A comparative study of the anti-fatigue activity of extracts from different parts of Cistanche tubulosa(Schenk)Wight

Objective:To evaluate the anti-fatigue effects of different extracts from Cistanche tubulosa(Schenk)Wight(C.tubulosa,Rou Cong Rong),focusing on central and exercise-induced fatigue in mice.This study investigated the pharmacological effects of the total oligosaccharides,polysaccharides,and phenylethanoid glycosides(CPhGs)extracted from C.tubulosa.Methods: Models of sleep deprivation and forced swimming fatigue were established to simulate central and exercise-induced fatigue.The mice were treated with different extracts of C.tubulosa,and their effects were assessed using behavioral tests to measure exercise capacity,learning,and memory function.Biochemical analyses were performed to evaluate the changes in serum and brain neurotransmitter levels,liver and muscle glycogen storage,and various fatigue-related biomarkers.Results: This study found that treatment with C.tubulosa extract improved exercise capacity,learning,and memory in mice.Total oligosaccharides from C.tubulosa enhanced adrenocorticotropic hormone,cholinesterase,and thyroid-stimulating hormone levels,reduced cortisol levels in central fatigue models,and ameliorated biochemical markers of exercise-induced fatigue,including lowering lactic acid,blood urea nitrogen,and malondialdehyde levels.Among the tested extracts,the total oligosaccharides showed the most comprehensive anti-fatigue effects.Conclusion: The anti-fatigue effects of C.tubulosa,particularly those of its total oligosaccharides,are pronounced in both central and exercise-induced fatigue.These effects are mediated by the regulation of neurotransmitter levels,enhancement of glycogen storage,and improvement of antioxidant enzyme activity,suggesting potential therapeutic benefits in fatigue-related conditions.

Triplex-structure based DNA circuits with ultra-low leakage and high signal-to-noise ratio

DNA circuits are powerful tools in various applications such as logical computation,molecular diagnosis and synthetic biology.Leakage is a major problem in constructing complex DNA circuits.It directly affects the output signal and harms the circuit’s performance significantly.In the traditional DNA circuits,the gate complex is a duplex structure.There are insufficient energy barriers to prevent spontaneous detachment of strands,resulting in a leak prone.Herein,we have developed triplex-structure based DNA circuit with ultra-low leakage and high signal-to-noise ratio(SNR).The triplex structure improves the stability in the absence of input.At the same time,the driving force of the strand displacement cascades reduces the influence of the triplex structure on the desired reaction.The SNR of the DNA circuit was increased to 695,while the desired reaction rate remained 90%of the conventional translator circuit.The triplex-structure mediated leakage prevention strategy was further tested at different temperatures and in DNA translator and seesaw circuits.We also constructed modular basic logic gates with a high efficiency and low leakage.On this basis,we further constructed triplex-structure based tertiary DNA logic circuits,and the SNR reached 295,which,to the best of our knowledge,was among the highest of the field.We believe that our scheme provides a novel,valid,and general tool for reducing leakages,and we anticipate that it will be widely adopted in DNA nanotechnology.

二维范德华磁体的拓扑自旋结构的研究进展

The importance of topological spin textures(TSTs), such as skyrmions, merons, hopfions, etc., is due to their static and dynamic properties [1]. They carry a topological number that characterizes the homotopy group Π_(n)(S^(2))(n ∈ Z) and classifies maps from S^(n) to S^(2)(e.g., the skyrmion winding number corresponds to Π_(2)(S^(2))).

An Automated,Highly Selective Reaction Monitoring Instrument Using Molecular Rotational Resonance Spectroscopy

Online monitoring of chemical reactions by using analytical chemistry tools is a powerful way to maximize control over these processes.In this paper,we demonstrate the use of molecular rotational resonance,an emerging and extraordinarily selective spectroscopic technique,to perform automated reaction monitoring measurements.An interface using a six-port valve with a calibrated sample loop,coupled to a temperature controlled inlet for analyte volatilization,was developed and tested.Two reactions were chosen for initial characterization:an amine-aldehyde condensation reaction to form an imine product and an isotopic exchange reaction of aβ-ketoester with keto-enol tautomerization.The spectrometer was able to provide kinetic information about the reaction and determine reaction completion.In the future,this system can be extended to detect and quantify impurities and characterize reaction selectivity,in addition to the reaction progress.

大学生法治素养提升路径研究

目前大学生法治素养提升不足,整体体现在校园法治氛围营造不足、学生法律知识基础较差、法治文化保障机制欠缺这三个方面。可以通过对国内外院校的学习和借鉴,吸收和采纳各院校合理培养和提升大学生法治素养的方式。除此以外,对于大学生法治素养提升的路径,主要包括以下几个方面。从转变法治素养教育理念出发,培育学生法治精神。丰富法治素养教育活动形式,营造浓厚法治氛围。完善法治知识宣传体系,构建线上线下一体化平台,让学生多角度接触法治相关知识。健全大学生法治素养教育机制,保障校园法治文化稳定推进。打破法治相关专业与其他专业的壁垒,推进学科融合。融合枫桥经验,将法治教育浸润至学生社区。通过人工智能技术,赋能理工类院校法治教育建设。

Compact 517 MHz soliton mode-locked Er-doped fiber ring laser

We report on a compact passive mode-locked Er:fiber ring laser operated at the fundamental repetition rate of 517 MHz, which we believe is the highest fundamental repetition rate ever reported in a ring cavity fiber laser.The key technique is the employment of two innovative high-power wavelength domain multiplexer collimators with all gain fiber cavity suited for the high power(up to 2 W) pumping. The laser is featured with a direct chirpfree output pulse, which is 97 fs without extracavity compression at an average output power of 90 mW.

73 nJ, 109 fs Yb-doped fiber laser at 19 MHz repetition rate in amplifier similariton regime

We report femtosecond pulse generation in an amplifier similariton oscillator and a prechirped fiber amplifier system. The final output power is 1.4W, and the fundamental repetition rate is 19.1 MHz after a single state fiber amplifier. The pulsewidth is 109 fs.

Reviving Low-Temperature Performance of Lithium Batteries by Emerging Electrolyte Systems

Although lithium batteries have been successfully commercialized in the past two decades,they are particularly sensitive to ultralow temperatures.For most batteries,capacities and powers are lost at sub-zero temperatures,mainly due to the increased electrolyte viscosity,insufficient ionic conduction,slow charge-transfer kinetics,and reduced ion diffusing constant.In this review,we sorted out the critical factors leading to the poor low-temperature performance of electrolytes,and the comprehensive research progress of emerging electrolyte systems for the ultra-low temperature lithium battery is classified and highlighted.We further provide a systematic summary of the advanced characterization and computational simulation for low-temperature electrolyte systems to guide researchers in screening the low-temperature electrolytes,monitoring solvation/desolvation behavior,and investigating reaction mechanisms.Besides their fundamental significance,our review might also forge a new opportunity and prospects in the effective design of electrolytes for the ultralow temperature application of energy storage devices.

Chirality-Induced Giant Unidirectional Magnetoresistance in Twisted Bilayer Graphene

Twisted bilayer graphene(TBG)exhibits fascinating correlation-driven phenomena like the superconductivity and Mott insulating state,with flat bands and a chiral lattice structure.We find by quantum-transport calculations that the chirality leads to a giant unidirectional magnetoresistance(UMR)in TBG,where the unidirectionality refers to the resistance change under the reversal of the direction of current or magnetic field.We point out that flat bands significantly enhance this effect.The UMR increases quickly upon reducing the twist angle,and reaches about 20%for an angle of 1.5
in a 10 T in-plane magnetic field.We propose the band structure topology(asymmetry),which leads to a direction-sensitive mean free path,as a useful way to anticipate the UMR effect.The UMR provides a probe for chirality and band flatness in the twisted bilayers.

Short mid-infrared watt-level all-fiber nonlinear pulse compressor above 100-MHz pulse repetition rate

We firstly report a 2-μm all-fiber nonlinear pulse compressor based on two pieces of normal dispersion fiber(NDF),which enables a high-power scaling ability of watt-level and a high pulse compression ratio of 13.7.With the NDFbased all-fiber nonlinear pulse compressor,the 450-fs laser pulses with a repetition rate of 101.4 MHz are compressed to 35.1 fs,corresponding to a 5.2 optical oscillation cycle at the 2-μm wavelength region.The output average power reaches 1.28 W,which is believed to be the highest value never achieved from the previous 2-μm all-fiber nonlinear pulse compressors with a high pulse repetition rate above 100 MHz.The dynamic evolution of the ultrafast pulse inside the all-fiber nonlinear pulse compressor is numerically analyzed,matching well with the experimental results.

Three-Dimensional Topological States of Phonons with Tunable Pseudospin Physics

Efcient control of phonons is crucial to energy-information technology,but limited by the lacking of tunable degrees of freedom like charge or spin.Here we suggest to utilize crystalline symmetry-protected pseudospins as new quantum degrees of freedom to manipulate phonons.Remarkably,we reveal a duality between phonon pseudospins and electron spins by presenting Kramerslike degeneracy and pseudospin counterparts of spin-orbit coupling,which lays the foundation for“pseudospin phononics”.Furthermore,we report two types of three-dimensional phononic topological insulators,which give topologically protected,gapless surface states with linear and quadratic band degeneracies,respectively.Tese topological surface states display unconventional phonon transport behaviors attributed to the unique pseudospin-momentum locking,which are useful for phononic circuits,transistors,antennas,etc.Te emerging pseudospin physics ofers new opportunities to develop future phononics.