bluuebunny/crossref_metadata_2025_split huggingface dataset:
Real‐time forecasting of photosmog episodes: the Naples case study
Authors: Riccio A. , Barone G. 
Published: January 2005

AbstractIn this paper we analysed the ozone time series data collected by the local monitoring network in the Naples urban area (southern Italy) during the spring/summer period of 1996. Our aim was to identify a reliable and effective model that could be used for the real‐time forecasting of photosmog episodes. We studied the applicability of seasonal autoregressive integrated moving average models with some exogenous variables (ARIMAX) to our case study. The choice of exogenous variables—temperature, [NO2]/[NO] ratio and wind speed—was based on physical reasoning. The forecasting performance of all models was evaluated with data not used in model development, by means of an array of statistical indices: the comparison between observed and forecast means and standard deviations; intercept and slope of a least squares regression of forecast variable on observed variable; mean absolute and root mean square errors; and 95% confidence limits of forecast variable. The assessment of all models was also based on their tendency to forecast critical episodes. It was found that the model using information from the temperature data set to predict peak ozone levels gives satisfactory results, about 70% of critical episodes being correctly predicted by the 24 h ahead forecast function. Copyright © 2001 John Wiley & Sons, Ltd.
PCR eigenvector selection based on correlation relative standard deviations
Authors: Fairchild Steven Z. , Kalivas John H. 
Published: January 2005

AbstractWhile principal component regression (PCR) is often performed with eigenvectors ordered by decreasing singular values, PCR models have been formed using other eigenvector arrangements. A common criterion for organizing eigenvectors involves absolute correlations between respective eigenvectors and the prediction property being modeled. However, correlation cut‐off values for eigenvector selection are inconsistent between data sets, and additional criteria are needed such as the root mean square error of cross‐validation (RMSECV). Furthermore, correlations for some selected eigenvectors are often extremely low (e.g. values of 0·1 have been considered acceptable) and it is difficult to justify inclusion of these eigenvectors. Relative standard deviations (RSDs) of correlations are evaluated in this paper as an alternative method of eigenvector selection. This paper reveals distinct advantages for using eigenvectors ordered by RSDs of correlations compared to eigenvectors ordered by absolute correlations. In particular, RSDs can be used to determine significant eigenvectors without resorting to additional criteria such as the RMSECV. Additionally, inspection of RSD values explains why different correlation cut‐off values are obtained for different data sets as well as why correlations can be small. Copyright © 2001 John Wiley & Sons, Ltd.
Multivalent Host–Guest Interactions between β‐Cyclodextrin Self‐Assembled Monolayers and Poly(isobutene‐alt‐maleic acid)s Modified with Hydrophobic Guest Moieties
Authors: Crespo‐Biel Olga , Péter Mária , Bruinink Christiaan M. , Ravoo Bart Jan , Reinhoudt David N. , Huskens Jurriaan 
Published: January 2005

AbstractPoly(isobutene‐alt‐maleic acid)s modified with p‐tert‐butylphenyl or adamantyl groups interact with β‐cyclodextrin self‐assembled monolayers (β‐CD SAMs) by inclusion of the hydrophobic substituents in the β‐cyclodextrin cavities. The adsorption was shown to be strong, specific, and irreversible. Even with a monovalent competitor in solution, adsorption to the β‐CD SAMs was observed, and desorption proved impossible. The adsorbed polymer layer was very thin as evidenced by surface plasmon resonance spectroscopy and AFM. Apparently, all or most hydrophobic groups of the polymers were employed efficiently in multivalent binding, as was further supported by the absence of specific binding of β‐CD‐modified gold nanoparticles to the polymer surface assemblies. Supramolecular microcontact printing of the polymers onto the β‐CD SAMs led to assembly formation in the targeted areas of the substrates.
CαC Backbone Fragmentation Dominates in Electron Detachment Dissociation of Gas‐Phase Polypeptide Polyanions
Authors: Kjeldsen Frank , Silivra Oleg A. , Ivonin Igor A. , Haselmann Kim F. , Gorshkov Mikhail , Zubarev Roman A. 
Published: January 2005

AbstractFragmentation of peptide polyanions by electron detachment dissociation (EDD) has been induced by electron irradiation of deprotonated polypeptides [M−nH]n− with >10 eV electrons. EDD has been found to lead preferentially to a. and x fragment ions (CαC backbone cleavage) arising from the dissociation of oxidized radical anions [M−nH](n−1)−.. We demonstrate that CαC cleavages, which are otherwise rarely observed in tandem mass spectrometry, can account for most of the backbone fragmentation, with even‐electron x fragments dominating over radical a. ions. Ab initio calculations at the B3 LYP level of theory with the 6‐311+G(2 p,2 d)//6‐31+G(d,p) basis set suggested a unidirectional mechanism for EDD (cleavage always N‐terminal to the radical site), with a., x formation being favored over a, x. fragmentation by 74.2 kJ mol−1. Thus, backbone CαC bonds N‐terminal to proline residues should be immune to EDD, in agreement with the observations. EDD may find application in mass spectrometry for such tasks as peptide sequencing and localization of labile post‐translational modifications, for example, those introduced by sulfation and phosphorylation. EDD can now be performed not only in Fourier transform mass spectrometry, but also in far more widely used quadrupole (Paul) ion traps.
Is It Possible To Get High TC Magnets with Prussian Blue Analogues? A Theoretical Prospect
Authors: Ruiz Eliseo , Rodríguez‐Fortea Antonio , Alvarez Santiago , Verdaguer Michel 
Published: January 2005

AbstractTheoretical methods based on density functional theory have been employed to search for Prussian blue analogues with Curie temperatures higher than the ones reached today. Our study suggests several possible cyano‐bridged compounds as candidates to present stronger exchange coupling and higher ordering temperatures than the well known CrIIIVII derivatives.
Stereoselective Allyl Amine Synthesis through Enantioselective Addition of Diethylzinc and [1,3]‐Chirality Transfer: Synthesis of Lentiginosine and Polyoxamic Acid Derivative
Authors: Ichikawa Yoshiyasu , Ito Takashi , Isobe Minoru 
Published: January 2005

AbstractA new synthetic method for the preparation of allyl amines has been developed. The key steps of this method are enantioselective addition of diethylzinc and [1,3]‐chirality transfer through the [3.3] sigmatropic rearrangement of allyl cyanates. Stereocontrolled syntheses of lentiginosine (1) and polyoxamic acid derivative 2 from a common intermediate 7 derived from D‐tartaric acid (8), have been accomplished.
Catalytic, Asymmetric Aza‐Baylis–Hillman Reaction of N‐Sulfonated Imines with Activated Olefins by Quinidine‐Derived Chiral Amines
Authors: Shi Min , Xu Yong‐Mei , Shi Yong‐Ling 
Published: January 2005

AbstractThe chiral nitrogen Lewis base, tricyclic cinchona alkaloid derivative TQO, is an effective promoter in the catalytic, asymmetric aza‐Baylis–Hillman reaction of N‐sulfonated imines ArCHNR′ 1 (R′ = Ts, Ms, Ns, SES) with various activated olefins such as methyl vinyl ketone (MVK), ethyl vinyl ketone (EVK), acrolein, methyl acrylate, phenyl acrylate, or α‐naphthyl acrylate to give the corresponding adducts in moderate to good yields with good to high ee (up to 99 %) at −30 °C or 45 °C in various solvents, including DMF/MeCN (1:1, v/v). The first such reaction of 1 with the simplest Michael acceptor MVK and methyl acrylate has been achieved with excellent enantioselectivity. The adducts derived from MVK and EVK had the opposite absolute configuration to those from acrolein, methyl acrylate, phenyl acrylate, and α‐naphthyl acrylate. A plausible mechanism has been proposed on the basis of previous reports and the authors’ investigations. An effective bifunctional chiral nitrogen Lewis base–Brønsted acid system has been revealed in this type of aza‐Baylis–Hillman reaction.
Resolution of Seven‐Coordinate Complexes
Authors: Lennartson Anders , Vestergren Marcus , Håkansson Mikael 
Published: January 2005

AbstractThe crystal structures of [Pr(dbm)3H2O] (1), [Sm(dbm)3H2O] (2), and [Er(dbm)3H2O] (3) have been determined (dbm=dibenzoylmethane). They display seven‐coordinate propeller‐shaped molecules, which are chiral and crystallize as conglomerates in space group R3. Analysis of the crystal structures reveals supramolecular interactions, including formation of a quadruple helix, which explain how stereochemical information can be transferred between stacks of molecules. A method to quantify the ee in bulk samples of stereochemically labile compounds by using solid‐state CD spectroscopy is described. Using this method, it has been shown that compounds 1–3 undergo total spontaneous resolution directly after synthesis, forming a microcrystalline reaction product that is essentially enantiopure. The resolution of bulk quantities of seven‐coordinate complexes (without chiral or polydentate ligands) is thus reported for the first time. Because the crystallization starts without seeding, the overall preparation may be regarded as absolute asymmetric synthesis.
Design and DNA Binding of an Extended Triple‐Stranded Metallo‐supramolecular Cylinder
Authors: Uerpmann Carsten , Malina Jaroslav , Pascu Mirela , Clarkson Guy J. , Moreno Virtudes , Rodger Alison , Grandas Anna , Hannon Michael J. 
Published: January 2005

AbstractA new tetracationic triple‐stranded supramolecular cylinder is prepared from a bis(pyridylimine) ligand containing a diphenylmethane and two ketimine groups in the spacer. The cylinder is longer and slightly wider than the corresponding cylinder containing just diphenylmethane spacers. Inter‐strand CH⋅⋅⋅π interactions are not observed and this affects the relay of the chiral information within the cylinder; a mixture ofracandmesoisomers results, with themesoisomer being the dominant solution species and characterised in the solid state by crystallography. This new cylinder does bind to DNA as confirmed by induced circular dichroism signals in both the metal‐to‐ligand charge transfer (MLCT) and in‐ligand bands of the cylinder. Flow linear dichroism demonstrates that the cylinder binds to DNA in a specific orientation(s) and is consistent with (major) groove‐binding as seen for the shorter cylinder. Some DNA bending/coiling is observed but the effect is much less dramatic than observed for the cylinder with diphenylmethane spacers confirming that coiling is not solely a consequence of the tetracationic charge, but rather is related to the precise size and shape of the cylinder.
Synthesis and Electrochemical Study of Novel Thiadiazolo‐Ferrocene Derivatives
Authors: Shang Yong‐Jia , Wu De‐Lin , Wang Yan‐Ling , Shen Liang‐Jun 
Published: January 2005

AbstractThree novel thiadiazolo‐ferrocence derivatives containing long chain alkyl group were synthesized and characterized. The voltammetric behaviour of these thiadaizolo‐ferrocene derivatives was studied on gold electrode (diameter 1 mm) in CH2Cl2/0.2 mol/L tetra‐n‐butylammonium hexafluorophosphate. The influence of β‐cyclodextrin on the voltammetric behaviour of the compounds was also studied.
Study on the Interaction between Pefloxacin Mesylate and Human Serum Albumin
Authors: Tan Fei , Wen Xian‐Hong , Guo Ming , Yi Shuai , Ma Guo‐Zheng , Yu Qing‐Sen 
Published: January 2005

AbstractThe binding characteristics of pefloxacin mesylate (PFLX) and human serum albumin (HSA) have been studied by fluorescence spectroscopy in aqueous solution, and the interaction influenced by copper(II) was also explored in the paper. The results show that the two reaction equilibrium constant and the number of binding sites were K=1.7×105 L·mol−1, n=1.05 for PFLX and K=1.61×105 L·mol−1, n=1.5 for PFLX‐Cu2+, respectively. The quenching mechanism of fluorescence of HSA by PFLX is a static quenching procedure. The binding distance between PFLX and HSA and the energy transfer efficiency were obtained based on the theory of Förster spectroscopy energy transfer. The effect of pefloxacin mesylate on the conformation of HSA has also been analyzed by using synchronous fluorescence spectroscopy. The interaction of PFLX and HSA have been studied by flow‐mixed microcalorimetry in the absence and presence of copper(II), and their thermodynamic parameters were obtained. The enthalpy change and the entropy change were calculated to be ΔH≈0, ΔS>0 in the absence of copper(II), indicating that hydrophobic forces played major role in the interaction between PFLX and HSA, and to be ΔH<0, ΔS>>0 in the presence of copper(II), indicated that the static forces played major role in the reaction. The molar free energy changes of the two reactions are identical with each other because the entropy‐enthalpy compensation happened between the two reactions.
Molecular Recognition of Chiral Zinc Porphyrin with Amino Acid Esters
Authors: Wang Shu‐Jun , Ruan Wen‐Juan , Zhao Xiao‐Jing , Luo Dai‐Bing , Zhu Zhi‐Ang 
Published: January 2005

AbstractOne kind of novel chiral porphyrin and its zinc complex were synthesized and characterized. The molecular recognition of chiral zinc porphyrin towards amino acid esters in CHCl3 was investigated by UV‐vis spectral titration method. The associative constants of the molecular recognition reactions were all KD>KL and followed the order of K(PheOMe)>K(LeuOMe)>K(ValOMe)>K(AlaOMe) in host (Zn(L‐BocTyr)TAPP). Circular dichroism spectra were used to explain chiral molecular recognition. The minimal energy conformation of host‐guest molecular system was sought by molecular dynamics method. The molecular recognition process of this host‐guest system was calculated by quantum chemistry and the results were explained by the experiments
Photoinduced Electron Transfer in Host‐Guest Complexes of 2‐Naphthyl‐(OCH2CH2)n‐adamantanamines with Mono‐6‐O‐p‐nitrobenzoyl‐β‐cyclodextrin and Mono‐6‐O‐m‐nitrobenzoyl‐β‐cyclodextrin
Authors: Wu Qi‐Hua , Zhu Man‐Zhou , Wei Su‐Jun , Liu Lei , Guo Qing‐Xiang 
Published: January 2005

AbstractA number of naphthalene donor compounds that possess an adamantanamine binding moiety and an (OCH2CH2)n (n=1, 2, 3, 4, 6, 8) spacer were synthesized. The fluorescence quenching between these donor substrates and mono‐6‐O‐p‐nitrobenzoyl‐β‐cyclodextrin (pNBCD) and mono‐6‐O‐m‐nitrobenzoyl‐β‐cyclodextrin (mNBCD) was studied in detail. It was found that very efficient fluorescence quenching could occur in these supramolecular systems. This quenching was attributed to the photoinduced electron transfer inside the supramolecular assembly between the naphthalene donors and cyclodextrin acceptors. Detailed Stern‐Volmer constants were measured and they were partitioned into dynamic Stern‐Volmer quenching constants and static binding constants. It was demonstrated that the binding constants between all the naphthalene compounds and cyclodextrins are the same as they possess the same binding site, i.e., adamantanamine.
Breast carcinoma chemoprevention in the community setting
Authors: Brewster Abenaa M. , Christo Dana K. , Lai Hong , Helzlsouer Kathy 
Published: January 2005

AbstractBACKGROUNDThe United States Preventive Services Task Force recommends that women who are at both high risk for breast carcinoma and low risk for adverse events should receive counseling regarding tamoxifen for chemoprevention. Estimates of the risks and benefits of tamoxifen based on results from clinical trials may not reflect the real‐world experience. The authors determined the prevalence of women in a community‐based cohort who would meet the definition of high risk for breast carcinoma and calculated the number of women needed to screen to determine one for whom the benefits of tamoxifen would outweigh the risks. Baseline incidence also was examined for adverse health events in this community‐based cohort compared with participants in the Breast Cancer Prevention Trial.METHODSThe study participants were women ages 40–70 years (n = 6048 women) who were members of the CLUE II cohort, which started in 1989, and who responded to questionnaire surveys in 1996 and 2000.RESULTSEighteen percent of all women had a 5‐year risk of invasive breast carcinoma ≥ 1.66%. The number of women needed to screen to find 1 woman for whom the benefits outweighed the risks of tamoxifen ranged from 26 women ages 40–49 years to 142 women ages 60–70 years. For women who had undergone a hysterectomy, the numbers needed to screen were lower. Baseline incidence rates of fracture and thromboembolic disease were higher in the community‐based cohort compared with the rates observed among prevention trial participants; thus, fewer women had to be treated with tamoxifen to prevent one fracture. However, fewer women in the community also had to be treated to observe harm with a thromboembolic event.CONCLUSIONSClinicians who counsel women about tamoxifen should take into consideration community‐level risks and benefits. Cancer 2005. © 2005 American Cancer Society.
Neighborhood composition and incidence of cancer among Hispanics in the United States
Authors: Eschbach Karl , Mahnken Jonathan D. , Goodwin James S. 
Published: January 2005

AbstractBACKGROUNDHispanics in the United States have a 33% lower age‐adjusted incidence of cancer and a 38% lower cancer mortality rate compared with non‐Hispanic whites. This may be secondary to health behaviors that vary with residential and economic assimilation. The authors investigated whether cancer incidence among Hispanics increased with residential and economic assimilation into mainstream culture.METHODSData from the Surveillance, Epidemiology, and End Results program (SEER) and the U.S. Census Bureau were used to compare cancer incidence rates and rate ratios as a function of percentage of Hispanics and income of Hispanics in a census tract. Type of cancer was identified with a site recode variable in the SEER data set. Cases with in situ prostate and cervical carcinoma were excluded. Hispanic ethnicity in SEER was identified by medical record review and Hispanic surname lists. The study also used income of Hispanics living in the census tract, age at diagnosis, and stratification by gender.RESULTSThe incidence of breast, colorectal, and lung carcinoma among Hispanics increased as the percentage of Hispanics in the census tract decreased and as tract Hispanic income increased. For example, there was a 39% reduction in breast carcinoma and a 38% reduction in male colorectal carcinoma when the Hispanic population in high‐density Hispanic neighborhoods in the lowest income quartile was contrasted to Hispanics living in tracts with the lowest total percentage of Hispanics in the highest income quartile.CONCLUSIONSThe lower cancer rates among Hispanics relative to non‐Hispanic whites in the United States may dissipate as Hispanics become more assimilated into the mainstream society. Cancer 2005. © 2005 American Cancer Society.
Detection of recurrence in childhood solid tumors
Authors: Howell Lisa , Mensah Adjoa , Brennan Bernadette , Makin Guy 
Published: January 2005

AbstractBACKGROUNDFrequent follow‐up and regular investigation are routine in pediatric oncology. However, there is little evidence regarding their value in the detection of recurrent disease.METHODSThe authors carried out a retrospective study of the follow‐up of 186 children with solid tumors who were diagnosed between 1992 and 1996. The numbers of clinic visits, follow‐up investigations, and (if appropriate) the mode of recurrence detection were recorded.RESULTSThe mean follow‐up was 5.9 years. During this time, 37 recurrences were detected, symptomatically in 54% of patients, by routine investigation in 30% of patients, and at routine clinic appointment in 16% of patients. It was calculated that routine magnetic resonance imaging detected 1 recurrence for every 42 scans performed, routine computed tomography detected 1 recurrence for every 129 scans performed, and routine chest radiography detected 1 recurrence for every 257 films.CONCLUSIONSThe current results raise questions regarding the usefulness of such follow‐up in children with solid tumors. Cancer 2005. © 2005 American Cancer Society.
Distribution of estrogen receptor alpha mRNA in the brain and inner ear of a vocal fish with comparisons to sites of aromatase expression
Authors: Forlano Paul M. , Deitcher David L. , Bass Andrew H. 
Published: January 2005

AbstractAmong vertebrates, teleost fish have the greatest capacity for estrogen production in the brain. Previously, we characterized the distribution of the estrogen‐synthesizing enzyme aromatase in the brain of the midshipman fish. Here, we investigated the distribution of estrogen receptor alpha (ERα). A partial cDNA of ERα was cloned and used to generate midshipman‐specific primers for RT and real‐time PCR which identified transcripts in liver and ovary, the CNS, and the sensory epithelium of the main auditory endorgan (sacculus). In situ hybridization revealed abundant expression throughout the preoptic area, a vocal‐acoustic site in the hypothalamus, amygdala homologs of the dorsal pallium, the pineal organ, the inner ear, the pituitary, and the ovary. Weaker expression was found in the midbrain's nucleus of the medial longitudinal fasciculus and in the dimorphic vocal motor nucleus. ERα expression in the pineal, gonad, and pituitary axis may function to time seasonal abiotic cues to reproductive state, while expression in the vocal motor and auditory systems support neurophysiological evidence for estrogen as a modulator of vocal motor and auditory encoding mechanisms in midshipman fish. While ERα is restricted to specific nuclei, aromatase expression is abundant in glial cells throughout the entire forebrain, and high in midbrain and hindbrain – spinal vocal regions. The only site of aromatase‐containing neurons is in the peripheral auditory system, where it is localized to ganglion cells in the auditory nerve. Estrogen production proximal to ERα‐positive neurons may provide for focal sites of estrogen effects on reproductive‐, vocal‐, and auditory‐related neurons. J. Comp. Neurol. 483:91–113, 2005. © 2005 Wiley‐Liss, Inc.
Strategies for the efficient exploitation of loop‐level parallelism in Java
Authors: Oliver José , Guitart Jordi , Ayguadé Eduard , Navarro Nacho , Torres Jordi 
Published: January 2005

AbstractThis paper analyzes the overheads incurred in the exploitation of loop‐level parallelism using Java Threads and proposes some code transformations that minimize them. The transformations avoid the intensive use of Java Threads and reduce the number of classes used to specify the parallelism in the application (which reduces the time for class loading). The use of such transformations results in promising performance gains that may encourage the use of Java for exploiting loop‐level parallelism in the framework of OpenMP. On average, the execution time for our synthetic benchmarks is reduced by 50% from the simplest transformation when eight threads are used. The paper explores some possible enhancements to the Java threading API oriented towards improving the application–runtime interaction. Copyright © 2001 John Wiley & Sons, Ltd.