bluuebunny/crossref_metadata_2025 huggingface dataset:
Computer‐Aided Molecular Design of Environmentally Friendly Solvents for Separation Processes
Authors: Song J. , Song H.‐H.
Published: January 2008

This review paper presents an optimization technology for the computer‐aided molecular design of environmentally friendly solvents. The approach combines a stochastic optimization method and group contribution methods (GC‐methods) to design solvents with desirable physicochemical and environmental properties. A simulated annealing algorithm is used to investigate feasible molecular structures. The main objective method is adopted to balance the multi‐objective functions. One property is chosen as the main objective function, while the other properties are considered as constraints, and thus, the multi‐objective problem is transformed into a single objective one. The optimal solution is a set of molecules satisfying the formulated target. The properties of each molecule are evaluated through GC‐methods, including pure component properties, mixture properties and environmentally properties. Finally, the proposed methodology is illustrated with several examples of industrial separations.
Particle Holdup and Average Residence Time in the Cyclone of a CFB Boiler
Authors: Li S. H. , Yang S. , Yang H. R. , Zhang H. , Liu Q. , Lu J. F. , Yue G. X.
Published: January 2008

Particle holdup and the average residence time in the cyclone of a Circulating Fluidized Bed (CFB) boiler are important information for describing events post‐combustion in the cyclone that often lead to a noticeable increase in the temperature of the flue gas. The existing results for the variation of particle average residence time with fluidizing gas velocity are contradictory since they were obtained under different operation conditions. A cold CFB apparatus made of plexiglass was established with a riser of 5 m in height and 0.2 m in diameter and equipped with a standard Lapple cyclone. The particle holdup was directly measured by the mass in the cyclone when the system was shut down. The solid concentration at the cyclone inlet was kept in the range generally used in CFB boilers. The experimental results showed that the particle holdup in the cyclone was equal to ca. 10–40 % of the corresponding bed material in the riser and that it increases monotonously with both the fluidizing gas velocity and the initial static bed height, and approximately linearly with the solid circulation rate. In addition, within the experimental conditions, the cyclone pressure drop increases monotonously with particle holdup. It was found that the average residence time of the particles either increased or decreased linearly with the fluidizing gas velocity, depending on the initial static bed height. Nevertheless, both variation rates were very small. In a view of engineering applications, the average residence time of the particles in the cyclone is insignificantly affected by the fluidizing gas velocity, initial bed inventory and solid circulation rate, within the range of experimental conditions examined.
Simultaneous Application of Penetration Theory to Both Small and Large Bubbles Formed in a Column Operated Under Heterogeneous Regime
Authors: Nedeltchev S.
Published: January 2008

The article deals with the simultaneous application of the classical penetration theory to both oblate ellipsoidal and spherical‐cap bubbles coexisting in the heterogeneous (churn‐turbulent) regime of bubble column operation. The theoretical volumetric liquid‐phase mass transfer coefficients, kLa (referred to dispersion volume), for both small and large bubbles were first calculated by means of the classical penetration theory and then corrected due to the nonspherical bubble shape. The correction procedure developed by Nedeltchev et al. [1–3] has been successfully applied. Two new correction factors, $ f_{\rm oe}^{\rm het} $ (for the small ellipsoidal bubbles) and $ f_{\rm sc}^{\rm het} $ (for the large spherical‐cap bubbles), were introduced. $ f_{\rm oe}^{\rm het} $ was correlated to the Eötvös number. Eo, whereas $ f_{\rm sc}^{\rm het} $ was correlated to the constant large bubble aspect ratio.

For the verification of this concept, kLa values in 15 different organic liquids and 7 preadjusted liquid mixtures were used (see Öztürk et al. [4]). The overall kLa values were estimated as a sum of both kLa values for the small (oblate ellipsoidal) bubbles and kLa values for the large (spherical‐cap) bubbles. Each theoretical kLa value was multiplied by the corresponding correction term. As many as 102 experimental kLa values were predicted successfully with an average relative error of 7.1 %.
Volume Image Analysis of Ceramic Sponges
Authors: Große J. , Dietrich B. , Martin H. , Kind M. , Vicente J. , Hardy E. H.
Published: January 2008

The three‐dimensional structure of monolithic networks such as ceramic sponges and their geometrical dimensions are part of the fundamentals necessary for investigation in most possible applications in chemical engineering. A volume imaging method must be applied to determine this structure and to measure features such as the specific surface area and the pore diameter. Magnetic Resonance Imaging was chosen for such measurements in this study. The analysis of volume images is performed with various methods based on different principles, which are compared with each other as well as with data generated by conventional techniques and from literature models.
Synthesis of (+)‐Obtusenyne
Authors: Mak S. Y. Frankie , Curtis Neil R. , Payne Andrew N. , Congreve Miles S. , Wildsmith Andrew J. , Francis Craig L. , Davies John E. , Pascu Sofia I. , Burton Jonathan W. , Holmes Andrew B.
Published: January 2008

An enantioselective synthesis of the halogenated medium‐ring ether natural product (+)‐obtusenyne is reported which uses the ring expansion of a seven‐membered ketene acetal by means of a Claisen rearrangement to construct the core nine‐membered oxygen heterocycle. The trans substituents across the ether linkage were established by using a transition‐metal‐catalyzed intramolecular hydrosilation reaction of an exo‐cyclic enol ether. In addition, a formal synthesis of ent‐obtusenyne from 2‐deoxy‐D‐ribose is reported. A number of interesting points regarding the chemistry of medium‐ring oxygen heterocycles are highlighted.
Rechnergestützter konzeptioneller Entwurf von Destillations‐/ Reaktionsprozessen
Authors: Ryll O. , Blagov S. , Hasse H.
Published: January 2008

In der vorliegenden Arbeit wird ein neues Werkzeug für den rechnergestützten konzeptionellen Entwurf von Destillations‐/Reaktionsprozessen vorgestellt. Dieses liefert für ein aus beliebig vielen Destillationskolonnen und Reaktoren bestehendes vorgegebenes Verfahrensfließbild, vorgegebene Einsatzströme und Produktspezifikationen nicht nur eine Aussage über die Machbarkeit des Prozesses sondern auch eine vollständige Stromleiste für realisierbare Prozesse. Ferner ist es möglich, für diese Prozesse einen vollständigen Überblick über den Lösungsraum zu erhalten, bei dem auch Mehrfachlösungen identifiziert werden können. Die verwendete Methode basiert auf einer Betrachtung thermodynamischer Grenzfälle. Zur Beschreibung der Destillation wird die ∞/∞‐Analyse eingesetzt. Die Beschreibung der thermodynamischen Stoffdaten erfolgt mit gängigen Modellen ohne vereinfachende Annahmen. Die Methode liefert auch exzellente Startwerte für die nachfolgende detaillierte Prozesssimulation. Das Werkzeug wurde bereits erfolgreich bei der Entwicklung eines industriellen Verfahrens eingesetzt.
„Der Kolonnenflüsterer”︁: Wesentliche Aspekte für ein erfolgreiches Troubleshooting
Authors: Meier R. , Rix A. , Demicoli D.
Published: January 2008

Obwohl die Destillation als das mit Abstand bedeutendste Verfahren zur Zerlegung von Flüssigkeitsgemischen gilt, lassen sich in der industriellen Praxis immer wieder Kolonnen beobachten, die ihre Funktion nicht optimal ausführen. Während kleinere Fehlfunktionen im täglichen Betrieb häufig noch über das Ausreizen von im Design berücksichtigten Sicherheitszuschlägen kaschiert werden, kommt es vereinzelt vor, dass Kolonnensysteme komplett versagen. Häufig sind dabei die Ursachen für die Fehlfunktion nicht offensichtlich. Das Troubleshooting dieser Problemfälle beginnt mit einer detaillierten Analyse des Problems und erstreckt sich von der Auffindung von Symptomen bis hin zur Verifizierung der tatsächlichen Ursache. Im Artikel werden anhand ausgewählter Praxisbeispiele Lösungswege für ein erfolgreiches Troubleshooting vorgestellt. Neben den eigentlichen Ursachen werden methodische Aspekte diskutiert und darauf aufbauend die nötigen Anforderungen an den Troubleshooter abgeleitet.
Optimale Betriebsführung durch modellbasierte online‐Steuerung
Authors: Wendt M. , Strack M. , Arellano‐Garcia H.
Published: January 2008

Die optimale Steuerung von chemischen Produktionsanlagen ist bei starken Änderungen der Randbedingungen und Prozessspezifikationen während des laufenden Betriebs eine hohe Herausforderung. Als Lösungsansatz wird hier die praktische Umsetzung der Methodiken für online‐Simulation und Optimierung vorgestellt. Der online‐Betrieb einer Destillationskolonne im Chemiepark Knapsack zeigt die Robustheit der Konzeption.
Untersuchungen zur Reaktivextraktion mit ionischen Flüssigkeiten
Authors: Naydenov D. , Bart H.‐J.
Published: January 2008

Die zweiphasige Veresterung mit ionischen Flüssigkeiten (IL) wurde untersucht, wobei eins der Edukte besser in der organischen und das andere besser in der ionischen Phase löslich ist. Experimente und Simulationen ergaben, dass die IL [EMIM] [HSO4] als Katalysator und Lösungsmittel für die zweiphasige Veresterung von Ethanol mit Essigsäure verwendet werden kann. Bei Gegenstromführung der organischen und ionischen Phasen in einem mehrstufigen Prozess und Einspeisen der Edukte auf benachbarten Stufen ergaben sich hohe Reaktionsumsätze (96 %). Vorteile des vorgeschlagenen Prozesses sind das Potenzial zur Kostenreduktion gegenüber herkömmlichen Methoden und Rückführbarkeit des Katalysators. Die Ergebnisse lassen sich auf Systeme mit ähnlichem Phasenverhalten übertragen.
Optimierung von Proteinaufreinigungsprozessen basierend auf einem generischen Prozessmodell
Authors: Frerick C. , Kreis P. , Górak A.
Published: January 2008

In dieser Arbeit wird ein generisches Prozessmodell zur dynamischen Simulation von Proteinaufreinigungsprozessen vorgestellt. Durch dessen Kopplung mit einem evolutionären Optimierungsalgorithmus können die Sequenz und das Design der Grundoperationen von Aufreinigungsprozessen auf Basis detaillierter Modelle simultan optimiert werden. Die Anwendbarkeit dieses Optimierungswerkzeugs wird anhand eines Beispielprozesses zur Aufreinigung von humanem Serumalbumin demonstriert.
Neuerungen und Erfahrungen aus der Anwendung des CAPE‐OPEN Standards
Authors: von Wedel L.
Published: January 2008

Die Möglichkeiten der Prozessmodellierung und der Analyse der Modelle mittels Simulation und Optimierung haben in den letzten Jahren stark zugenommen. Vor allem neue, spezielle Lösungsmethoden werden vorrangig durch kleinere Anbieter abgedeckt, während die großen Anbieter den Bereich der Standardlösungsmethoden, etwa der Fließbildsimulation, unter sich aufteilen. Lange Zeit konnten diese beiden Bereiche nicht sinnvoll oder nur mit hohem Aufwand miteinander kombiniert werden. 1997 wurde daher das CAPE‐OPEN‐Projekt gestartet, um die Erweiterbarkeit und Interoperabilität von Prozesssimulatoren zu verbessern. 10 Jahre später bietet es sich an, einen Rückblick zu wagen, den derzeitigen Stand der Entwicklung zusammenzufassen und offene Punkte für die Zukunft kritisch zu hinterfragen. Nach einer Einführung fasst dieser Artikel die Historie von CAPE‐OPEN kurz zusammen und beschreibt die wesentlichen Elemente des Standards. Die technischen Grundlagen des Standards werden erläutert sowie über COLaN berichtet, der Organisation, die hinter dem CAPE‐OPEN‐Standard steht. Zuguterletzt wird ein kritischer Ausblick für die Zukunft gegeben.
Hybride Trennverfahren: Verschaltung von Reaktivrektifikation und Dampfpermeation
Authors: Buchaly C. , Kreis P. , Górak A.
Published: January 2008

Das Prozessverhalten hybrider Trennverfahren zur Synthese von Propylpropionat wird am Beispiel der Verschaltung einer Reaktivrektifikationskolonne mit der Dampfpermeation untersucht. Der vorliegende Beitrag zeigt zum einen die experimentelle Validierung der verwendeten Grundoperationen im Technikumsmaßstab sowie eine Untersuchung der zu einem Hybridverfahren verschalteten Einzelprozesse. Zum anderen wird ein Einblick in die Modellierung, Simulation und Optimierung hybrider Trennverfahren unter Verwendung detaillierter Stoffaustauschmodelle gegeben.
Zum Einsatz der Partikelmesstechnik in der Prozessintensivierung
Authors: Ruscitti O. , Franke R. , Hahn H. , Babick F. , Richter T. , Stintz M.
Published: January 2008

Der Wettbewerbsdruck in der chemischen Industrie macht es notwendig, Maßnahmen zu ergreifen, durch die Prozesse drastisch verbessert werden, um auch zukünftig wettbewerbsfähig zu bleiben. Der Entwicklung und Implementierung derartiger, prozessintensivierender Maßnahmen geht zweckmäßigerweise eine ganzheitliche Analyse des betreffenden Prozesses voraus. Am Beispiel eines Zerkleinerungsprozesses für einen partikulären Wirkstoff wird diese Vorgehensweise veranschaulicht. Durch den Einsatz zweier komplementärer Methoden der Partikelmesstechnik, der Ultraschallspektroskopie und der Laserbeugung werden Korrelationen zwischen Dispersitätsmerkmalen und Qualitätsmerkmalen des Produkts gefunden. Sowohl die Effizienz von Zerkleinerungsapparaten aber auch die des Prozesses können so bewertet werden. Die Ultraschallspektroskopie kann als Messmethode zur lokalen Prozesskontrolle eingesetzt werden.
Practical guidelines for the management of interferon‐α‐2b side effects in patients receiving adjuvant treatment for melanoma
Authors: Hauschild Axel , Gogas Helen , Tarhini Ahmad , Middleton Mark R. , Testori Alessandro , Dréno Brigitte , Kirkwood John M.
Published: January 2008

Interferon‐α‐2b (IFNα2b) is the only effective adjuvant therapy for melanoma patients at high risk of recurrence that has been approved by regulatory authorities worldwide. However, IFN toxicities increase the risk of poor treatment compliance and impair the potential for benefit from this agent. A review of the literature demonstrated little recent attention to supportive care in the management of IFN toxicities. An international group of experts with extensive personal experience in the use of IFNs worked together to develop practical guidelines for the use of IFNs. Practical recommendations were developed for patient education on the use of IFN; initial patient assessment and monitoring, including contraindications to the use of IFN, monitoring and managing adverse events, and IFN dose modification and discontinuation; IFN injection procedures; treatment of elderly patients; and use during pregnancy and nursing. Successful adjuvant therapy of melanoma with high‐dose IFN requires close compliance with the treatment regimen. Recommendations for the recognition and management of adverse events are designed to enable more patients to complete the full planned course of treatment. Cancer 2008. © 2008 American Cancer Society.
“Limited” prostate cancer on biopsy
Authors: Schlegel Peter N.
Published: January 2008

The excellent meta‐analysis in this issue of Cancer by Harnden and colleagues confirms that prostate biopsy provides an incomplete evaluation of prostate cancer volume. Even at its earliest defined state of detection, prostate cancer may be an advanced process. These observations suggest concern with the process of active surveillance for “early” or “minimal” prostate cancers.
Proton and Deuteron Transfer Reactions in Molecular Nanoclusters
Authors: Kim Hyojoon , Kapral Raymond
Published: January 2008

Proton and deuteron transfer rates and mechanisms are studied in polar molecular nanoclusters. The cluster environment strongly influences the reaction rate and the nature of these changes is studied as a function of the cluster size. The stabilities of the covalent reactant and polar product states change with cluster size and this effect alters both the equilibrium properties and transfer rate. The proton and deuteron are light quantum particles and the quantum character of the rate process is reflected in the magnitude of the kinetic isotope effect. Our mixed quantum–classical rate simulations indicate that the magnitude of the isotope effect decreases as the cluster size increases. More generally, our study shows how quantum effects combined with structural nanosolvation effects can lead to changes in reaction rates and mechanisms which should be applicable to many quantum charge transfer reactions in molecular nanoclusters.
Gait characteristics of diabetic patients: a systematic review
Authors: Allet L. , Armand S. , Golay A. , Monnin D. , de Bie R. A. , de Bruin E. D.
Published: January 2008

Patients with diabetes are at higher risk of experiencing fall‐related injuries when walking than healthy controls. The underlying mechanism responsible for this is not yet clear. Thus we intend to summarize diabetic patients' gait characteristics and emphasize those which could be the possible underlying mechanisms for increased fall risk. This systematic review aims, in particular, to: (1) evaluate the quality of existing studies which investigate the gait characteristics of diabetic patients, (2) highlight areas of agreement and contradiction in study results, (3) discuss and emphasize parameters associated with fall risk, and (4) propose new orientations and further domains for research needed for their fall risk prevention. We conducted an electronic search of Pedro, PubMed, Ovid and Cochrane. Two authors independently assessed all abstracts. Quality of the selected articles was scored, and the study results summarized and discussed. We considered 236 abstracts of which 28 entered our full text review. Agreement on data quality between two reviewers was high (kappa: 0.90). Authors investigating gait parameters in a diabetic population evaluated in particular parameters either associated with fall risk (speed, step length or step‐time variability) or with ulcers (pressure). There is agreement that diabetic patients walk slower, with greater step variability, and present higher plantar pressure than healthy controls. We concluded that diabetic patients present gait abnormalities, some of which can lead to heightened fall risk. To understand its' underlying mechanisms, and to promote efficient prevention, further studies should analyse gait under ‘real‐life’ conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Severe eating disorder initially diagnosed in a 72‐year‐old man
Authors: Manejías Parke Susan G. , Yager Joel , Apfeldorf William
Published: January 2008

Objective:

Eating disorders in our society mainly affect young women. Cases in males are far less common, and reported cases in elderly males are rare.

Method:

We report the case of 72‐year‐ old male admitted to a geriatric psychiatry service for grave passive neglect with mild dementia thought to be due to nutritional deficiency.

Results:

The patient was found to have an eating disorder not otherwise specified, most closely resembling anorexia nervosa, which was believed to be the cause of the nutritional problem.

Conclusion:

This case highlights the need for diagnostic awareness regarding eating disorders in patients of all ages and of both genders. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2008
The genetics of anorexia nervosa collaborative study: Methods and sample description
Authors: Kaye Walter H. , Bulik Cynthia M. , Plotnicov Katherine , Thornton Laura , Devlin Bernie , Fichter Manfred M. , Treasure Janet , Kaplan Allan , Woodside D. Blake , Johnson Craig L. , Halmi Katherine , Brandt Harry A. , Crawford Steve , Mitchell James E. , Strober Michael , Berrettini Wade , Jones Ian
Published: January 2008

Objective:

Supported by National Institute of Mental Health (NIMH), this 12‐site international collaboration seeks to identify genetic variants that affect risk for anorexia nervosa (AN).

Method:

Four hundred families will be ascertained with two or more individuals affected with AN. The assessment battery produces a rich set of phenotypes comprising eating disorder diagnoses and psychological and personality features known to be associated with vulnerability to eating disorders.

Results:

We report attributes of the first 200 families, comprising 200 probands and 232 affected relatives.

Conclusion:

These results provide context for the genotyping of the first 200 families by the Center for Inherited Disease Research. We will analyze our first 200 families for linkage, complete recruitment of roughly 400 families, and then perform final linkage analyses on the complete cohort. DNA, genotypes, and phenotypes will form a national eating disorder repository maintained by NIMH and available to qualified investigators. © 2008 by Wiley Periodicals, Inc. Int J Eat Disord 2008
The Synthesis, Structures and Characterisation of New Mixed‐Ligand Manganese and Iron Complexes with Tripodal, Tetradentate Ligands
Authors: van Gorkum Remy , Berding Joris , Mills Allison M. , Kooijman Huub , Tooke Duncan M. , Spek Anthony L. , Mutikainen Ilpo , Turpeinen Urho , Reedijk Jan , Bouwman Elisabeth
Published: January 2008

The preparation of new manganese and iron complexes with the general formula [M(tripod)(anion)] is described, where M = FeIII or MnIII, “tripod” is a dianionic tetradentate tripodal ligand and the anion is a chelating β‐diketonate, 8‐oxyquinoline or acetate. The synthesis of this type of complexes was found to be straightforward, which allows for the preparation of a large variety of such coordination compounds. The complexes are characterised by X‐ray crystallography, infrared spectroscopy, UV/Vis spectroscopy, cyclic voltammetry and elemental analysis. A correlation between the ligand sets and the electron density at the metal centre in the complexes is proposed, based on the UV/Vis data and the CV measurements. The tripodal ligands are significant π‐donor ligands, and electron‐withdrawing or electron‐donating substituents on the phenolate arms were found to have a large influence on both the position of the d–d transitions in the UV/Vis spectra and the peak potentials in the CV measurements. The “secondary” β‐diketonate or acetate ligand does not have such a large effect on the electron density of the metal centre.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Theoretical Investigation on the Mechanism of Oxygen Atom Transfer between Two Non‐Heme Iron Centres
Authors: de Visser Sam P. , Lee Yong‐Min , Nam Wonwoo
Published: January 2008

Density functional theory calculations are presented on the oxygen atom transfer reaction between two non‐heme iron centres: One contains Bn–tpen [N‐benzyl‐N,N′,N′‐tris(2‐pyridylmethyl)ethane‐1,2‐diamine], whereas the other contains N4Py [N,N‐bis(2‐pyridylmethyl)‐N‐bis(2‐pyridyl)methylamine]. The calculations show that the (Bn–tpen)Fe–O–Fe(N4Py) complex is a stable entity but considerably higher in energy than isolated species. However, a mechanism of oxygen atom transfer from one non‐heme iron centre to the other will proceed via this oxido‐bridged intermediate. This oxido‐bridged complex has both iron atoms in oxidation state III so that in the process of the formation of the complex, an electron transfer from the FeII centre to the FeIV(O) centre has taken place. Nevertheless, both metal atoms have different orbital and spin‐density occupation. A large solvent effect on the reaction barriers is obtained, indicating that the reaction proceeds only in very polar environments.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Three‐dimensional VS profiling using microtremors in Kushiro, Japan
Authors: Arai Hiroshi , Tokimatsu Kohji
Published: January 2008

A practical method is presented for determining three‐dimensional S‐wave velocity (VS) profile from microtremor measurements. Frequency–wave number (f–k) spectral analyses of microtremor array records are combined, for this purpose, with microtremor horizontal‐to‐vertical (H/V) spectral ratio techniques. To demonstrate the effectiveness of the proposed method, microtremor measurements using arrays of sensors were conducted at six sites in the city of Kushiro, Japan. The spectral analyses of the array records yield dispersion characteristics of Rayleigh waves and H/V spectra of surface waves, and joint inversion of these data results in VS profiles down to bedrock at the sites. Conventional microtremor measurements were performed at 230 stations within Kushiro city, resulting in the H/V spectra within the city. Three‐dimensional VS structure is then estimated from inversion of the H/V spectra with the VS values determined from the microtremor array data. This reveals three‐dimensional VS profile of Kushiro city, together with an unknown hidden valley that crosses the central part of the city. The estimated VS profile is consistent with available velocity logs and results of subsequent borings, indicating the effectiveness of the proposed method. Copyright © 2008 John Wiley & Sons, Ltd.
Comment on ‘Scale relationships in hillslope runoff and erosion’ (Earth Surface Processes and Landforms 31: 1364–1383 (2006))
Authors: Kinnell P. I. A.
Published: January 2008

An analysis of the data obtained by Parsons et al. (2006a) on runoff and erosion plots in Arizona did not support the conclusion of the authors that the pattern of sediment yield for these plots first increased as plot length increased but then decreased. The approach adopted by the authors was not appropriate for analysing the data from a small number (10) of rainfall events where data were missing from many of the plots because of technical failures. Also, for a proper analysis of the effect of plot length to be undertaken, a shorter plot has to appear to physically represent the top portion of a longer plot. However, the events were spatially and temporally very localized, as they varied in intensity, duration, total rainfall, time to peak etc between the plots. Under these circumstances, data obtained from these experiments cannot be used to determine the effect of slope length on sediment yield. Copyright © 2008 John Wiley & Sons, Ltd.
Foredune vegetation patterns and alongshore environmental gradients: Moçambique Beach, Santa Catarina Island, Brazil
Authors: Silva Graziela Miot da , Hesp Patrick , Peixoto Janice , Dillenburg Sérgio R.
Published: January 2008

This paper examines patterns of foredune vegetation along an embayment in southern Brazil and the relationships between variations in percent cover and diversity, and environmental factors such as beach/surfzone type and exposure to wind and wave energy. The study was conducted on Moçambique Beach, Brazil, which displays significant alongshore variations in exposure to the prevailing winds and waves, beach/surfzone morphodynamic type, type and dimensions of the dune systems and foredune vegetation cover and diversity. Two vegetation surveys were carried out in contiguous 1 m2 quadrats across the foredune. The presence/absence, percent cover of the species, diversity and similarity between the vegetation of the profiles surveyed and their relation with environmental conditions are examined. The results show that the vegetation cover decreases from south to north, possibly reflecting the increasing exposure to wind and wave energy. Distinct patterns of species distributions occur along Moçambique beach, such that different plant species are dominant on the southern, middle and northern ends of the beach. A cluster analysis demonstrated two associations: the first one is represented by the profiles located in the lower energy zone of the beach, and the second association is represented by the profiles more exposed to wind and wave energy, sediment deposition and salt spray. The diversity of species decreases northwards, possibly influenced by the surfzone type, number of breaking waves and degree of aeolian transport. The presence/absence of the species and the vegetation cover on the foredune reflect the varying levels of exposure of the beach and foredune to the winds and waves and also reflect the volume of sediment deposition on the foredune and the beach mobility determined by the morphodynamic beach/surfzone type. Copyright © 2008 John Wiley & Sons, Ltd.
PEMFC Performance in a Magnetic Field
Authors: Matsushima H. , Iida T. , Fukunaka Y. , Bund A.
Published: January 2008

A polymer electrolyte fuel cell is operated in a magnetic field gradient (B × dB/dx = ±3 T2�m–1) and the power output is investigated at lower partial pressure of oxygen gas and lower temperature than customarily used in fuel cells. The effects of the magnetic field are not confirmed at the cell current of i < 12 mA cm–2. On the other hand, the cell performance is improved or deteriorated depending on the direction of the magnetic field gradient at higher current densities at which the mass transfer of oxygen gas is limited by diffusion. The results suggest that the magnetic field influences the diffusion process of the oxygen molecules rather than the catalysis.
Potentially inappropriate management of depressive symptoms among Ontario home care clients
Authors: Dalby Dawn M. , Hirdes John P. , Hogan David B. , Patten Scott B. , Beck Cynthia A. , Rabinowitz Terry , Maxwell Colleen J.
Published: January 2008

Objective

To examine the prevalence and correlates of potentially inappropriate pharmacotherapy (including potential under‐treatment) for depression in adult home care clients.

Methods

A cross‐sectional study of clients receiving services from Community Care Access Centres in Ontario. Three thousand three hundred and twenty‐one clients were assessed with the Resident Assessment Instrument for Home Care (RAI‐HC). A score of 3 or greater on the Depression Rating Scale (DRS), a validated scale embedded within the RAI‐HC, indicates the presence of symptoms of depression. Medications listed on the RAI‐HC were used to categorize treatment into two groups: potentially appropriate and potentially inappropriate antidepressant drug therapy. Adjusted logistic regression models were used to explore relevant predictors of potentially inappropriate pharmacotherapy.

Results

12.5% (n = 414) of clients had symptoms of depression and 17% received an appropriate antidepressant. Over half of clients (64.5%) received potentially inappropriate pharmacotherapy (including potential under‐treatment). Age 75 years or older, higher levels of caregiver stress and the presence of greater comorbidity were associated with a higher risk of potentially inappropriate pharmacotherapy in multivariate analyses. Documentation of any psychiatric diagnosis on the RAI‐HC and receiving more medications were significantly associated with a greater likelihood of appropriate drug treatment.

Conclusion

Most clients with significant depressive symptoms were not receiving appropriate pharmacotherapy. Having a documented diagnosis of a psychiatric condition on the RAI‐HC predicted appropriate pharmacotherapy. By increasing recognition of psychiatric conditions, the use of standardized, comprehensive assessment instruments in home care may represent an opportunity to improve mental health care in these settings. Copyright © 2008 John Wiley & Sons, Ltd.
Impacts of the basin‐wide Indian Ocean SSTA on the South China Sea summer monsoon onset
Authors: Yuan Yuan , Zhou Wen , Chan Johnny C. L. , Li Chongyin
Published: January 2008

This article explores the impacts of the Indian Ocean basin‐scale sea surface temperature anomaly (SSTA) on the South China Sea (SCS) summer monsoon onset. Basin‐wide warming in the tropical Indian Ocean (TIO) is found to occur in the spring following an El Niño event, and the opposite occurs for a La Niña event. Such changes of the Indian Ocean SSTA apparently prolong the El Niño‐Southern Oscillation (ENSO) effects on the subsequent Asian summer monsoon, mainly through modifying the strength of the Philippine Sea anti‐cyclone.

Warming in the TIO induces an anomalous reversed Walker circulation over the tropical Indo–Pacific Ocean, which leads to descending motion, and hence suppressed convection in the western Pacific. The intensified Philippine Sea anti‐cyclone in May and June advances more westward and prevents the extension of the Indian Ocean westerly flow into the SCS region, thereby causing a late SCS monsoon onset. The case is opposite for the TIO cooling such that the Philippine Sea anti‐cyclone weakens and retreats eastward, thus favouring an early onset of the SCS monsoon. Copyright © 2008 Royal Meteorological Society
Risk factors for recurrence of primary sclerosing cholangitis after liver transplantation
Authors: Cholongitas Evangelos , Shusang Vibhakorn , Papatheodoridis George V. , Marelli Laura , Manousou Pinelopi , Rolando Nancy , Patch David , Rolles Keith , Davidson Brian , Burroughs Andrew K.
Published: January 2008

Liver transplantation (LT) is the only therapeutic option for end-stage primary sclerosing cholangitis (PSC), but PSC can recur (rPSC) in some patients after LT. The aim of our study was to evaluate the risk factors associated with rPSC. Between 1989 and 2004, 69 patients receiving transplantation for PSC (42 male, mean age 41.9 yr). Clinical and laboratory data, activity/extension and treatment of ulcerative colitis (UC), post-LT cytomegalovirus (CMV) infection, and immunosuppression were evaluated. Determination of rPSC was made by radiological and histological findings. Exclusion criteria were ABO blood group incompatibility, hepatic artery stenosis, and biliary strictures occurring in <3 months post-LT. A total of 48 (70%) patients had PSC and UC pre-LT. rPSC occurred in 7 of 53 (13.5%, 2 patients with de novo UC) who were alive 1 yr after LT and/or met inclusion/exclusion criteria: median 60 (4-120) months. No patient without post-LT UC had rPSC: 0 of 20 vs. 7 of 26 with post-LT UC (P = 0.027). The multivariate logistic regression analysis showed that maintenance steroids for UC (>3 months) post-LT was the only risk factor significantly associated with rPSC (P = 0.025). In conclusion, the presence of UC post-LT, and the need for maintenance steroids post-LT, which is an independent factor, are associated with rPSC. These findings could help elucidate a possible mechanism of PSC pathogenesis. Liver Transpl, 2007. © 2007 AASLD.
Meta-analysis of risk for relapse to substance use after transplantation of the liver or other solid organs
Authors: Dew Mary Amanda , DiMartini Andrea F. , Steel Jennifer , De Vito Dabbs Annette , Myaskovsky Larissa , Unruh Mark , Greenhouse Joel
Published: January 2008

For patients receiving liver or other organ transplants for diseases associated with substance use, risk for relapse posttransplantation is a prominent clinical concern. However, there is little consensus regarding either the prevalence or risk factors for relapse to alcohol or illicit drug use in these patients. Moreover, the evidence is inconsistent as to whether patients with pretransplantation substance use histories show poorer posttransplantation medical adherence. We conducted a meta-analysis of studies published between 1983 and 2005 to estimate relapse rates, rates of nonadherence to the medical regimen, and the association of potential risk factors with these rates. The analysis included 54 studies (50 liver, 3 kidney, and 1 heart). Average alcohol relapse rates (examined only in liver studies) were 5.6 cases per 100 patients per year (PPY) for relapse to any alcohol use and 2.5 cases per 100 PPY for relapse with heavy alcohol use. Illicit drug relapse averaged 3.7 cases per 100 PPY, with a significantly lower rate in liver vs. other recipients (1.9 vs. 6.1 cases). Average rates in other areas (tobacco use, immunosuppressant and clinic appointment nonadherence) were 2 to 10 cases per 100 PPY. Risk factors could be examined only for relapse to any alcohol use. Demographics and most pretransplantation characteristics showed little correlation with relapse. Poorer social support, family alcohol history, and pretransplantation abstinence of ≤6 months showed small but significant associations with relapse (r = 0.17-0.21). Future research should focus on improving the prediction of risk for substance use relapse, and on testing interventions to promote continued abstinence posttransplantation. Liver Transpl 14:159–172. 2008. © 2008 AASLD.
Eighteen years of liver transplantation experience in patients with advanced Budd-Chiari syndrome
Authors: Ulrich Frank , Pratschke Johann , Neumann Ulf , Pascher Andreas , Puhl Gero , Fellmer Peter , Weiss Sascha , Jonas Sven , Neuhaus Peter
Published: January 2008

The long-term results of liver transplantation for Budd-Chiari syndrome (BCS) and timely indication for the procedure are still under debate. Innovations in interventional therapy and better understanding of underlying diseases have improved therapy strategies. The aim of this study was the analysis of patient and disease characteristics, outcome, and specific complications. Between September 1988 and December 2006 we performed 42 orthotopic liver transplantations (OLTs) in 39 patients with BCS. A total of 29 (74%) women and 10 men (26%) had a median age of 35 years; the median follow-up period was 96 months. Etiologically, 27 patients had a preoperative diagnosis of hematologic disease, including myeloproliferative disorders (MPD), followed by factor V Leiden mutation and antiphospholipid syndrome. The actuarial 5-year and 10-year survival rates were 89.4% and 83.5%, respectively, compared to 80.7% and 71.4%, respectively, for other indications (n = 1742). Retransplantation was necessary in 3 patients (7.1%) with portal vein thrombosis or recurrent BCS. Although the number of bleeding events was similar, incidence of vascular complications was significantly higher in patients with BCS. Thrombosis of the portal vein was observed in 4.8% versus 0.8% of the patients, whereas liver veins were affected in 7.1% versus 0.2%. Our data shows that severe acute or chronic forms of BCS with liver failure can be successfully treated by OLT. Despite higher rates of vascular complications, patient and graft survival are similar or even better compared to other indication groups. In conclusion, patients with reversible hepatic damage should be treated by combined strategies, including medical therapy and surgical or interventional shunting. Liver Transpl 14:144–150, 2008. © 2008 AASLD.
Polyarteritis nodosa, presenting as life-threatening gastrointestinal hemorrhage in a liver transplant recipient
Authors: Cooper Sheldon C. , Olliff Simon P. , McCafferty Ian , Wigmore Stephen J. , Mirza Darius F.
Published: January 2008

This unique case reports the first recorded episode in the medical literature of vasculitis post-liver transplantation, presenting as life-threatening gastrointestinal hemorrhage. A 52-year-old Caucasian woman underwent orthotopic liver transplantation (OLT) for autoimmune cirrhosis complicated by hepatoma and portal vein thrombosis. Late hepatic artery thrombosis led to a second liver graft. Following recovery from an episode of acute rejection, the patient presented with large volume hematemesis, melena, and hemochezia (passage of fresh blood from the rectum). Following upper and lower gastrointestinal endoscopy and surgery, angiography illustrated the presence of polyarteritis nodosa (PAN), which was successfully treated with high-dose steroid therapy. Gastrointestinal hemorrhage is an unusual presentation of vasculitis, especially PAN. The occurrence of this phenomenon post-OLT, in the presence of immunosuppression is previously unreported. Liver Transpl 14:151–154, 2008. © 2008 AASLD.
Frequency and predictors of de novo hepatocellular carcinoma in patients awaiting orthotopic liver transplantation during the model for end-stage liver disease era
Authors: Brady Carla W. , Smith Alastair D. , Stechuchak Karen M. , Coffman Cynthia J. , Tuttle-Newhall Janet E. , Provenzale Dawn , Muir Andrew J.
Published: January 2008

In the current system of allocation, patients awaiting orthotopic liver transplantation (OLT) remain at risk of developing de novo hepatocellular carcinoma (HCC) and removal from the waiting list. Using the United Network for Organ Sharing database, we calculated the rate and identified predictors of de novo HCC in patients listed for OLT between February 2002 and December 2004. Among 8566 patients, 1167 (13.6%) developed de novo HCC. Predictors of increased odds of de novo HCC were older age, male gender, Asian race, other race, hepatitis C, and hepatitis B. A sensitivity analysis of 2067 patients waiting at least 6 months found that 16.2% developed de novo HCC. Older age [odds ratio (OR) 1.05; 95% confidence interval (CI) 1.03, 1.07], male gender (OR 2.01; 95% CI 1.49, 2.71), Asian race (OR 2.39; 95% CI 1.20, 4.76), other race (OR 1.94; 95% CI 1.40, 2.68), hepatitis C (OR 2.36; 95% CI 1.76, 3.16), and hepatitis B (OR 1.96; 95% CI 1.19, 3.23) remained predictors of increased odds of de novo HCC, and alcoholic liver disease (OR 1.40; 95% CI 1.06, 1.86) emerged as a predictor of increased odds of de novo HCC. A significant proportion of patients listed for OLT develop de novo HCC. Identifying predictors of HCC in these patients may facilitate timely HCC screening and diagnosis. Liver Transpl 14:228–234, 2008. © 2008 AASLD.
The effect of liver transplantation on autonomic dysfunction in patients with end-stage liver disease
Authors: Carey Elizabeth J. , Gautam Manjushree , Ingall Timothy , Douglas David D.
Published: January 2008

Autonomic dysfunction is a recognized complication of end-stage liver disease (ESLD), but there is little information on how liver transplantation (LT) affects this problem. We sought to prospectively evaluate autonomic function in patients with ESLD before and after LT. Autonomic reflex screen (ARS) was performed on 30 patients with ESLD prior to transplantation. A 10-point composite autonomic score (CAS) was calculated from these data. ARS was repeated after LT, and these scores were compared with the pre-LT ARS. Thirty patients (25 male, 5 female) with cirrhosis that were listed for LT were enrolled in the study and underwent ARS prior to LT. The average age was 55.4 ± 9.1 years. Indications for LT included hepatitis C virus (14), cryptogenic cirrhosis (5), alcoholic cirrhosis (4), and other (7). The mean native Model for End-Stage Liver Disease (MELD) score at ARS was 17.0 ± 5.0. Prior to LT, 86.7% of patients had evidence of autonomic dysfunction. Mean CAS was 2.7 ± 2.2. Sudomotor function was disturbed in 66%, parasympathetic function was disturbed in 57%, and adrenergic function was disturbed in 37%. There was no relationship between pre-LT CAS and age, gender, diabetes, etiology of liver disease, or MELD score. Twenty-one patients (17 male, 4 female) had repeat ARS a mean of 9 ± 6.2 months after LT. The mean native MELD score at the time of ARS testing was 18.1 ± 4.3. Mean pre-LT CAS in this group was 3.0 ± 2.4. Pretransplant CAS was not related to age, gender, diabetes, or MELD score. Autonomic dysfunction improved after LT (CAS pre-LT, 3.0, versus CAS post-LT, 1.9,
P
= 0.02). There was no relationship between post-LT CAS and age, gender, diabetes, etiology of liver disease, immunosuppression, or type of transplant. In conclusion, autonomic dysfunction is common in patients with ESLD, with over 86% having abnormal testing. Sixty-three percent of patients with cirrhosis with autonomic dysfunction show improvement after LT. Liver Transpl 14:235–239, 2008. © 2008 AASLD.
Hepatic parenchymal changes and histologic eosinophilia as predictors of subsequent acute liver allograft rejection
Authors: Demirhan Beyhan , Bilezikçi Banu , Haberal Nihan A. , Sevmiş Şinasi , Arat Zübeyde , Haberal Mehmet
Published: January 2008

During the first episode of acute cellular rejection (ACR) after liver transplantation, centrilobular changes in liver biopsy specimens may be possible indicators of subsequent episodes of ACR, early chronic rejection, or acute graft loss. The purpose of this study was to identify differences between the histopathological findings in liver biopsy specimens obtained during the first rejection episode in patients who subsequently developed further episodes of ACR and those who did not. The histopathological findings in 22 patients who had a single episode of acute rejection (group 1) were compared with those in 23 patients who had multiple episodes of acute rejection (group 2). Only the first liver biopsy samples of the latter group were taken into consideration. We assessed the predictive value of centrilobular necrosis, central vein endothelialitis, pericentral inflammation, hepatocellular ballooning, cholestasis, hepatocellular apoptosis, lobular inflammation, the degree of portal eosinophilia, and characteristic portal tract features in poor responders to antirejection treatment. The time to the first episode of ACR and the rejection activity index were similar in patients in both groups. Hepatocellular apoptosis, hepatocellular ballooning, and central vein endothelialitis were common features of both groups. The incidences of pericentral inflammation, centrilobular necrosis, and portal eosinophilia were significantly higher in patients in group 2 than in those in group 1 (P < 0.05). Patients with pericentral inflammation, centrilobular necrosis, and marked portal eosinophilia during an initial episode of acute rejection may be more likely to develop subsequent episodes of ACR. Liver Transpl 14:214–219, 2008. © 2008 AASLD.
Valganciclovir as preemptive therapy for cytomegalovirus in cytomegalovirus-seronegative liver transplant recipients of cytomegalovirus-seropositive donor allografts
Authors: Singh Nina , Wannstedt Cheryl , Keyes Lois , Mayher Debra , Tickerhoof Lisa , Akoad Mohamed , Wagener Marilyn M. , Cacciarelli Thomas V.
Published: January 2008

The efficacy of valganciclovir as preemptive therapy for the prevention of cytomegalovirus (CMV) disease and its impact on indirect sequelae of CMV were assessed in recipient-negative/donor-positive (R−/D+) liver transplant recipients. Of 187 consecutive liver transplant recipients at our institution since July 2001, 36 (19.2%) belonged to the R−/D+ group. Surveillance tests for CMV were performed on all patients at weeks 2, 4, 6, 8, 10,12, and 16. In all, 27 patients with asymptomatic viremia received preemptive therapy with valganciclovir. At a total follow-up of 62.8 patient years (median: 19 months, range: 3 months to 5.6 years), no episodes of CMV disease were documented in these patients. The incidence of rejection, retransplantation, and bacterial or fungal infections and the probability of survival did not differ for R−/D+ patients and all non-R−/D+ patients treated preemptively with valganciclovir (P > 0.20 for all variables). Thus, preemptive therapy with valganciclovir in R−/D+ patients was not associated with CMV disease during the period of surveillance monitoring or at anytime thereafter (late-onset CMV disease). The indirect outcomes with the use of valganciclovir in R−/D+ patients were comparable to the outcomes of other subgroups of liver transplant recipients receiving preemptive therapy. Liver Transpl 14:240–244, 2008. © 2008 AASLD.