bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of temperature on the number of active sites and propagation rate constant at ethylene polymerization over supported bis(imino)pyridine iron catalysts
Authors: Barabanov Artem A. , Bukatov Gennady D. , Zakharov Vladimir A. 
Published: August 2008

AbstractThe inhibition of ethylene polymerization with radioactive carbon monoxide (14CO) was used to obtain data on the number of active sites (CP) and propagation rate constant (kP) at ethylene polymerization in the temperature range of 35–70 °C over supported catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 (L: 2,6‐(2,6‐(Me)2C6H3N = CMe)2C5H3N) with activator Al(i‐Bu)3. The values of effective activation energy (Eeff), activation energy of propagation reaction (EP), and temperature coefficients of variation of the number of active sites (ECp = Eeff − EP) were determined. The activation energies of propagation reaction for catalysts LFeCl2/Al2O3, LFeCl2/SiO2, and LFeCl2/MgCl2 were found to be quite similar (5.2–5.7 kcal/mol). The number of active sites diminished considerably as the polymerization temperature decreased, the ECp value being 5.2–6.2 kcal/mol for these catalysts at polymerization in the presence of hydrogen. The reactions of reversible transformations of active centers to the surface hydride species at polymerization in the presence and absence of hydrogen are proposed as the derivation of ECp. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6621–6629, 2008
Introduction of pH‐sensitivity into mechanically strong nanoclay composite hydrogels based on N‐isopropylacrylamide
Authors: Mujumdar Siddharthya K. , Siegel Ronald A. 
Published: August 2008

AbstractpH‐sensitive nanoclay composite hydrogels based on N‐isopropylacrylamide (NIPA) were synthesized by copolymerization with cationic and anionic comonomers. Laponite nanoclay particles served as multifunctional crosslinkers, producing hydrogels with exceptionally high mechanical strengths, as measured by elongation at break. Cationic copolymer gels based on NIPA and dimethylaminoethylmethacrylate were prepared by aqueous free radical polymerization, adopting a procedure reported by Haraguchi (Adv Mater 2002, 14, 1120–1124). Without modification, this technique failed to produce anionic copolymer gels of NIPA and methacrylic acid (MAA), due to flocculation of clay particles. Three methods were conceived to incorporate acidic MAA into nanoclay hydrogels. First, NIPA was copolymerized with sodium methacrylate under dilute conditions, producing hydrogels with good pH‐sensitivity but weak mechanical characteristics. Second, NIPA was copolymerized with methyl methacrylate, which was then hydrolyzed to generate acid sidegroups, yielding hydrogels that were much stronger but less pH sensitive. Third, NIPA was copolymerized with MAA following modification of the nanoclay surface with pyrophosphate ions. The resulting hydrogels exhibited both strong pH‐sensitivities at 37 °C and excellent tensile properties. Optical transparency changed during polymerization, depending on hydrophobicity of the components. This work increases the diversity and functionality of nanoclay hydrogels, which display certain mechanical advantages over conventionally crosslinked hydrogels. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6630–6640, 2008
Preferential selection of Cys‐constrained peptides from a random phage‐displayed library by anti‐glucitollysine antibodies
Authors: Rojas Gertrudis , Pupo Amaury , Aleman Maria Del Rosario , Vispo Nelson Santiago 
Published: August 2008

AbstractPhage‐displayed peptides recognized by two monoclonal antibodies against glucitollysine were selected. The most prominent feature of the peptide panel was the presence of paired Cys in most of them (21/24 peptides). The availability of a wide variety of peptides having differently spaced paired Cys, as well as truly linear Cys‐free peptides, gave the opportunity to explore the role of disulfide bridges in phage selection. Some Cys‐containing peptides came from a Cys‐flanked cyclic 9‐mer library, but most of them (18/21) were derived from a totally random 12‐mer library, and hence the presence of Cys was dictated by the selector antibodies. Motifs shared by several peptides (potentially involved in binding) often contained or were flanked by Cys residues. Binding of all Cys‐containing phage‐displayed peptides was abolished/decreased after a reducing treatment. Screening a random peptide library (without invariant Cys residues) is powerful enough to clearly reveal the need, preferences, and diversity of Cys‐mediated structural constraints for recognition. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Identification of novel peptide agonists from a random peptide library for a 5‐oxo‐ETE receptor, a receptor for bioactive lipids
Authors: Sasaki Yoshinori , Tsujii Takashi , Takeda Shigeki , Obinata Hideru , Izumi Takashi , Yamada Keiichi , Katakai Ryoichi 
Published: August 2008

AbstractA combinatorial peptide library contains an enormous combination of amino acid sequences and drug candidates, but an effective screening strategy to identify a variety of bioactive peptides has yet to be established. In this article, a random hexapeptide library was screened to identify novel peptide ligands for a 5‐oxo‐ETE receptor (OXER), which is a G‐protein‐coupled receptor for bioactive lipids, by using an OXER‐Gi1α fusion protein. We successfully identified 2 hexapeptides—Ac‐HMQLYF‐NH2and Ac‐HMWLYF‐NH2—that exhibited agonistic activity. Although the corresponding affinities were relatively low (EC50values of 146 and 6.7 µM, respectively), the activities were confirmed by other independent cell‐based assay methods, namely, intracellular calcium mobilization and cell chemotaxis. This study demonstrates that a combinatorial peptide library may be screened using a [35S]GTPγS binding assay with G‐protein‐coupled receptor (GPCR)–Gα fusion proteins, in general, and that of peptide ligands can be obtained even for nonpeptide receptors. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
A one‐year survey on the use of a powder from Rosa canina lito in acute exacerbations of chronic pain
Authors: Chrubasik C. , Wiesner L. , Black A. , Müller‐Ladner U. , Chrubasik S. 
Published: August 2008

AbstractThis pilot surveillance included 152 patients with acute exacerbations of chronic pain, 124 (Back group) with non‐specific low back pain (NSLBP), 20 with NSLBP overridden by osteoarthritic pain (Knee‐Hip group), and eight with specific LBP (included in the safety analysis). Patients were recommended the rose hip and seed powder LitozinR at a dose providing up to 3 mg of galactolipid/day for up to 54 weeks. Clinical symptoms and well‐being were assessed every 6 weeks. The patients also kept a diary of their pain and the requirement for rescue medication. Data were analysed by intention to treat with last observation carried forward.Only 77 patients completed the year of surveillance. Multivariate analysis suggested an appreciable overall improvement during the surveillance, irrespective of group, and this was reflected for most of the individual measures in repeated measures ANOVA. The degree and time‐course of improvement echoed that seen in similar surveillances of patients receiving an aqueous extract of Harpagophytum. Multiple regression analyses indicated that percentage changes from baseline tended to be greater in patients with greater degrees of pain and disability, but were otherwise largely unrelated to the patients' characteristics. There were no serious adverse events.The rose hip and seed powder, LitozinR, seems to deserve further, more definitive studies as a possible option in long‐term management of NSLBP with or without osteoarthritic pain. Copyright © 2008 John Wiley & Sons, Ltd.
Chemoprotective effects of a protein from the red algaePorphyra yezoensison acetaminophen‐induced liver injury in rats
Authors: Hwang Hye‐Jung , Kwon Mi‐Jin , Kim In‐Hye , Nam Taek‐Jeong 
Published: August 2008

AbstractSeaweeds contribute to the maintenance of health through their nutritional and medicinal properties. The effects of PYP, a 14 kDa protein isolated from a hot‐water extract of the marine algaPorphyra yezoensis, on AAP‐induced liver injury in rats was evaluated. AAP induced acute liver injury and AAP‐induced hepatotoxicity is the leading cause of liver failure. In this study, male Sprague–Dawley rats were assigned to one of three treatment groups: control, AAP, or AAP + PYP. Compared with the control group, liver tissue from the AAP group showed increased levels of caspase‐3 activity and DNA fragmentation, decreased levels of GSH and increased serum GOT/GPT levels. In contrast, treatment with AAP + PYP produced levels of caspase‐3 activity, DNA fragmentation, GSH and GOT/GPT that matched the values seen in the control group. It is concluded that PYP may prevent AAP‐induced liver injury. Copyright © 2008 John Wiley & Sons, Ltd.
A direct and rapid leaf water extraction method for isotopic analysis
Authors: Peters L. I. , Yakir D. 
Published: August 2008

AbstractIsotopic measurements of leaf water have provided insights into a range of ecophysiological and biogeochemical processes, but require an extraction step which often constitutes the major analytical bottleneck in large‐scale studies. Current standard procedures for leaf water analysis are based on cryogenic vacuum or azeotrophic distillation, and are laborious, require sophisticated distillation lines and the use of toxic materials. We report a rapid technique based on centrifugation/filtration of leaf samples pulverised in their original sampling tubes, using a specifically adapted, simple apparatus. The leaf water extracts produced are suitable for isotopic analysis via pyrolysis gas chromatography isotope ratio mass spectrometry (PYR/GC/IRMS). The new method was validated against cryogenic vacuum distillation and showed an overall accuracy of ±0.5‰ (nine grouped comparisons, n = 110) over a range of 21‰. Effects due to the presence of soluble carbohydrates were near the detection limits for most samples analysed, and these effects could be corrected for (the extracted soluble organics could also be used for isotopic analysis). The extraction time for a routine eight‐sample subset was reduced from 4 h (cryogenic distillation) to 45 min, limited only by the size of the centrifuge(s) used. This method provides a rapid, low‐cost and reliable alternative to conventional vacuum and other distillation methods that can alleviate current restrictions on ecosystem‐ and global‐scale studies that require high‐throughput leaf water isotopic analysis. Copyright © 2008 John Wiley & Sons, Ltd.
Autofluorescence spectroscopy and imaging of Platymonas subcordiformis irradiated by diode laser based on LSCM
Authors: Huang Zufang , Chen Rong , Li Yongzeng , Zhuang Huiru , Chen Jianxin , Wang Lijiang 
Published: August 2008

AbstractAutofluorescence spectra and optical imaging of Platymonas subcordiformis after irradiation of diode laser were observed via laser scanning confocal microscopy (LSCM). With 488 nm Ar+ laser excitation, the horizontal and vertical dimensions of a cup‐shaped chloroplast of the irradiation group increased about 10% compared with the control group. The fluorescence spectra were similar between irradiation group and control group with a maximum fluorescence band around 682 nm, whereas the former has a higher intensity. Image of a small circular substance with stronger two‐photon autofluorescence (TPA) was obtained when using two‐photon excitation wavelength of 800 nm in single‐channel mode. Further analysis by the 800 nm excitation based on two independent‐channels mode showed an emission band of the small circular substance around 376–505 nm, which corresponded to the eyespot of P. subcordiformis. In lambda scanning mode, with two‐photon wavelength of 800 nm excitation, six fluorescence peaks that are located at 465, 520, 560, 617, 660 and 680 nm were observed; the fluorescence intensity of the irradiation group was higher than that of the control group, especially at 520, 560 and 617 nm. As a conclusion, diode laser irradiation can promote chloroplast growth of P. subcordiformis cells in the form of expanding area and the increasing content of protein, phospholipids and chlorophyll. LSCM, especially TPA imaging based on femtosecond laser excitation, provides a nondestructive, real‐time and accurate method to study changes of living algal cells under laser irradiation and other environmental factors. SCANNING 30: 443–447, 2008. © 2008 Wiley Periodicals, Inc.
Bayesian adaptive model selection for optimizing group sequential clinical trials
Authors: Wathen J. Kyle , Thall Peter F. 
Published: August 2008

AbstractThis article presents a new approach to the problem of deriving an optimal design for a randomized group sequential clinical trial based on right‐censored event times. We are motivated by the fact that, if the proportional hazards assumption is not met, then a conventional design's actual power can differ substantially from its nominal value. We combine Bayesian decision theory, Bayesian model selection and forward simulation (FS) to obtain a group sequential procedure that maintains targeted false‐positive rate and power, under a wide range of true event time distributions. At each interim analysis, the method adaptively chooses the most likely model and then applies the decision bounds that are optimal under the chosen model. A simulation study comparing this design with three conventional designs shows that, over a wide range of distributions, our proposed method performs at least as well as each conventional design, and in many cases it provides a much smaller trial. Copyright © 2008 John Wiley & Sons, Ltd.
Seamlessly integrating similarity queries in SQL
Authors: Barioni M. C. N. , Razente H. L. , Traina A. J. M. , Traina C. 
Published: August 2008

AbstractModern database applications are increasingly employing database management systems (DBMS) to store multimedia and other complex data. To adequately support the queries required to retrieve these kinds of data, the DBMS need to answer similarity queries. However, the standard structured query language (SQL) does not provide effective support for such queries. This paper proposes an extension to SQL that seamlessly integrates syntactical constructions to express similarity predicates to the existing SQL syntax and describes the implementation of a similarity retrieval engine that allows posing similarity queries using the language extension in a relational DBMS. The engine allows the evaluation of every aspect of the proposed extension, including the data definition language and data manipulation language statements, and employs metric access methods to accelerate the queries. Copyright © 2008 John Wiley & Sons, Ltd.
Ten factors that impede improvement of verification and validation processes in software intensive organizations
Authors: García Javier , de Amescua Antonio , Velasco Manuel , Sanz Ana 
Published: August 2008

AbstractIn spite of the potential benefits that the correct application of software verification and validation processes, techniques and tools can provide, their institutionalized use in the software industry does not reach the minimum capability levels required to gain these benefits. Moreover, this circumstance is aggravated in the small and medium SIOs because of the lack of available human and economic resources.In this paper, ten of the most important factors that prevent the correct institutionalization of the software verification and validation efficient practices are presented. These factors are obtained from the authors' experience in several software process improvement initiatives in software verification and validation processes. Copyright © 2008 John Wiley & Sons, Ltd.
Color modulation for intramolecular charge‐transfer‐induced chemiluminescence of 1,2‐dioxetanes
Authors: Matsumoto Masakatsu , Watanabe Nobuko , Hoshiya Naoyuki , Ijuin Hisako K. 
Published: August 2008

AbstractDioxetanes bearing an aromatic electron donor decompose with an accompanying emission of light by an intramolecular charge‐transfer‐induced chemiluminescence (CTICL) mechanism. The color of the chemiluminescence from CTICL‐active aryl‐substituted dioxetanes is controlled by the design of the aromatic moiety and its substitution pattern, and the substituent on the carbon of the dioxetane ring. In addition to these color modulations, a change in the conformation of dioxetanes bearing a biaryl group was also found to cause a change in the color of CTICL in the coordination sphere of a crown ether complex. This new color modulation system was further developed for optically active dioxetanes bearing 2‐hydroxy‐1,1′‐binaphthyl, the CTICL of which took place under the chiral recognition of optically active crown ether complexes. The spectra of the chemiluminescence from biaryl‐type dioxetanes did not coincide with the fluorescence spectrum from the authentic emitter in the coordination sphere, but they did coincide with each other in a completely homogeneous system. This finding suggests that the emitter of CTICL possesses a transient structure, which retains the afterimage of the conformation of the dioxetane. © 2008 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 8: 213–228; 2008: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20150
Optimization of transformer noise level by reverse calculation using linear programming
Authors: Tanaka Hideaki , Yamashita Daiki , Yokoyama Ryuichi 
Published: August 2008

AbstractThis paper proposes a simple and practical method of determination of optimal acoustic noise levels of transformers to be replaced in an aged substation. The proposed algorithm is based on linear programming using an empirical formula for estimating noise levels at the boundary points around the substation premises. Necessary input parameters are the three dimensions of each transformer and the distance between transformers and each boundary point. Constraints are derived from the empirical noise‐level estimation formula and the regulated noise levels at the boundary. An equivalent sum of transformer noise levels is selected as an objective function to be maximized. The proposed method was successfully tested on a model substation. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Dynamic ant programming for automatic construction of programs
Authors: Shirakawa Shinichi , Ogino Shintaro , Nagao Tomoharu 
Published: August 2008

AbstractA new method for automatic programming is proposed in this paper. Automatic programming is the method of generating computer programs automatically. Genetic programming (GP) is a typical example of automatic programming. GP evolves computer programs with tree structure based on genetic algorithm (GA). The new method is named dynamic ant programming (DAP). DAP is based on ant colony optimization (ACO) and uses dynamically changing pheromone table. The nodes (terminal and nonterminal) are selected using the value of pheromone table. The higher the rate of pheromone, the higher is the probability that it can be chosen. Although the search space (i.e., the pheromone table of DAP) is dynamically changing, the ants find good solution using portions of solutions, which are of pheromone value. We describe the method of construction of tree structure using ACO, as well as pheromone update and deletion and insertion of nodes in detail. DAP is applied to the symbolic regression problem that is widely used as a test problem for GP system. We compare the performance of DAP to GP and show the effectiveness of DAP. In order to investigate the influence of several parameters, we compare experimental results obtained using different settings. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Ultrasonographic visualization of balloon placement for uterine tamponade in massive primary postpartum hemorrhage
Authors: Cho Y. , Rizvi C. , Uppal T. , Condous G. 
Published: August 2008

AbstractThis case report is the first documentation of ultrasonographic confirmation of positioning of a Sengstaken‐Blakemore balloon catheter (SBEC) in the management of massive postpartum hemorrhage. The sonongraphic position, while incorrect according to conventional use of uterine balloon catheters, raises the possibility of an alternative mechanism of action of the balloon: not uterine cavity tamponade but hydrostatic pressure directly around the uterine arteries, a mechanism akin to mechanical uterine artery embolization or ligation. If this hypothesis is correct, it not only elucidates how balloon tamponade works but also challenges current thinking on how postpartum hemorrhage should be managed effectively. Future studies are required to corroborate this hypothesis and we believe that sonographic confirmation of balloon catheter location should be an integral part of uterine balloon tamponade in women with massive primary postpartum hemorrhage. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of right pulmonary artery to left atrium communication
Authors: Rama Murthy B. S. , Krishna S. R. , Rao P. M. 
Published: August 2008

AbstractWe report a case of right pulmonary artery to left atrium communication in a fetus at 24 weeks' gestation. Fetal echocardiography showed dilatation of the left atrium and main and right pulmonary arteries. The right pulmonary artery was seen to communicate with the left atrium. Color Doppler velocimetry demonstrated high‐velocity flow through the communication. The pregnancy was terminated and findings were confirmed at autopsy. The embryological and postnatal aspects of right pulmonary artery to left atrium communication are discussed. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.