bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robust optimization of VMAT for lung cancer: Dosimetric implications of motion compensation techniques
Authors: Archibald‐Heeren Ben R. , Byrne Mikel V. , Hu Yunfei , Cai Meng , Wang Yang 
Published: August 2017

AbstractIn inverse planning of lung radiotherapy, techniques are required to ensure dose coverage of target disease in the presence of tumor motion as a result of respiration. A range of published techniques for mitigating motion effects were compared for dose stability across 5 breath cycles of ±2 cm. Techniques included planning target volume (PTV) expansions, internal target volumes with (OITV) and without tissue override (ITV), average dataset scans (ADS), and mini‐max robust optimization. Volumetric arc therapy plans were created on a thorax phantom and verified with chamber and film measurements. Dose stability was compared by DVH analysis in calculations across all geometries. The lung override technique resulted in a substantial lack of dose coverage (−10%) to the tumor in the presence of large motion. PTV, ITV and ADS techniques resulted in substantial (up to 25%) maximum dose increases where solid tissue travelled into low density optimized regions. The results highlight the need for care in optimization of highly heterogeneous where density variations may occur with motion. Robust optimization was shown to provide greater stability in both maximum (<3%) and minimum dose variations (<2%) over all other techniques.
Shoulder Dystocia Delivery by Emergency Medicine Residents: A High‐fidelity versus a Novel Low‐fidelity Simulation Model—A Pilot Study
Authors: Hart Danielle , Nelson Jessie , Moore Johanna , Gross Eric , Oni Adeleki , Miner James 
Published: August 2017

AbstractBackgroundShoulder dystocia (SD) requires emergent intervention to prevent maternal and fetal harm, and simulation models for training can be expensive. We developed a novel, cheap and easily transportable low‐fidelity simulation (LFS) model to compare to a commercially available high‐fidelity simulation (HFS) model.MethodsEmergency medicine residents were randomized to training on the HFS or novel LFS model. Subjects completed a pretest and a 1‐week and 6‐month posttest including a self‐assessment and a simulated SD delivery.ResultsTwenty‐seven of the 43 residents completed the study (63%). The number of individuals performing dangerous maneuvers at baseline was similar, 1 week after training was five in HFS and 11 in LFS (p = 0.08) groups and at 6 months was again similar between groups. Mean checklist scores for appropriate actions increased 1 week after training but returned to baseline by 6 months and were similar between groups. The rate of successful delivery, median time to successful delivery, and maximum force applied improved at 1 week and was sustained at 6 months in both groups.ConclusionWithin our limited study population, we did not find a large difference in the occurrence of dangerous actions during simulated SD delivery following HFS and LFS training. Our novel and easily transportable LFS trainer, assembled for less than US$10 each, may be a useful tool to train inexperienced providers on the steps of this procedure. However, this requires further study, as does whether HFS models with force monitoring capabilities may be helpful to train providers to minimize dangerous maneuvers such as the application of excessive force.
Pac13 is a Small, Monomeric Dehydratase that Mediates the Formation of the 3′‐Deoxy Nucleoside of Pacidamycins
Authors: Michailidou Freideriki , Chung Chun‐wa , Brown Murray J. B. , Bent Andrew F. , Naismith James H. , Leavens William J. , Lynn Sean M. , Sharma Sunil V. , Goss Rebecca J. M. 
Published: August 2017

AbstractThe uridyl peptide antibiotics (UPAs), of which pacidamycin is a member, have a clinically unexploited mode of action and an unusual assembly. Perhaps the most striking feature of these molecules is the biosynthetically unique 3′‐deoxyuridine that they share. This moiety is generated by an unusual, small and monomeric dehydratase, Pac13, which catalyses the dehydration of uridine‐5′‐aldehyde. Here we report the structural characterisation of Pac13 with a series of ligands, and gain insight into the enzyme's mechanism demonstrating that H42 is critical to the enzyme's activity and that the reaction is likely to proceed via an E1cB mechanism. The resemblance of the 3′‐deoxy pacidamycin moiety with the synthetic anti‐retrovirals, presents a potential opportunity for the utilisation of Pac13 in the biocatalytic generation of antiviral compounds.
An Insoluble Benzoquinone‐Based Organic Cathode for Use in Rechargeable Lithium‐Ion Batteries
Authors: Luo Zhiqiang , Liu Luojia , Zhao Qing , Li Fujun , Chen Jun 
Published: August 2017

AbstractApplication of organic electrode materials in rechargeable batteries has attracted great interest because such materials contain abundant carbon, hydrogen, and oxygen elements. However, organic electrodes are highly soluble in organic electrolytes. An organic electrode of 2,3,5,6‐tetraphthalimido‐1,4‐benzoquinone (TPB) is reported in which rigid groups coordinate to a molecular benzoquinone skeleton. The material is insoluble in aprotic electrolyte, and demonstrates a high capacity retention of 91.4 % (204 mA h g−1) over 100 cycles at 0.2 C. The extended π‐conjugation of the material contributes to enhancement of the electrochemical performance (155 mA h g−1 at 10 C). Moreover, density functional theory calculations suggest that favorable synergistic reactions between multiple carbonyl groups and lithium ions can enhance the initial lithium ion intercalation potential. The described approach may provide a novel entry to next‐generation organic electrode materials with relevance to lithium‐ion batteries.
Neuer Ansatz zur Bestimmung des Schubmoduls für einen Dämmstoff
Authors: Weiler Torsten , Kurz Wolfgang , Pahn Matthias 
Published: August 2017

AbstractMaßgebend für die wirtschaftliche Bemessung eines Stahlbetonsandwichelementes ist die realitätsnahe Ermittlung der Verformungen und der inneren Schnittgrößenverteilung. Entscheidend für diese Ermittlung sind unter anderem genaue Kenntnisse bezüglich der Materialeigenschaften des Dämmstoffes. Deshalb wurde das Materialverhalten für den eingesetzten Dämmstoff unter einer Druck‐ und Schubbeanspruchung anhand von umfangreichen experimentellen Untersuchungen analysiert. Es hat sich herausgestellt, dass die Bestimmung der Scherfestigkeit sowie des Schubmoduls in Anlehnung an die geltende Norm DIN EN 12090 nicht eindeutig und damit unzufrieden stellend ist. Über‐ oder Unterschätzungen des Schubmoduls führen bei der Ermittlung der inneren Schnittgrößenverteilung und der Verformungen eines Sandwichelementes zu ungenauen und gegebenenfalls zu falschen Ergebnissen. Deshalb wurde ein neuer Ansatz zur Ermittlung des Schubmoduls für einen Dämmstoff entwickelt. Das neue Vorgehen zur Ermittlung des Schubmoduls liefert gleichzeitig hilfreiche Werte in Form von Spannungs‐ und Verformungsgrenzen, die die Bemessung von Sandwichelementen optimieren können.
Effect of erbium ion concentration on structural and luminescence properties of lead borosilicate glasses for fiber amplifiers
Authors: Babu Midde Reddi , Madhusudhana Rao N. , Mohan Babu A. 
Published: August 2017

AbstractThis investigation reports, the effect of the concentration of erbium and lead ions on the physical, structural and optical properties of lead borosilicate glasses. These glasses were synthesized by the melt quench method. In the synthesis, the concentration of the erbium (Er3+) ion was varied in the order of 0.0, 0.1, 0.5, 1.0 and 2.0 mol% and lead (Pb2+) ion was varied in the order of 30, 29.9, 29.5, 29 and 28 mol%. The glasses were analyzed using X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR) and UV–vis–NIR spectroscopy. From XRD, the amorphous nature of lead borosilicate glasses was confirmed. The functional groups which were present in the glasses have been identified by analyzing the FT‐IR spectrum. From the absorption spectra, the oscillator strengths as well as the Judd–Ofelt (JO) intensity parameters were determined and compared with other hosts. The JO intensity parameters were further used to calculate certain radiative properties for the excited luminescent levels of Er3+ ion. From emission spectra, full width at half maxima (FWHM), stimulated emission cross‐sections (σe) and certain lasing parameters were evaluated and compared with reference host glasses. The lifetimes of 4I13/2 excited level of Er3+ ion have also been recorded and analyzed. The calculated and experimental lifetimes were compared in terms of quantum efficiencies. From the photoluminescence analysis, the erbium doped lead borosilicate glasses well suited for optical fiber amplifiers are discussed.
Differentially activated Src kinase in chemo‐naïve human primary osteosarcoma cells and effects of a Src kinase inhibitor
Authors: Laschi Marcella , Bernardini Giulia , Geminiani Michela , Manetti Fabrizio , Mori Mattia , Spreafico Adriano , Campanacci Domenico , Capanna Rodolfo , Schenone Silvia , Botta Maurizio , Santucci Annalisa 
Published: August 2017

AbstractThe therapeutic treatment of osteosarcoma (OS), a rare malignant teenage cancer of the skeletal system, still represents a great challenge as patient survival after conventional protocol chemotherapy treatment has not improved in the last four decades leaving poor patient prognoses. Therefore, many efforts have been done to find increasingly reliable OS cell models and to identify “druggable” targets in OS, in order to identify novel effective therapeutic approaches and treatment strategies. In this contest, the more successful use of patient‐derived cell cultures in respect to human commercial lines and findings of Src kinase deregulation in cancer, prompted us to study for the first time the activation state of Src and the potential activity of our Src inhibitor SI‐83 in a number of chemo‐naïve patient‐derived primary OS cells. We here demonstrate that Src is hyperactivated in OS cells in respect to the nonmalignant counterpart and that SI‐83 is able to strongly decrease cell viability, proliferation, Src416 phosphorylation, and cell migration. © 2017 BioFactors, 43(6):801–811, 2017
High glucose and free fatty acids induce endothelial progenitor cell senescence via PGC‐1α/SIRT1 signaling pathway
Authors: Song Xiaoxiao , Yang Boyun , Qiu Fuyu , Jia Minyue , Fu Guosheng 
Published: August 2017

AbstractThe objective of the research was to investigate the function of endothelial progenitor cells (EPCs) in the conditions of high glucose and lipids, which has been widely used to mimic the metabolic disorder that occurs in type 2 diabetic mellitus, and further to verify the role of PGC‐1α and SIRT1, cellular energy metabolism regulators, in the process of senescence of EPCs with these combined stimuli. Circulating EPCs were incubated in absence or presence of high glucose (25 mM), FFA (200 µM) or both. EPCs senescence was assessed by β‐galactosidase staining, EPCs telomerase activity was measured by telomeric repeat ampli­fication protocol assay, in vitro angiogenesis assay and MTT assays were performed to assess angiogenesis and proliferation ability of EPCs. The results showed that combined stimuli inhibited EPCs reendothelialization ability in vitro, accelerated EPCs senescence and decreased the telomerase activity. Meanwhile, with combined stimuli, the expression of PGC‐1α increased whereas SIRT1 expression decreased in EPCs accompanied by activation of P53/P21 signaling pathway. Conversely, transfection of EPCs with PGC‐1α‐siRNA rescued EPCs premature senescence and up‐regulated SIRT1 and decreased P53/P21 expression, correlating closely with the down‐regulation of PGC‐1α itself. In addition, the combined stimuli induced up‐regulation of PGC‐1α expression was partly mediated by ROS and P38 signaling pathway. Overall, the data presented here identify PGC‐1α as a potent negative regulator of EPCs’ senescence under combined stimuli, which is partly mediated by SIRT1/P53/P21 signaling pathway.
Origin and Abatement of Heterogeneity at the Support Granule Scale of Silver on Silica Catalysts
Authors: Plessers Eva , van den Reijen Jeroen E. , de Jongh Petra E. , de Jong Krijn P. , Roeffaers Maarten B. J. 
Published: August 2017

AbstractIncipient wetness impregnation is used commonly to form supported metal nanoparticle catalysts. Recently, it has been revealed that this approach may induce severe heterogeneity between catalyst granules of the same batch. At least a 10‐fold variation in metal loading was observed, which affect the catalytic performance of individual catalyst granules severely. However, the origin of this heterogeneity is still unclear. Here we show that every elementary step in the preparation procedure of a Ag on silica catalyst has an effect on the resulting interparticle heterogeneity, but the influence of the drying step is the most important. This is because drying by capillary force results in a heterogeneous sample. Specifically, the position of a granule in the stagnant drying bed influences the resulting color and, thus, Ag loading significantly. This is further demonstrated by varying the drying conditions: freeze‐drying and fluidized‐bed drying led to a more homogeneous Ag loading. An investigation of the fluidized‐bed‐dried sample by using optical microscopy revealed a large fraction of transparent granules (94 %), which indicates that almost all the Ag nanoparticles in this sample are confined within the 6 nm pores. The optimized supported Ag on silica catalyst shows a good catalytic performance. This adaptation of the drying step can be implemented easily on a laboratory scale, is scalable, and does not require the use of expensive solvents or metal precursors.
Improvement in the Energy Density of Na3V2(PO4)3 by Mg Substitution
Authors: Inoishi Atsushi , Yoshioka Yuto , Zhao Liwei , Kitajou Ayuko , Okada Shigeto 
Published: August 2017

AbstractNa3V2(PO4)3, with a NASICON‐type structure, is a promising cathode material for use in sodium‐ion batteries based on a two‐electron reaction and operating at 3.4 V. Herein, we report the synthesis of Na3+xV2‐xMgx(PO4)3 (x=0.1 to 0.7) for use as a cathode material in sodium‐ion batteries. In this work, Na3.2V1.8Mg0.2(PO4)3 was found to exhibit a larger reversible capacity than the theoretical capacity of undoped Na3V2(PO4)3, as a result of the larger number of Na+ in the initial composition, as well as access to the V4+/V5+ redox couple. In contrast, although Mg‐rich samples such as Na3.5V1.5Mg0.5(PO4)3 showed a relatively clear plateau for the V4+/V5+ redox couple, the total discharge capacities were lower than that of the undoped Na3V2(PO4)3 because of the irreversibility in the V4+/V5+ redox region. ICP data clearly indicated that Mg2+ are stable within the NASICON structure during redox cycling and that Na+ is the charge carriers in this cathode.
Individualization and Stabilization of Zinc Oxide Nanorods by Covalent Functionalization with Positively Charged Catechol Derivatives
Authors: Burger Alexandra , Srikantharajah Rubitha , Peukert Wolfgang , Hirsch Andreas 
Published: August 2017

AbstractWe present the formation of individualized and stabilized zinc oxide (ZnO) nanorods by functionalization with positively charged catechol derivatives by means of ligand exchange reactions. The electrosteric stabilization of ZnO nanorods was studied using two catechol derivatives, introducing either three (1) or six (2) pH independent positive charges per molecule and sterically demanding groups onto the surface. ZnO nanorods providing initially acetate (Ac) or 2‐[2‐(2‐methoxyethoxy)‐ethoxy]acetic acid (TODA) ligands on their surface were used. The ligand exchange was performed by using mono and mixed functionalization approaches, utilizing either exclusively the positively charged catechols or mixtures of the latter with small commercially available catechol derivatives, namely 4‐methylcatechol (Me‐cat), 4‐tert‐butylcatechol (tBu‐cat), and dopamine hydrochloride (Dop). Using a combination of various analytical methods such as zeta potential, dynamic light scattering (DLS), UV/Vis, and scanning electron microscopy (SEM) measurements we found that the initial surfactants on the nanorods surface, the number of positive charges per molecule, the steric demand, and the added amount of the catechol derivative strongly influence the colloidal behavior of the nanorods. Stable suspensions containing individualized ZnO nanorods were successfully formed upon functionalization of ZnO‐TODA nanorods with 30 monolayers (MLs) of the higher charged catechol (2), as well as using mixtures of 20/10 and 18/10 MLs of 2/Dop.
An Efficient Route to Highly Substituted Indoles via Tetrahydroindol‐4(5H)‐one Intermediates Produced by Ring‐Opening Cyclization of Spirocyclopropanes with Amines
Authors: Nambu Hisanori , Hirota Wataru , Fukumoto Masahiro , Tamura Takafumi , Yakura Takayuki 
Published: August 2017

AbstractAn efficient route to highly substituted indoles was developed. It included regioselective functionalization of tetrahydroindol‐4(5H)‐ones, prepared by ring‐opening cyclization of cyclohexane‐1,3‐dione‐2‐spirocyclopropanes with primary amines, and subsequent oxidation. The 6‐substituted indoles were synthesized from a readily available 5‐substituted cyclohexane‐1,3‐dione‐2‐spirocyclopropane. The synthesis of 5‐ and 7‐substituted indoles was achieved by regioselective electrophilic alkylation of tetrahydroindol‐4(5H)‐one, followed by oxidation. The 4‐substituted indoles were synthesized by nucleophilic alkylation of the corresponding pyrrole derivative, which was prepared by partial oxidation of tetrahydroindol‐4(5H)‐one, and sequential oxidation. The synthesis of 4‐substituted indoles was also accomplished by palladium‐catalyzed coupling of 4‐hydroxyindole‐derived triflates. Furthermore, the synthesis of 4,5,6,7‐tetrasubstituted indoles was achieved by using these regioselective alkylations.
Recent Advances in GLP‐1 Receptor Agonists for Use in Diabetes Mellitus
Authors: McBrayer Dominic N. , Tal‐Gan Yftah 
Published: August 2017

ABSTRACT

Preclinical Research

Mimetics of Glucagon‐like peptide 1 (GLP‐1) represent a useful alternative or complementary treatment choice to insulin in the treatment of diabetes mellitus. The lack of hypoglycemia as a side effect when GLP‐1 receptor agonists are used along with the tendency of these therapeutic agents to prevent or even reduce weight gain makes them valuable targets in therapy development. However, native GLP‐1 and many of its early analogues have very short half‐lives, requiring repeated treatment to maintain therapeutic levels. As all current treatments are injected subcutaneously, a large focus has been made on trying to extend the half‐lives of GLP‐1 analogues while retaining bioactivity. Most success in this regard has been achieved with the use of peptide‐protein fusions, which are not as well suited for oral administration. However, recent work focused on the development of non‐fusion peptides with increased half‐lives that may be more appropriate for oral administration. This minireview discusses the structural characteristics of past and present analogues as well as the recent work conducted toward developing novel GLP‐1 receptor agonists. Drug Dev Res 78 : 292–299, 2017. © 2017 Wiley Periodicals, Inc.
Mixture effects of copper, cadmium, and zinc on mortality and behavior of Caenorhabditis elegans
Authors: Moyson Sofie , Vissenberg Kris , Fransen Erik , Blust Ronny , Husson Steven J. 
Published: August 2017

Abstract

The toxicity effects of zinc (Zn), copper (Cu), and cadmium (Cd), both as single metals and in combination, were examined in the nematode Caenorhabditis elegans. Metal effects on lethality were analyzed in a time-dependent manner using different concentrations in K-medium. To investigate the effects on locomotion and chemosensation, lethal concentration at 20% (LC20) values were used. The results showed that Cu toxicity was higher compared with Cd and Zn, resulting in higher mortality rates and a more reduced locomotion. Lethality increased over time for all metals. When Cd was added to Cu, and vice versa, significant increases in toxicity were noted. Different interaction effects were observed for the mixtures ZnCd, ZnCu, CuCd, and ZnCuCd. Zinc seemed to have a neutral toxic effect on Cd, while in combination with Cu, a similar additive effect was seen as for the CuCd combination. Binary and tertiary metal mixtures caused a strong decrease in locomotion, except for the ZnCd combination, where Zn seemed to have a neutral effect. After LC2024 h exposure, reduced crawling speed (except for Zn) and reduced thrashing behavior (except for Zn and the ZnCd mixture) were observed. Almost no significant effects were observed on chemosensation. Because the same trend of mixture effects was noted in locomotion and in lethality tests, locomotion can probably be considered a sensitive endpoint for metal toxicities. Environ Toxicol Chem 2018;37:145–159. © 2017 SETAC
Predicting US bank failures: A comparison of logit and data mining models
Authors: Jing Zhongbo , Fang Yi 
Published: August 2017

AbstractPredicting bank failures is important as it enables bank regulators to take timely actions to prevent bank failures or reduce the cost of rescuing banks. This paper compares the logit model and data mining models in the prediction of bank failures in the USA between 2002 and 2010 using levels and rates of change of 16 financial ratios based on a cross‐section sample. The models are estimated for the in‐sample period 2002–2009, while data for the year 2010 are used for out‐of‐sample tests. The results suggest that the logit model predicts bank failures in‐sample less precisely than data mining models, but produces fewer missed failures and false alarms out‐of‐sample.
Control System Design of Power Tracking for PEM Fuel Cell Automotive Application
Authors: Chen F. X. , Yu Y. , Chen J. X. 
Published: August 2017

AbstractOwing to load variations, the power tracking of fuel cells in automotive applications is emphasized. We address the control strategies to meet varying power demands while optimizing system efficiency. Based on the control‐oriented proton exchange membrane fuel cell model, the relative gain array is analyzed to determine variable parings in control design. As the dynamics of two control variables are different, a cascade control architecture is adopted. A feedforward‐feedback composite control is used to achieve fast response and eliminate the stable error. To avoid oxygen starvation at power transients, an oxygen excess ratio constrained strategy is proposed to limit the load current if there is lack of reaction oxygen. A mixed‐sensitivity synthesis is applied to suppress parameter perturbation and improve system robustness. To further suppress the fluctuations of the oxygen excess ratio and achieve the maximum system efficiency, an oxygen excess ratio invariant strategy is developed, which coordinates load current with airflow. A comparative study is conducted, with two scenarios of power tracking and fuel cell degradation. The results show that the mixed‐sensitivity strategy has a fast response in power tracking and effective perturbation suppression performance, while the oxygen excess ratio invariant strategy maximizes the system efficiency.
A sequential Monte Carlo approach to inference in multiple‐equation Markov‐switching models
Authors: Bognanni Mark , Herbst Edward 
Published: August 2017

SummaryVector autoregressions with Markov‐switching parameters (MS‐VARs) offer substantial gains in data fit over VARs with constant parameters. However, Bayesian inference for MS‐VARs has remained challenging, impeding their uptake for empirical applications. We show that sequential Monte Carlo (SMC) estimators can accurately estimate MS‐VAR posteriors. Relative to multi‐step, model‐specific MCMC routines, SMC has the advantages of generality, parallelizability, and freedom from reliance on particular analytical relationships between prior and likelihood. We use SMC's flexibility to demonstrate that model selection among MS‐VARs can be highly sensitive to the choice of prior.