bluuebunny/crossref_metadata_2025 huggingface dataset:
A Blue‐Light‐Emitting Polymer with a Rigid Backbone for Enhanced Color Stability
Authors: Park S. H. , Jin Y. , Kim J. Y. , Kim S. H. , Kim J. , Suh H. , Lee K.
Published: August 2007

Despite the promising expectations of poly(fluorene) (PF)‐type materials as efficient blue‐light‐emitting polymers, the devices based on these materials are not yet fully utilized. Under prolonged operation of the devices, the PF‐type materials undergo degradation with the appearance of a long‐range emission around 2.2–2.3 eV. As a consequence, the emissive color changes from blue to green with a decrease in the device efficiency. Here, an innovative approach that leads to a new blue‐emitting polymer with remarkable color stability is reported. By modifying the chemical structure of PF to inhibit the formation of keto defects, it is demonstrated that the devices exhibit excellent color stability. This new blue‐emitting polymer, poly(2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta‐[def]phenanthrene)) (PCPP), emits a stabilized, efficient blue electroluminescence without exhibiting any peak in the long‐wavelength region even after prolonged operation of the devices in air.
High Electroactivity of Polyaniline in Supercapacitors by Using a Hierarchically Porous Carbon Monolith as a Support
Authors: Fan L.‐Z. , Hu Y.‐S. , Maier J. , Adelhelm P. , Smarsly B. , Antonietti M.
Published: August 2007

A high‐performance polyaniline electrode was prepared by potentiostatic deposition of aniline on a hierarchically porous carbon monolith (HPCM), which was carbonized from the mesophase pitch. A capacitance value as high as 2200 F g–1 (per weight of polyaniline) is obtained at a power density of 0.47 kW kg–1 and an energy density of 300 W h kg–1. This active material deposited on HPCM also has the advantageous of high stability. These properties can be essentially attributed to the backbone role of HPCM. The method also has the advantage of a topology that is favorable for kinetics at high power densities, thus, contributing to the increase of ionic conductivity and power density. There is also no need for a binder, which not only lowers the preparation costs but also offers advantages in terms of stability and performance.
Improving the robustness and efficiency of crude scheduling algorithms
Authors: Li Jie , Li Wenkai , Karimi I. A. , Srinivasan Rajagopalan
Published: August 2007

Higher crude prices have made it even more imperative that refiners blend low‐quality and high‐quality crudes optimally to maximize their margins. Mathematical modeling of crude blending results in bilinear terms, which combined with commonly used feed quality specifications, make crude scheduling a large, nonconvex, mixed‐integer nonlinear optimization problem. The existing literature algorithms and software (DICOPT/GAMS and BARON/GAMS; Brooke et al., GAMS: a user's guide, GAMS, 1998) fail to solve practical instances of this difficult and useful problem. In this paper, we first enhance the practical utility of our previous crude scheduling algorithm by adding 15 properties and corresponding linearly additive indices, which are used in the refinery industry to ensure feed quality. Then, we propose some new iterative strategies to improve the robustness and solution quality of this algorithm. We also propose a partial relaxation strategy to increase its solution speed. We prove its enhanced performance using 24 industry‐scale examples, and estimate bounds on solution quality. In contrast to existing algorithms or software that fail to solve most of these problems, our revised algorithm solves all problems successfully and gives profits within 6% of our computed upper bounds. © 2007 American Institute of Chemical Engineers AIChE J, 2007
Dominantly‐inherited lop ears
Authors: Leung Alexander K.C. , Kong Albert Y.F. , Robson W. Lane M. , McLeod D. Ross
Published: August 2007

We describe a four‐generation Chinese family that included five members who had an isolated bilateral lop ear anomaly. The presentation suggested a dominant mode of inheritance. The absence of male‐to‐male transmission does not exclude an X‐linked dominant mode of inheritance. Since the phenotypic anomaly of the male proband was no more severe than the affected female members, an autosomal dominant mode of inheritance is most likely. © 2007 Wiley‐Liss, Inc.
Diaphanospondylodysostosis: Six new cases and exclusion of the candidate genes, PAX1 and MEOX1
Authors: Vatanavicharn Nithiwat , Graham John M. , Curry Cynthia J. , Pepkowitz Samuel , Lachman Ralph S. , Rimoin David L. , Wilcox William R.
Published: August 2007

We report on six cases from four families with the newly described skeletal disorder diaphanospondylodysostosis (DSD). The characteristic radiographic findings included abnormal ossification of vertebral bodies, posterior rib gaps, missing ribs, and a downward tilt of the pubic rami, but normal long bones. The typical facial features of DSD cases were ocular hypertelorism, a short nose, depressed nasal bridge, and low set ears. Other distinctive findings included a short neck with bell‐shaped thorax, and nephroblastomatosis. A history of consanguinity and affected siblings with unaffected parents supports autosomal recessive inheritance. Skeletal histology showed incomplete ossification of the ribs, vertebral bodies, and sacrum as well as incomplete formation of intervertebral discs. The posterior ribs were comprised of bone with intervening cartilage interrupted by dense fibrous tissue and skeletal muscle fascicles. These findings suggest abnormal development and differentiation of the paraxial mesoderm. Because of phenotypic similarities of DSD to Pax1 and Meox1 deficient mice, we sequenced genomic DNA from three unrelated DSD cases. No mutations were identified in the PAX1 and MEOX1 exons or flanking intronic sequences, excluding them as likely causative genes. © 2007 Wiley‐Liss, Inc.
Temperature‐Induced Chiroptical Changes in a Helical Poly(phenylacetylene) Bearing N,N‐Diisopropylaminomethyl Groups with Chiral Acids in Water
Authors: Nagai Kanji , Maeda Katsuhiro , Takeyama Yoshihisa , Sato Takahiro , Yashima Eiji
Published: August 2007

A stereoregular poly(phenylacetylene) bearing an N,N‐diisopropylaminomethyl group as the pendant (poly‐1) changed its structure into the prevailing one‐handed helical conformation upon complexation with optically active acids in water. The complexes exhibited induced circular dichroism (ICD) in the UV/Vis region of the polymer backbone. Poly‐1 is highly sensitive to the chirality of chiral acids and can detect a small enantiomeric imbalance in these acids, in particular, phenyl lactic acid in water. For example, a 0.005 % enantiomeric excess of phenyl lactic acid can be detected by CD spectroscopy. The observed ICD intensity and pattern of poly‐1 were dependent on the temperature and concentration of poly‐1, probably due to aggregations of the polymer at high temperature as revealed by dynamic light scattering and AFM. On the basis of the temperature‐dependent ICD changes, the preferred chiral helical sense of poly‐1 was found to be controlled by noncovalent bonding interactions by using structurally different enantiomeric acids.
Enhancement of thermal stability and inhibition of protein aggregation by osmolytic effect of hydroxyproline
Authors: Kar Karunakar , Kishore Nand
Published: August 2007

A combination of spectroscopic, calorimetric, and microscopic studies to understand the effect of hydroxyproline on the thermal stability, conformation, biological activity, and aggregation of proteins has been investigated. Significantly increased protein stability and suppression of aggregation is achieved in the presence of hydroxyproline. For example, exceptional increase in the thermal stability of lysozyme up to 26.4°C and myoglobin up to 31.8°C is obtained in the presence of hydroxyproline. The increased thermal stability of the proteins is observed to be accompanied with significant rise of the catalytic activity. Hydroxyproline is observed to prevent lysozyme fibril formation in vitro. Fluorescence and circular dichroism studies indicate induction of tertiary structures of the studied proteins in the presence of hydroxyproline. Preferential hydration of the native state is found to be crucial for the mechanism of protein stabilization by hydroxyproline. We compared the effect of hydroxyproline to that of proline and observed similar increase in the activity and suppression of protein aggregation. The results demonstrate the use of hydroxyproline as a protein stabilizer and in the prevention of protein aggregation and fibril formation. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 339–351, 2007.

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
Force‐Field Development and Molecular Dynamics Simulations of Ferrocene–Peptide Conjugates as a Scaffold for Hydrogenase Mimics
Authors: de Hatten Xavier , Cournia Zoe , Huc Ivan , Smith Jeremy C. , Metzler‐Nolte Nils
Published: August 2007

The increasing importance of hydrogenase enzymes in the new energy research field has led us to examine the structure and dynamics of potential hydrogenase mimics, based on a ferrocene–peptide scaffold, using molecular dynamics (MD) simulations. To enable this MD study, a molecular mechanics force field for ferrocene‐bearing peptides was developed and implemented in the CHARMM simulation package, thus extending the usefulness of the package into peptide–bioorganometallic chemistry. Using the automated frequency‐matching method (AFMM), optimized intramolecular force‐field parameters were generated through quantum chemical reference normal modes. The partial charges for ferrocene were derived by fitting point charges to quantum‐chemically computed electrostatic potentials. The force field was tested against experimental X‐ray crystal structures of dipeptide derivatives of ferrocene‐1,1′‐dicarboxylic acid. The calculations reproduce accurately the molecular geometries, including the characteristic C2‐symmetrical intramolecular hydrogen‐bonding pattern, that were stable over 0.1 μs MD simulations. The crystal packing properties of ferrocene‐1‐(D)alanine‐(D)proline‐1′‐(D)alanine‐(D)proline were also accurately reproduced. The lattice parameters of this crystal were conserved during a 0.1 μs MD simulation and match the experimental values almost exactly. Simulations of the peptides in dichloromethane are also in good agreement with experimental NMR and circular dichroism (CD) data in solution. The developed force field was used to perform MD simulations on novel, as yet unsynthesized peptide fragments that surround the active site of [Ni–Fe] hydrogenase. The results of this simulation lead us to propose an improved design for synthetic peptide‐based hydrogenase models. The presented MD simulation results of metallocenes thereby provide a convincing validation of our proposal to use ferrocene–peptides as minimal enzyme mimics.
Ferromagnetic Coupling in Trinuclear, Partial Cubane CuII Complexes with a μ3‐OH Core: Magnetostructural Correlations
Authors: Sarkar Biswarup , Ray Mau Sinha , Li Yi‐Zhi , Song You , Figuerola Albert , Ruiz Eliseo , Cirera Jordi , Cano Joan , Ghosh Ashutosh
Published: August 2007

Three new trinuclear copper(II) complexes, [(CuL1)3(μ3‐OH)][ClO4]2⋅3 H2O (1), [(CuL2)3(μ3‐OH)][ClO4]2⋅H2O (2), and [(CuL3)3(μ3‐OH)][ClO4]2⋅7 H2O (3) have been synthesized from the three tridentate Schiff bases HL1, HL2, and HL3 (HL1=6‐ aminomethyl‐3‐methyl‐1‐phenyl‐4‐azahex‐2‐en‐1‐one, HL2=6‐aminoethyl‐3‐methyl‐1‐phenyl‐4‐azahex‐2‐en‐1‐one, and HL3=6‐aminodimethyl‐3‐methyl‐1‐phenyl‐4‐azahex‐2‐en‐1‐one). They have been characterized by X‐ray crystallography and IR and UV spectroscopy, and their magnetic properties have been investigated. All the compounds contain a partial cubane [Cu3O4] core consisting of the trinuclear unit [(CuL)3(μ3‐OH)]2+, perchlorate ions, and water molecules. In each of the complexes, the copper atoms are five‐coordinate with a distorted square‐pyramidal geometry except complex 1, in which one of the CuII of the trinuclear unit is weakly coordinated to one of the perchlorate ions. Magnetic measurements performed in SQUID MPMS‐XL7 using polycrystalline samples at an applied field of 2 kOe indicate a global intramolecular ferromagnetic coupling. Magnetostructural correlations have been calculated on the basis of theoretical models without symmetry restriction. Continuous shape measurements are an appropriate tool for establishing the degree of distortion of the CuII from square‐planar geometry. Structural, theoretical, and experimental magnetic data indicate that the higher the degree of distortion, the greater the ferromagnetic coupling.
Chirally Modified Platinum Generated by Adsorption of Cinchonidine Ether Derivatives: Towards Uncovering the Chiral Sites
Authors: Bonalumi Norberto , Vargas Angelo , Ferri Davide , Baiker Alfons
Published: August 2007

The adsorption behavior of O‐methyl and O‐trimethylsilyl derivatives of cinchonidine (CD), employed as chiral modifiers for heterogeneous enantioselective hydrogenations on supported Pt catalysts, has been investigated by using attenuated total reflection infrared spectroscopy (ATR‐IR) and density functional theory (DFT) electronic structure calculations. The ATR‐IR spectroscopic investigation provided detailed insight of the adsorbed modifiers under conditions close to those employed during catalytic processes, and electronic structure calculations were used as a complement to the experiments to uncover the implications of conformational changes in generating the topology of the surface chiral site. The structural investigation of the adsorbed modifiers revealed a relationship between the spatial positions of the ether substituents and the enantiodifferentiation induced by the modified catalyst observed in the hydrogenation of α‐activated ketones. Experiments and calculations corroborate a model, according to which the addition of a bulky ether group to CD reshapes the chiral sites, thus generating catalytic chiral surfaces with different and, in some cases (e.g. hydrogenation of ketopantolactone), even opposite enantioselective properties to those obtained with CD without altering the absolute configuration of the modifier. The study also confirms that active surface conformations of cinchona modifiers are markedly different from those existing in vacuum and in solution, thus underlying the necessity of investigating the surface‐modifier interaction in order to understand enantioselectivity.
“Nanoions”: Fundamental Properties and Analytical Applications of Charged Nanoparticles
Authors: Bishop Kyle J. M. , Grzybowski Bartosz A.
Published: August 2007

Mixtures of oppositely charged nanoparticles (NPs) precipitate sharply only at the point of NP electroneutrality. This behavior—reminiscent of the threshold precipitation of inorganic ions—is specific to the nanoscale and can be attributed to the formation of like‐charged NP clusters stabilized in solution by mutual electrostatic repulsions. NP titrations based on this phenomenon provide a uniquely accurate tool for measuring charges tethered onto nanoscopic objects and for studying the thermodynamics of surface reactions at the nanoscale.
CH Stretching Vibrational Shift of Benzene Dimer: Consistency of Experiment and Calculation
Authors: Wang Weizhou , Pitoňák Michal , Hobza Pavel
Published: August 2007

Three low‐energy structures of the benzene dimer are investigated by several theoretical procedures (RI‐MP2, CCSD(T), RI‐DFT‐D, DFT/BH&H) covering London dispersion energy. The RI‐DFT‐D and CCSD(T) calculations are used to verify the DFT/BH&H dimer characteristics, as only at this level can anharmonic calculations be performed. It is ascertained that the T‐shaped (C2v) structure, in which the CH stretching frequency of the proton donor shows a significant blue shift, is not stable at any level of theory. It is either a transition structure or a minimum which is easily transformed into a parallel‐displaced structure or a T‐shaped (Cs) structure, even at low temperature. Consequently, no blue shift can be detected. On the other hand, the calculated anharmonic IR spectra of the two most stable structures of benzene dimer, namely, the T‐shaped (Cs) and the parallel‐displaced ones, give rise to a small red (and no blue) shift of the CH stretching vibration. This finding is fully consistent with the experimental results.
Copper Bis(1‐methyl‐5‐nitriminotetrazolate): A Promising New Primary Explosive
Authors: Geisberger Georg , Klapötke Thomas M. , Stierstorfer Jörg
Published: August 2007

Copper bis(1‐methyl‐5‐nitriminotetrazolate) (1) was synthesized and investigated as a new primary explosive. Compound 1 was obtained by dehydration of diaquabis(1‐methylnitriminotetrazolato)copper(II) dihydrate (2) or diaquabis(1‐methylnitriminotetrazolato)copper(II) (3) at 120 °C. Complexes 2 and 3 are easily formed by the reaction of 1‐methyl‐5‐nitrimino‐1,2,3,4‐tetrazole (4) with copper(II) nitrate in aqueous solution in high yields. Single crystals of 1 were obtained by recrystallization from dry methanol, whereas wet methanol favors the yield of diaquabis(1‐methyl‐nitriminotetrazolato)copper(II) dimethanolate (5). Compound 1 was characterized by using single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). The sensitivities were investigated by using the BAM drophammer and friction tests, and the heat of formation was calculated on the basis of electronic energies at the B3LYP/SDD level of theory. Compound 1 shows an impact sensitivity that is five times higher and a friction sensitivity that is ten times lower than that of lead azide, which is appropriate. In addition, the long‐term stability of 1 at higher temperatures was tested by using isothermal safety calorimetry (TSC). Compounds 2 and 3 were characterized by single‐crystal X‐ray diffraction, IR spectroscopy, elemental analysis, DSC, bomb calorimetry, and BAM sensitivity tests. In addition, compound 5 was characterized by single‐crystal X‐ray diffraction and elemental analysis. The dehydration of 2 was determined by using thermal gravimetry (TG) to occur by the loss of crystal water in one discrete step. (© WILEY‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
[(Tmp)Co2L] Complexes through Preassembly on 2,6‐Diformyl‐ and 2,6‐Bis(benzylimino)‐4‐methylphenolate Templates
Authors: Paital Alok Ranjan , Sarkar Mrinal , Mikuriya Masahiro , Ray Debashis
Published: August 2007

The reaction of the dinucleating ligand H3L {2‐(2′‐hydroxyphenyl)‐1,3‐bis[4‐(2‐hydroxyphenyl)‐3‐azabut‐3‐enyl]‐1,3‐imidazolidine} with Co(OAc)2·4H2O and NaN3 in MeOH produces the methoxide‐bridged dicobalt complex [CoIII2(μ‐OMe)L(N3)2] (1) under aerobic conditions. If the reaction occurs in the presence of either 2,6‐diformyl‐4‐methylphenolate (dfp–) or 2,6‐bis(benzyliminomethyl)‐4‐methylphenolate (bip–), a preassembly of the [CoII2(OPh)]3+ units takes place on these templates before coordination with L3– in [CoII2(μ‐dfp)L]·3H2O (2·3H2O) and [CoII2(μ‐bip)L]·3H2O (3·3H2O), respectively. Incorporation of these coligands into the structure leads to stabilization of 3+ and 2+ oxidation states of the cobalt. In complex 2, the CoII ions are engaged in a weak antiferromagnetic interaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Solid contents of palm‐based biofuel mixtures with respect to storage and handling
Authors: Chong Chiew Let , Choo Yuen May , Wahid Mohd. Basri
Published: August 2007

The solid content (SC) of biofuel mixtures obtained from mixing crude palm oil (CPO) with medium fuel oil (MFO), and refined palm oil (RPO) with petroleum diesel (PD), was investigated. The SC of these mixtures will impact on their applications, storage and handling. The concentrations of CPO and RPO in the investigated mixtures ranged from 5 to 90% for the CPO‐MFO system and from 0 to 10% for the RPO‐PD system. For CPO/MFO mixtures, their SC exhibited eutectic behavior over the temperature range measured (5–20 °C). Eutectic minima were observed in the 80–90% CPO concentration range for all temperatures. These eutectic minima are due to dilution effects and the formation of van der Waals hydrogen bonds between the asphaltenes in MFO and the triacylglycerols. RPO/PD mixtures did not show any eutectic behavior. The SC for the RPO/PD mixtures were observed to be below 4% at 5 °C after 24 h of tempering and 0% at 15 °C over the same tempering period. When semi‐solid, ambient PO is used as a biofuel, heating is required to liquify it for ease of handling. When mixed with petroleum‐based fuels in the correct proportion, present handling and storage equipment and facilities are adequate for handling these mixtures.
Concentration of squalene from shark liver oil by short‐path distillation
Authors: Pietsch Arne , Jaeger Philip
Published: August 2007

Investigations on the concentration of squalene from shark liver oil using short‐path distillation are presented and compared to alternative techniques. Aspects of chemical composition analysis are discussed as well as physical and sensory properties. A product is obtained with squalene purities above 97% at feed flows of up to 7 kg/h and temperatures between 185 and 230 °C. In order to assure product quality, a simple refractive method is applied. Based on the presented study, scale‐up to industrial production is performed taking into account the complete process for obtaining an acceptable product with a neutral odor.
Separation of squalene from palm fatty acid distillate using adsorption chromatography
Authors: Chua Camilla Soo Leng , Baharin Badlishah Sham , Man Yaakob B. Che , Tan Chin Ping
Published: August 2007

A method to separate squalene from palm fatty acid distillate (PFAD) using neutralization‐hydrolysis‐neutralization before employing adsorption column chromatography was developed. Extraneous matters, especially free fatty acids (83.8%) and acylglycerols (12.7%), were first neutralized and removed before being subjected to hydrolysis by using commercially available, immobilized Candida antartica lipase, at 65 °C for 8 h. Neutralization followed by hydrolysis and repeated neutralization successfully concentrated squalene from an initial amount of 3.76% to 27.5%. Oil extracted from neutralized‐hydrolyzed‐neutralized PFAD was then passed through a Diaion HP‐20 column using reverse‐phase adsorption chromatography. Squalene was desorbed by hexane, with a recovery of 93%.
A Simple One‐Pot Synthesis of Solvatofluorescent Push‐Pull Thiophenes
Authors: Buehrdel Gunther , Beckert Rainer , Birckner Eckhard , Grummt Ulrich‐Walter , Beyer Beatrice , Kluge Stefan , Weston Jamie , Goerls Helmar
Published: August 2007

Depending on the substitution patterns in the sulfanes 1, two different types of thiophenes 3 and 4 can be obtained upon cyclization with a bis‐imidoyl chloride 2. Whereas thiodiglycolic acid diester yielded a thiophene derivative with the expected symmetrical structure, thiodiacetonitrile gives a derivative with an asymmetrical substitution pattern (2,3‐arylamino/4,5‐dicyano). This unexpected finding was confirmed by single‐crystal X‐ray analysis and possibly originates from a 1,2‐rearrangement of a thietanium salt intermediate. These new push‐pull thiophenes are easily accessible in a single step from simple starting materials. Unlike in the case of the derivatives 3, the substitution pattern in 4 was not previously known. A simple hydrolysis of compounds 4 offers a new and efficient route to derivatives of thiomaleic acid anhydrides 6. The 2,3‐dicyano‐4,5‐bis(arylamino)thiophenes 4 exhibit strong solvatofluorescence with unusually large Stokes shifts. Quantum chemical calculations explain the large Stokes shifts as most probably being due to strong structural relaxation upon excitation to the S1 state.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Catalytic Reduction of Phenyl‐Conjugated Acetylenic Halides by Nickel(I) Salen: Cyclization versus Coupling
Authors: Mubarak Mohammad S. , Jennermann Theodore B. , Ischay Michael A. , Peters Dennis G.
Published: August 2007

Cyclic voltammetry and controlled‐potential electrolysis were employed to study the catalytic reduction of five phenyl‐conjugated haloalkynes by nickel(I) salen electrogenerated at carbon cathodes in dimethylformamide containing tetramethylammonium tetrafluoroborate. Electrocatalytic reduction of 7‐bromo‐ and 7‐iodo‐1‐phenyl‐1‐heptyne affords the carbocyclic product, benzylidenecyclohexane, in up to 41 % yield, whereas under similar conditions reduction of 5‐halo‐1‐phenyl‐1‐pentyne and 8‐bromo‐1‐phenyl‐1‐octyne gives benzylidenecyclobutane and benzylidenecycloheptane, respectively, in very low yield (≤1 %). Dimers, alkynes, and alkenynes are other products formed from the phenyl‐conjugated haloalkynes. Dimers (diphenylalkadiynes) derived from 5‐halo‐1‐phenyl‐1‐pentyne and 8‐bromo‐1‐phenyl‐1‐octyne are obtained in yields ranging from 85 to 93 %, whereas 1,14‐diphenyltetradeca‐1,13‐diyne (the dimer produced from 7‐halo‐1‐phenyl‐1‐heptyne) is found in yields of 45–51 %. To account for the formation of the various products, a mechanistic scheme that involves phenyl‐conjugated alkynyl radicals arising from nickel(I) salen catalyzed cleavage of the carbon–halogen bond of each substrate was formulated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Investigating the transport dynamics and the properties of bedload material with a hydro‐acoustic measuring system
Authors: Krein Andreas , Klinck Holger , Eiden Michael , Symader Wolfhard , Bierl Reinhard , Hoffmann Lucien , Pfister Laurent
Published: August 2007

This article deals with the following two questions. Are acoustic measurements in running waters appropriate for a highly resolved investigation of the bedload transport? Which characterizations of the bedload regarding mass and shape are possible via the acoustic signals? The signals were recorded by means of data recorders (Tascam Inc. DAP1 Portable Data Recorder) and hydrophones (International Transducer Corp. ITC‐4001 A). The ITC‐4001 is a shallow water omnidirectional transducer containing a flexural disc transducer utilizing Channelite‐5400 ceramics mounted in a rugged corrosion‐resistant housing. These hydrophones were screwed onto the bottom side of stainless steel plates, serving as a contact surface for the bedload in motion above them. After more than 100 series of tests in the laboratory, which indicated the basic relations between the dimension, shape and weight of the bedload and the resulting signal, field tests of the measuring system were conducted. By artificially produced flood waves in the small brooks Riverisbach, Olewiger Bach and by a winter flood wave in the River Moselle, it is possible to elaborate similar structures of the signal course of the bedload movement. The highest transport rates can be observed at the beginning of the increasing limbs and behind the peaks of the waves. At the beginning of the waves, the increasing transport power of the water and the loose material can be considered as the cause for this result. The high stream velocity behind the wave peaks explains the increase in the bedload transport so that material from the channel beds is unfastened and will be mobilized. The characterization of the bedload regarding the shape and mass is still limited regarding the field measurements and could be solved only for homogeneous grain sizes and single stones under laboratory conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Craniofacial surgery for nonmelanoma skin malignancy: Report of an international collaborative study
Authors: Maghami Ellie G. , Talbot Simon G. , Patel Snehal G. , Singh Bhuvanesh , Polluri Ashok , Bridger Patrick G. , Cantu Giulio , Cheesman Anthony D. , Sa Geraldo De , Donald Paul , dos Santos Luiz R. M. , Fliss Dan , Gullane Patrick , Janecka Ivo , Kamata Shin‐Etsu , Kowalski Luiz P. , Kraus Dennis H. , Levine Paul A. , Pradhan Sultan , Schramm Victor , Snyderman Carl , Wei William I. , Shah Jatin P.
Published: August 2007

Background.

This study examined the efficacy of craniofacial surgery (CFS) in treating locally advanced nonmelanoma skin cancer (NMSC).

Methods.

One hundred twenty patients who underwent CFS for NMSC were identified from 17 participating institutions. Patient, tumor, and treatment information was analyzed for prognostic impact on survival.

Results.

Surgical margins were negative in 74%, close in 3%, and involved in 23% of patients. Complications occurred in 35% of patients, half of which were local wound problems. Operative mortality was 4%. Median follow‐up interval after CFS was 27 months. The 5‐year overall survival (OS), disease‐specific survival (DSS), and recurrence‐free survival (RFS) rates were 64%, 75%, and 60%, respectively. Squamous cell histology, brain invasion, and positive resection margins independently predicted worse OS, DSS, and RFS.

Conclusion.

CFS is an effective treatment for patients with NMSC invading the skull base. Histology, extent of disease, and resection margins are the most significant predictors of outcome. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Preoperative measurement of tumor thickness of oral tongue carcinoma with intraoral ultrasonography
Authors: Yuen Anthony Po‐Wing , Ng Raymond Wai‐Man , Lam Paul Kin‐Yip , Ho Ambrose
Published: August 2007

Background.

Tumor thickness of oral tongue carcinoma is an important independent prognostic factor for local recurrence, subclinical nodal metastasis, and survival. An accurate preoperative assessment of tumor thickness is therefore essential in optimizing treatment algorithm. The present study aims at evaluating the accuracy of intraoral ultrasonography in preoperative measurement of tumor thickness.

Methods.

Forty‐five patients with oral tongue carcinoma had intraoral ultrasonography to document tumor thickness using a 7.5 MHz right angle probe. The ultrasonic tumor thickness was correlated with the fresh unpreserved surgical specimen pathologic tumor thickness.

Results.

Ultrasonic tumor thickness had significant correlation with pathologic tumor thickness. The accuracies of ultrasonic measurement of tumor thickness in staging of tumor thickness at cutoff values between 3 and 15 mm were above 91%.

Conclusion.

Intraoral ultrasonography had satisfactory accuracy in the measurement of tumor thickness and is a useful adjunct in assisting pretreatment staging and prognosis evaluation of oral tongue carcinoma. © 2007 Wiley Periodicals, Inc. Head Neck, 2008
Final report of RTOG 9610, a multi‐institutional trial of reirradiation and chemotherapy for unresectable recurrent squamous cell carcinoma of the head and neck
Authors: Spencer Sharon A. , Harris Jonathan , Wheeler Richard H. , Machtay Mitchell , Schultz Christopher , Spanos William , Rotman Marvin , Meredith Ruby , Ang Kie‐Kian
Published: August 2007

Background.

Our objectives were to determine the incidence of acute and late toxicities and to estimate the 2‐year overall survival for patients treated with reirradiation and chemotherapy for unresectable squamous cell carcinoma of the head and neck (SCCHN).

Methods.

Patients with recurrent squamous cell carcinoma or a second primary arising in a previously irradiated field were eligible. Four weekly cycles of 5‐fluorouracil 300 mg/m2 IV bolus and hydroxyurea 1.5 g by mouth were used with 60 Gy at 1.5 Gy twice‐daily fractions. Toxicity was scored according to Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) criteria.

Results.

Seventy‐nine of the 86 patients enrolled were analyzable. The worst acute toxicity was grade 4 in 17.7% and grade 5 in 7.6%. Grade 3 and 4 late toxicities were found in 19.4% and 3.0%, respectively. The estimated cumulative incidence of grade 3 to 4 late effects occurring at >1 year was 9.4% (95% confidence interval [CI]: 0, 19.7) at 2 and 5 years. The 2‐ and 5‐year cumulative incidence for grade 4 toxicity was 3.1% (95% CI: 0, 9.3). The estimated 2‐ and 5‐year survival rates were 15.2% (95% CI: 7.3, 23.1) and 3.8% (95% CI: 0.8, 8.0), respectively. Patients who entered the study at >1 year from initial radiotherapy (RT) had better survival than did those who were <1 year from prior RT (median survival, 9.8 months vs 5.8 months; p = .036). No correlation was detected between dose received and overall survival. Three patients were alive at 5 years.

Conclusion.

This is the first prospective multi‐institutional trial testing reirradiation plus chemotherapy for recurrent or second SCCHN. The approach is feasible with acceptable acute and late effects. The results serve as a benchmark for ongoing RTOG trials. © 2007 Wiley Periodicals, Inc. Head Neck 2008
Reversible effect of X‐irradiation on proliferation, neurogenesis, and cell death in the dentate gyrus of adult mice
Authors: Ben Abdallah Nada M.‐B. , Slomianka Lutz , Lipp Hans‐Peter
Published: August 2007

Therapeutic cranial X‐irradiation causes cognitive deficits in adult and pediatric patients, in particular, when the exposed area includes the medial temporal lobes. Effects on adult neurogenesis within the hippocampus may be related to such deficits. To investigate this relation, we irradiated the brain of young adult C57Bl/6j mice with a single dose of 4 Gy at a dose‐rate of 27.5 cGy/min. We observed an ∼80% decrease in the number of cells immunoreactive for the proliferation marker Ki67, 16 and 48 h after exposure, which was restored to control values after 1 week. The number of doublecortin‐ and NeuroD‐immunoreactive cells of neuronal lineage was reduced by 60–70% up to 1 week after irradiation, but not after 1 month. The number of pyknotic cells increased ∼2.5 fold after 16 h, decreased to ∼50% of control numbers after 48 h and 1 week, and was again at normal levels after 1 month. Granule cell number did not differ between different groups and time points. There was no apparent activation of microglia or astrocytes. Our findings consist of an acute and reversible effect of X‐irradiation on proliferation, neurogenesis, and cell death. Transient changes of neurogenesis may play a role in transient impairments of cognitive performance of patients exposed to X‐irradiation. We present an experimental approach to temporarily alter adult hippocampal neurogenesis (AhN), allowing mechanistic investigations of AhN and its relevance to cognitive performances. The work also represents a step toward optimized radiotherapy schedules. © 2007 Wiley‐Liss, Inc.
Network dynamics of hippocampal cell‐assemblies resemble multiple spatial maps within single tasks
Authors: Jackson Jadin , Redish A. David
Published: August 2007

The firing of place cells in the rodent hippocampus is reliable enough to infer the rodent's position to a high accuracy; however, hippocampal firing also reflects the stages of complex tasks. Theories have suggested that these task‐stage responses may reflect changes in reference frame related to task‐related subgoals. If the hippocampus represents an environment in multiple ways depending on a task's demands, then switching between these cell assemblies should be detectable as a switch in spatial maps or reference frames. Place cells exhibit extreme temporal variability or “overdispersion,” which Fenton et al. suggest reflects changes in active cell‐assemblies. If reference‐frame switching exists, investigating the relationship of the single cell variability described by Fenton and collegues to network level processes provides an entry point to understanding the relationship between cell‐assembly‐like mechanisms and an animal's behavior. We tested the cell‐assembly explanation for overdispersion by recording hippocampal neural ensembles from rats running three tasks of varying spatial complexity: linear track (LT), cylinder‐foraging (CF), and cylinder‐goal (CG). Consistent with the reports by Fenton and colleagues, hippocampal place cells showed high variance in their firing rates across place field passes on the CF and CG tasks. The directional firing of hippocampal place cells on LT provided a test of the reference‐frame hypothesis: ignoring direction produced overdispersion similar to the CF and CG tasks; taking direction into account produced a significant decrease in overdispersion. To directly examine the possibility of a network modulation of cell‐assemblies, we clustered the firing patterns within each pixel and chained them together to construct whole‐environment spatial firing maps. Maps were internally self‐consistent, switching with mean rates of several hundred milliseconds. There were significant increases in map‐switching rates following reward‐related events on the LT and CG tasks, but not on the CF task. Our results link single cell variability with network‐level processes and imply that hippocampal spatial representations are made up of multiple, continuous submaps, the selection of which depends on the animal's goals when reward is tied to the animal's spatial behavior. © 2007 Wiley‐Liss, Inc.
Outsourcing in the Italian National Health Service: findings from a national survey
Authors: Macinati Manuela S.
Published: August 2007

Over the last decade, outsourcing has become one of the major issues in health care. Two major concerns are related to public health care outsourcing practice. The first one involves the suitability of the outsourcing strategy in the public sector, principally with reference to the outsourcing of essential clinical services. The second one relates to the actual benefits of the outsourcing practice in health care, in terms of cost reduction and increasing efficiency.

This paper aims to contribute to the debate and literature on outsourcing through a national survey carried out in the Italian National Health Service.

In order to achieve the research objective, a questionnaire was developed and, after a pilot test, it was mailed to all Italian public providers. The total response rate was around 42%. Results showed that outsourcing is a widespread phenomenon within health care, especially in the ancillary services area. Moreover, results showed many criticalities of the outsourcing practice in the Italian health‐care sector. On the one hand, criticalities concerned the reasons for outsourcing, the characteristics of the outsourced services and the management of the relationship with the vendor. With reference to essential clinical service, outsourcing, as currently managed by health‐care providers, may potentially weaken their ability to reach its own objectives. On the other hand, criticalities related to respondent‐perceived benefits. Despite the overall positive outsourcing experience expressed in the survey, the results on perceived benefits showed that the effects of outsourcing did not always align to managers' expectations, especially in the cost containment and efficiency area. Copyright © 2007 John Wiley & Sons, Ltd.
Human papillomavirus types in women with invasive cervical carcinoma by HIV status in Kenya
Authors: De Vuyst Hugo , Gichangi Peter , Estambale Benson , Njuguna Eliud , Franceschi Silvia , Temmerman Marleen
Published: August 2007

To evaluate the fraction of invasive cervical carcinoma (ICC) that could be prevented in HIV‐infected women by vaccines currently available against human papillomavirus (HPV)16 and 18, we conducted a cross‐sectional study in women with ICC in Nairobi, Kenya. Fifty‐one HIV‐positive women were frequency‐matched by age to 153 HIV‐negative women. Cervical cells were tested for HPV DNA using polymerase chain reaction‐based assays (SPF10‐INNO‐LiPA). Comparisons were adjusted for multiplicity of HPV types. As expected, multiple‐type infections were much more frequent in HIV‐positive (37.2%) than in HIV‐negative (13.7%) women, but the distribution of HPV types was similar. HPV16 was detected in 41.2% versus 43.8% and HPV16 and/or 18 in 64.7% versus 60.1% of HIV‐positive versus HIV‐negative women, respectively. The only differences of borderline statistical significance were an excess of HPV52 (19.6% versus 5.2%) and a lack of HPV45 (7.8% versus 17.0%) in HIV‐positive women compared to HIV‐negative women, respectively. We have been able to assess an unprecedented number of ICCs in HIV‐positive women, but as we did not know the age of HIV acquisition, we cannot exclude that it had occurred too late in life to affect the type of HPV involved in cervical carcinogenesis. However, if our findings were confirmed, they would suggest that the efficacy of current vaccines against HPV16 and 18 to prevent ICC is similar in HIV‐positive and HIV‐negative women, provided vaccination is administered before sexual debut, as recommended. © 2007 Wiley‐Liss, Inc.
Hepatitis C virus core protein induces spontaneous and persistent activation of peroxisome proliferator‐activated receptor α in transgenic mice: Implications for HCV‐associated hepatocarcinogenesis
Authors: Tanaka Naoki , Moriya Kyoji , Kiyosawa Kendo , Koike Kazuhiko , Aoyama Toshifumi
Published: August 2007

Persistent infection of hepatitis C virus (HCV) can lead to a high risk for hepatocellular carcinoma (HCC). HCV core protein plays important roles in HCV‐related hepatocarcinogenesis, because mice carrying the core protein exhibit multicentric HCCs without hepatic inflammation and fibrosis. However, the precise mechanism of hepatocarcinogenesis in these transgenic mice remains unclear. To evaluate whether the core protein modulates hepatocyte proliferation and apoptosis in vivo, we examined these parameters in 9‐ and 22‐month‐old transgenic mice. Although the numbers of apoptotic hepatocytes and hepatic caspase 3 activities were similar between transgenic and nontransgenic mice, the numbers of proliferating hepatocytes and the levels of numerous proteins such as cyclin D1, cyclin‐dependent kinase 4 and c‐Myc, were markedly increased in an age‐dependent manner in the transgenic mice. This increase was correlated with the activation of peroxisome proliferator‐activated receptor α (PPARα). In these transgenic mice, spontaneous and persistent PPARα activation occurred heterogeneously, which was different from that observed in mice treated with clofibrate, a potent peroxisome proliferator. We further demonstrated that stabilization of PPARα through a possible interaction with HCV core protein and an increase in nonesterified fatty acids, which may serve as endogenous PPARα ligands, in hepatocyte nuclei contributed to the core protein‐specific PPARα activation. In conclusion, these results offer the first suggestion that HCV core protein induces spontaneous, persistent, age‐dependent and heterogeneous activation of PPARα in transgenic mice, which may contribute to the age‐dependent and multicentric hepatocarcinogenesis mediated by the core protein. © 2007 Wiley‐Liss, Inc.
Noncancerous PTGS2 DNA fragments of apoptotic origin in sera of prostate cancer patients qualify as diagnostic and prognostic indicators
Authors: Ellinger Jörg , Bastian Patrick J. , Haan Kim I. , Heukamp Lukas C. , Buettner Reinhard , Fimmers Rolf , Mueller Stefan C. , von Ruecker Alexander
Published: August 2007

Our study was designed to evaluate Cell‐Free DNA in sera of prostate cancer (PCA) patients as a useful biomarker. Real‐time PCR was used to amplify a <200 bp PTGS2 DNA fragment that biochemically characterizes apoptosis and a larger >250 bp Reprimo DNA fragment that defines mostly other cell death entities. The apoptosis index (AI) expresses the ratio of PTGS2 to Reprimo DNA fragments. GSTP1 hypermethylation was assessed to evaluate the amount of tumor‐derived DNA. We analyzed serum of 216 patients (168 PCA; 5 incidental PCA; 42 benign prostatic hyperplasia (BPH); 11 healthy individuals). Distinctly elevated concentrations of PTGS2 fragments were detected in PCA compared to BPH and healthy individuals (median: 70.2, 10.5 and 7.1 ng/ml, respectively; p < 0.0001). The AI was significantly increased in PCA vs. BPH patients and healthy individuals (6.01 vs. 1.54 and 0.84 respectively; p = 0.002–0.0001). GSTP1 hypermethylation was only present in a small percentage (mean 1.92%) of circulating DNA. Concentrations of apoptotic PTGS2 fragments discriminated sensitively (88%) and specifically (64%) between BPH and PCA, whereas the AI was more specific (82%) but less sensitive (70%). The AI correlated with histological grading (p = 0.044). Kaplan–Meier analysis for a subset of 124 patients revealed a significant correlation between apoptotic PTGS2 fragments or the AI and PSA recurrence following radical prostatectomy (p = 0.0395–0.0482). In conclusion, circulating PTGS2 fragments of apoptotic origin and the AI are promising serum biomarkers for the diagnosis and prognosis of PCA. We suggest that cancer‐induced apoptosis of peripheral noncancerous tissues is relevant in many malignancies. © 2007 Wiley‐Liss, Inc.
Dietary fiber intake and risk of postmenopausal breast cancer defined by estrogen and progesterone receptor status—A prospective cohort study among Swedish women
Authors: Suzuki Reiko , Rylander‐Rudqvist Tove , Ye Weimin , Saji Shigehira , Adlercreutz Herman , Wolk Alicja
Published: August 2007

There is few data on the association between dietary fiber intake and estrogen receptor (ER)/progesterone receptor (PR)‐defined breast cancer risk. We evaluated the association between dietary fiber and ER/PR‐defined breast cancer risk stratified by postmenopausal hormone use, alcohol intake, and family history of breast cancer in the population‐based Swedish Mammography Screening Cohort comprising 51,823 postmenopausal women. Fiber intake was measured by food‐frequency questionnaire collected in 1987 and 1997. Relative risks (RRs) were estimated by hazard ratio derived from Cox proportional hazard regression models. During an average of 8.3‐year follow‐up, 1,188 breast cancer cases with known ER/PR status were diagnosed. When comparing the highest to the lowest quintile, we observed non‐significant inverse associations between total fiber intake and the risk of all tumor subtypes; the multivariate‐adjusted RRs were 0.85 (95% CI: 0.69–1.05) for overall, 0.85 (0.64–1.13) for ER+PR+, 0.83 (0.52–1.31) for ER+PR− and 0.94 (0.49–1.80) for ER−PR−. For specific fiber, we observed statistically significant risk reductions for overall (34%) and for ER+PR+ (38%) for the highest versus lowest quintile of fruit fiber, and non‐significant inverse associations for other subtypes of cancer and types of fiber. Among ever‐users of postmenopausal hormone (PMH), total fiber intake and especially cereal fiber were statistically significantly associated with ∼50% reduced risk for overall and ER+PR+ tumors when comparing the highest to the lowest quartile, but no association was observed among PMH never users. Our results suggest that dietary fiber intake from fruit and cereal may play a role in reducing breast cancer risk. © 2007 Wiley‐Liss, Inc.