bluuebunny/crossref_metadata_2025_split huggingface dataset:
Composite Metal Oxide‐Carbon Nanotube Electrocatalysts for the Oxygen Evolution and Oxygen Reduction Reactions
Authors: Luo Wenjing , Wang Jiaxin , Hu Jun , Ji Yuanchun , Streb Carsten , Song Yu‐Fei 
Published: June 2018

AbstractElectrocatalysts capable of performing both the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) are key components for energy technologies including fuel cells, and water electrolysis. High‐performance catalysts based on earth abundant components are therefore a prime research theme. Herein, we report the development of a series of novel composites based on nanostructured iron‐doped CoWO4 particles electrically linked to conductive carbon nanotubes (CNTs) using a facile one‐pot hydrothermal method. It is shown that tuning of the iron content of Co1–xFexWO4−CNT composites (x=0–1) allows structural and reactivity control. The Co1–xFexWO4−CNT composites are active and stable OER and ORR electrocatalysts, and follow the Sabatier principle. For Co0.5Fe0.5WO4−CNT, minimum overpotentials of η=290 mV and low Tafel slopes of 42 mV dec−1 are achieved at a current density of j=10 mA cm−2 for OER, and the Co0.5Fe0.5WO4−CNT shows high catalytic activity for ORR with half‐wave potential of 0.74 V. As such, the composites show high potential as OER and ORR electrocatalysts, so that technologically viable, noble‐metal‐free, tunable electrocatalysts with relevance for alkaline water electrolysis can be designed from the bottom up.
Electroanalytic Aspects of Single‐Entity Collision Methods for Bioanalytical and Environmental Applications
Authors: Andreescu Daniel , Kirk Kevin A. , Narouei Farideh Hosseini , Andreescu Silvana 
Published: June 2018

AbstractSingle‐entity electrochemistry based on measurements of collision events at electrode surfaces is a rapidly developing field which provides extensive capabilities for detection and characterization of a variety of materials including organic and inorganic nanoparticles (NPs) and nanostructures as well as biologicals. The method has demonstrated promising potential for the analysis of catalytic activity, physicochemical parameters, fundamental surface properties, functionalization and reactivity of NPs. Here, the most recent developments and capabilities of this method as a novel tool for characterizing nanoscale properties are discussed, illustrating novel applications for assessing bioconjugation, designing ultrasensitive biosensing methods and monitoring processes of biological and environmental significance. The main advantages and limitations as compared to commonly used spectroscopy and imaging techniques are described, highlighting areas in which collision measurements can be used as a complementary approach to characterize properties of inorganic NPs, organic molecules, soft materials and biologicals, and develop methodologies for detection and quantification of analytes of interest in the bioanalytical, biological and environmental fields. An overview of potential applications in these fields is provided along with a critical discussion of future research needs and opportunities.
Quantitative and Orthogonal Formation and Reactivity of SuFEx Platforms
Authors: Gahtory Digvijay , Sen Rickdeb , Pujari Sidharam , Li Suhua , Zheng Qinheng , Moses John E. , Sharpless K. Barry , Zuilhof Han 
Published: June 2018

AbstractThe constraints of minute reactant amounts and the impossibility to remove any undesired surface‐bound products during monolayer functionalization of a surface necessitate the selection of efficient, modular and orthogonal reactions that lead to quantitative conversions. Herein, we explore the character of sulfur–fluoride exchange (SuFEx) reactions on a surface, and explore the applicability for quantitative and orthogonal surface functionalization. To this end, we demonstrate the use of ethenesulfonyl fluoride (ESF) as an efficient SuFEx linker for creating “SuFEx‐able” monolayer surfaces, enabling three distinct approaches to utilize SuFEx chemistry on a surface. The first approach relies on a di‐SuFEx loading allowing dual functionalization with a nucleophile, while the two latter approaches focus on dual (CuAAC–SuFEx/SPOCQ–SuFEx) click platforms. The resultant strategies allow facile attachment of two different substrates sequentially on the same platform. Along the way we also demonstrate the Michael addition of ethenesulfonyl fluoride to be a quantitative surface‐bound reaction, indicating significant promise in materials science for this reaction.
ESIPT‐Modulated Emission of Lanthanide Complexes: Different Energy‐Transfer Pathways and Multiple Responses
Authors: Sun Si‐Si , Wang Zheng , Wu Xiang Wen , Zhang Jian‐Hua , Li Chao‐Jie , Yin Shao‐Yun , Chen Ling , Pan Mei , Su Cheng‐Yong 
Published: June 2018

AbstractInvited for the cover of this issue is the group of Mei Pan at Sun Yat‐Sen University. The image depicts Canton Tower illuminated by the multicolor emission of Ln complexes. Read the full text of the article at 10.1002/chem.201802010.
A multi‐scale model of the coronary circulation applied to investigate transmural myocardial flow
Authors: Ge Xinyang , Yin Zhaofang , Fan Yuqi , Vassilevski Yuri , Liang Fuyou 
Published: June 2018

AbstractDistribution of blood flow in myocardium is a key determinant of the localization and severity of myocardial ischemia under impaired coronary perfusion conditions. Previous studies have extensively demonstrated the transmural difference of ischemic vulnerability. However, it remains incompletely understood how transmural myocardial flow is regulated under in vivo conditions. In the present study, a computational model of the coronary circulation was developed to quantitatively evaluate the sensitivity of transmural flow distribution to various cardiovascular and hemodynamic factors. The model was further incorporated with the flow autoregulatory mechanism to simulate the regulation of myocardial flow in the presence of coronary artery stenosis. Numerical tests demonstrated that heart rate (HR), intramyocardial tissue pressure (Pim), and coronary perfusion pressure (Pper) were the major determinant factors for transmural flow distribution (evaluated by the subendocardial‐to‐subepicardial (endo/epi) flow ratio) and that the flow autoregulatory mechanism played an important compensatory role in preserving subendocardial perfusion against reduced Pper. Further analysis for HR variation‐induced hemodynamic changes revealed that the rise in endo/epi flow ratio accompanying HR decrease was attributable not only to the prolongation of cardiac diastole relative to systole, but more predominantly to the fall in Pim. Moreover, it was found that Pim and Pper interfered with each other with respect to their influence on transmural flow distribution. These results demonstrate the interactive effects of various cardiovascular and hemodynamic factors on transmural myocardial flow, highlighting the importance of taking into account patient‐specific conditions in the explanation of clinical observations.
The role of breeding system in community dynamics: Growth and mortality in forests of different successional stages
Authors: Wang Yunyun , Freckleton Robert P. , Wang Bojian , Kuang Xu , Yuan Zuoqiang , Lin Fei , Ye Ji , Wang Xugao , Hao Zhanqing 
Published: June 2018

AbstractPlant sexual systems appear to play an important role in community assembly: Dioecious species are found to tend to have a higher propensity to colonize communities in early successional stages. Here, we test two demographic hypotheses to explain this pattern in temperate forests. First, we test demographic differences between hermaphrodite and dioecious species in stressful younger successional stages: Previous theory predicts that hermaphrodite seed production is more harmed in stressful environments than that of dioecious populations leading to an advantage for females of dioecious species. Second, in primary forest, we hypothesized that dioecious species would show demographic advantage over monomorphic ones. We used data from two temperate forest plots in Northeast China surveyed over 10 years to compare the rates of growth and mortality of tree species with contrasting breeding systems in both secondary and primary forests. We assessed the effect of breeding system on the growth‐mortality trade‐off, while controlling for other traits usually considered as correlates of growth and mortality rates. We show that in the secondary forest, dioecious species showed weak advantage in demographic rates compared with monomorphic species; dioecious species showed considerably both lower relative growth and mortality rates compared to the hermaphrodites in the primary forest over 10 years, consistent with a priori predictions. Hermaphrodites showed strong growth‐mortality trade‐offs across forest stages, even when possibly confounding factors had been accounted for. These results suggest that sexual system influences community succession and assembly by acting on the rates of growth and mortality, and the trade‐off between them. As vegetation develops, the demographic differences between breeding systems are much larger. Our results demonstrate the association between breeding system, succession, and community assembly and that this relationship is succession‐stage dependent. Our findings support the suggestion that the demographic advantage of dioecious species facilitates the coexistence of sexual systems in primary forest.
Adaptive phenotypic plasticity contributes to divergence between lake and river populations of an East African cichlid fish
Authors: Rajkov Jelena , Weber Alexandra Anh‐Thu , Salzburger Walter , Egger Bernd 
Published: June 2018

AbstractAdaptive phenotypic plasticity and fixed genotypic differences have long been considered opposing strategies in adaptation. More recently, these mechanisms have been proposed to act complementarily and under certain conditions jointly facilitate evolution, speciation, and even adaptive radiations. Here, we investigate the relative contributions of adaptive phenotypic plasticityvs. local adaptation to fitness, using an emerging model system to study early phases of adaptive divergence, the generalist cichlid fish speciesAstatotilapia burtoni. We tested direct fitness consequences of morphological divergence between lake and river populations in nature by performing two transplant experiments in Lake Tanganyika. In the first experiment, we used wild‐caught juvenile lake and river individuals, while in the second experiment, we used F1 crosses between lake and river fish bred in a common garden setup. By tracking the survival and growth of translocated individuals in enclosures in the lake over several weeks, we revealed local adaptation evidenced by faster growth of the wild‐caught resident population in the first experiment. On the other hand, we did not find difference in growth between different types of F1 crosses in the second experiment, suggesting a substantial contribution of adaptive phenotypic plasticity to increased immigrant fitness. Our findings highlight the value of formally comparing fitness of wild‐caught and common garden‐reared individuals and emphasize the necessity of considering adaptive phenotypic plasticity in the study of adaptive divergence.
Nest use dynamics of an undisturbed population of bald eagles
Authors: Wilson Tammy L. , Schmidt Joshua H. , Mangipane Buck A. , Kolstrom Rebecca , Bartz Krista K. 
Published: June 2018

AbstractManagement or conservation targets based on demographic rates should be evaluated within the context of expected population dynamics of the species of interest. Wild populations can experience stable, cyclical, or complex dynamics, therefore undisturbed populations can provide background needed to evaluate programmatic success. Many raptor species have recovered from large declines caused by environmental contaminants, making them strong candidates for ongoing efforts to understand population dynamics and ecosystem processes in response to human‐caused stressors. Dynamic multistate occupancy models are a useful tool for analyzing species dynamics because they leverage the autocorrelation inherent in long‐term monitoring datasets to obtain useful information about the dynamic properties of population or reproductive states. We analyzed a 23‐year bald eagle monitoring dataset in a dynamic multistate occupancy modeling framework to assess long‐term nest occupancy and reproduction in Lake Clark National Park and Preserve, Alaska. We also used a hierarchical generalized linear model to understand changes in nest productivity in relation to environmental factors. Nests were most likely to remain in the same nesting state between years. Most notably, successful nests were likely to remain in use (either occupied or successful) and had a very low probability of transitioning to an unoccupied state in the following year. There was no apparent trend in the proportion of nests used by eagles through time, and the probability that nests transitioned into or out of the successful state was not influenced by temperature or salmon availability. Productivity was constant over the course of the study, although warm April minimum temperatures were associated with increased chick production. Overall our results demonstrate the expected nesting dynamics of a healthy bald eagle population that is largely free of human disturbance and can be used as a baseline for the expected dynamics for recovering bald eagle populations in the contiguous 48 states.
Sediment chemistry of urban stormwater ponds and controls on denitrification
Authors: Blaszczak Joanna R. , Steele Meredith K. , Badgley Brian D. , Heffernan Jim B. , Hobbie Sarah E. , Morse Jennifer L. , Rivers Erin N. , Hall Sharon J. , Neill Christopher , Pataki Diane E. , Groffman Peter M. , Bernhardt Emily S. 
Published: June 2018

AbstractStormwater ponds and retention basins are ubiquitous features throughout urban landscapes. These ponds are potentially important control points for nitrogen (N) removal from surface water bodies via denitrification. However, there are possible trade‐offs to this water quality benefit if high N and contaminant concentrations in stormwater pond sediments decrease the complete reduction of nitrous oxide (N2O), a potent greenhouse gas, to dinitrogen (N2) during denitrification. This may occur through decreasing the abundance or efficiency of denitrifiers capable of producing the N2O reductase enzyme. We predicted that ponds draining increasingly urbanized landscapes would have higher N and metal concentrations in their sediments, and thereby greater N2O yields. We measured potential denitrification rates, N2O reductase (nosZ) gene frequencies, as well as sediment and porewater chemistry in 64 ponds distributed across eight U.S. cities. We found almost no correlation between the proportion of urban land cover surrounding ponds and the nutrient and contaminant concentrations in the stormwater pond sediments within or across all cities. Regression analysis revealed that the proportion of potential N2and N2O production that could be explained was under different environmental controls. Our survey raises many new questions about why N fluxes and transformations vary so widely both within and across urban environments, but also allays the concern that elevated metal concentrations in urban stormwater ponds will increase N2O emissions. Urban stormwater ponds are unlikely to be a problematic source of N2O to the atmosphere, no matter their denitrification potential.
HT‐NbOsB: Experimental and Theoretical Investigations of a Boride Structure Type Containing Boron Chains and Isolated Boron Atoms
Authors: Forsythe Ryland , Scheifers Jan P. , Zhang Yuemei , Fokwa Boniface P. T. 
Published: June 2018

AbstractInvited for the cover of this issue is the group of Boniface Fokwa from the University of California, Riverside, USA. The cover image shows two boron fragments found in the modifications of NbOsB: a finite B4 fragment (left) and the infinite B‐chain (right) as typically found in borides with a smaller metal‐to‐boron ratio.
Fabrication and characterization of implantable flushable electrodes for electric field‐mediated drug delivery in a brain tissue‐mimic agarose gel
Authors: Parupudi Tejasvi , Rahimi Rahim , Ammirati Mario , Sundararajan Raji , Garner Allen L. , Ziaie Babak 
Published: June 2018

AbstractEvery forty minutes, one person dies in the USA due to glioblastoma multiforme; a deadly form of brain cancer with an average five‐year survival rate less than 3%. The current standard of care for treatment involves surgical resection of the accessible tumor followed by radiation therapy and concomitant chemotherapy. Despite their potency, delivering chemotherapeutic agents to the brain is limited by the highly selective blood‐brain barrier, which prevents molecules >500 Da from reaching the brain. Other techniques, such as convection‐enhanced delivery, controlled release by drug‐loaded wafers or intracerebroventricular infusion have limited clinical utility due to unpredictable targeting and volume of drug distribution. We introduce a novel drug delivery technique that can use direct current electric fields to deliver charged chemotherapeutics to the site of brain parenchyma after tumor resection. We fabricate and characterize an implantable drug delivery system using flushable electrodes to deliver the charged chemotherapeutic or doxorubicin (+1) in a brain tissue‐mimic agarose gel (0.2% w/v) model by electrophoresis. The optimized capillary‐embedded electrode system exhibited a sustained movement of charged doxorubicin through nearly 3.5 mm in four hours, a distance for achieving effective intratumoral concentrations.
Enantioselective separation of twelve pairs of enantiomers on polysaccharide‐based chiral stationary phases and thermodynamic analysis of separation mechanism
Authors: Zhu Bolin , Yao Yaqi , Deng Miaoduo , Jiang Zhen , Li Qing 
Published: June 2018

AbstractThe enantioseparation of twelve pairs of structurally related 1‐aryl‐1‐indanone derivatives was studied in the normal‐phase mode using three different polysaccharide‐type chiral stationary phases, namely Chiralpak IB, Chiralpak IC, and Chiralpak ID. n‐Hexane/2‐propanol and n‐hexane/ethanol were employed as mobile phases. Among all the investigated chiral columns, Chiralpak IC exhibited the most universal and the best enantioseparation ability toward all the racemates, particularly with the mobile phase composed of n‐hexane/2‐propanol (90/10, v/v). Then the effects of column temperature on retention and enantioselectivity were examined in the range of 25–40°C. Satisfactory enantioseparation was obtained at ambient temperature. The natural logarithm of retention and separation factors (ln k and ln α) versus the reciprocal of absolute temperature (1/T) (Van't Hoff plots) were found to be linear for all racemates, indicating that the retention and separation mechanisms were independent of temperature in the range investigated. Then, the thermodynamic parameters (ΔΔH°, ΔΔS°, and ΔΔG°) were calculated from Van't Hoff plots. These values indicated that the solute transfer from the mobile to stationary phase was enthalpically favorable, and the process of enantioseparation was mainly enthalpy controlled. At last, the impact of small changes in molecular structures of the tested 1‐indanone derivatives on enantioseparation was also discussed.
Control‐oriented LPV Modeling for the Air Supply System of Proton Exchange Membrane Fuel Cells
Authors: Chen F. X. , Jiao J. R. , Liu S. G. , Yu Y. , Xu S. C. 
Published: June 2018

AbstractAir supply system, as a crucial subsystem of proton exchange membrane fuel cells (PEMFC), plays a very significant role in the efficiency and the reliability of the system. In order to better control the air supply subsystem, an appropriate model needs to be established to describe the subsystem covering whole working conditions from PEMFC startup to shutdown. This paper propose a linearized parameter varying (LPV) model based on system identification. To describe the subsystem in different working conditions, the subsystem is identified near 7 equilibrium points. Identification results show that the subsystem can be described as several linear models near equilibrium points. Based on these linear models, a LPV model is proposed solving 2‐D interpolation problem. It is proved theoretically that LPV system has the same steady‐state character and linear model at equilibrium points with identification models. The simulation and experiments results also verify that the LPV model can cover the working conditions from PEMFC startup to shutdown with accuracy both in dynamic condition and steady state.
Distinct neural substrates for visual short‐term memory of actions
Authors: Cai Ying , Urgolites Zhisen , Wood Justin , Chen Chuansheng , Li Siyao , Chen Antao , Xue Gui 
Published: June 2018

AbstractFundamental theories of human cognition have long posited that the short‐term maintenance of actions is supported by one of the “core knowledge” systems of human visual cognition, yet its neural substrates are still not well understood. In particular, it is unclear whether the visual short‐term memory (VSTM) of actions has distinct neural substrates or, as proposed by the spatio‐object architecture of VSTM, shares them with VSTM of objects and spatial locations. In two experiments, we tested these two competing hypotheses by directly contrasting the neural substrates for VSTM of actions with those for objects and locations. Our results showed that the bilateral middle temporal cortex (MT) was specifically involved in VSTM of actions because its activation and its functional connectivity with the frontal–parietal network (FPN) were only modulated by the memory load of actions, but not by that of objects/agents or locations. Moreover, the brain regions involved in the maintenance of spatial location information (i.e., superior parietal lobule, SPL) was also recruited during the maintenance of actions, consistent with the temporal–spatial nature of actions. Meanwhile, the frontoparietal network (FPN) was commonly involved in all types of VSTM and showed flexible functional connectivity with the domain‐specific regions, depending on the current working memory tasks. Together, our results provide clear evidence for a distinct neural system for maintaining actions in VSTM, which supports the core knowledge system theory and the domain‐specific and domain‐general architectures of VSTM.
Prognosis of subglottic carcinoma: Is it really worse?
Authors: Coskun Hakan , Mendenhall William M. , Rinaldo Alessandra , Rodrigo Juan P. , Suárez Carlos , Strojan Primož , López Fernando , Mondin Vanni , Saba Nabil F. , Shaha Ashok R. , Smee Robert , Takes Robert P. , Ferlito Alfio 
Published: June 2018

AbstractIt is traditionally accepted that subglottic carcinoma has a worse prognosis than tumors arising in other subsites of the larynx, owing to its tendency to present in advanced stages, with a high incidence of cartilage invasion and extralaryngeal spread. The incidence of subglottic carcinoma varies among series, mainly because there is no uniform definition of the upper boundary of the subglottis. The extent of the tumor may be difficult to define because subglottic carcinoma may spread through the submucosa without visible mucosal changes. There is also a rich lymphatic network in the subglottis draining to the prelaryngeal and paratracheal lymph nodes, which are usually not involved by cancers arising in other laryngeal subsites. Current literature data indicates that early‐stage subglottic carcinoma can be treated using radiotherapy or chemoradiotherapy with high locoregional control and survival rates. In advanced stage subglottic carcinoma, combination of surgery followed by radiotherapy or chemoradiotherapy resulted in comparable outcomes, as in advanced carcinomas from the rest of the larynx. Stage for stage, it is likely that the prognosis for subglottic carcinoma and of glottic and supraglottic cancers is similar.