bluuebunny/crossref_metadata_2025 huggingface dataset:
Structures and Physical Properties of Highly Conducting Single‐Component Molecular Conductors Containing Se Atoms
Authors: Fujiwara Emiko , Zhou Biao , Kobayashi Akiko , Kobayashi Hayao , Fujishiro Yuichi , Nishibori Eiji , Sakata Makoto , Ishibashi Shoji , Terakura Kiyoyuki
Published: March 2009

Single‐component molecular conductors [M(tmstfdt)2] (M = Ni, Au; tmstfdt = trimethylenediselenadithiafulvalenedithiolate) substituted with Se atoms are prepared and found to be isostructural with [M(tmdt)2] (M = Ni, Au; tmdt = trimethylenetetrathiafulvalenedithiolate). Measurements of the electrical conductivity and magnetic susceptibility of [Ni(tmstfdt)2] show that it has essentially metallic properties down to low temperatures. The resistivity measurements of [Au(tmstfdt)2] suggest it undergoes a metal‐insulator phase transition at around 100 K. Magnetic susceptibility and ESR measurements of [Au(tmstfdt)2] indicate that it undergoes a magnetic transition at around 5 K, which is much lower than theantiferromagnetic (AF) phase‐transition temperature of [Au(tmdt)2] (110 K). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Platinum Anticancer Coordination Compounds: Study of DNA Binding Inspires New Drug Design (Eur. J. Inorg. Chem. 10/2009)
Authors: Reedijk Jan
Published: March 2009

The cover picture shows an impression of the binding of dinuclear platinum compounds to double‐stranded DNA. Details are presented in the Microreview by J. Reedijk on p. 1303 ff.
Concave 1,10‐Phenanthrolines as Ligands for Cyclopropanations – Towards a Deeper Understanding of the Stereoselectivity
Authors: Eggers Friederike , Lüning Ulrich
Published: March 2009

Four new mono‐ and bimacrocyclic 1,10‐phenanthrolines – 3b and 4a–c – containing aryl bridgeheads have been synthesised. The etherification of the aryl bridgeheads was accomplished by Williamson or Mitsunobu reactions. A key step in the synthesis of the macrocyclic phenanthrolines 3 and 4 is the Suzuki coupling of 2,9‐diiodo‐1,10‐phenanthroline (12) with the appropriately substituted boronic acids 17 and 20. Ring‐closing metathesis and hydrogenation completed the synthesis. The resulting macrocyclic 1,10‐phenanthrolines 3b and 4a–c were tested as ligands in a copper(I)‐catalysed stereoselective cyclopropanation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Lipophilic Thioglycosides for the Solution‐Phase Synthesis of Oligosaccharides Using Biphasic Liquid‐Liquid Separation
Authors: Encinas Lourdes , Chiara Jose Luis
Published: March 2009

A simple “heavy” lipophilic tag readily prepared from inexpensive gallic acid can greatly simplify the purification steps in oligosaccharide synthesis through liquid‐liquid extraction (LLE) using two immiscible organic solvents. By introducing the tag at the anomeric position of the carbohydrate acceptor, this simple LLE purification can be advantageously carried out at each step throughout the synthetic route. We have developed efficient tagging and detagging procedures and have shown that a single tag is sufficient to ensure a high affinity of the tagged molecule for alkane solvents even in the case of highly polar substrates.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
The impact of exchange programs on the integration of the hostgroup into the self‐concept
Authors: Sassenberg Kai , Matschke Christina
Published: March 2009

Two studies analyzed the impact of international exchange programs on students' identity development. More precisely, the authors predict that exchange students integrate the host society (hostgroup) into their self‐concept during an exchange year. Study 1 found a stronger social identification with the hostgroup and higher commitment for former exchange students than for future exchange students. Study 2 replicated the difference between former and future exchange students and found in addition that both former and future exchange students had a stronger identification and commitment in comparison to a control group that did neither take part in nor apply for an exchange program. Moreover, in this study the inclusion of the hostgroup into the self‐concept was assessed via a response time paradigm. The results indicate that former and future exchange students have a stronger association between the self and the hostgroup than the control sample, but no difference between former and future exchange students was found. The results provide evidence for the impact of interest in and actual intensive intergroup contact on students' self‐concept. Copyright © 2009 John Wiley & Sons, Ltd.
Selecting explanations from causal chains: Do statistical principles explain preferences for voluntary causes?
Authors: Hilton Denis J. , McClure John , Sutton Robbie M.
Published: March 2009

We investigate whether people prefer voluntary causes to physical causes in unfolding causal chains and whether statistical (covariation, sufficiency) principles can predict how people select explanations. Experiment 1 shows that while people tend to prefer a proximal (more recent) cause in chains of unfolding physical events, causality is traced through the proximal cause to an underlying distal (less recent) cause when that cause is a human action. Experiment 2 shows that causal preference is more strongly correlated with judgements of sufficiency and conditionalised sufficiency than with covariation or conditionalised covariation. In addition, sufficiency judgements are partial mediators of the effect of type of distal cause (voluntary or physical) on causal preference. The preference for voluntary causes to physical causes corroborates findings from social psychology, cognitive neuroscience and jurisprudence that emphasise the primacy of intentions in causal attribution processes. Copyright © 2009 John Wiley & Sons, Ltd.
Rule transgressions in groups: The conditional nature of newcomers' willingness to confront deviance
Authors: Jetten Jolanda , Hornsey Matthew J. , Spears Russell , Haslam S. Alexander , Cowell Eleanor
Published: March 2009

We provide evidence that, compared to old‐timers, newcomers' intentions to confront deviants are more sensitive to the social context when confronted with rule‐violations. Female rugby players (N = 71) were asked for their disapproval of, and willingness to sanction, ingroup and outgroup members who broke important rules in rugby. We also manipulated the status of the audience and found that newcomers were more likely to confront deviants when the audience was high status, and when there was little risk of alienating other ingroup members. In contrast, old‐timers expressed relatively high intentions to confront deviants regardless of the context. Discussion focuses on the idea that newcomers resiled from confronting deviants when an ingroup rule‐breaker had to be directly confronted, presumably because the perceived costs of doing so exceeded the potential benefits of ingratiating oneself to the high‐status audience. Copyright © 2009 John Wiley & Sons, Ltd.
On the robustness of the group reference effect
Authors: Bennett Mark , Allan Susan , Anderson Jennifer , Asker Nasreen
Published: March 2009

Extending the self‐reference effect to the level of group identities, previous research has shown that participants' encoding of trait adjectives with reference to ingroups facilitates recall relative to a control condition in which judgments are made about adjectives' meanings. We contend that this experimental comparison may have exaggerated the extent of the group reference effect. Two studies are reported that examine this contention. In Study 1 participants encoded adjectives with reference to an ingroup, an outgroup or to its semantic properties. Study 2 was nearly identical but required that adjectives be encoded with reference to an ingroup, the personal self or a specific person other than the self. Notwithstanding the use of more stringent controls, both studies provided evidence for the group reference effect. Copyright © 2009 John Wiley & Sons, Ltd.
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

In 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

Appropriate 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

Agarose 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

The 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

Suspended 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

To 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

The 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

We 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

The 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

This 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

Do 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

Background.

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

Background.

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

Animals 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

Numerous 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

Early 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.
Increased hippocampal neurogenesis in the progressive stage of Alzheimer's disease phenotype in an APP/PS1 double transgenic mouse model
Authors: Yu Yingxin , He Jue , Zhang Yanbo , Luo Huanmin , Zhu Shenghua , Yang Yi , Zhao Tou , Wu Jiang , Huang Yuangui , Kong Jiming , Tan Qingrong , Li Xin‐Min
Published: March 2009

Alzheimer's disease (AD) is a progressive neurodegenerative disease associated with senile β‐amyloid (Aβ) plaques and cognitive decline. Neurogenesis in the adult hippocampus is implicated in regulating learning and memory, and is increased in human postmortem brain of AD patients. However, little is currently known about the changes of hippocampal neurogenesis in the progression of AD. As brain tissues from patients during the progression of AD are generally not available, an amyloid precursor protein (APP)/presenilin1 (PS1) double transgenic mouse model of AD was studied. Bromodeoxyuridine (BrdU) labeling supported by doublecortin staining was used to detect proliferating hippocampal cells in the mice. Compared with age‐matched wild‐type controls, 9‐month‐old transgenic mice with memory impairment and numerous brain Aβ deposits showed increased numbers of proliferating hippocampal cells. However, 3‐month‐old transgenic mice with normal memory and subtle brain Aβ deposits showed normal hippocampal proliferation. Double immunofluorescent labeling with BrdU and either NeuN or glial fibrillary acidic protein was conducted in mice at 10 months (28 days after the last BrdU injection) to determine the differentiation of proliferating cells. The number of hippocampal BrdU‐positive cells and BrdU‐positive cells differentiating into neurons (neurogenesis) in 10‐month‐old mice was greater in transgenic mice compared with age‐matched controls, but the ratio of hippocampal BrdU‐positive cells differentiating into neurons and astroglia was comparable. These results suggest hippocampal neurogenesis may increase during the progression of AD. Targeting this change in neurogenesis and understanding the underlying mechanism could lead to the development of a new treatment to control the progression of AD. © 2009 Wiley‐Liss, Inc.
Long‐term treadmill exposure protects against age‐related neurodegenerative change in the rat hippocampus
Authors: O'Callaghan Rachel M. , Griffin Éadaoin W. , Kelly Áine M.
Published: March 2009

The potential of exercise or environmental enrichment to prevent or reverse age‐related cognitive decline in rats has been widely investigated. The data suggest that the efficacy of these interventions as neuroprotectants may depend upon the duration and nature of the protocols and age of onset. Investigations of the mechanisms underlying these neuroprotective strategies indicate a potential role for the neurotrophin family of proteins, including nerve growth factor (NGF) and brain‐derived neurotrophic factor (BDNF). In this study, we have assessed the effects of 8 months of forced exercise, begun in middle‐age, on the expression of long‐term potentiation (LTP) and on spatial learning in the Morris water maze in aged Wistar rats. We also assessed these measures in a cage control group and in a group of rats exposed to the stationary treadmill for the same duration as the exercised rats. Our data confirm an age‐related decline in expression of LTP and in spatial learning concomitant with decreased expression of NGF and BDNF mRNA in dentate gyrus (DG). The age‐related impairments in both plasticity and growth factor expression were prevented in the long‐term exercised group and, surprisingly, the treadmill control group. Given the extensive handling that the treadmill control group received and their regular exposure to an environment outside the home cage, this group can be considered to have experienced environmentally enriched conditions when compared with the cage control group. Significant correlations were observed between both learning and LTP and the expression of NGF and BDNF mRNA in the dentate gyrus. We conclude that decreased expression of NGF and BDNF in the dentate gyrus of aged rats is associated with impaired LTP and spatial learning. We suggest that the reversal of these age‐related impairments by enrichment and exercise may be linked with prevention of the age‐related decline in expression of these growth factors and, furthermore, that enrichment is as efficacious as exercise in preventing this age‐related decline. © 2009 Wiley‐Liss, Inc.
Decreased neuronal differentiation of newly generated cells underlies reduced hippocampal neurogenesis in chronic temporal lobe epilepsy
Authors: Hattiangady Bharathi , Shetty Ashok K.
Published: March 2009

Hippocampal neurogenesis declines substantially in chronic temporal lobe epilepsy (TLE). However, it is unclear whether this decline is linked to altered production of new cells and/or diminished survival and neuronal fate‐choice decision of newly born cells. We quantified different components of hippocampal neurogenesis in rats exhibiting chronic TLE. Through intraperitoneal administration of 5′‐bromodeoxyuridine (BrdU) for 12 days, we measured numbers of newly born cells in the subgranular zone‐granule cell layer (SGZ‐GCL) at 24 h and 2.5 months post‐BrdU administration. Furthermore, the differentiation of newly added cells into neurons and glia was quantified via dual immunofluorescence for BrdU and various markers of neurons and glia. Addition of new cells to the SGZ‐GCL over 12 days was comparable between the chronically epileptic hippocampus and the age‐matched intact hippocampus. Furthermore, comparison of BrdU+ cells measured at 24 h and 2.5 months post‐BrdU administration revealed similar survival of newly born cells between the two groups. However, only 4–5% of newly born cells (i.e., BrdU+ cells) differentiated into neurons in the chronically epileptic hippocampus, in comparison to 73–80% of such cells exhibiting neuronal differentiation in the intact hippocampus. Moreover, differentiation of newly born cells into S‐100β+ astrocytes or NG2+ oligodendrocyte progenitors increased to ∼79% in the chronically epileptic hippocampus from ∼25% observed in the intact hippocampus. Interestingly, the extent of proliferation of astrocytes and microglia (identified through Ki‐67 and S‐100β and Ki‐67 and OX‐42 dual immunofluorescence) in the SGZ‐GCL was similar between the chronically epileptic hippocampus and the age‐matched intact hippocampus, implying that the proliferation of neural stem/progenitor cells in the SGZ‐GCL of the chronically epileptic hippocampus was not obscured by an increased division of glia. Thus, severely diminished DG neurogenesis in chronic TLE is not associated with either decreased production of new cells or reduced survival of newly born cells in the SGZ‐GCL. Rather, it is linked to a dramatic decline in the neuronal fate‐choice decision of newly generated cells. Overall, the differentiation of newly born cells turns mainly into glia with chronic TLE from predominantly neuronal differentiation seen in control conditions. © 2009 Wiley‐Liss, Inc.
5‐HT1Aand NMDA receptors interact in the rat medial septum and modulate hippocampal‐dependent spatial learning
Authors: Elvander‐Tottie Elin , Eriksson Therese M. , Sandin Johan , Ögren Sven Ove
Published: March 2009

Cholinergic and GABAergic neurons in the medial septum/vertical limb of the diagonal band of Broca (MS/vDB) projecting to the hippocampus, constitute the septohippocampal projection, which is important for hippocampal‐dependent learning and memory. There is also evidence for an extrinsic as well as an intrinsic glutamatergic network within the MS/vDB. GABAergic and cholinergic septohippocampal neurons express the serotonergic 5‐HT1Areceptor and most likely also glutamatergic NMDA receptors. The aim of the present study was to examine whether septal 5‐HT1Areceptors are important for hippocampal‐dependent long‐term memory and whether these receptors interact with glutamatergic NMDA receptor transmission in a manner important for hippocampal‐dependent spatial memory. Intraseptal infusion of the 5‐HT1Areceptor agonist (R)‐8‐OH‐DPAT (1 or 4 μg/rat) did not affect spatial learning in the water maze task but impaired emotional memory in the passive avoidance task at the higher dose tested (4 μg/rat). While intraseptal administration of (R)‐8‐OH‐DPAT (4 μg) combined with a subthreshold dose of the NMDA receptor antagonist D‐AP5 (1 μg) only marginally affected spatial acquisition, it produced a profound impairment in spatial memory. In conclusion, septal 5‐HT1Areceptors appears to play a more prominent role in emotional than in spatial memory. Importantly, septal 5‐HT1Aand NMDA receptors appear to interact in a manner, which is particularly critical for the expression or retrieval of hippocampal‐dependent long‐term spatial memory. It is proposed that NMDA receptor hypofunction in the septal area may unmask a negative effect of 5‐HT1Areceptor activation on memory, which may be clinically relevant. © 2009 Wiley‐Liss, Inc.
Histone marks and chromatin remodelers on the regulation of neurogenin1 gene in RA induced neuronal differentiation of P19 cells
Authors: Wu Meng , Zhang Ye , Wu Ning‐hua , Shen Yu‐fei
Published: March 2009

Neurogenin1 is an important bHLH protein that plays crucial role in neurogenesis. We first show that the expression of ngn1 increases drastically in RA induced neuronal differentiation. During which, a three successive stages of the epigenetic changes surrounding the ngn1 gene are found correlated with a repression to activation of the gene in P19 cells. Recruiting of a repressive histone code H3K27me3 on the ngn1 gene is the dominant change in first repression stage, which is followed by the binding of the active codes of H3K9ac, H3K14ac, and the H3K4me3 in the second and third stages of RA treatment. Additionally, BRM but not BRG1 is specifically recruited to ngn1 gene at the third stage and is positively involved in the RA induced ngn1 expression. We propose that histone modifiers and chromatin remodelers are pivotal in the activation of the ngn1 gene in RA induced differentiation of P19 cells. J. Cell. Biochem. 107: 264–271, 2009. © 2009 Wiley‐Liss, Inc.
The SUMO‐E3 ligase PIAS3 targets pyruvate kinase M2
Authors: Spoden Gilles A. , Morandell Dieter , Ehehalt Daniela , Fiedler Marc , Jansen‐Dürr Pidder , Hermann Martin , Zwerschke Werner
Published: March 2009

Pyruvate kinase M2 (M2‐PK) controls the rate‐limiting step at the end of the glycolytic pathway in normal proliferating and tumor cells. Other functions of M2‐PK in addition to its role in glycolysis are little understood. The aim of this study was to identify new cellular interaction partners of M2‐PK in order to discover novel links between M2‐PK and cellular functions. Here we show that the SUMO‐E3 ligase protein PIAS3 (inhibitor of activated STAT3) physically interacts with M2‐PK and its isoenzyme M1‐PK. Moreover, we demonstrate that endogenous SUMO‐1‐M2‐PK conjugates exist in mammalian cells. Furthermore, we show that transient expression of PIAS3 but not the RING domain mutant PIAS3 (C299S, H301A) is consistent with nuclear localization of M2‐PK and PIAS3 and M2‐PK partially co‐localize in the nucleus of these cells. This study suggests a link between PIAS3 and nuclear pyruvate kinase. J. Cell. Biochem. 107: 293–302, 2009. © 2009 Wiley‐Liss, Inc.
Control mechanisms of differential translation of Hsp90 isoforms in 9L rat gliosarcoma cells
Authors: Lo Chih‐Wei , Chang Yuo‐Sheng , Chao Chih‐Chung , Chang Margaret Dah‐Tsyr , Chang Kun‐Che , Lai Yiu‐Kay
Published: March 2009

Although the differential expression of heat shcok proteins, Hsp90α and Hsp90β was extensively studied in many kinds of cells, the post‐transcriptional regulation of Hsp90 isoforms remains unclear. In control and GA‐treated rat gliosarcoma cells, it has been reported that the translational efficiency of hsp90α is higher than hsp90β. In this study, we present evidences identifying the roles for leaky scanning and 5′‐UTR sequence in translational regulation of Hsp90β. The result of in vitro transcription and translation (IVTT) experiment showed that hsp90α exhibited higher translation efficiency than hsp90β. Sequence analysis revealed that there is an out‐of‐frame downstream AUG codon in hsp90β gene. However, elimination of the downstream AUG by site‐directly mutagenesis or introducing Kozak context sequence around the initiator AUG of hsp90β open reading frame increased its translational efficiency, which indicated that leaky scanning might be a possible mechanism regulating hsp90β. Furthermore, we also constructed a firefly luciferase reporter system to verify the effect of subsequent translation at the downstream out‐of‐frame AUG codon in 9L and A549 cells. Furthermore, it is believed that 5′‐untranslated region (5′‐UTR) also plays a significant role in translational control. We showed hsp90β 5′‐UTR gives rise to the reduction of the translation efficiency in IVTT experiment. Additionally, the reductive effect of hsp90β 5′‐UTR was further confirmed by luciferase reporter assay using truncated deletion analyses of 5′‐UTR of hsp90β. Our results support the hypothesis that ribosome leaky scanning mechanism and 5′‐UTR sequence acts as negative regulators in hsp90β mRNA. J. Cell. Biochem. 107: 418–427, 2009. © 2009 Wiley‐Liss, Inc.
Daxx inhibits muscle differentiation by repressing E2A‐mediated transcription
Authors: Gupta Amitabh , Hou Rong , Liu Liming , Hiroyasu Shungo , Hadix Jennifer A. , Huggins Gordon S. , Sibinga Nicholas E.S.
Published: March 2009

The basic helix‐loop‐helix (HLH) E2A transcription factors bind to DNA as homodimers or as heterodimers formed with other basic HLH factors, activate gene expression, and promote differentiation of muscle, lymphoid, neuronal, and other cell types. These E2A functions can be inhibited by the Id proteins, HLH factors that sequester E2A in non‐DNA binding dimers. Here we describe the direct interaction of E2A with Daxx, a broadly expressed non‐HLH protein previously associated with apoptosis and transcriptional repression. Daxx inhibits E2A function, but not via an Id‐like mechanism; rather, it recruits histone deacetylase activity to E2A‐dependent promoters. Increased Daxx expression during muscle differentiation inhibits E2A‐dependent expression of key myogenic genes and reduces myotube formation, while decreased Daxx expression promotes myotube formation. These results identify a new mechanism for limiting E2A activity and establish a link between Daxx‐mediated gene regulation and control of cellular differentiation. J. Cell. Biochem. 107: 438–447, 2009. © 2009 Wiley‐Liss, Inc.
OxLDL upregulates caveolin‐1 expression in macrophages: Role for caveolin‐1 in the adhesion of oxLDL‐treated macrophages to endothelium
Authors: Wu Chau‐Chung , Wang Shu‐Huei , Kuan I.‐I. , Tseng Wei‐Kung , Chen Ming‐Fong , Wu Jiahn‐Chun , Chen Yuh‐Lien
Published: March 2009

Caveolin‐1, a principle component of caveolae, is present in several cell types known to play an important role in the development of atherosclerosis. In this study, its distribution and expression were studied in the arterial walls of hypercholesterolemic rabbits and apo‐E‐deficient mice and in oxidized low‐density lipoprotein (oxLDL)‐treated RAW264.7 macrophages. Immunohistochemical studies showed that staining for caveolin‐1 expression was stronger in atherosclerotic lesions in hypercholesterolemic rabbits and apo‐E‐deficient mice compared to normal rabbits and mice and was closely associated with macrophages. OxLDL treatment increased caveolin‐1 protein expression in RAW264.7 macrophages in a time‐ and dose‐dependent manner. The increase in caveolin‐1 expression was dependent on phosphorylation of the mitogen‐activated protein kinases (MAPKs) extracellular signal‐regulated kinase1/2 (ERK1/2), p38, and Jun N‐terminal kinase (JNK) and the transcriptional activation and translocation of nuclear factor‐?B (NF‐κB). OxLDL also induced caveolin‐1 mRNA expression and this effect was not seen in the presence of inhibitors for transcription or de novo protein synthesis. OxLDL increased the adhesion of RAW264.7 macrophages to endothelial cells via an increase in caveolin‐1 expression, and the adhesion was reduced by the use of anti‐caveolin‐1 antibody or caveolin‐1‐specific shRNA. These results show that oxLDL increases caveolin‐1 expression in macrophages through the MAPKs/NF‐κB pathway. The caveolin‐1 levels are closely associated with the adherence of monocytes/macrophages to endothelial cells and their accumulation within the arterial intima after hypercholesterolemia insult, resulting in the progression of atherosclerosis. J. Cell. Biochem. 107: 460–472, 2009. © 2009 Wiley‐Liss, Inc.