bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidation of substituted benzaldehydes by quinolinium chlorochromate: A structure and solvent dependent kinetic study
Authors: Jeyanthi G. Fatima , Elango K. P. 
Published: February 2003

AbstractThe kinetics of oxidation of several para‐substituted benzaldehydes by quinolinium chlorochromate was studied under pseudo‐first‐order conditions in different (hydrogen bond donor and hydrogen bond acceptor) neat organic solvents. The operation of nonspecific and specific solvent–solvent–solute interactions was explored by correlating the rate data with solvent parameters through correlation analysis. Both electron‐releasing and electron‐withdrawing substituents enhanced the rate and the Hammett plot showed a break in the reactivity order indicating applicability of dual mechanism. An explanation in conformity with structure and solvent effects on reactivity has been proposed. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 154–158, 2003
The demand for game day attendance in college football: an analysis of the 1997 Division 1‐A season
Authors: Price Donald I. , Sen Kabir C. 
Published: January 2003

AbstractThis paper develops a predictive model which includes game, team and university specific factors that are likely to influence game day demand for Division 1‐A college football. Attendance during the 1997 regular season is used as the dependent variable. Tobit estimates of two separate equations reveal that the quality of both teams, traditional rivalry and membership of specific conferences have a significant influence on demand. In addition, colleges with lower enrollments and a higher percentage of off‐campus students attract smaller crowds. The presence of a nearby professional football team also detracts from a college team's drawing power. Copyright © 2003 John Wiley & Sons, Ltd.
Explaining the profitability of foreign banks in Shanghai
Authors: Leung M.K. , Young T. , Rigby D. 
Published: January 2003

AbstractThis paper uses survival analysis to examine the factors determining the time taken for branches of foreign banks in Shanghai, China to make a positive rate of return after entering that market. Particular attributes of banks including the parent bank's size, early entry and the number of branches the bank has in China are found to reduce time to profitability. Market conditions in Shanghai, captured by levels of foreign direct investment and Eurodollar interest rates, are also found to have significant effects. A number of managerial implications are drawn from the analysis in light of the greater access to the Chinese banking markets following China's accession to the WTO. To ensure long‐term profitability in Shanghai, the foreign bank needs to contain costs and risks in the new markets, formulate an effective market penetration strategy, identify appropriate customer target groups, attract businesses from firms of different countries, seek early entry and undertake more fee‐income generating businesses. Copyright © 2003 John Wiley & Sons, Ltd.
A prospective study of minimally invasive techniques in pediatric surgical oncology: preliminary report
Authors: Warmann Steven , Fuchs Jörg , Jesch Nathalie K. , Schrappe Martin , Ure Benno M. 
Published: January 2003

AbstractBackgroundThoracoscopic and laparoscopic techniques play a major role in pediatric surgery. However, minimally invasive surgery (MIS) has not yet established itself in pediatric surgical oncology. The authors present a prospective study investigating the role of MIS in children with cancer.ProcedureAll children with abdominal or thoracic tumors requiring surgery were registered between September, 2000 and February, 2002. Decisions regarding procedures and approaches—conventional or minimally invasive—were made by the interdisciplinary team. Data on diagnoses, surgical procedures, complications, and conversion rates were registered prospectively.ResultsSeventy‐four patients received 78 operations, 21 (26.9%) of the 78 operations were minimally invasive. Seven of 16 tumor biopsies (43.8%) and 9 of 57 tumor resections (15.8%) were performed using MIS, which was also exclusively used for diagnostic interventions. Conversions to standard techniques only occurred in 5 of 9 tumor resections. No major complications were encountered in the MIS group.ConclusionsMIS was practical in every fourth patient in our experience so far. It proved to be an excellent approach in diagnostic interventions and tumor biopsies, whereas efficacy is limited in tumor resections. Further factors (tumor recurrence, trocar site recurrence, tumor growth, and dissemination after CO2 insufflation) have to be evaluated. Our data encourage the continuation of the study. Med Pediatr Oncol 2003;40:155–157. © 2003 Wiley‐Liss, Inc.
Outcome after relapse in an unselected cohort of children and adolescents with Ewing sarcoma
Authors: Shankar A.G. , Ashley S. , Craft A.W. , Pinkerton C.R. 
Published: January 2003

AbstractBackgroundSurvival after relapse in patients with Ewing sarcoma is very poor and this retrospective study attempts to identify of prognostic factors predicting survival after relapse.ProcedureA total of 191 patients with localised Ewing sarcoma were registered in the ET‐2 trial of the United Kingdom Children's Cancer Study Group (UKCCSG). All patients received standardised primary treatment with chemotherapy and surgery and or radiotherapy as local modality treatment. Sixty‐four patients who relapsed are included in this report. Treatment at relapse was variable and included chemotherapy, surgery, radiotherapy and high dose therapy (HDT) or megatherapy with peripheral stem cell transplantation (PBSCT) or autologous bone marrow transplantation (ABMT) in various combinations. A subgroup of patients had only non‐specific symptomatic treatment at relapse. Both univariate and multivariate methods were used to investigate variables affecting survival after relapse.ResultsThe overall actuarial median survival from relapse for all patients was 14 months (95% CI 11–16 months). Univariate analysis showed that males had a longer survival (median, 16 months vs. 11 months); patients who relapsed while on treatment did worse (median, 3 months vs. 16 months) and patients who had a longer disease‐free interval (DFI) prior to relapse had a better outcome (DFI <1 year, median survival = 3 months; DFI 1–2 years, survival = 8 months; DFI > 2 years, median survival = 24 months,P < 0.001). Multivariate analysis confirmed that duration of first remission was the only factor associated with longer survival after relapse.ConclusionsThese data suggest that although aggressive therapy may delay disease progression after relapse for some children, the course of the disease after relapse is usually fatal. International co‐operative studies are needed to evaluate new strategies. Med Pediatr Oncol 2003;40:141–147. © 2003 Wiley‐Liss, Inc.
Hodgkin disease in ataxia‐telangiectasia patients with poor outcomes
Authors: Sandoval Claudio , Swift Michael 
Published: January 2003

AbstractBackgroundTo determine the presenting clinicopathologic features and treatment outcomes of 11 ataxia‐telangiectasia (A‐T) patients with Hodgkin disease.ProcedureWe reviewed the charts of 412 A‐T patients to ascertain cases of Hodgkin disease. The data analyzed included date of diagnosis, duration of symptoms, chest radiographic findings, stage and histology, therapy, and outcome.ResultsThe six male and five female patients had a median age at diagnosis of 12.2 years. Eight patients presented with fever, cough, and/or cervical lymphadenopathy with a median duration of symptoms of 3 months. Five patients had abnormal chest radiographic findings a median of 3 months prior to diagnosis and were treated with antibiotics for presumed pneumonia. Mediastinal and hilar adenopathy in addition to bilateral infiltrates were present. Histopathology reports were available for nine patients. Three had nodular sclerosing and two each had lymphocyte depleted, mixed cellularity, and not otherwise specified histology. Eight patients had stage IV disease, one had stage III, and in two the staging was not documented. Six patients received reduced‐dose chemotherapy, two received radiation therapy, two did not receive therapy, and in one the treatment was not documented. In no patient did the Hodgkin disease remit and all died with a median survival of 3 months. Eight died of pneumonia and three of multiple system organ failure.ConclusionsA‐T patients with Hodgkin disease have markedly reduced survival compared to Hodgkin disease in the general population. Their poor outcomes may be due to advanced Hodgkin disease, failure to recognize coincident chronic lung disease, and the use of non‐standard treatment regimens. Med Pediatr Oncol 2003;40:162–166. © 2003 Wiley‐Liss, Inc.
DNQ–novolac photoresists revisited: 1H and 13C NMR evidence for a novel photoreaction mechanism
Authors: Roy Debmalya , Basu P. K. , Raghunathan P. , Eswaran S. V. 
Published: January 2003

AbstractPhotoactive compounds, such as diazonaphthoquinone (DNQ) esters, blended with novolac resins, solvents and certain additives, serve as photoresists. These are used for printing of electronic circuits at the micron or sub‐micron level. Patterns are generated based on changes in the physical and chemical properties of the exposed and unexposed photoresist surfaces (printed circuit boards). The huge polarity change between the exposed and unexposed photoresists is exploited in the technique of microlithography. It is believed that the large polarity difference is due to acid formation in the exposed photoresist by a photochemical reaction of DNQ on exposure to light. However, it has also been suggested that in the unexposed part of a photoresist, the novolac resin undergoes an azo coupling reaction with DNQ, leading to an increase in the molecular weight of the resin, rendering it more insoluble in base. The protons in the para positions of the m‐cresol units incorporated in the novolac resin are believed to take part in this azo coupling reaction with DNQ. In this paper, we propose a novel mechanism of action of positive photoresists in the unexposed part of photoresists for dissolution inhibition using molecular modelling, 1H NMR, 13C NMR and DEPT‐135 NMR spectroscopic techniques. Our results enable us to propose that the diazo group of DNQ attacks the methylene bridges rather than the aromatic moiety of the resin. This mechanism explains the pattern formation observed using even p‐cresol‐based resins, where no free para positions are present in the aromatic ring. Copyright © 2003 John Wiley & Sons, Ltd.
Non‐empirical calculations of NMR indirect carbon–carbon coupling constants: 2. Strained polycarbocycles
Authors: Krivdin Leonid B. 
Published: January 2003

AbstractHigh‐level non‐empirical calculations of carbon–carbon spin–spin coupling constants in a series of strained polycarbocycles have been carried out, in excellent agreement with available experimental data. The utmost importance of electronic correlation effects in this case has been demonstrated and it has been shown that the Second‐Order Polarization Propagator Approach (SOPPA) is an adequate method to account for those effects. It has been demonstrated that the most reliable basis sets to calculate J(C,C) at the SOPPA level are the correlation‐consistent basis sets of Dunning and co‐workers augmented with inner core s‐functions or decontracted in their s‐parts. The nature of the unusual bridgehead–bridgehead bonds in bicyclobutane and propellane in terms of s‐characters of bonding hybrids and also the hybridization effects in spiropentane are discussed based on the arguments derived from the current calculations of J(C,C) in the title compounds. The values of the unknown J(C,C) in propellane and spiropentane are predicted with high reliability. Copyright © 2003 John Wiley & Sons, Ltd.
19F, 13C NMR analysis of an oxygen carrier, perfluorotributylamine, and perfluoropentanoic acid
Authors: Ribeiro Anthony A. , Umayahara Keiko 
Published: January 2003

AbstractNMR relaxation measurement of perfluorocarbons (PFCs), such as perfluorotributylamine (FTBA), is a convenient method for the determination of oxygen concentrations in tissues and tumors. Previous relaxation studies of FTBA used different 19F NMR assignments causing some confusion. Fluorine‐detected 19F, 13C HMQC and HMBC and selectively 19F‐decoupled 13C NMR provided unequivocal 19F and 13C assignments for FTBA and perfluoropentanoic acid (FPA). Based on those assignments, 13C spin–lattice relaxation time constants (T1) and effective correlation times for FTBA and FPA are reported and discussed. Copyright © 2003 John Wiley & Sons, Ltd.
Configurational assignment in alkyl‐branched sugars via the geminal C,H coupling constants
Authors: Schulte Jürgen , Lauterwein Jürgen , Klessinger Martin , Thiem Joachim 
Published: January 2003

AbstractThe measurement of the magnitude and sign of 2J(C,H) couplings offers a reliable way to determine the absolute configuration at a carbon center in a fixed cyclic system. A decrease of the dihedral angle ϕ in the O—CA—CB—H fragment always leads to a change of the 2J(CA,HB) coupling to more negative values, independent of the type and position of substituents at the two carbon centers. The orientations of the two substituents at C‐3 of the epimeric pair 1 and 2 were determined unambiguously through the measurement of the geminal coupling constants between C‐3 and the hydrogen atoms at C‐2 and C‐4. In particular, 2J(C‐3,H‐2ax) with −1.5 Hz, ϕ = 174° in 1 and −6.6 Hz, ϕ = 47° in 2, and 2J(C‐3,H‐4) with +1.5 Hz, ϕ = 175° in 1 and −4.7 Hz, ϕ = 49° in 2 showed the greatest differences between the two epimers. Both couplings therefore allow the determination of the absolute configuration at C‐3. It should be noted, however, that the size of the coupling constants can be different for dihedral angles of nearly identical size, when there are different numbers of electronegative substituents on the two coupling pathways, i.e. no O‐substituent at C‐2, but one axial O‐substituent at C‐4. It becomes clear that it is not sufficient to measure the magnitude of 2J coupling constants only, but that the sign of the geminal coupling is needed to identify the absolute configuration at a chiral center. The coupling of C‐3 with H‐2eq is not useful for the determination of the configuration at C‐3, as the similarity of the dihedral angles ϕ (O—C‐3—C‐2—H‐2eq) (57° in 1 and 70° in 2) leads to identical coupling constants (−6.1 Hz) for both epimers. Copyright © 2003 John Wiley & Sons, Ltd.
Deuterium isotope effects on 15N chemical shifts of double Schiff bases in the solid state and solution
Authors: Dziembowska T. , Ambroziak K. , Rozwadowski Z. , Schilf W. , Kamieński B. 
Published: January 2003

AbstractThe proton transfer equilibrium in a series of double Schiff base derivatives of trans‐1,2‐diaminocyclohexane in solution and the solid state was studied by means of 15N NMR spectroscopy and analysis of the deuterium isotope effect on the chemical shifts Δ15N(D). The presence of a proton transfer equilibrium in the N‐2‐hydroxynaphthylidene moieties of the Schiff bases studied in the solid state at room temperature was evidenced. The results confirmed the interrelation of the two hydrogen bonds in double Schiff base derivatives of trans‐1,2‐diaminocyclohexane. Copyright © 2003 John Wiley & Sons, Ltd.
Structure elucidation and 13C NMR spectral assignments of 3α‐hydroxyolean‐12‐en‐30‐oic acid, a new triterpene from Bocconia arborea
Authors: Chávez María Isabel , Julián Aníbal , Delgado Guillermo 
Published: January 2003

AbstractThe structure and 13C NMR assignments of 3α‐hydroxyolean‐12‐en‐30‐oic acid (20‐epi‐katonic acid), a novel pentacyclic triterpene isolated from the aerial parts of Bocconia arborea (Papaveraceae), are reported. Copyright © 2003 John Wiley & Sons, Ltd.
A new cytotoxic limonoid from Odontadenia macrantha from the Suriname rainforest
Authors: Prakash Chaturvedula V. S. , Schilling Jennifer K. , Wisse Jan H. , Miller James S. , Evans Randy , Kingston David G. I. 
Published: January 2003

AbstractBioassay‐guided fractionation of the methanol extract of Odontadenia macrantha afforded a new limonoid, odontadenin A (1) and two known triterpenoids, lupeol (2) and α‐amyrin (3). The structure of 1 was established on the basis of 1D and 2D NMR and high‐resolution fast atom bombardment mass spectrometric data. The new compound was found to possess moderate cytotoxicity against A2780, the ovarian cancer cell line. Copyright © 2003 John Wiley & Sons, Ltd.
An inverse radiation problem of simultaneous estimation of heat transfer coefficient and absorption coefficient in participating media
Authors: Park H. M. , Lee W. J. 
Published: January 2003

AbstractAn inverse radiation problem is investigated where the spatially varying heat transfer coefficient h(z) and the absorption coefficient κ in the radiant cooler are estimated simultaneously from temperature measurements. The inverse radiation problem is solved through the minimization of a performance function, which is expressed by the sum of square residuals between calculated and observed temperature, using the conjugate gradient method. The gradient of the performance function is evaluated by means of the improved adjoint variable method that can take care of both the function estimation and the parameter estimation efficiently. The present method is found to estimate h(z) and κ with reasonable accuracy even with noisy temperature measurements. Copyright © 2002 John Wiley & Sons, Ltd.
Application of a new differential quadrature methodology for free vibration analysis of plates
Authors: Karami G. , Malekzadeh P. 
Published: January 2003

AbstractA new methodology is introduced in the differential quadrature (DQ) analysis of plate problems. The proposed approach is distinct from other DQ methods by employing the multiple boundary conditions in a different manner. For structural and plate problems, the methodology employs the displacement within the domain as the only degree of freedom, whereas along the boundaries the displacements as well as the second derivatives of the displacements with respect to the co‐ordinate variable normal to the boundary in the computational domain are considered as the degrees of freedom for the problem. Employing such a procedure would facilitate the boundary conditions to be implemented exactly and conveniently. In order to demonstrate the capability of the new methodology, all cases of free vibration analysis of rectangular isotropic plates, in which the conventional DQ methods have had some sort of difficulty to arrive at a converged or accurate solution, are carried out. Excellent convergence behaviour and accuracy in comparison with exact results and/or results obtained by other approximate methods were obtained. The analogous DQ formulation for a general rectangular plate is derived and for each individual boundary condition the general format for imposing the given conditions is devised. It must be emphasized that the computational efforts of this new methodology are not more than for the conventional differential quadrature methods. Copyright © 2002 John Wiley & Sons, Ltd.
On numerical analyses in the presence of unstable saturated porous materials
Authors: Benallal A. , Comi C. 
Published: January 2003

AbstractThe numerical analysis of the dynamic evolution problem concerning an elastic–plastic saturated porous media in the presence of softening (or non‐associativity) is considered in the framework of the Biot formulation extended to take into account plastic phenomena. The finite step boundary value problem, obtained by discretization in time of the continuous initial boundary value problem, is studied and the issue of its ill‐posedness is particularly addressed. The conditions for the loss of ellipticity are established for the linearized problem solved at each iteration when using the Newton–Raphson scheme. In particular, the roles of the algorithmic properties on this loss of ellipticity are derived in detail. The integration scheme of the balance of mass equation plays a major role and it is shown that the fluid flow (Darcy's law) does indeed introduce a length scale but in addition to being dependent on the integration time step, it is found to be insufficient for regularization. To illustrate and corroborate the obtained results, a one‐dimensional example (exhibiting all the features of the three‐dimensional situation) is considered and the corresponding linearized finite step problem is solved in closed form. Copyright © 2002 John Wiley & Sons, Ltd.
Expression of haem oxygenase in cirrhotic rat liver
Authors: Wei Chang‐Li , Lee Kang‐Hoe , Khoo Hoon‐Eng , Hon Wei‐Min 
Published: February 2003

AbstractThe haem oxygenase (HO)/carbon monoxide (CO) system has been implicated as a modulator of hepatobiliary function. This study investigated HO expression in the process of cirrhosis development, as well as its relationship to nitric oxide synthase (NOS). Liver cirrhosis was induced in rats by chronic bile duct ligation (BDL). HO mRNA expression was evaluated by competitive RT‐PCR, while protein expression was determined by immunoblotting and immunohistochemistry. In liver tissue where cirrhosis had fully developed, the expression levels of HO‐1 were greatly enhanced at both mRNA and protein level compared with sham livers. Immunohistochemistry showed that HO‐1 was induced in hepatocytes and enhanced in some of the Kupffer‐like cells in BDL livers. In contrast, there was no difference between the sham and the BDL livers for the expression levels of HO‐2. Interestingly, administration of the NOS inhibitor aminoguanidine (AG) or NG‐nitro‐L‐arginine methyl ester inhibited HO‐1 expression. To study further the role of HO‐1 in the development of liver cirrhosis, hepatocytes were isolated from the rats at different time points after BDL operation. HO‐1 was expressed in hepatocytes at high levels during the early onset of cirrhosis but dropped slightly at a later stage of cirrhosis. Zinc protoporphyrin IX (ZnPP), an HO inhibitor, blocked HO‐1 expression in hepatocytes from BDL cirrhotic rats, but enhanced the activity of inducible NOS (iNOS) in BDL hepatocytes. In conclusion, HO‐1 was induced in the hepatocytes of rats undergoing cirrhosis, suggesting that HO‐1 plays a role in the development of liver cirrhosis. Induction of HO‐1 may be mediated partially by iNOS. However, once it is induced, HO‐1 may be important in modulating iNOS activity, thus playing a protective role in liver cirrhosis. Copyright © 2003 John Wiley & Sons, Ltd.