bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion chromatographic method development for monitoring of seawater quality used in over‐the‐counter pharmaceutical industry
Authors: Bolanča Tomislav , Cerjan‐Stefanović Štefica , Regelja Melita , Štanfel Danijela 
Published: August 2005

AbstractA methodology is developed for the analysis of inorganic anions (fluoride, chloride, bromide, sulphate) in seawater used for over‐the‐counter (OTC) nasal spray production. The eluent flow rate and concentration of eluent competing ions are optimised by using an artificial neural network resolution model in combination with normalised resolution product criterion function. The developed artificial neural network resolution model shows good predictive ability R 2 ⪈ 0.9973. The determined ion chromatographic parameters enable baseline separation of all components of interest. By performing a validation procedure and a number of statistical tests, it is shown that the developed ion chromatographic method has superior performance characteristics: linearity R 2 ⪈ 0.9993, recovery = 99.77–100.65%, repeatability RSD ⪇ 1.85%. This result proves that the proposed method can be used for routine quality assurance analysis in OTC pharmaceutical industry.
Application of artificial neural networks for gradient elution retention modelling in ion chromatography
Authors: Bolanča Tomislav , Cerjan‐Stefanović Štefica , Regelja Melita , Regelja Hrvoje , Lončarić Sven 
Published: August 2005

AbstractGradient elution in ion chromatography (IC) offers several advantages: total analysis time can be significantly reduced, overall resolution of a mixture can be increased, peak shape can be improved (less tailing) and effective sensitivity can be increased (because there is little variation in peak shape). More importantly, it provides the maximum resolution per time unit. The aim of this work was the development of a suitable artificial neural network (ANN) gradient elution retention model that can be used in a variety of applications for method development and retention modelling of inorganic anions in IC. Multilayer perceptron ANNs were used to model the retention behaviour of fluoride, chloride, nitrite, sulphate, bromide, nitrate and phosphate in relation to the starting time of gradient elution and the slope of the linear gradient elution curve. The advantage of the developed model is the application of an optimized two‐phase training algorithm that enables the researcher to make use of the advantages of first‐ and second‐order training algorithms in one training procedure. This results in better predictive ability, with less time required for the calculations. The number of hidden layer neurons and experimental data points used for the training set were optimized in terms of obtaining a precise and accurate retention model with respect to minimization of unnecessary experimentation and time needed for the calculation procedures. This study shows that developed ANNs are the method of first choice for retention modelling of inorganic anions in IC.
An efficient slurry packing procedure for the preparation of columns applicable in capillary electrochromatography and capillary electrochromatography‐electrospray‐mass spectrometry
Authors: Lynen Frederic , Buica Astrid , de Villiers Andre , Crouch Andrew , Sandra Pat 
Published: August 2005

AbstractA procedure is described for the slurry packing of 50‐μm ID fused silica capillaries with 3‐μm octadecyl silica (ODS) particles for capillary electrochromatography (CEC) and its hyphenation with electrospray ionisation mass spectrometry (ESI/MS). A homogeneous packed bed is obtained by using a slow packing process in an upward direction with a balanced density slurry solvent and MeOH as packing solvent. Special attention was paid to the in‐ and outlet frit preparation in order to avoid gas bubble formation which renders CEC‐ESI/MS problematic. Frits were made out of the packed bed itself, sintered in water, by using a perforated heating ribbon; they were not longer than 1 mm. In CEC‐UV, column efficiencies up to 300,000 plates per meter were obtained. Absence of gas bubbles was ascertained by the straightforward coupling to ESI/MS. A make‐up flow of 3 μL/min H2O/MeOH containing 0.1% HCOOH was used in the sheath flow interface. Steroids and carbamates were analysed with a 0.1% triethylamine‐acetic acid buffer (pH 8.9) containing varying amounts of acetonitrile. In CE‐ESI/MS, efficiencies dropped by ca. 20% but spectral data were excellent.
HPLC‐PDA characterisation ofDaphne gnidiumL. (Thymemeacea) dyeing extracts using two different C‐18 stationary phases
Authors: Nowik Witold 
Published: August 2005

AbstractRaw aqueous extracts and acid‐hydrolysed extracts from leaves and stems ofDaphne gnidiumL. were investigated by HPLC‐PDA under two different separation conditions. This approach provides improved characterisation of natural compounds, especially those with similar structures, thanks to better resolution of critical pairs which can be difficult to separate by modification of gradient parameters only. In the leaf extracts, the presence of luteolin‐3′,7‐di‐O‐glucoside was found according to the results obtained for a standard sample. This compound is reported for the first time in this species. The presence of some other, previously reported flavonoids is confirmed. The stem extract is rich in coumarins and seems not to contain any significant amounts of flavonoids. Further investigation of hydrolysed extracts is a useful additional step in the indirect identification of flavonoid and coumarin glycosides.
Injector‐internal thermal desorption from edible oils. Part 1: Visual experiments on sample deposition on the liner wall
Authors: Biedermann Maurus , Fiselier Katell , Grob Koni 
Published: August 2005

AbstractInjector‐internal thermal desorption from edible oils or fats enables the analysis of a wide range of compounds in oils or extracts of fatty food without prior removal of the sample matrix. The oil or fat is deposited onto the wall of the injector liner. The solutes of interest are evaporated, leaving behind the sample matrix. The injector is kept at a temperature volatilizing the solutes of interest, but minimizing evaporation of the bulk material of the oil. This technique was optimized regarding sample deposition on the liner wall (Part 1) and desorption of high boiling compounds, such as migrants from food packaging materials into simulant D (olive oil) or fatty food (Part 2). The sample liquid should be transferred to the liner wall and spread to a thin film in order to facilitate the release of high boiling components. Visual experiments with perylene‐containing solutions showed that the oil must be diluted to reduce the viscosity (separation from the needle tip). The oil concentration should not exceed 20% in order to rule out that squirting sample liquid drops to the bottom of the vaporizing chamber. Further dilution to about 10% oil improves spreading of the liquid to a thin film. A rather high boiling solvent should be used, such as n‐butyl acetate, to prevent thermospray at the needle exit and violent evaporation from the liner wall with sputtering liquid. Using a 5‐mm ID liner, 5–10‐μL injections of 10–20% oil solutions were at the upper limit.
High‐performance liquid chromatography of some basic drugs on a n‐octadecylphosphonic acid modified magnesia‐zirconia stationary phase
Authors: He Hai‐Bo , Feng Yu‐Qi , Da Shi‐Lu , Hu Zhi‐Xiong , Qu Li 
Published: August 2005

AbstractThe high‐performance liquid chromatographic behavior of some basic drugs was studied on a n‐octadecylphosphonic acid modified magnesia‐zirconia (C18PZM) stationary phase. The effect of mobile phase variables such as methanol content, ionic strength, and pH on their chromatographic behavior was investigated. The retention mechanism of basic drugs on the stationary phase was elucidated. The results indicate that both hydrophobic and cation‐exchange interactions contribute to solute retention under most chromatographic conditions. The inherent Brönsted‐acid sites and also the adsorbed Lewis base anionic buffer constituents on accessible ZM surface Lewis acid sites play a role in the retention of ionized solutes by cation‐exchange interaction. However, especially at high mobile phase pH, the retention of basic drugs depends mainly on hydrophobic interactions between solutes and support. Separations of the basic drugs on the C18PZM phase by a predominantly reversed‐phase retention mode were very promising. The mixed‐mode retention feature on this phase, as a result of the adsorbed Lewis base anionic buffer constituents acting as sites for cation‐exchange, could also be very useful, e.g. for enhancing the chromatographic selectivity of such analytes. The C18PZM seems to be an excellent alternative to silica‐based reversed‐phase stationary phase for the separation of strongly basic solutes.
Chromatographic determination of itopride hydrochloride in the presence of its degradation products
Authors: Kaul Neeraj , Agrawal Himani , Maske Pravin , Ramchandra Rao Janhavi , Mahadik Kakasaheb Ramoo , Kadam Shivajirao S. 
Published: August 2005

AbstractTwo sensitive and reproducible methods are described for the quantitative determination of itopride hydrochloride (IH) in the presence of its degradation products. The first method is based on HPLC separation on a reversed phase Kromasil column [C18 (5‐μm, 25 cm×4.6 mm, ID)] at ambient temperature using a mobile phase consisting of methanol and water (70:30, v/v) adjusted to pH 4.0 with orthophosphoric acid with UV detection at 258 nm. The flow rate was 1.0 mL per min with an average operating pressure of 180 kg/cm2. The second method is based on HPTLC separation on silica gel 60 F254 using toluene:methanol:chloroform:10% ammonia (5.0:3.0:6.0:0.1, v/v/v/v) as mobile phase at 270 nm. The analysis of variance (ANOVA) and Student's t‐test were applied to correlate the results of IH determination in dosage form by means of HPLC and HPTLC methods. The drug was subjected to acid and alkali hydrolysis, oxidation, dry heat, wet heat treatment, UV, and photodegradation. The proposed HPLC method was utilized to investigate the kinetics of the acidic, alkaline, and oxidative degradation processes at different temperatures and the apparent pseudo‐first‐order rate constant, half‐life, and activation energy were calculated. In addition the pH‐rate profile of degradation of IH in constant ionic strength buffer solutions in the pH range 2–11 was studied.
Principal opium alkaloids as possible biochemical markers for the source identification of Indian opium
Authors: Mohana Mudiam , Reddy Krishna , Jayshanker Gurumurthy , Suresh Velayudhan , Sarin Rajendra Kumar , Sashidhar R. B. 
Published: August 2005

AbstractA total of 124 opium samples originating from different licit opium growing divisions of India were analyzed for their principal alkaloid (thebaine, codeine, morphine, papaverine, and narcotine) content by capillary zone electrophoresis (CZE) without derivatization or purification. Absence of papaverine in Bareilly, Tilhar, and most of the samples originating from Kota is a significant observation in relation to the source of Indian opium. Multiple discriminant analysis was applied to the quantitative principal alkaloid data to determine an optimal classifier in order to evaluate the source of Indian opium. The predictive value based on the discriminant analysis was found to be 85% in relation to the source of opium and the study also revealed that all the principal alkaloids have to be analyzed for source identification of Indian opium. Chemometrics performed with principal alkaloids analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz., group I, II, and III. The methodology developed may find wide forensic application in identifying the source of licit or illicit opium originating from India, and to differentiate it from opium originating from other opium producing countries.
A dynamical approach to large eddy simulation of turbulent flows: existence of weak solutions
Authors: Świerczewska Agnieszka 
Published: August 2005

AbstractWe consider a system of equations coming from turbulence models using a large eddy simulation (LES) technique. The idea of this approach bases on decomposing the velocity into a part containing large flow structures and a part consisting of small scales. The equations for large‐scale quantities are derived from the Navier–Stokes equations with an additional constitutive relation for the contribution of small eddies. The mathematical difficulties in this paper focus on the non‐linear and non‐local turbulent term. Copyright © 2005 John Wiley & Sons, Ltd.
Complete assignments of 1H and 13C NMR spectral data for benzylidenebenzyl butyrolactone lignans
Authors: da Silva Rosangela , Pedersoli Susimaire , Lacerda Valdemar , Donate Paulo Marcos , de Albuquerque Sérgio , Bastos Jairo Kenupp , de Matos Araújo Ana Lúcia Santos , e Silva Márcio Luis Andrade 
Published: August 2005

AbstractThe structures of three benzylidenebenzyl butyrolactone lignans (gossypifan, carthamogenin, and savinin) have been established on basis of 1H NMR and 13C NMR spectroscopic data. The 1H NMR and 13C NMR spectra of these lignans have been fully assigned by the use of techniques such as gCOSY, non‐edited gHSQC, and gHMBC. Complete assignment and most homonuclear hydrogen coupling constant measurements were performed, also providing enough data for the determination of the relative stereochemistry. Copyright © 2005 John Wiley & Sons, Ltd.
The axisymmetric consolidation of a semi‐infinite transversely isotropic saturated soil
Authors: Chen S. L. , Chen L. Z. , Zhang L. M. 
Published: August 2005

AbstractThis paper presents an exact analytical solution to fully coupled axisymmetric consolidation of a semi‐infinite, transversely isotropic saturated soil subjected to a uniform circular loading at the ground surface. The analysis is under the framework of Biot's general theory of consolidation. First, the governing equations of consolidation are transformed into a set of equivalent partial differential equations with the introduction of two auxiliary variables. These partial differential equations are then solved using Hankel–Laplace integral transforms. Once solutions in the transformed domain have been obtained, the actual solutions in the physical domain for displacements and stress components of the solid matrix, pore‐water pressure and fluid discharge can be finally obtained by direct numerical inversion. The accuracy of the numerical solutions developed is confirmed by comparison with an existing exact solution for an isotropic and saturated soil that is a special case of the more general problem addressed. Numerical analyses are also presented to investigate the influence of the degree of material anisotropy on the consolidation settlement. Copyright © 2005 John Wiley & Sons, Ltd.
A simplified analysis method for piled raft foundations subjected to ground movements induced by tunnelling
Authors: Kitiyodom Pastsakorn , Matsumoto Tatsunori , Kawaguchi Kanji 
Published: August 2005

AbstractA simplified method of numerical analysis has been developed to estimate the deformation and load distribution of piled raft foundations subjected to ground movements induced by tunnelling and incorporated into a computer program ‘PRAB’. In this method, a hybrid model is employed in which the flexible raft is modelled as thin plates, the piles as elastic beams, and the soil is treated as interactive springs. The interactions between structural members, pile–soil–pile, pile–soil–raft and raft–soil–raft interactions, are modelled based on Mindlin's solutions for both vertical and lateral forces. The validity of the proposed method is verified through comparisons with some published solutions for single piles and pile groups subjected to ground movements induced by tunnelling. Thereafter, the solutions from this approach for the analysis of a pile group and a piled raft subjected to ground movements induced by tunnelling are compared with those from three‐dimensional finite difference program. Good agreements between these solutions are demonstrated. The method is then used for a parametric study of single piles, pile groups and piled rafts subjected to ground movements induced by tunnelling. Copyright © 2005 John Wiley & Sons, Ltd.
Clinical aspects and treatment of pain in children and adolescents with cancer
Authors: Monteiro Caran Eliana Maria , Dias Carla Gonçalves , Seber Adriana , Petrilli Antonio Sérgio 
Published: August 2005

AbstractBackgroundThe aim of this study was to characterize the clinical aspects and the treatment of mild to severe pain in Brazilian children and adolescents with cancer. We evaluated the importance of classifying patients according to the phase of cancer treatment (diagnosis, treatment, recurrence, and end‐of‐life palliative care) and the opioid‐related side effects.MethodsAn institutional prospective study of 184 episodes of pain in children and adolescents with cancer was conducted. Pain was classified according to its cause, physiopathology and intensity. Treatment was based on the WHO guidelines for cancer pain relief.ResultsPain scales were completed by 77% of the patients. Numerical scales were used by 49% of them. Morphine was given in 111 episodes for 2,758 patient days. Morphine doses had to be escalated when it was given to patients during end‐of‐life palliative care. Opioids were well tolerated with no severe side effects. Psychological dependence on morphine was found in 2% (2/111) of the cases. Pain control was satisfactory in 97% of the episodes.ConclusionsThe WHO guidelines for cancer pain relief were effective in controlling pain in children and adolescents with cancer. Despite their low socioeconomic level, patients were able to quantify their pain using rating scales. © 2003 Wiley‐Liss, Inc.
Familial adenomatous polyposis in two brothers with hepatoblastoma: Implications for diagnosis and screening
Authors: Sanders Robert P. , Furman Wayne L. 
Published: August 2005

AbstractTwo brothers with hepatoblastoma were noted to have a family history of early onset colon cancer. Genetic testing of the younger brother revealed a deletion in exon 15 of the adenomatous polyposis coli (APC) gene (2710‐2711delAG), consistent with a diagnosis of familial adenomatous polyposis (FAP). We review the clinical and molecular aspects of the relationship between hepatoblastoma and FAP, and the implications for diagnostic testing and cancer screening in affected patients. Pediatric Blood Cancer 2006;47:851–854. © 2005 Wiley‐Liss, Inc.
Painful procedures in children with cancer: Comparison of moderate sedation and general anesthesia for lumbar puncture and bone marrow aspiration
Authors: Iannalfi Alberto , Bernini Gabriella , Caprilli Simona , Lippi Alma , Tucci Fabio , Messeri Andrea 
Published: August 2005

AbstractBackgroundThe study was conducted to compare moderate sedation (MS) with general anesthesia (GA) in the management of frequently performed lumbar puncture or bone marrow aspiration (BMA) during the treatment of childhood cancer.ProcedureThe MS (14 patients for 30 procedures) was managed by non‐anesthesiologists (combined nitrous oxide‐midazolam ± non‐pharmacological techniques). The GA was managed by anesthesiologists (17 patients for 30 procedures). A neutral observer recorded side effects, use of sedative antagonists, recovery time, oncologist's evaluation, procedure behaviors check list (PBCL); subjective perceptions during the procedure with a questionnaire administered to children (>6 years) and their parents; drugs costs and professional resources. P‐values <0.05 were considered significant.ResultsWe had two inadequate sedations in MS (6.6%) versus 0 in GA. We had no significant differences in side effects (7.10% MS vs. 8.6% in GA), use of antagonists (2.90% GA vs. 0 MS), PBCL, oncologist evaluation and questionnaire data or drugs costs. We observed significant differences in recovery times (MS, mean 43 ± SD min vs. GA, mean 117 ± SD min) and professional resources costs. The effects of non‐pharmacological techniques on anxiety were perceived very positively by both children and parents (on 0–4 scale, mean scores 3.57 for the children; 3.53 for the parents).ConclusionsOur study suggests that MS compared favorably to GA with respect to both safety and efficacy. When performed by non‐anesthesiologists, MS may be associated with better compliance and cost‐effectiveness as it relies on the contribution of non‐pharmacological techniques. © 2005 Wiley‐Liss, Inc.
Aneuploidy screening in coelomic samples using fluorescence in situ hybridisation (FISH)
Authors: Chatzimeletiou Katerina , Makrydimas George , Sotiriadis Alexandros , Paraskevaidis Evagelos , Nicolaides Kypros H. 
Published: August 2005

AbstractObjectivesCoelocentesis is the earliest invasive prenatal diagnostic procedure that has recently been used in ongoing pregnancies to identify single gene defects. Aneuploidy screening has not yet been performed in ongoing pregnancies following coelocentesis, but experimental studies have demonstrated the ability of determining the copy number of chromosomes 13, 18, 21, X and Y in uncultured coelomic samples, by FISH or PCR. The aim of this study was to extend previous studies and investigate the feasibility of analysing uncultured coelomic fluid samples for 11 chromosomes using fluorescence in situ hybridisation (FISH).MethodsCoelocentesis was performed in 12 singleton pregnancies at 6 to 9 weeks of gestation immediately before surgical termination of pregnancy. Fluorescence probes for chromosomes 3,7,9,13,16,17,18,21,22, X and Y were applied on uncultured coelomic‐fluid samples and placental tissue. In cases where coelomic cells were not of a sufficient amount, chromosomes X and Y were analysed in a second layer of hybridisation.ResultsSuccessful analysis by FISH was possible in all cases and the results from the coelomic fluid were concordant with those from the analysis of placental tissue and obtained within a few hours of receiving the samples. Problems associated with limited cell numbers were overcome by the application of a second layer of FISH. This sequential approach has also enabled accurate identification of maternal‐cell contamination in male samples.ConclusionAnalysis of 11 chromosomes using FISH in coelomic fluid samples is feasible and it has the potential to be applied for rapid aneuploidy screening, should coelocentesis be used clinically as an early, invasive prenatal diagnostic tool. Copyright © 2005 John Wiley & Sons, Ltd.
Drag reduction in cocurrent horizontal natural gas‐hexane pipe flow
Authors: Sylvester N. D. , Dowling R. H. , Brill J. P. 
Published: August 2005

AbstractDrag reduction in two‐phase cocurrent horizontal natural gas‐hexane pipe flow was studied experimentally. The effects of pipe diameter, gas flow rate, liquid flow rate, and additive concentration were investigated using the Dowell APE drag reducer. In the annular‐mist flow regime studied, it was found that drag reduction increased with decreasing gas rate for a given liquid rate, drag reduction decreased with increasing friction velocity and it decreased with decreasing gas‐liquid ratio for a given friction velocity. Although the drag reduction decreased rapidly as the liquid‐gas ratio approached zero, drag reductions as high as 34 percent were obtained. Attempts to predict two‐phase drag reduction were unsuccessful as it was found to depend upon friction velocity, liquid and gas rates, liquid‐gas rate ratio, pipe diameter and additive concentration.