bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloud‐Resolving Model Intercomparison of an MC3E Squall Line Case: Part II. Stratiform Precipitation Properties
Authors: Han Bin , Fan Jiwen , Varble Adam , Morrison Hugh , Williams Christopher R. , Chen Baojun , Dong Xiquan , Giangrande Scott E. , Khain Alexander , Mansell Edward , Milbrandt Jason A. , Shpund Jacob , Thompson Gregory
Published: January 2019

In this second part of a cloud microphysics scheme intercomparison study, we focus on biases and variabilities of stratiform precipitation properties for a midlatitude squall line event simulated with a cloud‐resolving model implemented with eight cloud microphysics schemes. Most of the microphysics schemes underestimate total stratiform precipitation, mainly due to underestimation of stratiform precipitation area. All schemes underestimate the frequency of moderate stratiform rain rates (2–6 mm/hr), which may result from low‐biased ice number and mass concentrations for 0.2–2‐mm diameter particles in the stratiform ice region. Most simulations overestimate ice water content (IWC) at altitudes above 7 km for temperatures colder than −20 °C but produce a decrease of IWC approaching the melting level, which is opposite to the trend shown by in situ observations. This leads to general underestimations of stratiform IWC below 5‐km altitude and rainwater content above 1‐km altitude for a given rain rate. Stratiform precipitation area positively correlates with the convective condensate detrainment flux but is modulated by hydrometeor type, size, and fall speed. Stratiform precipitation area also changes by up to 17%–25% through alterations of the lateral boundary condition forcing frequency. Stratiform precipitation, rain rate, and area across the simulations vary by a factor of 1.5. This large variability is primarily a result of variability in the stratiform downward ice mass flux, which is highly correlated with convective condensate horizontal detrainment strength. The variability of simulated local microphysical processes in the stratiform region plays a secondary role in explaining variability in simulated stratiform rainfall properties.
Estuarine Sediments Exhibit Dynamic and Variable Biogeochemical Responses to Hypoxia
Authors: Foster S. Q. , Fulweiler R. W.
Published: January 2019

Estuarine ecosystems are considered among the most valuable regions worldwide because of the wealth of ecosystem services they provide. Given their proximity to the land, they are also vulnerable to excessive nutrient inputs, which can lead to eutrophication and hypoxia. Water column hypoxia can dramatically alter sediment biogeochemistry, yet the response of specific processes varies widely. Predicting whether sediments are sources or sinks of ecologically and climatologically relevant nutrients and gases remains elusive, particularly for shallow coastal regions. In this study, we conducted experiments with sediments collected from Waquoit Bay (Massachusetts, United States) and measured dissolved nutrient and gas fluxes across the sediment‐water interface to investigate the impact of water column hypoxia (defined here as dissolved oxygen ≤3 mg/L) on three important ecosystem functions: nutrient regeneration, removal of reactive nitrogen, and the regulation of greenhouse gases. Under hypoxia we observed variable responses in sediment biogeochemical cycling, including little to no change in important nitrogen cycling processes such as ammonium efflux and nitrogen removal through denitrification. As expected, low oxygen conditions stimulated sediment phosphate efflux. This caused nutrient ratios for both nitrogen to phosphorus and silica to phosphorus in the overlying water to decrease by 50%. Such changes can alter both the composition of water column primary producers as well as the rate of primary production. Hypoxia led to an almost 60% decrease in sediment nitrous oxide consumption but had little impact on sediment methane emissions. Taken together, these experimental results suggest sediment biogeochemical cycling has variable and dynamic responses to hypoxia.
The Salinity Structure of the Amazon River Plume Drives Spatiotemporal Variation of Oceanic Primary Productivity
Authors: Gouveia N. A. , Gherardi D. F. M. , Wagner F. H. , Paes E. T. , Coles V. J. , Aragão L. E. O. C.
Published: January 2019

The Amazon river is a major source of terrestrially derived organic carbon to the tropical Atlantic Ocean. Field, satellite and a vertically generalized production model data were used to estimate empirical surface salinity and fit an inverse logit function to investigate the limiting effect of salinity on the productivity in the Amazon river plume. Satellite data included Moderate Resolution Imaging Spectroradiometer, Soil Moisture and Ocean Salinity, and Aquarius missions. Previous empirical surface salinity models have relied on a very narrow range of salinity values and satellite data to estimate the spatial extent of the river plume. The empirical surface salinity model presented here extended the range of salinity values and captures all the main surface mesoscale features, particularly those related to the main path of the low‐salinity water. We also show that it is possible to gain new insights on the spatiotemporal variability of the Amazon river plume by improving the empirical surface salinity and expanding its sampling period with the aid of remote sensing data. The variability of primary productivity is dominated by the subannual (6 month) and annual (12 month) frequency bands. Low‐salinity river water influences surface primary productivity continuously during the year through mechanisms associated with the western tropical Atlantic circulation and vertical mixing.
Differential Response of Greenhouse Gas Evasion to Storms in Forested and Wetland Streams
Authors: Aho K. S. , Raymond P. A.
Published: January 2019

Greenhouse gas evasion from inland waters is a globally significant yet highly uncertain flux, especially in regard to effects of wetlands and hydrologic variability. We sampled five first‐order and two second‐order streams with variable wetland influence during storm events for dissolved CO2, CH4, and N2O. We also calculated gas evasion rates. In first‐order streams, pCO2 and pN2O were significantly higher in the stream with the most wetland influence (mean ± 1 std: 3,965 ± 1,504 and 1.18 ± 0.37 μatm, respectively) than the forested stream (2,927 ± 439 and 0.47 ± 0.08 μatm, respectively). In second‐order streams, pCO2, pCH4, and pN2O were higher in the 14% wetland stream (3,274 ± 825, 501 ± 207, and 1.37 ± 0.43 μatm, respectively) than in the 2% wetland stream (1,858 ± 423, 137 ± 53, and 0.37 ± 0.08 μatm, respectively). In first‐order streams, pCO2 in streams with wetland influence increased during rain events, while pCO2 in streams with little to no wetland influence decreased or remained constant. Generally, pCH4 and pN2O followed the same trend, except in one stream with intermediate wetland influence. Gas transfer velocity increased in all streams during storm events. However, the forested streams had higher gas transfer velocities than the wetland streams due to steeper topography. CO2, CH4, and N2O evasion peaked in one of the intermediate wetland streams at high flow (maximum: 66 g C·m−2·day−1, 177 mg C·m−2·day−1, and 9.7 mg N·m−2·day−1, respectively). These findings suggest that gases are shunted downstream in flatter, wetland streams, while gases are evaded closer to their source in steeper, forested streams.
Definition of Seismic Input From Fault‐Based PSHA: Remarks After the 2016 Central Italy Earthquake Sequence
Authors: Valentini A. , Pace B. , Boncio P. , Visini F. , Pagliaroli A. , Pergalani F.
Published: January 2019

This work focuses on how the progress in earthquake science that follows a large, deeply studied earthquake might be promptly combined with updated approaches of seismic hazard analysis to guide applicative choices for seismic risk reduction, such as postevent seismic microzoning and building design. Both seismic microzoning and seismic design of structures require strong motion records to perform numerical site response analyses. These records have to be related to the seismotectonic context and historical seismicity of the investigation area. We first performed a fault‐based probabilistic seismic hazard analysis in the area struck by the 2016 central Italy seismic sequence to individuate reference uniform hazard spectra at rock conditions. We used two different seismic hazard models, one considering 27 individual seismogenic sources (ISSs), and the second one involving grid point seismicity, using a fixed‐radius smoothing approach. The geological and seismotectonic data of the 2016 seismic sequence were used to update the model of ISSs. We performed a deaggregation analysis to evaluate the contribution of the ISS in the hazard of four representative sites and to select the magnitude‐distance pairs useful in the selection of the real accelerograms. The deaggregation analysis has been performed to identify which source and magnitude most contribute to the hazard for each site, and for different periods of spectral accelerations. Finally, we select, for each site, a set of natural accelerograms, from both nonimpulsive and pulse‐like records, based on the magnitude‐distance pairs that are compatible on average with target uniform hazard spectra.
Probing 10 μK stability and residual drifts in the cross-polarized dual-mode stabilization of single-crystal ultrahigh-Q optical resonators
Authors: Lim Jinkang , Liang Wei , Savchenkov Anatoliy A. , Matsko Andrey B. , Maleki Lute , Wong Chee Wei
Published: January 2019

The thermal stability of monolithic optical microresonators is essential for many mesoscopic photonic applications such as ultrastable laser oscillators, photonic microwave clocks, and precision navigation and sensing. Their fundamental performance is largely bounded by thermal instability. Sensitive thermal monitoring can be achieved by utilizing cross-polarized dual-mode beat frequency metrology, determined by the polarization-dependent thermorefractivity of a single-crystal microresonator, wherein the heterodyne radio-frequency beat pins down the optical mode volume temperature for precision stabilization. Here, we investigate the correlation between the dual-mode beat frequency and the resonator temperature with time and the associated spectral noise of the dual-mode beat frequency in a single-crystal ultrahigh-Q MgF2 resonator to illustrate that dual-mode frequency metrology can potentially be utilized for resonator temperature stabilization reaching the fundamental thermal noise limit in a realistic system. We show a resonator long-term temperature stability of 8.53 μK after stabilization and unveil various sources that hinder the stability from reaching sub-μK in the current system, an important step towards compact precision navigation, sensing, and frequency reference architectures.
Nitric oxide production and antioxidant function during viral infection of the coccolithophore Emiliania huxleyi
Authors: Schieler Brittany M , Soni Megha V , Brown Christopher M , Coolen Marco J L , Fredricks Helen , Van Mooy Benjamin A S , Hirsh Donald J , Bidle Kay D
Published: January 2019

Emiliania huxleyi is a globally important marine phytoplankton that is routinely infected by viruses. Understanding the controls on the growth and demise of E. huxleyi blooms is essential for predicting the biogeochemical fate of their organic carbon and nutrients. In this study, we show that the production of nitric oxide (NO), a gaseous, membrane-permeable free radical, is a hallmark of early-stage lytic infection in E. huxleyi by Coccolithoviruses, both in culture and in natural populations in the North Atlantic. Enhanced NO production was detected both intra- and extra-cellularly in laboratory cultures, and treatment of cells with an NO scavenger significantly reduced viral production. Pre-treatment of exponentially growing E. huxleyi cultures with the NO donor S-nitroso-N-acetylpenicillamine (SNAP) prior to challenge with hydrogen peroxide (H2O2) led to greater cell survival, suggesting that NO may have a cellular antioxidant function. Indeed, cell lysates generated from cultures treated with SNAP and undergoing infection displayed enhanced ability to detoxify H2O2. Lastly, we show that fluorescent indicators of cellular ROS, NO, and death, in combination with classic DNA- and lipid-based biomarkers of infection, can function as real-time diagnostic tools to identify and contextualize viral infection in natural E. huxleyi blooms.
Histone H3 binding to the PHD1 domain of histone demethylase KDM5A enables active site remodeling
Authors: Longbotham James E. , Chio Cynthia M. , Dharmarajan Venkatasubramanian , Trnka Michael J. , Torres Idelisse Ortiz , Goswami Devrishi , Ruiz Karen , Burlingame Alma L. , Griffin Patrick R. , Fujimori Danica Galonić
Published: January 2019

Histone demethylase KDM5A removes methyl marks from lysine 4 of histone H3 and is often overexpressed in cancer. The in vitro demethylase activity of KDM5A is allosterically enhanced by binding of its product, unmodified H3 peptides, to its PHD1 reader domain. However, the molecular basis of this allosteric enhancement is unclear. Here we show that saturation of the PHD1 domain by the H3 N-terminal tail peptides stabilizes binding of the substrate to the catalytic domain and improves the catalytic efficiency of demethylation. When present in saturating concentrations, differently modified H3 N-terminal tail peptides have a similar effect on demethylation. However, they vary greatly in their affinity towards the PHD1 domain, suggesting that H3 modifications can tune KDM5A activity. Furthermore, hydrogen/deuterium exchange coupled with mass spectrometry (HDX-MS) experiments reveal conformational changes in the allosterically enhanced state. Our findings may enable future development of anti-cancer therapies targeting regions involved in allosteric regulation.
Phase Diagrams, Phase Separation Mechanisms and Morphologies in Liquid Crystalline Materials: Principles and Theoretical Foundations
Authors: Soule Ezequiel R. , Rey Alejandro D.
Published: January 2019

Polymer–liquid crystal composites are heterogeneous materials that display a rich phase behaviour and a variety of morphologies, and are typically used in electro-optical technological applications. This chapter presents a comprehensive general introduction to phase behaviour and morphologies of these materials. The fundamental physics underlying the formation of different morphologies is described, with a strong emphasis in how the trajectory in the phase diagram determines the phase separation mechanism and the emerging morphology. The effects of processing variables, chemical reaction and molecular structures on phase diagrams are rationalized through their effect on phase separation and diffusion. The theories, models and computations presented in this introductory chapter are a critical contribution to achieving desired functionalities by identifying the optimal processing conditions in these soft matter materials.
Photo-reactive Mesogens
Authors: Dierking Ingo
Published: January 2019

Different classes of photo-reactive, bifunctional mesogenic monomers are briefly summarized, and reviewed with respect to reactive groups, effects of spacer length, and the mesogenic part of the molecule. The chapter will provide a brief overview of materials that have been reported, and that are at least in part available commercially.
Introduction to Polymer Stabilized Liquid Crystals
Authors: Dierking Ingo
Published: January 2019

Polymer stabilized liquid crystals are introduced, by outlining the polymerization of photoreactive monomers to form phase separated polymer networks, templating the structures of the liquid crystal phases they were formed in. The latter is demonstrated for a range of different liquid crystal phases and director configurations. The electro-optic properties are then discussed in relation to the polymer morphology, which in turn is related to the polymerization conditions.
Polymer-stabilized Nematics and Their Applications
Authors: Morris Stephen M.
Published: January 2019

The addition of a polymer network to nematic liquid crystals (LC) was a notable milestone in the research and development of liquid crystalline materials. It was found that, not only did it improve the ruggedness and stability of the resulting films and devices, but it also increased the diversity in the electro-optic characteristics, and in some cases yielded important improvements in the resulting device performance. Polymer-stabilized nematics are composites that are typically obtained by doping a relatively small concentration by weight (typically <10wt%) of a polyfunctional monomer into the LC solvent. When cross-linked this leads to an interpenetrating polymer network that stabilizes, and to some degree phase separates from, the nematic host. These materials exhibit macroscopic physical and electro-optic properties that readily distinguish them from conventional side and main chain elastomers/polymers and polymer-dispersed LCs. In this Chapter, our objective is to consider the role that the polymer network plays on the resulting electro-optic characteristics of nematic LCs, primarily the threshold voltage and response times. Their behaviour will be compared with that observed in conventional, non-polymer-stabilized nematic devices. We also consider the experimental results obtained for different device architectures in which polymer-stabilization has been implemented and the advantages and disadvantages of introducing a polymer network for the electro-optic properties. The Chapter concludes with a brief overview of the role advanced fabrication techniques might play in the future development of polymer-stabilized nematic LCs and the use of polymer-stabilization to form tuneable microlenses.
Polymer-stabilized Antiferroelectric Liquid Crystals and Their Applications
Authors: Rudquist Per
Published: January 2019

An introduction to antiferroelectric phases and their properties is given, before describing in detail the effects of polymer stabilization on this phase, which is a contender to ferroelectric liquid crystals in displays and optical light shutters. The effects of polymer stabilization under various different applied electric field conditions, and the resulting electro-optic behavior is summarized and demonstrated, as are the effects on a variety of important material parameters. With respect to applications, the generation of grayscale responses from electric addressing field sequences is discussed.
Polymer-stabilized Blue Phase Liquid Crystal Displays
Authors: Li Y.
Published: January 2019

Blue Phase liquid crystal displays are based on phase range widening through polymer stabilization with special mixtures of reactive monomers, as well as the electro-optic Kerr effect. Such displays enable the development of a new generation of displays that do not require alignment layers. The current state of research in this field is discussed herein.
Polymer Dissolved Liquid Crystals
Authors: Dierking Ingo
Published: January 2019

Although most common, polymer modification of liquid crystals does not necessarily need to imply the formation of oriented networks from reactive monomers. Existing polymers can be simply dissolved within a liquid crystal. This affects largely the physical properties of the liquid crystal, and in particular its viscosity, and therefore also its response times. For ferroelectric liquid crystals the spontaneous polarization and the tilt angle are also affected. For frustrated phases the phase diagrams are largely changed. In this chapter an overview is provided of the different effects of polymer-liquid crystal mixtures on rheology, electro-optics and thermodynamics.
Stabilization of Discotic Liquid Crystals
Authors: Yuvaraj A. R. , Kumar Sandeep
Published: January 2019

It is surprising that only very little work has been done to polymer modify discotic liquid crystals. While polymer dispersed discotic liquid crystals have been reported, polymer-stabilized systems appear not to have been investigated at all. This may be due to the lack of a need for mechanical stabilization in opto-electronic devices, where other techniques can be employed, such as charge transfer complexation and complementary polytropic interactions. The currently used different methods of stabilization will be reviewed and compared, while polymer stabilization may open new prospects in the future.
A label-free, ultra-highly sensitive and multiplexed SERS nanoplasmonic biosensor for miRNA detection using a head-flocked gold nanopillar
Authors: Kim Woo Hyun , Lee Jong Uk , Song Sojin , Kim Soohyun , Choi Young Jae , Sim Sang Jun
Published: January 2019

The combination of head-flocked gold nanopillars and sandwich DNA probes is an advanced label-free, ultra-high sensitive, multiplexed nanoplasmonic detection system of circulating miRNAs for cancer diagnosis and prognosis.
A highly sensitive electrochemical aptasensor for detection of microcystin-LR based on a dual signal amplification strategy
Authors: Liu Xiaoqiang , Tang Yunfei , Liu Peipei , Yang Liwei , Li Lele , Zhang Qingyou , Zhou Yanmei , Khan Md. Zaved Hossain
Published: January 2019

In this work, a sensitive and selective electrochemical aptasensor for detection of microcystin-LR was developed based on a dual signal amplification system consisted of a novel ternary composite and horseradish peroxidase.
Single particle ICP-MS-based absolute and relative quantification ofE. coliO157 16S rRNA using sandwich hybridization capture
Authors: Xu Xiaomin , Chen Jiyun , Li Bangrui , Tang Lijuan , Jiang Jianhui
Published: January 2019

Herein, a novel 16S rRNA detection platform was achieved by combining a sandwich hybridization reaction, a single-molecule magnetic capture, and single particle-inductively coupled plasma mass spectrometry amplification.
Aptamer superstructure-based electrochemical biosensor for sensitive detection of ATP in rat brain with in vivo microdialysis
Authors: Jiang Yanan , Ma Wenjie , Ji Wenliang , Wei Huan , Mao Lanqun
Published: January 2019

An electrochemical biosensor with an aptamer superstructure as the recognition element is demonstrated for highly sensitive detection of ATP in the cerebral system.
A cascade amplification platform assisted with DNAzyme for activity analysis, kinetic study and effector screening of Fpg in vitro
Authors: Dang Wenya , Tong Chunyi , Yang Yupei , Liu Yongbei , Liu Bin , Zhou Hongyan , Wang Wei
Published: January 2019

As a highly conserved damage repair protein, Fpg can specifically recognize and digest 8-oxoG from a damaged DNA backbone.
Magnetic-capture-based SERS detection of multiple serum microRNA biomarkers for cancer diagnosis
Authors: Zhang Hao , Fu Chaopeng , Wu Shutao , Shen Youqing , Zhou Chunhui , Neng Jing , Yi Yu , Jin Yicheng , Zhu Yifeng
Published: January 2019

A highly sensitive and reproducible magnetic-capture SERS assay was developed for multiplexed detection of cancer-related microRNAs in serum solution.
Chemical and mechanistic analysis of photodynamic inhibition of Alzheimer's β-amyloid aggregation
Authors: Ahn Minkoo , Lee Byung Il , Chia Sean , Habchi Johnny , Kumita Janet R. , Vendruscolo Michele , Dobson Christopher M. , Park Chan Beum
Published: January 2019

Inhibition of Aβ42 aggregation by photoexcited thioflavin T that generates singlet oxygen to oxidize monomeric Aβ42.
Morphological and chemical tuning of lead halide perovskite mesocrystals as long-life anode materials in lithium-ion batteries
Authors: Wang Qun , Yang Tao , Wang Huanhuan , Zhang Jianlong , Guo Xinmin , Yang Zhen , Lu Songtao , Qin Wei
Published: January 2019

This is the first report stating that excellent cycling stability for 1000 cycles of MAPbBr3 anodes composed of small sized samples should be attributed to the small size, low defect concentration structure and good interface charge transfer.
A self-assembled nanotube supported by halogen bonding interactions
Authors: Kennedy Stuart R. , Main Mawgan U. , Pulham Colin R. , Ling Irene , Dalgarno Scott J.
Published: January 2019

Upper-rim halogenation of a calix[4]arene modulates the packing of self-assembled nanotubes through the formation of complementary halogen bonding interactions.
Synthesis and photocatalytic activity of δ-doped hexagonal NaYF4:Yb,Tm@TiO2/RGO nanocrystals
Authors: Zhang Huafang , Wang Tao , Yang Zhenxing , Liu Yuefeng , Zhao Jun , Li Quanjun , Mao Yanli
Published: January 2019

Improved photocatalytic activity of δ-doped β-NaYF4:Yb,Tm@TiO2/RGO nanocrystals.
Multicomponent crystals of nitrofurazone – when more is less
Authors: Sharara Kudzaishe N. , Nyamayaro Kudzanai , Wicht Merrill M. , Venter Gerhard A. , Báthori Nikoletta B.
Published: January 2019

Multicomponent crystal formation of nitrofurazone was challenging when the experimental work was based on popular crystal engineering principles.
Sensitivity analysis of the variability of amyloid aggregation profiles
Authors: Grigolato Fulvio , Arosio Paolo
Published: January 2019

The variability of amyloid aggregation profiles is linearly proportional to the duration of the aggregation process, and arises from a perturbation of one or more of the initial conditions.
Pronounced changes in atomistic mechanisms for the Cl− + CH3I SN2 reaction with increasing collision energy
Authors: Pratihar Subha , Nicola Barbosa Muniz Maria Carolina , Ma Xinyou , Borges Itamar , Hase William L.
Published: January 2019

A sudden change from indirect to direct mechanism for Cl− + CH3I at Erel of 0.27–0.28 eV in a relatively small collision energy range of 0.15–0.40 eV is revealed and many indirect mechanisms are identified.
Layer-dependent anisotropic frictional behavior in two-dimensional monolayer hybrid perovskite/ITO layered heterojunctions
Authors: Bi Sheng , Li Qikun , Yan Ying , Asare-Yeboah Kyeiwaa , Ma Tianbao , Tang Chaolong , Ouyang Zhongliang , He Zhengran , Liu Yun , Jiang Chengming
Published: January 2019

The anisotropy of friction between 2D perovskites and the ITO is a four-fold symmetry in misaligned and aligned contacts.
Structural organization and phase behaviour of meta-substituted dioctadecylaminobenzoquinones at the air/water interface
Authors: Behyan Shirin , Gritzalis Dimitrios , Schmidt Rolf , Kebede Eskedar , Cuccia Louis A. , DeWolf Christine
Published: January 2019

A Langmuir monolayer formed from a zwitterionic lipid analogue that exhibits a highly reversible transition to a three-dimensional multilayer structure driven by headgroup crystallization.
Achieving a direct band gap and high power conversion efficiency in an SbI3/BiI3 type-II vdW heterostructure via interlayer compression and electric field application
Authors: Lai Kang , Li Hongxing , Xu Yuan-Kai , Zhang Wei-Bing , Dai Jiayu
Published: January 2019

Interlayer compression and vertical electric field application improve the electronic and photovoltaic properties of type-II vdW heterostructures with an indirect gap.
A selective hydrolytic and restructuring approach through a Schiff base design on a coumarin platform for “turn-on” fluorogenic sensing of Zn2+
Authors: Pandey Abha , Asthana Sharad Kumar , Prakash Anand , Roy Jagat Kumar , Tiwari Ida , Upadhyay K. K.
Published: January 2019

The designed molecular probe, CMD, undergoes Zn2+ triggered restructuring and shows a fluorescence change in only 30 seconds. The LOD was found to be of sub-nanomolar level.
Efficient polycrystalline silicon solar cells with double metal oxide layers
Authors: Xu Yichen , Liu Jie , Cui Yonghua , Yin Rui , Wang Xishu , Wu Shengyao , Yu Xibin
Published: January 2019

Crystalline silicon solar cells can achieve high power conversion efficiency and can be successfully commercialized; however, the exploration of optimization strategies is still necessary.
Monitoring H-cluster assembly using a semi-synthetic HydF protein
Authors: Németh Brigitta , Esmieu Charlène , Redman Holly J. , Berggren Gustav
Published: January 2019

An artificial enzyme, incorporating an organometallic iron complex, is used to probe the activation mechanism of [FeFe] hydrogenase.
Hybrid organic–inorganic supramolecular systems based on a pyridine end-decorated molybdenum(ii) halide cluster and zinc(ii) porphyrinate
Authors: Volostnykh Marina V. , Mikhaylov Maxim A. , Sinelshchikova Anna A. , Kirakosyan Gayane A. , Martynov Alexander G. , Grigoriev Mikhail S. , Piryazev Dmitry A. , Tsivadze Aslan Yu. , Sokolov Maxim N. , Gorbunova Yulia G.
Published: January 2019

Herein, first examples of supramolecular coordination bonded hybrids of Mo(ii) cluster and zinc(ii) porphyrinates are reported.
Impact of traffic volumes on levels, patterns, and toxicity of polycyclic aromatic hydrocarbons in roadside soils
Authors: Kim Seong-Joon , Park Min-Kyu , Lee Sung-Eun , Go Hye-Jung , Cho Byung-Chae , Lee Yoon-Se , Choi Sung-Deuk
Published: January 2019

The concentrations of ∑16 PAHs and ∑7 carc PAHs in roadside soils were significantly correlated with traffic volumes.
MoS2-capped CuxS nanocrystals: a new heterostructured geometry of transition metal dichalcogenides for broadband optoelectronics
Authors: Li Yuan , Murthy Akshay A. , DiStefano Jennifer G. , Jung Hee Joon , Hao Shiqiang , Villa Cesar J. , Wolverton Chris , Chen Xinqi , Dravid Vinayak P.
Published: January 2019

Heterostructuring of different transition metal dichalcogenides (TMDs) leads to interesting band alignment and performance improvement, and thus enables new routes for the development of materials for next-generation semiconductor electronics.
2,5-Furandicarboxylic acid as a linker for lanthanide coordination polymers: the role of heteroaromatic π–π stacking and hydrogen bonding
Authors: Kumar Manesh , Sheikh Haq Nawaz , Fraconetti Antonio , Zaręba Jan K. , Sahoo Subash Chandra , Frontera Antonio
Published: January 2019

Heteroaromatic carboxylate ligands are very intriguing components of coordination assemblies such as coordination polymers (CPs) due to their inherently multitopic structures.
Preparation of high-yield and ultra-pure Au25 nanoclusters: towards their implementation in real-world applications
Authors: Galchenko Michael , Schuster Raphael , Black Andres , Riedner Maria , Klinke Christian
Published: January 2019

Colloidal approaches allow for the synthesis of Au nanoclusters (NCs) with atomic precision and sizes ranging from a few to hundreds of atoms.
3D PtAu nanoframe superstructure as a high-performance carbon-free electrocatalyst
Authors: Yoo Sungjae , Cho Sanghyun , Kim Dajeong , Ih Seongkeun , Lee Sungwoo , Zhang Liqiu , Li Hao , Lee Jin Yong , Liu Lichun , Park Sungho
Published: January 2019

The demonstrated strategy is useful for constructing high-performance catalytic superstructures using nanoframes as building blocks, leading to the carbon-free Pt nanoparticle catalysts.
An ultra-stretchable, highly sensitive and biocompatible capacitive strain sensor from an ionic nanocomposite for on-skin monitoring
Authors: Xu Haihua , Lv Ying , Qiu Dexing , Zhou Yongjin , Zeng Haoxuan , Chu Yican
Published: January 2019

An ultra-stretchable and highly-sensitive strain sensor was reported, which can monitor pulse, electrocardiograph, breath, finger motions and emotion changes.
Ultrasensitive, flexible, and low-cost nanoporous piezoresistive composites for tactile pressure sensing
Authors: Li Jing , Orrego Santiago , Pan Junjie , He Peisheng , Kang Sung Hoon
Published: January 2019

We report a facile sacrificial casting–etching method to synthesize nanoporous carbon nanotube/polymer composites for ultra-sensitive and low-cost piezoresistive pressure sensors.
Use of ArSO2SRf reagents: an efficient tool for the introduction of SRf moieties
Authors: Pannecoucke Xavier , Besset Tatiana
Published: January 2019

This review discusses the use of several ArSO2SRf reagents as SRf sources, an emerging trend to access SRf-containing molecules.
A one-pot metal-free protocol for the synthesis of chalcogenated furans from 1,4-enediones and thiols
Authors: Rajeshkumar Venkatachalam , Neelamegam Chinnaraj , Anandan Sambandam
Published: January 2019

Transition-metal-free synthesis of chalcogenated furans through the sequential thiol-Michael/Paal–Knorr reaction of 1,4-enediones in the presence of a catalytic amount of p-toluene sulfonic acid has been developed.
Synthesis of benzo[a]carbazoles via cyanide-catalyzed imino-Stetter reaction/Friedel–Crafts reaction sequence
Authors: Jeon Jiye , Cheon Cheol-Hong
Published: January 2019

A new sequential protocol for the synthesis of benzo[a]carbazoles was developed via the cyanide-catalyzed imino-Stetter reaction followed by Friedel–Crafts reaction.
Gold-catalyzed generation of azafulvenium from an enyne sulfonamide: rapid access to fully substituted pyrroles
Authors: Wu Feng , Chen Lianfen , Wang Yongdong , Zhu Shifa
Published: January 2019

A one-pot gold-catalyzed protocol for the synthesis of fully substituted pyrroles from enyne sulfonamides has been developed.
The influence of the stiffness of GelMA substrate on the outgrowth of PC12 cells
Authors: Wu Yibing , Xiang Yang , Fang Jiehua , Li Xiaokeng , Lin Zunwen , Dai Guangli , Yin Jun , Wei Peng , Zhang Deming
Published: January 2019

Recent studies have shown the importance of cell–substrate interaction on neurone outgrowth, where the Young’s modulus of the matrix plays a crucial role on the neurite length, migration, proliferation, and morphology of neurones. In the present study, PC12 cells were selected as the representative neurone to be cultured on hydrogel substrates with different stiffness to explore the effect of substrate stiffness on the neurone outgrowth. By adjusting the concentration of gelatin methacryloyl (GelMA), the hydrogel substrates with the variation of stiffnesses (indicated by Young’s modulus) from approximately 3–180 KPa were prepared. It is found that the stiffness of GelMA substrates influences neuronal outgrowth, including cell viability, adhesion, spreading, and average neurite length. Our results show a critical range of substrate’s Young’s modulus that support PC12 outgrowth, and modulate the cell characteristics and morphology. The present study provides an insight into the relationship between the stiffness of GelMA hydrogel substrates and PC12 cell outgrowth, and helps the design and optimization of tissue engineering scaffolds for nerve regeneration.
MicroRNAs and other non-coding RNAs in adipose tissue and obesity: emerging roles as biomarkers and therapeutic targets
Authors: Lorente-Cebrián Silvia , González-Muniesa Pedro , Milagro Fermín I. , Martínez J. Alfredo
Published: January 2019

Obesity is a metabolic condition usually accompanied by insulin resistance (IR), type 2 diabetes (T2D), and dyslipidaemia, which is characterised by excessive fat accumulation and related to white adipose tissue (WAT) dysfunction. Enlargement of WAT is associated with a transcriptional alteration of coding and non-coding RNAs (ncRNAs). For many years, big efforts have focused on understanding protein-coding RNAs and their involvement in the regulation of adipocyte physiology and subsequent role in obesity. However, diverse findings have suggested that a dysfunctional adipocyte phenotype in obesity might be also dependent on specific alterations in the expression pattern of ncRNAs, such as miRNAs. The aim of this review is to update current knowledge on the physiological roles of miRNAs and other ncRNAs in adipose tissue function and their potential impact on obesity. Therefore, we examined their regulatory role on specific WAT features: adipogenesis, adipokine secretion, inflammation, glucose metabolism, lipolysis, lipogenesis, hypoxia and WAT browning. MiRNAs can be released to body fluids and can be transported (free or inside microvesicles) to other organs, where they might trigger metabolic effects in distant tissues, thus opening new possibilities to a potential use of miRNAs as biomarkers for diagnosis, prognosis, and personalisation of obesity treatment. Understanding the role of miRNAs also opens the possibility of using these molecules on individualised dietary strategies for precision weight management. MiRNAs should be envisaged as a future therapeutic approach given that miRNA levels could be modulated by synthetic molecules (f.i. miRNA mimics and inhibitors) and/or specific nutrients or bioactive compounds.
The vermiform appendix: an immunological organ sustaining a microbiome inoculum
Authors: Vitetta Luis , Chen Jiezhong , Clarke Stephen
Published: January 2019

The hominoid vermiform appendix has been characterized as a diverticulum of the caecum and describes an entity at the juxtaposition of the colon in the confluence of tanias. The independent development of the lymphoid follicle centres of the appendix is progressed at birth in the presence of the intestinal commensal microbiome, an obligatory prompt for the diversification of intestinal and extra-intestinal mucosal immunological tissue. In the vermiform appendix, this activity is centred on further developing the inventory of primary antibodies and the maturation of T- and B-lymphocyte cells in the follicles within the lymphoid tissue. Furthermore, the columnar epithelia, enterocytes and goblet cells comprise the complement of cells that occupy the lamina propria and muscularis mucosae of the vermiform appendix’s mucosa, while macrophages and an abundance of immunoglobulin A and immunoglobulin G generating plasma cells seed the lamina propria. Intraepithelial immune cells consisting predominantly of specific CD8+ T regulatory lymphocytes occupy sites in the appendix analogous to those present in the intestinal epithelia of the caecal colon. The complement of bacterial genera concealed in the vermiform appendix is posited extant as a biofilm inoculum of the intestinal commensal microbiome. This facilitates re-inoculation of the proximal colon and to a lesser degree the terminal ilium post an intestinal perturbation such as occurs with daily lifestyle stressors, dietary choices and the short-term administration of antibiotics rather than an infectious fulminant colitis. A plausible appreciation results of the importance of multiple immunological aspects of a healthy vermiform appendix and the provision of a commensal biofilm to the gut that repairs a dysbiotic microbiome contributing to balancing intestinal pro- and anti-inflammatory activity for maintaining homeostasis in the gut. Since the composition of the gut microbiome can vary over the short-term and long-term, it is plausible that the appendix inoculum may be instrumental in maintaining the intestinal microbiome.
Greedy systems of linear inequalities and lexicographically optimal solutions
Authors: Fujishige Satoru
Published: January 2019

The present note reveals the role of the concept of greedy system of linear inequalities played in connection with lexicographically optimal solutions on convex polyhedra and discrete convexity. The lexicographically optimal solutions on convex polyhedra represented by a greedy system of linear inequalities can be obtained by a greedy procedure, a special form of which is the greedy algorithm of J. Edmonds for polymatroids. We also examine when the lexicographically optimal solutions become integral. By means of the Fourier–Motzkin elimination Murota and Tamura have recently shown the existence of integral points in a polyhedron arising as a subdifferential of an integer-valued, integrally convex function due to Favati and Tardella [Murota and Tamura, Integrality of subgradients and biconjugates of integrally convex functions. Preprint arXiv:1806.00992v1 (2018)], which can be explained by our present result. A characterization of integrally convex functions is also given.
On the preconditioned projective iterative methods for the linear complementarity problems
Authors: Edalatpanah Seyyed Ahmad
Published: January 2019

This paper aims to propose the new preconditioning approaches for solving linear complementarity problem (LCP). Some years ago, the preconditioned projected iterative methods were presented for the solution of the LCP, and the convergence of these methods has been analyzed. However, most of these methods are not correct, and this is because the complementarity condition of the preconditioned LCP is not always equivalent to that of the un-preconditioned original LCP. To overcome this shortcoming, we present a new strategy with a new preconditioner that ensures the solution of the same problem is correct. We also study the convergence properties of the new preconditioned iterative method for solving LCP. Finally, the new approach is illustrated with the help of a numerical example.
Notes on relative equilibria of isosceles molecules in classical approximation
Authors: McKinley Damaris , Paşca Daniel , Stoica Cristina
Published: January 2019

We study a classical model of isosceles triatomic “A-B-A” molecules. The atoms, considered mass points, interact mutually via a generic repulsive-attractive binary potential. First we show that the steady states, or relative equilibria (RE), corresponding to rotations about the molecule symmetry axis may be determined qualitatively assuming the knowledge of (1) the shape of the binary interaction potential, (2) the equilibrium diatomic distances (i.e., the equilibrium bond length) of the A-A and A-B molecules, and (3) the distance at which the RE of the diatomic A-A molecule ceases to exist. No analytic expression for the interaction potentials is needed. Second we determine the stability of the isosceles RE modulo rotations using geometric mechanics methods and using Lennard-Jones diatomic potentials. As a by-product, we verify the qualitative results on RE existence and bifurcation. For isosceles RE, we employ the Reduced Energy-Momentum method presented by Marsden [Lectures in Mechanics (Cambridge University Press, 1992)], whereas for linear (trivial isosceles) RE, we introduce the Symplectic Slice method, a technique based on the findings in the paper of Roberts et al. [J. Geom. Phys. 56, 762 (2006)].
Design and analysis of a burst strength device for testing vascular grafts
Authors: Pérez-Aranda C. , Gamboa F. , Castillo-Cruz O. , Cauich-Rodríguez J. V. , Avilés F.
Published: January 2019

The design and analysis of a device to measure the burst strength (strength under a state of pure radial internal pressure) and compliance of vascular grafts and flexible pressurized tubes is presented. The device comprises three main sections, viz., a clean air-dry pressure controller, a test specimen holder, and automated software for control and data collection. Air pressure is controlled by means of a valve and a dedicated mechanism allowing reaching up to 120 psi in increments of 1 psi, and recording pressure changes with 0.04 psi resolution. The circumferential strain is determined by measuring the radial displacement of the vascular graft using an optical arrangement capable of determining a maximum radial displacement of 10 mm with 0.02 mm resolution. The instrument provides a low uncertainty in compliance (±0.32%/100 mm Hg−1) and burst strength measurements. Due to its simplicity, the device can easily be reproduced in other laboratories contributing to a dedicated instrument with high resolution at low cost. The reliability of the apparatus is further confirmed by conducting finite element analysis, elasticity solutions for pressurized cylinders, and testing of small diameter vascular grafts made of a commercial aliphatic polyurethane tested under radial internal pressure.
Parameter estimation of linear frequency modulation signals based on sampling theorem and fractional broadening
Authors: Liu Xuelian , Han Jun , Wang Chunyang , Xiao Bo
Published: January 2019

Linear frequency modulation (LFM) signals are a class of important radar signals, but it is difficult to estimate their parameters in electronic warfare. Fractional Fourier transform (FRFT) is one of the most important methods for estimating the parameters of LFM signals, but the computational efficiency is strongly influenced by the search range and evaluation of the optimum FRFT order. To improve the estimation speed, we present a novel method for the parameter estimation of LFM signals using sampling theorem and fractional broadening. First, sampling theorem is used to calculate the search range of the optimum FRFT transform order. Then, the LFM signals are transformed by FRFT in the search range. Finally, the fractional broadening of the LFM signals is calculated, and the optimum FRFT order is obtained according to the relationship between the fractional broadening and the FRFT order. Experiments are performed to compare the proposed method and the traditional FRFT method. The results show that the proposed method is six times faster than the traditional FRFT method while preserving the accuracy. Moreover, it can quickly and accurately achieve the parameter estimation of multi-component LFM signals in the case of white Gaussian noise with a low signal-to-noise ratio.
An iterative optimization method for estimating accelerometer bias based on gravitational apparent motion with excitation of swinging motion
Authors: Zhang Tongwei , Huang Yongjiang , Li Haibing , Wang Songbing , Guo Xiaole , Liu Xixiang
Published: January 2019

Field calibration is an important method to guarantee the accuracy of a strapdown inertial navigation system. Zero velocity update based on the zero-velocity constraint when the carrier is without translational motion is a typical system-level calibration method. In zero velocity update, there is a coupling between biases and horizontal misalignment angles. The accuracy of horizontal misalignment angles is determined by the equivalent accelerometer biases in horizontal directions, which means that improving the accuracy of horizontal angles needs accurate calibration of accelerometer biases. Meanwhile, alignment with gravitational apparent motion is widely used taking advantages of its alignment ability in a swinging condition. But it is an analytical method and cannot calibrate sensor biases and is always dealt as a coarse alignment method. In order to calibrate accelerometer biases and utilize advantages of the alignment method with gravitational motion, a method to estimate accelerometer biases based on an iterative optimization method and gravitational apparent motion is presented in this paper. First, accelerometer biases are introduced to calculate apparent acceleration and an objective function is constructed. Then, Newton’s iteration is applied to iteratively optimize the parameters describing gravitational apparent motion and accelerometer biases. As revealed by the theoretical analysis and experimental results, different patterns of gravity and accelerometer biases will be generated when the carrier exhibits a swinging motion; thus, the convergence of the proposed algorithm will be ensured. After accelerometer biases are removed, initial alignment performed with the gravitational apparent motion reconstructed by the estimated parameters gives nearly zero horizontal misalignment angles.
Effects of pre-treatments and co-digestion on biogas production from Okra waste
Authors: Ugwu S. N. , Enweremadu C. C.
Published: January 2019

The effects of pre-treatment and co-digestion on the biogas yield of okra wastes are the focus of this paper. Okra wastes (O) were treated with 5% alkaline (NaOH) (OA), microwave (OMW), and microwave + alkaline. Sheep slurry (S) was co-digested with okra waste in varying proportions [25% (OS25), 50% (OS50), and 100% (S)]. Biomethane potential tests using 500 ml bioreactors were carried out in the batch mode at a hydraulic retention time of 25 days under mesophilic conditions (37 °C). The cumulative biogas yield from the alkaline treated sample (OA) increased by 45.87% when compared to the control (O), and other pre-treated samples were statistically the same with untreated okra waste at the 95% confidence level. Samples co-digested with sheep slurry recorded a low biogas yield. The results of the kinetic studies performed with the measured cumulative biogas yield showed that while the modified Gompertz model presented a better prediction range (0.66%–2.48%), the first-order kinetic model produced a better goodness of fit (<10) and R2 values when compared to the modified Gompertz model. The results of the Artificial neural network (ANN) performed were compared with the earlier used kinetic models, and it was observed that all the performance indicators (R2, RMSE and %prediction difference) from the ANN model best predicted the biomethane yields.