bluuebunny/crossref_metadata_2025 huggingface dataset:
Removal of phenolic compounds in pomegranate juices using ultrafiltration and laccase‐ultrafiltration combinations
Authors: Alper Neslihan , Acar Jale
Published: June 2004

Phenolic compounds of fruit juices are responsible for haze and sediment formation as well as for color, bitterness and astringency. The influence of ultrafiltration (UF) and laccase‐UF combination was investigated on phenolic contents of pomegranate juices and on filtration output. Laccase‐treated and then ultrafiltered pomegranate juices have shown a rapid increase in their color, when compared to only ultrafiltered (control) samples. Kinetic parameters of laccase were also determined. During the oxidation period, the changes occurring in pomegranate juices were estimated from phenolic contents, color and anthocyanin measurements. Results have shown that laccase oxidation produced a significant decrease in phenolic content of pomegranate juices while juice color the increased. However, in recent literatures, the possibility to remove polyphenols in apple juices was reported. We decided in this study that laccase treatment can not be applied due to the loss of natural red color and unwanted dark brownish color formation in pomegranate juice.
Effect of γ‐radiation and microwave heating of wheat grain on some starch properties in irradiated grain as well as in grain of the next generation crops
Authors: Dolińska Romualda , Warchalewski Jerzy R. , Gralik Justyna , Jankowski Tomasz
Published: June 2004

Grains of the Polish winter wheat variety Begra were subjected to γ‐radiation (grain harvested in 1996) within the dose range of 0.05–10 kGy and microwave heating (grain harvested in 1997) from 28°C to 98°C. Later the grains were divided into two parts, the first was used for direct analyses after treatment. The second part was sown on the experimental fields. The obtained crop was described as the first generation and divided into two parts. One part was destined to determination of starch properties and the second part was sown in order to obtain the second generation crop. The same pattern was conducted in order to achieve the third generation crop. γ‐Irradiation directly applied on the wheat grain reduced statistically significant falling number values and gelatinisation enthalpy (ΔH) of the grain treated by 5 and 10 kGy. Calculated linear regression correlation coefficient between the falling number values and the gelatinisation enthalpy was equal to 0.94 (p ⪇ 0.001) and showed that these two starch characteristics are well correlated in the case of directly irradiated wheat grain. The falling number values, peak temperatures (Tp) and gelatinisation enthalpy (ΔH), in three generations of wheat grain crop studied, did not show any statistically significant differences as a result of indirect effect of γ‐irradiation. Microwave direct heating of wheat grain to 98°C caused a statistically significant increase in the falling number value and decrease in starch gelatinisation power expressed by the enthalpy of gelatinisation (ΔH). The statistically significant changes in the falling number values, slight changes in the peak temperatures (Tp) and enthalpy of gelatinisation (ΔH) were found in all three generation crops as an indirect effect of microwave heating.
Antioxidant and angiotension‐converting enzyme inhibition capacities of various parts of Benincasa hispida (wax gourd)
Authors: Huang Hui‐Yu , Huang Ju‐Jen , Tso Tim K. , Tsai Ying‐Chieh , Chang Chen‐Kang
Published: June 2004

Vegetables and fruits have been shown to be good sources of antioxidants. Benincasa hispida (wax gourd) has been used in traditional Chinese medicine to treat hypertension and inflammation. The aims of this study were to investigate the abilities of antioxidation and inhibition of angiotensin‐converting enzyme (ACE) activity of wax gourd pulp, core, seed, and peel prepared by different extraction methods. The fresh weights required to reach 50% inhibition of linoleic acid oxidation were higher in fresh extracts, compared to other extraction methods. Fresh weights required to reach 50% inhibition were the lowest in seed. The seed had the lowest Cu2+‐induced low‐density lipoprotein (LDL) oxidation percentage and inhibition level of ACE activity among all parts. The higher antioxidant capacity of the seed may result from the higher total phenolics contents and superoxide dismutase activity. The abilities of antioxidation and ACE activity inhibition may provide protective effects against cardiovascular diseases and cancers.
Effect of γ‐irradiation on aflatoxin B1 production by Aspergillus flavus and chemical composition of three crop seeds
Authors: Aziz Nagy H. , Mahrous Souzan R.
Published: June 2004

The effect of γ‐irradiation on aflatoxin B1 production by Aspergillus flavus, and the chemical composition of some different crop seeds were investigated. A. flavus infected seeds behaved differently according to their principal constituents. A. flavus caused an increase in protein and decrease in lipids and carbohydrate contents of wheat, soyabean and fababean seeds. Growth of A. flavus and production of aflatoxin B1 was inhibited at a dose level of 5 kGy. A. flavus utilizes carbohydrates of seeds for its growth and aflatoxin production. Crops were arranged, in descending order, according to aflatoxin produced in seeds as wheat > soyabean > fababean. There were no changes in chemical constituents of irradiated seeds, such as protein, lipids, and carbohydrates.
Casein gelation under simultaneous action of transglutaminase and glucono‐δ‐lactone
Authors: Menéndez Orquídea , Schwarzenbolz Uwe , Rohm Harald , Henle Thomas
Published: June 2004

Casein solutions (5% w/v) were treated with microbial transglutaminase (MTG) and glucono‐δ‐lactone (GDL) under varying conditions in order to obtain gels. Storage modulus (G ′) and gelation time of the gels were measured by oscillation rheometry, while protein cross‐linking was determined by gel permeation chromatography. The addition of only GDL to milk resulted in very weak gels, while MTG on its own was not able to create gel networks. Simultaneous action of both ingredients led to gels, the firmness of which was linearly related to the added amount of MTG, but passed through a maximum with rising GDL concentrations. Using chromatographical analysis, increasing G ′ values were interrelated with the formation of MTG‐induced oligomers. The gelation time was directly proportional to the GDL concentration but not influenced by the addition of MTG within the studied range of concentration.
Loss of chromosome arm 18q with tumor progression in head and neck squamous cancer
Authors: Takebayashi Satoru , Hickson Arthur , Ogawa Tetsuya , Jung Kwang‐Yoon , Mineta Hiroyuki , Ueda Yo , Grénman Reidar , Fisher Susan G. , Carey Thomas E.
Published: June 2004

Loss of 18q was analyzed in 21 sets of head and neck squamous cell carcinoma (HNSCC) cell lines derived from primary and secondary tumors in the same patients. Only 3 of the 21 cell line pairs had no loss of 18q. In the remaining 18 sets, loss of heterozygosity (LOH) affecting 18q was found in either the primary or the secondary lines or both. In every case but one, the same chromosome was affected in both the primary and secondary cell lines. In 8 sets, the 18q loss occurred in the primary tumor and remained stable through the subsequent tumor progression. The primary and secondary lines differed in 18q loss in 10 of 18 (56%) cases with 18q LOH. In 3 of the 10 pairs that differed, 18q LOH was found in only the primary line, indicating that the loss developed after the metastatic or recurrent tumor population had diverged from the primary tumor population. In the other 7 pairs, 18q LOH developed or progressed with tumor recurrence or metastasis. Of these, 3 of 7 had 18q LOH in only the secondary lines, and 4 of 7 had 18q LOH in both the primary and secondary lines, but the extent of LOH was greater in the secondary lines than in the primary lines, indicating that additional rearrangements of the same chromosome occurred with progression. These cases showed that interstitial loss often progresses to consolidated loss in vivo. However, in vitro, the cell lines from the primary tumors with interstitial loss maintain those chromosomes over long‐term culture. LOH on 18q in cell lines from previously untreated primary tumors was significantly associated with advanced tumor stage (P = 0.0242) and decreased survival (P = 0.0453). The findings are consistent with the concept that 18q LOH is an event associated with tumor progression and suggest that inactivation and loss of one or more genes on 18q contributes to aggressive tumor behavior. © 2004 Wiley‐Liss, Inc.
The effect of fouling on nucleate pool boiling of small wires
Authors: Fukada Yusuke , Haze Ikuya , Osakabe Masahiro
Published: June 2004

Pool boiling experiments with small diameter wires were conducted in earth gravity and microgravity conditions. Bare wire and fouled wire with a scale deposition of calcium carbonate was used. The wettability on the scale wire was higher than that on the bare wire. Though more vigorous bubbling was observed on the scale wire when compared to that on the bare wire at the same heat flux, the boiling curve for the scale wire was approximately the same as that on the bare wire. However, the critical heat flux (CHF) on the scale wire was higher than that of the bare wire. On the scale wire, the departure diameter of bubbles was relatively smaller than that on the bare wire. The smaller diameter of bubbles detaching from the scale wire is considered to be due to the high wettability and high nucleation site density. As the result, the coalescence of bubbles near the wire was prevented, and the CHF was delayed and increased on the scale wire when compared to that on the bare wire. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 316–329, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20016
An experimental study of heat transfer enhancement with a pulsating flow
Authors: Jun Zheng , Danling Zeng , Ping Wang , Hong Gao
Published: June 2004

A pulsating flow in a pipe was experimentally investigated to determine the effect of pulsation on the rate of heat transfer. The influence of hydrodynamic parameters and characteristics of the pulsation on heat transfer was carefully studied. In order to adjust the pulsating parameters, a self‐oscillator was designed so the length of the resonator and the length of the outlet nozzle could be adjusted. The results show that the heat transfer rate is strongly affected by both the hydrodynamic parameters and the configuration of the resonator. With the increase of the flow rate of the liquid and the length of the chamber, heat transfer is enhanced. There is an optimal length at which the heat transfer enhancement attends to the best. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(5): 279–286, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20020
Lysophospholipid receptor‐dependent and ‐independent calcium signaling
Authors: Meyer zu Heringdorf Dagmar
Published: June 2004

Changes in cellular Ca2+ concentrations form a ubiquitous signal regulating numerous processes such as fertilization, differentiation, proliferation, contraction, and secretion. The Ca2+ signal, highly organized in space and time, is generated by the cellular Ca2+ signaling toolkit. Lysophospholipids, such as sphingosine‐1‐phosphate (S1P), sphingosylphosphorylcholine (SPC), or lysophosphatidic acid (LPA) use this toolkit in a specific manner to initiate their cellular responses. Acting as agonists at G protein‐coupled receptors, S1P, SPC, and LPA increase the intracellular free Ca2+ concentration ([Ca2+]i) by using the classical, phospholipase C (PLC)‐dependent pathway as well as PLC‐independent pathways such as sphingosine kinase (SphK)/S1P. The S1P1 receptor, via protein kinase C, inhibits the [Ca2+]i transients caused by other receptors. Both S1P and SPC also act intracellularly to regulate [Ca2+]i. Intracellular S1P mobilizes Ca2+ in intact cells independently of G protein‐coupled S1P receptors, and Ca2+ signaling by many agonists requires SphK‐mediated S1P production. As shown for the FcεRI receptor, PLC and SphK may contribute specific components to the overall [Ca2+]i transient. Of the many open questions, identification of the intracellular S1P target site(s) appears to be of particular importance.
Thrombogenic and atherogenic activities of lysophosphatidic acid
Authors: Siess Wolfgang , Tigyi Gabor
Published: June 2004

Lysophosphatidic acid (LPA) has been identified as a biologically active lipid in mildly‐oxidized LDL, human atherosclerotic lesions, and the supernatant of activated platelets. The evidence that LPA has thrombogenic and atherogenic activities has increased substantially in recent years. Supporting the thrombogenic activity of LPA, analysis of the core region of human carotid plaques revealed recently the presence of alkyl‐ and acyl‐molecular species from LPA with high platelet‐activating potency (16:0 alkyl‐LPA, 20:4 acyl‐LPA). LPA, lipid extracts of atherosclerotic plaques, and the lipid‐rich core elicited shape change and, in synergy with other platelet stimuli, aggregation of isolated platelets. This effect was completely abrogated by prior incubation of platelets with LPA receptor antagonists. Furthermore, LPA at concentrations approaching those found in vivo, induced platelet shape change, aggregation, and platelet‐monocyte aggregate formation in blood. LPA‐stimulated platelet aggregation was mediated by the ADP‐stimulated activation of the P2Y1 and P2Y12 receptors. Supporting its atherogenic activity, LPA is a mitogen and motogen to vascular smooth muscle cells (VSMCs) and an activator of endothelial cells and macrophages. Recently, LPA has been identified as an agonist of the peroxisome proliferator activating receptor γ (PPARγ), which is a key regulator of atherogenesis. LPA elicits progressive neointima formation, which is fully abolished by GW9662, an antagonist of PPARγ. We propose that LPA plays a central role in eliciting vascular remodeling and atherogenesis. Furthermore, upon rupture of lipid‐rich atherosclerotic plaques, LPA may trigger platelet aggregation and intra‐arterial thrombus formation. Antagonists of LPA receptors might be useful in preventing LPA‐elicited thrombus formation and neointima formation in patients with cardiovascular diseases. © 2004 Wiley‐Liss, Inc.
Expression and DNA‐binding activity of MYCN/Max and Mnt/Max during induced differentiation of human neuroblastoma cells
Authors: Smith Anna Grynfeld , Popov Nikita , Imreh Martha , Axelson Håkan , Henriksson Marie
Published: June 2004

Amplification ofMYCNis one of the most important prognostic markers for neuroblastoma and is correlated with rapid tumor progression and poor prognosis. MYCN belongs to the Myc/Max/Mad/Mnt network of proteins that regulate proliferation, apoptosis, and differentiation. It is well established thatMYCNis downregulated during induced differentiation of neuroblastoma cells carrying an amplifiedMYCNgene, but very little is known about other components of the network, i.e., the Max, Mad, and Mnt proteins, during this process. In this study we show thatMad and Mnt expressionwas only modestly regulated in differentiating SK‐N‐BE(2) neuroblastoma cells, whileMYCNwas rapidly downregulated. This downregulation was reflected in a decreased MYCN/Max DNA‐binding activity while the Mnt/Max binding did not change during differentiation. In parallel experiments we also analyzed the Myc/Max/Mad expression and DNA binding capacity during induced differentiation in theMYCNsingle copy neuroblastoma cell line SH‐SY5Y. In this cell line only modest changes in expression of the components of the MYCN/Max/Mad/Mnt network was detected, but since the cell line expresses relatively low levels of MYCN and c‐Myc, these changes might be of functional significance. Cell cycle analyses of SK‐N‐BE(2) demonstrated an increase in the G1‐phase fraction after RA‐treatment. These data show that the decreasedMYCNexpression and MYCN DNA‐binding is correlated with retarded cell cycle progression. Furthermore, whenMad1 or Mntwas overexpressed in SK‐N‐BE(2) cells they retained the capacity to differentiate, underscoring the notion that MYCN downregulation, and not changes inMad/Mntexpression, is essential for neuroblastoma cell differentiation. © 2004 Wiley‐Liss, Inc.
Soluble form of Jagged1: Unique product of epithelial keratinocytes and a regulator of keratinocyte differentiation
Authors: Aho Sirpa
Published: June 2004

Notch signaling pathway is an important regulator of epithelial differentiation. Recent studies have characterized multiple ligands, including Jagged1, as mediators of Notch signaling. In this work, an alternatively spliced transcript of Jagged1 was isolated in yeast two‐hybrid screening through interaction with thrombospondin‐1. This transcript, devoid of sequences encoding the transmembrane and intracellular domains of Jagged1, was specific for keratinocytes. Furthermore, the truncated Jagged1 polypeptide devoid of the intracellular domain was detected prominently in the suprabasal keratinocyte layer in neonatal epithelia. The soluble form of Jagged1, when expressed as a tagged polypeptide was efficiently secreted into the culture medium and the N‐terminal signal sequence became cleaved off upon secretion. Direct contact between a cell presenting the transmembrane form of Jagged1 and a Notch‐expressing cell has been proposed as a prerequisite for the signaling event. However, the soluble form of Jagged1, when present in the cell culture medium, was sufficient to induce keratinocyte differentiation. These observations suggest a novel mechanism of how Jagged1 can target cells beyond the direct cell–cell contact in developing epithelia. © 2004 Wiley‐Liss, Inc.
Structural analysis of 2,6‐[bis(alkyloxy)methyl]‐phenyltin derivatives using electrospray ionization mass spectrometry
Authors: Kolářová Lenka , Holčapek Michal , Jambor Roman , Dostál Libor , Nádvorník Milan , Růžička Aleš
Published: June 2004

Electrospray ionization (ESI) mass spectrometry was applied to the structural analysis of 23 2,6‐[bis(alkyloxy)methyl]phenyltin(IV) derivatives. The mass spectra were measured in both polarity modes and multistage tandem mass spectrometric (MSn) measurements were performed on the ion trap analyser for positively charged tin‐containing ions. The sum of complementary ions observed in the positive‐ion mode (i.e. [M–R3]+ ion) and in the negative‐ion mode (i.e. [R3]− ion) permits molecular mass determination in spite of the fact that the molecular adducts were often missing even in the first‐order mass spectra. The subsequent fragmentation of [M–R3]+ ions studied by MSn and the correlation of observed fragment ions with the expected structures of synthesized organotin(IV) compounds allowed us to understand the fragmentation behaviour and the mechanism of the ion formation for studied compounds. The typical neutral losses are alkenes, alcohols and aldehydes. The fragmentation pattern of one selected compound was supported by MSn measurements of an isotopically labelled analogue to confirm unusual ion–molecule reactions of some fragment ions with water in the ion trap. Copyright © 2004 John Wiley & Sons, Ltd.
Interactions of Enzymes and a Lectin with a Chitin‐Based Graft Copolymer Having Polysarcosine Side Chains
Authors: Nakamura Rikiya , Aoi Keigo , Okada Masahiko
Published: June 2004

Summary: The molecular‐recognition abilities of a water‐soluble chitin derivative, chitin‐graft‐polysarcosine (2) were investigated using chitinase, lysozyme, and wheat germ agglutinin (WGA). The enzymatic degradabilities of 2 were evaluated using chitinase and lysozyme. The molecular weight of those compounds of 2 with a higher affinity toward water decreased rapidly, as compared with partially deacetylated chitin (1). The 1H NMR spectrum of the low‐molecular‐weight fraction, yielded after lysozymic hydrolysis, indicated that saccharide residues in the chitinous backbone were specifically recognized by the lysozyme, then β‐glycosidic linkages in the backbone were selectively hydrolyzed. Furthermore, the molecular‐recognition ability of the chitinous backbone of graft copolymer 2 toward the lectin WGA was elucidated by the enzyme‐linked lectin‐binding assay (ELLA). It was revealed that the graft copolymer with a lower degree of substitution (DS) value efficiently interacted with WGA. Interestingly, a graft copolymer having longer polysarcosine side chains showed higher recognition ability toward WGA than that having short side chains.

The structure of the graft copolymer, chitin‐graft‐polysarcosine 2, used here.

magnified image

The structure of the graft copolymer, chitin‐graft‐polysarcosine 2, used here.
Formation of in situ CB/PET Microfibers in CB/PET/PE Composites by Slit Die Extrusion and Hot Stretching
Authors: Xu Xiang‐Bin , Li Zhong‐Ming , Yu Run‐Ze , Lu Ai , Yang Ming‐Bo , Huang Rui
Published: June 2004

Summary: In this present study, the in situ fabrication of a microfibrillar composite based on poly(ethylene terephthalate) (PET), polyethylene (PE), and carbon black (CB) is attempted. PET and CB were first melt mixed. The CB/PET compound and PE were subsequently melt extruded through a slit die and then hot stretched. The morphological observation of the as‐stretched extrudate indicated that well‐defined microfibers of CB/PET compound could be generated at appropriate CB contents and a fixed hot stretch ratio. In addition, CB was always selectively located in PET. The microfibrillar CB/PET/PE composite has the potential to be a new electrically conductive polymer composite.

Morphology of the carbon black/poly(ethylene terephthalate)/polyethylene (PE) composite after additional mixing in the mixer at the processing temperature of PE.

magnified image

Morphology of the carbon black/poly(ethylene terephthalate)/polyethylene (PE) composite after additional mixing in the mixer at the processing temperature of PE.
Lp Decay problem for the dissipative wave equation in even dimensions
Authors: Ono Kosuke
Published: June 2004

We study Lp decay estimates of the solution to the Cauchy problem for the dissipative wave equation in even dimensions: (□+∂t)u=0 in ℝN × (0,∞) for even N=2n⩾2 with initial data (u,∂tu)∣t=0 =(u0,u1). The representation formulas of the solution u(t)=∂tS(t)u0 + S(t)(u0+u1) provide the sharp estimates on Lp norms with p⩾1. Copyright © 2004 John Wiley & Sons, Ltd.
Some non‐standard problems in viscous flow
Authors: Payne L. E. , Schaefer P. W. , Song J. C.
Published: June 2004

Energy bounds are derived for Dirichlet type boundary value problems for the Navier–Stokes and Stokes equations when a combination of the solution values initially and at a later time is prescribed. The bounds are obtained by means of a differential inequality and imply uniqueness and continuous data dependence of the solutions for a range of values of the parameter in the non‐standard auxiliary condition. Copyright © 2004 John Wiley & Sons, Ltd.
Electromagnetic periodic structure bandpass filter (EPS‐BPF) with two transmission zeros
Authors: Her Man‐Long , Chiou Yi‐Chyun , Wang Yu‐Zhen , Lin Kun‐Ying
Published: June 2004

In this paper, an improved electromagnetic periodic structure bandpass filter (EPS‐BPF) is designed and analyzed, and its equivalent circuit is also presented. The proposed structure achieves two transmission zeros on both sides of passband, while a good rolling skirt is obtained as well. The measured results show that the filter has a fractional 3‐dB bandwidth of 16%, and its insertion and return losses are −2 and −27 dB at the 5‐GHz center frequency, respectively. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 265–267, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20273
Modulation bandwidth of semiconductor lasers based on coupled quantum wells
Authors: Wartak M. S. , Weetman P.
Published: June 2004

The effect of well coupling on differential gain and maximum‐modulation bandwidth for semiconductor lasers based on coupled quantum wells is analyzed using the K‐factor method. We determine differential gain in coupled quantum wells within the self‐consistent solution of the Poisson, Schroedinger, and 4 × 4 Luttinger–Kohn equations. The multiple‐body effects of bandgap renormalization, coulombic scattering interactions, and a nonMarkovian distribution are also included. The analysis has been performed for coupled wells at 1.55 μm in an InGaAsP/InP lattice‐matched system grown in the [001] direction. Our results suggest that in order to maximize modulation bandwidth and differential gain, one should design structures with barrier widths larger than 40 Å. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 272–274, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20275
Design of an X‐band tray‐type spatial power combiner using uniplanar quasi‐Yagi antennas
Authors: Tsai Feng‐Chi E. , Bialkowski Marek E.
Published: June 2004

The design of an X‐band tray‐type spatial power combiner, which employs uniplanar quasi‐Yagi antennas (QYAs) for receiving and transmitting signals by individual amplifiers, is presented. Passive and active varieties of a seven‐tray power‐combining structure that includes two hard horns for uniform signal launching and combining across the tray stack are developed and measured. In order to compensate for nonuniform phase across the stack, which is caused by the nonplanar wave front of the horn antennas, Schiffman phase shifters are implemented in individual trays. The experimental results show an improved performance of the investigated tray‐type power combiner when the proposed phase‐error compensation is implemented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 307–311, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20287
New compact microstrip‐patch bandpass filter with two transmission zeros
Authors: Wang Xuedong , Zou Jie , Li Ying
Published: June 2004

This paper presents a new compact and simple microstrip‐patch bandpass filter structure using only one resonator. This filter has two transmission zeros on the both sides of the passband. The volume of this filter is about 1/3 or 1/2 of a conventional filter. Because the new filter is without coupling gaps, uncertainty during fabrication can be reduced. The effects of varying the parameters of the structure have been studied. The simulated results agree well with the measured results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 315–317, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20289
Design and analyses of compact bent‐tapered waveguides using guided‐wave lens sets
Authors: Chang Chun‐Wen , Hsieh Wen‐Feng
Published: June 2004

We propose compact bent‐tapered waveguides using guided‐wave lens sets, which are constructed by disposing lens‐shaped waveguide regions in planar tapered waveguides. Two applications of the abruptly bent tapered waveguide and the Z‐bend tapered waveguide demonstrate high transmittances of 91% and 86% with bent and tapered angles of 10°. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 324–328, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20292
Coplanar waveguide (CPW) defected ground structure (DGS) for bandpass filter application
Authors: Her Man‐Long , Wang Yu‐Zhen , Chang Chih‐Min , Lin Kun‐Ying
Published: June 2004

In this paper, we design and implement a coplanar waveguide (CPW) bandpass filter utilizing defected ground structure (DGS) technology. The CPW DGS technology, which only needs one or a series connection of a few cells to exhibit the bandgap characteristics, can provide the attenuation poles in the upper and lower bands to improve the rolloff characteristics of the bandpass filter. Moreover, the equivalent lump values of the CPW DGS are also calculated and good agreement between EM simulation and numerical calculation is obtained. The measured results show that the improved selectivity of upper and lower bands are 10.7 and 46.5 dB/GHz, respectively. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 331–334, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20294
Prediction of the reflection coefficient of shallow buried objects by a microwave technique
Authors: Furlan‐Achrait L. , Lasri T. , Mamouni A.
Published: June 2004

In this paper, we propose a low‐cost microwave technique to characterize shallow subsurface objects. Experiments and simulations are carried out to explore the possibility of predicting the reflection coefficient, according to one or two dimensions, of buried structures. High and low contrasts between the host medium and the object are investigated. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 335–339, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20295
Synthesis of alkaline‐developable, photosensitive hyperbranched polyimides through the reaction of carboxylic acid dianhydrides and trisamines
Authors: Makita Shohei , Kudo Hiroto , Nishikubo Tadatomi
Published: June 2004

Hyperbranched polyimides (HBPI)s with high glass‐transition temperatures and excellent thermal stability were synthesized through the reaction of commercially available carboxylic acid dianhydrides with tris[4‐(4‐aminophenoxy)phenyl]ethane (TAPE). In particular, hyperbranched polyimide HBPI(TAPE‐DSDA), prepared through the reaction of TAPE with 3,3′,4,4′‐diphenylsulfonetetracarboxylic dianhydride (DSDA), showed higher thermal stability and good solubility. Furthermore, alkaline‐developable, photosensitive HBPI(TAPE‐DSDA)‐MA‐CA was prepared through the reaction of HBPI(TAPE‐DSDA) with glycidyl methacrylate with tetrabutylammonium bromide as a catalyst in N‐methyl‐2‐pyrrolidinone (NMP) followed by the addition reaction of cis‐1,2,3,6‐tetrahydrophthalic anhydride with triphenylphosphine as a catalyst in NMP. The glass‐transition temperatures of HBPI(TAPE‐DSDA)‐MA‐CA were greater than 300 °C. A resist composed of 74 wt % HBPI(TAPE‐DSDA)‐MA‐CA, 22.2 wt % trimethylpropane triacrylate, and 3.8 wt % Irgacure 907 as a photoinitiator achieved a resolution of a 55‐μm line pattern and a 275‐μm space pattern by UV irradiation (1000 mJ/cm2). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3697–3707, 2004
On the Mechanism of Low Temperature Oxidation for Aluminum Particles down to the Nano‐Scale
Authors: Eisenreich Norbert , Fietzek Harald , del Mar Juez‐Lorenzo Maria , Kolarik Vladislav , Koleczko Andreas , Weiser Volker
Published: June 2004

The oxidation of Al‐particles down to nano‐scale was investigated by TG, SEM and in‐situ X‐ray diffraction. Al particles are usually coated by a 2–4 nm layer of Al2O3 which can be derived from the degree of weight increase on complete oxidation by TG‐curves. The low temperature oxidation of Al particles occurs at least in two steps. The first step builds a layer of 6 to 10 nm thickness composed of crystallites of the same size independent on the initial particle size. This reaction is dominated by chemical kinetics and converts a substantial fraction of the particle if the particle sizes decrease below 1 μm, an effect carefully to be taken into account for nano‐particles because of safety reasons. The second step combines diffusion and chemical reaction and proceeds therefore slowly, the slower the bigger the particles are. The kinetic parameters of these two steps can be obtained by a model taking into account both reaction steps, chemical kinetics and diffusion for spherical particles when fitting it to TG‐curves. X‐ray diffraction shows that particles smaller than 1 μm build γ‐ and θ‐Al2O3 in the first step with nano‐crystalline structures which are then transformed to α‐Al2O3.
X‐ray structure of a membrane‐bound β‐glycosidase from the hyperthermophilic archaeon Pyrococcus horikoshii
Authors: Akiba Toshihiko , Nishio Miho , Matsui Ikuo , Harata Kazuaki
Published: June 2004

The β‐glycosidase of the hyperthermophilic Archaeon Pyrococcus horikoshii is a membrane‐bound enzyme with the preferred substrate of alkyl‐β‐glycosides. In this study, the unusual structural features that confer the extreme thermostability and substrate preferences of this enzyme were investigated by X‐ray crystallography and docking simulation. The enzyme was crystallized in the presence of a neutral surfactant, and the crystal structure was solved by the molecular replacement method and refined at 2.5 Å. The main‐chain fold of the enzyme belongs to the (βα)8 barrel structure common to the Family 1 glycosyl hydrolases. The active site is located at the center of the C‐termini of the barrel β‐strands. The deep pocket of the active site accepts one sugar unit, and a hydrophobic channel extending radially from there binds the nonsugar moiety of the substrate. The docking simulation for oligosaccharides and alkylglucosides indicated that alkylglucosides with a long aliphatic chain are easily accommodated in the hydrophobic channel. This sparingly soluble enzyme has a cluster of hydrophobic residues on its surface, situated at the distal end of the active site channel and surrounded by a large patch of positively charged residues. We propose that this hydrophobic region can be inserted into the membrane while the surrounding positively charged residues make favorable contacts with phosphate groups on the inner surface of the membrane. The enzyme could thus adhere to the membrane in the proximity of its glycolipid substrate. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Rational proteomics II: Electrostatic nature of cofactor preference in the short‐chain oxidoreductase (SCOR) enzyme family
Authors: Pletnev Vladimir Z. , Weeks Charles M. , Duax William L.
Published: June 2004

The dominant role of long‐range electrostatic interatomic interactions in nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NAD/NADP) cofactor recognition has been shown for enzymes of the short‐chain oxidoreductase (SCOR) family. An estimation of cofactor preference based only on the contribution of the electrostatic energy term to the total energy of enzyme–cofactor interaction has been tested for ∼40 known three‐dimensional (3D) crystal complexes and ∼330 SCOR enzymes, with cofactor preference predicted by the presence of Asp or Arg recognition residues at specific 3D positions in the β2α3 loop (Duax et al., Proteins 2003;53:931–943). The results obtained were found to be consistent with ∼90% reliable cofactor assignments for those subsets. The procedure was then applied to ∼170 SCOR enzymes with completely uncertain NAD/NADP dependence, due to the lack of Asp and Arg marker residues. The proposed 3D electrostatic approach for cofactor assignment (“3D_ΔEel”) has been implemented in an automatic screening procedure, and together with the use of marker residues proposed earlier (Duax et al., Proteins 2003;53:931–943), increases the level of reliable predictions for the putative SCORs from ∼70% to ∼90%. It is expected to be applicable for any NAD/NADP‐dependent enzyme subset having at least 25–30% sequence identity, with at least one enzyme of known 3D crystal structure. Proteins 2004. © 2004 Wiley‐Liss, Inc.
Natural attenuation of chlorinated solvent plumes at Texas dry cleaners
Authors: Suarez Monica P. , Rifai Hanadi S. , Rittaler Tricia J. , Hausman Sarah
Published: June 2004

Dry cleaners are the largest users of perchloroethene (PCE) solvents in the United States. Releases from dry cleaners to soil and groundwater, however, remain largely unstudied. This article presents a database of 137 chlorinated solvent plumes at dry cleaners in Texas. The data indicate that PCE plumes are generally shorter in extent than those from industrial sites. Degradation products were observed at more than 80 percent of the sites with groundwater contamination. Calculated attenuation rates are on the order of one‐to‐three‐year half‐lives for PCE and its degradation products. The estimated cleanup timeframe for calculated attenuation rates is < 50 years. More research is needed to understand the presence of organic carbon sources at dry cleaners and its implications for natural attenuation. © 2004 Wiley Periodicals, Inc.
Application of the operating window concept to remediation‐option selection
Authors: Scott Duncan I. , Nathanail C. Paul
Published: June 2004

An Erratum has been published for this article in Remediation 14(4) 2004, 141.

The selection of remediation options for the management of unacceptable risks at contaminated sites is hindered by insufficient information on their performance under different site conditions. Therefore, there is a need to define “operating windows” for individual remediation options to summarize their performance under a variety of site conditions. The concept of the “operating window” has been applied as both a performance optimization tool and decision support tool in a number of different industries. Remediation‐option operating windows could be used as decision support tools during the “options appraisal” stage of the Model Procedures (CLR 11), proposed by the Environment Agency (EA) for England and Wales, to enhance the identification of “feasible remediation options” for “relevant pollutant linkages.” The development of remediation‐option operating windows involves: 1) the determination of relationships between site conditions (“critical variables”) and option performance parameters (e.g., contaminant degradation or removal rates) and 2) the identification of upper‐ and lower‐limit values (“operational limits”) for these variables that define the ranges of site conditions over which option performance is likely to be sufficient (the “operating window”) and insufficient (the “operating wall”) for managing risk. Some research has used case study data to determine relationships between critical variables and subsurface natural attenuation (NA) process rates. Despite the various challenges associated with the approach, these studies suggest that available case study data can be used to develop operating windows for monitored natural attenuation (MNA) and, indeed, other remediation options. It is envisaged that the development of remediation‐option operating windows will encourage the application of more innovative remediation options as opposed to excavation and disposal to landfill and/or on‐site containment, which remain the most commonly employed options in many countries. © 2004 Wiley Periodicals, Inc.
Electroremediation: A study of the influence of buffering behavior in contaminated soils
Authors: Hernández‐Luis Felipe , Lemus Mercedes , Grandoso Domingo , Vázquez Mario V. , Arbelo Carmen D.
Published: June 2004

This article presents the results of an experimental study conducted to evaluate the behavior of two types of andisol soils found in Tenerife, Canary Islands, Spain. The soils were evaluated in relation to their buffering capacity when confronted with acid and alkaline fronts generated during electroremediation treatment. The study was conducted using a cell, which established a continuous flow of distilled water through electrode chambers to remove H+ and OH− generated during electrolysis. The results indicate that the soils had sufficient buffer capacity to support variations in pH independent of the maintenance of flow of solution in the electrode chambers. Although the mechanism of migration was not affected, the flow of water favored the movement of ions by diffusion monitoring of the electrolytic current allowed for a real‐time parameter to act as an indicator of the quantity of ions available in regions near the electrodes. © 2004 Wiley Periodicals, Inc.
Salt and osmotic stress cause rapid increases in Arabidopsis thaliana cGMP levels
Authors: Donaldson Lara , Ludidi Ndiko , Knight Marc R , Gehring Chris , Denby Katherine
Published: June 2004

A guanylyl cyclase has been recently identified in Arabidopsis but, despite the use of pharmacological inhibitors to infer roles of the second messenger 3′,5′‐cyclic guanosine monophosphate (cGMP), very few measurements of actual cGMP levels in plants are available. Here, we demonstrate that cGMP levels in Arabidopsis seedlings increase rapidly (⩽5 s) and to different degrees after salt and osmotic stress, and that the increases are prevented by treatment with LY, an inhibitor of soluble guanylyl cyclases. In addition, we provide evidence to suggest that salt stress activates two cGMP signalling pathways – an osmotic, calcium‐independent pathway and an ionic, calcium‐dependent pathway.
An allozyme investigation of the stock structure of arrow squid Nototodarus gouldi (Cephalopoda: Ommastrephidae) from Australia
Authors: Triantafillos L , Jackson G.D , Adams M , McGrath Steer B.L
Published: June 2004

Allozyme electrophoresis was used to examine the stock structure of arrow squid Nototodarus gouldi (McCoy 1888) from Australia. Samples collected from six localities around southern Australia, separated by distances of between 700 and 4300 km, were examined for allozyme variation at 48 loci. The data revealed no evidence of more than a single species among the 203 squid examined. Nine polymorphic loci were detected, although only three were sufficiently variable to provide real insight into the population structure of arrow squid. There were no significant deviations from Hardy–Weinberg expectations for any locus, population, or for the metapopulation. Pairwise comparisons of allele frequencies revealed minor evidence of stock structure, with the Iluka (north New South Wales) sample set displaying significant allelic differences from the Tasmanian sample set at Acyc and from the Ulladulla (south New South Wales) sample set at Sordh. F-statistics also provided weak support that the Australian metapopulation is not panmictic. Further studies are needed to delineate the degree of stock segregation within the Australian/New Zealand region in order to successfully manage the arrow squid fishery in these waters.
Self-Esteem Within the Work and Organizational Context: A Review of the Organization-Based Self-Esteem Literature
Authors: Pierce Jon L. , Gardner Donald G.
Published: June 2004

On numerous occasions it has been suggested that an individual’s self-esteem, formed around work and organizational experiences, plays a significant role in determining employee motivation, work-related attitudes and behaviors. We review more than a decade of research on an organization-based conceptualization of self-esteem. It is observed that sources of organization structure, signals about worth from the organization, as well as, success-building role conditions predict organization-based self-esteem. In addition, organization-based self-esteem is related to job satisfaction, organizational commitment, motivation, citizenship behavior, in-role performance, and turnover intentions, as well as, other important organization-related attitudes and behaviors. Explanations for these effects and directions for future research are discussed.
Virtually Embedded Ties
Authors: Fowler Sally W. , Lawrence Thomas B. , Morse Eric A.
Published: June 2004

The Internet and other communication and information technologies have not only increased the efficiency and effectiveness of existing forms of interorganizational connection, but have also made possible the emergence of a new form – “virtually embedded ties”. Such ties have two essential features: first, they utilize electronic communication and information technologies; second, the use of those technologies allows them to overcome the exchange-related problems previously addressed through the formation of socially embedded ties. We argue that virtually embedded ties offer an important alternative to socially embedded ties in industries that are characterized by high levels of dynamism.
Empirical simulation studies in operations management: context, trends, and research opportunities
Authors: Shafer Scott M , Smunt Timothy L
Published: June 2004

This study investigates, published simulation studies in operations management (OM) that are empirically based. The results of the study are based on an exhaustive search of twenty leading operations management journals over the period from 1970 to 2000. Approximately, 600 published simulation studies in operations management were identified, but only 85 of these were subsequently identified as being empirical in nature. The 85 articles were next classified into one of 17 categories. Results by journal, topic, time period, and combinations of these factors are reported. Finally, opportunities for future research are discussed.
Oscillatory fluid flow affects human marrow stromal cell proliferation and differentiation
Authors: Li Ying Jun , Batra Nikhil N. , You Lidan , Meier Stephen C. , Coe Ian A. , Yellowley Clare E. , Jacobs Christopher R.
Published: June 2004

Mechanical loading is an important regulator of bone formation and bone loss. Decreased osteoblast number and function are important cellular mechanisms by which mechanical disuse leads to decreased bone formation. Decreased ostesed osteoblast number may be a result of decreased osteoprogenitor proliferation, differentiation, or both. However, the effects of cellular level physical signals on osteoprogenitors are not well understood. In this study, we examined the effects of loading induced oscillatory fluid flow (OFF), a potent regulator of osteoblastic cell function, on marrow stromal cells (MSCs). MSCs subjected to OFF exhibited increased intracellular Ca2+ mobilization. In addition, MSCs exhibited increased proliferation and increased mRNA levels for osteopontin and osteocalcin genes. Collagen I and core binding factor 1 mRNA levels did not change. MSCs subjected to OFF also exhibited decreased alkaline phosphatase activity. These results suggest that MSCs are mechanosensitive and that Ca2+ may play a role in the signaling pathway. © 2004 Orthopaedic Research Society. Published y Elsevier Ltd. All rights reserved.
Large global transient decreases of >70 MeV cosmic rays observed at Voyager 1 and Voyager 2 in the outer heliosphere in 2001–2003: The onset of heliospheric 2–3 kHz radio emission and the distance to the heliopause
Authors: Webber W. R. , Lockwood J. A.
Published: June 2004

We have used the onset of well‐defined large transient decreases of >70 MeV cosmic rays to mark the arrival of strong interplanetary shocks at the locations of Voyager 2 (V2) and Voyager 1 (V1) in the outer heliosphere. Several of the most prominent events in the time period from 1998 to 2003 are studied. The speed of these shocks shows a significant pattern of slowing down beyond the location of V2. These shocks exhibit average speeds of ∼550–600 km s−1 between the Earth and V2 located between 56 and 68 AU; but between V2 and V1, located ∼18 AU farther out, these average shock speeds appear to have decreased to ∼250–400 km s−1. This decreasing shock speed has important implications regarding the distance to the heliopause as inferred from the turn‐on of 2–3 kHz radio emission when these shocks reach this location. A new episode of this radio emission has now been observed by the Iowa group in late 2002, presumably related to strong solar activity occurring ∼570 days earlier in April 2001. The related transient decrease was seen in the >70 MeV cosmic ray data at V2, located at 65 AU, approximately 203 days after the event at the Earth, and at V1, located at 84 AU, approximately 135 days later. These times agree with those inferred from solar wind and magnetic field data. Using these times and a speed profile consistent with the observed slowing down between V2 and V1 puts the heliopause location at 115 ± 5 AU, which is near the inner limit of earlier estimates of its location but well inside the 151–158 AU inferred by the Iowa group for the new 2002 event. This difference is related to the slowing down of the interplanetary shock near the heliospheric termination shock that we find in this paper. Assuming a commonly accepted ratio of 0.75 for the heliospheric termination shock distance relative to the heliopause distance places the average termination shock location in the range ∼83–90 AU or at the distance of V1 between early 2002 and late 2003.