bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface‐enhanced Raman scattering of 4,4′‐dicyanobiphenyl on gold and silver nanoparticle surfaces
Authors: Lee Chung‐ro , Bae Sung Jin , Gong Myoung‐seon , Kim Kwan , Joo Sang‐Woo
Published: October 2002

The adsorption behavior of 4,4′‐dicyanobiphenyl (DCBP) on Ag and Au nanoparticle surfaces was studied by surface‐enhanced Raman scattering (SERS). The absence of the ring CH band denoted a flat orientation of the biphenyl ring on Ag and Au. The red shift of the ν8a band indicated a direct ring π‐orbital interaction with the surfaces. The two benzene rings of DCBP appeared to lie on the same plane with a π‐type interaction upon adsorption on the surfaces. The ν(CN) bands were blue shifted in the Ag and Au SERS spectra by 2 and 22 cm−1, respectively from the ordinary Raman spectrum. The orientation of DCBP on the Ag and Au surfaces was analyzed by the relative enhancement factors of the vibrational bands based on the electromagnetic SERS selection rule. Copyright © 2002 John Wiley & Sons, Ltd.
H2O2‐mediated oxidation of tetrahydrobiopterin: Fourier transform Raman investigations provide mechanistic implications for the enzymatic utilization and recycling of this essential cofactor
Authors: Moore Jeremy , Wood John M. , Schallreuter Karin U.
Published: October 2002

The oxidation of (6R)‐L‐erythro‐5,6,7,8‐tetrahydrobiopterin (6BH4) by H2O2 was examined by Fourier transform Raman spectroscopy. Initial investigations indicated that oxidation proceeds by incorporation of the H2O2 into the 6BH4 molecule without the formation of any additional water. In addition, the pyrimidine ring is affected with the shift of the double bond from the N1—C2 to the C2—N3 position. Such rearrangements of this double bond are observed after the production of either a carbinolamine or quinonoid species. Using deuterium exchange experiments, it was possible to substantiate that the oxidation of 6BH4 initially proceeds by the formation of a 4a‐OH‐carbinolamine intermediate prior to its spontaneous dehydration yielding the quinonoid dihydro species (qBH2). Furthermore, the hydrogen on the hydroxyl group of the carbinolamine interacts with the oxygen of the carbonyl group at the C4 position of the pyrimidine ring. It is proposed that this interaction facilitates the dehydration of the carbinolamine, thus explaining its instability. Furthermore, a mechanism for the dehydration reaction is suggested, wherein the 4a‐hydroxyl group forms an H‐bond to the carbonyl group, thus making the oxygen of the hydroxyl group more susceptible to attack by the proton at position N5 of the pyrazine ring, resulting in qBH2 production concomitant with the loss of a water molecule. Upon increasing the concentration of H2O2 the qBH2 converts to 7,8‐BH2, which is further oxidized to L‐biopterin. Taken together, our results do not support an earlier proposed mechanism implicating a hydroperoxide intermediate in this oxidation reaction. Copyright © 2002 John Wiley & Sons, Ltd.
Effects of processing and cooking on ascorbic acid content of chickpea (Cicer arietinum L) varieties
Authors: Sood Monika , Malhotra S R
Published: October 2002

Chickpea (Cicer arietinum L) is an important source of protein in several developing countries. Two commonly grown chickpea cultivars, HPG‐17 and C‐235, were evaluated for their physicochemical characteristics such as 100‐seed weight and density. Both chickpea varieties were subjected to various processing treatments and then analysed for their ascorbic acid content. The ascorbic acid content was generally found to be higher in the C‐235 variety, but it was higher in the HPG‐17 variety after germination. Significant results were obtained for both varieties after various treatments such as pressure cooking, germination, parching and solar cooking. It was found that the ascorbic acid content in both varieties decreased after all treatments except germination.

© 2001 Society of Chemical Industry
Effects of rice properties and emulsifiers on the quality of rice pasta
Authors: Lai Hsi‐Mei
Published: October 2002

Two commercial rice flours (GTIndica and GTJaponica, with amylose contents of 306.8 and 185.2 g kg−1 respectively) and their blended flours were used to make rice pasta. The effects of two emulsifiers (distilled glyceryl monostearate (GMS) and a commercial emulsifier (KM3000)) on the pasting and thermal properties of dried rice pasta were investigated using a Rapid Visco Analyser (RVA) and a differential scanning calorimeter (DSC). The rice pasta made from high‐amylose rice flour had better extrusion properties, better texture, whiter colour, less cooking loss and better eating quality than that made from low‐amylose rice flour. The maximum amount of low‐amylose rice flour that could be blended in for making an acceptable quality of rice pasta was 500 g kg−1. A soft texture, low adhesiveness and low gumminess of cooked rice pasta were obtained by adding 10 g kg−1 GMS. SEM investigations showed that use of an emulsifier restricted the swelling of starch granules, especially for the pasta made from high‐amylose rice flour.

© 2001 Society of Chemical Industry
Antioxidant activity of natural vitamin E extracted from soybean sludge as assessed by chemiluminescence
Authors: Yu Wenli , Zhao Yaping , Xue Zheng , Jin Hui , Wang Dapu , Liang Xiaofeng , Hu Tianxi
Published: October 2002

The antioxidant activity of natural vitamin E (VE) towards superoxide anion, hydroxyl radical and lipid free radicals was investigated using a chemiluminescence technique. VE was extracted from soybean sludge, where it was present at a concentration of 600 g kg−1 as determined by HPLC. Superoxide anions, hydroxyl radicals and lipid free radicals were generated by the pyrogallol autoxidation system, the Fenton reaction system and the AAPH‐induced γ‐linolenic acid peroxidation system respectively. VE rapidly scavenged hydroxyl radicals and lipid free radicals. The efficient concentration (EC50) of VE against both was 0.1 mg ml−1. A reaction time of 6 s was adequate to scavenge hydroxyl radicals and a reaction time of 24 s was enough to scavenge lipid free radicals. However, VE scavenged superoxide anions at a relatively low rate, and the extent of scavenging was less than 20% even after 3 min at a VE concentration of 4.3 mg ml−1.

© 2001 Society of Chemical Industry
Flavour evaluation of three black mulberry (Morus nigra) cultivars using GC/MS, chemical and sensory data
Authors: Elmacı Yeşim , Altuğ Tomris
Published: October 2002

The flavour characteristics of three black mulberry (Morus nigra) cultivars from the Aegean region of Turkey were investigated using GC/MS and sensory analysis techniques. A total of 18 flavour compounds were identified by GC/MS in the three cultivars. Total sugar content varied between 11.3 and 16.2%, pH between 3.60 and 3.80 and total acidity between 1.51 and 1.79%. The sensory assessment indicated that black mulberry has fruity, sweet, sour, musky and woody flavour notes and fruity, acid, musky, leafy and woody‐fresh aroma characteristics. The evaluation of GC/MS and sensory data revealed that ethyl linolenate was the most effective compound contributing to the unique flavour of black mulberry.

© 2002 Society of Chemical Industry
Insecticidal compounds from Phellodendron amurense active against Drosophila melanogaster
Authors: Miyazawa Mitsuo , Fujioka Jun , Ishikawa Yukio
Published: October 2002

In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, the methanolic extract of the bark of Phellodendron amurense Rupr was found to show insecticidal activity against larvae of Drosophila melanogaster Meigen. Two alkaloids, berberine (1) and palmatine (2), were isolated by bioassay‐guided fractionation of the extract. Insecticidal activity against larvae of D melanogaster was demonstrated; 1 and 2 gave LC50 values of 2.44 and 8.45 µmol ml−1 diet respectively. Acute toxicity against adult D melanogaster was also found; 1 had the more potent activity, with an LD50 value of 19.0 µg per adult. However, 2 had weak activity in this study. Therefore 1 was identified as an insecticidal compound from the bark of P amurense Rupr.

© 2002 Society of Chemical Industry
The production of aflatoxins in fresh date fruits and under simulated storage conditions
Authors: Shenasi Mariam , Candlish Alan A G , Aidoo Kofi E
Published: October 2002

Sixteen varieties of date fruit (Phoenix dactylifera) at three stages of maturation (Kimri, Rutab and Tamr) were examined for the presence of fungi and analysed for aflatoxins B1, B2, G1 and G2 and sterigmatocystin. Single samples of each variety were used in the study. Samples as received were initially examined for mycoflora and toxin levels and then stored at 98% relative humidity and 30 °C for 14 days to investigate the effects of possible adverse storage conditions on mycoflora and, in particular, aflatoxin formation. All samples showed an absence of aflatoxins and their precusor, sterigmatocystin, after adverse storage for 14 days, although aflatoxin‐producing Aspergillus flavus isolates were identified in 10 varieties at the first stage of maturation (Kimri). High fungal counts were associated with the Rutab stage and low counts with the Tamr stage. The counts of A flavus ranged from 5.00 to 8.16 log10(cfu g−1) under simulated storage conditions, and three varieties contained significant levels of aflatoxin B1 or B2 ranging from 35 to 11 610 µg kg−1. Sterigmatocystin was not detected in any of the samples as received or under simulated storage conditions.

© 2002 Society of Chemical Industry
Low‐salt restructured fish products using microbial transglutaminase as binding agent
Authors: Téllez‐Luis Simón J , Uresti Rocío M , Ramírez José A , Vázquez Manuel
Published: October 2002

Low‐salt restructured silver carp products were obtained using mechanically deboned fish meat from filleting wastes of silver carp (Hypophthalmichthys molitrix). The additives used were NaCl at three levels (0 (control), 10 and 20 g kg−1) and microbial transglutaminase (MTGase) also at three levels (0 (control), 3 and 6 g kg−1). The fish meat was massaged with the additives at <15 °C for 1 h. The massaged fish paste was then packed into steel stainless tubes and cooked at 40 °C for 30 min followed by 90 °C for 15 min. Changes in mechanical properties (texture profile analysis and punch test), solubility, electrophoretic profile and expressible water were evaluated. Hardness was in the range from 26.3 to 52.4 N, cohesiveness varied from 0.185 to 0.318 and springiness varied from 0.418 to 0.768. Increasing the amount of both additives improved the mechanical and functional properties of the restructured silver carp products. MTGase activity was associated with a decrease in protein solubility and a decrease in the myosin band (SDS‐PAGE). Increasing NaCl decreased the amount of expressible water. The results indicated that it is feasible to obtain low‐salt restructured silver carp products with improved mechanical and good functional properties using 3 g kg−1 MTGase and 10 g kg−1 NaCl.

© 2002 Society of Chemical Industry
Chemical basis for the low sensory perception of the Ganxet bean (Phaseolus vulgaris) seed coat
Authors: Casañas Francesc , Pujolà Montserrat , Bosch Lluís , Sánchez Esther , Nuez Fernando
Published: October 2002

The Ganxet bean (Phaseolus vulgaris L), highly appreciated in Catalan gastronomy, has a higher proportion of seed coat than other beans (eg White Kidney or Faba Asturiana); however, general diners and sensory tests point out a lower perception of this seed coat. The differences in chemical composition between Ganxet, White Kidney and Faba Asturiana beans, before and after cooking, were established and related to perceived sensory differences in seed coat content. Ganxet's higher absolute and percentage losses of total dietary fibre (19.5%), soluble dietary fibre (32.5%), cellulose (25.6%) and pectins (38.1%) break down the consistency of the seed coat during cooking, which would explain its low sensory perception. The high loss of cellulose during cooking could be due to its partial combination with proteins, which would aid its breakdown.

© 2002 Society of Chemical Industry
A case study on the implementation of a knowledge management strategy oriented to innovation
Authors: Forcadell Francisco J. , Guadamillas Fátima
Published: October 2002

A critical aspect of business management is the successful creation of processes which drive the development of a continuous flow of innovation, to give a basis for competitive advantage. To reach this goal, the establishing of a knowledge management (KM) strategy may be considered the best way to channel the organization's efforts to this end. Knowledge management is understood in a wide sense as a process of overall change in the organization, focused on innovation, and especially related to the participation of every employee in the processes of creation and transmission of knowledge. This study analyzes the implementation of an innovation and KM strategy in the Irizar company, a maker of luxury coach bodywork. According to The Economist Intelligence Unit, Irizar is the most efficient company in the world in its sector. Irizar's success has been built on a system of self‐management and participation, organizing its activity into processes and using multidisciplinary work teams. This type of organization has outstripped the traditional model, based on functions and the division of labour, and has permitted a centering of effort on those activities which add value. Another defining characteristic of Irizar is its combination of continuous improvement with radical changes and process re‐engineering. A series of organizational factors are extracted from the case study which were successful in implementing the strategy. The study shows how the organization achieved the promotion of experience transmission and the generation of continuous innovation. It also makes clear that the firm's values and corporate culture are essential for success in this process. Copyright © 2002 John Wiley & Sons, Ltd.
Degradation processes and nutrient constraints in sodic soils
Authors: Qadir M. , Schubert S.
Published: October 2002

Accumulation of excess sodium (Na+) in a soil causes numerous adverse phenomena, such as changes in exchangeable and soil solution ions and soil pH, destabilization of soil structure, deterioration of soil hydraulic properties, and increased susceptibility to crusting, runoff, erosion and aeration, and osmotic and specific ion effects on plants. In addition, serious imbalances in plant nutrition usually occur in sodic soils, which may range from deficiencies of several nutrients to high levels of Na+. The structural changes and nutrient constraints in such soils ultimately affect crop growth and yield. The principal factor that determines the extent of adverse effects of Na+on soil properties is the accompanying electrolyte concentration in the soil solution, with low concentration promoting the deleterious effects of exchangeable Na+even at exchangeable sodium percentage (ESP) levels less than 5. Consequent to an increase in the use of poor quality waters and soils for crop production, the problems of sodic soils can be expected to increase in future. The mechanisms that explain sodic behaviour can provide a framework in which slaking, swelling and dispersion of clay together with nutrient constraints in sodic soils may be assessed so that the practices to manage such soils can be refined for long‐term sustainable agriculture. Copyright © 2002 John Wiley & Sons, Ltd.
Scatter‐limited phototherapy: A model for laser treatment of skin
Authors: Reinisch Lou
Published: October 2002

Background and Objectives

To effectively deliver laser light into the skin for non‐ablative resurfacing, hair removal, and other applications, one must account for scatter, absorption, and thermal diffusion. A novel method to control the penetration of laser light into tissue is proposed. This method uses the incident beam diameter, the pulse duration, and the intrinsic light scattering of tissues such as skin to limit the laser light penetration and thermal damage. We term this innovative laser delivery concept ‘scatter‐limited phototherapy’.

Study Design/Materials and Methods

This study demonstrates how the delivery mechanism simplifies the non‐ablative treatment of sun‐damaged skin. Calculations are based upon Gaussian scatter of light and isotropic thermal diffusion. Calculations of light distribution and profiles of temperature increase are created.

Results

Using an optical fiber delivery system with the appropriate diameter, coupled with skin surface protection, one can create thermal damage at a given depth with preservation of the epidermis.

Conclusions

Scatter‐limited phototherapy is a predictive model, allowing one to design better laser delivery systems. Scatter‐limited phototherapy should also be applicable to other fields of dermatologic surgery, such as hair removal and the treatment of vascular lesions. Additionally, other medical specialties will be able to use the concept of scatter‐limited phototherapy to predict and better understand laser–tissue interactions. Lasers Surg. Med. 30:381–388, 2002. © 2002 Wiley‐Liss, Inc.
Cavity preparation using a superpulsed 9.6‐μm CO2 laser—a histological investigation
Authors: Müllejans R. , Eyrich G. , Raab W.H.‐M. , Frentzen M.
Published: October 2002

Background and Objectives

The superpulsed 9.6‐μm CO2 laser is an effective laser for ablating dental tissues and decay. This histological study compares laser class V preparations with conventional treatment to evaluate the resulting formation at the cavity walls.

Study Design/Materials and Methods

Four class V preparations (one made with a diamond drill and three with the CO2 laser (9.6 μm, 60 microseconds pulse width, 40 mJ pulse energy, 100 Hz, integrated scanner system, water cooling) were performed on ten extracted teeth. The cavities were filled with a composite resin partly including enamel and dentine conditioning.

Results

After laser preparation, no cracks or signs of carbonisation were detected. The results were comparable to those attained with conventional treatment. Following cavity filling without prior conditioning, gaps were noted at the cavosurface indicating a lack of adhesion. Dentinal bonding decreased gap formation significantly.

Conclusion

The 9.6‐μm CO2 laser is an effective tool for cavity preparation. Lasers Surg. Med. 30:331–336, 2002. © 2002 Wiley‐Liss, Inc.
Induction of caspase‐mediated apoptosis and cell‐cycle G1 arrest by selenium metabolite methylselenol
Authors: Wang Zaisen , Jiang Cheng , Lü Junxuan
Published: October 2002

Previous work based on mono‐methyl selenium compounds that are putative precursors of methylselenol has strongly implicated this metabolite in the induction of caspase‐mediated apoptosis of human prostate carcinoma and leukemia cells and G1 arrest in human vascular endothelial and cancer epithelial cells. To test the hypothesis that methylselenol itself is responsible for exerting these cellular effects, we examined the apoptotic action on DU145 human prostate cancer cells and the G1 arrest effect on the human umbilical vein endothelial cells (HUVECs) of methylselenol generated with seleno‐L‐methionine as a substrate for L‐methionine‐α‐deamino‐γ‐mercaptomethane lyase (EC4.4.1.11, also known as methioninase). Exposure of DU145 cells to methylselenol so generated in the sub‐micromolar range led to caspase‐mediated cleavage of poly(ADP‐ribose) polymerase, nucleosomal DNA fragmentation, and morphologic apoptosis and resulted in a profile of biochemical effects similar to that of methylseleninic acid (MSeA) exposure as exemplified by the inhibition of phosphorylation of protein kinase AKT and extracellularly regulated kinases 1/2. In HUVEC, methylselenol exposure recapitulated the G1 arrest action of MSeA in mitogen‐stimulated G1progression during mid‐G1 to late G1. This stage specificity was mimicked by inhibitors of phosphatidylinositol 3‐kinase. The results support methylselenol as an active selenium metabolite for inducing caspase‐mediated apoptosis and cell‐cycle G1 arrest. This cell‐free methylselenol‐generation system is expected to have significant usefulness for studying the biochemical and molecular targeting mechanisms of this critical metabolite and may constitute the basis of a novel therapeutic approach for cancer, using seleno‐L‐methionine as a prodrug. © 2002 Wiley‐Liss, Inc.
Severe generalized dystonia due to primary putaminal degeneration: Case report and review of the literature
Authors: Walker Ruth H. , Purohit Dushyant P. , Good Paul F. , Perl Daniel P. , Brin Mitchell F.
Published: October 2002

Putaminal lesions of a variety of etiologies may cause secondary dystonia. We report on a case of primary putaminal degeneration as a cause of severe childhood‐onset generalized dystonia and review the literature of the pathology of dystonia. A 44‐year‐old patient with severe generalized childhood‐onset dystonia and macrocephaly underwent neurological evaluation and neuropathological examination. Neurological examination was normal apart from dystonia and signs referable to prior cryothalamotomy. Workup for metabolic and genetic causes of dystonia was negative. Neuroimaging showed severe bilateral putaminal degeneration, which subsequently correlated with the neuropathological findings of gliosis, spongiform degeneration, and cavitation. The substantia nigra pars compacta contained a normal number of neurons but decreased tyrosine hydroxylase immunoreactivity. There were no histopathological markers of other metabolic or degenerative diseases. © 2002 Movement Disorder Society.
Autosomal dominant adult neuronal ceroid lipofuscinosis: Parkinsonism due to both striatal and nigral dysfunction
Authors: Nijssen Peter C.G. , Brusse Esther , Leyten Antonius C.M. , Martin J.J. , Teepen Johannes L.J.M. , Roos Raymund A.C.
Published: October 2002

We describe a family with adult neuronal ceroid lipofuscinosis, with apparent autosomal dominant inheritance, observed in six affected individuals in three generations. Disease onset was usually in the fifth decade, but was earlier in the youngest generation. Early symptoms consisted of myoclonus in face and arms, epilepsy, auditory symptoms, cognitive decline, or depression. Parkinsonism occurred a few years after disease onset, with stooped posture, shuffling gait, bradykinesia, and mask face. Four subjects deteriorated to a state of severe handicap, with severe dementia, contractures, dysphagia, and dysarthria. Leg weakness evolved to flaccid paraparesis in two patients. Diagnosis was confirmed by brain biopsy in one patient and full autopsy in two patients. Abundant intraneuronal storage of autofluorescent material was found throughout the brain. Electron microscopy showed granular osmiophilic deposits and scarce fingerprint profiles. Striking loss of neurons in the substantia nigra pars compacta and reticulata was found. 123I‐IBZM Single photon emission computed tomography in two patients showed loss of postsynaptic D2 receptor binding in the striatum. We conclude that parkinsonism in ANCL is likely to be caused by both presynaptic nigral cell loss and postsynaptic striatal degeneration. © 2002 Movement Disorder Society.
Parkinsonism in multiple system atrophy: Natural history, severity (UPDRS‐III), and disability assessment compared with Parkinson's disease
Authors: Tison François , Yekhlef Farid , Chrysostome Virginie , Balestre Eric , Quinn Niall P. , Poewe Werner , Wenning Gregor K.
Published: October 2002

We analyzed parkinsonian features in multiple system atrophy (MSA) compared with age‐ and disease duration‐matched Parkinson's disease (PD) patients, and assessed the applicability of the Unified Parkinson's Disease Rating Scale (UPDRS) ‐III motor scale as a means of rating their severity. Cross‐sectional analysis of parkinsonism was done using UPDRS‐III, International Cerebellar Atatia Rating Scale, and disability scales (Hoehn and Yahr [H&A], Schwab and England, Katz and Lawton) in 50 unselected MSA patients and in 50 matched PD patients. At symptom onset, falls occurred 10 times more frequently in MSA, whereas limb tremor was 10 times more common in PD. At first visit (10.2 months), hemiparkinsonism and pill‐rolling rest tremor were less common in MSA. Hypomimia, atypical rest, postural or action tremor, as well as postural instability were more frequent in MSA. At study examination (62.4 months), parkinsonian signs in MSA patients were more frequently symmetrical and associated with axial rigidity, antecollis and postural instability. A levodopa response of >50% was seen in <10% of MSA patients. Modified H&Y stages (3.2 ± 1.3 vs. 2.2 ± 0.78) and UPDRS‐III scores (48.14 ± 19.5 vs. 31.74 ± 12.9) were significantly (P = 0.0001) higher in MSA. The internal consistency of the UPDRS‐III was fair in MSA patients (Cronbach's α >0.90), and correlated well with marked dependency on the Schwab and England and Katz and Lawton scales. Factor structure analysis of UPDRS‐III in MSA showed five clinically distinct subscores accounting for 74% of the variance, differing from PD by the dependency of the face–speech and limb bradykinesia items and independence of the postural–action tremor from the rest tremor items. There was a significant correlation (R2 = 0.70, P = 0.001) between ICARS ataxia and UPDRS‐III scores in MSA patients. Results confirm a distinct profile of parkinsonism in MSA and greater severity and disability compared with PD. It also indicates that the UPDRS‐III provides a useful severity measure of parkinsonism in MSA, albeit contaminated by additional cerebellar dysfunction. © 2002 Movement Disorder Society
Clinical, 18F‐dopa PET, and genetic analysis of an ethnic Chinese kindred with early‐onset parkinsonism and parkin gene mutations
Authors: Wu Ruey‐Meei , Shan Din‐E , Sun Chen‐Ming , Liu Ren‐Shyan , Hwu Wuh‐Liang , Tai Chun‐Hwei , Hussey Jennifer , West Andrew , Gwinn‐Hardy Katrina , Hardy John , Chen Judy , Farrer Matt , Lincoln Sarah
Published: October 2002

We report on clinical 18F‐labeled 6‐fluorodopa (18F‐dopa) positron emission tomography (PET) and molecular genetic analyses of an ethnic Chinese family in which three siblings presented with early‐onset Parkinson's disease. As described in some parkin patients, neither sleep benefit nor diurnal fluctuation was noted. Interestingly, depression, anxiety, and obsessive–compulsive disorders were manifest. The 18F‐dopa PET scans showed bilateral presynaptic dopaminergic dysfunction without marked lateralization. Molecular genetic analysis showed identical chromosome 6 haplotypes inherited by affected subjects, with alternate allelic deletions of parkin exons 3 and 4. Furthermore, mRNA analyses identified aberrantly spliced parkin transcripts, suggesting that unusual parkin protein isoforms may be expressed in the brain and retain some function. © 2002 Movement Disorder Society
A compact microstrip interdigital stepped‐impedance band‐pass filter with enhanced stop band
Authors: Crute John R. , Davis Lionel E.
Published: October 2002

Microstrip bandpass filters are widely used in a variety of microwave subsystems to select a desired band of frequencies. However, common filter topologies with uniform impedance resonators exhibit poor stop‐band performance. This is due to the occurrence of harmonic passbands at multiples of the fundamental passband frequency. This study describes the design of a compact interdigital microstrip filter, using short‐circuit stepped‐impedance resonators (SCSIRs) to enhance the harmonic stop‐band response. Measurements on an experimental filter, with a design center frequency of 2442 MHz and 3‐dB bandwidth of 611 MHz (25%), show an increase in the first harmonic passband frequency to 8809 MHz. At three times the fundamental passband center frequency (7326 MHz), stop‐band attenuation is better than −35 dB. The results demonstrate the usefulness of SCSIRs for improving the stop‐band performance of interdigital bandpass filters, with only a small increase in overall size. © 2002 Wiley Periodicals, Inc. Microwave Opt Technol Lett 34: 336–340, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10455
Activity of postoperative carboplatin, etoposide, and high‐dose methotrexate in pediatric CNS embryonal tumors: Results of a phase II study in newly diagnosed children
Authors: Kellie Stewart J. , Wong Christopher K.F. , Pozza Luciano Dalla , Waters Keith D. , Lockwood Liane , Mauger David C. , White Les
Published: October 2002

Background

Chemotherapy is used as an alternative to irradiation or to minimize the irradiation exposure among infants with medulloblastoma or other CNS embryonal tumors. Adjuvant chemotherapy is commonly used in older children with high‐risk medulloblastoma to improve survival or to allow a reduction in the craniospinal irradiation dose in standard‐risk patients. However, optimal multimodality therapy, including the precise role of chemotherapy, has not been defined for these groups of patients. The objective of the present study is to assess the efficacy and toxicity of four postoperative courses of carboplatin, etoposide, and high‐dose methotrexate in newly diagnosed children with medulloblastoma or other CNS embryonal tumors.

Procedure

Twenty‐eight children, aged from 0.3 to 15.9 years (median, 6.2 years) with post‐operative measurable residual CNS embryonal tumors were enrolled, comprising medulloblastoma (n = 19), supratentorial PNET (n = 7), and pineoblastoma (n = 2). Post‐operative chemotherapy comprised carboplatin 350 mg/m2 and etoposide 100 mg/m2 on Days 1 & 2, and methotrexate 8 g/m2 on Day 3, repeated at 21–28‐day intervals for a total of four courses. Therapy following completion of the initial Phase II study was influenced by patient age and investigator preference.

Results

The combined complete response rate (CR, 7/19) and partial response rate (PR, 7/19) was 74% in patients with medulloblastoma, 89% for patients with PNET/pineoblastoma (CR, 2/9 and PR, 6/9), and for all patients it was 79%. Patients aged < 3 years at diagnosis had a combined PR and CR rate of 71% compared to 81% in patients aged > 3 years. Treatment was well tolerated although myelosuppression and thrombocytopenia were common.

Conclusions

The combination of carboplatin, etoposide, and high‐dose methotrexate is highly active in pediatric patients with CNS embryonal tumors. Med Pediatr Oncol 2002;39:168–174. © 2002 Wiley‐Liss, Inc.
Theory of nonexponential NMR signal decay in liver with iron overload or superparamagnetic iron oxide particles
Authors: Jensen J.H. , Chandra R.
Published: October 2002

A quantitative theory is proposed for the nonexponential NMR proton signal decay observed in liver with iron overload or superparamagnetic iron oxide particles. This effect occurs for Carr‐Purcell‐Meiboom‐Gill (CPMG) sequences and is argued to be a direct consequence of the strong magnetic field inhomogeneities generated by the iron, rather than being due to tissue compartments. An approximate mathematical form is given for the signal decay, which is fit to experimental data for samples of rat liver with iron oxide particles, for samples of marmoset liver with hemosiderosis, and for in vivo human liver with hereditary hemochromatosis. The fitting parameters obtained are consistent with the pattern of iron deposition determined from histology. For the case of hereditary hemochromatosis, a good correlation is found between a parameter characterizing the nonexponential decay and the iron concentration. Implications for practical MR quantification of hepatic iron are discussed. Magn Reson Med 47:1131–1138, 2002. © 2002 Wiley‐Liss, Inc.
Generalized autocalibrating partially parallel acquisitions (GRAPPA)
Authors: Griswold Mark A. , Jakob Peter M. , Heidemann Robin M. , Nittka Mathias , Jellus Vladimir , Wang Jianmin , Kiefer Berthold , Haase Axel
Published: October 2002

In this study, a novel partially parallel acquisition (PPA) method is presented which can be used to accelerate image acquisition using an RF coil array for spatial encoding. This technique, GeneRalized Autocalibrating Partially Parallel Acquisitions (GRAPPA) is an extension of both the PILS and VD‐AUTO‐SMASH reconstruction techniques. As in those previous methods, a detailed, highly accurate RF field map is not needed prior to reconstruction in GRAPPA. This information is obtained from several k‐space lines which are acquired in addition to the normal image acquisition. As in PILS, the GRAPPA reconstruction algorithm provides unaliased images from each component coil prior to image combination. This results in even higher SNR and better image quality since the steps of image reconstruction and image combination are performed in separate steps. After introducing the GRAPPA technique, primary focus is given to issues related to the practical implementation of GRAPPA, including the reconstruction algorithm as well as analysis of SNR in the resulting images. Finally, in vivo GRAPPA images are shown which demonstrate the utility of the technique. Magn Reson Med 47:1202–1210, 2002. © 2002 Wiley‐Liss, Inc.
MRI cardiac tagging using a sinc‐modulated RF pulse train
Authors: Wu Ed X. , Towe Christopher W. , Tang Haiying
Published: October 2002

A method of spatial modulation of magnetization using the RF pulse train is described for improved cardiac tagging. The method is based on a sinc‐modulated RF pulse train in the presence of constant gradient. Such an RF pulse train yields a rectangular profile of saturated magnetization, and the bandwidth of the sinc envelope controls the width of the saturation tag. Compared to DANTE and SPAMM tagging techniques, this method offers sharper‐edged tags and the ability to change the ratio of tag width to tag separation. The approach was implemented on a 9.4 T vertical bore NMR system and demonstrated with both phantom and in vivo mouse heart studies. Magn Reson Med 48:389–393, 2002. © 2002 Wiley‐Liss, Inc.
CD11b+ neutrophils predominate over RAM11+ macrophages in stretch‐injured muscle
Authors: St. Pierre Schneider Barbara , Brickson Stacey , Corr David T. , Best Thomas
Published: October 2002

The purpose of this study was to determine whether both neutrophils and macrophages infiltrate the hematoma site of stretch‐injured rabbit tibialis anterior muscle. The Mab.198 antibody was used to detect CD11b+ neutrophils or macrophages. Neutrophils were identified specifically by using the RPN3/57 antibody. The RAM11 antibody was used to detect macrophages. The histological characteristics of the hematoma site, torn fibers or inflammatory cells, were present primarily at 4 and 24 h, but not at 48 and 72 h after injury. A difference in the Mab.198+ cellular concentration was detected over time between uninjured and injured muscles (P = 0.03). The injured‐uninjured difference in the RPN3/57+ or RAM11+ cellular concentrations approached significance (P = 0.07) or else was deemed insignificant (P = 0.13), respectively. Therefore, neutrophils may predominate over RAM11+ macrophages in stretch‐injured muscle. These findings may influence the antiinflammatory strategies used to treat stretch injuries. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 837–844, 2002
Effect of triggering potential on calculations of jitter in single‐fiber EMG
Authors: Baslo M. Bariş , Yildiz Nebil , Yalinay Pinar , Ertaş Mustafa
Published: October 2002

Jitter values are calculated in reference to a triggering potential during single‐fiber electromyography (SFEMG) performed during voluntary contraction. When there are more than two single‐fiber action potentials (SFAP) and the selected triggering potential is from an abnormal end‐plate, all the jitters calculated from the same trace will be affected. In this study, the effect of triggering potential on calculated jitter was investigated in myasthenic and healthy volunteers by switching the triggering potential and recalculating the jitter off‐line. Selecting a triggering potential from an abnormal end‐plate increased the number of abnormal individual jitters as well as the mean jitter. Therefore, if the equipment software has the capacity to change the trigger potential, the triggering potential should not be from an abnormal end‐plate if all possible jitter values are to be calculated for traces having three or more single‐fiber potentials. Otherwise, only one jitter value should be included from any one trace to prevent false‐positive results. © 2002 Wiley Periodicals, Inc. Muscle Nerve 25: 000–000, 2002
Modelling of anisotropic damage in brittle rocks under compression dominated stresses
Authors: Lu Y.F. , Shao J.F.
Published: October 2002

A new model for describing induced anisotropic damage in brittle rocks is proposed. Although phenomenological, the model is based on physical grounds of micromechanical analysis. Induced damage is represented by a second rank tensor, which is related to the density and orientation of microcracks. Damage evolution is related to the propagation condition of microcracks. The onset of microcrack coalescence leading to softening behaviour is also considered. The effective elastic compliance of the damaged material is obtained from a specific form of Gibbs potential. Irreversible damage‐related strains due to residual opening of microcracks after unloading are also captured. All the model's parameters could be determined from conventional triaxial compression tests. The proposed model is applied to a typical brittle rock. Comparison between test data and numerical simulations shows an overall good agreement. The proposed model is able to describe the main features related to induced microcracks in brittle geomaterials. Copyright © 2002 John Wiley & Sons, Ltd.
Length‐constrained path‐matchings in graphs
Authors: Ghodsi M. , Hajiaghayi M. T. , Mahdian M. , Mirrokni V. S.
Published: October 2002

The path‐matching problem is to find a set of vertex‐ or edge‐disjoint paths with length constraints in a given graph with a given set of endpoints. This problem has several applications in broadcasting and multicasting in computer networks. In this paper, we study the algorithmic complexity of different cases of this problem. In each case, we either provide a polynomial‐time algorithm or prove that the problem is NP‐complete. © 2002 Wiley Periodicals, Inc.
Initial stages of radial glia astrocytic transformation in the early postnatal anterior subventricular zone
Authors: Alves José A. J. , Barone Patrick , Engelender Simone , Fróes Maira M. , Menezes João R. L.
Published: October 2002

In the early postnatal subventricular zone (SVZ), two seemingly unrelated events occur simultaneously: a massive tangential migration of neuroblasts towards the olfactory bulb, known as the rostral migratory stream (RMS), and the outward movement of radial glia (RG) undergoing astrocytic transformation. Because of the orthogonal arrangement between these two sets of cells, little, if any, relevance has been ascribed for their possible interactions. By depositing DiI at the pial surface we have studied RG transformation within the SVZ/RMS, from birth up to the end of the first postnatal week. While still within the SVZ/RMS, RG morphology changed from simple bipolar to highly complex branched profiles, attaining their highest degree of complexity at the interface of the SVZ with the overlying white matter. At this interface cell bodies of radial glia accumulate and their processes run tangentially, surrounding the SVZ/RMS. Processes of RG surrounding the SVZ/RMS could also be observed by immunostaining for vimentin, GFAP, and nestin. In contrast, in the white matter all DiI‐labeled RG presented a simple bipolar profile. These results indicate that the outward radial migration of the transforming RG does not occur uniformly. Instead, the different morphologies and cell densities that RG assume when they cross the SVZ/RMS and overlying white matter imply different migratory behaviors. Finally, our data suggest that RG provide a cellular scaffold to the early postnatal SVZ/RMS, much in the same way as astrocytes in the adult RMS. © 2002 Wiley Periodicals, Inc. J Neurobiol 52: 251–265, 2002
Solving 2D transient rolling contact problems using the BEM and mathematical programming techniques
Authors: González José A. , Abascal Ramón
Published: October 2002

This work presents a new approach to the transient rolling contact of two‐dimensional elastic bodies. A solution will be obtained by minimizing a general B‐differentiable function representing the equilibrium equations and the contact conditions at each time step. Inertial effects are not taken into account and the boundary element method is used to compute the elastic influence coefficients of the surface points involved in contact (equilibrium equations). The contact conditions are represented with the help of variational inequalities and projection functions. Finally, the minimization problem is solved using the Generalized Newton's Method with line search. The results are compared with some example problems and the influence of discretization and integration time step on the results is discussed. Copyright © 2001 John Wiley & Sons, Ltd.
An implicit BEM formulation for gradient plasticity and localization phenomena
Authors: Benallal Ahmed , Fudoli Carlos A. , Venturini Wilson S.
Published: October 2002

The aim of this paper is to discuss a boundary element formulation for non‐linear structural problems involving localization phenomena. In order to overcome the well‐known mesh dependency observed in local plasticity, a gradient plasticity model is used. An implicit boundary element formulation is proposed and the underlying consistent tangent operator defined. This formulation is based on the classical displacement and strain integral representations combined with an integral representation of the plastic multiplier. First numerical examples are presented to illustrate the application of the method. Copyright © 2001 John Wiley & Sons, Ltd.
Implicit stress integration procedure for small and large strains of the Gurson material model
Authors: Kojic Milos , Vlastelica Ivo , Zivkovic Miroslav
Published: October 2002

The Gurson material model has broad applications in fracture mechanics, large strain deformations and failure of metals. Void growth and void nucleation are included in the model considered in this paper. An implicit stress integration procedure with calculation of the consistent tangent moduli is developed for the Gurson model. The general 3D deformations and the plane stress conditions are considered. The procedure is robust, simple and computationally efficient, suitable for use within the finite element method (FEM). It represents an application of the governing parameter method (GPM) for stress integration in case of inelastic material deformation. A large strain formulation, based on the multiplicative decomposition of the deformation gradient for material with plastic change of volume and logarithmic strains, is used in the paper. The developed numerical procedure for stress integration is applicable to small and large strains conditions. Solved examples illustrate the main features of the developed numerical algorithm. Copyright © 2002 John Wiley & Sons, Ltd.
Simulation of oscillatory wall shear stress in channels with moving indentations
Authors: Ng E. Y. K. , Siauw W. L. , Chong C. K.
Published: October 2002

The aim of this paper is to study the effects of a periodically, excited wall on the oscillatory nature of wall shear stress (WSS) and flow structures. A non‐Newtonian incompressible Navier–Stokes (N–S) solver with moving boundary was developed using Fasttalk language within the Fastflo environment. It was based on the methods of operator splitting and artificial compressibility with consideration to retain space conservation property. A two‐dimensional channel having a dimension of a human femoral artery but with arbitrarily assigned wall movement was employed. The Newtonian version of the code was validated against published work by simulation of flow in this channel with time‐varying upper and lower walls. Non‐Newtonian models (approximately 45% haematocrit) of blood flow were performed for comparison. The code was then applied to a channel with a fixed, straight, upper wall and a moving indenting lower wall. Flow separation, stagnation, and unsteadiness were characteristic flow features observed in this study. The Power Law model showed higher shear‐thinning effect at any time the frame produced the smallest vortices. The Casson model produced the highest WSS which was oscillatory in nature. When the upper wall was fixed, the indenting wall experienced almost twice as much as an induced oscillatory WSS as the rigid wall. The result also suggested that periodic wall movement is a mechanism of producing oscillatory WSS. This study may provide probable insights on atherogenesis, while the solution scheme may be useful in vascular biology. Copyright © 2002 John Wiley & Sons, Ltd.
Difference in bound rubber formation of silica and carbon black with styrene‐butadiene rubber
Authors: Choi Sung‐Seen
Published: October 2002

Formation of bound rubber is affected by the physical structure and surface chemistry of filler and the property of rubber. Variation of the bound rubber formation in styrene‐butadiene rubber compounds filled with silica and/or carbon black was studied. Influence of temperature on extraction of loosely bound rubber was also investigated. For the both silica and carbon black‐filled compounds, the bound rubber content increases with increase in the silica content ratio. The bound rubber content decreases with increasing the extracting temperature. The loosely bound rubber content of the silica‐filled compound is higher than that of the carbon black‐filled one. Activation energy for the extraction of the unbound and loosely bound rubbers becomes higher as the total filler content increases. The activation energy of the silica‐filled compound is higher (almost double the value) than for the carbon black‐filled one. Copyright­© 2002 John Wiley & Sons, Ltd.
The boundaries of cellular pathology: how pathologists see their clinical role
Authors: Jenkins David , Philips Zoë , Grisaffiî Kate , Whynes David K.
Published: October 2002

There has been much recent public attention on the effects of the practices of cellular pathology on patients and their relatives. It is important to establish clearly pathologists' views about their professional relationships to clinicians and patients. A national postal questionnaire survey was performed to investigate how cellular pathologists perceive their role in clinical practice and whether there are important differences between different groups of pathologists. Responses were received from 773 pathologists, of whom 167 were trainees. On the basis of responses to 25 attitude statements, it appears that the profession shares a core belief that pathologists are clinicians rather than scientists and sees diagnosis as its main clinical responsibility. However, the role that each pathologist feels clear about differs significantly between pathologists, with a stronger consensus over function, responsibility, and professional image than on the clinical practice of pathology, job satisfaction, and the impact of technological change. Academic activities are a minority interest, although academic pathologists express better job satisfaction and more radical views of professional practice. Young trainees are more likely to work in teaching hospitals, to be female, to have trained outside the UK, and to have had experience in other specialities. They have, however, a more restricted view of the clinical role of pathology than accredited pathologists. Most cellular pathologists see themselves as clinicians with a special role in diagnosis, but how this is interpreted and the extent to which pathologists involve themselves in clinical decision‐making is inconsistent. This professional dilemma should be addressed by research to obtain more systematic knowledge of the clinical impact of cellular pathology and especially the ill‐defined links between diagnosis and clinical decision‐making. Copyright © 2002 John Wiley & Sons, Ltd.