bluuebunny/crossref_metadata_2025 huggingface dataset:
In‐situ product removal to enhance the yield of biocatalytic reactions with competing equilibria: α‐glucosidase catalysed synthesis of disaccharides
Authors: Ahmed Farjad , Stein Andreas , Lye Gary J
Published: August 2002

Transglycosylations are an important class of enzyme‐catalysed reaction that occur in most living organisms and which are finding increasing application for the synthesis of therapeutic compounds. Compared with other bioconversion processes, however, they generally suffer from low product yields. This is due to the fact that in aqueous environments water is able to undergo a nucleophilic attack of the enzyme–substrate complex, increasing the rate of the competing hydrolysis reaction. The equilibrium yield of such reactions is consequently only around 10% (w/w). Here, the potential of applying in‐situ product removal (ISPR), with the boronate‐containing affinity resin Affi‐Gel® 601, to the α‐glucosidase mediated conversion of phenyl α‐D‐glucoside to phenyl α‐maltoside has been examined. ISPR can increase the product yield from such kinetically‐controlled reactions by removing the product from the bulk aqueous phase as soon as it is formed. In this way the competing hydrolysis reaction can be prevented and conversions potentially driven to completion. Initial experiments revealed that the optimum pH of the α‐glucosidase reaction in water–acetonitrile mixtures was between 5.5 and 6.5, whereas the optimum pH for binding of the product to the Affi‐Gel® 601 resin was between 8.0 and 8.5. Despite having to compromise on both the optimal conditions for glucosidation and for binding, an increase in product yield of 25% (w/w) was still possible following the implementation of ISPR at pH 8 in an aqueous medium containing 50% (v/v) acetonitrile. Similar results were found with the β‐galactosidase catalysed synthesis of phenyl α‐galactobiose, indicating the potentially generic nature of the ISPR methodology. While these initial results are promising, they indicate the need for more highly selective resins for carbohydrate adsorption (with higher capacities) if further increases in product yield are to be obtained.

© 2001 Society of Chemical Industry
Sonographic detection of secondary MALT lymphoma of the submandibular gland
Authors: Matsushita Tsuyoshi , Takashima Shodayu , Takayama Fumiyoshi , Momose Mitsuhiro , Wang Jichen , Ishiyama Tetsuya
Published: August 2002

This report describes a case of mucosa‐associated lymphoid tissue (MALT) lymphoma of the lacrimal glands that recurred in the submandibular salivary glands. Gray‐scale sonography showed small hypoechoic nodules, measuring less than 0.5 cm in diameter, in both submandibular glands. The echogenicity and echotexture of the rest of the submandibular glands and of the parotid glands was normal. Power Doppler sonography revealed increased vascularity within the nodules. A sonographically guided aspiration biopsy of the nodules revealed MALT lymphoma. Secondary MALT lymphoma should be considered in the presence of multiple small hypoechoic nodules in the salivary glands in patients with a history of MALT lymphoma at another location. © 2001 John Wiley & Sons, Inc. J Clin Ultrasound 29:462–465, 2001.
Contrast‐Enhanced endosonography for the diagnosis of anal and anovaginal fistulas
Authors: Sudoł‐Szopińska Iwona , Jakubowski Wiesław , Szczepkowski Marek
Published: August 2002

Purpose

We assessed whether contrast‐enhanced anal endosonography (AES) with hydrogen peroxide improves the identification of anal fistulas and their internal openings compared with non‐contrast AES.

Methods

The study group comprised 12 patients who had various types of anal fistulas with visible external openings. AES was performed before and about 15 seconds after injection of 1 ml of 3% hydrogen peroxide into the fistula tract through the external opening.

Results

Both contrast and non‐contrast AES revealed 7 transsphincteric, 2 intersphincteric, 1 suprasphincteric, and 2 anovaginal fistulas. Simple tracts were found in 8 cases and complex tracts in 4 cases on non‐contrast AES. Contrast‐enhanced AES revealed 9 simple and 3 complex fistulas. One fistula that appeared complex on the non‐contrast study appeared simple after contrast agent administration. Contrast‐enhanced AES demonstrated more internal openings than non‐contrast AES did. Surgery confirmed 11 of the fistulas; an internal opening could not be located surgically for the other tract.

Conclusions

Contrast‐enhanced AES appears to be superior to non‐contrast AES in the preoperative assessment of anal and anovaginal fistulas and in demonstrating and locating their internal openings. © 2002 Wiley Periodicals, Inc. J Clin Ultrasound 30:145–150, 2002; DOI 10.1002/jcu.10042
Cytochemical study of Streptococcus agalactiae and macrophage interaction
Authors: Teixeira Cristina Ferreira , Azevedo Neide Lemos , Carvalho Técia Maria Ulisses , Fuentes Jemima , Nagao Prescilla Emy
Published: August 2002

Light and electron microscopy were used to analyse the process of interaction of Streptococcus agalactiae (serotypes Ia, III, and V) with resident and activated mouse peritoneal macrophages. Transmission electron microscopy showed that adherence of the S. agalactiae serotype Ia, but not III and V serotypes, to the surface of activated macrophages triggers the respiratory oxidative burst as revealed by the presence of reduced nicotinamide adenine dinucleotide (phosphate) [NAD(P)H]‐oxidase in the phagocytic vacuoles. Fusion of macrophage lysosomes with bacteria‐containing phagocytic vacuoles was observed in macrophages treated with Lucifer yellow as well as by localization of acid phosphatase for all serotypes. Microsc. Res. Tech. 54:254–259, 2001. © 2001 Wiley‐Liss, Inc.
Energy and water conservation in frozen vs. supercooled larvae of the goldenrod gall fly, Eurosta solidaginis (fitch) (Diptera: Tephritidae)
Authors: Irwin Jason T. , Lee Richard E.
Published: August 2002

Insects that tolerate severe cold during winter may either supercool or tolerate ice forming within the tissues of the body. To compare the relative advantages of freezing and supercooling, we measured rates of CO2 production and water loss in frozen and supercooled goldenrod gall fly larvae (Eurosta solidaginis). As an important first step, we measured the time required for ice content and metabolic rate to stabilize upon freezing. Ice content stabilized after only three hours of freezing at –5°C, whereas CO2 production required 12 hours to stabilize. Subsequent experiments found that freezing greatly reduced both water loss and metabolic rate. Comparisons of supercooled and frozen larvae at –5°C indicated that CO2 production fell 47% with freezing and water loss decreased 35%. As temperature decreased to –10 and –15°C, CO2 production fell exponentially and was no longer detectable at –20°C with our measurement system. Our results demonstrate that freezing significantly reduces energy consumption during the winter and may therefore improve winter survival and spring fecundity. The advantages of freezing over supercooling would drive selection toward insect freeze tolerance and also toward higher supercooling points to increase the duration of freezing each winter. J. Exp. Zool. 292:345–350, 2002. © 2002 Wiley‐Liss, Inc.
Utilisation of nutrients by embryos of the enigmatic Australian viviparous skink Niveoscincus coventryi
Authors: Thompson Michael B. , Stewart James R. , Speake Brian K. , Russell Kylie J. , McCartney Ruth J.
Published: August 2002

The Eugongylus species group of Australian lygosomine skinks provides an unparalleled opportunity to study the evolution of placentotrophy. Viviparity and placentotrophy have evolved in two lineages, currently recognised as the genera Pseudemoia and Niveoscincus. The genus Niveoscincus is important because it is the only lineage of squamates in which variation in placental morphology and in the pattern of embryonic nutrition is known. Niveoscincus coventryi has the least complex placental morphology among species currently assigned to the genus. We quantified the net uptake of nutrients across the placenta of N. coventryi for comparison with other species in the genus and with other viviparous and oviparous lizards. The pattern of embryonic nutrition of N. coventryi is similar to other viviparous lizards with simple placentae in that there is no net uptake of dry matter during development but there is a net uptake of water, calcium, potassium, and sodium. There is no net uptake of lipid, nitrogen (an index of protein), or magnesium. We conclude that N. coventryi is predominantly lecithotrophic. Further, if N. coventryi is the sister taxon to Tasmanian Niveoscincus, then the distribution of patterns of embryonic nutrition among members of this clade suggests that the evolution of placentotrophy occurred during radiation of this lineage in Tasmania. J. Exp. Zool. 290:291–298, 2001. © 2001 Wiley‐Liss, Inc.
Circuits through prescribed vertices in k‐connected k‐regular graphs
Authors: Häggkvist Roland , Mader Wolfgang
Published: August 2002

We show that every set of $k+\lfloor{1\over 3}\sqrt{k}\rfloor$ vertices in a k‐connected k‐regular graph belongs to some circuit. © 2002 John Wiley & Sons, Inc. J Graph Theory 39: 145–163, 2002
Domination in planar graphs with small diameter*
Authors: Goddard Wayne , Henning Michael A.
Published: August 2002

MacGillivray and Seyffarth (J Graph Theory 22 (1996), 213–229) proved that planar graphs of diameter two have domination number at most three and planar graphs of diameter three have domination number at most ten. They also give examples of planar graphs of diameter four having arbitrarily large domination numbers. In this paper we improve on their results. We prove that there is in fact a unique planar graph of diameter two with domination number three, and all other planar graphs of diameter two have domination number at most two. We also prove that every planar graph of diameter three and of radius two has domination number at most six. We then show that every sufficiently large planar graph of diameter three has domination number at most seven. Analogous results for other surfaces are discussed. © 2002 Wiley Periodicals, Inc. J Graph Theory 40: 1–25, 2002
Small odd cycles in 4‐chromatic graphs*
Authors: Jiang Tao
Published: August 2002

It is shown that every 4‐chromatic graph on n vertices contains an odd cycle of length less than $2\sqrt {n}\,+3$. This improves the previous bound given by Nilli [J Graph Theory 3 (1999), 145–147]. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 115–117, 2001
On the Thomassen's conjecture*
Authors: Li Jianping
Published: August 2002

C. Thomassen proposed a conjecture: Let G be a k‐connected graph with the stability number α ≥ k, then G has a cycle C containing k independent vertices and all their neighbors. In this paper, we will obtain the following result: Let G be a k‐connected graph with stability number α = k + 3 and C any longest cycle of G, then C contains k independent vertices and all their neighbors. This solves Thomassen's conjecture for the case α = k + 3. © 2001 John Wiley & Sons, Inc. J Graph Theory 37: 168–180, 2001
Synthesis of 11C‐labelled acamprosate for PET studies
Authors: Courtyn Jan , Goethals Patrick , Eycken Johan Van der , Dams Richard
Published: August 2002

A method for labelling acamprosate (calcium N‐acetyl homotaurinate), an anti‐craving compound for ethanol, with 11C, has been developed for in vivo studies with positron emission tomography (PET). The synthesis was based on the acylation of homotaurinate using [11C]acetyl chloride as the labelling agent. Reversed‐phase HPLC in highly aqueous mobile phase conditions was used for product purification. The radiochemical yield achieved was about 1.14 GBq (31 mCi) with a specific radioactivity of 8.14 GBq/µmol (220 mCi/µmol). For the identification of 11C‐radioactivity and determination of specific radioactivities, HPLC and 1H‐NMR were used. Copyright © 2001 John Wiley & Sons, Ltd.
Arterial wall MRI characteristics are associated with elevated serum markers of inflammation in humans
Authors: Weiss Clifford R. , Arai Andrew E. , Bui Minh N. , Agyeman Kwabena O. , Waclawiw Myron A. , Balaban Robert S. , Cannon Richard O.
Published: August 2002

Inflammation contributes to atherosclerosis, but assessment in humans is largely restricted to measurement of markers in blood. We determined whether MRI properties of large arteries were associated with markers of inflammation in serum. Double inversion recovery, fast spin‐echo images of the common carotid arteries and infrarenal aorta were obtained at 1.5 T both before and after gadolinium‐DTPA (0.1 mmol/kg) in 52 subjects ≥40 years of age, 17 of whom had no risk factors for atherosclerosis and thus served as controls. Twenty‐two study participants had increases in wall thickness (14), T2‐weighted signal intensity (11), and/or contrast enhancement values (7) that were >2 standard deviations (SDs) from control group mean values. Ten subjects in this group had evidence of focal plaques in the carotids (5) and/or aorta (6). Compared with the remaining 30 subjects, these 22 had significantly higher levels of interleukin‐6 (3.53 ± 2.46 vs. 1.97 ± 1.37 pg/mL, P = 0.004), C‐reactive protein (0.56 ± 0.98 vs. 0.30 ± 0.52 mg/dL, P = 0.019), vascular cell adhesion molecule‐1 (572 ± 153 vs. 471 ± 130 ng/mL, P = 0.012), and intercellular adhesion molecule‐1 (244 ± 80 vs. 202 ± 45 ng/mL, P = 0.015), and nonsignificant differences in levels of E‐selectin (46.1 ± 18.9 vs. 42.3 ± 11.3 ng/mL, P = 0.369). Thus, MRI characteristics of the aorta and carotid arteries were associated with elevated serum markers of inflammation, frequently in the absence of definite atheroma. MRI of large arteries may provide a new approach to investigate the contribution of inflammation to atherogenesis. J. Magn. Reson. Imaging 2001;14:698–704. © 2001 Wiley‐Liss, Inc.
Electron ionization‐induced fragmentation of 3‐cyclopropanospiro and 3‐cyclobutanospiro derivatives of Benzo‐ and pyridosultams
Authors: Danikiewicz Witold , Wojciechowski Krzysztof , Kosiński Szymon , Olejnik Marian
Published: August 2002

Electron ionization‐induced fragmentations of 3‐cyclopropanospiro and 3‐cyclobutanospiro derivatives of selected benzo‐ and pyridosultams were studied and compared with the thermal decomposition of these compounds. 3‐Cyclopropanospirobenzosultams and the corresponding pyridosultams were found to be thermally stable up to 400 °C. At higher temperatures they eliminate an SO2 molecule yielding several dimethylindole derivatives together with other isomeric compounds. Loss of SO2 is also the main fragmentation process of the molecular ions of these compounds with the exception of the 4‐NO2 derivative, for which elimination of CH2O is observed. 3‐Cyclobutanospirobenzosultams and ‐pyridosultams eliminate SO2 on heating above 200 °C, yielding the corresponding 2‐aryl‐1,3‐butadienes. Under EI conditions expulsion of SO2 from the molecular ions is also observed. However, elimination of C2H4 is the dominant process except for the 5‐OCH3 derivative. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of molecular mass distribution of silicone oils by supercritical fluid chromatography, matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry and their off‐line combination
Authors: Chmelík Josef , Planeta Josef , Řehulka Pavel , Chmelík Josef
Published: August 2002

An Erratum has been published for this article in Journal of Mass Spectrometry 37(3) 2002; 343.

Silicone oil samples were characterized by supercritical fluid chromatography (SFC), matrix‐assisted laser desorption ionization–time‐of‐flight mass spectrometry (MALDI–TOF MS), and their off‐line combination. SFC was used to separate samples of silicone oils on micropacked capillary columns. The fractions for the identification studies were obtained from SFC runs at defined time intervals, when the restrictor was pulled out from the chromatographic flame ionization detector (FID) and inserted into a glass vial with acetone. MALDI–TOF MS was used for the identification of individual oligomers in the fractions separated. The molecular mass distributions determined based on SFC and MALDI–TOF MS measurements were compared. From this comparison, it follows that the results are in good agreement. However, certain differences were observed: MALDI–TOF MS was capable of detecting somewhat larger oligomers than the SFC‐FID, but the lower molecular mass oligomers were not present in the MALDI spectra. Differences in the region of lower molecular masses can be explained by evaporation of the more volatile low molecular mass oligomers resulting from heating of the sample during the MALDI–TOF MS measurements as a result of the absorption of the laser shot energy. The fact that no high mass discrimination effects of the MALDI–TOF MS measurements, compared with SFC, were observed is very promising for further applications of MALDI–TOF MS in characterizing synthetic polymers of moderate polydispersity. Copyright © 2001 John Wiley & Sons, Ltd.
Determination of regioselectivity in ring opening of tert‐butylaziridinones by a combination of 15N labeling and electrospray ionization‐ion trap mass spectrometry
Authors: Talaty E. R. , Van Stipdonk M. J. , Hague M. J. , Provenzano F. A. , Boese C. A.
Published: August 2002

The ring opening of 1,3‐di‐tert‐butylaziridinone by tert‐butylamine and aniline was investigated by using electrospray ionization and collision‐induced dissociation in an ion trap mass spectrometer in conjunction with 15N labeling of the two amine nucleophiles. Using the MSn capabilities of the ion trap instrument, we were able to monitor the retention of the 15N label through successive fragmentation steps. Both amines exhibited a remarkable degree of selectivity in that they both cleaved exclusively the 1,3‐bond (the alkyl–nitrogen bond). This result is in contrast to that obtained previously with methylamine, which cleaved just the opposite bond, namely, the 1,2‐bond (the acyl–nitrogen bond). These contrasting results could not have been predicted by previously published guidelines. Copyright © 2001 John Wiley & Sons, Ltd.
Differentiation of betamethasone and dexamethasone using liquid chromatography/positive electrospray tandem mass spectrometry and multivariate statistical analysis
Authors: Antignac Jean‐Philippe , Le Bizec Bruno , Monteau Fabrice , Andre François
Published: August 2002

Betamethasone and dexamethasone are two corticosteroids differing in the stereoisomery of their C‐16 methyl group. These two compounds are imperfectly separated by reversed‐phase liquid chromatography and their mass spectra are very similar, leading to a difficult unambiguous identification according to European criteria. A method is proposed for differentiating betamethasone and dexamethasone using liquid chromatography/tandem mass spectrometry and multivariate statistical analysis. Multiple analysis of variance was used for the justification and the selection of diagnostic ions. Principal component analysis permitted the suitability of the approach to be tested on a large number of samples. Discriminant factorial analysis was finally performed to build a decisional model based on the six most significant ions. This novel utilization of mass spectrometric data appeared efficient for the unambiguous identification of the target analytes in urine samples. Copyright © 2001 John Wiley & Sons, Ltd.
Continuous flow isotope ratio mass spectrometry for the measurement of nanomole amounts of 13CO2 by a reverse isotope dilution method
Authors: Guitton J. , Grand F. , Magat L. , Désage M. , Francina A.
Published: August 2002

A simple method for the determination of nanomole amounts of 13CO2 generated from an in vitro reaction is reported. The incubation medium contains a known amount of unlabeled sodium bicarbonate and the gaseous 13CO2 enriches the atmosphere upon which a measurement of the isotopic enrichment (13CO2/12CO2) is made corresponding to a reverse isotope dilution. The quantification of the 13CO2 was performed by gas chromatography/isotope ratio mass spectrometry. This assay was validated in terms of linearity, accuracy and precision using three different substrates which produce 13CO2 either by enzymatic reaction [13C]urea, sodium [13C]formate) or by chemical reaction (sodium [13C]bicarbonate). Four calibration curves were tested for each 13C‐labeled substrate, allowing the quantification of 13CO2 from 25 pmol to 150 nmol. The dynamics of the assay were obtained as a function of the quantity of unlabeled sodium bicarbonate added to each sample. Copyright © 2001 John Wiley & Sons, Ltd.
Multicenter randomized study comparing initial daily induction with high dose lymphoblastoid interferon vs. standard interferon treatment for chronic hepatitis c
Authors: Diago Moisés , Suárez Dolores , García‐Villarreal Luis , Castro Angeles , Domínguez Agustín , Pardo Margarita , del Olmo Juan A. , Pérez‐Hernández Francisco , Aguilar José , Quiroga Juan Antonio , Carreño Vicente
Published: August 2002

One hundred fifty‐five chronic hepatitis C patients were assigned at random to receive natural lymphoblastoid interferon (IFN)α‐n1, s.c., for 13 months in one of three treatment regimens: initial daily induction with 10 million units (MU) followed (group 1, n = 50) or not (group 2, n = 52) by 1 month of rest and then three times weekly 10 MU (2 months), 5 MU (2 months), and 3 MU (8 months); group 3 (n = 53) received tiw 5 MU (2 months) followed by 3 MU (11 months). By intention‐to‐treat analysis, ALT normalization at completion of treatment was greater in patients who received continuous IFNα‐n1 therapy with initial daily induction (group 2: 24/52, 46%) compared with those given intermittent therapy with initial daily induction (group 1: 17/50, 34%) and those who received standard IFNα‐n1 therapy (group 3, 18/53, 34%; P not significant). The sustained ALT response was 26%, 27% and 21% and the sustained virological response was 20%, 27%, and 19%, in groups 1, 2, and 3, respectively. A trend was observed towards a higher biochemical and virological end‐of‐treatment response in patients given induction therapy (17%) compared with standard therapy (6%, P  =  0.053). Sustained biochemical and virological responses were 20%, 27%, and 17% in groups 1, 2, and 3, respectively. Platelet and leukocyte counts decreased following daily high‐dose treatment and remained low until therapy cessation (P < 0.001). The data suggest that daily s.c. induction with 10 MU IFNα‐n1 followed by intermittent or continuous maintenance therapy for 1 year does not improve the results achieved with the standard 1‐year IFNα course in the treatment of chronic hepatitis C patients. J. Med. Virol. 64:460–465, 2001. © 2001 Wiley‐Liss, Inc.
Akt activity in presenilin 1 wild‐type and mutation transfected human SH‐SY5Y neuroblastoma cells after serum deprivation and high glucose stress
Authors: Vestling Monika , Wiehager Birgitta , Tanii Hisashi , Cowburn Richard F.
Published: August 2002

The majority of early‐onset familial Alzheimer disease cases are caused by mutations in the genes encoding presenilin 1 (PS1) and presenilin 2 (PS2). Presenilin mutations have been hypothesised to cause Alzheimer disease either by altering amyloid precursor protein metabolism or by increasing the vulnerability of neurons to undergo death by apoptosis. We showed previously that PS1 exon 9 deletion (PS1 ΔE9) and L250S mutations predispose SH‐SY5Y neuroblastoma cells to high glucose stress‐induced apoptosis and that the anti‐apoptotic effect of insulin‐like growth factor I (IGF‐I) is compromised by these mutations. The present study investigates whether the susceptibility of PS1 mutation transfected SH‐SY5Y cells to undergo apoptosis is likely due to a downregulation of Akt/protein kinase B (Akt), a key intermediate in the phosphatidylinositol 3 (PI3)‐kinase arm of the IGF‐I signaling pathway. We used two methods to determine the regulation of Akt in response to the pro‐apoptotic stimuli of serum deprivation and high glucose stress, as well as treatment with IGF‐I. We also looked at the phosphorylatiom state of GSK‐3β at Ser9. Using a kinase assay with immunoprecipitated Akt, we detected an increased Akt activity in PS1 L250S cells at 1 hr after the combination of 20 mM glucose plus 10 nM IGF‐I, when compared to the other cell types. This effect, however, was transient in that no mutation related differences were seen at either 6‐ or 24‐hr post‐treatment. Immunoblotting for Phospho‐Akt as a ratio of total Akt, as well as for GSK‐3β phosphorylated at Ser9 revealed no apparent between cell type and treatment differences. This data strongly indicates that PS1 wt and mutant cells show no major differences in the pattern of Akt regulation after exposure to the pro‐apoptotic stimuli of either serum deprivation or high glucose stress, or treatment with IGF‐I. It is suggested that another component of IGF‐I signaling is likely disrupted in these cells to increase their vulnerability to undergo death by apoptosis. J. Neurosci. Res. 66:448–456, 2001. © 2001 Wiley‐Liss, Inc.
Bergmann glial cells form distinct morphological structures to interact with cerebellar neurons
Authors: Grosche Jens , Kettenmann Helmut , Reichenbach Andreas
Published: August 2002

It is well established that Bergmann glial cells closely interact with neuronal elements in the molecular layer of the cerebellum. We reconstructed dye‐labeled Bergmann glial cells from electron microscopic serial sections and identified their contact sites with neurons as “glial microdomains“ (Grosche et al. [1999] Nature Neurosci. 2:139–143). In the present paper we describe these structures in more detail, and show that 1) immature Bergmann fibers up to postnatal day 7 are smooth and lack appendages but contain several large mitochondria at sites where the first indications of growing side branches are observed; 2) Bergmann fibers from cerebella at postnatal day 30 form two types of outgrowths, short simple thorns and longer complex appendages; 3) each of the latter (i.e., a glial microdomain) is in contact with only a few synapses and nonsynaptic neuronal excrescences; 4) every given region of the neuropil is occupied by (at least) two interdigitating glial microdomains; 5) the synaptic clefts are entirely surrounded by glial protrusions, whereas the extrasynaptic surfaces and small axons are only partially covered; and 6) many small neuronal excrescenses without vesicles are completely ensheathed by glial caps, representing novel glial‐neuronal structures of unknown function (glial thimbles). Computational modelling of the microdomains indicates that each is electrotonically independent of the stem process from which it arises, as well as of neighbouring domains. We assume that the glial microdomain is a morphological unit to compartimentalize ensembles of synapses, serving to synchronize local synaptic activity. © 2002 Wiley‐Liss, Inc.
Gap junctional communication and connexin expression in cultured olfactory ensheathing cells
Authors: Barnett Susan C. , Thompson Russell J. , Lakatos Andras , Pitts John
Published: August 2002

The olfactory ensheathing cell (OEC) is a unique glial cell able to support neurite outgrowth in the CNS throughout life. The OEC has been described as having both Schwann cell‐like and astrocyte‐like characteristics. The purpose of this study was to compare gap junctional communication and connexin (Cx) expression in cultured olfactory ensheathing cells with both astrocytes and Schwann cells to establish which of these two cells types they most closely resemble. We examined the Cx mRNA profile of OECs, astrocytes, and Schwann cells using primers to Cx26, Cx32, Cx37, Cx43, Cx46, and Cx50. All connexins tested except Cx50 were expressed by all three cell types when initially cultured. However, we observed differences in the levels of expression of Cx32 and Cx26 between astrocytes, Schwann cells, and OECs that became pronounced with time. All three cell types show limited and variable gap junctional communication in culture as assessed by the transfer of microinjected Lucifer yellow. OECs had limited coupling compared with Schwann cells and astrocytes, although the extent of the dye spread through OECs was more comparable to that seen with Schwann cells than astrocytes. Thus, OECs display a profile of Cx expression that more closely resembles the Cx expression of Schwann cells rather than astrocytes. J. Neurosci. Res. 65:520–528, 2001. © 2001 Wiley‐Liss, Inc.
Towards chiral 1,2-naphthalocyanines: 2. Synthesis of lutetium bismacrocyclic derivatives
Authors: NEGRIMOVSKII VOLODYA M. , BOUVET MARCEL , LUK'YANETS EVGENI A. , SIMON JACQUES
Published: August 2002

Starting from 1,2-naphthalocyanine lutetium acetate (1,2- NcLuOAc ) the unsymmetrical lutetium phthalo(naphthalo)cyanine (1,2- NcLuPc ) has been synthesized and characterized by optical absorption spectra and fast atom bombardment (FAB) mass spectrometry. 1,2-Naphthalocyanine shows several geometrical isomers, both the mixture (noted Nc ∑) and one of them ( Nc Cs ) have been used for forming the corresponding bismacrocycles. As a result the first racemic mixture of a chiral unsubstituted phthalo(naphthalo)cyanine complex has been synthesized and characterized.
Distribution of organic‐walled dinoflagellate cysts in surface sediments from transects across the Polar Front offshore southeast Greenland
Authors: Boessenkool Karin P. , Van Gelder Marie‐josé , Brinkhuis Henk , Troelstra Simon R.
Published: August 2002

The Polar Front along the southeast Greenland Margin denotes the contrasting hydrographic properties of the polar and Atlantic water masses on either side. The remains of planktonic organisms in underlying sediments are expected to reflect these contrasts. To test this, we quantitatively analysed the organic‐walled dinoflagellate cyst (dinocyst) assemblages in surface sediments from transects across the present‐day Polar Front on the southeast Greenland Margin.

Proportional differences are found between the composition of the dinocyst assemblages on either side of the Polar Front. The influence of polar water can be traced in the dinocyst record as high abundances of Algidasphaeridium? minutum and the presence of Pentapharsodinium dalei. The influence of Atlantic water is reflected in the presence of Operculodinium centrocarpum and Selenopemphix quanta. All samples include taxa from both environments, but the quantitative composition of the cyst assemblages clearly reflects the hydrographic features of the overlying surface water masses. Copyright © 2001 John Wiley & Sons, Ltd.
Ft‐SERS studies on 1,3‐thiazolidine‐2‐thione, 2,5‐dimercapto‐1,3,4‐thiadiazole and 2‐thiouracil adsorbed on chemically deposited silver films
Authors: Joy V. T. , Srinivasan T. K. K.
Published: August 2002

Adsorption of 1,3‐thiazolidine‐2‐thione (ttz), 2,5‐dimercapto‐1,3,4‐thiadiazole (dmtd) and 2‐thiouracil on a silver surface was studied by the FT‐SERS technique. The FT‐SERS spectra of all these molecules indicate dissociative adsorption on the silver surface to the corresponding thiolate ion. For ttz and 2‐thiouracil, the corresponding thiolate ions are found to adsorb to the surface through their sulfur atoms and have a perpendicular orientation on the silver surface. For dmtd, the results suggest that the dithiolate ion has two kinds of adsorption geometries depending on the concentration of the dmtd in solution. At low concentration the diothiolate ion probably adsorbs through the nitrogen atom whereas at high concentration the ion probably adsorbs through its π‐system Copyright © 2001 John Wiley & Sons, Ltd.
Emulsifying activity and emulsion stability of corn gluten meal
Authors: Wu Y Victor
Published: August 2002

Corn gluten meal with good emulsifying activity and emulsion stability may have potential in food uses. Commercial corn gluten meal from various producers had a pH around 4 and showed no emulsifying activity. Reducing the particle size to below 15 µm or increasing the pH to 6.6 (with particle size above 53 µm) did not improve the emulsifying activity. When the particle size was reduced to below 44 µm and the pH was adjusted to 6.6 or above, good emulsifying activity and good emulsion stability could be obtained. The emulsifying activities of corn gluten meals (<44 µm) from four different producers at around pH 8 ranged from 49.3 to 51.5 and the corresponding emulsion stabilities ranged from 39.7 to 49.5. There was no significant variation in emulsifying activity between pH 6.9 and 7.8 when NaOH, LiOH and KOH were used to adjust the pH, but LiOH‐ and KOH‐adjusted meal at around pH 7.8 showed better emulsion stability than NaOH‐adjusted meal. Good emulsifying activity of corn gluten meal could be obtained in NaCl solutions at sufficiently high pH. Published in 2001 for SCI by John Wiley & Sons, Ltd.
Reactivity of selected volatile organic compounds (VOCs) toward the sulfate radical (SO4−)
Authors: George Ch. , Rassy H. El , Chovelon J.‐M.
Published: August 2002

Rate constants for a series of alcohols, ethers, and esters toward the sulfate radical (SO4−) have been directly determined using a laser photolysis set‐up in which the radical was produced by the photodissociation of peroxodisulfate anions. The sulfate radical concentration was monitored by following its optical absorption by means of time resolved spectroscopy techniques. At room temperature the following rate constants were derived: methanol ((1.6 ± 0.2) × 107 M−1 s−1); ethanol ((7.8 ± 1.2) × 107 M−1 s−1); tert‐butanol ((8.9 ± 0.3) × 105 M−1 s−1); diethyl ether ((1.8 ± 0.1) × 108 M−1 s−1); MTBE ((3.13 ± 0.02) × 107 M−1 s−1); tetrahydrofuran (THF) ((2.3 ± 0.2) × 108 M−1 s−1); hydrated formaldehyde ((1.4 ± 0.2) × 107 M−1 s−1); hydrated glyoxal ((2.4 ± 0.2) × 107 M−1 s−1); dimethyl malonate (CH3OC(O)CH2C(O)OCH3) ((1.28 ± 0.02) × 106 M−1 s−1); and dimethyl succinate (CH3OC(O)CH2CH2C(O)OCH3) ((1.37 ± 0.08) × 106 M−1 s−1) where the errors represent 2σ. For the two latter species, we also measured the temperature dependence of the corresponding rate constants. A correlation of these kinetics with the bond dissociation energy is also presented and discussed. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 539–547, 2001
Bank robbery: the real losers in the 1998 Bangladesh flood
Authors: Chadwick M. T. , Soussan J. G. , Martin T. C. , Mallick D. , Alam S. S.
Published: August 2002

During July, August and September 1998, Bangladesh was subjected to the most extensive flood in living memory. At peak flood, approximately two‐thirds of the country was under water. The media showed submerged houses, drowned livestock, and women and children wading neck deep in water carrying water jars or food on their heads. Such images reinforce many people's perceptions of Bangladesh as a country incessantly subjected to devastating floods that destroy crops and cause untold misery to the nation's people. Yet, beyond this media‐generated view, there is a country where agricultural production is still the mainstay of the rural population's livelihood system. The nation's water resources, both above and below ground, provide a multitude of services to the population: water to drink and in which to bathe, fish to eat and water to irrigate crops. This paper outlines the local‐level research indicating that most rural Bangladeshis living on the central Bangladesh floodplain, view the annual monsoon flood season not as an inconvenience but as a necessity. It suggests that many people in the research areas recognize the benefits associated with extreme flood events. The 1998 flood provided plentiful amounts of fish, a staple diet and labouring work in the form of building up flood defences. It also flushed out stagnant water in ponds and pagars (open system ponds), and in time, led to a bumper harvest of rice. The research highlights the lives of those whose livelihoods are devastated by such events, describes the nature of the monsoon of 1998, analyses the effects on the community's livelihood systems and describes the nature of their coping strategies. It also suggests ways in which the government and aid agencies could better assist those whose livelihoods are most vulnerable. Copyright © 2001 John Wiley & Sons, Ltd.
Prediction of portwine stain clearance and required number of flashlamp pumped pulsed dye laser treatments
Authors: Koster Petra HL , van der Horst Chantal MAM , Bossuyt Patrick MM , van Gemert Martin JC
Published: August 2002

Background and Objective:

Portwine stain (PWS) response to flashlamp pumped pulsed dye laser (FPPDL) treatment is variable and unpredictable. Our aim was to develop a model to predict treatment outcome and the required number of treatments.

Study Design/Materials and Methods:

We hypothesized that PWS clearance decreases exponentially with the number of treatments, as a consequence of the exponential decrease of laser light fluence in human skin. Of 70 patients with a PWS in the head/neck area, the color difference between normal skin and PWS was measured with a chromameter, prior to, and at several stages during FPPDL treatment. Through the obtained values of each of the four color parameters, ΔL*, Δa*, Δb*, and ΔE, mono‐exponentially decreasing functions were fitted.

Results:

All four color parameters showed decreasing exponential functions, with decay rates that were not significantly different, and a mean R2 of 0.6, indicating a reliable fit‐quality.

Conclusions:

Our model suggests that individual prediction of treatment outcome and the required number of treatments is possible in an early stage of FPPDL treatment of PWS, in theory already after one single laser treatment. Lasers Surg. Med. 29:151–155, 2001. © 2001 Wiley‐Liss, Inc.
Two consistently deleted regions within chromosome 1p32‐pter in human non–small cell lung cancer
Authors: Chizhikov Victor , Zborovskaya Irina , Laktionov Konstantin , Delektorskaya Vera , Polotskii Boris , Tatosyan Alexander , Gasparian Alexander
Published: August 2002

Allelic losses at 1p32‐pter have been reported as frequent events in human non–small cell lung cancer (NSCLC). To further characterize the region of deletions, we studied loss of heterozygosity on a panel of 102 microdissected NSCLC samples with 20 polymorphic markers spanning 1p32‐pter. Two shortest regions of the overlap of the deletions (SROs) were found: SRO 2a (D1S417–D1S57) and SRO 2b (D1S450–D1S243). Allelic losses at either region correlated independently with advanced stage of disease and with postoperative metastasis and relapse (P < 0.05), suggesting that crucial genes in these regions are involved in NSCLC progression. Mol. Carcinog. 30:151–158, 2001. © 2001 Wiley‐Liss, Inc.
Business profitability versus social profitability: evaluating industries with externalities, the case of casinos
Authors: Grinols Earl L. , Mustard David B.
Published: August 2002

Casino gambling is a social issue, because in addition to the direct benefits to those who own and use casinos, positive and negative externalities are reaped and borne by those who do not gamble. To correctly assess the total economic impact of casinos, one must distinguish between business profitability and social profitability. This paper provides the most comprehensive framework for addressing the theoretical cost–benefit issues of casinos by grounding cost–benefit analysis on household utility. It also discusses the current state of knowledge about the estimates of both the positive and negative externalities generated by casinos. Lastly, it corrects many prevalent errors in the debate over the economics of casino gambling. Copyright © 2001 John Wiley & Sons, Ltd.
Antioxidant and other biological activities of phenols from olives and olive oil
Authors: Visioli Francesco , Poli Andrea , Gall Claudio
Published: August 2002

Olive oil is the principal source of fats in the Mediterranean diet, which has been associated with a lower incidence of coronary heart disease and certain cancers. Phenolic compounds, e.g., hydroxytyrosol and oleuropein, in extra‐virgin olive oil are responsible for its peculiar pungent taste and for its high stability. Recent findings demonstrate that olive oil phenolics are powerful antioxidants, both in vitro and in vivo, and possess other potent biological activities that could partially account for the observed healthful effects of the Mediterranean diet. © 2001 John Wiley & Sons, Inc. Med Res Rev, 22, No. 1, 65–75, 2002
Time–frequency characteristics of single‐mode fiber dispersion
Authors: Ai‐Huang Guo , Jun‐Mei Fu , Eng‐Xin Fen
Published: August 2002

Pulsed light through the different distance of a single‐mode fiber is calculated. The dispersion characteristics are analyzed by the time‐window, frequency‐window, and time–frequency planes of the Wigner–Vill distribution. Time–frequency analysis can provide more information about the dispersion and energy changes of pulsed light transmission. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 299–302, 2001.
Accurate analysis of waveguide junctions with rectangular coupling cavity
Authors: Chumachenko Vitaliy P. , Karaçuha Ertuğrul , Petrusenko Igor V.
Published: August 2002

The domain‐product technique is applied to modeling of H‐ and E‐plane loaded waveguide junctions with a rectangular connecting cavity. A specific use of the edge condition accelerates the convergence of the solution. Very high efficiency of the technique is demonstrated by the example of the right‐angle bend. The approach is also suitable for T‐junctions and cross junctions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 305–308, 2001.
A new recursion method for fiber grating analysis
Authors: Wang Zi Hua , Peng Gang‐Ding , Ankiewicz Adrian , Chu Pak L.
Published: August 2002

A new recursion method for the analysis of fiber gratings has been derived. Bragg‐matched and detuned uniform gratings and nonuniform gratings have been analyzed by using this method. The results have been compared with that by using the coupled‐mode theory and other methods. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 308–313, 2001.
Properties of high‐εr microstrip lines
Authors: Crute John R.
Published: August 2002

High‐dielectric‐constant (high‐εr) ceramic materials provide opportunities for developing ultra‐miniaturized microstrip circuits. This paper investigates the properties of high‐εr microstrip transmission lines on (Zr, Sn)TiO4 (εr=37) and BaO–PbO–Nd2O3–TiO2 (εr=88) substrates. An electromagnetic (EM) field solver is used to determine the frequency‐dependent characteristic impedance and effective dielectric constant of a range of microstrip lines up to 5 GHz. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 31: 313–314, 2001.
Accurate experimental determination of cutoff wavelengths in channel waveguides
Authors: Simos Christos , Di Bin Philippe
Published: August 2002

We present a simple experimental technique for the fast and accurate determination of the effective cutoff wavelength of the second‐order modes in channel waveguides. The technique is based on a spectral analysis of the output power when the guide is excited by even and odd field patterns alternately with the wavelength. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 14–17, 2002.
Improved tuning accuracy of fiber grating lasers using a linear variable differential transformer
Authors: Chung W. H. , Tam H. Y. , Demokan M. S. , Wai P. K. A.
Published: August 2002

A microprocessor‐controlled feedback system using a linear variable differential transformer to measure the compression of a fiber Bragg grating with a view to improve the tuning accuracy of a fiber grating laser is reported. This technique overcomes the large hysteresis of the PZT actuator normally used to compress the grating. A tuning range of about 20 nm with a readout wavelength accuracy of better than ±0.05 nm was achieved. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 37–40, 2002.
On the evaluation of the true phase of interferograms
Authors: Ahmad Falih H. , Helms Gary L. , Castellane Ray M. , Durst Bartley P.
Published: August 2002

An iterative technique that uses sine and cosine modulations along with low‐pass filtering to extract the true phase values of a carrier frequency interferogram is proposed in this paper. An illustrative example is given in which this technique is applied. Results generated from the application of this technique are compared with exact phase values, and excellent agreement between the exact and computed phase values is demonstrated. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 40–43, 2002.
Polarizability of polyhedral dielectric scatterers
Authors: Avelin Juha , Sihvola Ari
Published: August 2002

This paper presents numerical results for the dielectric polarizability of canonically shaped homogeneous scatterers: cube, tetrahedron, and octahedron. The method is based on solving the integral equation for the static scalar potential on the surface of the scatterer by the method of moments. Easy‐to‐use interpolation formulas are given for the polarizabilities as a function of the permittivity. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 60–64, 2002.
Addition effect of barium and strontium titanate on the reflectivity of ferri and ferromagnetic composites
Authors: Pinho Magali S. , Gregori Maria Luisa , Carvalho Aristóteles S. , Nunes Regina Célia R. , Soares Bluma G.
Published: August 2002

The effect of barium and strontium titanate on the microwave reflectivity properties of carbonyl–iron and doped hexaferrite in polychloroprene matrices was investigated. The electromagnetic properties of these materials were evaluated between 8 and 16 GHz. The T/R method was adopted to determine their complex permeabilities (μ*r) and permittivities (ε*r). © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 325–327, 2002.
A hybrid DWDM system based on a Fabry–Perot laser diode and an optical circulator with a fiber Bragg grating
Authors: Lee Chi‐Sen , Lu Hai‐Han
Published: August 2002

A hybrid dense‐wavelength‐division‐multiplexing (DWDM) system using a combination of a Fabry–Perot (FP) laser diode, an optical circulator (OC), and a fiber Bragg grating (FBG), as well as half‐split‐band and WDM techniques, is demonstrated. It is a four‐wavelength system, in which two wavelengths are for AM–VSB video, one wavelength is for a 256‐QAM digital signal, and one wavelength is for OC‐48 digital baseband signal transmission. © 2002 John Wiley & Sons, Inc. Microwave Opt Technol Lett 32: 390–393, 2002.
Relationship between linear light incidence and circular light incidence in single‐mode optical fibers
Authors: Min‐Ning Ji
Published: August 2002

A fundamental relation S+S=1 between output light polarization magnitudes with linear light incidence and circular light incidence is found to exist universally in single‐mode optical fibers. It is confirmed theoretically and experimentally, and is employed to analyze the SOP‐maintaining capability of a fiber. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 16–19, 2001.
Numerical modeling and experimental investigation of resonance properties of microwave capacitors
Authors: Semouchkina Elena , Cao Wenwu , Mittra Raj , Lanagan Michael
Published: August 2002

The finite‐difference time‐domain (FDTD) field simulations have been employed to visualize standing‐wave patterns in single‐layer, rectangular, planar capacitors and capacitor chips. These patterns are used for the analysis of the resonant mode types, and for the determination of the resonance frequencies. The results of simulation are experimentally verified by measuring the S‐parameter spectra. In addition, we show that the dimensions of the capacitor plates can be optimized in order to maximize the first resonant frequency of the capacitor, rendering it useful for high‐frequency applications. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 54–60, 2001.
Design criteria for increasing the bandwidth–efficiency product of GaAs p–i–n photodetectors
Authors: Torrese G. , Huynen,and I. , Vander Vorst A.
Published: August 2002

Using commercial and homemade simulation tools, this letter investigates how the geometrical and technological parameters of the p–i–n junction, particularly the p+‐ and n+‐regions, influence the electrical and optical performances of GaAs p–i–n lumped and traveling‐wave photodetectors (TWPDs). It is concluded that, for TWPDs, the electrical bandwidth and quantum efficiency can be optimized nearly separately as a function of the parameters of the p‐, i‐, and n‐regions. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 150–155, 2001.