bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabricating PLGA microparticles with high loads of the small molecule antioxidant N‐acetylcysteine that rescue oligodendrocyte progenitor cells from oxidative stress
Authors: Murphy Nicholas P. , Lampe Kyle J. 
Published: September 2017

AbstractReactive oxygen species (ROS), encompassing all oxygen radical or non‐radical oxidizing agents, play key roles in disease progression. Controlled delivery of antioxidants is therapeutically relevant in such oxidant‐stressed environments. Encapsulating small hydrophilic molecules into hydrophobic polymer microparticles via traditional emulsion methods has long been a challenge due to rapid mass transport of small molecules out of particle pores. We have developed a simple alteration to the existing water‐in‐oil‐in‐water (W/O/W) drug encapsulation method that dramatically improves loading efficiency: doping external water phases with drug to mitigate drug diffusion out of the particle during fabrication. PLGA microparticles with diameters ranging from 0.6 to 0.9 micrometers were fabricated, encapsulating high loads of 0.6–0.9 µm diameter PLGA microparticles were fabricated, encapsulating high loads of the antioxidant N‐acetylcysteine (NAC), and released active, ROS‐scavenging NAC for up to 5 weeks. Encapsulation efficiencies, normalized to the theoretical load of traditional encapsulation without doping, ranged from 96% to 400%, indicating that NAC‐loaded external water phases not only prevented drug loss due to diffusion, but also doped the particles with additional drug. Antioxidant‐doped particles positively affected the metabolism of oligodendrocyte progenitor cells (OPCs) under H2O2‐mediated oxidative stress when administered both before (protection) or after (rescue) injury. Antioxidant doped particles improved outcomes of OPCs experiencing multiple doses of H2O2 by increasing the intracellular glutathione content and preserving cellular viability relative to the injury control. Furthermore, antioxidant‐doped particles preserve cell number, number of process extensions, cytoskeletal morphology, and nuclear size of H2O2‐stressed OPCs relative to the injury control. These NAC‐doped particles have the potential to provide temporally‐controlled antioxidant therapy in neurodegenerative disorders such as multiple sclerosis (MS) that are characterized by continuous oxidative stress.
Simultaneous determination of glaucocalyxin A and glaucocalyxin B in rat plasma by LC‐MS/MS and its application to a pharmacokinetic study after oral administration of Rabdosia japonica extract
Authors: Huang Weili , Guan Xiaohui , Lv Yongchen 
Published: September 2017

AbstractA specific and sensitive liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the analysis of glaucocalyxin A and glaucocalyxin B in rat plasma using praeruptorin A as an internal standard. Separation was performed on a Hypurity C18 column (2.1 × 50 mm, 5 μm) with isocratic elution using 0.2% formic acid in water–acetonitrile (20:80, v/v). Mass spectrometric detection was conducted using selected reaction monitoring via an electrospray ionization source. Both analytes exhibited good linearity within their concentration ranges (r2 > 0.9932). The lower limit of quantitation of glaucocalyxin A and glaucocalyxin B was 1.10 ng/mL. Intra‐ and inter‐day precision exhibited an RSD within 14.5%, and the accuracy (RE) ranged from –12.1 to 15.0% at the lower limit of quantitation and three quality control levels. The developed assay was successfully applied to a pharmacokinetic study of glaucocalyxin A and glaucocalyxin B in rats after oral administration of Rabdosia japonica extract.
Parent Thioketene S‐Oxide H2CCSO: Gas‐Phase Generation, Structure, and Bonding Analysis
Authors: Wu Zhuang , Xu Jian , Sokolenko Liubov , Yagupolskii Yurii L. , Feng Ruijuan , Liu Qian , Lu Yan , Zhao Lili , Fernández Israel , Frenking Gernot , Trabelsi Tarek , Francisco Joseph S. , Zeng Xiaoqing 
Published: September 2017

AbstractThe parent thioketene S‐oxide H2CCSO has been generated in the gas phase through flash vacuum pyrolysis (ca. 1000 K) of vinyl sulfoxide H2CC(Br)−S(O)CF3 via the intermediacy of a novel vinyl sulfinyl radical H2C=C(Br)−SO (syn and anti conformers). Upon irradiation at 266 nm, H2CCSO decomposes into HCCH/SO and H2CS/CO in cryogenic Ar matrix. Whereas, visible‐light irradiations result in syn↔anti conformational interconversion in H2C=C(Br)−SO. The molecular structures of H2CCSO and isomers are computationally studied at the CCSD(T)‐F12/VTZ‐F12 level of theory, and the bonding properties of H2CCSO are analyzed with the EDA‐NOCV method at the M06‐2X/TZ2P level.
Reduction of Carbonyl Groups by Uranium(III) and Formation of a Stable Amide Radical Anion
Authors: Mullane Kimberly C. , Cheisson Thibault , Nakamaru‐Ogiso Eiko , Manor Brian C. , Carroll Patrick J. , Schelter Eric J. 
Published: September 2017

AbstractMethyl benzoate, N,N‐dimethylbenzamide, and benzophenone were reduced by UIII[N(SiMe3)2]3 resulting in uranium(IV) products. Reduction of benzophenone lead to UIV[OC⋅Ph2)][N(SiMe3)2]3, (1.1) which forms the dinuclear complex, [N(SiMe3)2]3UIV(OCPhPh‐CPh2O)UIV[N(SiMe3)2]3 (1.2), through coupling of the ketyl radical species upon crystallization. Reaction of N,N‐dimethylbenzamide with UIII[N(SiMe3)2]3 resulted in UIV[OC⋅(Ph)(NMe2)][N(SiMe3)2]3 (2), a uranium(IV) compound and the first example of a charge‐separated amide radical. In the case of methyl benzoate, the reduction resulted in UIV(OMe)[N(SiMe3)2]3 (3) and benzaldehyde as the reduced organic fragment. Compound 2 showed the ability to act as a uranium(III) synthon in its reactivity with trimethylsilyl azide, a reaction that yielded UV(=NSiMe3)[N(SiMe3)2]3. Additionally, 2 was reduced with potassium graphite resulting in [U(μ‐O)[O=C(NMe2)(Ph)][N(SiMe3)2]2]2 (4), a dinuclear uranium compound bridged by oxo ligands. Reduction of 2 in the presence of 15‐crown‐5 afforded isolation of the mono‐oxo compound, [(15‐crown‐5)2K][UO[N(SiMe3)2]3] (5). The results expand the reduction capabilities of UIII complexes and demonstrate a strategy for isolating novel metal‐stabilized radicals.
Histopathological and genotypic characterization of metastatic colorectal carcinoma with PD‐L1 (CD274)‐expression: Possible roles of tumour micro environmental factors for CD274 expression
Authors: Inaguma Shingo , Lasota Jerzy , Felisiak‐Golabek Anna , Kowalik Artur , Wang Zengfeng , Zieba Sebastian , Kalisz Joanna , Ikeda Hiroshi , Miettinen Markku 
Published: September 2017

AbstractAberrant PD‐L1 (CD274) expression has been described in different types of tumour and linked to tumour aggressiveness and a poor prognosis. In primary colorectal carcinomas (CRCs), CD274 expression was reported to be associated with mismatch repair (MMR)‐deficiency, BRAF mutation, and “stem‐like” immunophenotype defined by down‐regulation of homeobox protein CDX2 and membranous expression of activated leukocyte cell adhesion molecule (ALCAM). However, the immunophenotype and genotype of CD274‐positive metastatic CRC have not been extensively analysed. In this study, 189 CRC metastases were evaluated immunohistochemically for CD274, MMR proteins, CDX2, and ALCAM expression. Immunostaining for CD4, CD8, and FOXP3 was also performed to characterize tumour‐associated immune cells. In addition, 34 arbitrarily selected lesions were genotyped using Sanger‐ and next‐generation sequencing. Univariate analyses showed no clear association between CD274 expression and clinicopathological parameters including MMR‐deficiency or “stem‐like” immunophenotype after adjustment for multiple testing. Comparison of the clinicopathological profiles of CD274‐positive primary and metastatic tumours revealed in the latter younger age of occurrence (60.9 ± 13.3 versus 72.6 ± 13.1 years, p = 0.001), cytoplasm‐dominant CD274 expression (p < 0.001), infrequent MMR‐deficiency (p < 0.001), and common KRAS mutations (54%, p < 0.001). In five cultured colon cancer cell lines, CD274 was expressed and modulated after exogenous exposure to IFNγ and TGF‐β1. Thus, CD274 regulation mechanisms might include tumour micro environmental factors. Based on significantly different characteristics in CD274‐positive metastatic and primary CRCs, evaluation of metastases should also be considered when planning immune checkpoint inhibitor therapy.
Experimente zu Eigenschaften von Nanomaterialien in Chemieunterricht und Schülerlabor
Authors: Wilke Timm , Dege Janina , Waitz Thomas 
Published: September 2017

AbstractIm Beitrag werden Perspektiven zum Thema Nanotechnologie im Chemieunterricht beschrieben, die im Rahmen Fachdidaktischer Transferforschung innerhalb einer Kooperation zwischen Fachdidaktik und Fachwissenschaft erarbeitet wurden. Ein besonderer Fokus wird dabei auf die experimentelle Erschließung von Eigenschaften verschiedener nanoskaliger Materialien wie etwa Titandioxid, Zinkoxid und Silica gelegt. Über die Verwendung dieser Materialien können Themen wie Adsorption, Fluoreszenz, (Photo‐) Katalyse und Toxizität mit einem aktuellen Forschungsthema vernetzt und in eine Vielfalt von Kontexten eingebettet werden.
Don't let perfect be the enemy of good: How to improve prognostic communication in pediatric oncology
Authors: Lee Brittany M. , Rosenberg Abby R. 
Published: September 2017

Parents of children with cancer desire detailed and honest information about their child's prognosis throughout the cancer experience and regardless of race or ethnicity. This essay describes barriers and opportunities for pediatric oncologists to meet their obligations of prognostic disclosure.See also pages 3995‐4003 and 4031‐8.
Disparities in prognosis communication among parents of children with cancer: The impact of race and ethnicity
Authors: Ilowite Maya F. , Cronin Angel M. , Kang Tammy I. , Mack Jennifer W. 
Published: September 2017

BACKGROUNDMost parents of children with cancer say they want detailed information about their child's prognosis. However, prior work has been conducted in populations of limited diversity. The authors sought to evaluate the impact of parental race/ethnicity on prognosis communication experiences among parents of children with cancer.METHODSIn total, 357 parents of children with cancer and the children's physicians were surveyed at Dana‐Farber Cancer Institute/Boston Children's Hospital and Children's Hospital of Philadelphia. Outcome measures were parental preferences for prognostic information, physician beliefs about parental preferences, prognosis communication processes, and communication outcomes. Associations were assessed by logistic regression with generalized estimating equations to correct for physician clustering.RESULTSTwo hundred eighty‐one parents (79%) were white, 23 (6%) were black, 29 (8%) were Hispanic, and 24 (7%) were Asian/other. Eighty‐seven percent of parents wanted as much detail as possible about their child's prognosis, with no significant differences by race/ethnicity (P = .75). However, physician beliefs about parental preferences for prognosis communication varied based on parent race/ethnicity, with physicians considering black and Hispanic parents less interested in details about prognosis than whites (P = .003). Accurate understanding of a less favorable prognosis was greater among white (49%) versus nonwhite parents (range, 20%‐29%), although this difference was not statistically significant (P = .14).CONCLUSIONSMost parents, regardless of racial and ethnic background, want detailed prognostic information about their child's cancer. However, physicians underestimate the information needs of black and Hispanic parents. To meet parents' information needs, physicians should ask about parents' information preferences before prognosis discussions. Cancer 2017;123:3995‐4003. © 2017 American Cancer Society.
Electrochemical CO2 Reduction: A Classification Problem
Authors: Bagger Alexander , Ju Wen , Varela Ana Sofia , Strasser Peter , Rossmeisl Jan 
Published: September 2017

AbstractIn this work, we propose four non‐coupled binding energies of intermediates as descriptors, or “genes”, for predicting the product distribution in CO2 electroreduction. Simple reactions can be understood by the Sabatier principle (catalytic activity vs. one descriptor), while more complex reactions tend to give multiple very different products and consequently the product selectivity is a more complex property to understand. We approach this, as a logistical classification problem, by grouping metals according to their major experimental product from CO2 electroreduction: H2, CO, formic acid and beyond CO* (hydrocarbons or alcohols). We compare the groups in terms of multiple binding energies of intermediates calculated by density functional theory. Here, we find three descriptors to explain the grouping: the adsorption energies of H*, COOH*, and CO*. To further classify products beyond CO*, we carry out formaldehyde experiments on Cu, Ag, and Au and combine these results with the literature to group and differentiate alcohol or hydrocarbon products. We find that the oxygen binding (adsorption energy of CH3O*) is an additional descriptor to explain the alcohol formation in reduction processes. Finally, the adsorption energy of the four intermediates, H*, COOH*, CO*, and CH3O*, can be used to differentiate, group, and explain products in electrochemical reduction processes involving CO2, CO, and carbon–oxygen compounds.
Transport Matters: Boosting CO2 Electroreduction in Mixtures of [BMIm][BF4]/Water by Enhanced Diffusion
Authors: Rudnev Alexander V. , Fu Yong‐Chun , Gjuroski Ilche , Stricker Florian , Furrer Julien , Kovács Noémi , Vesztergom Soma , Broekmann Peter 
Published: September 2017

AbstractRoom‐temperature ionic liquids (RTILs) are promising new electrolytes for efficient carbon dioxide reduction. However, due to their high viscosity, the mass transport of CO2 in RTILs is typically slow, at least one order of magnitude slower than in aqueous systems. One possibility to improve mass transport in RTILs is to decrease their viscosity through dilution with water. Herein, defined amounts of water are added to 1‐butyl‐3methylimidazolium tetrafluoroborate ([BMIm][BF4]), which is a hydrophilic RTIL. Electrochemical measurements on quiescent and hydrodynamic systems both indicate enhanced CO2 electroreduction. This enhancement has its origin in thermodynamic/kinetic effects (the addition of water increases the availability of H+, which is a reaction partner of CO2 electroreduction) and in an increased rate of transport due to lower viscosity. Electrochemically determined diffusion coefficients for CO2 in [BMIm][BF4]/water systems agree well with values determined by NMR spectroscopy.
Porphyrins as Multifunctional Interconnects in Networks of ZnO Nanoparticles and their Application in Dye‐Sensitized Solar Cells
Authors: Düring Jasmin , Kunzmann Andreas , Killian Manuela S. , Costa Rubén D. , Guldi Dirk M. , Gröhn Franziska 
Published: September 2017

AbstractZnO nanoparticles of 2.6 to 4.0 nm in size were interconnected by meso‐tetra(4‐carboxyphenyl)porphyrin (TCPP) for the realization of novel ZnO–TCPP networks, reaching lateral dimensions ranging from 50 to 800 nm. The resulting ZnO–TCPP networks were probed by dynamic light‐scattering experiments, transmission electron microscopy, and spectroscopy, and were also tested as photoactive top layers in TiO2 and ZnO dye‐sensitized solar cells (DSSCs). Control over these ZnO–TCPP networks on top of the semiconductor electrodes enables efficiency increases of 10 % and 46 % for TiO2‐ and ZnO‐based photoelectrodes, respectively. In other words, effects, such as reducing the electron recombination and increasing the electron lifetime, document the benefits of using tailored functional hybrid systems in DSSCs.
Power‐efficient burst‐mode RF transmitter based on reference‐adaptive multilevel pulse‐width modulation
Authors: Arian Amir , Jannesari Abumoslem 
Published: September 2017

SummaryBurst‐mode operation of power amplifier (PA) based on multilevel pulse‐width modulation (MPWM) has been frequently discussed as a potential solution to achieve higher efficiency in radio frequency (RF) transmitters. In this paper, a novel multilevel PWM modulator is proposed that utilizes adaptive triangular reference waveforms. As compared with conventional MPWM modulators, the proposed architecture provides significant wider design space such that the efficiency of system can be effectively optimized. A general transmitter architecture based on the proposed concept is analyzed in terms of power efficiency. Efficiency optimization procedures are presented according to input magnitude statistics. Based on the proposed modulator, an optimized 2.4‐GHz RF transmitter is designed in a 0.18‐μm complementary metal‐oxide‐semiconductor (CMOS) process. The circuit‐level simulations show that it delivers 25.8‐dBm peak output power with 46.1% peak efficiency. For a 20‐MHz worldwide interoperability for microwave access (WiMAX) signal with 8.5‐dB peak‐to‐average‐power ratio (PAPR), this transmitter achieves 28.8% (average) efficiency at 17.3‐dBm (average) output power with an error vector magnitude (EVM) of 2.97% rms.
High genetic risk scores for impaired insulin secretory capacity doubles the risk for type 2 diabetes in Asians and is exacerbated by Western‐type diets
Authors: Kim Da Sol , Kim Byoung Chul , Daily James W. , Park Sunmin 
Published: September 2017

AbstractBackgroundAsians have among the highest incidence of type 2 diabetes (T2DM) in the world, partly due to low β‐cell function, causing them to rapidly develop T2DM when insulin resistant. This study tested the hypothesis that genetic polymorphisms are responsible for the low β‐cell function and that dietary factors interact with the genes to exacerbate their risk of T2DM.MethodsWe selected 10 genetic variants of 5 genes involved in insulin secretion (CDKAL1, KCNQ1, IDE, HHEX, and ABCA1) from the genome‐wide association studies to calculate the genetic risk scores (GRSs) in 8842 Korean adults in the Ansan/Ansung cohort in the Korean Genome Epidemiology Study. The genetic risk score were divided into low, medium, and high groups, and the association between T2DM and the genetic risk score was measured using logistic regression. We also analysed the interaction between the genetic risk score and the nutrition intakes.ResultsThe individual genetic variants were positively associated with T2DM even when adjusted for covariates. Individuals with medium and high genetic risk score had higher T2DM risk by 1.68 and 2.17 folds compared to those with the low genetic risk score after adjusting for covariates. The increased risk was mainly associated with lower HOMA‐B, an indicator of insulin secretion capacity, but not HOMA‐IR, an indicator of insulin resistance. Subjects with high carbohydrate intakes and a medium genetic risk score did not have a higher risk of T2DM, and the risk was partially mitigated in the high genetic risk score group.ConclusionSeventy‐two percent of the Korean population had either medium or high genetic risk scores for impaired insulin secretion, which approximately doubled their risk of type 2 diabetes, and the risk was exacerbated by consuming a low carbohydrate Western‐style diets.
What mediates tree mortality during drought in the southern Sierra Nevada?
Authors: Paz‐Kagan Tarin , Brodrick Philip G. , Vaughn Nicholas R. , Das Adrian J. , Stephenson Nathan L. , Nydick Koren R. , Asner Gregory P. 
Published: September 2017

AbstractSevere drought has the potential to cause selective mortality within a forest, thereby inducing shifts in forest species composition. The southern Sierra Nevada foothills and mountains of California have experienced extensive forest dieback due to drought stress and insect outbreak. We used high‐fidelity imaging spectroscopy (HiFIS) and light detection and ranging (LiDAR) from the Carnegie Airborne Observatory (CAO) to estimate the effect of forest dieback on species composition in response to drought stress in Sequoia National Park. Our aims were (1) to quantify site‐specific conditions that mediate tree mortality along an elevation gradient in the southern Sierra Nevada Mountains, (2) to assess where mortality events have a greater probability of occurring, and (3) to estimate which tree species have a greater likelihood of mortality along the elevation gradient. A series of statistical models were generated to classify species composition and identify tree mortality, and the influences of different environmental factors were spatially quantified and analyzed to assess where mortality events have a greater likelihood of occurring. A higher probability of mortality was observed in the lower portion of the elevation gradient, on southwest‐ and west‐facing slopes, in areas with shallow soils, on shallower slopes, and at greater distances from water. All of these factors are related to site water balance throughout the landscape. Our results also suggest that mortality is species‐specific along the elevation gradient, mainly affecting Pinus ponderosa and Pinus lambertiana at lower elevations. Selective mortality within the forest may drive long‐term shifts in community composition along the elevation gradient.
Long‐term trends in trait structure of riverine communities facing predation risk increase and trophic resource decline
Authors: Latli Adrien , Descy Jean‐Pierre , Mondy Cédric P. , Floury Mathieu , Viroux Laurent , Otjacques William , Marescaux Jonathan , Depiereux Eric , Ovidio Michael , Usseglio‐Polatera Philippe , Kestemont Patrick 
Published: September 2017

AbstractMany large European rivers have undergone multiple pressures that have strongly impaired ecosystem functioning at different spatial and temporal scales. Global warming and other environmental changes have favored the success of invasive species, deeply modifying the structure of aquatic communities in large rivers. Some exogenous species could alter trophic interactions within assemblages by increasing the predation risk for potential prey species (top‐down effect) and limiting the dynamics of others via resource availability limitation (bottom‐up effect). Furthermore, large transboundary rivers are complex aquatic ecosystems that have often been poorly investigated so that data for assessing long‐term ecological trends are missing. In this study, we propose an original approach for investigating long‐term combined effects of global warming, trophic resource decrease, predation risk, and water quality variations on the trait‐based structure of macroinvertebrate and fish assemblages over 26 yr (1985–2011) and 427‐km stretch of the river Meuse (France and Belgium). The study of temporal variations in biological, physiological, and ecological traits of macroinvertebrate and fish allowed identifying community trends and distinguishing impacts of environmental perturbations from those induced by biological alterations. We provide evidence, for this large European river, of an increase in water temperature (close to 1°C) and a decrease in phytoplankton biomass (−85%), as well as independent effects of these changes on both invertebrate and fish communities. The reduction of trophic resources in the water column by invasive molluscs has dramatically affected the density of omnivorous fish in favor of invertebrate feeders, while scrapers became the major feeding guild among invertebrates. Macroinvertebrate and fish communities have shifted from large‐sized organisms with low fecundity to prolific, small‐sized organisms, with early maturity, as a response to increased predation pressure.