bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Rate Enhancement in Titanium and Zirconium Alkoxide Mediated Cyano Group Transfers by the Addition of a Salycylal Type Schiff Base, dl-3-(2-Hydroxy-1-naphthylidene)-imino-ε-caprolactam. A Neighboring Amide Effect
Authors: Mori Atsunori , Inoue Shohei 
Published: May 2006

Abstract
The addition of a salycylal type Schiff base containing amide, dl-3-(2-hydroxy-1-naphthylidene)-imino-ε-caprolactam (Nap-ACL) to titanium (IV) 2-propoxide or zirconium (IV) 1-propoxide accelerates cyano group transfers of acetone cyanohydrin with various carbonyl and imino compounds to give the corresponding cyanated products.
Nucleophilic Reactions of Acetals, Alkyl Sulfonates, and Oxiranes with Diisobutylaluminum Benzenetellurolate
Authors: Sasaki Kazuaki , Mori Toshiharu , Doi Yoshitaka , Kawachi Akinori , Aso Yoahio , Otsubo Tetsuo , Ogura Fumio 
Published: May 2006

Abstract
Diisobutylaluminum benzenetellurolate was proved to be an effective nucleophilic reagent toward acetals, alkyl sulfonates, and oxiranes to give the corresponding tellurides. These reactions showed the characteristics of an SN2 type. When the substitution reactions were sterically hindered, olefins and allylic alcohols were obtained from alkyl sulfonates and oxiranes, respectively.
Methods for the detection of bacterial contamination in blood products Screeningverfahren zum Nachweis bakterieller Kontaminationen in Blutprodukten
Authors: Müller Thomas H. , Mohr Harald , Montag Thomas 
Published: May 2006

Abstract
Culture-based and molecular assays have been developed for the screening of platelet concentrates and other blood components for bacterial contamination. The principles of the assays are outlined.
This review focuses on the assessment of the analytical qualities of the methods. Spiking studies by adding defined levels of a wide range of bacteria to the complex biological matrix provide the first basis to evaluate and compare the qualities of methods for bacterial detection. The sensitivity acceptable for a reliable screening for bacteria critically depends on the timing of either early sampling (within a period of up to 24 h after preparation of the blood component) or late sampling (a few hours before issuing the blood component). Large screening studies are essential to confirm both adequate sensitivity and specificity of the testing. In the ideal setting, these studies are prospectively planned and include the systematic surveillance of adverse events in response to the administration of the screened products. The findings from sterility testing (predominantly with automated systems for the detection of bacteria based on CO2 generation) of more than 550,000 platelet concentrates in 13 studies are summarized. The limitations of the early sampling and the “negative-to-date” strategy with regard to issuing platelet concentrates are addressed. A few reported cases of probable bacterial transmission by platelet transfusion despite negative screening tests emphasize the need for further development of optimized methods for the testing of blood components for bacterial contamination.
Rapid screening for bacterial contamination of blood products Schnellverfahren zum Nachweis bakterieller Kontaminationen bei Blutprodukten
Authors: Faure Isabelle Besson 
Published: May 2006

Abstract
Many techniques have been explored to detect bacteria in blood products in order to prevent transfusion-related bacteria contamination (TRBC) and transmission. In a simple way, these techniques may be divided into two groups based on their rapidity to obtain the test result. The culture methods require from several hours to several days to get the final result; the rapid methods require from several minutes to a few hours to detect bacteria in blood products. It is usually stated that the rapid methods have a strong advantage by providing rapid results, but they are also complex and require well trained technicians. By contrast, culture methods are easy to handle but results are available with a certain delay. Today, three devices are commercially available to screen blood components. The BacT/ALERT (Biomérieux) and the eBDS device (Pall) are both automated culture systems based on the measurement of a change in the gas concentration due to bacterial metabolism. The Scansystem™ (Hemosystem) belongs to the second group of methods. It is a fluorescence-based bacteria detection performed in 70 min. Other rapid techniques are being developed, such as flow cytometry or polymerase chain reaction (PCR). Based on their sensitivity and specificity, the intended use of these bacterial detection methods varies from early testing to release a safe product, to late testing close to the transfusion time (point-of-care testing “POCT”) to guarantee a safe transfusion.
Structural Integrity Assessment of Thin‐Walled Structures
Authors: Brocks W. , Schwalbe K.‐H. , Zerbst U. 
Published: May 2006

AbstractAs part of the concept of damage tolerant design, methods for the analytical and numerical simulation of ductile crack extension in thin‐walled structures are presented and discussed. They comprise the application of an analytical flaw assessment procedure as well as finite element analyses based on the crack tip opening displacement (CTOD), δ5, and finite element simulations of crack extension based on the crack tip opening angle (CTOA), a cohesive zone model and a ductile damage model. All these methods are or will become part of the GKSS Structural Integrity Assessment Method (SIAM), which also provides test procedures for the experimental determination of the required material parameters.
Estimating fog deposition at a Puerto Rican elfin cloud forest site: comparison of the water budget and eddy covariance methods
Authors: Holwerda F. , Burkard R. , Eugster W. , Scatena F. N. , Meesters A. G. C. A. , Bruijnzeel L. A. 
Published: May 2006

AbstractThe deposition of fog to a wind‐exposed 3 m tall Puerto Rican cloud forest at 1010 m elevation was studied using the water budget and eddy covariance methods. Fog deposition was calculated from the water budget as throughfall plus stemflow plus interception loss minus rainfall corrected for wind‐induced loss and effect of slope. The eddy covariance method was used to calculate the turbulent liquid cloud water flux from instantaneous turbulent deviations of the surface‐normal wind component and cloud liquid water content as measured at 4 m above the forest canopy. Fog deposition rates according to the water budget under rain‐free conditions (0·11 ± 0·05 mm h−1) and rainy conditions (0·24 ± 0·13 mm h−1) were about three to six times the eddy‐covariance‐based estimate (0·04 ± 0·002 mm h−1). Under rain‐free conditions, water‐budget‐based fog deposition rates were positively correlated with horizontal fluxes of liquid cloud water (as calculated from wind speed and liquid water content data). Under rainy conditions, the correlation became very poor, presumably because of errors in the corrected rainfall amounts and very high spatial variability in throughfall. It was demonstrated that the turbulent liquid cloud water fluxes as measured at 4 m above the forest could be only ∼40% of the fluxes at the canopy level itself due to condensation of moisture in air moving upslope. Other factors, which may have contributed to the discrepancy in results obtained with the two methods, were related to effects of footprint mismatch and methodological problems with rainfall measurements under the prevailing windy conditions. Best estimates of annual fog deposition amounted to ∼770 mm year−1 for the summit cloud forest just below the ridge top (according to the water budget method) and ∼785 mm year−1 for the cloud forest on the lower windward slope (using the eddy‐covariance‐based deposition rate corrected for estimated vertical flux divergence). Copyright © 2006 John Wiley & Sons, Ltd.
Capillary gas‐chromatographic determination of spermidine in hair lotion
Authors: Gambaro Veniero , Casagni Eleonora , Dell'Acqua Lucia , Valenti Mauro , Visconti Giacomo L. 
Published: May 2006

AbstractBiogenic polyamines, such as spermidine (SPD, NH2–(CH2)4–NH–(CH2)3–NH2), are ubiquitous polycationic molecules which play a definitive role in many biological processes such as nucleic acid metabolism, protein synthesis, and cell growth. SPD is commonly used as an ingredient in hair lotions, because it seems to promote hair growth. This work describes a capillary GC method for quantitative determination of SPD in hair lotions using 1,6‐diaminohexane as internal standard, a methyl silicone capillary column, and a flame ionisation detector. Aliquots of hair lotion were treated with an alkaline aqueous solution and internal standard was added. The emulsion was extracted with diethyl ether containing ethyl chloroformate. Ether extracts, evaporated to dryness and reconstituted in ethyl acetate, were analysed by capillary GC with flame ionisation detection. Validation took into account the specificity, linearity, precision, and accuracy of the analytical method: these parameters were valid for the quantitative determination of SPD in hair lotion.
Thermal dissociation behavior of copolymers bearing hemiacetal ester moieties and their reactions with epoxides
Authors: Komatsu Hiroyuki , Hino Tetsuo , Endo Takeshi 
Published: May 2006

AbstractCopolymers from 1‐propoxyethyl methacrylate and various vinyl monomers such as n‐butyl methacrylate and styrene were synthesized, and the thermal dissociation reaction of the copolymers containing the hemiacetal ester structure was examined. The copolymers, having the ability of thermal dissociation, could control the thermal dissociation temperature because of the bulkiness and flexibility of the vinyl comonomers, the copolymer compositions, and so on. Furthermore, the possibility of control of the initiation in thermally latent addition with epoxides in the case of copolymers was also studied. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3966–3977, 2006
Sorption–desorption of flucarbazone and propoxycarbazone and their benzenesulfonamide and triazolinone metabolites in two soils
Authors: Koskinen William C , Calderón María Jesus , Rice Pamela J , Cornejo Juan 
Published: May 2006

AbstractSorption–desorption interactions of pesticides with soil determine the availability of pesticides in soil for transport, plant uptake and microbial degradation. These interactions are affected by the physical and chemical properties of the pesticide and soil and, for some pesticides, their residence time in the soil. While sorption–desorption of many herbicides has been characterised, very little work in this area has been done on herbicide metabolites. The objective of this study was to characterise sorption–desorption of two sulfonylaminocarbonyltriazolinone herbicides, flucarbazone and propoxycarbazone, and their benzenesulfonamide and triazolinone metabolites in two soils with different physical and chemical properties.Kfvalues for all four chemicals were greater in clay loam soil, which had higher organic carbon and clay contents than loamy sand.Kf−ocranged from 29 to 119 for the herbicides and from 42 to 84 for the metabolites. Desorption was hysteretic in every case. Lower desorption in the more sorptive system might indicate that hysteresis can be attributed to irreversible binding of the molecules to soil surfaces. These data show the importance of characterisation of both sorption and desorption of herbicide residues in soil, particularly in the case of prediction of herbicide residue transport. In this case, potential transport of sulfonylaminocarbonyltriazolinone herbicide metabolites would be overpredicted if parent chemical soil sorption values were used to predict transport. Copyright © 2006 Society of Chemical Industry
Cytochrome b gene structure and consequences for resistance to Qo inhibitor fungicides in plant pathogens
Authors: Grasso Valeria , Palermo Simona , Sierotzki Helge , Garibaldi Angelo , Gisi Ulrich 
Published: May 2006

AbstractThe cytochrome b (cyt b) gene structure was characterized for different agronomically important plant pathogens, such as Puccinia recondita f sp tritici (Erikss) CO Johnston, P graminis f sp tritici Erikss and Hennings, P striiformis f sp tritici Erikss, P coronata f sp avenae P Syd & Syd, P hordei GH Otth, P recondita f sp secalis Roberge, P sorghi Schwein, P horiana Henn, Uromyces appendiculatus (Pers) Unger, Phakopsora pachyrhizi Syd & P Syd, Hemileia vastatrix Berk & Broome, Alternaria solani Sorauer, A alternata (Fr) Keissl and Plasmopara viticola (Berk & Curt) Berlese & de Toni. The sequenced fragment included the two hot spot regions in which mutations conferring resistance to QoI fungicides may occur. The cyt b gene structure of these pathogens was compared with that of other species from public databases, including the strobilurin‐producing fungus Mycena galopoda (Pers) P Kumm, Saccharomyces cerevisiae Meyer ex Hansen, Venturia inaequalis (Cooke) Winter and Mycosphaerella fijiensis Morelet. In all rust species, as well as in A solani, resistance to QoI fungicides caused by the mutation G143A has never been reported. A type I intron was observed directly after the codon for glycine at position 143 in these species. This intron was absent in pathogens such as A alternata, Blumeria graminis (DC) Speer, Pyricularia grisea Sacc, Mycosphaerella graminicola (Fuckel) J Schröt, M fijiensis, V inaequalis and P viticola, in which resistance to QoI fungicides has occurred and the glycine is replaced by alanine at position 143 in the resistant genotype. The present authors predict that a nucleotide substitution in codon 143 would prevent splicing of the intron, leading to a deficient cytochrome b, which is lethal. As a consequence, the evolution of resistance to QoI fungicides based on G143A is not likely to evolve in pathogens carrying an intron directly after this codon. Copyright © 2006 Society of Chemical Industry
Structural and optical characterization of AlyInxGa1–x –yN quantum dots
Authors: Pérez‐Solórzano V. , Gröning A. , Schweizer H. , Jetter M. 
Published: May 2006

AbstractAly Inx Ga1–x –y N quantum dots have been grown by MOVPE on (0001) sapphire substrates. We investigated the dependence of the self‐assembled quantum dot density and height on the growth conditions: the growth temperature, the amount of deposited material, and the growth rate interruption. A maximum dot density of 4 × 1010 cm–2 was achieved. The optical properties were studied after overgrowing of the QDs with a GaN cap layer. We observed very intense luminescence in the region between 2.4 and 2.8 eV and decay times of 1.8 ns under resonant excitation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of a Mg‐doped GaN cap layer on the optical properties of InGaN/AlGaN multiple quantum well structures
Authors: Graham D. M. , Dawson P. , Zhang Y. , Costa P. M. F. J. , Kappers M. J. , Humphreys C. J. , Thrush E. J. 
Published: May 2006

AbstractWe have studied the effect of depositing a Mg‐doped GaN cap layer on near‐ultraviolet emitting In0.05Ga0.95N/Al0.05Ga0.95N multiple quantum well structures, using photoluminescence spectroscopy and transmission electron microscopy. The room temperature (T = 300 K) photoluminescence spectra revealed a reduction in the integrated photoluminescence intensity of the capped structure, which is shown by time decay measurements to be due to greater competition from non‐radiative recombination processes. The structural analysis of the samples using electron microscopy has not shown any evidence of Mg‐induced defects. We suggest that the non‐radiative recombination path is related to the diffusion of Mg atoms into the quantum well region and the formation of Mg‐nitrogen vacancy complexes. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Advanced buffers for AlGaN/GaN HEMT and InGaN/GaN MQW on silicon substrates
Authors: Dikme Y. , Fieger M. , Eickelkamp M. , Giesen C. , Lutsenko E. V. , Yablonskii G. P. , Szymakowski A. , Jessen F. O. , Vescan A. , Kalisch H. , Heuken M. , Jansen R. H. 
Published: May 2006

AbstractGaN growth was carried out on silicon (Si) substrates by metalorganic vapor phase epitaxy (MOVPE). A layer structure starting with HT (high‐temperature) AlN and containing AlGaN and GaN as interlayers was employed for the subsequent deposition of GaN buffer layers. At first, the influence of the in‐situ Al pre‐deposition at the process start with different durations was investigated. Each time, the pre‐deposition was followed by the same layer sequence and with thin AlGaN and GaN grown on top to form a high electron mobility transistor (HEMT). A significant enhancement could be observed in the properties of the investigated samples by reducing the pre‐deposition time from 8 s to 2 s. Based on these results, multiple quantum well structures (MQW) and HEMT were grown on these buffers. For the MQW, the well thickness was increased and a shift to higher wavelengths was observed. The HEMT structures have shown enhanced properties by optimizing the growth temperatures of the top AlGaN layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radiative recombination mechanism in highly modulation doped GaN/AlGaN multiple quantum wells
Authors: Arnaudov B. , Paskov P. P. , Haratizadeh H. , Holtz P. O. , Monemar B. , Kamiyama S. , Iwaya M. , Amano H. , Akasaki I. 
Published: May 2006

AbstractWe have studied the low‐temperature optical emission spectra in a set of GaN/AlGaN multiple quantum wells with heavily Si‐doped barriers. A careful analysis of the evolution of the emission lineshape with doping density suggests that the dominant recombination mechanism involves transitions between free two‐dimensional (2D) electrons and non‐equilibrium holes localized near the valence band edge. We propose a lineshape model, which is found to be in a good agreement with experimental spectra if the penetration of the barrier hole localization potential into the wells, the Burstein‐Moss effect, and the band‐gap renormalization are taken into account. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical cavity formation on GaN using a conventional RIE system
Authors: Kalaitzakis F. G. , Konstantinidis G. , Tsagaraki K. , Androulidaki M. , Pelekanos N. T. 
Published: May 2006

AbstractWe report on the fabrication of mirror‐like facets on GaN‐based laser structures, using a conventional RIE system and photoresist AZ 5214 as the etch mask. The roughness of the etched sidewalls is below 100 nm and the slope is practically vertical. For enhanced material protection during plasma etching, we describe an alternative lithography procedure with a double photoresist layer. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical spectra of (1‐101) InGaN/GaN and GaN/AlGaN MQW structure grown on a 7 degree off axis (001) Si substrate
Authors: Kim Eun‐Hee , Hikosaka Toshiki , Narita Tetsuo , Honda Yoshio , Sawaki Nobuhiko 
Published: May 2006

AbstractInGaN/GaN and GaN/AlGaN MQW waveguides were fabricated on a (1‐101) GaN facet grown on a 7‐degree off oriented (001) Si substrates by MOVPE. We achieved uniform layers with less dislocation density and superior flatness by virtue of the low growth rate on the facet. Using a nitrogen laser as the excitation source, the optical gain spectra as a waveguide was evaluated. In the InGaN/GaN MQW structure, we found that the optical gain was as high as +40 cm‐1 at near band edge emission peak. The GaN edge emission peak showed narrowing by high intensity excitation: the full width at half‐maximum 1.8nm at under 4.5 MW/cm2 at 77 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular beam epitaxy for high‐efficiency nitride optoelectronics
Authors: Heffernan J. , Kauer M. , Windle J. , Hooper S. E. , Bousquet V. , Zellweger C. , Barnes J. M. 
Published: May 2006

AbstractWe review the significant progress made in the development of nitride laser diodes by molecular beam epitaxy (MBE). We report on our recent result of room temperature continuous‐wave operation of InGaN quantum well laser diodes grown by MBE. Ridge waveguide lasers fabricated on freestanding GaN substrates have a continuous‐wave threshold current of 125 mA, corresponding to a threshold current density of 5.7 kA cm–2. The lasers have a threshold voltage of 8.6 V and a lifetime of several minutes. We outline the further technical challenges associated with demonstrating lifetimes of several thousand hours and present an assessment of the potential of MBE as a growth method for commercial quality nitride optoelectronic devices. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High and low energy proton irradiation effects on AlGaN/GaN HFETs
Authors: Sonia G. , Richter E. , Lossy R. , Mai M. , Schmidt J. , Weyers M. , Tränkle G. , Denker A. , Opitz‐Coutureau J. , Pensl G. , Brauer I. , Strunk H. P. 
Published: May 2006

AbstractAlGaN/GaN heterojunction field effect transistors (HFETs) have been irradiated with protons at 68 MeV and 2 MeV with fluences up to 1013 cm–2 in order to simulate operation in space. Hall effect measurements, dc characteristics and RF load pull measurements at 2 GHz do not reveal significant changes indicating the suitability of the transistors for reliable operation in space. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Identifying the most successful dose (MSD) in dose‐finding studies in cancer
Authors: Zohar Sarah , O'Quigley John 
Published: May 2006

AbstractFor a dose finding study in cancer, the most successful dose (MSD), among a group of available doses, is that dose at which the overall success rate is the highest. This rate is the product of the rate of seeing non‐toxicities together with the rate of tumor response. A successful dose finding trial in this context is one where we manage to identify the MSD in an efficient manner. In practice we may also need to consider algorithms for identifying the MSD which can incorporate certain restrictions, the most common restriction maintaining the estimated toxicity rate alone below some maximum rate. In this case the MSD may correspond to a different level than that for the unconstrained MSD and, in providing a final recommendation, it is important to underline that it is subject to the given constraint. We work with the approach described in O'Quigley et al. [Biometrics 2001; 57(4):1018–1029]. The focus of that work was dose finding in HIV where both information on toxicity and efficacy were almost immediately available. Recent cancer studies are beginning to fall under this same heading where, as before, toxicity can be quickly evaluated and, in addition, we can rely on biological markers or other measures of tumor response. Mindful of the particular context of cancer, our purpose here is to consider the methodology developed by O'Quigley et al. and its practical implementation. We also carry out a study on the doubly under‐parameterized model, developed by O'Quigley et al. but not actually studied in their paper. Copyright © 2006 John Wiley & Sons, Ltd.
The moderating role of development stage in free/open source software project performance
Authors: Stewart Katherine J. , Gosain Sanjay 
Published: May 2006

AbstractThe main thesis developed and tested in this article is that development stage plays an important moderating role in determining both objective and subjective performance outcomes in free/open source software (F/OSS) projects. This contention is supported by an empirical study of 67 F/OSS projects, with results indicating that subjective performance assessments are calibrated to different objective performance indicators across early and later development stages. The role of team climate variables (trust and shared ideology) in determining both objective and subjective performance also varies across stages. The findings have implications for improving software development processes through appropriate human resource management interventions over the course of F/OSS software projects. Copyright © 2006 John Wiley & Sons, Ltd.