bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anion‐Templated Calix[4]arene‐Based Pseudorotaxanes and Catenanes
Authors: Lankshear Michael D. , Evans Nicholas H. , Bayly Simon R. , Beer Paul D. 
Published: April 2007

AbstractWe present the rational design and anion‐binding properties of the first anion‐templated pseudorotaxanes and catenanes in which the “wheel” component is provided by a calix[4]arene macrobicyclic unit. The designs and syntheses of two new calix[4]arene macrobicycles, 2 and 3, are presented, and the abilities of these new species both to bind anions and to undergo anion‐dependent pseudorotaxane formation are demonstrated. Furthermore, it is shown that performing ring‐closing metathesis reactions on some of these pseudorotaxane assemblies gives novel catenane species 14 and 15, in which the yield of interlocked molecule obtained is critically dependent on the presence of a suitable anion template, namely, chloride. Exchange of the chloride anion in catenane 14 a for hexafluorophosphate gives catenane 14 d, which contains a unique anion‐binding domain defined by the permanently interlocked hydrogen‐bond‐donating calix[4]arene macrobicycle and pyridinium macrocycle fragments. The anion‐binding properties of this domain are presented, and shown to differ from non‐interlocked components.
Vibrational Spectroscopic Study on Ion Solvation and Association of Lithium Perchlorate in 4‐Methoxymethyl‐ethylene Carbonate
Authors: Qiao Hong‐Wei , Luan He‐Lin , Zhou Zhi‐Ming , Yao Wen 
Published: April 2007

AbstractSolvation interaction and ion association in solutions of lithium perchlorate/4‐methoxymethyl‐ethylene carbonate (MEC) have been studied by using Infrared and Raman spectra as a function of concentration of lithium perchlorate. The splitting of ring deformation band and ring ether asymmetric stretching band, and the change of carbonyl stretching band suggest that there should be a strong interaction between Li+ and the solvent molecules, and the site of solvation should be the oxygen atom of carbonyl group. The apparent solvation number of Li+ was calculated by using band fitting technique. The solvation number was decreased from 3.3 to 1.1 with increasing the concentration of LiClO4/MEC solutions. On the other hand, the band fitting for the ClO−4 band revealed the presence of contact ion pair, and free ClO−4 anion in the concentrated solutions.
Preparation and Photocatalytic Properties of Ti1−xZrxO2 Solid Solution
Authors: Gao Bi‐Fen , Ma Ying , Cao Ya‐An , Gu Zhan‐Jun , Zhang Guang‐Jin , Yao Jian‐Nian 
Published: April 2007

AbstractA series of Ti1−xZrxO2 materials were synthesized through a multistep sol‐gel process. The structural characteristics were investigated using X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and Raman measurements. The experimental results showed that a solid solution could be obtained at low Zr/(Ti+Zr) molar ratios (x≦0.319). Raman measurements exhibited that the presence of zirconium in the solid solutions greatly retarded the amorphous‐anatase and anatase‐rutile transitions. The diffuse reflectance UV‐Vis spectra revealed that the bandgap of the solid solution was enlarged gradually with the increment of incorporated zirconium content. The Ti1−xZrxO2 solid solutions exhibited higher photocatalytic activity than pure TiO2 for the degradation of 4‐chlorophenol aqueous solution.
Elements in the Sera of Preschool Children Living in Central Taiwan
Authors: Chen Chien‐Yi , Lin Ding‐Bang , Chen Wen‐Kang 
Published: April 2007

AbstractThis study assessed elemental concentrations in the serum of 154 preschool children in central Taiwan via instrumental neutron activation analysis (INAA). A total of eight elements, Br, Cl, Fe, Na, Rb, Sc, Se and Zn of sera for Taiwanese preschool children living at four residential areas:Taichung city, Taichung urban townships and in a remote area inhabited by two groups of aborigines, Atayal and Bunun were determined. Standard reference materials (tomato leaves, NIST‐SRM 1570a, and lichen, IAEA‐336) were used as quality control standards to crosscheck the accuracy. Residential area, socioeconomic status and gender were shown to significantly influence serum levels of the eight trace elements. Statistical analysis revealed several different gender patterns via the two‐tailed student's test. A quantified index of agreement (AT) was used to classify these elements. Small AT indicated a close consistency, while large AT indicated a larger fluctuation, or less agreement, such that the correlation between the elements could be interpreted using a series of quantified indices at the serum levels of preschool children.
Polymer‐Supported Chiral Monodentate Phosphoramidites in Palladium‐Catalyzed Allylic Alkylation Reactions
Authors: Jiang Zhi‐Dong , Meng Zhao‐Hai 
Published: April 2007

AbstractA new and simple method for immobilization of monodentate chiral ligand on the cheap resin has been developed. A series of resin‐immobilized phosphoramidite ligands based on BINOL and TADDOL backbones have been synthesized and characterized with gel‐phase NMR. The immobilized ligands have been applied to the Pd‐catalyzed asymmetric allylic alkylation of 1,3‐diphenyl‐2‐propenyl acetate. Among four ligands, the supported bulky monodentate phosphoramidite ligand based on TADDOL backbone afforded the chiral product with ee up to 65%; moreover, this ligand could be recycled for 3 times without substantial decrease of the conversion and ee.
Reduced Species (HSO−2, SO·−2) Promoted One‐Pot Efficient Synthesis of Phenyl Alkyl Selenides
Authors: Tang Ri‐Yuan , Zhong Ping , Lin Qiu‐Lian 
Published: April 2007

AbstractReduced species (HSO−2, SO·−2) promoted one‐pot synthesis of phenyl alkyl selenides has been developed. This synthetic method was achieved by reactions of diphenyl diselenide with alkyl halides at room temperature. It is noteworthy that the reactions were operated under mild reaction conditions, required short time, and got good results. A single electron transfer reaction mechanism was proposed for the reaction.
Synthesis of Antipyrine Derivatives Derived from Dimedone
Authors: Ei ashry E. S. H. , Awad L. F. , Ibrahim E. I. , Bdeewy O. Kh. 
Published: April 2007

AbstractCoupling of dimedone with the diazonium salt of 4‐aminoantipyrine afforded 2,3‐dimethyl‐4‐[2‐(5,5‐dimethyl‐ 2,6‐dioxocyclohex‐2‐ylidend)‐hydrazino]‐5‐oxo‐1‐phenylpyrazoline (3). Reaction of 3 with excess phenylhydrazine gave the mixed trishydrazone derivative 4. Treatment of 3 with hydroxylamine produced the bisoxime 5 which upon dehydrative cyclization with acetic anhydride gave the corrsponding tetrahydrobenzo[d][1,2,3]triazole derivative 7. A one‐pot synthesis of 7 was done by reacting 3 with hydroxylamine hydrochloride in pyridine, followed by heatment with acetic anhydride.
Simple partial volume transceive coils for in vivo 1H MR studies at high magnetic fields
Authors: Choi In‐Young , Lee Sang‐Pil , Garwood Michael , Ugurbil Kamil , Merkle Hellmut 
Published: April 2007

AbstractThe development of simple radiofrequency (RF) coils for magnetic resonance (MR) of the human brain is still of high interest in the engineering of systems for which phased arrays are not yet available. Particularly, high‐field MR studies will benefit from configurations with simple coils that are easy to build and require only a few RF parts for operation (e.g., quadrature hybrids). In this article we describe selected simple transmit/receive (transceive) partial volume coil assemblies for human brain studies at high magnetic fields of 3, 4, and 7 T (130, 170, and 300 MHz). To characterize coil performance, the experimental results of MRI of phantoms, anatomical MRI, and single‐voxel MRS of healthy human volunteers are presented. © 2007 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 31B: 71–85, 2007.
Maßgenaues Mauerwerk für den hochwertigen Rohbau
Authors: Schwieger Hartmut 
Published: April 2007

AbstractIm Laufe der Zeit haben sich die Anforderungen an Baustoffe und Bauteile gewandelt. Bereits an den Rohbau werden heute hohe Anforderungen gestellt, die noch vor Jahrzehnten undenkbar waren. An die Stelle von Improvisationskunst ist die durchorganisierte Baustellenlogistik getreten, die zu hoher Wirtschaftlichkeit bei gleichzeitig hoher Qualität führt.Insbesondere Immobilienmakler und Bauträger wissen, welche Wirkung ein ordentlicher Rohbau und eine saubere Baustelle auf potenzielle Käufer und Nutzer haben. Die Erstbesichtigung während der Rohbauphase ist dabei ein entscheidendes Mittel der Vertrauensbildung. Eine aufgeräumte Baustelle, bei der offensichtlich die Bauunternehmer ihr Handwerk verstehen, bestärken Käufer und Nutzer in der Entscheidung für Bauwerk, Baustoff und Bauausführende. Im Gegensatz dazu hat eine unsaubere Baustelle mit schlampiger Verarbeitung zur Folge, dass die Käufer und zukünftigen Nutzer ihre Entscheidung in Frage stellen, weil Zweifel an der Qualität der Ausführung aufkommen. Der Zustand des Rohbaus kann daher die Entscheidung des Erwerbers/Nutzers maßgeblich beeinflussen und/oder bestätigen.
Semidiscrete formulations for transient transport at small time steps
Authors: Harari Isaac , Hauke Guillermo 
Published: April 2007

AbstractSolutions of direct time‐integration schemes for transient advection–diffusion–reaction problems that converge in time to conventional semidiscrete formulations may be polluted at small time steps by spurious spatial oscillations. This degradation is not an artifact of the time‐marching scheme, but rather a property of the solution of the semidiscrete Galerkin approximation itself. An analogy to steady advection–diffusion–reaction problems with a modified reaction coefficient by the Rothe method of discretizing in time prior to spatial discretization provides an upper bound on the time step for the onset of spatial instability. Spatial stabilization removes this pathology, leading to stabilized implicit time‐integration schemes that are free of spurious oscillations at small time steps. Copyright © 2007 John Wiley & Sons, Ltd.
A simple axisymmetric extension to virtual cell embedding
Authors: Tang J. 
Published: April 2007

AbstractVirtual cell embedding (VCE) is a simple cartesian gridding method that subdivides cells into discrete subcells to obtain the approximate obstructed cell area and side lengths. It can be used to make a very fast calculation method for the Euler equations in two dimensions. However, the original procedure for two spatial dimensions is inadequate for axisymmetric geometries, where radial co‐ordinates of cells and interfaces need to be known. Presented in this paper is a short, simple extension of the VCE method to handle axisymmetric cases with an accuracy consistent with the basic VCE surface representation in planar geometries. The method will be tested in basic conical flow simulations to show its usefulness for practical engineering design purposes. Copyright © 2007 John Wiley & Sons, Ltd.
Epigenetic silencing of the candidate tumor suppressor gene PROX1 in sporadic breast cancer
Authors: Versmold Beatrix , Felsberg Jörg , Mikeska Thomas , Ehrentraut Denise , Köhler Juliane , Hampl Juergen A. , Röhn Gabriele , Niederacher Dieter , Betz Beate , Hellmich Martin , Pietsch Torsten , Schmutzler Rita K. , Waha Andreas 
Published: April 2007

AbstractExtensive hypermethylation and consecutive transcriptional silencing of tumorsuppressor genes have been documented in multiple tumor entities including breast cancer. In a microarray based genome‐wide methylation analysis of five sporadic breast carcinomas we identified a hypermethylated CpG island within the first intron of the prospero related homeobox gene 1 (PROX1). We, therefore, investigated CpG island methylation of PROX1 in a series of 33 pairs of primary breast cancer and corresponding normal tissue samples by bisulfite sequencing and COBRA analyses. Seventeen of these (52%) breast cancer samples revealed a significant accumulation of methylated CpG sites along with a significant reduction of PROX1 transcription compared to normal breast tissues of the same patients. Frequent methylation was also observed in brain metastases from primary breast cancer (21/37 = 57% of cases). Secondary, we analysed 38 brain metastases of primary breast carcinomas and detected a significantly reduced expression of PROX1 compared to normal breast tissue (p < 0.001) and primary breast carcinomas (p < 0.05), respectively. Additionally, treatment of breast cancer cell lines with demethylating agents could reactivate PROX1 transcription. In summary, we have identified PROX1 as a novel target gene that is hypermethylated and transcriptionally silenced in primary and metastatic breast cancer. © 2007 Wiley‐Liss, Inc.
Expression of oncofetal RNA‐binding protein CRD‐BP/IMP1 predicts clinical outcome in colon cancer
Authors: Dimitriadis Euthymios , Trangas Theoni , Milatos Stavros , Foukas Periklis G. , Gioulbasanis Ioannis , Courtis Nelly , Nielsen Finn C. , Pandis Nikos , Dafni Urania , Bardi Georgia , Ioannidis Panayotis 
Published: April 2007

AbstractThe oncofetal CRD‐BP/IMP1 RNA binding protein regulates posttranscriptionally a handful of RNA transcripts, implicated in cell adhesion and invadopodia formation and was recently identified as a target of the β‐catenin/Tcf transcription factor that is constitutively activated in colorectal carcinomas (CRCs). The expression of CRD‐BP/IMP1 was studied in normal adult intestines and CRCs. In normal mucosa, CRD‐BP/IMP1 immunoreactivity was observed in few scattered cells located predominantly at or near the bottom of the crypts, whereas in CRCs the protein was detectable in tumor cells of 50% of the specimens analyzed. CRD‐BP/IMP1 mRNA expression was measured by qRT‐PCR in 78 CRCs. Thirty‐two (41%) of the specimens were negative or had negligible expression, whereas the remaining forty‐six (59%) expressed a wide range of CRD‐BP/IMP1 mRNA levels. CRD‐BP/IMP1 mRNA expression correlated with that of the putative stem/progenitor cell marker Musashi‐1 mRNA (p = 0. 035). CRD‐BP/IMP1 positive tumors metastasized and/or recurred more frequently (p = 0.001) and its expression defined a group of patients with shorter survival (p = 0.014). Furthermore, in a multivariate analysis CRD‐BP/IMP1 expression was found to be an independent predictor of survival (p = 0.015). For stage I & II patients, the differences in metastasis/recurrence and survival rates remained significant (p = 0.001 and 0.033, respectively). These findings indicate that CRD‐BP/IMP1 positive tumors exhibit early disease dissemination and unfavorable prognosis. © 2007 Wiley‐Liss, Inc.
Chitosan monomer accelerates alkaline phosphatase activity on human osteoblastic cells under hypofunctional conditions
Authors: Yamada Shizuka , Ganno Tomoko , Ohara Naoko , Hayashi Yoshihiko 
Published: April 2007

AbstractChitosan is a natural polyaminosaccharide that is extensively applied as an antitumor and antirheumatic drug. However, there are few reports about its effects on hypofunctional osteoblasts in vitro. We investigated the biological characteristics of a human osteoblastic cell line (NOS‐1 cells) that was cultured with a chitosan monomer‐containing medium under simulated microgravity conditions. After 7 days of cell incubation under the conventional conditions, the flasks were transferred to a microgravity simulator for 3 days. In the 0.005% chitosan monomer supplemented group, the marker enzyme of biological mineralization, the alkaline phosphatase (ALP) activity, was significantly higher compared with the control group (p < 0.05). A cDNA microarray was performed to investigate the effects on the mRNA level by chitosan monomer, and the fluorescent signal was analyzed. The interferon gamma (IFN‐γ) receptor gene was detected with a signal ration of 2.2. The slight increase of IFN‐γ receptor expression was confirmed after 3 days of incubation according to RT‐PCR analysis. Western blot analysis also showed the increased expression of IFN‐γ receptor. These results suggest that a supra‐low concentration of chitosan monomer may increase the ALP activity of osteoblastic cells through the IFN‐γ receptor at the early phase of cell culture and recover the activity for biological mineralization under the hypofunctional condition. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2007
Antibiotic‐containing collagen for the treatment of bone defects
Authors: Rupprecht Stephan , Petrovic Ljubinko , Burchhardt Bettina , Wiltfang Jörg , Neukam Friedrich Wilhelm , Schlegel Karl Andreas 
Published: April 2007

AbstractRecent studies have explored the use of biodegradable implants that incorporate antibiotics for the treatment of bone infections. In this study, a biodegradable composite containing bovine collagen and teicoplanin (Targobone®) was used for the treatment of mandibular nonunion defects. Patients with mandibular nonunion defects subsequent to osteosynthesis were treated with Targobone® (n = 9) or with autologous bone grafts (n = 12). Clinical and radiological evaluations were performed preoperatively, immediately postoperatively, and 4 and 24 weeks postoperatively. Bone regeneration was defined relative to the original defect area in the panoramic radiograph by using image analysis software. In the Targobone® group, the defect area decreased to 78% (SD ± 21.8%) of the preoperative area within 4 weeks and to 21% (SD ± 9.7%) of the preoperative area within 24 weeks. In the autologous bone graft group, the defect area decreased to 69% (SD ± 32.4%) of the preoperative area within 4 weeks and to 4.7% (SD ± 5.6%) of the preoperative area within 24 weeks. Thus, Targobone® is a promising option for the treatment of bone defects. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Towards a functional radiopaque hydrogel for nucleus pulposus replacement
Authors: Boelen Erik J. H. , Koole Leo H. , van Rhijn Lodewijk W. , van Hooy‐Corstjens Catharina S. J. 
Published: April 2007

AbstractPatients with severe back pain, attributed to a herniation of the nucleus pulposus of the intervertebral disc, can benefit from a replacement of only the nucleus pulposus, provided the annulus fibrosus is still functional. This study investigated four intrinsically radiopaque hydrogel biomaterials, which were designed specifically to replace the herniated nucleus pulposus. The important characteristic of these hydrogels is that they can be visualized entirely with both MRI and X‐rays. The materials are based on copolymers of N‐vinyl‐2‐pyrrolidinone (NVP) or 2‐hydroxyethyl methacrylate (HEMA) and a radiopacity introducing monomer, 2‐(4′‐iodobenzoyl)‐oxo‐ethyl methacrylate (4IEMA). Two of the formulations also contain the chemical crosslinker allyl methacrylate (AMA). Physical–mechanical properties like the water‐uptake, biocompatibility, stiffness, and fatigue and creep behavior were studied, while keeping an eye on the intended application. All four materials were designed with 5–6 mass % of iodine to ensure sufficient X‐ray visibility between two vertebrae. It was found that the materials display appropriate stiffness and biocompatibility. The crosslinked materials hold most promise as a functional nucleus prosthesis, as they combine these properties also with high water content, fatigue resistance, and recovery after loading. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Comparative in vitro biomechanical evaluation of two soft tissue defect products
Authors: Johnson Wesley , Inamasu Joji , Yantzer Brenda , Papangelou Christopher , Guiot Bernard 
Published: April 2007

AbstractA soft tissue defect is often an unavoidable consequence of various surgical procedures or a result of trauma. Recently, intraoperative use of xenograft as a patch to the soft tissue defect has become popular with various products available in the market. In this study, mechanical properties of the OrthADAPT™ Bioimplants (Pegasus Biologics, Irvine, CA), new xenograft products composed of collagen from equine pericardium, were evaluated individually and against an existing bioimplant product. The OrthADAPT™ Bioimplants have three subtypes which differ in the degree of crosslinking of collagen strands. The three products are named as FX, PX, and MX in the order of the degree of collagen crosslinking and likely durability in vivo, with FX most dense in crosslinking and hence most durable. The three subtypes underwent three destructive mechanical tests: tensile strength, suture pull‐out strength, and burst strength test. In tensile strength and suture pull‐out strength tests, the three products were compared with CuffPatch™, a similar collagen‐based xenograft product from a competing manufacturer. In the burst strength test, the three products were compared with untreated equine pericardium tissue. In tensile strength and suture pull‐out strength tests, the products FX and MX were shown to have mechanical properties that were comparable with CuffPatch, while the mechanical strength of PX was significantly inferior to FX and CuffPatch in tensile strength test. In burst strength test, there were no differences in mechanical properties among the three OrthADAPT Bioimplants. This study demonstrates the biomechanical equivalence of OrthADAPT with CuffPatch. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2007
Increased tolerance and conversion of inhibitors in lignocellulosic hydrolysates by Saccharomyces cerevisiae
Authors: Almeida João RM , Modig Tobias , Petersson Anneli , Hähn‐Hägerdal Bärbel , Lidén Gunnar , Gorwa‐Grauslund Marie F 
Published: April 2007

AbstractDuring hydrolysis of lignocellulosic biomass, monomeric sugars and a broad range of inhibitory compounds are formed and released. These inhibitors, which can be organized around three main groups, furans, weak acids and phenolics, reduce ethanol yield and productivity by affecting the microorganism performance during the fermentation step. Among the microorganisms that have been evaluated for lignocellulosic hydrolysate ethanol fermentation, the yeast Saccharomyces cerevisiae appears to be the least sensitive. In order to overcome the effect of inhibitors, strategies that include improvement of natural tolerance of microorganism and use of fermentation control strategies have been developed. An overview of the origin, effects and mechanisms of action of known inhibitors on S. cerevisiae is given. Fermentation control strategies as well as metabolic, genetic and evolutionary engineering strategies to obtain S. cerevisiae strains with improved tolerance are discussed. Copyright © 2007 Society of Chemical Industry