Secreted Frizzled-Related Protein 5 Mediates Wnt5a Expression in Microcystin-Leucine-Arginine-Induced Liver Lipid Metabolism Disorder in Mice

Objective Microcystin-leucine-arginine(MC-LR)exposure induces lipid metabolism disorders in the liver.Secreted frizzled-related protein 5(SFRP5)is a natural antagonist of winglesstype MMTV integration site family,member 5A(Wnt5a)and an anti-inflammatory adipocytokine.In this study,we aimed to investigate whether MC-LR can induce lipid metabolism disorders in hepatocytes and whether SFRP5,which has anti-inflammatory effects,can alleviate the effects of hepatic lipid metabolism by inhibiting the Wnt5a/Jun N-terminal kinase(JNK)pathway.Methods We exposed mice to MC-LR in vivo to induce liver lipid metabolism disorders.Subsequently,mouse hepatocytes that overexpressed SFRP5 or did not express SFRP5 were exposed to MC-LR,and the effects of SFRP5 overexpression on inflammation and Wnt5a/JNK activation by MC-LR were observed.Results MC-LR exposure induced liver lipid metabolism disorders in mice and significantly decreased SFRP5 mRNA and protein levels in a concentration-dependent manner.SFRP5 overexpression in AML12cells suppressed MC-LR-induced inflammation.Overexpression of SFRP5 also inhibited Wnt5a and phosphorylation of JNK.Conclusion MC-LR can induce lipid metabolism disorders in mice,and SFRP5 can attenuate lipid metabolism disorders in the mouse liver by inhibiting Wnt5a/JNK signaling.

Photocatalytic Synthesis of High-Energy-Density Fuel:Catalysts,Mechanisms,and Challenges

High-energy-density liquid hydrocarbon fuels are generally synthesized using various chemical reactions to improve the performance(e.g.,range,load,speed)of aerospace vehicles.Compared with conventional fuels,such as aviation kerosene and rocket kerosene,these liquid hydrocarbon fuels possess the advantages of high-energy-density and high volumetric calorifi c value;therefore,the fuels have important application value.The photocatalytic process has shown great potential for the synthesis of a diverse range of fuels on account of its unique properties,which include good effi ciency,clean atomic economy,and low energy consumption.These characteristics have led to the emergence of the photocatalytic process as a promising complement and alternative to traditional thermocatalytic reactions for fuel synthesis.Extensive eff ort has been made toward the construction of catalysts for the multiple photocatalytic syntheses of high-energy-density fuels.In this review,we aim to summarize the research progress on the photocatalytic synthesis of high-energy-density fuel by using homogeneous and heterogeneous catalytic reactions.Specifi cally,the synthesis routes,catalysts,mechanistic features,and future challenges for the photocatalytic synthesis of high-energy-density fuel are described in detail.The highlights of this review not only promote the development of the photocatalytic synthesis of high-energy-density fuel but also expand the applications of photocatalysis to other fi elds.

基于金属织物和自然摩擦带电的电子皮肤对人体运动的智能识别

目前已开发出各种基于电子或光学信号的技术来感知身体运动,这在医疗保健、康复和人机交互等领域至关重要.然而,这些信号都是从身体外部获取的.本研究中,我们制备了一种电子皮肤(e-skin)人体运动传感器,它利用有机聚合物和金属织物的组合,通过人体的自然电荷感应(EI)来检测运动.该电子皮肤可获得高达450 V的人体电势信号.此外,该信号可通过最先进的深度学习技术自动提取和训练.该传感器能准确识别睡眠活动,准确率约为96.55%.这种可穿戴运动传感器可以与物联网技术无缝集成,实现多功能应用,展示了其在人类活动识别和人工智能方面的潜在用途.

HIF-1αpromotes virus replication and cytokine storm in H1N1 virus-induced severe pneumonia through cellular metabolic reprogramming

The mortality of patients with severe pneumonia caused by H1N1 infection is closely related to viral replication and cytokine storm.However,the specific mechanisms triggering virus replication and cytokine storm are still not fully elucidated.Here,we identified hypoxia inducible factor-1α(HIF-1α)as one of the major host molecules that facilitates H1N1 virus replication followed by cytokine storm in alveolar epithelial cells.Specifically,HIF-1αprotein expression is upregulated after H1N1 infection.Deficiency of HIF-1αattenuates pulmonary injury,viral replication and cytokine storm in vivo.In addition,viral replication and cytokine storm were inhibited after HIF-1αknockdown in vitro.Mechanistically,the invasion of H1N1 virus into alveolar epithelial cells leads to a shift in glucose metabolism to glycolysis,with rapid production of ATP and lactate.Inhibition of glycolysis significantly suppresses viral replication and inflammatory responses.Further analysis revealed that H1N1-induced HIF-1αcan promote the expression of hexokinase 2(HK2),the key enzyme of glycolysis,and then not only provide energy for the rapid replication of H1N1 virus but also produce lactate,which reduces the accumulation of the MAVS/RIG-I complex and inhibits IFN-α/βproduction.In conclusion,this study demonstrated that the upregulation of HIF-1αby H1N1 infection augments viral replication and cytokine storm by cellular metabolic reprogramming toward glycolysis mainly through upregulation of HK2,providing a theoretical basis for finding potential targets for the treatment of severe pneumonia caused by H1N1 infection.

Advances and challenges in semantic communications:A systematic review

Inspired by the recent success of machine learning(ML),the concept of semantic communication introduced by Weaver in 1949 has gained significant attention and has become a promising research direction.Unlike conventional communication systems,semantic communication emphasizes the precise retrieval of conveyed meaning from the source to the receiver,rather than focusing on the accurate transmission of symbols.Thus,semantic communication can achieve a significant gain in source data compression,alleviate communication bandwidth pressure,and support new intelligent services,which is envisioned as a crucial enabler of future sixth-generation(6G)networks.In this review,we critically summarize the advances made in semantic information and semantic communications,including theory,architecture,and potential applications.Moreover,we deeply explore the major challenges in developing semantic communications and present the development prospects,aiming to prompt further scientific and industrial advances in semantic communications.

Influenza A Virus(H1N1) Infection Induces Glycolysis to Facilitate Viral Replication

Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus(H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial(A549) cells. In detail, the expression of hexokinase 2(HK2), the first enzyme in glycolysis, was upregulated in H1N1-infected A549 cells,and the expression of pyruvate kinase M2(PKM2) and pyruvate dehydrogenase kinase 3(PDK3) was upregulated in H1N1-infected mouse lung tissues. Pharmacologically inhibiting the glycolytic pathway or targeting hypoxia-inducible factor 1(HIF-1), the central transcriptional factor critical for glycolysis, significantly reduced H1N1 replication, revealing a requirement for glycolysis during H1N1 infection. In addition, pharmacologically enhancing the glycolytic pathway further promoted H1N1 replication. Furthermore, the change of H1N1 replication upon glycolysis inhibition or enhancement was independent of interferon signaling. Taken together, these findings suggest that influenza A virus induces the glycolytic pathway and thus facilitates efficient viral replication. This study raises the possibility that metabolic inhibitors, such as those that target glycolysis, could be used to treat influenza A virus infection in the future.

High-Q microresonators on 4H-silicon-carbide-on-insulator platform for nonlinear photonics

The realization of high-quality(Q)resonators regardless of the underpinning material platforms has been a ceaseless pursuit,because the high-Q resonators provide an extreme environment for confining light to enable observations of many nonlinear optical phenomenon with high efficiencies.Here,photonic microresonators with a mean Q factor of 6.75×10^(6)were demonstrated on a 4H-silicon-carbide-on-insulator(4H-SiCOI)platform,as determined by a statistical analysis of tens of resonances.Using these devices,broadband frequency conversions,including second-,third-,and fourth-harmonic generations have been observed.Cascaded Raman lasing has also been demonstrated in our SiC microresonator for the first time,to the best of our knowledge.Meanwhile,by engineering the dispersion properties of the SiC microresonator,we have achieved broadband Kerr frequency combs covering from 1300 to 1700nm.Our demonstration represents a significant milestone in the development of SiC photonic integrated devices.

Soliton formation and spectral translation into visible on CMOS-compatible 4H-silicon-carbide-oninsulator platform

Recent advancements in integrated soliton microcombs open the route to a wide range of chip-based communication,sensing,and metrology applications.The technology translation from laboratory demonstrations to real-world applications requires the fabrication process of photonics chips to be fully CMOS-compatible,such that the manufacturing can take advantage of the ongoing evolution of semiconductor technology at reduced cost and with high volume.Silicon nitride has become the leading CMOS platform for integrated soliton devices,however,it is an insulator and lacks intrinsic second-order nonlinearity for electro-optic modulation.Other materials have emerged such as AlN,LiNbO_(3),AlGaAs and GaP that exhibit simultaneous second-and third-order nonlinearities.Here,we show that silicon carbide(SiC)--already commercially deployed in nearly ubiquitous electrical power devices such as RF electronics,MOSFET,and MEMS due to its wide bandgap properties,excellent mechanical properties,piezoelectricity and chemical inertia--is a new competitive CMOS-compatible platform for nonlinear photonics.High-quality-factor microresonators(Q=4×10^(6))are fabricated on 4H-SiC-on-insulator thin films,where a single soliton microcomb is generated.In addition,we observe wide spectral translation of chaotic microcombs from near-infrared to visible due to the second-order nonlinearity of SiC.Our work highlights the prospects of SiC for future low-loss integrated nonlinear and quantum photonics that could harness electro-opto-mechanical interactions on a monolithic platform.

Digitally tunable optical delay line based on thinfilm lithium niobate featuring high switching speed and low optical loss

A tunable optical delay line(ODL) featuring high switching speed and low optical loss is highly desirable in many fields. Here, based on the thin-film lithium niobate platform, we demonstrate a digitally tunable on-chip ODL that includes five Mach–Zehnder interferometer optical switches, four flip-chip photodetectors, and four delayline waveguides. The proposed optical switches can achieve a switching speed of 13 ns and an extinction ratio of34.9 dB. Using a modified Euler-bend-based spiral structure, the proposed delay-line waveguide can simultaneously achieve a small footprint and low optical propagation loss. The proposed ODL can provide a maximum delay time of 150 ps with a resolution of 10 ps and feature a maximum insertion loss of 3.4 dB.

Photonic crystal nanobeam cavities based on 4H-silicon carbide on insulator

The 4H-silicon carbide on insulator(4H-SiC0l)has recently emerged as an attractive material platform for integrated photonics due to its excellent quantum and nonlinear optical properties.Here,we experimentally realize one-dimensional photonic crystal nanobeam cavities on the ion-cutting 4H-SiC0l platform.The cavities exhibit quality factors up to 6.1×10^(3)and mode volumes down to 0.63×[λ/n]^(3)in the visible and near-infrared wavelength range.Moreover,by changing the excitation laser power,the fundamental transverse-electric mode can be dynamically tuned by 0.6 nm with a tuning rate of 33.5 pm/mW.The demonstrated devices offer the promise of an appealing microcavity system for interfacing the optically addressable spin defects in 4H-SiC.

Si-based InGaAs photodetectors on heterogeneous integrated substrate

In this paper,InGaAs p-i-n photodetectors(PDs)on an InP/SiO2/Si(InPOI)substrate fabricated by ion-slicing technology are demonstrated and compared with the identical device on a commercial InP substrate.The quality of epitaxial layers on the InPOI substrate is similar to that on the InP substrate.The photo responsivities of both devices measured at 1.55μm are comparable,which are about 0.808-0.828 A W^(-1).Although the dark current of PD on the InPOI substrate is twice as high as that of PD on the InP substrate at 300 K,the peak detectivities of both PDs are comparable.In general,the overall performance of the InPOI-based PD is comparable to the InP-based PD,demonstrating that the ion-slicing technology is a promising route to enable the highquality Si-based InP platform for the full photonic integration on a Si substrate.