bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constant versus Time‐Varying Beta Models: Further Forecast Evaluation
Authors: Reeves Jonathan J. , Wu Haifeng 
Published: December 2011

ABSTRACTRecent advances in the measurement of beta (systematic return risk) and volatility (total return risk) demonstrate substantial advantages in utilizing high‐frequency return data in a variety of settings. These advances in the measurement of beta and volatility have resulted in improvements in the evaluation of alternative beta and volatility forecasting approaches. In addition, more precise measurement has also led to direct modeling of the time variation of beta and volatility. Both the realized beta and volatility literature have most commonly been modeled with an autoregressive process. In this paper we evaluate constant beta models against autoregressive models of time‐varying realized beta. We find that a constant beta model computed from daily returns over the last 12 months generates the most accurate quarterly forecast of beta and dominates the autoregressive time series forecasts. It also dominates (dramatically) the popular Fama–MacBeth constant beta model, which uses 5 years of monthly returns. Copyright © 2011 John Wiley & Sons, Ltd.
Delayed yet persistent hippocampal molecular and structural alteration after learning: New players in the debate on time‐dependent long‐lasting memory processes
Authors: Routtenberg Aryeh , Tabatadze Nino , McGonigal Rhona 
Published: December 2011

AbstractTwo articles in this issue concern the presynaptic structural remodeling and the molecular events that are important novel mechanisms underlying long‐term memory storage processes. © 2011 Wiley Periodicals, Inc.
Selective presynaptic terminal remodeling induced by spatial, but not cued, learning: A quantitative confocal study
Authors: McGonigal R. , Tabatadze N. , Routtenberg A. 
Published: December 2011

AbstractThe hippocampal mossy fibers (MFs) are capable of behaviorally selective, use‐dependent structural remodeling. Indeed, we previously observed a new layer of Timm's staining induced in the stratum oriens (SO) in CA3 after spatial but not cued water maze learning (Rekart et al., (2007) Learn Mem 14:416‐421). This led to the prediction that there is a learning‐specific induction of presynaptic terminal plasticity of MF axons. This study confirms this prediction demonstrating, at the confocal level of analysis, terminal‐specific, and behavior‐selective presynaptic structural plasticity linked to long‐term memory. Male adult Wistar rats were trained for 5 days to locate a hidden or visible platform in a water maze and a retention test was performed 7 days later. MF terminal subtypes, specifically identified by an antibody to zinc transporter 3 (ZnT3), were counted from confocal z‐stacks in the stratum lucidum (SL) and the SO. In hidden platform trained rats, there was a significant increase in the number of large MF terminals (LMTs, 2.5–10 μm diameter, >2 μm2 area) compared to controls both in the proximal SL (P < 0.05) and in the SO (P < 0.01). Surprisingly, there was no detectable increase in small MF terminals (SMTs, 0.5–2 μm diameter, <2 μm2 area) in either SL or SO as a consequence of training. This distinction of the two MF terminal types is functionally important as LMTs synapse on CA3 pyramidal neurons, while SMTs are known to target inhibitory interneurons. The present findings highlight the pivotal role in memory of presynaptic structural plasticity. Because the “sprouting” observed is specific to the LMT, with no detectable change in the number of the SMT, learning may enhance net excitatory input to CA3 pyramidal neurons. Given the sparse coding of the MF‐CA3 connection, and the role that granule cells play in pattern separation, the remodeling observed here may be expected to have a major impact on the long‐term integration of spatial context into memory. © 2011 Wiley Periodicals, Inc.
Microwave Preparation of Ag Nanoparticles for Chemiluminescence Enhancement
Authors: Creixell‐Echeagaray Santiago , Ibanez Jorge G. , Borghino‐De La Pena Rodrigo , Corea Monica , Ramírez‐Menesesa Esther 
Published: December 2011

AbstractChemiluminescence applications frequently require signal enhancement. We report a major improvement of the chemiluminescence of luminol in alkaline peroxide solutions by silver nanoparticles prepared by chemical reduction of AgNO3 by NaH2PO2 in ethylene glycol solution, with polyvinylpirrolidone as capping agent and using a simple microwave approach and set up. The luminescence emission is also shown to be much faster. The nanoparticles were characterized spectroscopically and by dynamic light scattering showing an average particle size of 36 nm.
Comparative Studies on the Quick Recognition of Melamine Using Unmodified Gold Nanoparticles and p‐Nitrobenzenesulfonic Grafted Silver Nanoparticles
Authors: Bai Lian‐Yang , Dong Cai‐Xia , Zhang Yu‐Ping , Li Wei , Chen Jun 
Published: December 2011

AbstractBoth unmodified gold nanoparticles (AuNPs) and p‐nitrobenzenesulfonic (p‐NBS) grafted silver nanoparticles (AgNPs) were prepared by chemical synthesis, respectively. They could be used for visual detection via the interaction with the twelve amide compounds including melamine. These color changes could be seen with the naked eye directly and monitored by ultraviolet visible (UV‐Vis) absorbance spectra. The recognition mechanism for both nanoparticles was comparatively investigated by the addition of glutathione (GSH) in the presence of melamine, respectively. The triple hydrogen bonding recognition and the attractive van der Waals interactions between melamine (0.5 mg/L) and AuNPs were responsible for the color change during its aggregation (red‐to‐purple or blue), whilst the electron donor‐acceptor interaction between melamine (0.2 mg/L) and p‐NBS modified on the surface of AgNPs resulted in the color changes (yellow‐to‐grey or dark green).
A Novel Hydrogen Peroxide Biosensor Based on the PDDA‐GNPs/MWNTs Nanocomposite Matrix
Authors: Sun Aili , Zheng Jianbin , Sheng Qinglin 
Published: December 2011

AbstractA novel nanocomposite designed by the assembly of the positively charged poly(diallyldimethylammonium chloride) protected gold nanoparticles (PDDA‐GNPs), and the negatively charged multi‐walled carbon nanotubes (MWCNTs) on ITO electrode via electrostatic interaction, was used as a supporting matrix for immobilizing hemoglobin (Hb) to develop a high‐performance hydrogen peroxide (H2O2) biosensor. The cyclic voltammetrys of immobilized Hb showed a pair of well‐defined and quasi‐reversible redox peaks with the formal potential of ‐0.205V (vs. SCE) and the peak‐to‐peak potential separation of 44 mV at a scan rate of 100 mV×s−1 in 0.1 mol×L−1 pH 7.0 PBS. Under the optimized experimental conditions, a linearity range for determination of H2O2 was from 2.0 × 10−6 to 5.2 × 10−4 mol×L−1 with a correlation coefficient of 0.9994 (n = 37) and a detection limit of 8.4 × 10−7 mol×L−1. The biosensor displayed excellent electrochemical and electrocatalytic response to the reduction of H2O2, high sensitivity, long‐term stability, good bioactivity and selectivity.
Microwave‐assisted Synthesis of Novel 3,4‐Bis‐chalcone‐N‐arylpyrazoles and Their Anti‐inflammatory Activity
Authors: Abdel‐Aziz Hatem A. , Al‐Rashood Khalid A. , ElTahir Kamal Eldin H. , Ibrahim Hany S. 
Published: December 2011

AbstractA series of 3,4‐bis‐chalcone‐N‐arylpyrazoles 3a‐h was prepared conveniently from diacetyl pyrazoles 2a,b. All reactions were carried out under conventional thermal heating and/or microwave irradiation. The structure of the latter functionally pyrazoles was confirmed under the bases of their IR, mass, 1H NMR and 13C NMR. The X‐ray diffraction of compound 3e not only confirmed the chemical structure of 3a‐h, but also showed the E configuration of their chalcone moieties. Treatment of compound 3e with phenyl hydrazine in presence of acetic acid afforded the tri‐pyrazle 4. The anti‐inflammatory activity of the newly synthesized compounds was investigated. Some of these compounds showed a moderate activity when compared with indomethacin as a reference drug. The combination between chalcone and pyrazole moieties revealed a variable effect in anti‐inflammatory activity.
Screening and Identification of Peptides that Bind Specifically to the X gene Promoter of Hepatitis B Virus Using a Combinatorial Peptide Library Approach
Authors: Liao Hsien‐Hua , Nawarak Jiraporn , Chang Ken‐lin , Hsieh Wei‐Ying , Tsai Hsien‐Yu , Chen Shui‐Tein , Cheng Sun‐Long 
Published: December 2011

AbstractHepatitis B virus (HBV) X protein (HBx) plays a key role in the development of hepatocellular carcinoma (HCC) in HBV carriers. A drug that can bind to the promoter region of HBV may shut down the expression of HBx and subsequently prevent the development of HCC in the HBV carrier. We have constructed a seven amino acid residue peptide library on a TentaGel resin using a combinatorial one‐bead one‐sequence peptide synthesis method. The fluorescently labeled eicosanucleotide (5′‐(6‐FAM) CTTTTGGGCT TTGCTGCCCC‐3′) of the HBx promoter region was used as a monitor to screen for peptides that have high binding affinity to the HBx promoter. Two heptapeptides, KAPLFSI and SRVRMTW, were identified, and synthesized. The binding affinities of the peptides to the HBx promoter oligonucleotide were determined using Surface Plasmon Resonance (SPR). The peptide KAPLFSI had a greater binding affinity constant (ka) and equilibrium constant (KD) than SRVRMTW. The ka and KD values with the full X‐promoter sequence were found to be 1.425 E+5 (1/Ms) and 1.186 E‐8 (M), respectively. The peptide may open a new route for tumor suppression in HBV carriers.
Development of Dispersive Liquid‐Liquid Microextraction Based on Solidification of Floating Organic Drop for the Determination of Trace Cobalt in Water Samples
Authors: Zhang Jing‐Wen , Ke Xiao‐Jing , Wang Yu‐Kun , Du Xin , Ma Jing‐Jun , Li Jing‐Ci 
Published: December 2011

AbstractA liquid‐phase microextraction technique was developed using dispersive liquid‐liquid microextraction based on solidification of floating organic drop combined with flame atomic absorption spectrometry, for the extraction and determination of trace amounts of cobalt in water samples. Microextraction efficiency factors, such as the type and volume of extraction and dispersive solvents, pH, extraction time, the chelating agent amount, and ionic strength were investigated and optimized. Under optimum conditions, an enrichment factor of 160 was obtained from 10.0 mL of water sample. The calibration graph was linearin the range of 1.15‐110 μg L−1 with a detection limit of 0.35 μg L−1. The relative standard deviation for ten replicate measurements of 10 and 100 μg L−1 of cobalt were 3.26% and 2.57%, respectively. The proposed method was assessed through the analysis of certified reference water or recovery experiments.
Determination of Adrenaline by Atomic Absorption Spectrometry Using Copper as Probe Reagent in Pharmaceutical and Serum Samples
Authors: Zheng Li‐qing , Liu Li‐tao , Li Jing , Li Quan‐min 
Published: December 2011

AbstractIn this paper, an atomic absorption spectrometric method has been established to determine adrenaline using Cu(II) as probe reagent. In the presence of SCN−, it has been demonstrated that Cu(II) is reduced to Cu(I) by adrenaline at pH 6.0, and the in situ formed Cu(I) reacts with SCN‐ to form the white emulsion of CuSCN. According to the amount of residual Cu(II) which is measured by atomic absorption spectrometry, the amount of adrenaline can be determined indirectly. Beer's law is obeyed in the range of adrenaline concentration of 0.080‐6.00 mg mL‐1, and the linear regression equation is A = 0.20342 ‐ 0.02756C (μg mL−1) with a correlation coefficient of 0.9998. The detection limit is 0.033 μg mL−1 and R.S.D. is 0.56%. This method has been successfully applied to determine adrenaline in pharmaceutical and serum samples with satisfactory results.
Kinetic and Thermodynamic Investigations of Zn(II) Adsorption on Microcrystalline Anthracene Modified with 8‐Hydroxyquinoline and Its Application to the Preconcentration and Determination of Trace Zinc
Authors: Wang Xu , Zhang Yan , Li Quan‐min 
Published: December 2011

AbstractA new method that utilizes microcrystalline anthracene modified with 8‐hydroxyquinoline as an adsorbent has been developed for the preconcentration of trace Zinc(II). The possible reaction mechanism is discussed in detail. The influences of different parameters, such as acidity, other metal ions, the amounts of 8‐hydroxyquinoline and anthracene, etc. on the enrichment yield of Zn(II) have been studied to optimize the experimental conditions. The experimental data were fitted well with the pseudo‐second‐order kinetic model and Langmuir model at all studied temperatures and the maximum adsorption capacity was 32.58 mg·g−1 (300 K). The thermodynamic parameters (ΔGθ, ΔHθ and ΔSθ) showed the feasibility, exothermic and spontaneous nature of the adsorption at 280∼320 K. Experiments indicate that Zn(II) can be completely separated from Cu(II), Co(II), Cd(II), Mn(II), Ni(II) in the eluent. The recovery of this method is in the range of 96.0%∼105.0% with preconcentration factor of 100 and the limit of detection after preconcentration is 0.068 μg·L−1. The proposed method has been successfully applied to the determination of trace Zn(II) in effluents and synthetic water sample having a composition similar to certified water sample SLRS‐4 (NRC, Canada). Analytical results obtained by this recommended method were very satisfactory.
Small embeddings for partial 5‐cycle systems
Authors: Martin Geoffrey , McCourt Thomas A. 
Published: December 2011

AbstractIt has been conjectured that any partial 5‐cycle system of orderucan be embedded in a 5‐cycle system of ordervwheneverv≥3u/2+1andv≡1,5 (mod 10). The smallest known embeddings for any partial 5‐cycle system of orderuis10u+5. In this paper we significantly improve this result by proving that for any partial 5‐cycle system of orderu≥255, there exists a 5‐cycle system of order at most(9u+146)/4into which the partial 5‐cycle system of orderucan be embedded. © 2011 Wiley Periodicals, Inc. J Combin Designs
Synthesis and antimicrobial activities of new 4,6‐diaryl‐ 4,5‐dihydro‐3‐hydroxy‐2H‐indazoles
Authors: Amutha Parasuraman , Nagarajan Samuthira 
Published: December 2011

AbstractA series of new 4,6‐diaryl‐4,5‐dihydro‐3‐hydroxy‐2H‐indazoles 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k were synthesized by the cyclization of ethyl 2‐oxo‐4,6‐diarylcyclohex‐3‐ene carboxylates 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k. The compounds were characterized by IR, 1H NMR, 13C NMR, 2D NMR, and elemental analysis. The synthesized compounds were evaluated for in vitro antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Pseudomonas aeruginosa, Candida albicans, Aspergillus niger, Aspergillus flavus, and Rhizopus sp. Most of the compounds exhibited good activity against the tested organisms. J. Heterocyclic Chem.,, (2012).
Accurate modeling of microwave devices using kriging‐corrected space mapping surrogates
Authors: Koziel Slawomir , Bandler John W. 
Published: December 2011

SUMMARYWe present an accurate modeling technique that exploits standard space mapping (SM) as a trend function and the correction layer implemented with kriging. The kriging process allows us to efficiently utilize all available fine model data (not possible in the standard SM approach) and to obtain accuracy better than both the SM and recently published combinations of SM and radial basis function interpolation and fuzzy systems. We present application examples of design optimization and statistical analysis of several microwave filters. Copyright © 2011 John Wiley & Sons, Ltd.
Use of indirect comparison methods in systematic reviews: a survey of Cochrane review authors
Authors: Abdelhamid Asmaa S. , Loke Yoon K. , Parekh‐Bhurke Sheetal , Chen Yen‐Fu , Sutton Alex , Eastwood Alison , Holland Richard , Song Fujian 
Published: December 2011

Because of insufficient evidence from direct comparison trials, the use of indirect or mixed treatment comparison methods has attracted growing interest recently. We investigated the views and knowledge of Cochrane systematic review authors regarding the use of indirect comparison and related methods in the evaluation of competing healthcare interventions.An online survey was sent to 84 authors of Cochrane systematic review reviews between January and March 2011. The response rate was 57%. Most respondents (87%) had heard of/had some knowledge of indirect comparison, and 23% actually used indirect comparison methods. Some were suspicious of the methods (9%). Most authors (89%) felt they needed more training, especially in assessing the validity of indirect evidence. Almost all felt that the validity of indirect comparison could potentially be influenced by a large number of effect modifiers. Many reviewers (76%) accepted that indirect evidence is needed as it may be the only source of information for relative effectiveness of competing interventions, provided that review authors and readers are conscious of its limitations. Time commitment and resources needed were identified as an important concern for Cochrane reviewers.In summary, there is an acceptance of the increasing demand for indirect comparison and related methods and an urgent need to develop structured guidance and training for its use and interpretation. Copyright © 2011 John Wiley & Sons, Ltd.
The clinical implications of antitumor immunity in head and neck cancer
Authors: Allen Clint T. , Judd Nancy P. , Bui Jack D. , Uppaluri Ravindra 
Published: December 2011

AbstractRecent developments have renewed interest in understanding the interaction between transformed cells and the immune system in the tumor microenvironment. Here, we provide a comprehensive review addressing the basics of tumor immunology in relation to head and neck cancer and the cellular components potentially involved in antitumor immune responses. In addition, we describe the mechanisms by which head and neck cancer cells escape immune‐mediated killing and progress to form clinically significant disease. Further, we detail what effects standard anticancer therapies may have on antitumor immune responses and how these responses may be altered by current and investigational immunotherapies. Finally, we discuss future directions that need to be considered in the development of new immunotherapeutics designed to durably alter the immune response in favor of the host.Laryngoscope, 122:144–157, 2012
Does mucosal remodeling in chronic rhinosinusitis result in irreversible mucosal disease?
Authors: Bassiouni Ahmed , Naidoo Yuresh , Wormald Peter‐John 
Published: December 2011

AbstractMucosal remodeling in the sinuses is a recently described phenomenon in which the mucosa undergoes potentially irreversible changes as a result of ongoing underlying inflammatory processes. Research into remodeling that occurs in the bronchial airways in asthmatic patients has led to modification of asthma treatment guidelines. However, remodeling in the sinuses has still not led to changes in current medical or surgical management of chronic rhinosinusitis. Upper airway remodeling constitutes a new area of research that poses many unanswered clinical questions and may potentially alter the management of patients with severe chronic rhinosinusitis.Laryngoscope, 122:225–229, 2012
Comprehensive assessment of thyroidectomy skills development: A pilot project
Authors: Diaz Voss Varela David A. , Malik Mohammad U. , Thompson Carol B. , Cummings Charles W. , Bhatti Nasir I. , Tufano Ralph P. 
Published: December 2011

AbstractObjectives/Hypothesis:To test the validity, reliability, and feasibility of an evaluation tool designed to measure the development of trainees' surgical skills in the operating room for thyroid surgery.Study Design:Prospective validation study.Methods:A modified Delphi technique was employed to develop a new Objective Structured Assessment of Technical Skills–based instrument for thyroid surgery. During a 1‐year period, 16 otolaryngology–head and neck surgery residents (ranging from postgraduate year 2 to 6) and one endocrine surgery fellow were evaluated by one faculty member obtaining a total of 94 evaluations. Performance was rated using a task‐based checklist (TBC) and a global rating scale (GRS). The TBC measured trainees' thyroidectomy technical skills, and the GRS assessed their overall surgical performance.Results:Based on four clinical levels (junior, intermediate, senior, and surgical fellow) our tool demonstrated construct validity for both components of the assessment instrument, specifically for the TBC showing a mean difference of 0.9 (95% confidence interval: 0.5‐1.3, P < .001) between the contiguous clinical levels senior versus intermediate. Cronbach α, a measure of internal consistency, was 0.96 for both components of the instrument. The correlation between the TBC and GRS was also high within trainee (r = 0.62, n = 94, P < .001) and across trainees (r = 0.96, n = 17, P < .001).Conclusions:Our tool proved to be a valid, reliable, and feasible instrument for assessing competency in thyroid surgery. It is effective in providing timely formative feedback during and upon the conclusion of the surgical procedure by identifying procedural tasks for which additional training is necessary. In addition, it enables longitudinal tracking of residents' surgical performance, thus ensuring their appropriate development. Laryngoscope, 122:103–109, 2012
Acyclic Triene Metathesis Polymerization of Plukenetia Conophora Oil: Branched Polymers by Direct Polymerization of Renewable Resources
Authors: Akintayo Cecilia O. , Mutlu Hatice , Kempf Michael , Wilhelm Manfred , Meier Michael A. R. 
Published: December 2011

AbstractOil from the Plukenetia conophora seed, a tropical oilseed consisting mainly of linolenic acid, is polymerized via acyclic triene metathesis using different ruthenium benzylidene and indenylidene catalysts to yield highly branched and functionalized polyesters. The influence of the synthesis conditions on the structure and molar mass characteristics of the obtained hyperbranched polyesters as well as an in‐depth melt and solution material property investigation are presented.
Durability of advanced fabricated structures
Authors: Marquis G. B. 
Published: December 2011

AbstractMaterials and fabrication technologies for welded structures are continually evolving and developing. The drives to reduce weight and cost, increase energy efficiency, improve performance and reduce the environmental footprint of end products that included welded structures continue to provide challenges in the fatigue design and production of welded structures. This presentation attempts to provide a brief overview of selected research topics and recent technological developments related to fatigue assessment for welded structures. Much of the work has been performed and reported within the scope of the International Institute of Welding (IIW), but other groups and individuals have also made important contributions. While many themes could have been selected, this paper provides brief discussions on several active research topics: the definition of weld quality for fatigue performance, advanced high strength steel for welded structures, high frequency mechanical impact treatment and developments in fatigue assessment procedures.