bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chip‐based enantioselective open‐tubular capillary electrochromatography using bovine serum albumin‐gold nanoparticle conjugates as the stationary phase
Authors: Li Hai‐Fang , Zeng Hulie , Chen Zhifeng , Lin Jin‐Ming 
Published: March 2009

AbstractIn this study, chip‐based enantioselective open‐tubular CEC (OT‐CEC) was developed employing BSA‐gold nanoparticle (GNP) conjugates as a chiral stationary phase. An immobilization procedure was realized by prederivatization of the glass microchannel with (3‐mercaptopropyl)‐trimethoxysilane to provide thiol groups, which linked the BSA‐GNP conjugates on the inner surface of the microchannels. Incorporation of GNPs into immobilization of BSA selectors greatly increased the BSA phase ratio and favored the BSA stationary phase generated sufficient EOF. Good resolutions of FITC‐labeled ephedrine and norephedrine isomers were achieved with 36 mm effective separation channel length within 250 s. The constructed OT‐CEC microdevice exhibited good repeatabilities for run‐to‐run enantioseparations and kept an enantioselective lifetime of more than 1 month. The effects of pH values and concentrations of a running buffer on the selectivity and resolution of enantioseparations were investigated.
Adapted liquid crystal display backlighting unit for densitometry of stained polyacrylamide electrophoresis gels
Authors: Tan Han Yen , Ng Tuck Wah , Liew Oi Wah 
Published: March 2009

AbstractAppropriate monochromatic illumination that is spatially uniform will ensure densitometry of stained polyacrylamide electrophoresis gels with high sensitivity and repeatability. The approach of using an array of LEDs as an illuminator has practical limitations. Here we describe an alternative method based on adapted liquid crystal display backlighting. By changing the fluorescent light source and using a region where light intensity is uniform, we demonstrate the ability to achieve highly sensitive and repeatable densitometry measurements of polyacrylamide electrophoresis gels with Coomassie‐stained proteins.
Performance of agarose IEF gels as the first dimension support for non‐denaturing micro‐2‐DE in the separation of high‐molecular‐mass plasma proteins and protein complexes
Authors: Jin Ya , Manabe Takashi 
Published: March 2009

AbstractAgarose micro‐column gels (1% w/v agarose, diameter 1.4 mm and length 35 mm) were prepared as the first‐dimension IEF support for non‐denaturing 2‐DE and the performance was compared with that of polyacrylamide gels (4.2% T and 4.8% C, the same gel size) using a human plasma sample. Sorbitol was not added in the agarose IEF gels, since its presence not only delayed the focusing of the proteins but also deteriorated the protein resolution. The optimum IEF time of the agarose gels for separation of 2 μL plasma sample (ca. 120 μg proteins) was decided to be 46 min, which is much shorter than that of the polyacrylamide gels (75 min). MALDI‐MS and PMF assignment of the spots on the micro‐2‐DE gels at apparent molecular mass above ca. 5×102 kDa and pI from 4 to 8 revealed that when polyacrylamide IEF gels were used, many of the high‐molecular‐mass proteins resided at the sample loading edge or in basic pI regions as smear bands. When agarose IEF gels were used, most of the high‐molecular‐mass proteins moved to more acidic pI positions and were better focused, and their apparent pI values matched well with those previously reported for purified proteins. These results demonstrated the advantages of agarose‐IEF/2‐DE for the separation of high‐molecular‐mass proteins and protein complexes under non‐denaturing conditions.
Using hydrogen‐rich multifuel to improve energy efficiency and reduce CO2 emission for high‐energy furnace
Authors: Hsieh Shih‐Chieh , Jou Chih‐Ju G. 
Published: March 2009

AbstractThe waste gas generated in petrochemical manufacturing processes, such as the catalytic reforming, catalytic cracking, and other petrochemical units contains complex components, which are worth recovery and reuse. In this research, replacing the natural gas (NG) partially with a hydrogen‐rich multifuel (MG) is tested onsite to power a full‐scale furnace (70% loading) used in a distillation operation. When the NG is mixed with MG, the mixture contains 30–80% H2 (average 60%), and its thermal NOx is the dominant NOx formation mechanism. The formation of nitrogen oxides increases by 42.0–42.1 mL/m3 (ppmv), thus reducing 2.2 × 103 tons of annual CO2 production or achieving savings of 5.7–5.9 × 103 m3/yr NG usage. However, if MG replaces NG as the major fuel gas, the prompt NOx is the dominant NOx formation mechanism. Therefore, the MG can be used as a low‐cost alternative to achieve savings on fuel cost and reduce CO2 emission. © 2009 American Institute of Chemical Engineers Environ Prog, 2009
Retrieval of suspended sediment concentrations in large turbid rivers using Landsat ETM+: an example from the Yangtze River, China
Authors: Wang Jian‐Jun , Lu Xi Xi , Liew Soo Chin , Zhou Yue 
Published: March 2009

AbstractSuspended sediment concentration (SSC) is a critical parameter in the study of river sediment transport and water quality variation, but traditional measurement methods are costly and time‐consuming. This paper is focused on presenting a methodology that may be useful in estimating SSC which is of key importance in process geomorphology and hydrology. In previous studies, remote sensing has been applied to estimate the SSC of sea waters as well as low turbid inland waters like lakes, reservoirs and short river reaches visible within a single Landsat satellite image coverage. Rivers, especially highly turbid large rivers, have largely been ignored. The dataset used in this paper includes measured SSC and multi‐temporal Landsat ETM+ images covering most part of the Yangtze River. Using an effective easy‐to‐use atmospheric correction method that does not require in situ atmospheric conditions, retrieved water reflectance of Band 4 was found to be a good SSC indicator within the large SSC range 22–2610 mg l–1. The newly developed regression relation between SSC and water reflectance of Band 4 appears to be able to provide a relatively accurate SSC estimate directly from Landsat ETM+ images for the Yangtze River from the upper, the middle to the lower reaches. With the relation it is possible to estimate or map out SSC dynamics of large rivers which lack SSC data due to constraints of conventional measurements. Copyright © 2009 John Wiley & Sons, Ltd.
An oligopolistic model considering the locational SR requirement for joint energy‐reserve market
Authors: Jianlin Yang , Zheng Yan , Donghan Feng 
Published: March 2009

AbstractTo ensure the delivery of spinning reserve (SR) under predicted contingency conditions, zone‐based SR procurement mechanism should be taken into account in practice. An oligopolistic model considering locational SR requirement in joint energy and SR market is proposed in this paper. Every pre‐defined SR zone has its own SR requirement, and the relevant SR could be procured not only from the locational generators, but also from the generation resources outside this locational SR areaviathe tie line interface. Each GenCo is assumed to manipulate the energy price by means of the conjectured supply function; and the coupling effect between energy price and SR price is also analyzed. A 6‐bus system and the IEEE 30‐bus system are simulated to validate the proposed model; the test results show that the locational SR requirement could make the SR distribution more rational, while demand surplus may decrease due to less energy supply in the locational SR area. Besides, the zonal SR price in the oligopolistic market is usually less than that in the competitive market. Copyright © 2009 John Wiley & Sons, Ltd.
Solving time‐dependent PDEs using the material point method, a case study from gas dynamics
Authors: Tran L. T. , Kim J. , Berzins M. 
Published: March 2009

AbstractThe material point method (MPM) developed by Sulsky and colleagues is currently being used to solve many challenging problems involving large deformations and/or fragementations with some success. In order to understand the properties of this method, an analysis of the considerable computational properties of MPM is undertaken in the context of model problems from gas dynamics. The MPM method in the form used here is shown both theoretically and computationally to have first‐order accuracy for a standard gas dynamics test problem. Copyright © 2009 John Wiley & Sons, Ltd.
A transformation‐free HOC scheme for incompressible viscous flows on nonuniform polar grids
Authors: Ray Rajendra K. , Kalita Jiten C. 
Published: March 2009

AbstractWe recently proposed a transformation‐free higher‐order compact (HOC) scheme for two‐dimensional (2‐D) steady convection–diffusion equations on nonuniform Cartesian grids (Int. J. Numer. Meth. Fluids 2004; 44:33–53). As the scheme was equipped to handle only constant coefficients for the second‐order derivatives, it could not be extended directly to curvilinear coordinates, where they invariably occur as variables.In this paper, we extend the scheme to cylindrical polar coordinates for the 2‐D convection–diffusion equations and more specifically to the 2‐D incompressible viscous flows governed by the Navier–Stokes (N–S) equations. We first apply the formulation to a problem having analytical solution and demonstrate its fourth‐order spatial accuracy. We then apply it to the flow past an impulsively started circular cylinder problem and finally to the driven polar cavity problem. We present our numerical results and compare them with established numerical and analytical and experimental results whenever available. This new approach is seen to produce excellent comparison in all the cases. Copyright © 2009 John Wiley & Sons, Ltd.
Global flow instability in a lid‐driven cavity
Authors: Boppana V. B. L. , Gajjar J. S. B. 
Published: March 2009

AbstractThe stability of flow in a lid‐driven cavity is investigated using an accurate numerical technique based on a hybrid scheme with spectral collocation and high‐order finite differences. A global stability analysis is carried out and critical parameters are identified for various aspect ratios. It is found that while there is reasonable agreement with the literature for the critical parameters leading to loss of stability for the square cavity, there are significant discrepancies for cavities of aspect ratios 1.5 and 2. Simulations of the linearized unsteady equations confirm the results from the global stability analysis for aspect ratios A = 1, 1.5 and A = 2. Copyright © 2009 John Wiley & Sons, Ltd.
Estimation and forecasting in first‐order vector autoregressions with near to unit roots and conditional heteroscedasticity
Authors: Pantelidis Theologos , Pittis Nikitas 
Published: March 2009

AbstractThis paper investigates the effects of imposing invalid cointegration restrictions or ignoring valid ones on the estimation, testing and forecasting properties of the bivariate, first‐order, vector autoregressive (VAR(1)) model. We first consider nearly cointegrated VARs, that is, stable systems whose largest root, lmax, lies in the neighborhood of unity, while the other root, lmin, is safely smaller than unity. In this context, we define the ‘forecast cost of type I’ to be the deterioration in the forecasting accuracy of the VAR model due to the imposition of invalid cointegration restrictions. However, there are cases where misspecification arises for the opposite reasons, namely from ignoring cointegration when the true process is, in fact, cointegrated. Such cases can arise when lmaxequals unity and lminis less than but near to unity. The effects of this type of misspecification on forecasting will be referred to as ‘forecast cost of type II’. By means of Monte Carlo simulations, we measure both types of forecast cost in actual situations, where the researcher is led (or misled) by the usual unit root tests in choosing the unit root structure of the system. We consider VAR(1) processes driven by i.i.d. Gaussian or GARCH innovations. To distinguish between the effects of nonlinear dependence and those of leptokurtosis, we also consider processes driven by i.i.d. t(2) innovations. The simulation results reveal that the forecast cost of imposing invalid cointegration restrictions is substantial, especially for small samples. On the other hand, the forecast cost of ignoring valid cointegration restrictions is small but not negligible. In all the cases considered, both types of forecast cost increase with the intensity of GARCH effects. Copyright © 2009 John Wiley & Sons, Ltd.
Prestimulus alpha and mu activity predicts failure to inhibit motor responses
Authors: Mazaheri Ali , Nieuwenhuis Ingrid L.C. , van Dijk Hanneke , Jensen Ole 
Published: March 2009

AbstractDo certain brain states predispose humans to commit errors in monotonous tasks? We used MEG to investigate how oscillatory brain activity indexes the brain state in subjects performing a Go‐noGo task. Elevated occipital alpha and sensorimotor mu activity just prior to the presentation of the stimuli predicted an upcoming error. An error resulted in increased frontal theta activity and decreased posterior alpha activity. This theta increase and alpha decrease correlated on a trial‐by‐trial basis reflecting post‐error functional connectivity between the frontal and occipital regions. By examining the state of the brain before a stimulus, we were able to show that it is possible to predict lapses of attention before they actually occur. This supports the case that the state of the brain is important for how incoming stimuli are processed and for how subjects respond. Hum Brain Mapp, 2009. © 2009 Wiley‐Liss, Inc.
Association between depression and survival or disease recurrence in patients with head and neck cancer enrolled in a depression prevention trial
Authors: Lazure Kathryn E. , Lydiatt William M. , Denman David , Burke William J. 
Published: March 2009

AbstractBackground.To determine if depression portends a worse prognosis in patients with head and neck cancer, we conducted a retrospective chart analysis of subjects who participated in a randomized placebo‐controlled trial of citalopram for the prevention of depression during head and neck cancer treatment. Thirty‐five patients were randomized, 34 with 1 or more evaluations form the basis of this report.Methods.We used the Hamilton Depression Rating Scale (HDRS), with a minimum follow‐up of 24 months if no evidence of disease, or until recurrence or death from disease.Results.Fourteen of 34 subjects were depressed at any time during the 16 week RCT (HAMD >15). Seven of the 14 subjects in the depressed group were dead from disease or had recurrence, compared to 4 of 20 who never developed depression (p = .03). Stage of disease was equivalent in the 2 groups.Conclusion.This study suggests that depression in patients with head and neck cancer reduces survival. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Radiation technique influence on percutaneous endoscopic gastrostomy tube dependence: Comparison between two radiation schemes
Authors: Hatoum Georges F. , Abitbol Andre , Elattar Inas , Lewin Alan , Troner Michael , Kronberg Frank , Raez Luis E. , Weed Donald , Abdel‐Wahab May 
Published: March 2009

AbstractBackground.Our aim was to determine whether percutaneous endoscopic gastrostomy (PEG) dependence was significantly different between 2 prospective trials with different radiation fractionation schemes.Methods.Stage III or IV locally advanced head and neck squamous cell carcinomas arising from the oral cavity, hypopharynx, oropharynx, nasopharynx, paranasal sinuses, or larynx were treated using hyperfractionation (A‐3 protocol) or accelerated fractionation (A‐4 protocol) with chemotherapy. Amifostine was administered 15 to 30 minutes preradiation, at a dose of 500 mg/day in both protocols. It was given as an infusion over 5 to 7 minutes (A‐3 protocol) or subcutaneously (A‐4 protocol). Data regarding PEG placement and removal were collected prospectively.Results.Thirty‐five evaluable A‐3 protocol patients, 14 evaluable A‐4 protocol patients, and 6 patients treated per A‐4 protocol guidelines, but without amifostine as they refused the medication, were included in the analysis. Pretreatment characteristics, such as sex, age, race, T classification, N classification, American Joint Committee on Cancer (AJCC) stage, were compared between the 2 groups of patients. The only significant difference between the 2 groups was AJCC stage. Thirty‐five A‐3 patients and 20 A‐4 patients had overall survivals of 88% versus 80%, 82% versus 75%, and 66% versus 67.5% at 1, 2, and 3 years, respectively (p = .958). With regard to PEG dependence, no significant differences were seen between the 2 groups at 6, 12, or 18 months.Conclusion.PEG dependence was not significantly different between the 2 study groups. Type of altered fractionation scheme may not influence PEG dependence in patients treated with similar protocols. Future randomized studies are needed to confirm these findings. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Temporal patterns of lipoperoxidation and antioxidant enzymes are modified in the hippocampus of vitamin A‐deficient rats
Authors: Fonzo Lorena S. Navigatore , Golini Rebeca S. , Delgado Silvia M. , Ponce Ivana T. , Bonomi Myrtha R. , Rezza Irma G. , Gimenez María S. , Anzulovich Ana C. 
Published: March 2009

AbstractAnimals can adapt their behavior to predictable temporal fluctuations in the environment through both, memory‐and‐learning processes and an endogenous time‐keeping mechanism. Hippocampus plays a key role in memory and learning and is especially susceptible to oxidative stress. In compensation, antioxidant enzymes activity, such as Catalase (CAT) and Glutathione peroxidase (GPx), has been detected in this brain region. Daily rhythms of antioxidant enzymes activity, as well as of glutathione and lipid peroxides levels, have been described in brain. Here, we investigate day/night variations in lipoperoxidation, CAT, and GPx expression and activity, as well as the temporal fluctuations of two key components of the endogenous clock, BMAL1 and PER1, in the rat hippocampus and evaluate to which extent vitamin A deficiency may affect their amplitude or phase. Holtzman male rats from control, vitamin A‐deficient, and vitamin A‐refed groups were sacrificed throughout a 24‐h period. Daily levels of clock proteins, lipoperoxidation, CAT and GPx mRNA, protein, and activity, were determined in the rat hippocampus obtained every 4 or 5 h. Gene expression of RARα and RXRβ was also quantified in the hippocampus of the three groups of rats. Our results show significant daily variations of BMAL1 and PER1 protein expression. Rhythmic lipoperoxidation, CAT, and GPx, expression and activity, were also observed in the rat hippocampus. Vitamin A deficiency reduced RXRβ mRNA level, as well as the amplitude of BMAL1 and PER1 daily oscillation, phase‐shifted the daily peak of lipoperoxidation, and had a differential effect on the oscillating CAT and GPx mRNA, protein, and activity. Learning how vitamin A deficiency affects the circadian gene expression in the hippocampus may have an impact on the neurobiology, nutritional and chronobiology fields, emphasizing for the first time the importance of nutritional factors, such as dietary micronutrients, in the regulation of circadian parameters in this brain memory‐and‐learning‐related region. © 2009 Wiley‐Liss, Inc.
Hippocampal volume and asymmetry in mild cognitive impairment and Alzheimer's disease: Meta‐analyses of MRI studies
Authors: Shi Feng , Liu Bing , Zhou Yuan , Yu Chunshui , Jiang Tianzi 
Published: March 2009

AbstractNumerous studies have reported a smaller hippocampal volume in Alzheimer's disease (AD) patients than in aging controls. However, in mild cognitive impairment (MCI), the results are inconsistent. Moreover, the left‐right asymmetry of the hippocampus receives less research attention. In this article, meta‐analyses are designed to determine the extent of hippocampal atrophy in MCI and AD, and to evaluate the asymmetry pattern of the hippocampal volume in control, MCI, and AD groups. From 14 studies including 365 MCI patients and 382 controls, significant atrophy is found in both the left [Effect size (ES), 0.92; 95% confidence interval (CI), 0.72–1.11] and right (ES, 0.78; 95% CI, 0.57–0.98) hippocampus, which is lower than that in AD (ES, 1.60, 95% CI, 1.37–1.84, in left; ES, 1.52, 95% CI, 1.31–1.72, in right). Comparing with aging controls, the average volume reduction weighted by sample size is 12.9% and 11.1% in left and right hippocampus in MCI, and 24.2% and 23.1% in left and right hippocampus in AD, respectively. The findings show a bilateral hippocampal volume loss in MCI and the extent of atrophy is less than that in AD. By comparing the left and right hippocampal volume, a consistent left‐less‐than‐right asymmetry pattern is found, but with different extents in control (ES, 0.39), MCI (ES, 0.56), and AD (ES, 0.30) group. © 2009 Wiley‐Liss, Inc.
Effects of neonatal stress on markers of synaptic plasticity in the hippocampus: Implications for spatial memory
Authors: Aisa Bárbara , Elizalde Natalia , Tordera Rosa , Lasheras Berta , Del Río Joaquín , Ramírez Maria J. 
Published: March 2009

AbstractEarly stressful adverse situations may increase the vulnerability to cognitive deficits and psychiatric disorders, such as depression. Maternal separation (MS) has been used as an animal model to study changes in neurochemistry and behavior associated with exposure to early‐life stress. This study investigated the effects of neonatal stress (MS) on the expression of synaptic plasticity markers in the hippocampus and a purported relationship to cognitive processes. Spatial learning (Morris water maze) significantly increased the expression of total levels of the neural cell adhesion molecule (NCAM), as well as its three major isoforms (NCAM‐120, ‐140, and ‐180) both in the control and MS groups. Interestingly, these increases in NCAM expression after learning were lower in MS animals when compared with control rats. MS induced a significant decrease in total levels of NCAM, and specifically, in the NCAM‐140 isoform expression. In the hippocampus of MS rats there was a significant decrease in brain‐derived neurotrophic factor and synaptophysin mRNA densities. Cell proliferation, measured as BrdU‐positive cells, was also decreased in the dentate gyrus of MS rats. Altogether these results suggest that MS can alter normal brain development, providing a potential mechanism by which early environmental stressors may influence vulnerability to show cognitive impairments later in life. © 2009 Wiley‐Liss, Inc.