Point-of-care diagnostics and inline quantitative phase imaging(QPI)drive the demand for portable,ultra-miniaturized,and robust optical imaging and metrology systems.We propose and demonstrate a wavefront sensor integ...Point-of-care diagnostics and inline quantitative phase imaging(QPI)drive the demand for portable,ultra-miniaturized,and robust optical imaging and metrology systems.We propose and demonstrate a wavefront sensor integrated into a photonic integrated circuit,enabling single-shot optical phase retrieval.We implemented an integrated wavefront sensor array with a spatial resolution of 17μm and a numerical aperture of 0.1.Furthermore,we experimentally demonstrated the reconstruction of wavefronts defined by Zernike polynomials,specifically the first 14 terms(Z_(1)to Z_(14)),achieving an average root mean square error below 0.07.This advancement paves the way for fully integrated,portable,and robust optical imaging systems,facilitating integrated wavefront sensors in demanding applications such as point-of-care diagnostics,endoscopy,in situ QPI,and inline surface profile measurement.展开更多
Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission ...Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission are associated with pathophysiological and neurodegenerative disorders,whereas glucagon-like peptide-1 has demonstrated neuroprotective effects.However,it is not yet clear whether diabetes causes alterations in inhibitory input to retinal ganglion cells and whether and how glucagon-like peptide-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to retinal ganglion cells.In the present study,we used the patch-clamp technique to recordγ-aminobutyric acid subtype A receptor-mediated miniature inhibitory postsynaptic currents in retinal ganglion cells from streptozotocin-induced diabetes model rats.We found that early diabetes(4 weeks of hyperglycemia)decreased the frequency of GABAergic miniature inhibitory postsynaptic currents in retinal ganglion cells without altering their amplitude,suggesting a reduction in the spontaneous release ofγ-aminobutyric acid to retinal ganglion cells.Topical administration of glucagon-like peptide-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency,subsequently enhancing the survival of retinal ganglion cells.Concurrently,the protective effects of glucagon-like peptide-1 on retinal ganglion cells in diabetic rats were eliminated by topical administration of exendin-9-39,a specific glucagon-like peptide-1 receptor antagonist,or SR95531,a specific antagonist of theγ-aminobutyric acid subtype A receptor.Furthermore,extracellular perfusion of glucagon-like peptide-1 was found to elevate the frequencies of GABAergic miniature inhibitory postsynaptic currents in both ON-and OFF-type retinal ganglion cells.This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca2+/protein kinase C signaling pathway downstream of glucagon-like peptide-1 receptor activation.Moreover,multielectrode array recordings revealed that glucagon-like peptide-1 functionally augmented the photoresponses of ON-type retinal ganglion cells.Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of glucagon-like peptide-1.These results suggest that glucagon-like peptide-1 facilitates the release ofγ-aminobutyric acid onto retinal ganglion cells through the activation of glucagon-like peptide-1 receptor,leading to the de-excitation of retinal ganglion cell circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy.Collectively,our findings indicate that theγ-aminobutyric acid system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy.Furthermore,the topical administration of glucagon-like peptide-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.展开更多
1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(I...1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).展开更多
1.Introduction.In recent decades,the pursuit of miniaturization has been crucial in nanofabrication,fostering innovation,and enabling novel applications in chip manufacturing,nanophotonics,and quantum devices[1,2].Adv...1.Introduction.In recent decades,the pursuit of miniaturization has been crucial in nanofabrication,fostering innovation,and enabling novel applications in chip manufacturing,nanophotonics,and quantum devices[1,2].Advancements in nanofabrication technology are driven by the demand for higher component density and performance,necessitating precise material processing in atmospheric environments.展开更多
Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptabilit...Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptability and safety.Various materials and actuation strategies have been developed for creating soft robots,among which,ferromagnetic soft materials that self-actuate in response to external magnetic fields have attracted worldwide attention due to their remote controllability and excellent compatibil-ity with biological tissues.This review presents comprehensive and systematic research advancements in the design,fabrication,and applications of ferromagnetic soft materials for miniature robots,providing in-sights into their potential use in biomedical fields and beyond.The programming strategies of ferromag-netic soft materials are summarized and classified,including mold-assisted programming,3D printing-assisted programming,microassembly-assisted programming,and magnetization reprogramming.Each approach possesses unique advantages in manipulating the magnetic responsiveness of ferromagnetic soft materials to achieve outstanding actuation and deformation performances.We then discuss the biomedi-cal applications of ferromagnetic soft material-based soft robots(e.g.,minimally invasive surgery,targeted delivery,and tissue engineering),highlighting their potentials in revolutionizing biomedical technologies.This review also points out the current challenges and provides insights into future research directions,which we hope can serve as a useful reference for the development of next-generation adaptive miniature robots.展开更多
A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,a...A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,and this new structure enables a planar integrated transition from microstrip lines to ultra-thin cavity filters,thereby reducing the size of the transition structure and achieving miniaturization.The structure includes a conventional tapered microstrip transition structure,which guides the electromagnetic field from the microstrip line to the reduced-height dielectric-filled waveguide,and an air-filled matching cavity which is placed between the dielectric-filled waveguide and the ultra-thin cavity filter.The heights of the microstrip line,the dielectric-filled waveguide and the ultra-thin cavity filter are the same,enabling seamless integration within a planar radio-frequency(RF)circuit.To facilitate testing,mature finline transition structures are integrated at both ends of the microstrip line during fabrications.The simulation results of the fabricated microstrip to ultra-thin cavity filter transition with the finline transition structure,with a passband of 91.5-96.5 GHz,has an insertion loss of less than 1.9 dB and a return loss lower than-20 dB.And the whole structure has also been measured which achieves an insertion loss less than 2.6 dB and a return loss lower than-15 dB within the filter's passband,including the additional insertion loss introduced by the finline transitions.Finally,a W-band compact up-conversion module is designed,and the test results show that after using the proposed structure,the module achieves 95 dBc suppression of the 84 GHz local oscillator.It is also demonstrated that the structure proposed in this letter achieves miniaturization of the system integration without compromising the filter performance.展开更多
The paleoenvironmental changes and adaptation strategies of hominins during the Late Pleistocene are crucial for understanding the evolution,dispersal,and behavioral shifts of early modern humans.Despite South China&#...The paleoenvironmental changes and adaptation strategies of hominins during the Late Pleistocene are crucial for understanding the evolution,dispersal,and behavioral shifts of early modern humans.Despite South China's significance as a nexus for hominin dispersal and handaxe technology diffusion,quantitative reconstructions of paleoenvironments linked to archaeological records remain scarce.The Sandinggai site(96.6-13.3 ka BP)in central South China,with its well-preserved stratigraphy and abundant lithic artefacts,is notable for providing valuable insights.In this study,quantitative reconstruction of the vegetation succession and climate change sequences at the site was conducted using palynological and isotopic data.The results indicated a shift from a warm-temperate evergreen and deciduous broadleaf mixed forest to a temperate deciduous broadleaf forest,with the climate transitioning from warm and humid to cooler and drier conditions.During the early phase,an increase in lithic production suggested favorable conditions for hominin survival.In the later phase,decreased lithic production and the replacement of large handaxe tools by smaller flake tools,indicated that hominins adapted to the cooler,drier climate and more open landscapes through lithic miniaturization.These findings highlight the environment-driven adaptation of lithic technology and hominin behavior,thereby shedding light on human survival adaptation strategies.展开更多
This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal sp...This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal split-ring structure controlled via two radio frequency(RF) positive-intrinsicnegative(PIN) diodes(BAR64-02V). While the antenna is primarily designed to operate at 3.50 GHz for sub-6 GHz 5G applications, RF switching enables the CSRA to cover a broader frequency spectrum, including the S-band, X-band, and portions of the Ku-band. The proposed antenna offers several advantages: It is low-cost(fabricated on an FR-4 substrate), compact(achieving 64.07% size reduction compared to conventional designs), and features both frequency and gain reconfigurability through digitally controlled PIN diode switching. The reflection coefficients of the antenna, both without diodes and across all four switching states, were experimentally validated in the laboratory using a Keysight Field Fox microwave analyzer(N9916A, 14 GHz). The simulated radiation patterns and gain characteristics closely matched the measured values, demonstrating an excellent agreement. This study bridges the gap between traditional and next-generation antenna designs by offering a compact,cost-effective, and high-performance solution for multiband, reconfigurable wireless communication systems. The integration of double-split-ring resonators and dynamic reconfigurability makes the proposed antenna a strong candidate for various applications, including S-band and X-band systems, as well as the emerging lower 6G band(7.125 GHz–8.400 GHz).展开更多
Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization....Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization.In this context,mechanical properties have emerged as critical parameters for evaluating the operational performance and longevity of materials and devices at the micro/nanoscale.展开更多
Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater...Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.展开更多
Adhesive patches offer an effective approach for wound closure,making them highly suitable for biomedical applications.However,conventional patches often face limitations such as dual-sided adhesion,lack of shape adap...Adhesive patches offer an effective approach for wound closure,making them highly suitable for biomedical applications.However,conventional patches often face limitations such as dual-sided adhesion,lack of shape adaptability,and limited maneuverability,which restrict their applications in deeper tissues.In this paper,we develop a magnetic patch robot(PatchBot),for targeted Janus adhesion with tissues.The PatchBot features a unique triple-layer structure,with adhesive,shape-morphing,and anti-adhesive layers,each fulfilling roles to support targeted attachment,enable shape transformation,and prevent unwanted adhesion to surrounding tissues.The Janus adhesion of the PatchBot was extensively demonstrated across a variety of tissues.A localized near-infrared(NIR)laser irradiation was used to induce programmable shape transformations.Magnetic actuation of the PatchBot for targeted adhesion was successfully demonstrated in ex vivo porcine stomach tissue.NIR light-activated shape-morphing and multimodal magnetic actuation significantly enhance its maneuverability and adaptability in confined in vivo environments while ensuring the structural integrity of the adhesive surface during deployment.This proof-of-concept study demonstrates the feasibility of using PatchBot for targeted wound adhesion,showing its potential for minimally invasive,precision therapies in complex in vivo environments.展开更多
Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this...Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this review,we systematically survey the basics of MHMRs,from propulsion mechanism,magnetization and control methods to biomedical applications,aiming to provide readers with an easily understandable overview and fundamental knowledge on implementing MHMRs.The MHMRs are actuated by rotating magnetic fields,achieving steering and rotation through magnetic torque,and converting rotation into forward motion through the helical structure.Magnetization methods for MHMRs are reviewed into three types:attaching magnets,magnetic coatings,and magnetic powder doping.Additionally,this review discusses the control methods for MHMRs,covering imaging techniques,path tracking control—including classical control algorithms and increasingly popular learning-based methods,and swarm control.Subsequently,a comprehensive survey is conducted on the biomedical applications of MHMRs in the treatment of vascular diseases,drug delivery,cell delivery,and their integration with catheters.We finally provide a perspective about future challenges in MHMR research,including enhancing functional design capabilities,developing swarm-assisted independent control mechanisms,refining in vivo imaging techniques,and ensuring robust biocompatibility for safe medical use.展开更多
Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In orde...Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In order to further reduce the size and improve the performance of the proposed filter,defected ground structure(DGS)has been implemented in the filter.Based on this structure,the volume of the inductor is reduced by 60%eficiently compared with the inductor without DGS,and the Q-factor is increased up to 257%compared with the traditional multilayer spiral inductor.The measured results indicate that the designed filter has a very sharp stopband,an insertion loss of 2.3dB,and a return loss of 18.6dB in the passband.The whole volume of the fabricated filter is 0.032入_(g)×0.05入_(g)×0.00075入_(g),where Ag is the guided wavelength of the center frequency.The proposed filter is easily integrated into radio-frequency/microwave circuitry at a low manufacturing cost,especially wireless communication.展开更多
Over the past three decades,there has been increasing interest in miniaturized percutaneous nephrolithotomy(mPCNL)techniques featuring smaller tracts as they offer potential solutions to mitigate complications associa...Over the past three decades,there has been increasing interest in miniaturized percutaneous nephrolithotomy(mPCNL)techniques featuring smaller tracts as they offer potential solutions to mitigate complications associated with standard PCNL(sPCNL).However,despite this growing acceptance and recognition of its benefits,unresolved controversies and acknowledged limitations continue to impede widespread adoption due to a lack of consensus on optimal perioperative management strategies and procedural tips and tricks.In response to these challenges,an international panel comprising experts from the International Alliance of Urolithiasis(IAU)took on the task of compiling an expert consensus document on mPCNL procedures aimed at providing urologists with a comprehensive clinical framework for practice.This endeavor involved conducting a systematic literature review to identify research gaps(RGs),which formed the foundation for developing a structured questionnaire survey.Subsequently,a two-round modified Delphi survey was implemented,culminating in a group meeting to generate final evidence-based comments.All 64 experts completed the second-round survey,resulting in a response rate of 100.0%.Fifty-eight key questions were raised focusing on mPCNLs within 4 main domains,including general information(13 questions),preoperative work-up(13 questions),procedural tips and tricks(19 questions),and postoperative evaluation and follow-up(13 questions).Additionally,9 questions evaluated the experts’experience with PCNLs.Consensus was reached on 30 questions after the second-round survey,while professional statements for the remaining 28 key questions were provided after discussion in an online panel meeting.mPCNL,characterized by a tract smaller than 18 Fr and an innovative lithotripsy technique,has firmly established itself as a viable and effective approach for managing upper urinary tract stones in both adults and pediatrics.It offers several advantages over sPCNL including reduced bleeding,fewer requirements for nephrostomy tubes,decreased pain,and shorter hospital stays.The series of detailed techniques presented here serve as a comprehensive guide for urologists,aiming to improve their procedural understanding and optimize patient outcomes.展开更多
A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies pe...A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.展开更多
Miniaturized two-photon microscopes(m2PMs)enable high-resolution,deep-brain imaging in freely behaving animals.However,the trade-offs among weight,form factor,and optical performance in conventional refractive objecti...Miniaturized two-photon microscopes(m2PMs)enable high-resolution,deep-brain imaging in freely behaving animals.However,the trade-offs among weight,form factor,and optical performance in conventional refractive objectives present major obstacles to achieving large field-of-view(FOV),high-resolution imaging in weightsensitive or multiregion applications.Metalenses offer ultralight,high-NA,aberration-corrected alternatives,but face persistent challenges,including restricted FOV,off-axis aberrations,and dual-band optimization for two-photon imaging.Here,we present Meta-m2PM 2.0,a 1.06 g headpiece featuring a compound metalens architecture with a two-stage imaging design that decouples scanning and focusing.We designed and fabricated a large-angle(±12°)metalens-based scan lens and a high-NA(0.48)dual-layer metalens-based objective,both derived from our established polarization-insensitive Si_(3)N_(4)meta-atom library co-optimized for focusing and transmission at 920 nm excitation and 500–560 nm fluorescence collection.Meta-m2PM 2.0 achieves a 350×330μm^(2)FOV(>50×that of Meta-m2PM 1.0),with 1.17μm lateral and 19.85μm axial resolution at the center,while maintaining>80%lateral resolution uniformity across the FOV,and extending imaging depth to 210μm(~3×deeper).We demonstrate dendritic imaging in head-fixed awake mice and,to our knowledge,the first metalens-based two-photon calcium imaging in freely behaving mice with a high signal-to-noise ratio,paving the way for ultralight multiregion neuroimaging and compact nonlinear microendoscopy.展开更多
Flapping-Wing Micro Air Vehicles(FMAVs)are compact and agile,capable of accessing narrow spaces that conventional vehicles struggle to reach,such as ruins,caves,or the interiors of complex structures,making them ideal...Flapping-Wing Micro Air Vehicles(FMAVs)are compact and agile,capable of accessing narrow spaces that conventional vehicles struggle to reach,such as ruins,caves,or the interiors of complex structures,making them ideal tools for reconnaissance and rescue missions.1 However,the operation of FMAVs relies on coordinating multiple forces with different scaling effects,posing challenges to miniaturization design.展开更多
Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,...Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52175509 and 52450158)the National Key Research and Development Program of China(Grant No.2023YFF1500900)+2 种基金the Shenzhen Fundamental Research Program(Grant No.JCYJ20220818100412027)the Guangdong-Hong Kong Technology Cooperation Funding Scheme Category C Platform(Grant No.SGDX20230116093543005)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)。
文摘Point-of-care diagnostics and inline quantitative phase imaging(QPI)drive the demand for portable,ultra-miniaturized,and robust optical imaging and metrology systems.We propose and demonstrate a wavefront sensor integrated into a photonic integrated circuit,enabling single-shot optical phase retrieval.We implemented an integrated wavefront sensor array with a spatial resolution of 17μm and a numerical aperture of 0.1.Furthermore,we experimentally demonstrated the reconstruction of wavefronts defined by Zernike polynomials,specifically the first 14 terms(Z_(1)to Z_(14)),achieving an average root mean square error below 0.07.This advancement paves the way for fully integrated,portable,and robust optical imaging systems,facilitating integrated wavefront sensors in demanding applications such as point-of-care diagnostics,endoscopy,in situ QPI,and inline surface profile measurement.
基金supported by the National Natural Science Foundation of China,Nos.32070989(to YMZ),31872766(to YMZ),81790640(to XLY),and 82070993(to SJW)the grant from Sanming Project of Medicine in Shenzhen,No.SZSM202011015(to XLY)。
文摘Diabetic retinopathy is a prominent cause of blindness in adults,with early retinal ganglion cell loss contributing to visual dysfunction or blindness.In the brain,defects inγ-aminobutyric acid synaptic transmission are associated with pathophysiological and neurodegenerative disorders,whereas glucagon-like peptide-1 has demonstrated neuroprotective effects.However,it is not yet clear whether diabetes causes alterations in inhibitory input to retinal ganglion cells and whether and how glucagon-like peptide-1 protects against neurodegeneration in the diabetic retina through regulating inhibitory synaptic transmission to retinal ganglion cells.In the present study,we used the patch-clamp technique to recordγ-aminobutyric acid subtype A receptor-mediated miniature inhibitory postsynaptic currents in retinal ganglion cells from streptozotocin-induced diabetes model rats.We found that early diabetes(4 weeks of hyperglycemia)decreased the frequency of GABAergic miniature inhibitory postsynaptic currents in retinal ganglion cells without altering their amplitude,suggesting a reduction in the spontaneous release ofγ-aminobutyric acid to retinal ganglion cells.Topical administration of glucagon-like peptide-1 eyedrops over a period of 2 weeks effectively countered the hyperglycemia-induced downregulation of GABAergic mIPSC frequency,subsequently enhancing the survival of retinal ganglion cells.Concurrently,the protective effects of glucagon-like peptide-1 on retinal ganglion cells in diabetic rats were eliminated by topical administration of exendin-9-39,a specific glucagon-like peptide-1 receptor antagonist,or SR95531,a specific antagonist of theγ-aminobutyric acid subtype A receptor.Furthermore,extracellular perfusion of glucagon-like peptide-1 was found to elevate the frequencies of GABAergic miniature inhibitory postsynaptic currents in both ON-and OFF-type retinal ganglion cells.This elevation was shown to be mediated by activation of the phosphatidylinositol-phospholipase C/inositol 1,4,5-trisphosphate receptor/Ca2+/protein kinase C signaling pathway downstream of glucagon-like peptide-1 receptor activation.Moreover,multielectrode array recordings revealed that glucagon-like peptide-1 functionally augmented the photoresponses of ON-type retinal ganglion cells.Optomotor response tests demonstrated that diabetic rats exhibited reductions in visual acuity and contrast sensitivity that were significantly ameliorated by topical administration of glucagon-like peptide-1.These results suggest that glucagon-like peptide-1 facilitates the release ofγ-aminobutyric acid onto retinal ganglion cells through the activation of glucagon-like peptide-1 receptor,leading to the de-excitation of retinal ganglion cell circuits and the inhibition of excitotoxic processes associated with diabetic retinopathy.Collectively,our findings indicate that theγ-aminobutyric acid system has potential as a therapeutic target for mitigating early-stage diabetic retinopathy.Furthermore,the topical administration of glucagon-like peptide-1 eyedrops represents a non-invasive and effective treatment approach for managing early-stage diabetic retinopathy.
基金supported by the National Natural Science Foundation of China(No.62371263)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCK25_1995).
文摘1 Introduction Recently,the increasing demand for advanced telecommunication systems has spurred extensive research into bandpass filters(BPFs),with particular emphasis on miniaturization,reduction of insertion loss(IL),and enhancement of upper stopband rejection(Huang et al.,2021;Snyder et al.,2021;Lin et al.,2023;Zeng et al.,2023).
基金supported by the National Natural Science Foun-dation of China(51975017 and 52405448)the Human Resource Training Project(HRTP-[2022]-53)of Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM)the support by the China Postdoctoral Science Foundation(2024M750149 and GZC20240087).
文摘1.Introduction.In recent decades,the pursuit of miniaturization has been crucial in nanofabrication,fostering innovation,and enabling novel applications in chip manufacturing,nanophotonics,and quantum devices[1,2].Advancements in nanofabrication technology are driven by the demand for higher component density and performance,necessitating precise material processing in atmospheric environments.
基金the National Key R&D Program of China(No.2023YFE0208700)National Natural Sci-ence Foundation of China(No.92163109 and 52072095)+7 种基金Shenzhen Science and Technology Program(No.RCJC20231211090000001,GXWD20231129101105001)the National Natural Science Foundation of China(No.52205590)the Natural Science Foundation of Jiangsu Province(No.BK20220834)the Start-up Research Fund of Southeast University(No.RF1028623098)the State Key Laboratory of Robotics and Systems(HIT)(No.SKLRS-2024-KF-11)National Natural Science Foundation of China(No.52202348)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515011491)Shenzhen Science and Technology Program(Nos.GXWD20220818224716001,KJZD20231023100302006).
文摘Due to the small size,active mobility,and intrinsic softness,miniature soft robots hold promising po-tentials in reaching the deep region inside living bodies otherwise inaccessible with compelling agility,adaptability and safety.Various materials and actuation strategies have been developed for creating soft robots,among which,ferromagnetic soft materials that self-actuate in response to external magnetic fields have attracted worldwide attention due to their remote controllability and excellent compatibil-ity with biological tissues.This review presents comprehensive and systematic research advancements in the design,fabrication,and applications of ferromagnetic soft materials for miniature robots,providing in-sights into their potential use in biomedical fields and beyond.The programming strategies of ferromag-netic soft materials are summarized and classified,including mold-assisted programming,3D printing-assisted programming,microassembly-assisted programming,and magnetization reprogramming.Each approach possesses unique advantages in manipulating the magnetic responsiveness of ferromagnetic soft materials to achieve outstanding actuation and deformation performances.We then discuss the biomedi-cal applications of ferromagnetic soft material-based soft robots(e.g.,minimally invasive surgery,targeted delivery,and tissue engineering),highlighting their potentials in revolutionizing biomedical technologies.This review also points out the current challenges and provides insights into future research directions,which we hope can serve as a useful reference for the development of next-generation adaptive miniature robots.
基金Supported by the Fundamental Research Funds for the Central Universities(ZYGX2021J008)。
文摘A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,and this new structure enables a planar integrated transition from microstrip lines to ultra-thin cavity filters,thereby reducing the size of the transition structure and achieving miniaturization.The structure includes a conventional tapered microstrip transition structure,which guides the electromagnetic field from the microstrip line to the reduced-height dielectric-filled waveguide,and an air-filled matching cavity which is placed between the dielectric-filled waveguide and the ultra-thin cavity filter.The heights of the microstrip line,the dielectric-filled waveguide and the ultra-thin cavity filter are the same,enabling seamless integration within a planar radio-frequency(RF)circuit.To facilitate testing,mature finline transition structures are integrated at both ends of the microstrip line during fabrications.The simulation results of the fabricated microstrip to ultra-thin cavity filter transition with the finline transition structure,with a passband of 91.5-96.5 GHz,has an insertion loss of less than 1.9 dB and a return loss lower than-20 dB.And the whole structure has also been measured which achieves an insertion loss less than 2.6 dB and a return loss lower than-15 dB within the filter's passband,including the additional insertion loss introduced by the finline transitions.Finally,a W-band compact up-conversion module is designed,and the test results show that after using the proposed structure,the module achieves 95 dBc suppression of the 84 GHz local oscillator.It is also demonstrated that the structure proposed in this letter achieves miniaturization of the system integration without compromising the filter performance.
基金National Natural Science Foundation of China,No.42471185,No.T2192952National Key Research and Development Program of China,No.2022YFF0801502。
文摘The paleoenvironmental changes and adaptation strategies of hominins during the Late Pleistocene are crucial for understanding the evolution,dispersal,and behavioral shifts of early modern humans.Despite South China's significance as a nexus for hominin dispersal and handaxe technology diffusion,quantitative reconstructions of paleoenvironments linked to archaeological records remain scarce.The Sandinggai site(96.6-13.3 ka BP)in central South China,with its well-preserved stratigraphy and abundant lithic artefacts,is notable for providing valuable insights.In this study,quantitative reconstruction of the vegetation succession and climate change sequences at the site was conducted using palynological and isotopic data.The results indicated a shift from a warm-temperate evergreen and deciduous broadleaf mixed forest to a temperate deciduous broadleaf forest,with the climate transitioning from warm and humid to cooler and drier conditions.During the early phase,an increase in lithic production suggested favorable conditions for hominin survival.In the later phase,decreased lithic production and the replacement of large handaxe tools by smaller flake tools,indicated that hominins adapted to the cooler,drier climate and more open landscapes through lithic miniaturization.These findings highlight the environment-driven adaptation of lithic technology and hominin behavior,thereby shedding light on human survival adaptation strategies.
文摘This article presents a compact crab-shaped reconfigurable antenna(CSRA)designed for 5G sub-6 GHz wireless applications. The antenna achieves enhanced gain in a miniaturized form factor by incorporating a hexagonal split-ring structure controlled via two radio frequency(RF) positive-intrinsicnegative(PIN) diodes(BAR64-02V). While the antenna is primarily designed to operate at 3.50 GHz for sub-6 GHz 5G applications, RF switching enables the CSRA to cover a broader frequency spectrum, including the S-band, X-band, and portions of the Ku-band. The proposed antenna offers several advantages: It is low-cost(fabricated on an FR-4 substrate), compact(achieving 64.07% size reduction compared to conventional designs), and features both frequency and gain reconfigurability through digitally controlled PIN diode switching. The reflection coefficients of the antenna, both without diodes and across all four switching states, were experimentally validated in the laboratory using a Keysight Field Fox microwave analyzer(N9916A, 14 GHz). The simulated radiation patterns and gain characteristics closely matched the measured values, demonstrating an excellent agreement. This study bridges the gap between traditional and next-generation antenna designs by offering a compact,cost-effective, and high-performance solution for multiband, reconfigurable wireless communication systems. The integration of double-split-ring resonators and dynamic reconfigurability makes the proposed antenna a strong candidate for various applications, including S-band and X-band systems, as well as the emerging lower 6G band(7.125 GHz–8.400 GHz).
文摘Over the past three decades,micro/nano science and technology have experienced rapid advancements as new materials and advanced devices have increasingly evolved towards high levels of integration and miniaturization.In this context,mechanical properties have emerged as critical parameters for evaluating the operational performance and longevity of materials and devices at the micro/nanoscale.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20220813)the Fundamental Research Funds for the Central Universities(2242023K40014).
文摘Underwater robots have emerged as key tools for marine exploration because of their unique ability to traverse and navigate underwater regions,which pose challenges or dangers to human expeditions.Miniature underwater robots are widely employed in marine science,resource surveys,seabed geological investigations,and marine life observations,owing to their compact size,minimal noise,and agile move-ment.In recent years,researchers have developed diverse miniature underwater robots inspired by bion-ics and other disciplines,leading to many landmark achievements such as centimeter-level wireless control,movement speeds up to hundreds of millimeters per second,underwater three-dimensional motion capabilities,robot swarms,and underwater operation robots.This article offers an overview of the actuation methods and locomotion patterns utilized by miniature underwater robots and assesses the advantages and disadvantages of each method.Furthermore,the challenges confronting currently available miniature underwater robots are summarized,and future development trends are explored.
基金supported by the National Key Technologies R&D Program of China(Grant No.2023YFC2415900)the National Natural Science Foundation of China(Grant Nos.62373182 and 52405619)+2 种基金the China Postdoctoral Science Foundation(Grant No.2024M751300)supported by the Shenzhen Science and Technology Program(Grant No.JCYJ20241202125417024)Guangdong Basic and Applied Basic Research Foundation(Grant No.2024A1515011915).
文摘Adhesive patches offer an effective approach for wound closure,making them highly suitable for biomedical applications.However,conventional patches often face limitations such as dual-sided adhesion,lack of shape adaptability,and limited maneuverability,which restrict their applications in deeper tissues.In this paper,we develop a magnetic patch robot(PatchBot),for targeted Janus adhesion with tissues.The PatchBot features a unique triple-layer structure,with adhesive,shape-morphing,and anti-adhesive layers,each fulfilling roles to support targeted attachment,enable shape transformation,and prevent unwanted adhesion to surrounding tissues.The Janus adhesion of the PatchBot was extensively demonstrated across a variety of tissues.A localized near-infrared(NIR)laser irradiation was used to induce programmable shape transformations.Magnetic actuation of the PatchBot for targeted adhesion was successfully demonstrated in ex vivo porcine stomach tissue.NIR light-activated shape-morphing and multimodal magnetic actuation significantly enhance its maneuverability and adaptability in confined in vivo environments while ensuring the structural integrity of the adhesive surface during deployment.This proof-of-concept study demonstrates the feasibility of using PatchBot for targeted wound adhesion,showing its potential for minimally invasive,precision therapies in complex in vivo environments.
基金the financial support from the Research Institute for Advanced Manufacturing(RIAM)of The Hong Kong Polytechnic University(project Nos.1-CD9F and 1-CDK3)the Research Grants Council(RGC)of Hong Kong(project Nos.25200424 and 15206223)+2 种基金the GuangDong Basic and Applied Basic Research Foundation(project No.2023A1515110709)the Startup fund(project No.1-BE9L)of the Hong Kong Polytechnic Universitysupported by grant from the Research Committee of the Hong Kong Polytechnic University under student account code RN5Y.
文摘Inspired by bacterial motility mechanisms,Magnetic Helical Miniature Robots(MHMRs)exhibit promising applications in biomedical fields due to their efficient locomotion and compatibility with biological tissues.In this review,we systematically survey the basics of MHMRs,from propulsion mechanism,magnetization and control methods to biomedical applications,aiming to provide readers with an easily understandable overview and fundamental knowledge on implementing MHMRs.The MHMRs are actuated by rotating magnetic fields,achieving steering and rotation through magnetic torque,and converting rotation into forward motion through the helical structure.Magnetization methods for MHMRs are reviewed into three types:attaching magnets,magnetic coatings,and magnetic powder doping.Additionally,this review discusses the control methods for MHMRs,covering imaging techniques,path tracking control—including classical control algorithms and increasingly popular learning-based methods,and swarm control.Subsequently,a comprehensive survey is conducted on the biomedical applications of MHMRs in the treatment of vascular diseases,drug delivery,cell delivery,and their integration with catheters.We finally provide a perspective about future challenges in MHMR research,including enhancing functional design capabilities,developing swarm-assisted independent control mechanisms,refining in vivo imaging techniques,and ensuring robust biocompatibility for safe medical use.
基金the Shaanxi Provincial Key Research and Development Program(No.2020GY-040)。
文摘Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In order to further reduce the size and improve the performance of the proposed filter,defected ground structure(DGS)has been implemented in the filter.Based on this structure,the volume of the inductor is reduced by 60%eficiently compared with the inductor without DGS,and the Q-factor is increased up to 257%compared with the traditional multilayer spiral inductor.The measured results indicate that the designed filter has a very sharp stopband,an insertion loss of 2.3dB,and a return loss of 18.6dB in the passband.The whole volume of the fabricated filter is 0.032入_(g)×0.05入_(g)×0.00075入_(g),where Ag is the guided wavelength of the center frequency.The proposed filter is easily integrated into radio-frequency/microwave circuitry at a low manufacturing cost,especially wireless communication.
文摘Over the past three decades,there has been increasing interest in miniaturized percutaneous nephrolithotomy(mPCNL)techniques featuring smaller tracts as they offer potential solutions to mitigate complications associated with standard PCNL(sPCNL).However,despite this growing acceptance and recognition of its benefits,unresolved controversies and acknowledged limitations continue to impede widespread adoption due to a lack of consensus on optimal perioperative management strategies and procedural tips and tricks.In response to these challenges,an international panel comprising experts from the International Alliance of Urolithiasis(IAU)took on the task of compiling an expert consensus document on mPCNL procedures aimed at providing urologists with a comprehensive clinical framework for practice.This endeavor involved conducting a systematic literature review to identify research gaps(RGs),which formed the foundation for developing a structured questionnaire survey.Subsequently,a two-round modified Delphi survey was implemented,culminating in a group meeting to generate final evidence-based comments.All 64 experts completed the second-round survey,resulting in a response rate of 100.0%.Fifty-eight key questions were raised focusing on mPCNLs within 4 main domains,including general information(13 questions),preoperative work-up(13 questions),procedural tips and tricks(19 questions),and postoperative evaluation and follow-up(13 questions).Additionally,9 questions evaluated the experts’experience with PCNLs.Consensus was reached on 30 questions after the second-round survey,while professional statements for the remaining 28 key questions were provided after discussion in an online panel meeting.mPCNL,characterized by a tract smaller than 18 Fr and an innovative lithotripsy technique,has firmly established itself as a viable and effective approach for managing upper urinary tract stones in both adults and pediatrics.It offers several advantages over sPCNL including reduced bleeding,fewer requirements for nephrostomy tubes,decreased pain,and shorter hospital stays.The series of detailed techniques presented here serve as a comprehensive guide for urologists,aiming to improve their procedural understanding and optimize patient outcomes.
基金pported by the National Natural Science Foundation of China(Grant Nos.12325409,12388102,12074398,and U2267204)the CAS Project for Young Scientists in Basic Research(Grant No.YSBR-060)the Shanghai Pilot Program for Basic Research,Chinese Academy of Sciences Shanghai Branch。
文摘A new on-chip light source configuration has been proposed,which utilizes the interaction between a microwave or laser and a dielectric nanopillar array to generate a periodic electromagnetic near-field and applies periodic transverse acceleration to relativistic electrons to generate high-energy photon radiation.The dielectric nanopillar array interacting with the driving field acts as an electron undulator,in which the near-field drives electrons to oscillate.When an electron beam propagates through this nanopillar array in this light source configuration,it is subjected to a periodic transverse near-field force and will radiate X-ray or evenγ-ray high-energy photons after a relativistic frequency up-conversion.Compared with the undulator which is based on the interaction between strong lasers and nanostructures to generate a plasmonic near-field,this configuration is less prone to damage during operation.
基金financially supported by the National Science and Technology Innovation 2030 Major Program(Grant Nos.2022ZD0211903,2022ZD0212100,2021ZD0202205 for R.W.)the National Natural Science Foundation of China(Grant Nos.32201130 for R.W.+3 种基金62125501,12025402 for S.X.)the National Key R&D Program of China(Grant Nos.2022YFA1404700 for S.X.,2023YFC3402604,2023YFF1501100 for A.W.)the Beijing Natural Science Foundation(Grant No.Z240013 for R.W.)the Shenzhen Fundamental Research Project(Grant No.JCYJ20241202123729038 for S.X.).
文摘Miniaturized two-photon microscopes(m2PMs)enable high-resolution,deep-brain imaging in freely behaving animals.However,the trade-offs among weight,form factor,and optical performance in conventional refractive objectives present major obstacles to achieving large field-of-view(FOV),high-resolution imaging in weightsensitive or multiregion applications.Metalenses offer ultralight,high-NA,aberration-corrected alternatives,but face persistent challenges,including restricted FOV,off-axis aberrations,and dual-band optimization for two-photon imaging.Here,we present Meta-m2PM 2.0,a 1.06 g headpiece featuring a compound metalens architecture with a two-stage imaging design that decouples scanning and focusing.We designed and fabricated a large-angle(±12°)metalens-based scan lens and a high-NA(0.48)dual-layer metalens-based objective,both derived from our established polarization-insensitive Si_(3)N_(4)meta-atom library co-optimized for focusing and transmission at 920 nm excitation and 500–560 nm fluorescence collection.Meta-m2PM 2.0 achieves a 350×330μm^(2)FOV(>50×that of Meta-m2PM 1.0),with 1.17μm lateral and 19.85μm axial resolution at the center,while maintaining>80%lateral resolution uniformity across the FOV,and extending imaging depth to 210μm(~3×deeper).We demonstrate dendritic imaging in head-fixed awake mice and,to our knowledge,the first metalens-based two-photon calcium imaging in freely behaving mice with a high signal-to-noise ratio,paving the way for ultralight multiregion neuroimaging and compact nonlinear microendoscopy.
基金supported by the Scientific Research Innovation Capability Support Project for Young Faculty,China(No.ZYGXQNJSKYCXNLZCXM-D1)the National Natural Science Foundation of China(No.52272384).
文摘Flapping-Wing Micro Air Vehicles(FMAVs)are compact and agile,capable of accessing narrow spaces that conventional vehicles struggle to reach,such as ruins,caves,or the interiors of complex structures,making them ideal tools for reconnaissance and rescue missions.1 However,the operation of FMAVs relies on coordinating multiple forces with different scaling effects,posing challenges to miniaturization design.
文摘Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.
