bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transparent solar cells based on dye‐sensitized nanocrystalline semiconductors
Authors: Park Nam‐Gyu , Kim Kyungkon 
Published: May 2008

AbstractLow‐cost dye‐sensitized solar cells have attracted much attention because of their unique characteristics of transparency and various colors. A dye‐sensitized solar cell is composed of a dye‐coated nanocrystalline wide‐bandgap semiconductor, redox electrolyte and platinum counter‐electrode. Transparency and various colors are attributed to a 10–20 μm thick semiconductor film with particle size of about 10–20 nm and a difference in HOMO–LUMO energies of the dye molecules, respectively. A biomimetic working principle enables effective electron injection and regeneration. Recent research on dye‐sensitized solar cells has been focused on the improvement of solar‐to‐electricity conversion efficiency as well as long‐term stability. In this report, the recent advances of transparent solar cells based on dye‐sensitized semiconductors are reviewed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Oxidative conversion of C1–C3 alkanes by vanadium oxide catalysts. DFT results and their accuracy
Authors: Rozanska Xavier , Sauer Joachim 
Published: May 2008

AbstractElementary steps in the oxidative conversion of methane, ethane, and propane by supported vanadium oxide species are studied by density functional theory, specifically B3LYP. Two models are adopted, namely OV(OH)3 and OVSi7O12H7, which yield similar energy profiles. The initial and rate‐determining step is hydrogen abstraction. Within the C1–C3 series, energy barriers and reaction energies follow the same trend as the CH bond strength in the different alkanes. For methane, only methanol formation is possible whereas for ethane and propane, oxidative dehydrogenation yields the corresponding alkenes. Single point CCSD(T)/TZVP calculations are used to assess the B3LYP error. For the barrier of the initial hydrogen abstraction the B3LYP error is larger than usual, −40 to −60 kJ/mol. With the non‐hybrid BP86 and PBE functionals even larger errors occur and the potential energy surface is qualitatively different. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Characterization of fifty‐one flavonoids in a Chinese herbal prescription Longdan Xiegan Decoction by high‐performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry and photodiode array detection
Authors: Wang Yun , Yang Li , He Yu‐Qi , Wang Chang‐Hong , Welbeck Ed W. , Bligh S. W. Annie , Wang Zheng‐Tao 
Published: May 2008

AbstractHigh‐performance liquid chromatography coupled to electrospray ionization (ESI) tandem mass spectrometry and photodiode array detection (HPLC‐DAD‐ESI‐MSn) was developed to identify and characterize the flavonoids in a Chinese formulated preparation, Longdan Xiegan Decoction (LXD). In total, fifty‐one flavonoids (27 flavones, 10 flavanones, 7 chalcones, 5 flavonols and 2 isoflavones) were characterized. Eighteen compounds among them including a newly detected flavonoid, naringin, from the ingredient herbs, were unambiguously determined by comparing the retention times (tR), UV spectral data and mass fragmentation behaviors with those of the reference compounds. Another thirty‐three compounds were tentatively identified by referencing to the reported data of their UV and MS spectra. The ESI‐MS/MS fragmentation behavior of flavones (OMe‐substituted, O‐glycosides, C‐glycosides), chalcones, flavonols and their appropriate characteristic pathways were proposed. In negative ion ESI‐MS all the flavonoids yielded prominent [MH]− ions in the first order mass spectra. Fragmentation with a loss of mass of 15 Da (CH3), 18 Da (H2O), 28 Da (CO), 44 Da (CO2), 56 Da (2CO) and the residues of glucose and glucuronic acid observed in the MS/MS spectra were useful for aiding the structural identification of the flavonoids investigated. Copyright © 2008 John Wiley & Sons, Ltd.
Determination of iodoacetic acid using liquid chromatography/electrospray tandem mass spectrometry
Authors: Lau Benjamin P.‐Y. , Becalski Adam 
Published: May 2008

AbstractA rapid analytical method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) using electrospray ionization in negative ion detection mode was developed for the analysis of underivatized iodoacetic acid in water. The method was applied to model reaction mixtures in the study of the formation of iodoacetic acid after chlorinated tap water was boiled in the presence of potassium iodide or iodized table salt. Samples can be directly analyzed by the LC/MS/MS system without extraction or chemical derivatization. Limit of detection was determined to be 0.3 µg/L (or 0.3 ng/mL) and limit of quantitation was about 1 µg/L (1 ng/mL). Copyright © 2008 John Wiley & Sons, Ltd.
Lys Tag: an easy and robust chemical modification for improved de novo sequencing with a matrix‐assisted laser desorption/ionization tandem time‐of‐flight mass spectrometer
Authors: Conrotto Paolo , Hellman Ulf 
Published: May 2008

AbstractMass spectrometry using a matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight (TOF) instrument is a widespread technique for various types of proteomic analysis. Along with an expanding interest in proteomics, there is a strong requirement for the identification of proteins with high confidence from biological samples. Peptide modification by a wide variety of post‐translational modifications (PTMs), the existence of different protein isoforms and the presence of uncharacterized genomes of many species, make protein identification through peptide mass fingerprinting (PMF) often unachievable. Peptide de novo sequencing has been proven to be a useful approach to overcome these variables, and efficient derivatization processes are important tools to achieve this goal. In the present work we describe the methodology and experimental applications of a fast, efficient and cheap lysine derivatization. This chemical modification improves the signals from lysine‐terminated peptides and can be efficiently used as a lysine‐blocking agent in combination with other derivatization techniques. Most importantly, upon peptide fragmentation it generates a neat series of predominantly y‐ions, allowing the determination of unambiguous amino acid sequences. Moreover, this chemical compound was used with target‐eluted samples, enabling a second, alternative analysis of the same sample in the MALDI mass spectrometer. Copyright © 2008 John Wiley & Sons, Ltd.
Metabolomic profiling using Orbitrap Fourier transform mass spectrometry with hydrophilic interaction chromatography: a method with wide applicability to analysis of biomolecules
Authors: Kamleh A. , Barrett M. P. , Wildridge D. , Burchmore R. J. S. , Scheltema R. A. , Watson D. G. 
Published: May 2008

AbstractIt was shown that coupling hydrophilic interaction chromatography (HILIC) to Orbitrap Fourier transform mass spectrometery (FT‐MS) provided an excellent tool for metabolic profiling, principally due to rapid elution of lipids in advance of most metabolites entering the mass spectrometer. We used in vitro cultivated procyclic forms of the protozoan parasite Trypanosoma brucei as a source of metabolites to test the performance of the HILIC column and the mass accuracy of MS. The mass accuracy achieved fell within 2 ppm for all the metabolites identified within samples. It was, for example, possible to identify the signature metabolite of the trypanosome, trypanothione, and also glutathione which were well retained by the HILIC column. By comparing trypanosomes grown in two different media we were able to clearly distinguish the samples in terms of the relative abundance of a number of metabolites using Sieve 1.1 software. Copyright © 2008 John Wiley & Sons, Ltd.
Prioritizing removal of dams for passage of diadromous fishes on a major river system
Authors: Kocovsky Patrick M. , Ross Robert M. , Dropkin David S. 
Published: May 2008

AbstractNative diadromous fishes have been extirpated from much of the Susquehanna River system for nearly a century. Recent restoration efforts have focused on removal of dams, but there are hundreds of dams and presently there is no biologically based system to assist in prioritizing their removal. We present a new method that uses existing habitat suitability index models (HSI) for American shad Alosa sapidissima, alewife A. pseudoharengus, blueback herring A. aestivalis, and American eel Anguilla rostrata to prioritize the removal of non‐hydropower dams within the Susquehanna River system. We ranked HSI scores for each of the four species, association between a landscape‐scale factor and HSIs, length of river opened by removing a dam, and distance from the mouth at Chesapeake Bay for each dam and then calculated a mean rank prioritization for dam removal by averaging the ranks for the seven criteria. This prioritization method is resistant to outliers, is not strongly affected by somewhat arbitrary decisions on metrics included in the analysis, and provides a biologically based prioritization for dam removal that can be easily amended to include other metrics or adapted to other river systems and that complements other social and economic considerations that must be included in decisions to remove dams. Published in 2008 by John Wiley & Sons, Ltd.
Effects of artificial woody structures on Atlantic salmon habitat and populations in a Nova Scotia stream
Authors: Floyd Trevor A. , MacInnis Charles , Taylor Barry R. 
Published: May 2008

AbstractA 1‐km reach of Brierly Brook, Nova Scotia, was studied from 1995 to 2004 to determine if the addition of artificial structures mimicking large woody debris could enhance Atlantic salmon populations. In 1995, digger logs (which mimic fallen trees) and deflectors (which narrow the channel) were constructed in a 250‐m section of the brook devoid of woody debris (Old Restored Site). In 2003, 5 more digger logs and defectors were built in a previously unrestored section of the stream (New Restored Site). A third control site was left unchanged. Physical changes caused by the structures were monitored at the New Restored Site. Densities of juvenile and spawning Atlantic salmon were also monitored. At all sites, woody debris structures in the brook were important and effective in creating complex salmonid habitat. The structures narrowed the channel, scoured pools and undercut banks. They created habitat that parr used for summer and winter refuge and adult spawners used for cover and resting during upstream migration and spawning. The structures caused gravels to accumulate that spawning adults used to build redds and fry used for shelter. The reaches with structures had higher spawning densities than reaches without them; spawning increased in the New Restored Site relative to the control site. The absence of woody debris may be a bottleneck for salmonid populations in streams of the Atlantic Northeast. For streams with a small or immature riparian zone and little woody debris in the channel, woody structures may be an effective tool for restoring salmonid populations. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of flood regime on tree growth in the floodplain and surrounding uplands of the Wisconsin River
Authors: Predick Katharine I. , Gergel Sarah E. , Turner Monica G. 
Published: May 2008

AbstractFlood regime and vegetation flood tolerance interact to influence tree growth in riverine landscapes. We studied tree growth in floodplain and upland forests of the Wisconsin River. About a century ago, levees set back from the river were constructed on this floodplain. The levee restricts some floodplain area from overbank flood events, but leaves a portion of active floodplain still inundated by floods. We addressed two questions: (1) how do growth rates of flood‐tolerant and flood‐intolerant tree species in the floodplain differ with flood regime? (2) At the stand level, how does growth rate differ with flood regime and between floodplain and upland areas? Annual tree growth rates from 1991 to 2000 were determined from tree increment cores for both individual species and stands. Tree growth rates of individual species varied between flood regimes. The most flood‐tolerant species (Betula nigraandFraxinus pennsylvanica) grew faster in areas with active flooding, while the growth of less flood‐tolerant species (Quercus velutinaandQ. ellipsoidalis) was depressed in swales and active floodplain. However, stand‐level tree growth did not differ between the floodplain and upland, or between flood regimes within the floodplain. Therefore, variation in the growth of individual species may not scale up to create differences in stand‐level tree growth because forest community composition varies spatially with flood regime. We suggest that growth rates are similar among sites because each community comprises of species adapted to their current flood regime. Copyright © 2008 John Wiley & Sons, Ltd.
Reintroducing wood to streams in agricultural landscapes: changes in velocity profile, stage and erosion rates
Authors: Lester Rebecca Elaine , Wright Wendy 
Published: May 2008

AbstractHistorically, perceived increases in erosion and flooding levels have been attributed to in‐stream wood and used to justify its removal from streams and rivers around the world. More recently, recognition of the adverse morphological and biological impacts caused by this removal has led to rehabilitation projects that actively reintroduce wood to streams. However, a perception remains amongst some members of the general community that wood additions increase the likelihood of flooding and erosion in the target streams.To test whether there was a basis for this perception, we experimentally added wood to eight streams across southwest Victoria and Gippsland, Australia. The velocity, stage and bed and bank erosion rates were compared with those of unaltered reaches. We detected localized changes in the velocity and stage parameters but that these were unlikely to operate at the reach‐scale. Bed erosion rates, where maximum erosion was assumed if pins were not recovered, showed increased erosion due to wood additions but this was not supported by channel shape analyses, which identified short‐term increases in the variability of the channel shape, followed by longer‐term stability at treatment sites.We found no clear evidence of increased longer‐term rates of erosion or flooding associated with the introduction of wood to streams over the 18‐month study period. It remains important to carefully design rehabilitation works, but the lack of adverse effects on stream morphology and increased variability of the in‐stream environment suggests improved habitat diversity, supporting the use of wood addition as a stream rehabilitation technique. Copyright © 2008 John Wiley & Sons, Ltd.
Improving bio‐diagnostic monitoring using simple combinations of standard biotic indices
Authors: Clews Esther , Ormerod S. J. 
Published: May 2008

AbstractInvertebrate biotic indices are used widely to assess river quality. However, because reduced values can have many potential causes, general biotic indices have limited value in diagnosing reasons for impairment. Here, we investigate whether simple combinations of biotic indices can improve diagnostic capability.In the catchment of the Welsh River Wye, invertebrates varied significantly among groups of 55 streams in taxonomic composition and in index scores representing acidification (AWIC), mild eutrophication/organic pollution (BMWP/ASPT), and flow (LIFE). Although sites impacted by different forms of pollution tended to have reduced BMWP scores, acidified and enriched sites became distinguishable from each other, and from unimpaired streams, when classified on a combination of these indices. Combined indices also differentiated among competing explanations for trends in biological quality through time by revealing how increasing BMWP at some sites reflected local reductions in eutrophication.These data illustrate how simple univariate indices, calibrated to respond to specific pressures, have bio‐diagnostic capability when used together even in a relatively unpolluted catchment such at the Wye. In this Special Area of Conservation, they identified specific management needs in different locations—respectively to mitigate acidification in upland base‐poor tributaries and to reduce diffuse nutrients in the lower catchment. We advocate (i) the development of more pressure‐specific indices, for example to detect morphological modification, sedimentation and metal impacts; and (ii) further exploration of combined indices from one or more groups of organisms (e.g., diatoms and invertebrates) to increase bio‐diagnostic capability in river monitoring. Copyright © 2008 John Wiley & Sons, Ltd.
Estimating error rates in the classification of paired organs
Authors: Brenning Alexander , Lausen Berthold 
Published: May 2008

AbstractClinical data from paired organs present a dependence structure that has to be considered when making statistical inference or evaluating classification rules with resampling‐based techniques (bootstrap, cross‐validation). We introduce a paired cross‐validation approach for the estimation of misclassification error rates in the classification of data from paired organs. The dependence structure of the sample is honored by subject‐level cross‐validation. Theoretical considerations as well as a case–control study on glaucoma diagnosis and a simulation study show that the variance of the paired cross‐validation estimator is considerably lower than in traditional cross‐validation error estimation on one randomly selected eye per subject. The actual variance reduction is mainly controlled by the contribution of differential misclassification between both eyes to the overall error rate. By contrast, ‘ad hoc’ cross‐validation ignoring the autocorrelation of paired organs leads to biased error estimates. Using the double‐bagging technique, we also show that classification accuracy can be improved by using information from both eyes in training machine‐learning classifiers. In glaucoma detection, the reduction in misclassification error rates by training data from both eyes is equivalent to an increase in the sample size by one‐third to one‐half, which is an important achievement in clinical studies. Copyright © 2008 John Wiley & Sons, Ltd.
Energy management in buildings: A systems approach
Authors: Kouloura T.C. , Genikomsakis K.N. , Protopapas A.L. 
Published: May 2008

AbstractSystems approach is used to enhance the energy performance of an existing building by holistically examining it as a ‘‘sociotechnical’’ system. A student dormitory in the city of Xanthi, Greece, is used as a case study to identify the most appropriate interventions according to the principles of sustainability. In this context, a framework is developed that could be extensively used for energy management of existing buildings as well as of new ones. The ‘‘system methodology’’ of this framework breaks through the limited scope of engineering analysis and emerges as the only available tool to implement the principles of sustainability. © 2008 Wiley Periodicals, Inc.
Applications of a new portable (micro) XRF instrument having low‐Z elements determination capability in the field of works of art
Authors: Uhlir K. , Griesser M. , Buzanich G. , Wobrauschek P. , Streli C. , Wegrzynek D. , Markowicz A. , Chinea‐Cano E. 
Published: May 2008

AbstractX‐ray fluorescence analysis (XRF) is a powerful tool for nondestructive analysis of chemical elements present in art and archeological material. Nevertheless, investigations of objects possessing a glassy matrix still offer some problems using XRF because of the absorption in air of the low‐energy characteristic fluorescence radiation of light elements. With the design of a XRF instrument equipped with a vacuum chamber housing both, the x‐ray optics and the detector snout inside, a new attempt to solve this problem was made. The Conservation Science Department of the Kunsthistorisches Museum Vienna (KHM) had the opportunity to test this instrument on different objects of art. An overview of some results from these measurements, together with a short discussion of the experiences gained during the investigations, is presented in this article. Copyright © 2008 John Wiley & Sons, Ltd.
Safety of emulsifiers in fats and oils
Authors: Artman Neil R. 
Published: May 2008

AbstractConsumers have come to expect many foods that can be served with minimum effort. Such convenience foods frequently require the use of emulsifiers in their formulations. Emulsifiers enable fatty and aqueous phases to be combined. Various emulsifiers have been developed to meet specific needs and have been judged adequately safe for their intended uses. Safety evaluation programs may include both feeding studies and metabolic studies. Feeding studies establish the levels at which a compound can be fed to experimental animals with no detectable ill effects. From this information, it is possible to estimate quantities that may be consumed safely by humans. Metabolic studies tell how a compound is handled by the body—whether it is burned for energy, stored, or excreted. The choice of studies to use in evaluating a specific compound depends upon the chemical nature of the compound, its similarity to familiar materials, and its intended use. Studies carried out with polysorbates and with monoglycerides are reviewed to illustrate these points and to show how safety testing programs yield the information needed for making sound safety judgments.
Looking beyond the basal ganglia: The spectrum of MRI changes in methylmalonic acidaemia
Authors: Harting I. , Seitz A. , Geb S. , Zwickler T. , Porto L. , Lindner M. , Kölker S. , Hörster F. 
Published: May 2008

SummaryWe report imaging abnormalities from 5 brain MR examinations in 4 children with methylmalonic acidaemia between the ages of 20 days and 31 months. In addition to bilateral basal ganglia lesions (pallidum) observed in 3 of 4 children, we found signs of delayed brain maturation (myelination delay, immature gyral pattern, incomplete opercularization) in all children and signs of a white matter disorder in the 3 older children. Unexpectedly, brainstem and cerebellar changes were present in all children. Reviewing the brain imaging changes reported for methylmalonic acidaemia, we discuss the findings and patterns observed in our patients. We postulate that delayed myelination and signs of a white matter disorder as well as brainstem and cerebellar involvement are common findings and may be due to a chronic neurotoxic effect on the developing and ageing brain.
Baicalein 5,6,7‐trimethyl ether activates peroxisomal but not mitochondrial fatty acid β‐oxidation
Authors: Morita M. , Kanai M. , Mizuno S. , Iwashima M. , Hayashi T. , Shimozawa N. , Suzuki Y. , Imanaka T. 
Published: May 2008

SummaryRecently, we reported that baicalein 5,6,7‐trimethyl ether (BTM), a flavonoid, is capable of activating fatty acid β‐oxidation in X‐linked adrenoleukodystrophy (X‐ALD) fibroblasts (FEBS Lett. 2005; 579: 409–414). The objective of this study was to clarify whether BTM activates peroxisomal and/or mitochondrial fatty acid β‐oxidation. We first analysed the effect of BTM on fatty acid β‐oxidation in fibroblasts derived from healthy controls as well as patients with X‐ALD, mitochondrial carnitine‐acylcarnitine translocase (CACT) deficiency, and peroxisome biogenesis disorder, Zellweger syndrome. Lignoceric acid (C24:0) β‐oxidation in the fibroblasts was stimulated by treatment with BTM, except for Zellweger fibroblasts. In contrasts, palmitic acid (C16:0) β‐oxidation was increased (2.8‐fold) only in CACT‐deficient fibroblasts. In U87 glioblastoma cells, C24:0 β‐oxidation was also activated by treatment with BTM but C16:0 β‐oxidation was not. The C16:0 β‐oxidation was, however, significantly increased in the presence of 2‐[5‐(4‐chlorophenyl)pentyl]oxirane‐2‐carboxylate (POCA), a carnitine palmitoyltransferase I inhibitor. These results indicate that BTM activates peroxisomal but not mitochondrial fatty acid β‐oxidation. In addition, we found that BTM did not upregulate the expression of ABCD2/ALDR, ABCD3/PMP70, ACOX1 and FATP4 genes but slightly increased ACSVL1 gene expression.