bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plain DFT and hybrid HF‐DFT LCAO calculations of SnO2 (110) and (100) bare and hydroxylated surfaces
Authors: Evarestov R. A. , Bandura A. V. , Proskurov E. V. 
Published: May 2006

AbstractThe density functional LCAO calculations using DFT (PBE) and hybrid HF‐DFT (B3LYP) functionals are presented for the electronic and structural properties of bare and hydroxylated low index surfaces of SnO2 crystal. The dissociative and associative water adsorption on (110) and (100) SnO2 surfaces is investigated. The role of geometrical and chemical‐bonding factors in the relative stability of different adsorption structures is discussed. The comparison of plain DFT functionals with the B3LYP hybrid functional shows that, in contrast to former DFT plane‐wave calculations (spontaneous dissociation), an associative adsorption of the water molecules becomes possible not only in the case of the (100) surface but also at the most stable (110) surface. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and optical properties of CuAlTe2
Authors: Korzun B. V. , Fadzeyeva A. A. , Mudryi A. V. , Schorr S. 
Published: May 2006

AbstractBulk crystals of the ternary CuAlTe2 semiconductor with chalcopyrite structure were prepared and their structural and optical properties, including transmission and reflectance, were investigated. It was evaluated that the value of optical gap energy equals 1.65 eV at 293 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Updating interleukin‐6 classic‐ and trans‐signaling
Authors: Scheller Jürgen , Grötzinger Joachim , Rose‐John Stefan 
Published: May 2006

AbstractThe cytokine interleukin‐6 has been identified and cloned among others as B‐cell stimulatory factor, hepatocyte stimulating factor, plasmacytoma growth factor, and interferon beta‐2. Consequently, it emerged, that IL‐6 controls a huge variety of cellular functions, among them induction of the acute phase response in the liver, mediation of inflammation and malignant transformation. In this review, we summarize the so called classical IL‐6 signaling, which is mediated by the complex of IL‐6, the membrane bound IL‐6R and two gp130 molecules, and an alternative pathway called trans‐signaling, which apparently contributes to the development of chronic inflammation and cancer. During trans‐signaling an agonistic soluble IL‐6R is generated, which sensitizes cells lacking the membrane bound IL‐6R. Finally, we discuss specific inhibition of IL‐6‐trans‐signaling processes by a naturally occurring soluble form of gp130, demonstrating that this protein may emerge as an important future therapeutic in clinical applications for chronic inflammation.
Effect of Processing of Sword Beans (Canavalia gladiata) on Physicochemical Properties of Starch
Authors: Ekanayake Sagarika , Nair Baboo M. , Asp Nils‐Georg , Jansz Errol R. 
Published: May 2006

AbstractThe effect of various processing methods on physico‐chemical properties of sword bean starch was studied. Seed grits and flour were cooked with and without soaking, wet‐autoclaved, and roasted. The changes in starch associated with these processing methods were studied by observing changes in granular structure, water solubility index, water absorption index, molecular size distribution and the degree of gelatinization estimated by differential scanning calorimetry. Intact, ungelatinized starch granules of raw and dry‐heat treated samples were observed under the light microscope. The starch granules were elliptical in shape and had an average length and breadth of 37–40 μm and 27 μm, respectively. Wet‐processed samples had the lowest water solubility, higher water absorption and lower gelatinization enthalpies than the raw bean flour, whereas the dry heat‐treated samples showed higher water solubility and higher gelatinization enthalpies. The starch molecular size distribution pattern showed a higher amount of high molecular size carbohydrates in dry heat‐treated samples and a large fraction of intermediate molecular size carbohydrates in the wet‐processed samples. The low molecular size carbohydrate content was low in wet‐processed samples where processing was done with excess water.
Hydrolysis of Maltoheptaose in Flow through Silicon Wafer Microreactors Containing Immobilised α‐Amylase and Glycoamylase
Authors: Melander Claes , Tüting Wiebke , Bengtsson Martin , Laurell Thomas , Mischnick Petra , Gorton Lo 
Published: May 2006

AbstractIn this study a silicon micro immobilised enzyme reactor (μIMER) has been applied for hydrolysis of maltoheptaose as a model maltodextrin and starch using immobilised μ‐amylase (from Aspergillus oryzae) and glycoamylase (from Aspergillus niger). The influence of several parameters was investigated such as immobilisation chemistry, buffer constituents, pH, temperature, flow rate and substrate concentration. The conversion efficiency profile of the substrate was measured and the long‐term stability of the reactor was tested. For separation and detection of the formed hydrolysis products, high‐performance anion‐exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) was used. The results show that the μIMERs can also be used for hydrolysis of starch and also additionally be connected directly on‐line with, e.g., liquid chromatography, making it possible to perform on‐line characterisation and analysis of starch hydrolysis products.
A new strategy for prenatal diagnosis of homozygous α0‐thalassemia
Authors: Leung K. Y. , Liao C. , Li Q. M. , Ma S. Y. , Tang M. H. Y. , Lee C. P. , Chan V. , Lam Y. H. 
Published: May 2006

AbstractObjectivesWe have shown previously that ultrasound examination performed by one experienced operator can be useful to exclude homozygous α0‐thalassemia in a tertiary referral center. This study aimed to determine whether the technique was still applicable when performed by several operators and in different centers.MethodsAt the Maternal and Neonatal Hospital of Guangzhou (MNH) and Tsan Yuk Hospital of Hong Kong (TYH), women at risk of homozygous α0‐thalassemia were given the option of a non‐invasive approach (using serial ultrasound examinations at 12–15, 16–20 and 25–30 weeks' gestation) to exclude an affected pregnancy. The fetal cardiothoracic ratio (CTR) was measured at each of these examinations and the placental thickness was measured at 12–15 weeks' gestation. The operators of MNH received training on the ultrasound examination techniques at TYH and the quality of the subsequent ultrasound examinations was checked regularly. The final diagnosis of homozygous α0‐thalassemia was confirmed using an invasive test.ResultsOf 832 at‐risk pregnancies studied in the two hospitals, 168 (20.2%) were affected. The overall sensitivity and specificity of the non‐invasive approach was 100% and 95.6%, respectively. At MNH, the need for an invasive test was reduced by 80.8%, and all the affected pregnancies were diagnosed before 24 weeks' gestation. The results achieved at MNH were comparable with those at TYH. The at‐risk pregnancies including the affected ones presented at a more advanced gestational age at MNH. At each hospital, one affected pregnancy was missed at the 12‐week scan but this was subsequently detected at the 15–18‐week scan.ConclusionsThis non‐invasive approach to exclude homozygous α0‐thalassemia can be applicable when it is performed by several operators and in different centers. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
Mechanochemical copolymerization of poly(vinyl chloride) with methyl methylacrylate in an open mill machine
Authors: He Peixin , He Benqiao , Xiao Weidong , Zhang Yuhong 
Published: May 2006

AbstractMechanical degradation of poly(vinyl chloride) (PVC) and mechanochemical copolymerization in poly(vinyl chloride)/methyl methylacrylate (PVC/MMA) systems were studied in an open mill machine. The effects of the mastication temperature, mastication time, and additives (oxygen, THF, or hydroquinone) on the mechanical degradation of PVC were investigated. The molecular weight of PVC decreased with increasing mastication time, and the efficiency of the mechanodegradation of PVC was lowered with increasing mastication temperature. The effects of the ratio of PVC to MMA, thin‐passage time, and initiator on mechanochemical copolymerization also were studied. The experimental results indicated that the degree of copolymerization increased with increasing thin‐passage times up to 45 times and then remained constant. There was a maximum degree of copolymerization at a ratio of 0.22 g/mL (PVC/MMA), and the efficiency of copolymerization always decreased with increasing time. The maximum degree and efficiency of copolymerization were 5.8 and 89%, respectively. The poly(vinyl chloride‐co‐methyl methylacrylate) copolymer can further improve the interfacial adhesion of PVC and PMMA. Thus it improves the mechanical properties of the PVC/CPE blend more effectively than pure PMMA. J. VINYL. ADDIT. TECHNOL. 12:42–48, 2006. © 2006 Society of Plastics Engineers.
Performance of tocopherols as antioxidants in ABS
Authors: Suffield Rachel M. , Dillman Steven H. , Haworth James E. 
Published: May 2006

AbstractMixed tocopherols, γ‐tocopherol, and δ‐tocopherol were evaluated for antioxidant performance in acrylonitrile–butadiene–styrene by using oxidative induction time as the response. Three commonly used phenolic antioxidants and vitamin E (α‐tocopherol) were used as controls. Mixed tocopherols were found to have a greater antioxidant effect than the hindered phenolic antioxidants or vitamin E in acrylonitrile–butadiene–styrene. γ‐tocopherol was found to be primarily responsible for the improved performance of mixed tocopherols. J. VINYL. ADDIT. TECHNOL. 12:66–72, 2006. © 2006 Society of Plastics Engineers
Antioxidant performance of mixed tocopherols in styrenic block copolymers
Authors: Suffield Rachel M. , Kiesser Jordan E. , Dillman Steven H. 
Published: May 2006

AbstractMixed tocopherols (MT) containing a predominance of γ‐tocopherol were evaluated for antioxidant (AO) performance in polybutadiene‐ and polyisoprene‐based styrenic block copolymers (SBS and SIS, respectively) by using oxidative induction time as a measure of AO performance. A conventional hindered phenolic AO and α‐tocopherol (vitamin E) were evaluated in comparison. MT exhibited significantly higher performance than the controls in both SIS and SBS polymers. J. VINYL ADDIT. TECHNOL., 12:73–77, 2006. © 2006 Society of Plastics Engineers
On‐demand public‐key management for mobile ad hoc networks
Authors: Li Ruidong , Li Jie , Liu Peng , Chen Hsiao‐Hwa 
Published: May 2006

AbstractA mobile ad hoc network (MANET) is the cooperative engagement of a collection of wireless mobile nodes without the aid of any established infrastructure or centralized administration. The conventional security solutions to provide key management through accessing trusted authorities or centralized servers are infeasible for this new environment since mobile ad hoc networks are characterized by the absence of any infrastructure, frequent mobility, and wireless links. In this paper, we propose an on‐demand, fully localized, and hop‐by‐hop public key management scheme for MANETs. It can be performed by generating public/private key pairs by nodes themselves, issuing certificates to neighboring nodes, holding these certificates in their certificate repositories, and providing authentication service adaptive quickly to the dynamic topology of the network without relying on any servers. Also, our scheme can be performed successfully as long as there is a physical communication line between two nodes, and it is accustomed well to the on‐demand routing for MANETs. Copyright © 2006 John Wiley & Sons, Ltd.
A new approach for random key pre‐distribution in large‐scale wireless sensor networks
Authors: Ren Kui , Zeng Kai , Lou Wenjing 
Published: May 2006

AbstractIn a wireless sensor network (WSN), pre‐distribution of secret keys is possibly the most practical approach to protect network communications. To meet the stringent resource constraints of the sensor nodes, key pre‐distribution schemes should be highly efficient, require as little storage space as possible, and at the same time, maintain a strong security strength, that is, high resilience against node capture. In this paper, a new approach for random key pre‐distribution is proposed to achieve both efficiency and security goals. The novelty of this approach lies in that, instead of using a key pool consisting of random keys, a key generation technique is carefully designed such that a large number of random keys can be represented by a small number of key‐generation keys. Then, instead of storing a big number of random keys, each sensor node stores a small number of key‐generation keys while computing the shared secret keys during the bootstrapping phase on the fly using the computationally efficient hash function. The proposed scheme outperforms the previous random key pre‐distribution schemes in that it reduces the storage requirement significantly while holding the comparable security strength, as shown by our thorough analysis and simulation. Copyright © 2006 John Wiley & Sons, Ltd.
Cooperation enforcement schemes for MANETs: a survey
Authors: Marias G. F. , Georgiadis P. , Flitzanis D. , Mandalas K. 
Published: May 2006

AbstractThe employment of adequate trust methods in mobile ad hoc networks (MANET) has been receiving increasing attention during the last few years, and several trust and security establishment solutions that rely on cryptographic and hashing schemes have been proposed. These schemes, although effective, produce significant processing and communication overheads and consume energy, and, hence, they do not take into account the idiosyncrasies of a MANET. More recently, cooperation enforcement methods have been proposed for trust establishment in MANET. These schemes, classified as reputation‐based and credit‐based, are considered suitable for ad hoc networks, where key or certificate distribution centers are absent or ephemerally present, and for networks that consist of devices with limited processing, battery, and memory resources. Cooperation enforcement methods do not provide strong authentication of entities. Instead, they contribute to the identification of the trustworthiness of peers and to the enforcement cooperation using mutual incentives. This paper surveys the most important cooperation enforcement methods that have been introduced, providing a comprehensive comparison between the different proposed schemes. Copyright © 2006 John Wiley & Sons, Ltd.
A location‐based naming mechanism for securing sensor networks
Authors: Zhou Yun , Fang Yuguang 
Published: May 2006

AbstractConventional sensor networks name every node with an identifier from a one dimension name space that has no meaning but identification function. However, it is much useful to let every node identifier carry more characteristics of the node itself. This paper introduces the naming problem for sensor networks in the literature for the first time, and proposes a location‐based naming mechanism (LBN) for sensor networks, in which location information is embedded into node identifier and acts as an inherent node characteristic to provide authentication service in local access control. When LBN is enforced, the impacts of many attacks to sensor network topology can be limited in a small area. A link layer authentication (LLA) scheme is also proposed to further decrease the impacts of those attacks. Our LBN and LLA can be combined and act as an efficient solution against a wide range of attacks in sensor networks. Copyright © 2006 John Wiley & Sons, Ltd.
Mass spectrometry‐based profiling of phospholipids and sphingolipids in extracts from Saccharomyces cerevisiae
Authors: Guan Xue Li , Wenk Markus R. 
Published: May 2006

AbstractLipids are rapidly moving to centre stage in many fields of biological sciences. Lipidomics, the systems‐level scale analysis of lipids and their interacting factors, is thus an emerging field which holds great promise for drug and biomarker discovery. Here we present a mass spectrometry‐based approach for profiling of polar lipids, in particular phospholipids and sphingolipids, in Saccharomyces cerevisiae. The first step includes semi‐quantitative surveys of lipids in an untargeted fashion, which is particularly powerful for detection of changes that cannot easily be anticipated. This leads to the identification of ions with increased or decreased signal intensities. Comprehensive theoretical calculation of the masses of yeast phospholipid and sphingolipid molecular species, based on fatty acyl and headgroup heterogeneity, is next used to tentatively assign ions of interest. Subsequent targeted analysis using tandem mass spectrometry allows for characterization and quantification of phospholipids and sphingolipids. Given the high degree of conservation in pathways of lipid metabolism between different organisms, it can be expected that this method will lead to the discovery of novel enzymatic activities and modulators of known ones, particularly when used in combination with genetic and chemogenetic libraries and screens. We validated the method using the EUROSCARF library of non‐essential deletion mutants. Mutants of SCS7, a lipid hydroxylase, and SLC1, a putative acyl transferase with unknown substrate specificity, were profiled for their phospholipid and sphingolipid content. The observed changes in lipid profiles are consistent with previous observations and extend our knowledge on in vivo substrate use under permissive growth conditions. Copyright © 2006 John Wiley & Sons, Ltd.
Chrono‐ethologic investigations on the Queensland koala (Phascolarctos cinereus adustus) in captivity
Authors: Richter Cora 
Published: May 2006

AbstractThe chronologic behavior pattern of a separately kept pair of koalas at the Tiergarten Schönbrunn (Vienna Zoo) was investigated with regard to how the patterns are distributed over 24 hr and the “zeitgeber” (from German; synonym “entraining agent”) on which they depend. The data was collected continuously by means of infrared video recording over 3 months, January–March 2003 (2,160 hr/animal). Observations were made using the scan‐sampling method at 1‐min intervals. The total activity and each single behavior are described and analyzed in chrono‐ethograms and activity profiles for the first time in this species. The main activity of both koalas occurs between 1:00 AM and 4:00 AM, a continuous sleeping period occurs between 11:00 AM and 3:00 PM (sometimes until 4:00 PM). They become active 1 hr before darkness and inactive 1 hr before dawn (anticipation). During the day koalas are only awakened and become active due to care measures (feedings/weighing). “Zeitgeber” influencing the koalas' behavior are feeding and weighing as well as the light/dark change. To influence the koalas' endogenous rhythm as little as possible, the keepers' daily routine (time and frequency) has to be modified. Zoo Biol 0:1–12, 2006. © 2006 Wiley‐Liss, Inc.
Assessing personality traits associated with depression: the utility of a tiered model
Authors: PARKER GORDON , MANICAVASAGAR VIJAYA , CRAWFORD JO , TULLY LUCY , GLADSTONE GEMMA 
Published: May 2006

Background. We sought to develop a refined measure of eight personality traits or constructs observed in those who develop depression. We report the psychometric properties of the derived Temperament and Personality (T&P) questionnaire, as well as a pilot study examining its capacity to differentiate over-represented personality traits in those with depression.Method. The factor structure of the T&P measure was examined in a general practice sample of 529 subjects. We imposed a range of factorial solutions to determine how higher-order molar constructs arborized to eight lower-order constructs. Scale scores generated at each derived tier were contrasted for 52 out-patients with major depression and control subjects from the general practice sample to pursue over-represented personality constructs, and to clarify if an optimal number of constructs could be identified.Results. In the factor analysis, some 90% of the items loaded on their a priori construct. The questionnaire showed high internal consistency, test–retest reliability and minimal sensitivity to mood state effects. Analyses rejected the hypothesis that risk to depression might be generally affected by individuals merely scoring high on all ‘normal’ personality styles, whether higher-order or lower-order traits.Conclusions. Findings suggest that, while identified constructs linked well with the widely accepted theoretical model of personality (the Five Factor Model) at one tier, such a fixed model may be too inflexible. We therefore detail potential advantages to using a multi-tiered model of personality traits in application studies.
Abnormal function of the brain system supporting motivated attention in medicated patients with schizophrenia: an fMRI study
Authors: LIDDLE PETER F. , LAURENS KRISTIN R. , KIEHL KENT A. , NGAN ELTON T. C. 
Published: May 2006

Background. Patients with schizophrenia have an impaired ability to generate activity that is appropriate to current circumstances and goals.Method. We report a study using functional magnetic resonance imaging (fMRI) to examine cerebral activity during a three-tone auditory oddball target detection task in a sample of 28 patients with schizophrenia and 28 healthy controls.Results. The patients exhibited significantly less activation in response to target stimuli relative to baseline in an extensive set of sites in association neocortex, paralimbic cortex, limbic structures and subcortical nuclei, yet demonstrated a normal level of activation in the sensorimotor cortex. Comparison of activity elicited by rare target stimuli with that elicited by equally rare novel stimuli makes it possible to distinguish cerebral activity associated with attention to behaviourally salient stimuli from activity associated with attending to other attention-capturing stimuli. This comparison revealed that the patients with schizophrenia also exhibited a deficit in activation of basal forebrain areas that mediate motivation during the processing of behaviourally salient stimuli, including the amygdala, ventral striatum, orbital frontal cortex and rostral anterior cingulate cortex.Conclusion. Patients with schizophrenia have a deficit in function of the brain system concerned with mediating motivation, in addition to a more general deficit in the cerebral response to attention-captivating stimuli.
Brain reserve and cognitive decline: a non-parametric systematic review
Authors: VALENZUELA MICHAEL J. , SACHDEV PERMINDER 
Published: May 2006

Background. A previous companion paper to this report (Valenzuela & Sachdev, Psychological Medicine 2006, 36, 441–454) suggests a link between behavioural brain reserve and incident dementia; however, the issues of covariate control and ascertainment bias were not directly addressed. Our aim was to quantitatively review an independent set of longitudinal studies of cognitive change in order to clarify these factors.Method. Cohort studies of the effects of education, occupation, and mental activities on cognitive decline were of interest. Abstracts were identified in MEDLINE (1966–September 2004), CURRENT CONTENTS (to September 2004), PsychINFO (1984–September 2004), Cochrane Library Databases and reference lists from relevant articles. Eighteen studies met inclusion criteria. Key information was extracted by both reviewers onto a standard template with a high level of agreement. Cognitive decline studies were integrated using a non-parametric method after converting outcome data onto a common effect size metric.Results. Higher behavioural brain reserve was related to decreased longitudinal cognitive decline after control for covariates in source studies (ϕ=1·70, p<0·001). This effect was robust to correction for both multiple predictors and multiple outcome measures and was the result of integrating data derived from more than 47000 individuals.Conclusions. This study affirms that the link between behavioural brain reserve and incident dementia is most likely due to fundamentally different cognitive trajectories rather than confound factors.