bluuebunny/crossref_metadata_2025 huggingface dataset:
High‐fidelity fractionation of ssDNA fragments differing in size by one‐base on a spiral‐channel electrophoretic chip
Authors: Sun Kai , Suzuki Nobuko , Li Zheyu , Araki Ryoko , Ueno Kosei , Juodkazis Saulius , Abe Masumi , Noji Sumihare , Misawa Hiroaki
Published: December 2009

For the fractionation of fragments of interest from selective PCR products generated by high coverage gene expression profiling (HiCEP) analysis, high‐resolution with the ability to discriminate and fractionate fragments differing by one base (base pair) in size is highly required. We report here on a new 4‐inch diameter spiral‐channel chip device for automatic high‐fidelity fractionation. Overlapping DNA fragments of 180, 181 and 182 bases, with only one‐base difference in size, were successfully fractionated. The collected fragments were PCR amplified, and then evaluated by size checking analysis, DNA sequencing, and homolog search. The high‐resolution fractionation has been achieved because of the combined contributions of (i) the high‐resolution separation using a 30 cm long spiral channel, (ii) a blocking technique to avoid contamination from unselected fragments during CE, and (iii) precise micro‐scale target extraction. Contaminations due to unselected fractions have been greatly decreased to a negligible level by optimization of the extraction position and extraction time corresponding to the targeted segment only. This technique can be adapted to a wide range of applications, such as protein or cell collections where requirements for the high purity are more important than the amount of recovered fractionated material.
Recent innovations in protein separation on microchips by electrophoretic methods: An update
Authors: Tran Nguyet Thuy , Ayed Ichraf , Pallandre Antoine , Taverna Myriam
Published: December 2009

Lab‐on‐a‐chip electrophoresis is becoming increasingly useful for protein analysis, thanks to recent developments in this field. This review is an update of the review we published at the start of 2008 [Peng, Y., Pallandre, A., Tran, N. T., Taverna, M., Electrophoresis 2008, 29, 156–177]. The superiority of polymers for the manufacture of analytical microchips has been confirmed. This trend implies several modifications to the processes previously used with glass/silicon chips and requires a better understanding of the interfacial phenomena of these materials. Significant progress in chip‐based techniques for protein analysis has been made in the last 2 years. In addition to advances in traditional electrokinetic modes, counter‐flow gradient focusing techniques have emerged as useful methods not only for separation, but also for the online preconcentration of samples. This review, with more than 175 references, presents recent advances and novel strategies for EOF measurement, surface treatment, sample pretreatment, detection and innovations relating to the different modes of separation.
Fabrication of PMMA microfluidic chips using disposable agar hydrogel templates
Authors: Yao Xiao , Chen Zhi , Chen Gang
Published: December 2009

A novel method based on disposable agar hydrogel temples have been developed for the fabrication of PMMA microfluidic chips. Molten agar hydrogel was sandwiched between a glass plate and a PMMA template bearing negative relief of microstructure. After cooling, the negative PMMA template could be easily separated from the solidified agar hydrogel and a layer of agar hydrogel temple bearing high‐fidelity positive relief of the microstructure was left on the glass plate. Prepolymerized methyl methacrylate molding solution containing ultraviolet‐initiator was subsequently sandwiched between the agar hydrogel template and a PMMA plate and was allowed to polymerize under ultraviolet light to fabricate the PMMA channel plate at room temperature. Complete microchips could be obtained by bonding the channel plates with covers. The prepared microfluidic microchips have been successfully employed in the electrophoresis separation and detection of several ions in connection with contactless conductivity detection.
Response simulation and seismic assessment of highway overcrossings
Authors: Kotsoglou Anastasios , Pantazopoulou Stavroula
Published: December 2009

Interaction of bridge structures with the adjacent embankment fills and pile foundations is generally responsible for response modification of the system to strong ground excitations, to a degree that depends on soil compliance, support conditions, and soil mass mobilized in dynamic response. This paper presents a general modeling and assessment procedure specifically targeted for simulation of the dynamic response of short bridges such as highway overcrossings, where the embankment soil–structure interaction is the most prevalent. From previous studies it has been shown that in this type of interaction, seismic displacement demands are magnified in the critical bridge components such as the central piers. This issue is of particular relevance not only in new design but also in the assessment of the existing infrastructure. Among a wide range of issues relevant to soil–structure interaction, typical highway overcrossings that have flexible abutments supported on earth embankments were investigated extensively in the paper. Simulation procedures are proposed for consideration of bridge‐embankment interaction effects in practical analysis of these structures for estimation of their seismic performance. Results are extrapolated after extensive parametric studies and are used to extract ready‐to‐use, general, and parameterized capacity curves for a wide range of possible material properties and geometric characteristics of the bridge‐embankment assembly. Using two instrumented highway overpasses as benchmark examples, the capacity curves estimated using the proposed practical procedures are correlated successfully with the results of explicit incremental dynamic analysis, verifying the applicability of the simple tools developed herein, in seismic assessment of existing short bridges. Copyright © 2009 John Wiley & Sons, Ltd.
Focal 9p instability in hematologic neoplasias revealed by comparative genomic hybridization and single‐nucleotide polymorphism microarray analyses
Authors: Usvasalo Anu , Ninomiya Shinsuke , Räty Riikka , Hollmén Jaakko , Saarinen‐Pihkala Ulla M. , Elonen Erkki , Knuutila Sakari
Published: December 2009

Copy number losses in chromosome arm 9p are well‐known aberrations in malignancies, including leukemias. The CDKN2A gene is suggested to play a key role in these aberrations. In this study overviewing 9p losses in hematologic neoplasias, we introduce the term focal 9p instability to indicate multiple areas of copy number loss or homozygous loss within a larger heterozygous one in 9p. We have used microarray comparative genomic hybridization to study patients with acute lymphoblastic leukemia (ALL, n = 140), acute myeloid leukemia (n = 50), chronic lymphocytic leukemia (n = 20), and myelodysplastic syndromes (n = 37). Our results show that 9p instability is restricted to ALL. In total, 58/140 (41%) patients with ALL had a loss in 9p. The 9p instability was detected in 19% of the patients with ALL and always included homozygous loss of CDKN2A along with loss of CDKN2B. Other possibly important genes included MTAP, IFN, MLLT3, JAK2, PTPLAD2, and PAX5. 13/27 (48%) patients with the instability had the BCR/ABL1 fusion gene or other oncogene‐activating translocation or structural aberrations. Two patients had homozygous loss of hsa‐mir −31, a microRNA known to regulate IKZF1. IKZF1 deletion at 7p12.1 was seen in 10 (37%) patients with the 9p instability. These findings suggest that, in ALL leukemogenesis, loss of CDKN2A and other target genes in the instability region is frequently associated with BCR/ABL1 and IKZF1 dysfunction. The multiple mechanisms leading to 9p instability including physical or epigenetic loss of the target genes, loss of the microRNA cluster, and the role of FRA9G fragile site are discussed. © 2009 Wiley‐Liss, Inc.
Gene, region and pathway level analyses in whole‐genome studies
Authors: De la Cruz Omar , Wen Xiaoquan , Ke Baoguan , Song Minsun , Nicolae Dan L.
Published: December 2009

In the setting of genome‐wide association studies, we propose a method for assigning a measure of significance to pre‐defined sets of markers in the genome. The sets can be genes, conserved regions, or groups of genes such as pathways. Using the proposed methods and algorithms, evidence for association between a particular functional unit and a disease status can be obtained not just by the presence of a strong signal from a SNP within it, but also by the combination of several simultaneous weaker signals that are not strongly correlated. This approach has several advantages. First, moderately strong signals from different SNPs are combined to obtain a much stronger signal for the set, therefore increasing power. Second, in combination with methods that provide information on untyped markers, it leads to results that can be readily combined across studies and platforms that might use different SNPs. Third, the results are easy to interpret, since they refer to functional sets of markers that are likely to behave as a unit in their phenotypic effect. Finally, the availability of gene‐level P‐values for association is the first step in developing methods that integrate information from pathways and networks with genome‐wide association data, and these can lead to a better understanding of the complex traits genetic architecture. The power of the approach is investigated in simulated and real datasets. Novel Crohn's disease associations are found using the WTCCC data. Genet. Epidemiol. 34: 222–231, 2010. © 2009 Wiley‐Liss, Inc.
Aspects of observing and claiming allele flips in association studies
Authors: Clarke Geraldine M. , Cardon Lon R.
Published: December 2009

Significant allele flipping, where associations for the same disease occur at opposite alleles of the same bi‐allelic locus, is increasing. But when is a significant allele flip genuine? We address the statistical issues of claiming and observing genuine allele flips in actual samples. We show that unless an allele flip is genuine, the probability of observing a significant allele flip in samples ascertained similarly from a common population is negligible. We derive expressions for the expected values of commonly used measures of association, which confirm previous findings that the underlying mechanism of a genuine allele flip is variation in the haplotype frequencies and show further how this variation interacts with variation in the genetic effects to impact allele flipping. We show that for association testing at proxy SNPs, common in genome‐wide association studies, variation in haplotype frequencies must coincide with a reversal in the sign of linkage disequilibrium (LD) to trigger genuine allele flips. Using HapMap data and r, rather than r2, to highlight previously unobserved effects, we show that unless genetic effects are large, variation in LD is unlikely to cause genuine allele flips in samples drawn from the same population. However, as populations diverge, it is an increasingly viable cause of a genuine allele flip for sufficiently large genetic effect and/or sample sizes. We conclude that evidence of variation in local patterns of LD, ancestral composition of study samples, and environmental exposures between study populations can provide compelling practical evidence in defense of a genuine allele flip. Genet. Epidemiol. 34: 266–274, 2010. © 2009 Wiley‐Liss, Inc.
Institutional brand personality and advertisements during televised games
Authors: Harris Michael S.
Published: December 2009

Brands underscore what is distinctive and notable about institutions, important in the minds of consumers interested in purchasing something more than just a generic product.
Students as spectators: Their academic and social integration
Authors: Clopton Aaron
Published: December 2009

Enhanced academic success and social integration may be a product for students who are sports fans.
Organizational complexity: The athletics department and the university
Authors: Buer Troy
Published: December 2009

Institutions can manage the conflicts inherent in their academic and athletic identities through seeking synergies.
Inter‐organizational collaboration projects in the public sector: a balance between integration and demarcation
Authors: Löfström Mikael
Published: December 2009

For several years, the development of the Swedish public sector has been accompanied by a discussion about inter‐organizational collaboration, which has been examined in several national experiments. The experience, however, indicates significant difficulties in implementing collaboration in local authorities' regular activities. This article argues that organizing inter‐organizational collaboration in projects tends to be counterproductive, since the purpose of this collaboration is to increase the integration of local authorities. This article is based on case studies of three different collaboration projects. Each project is analyzed in relation to the way collaboration is organized within the project and how the relationship to the local authorities' activities is designed. The outcome of these studies shows that while collaboration projects increase integration between the responsible authorities, the integration stays within the projects. This is due to the fact that the projects were designed as units separate from the responsible authorities. As a result, the collaboration that occurs in the projects is not implemented in the local authorities' activities, and the viability of the increased integration of different responsible authorities does not extend beyond the projects. Copyright © 2009 John Wiley & Sons, Ltd.
Prenatal ultrasound and magnetic resonance imaging depiction of a small sublingual ranula
Authors: Tamaru Shunsuke , Kikuchi Akihiko , Ono Kyoko , Kita Mariko , Horikoshi Tsuguhiro , Takagi Kimiyo
Published: December 2009

Prenatal diagnosis of a congenital ranula has rarely been reported. We describe the case of a small ranula depicted on prenatal sonogram and magnetic resonance imaging, in which we could confirm the intact airway. Although the size of the ranula noted in our fetus was the smallest among the cases reported in the English literature, both of these imaging modalities clearly presented typical diagnostic features present on both ultrasound and magnetic resonance imaging. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2010
Inpatient glucose control: a glycemic survey of 126 U.S. hospitals
Authors: Cook Curtiss B. , Kongable Gail L. , Potter Daniel Jason , Abad Victor J. , Leija Dora E. , Anderson Marcy
Published: December 2009

BACKGROUND:

Despite increased awareness of the value of treating inpatient hyperglycemia, little is known about glucose control in U.S. hospitals.

METHODS:

The Remote Automated Laboratory System‐Plus (RALS®‐Plus Medical Automation Systems, Charlottesville, VA) was used to extract inpatient point‐of‐care bedside glucose (POC‐BG) tests from 126 hospitals for the period January to December 2007. Patient‐day‐weighted mean POC‐BG and hypoglycemia/hyperglycemia rates were calculated for intensive care unit (ICU) and non‐ICU areas. The relationship of POC‐BG levels with hospital characteristics was determined.

RESULTS:

A total of 12,559,305 POC‐BG measurements were analyzed: 2,935,167 from the ICU and 9,624,138 from the non‐ICU. Patient‐day‐weighted mean POC‐BG was 165 mg/dL for ICU and 166 mg/dL for non‐ICU. Hospital hyperglycemia (>180 mg/dL) prevalence was 46.0% for ICU and 31.7% for non‐ICU. Hospital hypoglycemia (<70 mg/dL) prevalence was low at 10.1% for ICU and 3.5% for non‐ICU. For ICU and non‐ICU there was a significant relationship between number of beds and patient‐day‐weighted mean POC‐BG levels, with larger hospitals (≥400 beds) having lower patient‐day weighted mean POC‐BG per patient day than smaller hospitals (<200 beds, P < 0.001). Rural hospitals had higher POC‐BG levels compared to urban and academic hospitals (P < 0.05), and hospitals in the West had the lowest values.

CONCLUSIONS:

POC‐BG data captured through automated data management software can support hospital efforts to monitor the status of inpatient glycemic control. From these data, hospital hyperglycemia is common, hypoglycemia prevalence is low, and POC‐BG levels vary by hospital characteristics. Increased hospital participation in data collection and reporting may facilitate the creation of a national benchmarking process for the development of best practices and improved inpatient hyperglycemia management. Journal of Hospital Medicine 2009;4:E7–E17. © 2009 Society of Hospital Medicine.
“Why did I do this?”: Understanding leadership behavior through a dynamic five‐factor model of leadership
Authors: Seiler Stefan , Pfister Andres C.
Published: December 2009

Leadership theories referring to complex adaptive system theory (CAS) describe leadership as a dynamic process of interdependent, cooperating agents. However, research on leadership behavior focuses mainly on the leader as an influencing, active agent. This article offers a different perspective by focusing on factors that influence leadership behavior. A dynamic five‐factor model of leadership is introduced, which identifies (1) the leader's individual competence, (2) the group, (3) the organization, (4) the context, and (5) the immediate situation as all influencing factors on leadership behavior. To address the problem of the procedural nature of leadership behavior, the dynamic five‐factor model is combined with a scenario‐based approach. The scenario approach focuses on situational developments in a given context, whereby a previous situation influences a leader's behavior in the subsequent situation. By integrating the dynamic five‐factor model into a scenario approach, one can understand a leader's behavior in its procedural nature. The practical usability of the dynamic five‐factor model and the scenario approach was assessed in a leadership development program with 81 military officers. Structured feedback from participants indicated that the model and the approach were perceived as helpful and relevant for understanding leadership behavior.
Spiritual leadership as a model for student inner development
Authors: Fry Louis W. (Jody)
Published: December 2009

“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.”

—from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin
Spirit Guides
Authors: Poole Eve
Published: December 2009

“Although American higher education can justifiably take pride in its capacity to develop the student's ability to manipulate the material world through its programs in science, medicine, technology, and commerce, it has paid relatively little attention to the student's “inner” development—the sphere of values and beliefs, emotional maturity, moral development, spirituality, and self‐understanding.”

—from the Foreword to Encouraging Authenticity and Spirituality in Higher Education by Alexander W. Astin and Helen S. Astin
Suitability of a hydraulic‐conductivity model for predicting salt effects on swelling soils
Authors: Chaudhari Suresh K. , Singh Ravender , Kumar Ashwani
Published: December 2009

Many empirical approaches have been developed to analyze changes in hydraulic conductivity due to concentration and composition of equilibrium solution. However, in swelling soils these approaches fail to perform satisfactorily, mainly due to the complex nature of clay minerals and soil–water interactions. The present study describes the changes in hydraulic conductivity of clay (Typic Haplustert) and clay‐loam (Vertic Haplustept) soils with change in electrolyte concentration (TEC) and sodium‐adsorption ratio (SAR) of equilibrium solution and assesses the suitability of a model developed by Russo and Bresler (1977) to describe the effects of mixed Na‐Ca‐Mg solutions on hydraulic conductivity. Four solutions encompassing two TEC levels viz., 5 and 50 mmolc L–1 and two SAR levels viz., 2.5 and 30 mmol1/2 L–1/2 were synthesized to equilibrate the soil samples using pure chloride salts of Ca, Mg, and Na at Ca : Mg = 2:1. Diluting 50 mmolc L–1 solution to 5 mmolc L–1 reduced saturated hydraulic conductivity of both soils by 66%, and increasing SAR from 2.5 to 30 mmol1/2 L–1/2 decreased saturated hydraulic conductivity by 82% and 79% in clay and clay‐loam soils, respectively. Near saturation, the magnitude of the change in unsaturated hydraulic conductivity due to the change in TEC and SAR was of 103‐ and 102‐fold, and at volumetric water content of 0.20 cm3 cm–3, it was of 1014‐ and 106‐fold in clay and clay‐loam soils, respectively. Differences between experimental and predicted values of saturated hydraulic conductivity ranged between 0.6% and 11% in clay and between 0.06% and 2.1% in clay‐loam soils. Difference between experimental and predicted values of unsaturated hydraulic conductivity widened with drying in both soils. Predicted values were in good agreement with the experimental values of hydraulic conductivity in clay and clay‐loam soils with R2 values of 0.98 and 0.94, respectively. The model can be satisfactorily used to describe salt effects on hydraulic conductivity of swelling soils in arid and semiarid areas, where groundwater quality is poor.
Potassium substitution by sodium in sugar beet (Beta vulgaris) nutrition on K‐fixing soils
Authors: Wakeel Abdul , Steffens Diedrich , Schubert Sven
Published: December 2009

Alluvial soils with illite and vermiculite clay minerals are highly potassium (K)‐fixing. Such soils have been reported to require a huge amount of K fertilization for optimum plant growth. For halophytic plants such as sugar beet, sodium (Na) can be an alternative to K under such conditions. This study was conducted to investigate the possible substitution of K by Na fertilization with reference to K‐fixing soils. Three soils, i.e., Kleinlinden (subsoil), Giessen (alluvial), and Trebur (alluvial), differing in K‐fixing capacities, were selected, and sugar beet plants were grown in Ahr pots with 15 kg soil pot–1. Three treatments (no K and Na, K equal to K‐fixing capacity of soil, and Na equivalent to regular K fertilization) were applied. In a second experiment, containers (90 cm × 40 cm × 40 cm) were used with 170 kg Kleinlinden soil each, and one sugar beet plant per container was grown. In both experiments, plants were grown till beet maturity, and beets were analyzed for sucrose concentration and other quality parameters such as α‐amino nitrogen to calculate white‐sugar yield with the New Brunswick formula. The results showed that growth and quality of sugar beet were not affected by Na application, and ultimately there was no decrease in white‐sugar yield. Moreover, the soils with more K‐fixing capacity were more suitable for K substitution by Na. It is concluded that Na can substitute K in sugar beet nutrition to a high degree and soils with high K‐fixing capacity have more potential for this substitution.
FT‐Raman spectroscopic study of thoracic aortic wall subjected to uniaxial stress
Authors: Hanuza J. , Ma̧czka M. , Ga̧sior‐Głogowska M. , Komorowska M. , Kobielarz M. , Bȩdziński R. , Szotek S. , Maksymowicz K. , Hermanowicz K.
Published: December 2009

The combination of Fourier transform‐Raman spectroscopy and uniaxial tensile tests (in MTS Synergie 100 testing machine) was used to investigate microstructural changes in the secondary protein structure of the aortic wall under different levels of stress. The spectroscopic analysis clearly shows differing tension thresholds for material excised in two directions: circumferential and longitudinal. This is confirmed by the results of macroscopic mechanical analyses. The application of strain does not lead to any noticeable change in the bandwidths of the Raman bands. The stress‐controlled Raman band analysis shows that the modes at 938 cm−1 assigned as CαC of the α‐helix, 1660 cm−1 amide I (the unordered structure of elastin) and 1668 cm−1 amide I (the collagen triple helix) undergo wavenumber shifting, but the bands at 1004 cm−1 assigned to the phenyl ring breathing mode and 2940 cm−1 to the ν (CH3) and ν (CH2) modes are not affected during the elastic behaviour. A clear correlation between Raman band shifting and the level of mechanical stress has been established. Elastin alone participates in the transmission of low stresses in the circumferential direction, whereas both elastin and collagen take part in the transmission of physiological and higher stresses. Copyright © 2009 John Wiley & Sons, Ltd.
Physicochemical properties of octenyl succinic anhydride‐modified potato starch with different degrees of substitution
Authors: Wang Junping , Su Lianghua , Wang Shuo
Published: December 2009

BACKGROUND: Esterified starch is an important type of modified starch. In particular, octenyl succinic anhydride‐modified starch (OSA starch) is widely used in the food industry. However, there has been little research on the properties of products with different degrees of substitution (DS). Therefore the aim of this study was to analyse the physicochemical properties of products with different DS.

RESULTS: OSA starch samples with different DS were prepared from potato starch. Two new peaks were observed in the Fourier transform infrared spectrum, one at 1724 cm−1 due to CO and one at 1572 cm−1 due to RCOO. Emulsifying capacity and emulsion stability improved with increasing DS. Rheological analysis showed the occurrence of the ‘shear‐thinning’ phenomenon, the viscosity of the sample with DS = 0.0211 being even lower than that of native starch. A decrease in syneresis rate from 88.3% (native starch) to 39.0% (DS = 0.0211) indicated that freeze–thaw stability was improved.

CONCLUSION: The physicochemical properties of OSA potato starch were better than those of native potato starch. Freeze–thaw stability, emulsifying capacity and emulsion stability improved with increasing DS. Viscosity increased at lower DS but decreased at DS = 0.0211. Copyright © 2009 Society of Chemical Industry
Is the tourism‐led growth hypothesis stable for Malaysia? A note
Authors: Lean Hooi Hooi , Tang Chor Foon
Published: December 2009

This letter extends the Gunduz and Hatemi‐J study on the tourism‐led growth hypothesis with the Malaysian data. The rolling subsample causality test was employed to demonstrate the validity and stability of the tourism–growth causality relationship. Our result shows the causality relationship is valid and stable over the sample period. Copyright © 2009 John Wiley & Sons, Ltd.
Metal‐complex formation and DNA interaction of 5, 10,15,20‐tetrakis(1‐methyl‐4‐pyridiyl)‐porphine: Study of the mechanistic aspects
Authors: Aydinoglu Sabriye , Biver Tarita , Secco Fernando , Venturini Marcella
Published: December 2009

The macrocyclic porphyrin 5,10,15,20‐tetrakis(1‐methyl‐4‐pyridiyl)‐porphine is studied in its ability to coordinate Cu(II) even at very low pH values and to interact, as a copper complex, with calf‐thymus (CT‐DNA). The kinetics and equilibria for metal‐ligand complexes formation are spectrophotometrically studied, particularly focussing on the mechanistic information provided by the kinetic approach. The rate constants of complex formation is much lower than that of water exchange at Cu(II); this behavior is ascribed to an equilibrium between two porphyrin populations, only one of them being reactive. Concerning the interaction of the copper–porphyrin complex (D) with CT‐DNA, it has been found that the complex binds to G–C base pairs by intercalation while forms external complex with the A–T base pairs. The kinetic results agree with a reaction mechanism that takes into account the slow shuffling from an AT‐bound form (DAT) to a GC‐bound form (DGC) of the copper complex (D), finally leading to a more stable DGC* intercalated form. Kinetic and equilibrium parameters for the copper complex binding to the nucleic acid are obtained, and the binding mechanism is discussed. A mechanism is proposed where D reacts simultaneously with (G–C) and (A–T) base pairs. The resulting bound forms interconvert according to a “shuffling” process, which involves formation of an intermediate (DGC) form. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 79–89, 2010
Corrosion inhibition of copper in tetra‐n‐butylammonium bromide aqueous solution by benzotriazole
Authors: Liu S. , Duan J. M. , Jiang R. Y. , Feng Z. P. , Xiao R.
Published: December 2009

The corrosion inhibition behavior of benzotriazole (BTA) on copper in 17 wt% tetra‐n‐butylammonium bromide (TBAB) aerated aqueous solution was investigated by weight‐loss tests, potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy/energy dispersive X‐ray spectroscopy. BTA is a good inhibitor in 17 wt% TBAB solution. The inhibition efficiency of BTA increases with increasing inhibitor concentration, attaining efficiencies of up to 90% calculated according to different methodologies. Adsorption of BTA in 17 wt% TBAB solution on the copper surface was found to obey the Langmuir adsorption isotherm.
Fullerene Substitution of Donor/Acceptor Branched Disubstituted Polyacetylenes: Significantly Accelerated Polymerization by the C60 Pendant
Authors: Li Minghua , Li Xiaofang , Xu Pan , Yang Shangfeng
Published: December 2009

A novel type of soluble donor/acceptor branched disubstituted polyacetylene (PA–C60) bearing C60 and soft pentyl moieties in side‐chains was synthesized successfully. The product has been characterized by FTIR, 1H NMR, 13C NMR, CH COSY, UV‐vis, and fluorescence spectroscopies, confirming its branched polymeric structure comprising polyacetylene chains and covalently bound C60 cages in side‐chains. Surprisingly, completely different from the conventional metathesis polymerization of acetylenes, it is found for the first time that the disubstituted monomer 4 can be polymerized within a very short reaction time (up to 1.5 min) and the molecular weight of the synthesized PA–C60 is independent of the reaction time. A plausible interpretation is proposed to understand the rapid polymerization reaction accelerated by the C60 pendant. The optical properties of PA–C60 were studied by UV‐vis absorption and fluorescence spectroscopies, which indicated that the fluorescence of PA–C60 is significantly enhanced compared to monomer 4, presumably due to its branched structure. SEM studies on the thin film morphology of PA–C60 in comparison with monomer 4 suggested the successful polymerization of monomer 4 and revealed that PA–C60 has a much smoother morphology than the aggregated morphology of monomer 4.

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A New Synthetic Approach to Thiophene‐Nickel(II)porphyrin Hybrid Molecules and their Electrochemical and Computational Investigation
Authors: Zöllner Mike J. , Frähmcke Jan S. , Elstner Marcus , Jahn Ullrich , Jones Peter G. , Becker Eike , Kowalsky Wolfgang , Johannes Hans‐Hermann
Published: December 2009

New synthetic strategies for thiophene‐nickel(II)porphyrin hybrid molecules are described. Three principles—linear direct, linear spacer and lateral spacer connectivities—were realised and compared with respect to their electrochemical behaviour. Computational investigations by DFT methods confirm experimental data and explain cylic voltammetric oxidations. For the linear direct connectivity, the number of thiophene units per substituted position must be at least two, since the porphyrin core acts as conjugation breaker and hinders the formation of higher oligomers. Alternatively an ethynylene spacer can be introduced to increase conjugation and to optimise the conducting properties. The lateral spacer connection mode proved to be best suited to the electrochemical formation of hybrid compounds.

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In situ Synthesis of Polymer/Clay Nanocomposites by Living and Controlled/Living Polymerization
Authors: Tasdelen Mehmet Atilla , Kreutzer Johannes , Yagci Yusuf
Published: December 2009

The present trend article reports on the recent progress of the in situ synthesis of polymer/clay nanocomposites with well‐defined structures and highly exfoliated morphologies. The methods used for the preparation are classified according to the individual polymerization mechanisms. Other possibilities such as multi‐mode polymerization that combines different polymerization methods and click chemistry are also described. A special emphasis is devoted to the structures and morphologies of the obtained nanocomposites rather than their practical properties.

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Non Linearity of Glassy Polymers
Authors: D'Amore Alberto , Grassia Luigi
Published: December 2009

In this paper the source of non linearity in amorphous materials will be analyzed and verified with phenomenological approaches. A series of simulated results, replicating the relevant experimental data presented in literature along the years, will be reported.
Formulation and Evaluation af a Novel Adhesive Film for Use in Composite Patch Repair
Authors: Tsamasphyros G. , Kalkanis K. , Maroulas P. , Anthoulis G. I. , Grigoryeva O.
Published: December 2009

The current work focuses on the testing of a novel material used as an adhesive film in Composite Patch Repair (CPR). A series of Differential Scanning Calorimetry (DSC) results along with various curing cycles not only led to the optimum material composition but also demonstrated the compatibility to the composite pre‐impregnated patches. This in turn was subjected to mechanical testing including shear strength measurements. The substrate was chosen to be 2017 T4 aluminium alloy which is customarily used in the aerospace industry, taking into account that CPR is a technique mainly applied in this field. The subsequent surface preparation of the specimens was investigated for the specified context resulting to the selection of the Ferric Sulphate Sulphuric acid etching process. Finally, a series of specimens representing actual skin repairs were created and subjected to cyclic loading, specifying the suitability of the novel material, compared to commercially available materials.
Towards a Non Empirical Kinetic Model for the Lifetime Prediction of Polyethylene Pipes Transporting Drinking Water
Authors: Colin Xavier , Audouin Ludmila , Verdu Jacques
Published: December 2009

A kinetic model has been elaborated to predict the lifetime of polyethylene pipes transporting slightly pressurized (3–12 bars) drinking water disinfected by free radical reagents. This model is composed of three levels: i) A system of differential equations, derived from a mechanistic scheme for radical chain oxidation in the presence of free radical reagents, giving access to the spatial distribution (in the pipe wall) of oxidation products and stabilizer concentration; ii) Equations allowing to predict the profiles of average molar masses from the spatial distribution of chain scissions and crosslinking events; iii) An empirical creep equation and a failure criterion derived from regression curves obtained in pure water (without disinfectant). It is assumed that the chemical degradation modifies only the time to transition between ductile and brittle regimes of failure, and that this time is linked to the weight average molar mass according to the classical power law. By superimposing these three levels, it is possible to predict the time to failure under the coupled effects of pressure and chemical degradation. This model is successfully applied to the case of chlorine dioxide.
Degradation of Plasticized PVB During Reprocessing by Kneading
Authors: Měřínská D. , Tupý M. , Kašpárková V. , Popelková J. , Zvoníček J. , Pištěk D. , Svoboda P.
Published: December 2009

Possibility and conditions for optimal re‐processing of plasticized polyvinylbutyral (PVB) were tested. The aim of this work was to investigate degradation of PVB sheet at various kneading conditions and to estimate the influence of temperature, air oxygen and mechanical stress on the progress of degradation process. In order to confirm the influence of humidity on the PVB properties during reprocessing, the sheets with the humidity content of 0.5 and 8.0% were tested. The PVB degradation was determined from the changes of melt flow index, mechanical properties in terms of stress and elongation at break, yellowness and molecular weight distribution. The optimal recycling conditions for PVB were estimated from the evaluation of all measured properties and their changes.
Effect of Initiator on the Over‐Voltage Positive Temperature Coefficient of Linear Low Density Polyethylene/Carbon Black Nano Composites
Authors: Tsai Ching‐Shan , Liu Chia‐I , Tsao Keng‐Yu , Chen Kan‐Nan , Yeh Jen‐Taut , Huang Chi‐Yuan
Published: December 2009

The composite of linear low density polyethylene (LLDPE) with carbon black (CB) and inorganic flame retardant (aluminum hydroxide, Al(OH)3) was prepared by melt‐blending method. The effect of cross‐linking on the stability of positive temperature coefficient (PTC) of composite and the elimination of negative temperature coefficient (NTC) of composite were investigated. LLDPE was chemically cross‐linking with different contents of initiator (dicumyl peroxide, DCP). The cross‐linking effects of composite were analyzed by gel content analysis, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). By the effect of DCP, not only the composite appeared a high PTC intensity, but also the NTC effect of composite was eliminated. In this investigation, the optimum PTC intensity of composite reached 5.87 orders of magnitude for the composition of LLD0.l0C33.7A28, and the PTC transitional temperature of composite decreased with increasing of DCP content. In addition, the good reproducibility of composites was proved by thermal cycling, and successfully passed the test of over‐voltage resistance.
DPD Simulations of PMMA‐Oleic Acid Mixture Behaviour in Organic Capped Nanoparticle Based Polymer Nanocomposite
Authors: Bianchino E. , Piotto S. , Mavelli F. , Curri M. L. , Striccoli M.
Published: December 2009

Dissipative Particle Dynamics has been used to investigate the different morphology of polymer nanocomposites. Such a study was addressed to the definition of a suitable tool for understanding the distribution of oleic acid (OA) capped nanoparticles embedded into poly‐methylmethacrylate (PMMA) matrix for the formation of nanocomposite materials. In particular, simulations of PMMA/OA mixtures at different composition have exhibited the self‐assembly of amphiphiles to form separated nanosized domains with different morphologies going from spheres, to tubules up to the formation of continuous planar sheets as the OA composition increases. On the other hand, simulations carried out on nanocomposite systems have shown that NPs do not perturb the observed phase behaviour of PMMA/OA mixtures. In fact, at low OA compositions nanoparticles are confined in the spherical lipid domains to form NP clusters, while at high OA composition NPs appear homogeneously distributed in the continuous lipid domain.
Reorientational Dynamics of Polyethylene Glycol/PAMAM Dendrimer Blends
Authors: Ristić Sanja , Mijović Jovan
Published: December 2009

The reorientational dynamics of dipoles in a series of blends of Polyethylene Glycol (PEG) and poly(amidoamine) (PAMAM) dendrimers were investigated by broadband dielectric relaxation spectroscopy (DRS). Measurements were performed over a wide range of frequency and temperature. Neat PEG exhibits three relaxation processes: the segmental process in the amorphous phase and two faster processes due to the localized motions in the amorphous regions and the rotation of hydroxyl end groups. Addition of dendrimers to the PEG matrix slows down the segmental process in the amorphous phase, but has no effect on the relaxation time of local processes in PEG. However, H‐bonding which forms between the PEG oxygen and the amino groups on dendrimer surface is responsible for a shift of local processes in dendrimers to lower frequency. A detail analysis of the effect of temperature, concentration of dendrimers and molecular weight of PEG on the relaxation dynamics is offered.
Binding affinity of tea catechins for HSA: Characterization by high‐performance affinity chromatography with immobilized albumin column
Authors: Ishii Takeshi , Minoda Kanako , Bae Min‐Jung , Mori Taiki , Uekusa Yoshinori , Ichikawa Tatsuya , Aihara Yoshiyuki , Furuta Takumi , Wakimoto Toshiyuki , Kan Toshiyuki , Nakayama Tsutomu
Published: December 2009

Catechins are the major polyphenols in green tea leaves. Recent studies have suggested that the catechins form complexes with HSA for transport in human blood, and their binding affinity for albumin is believed to modulate their bioavailability. In this study, the binding affinities of catechins and their analogs were evaluated and the relationship between the chemical structure of each catechin and its binding property were investigated. Comparing these catechins by HPLC analysis with the HSA column, we showed that galloylated catechins have higher binding affinities with HSA than non‐galloylated catechins. In addition, pyrogallol‐type catechins have a high affinity compared to catechol‐type catechins. Furthermore, the binding affinity of the catechin with 2,3‐trans structure was higher than those of the catechin with 2,3‐cis structure. The importance of the hydroxyl group on the galloyl group and B‐ring was confirmed using methylated catechins. These results indicate that the most important structural element contributing to HSA binding of tea catechins is the galloyl group, followed by the number of hydroxyl groups on the B‐ring and the galloyl group or the configuration at C‐2. Our findings provide fundamental information on the relationship between the chemical structure of tea catechins and its biological activity.
Effect of pistachio oil on gene expression of IFN‐induced protein with tetratricopeptide repeats 2: A biomarker of inflammatory response
Authors: Zhang Jun , Kris‐Etherton Penny M. , Thompson Jerry T. , Vanden Heuvel John P.
Published: December 2009

When incorporated into the diet, pistachios have a beneficial effect on lipid and lipoprotein profiles. However, little is known about potential anti‐inflammatory properties. This study was conducted to determine whether pistachio oil and an organic extract from pistachio oil extract (PE) regulated expression of inflammation‐related genes. A mouse macrophage cell line (RAW 264.7 cells) was treated with pistachio oil and gene expression microarray analyses were performed. Pistachio oil significantly affected genes involved in immune response, defense response to bacteria, and gene silencing, of which INF‐induced protein with tetratricopeptide repeats 2 (Ifit‐2) was the most dramatically reduced. PE reduced the LPS‐induced Ifit‐2 by 78% and the bioactive molecules contained in PE, linoleic acid, and β‐sitosterol recapitulated this inhibition. Promoter analysis identified two adjacent IFN‐stimulated response elements, which lie between −110 and −85bp of the 5′‐flanking region of the Ifit‐2 promoter, as being responsive to LPS activation and inhibition by PE. Our results indicate that pistachio oil and bioactive molecules present therein decrease Ifit‐2 expressions, and due to the sensitivity of this effect, this gene is a potential biomarker for monitoring diet‐induced changes in inflammation.
Pyrrolizidine alkaloids in pollen and pollen products
Authors: Kempf Michael , Heil Sandra , Haßlauer Iris , Schmidt Lukas , von der Ohe Katharina , Theuring Claudine , Reinhard Annika , Schreier Peter , Beuerle Till
Published: December 2009

Recently, 1,2‐dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N‐oxides (PANOs, pyrrolizidine N‐oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products. We confirm these findings in regard to floral pollen, using pollen collected directly from flowers of the known PA plants Senecio jacobaea, S. vernalis, Echium vulgare and pollinia of Phalaenopsis hybrids, and we extend analyses of 1,2‐unsaturated PAs and 1,2‐unsaturated PANOs to include bee‐pollen products currently being sold in supermarkets and on the Internet as food supplements. PA content of floral pollen ranged from 0.5 to 5 mg/g. The highest values were observed in pollen obtained from Senecio species. Up to 95% of the PAs are found as PANOs. Detailed studies with S. vernalis revealed unique PA patterns in pollen and flowers. While seneciphylline was the most prominent PA in S. vernalis pollen, the flowers were dominated by senecionine. To analyze trace amounts of 1,2‐unsaturated PAs in pollen products, our previously elaborated method consisting of strong cation exchange‐SPE, two reduction steps followed by silylation and subsequent capillary high‐resolution GC‐MS using SIM mode was applied. In total, 55 commercially available pollen products were analyzed. Seventeen (31%) samples contained 1,2‐unsaturated PAs in the range from 1.08 to 16.35 μg/g, calculated as retronecine equivalents. The 1,2‐unsaturated PA content of pollen products is expressed in terms of a single sum parameter and no background information such as foraged plants, pollen analysis, etc. was needed to analyze the samples. The detection limit of overall procedure and the reliable quantitation limit were 0.003 and 0.01 μg/g, respectively.
Mit Gold von süß zu sauer
Authors: Klein Carmen
Published: December 2009

Zucker goldkatalysiert zu organischen Säuren umzusetzen, ist eine günstige Alternative zum bisherigen mikrobakteriellen Verfahren.
Beraten und gekauft
Authors: Gawert Christoph
Published: December 2009

Unabhängig davon, ob es um Massen‐ oder um Spezialchemikalien geht — mit anwendungstechnischer Beratung lassen sie sich besser vermarkten.
Chemische Konzepte für saubere Abgase
Authors: Kohse‐Höinghaus Katharina
Published: December 2009

Die kontrollierte Nutzung des Feuers machte eine ungeheure technologische Entwicklung möglich. Sie verursacht jedoch auch gesundheitsschädliche und klimawirksame Emissionen. Neue Verbrennungskonzepte sollen zur Lösung des Problems beitragen.
Totalsynthese des Galbulimima‐Alkaloids (—)‐Himandrin
Authors: Graening Timm
Published: December 2009

Eine [3+3]‐Annelierung über eine zweifache Enamin‐Addition ist das synthetische Kernstück bei der Himandrin‐Synthese. Verbunden mit der NCS‐vermittelten Spirocyclisierung auf einer späten Stufe reduziert es das Syntheseproblem auf elegante Weise auf zwei vereinfachte Synthesebausteine.
Harmonie und Dissens:Ostwalds Spuren in Dresden
Authors: Reschetilowski Wladimir , Hegewald Heiner
Published: December 2009

Von 1887 bis 1906 lehrte Wilhelm Ostwald, der Chemie‐Nobelpreisträger des Jahres 1909, an der Universität Leipzig. Doch auch zur sächsischen Residenz‐ und späteren Landeshauptstadt Dresden und ihren Persönlichkeiten aus Staat, Wissenschaft und Wirtschaft unterhielt Ostwald freundschaftliche, manchmal auch kontroverse Beziehungen.
Weder Mensch noch Affe
Authors: Groß Michael
Published: December 2009

Jahrelang haben Wissenschaftler ein Hominidenskelett restauriert sowie die zugehörigen Umweltbedingungen und Nahrungsgewohnheiten analysiert. Nun bewerten die Forscher die menschliche Evolution neu.
”Grund zu neuer Hoffnung“
Authors: Guggolz Ernst , Bulmahn Maren
Published: December 2009

Über die wirtschaftliche Lage und darüber, wie entscheidend Anwendungstechnik für den Unternehmenserfolg ist, sprach Charlie Crew, Präsident und CEO von Sabic Innovative Plastics, mit den Nachrichten aus der Chemie.