bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical Sources of High‐Frequency Seismic Noise on Cascadia Initiative Ocean Bottom Seismometers
Authors: Hilmo Rose , Wilcock William S. D.
Published: September 2020

Physical sources of high‐frequency seismic noise in the ocean are investigated using data from the Cascadia Initiative (CI) ocean bottom seismometer (OBS) network, hindcasts of wind speed, waves, and the bottom currents predicted by a regional ocean circulation model and observed at sites on cabled observatories. Seismic data in the 5–12 Hz band are considered because it is best for detecting regional earthquakes and lies between the frequencies of local microseisms and the seasonal whale calls. Median noise levels in this range vary by ~20 dB between sites at a given depth but on average decrease with increasing depth. On the continental shelf, the orbital motions of ocean waves are a major source of noise while at the quietest sites in the deep ocean, noise increases when wind speeds exceed ~10 m/s. On the continental slope and abyssal plain within about 100 km of the slope, seismic noise is not predicted at specific sites by the bottom currents in the ocean circulation model. In these regions, ocean currents are inferred to be the primary source of noise, because noise varies on tidal periods, is low on buried seismometers, and has spatial variations broadly consistent with those of median absolute currents. Comparisons between OBSs suggest that high‐frequency noise is reduced by low‐profile hydrodynamic designs but not by shielding. Many OBSs also record numerous short duration events on and near the continental shelf that have been attributed elsewhere to animals bumping into the sensor or gas bubbles moving through sediments.
Dynamics of Southern Hemisphere Atmospheric Circulation Response to Anthropogenic Aerosol Forcing
Authors: Wang Hai , Xie Shang‐Ping , Zheng Xiao‐Tong , Kosaka Yu , Xu Yangyang , Geng Yu‐Fan
Published: September 2020

Anthropogenic aerosols, concentrated largely in the Northern Hemisphere, not only affect the local climate but also induce pronounced changes in atmospheric circulation that extend into the Southern Hemisphere (SH). In coupled historical single‐forcing simulations, aerosol forcing induces a deceleration of both the subpolar jet (SPJ) and the subtropical jet (STJ) in SH in austral winter. Atmospheric general circulation model experiments indicate that the STJ is weakened by an interhemisphere gradient in the zonal mean sea surface temperature (SST) and an anomalous cross‐equatorial Hadley circulation, while the SPJ response shares similar feedbacks with the greenhouse gas forcing. Specifically, atmospheric eddy adjustments are important for the SPJ change. The atmospheric response unique to anthropogenic aerosol forcing (e.g., cross‐equatorial Hadley cell and the weakened SH STJ) can be exploited for climate change attribution.
Provenance Evolution of Age‐Calibrated Strata Reveals When and How South China Block Collided With Gondwana
Authors: Yang Chuan , Li Xian‐Hua , Li Zheng‐Xiang , Zhu Maoyan , Lu Kai
Published: September 2020

The South China Block (SCB) has been regarded by many as an integral part of Gondwana, but proposed timing and processes for its accretion to Gondwana vary and remain contentious, largely owing to the lack of reliable Pan‐African age paleomagnetic data and tectono‐magmatic records from the SCB. Integrated in situ U‐Pb ages and Hf‐O isotope analyses of detrital zircons from geochronologically well‐calibrated Ediacaran‐Cambrian sedimentary rocks of western SCB reveal age populations of 2.51, 1.85, 1.20, 0.80, and 0.52 Ga. Detrital zircon age spectra indicate a major tectonic transition for the SCB during 0.56–0.54 Ga, interpreted to reflect the beginning of the collision between SCB‐Indochina and NW India blocks. The collisional event lasted until early Ordovician, leading to the suturing of the SCB‐Indochina to the northern margin of East Gondwana.
Evaluation of the Cross‐Field Current Instability as a Substorm Onset Process With Auroral Bead Properties
Authors: Lui A. T. Y.
Published: September 2020

Detailed properties of the spatially periodic auroral beads (ABs) that develop immediately prior to auroral substorm expansion onset on breakup auroral arcs pose stringent observational constraints on the substorm onset process. Theoretical predictions of the cross‐field current instability (CCI) are evaluated in terms of these constraints. It is found that CCI satisfies these constraints associated with ABs, that is, their growth rates, wavelengths, and periods, by matching these characteristics well with the theoretical predictions of CCI. Several subtle trends in AB properties are revealed with CCI solutions applied to them. For a given observed wavelength in the ionosphere, waves with longer periods are generated at onset sites at longer downstream distances for both westward and eastward drifting ABs. Waves with higher growth rates are generated by higher drift speeds for a given observed period and for a given observed wavelength by onset sites at closer downstream distances. A distinct group of eastward drifting ABs having long periods and small wavelengths are related to onset sites with relatively high drift speeds and large downstream distances. These revelations indicate that the onset site can occur over a range of downstream distances. ABs possessing two different propagating directions may be accommodated. A two‐dimensional equilibrium current sheet can be constructed from the adopted parameters for the current sheet used in CCI solution. Some misunderstandings of CCI are clarified as well. All these findings provide strong evidence for CCI as a viable substorm onset process.
20 Years of ACE Data: How Superposed Epoch Analyses Reveal Generic Features in Interplanetary CME Profiles
Authors: Regnault F. , Janvier M. , Démoulin P. , Auchère F. , Strugarek A. , Dasso S. , Noûs C.
Published: September 2020

Interplanetary coronal mass ejections (ICMEs) are magnetic structures propagating from the Sun's corona to the interplanetary medium. With over 20 years of observations at the L1 libration point, ACE offers hundreds of ICMEs detected at different times during several solar cycles and with different features such as the propagation speed. We investigate a revisited catalog of more than 400 ICMEs using the superposed epoch method on the mean, median, and the most probable values of the distribution of magnetic and plasma parameters. We also investigate the effects of the speed of ICMEs relative to the solar wind, the solar cycle, and the existence of a magnetic cloud on the generic ICME profile. We find that fast‐propagating ICMEs (relatively to the solar wind in front) still show signs of compression at 1 au, as seen by the compressed sheath and the asymmetric profile of the magnetic field. While the solar cycle evolution does not impact the generic features of ICMEs, there are more extreme events during the active part of the cycle, widening the distributions of all parameters. Finally, we find that ICMEs with or without a detected magnetic cloud show similar profiles, which confirms the hypothesis that ICMEs with no detected magnetic clouds are crossed further away from the flux rope core. Such a study provides a generic understanding of processes that shape the overall features of ICMEs in the solar wind and can be extended with future missions at different locations in the solar system.
Influence of the Solar Wind Dynamic Pressure on the Ion Precipitation: MAVEN Observations and Simulation Results
Authors: Martinez A. , Modolo R. , Leblanc F. , Chaufray J. Y. , Witasse O. , Romanelli N. , Dong Y. , Hara T. , Halekas J. , Lillis R. , McFadden J. , Eparvier F. , Leclercq L. , Luhmann J. , Curry S. , Jakosky B.
Published: September 2020

We discuss the influence of the solar wind dynamic pressure on the ion precipitation using observations performed by MAVEN from 4 June 2014 to 20 July 2017. The increase of the dynamic pressure from 0.63 to 1.44 nPa is clearly associated with an increase of the same order of magnitude of the precipitating oxygen ion energy flux measured by MAVEN/STATIC from 9.9 to 20.6 × 106 eV · cm−2 · sr−1 · s−1 at low energy (from 30 to 650 eV). In the same way, from 650 to 25,000 eV, MAVEN/SWIA (all species) observed an increase from 22.4 to 42.8 × 107eV · cm−2 · sr−1 · s−1 of the precipitating ion energy flux. Performing two simulations using the average solar wind conditions for both solar dynamic pressure regimes observed by MAVEN as input of the LatHyS model (LATMOS Hybrid Simulation), we reproduce some of the key characteristics of the observed oxygen ion precipitation. We characterize the oxygen ions simulated by LatHyS by their energy and time of impact, their time of injection in the simulation and initial position, and the mechanism by which these ions were created. The model suggests that the main cause of the increase of the heavy ion precipitation during an increase of the solar dynamic pressure is the increase of the ion production by charge exchange, proportional to the increase of the solar wind flux, which becomes the main contribution to the ion precipitation at high energy.
Anisotropic Vorticity Within Bursty Bulk Flow Turbulence
Authors: Zhang L. Q. , Lui A. T. Y. , Baumjohann W. , Wang Chi , Burch James L. , Khotyaintsev Yu. V.
Published: September 2020

Utilizing Magnetospheric Multiscale (MMS) observation in the tail plasma sheet, we study the vorticity field (ω =  ∇  × V) of the plasma bulk (convective) velocity within the bursty bulk flow (BBF) in detailed. Two typical events are presented. In the event on 25 June 2017, Ey is the main component. In the other event on 6 July 2017, Ez is the main component. For both cases, the BBF electric field is dominated by the convective electric field (Ec =  − V × B). Our case studies show clearly the existence of the convective vorticity field within the BBF. The vorticity field has prominent anisotropy (quantified by the anisotropic angle (θaa = arctan(ω⊥/ω∥)). More often, the BBF ω field has stronger perpendicular vorticity (ω⊥) than the parallel vorticity (ω∥). The dominance of vorticity by ω⊥‐dominating BBF is confirmed in the statistical sense. In particular, event on 25 June shows the significant evolution of the ion flux energy with the strength of the ω field. The strong ω field corresponds to the ion flux enhancement at high energy (above 10 keV), while the weak ω field corresponds to the ion flux enhancement at medium energy (2–5 keV). Investigation of the subset of channel from fast plasma investigation partial moment measurement reveals that the ion behaviors in the strong and decayed BBFs are distinctly different. The channeled ions form the narrow band distribution in the strong BBF but the multiple‐layer distribution in the weak BBF. Finally, spectrum analysis indicates that the BBF ω⊥ and ω∥ have a similar scaling about −2.0 (below 0.2 Hz).
Glacial and Hydrothermal Sources of Dissolved Iron (II) in Southern Ocean Waters Surrounding Heard and McDonald Islands
Authors: Holmes Thomas M. , Wuttig Kathrin , Chase Zanna , Schallenberg Christina , van der Merwe Pier , Townsend Ashley T. , Bowie Andrew R.
Published: September 2020

The Southern Ocean is the largest region in which iron limits the growth of phytoplankton. However, a phytoplankton bloom thousands of square kilometers in area forms each spring–summer in the Indian sector of the Southern Ocean, both above and to the east of the Kerguelen Plateau. The central region of the Kerguelen Plateau hosts the volcanically active islands, Heard and McDonald (HIMI), the former of which is largely covered by glaciers. The sources and processes governing supply of iron from HIMI to the region are relatively unknown. In the austral summer of 2016, the first voyage to focus on biogeochemical cycling in the HIMI region was undertaken (GEOTRACES process study GIpr05). Using dissolved iron (II) (DFe (II)) and hydrogen peroxide (H2O2) measurements, we are able to resolve iron sources and show that each of the adjacent islands are strong sources of reduced iron, though controlled by different supply mechanisms.

At Heard Island, the greatest DFe (II) concentrations (0.57 nmol L−1) were detected north of the island. An inverse correlation of DFe (II) concentrations with salinity suggests the origin is from a sea‐terminating glacier on the island. At McDonald Islands, the greatest DFe (II) concentrations (1.01 nmol L−1) were detected east of the islands, which, based on DFe (II) profiles from five targeted stations, appear likely to originate from shallow diffuse hydrothermalism. Elevated DFe (II) around HIMI may increase Fe availability for biota and has implications for transport of Fe away from the islands to the broader northern Kerguelen Plateau where the annual plankton bloom is strongest.
Coherent Seasonal Acceleration of the Weddell Sea Boundary Current System Driven by Upstream Winds
Authors: Le Paih Nicolas , Hattermann Tore , Boebel Olaf , Kanzow Torsten , Lüpkes Christof , Rohardt Gerd , Strass Volker , Herbette Steven
Published: September 2020

The Weddell Sea is of global importance in the formation of dense bottom waters associated with sea ice formation and ocean‐ice sheet interaction occurring on the shelf areas. In this context, the Weddell Sea boundary current system (BCS) presents a major conduit for transporting relatively warm water to the Weddell Sea ice shelves and for exporting some modified form of Wedell Sea deep and bottom waters into the open ocean. This study investigates the downstream evolution of the structure and the seasonality of the BCS along the Weddell Sea continental slope, combining ocean data collected for the past two decades at three study locations. The interannual‐mean geostrophic flow, which follows planetary potential vorticity contours, shifts from being surface intensified to bottom intensified along stream. The shift occurs due to the densification of water masses and the decreasing surface stress that occurs westward, toward the Antarctic Peninsula. A coherent along‐slope seasonal acceleration of the barotropic flow exists, with maximum speed in austral autumn and minimum speed in austral summer. The barotropic flow significantly contributes to the seasonal variability in bottom velocity along the tip of the Antarctic Peninsula. Our analysis suggests that the winds on the eastern/northeastern side of the gyre determines the seasonal acceleration of the barotropic flow. In turn, they might control the export of Weddell Sea Bottom Water on seasonal time scales. The processes controlling the baroclinic seasonality of the flow need further investigation.
Evaluating Wildfire Smoke Transport Within a Coupled Fire‐Atmosphere Model Using a High‐Density Observation Network for an Episodic Smoke Event Along Utah's Wasatch Front
Authors: Mallia Derek V. , Kochanski Adam K. , Kelly Kerry E. , Whitaker Ross , Xing Wei , Mitchell Logan E. , Jacques Alex , Farguell Angel , Mandel Jan , Gaillardon Pierre‐Emmanuel , Becnel Tom , Krueger Steven K.
Published: September 2020

One of the primary challenges associated with evaluating smoke models is the availability of observations. The limited density of traditional air quality monitoring networks makes evaluating wildfire smoke transport challenging, particularly over regions where smoke plumes exhibit significant spatiotemporal variability. In this study, we analyzed smoke dispersion for the 2018 Pole Creek and Bald Mountain Fires, which were located in central Utah. Smoke simulations were generated using a coupled fire‐atmosphere model, which simultaneously renders fire growth, fire emissions, plume rise, smoke dispersion, and fire‐atmosphere interactions. Smoke simulations were evaluated using PM2.5 observations from publicly accessible fixed sites and a semicontinuously running mobile platform. Calibrated measurements of PM2.5 made by low‐cost sensors from the Air Quality and yoU (AQ&U) network were within 10% of values reported at nearby air quality sites that used Federal Equivalent Methods. Furthermore, results from this study show that low‐cost sensor networks and mobile measurements are useful for characterizing smoke plumes while also serving as an invaluable data set for evaluating smoke transport models. Finally, coupled fire‐atmosphere model simulations were able to capture the spatiotemporal variability of wildfire smoke in complex terrain for an isolated smoke event caused by local fires. Results here suggest that resolving local drainage flow could be critical for simulating smoke transport in regions of significant topographic relief.
Biomechanical Properties and Resistance to Uprooting of Laboratory‐Scale Wood Logs
Authors: Bau' Valentina , Perona Paolo
Published: September 2020

Wood dynamics affects riparian ecosystem functioning and river morphology. The spatial and temporal dynamics of wood pieces in river corridors, in particular of deposited rejuvenated wood logs, depend on their biomechanical properties and resistance to uprooting. The ability of stranded wood logs to withstand drag forces depends on how efficiently their roots have sprouted and on the interarrival time, magnitude, and duration of the moderate floods to which they are subjected. We performed static pullout tests on small‐scale wood logs (Salix species) of four different sizes, growth stages, and sediment moisture content. Statistics of root biomass growth rate and related spatial distribution along the trunk reveal important insights for upscaling dynamics. Similarly, force‐displacement curves indicate the maximum resistance and related energy for uprooting. Autocorrelation analysis of the sequence of force drops in the force‐displacement signal reveals the statistical nature of the mechanism of load redistribution among roots. These results are then used to advance a physically based mathematical model of the resistance of wood log roots to flow‐induced drag forces. Given that the magnitude, duration, and return period of hydrologic events are typically correlated, our model implies the existence of windows of opportunity for wood logs to either survive or remobilize.
Soil Degradation Risks Assessed by the SOTE Model for Salinity and Sodicity
Authors: Kramer Isaac , Mau Yair
Published: September 2020

Soil salinity and sodicity are serious environmental hazards, with the potential to limit agricultural production and cause destructive soil degradation. These concerns are especially high in dry areas, which often rely on saline and sodic irrigation water to support agriculture. To assess long‐term soil degradation risk, we introduce the Salt of the Earth (SOTE) model, which describes the dynamics of soil water content, salinity, and sodicity, as driven by irrigation and rainfall. The SOTE model incorporates how changes in salinity and sodicity affect saturated soil hydraulic conductivity, Ks, on a soil‐specific basis. The model was successfully validated against results from a multiyear lysimeter experiment involving different irrigation water qualities and precipitation. We evaluated the impact of shorter rainy seasons on the dynamics of soil degradation in a Mediterranean climate. Critical degradation risk, indicated by reductions in Ks greater than 20%, increased from 0% to 3% when the rainy season was shortened from 130 to 80 days. Alarmingly, when irreversible degradation is allowed for, overall risk increases to 68%. Assessing the effect of irrigation water on different soils textures, we found that while greater clay fractions are usually more susceptible to dispersion, accurate risk assessment hinges on soil water dynamics. SOTE is amenable to large‐ensemble simulations of stochastic climatic conditions, for which trends in the statistics of salinization and soil degradation can be identified. As such, SOTE can be a useful land management tool, allowing planners to understand the risk of long‐term soil degradation given irrigation practices, soil qualities, and climate conditions.
On the Limitations and Implications of Modeling Heat Transport in Porous Aquifers by Assuming Local Thermal Equilibrium
Authors: Gossler Manuel A. , Bayer Peter , Rau Gabriel C. , Einsiedl Florian , Zosseder Kai
Published: September 2020

Heat transport in natural porous media, such as aquifers or streambeds, is generally modeled assuming local thermal equilibrium (LTE) between the fluid and solid phases. Yet, the mathematical and hydrogeological conditions and implications of this simplification have not been fully established for natural porous media. To quantify the occurrence and effects of local thermal disequilibrium during heat transport, we systematically compared thermal breakthrough curves from a LTE with those calculated using a local thermal nonequilibrium (LTNE) model, explicitly allowing for different temperatures in the fluid and solid phases. For the LTNE model, we developed a new correlation for the heat transfer coefficient representative of the conditions in natural porous aquifers using six published experimental results. By conducting an extensive parameter study (>50,000 simulations), we show that LTNE effects do not occur for grain sizes smaller than 7 mm or for groundwater flow velocities that are slower than 1.6 m day−1. The limits of LTE are likely exceeded in gravel aquifers or in the vicinity of pumped bores. For such aquifers, the use of a LTE model can lead to an underestimation of the effective thermal dispersion by a factor of up to 30 or higher, while the advective thermal velocity remains unaffected for most conditions. Based on a regression analysis of the simulation results, we provide a criterion which can be used to determine if LTNE effects are expected for particular conditions.
Extreme Value Snow Water Equivalent and Snowmelt for Infrastructure Design Over the Contiguous United States
Authors: Cho Eunsang , Jacobs Jennifer M.
Published: September 2020

Snowmelt‐driven floods result in large societal and economic impacts on local communities including infrastructure failures in the United States. However, the current U.S. government standard design precipitation maps are based on liquid precipitation data (e.g., National Oceanic and Atmospheric Administration's Precipitation‐Frequency Atlas 14; NOAA Atlas 14) with very limited guidance on snowmelt‐driven floods. In this study, we developed 25‐ and 100‐year return level design maps of snow water equivalent (SWE) and 1‐ and 7‐day snowmelt including precipitation events (e.g., rain‐on‐snow) using long‐term observation‐based gridded SWE developed by University of Arizona (UA) incorporating the national snow model product (SNOw Data Assimilation System; SNODAS) over the contiguous United States (CONUS). For the 44 U.S. states where the NOAA Atlas 14 maps are available, the design snowmelt values from this study exceed the standard design values in 23% of the total extent. The snowmelt values exceed the NOAA Atlas 14 design precipitation by up to 171 and 254 mm in the northeastern United States; 127 and 225 mm in the north central United States; and 191 and 425 mm in the western mountain United States for the 25‐ and 100‐year return levels, respectively. A comparison of 7‐day design snowmelt between with and without precipitation shows that including precipitation results in an average increase of 42 and 68 mm for 25‐ and 100‐year return levels, respectively, over snowmelt that do not include precipitation. The design snowmelt maps from this study complement the NOAA Atlas 14 design precipitation and provide additional guidance on infrastructure design for snowmelt‐driven floods in the CONUS.
Endothelin 1-induced retinal ganglion cell death is largely mediated by JUN activation
Authors: Marola Olivia J. , Syc-Mazurek Stephanie B. , Howell Gareth R. , Libby Richard T.
Published: September 2020

Glaucoma is a neurodegenerative disease characterized by loss of retinal ganglion cells (RGCs), the output neurons of the retina. Multiple lines of evidence show the endothelin (EDN, also known as ET) system is important in glaucomatous neurodegeneration. To date, the molecular mechanisms within RGCs driving EDN-induced RGC death have not been clarified. The pro-apoptotic transcription factor JUN (the canonical target of JNK signaling) and the endoplasmic reticulum stress effector and transcription factor DNA damage inducible transcript 3 (DDIT3, also known as CHOP) have been shown to act downstream of EDN receptors. Previous studies demonstrated that JUN and DDIT3 were important regulators of RGC death after glaucoma-relevant injures. Here, we characterized EDN insult in vivo and investigated the role of JUN and DDIT3 in EDN-induced RGC death. To accomplish this, EDN1 ligand was intravitreally injected into the eyes of wildtype, Six3-cre+Junfl/fl (Jun−/−), Ddit3 null (Ddit3−/−), and Ddit3−/−Jun−/− mice. Intravitreal EDN1 was sufficient to drive RGC death in vivo. EDN1 insult caused JUN activation in RGCs, and deletion of Jun from the neural retina attenuated RGC death after EDN insult. However, deletion of Ddit3 did not confer significant protection to RGCs after EDN1 insult. These results indicate that EDN caused RGC death via a JUN-dependent mechanism. In addition, EDN signaling is known to elicit potent vasoconstriction. JUN signaling was shown to drive neuronal death after ischemic insult. Therefore, the effects of intravitreal EDN1 on retinal vessel diameter and hypoxia were explored. Intravitreal EDN1 caused transient retinal vasoconstriction and regions of RGC and Müller glia hypoxia. Thus, it remains a possibility that EDN elicits a hypoxic insult to RGCs, causing apoptosis via JNK-JUN signaling. The importance of EDN-induced vasoconstriction and hypoxia in causing RGC death after EDN insult and in models of glaucoma requires further investigation.
RNF115 deletion inhibits autophagosome maturation and growth of gastric cancer
Authors: Li Riyong , Gu Zhaohui , Zhang Xuan , Yu Jiahong , Feng Jinqiu , Lou Yaxin , Lv Ping , Chen Yingyu
Published: September 2020

Autophagy is a highly conserved lysosome-dependent degradation system in eukaryotic cells. This process removes long-lived intracellular proteins, damaged organelles, and recycles biological material to maintain cellular homeostasis. Dysfunction of autophagy triggers a wide spectrum of human diseases, including cancer and neurodegenerative diseases. In the present study, we show that RNF115, an E3 ubiquitin ligase, regulates autophagosome–lysosome fusion and autophagic degradation under both nutrient-enriched and stress conditions. Depletion of theRNF115gene caused the accumulation of autophagosomes by impairing fusion with lysosomes, which results in an accumulation of autophagic substrates. Further investigation suggests that RNF115 interacts with STX17 and enhances its stability, which is essential for autophagosome maturation. Importantly, we provide in vitro and in vivo evidence thatRNF115inactivation inhibits the tumorigenesis and metastasis of BGC823 gastric cancer cells. We additionally show that high expression levels ofRNF115mRNA correlate with poor prognosis in gastric cancer patients. These findings indicate that RNF115 may play an evolutionarily conserved role in the autophagy pathway, and may act to maintain protein homeostasis under physiological conditions. These data demonstrate the need to further evaluate the potential therapeutic implications of RNF115 in gastric cancer.
A hyperbranched polymer from tung oil for the modification of epoxy thermoset with simultaneous improvement in toughness and strength
Authors: Xiao Laihui , Liu Zengshe , Li Nan , Li Shuai , Fu Pan , Wang Yigang , Huang Jinrui , Chen Jie , Nie Xiaoan
Published: September 2020

In order to increase the toughness of epoxy resin and make full use of biological resources, a tung oil-based hyperbranched polymer (TOHBP) was synthesized.
pH-Responsive dopamine-based nanoparticles assembledviaSchiff base bonds for synergistic anticancer therapy
Authors: Li Hong , Zhao Yuanyuan , Jia Yi , Chen Gang , Peng Junxia , Li Junbai
Published: September 2020

Dopamine-based nanoparticles are constructedviaSchiff base bonds to serve as pH-responsive drug nanocarriers for combined photodynamic therapy and chemotherapy.
In situ embedding dual-Fe nanoparticles in synchronously generated carbon for the synergistic integration of magnetic resonance imaging and drug delivery
Authors: Zhang Hui , Zhang Jianping , Zhang Qianqian , Liu Xiaofeng , Yang Yongtai , Ling Yun , Zhou Yaming
Published: September 2020

Inspired by the phenomenon of uniovular twins in nature, dual-Fe nanoparticles functionalized ordered mesoporous carbon have been one-pot facilely prepared, achieving the synergistic intergration of MRI effects with drug delivery property.
A thixotropic supramolecular metallogel with a 2D sheet morphology: iodine sequestration and column based dye separation
Authors: Alam Noohul , Sarma Debajit
Published: September 2020

A lamellar thixotropic supramolecular metallogel (Mg@DEOA) with a 2D sheet morphology as an adsorbent/separating column material for iodine and water soluble organic dyes.
Oscillatory structural forces between charged interfaces in solutions of oppositely charged polyelectrolytes
Authors: Kubiak Katarzyna , Maroni Plinio , Trefalt Gregor , Borkovec Michal
Published: September 2020

Forces between negatively charged micron-sized silica particles were measured in aqueous solutions of cationic polyelectrolytes with the atomic force microscope (AFM).
Iron-based nano-structured surfaces with antimicrobial properties
Authors: Yi Guangshun , Teong Siew Ping , Liu Shaoqiong , Chng Shuyun , Yang Yi Yan , Zhang Yugen
Published: September 2020

Bactericidal nanopillar array surfaces of FeOOH and Fe2O3 have been prepared as a cicada wing mimic. An even simpler structure-based antimicrobial surface was also made by coating with sea urchin-like FeOOH and Fe2O3 particles with a binder.
Vascular toxicity associated with anti-angiogenic drugs
Authors: Neves Karla B. , Montezano Augusto C. , Lang Ninian N. , Touyz Rhian M.
Published: September 2020

Over the past two decades, the treatment of cancer has been revolutionised by the highly successful introduction of novel molecular targeted therapies and immunotherapies, including small-molecule kinase inhibitors and monoclonal antibodies that target angiogenesis by inhibiting vascular endothelial growth factor (VEGF) signaling pathways. Despite their anti-angiogenic and anti-cancer benefits, the use of VEGF inhibitors (VEGFi) and other tyrosine kinase inhibitors (TKIs) has been hampered by potent vascular toxicities especially hypertension and thromboembolism. Molecular processes underlying VEGFi-induced vascular toxicities still remain unclear but inhibition of endothelial NO synthase (eNOS), reduced nitric oxide (NO) production, oxidative stress, activation of the endothelin system, and rarefaction have been implicated. However, the pathophysiological mechanisms still remain elusive and there is an urgent need to better understand exactly how anti-angiogenic drugs cause hypertension and other cardiovascular diseases (CVDs). This is especially important because VEGFi are increasingly being used in combination with other anti-cancer dugs, such as immunotherapies (immune checkpoint inhibitors (ICIs)), other TKIs, drugs that inhibit epigenetic processes (histone deacetylase (HDAC) inhibitor) and poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors, which may themselves induce cardiovascular injury. Here, we discuss vascular toxicities associated with TKIs, especially VEGFi, and provide an up-to-date overview on molecular mechanisms underlying VEGFi-induced vascular toxicity and cardiovascular sequelae. We also review the vascular effects of VEGFi when used in combination with other modern anti-cancer drugs.
Methodology for assessing the network balance of 4G LTE radio network
Authors: Cheon K. , Kwon H. , Jahng J. , Park S. , Choi J.K.
Published: September 2020

The mobile network operators should expand their network capacity as service traffic increases in mobile networks. It is important to balance network capacity and traffic volume in terms of service quality and operating costs, and this network balance can be quantified by the capacity margin, which is defined as the difference between network capacity and traffic volume. There are two approaches to assess the network capacity: single‐cell and national scale. However, the single‐cell approach has too narrow to estimate the whole operator network, and the national scale approach should consider regional traffic density distribution. This Letter proposes a methodology for assessing the capacity margin from the perspective of traffic‐intensive regions where the actual network balance is determined. The authors introduce the concept of a virtual sample region that consists of traffic‐intensive cells in the metropolitan area. Then they show the methodology to estimate and predict the network capacity and traffic trends in this region. Finally, they derive the capacity margin of the mobile network. They used the real measured data in the top 10% traffic‐intensive cells about three years in Seoul, South Korea, and evaluated 4G downlink capacity margin in this region until 2024.
PV panels Rs parasitic resistance degradation estimation by means of the MPPT controller modified operation: the M ‐factor calculation
Authors: Sánchez‐Pacheco F.J. , Heredia‐Larrubia J.R. , Petrone G. , Sidrach‐de‐Cardona M.
Published: September 2020

This Letter describes a method to quantify online and in real‐time, the level of degrading of the series parasitic resistance R s of a photovoltaic (PV) panel. This method aims to obtain the herein proposed M ‐factor, which results from the calculation of the slopes of the I–V curve in the boundaries of its maximum power‐point. For this purpose, the slight modification of the maximum power‐point tracker controller’ perturb and observe algorithm is required. This procedure can be easily integrated into its firmware with no additional costs. The M ‐factor calculation is performed instantaneously and since no disconnection is required, no significant power losses are produced.
Reliability enhanced SiC MOSFET with partially widened retrograde P‐well structure
Authors: Liu Jiawei , Lu Jiang , Tian Xiaoli , Chen Hong , Bai Yun , Liu Xinyu
Published: September 2020

In this Letter, a 1.2 kV SiC power MOSFET with a partially widened retrograde P‐well (RP) structure and N ‐implanting region is proposed to enhance the device's reliability. Compared with the conventional SiC power MOSFET, the short circuit (SC) ability of the proposed structure can be improved effectively without sacrificing other performance. Simulation results reveal that a 40% reduction of the SC saturation current can be achieved, resulting in the SC withstand time increase from 7 to 10 μs at the DC‐link voltage 800 V. Moreover, a better gate oxide reliability at 1.2 kV blocking condition also can be achieved. The peak electric field at the gate oxide interface is decreased by ∼48% owing to the shielding effect of the RP structure. In addition, the fabrication technology of the proposed structure is compatible with the standard planar SiC MOSFET manufacture process only with a few additional implanting steps. Therefore, this new MOSFET structure provides a simple and effective way to optimise the reliability of the planar SiC power MOSFET.
Target trajectory estimation by unambiguous phase differences from a single fixed passive sensor
Authors: Ren Jinlong , Wei Guohua , Bai Jiahao , Bao Xiaojie , Wang Xu
Published: September 2020

In this Letter, considering the configuration of small antenna array aperture used for special usage, the authors proposed a target trajectory estimation method by unambiguous phase differences with prior knowledge on target velocity from a single fixed passive sensor. First, they developed the maximum likelihood estimator of the target trajectory parameters based on unambiguous phase differences and then deduce the corresponding Cramer–Rao lower bound. Furthermore, in terms of the error in prior knowledge on target velocity, the influence of target velocity mismatch on trajectory parameters estimation is analysed. Finally, they evaluated the performance of the proposed method and validated the correctness of their analysis via numerical simulation.
Electromagnetic modelling of an active integrated antenna array using MoM‐GEC method in conjunction with genetic algorithms for 5G beam synthesis applications
Authors: Soltani T. , Soltani I. , Aguili T.
Published: September 2020

This Letter presents an electromagnetic modelling of an active integrated antenna array for 5G mobile communication. Here, the authors propose a functional method for active‐integrated antenna array synthesis, based on the method of moments combined with the generalised equivalent circuit (MoM‐GEC) in conjunction with a genetic algorithm for the synthesis of a 2D array with switched phase states. Their design strategy is applied to search for the optimal phase matrix with a directional beam and minimum side‐lobe level.
Frequency comb investigation of monolithic mode‐locked GaSb‐based laser at 1.7 µm by heterodyne detection
Authors: Becker S. , Weih R. , Scheuermann J. , Rößner K. , Kistner C. , Koeth J. , Höfling S. , Kamp M.
Published: September 2020

In this work, monolithic mode‐locked GaSb‐based lasers at 1.7 µm emission wavelength with heterodyne measurement of the frequency comb are presented. Mode‐locking operation was confirmed by measuring the optical beatnote at the round‐trip frequency of 9.56 GHz and analysing the frequency comb. Mode‐locking operation occurred from 0.1 to 3.3 V reverse bias voltages at the absorber section and driving currents from 160 to 400 mA at the laser section with a minimum beatnote width of 6.6 kHz. The frequency comb spans over 13 nm with a mode spacing of 0.10 nm, measured by heterodyne‐detection with a distributed feedback laser.
Lateral confinement of high‐impedance surface‐waves through reinforcement learning
Authors: Morocho‐Cayamcela M.E. , Lim W.
Published: September 2020

The authors present a model‐free policy‐based reinforcement learning model that introduces perturbations on the pattern of a metasurface. The objective is to learn a policy that changes the size of the patches, and therefore the impedance in the sides of an artificially structured material. The proposed iterative model assigns the highest reward when the patch sizes allow the transmission along a constrained path and penalties when the patch sizes make the surface wave radiate to the sides of the metamaterial. After convergence, the proposed model learns an optimal patch pattern that achieves lateral confinement along the metasurface. Simulation results show that the proposed learned‐pattern can effectively guide the electromagnetic wave through a metasurface, maintaining its instantaneous eigenstate when the homogeneity is perturbed. Moreover, the pattern learned to prevent reflections by changing the patch sizes adiabatically. The reflection coefficient shows that most of the power gets transferred from the source to the destination with the proposed design.
Efficient solution of Noye–Hayman implicit finite‐difference method for modelling wave propagation in tunnels
Authors: Rasool H.F. , Qureshi M.A. , Aziz A. , Malik F.H.
Published: September 2020

Parabolic equation models discretised with the finite‐difference method have been a research topic for a long time. Through the simulation of electromagnetic wave propagation characteristics in typical scenarios, it is pointed out that the fast algorithm needs to be developed for the solution of two‐level Noye–Hayman (NH2) implicit method to meet the accuracy and computational requirements of electromagnetic wave propagation problems in three‐dimensional environments. In this Letter, hierarchical skeletonisation is used for an efficient inversion of three‐dimensional parabolic equation discretised by the NH2 implicit method which is the modification of conventional Crank–Nicolson (CN) method. Numerical results show that the NH2 implicit method is more accurate than the CN method at no additional cost for a given numerical example.
Improved multiscale local phase quantisation histogram for the recognition of blurred dorsal hand vein images
Authors: Liu Fu , Jiang Shoukun , Kang Bing , Hou Tao
Published: September 2020

Vein texture elements in images are sometimes degraded due to centrally symmetric blur, e.g. due to motion of hand or camera not being in focus, which significantly affects recognition systems performance. Multiscale local phase quantisation (MLPQ) can effectively improve system accuracy in the presence of blur by dividing vein images into non‐overlapping blocks and extracting multiscale local phase information. However, MLPQ misses some important discriminant information at the intersections of different regions, which leaves room for improving the system performance. In the present work, a multiscale overlapping blocks local phase quantisation (MOLPQ) histogram algorithm is presented to divide the vein image into overlapping blocks and extract multiscale local phase information, which includes the discriminant information lost in MLPQ. MOLPQ is validated via comparison with state‐of‐the‐art recognition algorithms on a normal hand vein database, artificial‐blur databases, and a normal‐blur database, and the accuracies on the normal hand vein and normal‐blur databases are 99.57 and 98.07%, respectively. Additionally, MOLPQ outperforms other methods on all databases in terms of accuracy.
Spike‐driven gated recurrent neural network processor for electrocardiogram arrhythmias detection realised in 55‐nm CMOS technology
Authors: Wu Yuancong , Liu Y.H. , Liu Shuang , Yu Q. , Chen T.P. , Liu Y.
Published: September 2020

In this Letter, an asynchronous spike‐driven processor based on gated recurrent neural network algorithm for electrocardiogram (ECG) cardiac arrhythmias detection has been designed. Based on the processor, the proposed ECG detection model, containing a many‐to‐many gated recurrent unit layer and a fully connected layer, can achieve a high classification overall accuracy of 97.8% using the MIT‐BIH arrhythmia database. The processor was fabricated in 55‐nm 1P6M CMOS technology. It integrates about 1.4 million logic gates, including 40 KB of on‐chip memory within a die area. The test chip consumes 6.28 mW at real‐time operation frequency (200 MHz) with 1.2 V core supply voltage and at 1 kHz.
Focusing the temporally interfering electric fields in non‐invasive deep brain stimulation
Authors: Honarbakhsh B. , Mohammadzadeh M.
Published: September 2020

A new design of non‐invasive deep bring stimulation system is presented that works based on temporally interfering (TI) electrical fields and high‐spatial resolution. The proposed system exploits an increased number of exciting electrical current sources placed around the head transracially to adjust the area and position of the desired region for brain deep neural activation. Only two operational frequencies are used. It is shown that the previously reported TI method can be effectively and systematically extended to focus the amplitude‐modulated electric field on the desired location. Results demonstrate that by increasing the number of exciting sources to 40, the spatial resolution of the proposed system can be decreased at least by a factor of 5.8.
Advances in colour transfer
Authors: Pitié Francois
Published: September 2020

Colour grading is an essential step in movie post‐production, which is done in the industry by experienced artists on expensive edit hardware and software suites. This paper presents a review of the advances made to automate this process. The review looks in particular at how the state‐of‐the‐art in optimal transport and deep learning has advanced some of the fundamental problems of colour transfer, and how far are we still from being able to automatically grade images.
Operation strategy of park microgrid with multi‐stakeholder based on bi‐level optimisation
Authors: Kong Xiangyu , Liu Dehong , Sun Fangyuan , Chen Songsong , Li Shupeng
Published: September 2020

The new reform of power system promotes the market‐oriented operation of microgrids. The ubiquitous power internet of things provide support in information, data, and computation to microgrids in market operation, energy management, and coordination interaction. This study takes the park microgrid with multi‐stakeholder as the object, establishes a two‐level optimisation model of microgrid bidding transaction based on multi‐agent system. In the lower level optimisation, considering the deviation penalty of power generation and the previous round bidding results, the optimal bidding strategy model is established by the bidding unit agent to maximise its benefit. In the upper‐level model, bidding strategies of distributed energy resources (DERs) as constraints, a multiple objective mixed‐integer linear programming model was built to optimise the overall objectives of clearing price and imbalanced deviation, searching for the optimal clearing price and the generation plan of DERs. The results were fed back to the DERs to help them form the next round of strategies until the result reaches equilibrium. The proposed optimised operation mode is compared with the traditional operation mode in the case study, verifying that the proposed method can realise the optimal operation of the microgrid and the coordinated interaction with the main grid, increasing the benefit of stakeholders.
Coordination of multi‐type FACTS for available transfer capability enhancement using PI–PSO
Authors: Sadiq Ahmad Abubakar , Buhari Muhammad , Adamu Sunusi Sani , Musa Haruna
Published: September 2020

To relieve congestion due to open‐access feature in competitive power system framework, utilities plan flexible alternating current transmission systems (FACTS), ensuring improved utilization and performance of the transmission infrastructure. However, high‐investment cost restricts implementation to single type of FACTS' planning in a time. Therefore, successive planning of another FACTS to delay transmission expansion results in multi‐type FACTS planning. Consequently, to optimise performance, subsequent planning must coordinate with existing FACTS. The main objective of this study is to implement coordination of multi‐type FACTS for available transfer capability (ATC) enhancement. A hybrid real power flow performance index (PI) and particle swarm optimisation (PSO), coordinate thyristor control series compensator (TCSC) in the first planning horizon with static synchronous series compensator (SSSC) and unified power flow controller (UPFC), in the second horizon. The PI–PSO‐based multi‐type FACTS coordination improves ATC of multilateral power transfers in a standard 9‐buses test network. Results show that multi‐type FACTS achieved higher ATC; such that enhanced ATC by TCSC–SSSC ranges between 8.06–69.34% while the TCSC–UPFC ranges between 11.85–71.59% for various power transfer transactions. A comparison of the three coordination schemes shows that the scheme with more decision parameters provides superior loadability and transfer capability improvement.