes, and paper print‐outs. Each keeping method provided a range of functions but none of the observed methods allowed for all desired functions. Participants in the KFTF study were also tested for their ability to return to a web site and several re‐finding methods were observed and identified. When prompted with web site descriptions they had generated three to six months earlier, participants had a 95% or better success rate in returning to the cued‐for web sites. Moreover, two thirds of these re‐finding methods required no explicit keeping behavior. Common re‐finding methods included the use of: 1.) A search service. 2.) Partial completion of a site's web address and acceptance of a suggested completion to this address (the auto‐complete function). 3.) Hyperlinks from another web site. Results underline the importance of a reminding function. This paper also reports the data collected from a web survey conducted after the keeping and re‐finding observations. 214 participants completed the survey. The data from the survey validated and elaborated the various methods that people use to keep web information for later re‐use that were identified in earlier observational studies.
A case study of communication channels in a graduate program
Authors: Huang Sheng‐Cheng , Chen Chao‐Hsiu , Chen Hsin‐Liang
Published: September 2005

The investigators attempt to obtain a thorough understanding of the communication channels used in a graduate program, which is an independent academic unit. After collecting data with qualitative and quantitative research methods, the investigators analyze and present the findings regarding four major aspects: (1) the current communication channels used in the program; (2) how the students, faculty and staff perceived the communication methods utilized; (3) the relationship between students' viewpoints and the program's perspectives, and (4) suggestions for further improvement in the distribution of information.
Public access to information and the creation of an ‘information commons’
Authors: Rao Robert , Wiseman Erica , Dalkir Kimiz
Published: September 2005

Intellectual property (IP) and intellectual property rights (IPRs) have increased in social, political, and economic importance in North America over the past two decades. There has been much talk of how we have, or are currently in the process of shifting to, an ‘information economy’ and an ‘information society’; and indeed, ‘information’ has become an increasingly valuable property, in the form of books, music, motion pictures, and corporate logos and designs. The major holders of this valuable IP have worked hard to have the laws protecting IPRs strengthened, with various consequences for public accessibility. The first part of this paper begins with a brief definition of copyright and a description of just what copyright was originally designed to protect. The second part of this paper focuses on the alternatives to copyright that are being developed in the digital realm, particularly for computer software and the Internet. As part of the battles that are currently being fought over control of this relatively new and somewhat unregulated medium of distribution, we will focus on the ‘open source’ software movement and the attempts to create ‘information commons’ that act to ensure the widest possible public accessibility to information.
Information task switching and multitasking web search
Authors: Spink Amanda , Park Minsoo , Jansen Bernard J.
Published: September 2005

A user's single session with a Web search engine may consist of seeking information on single or multiple topics. Some Web search sessions consist of three queries of one word or more. We present findings from a study of three or more‐query search sessions on the Alta Vista Web search engines. We examine the degree of multitasking search and information task switching by these Web searchers. A sample of three or more query sessions were filtered from Alta Vista transaction logs from 2002 and qualitatively analyzed. Findings include: (1) 91.3% of three or more query sessions contained multiple topics, (2) multitasking sessions contained frequent topic changes, and (3) there are a broad variety of search topics in multitasking search sessions. Multitasking is a key element within Web search. The implications of our findings for Web design and further research are discussed.
The appropriate (and inappropriate) use of query operators and their effect on web search results
Authors: Eastman Caroline M. , Jansen Bernard J.
Published: September 2005

In previous work, we showed that the use of Boolean and other operators in queries to Web search engines has little impact on the quality of the results retrieved. This earlier study used 100 queries containing operators selected from a search engine query log. The operators were removed from the queries, and both query versions (with and without operators) were submitted to three popular search engines. There was no significant difference in number of relevant results retrieved in the top 10 items.

In this work, we revisit the queries used in this earlier study to examine the manner in which the operators were used. At that time the reason for the relatively low impact of the query operators was not addressed in detail. For each query, the operator used was classified based upon semantic appropriateness and anticipated impact. Most query operators were used in a semantically appropriate manner. This finding suggests that the reason for the relatively low impact of operators on retrieval results was not inappropriate or incorrect use of the operators.
Investigating automated assistance and implicit feedback for searching systems
Authors: Jansen Bernard J. , McNeese Michael D.
Published: September 2005

Information retrieval systems offering personalized automated assistance have the potential to improve the searching process. There has been much work in this area for several years on a variety of systems. However, there has been little empirical evaluation of automated assistance to determine if it is of real benefit for searchers. We report the results of empirical evaluation investigate how searchers use implicit feedback and automated assistance during the searching process. Results from the empirical evaluation indicate that searchers typically use multiple implicit feedback actions, usually bookmark – copy. The most commonly utilized automated assistance was for query refinement, notable the use of the thesaurus. We discuss the implications for Web systems and future research.
Visual search editor for composing meta searches
Authors: Spoerri Anselm
Published: September 2005

MetaCrystal is visual tool for creating and editing meta search queries. Users can visually combine the top results retrieved by different search engines to create crystals of increasing complexity. MetaCrystal consists of several overview tools to help users gain insight into how to filter the results from the different engines. It shows users the degree of overlap between the top results returned by different search engines. Users can apply different weights to the search engines to create their own ranking functions and can perform advanced filtering operations visually. Users can modify the URL directory depth or change the number of top documents used to increase or decrease the degree of overlap between the different engines. MetaCrystal addresses the problem of the effective fusion of different search engine results by enabling user to visually compose and refine meta searches.
Speak now and forever record your piece: Information use in technical trouble tickets
Authors: Marlow David W. , Nyce James M.
Published: September 2005

Based on a bimodal approach combining elements of the ethnography of communication and organizational genre analysis, this study examines the text of a large corpus of trouble ticket discourse. Key findings involve the fragmentary nature of trouble ticket text, the role the system plays in the use of information, the duality of writers' intention for the use of information, and the collaboratively concatenative generation of trouble tickets.

Directions for future study include the evolution of the trouble ticket genre over time, the affect of gender on communicative style, readers' reactions to trouble tickets, and the role of trouble tickets play in organizational memory.
Managing and assessing internet service needs and use of under‐served populations at public libraries
Authors: Kim Yunkeum
Published: September 2005

As the range of public library services with new technology has diversified, defining, measuring, assessing and managing the quality of these electronic services has become a critical issue. Internet connections at public libraries have increased dramatically since 1990 due to the availability of key external funding sources. The major goal of those funding sources was to expand public access to Computers and digital information, especially for the public of low‐income or under‐served populations; thus, there has been continuing increase in public library Internet services at the library, for example, the services at Internet workstations. Although there have been attempts to measure the performance of public library network services by library and information science researchers using network statistics based on “technical‐driven” performances, there has been little research dealing with service quality and satisfaction of Internet service users at the public libraries based on “user‐driven” performance evaluation. This paper describes the process of survey research using 386 Internet service users at four public libraries and discusses how public libraries need to approach those under‐served populations' Information needs and use at Internet workstations which can expand the possibility of new direction for future public library Internet services.
A conceptual framework for the holistic measurement and cumulative evaluation of library services
Authors: Nicholson Scott
Published: September 2005

This conceptual piece presents a framework to aid libraries in gaining a more thorough and holistic understanding of their users and services. Through a presentation of the history of library evaluation, a measurement matrix is developed that demonstrates the relationship between the topics and perspectives of measurement. These measurements are then combined through evaluation criteria, and then different participants in the library system view those criteria for decision‐making. By implementing this framework for holistic measurement and cumulative evaluation, library evaluators can gain a more holistic knowledge of the library system and library administrators can be better informed for their decision‐making processes.
Rank‐normalized impact factor: A way to compare journal performance across subject categories
Authors: Pudovkin Alexander I. , Garfield Eugene
Published: September 2005

It is well known that uninformed science administrators often use ISI's journal impact factors without taking into account the inherent citation characteristics of individual scientific disciplines. A rank normalized impact factor (rnlF) is proposed which involves use of order statistics for the complete set of journals within each JCR category. We believe the normalization procedure provides reliable and easily interpretable values. For any journal j, its rnlF is designated as rnlF1and equals (K–R1+ 1)/K, where R1 is the descending rank of journal j in its JCR category and K is the number of journals in the category. Note: JCR impact factor listings are published in descending order. The proposed rnlF is compared with normalized impact factors proposed by earlier authors. The efficacy of the rnlF is illustrated in the cases of seven highly‐cited scientists, one each from seven different fields.
Can web citations be a measure of impact? An investigation of journals in the life sciences
Authors: Vaughan Liwen , Shaw Debora
Published: September 2005

We examine traditional and Web citations to journal articles in biology and genetics. There is significant correlation between citations in these two formats. Journals with higher numbers of Web citations tend to have more citations indicating intellectual impact (citations from papers or class readings, in contrast to citations from bibliographic services or the author's or journal's home page). Web citations show a broader geographic coverage and capture a greater number and variety of uses of journal articles.
Well‐posedness of two‐shape memory model
Authors: Chemetov N.
Published: September 2005

The aim of this paper is to study shape memory alloys which admit two shape memory effect. This effect results from progressive modification of the admissible mixture of martensites and austenite. The predictive theory of this education phenomenon has been developed by Frémond. We discuss the education model of Frémond and establish the solvability and uniqueness results. Copyright © 2005 John Wiley & Sons, Ltd.
Outcome of urethral closure in patients with neurologic impairment and complete urethral destruction
Authors: Stoffel John T. , McGuire Edward J.
Published: September 2005

Aims

The purpose of this study is to describe the problems associated with prolonged urethral catheterization in 12 patients with neurological problems and to report the results of surgical treatment.

Methods

A retrospective study of patients with neurogenic bladder and urethral dysfunction treated with prolonged catheterization resulting in incontinence associated with loss of urethral tissue and or function selected 12 patients. All had video urodynamics. Twelve were continuously incontinent despite a catheter. Bladder compliance, where that could be measured, was low is 10, and there were multiple and serious co‐morbidities including sepsis, hypoalbuminemia, skin breakdown, osteomyelitis, respiratory insufiency, etc. There were 4 males and 8 females, 9 had a spinal cord injury and 3 progressive multiple sclerosis.

Results

Male patients underwent transperineal closure of the membranous urethra; females transvaginal closure of the urethra. All patients had a urinary diversion, either an ileovesicostomy, or an augmentation cystoplasty and construction of a neourethra. Continence was ultimately achieved in 11 of 12 patients at a median 20 months. Four patients had one additional procedure to gain continence, but five patients required 3.8 procedures/patient to achieve continence. Closure of the male urethra was more easily accomplished than closure of an extensively damaged eroded female urethra.

Conclusions

Patients with urethral damage and erosion related to prolonged catheter present a formidable challenge in surgical reconstruction. Most have serious co‐mobidities and a single operation does not usually solve all the problems. Persistence does almost always result in continence. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
Visceral and cutaneous sensory testing in patients with painful bladder syndrome
Authors: FitzGerald Mary P. , Koch Dorothea , Senka Judith
Published: September 2005

Aims

Our aims were to determine whether subjects with painful bladder syndrome (PBS) demonstrate characteristics of visceral pain syndromes: visceral hyperalgesia, expanded loci of referral of bladder sensation, increased bladder pain with repetitive filling, lower thresholds to cutaneous stimulation in relevant dermatomes, abnormal response to repetitive cutaneous stimulation in relevant dermatomes, and also to develop easily applied measures for PBS pain evaluation and management.

Methods

We recruited PBS subjects and control subjects with no bladder pain and with either stress urinary incontinence (SUI) or no incontinence. Subjects underwent three bladder fills up to maximum 300 ml and mapped bladder fullness/discomfort, rating any pain present. Cutaneous current perception thresholds (CPTs) were tested at 2000 Hz, 250 Hz, 5 Hz at C5, T6, T10, T12, S3 dermatomes. Repetitive supra‐threshold stimulation in trains of 15 stimuli 2 sec apart were then administered to T12, S3 dermatomes.

Results

PBS subjects demonstrated hyperalgesia to bladder filling and tended to sense bladder discomfort at both suprapubic and vulvar/urethral sites. There was no difference in CPTs at any dermatome at any stimulating frequency. PBS and SI subjects tended not to habituate to repetitive stimuli, while asymptomatic controls tended to habituate to repetitive stimulation.

Conclusions

PBS subjects demonstrate bladder hyperalgesia and may sense bladder discomfort at sites other than suprapubic. Rating of bladder discomfort and sensory mapping during cystometry usefully distinguishes between PBS subjects and controls. Neurourol. Urodynam. © 2005 Wiley‐Liss, Inc.
Transshipment through crossdocks with inventory and time windows
Authors: Lim Andrew , Miao Zhaowei , Rodrigues Brian , Xu Zhou
Published: September 2005

A major challenge in making supply meet demand is to coordinate transshipments across the supply chain to reduce costs and increase service levels in the face of demand fluctuations, short lead times, warehouse limitations, and transportation and inventory costs. In particular, transshipment through crossdocks, where just‐in‐time objectives prevail, requires precise scheduling between suppliers, crossdocks, and customers. In this work, we study the transshipment problem with supplier and customer time windows where flow is constrained by transportation schedules and warehouse capacities. Transportation is provided by fixed or flexible schedules and lot‐sizing is dealt with through multiple shipments. We develop polynomial‐time algorithms or, otherwise, provide the complexity of the problems studied. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
A Cauchy‐stress based solution for a necking elastic constitutive model under large deformation
Authors: Olley P.
Published: September 2005

A finite element based method for solution of large‐deformation hyperelastic constitutive models is developed, which solves the Cauchy‐stress balance equation using a single rotation of stress from principal directions to a fixed co‐ordinate system. Features of the method include stress computation by central differencing of the hyperelastic energy function, mixed integration‐order incompressibility enforcement, and an iterative solution method that employs notional ‘small strain’ stiffness. The method is applied to an interesting and difficult elastic model that replicates polymer ‘necking’; the method is shown to give good agreement with published results from a well‐established finite element package, and with published experimental results. It is shown that details of the manner in which incompressibility is enforced affects whether key experimental phenomena are clearly resolved. Copyright © 2005 John Wiley & Sons, Ltd.
Numerical investigation of the stress field of particulate reinforced polymeric composites subjected to tension
Authors: Kakavas Panayiotis A. , Kontoni Denise‐Penelope N.
Published: September 2005

The aim of the present study is the detailed numerical investigation of the stress/strain distribution in polymeric matrix composites reinforced with spherical inclusions, using the finite element method (FEM). Perfect adhesion between the matrix and the inclusions was assumed and from the computed stress/strain profiles of the system, debonding initiation and propagation can easily be predicted. Analytical models available in the literature may predict the stress/strain distribution within the inclusion and along the matrix/inclusion interface, while the FEM may yield results for the whole composite, including within the inclusions. Three typical volume fractions of the composite were examined and the results were justified by the analytical predictions of other researchers. The numerical results show that the matrix starts to debond from the inclusions at angular distance forty‐five degrees and as the applied load increases the debonding zone gradually extends. Copyright © 2005 John Wiley & Sons, Ltd.
Scanning for chorionicity: comparison between sonographers and perinatologists
Authors: Weisz Boaz , Pandya Pranav , Dave Raj , Jauniaux Eric
Published: September 2005

Objective

In most prenatal settings, twin pregnancies are initially evaluated by sonographers. Pregnancies diagnosed as monochorionic are subsequently referred to perinatologists or specialists in fetal medicine for the confirmation of chorionicity. In order to assess this screening strategy, we have compared the diagnosis of chorionicity made by the sonographers in the ultrasound department with the diagnosis done in the fetal medicine unit.

Methods

A cohort of women presenting with twin pregnancy and booked for prenatal care at University College London Hospitals over a 4‐year period were investigated prospectively. All women were scanned at their initial visit at 11–14 weeks in the ultrasound department (US), and were subsequently referred to the Fetal Medicine Unit (FMU) for a second ultrasound evaluation. Ultrasound data were compared and diagnosis of chorionicity was confirmed by examination of the inter‐twin membranes after delivery.

Results

Chorionicity was determined in 172 twin cases by the two different departments. The overall rate of concordant chorionicity determination between both units was 90.1%. The rate of discordant results in dichorionic pregnancies was extremely small, 1 in 119 pregnancies (0.8%). The rate of discordant results for monochorionic diamniotic pregnancies was 5.5%. Monoamniotic pregnancies were over‐diagnosed by the US technicians.

Discussion

These results demonstrate that DC/DA chorionicity is accurately determined by sonographers at less than 14 weeks. In our opinion, it is both efficient and safe to rely on the diagnosis of the sonographers in DC/DA pregnancies in early pregnancy. In such pregnancies, a decision can be made either not to refer these patients for further evaluation of chorionicity by the fetal medicine team or to postpone the referral to after 14 weeks. Copyright © 2005 John Wiley & Sons, Ltd.
Prenatal screening for Down syndrome and neural tube defects in twin pregnancies
Authors: Wald Nicholas J. , Rish Simon
Published: September 2005

Prenatal screening and diagnosis in a twin pregnancy is not straightforward. Once a twin pregnancy has been identified, women and their partners need time to consider the implications and decide whether they wish the pregnancy to be screened for Down syndrome or neural tube defects. We discuss here how multiple marker screening for Down syndrome and alpha‐fetoprotein screening for neural tube defects can be carried out, given that this is the parents' chosen option and that the health professionals involved are capable of performing a diagnosis and selective feticide, should this arise. Copyright © 2005 John Wiley & Sons, Ltd.
Prenatal diagnosis and management of twin pregnancies complicated by a co‐existing molar pregnancy
Authors: Wee Ling , Jauniaux Eric
Published: September 2005

Recent advances in ultrasound and molecular genetics have increased our understanding and hence enhanced the perinatal management of complete and partial hydatidiform mole. By contrast, the management of a twin pregnancy combining a normal pregnancy with a normal fetus and a complete hydatidiform mole (CHM) remains complex and controversial due to conflicting data from different parts of the world. The aim of this review is to analyse the international literature on twin pregnancies that include a mole, present the complications and outcome of pregnancy and to discuss the perinatal management. Management is complicated and women should be counselled about the maternal and fetal complications, and the pregnancy monitored carefully by a perinatal team with experience in high‐risk obstetrics and access to neonatal care. The data reviewed here suggest that a woman who decides to continue with the pregnancy including a CHM must be aware that, overall, she only has a one in four chance of live birth and in around 35% of cases she will develop persistent trophoblastic disease (PTD) after delivery. In ongoing pregnancies, there will be, in at least 20% of the cases, an early onset of pre‐eclampsia (PET) and a 29% risk of fetal loss due to late miscarriage, intrauterine death and neonatal death. Maternal serum human chorionic gonadotrophin (MShCG) could be useful in predicting outcome in twin pregnancy combining normal pregnancy and CHM, but this needs to be investigated prospectively. Copyright © 2005 John Wiley & Sons, Ltd.
Modification of microstructures and physical properties of ultra high molecular weight polyethylene by electron beam irradiation
Authors: Lee Sang Man , Choi Sun Woong , Nho Young Chang , Song Hyun Hoon
Published: September 2005

An ultra high molecular weight polyethylene was irradiated with the electron beam at dose levels ranging from 100 kGY to 1 MGy. The microstructures of the irradiated samples were characterized by FTIR, gel fraction measurement, DSC, and small‐ and wide‐angle X‐ray scattering. For the mechanical properties, a static tensile test and creep experiment were also performed. The crosslinking and the crystal morphology changes were the main microstructural changes to influence the mechanical properties. It was found that 250 kGy appeared to be the optimal dose level to induce crosslinks in the amorphous area and recrystalliztion in the crystal lamellae. At doses above 250 kGy, the electron beam penetrates into the crystal domains, resulting in crosslinks in the crystal domains and reduction in the crystal size and crystallinity. The static mechanical properties (modulus, strength) and the creep resistance were enhanced by the electron beam irradiation. The stiffness rather correlated with the degree of crosslinks while the strength with the crystal morphology. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3019–3029, 2005
Fabrication of Bioactive Surfaces by Plasma Polymerization Techniques Using a Novel Acrylate‐Derived Monomer
Authors: Francesch Laia , Garreta Elena , Balcells Mercedes , Edelman Elazer R. , Borrós Salvador
Published: September 2005

Summary: Material coating of surfaces can enhance receptivity for cells and biological compounds. Existing plasma coating technologies and possible materials are limited. A new polymer from pentafluorophenyl methacrylate (PFM) monomer was synthesized, and was plasma enhanced chemical vapor deposited on silicon wafers. The optimal plasma polymerization parameters for the PFM monomer and its copolymerization with the cross‐linking agents 1,7‐octadiene and 1,4‐butanediol divinyl ether co‐monomers were established. All the resulting polymer coatings leave the labile pentafluorophenyl group on the surface, enabling a rapid reaction with an amino‐terminated biotin ligand and allowing layer‐by‐layer self‐assembly of biotin‐streptavidin. In addition, the deposited polymer layers showed an extremely flat morphology with a nanoscale average roughness. This approach provides an easy means of obtaining functionalized surfaces which can enhance and control the biocompatibility of bulk materials. Merging the versatility of plasma polymerization processes, via simple monomers and reaction conditions, with biological platforms that enable target of cell adhesion brings us closer to the ultimate goal of controlling cell function through structured surfaces for their application in tissue engineering.

Schematic representation of a functionalized surface obtained by plasma polymerization of the PFM monomer, showing labile pentafluorophenyl groups on the surface.

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Schematic representation of a functionalized surface obtained by plasma polymerization of the PFM monomer, showing labile pentafluorophenyl groups on the surface.
Improvement of Surface Properties of Poly(propylene) Hollow Fiber Microporous Membranes by Plasma‐Induced Tethering of Sugar Moieties
Authors: Yu Hai‐Yin , Hu Meng‐Xin , Xu Zhi‐Kang
Published: September 2005

Summary: Hydrophobic poly(propylene) hollow fiber microporous membranes (PPHFMMs) were surface‐modified by nitrogen plasma‐induced tethering of α‐allyl glucoside (AG). Their antifouling characteristics in a submerged membrane bioreactor (SMBR) were investigated. The chemical composition of the modified and unmodified PPHFMMs was characterized by X‐ray photoelectron spectroscopy (XPS). Water contact angle was measured by the sessile drop method. Results of XPS clearly indicated that sugar moieties could be tethered on the membrane surface. Water contact angle on the modified membrane showed a minimum value of 64°, approximately 64° lower than that on the unmodified membrane. After continuous operation in a SMBR for about 160 h, the flux recovery, the reduction of flux and the relative flux ratio for the modified PPHFMMs were 17.8% higher, 5.1% lower and 140% higher than those of the nascent one, respectively.

Schematic representation of plasma‐induced tethering of α‐allyl glucoside on a PPHFMM surface.

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Schematic representation of plasma‐induced tethering of α‐allyl glucoside on a PPHFMM surface.
Microscope Raman scattering and X‐ray diffraction study of near‐stoichiometric Ti:LiNbO3 waveguides
Authors: Zhang De‐Long , Siu G. G. , Pun E. Y. B.
Published: September 2005

The crystalline phase within guiding layers of near‐stoichiometric strip and planar Ti:LiNbO3 wave‐guides, prepared by the method of simultaneous work of vapour transport equilibration (VTE) treatment and indiffusion of Ti film, was studied by combined confocal microscope Raman scattering and X‐ray powder diffraction. The results show that the strip and planar waveguide layers still retain the LiNbO3 phase and no other non‐LiNbO3 phases can be identified within the guiding layer. Li/Nb ratios inside and outside the strip and planar waveguide layers were determined from the microscope Raman scattering results and compared to those obtained from the measured optical absorption edge. It is shown that the Li/Nb ratios are homogeneous within the waveguide layer and are close inside and outside the waveguide layer. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Dislocation indentation size effect in KCl single crystals
Authors: Soifer Ya. M. , Verdyan A.
Published: September 2005

A systematic range of nanoindentation measurements on (001) KCl single crystals was performed to differentiate between true size effects and other factors that can give rise to an apparent increase in hardness. The hardness and Young's modulus values were determined by combining the load–displacement data with measurement of the topography of the residual indent using atomic force microscopy (AFM). AFM data allowed the estimation of the true contact area, subsequently used to recalculate the hardness and Young's modulus of the material more accurately. It was shown that there was an apparent increase in hardness as the applied load decreased. The results obtained were considered in terms of different dislocation models describing the indentation size effect involving models based on both bulk and surface effects. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The stress field of a dislocation array in an ultra thin anisotropic heterogeneous bicrystal
Authors: Benbouta Rachid , Mihi Abdelkader , Brioua Mourad , Madani Salah , Adami Lahbib
Published: September 2005

The problem of a dislocation parallel and close to two free surfaces of a thin foil made up of two plates of different nature, using anisotropic elasticity, is treated numerically. Different applications are presented for the thin homogeneous crystals Al/Al and Cu/Cu and also for the thin bicrystal Al/Cu. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Antioxidant effect of squeezed juice from black radish (Raphanus sativus L. var niger) in alimentary hyperlipidaemia in rats
Authors: Lugasi Andrea , Blázovics Anna , Hagymási Krisztina , Kocsis Ibolya , Kéry Ágnes
Published: September 2005

Black radish (Raphanus sativus L. var. niger) root has been used in folk medicine since antiquity as a natural drug for the stimulation of bile function. According to in vitro studies the squeezed juice from black radish root exhibited significant antioxidant properties. In the present study, the beneficial effect of the black radish juice on some free radical reactions in rats fed with a diet rich in lipids (20% sunflower oil, 2% cholesterol, 0.5% cholic acid in normal chow) was examined. Thiobarbituric acid reactive substances and conjugated diene concentrations were significantly higher, while the antioxidant enzyme activities and the free radical scavenging capacity were lower in hyperlipidaemic rats compared with normal controls. Supplementation of the lipid‐rich diet with black radish juice resulted in a significant improvement of the parameters mentioned above. Although the exact mechanism of the biologically active compounds in black radish on the lipid metabolism and lipid peroxidation is not clear yet, a beneficial effect of the drug was evident in alimentary hyperlipidaemia. Copyright © 2005 John Wiley & Sons, Ltd.
Antibacterial activity of Curcuma longa L. against methicillin‐resistant Staphylococcus aureus
Authors: Kim Kang‐Ju , Yu Hyeon‐Hee , Cha Jung‐Dan , Seo Se‐Jeong , Choi Na‐Young , You Yong‐Ouk
Published: September 2005

Methicillin‐resistant Staphylococcus aureus (MRSA) has been emerging worldwide as one of the most important hospital and community pathogens. Therefore, new agents are needed to treat MRSA associated infections. The present study investigated the antimicrobial activity of ethyl acetate, methanol and water extracts of Curcuma longa L. (C. longa) against MRSA. The ethyl acetate extract of C. longa demonstrated a higher antibacterial activity than the methanol extract or water extract. Since the ethyl acetate extract was more active than the other extracts, the study examined whether the ethyl acetate extract could restore the antibacterial activity of β‐lactams and alter the MRSA invasion of human mucosal fibroblasts (HMFs). In the checkerboard test, the ethyl acetate extract of C. longa markedly lowered the MICs of ampicillin and oxacillin against MRSA. In the bacterial invasion assay, MRSA intracellular invasion was significantly decreased in the presence of 0.125–2 mg/mL of C. longa extract compared with the control group. These results suggest that the ethyl acetate extract of C. longa may have antibacterial activity and the potential to restore the effectiveness of β‐lactams against MRSA, and inhibit the MRSA invasion of HMFs. Copyright © 2005 John Wiley & Sons, Ltd.
Characterization of cysteinylation of pharmaceutical‐grade human serum albumin by electrospray ionization mass spectrometry and low‐energy collision‐induced dissociation tandem mass spectrometry
Authors: Kleinova Martina , Belgacem Omar , Pock Katharina , Rizzi Andreas , Buchacher Andrea , Allmaier Günter
Published: September 2005

Three samples of albumin derived from human plasma (pharmaceutical grade, HSA) obtained from different commercial sources were investigated for their micro‐heterogeneities by means of electrospray ionization (ESI) ion trap mass spectrometry (ITMS). The study covered MS analyses of the intact proteins as well as on the tryptic peptide level. The intact protein samples were analyzed without any separation step except for simple desalting. With these samples we observed in the positive ion ESI mass spectra that the multiply charged ion signals of HSA consisted of a number of fully or partly resolved peaks with relative intensities depending on the analyzed sample. The non‐modified form of HSA was detected in the three HSA preparations at m/z values of 66448 ± 3.6, 66450 ± 0.6 and 66451 ± 3.2 ([MH]+), respectively. The value calculated from the amino acid sequence was 66439. The second compound present with high intensity (in two cases the base peak in the deconvoluted mass spectrum) is interpreted as a modified HSA, and the molecular mass increase in relation to the unmodified HAS was between 116 and 118 Da (m/z of 66 564, 66 567 and 66 569), suggesting the presence of a covalently bound cysteine residue. A further peak in the deconvoluted ESI spectra was found in all three samples with rather low signal/noise ratio at m/z 66 619, 66 621 and 66 613, respectively, which may correspond to a non‐enzymatic glycation described in the literature. The verification of the proposed covalent HSA modifications was subsequently done on the peptide level using high‐performance liquid chromatography (HPLC)/ESI‐MS and HPLC/ESI‐MS/MS including low‐energy collision‐induced dissociation (CID). Prior to the tryptic digestion, the HSA samples were alkylated without a prior reduction step. Following this procedure we detected peptides of the sequence T21‐41 that included the Cys‐34 residue in both forms: cysteinylated (m/z 639.15 [M+4H]4+) as well as vinylpyridine‐alkylated (m/z 635.69 [M+4H]4+, which means in its previously native free SH form). In the next step on‐line LC/ESI low‐energy CID MS/MS experiments were performed to verify these two proposed structures. By means of MS/MS analysis of the mentioned ions the described modification (cysteinylation) at the Cys‐34 residue could be proven. This abundant modification of HSA in pharmaceutical‐grade preparations could be unambiguously identified as cysteinylation at the Cys‐34 residue. On the other hand, the proposed non‐enzymatic glycation was not detectable on the peptide level in the on‐line HPLC/ESI‐MS mode, maybe due to the low concentration in the three samples under investigation. Copyright © 2005 John Wiley & Sons, Ltd.
Diagnosis of congenital adrenal hyperplasia by rapid determination of 17α‐hydroxyprogesterone in dried blood spots by gas chromatography/mass spectrometry following microwave‐assisted silylation
Authors: Deng Chunhui , Ji Jie , Zhang Lijuan , Zhang Xiangmin
Published: September 2005

17α‐Hydroxyprogesterone (17OHP) is considered to be the biomarker of congential adrenal hyperplasia (CAH). Screening for CAH in newborns by measuring levels of the biomarker of 17OHP has become routine. In the work, a rapid, simple and sensitive technique was developed for the diagnosis of neonatal CAH by the quantitative analysis of 17OHP in neonatal blood spots. The technique was based on microwave‐assisted silylation (MAS) followed by gas chromatography/mass spectrometry (GC/MS). In the method, fast derivatization of 17OHP with N,O‐bis(trimethylsilyl)trifluoroacetamide was performed by using microwave irradiation, and the trimethylsilyl derivative thus formed was analyzed by GC/MS. The results of the experiment indicate that MAS followed by GC/MS analysis is a rapid, simple and sensitive method for the determination of 17OHP in blood samples. The proposed technique has been shown to have potential as a powerful tool for the rapid diagnosis of neonatal CAH. Copyright © 2005 John Wiley & Sons, Ltd.
Equation‐free optimal switching policies for bistable reacting systems
Authors: Armaou Antonios , Kevrekidis Ioannis G.
Published: September 2005

In the context of the recently developed equation‐free modelling framework, we present a computer‐assisted approach to locating approximate coarse optimal switching policies between stationary states of chemically reacting systems described by microscopic/stochastic evolution rules. The coarse time‐stepper constitutes a bridge between the underlying stochastic simulation and traditional, continuum numerical optimization techniques formulated in discrete time. The approach is illustrated on a simple CO oxidation on Pt catalytic surface reaction model, implemented through the Gillespie stochastic simulation algorithm. The objective sought is to switch between two coexisting stable stationary states by minimal manipulation of a macroscopic system parameter. Copyright © 2005 John Wiley & Sons, Ltd.