bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Carbazole‐Constructed Hyperbranched Polymer: Convenient One‐Pot Synthesis, Hole‐Transporting Ability, and Field‐Effect Transistor Properties
Authors: Li Zhong'an , Liu Yunqi , Yu Gui , Wen Yugeng , Guo Yunlong , Ji Li , Qin Jingui , Li Zhen
Published: July 2009

A new hyperbranched polymer (HB‐car), constructed fully by carbazole moieties, is successfully synthesized through a one‐pot Suzuki coupling reaction. The resultant polymer is well‐characterized, and its hole‐transporting ability is studied carefully. The device, in which HB‐car is utilized as a hole‐transporting layer and tris‐(8‐hydroxyquinoline) aluminum as an electron‐emitting layer as well as electron‐transporting layer, gives a much higher efficiency (3.05 cd A–1), than that of a poly(N‐vinylcarbazole) based device (2.19 cd A–1) under similar experimental conditions. The remarkable performance is attributed to its low energy barrier and enhanced hole‐drifting ability in the HB‐car based device. In addition, for the first time, a field‐effect transistor (FET) based on the hyperbranched polymer is fabricated, and the organic FET device shows that HB‐car is a typical p‐type FET material with a saturation mobility of 1 × 10–5 cm2 V–1 s–1, a threshold voltage of –47.1 V, and an on‐to‐off current ratio of 103.
An analysis of secular change in the human mandible over the last century
Authors: Martin D. C. , Danforth Marie Elaine
Published: July 2009

In light of several recent investigations that have identified notable secular change in cranial size and morphology over the last century, the present study addresses its possible effects in the mandible in U.S. populations. Standard measurements of 407 mandibles from the Terry (Smithsonian) and Hamann‐Todd (Cleveland Museum of Natural History) Collections, which are primarily composed of individuals living in the early 20th century, were compared with those of 595 mandibles from the Forensic Anthropology Database (Tennessee), which is primarily composed of individuals living from the later part of the century. The t‐tests between the two temporally‐different samples by sex and race showed statistically significant decreases in mandibular body width and bigonial breadth as well as significant increases in mandibular body length in nearly all subgroups. White males showed the greatest amount of change, and Black females, the least. Overall, these findings support the conclusion that the mandible is transforming into a longer, narrower, more gracile bone, paralleling many of the morphological shifts seen in the cranium. Factors involved likely include changes in diet, medical care, and dental practices. Am. J. Hum. Biol., 2009. © 2009 Wiley‐Liss, Inc.
Meta‐analysis of brain‐derived neurotrophic factor p.Val66Met in adult ADHD in four European populations
Authors: Sánchez‐Mora C. , Ribasés M. , Ramos‐Quiroga J.A. , Casas M. , Bosch R. , Boreatti‐Hümmer A. , Heine M. , Jacob C.P. , Lesch K‐P. , Fasmer O.B. , Knappskog P.M. , Kooij J.J. Sandra , Kan C. , Buitelaar J.K. , Mick E. , Asherson P. , Faraone S.V. , Franke B. , Johansson S. , Haavik J. , Reif A. , Bayés M. , Cormand B.
Published: July 2009

Attention‐deficit hyperactivity disorder (ADHD) is a multifactorial, neurodevelopmental disorder that often persists into adolescence and adulthood and is characterized by inattention, hyperactivity and impulsiveness. Before the advent of the first genome‐wide association studies in ADHD, genetic research had mainly focused on candidate genes related to the dopaminergic and serotoninergic systems, although several other genes had also been assessed. Pharmacological data, analysis of animal models and association studies suggest that Brain‐Derived Neurotrophic Factor (BDNF) is also a strong candidate gene for ADHD. Several polymorphisms in BDNF have been reported and studied in psychiatric disorders but the most frequent is the p.Val66Met (rs6265G > A) single nucleotide polymorphism (SNP), with functional effects on the intracellular trafficking and secretion of the protein. To deal with the inconsistency raised among different case–control and family‐based association studies regarding the p.Val66Met contribution to ADHD, we performed a meta‐analysis of published as well as unpublished data from four different centers that are part of the International Multicentre Persistent ADHD CollaboraTion (IMpACT). A total of 1,445 adulthood ADHD patients and 2,247 sex‐matched controls were available for the study. No association between the p.Val66Met polymorphism and ADHD was found in any of the four populations or in the pooled sample. The meta‐analysis also showed that the overall gene effect for ADHD was not statistically significant when gender or comorbidity with mood disorders were considered. Despite the potential role of BDNF in ADHD, our data do not support the involvement of p.Val66Met in the pathogenesis of this neuropsychiatric disorder. © 2009 Wiley‐Liss, Inc.
ePaper: A personalized mobile newspaper
Authors: Shapira Bracha , Shoval Peretz , Tractinsky Noam , Meyer Joachim
Published: July 2009

This paper describes ePaper, a research prototype system of a personalized newspaper on a mobile reading device. The ePaper aggregates content (i.e., news items) from various news providers, classifies the news items according to concepts from a news domain ontology, and delivers an electronic newspaper to each subscribed user (reader). The system personalizes the content of the newspaper according to the user's profiles and preferences by applying ontological content‐based and collaborative filtering algorithms. The user's profile is updated implicitly and dynamically, based on the tracking of their reading. Beyond personalization, the ePaper can also provide the user with a “standard edition” of a selected newspaper, as well as browsing capabilities in a repository of news items. The layout of the newspaper is adapted to the specifications of the reading device and to the user's preferences. In this overview paper, we highlight the main research challenges involved in the development of ePaper and describe how we addressed them.
Comparison of the internalization of targeted dendrimers and dendrimer‐entrapped gold nanoparticles into cancer cells
Authors: Shi Xiangyang , Wang Su He , Lee Inhan , Shen Mingwu , Baker James R.
Published: July 2009

Dendrimer‐based nanotechnology significantly advances the area of targeted cancer imaging and therapy. Herein, we compared the difference of surface acetylated fluorescein isocyanate (FI) and folic acid (FA) modified generation 5 (G5) poly(amidoamine) dendrimers (G5.NHAc‐FI‐FA), and dendrimer‐entrapped gold nanoparticles with similar modifications ([(Au0)51.2‐G5.NHAc‐FI‐FA]) in terms of their specific internalization to FA receptor (FAR)‐overexpressing cancer cells. Confocal microscopic studies show that both G5.NHAc‐FI‐FA and [(Au0)51.2‐G5.NHAc‐FI‐FA] exhibit similar internalization kinetics regardless of the existence of Au nanoparticles (NPs). Molecular dynamics simulation of the two different nanostructures reveals that the surface area and the FA moiety distribution from the center of the geometry are slightly different. This slight difference may not be recognized by the FARs on the cell membrane, consequently leading to similar internalization kinetics. This study underlines the fact that metal or inorganic NPs entrapped within dendrimers interact with cells in a similar way to that of dendrimers lacking host NPs. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 936–942, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Human tropoelastin sequence: Dynamics of polypeptide coded by exon 6 in solution
Authors: Tintar D. , Samouillan V. , Dandurand J. , Lacabanne C. , Pepe A. , Bochicchio B. , Tamburro Antonio M.
Published: July 2009

Calorimetric studies were performed on exon 6 in powdered form and in solution [water and 2,2,2‐trifluoroethanol (TFE), a structure‐inducing solvent or cosolvent]. Dynamic dielectric spectroscopy (DDS) analyses were realized in water and 20% TFE. The major role of solvent–peptide organization is evidenced with these techniques. Calorimetric measurements reveal the structural water organization around the polypeptide as well as the presence of hydrophobic interactions in TFE solution. Dielectric measurements showed for exon 6/water a decrease of relaxations times of bulk solvent implying a faster dynamics with a slight increase of the activation entropy, suggesting that exon 6 probably creates disorder within the solvent. For TFE/water mixtures, an influence of exon 6 on its environment was seen with a relaxation associated with the exon 6/solvent interactions reinforced by storage of 72 h. Finally, exon 6/solvent interactions were clearly observed with additionof TFE. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 943–952, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Micronization of lysozyme by supercritical assisted atomization
Authors: Adami Renata , Osséo Libero Sesti , Reverchon Ernesto
Published: July 2009

Supercritical Assisted Atomization (SAA) has been used to produce lysozyme microparticles. Lysozyme has been micronized using water, buffered water at pH 6.2 and water–ethanol mixtures at different volume percentages. Precipitated lysozyme particles were spherical, with a narrow particle size distribution (PSD) ranging from 0.1 to 4 µm. The concentration of lysozyme in the liquid solvent mixture had a nonlinear effect on the particle distribution, with an increase of the X0.9 from about 1 to 3 µm varying the enzyme concentration from 5 to 20 mg/mL. Precipitation temperature was set as low as possible to avoid enzyme degradation. High‐performance liquid chromatography analysis showed no degradation of lysozyme and the enzyme activity, measured by turbidimetric enzymatic assay, only slightly decreased after SAA processing. Depending on the process conditions lysozyme retained from 95% to 100% of the biological activity compared to the untreated enzyme. Biotechnol. Bioeng. 2009; 104: 1162–1170. © 2009 Wiley Periodicals, Inc.
Retracted: De novo synthesis and assembly of multiplex riboswitches in vitro
Authors: Sun Hao‐Hua , Zhu Cong , Wu Ye , Guo Jiang‐Feng
Published: July 2009

Retraction: The following article from Biotechnology Progress, “De novo synthesis and assembly of multiplex riboswitches in vitro”, by Hao‐Hua Sun, Cong Zhu, Ye Wu, and Jiang‐Feng Guo, published online on 14 July 2009 in Wiley Online Library (www.wileyonlinelibrary.com), and in Volume 25, pp. 1228‐1235, has been retracted by agreement between the journal Editor, Michael M. Domach, and Wiley Periodicals, Inc. The retraction has been agreed as Hao‐Hua Sun did not inform all co‐authors of the original submission of the manuscript which is a violation of the journal’s editorial policy.© 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
A versatile software tool for the numerical simulation of fluid flow and heat transfer in simple geometries
Authors: Lopes A. M. G.
Published: July 2009

The present work describes a software tool aimed at the simulation of fluid flow and heat transfer for two‐dimensional problems in a structured Cartesian grid. The software deals with laminar and turbulent situations in steady‐state or transient regime. An overview is given on the theoretical principles and on the utilization of the program. Results for some test cases are presented and compared with benchmarking solutions. Although EasyCFD is mainly oriented for educational purposes, it may be a valuable tool for a first analysis of practical situations. EasyCFD is available at www.easycfd.net. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 18: 14–27, 2010; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20230
Prevalence of childhood abuse in mothers taking part in a study of parenting their own children
Authors: Sneddon Helga , Iwaniec Dorota , Stewart Moira C.
Published: July 2009

This paper describes the incidence of maltreatment histories in a community sample of mothers of one‐year‐old infants in Northern Ireland. The occurrence of five subsets of childhood maltreatment is examined: emotional abuse, emotional neglect, physical abuse, physical neglect and sexual abuse. Of the 201 women who completed the Childhood Trauma Questionnaire, 70 mothers (35%) reported that they had experienced one or more types of maltreatment during childhood. Forty‐eight mothers (24%) gave a history of being emotionally abused, 43 (21%) of emotional neglect, 27 (13%) of physical abuse, 20 (10%) of sexual abuse and 19 (10%) of physical neglect. Physical abuse was the only type of maltreatment which showed an association with maternal socio‐economic status, with a higher incidence reported amongst Occupational Classes 4 and 5 (lower supervisory and technical occupations and semi‐routine and routine groups). More than half of those with a history of abuse experienced more than one type of maltreatment (42 mothers or 60% of those reporting maltreatment). Differences in rates of incidence to more recent studies on younger adults are discussed, as well as implications for prevention and intervention. Copyright © 2009 John Wiley & Sons, Ltd.
Identification of Flavopiridol Analogues that Selectively Inhibit Positive Transcription Elongation Factor (P‐TEFb) and Block HIV‐1 Replication
Authors: Ali Akbar , Ghosh Animesh , Nathans Robin S. , Sharova Natalia , O'Brien Siobhan , Cao Hong , Stevenson Mario , Rana Tariq M.
Published: July 2009

The positive transcription elongation factor (P‐TEFb; CDK9/cyclin T1) regulates RNA polymerase II‐dependent transcription of cellular and integrated viral genes. It is an essential cofactor for HIV‐1 Tat transactivation, and selective inhibition of P‐TEFb blocks HIV‐1 replication without affecting cellular transcription; this indicates that P‐TEFb could be a potential target for developing anti‐HIV‐1 therapeutics. Flavopiridol, a small molecule CDK inhibitor, blocks HIV‐1 Tat transactivation and viral replication by inhibiting P‐TEFb kinase activity, but it is highly cytotoxic. In the search for selective and less cytotoxic P‐TEFb inhibitors, we prepared a series of flavopiridol analogues and evaluated their kinase inhibitory activity against P‐TEFb and CDK2/cyclin A, and tested their cellular antiviral potency and cytotoxicity. We identified several analogues that selectively inhibit P‐TEFb kinase activity in vitro and show antiviral potency comparable to that of flavopiridol, but with significantly reduced cytotoxicity. These compounds are valuable molecular probes for understanding P‐TEFb‐regulated cellular and HIV‐1 gene transcription and provide potential anti‐HIV‐1 therapeutics.
Bisphosphine‐Functionalized Cyclic Decapeptides Based on the Natural Product Gramicidin S: A Potential Scaffold for Transition‐Metal Coordination
Authors: Burck Sebastian , van Assema Sander G. A. , Lastdrager Bas , Slootweg J. Chris , Ehlers Andreas W. , Otero José M. , Dacunha‐Marinho Bruno , Llamas‐Saiz Antonio L. , Overhand Mark , van Raaij Mark J. , Lammertsma Koop
Published: July 2009

The natural product Gramicidin S is a promising scaffold for novel oligopeptide‐based bisphosphine ligands, combining the advantageous rigid chiral backbone with the close proximity of phosphine substituents. The required unnatural, phosphine‐containing, amino acid building blocks were synthesized by means of a novel protocol that involves the enantioselective alkylation of a chiral nickel Schiff base template. Three Ni complexes were prepared with different alkyl chains between the phosphine group and the α‐carbon atom of the incorporated glycine; the absolute stereochemistry of two of them was determined by single‐crystal X‐ray structure analysis. By detaching the template, enantiopure L‐phosphine amino acids resulted enabling the solid‐phase, stepwise construction of a linear sequence of the phosphine‐modified oligopeptides. On cyclization three bisphosphine‐substituted Gramicidin S analogues resulted, differing only in the size and shape of the linkage between the phosphine groups and the oligopeptides backbone. Their crystal structures suggest these species to have potential as chelating ligands.
Self‐assembly and chiral recognition of quartz crystal microbalance chiral sensor
Authors: Luo Miao Li , Zhang Wei Guang , Zhang Sheng , Fan Jun , Su Wen Cui , Yin Xia
Published: July 2009

A novel chiral sensor based on the self‐assembled monolayer of (6A‐ω‐mercaptoethylureado‐6A‐deoxy)heptakis(2,3‐di‐o‐phenylcarbamoyl)‐6B, 6C, 6D, 6E, 6F, 6G‐ hexa‐o‐phenylcarbamoyl‐β‐cyclodextrin (Ph‐β‐CD‐SH) on a quartz crystal transducer for chiral recognition was set up. (R,S)‐(±)‐(3‐Methoxyphenyl)ethylamine were recognized by this QCM chiral sensor with a QCM chiral discrimination factor of 1.33. Furthermore, UV spectroscopy was used to investigate the mechanism of host‐guest interactions between (6A‐azido‐6A‐deoxy)heptakis(2,3‐di‐o‐phenylcarbamoyl)‐6B, 6C, 6D, 6E, 6F, 6G‐hexa‐o‐phenylcarbamoyl‐β‐cyclodextrin (Ph‐β‐CD) and (R,S)‐(±)‐(3‐methoxyphenyl) ethylamine. The UV discrimination factor was determined to be 0.066. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Ultrasound‐mediated synthesis of camphoric acid‐based chiral salens for the enantioselective trimethylsilylcyanation of aldehydes
Authors: Serra Maria E. Silva , Murtinho Dina , Goth Albertino , Rocha Gonsalves António M. D'A. , Abreu Paulo E. , Pais Alberto A. C. C.
Published: July 2009

New chiral salen ligands were prepared by the ultrasound‐irradiated condensation of optically active (1R, 3S)‐1,2,2‐trimethyl‐1,3‐diaminocyclopentane with aromatic 1‐hydroxyaldehydes. The ultrasound‐mediated process is more convenient due to shorter reaction times, energy economy, and easier isolation of the products. The in situ formed Ti(IV)(salen) complexes, evaluated as catalysts in the enantioselective trimethylsilylcyanation of benzaldehyde, were found to be efficient for this process, originating the corresponding product in high yields (72–99%) and selectivities of up to 79%. The lowest energy transition states were determined by computational studies. These results were in qualitative agreement with the experimentally observed ones. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
The search for meaning—Symptoms and transvaginal sonography screening for ovarian cancer
Authors: Pavlik Edward J. , Saunders Brook A. , Doran Stacey , McHugh Katherine W. , Ueland Frederick R. , DeSimone Christopher P. , DePriest Paul D. , Ware Rachel A. , Kryscio Richard J. , van Nagell John R.
Published: July 2009

BACKGROUND:

The mortality rate of ovarian cancer is greater than that of all other major gynecologic malignancies. Detecting ovarian cancer at an early and curable stage long has been an objective of oncologists. Recently, it was reported that certain symptom patterns are informative for the presence of ovarian malignancy. In this article, the authors report on how symptoms and ultrasound predict ovarian malignancy.

METHODS:

Two hundred seventy‐two women who were participating in annual transvaginal sonography (TVS) screening were selected from among 31,748 women who were enrolled. Symptom results were correlated with ultrasound and surgical pathology findings.

RESULTS:

TVS performed better than symptoms analysis for detecting malignancies (sensitivity, 73.3% vs 20%), and symptoms analysis performed better for distinguishing benign tumors (specificity, 91.3% vs 74.4%). The use of TVS and symptoms analysis in series resulted in poorer identification of malignancy (sensitivity, 16.7%) but improved the ability to distinguish benign tumors (specificity, 97.9%). Decisions using either symptoms or TVS combined in parallel had small increases in sensitivity (+3.3%) and had coordinated, small decreases in specificity (−5.8%).

CONCLUSIONS:

Symptoms did identify ovarian malignancies, but not as well as TVS. The current findings indicated that: 1) tumors that are negative by both ultrasound and a symptoms index are likely to be benign (specificity, >97%), and 2) adding symptoms information that has weight equal to the weight of ultrasound only slightly improves the discrimination of malignancy (sensitivity increase, +3.3%). Thus, a major benefit in discriminating malignancy was achieved through ultrasound, whereas the absence of symptoms in conjunction with an abnormal ultrasound (characterized by a low morphology index) indicated that the mass was benign and that surgery may not be required. Finally, informative symptoms can be expected to be absent in 80% of patients with ovarian malignancies. Cancer 2009. © 2009 American Cancer Society.
Analysis of epigenetic alterations to chromatin during development
Authors: Minard Meghan E. , Jain Abhinav K. , Barton Michelle Craig
Published: July 2009

Each cell within a multicellular organism has distinguishable characteristics established by its unique patterns of gene expression. This individual identity is determined by the expression of genes in a time and place‐dependent manner, and it is becoming increasingly clear that chromatin plays a fundamental role in the control of gene transcription in multicellular organisms. Therefore, understanding the regulation of chromatin and how the distinct identity of a cell is passed to daughter cells during development is paramount. Techniques with which to study chromatin have advanced rapidly over the past decade. Development of high throughput techniques and their proper applications has provided us essential tools to understand the regulation of epigenetic phenomena and its effect on gene expression. Understanding the changes that occur in chromatin during the course of development will not only contribute to our knowledge of normal gene expression, but will also add to our knowledge of how gene expression goes awry during disease. This review opens with an introduction to some of the key premises of epigenetic regulation of gene expression. A discussion of experimental techniques with which one can study epigenetic alterations to chromatin during development follows, emphasizing recent breakthroughs in this area. We then present examples of epigenetic mechanisms exploited in the control of developmental cell fate and regulation of tissue‐specific gene expression. Finally, we discuss some of the frontiers and challenges in this area of research. genesis 47:559–572, 2009. © 2009 Wiley‐Liss, Inc.
A mouse model for visualization of GABAB receptors
Authors: Casanova Emilio , Guetg Nicole , Vigot Réjan , Seddik Riad , Julio‐Pieper Marcela , Hyland Niall P. , Cryan John F. , Gassmann Martin , Bettler Bernhard
Published: July 2009

GABAB receptors are the G‐protein‐coupled receptors for the neurotransmitter γ‐aminobutyric acid (GABA). Receptor subtypes are based on the subunit isoforms GABAB1a and GABAB1b, which combine with GABAB2 subunits to form heteromeric receptors. Here, we used a modified bacterial artificial chromosome (BAC) containing the GABAB1 gene to generate transgenic mice expressing GABAB1a and GABAB1b subunits fused to the enhanced green fluorescence protein (eGFP). We demonstrate that the GABAB1‐eGFP fusion proteins reproduce the cellular expression patterns of endogenous GABAB1 proteins in the brain and in peripheral tissue. Crossing the GABAB1‐eGFP BAC transgene into the GABAB1−/− background restores pre and postsynaptic GABAB functions, showing that the GABAB1‐eGFP fusion proteins substitute for the lack of endogenous GABAB1 proteins. Finally, we demonstrate that the GABAB1‐eGFP fusion proteins replicate the temporal expression patterns of native GABAB receptors in cultured neurons. These transgenic mice therefore provide a validated tool for direct visualization of native GABAB receptors. genesis 47:595–602, 2009. © 2009 Wiley‐Liss, Inc.
Cell adhesive affinity does not dictate primitive endoderm segregation and positioning during murine embryoid body formation
Authors: Moore Robert , Cai Kathy Q. , Escudero Diogo O. , Xu Xiang‐Xi
Published: July 2009

The classical cell sorting experiments undertaken by Townes and Holtfreter described the intrinsic propensity of dissociated embryonic cells to self‐organize and reconcile into their original embryonic germ layers with characteristic histotypic positioning. Steinberg presented the differential adhesion hypothesis to explain these patterning phenomena. Here, we have reappraised these issues by implementing embryoid bodies to model the patterning of epiblast and primitive endoderm layers. We have used combinations of embryonic stem (ES) cells and their derivatives differentiated by retinoic acid treatment to model epiblast and endoderm cells, and wild‐type or E‐cadherin null cells to represent strongly or weakly adherent cells, respectively. One cell type was fluorescently labeled and reconstituted with another heterotypically to generate chimeric embryoid bodies, and cell sorting was tracked by time‐lapse video microscopy and confirmed by immunostaining. When undifferentiated wild‐type and E‐cadherin null ES cells were mixed, the resulting cell aggregates consisted of a core of wild‐type cells surrounded by loosely associated E‐cadherin null cells, consistent with the differential adhesion hypothesis. However, when mixed with undifferentiated ES cells, the differentiated primitive endoderm‐like cells sorted to the surface to form a primitive endoderm layer irrespective of cell‐adhesive strength, contradicting the differential adhesion hypothesis. We propose that the primitive endoderm cells reach the surface by random movement, and subsequently the cells generate an apical/basal polarity that prevents reentry. Thus, the ability to generate epithelial polarity, rather than adhesive affinity, determines the surface positioning of the primitive endoderm cells. genesis 47:579–589, 2009. © 2009 Wiley‐Liss, Inc.
Misexpression of Gbx2 throughout the mesencephalon by a conditional gain‐of‐function transgene leads to deletion of the midbrain and cerebellum in mice
Authors: Sunmonu N. Abimbola , Chen Li , Li James Y.H.
Published: July 2009

The mouse homeobox gene, Gbx2, is expressed in discreet domains in the neural tube and plays a key role in forebrain and hindbrain development. Previous studies have demonstrated that mutual inhibition between Gbx2 and Otx2, which are respectively expressed in the anterior and posterior parts of the neural plate, positions the prospective midbrain–hindbrain junction. We describe here a conditional Gbx2 gain‐of‐function transgenic mouse line, Gbx2‐GOF, which expresses Gbx2 and red fluorescence protein, mCherry, upon Cre‐mediated recombination. In the absence of Cre, β‐galactosidase is broadly expressed in mouse embryos and adult brains carrying the transgene. By combining Gbx2‐GOF and En1Cre knock‐in allele, we activated expression of Gbx2 and mCherry throughout the mesencephalon (mes) and rhombomere 1 (r1). The ectopic expression of Gbx2 causes an anterior shift of the mes/r1 junction at embryonic day 10.5. Interestingly, we found that persistent expression of Gbx2 throughout the mes/r1 region largely abolishes expression of the isthmic organizer gene Fgf8, leading to deletion of the midbrain and cerebellum at later stages. Our data suggest that the juxtaposition of the expression domains of Gbx2 and Otx2 within the mes/r1 area is essential for the maintenance of Fgf8 expression. Furthermore, the Gbx2‐GOF transgenic line is suitable for functional study of Gbx2 during development. genesis 47:667–673, 2009. © 2009 Wiley‐Liss, Inc.
Capn8 promoter directs the expression of Cre recombinase in gastric pit cells of transgenic mice
Authors: Zhao Zengming , Sun Yanxun , Hou Ning , Teng Yan , Wang Youliang , Yang Xiao
Published: July 2009

Gastric pit cells are high‐turnover epithelial cells of the gastric mucosa. They secrete mucus to protect the gastric epithelium from acid and pepsin. To investigate the genetic mechanisms underlying the physiological functions of gastric pit cells, we generated a transgenic mouse line, namely, Capn8‐Cre, in which the expression of Cre recombinase was controlled by the promoter of the intracellular Ca2+‐regulated cysteine protease calpain‐8. To test the tissue distribution and excision activity of Cre recombinase, the Capn8‐Cre transgenic mice were bred with the ROSA26 reporter strain and a mouse strain that carries Smad4 conditional alleles (Smad4Co/Co). Multiple‐tissue PCR and LacZ staining demonstrated that Capn8‐Cre transgenic mouse expressed Cre recombinase in the gastric pit cells. Cre recombinase activity was also detected in the liver and skin tissues. These data suggest that the Capn8‐Cre mouse line described here could be used to dissect gene function in gastric pit cells. genesis 47:674–679, 2009. © 2009 Wiley‐Liss, Inc.
Synthesis of Zinc Glycerolate Microstacks from a ZnO Nanorod Sacrificial Template
Authors: Rémiás Róbert , Kukovecz Ákos , Darányi Mária , Kozma Gábor , Varga Szilvia , Kónya Zoltán , Kiricsi Imre
Published: July 2009

We synthesized zinc glycerolate (ZnGly) microstacks bytreating ZnO with glycerol at 100 °C under reflux. We observed that the morphology of the ZnO source has a pronounced effect on the appearance of the ZnGly product. In the absence of structure‐directing effects the product ZnGly is obtained as a random heap of hexagonal prisms with an average diameter and thickness of ca. 2.5 μm and ca. 350 nm, respectively. However, bundles of nanorod‐shaped ZnO obtained by the thermal decomposition of zinc oxalate nanorods could readily be transformed into 2–4 μm long zinc glycerolate microstacks in which 6–12 hexagonal prisms are aligned face‐to‐face. We present evidence that the ZnGly plates in the microstacks are bound together by forces strong enough to withstand mechanical deformation exercised by a contacting AFM tip. The ZnGly microstacks appear to emerge from the ZnO nanorod bundles in an approx. 1:1 ratio in the reactive template synthesis.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Alkyl‐Bridged Bis‐5‐azidotetrazoles: A Safe Way of Preparation
Authors: Klapötke Thomas M. , Sproll Stefan M.
Published: July 2009

The general, high‐yielding synthesis of extremely dangerous alkylated bis‐5‐azidotetrazoles is presented. The preparation using 5‐bromotetrazoles for the generation of tetrazolyl hydrazines, which are then converted into the corresponding bis‐5‐azidotetrazoles, presents a safe, large‐scale preparation of alkylated bis‐5‐azidotetrazoles. In this work, 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)ethane, 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)‐1‐methylethane, and 1,4‐bis(5‐azido‐1H‐tetrazol‐1‐yl)butane were synthesized and characterized by 1H, 13C, and 15N NMR spectroscopy, vibrational spectroscopy (IR), and mass spectrometry. The crystal structure of 1,2‐bis(5‐azido‐1H‐tetrazol‐1‐yl)ethane was determined by single‐crystal X‐ray diffraction. In addition, the thermal behavior of the bis‐5‐azidotetrazoles was investigated by differential scanning calorimetry and their sensitivity towards friction and impact were determined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Morita–Baylis–Hillman Reactions Between Conjugated Nitroalkenes or Nitrodienes and Carbonyl Compounds
Authors: Deb Indubhusan , Shanbhag Pramod , Mobin Shaikh M. , Namboothiri Irishi N. N.
Published: July 2009

Morita–Baylis–Hillman (MBH) reactions between conjugated nitroalkenes or nitrodienes and various carbonyl compounds such as glyoxylate, trifluoropyruvate, pyruvaldehyde, oxomalonate, ninhydrin, and formaldehyde have been extensively investigated. The reactions proceeded smoothly in the presence of DMAP (40–100 mol‐%) in acetonitrile and in some cases also in that of imidazole (100 mol‐%) in CHCl3 or THF, to provide the multifunctional adducts in good to excellent yields. The reactions catalyzed by DMAP in acetonitrile were superior to the imidazole‐catalyzed reactions both in terms of the rate of reaction and in terms of the isolated yields of the MBH adducts. The catalytic roles played by DMAP and imidazole in these reactions, vis‐à‐vis other MBH catalysts such as DABCO, are attributed primarily to resonance stabilization of the initial zwitterionic intermediates. Whereas the E isomers are the major or exclusive products in the cases of glyoxylate, pyruvaldehyde, and formaldehyde, the Z isomers predominate in the cases of trifluoropyruvate and ninhydrin. Interestingly, oxomalonate forms E isomers with aromatic nitroalkenes and Z isomers with aliphatic ones. These selectivities and the formation of unusual deconjugated products in the case of certain β‐alkyl‐nitroethylenes have been explained.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Quantifying Primary Silver Ions Contents in Poly(vinyl chloride) and Poly(n‐butyl acrylate) Ion‐Selective Membranes
Authors: Michalska Agata , Wojciechowski Marcin , Bulska Ewa , Maksymiuk Krzysztof
Published: July 2009

On a model example of silver selective, poly(vinyl chloride) (PVC) or poly(n‐butyl acrylate) based plastic membranes, a method of primary ions quantification has been proposed. For this purpose the inductively coupled plasma mass spectrometry with laser ablation (LA ICP MS) was used. Significant differences of the ions distribution between examined membranes materials were observed. For both kinds of membranes the influence of the concentration of AgNO3 in conditioning solution was noticed. Conditioning in 0.1 M solution resulted in a few times higher silver levels compared to expected for 100 mol% membrane saturation (relative to lipohilic salt content). This points to pronounced co‐extraction of quite lipophilic nitrate anions. In the case of poly(n‐butyl acrylate) based membranes, silver was accumulated mainly in the surface domain of the membrane, due to low mobility of silver ions in this material. This was experimentally proved by concentration profiles of silver across the poly(n‐butyl acrylate) membrane, showing a lower contents inside the membrane, being in contrast to uniform distribution in PVC based matrix. The obtained silver contents in the membranes correlates well with potentiometric characteristic, low contents of silver corresponds to super‐Nernstian responses in low Ag+ activities range, for about 75% of saturation the detection limit close to 10−8 M is obtained, 100% saturation or even higher silver contents results in micromolar detection limits.
Metrological Aspects of Glucose Measurements by Biosensors
Authors: Wunderli Samuel , Andres Hanspeter
Published: July 2009

In a chronoamperometric measurement the chemical activity of glucose is directly determined using a glucose sensitive biosensor based on glucose oxidase and an efficient mediator. Within the physiological range of 2 mmol kg−1 and 10 mmol kg−1 glucose in aqueous solutions behaves almost ideally and the chemical activity equals the glucose molality, the amount of glucose per unit mass of water, within the estimated measurement uncertainty. In physiological samples the equality between chemical activity and glucose molality is destroyed and has to be corrected for. Gravimetrically prepared mixtures of high purity glucose in buffered aqueous solutions are used as standards for calibration of the chronoamperometric measurement setup. Based on the model equation for the measurand aqueous or physiological sample, all significant sources of uncertainty are identified, their magnitude estimated from published and experimental data and finally combined to give the uncertainty in the reported value of the glucose molality. It is found, that the combined uncertainty of the glucose molality comprises mainly uncertainty contributions from the nonideal behavior, the chronoamperometric measurement setup, from the purity of glucose used and from the chemical composition of the test sample. The expanded uncertainty is below 2% rel., the glucose content determined by the bioelectrochemical measurements thus competes well with today's considered most accurate reference method Isotope Dilution Mass Spectrometry. Advantageous of the presented electroanalytical method is the direct measure of the glucose molality without prior sample preparation and dilution.
Calixarene/Nafion‐Modified Bismuth‐Film Electrodes for Adsorptive Stripping Voltammetric Determination of Lead
Authors: Torma Ferenc , Grün Alajos , Bitter Isván , Tóth Klára
Published: July 2009

This paper presents an enhanced adsorptive stripping voltammetric procedure (AdSV) for the determination of Pb2+, which relies on the accumulation of the metals at a calixarene‐based chemically modified bismuth‐film electrode on glassy carbon substrate. Following the accumulation of the target metals at open circuit and a medium exchange, both the square wave anodic stripping detection of the metal ions and the in situ bismuth‐film formation was performed simultaneously in a Bi3+ containing supporting electrolyte. The analysis of Pb2+ under optimized conditions resulted in stripping responses with good linearity (in the range 0.05–0.6 μM) and precision (RSD=1.12% at 0.2 μM Pb2+; n=10) and low detection limit (0.02 μg/L at 10 min preconcentration). The determination of Pb2+ (0.4 μM) at 100‐fold excess of interfering ions (Cd2+, Cu2+ and Zn2+) yielded well resolved lead signal. The analytical utility of the method elaborated was tested in the analysis of trace Pb2+ in environmental water samples.
Lower Rim Substituted p‐tert‐Butyl‐Calix[4]arene. Part 15. Pb(II)‐Ion‐Selective Electrodes Based on p‐tert‐Butyl‐calix[4]arene Thioamides
Authors: Bocheńska Maria , Guziński Marcin , Kulesza Joanna
Published: July 2009

Tetrasubstituted p‐tert‐butylcalix[4]arene‐thioamides (1–5) were applied as ionophores in ion‐selective membrane electrodes (ISE) and were tested towards Pb‐selectivity. The selectivity coefficients of the electrodes were determined. The tertiary calix[4]thioamides (1, 2) show remarkable selectivity for Pb(II) cations when compared with respectable calix[4]amides. The electrode membranes with those ligands are stable, the Pb‐characteristics are close to nernstian within a wide linear range (−log c=6–1). Compounds 3–5, the secondary calix[4]thioamides form less stable electrode membranes. Complex formation constants of the ligands 1, 2, 3 and 5 with Pb(II) and some most interfering ions were determined.
Estimation of Ion‐Pairing Constants in Plasticized Poly(vinyl chloride) Membranes Using Segmented Sandwich Membranes Technique
Authors: Egorov Vladimir V. , Lyaskovski Peter L. , Il'inchik Irina V. , Soroka Vera V. , Nazarov Valentine A.
Published: July 2009

Segmented sandwich membrane method was used to determine ion‐pairing constants for four cationic sites: tris‐(2,3,4‐dodecyloxy)benzenetrimethylammonium, tris‐(2,3,4‐dodecyloxy)benzenedimethyloctylammonium, tris‐(2,3,4‐dodecyloxy)benzenemethyldioctylammonium, and dimethyldioctadecylammonium with chloride, bromide, nitrate, benzene sulfonate, trichloroacetate, thiocyanate, perchlorate and picrate, as well as ion‐pairing constants for two anionic sites: tetraphenylborate and tris‐(2,3,4‐octyloxy)benzenesulfonate with dimedrol, quinine, anapriline, and amantadine cations in poly(vinyl chloride) membranes plasticized with 2‐nitrophenyl octyl ether. Ion association constants of anions with quaternary ammonium sites regularly increase from picrate to chloride along with reduction of the anion radius and with improvement of site exchanger center steric accessibility. Ion association constants of amine cations with tris‐(2,3,4‐octyloxy)benzenesulfonate are several orders higher than those with tetraphenylborate and regularly increase from tertiary amine to primary one.
Non‐Gaussian state space models in decomposition of ice core time series in long and short time‐scales
Authors: Bojarova Jelena , Sundberg Rolf
Published: July 2009

Statistical modelling of six time series of geological ice core chemical data from Greenland is discussed. We decompose the total variation into long time‐scale (trend) and short time‐scale variations (fluctuations around the trend), and a pure noise component. Too heavy tails of the short‐term variation makes a standard time‐invariant linear Gaussian model inadequate. We try non‐Gaussian state space models, which can be efficiently approximated by time‐dependent Gaussian models. In essence, these time‐dependent Gaussian models result in a local smoothing, in contrast to the global smoothing provided by the time‐invariant model. To describe the mechanism of this local smoothing, we utilise the concept of a local variance function derived from a heavy‐tailed density. The time‐dependent error variance expresses the uncertainty about the dynamical development of the model state, and it controls the influence of observations on the estimates of the model state components. The great advantage of the derived time‐dependent Gaussian model is that the Kalman filter and the Kalman smoother can be used as efficient computational tools for performing the variation decomposition. One of the main objectives of the study is to investigate how the distributional assumption on the model error component of the short time‐scale variation affects the decomposition. Copyright © 2009 John Wiley & Sons, Ltd.
Experimental study on earthquake‐induced pounding between structural elements made of different building materials
Authors: Jankowski Robert
Published: July 2009

The phenomenon of earthquake‐induced structural pounding has attracted the researchers' attention for several years now. The aim of this paper is to show the results of two experiments concerning interactions between elements made of different building materials, such as steel, concrete, timber and ceramic. The first experiment was conducted by dropping balls from different height levels onto a rigid surface, whereas the second one was focused on pounding‐involved response of two tower models excited on a shaking table. The results of the impact experiment show that the value of the coefficient of restitution depends substantially on the prior‐impact velocity as well as on the material used. Based on these results, the appropriate formulations have been suggested to be applied in the numerical simulations. The results of the shaking table tests show a considerable influence of the material used for colliding elements on the behaviour of structures during earthquakes. Copyright © 2009 John Wiley & Sons, Ltd.
Analysis of the behaviour of the structural concrete after the fire at the Windsor Building in Madrid
Authors: Menéndez E. , Vega L.
Published: July 2009

The analysis of the concrete subjected to high temperatures is usually undertaken by means of tests specifically designed and carried out in the laboratory, or by using theoretical approaches using standardized curves for theoretical fires.

An analysis by different techniques has been carried out on structural concrete to real fire of Windsor Building in Madrid, which was severally damaged by a fire in 2005. These techniques are X‐ray diffraction, differential thermal and thermogravimetric analysis and backscattered electron microscopy with dispersive X‐ray microanalysis. Samples of the concrete were taken from different floors in the building and analyses were carried out at different depths starting from the surface exposed to the fire itself. The analysis allows the damaged area to be limited as well as situating the 500∘C isotherm in the concrete element.

In accordance with the results obtained, the damage is limited to just a few centimeters from the surface exposed to the fire itself, in spite of its prolonged exposure to the fire. This would justify that the concrete has demonstrated a suitable resistant behaviour. Likewise, it can be deduced from the results obtained that the fire, to which the concrete was subjected, can be qualified as severe.

Also, these results can confirm that the calculation hypothesis in the project is correct in relation to the fire resistance exigencies of the concrete. Copyright © 2009 John Wiley & Sons, Ltd.
3D tangentially injected swirling recirculating flow in a nozzle with a slotted‐tube—Effects of groove parameters
Authors: Guo Hui‐Fen , Chen Zhi‐Yong , Yu Chong‐Wen
Published: July 2009

A numerical prediction for 3D swirling recirculating flow in an air‐jet spinning nozzle with a slotted‐tube is carried out with the realizable k–ε turbulence model. The effects of the groove parameters on the flow and yarn properties are investigated. The simulation results show that some factors, such as reverse flow upstream of the injector, vortex breakdown downstream of the injector, corner recirculation zone (CRZ) behind the step and vortex ring in the groove caused by the groove geometric variation, are significantly related to fluid flow, and consequently to yarn properties. With increasing groove height, the length of the CRZ increases, while the initial vortex ring in the groove decreases and a same direction rotating vortex forms in the bottom of the groove. Similarly, as the groove width increases, the extent of both vortex breakdown in downstream of the injectors and the vortex ring in the groove increases slightly, whereas the CRZ lengths in stream‐wise direction decrease. Some factors, such as the negative tangential velocities, the size of the vortex rings in the grooves and the CRZ, are constant for nozzles with different groove lengths. Copyright © 2009 John Wiley & Sons, Ltd.
The Nanocrystalline Nickel with Catalytic Properties on Methanol Oxidation in Alkaline Medium
Authors: Tehrani R. M. A. , Ab Ghani S.
Published: July 2009

The hexagonal closed packed (hcp) nanocrystalline nickel (Ni), with an average diameter of 9.7 ± 2.27 nm was deposited uniformly on composite graphite (CG) by the rapid scanning (6,500 mVs–1) voltammetry technique. The hcp‐nano Ni‐modified CG electrode was investigated for the catalytic oxidation of methanol in alkaline medium through the formation of NiOOH. A high anodic current was obtained at peak potential of +570 mV vs Ag/AgCl. Both the scan rate and the methanol concentration affected the oxidation of methanol. The results showed that catalytic activity had increased with decrease in Ni particle diameter. It was also shown that the hcp‐nano Ni/CG modified electrode was the most efficient catalyst in the oxidation of methanol.
Testing a Vapour‐fed PBI‐based Direct Ethanol Fuel Cell
Authors: Lobato J. , Cañizares P. , Rodrigo M. A. , Linares J. J.
Published: July 2009

This work is focused on the application and performance of a high temperature PBI‐based direct ethanol fuel cell, studying the influence of some operating variables such as the temperature, ethanol concentration and oxygen partial pressure. An increase in the temperature resulted in an improvement of the cell performance due to the enhanced electrodic kinetic and electrolyte conductivity. An ethanol/water weight ratio between 0.25 and 0.5 was found to be suitable for providing both enough water and fuel availability to make the ethanol oxidation possible. Measurements of the ethanol crossover at different temperatures and concentrations were carried out. An intermittent lifetime test showed that the cell, after several hours, was able to reach stability. Moreover, its performance was completely reversible with no perceptible losses for 7 days. Finally, tests using bio‐ethanol as fuel were performed, with no significant power losses. This final feature is of special interest from a practical ‘green' point of view.