bluuebunny/crossref_metadata_2025 huggingface dataset:
Biocompatibility and antibacterial activity of chitosan and hyaluronic acid immobilized polyester fibers
Authors: Jou Chi‐Hsiung , Yuan Ling , Lin Shang‐Ming , Hwang Mou‐Chuan , Chou Wen‐Li , Yu Da‐Guang , Yang Ming‐Chien
Published: January 2007

Poly(ethylene terephthalate) (PET) fibers were treated with 60Co‐γ‐ray and grafted with acrylic acid. The resulting fibers were further grafted with chitosan (CS) via esterification. Afterward, hyaluronic acid (HA) was immobilized onto CS‐grafting fibers. The antibacterial activity of CS against S. aureus, E. coli, and P. aeruginosa was preserved after HA‐immobilization. After immobilizing HA, the L929 fibroblasts cell proliferation was improved forCS‐grafting PET fiber. The results indicate that by grafting with CS and immobilizing with HA, PET fibers not only exhibit antibacterial activity, but also improve the cell proliferation for fibroblast. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 220–225, 2007
Microstructured conducting polymer coatings on plastic strip for contact electrodes: Formulation and tuning of sheet resistance
Authors: Daniel Abraham , Fotheringham Alex
Published: January 2007

Mechanically strong and flexible strips of cellulose acetate were used to support a thin coating of poly(3,4 ethylenedioxythiophene) : poly(styrene sulfonic acid) PEDOT : PSS, an intrinsically conducting polymer (ICP), formulated with an aqueous dispersion of judiciously chosen copolymer of vinyl acetate and ethylene (VAE), to impart adhesion of the coating onto the substrate. Incorporation of a few drops of an organic acid to the formulation resulted in a substantial reduction of the sheet resistance of the coated surface. When the coated strips were post‐treated with a salt solution, a further fine tuning of the sheet resistance by a factor of 10 was achieved. The coated strips combine high conductivity with flexibility and mechanical strength. The performance of the coated strips has been evaluated in relationship to composition, coating thickness, and sheet resistance for application as contact electrodes. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 234–237, 2007
Synthesis and mesomorphic properties of side‐chain liquid crystalline ionomers containing sulfonic acid groups
Authors: Zhang Bao‐Yan , Sun Qiu‐Ju , Tian Mei , Ren Shi‐Chao
Published: January 2007

Side‐chain liquid crystalline ionomers containing M1 (4‐allyoxybenzoyloxy‐4′‐amylbenzoyloxy biphenyl) as mesogenic units and M2 (4‐undecylenicoxy‐4′‐phenylazobenzene sulfonic acid) as ionic units were synthesized by graft copolymerization. Their liquid crystalline properties were characterized by differential scanning calorimetry, polarizing optical microscopy, and X‐ray diffraction measurements. The results showed that introduction of nonmesogenic ionic units into polymeric structure could cause additional reduction of the clearing point of the ionomers, compared with the corresponding nonion polymers. When the content of ionic units increased to 8.5%, the ionic clusters and mesogens in the ionomers may be dispersed each other to form multiple blocks, but the introduction of ionic groups in LCIs did not change their mesogenic type. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 304–309, 2007
Effect of clay on properties of polyimide‐clay nanocomposites
Authors: Wang Hong‐Wen , Dong Rui‐Xuan , Liu Ching‐Lin , Chang Hsin‐Yu
Published: January 2007

Effect of clay on mechanical, thermal, moisture absorption, and dielectric properties of polyimide‐clay nanocomposites was investigated. Nanocomposites of polyimide (ODA‐BSAA) hybridized with two modified clay (PK‐802 and PK‐805) were synthesized for comparison. The silicate layers in the polymer matrix were intercalated/exfoliated as confirmed by wide‐angle X‐ray diffraction and transmission electron microscopy. Thermal stability, moisture absorption, and storage modulus for these nanocomposites are improved as hybridized clay increases. Reduced dielectric constants due to the hybridization of layered silicates are observed at frequencies of 1 kHz–1 MHz and temperatures of 35–150°C. The tetrahedrally substituted smectite (PK‐805) resulted in higher mechanical strength and dielectric constants than those of octahedrally substituted smectite (PK‐802), which could be attributed to their stronger ionic bonding between clay layer and polymer matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 318–324, 2007
Genome‐scale analysis of Saccharomyces cerevisiae metabolism and ethanol production in fed‐batch culture
Authors: Hjersted Jared L. , Henson Michael A. , Mahadevan Radhakrishnan
Published: January 2007

A dynamic flux balance model based on a genome‐scale metabolic network reconstruction is developed for in silico analysis of Saccharomyces cerevisiae metabolism and ethanol production in fed‐batch culture. Metabolic engineering strategies previously identified for their enhanced steady‐state biomass and/or ethanol yields are evaluated for fed‐batch performance in glucose and glucose/xylose media. Dynamic analysis is shown to provide a single quantitative measure of fed‐batch ethanol productivity that explicitly handles the possible tradeoff between the biomass and ethanol yields. Productivity optimization conducted to rank achievable fed‐batch performance demonstrates that the genetic manipulation strategy and the fed‐batch operating policy should be considered simultaneously. A library of candidate gene insertions is assembled and directly screened for their achievable ethanol productivity in fed‐batch culture. A number of novel gene insertions with ethanol productivities identical to the best metabolic engineering strategies reported in previous studies are identified, thereby providing additional targets for experimental evaluation. The top performing gene insertions were substrate dependent, with the highest ranked insertions for glucose media yielding suboptimal performance in glucose/xylose media. The analysis results suggest that enhancements in biomass yield are most beneficial for the enhancement of fed‐batch ethanol productivity by recombinant xylose utilizing yeast strains. We conclude that steady‐state flux balance analysis is not sufficient to predict fed‐batch performance and that the media, genetic manipulations, and fed‐batch operating policy should be considered simultaneously to achieve optimal metabolite productivity. Biotechnol. Bioeng. 2007; 97: 1190–1204. © 2007 Wiley Periodicals, Inc.
Recurrences and second primary breast cancers in older women with initial early‐stage disease
Authors: Geiger Ann M. , Thwin Soe Soe , Lash Timothy L. , Buist Diana S. M. , Prout Marianne N. , Wei Feifei , Field Terry S. , Ulcickas Yood Marianne , Frost Floyd J. , Enger Shelley M. , Silliman Rebecca A.
Published: January 2007

BACKGROUND.

The association between common breast cancer therapies and recurrences and second primary breast cancers in older women is unclear, although older women are less likely to receive common therapies.

METHODS.

Women aged ≥65 years who were diagnosed with stage I or II breast cancer and who underwent mastectomy or breast‐conserving surgery (BCS) from 1990 to 1994 were identified from automated data from 6 healthcare systems and then were followed for 10 years or until breast cancer recurrence, disenrollment, or death. Trained abstractors reviewed medical records to obtain recurrence, tumor, treatment and demographic data. The authors used proportional hazards models to examine predictors of recurrent and second primary breast cancers adjusted for demographic and tumor factors.

RESULTS.

Of 1837 eligible women, 34% were ages 65 to 69 years, 46% were ages 70 to 79 years, and 20% were aged ≥80 years. In multivariable models that used mastectomy as the reference group, BCS without radiation therapy was associated with an increased risk of any recurrent and second primary breast cancer (hazard ratio [HR], 1.6; 95% confidence interval [CI], 1.1–2.3), particularly with the subgroup of women with local and regional recurrence (HR, 3.5; 95% CI, 2.0–6.0). Tamoxifen use for <1 year versus ≥5 years exhibited a borderline association with any recurrent or second primary breast cancer (HR, 1.9; 95% CI, 0.9–4.2).

CONCLUSIONS.

Radiation therapy after BCS and 5 years of tamoxifen use were beneficial in reducing recurrences and second primary breast cancers in older women, regardless of their age or comorbidity burden. Cancer 2007. © 2007 American Cancer Society.
Amplification and translocation of 3q26 with overexpression of EVI1 in Fanconi anemia‐derived childhood acute myeloid leukemia with biallelic FANCD1/BRCA2 disruption
Authors: Meyer Stefan , Fergusson William D. , Whetton Anthony D. , Moreira‐Leite Flavia , Pepper Stuart D. , Miller Crispin , Saunders Emma K. , White Daniel J. , Will Andrew M. , Eden Tim , Ikeda Hideyuki , Ullmann Reinhard , Tuerkmen Seval , Gerlach Antje , Klopocki Eva , Tönnies Holger
Published: January 2007

Fanconi anemia (FA) is an inherited disease with congenital abnormalities and an extreme risk of acute myeloid leukemia (AML). Genetic events occurring during malignant transformation in FA and the biology of FA‐associated AML are poorly understood, but are often preceded by the development of chromosomal aberrations involving 3q26‐29 in bone marrow of FA patients. We report here the molecular cytogenetic characterization of FA‐derived AML cell lines SB1685CB and SB1690CB by conventional and array comparative genomic hybridization, fluorescence in situ hybridization, and SKY. We identified gains of a 3.7 MB chromosomal region on 3q26.2‐26.31, which preceded transformation to overt leukemia. This region harbors the oncogenic transcription factor EVI1. A third FA‐derived cell line, FA‐AML1, carried a translocation with ectopic localization of 3q26 including EVI1. Rearrangements of 3q, which are rare in childhood AML, commonly result in overexpression of EVI1, which determines specific gene expression patterns and confers poor prognosis. We detected overexpression of EVI1 in all three FA‐derived AML. Our results suggest a link between the FA defect, chromosomal aberrations involving 3q and overexpression of EVI1. We hypothesize that constitutional or acquired FA defects might be a common factor for the development of 3q abnormalities in AML. In addition, cryptic imbalances as detected here might account for overexpression of EVI1 in AML without overt 3q26 rearrangements. © 2007 Wiley‐Liss, Inc.
Effects of ERBB2 amplicon size and genomic alterations of chromosomes 1, 3, and 10 on patient response to trastuzumab in metastatic breast cancer
Authors: Morrison Larry E. , Jewell Susan S. , Usha Lydia , Blondin Beth A. , Rao Ruta D. , Tabesh Bita , Kemper Matthew , Batus Marta , Coon John S.
Published: January 2007

Trastuzumab is widely used for advanced breast cancer patients with ERBB2‐amplified tumors. Nevertheless, over half of these patients do not have an objective response. One reason may be altered expression of genes that might compensate for ERBB2 inhibition. We previously mapped the gene‐rich region of chromosome 17 telomeric to ERBB2, and reported considerable variability in the telomeric extent of the ERBB2 amplicon. Here we examined whether the variable amplicon size may be associated with patient response to trastuzumab. In addition, we looked at associations between response and several signaling pathway‐related genes unrelated to the ERBB2 amplicon, including AKT3, PTEN, PIK3CA, and PTGS2. In 35 patients with ERBB2‐amplified metastatic breast cancer, with 40% overall response to trastuzumab, fluorescence in situ hybridization identified the telomeric extent of the ERBB2 amplicon and the status of the several pathway‐related genes. Objective response strongly correlated with the telomeric amplicon size, with 62% of patients with shorter amplicons responding, compared with only 7% of patients with longer amplicons (P = 0.0015). Abnormal copy number of PTGS2 was marginally associated with objective response (P = 0.066), while abnormal copy numbers of two reference loci, 1q25 and the chromosome 10 centromere, were significantly associated with response. Pairwise combinations of copy number status of these loci and ERBB2 amplicon size provided stronger associations and identified a group of patients without responders. These results suggest that patient selection for trastuzumab may be improved by considering ERBB2 amplicon size and genomic status of the 1q25, PTGS2, and centromere 10 loci. © 2007 Wiley‐Liss, Inc.
Comprehensive analysis of tumoral DNA content reveals clonal ploidy heterogeneity as a marker with prognostic significance in locoregional neuroblastoma
Authors: Mora Jaume , Lavarino Cinzia , Alaminos Miguel , Cheung Nai‐Kong V. , Ríos José , Torres Carmen de , Illei Peter , Juan Gloria , Gerald William L.
Published: January 2007

The clinical management of locoregional neuroblastoma (LR NB) is controversial. In a previous study we showed that diploidy was a strong prognostic predictor of outcome and detected the existence of clonal ploidy heterogeneity in a select group of cases. The aims of this study were (1) to assess the frequency of ploidy heterogeneity in LR NB, (2) to ascertain the best method to detect heteterogeneity, and (3) to correlate ploidy populations with clinical outcome. We undertook a comprehensive analysis of tumoral DNA content in 38 LR NBs comparing (1) flow cytometry (FCM), (2) karyotyping, (3) interphase fluorescence in situ hybridization, and (4) laser‐scanning cytometry (LSC). Tumor ploidy heterogeneity was found by all methodologies. By FCM, all tumors with aneuploid peaks had detectable diploid DNA peaks. By LSC, all tumors with diploid and hyperploid peaks were GD2‐positive in both, consistent with their tumoral origin. A predominant near‐triploid clonal population (ratio diploid vs. triploid, <2.5) was observed in most nonprogressing LR NB tumors, and a predominant diploid clone (ratio di‐ vs. triploid, >2.5) in most progressing LR NB cases. Multivariate analysis was performed to evaluate the prognostic value of tumor ploidy assayed by different methods versus age, INSS (International Neuroblastoma Staging System) stage, and MYCN status. FCM was the most powerful prognostic factor related to poor prognosis (overall survival, P = 0.02; progression‐free survival, P = 0.01). These results provide strong evidence for clonal ploidy heterogeneity in LR NB and clonal evolution toward diploidy in progressing LR NB. © 2007 Wiley‐Liss, Inc.
Patient preferences for managing asthma: results from a discrete choice experiment
Authors: King Madeleine T. , Hall Jane , Lancsar Emily , Fiebig Denzil , Hossain Ishrat , Louviere Jordan , Reddel Helen K. , Jenkins Christine R.
Published: January 2007

Effective control of asthma requires regular preventive medication. Poor medication adherence suggests that patient preferences for medications may differ from the concerns of the prescribing clinicians. This study investigated patient preferences for preventive medications across symptom control, daily activities, medication side‐effects, convenience and costs, using a discrete choice experiment embedded in a randomized clinical trial involving patients with mild–moderate persistent asthma. The present data were collected after patients had received 6 weeks' treatment with one of two drugs. Three choice options were presented, to continue with the current drug, to change to an alternative, hypothetical drug, or to take no preventive medication. Analysis used random parameter multinomial logit. Most respondents chose to continue with their current drug in most choice situations but this tendency differed depending on which medication they had been allocated. Respondents valued their ability to participate in usual daily activities and sport, preferred minimal symptoms, and were less likely to choose drugs with side‐effects. Cost was also significant, but other convenience attributes were not. Demographic characteristics did not improve the model fit. This study illustrates how discrete choice experiments may be embedded in a clinical trial to provide insights into patient preferences. Copyright © 2007 John Wiley & Sons, Ltd.
Molecular basis of vanadium‐mediated inhibition of hepatocellular preneoplasia during experimental hepatocarcinogenesis in rats
Authors: Chakraborty Tridib , Swamy A.H.M. Viswanatha , Chatterjee Amrita , Rana Basabi , Shyamsundar A. , Chatterjee Malay
Published: January 2007

Carcinogen‐induced early DNA lesions and metallothionein (MT) over‐expression have been implicated in cell proliferation and thereby subsequent expression of premalignant phenotype of the cell. We have therefore investigated the chemopreventive potential of vanadium in a multi‐biomarker approach, viz. 8‐hydroxy‐2′‐deoxyguanosines (8‐OHdGs), DNA single‐strand breaks (SSBs), DNA‐protein crosslinks (DPCs), chromosomal aberrations (CAs), in situ MT expression, and cell proliferation in rat liver preneoplasia. Hepatocarcinogenesis was induced in male Sprague–Dawley rats with a single, necrogenic, intraperitoneal (i.p.) injection of diethylnitrosamine (DEN) (200 mg/Kg body weight) at week 4 of the experimental protocol followed by promotion with phenobarbital (PB) (0.05% in basal diet), on and from week 8 and continued till 32 weeks in a long‐term regimen. There was a significant and steady elevation of modified DNA bases 8‐OHdGs (P < 0.0001; 90.69%) along with substantial increments of the extent of SSBs (P < 0.001) and CAs (P < 0.001) following DEN exposure. Supplementation of vanadium at a dose of 0.5 ppm abated the formations of 8‐OHdGs (80.63%; P < 0.0001), SS‐DNAs (P < 0.001) and SSBs/DNA unit (P < 0.01; 56.39%), DPCs (59.26%; P < 0.0001) and CAs (71.52%; P < 0.001) in preneoplastic rat liver studied at various time points. Low dose of vanadium treatment further reduced liver‐MT immunoreactivity (P < 0.05) and BrdU‐labeling index (P < 0.02) and a significant positive correlation (r = 0.92; r2 = 0.85; P = 0.0001) was noted between them. Continuous vanadium administration also decreased nodular incidence (66.67%) and nodule multiplicity (62.12%; P < 0.001) along with substantial improvement in the altered hepatocellular phenotype when compared to DEN + PB treatment alone. The study indicates that vanadium‐mediated suppression of cell proliferation and resulting premalignant expression might be due to the observed reductions in hepatic 8‐OHdGs, SSBs, DPCs, CAs, and MT immunoreactivity. Vanadium is chemopreventive for DEN‐induced hepatocellular preneoplasia in rats. J. Cell. Biochem. 101: 244–258, 2007. © 2007 Wiley‐Liss, Inc.
Pay high in good times, pay low in bad times
Authors: Schröder Michael , Heinemann Friedrich , Kruse Susanne , Meitner Matthias
Published: January 2007

The paper examines the applicability of GDP‐linked bonds for the financing of developing countries. These bonds are characterised by tying the coupon and/or redemption payments to the GDP of the issuing country. Along with an analysis of their pricing behaviour and of their behaviour in a portfolio context, the study also encompasses a survey amongst financial experts in order to assess the prospects of success of this type of bond. Finally, the usefulness of a partial public guarantee of payments is examined. The paper provides evidence under which circumstances, for which investors and for which countries, GDP‐linked bonds might be an appropriate investment vehicle. Copyright © 2007 John Wiley & Sons, Ltd.
Chemoenzymatic n.c.a synthesis of the coenzyme UDP‐2‐deoxy‐2‐[18F]fluoro‐α‐D‐glucopyranose as substrate of glycosyltransferases
Authors: Prante Olaf , Hamacher Kurt , Coenen Heinz H.
Published: January 2007

The development of 18F‐labelling methods adopted to proteins and bioactive peptides is of great interest in radiopharmaceutical sciences. In order to provide 18F‐labelled sugars as a polar prosthetic group for an enzymatic 18F‐labelling procedure, an appropriate nucleotide activated sugar is needed. Here, we present the radiosynthesis of n.c.a. UDP‐2‐deoxy‐2‐[18F]fluoro‐α‐D‐glucopyranose (UDP‐[18F]FDG) as a substrate for glycosyltransferases. The MacDonald synthesis of [18F]FDG‐1‐phosphate was successfully combined with an enzymatic activation to obtain UDP‐[18F]FDG directly in an aqueous medium located in the void volume of a solid phase cartridge. The radiochemical yield of UDP‐[18F]FDG was 20% (based on [18F]fluoride) after a total synthesis time of 110 min. Thus, an intermediate was provided for the enzymatic transfer of [18F]FDG using UDP‐[18F]FDG as glycosyl donor making use of a suitable glycosyltransferase. This would represent a highly selective and mild 18F‐labelling method for glycosylated biomolecules. Copyright © 2007 John Wiley & Sons, Ltd.
Liquid chromatography‐mass spectrometry method for quantification of caspofungin in clinical plasma samples
Authors: Rochat Bertrand , Bolay Saskia , Pascual Andres , Calandra Thierry , Marchetti Oscar
Published: January 2007

Caspofungin [(CASPO) MK‐0991] is the first broad‐spectrum anti‐fungal agent of the echinocandin class approved for clinical use. Measurement of CASPO levels in blood might help monitor therapy in patients who are critically ill, in particular, if high‐dose regimens or combinations of CASPO with other anti‐fungals are used. The objective of this study was to develop a fast method for the measurement of CASPO levels in clinical blood samples using liquid chromatography coupled to a triple‐quadrupole mass spectrometer. Stock solutions were prepared in plasma to avoid CASPO adsorption to glass and plastic surfaces during processing. CASPO and the internal standard (IS) were extracted from 100 µl of plasma using acetonitrile protein precipitation. The supernatant was diluted and directly injected into an analytical column (C8; 2.1 × 30 mm). The total run time was 15 min. CASPO was ionized by electrospray in the positive mode. CASPO and IS [M + 2H]2+ parent ions (m/z 547.3 and 547.8, respectively) and specific product ions (m/z 137.1 and 62.2, respectively) were used for the ion transitions. No carry over or cross‐talk was observed on the column. The mean method recovery was 90 ± 3%. Neither blood from different individuals (n = 6) nor the presence of concomitant drugs (n = 33) in plasma samples interfered with CASPO quantification. Quantification over time of the CASPO levels in plasma and whole blood was investigated at different pre‐analysis storage conditions. The calibration curve included the clinically relevant CASPO concentration range from 0.04 to 20 µg/ml. Mean intra‐ and inter‐day accuracy was 96.1 ± 2.2% and 102.5 ± 2.4%, respectively. Mean intra‐ and inter‐day precision was 7.9 ± 3.2% and 6.3 ± 1.8%, respectively. This simple and robust liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method may easily be implemented for monitoring CASPO therapy. Copyright © 2007 John Wiley & Sons, Ltd.
Apoptotic and behavioral sequelae of mild brain trauma in mice
Authors: Tweedie David , Milman Anat , Holloway Harold W. , Li Yazhou , Harvey Brandon K. , Shen Hui , Pistell Paul J. , Lahiri Debomoy K. , Hoffer Barry J. , Wang Yun , Pick Chaim G. , Greig Nigel H.
Published: January 2007

Mild traumatic brain injury (mTBI) is a not uncommon event in adolescents and young adults. Although it does not result in clear morphological brain defects, it is associated with long‐term cognitive, emotional, and behavioral problems. Herein, we characterized the biochemical and behavioral changes associated with experimental mTBI in mice that may act as either targets or surrogate markers for interventional therapy. Specifically, mTBI was induced by 30‐g and 50‐g weight drop, and at 8 and 72 hr thereafter markers of cellular apoptosis—caspase‐3, Bax, apoptosis‐inducing factor (AIF), and cytochrome‐c (Cyt‐c)—were quantified by Western blot analysis in hippocampus ipsilateral to the impact. Levels of amyloid‐β precursor protein (APP) were also measured, and specific behavioral tests—passive avoidance, open field, and forced swimming (Porsolt) paradigms—were undertaken to assess learning, emotionality, and emotional memory. In the absence of hemorrhage or infarcts, as assessed by triphenyltetrazolium chloride staining, procaspase‐3 and Bax levels were markedly altered following mTBI at both times. No cleaved caspase‐3 was detected, and levels of AIF and Cyt‐c, but not APP, were significantly changed at 72 hr. Mice subjected to mTBI were indistinguishable from controls by neurological examination at 1 and 24 hr, and by passive avoidance/open field at 72 hr, but could be differentiated in the forced swimming paradigm. In general, this model mimics the diffuse effects of mTBI on brain function associated with the human condition and highlights specific apoptotic proteins and a behavioral paradigm as potential markers for prospective interventional strategies. © 2007 Wiley‐Liss, Inc.
Mitochondria in cybrids containing mtDNA from persons with mitochondriopathies
Authors: Swerdlow Russell H.
Published: January 2007

The cytoplasmic hybrid (cybrid) technique allows investigators to express selected mitochondrial DNA (mtDNA) sequences against fixed nuclear DNA (nDNA) backgrounds. Cybrids have been used to study the effects of known mtDNA mutations on mitochondrial biochemistry, mtDNA‐nDNA inter‐species compatibility, and mtDNA integrity in persons without mtDNA mutations defined previously. This review discusses events leading up to creation of the cybrid technique, as well as data obtained via application of the cybrid strategies listed above. Although interpreting cybrid data requires awareness of technique limitations, valuable insights into mtDNA genotype‐functional phenotype relationships are suggested. © 2007 Wiley‐Liss, Inc.
Excitotoxic motoneuron disease in chick embryo evolves with autophagic neurodegeneration and deregulation of neuromuscular innervation
Authors: Calderó Jordi , Tarabal Olga , Casanovas Anna , Ciutat Dolors , Casas Celia , Lladó Jerònia , Esquerda Josep E.
Published: January 2007

In the chick embryo, in ovo application of NMDA from embryonic day (E) 5 to E9 results in selective damage to spinal cord motoneurons (MNs) that undergo a long‐lasting degenerative process without immediate cell death. This contrasts with a single application of NMDA on E8, or later, which induces massive necrosis of the whole spinal cord. Chronic MN degeneration after NMDA implies transient incompetence to develop programmed cell death, altered protein processing within secretory pathways, and late activation of autophagy. Chronic NMDA treatment also results in an enlargement of thapsigargin‐sensitive Ca2+ stores. In particular MN pools, such as sartorius‐innervating MNs, the neuropeptide CGRP is accumulated in somas, peripheral axons and neuromuscular junctions after chronic NMDA treatment, but not in embryos paralyzed by chronic administration of curare. Intramuscular axonal branching is also altered severely after NMDA: it usually increases, but in some cases a marked reduction can also be observed. Moreover, innervated muscle postsynaptic sites increase by NMDA, but to a lesser extent than by curare. Because some of these results show interesting homologies with MN pathology in human sporadic ALS, the model presented here provides a valuable tool for advancing in the understanding of some cellular and molecular processes particularly involved in this disease. © 2007 Wiley‐Liss, Inc.
Objective air temperature mapping for the Iberian Peninsula using spatial interpolation and GIS
Authors: Ninyerola Miquel , Pons Xavier , Roure Joan M.
Published: January 2007

This study presents an objective mapping of monthly mean air temperature over the Iberian Peninsula using the spatial interpolation of climatological data. The research focuses on an interpolation method (multiple regression with residual correction) that combines statistical global analysis with a local interpolation (splines and inverse distance weighting). Geographical information (the independent variables) is used to predict air temperature (the dependent variable) through the regression relationship and to test several approaches. A comprehensive GIS implementation makes it possible to address many cartographic issues and to produce mean minimum, mean and mean maximum air temperature surfaces for the entire Iberian Peninsula. The spatial resolution of the maps is 200 m and their temporal resolution is monthly and annual. An associated error level obtained through validation tests with independent data is computed for each map. These validation tests show that the best results have an average R2 (mean of all months) of 0.91 (mean temperature), 0.87 (mean maximum temperature) and 0.83 (mean minimum temperature). When the objective is to map a large area, best results are obtained when the model uses all stations of the Iberian Peninsula together (general peninsular model) and not when using different local subsets (hydrographical basins regional models). However, when the objective is mapping a regional area, basin models produce better outcomes than the general model being applied to these regional areas. Copyright © 2007 Royal Meteorological Society
Synchronization between the North Sea–Caspian pattern (NCP) and surface air temperatures in NCEP
Authors: Tatli Hasan
Published: January 2007

In this study, synchronous linkages of the North Sea–Caspian pattern (NCP), associated with large‐scale surface air temperature series selected from National Centers for Environmental Prediction–National Center of Atmospheric Research reanalysis (NCEP‐NCAR) for the region over 50°W–120°E and 0–80°N are investigated via teleconnection patterns based on phase synchronization. Phase synchronization is the process by which two or more cyclic systems (or subsystems) tend to oscillate with a repeating sequence of relative phase angles. Phase synchronization is usually applied to two waveforms of the same frequency with identical phase angles in each cycle. However, the notion of phase synchronization has been introduced as an extension of classical Huygens' synchronization in the case of interacting chaotic systems if there is an integer relationship of frequency, such that the cyclic systems share a repeating sequence of phase angles over consecutive cycles. The results of the phase synchronization method are compared with those of the classical cross‐correlation method in cases in which cross‐correlation method shows linear spatial cross‐dependency, but the phase synchronization yields nonlinear spatial phase dependency. In the analyses, teleconnection patterns derived from phase synchronization are first calculated for raw and de‐seasoned data (by removing periodic components in the surface air temperature series) in year‐month scale and then for the data in seasonal‐scale (namely, winter, spring, summer and autumn). Teleconnection patterns calculated by phase synchronization improve the experiential intra‐phase relationships between the NCP Index (NCPI) and large‐scale surface air temperature series, and ensures that the major modes of mid and high Northern Hemisphere variability in climate are characterized. Statistically significant phase synchronization patterns related to geopotential dipole heights of the NCPI extending over Greenland, the Balkans, Caspian Sea basin, eastern Mediterranean, Turkey and the Middle East, and further phase synchronization patterns over the circumpolar mode, which are utilized by phase interaction of Arctic oscillation (AO) with NCP, are obtained. In addition, significant phase synchronization patterns are also obtained over Tibetan plateau–Mongolia (Gobi Desert) interacting with the Siberian high, Asiatic monsoon and the intertropical convergence zone. Copyright © 2007 Royal Meteorological Society
Comprehensive analysis of the climate variability in the eastern Mediterranean. Part I: map‐pattern classification
Authors: Kostopoulou E. , Jones P. D.
Published: January 2007

This paper provides an extended study of the dominant daily circulation patterns governing the climate variability in the eastern Mediterranean. The methodology adopted to determine the circulation patterns is based on combined analysis of the spatial and temporal variation of rotated principal components of sea‐level pressure. A catalogue of characteristic seasonal composites is presented and discussed. It is found that, during winter and spring, large scale features situated in northern Europe affect the atmospheric circulation over the domain of study, whereas the Atlantic (Azores) anticyclone and the Asian Thermal Low define most of the observed circulation types in summer. In autumn, the area exhibits a rapid transition from the warm to cold season showing climatic features from both extreme seasons. Similarities between winter and spring/autumn patterns are detected and correlation analyses are employed between their spatial patterns to reveal that similar circulation patterns occur amongst the three seasons, which usually appear more pronounced during winter. Frequencies and trends of the proposed circulation types are examined for each season. A linear trend analysis for the overall period (1958–2000) exhibits a significant increase in the anticyclonic types particularly in winter. With respect to the cyclonic types, statistically significant negative trends have been found in all seasons especially for types associated with depressional activity in central the Mediterranean. Copyright © 2007 Royal Meteorological Society
Analysis of soil organic matter biomarkers by sequential chemical degradation and gas chromatography – mass spectrometry
Authors: Otto Angelika , Simpson Myrna J.
Published: January 2007

Low molecular weight (LMW) biomarkers can be used to trace the source and stage of soil organic matter. However, methods that selectively isolate these groups of compounds are underdeveloped. In this study, we isolate biomarkers by a successive series of extraction and chemical degradation procedures involving solvent extraction (TSE), base (BHY) and acid hydrolysis (AHY), and CuO oxidation (CUO). GC‐MS was used to analyze these fractions and the extraction methods were verified by solid‐state 13C NMR spectroscopy. The GC‐MS response was high for the BHY products (96%), intermediate for the TSE (30%) and CUO (19%), but very low for the AHY fraction (5%) indicating that the fractions contain polar or high molecular weight compounds. Aliphatic lipids (62%), phenols and benzyls (17%) were the predominant classes, accompanied by minor abundances of mono‐ and disaccharides, LMW acids, terpenoids, steroids, amino acids, and amino sugars. The TSE and BHY fractions contained mainly aliphatic lipids derived from plant waxes, cutin, and suberin. Lignin‐derived phenols are the major products in the CUO fraction, and amino compounds and carbohydrates of various sources were identified in the AHY products. The sequential degradation method is useful for the isolation and identification of apolar, LMW biomarkers in soil.
Quantification of testosterone and epitestosterone in human urine samples by stir bar sorptive extraction – thermal desorption – gas chromatography/mass spectrometry: Application to HIV‐positive urine samples
Authors: Stopforth Adriana , Grobbelaar Cornelis J. , Crouch Andrew M. , Sandra Pat
Published: January 2007

A simple method is described for the measurement of testosterone (T) and epitestosterone (ET) in human urine samples. The deconjugated steroids were extracted directly from the samples by stir bar sorptive extraction (SBSE) and derivatized in situ on the stir bar by headspace acylation prior to thermal desorption and GC/MS. Extraction and derivatization parameters, namely salt addition, temperature, and time, were optimized to improve the recovery of T and ET by SBSE. The limits of quantification (S/N 10) were 0.9 ng/mL for T and 2.8 ng/mL for ET. Quantification of the steroids in urine samples was performed using standard addition to avoid the influence of matrix effects. The method was applied for the measurement of urinary T and ET in a group of healthy volunteers and HIV+ patients. Decreased levels of T were detected in the HIV+ group, whereas the excretion of ET was comparable for the two groups. Further clinical research is required to elucidate the biomarker significance of the T/ET ratio in HIV infection.
Identification of neuropeptides in rat brain rhinencephalon
Authors: Mihailova Albena , Karaszewski Bartosz , Hauser Roman , Lundanes Elsa , Greibrokk Tyge
Published: January 2007

A capillary two‐dimensional liquid chromatography method coupled with ion trap mass spectrometry has been used for separation and identification of neuropeptides in rat rhinencephalon. Animals of three different age groups were exposed to slow and quick CO2 influx. The neuropeptides were extracted by solid phase extraction and the purified extracts were analysed by 2‐D HPLC. The compounds were fractionated (strong cation exchange column), trapped and separated, and MS/MS fragment mass spectra were used for identification. About thirty peptide compounds were identified. A significant difference between concentration levels of “stressed” (quick CO2 influx) and “non‐stressed” (slow CO2 influx) rats was found for 25 of the identified peptides.
Solution Behavior of Temperature‐Responsive Molecular Brushes Prepared by ATRP
Authors: Pietrasik Joanna , Sumerlin Brent S. , Lee Robert Y. , Matyjaszewski Krzysztof
Published: January 2007

Molecular brushes, with side chains consisting of two copolymers: 2‐(dimethylamino)ethyl methacrylate with methyl methacrylate, and N,N‐dimethylacrylamide with butyl acrylate were prepared by grafting‐from via atom transfer radical polymerization (ATRP). Poly(2‐(2‐bromoisobutyryloxy)ethyl methacrylate) and poly(2‐(2‐bromopropionyloxy)ethyl methacrylate) were used as macroinitiators. Dynamic light scattering (DLS) studies were performed for aqueous solutions of molecular brushes below and above the lower critical solution temperature (LCST), and an unusual concentration‐dependent LCST was observed. Due to the compact structure of molecular brushes, intramolecular collapse can occur when the average distance between molecules is much larger than the hydrodynamic dimensions of the individual macromolecules. However, if the concentration of the solution of molecular brushes is increased to the level in which the separation distance is comparable with the brush hydrodynamic dimensions, intermolecular aggregation occurs, as typically observed for solutions of linear polymers.

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Improvement of the Mechanical Properties and Creep Resistance of SBS Block Copolymers by Nanoclay Fillers
Authors: Lietz Siljana , Yang Jing‐Lei , Bosch Eva , Sandler Jan K. W. , Zhang Zhong , Altstädt Volker
Published: January 2007

SBS nanocomposites based on a SBS triblock copolymer containing different weight fractions of a commercial Cloisite 20A organoclay were prepared by melt‐processing. Extensive electron microscopy as well as WAXS and static tensile and tensile creep tests were used to evaluate the resulting morphological and mechanical properties of the nanocomposites. The nanocomposite morphology is characterized by a combination of intercalated and partly exfoliated clay platelets with occasional clay aggregates present at higher clay contents; nanocomposite features that are reflected by the results of both the static tensile as well as the tensile creep tests at room temperature. For this particular thermoplastic elastomer nanocomposite system, well dispersed nanoclays lead to an enhanced stiffness and ductility; effects that induce promising improvements in nanocomposite creep performance.

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Water‐Soluble Electrostatic Complexes of C60‐Anchored Anionic Polymers and Cationic Porphyrins
Authors: Chu Chih‐Chien , Ho Tong‐Ing , Wang Leeyih
Published: January 2007

The preparation of novel highly water‐soluble electrostatic complexes from C60‐anchored multi‐armed poly(acrylic acid)s and cationic porphyrin derivatives was demonstrated. The UV‐vis absorption and photoluminescence (PL) of these complexes show that the absorption of soret band exhibits a remarkable red shift and the emission of the Q band indicates an apparent quenching effect in comparison with that of the parent cationic porphyrin. These results imply a remarkable ground state and excited state interaction between the porphyrin ring and the C60 moiety.

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‘Click’ Chemistry in Polymer and Materials Science
Authors: Binder Wolfgang H. , Sachsenhofer Robert
Published: January 2007

The modification of polymers after the successful achievement of a polymerization process represents an important task in macromolecular science. Cycloaddition reactions, among them the metal catalyzed azide/alkyne ‘click’ reaction (a variation of the Huisgen 1,3‐dipolar cycloaddition reaction between terminal acetylenes and azides) represents an important contribution towards this endeavor. They combine high efficiency (usually above 95%) with a high tolerance of functional groups and solvents, as well as moderate reaction temperatures (25–70 °C). The present review assembles recent literature for applications of this reaction in the field of polymer science (linear polymers, dendrimers, gels) as well as the use of this and related reactions for surface modification on carbon nanotubes, fullerenes, and on solid substrates, and includes the authors own publications in this field. A number of references (>100) are included.

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Poly(cyclooctene)s with Pendant Fluorescent and Phosphorescent Metal Complexes
Authors: Kimyonok Alpay , Weck Marcus
Published: January 2007

Poly(cyclooctene)s with pendant Alq3 and fac‐Ir(ppy)3 were synthesized. Carbazole‐based comonomers were used to increase the solubility of the polymers and to transfer the energy into metal complexes. Excitation spectra of all polymers provided evidence of energy transfer. We established that the polymer backbone does not interfere with the optical properties of the metal complexes. All copolymers retained the optical properties of their small molecule metal complex analogs in solution and the solid state, making these polymers promising materials for potential electro‐optical applications.

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Controlled Radical Polymerization of 2,3‐Epithiopropyl Methacrylate
Authors: Tebaldi de Sordi Marli Luiza , Ceschi Marco Antônio , Petzhold Cesar Liberato , Müller Axel H. E.
Published: January 2007

We report first results on the controlled radical polymerization of 2,3‐epithiopropyl methacrylate (ETMA) also known as thiiran‐2‐ylmethyl methacrylate. Reversible addition‐fragmentation chain transfer (RAFT) of ETMA was carried out in bulk and in solution, using AIBN as initiator and the chain transfer agents: cyanopropyl dithiobenzoate (CPDB) and cumyl dithiobenzoate (CDB). A linear increase of the number‐average molecular weight and decrease of the polydispersity with monomer conversion were observed using CPDB as transfer agent, indicating a controlled process. Atom transfer radical polymerization (ATRP) of ETMA was performed under different reaction conditions using copper bromide complexed by tertiary amine ligands and ethyl 2‐bromoisobutyrate (EBiB) or 2‐bromopropionitrile (BPN) as initiator. All experiments lead to a crosslinked polymer. Preliminary studies in the absence of initiator showed that the CuBr/ligand complex alone initiates the ring‐opening polymerization of thiirane leading to a poly(propylene sulfide) with pendant methacrylate groups.

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Photoinduced Crosslinking of Polymers Containing Pendant Hydroxyl Groups by Using Bisbenzodioxinones
Authors: Kumbaraci Volkan , Talinli Naciye , Yagci Yusuf
Published: January 2007

In the present study, it has been demonstrated that polymers containing pendant hydroxyl groups can undergo photoinduced crosslinking upon irradiation in the presence of bifunctional benzodioxinone. Irradiation of the copolymers of 2‐hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) in dichloromethane and THF solutions or in films containing bisbenzodioxinone, namely 5‐[9‐(4‐oxo‐2,2‐diphenyl‐4H‐benzo[d][1,3]dioxin‐5‐yloxy) nonyloxy]‐2,2‐diphenyl‐4H‐benzo[d][1,3]dioxin‐4‐one resulted in the formation of insoluble networks. Model studies using monofunctional napthodioxinone, namely 7‐hydroxy‐2,2‐diphenyl‐4H‐naphtho[2,3‐d][1,3]dioxin‐4‐one, revealed that crosslinking occurs via inter‐chain ester formation between photochemically generated keten intermediates and pendant hydroxyl groups.

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Fast Controlled Radical Polymerization of Styrene Mediated by Oligomeric Nitroxides Formed In Situ
Authors: Sciannamea Valérie , Catala Jean‐Marie , Jerome Robert , Detrembleur Christophe
Published: January 2007

In the presence of an oligomeric hindered secondary amine added with peracetic acid as the oxidant, radical polymerization of styrene is fast and controlled at 110 °C. Under these experimental conditions, an oligomeric nitroxide is formed in situ. This polymerization is 2.5 faster than polymerization mediated by the alkoxyamine derivated from TIPNO (2,2,5‐trimethyl‐4‐phenyl‐3‐azahexane‐3‐nitroxide), which generates a low molar mass nitroxide. Similarly, substitution of a low molar mass secondary amine, 2,2,6,6‐tetramethylpiperidone (4‐oxo‐TMP), for the oligomeric secondary amine maintains the control on the polymerization, which is however 4.6 times slower, all the other conditions being the same. The in situ formation of the oligomeric nitroxide has been confirmed by electron spin resonance (ESR).

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Cover Picture: Macromol. Rapid Commun. 2/2007
Authors: Park Eun Young , Kim Jun Woo , Ahn Dong June , Kim Jong‐Man
Published: January 2007

Cover: The cover shows a schematic representation and microscopic images of a conjugated polymer system that emits red, green and blue fluorescence. Red light emitting polydiacetylene vesicles can be readily prepared by self‐assembly of functional diacetylene monomers. Encapsulation of green‐fluorescent fluorescein molecules inside the polymer vesicle followed by attachment of fluorescamine to the surface amine moieties afforded a unique RGB‐emitting supramolecular system. Further details can be found in the article by E. Y. Park, J. W. Kim, D. J. Ahn, and J.‐M. Kim* on page 171.
Investigation and Modeling of Temperature Dependence Recovery Behavior of Shape‐Memory Crosslinked Polyethylene
Authors: Khonakdar Hossein Ali , Jafari Seyed Hassan , Rasouli Sorour , Morshedian Jalil , Abedini Hossein
Published: January 2007

Shape memory was induced in crosslinked low‐density polyethylene by a heating‐stretching‐cooling cycle. The effect of crosslink content on thermal properties and temperature dependence recovery behavior was studied experimentally. The importance of stretching temperature and crosslink content on recovery behavior could be reasonably explained by the observed changes in the thermal properties which were attributed to the differences in crystalline structures and mechanism of crystal formation during the heating‐stretching‐cooling process. A mechanical model was developed to describe qualitatively and quantitatively the temperature dependence recovery behavior of the prepared shape memory crosslinked polyethylene at nonisothermal state under various conditions by driving constitutive equations using a set of model constants. These model constants were determined with the help of a set of optimization codes using a genetic algorithm method. By choosing a suitable set of model constants one can describe with high accuracy the temperature dependence recovery behavior of any shape memory polymer.

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