bluuebunny/crossref_metadata_2025 huggingface dataset:
Behavior of mixtures of nonionic polyoxide‐based surfactants and their application in the destabilization of oil emulsions
Authors: Mansur Claudia R. E. , Lechuga Fernanda C. , Mauro Aparecida C. , González Gaspar , Lucas Elizabete F.
Published: August 2007

During the petroleum dehydration process, it is necessary to use chemical demulsifiers to break the water–oil emulsions that are formed during oil extraction. The majority of the products used are formulations containing nonionic surfactants based on poly(ethylene oxide–propylene oxide) (PEO–PPO) block copolymers with different ethylene oxide/propylene oxide molar ratios. In this work, PEO–PPO block copolymers of different structures were used. The physical–chemical properties of aqueous PEO–PPO solutions and their mixtures were analyzed, along with their effectiveness as water–oil emulsion destabilizing agents. The results showed that all the PEO–PPO copolymers could reduce the interfacial tension between water and oil. Nevertheless, the most efficient water–oil emulsion demulsification was achieved by the PEO–PPO branched copolymer, whose structure presented hydrophilic segments [poly(ethylene oxide) and OH] side by side at the free end of the molecule. This copolymer also exhibited the highest water solubility. Such behavior could be attributed to its structure, which promoted better interaction with the water droplets dispersed in the water–oil emulsion. The performance of the surfactant mixtures appeared to be related to their capacity to reduce the water–oil interfacial tension. The addition of a surfactant at a concentration of roughly 30% without demulsifying action does not compromise the action of a well‐performing surfactant. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Enhancing the electroluminescence properties of novel blue light emitting polymer and MEH‐PPV based white light emitting polymer devices by processing condition optimization
Authors: Lee Rong‐Ho , Hsu Hsin‐Fang
Published: August 2007

A series of triarylaminooxadiazole‐containing tetraphenylsilane light emitting polymer (PTOA) and poly(2‐methoxy, 5‐(2′‐ethyl‐hexyloxy)‐p‐phenylene‐vinylene) (MEH‐PPV) based white light emitting polymer devices (PLEDs) were fabricated to study blue and orange–red emitter composition and light emitting layer processing effects on white emission electroluminescence properties. Color purity, current turn‐on voltage, brightness, and current efficiency were strongly determined by MEH‐PPV content and the thin film processing condition. The intensity of PTOA blue emission was equal to that of MEH‐PPV orange–red emission when the device was fabricated by a polymer composite film containing 10 wt % of MEH‐PPV. Color purity [Commission Internationale de L'Eclairage (CIEx,y) coordinates (0.26,0.33)] was nearly white emission under applied 8 V. The brightness and current efficiency of PTOA‐MEH‐PPV composite film based devices increased as MEH‐PPV content increased. Furthermore, white emission blue shifted with increasing spin‐rate of thin film coating and applied voltage. Low turn‐on voltage, high current density, and high brightness were obtained for the device fabricating with light emitting layer coating with high spin‐rate. Moreover, low current efficiency was obtained for the PLED with a thinner light‐emitting layer. A white emission CIE (0.28,0.34) was obtained for PTOA‐MEH‐PPV based white PLED. White PLED brightness and efficiency can be as high as 700 cd/m2 and 0.78 cd/A, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Ultrahigh molecular weight polyethylene/polypropylene/organo‐montmorillonite nanocomposites: Phase morphology, rheological, and mechanical properties
Authors: Gai Jinggang , Li Huilin
Published: August 2007

Phase morphology, rheological, and mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE)/PP/organo‐montmorillonite nanocomposites were investigated in this work. The results of TEM and XRD indicated that the organo‐montmorillonite PMM prepared with the complex intercalator [2‐methacryloyloxyethyldodecyldimethylammonium bromide/poly(ethylene glycol)] were exfoliated and dispersed into UHMWPE matrix, and the synergistic effect of the complex intercalator on the exfoliation and intercalation for montmorillonite occurred. Besides, the presence of PMM in UHMWPE matrix was found able to lead to a significant reduction of melt viscosity and enhancement in tensile strength and elongation at break of UHMWPE, except that izod‐notched impact strength was without much obvious change. The dispersed PMM particles exhibited a comparatively large two‐dimensional aspect ratio (Lclay/dclay = 35.5), which played an important role in determining the enhancement of mechanical properties of UHMWPE nanocomposites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Two new types of copolymer membranes controlling clonidine zero‐order release
Authors: Zhan Xiaoping , Chen Sijing , Tang Guochun , Mao Zhenmin
Published: August 2007

Two new types of membranes were synthesized by UV curing in our laboratory. The first type of membrane was made of three monomers: 2‐hydroxy‐3‐phenoxypropylacrylate(A), 4‐hydroxybutyl acrylate(B), and 2‐methyl‐2‐nitropropyl methacrylate(C1). The second type of membrane was made of the same monomers A and B, and 2‐butoxyethyl methacrylate(C2). Permeation properties of clonidine releasing through two new types of copolymer membranes were studied. The effects of the ratios of monomers, the thicknesses of membranes, and the concentration of clonidine on the permeation rates were studied. It was found that both copolymer membranes could control clonidine zero‐order release. The permeation rates of the first optimized membrane were linearly dependent on the square root of the drug concentration. The permeation rates of the second optimized membrane had no significant difference when the concentration of clonidine varied in the range of 3.0–5.0 mg mL−1. Furthermore, both optimized membranes were characterized by FTIR, DSC, and SEM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Thinking clearly about biofuels: ending the irrelevant ‘net energy’ debate and developing better performance metrics for alternative fuels
Authors: Dale Bruce E.
Published: August 2007

As the world shifts away from a dependency on petroleum resources it is imperative that clear and accurate perceptions of the value of alternative fuel sources are recognized. The silly “net energy” argument revolving around fuel ethanol offers a textbook example of how not to think about alternative fuels. For over 25 years a small but vocal group of critics has argued that ethanol from corn has a negative net energy. This viewpoint has been widely disseminated and is a major perceived drawback to ethanol. Net energy analysis is simple and has great intuitive appeal. It is also dead wrong and dangerously misleading. If we are to make wise decisions as we embark on this brave new world of alternative fuels, we will need to carefully choose our metrics of comparison. Two complementary metrics suggest themselves. First, alternative fuels (e.g. ethanol) can be rated on their ability to displace petroleum; and second, ethanol could be rated on the total greenhouse gases produced per km driven. These are appropriate metrics, though there is still room for more discussion. Useless, misleading and dangerous metrics such as net energy must be eliminated from our discourse. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
Comparative economics of biorefineries based on the biochemical and thermochemical platforms
Authors: Wright Mark M. , Brown Robert C.
Published: August 2007

A variety of biochemical and thermochemical technologies have been proposed for the production of biofuels. Meaningful economic comparisons require that they be evaluated on the same bases in terms of technology maturity, plant capacity, the energy content of the fuel, feedstock costs, method of calculating capital charges, and year in which the analysis is assumed. Such an analysis for first‐generation biomass‐to‐biofuels plants reveals that capital costs will be comparable for advanced biochemical and thermochemical biorefineries, costing four to five times as much as comparably sized grain ethanol plants. The cost of advanced biofuels, however, will be similar to that of grain ethanol as corn prices exceed $3.00 per bushel. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
Epigenetic “bivalently marked” process of cancer stem cell‐driven tumorigenesis
Authors: Balch Curt , Nephew Kenneth P. , Huang Tim H.‐M. , Bapat Sharmila A.
Published: August 2007

Silencing of tumor suppressor genes (TSGs), by DNA methylation, is well known in adult cancers. However, based on the “stem cell” theory of tumorigenesis, the early epigenetic events arising in malignant precursors remain unknown. A recent report1 demonstrates that, while pluripotent embryonic stem cells lack DNA methylation and possess a “bivalent” pattern of activating and repressive histone marks in numerous TSGs, analogous multipotent malignant cells derived from germ cell tumors (embryonic carcinoma cells) gain additional silencing modifications to those same genes. These results suggest a possible mechanism by which aberrant differentiation, mediated by histone and DNA methylation, instigates tumor progression. BioEssays 29:842–845, 2007. © 2007 Wiley Periodicals, Inc.
Breaking the silence: three bHLH proteins direct cell‐fate decisions during stomatal development
Authors: Pillitteri Lynn Jo , Torii Keiko U.
Published: August 2007

Stomata are microscopic pores on the surface of land plants used for gas and water vapor exchange. A pair of highly specialized guard cells surround the pore and adjust pore size. Studies in Arabidopsis have revealed that cell–cell communication is essential to coordinate the asymmetric cell divisions required for proper stomatal patterning. Initial research in this area identified signaling molecules that negatively regulate stomatal differentiation. However, genes promoting cell‐fate transition leading to mature guard cells remained elusive. Now, three closely related basic helix–loop–helix (bHLH) proteins, SPEECHLESS, MUTE and FAMA have been identified as positive regulators that direct three consecutive cell‐fate decisions during stomatal development. The identification of these genes opens a new direction to investigate the evolution of stomatal development and the conserved functions of bHLH proteins in cell type differentiation adopted by plants and animals. BioEssays 29:861–870, 2007. © 2007 Wiley Periodicals, Inc.
Replacing animal experiments: choices, chances and challenges
Authors: Langley Gill , Evans Tom , Holgate Stephen T. , Jones Anthony
Published: August 2007

Replacing animal procedures with methods such as cells and tissues in vitro, volunteer studies, physicochemical techniques and computer modelling, is driven by legislative, scientific and moral imperatives. Non‐animal approaches are now considered as advanced methods that can overcome many of the limitations of animal experiments. In testing medicines and chemicals, in vitro assays have spared hundreds of thousands of animals. In contrast, academic animal use continues to rise and the concept of replacement seems less well accepted in university research. Even so, some animal procedures have been replaced in neurological, reproductive and dentistry research and progress is being made in fields such as respiratory illnesses, pain and sepsis. Systematic reviews of the transferability of animal data to the clinical setting may encourage a fresh look for novel non‐animal methods and, as mainstream funding becomes available, more advances in replacement are expected. BioEssays 29:918–926, 2007. © 2007 Wiley Periodicals, Inc.
Getting a first clue about SPRED functions
Authors: Bundschu Karin , Walter Ulrich , Schuh Kai
Published: August 2007

Spreds form a new protein family with an N‐terminal Enabled/VASP homology 1 domain (EVH1), a central c‐Kit binding domain (KBD) and a C‐terminal Sprouty‐related domain (SPR). They are able to inhibit the Ras–ERK signalling pathway after various mitogenic stimulations. In mice, Spred proteins are identified as regulators of bone morphogenesis, hematopoietic processes, allergen‐induced airway eosinophilia and hyperresponsiveness. They inhibit cell motility and metastasis and have a high potential as tumor markers and suppressors of carcinogenesis. Moreover, in vertebrates, XtSpreds help together with XtSprouty proteins to coordinate gastrulation and mesoderm specification. Here, we give an overview of this new field and summarize the domain functions, binding partners, expression patterns and the cellular localizations, regulations and functions of Spred proteins and try to give perspectives for future scientific directions. BioEssays 29:897–907, 2007. © 2007 Wiley Periodicals, Inc.
Biomedical research funding: when the game gets tough, winners start to play
Authors: Ascoli Giorgio A.
Published: August 2007

Extramural funding provides major support for biomedical research in academia, and National Institutes of Health (NIH) grants often constitute direct evaluation criteria for promotions and tenure. Therefore, NIH budget trends influence long‐term scientific strategies and career decisions, as well as the progress of science itself. Our analysis of the last 37 years of NIH awards, however, reveals that the success rate of grant applications submitted for funding is negatively related to the total yearly amount of (inflation‐adjusted) NIH extramural expenditure. Instead, as might be expected, the ratio between available funding and the number of submission directly predicts the probability of winning support in any given year. We purport that the considerable success rate variability can be parsimoniously explained by a proportional but delayed reaction of the number of applications to budget fluctuations. As a counterintuitive consequence, grant proposals conceived during lean periods might stand the best chance of success. BioEssays 29:933–936, 2007. © 2007 Wiley Periodicals, Inc.
Mitochondria and ageing: winning and losing in the numbers game
Authors: Passos João F. , von Zglinicki Thomas , Kirkwood Thomas B.L.
Published: August 2007

Mitochondrial dysfunction has long been considered a key mechanism in the ageing process but surprisingly little attention has been paid to the impact of mitochondrial number or density within cells. Recent reports suggest a positive association between mitochondrial density, energy homeostasis and longevity. However, mitochondrial number also determines the number of sites generating reactive oxygen species (ROS) and we suggest that the links between mitochondrial density and ageing are more complex, potentially acting in both directions. The idea that increased density, especially when combined with mitochondrial dysfunction, might accelerate ageing is supported by a negative correlation between mitochondrial density and maximum longevity in an interspecies comparison in mammals, and by evidence for an intimate interconnection between cellular ROS levels, mitochondrial density and cellular ageing. Recent data suggest that retrograde response, which activates mitochondrial biogenesis, accompanies cellular ageing processes. We hypothesise that increased mitochondrial biogenesis, and possibly also impaired degradation and segregation of mitochondria, if occurring as adaptation to pre‐existing mitochondrial dysfunction, might aggravate ROS production and thus actively contribute to ageing. BioEssays 29:908–917, 2007. © 2007 Wiley Periodicals, Inc.
Safer recruitment? Protecting children, improving practice in residential child care
Authors: Kay Helen , Kendrick Andrew , Stevens Irene , Davidson Jennifer
Published: August 2007

In the wake of a number of high‐profile cases of the abuse of children and young people in residential child care, there have been repeated calls for the improvement of recruitment and selection of residential child care staff. This paper describes the findings from a survey, undertaken in 2005, of operational and human resource managers who have responsibility for the recruitment and selection of residential child care staff in the voluntary and statutory sectors in Scotland. This research was commissioned by the Scottish Executive to identify which elements of safer recruitment procedures had been implemented following the countrywide launch of a Toolkit for Safer Recruitment Practice in 2001. Research findings show that although local authorities were more likely than voluntary organisations to have gone some way toward implementing safer recruitment procedures, the recruitment process lacked rigour and commitment to safer procedures in some organisations. The article discusses the current barriers to the introduction of safer recruitment methods and proposes some possible solutions for the future. Copyright © 2007 John Wiley & Sons, Ltd.
Dealing with a problem that doesn't exist? Professional responses to female perpetrated child sexual abuse
Authors: Bunting Lisa
Published: August 2007

Female involvement in sexual offences against children is more common than is generally thought and has serious implications for the long‐term emotional and psychological well‐being of victims. Drawing on findings from: a comprehensive review of the literature; an overview of relevant literature and legislation; and an electronic survey of Multi‐Agency Public Protection Panels; this paper explores the criminal justice response to female sex offending in England, Wales and Northern Ireland.

The literature highlights that the way in which professionals identify and respond to child sexual abuse has been shown to be influenced by the gender of the perpetrator. Equally, whilst similar to male sex offending in terms of the intrusiveness and seriousness of the abuse, some aspects of female sex offending can cause particular problems for professionals. The fact that some sexual abuse can be disguised as childcare can make it difficult for professionals to identify this type of abuse whilst high rates of co‐offending bring additional difficulties in determining the degree of female involvement and assigning responsibility. The survey findings indicate that risk assessment tools for female sex offenders is a key area requiring development and point towards small inconsistencies in the current practice of risk assessing females in the community. The survey also identifies the lack of treatment programmes for this group of offenders as well as drawing attention to the need for national policies and procedures, staff training and the identification of areas of good practice. Increased discussion and debate about how best to work with this group of sex offenders is also required. Copyright © 2007 John Wiley & Sons, Ltd.
Serious business or ‘any other business’? Safeguarding and child protection policy in british rugby league
Authors: Hartill Mike , Prescott Philip
Published: August 2007

State‐funded national governing bodies of sports in the UK now have a mandate to produce, disseminate and embed child protection policies. This warrants an analysis of the impact of such policies, particularly in the context of reaching their target audience and having some early influence on the practice of sports clubs' members in their dealings with children. The authors are undertaking a large research project, which aims to fully evaluate the UK Rugby League's child protection policy. This paper reports findings from an evaluation of the initial implementation of the policy and explores its presentation, delivery and impact within UK rugby league clubs. We argue that the Rugby League should be commended for its initial approach to child protection policy and make specific recommendations to enhance this long‐term project. We conclude that if a broader community of interest concerns itself with the safeguarding of children there is likely to be a greater impact on a social problem of this kind. Sport can have a key role to play in this community because it reaches so many people.
Generation, modeling, and analysis of CCII‐based gyrators using the generalized symbolic framework for linear active circuits
Authors: Saad Ramy A. , Soliman Ahmed M.
Published: August 2007

In this paper, CCII‐based gyrators are synthesized, modeled, and analyzed using the generalized symbolic framework for linear active circuits. The systematic synthesis method using admittance matrix expansion, included in the framework, is applied to generate optimized nullor–mirror descriptions for the gyrator. The resulting CCII‐based circuit representations for the gyrators, obtained from mapping nullor–mirror pairs in the ideal realizations with equivalent second‐generation current conveyors (CCIIs), can be classified into two topologies according to the type of the CCII terminals handling the gyrator input and output signals. In topology I, the gyrator input and output terminals are CCIIsY–Z‐terminals, whereas in topology II, the gyrator input and output terminals are CCIIsX‐terminals. The parasitic components within the synthesized circuits, associated with the actual CCIIs, are modeled and included in their expanded admittance matrices. Exact non‐ideal analysis for two circuits belonging to the two topologies, involving the reduction of their expanded admittance matrices to port admittance matrices, is then carried out to investigate the practical functional performance for these circuits at their ports. The non‐ideal performance analysis based on the CCII actual parasitic elements indicates that, from a practical perspective, the CCII‐based gyrator circuits belonging to topology I are more efficient and suitable for the gyrator applications than those belonging to topology II in terms of bandwidth and operation at high frequencies. SPICE simulations are included to demonstrate the analytical results for the comparison between the practical performances of the two circuit topologies. Copyright © 2007 John Wiley & Sons, Ltd.
Word of mouth communication within online communities: Conceptualizing the online social network
Authors: Brown Jo , Broderick Amanda J. , Lee Nick
Published: August 2007

Word of mouth (WOM) communication is a major part of online consumer interactions, particularly within the environment of online communities. Nevertheless, existing (offline) theory may be inappropriate to describe online WOM and its influence on evaluation and purchase. The authors report the results of a two-stage study aimed at investigating online WOM: a set of in-depth qualitative interviews followed by a social network analysis of a single online community. Combined, the results provide strong evidence that individuals behave as if Web sites themselves are primary “actors” in online social networks and that online communities can act as a social proxy for individual identification. The authors offer a conceptualization of online social networks which takes the Web site into account as an actor, an initial exploration of the concept of a consumer–Web site relationship, and a conceptual model of the online interaction and information evaluation process.
Estimating CLV using aggregated data: The Tuscan Lifestyles case revisited
Authors: Fader Peter S. , Hardie Bruce G.S. , Jerath Kinshuk
Published: August 2007

The Tuscan Lifestyles case (Mason, 2003) offers a simple twist on the standard view of how to value a newly acquired customer, highlighting how standard retention-based approaches to the calculation of expected customer lifetime value (CLV) are not applicable in a noncontractual setting. Using the data presented in the case (a series of annual histograms showing the aggregate distribution of purchases for two different cohorts of customers newly “acquired” by a catalog marketer), it is a simple exercise to compute an estimate of “expected 5 year CLV.” If we wish to arrive at an estimate of CLV that includes the customer's “life” beyond five years or are interested in, say, sorting out the purchasing process (while “alive”) from the attrition process, we need to use a formal model of buying behavior that can be applied on such coarse data.

To tackle this problem, we utilize the Pareto/NBD model developed by Schmittlein, Morrison, and Colombo (1987). However, existing analytical results do not allow us to estimate the model parameters using the data summaries presented in the case. We therefore derive an expression that enables us to do this. The resulting parameter estimates and subsequent calculations offer useful insights that could not have been obtained without the formal model. For instance, we were able to decompose the lifetime value into four factors, namely purchasing while active, dropout, surge in sales in the first year and monetary value of the average purchase. We observed a kind of “triple jeopardy” in that the more valuable cohort proved to be better on the three most critical factors.
Monitoring Notch1 activity in development: Evidence for a feedback regulatory loop
Authors: Del Monte Gonzalo , Grego‐Bessa Joaquím , González‐Rajal Alvaro , Bolós Victoria , De La Pompa José Luis
Published: August 2007

Signaling through Notch receptors, which regulate cell fate decisions and embryonic patterning, requires ligand‐induced receptor cleavage to generate the signaling active Notch intracellular domain (NICD). Here, we show an analysis at specific developmental stages of the distribution of active mouse Notch1. We use an antibody that recognizes N1ICD, and a highly sensitive staining technique. The earliest N1ICD expression was observed in the mesoderm and developing heart, where we detected expression in nascent endocardium, presumptive cardiac valves, and ventricular and atrial endocardium. During segmentation, N1ICD was restricted to the presomitic mesoderm. N1ICD expression was also evident in arterial endothelium, and in kidney and endodermal derivatives such as pancreas and thymus. Ectodermal N1ICD expression was found in central nervous system and sensory placodes. We found that Notch1 transcription and activity was severely reduced in zebrafish and mouse Notch pathway mutants, suggesting that vertebrate Notch1 expression is regulated by a positive feedback loop. Developmental Dynamics 236:2594–2614, 2007. © 2007 Wiley‐Liss, Inc.
Four twist genes in zebrafish, four expression patterns
Authors: Germanguz Igal , Lev Dmitri , Waisman Tal , Kim Cheol‐Hee , Gitelman Inna
Published: August 2007

Twist genes code for regulatory bHLH proteins essential for embryonic development and conserved across the metazoa. There are four genes that constitute the zebrafish twist family: twist1a, twist1b, twist2, orthologs of the mammalian twist1 and twist2 genes; and twist3—a gene from a new clade that does not exist in mammals. Presented here are their embryonic mRNA expression profiles. The study extends the known conservation of twist developmental patterns in tetrapods to the fish, e.g., expression in cephalic neural crest, sclerotome and lateral plate mesoderm. Some other expression domains are unique, like hypochord and dorsal aorta; some, like the notochord, may be ancestral patterns retained from protochordates; and the expression in invaginating/migrating cells may have been retained from the jellyfish. Perhaps this is one of the more ancient functions of twist—conserved from diploblasts to humans—to facilitate cell movement. Developmental Dynamics 236:2615–2626, 2007. © 2007 Wiley‐Liss, Inc.
Expression of zebrafish ROR alpha gene in cerebellar‐like structures
Authors: Katsuyama Yu , Oomiya Yoshihiro , Dekimoto Hideyuki , Motooka Eriko , Takano Ai , Kikkawa Satoshi , Hibi Masahiko , Terashima Toshio
Published: August 2007

Mouse genetic studies have identified several genes involved in cerebellar development. The mouse mutants staggerer and lurcher are functionally deficient for the retinoid‐related orphan receptor alpha (ROR alpha) and glutamate receptor delta2 (Grid2) genes, respectively, and they show similar functional and developmental abnormalities in the cerebellum. Here, we report the cloning and expression pattern of zebrafish ROR alpha orthologues rora1 and rora2, and compare their expression pattern with that of grid2. Expression of rora1 and rora2 is initiated at late gastrula and pharyngula stages, respectively. Both rora1 and rora2 are spatially expressed in the retina and tectum. Expression of rora2 was further observed in the cerebellum, as reported for mammalian ROR alpha. In the adult brain, rora2 and grid2 are coexpressed in brain regions, designated as cerebellar‐like structures. These observations suggest an evolutionarily conserved function of ROR alpha orthologues in the vertebrate brain. Developmental Dynamics 236:2694–2701, 2007. © 2007 Wiley‐Liss, Inc.
Dynamic Sox5 protein expression during cranial ganglia development
Authors: Morales Aixa V. , Perez‐Alcala Siro , Barbas Julio A.
Published: August 2007

Sox5 is a member of the SoxD group of HMG‐box transcription factors that, during the early stages of development, promotes neural crest generation. However, little is known about Sox5 function in neural crest derivatives such as the peripheral sensory nervous system. We have analysed the embryonic expression of Sox5 during chick cranial ganglia development, from the stages of ganglia condensation to those of differentiation. During this period, Sox5 expression is maintained in the crest‐derived satellite glial cells in all the cranial ganglia. In contrast, Sox5 is only transiently expressed in a subpopulation of differentiating neurons of both neural crest and placode origin. This detailed analysis provides a good base to dissect the possible role of Sox5 in neural cell fate determination by future functional approaches. Developmental Dynamics 236:2702–2707, 2007. © 2007 Wiley‐Liss, Inc.
Selective expression of LDLR and VLDLR in myelinating oligodendrocytes
Authors: Zhao Shufang , Hu Xuemei , Park Jinsil , Zhu Ying , Zhu Qiang , Li Hong , Luo Chen , Han Ruifa , Cooper Nigel , Qiu Mengsheng
Published: August 2007

Oligodendrocytes form myelin sheaths around axons in the central nervous system. Although cholesterol is one of the major lipid components in myelin sheath, the source of cholesterol for myelination remains to be defined. In this study, we report that low‐density lipoprotein receptor (LDLR) and very low‐density lipoprotein receptor (VLDLR) are selectively expressed in mature myelinating oligodendrocytes in the postnatal CNS. Both receptors are specifically expressed in differentiated oligodendrocytes in P7 spinal cord, but progressively down‐regulated after P15. In adult animals, only LDLR expression can be detected in a small number of oligodendrocytes throughout the entire spinal cord. In the brain region, LDLR is expressed by the white matter oligodendrocytes of both cerebellum and cerebral cortex, whereas VLDLR has a weak expression in cerebellar oligodendrocytes. Together, our expression studies suggest that cholesterol uptake by LDLR and VLDLR may play an important role in the formation of myelin sheath. Developmental Dynamics 236:2708–2712, 2007. © 2007 Wiley‐Liss, Inc.
Oriented Attachment Growth of Three‐Dimensionally Packed Trigonal Selenium Microspheres into Large‐Area Wire Networks
Authors: Yang Liangbao , Shen Yuhua , Xie Anjian , Liang Jianjun
Published: August 2007

The formation of Se microwire networks by hydrothermal treatment in tungstosilicic acid solution is described. The kinetics of crystallization of the Se assembly is studied as a function of reaction time. During the formation process, single‐crystal Se rods can direct the self‐aggregation of the amorphous nanoparticles derived from a supersaturation precipitation reaction and promote their crystallization and transformation under mild hydrothermal conditions. In this system, the rod‐directed epitaxial aggregation of Se was clearly observed in addition to the traditional Ostwald ripening process.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Incidence and natural course of fatty liver in the general population: The Dionysos study
Authors: Bedogni Giorgio , Miglioli Lucia , Masutti Flora , Castiglione Anna , Crocè Lory Saveria , Tiribelli Claudio , Bellentani Stefano
Published: August 2007

Using the general population of the Dionysos Study, we followed up 144 subjects without fatty liver (FL−) and 336 with fatty liver (FL+) for a median time of 8.5 years. All subjects had suspected liver disease (SLD) defined as altered liver enzymes, high mean corpuscular volume, or low platelet count in the absence of HBV and HCV infection. Ethanol intake was assessed using a food frequency questionnaire, and FL was diagnosed using ultrasonography. The incidence and remission rates of FL were 18.5 and 55.0 per 1,000 person-years. Progression to cirrhosis or HCC was rare in both cohorts (incidence rate: 1.7 versus 1.1 and 0.8 versus 0.4 per 1,000 person-years for FL− versus FL+). Multivariable Poisson regression was performed to identify predictors of FL incidence and remission among sex, age, body mass index, ethanol, and liver enzymes. Every increase of 20 g/day of ethanol intake at baseline was associated with a 17% increase in the rate of incident FL (

P

= 0.019), a 10% decrease in the rate of remitting FL and SLD (

P

= 0.043), a 19% decrease in the rate of remitting FL with persistent SLD (

P

= 0.002), and a 10% increase in mortality rate (

P

= 0.005) in the FL+ cohort.

Conclusion:

In the general population of the Dionysos Study, FL regressed in nearly 1 of every 2 cases and had a substantially benign course. Ethanol intake was the most important risk factor for FL remission and incidence and a predictor of mortality in subjects with FL.
Treatment with amisulpride and olanzapine improve neuropsychological function in schizophrenia
Authors: Mortimer Ann M. , Joyce Eileen , Balasubramaniam Krishnapillai , Choudhary Prasoon C. , Saleem Packeeruther T.
Published: August 2007

Objectives

Although antipsychotic drugs control acute psychotic manifestations of schizophrenia, improving cognitive symptoms is also important for long‐term prognosis.

Methods

Three hundred and seventy‐seven adult patients with acute psychosis were randomised to either amisulpride (200–800 mg/d) or olanzapine (5–20 mg/d) for 6 months. Neuropsychological performance was assessed at inclusion and after 6 months in a subgroup of 26 subjects (11 treated with amisulpride and 15 with olanzapine) using the Auditory Verbal Learning Test (AVLT), the Trail Making Test (TMT) and the Controlled Oral Word Association Test (COWAT).

Results

The improvement in BPRS score was similar in both treatment groups. No significant differences in test performance between groups were observed at inclusion. After 6 months, AVLT scores increased by 8.7 points in the amisulpride group and by 2.3 points in the olanzapine group (p = 0.049). Completion speed in the TMT increased by 17.4 s (amisulpride) and 15.4 s (olanzapine) for Part A and by 39.8 and 48.8 s, respectively for Part B. Performance in the COWAT improved little in both groups.

Conclusions

Both amisulpride and olanzapine produce sustained improvement in certain measures of neuropsychological performance in patients with schizophrenia; a significant improvement in score on the AVLT was observed only with amisulpride. Copyright © 2007 John Wiley & Sons, Ltd.
Variants of chemokine receptor 2 and interleukin 4 receptor, but not interleukin 10 or Fas ligand, increase risk of cervical cancer
Authors: Ivansson Emma L. , Gustavsson Inger M. , Magnusson Jessica J. , Steiner Lori L. , Magnusson Patrik K.E. , Erlich Henry A. , Gyllensten Ulf B.
Published: August 2007

Cervical cancer is caused by persistent infection of oncogenic human papillomavirus (HPV). Most infected women clear the virus without developing cervical lesions and it is likely that immunological host factors affect susceptibility to cervical cancer. The impact of the human leukocyte antigen (HLA) locus on the risk of cervical cancer is established and several other genes involved in immunological pathways have been suggested as biologically plausible candidates. The aim of this study was to examine the potential role of polymorphisms in 4 candidate genes by analysis of 1,306 familial cervical cancer cases and 288 controls. The following genes and polymorphisms were studied: Chemokine receptor 2 (CCR‐2) V64I; Interleukin 4 receptor α (IL‐4R) I75V, S503P and Q576R; Interleukin 10 (IL‐10) −592; and Fas ligand (FasL) −844. The CCR‐2 64I variant was associated with decreased risk of cervical cancer; homozygote carriers of the 64I variant had an odds ratio of 0.31 (0.12–0.77). This association was detected in both carriers and noncarriers of the HLA DQB1*0602 cervical cancer risk allele. The IL‐4R 75V variant was associated with increased risk of cervical tumors, cases homozygote for 75V had an odds ratio of 1.91 (1.27–2.86) with a tendency that the association was stronger in noncarriers of the DQB1*0602 allele. We did not find any association for IL‐10 −592, or FasL −844, previously reported to be associated with cervical cancer in the Dutch and Chinese populations, respectively. © 2007 Wiley‐Liss, Inc.
Identification of a subset of pericytes that respond to combination therapy targeting PDGF and VEGF signaling
Authors: Hasumi Yoko , Kłosowska‐Wardęga Agnieszka , Furuhashi Masao , Östman Arne , Heldin Carl‐Henrik , Hellberg Carina
Published: August 2007

The aim of our study was to further explore the use of anti‐angiogenic therapy targeting the vascular endothelial growth factor receptor (VEGFR) on endothelial cells while simultaneously targeting platelet‐derived growth factor receptors (PDGFRs) on adjacent pericytes. B16 mouse melanoma tumors exogenously expressing PDGF‐BB (B16/PDGF‐BB) display higher pericyte coverage on the vasculature compared to the parental B16 tumors (B16/mock). These models were used to investigate the effects of combination therapy targeting VEGFR and PDGFR signaling on size‐matched tumors. Combination therapy using 25 mg/kg/day of the VEGFR inhibitor PTK787 and 100 mg/kg/day of the PDGFR inhibitor STI571 decreased the tumor growth rate of both tumor types, but the inhibition was only significant in the B16/PDGF‐BB tumors. Combination therapy induced vessel remodeling, primarily by reducing the vessel density in B16/mock tumors, and by reducing the vessel size in B16/PDGF‐BB tumors. When analyzing the effects of combination therapy on tumor vessel pericytes, it was found to primarily reduce the subpopulation of α‐smooth muscle actin and PDGFRβ‐positive pericytes partly detached from the tumor vessels, without affecting the number of pericytes closely attached to the endothelium, which also express desmin. Taken together, these data demonstrate an increased benefit of targeting both VEGFR and PDGFR pathways in B16/PDGF‐BB tumors, and demonstrates that the increased tumor growth inhibition in this model is accompanied by a reduction in a specific subset of pericytes, characterized by being loosely attached to endothelial cells and negative for the pericyte marker desmin. © 2007 Wiley‐Liss, Inc.
Intratumoral homogeneity of MGMT promoter hypermethylation as demonstrated in serial stereotactic specimens from anaplastic astrocytomas and glioblastomas
Authors: Grasbon‐Frodl Eva M. , Kreth Friedrich Wilhelm , Ruiter Michael , Schnell Oliver , Bise Karl , Felsberg Jörg , Reifenberger Guido , Tonn Jörg‐Christian , Kretzschmar Hans A.
Published: August 2007

Hypermethylation of the DNA repair gene O6‐methyl‐guanine DNA methyltransferase (MGMT) has been linked to prolonged survival in glioblastoma patients treated with alkylating agents. It was aimed to analyze prospectively whether the MGMT status of malignant gliomas could be determined from small‐sized stereotactic biopsies (maximum volume: 1 mm3). Special attention was directed towards the intratumoral distribution of the MGMT promoter methylation, the MGMT protein expression and potential correlations between both. Twenty‐five adult patients were included (20 patients with primary World Health Organisation (WHO) Grade III or IV malignant gliomas, 5 patients with secondary malignant gliomas). About 2–4 biopsy specimens per tumor were collected from different sites within the tumor. Promoter methylation of the MGMT gene was assessed by methylation‐specific PCR (MSP) and sodium bisulfite sequencing in each of the collected specimens (overall number of specimens: 69). Both methods were validated for application in small‐sized tissue samples (1 mm3). The MGMT protein expression was analyzed by immunohistochemistry. The overall MGMT promoter methylation rate was 30% in the de novo group and 80% in the tumor progression group. The success rates of MSP and sequencing were 100% and 80%, respectively. Sequence analysis and MSP exhibited 100% concordant findings. No differences in MGMT promoter methylation were detected between the different samples of each individual tumor in 24 of 25 patients. One false negative result was obtained due to the contamination of the biopsy specimen by necrotic tissue. Tissue samples taken from different sites of each individual tumor (13 tumors investigated) exhibited equal or highly similar MGMT protein expression. No correlation between MGMT protein expression and MGMT promoter methylation was observed. The MGMT promoter methylation status of malignant gliomas can be reliably determined from small‐sized stereotactic biopsies. The methylation profile, as defined by MSP and sodium bisulfite sequencing, constitutes a homogeneous marker throughout malignant gliomas. The lack of correlation between MGMT status and MGMT protein expression needs further evaluation. © 2007 Wiley‐Liss, Inc.
Differential osteogenic activity of osteoprogenitor cells on HA and TCP/HA scaffold of tissue engineered bone
Authors: Ng Angela M.H. , Tan K.K. , Phang M.Y. , Aziyati O. , Tan G.H. , Isa M.R. , Aminuddin B.S. , Naseem M. , Fauziah O. , Ruszymah B.H.I.
Published: August 2007

Biomaterial, an essential component of tissue engineering, serves as a scaffold for cell attachment, proliferation, and differentiation; provides the three dimensional (3D) structure and, in some applications, the mechanical strength required for the engineered tissue. Both synthetic and naturally occurring calcium phosphate based biomaterial have been used as bone fillers or bone extenders in orthopedic and reconstructive surgeries. This study aims to evaluate two popular calcium phosphate based biomaterial i.e., hydroxyapatite (HA) and tricalcium phosphate/hydroxyapatite (TCP/HA) granules as scaffold materials in bone tissue engineering. In our strategy for constructing tissue engineered bone, human osteoprogenitor cells derived from periosteum were incorporated with human plasma‐derived fibrin and seeded onto HA or TCP/HA forming 3D tissue constructs and further maintained in osteogenic medium for 4 weeks to induce osteogenic differentiation. Constructs were subsequently implanted intramuscularly in nude mice for 8 weeks after which mice were euthanized and constructs harvested for evaluation. The differential cell response to the biomaterial (HA or TCP/HA) adopted as scaffold was illustrated by the histology of undecalcified constructs and evaluation using SEM and TEM. Both HA and TCP/HA constructs showed evidence of cell proliferation, calcium deposition, and collagen bundle formation albeit lesser in the former. Our findings demonstrated that TCP/HA is superior between the two in early bone formation and hence is the scaffold material of choice in bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Connective‐tissue responses to defined biomaterial surfaces. II. Behavior of rat and mouse fibroblasts cultured on microgrooved substrates
Authors: Grew John C. , Ricci John L. , Alexander Harold
Published: August 2007

Surface microgeometry strongly influences the shapes, orientations, and growth characteristics of cultured cells, but in‐depth, quantitative studies of these effects are lacking. We investigated several contact guidance effects in cells within “dot” colonies of primary fibroblasts and in cultures of a transformed fibroblast cell line, employing titanium‐coated, microgrooved polystyrene surfaces that we designed and produced. The aspect ratios, orientations, densities, and attachment areas of rat tendon fibroblasts (RTF) colony cells, in most cases, varied (p < 0.01) by microgroove dimension. We observed profoundly altered cell morphologies, reduced attachment areas, and reduced cell densities within colonies grown on microgrooved substrates, compared with cells of colonies grown on flat, control surfaces. 3T3 fibroblasts cultured on microgrooved surfaces demonstrated similarly altered morphologies. Fluorescence microscopy revealed that microgrooves alter the distribution and assembly of cytoskeletal and attachment proteins within these cells. These findings are consistent with previous results, and taken together with the results of our in vivo and cell colony growth studies, enable us to propose a unified hypothesis of how microgrooves induce contact guidance. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Connective‐tissue responses to defined biomaterial surfaces. I. Growth of rat fibroblast and bone marrow cell colonies on microgrooved substrates
Authors: Ricci John L. , Grew John C. , Alexander Harold
Published: August 2007

Surface microgeometry plays a role in tissue‐implant surface interactions, but our understanding of its effects is incomplete. Substrate microgrooves strongly influence cells in vitro, as evidenced by contact guidance and cell alignment. We studied “dot” colonies of primary fibroblasts and bone marrow cells that were grown on titanium‐coated, microgrooved polystyrene surfaces that we designed and produced. Rat tendon fibroblast and rat bone marrow colony growth and migration varied (p < 0.01) by microgroove dimension and slightly by cell type. We observed profoundly altered morphologies, reduced growth rates, and directional growth in colonies grown on microgrooved substrates, when compared with colonies grown on flat, control surfaces (p < 0.01). The cells in our colonies grown on microgrooved surfaces were well aligned and elongated in the direction parallel to the grooves and colonies. Our “dot” colony is an easily reproduced, easily measured and artificial explant model of tissue‐implant interactions that better approximates in vivo implant responses than culturing isolated cells on biomaterials. Our results correlate well with in vivo studies of titanium dioxide‐coated polystyrene, titanium, and titanium alloy implants with controlled microgeometries. Microgrooves and other surface features appear to directionally or spatially organize cells and matrix molecules in ways that contribute to improved stabilization and osseointegration of implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
N‐halamine‐based chitosan: Preparation, characterization, and antimicrobial function
Authors: Cao Zhengbing , Sun Yuyu
Published: August 2007

Upon chlorine bleach treatment, amino groups in chitosan were transformed into N‐halamine structures. The transformation was confirmed by UV/VIS, XPS, DSC, and TGA evaluation and iodimetric titration. The N‐halalmine‐based chitosan provided total kill of 108–109 colony forming units (CFU/mL) of E. coli (gram‐negative bacteria) and S. aureus (gram‐positive bacteria) in 10 and 60 min, respectively. SEM observations demonstrated that the chlorinated chitosan effectively prevented the formation of bacterial biofilms. The antimicrobial activity and bio film controlling function were stable for longer than 1 month; when the functions were lost due to extensive use and/or prolonged storage, they could be readily recharged by another bleach treatment. The antimicrobial mechanism was also discussed. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008