bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic profiling of pteridines for determination of potential biomarkers in cancer diseases
Authors: Kośliński Piotr , Bujak Renata , Daghir Emilia , Markuszewski Michał J. 
Published: May 2011

AbstractCancer disease is the second leading cause of death in the world. Epidemiology data indicate that early diagnosis of a tumour increases a patient's chance of recovery. Biomarkers are effective instruments which can potentially lead to precancer screening or precancer diagnosis and may provide useful information on the cancer type and the disease's stage of progression. The analysis of new biomarkers for cancer is currently a popular area of study in clinical and cancer research. Pteridines are a class of potential cancer biomarkers. The monitoring levels of pteridines may have prospective value for controlling the course of the malignant process. This review describes the functional employment of pteridines, as biomarkers, in cancer diagnosis. It also contains the description of application of analytical techniques such as high‐performance liquid chromatography (HPLC) and capillary electrophoresis (CE) used for pteridine analysis.
Large‐volume sample on‐line concentration of angiotensins in non‐aqueous capillary electrophoresis
Authors: Kitagawa Shinya , Noji Akitsugu , Matsushita Naofumi , Nakagawa Hiroyuki , Asai Takahiro , Ohitani Hajime 
Published: May 2011

AbstractA single step on‐line concentration and separation method for peptides in non‐aqueous capillary electrophoresis was developed. ACN containing 50 mM tetraethylammonium perchlorate was used as the electrophoretic medium; angiotensins I–IV were separated as a result of the differences in the magnitudes of their interactions with perchlorate anions. When the sample solution (ACN containing 0.5% trifluoroacetic acid and angiotensins) was injected as a large‐volume plug, the analytes were concentrated at the inlet end of the capillary by both sweeping and stacking mechanisms; the separation procedure then started automatically without any operations such as polarity change. It was found that the concentration of analytes, injection period, and concentration of tetraethylammonium perchlorate in the electrophoretic medium were important factors for both separation and concentration efficiencies. The angiotensins were concentrated and separated with the large‐volume injection of up to 80% of the effective capillary length.
Optimizing protein recovery yield from serum samples treated with beads technology
Authors: Bellei Elisa , Monari Emanuela , Bergamini Stefania , Ozben Tomris , Tomasi Aldo 
Published: May 2011

AbstractProteomics studies are often complicated by the wide dynamic range of the biological fluids, in which few highly abundant proteins obscure the signal of low abundant ones. To overcome this problem, several techniques have been developed on the basis of “depletion principles,” namely immuno‐subtraction with specific antibodies against the most‐abundant proteins. Unfortunately, the probability of codepletion is a noteworthy drawback associated with these strategies. The ProteoMiner™ (PM) technology is a novel approach, consisting of a combinatorial library of hexapeptide ligands coupled to beads, that allows the capture of all species present in a proteome, but at much reduced protein concentration differences, simultaneously enhancing the concentration of the most dilute species. In this study, we evaluated the compatibility of the PM kit's elution reagent with 2‐DE analysis, comparing five different purification methods on serum samples eluted from the beads: the “ReadyPrep 2‐D Clean‐up kit” and precipitation with organic solvents, as acetone/methanol, TCA/acetone, ACN, and chloroform/methanol. Considering protein recovery yield (quantity) and 2‐DE spot pattern (quality), precipitation with ACN offered the most promising approach, showing the best spot resolution in all regions of the pH gradient and the greatest number of protein spots visualized on 2‐D gels.
Cave digitabula!
Authors: Françoise Lasne , Laurent Martin , Jean‐Antoine Martin 
Published: May 2011

AbstractWe report here observations clearly demonstrating that gloves can have a deleterious impact on an IEF experiment. These observations were made during the practice of analyses for anti‐doping control of erythropoietin. We show that the wearing of nitrile gloves to apply the catholyte strip onto the IEF gel may be responsible for dramatic distortions in the pattern of this hormone. These observations point out that gloves must not be considered only as protective items but also as possible factors in an analytic process.
Important electromigration effects of carbon dioxide in capillary electrophoresis at high pH
Authors: Malá Zdena , Gebauer Petr , Boček Petr 
Published: May 2011

AbstractThis paper deals with unwanted effects of carbonate in capillary zone electrophoretic analyses of anions in alkaline BGEs with indirect UV absorption and conductivity detection. Computer simulations and experimental study of selected model systems have shown that carbon dioxide absorbed from air into BGEs and samples induce important electrophoretic effects like formation of new additional zones and/or boundaries that may further induce strong and pronounced temporary changes in the migration of analytes. Examples are reduction of the pH of alkaline BGEs around pH 11 by up to 1 unit or formation of a pronounced detectable carbon dioxide peak comparable with peaks of analytes at 1 mM level. The higher the pH of the BGE, the stronger these effects and the broader their spectrum, involving (i) changes of effective mobilities and selectivity due to changes in pH of the BGE, (ii) occurrence of additional system zones appearing in form of peaks, dips or more complex disturbances in the detection signal, (iii) temporary interactions with the sample components and subsequent modification of the separation process and of its result. This paper reveals all these effects and brings the knowledge necessary to prevent problems with qualitative and quantitative evaluation of the analysis results.
A novel hybrid mode of sample injection to enhance CZE sensitivity for simultaneous determination of a pyridine‐triphenylborane anti‐fouling agent and its degradation products
Authors: Kaewchuay Netnapit , Yakushiji Yuki , Fukushi Keiichi , Saito Keiitsu , Hirokawa Takeshi 
Published: May 2011

AbstractWe developed a novel hybrid sample injection mode (HSIM) that presents the combination of electrokinetic injection and vacuum injection to enhance detection sensitivity in CZE. Samples were introduced using both vacuum and electrokinetic injections simultaneously, with a water plug injected into the capillary prior to sample introduction (i.e. similarly to field‐amplified sample injection, FASI). Using a sample mixture containing an anti‐fouling agent applied to ship hulls, pyridine‐triphenylborane and its degradation products (diphenylborinic acid, phenylboronic acid, and phenol) dissolved in ACN, the length of water plug, time, and voltage for sample introduction were optimized. The signal intensity (peak height) was found to be up to a 30‐fold increased using HSIM by applying 4 kV for 4 s at the inlet end of the capillary as the cathode with supplementary vacuum in comparison with only vacuum injection for 4 s. The LODs (at a S/N of 3) for pyridine‐triphenylborane, diphenylborinic acid, phenylboronic acid, and phenol were 0.88, 1.0, 21, and 23 μg/L, respectively. At the level of 0.04 mg/L, the RSDs (n=4, intra‐day) for the above analytes were in the ranges of 1.9–11, 4.3–9.2, and 0.34–0.66% for peak area, peak height, and migration time, respectively. The HSIM is a simple and promising procedure useful for enhancing the sensitivity for both low‐and high‐mobility ions in CZE.
Finite element‐fictitious boundary methods (FEM‐FBM) for 3D particulate flow
Authors: Münster R. , Mierka O. , Turek S. 
Published: May 2011

AbstractIn this paper we discuss numerical simulation techniques using a finite element approach in combination with the fictitious boundary method (FBM) for rigid particulate flow configurations in 3D. The flow is computed with a multigrid finite element solver (FEATFLOW), the solid particles are allowed to move freely through the computational mesh which can be static or adaptively aligned by a grid deformation method allowing structured as well as unstructured meshes. We explain the details of how we can use the FBM to simulate flows with complex geometries that are hard to describe analytically. Stationary and time‐dependent numerical examples, demonstrating the use of such geometries are provided. Our numerical results include well‐known benchmark configurations showing that the method can accurately and efficiently handle prototypical particulate flow situations in 3D with particles of different shape and size. Copyright © 2011 John Wiley & Sons, Ltd.
Adaptive non‐conformal mesh refinement and extended finite element method for viscous flow inside complex moving geometries
Authors: Sarhangi Fard A. , Hulsen M. A. , Meijer H. E. H. , Famili N. M. H. , Anderson P. D. 
Published: May 2011

SUMMARYTwo different techniques to analyze non‐Newtonian viscous flow in complex geometries with internal moving parts and narrow gaps are compared. The first technique is a non‐conforming mesh refinement approach based on the fictitious domain method (FDM), and the second one is the extended finite element method (XFEM). The refinement technique uses one fixed reference mesh, and to impose continuity across non‐conforming regions, constraints using Lagrangian multipliers are used. The size of elements locally in the high shear rate regions is reduced to increase accuracy. FDM is shown to have limitations; therefore, XFEM is applied to decouple the fluid from the internal moving rigid bodies. In XFEM, the discontinuous field variables are captured by using virtual degrees of freedom that serve as enrichment and by applying special integration over the intersected elements. The accuracy of the two methods is demonstrated by direct comparison with results of a boundary‐fitted mesh applied to a two‐dimensional cross section of a twin‐screw extruder. Compared with non‐conforming FDM, XFEM shows a considerable improvement in accuracy around the rigid body, especially in the narrow gap regions. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of splicing mutations on NF2‐transcripts: Transcript analysis and information theoretic predictions
Authors: Ellis James R. , Heinrich Bianca , Mautner Victor‐F. , Kluwe Lan 
Published: May 2011

AbstractThis study examined the effects of 22 putative splicing mutations in the NF2 gene by means of transcript analysis and information theory based prediction. Fourteen mutations were within the dinucleotide acceptor and donor regions, often referred to as (AG/GT) sequences. Six were outside these dinucleotide regions but within the more broadly defined splicing regions used in the information theory based model. Two others were in introns and outside the broadly defined regions. Transcript analysis revealed exon skipping or activation of one or more cryptic splicing sites for 17 mutations. No alterations were found for the two intronic mutations and for three mutations in the broadly defined splicing regions. Concordance and partial concordance between the calculated predictions and the results of transcript analysis were found for 14 and 6 mutations, respectively. For two mutations, the predicted alteration was not found in the transcripts. Our results demonstrate that the effects of splicing mutations in NF2 are often complex and that information theory based analysis is helpful in elucidating the consequences of these mutations. © 2011 Wiley‐Liss, Inc.
13q14 Deletion size and number of deleted cells both influence prognosis in chronic lymphocytic leukemia
Authors: Dal Bo Michele , Rossi Francesca Maria , Rossi Davide , Deambrogi Clara , Bertoni Francesco , Del Giudice Ilaria , Palumbo Giuseppe , Nanni Mauro , Rinaldi Andrea , Kwee Ivo , Tissino Erika , Corradini Giorgia , Gozzetti Alessandro , Cencini Emanuele , Ladetto Marco , Coletta Angela Maria , Luciano Fabrizio , Bulian Pietro , Pozzato Gabriele , Laurenti Luca , Forconi Francesco , Di Raimondo Francesco , Marasca Roberto , Del Poeta Giovanni , Gaidano Gianluca , Foà Robin , Guarini Anna , Gattei Valter 
Published: May 2011

AbstractDeletion at 13q14 is detected by fluorescence in situ hybridization (FISH) in about 50% of chronic lymphocytic leukemia (CLL). Although CLL with 13q deletion as the sole cytogenetic abnormality (del13q‐only) usually have good prognosis, more aggressive clinical courses are documented for del13q‐only CLL carrying higher percentages of 13q deleted nuclei. Moreover, deletion at 13q of different sizes have been described, whose prognostic significance is still unknown. In a multi‐institutional cohort of 342 del13q‐only cases and in a consecutive unselected cohort of 265 CLL, we investigated the prognostic significance of 13q deletion, using the 13q FISH probes locus‐specific identifier (LSI)‐D13S319 and LSI‐RB1 that detect the DLEU2/MIR15A/MIR16‐1 and RB1 loci, respectively. Results indicated that both percentage of deleted nuclei and presence of larger deletions involving the RB1 locus cooperated to refine the prognosis of del13q‐only cases. In particular, CLL carrying <70% of 13q deleted nuclei with deletions not comprising the RB1 locus were characterized by particularly long time‐to‐treatment. Conversely, CLL with 13q deletion in <70% of nuclei but involving the RB1 locus, or CLL carrying 13q deletion in ≥70% of nuclei, with or without RB1 deletions, collectively experienced shorter time‐to‐treatment. A revised flowchart for the prognostic FISH assessment of del13q‐only CLL, implying the usage of both 13q probes, is proposed. © 2011 Wiley‐Liss, Inc.
Plasma homocysteine, brain imaging and cognition in older patients with mental illness
Authors: Nilsson Karin , Gustafson Lars , Hultberg Björn 
Published: May 2011

BackgroundTotal plasma homocysteine (tHcy) concentration is elevated in older patients with mental illness, and patients with vascular disease have higher plasma tHcy concentration than patients without vascular disease. Plasma tHcy has been reported to be associated with cognitive functions. The mechanism by which plasma tHcy may influence cognitive functions is not clear.MethodWe have investigated the relation between plasma tHcy, brain imaging findings (computer tomography scan [CT]) and cognition, measured as Mini mental state examination (MMSE), in 395 consecutively enrolled older patients with mental illness.ResultsAge and plasma tHcy were significant predictors of MMSE score, whereas pathological CT findings, indicating cerebrovascular disease, showed no prediction of MMSE score.ConclusionThe relation between plasma tHcy and cognition is not mediated by cerebrovascular disease as evaluated by pathological CT findings. Copyright © 2011 John Wiley & Sons, Ltd.
Reducing monitoring gaps at the aquifer–river interface by modelling groundwater–surface water exchange flow patterns
Authors: Munz Matthias , Krause Stefan , Tecklenburg Christina , Binley Andrew 
Published: May 2011

AbstractThis study investigates spatial patterns and temporal dynamics of aquifer–river exchange flow at a reach of the River Leith, UK. Observations of sub‐channel vertical hydraulic gradients at the field site indicate the dominance of groundwater up‐welling into the river and the absence of groundwater recharge from surface water. However, observed hydraulic heads do not provide information on potential surface water infiltration into the top 0–15 cm of the streambed as these depths are not covered by the existing experimental infrastructure. In order to evaluate whether surface water infiltration is likely to occur outside the ‘window of detection’, i.e. the shallow streambed, a numerical groundwater model is used to simulate hydrological exchanges between the aquifer and the river. Transient simulations of the successfully validated model (Nash and Sutcliff efficiency of 0·91) suggest that surface water infiltration is marginal and that the possibility of significant volumes of surface water infiltrating into non‐monitored shallow streambed sediments can be excluded for the simulation period. Furthermore, the simulation results show that with increasing head differences between river and aquifer towards the end of the simulation period, the impact of streambed topography and hydraulic conductivity on spatial patterns of exchange flow rates decreases. A set of peak flow scenarios with altered groundwater‐surface water head gradients is simulated in order to quantify the potential for surface water infiltration during characteristic winter flow conditions following the observation period. The results indicate that, particularly at the beginning of peak flow conditions, head gradients are likely to cause substantial increase in surface water infiltration into the streambed. The study highlights the potential for the improvement of process understanding of hyporheic exchange flow patterns at the stream reach scale by simulating aquifer‐river exchange fluxes with a standard numerical groundwater model and a simple but robust model structure and parameterization. Copyright © 2011 John Wiley & Sons, Ltd.
Pentapeptide‐modified poly(N,N‐diethylacrylamide) hydrogel scaffolds for tissue engineering
Authors: Horák Daniel , Matulka Kamil , Hlídková Helena , Lapčíková Monika , Beneš Milan J. , Jaroš Josef , Hampl Aleš , Dvořák Petr 
Published: May 2011

AbstractPoly(N,N‐diethylacrylamide) (PDEAAm) hydrogel scaffolds were prepared by radical copolymerization of N,N‐diethylacrylamide (DEAAm), N,N′‐methylenebisacrylamide and methacrylic acid in the presence of (NH4)2SO4 or NaCl. The hydrogels were characterized by low‐vacuum scanning electron microscopy in the water‐swollen state, water and cyclohexane regain, and by mercury porosimetry. The pentapeptide, YIGSR‐NH2, was immobilized on the hydrogel. Human embryonic stem cells (hESCs) were cultured with the hydrogels to test their biocompatibility. The results suggest that the PDEAAm hydrogel scaffolds are nontoxic and support hESC attachment and proliferation, and that interconnected pores of the scaffolds are important for hESC cultivation. Immobilization of YIGSR‐NH2 pentapeptide on the PDEAAm surface improved both adhesion and growth of hESCs compared with the unmodified hydrogel. The YIGSR‐NH2‐modified PDEAAm hydrogels may be a useful tool for tissue‐engineering purposes. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Synthesis and characterization of high‐quality skin‐cooling sheets containing thermosensitive poly(N‐isopropylacrylamid)
Authors: Takegami Yoshiaki , Yokoyama Yoshiyuki , Norisugi Osamu , Nagatsuma Masahiro , Takata Koji , Rehman Mati Ur , Matsunaga Kenji , Yokoi Hideharu , Fujiki Satoshi , Makino Teruhiko , Shimizu Tadamichi 
Published: May 2011

AbstractPoly(N‐isopropylacrylamide) (PNIPAAm) is the most popular thermosensitive polymer, and exhibits a low critical solution temperature of approximately 32°C. This study aimed to examine the usefulness of new cooling sheets, which are manufactured using a thermosensitive poly(N‐isopropylacrylamide) (PNIPAAm) material. We prepared cooling‐hydrogel sheets containing PNIPAAm (PNIPAAm sheet). We measured the skin temperature on the arms of the subjects using a thermograph and compared the usefulness of the PNIPAAm sheet and a control cooling‐hydrogel sheet that did not contain the PNIPAAm mixture. Thermographic measurements obtained 40 min after the treatment with the cooling sheets showed the skin temperature of the subjects treated with the 3.% (w/w) PNIPAAm sheets to be significantly lower than that of the subjects treated with the control cooling‐hydrogel sheet (p < 0.005). Compared with the control sheet, the cooling effect of the new PNIPAAm sheet also persisted for a longer duration (up to 100 min). The PNIPAAm sheets exhibited excellent cooling effects. This sheet may therefore be useful for lowering the body temperature of patients with high‐grade fever, such as fever due to influenza infection. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2011.
Is 4‐nitrobenzenethiol converted to p,p′‐dimercaptoazobenzene or 4‐aminothiophenol by surface photochemistry reaction?
Authors: Dong Bin , Fang Yurui , Xia Lixin , Xu Hongxing , Sun Mengtao 
Published: May 2011

AbstractFor the first time, the experimental and theoretical evidence for the conversion of 4‐nitrobenzenethiol (4‐NBT) to p,p′‐dimercaptoazobenzene (DMAB) in Ag and Cu sols by surface photochemistry reaction is obtained with surface‐enhanced Raman scattering (SERS) spectroscopy. The SERS spectrum of 4‐NBT in Cu sol is identical to that of DMAB produced from 4‐aminothiophenol in Ag sol as reported in recent literature, thereby providing direct spectral evidence. Copyright © 2011 John Wiley & Sons, Ltd.
Raman spectroscopic identification of fullerene inclusions in polymer/fullerene blends
Authors: Falke Sarah , Eravuchira Pinkie , Materny Arnulf , Lienau Christoph 
Published: May 2011

AbstractThin films of the conjugated polymer poly(3‐hexylthiophene) (P3HT) and blends of the soluble fullerene derivative[6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) with P3HT—a well studied but not completely understood donor–acceptor system for organic solar cells—have been studied by means of UV–visible absorption and resonant Raman spectroscopy. Additionally, we have employed atomic force microscopy phase imaging to characterize the nanomorphology of the P3HT : PCBM thin film, revealing a close intermixing of two phases with domain sizes ranging from a few to several tens of nanometers. A systematic analysis of pristine polymer and blend Raman spectra provides evidence that features attributable to PCBM, possibly even depending on the charge state of the fullerene molecule, can be observed. Hence our results suggest that fullerene inclusions in polymer/fullerene blends can be identified via Raman spectroscopy. Copyright © 2011 John Wiley & Sons, Ltd.
Elk parturition site selection at local and landscape scales
Authors: Barbknecht Andrea E. , Fairbanks W. Sue , Rogerson Jared D. , Maichak Eric J. , Scurlock Brandon M. , Meadows Laura L. 
Published: May 2011

AbstractSelection of habitat components by ungulates associated with parturition sites varies among and within species depending upon vulnerability to predators, variation in local topography and climate regimes, and the length of time that the maternal–neonatal unit spends at or near the parturition location. We marked 169 parturition locations of elk (Cervus elaphus nelsoni) in western Wyoming using vaginal implant transmitters and evaluated parturition‐specific habitat selection at macro‐ and microhabitat scales using a resource selection function modeling approach. Elk calved in a variety of habitats, yet demonstrated selection at both spatial scales. We found the strongest support for models that incorporated multiple habitat features and focused on topographical and vegetative cover types that provide physical and thermal cover at the macrohabitat scale and for visual cover models at the microhabitat scale. Models based solely on forage availability or quality were least supported at both scales, which may be indicative of a brief occupation of the parturition location or low heterogeneity in the availability of forage resources on parturition ranges. Results of early elk natural history studies may have represented a bias introduced by variable sightability and accessibility of females with calves and a lack of differentiation between calving and neonatal periods. More clearly defining calving site selection and removing biases toward more open habitats where sightability of neonates is greater may be used by wildlife or land managers to improve or protect calving habitats, which is often a stated objective of management actions. The results of this study suggest that microhabitat is more important to elk and that temporal closures over broad areas versus closures focused on specific macrohabitats may be more effective in protecting calving animals. © 2011 The Wildlife Society.