bluuebunny/crossref_metadata_2025 huggingface dataset:
Current and emerging treatment options in chronic myeloid leukemia
Authors: Jabbour Elias , Cortes Jorge E. , Giles Francis J. , O'Brien Susan , Kantarjian Hagop M.
Published: April 2007

Treatments for chronic myeloid leukemia (CML) represent a success story in molecular medicine. The development of imatinib, a tyrosine kinase inhibitor (TKI) targeted against the causative Bcr‐Abl oncoprotein in CML, has resulted in hematologic and cytogenetic remissions in all phases of CML. A significant proportion of patients are resistant to imatinib or develop resistance during treatment. This is often a result of mutated forms of the Bcr‐Abl oncoprotein to which imatinib is unable to bind. Several strategies have been developed to overcome the problem of imatinib resistance, including high‐dose imatinib, novel targeted agents, and combination treatments. Novel agents include dasatinib, a potent TKI that inhibits several critical oncogenic proteins and which has recently been approved for patients with CML who are resistant or intolerant to imatinib; and nilotinib, a potent selective Bcr‐Abl kinase inhibitor currently in clinical development. Other agents in development include SKI‐606 and INNO‐406. Stem cell transplantation remains a useful option, although it is not generally used as first‐line treatment. Overall, there are an increasing number of treatment options available for patients with CML. Cancer 2007. © 2007 American Cancer Society.
Clinical correlates of JAK2V617F allele burden in essential thrombocythemia
Authors: Kittur Jaya , Knudson Ryan A. , Lasho Terra L. , Finke Christy M. , Gangat Naseema , Wolanskyj Alexandra P. , Li Chin‐Yang , Wu Wenting , Ketterling Rhett P. , Pardanani Animesh , Tefferi Ayalew
Published: April 2007

BACKGROUND.

JAK2V617F occurs in approximately 50% of patients with essential thrombocythemia (ET). Qualitative studies of mutation analysis have previously reported an association between JAK2V617F and advanced age, higher hemoglobin level, higher leukocyte count, and lower platelet count. A possible association with thrombotic complication has also been considered.

METHODS.

Allele‐specific, quantitative polymerase chain reaction (PCR) analysis for JAK2V617F was performed in 176 patients with ET using genomic DNA from archived bone marrow, which was collected within 1 year (n = 72 patients), between 1 and 5 years (n = 64 patients), or after 5 years (n = 40 patients) of diagnosis.

RESULTS.

JAK2V617F was detected in 96 patients (55%), in whom mutant allele burden ranged from 1% to 100% (median, 6.3%). Neither mutational frequency (P = .37) nor mutant allele burden (P = .62) was affected by the timing of bone marrow sample collection. The presence of JAK2V617F was found to be significantly associated with higher hemoglobin level (P < .0001), lower platelet count (P = .001), higher leukocyte count (P = .008), increased incidence of venous thrombosis occurring after diagnosis (P = .02), and older age at diagnosis (P = .03). All but age retained significance in multivariable analysis. In mutation‐positive patients (n = 96 patients), JAK2V617F allele burden clustered between 1% and 22% in 94 cases, in whom it correlated directly and significantly with platelet and leukocyte counts, palpable splenomegaly at diagnosis, and venous thrombosis occurring after diagnosis. The latter 2 associations remained significant with the inclusion of the remaining 2 outlier cases with 100% mutant allele burden; in addition, an association with male gender became evident.

CONCLUSIONS.

JAK2V617F allele burden imparts additional phenotypic effects in ET. Cancer 2007. © 2007 American Cancer Society.
The abstract cauchy‐kovalevskaya theorem in a weighted banach space
Authors: Safonov M. V.
Published: April 2007

A scale of Banach spaces is considered as a single weighted Banach space. A variant of the Cauchy‐Kovalevskaya theorem is proved, including the results of Nirenberg and Nishida for the abstract nonlinear Cauchy problem. ©1995 John Wiley & Sons, Inc.
Microlocal dispersive smoothing for the Schrödinger equation
Authors: Craig Walter , Kappeler Thomas , Strauss Walter
Published: April 2007

This paper establishes a connection between the microlocal smoothness of solutions of the initial value problem for Schrödinger's equation and the global behavior of bicharacteristics of the principal symbol. In particular, localized initial data gives rise to solutions which are microlocally smooth at all points which are not trapped backwards by the bicharacteristic flow. The origin of the phenomenon is in the dispersive nature of the equation. The results imply microlocal regularity properties of the fundamental solution. ©1995 John Wiley & Sons. Inc.
Isetl: A programming language for learning mathematics
Authors: Dubinsky Ed
Published: April 2007

This paper gives a brief history of the development of an approach to help students learn mathematical concepts at the post‐secondary level. The method uses ISETL, a programming language derived from SETL, to implement instruction whose design is based on an emerging theory of learning. Examples are given of uses of this pedagogical strategy in abstract algebra, calculus, and mathematical induction. © 1996 John Wiley & Sons, Inc.
Synthesis, Structure, and Reactivity of Cerium(IV) Calix[4]arene Complexes
Authors: Gottfriedsen Jochen , Hagner Reimo , Spoida Marlies , Suchorski Yuri
Published: April 2007

The equimolar reaction of Ce(hfac)4 (1) (hfac = 1,1,1,5,5,5‐hexafluoropentanedionato) with p‐tBu‐calix[4](OMe)2(OH)2 in toluene gave the new cerium(IV) calix[4]arene complex {p‐tBu‐calix[4](OMe)2(O)2}Ce(hfac)2 (2). The single‐crystal X‐ray structure shows the cone geometry of the calixarene ligand with the methoxy groups coordinated to the cerium; it shows slightly longer cerium–oxygen (acetylacetonate ligand) bond lengths than the corresponding bonds in the analogous nonfluorinated complex {p‐tBu‐calix[4](OMe)2(O)2}Ce(acac)2 (3). The bromination reaction of 3 gave the bisbrominated complex {p‐tBu‐calix[4](OMe)2(O)2}Ce(Br‐acac)2 (4). 1H NMR spectroscopic studies and a single‐crystal X‐ray structure of 4 revealed that the bromination took place in the 3‐position of the acac ligand. Furthermore, the first X‐ray photoelectron spectroscopy (XPS) evaluation of the Ce oxidation state in cerium calix[4]arene complexes 2 and 3 is presented, and X‐ray induced changes of Ceox in these complexes are detected. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Palm oil fractionation
Authors: Kellens Marc , Gibon Véronique , Hendrix Marc , De Greyt Wim
Published: April 2007

Modification techniques like fractionation, interesterification (chemical or enzymatic) and hydrogenation allow proposing a large range of new fatty products. At a time when “trans” fatty acids are questioned, fractionation of fats and oils catches more and more interest; in this context, dry fractionation is by far the simplest and cheapest fractional crystallization technique (no chemicals, no effluent and no losses). The oil processing industry uses dry fractionation to extend the application of a whole variety of fatty matters as well as to replace, fully or partially, the chemical modifications. Due to the continuous developments of the dry fractionation process, a whole variety of products normally produced by solvent fractionation can now be obtained with a high degree of selectivity with dry fractionation. As the crystallization operates in the bulk, viscosity problems limit the degree of crystallization in one single step, and multi‐step operations are currently used, giving rise to a wide range of fractions suitable for different applications. The secret is to combine proper crystal development with highly efficient separation by using membrane press filters allowing squeezing out the stearin cake for as much liquid occlusion (olein) as possible. The original booming of the dry fractionation process has helped mostly palm oil to conquer a strong position on the commodity market in one single stage; today, palm oil is without doubt the most widely fractionated oil. New demands for special cuts drifted the industry towards a more sophisticated approach: high‐iodine value super and top oleins, palm red fractions (high carotene and tocopherol/tocotrienol contents) or solvent‐free cocoa butter equivalents (palm mid fractions) are certainly what the future has in store.
Cross‐cultural assessment of eating disorders: psychometric properties of a Spanish version of the Bulimia Test‐Revised
Authors: Berrios‐Hernandez Mayra N. , Rodríguez‐Ruiz Sonia , Perez Marisol , Gleaves David H. , Maysonet Marielisa , Cepeda‐Benito Antonio
Published: April 2007

The purpose of this study was to examine the psychometric properties of a Spanish version of the Bulimia Test‐Revised (BULIT‐R). The goal was to test the factor‐structure equivalence of the BULIT‐R across two samples of college students from two different cultures, Spain and the US. Researchers using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) have reported different model solutions for the factor‐structure of the BULIT‐R: a one‐factor model, a four‐factor model, a five‐factor model and a six‐factor model. For the two samples, CFA did not support any of the models previously reported in the literature. EFA supported a six‐ and a four‐factor models for the US and Spanish samples, respectively. © 2007 John Wiley & Sons, Ltd and Eating Disorders Association.
Coarse bed load transport in an alluvial gravel bed stream, Dupuyer Creek, Montana
Authors: Whitaker Andrew C. , Potts Donald F.
Published: April 2007

Coarse bed load was sampled in a gravel/cobble bed stream during two major floods in the snowmelt runoff season. The channel is characterized by high rates of bank erosion and, therefore, high rates of sediment supply and bed load flux. Peak discharge reached four times bank‐full, and bed load was sampled at flows 0·7–1·7 times bank‐full. A large aperture bed load sampler (1 m by 0·45 m) captured the largest particles in motion, and specifically targeted the coarse bed load size distribution by using a relatively large mesh (32 mm or D25 of streambed surface size distribution). Bed load flux was highly variable, with a peak value of 0·85 kg/s/m for the coarse fraction above 38 mm. Bed load size distribution and maximum particle size was related to flow strength. Entrainment was size selective for particles D70 and larger (88–155 mm), while particles in the range D30–D70 (35–88 mm) ceased to move at essentially the same flow. Bed load flux was size selective in that coarse fractions of the streambed surface were under‐represented in or absent from the bed load. Painted tracer particles revealed that the streambed surface in the riffles could remain stable even during high rates of bed load transport. These observations suggest that a large proportion of bed load sediments was sourced from outside the riffles. Repeat surveys confirmed major scour and fill in pools (up to 0·75 m), and bank erosion (>2 m), which together contributed large volumes of sediment to the bed load. Copyright © 2007 John Wiley & Sons, Ltd.
Floodplain sedimentation rates in an alpine watershed determined by radionuclide techniques
Authors: Soster Frederick M. , Matisoff Gerald , Whiting Peter J. , Fornes William , Ketterer Michael , Szechenyi Scott
Published: April 2007

Vertical profiles of the activities of 137Cs and 210Pb were measured on floodplain sediment cores and upland soil cores along the Soda Butte Creek and the Yellowstone River to determine floodplain sedimentation rates. The position of mine tailings from a 1950 impoundment failure was used as a stratigraphic marker to estimate the sedimentation rates and to make comparisons with rates provided by radionuclide‐based methods. Mass accumulation (sedimentation) rates calculated from the position of the mine tailings ranged from 0·00 to 0·17 g cm−2 yr−1 and were in good agreement with sedimentation rates calculated from the inventories of 137Cs and 210Pb. Sedimentation rates calculated from the position of the 137Cs peak generally overestimated the sedimentation rates, probably because of increased downward migration of 137Cs caused by the low pH of water moving through the mine tailings or the high permeability of floodplain sediments relative to upland reference soils. This study demonstrates that the 137Cs and 210Pb inventory methods for determining sedimentation rates can be applied to an alpine floodplain where sedimentation events are episodic and where orographic effects on precipitation generate strong downstream gradients in the delivery of atmospheric radionuclides. Copyright © 2007 John Wiley & Sons, Ltd.
Turbo modulation and coding: design and evaluation of iterative bit‐interleaved coded modulation methods for wireless systems beyond 3G
Authors: Bauch Gerhard , Schreckenbach Frank , Hausl Christoph , Abe Tetsushi
Published: April 2007

We give an overview of iterative techniques for bit‐interleaved coded modulation. We start with simple methods where a convolutional code is concatenated with a standard QAM modulation scheme. The mapping is carefully chosen different from Gray mapping such that significant gains can be obtained by an iterative (turbo) receiver. The idea can also be applied to transmit antenna diversity as well as spatial multiplexing (MIMO). We then consider various powerful iterative coding schemes which are under discussion in standardisation for wireless systems beyond 3G such as serial or parallel concatenated convolutional codes, repeat accumulate codes and LDPC codes. We give a comparison in terms of complexity and performance.The main intention is to provide an illustrative overview over relevant applications of the turbo principle in demodulation and decoding. It is a summary of results which have been obtained in collaboration between the Institute of Communications Engineering, TUM and DoCoMo Euro‐Labs. Copyright © 2007 John Wiley & Sons, Ltd.
Flavour enhancement through the enzymatic hydrolysis of glycosidic aroma precursors in juices and wine beverages: a review
Authors: Pogorzelski Eugeniusz , Wilkowska Agnieszka
Published: April 2007

Aroma is one of the most important quality criteria of fruit and wine products. It is known, that aroma compounds are present in fruit in a free state and in the form of glycosides. In this review, the effect of glycosidases on flavour recovery from glycosides in fruit juice production and in winemaking was discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Semi‐distributed flood runoff model at the subcontinental scale for southwestern Iran
Authors: Nourani Vahid , Mano Akira
Published: April 2007

Rainfall–runoff modelling, as a surface hydrological process, on large‐scale data‐poor basins is currently a major topic of investigation that requires the model parameters be identified by using basin physical characteristics rather than calibration. This paper describes the application of the TOPMODEL framework accompanied by a kinematic wave model to the Karun River sub‐basins in southwestern Iran with just one conceptual parameter for calibration. ISLSCP1, HYDRO1K and Reynolds data sets are presented in a geographical information system and used as data sources for meteorological information, hydrological features and soil characteristics of the study area respectively. The results show that although the model developed can adequately predict flood runoff in the catchment with only one calibrated parameter, it is suggested that the effect of surface reservoirs be considered in the proposed model. Copyright © 2007 John Wiley & Sons, Ltd.
Long‐run trends in internal migrations in italy: a study in panel cointegration with dependent units
Authors: Fachin Stefano
Published: April 2007

The objective of this paper is to examine the long‐run determinants of internal migrations from southern Italy. In order to accomplish this task, the paper develops a bootstrap test for panel cointegration analysis with dependent units. Monte Carlo simulations show that the test, based on the Continuous‐Path Block bootstrap, has good power and size properties and is robust to both short‐ and long‐run dependence across units. The empirical analysis points to income in the sending region as a key factor of the decline of migrations, with unemployment and income differentials playing only a minor role. Copyright © 2007 John Wiley & Sons, Ltd.
Subsampling hypothesis tests for nonstationary panels with applications to exchange rates and stock prices
Authors: Choi In , Chue Timothy K.
Published: April 2007

This paper studies subsampling hypothesis tests for panel data that may be nonstationary, cross‐sectionally correlated, and cross‐sectionally cointegrated. The subsampling approach provides approximations to the finite sample distributions of the tests without estimating nuisance parameters. The tests include panel unit root and cointegration tests as special cases. The number of cross‐sectional units is assumed to be finite and that of time‐series observations infinite. It is shown that subsampling provides asymptotic distributions that are equivalent to the asymptotic distributions of the panel tests. In addition, the tests using critical values from subsampling are shown to be consistent. The subsampling methods are applied to panel unit root tests. The panel unit root tests considered are Levin, Lin, and Chu's (2002) t‐test; Im, Pesaran, and Shin's (2003) averaged t‐test; and Choi's (2001) inverse normal test. Simulation results regarding the subsampling panel unit root tests and some existing unit root tests for cross‐sectionally correlated panels are reported. In using the subsampling approach to examine the real exchange rates of the G7 countries and a group of 26 OECD countries, we find only mixed support for the purchasing power parity (PPP) hypothesis. We then examine a panel of 17 developed stock market indexes, and also find only mixed empirical support for them exhibiting relative mean reversion with respect to the US stock market index. Copyright © 2007 John Wiley & Sons, Ltd.
Financial audits: Taking an operational view
Authors: Reider Rob
Published: April 2007

It's not just accounting for the numbers. It's accounting for the functions and activities that produce the numbers. That's why simply doing a financial audit may not give you a clear picture of the company's operations. © 2007 Wiley Periodicals, Inc.
Digital analysis: A better way to detect fraud
Authors: Tackett James A.
Published: April 2007

The Sarbanes‐Oxley Act (SOX) has put corporate executives under the gun when it comes to detecting financial statement fraud. Unfortunately, most methods for discovering fraud are expensive and time‐consuming. But there is one fast, inexpensive method you may not be using: digital analysis. The author explains what it is and how to use it. © 2007 Wiley Periodicals, Inc.
Characterization of N‐palmitoylated human growth hormone by in situ liquid–liquid extraction and MALDI tandem mass spectrometry
Authors: Sachon Emmanuelle , Nielsen Per Franklin , Jensen Ole Nørregaard
Published: April 2007

Acylation is a common post‐translational modification found in secreted proteins and membrane‐associated proteins, including signal transducing and regulatory proteins. Acylation is also explored in the pharmaceutical and biotechnology industry to increase the stability and lifetime of protein‐based products. The presence of acyl moieties in proteins and peptides affects the physico‐chemical properties of these species, thereby modulating protein stability, function, localization and molecular interactions. Characterization of protein acylation is a challenging analytical task, which includes the precise definition of the acylation sites in proteins and determination of the identity and molecular heterogeneity of the acyl moiety at each individual site. In this study, we generated a chemically modified human growth hormone (hGH) by incorporation of a palmitoyl moiety on the Nε group of a lysine residue. Monoacylation of the hGH protein was confirmed by determination of the intact molecular weight by mass spectrometry. Detailed analysis of protein acylation was achieved by analysis of peptides derived from hGH by protease treatment. However, peptide mass mapping by MALDI MS using trypsin and AspN proteases and standard sample preparation methods did not reveal any palmitoylated peptides. In contrast, in situ liquid–liquid extraction (LLE) performed directly on the MALDI MS metal target enabled detection of acylated peptide candidates by MALDI MS and demonstrated that hGH was N‐palmitoylated at multiple lysine residues. MALDI MS and MS/MS analysis of the modified peptides mapped the N‐palmitoylation sites to Lys158, Lys172 and Lys140 or Lys145. This study demonstrates the utility of LLE/MALDI MS/MS for mapping and characterization of acylation sites in proteins and peptides and the importance of optimizing sample preparation methods for mass spectrometry‐based determination of substoichiometric, multi‐site protein modifications. Copyright © 2007 John Wiley & Sons, Ltd.
Bacterial exopolysaccharides – a perception
Authors: Suresh Kumar Anita , Mody Kalpana , Jha Bhavanath
Published: April 2007

Microbial polysaccharides are multifunctional and can be divided into intracellular polysaccharides, structural polysaccharides and extracellular polysaccharides or exopolysaccharides (EPS). Extracellular polymeric substances (EPS), produced by both prokaryotes (eubacteria and archaebacteria) and eukaryotes (phytoplankton, fungi, and algae), have been of topical research interest. Newer approaches are carried out today to replace the traditionally used plant gums by their bacterial counterparts. The bacterial exopolysaccharides represent a wide range of chemical structures, but have not yet acquired appreciable significance. Chemically, EPS are rich in high molecular weight polysaccharides (10 to 30 kDa) and have heteropolymeric composition. They have new‐fangled applications due to the unique properties they possess. Owing to this, exopolysaccharides have found multifarious applications in the food, pharmaceutical and other industries. Hence, the present article converges on bacterial exopolysaccharides. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
New phenyl‐ethanediols from the culture broth of Boletus edulis
Authors: Yang Wan‐Qiu , Qin Xiang‐Dong , Shao Hong‐Jun , Fang Li‐Zhen , Wang Fei , Ding Zhi‐Hui , Dong Ze‐Jun , Liu Ji‐Kai
Published: April 2007

A new phenyl‐ethanediol, (1S)‐(4‐acetylphenyl)‐1, 2‐ethanediol (1), and a new natural product, (1S)‐(3‐ethenylphenyl)‐1, 2‐ethanediol (2), were isolated from the culture broth of the basidiomycete Boletus edulis together with three related known compounds, 1‐(4‐ethylphenyl)‐1, 2‐ethanediol (3), 1‐(3‐ethylphenyl)‐1, 2‐ethanediol (4) and 1‐(3‐formylphenyl)‐ethanone (5). Their structures were elucidated by spectroscopic methods including extensive 2D‐NMR techniques. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fast determination of Z‐ligustilide in plasma by gas chromatography/mass spectrometry following headspace single‐drop microextraction
Authors: Dong Ling , Deng Chunhui , Wang Ben , Shen Xizhong
Published: April 2007

Angelica sinensis (danggui in Chinese) is a common traditional Chinese medicine (TCM), and its essential oil has been used for the treatment of many diseases such as hepatic fibrosis. Z‐Ligustilide has been found to be an important active component in the TCM essential oil. In this work, for the first time, headspace single‐drop microextraction (HS‐SDME) followed by gas chromatography‐mass spectrometry (GC‐MS) was developed for the determination of Z‐ligustilide in rabbit plasma after oral administration of essential oil of danggui. The extraction parameters of solvent selection, solvent volume, sample temperature, extraction time, stirring rate, and ion strength were systemically optimized. Furthermore, the method linearity, detection limit, and precision were also investigated. It was shown that the proposed method provided good linearity (0.02–20 μg/mL, R2 = 0.997), low detection limit (10 ng/mL), and good precision (RSD value less than 9%). Finally, HS‐SDME followed by GC/MS was used for fast determination of Z‐ligustilide in rabbit plasma at different time intervals after oral administration of danggui essential oil. The experimental results suggest that HS‐SDME followed by GC/MS is a simple, sensitive, and low‐cost method for the determination of Z‐ligustilide in plasma, and a low‐cost approach to pharmacokinetics studies of active components in TCMs.
The role of UHPLC in pharmaceutical development
Authors: Chesnut Stephen M. , Salisbury John J.
Published: April 2007

Pharmaceutical separations can be divided into three categories: high throughput, high productivity, and high resolution. These categories contain specific pharmaceutical applications, each of which has distinct separation goals. Traditionally, these goals have been achieved utilizing conventional HPLC with typical column dimensions and particle sizes. The recent introduction of ultra‐HPLC (UHPLC) has provided a new potential for method development and analysis. Pharmaceutical chemists must determine the impact of this emerging technology. UHPLC is achieved by using sub‐2 μm particle size column packing at increased linear velocities. In order to utilize this technology, mobile phase viscosity must be minimized or the chromatography system must be redesigned to withstand an increased backpressure. Today, there are many commercially available UHPLC systems capable of exceeding conventional pressure limits of 400 bar. The advantage of UHPLC over conventional HPLC is the capability to increase the speed without sacrificing efficiency. In comparison to traditional HPLC, our research showed that UHPLC can decrease run times up to 7×. In addition, for high resolution applications, UHPLC achieved significant efficiency advantages over traditional HPLC. This paper will evaluate the potential roles for utilizing UHPLC in the pharmaceutical industry.
Temperature stability of reversed phase and normal phase stationary phases under aqueous conditions
Authors: Teutenberg Thorsten , Tuerk Jochen , Holzhauser Maren , Giegold Sascha
Published: April 2007

In this study the temperature stability of several normal phase and RP columns was investigated using a water‐only mobile phase. The temperature was adjusted to 120°C for the bare silica stationary phases and to 185°C for the metal oxide and carbon stationary phases. It could be shown that metal oxide stationary phases exhibited excellent thermal stability over the duration of the test period and are therefore suitable for high temperature LC applications.
High temperature to increase throughput in liquid chromatography and liquid chromatography–mass spectrometry with a porous graphitic carbon stationary phase
Authors: Pereira Luisa , Aspey Stephen , Ritchie Harald
Published: April 2007

High separation temperatures in liquid chromatography and liquid chromatography–mass spectrometry with a porous graphitic carbon column were investigated. Separation temperature was varied up to 200°C, and the effect on retention, analysis time, and sensitivity was measured. Analysis times were reduced more than six‐fold, whilst baseline resolution was maintained. The impact of the separation temperature on signal‐to‐noise ratio with atmospheric pressure chemical ionisation or electrospray mass spectrometric detection was also investigated. The potential of using superheated water for the analysis of some very polar compounds is illustrated. Monitoring of column stability detected no loss of performance, due to the highly stable nature of the 100% carbon stationary phase.
Anwendung brillanter Diodenlaser beim Schweißen von Aluminium‐Dünnblechen
Authors: Kaierle Stefan , Regaard Boris , Dahmen Martin , Fiedler Wolfgang
Published: April 2007

Fasergekoppelte Diodenlaser mit optischen Ausgangsleistungen im Multi‐Kilowattbereich konkurrieren zunehmend mit Festkörperlasern als direkte Strahlquelle für die Materialbearbeitung. Vorteile gegenüber konventionellen Strahlquellen sind eine wesentlich kompaktere Bauweise, ein hoher Wirkungsgrad und eine große Zuverlässigkeit bei gleichzeitig geringerem Wartungs‐ und Betriebsaufwand.
Das Strahlprofil von Hochleistungslasern – Genaue Messungen als Basis für die Lasercharakterisierung
Authors: Schwede Harald
Published: April 2007

Für die Reproduzierbarkeit jeder Laseranwendung ist eine umfassende Kenntnis der Laserstrahlparameter unabdingbar. Dazu gehören Strahlleistung, Strahldurchmesser, Strahllage, Polarisation etc. Die einfache und dennoch korrekte Erfassung dieser Parameter ist seit langem ein Diskussionsthema. Bei Hochleistungslasern ist sie besonders schwierig, aber auch besonders wichtig.
Von Mikro bis Makro: Rofin‐Sinar baut Laser für die ganze Welt – CEO Günther Braun im Interview
Authors: Braun Günther
Published: April 2007

Rofin‐Sinar war eine der ersten deutschen Laserfirmen, die den Schritt an die Börse gewagt haben. Der Erfolg hat ihnen recht gegeben. Das Unternehmen konnte sowohl den Umsatz als auch den Börsenkurs vervielfachen. Andreas Thoß sprach für das Laser Technik Journal mit dem CEO von RSTI Günther Braun.
Ethylene/10‐Undecenoic Acid Copolymers Prepared with Different Metallocene Catalysts
Authors: Cerrada María L. , Benavente Rosario , Pérez Ernesto , Moniz‐Santos Jorge , Campos João M. , Ribeiro M. Rosário
Published: April 2007

The synthesis and characterisation of several functionalised polyethylenes, obtained by direct copolymerisation of ethylene with 10‐undecenoic acid (UA), have been carried out. Two metallocene complexes of Cs symmetry with different bridges were used: a dimethylsilyl bridge complex Me2Si(Cp)(Flu)ZrCl2 and a phenylidene bridge complex Ph2C(Cp)(Flu)ZrCl2. For comparison, results obtained with the Cp2ZrCl2/MAO system are also reported. The copolymerisation activity depends strongly on the metallocene complex and on the added amount of the UA comonomer. High incorporation levels of up to 7.3 mol‐% are achieved when using the phenylidene bridged catalyst presenting a rigid structure and a wide bite angle. The effect of comonomer content and catalyst geometry on the crystalline structure and mechanical behaviour of the different copolymers are comprehensively discussed.

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All‐in‐one Layer: Anisotropic Emission due to Light‐Induced Orientation of a Multifunctional Polymer
Authors: Rosenhauer Regina , Stumpe Joachim , Giménez Raquel , Piñol Milagros , Serrano José Luis , Viñuales Ana
Published: April 2007

An efficient procedure to create oriented polymer films with strongly anisotropic properties is described. It is based on a two‐step process combining a photochemical and a thermal aligning step. The orientation of the polymer parallel or perpendicular to linearly polarised incident light can be adjusted. The method presented allows for simple fabrication of films with anisotropic absorption and emission characteristics with a dichroism of 0.7 and a fluorescence anisotropy of about 8.

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Multifunctional Thermally Reversible Nanostructured Thermosetting Materials Based on Block Copolymers Dispersed Liquid Crystal
Authors: Tercjak Agnieszka , Serrano Elena , Mondragon Iñaki
Published: April 2007

Thermally reversible nanostructured thermosetting materials are prepared for the first time by modification of an epoxy resin with 5 wt.‐% of an amphiphilic polystyrene‐block‐poly(ethylene oxide) block copolymer (PSEO) and 30 wt.‐% of a low‐molecular‐weight liquid crystal, 4′‐(hexyl)‐4‐biphenylcarbonitrile (HBC). The epoxy system modified with 5 wt.‐% PSEO amphiphilic copolymer self‐assembles into spherical microdomains with a size distribution between 32 and 45 nm in diameter. Under the same conditions, the modification of an epoxy system with 5 wt.‐% PSEO and 30 wt.‐% HBC leads to a micro‐phase separated PS‐rich domains embedded in a HBC phase. The morphology of this nanostructured thermosetting system consists in a higher amount of spherical microdomains of PSEO/HBC with the size distribution between 40 and 75 nm in diameter. This implies that the separation of the PS‐rich phase provokes the separation of the liquid crystal and allows one to obtain a novel thermally switchable smart material.

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Novel Wormlike Nanostructures Self‐Assembled in a Well Defined Liquid Crystalline Diblock Copolymer with Azobenzene Moieties
Authors: Yu Haifeng , Shishido Atsushi , Iyoda Tomokazu , Ikeda Tomiki
Published: April 2007

Novel wormlike nanostructures were self‐assembled in bulk films of a well defined diblock copolymer with azobenzene moieties, which was prepared by atom transfer radical polymerization (ATRP). For comparison, a homopolymer with almost the same repeat units of azobenzene as those in the copolymer was also prepared. They both had well defined structures and exhibited a smectic liquid crystalline phase. Upon annealing the copolymer films, poly(methyl methacrylate) formed a matrix with excellent optical properties, and the azobenzene segment in the minority phase self‐assembled into a wormlike mesogenic domain in the bulk films. Such block copolymer films exhibited stability and transparency by eliminating the scattering of visible light, indicating their potential application as photoresponsive functional materials. Although wormlike morphologies have been obtained in micelles from block copolymer solutions, to the best of our knowledge, such wormlike nanostructures have never been explored in bulk films.

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Influence of the Position of the Connecting Spacer of the Chromophore on the Nonlinear Optical Response
Authors: Briers David , De Cremer Lieven , Koeckelberghs Guy , Foerier Stijn , Verbiest Thierry , Samyn Celest
Published: April 2007

A new chromophore, C1, based on a similar DπA‐structure as in the FTC‐chromophore but with a hydroxyalkyl spacer perpendicular to the direction of the dipole moment was synthesized. Both chromophores and the CLD‐chromophore were used to prepare high Tg nonlinear optical vinyl polymers. The influence of the position of the spacer on the DπA‐system on the NLO response of the resulting polymers was investigated.

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Vanadocene(IV) dicyanide complexes: the evidence super‐hyperfine coupling for compounds with 13CN ligands
Authors: Honzíček Jan , Vinklárek Jaromír , Černošek Zdeněk , Císařová Ivana
Published: April 2007

An EPR study of the vanadocene complexes (C5H5)2V(CN)2 and (CH3C5H4)2V(CN)2 was carried out. Such compounds show strong super‐hyperfine coupling (|aiso(13C)|∼1.27 mT) when 13C labeled cyanide is used for their preparation. Super‐hyperfine splitting was observed in the isotropic spectra of solution samples as well as in the anisotropic spectra of frozen solutions. Such studies were supplemented with structural characterization of the parent compounds. Molecular structure of the complex (CH3C5H4)2V(CN)2 was determined by single‐crystal X‐ray diffraction analysis. Both compounds were characterized by infrared and Raman spectroscopy. Copyright © 2007 John Wiley & Sons, Ltd.
Molecular mass estimation of derivatized compounds: a PFG NMR study
Authors: Crutchfield Christopher A. , Harris Douglas J.
Published: April 2007

Pulsed‐field gradient (PFG) 1H and 31P NMR methods were developed to quantitatively estimate the molecular mass of compounds, derivatized with either trichloroacetyl isocyanate (TAI) or 2‐chloro‐4,4,5,5‐tetramethyl‐1,3,2‐dioxaphospholane (chlorophospholane). These agents provide selective analysis with high sensitivity for molecules containing alcohol, amine, carboxylic acid, or thiol functional groups. Tetramethylsilane (TMS) or bisphenol A was used as internal diffusion reference. The empirical relationship between relative diffusivity and molecular mass was established for a set of mono‐ and difunctional compounds with molecular masses in the range 32–330 g/mol. The utility of the method was demonstrated by analyzing alcohol, phenol, and carboxylic acid components in lubricating oil. Copyright © 2007 John Wiley & Sons, Ltd.
Dynamics and conformations of PEO chains chemically bonded on silica: comparison between 1H and 2H NMR
Authors: Tajouri T. , Hommel H.
Published: April 2007

1H NMR was used to study the motion of monomer units in a layer of poly(ethylene oxide) chains grafted on silica. First, the dependence of the relaxation times on the grafting ratios is discussed qualitatively from a phenomenological point of view. Next, the NMR line narrowing effect by high‐speed rotation is observed in the same samples with different grafting ratios. The magic angle spinning technique permits determination of two correlation times for each grafting ratio: τc characteristic of an environment with a fast motion and τl characteristic of an environment with a slow motion. In addition, the dynamics of these grafted chains are investigated by deuterium NMR (2H NMR), which is sensitive to the anisotropy of molecular motion. The evolution has been studied for two extreme grafting ratios and each time as a function of temperature. The anisotropy is more marked at low temperatures and for a low grafting ratio. The results are consistent with the 1H NMR relaxation times measured as a function of temperature. Copyright © 2007 John Wiley & Sons, Ltd.
In vitro development and cell allocation of porcine blastocysts derived by aggregation of in vitro fertilized embryos
Authors: Lee Sang‐Goo , Park Chi‐Hun , Choi Don‐Ho , Kim Hye‐Sun , Ka Hak‐Hyun , Lee Chang‐Kyu
Published: April 2007

In pigs, the morphology and cell number of in vitro‐produced blastocysts are inferior to those of their in vivo counterparts. The objective of this study was to increase developmental competence and to gain an understanding of cell allocation in blastocysts derived from the aggregation of four‐cell stage porcine embryos produced in vitro. After removal of the zona pellucida, two (2×) and three (3×) four‐cell stage embryos were aggregated by co‐culturing them in aggregation plates. Five days after aggregation, the developmental ability and the number of cells in the aggregated embryos were determined. The percentage of blastocysts was higher (P < 0.05) in both the 2× and 3× aggregated embryos (66.6% and 72.0%, respectively) compared to that of the 1× embryos and the intact controls (43.1% and 36.4%, respectively). The total cell number of blastocysts also increased in aggregated embryos compared to that of intact controls (2.6‐fold for 2× and 3.4‐fold for 3×) (P < 0.05). The cells of two differentially stained embryos were started to mix at 72 hr after aggregation. In vitro‐fertilized porcine aggregates (2×) were developed to blastocyst with a random distribution of cells from each embryo. The mRNA levels for the oct‐4, bcl‐xL and connexin 43 genes were higher (P < 0.05) and bak gene were lower (P < 0.05) in both the 2× and 3× aggregated embryos than the intact controls. Therefore, the aggregation of the four‐cell stage embryos could be used to improve the quality of porcine preimplantation stage embryos produced in vitro. Mol. Reprod. Dev. 74: 1436–1445, 2007. © 2007 Wiley‐Liss, Inc.
Biaxial test simulations using a packing of polygonal particles
Authors: Peña A. A. , Lizcano A. , Alonso‐Marroquin F. , Herrmann H. J.
Published: April 2007

The mechanical response of cohesionless granular materials under monotonic loading is studied by performing molecular dynamic simulations. The diversity of shapes of soil grains is modelled by using randomly generated convex polygons as granular particles. Results of the biaxial test obtained for dense and loose media show that samples achieve the same void
ratio at large strains independent of their initial density state. This limit state resembles the so‐called critical state of soil mechanics, except for some stress fluctuations, which remain for large deformations. These fluctuations are studied at the micro‐mechanical level, by following the evolution of the co‐ordination number, force chains and the fraction of the sliding contacts of the sample. Copyright © 2007 John Wiley & Sons, Ltd.
CAD inspired hierarchical partition of unity constructions for NURBS‐based, meshless design, analysis and optimization
Authors: Rayasam M. , Srinivasan V. , Subbarayan G.
Published: April 2007

In this paper we develop a unified representational paradigm for design and analysis that is inspired by the set theoretic Boolean operations of the constructive solid geometry (CSG) procedure of computer‐aided design (CAD). We develop the notion of a primitive design state (corresponding to a CSG primitive region), which is characterized by a description of the geometrical shape of the primitive and by a description of the material distribution within the primitive. We analogously define a primitive behaviour state that is associated with a primitive design state and that is determined through a global analysis problem. We define a global multi‐level design problem to determine the primitive design states. We define Boolean operations on the fields belonging to primitive design and behaviour spaces and show that the compositions of these fields amount to a hierarchical partition of unity construction. We propose to use non‐uniform rational B‐splines (NURBS) to discretize the geometry, material, and behavioural fields (local approximations) defined on the primitive regions. We show that this leads to recursive partition of unity constructions on the knot spaces (sub‐local approximations) due to the partition of unity property of NURBS basis functions. Since the primitive shapes are parametrically defined using NURBS, the numerical quadrature is carried out on the parametric sub‐regions of the NURBS entities. This eliminates the need for either a background mesh or a pseudo‐mesh for quadrature. The developed methodology is implemented in a symbolic, meshless computational framework written using the java language (jNURBS) and was demonstrated on two classes of problems. The first class is the simultaneous optimal design of shape and multi‐material distributions. The procedure is argued as being a generalization of classical topology optimization to designing objects made of functionally graded materials with pre‐defined geometrical constraints, such as holes or fixed boundary shape. The second class of problems demonstrated in the paper is optimal design to mitigate the effects of cracks. Here, we identify the optimal locations of holes introduced to reduce the stress intensity factor of an edge crack. Copyright © 2007 John Wiley & Sons, Ltd.
Investigation of heat transfer coefficient in two‐dimensional transient inverse heat conduction problems using the hybrid inverse scheme
Authors: Chen Han‐Taw , Wu Xin‐Yi
Published: April 2007

A hybrid scheme of the Laplace transform, finite difference and least‐squares methods in conjunction with a sequential‐in‐time concept, cubic spline and temperature measurements is applied to predict the heat transfer coefficient distribution on a boundary surface in two‐dimensional transient inverse heat conduction problems. In this study, the functional form of the heat transfer coefficient is unknown a priori. The whole spatial domain of the unknown heat transfer coefficient is divided into several analysis sub‐intervals. Later, a series of connected cubic polynomial function in space and a linear function in time can be applied to estimate the unknown surface conditions. Due to the application of the Laplace transform, the unknown heat transfer coefficient can be estimated from a specific time. In order to evidence the accuracy of the present inverse scheme, comparisons among the present estimates, previous results and exact solution are made. The results show that the present inverse scheme not only can reduce the number of the measurement locations but also can increase the accuracy of the estimated results. Good estimation on the heat transfer coefficient can be obtained from the knowledge of the transient temperature recordings even in the case with measurement errors. Copyright © 2007 John Wiley & Sons, Ltd.
The association of knowledge and perception of medications with compliance and health states among hypertension patients: A prospective study
Authors: Given Charles W. , Given Barbara A. , Simoni Lewis E.
Published: April 2007

The purposes of this prospective study were () to describe the associations among patients' knowledge of medications and perceptions of side effects and benefits of medications, () to clarify the independent effects of knowledge and perceptions of side effects upon patients' reports of compliance with medications, and (c) to describe the relationship between compliance and patients' health states as measured by a reduction in diastolic blood pressure. Eighty‐eight diagnosed hypertensive patients were interviewed at the onset of a medication regimen and at the end of 5 months. Audits of medical records were completed for the entire 5‐month period. The results indicated that both knowledge and perceptions of benefits from medications were significantly correlated with patient compliance at the beginning and at the end observations. The partial correlations, however, indicated that knowledge of medications had a greater independent association with compliance at the beginning of the study and that perceptions of benefits from medications had a greater independent association with compliance at the end observation period. Finally, patients who, on the average, complied with their medications more than two‐thirds of the time experienced a clinically significant reduction in their diastolic blood pressure. The results of the study suggest that knowledge may serve to stimulate compliance at the beginning of a treatment regimen, whereas perceptions are more effective stimulants once therapy has begun. These findings are discussed in view of the literature on patient knowledge and their implications for primary care providers.
Contributions of the passionate statistician
Authors: Grier Brown , Grier Margaret
Published: April 2007

Information available about the mathematical and statistical training of Florence Nightingale is presented. The state of development of statistics at the beginning of her research activity is summarized in terms of the techniques available at that time and in terms of the modern statistical tools that had not been invented. A few of her specific contributions to statistical methodology are noted. A series of questions is given in the hope of stimulating further inquiry into Nightingale's quantitive methods and research contributions.
Correlates of success in the baccalaureate education of registered nurses
Authors: Rezler Agnes G. , Moore Janet S.
Published: April 2007

The major purpose of this investigation was to identify correlates of success in a baccalaureate completion program to aid in the selection of registered nurses. The sample included 170 graduates from one baccalaureate program. Their ages ranged from 20 to 51; 79% graduated from a diploma program and 21% from a community college associate degree (AD) program. The predictors of achievement were () age, () diploma versus associate degree background, (c) work experience, (d) six validation examination scores, and (e) two entry grade point averages (GPAs) based on liberal arts and nursing subjects. respectively. The criteria of success were two exit GPAs from the baccalaureate program, based on liberal arts and nursing subjects. Comparison of mean scores and multiple regression analyses were used to relate predictors and criteria. The major conclusions are that () entry liberal arts GPA is the best predictor of achievement in this baccalaureate program, irrespective of how long ago it was obtained; () diploma school graduates perform better than junior college graduates in the classroom as well as in clinical practice; and (c) age is NOT a factor in performance in a baccalaureate completion program.