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Betulin protects against isoproterenol-induced myocardial injury by inhibiting NF-κB signaling and attenuating cardiac inflammation and oxidative stress in rats

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Asian Pacific Journal of Tropical Biomedicine 2024年第6期14卷 236-244页

作者： Hital Shah Tejal Gandhi Gujarat technological University AhmedabadGujarat 382424India department of Pharmacology Anand Pharmacy CollegeAnandGujarat 388001India

Objective:To investigate the cardioprotective potential of betulin in isoproterenol(ISO)-induced myocardial injury in ***:Wistar rats were divided into five groups(n=10):normal,ISO,nebivolol 5 mg/kg,and betulin(20&40 mg/kg).Nebivolol and betulin were administered orally for 29 ***(85 mg/kg)was administered subcutaneously on day 27 and day 28 to induce myocardial *** day 29,blood was collected for determination of cardiac markers,and hemodynamic parameters were *** levels of oxidative stress markers and the gene expressions of apoptotic markers and inflammatory mediators were ***,2,3,5-triphenyltetrazolium chloride staining and histopathological analysis were also ***:Betulin reduced the size of myocardial infarction,decreased elevated levels of cardiac enzymes,and maintained hemodynamic *** also inhibited ISO-induced upregulation of Bax,caspase-3,NF-κB,and IL-6,enhanced endogenous antioxidant enzymes,and reduced lipid ***,pretreatment with betulin alleviated myocardial ischemic damage,as reflected by reduced myonecrosis,edema,and inflammatory ***:Betulin exhibits strong cardioprotective activity against ISO-induced myocardial injury by anti-inflammatory,anti-apoptotic,and antioxidant activities.

关键词： NF-κB Isoproterenol Betulin Myocardial injury Oxidative stress Inflammation Apoptosis

Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David J.Bottjer department of Earth sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Heterogeneous integration of 2D materials on Si charge-coupled devices as optical memory

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Science China(Information sciences) 2024年第6期67卷 190-197页

作者： Zheng BIAN Feng TIAN Zongwen LI Xiangwei SU Tianjiao ZHANG Jialei MIAO Bin YU Yang XU Yuda ZHAO College of Integrated Circuits Hangzhou Global Scientific and Technological Innovation CentreZhejiang University

Optical memory integrates the function of optical sensing in memory devices, remarkably promoting the interconnection between sensory and memory terminals. Silicon charge-coupled photodetectors and floating gate memory have been widely used in imaging and storage technologies, respectively. However,the heterogeneous integration of the two devices requires technological innovation and complex electrical connections. In this work, we adopt a three-dimensional layer stacking method to design a novel optical memory device. On the top of Si charge-coupled photodetectors, we successively deposit two-dimensional graphene,hexagonal boron nitride, and molybdenum disulfide as a floating gate layer, a tunneling layer, and a readout layer, respectively. By applying a gate bias on lightly doped Si, a deep depletion layer is formed with a high voltage potential drop. Under dark conditions, the depletion layer cannot be filled, and the electric field across the h-BN tunnel barrier is relatively small. Under light irradiation, the deep depletion layer is gradually filled, and the h-BN tunneling layer withstands the increasing electric field, resulting in charge storage in the floating gate layer. Based on this mechanism, the device exhibits a gate voltage-dependent operation mode, including an integrated optical sensing-memory mode and an electrically driven storage mode. Under moderate gate voltage, the device can effectively detect the optical information with varied intensity and store the optical information in the floating gate, displaying optically controlled memory characteristics. Our work demonstrates a compact device structure for optical memory and displays excellent optically controlled memory performance, which can be applied in artificial vision systems.

关键词： heterogeneous integration charge-coupled device floating gate optical memory molybdenum disulfide lightly doped silicon

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Electron push-pull effects induced performance promotion in covalent organic polymer thin films-based memristor for neuromorphic application

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Chinese Chemical Letters 2024年第5期35卷 227-231页

作者： Panke Zhou Hong Yu Mun Yin Chee Tao Zeng Tianli Jin Hongling Yu Shuo Wu Wen Siang Lew Xiong Chen State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou UniversityFuzhou 350116China School of Physical and Mathematical sciences Nanyang Technological UniversitySingapore 637371Singapore department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore

Covalent organic polymer(COP)thin film-based memristors have generated intensive research interest,but the studies are still in their ***,by controlling the content of hydroxyl groups in the aldehyde monomer,Py-COP thin films with different electronic push-pull effects were fabricated bearing distinct memory performances,where the films were prepared by the solid-liquid interface method on the ITO substrates and further fabricated as memory devices with ITO/Py-COPs/Ag *** Py-COP-1-based memory device only exhibited binary memory behavior with an ON/OFF ratio of 1:10^(1.87).In contrast,the device based on Py-COP-2 demonstrated ternary memory behavior with an ON/OFF ratio of 1:10^(0.6):10^(3.1) and a ternary yield of 55%.The ternary memory mechanism of the ITO/Py-COP-2/Ag memory device is most likely due to the combination of the trapping of charge carriers and conductive ***,the Py-COPs-based devices can successfully emulate the synaptic potentiation/depression behavior,clarifying the programmability of these devices in neuromorphic *** results suggest that the electronic properties of COPs can be precisely tuned at the molecular level,which provides a promising route for designing multi-level memory devices.

关键词： Covalent organic polymers Push-pull effects Multi-level memory Memristor

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New findings on the influence of El Nino events on tropical cyclone formation

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Science China Earth sciences 2024年第3期67卷 892-893页

作者： Liguang WU department of Atmospheric and Oceanic sciences Institute of Atmospheric SciencesFudan UniversityShanghai 200438China

Tropical cyclones typically form over warm tropical and subtropical ocean surfaces, as their formation and intensification rely primarily on the energy provided by the ocean. Pioneering research by Gray (1968) revealed that the formation of tropical cyclones requires the sea surface temperature (SST) to be no less than 26.5℃. Consequently, SST is commonly recognized as a crucial parameter among the environmental factors influencing tropical cyclone formation(Gray, 1979;Emanuel and Nolan, 2004).

关键词： tropical cyclone ocean

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Low profile cavity-embedded ultra-wideband UHF array antenna with end-fire beams

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Journal of Electronic Science and Technology 2024年第2期22卷 24-35页

作者： Huan He Wen-Song Wang Southwest China Institute of Electronic Technology Chengdu610036China School of Electrical and Electronic Engineering department Nanyang Technological UniversitySingapore639798Singapore

A low-profile,vertically polarized,ultra-wideband array antenna with end-fire beams operating in an ultra-high frequency(UHF)band is developed in this *** array antenna consists of 1×16 log-periodic top-hat loaded monopole antenna arrays and is feasible to embed into a shallow cavity to further reduce the array *** is introduced in the proposed antenna element to reduce profile height and the rectangular top hats are carefully designed to minimize the transverse *** results show that when the antenna array operates in a frequency range of 300 MHz-900 MHz,the end-fire radiation pattern achieves±45°scanning range in the horizontal *** prototypes of the proposed end-fire antenna element and a uniformly spaced linear array(1×2)are fabricated and *** end-fire antenna array should be suitable for airborne applications where low-profile and conformal scanning phased antenna arrays with end-fire radiations are *** design is attractive for airborne platform applications that are used to search,discover,identify,and scout the aerial target with vertically polarized beams.

关键词： End-fire radiation Low-profile Vertical polarization Log-periodic array

Non-thermal atmospheric-pressure positive pulsating corona discharge in degradation of textile dye Reactive Blue 19 enhanced by Bi_(2)O_(3) catalyst

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Plasma Science and Technology 2024年第2期26卷 104-113页

作者： Milica PETROVIC Dragan RADIVOJEVIC Sasa RANCEV Nena VELINOV Milos KOSTIC Danijela BOJIC Aleksandar BOJIC department of Chemistry Faculty of Sciences and MathematicsUniversity of NisNis 18000Serbia department of Physics Faculty of Sciences and MathematicsUniversity of NisNis 18000Serbia

In this work,monoclinic Bi_(2)O_(3) was applied for the first time,to the best of our knowledge,as a catalyst in the process of dye degradation by a non-thermal atmospheric-pressure positive pulsating corona *** research focused on the interaction of the plasma-generated species and the catalyst,as well as the role of the catalyst in the degradation *** decomposition of the anthraquinone reactive dye Reactive Blue 19(RB 19) was performed in a selfmade reactor ***_(2)O_(3) was prepared by electrodeposition followed by thermal treatment,and characterized by x-ray diffraction,scanning electron microscopy and energy-dispersive xray *** was observed that the catalyst promoted decomposition of plasma-generated H_(2)O_(2) into ·OH radicals,the principal dye-degrading reagent,which further attacked the dye *** catalyst improved the decolorization rate by 2.5 times,the energy yield by 93.4%and total organic carbon removal by 7.1%.Excitation of the catalyst mostly occurred through strikes by plasma-generated reactive ions and radical species from the air,accelerated by the electric field,as well as by fast electrons with an energy of up to 15 eV generated by the streamers reaching the liquid *** strikes transferred the energy to the catalyst and created the electrons and holes,which further reacted with H_(2)O_(2) and water,producing ·OH *** was indentified as the primary role of the catalyst in this *** reactions followed pseudo first-order *** of H_(2)O_(2) and the dye degradation rate increased with increase in the input *** optimal catalyst dose was 500 mg·dm^(-3).The decolorization rate was a little lower in river water compared with that in deionized water due to the side reactions of ·OH radicals with organic matter and inorganic ions dissolved in the river water.

关键词： corona RB 19 Bi_(2)O_(3) catalyst degradation

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Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： S.W.Wi Y.S.Lee department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence Sensitizer Rare earths