bluuebunny/crossref_metadata_2025 huggingface dataset:
A Statistical Survey of Low‐Frequency Magnetic Fluctuations at Saturn
Authors: Pan Dong‐Xiao , Yao Zhong‐Hua , Guo Rui‐Long , Bonfond Bertrand , Wei Yong , Dunn William , Zhang Bin‐Zheng , Zong Qiu‐Gang , Zhou Xu‐Zhi , Grodent Denis , Wan Wei‐Xing
Published: December 2020

Low‐frequency waves are closely related to magnetospheric energy dissipation processes. The Cassini spacecraft explored Saturn's magnetosphere for over 13 years, until September 2017, covering a period of more than a complete solar cycle. Using this rich heritage data set, we systematically investigated key physical parameters of low‐frequency waves in Saturn's magnetosphere, including their local time distribution and the dependence on solar activity. We found that the wave activity peaked in the near noon sector. For the nightside, the wave intensity also appeared to peak pre and postmidnight. Due to the limited local time coverage for each solar phase, we were not able to draw a firm conclusion on the wave's dependence on solar activity. In general, the wave power showed a monotonically decreasing trend toward larger distances in nightside sectors especially during the declining phase, which implied that low‐frequency waves mainly originate from the relatively inner regions of the magnetosphere. On the dayside, stronger waves were mostly located at/within ∼25 Rs, near the magnetopause. The study shows a global picture of low‐frequency waves in Saturn's magnetosphere, providing important implications for how magnetospheric energy dissipates into Saturn's polar ionosphere and atmosphere.
Geomagnetic Activity Effects on CO2‐Driven Trend in the Thermosphere and Ionosphere: Ideal Model Experiments With GAIA
Authors: Liu Huixin , Tao Chihiro , Jin Hidekatsu , Abe Takamichi
Published: December 2020

We examine impacts of geomagnetic activity (GA) on CO2‐driven trend in the ionosphere and thermosphere using the Ground‐to‐topside Atmosphere Ionosphere model for Aeronomy whole atmosphere model. The model reveals three salient features. (1) Geomagnetic activities usually weakens the CO2‐driven trend at a fixed altitude. Among the IT parameters analyzed, the thermosphere mass density is the most robust indicator for CO2 cooling effect even with GA influences. (2) Geomagnetic activities can either strengthen or weaken the CO2‐driven trend in hmF2 and NmF2, depending on local time and latitudes. This renders the widely used linear fitting methods invalid for removing geomagnetic effects from observations. (3) An interdependency exists between the efficiency of CO2 forcing and geomagnetic forcing, with the former enhances at lower GA level, while the latter enhances at higher CO2 concentration. This could imply that the CO2‐driven trend would accelerate in periods of declining GA, while magnetic storms may have larger space weather impacts in the future with increasing CO2. These findings provide a preliminary model framework to understand interactions between the CO2 forcing from below and the geomagnetic forcing from above.
Ion Velocity and Temperature Variation Around Topside Nighttime Irregularities: Contrast Between Low‐ and Mid‐Latitude Regions
Authors: Park Jaeheung , Heelis Roderick , Chao Chi Kuang
Published: December 2020

Studies on low‐/mid‐latitude ionospheric irregularities have a long history, but ion temperature and drift velocity variations within the irregularities have been rarely investigated, especially at mid‐latitudes. To fill this knowledge gap, we statistically investigate ion temperature and velocity of mid‐latitude ionospheric irregularities and compare them to those of low‐latitude ones. This study mainly relies on in situ plasma moment data from the newly launched Ionospheric Connection Explorer (ICON) satellite and is supplemented by Republic of China Satellite 1 (ROCSAT‐1) data in 2000–2004. At low latitudes (|MLAT|<10°) plasma density irregularities encountered by ICON have the following properties: lower‐density regions have cooler ions and more poleward/westward/outward velocity than the ambient plasma, which agrees with previous reports on equatorial plasma bubbles. At mid‐latitudes (|MLAT| = 10°∼30°), the opposite trends are observed: lower‐density regions have hotter ions and more equatorward/eastward/inward drift than the ambient, which is a new finding in this study. The mid‐latitude observations can be put into the context of Medium‐Scale Traveling Ionospheric Disturbance (MSTID) properties reported previously, which evidences that topside irregularities at nighttime mid‐latitudes generally represent MSTIDs. ROCSAT‐1 data support the contrast between low‐ and mid‐latitude ionospheric irregularities.
Remote Sensing of Magnetic Reconnection in the Magnetotail Using In Situ Multipoint Observations at the Plasma Sheet Boundary Layer
Authors: Wellenzohn S. , Nakamura R. , Nakamura T. K. M. , Varsani A. , Sergeev V. A. , Apatenkov S. V. , Holmes J. C. , Grigorenko E. E. , Burch J. L. , Giles B. L. , Torbert R. B.
Published: December 2020

Characteristics of the reconnection region are examined based on Magnetospheric Multiscale (MMS) observation of a plasma sheet boundary layer crossing on July 12, 2018 when both high‐energy (>few keV) electrons as well as ions flowing parallel to the magnetic field showed distinct energy dispersion. Remote sensing techniques are applied to estimate location of reconnection region and injection time of these particles. The reconnection region is estimated to be located at X = (−23 ± 1.9) RE from electrons, comparable to that from ions, X = (−24.5 ± 0.7) RE by taking into account the time of flight effect as well as the effect of separatrix motion relative to the plasma. The electron injection times precede that of ions by ∼6 s. We found that the time dispersed energetic electron beams away from X‐line are accompanied by short‐lived high‐frequency parallel‐electric field disturbances around plasma frequency. These wave packets are the first observable remote feature of reconnection. Using multi‐point measurements of high energy ions, electrons, magnetic field, and parallel‐electric field disturbances, reconnection electric field is estimated as 1.6–2.5 mV/m initially and decrease to ∼0.8 mV/m within ∼20 s. This study shows that the remote sensing scheme is an alternative method to infer the temporal/spatial changes of the magnetotail reconnection.
A Unified Model of Crustal Stress Heterogeneity From Borehole Breakouts and Earthquake Focal Mechanisms
Authors: Luttrell Karen , Hardebeck Jeanne
Published: December 2020

Observations of crustal stress orientation from the regional inversion of earthquake focal mechanisms often conflict with those from borehole breakouts, possibly indicating local stress heterogeneity, either laterally or with depth. To investigate this heterogeneity, we compiled SHmax estimates from previous studies for 57 near‐vertical boreholes with measured breakout azimuths across the Los Angeles region. We identified subsets of earthquake focal mechanisms from established earthquake catalogs centered around each borehole with various criteria for maximum depth and maximum lateral distance from the borehole. Each subset was independently inverted for 3‐D stress orientation and corresponding SHmax probability distributions, then compared with the corresponding borehole breakout‐derived estimate. We find good agreement when both methods sample the basement stress (breakouts are close to the sediment‐basement interface), or when both methods sample the mid‐basin stress (sufficient earthquakes are present within a sedimentary basin). Along sedimentary basin margins, in contrast, we find acceptable agreement only when focal mechanisms are limited to shallow and close earthquakes, implying short‐length‐scale heterogeneity of <20 km. While the region as a whole shows evidence of both lateral and vertical stress orientation heterogeneity, we find a more homogeneous stress state within basement rock, over length scales of 1–35 km. These results reconcile the apparently conflicting observations of short‐length‐scale heterogeneity observed in boreholes, which sample primarily the basins, with the relative homogeneity of stress inferred from focal mechanisms, which sample primarily the basement, and imply distinct regimes for the appropriate use of each type of stress indicator.
The Role of Waves and Heat Exchange in the Hydrodynamics of Multi‐Basin Bays: The Example of Cádiz Bay (Southern Spain)
Authors: Zarzuelo C. , López‐Ruiz A. , Ortega‐Sánchez M.
Published: December 2020

Multi‐basin bays constitute one of the most complex coastal environments, as tides, waves, freshwater discharges and air‐water heat exchange often coexist in basins with very different characteristics, ranging from low‐friction open water bodies directly connected to the open sea to narrow, highly frictional shallow creek systems with no connection to the open sea. Although the influence of tides and baroclinic gradients in these areas is relatively well known, the role of waves in the hydrodynamics and distributions of density, salinity and temperature has received less attention. The aim of this research is to evaluate the effects of waves and heat exchange on the hydrodynamics of multiple basins through numerical modeling. The model is calibrated and tested in a mesotidal bay in Southern Spain with five different basins; the results are used to analyze the momentum balance equation and the salinity, temperature and density distributions for simulations with and without consideration of waves. The results show that baroclinic density gradients often dominate the hydrodynamics in highly frictional, shallow basins of the bay where the air‐water heat exchange is more efficient. Waves can also modify the hydrodynamics of basins directly connected to open sea by increasing flow velocities and causing deviations of baroclinic density gradients, increasing the importance of tidal stresses in low frictional basins, while increasing baroclinic density gradients in narrow, highly frictional basins.
The South Atlantic Meridional Overturning Circulation and Mesoscale Eddies in the First GO‐SHIP Section at 34.5°S
Authors: Manta G. , Speich S. , Karstensen J. , Hummels R. , Kersalé M. , Laxenaire R. , Piola A. , Chidichimo M. P. , Sato O. T. , Cotrim da Cunha L. , Ansorge I. , Lamont T. , van den Berg M.A. , Schuster U. , Tanhua T. , Kerr R. , Guerrero R. , Campos E. , Meinen C. S.
Published: December 2020

The variability of the Atlantic meridional overturning circulation (AMOC) has considerable impacts on the global climate system. Past studies have shown that changes in the South Atlantic control the stability of the AMOC and drive an important part of its variability. That is why significant resources have been invested in a South (S)AMOC observing system. In January 2017, the RV Maria S. Merian conducted the first GO‐SHIP hydrographic transect along the SAMOC‐Basin Wide Array (SAMBA) line at 34.5°S in the South Atlantic. This paper presents estimates of meridional volume, freshwater (MFT), and heat (MHT) transports through the line using the slow varying geostrophic density field and direct velocity observations. An upper and an abyssal overturning cell are identified with a strength of 15.64 ± 1.39 Sv and 2.4 ± 1.6 Sv, respectively. The net northward MHT is 0.27 ± 0.10 PW, increasing by 0.12 PW when we remove the observed mesoscale eddies with a climatology derived from the Argo floats data set. We attribute this change to an anomalous predominance of cold core eddies during the cruise period. The highest velocities are observed in the western boundary, within the Brazil and the Deep Western Boundary currents. These currents appear as a continuous deep jet located 150 km off the slope squeezed between two cyclonic eddies. The zonal changes in water masses properties and velocity denote the imprint of exchange pathways with both the Southern and the Indian oceans.
Tracking the Stratosphere‐to‐Surface Impact of Sudden Stratospheric Warmings
Authors: Hall Richard J. , Mitchell Daniel M. , Seviour William J. M. , Wright Corwin J.
Published: December 2020

Sudden stratospheric warming (SSW) events are extreme atmospheric regimes which can have a signature in surface weather up to 40 days after event onset in the stratosphere. SSWs can be classified as either vortex splitting or vortex displacement events, with the nature and timing of the surface impact potentially being different between the two. In this study, using ERA40/Interim reanalysis data, we develop a simple empirical downward tracking algorithm which for the first time allows us to estimate the time of surface impact for individual SSW events. We show that the surface impact following splitting events is, on average, about 1 week earlier than following displacement events, albeit with considerable variability. By compositing tropospheric responses around the identified date of surface impact, rather than around the central stratospheric onset date as common in previous studies, we can better constrain the surface signal of SSWs. We find that while the difference in North Atlantic Oscillation anomalies between split and displacement vortices is small, surface temperature anomalies over northwest Europe and northern Eurasia are significantly colder for splitting events, particularly over the UK just prior to the surface impact date. Displacement events on average are wetter over Northwest Europe around the time of surface impact, consistent with the jet stream being displaced further south in response to split events. Our downtracking algorithm can be used with any reanalyzes and gridded model data, and therefore will be a valuable tool for use with the latest climate models.
Magnetic Induction Responses of Jupiter's Ocean Moons Including Effects From Adiabatic Convection
Authors: Vance S. D. , Styczinski M. J. , Bills B. G. , Cochrane C. J. , Soderlund K. M. , Gómez‐Pérez N. , Paty C.
Published: December 2020

Prior analyses of oceanic magnetic induction within Jupiter's large icy moons have assumed uniform electrical conductivity. However, the phase and amplitude responses of the induced fields will be influenced by the natural depth‐dependence of the electrical conductivity. Here, we examine the amplitudes and phase delays for magnetic diffusion in modeled oceans of Europa, Ganymede, and Callisto. For spherically symmetric configurations, we consider thermodynamically consistent interior structures that include realistic electrical conductivity along the oceans' adiabatic temperature profiles. Conductances depend strongly on salinity, especially in the large moons. The induction responses of the adiabatic profiles differ from those of oceans with uniform conductivity set to values at the ice–ocean interface, or to the mean values of the adiabatic profile, by more than 10% for some signals. We also consider motionally induced magnetic fields generated by convective fluid motions within the oceans, which might optimistically be used to infer ocean flows or, pessimistically, act to bias the ocean conductivity inversions. Our upper‐bound scaling estimates suggest this effect may be important at Europa and Ganymede, with a negligible contribution at Callisto. Based on end‐member ocean compositions, we quantify the magnetic induction signals that might be used to infer the oxidation state of Europa's ocean and to investigate stable liquids under high‐pressure ices in Ganymede and Callisto. Fully exploring this parameter space for the sake of planned missions requires thermodynamic and electrical conductivity measurements in fluids at low temperature and to high‐salinity and pressure as well as modeling of motional induction responses.
Extensive Urban Green Roof Shows Consistent Annual Net Uptake of Carbon as Documented by 5 Years of Eddy‐Covariance Flux Measurements
Authors: Konopka J. , Heusinger J. , Weber S.
Published: December 2020

Vegetated roofs or green roofs may supply a number of different urban ecosystem services such as thermal regulation of local air temperature by evaporative cooling or climate change mitigation by sequestration of CO2. However, knowledge about the annual and seasonal variations of green roof carbon uptake due to changes in meteorological conditions and water availability remains scarce. We studied the annual variation of net ecosystem exchange (NEE) by eddy‐covariance flux measurements during a 5‐year period from 2014 to 2019 on a large and unirrigated green roof at the Berlin‐Brandenburg airport (BER) in Berlin, Germany. The roof vegetation was dominated by Sedum species and herbs. The BER green roof showed net uptake of carbon in each of the 5 study years with an average uptake of −141.1 g C m−2 y−1 and an average measurement uncertainty of ±15.5 g C m−2 y−1. The NEE, however, was characterized by significant interannual variation in which the maximum annual uptake of −189 g C m−2 y−1 in a year with above average precipitation roughly doubles the minimum uptake of −95 g C m−2 y−1 in a dry year. The variation of NEE was a function of the annual amount of precipitation and the frequency of rainfall, that is, the number of dry days per year (DDY). The roof might lose its carbon uptake function in a warmer future climate with an increasing number of DDY. Sustainable irrigation of the roof (e.g., rainwater harvesting) could help to maintain the carbon uptake function of the green roof vegetation.
Coastal Forest Seawater Exposure Increases Stem Methane Concentration
Authors: Norwood Matthew J. , Ward Nicholas D. , McDowell Nate G. , Myers‐Pigg Allison N. , Bond‐Lamberty Ben , Indivero Julia , Pennington Stephanie , Wang Wenzhi , Kirwan Matt , Hopple Anya M. , Megonigal J. Patrick
Published: December 2020

Methane (CH4) exchange between trees and the atmosphere has recently emerged as an important, but poorly quantified process regulating global climate. The sources (soil and/or tree) and mechanisms driving the increase of CH4 in trees and degassing to the atmosphere are inadequately understood, particularly for coastal forests facing increased exposure to seawater. We investigated the eco‐physiological relationship between tree stem wood density, soil and stem oxygen saturation (an indicator of redox state), soil and stem CH4 concentrations, soil and stem carbon dioxide (CO2) concentrations, and soil salinity in five forests along the United States coastline. We aim to evaluate the mechanisms underlying greenhouse gas increase in trees and the influence of seawater exposure on stem CH4 accumulation. Seawater exposure corresponded with decreased tree survival and increased tree stem methane. Tree stem wood density was significantly correlated with increased stem CH4 in seawater exposed gymnosperms, indicating that dying gymnosperm trees may accumulate higher levels of CH4 in association with seawater flooding. Further, we found that significant differences in seawater exposed and unexposed gymnosperm tree populations are associated with increased soil and stem CH4 and CO2, indicating that seawater exposure significantly impacts soil and stem greenhouse gas abundance. Our results provide new insight into the potential mechanisms driving tree CH4 accumulation within gymnosperm coastal forests.
STAT3 ameliorates cognitive deficits by positively regulating the expression of NMDARs in a mouse model of FTDP-17
Authors: Hong Xiao-Yue , Wan Hua-Li , Li Ting , Zhang Bing-Ge , Li Xiao-Guang , Wang Xin , Li Xiao , Liu Qian , Chen Chong-Yang , Yang Ying , Wang Qun , Li Shu-Peng , Yu Hao , Wang Jian-Zhi , Yang Xi-Fei , Liu Gong-Ping
Published: December 2020

In tauopathies, memory impairment positively strongly correlates with the amount of abnormal tau aggregates; however, how tau accumulation induces synapse impairment is unclear. Recently, we found that human tau accumulation activated Signal Transduction and Activator of Transcription-1 (STAT1) to inhibit the transcription of synaptic N-methyl-D-aspartate receptors (NMDARs). Here, overexpressing human P301L mutant tau (P301L-hTau) increased the phosphorylated level of Signal Transduction and Activator of Transcription-3 (STAT3) at Tyr705 by JAK2, which would promote STAT3 translocate into the nucleus and activate STAT3. However, STAT3 was found mainly located in the cytoplasm. Further study found that P301L-htau acetylated STAT1 to bind with STAT3 in the cytoplasm, and thus inhibited the nuclear translocation and inactivation of STAT3. Knockdown of STAT3 in STAT3flox/flox mice mimicked P301L-hTau-induced suppression of NMDARs expression, synaptic and memory impairments. Overexpressing STAT3 rescued P301L-hTau-induced synaptic and cognitive deficits by increasing NMDARs expression. Further study proved that STAT3 positively regulated NMDARs transcription through direct binding to the specific GAS element of NMDARs promoters. These findings indicate that accumulated P301L-hTau inactivating STAT3 to suppress NMDARs expression, revealed a novel mechanism for tau-associated synapse and cognition deficits, and STAT3 will hopefully serve as a potential pharmacological target for tauopathies treatment.
m6A RNA methylation-mediated HNF3γ reduction renders hepatocellular carcinoma dedifferentiation and sorafenib resistance
Authors: Zhou Tengfei , Li Shichao , Xiang Daimin , Liu Junyu , Sun Wen , Cui Xiuliang , Ning Beifang , Li Xiao , Cheng Zhuo , Jiang Weiqi , Zhang Cheng , Liang Xijun , Li Liang , Cheng Xin , Hui Liu , Wang Hongyang , Ding Jin
Published: December 2020

Hepatocyte nuclear factor 3γ (HNF3γ) is a hepatocyte nuclear factor, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unclear. Herein, we report that HNF3γ expression is downregulated in patient HCC and inversely correlated with HCC malignancy and patient survival. Moreover, our data suggested that the HNF3γ reduction in HCC could be mediated by METTL14-dependent m6A methylation of HNF3γ mRNA. HNF3γ expression was increased during hepatic differentiation and decreased in dedifferentiated HCC cells. Interestingly, HNF3γ delivery promoted differentiation of not only HCC cells but also liver CSCs, which led to suppression of HCC growth. Mechanistic analysis suggested an HNF3γ-centered regulatory network that includes essential liver differentiation-associated transcription factors and functional molecules, which could synergistically facilitate HCC cell differentiation. More importantly, enforced HNF3γ expression sensitized HCC cells to sorafenib-induced growth inhibition and cell apoptosis through transactivation of OATP1B1 and OATP1B3 expression, which are major membrane transporters for sorafenib uptake. Clinical investigation showed that patient-derived HCC xenografts with high HNF3γ expression exhibited a sorafenib response and patients with high HCC HNF3γ levels benefited from sorafenib therapy. Together, these results suggest that HNF3γ plays an essential role in HCC differentiation and may serve as a therapeutic target and predictor of sorafenib benefit in patients.
Kindlin-2 regulates skeletal homeostasis by modulating PTH1R in mice
Authors: Fu Xuekun , Zhou Bo , Yan Qinnan , Tao Chu , Qin Lei , Wu Xiaohao , Lin Sixiong , Chen Sheng , Lai Yumei , Zou Xuenong , Shao Zengwu , Wang Meiqing , Chen Di , Jin Wenfei , Song Youqiang , Cao Huiling , Zhang Ge , Xiao Guozhi
Published: December 2020

In vertebrates, the type 1 parathyroid hormone receptor (PTH1R) is a critical regulator of skeletal development and homeostasis; however, how it is modulated is incompletely understood. Here we report that deleting Kindlin-2 in osteoblastic cells using the mouse 10-kb Dmp1-Cre largely neutralizes the intermittent PTH-stimulated increasing of bone volume fraction and bone mineral density by impairing both osteoblast and osteoclast formation in murine adult bone. Single-cell profiling reveals that Kindlin-2 loss increases the proportion of osteoblasts, but not mesenchymal stem cells, chondrocytes and fibroblasts, in non-hematopoietic bone marrow cells, with concomitant depletion of osteoblasts on the bone surfaces, especially those stimulated by PTH. Furthermore, haploinsufficiency of Kindlin-2 and Pth1r genes, but not that of either gene, in mice significantly decreases basal and, to a larger extent, PTH-stimulated bone mass, supporting the notion that both factors function in the same genetic pathway. Mechanistically, Kindlin-2 interacts with the C-terminal cytoplasmic domain of PTH1R via aa 474–475 and Gsα. Kindlin-2 loss suppresses PTH induction of cAMP production and CREB phosphorylation in cultured osteoblasts and in bone. Interestingly, PTH promotes Kindlin-2 expression in vitro and in vivo, thus creating a positive feedback regulatory loop. Finally, estrogen deficiency induced by ovariectomy drastically decreases expression of Kindlin-2 protein in osteocytes embedded in the bone matrix and Kindlin-2 loss essentially abolishes the PTH anabolic activity in bone in ovariectomized mice. Thus, we demonstrate that Kindlin-2 functions as an intrinsic component of the PTH1R signaling pathway in osteoblastic cells to regulate bone mass accrual and homeostasis.
CircRNA-SORE mediates sorafenib resistance in hepatocellular carcinoma by stabilizing YBX1
Authors: Xu Junjie , Ji Lin , Liang Yuelong , Wan Zhe , Zheng Wei , Song Xiaomin , Gorshkov Kirill , Sun Qiming , Lin Hui , Zheng Xueyong , Chen Jiang , Jin Ren-an , Liang Xiao , Cai Xiujun
Published: December 2020

Sorafenib is the first-line chemotherapeutic therapy for advanced hepatocellular carcinoma (HCC). However, sorafenib resistance significantly limits its therapeutic efficacy, and the mechanisms underlying resistance have not been fully clarified. Here we report that a circular RNA, circRNA-SORE (a circular RNA upregulated in sorafenib-resistant HCC cells), plays a significant role in sorafenib resistance in HCC. We found that circRNA-SORE is upregulated in sorafenib-resistant HCC cells and depletion of circRNA-SORE substantially increases the cell-killing ability of sorafenib. Further studies revealed that circRNA-SORE binds the master oncogenic protein YBX1 in the cytoplasm, which prevents YBX1 nuclear interaction with the E3 ubiquitin ligase PRP19 and thus blocks PRP19-mediated YBX1 degradation. Moreover, our in vitro and in vivo results suggest that circRNA-SORE is transported by exosomes to spread sorafenib resistance among HCC cells. Using different HCC mouse models, we demonstrated that silencing circRNA-SORE by injection of siRNA could substantially overcome sorafenib resistance. Our study provides a proof-of-concept demonstration for a potential strategy to overcome sorafenib resistance in HCC patients by targeting circRNA-SORE or YBX1.
Skillfully collaborating chemosynthesis with GOx-enabled tumor survival microenvironment deteriorating strategy for amplified chemotherapy and enhanced tumor ablation
Authors: Lu Runxin , Zhou Lin , Liu Qijun , Wang Siqi , Yang Chunyan , Hai Li , Guo Li , Wu Yong
Published: December 2020

The chemosynthetic approach was skillfully combined with a GOx-enabled tumor survival microenvironment deteriorating strategy to achieve secure and satisfactory tumor ablation through multimodal synergistic starvation/oxidation/chemotherapy.
Dual-emitting piezofluorochromic dye@MOF for white-light generation
Authors: Li Meiling , Ren Guojian , Yang Weiting , Yang Yonghang , Yang Weikang , Gao Yan , Qiu Pengfei , Pan Qinhe
Published: December 2020

HNU-49 exhibits interesting piezofluorochromic behavior and the luminescence reversibly changes from blue to green. It can encapsulate RhB successfully, and near white-light emission can be obtained by precisely controlling the concentration of RhB and the pressure used.
Modulating alkene reactivity from oxygenation to halogenation via electrochemical O2 activation by Mn porphyrin
Authors: Kostopoulos Nikolaos , Banse Frédéric , Fave Claire , Anxolabéhère-Mallart Elodie
Published: December 2020

Modulating alkene reactivity from oxygenation to halogenation with an exogenous ligand via O2 electrochemical reductive activation.
Gold(i) ethylene complexes supported by electron-rich scorpionates
Authors: Wu Jiang , Noonikara-Poyil Anurag , Muñoz-Castro Alvaro , Dias H. V. Rasika
Published: December 2020

“Bottle-able” molecules with gold–ethylene bonds have been obtained using electron-rich scorpionates. Resulting molecules display enhanced gold → ethylene backbonding, and properties different from those involving electron-poor scorpionates.
ZnAlMCM-41: a very ecofriendly and reusable solid acid catalyst for the highly selective synthesis of 1,3-dioxanes by the Prins cyclization of olefins
Authors: Selvaraj Manickam , Assiri Mohammed A. , Singh Hari , Appaturi Jimmy Nelson , Subrahmanyam Ch. , Ha Chang-Sik
Published: December 2020

A very ecofriendly, highly active and reusable mesostructured ZnAlMCM-41(75) catalyst used in the Prins cyclization of olefins has unprecedented catalytic activity among other microporous and mesoporous catalysts.
Aloin protects mice from diet-induced non-alcoholic steatohepatitis via activation of Nrf2/HO-1 signaling
Authors: Xu Qiushi , Fan Yunhui , Loor Juan J. , Liang Yusheng , Lv Hongming , Sun Xudong , Jia Hongdou , Xu Chuang
Published: December 2020

Aloin, a naturally occurring anthraquinone glycoside derived from the Aloe species, has antioxidant and anti-inflammatory activities, but its role in non-alcoholic steatohepatitis (NASH) remains unknown.
A review on the cytotoxicity of graphene quantum dots: from experiment to simulation
Authors: Liang Lijun , Peng Xiangming , Sun Fangfang , Kong Zhe , Shen Jia-Wei
Published: December 2020

Schemetic diagram of the mechanism of GQD-induced cytotoxicity.
Fluorescence quenching mechanism and the application of green carbon nanodots in the detection of heavy metal ions: a review
Authors: Sekar Anithadevi , Yadav Rakhi , Basavaraj Nivetha
Published: December 2020

This review article highlights the quenching mechanism and applications of green CNDs for the detection of metal ions.
ZIF-8 calcination derived Cu2O–ZnO* material for enhanced visible-light photocatalytic performance
Authors: Yin Yilin , Liu Jingchao , Wu Zengnan , Zhang Ting , Li Zenghe
Published: December 2020

The mechanism of TC degradation over Cu2O–ZnO* rich in oxygen vacancies.
The synthesis, characterization, and theoretical analysis of (NH4)3PbCl5
Authors: Zhu Liang , Jin Wenqi , Yang Zhihua , Yang Yun , Pan Shilie
Published: December 2020

(NH4)3PbCl5 features a 3D structure with a short UV cutoff edge of 256 nm and simulated birefringence of about 0.050 at 1064 nm.
Unravelling the shell growth pathways of Au–Ag core–shell nanoparticles by in situ liquid cell transmission electron microscopy
Authors: Wei Wei , Bai Tingting , Fu Ruining , Sun Litao , Wang Wen , Dong Meng , Chen Lei , Guo Zhirui , Xu Feng
Published: December 2020

The growth mode of the Ag shell switches from atom deposition to nuclei coalescence upon addition of PVP.
Peptoid-directed assembly of CdSe nanoparticles
Authors: Monahan Madison , Cai Bin , Jian Tengyue , Zhang Shuai , Zhu Guomin , Chen Chun-Long , De Yoreo James J. , Cossairt Brandi M.
Published: December 2020

Pre-assembled peptoid tubes and sheets are used as a generalizable platform to template the assembly of controllable densities of CdSe quantum dots and clusters through a robust, covalent linkage.
Emulation of biphasic plasticity in retinal electrical synapses for light-adaptive pattern pre-processing
Authors: Wu Lindong , Wang Zongwei , Wang Bowen , Chen Qingyu , Bao Lin , Yu Zhizhen , Yang Yunfan , Ling Yaotian , Qin Yabo , Tang Kechao , Cai Yimao , Huang Ru
Published: December 2020

This work demonstrates the emulation of biphasic plasticity in the electrical synapses by integrating the Ag-based memristor with a photosensitive element to form an optical pre-processing unit (OPU).
Highly sensitive detection of caspase-3 activity based on peptide-modified organic electrochemical transistor biosensors
Authors: Yu Ji , Yang Anneng , Wang Naixiang , Ling Haifeng , Song Jiajun , Chen Xi , Lian Yadong , Zhang Zhishan , Yan Feng , Gu Min
Published: December 2020

Organic electrochemical transistors are successfully used in the detection of caspase-3, and the detection limit is 0.1 pM.
Conformation-dependent charge transport through short peptides
Authors: Stefani Davide , Guo Cunlan , Ornago Luca , Cabosart Damien , El Abbassi Maria , Sheves Mordechai , Cahen David , van der Zant Herre S. J.
Published: December 2020

Machine-learning analyses enable identifying signatures of peptide conformers in single molecule electron transport experiments.
Reproducibility in the unfolding process of protein induced by an external electric field
Authors: Sinelnikova Anna , Mandl Thomas , Östlin Christofer , Grånäs Oscar , Brodmerkel Maxim N. , Marklund Erik G. , Caleman Carl
Published: December 2020

Controlled unfolding of proteins can reveal structural properties and give insights of the proteins' dynamics. We show the feasibility of unfolding proteins in the gas phase using electric fields, with a well-defined path at high field strengths.
Dual-functioning porous catalysts: robust electro-oxidation of small organic molecules and water electrolysis using bimetallic Ni/Cu foams
Authors: Rizk Mohamed R. , Abd El-Moghny Muhammad G. , Mazhar Amina , El-Deab Mohamed S. , El-Anadouli B. E.
Published: December 2020

The simultaneous co-deposition of Cu within the matrix of Ni foams (utilizing DHBT) increases their intrinsic catalytic activity towards water electrolysis, urea oxidation reaction (UOR), and glycerol oxidation reaction (GOR) in alkaline media.
Cationic surfactant assisted enhancement of dielectric and piezoelectric properties of PVDF nanofibers for energy harvesting application
Authors: Ekbote Govind S. , Khalifa Mohammed , Mahendran Arunjunairaj , Anandhan S.
Published: December 2020

A cationic surfactant (tetra-n-butyl ammonium chloride) incorporated into electrospun PVDF enhanced the β-phase of PVDF and thereby the piezoelectric response of the nanogenerator based on it.
Changing polymer catechol content to generate adhesives for high versus low energy surfaces
Authors: Putnam Amelia A. , Wilker Jonathan J.
Published: December 2020

Changing catechol content in a biomimetic polymer alters affinity for high versus low surface energy substrates.
IFN-γ/SrBG composite scaffolds promote osteogenesis by sequential regulation of macrophages from M1 to M2
Authors: Luo Man , Zhao Fujian , Liu Lu , Yang Zhen , Tian Ting , Chen Xiaoyu , Cao Xiaodong , Chen Dafu , Chen Xiaofeng
Published: December 2020

The macrophage-dominated bone immune response plays an important role in osteogenesis of bone defects.
I‐HPO‐CDSK: An improved chaotic communication scheme for high reliability and effectivity
Authors: Duan Jun‐Yi , Yang Hua
Published: December 2020

By transmitting 2‐bits orthogonal information signal in parallel, compared with phase‐orthogonality CDSK (PO‐CDSK), high‐data‐rate PO‐CDSK (HPO‐CDSK) has double spectral efficiency. Unfortunately, the additional information will cause more noise interference during correlation detection in HPO‐CDSK. The study of HPO‐CDSK is extended and improved HPO‐CDSK (I‐HPO‐CDSK) is proposed to obtain high reliability and effectiveness. By virtue of the theorem that the integral of the sine and cosine functions in a period is 0, in I‐HPO‐CDSK, 3‐bits information can be transmitted in parallel and will not cause ISI components. Moreover, compared with HPO‐CDSK, I‐HPO‐CDSK can decrease noise interference. Results show that, due to less interference and 3‐bits information transmitting in parallel, I‐HPO‐CDSK has better BER performance and spectral efficiency than those of previous chaotic communication schemes, such as PO‐CDSK and HPO‐CDSK.
Channel estimation using variational Bayesian learning for multi‐user mmWave MIMO systems
Authors: Xiao Bo , Huang Pingmu , Lin Zhipeng , Zeng Jie , Lv Tiejun
Published: December 2020

This paper presents a novel variational Bayesian learning‐based channel estimation scheme for hybrid pre‐coding‐employed wideband multiuser millimetre wave multiple‐input multiple‐output communication systems. We first propose a frequency variational Bayesian algorithm, which leverages common sparsity of different sub‐carriers in the frequency domain. The algorithm shares all the information of the support sets from the measurement matrices, significantly improving channel estimation accuracy. To enhance robustness of the frequency variational Bayesian algorithm, we develop a hierarchical Gaussian prior channel model, which employs an identify‐and‐reject strategy to deal with random outliers imposed by hardware impairments. A support selection frequency variational Bayesian channel estimation algorithm is also proposed, which adaptively selects support sets from the measurement matrices. As a result, the overall computational complexity can be reduced. Validated by the Bayesian Cramér‐Rao bound, simulation results show that, both frequency variational Bayesian and support selection‐frequency variational Bayesian algorithms can achieve higher channel estimation accuracy than existing methods. Furthermore, compared with frequency variational Bayesian, support selection‐frequency variational Bayesian requires significantly lower computational complexity, and hence, it is more practical for channel estimation applications.
A novel non‐unit protection scheme for HVDC transmission lines based on multi‐resolution morphology gradient
Authors: Raghpoor Vahid , Mehrabi‐Kooshki Mohammad , Razzaghi Reza
Published: December 2020

This paper presents a novel non‐unit protection scheme for the protection of LCC‐HVDC transmission lines. The fault‐generated travelling waves at the faulty line ends are filtered by a filter–reactor unit. The filtered current waveforms are then processed by a multi‐resolution morphological gradient and are used by a fast non‐unit protection scheme for LCC‐HVDC transmission lines. The proposed method does not require communication links between transmission line ends and uses only current signals with a low sampling rate of 10 kHz. In addition, the proposed scheme is computationally efficient, making it suitable for practical applications. The performance of the proposed protection scheme is validated by comprehensive simulation studies as well as field data on a bipolar LCC‐HVDC system. Both simulation and field data test results verify the accurate performance of the proposed method for different internal fault conditions, including high fault resistances up to 1000 Ω. Furthermore, the proposed scheme is robust against external DC and AC faults, change of sampling frequency and data window length, non‐ideal faults, change of power flow, change of DC filter parameters and smoothing reactor, change of operation mode, and measurement noise.
Deep residual deconvolutional networks for defocus blur detection
Authors: Zeng Kai , Wang Yaonan , Mao Jianxu , Zhou Xianen
Published: December 2020

Accurate defocus blur detection has instigated wide research interest for the last few years. However, it is still a meaningful yet challenging machine vision task, and most methods rely on prior knowledge. Convolutional neural networks have proved the huge success for different tasks within the computer vision, and machine learning flew. A simple yet effective method of defocus blur detection was proposed in this paper, which by applying the deep residual convolutional encoder‐decoder network. The aims of DRDN is to automatically generate pixel‐level predictions for defocus blur images, and reconstruct output detection results of the same size as the input, which by performing several deconvolution operations at multiple scales through the transposed convolution, and skip connection. Afterwards, we used the slide window detection strategy and traversed the input image with a certain stride. Experiments on challenging benchmarks of defocus blur detection show that our algorithm achieved state‐of‐the‐art performance, and powerfully balanced the detection accuracy, and detection time.
Finger vein recognition algorithm under reduced field of view
Authors: Jin Jian , Di Si , Li Weijian , Sun Xuetong , Wang Xudi
Published: December 2020

Algorithms for finger vein recognition methods are generally designed based on greyscale images containing vein distributions, but greyscale inhomogeneities and non‐venous texture structures often adversely affect the recognition results. Besides, the performance of the algorithm when the field of view is reduced has not been studied. Therefore, the aim of this paper is to propose an algorithm based on binary image, so as to minimize the interference of non‐venous factors in the identification process. We use the feature from accelerated segment test algorithm to detect feature points, and use gradient histogram to describe these feature points in a vectorized manner. In addition, we propose the concept of circular matching neighbourhood, and select the matching feature point pairs in this area. Then, the Euclidean distance and the number of correct matching pairs were comprehensively considered to increase the recognition rate of the algorithm. The algorithm was tested on the database of SDU‐MLA, FV‐USM and MMCBNU‐6000. The results show that the algorithm has certain advantages before and after the field of view is reduced. Therefore, this paper not only provides a new idea for finger vein recognition, but also has practical application value for the miniaturization of finger vein acquisition devices.
An improved symbol reduction technique based Huffman coder for efficient entropy coding in the transform coders
Authors: Thakur Vikrant Singh , Thakur Kavita , Gupta Shubhrata
Published: December 2020

Entropy coding is the essential block of transform coders that losslessly converts the quantized transform coefficients into the bit‐stream suitable for transmission or storage. Usually, the entropy coders exhibit less compression capability than the lossy coding techniques. Hence, in the past decade, several efforts have been made to improve the compression capability of the entropy coding technique. Recently, a symbol reduction technique (SRT) based Huffman coder is developed to achieve higher compression than the existing entropy coders at similar complexity of the regular Huffman coder. However, the SRT‐based Huffman coding is not popular for the real‐time applications due to the improper negative symbol handling and the additional indexing issues, which restrict its compression gain at most 10–20% over the regular Huffman coder. Hence, in this paper, an improved SRT (ISRT) based Huffman coder is proposed to properly alleviate the deficiencies of the recent SRT‐based Huffman coder and to achieve higher compression gains. The proposed entropy coder is extensively evaluated on the ground of compression gain and the time complexity. The results show that the proposed ISRT‐based Huffman coder provides significant compression gain against the existing entropy coders with lower time consumptions.
A level‐set method for inhomogeneous image segmentation with application to breast thermography images
Authors: Shamsi Koshki Asma , Ahmadzadeh M.R. , Zekri M. , Sadri S. , Mahmoudzadeh E.
Published: December 2020

Various level‐set methods have been suggested for segmenting images with intensity inhomogeneity as local region‐based models. The challenge in these methods is segmenting the inhomogeneous images with smooth edges. These methods cannot properly segment regions with smooth edges in inhomogeneous images. This paper presents a new local region‐based active contour model called local self‐weighted active contour model. In the proposed method, a novel different weighting technique is applied. In this model, the weight of each neighbour pixel in the energy function is set by a function of its intensity and not its geometrical distance regarding the central pixel as previous methods. Considering this, the presented approach can segment regions with smooth edges in the presence of inhomogeneity as breast thermography images. The experimental results of applying the model on heterogeneous images containing synthetic images and medical images, especially breast thermography images, are compared with well‐known local level‐set methods which show the perfect capability of the model. The segmentation results were evaluated using the F‐score, accuracy, precision and recall criteria. The results show values of 0.8, 0.62, 0.73 and 0.82 for the average accuracy, F‐score, precision and recall criteria on the segmentation of breast thermography images, respectively.
Tissue Modification in Nonsurgical Facelift Options
Authors: Harrison Lucas M. , Shapiro Ryan , Johnson R Michael
Published: December 2020

Nonsurgical facelifts are a term for a heterogeneous group of procedures used by physicians to improve facial rejuvenation without the use of operative techniques. Patients demand these services due to the reduced recovery time and generally lower risk. However, nonsurgical techniques, to be effective, must induce conformational change in the cells and tissues of the face. Therefore, these techniques are significant procedures that have associated risks. Understanding the tissue modifications and mechanisms of action of these techniques is vital to their safe and effective use. The purpose of this article is to provide a background of tissue modification in nonsurgical facelift options.
Effect of Carbonate Apatite Hydrogel-Advanced Platelet-Rich Fibrin Injection on Osteoblastogenesis during Orthodontic Relapse in Rabbits
Authors: Alhasyimi Ananto Ali , Suparwitri Sri , Christnawati Christnawati
Published: December 2020

Objective This study aimed to determine the effect of carbonate apatite (CHA) hydrogel-aPRF on osteoblastogenesis during relapse in rabbits.

Materials and Methods Forty-five rabbits were divided into three groups (n = 15): the control, CHA, and CHA-autologous platelet-rich fibrin (aPRF) groups. An open-coil spring was compressed between brackets to distalize the lower incisors of the rabbits by delivering a force of 50 cN for 1 week. The new position of the teeth was retained for 14 days, and CHA hydrogel-aPRF was injected every 7 days. The appliances were then debonded to allow relapse. On days 0, 3, 7, 14, and 21 after debonding, transforming growth factor (TGF)-β1 and bone morphogenetic protein (BMP)-2 expression was examined using immunohistochemistry staining and Runx-2 levels were analyzed by enzyme-linked immunosorbent assay. The data collected were analyzed using analysis of variance and a post hoc Tukey’s test (p < 0.05).

Results Histomorphometric analysis revealed that TGF-β1 expression in the CHA-aPRF group is statistically higher than that in other groups on days 0, 3, and 7 after debonding (p < 0.05). BMP-2 expression in the CHA-aPRF group was also statistically higher than that in the other groups on days 3, 14, and 21 after debonding (p < 0.05). ELISA showed that Runx-2 levels are slightly higher in the CHA-aPRF group than in the other groups (p > 0.05).

Conclusion Although injection of CHA-aPRF aids in osteoblastogenesis associated with enhancing TGF-β1 and BMP-2 expressions, it does not significantly upregulate Runx-2 levels.