bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Boron Doping On Graphene Oxide for Ammonia Adsorption
Authors: Yang Heena , Züttel Andreas , Kim Shindong , Ko Youngdon , Kim Whajung 
Published: August 2017

AbstractBoron doped graphene oxide (B‐GO) is a highly effective adsorbent for ammonia due to the high density of strong Lewis acid sites arising from the boron. GO was doped by various amounts of boron described as xB‐GO (x=1.0, 3.0, and 5.0). B‐GO was successfully synthesized and the boron doping was confirmed by X‐ray diffraction, Fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy. The adsorption characteristics of B‐GO were investigated by adsorption isotherm and thermal desorption spectroscopy. The adsorption isotherm shows an increase of ammonia adsorption with increasing concentration of boron such as 12.03 mol kg−1, 16.30 mol kg−1 and 15.58 mol kg−1. It is confirmed that the amount of ammonia adsorbed on the boron sites is limited to a certain amount due to the reduction of Lewis acid sites by B−O bonds. Boron doped into GO significantly enhances the adsorption capacity for ammonia.
Pharmacokinetics and Bioequivalence of Branded and Generic Formulations of Dofetilide 0.5‐mg Capsules After Single‐Dose Administration in Healthy Subjects
Authors: VanderLugt James T. , Bon Charles , Knuth Dean , Schreiber Rhonda , Ruff Michael D. 
Published: August 2017

AbstractClass III antiarrhythmics are preferred therapy for managing atrial fibrillation/flutter. Dofetilide 0.5‐mg capsules were US Food and Drug Administration (FDA) approved in 1999 to treat atrial fibrillation/flutter. Bioequivalence of generic dofetilide is important for treating arrhythmias because drug concentrations must be consistent to maintain normal sinus rhythm. Generic dofetilide 0.5‐mg capsule pharmacokinetics were compared with branded product in 2 open‐label, 2‐way crossover, single‐dose studies — 1 study each in fasted and fed healthy subjects. Blood samples were collected before and up to 48 hours after dosing. Safety was assessed by tabulating adverse events and vital signs. Seventy‐three subjects were enrolled; 59 completed the studies. In fasted subjects, the 90% confidence intervals (CIs) for generic dofetilide 0.5 mg versus the reference formulation were 0.996–1.026 for the area under the plasma concentration–time curve from 0 to infinity (AUC) and 0.974–1.066 for the maximum observed concentration (Cmax). In fed subjects, the 90%CIs for AUC and Cmax were 0.988–1.015 and 0.928–0.992, respectively. All ratios were within the FDA‐established bioequivalence range. Twenty‐six subjects experienced 37 adverse events (generic, 15; reference, 22); all but 1 were mild or moderate in severity. Generic dofetilide 0.5‐mg capsules can be considered bioequivalent to the reference product.
Relative Bioavailability of Fixed‐Dose Combinations of Tamsulosin and Dutasteride: Results From 2 Randomized Trials in Healthy Male Volunteers
Authors: Burns Olivia , Zhu John , Manyak Michael J , Ravindranath Ramiya , Koosha Fariba , Haque Nazneen , Chung Sally 
Published: August 2017

AbstractThe relative bioavailabilities of dutasteride/tamsulosin hydrochloride 0.5 mg/0.2 mg fixed‐dose combination (FDC) capsules compared with coadministered reference products (1 dutasteride 0.5‐mg capsule [Avodart®] + 1 tamsulosin hydrochloride 0.2‐mg orally disintegrating tablet [Harnal D®]) were investigated in 2 clinical trials under fasted and fed conditions (ClinicalTrials.gov NCT02184585 and NCT02509104). Both trials were open‐label, randomized, single‐dose, crossover studies in healthy male adults aged 18‐65 years. Trial 1 evaluated 2 formulations (FDC1 and FDC2), and trial 2 evaluated a third formulation (FDC3). The primary end points were dutasteride area under the concentration‐time curve from time 0 to t (AUC(0‐t)) and peak plasma concentration (Cmax) and tamsulosin AUC(0‐∞), AUC(0‐t), and Cmax. The formulations were considered to be bioequivalent if the 90%CIs for the geometric mean ratios for each end point were within the range of 0.80‐1.25. For FDC1 in trial 1, bioequivalence criteria were not met for dutasteride Cmax or AUC in the fasted state or for tamsulosin Cmax in the fasted or fed states. For FDC2 in trial 1, all bioequivalence criteria were met except for tamsulosin Cmax in the fasted state. For FDC3 in trial 2, bioequivalence criteria were met for all dutasteride and tamsulosin end points in both the fed and fasted states. Safety profiles were similar for all FDC formulations and combination treatments.
Quantitative Dextran Trafficking to the Coxiella burnetii Parasitophorous Vacuole
Authors: Winfree Seth , Gilk Stacey D. 
Published: August 2017

AbstractThe gram‐negative bacterium Coxiella burnetii causes human Q fever, a disease characterized by a debilitating flu‐like illness in acute cases and endocarditis in chronic patients. An obligate intracellular pathogen, Coxiella burnetii survives within a large, lysosome‐like vacuole inside the host cell. A unique feature of the Coxiella parasitophorous vacuole (PV) is high levels of fusion with the host endocytic pathway, with PV‐endosome fusion critical for Coxiella survival within the host cell. This unit describes quantitating PV‐endosome fusion by measuring delivery of the fluid phase endosome marker dextran to the PV using live cell imaging. To study the effect of host cell proteins involved in PV‐endosome fusion, details are provided for using siRNA knockdown host cells. This method is a powerful tool for understanding mechanisms underlying Coxiella’s ability to manipulate host cell trafficking pathways. © 2017 by John Wiley & Sons, Inc.
Epigenetic Analysis of SV40 Minichromosomes
Authors: Balakrishnan Lata , Milavetz Barry 
Published: August 2017

AbstractSimian virus 40 (SV40) is one of the best‐characterized members of the polyomavirus family of small DNA tumor viruses. It has a small genome of 5243 bp and utilizes cellular proteins for its molecular biology, with the exception of the T‐antigen protein, which is coded by the virus and is involved in regulating transcription and directing replication. Importantly, SV40 exists as chromatin in both the virus particle and intracellular minichromosomes. These facts, combined with high yields of virus and minichromosomes following infection and ease of manipulation, have made SV40 an extremely useful model to study all aspects of eukaryotic molecular biology. This unit describes procedures for working with SV40 and preparing SV40 chromatin from infected cells and virus particles, as well as procedures for using SV40 chromatin to study epigenetic regulation. © 2017 by John Wiley & Sons, Inc.
Misbehavior analysis of IEEE 802.11 MAC layer in mobile ad hoc network using stochastic reward nets
Authors: Yadollahzadeh Tabari Meisam , Pouyan Ali A. 
Published: August 2017

SummaryIn this paper, we present a Petri net model for performance evaluation of IEEE 802.11 distributed coordination function as a popular media access control layer protocol in mobile ad hoc network. The goal of this evaluation is to examine this protocol under the existing of misbehavior nodes that selfishly try to grasp common channel in a neighbor area. The presented model consists of 2 separate models based on stochastic reward net (SRN), as a variation of stochastic Petri net. The first model, which is called one node operation model, is supposed for presenting all distributed coordination function operations in a single node such as collision avoidance, request to send/clear to send (RTS/CTS) handshake, and backoff mechanism. The next SRN model, all node operation model, is used for modeling nodes competition for occupying channel in a neighbor area. The models could be adjusted to a dynamic network with any number of nodes, dimension scale, and nodes' speed. For evaluation purpose, 4 distinct attack types implemented by modifying associated transitions in SRN models. The proposed SRN model has been quantified by deriving 2 performances metrics as Throughput and Delay. Both metrics are also compared to the value obtained from NS‐2 in terms of different number of nodes and 3 packet generation rates. Three additional metrics measuring the channel usage are also quantified in terms of different attack strategies using only presented SRN model.
Small Scaffolds, Big Potential: Developing Miniature Proteins as Therapeutic Agents
Authors: Holub Justin M. 
Published: August 2017

ABSTRACT

Preclinical Research

Miniature proteins are a class of oligopeptide characterized by their short sequence lengths and ability to adopt well‐folded, three‐dimensional structures. Because of their biomimetic nature and synthetic tractability, miniature proteins have been used to study a range of biochemical processes including fast protein folding, signal transduction, catalysis and molecular transport. Recently, miniature proteins have been gaining traction as potential therapeutic agents because their small size and ability to fold into defined tertiary structures facilitates their development as protein‐based drugs. This research overview discusses emerging developments involving the use of miniature proteins as scaffolds to design novel therapeutics for the treatment and study of human disease. Specifically, this review will explore strategies to: (i) stabilize miniature protein tertiary structure; (ii) optimize biomolecular recognition by grafting functional epitopes onto miniature protein scaffolds; and (iii) enhance cytosolic delivery of miniature proteins through the use of cationic motifs that facilitate endosomal escape. These objectives are discussed not only to address challenges in developing effective miniature protein‐based drugs, but also to highlight the tremendous potential miniature proteins hold for combating and understanding human disease. Drug Dev Res 78 : 268–282, 2017. © 2017 Wiley Periodicals, Inc.
Development and field validation of a regional, management‐scale habitat model: A koala Phascolarctos cinereus case study
Authors: Law Bradley , Caccamo Gabriele , Roe Paul , Truskinger Anthony , Brassil Traecey , Gonsalves Leroy , McConville Anna , Stanton Matthew 
Published: August 2017

AbstractSpecies distribution models have great potential to efficiently guide management for threatened species, especially for those that are rare or cryptic. We used MaxEnt to develop a regional‐scale model for the koala Phascolarctos cinereus at a resolution (250 m) that could be used to guide management. To ensure the model was fit for purpose, we placed emphasis on validating the model using independently‐collected field data. We reduced substantial spatial clustering of records in coastal urban areas using a 2‐km spatial filter and by modeling separately two subregions separated by the 500‐m elevational contour. A bias file was prepared that accounted for variable survey effort. Frequency of wildfire, soil type, floristics and elevation had the highest relative contribution to the model, while a number of other variables made minor contributions. The model was effective in discriminating different habitat suitability classes when compared with koala records not used in modeling. We validated the MaxEnt model at 65 ground‐truth sites using independent data on koala occupancy (acoustic sampling) and habitat quality (browse tree availability). Koala bellows (n = 276) were analyzed in an occupancy modeling framework, while site habitat quality was indexed based on browse trees. Field validation demonstrated a linear increase in koala occupancy with higher modeled habitat suitability at ground‐truth sites. Similarly, a site habitat quality index at ground‐truth sites was correlated positively with modeled habitat suitability. The MaxEnt model provided a better fit to estimated koala occupancy than the site‐based habitat quality index, probably because many variables were considered simultaneously by the model rather than just browse species. The positive relationship of the model with both site occupancy and habitat quality indicates that the model is fit for application at relevant management scales. Field‐validated models of similar resolution would assist in guiding management of conservation‐dependent species.
Simultaneous Determination of Peroxide Hydrogen and Ascorbic Acid by Capillary Electrophoresis with Platinum Nanoparticles Modified Micro‐disk Electrode
Authors: Wang J. , Zhou M. , Dong R. , Cong X. , Zhang R. , Wang X. 
Published: August 2017

AbstractIn this study, the first application of a capillary zone electrophoresis‐electrochemical detection (CE‐ECD) method for concurrent determination of hydrogen peroxide (H2O2) and ascorbic acid (AA), was developed using the Pt nanoparticles (PtNPs) modified Pt micro‐disk electrode (PtME). The electrocatalytic activity of the modified electrode for H2O2 and AA was characterized by cyclic voltammetry. Under optimized experimental conditions, highly linear calibration plots were observed for both H2O2 and AA, with concentration linear ranges of 0.8 μM to 0.8 mM and 1.0 μM to 0.8 mM. Detection limits of 0.2 μM H2O2 and 0.5 μM AA were determined on the basis of the signal‐to‐noise characteristics (S/N=3) of an electropherogram. Compared with the unmodified PtME, the sensitivity was promoted in that PtNPs/PtME provided an increased effective electrode surface and high catalytic activity toward H2O2 and AA. Using this method, the added H2O2 and AA in Mizone, a kind of functional drink, were detected, and the concentration of AA was found to be 2.33 mM (n=3). The recovery rates were 95.3 % for H2O2 and 98.7 % for AA. The novel approach provided a wide linear range, low detection limit, good reproducibility and stability. It will provide a new insight into the balance of reactive oxygen species and antioxidant in biological systems.
Effects of chronic cadmium exposure on metamorphosis, skeletal development, and thyroid endocrine disruption in Chinese toad Bufo gargarizans tadpoles
Authors: Sun Nailiang , Wang Hongyuan , Ju Zongqi , Zhao Hongfeng 
Published: August 2017

Abstract

The present study examined the effects of chronic cadmium (Cd) exposure on metamorphosis, body size, thyroid gland, and skeletal development of Chinese toad (Bufo gargarizans) tadpoles. Tadpoles were exposed to Cd concentrations at 0, 5, 10, 50, 100, and 500 μg/L from Gosner stages 26 to 46 of completion of metamorphosis. Our results showed that 100 and 500 μg/L of Cd concentrations increased mortality and decelerated metamorphosis rate. In addition, significant body size reduction at Gosner stage 42 was observed at 100 and 500 μg/L of Cd treatments (p &lt; 0.01). Average body length and hind-limb length were significantly decreased in the 500 μg/L of Cd group (p &lt; 0.05) but body mass was not significantly different at Gosner stage 46. Moreover, bone formation was delayed in high Cd concentration treatments (50, 100, and 500 μg/L) at both Gosner stage 42 and 46. Histopathological changes of the thyroid gland showed that follicular cell hyperplasia and malformation were induced by high Cd concentrations (50, 100, and 500 μg/L). Furthermore, real-time polymerase chain reaction analysis suggested that the larvae exposed to high-dose Cd exhibited a significant decrease in deiodinase (Dio2) and thyroid hormone receptor (TRβ) mRNA levels at Gosner stage 42 and 46. Our investigation indicated that high-dose Cd caused metamorphic deceleration, body size reduction, and delayed skeletal development through disrupting the thyroid system in B. gargarizans larvae. Environ Toxicol Chem 2018;37:213–223. © 2017 SETAC
Combining a root exclusion technique with continuous chamber and porous tube measurements for a pin‐point separation of ecosystem respiration in croplands
Authors: Hoffmann Mathias , Wirth Stephan J. , Beßler Holger , Engels Christof , Jochheim Hubert , Sommer Michael , Augustin Jürgen 
Published: August 2017

AbstractTo better assess ecosystem C budgets of croplands and understand their potential response to climate and management changes, detailed information on the mechanisms and environmental controls driving the individual C flux components are needed. This accounts in particular for the ecosystem respiration (Reco) and its components, the autotrophic (Ra) and heterotrophic respiration (Rh) which vary tremendously in time and space. This study presents a method to separate Reco into Ra [as the sum of Ra (shoot) and Ra (root)] and Rh in order to detect temporal and small‐scale spatial dynamics within their relative contribution to overall Reco. Thus, predominant environmental drivers and underlying mechanisms can be revealed. Reco was derived during nighttime by automatic chamber CO2 flux measurements on plant covered plots. Rh was derived from CO2 efflux measurements, which were performed in parallel to Reco measurements on a fallow plot using CO2 sampling tubes in 10 cm soil depth. Ra (root) was calculated as the difference between sampling tube CO2 efflux measurements on a plant covered plot and Rh. Ra (shoot) was calculated as Reco – Ra (root) – Rh. Measurements were carried out for winter wheat (Triticum aestivum L.) during the crop season 2015 at an experimental plot located in the hummocky ground moraine landscape of NE Germany. Reco varied seasonally from < 1 to 9.5 g C m−2 d−1, and was higher in adult (a) and reproductive (r) than juvenile (j) stands (g C m−2 d−1: j = 1.2, a = 4.6, r = 5.3). Observed Ra and Rh were in general smaller compared to the independently measured Reco, contributing in average 58% and 42% to Reco. However, both varied strongly regarding their environmental drivers and particular contribution throughout the study period, following the seasonal development of soil temperature and moisture (Rh) as well as crop development (Ra). Thus, our results consistently revealed temporal dynamics regarding the relative contribution of Ra (root) and Ra (shoot) to Ra, as well as of Ra and Rh to Reco. Based on the observed results, implications for partitioning of Reco in croplands are given.
Combining evidence from multiple electronic health care databases: performances of one‐stage and two‐stage meta‐analysis in matched case‐control studies
Authors: La Gamba Fabiola , Corrao Giovanni , Romio Silvana , Sturkenboom Miriam , Trifirò Gianluca , Schink Tania , de Ridder Maria 
Published: August 2017

AbstractPurposeClustering of patients in databases is usually ignored in one‐stage meta‐analysis of multi‐database studies using matched case‐control data. The aim of this study was to compare bias and efficiency of such a one‐stage meta‐analysis with a two‐stage meta‐analysis.MethodsFirst, we compared the approaches by generating matched case‐control data under 5 simulated scenarios, built by varying: (1) the exposure‐outcome association; (2) its variability among databases; (3) the confounding strength of one covariate on this association; (4) its variability; and (5) the (heterogeneous) confounding strength of two covariates. Second, we made the same comparison using empirical data from the ARITMO project, a multiple database study investigating the risk of ventricular arrhythmia following the use of medications with arrhythmogenic potential. In our study, we specifically investigated the effect of current use of promethazine.ResultsBias increased for one‐stage meta‐analysis with increasing (1) between‐database variance of exposure effect and (2) heterogeneous confounding generated by two covariates. The efficiency of one‐stage meta‐analysis was slightly lower than that of two‐stage meta‐analysis for the majority of investigated scenarios. Based on ARITMO data, there were no evident differences between one‐stage (OR = 1.50, CI = [1.08; 2.08]) and two‐stage (OR = 1.55, CI = [1.12; 2.16]) approaches.ConclusionsWhen the effect of interest is heterogeneous, a one‐stage meta‐analysis ignoring clustering gives biased estimates. Two‐stage meta‐analysis generates estimates at least as accurate and precise as one‐stage meta‐analysis. However, in a study using small databases and rare exposures and/or outcomes, a correct one‐stage meta‐analysis becomes essential.
Solution properties, unperturbed dimensions, and chain flexibility of poly(1‐adamantyl acrylate)
Authors: Lu Wei , Yin Panchao , Osa Masashi , Wang Weiyu , Kang Nam‐Goo , Hong Kunlun , Mays Jimmy W. 
Published: August 2017

ABSTRACTPoly(1‐adamantyl acrylate) (PAdA) exhibits much higher glass transition and degradation temperatures than other polyacrylates. However, the quantitative evaluation of the stiffness of this polymer chain has not been reported previously. In this study, the dilute solution properties and conformational characteristics of PAdA were evaluated using viscometry and scattering techniques. The unperturbed dimensions of this polymer were evaluated using the Burchard–Stockmayer–Fixman extrapolation and the touched‐bead wormlike chain model. The PAdA chain has a comparable persistence length, diameter per bead and characteristic ratio to poly(methyl methacrylate) and polystyrene. All these results indicate that PAdA is less flexible than common polyacrylates. In addition, the second virial coefficients (A2) of PAdA in different solvents obtained by static light scattering were compared. Among the solvents investigated, tetrahydrofuran is a moderate solvent. Radius of gyration of a polymer sample in the various solvents ranged from 16.8 to 30.3 nm. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 1526–1531
The molecular mechanism behind resistance of the kinase FLT3 to the inhibitor quizartinib
Authors: Friedman Ran 
Published: August 2017

AbstractFms‐like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase that is a drug target for leukemias. Several potent inhibitors of FLT3 exist, and bind to the inactive form of the enzyme. Unfortunately, resistance due to mutations in the kinase domain of FLT3 limits the therapeutic effects of these inhibitors. As in many other cases, it is not straightforward to explain why certain mutations lead to drug resistance. Extensive fully atomistic molecular dynamics (MD) simulations of FLT3 were carried out with an inhibited form (FLT‐quizartinib complex), a free (apo) form, and an active conformation. In all cases, both the wild type (wt) proteins and two resistant mutants (D835F and Y842H) were studied. Analysis of the simulations revealed that impairment of protein‐drug interactions cannot explain the resistance mutations in question. Rather, it appears that the active state of the mutant forms is perturbed by the mutations. It is therefore likely that perturbation of deactivation of the protein (which is necessary for drug binding) is responsible for the reduced affinity of the drug to the mutants. Importantly, this study suggests that it is possible to explain the source of resistance by mutations in FLT3 by an analysis of unbiased MD simulations.