bluuebunny/crossref_metadata_2025 huggingface dataset:
HMGB1: The jack‐of‐all‐trades protein is a master DNA repair mechanic
Authors: Lange Sabine S. , Vasquez Karen M.
Published: April 2009

The high mobility group protein B1 (HMGB1) is a highly abundant protein with roles in several cellular processes, including chromatin structure and transcriptional regulation, as well as an extracellular role in inflammation. HMGB1's most thoroughly defined function is as a protein capable of binding specifically to distorted and damaged DNA, and its ability to induce further bending in the DNA once it is bound. This characteristic in part mediates its function in chromatin structure (binding to the linker region of nucleosomal DNA and increasing the instability of the nucleosome structure) as well as transcription (bending promoter DNA to enhance the interaction of transcription factors), but the functional consequences of HMGB1's binding to damaged DNA is still an area of active investigation. In this review we describe HMGB1's actions in the nucleotide excision repair (NER) pathway, and we discuss aspects of both the “repair shielding” and “repair enhancing” hypotheses that have been suggested. We also report information regarding HMGB1's roles in the mismatch repair (MMR), nonhomologous end‐joining (NHEJ), and V(D)J recombination pathways, as well as its newly‐discovered involvement in the base excision repair (BER) pathway. We further explore the potential of HMGB1 in DNA repair in the context of chromatin. The elucidation of HMGB1's role in DNA repair is critical for the complete understanding of HMGB1's intracellular functions, which is particularly relevant in the context of anti‐HMGB1 therapies that are being developed to treat inflammatory diseases. © 2009 Wiley‐Liss, Inc.
The traffic problem: Modeling of the overtaking
Authors: Buřič Lubor , Janovský Vladimír
Published: April 2009

The classical microscopic single line follow‐the‐leader model of a road traffic may collapse in finite time due to a car collision. In order to avoid the collision, the natural action of a driver would be to overtake the slower car. We propose a simple model of overtaking assuming a circular road. The model is a dynamical system with discontinuous right‐hand side (the Filippov system). As a case study, we assumed that the system consists of N =3 identical cars. We studied a particular periodic solution (oscillatory pattern). We explored the possibility to use the standard software (AUTO97) to continue the pattern with respect to a parameter. Copyright © 2009 John Wiley & Sons, Ltd.
Review on sample preparation strategies and methods used for the analysis of aflatoxins in food and feed
Authors: Reiter Elisabeth , Zentek Jürgen , Razzazi Ebrahim
Published: April 2009

Mycotoxins are of toxicological relevance and consequently important contaminants in food and feed. The most common mycotoxins with the highest toxicity are the aflatoxins (AFs), which cause liver cirrhosis or primary liver carcinomas and have been shown to be the immunosuppressive. The European Union has set the maximum levels as low as reasonably achievable to protect consumers. To perform appropriate risk assessment for AFs robust analytical methods are required to provide reliable results. Different steps in the analysis of AFs in food and feed are necessary such as sampling, extraction, sample purification and detection. Throughout the analysis chain, methods have to be precise and reproducible. The sensitivity of an analysis, especially if the detection is not selective enough depends strongly on the sample clean up. However, techniques in sample preparation and analytical methods are improving continuously. This manuscript gives an overview on different analytical methods with emphasize on sample preparation strategies used in the analysis of AFs in food and feed.
The Fusarium toxin enniatin B exerts no genotoxic activity, but pronounced cytotoxicity in vitro
Authors: Behm Claudia , Degen Gisela H. , Föllmann Wolfram
Published: April 2009

Enniatin B, a fungal metabolite produced by various Fusarium strains, is a frequent contaminant in cereals used for human foods and animal feeds, but, so far very limited data are available on its toxicity. The aim of this study was to investigate the effects of enniatin B in a battery of short‐term tests to evaluate its genotoxic potential. In Salmonella typhimurium assays (Ames assay) with the strains TA 98, TA 100, TA 102, and TA 104, both in the presence and absence of an external metabolizing enzyme system (rat liver S9), no mutagenicity was detected up to toxic levels (100 μM) of enniatin B. Likewise, mutagenicity tests in mammalian cells, i. e., the hypoxanthin‐guanin‐phosphoribosyl‐transferase (HPRT) assay with V79 cells performed with and without S9 mix, did not reveal a significant increase in mutant frequency for enniatin B up to 30 μM, a cytotoxic concentration. Additional tests on other types of genotoxicity, i. e., clastogenicity and chromosomal damage, were conducted in V79 cells, applying the alkaline single cell gel electrophoresis (Comet assay with and without FPG, formamidopyrimidine DNA glycosylase, enzyme) and the micronucleus assay. None of these assays revealed a significant genotoxic potential of enniatin B. However, enniatin B exerts pronounced cytotoxic effects in V79 cells as determined by neutral red uptake assay for 48 h exposure: The IC20 and IC50 values of 1.5 and 4 μM, are higher than those of the more potent Fusarium toxin deoxynivalenol (IC20 0.6 μM, IC50 of 0.8 μM), but in a similar range as values reported for cytotoxicity of enniatin B in various tumor cell lines. In summary, despite an apparent lack of genotoxic activity, enniatin B can exert biological activity at low micromolar concentrations in mammalian cells.
Potential of deoxynivalenol to induce transcription factors in human hepatoma cells
Authors: Nielsen Carina , Lippke Harald , Didier Andrea , Dietrich Richard , Märtlbauer Erwin
Published: April 2009

To assess the hepatotoxicity of deoxynivalenol (DON), human hepatoma cells (Hep‐G2) were used as an in vitro model. After exposing Hep‐G2 cells to low (1 μM) and high dose (10 μM), gene expression profiles were analysed by microarray. More than 5% of genes were up‐regulated, most of them being involved in transcriptional regulation. By real‐time RT‐PCR, elevated expression of transcription factors, commonly induced by activation of MAPK‐pathway, was demonstrated for Hep‐G2 cells on mRNA and protein level. Further studies, involving U937 human monocytes, showed that effects of DON treatment on mRNA and protein level were concentration‐dependent and cell‐specific. An inverse relation was noticed for the level of DON induced expression of transcription factors (JUN, FOS, EGR1 and ATF3) and the susceptibility of the cell lines towards the mycotoxin. This is the first report giving evidence that on a molecular level the mild hepatotoxic effects of DON are probably caused by the induction of transcription factors which are known to be associated with injury‐induced liver regeneration processes. With ATF3, a novel downstream target gene was identified in DON‐related cell signalling suggesting a potential linkage between molecular action and biological effects like reduction of glycogen storage in liver tissue.
Palaeopathology in Britain: a critical analysis of publications with the aim of exploring recent trends (1997–2006)
Authors: Park V. M. , Roberts C. A. , Jakob T.
Published: April 2009

This study collects data from three major journals and analyses them in order to assess the recent (1997–2006) nature of the study of palaeopathology within Britain. It considers the types of study published (case, population or method), whether findings are integrated with other data, the particular ‘theme’ that is considered (diet, activity patterns, etc) and the particular pathological condition focused upon (metabolic, dental, etc). The findings show there is a move away from the traditional case study and an increase in the acknowledgement of the value of integrating data with wider information. There is also a bias towards certain ‘themes’ and pathologies, reasons for which are discussed. Copyright © 2009 John Wiley & Sons, Ltd.
An efficient microwave‐assisted extraction process of stevioside and rebaudioside‐A from Stevia rebaudiana (Bertoni)
Authors: Jaitak Vikas , Bandna Bikram Singh , Kaul V. K.
Published: April 2009

Introduction

Stevioside and rebaudioside‐A are major low‐calorie diterpene steviol glycosides in the leaves of Stevia rebaudiana. They are widely used as natural sweeteners for diabetic patients, but the long extraction procedures required and the optimisation of product yield present challenging problems.

Objective

To develop a rapid and effective methodology for the extraction of stevioside and rebaudioside‐A from S. rebaudiana leaves and to compare yields using different extraction techniques.

Methodology

Dried and powdered leaves of S. rebaudiana were extracted by conventional, ultrasound and microwave‐assisted extraction techniques using methanol, ethanol and water as single solvents as well as in binary mixtures. Conventional cold extraction was performed at 25°C for 12 h while ultrasound extraction was carried out at temperature of 35 ± 5°C for 30 min. Microwave‐assisted extraction (MAE) was carried out at a power level of 80 W for 1 min at 50°C.

Results

MAE yielded 8.64 and 2.34% of stevioside and rebaudioside‐A, respectively, while conventional and ultrasound techniques yielded 6.54 and 1.20%, and 4.20 and 1.98% of stevioside and rebaudioside‐A, respectively.

Conclusion

A rapid and efficient method has been developed for the extraction of stevioside and rebaudioside‐A in optimum yields using MAE procedure. This method has the advantage of rapid extraction and fast screening of a large number of S. rebaudiana samples for assessment of planting material. MAE saves considerable time, energy and has implications in the quality assessment of stevioside and rebaudioside‐A prior to their industrial production from the leaves of S. rebaudiana. Copyright © 2009 John Wiley & Sons, Ltd.
Fetal eyeball volume: relationship to gestational age and biparietal diameter
Authors: Odeh Marwan , Feldman Yulia , Degani Shimon , Grinin Vitali , Ophir Ella , Bornstein Jacob
Published: April 2009

Objective

To measure and determine normal values of the fetal eyeball volume between 14 and 40 weeks of gestation.

Methods

The volume of the fetal eyeball was measured with three‐dimensional ultrasound between 14 and 40 weeks of gestation using the VOCAL software.

Only singleton pregnancies without fetal growth restriction, diabetes mellitus, hypertension or major fetal malformation were included.

Results

Over all, 203 women were studied. In 125 both eyeballs were measured while in 78 only one eyeball was measured. The volume of the eyeball correlated strongly with gestational age (right: R = 0.946, P < 0.001, n = 171. left: R = 0.945, P < 0.001, n = 156), and with the biparietal diameter (BPD) (right: R = 0.949, P < 0.001, n = 171. left: R = 0.953, P < 0.001, n = 156). Using regression analysis the best correlation between eyeball volume and the BPD were: square of right eyeball = −0.180 + 0.187 BPD, square of left eyeball = −0.182 + 0.187 BPD.

Conclusions

The volume of the eyeball has strong positive correlations with gestational age and BPD. Our data may be helpful in fetuses suspected of having eye anomalies. Copyright © 2009 John Wiley & Sons, Ltd.
Facile and efficient preparation of phosphinate‐functionalized aromatic diamines and their high‐Tg polyimides
Authors: Chang Chia Wei , Hsuan Lin Ching , Wen Cheng Po , Hwang Hann Jang , Dai Shenghong A.
Published: April 2009

Two novel phosphorus‐functionalized aromatic diamines, 1,1‐bis(4‐aminophenyl)‐1‐(6‐oxido‐6H‐dibenz  <1,2> oxaphosphorin‐6‐yl)ethane (1) and bis(4‐aminophenyl)‐(6‐oxido‐6H‐dibenz  <1,2> oxaphosphorin‐6‐yl)phenylmethane (2), were prepared from 9,10‐dihydro‐oxa‐10‐phosphaphenanthrene‐10‐oxide, 4‐aminoacetophenone, or 4‐aminobenzophenone in excess aniline using p‐toluenesulfonic acid monohydrate as catalyst by an efficient, one‐pot procedure. The effect of electron withdrawing/donating groups on the stabilization of the resulting carbocation seems critical for the success of the process and was discussed in detail. Based on diamines (1–2), a series of new polyimides, (5a–5d) and (6a–6d), were prepared, respectively. Polyimides (5a–5d) are flexible and creasable. In contrast, polyimides (6a–6d) are brittle because of the structure rigidity, according to the analysis based on the NMR temperature‐dependent spectra of (2). Polyimides 5 displaying high Tg (318–392 °C), high moduli (3.39–4.49 GPa), low coefficient of thermal expansion (42–50 ppm/°C), and moderate thermal stability (Td 5 wt % at 426–439 °C), are excellent high‐Tg and flame‐retardant materials. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2486–2499, 2009
Chiral polyamides consisting of N‐α‐benzoyl‐L‐glutamic acid as a diacid component
Authors: Ikeuchi Yoshimi , Nakagawa Maiko , Yoshikawa Masakazu , Yoshida Hidekazu , Sakurai Shinichi
Published: April 2009

Novel polyamide with chiral environment was obtained from aromatic diamine, 4,4′‐diaminodiphenylmethane (DADPM), and N‐α‐protected L‐glutamic acid, N‐α‐benzoyl‐L‐glutamic acid (Benzoyl‐L‐Glu‐OH). The optical rotation ([α]D) of the polyamide was determined to be 3.6° (c = 1.00 g/dL in DMF), implying that the optically active polyamide was obtained. The present polyamide gave a durable self‐standing membrane. The membrane selectively incorporated the D‐isomer of Ac‐Trp from racemic mixture of Ac‐Trp. The adsorption selectivity toward Ac‐D‐Trp was determined to be 1.95. It showed chiral separation ability by adopting potential difference as a driving force for membrane transport. The permselectivity was dependent on the potential difference, and at the applied potential difference of 3.0 V, the membrane selectively transported Ac‐D‐Trp and the permselectivity toward Ac‐D‐Trp was determined to be 1.84, which was close to the adsorption selectivity of 1.95. Contrary to this, the membrane showed opposite permselectivity at the applied potential difference of 2.0 V and the permselectivity toward the L‐isomer reached 2.48. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2530–2538, 2009
Heterotactic‐specific radical polymerization of N‐isopropylacrylamide and phase transition behavior of aqueous solution of heterotactic poly(N‐isopropylacrylamide)
Authors: Hirano Tomohiro , Kamikubo Takahiro , Okumura Yuya , Bando Yoichi , Yamaoka Ryosuke , Mori Takeshi , Ute Koichi
Published: April 2009

Radical polymerization of N‐isopropylacrylamide (NIPAAm) in toluene at low temperatures, in the presence of fluorinated‐alcohols, produced heterotactic polymer comprising an alternating sequence of meso and racemo dyads. The heterotacticity reached 70% in triads when polymerization was carried out at −40 °C using nonafluoro‐tert‐butanol as the added alcohol. NMR analysis revealed that formation of a 1:1 complex of NIPAAm and fluorinated‐alcohol through CO···HO hydrogen bonding induces the heterotactic specificity. A mechanism for the heterotactic‐specific polymerization is proposed. Examination of the phase transition behavior of aqueous solutions of heterotactic poly(NIPAAm) revealed that the hysteresis of the phase transition between the heating and cooling cycles depended on the average length of meso dyads in poly(NIPAAm). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2539–2550, 2009
Vinyl addition polymerization of norbornene with cationic (allyl)Ni catalysts: Mechanistic insights and characterization of first insertion products
Authors: Walter Marc D. , Moorhouse Rebecca A. , White Peter S. , Brookhart Maurice
Published: April 2009

Several cationic (allyl)Ni(II) complexes were synthesized and shown to be highly active for (2,3)‐vinyl addition polymerization of norbornene to yield polymers with low molecular weight distributions (MWDs) ranging from 1.4–1.9. In all cases slow initiation was followed by rapid propagation which prevents molecular weight control of the poly(norbornene). One of the intermediates in the polymerization process has been identified and characterized by NMR spectroscopy as the first insertion product resulting from the insertion of norbornene into the NiC allyl bond in cis‐exo fashion. This insertion product was synthesized independently and NMR studies showed that the first insertion of norbornene into the NiC allyl bond is a reversible process. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2560–2573, 2009
Incorporating glycidyl methacrylate into block copolymers using poly(methacrylate‐ran‐styrene) macroinitiators synthesized by nitroxide‐mediated polymerization
Authors: Lessard Benoît , Marić Milan
Published: April 2009

Methyl methacrylate/styrene (MMA/S), ethyl methacrylate/styrene (EMA/S) and butyl methacrylate/styrene (BMA/S) feeds (>90 mol % methacrylate) were copolymerized in 50 wt % p‐xylene at 90 °C with 10 mol % of additional SG1‐free nitroxide mediator relative to unimolecular initiator (BlocBuilder®) to yield methacrylate rich copolymers with polydispersities $\overline{M}$w/$\overline{M}$n = 1.23–1.46. kpK values (kp = propagation rate constant, K = equilibrium constant) for MMA/S copolymerizations were comparable with previous literature, whereas EMA/S and BMA/S copolymerizations were characterized by slightly higher kpK's. Chain extensions with styrene at 110 °C initiated by the methacrylate‐rich macroinitiators (number average molecular weight $\overline{M}$n = 12.9–33.5 kg mol−1) resulted in slightly broader molecular weight distributions with $\overline{M}$w/$\overline{M}$n = 1.24–1.86 and were often bimodal. Chain extensions with glycidyl methacrylate/styrene/methacrylate (GMA/S/XMA where XMA = MMA, EMA or BMA) mixtures at 90 °C using the same macroinitiators resulted frequently in bimodal molecular weight distributions with many inactive macroinitiators and higher $\overline{M}$w/$\overline{M}$n = 2.01–2.48. P(XMA/S) macroinitiators ($\overline{M}$n = 4.9–8.9 kg mol−1), polymerized to low conversion and purified to remove “dead” chains, initiated chain extensions with GMA/MMA/S and GMA/EMA/S giving products with $\overline{M}$w/$\overline{M}$n ∼ 1.5 and much fewer unreacted macroinitiators (<5%), whereas the GMA/BMA/S chain extension was characterized by slightly more unreacted macroinitiators (∼20%). © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2574–2588, 2009
Synthesis of exact comb polybutadienes with two and three branches
Authors: Nikopoulou Anastasia , Iatrou Hermis , Lohse David J. , Hadjichristidis Nikos
Published: April 2009

Two methodologies, based on living star polymers and anionic polymerization high vacuum techniques, were used for the synthesis of exact comb polybutadienes (PBds) with two (C‐2 or H‐type) and three identical branches (symmetric, sC‐3, H‐type with an extra identical branch at the middle of the connector and asymmetric, aC‐3, H‐type with the extra identical branch at any other position along the connector). The first methodology involves (a) the selective replacement of the two chlorines of 4‐(dichloromethylsilyl)diphenylethylene (DCMSDPE, key molecule) with 3‐arm star PBds, by titration with identical (C‐2, sC‐3) or different (aC‐3) living 3‐arm star PBds, (b) the addition of s‐BuLi to the double bond of DPE, and (c) the polymerization of butadiene from the newly created anionic site (sC‐3, aC‐3).The second methodology involves the reaction of living stars with dichlorodimethylsilane (C‐2) or the selective replacement of the three chlorines of trichloromethylsilane with star and linear chains (sC‐3, aC‐3). Intermediate and final products were characterized via size exclusion chromatography, low angle laser light scattering and 1H‐NMR. The first methodology does not require fractionation, but in contrast to the second methodology, cannot afford polymers with branches of identical molecular weight. Both methods are general and can be extended to combs with two or three different branches at controllable positions along the backbone. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2597–2607, 2009
An efficient synthetic route to well‐defined theta‐shaped copolymers
Authors: Shi Gang‐Yin , Pan Cai‐Yuan
Published: April 2009

A series of well‐defined θ‐shaped copolymers composed of polystyrene (PS) and poly(ε‐caprolactone) (PCL) with controlled molecular weight and narrow molecular weight distribution have been successfully synthesized without any purification procedure by the combination of atom transfer radical polymerization (ATRP), ring‐opening polymerization (ROP), and the “click” chemistry. The synthetic process involves two steps: (1) synthesis of AB2 miktoarm star copolymers, which contain one PCL chain terminated with two acetylene groups and two PS chains with two azido groups at their one end, (α,α′‐diacetylene‐PCL) (ω‐azido‐PS)2, by ROP, ATRP, and the terminal group transformation; (2) intramolecular cyclization of AB2 miktoarm star copolymers to produce well‐defined pure θ‐shaped copolymers using “click” chemistry under high dilution. The 1H NMR, FTIR, and gel permeation chromatography techniques were applied to characterize the chemical structures of the resultant intermediates and the target polymers. Their thermal behavior was investigated by DSC. The mobility decrease of PCL chain across PS ring in the theta‐shaped copolymers restricts the crystallization ability of PCL segment. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2620–2630, 2009
Catalyst‐free synthesis of polyorganosiloxanes by high temperature and pressure water. II. Understanding of the reaction process
Authors: Ogawa Takuya , Watanabe Jun , Oshima Yoshito
Published: April 2009

A catalyst‐free polysiloxane synthetic process that uses high temperature and pressure water for the hydrolysis and subsequent polycondensation of phenyltrimethoxysilane was studied in detail to gain insights into the reaction mechanism. It was suggested that this process is essentially composed of two stages: (1) oligomerization of phenyltrimethoxysilane yielding low‐molecular weight species with high contents of silanol and methoxy groups and (2) polycondensation of the oligomers yielding high‐molecular weight species. The use of a preformed oligosiloxane as a starting material was informative to understand the polycondensation stage. A modified synthetic process in which a stop valve was introduced to control the internal pressure was developed based on the understanding of the present process. This modified process enabled a two‐stage reaction resulting in a discernible increase of the molecular weight of polysiloxane. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2656–2663, 2009
(Meth)acrylate‐based photoelastomers as tailored biomaterials for artificial vascular grafts
Authors: Baudis Stefan , Heller Christian , Liska Robert , Stampfl Juergen , Bergmeister Helga , Weigel Guenter
Published: April 2009

Cardiovascular disease is one of the leading causes of morbidity and mortality in the western hemisphere. Currently available synthetic vascular conduits, like Dacron or ePTFE show excellent long‐term results for large‐caliber arterial reconstruction (aorta, iliac vessels) but when used for small diameter (<4 mm) vessel reconstruction, patency rates are extremely poor. We therefore aim at developing suitable blood vessel substitutes out of biocompatible photopolymer formulations, which can be printed by rapid prototyping. Rapid prototyping offers the possibility to create cellular structures within the grafts that favor the ingrowth of tissue. To meet the high requirements for artificial biomaterials, it is necessary to develop new resin formulations. Beside the biocompatibility, the mechanical properties—a low elastic modulus (500 kPa) at a relatively high tensile strength (1.0 MPa) and a high strain at break (130%)—play a central role. Resin systems containing cyanoethyl acrylate have shown to be highly reactive, have good mechanical properties and sufficient in vitro biocompatibility. Elastic modulus and tensile strength which should be similar to natural blood vessels were adjusted by the ratio of acrylate‐based crosslinkers and—in case of hydrogels —the percentage of water. Finally, we were able to print small diameter conduits by microstereolithography. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2664–2676, 2009
Rheology and morphology change with temperature of SEBS/hydrocarbon oil blends
Authors: Sugimoto Masataka , Sakai Keisuke , Aoki Yuji , Taniguchi Takashi , Koyama Kiyohito , Ueda Toshihiro
Published: April 2009

The effect of hydrocarbon oil incorporation on the rheological and phase behaviors of poly(styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene) (SEBS) has been investigated. SEBS‐A1 (neat SEBS) shows a presence of very long relaxation time mode even at the highest temperature carried out here. On the other hand, G′ of SEBS‐A3 (oil concentration = 50 wt %) drastically decreases with increase of temperature at a critical temperature, which can be assigned to be order–disorder transition (ODT). The critical temperature was determined by two rheological criteria. Incorporation of hydrocarbon oil affects the ODT temperature. The rheological response is very sensitive to a few temperature increases around the ODT temperature. Above the critical temperature, G′ finally yields the terminal flow in the low frequency range. The morphological observation at various temperatures was determined using atomic force microscopy (AFM) equipped with environmental controller. This enabled in situ observation of structural change of SEBS induced by temperature and phase transition. We found that the layered texture, mostly aligned along the surface can be seen for SEBS‐A1 ranging from room temperature to 230 °C, though the image contrast reduced by an increase of temperature. SEBS‐A3 showed sphere domains at room temperature and also remains the structure at a critical temperature. The phase separated structure disappeared almost completely above ODT temperature, which was confirmed by the rheologial criteria. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 955–965, 2009
Eutectic crystallization and hydrogen bonding interactions in polymer/surfactant blends
Authors: Liu Jing , Hameed Nishar , Guo Qipeng
Published: April 2009

The unusual eutectic crystallization behavior in the poly(ε‐caprolactone) (PCL) and 3‐pentadecylphonel (PDP) binary blends was investigated by differential scanning calorimetry and Fourier transform infrared (FTIR) spectroscopy. A eutectic system was found with the eutectic composition at 60 wt % PDP and the eutectic melting temperature at 35 °C. The melting process of the blend at the eutectic composition was studied by in situ FTIR. The concurrence of the melting of PCL and PDP crystallites and the sequential formation of hydrogen bonding interaction between PDP molecules and PCL chains were traced. It was also found that a further increase in temperature above the eutectic melting temperature would impair the hydrogen bonding and increase the content of nonassociated phenol hydroxyl group. The semicrystalline morphology of blends affected by the composition was also investigated. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1015–1023, 2009
Orientation behavior of attapulgite nanoparticles in poly(acrylonitrile)/attapulgite solutions by rheological analysis
Authors: Yin Han , Mo Di , Chen Dajun
Published: April 2009

Nanocomposites based on poly(acrylonitrile) (PAN) and attapulgite (AT) had been prepared by solution blending in dimethyl sulfoxide (DMSO). The rheological properties of the nanocomposites solutions were investigated by HAAKE rheometer with plate‐cone geometry. The steady and oscillation shear experiments were carried out to investigate the effects of clay exfoliation and orientation as well as polymer‐clay interaction. The presence of small amount of AT nanoparticles with large aspect ratio improved the fluidity of these PAN solutions under low shear rate, whereas large amount of AT will reduce its aspect ratio by aggregation and constrain the polymer segment motion in the solutions. The relaxation and disentanglement behaviors of the PAN chains in nanocomposite solutions were also studied by oscillation and thixotropic experiments, from which, it can be concluded that well dispersed and oriented AT nanorods will reduce interaction among macromolecules. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 945–954, 2009
Equations of state for polyamide‐6 and its nanocomposites. II. Effects of clay
Authors: Utracki L. A.
Published: April 2009

The pressure‐volume‐temperature (PVT) dependencies of polyamide‐6 and its nanocomposites (polymeric nanocomposites) were measured at temperatures T = 300–600 K and pressures P = 0.1–190 MPa, thus spanning the range of molten and “solid” phases. The Simha‐Somcynsky (S‐S) cell‐hole equation of state (EOS) was used for describing the molten region. At Tg(P) ≤ T ≤ Tm(P), the “solid” phase is a mixture of the liquid polyamide‐6 with dispersion of crystals. Accordingly, the PVT behavior in this region was described as a combination of the S‐S EOS for the liquid phase and the Midha‐Nanda‐Simha‐Jain (MNSJ) EOS for the crystalline one. These two theories based on different models yielded two sets of the characteristic reducing parameters, P*, T*, V* and the segmental molecular weight, Ms. Incorporation of 2 and 5 wt % clay increased P* and reduced T* and V*, but the effects were small. Fitting the combination of S‐S and MNSJ EOS' to isobaric “solid” phase data yielded the total crystallinity, Xcryst, and the correcting excess specific volume, ΔVm,c. Both parameters were sensitive to pressure, P, and the clay content, w—the former increased with P and w, whereas the latter decreased. The raw PVT data were numerically differentiated to obtain the thermal expansion and compressibility coefficients, α and κ, respectively. At T < Tm, addition of clay reduced their relative magnitude, whereas at T > Tm, the opposite effect was observed, most likely owing to the excess of intercalant in the polymeric nanocomposites samples. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 966–980, 2009
Influence of chromophore concentration and network structure on the photo‐orientation properties of crosslinked epoxy‐based azopolymers
Authors: Fernández R. , Mondragon I. , Galante M. , Oyanguren P.
Published: April 2009

An azo prepolymer (TAZ) was synthesized by reaction between Disperse Orange‐3 (DO3) and diglycidyl ether of bisphenol A (DGEBA). Selected amounts of TAZ were blended with DGEBA and cured with an aliphatic diamine, either meta‐xilylenediamine (MXDA) or polyetheramines (Jeffamine D series). The photoinduced anisotropy and optical storage properties in two series of crosslinked epoxy‐based azo polymers with different architectures and chromophore contents (from 3 to 24 in weight) have been investigated. Measurements of the birefringence (Δn) induced with linearly polarized 488 nm light show that the Δn values increases with DO3 weight fraction. Networks with the same chromophore concentration but different backbones exhibit similar levels of induced anisotropy under the same irradiation conditions. The remaining birefringence and relaxation times are influenced by the molecular weight between crosslinks $ \overline {M_c} $ of networks. Higher $ \overline {M_c} $ is reflected in shorter relaxation times and lower remaining birefringence. In terms of the level of induced dichroism measured on relaxed films, it was found an agreement with the remaining anisotropy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1004–1014, 2009
Interest in a psycho‐educational group intervention among out‐patients with malignant melanoma in relation to their need: which patients are likely to participate?
Authors: Winzer Alexandra , Hoppe Annekatrin , Altenhoff Jürgen , Kuwert Christoph , Koch Uwe , Schulz Holger
Published: April 2009

The aim of this study was to examine the interest which patients with malignant melanoma may have in a six week psycho‐educational group intervention and determine factors that are associated with their degree of interest. Of 144 outpatients, 121 (84%) agreed to participate in the interview (78 women, 66 men, mean age 59, SD=15; mean time since surgery=57 months, SD=55). About one‐third (29%) of the sample had either nodal or in‐transit metastases. A semi‐structured interview was conducted to assess patients' interest (perceived need) in the intervention. We administered the Hornheide questionnaire and other psychosocial measures to identify highly distressed patients (expert‐defined need). Lower age, being male, having no partner and lower cognitive avoidance emerged as significant predictors for a general interest in the intervention (n=92). A substantial number of patients (42.5%) stated a willingness to participate in the intervention at that time. Two problematic subgroups could be identified in the sample: patients in an expert‐defined need of support who lacked any interest (‘avoiders’) and interested patients without an expert‐defined need (‘skilled help‐seekers’). In order to achieve consistent results when conducting future interventions, the interventions should either be limited to patients with expert‐defined need or patients should be carefully controlled for this variable. Copyright © 2009 John Wiley & Sons, Ltd.
Structural and Optical Investigations of Silicon Carbon Nitride Thin Films Deposited by Magnetron Sputtering
Authors: Tomasella Eric , Spinelle Laurent , Bousquet Angélique , Rebib Farida , Dubois Marc , Eypert Céline , Gaston Jean Paul , Cellier Joel , Sauvage Thierry
Published: April 2009

Silicon carbon nitride thin films are deposited by sputtering a silicon carbide target under mixed Ar–N2 atmosphere. The flow ratio (RF = [N2]/[N2] + [Ar]) of these two gazes is set between 0 and 1. The deposits were analyzed by Rutherford backscattering (RBS), infrared, Raman, and electron spin resonance (ESR) spectroscopies. Nitrogen content in thin film was found to be sensitive to the sputtering atmosphere until RF = 0.3 and reached a plateau between 0.3 and 1. From a structural point of view, the analysis revealed that the sp2 carbon character and the C≡N or CN bonds increased with the nitrogen percentage in the gas mixture. These effects induced an increase of the structural disorder and the amount of dangling bonds in the layer bulk. The optical properties in terms of optical gap (Eg) and Urbach parameter (Eu) were also determined. Eg was found to increase with nitrogen percentage in the sputtering mixture, whereas Eu exhibited an opposite behavior. We also show that the refractive index and the extinction coefficient determined by ellipsometric spectroscopy are sensitive to the structural modification.
New Antimicrobial Materials Based on Polymers With Nanostructured Surface Modified by Organic Fullerene[60] Derivatives
Authors: Ellinson Vera M. , Yurovskaya Marina A. , Lyamin Andrey N. , Ovchinnikova Natalia S. , Naumkin Alexander V.
Published: April 2009

In the present work, the surface of natural and artificial polymers was modified by plasma treatment using reactive gases mixture, ion‐beam‐induced deposition of α‐C:H films and organic C60 derivatives deposition. The study of prepared biomaterials with nanostructured surface was carried out by means of atomic force microscopy, X‐ray photoelectron spectroscopy, contact angle measurement and surface energy calculation. The investigation of antimicrobial activity of the materials was carried out by application method in relation to Gram‐positive (Staphylococcus aureus ATCC 29213) and Gram‐negative (Escherichia coli ATCC 54383 and Pseudomonas aeruginosa ATCC 27853) microorganisms and fungi (Candida albicans).
Density and Aging Behavior of Primary Amino Groups on Afterglow Plasma‐Treated Low‐Density Polyethylene (LDPE)
Authors: Lachmann Kristina , Michel Benedikt , Klages Claus‐Peter
Published: April 2009

Quantitative determination of primary amino group densities using chemical derivatization (CD) ATR FT‐IR spectroscopy was applied to study the amination rate in N2 + NH3 and Ar + NH3 dielectric barrier discharge afterglows. Compared to N2 + H2 mixtures and pure N2, the initial plasma‐amination rate is reduced, presumably due to a smaller concentration of reactive species that are consumed by reactions with NH3. The aging behavior of LDPE samples plasma treated in the afterglow of N2, N2 + H2, and N2 + NH3 discharges was also studied using CD XPS and CD ATR FT‐IR measurements over a period of 6 weeks after the treatment. Using gas mixtures of N2 + H2, the highest amount of primary amino groups was obtained. It has been ascertained that the primary amino groups are not stable during the storage under ambient conditions due to the oxidation of the surface and migration processes.
Increased serum interleukin‐5 and vascular endothelial growth factor in children with acute mycoplasma pneumonia and wheeze
Authors: Choi Ic Sun , Byeon Jung Hye , Yoo Young , Lee Kwang Chul , Choung Ji Tae
Published: April 2009

Acute mycoplasma pneumonia may be accompanied by wheeze in some children considered not to have asthma. The aim of the present study was to evaluate cytokine secretion in children with acute mycoplasma pneumonia and wheeze. We studied 58 patients with mycoplasma pneumonia (12 with wheeze, Group 1; 46 without wheeze, Group 2) and 36 patients of non‐mycoplasma pneumonia (Group 3). Serum levels of interleukin (IL)‐4, IL‐5, interferon (IFN)‐γ, and vascular endothelial growth factor (VEGF) were measured using an enzyme‐linked immunosorbent assay kits. The mean ± SD IL‐5 level of Group 1 was 97.1 ± 73.0 pg/ml, which was significantly higher than that of Group 2 (28.2 ± 32.2 pg/ml) and that of Group 3 (35.7 ± 42.0 pg/ml). The mean ± SD VEGF level of Group 1 was 687.5 ± 385.8 pg/ml, which was significantly higher than that of Group 2 (310.0 ± 251.9 pg/ml) and that of Group 3 (402.3 ± 279.5 pg/ml). No significant differences in serum levels of IL‐4, IFN‐γ, and IgE were observed between the groups. Our results show that children with mycoplasma pneumonia and wheeze have significantly higher serum levels of IL‐5 and VEGF. These increased immune responses may be associated with the pathophysiological mechanisms by which the Mycoplasma pneumoniae contribute to the development of wheeze during acute mycoplasma pneumonia. Pediatr Pulmonol. 2009; 44:423–428. © 2009 Wiley‐Liss, Inc.
Lower respiratory infections by adenovirus in children. Clinical features and risk factors for bronchiolitis obliterans and mortality
Authors: Murtagh Patricia , Giubergia Verónica , Viale Diana , Bauer Gabriela , Pena Hebe Gonzalez
Published: April 2009

Adenovirus (Ad) respiratory infections have a profound impact in Argentina. Severe chronic disease and a high mortality rate are observed in children after acute lower respiratory infections (ALRI) by Ad.

Methods

A retrospective observational study was performed to describe clinical characteristics and to analyze risk factors for bronchiolitis obliterans (BO) and death in 415 children hospitalized with ALRI caused by Ad from March 1988 to May 2005.

Results

Mean age of patients was 10.7 months (±9.2) Overall 80% of patients were healthy before ALRI. Forty‐nine percent recovered, sequelae were observed in 36% and 15% died. Independent risk factors for BO were: >30 days of hospitalization (odds ratio (OR) 27.2, 95% confidence interval (CI) 14.6–50.9), multifocal pneumonia (OR 26.6, 95% CI 5.3–132) and hypercapnia (OR 5.6, 95% CI 3.5–9). Independent risk factors for death in acute stage of disease were: mechanical assistance (OR 121, 95% CI 18.2–814), multifocal pneumonia (OR 102, 95% CI 9.5–31.1), hypercapnia (OR 42.6, 95% CI 10.2–177.1), coagulation disorders (OR 17, 95% CI 8.25–35), neurological symptoms (OR 12.7, 95% CI 3.5–6.6) and co‐infection with measles (OR 9.6, 95% CI 2.1–44.2).

Conclusions

High incidence of sequelae and mortality in previously healthy children after Ad infection was observed in a population of children from Argentina. Pediatr Pulmonol. 2009; 44:450–456. © 2009 Wiley‐Liss, Inc.
Changes in lung function in young cystic fibrosis patients between two courses of intravenous antibiotics against Pseudomonas aeruginosa
Authors: Béghin Laurent , Michaud Laurent , Loeuille Guy‐André , Wizla‐Derambure Nathalie , Sayah Hocine , Sardet Anne , Thumerelle Caroline , Deschildre Antoine , Turck Dominique , Gottrand Frédéric
Published: April 2009

Background and Aims

Repeated intravenous antibiotic therapy (IVAT) against chronic pulmonary infection with Pseudomonas aeruginosa is often necessary in cystic fibrosis patients (CF). The aim of this study was to monitor kinetics of degradation of pulmonary and nutritional status after IVAT in CF patients.

Methods

Lung function, nutritional status and physical activity (PA) were measured for 21 CF patients (mean ± SD age, 16 ± 1.9 years; 9 boys) who were chronically colonized by P. aeruginosa. Each parameter was measured every 15 days during 3–6 months.

Results

Nutritional status as well as PA did not change in the interval of 2 IVAT. In contrary, lung function worsened with a decrease of −14.6% of the FEV1 (P < 0.05).

Conclusion

In CF, there is a progressive decrease in lung function without any evident deterioration of nutritional status and PA between two IVAT. Pediatr Pulmonol. 2009; 44:464–471. © 2009 Wiley‐Liss, Inc.
Extreme BMI predicts higher asthma prevalence and is associated with lung function impairment in school‐aged children
Authors: Chu Yu‐Te , Chen Wu‐Yuan , Wang Tsu‐Nai , Tseng Hsing‐I , Wu Jiunn‐Ren , Ko Ying‐Chin
Published: April 2009

Background

The prevalence of obesity and asthma has increased in recent decades. We investigated the relationship between body mass index (BMI) and lung function, and also tried to determine if asthma prevalence differs between obese and non‐obese children.

Methods

An International Study of Asthma and Allergies in Childhood (ISAAC) video questionnaire survey that included 170,457 students in junior high school was conducted during a 1‐year period. Using random selection, 15,761 students were selected for lung function testing; 14,654 (93.0%) completed the lung function tests. Multiple logistic regression analysis was used to analyze the risk factor of asthma, such as atopic diathesis, BMI, exercise habits, smoking and secondary smoking. The detailed comparison in lung functions was plotted by asthmatic versus non‐asthmatic, and between both sexes.

Results

The risk factor of ISAAC‐identified asthma were male sex, atopy, elevated BMI, higher education levels of the parents (higher than senior high school), family smoking ≥1 pack/day, self‐reported smoking. The prevalence of asthma increased as BMI elevated in both sex. The FEV1/FVC declined as BMI elevated in both sex. The thin and underweight male students had declined FEF 25–75% and PEF.

Conclusions

Extreme BMI is associated with different lung function impairment. This study showed that high BMI in both sexes was associated with low FEV1/FVC and low BMI in males are associated with poor PEF and FEF 25–75% and contributed to the symptoms of asthma. Pediatr Pulmonol. 2009; 44:472–479. © 2009 Wiley‐Liss, Inc.
Oropharyngeal flora in healthy infants: Observations and implications for cystic fibrosis care
Authors: Carlson David , McKeen Elizabeth , Mitchell Michael , Torres Brenda , Parad Richard , Comeau Anne Marie , O'Sullivan Brian P.
Published: April 2009

Objective

The purpose of this preliminary study was to determine normal oropharyngeal flora in healthy, non‐CF infants in order to help care givers better interpret culture results obtained from infants with CF.

Methods

Oropharyngeal cultures were obtained from 104 healthy infants <12 months old. Cultures were obtained using the same methods as for CF patients and were inoculated onto routine CF culture media. Approximately 20 infants from each of 5 age groups (0–2 days, 3 days to <3 months, 3 months to <6 months, 6 months to <9 months or 9 months to <1 year) were included in the well child sample. In addition, we reviewed serial results of upper airway cultures obtained during the first year of life from 20 CF‐affected infants whose diagnosis was suggested by newborn screening.

Results

Well infants in the first 48 hr of life had very few pathogenic organisms found in their oropharyngeal cultures; 1/21 had S. aureus. Of the 83 samples from infants over 48 hr of age, we found that 27% (23/83) had S. aureus in their oropharyngeal cultures. Many infants had polymicrobial cultures. Eleven percent of culture samples had E. coli, E. cloacae, H. influenzae, or M. catarrhalis. Three of 83 cultures were positive for non‐mucoid Ps. aeruginosa (3.6%), while 2 others were positive for Ps. putida.

Conclusion

Healthy infants can have multiple gram‐negative and gram‐positive organisms recovered from their oropharynx. S. aureus and enteric gram‐negative organisms, including non‐mucoid Ps. aeruginosa, can be found in the oropharynx of well children up to 1 year of age. Care should be taken to not over interpret the presence of some of these organisms in the oropharyngeal cultures of asymptomatic CF infants. Pediatr Pulmonol. 2009; 44:497–502. © 2009 Wiley‐Liss, Inc.
Residual efficacy of pyriproxyfen and hydroprene applied to wood, metal and concrete for control of stored‐product insects
Authors: Arthur Frank H , Liu Siwei , Zhao Baige , Phillips Thomas W
Published: April 2009

BACKGROUND: Pyriproxyfen and hydroprene are insect growth regulators (IGRs) that have been evaluated to control insect pests of field crops, but there are limited reports of efficacy against stored‐product insects. A laboratory study was conducted to determine residual efficacy of pyriproxyfen and hydroprene on wood, metal and concrete surfaces. Pyriproxyfen was applied to the surfaces at 1.15 and 2.3 mg active ingredient [AI] m−2, while hydroprene was applied at the label rate of 19 mg AI m−2. Late‐instar larvae of Tribolium confusum Jacqueline DuVal, T. castaneum (Herbst), Oryzaephilus surinamenis L., Lasioderma serricorne (F.) and Plodia interpunctella (Hübner) were exposed with a food source on the treated surfaces. Residual testing was conducted at 1, 28 and 56 days post‐treatment.

RESULTS: Hydroprene was least persistent on concrete and generally most persistent on metal. Pyriproxyfen gave greater residual persistence than hydroprene, and there was no consistent difference in efficacy among the three surfaces. Efficacy varied among the five insect species, but generally P. interpunctella was the most tolerant species to both IGRs.

CONCLUSIONS: Pyriproxyfen gave effective residual control of primary stored‐product insect species by inhibiting adult emergence of exposed larvae. Results show that pyriproxyfen can be a useful addition for pest management programs in mills, warehouses and food storage facilities. Published 2009 by John Wiley & Sons, Ltd.