bluuebunny/crossref_metadata_2025 huggingface dataset:
pH‐responsive semi‐interpenetrating networks hydrogels of poly(acrylic acid‐acrylamide‐methacrylate) and amylose. I. Synthesis and characterization
Authors: Li Shengfang , Yang Yajiang , Li Haibing , Yang Xiangliang , Xu Huibi
Published: September 2007

The semi‐interpenetrating networks gels of hydrophobically‐modified poly(acrylic acid‐acrylamide‐methacrylate) and amylose were prepared using 4,4′‐bis(methacryloylamino) azobenzene as a crosslinker. Investigation of mechanical strength of gels showed that the equilibrium elastic modulus G changed from 12.4 to 32.9 g/cm2 with increasing the contents of amylose in the case of low content of crosslinker. The swelling behavior of gels indicated that the aggregation of the hydrophobic groups of hydrogels could be destroyed by expanded amylose and the electrostatic repulsion between the charged COO− groups because of the ionization of the carboxylic groups in pH 7.4 buffer solutions. The hydrophobicity and flexibility of the side chain, the entanglement extent of the amylose, and the ionization of carboxyl groups in the gels greatly affected the swelling rates and swelling ratios. Investigations of swelling/deswelling periodically in pH 2.2 and 7.4 media indicated that the semi‐IPN gel was more pH‐sensitive than the nonsemi‐IPN gel. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Preparation and characterization of novel semi‐interpenetrating 2‐hydroxyethyl methacrylate‐g‐chitosan copolymeric microspheres for sustained release of indomethacin
Authors: Babu V. Ramesh , Sairam M. , Hosamani K. M. , Aminabhavi T. M.
Published: September 2007

A novel semi‐interpenetrating (semi‐IPN) graft copolymer of 2‐hydroxyethyl methacrylate (HEMA) with chitosan (CS) has been prepared in the form of microspheres, using water‐in‐oil (W/O) emulsion technique. Microspheres were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and X‐ray diffractometry (X‐RD) to confirm the crosslinking and polymorphism of indomethacin (IDM). The X‐RD and DSC techniques indicated a molecular‐level dispersion of IDM in the IPN matrix. Scanning electron micrographs (SEM) taken at the cross section of the microspheres have shown rough surfaces around the microspheres. The sustained release characteristics of the matrices for IDM, an anti‐inflammatory drug, were investigated in pH 7.4 media. Particle size and size distribution of the microspheres were studied by laser light diffraction particle size analyzer. The drug was released in a sustained manner for up to 12 h. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci, 2006
Chemical resistance, void contents, and morphological properties of Hildegardia fabric/polycarbonate‐toughened epoxy composites
Authors: Guduri B. R. , Rajulu A. V. , Luyt A. S.
Published: September 2007

A uniaxial natural fabric of Hildegardia populifolia was used as a reinforcement for a polycarbonate‐toughened epoxy. The Hildegardia fabric was treated with a 5% sodium hydroxide solution for 1 h. The fabric was spray‐coated with a 1% silane‐based coupling agent. The variation of the chemical resistance and void content with different fabric contents and fiber orientations was studied. The morphology of the fractured composites was investigated with scanning electron microscopy (SEM). SEM micrographs indicate that the bonding between the Hildegardia fabric and the matrix was enhanced partially by the alkali treatment. The alkali treatment in the presence of the silane coupling agent gave rise to matrix skin formation on the surface of the fibers, which indicated good bonding between the reinforcement and the matrix. Hildegardia/polycarbonate‐toughened epoxy composites were found to have reasonable chemical and water resistance. The liquid absorption increased when the fabric was treated with an alkali, when the coupling agent was used, and in the presence of water and aqueous solutions. The void content of the composites decreased with increasing fabric content. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Synthesis and pressure sensitive adhesive performance of poly (EHA‐co‐AA)/silicate nanocomposite used in transdermal drug delivery
Authors: Rana Pradeep K. , Sahoo Prafulla K.
Published: September 2007

The transdermal drug delivery (TDD) has got main advantage over the conventional oral delivery and maintaining the plasma drug level at a plateau over a long period of time. The phenomenon is taking place at the patch‐skin interface, in particular the adhesion of a polymeric nanoscale pressure sensitive adhesive (PNPSA) film loaded with drug. The major requirements of this PNPSA are they should stick firmly to a difficult substrate (skin) and they should be easily and cleanly removed from the substrate when desired. The PNPSA nanocomposite P(EHA‐co‐AA)/SS is prepared by the emulsion copolymerization of two acrylic monomers, 2‐ethyl hexylacrylate (EHA) and acrylic acid (AA) using a silicone additive like sodium silicate (SS). The TDD patch consists of a nanoscale silicone based polymeric adhesive i.e., P(EHA‐co‐AA)/SS and a drug Cloxacillin sodium an antibiotic. The prepared polymeric nanocomposites can carry drug and these bioactives are entrapped in the polymer matrix as particulates enmesh or bound to the particle surface by physical adsorption. The well characterized novel nanocomposites exhibited significant PSA performance in TDD system. In view of its medical application, the biodegradation study by activated sludge water indicated the nanocomposite to be environmentally friendly. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Nanoscale patterning in crosslinked methacrylate copolymer networks: An atomic force microscopy study
Authors: Ye Qiang , Spencer Paulette , Wang Yong
Published: September 2007

To understand the properties of materials, their phase structure must be established. It has been difficult in previous work to visualize the heterogeneous crosslinked structure of methacrylate‐based networks. In this work, nano‐sized phases with worm‐like features were detected in the surfaces of model crosslinked methacrylate copolymer containing hydrophobic/hydrophilic co‐monomers using tapping mode atomic force microscopy/phase imaging technique. The effects of different surface‐contact covers on the height and phase‐contrast images of model resin surfaces were also studied. Based on the experimental data, the identification of phase domains was proposed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Particle growth behavior of poly(methyl methacrylate) nanoparticles synthesized by the reversible addition fragmentation transfer living radical polymerization reaction
Authors: Kim Jusung , Kwak Juho , Kim Dukjoon
Published: September 2007

PMMA nanoparticles with highly mono‐dispersed size distribution were prepared using the RAFT living radical emulsion polymerization technique. A novel sur‐iniferter for the RAFT reaction, DTBA, was synthesized and its chemical structure was identified using several spectroscopic techniques. The relationship between the particle size and the molecular weight of the polymer was investigated measuring the rate of growth of each during formation of particles, and was well explained by the simple random flight molecular conformation model. The particle size increased up to a certain value with decreasing sur‐iniferter concentration and then leveled off, because the surface charge density of the growing particles was not high enough to stabilize the particles in aqueous medium above that value. The core‐shell type di‐block copolymer nanoparticles were also successfully prepared via RAFT reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Thermal, mechanical, and structural investigation of the effect of electron beam‐irradiation in Bayfol nuclear track detector
Authors: Nouh S. A. , Hegazy T. M. , el Hussieny H. M. , Chaaban Jinane K.
Published: September 2007

Samples from sheets of the polymeric material Bayfol have been exposed to electron beam in the dose range 10–100 kGy. The resultant effect of electron beam irradiation on the thermal properties of Bayfol has been investigated using thermogravimetric analysis. The onset temperature of decomposition T0 and activation energy of thermal decomposition Ea were calculated, results indicating that the Bayfol polymer decomposes in one main weight loss stage. Also, the electron irradiation in the dose range 40–100 kGy led to a more compact structure of Bayfol polymer, which resulted in an improvement in its thermal stability with an increase in activation energy of thermal decomposition. The variation of transition temperatures with electron dose has been determined using differential thermal analysis. The results indicate that the electron irradiation in the dose range 40–100 kGy causes crosslinking that destroys the crystalline structure depressing the melting temperature and this is most suitable for applications requiring the molding of this polymer at lower temperatures. In addition, the mechanical and structural properties of Bayfol samples were measured and the results revealed that the tensile strength, elongation at break, yield strength, and intrinsic viscosity were affected by the electron doses. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Closed‐form approximations to the error and complementary error functions and their applications in atmospheric science
Authors: Ren C. , MacKenzie A. R.
Published: August 2007

The error function, as well as related functions, occurs in theoretical aspects of many parts of atmospheric science. This note presents a closed‐form approximation for the error, complementary error, and scaled complementary error functions, with maximum relative errors within 0.8%. Unlike other approximate solutions, this single equation gives answers within the stated accuracy for real variable x ∈ [0∞). The approximation is very useful in solving atmospheric science problems by providing analytical solutions. Examples of the utility of the approximation are: the computation of cirrus cloud physics inside a general circulation model, the cumulative distribution functions of normal and log‐normal distributions, and the recurrence period for risk assessment. Copyright © 2007 Royal Meteorological Society
Anwendung verschiedener Injektionstechniken als Sicherungsmaßnahmen im Zuge der Baumaßnahme Nord‐Süd‐Stadtbahn Köln, Los Nord
Authors: Stelte Manuel
Published: September 2007

Für den Bau der Nord‐Süd‐Stadtbahn Köln waren im Los Nord aufgrund der schwierigen geologischen Verhältnisse Sicherungsmaßnahmen mittels Injektionstechnik für die anstehende Bebauung und den Tunnelvortrieb erforderlich. Neben dem Soilfrac®‐Verfahren kamen auch Düsenstrahlverfahren (Soilcrete®) in unterschiedlichster Ausführung zur Anwendung.

Das Soilfrac®‐Verfahren wurde im Wesentlichen aus Arbeitsschächten heraus zur Stabilisierung und Ertüchtigung der aufzufahrenden Tunnelbereiche eingesetzt.

Die Düsenstrahlverfahren wurden unter extrem beengten Arbeitsverhältnissen unter anderem zur Unterfangung von Gebäuden oder zur Herstellung von Dichtblöcken als Einfahrblöcke der Schildvortriebe eingesetzt.

Die Injektionstechniken wurden für verschiedene Bauaufgaben eingesetzt. Im Folgenden werden sieben verschiedene Aufgaben beschrieben.
Hinweise für die Baupreiskalkulation und Arbeitsvorbereitung von Erdbauleistungen beim Einsatz von Geokunststoffbewehrungen
Authors: Biedermann Bernd , Elsing Andreas , Nods Max
Published: September 2007

Die Kalkulation von Erdbauleistungen wird neben den Aufwendungen für Beschaffung und Entsorgung von Bodenmassen insbesondere von der Leistung und den Kosten der Baugeräte geprägt. Methodik und Hilfsmittel zur präzisen Ermittlung dieser Kosten sind weit verbreitet und gängige Praxis. Bei der Vorbereitung und Preisermittlung von Bauleistungen, bei denen Geokunststoffe und vor allem deren Verlegung kalkuliert werden müssen, werden jedoch häufig Potentiale für Kosteneinsparungen verschenkt.

Der vorliegende Beitrag soll diese Potentiale aufzeigen und Anregungen für eine effektivere Kalkulation und Arbeitsvorbereitung liefern.
ELF‐magnetic flux densities measured in a city environment in summer and winter
Authors: Straume Aksel , Johnsson Anders , Oftedal Gunnhild
Published: September 2007

Epidemiological studies have indicated a connection between extremely low frequency magnetic flux densities above 0.4 µT (time weighted average) and childhood leukemia risks. This conclusion is based mainly on indoor exposure measurements. We therefore regarded it important to map outdoor magnetic flux densities in public areas in Trondheim, Norway. Because of seasonal power consumption variations, the fields were measured during both summer and winter. Magnetic flux density was mapped 1.0 m above the ground along 17 km of pavements in downtown Trondheim. The spectrum was measured at some spots and the magnetic flux density emanated mainly from the power frequency of 50 Hz. In summer less than 4% of the streets showed values exceeding 0.4 µT, increasing to 29% and 34% on cold and on snowy winter days, respectively. The average levels were 0.13 µT (summer), 0.85 µT (winter, cold), and 0.90 µT (winter, snow), with the highest recorded value of 37 µT. High spot measurements were usually encountered above underground transformer substations. In winter electric heating of pavements also gave rise to relatively high flux densities. There was no indication that the ICNIRP basic restriction was exceeded. It would be of interest to map the flux density situation in other cities and towns with a cold climate. Bioelectromagnetics 29:20–28, 2008. © 2007 Wiley‐Liss, Inc.
Fluorescence correlation spectroscopy at single molecule level on the Tat–TAR complex and its inhibitors
Authors: Nandi Chayan Kanti , Parui Partha Pratim , Brutschy Bernhard , Scheffer Ute , Göbel Michael
Published: August 2007

The TAR element of HIV and the viral protein Tat form a molecular switch regulating transcriptional efficiency in HIV. We show that fluorescence correlation spectroscopy at the single molecule level is a powerful method to study the association between a Tat‐derived peptide and TAR fragments. We also investigated the inhibition of the peptide–RNA complex by different ligands. Utilizing cross correlation measurements, the dissociation constants (KD) were determined. To demonstrate the important role of the bulge for the binding of Tat, we compared wt‐TAR with three RNA mutants, mainly differing in the bulge region. For the TAR mutants studied at equimolar concentration of RNA and peptide (25 nM), the KD values are 15–35 times larger than that of wt‐TAR. This gives evidence that the bulge region is the most crucial part of the TAR RNA for specific Tat binding. The IC50 values for different inhibitors of the Tat/TAR complex both with wt‐TAR and mutants have been determined. Neamine conjugate proved to be the best inhibitor of the complex formation. Our results are in agreement with earlier published data on this system using alternative biophysical and biochemical methods, respectively. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 17–25, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley. com
Characterization of the distribution of glucose oxidase in Penicillium sp. CBS 120262 and Aspergillus niger NRRL‐3 cultures and its effect on integrated product recovery
Authors: Johnstone‐Robertson M. , Clarke K.G. , Harrison S.T.L.
Published: September 2007

Glucose oxidase (GO) is an important industrial enzyme typically purified from Penicillium and Aspergillus sp. As GO distribution within the cultures influences process design for maximal product recovery, distribution of GO activity in Penicillium sp. CBS 120262 and Aspergillus niger NRRL‐3, during mid‐exponential and stationary phases, is compared. On progression from mid‐exponential to stationary phase, the percentage GO activity in the cytoplasm decreased 1.6‐ and 1.3‐fold in Penicillium sp. and A. niger respectively. In Penicillium sp., a concomitant 1.8‐ and 1.9‐fold decrease in the percentage GO activity in the cell envelope and slime mucilage respectively, translated into a 2.0‐fold increase in the extracellular fluid. In A. niger, decreasing cytoplasmic GO activity was accompanied by 1.3‐fold increases in the cell envelope and slime mucilage, with a 1.3‐fold decrease in the extracellular fluid. Similar trends were observed in specific GO activities. As final GO activity recovered is governed by the purification program, recovery from the extracellular fluid plus cell extract or from the extracellular fluid only were compared through simulating processes of varying complexity. A critical yield for each purification stage was identified above which recovery from the extracellular fluid plus cell extract exceeded that from extracellular fluid alone. These results highlight the influence of microorganism, harvest time and efficiency of downstream process on GO activity delivered. In the systems studied, Penicillium sp. is the organism of choice and should be harvested during stationary phase. The purification process chosen should be informed by both enzyme distribution and individual purification stages yields. Biotechnol. Bioeng. 2008;99: 910–918. © 2007 Wiley Periodicals, Inc.
Factor analysis of spectroelectrochemical reduction of FAD reveals the pKa of the reduced state and the reduction pathway
Authors: Malinowski Edmund R. , Barber Michael J. , Whitaker Graham T. , Smith Eugene T.
Published: September 2007

The free flavin adenine dinucleotide (FAD) cofactor is known to exhibit a pH‐dependent midpoint potential involving a simultaneous two‐electron transfer step (n = 2). Uv‐vis spectroelectrochemical reductions of FAD at constant pH, ranging from 5 to 9, were recorded and analyzed by factor analysis. Principal factor analysis was used to determine the number of species present at each pH. The results indicate that only two composite forms of FAD are present: the oxidized and the reduced forms. Window factor analysis was used to extract the concentration profiles of the controlling species. The oxidized form was found to be a single pH‐independent species, whereas the reduced form consists of two species. The pH‐dependent spectroscopic changes of reduced FAD were best modeled by a single proton transfer step involving two different ionization states with an apparent pKa = 6.3. This value compares favorably with those obtained from NMR and from midpoint potential measurements. At pH 6, the reduction of FAD was found to be first order, whereas at pH 9 the reduction is zero order; these observations are explained in terms of the reaction pathway involving xanthine oxidase, its substrate, and the pH. Copyright © 2007 John Wiley & Sons, Ltd.
Can Electrophilicity Act as a Measure of the Redox Potential of First‐Row Transition Metal Ions?
Authors: Moens Jan , Roos Goedele , Jaque Pablo , De Proft Frank , Geerlings Paul
Published: August 2007

Previous contributions concerning the computational approach to redox chemistry have made use of thermodynamic cycles and Car–Parrinello molecular dynamics simulations to obtain accurate redox potential values, whereas this article adopts a conceptual density functional theory (DFT) approach. Conceptual DFT descriptors have found widespread use in the study of thermodynamic and kinetic aspects of a variety of organic and inorganic reactions. However, redox reactions have not received much attention until now. In this contribution, we prove the usefulness of global and local electrophilicity descriptors for the prediction of the redox characteristics of first row transition metal ions (from Sc3+|Sc2+ to Cu3+|Cu2+) and introduce a scaled definition of the electrophilicity based on the number of electrons an electrophile ideally accepts. This scaled electrophilicity concept acts as a good quantitative estimate of the redox potential. We also identify the first solvation sphere together with the metal ion as the primary active region during the electron uptake process, whereas the second solvation sphere functions as a non‐reactive continuum region.
Preparation of N‐Sulfonyl‐ and N‐Carbonyl‐11‐Azaartemisinins with Greatly Enhanced Thermal Stabilities: in vitro Antimalarial Activities
Authors: Haynes Richard K. , Wong Ho‐Ning , Lee Kin‐Wo , Lung Chung‐Man , Shek Lai Yung , Williams Ian D. , Croft Simon L. , Vivas Livia , Rattray Lauren , Stewart Lindsay , Wong Vincent K. W. , Ko Ben C. B.
Published: September 2007

As the clinically used artemisinins do not withstand the thermal stress testing required to evaluate shelf life for storage in tropical countries where malaria is prevalent, there is a need to develop thermally more robust artemisinin derivatives. Herein we describe the attachment of electron‐withdrawing arene‐ and alkanesulfonyl and ‐carbonyl groups to the nitrogen atom of the readily accessible Ziffer 11‐azaartemisinin to provide the corresponding N‐sulfonyl‐ and ‐carbonylazaartemisinins. Two acylurea analogues were also prepared by treatment of the 11‐azaartemisinin with arylisocyanates. Several of the N‐sulfonylazaartemisinins have melting points above 200 °C and possess substantially greater thermal stabilities than the artemisinins in current clinical use, with the antimalarial activities of several of the arylsulfonyl derivatives being similar to that of artesunate against the drug‐sensitive 3D7 clone of the NF54 isolate and the multidrug‐resistant K1 strain of P. falciparum. The compounds possess relatively low cytotoxicities. The carbonyl derivatives are less crystalline than the N‐sulfonyl derivatives, but are generally more active as antimalarials. The N‐nitroarylcarbonyl and arylurea derivatives possess sub‐ng ml−1 activities. Although several of the azaartemisinins possess log P values below 3.5, the compounds have poor aqueous solubility (<1 mg L−1 at pH 7). The greatly enhanced thermal stability of our artemisinins suggests that strategic incorporation of electron‐withdrawing polar groups into both new artemisinin derivatives and totally synthetic trioxanes or trioxolanes may assist in the generation of practical new antimalarial drugs which will be stable to storage conditions in the field, while retaining favorable physicochemical properties.
Cyberknife radiosurgery for breast cancer spine metastases
Authors: Gagnon Gregory J. , Henderson Fraser C. , Gehan Edmund A. , Sanford Donna , Collins Brian T. , Moulds Jefferson C. , Dritschilo Anatoly
Published: September 2007

BACKGROUND.

There are few options for breast cancer patients with spinal metastases recurrent within a previous radiation treatment field. CyberKnife radiosurgery has been used in our institution to treat such patients. To evaluate their outcomes, as there are no comparable radiation treatment options, the outcomes were compared between 18 patients with spinal metastases from breast cancer treated with CyberKnife stereotactic radiosurgery, 17 of which had prior radiotherapy to the involved spinal region and were progressing, and 18 matched patients who received conventional external beam radiotherapy (CRT) up‐front for spinal metastases.

METHODS.

Radiosurgery was delivered in 3 to 5 fractions to doses ranging from 2100 to 2800 cGy. Women were matched to patients in a CRT group with respect to time from original diagnosis to diagnosis of metastases, estrogen receptor / progesterone receptor (ER/PR) status, presence or absence of visceral metastases, prior radiotherapy, and prior chemotherapy. Survival and complications were compared between treatment groups. Surviving patients were followed out to 24 months.

RESULTS.

The CyberKnife and CRT groups were comparable along all matching dimensions and in performance status before treatment. Outcomes of treatment were similar for patients in both groups; ambulation, performance status, and pain worsened similarly across groups posttreatment. Survival and the number of complications appeared to favor the CyberKnife group, but the differences did not reach statistical significance.

CONCLUSIONS.

The statistical comparability of the CyberKnife and CRT groups reflects the small sample size and stringent requirements for significance of the matched‐pair analysis. Nevertheless, comparability in these difficult cases shows that salvage CyberKnife treatment is as efficacious as initial CRT without added toxicity. Cancer 2007. © 2007 American Cancer Society.
An approach to coupled thermal hydraulics and structural mechanics problems for the MEGAPIE spallation source target
Authors: Smith Brian L. , Ni Liping , Zucchini Alberto
Published: August 2007

This paper describes some novel heat transfer and stress analysis problems that arose in the context of demonstrating the cooling principle of a liquid–metal neutron spallation source target. The design studies using computational fluid dynamics (CFD) resulted in an optimum flow configuration being defined for the coolant circulation. Simultaneously, stresses in the structural components were examined using finite element method (FEM) techniques. Central to the coupled CFD/FEM analysis strategy was the construction of an interface program, which enabled different specialist groups to carry out the thermal hydraulics and structural mechanics analyses using different commercial or in‐house software packages within a common project, and with fully consistent model data. For the studies reported here, the commercial CFD code CFX‐4 and the commercial structural analysis codes ABAQUS and ANSYS have been employed. Results for steady‐state operation of the target show that the critical lower target components are adequately cooled, and that stresses and displacements are well within tolerances. Transient analysis of a beamtrip and power‐up event is also described, showing that no stress crisis occurs. Copyright © 2007 John Wiley & Sons, Ltd.
Strontium deficient feldspar – structure and X – ray powder diffraction line broadening analysis
Authors: Nedić B. , Kremenović A. , Dondur V. , Dimitrijević R.
Published: August 2007

Vacant Sr‐feldspar was synthesized by thermal transformation of FAU zeolite and the structure was refined (space group I2/c). Two refinement procedures were performed: with and without micro strain modelling. Reliable structure model was achieved only with including micro strain modelling. Vacancies in the Sr2+ positions produce micro strain. The concentration of vacancies was the highest along [011] direction. (© 2007 WILEY ‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bauinvestitionen im Zeichen des demografischen Wandels – Rahmenbedingungen für die Wohnungswirtschaft
Authors: Rychter Alexander
Published: September 2007

In Deutschland wird in den kommenden Jahrzehnten die Zahl älterer Menschen infolge des demografischen Wandels deutlich zunehmen. Die entscheidenden Zahlen sind hinreichend bekannt: Schon im Jahr 2020 ist jeder vierte Deutsche älter als 65 Jahre, wobei sich diese Entwicklung in den kommenden Jahren weiter dynamisieren wird. Die Wohnungs‐ und Immobilienwirtschaft muss sich daher auf diese gravierenden Veränderungen einstellen. Tatsache ist: Die Zielgruppen an den Immobilienmärkten kehren sich schlichtweg um. Haben sich viele Bauträger noch in den vergangenen Jahrzehnten vornehmlich auf die Kundengruppe der jungen Familie im Einfamilienhaussektor konzentrieren können, steht heute immer mehr der ältere Mieter oder Käufer mit seinen besonderen Ansprüchen an eine Immobilie im Mittelpunkt des Interesses.
Schadensvermeidung bei Kelleraußenwänden aus Mauerwerk
Authors: Burkert Rainer
Published: September 2007

Mauerwerk ist für die Ausführung von Kellerwänden eine traditionelle, bewährte und auch gute Bauweise. In Anbetracht der heute üblichen kleineren Grundstücke und den sich daraus ergebenden Gebäudemaßen sowie aus wirtschaftlichen Gesichtspunkten sind Keller von der Mehrzahl der Bauherren nach wie vor auch gewünscht. Allerdings haben sich in den letzten 20 Jahren sowohl die Anforderungen an die Konstruktion, die verwendeten Materialien sowie die Rahmenbedingungen bei der Erstellung und Nutzung nachhaltig geändert.

In diesem Zusammenhang treten bei der Erstellung von Kellermauerwerk Schäden auf, die der Autor für unnötig und leicht vermeidbar hält. Schadensursache ist meist nicht das verwendete Steinmaterial, sondern dessen unsachgemäße Verwendung durch fehlende oder falsche Planung.

Die Reaktion “wir haben das schon immer so gemacht” ist sicher falsch und nicht vertretbar. Als Ingenieure stellen wir uns damit ein schlechtes Zeugnis aus.
Flexible und barrierearme Bauten mit Mauerwerk
Authors: Seim Werner
Published: September 2007

Flexible Nutzungsmöglichkeiten und möglichst wenig Barrieren – dies sind zwei grundsätzliche Anforderungen, die bei allen Planungsentscheidungen im Hochbau bereits heute und in Zukunft noch verstärkt zu berücksichtigen sind. Einige statistische Daten, die in diesem Zusammenhang von Bedeutung sind, werden zitiert, und es wird erörtert, wie im Bestand die Nutzungsqualität mit angemessenem Aufwand erhöht werden kann. Für den Mauerwerksbau wird dargelegt, welche Konsequenzen sich aus der Forderung nach flexibleren Grundrissen ergeben. Dabei wird Bezug auf ein aktuelles Forschungsvorhaben genommen, das sich mit der örtlichen Verstärkung von Mauerwerkskonstruktionen mit aufgeklebten Faserverbundwerkstoffen befasst.
Leitbild Bauwirtschaft – Sinn, Nutzen und Entwicklung
Authors: Halstenberg Michael
Published: September 2007

Die Bundesregierung hat einen Leitbildprozess der Branche angestoßen, sie moderiert und fördert ihn. Man kann provokant fragen: Ist das die Aufgabe einer Regierung? Wird ein solcher Prozess überhaupt benötigt und warum? Fragen, die durch eine Analyse der Entwicklung und der aktuellen Situation der Bauwirtschaft beantwortet werden sollen.
Synthesis, Structure and Magnetic Behaviour of Manganese(II) Selenolate Complexes ∞1[Mn(SePh)2], [Mn(SePh)2(bipy)2] and [Mn(SePh)2(phen)2] (bipy = bipyridyl, phen = phenanthroline)
Authors: Eichhöfer Andreas , Wood Paul T. , Viswanath Raghavan , Mole Richard A.
Published: September 2007

The manganese selenolate complex ∞1[Mn(SePh)2] has been prepared by reaction of Mn(OOCCH3)2 with 2 equiv.PhSeSiMe3 in thf. In the crystal structure, the compound forms one‐dimensional chains, and the bridging selenolate ligands result in relatively short metal–metal contacts of about 3 Å. Reaction with two equivalents of the Lewis bases 2,2′‐bipyridine and 1,10‐phenanthroline yielded the monomeric octahedral complexes [Mn(SePh)2(2,2′‐bipy)2] and [Mn(SePh)2(1,10‐phen)2], respectively. The magnetic and optical properties of these complexes have been investigated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Fine‐Tuning Ligands for Catalysis Using Supramolecular Strategies
Authors: Slagt Vincent F. , Kaiser Patrick , Berkessel Albrecht , Kuil Mark , Kluwer Alexander M. , van Leeuwen Piet W. N. M. , Reek Joost N. H.
Published: September 2007

Coordinative bonds have been used to prepare supramolecular ligands leading to well‐defined catalysts formed by assembly. The construction of these ligands is based on selective metal–ligand interactions between nitrogen donor atoms of phosphorus‐nitrogen building blocks and various zinc(II) porphyrins. The major advantage of this supramolecular approach of catalyst preparation is the simplification of ligand variation enabling straightforward modification of steric, electronic and chiral properties of the supramolecular ligand. A large number of new ligands becomes accessible by this modular variation of the building blocks. The ligand assembly based on pyridyl phosphites and zinc(II) porphyrin with electron‐withdrawing substituents led to a twelve‐fold increase in activity and an increase in enantioselectivity from 17 to 50 % in the rhodium‐catalyzed hydrogenation of dimethyl itaconate. The first examples of assemblies based on non‐chiral ligands and chiral zinc(II) porphyrin template molecules show, as proof of principle, an enantiomeric excess up to 18 % in the asymmetric palladium‐catalyzed allylic alkylation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Solid‐State Anion–Guest Encapsulation by Metallosupramolecular Capsules Made from Two Tetranuclear Copper(II) Complexes
Authors: Pardo Emilio , Bernot Kevin , Lloret Francesc , Julve Miguel , Ruiz‐García Rafael , Pasán Jorge , Ruiz‐Pérez Catalina , Cangussu Danielle , Costa Valeria , Lescouëzec Rodrigue , Journaux Yves
Published: September 2007

A new cationic tetranuclear copper(II) complex self‐assembles from one 1,3‐phenylenebis(oxamato) (mpba) bridging ligand and four CuII ions partially blocked with N,N,N′,N′‐tetramethylethylenediamine (tmen) terminal ligands. In the solid state, two of these tetracopper(II) oxamato complexes of bowl‐like shape and helical conformation then serve as a building block for the generation of either hetero‐ (MP) or homochiral (MM/PP) dimeric capsules depending on the nature of the encapsulated anion guest, perchlorate or hexafluorophosphate. The overall magnetic behaviour of these metallosupramolecular capsules does not depend on the nature of the encapsulated anion guest, but it is consistent with the dimer‐of‐dimer structure of the tetracopper(II) cation host, where the interdimer magnetic coupling through the meta‐phenylenediamidate bridge is negligibly smallrelative to the reasonably strong intradimer one across the oxamato bridge.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Cationic P(OPh)3‐ or PPh3‐Rhodium(I) Complex‐Catalyzed Isomerizations of 5‐Alkynals to δ‐Alkynyl Ketones, Cyclopent‐1‐enyl Ketones, and Cyclohexenones
Authors: Tanaka Ken , Sasaki Kaori , Takeishi Kenzo , Hirano Masao
Published: August 2007

We have developed catalytic isomerizations of 5‐alkynals to γ‐alkynyl ketones and cyclopent‐1‐enyl ketones using [Rh{P(OPh)3}2]BF4 as a catalyst. Cu(OTf)2 and AgBF4 are also effective catalysts for the formation of γ‐alkynyl ketones. The substituents at the 4‐positions in 5‐alkynals play important roles in the selection of two different isomerization pathways. The first catalytic endo/trans hydroacylation of acyclic 5‐alkynals leading to cyclohexenones was also developed with [Rh(PPh3)2]BF4 as a catalyst. Crossover deuterium‐labeling studies indicated that these isomerization reactions proceed intramolecularly.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Fast DKR of Amines Using Isopropyl 2‐Methoxyacetate as Acyl Donor
Authors: Veld Martijn A. J. , Hult Karl , Palmans Anja R. A. , Meijer E. W.
Published: September 2007

The dynamic kinetic resolution (DKR) of various primary amine substrates was performed using a modified version of the Bäckvall system. A single equivalent of isopropyl 2‐methoxyacetate was used as acyl donor in combination with p‐MeO Shvo complex as the racemization catalyst and Novozym 435 as the acylation catalyst. A reaction temperature of 100 °C was employed to ensure a high racemization rate. Adding 2,4‐dimethyl‐3‐pentanol (DMP) as hydrogen donor at a concentration of 0.5 M successfully suppressed side product formation. Under these modified DKR conditions, complete conversion was observed for most substrates within 26 h showing both high ee values and good chemoselectivity, whereas the original system required a reaction time of 72 h.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Contactless conductivity detection of sodium monofluoroacetate in fruit juices on a CE microchip
Authors: Lu Qin , Wu Peter , Collins Greg E.
Published: September 2007

Rapid and quantitative determination of sodium monofluoroacetate in diluted fruit juices (dilution 1:9 v/v in deionized water) and tap water was performed by microchip CE, using contactless conductivity detection. A separation buffer consisting of 20 mM citric acid and histidine at pH 3.5 enabled the detection of the monofluoroacetate (MFA) anion in diluted apple juice, cranberry juice, and orange juice without lengthy sample pretreatments. The analyte was very well separated from interfering anionic species present in juices and tap water. LODs in diluted juices and tap water were determined to be 125, 167, 138, and 173 μg/L for tap water, apple juice, cranberry juice, and orange juice, respectively, based upon an S/N of 3:1. Taking into account the dilution factor, the LODs for juice samples range from 1 to 2 mg/L, which is adequate for monitoring the toxicity of MFA in these juice beverages and tap water. The calibration curves for MFA in diluted fruit juices were linear over the range of 500 μg/L to 80 mg/L. The total analysis time for detecting the MFA anion in fruit juices was less than 5 min, which represents a considerable reduction in analysis time compared to other analytical methods currently used in food analysis.
CE of phytosiderophores and related metal species in plants
Authors: Xuan Yue , Scheuermann Enrico B. , Meda Anderson R. , Jacob Peter , von Wirén Nicolaus , Weber Günther
Published: September 2007

Phytosiderophores (PS) and the closely related substance nicotianamine (NA) are key substances in metal uptake into graminaceous plants. Here, the CE separation of these substances and related metal species is demonstrated. In particular, the three PS 2′‐deoxymugineic acid (DMA), mugineic acid (MA), and 3‐epi‐hydroxymugineic acid (epi‐HMA), and NA, are separated using MES/Tris buffer at pH 7.3. Moreover, three Fe(III) species of the different PS are separated without any stability problems, which are often present in chromatographic analyses. Also divalent metal species of Cu, Ni, and Zn with the ligands DMA and NA are separated with the same method. By using a special, zwitterionic CE capillary, even the separation of two isomeric Fe(III) chelates with the ligand ethylenediamine‐N,N′‐bis(o‐hydroxyphenyl)acetic acid (EDDHA) is possible (i.e., meso‐Fe(III)‐EDDHA and rac‐Fe(III)‐EDDHA), and for fast separations of NA and respective divalent and trivalent metal species, a polymer CE microchip with suppressed EOF is described. The proposed CE method is applicable to real plant samples, and enables to detect changes of metal species (Cu‐DMA, Ni‐NA), which are directly correlated to biological processes.
Utility of toluidine blue in oral premalignant lesions and squamous cell carcinoma: Continuing research and implications for clinical practice
Authors: Epstein Joel B. , Sciubba James , Silverman Sol , Sroussi Herve Y.
Published: August 2007

Toluidine blue (TB) has been shown to aid in the detection and diagnosis of oropharyngeal squamous cell carcinoma (OSCC) and oral premalignant lesions (OPLs). TB has been shown to enhance visualization of oral lesions and assist in identifying sites of increased risk of dysplastic/malignant change and promote biopsy. TB has been shown to identify lesions with molecular changes associated with risk of progression of OPLs to OSCC. A recent prospective longitudinal study showed TB retention in histologic benign lesions and lesions with mild dysplasia that are at increased risk of progression to cancer. Clinical trials show that TB is useful in identifying asymptomatic OSCC and premalignant lesions at risk of progressing to SCC, which might otherwise be undetected until lesions become more advanced. The data supports TB use in oral examination of patients at risk of OSCC. © 2007 Wiley Periodicals, Inc. Head Neck 2007
Development of prototype for navigated real‐time sonography for the head and neck region
Authors: Helbig Matthias , Krysztoforski Krzysztof , Krowicki Pawel , Helbig Silke , Gstoettner Wolfgang , Kozak Josef
Published: August 2007

Background.

To date, few imaging methods have been established for the head and neck region, in particular for soft tissues, that allow adequate visualization and simultaneously adequate real‐time orientation.

Methods.

We report a new method using a navigated ultrasound device and a navigated surgical instrument that allows—even in the absence of bony landmarks—appropriate visualization and reliable orientation in real time.

Results.

The practical applicability of the system was tested. Good handling and acceptance of the system could be shown. The “3‐dimensional error” derived from the deviations in all 3 dimensions lies at 0.64 mm.

Conclusions.

With this ultrasound‐guided navigated procedure, an accurate approach of soft tissue structures with a surgical instrument is possible. Changes of the situs are represented in real time. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
A nonlinear data‐driven model for synthetic generation of annual streamflows
Authors: Sudheer K. P. , Srinivasan K. , Neelakantan T. R. , Srinivas V. V.
Published: September 2007

A hybrid model that blends two non‐linear data‐driven models, i.e. an artificial neural network (ANN) and a moving block bootstrap (MBB), is proposed for modelling annual streamflows of rivers that exhibit complex dependence. In the proposed model, the annual streamflows are modelled initially using a radial basis function ANN model. The residuals extracted from the neural network model are resampled using the non‐parametric resampling technique MBB to obtain innovations, which are then added back to the ANN‐modelled flows to generate synthetic replicates. The model has been applied to three annual streamflow records with variable record length, selected from different geographic regions, namely Africa, USA and former USSR. The performance of the proposed ANN‐based non‐linear hybrid model has been compared with that of the linear parametric hybrid model. The results from the case studies indicate that the proposed ANN‐based hybrid model (ANNHM) is able to reproduce the skewness present in the streamflows better compared to the linear parametric‐based hybrid model (LPHM), owing to the effective capturing of the non‐linearities. Moreover, the ANNHM, being a completely data‐driven model, reproduces the features of the marginal distribution more closely than the LPHM, but offers less smoothing and no extrapolation value. It is observed that even though the preservation of the linear dependence structure by the ANNHM is inferior to the LPHM, the effective blending of the two non‐linear models helps the ANNHM to predict the drought and the storage characteristics efficiently. Copyright © 2007 John Wiley & Sons, Ltd.
Herpes oncolytic therapy of salivary gland carcinomas
Authors: Reid Vincent , Yu Zhenkun , Schuman Theodore , Li Sen , Singh Paramjeet , Fong Yuman , Wong Richard J.
Published: August 2007

Oncolytic herpes simplex viruses (HSV) have demonstrated potent antitumoral effects against a variety of human malignancies in preclinical studies and are in early clinical trials. We explored the activity of an attenuated, replication‐competent, oncolytic HSV (NV1023) for the treatment of human salivary gland carcinomas. NV1023 was able to successfully enter into 4 mucoepidermoid carcinoma (H292, H3118, HTB‐41, UT‐MUC‐1) and 2 adenocarcinoma (HSY, HSG) cell lines, as measured by lacZ assays after exposure to 5 viral particles per cell (MOI 5). Viral plaque assays showed variation of viral replication within these cell lines, ranging from a 268‐fold increase (H292) to a 3‐fold increase (HSG) in viral titer. At MOI 5, all cell lines showed >95% cytotoxicity from NV1023 by Day 7, except for HSY (73%). At MOI 0.1, H3118 and UT‐MUC‐1 remained highly sensitive to NV1023, both showing >95% cytotoxicity by Day 7. The mucoepidermoid carcinomas were more sensitive to NV1023 at low viral concentrations compared with the adenocarcinomas. Flank tumors of H3118, HTB‐41 and HSY in nude mice showed significant tumor volume reductions after a single intratumoral injection of NV1023 (2 × 107 plaque‐forming units). These data suggest that oncolytic herpes viruses have significant efficacy entering, replicating within, and lysing human salivary gland carcinomas. These promising biologic agents should be further investigated as novel therapy for patients with salivary carcinomas failing conventional treatment. © 2007 Wiley‐Liss, Inc.
Testicular cancer: Marked birth cohort effects on incidence and a decline in mortality in southern Netherlands since 1970
Authors: Verhoeven Rob , Houterman Saskia , Kiemeney Bart , Koldewijn Evert , Coebergh Jan Willem
Published: August 2007

The aim of our study was to interpret the changing incidence, and to describe the mortality of patients with testicular cancer in the south of the Netherlands between 1970 and 2004. On the basis of data from the Eindhoven Cancer Registry and Statistics Netherlands, 5‐year moving average standardised incidence and mortality rates were calculated. An age‐period‐cohort (APC) Poisson regression analysis was performed to disentangle time and birth cohort effects on incidence. The incidence rate remained stable for all ages at about 3 per 100,000 person‐years until 1989 but increased annually thereafter by 4% to 6 in 2004. This increase can almost completely be attributed to an increase in localised tumours. The largest increase was found for seminoma testicular cancer (TC) patients aged 35–39 and non‐seminoma TC patients aged 20–24 years. Relatively more localised and tumours with lymph node metastases were detected in the later periods. APC analysis showed the best fit with an age‐cohort model. An increase in incidence of TC was found for birth cohorts since 1950. The mortality rate dropped from 1.0 per 100,000 person‐years in 1970 to 0.3 in 2005, with a steep annual decline of 12% in the period 1979–1986. In conclusion, the increase in incidence of TC was strongly correlated with birth cohorts since 1945. The increase in incidence is possibly caused by in utero or early life exposure to a yet unknown risk factor. There was a steep decline in mortality in the period 1979–1986. © 2007 Wiley‐Liss, Inc.
Human papillomavirus genotypes and HPV16 variants in penile carcinoma
Authors: Tornesello Maria Lina , Duraturo Maria Luisa , Losito Simona , Botti Gerardo , Pilotti Silvana , Stefanon Bernardina , Palo Giuseppe De , Gallo Antonio , Buonaguro Luigi , Buonaguro Franco M
Published: August 2007

The causative role of human papillomaviruses (HPV) and HPV16 variants has been extensively studied in uterine cervix dysplastic lesions and invasive carcinoma; few such studies, however, have been performed in penile tumors. We have investigated HPV genotype and HPV16 variant distribution on 41 penile cancer biopsies from Italian patients. Cases were extracted from the respective pathology departments databases of National Cancer Institutes in Naples and Milan. HPV sequences were detected by PCR and characterized by direct sequence analysis. Among the 19 HPV‐positive cases (46.3%) 2 viral genotypes were identified (HPV16 and 18) with HPV16 accounting for 94.7% (18 out of 19) of the infections. Sequence analysis of E6, E7 genes and long control region (LCR) of 18 HPV16 isolates allowed the identification of European (E‐G‐350) and non‐European (AA and Af‐1) variants in 44.4% and in 55.6% of the samples, respectively. The AA variant alone represented 44.4% of all HPV16 infections, a significantly higher frequency of that observed in cervical carcinoma from Italian women (Tornesello et al., J Med Virol 2004;74:117‐26). Our results suggest that HPV16 has a very high prevalence among penile cancer patients in Italy and the increased frequency of HPV16 non‐European classes, particularly the AA, suggests that they are more oncogenic than European variants in penile tissue. © 2007 Wiley‐Liss, Inc.