bluuebunny/crossref_metadata_2025 huggingface dataset:
Feature‐based vector simulation of water waves
Authors: Yu Qizhi , Neyret Fabrice , Steed Anthony
Published: April 2011

We present a method for simulating local water waves caused by obstacles in water streams for real‐time graphics applications. Given a low‐resolution water surface and velocity field, our method is able to decorate the input water surface with high resolution detail for the animated waves around obstacles. We construct and animate a vector representation of the waves. It is then converted to feature‐aligned meshes for capturing the surfaces of the waves. Results demonstrate that our method has the benefits of real‐time performance and easy controllability. The method also fits well into a state‐of‐the‐art river animation system. Copyright © 2011 John Wiley & Sons, Ltd.
Efficient wavelet‐based geometry compression
Authors: Zhao Chong , Sun Hanqiu , Qin Kaihuai
Published: April 2011

In recent years, some wavelets constructed via local lifting have been proposed to accelerate the compression of geometric models. Unlike the traditional wavelet‐based compression with global optimisation, their compression ratios are still not sufficient, particularly at low‐bit rates. In this paper, we present a novel efficient wavelet‐based compression approach using the matrix‐valued Loop subdivision on triangular meshes. Based on the local lifting scheme, the computation of the wavelet transform is highly efficient and requires low memory usage. With the shape controls introduced by the matrix‐valued subdivision, our approach can greatly improve the fitting quality of surfaces while keeping the efficient data compression. The experimental results showed that our wavelet transform had better performance on balancing the efficiency and compression ratios. Copyright © 2011 John Wiley & Sons, Ltd.
Strategies and Perspectives in Ion‐Channel Engineering
Authors: Grosse Wolfgang , Essen Lars‐Oliver , Koert Ulrich
Published: April 2011

Membranes form natural barriers that need to be permeable to diverse matter like ions and substrates. This permeability is controlled by ion‐channel proteins, which have attracted great interest for pharmaceutical applications. Ion‐channel engineering (ICE) modifies biological ion channels by chemical/biological synthetis means. The goal is to obtain ion channels with modified or novel functionality. Three functional strategies exist. The first is the manipulation of the wider pores with robust β‐barrel structures, such as those of α‐hemolysin and porins. The second engineering approach focuses on the modification of narrow (mostly α‐helical) pores to understand selectivity and modes of action. A third functional approach addresses channel gating by (photo)triggering the biological receptor that controls the channel. Several synthetis strategies have been developed and successfully utilized for the synthetic modification of biological ion‐channels: the S‐alkylation of specifically introduced Cys, protein semisynthesis by native chemical ligation, protein semisynthesis by protein trans‐splicing, as well as nonsense‐suppression methods. Structural studies (X‐ray crystallography, NMR spectroscopy) are necessary to support the functional studies and to afford predictable engineering. The reprogramming and re‐engineering of channels can be used for sensing applications, treatment of channelopathies, chemical neurobiology, and providing novel lead compounds for targeting ion channels.
Low‐Valent Molybdenum‐Based Dual Pre‐Catalysts for Highly Efficient Catalytic Epoxidation of Alkenes and Deoxygenation of Sulfoxides
Authors: Krackl Sebastian , Company Anna , Enthaler Stephan , Driess Matthias
Published: April 2011

A variety of homoleptic and heteroleptic, triply bonded dimolybdenum hexaalkoxides, [(Mo2(OR)6] and [Mo2(OR)4(OR′)2], were successfully applied as dual pre‐catalysts in both, the epoxidation of olefins with tert‐butyl hydroperoxide and the deoxygenation of diorganosulfoxides with silanes, to form the corresponding sulfides. In the epoxidation of cyclooctene, the pre‐catalysts demonstrated an intriguingly high activity, with turnover frequencies (TOFs) of above 60 000 h−1 at elevated temperatures (≈50 °C) and even very high activity at room temperature. Furthermore, using [Mo2(OtBu)6] as a pre‐catalyst, we studied the effect of the solvent and we extended the epoxidation reaction to more demanding olefins, which revealed a particularly high activity even towards primary alkenes. In addition, the same pre‐catalysts, in comparison to previously reported Mo‐based systems, exhibited excellent activities for the deoxygenation of phenyl methyl sulfoxide to thioanisole in the presence of silanes (TOFs>160 h−1). A number of other diorganosulfoxides were used in the catalytic deoxygenation to investigate the scope and limitations of the system, displaying an excellent performance for differently substituted substrates.
Aging and Thermal Stability of the Mixed Product of the Ether‐Soluble Fraction of Bio‐Oil and Bio‐Diesel
Authors: Jiang X. , Zhong Z. , Ellis N. , Wang Q.
Published: April 2011

The storage and thermal stability of blends of the ether‐soluble fraction of bio‐oil (ES) and bio‐diesel are reported. Fuel properties such as viscosity, water content, acid number and average molecular weight of the ES/bio‐diesel blends were measured before and after aging. Compared to the aging properties of bio‐oil alone, very small changes in water content and viscosity were shown for the blends aged at 80 °C for 180 h. Chemical changes were characterized using gel permeation chromatography, showing a slight increase in the molecular weight over time. Further confirmation of the changes was provided through Fourier transform infrared spectrometry, thermal decomposition analysis using a thermogravimetric analyzer, proton assignment using proton nuclear magnetic resonance, and carbon assignment using carbon nuclear magnetic resonance. Overall, the study indicates that ES/bio‐diesel blends are stable as fuel under the conditions tested in this paper.
Oxidation of Phenol by Microbubble‐Assisted Microelectrolysis
Authors: Ren Y. , Wu Z. , Ondruschka B. , Braeutigam P. , Franke M. , Nehring H. , Hampel U.
Published: April 2011

The degradation of phenol under microelectrolysis was enhanced by O2‐microbubbles. Phenol solution was circled in a microbubble‐assisted microelectrolysis reactor under acid conditions. The degradation rate of phenol reached 65 % within 2 h with O2‐microbubbles, compared to 9.5 % and 4 % with air‐ and N2‐microbubbles due to better dissolution of oxygen with finer microbubbles and at higher dissolution pressure. Higher efficiencies of phenol degradation at lower temperature further confirm the role of dissolved oxygen. In the microbubble‐assisted microelectrolysis system dissolved oxygen, carbon steel pellets, and sulfuric acid are necessary conditions for the oxidation of phenol. The conversion of phenol increases with an increasing amount of carbon steel pellets and/or sulfuric acid. Catechol, hydroquinone, and low‐molecular‐weight carboxylic acids are the major products.
Aggregation and Layering Transitions in Thin Films of X‐, T‐, and Anchor‐Shaped Bolaamphiphiles at the Air–Water Interface
Authors: Nitoń Patrycja , Żywociński Andrzej , Paczesny Jan , Fiałkowski Marcin , Hołyst Robert , Glettner Benjamin , Kieffer Robert , Tschierske Carsten , Pociecha Damian , Górecka Ewa
Published: April 2011

Aggregation in Langmuir films is usually understood as being a disorderly grouping of molecules turning into chaotic three‐dimensional aggregates and is considered an unwanted phenomenon causing irreversible changes. In this work we present the studies of 11 compounds from the group of specific surfactants, known as bolaamphiphiles, that exhibit reversible aggregation and, in many cases, transition to well‐defined multilayers, which can be considered as a layering transition. These bolaamphiphiles incorporate rigid π‐conjugated aromatics as hydrophobic cores, glycerol‐based polar groups and hydrophobic lateral chains. Molecules of different shapes (X‐, T‐, and anchor) were studied and compared. The key property of these compounds is the partial fluorination of the lateral chains linked to the rigid cores of the molecules. The most interesting feature of the compounds is that, depending on their shape and degree of fluorination, they are able to resist aggregation and preserve a monolayer structure up to relatively high surface pressures (T‐shaped and some X‐shaped molecules), or create well‐defined trilayers (X‐ and anchor‐shaped molecules). Experimental studies were performed using Langmuir balance, surface potential and X‐ray reflectivity measurements.
Application of L‐proline derivatives as chiral shift reagents for enantiomeric recognition of carboxylic acids
Authors: Naziroglu Hayriye Nevin , Durmaz Mustafa , Bozkurt Selahattin , Sirit Abdulkadir
Published: April 2011

Four proline‐derived chiral receptors 5, 6, 7, 8 were readily synthesized starting from L‐proline. The enantiomeric recognition ability of chiral receptors was examined with a series of carboxylic acids by 1H NMR spectroscopy. The molar ratio and the association constants of the chiral compounds with each of the enantiomers of guest molecules were determined by using Job plots and a nonlinear least‐squares fitting method, respectively. The Job plots indicate that the hosts form 1:1 instantaneous complexes with all guests. The receptors exhibited different chiral recognition abilities toward the enantiomers of racemic guests. Among the chiral receptors used in this study, prolinamide 6 was found to be the best chiral shift reagent and is effective for the determination of the enantiomeric excess of chiral carboxylic acids. Chirality, 2011. © 2011 Wiley‐Liss, Inc.
Magnetic and Luminescent Properties of Sm, Eu, Tb, and Dy Coordination Polymers with 2‐Hydroxynicotinic Acid
Authors: Xu Na , Wang Chao , Shi Wei , Yan Shi‐Ping , Cheng Peng , Liao Dai‐Zheng
Published: April 2011

By using multidentate ligand 2‐hydroxynicotinic acid (H2nica), six new lanthanide coordination polymers [Sm(Hnica)(H2O)2SO4]n (1), {[Sm3(Hnica)6(H2O)6(OH)]·3H2O·SO4}n (2), [Eu(Hnica)(H2O)2SO4]n (3), {[Eu3(Hnica)6(H2O)6(OH)]·6H2O·SO4}n (4), {[Tb(Hnica)2(H2O)2]ClO4·H2O}n (5), and {[Dy(Hnica)2(H2O)2]ClO4·H2O}n (6) were synthesized and characterized by elemental analysis, IR spectra, and X‐ray single‐crystal diffraction. Compounds 1 and 3 exhibit a 1D Ln–O–Ln chain structure. Compounds 2 and 4 show a 2D Kagomé lattice structure, whereas 5 and 6 display a 2D rhombic grid structure. The luminescent properties of 1–6 at room temperature were studied. Direct‐current (dc) magnetic susceptibility studies reveal antiferromagnetic interactions between LnIII ions in 1–6, and alternating‐current (ac) magnetic susceptibility data of 6 suggests frequency‐dependent out‐of‐phase signals below 5 K.
Enantioselective Access to Key Intermediates for Salvinorin A and Analogues
Authors: Lanfranchi Don Antoine , Bour Christophe , Hanquet Gilles
Published: April 2011

Access to enantiopure synthetic platforms that can generate key intermediates for salvinorin A analogues through diastereoselective Diels–Alder cycloaddition between an enantiopure sulfinylquinone and semicyclic dienes is described.
Pharmacologic downregulation of c‐FLIPL restores juxtacrine death receptor‐mediated apoptosis in cancer cells in a peritoneal carcinomatosis model
Authors: Shen Yi , Herde Ryan , Doxey Brett W. , Xu Changxin , Gray Phillip D. , Kuwada Scott K.
Published: April 2011

Metastasis occurs when circulating cancer cells implant in normal secondary tissues. Paradoxically, many cancer cells express death receptors while many normal tissues express the cognate death receptor ligands, suggesting that cancer cells possess mechanisms to inhibit death receptor signaling. Pharmacological restoration of juxtacrine‐mediated death receptor signaling could prevent cancer cells from implanting in normal tissues such as the peritoneum. The results showed that BAY 11‐7085 significantly inhibited peritoneal carcinomatosis in mice following the introduction of colon and pancreatic cancer cell lines into the intra‐abdominal cavity. Treatment with BAY 11‐7085 restored juxtacrine death receptor signaling during the adhesion of the cancer cells to mesothelial cells, which line the peritoneum. BAY 11‐7085 rapidly inhibited c‐FLIPL expression in colon and pancreatic cancer cell lines during adhesion to mesothelial cells. Pancreatic cancer cells sorted for high c‐FLIPL expression formed peritoneal implants much more readily than cells with low c‐FLIPL expression, and RNAi inhibition of c‐FLIPL in colon cancer cells dramatically reduced peritoneal implantation. This is a novel demonstration that the restoration of death receptor‐mediated apoptotic signaling in cancer cells through the pharmacological inhibition of c‐FLIPL can inhibit tumor implantation in a clinically relevant model of peritoneal carcinomatosis, a fatal disease. Pharmacological inhibitors of FLIP hold promise as a way to curtail cancer cell colonization of secondary tissues.
Inhibition of CXCR4/CXCL12 signaling axis by ursolic acid leads to suppression of metastasis in transgenic adenocarcinoma of mouse prostate model
Authors: Shanmugam Muthu K. , Manu Kanjoormana A. , Ong Tina H. , Ramachandran Lalitha , Surana Rohit , Bist Pradeep , Lim Lina H.K , Prem Kumar Alan , Hui Kam M. , Sethi Gautam
Published: April 2011

Increasing evidences indicate that CXCR4/CXCL12 signaling pathway plays a pivotal role in the process of distant site metastasis that accounts for more than 90% of prostate cancer related deaths in patients. Thus, novel drugs that can downregulate CXCR4/CXCL12 axis have a great potential in the treatment of metastatic prostate cancer. In this report, we tested an agent, ursolic acid (UA) for its ability to modulate CXCR4 expression in prostate cancer cell lines and inhibit metastasis in vivo in transgenic adenocarcinoma of mouse prostate (TRAMP) model. We observed that UA downregulated the expression of CXCR4 in prostate cancer cells irrespective of their HER2 status in a dose‐ and time‐dependent manner. Neither proteasome inhibitor nor lysosomal stabilization had any effect on UA‐induced decrease in CXCR4 expression. When investigated for the molecular mechanisms, it was observed that the downregulation of CXCR4 was due to transcriptional regulation as indicated by downregulation of mRNA expression, inhibition of NF‐κB activation and modulation of chromatin immunoprecipitation activity. Suppression of CXCR4 expression by UA further correlated with the inhibition of CXCL12‐induced migration and invasion in prostate cancer cells. Finally, we also found that UA treatment can inhibit metastasis of prostate cancer to distal organs, including lung and liver and suppress CXCR4 expression levels in the prostate tissues of TRAMP mice. Overall, our experimental findings suggest that UA exerts its antimetastatic effects through the suppression of CXCR4 expression in prostate cancer both in vitro and in vivo.
Cytochrome P4501A2 phenotype and bladder cancer risk: The Shanghai bladder cancer study
Authors: Tao Li , Xiang Yong‐Bing , Chan Kenneth K. , Wang Renwei , Gao Yu‐Tang , Yu Mimi C. , Yuan Jian‐Min
Published: April 2011

Cytochrome P450 1A2 (CYP1A2) is hypothesized to catalyze the activation of arylamines, known human bladder carcinogens present in cigarette smoke. The relationship between CYP1A2 phenotype and bladder cancer risk was examined in a case‐control study involving 519 patients and 514 controls in Shanghai, China. Both CYP1A2 and N‐acetyltransferase 2 (NAT2) phenotypic status were determined by a caffeine‐based urinary assay. Our study showed that among smokers at urine collection, patients with bladder cancer had statistically significantly higher CYP1A2 phenotype scores compared to control subjects (p = 0.001). The odds ratios (95% confidence intervals) of bladder cancer for the second, third and fourth quartiles of the CYP1A2 score were 1.31 (0.53–3.28), 2.04 (0.90–4.60) and 2.82 (1.32–6.05), respectively, relative to the lowest quartile (p for trend = 0.003). NAT2 slow acetylation phenotype was associated with a statistically significant 40% increased risk of bladder cancer, and the relationship was independent of subjects' smoking status. Subjects possessing the NAT2 slow acetylation phenotype and the highest tertile of CYP1A2 scores showed the highest risk for bladder cancer. Their odds ratios (95% confidence intervals) was 2.13 (1.24–3.68) relative to their counterparts possessing the NAT2 rapid acetylation phenotype and the lowest tertile of CYP1A2 scores. The findings of our study demonstrate that CYP1A2 phenotype may be an important contributing factor in the development of smoking‐related bladder cancer in humans.
Novel Supramolecular Hosts Based on Linear and Cyclic Oligomers of Glycoluril
Authors: Stancl Marek , Svec Jan , Sindelar Vladimir
Published: April 2011

We report here on supramolecular objects containing glycoluril units and functioning as host molecules. The present paper contains a detailed discussion on the synthetic approaches leading to methylene bridged glycoluril oligomers, as well as a description of their supramolecular properties. We also discuss the recently obtained macrocycle, bambus[6]uril, and its affinity towards anions.
Protective effects of gallic acid on hepatic lipid peroxide metabolism, glycoprotein components and lipids in streptozotocin‐induced type II diabetic wistar rats
Authors: Punithavathi V. R. , Stanely Mainzen Prince P. , Kumar M. R. , Selvakumari C. J.
Published: April 2011

We evaluated the protective effects of gallic acid (3,4,5‐trihydroxybenzoic acid) on hepatic lipid peroxidation products, antioxidants, glycoprotein components, and lipids in streptozotocin‐induced type II diabetic rats. To induce type II diabetes, rats were injected with streptozotocin intraperitoneally at a single dose of 40 mg/kg. Gallic acid (10 and 20 mg/kg) treatment was given to diabetic rats orally using an intragastric tube daily for 21 days. Streptozotocin‐induced diabetic rats showed a significant increase in the levels of blood glucose, hepatic lipid peroxidation products, glycoprotein components, lipids, and the activity of HMG‐CoA reductase and a significant decrease in the levels of plasma insulin and liver glycogen. In addition to this, the activities/levels of hepatic antioxidants were decreased in diabetic rats. Gallic acid (10 and 20 mg/kg) treatment showed significant protective effects on all the biochemical parameters studied in diabetic rats. Thus, our study shows the antihyperglycemic, antilipid peroxidative, antioxidant, and antilipidemic effects of gallic acid in streptozotocin‐induced type II diabetic rats. A diet containing gallic acid may be beneficial to type II diabetic patients. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 25:68–76 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/jbt.20360
Differential carbohydrate binding and cell surface glycosylation of human cancer cell lines
Authors: Arndt Nadia X. , Tiralongo Joe , Madge Paul D. , von Itzstein Mark , Day Christopher J.
Published: April 2011

Currently there is only a modest level knowledge of the glycosylation status of immortalised cell lines that are commonly used in cancer biology as well as their binding affinities to different glycan structures. Through use of glycan and lectin microarray technology, this study has endeavoured to define the different bindings of cell surface carbohydrate structures to glycan‐binding lectins. The screening of breast cancer MDA‐MB435 cells, cervical cancer HeLa cells and colon cancer Caco‐2, HCT116 and HCT116–FM6 cells was conducted to determine their differential bindings to a variety of glycan and lectin structures printed on the array slides. An inverse relationship between the number of glycan structures recognised and the variety of cell surface glycosylation was observed. Of the cell lines tested, it was found that four bound to sialylated structures in initial screening. Secondary screening in the presence of a neuraminidase inhibitor (4‐deoxy‐4‐guanidino‐Neu5Ac2en) significantly reduced sialic acid binding. The array technology has proven to be useful in determining the glycosylation signatures of various cell‐lines as well as their glycan binding preferences. The findings of this study provide the groundwork for further investigation into the numerous glycan–lectin interactions that are exhibited by immortalised cell lines. J. Cell. Biochem. 112: 2230–2240, 2011. © 2011 Wiley‐Liss, Inc.
A simple, diversity oriented synthesis of highly substituted pyridines
Authors: Kaczanowska Katarzyna , Eickhoff Holger , Albert Klaus , Wiesmüller Karl‐Heinz , Schaffner Arnaud‐Pierre
Published: April 2011

A particularly straightforward and efficient protocol for the synthesis of highly substituted pyridines, based on a condensation reaction of β‐aminocrotonitrile and easily accessible (E)‐2‐oxo‐4‐aryl‐but‐3‐enoic acids and (E)‐4‐oxo‐4‐aryl‐but‐2‐enoic acids is described. J. Heterocyclic Chem., (2011).
Expression of myelin genes: Comparative analysis of Oli‐neu and N20.1 oligodendroglial cell lines
Authors: Pereira Glauber B. , Dobretsova Anna , Hamdan Hamdan , Wight Patricia A.
Published: April 2011

The use of immortalized cells has been instrumental as a tool with which to study gene regulation. However, it is crucial to understand the status of a given cell line, especially when investigating the regulation of genes whose expression is developmentally regulated. Several immortalized cell lines have been derived from primary cultures of mouse oligodendrocytes. Two such cell lines, N20.1 and Oli‐neu, were characterized here in terms of their relative expression of myelin genes at both the mRNA level and the protein level. Analysis of the splice isoforms expressed by the myelin proteolipid protein (Plp1), myelin basic protein (Mbp), and 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (Cnp) genes, along with the relative amount of protein expressed by these genes, suggests that the cell lines are representative of immature oligodendrocytes, although Oli‐neu cells appear to be farther along the differentiation pathway compared with N20.1 cells. Previous studies have shown that the developmental increase in Plp1 gene expression that occurs during the active myelination period is governed by transcription regulatory elements present within the first intron. The responsiveness of one of these elements, the so‐called antisilencer/enhancer (ASE), was investigated in both cell lines. Results presented here suggest that the ASE has a much more potent effect in Oli‐neu cells. Thus, the two cell lines appear to be at different stages and will be useful as a means to study transcription regulatory elements whose influence changes during development. © 2011 Wiley‐Liss, Inc.
Phosphorus leaching in a calcareous soil treated with plant residues and inorganic fertilizer
Authors: Jalali Mohsen , Karamnejad Ladan
Published: April 2011

Column experiments were conducted over 45 d to determine the degree of P mobility. The sandy loam soil was spiked with 200 mg P kg–1 and 5% organic residues. The treatments included: control without any water‐soluble P and plant residues, potato, wheat, water‐soluble P fertilizer, wheat + water‐soluble P, and potato + water‐soluble P. Each column was leached with distilled water, and leachates were collected and analyzed for P, K+, Ca2+, Mg2+, along with pH and EC. Sequential extraction was performed on soil samples at the end of leaching column experiments. The relatively high initial concentration of P in the leachates decreased to more stable values after 15 d which can be attributed to the colloid‐bound P. The P concentrations in the leachates fluctuated between 8 and 220 mg L–1 in the water‐soluble–P fertilizer treatment, between 0.80 and 230 mg L–1 in the potato + water‐soluble‐P treatment, and between 0.90 and 214 mg L–1 in the wheat + water‐soluble P treatment. Leaching loss of P mainly occurred in the 15 d of leaching, accounting for 94%, 88%, and 65% of total P leached in wheat + water‐soluble‐P, potato + water‐soluble‐P, and water‐soluble‐P treatments, respectively. Maximum amount of P leached was found from an exponential kind model and was in the range 0.45 mg kg–1 to 125.4 mg kg–1 in control and potato + water‐soluble‐P treatments, respectively. Sequential extraction results showed that in control and amended soils the major proportion of P was associated with Ca. The leachate samples in all treatments were saturated with respect to hydroxyapatite, β‐tricalcium phosphate, and octacalcium phosphate up to 20 d of leaching, whereas they were undersaturated with respect to Mg‐P minerals through the entire leaching experiment.
Macromol. React. Eng. 2/2008
Authors: Sumino Ken‐Ichi , Taniike Toshiaki , Terano Minoru , George Graeme A.
Published: April 2011

Cover: Photo‐ and thermal stabilities of poly(propylene) (PP)/SiO2 nanocomposites with various sizes of the SiO2 nanoparticles were studied. The cover picture points out that both, decreasing the particle size of SiO2 and lowering the quenching temperature in making the sample films improved the stability of the nanocomposites. The results strongly suggested that smaller spherulite sizes lead to higher stability of the nanocomposites. Further details can be found in the article by K.‐I. Sumino, T. Taniike, M. Terano,* and G. A. George on page 135.
Subtracting a best rank‐1 approximation from p × p × 2(p≥2) tensors
Authors: Kong Xu , Jiang Yao‐Lin
Published: April 2011

We introduce one special form of the ptimesp × 2 (p≥2) tensors by multilinear orthonormal transformations, and present some interesting properties of the special form. Through discussing on the special form, we provide a solution to one conjecture proposed by Stegeman and Comon in a conference paper (Proceedings of the EUSIPCO 2009 Conference, Glasgow, Scotland, 2009), and reveal an important conclusion about subtracting a best rank‐1 approximations from p × p × 2 tensors of the special form. All of these confirm that consecutively subtracting the best rank‐1 approximations may not lead to a best low rank approximation of a tensor. Numerical examples show the correctness of our theory. Copyright © 2011 John Wiley & Sons, Ltd.
An optimal‐order error estimate for a Galerkin‐mixed finite‐element time‐stepping procedure for porous media flows
Authors: Chen Feng‐xin , Chen Huan‐zhen , Wang Hong
Published: April 2011

This article deals with the numerical approximation of miscible displacement problem of one incompressible fluid in a porous medium. The adopted formulation is based on the combined use of a mixed finite‐element scheme to treat pressure equation and of the finite‐element approach to treat concentration equation. Optimal‐order error estimates are obtained under some milder mesh‐parameter constraints. © 2011 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 28: 707–719, 2012
When a cigar is not just a cigar: Alternative takes on data and data analysis
Authors: Sandelowski Margarete
Published: April 2011

A commonplace in the qualitative research literature is that data can be interpreted in more than one way. Less commonly considered are how much the interpretive flexibility of data depends on the adequacy of researchers' interpretive repertoires and how it troubles the lines conventionally drawn between methods, primary and secondary analysis, and between valid and invalid interpretation. What largely differentiates inquiry is not whether it is qualitative or quantitative but rather the attitude taken toward the data generated in a study. The more varied the interpretive repertoire of researchers, the greater will be their capacity to be tuned in to and credibly account for the varied ways in which data can be seen and treated. © 2011 Wiley Periodicals, Inc. Res Nurs Health 34:342–352, 2011
Realizing porphyrin‐functionalization of crosslinked polystyrene microspheres via two special polymer reactions
Authors: Gao Baojiao , Chen Yingjun , Lei Qingjuan
Published: April 2011

A novel route to make crosslinked polystyrene (CPS) microspheres to be porphyrin‐functionalized via two special polymer reactions, Kornblum reaction and Adler reaction, was designed and founded. The chloromethyl groups of chloromethylated crosslinked polystyrene (CMCPS) microspheres were first oxidized to aldehyde groups by dimethyl sulfoxide as oxidant via Kornblum oxidation reaction, obtaining aldehyde group‐modified microspheres, ALCPS microspheres, in which, a great quantity of benzaldehyde groups suspend from the main chain, and the effects of the main factors including the reaction temperature, the addition of KI as catalyst and the used amount of NaHCO3 as acid acceptor on the oxidation reaction were examined. Subsequently, the synchronic synthesizing and immobilizing of porphyrins on CPS microspheres were carried out via the Adler reaction between solid and liquid phases, in which, ALCPS microspheres, pyrrole and benzaldehyde or benzaldehyde analog in a solution were used as co‐reactants, resulting in porphyrin‐functionalized microspheres, and the influence of diverse factors including the acidity of the protonic acid catalyst, the substituent structure of benzaldehyde analog, and the polarity of the solvent as well as the swelling property of the solvent for CPS microspheres on the process of synchronously synthesizing and immobilizing porphyrins on CPS microspheres were investigated in depth. The experimental results indicate that via the designed route, the porphyrin‐functionalization of CPS microspheres can successfully be realized. For the Kornblum oxidation reaction, under the optimal reaction conditions, the conversion of chloromethyl groups can reach 90%. For the Adler reaction between solid and liquid phases, the fitting protonic acid catalyst is lactic acid, appropriate solvent is a mixture of dimethyl sulfoxide and xylene, and using 4‐chlorobenzaldehyde as a benzaldehyde analog reactant in the solution is in favor of the porphyrin‐functionalization of CPS microspheres. Under these specific conditions, the immobilized amount of porphyrin can get up to 23.33 mmol/100 g. Copyright © 2011 John Wiley & Sons, Ltd.
CNS irradiation in pediatric acute myleoid leukemia: Equal results by 12 or 18 Gy in studies AML‐BFM98 and 2004
Authors: Creutzig Ursula , Zimmermann Martin , Bourquin Jean‐Pierre , Dworzak Michael N. , Fleischhack Gudrun , von Neuhoff Christine , Sander Annette , Schrauder André , von Stackelberg Arend , Ritter Joerg , Starý Jan , Reinhardt Dirk
Published: April 2011

Background

The impact of preventive central nervous system irradiation (CNS‐RT) in childhood acute myeloid leukemia (AML) is still discussed. As results of study AML‐BFM87 revealed an increased risk for relapse when CNS‐RT was not performed, studies AML‐BFM98 and ‐2004 randomized CNS‐RT of 18 or 12 Gy in order to evaluate the efficacy of the lower dose and to reduce late effects.

Procedures

To achieve a power of 80% for non‐inferiority (range 11%) 240 patients per group were required. Out of 722 eligible patients, 486 patients <18 years were randomized to receive 12 Gy (n = 249) or 18 Gy (n = 237). Since this was a non‐inferiority study, the analysis was performed for patients as treated (12 Gy: n = 252 and 18 Gy: n = 219).

Results

Five‐year survival, event‐free survival and cumulative incidence of relapse were similar in patients who received 12 or 18 Gy, respectively (82 ± 3% vs. 79 ± 3%, 68 ± 3% vs. 63 ± 3%, and 30 ± 3% vs. 34 ± 3%). The lower limit of the one‐sided confidence interval for the −5% difference in 5‐years pEFS was 2%. There were six relapses with CNS involvement (one in the 12 Gy, and five in the 18 Gy group).

Conclusion

Results demonstrate no disadvantage for patients irradiated with a reduced CNS dose of 12 Gy. Pediatr Blood Cancer 2011; 57: 986–992. © 2011 Wiley‐Liss, Inc.
Body mass index (BMI) at diagnosis is associated with surgical wound complications in patients with localized osteosarcoma: A report from the Children's Oncology Group
Authors: Hingorani Pooja , Seidel Kristy , Krailo Mark , Mascarenhas Leo , Meyers Paul , Marina Neyssa , Conrad Ernest U. , Hawkins Douglas S.
Published: April 2011

Background

Malnutrition is common at diagnosis and during treatment for sarcoma patients. Poor nutritional status is associated with increased risk of complications, particularly infections. We investigated the role of body mass index (BMI) on the incidence of surgical wound complications in patients with localized osteosarcoma treated on the Children's Oncology Group (COG) legacy trial, INT‐0133.

Procedure

Patients considered in this report had localized osteosarcoma, enrolled on COG trial INT‐0133, remained on protocol therapy to have definitive surgery 6–16 weeks after study entry, and had adequate height, weight, and surgical complication data for analysis. By protocol design, definitive surgical resection was planned for 10 weeks after induction chemotherapy. Wound complications within 30 days after definitive surgery were considered post‐operative. BMI was calculated at the start of neoadjuvant chemotherapy and expressed as age‐ and gender‐adjusted percentile. The incidence of wound complications was evaluated by logistic regression or Fisher's exact test.

Results

A total of 498 patients met criteria for analysis. Low BMI (≤10th percentile) was seen in 73 (14.7%), middle BMI (11th–94th percentile) in 382 (76.7%), and high BMI (≥95th percentile) in 43 (8.6%) patients. Wound infection or slough was seen in low BMI patients (OR = 2.0, P = 0.07) although the results did not reach statistical significance. Arterial thrombosis was more common in high BMI patients (OR = 9.4, P = 0.03).

Conclusions

Abnormal BMI at the start of treatment for localized osteosarcoma is associated with increased risk of post‐operative wound complications such as arterial thrombosis. Future studies should evaluate whether maintenance of age‐appropriate BMI reduces the risk of surgical complications. Pediatr Blood Cancer 2011; 57: 939–942. © 2011 Wiley‐Liss, Inc.
Opsoclonus‐myoclonus and anti‐Hu positive limbic encephalitis in a patient with neuroblastoma
Authors: Morales La Madrid Andres , Rubin Charles M. , Kohrman Michael , Pytel Peter , Cohn Susan L.
Published: April 2011

Opsoclonus‐myoclonus syndrome (OMS) is seen in 2–3% of children with neuroblastoma and is believed to be caused by an autoimmune process elicited by the tumor. Although long‐term neurologic sequelae are common in children with OMS, limbic encephalitis has not previously been reported. We report a child who developed limbic encephalitis associated with anti‐Hu antibodies, 6 years after her initial diagnosis of neuroblastoma and OMS. This case demonstrates that patients with neuroblastoma and OMS are at risk for developing new paraneoplastic symptoms years after their original diagnosis and emphasizes the need for careful long‐term follow‐up. Pediatr Blood Cancer 2012; 58: 472–474. © 2011 Wiley Periodicals, Inc.
Slamming wave impact of a composite buoy for wave energy applications: Design and large‐scale testing
Authors: Van Paepegem W. , Blommaert C. , De Baere I. , Degrieck J. , De Backer G. , De Rouck J. , Degroote J. , Vierendeels J. , Matthys S. , Taerwe L.
Published: April 2011

In the European FP6 project SEEWEC, the design of a wave energy converter has been studied. The floating point absorbers that extract the wave energy were a crucial structure for the efficient functioning of this device and were manufactured from filament wound composite. Their mechanical design was to a large extent dominated by the survivability requirement in extreme storm conditions. During such storms, the structure is hit by very large waves. The associated mechanical loading by the waves is called “slamming,” which is characterized by very high local water pressures (several tens of bar) with short duration (ms) that act on the structure. This study discusses the mechanical design of the filament wound composite floating point absorbers, with the focus on the storm survivability conditions. The finite element calculations have been supported by small‐scale and large‐scale experimental tests, where the large‐scale tests simulate the repeated wave impacts under yearly storm conditions and the survival under extreme storm conditions. It has been proved that a design that takes into account the deformability of the structure can withstand the slamming loads, although it does not comply with the international design codes which assume rigid behavior of the impacted structure. Further, the experimentally measured slamming peak pressures strongly depend on the rigidity of the composite structure. Given the broad context of the covered research work and the imposed page limitations, this study does not pretend to give all the details of all the individual steps in the design and testing processes, but rather gives a comprehensive overview of the complete chain of design decisions and validations between finite element simulations and experiments. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Electroreductive block copolymerization of dichlorosilanes in the presence of disilane additives
Authors: Ishifune Manabu , Sana Chika , Ando Misako , Tsuyama Yohei
Published: April 2011

The electroreductive polymerization of dichloromethylphenylsilane in the presence of triphenylsilyl group‐containing disilanes such as hexaphenyldisilane followed by the electroreductive termination with chlorotriphenylsilane afforded triphenylsilyl group‐terminated polymethylphenylsilane in 15–32% yield. The isolated polymethylphenylsilane (Mn = 3350 g mol−1, Mw/Mn = 1.4) was found to react as a macroinitiator to copolymerize with dibutyldichlorosilane under electroreductive conditions producing the corresponding block copolymer (Mn = 4730 g mol−1, Mw/Mn = 1.2) in 38% yield. The ratio of monomer units (MeSiPhtoBuSiBu) of the copolymer was determined to be 75:25 using 1H NMR analysis, which was in good agreement with the calculated ratio (74:26) on the assumption that molecular weight of the macroinitiator was not changed. The block structure of the resulting copolymer, poly(methylphenylsilane)‐block‐poly(dibutylsilane), was also confirmed by comparing its 1H NMR and UV absorption spectra with those of polymethylphenylsilane, polydibutylsilane and a statistical copolymer prepared by electroreductive polymerization of dichloromethylphenylsilane with dibutyldichlorosilane. This method is applicable to the preparation of other types of macroinitiator such as triphenylsilyl group‐terminated polydibutylsilane, and polydibutylsilane‐block‐polymethylphenylsilane was also obtained using this macroinitiator. Copyright © 2011 Society of Chemical Industry
Molecular mobility in comb‐like copolymethacrylates with chalcone‐containing side‐chains
Authors: Nikonorova Natalia A , Diaz‐Calleja Ricardo , Yakimansky Alexander V
Published: April 2011

The molecular mobility of comb‐like copolymers of amyl methacrylate with N‐methacryloyl‐(4‐amino‐4′‐bromochalcone) with various concentrations (20, 30, 40, 50 and 60 mol%) of chalcone‐containing comonomer was studied using dielectric spectroscopy. It was found that chalcone chromophores participate in two forms of molecular mobility: cooperative motion in the rubbery state (δ‐relaxation) and local motion in the glassy state (β‐relaxation). In addition, α‐, β1‐ and γ‐processes, being related to cooperative segmental mobility, to local motion of ester groups adjacent to the backbone and to local motion of terminal side‐groups, respectively, were evident. The molecular mobility of the β1‐, β‐ and γ‐processes changed slightly with the concentration of chromophore groups. For the δ‐ and α‐processes, the glass transition temperatures, Tδ and Tg, increased with the molar fraction of chalcone groups, the difference between them remaining nearly constant (ca 55 °C). The Tδ values obtained should be considered as optimal temperatures for the corona‐poling of the chromophore‐containing polymers for the preparation of second‐order nonlinear optical polymer films with non‐centrosymmetric arrangement of chromophore groups. Copyright © 2011 Society of Chemical Industry
Synthesis and characterization of amphiphilic block polymers with amino groups and their conjugates with folic acid and fluorescent probes
Authors: Mo Guojun , Yue Jun , Ma Ping'an , Chen Xuesi , Huang Yubin , Jing Xiabin
Published: April 2011

Amphiphilic amino‐bearing biodegradable copolymers, [methoxy‐poly(ethylene glycol)]‐block‐poly[(L‐lactide)‐co‐(serinol carbonate)] (mPEG‐block‐P(LA‐co‐CA)), are prepared by synthesizing amino‐bearing cyclic carbonate monomer N‐benzoxycarbonylserinol carbonate (CAB) starting from serinol, by ring‐opening polymerization of L‐lactide and CAB using diethylzinc as catalyst and mPEG as macroinitiator, and by subsequent removal of the protective benzyloxycarbonyl groups by HBr treatment. After deprotection, the pendant amino groups on the carbonate units are reacted with N‐hydroxylsuccinimide‐activated folic acid (FA) to achieve mPEG‐block‐P(LA‐co‐CA/FA) conjugate and with fluorescein isothiocyanate (FITC) to achieve mPEG‐block‐P(LA‐co‐CA/FITC) conjugate. The structures of mPEG‐block‐P(LA‐co‐CAB), mPEG‐block‐P(LA‐co‐CA), mPEG‐block‐P(LA‐co‐CA/FA) and mPEG‐block‐P(LA‐co‐CA/FITC) are confirmed using 1H NMR and Fourier transform infrared spectroscopy. The block copolymers can self‐assemble into micelles in aqueous solution. Because of the functionality of FA and FITC, these copolymers can find important applications in drug delivery systems to serve as targeting moieties and fluorescent probes. Copyright © 2011 Society of Chemical Industry
A novel approach to modify poly(vinylidene fluoride) via iron‐mediated atom transfer radical polymerization using activators generated by electron transfer
Authors: Zhao Tao , Zhang Lifen , Zhang Zhengbiao , Zhou Nianchen , Cheng ZhenPing , Zhu XiuLin
Published: April 2011

Iron‐mediated atom transfer radical polymerization using activators generated by electron transfer directly from the secondary fluorine atoms on the poly(vinylidene fluoride) (PVDF) backbone, using methyl methacrylate (MMA) and poly (ethylene glycol) methyl ether methacrylate (PEGMA) as the monomers, FeCl3·6H2O as the catalyst, PPh3 as the ligand, and vitamin C as the reducing agent, was demonstrated in the presence of limited amounts of air. The successful syntheses of the corresponding graft copolymers PVDF‐g‐PMMA and PVDF‐g‐PPEGMA were characterized by nuclear magnetic resonance, Fourier transform infrared and X‐ray photoelectron spectroscopy, respectively. The graft copolymers PVDF‐g‐PPEGMA can be readily cast into porous hydrophilic microfiltration membranes by phase inversion in an aqueous medium. The morphologies were characterized by scanning electron microscopy. The surface and bulk hydrophilicity were evaluated on the basis of static water contact angle and the steady adsorption of bovine serum albumin. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Electrospun polymer nanofibers: Mechanical and thermodynamic perspectives
Authors: Arinstein Arkadii , Zussman Eyal
Published: April 2011

This article reviews and discusses some open problems concerning polymer materials of reduced sizes and dimensions. Such objects exhibit exceptional physical properties when compared with their macroscopic counterparts. More specifically, abrupt increases in polymer nanofiber elastic modulus have been observed when diameters drop below a certain value. In addition, temperature dependence of elastic modulus is highly influenced by fiber diameter. Mechanical (macroscopic) analyses have failed to provide satisfactory explanations for the mechanisms ruling such features, calling for detailed microscopic examination of the systems in question. A hypothesis bridging the current knowledge gaps is presented. The key element of this hypothesis is based on confinement of the supermolecular microstructure of polymer nanofibers and its dominant role in the deformation process. This suggestion challenges the commonly held view suggesting that surface effects are the most significant parameters impacting mechanical and thermodynamic nanofiber behaviors. The review will focus on the mechanical and thermodynamic properties of electrospun polymer nanofibers, selected as representatives of nanoscale polymer objects. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011
Integration of soil application and seed treatment formulations of Trichoderma species for management of wet root rot of mungbean caused by Rhizoctonia solani
Authors: Dubey Sunil C , Bhavani Ranganaicker , Singh Birendra
Published: April 2011

BACKGROUND: The efficacy of seed dressing and soil application formulations from the isolates of Trichoderma viride (IARI P1; MTCC 5369), T. virens (IARI P3; MTCC 5370) and T. harzianum (IARI P4; MTCC 5371) were evaluated individually and in combination in pot and field experiments during the rainy seasons of 2005, 2006 and 2007 for the management of wet root rot (Rhizoctonia solani) and improvement in the yield of mungbean.

RESULTS: A seed dressing formulation, Pusa 5SD, and soil application formulations, Pusa Biogranule 6 (PBG 6) and Pusa Biopellet 16G (PBP 16G), based on Trichoderma virens, were found to be superior to other formulations in reducing disease incidence and increasing seed germination and shoot and root lengths in mungbean. In field experiments, a combination of soil application with PBP 16G (T. virens) and seed treatment with Pusa 5SD (T. virens) + carboxin was superior to any of these formulations individually in increasing seed germination, shoot and root lengths and grain yield and reducing wet root rot incidence in mungbean. Seed treatment was more effective than soil application for all the evaluated parameters. The combined application of Pusa 5SD and carboxin was also superior to individual treatment.

CONCLUSION: The efficacy of the evaluated formulations against wet root rot of mungbean proved that the integration of soil application of PBP 16G and seed treatment with Pusa 5SD + carboxin is highly effective for the management of wet root rot, increasing plant growth and grain yield of mungbean Copyright © 2011 Society of Chemical Industry
Theoretical modeling of growth processes, extended defects, and electronic properties of III‐nitride semiconductor nanostructures
Authors: Lymperakis Liverios , Abu‐Farsakh Hazem , Marquardt Oliver , Hickel Tilmann , Neugebauer Jörg
Published: April 2011

Ab initio based simulations have been proven in the past to be and still are a valuable and indispensable tool in the field of III‐nitride semiconductors. They have been successfully used to explain, describe and guide growth and characterization experiments and to address a large variety of material problems at different length scales. In the present report we review on five selected topics which span different length scales, various method developments, and diverse material properties that have been theoretically addressed within the research group “Physics of nitride‐based, nanostructured, light emitting devices.”

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Schematic representation of theoretical modeling in synergy with experiment. Left: Ab initio calculated potential energy surface for adatom diffusion on the side facets of a GaN nanowire [theory from L. Lymperakis et al., Phys. Rev. B 79, 241308 (2009), SEM image from T. Aschenbrenner et al., Nanotechnology 20, 075604 (2009)]. Right: Electrostatic potential in a QD calculated by Poisson solver [theory from O. Marquardt et al., J. Appl. Phys. 106, 083707 (2009), HRTEM image from A. Pretorius et al., J. Cryst. Growth 310, 748 (2008)].
High‐pressure Raman investigation of the semiconductor antimony oxide
Authors: Geng Aihui , Cao Lihua , Wan Chunming , Ma Yanmei
Published: April 2011

The in situ high‐pressure behavior of the semiconductor antimony trioxide (Sb2O3) has been investigated by Raman spectroscopy techniques in a diamond anvil cell up to 20 GPa at room temperature. New peaks in the external lattice mode range emerged at a pressure above 8.6‐15 GPa, suggesting that the structural phase transition occurred. The pressure dependence of Raman frequencies was obtained. The band at 139 cm‐1 (assigned to group mode) has a pressure dependence of ‐0.475 cm‐1/GPa and reveals significant softening at high pressure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)