bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Synthesis of Composition‐Controlled Graphene‐Supported PtPd Alloy Nanocatalysts and Their Applications in Methanol Electro‐Oxidation and Lithium‐Oxygen Batteries
Authors: Ye Seong Ji , Bui Hieu Trung , Kim Young Yun , Liao Kin , Cho Kyeong Min , Jung Hee‐Tae , Kang Yongku , Kim Do Youb , Park O Ok 
Published: October 2017

AbstractA new and simple approach is reported for the synthesis of uniformly dispersed PtPd alloy nanocatalysts supported on graphene nanoplatelets (GNPs) (PtPd‐GNPs) through the introduction of bifunctional materials, which can modify the GNP surface and simultaneously reduce metal ions. With the use of poly(4‐styrenesulfonic acid), poly(vinyl pyrrolidone), poly(diallyldimethylammonium chloride), and poly(vinyl alcohol) as bifunctional materials, PtPd‐GNPs can be produced through a procedure that is far simpler than previously reported methods. The as‐prepared nanocrystals on GNPs clearly exhibit uniform PtPd alloy structures of around 2 nm in size, which are strongly anchored and well distributed on the GNP sheets. The Pt/Pd atomic ratio and loading density of the nanocrystals on the GNPs are controlled easily by changing the metal precursor feed ratio and the mass ratio of GNP to the metal precursor, respectively. As a result of the synergism between Pt and Pd, the as‐prepared PtPd‐GNPs exhibit markedly enhanced electrocatalytic performance during methanol electro‐oxidation compared with monometallic Pt‐GNP or commercially available Pt/C. Furthermore, the PtPd‐GNP nanocatalysts also show greatly enhanced catalytic activity toward the oxygen reduction/evolution reaction in a lithium‐oxygen (Li‐O2) process, resulting in greatly improved cycling stability of a Li‐O2 battery.
Highly Stereoselective Strecker Synthesis Induced by a Slight Modification of Benzhydrylamine from Achiral to Chiral
Authors: Takamatsu Naoya , Aiba Shohei , Yamada Takuya , Tokunaga Yuji , Kawasaki Tsuneomi 
Published: October 2017

Abstract2‐Methylbenzhydrylamine is a chiral variant of achiral benzhydrylamine; however, the chirality formed from the small difference between the phenyl and o‐tolyl groups is not expected to induce sufficient stereoselectivity in conventional homogeneous reactions. Initiated by the spontaneous formation and asymmetric amplification of the enantioenriched N‐benzhydryl‐α‐aminonitrile forming conglomerate, we here report that (S)‐ and (R)‐configured title amine, upon the Strecker reaction with achiral aldehydes and HCN, afford the corresponding α‐aminonitriles with up to >99.5 % diastereomeric excess, in conjunction with an enhancement of chirality in the solid state. l‐Alanine with 98 % ee was synthesized from the (S)‐amine by using the method discussed here. Achiral aromatic and heteroaromatic aldehydes could also be successfully utilized to afford chiral α‐aminonitriles in a highly stereoselective manner. The stereodivergent synthesis of styrylglycine nitriles has also been accomplished by using racemic and enantioenriched 2‐methylbenzhydrylamine. Thus, accompanied with a small rearrangement of the common substrate from achiral toward chiral, the present reactions induce an enhancement of chirality, and expands the concept of stereoselective synthesis to increase the opportunity to access highly enantioenriched compounds such as α‐amino acids.
Applications of nanotechnology in oil and gas industry: Progress and perspective
Authors: Peng Baoliang , Tang Juntao , Luo Jianhui , Wang Pingmei , Ding Bin , Tam Kam Chiu 
Published: October 2017

AbstractNanotechnology has been successfully implemented in many applications, such as nanoelectronics, nanobiomedicine, and nanodevices. However, this technology has rarely been applied to the oil and gas industry, especially in upstream exploration and production. The oil and gas industry needs to improve oil recovery and exploit unconventional resources. The cost of research and oil production is under immense pressure, and it is becoming more difficult to justify such investment when the crude oil price is weak and depressed. There is a widespread belief that nanotechnology may be exploited to develop novel nanomaterials with enhanced performance to combat these technological barriers. Increasing funding resources from governmental and global oil industry have been allocated to exploration, drilling, production, refining, and wastewater treatment. For example, nanosensors allow for precise measurement of reservoir conditions. Nanofluids prepared using functional nanomaterials may exhibit better performance in oil production processes, and nanocatalysts have improved the efficiency in oil refining and petrochemical processes. Nanomembranes enhance oil, water and gas separation, oil and gas purification, and the removal of impurities from wastewater. Functional nanomaterials can play an important role in the production of smart, reliable, and more durable equipment. In this review paper, we summarize the research progress and prospective applications of nanotechnology and nanomaterials in the oil and gas industry.
Flameless combustion behaviour of preheated pulverized coal
Authors: Ouyang Ziqu , Liu Wen , Zhu Jianguo 
Published: October 2017

AbstractA method for stable flameless combustion of pulverized coal based on coal preheating was recently proposed. The method involves the initial heating of pulverized coal to a temperature above 800 °C. The heated coal is then transferred into a combustion chamber, where it is mixed with secondary air injected at a high velocity to achieve flameless combustion. The flameless combustion behaviour of the preheated pulverized coal was experimentally investigated in a lab‐scale test apparatus. The results showed that stable flameless combustion of bituminous coal and two different anthracite coals could be achieved. The temperature of the combustion chamber was also observed to be homogeneous. The peak temperature was below 1250 °C, while the average combustion temperature was about 1150 °C. The normalized root mean square temperature fluctuation over the combustion chamber is 7.0 %, 6.7 %, and 6.8 % for the three different coals. The colour of the entire combustion chamber was a faint yellow with no obvious flame front surface observed. Fuel preheating was found to be effective for improving the combustion efficiency, with values of 99.2 %, 98.3 %, and 97.9 % achieved for bituminous coal and two different anthracite coals, respectively. The experimental data further revealed that the NOX emissions for all the considered coals were very low compared to the corresponding cases of traditional combustion, with the values for the different coal types also significantly varying. The NOX emissions were determined to be 232, 187, and 165 mg/Nm3 (6 % O2) for bituminous coal and two different anthracite coals, respectively.
Optimization of commercially available Zika virus antibodies for use in a laboratory‐developed immunohistochemical assay
Authors: Bollweg Brigid C , Silva‐Flannery Luciana , Spivey Pamela , Hale Gillian L 
Published: October 2017

AbstractZika virus (ZIKV) infection during pregnancy can cause adverse fetal outcomes and severe irreversible congenital birth defects including microcephaly. Immunohistochemistry (IHC) is a valuable diagnostic tool for detecting ZIKV antigens in tissues from cases of fetal loss in women infected with ZIKV, and for providing insights into disease pathogenesis. As a result, there is increasing demand for commercially available ZIKV antibodies for use in IHC assays. ZIKV antibodies were selected and obtained from commercial sources to include both mouse and rabbit hosts, and a variety of antigenic targets. Pretreatment conditions and antibody concentrations resulting in optimal immunohistochemical staining were determined using ZIKV cell control and polymerase chain reaction (PCR)‐confirmed ZIKV case control material (fetal brain tissue). Cross‐reactivity of the antibodies against other flaviviruses (dengue virus serogroups 1–4, yellow fever virus, Japanese encephalitis virus, West Nile virus) and chikungunya virus was also evaluated. Immunostaining using the commercially available antibodies was compared to a previously validated ZIKV IHC assay used for primary diagnosis. Four antibodies demonstrated optimal staining similar to the previously validated ZIKV IHC assay. Two of the four antibodies cross‐reacted with dengue virus, while the other two antibodies showed no cross‐reactivity with dengue, other flaviviruses, or chikungunya virus. Differences in the cross‐reactivity profiles could not be entirely explained by the antigenic target. Commercially available ZIKV antibodies can be optimized for use in IHC testing to aid in ZIKV diagnostic testing and an evaluation of tissue tropism.
Single‐Assay Profiling of Nucleosome Occupancy and Chromatin Accessibility
Authors: Cook April , Mieczkowski Jakub , Tolstorukov Michael Y. 
Published: October 2017

AbstractThis unit describes a method for determining the accessibility of chromatinized DNA and nucleosome occupancy in the same assay. Enzymatic digestion of chromatin using micrococcal nuclease (MNase) is optimized for liberation, retrieval, and characterization of DNA fragments from chromatin. MNase digestion is performed in a titration series, and the DNA fragments are isolated and sequenced for each individual digest independently. These sequenced fragments are then collectively analyzed in a novel bioinformatics pipeline to produce a metric describing MNase accessibility of chromatin (MACC) and nucleosome occupancy. This approach allows profiling of the entire genome including regions of open and closed chromatin. Moreover, the MACC protocol can be supplemented with a histone immunoprecipitation step to estimate and compare both histone and non‐histone DNA protection components. © 2017 by John Wiley & Sons, Inc.
Cationic Vacancy Defects in Iron Phosphide: A Promising Route toward Efficient and Stable Hydrogen Evolution by Electrochemical Water Splitting
Authors: Kwong Wai Ling , Gracia‐Espino Eduardo , Lee Cheng Choo , Sandström Robin , Wågberg Thomas , Messinger Johannes 
Published: October 2017

AbstractEngineering the electronic properties of transition metal phosphides has shown great effectiveness in improving their intrinsic catalytic activity for the hydrogen evolution reaction (HER) in water splitting applications. Herein, we report for the first time, the creation of Fe vacancies as an approach to modulate the electronic structure of iron phosphide (FeP). The Fe vacancies were produced by chemical leaching of Mg that was introduced into FeP as “sacrificial dopant”. The obtained Fevacancy‐rich FeP nanoparticulate films, which were deposited on Ti foil, show excellent HER activity compared to pristine FeP and Mg‐doped FeP, achieving a current density of 10 mA cm−2 at overpotentials of 108 mV in 1 m KOH and 65 mV in 0.5 m H2SO4, with a near‐100 % Faradaic efficiency. Our theoretical and experimental analyses reveal that the improved HER activity originates from the presence of Fe vacancies, which lead to a synergistic modulation of the structural and electronic properties that result in a near‐optimal hydrogen adsorption free energy and enhanced proton trapping. The success in catalytic improvement through the introduction of cationic vacancy defects has not only demonstrated the potential of Fe‐vacancy‐rich FeP as highly efficient, earth abundant HER catalyst, but also opens up an exciting pathway for activating other promising catalysts for electrochemical water splitting.
Cancer‐related mRNA expression analysis using a novel flow cytometry‐based assay
Authors: Depreter Barbara , Philippé Jan , Meul Magali , Denys Barbara , Vandepoele Karl , De Moerloose Barbara , Lammens Tim 
Published: October 2017

BackgroundCancer‐related gene expression data mostly originate from unfractionated bulk samples, leading to “expression averaging” of heterogeneous populations. Multicolor flow cytometry (FCM) may distinguish heterogeneous populations based on the phenotypic characterization of single‐cells, but is not applicable for RNA targets. Here, we evaluated the PrimeFlow™ RNA assay, a novel FCM‐based assay designed to measure gene expressions, in two cancer entities with high and low RNA target levels.MethodsNeuroblastoma (NB) cell lines were studied for MYCN gene expression by PrimeFlow™ and compared with the gold standard, RT‐qPCR. Dilution series of NB cells (0.10–11%) were prepared to evaluate performance in small cell populations. Diagnostic material of de novo acute myeloid leukemia (AML) patients was used to measure Wilms' tumor 1 (WT1) expression in bulk leukemic cells and rare subsets, e.g. leukemic stem cells (LSCs). FCM analysis was performed on a FACSCanto II (BD Biosciences) using Infinicyt™ (Cytognos®) for data analysis. mRNA expression was reported by normalized mean fluorescence intensity (MFI) values and staining indices.ResultsMYCN mRNA quantified by PrimeFlow™ significantly correlated with RT‐qPCR and remained detectable in small (0.1%) populations. Using PrimeFlowTM, WT1 levels were shown to be significantly higher in AML patient samples with WT1 overexpression, previously defined by RT‐qPCR. Moreover, WT1 overexpression was distinguishable between heterogeneous cell populations and remained measurable in rare LSCs.ConclusionPrimeFlow™ is a sensitive technique to investigate mRNA expressions, with high concordance to RT‐qPCR. High (MYCN) and subtle (WT1) overexpressed mRNA targets can be quantified in heterogeneous and rare subpopulations e.g. LSCs. © 2017 International Clinical Cytometry Society
Bottom‐up control of parasites
Authors: Johnson David Samuel , Heard Richard 
Published: October 2017

AbstractParasitism is a fundamental ecological interaction. Yet we understand relatively little about the ecological role of parasites compared to the role of free‐living organisms. Bottom‐up theory predicts that resource enhancement will increase the abundance and biomass of free‐living organisms. Similarly, parasite abundance and biomass should increase in an ecosystem with resource enhancement. We tested this hypothesis in a landscape‐level experiment in which salt marshes (60,000 m2each) received elevated nutrient concentrations via flooding tidal waters for 11 yr to mimic eutrophication. Nutrient enrichment elevated the densities of the talitrid amphipod,Orchestia grillus, and the density and biomass of its trematode parasite,Levinseniella byrdi. Strikingly,L. byrdiprevalence increased over time, up to 13 times higher in nutrient‐enriched marshes (30%) relative to the mean prevalence in reference marshes (2.4%). The biomass density of infected amphipods was, on average, 11 times higher in nutrient‐enriched marshes (1.1 kg/ha) than in reference marshes (0.1 kg/ha), when pooling across all years.Orchestia grillusbiomass comprises 67% of the arthropod community biomass; thus, nutrient enrichment elicits a substantial surge in parasitized biomass in the arthropod community. If our results are typical, they suggest that eutrophication can increase parasite abundance and biomass with chronic resource enhancement. Therefore, minimizing aquatic nutrient pollution may prevent outbreaks of parasites with aquatic hosts.
A parsimonious approach for modeling uncertainty within complex nonlinear relationships
Authors: Strimbu Bogdan M. , Amarioarei Alexandru , Paun Mihaela 
Published: October 2017

AbstractAdvancements in information technology led environmental scientists to the illusion that efforts should be mainly focused on developing models that reduce uncertainty rather than on models adjusted to the existing uncertainty. As a result, environmental relationships are represented by non‐parsimonious and suboptimal models, which in many instances could be even wrong. The objective of this research was to provide scientists focused on modeling ecosystem processes with a procedure that supplies parsimonious correct results. The procedure transforms the response variable to achieve a linear model and the normality of the residuals. After the parameters of the transformed model are estimated, the bias induced by back‐transforming is corrected. We have computed the bias corrections for 11 of the most popular functions from the power, trigonometric, and hyperbolic families by considering the truncated normal distribution, when necessary. Using generated data, we have shown that the proposed procedure supplies unbiased results. We have identified a sample size artifact of data generation such that when the variance increases the truncation of distribution starts altering the corrections of predicted values, sometimes by more than 50% from the actual values. Our results indicate that uncertainty, measured by variance, impacts the analysis in a non‐intuitive way when the defining domain of the response variable is restricted. The subtle way of influencing the development of complex nonlinear models by uncertainty advocates the usage of parsimonious linear models, which are less sensitive to the method of processing data. Finally, ecosystem processes should be modeled with strategies that consider not only processes and computation aspects, but also uncertainty, in particularly reducing variance to levels with no significant impact on the results.
Critical loads of atmospheric N deposition for phytoplankton nutrient limitation shifts in western U.S. mountain lakes
Authors: Williams Jason J. , Lynch Jason A. , Saros Jasmine E. , Labou Stephanie G. 
Published: October 2017

AbstractIn many oligotrophic mountain lakes, anthropogenic atmospheric nitrogen (N) deposition has increased concentrations of N, a key limiting nutrient, and thereby shifted phytoplankton biomass growth from N limitation to P limitation. In the western United States, the critical load N deposition rate for these shifts has not been quantified. We synthesized existing mountain lake chemistry, nutrient limitation bioassay, and N deposition data to estimate N critical loads for shifts from N to P limitation of phytoplankton biomass growth. Data from bioassays in 47 mountain lakes were used to define biological (RR‐N/RR‐P = 1) and chemical (NO3, DIN, DIN:TP) thresholds above which biomass P limitation is more likely than N limitation. Logistic regression was used to calculate critical loads as the total N deposition rate with >50% probability of exceeding biological or chemical thresholds, and thus where P limitation is more likely than N limitation. Logistic regression models were developed with N deposition as the only predictor and with both N deposition and watershed characteristics as predictors. Logistic model performance was evaluated by comparing predicted and observed chemical threshold exceedances in 108 mountain lakes. Across models, estimated critical loads ranged from 2.8 to 5.2 kg total N·ha−1·yr−1. The best‐performing model was a univariate logistic model predicting NO3 threshold exceedance, with N deposition as the only predictor. This model yielded a critical load of 4.1 kg total N·ha−1·yr−1 and accurately predicted NO3 threshold exceedance in 69% of lakes. We applied this critical load to an independent sample of 385 mountain lakes with NO3 data to estimate the frequency it would fail to predict a limitation shift—cases where the NO3 threshold for biomass shifts was exceeded, but the critical load was not. The false‐negative rate was 13% across the western United States, but was higher (22%) in the Sierras. Performance analyses suggest a 2.0 kg total N·ha−1·yr−1 critical load may avoid false negatives entirely. Critical loads presented here can be used to assess N deposition impacts on western U.S. mountain lakes, and associated performance information can be used to consider if presented critical loads are adequate for specific management applications.
Disturbance and diversity in a continental archipelago: a mechanistic framework linking area, height, and exposure
Authors: Neufeld Christopher J. , Starko Samuel , Burns Kevin C. 
Published: October 2017

AbstractSpecies–area relationships (SARs) are among the most general patterns in nature. Yet, significant variation in species richness often remains after accounting for area, especially for small islands. One factor thought to influence species richness on small islands is disturbance from the combined influence of tides and waves. Here, we derive a quantitative framework for determining how ocean disturbance impacts island communities, which we then test in plant communities in a temperate island archipelago. We do so by applying some well‐developed techniques honed in the marine intertidal zone but rarely applied to studies on land. By estimating and adjusting for the effect of wave exposure on habitable island area, we dramatically improved the fit of the SAR for small islands, nearly doubling the amount of variation in species richness explained (from 37% to 69%). Our predictions of island occupancy also improved using this method. Our approach predicts that small islands (<100,000 m2) are the most affected by ocean‐borne disturbance. Given that many archipelagos are susceptible to wave disturbance, future studies should consider how ocean‐borne disturbances arising from the matrix might interact with sampling area to influence patterns of species richness on small islands.
Composted manure application promotes long‐term invasion of semi‐arid rangeland by Bromus tectorum
Authors: Blumenthal Dana M. , LeCain Daniel R. , Augustine David J. 
Published: October 2017

AbstractNutrient‐rich organic waste derived from sewage treatment facilities or livestock manure is often applied to rangelands of western North America to increase soil fertility, forage production, forage quality, and soil carbon storage. This practice can have a number of undesirable side effects, however, including plant invasion. While characteristics of both rangeland ecosystems and invasive plants suggest that organic waste application might often promote invasion, results to date are mixed, perhaps due in part to the paucity of long‐term studies. Here, we describe the long‐term (22 yr) effects of three types of organic waste—composted biosolids, composted cattle manure, and fresh cattle manure—on plant productivity and invasion in native mixed‐grass prairie. Although composted manure and biosolids increased plant productivity and forage quality in the second year of the study, these effects did not persist. In contrast, Bromus tectorum (cheatgrass), which invaded the study site over the course of the experiment, was strongly facilitated by composted manure addition, with particularly large effects observed in years 17 and 22. These results show that nutrient‐rich organic waste can favor invasive species even in the relatively invasion‐resistant grasslands of the western Great Plains. They also demonstrate that effects of organic waste on invasion can become apparent quite gradually and persist for decades following the initial organic waste application. Together, results from experimental additions of organic and inorganic nutrients to native rangelands suggest that the risk of promoting invasive species is significant, and should be considered in programs that apply organic waste to rangelands of western North America.