bluuebunny/crossref_metadata_2025 huggingface dataset:
Phytosterols and pectin added to a high‐saturated fat diet do not show hypocholesterolemic activity in female guinea pigs
Authors: Brufau Gemma , Canela Miguel Angel , Quílez Joan , Rafecas Magda
Published: February 2008

This paper presents the results of a study whose aim was to test the effects of several doses of pectin and phytosterols on the sterol content in plasma, liver and feces of guinea pigs, when added to a high‐saturated fat diet. The treatments followed a 3×3 factorial design, with three levels of pectin (0, 3.67 and 6.93%) and three levels of phytosterols (0, 1.37 and 2.45%). Seventy‐two female Dunkin Hartley guinea pigs were randomly assigned to the treatment groups (eight animals per group). The duration of the treatment was 4 weeks. No differences were found in plasma cholesterol concentrations, while in liver we saw a reduction in cholesterol concentration after phytosterol feeding. Moreover, we found no pectin effects. Plant sterol concentration increased in plasma and liver after phytosterol ingestion, with the highest concentrations being obtained with the intermediate pectin dose. Our results suggest that a high‐saturated diet may impair the cholesterol‐lowering properties of plant sterols and pectin.
Great globe thistle fruit (Echinops sphaerocephalus L.), a potential new oil crop
Authors: Horn Gert , Kupfer Astrid , Kalbitz Jutta , Gerdelbracht Hans‐Jürgen , Kluge Holger , Eder Klaus , Dräger Birgit
Published: February 2008

New plant oil crops are desirable as renewable resources for energy, for food purposes, and as building blocks in chemical synthesis. Fruit oil of Echinops sphaerocephalus was characterized by a high content of linoleic acid (over 70% of total fatty acids) and by a high tocopherol content (530–970 mg/kg oil). The majority was α‐tocopherol. Echinops sphaerocephalus plants may be cultivated in agricultural dimensions, and fruits may be obtained by a combine harvester. Echinops quinoline alkaloids present a useful by‐product of the oil production.
Direct and Efficient Glycosylation Protocol for Synthesizing α‐Glycolipids: Application to the Synthesis of KRN7000
Authors: Boutureira Omar , Morales‐Serna José Antonio , Díaz Yolanda , Matheu M. Isabel , Castillón Sergio
Published: February 2008

Herein we describe a simple and practical protocol for accessing the biologically active galactosyl ceramide KRN7000 and other α‐glycolipids with excellent yield and stereoselectivity by using per‐O‐silylated galactosyl iodide and stannyl ethers as glycosylation partners. This direct glycosylation reaction reduces the overall number of steps and provides rapid access to biologically important α‐galactosyl ceramide derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Nonenzymatic Glucose Sensor Using Nanoporous Platinum Electrodes Prepared by Electrochemical Alloying/Dealloying in a Water‐Insensitive Zinc Chloride‐1‐Ethyl‐3‐Methylimidazolium Chloride Ionic Liquid
Authors: Chou Chih‐Hung , Chen Jyh‐Cheng , Tai Chia‐Cheng , Sun I‐Wen , Zen Jyh‐Myng
Published: February 2008

We report here a nonenzymatic sensor by using a nanoporous platinum electrode to detect glucose directly. The electrode was fabricated by electrochemical deposition and dissolution of PtZn alloy in zinc chloride‐1‐ethyl‐3‐methylimidazolium chloride (ZnCl2‐EMIC) ionic liquid. Both SEM and electrochemical studies showed the evidences for the nanoporous characteristics of the as‐prepared Pt electrodes. Amperometric measurements allow observation of the electrochemical oxidation of glucose at 0.4 V (vs. Ag/AgCl) in pH 7.4 phosphate buffer solution. The sensor also demonstrates significant reproducibility in glucose detection; the higher the roughness factor of the Pt electrode, the lower the detection limit of glucose. The interfering species such as ascorbic acid and p‐acetamidophenol can be avoided by using a Pt electrode with a high roughness factor of 151. Overall, the nanoporous Pt electrode is promising for enzymeless detection of glucose at physiological condition.
Dielectrophoretic separation of platelets from diluted whole blood in microfluidic channels
Authors: Pommer Matthew S. , Zhang Yanting , Keerthi Nawarathna , Chen Dong , Thomson James A. , Meinhart Carl D. , Soh Hyongsok T.
Published: February 2008

The dielectrophoresis (DEP) phenomenon is used to separate platelets directly from diluted whole blood in microfluidic channels. By exploiting the fact that platelets are the smallest cell type in blood, we utilize the DEP‐activated cell sorter (DACS) device to perform size‐based fractionation of blood samples and continuously enrich the platelets in a label‐free manner. Cytometry analysis revealed that a single pass through the two‐stage DACS device yields a high purity of platelets (∼95%) at a throughput of ∼2.2×104 cells/second/microchannel with minimal platelet activation. This work demonstrates gentle and label‐free dielectrophoretic separation of delicate cells from complex samples and such a separation approach may open a path toward continuous screening of blood products by integrated microfluidic devices.
A preliminary characterization of the mutagenicity of atmospheric particulate matter collected during sugar cane harvesting using the Salmonella/microsome microsuspension assay
Authors: de Aragão Umbuzeiro Gisela , Franco Alexandre , Magalhães Dulce , de Castro Francisco José Viana , Kummrow Fábio , Rech Célia Maria , Rothschild Franco de Carvalho Lilian , de Castro Vasconcellos Pérola
Published: February 2008

During sugar cane harvesting season, which occurs from May to November of each year, the crops are burnt, cut, and transported to the mills. There are reports showing that mutagenic activity and PAH content increase during harvesting season in some areas of São Paulo State in comparison with nonharvesting periods. The objective of this work was to preliminarily characterize the mutagenic activity of the total organic extracts as well as corresponding organic fractions of airborne particulate matter (PM) collected twice from two cities, Araraquara (ARQ) and Piracicaba (PRB), during sugar cane harvesting season using the Salmonella/microsome microssuspension assay. One sample collected in São Paulo metropolitan area was also included. The mutagenicity of the total extracts ranged from 55 to 320 revertants per cubic meter without the addition of S9 and from not detected to 57 revertants per cubic meter in the presence of S9 in areas with sugar cane plantations. Of the three fractions analyzed, the most polar ones (nitro and oxy) were the most potent. A comparison of the response of TA98 with YG1041 and the increased potencies without S9 indicated that nitro compounds are causing the observed effect. More studies are necessary to verify the sources of the mutagenic activity such as burning of vegetal biomass and combustion of heavy duty vehicles used to transport the sugar cane to the mills. The Salmonella/microsome assay can be an important tool to monitor the atmosphere for mutagenicity during sugar cane harvesting season. Environ. Mol. Mutagen. 2008. © 2008 Wiley‐Liss, Inc.
Soil surface catalysis of Cr(VI) reduction by citric acid
Authors: Yang Jie Wen , Tang Zi Shou , Guo Rong Fa , Chen Sheng Qi
Published: February 2008

The objective of this study was to investigate the catalytic effect of a red soil rich in Fe‐oxides on the reduction of Cr(VI) by citric acid. Experimental results showed that the redox reaction would be greatly enhanced in the presence of the soil surfaces. The catalytic effect of the soil surfaces was very pronounced at low pH. Whereas with the increase in pH, the soil surfaces‐catalyzed redox reaction was gradually inhibited because reactant adsorption might be a necessary step for the heterogeneous redox reaction to take place. Although more adsorbed Cr(VI) would be released into the soil solution when citric acid coexisted with phosphate, the concentration of the reduced product Cr(III) in the equilibrium solution was lower than that in the system without phosphate, which further suggested that the reaction mainly occurred on the soil surfaces. The Fe(II)‐Fe(III) redox couple has also been found to accelerate the reaction. Cr(VI) could be directly reduced by the Fe(II) ions produced during the citric acid‐promoted reductive dissolution of Fe‐oxides in the soil. In addition, the kinetic studies showed that the presence of Fe(III) ions, also released from the dissolution process, could increase the Cr(VI) reduction rate by the citric acid. Information obtained from natural soil in this study is important for remediation of Cr(VI)‐contaminated soils by application of natural organic materials. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Economic analysis for wet oxidation processes for the treatment of mixed refinery spent caustic
Authors: Alnaizy Raafat
Published: February 2008

Sodium hydroxide (caustic) continues to be one of the primary reagents used in refineries and petrochemical plants to extract hydrogen sulfide, mercaptans, and organic acids from hydrocarbon streams. A local refinery had accumulated ∼5000 m3 of spent caustics containing cresylic and naphthenic compounds. The chemical oxygen demand (COD) concentrations must be reduced to less than 1 g/L prior to discharge to biotreatment. A simple and safe treatment system for this high volume and high concentration of COD is desired. Bench‐scale treatment of spent caustic by the Fenton's reagent process had a total COD removal of greater than 95%, and the effluent COD was lower than 1 g/L. The process was operated at a temperature lower than 80°C and ambient pressure. The capital cost was thus lower than that of the wet air oxidation (WAO) process that normally operates at 200°C and 28 bars. The cost of exporting spent caustic to a full‐service company in USA was $1.21 per gallon that was competitive with treatment at the individual generation sites on a short‐term basis. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
Identification of a molecular target for glutamate regulation of astrocyte water permeability
Authors: Gunnarson Eli , Zelenina Marina , Axehult Gustav , Song Yutong , Bondar Alexander , Krieger Patrik , Brismar Hjalmar , Zelenin Sergey , Aperia Anita
Published: February 2008

Astrocytes play a key role for maintenance of brain water homeostasis, but little is known about mechanisms of short‐term regulation of astrocyte water permeability. Here, we report that glutamate increases astrocyte water permeability and that the molecular target for this effect is the aquaporin‐4 (AQP4) serine 111 residue, which is in a strategic position for control of the water channel gating. The glutamate effect involves activation of group I metabotropic glutamate receptors (mGluR), intracellular calcium release, and activation of calcium/calmodulin‐dependent protein kinase II (CaMKII) and nitric oxide synthase (NOS). The physiological impact of our results is underlined by the finding that mGluR activation increases the rate of hypoosmotic tissue swelling in acute rat hippocampal slices. Cerebral ischemia is associated with an excessive release of glutamate, and in postischemic cerebral edema ablation of AQP4 attenuates the degree of damage. Thus, we have identified AQP4 as the molecular target for drugs that may attenuate the development of brain edema. © 2008 Wiley‐Liss, Inc.
International dynamic risk sharing
Authors: Cavaliere Giuseppe , Fanelli Luca , Gardini Attilio
Published: February 2008

In this paper we examine the implications of international risk sharing among a set of countries in the presence of market frictions which complicate the instantaneous adjustment to the first‐order conditions. We suggest approximating the consumption streams of countries belonging to the risk sharing coalition in terms of a disequilibrium dynamic model embodying forward‐looking adjustment. Econometric methods for estimating and testing the model are discussed. Empirical analysis of a set of core European countries suggests that once preference parameters are allowed to vary across countries, we are able to identify a group of nations that share risks against idiosyncratic permanent income shocks. The equilibrium position, however, is reached after a long adjustment period. Copyright © 2008 John Wiley & Sons, Ltd.
Extreme US stock market fluctuations in the wake of 9/11
Authors: Straetmans S. T. M. , Verschoor W. F. C. , Wolff C. C. P.
Published: February 2008

We apply extreme value analysis to US sectoral stock indices in order to assess whether tail risk measures like value‐at‐risk and extremal linkages were significantly altered by 9/11. We test whether semi‐parametric quantile estimates of ‘downside risk’ and ‘upward potential’ have increased after 9/11. The same methodology allows one to estimate probabilities of joint booms and busts for pairs of sectoral indices or for a sectoral index and a market portfolio. The latter probabilities measure the sectoral response to macro shocks during periods of financial stress (so‐called ‘tail‐βs’). Taking 9/11 as the sample midpoint we find that tail‐βs often increase in a statistically and economically significant way. This might be due to perceived risk of new terrorist attacks. Copyright © 2008 John Wiley & Sons, Ltd.
Structural breaks and GARCH models of exchange rate volatility
Authors: Rapach David E. , Strauss Jack K.
Published: February 2008

We investigate the empirical relevance of structural breaks for GARCH models of exchange rate volatility using both in‐sample and out‐of‐sample tests. We find significant evidence of structural breaks in the unconditional variance of seven of eight US dollar exchange rate return series over the 1980–2005 period—implying unstable GARCH processes for these exchange rates—and GARCH(1,1) parameter estimates often vary substantially across the subsamples defined by the structural breaks. We also find that it almost always pays to allow for structural breaks when forecasting exchange rate return volatility in real time. Combining forecasts from different models that accommodate structural breaks in volatility in various ways appears to offer a reliable method for improving volatility forecast accuracy given the uncertainty surrounding the timing and size of the structural breaks. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and characterization of polymeric implant for kyphoplasty
Authors: Mizrahi Boaz , Shavit Ronen , Domb Abraham
Published: February 2008

Copolymers of methyl methacrylate (MMA) and lauryl methacrylate (LMA) were prepared to obtain injectable ductile materials to be used in restoring vertebra height in kyphoplasty. Copolymers with Mw in the range of 130,000 and polydispersity of 1.8 were obtained. Several aspects of the effect of adding LMA monomers were examined including intrinsic viscosity, thermal properties, mechanical properties, and the ability to be injected under high pressure. By increasing the amount of LMA, the ductility of the polymer was increased, accompanied by a decrease in Young's modulus and strength. The copolymer with monomers ratio (MMA:LMA) 1:1 v/v possessed the most suitable mechanical properties and injectability, which may have potential clinical use in orthopedics. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 2008
Properties of an injectable low modulus PMMA bone cement for osteoporotic bone
Authors: Boger Andreas , Bohner Marc , Heini Paul , Verrier Sophie , Schneider Erich
Published: February 2008

The use of polymethylmethacrylate (PMMA) cement to reinforce fragile or broken vertebral bodies (vertebroplasty) leads to extensive bone stiffening. Fractures in the adjacent vertebrae may be the consequence of this procedure. PMMA with a reduced Young's modulus may be more suitable. The goal of this study was to produce and characterize stiffness adapted PMMA bone cements. Porous PMMA bone cements were produced by combining PMMA with various volume fractions of an aqueous sodium hyaluronate solution. Porosity, Young's modulus, yield strength, polymerization temperature, setting time, viscosity, injectability, and monomer release of those porous cements were investigated. Samples presented pores with diameters in the range of 25–260 μm and porosity up to 56%. Young's modulus and yield strength decreased from 930 to 50 MPa and from 39 to 1.3 MPa between 0 and 56% porosity, respectively. The polymerization temperature decreased from 68°C (0%, regular cement) to 41°C for cement having 30% aqueous fraction. Setting time decreased from 1020 s (0%, regular cement) to 720 s for the 30% composition. Viscosity of the 30% composition (145 Pa s) was higher than the ones received from regular cement and the 45% composition (100–125 Pa s). The monomer release was in the range of 4–10 mg/mL for all porosities; showing no higher release for the porous materials. The generation of pores using an aqueous gel seems to be a promising method to make the PMMA cement more compliant and lower its mechanical properties to values close to those of cancellous bone. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
The potential role of ribosomal protein S5 on cell cycle arrest and initiation of murine erythroleukemia cell differentiation
Authors: Matragkou Christina N. , Papachristou Eleni T. , Tezias Sotirios S. , Tsiftsoglou Asterios S. , Choli‐Papadopoulou Theodora , Vizirianakis Ioannis S.
Published: February 2008

Evidence now exists to indicate that some ribosomal proteins besides being structural components of the ribosomal subunits are involved in the regulation of cell differentiation and apoptosis. As we have shown earlier, initiation of erythroid differentiation of murine erythroleukemia (MEL) cells is associated with transcriptional inactivation of genes encoding ribosomal RNAs and ribosomal proteins S5 (RPS5) and L35a. In this study, we extended these observations and investigated whether transfection of MEL cells with RPS5 cDNA affects the onset of initiation of erythroid maturation and their entrance in cell cycle arrest. Stably transfected MEL cloned cells (MEL‐C14 and MEL‐C56) were established and assessed for their capacity to produce RPS5 RNA transcript and its translated product. The impact of RPS5 cDNA transfection on the RPS5 gene expression patterns and the accumulation of RPS5 protein in inducible transfected MEL cells were correlated with their ability to: (a) initiate differentiation, (b) enter cell cycle arrest at G1/G0 phase, and (c) modulate the level of cyclin‐dependent kinases CDK2, CDK4, and CDK6. The data presented indicate that deregulation of RPS5 gene expression (constitutive expression) affects RPS5 protein level and delays both the onset of initiation of erythroid maturation and entrance in cell cycle arrest in inducer‐treated MEL cells. J. Cell. Biochem. 104: 1477–1490, 2008. © 2008 Wiley‐Liss, Inc.
Praxis and power
Authors: Partridge William L.
Published: February 2008

This article examines Prilleltensky's concept of psychopolitical validity in terms of its locus within the continuum of individual‐relational‐collective well‐being. It argues that the strength of Prilleltensky's position is its emphasis on the need for structural changes in power relationships rather than the imposition of ameliorative interventions. Political action, however, is necessary to advance human well‐being by reducing power inequities. To do so, it is argued requires action that is targeted, measured, and replicable. Empowerment though action alone can become lasting. For that reason, the concept of “praxis” and its implications for the design of empowerment initiatives need to be understood and incorporated within discussions of psychopolitical validity. © 2008 Wiley Periodicals, Inc.
Concentrated disadvantage in urban neighborhoods: psychopolitical validity as a framework for developing psychology‐related solutions
Authors: Nation Maury
Published: February 2008

Psychology and community psychologists have been only peripherally involved in studying the sociopolitical factors including power differentials and resource inequities that are at the heart of the connection the between neighborhood conditions and individual well‐being. In this article, the author describes how the concept of psychopolitical validity provides community psychologists a framework for reconceptualizing the research on the effects of low‐income neighborhoods on well‐being. Specific elements of this framework include (a) analyzing the role of power in societal conceptions of social problems and targets of intervention, (b) posing research questions that illuminate the connection between individual and neighborhood well‐being, and (c) developing and implementing a range of techniques that both ameliorate an individual's symptoms and transform the neighborhood context. © 2008 Wiley Periodicals, Inc.
Transdisciplinary, multilevel action research to enhance ecological and psychopolitical validity
Authors: Christens Brian , Perkins Douglas D.
Published: February 2008

The authors explore the implications of recent proposals for a focus on power and social change in community psychology research and add needed contextual and methodological specificity. An expanded model of psychopolitical validity is presented that merges Isaac Prilleltensky's (this issue, pp. 116–136) domains, or stages of empowerment (oppression, liberation, wellness), with four ecological context domains (physical, sociocultural, economic, political) and greater clarity regarding levels of analysis. The physical–environmental context is used to illustrate some of the questions that may be generated by the expanded model. After discussing the role of democratic freedoms and institutions and the equitable distribution of decision‐making power in sustainable community development, the case is made for action research as a potent paradigm to move the field toward those goals. Multilevel and spatial analyses and transdisciplinary research (conceptually and/or methodologically integrative collaboration across multiple disciplines) are underutilized in Community Psychology. © 2008 Wiley Periodicals, Inc.
Confronting psychology's power
Authors: Fox Dennis
Published: February 2008

Isaac Prilleltensky (this issue, pp. 116–136) seeks to make community psychology a more effective force for social justice. His discussion of psychopolitical validity raises a number of questions: How perfect must the theoretical framework be to usefully oppose unjust power? In what way is the notion of “psychopolitical validity” most useful? How might an analysis of power apply to community psychology's own institutions? Is redirecting community psychology the most effective way to bring about transformative social change, or is success more likely to come outside psychology? Might more research aimed at understanding the mechanisms of oppression and liberation help oppressors more than liberators? And how can critical psychologists move beyond critique to action? The proposed framework will help facilitate social change only if community psychology also changes itself. © 2008 Wiley Periodicals, Inc.
Power from the people? critical reflection on a conceptualization of power
Authors: Fryer David
Published: February 2008

Isaac Prilleltensky's “The Role of Power in Wellness, Oppression, and Liberation: The Promise of Psychopolitical Validity” (2008) is commended as an interesting reading of the literature on power, which interestingly includes some and excludes other relevant writing. However, doubts are expressed as to whether the term “power,” as used in this article by Prilleltensky, is meaningful, necessary, useful, or advisable to community/critical psychology because it is fundamentally individualistic and psychologistic. Instead, it is proposed that power be understood as a dynamic of social systems rather than a property of individuals within them and that the apparent power of individuals is understood as the subjective manifestation of the societal distribution of power. Finally, it is suggested that Prilletensky's article itself functions in politically and ideologically conservative ways in relation to a number of problematically powerful interest groups. © 2008 Wiley Periodicals, Inc.
On power, psychopolitical validity, and play
Authors: Angelique Holly L.
Published: February 2008

In this commentary, the author discusses power as a useful concept for community psychology. Although Prilleltensky's analysis of power (this issue, pp. 116–136) has the potential to shift the ideological foundation of the field, the author notes that he focuses primarily on the ability to coerce and/or resist coercion. The author argues that other conceptions of power should be considered to promote wellness, resist oppression, and move toward liberation. The author discusses ways in which power is manifested and may be exposed. Specifically, the author offers a Foucauldian perspective on power relations and challenge individuals to examine the multiple ways that power is manifested in our own lives. © 2008 Wiley Periodicals, Inc.
Psychopolitical validity: power, culture, and wellness
Authors: Fisher Adrian T. , Sonn Christopher C.
Published: February 2008

In this commentary, the authors review and critique Prilleltensky's model of psychopolitical validity and wellness. Although the overt recognition of power, oppression, and political forces are viewed most favorably, cautions are also given. Of most importance is the way in which his model is based in an undeclared North American model of psychology and culture. The authors examine the disjuncture between the stated aims of psychopolitical validity and the ways in which different cultures and social systems construe the world. The proposal for a political focus on power and oppression is welcomed, but cautions are offered about the commensurability of different worldviews and practices. © 2008 Wiley Periodicals, Inc.
PU.1 and NFATc1 mediate osteoclastic induction of the mouse β3 integrin promoter
Authors: Crotti Tania N. , Sharma Sudarshana M. , Fleming Joseph D. , Flannery Merrilee R. , Ostrowski Michael C. , Goldring Steven R. , McHugh Kevin P.
Published: February 2008

Expression of the αvβ3 integrin is required for normal osteoclast function. We previously showed that an evolutionary conserved NFATc1 binding site is required for RANKL induction and NFATc1 transactivation of the human β3 promoter. The mechanism conferring specificity for RANKL induction and NFATc1 transduction of the β3 gene in osteoclast differentiation is unclear since NFATc1 is expressed and activated in numerous cell types that do not express the β3 gene. PU.1 is an ETS family transcription factor in myeloid cells associated with expression of various osteoclast genes. The present study investigates the role of NFATc1 in concert with PU.1 in osteoclast‐specific transcription of the mouse β3 integrin gene. The mouse β3 promoter was transactivated by NFATc1 in RAW264.7 cells and deletion or mutation of either of the conserved NFAT and PU.1 binding sites abrogated transactivation. NFATc1 transactivation of the mouse β3 promoter was specifically dependent on co‐transfected PU.1 in HEK293 cells, to the exclusion of other ETS family members. Direct binding of NFATc1 and PU.1 to their cognate sequences was demonstrated by EMSA and NFATc1 and PU.1 occupy their cognate sites in RANKL‐treated mouse marrow precursors in chromatin immuno‐precipitation (ChIP) assays. TAT‐mediated transduction with dominant‐negative NFATc1 dose‐dependently blocked endogenous expression of the mouse β3 integrin and the formation of TRAP positive multinucleated cells in RANKL‐treated mouse macrophages. These data provide evidence that NFATc1, in concert with PU.1, are involved in regulation of β3 integrin expression during osteoclast differentiation and suggest that PU.1 confers specificity to the NFATc1 response to macrophage lineage cells. J. Cell. Physiol. 215: 636–644, 2008. © 2008 Wiley‐Liss, Inc.
NAADP‐induced Ca2+signaling in response to endothelin is via the receptor subtype B and requires the integrity of lipid rafts/caveolae
Authors: Gambara Guido , Billington Richard A. , Debidda Marcella , D'Alessio Alessio , Palombi Fioretta , Ziparo Elio , Genazzani Armando A. , Filippini Antonio
Published: February 2008

We have investigated the role of NAADP‐mediated Ca2+mobilization in endothelin (ET) signaling via endothelin receptor subtype A (ETA) and endothelin receptor subtype B (ETB) in rat peritubular smooth muscle cells. Microinjection and extracellular application of NAADP were both able to elicit Ca2+release which was blocked by inhibitory concentrations of NAADP, by impairing Ca2+uptake in acidic stores with bafilomycin, and by thapsigargin. Ca2+release in response to selective ETB stimulation was abolished by inhibition of NAADP signaling through the same strategies, while these treatments only partially impaired ETA‐dependent Ca2+signaling, showing that transduction of the ETB signal is dependent on NAADP. In addition, we show that lipid rafts/caveolae contain ETA, ETB, and NAADP/cADPR generating enzyme CD38 and that stimulation of ETB receptors results in increased CD38 activity; interestingly, ETB‐ (but not ETA‐) mediated Ca2+responses were antagonized by disruption of lipid rafts/caveolae with methyl‐β‐cyclodextrin. These data demonstrate a primary role of NAADP in ETB‐mediated Ca2+signaling and strongly suggest a novel role of lipid rafts/caveolae in triggering ET‐induced NAADP signaling. J. Cell. Physiol. 216: 396–404, 2008. © 2008 Wiley‐Liss, Inc.
Surface‐assisted laser desorption/ionization mass spectrometry (SALDI‐MS) of low molecular weight organic compounds and synthetic polymers using zinc oxide (ZnO) nanoparticles
Authors: Watanabe Takehiro , Kawasaki Hideya , Yonezawa Tetsu , Arakawa Ryuichi
Published: February 2008

We have developed surface‐assisted laser desorption/ionization mass spectrometry using zinc oxide (ZnO) nanoparticles with anisotropic shapes (ZnO‐SALDI‐MS). The mass spectra showed low background noises in the low m/z, i.e. less than 500 u region. Thus, we succeeded in SALDI ionization on low molecular weight organic compounds, such as verapamil hydrochloride, testosterone, and polypropylene glycol (PPG) (average molecular weight 400) without using a liquid matrix or buffers such as citric acids. In addition, we found that ZnO‐SALDI has advantages in post‐source decay (PSD) analysis and produced a simple mass spectrum for phospholipids. The ZnO‐SALDI spectra for synthetic polymers of polyethylene glycol (PEG), polystyrene (PS) and polymethylmethacrylate (PMMA) showed the sensitivity and molecular weight distribution to be comparable to matrix‐assisted laser desorption/ionization (MALDI) spectra with a 2,5‐dihydroxybenzoic acid (DHB) matrix. ZnO‐SALDI shows good performance for synthetic polymers as well as low molecular weight organic compounds. Copyright © 2008 John Wiley & Sons, Ltd.
The epineural sleeve technique for nerve graft reconstruction enhances nerve recovery
Authors: Lubiatowski Przemyslaw , Unsal Faik M. , Nair Dileep , Ozer Kagan , Siemionow Maria
Published: February 2008

The purpose of the study was evaluation of nerve recovery following epineural sleeve technique for graft reconstruction in rat sciatic nerve. This technique provides the epineural sleeve to cover and separate the site of coaptation. Animals were divided into three groups: CNG‐conventional nerve grafting, ESN‐epineural sleeve from recipient nerve stumps, ESG‐epineural sleeve from graft. Nerve regeneration was evaluated by pin‐prick, toe‐spread test, walking track analysis and somatosensory‐evoked potentials (SEP), gastrocnemius index (GI), and histomorphometric evaluation. Most parameters (SFI, SEPs, and GI) showed significantly better nerve recovery for ESN group when compared to conventional CNG group. Also ESG group revealed better result for SFI. Better functional results for ESN and ESG groups were further confirmed by histomorphometric analysis: higher axon density and diameters as well as thicker myelin sheath. Epineural sleeve graft technique may be promising method with potential application for nerve reconstructive procedures. Better functional nerve recovery can be anticipated. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
A new training method to improve deep microsurgical skills using a mannequin head
Authors: Takeuchi Mikinobu , Hayashi Nakamasa , Hamada Hideo , Matsumura Nobuhisa , Nishijo Hisao , Endo Shunro
Published: February 2008

Neurosurgeons need fine and special microsurgical techniques, such as the ability to suture deep microvasculature. Intensive training is required to perform microsurgery, especially in deep microvascular anastomosis. There have been many previous reports of training methods for typical microsurgical techniques, including suturing of surgical gloves, Silastic tubes, living animals, and chicken wing arteries. However, there have been no reports of training methods to improve deep microsurgical skills under the various hand positions specific to neurosurgical operation. Here, we report a new training method using a mannequin head, water balloons, and clay to mimic actual deep microsurgery in the brain. This method allows trainees to experience microsurgery under various hand positions to approach the affected areas located at various depths in the brain from various angles. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Remark on the regularity for weak solutions to the magnetohydrodynamic equations
Authors: He Cheng , Wang Yun
Published: February 2008

We study the regularity criteria for weak solutions to the incompressible magnetohydrodynamic (MHD) equations. Some regularity criteria, which are related only with u+B or u−B, are obtained for weak solutions to the MHD equations. Copyright © 2008 John Wiley & Sons, Ltd.
A compact sharp‐rejection lowpass filter
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Yang Ru‐Yuan
Published: February 2008

In this article, a compact sharp‐rejection lowpass filter (SRLPF) is proposed and analyzed. By combining the coupled line section and shunt open‐circuited resonator, a compact lowpass filter with wide stopband and very high passband selectivity is realized. This filter at cutoff frequency fc of 2 GHz has presented very good measured characteristics, including very low insertion loss of 0.15 ± 0.05 dB, wide stopband from 3.2 to 8 GHz and attenuation slope of 51 dB/GHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 894–896, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23224
Optical filters for fiber lasers and amplifiers
Authors: Rego G.
Published: February 2008

We discuss the writing of arc‐induced long‐period fiber gratings to be used as optical filters in Er/Yb fiber lasers and for flattening the gain spectra of Er‐doped fiber amplifiers. A new approach for the fabrication of filters with complex profiles is also presented. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 890–894, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23225
Cylindrical dipoles as ultra‐wide band antennas: An energy‐based analysis
Authors: Tamas Razvan D. , Babour Laurence , Fond Emilie , Slamnoiu Georgica , Chilo Jean , Saguet Pierre
Published: February 2008

Cylindrical antennas are well‐suited for military ultra‐wide band (UWB) applications. In this article, we evaluate energy‐based descriptors for three relevant types of cylindrical dipoles, including a novel stacked antenna. We show that the energy‐based analysis provide a more realistic view on the transient radiation than the classical frequency‐domain analysis. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 917–921, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23230
UWB antenna array for wireless transmission along corridors
Authors: Liu H.‐Z. , Coetzee J. C. , Mouthaan K.
Published: February 2008

A 2‐element elliptical patch antenna array with a bidirectional radiation pattern has been developed for ultra wideband indoor wireless communications. The array is constructed by means of feeding two omni‐directional elliptical patch elements with a 3‐section hybrid power divider. Experimental results show that the array has a stable radiation pattern and low return loss over a broad bandwidth of 64% (3.1–6 GHz). © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 886–890, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23232
MMIC PAM applied with pre‐distorter having independent operation of nonlinear signal
Authors: Oh Inn‐Yeal , Kim Ki‐Byoung , Ra Keuk‐Hwan , Park Chul‐Soon
Published: February 2008

A dynamic pre‐distorter with two paths to set nonlinear signal level and phase encourages power amplifier module (PAM) for wireless broadband (Wibro) service to enhance linearity. We proposed a linearizer having a new IM generator, which is made up of the InGaP/GaAs HBT operated at saturation region of a common collector circuit. The targeted Wibro PAM is designed using InGaP/GaAs HBT technology, and the pre‐distorter, drive and power amplifier are fully integrated in single chip within 960 × 2400 μm. Even though PAM is designed to have just a 5‐dB back‐off, PAM is compatible with linearity standards up to maximum output power 21 dBm, and has a 17.5% efficiency by having a low leakage and improving spurious of 6 dB in the 64QAM form based on IEEE802.16e‐2005 standards. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 851–855, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23235
An ultra‐wideband microstrip elliptical slot antenna excited by a circular patch
Authors: Lao Jia , Jin Ronghong , Geng Junping , Wu Qi
Published: February 2008

A novel ultra‐wide band printed slot antenna is presented. By using the novel feeding structure of a circular patch with a tapered microstrip line, the bandwidth of the elliptical slot antenna is greatly enhanced. The impedance bandwidth (VSWR < 2) reaches 174%, covering 1.90–27.7 GHz with bandwidth ratio of 14.6:1. This novel structure also features a bidirectional radiation pattern and a thin profile, making it promising in various wideband applications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 845–846, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23240
Coplanar waveguide wideband fractal Koch antenna
Authors: Jahanbakht M. , Lotfi Neyestanak A. A. , Naser‐Moghaddasi M.
Published: February 2008

The slot antenna is attractive for use in many applications. These antennas have several useful properties such as wider impedance bandwidth compared with the microstrip patch antennas, and easier integration with solid‐state, MIC, MMIC, and Micro Electro Mechanical Systems (MEMS). In this study, the novel wideband design of a coplanar waveguide fed fractal slot antenna is proposed and experimentally studied. The return loss, impedance matching and radiation pattern parameters of such a structure will be studied and in one case it would be measured. The obtained results show that the impedance bandwidth of the fractal slot antenna can be 52% which almost covers the entire S‐band. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 936–939, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23241
Bode and Fano impedance matching
Authors: Hansen R. C.
Published: February 2008

The Bode limit on bandwidth enhancement through use of an ideal impedance matching network does not allow changes in antenna reflection coefficient over the bandwidth. An exact correction factor is derived from the Fano limitations, yielding a simple modification to the Bode limit. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 875–877, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23244
Diakoptic approach to analysis of multiconductor transmission lines
Authors: Olćan Dragan I. , Stevanović Ivica M. , Mosig Juan R. , Djordjević Antonije R.
Published: February 2008

We present a general method for numerical analysis of electrically large electromagnetic‐field problems, which is based on merging diakoptic approach and surface integral‐equation formulations. Compared with the classical approach, the proposed method provides significant reduction of c.p.u. time and storage, preserving high accuracy of results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 931–936, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23246
An experimental load matching technique for RF CMOS power amplifier
Authors: Eo YunSeong , Lee Seung‐Joon , Baek Dong‐Hyun
Published: February 2008

A load matching method for CMOS PA (power amplifier) design is proposed. The contours for RF power and efficiency can be drawn while considering external L and C as tunable X and Y variables. On the basis of the existence of this contour, the realization of load matching of CMOS PA is easily achieved and optimized. A tested CMOS PA based on 0.18 μm CMOS technology shows a design example whose P1dB is 17.8 dBm and power efficiency 37%, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 899–902, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23248
A novel high performance microstrip diplexer for ultra‐wideband wireless communications
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Yang Ru‐Yuan
Published: February 2008

A novel compact and high performance microstrip diplexer for ultra‐wideband communication is designed and implemented. This microstrip diplexer is simply composed of two coupled line structures and three tapped open stubs. The design concept has been verified by the experimental results of the fabricated diplexer, including the two isolated wideband bandwidths of 3–5 GHz and 6–10 GHz, low insertion loss and high isolation due to attenuation poles located between two channels. Experimental results also show a good agreement with the simulated results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 921–923, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23252
Time and frequency observation of pulse amplitude equalization of harmonic mode‐locked fiber laser
Authors: Hu Li‐Chiang , Liu Nan‐Hsin , Yang Lan‐Chih , Lin Huang‐Chang , Tsao Shyh‐Lin
Published: February 2008

In this article, we achieve the output observation in time and frequency domain of a rational harmonic mode‐locked fiber laser (RHMLFL). The pulse amplitude of pulse train is equalized by operating at nonlinear modulation transfer function region of active modulator in RHMLFL. Without adding any other additional predistortion components, amplitude equalized short pulses up to the fourth order rational harmonic mode‐locking are successfully demonstrated for 7.5, 10, and 15 GHz. One can extend such a method for various mode‐locked lasers even with much higher repetition rates. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 957–961, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23256
Design of the compact SIR‐based bandpass filter with a wide stopband
Authors: Pan Heng‐Yau , Wu Hung‐Wei , Weng Min‐Hang
Published: February 2008

Compact coupled stepped impedance resonators (SIRs) are used to design the bandpass filter (BPF) with a wide stopband. In the filter design, two different physical dimensions of the SIRs are used to produce proper required coupling for the frequency response with wide spurious suppression. The theory and guidelines for selecting the geometric parameters of SIRs are clearly presented in this paper. The BPF designed with center frequency (f0) at 2.45 GHz has a stopband extended up to 20 GHz (8.16f0) and an average rejection level better than 25 dB. Good agreement between the electromagnetic simulation and measurement is observed. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 948–952, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23261
Etched ring absorbing waveguide filter based on a slotted waveguide antenna response
Authors: Stander Tinus , Meyer Petrie
Published: February 2008

A cascade of resistively loaded etched rings in waveguide is proposed to act as the load in a balanced FMCW reflected power canceller topology using a slotted waveguide array antenna. A synthesis technique using derived equivalent circuit models is presented and tested. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 977–981, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23262
A folded thin‐wire monopole antenna loaded by a rectangular dielectric resonator
Authors: Tsai Ching‐Long , Deng Sheng‐Ming , Chen Tsung‐Wen , Chang Yung ‐Cheng
Published: February 2008

A rectangular ceramic dielectric resonator loaded into a folded thin‐wire monopole antenna in a horizontal finite ground plane is presented. While in a suitable adjustment, the impedance bandwidth of the proposed antenna is 67% (2.15–4.30 GHz). Moreover, the electric dipole pattern is kept in such antenna configuration. Additionally, antenna gain is about 2–4 dBi in the operating frequencies. The antenna configuration and performance is very suitable to apply in the wide‐band territorial communications. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 939–942, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23268
Erratum: Design of a novel compact antenna for a bluetooth LTCC module
Authors: Seo Donghyun , Jeon Seunggil , Kang Namkee , Ryu Jong in , Choi Jae‐Hoon
Published: February 2008

Originally published Microwave Opt Technol Lett 50 (2008) 180–183. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1133, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23269DOI 10.1002/mop.23269
Dual‐band baluns for reducing the influence of feed cable in antenna measurement
Authors: Hsue Ching‐Wen , Lin Yi‐Chia , Chen Kuo‐Lung
Published: February 2008

In order to obtain accurate radiation characteristics of an antenna, it is required to reduce unbalanced current on the surface of the feeding cable. A miniaturized balun of stacked coaxial cavities is presented to show high input impedances at two separate bands. An equivalent circuit with transmission lines, and inductive and capacitive elements is employed to characterize the circuit behavior of the dual‐band balun. In particular, the method to design a dual‐band balun, with arbitrary ratio of the upper resonant frequency to the lower resonant frequency, is presented to facilitate the design process. Both numerical values and experimental results are presented to illustrate the validity of the design method. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1000–1004, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23270
Design of the wideband dual‐mode bandpass filter using stepped impedance resonators
Authors: Hung Cheng‐Yuan , Weng Min‐Hang , Jhong Shih‐Bin , Wu Sean , Lee Maw‐Shung
Published: February 2008

In this letter, a novel dual‐mode bandpass filter (BPF) using stepped impedance resonators (SIRs) for simultaneous low insertion‐loss and wide passband has been designed. This novel wideband dual‐mode BPF is formed by a microstrip square ring resonator with direct‐connected orthogonal feed lines, and two impedance steps as perturbations. By varying the impedance ratio (K) of the SIRs, the wideband bandwidth can be tuned with more freedoms. The design procedure using the analysis of even and odd mode is described in this paper. The wideband BPF with relative bandwidth of 76.5% is simulated using the full wave electromagnetic simulation, and then fabricated and measured using the network analyzer. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1104–1107, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23281