The inter-annual variability of the Yellow Sea Warm Current surface axis and its influencing factors

Based on the Pathfinder sea surface temperature(PFSST),the surface axis and its pattern of the Yellow Sea Warm Current(YSWC) are discussed.A structure of double-warm-tongue is found in February and it varies in different years.Two indexes are calculated to represent the westward shift(WSI) and northward extension(NEI) of the warm water in the Yellow Sea(YS).Wavelet analysis illustrates that the WSI and NEI have prominent periods of 3-6 years and 3-4 years,respectively.The Empirical Orthogonal Function(EOF) decomposition is applied to the winter wind stress curl and the Kuroshio Current(KC) transport,which are believed to play important roles in forcing the variability of the YSWC surface axis.Statistics shows that the WSI is significantly related with the second EOF mode of the wind stress curl in February,which may force the YSWC surface axis moving westward and maintaining the double warm tongues because of its opposite curl in the YSWC domain.The first EOF mode of wind stress curl in January is propitious for inducing the warm tongue in the YS to advance more northward.Hence,the wind stress curls both in January and in February could force variations of the YSWC surface axis;however,the effect of the January wind stress curl is relatively weaker than that of the February.The relationship between the NEI and the KC transport is remarkable,and it seems that the stronger KC supplies more power to push the YSWC northward against the southward wind.

A Compound Algorithm of Denoising Using Second-Order and Fourth-Order Partial Differential Equations

In this paper, we propose a compound algorithm for the image restoration. The algorithm is a convex combination of the ROF model and the LLT model with a parameter function 0. The numerical experiments demonstrate that our compound algorithm is efficient and preserves the main advantages of the two models. In particular, the errors of the compound algorithm in L2 norm between the exact images and corresponding restored images are the smallest among the three models. For images with strong noises, the restored images of the compound algorithm are the best in the corresponding restored images. The proposed algorithm combines the fixed point method, an improved AMG method and the Krylov acceleration. It is found that the combination of these methods is efficient and robust in the image restoration.

Protective Effects of cis-2-Dodecenoic Acid in an Experimental Mouse Model of Vaginal Candidiasis

Objective To evaluate the efficacy of cis-2-dodecenoic acid(BDSF) in the treatment and prevention of vaginal candidiasis in vivo. Methods The activities of different concentrations of BDSF against the virulence factors of Candida albicans(C. albicans) were determined in vitro. An experimental mouse model of Candida vaginitis was treated with 250 μmol/L BDSF. Treatment efficiency was evaluated in accordance with vaginal fungal burden and inflammation symptoms. Results In vitro experiments indicated that BDSF attenuated the adhesion and damage of C. albicans to epithelial cells by decreasing phospholipase secretion and blocking filament formation. Treatment with 30 μmol/L BDSF reduced the adhesion and damage of C. albicans to epithelial cells by 36.9% and 42.3%, respectively. Treatment with 200 μmol/L BDSF completely inhibited phospholipase activity. In vivo mouse experiments demonstrated that BDSF could effectively eliminate vaginal infection and relieve inflammatory symptoms. Four days of treatment with 250 μmol/L BDSF reduced vaginal fungal loads by 6-fold and depressed inflammation. Moreover, BDSF treatment decreased the expression levels of the inflammatory chemokine-associated genes MCP-1 and IGFBP3 by 2.5-and 2-fold, respectively. Conclusion BDSF is a novel alternative drug that can efficiently control vaginal candidiasis by inhibiting the virulence factors of C. albicans.

Switching of K-Q intervalley trions fine structure and their dynamics in n-doped monolayer WS_(2)

Monolayer group VI transition metal dichalcogenides(TMDs)have recently emerged as promising candidates for photonic and opto-valleytronic applications.The optoelectronic properties of these atomically-thin semiconducting crystals are strongly governed by the tightly bound electron-hole pairs such as excitons and trions(charged excitons).The anomalous spin and valley configurations at the conduction band edges in monolayer WS_(2)give rise to even more fascinating valley many-body complexes.Here we find that the indirect Q valley in the first Brillouin zone of monolayer WS_(2)plays a critical role in the formation of a new excitonic state,which has not been well studied.By employing a high-quality h-BN encapsulated WS_(2)field-effect transistor,we are able to switch the electron concentration within K-Q valleys at conduction band edges.Consequently,a distinct emission feature could be excited at the high electron doping region.Such feature has a competing population with the K valley trion,and experiences nonlinear power-law response and lifetime dynamics under doping.Our findings open up a new avenue for the study of valley many-body physics and quantum optics in semiconducting 2D materials,as well as provide a promising way of valley manipulation for next-generation entangled photonic devices.

Thermal Decay and Reversal of Exchange Bias Field of CoFe/PtMn Bilayer after Ga+Irradiation

An applied field is used to perform Ga^(+)ion irradiation on a CoFe/PtMn bilayer.Effects of the applied field and energy transfer between Ga^(+)ions and antiferromagnetic(AFM)atoms on the exchange bias field Hex are investigated.A partially reversed H_(ex)is found in CoFe/PtMn specimens irradiated at a dose of 1×10^(14)ions/cm^(2)with an applied field anti-parallel to the original exchange bias direction.We believe that the rapid energy transfer and local temperature increase originating from the interaction between Ga^(+)ions and AFM atoms result in spin reversal and the formation of reversed AFM domains when specimens are irradiated with anti-parallel fields.The decrease in H_(ex)when annealing the film in a negative saturation field indicates a thermal decay process.The AFM moments are reversed by thermal activation over an energy barrier distribution,which may change in some way as the temperature increases.

Nonlinear Absorption and Low-threshold Two-photon Pumped Amplified Stimulated Emission from FAPbBr_(3) Nanocrystals

Formamidinium lead bromide(FAPbBr_(3))nanocrystals(NCs)have been considered to be a good optoelectronic material due to their pure green emission,excellent stability and superior carrier transport characteristics.However,two-photon pumped amplified spontaneous emission(ASE)and the corresponding nonlinear optical properties of FAPbBr_(3) NCs are scarcely revealed.Herein,we synthesized colloidal FAPbBr_(3) NCs with different sizes by changing the molar ratio of FABr/PbBr_(2) in the precursor solution,using ligand assisted precipitation(LARP)technology at room temperature.Photoluminescence(PL)and time resolved photoluminescence(TRPL)spectroscopy were measured to characterize their ASE properties.And their nonlinear optical properties were studied through the Zscan technique and the two-photon excited fluorescence method.The stimulated emission properties including oneand two-photon pumped ASE have been realized from FAPbBr_(3) NCs.With large two-photon absorption coefficient(0.27 cm/GW)and high non-linear absorption cross-section(7.52×10^(5) GM),ASE with threshold as low as 9.8μJ/cm^(2) and 487μJ/cm^(2) have been obtained from colloidal FAPbBr_(3) NCs using one-and two-photon excitations.These results indicate that as a new possible green-emitting frequency-upconversion material with low thresholds,FAPbBr_(3) NCs hold great potential in the development of high-performance two-photon pump lasers.

Intramolecular Hydrogen Bond Improved Durability and Kinetics for Zinc‑Organic Batteries

Organic compounds have the advantages of green sustainability and high designability,but their high solubility leads to poor durability of zinc-organic batteries.Herein,a high-performance quinone-based polymer(H-PNADBQ)material is designed by introducing an intramolecular hydrogen bonding(HB)strategy.The intramolecular HB(C=O⋯N-H)is formed in the reaction of 1,4-benzoquinone and 1,5-naphthalene diamine,which efficiently reduces the H-PNADBQ solubility and enhances its charge transfer in theory.In situ ultraviolet-visible analysis further reveals the insolubility of H-PNADBQ during the electrochemical cycles,enabling high durability at different current densities.Specifically,the H-PNADBQ electrode with high loading(10 mg cm^(-2))performs a long cycling life at 125 mA g^(-1)(>290 cycles).The H-PNADBQ also shows high rate capability(137.1 mAh g^(−1)at 25 A g^(−1))due to significantly improved kinetics inducted by intramolecular HB.This work provides an efficient approach toward insoluble organic electrode materials.

Senolystics from natural products for extending health and lifespan

Senescence,a multifaceted cellular process,intricately regulates organismal aging by imposing irreversible growth arrest on cells.This phenomenon,characterized by altered gene expression and the accumulation of senescent cells,significantly contributes to age-related physiological decline and the onset of various age-associated pathologies[1].Cellular senescence,the irreversible cessation of cell division,is intricately linked to the aging process in individuals[2].As organisms age,the accumulation of senescent cells increases,contributing to tissue dysfunction and the development of age-related pathologies.Understanding the mechanisms underlying cellular senescence holds promise for elucidating the fundamental processes governing aging and may pave the way for targeted interventions to mitigate age-associated decline[3].

Electroluminodynamic therapy for the treatment of drug-resistant pathogen infection

The administration of antibiotics has been the primary strategy for combating bacterial infections[1,2].However,the widespread and excessive use of antibiotics has resulted in the alarming rise of bacterial resistance,posing a significant threat to human health[3–5].Therefore,it is imperative to exploit innovative treatment strategy.

Overcoming the biofilm barrier by cell-like microbubbles for the treatment of biofilm-associated implant infections

Although the advent of antibiotics has significantly improved the quality of life of infected patients,bacterial infections continue to pose a serious threat to public health[1,2].According to a recent report,within the next 30 years,bacterial infections are projected to surpass cancer in terms of lethality rates,resulting in an alarming 10 million deaths annually by 2050 due to the development of bacterial resistance[3].Moreover,the formation of bacterial biofilms hampers the penetration of antibacterial agents and inhibits the host immune response,making biofilm infections extremely challenging to treat[4-7].Hence,the development of innovative antimicrobial biofilm therapeutics is imperative.

Nanozymes:Versatile Platforms for Cancer Diagnosis and Therapy

Natural enzymes usually suffer from high production cost,ease of denaturation and inactivation,and low yield,making them difficult to be broadly applicable.As an emerging type of artificial enzyme,nanozymes that combine the characteristics of nanomaterials and enzymes are promising alternatives.On the one hand,nanozymes have high enzyme-like catalytic activities to regulate biochemical reactions.On the other hand,nanozymes also inherit the properties of nanomaterials,which can ameliorate the shortcomings of natural enzymes and serve as versatile platforms for diverse applications.In this review,various nanozymes that mimic the catalytic activity of different enzymes are introduced.The achievements of nanozymes in different cancer diagnosis and treatment technologies are summarized by highlighting the advantages of nanozymes in these applications.Finally,future research directions in this rapidly developing field are outlooked.

Cis-2-dodecenoic Acid Mediates Its Synergistic Effect with Triazoles by Interfering with Efflux Pumps in Fluconazole-resistant Candida albicans

Objective To evaluate the synergy of the Burkholderia signaling molecule cis-2-dodecenoic acid(BDSF) and fluconazole(FLU) or itraconazole(ITRA) against two azole-resistant C. albicans clinical isolates in vitro and in vivo. Methods Minimum inhibitory concentrations(MICs) of antibiotics against two azole-resistant C. albicans were measured by the checkerboard technique, E-test, and time-kill assay. In vivo antifungal synergy testing was performed on mice. Analysis of the relative gene expression levels of the strains was conducted by quantitative reverse-transcription polymerase chain reaction(qR T-PCR). Results BDSF showed highly synergistic effects in combination with FLU or ITRA with a fractional inhibitory concentration index of ≤ 0.08. BDSF was not cytotoxic to normal human foreskin fibroblast cells at concentrations of up to 300 μg/mL. The qR T-PCR results showed that the combination of BDSF and FLU/ITRA significantly inhibits the expression of the efflux pump genes CDR1 and MDR1 via suppression of the transcription factors TAC1 and MRR1, respectively, when compared with FLU or ITRA alone. No dramatic difference in the mR NA expression levels of ERG1, ERG11, and UPC2 was found, which indicates that the drug combinations do not significantly interfere with UPC2-mediated ergosterol levels. In vivo experiments revealed that combination therapy can be an effective therapeutic approach to treat candidiasis. Conclusion The synergistic effects of BDSF and azoles may be useful as an alternative approach to control azole-resistant Candida infections.

Stretchable supercapacitor based on a hierarchical PPy/CNT electrode and hybrid hydrogel electrolyte with a wide operating temperature

Hydrogel is frequently used as a solid electrolyte for all solid-state supercapacitors(SCs)because of its liquid-like ion-transport property and high conformability.However,due to the higher water content,the hydrogel electrolyte undergoes inevitable freezing and/or dehydration with climate change.Herein,polypyrrole/carbon all-solid-state SCs(PCSCs)were developed based on a hierarchical polypyrrole/carbon nanotube electrode and a highly stretchable double-network polymer hydrogel electrolyte with LiCl/ethylene glycol as a mixed solvent.The PCSCs showed excellent electrochemical performance and cycle stability with a wide operating temperature.The specific capacitances could reach 202.2 and 112.3 mF cm^(−2) at current densities of 0.5 and 3.0 mA cm^(−2),respectively.Meanwhile,the PCSCs showed outstanding mechanical properties in maintaining a high areal capacitance under deformations of bending and tension.The excellent water retention of the device also ensured the stable electrochemical performance of PCSCs in a wide temperature range(30–80℃),which could potentially represent a reliable application in various harsh environments.

A novel launch dynamics measurement system for multiple launch rocket system and comparative analysis with numerical simulations

In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket’s departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS.

Resilient Time-Varying Formation-Tracking of Multi-UAV Systems Against Composite Attacks: A Two-Layered Framework

This paper studies the countermeasure design problems of distributed resilient time-varying formation-tracking control for multi-UAV systems with single-way communications against composite attacks,including denial-of-services(DoS)attacks,false-data injection attacks,camouflage attacks,and actuation attacks(AAs).Inspired by the concept of digital twin,a new two-layered protocol equipped with a safe and private twin layer(TL)is proposed,which decouples the above problems into the defense scheme against DoS attacks on the TL and the defense scheme against AAs on the cyber-physical layer.First,a topologyrepairing strategy against frequency-constrained DoS attacks is implemented via a Zeno-free event-triggered estimation scheme,which saves communication resources considerably.The upper bound of the reaction time needed to launch the repaired topology after the occurrence of DoS attacks is calculated.Second,a decentralized adaptive and chattering-relief controller against potentially unbounded AAs is designed.Moreover,this novel adaptive controller can achieve uniformly ultimately bounded convergence,whose error bound can be given explicitly.The practicability and validity of this new two-layered protocol are shown via a simulation example and a UAV swarm experiment equipped with both Ultra-WideBand and WiFi communication channels.

Effect of high-temperature buffer thickness on quality of AlN epilayer grown on sapphire substrate by metalorganic chemical vapor deposition

The effect of an initially grown high-temperature A1N buffer （HT-A1N） layer＇s thickness on the quality of an A1N epilayer grown on sapphire substrate by metalorganic chemical vapor deposition （MOCVD） in a two-step growth process is investigated. The characteristics of A1N epilayers are analyzed by using triple-axis crystal X-ray diffraction （XRD） and atomic force microscopy （AFM）. It is shown that the crystal quality of the A1N epilayer is closely related to its correlation length. The correlation length is determined by the thickness of the initially grown HT-A1N buffer layer. We find that the optimal HT-A1N buffer thickness for obtaining a high-quality A1N epilayer grown on sapphire substrate is about 20 nm.

Predefined-Time Backstepping Stabilization of Autonomous Nonlinear Systems

Dear Editor,In this letter,the backstepping technique is applied to solve the predefined-time stabilization problem for autonomous nonlinear systems,where nonlinear terms are unknown but satisfy a linear growth condition.A linear time-varying control law is designed to drive all states of an autonomous nonlinear system to the origin for an a priori preassigned time.

Perovskite-transition metal dichalcogenides heterostructures: recent advances and future perspectives

Transition metal dichalcogenides(TMDs)and perovskites are among the most attractive and widely investigated semiconductors in the recent decade.They are promising materials for various applications,such as photodetection,solar energy harvesting,light emission,and many others.Combining these materials to form heterostructures can enrich the already fascinating properties and bring up new phenomena and opportunities.Work in this field is growing rapidly in both fundamental studies and device applications.Here,we review the recent findings in the perovskite-TMD heterostructures and give our perspectives on the future development of this promising field.The fundamental properties of the perovskites,TMDs,and their heterostructures are discussed first,followed by a summary of the synthesis methods of the perovskites and TMDs and the approaches to obtain high-quality interfaces.Particular attention is paid to the TMD-perovskite heterostructures that have been applied in solar cells and photodetectors with notable performance improvement.Finally through our analysis,we propose an outline on further fundamental studies and the promising applications of perovskite-TMD heterostructures.

High-Efficiency Wide-Band Cross-Polarization Conversion Using Bi-layered Metal Hole Pairs

We present a polarization converter composed of bi-layered metal films perforated with rectangle hole pairs in each film. The proposed converter can convert the polarization of an incident linearly-polarized electromagnetic wave to its orthogonal direction with high efficiency and large bandwidth in the infrared or microwave regions.To make sure of the mechanism of polarization conversion, the current and electric-field distributions at different resonant frequencies are analyzed. It is found that the cross-polarized transmission is due to the near-field coupling between hole pairs in neighboring metal films. Finally, a prototype of the proposed converter is fabricated and measured in the microwave region. Good agreement between the experimental and simulated results is obtained.

Pharmacophore modeling for the identification of small-molecule inhibitors of TACE

OBJECTIVE To employ pharmacophore modeling to identify a TACE inhibitor from an inhouse database of 66 organic compounds.METHODS To identify the common features required for TACE inhibition,we generated a pharmacophore model from a set of TACE-selective inhibitor using the Common Feature Pharmacophore Model protocol implemented in Discovery Studio 3.1.1.A fluorimetric assay was used to investigate the potential ability of compounds to inhibit TACE enzymatic activity.The ability of compound 1 to inhibit TACE activity in a human monocyte THP-1 cell line was evaluated by ELISA.RESULTS In this study,apharmacophore model constructed from a training set of TACE inhibitors was used to screen an in-house database of organic compounds,from which compound 1 emerged as a top candidate.In a cell-free assay,compound 1inhibited TACE enzymatic activity in a dose-dependent manner.Moreover,compound 1 inhibited the production of soluble TNF-αin human acute monocytic leukemia THP-1 cells without impacting nitric oxide production,and exhibited anti-proliferative activity against THP-1cells.CONCLUSION Compound 1 was found to inhibit TACE enzymatic activity in a cell-free system and LPS-induced TNF-αsecretion in cellulo.We envisage that compound 1 may be employed as a useful scaffold for the development of more potent TACE inhibitors.