bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnosis of chronic atrophic gastritis by morphometric image analysis. A new method to overcome the confounding effect of the inflammatory infiltrate
Authors: Staibano Stefania , Rocco Alba , Mezza Ernesto , De Rosa Gaetano , Budillon Gabriele , Nardone Gerardo 
Published: October 2002

AbstractThe risk of gastric cancer increases with the severity of gastric mucosal atrophy. Atrophy is a ‘loss of properly specialized glands’. These glands may be substituted by metaplastic cells and by interstitial fibrosis, or displaced by an inflammatory infiltrate. Agreement among pathologists for the diagnosis of atrophy is poor (κcoefficient < 0.4), probably because inflammatory infiltrate can confound the identification of gland loss. The aim of this study was to evaluate interstitial fibrosis by image analysis, and thereby overcoming the confounding effect of the inflammatory infiltrate. Gastric biopsies of 40 controls (20 children and 20 adults) and 111 patients with chronic atrophic gastritis were examined. Patients underwent another biopsy a year later. Gastric sections were examined by conventional histology (updated Sydney system) and image analysis to detect collagen and non‐collagen fibres. There were no significant intra‐ or inter‐operator differences in the evaluation by image analysis of fibre content in either controls or patients. In both controls and patients, the mean percentage of collagen fibres was lower in the gastric body (9%) than in the antrum (10%). In the antrum it was 14%, 17% and 20% in patients with mild, moderate and severe atrophy, respectively. A year later, histology showed that the grade of atrophy had decreased in 42%, probably due to the regression of inflammation, and increased in 10% of cases, but interstitial fibrosis (expressed as collagen fibre content) was practically unchanged. The use of image analysis of gastric biopsies appears to be a reliable method with which to measure interstitial fibrosis, even in the presence of an inflammatory infiltrate. This study highlights the difference between ‘real gastric atrophy’, where glands are replaced by collagen fibres, and ‘apparent gastric atrophy’, where glands are displaced by an inflammatory infiltrate. Copyright © 2002 John Wiley & Sons, Ltd.
Expandability of haemopoietic progenitors in first trimester fetal and maternal blood: implications for non‐invasive prenatal diagnosis
Authors: Campagnoli Cesare , Roberts Irene A. G. , Kumar Sailesh , Choolani Mahesh , Bennett Phillip R. , Letsky Elizabeth , Fisk Nicholas M. 
Published: October 2002

AbstractObjectivesSelective amplification of rare fetal cells in maternal blood is a potential strategy for non‐invasive prenatal diagnosis. We assessed the proliferative potential of first trimester fetal progenitors compared to maternal ones.MethodsFetal and maternal haemopoietic progenitors were cultured separately and in two model mixtures: (i) co‐cultures of male fetal nucleated cells mixed with maternal nucleated cells and (ii) co‐cultures of malefetal CD34+ cells with maternal CD34+ cells. Cell origin was detected by X‐Y fluorescence in situ hybridisation (FISH)ResultsThe frequency of haemopoietic progenitors in first trimester fetal blood (predominantly CFU‐GEMM) differed from those in peripheral blood from pregnant women (predominantly BFU‐e). First trimester haemopoietic progenitors formed larger colonies (p=0.0001) and their haemoglobinisation was accelerated compared to those of maternal origin (p<0.001). CD34+ fetal haemopoietic progenitor cells could be expanded four times more than their maternal counterparts (median 235.8‐fold, range 174.0–968.0 vs 71.9‐fold, range 41.1–192.0; p=0.003). While selective expansion of fetal cells was not observed in the mononuclear cell model, the CD34+ cell rare event mixtures produced a 463.2‐fold (range 128.0–2915.0) expansion of fetal cells.ConclusionSelective expansion of first trimester fetal haemopoietic progenitors may be useful for amplifying fetal cells from maternal blood. Copyright © 2002 John Wiley & Sons, Ltd.
Uniparental disomy in fetuses diagnosed with balanced Robertsonian translocations: risk estimate
Authors: Silverstein Shira , Lerer Israela , Sagi Michal , Frumkin Ayala , Ben‐Neriah Ziva , Abeliovich Dvorah 
Published: October 2002

AbstractForty‐two fetuses with non‐homologous Robertsonian translocations were analyzed for uniparental disomy (UPD). One fetus with a de novo translocation t(13q;14q) had maternal isodisomy of chromosome 14. In a summary of the published data (including the present study), 315 cases were analyzed for UPD after prenatal diagnosis of balanced Robertsonian translocations, of these two fetuses had UPD, giving a risk estimate of 0.65% (CI 0.2–2.3). This risk justifies the recommendation of UPD analysis in fetuses diagnosed prenatally with Robertsonian translocations, with the emphasis on the chromosomes known to contain imprinted genes, such as 14 and 15. We also discuss the possibility of UPD in offspring of Robertsonian translocation carriers with normal karyotype. Based on the risk for UPD in fetuses with Robertsonian translocation we suggest to test these fetuses for UPD and to do so on amniocytes rather than chorionic villi when the risk for unbalanced karyotype is ∼1%, comparable to the risk for UPD. Copyright © 2002 John Wiley & Sons, Ltd.
First trimester screening with free β‐hCG, PAPP‐A and nuchal translucency in pregnancies conceived with assisted reproduction
Authors: Orlandi Francesco , Rossi Cinzia , Allegra A. , Krantz David , Hallahan Terrence , Orlandi Emanuela , Macri James 
Published: October 2002

AbstractObjectiveTo evaluate the effect of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) on free beta‐human chorionic gonadotrophin (β‐hCG), pregnancy‐associated plasma protein A (PAPP‐A) and nuchal translucency (NT).MethodsFirst trimester maternal dried whole blood specimens from 74 singleton pregnancies (32 by IVF and 42 by ICSI) and 30 twin pregnancies (16 by IVF and 14 by ICSI) in which conception was achieved with assisted reproduction techniques were matched with five controls resulting in 370 singleton controls and 150 twin controls. NT was measured using the Fetal Medicine Foundation protocol. Free β‐hCG, PAPP‐A and NT levels were compared between the IVF and control groups and between the ICSI and control groups using the Mann‐Whitney U test.ResultsIn singleton pregnancies, the only significant difference was a 21% (95% CI: −35%–−7%) reduction in PAPP‐A in IVF cases. In twin pregnancies, the only significant difference was a 12% (95% CI: −34%–−3%) reduction in NT in IVF cases. In singleton pregnancies, the false‐positive rate for Down syndrome screening was 1.4% and 1.9% greater for the IVF and ICSI groups, respectively, compared to controls for a general screening population.ConclusionsPatients undergoing assisted reproduction techniques should be counseled about the possibility of increased false‐positive rates. Larger studies are needed to confirm this observation and to develop appropriate adjustment factors to reduce false‐positive rates. Copyright © 2002 John Wiley & Sons, Ltd.
Thermosensitive and hydrolysis‐sensitive poly(organophosphazenes)
Authors: Lee Bae Hoon , Lee Young Moo , Sohn Youn Soo , Song Soo‐Chang 
Published: October 2002

AbstractThe lower critical solution temperature (LCST) properties and hydrolytic behaviour of thermosensitive biodegradable polyphosphazenes with monomethoxy‐poly(ethylene glycol), glycine ethyl ester and depsipeptide ethyl esters substituents have been studied. All the polymers synthesized show LCST properties. The LCSTs of the polymers are affected by the composition of the polymers and increase with the degradation of the polymers in aqueous solution. The higher content of depsipeptide ethyl esters in the polymers accelerates the LCST change and the degradation of the polymers in aqueous solution. Most polymers synthesized have half‐lives of less than 10 days in neutral solution.© 2002 Society of Chemical Industry
Blends of natural rubber and polyurethane latices studied by1H wideline and13C MAS solid‐state NMR
Authors: Ricardo Nágila M P S , Lahtinen Mika , Price Colin , Heatley Frank 
Published: October 2002

Abstract1H wideline and13C magic‐angle spinning NMR have been used to study the morphology and dynamics of latex‐cast and solution‐cast film blends of natural rubber (NR) and a polyurethane (PU) based on poly(ϵ‐caprolactone) diol and isophorone di‐isocyanate.1HT1andT1ρrelaxation times have been measured, and the extent of interpenetration of the NR and PU constituents has been monitored using the Goldman–Shen technique. The NMR spectra and relaxation properties indicated that the NR and PI constituents largely occupy separated domains on a distance scale of >10 nm. The Goldman–Shen experiments indicated that there was slightly greater contact between NR and PU in the solution‐cast samples than in the latex‐cast. The tensile properties of the films have been measured. The tensile strength and initial Young's modulus pass through a maximum at a PU content of about 50 wt%.© 2002 Society of Chemical Industry
Gelation of a new hydrogel system ofatactic‐poly(vinyl alcohol)/NaCl/H2O
Authors: Dai Lixing , Ukai Kohshuke , Shaheen Sharif Mohammad , Yamaura Kazuo 
Published: October 2002

Abstracta‐PVA/NaCl/H2O hydrogels have been prepared by gelation of aqueousatactic‐poly(vinyl alcohol) (a‐PVA) solutions in the presence of NaCl. The gelling temperature, melting temperature and the preservation of water of the hydrogels have been measured. The effect of the addition of NaCl to the hydrogels on gelling temperature and melting temperature is marked when the NaCl concentration is over a certain value. High NaCl concentration favours high‐melting‐point hydrogels. When the NaCl concentration is high enough (such as 11%), high‐melting‐point and white turbid opaquea‐PVA/NaCl/H2O hydrogels can be prepared, regardless of the PVA concentration. Similarly, the low gelling temperature ofa‐PVA/NaCl/H2O solutions comes from low NaCl concentration, while high gelling temperature ranges from 50 to 70 °C when the NaCl concentration is 11%. In appearance, the types of syneresis ofa‐PVA/NaCl/H2O are χ‐type or a mixture of χ‐ andn‐types; water release of the hydrogels is slowed down by the addition of NaCl.© 2002 Society of Chemical Industry
Molecular selectivity of tyrosine‐imprinted polymers prepared by seed swelling and suspension polymerization
Authors: Zhang Liyong , Cheng Guoxiang , Fu Cong 
Published: October 2002

AbstractTyrosine‐imprinted microspheres have been prepared in an aqueous system by seed swelling and suspension polymerization, using trimethylolpropane trimethacrylate (TRIM), acrylamide (AM) as well as methacrylic acid (MAA), linear polystyrene and toluene as crosslinker, functional monomers, seeds and porogens, respectively. The size distribution proved to be greatly influenced by the ratio of water:TRIM (W/T) and the concentration of dispersant. When W/T was 46:1 (v/v), 4.6% (by mass) of poly(vinyl alcohol) (PVA) was used as dispersant, the molar ratios of tyrosine, MAA, AM and TRIM were 1:8:8:17, the polymer beads had the better size monodispersity, and the average size was 135 µm, while the sizes of the pores on the beads surfaces ranged from 1.25 µm to 9.0 µm. The adsorption behaviour and molecular selectivity of the beads were analysed using liquid chromatography; the results showed that the adsorption behaviour of the beads followed the rule of Langmuir, and the value of saturated absorption was 0.197 mmol g−1. The tyrosine‐imprinted polymers exhibited an inherent selectivity for tyrosine; when phenylalanine was used as the competing molecule the separation factor α was up to 1.91. However, the control polymers did not have this special molecule‐selection capability, and the relative separation factor β was about 1.82 compared with the imprinted polymers.© 2002 Society of Chemical Industry
Lesbian, gay, bisexual, and transgender college students with disabilities: A look at multiple cultural minorities
Authors: Harley Debra A. , Nowak Theresa M. , Gassaway Linda J. , Savage Todd A. 
Published: October 2002

AbstractCollege students with disabilities who are lesbian, gay, bisexual, or transgender (LGBT) represent diverse cultural minorities with multiple service needs involving disabilities, identities, and adjustment strategies. These students are usually accommodated in the college environment because of their disability while simultaneously marginalized based on their sexual orientation. This article discusses LGBT college students with disabilities as multiple cultural minorities with a focus on educational environments, institutional issues, and strategies for university personnel. © 2002 Wiley Periodicals, Inc.
Not all school dropouts are the same: Ethnic differences in the relation between reason for leaving school and adolescent substance use
Authors: Aloise‐Young Patricia A. , Chavez Ernest L. 
Published: October 2002

AbstractSeveral national studies have revealed that students choose to drop out of school for a variety of reasons. Moreover, there are ethnic differences in the reasons dropouts give for leaving school. In the present study, the relation between reason for dropping out and substance use was explored in Mexican American and non‐Hispanic White adolescents. The results revealed that for Mexican American adolescents, substance use was highest among those who left school to be with their friends and lowest among those who left for family‐related reasons. Among non‐Hispanic White adolescents, there were no significant differences in substance use as a function of reason for leaving school. For both ethnicities, nearly one‐third of the dropouts reported that their substance use was an important contributor to their decision to leave school early. The theoretical and practical implications of these findings are discussed. Recommendations are made for ways in which the reasons that dropouts give for leaving school can be used to inform school programs. © 2002 John Wiley & Sons.
Thermal and hyperbaric addition of N,N‐ and N,O‐ binucleophiles on cycloalkylidenic bromo esters
Authors: Rulev Alexandre Y. , Maddaluno Jacques 
Published: October 2002

AbstractThe thermal and high‐pressure (11 kbar) induced reaction between 2‐bromo‐2‐(cycloalkylidene)acetates and N,O‐ and N,N‐binucleophiles (such as ethylenediamines or aminoethanols) provides morpholin‐2‐ones and piperazin‐2‐ones. Thus, in contrast to simple primary amines, binucleophiles do not form spirocyclic derivatives. The expected Michael addition competes with a cascade reaction consisting of a migration of the double bond followed by the substitution of the newly established allylic halogen and a lactonization (lactamization), and eventually ended by a back‐migration of the double bond. Copyright © 2002 John Wiley & Sons, Ltd.
Interactions of chiral quinuclidin‐3‐yl benzoates with butyrylcholinesterase: kinetic study and docking simulations
Authors: Primožič Ines , Hrenar Tomica , Tomić Srđanka , Meić Zlatko 
Published: October 2002

AbstractBoth enantiomers of quinuclidin‐3‐yl benzoate (RQBz and SQBz) were synthesized in order to examine the stereoselectivity of the hydrolysis of these esters catalyzed by horse serum butyrylcholinesterase (BChE). The hydrolysis of benzoylcholine (BzCh) was also studied in order to determine the influence of the alcohol part of ­the esters upon the kinetics. The kcat value for the substrates decreased in order BzCh > RQBz (4‐fold slower) ≫­SQBz (76‐fold slower reaction). KM values determined for quinuclidinium substrates revealed that the binding affinity of RQBz (0.28 mM) is approximately 2‐fold lower than that of SQBz (0.13 mM) towards BChE. From the ratio of the enantiomeric kcat/KM values, an enantiomeric excess of 78% was calculated, indicating that the resolution of racemic quinuclidin‐3‐yl benzoate can be achieved by hydrolysis with BChE. The orientations of all the studied benzoate esters and butyrylcholine (BuCh) in the active site of human BChE were proposed by flexible ligand docking with AutoDock 3.0. Analyses of the Michaelis complexes obtained revealed that there are numerous similar close contacts in the active site. The main difference in binding of quinuclidinium and choline esters was found in the ammonium electrostatic region which includes cation–π interaction of the ammonium moiety of substrates with the indole ring ­of Trp84. The important cation–π interaction with Trp84 was lowest in the case of the S‐enantiomer of QBz, which might be the main explanation for the slowest rate of hydrolysis of that compound. Copyright © 2002 John Wiley & Sons, Ltd.
Catalysis in electron transfer reactions: facts and mechanistic insights
Authors: Fukuzumi Shunichi 
Published: October 2002

AbstractCatalysis in electron transfer reactions between electron donors and acceptors is described and the important mechanistic insight is provided by showing a number of examples of both thermal and photochemical reactions that involve metal ion‐catalyzed electron transfer processes as the rate‐determining steps. The quantitative measure of Lewis acidity of metal ions was obtained from the gzz values of ESR spectra of superoxide–metal ion complexes which vary significantly depending on the type of metal ions. Copyright © 2002 John Wiley & Sons, Ltd.
Strained hydrocarbons from cyclic diynes—preparation and reactivity
Authors: Bethke Sabine , Brand Stefan , Treptow Björn , Gleiter Rolf 
Published: October 2002

AbstractThe reaction of cyclic diynes with either CpCo(CO)2 or AlCl3 yielded strained hydrocarbons in which a Dewar benzene or a tricyclo[4.2.0.02,5]octa‐3,7‐diene frame is bridged by hydrocarbon chains. The photochemistry and thermochemistry of these species are discussed. Results of quantum chemical calculations (DFT, CASPT2) are used to discuss the thermochemistry of four different fourfold bridged tricyclo[4.2.0.02,5]octa‐3,7‐dienes. Depending on the bridging mode, either a Cope‐type rearrangement or a ring opening reaction is preferred. Copyright © 2002 John Wiley & Sons, Ltd.
Thermo‐solvatochromism in aqueous alcohols: effects of the molecular structures of the alcohol and the­solvatochromic probe
Authors: Antonious Maged S. , Tada Erika B. , Seoud Omar A. El 
Published: October 2002

AbstractThermo‐solvatochromism of 2,6‐diphenyl‐4‐(2,4,6‐triphenylpyridinium‐1‐yl)‐1‐phenolate, 2,6‐dichloro‐4‐(2,4,6‐triphenylpyridinium‐1‐yl) phenolate and 1‐methylquinolinium‐8‐olate in the temperature range 10–45 °C was studied in mixtures of water with methanol, ethanol, 1‐propanol, 2‐propanol, 2‐methyl‐2‐propanol, 2‐methoxyethanol and 1,2‐ethanediol. Plots of the solvent polarity parameter, ET in kcal mol−1, versus mole fraction of water in the binary mixture, χw, indicated that all probes are preferentially solvated by the alcohol. Thermo‐solvatochromic data for aqueous methanol, 2‐methoxyethanol and 1,2‐ethanediol were fitted to a simple solvent‐exchange model, in which water substitutes alcohol in the probe solvation micro‐sphere. Data for the remaining alcohols required a more elaborate model, where water and water–alcohol complex substitute alcohol and/or water in the probe solvation micro‐sphere. A temperature increase causes gradual desolvation of the probe, due to a decrease in the H‐bonding abilities of both components of the binary mixture. Copyright © 2002 John Wiley & Sons, Ltd.
Solute–solvent and solvent–solvent interactions in the preferential solvation of Brooker's merocyanine in binary solvent mixtures
Authors: da Silva Domingas C. , Ricken Ingrid , Silva Marcos A. do R. , Machado Vanderlei G. 
Published: October 2002

AbstractThe ET polarity values of 4‐[(1‐methyl‐4(1H)‐pyridinylidene)ethylidene]‐2,5‐cyclohexadien‐1‐one, better known as Brooker's merocyanine, were collected in binary mixtures comprising a non‐protic [acetonitrile, dimethyl sulfoxide (DMSO) and acetone] and a protic (water, methanol, ethanol, propan‐2‐ol and butan‐1‐ol) solvent. Data referring to mixed systems involving water and alcohols (methanol, ethanol, propan‐2‐ol and 2‐methylpropan‐2‐ol) were also collected. These data were used in the investigation of the preferential solvation of the dye. Each solvent system was analyzed in terms of both solute–solvent and solvent–solvent interactions. These latter interactions are responsible for the synergistic effects observed for the ET parameter in many binary mixtures. All data were successfully fitted to a model based on solvent exchange equilibria, which allowed the separation of the different contributions of the solvent species in the solvation shell of the dye. This model was then successfully applied to explain the kinetic behavior of the methylation of sodium 4‐nitrophenoxide in acetone–water mixtures. This result suggests that this solvatochromic strategy can be successful in the analysis of many other solvent‐dependent kinetic and thermodynamic processes occurring in mixed solvents. Copyright © 2002 John Wiley & Sons, Ltd.
Experimental and computational studies of α‐lactones: Structure and bonding in the three‐membered ring
Authors: Buchanan J. Grant , Charlton Michael H. , Mahon Mary F. , Robinson James J. , Ruggiero Giuseppe D. , Williams Ian H. 
Published: October 2002

AbstractCrystallographic analysis of the bromo‐β‐lactones obtained by addition of bromine to aqueous solutions of disodium 2,3‐dimethylmaleate and 2,3‐dimethylfumarate reveals stereochemistries (4 from 1, and 3 from 2) opposite to those originally assigned (3 from 1, and 4 from 2). Specifically, the maleate leads to a bromo‐β‐lactone with the methyl groups in a trans relationship, whereas the fumarate leads to the corresponding cis isomer. To account for this observation, we suggest that the first‐formed intermediate in each case is an α‐lactone. B3LYP/6–31 + G(d) calculations in PCM water indicate that the cyclic chloronium and bromonium adducts of acrylate anion are not intermediates but transition structures for the degenerate rearrangement of halomethyl‐α‐lactones. Bader analysis of MP2/6–31 + G(d,p) electron density distributions indicates that oxiranone possesses considerable ionic character in the endocyclic Cα—On bond. In PCM water there is neither a ring critical point nor a bond critical point for Cα—On, although geometrically the molecule still possesses an acute‐angled three‐membered ring with a CαCOn angle of only 69°. Combined quantum/classical calculations for B3LYP/6–31 + G(d) oxiranone surrounded by about 600 explicit TIP3P water molecules indicate that the cyclic structure is an energy minimum in aqueous solution, and Bader analysis gives a result similar to that from the continuum model. Copyright © 2002 John Wiley & Sons, Ltd.
A stable β‐silyl carbocation with allyl conjugation
Authors: Lambert Joseph B. , Liu Chunqing , Kouliev Timur 
Published: October 2002

AbstractThe carbocation Et3SiCH2C+Ph(CHCHPh) has been found to be stable at room temperature with tetrakis(pentafluorophenyl)borate as the anion and benzene as the solvent. The cation constitutes the first stable β‐silyl carbocation in which positive charge is delocalized both allylically and benzylically. Copyright © 2002 John Wiley & Sons, Ltd.