bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global dimming and global brightening—an analysis of surface radiation and cloud cover data in northern Europe
Authors: Stjern Camilla W. , Kristjánsson Jón Egill , Hansen Aksel Walløe 
Published: July 2008

AbstractIn the present study, surface solar radiation data from 11 stations in northwestern Europe and the European Arctic are presented in the context of the ongoing discussion on global dimming and global brightening. The surface solar radiation records are compared to records of cloud cover, and to qualitative information on aerosol concentrations and atmospheric circulation patterns, in order to explain the temporal variations.Through simple statistical analyses, we examine annual trends as well as trends for individual months, and compare the results between the stations. Comparisons are also made between different time periods within the records. We find that surface solar radiation changes in the region considered, even at the remote arctic stations, correspond well with trends found in global studies, with a significant decrease from the 1950s to the 1980s, followed by a slight increase in recent years. At stations that stand out from the general pattern, the deviations can be explained by variations in cloud cover in most cases.There has been a general tendency to attribute the majority of the observed surface solar radiation trends to aerosol changes caused by changes in anthropogenic emissions. This study stresses the importance of the contribution of clouds and the atmospheric circulation to global dimming and global brightening. Copyright © 2008 Royal Meteorological Society
Systematic biotic responses to palaeoenvironmental change in the Late Pleistocene southern South China Sea: a preliminary study
Authors: Chen Muhong , Li Qianyu , Zhang Lanlan , Zheng Fan , Lu Jun , Xiang Rong , Zhang Lili , Yan Wen , Chen Zhong , Xiao Shangbin 
Published: July 2008

AbstractOxygen and carbon isotopes from the planktonic foraminifer Globigerinoides sacculifer, trace element contents, calcium carbonate, biogenic silica, grain size, and abundances of diatoms, radiolarians and foraminifera in a deep‐sea core from the southwestern South China Sea were analysed to investigate the response of various marine ecological communities to environmental changes over the last 200 ka. The synthesised results show that the quality of the palaeoecological environment for biological growth is primarily affected by nutrient supply and terrigenous disturbance. Ba and P are important nutrient elements for the growth of diatoms, radiolarians and planktonic foraminifera. Together with dissolved silica and calcium carbonate in sea water, these elements may control microbiotic development. However, variations in Fe content appear to affect diatom and radiolarian abundance. Optimal biotic growth occurs when nutrients are abundant and when there is minimal terrigenous disturbance. Biotic growth decreases when sea water is highly oligotrophic and terrigenous input is high. Maximum biological growth occurred in the mid Holocene, but deteriorated soon afterwards owing to increased terrigenous input, causing a decrease of biological abundance and productivity in the late Holocene. The results also indicate how the Toba volcanic eruption ca. 74 ka ago contributed to changing the ecological environment in the southern South China Sea. Copyright © 2008 John Wiley & Sons, Ltd.
Subfossil Chironomidae (Insecta: Diptera) along a latitudinal gradient in Finland: development of a new temperature inference model
Authors: Luoto Tomi P. 
Published: July 2008

AbstractNumerical techniques were used to study chironomid distribution and abundance in lakes from a 1000 km transect in Finland, with special interest on the effect of local summer air temperatures on chironomid assemblages. The final aim of the study was to develop a chironomid‐based palaeotemperature inference model. The dataset consisted of 82 lakes (of which 77 were used in the model after deletion of outliers), with catchments spanning from boreal coniferous forests to mountain birch woodland and tundra vegetation. Numerical analysis showed that the mean July air temperature was the most significant variable explaining the distribution and abundance of chironomids in Finnish lakes. Weighted‐averaging partial least squares techniques were used to develop a palaeotemperature inference model for mean July air temperature reconstructions. The model performance statistics were favourable, with cross‐validated coefficient of determination (r2) of 0.78, root mean squared error of prediction of 0.721°C and maximum bias of 0.794°C. Based on these values, the transfer function is a valid means of performing quantitative palaeotemperature estimates in downcore studies. Copyright © 2008 John Wiley & Sons, Ltd.
Changing management and outcome of hepatocellular carcinoma: Evaluation of 501 patients treated at a single comprehensive center
Authors: Kooby David A. , Egnatashvili Vasili , Graiser Michael , Delman Keith A. , Kauh John , Wood William C. , Staley III Charles A. 
Published: July 2008

AbstractBackgroundWe evaluated changes in therapy and outcome for patients with hepatocellular carcinoma (HCC) over time in a large cohort of Western patients managed at one U.S. medical center.MethodsA retrospective analysis of all patients with HCC treated at one U.S. medical center was performed. Analyses were stratified by time intervals 1990–1996 (pre‐Milan) and 1997–2004 (post‐Milan) to examine impact of UNOS criteria adapted from the post‐Milan experience with OLT on treatment and survival.ResultsFrom 1990 to 2004, 501 patients were identified, 170 (34%) pre‐Milan and 331 (66%) post‐Milan. Seventy‐four (15%) underwent OLT, 99 (20%) had partial hepatectomy (PH), 51 (10%) had ablative therapy (Ablate), 84 (16%) had embolic treatment (Embo), and 194 (39%) had chemotherapy or supportive care (C/SC). Median survival for all patients was 11 months. By time interval, median overall survival (OS) was better for post‐Milan patients as compared with the pre‐Milan group (13 months vs. 7 months, P = 0.02). On multivariate analysis OLT had the strongest association with improved survival of all factors examined (Odds ratio 12.4, 95% CI 7.7–20.5).ConclusionsIn this series, treatment post‐1996 is associated with improved survival, likely due to improvements in selection criteria and outcomes for liver transplantation. J. Surg. Oncol. 2008;98:81–88. © 2008 Wiley‐Liss, Inc.
Aberrant crypt foci as precursors in colorectal cancer progression
Authors: Orlando Frank A. , Tan Dongfeng , Baltodano Juan D. , Khoury Thaer , Gibbs John F. , Hassid Victor J. , Ahmed Bestoun H. , Alrawi Sadir J. 
Published: July 2008

AbstractColorectal cancer progression originates when accumulated genetic and epigenetic alterations cause genomic instability and a malignant phenotype. Subsequent molecular pathway deregulation leads to histopathologic changes that are clinically evident as aberrant crypt foci (ACF) and visualized by high‐magnification chromoscopic colonoscopy. ACF are biomarkers of increased colorectal cancer risk, particularly those with dysplastic features. Genetic profiling using genomic instability, loss of heterozygosity, and methylation analysis has revealed a minority population of ACF genotypically analogous to cancer. J. Surg. Oncol. 2008;98:207–213. © 2008 Wiley‐Liss, Inc.
Chronological changing patterns of clinical characteristics of Korean breast cancer patients during 10 years (1996–2006) using nationwide breast cancer registration on‐line program: Biannual update
Authors: Ko Seung Sang ,   and The Korean Breast Cancer Society
Published: July 2008

AbstractBackgroundWe performed this study to evaluate the chronological changes in Korean breast cancer characteristics and reproductive factors from 1996 to 2006.Materials and MethodsWe analyzed the chronological changes among newly diagnosed primary breast cancer patients recruited at 102 general hospitals. All participating hospitals provided the essential information through the nationwide on‐line registration program.ResultsEleven thousand two hundred seventy five cases of breast cancer were newly diagnosed in 2006. The crude incidence rate of breast cancer of 2006 was 46 (average 47.0 ± 10.8) among 100,000 and the patient's median age was 48 (average 49.2 ± 10.4) years (P < 0.001). In a difference from the United States and Western countries, the age distribution of breast cancer peaked in the fifth decade of life; this was followed by the sixth, fourth, and seventh decades. Compared with the results of previous studies 1996, this study also showed a continuous increase in: the incidence; breast‐conserving surgery; breast reconstruction after operation; the percentage of early breast cancer; and the number of patients with risk factors.ConclusionOur results suggest the incidence of breast cancer in Korea will continue to rise. Several characteristics of Korean breast cancer patients seem to follow the patterns of Western countries, but differences are present. J. Surg. Oncol. 2008;98:318–323. © 2008 Wiley‐Liss, Inc.
Efficacy of glycoprotein enrichment by microscale lectin affinity chromatography
Authors: Madera Milan , Mann Benjamin , Mechref Yehia , Novotny Milos V. 
Published: July 2008

AbstractReproducible and efficient affinity enrichment is increasingly viewed as an essential step in many investigations leading to the discovery of new biomarkers. In this work, we have evaluated the repeatability of lectin enrichment of glycoproteins from human blood serum through both qualitative and quantitative proteomic approaches. In a comprehensive evaluation of lectin binding, we have performed 30 separate microscale lectin affinity chromatography experiments, followed by a conventional sample purification, and LC‐MS/MS analysis of the enriched glycoproteins. Two lectin affinity matrixes, both with Con A lectin, immobilized to the same solid support but differing in the amount of immobilized lectin, were investigated to characterize their binding properties. Both qualitative and quantitative data indicate acceptable repeatability and binding efficiency for the lectin materials received from two different commercial sources.
Sampling flower scent for chromatographic analysis
Authors: Stashenko Elena E. , Martínez Jairo René 
Published: July 2008

AbstractThe analysis of flower volatiles requires special methods for their isolation with enrichment. Living flowers show a continuous change in their volatile profile that depends on intrinsic (genetic) and external (light, temperature, hydric stress) factors. Excised flowers suffer rapid deterioration and loss of volatiles. While industrial isolation methods for flower volatiles are well established, those at the laboratory‐scale experience progressive development, in the search for higher sensitivity, reproducibility, and simplicity. This review covers the flower scent sampling methods most commonly employed during the last decade, and includes comments on their strengths and limitations. The strengths of headspace solid‐phase microextraction (HS‐SPME) forin vivomonitoring are emphasized with the examples of monitoring the circadian variation ofBrugmansia suaveolensflower scent and of volatile aldehyde detection in flower scent using on‐fiber derivatization.
Polymethacrylate monolithic columns for capillary liquid chromatography
Authors: Urban Jiří , Jandera Pavel 
Published: July 2008

AbstractIn recent years, continuous separation media have attracted considerable attention because of the advantages they offer over packed columns. This research resulted in two useful monolithic material types, the first based on modified silica gel and the second on organic polymers. This work attempts to review advances in the development, characterization, and applications of monolithic columns based on synthetic polymers in capillary chromatography, with the main focus on monolithic beds prepared from methacrylate‐ester based monomers. The polymerization conditions used in the production of polymethacrylate monolithic capillary columns are surveyed, with attention being paid to the concentrations of monomers, porogen solvents, and polymerization initiators as the system variables used to control the porous and hydrodynamic properties of the monolithic media. The simplicity of their preparation as well as the possibilities of controlling of their porous properties and surface chemistries are the main benefits of the polymer monolithic capillary columns in comparison to capillary columns packed with particulate materials. The application areas considered in this review concern mainly separations in reversed‐phase chromatography, ion‐exchange chromatography, hydrophobic and hydrophilic interaction modes; enzyme immobilization and sample preparation in the capillary chromatography format are also addressed.
Evaluation of use of a very short polar microbore column segment in high‐speed gas chromatography analysis
Authors: Quinto Tranchida Peter , Mondello Monica , Sciarrone Danilo , Dugo Paola , Dugo Giovanni , Mondello Luigi 
Published: July 2008

AbstractVery fast GC analyses are commonly carried out by using 10 m×0.1 mm id capillaries. In order to achieve rapid elution times (1–3 min), the latter are operated under suboptimum conditions. The present research is focused on the evaluation of use of a 0.1 mm id polar column segment (2 m), operated under near‐to‐optimum conditions, in very fast GC analysis. The results attained are compared with those derived from using a 10 m microbore column in very fast GC experiments. Prior to method development, the effects of gas velocity, temperature program rate, and sample amounts on analytical performance were evaluated. Following these preliminary applications, a complex lipidic sample, cod liver oil, was subjected to rapid separation (∼︁2.1 min) on the 10 m capillary through the application of a 50°C/min temperature rate and a 130 cm/s gas velocity. The same matrix was analyzed on the 2 m capillary using the same temperature program rate and range, but with a close‐to‐ideal linear velocity. The results observed were of interest, as the separation was achieved in less time (1.45 min) with improved peak resolution. Finally, both methods were validated in terms of retention time and peak area repeatability, LOQ, and linearity.
Effects of alcohols on CE enantioseparation of basic drugs with native γ‐CD as chiral selector
Authors: Deñola Nerissa L. , Quiming Noel S. , Catabay Alicia P. , Saito Yoshihiro , Jinno Kiyokatsu 
Published: July 2008

AbstractThe effects of alcohol on the CE enantioseparation of selected basic drugs with γ‐CD as the chiral selector was investigated. The enantioseparation behavior of the analytes with γ‐CD in the absence and presence of different alcohols specifically methanol, ethanol, 2‐propanol (IPA), and 2‐methyl‐2‐propanol (TBA), the relationship of enantiomeric resolution (Rs) values with either hydrophobicity or bulkiness of the alcohols, as well as the effect of these alcohols on interaction of the analytes with γ‐CD were studied. Results showed that hydrophobicity and/or bulkiness of alcohols have an influence on the enantioresolution of most of the analytes based on the relatively high correlation coefficients (R) obtained between Rs versus log P and between Rs versus ovality (i.e., parameter to indicate bulkiness of a molecule). Comparison of the values of the average binding constants obtained for each enantiomeric pair in the presence and absence of 5% IPA showed that alcohols can increase, decrease, or give a minimal effect on the analyte‐γ‐CD interaction depending on the analyte. Furthermore, the significant enhancement in the enantioresolution of both propranolol and pindolol in the presence of either IPA or TBA led to the baseline enantioresolution of both drugs using 35 mM γ‐CD.
Kinetics of aerobic and anaerobic oxidations of ethanol by Fenton's reagent
Authors: Kremer Mordechai L. 
Published: July 2008

AbstractFor the first time, the time dependence of [H2O2] and [Fe2+] was followed during the aerobic oxidation of ethanol by Fenton's reagent. It was found that part of the ethanol was oxidized by dissolved O2 via the transient formation of H2O2. A model was set up based on FeO2+ as the key intermediate. Both one‐ and two‐equivalent oxidations of ethanol occur, the former producing radical species derived from ethanol. No free radicals derived from H2O2 play part in the system. The relevant rate constants or their ratios were determined. The mechanism accounted successfully also for the anaerobic oxidation of ethanol. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 541–553, 2008
Dynamics and kinetics of the S + HO2 reaction: A theoretical study
Authors: Ballester M. Y. , Varandas A. J. C. 
Published: July 2008

AbstractWe report a quasi‐classical trajectory study of the S + HO2 reaction using a previously reported global potential energy surface for the ground electronic state of HSO2. Zero‐point energy leakage is approximately accounted for by using the vibrational energy quantum mechanical threshold method. Calculations are carried out both for specific ro‐vibrational states of the reactants and thermalized ones, with rate constants being reported as a function of temperature. The results suggest that the title reaction is capture type, with OH and SO showing as the most favorable products. The internal energy distribution of such products and the reaction mechanism are also investigated. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 533–540, 2008
Residuated lattices arising from equivalence relations on Boolean and Brouwerian algebras
Authors: Vetterlein Thomas 
Published: July 2008

AbstractLogics designed to deal with vague statements typically allow algebraic semantics such that propositions are interpreted by elements of residuated lattices. The structure of these algebras is in general still unknown, and in the cases that a detailed description is available, to understand its significance for logics can be difficult. So the question seems interesting under which circumstances residuated lattices arise from simpler algebras in some natural way. A possible construction is described in this paper.Namely, we consider pairs consisting of a Brouwerian algebra (i. e. a dual Heyting algebra) and an equivalence relation. The latter is assumed to be in a certain sense compatible with the partial order, with the formation of differences, and with the formation of suprema of pseudoorthogonal elements; we then call it an s‐equivalence relation. We consider operations which, under a suitable additional assumption, naturally arise on the quotient set. The result is that the quotient set bears the structure of a residuated lattice. Further postulates lead to dual BL‐algebras. In the case that we begin with Boolean algebras instead, we arrive at dual MV‐algebras. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mesoporous Polymeric Materials Tailored from Oligoester‐Derivatized Interpenetrating Polymer Networks
Authors: Rohman Géraldine , Grande Daniel 
Published: July 2008

AbstractThe utilization of semi‐hydrolyzable oligoester‐derivatized Interpenetrating Polymer Networks (IPNs) as nanostructured precursors provides a straightforward and effective route to novel (meso)porous networks. In a first stage, different types of poly(D,L‐lactide)/poly(methyl methacrylate)‐based IPNs were synthesized by resorting to the so‐called in situ sequential method. In a second stage, the quantitative hydrolysis of the polyester sub‐network afforded porous structures with pore sizes ranging from 10 to 100 nm. The potentialities offered by this versatile approach were discussed, and the porosity of the resulting methacrylic networks was examined by Scanning Electron Microscopy (SEM) and thermoporometry using Differential Scanning Calorimetry (DSC).
Microporous, Thermosensitive Organic‐Inorganic Hybrid Hydrogel Prepared by Freezing
Authors: Kato Norihiro 
Published: July 2008

AbstractThermally triggered shrinking rates of poly(N‐isopropyl‐acrylamide) (PNIPA) ‐based organic‐inorganic hydrogel could be accelerated by applying the ice templating method. Freezing and subsequent rehydration of gels is an effective way to prepare the porous polymer network that leads to rapid expelling of pore water. The shrinking coefficients obtained by fitting Fick's law to the data increased two orders of magnitude as compared with the conventional gel before freezing. The microstructure of gels generated during freezing gels had advantage to expel the pore water rapidly probably due to the PNIPA aggregation through the hydrophobic interaction.
Tuning the Surface/Bulk Properties by the Control of the Amphiphilic Profile in Gradient Copolymer
Authors: Karaky Khaled , Derail Christophe , Reiter Gunter , Billon Laurent 
Published: July 2008

AbstractNitroxide Mediated Radical Polymerization (NMP) combined with the Semi‐Batch process is used for synthesize poly(N,N‐Dimethylacrylamide‐grad‐Butyl acrylate), called poly(DMA‐grad‐BuA), in the presence of SG1 as control agent and the alkoxyamine (MAMA) as initiator. The instantaneous composition is used to characterize the gradient copolymers. The variation of the addition rate of DMA influences on the incorporation of DMA in the macromolecular chains. The thermal/rheological properties of gradient copolymers in bulk are also studied and discussed in relation with their local structure.
Alternative Synthetic Routes to Epoxy Polymer – Clay Nanocomposites using Organic or Mixed‐Ion Clays Modified by Protonated Di/Triamines (Jeffamines)
Authors: Triantafyllidis Kostas S. , Xidas Panagiotis I. , Pinnavaia Thomas J. 
Published: July 2008

AbstractThe use of homoionic organic clays and mixed‐ion organic/inorganic clays modified by di‐ or triamines (Jeffamines), which are being used as epoxy resin curing agents, in the synthesis of polymer nanocomposites has been studied in this work. Our aim is to enhance polymer crosslinking and interfacial adhesion in the nanocomposite structure by utilizing the functionality of the di/triamines on the surface of clay nanolayers and by reducing the organic modifier via formation of homostructured mixed‐ion organic/inorganic clays. The results show that the use of homoionic organic clays exchanged with relatively short chain di‐ or triamines and mixed‐ion organic/inorganic clays partially exchanged (ca. 35%) with long chain diamines resulted in intercalated structures with enhanced thermo‐mechanical properties (Young's Modulus, Storage Modulus). On the other hand, homoionic organic clays exchanged with long chain diamines and triamines resulted in exfoliated nanocomposites but with compromised mechanical properties due to the plasticizing effect of the long chain amine modifiers.
Network Formation in PP/Layered Silicate Nanocomposites: Modeling and Analysis of Rheological Properties
Authors: Kovács János , Dominkovics Zita , Vörös György , Pukánszky Béla 
Published: July 2008

AbstractPP/organophilic montmorillonite composites were prepared from PP homopolymer, maleinated polypropylene and a clay organophilized with octadecyl amine. Various approaches were used to analyze the rheological properties of the composites. Cole‐Cole plots proved to be useful, since they detect the network very sensitively. The frequency dependence of the real part of complex viscosity was described with a series of Maxwel bodies coupled parallel to each other. The relaxation time of the melt changed in the range of 0.0005 and 200 sec. Under certain conditions long relaxation times appear in the spectrum, which indicate the formation of new structural units, probably a silicate network. A certain number of silicate layers are needed to create a house‐of‐cards structure. A threshold concentration of MAPP exists for network formation, which depends on silicate content.