bluuebunny/crossref_metadata_2025_split huggingface dataset:
In situ 15N labeling experiment reveals different long‐term responses to ammonium and nitrate inputs in N‐saturated subtropical forest
Authors: Liu Wenjing , Yu Longfei , Zhang Ting , Kang Ronghua , Zhu Jing , Mulder Jan , Huang Yongmei , Duan Lei 
Published: August 2017

AbstractChronically elevated deposition of reactive nitrogen (N), as ammonium (NH4+) and nitrate (NO3−), in subtropical forests with monsoonal climate has caused widespread N leaching in southern China. So far, little is known about the effect of further increases in N input and changes in the relative proportion of NH4+ and NO3− on turnover rate and fate of atmogenic N. Here we report a 15N tracer experiment in Tieshanping (TSP) forest, SW China, conducted as part of a long‐term N fertilization experiment, using NH4NO3 and NaNO3, where effects of a doubling of monthly N inputs were compared. In June 2012, the regular N fertilizers were replaced by their 15N‐labeled forms, viz., 15NH4NO3 and Na15NO3, as a single‐dose addition. Mass balances of N for the initial 1.5 years following label addition showed that for both treatments, 70% to 80% of the annual N input was leached as NO3−, both at ambient and at double N input rates. This confirms the earlier reported extreme case of N saturation at TSP. The 15N, added as Na15NO3, showed recoveries of about 74% in soil leachates, indicating that NO3− input at TSP is subject to a rapid and nearly quantitative loss through direct leaching as a mobile anion. By contrast, recoveries of 15N in soil leachates of only 33% were found if added as 15NH4NO3. Much of the 15N was immobilized in the soil and to a lesser extent in the vegetation. Thus, immobilization of fresh N input is significantly greater if added as NH4+, than as NO3−.
Climate change imposes phenological trade‐offs on forest net primary productivity
Authors: Duveneck Matthew J. , Thompson Jonathan R. 
Published: August 2017

AbstractClimate warming is expected to lengthen growing seasons of temperate forest ecosystems and increase gross primary productivity. Simultaneously, warming is expected to increase summer ecosystem respiration, which could offset gains accrued from longer growing seasons. These responses have been observed during anomalously warm years, but the role of future climate change on phenological trade‐offs and how they affect net primary productivity (NPP) at regional scales in temperate forests remain unexplored. We simulated scenarios of climate change on monthly forest NPP throughout 18 million hectares of temperate forests in New England, USA, through year 2100. Using an ecophysiological model coupled to a forest landscape model, we simulated scenarios of climate change on monthly NPP. A high emission scenario (RCP 8.5), resulted in longer growing seasons that offset midsummer ecosystem respiration costs and produced greater annual NPP throughout the study landscape compared to simulations using the current climate. In spring and autumn months, temperature was positively associated with greater NPP; in summer months, the relationship was negative. Spatially, the greatest increase in NPP occurred in the warmer southern region under a warm climate scenario with increased precipitation. Under a warm scenario with drier conditions, the greatest increase in NPP occurred in the cooler northern region. Phenological trade‐offs will affect NPP of future forests and their potential to serve as a negative feedback to climate change. Barring other limitations, longer growing seasons will offset greater respiratory demands and contribute to increases in NPP throughout the temperate forests of New England in the future.
Photon Management through Virus‐Programmed Supramolecular Arrays
Authors: Veliz Frank A. , Ma Yingfang , Molugu Sudheer K. , Tiu Brylee David B. , Stewart Phoebe L. , French Roger H. , Steinmetz Nicole F. 
Published: August 2017

AbstractPhoton extraction and capture efficiency is a complex function of the material's composition, its molecular structure at the nanoscale, and the overall organization spanning multiple length scales. The architecture of the material defines the performance; nanostructured features within the materials enhance the energy efficiency. Photon capturing materials are largely produced through lithographic, top‐down, manufacturing schemes; however, there are limits to the smallest dimension achievable using this technology. To overcome these technological barriers, a bottom‐up nanomanufacturing is pursued. Inspired by the self‐programmed assembly of virus arrays in host cells resulting in iridescence of infected organisms, virus‐programmed, nanostructured arrays are studied to pave the way for new design principles in photon management and biology‐inspired materials science. Using the nanoparticles formed by plant viruses in combination with charged polymers (dendrimers), a bottom‐up approach is illustrated to prepare a family of broadband, low‐angular dependent antireflection mesoscale layered materials for potential application as photon management coatings. Measurement and theory demonstrate antireflectance and phototrapping properties of the virus‐programmed assembly. This opens up new bioengineering principles for the nanomanufacture of coatings and films for use in LED lighting and photovoltaics.
Cluster Recognition by Delaunay Triangulation of Synaptic Proteins in 3D
Authors: Boening Daniel , Gauthier‐Kemper Anne , Gmeiner Benjamin , Klingauf Jürgen 
Published: August 2017

AbstractThe advent of super‐resolution microscopy opens up the opportunity to study biological structures in unprecedented detail. However, revealing quantitative information about the spatial organization of a set of labeled proteins requires sophisticated analysis. This study introduces a novel robust cluster recognition algorithm based on Delaunay triangulation (CRADT), which can handle complex datasets generated by 3D super‐resolution microscopy. This algorithm allows determining volume and shape of protein clusters in 3D. The study demonstrates its performance by applying this algorithm on dual‐color 3D super‐resolved measurements of mouse hippocampal synapses, stained against the presynaptic active zone marker protein Bassoon and the opposing postsynaptic density protein Homer as well as the exo‐ and endocytosis machinery proteins Synaptobrevin and Clathrin.
A Novel Solution‐Processable n‐Dopant Based on 1,4‐Dihydropyridine Motif for High Electrical Conductivity of Organic Semiconductors
Authors: Shi Ke , Lu Zuo‐Yu , Yu Zi‐Di , Liu Han‐Yu , Zou Ye , Yang Chi‐Yuan , Dai Ya‐Zhong , Lu Yang , Wang Jie‐Yu , Pei Jian 
Published: August 2017

Abstractp‐ or n‐Dopants have played significant roles in the improvement of organic electronic devices through the controllable doping of organic semiconductors. However, there has been little study of air‐stable n‐dopants under ambient conditions with strong doping capability due to the low electron affinities of organic semiconductors. Herein, a 1,4‐dihydropyridine‐based derivative is designed and facilely synthesized as an efficient n‐dopant. The doping process is systematically investigated by UV–vis–NIR spectroscopy in solution and ultraviolet photoelectron spectroscopy in the solid state. Excellent conductivities are obtained for a variety of doped n‐type semiconductors via a simple solution process without further treatment, suggesting a broad class of 1,4‐dihydropyridine derivatives could be used as n‐dopants in future organic electronic devices.
Enzymatic C−H Oxidation–Amidation Cascade in the Production of Natural and Unnatural Thiotetronate Antibiotics with Potentiated Bioactivity
Authors: Li Jie , Tang Xiaoyu , Awakawa Takayoshi , Moore Bradley S. 
Published: August 2017

AbstractThe selective activation of unreactive hydrocarbons by biosynthetic enzymes has inspired new synthetic methods in C−H bond activation. Herein, we report the unprecedented two‐step biosynthetic conversion of thiotetromycin to thiotetroamide C involving the tandem oxidation and amidation of an unreactive ethyl group. We detail the genetic and biochemical basis for the terminal amidation in thiotetroamide C biosynthesis, which involves a uniquely adapted cytochrome P450–amidotransferase enzyme pair and highlights the first oxidation–amidation enzymatic cascade reaction leading to the selective formation of a primary amide group from a chemically inert alkyl group. Motivated by the ten‐fold increase in antibiotic potency of thiotetroamide C ascribed to the acetamide group and the unusual enzymology involved, we enzymatically interrogated diverse thiolactomycin analogues and prepared an unnatural thiotetroamide C analogue with potentiated bioactivity compared to the parent molecule.
The Hydrophobic Gap at High Hydrostatic Pressures
Authors: Wirkert Florian J. , Hölzl Christoph , Paulus Michael , Salmen Paul , Tolan Metin , Horinek Dominik , Nase Julia 
Published: August 2017

AbstractWe have gained new insight into the so‐called hydrophobic gap, a molecularly thin region of decreased electron density at the interface between water and a solid hydrophobic surface, by X‐ray reflectivity experiments and molecular dynamics simulations at different hydrostatic pressures. Pressure variations show that the hydrophobic gap persists up to a pressure of 5 kbar. The electron depletion in the interfacial region strongly decreases with an increase in pressure, indicating that the interfacial region is compressed more strongly than bulk water. The decrease is most significant up to 2 kbar; beyond that, the pressure response of the depletion is less pronounced.
Molecular Dynamics of Hexamethylbenzene at Low Temperatures: Evidence of Unconventional Magnetism Based on Rotational Motion of Protons
Authors: Yen Fei , Zhao Zhenzheng , Hu Sixia , Chen Lang 
Published: August 2017

AbstractThe types of magnetism known to date are all mainly based on contributions from electron motion. We show how rotational motion of protons (H+) within the methyl groups in hexamethylbenzene (C6(CH3)6) also contribute significantly to the magnetic susceptibility. Starting from below 118 K, as the rotational motion of the methyl groups set in, an associated magnetic moment positive in nature due to charge of the protons renders the susceptibility to become anomalously dependent on temperature. Starting from 20 K, the susceptibility diverges with decreasing temperature indicative of spin–spin interactions between methyl groups aligned in a previously unclassified type of anti‐ferromagnetic configuration. Complementary dielectric constant measurements also show the existence of magneto‐dielectric coupling. Our findings allow for the study of strongly correlated systems that are based on a species that possesses much slower dynamics.
In Situ Investigation of Methane Dry Reforming on Metal/Ceria(111) Surfaces: Metal–Support Interactions and C−H Bond Activation at Low Temperature
Authors: Liu Zongyuan , Lustemberg Pablo , Gutiérrez Ramón A. , Carey John J. , Palomino Robert M. , Vorokhta Mykhailo , Grinter David C. , Ramírez Pedro J. , Matolín Vladimír , Nolan Michael , Ganduglia‐Pirovano M. Verónica , Senanayake Sanjaya D. , Rodriguez José A. 
Published: August 2017

AbstractStudies with a series of metal/ceria(111) (metal=Co, Ni, Cu; ceria=CeO2) surfaces indicate that metal–oxide interactions can play a very important role for the activation of methane and its reforming with CO2 at relatively low temperatures (600–700 K). Among the systems examined, Co/CeO2(111) exhibits the best performance and Cu/CeO2(111) has negligible activity. Experiments using ambient pressure X‐ray photoelectron spectroscopy indicate that methane dissociates on Co/CeO2(111) at temperatures as low as 300 K—generating CHx and COx species on the catalyst surface. The results of density functional calculations show a reduction in the methane activation barrier from 1.07 eV on Co(0001) to 0.87 eV on Co2+/CeO2(111), and to only 0.05 eV on Co0/CeO2−x(111). At 700 K, under methane dry reforming conditions, CO2 dissociates on the oxide surface and a catalytic cycle is established without coke deposition. A significant part of the CHx formed on the Co0/CeO2−x(111) catalyst recombines to yield ethane or ethylene.
Metallofullerenol Inhibits Cellular Iron Uptake by Inducing Transferrin Tetramerization
Authors: Li Jinxia , Xing Xueqing , Sun Baoyun , Zhao Yuliang , Wu Zhonghua 
Published: August 2017

AbstractHerein, A549 tumor cell proliferation was confirmed to be positively dependent on the concentration of Fe3+ or transferrin (Tf). Gd@C82(OH)22 or C60(OH)22 effectively inhibited the iron uptake and the subsequent proliferation of A549 cells. The conformational changes of Tf mixed with FeCl3, GdCl3, C60(OH)22 or Gd@C82(OH)22 were obtained by SAXS. The results demonstrate that Tf homodimers can be decomposed into monomers in the presence of FeCl3, GdCl3 or C60(OH)22, but associated into tetramers in the presence of Gd@C82(OH)22. The larger change of SAXS shapes between Tf+C60(OH)22 and Tf+FeCl3 implies that C60(OH)22 is bound to Tf, blocking the iron‐binding site. The larger deviation of the SAXS shape from a possible crystal structure of Tf tetramer implies that Gd@C82(OH)22 is bound to the Tf tetramer, thus disturbing iron transport. This study well explains the inhibition mechanism of Gd@C82(OH)22 and C60(OH)22 on the iron uptake and the proliferation of A549 tumor cells and highlights the specific interactions of a nanomedicine with the target biomolecules in cancer therapy.
Boundary Stabilization of a Cosserat Elastic Body
Authors: Najafi Ali , Alasty Aria , Vatankhah Ramin , Eghtesad Mohammad , Daneshmand Farhang 
Published: August 2017

AbstractBoundary stabilization of vibrating three‐dimensional Cosserat elastic solids are studied using mathematical tools, such as operator theory and semigroup techniques. The advantages of the boundary control laws for both boundary stabilization problems are investigated. The boundary stabilization problems are studied using a Lyapunov stability method and LaSalle's invariant set theorem. Numerical simulations are provided to illustrate the effectiveness and performance of the designed control scheme.
Adaptive Fractional Order PI Controller Design for a Flexible Swing arm System Via Enhanced Virtual Reference Feedback Tuning
Authors: Xie Yuanlong , Tang Xiaoqi , Zheng Shiqi , Qiao Wenjun , Song Bao 
Published: August 2017

AbstractFlexible swing arm system (FSAS) is one of the most important components in the LED packaging industry. The trajectory tracking performance of the FSAS will directly affect the efficiency and accuracy of the LED packaging equipment. In order to meet the high precision and high speed requirements, this paper proposes an adaptive fractional order proportional integral (AFOPI) control method based on enhanced virtual reference feedback tuning (EVRFT). In this method, the AFOPI controller is applied to handle the fractional order characteristics of the FSAS. EVRFT is used to tune the AFOPI controller in a real‐time way to accommodate the time‐varying operating conditions. The proposed method is facilitated with two advantages: 1) only input/output measured data are fully utilized during the recursive tuning process without using model information of the controlled FSAS; 2) an improved adaptive law is incorporated in EVRFT to reduce the computation burden and provide an unbiased estimate for the ideal controller simultaneously. Thus, the conventional VRFT is enhanced both in efficiency and accuracy. The stability of the proposed method is guaranteed by rigorous theoretical analysis. Finally, experimental results are presented to verify the effectiveness of the EVRFT‐based AFOPI controller.
Investigating facial phenotype in autism spectrum conditions: The importance of a hypothesis driven approach
Authors: Boutrus Maryam , Maybery Murray T. , Alvares Gail A. , Tan Diana Weiting , Varcin Kandice J. , Whitehouse Andrew J. O. 
Published: August 2017

Atypical facial characteristics have been observed in many disorders associated with developmental disability. While autism spectrum conditions (ASC) have not previously been thought to be associated with a distinct facial phenotype, an emerging research literature is casting doubt on this assumption. The identification of differences in the facial phenotype of individuals with ASC may contribute to efforts to promote early identification of the condition and help elucidate etiological pathways. With the aim of identifying facial phenotypes associated with ASC, this commentary evaluated facial features purported to distinguish ASC from typical development. Although there is little consensus across the reviewed studies for the majority of facial characteristics described, preliminary evidence suggests increased facial asymmetry may be more common in ASC. There is also evidence to suggest that there are morphologically distinct subgroups within ASC that correspond with different cognitive and behavioral symptomatology. However, in light of the various inconsistencies in the reported literature, and based on an accumulating understanding of etiological pathways proposed to be associated with ASC, we propose an alternative paradigm for investigating facial phenotypes in ASC. A series of studies are outlined to demonstrate the promise of a research program that has taken a hypothesis‐driven approach to examine facial phenotypes associated with increased exposure to prenatal testosterone and to ASC. Autism Res 2017, 10: 1910–1918. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.Lay SummaryThis commentary reviewed studies that found differences in the facial features of individuals with autism spectrum conditions (ASC) compared to typically developing individuals. While there is little agreement between studies, there is some support for asymmetrical facial features associated with ASC, and preliminary evidence that particular facial features relate to specific patterns of cognitive and behavioral symptoms. However, in light of inconsistencies between studies and based on accumulating understanding of etiological pathways, we propose an alternative approach to investigating facial differences in ASC.
Neuroprotective effects of honokiol: from chemistry to medicine
Authors: Talarek Sylwia , Listos Joanna , Barreca Davide , Tellone Ester , Sureda Antoni , Nabavi Seyed Fazel , Braidy Nady , Nabavi Seyed Mohammad 
Published: August 2017

AbstractThe incidence of neurological disorders is growing in developed countries together with increased lifespan. Nowadays, there are still no effective treatments for neurodegenerative pathologies, which make necessary to search for new therapeutic agents. Natural products, most of them used in traditional medicine, are considered promising alternatives for the treatment of neurodegenerative diseases. Honokiol is a natural bioactive phenylpropanoid compound, belonging to the class of neolignan, found in notable amounts in the bark of Magnolia tree, and has been reported to exert diverse pharmacological properties including neuroprotective activities. Honokiol can permeate the blood brain barrier and the blood‐cerebrospinal fluid to increase its bioavailability in neurological tissues. Diverse studies have provided evidence on the neuroprotective effect of honokiol in the central nervous system, due to its potent antioxidant activity, and amelioration of the excitotoxicity mainly related to the blockade of glutamate receptors and reduction in neuroinflammation. In addition, recent studies suggest that honokiol can attenuate neurotoxicity exerted by abnormally aggregated Aβ in Alzheimer's disease. The present work summarizes what is currently known concerning the neuroprotective effects of honokiol and its potential molecular mechanisms of action, which make it considered as a promising agent in the treatment and management of neurodegenerative diseases. © 2017 BioFactors, 43(6):760–769, 2017
Blocking the ERK1/2 signal pathway can inhibit S100A12 induced human aortic smooth muscle cells damage
Authors: Jiang Wanli , Wang Zhiwei , Hu Zhipeng , Wu Hongbing , Hu Rui , Hu Xiaoping , Ren Zongli , Huang Jizhen 
Published: August 2017

AbstractIncreased levels of S100A12 and activated matrix metalloproteinase 2/9 (MMP‐2/9) produced by human aortic smooth muscle cells (HASMCs) have recently implicated in the development of thoracic aortic disease. In the present study, we investigated the effect of S100A12 on HASMCs and identified the intracellular signal pathways involved by Western blot. The results were shown that up‐expression of S100A12 in HASMCs induced cell apoptosis and inhibited cell proliferation. Additionally, S100A12 significantly increased the expression of MMP‐2, MMP‐9, and VCAM‐1 in HASMCs at translational levels. Furthermore, our results also showed that S100A12 induced HASMCs damage by increased related proteins expression was mediated by the activation of ERK1/2 signal pathway, whereas p38 MAPK had no effect on those processes. Blocked the activation of ERK1/2 could decrease S100A12 induced the apoptosis and inhibited cell proliferation of HASMCs. In conclusion, these results indicated that S100A12 could increase the expression of MMP‐2, MMP‐9, and vascular cell adhesion molecule 1 (VCAM‐1) in HASMCs via activation of ERK1/2 signal pathway, which leads to injury of HASMCs. Therefore, antagonists of ERK1/2 may be useful for treating thoracic aortic dissection.
Erythromelanosis follicularis faciei et colli with reticulated hyperpigmentation of the extremities
Authors: Al‐Saif Fahad Mohammad , Baqays Abdullah Ali , AlSaif Hadeel Fahad , Alhumidi Ahmed Abdullah 
Published: August 2017

Key Clinical MessageErythromelanosis follicularis faciei et colli (EFFC) is a distinct, rare, and underdiagnosed condition of unknown etiology that is characterized by well‐demarcated erythema, hyperpigmentation, and follicular papules. The pigmentation is usually on both maxillary, preauricular regions, and the cheeks. We report a case of a 12‐year‐old boy with EFFC that was associated with reticulated pigmentation of the extremities.
Continuous Hydrogenation of L‐Arabinose and D‐Galactose in a Mini Packed‐Bed Reactor
Authors: Müller Anne , Hilpmann Gerd , Haase Stefan , Lange Rüdiger 
Published: August 2017

AbstractThe continuous hydrogenation of a mixture of L‐arabinose and D‐galactose over a Ru/C catalyst was investigated in a miniaturized packed‐bed reactor. The reaction is one important step of the transformation of the naturally occurring hemicellulose arabinogalactan into valuable sugar alcohols. Process intensification was accomplished by reducing the reactor dimensions to a few millimeters; thus leading to better mass and heat transfer performance. The effects of temperature, pressure, and liquid flow rate on the yield and by‐product formation are discussed. Based on a kinetic model derived from batch experiments, a model of the continuous reactor was developed and used for scale‐up purposes.
Thermochemical Biomass Conversion for Decentralized Power Generation with the Inverse Brayton Cycle
Authors: Pfeil Marcel , Konradi Simon T. , Pohl Sven 
Published: August 2017

AbstractBiomass is an important energy source for decentralized power generation. The combination of a two‐stage thermochemical conversion unit with an inverse Brayton cycle (IBC) is the subject of current research activities. Several advantages are expected compared to commercially available concepts. A commercially proven turbocharger from the automotive industry is used for the IBC unit. No cost‐intensive gas cleaning is required due to an almost dust‐ and tar‐free biomass conversion. The influence of the feedstock characteristics on the thermochemical conversion, the emissions, and the overall plant performance is subject to process optimization studies. Furthermore, validation of the concept is the target of a demonstration phase planned for a later stage of the research activities.