The rapid development of microfluidic technology has led to the evolution of microdroplets from simple emulsion structures to complex multilayered and multicompartmental configurations.These advancements have endowed ...The rapid development of microfluidic technology has led to the evolution of microdroplets from simple emulsion structures to complex multilayered and multicompartmental configurations.These advancements have endowed microdroplets with the capability to contain multiple compartments that remain isolated from one another,enabling them to carry different molecules of interest.Consequently,researchers can now investigate intricate spatially confined chemical reactions and signal transduction pathways within subcellular organelles.Moreover,modern microdroplets often possess excellent optical transparency,allowing fluorescently labelled,multi-layered,and compartmental droplets to provide detailed insights through real-time,in situ,and dynamic fluorescence imaging.Hence,this review systematically summarizes current methodologies for preparing multicomponent microdroplets and their applications,particularly focusing on fluorescent microdroplets.Additionally,it discusses existing critical challenges and outlines future research directions.By offering a comprehensive overview of the preparation methods and applications of fluorescent microdroplets,this review aims to stimulate the interest of researchers and foster their utilization in more complex and biomimetic environments.展开更多
Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous system.Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic...Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous system.Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic reticulum.Previously,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous system.In addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress responses.Furthermore,lipid droplets exhibit specific functions in neurons and glial cells.Dysregulation of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system diseases.This review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and functions.Additionally,it will explore the association between lipid droplets and neurodegenerative disorders.Understanding the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.展开更多
A new experimental method is developed to investigate the effect of dissolved substances on the evaporation rate of small water droplets suspended in the atmosphere.The laboratory setup is based on converting a genera...A new experimental method is developed to investigate the effect of dissolved substances on the evaporation rate of small water droplets suspended in the atmosphere.The laboratory setup is based on converting a generated droplet jet of complex structure into a directed flow of evaporating droplets falling in a vertical tube.Images of falling droplets captured by a high-speed camera through a window in the vertical channel wall are used to determine the sizes and velocities of individual droplets.The computational modeling of droplet motion and evaporation proved useful at all stages of the experimental work:from selecting the position of the vertical channel to processing the experimental data.It was found that even a 0.1%mass concentration of the dissolved ionic salt KCl has a considerable effect on decreasing the evaporation rate of the droplets.In contrast,a typical fungicide with a mass concentration of 2.5%has only a slight impact on the evaporation rate.The laboratory results enabled the authors to refine the evaporation model of water droplets to account for the presence of dissolved substances.Modified models of this type are expected to be useful in controling crop spraying and also in other potential applications.展开更多
Gallstones are a common disease worldwide,often leading to obstruction and inflammatory complications,which seriously affect the quality of life of patients.Research has shown that gallstone disease is associated with...Gallstones are a common disease worldwide,often leading to obstruction and inflammatory complications,which seriously affect the quality of life of patients.Research has shown that gallstone disease is associated with ferroptosis,lipid droplets(LDs),and abnormal levels of nitric oxide(NO).Fluorescent probes provide a sensitive and convenient method for detecting important substances in life systems and diseases.However,so far,no fluorescent probes for NO and LDs in gallstone disease have been reported.In this work,an effective ratiometric fluorescent probe LR-NH was designed for the detection of NO in LDs.With an anthracimide fluorophore and a secondary amine as a response site for NO,LR-NH exhibits high selectivity,sensitivity,and attractive ratiometric capability in detecting NO.Importantly,it can target LDs and shows excellent imaging ability for NO in cells and ferroptosis.Moreover,LR-NH can target the gallbladder and image NO in gallstone disease models,providing a unique and unprecedented tool for studying NO in LDs and gallbladder.展开更多
This numerical simulation investigates the two⁃phase flow under the condition of supercooled large droplets impinging on the aircraft surface.Based on Eulerian framework,a method for calculating supercooled water drop...This numerical simulation investigates the two⁃phase flow under the condition of supercooled large droplets impinging on the aircraft surface.Based on Eulerian framework,a method for calculating supercooled water droplet impingement characteristics is established.Then,considering the deformation and breaking effects during the movement,this method is extended to calculate the impingement characteristics of supercooled large droplets,as well as the bouncing and splashing effects during impingement.The impingement characteristics of supercooled large droplets is then investigated by this method.The results demonstrate that the deformation and breaking effects of supercooled large droplets have negligible influence on the impingement characteristics under the experimental conditions of this paper.In addition,the results of the impingement range and collection efficiency decrease when considering the bouncing and splashing effects.The bouncing effect mainly affects the mass loss near the impingement limits,while the splashing effect influences the result around the stagnation point.This investigation is beneficial for the analysis of aircraft icing and the design of anti⁃icing system with supercooled large droplet conditions.展开更多
This study experimentally investigates the oscillatory dynamics of wind-driven droplets using high-speed imaging to capture droplet profiles within the symmetry plane and to characterize their natural oscillation freq...This study experimentally investigates the oscillatory dynamics of wind-driven droplets using high-speed imaging to capture droplet profiles within the symmetry plane and to characterize their natural oscillation frequencies.Results reveal that the eigenfrequencies vary spatially due to distinct oscillation modes occurring at different droplet locations.Notably,the fundamental eigenfrequency decreases with reducing droplet volume,while droplet viscosity exerts minimal influence on this frequency.Prior to the onset of motion,the dynamic contact angle consistently remains between the advancing and receding angles.The inertial forces generated by droplet oscillation are found to be significantly greater than the adhesion forces,indicating that classical static models are inadequate for capturing inertial contributions to droplet motion.These findings offer new insights into the role of oscillatory behavior in influencing the dynamics of droplet motion,and contribute to a more detailed understanding of wind-driven droplet transport phenomena.展开更多
Splashing behavior of metal droplets is one of the main phenomena in basic oxygen furnace steelmaking process.The size distribution of metal droplets and the residence time of the metal droplets in the slag have impor...Splashing behavior of metal droplets is one of the main phenomena in basic oxygen furnace steelmaking process.The size distribution of metal droplets and the residence time of the metal droplets in the slag have important effects on the kinetics of the metal–slag reactions.The particle size distribution law,characteristic diameter,splashing velocity and splashing angle of metal droplets were investigated,and an improved prediction model of trajectory and residence time for metal droplets was established based on the combination of expanded droplets theory,decarburization mechanism model and ballistic motion principle.Meanwhile,the trajectory and residence time of metal droplets under different working conditions were analyzed based on this model.The results illustrate that the metal droplets with larger particle size are produced at low lance distance,while the metal droplets with smaller particle size are produced at high lance distance.There is a significant linear relationship between the three diameters(maximum droplet diameter,distribution characteristic diameter,reaction characteristic diameter)and the blowing number.The residence time of decarbonized metal droplets in slag is about 0.2–73 s.Meanwhile,the initial carbon content and diameter of the metal droplets and the FeO content of slag are the main factors affecting the motion state of the metal droplets in the slag,while the splashing velocity,splashing angle and the height of the foam slag have little influence.This model can be used to predict the trajectory and residence time of decarburized metal droplets in a variety of complex multiphase slag conditions,overcoming the limitation that the known model is only applicable to a few specific conditions.展开更多
Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In t...Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In this context,a novel 3D printing process is presented in which a cured structure is produced from acoustically levitated droplets without a physical vat.This enables the printing process to achieve high flexibility in the printing orientation and material supply.In pursuit of the envisioned 3D acoustic levitation printing strategy,acoustic levitation technology was utilized to suspend a photosensitive resin.Objects with small features were successfully produced by projecting patterns onto levitated resin droplets.Transforming printing orientations allows the fabrication of multiscale structures.Levitating resin droplets on-demand enables the rapid replacement of materials,thereby realizing effortless multimaterial 3D printing.By exploiting the flexibility of printing on levitation resin droplets,the capability of 3D printing on existing objects was established.Finally,an interesting example was illustrated,in which an object integrating liquid,gas,and solid materials was fabricated using the proposed 3D printing strategy.The results show that 3D printing on levitated droplets is feasible for fabricating multiscale and multimaterial objects,which contributes to the development of new 3D printing methods and potential applications.展开更多
Aqueous-phase reactions between carbonyls and reduced nitrogen compounds play a considerable role in the formation of secondary organic aerosols and brown carbon in the atmosphere.However,the reported reaction rate co...Aqueous-phase reactions between carbonyls and reduced nitrogen compounds play a considerable role in the formation of secondary organic aerosols and brown carbon in the atmosphere.However,the reported reaction rate constants for these reactions have largely been limited to bulk aqueous-phase simulations,which may not accurately represent the real state of atmospheric cloud droplets.We employed an integration of optical tweezers and Raman spectroscopy to manipulate and analyze simulated cloud droplets(size range8000-10,000 nm),comprising a mixture of glyoxal and ammonium sulfate.This approach enabled us to delve into the intricate realm of their reaction kinetics at individual droplet level mimicking cloud droplets.Raman spectroscopy provided high temporal resolution(20 s)measurements of the changes in the amount of nitrogen-containing organics(or NOCs as represented by the C-N bond)within the droplets.The results indicate that the reaction follows first-order kinetics throughout the monitoring over 80-400 min.The average reaction rate constant for the formation of NOCs within the single droplet was determined to be(6.77±0.98)×10^(-5)s^(-1),up to three orders of magnitude higher than those through the bulk aqueous-phase simulations,especially at lower p H levels.Additionally,the reaction rate constant in single droplet increases with increasing p H,consistent with the trend previously reported for the bulk aqueous-phase simulations.The results highlight the difference of the reaction rate constant between bulk aqueous-phase and droplets,which would improve our understanding on the formation and impacts of secondary organic aerosols and brown carbon in atmospheric aqueous phase.展开更多
We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is...We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is below quantum chromodynamics(QCD)scale,QGP cannot be produced.However,if the transverse momentum changes to a relatively large value,a smallscale QGP droplet is produced.The modified MIT bag model with the multiple reflection expansion method is employed to study the QGP droplet with the curved boundary effect.It is found that the energy density,entropy density and pressure of QGP with the influence are smaller than those without the influence.In the hadron phase,we propose the two-body fractal model(TBFM)to study the self-similarity structure,arising from resonance,quantum correlation and interaction effects.It is observed that the energy density,entropy density and pressure increase due to the self-similarity structure.We calculate the transverse momentum spectra of pions with the self-similarity structure influence,which show good agreement with experimental data.Considering both boundary effect and self-similarity structure influence,our model predicts an increase in the transition temperature compared to the scenarios without these two effects in the High Intensity heavy-ion Accelerator Facility(HIAF)energy region,2.2 GeV to approximately 4.5 GeV.展开更多
Two-dimensional(2D)direct numerical simulations on the dynamics of three identical ferrofluid droplets suspended in a non-magnetic ambient fluid under a rotating uniform magnetic field are conducted,and the motion and...Two-dimensional(2D)direct numerical simulations on the dynamics of three identical ferrofluid droplets suspended in a non-magnetic ambient fluid under a rotating uniform magnetic field are conducted,and the motion and deformation of the three ferrofluid droplets are studied in this paper.Results show that there are four modes(i.e.,the three droplets'direct coalescence(TC),the coalescence of two droplets and the subsequent planetary motion with the third droplet(CAP),the three droplets'planetary motion(TP),and the independent spin(IS))for the three ferrofluid droplets,dependent on the magnetic Bond number(Bom)and the initial distance(d0)between two of the droplets.It is found that the decrease in d0and the increase in Bomcan make the droplets'mode change from the IS to the planetary motion,and then turn to the CAP.Furthermore,reducing Bomor d0is helpful for the droplets to become merged.展开更多
Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions ...Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions pose significant challenges to reliable CFD predictions.A numerical model of multi-particle SLD coupling breaking,bouncing and splashing behaviors is established to explore the relationship between dynamics behavior and particle size.The results show that the peak value of droplet collection efficiencyβdecreases due to splashing.The bounce phenomenon will make the impact limit S_(m)of the water drops decrease.With the increase of the SLD particle size,the water drop bounce point gradually moves toward the trailing edge of the wing.The critical breaking diameter of SLD at an airflow velocity of 50 m/s is approximately 100μm.When the SLD particle size increases,the height of the water droplet shelter zone on the upper edge of the wing gradually decreases,and the velocity in the Y direction decreases first and then increases in the opposite direction,increasing the probability of SLD hitting the wing again.Large particle droplets have a higher effect on the impact limit S_(m)than smaller droplets.Therefore,in the numerical simulation of the SLD operating conditions,it is very important to ensure the proportion of large particle size water droplets.展开更多
Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atheroscleros...Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atherosclerosis.The aberrant accumulation of lipid droplets(LDs)in hepatocytes is a prominent signature of NAFLD.However,conventional techniques lack the capability to effectively monitor the dynamic changes in LD levels during NAFLD with living organisms.Hence,it is imperative to develop LD-specific long-wavelength fluorescent probes with high imaging contrast for the in-situ diagnosis of NAFLD.In this study,we synthesized a new LD-selective long-wavelength fluorescent probe,denoted as LD-1,based on the twisted intramolecular charge transfer(TICT)mechanism.The probe exhibits a large Stokes shift and intensive fluorescence emission in nonpolar and viscous solutions.By self-assembling LD-1 with bovine serum albumin(BSA),a biocompatible,long-wavelength fluorescent probe hybrid,LD-1@BSA,was formed,allowing for LDs to be selectively imaged in hepatocytes.Moreover,LD-1@BSA successfully discriminates NAFLD cells before and after drug treatment,and achieves non-invasive and real-time monitoring of LD accumulation in a mouse model of NAFLD.展开更多
The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly re...The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.展开更多
Abnormal accumulation and metabolism of lipid droplets can lead to a variety of diseases.Polarity,a key parameter of the microenvironment,is closely associated with many diseases and dysfunctions in the body.It is imp...Abnormal accumulation and metabolism of lipid droplets can lead to a variety of diseases.Polarity,a key parameter of the microenvironment,is closely associated with many diseases and dysfunctions in the body.It is important to elucidate the relationship between the physiological activity of lipid droplets(LDs)and the polarity of the microenvironment.In this work,based on push-pull mechanism,a fluorescent probe(E)-3-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one(PPTH)with aggregation-induced emission(AIE)properties for the detection of polarity changes in cells was synthesized.PPTH not only visualize intracellular polarity fluctuation of iron death and inflammation but also distinguish between normal and fatty liver tissue.展开更多
The study of phase transition processes in liquid crystals(LCs)remains challenging.Most thermotropic LCs exhibit a narrow temperature range and a rapid phase transition from the isotropic(ISO)to the nematic(N)phase,wh...The study of phase transition processes in liquid crystals(LCs)remains challenging.Most thermotropic LCs exhibit a narrow temperature range and a rapid phase transition from the isotropic(ISO)to the nematic(N)phase,which make it difficult to capture and manipulate the phase transition process.In this study,we observed the evolution of small droplets during the ISO–N phase transition in ferroelectric nematic(NF)LC RM734.After doping with metal nanoparticles(NPs),the temperature range of the phase transition broadened,and the droplets formed during the phase transition remained stable,with their diameter increasing linearly with temperature.In addition,droplets doped with NPs can be well controlled by an external electric field.This discovery not only aids in understanding the fundamental mechanisms of LC phase transitions but also provides a simple alternative method for preparing droplets,which is potentially valuable for applications in optoelectronic devices and sensors.展开更多
In fog, visibility is reduced. This reduction in visibility is measured by the meteorological optical range (MOR), which is important for studying human perception and various sensors in foggy conditions. The Cerema P...In fog, visibility is reduced. This reduction in visibility is measured by the meteorological optical range (MOR), which is important for studying human perception and various sensors in foggy conditions. The Cerema PAVIN Fog & Rain platform is capable of producing calibrated fog in order to better analyses it and understand its consequences. The problem is that the droplets produced by the platform are not large enough to resemble real fog. This can have a major impact on measurements since the interaction between electromagnetic waves and fog depends on the wavelength and diameter of the droplets. To remedy this, Cerema is building a new platform with new equipment capable of generating fog. This study analyses different nozzles and associated usage parameters such as the type of water used and the pressure used. The aim is to select the best nozzle with the associated parameters for producing large-diameter droplets and therefore more realistic fog.展开更多
The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional dr...The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional droplet manipulation on Nepenthes-inspired lubricated slippery surfaces via triboelectric electrostatic tweezers(TETs).The TET manipulation of droplets on a slippery surface has many advantages over electrostatic droplet manipulation on a superhydrophobic surface.The electrostatic field induces the redistribution of the charges inside the neutral droplet,which causes the triboelectric charged rod to drive the droplet to move forward under the electrostatic force.Positively or negatively charged droplets can also be driven by TET based on electrostatic attraction and repulsion.TET enables us to manipulate droplets under diverse conditions,including anti-gravity climb,suspended droplets,corrosive liquids,low-surface-tension liquids(e.g.ethanol with a surface tension of 22.3 mN·m^(-1)),different droplet volumes(from 100 nl to 0.5 ml),passing through narrow slits,sliding over damaged areas,on various solid substrates,and even droplets in an enclosed system.Various droplet-related applications,such as motion guidance,motion switching,droplet-based microreactions,surface cleaning,surface defogging,liquid sorting,and cell labeling,can be easily achieved with TETs.展开更多
The surface tension of troposphere aerosols can significantly influence their atmospheric processes and key properties, particularly on the morphology, the phase transition, the activation as cloud condensation nuclei...The surface tension of troposphere aerosols can significantly influence their atmospheric processes and key properties, particularly on the morphology, the phase transition, the activation as cloud condensation nuclei, and the gas-particle partitioning. However, directly measuring the surface tension of single ambient aerosol is quite challenging, due to the limitations of their picolitre volumes and thermal motion. Here, we developed a dual laser tweezers Raman spectroscopy(DLT-RS) system to directly sense the surface tension of single airborne microdroplets(PM10particles). A pair of aerosol droplets were trapped and driven to coalesce by the laser tweezers. Meanwhile, the backscattering light intensity and brightfield images during the coalescence process were recorded to characterize the aerosol surface tension. A remarkable advantage of directly sensing aerosol surface tension is that the solutes in aerosols are often supersaturated, which is common in atmospheric aerosols but almost unavailable in bulk solutions.We experimentally measured the surface tension of aerosols composed of nitrates or oxalic acid/nitrate mixture. Besides, the variation of surface tension during aerosol aging process was also explored, which brings possible implications on the surface evolution of actual ambient aerosol during their atmospheric lifetime.展开更多
Droplet transport still faces numerous challenges,such as a limited transport distance,large volume loss,and liquid contamination.Inspired by the principle of‘synergistic biomimetics’,we propose a design for a platf...Droplet transport still faces numerous challenges,such as a limited transport distance,large volume loss,and liquid contamination.Inspired by the principle of‘synergistic biomimetics’,we propose a design for a platform that enables droplets to be self-propelled.The orchid leaf-like three-dimensional driving structure provides driving forces for the liquid droplets,whereas the lotus leaf-like superhydrophobic surface prevents liquid adhesion,and the bamboo-like nodes enable long-distance transport.During droplet transport,no external energy input is required,no fluid adhesion or residue is induced,and no contamination or mass loss of the fluid is caused.We explore the influence of various types and parameters of wedge structures on droplet transportation,the deceleration of droplet speed at nodal points,and the distribution of internal pressure.The results indicate that the transport platform exhibits insensitivity to pH value and temperature.It allows droplets to be transported with varying curvatures in a spatial environment,making it applicable in tasks like target collection,as well as load,fused,anti-gravity,and long-distance transport.The maximum droplet transport speed reached(58±5)mm·s^(−1),whereas the transport distance extended to(136±4)mm.The developed platform holds significant application prospects in the fields of biomedicine and chemistry,such as high-throughput screening of drugs,genomic bioanalysis,microfluidic chip technology for drug delivery,and analysis of biological samples.展开更多
基金the National Nature Science Foundation of China(No.22107028)Natural Science Foundation of Chongqing(No.CSTB2023NSCQ-MSX0335)。
文摘The rapid development of microfluidic technology has led to the evolution of microdroplets from simple emulsion structures to complex multilayered and multicompartmental configurations.These advancements have endowed microdroplets with the capability to contain multiple compartments that remain isolated from one another,enabling them to carry different molecules of interest.Consequently,researchers can now investigate intricate spatially confined chemical reactions and signal transduction pathways within subcellular organelles.Moreover,modern microdroplets often possess excellent optical transparency,allowing fluorescently labelled,multi-layered,and compartmental droplets to provide detailed insights through real-time,in situ,and dynamic fluorescence imaging.Hence,this review systematically summarizes current methodologies for preparing multicomponent microdroplets and their applications,particularly focusing on fluorescent microdroplets.Additionally,it discusses existing critical challenges and outlines future research directions.By offering a comprehensive overview of the preparation methods and applications of fluorescent microdroplets,this review aims to stimulate the interest of researchers and foster their utilization in more complex and biomimetic environments.
基金funded by Basic Research Program of Shanghai,No.20JC1412200(to JW)the National Key Research and Development Program of China,No.2020YFA0113000(to RCZ)。
文摘Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous system.Lipid droplet formation begins with the synthesis of neutral lipids in the endoplasmic reticulum.Previously,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous system.In addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress responses.Furthermore,lipid droplets exhibit specific functions in neurons and glial cells.Dysregulation of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system diseases.This review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and functions.Additionally,it will explore the association between lipid droplets and neurodegenerative disorders.Understanding the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.
基金financially supported by the Russian Science Foundation(project No.24-29-00303:https://rscf.ru/project/24-29-00303/,accessed on 01 July 2025).
文摘A new experimental method is developed to investigate the effect of dissolved substances on the evaporation rate of small water droplets suspended in the atmosphere.The laboratory setup is based on converting a generated droplet jet of complex structure into a directed flow of evaporating droplets falling in a vertical tube.Images of falling droplets captured by a high-speed camera through a window in the vertical channel wall are used to determine the sizes and velocities of individual droplets.The computational modeling of droplet motion and evaporation proved useful at all stages of the experimental work:from selecting the position of the vertical channel to processing the experimental data.It was found that even a 0.1%mass concentration of the dissolved ionic salt KCl has a considerable effect on decreasing the evaporation rate of the droplets.In contrast,a typical fungicide with a mass concentration of 2.5%has only a slight impact on the evaporation rate.The laboratory results enabled the authors to refine the evaporation model of water droplets to account for the presence of dissolved substances.Modified models of this type are expected to be useful in controling crop spraying and also in other potential applications.
基金supported by the National Natural Science Foundation of China(No.22077044)the Natural Science Foundation of Hubei Province(No.2022CFA033).
文摘Gallstones are a common disease worldwide,often leading to obstruction and inflammatory complications,which seriously affect the quality of life of patients.Research has shown that gallstone disease is associated with ferroptosis,lipid droplets(LDs),and abnormal levels of nitric oxide(NO).Fluorescent probes provide a sensitive and convenient method for detecting important substances in life systems and diseases.However,so far,no fluorescent probes for NO and LDs in gallstone disease have been reported.In this work,an effective ratiometric fluorescent probe LR-NH was designed for the detection of NO in LDs.With an anthracimide fluorophore and a secondary amine as a response site for NO,LR-NH exhibits high selectivity,sensitivity,and attractive ratiometric capability in detecting NO.Importantly,it can target LDs and shows excellent imaging ability for NO in cells and ferroptosis.Moreover,LR-NH can target the gallbladder and image NO in gallstone disease models,providing a unique and unprecedented tool for studying NO in LDs and gallbladder.
基金supported in part by the National Natural Science Foundation of China(No.51806008)the Open Fund of Key Laboratory of Rotor Aerodynamics Key Laboratory(No.RAL202104-2)。
文摘This numerical simulation investigates the two⁃phase flow under the condition of supercooled large droplets impinging on the aircraft surface.Based on Eulerian framework,a method for calculating supercooled water droplet impingement characteristics is established.Then,considering the deformation and breaking effects during the movement,this method is extended to calculate the impingement characteristics of supercooled large droplets,as well as the bouncing and splashing effects during impingement.The impingement characteristics of supercooled large droplets is then investigated by this method.The results demonstrate that the deformation and breaking effects of supercooled large droplets have negligible influence on the impingement characteristics under the experimental conditions of this paper.In addition,the results of the impingement range and collection efficiency decrease when considering the bouncing and splashing effects.The bouncing effect mainly affects the mass loss near the impingement limits,while the splashing effect influences the result around the stagnation point.This investigation is beneficial for the analysis of aircraft icing and the design of anti⁃icing system with supercooled large droplet conditions.
基金supported by the National Natural Science Foundation ofChina(GrantNo.12402291)the Beijing Natural Science Foundation(No.3244043)the Research Start-up Funds of Hangzhou International Innovation Institute of Beihang University(Grant Nos.2024KQ008,2024KQ062).
文摘This study experimentally investigates the oscillatory dynamics of wind-driven droplets using high-speed imaging to capture droplet profiles within the symmetry plane and to characterize their natural oscillation frequencies.Results reveal that the eigenfrequencies vary spatially due to distinct oscillation modes occurring at different droplet locations.Notably,the fundamental eigenfrequency decreases with reducing droplet volume,while droplet viscosity exerts minimal influence on this frequency.Prior to the onset of motion,the dynamic contact angle consistently remains between the advancing and receding angles.The inertial forces generated by droplet oscillation are found to be significantly greater than the adhesion forces,indicating that classical static models are inadequate for capturing inertial contributions to droplet motion.These findings offer new insights into the role of oscillatory behavior in influencing the dynamics of droplet motion,and contribute to a more detailed understanding of wind-driven droplet transport phenomena.
基金funded by the National Natural Science Foundation of China(Nos.52374321 and 51974023)the funding of State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing(No.41621005)the Youth Science and Technology Innovation Fund of Jianlong Group-University of Science and Technology Beijing(No.20231235).
文摘Splashing behavior of metal droplets is one of the main phenomena in basic oxygen furnace steelmaking process.The size distribution of metal droplets and the residence time of the metal droplets in the slag have important effects on the kinetics of the metal–slag reactions.The particle size distribution law,characteristic diameter,splashing velocity and splashing angle of metal droplets were investigated,and an improved prediction model of trajectory and residence time for metal droplets was established based on the combination of expanded droplets theory,decarburization mechanism model and ballistic motion principle.Meanwhile,the trajectory and residence time of metal droplets under different working conditions were analyzed based on this model.The results illustrate that the metal droplets with larger particle size are produced at low lance distance,while the metal droplets with smaller particle size are produced at high lance distance.There is a significant linear relationship between the three diameters(maximum droplet diameter,distribution characteristic diameter,reaction characteristic diameter)and the blowing number.The residence time of decarbonized metal droplets in slag is about 0.2–73 s.Meanwhile,the initial carbon content and diameter of the metal droplets and the FeO content of slag are the main factors affecting the motion state of the metal droplets in the slag,while the splashing velocity,splashing angle and the height of the foam slag have little influence.This model can be used to predict the trajectory and residence time of decarburized metal droplets in a variety of complex multiphase slag conditions,overcoming the limitation that the known model is only applicable to a few specific conditions.
基金supported by National Natural Science Foundation of China(Grant No.52305398)Chengdu University of Information Technology Project(Grant No.KYTZ202145).
文摘Vat photopolymerization 3D printing creates structures by projecting patterns onto a photosensitive resin within a vat.However,the presence of resin vats limits the printing of multiscale multimaterial structures.In this context,a novel 3D printing process is presented in which a cured structure is produced from acoustically levitated droplets without a physical vat.This enables the printing process to achieve high flexibility in the printing orientation and material supply.In pursuit of the envisioned 3D acoustic levitation printing strategy,acoustic levitation technology was utilized to suspend a photosensitive resin.Objects with small features were successfully produced by projecting patterns onto levitated resin droplets.Transforming printing orientations allows the fabrication of multiscale structures.Levitating resin droplets on-demand enables the rapid replacement of materials,thereby realizing effortless multimaterial 3D printing.By exploiting the flexibility of printing on levitation resin droplets,the capability of 3D printing on existing objects was established.Finally,an interesting example was illustrated,in which an object integrating liquid,gas,and solid materials was fabricated using the proposed 3D printing strategy.The results show that 3D printing on levitated droplets is feasible for fabricating multiscale and multimaterial objects,which contributes to the development of new 3D printing methods and potential applications.
基金supported by the National Natural Science Foundation of China(Nos.42222705,42377097,and 22361162668)the National Key Research and Development Program of China(No.2022YFC3701101)+1 种基金the Youth Innovation Promotion Association CAS(No.2021354)Guangdong Foundation for Program of Science and Technology Research(No.2023B1212060049)。
文摘Aqueous-phase reactions between carbonyls and reduced nitrogen compounds play a considerable role in the formation of secondary organic aerosols and brown carbon in the atmosphere.However,the reported reaction rate constants for these reactions have largely been limited to bulk aqueous-phase simulations,which may not accurately represent the real state of atmospheric cloud droplets.We employed an integration of optical tweezers and Raman spectroscopy to manipulate and analyze simulated cloud droplets(size range8000-10,000 nm),comprising a mixture of glyoxal and ammonium sulfate.This approach enabled us to delve into the intricate realm of their reaction kinetics at individual droplet level mimicking cloud droplets.Raman spectroscopy provided high temporal resolution(20 s)measurements of the changes in the amount of nitrogen-containing organics(or NOCs as represented by the C-N bond)within the droplets.The results indicate that the reaction follows first-order kinetics throughout the monitoring over 80-400 min.The average reaction rate constant for the formation of NOCs within the single droplet was determined to be(6.77±0.98)×10^(-5)s^(-1),up to three orders of magnitude higher than those through the bulk aqueous-phase simulations,especially at lower p H levels.Additionally,the reaction rate constant in single droplet increases with increasing p H,consistent with the trend previously reported for the bulk aqueous-phase simulations.The results highlight the difference of the reaction rate constant between bulk aqueous-phase and droplets,which would improve our understanding on the formation and impacts of secondary organic aerosols and brown carbon in atmospheric aqueous phase.
基金supported by the National Natural Science Foundation of China under Grant No.12175031Guangdong Provincial Key Laboratory of Nuclear Science under Grant No.2019B121203010。
文摘We investigate the boundary effect of quark–gluon plasma(QGP)droplets and the self-similarity effect of hadrons on QGP–hadron phase transition.In intermediate-or low-energy collisions,when the transverse momentum is below quantum chromodynamics(QCD)scale,QGP cannot be produced.However,if the transverse momentum changes to a relatively large value,a smallscale QGP droplet is produced.The modified MIT bag model with the multiple reflection expansion method is employed to study the QGP droplet with the curved boundary effect.It is found that the energy density,entropy density and pressure of QGP with the influence are smaller than those without the influence.In the hadron phase,we propose the two-body fractal model(TBFM)to study the self-similarity structure,arising from resonance,quantum correlation and interaction effects.It is observed that the energy density,entropy density and pressure increase due to the self-similarity structure.We calculate the transverse momentum spectra of pions with the self-similarity structure influence,which show good agreement with experimental data.Considering both boundary effect and self-similarity structure influence,our model predicts an increase in the transition temperature compared to the scenarios without these two effects in the High Intensity heavy-ion Accelerator Facility(HIAF)energy region,2.2 GeV to approximately 4.5 GeV.
基金Project supported by the National Natural Science Foundation of China(No.12372263)。
文摘Two-dimensional(2D)direct numerical simulations on the dynamics of three identical ferrofluid droplets suspended in a non-magnetic ambient fluid under a rotating uniform magnetic field are conducted,and the motion and deformation of the three ferrofluid droplets are studied in this paper.Results show that there are four modes(i.e.,the three droplets'direct coalescence(TC),the coalescence of two droplets and the subsequent planetary motion with the third droplet(CAP),the three droplets'planetary motion(TP),and the independent spin(IS))for the three ferrofluid droplets,dependent on the magnetic Bond number(Bom)and the initial distance(d0)between two of the droplets.It is found that the decrease in d0and the increase in Bomcan make the droplets'mode change from the IS to the planetary motion,and then turn to the CAP.Furthermore,reducing Bomor d0is helpful for the droplets to become merged.
基金supported in part by the National Natural Science Foundation of China(No.52276009)。
文摘Accurate simulation of ice accretion of supercooled large droplet(SLD)is pivotal for the international airworthiness certification of large aircraft.Its complex dynamics behavior and broad particle size distributions pose significant challenges to reliable CFD predictions.A numerical model of multi-particle SLD coupling breaking,bouncing and splashing behaviors is established to explore the relationship between dynamics behavior and particle size.The results show that the peak value of droplet collection efficiencyβdecreases due to splashing.The bounce phenomenon will make the impact limit S_(m)of the water drops decrease.With the increase of the SLD particle size,the water drop bounce point gradually moves toward the trailing edge of the wing.The critical breaking diameter of SLD at an airflow velocity of 50 m/s is approximately 100μm.When the SLD particle size increases,the height of the water droplet shelter zone on the upper edge of the wing gradually decreases,and the velocity in the Y direction decreases first and then increases in the opposite direction,increasing the probability of SLD hitting the wing again.Large particle droplets have a higher effect on the impact limit S_(m)than smaller droplets.Therefore,in the numerical simulation of the SLD operating conditions,it is very important to ensure the proportion of large particle size water droplets.
基金National Natural Science Foundation of China(Nos.22107029,22377135,22305178,92253306 and 82130099)the Taishan Scholars Program(No.tsqn202312305)+7 种基金the Young Elite Scientists Sponsorship Program by Chinese Chemical Societythe Fundamental Research Projects of Science&Technology Innovation and development Plan in Yantai City(No.2023JCYJ059)the Shandong Laboratory Program(No.SYS202205)the Fundamental Research Funds for the Central Universities(No.222201717003)the Programme of Introducing Talents of Discipline to Universities(No.B16017)the Open Funding Project of the State Key Laboratory of Bioreactor Engineeringthe State Key Laboratory of Drug Research(No.SKLDR-2023-KF-10)the Ministry of Education Key Laboratory on signaling Regulation and Targeting Therapy of Liver Cancer(Naval Medical University)(No.2023-MEKLLCMS/ZD-00*)。
文摘Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atherosclerosis.The aberrant accumulation of lipid droplets(LDs)in hepatocytes is a prominent signature of NAFLD.However,conventional techniques lack the capability to effectively monitor the dynamic changes in LD levels during NAFLD with living organisms.Hence,it is imperative to develop LD-specific long-wavelength fluorescent probes with high imaging contrast for the in-situ diagnosis of NAFLD.In this study,we synthesized a new LD-selective long-wavelength fluorescent probe,denoted as LD-1,based on the twisted intramolecular charge transfer(TICT)mechanism.The probe exhibits a large Stokes shift and intensive fluorescence emission in nonpolar and viscous solutions.By self-assembling LD-1 with bovine serum albumin(BSA),a biocompatible,long-wavelength fluorescent probe hybrid,LD-1@BSA,was formed,allowing for LDs to be selectively imaged in hepatocytes.Moreover,LD-1@BSA successfully discriminates NAFLD cells before and after drug treatment,and achieves non-invasive and real-time monitoring of LD accumulation in a mouse model of NAFLD.
基金supported by the Beijing Municipal Natural Science Foundation(JQ20015)National Key Research and Development Program of China(No.2022YFB4601300)+3 种基金the National Science Fund for Distinguished Young Scholars(No.52325505)the National Natural Science Foundation of China(NSFC)(No.52075041)the Joint Funds of the National Natural Science Foundation of China(Grant No.U2037205)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No2021WNLOKF016)。
文摘The controllable transfer of droplets on the surface of objects has a wide application prospect in the fields of microfluidic devices,fog collection and so on.The Leidenfrost effect can be utilized to significantly reduce motion resistance.However,the use of 3D structures limits the widespread application of self-propulsion based on Leidenfrost droplets in microelectromechanical system.To manipulate Leidenfrost droplets,it is necessary to create 2D or quasi-2D geometries.In this study,femtosecond laser is applied to fabricate a surface with periodic hydrophobicity gradient(SPHG),enabling directional self-propulsion of Leidenfrost droplets.Flow field analysis within the Leidenfrost droplets reveals that the vapor layer between the droplets and the hot surface can be modulated by the SPHG,resulting in directional propulsion of the inner gas.The viscous force between the gas and liquid then drives the droplet to move.
基金the financial supports from Scientific and Technological Key Project in Henan Province(No.22170015)National Natural Science Foundation of China(No.U1704161)+2 种基金Zhengzhou University(No.32211807)Henan Provincial Science and Technology Research Project(No.JC21253010)Basic Research Foundation of Shenzhen Science and Technology Innovation(No.JCYJ20190806144605441)。
文摘Abnormal accumulation and metabolism of lipid droplets can lead to a variety of diseases.Polarity,a key parameter of the microenvironment,is closely associated with many diseases and dysfunctions in the body.It is important to elucidate the relationship between the physiological activity of lipid droplets(LDs)and the polarity of the microenvironment.In this work,based on push-pull mechanism,a fluorescent probe(E)-3-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)-1-(2-hydroxyphenyl)prop-2-en-1-one(PPTH)with aggregation-induced emission(AIE)properties for the detection of polarity changes in cells was synthesized.PPTH not only visualize intracellular polarity fluctuation of iron death and inflammation but also distinguish between normal and fatty liver tissue.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1405000)the Natural Science Foundation of Jiangsu Province(Grant No.BK20211277)+2 种基金the Frontier Leading Technology Basic Research Project of Jiangsu Province(Grant No.BK20212004)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX230971)the Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant No.NY223087).
文摘The study of phase transition processes in liquid crystals(LCs)remains challenging.Most thermotropic LCs exhibit a narrow temperature range and a rapid phase transition from the isotropic(ISO)to the nematic(N)phase,which make it difficult to capture and manipulate the phase transition process.In this study,we observed the evolution of small droplets during the ISO–N phase transition in ferroelectric nematic(NF)LC RM734.After doping with metal nanoparticles(NPs),the temperature range of the phase transition broadened,and the droplets formed during the phase transition remained stable,with their diameter increasing linearly with temperature.In addition,droplets doped with NPs can be well controlled by an external electric field.This discovery not only aids in understanding the fundamental mechanisms of LC phase transitions but also provides a simple alternative method for preparing droplets,which is potentially valuable for applications in optoelectronic devices and sensors.
文摘In fog, visibility is reduced. This reduction in visibility is measured by the meteorological optical range (MOR), which is important for studying human perception and various sensors in foggy conditions. The Cerema PAVIN Fog & Rain platform is capable of producing calibrated fog in order to better analyses it and understand its consequences. The problem is that the droplets produced by the platform are not large enough to resemble real fog. This can have a major impact on measurements since the interaction between electromagnetic waves and fog depends on the wavelength and diameter of the droplets. To remedy this, Cerema is building a new platform with new equipment capable of generating fog. This study analyses different nozzles and associated usage parameters such as the type of water used and the pressure used. The aim is to select the best nozzle with the associated parameters for producing large-diameter droplets and therefore more realistic fog.
基金supported by the USTC Research Funds of the Double First-Class Initiative(Nos.YD2090002013,YD234000009)the National Natural Science Foundation of China(Nos.61927814,62325507,52122511,U20A20290,62005262)。
文摘The use of‘Electrostatic tweezers'is a promising tool for droplet manipulation,but it faces many limitations in manipulating droplets on superhydrophobic surfaces.Here,we achieve noncontact and multifunctional droplet manipulation on Nepenthes-inspired lubricated slippery surfaces via triboelectric electrostatic tweezers(TETs).The TET manipulation of droplets on a slippery surface has many advantages over electrostatic droplet manipulation on a superhydrophobic surface.The electrostatic field induces the redistribution of the charges inside the neutral droplet,which causes the triboelectric charged rod to drive the droplet to move forward under the electrostatic force.Positively or negatively charged droplets can also be driven by TET based on electrostatic attraction and repulsion.TET enables us to manipulate droplets under diverse conditions,including anti-gravity climb,suspended droplets,corrosive liquids,low-surface-tension liquids(e.g.ethanol with a surface tension of 22.3 mN·m^(-1)),different droplet volumes(from 100 nl to 0.5 ml),passing through narrow slits,sliding over damaged areas,on various solid substrates,and even droplets in an enclosed system.Various droplet-related applications,such as motion guidance,motion switching,droplet-based microreactions,surface cleaning,surface defogging,liquid sorting,and cell labeling,can be easily achieved with TETs.
基金supported by the National Natural Science Foundation of China (Nos.U19A2007, 32150026 and 92043302)。
文摘The surface tension of troposphere aerosols can significantly influence their atmospheric processes and key properties, particularly on the morphology, the phase transition, the activation as cloud condensation nuclei, and the gas-particle partitioning. However, directly measuring the surface tension of single ambient aerosol is quite challenging, due to the limitations of their picolitre volumes and thermal motion. Here, we developed a dual laser tweezers Raman spectroscopy(DLT-RS) system to directly sense the surface tension of single airborne microdroplets(PM10particles). A pair of aerosol droplets were trapped and driven to coalesce by the laser tweezers. Meanwhile, the backscattering light intensity and brightfield images during the coalescence process were recorded to characterize the aerosol surface tension. A remarkable advantage of directly sensing aerosol surface tension is that the solutes in aerosols are often supersaturated, which is common in atmospheric aerosols but almost unavailable in bulk solutions.We experimentally measured the surface tension of aerosols composed of nitrates or oxalic acid/nitrate mixture. Besides, the variation of surface tension during aerosol aging process was also explored, which brings possible implications on the surface evolution of actual ambient aerosol during their atmospheric lifetime.
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.52275420)the National Key R&D Program of China(2022YFB3403304)the Natural Science Foundation of Hunan Province[Grant No.2022JJ30136].
文摘Droplet transport still faces numerous challenges,such as a limited transport distance,large volume loss,and liquid contamination.Inspired by the principle of‘synergistic biomimetics’,we propose a design for a platform that enables droplets to be self-propelled.The orchid leaf-like three-dimensional driving structure provides driving forces for the liquid droplets,whereas the lotus leaf-like superhydrophobic surface prevents liquid adhesion,and the bamboo-like nodes enable long-distance transport.During droplet transport,no external energy input is required,no fluid adhesion or residue is induced,and no contamination or mass loss of the fluid is caused.We explore the influence of various types and parameters of wedge structures on droplet transportation,the deceleration of droplet speed at nodal points,and the distribution of internal pressure.The results indicate that the transport platform exhibits insensitivity to pH value and temperature.It allows droplets to be transported with varying curvatures in a spatial environment,making it applicable in tasks like target collection,as well as load,fused,anti-gravity,and long-distance transport.The maximum droplet transport speed reached(58±5)mm·s^(−1),whereas the transport distance extended to(136±4)mm.The developed platform holds significant application prospects in the fields of biomedicine and chemistry,such as high-throughput screening of drugs,genomic bioanalysis,microfluidic chip technology for drug delivery,and analysis of biological samples.
