bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonenzymatic Amperometric Glucose Sensor Based on Nanoporous Gold/Ruthenium Electrode
Authors: Shim Jun Ho , Cha Areum , Lee Youngmi , Lee Chongmok 
Published: July 2011

AbstractNanoporous gold/ruthenium (npAu‐Ru) nanocomposite catalysts were synthesized by the incorporation of Ru on npAu, which exhibited reasonable nonenzymatic glucose sensing characteristics with good sensitivity and selectivity. The structure and electrocatalytic activities of the npAu and npAu‐Ru catalysts were characterized by transmission electron microscopy, energy dispersive X‐ray spectroscopy and linear sweep voltammetry. To examine the detection of glucose, npAu and npAu‐Ru were loaded on a glassy carbon electrode with chitosan (CHIT) as capping agent for the nanocomposites, GC/npAu/CHIT and GC/npAu‐Ru/CHIT electrode, respectively. The GC/npAu‐Ru/CHIT electrode showed six fold higher sensitivity (240 µA mM−1 cm−2 for the linear dynamic range) for amperometric glucose detection than the GC/npAu/CHIT electrode. This could be attributed to the incorporation of Ru. Moreover the GC/npAu‐Ru/CHIT electrode displayed selectivity for glucose over biological interferents, including ascorbic acid and uric acid.
Evaluation of clarithromycin lactobionate as a novel chiral selector for enantiomeric separation of basic drugs in capillary electrophoresis
Authors: Yu Tao , Du Yingxiang , Chen Bin 
Published: July 2011

AbstractNowadays, macrocyclic antibiotics are presenting an increasing number of enantioseparation applications. The macrocyclic antibiotics used as chiral selectors in capillary electrophoresis (CE) include the ansamycins and the glycopeptides. The macrolides, another important class of macrocyclic antibiotics, have been reported as a new type of chiral selectors recently. In this study, clarithromycin lactobionate (CL), belonging to the group of macrolide antibiotics, was first investigated for its potential as a novel chiral selector in CE for enantiomeric separation of several basic drugs. As observed, CL allowed excellent separation of the enantiomers of metoprolol, atenolol, propranolol, bisoprolol, esmolol, ritodrine, and amlodipine, as well as partial enantioresolution of labetalol and nefopam. In addition, CL possesses advantages such as high solubility and low viscosity in the solvent and very weak UV absorption. In the course of this study, it was found that both migration times and enantioseparation of the basic drugs were influenced by several experimental parameters, e.g. selector concentration, the composition and pH of the BGE, the type and concentration of organic modifier, and applied voltage. Thus, the effects of these factors were systematically investigated, and satisfactory enantioseparations of the studied drugs were achieved at the buffer pH range of 7.3–7.5 using 12.5 mM borax buffer with 50% v/v methanol, 60 mM CL, and 20 kV applied voltage. Moreover, comparison of the influences of the studied parameters was further investigated by means of Statistical Product and Service Solutions (SPSS) in this article.
In‐line preconcentration capillary zone electrophoresis for the analysis of haloacetic acids in water
Authors: Bernad Josep O. , Damascelli Anna , Núñez Oscar , Galceran Maria T. 
Published: July 2011

AbstractTwo in‐line enrichment procedures (large volume sample stacking (LVSS) and field amplified sample injection (FASI)) have been evaluated for the CZE analysis of haloacetic acids (HAAs) in drinking water. For LVSS, separation on normal polarity using 20 mM acetic acid–ammonium acetate (pH 5.5) containing 20% ACN as BGE was required. For FASI, the optimum conditions were 25 s hydrodynamic injection (3.5 kPa) of a water plug followed by 25 s electrokinetic injection (−10 kV) of the sample, and 200 mM formic acid–ammonium formate buffer at pH 3.0 as BGE. For both FASI and LVSS methods, linear calibration curves (r2>0.992), limit of detection on standards prepared in Milli‐Q water (49.1–200 μg/L for LVSS and 4.2–48 μg/L for FASI), and both run‐to‐run and day‐to‐day precisions (RSD values up to 15.8% for concentration) were established. Due to the higher sensitive enhancement (up to 310‐fold) achieved with FASI‐CZE, this method was selected for the analysis of HAAs in drinking water. However, for an optimal FASI application sample salinity was removed by SPE using Oasis WAX cartridges. With SPE‐FASI‐CZE, method detection limits in the range 0.05–0.8 μg/L were obtained, with recoveries, in general, higher than 90% (around 65% for monochloroacetic and monobromoacetic acids). The applicability of the SPE‐FASI‐CZE method was evaluated by analyzing drinking tap water from Barcelona where seven HAAs were found at concentration levels between 3 and 13 μg/L.
Comparative analysis of CE‐SSCP to standard RFLP‐CE‐FLA method in quantification of known viral variants within an RNA virus quasispecies
Authors: Gulija Tanja Košutić , Ivancic‐Jelecki Jelena , Šantak Maja , Forcic Dubravko 
Published: July 2011

AbstractRNA viruses display the highest replication error rate in our biosphere, leading to highly diverse viral populations termed quasispecies. The gold standard method for detection and quantification of variants in a quasispecies is cloning and sequencing, but it is expensive, laborious and time consuming. Therefore, other mutation detection approaches, including SSCP, are often used. In this study, we demonstrate development and the usage of a CE‐SSCP method for quantification of two nearly identical viral variants in heterogenic population of a mumps virus strain and its comparison to RFLP‐CE‐fragment length analysis (RFLP‐CE‐FLA). Analyzed PCR fragments were of the same size (245 bp) with one difference in their nucleotide sequence. The limit of detection of both methods was at 5% of the minor variant. When PCR amplicons of the two variants were pooled, methods' results were very similar. On the contrary, the quantification results of samples in which variants were mixed prior to PCR showed substantial difference between the two methods. Our results indicate that although both methods can be used for detection and monitoring of a specific mutation within a viral population, caution should be taken when quantitative analysis of complex samples is based solely on results of one method.
Proteins from Erwinia asparaginase Erwinase® and E. coli asparaginase 2 MEDAC® for treatment of human leukemia, show a multitude of modifications for which the consequences are completely unclear
Authors: Bae Narkhyun , Pollak Arnold , Lubec Gert 
Published: July 2011

AbstractL‐Asparaginase from Erwinia chrysanthemi (ASPG_ERWCH; UniProtKB accession number P06608 (Erwinase®)) and L‐asparaginase 2 from Escherichia coli (ASPG2_ECOLI; UniProtKB accession number P00805 (Medac®)), both L‐asparagine amidohydrolases, are widely used for the treatment of acute lymphoblastic leukemia. A series of serious side effects have been reported and this warrants studies into the protein chemistry of the medical products sold. Mass spectrometry (MS) data on ASPG_ERWCH and ASPG2_ECOLI have not been published so far and herein a gel‐based proteomics study was performed to provide information about sequence and modifications of the commercially available medical products. ASPG_ERWCH and ASPG2_ECOLI were applied onto two‐dimensional gel electrophoresis, spots were in‐gel digested with several proteases and resulting peptides and protein modifications were analysed by nano‐ESI‐LC‐MS/MS. Four spots were observed for ASPG_ERWCH, six spots were observed for ASPG2_ECOLI and the identified proteins showed high sequence coverage without sequence conflicts. Several protein modifications including technical and posttranslational modifications were demonstrated. Protein modifications are known to change physicochemical, immunochemical, biological and pharmacological properties and results from this work may challenge re‐designing of the product including possible removal of the modifications by the manufacturer because it is not known whether they are contributing to the serious adverse effects of the protein drug.
Analysis of phospholipids using an open‐tubular capillary column with a monolithic layer of molecularly imprinted polymer in capillary electrochromatography‐electrospray ionization‐tandem mass spectrometry
Authors: Jang Rin , Kim Ki Hun , Zaidi Shabi Abbas , Cheong Won Jo , Moon Myeong Hee 
Published: July 2011

AbstractIn this study, an open‐tubular capillary electrochromatography (OT‐CEC) column with a monolithic layer of molecularly imprinted polymer (MIP) based on methacrylic acid, ethylene glycol dimethacrylate, and 4‐styrenesulfonic acid was utilized for the simultaneous separation and characterization of phospholipid (PL) molecular structures by interfacing with electrospray ionization‐tandem mass spectrometry (ESI‐MS‐MS). Introducing an MIP‐based monolith along with charged species at the OT column made it possible to separate PL molecules based on differences in head groups and acyl chain lengths in CEC. For the interface of OT‐CEC with ESI‐MS‐MS, a simple nanospray interface utilizing a sheath flow was developed and the resulting OT‐CEC‐ESI‐MS‐MS was able to separate PL standards (phosphatidylserines, phosphatidylethanolamines, phosphatidylglycerols, phosphatidic acid, and lysophosphatidylglycerols). The developed method was applied to human urinary lipid extracts, and resulted in the separation and structural identification of 18 molecules by data‐dependent collision‐induced dissociation.
Spatial variability in the speciation and bioaccumulation of mercury in an arid subtropical reservoir ecosystem
Authors: Becker Jesse C , Groeger Alan W , Nowlin Weston H , Chumchal Matthew M , Hahn Dittmar 
Published: July 2011

Abstract
Patterns of spatial variation of mercury and methylmercury (MeHg) were examined in sediments and muscle tissue of largemouth bass (Micropterus salmoides) from Amistad International Reservoir, a large and hydrologically complex subtropical water body in the Rio Grande drainage. The distributions of both Hg and MeHg were compared with environmental and biological factors known to influence production of MeHg. The highest concentrations of total Hg (THg) in sediment were found in the Rio Grande arm of the reservoir, whereas MeHg was highest at sites in the Devils River arm and inundated Pecos River (often more than 3.0 ng/g). Conditions in the sediments of the Devils River arm and Pecos River channel were likely more favorable to the production of MeHg, with higher sediment porewater dissolved organic carbon, and porewater sulfate levels in the optimal range for methylation. Although the detection of different groups of sulfate-reducing bacteria by polymerase chain reaction (PCR) was generally correlated with MeHg concentrations, bacterial counts via fluorescent in situ hybridization (FISH) did not correlate with MeHg. A sample of 156 largemouth bass (&lt;30 cm) showed a spatial pattern similar to that of MeHg in sediments, where fish from the Devils River arm of the reservoir had higher muscle Hg concentrations than those collected in the Rio Grande arm. In 88 bass of legal sport fishing size (&gt;35 cm), 77% exceeded the 0.3 mg/kg U.S. Environmental Protection Agency screening value. This study shows that significant variation in sediment MeHg and biotic Hg concentration can exist within lakes and reservoirs and that it can correspond to variation in environmental conditions and Hg methylation. Environ. Toxicol. Chem. 2011;30:2300–2311. © 2011 SETAC
Hydrocarbon concentrations and patterns in free-ranging sea otters (Enhydra lutris) from British Columbia, Canada
Authors: Harris Kate A , Nichol Linda M , Ross Peter S 
Published: July 2011

Abstract
With oil pollution recognized as a major threat to British Columbia's recovering sea otter (Enhydra lutris) population, it is important to distinguish acute from chronic exposures to oil constituent groups in this marine mammal. Concentrations and patterns of alkanes and polycyclic aromatic hydrocarbons (PAHs) were determined in blood samples from 29 live-captured sea otters in two coastal areas of British Columbia, as well as in representative samples of their invertebrate prey. Hydrocarbon concentrations in sea otters were similar between areas and among age and sex classes, suggesting that metabolism dominates the fate of these compounds in sea otters. Biomagnification factors derived from PAH ratios in otter:prey supported this notion. Although some higher alkylated three- and four-ring PAHs appeared to biomagnify, the majority of PAHs did not. The apparent retention of alkyl PAHs was reflected in the composition of estimated sea otter body burdens, which provided an alternative way of evaluating hydrocarbon exposure. Alkyl PAHs made up 86 ± 9% of estimated body burdens (4,340 ± 2,950 µg), with no differences between males and females (p = 0.18). The importance of measuring both parent and alkyl PAHs is underscored by their divergent dynamics in sea otters, with ready depuration of parent PAHs (metabolized or excreted) by sea otters on the one hand and biomagnification of alkyl PAHs on the other. Environ. Toxicol. Chem. 2011;30:2184–2193. © 2011 SETAC
Telomere maintenance in wilms tumors: First evidence for the presence of alternative lengthening of telomeres mechanism
Authors: Venturini Lorenza , Daidone Maria Grazia , Motta Rosita , Collini Paola , Spreafico Filippo , Terenziani Monica , Piva Luigi , Radice Paolo , Perotti Daniela , Zaffaroni Nadia 
Published: July 2011

AbstractUnlimited proliferative potential is a hallmark of cancer, and can be achieved through the activation of telomere maintenance mechanisms (TMMs). Most tumors activate telomerase, but a significant minority, mainly of mesenchymal origin, uses a recombination‐based, alternative lengthening of telomeres (ALT) mechanism. We investigated the presence of ALT in 34 Wilms tumor (WT) samples from 30 patients by using two approaches: (i) the detection of ALT‐associated promyelocytic leukemia (PML) nuclear bodies (APBs) by combined PML immunofluorescence and telomere fluorescence in situ hybridization and (ii) the assessment of terminal restriction fragment (TRF) length distribution by pulsed field gel electrophoresis. In parallel, telomerase activity (TA) was determined by the telomeric repeat amplification protocol (TRAP) assay. Based on APB expression, ALT was detectable in five samples as the sole TMM and in six samples in association with telomerase. Seventeen samples only expressed TA and in six cases no known TMM was appreciable. Results of TRF length distribution were available in 32 cases, and a concordance between APB and TRF data in defining the ALT phenotype was found in 26/32 cases (81%). The study provides the first evidence of the presence of ALT in WT, and indicates that in a small but defined fraction of cases (about 15%) ALT is the only TMM that supports the development of WT. © 2011 Wiley‐Liss, Inc.
Motor neuron impairment mediated by a sumoylated fragment of the glial glutamate transporter EAAT2
Authors: Foran Emily , Bogush Alexey , Goffredo Michael , Roncaglia Paola , Gustincich Stefano , Pasinelli Piera , Trotti Davide 
Published: July 2011

AbstractDysregulation of glutamate handling ensuing downregulation of expression and activity levels of the astroglial glutamate transporter EAAT2 is implicated in excitotoxic degeneration of motor neurons in amyotrophic lateral sclerosis (ALS). We previously reported that EAAT2 (a.k.a. GLT‐1) is cleaved by caspase‐3 at its cytosolic carboxy‐terminus domain. This cleavage results in impaired glutamate transport activity and generates a proteolytic fragment (CTE) that we found to be post‐translationally conjugated by SUMO1. We show here that this sumoylated CTE fragment accumulates in the nucleus of spinal cord astrocytes of the SOD1‐G93A mouse model of ALS at symptomatic stages of disease. Astrocytic expression of CTE, artificially tagged with SUMO1 (CTE‐SUMO1) to mimic the native sumoylated fragment, recapitulates the nuclear accumulation pattern of the endogenous EAAT2‐derived proteolytic fragment. Moreover, in a co‐culture binary system, expression of CTE‐SUMO1 in spinal cord astrocytes initiates extrinsic toxicity by inducing caspase‐3 activation in motor neuron‐derived NSC‐34 cells or axonal growth impairment in primary motor neurons. Interestingly, prolonged nuclear accumulation of CTE‐SUMO1 is intrinsically toxic to spinal cord astrocytes, although this gliotoxic effect of CTE‐SUMO1 occurs later than the indirect, noncell autonomous toxic effect on motor neurons. As more evidence on the implication of SUMO substrates in neurodegenerative diseases emerges, our observations strongly suggest that the nuclear accumulation in spinal cord astrocytes of a sumoylated proteolytic fragment of the astroglial glutamate transporter EAAT2 could participate to the pathogenesis of ALS and suggest a novel, unconventional role for EAAT2 in motor neuron degeneration. © 2011 Wiley‐Liss, Inc.
A stepped care relapse prevention program for depression in older people: a randomized controlled trial
Authors: Apil Sachlan R. A. , Hoencamp Erik , Judith Haffmans P. M. , Spinhoven Philip 
Published: July 2011

BackgroundThis study aimed to determine the feasibility and the effectiveness of a Stepped Care Program (SCP) for preventing relapse of depression in older people. Stepped care consisted of (1) watchful waiting; (2) bibliotherapy; (3) individual cognitive behavioral therapy; and (4) indicated treatment.MethodsIn a randomized controlled trial, persons 55 years and older (n = 136) who had suffered at least one episode of major depression in the past received a SCP or Care As Usual (CAU). The primary outcome measure was incidence of a new depressive episode.ResultsOf 1725 previously depressed persons, 175 were willing to partake in the study, 136 of whom were eligible. Treatment satisfaction for stepped care was high. At 12‐month follow‐up, no difference in incidence of depression between SCP and CAU was found. Medical patient records showed that missing data were often related to relapse.ConclusionsIn this study, SCP was not more effective in preventing relapse than CAU. Watchful waiting may harmfully delay actual preventive treatment. Prevention as an integral part of regular treatment might lead to higher participation rates. Copyright © 2011 John Wiley & Sons, Ltd.
Reliability and validity of the Chinese version of the neuropsychiatric inventory in mainland China
Authors: Wang Tao , Xiao Shifu , Li Xia , Wang Haihong , Liu Yuanyuan , Su Ning , Fang Yiru 
Published: July 2011

ObjectiveThe reliability and validity of the Chinese version of the neuropsychiatric inventory (CNPI) in patients with Alzheimer's disease (AD) have not been assessed in mainland China. We do the reliability and validity research about CNPI of mainland China in the present study.MethodsThe CNPI was administered to 219 caregivers of patients with AD. Each caregiver was retested 4 weeks after initial testing.ResultsThe Cronbach's α coefficient of the total symptom scale was 0.69. The Cronbach's α coefficient of the total caregiver distress subscale was 0.72. The Cronbach's α coefficient of the entire inventory was 0.82. The test–retest coefficients ranged from 0.66 to 0.98 (p < 0.001). Principal axis factoring analysis of the symptom subscale yielded a five‐factor solution, which contributed to 67.0% of the cumulative variance. Factor 1, which included aberrant motor behavior, hallucinations, delusion and irritability had the most significant contribution to the cumulative variance. Principal axis factoring analysis of the caregiver distress subscale also yielded a five‐factor solution, which contributed to 70.2% of the cumulative variance. Factor 1, which included depression, delusion, sleep/night behavior, aberrant motor behavior and irritability had the most significant contribution to the cumulative variance.ConclusionThis Chinese version of NPI is a reliable and valid tool for measuring neuropsychiatric disturbances in patients with AD. Copyright © 2011 John Wiley & Sons, Ltd.
Subjective memory impairment in older adults: aetiology, salience and help seeking
Authors: Begum Aysha , Morgan Craig , Chiu Chih‐Chiang , Tylee Andre , Stewart Robert 
Published: July 2011

BackgroundSubjective memory impairment (SMI) is one of the key symptoms with which people with early cognitive impairment may present to health services. However, little research has investigated how older people view the symptom, its salience and how often help is sought. The objectives were to investigate (a) factors associated with SMI, (b) salience of SMI in comparison with other symptoms and (c) help seeking for SMI.MethodA cross‐sectional survey was based in two Primary Care services in south London in which registered people aged 65+ were interviewed blind to the study objectives. Measurements included systematic ascertainment of SMI and other common symptoms/disorders. In each of these, concern and interference were quantified, and participants were asked to rank all reported symptoms/disorders in order of importance.ResultsOf 126 participants, any SMI was reported in 66.7%, and 31.0% reported SMI to a significant degree. SMI occupied a middling rank in terms of salience, being ranked as more concerning than angina, asthma, hypertension or a previous heart attack in around half of participants in whom these co‐occurred. However, only one participant with SMI had sought help from their GP, making it the least likely symptom to be reported.ConclusionSubjective memory impairment is common and appears to have functional and/or emotional significance for many older people. However, very few appear to seek medical attention for this symptom, which has implications for wider policy regarding prompt assessment and diagnosis of mild cognitive impairment or dementia. Copyright © 2011 John Wiley & Sons, Ltd.
A whole brain fMRI atlas generated via spatially constrained spectral clustering
Authors: Craddock R. Cameron , James G.Andrew , Holtzheimer Paul E. , Hu Xiaoping P. , Mayberg Helen S. 
Published: July 2011

AbstractConnectivity analyses and computational modeling of human brain function from fMRI data frequently require the specification of regions of interests (ROIs). Several analyses have relied on atlases derived from anatomical or cyto‐architectonic boundaries to specify these ROIs, yet the suitability of atlases for resting state functional connectivity (FC) studies has yet to be established. This article introduces a data‐driven method for generating an ROI atlas by parcellating whole brain resting‐state fMRI data into spatially coherent regions of homogeneous FC. Several clustering statistics are used to compare methodological trade‐offs as well as determine an adequate number of clusters. Additionally, we evaluate the suitability of the parcellation atlas against four ROI atlases (Talairach and Tournoux, Harvard‐Oxford, Eickoff‐Zilles, and Automatic Anatomical Labeling) and a random parcellation approach. The evaluated anatomical atlases exhibit poor ROI homogeneity and do not accurately reproduce FC patterns present at the voxel scale. In general, the proposed functional and random parcellations perform equivalently for most of the metrics evaluated. ROI size and hence the number of ROIs in a parcellation had the greatest impact on their suitability for FC analysis. With 200 or fewer ROIs, the resulting parcellations consist of ROIs with anatomic homology, and thus offer increased interpretability. Parcellation results containing higher numbers of ROIs (600 or 1,000) most accurately represent FC patterns present at the voxel scale and are preferable when interpretability can be sacrificed for accuracy. The resulting atlases and clustering software have been made publicly available at: http://www.nitrc.org/projects/cluster_roi/. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc