bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractThe 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

AbstractChickpea (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

AbstractTwo 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

AbstractThe 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

AbstractThe 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

AbstractIn 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

AbstractSixteen 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

AbstractLow‐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

AbstractThe 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

AbstractA 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

AbstractAccumulation 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

AbstractBackground and ObjectivesTo 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 MethodsThis 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.ResultsUsing 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.ConclusionsScatter‐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

AbstractBackground and ObjectivesThe 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 MethodsFour 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.ResultsAfter 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.ConclusionThe 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

AbstractPrevious 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

AbstractPutaminal 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

AbstractWe 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.