Reported Values (reported + value)

Distribution by Scientific Domains


Selected Abstracts


The role of women's self-injury support-groups: a grounded theory

JOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 1 2007
Jennifer Corcoran
Abstract Research evidence suggests that services are struggling to adequately address the increasing incidence of self-injury and the needs of women who self-injure, while national self-injury support-groups across the UK appear to be growing in number. Despite their reported value, evidence regarding the role of self-injury support-groups in women's management of their self-injury is lacking although government policy and official guidelines are advocating the incorporation of support-groups into self-injury services. Seven semi-structured interviews were conducted and analysed using Grounded Theory to investigate the role of three UK self-injury support-groups in women's management of self-injury and associated difficulties. Empowerment-as-process emerged as the core theme of self-injury support-groups, mediated through experiences of belonging, sharing, autonomy, positive feeling and change. Findings are discussed in relation to relevant theory and research, followed by critical evaluation and implications of the study. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Development of an electrochemical cell for efficient hydrogen production through the IS process

AICHE JOURNAL, Issue 8 2004
Mikihiro Nomura
Abstract The Bunsen reaction (SO2 + I2 + 2H2O = H2SO4 + 2HI) was examined by an electrochemical cell featuring a cation-exchange membrane as the separator, using sulfuric acid dissolving sulfur dioxide as the anolyte and hydriodic acid dissolving iodine as the catholyte. In galvanostatic electrolysis, the molality of H2SO4 in the anolyte and that of HI in the catholyte were increased up to 17.8 and 14.9 mol kgH2O,1, respectively. These concentrations were far higher than those that were obtained by the Bunsen reaction carried out in the presence of a large amount of iodine (such as I2/HI = 4). I2 concentration after the concentration procedure was at I2/HI = 0.95, which is lower than the reported value. I2 is one of the recycling agents in the IS process. HI and H2SO4 were successfully concentrated under low I2 concentration. The concentration of HI agreed with the calculated value, based on the amount of electricity consumed, indicating high current efficiency. Heat/mass balance using this type of electrochemical cell through the IS process is discussed for evaluation of the reactor. The thermal efficiency to produce hydrogen was calculated at 42.1%, without heat recovery for electricity, by optimizing HI and H2SO4 concentrations after application of the electrochemical cell. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1991,1998, 2004 [source]


Modelling increased soil cohesion due to roots with EUROSEM

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 13 2008
S. De Baets
Abstract As organic root exudates cause soil particles to adhere firmly to root surfaces, roots significantly increase soil strength and therefore also increase the resistance of the topsoil to erosion by concentrated flow. This paper aims at contributing to a better prediction of the root effects on soil erosion rates in the EUROSEM model, as the input values accounting for roots, presented in the user manual, do not account for differences in root density or root architecture. Recent research indicates that small changes in root density or differences in root architecture considerably influence soil erosion rates during concentrated flow. The approach for incorporating the root effects into this model is based on a comparison of measured soil detachment rates for bare and for root-permeated topsoil samples with predicted erosion rates under the same flow conditions using the erosion equation of EUROSEM. Through backwards calculation, transport capacity efficiencies and corresponding soil cohesion values can be assessed for bare and root-permeated topsoils respectively. The results are promising and present soil cohesion values that are in accordance with reported values in the literature for the same soil type (silt loam). The results show that grass roots provide a larger increase in soil cohesion as compared with tap-rooted species and that the increase in soil cohesion is not significantly different under wet and dry soil conditions, either for fibrous root systems or for tap root systems. Power and exponential relationships are established between measured root density values and the corresponding calculated soil cohesion values, reflecting the effects of roots on the resistance of the topsoil to concentrated flow incision. These relationships enable one to incorporate the root effect into the soil erosion model EUROSEM, through adapting the soil cohesion input value. A scenario analysis shows that the contribution of roots to soil cohesion is very important for preventing soil loss and reducing runoff volume. The increase in soil shear strength due to the binding effect of roots on soil particles is two orders of magnitude lower as compared with soil reinforcement achieved when roots mobilize their tensile strength during soil shearing and root breakage. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Stability, morphology and surface grain size patterns of channel bifurcation in gravel,cobble bedded anabranching rivers

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 10 2006
Leif M. Burge
Abstract This study presents the first detailed field-based analysis of the morphology of bifurcations within anabranching cobble,gravel rivers. Bifurcations divide the flow of water and sediment into downstream anabranches, thereby influencing the characteristics of the anabranches and the longevity of river islands. The history, morphology, bed grain size, and flow vectors at five bifurcations on the Renous River, New Brunswick, Canada, were studied in detail. The angles of bifurcations within five anabranching rivers in the Miramichi basin were investigated. The average bifurcation angle was 47°, within the range of values cited for braided river bifurcations. Bifurcation angle decreased when anabranches were of similar length. Shields stresses in channels upstream of bifurcations were lower than reported values for braided rivers. Stable bifurcations displayed lower Shields stresses than unstable bifurcations, contrary to experimental results from braided river bifurcations. Bifurcations in anabranching rivers are stabilized by vegetation that slows channel migration and helps to maintain a uniform upstream flow field. The morphology of stable bifurcations enhances their stability. A large bar, shaped like a shallow ramp that increases in elevation to floodplain level, forms at stable bifurcations. Floodplains at stable bifurcations accrete upstream at rates between 0·9 and 2·5 m a,1. Bars may also form within the entrance of an anabranch downstream of the bifurcation node. These bars are associated with bifurcation instability, forming after a period of stability or an avulsion. Channel abandonment occurs when a bar completely blocks the entrance to one anabranch. The stability of channels upstream of bifurcations and the location of bars at bifurcations influence bifurcation stability and the maintenance of river anabranching in the long term. Copyright © 2006 John Wiley & Sons, Ltd. [source]


A Theoretical Study of the Exchange Coupling in Hydroxo- and Alkoxo-Bridged Dinuclear Oxovanadium(IV) Compounds

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2004
Antonio Rodríguez-Fortea
Abstract A density functional study of exchange coupling in hydroxo- and alkoxo-bridged dinuclear oxovanadium(IV) compounds is presented. Coupling constants calculated for full unmodeled structures are in good agreement with experimentally reported values, confirming the ability of the computational strategy used in this work to predict the exchange coupling in dinuclear VIV compounds. The influence of the configuration of the [VO(,-OR)2VO]2+ core in compounds with two edge-sharing octahedrally coordinated oxovanadium(IV) centers, of the nature of the terminal ligands and of structural distortions on the coupling constant have been analyzed through model calculations. The results indicate that the coupling constant is less affected by these factors than for hydroxo- and alkoxo-bridged CuII compounds. The calculations support the orbital models usually employed in qualitative interpretations of magneto-structural correlations, showing good correlations between the calculated coupling constants and the overlap between the two magnetic orbitals or the square of the orbital gap. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


Characterization of the single-channel properties of NMDA receptors in laminae I and II of the dorsal horn of neonatal rat spinal cord

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2001
G. Mark Green
Abstract The single-channel properties of native NMDA receptors in laminae I and II of the dorsal horn of the neonatal rat spinal cord were studied using outside-out patch-clamp techniques. These receptors were found to have several features that distinguish them from native NMDA receptors elsewhere in the CNS. Single-channel currents activated by NMDA (100 nm) and glycine (10 µm) exhibited five distinct amplitude components with slope-conductance values of 19.9 ± 0.8, 32.9 ± 0.6, 42.2 ± 1.1, 53.0 ± 1.0 and 68.7 ± 1.5 pS. Direct transitions were observed between all conductance levels but transitions between 69-pS openings and 20-, 33- and 42-pS openings were rare. There was no significant difference in the frequency of direct transitions from 42- to 20-pS compared to 20- to 42-pS transitions. The Kb (0 mV) for Mg2+ was 89 µm. The Mg2+ unblocking rate constant was similar to other reported values. However, the Mg2+ blocking rate constant was larger than other reported values, suggesting an unusually high sensitivity to Mg2+. The NR2B subunit-selective antagonist, ifenprodil, had no significant effect on overall channel activity but significantly decreased the mean open time of 53-pS openings. These results suggest neonatal laminae I and II NMDA receptors are not simply composed of NR1 and NR2B subunits or NR1 and NR2D subunits. It is possible that these properties are due to an as yet uninvestigated combination of two NR2 subunits with the NR1 subunit or a combination of NR3A, NR2 and NR1 subunits. [source]


Enantioselective Synthesis of the Originally Proposed Usneoidone Structure: Evidence for a Structural Revision

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 9 2004
Michèle Danet
Abstract The enantioselective synthesis of the initially proposed structure of usneoidone has been completed according to a convergent strategy in which the key steps were an enantioselective Michael addition involving chiral imines to set up the C12 quaternary center, and the final assembly of the chiral pyran moiety with the aromatic subunit through a cyanohydrin anion alkylation step. The obtained product displays spectroscopic data that significantly differ from the reported values. A putative revised structure in which the pyran ring is opened is proposed for usneoidones. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]


Tree growth is related to light interception and wood density in two mixed dipterocarp forests of Malaysia

FUNCTIONAL ECOLOGY, Issue 3 2005
D. A. KING
Summary 1The development of simple predictors of tree growth is important in understanding forest dynamics. For this purpose, tree height, crown width in two perpendicular directions, trunk diameter at 1·3 m height (d.b.h.) and crown illumination index (CI) were determined for 727 pole-sized trees (8,20 cm d.b.h.) of 21 species, on forest dynamics plots at Pasoh Forest Reserve, Peninsular Malaysia and Lambir Hills National Park, Sarawak, Malaysia. A light-interception index (LI = AcrCI2, where Acr is crown area) was calculated for each tree, and wood density (stem wood dry mass/fresh volume) was estimated for each species from reported values. 2Diameter growth rates were linearly correlated with LI (mean per species r2 = 0·45, excluding substantially damaged and vine-covered trees). 3Among trees of all species, diameter growth rate was highly correlated with LI/wood density. 4Mean growth rate per species varied 10-fold among the study species, but increased linearly with mean LI/wood density ratio (r2 = 0·78), consistent with the previous pattern. 5Thus much of the variability in tree growth rates, both within and among species, can be accounted for by the simple mechanistic assumption that, within a given size class, growth is proportional to light interception/wood density. [source]


Growth of magnetite epitaxial thin films by gas flow sputtering and characterization by FMR

IEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2007
Hiroshi Sakuma Member
Abstract The growth of magnetite (Fe3O4) epitaxial thin films on MgO substrates were studied by using gas flow sputtering (GFS). Reflection high-energy electron diffraction (RHEED) and atomic force microscopy showed that the surfaces of the films obtained at a substrate temperature Ts of 300 °C and oxygen flow rates FO2 of 0.12 , 0.18 sccm are fairly flat for the film thickness of about 200 nm. The saturation magnetization and resistivity were close to the reported values of Fe3O4 for Ts= 300°C and FO2 = 0.12,0.20sccm. The films obtained at Ts= 300°C and FO2=0.16 and 0.18 sccm showed Verwey transition, which is persuasive evidence of the formation of Fe3O4. The epitaxial relationship of Fe3O4(100)//MgO(100) and Fe3O4[100]//MgO[100] was confirmed by using ferromagnetic resonance (FMR), and the anisotropy constants and magnetization were obtained by the fitting of resonance-field versus applied-field angle curves. © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source]


Rate coefficients for the OH + acetaldehyde (CH3CHO) reaction between 204 and 373 K

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 10 2008
Lei Zhu
The rate coefficient, k1, for the gas-phase reaction OH + CH3CHO (acetaldehyde) , products, was measured over the temperature range 204,373 K using pulsed laser photolytic production of OH coupled with its detection via laser-induced fluorescence. The CH3CHO concentration was measured using Fourier transform infrared spectroscopy, UV absorption at 184.9 nm and gas flow rates. The room temperature rate coefficient and Arrhenius expression obtained are k1(296 K) = (1.52 ± 0.15) × 10,11 cm3 molecule,1 s,1 and k1(T) = (5.32 ± 0.55) × 10,12 exp[(315 ± 40)/T] cm3 molecule,1 s,1. The rate coefficient for the reaction OH (, = 1) + CH3CHO, k7(T) (where k7 is the rate coefficient for the overall removal of OH (, = 1)), was determined over the temperature range 204,296 K and is given by k7(T) = (3.5 ± 1.4) × 10,12 exp[(500 ± 90)/T], where k7(296 K) = (1.9 ± 0.6) × 10,11 cm3 molecule,1 s,1. The quoted uncertainties are 2, (95% confidence level). The preexponential term and the room temperature rate coefficient include estimated systematic errors. k7 is slightly larger than k1 over the range of temperatures included in this study. The results from this study were found to be in good agreement with previously reported values of k1(T) for temperatures <298 K. An expression for k1(T), suitable for use in atmospheric models, in the NASA/JPL and IUPAC format, was determined by combining the present results with previously reported values and was found to be k1(298 K) = 1.5 × 10,11 cm3 molecule,1 s,1, f(298 K) = 1.1, E/R = 340 K, and , E/R (or g) = 20 K over the temperature range relevant to the atmosphere. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 635,646, 2008 [source]


Rate constants for H + CH4, CH3 + H2, and CH4 dissociation at high temperature

INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 11 2001
J. W. Sutherland
The Laser Photolysis-Shock Tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reaction, H + CH4 , CH3 + H2, over the temperature range, 928,1697 K. Shock-tube studies on the reverse of this reaction, CH3 + H2 , H + CH4, using CH3I dissociation in the presence of H2 yielded H-atom formation rates and rate constants for the reverse process over the temperature range, 1269,1806 K. These results were transformed (using well-established equilibrium constants) to the forward direction. The combined results for H + CH4 can be represented by an experimental three parameter expression, k = 6.78 × 10,21 T3.156 exp(,4406 K/T) cm3 molecule,1 s,1 (348,1950 K) that was evaluated from the present work and seven previous studies. Using this evaluation, disagreements between previously reported values for the dissociation of CH4 could be reconciled. The thermal decomposition of CH4 was then studied in Kr bath gas. The dissociation results agreed with the earlier studies and were theoretically modeled with the Troe formalism. The energy transfer parameter necessary to explain both the present results and those of Kiefer and Kumaran (J Phys Chem 1993, 97, 414) is, ,,,E,all/cm,1 = 0.3323 T0.7. The low temperature data on the reverse reaction, H + CH3 (in He) from Brouard et al. (J Phys Chem 1989, 93, 4047) were also modeled with the Troe formalism. Lastly, the rate constant for H + CH4 was theoretically calculated using conventional transition state theory with Eckart tunneling corrections. The potential energy surface used was from Kraka et al. (J Chem Phys 1993, 99, 5306) and the derived T-dependence with this method agreed almost perfectly with the experimental evaluation. © 2001 John Wiley & Sons, Inc. Int J Chem Kinet 33: 669,684, 2001 [source]


Outcomes of the International Union of Crystallography Commission on Powder Diffraction Round Robin on Quantitative Phase Analysis: samples 1a to 1h

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2001
Ian C. Madsen
The International Union of Crystallography (IUCr) Commission on Powder Diffraction (CPD) has sponsored a round robin on the determination of quantitative phase abundance from diffraction data. Specifically, the aims of the round robin were (i) to document the methods and strategies commonly employed in quantitative phase analysis (QPA), especially those involving powder diffraction, (ii) to assess levels of accuracy, precision and lower limits of detection, (iii) to identify specific problem areas and develop practical solutions, (iv) to formulate recommended procedures for QPA using diffraction data, and (v) to create a standard set of samples for future reference. Some of the analytical issues which have been addressed include (a) the type of analysis (integrated intensities or full-profile, Rietveld or full-profile, database of observed patterns) and (b) the type of instrument used, including geometry and radiation (X-ray, neutron or synchrotron). While the samples used in the round robin covered a wide range of analytical complexity, this paper reports the results for only the sample 1 mixtures. Sample 1 is a simple three-phase system prepared with eight different compositions covering a wide range of abundance for each phase. The component phases were chosen to minimize sample-related problems, such as the degree of crystallinity, preferred orientation and microabsorption. However, these were still issues that needed to be addressed by the analysts. The results returned indicate a great deal of variation in the ability of the participating laboratories to perform QPA of this simple three-component system. These differences result from such problems as (i) use of unsuitable reference intensity ratios, (ii) errors in whole-pattern refinement software operation and in interpretation of results, (iii) operator errors in the use of the Rietveld method, often arising from a lack of crystallographic understanding, and (iv) application of excessive microabsorption correction. Another major area for concern is the calculation of errors in phase abundance determination, with wide variations in reported values between participants. Few details of methodology used to derive these errors were supplied and many participants provided no measure of error at all. [source]


Synthesis and evaluation of 2-, 4-, 5-substituted nitroimidazole-iminodiacetic acid- 99mTc(CO)3 complexes to target hypoxic tumors

JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 8 2010
Madhava B. Mallia
Abstract Determination of hypoxia in tumor is an important problem in the clinical management of cancer. Towards this, a series of differently substituted nitroimidazoles, viz. 2-nitro, 4-nitro and 5-nitroimidazole iminodiacetic acid (IDA) derivatives were synthesized and radio-labeled with a [99mTc(CO)3(H2O)3]+ core. The corresponding 185/187Re(CO)3 analogue of 2-nitroimidazole-IDA- 99mTc(CO)3 complex was also prepared and characterized to elucidate the mode of bonding between the ligand and the M(CO)3 core (M=99mTc, 185/187Re). All the three nitroimidazole-IDA- 99mTc(CO)3 complexes could be prepared in over 95% yield determined by HPLC. The three complexes were then evaluated in a suitable animal model bearing tumor. Though the in vivo accumulation of complexes in hypoxic tissue is governed by factors such as lipophilicity, charge, etc., the variation in accumulation in hypoxic tissue, in the present case, could be explained by considering the reported values of single electron reduction potential of the respective nitroimidazoles. Among the three derivatives studied, the 2-nitroimidazole-IDA- 99mTc(CO)3 complex produced the best result followed by the 5-nitroimidazole complex. Copyright © 2010 John Wiley & Sons, Ltd. [source]


Interpretation of the temperature dependence of equilibrium and rate constants

JOURNAL OF MOLECULAR RECOGNITION, Issue 5 2006
Donald J. Winzor
Abstract The objective of this review is to draw attention to potential pitfalls in attempts to glean mechanistic information from the magnitudes of standard enthalpies and entropies derived from the temperature dependence of equilibrium and rate constants for protein interactions. Problems arise because the minimalist model that suffices to describe the energy differences between initial and final states usually comprises a set of linked equilibria, each of which is characterized by its own energetics. For example, because the overall standard enthalpy is a composite of those individual values, a positive magnitude for ,Ho can still arise despite all reactions within the subset being characterized by negative enthalpy changes: designation of the reaction as being entropy driven is thus equivocal. An experimenter must always bear in mind the fact that any mechanistic interpretation of the magnitudes of thermodynamic parameters refers to the reaction model rather than the experimental system For the same reason there is little point in subjecting the temperature dependence of rate constants for protein interactions to transition-state analysis. If comparisons with reported values of standard enthalpy and entropy of activation are needed, they are readily calculated from the empirical Arrhenius parameters. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Spectroscopic investigations and computational study of 2-[acetyl(4-bromophenyl)carbamoyl]-4-chlorophenyl acetate

JOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2010
C. Yohannan Panicker
Abstract The Fourier transform Raman (FT-Raman) and Fourier transform infrared (FT-IR) spectra of 2-[acetyl(4-bromophenyl)carbamoyl]-4-chlorophenyl acetate were studied. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution (PED) calculations. The simultaneous Raman and infrared (IR) activations of the CO stretching mode in the carbamoyl moiety show a charge transfer interaction through a ,-conjugated path. From the optimized structure, it is clear that the hydrogen bonding decreases the double bond character of the CO bond and increases the double bond character of the CN bonds. The first hyperpolarizability and predicted IR intensities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar structures, which makes this compound an attractive object for future studies of nonlinear optics. Optimized geometrical parameters of the compound are in agreement with similar reported structures. Copyright © 2009 John Wiley & Sons, Ltd. [source]


The dynamics of gene products fluctuation during bovine pre-hatching development

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2009
Isabelle Gilbert
Early embryonic development, spanning fertilization to blastocyst hatching, is a very dynamic developmental window that is characterized, especially in large mammals, by a period of transcriptional incompetence that ends during the maternal to embryonic transition (MET). Prior to the MET, the first cell cycles are supported by stored RNA and proteins pools accumulated during oogenesis. Therefore, RNA and protein content are different between developmental stages. It is also known that the stability of the stored mRNA and the mechanisms for translation recruitment are partly controlled by the length of the poly(A) tail. To date, little is known about RNA and protein content fluctuations during the pre-hatching period. In this report we present measurements of total RNA, mRNA, poly(A) bearing mRNA and protein contents, as well as estimations of the proportions of both mRNA fractions to total RNA contents within these developmental stages. We found that while the ontogenic profiles of the different transcript contents were expected, their amounts were considerably lower than the reported values. Additionally, low 28S rRNA abundance and a tendency for diminishing protein content prior to the MET, suggest a limited potential for ribosomal turnover and translation. We consider the overall fluctuations in RNA and protein contents to be reference points that are essential for downstream interpretation of gene expression data across stages whether it be through candidates or high throughput approaches. Mol. Reprod. Dev. 76: 762,772, 2009. © 2009 Wiley-Liss, Inc. [source]


Some Issues on Core-Annulus and Cluster Models of Circulating Fluidized Bed Reactors

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 5 2002
Hsiaotao T. BiArticle first published online: 19 MAY 200
Abstract The one-dimensional cluster model and the core-annulus model are examined based on existing correlations. The core-annulus model is found to give reasonable agreement with ozone decomposition data when the effective interphase mass transfer rate constant is equal to about 0.1 1/s, which is one order smaller than the reported values based on gas tracer tests. The prediction from the core-annulus model that the reactor performance decreases with increasing the riser diameter is found to be inconsistent with limited experimental data The one-dimensional cluster model predicts that a riser reactor performs very close to the pseudo-homogeneous plug flow reactor because of the high mass transfer rate between the cluster and the dilute phase. The improvement of model predictions lies in the better characterization of the cluster shape, size and the mass transfer rate between the cluster and the dilute phases. Le modèle de grappes unidimensionnel et le modèle c,ur-espace annulaire sont examinés d'après des corrélations existantes. On a trouvé que le modèle c,ur-espace annulaire décrivait raisonnablement bien les données de décomposition de l'ozone lorsque la constante de taux de transfert de matière entre phases réelle est égale à environ 0,1 s-1, ce qui est d'un ordre de grandeur plus petit que les valeurs obtenues d'après des tests par gaz traceurs. La prédiction du modèle c,ur-espace annulaire selon laquelle la performance du réacteur diminue avec l'augmentation du diamètre de la colonne montante s'avère non cohérente avec les quelques données expérimentales. Le modèle de grappes unidimensionnel prédit que la performance d'un réacteur à colonne montante est très proche de celle d'un réacteur à écoulement piston pseudo-homogène du fait du taux de transfert de matière élevé entre la grappe et la phase diluée. L'amélioration des prédictions du modèle repose sur une meilleure caractérisation de la forme des grappes, de leur taille et du taux de transfert de matière entre les grappes et les phases diluées. [source]


Bioequivalence assessment of Azomycin® (Julphar, UAE) as compared to Zithromax® (Pfizer, USA),two brands of azithromycin,in healthy human volunteers

BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 1 2001
Naji M. Najib
Abstract Two studies have been performed to assess the relative bioavailability of Azomycin® (Julphar, UAE) as compared with Zithromax® (Pfizer, USA) at the International Pharmaceutical Research Center (IPRC), Amman, Jordan. One study involved Azomycin® capsules and the other Azomycin® suspension. Each study enrolled 24 volunteers and in both studies, after an overnight fasting, the two brands of azithromycin were administered as single dose on two treatment days separated by a 2 weeks washout period. After dosing, serial blood samples were collected for a period of 192 h. Plasma harvested from blood, was analysed for azithromycin by HPLC coupled with electrochemical detection. Various pharmacokinetic parameters including AUC0,t, AUC0,,,Cmax, Tmax, T1/2 and Kelm were determined from plasma concentrations for both formulations and found to be in good agreement with the reported values. AUC0,t, AUC0,, and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence intervals for the test/reference ratios of these parameters were found within the bioequivalence acceptance range of 80,125%. Based on these statistical inferences it was concluded that Azomycin® capsule is bioequivalent to Zithromax® capsule and Azomycin® suspension is bioequivalent to Zithromax® suspension. Copyright © 2001 John Wiley & Sons, Ltd. [source]