bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of TiO2 and polymer nanocomposite films with high refractive index
Authors: Nakayama Norio , Hayashi Toyoharu 
Published: June 2007

AbstractNovel nanocomposite films of TiO2 nanoparticles and hydrophobic polymers having polar groups, poly (bisphenol‐A and epichlorohydrin) or copolymer of styrene and maleic anhydride, with high refractive indices, high transparency, no color, solvent‐resistance, good thermal stability, and mechanical properties were prepared by incorporating surface‐modified TiO2 nanoparticles into polymer matrices. In the process of preparing colloidal solution of TiO2 nanoparticles, severe aggregation of particles can be reduced by surface modification using carboxylic acids and long‐chain alkyl amines. These TiO2 nanoparticles dispersed in solvents were found not to aggregate after mixing with polymer solutions. Transparent colorless free‐standing films were obtained by drying a mixture of TiO2 nanoparticles colloidal solution and polymer solutions in vacuum. Transmission electronic microscopic studies of the films suggest that the TiO2 nanoparticles of 3–6 nm in diameter were dispersed in polymer matrices while maintaining their original size. Thermogravimetric analysis results indicate that the nanocomposite film has good thermal stability and the weight fraction of observed TiO2 nanoparticles in the film is in good accordance with that of theoretical calculations. The refractive index of nanocomposite films of TiO2 and poly(bisphenol‐A and epichlorohydrin) was in the range of 1.58–1.81 at 589 nm, which linearly increased with the content of TiO2 nanoparticles from 0 to 80 wt %. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effect of blending high‐pressure low‐density polyethylene on the crystallization kinetics of linear low‐density polyethylene
Authors: Kathy Liu Jiameng , Nozue Yoshinobu , Nagamatsu Tatsuhiro , Hosoda Satoru 
Published: June 2007

AbstractIt is well known that the addition of a small amount of high‐pressure low‐density polyethylene (HP‐LDPE) to linear low‐density polyethylene (LLDPE) can improve the optical properties of LLDPE, and LLDPE/HP‐LDPE blend is widely applied to various uses in the field of film. The optical haziness of polyethylene blown films, as a result of surface irregularities, is thought to be as a consequence of the different crystallization mechanisms. However, not much effort has been directed toward understanding the effect of HP‐LDPE blending on the overall crystallization kinetics (k) of LLDPE including nucleation rate (n) and crystal lateral growth rate (v). In this study, we investigated the effect of blending 20% HP‐LDPE on the crystallization kinetics of LLDPE polymerized by Ziegler‐Natta catalyst with comonomer of 1‐butene. Furthermore, by combining depolarized light intensity measurement (DLIM) and small‐angle laser light scattering (SALLS), we have established a methodology to estimate the lateral growth rate at lower crystallization temperatures, in which direct measurement of lateral growth by polarized optical microscopy (POM) is impossible due to the formation of extremely small spherulites. This investigation revealed that HP‐LDPE blending leads to enhanced nucleation rate, reduced crystal lateral growth rate, and a slight increase in the overall crystallization kinetics of pure LLDPE. From the estimated crystal lateral growth rate, it was found that the suppression in v from HP‐LDPE blending is larger at lower temperatures than at higher temperatures. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Degradation behavior of polyoxymethylene: Influence of different stabilizer packages
Authors: Archodoulaki V.‐M. , Lüftl S. , Seidler S. 
Published: June 2007

AbstractStabilizer effects of two types (homopolymer and copolymer) of commercially available polyoxymethylenes containing two different stabilizer packages under various aging conditions have been studied by the application of thermogravimetric analysis coupled with mass spectrometry. Increasing yellowness during thermooxidative aging has been observed. Investigations of the melt volume rate have proved that the UV‐stabilized materials exhibit a higher increase in the melt volume rate after oven aging, which is caused by reactions of the additives, than the solely heat‐stabilized materials. The thermogravimetric analysis/mass spectrometry investigations have proved broad synergy effects between the heat‐ and UV‐stabilizer systems. The formation of chains with thermally stable end groups or of cyclic products proceeds during aging, particularly in the presence of UV stabilizers. This formation might be the result of intermolecular transacetalization reactions. The degradation behavior of UV‐irradiated homopolymer and copolymer samples has also been investigated. Oven storage and weathering cause comparable shifts in the derivative thermogravimetry traces, so similar damage reactions can be suggested. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis and properties of hydrogen‐bonded poly(amide‐imide) hybrid films
Authors: Tsai Mei‐Hui , Huang Shih‐Liang , Lin J. C. Muti , Ko Cheng‐Jung , Chen Ying‐Ling , Lu Chun‐Mei , Chen Chiou‐Juy , Yen Chia‐Hui 
Published: June 2007

AbstractPoly(amide‐imide), PI, hybrid films are prepared by using sol–gel techniques. First, the poly(amide amic acid) with controlled block chain length of 5000 and 10,000 g/mol and uncontrolled chain length are synthesized by condensation reaction with 4,4′‐diaminodiphenyl ether (ODA), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA), trimellitic anhydride chloride (TMAC) and terminated with p‐aminopropyltrimethoxysilane (APrTMOS). And then the imidization reactions of poly (amide amic acid) are proceeded to obtain the poly (amide‐imide) hybrid film. Hybrid films with 5000 g/mol block chain length possess higher storage modulus, lower glass transition temperature and damping intensity comparing to films with 10,000 g/mol block chain length. The addition of TMAC to the poly(amide‐imide) hybrids is due to the increase of toughness and intermolecular hydrogen bonding, which is the average strength of intermolecular bonding and studied by the hydrogen‐bonded fraction (fbonded), frequency difference (Δν) and shiftment. Meanwhile, PI hybrid films containing more APrTMOS and TMAC content possess higher thermal and mechanical properties. On the other hand, hybrid films with 10,000 g/mol block chain length and more TMAC content have higher gas permeabilities than other films. The degradation temperatures of 5 wt % loss of all hybrid films are all higher than 540°C and increased as the increase of TMAC content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Synthesis and Antibacterial Activity of tert‐Butyl [1‐benzyl‐2[(4‐aryl‐2‐thiazolyl)hydrazono]ethyl]carbamate Derivatives
Authors: Turan‐Zitouni Gülhan , Fehrentz Jean‐Alain , Chevallet Pierre , Martinez Jean , Kaplancıklı Zafer Asim , Özdemir Ahmet , Arslanyolu Muhittin , Yıldız Mehmet Taha 
Published: June 2007

AbstractThe increasing clinical importance of drug‐resistant fungal and bacterial pathogens has lent additional urgency to microbiological research and new antibacterial compound development. For this purpose, new tert‐butyl[1‐benzyl‐2[(4‐aryl‐2‐thiazolyl)hydrazono]ethyl]carbamate derivatives were synthesized and evaluated for antibacterial activity. The reaction of Boc‐L‐phenylalaninal with thiosemicarbazide gave the thiosemicarbazone which furnished the title compounds by reaction with phenacyl bromides. The newly synthesized compounds were screened for antibacterial activity and toxicity. While microdilution broth susceptibility assay was used for the antibacterial activity evaluation of the compounds against the strains E. coli (NRRL B‐3704), M. luteus (NRRL B‐4375), B. cereus (NRRL B‐3711), P. aeruginosa (NRRL B‐23), and S. fecalis (NRRL B‐14617), the Artemia salina 96‐well assay was used to determine cytotoxicities of the compounds. Observations obtained from the bioassays showed that some of the compounds are highly active against E. coli, M. luteus, and B. cereus when compared with the control agent and showed low toxicity.
Synthesis and Antidepressant‐Like Profile of Novel 1‐Aryl‐3‐[(4‐benzyl)piperidine‐1‐yl]propane Derivatives
Authors: Köksal Meriç , Bilge S. Sırrı 
Published: June 2007

AbstractThis study describes the chemical synthesis and pharmacological evaluation of some new 1‐aryl‐3‐[(4‐benzyl)piperidine‐1‐yl]propane derivatives as antidepressants. The structures attributed to the compounds were elucidated using IR and 1H‐NMR spectroscopic techniques besides elemental analysis. The antidepressant‐like effect of these compounds was assessed by using the forced swimming test (FST), a validated experimental model of depression in mice. A clear antidepressant‐like effect was shown for compounds 1, 2 and 4 by a significant decrease in immobility behaviour.
Guardianship determinations by judges, attorneys, and guardians
Authors: Gavisk Melanie , Greene Edith 
Published: June 2007

AbstractGuardianship is intended to protect incapacitated individuals through the appointment of a surrogate decision maker. Little is known about how judges, attorneys, and professional guardians assess the need for guardianship, to what extent they apply statutory guidelines when making these determinations, and how their decisions compare. Three groups of participants (probate judges, elder law attorneys, and professional guardians) read vignettes portraying older adults that varied in the extent to which the evidence supported the appointment of a guardian. They were asked about the appropriateness of various resolutions. Participants were reluctant to endorse full guardianship even when warranted by the evidence and preferred informal, family‐based interventions that do not involve legal action. Professional groups did not always agree on the appropriate resolutions, suggesting that one's professional orientation may play a role in perceptions of older adults. Copyright © 2007 John Wiley & Sons, Ltd.
Reactions of Ytterbocenes with Diimines: Steric Manipulation of Reductive Reactivity
Authors: Trifonov Alexander A. 
Published: June 2007

AbstractThis review is devoted to the investigation of reactions of ytterbocenes with diimines. These reactions are found to be strongly influenced by the steric crowding in the coordination sphere of the metal atom and the coordination capacities of π‐aromatic ligands coordinated to the ytterbium. The reactions may occur with oxidation of the ytterbium atom as well as with retention of its oxidation state. C–C bond formation, C–H bond activation, C=N bond insertion, and oxidative Yb–C bond cleavage processes are documented for reactions of ytterbocenes with diimines. Steric overcrowding of the coordination sphere of the ytterbium atom can induce “extra” reducing ability of ytterbocenes and allow them to act not only as one‐ but also as two‐electron reductants with respect to diimines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Effects of moisture content, impulse polarity and earth electrode's dimension on dry and wet sand under high voltage conditions
Authors: Nor N. Mohamad , Ramli A. 
Published: June 2007

AbstractThe study on the physics of discharges in soil and performance of earthing networks subjected to lightning currents are important in order to improve the reliability of electrical systems and to obtain better electrical models of earthing systems. The soil characteristics of various moisture contents under high‐impulse currents have been well studied in previous studies. In this present study, fast impulse generator is used to investigate the dry soil characteristics in two cylindrical test cells of different outer radii; 15 and 20 cm under high magnitude fast impulse conditions of both impulse polarities. This allows to study the characteristics of dry soil under high‐impulse current conditions, and allows a comparison between the dry and wet soil characteristics under high‐impulse conditions such as before and after breakdown of the test cell. In this study, the effects of impulse polarities, moisture content in soil and the outer dimensions of test cell on the soil characteristics under high‐impulse currents were investigated. Copyright © 2007 John Wiley & Sons, Ltd.
Statistical characterization of impact of system variables on temporal dynamics of groundwater in highly weathered regoliths
Authors: Rasiah V. , Armour J. D. , Cogle A. L. 
Published: June 2007

AbstractIn situations where the water table fluctuates during the rainy season the characterization of the impact of system variables on the temporal dynamics of the groundwater (GW) is essential to improve the understanding at catchment or regional scale behaviour of GW. In this study the appropriateness of the statistical parameters; mean, median, the 80th percentile (PC80), coefficient of variation (CV), correlation coefficient (r), and multiple regression models were assessed to characterize the impact of system variables on the temporal dynamics of hydraulic head relative to ground surface (HH) during rainy seasons. The study was conducted from 1999 to 2003 in the wet tropical Johnstone River catchment (JRC) in north‐east Queensland, Australia. Piezometer wells were installed at 32 sites under cropping to 5–90 m depth on different soil types, landscape positions, and varying proximity to surface water bodies (i.e. four system variables). The HH was measured, at least at 10–15 day intervals during 1–5 consecutive rainy seasons. The HH in the 32 wells fluctuated throughout each of the five rainy seasons. The mean HH averaged over the seasons ranged from 1·1 to 17·2 m across the wells, the median from 0·9 to 17·3 m, and the PC80 from 0·3 to 16·1 m. The temporal behaviour of HH characterization by mean of means of HH, the mean of medians of HH, and the mean of PC80 of HH, indicated the HH can be classified to belong to three different groups for each one of these parameters. The impact of the system variables on temporal dynamics, explored using multiple regression procedure, indicated that the model for median was marginally better than mean. The CV was found to be most appropriate parameter to characterize the impact of GW system variable (aquifer type), a component of the system variables, on temporal dynamics. The interactions of GW (i) belonging to different GW system and (ii) at shoulder with footslope in a landscape were best characterized by simple linear correlations. Copyright © 2007 John Wiley & Sons, Ltd.
Stochastic simulation of droughts. Part 2: regional droughts
Authors: Mohan S. , Sahoo P. K. 
Published: June 2007

AbstractIn Part 1 we demonstrated the applicability of stochastic models to predicting the characteristics of point drought events within any planning period by means of a case study (Mohan S, Sahoo PK (2007) Hydrological Processes 21: this issue). In addition, studies on regional droughts are important in the context of regional level planning and evolving management strategies. The small number of drought events from a particular streamflow or rainfall series, when subjected to statistical analysis in order to predict future occurrences, produces results that are not very reliable. To overcome this difficulty, we propose using a long sequence of synthetically generated annual rainfall series at various rain‐gauge stations of a region, and multiyear regional droughts were derived from both historic and generated series. The key parameters for a successful regional multiyear drought study are the critical area ratio and the critical level, and the area affected by the drought can be ascertained using these parameters. The important regional drought parameters were determined and their suitable probability distributions were arrived at by studying a total of nine possible probability models; these models can be used in predicting the longest regional drought duration and the greatest regional drought severity with a given return period. The effect of change of critical parameters on the regional drought parameters is also studied and reported. Copyright © 2007 John Wiley & Sons, Ltd.
Stochastic simulation of droughts. Part 1: point droughts
Authors: Mohan S. , Sahoo P. K. 
Published: June 2007

AbstractThe number of drought events derived from the historic streamflow or rainfall series will be limited and produce results that are not very reliable. This study proposes a drought simulation methodology that uses a long sequence of synthetically generated monthly streamflow/rainfall series, from which it is possible to drive a large sample of drought events and the prediction of drought characteristics will be reliable. The modified Herbst method has been used to identify droughts in the generated streamflow and rainfall series. The drought simulation procedure is illustrated with a case study of the Bhadra reservoir catchment in Karnataka State, India. Monthly droughts were derived from both historic and generated monthly streamflow and rainfall series. The important drought characteristics were determined and the suitable probability distribution for each parameter was arrived at after studying seven different probability models. The use of the probability curves thus derived has been illustrated with examples (referred to in Part 1 as ‘point droughts’). Similarly, the development and application of stochastic models for the prediction of regional drought parameters have been illustrated with examples in the accompanying paper (Part 2: regional droughts). Copyright © 2007 John Wiley & Sons, Ltd.
Expression of osteopontin, a target gene of de‐regulated Wnt signaling, predicts survival in colon cancer
Authors: Rohde Franziska , Rimkus Caroline , Friederichs Jan , Rosenberg Robert , Marthen Carmen , Doll Dietrich , Holzmann Bernhard , Siewert Jörg‐Rüdiger , Janssen Klaus‐Peter 
Published: June 2007

AbstractOsteopontin (OPN) is a secreted phosphoprotein, which has been reported to be associated with tumor progression in numerous solid tumors. In a previous transcriptome study on colorectal cancer, we identified the gene OPN among the most strongly up‐regulated transcripts. OPN has been suggested as a putative target of Wnt signaling, but the molecular mechanism responsible for its aberrant transcription is not fully understood. We analyzed 13 normal colon tissues, 9 adenomas, 120 primary colon tumors, and 10 liver metastases by quantitative reverse‐transcription PCR. OPN expression was strongly elevated in primary colon cancer and liver metastasis, but not in pre‐cancerous lesions and UICC stage I tumors. Multivariate analysis established OPN expression as an independent prognostic parameter for overall survival. Moreover, high OPN expression identified a subgroup of patients with bad prognosis. Next, we determined immunohistochemically a correlation of OPN expression with aberrant β‐catenin staining, which is indicative of Wnt activation. Elevated expression of OPN was significantly correlated with increased cytoplasmic and nuclear β‐catenin staining. The in vivo role of Wnt signaling for the expression of OPN was tested in genetically defined mouse models with (Apc1638N) or without (pvillin‐KRASV12G) Wnt activating mutations. Mutation of the tumor suppressor APC was necessary for upregulation of OPN expression in the murine tumors on transcript and on protein levels. Thus, OPN is a transcriptional target of aberrant Wnt signaling, and OPN expression alone predicts survival in human colon cancer. © 2007 Wiley‐Liss, Inc.
Paradoxical enhancement of CD8 T cell‐dependent anti‐tumor protection despite reduced CD8 T cell responses with addition of a TLR9 agonist to a tumor vaccine
Authors: Karan Dev , Krieg Arthur M. , Lubaroff David M. 
Published: June 2007

AbstractGeneration of antigen‐specific CD8+ T cell responses is considered optimal for an effective immunotherapy against cancer. In this study, we provide a proof of principle that in vitro observed diminished CD8+ T cell response provided a strong in vivo tumor protection. Immunization with an adenovirus vaccine containing ovalbumin (OVA) gene (Ad5‐OVA) strongly induces antigen‐specific CD8+ T cell responses measured in vitro using various immunological assays. However, in an attempt to augment the antigenic CD8+ T cell response, coinjection of a TLR9 agonist CpG ODN with the viral vaccine unexpectedly reduced the CD8+ T cell responses measured in vitro but provided a remarkably enhanced tumor protection compared to the CD8+ T cell response generated by Ad5‐OVA vaccine alone. Interestingly, despite reduced ex vivo/in vitro CD8+ T cell responses following Ad5‐OVA+CpG immunization, immunodepletion studies revealed that the augmented anti‐tumor immunity was primarily dependent on CD8+ T cells. The magnitude and effector function of anti‐OVA CD8+ T cells remain low following primary and secondary antigenic challenge, presenting a dichotomy between in vitro CD8 T cell responses and in vivo anti‐tumor immunity. To examine the impact of CpG ODN, we observed that presence of CpG suppresses the CD8+ T cell proliferation both in vitro and in vivo. These data demonstrate that coadministration of adenovirus vaccine with a TLR9 agonist can generate potentially effective tumor‐reactive CD8+ T cells in vivo. In addition, the results indicate that widely used standard immune parameters may not predict the vaccine efficacy containing a TLR9 agonist as adjuvant. © 2007 Wiley‐Liss, Inc.
Villous adenoma of extrahepatic bile duct: Contrast‐enhanced sonography findings
Authors: Xu Hui‐Xiong , Chen Li‐Da 
Published: June 2007

AbstractWe report a case of villous adenoma in the extrahepatic bile duct that was successfully diagnosed with contrast‐enhanced sonography (CEUS) before surgical resection. On baseline sonography, the mass appeared as a homogeneously isoechoic mass filling the bile duct from the confluence of the right and left hepatic ducts to the distal common bile duct. No intralesional flow signal was found on color Doppler imaging and power Doppler imaging. On CEUS, the mass showed homogeneous enhancement during arterial phase, thus confirming the neoplastic nature of the lesion. The enhancement decreased gradually so that the mass became hypoenhanced during portal and late phases. Surgical resection was performed, and pathologic examination confirmed a villous adenoma of the bile duct epithelium with mild dysplasia. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Tree‐ring reconstructions of precipitation and streamflow for north‐western Turkey
Authors: Akkemik Ünal , D'Arrigo Rosanne , Cherubini Paolo , Köse Nesibe , Jacoby Gordon C. 
Published: June 2007

AbstractWe describe tree‐ring reconstructions of spring (May‐June) precipitation and spring‐summer (May‐August) streamflow for north‐western Turkey, both beginning in AD 1650. These are among the first such reconstructions for the region, and the streamflow reconstruction is among the first of its kind for Turkey and the entire Middle East. The reconstructions, which both emphasize high‐frequency variations, account for 34 and 53% of their respective instrumental variance. Comparison to precipitation and runoff data provides some means of verification for the instrumental streamflow record, which is very short (30 years). Drought and flood events in the reconstructions are compared to historical archives and other tree‐ring reconstructions for Turkey. The results reveal common climatic extremes over much of the country. Many of these events have had profound impacts on the peoples of Turkey over the past several centuries. Copyright © 2007 Royal Meteorological Society