bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enzymatic Synthesis of Poly(α‐ethyl β‐aspartate) by Poly(ethylene glycol) Modified Poly(aspartate) Hydrolase‐1
Authors: Hiraishi Tomohiro , Masuda Eriko , Miyamoto Daisuke , Kanayama Naoki , Abe Hideki , Maeda Mizuo 
Published: October 2010

AbstractWe recently discovered that poly(aspartate) (PAA) hydrolase‐1 from Pedobacter sp. KP‐2 has a unique property of specifically cleaving the amide bond between β‐aspartate units in thermally synthesized PAA (tPAA). In the present study, the enzymatic synthesis of poly(α‐ethyl β‐aspartate) (β‐PAA) was performed by taking advantage of the substrate specificity of PAA hydrolase‐1. No polymerization of diethyl L‐aspartate by native PAA hydrolase‐1 occurred because of the low dispersibility of the enzyme in organic solvent. Poly(ethylene glycol) (PEG) modification of the enzyme improved its dispersibility and enabled it to polymerize the monomer substrate. MALDI‐TOF MS analysis showed that the synthesized polymer was observed in the range of m/z = 750–2 500. This analysis also revealed that the polymer was composed of ethyl aspartate units, containing either an ethyl ester or a free carboxyl end group at its carboxyl terminus. 1H NMR analysis demonstrated that the synthesized polymer consisted of only β‐amide linkages. Thus, the present results indicate that PAA hydrolase‐1 modified with PEG is useful for the synthesis of β‐PAA due to its unique substrate specificity and good dispersibility in organic solvent.
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The Synthesis of a Multiblock Osteotropic Polyrotaxane by Copper(I)‐Catalyzed Huisgen 1,3‐Dipolar Cycloaddition
Authors: Hein Christopher D. , Liu Xin‐Ming , Chen Fu , Cullen Diane M. , Wang Dong 
Published: October 2010

AbstractThe design and synthesis of a novel bone‐targeting polyrotaxane delivery system that utilizes alendronate (ALN) as targeting moiety is presented in this manuscript. For the introduction of ALN, it is first conjugated to α‐cyclodextrin (α‐CD) and subsequently threaded onto a short poly(ethylene glycol) (PEG) chain, forming a pseudopolyrotaxane. Using click chemistry, this assembly is copolymerized with bulky monomers that bear imaging and/or therapeutic agent(s) to prevent ALN‐functionalized α‐CD from dethreading. Overall bone affinity of this novel polymer conjugate can be easily controlled by changing the number of ALN‐α‐CD incorporated. The osteotropicity of the delivery system was also confirmed in vivo.
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Evoked local field potentials can explain temporal variation in blood oxygenation level‐dependent responses in rat somatosensory cortex
Authors: Huttunen Joanna K. , Niskanen Juha‐Pekka , Lehto Lauri J. , Airaksinen Antti M. , Niskanen Eini I. , Penttonen Markku , Gröhn Olli 
Published: October 2010

AbstractThe aim of this study was to explain the temporal variations between subjects in the blood oxygenation level‐dependent (BOLD) response. Somatosensory responses were elicited with the electrical forepaw stimulus at a frequency of 10 Hz in urethane‐anesthetized rats, and functional magnetic resonance imaging (fMRI) with BOLD contrast and local field potential (LFP) measurements were performed simultaneously. BOLD fMRI activation was evaluated by two different models, one based on the stimulus paradigm (the block model) and the other on the simultaneously measured evoked LFP responses. In the initial analysis, the LFP model captured the BOLD activation in the primary somatosensory cortex in all cases, and the block model in 10 of 12 rats. A statistical comparison of the two models revealed that the LFP‐derived model was able to explain additional BOLD variation over the block model in the somatosensory cortex in nine of 12 rats. These results suggest that there is more information regarding neuronal activity in the BOLD signal than can be exploited using the block model alone. Furthermore, the hemodynamic coupling remains unchanged in the case of temporally variable BOLD signals. Copyright © 2010 John Wiley & Sons, Ltd.
A comparison of single‐voxel clinical in vivo hepatic 31P MR spectra acquired at 1.5 and 3.0 Tesla in health and diseased states
Authors: Wylezinska Marzena , Cobbold Jeremy F.L. , Fitzpatrick Julie , McPhail Mark J.W. , Crossey Mary M.E. , Thomas Howard C. , Hajnal Joseph V. , Vennart William , Cox I. Jane , Taylor‐Robinson Simon D. 
Published: October 2010

AbstractWith the increasing availability of human MR scanners at various field strengths, the optimal field strength for in vivo clinical MR studies of the liver has become a focus of attention. Comparison between results at 3.0 and 1.5 T is of particular clinical interest, especially for multicentre studies. For MRS studies, higher field strengths should be advantageous, because improved sensitivity and chemical shift dispersion are expected. We report a comparison between single‐voxel hepatic proton‐decoupled 31P MRS performed at 1.5 and 3.0 T in the same subjects using similar methodologies. Twelve healthy volunteers and 15 patients with chronic liver disease were studied. Improved spectral resolution was achieved using proton decoupling, and there was an improvement (21%) in the signal‐to‐noise ratio (SNR) of the phosphomonoester (PME) resonance at 3.0 T relative to 1.5 T. There was no significant change in nuclear Overhauser effects for PME or phosphodiesters (PDEs) between the two field strengths. The T1 value of PDE was significantly longer at 3 T, although there was no significant change in the T1 value of PME. There was no significant difference in the mean PME/PDE ratios for either the control or patient groups at both 1.5 and 3.0 T, but there was a small positive mean difference in PME/PDE at 3.0 T on pairwise testing between field strengths (+ 0.05, p < 0.01). There were significant correlations between PME/PDE values at the two magnetic field strengths (r = 0.806, p < 0.001). The underlying broad resonance was reduced at 3.0 T relative to 1.5 T, related to line broadening of the phospholipid bilayer signal. In conclusion, there was an improvement in hepatic 31P MR signal quality at 3.0 T relative to 1.5 T. Broadly similar hepatic 31P MR parameters were obtained at 1.5 and 3.0 T. The modest difference noted in the PME/PDE ratio between field strengths for patients with chronic liver disease should inform multicentre study design involving these field strengths. Copyright © 2010 John Wiley & Sons, Ltd.
Filtering spam from bad neighborhoods
Authors: van Wanrooij Ward , Pras Aiko 
Published: October 2010

AbstractOne of the most annoying problems on the Internet is spam. To fight spam, many approaches have been proposed over the years. Most of these approaches involve scanning the entire contents of e‐mail messages in an attempt to detect suspicious keywords and patterns. Although such approaches are relatively effective, they also show some disadvantages. Therefore an interesting question is whether it would be possible to effectively detect spam without analyzing the entire contents of e‐mail messages. The contribution of this paper is to present an alternative spam detection approach, which relies solely on analyzing the origin (IP address) of e‐mail messages, as well as possible links within the e‐mail messages to websites (URIs). Compared to analyzing suspicious keywords and patterns, detection and analysis of URIs is relatively simple. The IP addresses and URIs are compared to various kinds of blacklists; a hit increases the probability of the message being spam. Although the idea of using blacklists is well known, the novel idea proposed within this paper is to introduce the concept of ‘bad neighborhoods’. To validate our approach, a prototype has been developed and tested on our university's mail server. The outcome was compared to SpamAssassin and mail server log files. The result of that comparison was that our prototype showed remarkably good detection capabilities (comparable to SpamAssassin), but puts only a small load on the mail server. Copyright © 2010 John Wiley & Sons, Ltd.
The complexity of pancreatic ductal cancers and multidimensional strategies for therapeutic targeting
Authors: Kern Scott E , Shi Chanjuan , Hruban Ralph H 
Published: October 2010

AbstractThe directions of differentiation and the molecular features of ductal pancreatic cancer have by now been explored in reasonable detail. Already, diagnoses and therapeutic strategies benefit from observations distinguishing the major variant types of pancreatic cancer and the differing stages of disease at presentation. Additionally, individual patients differ within each variant type. In certain high‐risk groups, this permits focused screening efforts. The tumorigenic influences that characterize individual patients are increasingly considered appropriate in defining clinical treatment plans. As a result, multiple variables affect success when individualizing screening or therapy. These competing variables often limit the potential for success: some variables dominate and should receive greater consideration than others. Simplistic expectations, often falsely optimistic, for individualized care may fail to ‘pan out’ in the real world. The development of individualized care will be efficient only when the full complexity of the disease is embraced. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Analysis of secondary ultrasound markers in the first trimester before chorionic villus sampling
Authors: Molina García Francisca S. , Carrillo Badillo María Paz , Zaragoza García Edgar A. , Fernández de Santos Aránzazu Garrote , Montoya Ventoso Francisco 
Published: October 2010

AbstractObjectiveTo evaluate detection and false‐positive rates of the ultrasound markers—nasal bone (NB), ductus venosus (DV) flow and tricuspid regurgitation (TR)—during the first trimester in a population at high genetic risk, and to study the influence of a two‐stage screening policy alter previous combined screening on the rate of invasive procedures.MethodsA total of 333 chorionic villus samples were obtained in singleton pregnancies. Before biopsy, the ultrasound markers—NB, DV, and TR—were assessed, although the findings were not used to recalculate the previously determined risk for Down syndrome.ResultsDetection and false‐positive rates for Down syndrome were 63.2% and 3.4% for NB, 65% and 3.1% for DV, and 50% and 2.1% for TR. All three markers were normal in 30% [84/277, 95% confidence interval (CI) 25%–36%] of chorionic villus sampling (CVS) cases performed for abnormal findings at the first trimester genetic screen, with 0% (0/20, 95% CI 0%–17%) false‐negative rate for Down syndrome.ConclusionAssessment of secondary ultrasound markers is feasible in clinical practice and their use could reduce the number of unnecessary invasive procedures by 30%. Copyright © 2010 John Wiley & Sons, Ltd.
Molecular diagnosis of Down syndrome using quantitative APEX‐2 microarrays
Authors: Oitmaa Eneli , Peters Maire , Vaidla Kadri , Andreson Reidar , Mägi Reedik , Slavin Georgi , Velthut Agne , Tõnisson Neeme , Reimand Tiia , Remm Maido , Schneider Marion , Õunap Katrin , Salumets Andres , Metspalu Andres 
Published: October 2010

AbstractObjectiveTo develop a new rapid and high‐throughput microarray‐based prenatal diagnostic test for the detection of trisomy 21 (T21).MethodsThe T21 arrayed primer extension‐2 (APEX‐2) assay discriminates between trisomy and euploid DNA samples by comparing the signal intensities of allelic fractions of heterozygous single nucleotide polymorphisms (SNPs) after APEX reaction. After preliminary validation using DNA samples from Down syndrome patients, we analyzed DNA samples from cultured and uncultured amniocytes and chorionic villus for 90 SNPs with high heterozygosity from the 21(q21.1q22.2) region. Differences in allelic ratios of heterozygous SNPs in normal and T21 individuals were verified by t‐test.ResultsAnalysis of the T21 APEX‐2 assay results revealed that 90 SNPs were sufficient for reliable discrimination between T21 and euploid DNA samples (P⩽0.05 for one or both strands). Using 134 clinical samples from cultured or uncultured fetal cells, both the sensitivity and the specificity of the assay were 100%.ConclusionOur study provides a proof of principle demonstration of the use of the modified APEX‐2 assay as a new, fast and reliable method for prenatal diagnosis of fetal T21. Copyright © 2010 John Wiley & Sons, Ltd.
The impact of ageing and changing utilization patterns on future cardiovascular drug expenditure: a pharmacoepidemiological projection approach
Authors: Kildemoes Helle Wallach , Andersen Morten , Støvring Henrik 
Published: October 2010

AbstractPurposeTo develop a method for projecting the impact of ageing and changing drug utilization patterns on future drug expenditure.MethodsApplying nationwide registries, prescriptions of three categories of cardiovascular drugs were followed for all Danish residents from 1 January 1996 until 2006. The official Danish population forecast 2006–2015 was applied for projecting the population composition.A previously developed pharmacoepidemiological semi‐Markov model was extended to apply for projection of future drug utilization. We either assumed that past trends in model parameters (incidence, discontinuation and drug user mortality) would continue during 2006–2015, or that all model parameters would remain unchanged at their values in 2005. Yearly drug expenditure per user of a particular drug was assumed to remain unchanged. Scenarios of future treatment prevalence with different drug categories were modelled by extrapolating future age‐ and gender‐specific parameter values (treatment incidence, discontinuation and drug user mortality) from historic point estimates and their historic trend.ResultsProvided a continuance of past trends, increasing utilization of ACE inhibitors, angiotensin II antagonists and statins translates into a rise in annual expenditure of 176%, mainly explained by increases in treatment incidence. Due to pharmacoepidemiological disequilibrium, unchanged model parameters would imply an increase of 64%, ageing alone 14%.ConclusionIncreasing cardiovascular drug utilization may pose a substantial burden on future health care resources. However, prescribing behaviour is likely to depend on changing clinical guidelines. Despite the limited impact as cost driver, population ageing remains a challenge for future health care services. Copyright © 2010 John Wiley & Sons, Ltd.
Intumescent flame retardation of melamine‐modified montmorillonite on polyamide 6: Enhancement of condense phase and flame retardance
Authors: Fang Keyi , Li Juan , Ke Chenhao , Zhu Qiliang , Tao Kang , Zhu Jin , Yan Qing 
Published: October 2010

AbstractMelamine‐modified montmorillonite (MA‐MMT) was prepared via cation exchange. The intercalation behavior was investigated by Fourier transform infrared spectrometer (FT‐IR), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). The results showed that the d‐spacing value increased from 1.25 nm for Na‐montmorillonite (Na+MMT) to 1.53 nm for MA‐MMT. Different kinds of montmorillonite combined with melamine pyrophosphate (MPP) were used to prepare flame‐retardant polyamide 6 (FR‐PA6). Flame retardance of FR‐PA6 samples was investigated by limiting oxygen index (LOI), UL‐94 vertical burning method, and cone calorimeter test. Morphology and component of char residues for FR‐PA6 were investigated by scanning electron microscope (SEM) and XPS. It was found that MA‐MMT/MPP system contributed both excellent flame retardance and anti‐dripping ability for PA6. MA‐MMT particles can fill flaws of char residues and strengthen the char layer, leading to form more intumescent char layer. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Synthesis of amphiphilic temperature‐sensitive poly(N‐isopropylacrylamide)‐block‐poly(tetramethylene carbonate) block copolymers and micellar characterization
Authors: Lee Ren‐Shen , Chen Wen‐Hsin 
Published: October 2010

AbstractAmphiphilic thermally sensitive poly(N‐isopropylacrylamide)‐block‐poly(tetramethylene carbonate) block copolymers were synthesized by ring‐opening polymerization of tetramethylene carbonate with hydroxyl‐terminated poly(N‐isopropylacrylamide) (PNiPAAm) as macro‐initiator in the presence of stannous octoate as catalyst. The synthesis involved PNiPAAm bearing a single terminal hydroxyl group prepared by telomerization using 2‐hydroxyethanethiol as a chain‐transfer agent. The copolymers were characterized using 1H NMR and Fourier transform infrared spectroscopy and gel permeation chromatography. Their solutions show reversible changes in optical properties: transparent below the lower critical solution temperature (LCST) and opaque above the LCST. The LCST depends on the polymer composition and the media. Owing to their amphiphilic characteristics, the block copolymers form micelles in the aqueous phase with critical micelle concentrations (CMCs) in the range 1.11–22.9 mg L−1. Increasing the hydrophobic segment length or decreasing the hydrophilic segment length in the amphiphilic diblock copolymers produces lower CMCs. A core‐shell structure of the micelles is evident from 1H NMR analyses of the micelles in D2O. Transmission electron microscopic analyses of micelle morphology show a spherical structure of both blank and drug‐loaded micelles. The blank and drug‐loaded micelles have an average size of less than 130 nm. Observations show high drug‐entrapment efficiency and drug‐loading content for the drug‐loaded micelles. Copyright © 2010 Society of Chemical Industry
Proteomic changes in maize roots after short‐term adjustment to saline growth conditions
Authors: Zörb Christian , Schmitt Sigrid , Mühling Karl H. 
Published: October 2010

AbstractIt is of fundamental importance to understand adaptation processes leading to salt resistance. The initial effects on maize roots in the first hour after the adjustment to saline conditions were monitored to elucidate initial responses. The subsequent proteome change was monitored using a 2‐D proteomic approach. We found several new salt‐inducible proteins, whose expression has not been previously reported to be modulated by salt. A set of phosphoproteins in maize was detected but only ten proteins were phosphorylated and six proteins were dephosphorylated after the application of 25 mM NaCl for 1 h. Some of the phosphorylated maize proteins such as fructokinase, UDP‐glucosyl transferase BX9, and 2‐Cys‐peroxyredoxine were enhanced, whereas an isocitrate‐dehydrogenase, calmodulin, maturase, and a 40‐S‐ribosomal protein were dephosphorylated after adjustment to saline conditions. The initial reaction of the proteome and phosphoproteome of maize after adjustment to saline conditions reveals members of sugar signalling and cell signalling pathways such as calmodulin, and gave hint to a transduction chain which is involved in NaCl‐induced signalling. An alteration of 14‐3‐3 proteins as detected may change plasma membrane ATPase activity and cell wall growth regulators such as xyloglucane endotransglycosylase were also found to be changed immediately after the adjustment to salt stress.
Comparative proteomic profiling of culture filtrate proteins of less and highly virulent Francisella tularensis strains
Authors: Konecna Klara , Hernychova Lenka , Reichelova Marketa , Lenco Juraj , Klimentova Jana , Stulik Jiri , Macela Ales , Alefantis Tim , DelVecchio Vito G. 
Published: October 2010

AbstractThe facultative intracellular bacterium Francisella tularensis is the causal agent of the serious infectious disease tularemia. Despite the dynamic progress, which has been made in last few years, important questions regarding Francisella pathogenicity still remain to be answered. Generally, secreted proteins play an important role in pathogenicity of intracellular microbes. In this study, we investigated the protein composition of the culture filtrate proteins of highly virulent F. tularensis subsp. tularensis, strain SCHU S4 and attenuated F. tularensis subsp. holarctica, live vaccine strain using a comparative proteomic analysis. The majority of proteins identified in this study have been implicated in virulence mechanisms of other pathogens, and several have been categorized as having moonlighting properties; those that have more than one unrelated function. This profiling study of secreted proteins resulted in the unique detection of acid phosphatase (precursor) A (AcpA), β‐lactamase, and hypothetical protein FTT0484 in the highly virulent strain SCHU S4 secretome. The release of AcpA may be of importance for F. tularensis subsp. tularensis virulence due to the recently described AcpA role in the F. tularensis escape from phagosomes.
Comparative proteomic analysis of biofilm and planktonic cells of Neisseria meningitidis
Authors: van Alen Tessa , Claus Heike , Zahedi René P. , Groh Janos , Blazyca Heinrich , Lappann Martin , Sickmann Albert , Vogel Ulrich 
Published: October 2010

AbstractNeisseria meningitidis is a commensal of the human nasopharynx occasionally causing invasive disease. In vitro biofilms have been employed to model meningococcal carriage. A proteomic analysis of meningococcal biofilms was conducted and metabolic changes related to oxygen and nutrient limitation and upregulation of proteins involved in ROS defense were observed. The upregulated MntC which protects against ROS was shown to be required for meningococcal biofilm formation, but not for planktonic growth. ROS‐induced proteomic changes might train the biofilm to cope with immune effectors.
Plasma profiles in active systemic juvenile idiopathic arthritis: Biomarkers and biological implications
Authors: Ling Xuefeng B. , Park Jane L. , Carroll Tanya , Nguyen Khoa D. , Lau Kenneth , Macaubas Claudia , Chen Edward , Lee Tzielan , Sandborg Christy , Milojevic Diana , Kanegaye John T. , Gao Susanna , Burns Jane , Schilling James , Mellins Elizabeth D. 
Published: October 2010

AbstractSystemic juvenile idiopathic arthritis (SJIA) is a chronic arthritis of children characterized by a combination of arthritis and systemic inflammation. There is usually non‐specific laboratory evidence of inflammation at diagnosis but no diagnostic test. Normalized volumes from 89/889 2‐D protein spots representing 26 proteins revealed a plasma pattern that distinguishes SJIA flare from quiescence. Highly discriminating spots derived from 15 proteins constitute a robust SJIA flare signature and show specificity for SJIA flare in comparison to active polyarticular juvenile idiopathic arthritis or acute febrile illness. We used 7 available ELISA assays, including one to the complex of S100A8/S100A9, to measure levels of 8 of the15 proteins. Validating our DIGE results, this ELISA panel correctly classified independent SJIA flare samples, and distinguished them from acute febrile illness. Notably, data using the panel suggest its ability to improve on erythrocyte sedimentation rate or C‐reactive protein or S100A8/S100A9, either alone or in combination in SJIA F/Q discriminations. Our results also support the panel's potential clinical utility as a predictor of incipient flare (within 9 wk) in SJIA subjects with clinically inactive disease. Pathway analyses of the 15 proteins in the SJIA flare versus quiescence signature corroborate growing evidence for a key role for IL‐1 at disease flare.