bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron Transfer in Supercritical Carbon Dioxide: Ultraexothermic Charge Recombination at the End of the “Inverted Region”
Authors: Serpa Carlos , Gomes Paulo J. S. , Arnaut Luis G. , Formosinho Sebastião J. , Pina João , de Melo J. Seixas 
Published: March 2006

AbstractCharge‐recombination rates in contact radical‐ion pairs, formed between aromatic hydrocarbons and nitriles in supercritical CO2 and heptane, decrease with the exothermicity of the reactions until they reach −70 kcal mol−1, but from there on an increase is observed. The first decrease in rate is typical of the “inverted region” of electron‐transfer reactions. The change to an increase in the rate for ultra‐exothermic electron transfer indicates a new free‐energy relationship. We show that the resulting “double‐inverted region” is not due to a change in mechanism. It is an intrinsic property of electron‐transfer reactions, and it is due to the increase of the reorganisation energy with the reaction exothermicity.
π‐Conjugated Chelating Polymers with Charged Iridium Complexes in the Backbones: Synthesis, Characterization, Energy Transfer, and Electrochemical Properties
Authors: Liu Shu‐Juan , Zhao Qiang , Chen Run‐Feng , Deng Yun , Fan Qu‐Li , Li Fu‐You , Wang Lian‐Hui , Huang Chun‐Hui , Huang Wei 
Published: March 2006

AbstractA series of π‐conjugated chelating polymers with charged iridium (Ir) complexes in the backbones were synthesized by a Suzuki polycondensation reaction, leading to homogeneous polymeric materials that phosphoresce red light. The fluorene and bipyridine (bpy) segments were used as polymer backbones. 5,5′‐Dibromobipyridine served as a ligand to form a charged iridium complex monomer with 1‐(9′9‐dioctylfluorene‐2‐yl)isoquinoline (Fiq) as the cyclometalated ligand. Chemical and photophysical characterization confirmed that Ir complexes were incorporated into the backbones as one of the repeat units by means of the 5,5′‐dibromobipyridine ligand. Chelating polymers showed almost complete energy transfer from the host fluorene segments to the guest Ir complexes in the solid state when the feed ratio was 2 mol %. In the films of the corresponding blend system, however, energy transfer was not complete even when the content of Ir complexes was as high as 16 mol %. Both intra‐ and intermolecular energy‐transfer processes existed in this host–guest system, and the intramolecular energy transfer was a more efficient process. All chelating polymers displayed good thermal stability, redox reversibility, and film formation. These chelating polymers also showed more efficient energy transfer than the corresponding blended system and the mechanism of incorporation of the charged Ir complexes into the π‐conjugated polymer backbones efficiently avoided the intrinsic problems associated with the blend system, thus offering promise in optoelectronic applications.
Regio‐ and Diastereoselective Synthesis of Bis‐ and Tetrakisadducts of C70 by Directed Remote Functionalization Using Tröger Base Tethers
Authors: Wong Wallace W. H. , Diederich François 
Published: March 2006

AbstractDouble Bingel cyclopropanation of C70 with bismalonates featuring Tröger base derivatives as chiral spacers afforded bisadducts with almost perfect regio‐ and stereoselectivity. The excellent directing property of these rigidly folded spacers in the remote functionalization of the higher fullerene was further highlighted by the selective formation of a product with a novel bisaddition pattern involving the C(7)C(22) and C(33)C(34) bonds of C70. Enantiomerically pure bisadducts of C70 were prepared by highly diastereoselective transformations of bismalonates incorporating optically pure Tröger base tethers. The absolute configuration of these bisadducts was established by comparison of circular dichroism (CD) spectra with data reported in the literature. For the first time, optically active tetrakisadducts of a fullerene were prepared by two sequential chiral‐spacer‐controlled remote functionalizations.
Hydrogen‐Bonded Self‐Assembly of Pyridinium and Anilinium Bisphenols Mediated by the Hydrogen Difluoride Ion: Towards Control of CH⋅⋅⋅π (Aromatic) Interactions
Authors: Sarma Rupam J. , Baruah Jubaraj B. 
Published: March 2006

AbstractThe role of CH⋅⋅⋅π and CH⋅⋅⋅O interactions in HF2−‐assisted self‐assembly of nitrogen‐containing bisphenols are investigated. Unusual control on the end–face and edge–face geometries of aromatic CH⋅⋅⋅π interactions by a water molecule in the 4‐[(4‐hydroxy‐3,5‐dimethylphenyl)methyl]pyridinium difluoride lattice is observed. The bis(4‐hydroxy‐3,5‐dimethylphenyl)(4‐ammoniophenyl)methane⋅HF2− self‐assembles through the formation of hydrogen‐bonded cyclic hexamers.
Efficient Synthesis of a Chiral [4]Pseudocatenane and Its Derivatives: A Novel Ship's Wheel‐like Interlocked Structure
Authors: Zhu Xiao‐Zhang , Chen Chuan‐Feng 
Published: March 2006

AbstractA novel chiral[4]pseudocatenane 5H3[PF6]3 was synthesized efficiently by treatment of a solution of chiral triptycene‐based tri(crown ether) 1 and three equivalents of a bis[p‐(but‐3‐enyloxy)benzyl]ammonium salt in CH2Cl2 with a Grubbs II catalyst, followed by hydrogenation. It was found that the ammonium groups in 5H3[PF6]3 could be deprotonated by 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in acetonitrile or dimethyl sulfoxide (DMSO). Consequently, N‐acylation of the ammonium groups was easily performed in the presence of DBU, which resulted in a new class of neutral highly ordered interlocked molecules in good yields. In particular, the incorporation of stopper units, for example, diethyl phosphoramidate, lead to the isolation of the interlocked molecule 10 with an interesting ship's wheel‐like structure, which was structurally studied with the help of detailed NMR experiments. Compared with 1, it was further found that the Cotton effect of (R)‐1,1′‐binaphthyl chromophore at 241 nm was greatly reduced in 5H3[PF6]3 and its derivatives. Moreover, a new positive Cotton effect at 248 nm appeared in the interlocked molecules; this observation could be attributed to the chirality transfer from the binaphthyl units to the macrocycles lying in the cavities of 1.
Knockout of KASIII regulation changes fatty acid composition in canola (Brassica napus)
Authors: Stoll Christof , Lühs Wilfried , Zarhloul M. Karim , Brummel Monika , Spener Friedrich , Friedt Wolfgang 
Published: March 2006

AbstractIn contrast to the dominating unsaturated C18 fatty acid, medium‐chain fatty acids (MCFA) are nearly absent in the oil of common canola. Modification of canola oil towards higher contents of C8 to C14 fatty acids would create new possibilities for oleo‐chemical usages, in both the nutritional and the non‐food sectors. For this purpose, spring oilseed rape (cv. ‘Drakkar’) was genetically modified by introduction of MCFA‐encoding genes from Cuphea species containing approximately 90% MCFA in their seed oil. Two different single constructs involving the 3‐ketoacyl‐acyl carrier protein synthase (KAS)III from C. lanceolata were used, one harbouring the wild‐type gene, ClKASIIIbwt, and the other containing the point‐mutated gene, ClKASIIIbmut, along with two double constructs containing ClKASIIIbmut in combination with a medium‐chain thioesterase gene from C. lanceolata (ClFatB3) or C. hookeriana (ChFatB2). For both single‐gene constructs, a phenotype with an increased content of MCFA was not detected; however, the ClKASIIIbwt transformants produced up to 6.7% palmitic acid (C16). In T2 seeds bearing the ClKASIIIbmut/ClFatB3 double‐gene construct, contents of up to 2.9% capric (C10) and 11.4% palmitic acid were achieved. The best transformant with the gene construct ClKASIIIbmut/ChFatB2 contained 1.4% caprylic acid (C8) and 7.9% C10, and these results were confirmed in T3 seeds.
Alterations of the mitochondrial proteome caused by the absence of mitochondrial DNA: A proteomic view
Authors: Chevallet Mireille , Lescuyer Pierre , Diemer Hélène , van Dorsselaer Alain , Leize‐Wagner Emmanuelle , Rabilloud Thierry 
Published: March 2006

AbstractThe proper functioning of mitochondria requires that both the mitochondrial and the nuclear genome are functional. To investigate the importance of the mitochondrial genome, which encodes only 13 subunits of the respiratory complexes, the mitochondrial rRNAs and a few tRNAs, we performed a comparative study on the 143B cell line and on its Rho‐0 counterpart, i.e., devoid of mitochondrial DNA. Quantitative differences were found, of course in the respiratory complexes subunits, but also in the mitochondrial translation apparatus, mainly mitochondrial ribosomal proteins, and in the ion and protein import system, i.e., including membrane proteins. Various mitochondrial metabolic processes were also altered, especially electron transfer proteins and some dehydrogenases, but quite often on a few proteins for each pathway. This study also showed variations in some hypothetical or poorly characterized proteins, suggesting a mitochondrial localization for these proteins. Examples include a stomatin‐like protein and a protein sharing homologies with bacterial proteins implicated in tyrosine catabolism. Proteins involved in apoptosis control are also found modulated in Rho‐0 mitochondria.
A proteomic approach to investigate potential biomarkers directed against membrane‐associated breast cancer proteins
Authors: Canelle Ludovic , Bousquet Jordane , Pionneau Cedric , Hardouin Julie , Choquet‐Kastylevsky Genevieve , Joubert‐Caron Raymonde , Caron Michel 
Published: March 2006

AbstractThe identification of specific protein markers for breast cancer would provide the basis for early diagnosis. Particularly, membrane and membrane‐associated proteins are rich in targets for antibodies that may constitute suitable biomarkers of carcinogenesis. However, membrane proteins separation using 2‐DE remains difficult. In this work, the breast cancer cell line MCF7 was used as source of proteins for the screening of potential cell membrane‐associated antigens recognized by autoantibodies in patients with breast cancer and healthy volunteers. The protein extract obtained using trifluoroethanol (TFE) as cosolvent was compared to a total cell lysate protein extract prepared by a current technique. After 2‐DE separation of the two extracts, their protein patterns clearly differed. About 63% of the proteins identified in the TFE‐extract were predicted to possess at least one transmembrane domain. 2‐D blots probed with sera from cancer patients or from healthy volunteers showed that, as expected, additional antigens were provided in the TFE‐extract. Thus, the method described here appeared well suited for proteomic investigation of potential biomarkers undetected by current techniques.
Improving sensitivity of electrophoretic heteroduplex analysis using nucleosides as additives: Application to the breast cancer predisposition gene BRCA2
Authors: Weber Jérémie , Looten Rachelle , Houdayer Claude , Stoppa‐Lyonnet Dominique , Viovy Jean‐Louis 
Published: March 2006

AbstractA new method for the detection of unknown mutations, enhanced mismatch mutation analysis (EMMA), is proposed. It is based on electrophoretic heteroduplex analysis (HDA). The resolution is considerably improved, thanks to the combination of high‐resolution block‐copolymer sieving matrix, and nucleosides as additives in the electrophoretic medium. The EMMA method is compared to denaturing HPLC (DHPLC) in a large‐scale study of mutations in the breast cancer‐associated gene BRCA2, involving 4655 DNA amplicons from 94 patients. The rate of false positives was 0.09%. The raw success rate, without optimization of the amplicons tiling, was 94%, a value much higher than that achieved earlier with HDA, and comparable with that obtained with DHPLC. An analysis of the missed mutations suggest that the success rate could be improved up to about 97%, simply by redesigning the amplicons, while retaining the speed, cost effectiveness, and simplicity of the method.
Protein tryptic digests analyzed by carrier ampholyte‐based capillary electrophoresis coupled to ESI‐MS
Authors: Busnel Jean‐Marc , Descroix Stéphanie , Le Saux Thomas , Terabe Shigeru , Hennion Marie‐Claire , Peltre Gabriel 
Published: March 2006

AbstractIn this study, narrow pH cuts of carrier ampholytes have been used as buffers in CE for the analysis of protein tryptic digests. Their low conductivity allows very efficient separations under high electric field strength without inducing any significant Joule heating. In this study, the capabilities of narrow pH cuts of carrier ampholytes for the separation of protein tryptic digests have been assessed. Three proteins of different molecular masses have been studied: cytochrome C (horse heart), β‐lactoglobulin B (bovine) and human transferrin. Efficient, rapid and repeatable separations of the peptides resulting from the tryptic digestion have been achieved in this buffer. Moreover, the feasibility of the coupling of carrier ampholyte‐based capillary electrophoresis with ESI‐MS has been demonstrated through the study of the cytochrome C tryptic digest.
Immobilization of phospholipid‐avidin on fused‐silica capillaries for chiral separation in open‐tubular capillary electrochromatography
Authors: Han Nan‐Yin , Hautala Jari T. , Bo Tao , Wiedmer Susanne K. , Riekkola Marja‐Liisa 
Published: March 2006

AbstractPhospholipid‐coated fused‐silica capillaries with immobilized avidin were applied in the chiral separation of D,L‐tryptophan, D,L‐PTH‐serine, and D,L‐PTH‐threonine at pH 7.4 by open‐tubular CEC. Liposomes prepared from 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphocholine, 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐(Cap biotinyl), or 1,2‐dipalmitoyl‐sn‐glycero‐3‐phosphoethanolamine‐N‐(Biotinyl) with different amounts of phosphatidylserine were assessed as phospholipid coating materials. The stability of the coating and the success of the coating procedure were evaluated in terms of the repeatability of the enantiomer migration times and the resolution of enantiomers. The coating procedure itself significantly affected the migration times and resolution of the enantiomers. Reliable chiral separations with high separation efficiencies were achieved through careful choice of the coating method.
Kernel estimates of hazard functions for carcinoma data sets
Authors: Horová Ivana , Zelinka Jiří , Budíková Marie 
Published: March 2006

AbstractThe present article focuses on kernel estimates of hazard functions and their derivatives. Our approach is based on the model introduced by Müller and Wang (1990). In order to estimate the hazard function in an effective manner an automatic procedure in a paper by Horová et al. (2002) is applied. The procedure chooses a bandwidth, a kernel and an order of a kernel. As a by‐product we propose a special procedure for the estimation of the optimal bandwidth. This is applied to the carcinoma data sets kindly provided by the Masaryk Memorial Cancer Institute in Brno. Attention is also paid to the points of the most rapid change of the hazard function. Copyright © 2006 John Wiley & Sons, Ltd.
Stream health index for the Puget Sound Lowland
Authors: Chiu Grace , Guttorp Peter 
Published: March 2006

AbstractStream health is often measured by the multimetric benthic index of biotic integrity (B‐IBI). For Puget Sound Lowland (PSL) streams, the B‐IBI comprises ten metrics which quantify the well‐being of benthic inhabitants of the stream. Each metric is converted to a score of 1, 3 or 5, where a higher value indicates a healthier stream with respect to the metric. Summing the metric scores yields the B‐IBI. Stream health is then rated as very poor, poor, fair, good or excellent according to the index value.Different metrics may be measured on different scales. A scoring scheme is therefore required to standardize values across metrics. Conventional scoring for the B‐IBI metrics requires subjective and space/time‐dependent input on the cutoff points for discretizing each metric. In contrast, simple statistical standardization (centering and division by the standard deviation) appears to be more natural, is non‐study‐specific, and maps the metric space onto a continuous scale centered at 0. Comprising the same ten metrics of the PSL B‐IBI, our stream health index for the Puget Sound Lowland (SHIPSL) is the sum of all statistically standardized scores. We use benthic taxonomy data on field samples from 1997 to develop a SHIPSL‐based rating scheme of grades A to F for stream health. We also discuss an alternative version of SHIPSL defined using ‘gold‐standard’ values.Bootstrap simulations are used to compare the performance of the two versions of SHIPSL to B‐IBI in reflecting PSL stream health. Results show that both versions of SHIPSL are more efficient in measuring stream health. Without sacrificing information on underlying biological conditions, SHIPSL reduce bias and variability of the health index, and eliminates sensitivity of the rating to slight changes in the metric scoring scheme. Copyright © 2006 John Wiley & Sons, Ltd.
A resampling technique for estimating the power of non‐parametric trend tests
Authors: Nordgaard Anders , Grimvall Anders 
Published: March 2006

AbstractThe power of Mann–Kendall tests and other non‐parametric trend tests is normally estimated by performing Monte Carlo simulations in which artificial data are generated according to simple parametric models. Here we introduce a resampling technique for power assessments that can be fully automated and accommodate almost any variation in the collected time series data. A rank regression model is employed to extract error terms representing irregular variation in data that are collected over several seasons and may contain a non‐linear trend. Thereafter, an autoregressive moving average (ARMA) bootstrap method is used to generate new time series of error terms for power simulations. A study of water quality data from two Swedish rivers illustrates how our method can provide site‐ and variable‐specific information about the power of the Hirsch and Slack test for monotonic trends. In particular, we show how to clarify the impact of sampling frequency on the power of the trend tests. Copyright © 2006 John Wiley & Sons, Ltd.
Making environment statistics useful: a Third World perspective
Authors: Polfeldt Thomas 
Published: March 2006

AbstractOn a background of the growth of environmental awareness in developing countries, the data situation is briefly discussed, and the development of environment statistics is traced. It is argued that these statistics must be seen to be useful, and that vital steps to achieve this is through detailed analysis of environmental policies, training in environmental subjects and increased dialogue between users and producers. Copyright © 2006 John Wiley & Sons, Ltd.
Power comparison of generalizations of the mean test for affected sib pairs in case of incompletely informative markers
Authors: Knapp Michael 
Published: March 2006

AbstractPreviously applied test statistics for affected sib pairs (ASP) have been criticized for not fully exploiting the power of a given sample, because they do not account for incomplete informativity of an affected sib pair. To circumvent this problem, recently a new test had been proposed which weighs families proportional to their marker informativity. Here, the behavior of this new test is explored under scenarios considered to be relevant in the context of complex diseases. The results show that the new test does not represent an improvement. The asymptotic version of the new test tends to be markedly anti‐conservative even for larger sample sizes, whereas the permutation procedure proposed for the simulation of exact P values is at least questionable. Most importantly, the new test is less powerful than its competitors, especially in case of low marker informativity it was designed for. Genet. Epidemiol. 30: 2006. © 2006 Wiley‐Liss, Inc.
Energy density analysis of cluster size dependence of surface–molecule interactions (II): Formate adsorption onto a Cu(111) surface
Authors: Nakai Hiromi , Kikuchi Yasuaki 
Published: March 2006

AbstractAdsorption of formate (HCOO) onto a Cu(111) surface has been treated theoretically using 18 kinds of Cun (6 ≤ n ≤ 56) clusters. The energy density analysis (EDA) proposed by Nakai has been adopted to examine surface–molecule interactions for different cluster sizes. EDA results for the largest model cluster Cu56 have shown that the adsorption‐induced energy density variation in Cu atoms decays with distance from the adsorption site. Analysis of this decay, which can be carried out using the EDA technique, is important because it enables verification of the reliability of the model cluster used. In the case of formate adsorption onto the Cu(111) surface, it is found that at least a four‐layer model cluster is necessary to treat the surface–molecule interaction with chemical accuracy. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 917–925, 2006
Subcutaneous angioleiomyomas: Gray‐scale and color Doppler sonographic appearances
Authors: Gomez‐Dermit Vanesa , Gallardo E. , Landeras R. , Echevarría Fernández , Barredo R. García 
Published: March 2006

AbstractPurpose:To describe the gray‐scale Doppler and sonographic features of a series of subcutaneous angioleiomyomas.Methods:The sonographic appearances of 10 pathologically proven angioleiomyomas were retrospectively reviewed; 4 in women and 6 in men, with an age range from 33 to 77 years. We evaluated size, shape, echo pattern, margins, location, relationships with adjacent structures, and vascularity. Examinations were performed using a multifrequency linear array transducer (9–11 MHz) connected to a Logiq 500 scanner (GE, Milwaukee, Wl).Results:All tumors were subcutaneous and located in the extremities (7 in the lower extremities, 3 in the upper extremities). The sizes ranged from 0.6 to 6.4 cm, with an average size of 2 cm. All of the lesions were hypoechoic with well‐defined margins, and 9 were oval. Intratumoral calcifications were observed in two patients. Vascularity was easily detected in all of them, and 4 tumors had a clear vascular pedicle. The spectral Doppler analysis performed in 5 cases, revealing a low‐resistance arterial waveform in 4 patients.Conclusions:Although angioleiomyomas are uncommon soft tissue tumors, the presence of a well‐defined, hypoechoic, vascular subcutaneous tumor in the extremities should raise the possibility of such a diagnosis. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 34:50–54, 2006
Hemodynamic effects of subclavian steal phenomenon on contralateral vertebral artery
Authors: Tan Teng‐Yeow , Schminke Ulf , Chen Ting‐Yao 
Published: March 2006

AbstractPurpose:Increased blood flow velocity in the contralateral vertebral artery (VA) is a common finding in subclavian steal syndrome, but its clinical relevance is not known. The aim of this study was to investigate whether the degree of velocity increase in the contralateral VA correlated with the severity of the steal.Methods:In a retrospective study of 62 patients with subclavian steal phenomenon and 62 sex‐ and age‐matched controls, we analyzed the peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) of the Doppler spectrum of the VA contralateral to the subclavian steal phenomenon. Clinical information including sex, age, comorbidities and Doppler data were recorded from the sonography registration form.Results:In patients with subclavian steal syndrome, Doppler spectral analysis showed a complete reversal of flow in the VA in 29 patients (group A) and an alternating flow in 33 patients (group B). The PSV, MV, RI, and PI of the contralateral VA of patients from both groups were higher than in controls (p < 0.01 for both comparisons). The PSV, EDV, and MV in the contralateral VA were higher in patients with reversed flow compared with those with alternating flow (p < 0.05). Comparisons of clinical symptoms and comorbidities between the two groups did not yield significant findings.Conclusions:The degree of flow velocity increase in the contralateral VA artery correlates well with the severity of subclavian steal phenomenon. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 34:77–81, 2006