bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability of human telomere quadruplexes at high DNA concentrations
Authors: Kejnovská Iva , Vorlíčková Michaela , Brázdová Marie , Sagi Janos 
Published: August 2013

ABSTRACTFor mimicking macromolecular crowding of DNA quadruplexes, various crowding agents have been used, typically PEG, with quadruplexes of micromolar strand concentrations. Thermal and thermodynamic stabilities of these quadruplexes increased with the concentration of the agents, the rise depended on the crowder used. A different phenomenon was observed, and is presented in this article, when the crowder was the quadruplex itself. With DNA strand concentrations ranging from 3 µM to 9 mM, the thermostability did not change up to ∼2 mM, above which it increased, indicating that the unfolding quadruplex units were not monomolecular above ∼2 mM. The results are explained by self‐association of the G‐quadruplexes above this concentration. The ΔGo37 values, evaluated only below 2 mM, did not become more negative, as with the non‐DNA crowders, instead, slightly increased. Folding topology changed from antiparallel to hybrid above 2 mM, and then to parallel quadruplexes at high, 6–9 mM strand concentrations. In this range, the concentration of the DNA phosphate anions approached the concentration of the K+ counterions used. Volume exclusion is assumed to promote the topological changes of quadruplexes toward the parallel, and the decreased screening of anions could affect their stability. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 428–438, 2014.
Study of Carbon Dioxide Transport in a Samaria Aerogel Catalyst by High Field Diffusion NMR
Authors: Müller Robert , Zhang Suihua , Neumann Björn , Bäumer Marcus , Vasenkov Sergey 
Published: August 2013

AbstractPulsed field gradient (PFG) NMR employing a high magnetic field of 17.6 T was used to study self‐diffusion of carbon dioxide in alumina stabilized samaria aerogel, a promising porous catalyst for gas‐phase reactions. Such rare‐earth aerogels exhibit high porosity and surface area with active sites directly integrated into the pore framework. In the reported diffusion NMR studies, application of a high magnetic field was essential for obtaining sufficiently high signal‐to‐noise ratios under conditions of relatively low CO2 densities in the primarily mesoporous catalyst particles. The diffusion studies were performed with the catalyst that was formed into the following two types of samples: macroscopic monoliths and beds of particles with sizes around 200 μm. The sorbate diffusivity inside the monolith was compared with the corresponding diffusivity in the bed under conditions of fast exchange of CO2 between the particles and the interparticle voids of the bed. The two‐domain exchange model proposed by Kärger for zeolites was used to describe the latter diffusivity. The reported results are expected to be useful for elucidating an influence of possible transport limitations under reaction conditions in aerogel catalysts.
Use of High‐Sensitivity Troponin Assays Predicts Mortality in Patients With Normal Conventional Troponin Assays on Admission—Insights From a Meta‐Analysis
Authors: Chatterjee Saurav , Kim Jiwon , Dahhan Ali , Choudhary Gaurav , Sharma Satish , Wu Wen‐Chih 
Published: August 2013

AbstractBackgroundUse of high‐sensitivity troponin (hs‐Tn) assays can detect small levels of myocardial damage previously undetectable with conventional troponin (c‐Tn) assays. However, prognostic utility of these hs‐Tn assays in prediction of mortality remains unclear in the presence of nonelevated c‐Tn levels on admission. A systematic review and meta‐analysis was performed to assess mortality risk of patients with hs‐Tn elevations in the setting of normal c‐Tn levels.HypothesisPatients with hs‐Tn elevations with normal c‐Tn levels on admission blood samples, drawn to rule out acute coronary syndrome (ACS), have a higher mortality risk than those without hs‐Tn or c‐Tn elevations.MethodsA search was made of the PubMed, CENTRAL, EMBASE, CINAHL, EBSCO, and Web of Science databases. Studies evaluating patients with suspected ACS that reported mortality rates for those with elevated hs‐Tn levels but normal c‐Tn levels on admission were included. A random‐effects model was used to pool event rates, and data were reported in odds ratios (95% confidence interval).ResultsFour studies (N = 2033, mean age 64–75 years, 49%–70% male) revealed that nearly 32% of suspected ACS patients with normal c‐Tn levels on admission had elevated hs‐Tn levels. Elevated hs‐Tn levels conferred a significantly higher risk of all‐cause mortality vs normal hs‐Tn levels (odds ratio: 4.35, 95% confidence interval: 2.81‐6.73, P < 0.01), with negligible heterogeneity (I2 = 0%).ConclusionsElevation of hs‐Tn levels predicted a higher risk of mortality in patients with suspected ACS and may aid in the early identification of higher‐risk patients in this setting. Future studies are needed to investigate further optimal management strategies.
Bosentan Treatment Is Associated With Improvement of Right Ventricular Function and Remodeling in Chronic Thromboembolic Pulmonary Hypertension
Authors: Surie Sulaiman , Reesink Herre J. , Marcus J. Tim , van der Plas Mart N. , Kloek Jaap J. , Vonk‐Noordegraaf Anton , Bresser Paul 
Published: August 2013

AbstractBackgroundMedical pretreatment before pulmonary endarterectomy (PEA) can optimize right ventricular (RV) function and may improve postoperative outcome in high‐risk patients. Using cardiac magnetic resonance imaging (cMRI), we determined whether the dual endothelin‐1 antagonist bosentan improves RV function and remodeling in patients with chronic thromboembolic pulmonary hypertension (CTEPH) who waited for PEA.HypothesisWe hypothesized that medical therapy prior to PEA will be associated with improvements in RV remodeling and function.MethodsIn this pilot study, 15 operable CTEPH patients were randomly assigned to either bosentan (n = 8) or no bosentan (n = 7, control) for 16 weeks, next to “best standard of care.” Both before and after treatment, RV stroke volume index (RVSVI), RV ejection fraction (RVEF), RV mass, RV isovolumic relaxation time (rIVRT), leftward ventricular septal bowing (LVSB), and left ventricular ejection fraction (LVEF) were determined using cMRI.ResultsAfter 16 weeks, the change (Δ) from baseline (median [range]) in the studied cMRI parameters differed significantly between the bosentan group and the controls: Δ RVSVI: 6 [−4–11] vs 1 [−6–3] mL/m−2; Δ RVEF: 8 [−10–15] vs −4 [−7–5]%; Δ RV mass: −3 [−6–−2] vs 2 [−1–3] g/m−2; Δ rIVRT: −30 [−130–20] vs 10 [−30–30] msec; Δ LVSB: 0.03 [−0.03–0.13] vs −0.03[−0.08–0.04] cm−1; and Δ LVEF: 8 [−5–17] vs −2 [−14–2]% (all P < 0.05). The change from baseline in mean pulmonary artery pressure (−11 [−17–11] vs 5 [−6–21] mm Hg, P < 0.05) and 6‐minute walk distance (20 [3–88] vs −4 [−40–40] m, P < 0.05) also differed significantly.ConclusionsIn CTEPH, compared with control, treatment with bosentan for 16 weeks was associated with a significant improvement in cMRI parameters of RV function and remodelling.
Efficacy of Short‐Term High‐Dose Atorvastatin Pretreatment in Patients With Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention: A Meta‐analysis of Nine Randomized Controlled Trials
Authors: Liu Yangchun , Su Qiang , Li Lang 
Published: August 2013

AbstractBackgroundThe efficacy of short‐term high‐dose atorvastatin pretreatment in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) remains unclear. This meta‐analysis was undertaken to assess the efficacy of short‐term high‐dose atorvastatin pretreatment in patients with ACS undergoing PCI.HypothesisShort‐term high‐dose atorvastatin pretreatment may be beneficial in reducing major adverse cardiac events (MACEs) and improving myocardial blood flow in patients with ACS undergoing PCI.MethodsMEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were systematically reviewed for randomized controlled trials (RCTs) published up to March 2013, in which short‐term high‐dose atorvastatin pretreatment was compared with control for patients with ACS undergoing PCI. The primary outcome measure was the incidence of MACEs at 30 days. The meta‐analysis was performed with the fixed effect model or random‐effects model according to the heterogeneity. Meta‐analysis was performed by RevMan 5.0 software (Cochrane Collaboration, Copenhagen, Denmark).ResultsNine RCTs incorporating 952 patients met the inclusion criteria and were included in this meta‐analysis. Short‐term high‐dose atorvastatin pretreatment significantly reduced the incidence of MACEs at 30‐day follow‐up (risk ratio [RR] 0.39, 95% confidence interval [Cl]: 0.25 to 0.61, P < 0.001) and improved the final Thrombolysis in Myocardial Infarction (TIMI) flow grade (RR 1.08, 95% Cl: 1.02 to 1.14, P = 0.01) compared with controls. There were no significant differences in peak creatine kinase‐myocardial band and high‐sensitivity C‐reactive protein level post‐PCI between the 2 groups, though there were favorable trends related to statin use. As to the safety end points, no significant difference was observed in elevated liver aminotransferase level between short‐term high‐dose atorvastatin pretreatment and control groups (RR 1.36, 95% Cl: 0.67 to 2.74).ConclusionsThe use of short‐term high‐dose atorvastatin pretreatment is safe and significantly improves the final TIMI flow grade as well as reduces the 30‐day MACEs in ACS patients post‐PCI. This finding encourages the use of short‐term high‐dose atorvastatin pretreatment as an alternative for ACS patients undergoing PCI, but more high‐quality randomized clinical trials are still needed to confirm the long‐term efficacy and safety.
Functionalized Porphyrins as Red Fluorescent Probes for Metal Cations: Spectroscopic, MALDI‐TOF Spectrometry, and Doped‐Polymer Studies
Authors: Moura Nuno M. M. , Núñez Cristina , Santos Sérgio M. , Faustino M. Amparo F. , Cavaleiro José A. S. , Neves M. Graça P. M. S. , Capelo José Luis , Lodeiro Carlos 
Published: August 2013

AbstractInvited for this month’s cover are groups from the University of Aveiro and the University NOVA of Lisbon/Bioscope. The cover picture of the lighthouses of Barra (Aveiro) and Cabo Espichel (Lisbon) in Portugal represents the remarkable sensing ability of benzoporphyrin derivatives for Hg2+ metal ions. These systems have high potential for use as chromogenic and fluorogenic sensors. Read the full text of the article on page 1230.
QoS‐driven jointly optimal subcarrier pairing and power allocation for OFDM amplify‐and‐forward relay systems
Authors: Huang Gaofei , Tu Wanqing , Luo Liping , Zhang Ping , Zhang Guangchi , Qin Jiayin 
Published: August 2013

SUMMARYIn this paper, we investigate the quality‐of‐service (QoS) driven subcarrier pairing and power allocation for two‐hop amplify‐and‐forward OFDM relay systems. By integrating the concept of effective capacity, our goal is to maximize the system throughput subject to a given delay QoS constraint. We propose a jointly optimal subcarrier pairing and power allocation scheme, which can be implemented with two separate steps. First, pair the subcarriers over the source‐relay channel and relay‐destination channel by the descending order of the subcarriers’ channel gains. Second, by making use of the derived equivalent end‐to‐end channel gains of the subcarrier pairs, optimally allocate power over the subcarrier pairs, and then optimally partition the power of the subcarrier pairs between the source and the relay. The simulation results show that our proposed scheme can efficiently provide different levels of delay QoS guarantees, even if under stringent delay QoS constraints. The simulation results also verify that our proposed scheme shows significant superiorities over the other existing schemes. Copyright © 2013 John Wiley & Sons, Ltd.
Surface Mineralization of Cellulose by Metal Chloride – an Original Pathway for the Synthesis of Hierarchical Urchin and Needle Carpetlike TiO2 Superstructures
Authors: Nair G. Ranjith , Samdarshi Sanjoy K. , Boury Bruno 
Published: August 2013

AbstractA new pathway has been developed for the preparation of hierarchical TiO2 structures obtained “with‐and‐from” the surface of cotton. By reaction with TiCl4 under anhydrous conditions, mineralization of the outer part of the cotton fiber produces hierarchical TiO2 superstructures: at the nanoscale, anatase needles are made of nanorod assemblies and these needles are assembled into urchins and carpets at the submicrometer scale. This one‐step cotton fiber cellulose mineralization process differs from a simple deposition from inorganic sol; here, cellulose acts as both a reacting oxygen donor and also as a biotemplate. The material has high‐temperature crystal stability, and its photocatalytic activity in the UV range, without any doping, is higher than that of titania standard P25. The high photoactivity is ascribed to efficient light harvesting by hierarchical superstructures, efficient charge separation with reduced recombination in the crystalline material, and efficient sorption ability. From a general standpoint, our findings could be adapted to other metal oxides and pave the way to a number of solar‐cell, energy‐storage, and photonic‐sensor applications.
Biotechnology for the functional improvement of cereal‐based materials enriched with PUFA and pigments
Authors: Čertík Milan , Klempová Tatiana , Guothová Lucia , Mihálik Daniel , Kraic Ján 
Published: August 2013

Cereals as the major food supply are deficient in essential nutrients, such as PUFA and pigments. Biotechnological techniques based on solid state fermentation (SSF) and genetic engineering have been developed to naturally prepare functional cereals enriched with PUFAs and carotenoids. SSF represents a promising approach where the selected fungi (Zygomycetes) effectively utilize and transform raw cereal substrates to cereal‐based bioproducts containing high amounts of valuable PUFAs and carotenoids. Depending on the strain, types of cereal substrates, and cultivation conditions, a range of cereal‐based bioproducts enriched with PUFAs (up to 2.4% GLA, 4.2% AA, 2.1% dihomo‐gamma/linolenic acid, 2.3% eicosapentaenoic acid) and pigments (8.5 mg beta‐carotene/kg prefermented cereals) have been prepared. In addition, cereals (barley, wheat) consisting of gamma‐linolenic and stearidonic acids have been prepared by genetic transformation of the fungal fatty acid Δ6‐desaturase gene. Such functional prefermented cereal‐based bioproducts are characterized by the acceptable nutritive, functional, and flavor values, the improved antioxidant, radical‐scavenging, and thermal oxidation properties as well as the enhanced safety; therefore they may find applications in the food/feed fields.Practical applications: Cereals lack a number of nutrients, such as PUFAs and pigments which are essential for human well‐being due to their healthy, dietary, and functional properties. However, cereals could be considered as challenging sources of these compounds if they are naturally modified with the aim to contain PUFAs and pigments. Therefore the biotechnological preparation of cereals enriched with PUFAs and carotene pigments by fungal SSF has been developed. This natural technique is promising for the application of prefermented “bioproducts” in various fields and such cereal materials enriched with PUFAs and carotenoids might be considered as new types of inexpensive functional cereal‐based food and feed supplements.
A Second‐Generation Tandem Ring‐Closing Metathesis Cleavable Linker for Solid‐Phase Oligosaccharide Synthesis
Authors: de Jong Ana R. , Volbeda Anne G. , Hagen Bas , van den Elst Hans , Overkleeft Herman S. , van der Marel Gijsbert A. , Codée Jeroen D. C. 
Published: August 2013

AbstractA tandem ring‐closing metathesis cleavable linker system for solid‐phase oligosaccharide synthesis has been developed. The acid‐ and base‐stable linker can be readily cleaved with Grubbs second‐generation catalyst without the use of alkene additives to liberate the assembled oligosaccharides from the solid support. Application of the linker was shown in three solid‐phase oligosaccharide synthesis campaigns. Two frame‐shifted hyaluronic acid fragments were prepared, and we also report the synthesis of a trimeric β‐1,3‐glucan fragment, in which, next to the linker, our recently reported 4‐azido‐2,2‐dimethylbutanoyl (AzDMB) protective group was applied.
Fabrication of an Electrochemical L‐Cysteine Sensor Based on Graphene Nanosheets Decorated Manganese Oxide Nanocomposite Modified Glassy Carbon Electrode
Authors: Majd Samira Mansouri , Teymourian Hazhir , Salimi Abdollah 
Published: August 2013

AbstractThe graphene nanosheets/manganese oxide nanoparticles modified glassy carbon electrode (GC/GNSs/MnOx) was simply prepared by casting a thin film of GNSs on the GC electrode surface, followed by performing electrodeposition of MnOx at applied constant potential. The GC/GNSs/MnOx modified electrode shows high catalytic activity toward oxidation of L‐cysteine. Hydrodynamic amperometry determination of L‐cysteine gave linear responses over a concentration range up to 120 µM with a detection limit of 75 nM and sensitivity of 27 nA µM−1. The GC/GNSs/MnOx electrode appears to be a highly efficient platform for the development of sensitive, stable and reproducible L‐cysteine electrochemical sensors.
1,4‐Michael Addition – The Analytical Way for Quantitative Sensing of Neurotransmitter at Bare Gold Electrode in Physiological Solution in the Presence of Interfering Biogenic Compounds
Authors: Łuczak Teresa 
Published: August 2013

AbstractElectrooxidation of norepinephrine in the presence a nucleophile was investigated on a bare gold electrode. Electrochemically produced norepinephrinequinone undergoes an attack by morpholine as nucleophile via 1,4‐Michael addition. The reaction products were identified by electrospray ionization mass spectrometry. The procedure used was suitable for quantitative norepinephrine determination in the concentration range from 1×10−9 M to 8×10−4 M with a detection limit of 8.7×10−10 M in a samples containing an excess of ascorbic and uric acids. The proposed method is simple, green which means that it does not require the use of toxic compounds and solvents and thus is promising for detection of norepinephrine in physiological environment.
Climate‐related variations in atmospheric Sb and Tl in the EPICA Dome C ice (East Antarctica) during the past 800,000 years
Authors: Hur Soon Do , Soyol‐Erdene Tseren‐Ochir , Hwang Hee Jin , Han Changhee , Gabrielli Paolo , Barbante Carlo , Boutron Claude F. , Hong Sungmin 
Published: August 2013

AbstractA record of antimony (Sb) and thallium (Tl) from the European Project for Ice Coring in Antarctica (EPICA) Dome C Antarctic ice core provides the characteristics of climate‐related natural changes in concentrations and fluxes of these toxic elements over the time period back to Marine Isotope Stage 20.2, ~800 kyr B.P. A strong variability in concentrations and fluxes are observed for both elements, with considerably higher values during glacial maxima and lower values during intermediate and warm periods. Rock and soil dust accounts for, on average, 58% of Sb and 76% of Tl in ice during glacial maxima. This contribution remains significant during warm periods, accounting for 21% for Sb and 27% for Tl. The contribution from volcanoes appears to be very important particularly for Tl when climatic conditions become warmer, with an estimated volcanic contribution of 72% for Tl during interglacials. The sea‐salt contribution is significant for Sb, particularly during intermediate climatic periods, with an average contribution of 17%. This sea‐salt contribution is most likely caused by greater production of sea salt from highly saline frost flowers and relatively more efficient transport of Sb‐enriched sea‐ice salt from source areas on the East Antarctic Plateau. Our ice core data, along with snow data recently reported from the Antarctic snow layers at Dome Fuji, shows that the present‐day Sb flux (6.6 ng/m2/yr) is approximately double the highest natural level (2.8 ng/m2/yr) during glacial maxima throughout the last successive eight glacial/interglacial cycles. This result indicates that human activity has induced the greatest perturbation of the atmospheric cycle of Sb ever experienced over a period of ~800 kyr in the most remote area on Earth.
The effects of reflected protons on the plasma environment of the moon for parallel interplanetary magnetic fields
Authors: Halekas J. S. , Poppe A. R. , McFadden J. P. , Glassmeier K.‐H. 
Published: August 2013

AbstractFor the unique case of magnetic field parallel to the solar wind flow, a column of reflected protons can accumulate upstream from the Moon. We investigate observations from the ARTEMIS probes for an extended period with this geometry. During this time, P2 observes strong wave turbulence in two frequency bands above and below the ion cyclotron frequency near the Moon, not seen by P1 farther from the Moon. The lower frequency oscillations prove consistent with kinetic magnetosonic waves resonantly generated by reflected protons, and test particle calculations confirm that a significant column of reflected protons lies upstream when the waves occur. The reflected protons perturb a large volume of plasma around the Moon, extending upstream as well as into the wake. The waves observed near the Moon during this time period have many similarities to those found in the terrestrial foreshock and at comets, suggesting the potential for comparative studies.
The Effect of the Cathepsin K Inhibitor ONO-5334 on Trabecular and Cortical Bone in Postmenopausal Osteoporosis: The OCEAN Study
Authors: Engelke Klaus , Nagase Shinichi , Fuerst Thomas , Small Maria , Kuwayama Tomohiro , Deacon Stephen , Eastell Richard , Genant Harry K 
Published: August 2013

ABSTRACT

ONO-5334 (Ono Pharmaceutical Co., Ltd., Osaka, Japan) inhibits cathepsin K and has been shown to increase areal bone mineral density (BMD) at the hip and spine in postmenopausal osteoporosis. Quantitative computed tomography (QCT) allows the study of the cortical and trabecular bone separately and provides structural information such as cortical thickness. We investigated the impact of 2 years of cathepsin K inhibition on these different bone compartments with ONO-5334. The clinical study was a randomized, double-blind, placebo, and active controlled parallel group study conducted in 13 centers in six European countries. The original study period of 12 months was extended by another 12 months. A total of 147 subjects (age 55–75 years) of the QCT substudy who participated in the extension period were included. Subjects had been randomized into one of five treatment arms: placebo; ONO-5334 50 mg twice per day (BID); ONO-5334 100 mg once daily (QD); ONO-5334 300 mg QD; or alendronate 70 mg once weekly (QW). QCT was obtained to evaluate bone structure at the lumbar spine and proximal femur. After 24 months ONO-5334 showed statistically significant increases versus placebo for integral, trabecular, and cortical BMD at the spine and the hip (for ONO-5334 300 mg QD, BMD increases were 10.5%, 7.1%, and 13.4% for integral, cortical, and trabecular BMD at the spine, respectively, and 6.2%, 3.4%, and 14.6% for integral, cortical, and trabecular total femur BMD, respectively). Changes in cortical and trabecular BMD in the spine and hip were similar for alendronate as for ONO-5334. Integral volume did not demonstrate statistically significant changes under ONO-5334 treatment, thus there was no evidence of periosteal apposition, neither at the spine nor at the femur. Cortical thickness changes were not statistically significant for ONO-5334 in the spine and hip, with exception of a 2.1% increase after month 24 in the intertrochanter for ONO-5334 300 mg QD. Over 2 years ONO-5334 showed a statistically significant and persistent increase of trabecular and integral BMD at the spine and the hip. Cortical BMD also progressively increased but at a lower rate. Changes in bone size and of periosteal apposition were not observed. © 2014 American Society for Bone and Mineral Research.