bluuebunny/crossref_metadata_2025 huggingface dataset:
Bayesian geoadditive modelling of breastfeeding initiation in Nigeria
Authors: Adebayo Samson B.
Published: April 2004

A study into the geographical variability of timing of initial child breastfeeding after birth was carried out with the data set from the 1999 Nigeria Demographic and Health Survey. The effect of the metrical covariate of the mother's age at birth was assumed to be nonlinear and estimated nonparametrically. Other categorical covariates are estimated in the usual parametric form. Within a Bayesian context, appropriate priors are assigned for the geographical location, vector of the unknown (nonlinear) smooth functions and a further vector of the fixed effect parameters. For instance, a Markov random field prior is assumed on the spatial effects. Inferences are based on Markov chain Monte Carlo techniques while Bayesian model diagnostics are based on the deviance information criteria. Copyright © 2004 John Wiley & Sons, Ltd.
Inhibition of apoptosis and caspase‐3 in vascular smooth muscle cells by plasminogen activator inhibitor type‐1
Authors: Chen Yabing , Kelm Robert J. , Budd Ralph C. , Sobel Burton E. , Schneider David J.
Published: April 2004

Increased expression of plasminogen activator inhibitor type 1 (PAI‐1) is associated with decreased apoptosis of neoplastic cells. We sought to determine whether PAI‐1 alters apoptosis in vascular smooth muscle cells (VSMC) and, if so, by what mechanisms. A twofold increase in the expression of PAI‐1 was induced in VSMC from transgenic mice with the use of the SM‐22α gene promoter (SM22‐PAI+). Cultured VSMC from SM22‐PAI+ mice were more resistant to apoptosis induced by tumor necrosis factor plus phorbol myristate acetate or palmitic acid compared with VSMC from negative control littermates. Both wild type (WT) and a stable active mutant form of PAI‐1 (Active) inhibited caspase‐3 amidolytic activity in cell lysates while a serpin‐defective mutant (Mut) PAI‐1 did not. Similarly, both WT and Active PAI‐1 decreased amidolytic activity of purified caspase‐3, whereas Mut PAI‐1 did not. WT but not Mut PAI‐1 decreased the cleavage of poly‐[ADP‐ribose]‐polymerase (PARP), the physiological substrate of caspase‐3. Noncovalent physical interaction between caspase‐3 and PAI‐1 was demonstrable with the use of both qualitative and quantitative in vitro binding assays. High affinity binding was eliminated by mutations that block PAI‐1 serpin activity. Accordingly, attenuated apoptosis resulting from elevated expression of PAI‐1 by VSMC may be attributable, at least in part, to reversible inhibition of caspase‐3 by active PAI‐1.
Even‐tempered slater‐type orbitals revisited: From hydrogen to krypton
Authors: Chong Delano P. , Van Lenthe Erik , Van Gisbergen Stan , Baerends Evert Jan
Published: March 2004

Even‐tempered Slater‐type orbital basis sets were developed in 1973, based on total atomic energy optimization. Here, we revisit ET STOs and propose new sets based on past experience and recent computational studies. From preliminary atomic and molecular tests, these sets are shown to be very well balanced and to perform, at lower cost, almost as well as a very large (close to complete) basis set. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1030–1036, 2004
Conformational energies for 2‐substituted butanes
Authors: Wiberg Kenneth B. , Wang Yi‐Gui
Published: March 2004

The conformational free energies for some 2‐substituted butanes where X = F, Cl, CN, and CCH were calculated using G3‐B3, CBS‐QB3, and CCSD(T)/6‐311++G(2d,p) as well as other theoretical levels. The above methods gave consistent results with free energies relative to the trans conformers as follows: X = CCH, g+ = 0.77 ± 0.05 kcal/mol. g− = 0.88 ± 0.05 kcal/mol; X = CN, g+ = 0.85 ± 0.05 kcal/mol, g− = 0.75 ± 0.05 kcal/mol; X = Cl, g+ = 0.70 ± 0.05 kcal/ml, g− = 0.80 ± 0.05 kcal/mol; and X = F, g+ = 0.53 ± 0.05 kcal/mol, g− = 0.83 ± 0.05 kcal/mol. The conformational free energies also were estimated using the observed liquid phase IR spectra and intensities calculated using B3LYP/6‐311++G** and MP2/6‐311++G**. The rotational free energy profiles for all of the compounds were estimated at the G3‐B3 level. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1127–1132, 2004
Cyclic k‐cycle systems of order 2kn + k: A solution of the last open cases
Authors: Vietri Andrea
Published: April 2004

We exhibit cyclic (Kv, Ck)‐designs with v > k, v ≡ k (mod 2k), for k an odd prime power but not a prime, and for k = 15. Such values were the only ones not to be analyzed yet, under the hypothesis v ≡ k (mod 2k). Our construction avails of Rosa sequences and approximates the Hamiltonian case (v = k), which is known to admit no cyclic design with the same values of k. As a particular consequence, we settle the existence question for cyclic (Kv, Ck)‐designs with k a prime power. © 2004 Wiley Periodicals, Inc. J Combin Designs 12: 299–310, 2004.
Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell lines
Authors: Holmes William F. , Soprano Dianne Robert , Soprano Kenneth J.
Published: April 2004

Apoptosis is also known as programmed cell death. Apoptosis plays an essential role in maintaining normal tissue and cell physiology in multicellular organisms. Clearance of aberrant or pre‐cancerous cells occurs through the induction of apoptosis. It has been reported that many tumors and tumor cell lines have dysfunctional apoptosis signaling, causing these tumors to escape immune monitoring and internal cellular control mechanisms. One potential cause of this dysfunctional apoptosis is the tumor suppressor p53, an important regulator of growth arrest and apoptosis that is mutated in over 50% of all cancers. Retinoids have great potential in the areas of cancer therapy and chemoprevention. While some tumor cells are sensitive to the growth inhibitory effects of natural retinoids such as all‐trans‐retinoic acid (ATRA), many ovarian tumor cells are not. 6‐[3‐(1‐Admantyl)]‐4‐hydroxyphenyl]‐2‐naphthalene carboxylic acid (CD437) and fenretinide N‐[4‐hydroxyphenyl] retinamide (4‐HPR) are conformationally restricted synthetic retinoids that induce growth arrest and apoptosis in both ATRA‐sensitive and ATRA‐resistant ovarian tumor cell lines. Recently, we have identified the molecular pathways of apoptosis induced by treatment of ovarian carcinoma cells with mutated p53 by CD437 and 4‐HPR. © 2004 Wiley‐Liss, Inc.
Fibroblast growth factor‐2 over‐rides insulin‐like growth factor‐I induced proliferation and cell survival in human neuroblastoma cells
Authors: Russo Vincenzo C. , Andaloro E. , Fornaro S.A. , Najdovska S. , Newgreen D.F. , Bach L.A. , Werther G.A.
Published: April 2004

The insulin‐like growth factor (IGF) system is a key regulator of cell growth, survival and differentiation, and these functions are co‐modulated by other growth factors including fibroblast growth factor‐2 (FGF‐2). To investigate IGF/FGF interactions in neuronal cells, we employed neuroblastoma cells (SK‐N‐MC). In serum free conditions proliferation of the SK‐N‐MC cells was promoted by IGF‐I (25 ng/ml), but blunted by FGF‐2 (50 ng/ml). IGF‐I‐induced proliferation was abolished in the presence of FGF‐2 even when IGF‐I was used at 100 ng/ml. In addition to our previously described FGF‐2 induced proteolytic cleavage of IGFBP‐2, we found that FGF‐2 increased IGFBP‐6 levels in conditioned medium (CM) without affecting IGFBP‐6 mRNA abundance. Modulation of IGFBP‐2 and ‐6 levels were not significant mechanisms involved in the blockade of IGF‐I action since the potent IGF‐I analogues [QAYL]IGF‐I and des(1–3)IGF‐I (minimal IGFBP affinity) were unable to overcome FGF‐2 inhibition of cell proliferation. FGF‐2 treated cells showed morphological differentiation expressing the TUJ1 neuronal marker while cells treated with IGF‐I alone showed no morphological change. When IGF‐I was combined with FGF‐2, however, cell morphology was indistinguishable from that seen with FGF‐2 alone. FGF‐2 inhibited proliferation and enhanced differentiation was also associated with a 70% increase in cell death. Although IGF‐I alone was potently anti‐apoptotic (60% decreased), IGF‐I was unable to prevent apoptosis when administrated in combination with FGF‐2. Gene‐array analysis confirmed FGF‐2 activation of the intrinsic and extrinsic apoptotic pathways and blockade of IGF anti‐apoptotic signaling. FGF‐2, directly and indirectly, overcomes the proliferative and anti‐apoptotic activity of IGF‐I by complex mechanisms, including enhancement of differentiation and apoptotic pathways, and inhibition of IGF‐I induced anti‐apoptotic signalling. Modulation of IGF binding protein abundance by FGF‐2 does not play a significant role in inhibition of IGF‐I induced mitogenesis. © 2003 Wiley‐Liss, Inc.
Control of human articular chondrocyte differentiation by reduced oxygen tension
Authors: Murphy Christopher L. , Polak Julia M.
Published: April 2004

Cell number is often a limiting factor in studies of chondrocyte physiology, particularly for human investigations. Chondrocytes can be readily proliferated in monolayer culture, however, differentiated phenotype is soon lost. We therefore endeavored to restore normal phenotype to human chondrocytes after serial passage in monolayer culture by manipulating cell morphology and oxygen tension towards the in vivo state. Third passage cells were encapsulated in alginate and exposed to either 20% or more physiologic 5% oxygen tensions. To assess cell phenotype, gene expression was measured using TaqMan real‐time PCR. Encapsulated, primary chondrocytes cultured in 20% oxygen were used as a positive reference. Passaged human chondrocytes were fibroblastic in appearance and had lost normal phenotype as evidenced by a decrease in expression of collagen II, aggrecan, and sox9 genes of 66, 6, and 14 fold, respectively; with concomitant high expression of type I collagen (22 fold increase). A partial regaining of the differentiated phenotype was observed by encapsulation in 20% oxygen; however, even after 4 weeks, collagen II gene expression was not fully restored. Collagen II and aggrecan expression were increased, on average, 3 fold, in 5% oxygen tension compared to 20% cultures. Furthermore, matrix glycosaminoglycan (GAG) levels were significantly increased in reduced oxygen. In fact, after 4 weeks in 5% oxygen, encapsulated third passage cells had collagen II expression fully regained and aggrecan and sox9 levels actually exceeding primary cell levels in 20% oxygen. Our results show that the phenotype of serially passaged human articular chondrocytes is more fully restored by combining encapsulation with culture in more physiological levels of oxygen. Sox9, an essential transcription factor for chondrocyte differentiation is strongly implicated in this process since its expression was upregulated almost 27 fold. These findings have implications for the optimal conditions for the in vitro culture of chondrocytes. © 2004 Wiley‐Liss, Inc.
Initial interactions in electromagnetic field‐induced biosynthesis
Authors: Blank Martin , Goodman Reba
Published: April 2004

Low frequency electromagnetic (EM) fields induce gene expression, and recent insights into physical interactions of EM fields with model systems suggest a mechanism that could initiate this process. The consistently low thresholds at which EM fields stimulate biological processes indicate that they require little energy. Since it has been shown that such weak fields accelerate electron transfer reactions, they could stimulate transcription by interacting with electrons in DNA to destabilize the H‐bonds holding the two DNA strands together. Such a mechanism is consistent with the low electron affinity of the bases in previously identified electromagnetic response elements (EMREs) needed for EM field interaction with DNA. It is also in line with both endogenous and in vitro stimulation of biosynthesis by electric fields. The frequency response of several EM sensitive biological systems suggests that EM fields require repetition and are most effective at frequencies that coincide with natural rhythms of the processes affected. © 2004 Wiley‐Liss, Inc.
Differential signalling of purinoceptors in HeLa cells through the extracellular signal‐regulated kinase and protein kinase C pathways
Authors: Muscella Antonella , Greco Simona , Elia Maria Giovanna , Storelli Carlo , Marsigliante Santo
Published: April 2004

We have previously shown that HeLa cells express P2Y2 and P2Y6 receptors endogenously and determined the pathways by which the P2Y2 controls proliferation and Na+/K+ATPase activity. Our objective in this study was to investigate the hypothesis that P2Y6 also controls proliferation and Na+/K+ATPase activity; the pathways used in these actions were partially characterised. We found that P2Y6 activation controlled cell proliferation but not the activity of the Na+/K+ATPase. UDP activation of P2Y6 provoked: (a) an increase in free cytosolic calcium; (b) the activation of protein kinase C‐α, ‐β, ‐δ, ‐ε, and ‐ζ but not of PKC‐ι and ‐η; (c) the phosphorylation of the extracellular signal‐regulated protein kinases 1 and 2 (ERK1/2); (d) the expression of c‐Fos protein. The P2Y6‐induced cell proliferation was blocked by the mitogen‐activated protein kinase kinase (MAPKK) inhibitor PD098059, thereby indicating that the ERK pathway mediates the mitogenic signalling of P2Y6. PKC and phosphoinositide 3‐kinase (PI3K) inhibitors were tested at two different time points of ERK1/2 phosphorylation (10 and 60 min). The results suggest that novel PKCs and PI3K initiate the response but both conventional and atypical PKCs are required for the maintenance of the UDP‐induced phosphorylation of ERK1/2. The induction of c‐Fos was greatly diminished by conventional or atypical PKC‐ζ inhibition, suggesting that it may be due to PKC‐α/β and ‐ζ activity. These observations demonstrate that UDP acts as a proliferative agent in HeLa cells activating multiple signalling pathways involving conventional, novel, and atypical PKCs, PI3K, and ERK. Of these pathways, conventional and atypical PKCs appear responsible for the induction of c‐Fos, while ERK is responsible for cell proliferation and depends upon both novel and atypical PKCs and PI3K activities. © 2004 Wiley‐Liss, Inc.
Apotransferrin is internalized and distributed in the same way as holotransferrin in K562 cells
Authors: Xiu‐lian Du , Kui Wang , Ya Ke , Lan Yuan , Rong‐chang Li , Yan Zhong Chang , Kwok Ping Ho , Zhong Ming Qian
Published: April 2004

Transferrin (Tf), a naturally existing protein, has received considerable attention in the area of drug targeting since it is biodegradable, non‐toxic, and non‐immunogenic. The efficient cellular uptake of Tf shows it has potential in the delivery of anti‐cancer drugs, proteins, and therapeutic genes into proliferating malignant cells that overexpress transferrin receptor (TfR). In human serum, about 30% of Tf exists in the iron‐saturated form (Fe2‐Tf) and the remainder exists as apotransferrin (apo‐Tf). Understanding the uptake of apo‐Tf by cells will provide key insights into studies on Tf‐mediated drug delivery. In the present study, we investigated visually the transport of apo‐Tf into K562 cells and its intracellular localization by laser‐scanning confocal microscopy (LSCM) and flow cytometry analysis (FCA). It was found that, like Fe2‐Tf, apo‐Tf can be taken up into the cells. The process is time‐ and temperature‐dependent, competitively inhibited by Fe2‐Tf, and significantly abolished by pronase pretreatment. Visual evidence showed that the transport of apo‐Tf into K562 cells is a TfR‐mediated process. Furthermore, the investigations using optical‐slicing technique demonstrated that the distribution of apo‐Tf is similar to that of Fe2‐Tf, both appearing in the perinuclear region in ball‐in‐bowl shape. J. Cell. Physiol. 201: 45–54, 2004. © 2004 Wiley‐Liss, Inc.
New lower bounds for the size of edge chromatic critical graphs
Authors: Zhao Yue
Published: April 2004

In this paper, by applying the discharging method, we obtain new lower bounds for the size of edge chromatic critical graphs for small maximum degree Δ. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 81–92, 2004
Some probabilistic restatements of the Four Color Conjecture
Authors: Matiyasevich Yuri
Published: April 2004

With every triangulation of sphere, we associate a probabilistic space in a natural way and define several random events. The Four Color Conjecture (4CC) turns out to be equivalent to different statements about positive correlation among some pairs of these events. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 167–179, 2004
A note on a conjecture about cycles with many incident chords
Authors: Jiang Tao
Published: April 2004

Given positive integers n and k, let gk(n) denote the maximum number of edges of a graph on n vertices that does not contain a cycle with k chords incident to a vertex on the cycle. Bollobás conjectured as an exercise in [2, p. 398, Problem 13] that there exists a function n(k) such that gk(n) = (k + 1)n − (k + 1)2 for all n ≥ n(k). Using an old result of Bondy [3], we prove the conjecture, showing that n(k) ≤ 3 k + 3. © 2004 Wiley Periodicals, Inc. J Graph Theory 46: 180–182, 2004
Swim bladder and posterior lateral line nerve of the nurseryfish, Kurtus gulliveri (Perciformes: Kurtidae)
Authors: Carpenter Kent E. , Berra Tim M. , Humphries Julian M.
Published: March 2004

The morphology of the swim bladder and inner ear of the nurseryfish, Kurtus gulliveri, appear adapted for enhanced pressure wave reception. The saccule is enlarged and surrounded by very thin bone and two large fontanelles that would present reduced resistance to pressure waves. The swim bladder is elaborate, with six dorsolaterally projecting pairs of lobes that are tightly encased in ribs and an additional caudally projecting pair of lobes encased in the first hemal spine. The ribs and musculature surrounding the swim bladder laterally are very thin, so that four or five “rib windows” are readily apparent on back‐lit specimens. This swim bladder–rib configuration would also present reduced resistance to pressure waves to enhance function as a peripheral auditory structure. However, high‐resolution X‐ray computed tomography and dissection reveal no anterior projections of the swim bladder that could serve as a mechanical coupling to the inner ear. The posterior lateral line nerve is well developed and lies directly over the tips of the ribs encasing the swim bladder lobes. This nerve is not, however, associated with a lateral line canal and a lateral line canal is absent on most of the body. We hypothesize that the posterior lateral line nerve transmits mechanosensory information from the swim bladder. J. Morphol. 260:193–200, 2004. © 2004 Wiley‐Liss, Inc.
Location of the ureteral openings in the cloacas of tinamous, some ratite birds, and crocodilians: A primitive character
Authors: Oliveira Cleida Aparecida , Silva Renata Mageste , Santos Marcileida Maria , Mahecha Germán Arturo Bohórquez
Published: March 2004

Cloacas of 67 avian species, of both sexes, from various habitats and differing dietary habits, were examined macro‐ and microscopically to investigate possible variation in the location of the ureteral openings. Differing from most birds studied, in adult male Rhea americana and several tinamous species the ureters were found to open into the coprodeum. In these species the urodeum receives only the vas deferens or oviduct. Similarly, in crocodiles Caiman crocodilus yacare, but not in lizards Tropidurus montanus and snakes Crotalus durissus terrificus, the ureters empty into the coprodeum. This similarity between ancient birds (ratites and tinamous) and crocodiles may indicate a primitive character linking reptiles and birds. This unusual position of the ureteral orifice can represent an adaptation to facilitate urine collection into the coprodeum and large intestine. Another possibility is that this variation in ureter position is a male reproductive strategy to avoid the mixture of urine and semen in the cloaca. There were no evident correlations between the location of the ureteral openings and the birds' habitat, diet, or histology of the coprodeal mucosa. The occurrence of a phallus in eight species of birds was detected, as well as a peculiar vascularization related to the coprodeal epithelium of anseriformes. Together, these data add to the scarce information about the morphophysiology of the avian cloaca, and also contribute to clarify avian phylogenetic linkages. J. Morphol. 260:234–246, 2004. © 2004 Wiley‐Liss, Inc.
Towards Green Routes for Polymer Synthesis: Polymerization of Cyclodextrin Host‐Guest Complexed Diethyl Fumarate and Copolymerization with Complexed Styrene in Homogenous Aqueous Solution
Authors: Choi Soo‐Whan , Ritter Helmut
Published: April 2004

Summary: The radical homo‐ and copolymerization of styrene (1) and diethyl fumarate (DEF, 2) in the presence of methylated β‐cyclodextrin (β‐CD) in water is described. It has been shown for the first time that homopolymerization of CD‐complexed DEF and its copolymerization with CD‐complexed styrene occur readily in aqueous solution. In the absence of CD, or in organic solvents, the homopolymerization of DEF is strongly retarded.

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The Association of Tetraalkylammonium Ions with Poly(vinyl methyl ether) in Water and its Effect on Phase‐Separation Behavior as Studied by Micro‐Raman Spectroscopy
Authors: Maeda Yasushi , Yamamoto Hiroki , Ikeda Isao
Published: April 2004

Summary: The thermosensitive phase‐separation of poly(vinyl methyl ether) in water has been investigated by micro‐Raman spectroscopy in the presence of tetraalkylammonium bromides. The equilibrium distribution of both polymer and salts to the polymer‐rich and solvent‐rich phases was determined as a function of temperature. Tetraalkylammonium ions with longer alkyl chains associate more strongly with PVME and raise the phase‐transition temperature due to an increase in hydrophilicity.

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An Ordered Nanoporous Monolith from an Elastomeric Crosslinked Block Copolymer Precursor
Authors: Cavicchi Kevin A. , Zalusky Andrew S. , Hillmyer Marc A. , Lodge Timothy P.
Published: April 2004

Summary: An ordered nanoporous monolith was prepared from a poly(isoprene‐b‐dimethylsiloxane) (PI‐PDMS) hexagonally packed cylinder precursor. The PDMS cylinders were macroscopically aligned, the PI was crosslinked with dicumyl peroxide, and the PDMS was removed using tetrabutylammonium fluoride. The stability of the pores depended on the modulus of the matrix. At high crosslink density the pores were stable, but they collapsed at a low crosslink density. The nanoporous materials could be swollen in toluene.

A scanning electron micrograph of the end‐on view of crosslinked degraded poly(isoprene‐b‐dimethylsiloxane).

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A scanning electron micrograph of the end‐on view of crosslinked degraded poly(isoprene‐b‐dimethylsiloxane).
Cover Picture: Macromol. Rapid Commun. 6/2004
Authors: Hittinger Eric , Kokil Akshay , Weder Christoph
Published: April 2004

Cover: The cover picture shows the schematic and detailed chemical structure of a cross‐linked conjugated poly(p‐phenylene ethynylene), together with a picture of a gel based on this highly fluorescent material. Cross‐linked conjugated polymers exhibit potentially interesting optoelectronic properties and can be processed into films and other shapes by simultaneous polymerization and object forming.

Further details can be found in the Communication by E. Hittinger, A. Kokil, and C. Weder* on page 710.
Magnetic resonance imaging and single‐photon emission computed tomography changes in hypoglycemia‐induced chorea
Authors: Lai Shung‐Lon , Tseng Yu‐Lung , Hsu Ming‐Chin , Chen Shun‐Sheng
Published: April 2004

We present two case studies, one of generalized chorea and one of hemichorea, both after severe hypoglycemia episodes. Both cases showed hyperperfusion in their SPECT scans. The MRI and SPECT findings serve as clues regarding the role of basal ganglion dysfunction associated with chorea. © 2003 Movement Disorder Society
Is the rhythm of physiological tremor involved in cortico‐cortical interactions?
Authors: Raethjen Jan , Lindemann Michael , Morsnowski Andre , Dümpelmann Matthias , Wenzelburger Roland , Stolze Henning , Fietzek Urban , Pfister Gerd , Elger Christian E. , Timmer Jens , Deuschl Günther
Published: April 2004

The function of low‐frequency oscillations as correlates of physiological tremor in supplementary motor area (SMA) and M1 remains unclear. In epicortical recordings from M1 and SMA and surface electromyographic (EMG) recordings in an epileptic patient we found reproducibly significant coherence between all three recording sites in the 6‐ to 15‐Hz band. The partial coherence between SMA and muscle, however, was not significant. There was a constant phase shift between SMA and M1 indicating synchronized activity. We conclude that the cortical correlates of physiological tremor may be involved in linking different cortical motor centers and might therefore play a role in cortical motor planning. © 2003 Movement Disorder Society
Choreic syndrome and coeliac disease: A hitherto unrecognised association
Authors: Pereira Anthony C. , Edwards Mark J. , Buttery Philip C. , Hawkes Christopher H. , Quinn Niall P. , Giovannoni Gavin , Hadjivassiliou Marios , Bhatia Kailash P.
Published: April 2004

Coeliac disease has been associated with a variety of neurological conditions, most frequently cerebellar ataxia and peripheral neuropathy. To date, chorea has not been associated with coeliac disease. We present the case histories of 4 individuals with coeliac disease and chorea (4 women, average age of onset of chorea 61 years). Unexpectedly, most of these patients showed a notable improvement in their motor symptoms after the introduction of a gluten‐free diet. © 2003 Movement Disorder Society
Association of cortical disinhibition with tic, ADHD, and OCD severity in Tourette syndrome
Authors: Gilbert Donald L. , Bansal Alok S. , Sethuraman Gopalan , Sallee Floyd R. , Zhang Jie , Lipps Tara , Wassermann Eric M.
Published: April 2004

Hyperkinetic disorders may involve excess excitatory output from thalamus to cerebral cortex. Case–control, neurophysiological studies in persons with Tourette Syndrome (TS), Attention Deficit Hyperactivity Disorder (ADHD), and Obsessive‐Compulsive Disorder (OCD) support this model. To compare the strength of association between motor cortex inhibition and tic, ADHD, and OCD severity in TS, we used transcranial magnetic stimulation to measure motor cortex inhibition in 36 children and adults with TS. Current symptom severity was assessed with standard clinical rating scales and compared with neurophysiological measures using correlational and multivariate regression analyses. Severity of ADHD symptoms and motor tics were associated significantly and independently with short interval intracortical inhibition (SICI) (r2 = 0.50; F[2,27] = 13.7; P < 0.001), particularly in subjects not taking neuroleptics (r2 = 0.68; F[2,17] = 17.8; P < 0.0001). The correlation of cortical disinhibition was greater with ADHD symptoms severity (r = 0.53; P = 0.003) than with tic severity (r = 0.42; P = 0.02), suggesting that in TS, the association between SICI and ADHD symptoms may be more consistent or direct than the association between SICI and tics. © 2004 Movement Disorder Society
Anti‐basal ganglia antibodies in PANDAS
Authors: Singer Harvey S. , Loiselle Christopher R. , Lee Olivia , Minzer Karen , Swedo Susan , Grus Franz H.
Published: April 2004

An autoimmune‐mediated mechanism involving molecular mimicry has been proposed for a variety of pediatric movement disorders that occur after a streptococcal infection. In this study, anti‐basal ganglia antibodies (ABGA) were measured in 15 children with the diagnosis of pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS) and compared with those in 15 controls. ELISA and Western immunoblotting (WB) methods were used to detect ABGA against supernatant (S1), pellet (P2), and synaptosomal preparations from adult postmortem caudate, putamen, and globus pallidus. ELISA optical density values did not differ between PANDAS patients and controls across all preparations. Immunoblotting identified multiple bands in all subjects with no differences in the number of bands or their total density. Discriminant analysis, used to assess mean binding patterns, showed that PANDAS patients differed from controls only for the caudate S1 fraction (Wilks' λ = 0.0236, P < 0.0002), with PANDAS‐primarily tic subjects providing the greatest discrimination. Among the epitopes contributing to differences between PANDAS and control in the caudate S1 fraction, mean binding to the epitope at 183 kDa was the most different between groups. In conclusion, ELISA measurements do not differentiate between PANDAS and controls, suggesting a lack of major antibody changes in this disorder. Further immunoblot analyses using a caudate supernatant fraction are required to completely exclude the possibility of minor antibody repertoire differences in PANDAS subjects, especially in those who primarily have tics. © 2004 Movement Disorder Society
Does parkin play a role in the peripheral nervous system? A family report
Authors: Abbruzzese Giovanni , Pigullo Simona , Schenone Angelo , Bellone Emilia , Marchese Roberta , Di Maria Emilio , Benedetti Luana , Ciotti Paola , Nobbio Lucilla , Bonifati Vincenzo , Ajmar Franco , Mandich Paola
Published: April 2004

Two genes were identified for autosomal recessive forms of early onset Parkinson's disease: parkin and DJ‐1. We describe 2 siblings with EOPD due to parkin mutations and peripheral neuropathy, which presented as neuropathy with liability to pressure palsies (HNPP) in the index case. RT‐PCR experiments revealed that the parkin gene is expressed in sural nerves from both controls and patient with parkin‐related disease. Our findings support the view that parkin may play a role in the peripheral nervous system. © 2004 Movement Disorder Society
Ultra‐wideband TEM horn design for ground penetrating impulse radar systems
Authors: Turk Ahmet Serdar
Published: April 2004

The partial dielectric‐loaded TEM horn (PDTEM) structure, which maintains ultra‐wideband antenna characteristics over a bandwidth ratio greater than 20:1 in order to improve the impulse‐radiation characteristics for ground penetrating radar systems is described in this paper. It is shown that high‐gain and low‐input‐reflection levels over the operational band are attainable for TEM horns with proper dielectric, absorber, and resistive loadings. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 333–336, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20133
Experimental characteristics of a printed open‐slot antenna with reflector for PCS, DCS, and IMT‐2000
Authors: Jang Yong‐Woong
Published: April 2004

In this paper, we investigate a new rectangular‐fed printed open‐slot antenna (POSA) with reflector, which has the advantages of improved radiation‐pattern properties along with broad‐bandwidth characteristics. The measured bandwidth of the proposed POSA with reflector is approximately 47.6% (−10 dB ≥ S11), thus, it can be used for PCS, DCS, and IMT‐2000. But the measured bandwidth of the PCSA with reflector is approximately 46% (with VSWR ≤ 2.0). The tilt angle at maximum gain is enhanced by using a modified POSA with reflector for practical applications. The radiation pattern null and distortion of the open‐slot antenna exhibited better performances than those of the closed‐slot antenna. The back‐lobe level of the POSA with reflector also presented much better results than the PCSA with reflector. The proposed antenna obtained not only wider bandwidth but also better radiation patterns characteristics than the PCSA with reflector. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 348–350, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20138
Wave scattering with UV multilevel partitioning method for volume scattering by discrete scatterers
Authors: Tsang L. , Li Qin
Published: April 2004

A UV multilevel partitioning method (UV‐MLP) is developed to solve the volume‐scattering problem. The method involves creating a rank table of transmitting and receiving block sizes and their separation. The table can be set up speedily using coarse‐coarse sampling. For a specific scattering problem with given geometry, the scattering structure is partitioned into multilevel blocks. By looking up the rank in the predetermined table, the impedance matrix for a given transmitting and receiving block is expressed as a product of U and V matrices. We illustrate the method for 2D volume scattering by discrete scatterers. Multiple scattering is cast into the Foldy–Lax equations of partial waves. We show that UV decomposition can be applied directly to the impedance matrix of partial waves of higher order than the usual lowest‐order Green's function. Numerical results are illustrated for randomly distributed cylinders that are one wavelength in diameter. For scattering by 1024 cylinders on a single PC processor with a 2.6‐GHz CPU and 2‐GB memory, only 14 CPU min are required to obtain the numerical solution. If subsectional volumetric discretization with the method of moments (MoM) is applied to this problem, the equivalent number of volumetric unknowns is 80,425. Furthermore, for 4096 cylinders that have 321,700 equivalent numbers of volumetric unknowns, it takes only 7.34 sec for one matrix‐vector multiplication. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 354–361, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20140
A novel monopole antenna with broad bandwidth
Authors: Wang Hongyu , Ruan Chenglu , Wang Qi
Published: April 2004

A novel monopole antenna with two parasitic elements added is presented for broadband applications. The impedance and radiation characteristics of the antenna are investigated experimentally and numerically. For the proposed antenna, a bandwidth of 97.1% with |S11| < −10 dB is achieved, and omnidirectional radiation pattern is obtained. The results are very attractive for mobile‐communication systems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 364–366, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20142
A planar meander‐line antenna for triple‐band operation of mobile handsets
Authors: Wu Jeun‐Wen , Lin Chun‐Ren , Lu Jui‐Han
Published: April 2004

A planar meander‐line antenna consisting of three branch strips for very‐low‐profile GSM/DCS/PCS/WLAN triple‐band operation of mobile phones is presented. The branch strips are designed to operate as quarter‐wavelength structures at 900 and 1800 MHz, respectively, and the obtained impedance bandwidths cover the required bandwidths of the GSM (890–960 MHz), DCS/PCS (1710–1880/1850–1990 MHz), and WLAN (2400–2484 MHz) bands. The proposed antenna is 46.5 mm in width and 11 mm in height, and can be mounted on top of a mobile phone with a small distance of 2 mm to the ground plane, thus resulting in a very low profile of 13 mm (less than 4% of the wavelength at 900 MHz) from the ground plane for the proposed antenna in practical applications. The measured antenna‐radiation patterns are approximately omnidirectional at the three resonant frequencies. Peak antenna gains for operating frequencies across the GSM/DCS/PCS/WLAN triple bands are measured to be 1.1, 1.6, and 1.2 dBi, respectively, with gain variations within 0.5 dBi. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 380–386, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20146
Analytical analysis of a rectangular shielded multilayer coupled coplanar waveguide
Authors: Shan Zhiyong , Zhang Yanhua , Zhou Xilang , Yao Ji
Published: April 2004

The closed‐form expressions for calculating the quasi‐static parameters of a rectangular shielded multilayer coupled coplanar waveguide (RSMCCPW) are presented. Expressions of the odd‐ and even‐mode characteristic impedances, which can provide accurate and fast calculations, are derived by using conformal‐mapping techniques. The numerical results are obtained and compared with those available in the literature for similar unshielded structures. Good agreement between the results is observed. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 392–395, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20149
A low‐profile broadband 16‐mm‐diameter post‐type monopole antenna ceiling‐mounted in a building
Authors: Jang Yong‐Woong , Go Hyun‐Chull
Published: April 2004

This paper experimentally presents a low‐profile broadband post‐type monopole antenna. The characteristics of the antenna are highly dependent on the design parameters (Rm, hm, hfl, and Rg). Instead of a wire monopole, the proposed antenna is made of a 16‐mm‐diameter aluminum post that is ceiling‐mounted in a building. This is due to the low‐radiation resistance in the usable band. The post‐type element is used to enhance the impedance matching. The experimental impedance bandwidth obtained is approximately 67.9% (1.9824–3.5534 GHz) for a VSWR of less than 2.0. The impedance bandwidth covers multiband operations for mobile and satellite communication. We also present the measured radiation patterns and gain characteristics of the proposed antenna. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 395–397, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20150
High‐gain broadband patch antenna with a cavity ground for 5‐GHz WLAN operation
Authors: Su Saou‐Wen , Wong Kin‐Lu , Cheng Yuan‐Tung , Chen Wen‐Shyang
Published: April 2004

A novel broadband patch antenna with an equilateral‐triangular cavity ground for achieving enhanced antenna gain over a large bandwidth is presented. A constructed prototype covering the 5.2/5.8‐GHz (5150–5350/5725–5875 GHz) WLAN bands and showing a high antenna‐gain level of about 9.8 dBi is demonstrated. Across the operating band, the prototype also shows good radiation characteristics with reduced cross‐polarization and backward radiation. Details of the proposed antenna design and obtained experimental results are presented. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 397–399, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20151
Efficient analysis of L‐probe coupled patch antenna arrays mounted on a finite conducting cylinder
Authors: Cao Xiangyu , Li Pei , Luk K. M. , Liang Changhong , Gao Jun
Published: April 2004

The radiation pattern of an L‐probe coupled patch‐antenna array mounted on a finite conducting cylinder is accurately and efficiently computed by the electric‐field integral equation (EFIE) in conjunction with the method of moments (MoM) and Galerkin's testing procedure. The effects of different dimensions of the cylinder on the radiation characteristics are studied, including beamwidth, sidelobe, and backlobe. The results are useful for designing wideband smart‐antenna arrays for future mobile‐communication systems. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 403–407, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20153
Analysis of Raman amplifiers' transient effects and TDM‐pumped Raman amplifiers using the finite‐difference method
Authors: Wei Huai , Tong Zhi , Wang Muguang , Jian Shuisheng
Published: April 2004

We propose a novel method to analyze Raman amplifiers (RAs) by solving difference equations. This method is highly convenient for analysis of the transient effects of Raman amplifiers under dynamic conditions. Some properties of time‐division multiplexing (TDM)‐pumped RAs are analyzed theoretically. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 407–410, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20154
Novel combined MOD‐P multiband antenna structures inspired by fractal geometries
Authors: Soler Jordi , Garcia Daniel , Puente Carles , Anguera Jaume
Published: April 2004

A novel set of multiband antenna structures, which combine different geometries based on fractal elements, are presented. The new combined radiating elements profit from the multifrequency properties of the noncombined geometries, thus providing a mechanism to adjust the antenna parameters. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 41: 423–426, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20159
Hydrogenation of aldehydes catalyzed by kieselguhr‐supported carboxymethylcellulose‐nickel complex
Authors: Zhou De‐Jun , Zhou Da‐Qing , Cui Xiao‐Hua , Wang Fu‐Ming , Huang Mei‐Yu , Jiang Ying‐Yan
Published: April 2004

A new kieselguhr‐supported carboxymethylcellulose‐nickel complex (Kie‐CMC‐Ni) has been prepared by a simple method, which has been found to catalyze the hydrogenation of benzaldehyde, valeraldehyde and isobutyraldehyde to the corresponding alcohols in high yield (100, 92 and 86% respectively). The catalyst could be reused without obvious loss of its catalytic activity. Copyright © 2004 John Wiley & Sons, Ltd.
1,3,2‐Dioxaborines as potential components in advanced materials—a theoretical study on electron affinity
Authors: Fabian Jürgen , Hartmann Horst
Published: April 2004

1,3,2‐Dioxaborines with fluorine and other substituents at boron were calculated by first‐principles methods based on density functional theory (DFT: B3‐LYP) or many‐body perturbation theory at the second order [MBPT(2): MP2]. 1,3,2‐Dioxaborines are derivatives of 1,3‐dicarbonyl compounds also known as 1,3‐diketoborates. According to quantum chemical calculations, 2,2‐difluoro‐1,3,2‐dioxaborines are of puckered structure with a low barrier to inversion. The calculated charge distribution does not reflect well the traditional formula description. The boron atom carries a positive rather than a negative charge. Some compounds have a pronounced zwitterionic character accompanied by relatively high dipole moments. The calculated positive electron affinities (EAs) classify 1,3,2‐dioxaborines as organic electron‐acceptor compounds. Depending on the type of substitution, the EAs vary between about 0.5 and 3.5 eV (DFT calculations). The EAs of various substituted 1,3,2‐dioxaborines are of the same order of magnitude as those of quinones and close to electron affinities of strong organic acceptor compounds such as tetracyanoethylene (TCNE). Numerical predictions are verified by comparison with EAs of a series of well‐known medium‐sized organic compounds studied experimentally and theoretically at the same level of theory. In good agreement with results reported for other series of compounds, the average absolute error between theoretical and experimental EAs was 0.19 eV. Because of the ability of 3,5‐diaryl‐2,2‐difluoro‐1,3,2‐dioxaboranes to fluoresce efficiently and to accept electrons easily, these compounds are potential candidates for future applications. Copyright © 2004 John Wiley & Sons, Ltd.
Effects of non‐ionic and mixed non‐ionic–cationic micelles on the rate of aqueous cleavages of phenyl benzoate and phenyl salicylate in alkaline medium
Authors: Khan M. Niyaz , Ismail Emran
Published: April 2004

Pseudo‐first‐order rate constants (kobs) for the hydrolysis of phenyl salicylate (PSH) and phenyl benzoate (PB) in the alkaline medium show a monotonic decrease with the increase in [C16E20]T (total concentration of Brij 58) at constant [CH3CN] and [NaOH]. This micellar effect is explained in terms of the pseudophase model of micelles. These results show a characteristic difference between the effects of [C16E20]T and previously published effects of [C12E23]T (total concentration of Brij 35) on the rates of aqueous cleavage of PSH and PB at [CnEm]T/[NaOH]≥∼3. The values of kobs, obtained at different [C16E20]T in the presence of a constant amount of CTABr, follow the empirical relationship kobs=(k0+θK[C16E20]T)/(1+K[C16E20]T), where θ and K are empirical parameters. The values of θ are not affected whereas the values of K decrease with increase in [CTABr]T in a mixed C16E20–CTABr micellar system. The values of θ at different [CTABr]T show that θ>k0 for hydrolysis of PSH and θ<k0 for hydrolysis of PB in the presence of 0.01 M NaOH. The effects of [CTABr]T on K and θ are explained in terms of the pseudophase model of micelles coupled with the empirical relationship KS=KS0/(1+KC16E20/S[C16E20]T). Copyright © 2004 John Wiley & Sons, Ltd.
Racemization and hydrolysis of (S)‐naproxen 2,2,2‐trifluoroethyl ester in non‐polar solvents by strong neutral bases: implication for ion‐pair kinetic basicity and hydrolysis
Authors: Lin Han‐Yuan , Lay Eddy , Wen Wen‐Yen , Dewi Hamza , Cheng Yu‐Chi , Tsai Shau‐Wei
Published: April 2004

By using strong neutral bases as catalyst, a detailed investigation of the racemization of (S)‐naproxen 2,2,2‐trifluoroethyl ester was conducted in the non‐polar solvents isooctane, cyclohexane and n‐hexane. The second‐order interconversion constant $k^*_{\rm int}$ as representing the ion‐pair kinetic basicity in isooctane was first estimated and correlated with the equilibrium ion‐pair basicity pKip in tetrahydrofuran, giving slopes of 0.768 and 0.689 for non‐phosphazene and phosphazene bases, respectively, in the Brønsted correlations. The result was further compared with that for (S)‐naproxen 2,2,2‐trifluoroethyl thioester, showing about a 1–2 orders of magnitude enhancement of $k^*_{\rm int}$ for the corresponding thio‐containing analogue. A smaller influence of non‐polar solvents (i.e. isooctane, n‐hexane and cyclohexane) on $k^*_{\rm int}$ was found. Kinetic analysis of the racemization and hydrolysis of (S)‐naproxen 2,2,2‐trifluoroethyl ester in isooctane and n‐hexane containing 7‐methyl‐1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene and water suggests nucleophilic hydrolysis by the base, where the breakdown of tetrahedral intermediates IR1 and IS1 is the rate‐limiting step and the hydrolysis constant khy is in proportion to the product of base and ion‐pair concentrations. Copyright © 2004 John Wiley & Sons, Ltd.
Conformations of N,N‐diethyl‐β‐alanine and β‐alanine as a function of solvent
Authors: Piro Nicholas A. , Stein Robin S. , Roberts John D.
Published: April 2004

Conformational equilibria of N,N‐diethyl‐β‐alanine were estimated from vicinal proton–proton coupling constants between the CH2CH2 group in protic and aprotic solvents of different polarities. β‐Alanine was similarly studied in dimethyl sulfoxide (DMSO). In general, the results for both substances correspond fairly well with those reported earlier for β‐alanine in neutral and acidic aqueous solutions. There appeared to be little conformational preference for N,N‐diethyl‐β‐alanine in any of the solvents used, ranging from water to dichloromethane. The exception was a moderate preference (66–73%) for the trans conformer displayed by the conjugate base of N,N‐diethyl‐β‐alanine in all of the solvents studied. Copyright © 2004 John Wiley & Sons, Ltd.
Influence of solvent viscosity on the rate of hydrolysis of dipeptides by carboxypeptidase Y
Authors: Kanosue Yoshifumi , Kojima Satoshi , Ohkata Katsuo
Published: April 2004

The influence of solvent viscosity on the rate of enzymatic hydrolysis of a series of dipeptides (Z‐Phe‐Gly, Z‐Phe‐Sar, Z‐Phe‐Ala, Z‐Phe‐NMeAla, Z‐Phe‐Aib and Z‐Phe‐Pro) by carboxypeptidase Y was investigated. The effect of solvent viscosity on the enzymatic hydrolysis revealed that whereas all kcat values decreased with viscosity, those of the N‐alkyl peptides decreased more than those of the N‐H peptides. The kinetic behaviour implies the involvement of conformational changes of the enzyme in terms of the ‘induced‐fit’ process. Copyright © 2004 John Wiley & Sons, Ltd.