bluuebunny/crossref_metadata_2025 huggingface dataset:
Permeation and separation characteristics of acetic acid/water mixtures through poly(vinyl alcohol‐g‐itaconic acid) membranes by pervaporation, evapomeation, and temperature‐difference evapomeation
Authors: Işıklan Nuran , Şanlı Oya
Published: June 2004

In this study, itaconic acid (IA) was grafted onto poly(vinyl alcohol) (PVA) with cerium(IV) ammonium nitrate as an initiator at 45°C. The grafted PVA was characterized with Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and differential scanning calorimetry. IA‐grafted PVA membranes were prepared with a casting method, and the permeation and separation characteristics of acetic acid/water mixtures were investigated with pervaporation (PV), evapomeation (EV) and temperature‐difference evapomeation (TDEV) methods. The effects of the feed composition, operating temperature, and temperature of the membrane surroundings on the permeation rate and separation factor for the acetic acid/water mixtures were studied. The permeation rates in EV were lower than those in PV, whereas the separation factors were higher. With the TDEV method, the permeation rates decreased and the separation factors increased as the temperature of the membrane surroundings decreased. The prepared membranes were also tested in PV, EV, and TDEV to separate the various compositions of the acetic acid/water mixtures (20–90 wt % acetic acid) at 40°C. The highest separation factor, 686, was obtained in TDEV with a 90 wt % acetic acid concentration in the feed. The activation energies of permeation in PV and EV were calculated to be 8.5 and 10.2 kcal/mol, respectively, for a 20 wt % acetic acid solution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2322–2333, 2004
The fractal and scaling analysis of chemical reactions
Authors: Kozlov G. V. , Shustov G. B. , Zaikov G. E.
Published: June 2004

It is shown that the geometrical factor controlling a thermooxidative degradation course is effective spectral dimension d or factor β. In turn, parameters d and β are a function of a polymer melt structure characterized by its fractal dimension Δf. The applicability of this or that scaling relationship allows the evaluation of general features of chemical reactions in the thermooxidative degradation process. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2343–2347, 2004
Deacetylation of β‐chitin. II. Factorial experimental design
Authors: Chen Cheng‐Ho , Wang Fang‐Yu , Ou Zu‐Pei
Published: June 2004

A 23‐factorial experimental design has been used to study the main, two‐factor‐interaction, and three‐factor‐interaction effects of the NaOH concentration (X1), deacetylation time (X2), and deacetylation temperature (X3) on the degree of deacetylation (DD) of deacetylated products prepared from β‐chitin. Because the DD values of deacetylated products increase as X1, X2, or X3 increases, the main, two‐factor‐interaction, and three‐factor‐interaction effects for these three deacetylation conditions are positive. The sequence of the main effects on the DD values of deacetylated products is X3 < X2 < X1. The sequence of the two‐factor‐interaction effects on the DD values of deacetylated products is X2 versus X3 < X1 versus X3 < X1 versus X2. The prediction equation is Ŷ = 42.4 + 13.9X1 + 9.4X2 + 8.4X3 + 5.8X1X2 + 4.9X1X3 + 3.7X2X3 + 2.6X1X2X3 (where Ŷ is the predicted response) © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2423–2428, 2004
Deacetylation of β‐chitin. I. Influence of the deacetylation conditions
Authors: Chen Cheng‐Ho , Wang Fang‐Yu , Ou Zu‐Pei
Published: June 2004

The influences of the deacetylation temperature, deacetylation time, and NaOH concentration on the degree of deacetylation (DD) of deacetylated products prepared from β‐chitin are discussed. The DD values of deacetylated products are related to the ratio of the signal intensities of methyl on acetyl groups and the first anomeric carbon, which are obtained from 13C‐NMR spectra. The results show that the DD values of deacetylated product increase as the NaOH concentration, deacetylation time, or deacetylation temperature increases. The thermal properties, chemical structures, and crystalline characteristic of deacetylated products are significantly related to their DD values. Differential scanning calorimetry shows that the peak temperature is slightly increased as the DD values of deacetylated products of β‐chitin increase. Thermogravimetric analysis shows that the thermal degradation onset temperature of deacetylated products decreases as the DD values increase. Fourier transform infrared spectra show that the intensity of a specific absorption peak of NH2 in deacetylated products significantly increases as DD increases. X‐ray diffraction patterns of deacetylated products with DD values of 17.5 and 44.7% have three significant diffraction peaks. However, there are only two diffraction peaks found in products with higher DD values of 76.5 and 94.7%. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2416–2422, 2004
Synthesis and evaluation of high‐performance ethylene–propylene–diene terpolymer/organoclay nanoscale composites
Authors: Acharya H. , Pramanik M. , Srivastava S. K. , Bhowmick A. K.
Published: June 2004

The main objective of this study was to synthesize and characterize the properties of ethylene–propylene–diene terpolymer (EPDM)/clay nanocomposites. Pristine clay, sodium montmorillonite (Na+–MMT), was intercalated with hexadecyl ammonium ion to form modified organoclay (16Me–MMT) and the effect of intercalation toward the change in interlayer spacing of the silicate layers was studied by X‐ray diffraction, which showed that the increase in interlayer spacing in Na+–MMT by 0.61 nm is attributed to the intercalation of hexadecyl ammonium ion within the clay layers. In the case of EPDM/16Me–MMT nanocomposites, the basal reflection peak was shifted toward a higher angle. However, gallery height remained more or less the same for different EPDM nanocomposites with organoclay content up to 8 wt %. The nanostructure of EPDM/clay composites was characterized by transmission electron microscopy, which established the coexistence of intercalated and exfoliated clay layers with an average layer thickness in the nanometer range within the EPDM matrix. The significant improvement in thermal stability and mechanical properties reflects the high‐performance nanocomposite formation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2429–2436, 2004
Structure and properties of AlSi/polyester coating
Authors: Öksüz Mustafa , Yıldırım Hüseyin
Published: June 2004

Powder coatings, which are formed by plasma spray technique, are being used in industrial applications. Resistance of plastics and their based composite materials to chemicals, solvents, atmospheric conditions, and high impact strength even at low service temperature increases the importance of plastic and plastic based coating applications. In this study, aluminum silicon based polyester (AlSi/polyester) coating was applied by plasma spraying technique with and without intermediate bond layer coat (NiAl). The effect of coating thickness, intermediate bond layer coat, and plasma spraying parameters on bond strength of coating were studied experimentally. The bond strengths of the coatings were determined according to the ASTM C‐633–79. Microstructures of the coating were examined by optic microscopy and scanning electron microscopy (SEM), respectively. Obtained results indicated that plasma spraying current rate, coating thickness, and spraying distance were important factors on bond strength of coating. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2437–2444, 2004
Use of laser spallation to measure the adhesion of optical fiber coatings
Authors: Logunov Stephan , Kouzmina Inna , Winningham Michael , Fewkes Edward
Published: June 2004

The correlation between chemical effects of some typical optical fiber coating formulations and adhesion to glass was studied by the use of laser spallation. The technique was able to show verifiable differences between dissimilar materials and demonstrated a good correlation to adhesion values determined by mechanical peel testing, and to pullout values measured on coated optical fiber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2459–2468, 2004
Interface and mechanical properties of poly(methyl methacrylate)–fiber composites
Authors: Xie Tingxiu , Yang Guisheng
Published: June 2004

Long‐fiber pellets were made by an in situ pultrusion process. Fiber‐reinforced composites were prepared by an injection‐molding process and an extrusion/injection‐molding method with pellets, respectively. SEM observations showed that the strong interface was maintained during the injection process for low shearing forces, although polymer adhesion to the fiber surface was completely delaminated in the process of extrusion/injection molding for very high shearing forces. Enhanced adhesion of composites promoted substantial improvement of mechanical properties compared to those with poor adhesion. However, the enhanced adhesion between the fiber and the matrix also sacrificed the impact resistance properties. Longer fibers substantially enhanced the properties of composites. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2478–2483, 2004
Synthesis and characterization of polybutadiene with monotitanocene/methylaluminoxane catalyst
Authors: Zhu Fangming , Huang Dongdong , Lin Shangan
Published: June 2004

Butadiene was polymerized using a monotitanocene complex of η5‐pentamethylcyclopentadienyltribenzyloxy titanium [Cp*Ti(OBz)3] in the presence of four types of modified methylaluminoxanes (mMAO), which contained different amounts of residual trimethylaluminum (TMA). The titanium oxidation states in Cp*Ti(OBz)3/mMAO and Cp*Ti(OBz)3/mMAO/triisobutylaluminum (TIBA) catalytic systems were determined by redox titration method. The effects of various oxidation states of titanium active species on butadiene polymerization were investigated. It was found that Ti(III) active species is more effective for preparing polybutadiene with high molecular weight. The addition of TIBA to the Cp*Ti(OBz)3/mMAO system could reduce a greater number of Ti(IV) complexes to Ti(III) species and lead to significant increases of polymerization activity and molecular weight of polymer, whereas the polybutadiene microstructure was only slightly changed. On the basis of microstructure and property characterization by FTIR, 13C‐NMR, DSC, and WAXD, all resultant polymers were proved to be amorphous polybutadiene with mixed 1,2; cis‐1,4; and trans‐1,4 structures. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2494–2500, 2004
Synthesis and Antibacterial Evaluation of 1β‐Methyl‐2‐(5‐substituted heterocyclic carbamoyl)pyrrolidin‐3‐ylthio)carbapenem Derivatives
Authors: Lee Joo‐Shin , Choa Jung‐Hyuck , Cho Heeyeong , Oh Chang‐Hyun
Published: June 2004

>The synthesis of a new series of 1β‐methylcarbapenems having a substituted heterocyclic carbamoyl pyrrolidine moiety is described. Their in vitro antibacterial activity against both gram‐positive and gram‐negative bacteria was tested, and the effect of heterocyclic substituents on the pyrrolidine was investigated. One particular compound (IIId) having a substituted oxadiazole moiety showed the most potent antibacterial activity.
Membrane‐aerated microbioreactor for high‐throughput bioprocessing
Authors: Zanzotto Andrea , Szita Nicolas , Boccazzi Paolo , Lessard Philip , Sinskey Anthony J. , Jensen Klavs F.
Published: June 2004

A microbioreactor with a volume of microliters is fabricated out of poly(dimethylsiloxane) (PDMS) and glass. Aeration of microbial cultures is through a gas‐permeable PDMS membrane. Sensors are integrated for on‐line measurement of optical density (OD), dissolved oxygen (DO), and pH. All three parameter measurements are based on optical methods. Optical density is monitored via transmittance measurements through the well of the microbioreactor while dissolved oxygen and pH are measured using fluorescence lifetime‐based sensors incorporated into the body of the microbioreactor. Bacterial fermentations carried out in the microbioreactor under well‐defined conditions are compared to results obtained in a 500‐mL bench‐scale bioreactor. It is shown that the behavior of the bacteria in the microbioreactor is similar to that in the larger bioreactor. This similarity includes growth kinetics, dissolved oxygen profile within the vessel over time, pH profile over time, final number of cells, and cell morphology. Results from off‐line analysis of the medium to examine organic acid production and substrate utilization are presented. By changing the gaseous environmental conditions, it is demonstrated that oxygen levels within the microbioreactor can be manipulated. Furthermore, it is demonstrated that the sensitivity and reproducibility of the microbioreactor system are such that statistically significant differences in the time evolution of the OD, DO, and pH can be used to distinguish between different physiological states. Finally, modeling of the transient oxygen transfer within the microbioreactor based on observed and predicted growth kinetics is used to quantitatively characterize oxygen depletion in the system. © 2004 Wiley Periodicals, Inc.
Toward construction of a self‐sustained clock‐like expression system based on the mammalian circadian clock
Authors: Chilov Dmitri , Fussenegger Martin
Published: June 2004

Despite recent advances in circadian biology, detailed understanding of how a biological pacemaker system is assembled, maintained, and regulated continues to be a significant challenge. We have assembled and characterized a first‐generation, regulatable, self‐sustained clock‐like expression system based on key components of the mammalian circadian clock. The molecular setup of the clock‐like oscillator was reduced to the core set of positive and negative elements common to all known circadian pacemakers. Sophisticated tetracycline‐responsive multi‐cistronic expression integrated with forefront lentiviral transduction tools enabled autoregulated reporter transgene expression in a human cell line. We characterized transgene expression kinetics of an artificial oscillator and showed that its expression profiles could be modulated by a serum shock and administration of regulating tetracycline antibiotics. Design of a generic mammalian clock‐like expression system will offer novel opportunities to study circadian biology and may provide a unique tool for rhythmic expression of desired transgenes fostering advances in biopharmaceutical manufacturing, gene therapy, and tissue engineering. © 2004 Wiley Periodicals, Inc.
Eukaryoten ohne Mitochondrien — Fakt oder Illusion?
Authors: Hachtel Wolfgang
Published: June 2004

Die Mitochondrien der Eukaryoten haben sich nach allgemeiner Auffassung aus ehemals freilebenden Bakterien entwickelt, die zunächst als Endosymbionten in die Zellen urtümlicher, einzelliger Eukaryoten aufgenommen worden waren. Dass es auch heute noch ursprüngliche Protozoen gibt, die keine Mitochondrien besitzen, galt lange als unstrittig. Sie werden als Archaezoa zusammengefasst. Diese Organismen könnten als rezente Belege einer extrem frühen Phase der Eukaryoten‐Evolution vor dem endosymbiontischen Erwerb von Mitochondrien gelten. Diese Ansicht gerät aber immer mehr ins Wanken, denn die Beweise mehren sich, dass etliche Archaezoen doch erst sekundär frei von Mitochondrien sind.
Wirkstoffe mit Janusgesicht: Auxin‐Herbizide
Authors: Grossmann Klaus , Hansen Hauke
Published: June 2004

Mit ihrer Fähigkeit, insbesondere dikotyle Unkräuter in Getreidearten zu bekämpfen, gehören Auxin‐Herbizide zu den erfolgreichsten Wirkstoffen im Pflanzenbau. Erst in jüngster Zeit jedoch konnten Fortschritte in der Aufklärung ihres Wirkungsmechanismus erzielt werden. Der Schlüssel dazu war die Entdeckung einer neuen Variante des Zusammenspiels der Phytohormone. Nach der Erkennung des Auxin‐Signals kommt dabei der Induktion der 1‐Aminocyclopropan‐1‐carbonsäure (ACC)‐Synthase in der Biosynthese des Ethylens die entscheidende Rolle zu. Bei dikotylen Unkräutern löst die verstärkte Ethylenbildung Wachstumsveränderungen aus und stimuliert darüber hinaus die Synthese der Abscisinsäure. Die Folge ist ein Schluss der Stomata, Hemmung der CO2‐Assimilation, verstärkte Bildung von reaktiven Sauerstoffspezies, Blattseneszenz, Gewebeschädigung und schließlich Zelltod. Im Unterschied dazu kommt es im Gewebe empfindlicher Schadgräser zu einer Anhäufung von phytotoxischem Cyanid, das als Stoffwechselnebenprodukt der stimulierten Ethylenbiosynthese gebildet wird. All dies sind Reaktionen, die im Prinzip auch an der Regulation von normalen pflanzlichen Entwicklungsprozessen und Stressvorgängen beteiligt sein können.
Vom Sinn der Sinnlichkeit: Zur Neurobiologie der Musik
Authors: Spitzer Manfred
Published: June 2004

Musik ist durch die Physik schwingender Körper und die Physiologie des Gehirns bestimmt. Um diese These zu untermauern, werden zwei neurobiologisch entfernt liegende Aspekte des Musikerlebens diskutiert — die Frequenzzerlegung am Beginn der Hörwahrnehmung und die emotionalen Prozesse an deren Ende. Meist wird mit Saiten und schwingenden Luftsäulen musiziert; also mit „Objekten„, deren Obertöne ganzzahlige Vielfache der Grundfrequenz sind. Konsonanz und Dissonanz lassen sich durch die Anzahl der innerhalb der kritischen Bandbreite — einer Eigenschaft des Hörsystems — liegenden Obertöne berechnen. Die emotionalen Wirkungen von Musik sind Ausdruck der Aktivierung des gehirneigenen dopaminergen Belohnungssystems sowie der Deaktivierung der Amygdalae, die bekanntermaßen konditionierte Angsterlebnisse vermitteln. Dies legt nahe, dass Musik, wenn sie auch nicht für das Überleben der Art Mensch unbedingt notwendig ist, doch einen Beitrag zu unserem geistigen und körperlichen Wohlbefinden leisten kann.
Blutsauger in der Forschung: Hirudo medicinalis
Authors: Jauker Fritz , Clauss Wolfgang
Published: June 2004

Das Epithel des Blutegels ist reich an Ionenkanälen und ‐pumpen und eignet sich in besonderer Weise für die Erforschung des molekularen Aufbaus und der Wirkungsweise des epithelialen Natriumkanals, ENaC. Dieser spielt beim Menschen eine große Rolle bei der Regulation des Blutdrucks, aber auch bei erblichen Formen des Bluthochdrucks. Die Proteine dieses Kanals setzen sich aus phylogenetisch sehr alten und hochgradig konservierten Sequenzen zusammen. Es ist sogar möglich, den genetischen Code für den ENaC in der Oocyte des Krallenfroschs übersetzen und assemblieren zu lassen, wo er in die Eizellmembran eingebaut wird und seine osmotische Arbeit aufnimmt. Auf diese Weise können wir die Funktion des Ionenkanals und die Bedeutung einzelner Bauelemente des Moleküls untersuchen
Zwischen Perfektion und Katastrophe: Das Gehirn
Authors: Perl Sabine , Weimer Verena , Gassen Hans Günter
Published: June 2004

Das Gehirn ist wieder in den Mittelpunkt des allgemeinen und des wissenschaftlichen Interesses gerückt. Besonders die nichtinvasiven, bildgebenden Verfahren und die Neurogenetik werden unser Wissen über Gehirnfunktionen weiterbringen. Diese Erkenntnisse sind primär wichtig für die kausale Behandlung von Alzheimer, Parkinson und Schlaganfall. Bisher ist die energetische Versorgung des Gehirns besonders mit Glucose und Sauerstoff nicht genügend beachtet worden. Sauerstoff bringt die maximale Effizienz, seine Radikale aber verursachen Funktionsdefizite, mentale Störungen und Tod. Eine hirngängige Ernährung ist einer der Wege, um solche negativen Effekte zu verzögern oder gar zu vermeiden.
Filter zwischen Land und See: Darß‐Zingster Boddengewässer
Authors: Karsten Ulf , Schumann Rhena , Witte Kathrin
Published: June 2004

Die Darß‐Zingster Boddenkette stellt ein flaches, inneres Küstengewässer ohne Gezeiteneinfluss dar, wie es typisch für die südliche Ostsee ist. Dieses aquatische Ökosystem übt eine Filter‐ und Pufferwirkung auf die Ostsee aus. Im Gewässersystem existieren ausgeprägte horizontale chemische, physikalische und biologische Gradienten, von denen Salinität, Konzentration an Nährstoffen, sowie Verteilung und Aktivität aquatischer Primärproduzenten besonders auffällig sind.

Die Biologie und ökologische Bedeutung benthischer Mikrond Makroorganismen und des pelagischen Phytoplanktons für die gesamte aquatische Primärproduktion der Darß‐Zingster Boddenkette wird beschrieben. Aufgrund einer zunehmenden Eutrophierung ist es zu einer dramatischen Verschiebung in der Arten‐Zusammensetzung gekommen, insbesondere durch einen massiven Verlust an Makrophyten. Jedoch hat der Ausbau von Kläranlagen nach der Wende in Kombination mit einer Reduzierung landwirtschaftlicher Aktivitäten entlang der Darß‐Zingster‐Boddenkette zu einer Abnahme des Nährstoff‐Eintrages in das Gewässer geführt. Erste Anzeichen einer Erholung der Makrophytenbestände sind erkennbar.
Hugo Conwentz
Authors: Benedetter‐Herramhof Andrea
Published: June 2004

Naturkonformes, nachhaltiges Handeln und Bestimmungen, die den Schutz von natürlichen Ressourcen betreffen, reichen bis weit in die Vergangenheit zurück. Die Anfänge des modernen Naturschutzes dagegen — die Erhaltung der Natur um ihrer selbst willen — liegen im ausklingenden 19. Jahrhundert. In Deutschland war es der Botaniker Hugo Conwentz, der mit seinem Konzept der Naturdenkmalpflege den Grundstein für einen staatlich gelenkten Naturschutz legte.
Mimikry als Schutz vor messerscharfen Säbeln
Authors: Wendler Silke
Published: June 2004

In tropischen Regionen ist eine Ameisenart (Cardiocondyla obscurior) beheimatet, die je nach den vorherrschenden Umweltbedingungen gleichzeitig zwei verschiedene Männchentypen hervorbringt: friedliebende und angriffslustige. Um tödliche Auseinandersetzungen mit den aggressiven Rivalen zu vermeiden, imitiert der pazifistische Männchentyp den Duft weiblicher Tiere.
Determination of rhein, baicalin and berberine in traditional Chinese medicinal preparations by capillary electrophoresis with two‐marker technique
Authors: Huitao Liu , Ketai Wang , Xingguo Chen , Zhide Hu
Published: June 2004

A CZE method for the identiﬁcation and determination of three bioactive components, rhein, baicalin and berberine, was developed, with 10 mm borate at pH 9.20 as background electrolyte and direct UV detection at 254 nm. The two‐marker (glycyrrhizin acid and cefalexin) technique was used to improve the repeatability of analysis. When the migration indices were used, the repeatability was greatly enhanced compared with migration times. The apparent dissociation constents of rhein and baicalin were also obtained. This method has been successfully applied to the simultaneous analysis of the three components with the recoveries from 96.7% to 104.6%. Copyright © 2004 John Wiley & Sons, Ltd.
Simultaneous determination of estramustine phosphate and its four metabolites in human plasma by liquid chromatography–ionspray mass spectrometry
Authors: Breda M. , Basileo G. , James C. A.
Published: June 2004

A sensitive and selective method, using liquid chromatography–ionspray mass spectrometry, was developed and validated for the simultaneous determination of Estracyt (estramustine phosphate) and its four metabolites, estramustine, estromustine, estrone and estradiol, in human plasma. Deuterated internal standards were available for all analytes. The ﬁve compounds were extracted from plasma by protein precipitation with acetonitrile. The chromatographic separation was performed using a Zorbax SB C18, (150 × 4.6 mm i.d., 5 µm) reversed‐phase column under gradient conditions with a mobile phase containing 2 mm ammonium acetate buffer (pH 6.8) and acetonitrile. MS detection was by electrospray ionization with multiple reaction monitoring in the positive ion mode for estramustine phosphate, estromustine and estramustine, and in the negative ion mode for estrone and estradiol. The limit of quantitation was 10 ng/mL for estramustine phosphate, 3 ng/mL for estromustine, estramustine and estrone and 30 ng/mL for estradiol. Linearity was veriﬁed from these LLOQs up to about 4000 ng/mL for the parent drug and 2000 ng/mL for the metabolites. Inter‐day precision and accuracy values were all less than 15%. This assay was applied successfully to the routine analysis of human plasma samples collected in cancer patients administered estramustine phosphate intravenously. Copyright © 2003 John Wiley & Sons, Ltd.
Validated capillary electrophoretic method for the analysis of ivermectin in plasma after intragastric administration in pigs and horses
Authors: Kowalski Piotr , Bieniecki Michal , Olȩdzka Ilona , Lamparczyk Henryk
Published: June 2004

A capillary electrophoretic (CE) method has been developed for the determination of ivermectin (CAS 70288‐86‐7), a new generation drug with antiparasitic activity, in pig and horse plasma. The method was statistically validated for its linearity, accuracy, precision and selectivity. The linear range was from 1 to 30 ng mL−1 with correlation coefﬁcients greater than 0.999. The limit of detection was 0.3 ng mL−1, while the quantitative limit was 1 ng mL−1, using a 0.5 mL sample size. The validated procedure was used to determination of pharmacokinetic parameters of ivermectin after ingestion of 0.1 mg for pigs and 0.2 mg dose per kg body weight for horses, respectively. Studies were performed on a group of eight pigs and six horses. There were no signiﬁcant differences between pigs and horses in any of the estimated pharmacokinetic parameters. Copyright © 2003 John Wiley & Sons, Ltd.
HPLC microdetermination of ﬂurbiprofen enantiomers in plasma with a glycopeptide‐type chiral stationary phase column
Authors: Péhourcq F. , Matoga M. , Jarry C. , Bannwarth B.
Published: June 2004

A rapid and stereospeciﬁc HPLC micromethod to quantify ﬂurbiprofen enantiomers was developed. Both ﬂurbiprofen enantiomers and indomethacin, used as internal standard, were extracted with methylene chloride from 100 µL of acidiﬁed plasma. The resolution of the R‐ and S‐forms was performed on a bonded vancomycin chiral stationary phase (Chirobiotic V™) with 20% of tetrahydrofuran in ammonium nitrate (100 mm, pH 5) as mobile phase. Calibration curves were linear in the range 0.5–10 µg/mL for both enantiomers. A good accuracy (≤5%) was obtained for all quality controls, with intra‐day and inter‐day variation coefﬁcients equal or less than 7.7%. Recovery of both enantiomers was found in the range 77.4–86.3%. The lower limit of quantitation was 0.25 µg/mL for both enantiomers, without interference of endogenous components. This validated micromethod has been successfully applied for quantifying R‐ﬂurbiprofen and S‐ﬂurbiprofen in rat plasma. Copyright © 2003 John Wiley & Sons, Ltd.
Determination of the liver cytosolic proteins that bind to p‐hydroxyacetophenone
Authors: Negoro Munetaka , Wakabayashi Ichiro
Published: June 2004

The purpose of the present study was to determine the proteins that bind to acetophenones in the liver. Immobilized p‐hydroxyacetophenone (p‐HAP) was used as a ligand of afﬁnity chromatography. Analysis using sodium dodesyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) demonstrated that ﬁve polypeptides in the liver cytosolic fraction speciﬁcally bound to the p‐HAP matrix. These polypeptides were digested with Lys‐speciﬁc protease and used to generate peptide maps by reversed‐phase high‐performance liquid chromatography. Consequently, identiﬁcation from a data base of protein sequences revealed that the ﬁve polypeptides were glycogen phosphorylase, cytosolic aldehyde dehydrogenase, adenosine kinase, class I alcohol dehydrogenase and glutathione S‐transferase A2. In addition to p‐HAP, acetylsalicylic acid also displayed a prominent ability to elute these ﬁve enzymes from the p‐HAP afﬁnity column loaded with the cytosolic fraction of the liver. Thus, p‐HAP has afﬁnities to the above liver enzymes and is a useful ligand for analysis of them. Copyright © 2004 John Wiley & Sons, Ltd.
Attitudes toward Indigenous Australians: the role of empathy and guilt
Authors: Pedersen Anne , Beven Jaimie , Walker Iain , Griffiths Brian
Published: June 2004

Previous research in Perth, Western Australia, finds a disturbing amount of prejudice against Indigenous Australians. At the forefront of much prejudice research has been the distinction between old‐fashioned and modern prejudice. We constructed an Attitude Toward Indigenous Australians scale from items originating from qualitative data. We found that negative attitudes were predicted by collective guilt about past and present wrongs to Indigenous Australians (collective guilt directly linked to Indigenous issues, as well as collective guilt generally). Negative attitudes were also predicted by a lack of empathy for Indigenous Australians, and affective perspective taking generally. Socio‐demographics (e.g. a lack of education) predicted negative attitudes, which indicate the necessity of taking both social‐psychological and socio‐demographic factors into account when examining the nature of prejudice. A number of practical implications arise from these findings. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and Reactivity of the Monomeric Late‐Transition‐Metal Parent Amido Complex [Ir(Cp*)(PMe3)(Ph)(NH2)]
Authors: Rais Daniela , Bergman Robert G.
Published: June 2004

The late‐transition‐metal parent amido compound [Ir(Cp*)(PMe3)(Ph)(NH2)] (2) has been synthesized by deprotonation of the corresponding ammine complex [Ir(Cp*)(PMe3)(Ph)(NH3)][OTf] (6) with KN(SiMe3)2. An X‐ray structure determination has ascertained its monomeric nature. Proton‐transfer studies indicate that 2 can successfully deprotonate p‐nitrophenylacetonitrile, aniline, and phenol. Crystallographic analysis has revealed that the ion pair [Ir(Cp*)(PMe3)(Ph)(NH3)][OPh] (8) exists as a hydrogen‐bonded dimer in the solid state. Reactions of 2 with isocyanates and carbodiimides lead to overall insertion of the heterocumulenes into the NH bond of the Ir‐bonded amido group, demonstrating the ability of 2 to act as an efficient nucleophile. Intriguing reactivity is observed when amide 2 reacts with CO or 2,6‐dimethylphenyl isocyanide. η4‐Tetramethylfulvene complexes [Ir(η4‐C5Me4CH2)(PMe3)(Ph)(L)] (L=CO (15), CNC6H3‐2,6‐(CH3)2 (16)) are formed in solution through displacement of the amido group by the incoming ligand followed by deprotonation of a methyl group on the Cp* ring and liberation of ammonia. Conclusive evidence for the presence of the Ir‐bonded η4‐tetramethylfulvene moiety in the solid state has been provided by an X‐ray diffraction study of complex 16.
Stereoselective Synthesis of trans‐threo‐trans‐Oligopyrrolidines: Potential Agents for RNA Cleavage
Authors: Arndt Hans‐Dieter , Welz Rüdiger , Müller Sabine , Ziemer Burkhart , Koert Ulrich
Published: June 2004

The 2,5‐trans‐substituted oligopyrrolidines constitute a promising class of novel RNA‐binding agents as well as potential building blocks for artificial anion channels. A convergent synthesis of terpyrrolidine 1 and pyrrolidino‐THF‐pyrrolidine 2 is reported, relying upon convergent coupling of 2,5‐trans‐pyrrolidinecarboxaldehydes through bridging alkyne units under Felkin–Anh control and subsequent closure of the central ring. After complete deprotection, the free polyamine products were isolated in excellent yield and purity. Crystal structure analyses of a terpyrrolidine and a pyrrolidino‐THF‐pyrrolidine documented their helical privileged conformations. The compounds were then screened for RNA cleavage activity. Unlike the only weakly active simple polyamines, p‐nitrosulfonamide 33 was found to induce cleavage at mM concentrations under physiologically relevant conditions.
Effect of intramolecular interactions on circular dichroism of ortho‐substituted 1‐phenethylamines
Authors: Demyanovich V.M. , Shishkina I.N. , Zefirov N.S.
Published: June 2004

The synthesis of ortho‐substituted (S)‐1‐phenethylamines via ortho‐lithiation of its N,N‐dimethyl derivative followed by reactions with different reagents is described. Circular dichroism spectra of synthesized compounds were measured. It is shown that the observed short‐wave Cotton effects greatly depend on the existence of cyclic structure due to possible interactions such as hydrogen bond or electrostatic interaction. Chirality 16:486–492, 2004. © 2004 Wiley‐Liss, Inc.
Memory effect of diethylamine mobile phase additive on chiral separations on polysaccharide stationary phases
Authors: Stringham Rodger W. , Lynam Kenneth G. , Lord Barbara S.
Published: June 2004

The existence of a memory effect for amine additives on polysaccharide chiral stationary phases has often been suggested, but not clearly demonstrated. Demonstration of this effect is made difficult by the uncertainty as to which analytes benefit from use of amine additives and, typically, an unclear history of column use. In this work, analytes were selected for differences in their behavior with and without additives. Columns were used with no prior history. A persistent memory effect was demonstrated on a CHIRALPAK AD‐H column in hexane‐based mobile phases. This effect was short‐lived, with polar organic mobile phases. Memory was short‐lived on a CHIRALCEL OJ‐H column. Flushing with isopropanol was shown to remove most of the memory effect. Compounds expected to require amine additives on CHIRALCEL OD‐H column did not. Acid treatment of the AD‐H and OD‐H columns changed their performance, which was subsequently restored by the incorporation of amine. Chirality 16:493–498, 2004. © 2004 Wiley‐Liss, Inc.
Gleichgewichtsmodellierung bei der Trennung von Cobalt und Nickel durch Reaktivextraktion
Authors: Manski R. , Bart H.‐J.
Published: June 2004

No abstracts.
Intensivierung des Stofftransportes bei heterogen katalysierten Reaktionen durch Druckoszillation
Authors: Zirkwa I. , Grünewald M. , Agar D. W. , Wernke R.
Published: June 2004

No abstracts.
Prozessbeziehungen bei nichtnewtonschen Stoffen – Kritik des Metzner‐Otto‐Konzeptes
Authors: Pawlowski J.
Published: June 2004

No abstracts.
Quantitative hochauflösende Online‐NMR‐Spektroskopie im Reaktions‐ und Prozessmonitoring
Authors: Maiwald M. , Fischer H. H. , Hasse H.
Published: June 2004

No abstracts.
Erzeugung von Synthesegas durch trockenes Plasma‐Reforming
Authors: Behr A. , Oberreuther T. , Wolff C.
Published: June 2004

No abstracts.
Großtechnisches Konzept für die Erzeugung von Synthesegas durch trockenes Plasma‐Reforming
Authors: Behr A. , Oberreuther T. , Wolff C.
Published: June 2004

No abstracts.
Verbessertes Verfahren zur Salpetersäurehochkonzentrierung mit Magnesiumnitrat
Authors: Winterbauer H.
Published: June 2004

No abstracts.
Ein Sandwich zum Destillieren – Die Anstaupackung
Authors: Kashani N. , Siegert M. , Sirch T.
Published: June 2004

No abstracts.
Mikrowellenassistierte Reaktionsführung: Mikrowellenapparatur im Miniplant‐Maßstab mit Online‐Analytik
Authors: Bierbaum R. , Nüchter M. , Ondruschka B.
Published: June 2004

No abstracts.
Explosionstypen und ihre Zuordnung zu Rechtsvorschriften
Authors: Reimer B.
Published: June 2004

Schadensexplosionen werden durch einen spontanen und erheblichen Druckaufbau verursacht, der auf chemische Reaktionen oder physikalische Prozesse zurückzuführen ist. Explosionsfähige Reaktionssysteme können in der Gasphase, aber auch im festen oder flüssigen Zustand bzw. in Mischphasen auftreten. Für die sicherheitstechnische Charakterisierung derartiger Systeme stehen anerkannte Untersuchungsmethoden zur Verfügung. In der Stoff wandelnden Industrie sind solche physikalischen Explosionen von Bedeutung, bei denen der Druckaufbau durch einen spontanen Stoffübergang vom flüssigen in den gasförmigen Zustand hervorgerufen wird. Ausführliche Rechtsvorschriften, ergänzt durch technische Regeln, existieren bezüglich der Brennstoff/Luft‐Gemische, die unter atmosphärischen Bedingungen auftreten. Auch der Umgang mit explosionsgefährlichen Stoffen ist im Sprengstoffgesetz und den diesbezüglichen Verordnungen detailliert geregelt. Die anderen explosionsfähigen Reaktionssysteme fallen in den Geltungsbereich der Gefahrstoffverordnung, wenn eine kritische Mengenschwelle überschritten wird, in den der Störfallverordnung. Die konstruktiven Anforderungen, die Arbeitsmittel bezüglich des Explosionsschutzes zu erfüllen haben, sind in Verordnungen zum Geräte‐ und Produktsicherheitsgesetz geregelt.
Nutzung biogener Festbrennstoffe in Vergasungsanlagen
Authors: Osowski S. , Neumann J. , Fahlenkamp H.
Published: June 2004

Aufgrund der knapper werdenden fossilen Rohstoffe gewinnen Biomassen als regenerative Energiequellen zunehmend an Bedeutung. Daher ist es für die Umsetzung von Biomasseprojekten und den verstärkten Einsatz von Biomasseanlagen wesentlich, geeignete thermische Verfahren für den Biomasseeinsatz zu identifizieren. Vor diesem Hintergrund muss die Bewertung verschiedener Vergasungstechnologien hinsichtlich unterschiedlicher Randbedingungen und Einsatzstoffe erfolgen. Da die Zusammensetzung des Produktgases mit Art und Form des Brennstoffs sowie der Vergaserbauart variiert, wird im Folgenden die Eignung für die Biomassenvergasung in ausgesuchten Vergasungsreaktoren mit ihren Vor‐ und Nachteilen analysiert.
Auto‐reverse nuclear migration in bipolar mammalian cells on micropatterned surfaces
Authors: Szabó B. , Környei Zs. , Zách J. , Selmeczi D. , Csúcs G. , Czirók A. , Vicsek T.
Published: June 2004

A novel assay based on micropatterning and time‐lapse microscopy has been developed for the study of nuclear migration dynamics in cultured mammalian cells. When cultured on 10–20‐μm wide adhesive stripes, the motility of C6 glioma and primary mouse fibroblast cells is diminished. Nevertheless, nuclei perform an unexpected auto‐reverse motion: when a migrating nucleus approaches the leading edge, it decelerates, changes the direction of motion, and accelerates to move toward the other end of the elongated cell. During this process, cells show signs of polarization closely following the direction of nuclear movement. The observed nuclear movement requires a functioning microtubular system, as revealed by experiments disrupting the main cytoskeletal components with specific drugs. On the basis of our results, we argue that auto‐reverse nuclear migration is due to forces determined by the interplay of microtubule dynamics and the changing position of the microtubule organizing center as the nucleus reaches the leading edge. Our assay recapitulates specific features of nuclear migration (cell polarization, oscillatory nuclear movement), while it allows the systematic study of a large number of individual cells. In particular, our experiments yielded the first direct evidence of reversive nuclear motion in mammalian cells, induced by attachment constraints. Cell Motil. Cytoskeleton 59:38–49, 2004. © 2004 Wiley‐Liss, Inc.
Feasibility of breast‐conserving surgery for patients with breast carcinoma associated with nipple discharge
Authors: Cabioglu Neslihan , Krishnamurthy Savitri , Kuerer Henry M. , Hunt Kelly K. , Singletary S. Eva , Meric‐Bernstam Funda , Ross Merrick I. , Feig Barry W. , Ames Frederick C. , Babiera Gildy V.
Published: June 2004

BACKGROUND

Few studies in the literature address the surgical management of patients with breast carcinoma who present with associated nipple discharge. The purpose of the current study was to determine the feasibility of breast‐conserving surgery (BCS) for these patients.

METHODS

The medical records of patients who presented with pathologic nipple discharge and underwent diagnostic or curative surgery between January 1990 and December 2002 were retrospectively reviewed.

RESULTS

A total of 188 patients presented with nipple discharge during the study period. Of those, 47 had breast carcinoma. One patient had metachronous bilateral nipple discharge associated with malignant disease. Therefore, medical records associated with a total of 48 cases were reviewed. The median patient age was 52 years (range, 29–87 years), and the median follow‐up duration was 45 months (range, 6–109 months). Twenty‐nine patients had ductal carcinoma in situ (DCIS), 14 had Stage I disease, 3 had Stage II disease, and 2 had Stage III disease. Twenty‐four patients were ultimately treated with mastectomy. For 16 of these patients, mastectomy was required because extensive disease was found in reexcisional segmental mastectomy specimens. Among patients with Stage 0 or I disease, the incidence of occult nipple‐areola complex (NAC) involvement was 16% (3 of 19 patients). Twenty‐four patients were ultimately treated with BCS with (n = 13) or without (n = 11) adjuvant radiotherapy. Local disease recurrence was noted at 14, 28, and 40 months, respectively, in 3 patients who declined adjuvant radiotherapy after BCS for DCIS. Among patients treated with BCS, comedonecrosis, multifocality, and the absence of adjuvant radiotherapy were associated with decreased local recurrence–free survival (P = 0.0005, P = 0.045, and P = 0.013, respectively). However, disease‐free survival (mean ± standard error) was similar for patients who underwent mastectomy and patients who underwent BCS (90 ± 6 months; 95% confidence interval [CI], 78–101 months vs. 82 ± 6 months; 95% CI, 69–94 months; P = 0.528). One patient with Stage I disease died of distant metastases at 99 months.

CONCLUSIONS

Patients with breast carcinoma accompanied by nipple discharge presented primarily with early‐stage breast carcinoma associated with DCIS. Occult NAC involvement was not an uncommon finding in patients with early‐stage breast carcinoma. Nonetheless, BCS can be performed safely if negative margins are achieved and if appropriate adjuvant radiotherapy or systemic therapy is administered. Cancer 2004. © 2004 American Cancer Society.
Monoclonal gammopathy of undetermined significance and multiple myeloma are associated with an increased incidence of venothromboembolic disease
Authors: Srkalovic Gordan , Cameron Marte G. , Rybicki Lisa , Deitcher Steven R. , Kattke‐Marchant Kandice , Hussein Mohamad A.
Published: June 2004

BACKGROUND

Venous thromboembolic disease (VTD) is a recently recognized complication of thalidomide in combination therapy for patients with multiple myeloma (MM). The authors assessed the frequency of VTD and its risk factors in 612 consecutive patients with plasma cell dyscrasia (PCD) who were evaluated and followed from 1991 to 2001.

METHODS

In the current study, 404 patients were diagnosed with multiple myeloma (MM), 174 with monoclonal gammopathy of undetermined significance (MGUS), and 34 with other forms (excluding amyloidosis). Univariable correlates of VTD were assessed using Kaplan–Meier analysis and Cox proportional hazards analysis.

RESULTS

The authors identified several univariable correlates of VTD in patients with MGUS, including a family and medical history of VTD, immobility, low serum albumin level, and high leukocyte count. Patients with MGUS with immunoglobulin (Ig) G monoclonal immunoglobulin were found to be less prone to develop VTD. In patients with MM, a family and medical history of VTD and the presence of a hypercoagulable state were factors identified in univariable analysis to be associated with an increased risk of VTD. In patients with MM, for each unit increase in serum albumin, the risk of VTD was lower. The type of the treatment regimen did not appear to correlate with the development of VTD.

CONCLUSIONS

In the current study, the risk for thromboembolic diseases among patients with PCD was increased compared with the risk in the general population. Further studies are necessary to define the mechanisms involved. Cancer 2004. © 2004 American Cancer Society.
Risk assessment of patients with hematologic malignancies who develop fever accompanied by pulmonary infiltrates
Authors: Offidani Massimo , Corvatta Laura , Malerba Lara , Marconi Monica , Bichisecchi Elisabetta , Cecchini Sara , Manso Esther , Principi Tiziana , Gasparini Stefano , Leoni Pietro
Published: June 2004

BACKGROUND

The mortality rate associated with fever accompanied by pulmonary infiltrates after chemotherapy for hematologic malignancies remains higher than the corresponding rate associated with febrile neutropenia without pulmonary infiltrates. Nonetheless, few studies have focused on the factors that predict outcome for patients with lung infiltrates. The purpose of the current study was to construct a risk model for clinical use by assessing the factors that affect outcome for patients with fever and pulmonary infiltrates.

METHODS

A historical cohort of 110 patients with hematologic malignancies who developed fever and pulmonary infiltrates was examined. Using parameters for which data were available at the onset of lung infiltrates, univariate and multivariate analyses were performed to assess factors affecting outcome. After a value of one point was assigned to each significant variable, a prediction score was calculated for each patient; scores were used to generate a system for identifying patients with a low risk of death due to fever accompanied by pulmonary infiltrates.

RESULTS

The crude mortality rate associated with pulmonary infiltrates was 23%; factors associated with cure included a favorable change in white blood cell counts (odds ratio [OR], 5.6; 95% confidence interval [CI], 1.7–18.9; P = 0.001), C‐reactive protein levels < 10 mg/dL (OR, 4.6; 95% CI, 1.6–13.8; P = 0.001), and serum albumin levels ≥ 3 g/dL (OR, 3.2; 95% CI, 1.4–7.3; P = 0.004). Low‐risk patients (risk score, 2–3) and high‐risk patients (risk score, 0–1) had survival rates of 95% and 46%, respectively (P < 0.0001). The risk model had a specificity of 88% and a positive predictive value of 95%.

CONCLUSIONS

The risk model tested in the current study accurately predicted the survival of patients with hematologic malignancies who developed fever with pulmonary infiltrates. Once prospectively validated, the model could be used to select patients for trials involving novel diagnostic and therapeutic strategies. Cancer 2004. © 2004 American Cancer Society.
Glycosylation patterns are sexually dimorphic throughout development of the olfactory system in Manduca sexta
Authors: Gibson Nicholas J. , Hildebrand John G. , Tolbert Leslie P.
Published: June 2004

In the moth Manduca sexta, development of the adult olfactory system depends on complex interactions between olfactory receptor neurons in the antenna, antennal‐lobe neurons in the brain, and several classes of glial cells. As one approach to characterizing molecules that may play roles in these interactions, we used lectins to screen antennae and antennal lobes at different stages of adult development. We find that each of the major neural cell types has a distinct pattern of labeling by lectins. Effects of enzymatic and other treatments on lectin labeling lead us to conclude that the predominant lectin ligands are: glycosphingolipids and an O‐linked, fucose‐containing glycoprotein on axons of olfactory receptor neurons, O‐linked glycoproteins on antennal‐lobe neurons, and N‐linked glycoproteins on all classes of glial cells in the primary olfactory pathway. Wheat germ agglutinin labels all olfactory axons uniformly during much of development, but labeling becomes restricted to the pheromone‐responsive olfactory receptor neurons in the adult male. Succinylated WGA reveals differences in these axon classes earlier, as glomerului develop from protoglomeruli. The adult female displays a less pronounced difference in labeling of axons targeting ordinary and sexually dimorphic glomeruli. Differences in labeling of receptor axons targeted to ordinary and sexually dimorphic glomeruli may be correlated with differences in function or connectivity in different regions of the antennal lobe. J. Comp. Neurol. 476:1–18, 2004. © 2004 Wiley‐Liss, Inc.