bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of nitrogen fertilization on nitrogen dynamics in oilseed rape using 15N‐labeling field experiment
Authors: Gombert Julie , Le Dily Frédérik , Lothier Jérémy , Etienne Philippe , Rossato Laurence , Allirand Jean‐Michel , Jullien Alexandra , Savin Alexandre , Ourry Alain 
Published: October 2010

AbstractIn order to optimize nitrogen (N) fertilization and to reduce the environmental impact of oilseed rape without decreasing yield, a clearer understanding of N dynamics inside the plant is crucial. The present investigation therefore aimed to study the effects of different N‐application rates on the dynamics of N uptake, partitioning, and remobilization. The experiment was conducted on winter oilseed rape (Brassica napus L. cv. Capitol) under three levels of N input (0, 100, and 200 kg N ha–1) from stem elongation to maturity using 15N‐labeling technique to distinguish between N uptake and N retranslocation in the plant. Nitrogen fertilization affected the time‐course of N uptake and also the allocation of N taken up from flowering to maturity. Most pod N came from N remobilization, and leaves accounted for the largest source of remobilized N regardless the N‐application rate. However, the contribution of leaves to the remobilized N pool increased with the N dose whereas the one of taproot decreased. Stems were the main sink for remobilized N from stem elongation to flowering. Leaves remained longer on N200 than on N0 and N100 plants, and N concentration in fallen leaves increased with the N treatment and in N100 plants along an axial gradient from the basal to the upper leaves. Overall, these results show that the timing of N supply is more crucial than the N amount to attain a high N efficiency.
Electronic and structural effects on the nonlinear optical behavior in π‐conjugated structure bis(4‐nitrophenyl) carbonate: a vibrational spectroscopic approach
Authors: Ravikumar C. , Ramachandra Miss Pillai Indu , Hubert Joe I. 
Published: October 2010

AbstractFourier transform (FT)‐Raman and infrared (IR) spectra of the nonlinear optical (NLO) material bis(4‐nitrophenyl) carbonate were recorded and analyzed. The geometry, first hyperpolarizability and harmonic vibrational wavenumbers were calculated with the help of Becke3–Lee–Yang–Parr density functional theory method. The detailed interpretation of the vibrational spectra was carried out with the aid of normal coordinate analysis following the scaled quantum mechanical force field methodology. The second‐order NLO properties of the molecule were studied by the Kurtz and Perry powder reflection technique. Stability of the molecule arising from hyperconjugative interactions leading to its NLO activity and charge delocalization were analyzed using natural bond orbital analysis. Copyright © 2010 John Wiley & Sons, Ltd.
Simple determination of azasetron in rat plasma by column‐switching high‐performance liquid chromatography
Authors: Um So Young , Chae Song Wha , Park Hyun Joo , Chung Myeon Woo , Choi Sun Ok , Lee Hwa Jeong 
Published: October 2010

AbstractFor the quantification of azasetron in rat plasma samples, a column‐switching HPLC method was developed and validated. Following dilution of plasma samples with mobile phase A (17 mM potassium phosphate buffer (pH 3.0)) and simple protein precipitation by addition of perchloric acid (60%), the mixture was directly injected onto the pre‐column. After endogenous plasma substances were eluted to waste, the analyte was transferred to the trap column by switching the system. Then, the analyte was back‐flushed to the analytical column for separation with mobile phase B (a 22:78 v/v mixture of acetonitrile and 17 mM potassium phosphate buffer (pH 3.0)) and detected at 250 nm using a photodiode array detector. A linear standard curve was obtained in the concentration range of 10–800 ng/mL with the correlation coefficient (r) of 0.9998. The intra‐ and inter‐day precision and accuracy values for azasetron were in the ranges of 0.3−12.9% and 89.7−101.4%, respectively. The method was valid in terms of specificity, precision, and accuracy. In addition, this efficient analytical method was successfully applied to determine plasma concentrations of azasetron following oral administration of azasetron at a dose of 4.0 mg/kg to rats.
Contact‐Active Antimicrobial and Potentially Self‐Polishing Coatings Based on Cellulose
Authors: Bieser Arno M. , Thomann Yi , Tiller Joerg C. 
Published: October 2010

AbstractA contact‐active antimicrobial coating is described that is only degraded in the presence of cellulase, which is an extracellular enzyme of numerous microbial strains. Antimicrobial DDA was grafted to a cellulose backbone via a polymeric spacer. The antimicrobial activity of the coatings, their biodegradability and their self‐polishing potential were investigated. It was found that all coatings were antimicrobially active against Staphylococcus aureus. Coatings with high DS and long polymeric spacers degraded in water, while coatings with low DS and short spacers were not hydrolyzed even in the presence of cellulase. One coating was found to be selectively degradable by cellulase and recovered most of its antimicrobial activity after overloading and subsequent treatment with cellulase.
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Thermal, Mechanical, and Surface Properties of Poly(2‐N‐alkyl‐2‐oxazoline)s
Authors: Rettler Erik F.‐J. , Kranenburg Johannes M. , Lambermont‐Thijs Hanneke M.L. , Hoogenboom Richard , Schubert Ulrich S. 
Published: October 2010

AbstractThermal, mechanical, and surface properties of a library of poly(2‐oxazoline)s are investigated. These polymers are suitable to study structure/property relationships as their cationic ROP and the relative facile monomer synthesis allow for control over the molecular structure. The number of carbon atoms in the linear side‐chain is systematically varied from methyl to nonyl. Relations between chemical structures, thermal transitions, surface energies, and elastic moduli are discussed. It is shown that the mechanical and thermal properties of the polymers depend on the presence of a crystalline phase in the material. The amorphous polymers reveal a decrease in the reduced moduli along with a decrease in their respective glass transition temperature with increasing length of the side‐chain.
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Xanthene‐Based Oligothiophene‐Layered Polymers
Authors: Morisaki Yasuhiro , Fernandes Jonas Alves , Chujo Yoshiki 
Published: October 2010

AbstractWe synthesized xanthene‐based oligothiophene‐layered polymers containing bithiophenes, terthiophenes, quaterthiophenes and quinquethiophenes by the Suzuki‐Miyaura coupling reaction. The polymers were characterized by various spectroscopic and electrochemical methods. They were well soluble in common organic solvents and thermally stable. Effective π‐π interactions among the layered oligothiophene units in the polymer backbone were not observed in the ground state as well as in the excited state. A possible application of the polymers in opto‐electronic devices such as hole transporting materials is expected.
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Supramolecular Thermoresponsive Hyperbranched Polymers Constructed from Poly(N‐Isopropylacrylamide) Containing One Adamantyl and Two β‐Cyclodextrin Terminal Moieties
Authors: Ge Zhishen , Liu Hao , Zhang Yanfeng , Liu Shiyong 
Published: October 2010

AbstractPoly(N‐isopropylacrylamide) (PNIPAM) oligomer containing one adamantyl (AD) and two β‐cyclodextrin (β‐CD) moieties at the chain terminals, AD‐PNIPAM‐(β‐CD)2, was synthesized by atom transfer radical polymerization (ATRP) and successive click reactions. In aqueous solution, AD‐PNIPAM‐(β‐CD)2 spontaneously forms supramolecular thermoresponsive hyperbranched polymers via molecular recognition between AD and β‐CD moieties. To the best of our knowledge, this work represents the first report of the construction of supramolecular thermoresponsive hyperbranched polymers from well‐defined polymeric AB2 building units.magnified image
Uniform PEO Star Polymers Synthesized in Water via Free Radical Polymerization or Atom Transfer Radical Polymerization
Authors: Li Wenwen , Matyjaszewski Krzysztof 
Published: October 2010

AbstractAmphiphilic star shaped polymers with poly(ethylene oxide) (PEO) arms and cross‐linked hydrophobic core were synthesized in water via either conventional free radical polymerization (FRP) or atom transfer radical polymerization (ATRP) techniques using a simple “arm‐first” method. In FRP, PEO based macromonomers (MM) were used as arm precursors, which were then cross‐linked by divinylbenzene (DVB) using 2,2′‐azoisobutyronitrile (AIBN). Uniform star polymers ($\overline {M} _{{\rm w}} /\overline {M} _{{\rm n}} $ < 1.2) were achieved through adjustment of the ratio of PEO MM, DVB, and AIBN. While in case of ATRP, both PEO MM, and PEO based macroinitiator (MI) were used as arm precursors with ethylene glycol diacrylate as cross‐linker. Even more uniform star polymers with less contamination by low MW polymers were obtained, as compared to the products synthesized by FRP.magnified image
Unveiling the methylation status of CpG dinucleotides in the substituted segment of the human p53 knock‐in (Hupki) mouse genome
Authors: Kim Sang‐In , Hollstein Monica , Pfeifer Gerd P. , Besaratinia Ahmad 
Published: October 2010

AbstractMethylated cytosines within CpG dinucleotides (mCpGs) along the DNA‐binding domain of the TP53 tumor suppressor gene (exons ∼5–8) are the single most significant mutational target in human cancers. The human p53 knock‐in (Hupki) mouse model was constructed using gene‐targeting technology to create a mouse strain that harbors human wild‐type TP53 DNA sequences spanning exons 4–9 in both copies of the mouse p53 gene. To date, however, the methylation status of cytosines within CpGs in the substituted segment of the Hupki mouse genome has not been determined. This lack of information deserves special attention because DNA methylation in mammals, which occurs almost exclusively within CpG dinucleotides, is a dynamic process throughout developmental stages and may vary among different species. Here, we have investigated the status of CpG methylation in the substituted segment of the Hupki mouse genome, and compared it to the methylation profile of the corresponding segment in the human genome using the combined bisulfite‐restriction analysis and sodium bisulfite genomic sequencing. We found that all cytosines within CpGs of the TP53 DNA‐binding domain, on both the coding and noncoding strands, were heavily methylated in Hupki fibroblasts, as they were in human fibroblasts. This is in keeping with the fully methylated status of TP53 CpGs that is known to prevail in adult human tissues. The remarkably similar patterns of cytosine methylation within CpG dinucleotides in Hupki cells and human cells further validates the suitability of mutagenesis assays in Hupki cells for experimental induction of TP53 mutations that have been observed in human tumors. © 2010 Wiley‐Liss, Inc.
Loss of tyrosine phosphatase‐dependent inhibition promotes activation of tyrosine kinase c‐Src in detached pancreatic cells
Authors: Connelly Sarah F. , Isley Beth A. , Baker Cheryl H. , Gallick Gary E. , Summy Justin M. 
Published: October 2010

AbstractDespite an intense focus on novel therapeutic strategies, pancreatic adenocarcinoma remains one of the deadliest human malignancies. The frequent and rapid mortality associated with pancreatic cancer may be attributed to several factors, including late diagnosis, rapid tumor invasion into surrounding tissues, and formation of distant metastases. Both local invasion and metastasis require disruption of tumor cell contacts with the extracellular matrix. Detachment of normal cells from the extracellular matrix leads to a form of programmed cell death termed anoikis. Pancreatic cancer cells avert anoikis by activation of signaling pathways that allow for adhesion‐independent survival. In the present studies, cellular signaling pathways activated in detached pancreatic cancer cells were examined. We demonstrate a rapid and robust activation of Src kinase in detached pancreatic cancer cells, relative to adherent. Src autophosphorylation rapidly returned to baseline levels upon reattachment to tissue culture plastic, in the presence or absence of specific extracellular matrix proteins. Treatment of pancreatic cancer cells with tyrosine phosphatase inhibitors increased steady‐state Src autophosphorylation in adherent cells and abrogated the detachment‐induced increase in Src autophosphorylation. Src was found to co‐immunoprecipitate with the Src homology 2 (SH2) domain containing protein tyrosine phosphatase (SHP‐2) in pancreatic cancer cells, suggesting that SHP‐2 may participate in regulation of Src autophosphorylation in adherent cells. Src family kinase (SFK) dependent increases in Akt and Jun N‐terminal kinase (JNK) phosphorylation were observed in detached cells, indicating the potential for Src‐dependent activation of survival and stress pathways in pancreatic cancer cells that have detached from the extracellular matrix. © 2010 Wiley‐Liss, Inc.
Association of angiotensin I converting enzyme (insertion/deletion) and angiotensin II type 1 receptor (A1166C) polymorphisms with breast cancer prognostic factors in iranian population
Authors: Namazi Soha , Monabati Ahmad , Ardeshir‐Rouhani‐Fard Shirin , Azarpira Negar 
Published: October 2010

AbstractIt has been indicated that renin‐angiotensin system (RAS) has role in various steps of cancer progression. The presence of RAS components has been shown in normal and breast cancer tissue. Insertion/Deletion (I/D) is one of angiotensin I converting enzyme (ACE) polymorphisms and A1166C is one of Angiotensin II type‐1 receptor (AT1R) polymorphisms which have been associated with various diseases such as cardiovascular diseases. In the present study, we aimed to substantiate the putative significance of ACE and AT1R on breast cancer biology by investigating the influence of their gene polymorphisms on breast cancer progression. The I/D and A1166C polymorphisms were evaluated by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP), respectively in 70 breast cancer patients diagnosed with invasive breast cancer and 70 healthy women. Breast cancer prognostic factors were obtained from medical and pathology reports of patients. There was no significant difference between cases and controls for ACE (I/D) (P = 0.15) and AT1R (A1166C) genotypes (P = 0.86). In breast cancer patients, when DD genotype was used as reference group, the combination of II and ID genotypes was associated with increased HER‐2 expression (P = 0.020; OR, 4.58; 95% CI, 1.26–16.60). Also, when AA genotype was used as reference group, the AC genotype was associated with higher tumor TNM stage (P = 0.024; OR, 4.66; 95% CI, 1.18–18.35). This is the first study indicating that ACE (I/D) polymorphism is associated with HER‐2 expression and AT1R (A1166C) polymorphism is associated with tumor TNM stage in breast cancer patients. © 2010 Wiley‐Liss, Inc.
Instability of syllable repetition as a marker of disease progression in Parkinson's disease: A longitudinal study
Authors: Skodda Sabine , Flasskamp Andrea , Schlegel Uwe 
Published: October 2010

AbstractParkinsonian speakers show a tendency to articulatory acceleration and have difficulties to keep the steady pace of repeated syllables. The aim of this study was to analyse the stability of motor speech performance based upon a syllable repetition paradigm during the course of disease to find a potential marker of disease progression in Parkinson's disease (PD). 58 patients withPD and 35 controls were tested and re‐tested after at least 12 months (mean: 33.40/range: 12–88). In the PD group, motor impairment was similar at first and second visit. Participants had to repeat the syllable /pa/ in a self chosen steady pace. Percental coefficient of variance (COV) of interval length was measured for description of pace stability throughout the performance. Percental pace acceleration (%PA) was based upon a comparison of the speed of syllable repetition in the first and second half of the task. Patients with PD showed a significant elevation of COV and %PA indicating an instability of syllable repetition and a tendency to pace acceleration in the course of performing. Furthermore, in the PD group, COV and %PA showed a significant deterioration from first to second examination. Instability of steady syllable repetition in PD shows characteristic changes during the course of the disease, but no correlation with general motor impairment. Therefore, the underlying mechanism may be independent from dopaminergic deficits. The potential role of impaired syllable repetition as a marker of non‐dopaminergic disease progression in PD needs validation by further studies. © 2010 Movement Disorder Society
Differential genetic susceptibility in diphasic and peak‐dose dyskinesias in Parkinson's disease
Authors: Lee Jee‐Young , Cho Jinwhan , Lee Eun‐Kyung , Park Sung‐Sup , Jeon Beom S. 
Published: October 2010

AbstractTo examine whether there is a differential genetic susceptibility in the diphasic and peak‐dose forms of levodopa‐induced dyskinesias (LID) in patients with Parkinson's disease (PD). The study cohort comprised 503 unrelated Korean PD patients who were treated with levodopa and had a disease duration of at least 5 years. The presence of LID was identified during a routine follow‐up and special care was taken to separate the two distinct forms of LID into diphasic and peak‐dose dyskinesias (PDSK). Genotyping was performed in the 503 patients and in 559 healthy controls to search for polymorphisms of DRD3 p.S9G, DRD2 Taq1A, GRIN2B c.2664C>T, c.366C>G, c.‐200T>G, and the promoter region of SLC6A4. A total of 229 patients expressed LID (peak‐dose in 205, diphasic in 57, and both in 33). The presence of diphasic dyskinesia (DDSK) was exclusively associated with the DRD3 p.S9G variant after adjusting for gender, age at PD onset, Hoehn & Yahr stage, and duration of levodopa treatment. Carrying the AA genotype was likely to shorten the onset of DDSK according to the duration of levodopa therapy (P = 0.02). The presence of PDSK was not significantly associated with any of the six genetic variants studied. There may be a genetic susceptibility in the development of DDSK in PD patients on chronic levodopa therapy, and its underlying pathophysiological mechanism might be distinct from that of PDSK. © 2010 Movement Disorder Society
Laser induced defects in laser doped solar cells
Authors: Hameiri Z. , Puzzer T. , Mai L. , Sproul A. B. , Wenham S. R. 
Published: October 2010

AbstractLaser doping offers a promising method to define selective emitters for solar cells. Its main advantage is the localised nature of the laser beam, which allows melting of the surface area without heating the bulk. The ability to perform this process over a dielectric film offers further benefits, such as the possibility of creating self‐aligned metallisation patterns simultaneously with the selective emitter formation. However, laser induced defects, contaminations and discontinuities in the selective emitter can reduce solar cell performance. In this work the influence of different dielectric films on defect formation is investigated. It was found that a thin oxide beneath the SiNximproves the implied open circuit voltage of the solar cells for a wide range of laser output powers. Fewer defects were observed when using this SiO2/SiNxstack compared to the standard single SiNxanti‐reflection coating layer. It was also found that the recrystallised silicon layer grows epitaxially according the substrate orientation. No dislocation or stacking faults were observed in deeper areas using transmission electron microscopy, although some defects were observed near the surface. Electron beam induced current images revealed discontinuities in junctions formed with high laser powers. We conclude that micro‐cracks create these discontinuities, which can potentially induce shunts. Finally, laser doped solar cells with a standard SiNxand with a double SiO2/SiNxstack layer as anti‐reflection coating were compared. An efficiency of 18.4% on a large area commercial grade p‐type CZ substrate was achieved. Copyright © 2010 John Wiley & Sons, Ltd.
One‐pot preparation of ABA‐type block‐graft copolymers via a combination of “click” chemistry with atom transfer nitroxide radical coupling reaction
Authors: Jing Rongkuan , Wang Guowei , Huang Junlian 
Published: October 2010

AbstractA new strategy for the one‐pot preparation of ABA‐type block‐graft copolymers via a combination of Cu‐catalyzed azide‐alkyne cycloaddition (CuAAC) “click” chemistry with atom transfer nitroxide radical coupling (ATNRC) reaction was reported. First, sequential ring‐opening polymerization of 4‐glycidyloxy‐2,2,6,6‐tetramethylpiperidine‐1‐oxyl (GTEMPO) and 1‐ethoxyethyl glycidyl ether provided a backbone with pendant TEMPO and ethoxyethyl‐protected hydroxyl groups, the hydroxyl groups could be recovered by hydrolysis and then esterified with 2‐bromoisobutyryl bromide, the bromide groups were converted into azide groups via treatment with NaN3. Subsequently, bromine‐containing poly(tert‐butyl acrylate) (PtBA‐Br) was synthesized by atom transfer radical polymerization. Alkyne‐containing polystyrene (PS‐alkyne) was prepared by capping polystyryl‐lithium with ethylene oxide and subsequent modification by propargyl bromide. Finally, the CuAAC and ATNRC reaction proceeded simultaneously between backbone and PtBA‐Br, PS‐alkyne. The effects of catalyst systems on one‐pot reaction were discussed. The block‐graft copolymers and intermediates were characterized by size‐exclusion chromatography, 1H NMR, and FT‐IR in detail. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
A novel fluorine‐containing graft copolymer bearing perfluorocyclobutyl aryl ether‐based backbone and poly(methyl methacrylate) side chains
Authors: Liu Hao , Li Yongjun , Zhang Sen , Yang Dong , Hu Jianhua , Huang Xiaoyu 
Published: October 2010

AbstractA series of novel graft copolymers consisting of perfluorocyclobutyl aryl ether‐based backbone and poly(methyl methacrylate) side chains were synthesized by the combination of thermal [2π + 2π] step‐growth cycloaddition polymerization of aryl bistrifluorovinyl ether monomer and atom transfer radical polymerization (ATRP) of methyl methacrylate. A new aryl bistrifluorovinyl ether monomer, 2‐methyl‐1,4‐bistrifluorovinyloxybenzene, was first synthesized in two steps from commercially available reagents, and this monomer was homopolymerized in diphenyl ether to provide the corresponding perfluorocyclobutyl aryl ether‐based homopolymer with methoxyl end groups. The fluoropolymer was then converted to ATRP macroinitiator by the monobromination of the pendant methyls with N‐bromosuccinimide and benzoyl peroxide. The grafting‐from strategy was finally used to obtain the novel poly(2‐methyl‐1,4‐bistrifluorovinyloxybenzene)‐g‐poly(methyl methacrylate) graft copolymers with relatively narrow molecular weight distributions (Mw/Mn ≤ 1.46) via ATRP of methyl methacrylate at 50 °C in anisole initiated by the Br‐containing macroinitiator using CuBr/dHbpy as catalytic system. These fluorine‐containing graft copolymers can dissolve in most organic solvents. This is the first example of the graft copolymer possessing perfluorocyclobutyl aryl ether‐based backbone. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010