Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)iso...Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.展开更多
The static sealing of underground gas storage(UGS),including the integrity of cap rocks and the stability of faults,is analyzed from a macro perspective using a comprehensive geological evaluation method.Changes in po...The static sealing of underground gas storage(UGS),including the integrity of cap rocks and the stability of faults,is analyzed from a macro perspective using a comprehensive geological evaluation method.Changes in pore structure,permeability,and mechanical strength of cap rocks under cyclic loads may impact the rock sealing integrity during the injection and recovery phases of UGS.In this work,the mechanical deformation and failure tests of rocks,as well as rock damage tests under alternating loads,are conducted to analyze the changes in the strength and permeability of rocks under multiple-cycle intense injection and recovery of UGS.Additionally,this study proposes an evaluation method for the dynamic sealing performance of UGS cap rocks under multi-cycle alternating loads.The findings suggest that the failure strength(70%)can be used as the critical value for rock failure,thus providing theoretical support for determining the upper limit of operating pressure and the number of injection-recovery cycles for the safe operation of a UGS system.展开更多
Kaolinite,as a mineral in fine coal,has an important influence on the flotation of coal particles.In this study,the effects of ultrafine kaolinite particles on the flotation recovery of coal particles were investigate...Kaolinite,as a mineral in fine coal,has an important influence on the flotation of coal particles.In this study,the effects of ultrafine kaolinite particles on the flotation recovery of coal particles were investigated.Flotation tests were carried out using a mixture of coal particles and different amounts of ultrafine kaolinite particles.Combined with the Stefan–Reynold theory,the effect of liquid film drainage rate between coal bubbles in a kaolinite suspension was calculated.The yield of flotation clean coal increases quickly with the increasing content of ultrafine kaolinite particles.The ultrafine kaolinite particles can reduce the surface tension of the suspension,weaken the bubble coalescence,and stabilize the structure of the froth layer.In addition,the ultrafine kaolinite particles increase the apparent viscosity of the flotation pulp slightly.It is concluded that the role of ultrafine kaolinite particles on the positive effect of froth properties conceals the negative effect on the liquid film drainage rate between coal particles and bubbles caused by the kaolinite particles,which ultimately leads to an increasing yield of clean coal with an increasing content of kaolinite particles.This study is important for understanding the influence of ultrafine kaolinite on coal particle flotation.展开更多
A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro pe...A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro perties,external quantum efficiency,the rmal stability and application perfo rmance of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+),by partially substituting Sr^(2+) with Ca^(2+)(x=0-0.2),were studied by various analytical techniques.When the Ca/Sr ratio of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) gradually increases,the emission peak of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) red-shiftes from 459 to 465 nm,corrected external quantum efficiency increases from 31.8% to 42.9%,and the thermal stability is also improved.The mechanism of the changes of the photoluminescence emission and excitation spectra,external quantum efficiency and thermal stability properties was also investigated in detail.In addition,a w-LED was fabricated by using SrLu_(2)O_(4):Ce^(3+)(blue),β-sialon:Eu^(2+)(green) and(Sr,Ca)AlSiN_(3):Eu^(2+)(red) phosphors combined with a 405 nm near-UV LED chip,and its color rendering index(CRI) reaches 96.0.When Sr_(0.8)Ca_(0.2)Lu_(2)O_(4):Ce^(3+) is applied as blue phosphor to substitute SrLu_(2)O_(4):Ce^(3+),the obtained w-LED devices have high luminous efficiency,and CRI greater than 95.0.These re sults show that the Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) can be potential blue phosphors for n-UV pumped high CRI w-LEDs application.展开更多
A series of non-rare earth Mn^(4+)-activated strontium aluminate phosphors Sr_(4)Al_(14)O_(25):Mn^(4+)co-doped with Sc^(3+)ions were successfully synthesized by a high-temperature solid-state reaction method.XRD resul...A series of non-rare earth Mn^(4+)-activated strontium aluminate phosphors Sr_(4)Al_(14)O_(25):Mn^(4+)co-doped with Sc^(3+)ions were successfully synthesized by a high-temperature solid-state reaction method.XRD result reveals that there is no introduction of additional phase but expansion of lattice with incorporation of Sc34 ions.Excitation and emission spectrum measurement shows that the synthesized phosphors can be efficiently excited by near-ultraviolet and blue light,and a deep red emission centered at 652 nm with a narrow full width at half maximum(FWHM)can be obtained,which is attributed to the transition^(2)E→^(4)A_(2)of Mn^(4+)ions.In addition,the crystal field strength parameter(Dq)and Racah parameters(B,C)and energies of states were calculated based on experimental data.Moreover,the luminous intensity of Sr_(4)Al_(14-x)SCxO_(25):Mn^(4+)is enhanced and increased by 60%compared with Mn^(4+)single incorporated sample at x=0.06.A phenomenon of redshift is observed in the excitation spectrum and discussed systematically.Finally,the mechanism of the positive effects with Sc^(3+)ions incorporated into lattice is discussed in detail.All the results suggest that the Sr_(4)Al_(13.94)Sc_(0.06)O_(25):Mn^(4+)phosphor will become one of the great candidates for backlight of LCD.展开更多
The influences of plastic deformation, aging treatment, and alloying elements on the texture of Cu-Cr-Zr alloys were ex- plored. The texture component and intensity of Cu-Cr-Zr alloys under various working conditions ...The influences of plastic deformation, aging treatment, and alloying elements on the texture of Cu-Cr-Zr alloys were ex- plored. The texture component and intensity of Cu-Cr-Zr alloys under various working conditions after aging treatment were characterized using the orientation distributing function （ODF）. The influence of Zr content on the texture of Cu-Cr-Zr alloys was also analyzed. The reduction pass and deformation level were primary factors influencing the texture. Rolling texture appeared in a rolled plate and the fibrous textures of {111} and {001} were detected after 80% deformation. Fibrous texture with a main constituent of {111} improved the tensile strength of the alloy wire. The texture contents of {110}〈331〉 and {110}〈112〉 were predominated, whereas, those of {113}〈332〉 and {112}〈111〉 were in the minority in the Cu-Cr-Zr alloy with a higher Zr content （〉0.5wt%）. However, in the samples with a lower Zr content （〈0.1wt%）, the texture contents of {113}〈332〉, {112}〈111〉, and {111}〈110〉 were in the majority.展开更多
Biography videos based on life performances of prominent figures in history aim to describe great mens' life.In this paper,a novel interactive video summarization for biography video based on multimodal fusion is ...Biography videos based on life performances of prominent figures in history aim to describe great mens' life.In this paper,a novel interactive video summarization for biography video based on multimodal fusion is proposed,which is a novel approach of visualizing the specific features for biography video and interacting with video content by taking advantage of the ability of multimodality.In general,a story of movie progresses by dialogues of characters and the subtitles are produced with the basis on the dialogues which contains all the information related to the movie.In this paper,JGibbsLDA is applied to extract key words from subtitles because the biography video consists of different aspects to depict the characters' whole life.In terms of fusing keywords and key-frames,affinity propagation is adopted to calculate the similarity between each key-frame cluster and keywords.Through the method mentioned above,a video summarization is presented based on multimodal fusion which describes video content more completely.In order to reduce the time spent on searching the interest video content and get the relationship between main characters,a kind of map is adopted to visualize video content and interact with video summarization.An experiment is conducted to evaluate video summarization and the results demonstrate that this system can formally facilitate the exploration of video content while improving interaction and finding events of interest efficiently.展开更多
Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was invest...Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid shift.These two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.展开更多
Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 20...Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 2013, patients with NLUTD were prospectively randomized and assigned to either a bladder irrigation group or a no bladder irrigation group. Bladder irrigations were performed twice a week by urologists. Patients were followed up at 6 months respectively. Primary outcomes were Incontinence-Specific Quality-of-Life Instrument (I-QoL), the rate incidences of bladder stone. All adverse events were also noted. Results: A total of 80 eligible patients participated and 78 (97.5%) patients (bladder irrigation, n = 39;no bladder irrigation, n = 39) completed 24 weeks of follow-up. Out of the 78 patients, 19 (24.3%) developed bladder stones. All occurred in no bladder irrigation group. In 8 of the 19 patients (42.1%), stones were only detected by cystoscopy. The bladder stones were mostly thin with an eggshell appearance (78.95% for diameter of stone < 5 mm, 84.21% for volume of bladder stone < 0.2 cm3). Bladder stones were removed by vigorous bladder irrigation guided by ultrasound (73.68%) or endoscopic lithotripsy (26.32%). The I-QOL was significantly better in the bladder irrigation group than in no bladder irrigation group at weeks 6, 12, 18, and 24 of follow-up. Conclusion: Bladder irrigation may be more effective and safer than no bladder irrigation for reducing the morbidity of bladder stone in spinal cord injury patients.展开更多
Deception detection plays a crucial role in criminal investigation.Videos contain a wealth of information regarding apparent and physiological changes in individuals,and thus can serve as an effective means of decepti...Deception detection plays a crucial role in criminal investigation.Videos contain a wealth of information regarding apparent and physiological changes in individuals,and thus can serve as an effective means of deception detection.In this paper,we investigate video-based deception detection considering both apparent visual features such as eye gaze,head pose and facial action unit(AU),and non-contact heart rate detected by remote photoplethysmography(rPPG)technique.Multiple wrapper-based feature selection methods combined with the K-nearest neighbor(KNN)and support vector machine(SVM)classifiers are employed to screen the most effective features for deception detection.We evaluate the performance of the proposed method on both a self-collected physiological-assisted visual deception detection(PV3D)dataset and a public bag-oflies(BOL)dataset.Experimental results demonstrate that the SVM classifier with symbiotic organisms search(SOS)feature selection yields the best overall performance,with an area under the curve(AUC)of 83.27%and accuracy(ACC)of 83.33%for PV3D,and an AUC of 71.18%and ACC of 70.33%for BOL.This demonstrates the stability and effectiveness of the proposed method in video-based deception detection tasks.展开更多
This paper presents the method of reinforcing main girder of reinforced concrete cable-stayed bridge with prestressed steel strands.To verify the effectiveness of external prestressed strand reinforcement method.Stati...This paper presents the method of reinforcing main girder of reinforced concrete cable-stayed bridge with prestressed steel strands.To verify the effectiveness of external prestressed strand reinforcement method.Static load tests and health monitoring-based assessment were carried out before and after reinforcement.Field load test shows that the deflection and stress values of the main girder are reduced by 10%~20%after reinforcement,and the flexural strength and stiffness of the strengthened beam are improved.The deflection and strain data of health monitoring of the specified section are collected.The deflection of the second span is 4 mm~10 mm,the strain range of the upper edge of the second span is-10με~-40με,and the strain range of the lower edge is 30με~75με.These values show the deflection and strain values fluctuate within a prescribed range,verifying the safety of the bridge.The reinforcement method of prestressed steel strand is feasible and effective.It can provide reference basis for the application of external prestressed strand reinforcement technology in similar projects.展开更多
Valley topological photonic crystals(TPCs),which are robust against local disorders and structural defects,have attracted great research interest,from theoretical verification to technical applications.However,previou...Valley topological photonic crystals(TPCs),which are robust against local disorders and structural defects,have attracted great research interest,from theoretical verification to technical applications.However,previous works mostly focused on the robustness of topologically protected edge states and little attention was paid to the importance of the photonic bandgaps(PBGs),which hinders the implementation of various multifrequency functional topological photonic devices.Here,by systematically studying the relationship between the degree of symmetry breaking and the working bandwidth of the edge states,we present spoof surface plasmon polariton valley TPCs with broadband edge states and engineered PBGs,where the operation frequency is easy to adjust.Furthermore,by connecting valley TPCs operating at different frequencies,a broadband multifunctional frequency-dependent topological photonic device with selectively directional light transmission is fabricated and experimentally demonstrated,achieving the functions of wavelength division multiplexing and add–drop multiplexing.We provide an effective and insightful method for building multi-frequency topological photonic devices.展开更多
Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, a...Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices.展开更多
Recent moiréconfigurations provide a new platform for tunable and sensitive photonic responses,as their enhanced light–matter interactions originate from the relative displacement or rotation angle in a stacking...Recent moiréconfigurations provide a new platform for tunable and sensitive photonic responses,as their enhanced light–matter interactions originate from the relative displacement or rotation angle in a stacking bilayer or multilayer periodic array.However,previous findings are mostly focused on atomically thin condensed matter,with limitations on the fabrication of multilayer structures and the control of rotation angles.Structured microwave moiréconfigurations are still difficult to realize.Here,we design a novel moiréstructure,which presents unprecedented capability in the manipulation of light–matter interactions.Based on the effective medium theory and S-parameter retrieval process,the rotation matrix is introduced into the dispersion relation to analyze the underlying physical mechanism,where the permittivity tensor transforms from a diagonal matrix to a fully populated one,whereas the permeability tensor evolves from a unit matrix to a diagonal one and finally becomes fully filled,so that the electromagnetic responses change drastically as a result of stacking and rotation.Besides,the experiment and simulation results reveal hybridization of eigenmodes,drastic manipulation of surface states,and magic angle properties by controlling the mutual rotation angles between two isolated layers.Here,not only a more precisely controllable bilayer hyperbolic metasurface is introduced to moiréphysics,the findings also open up a new avenue to realize flat bands at arbitrary frequencies,which shows great potential in active engineering of surface waves and designing multifunctional plasmonic devices.展开更多
Rectangular inclined channels prove promising for solid classification based on the principle of parti- cle differential sedimentation. In the present work, we investigated the motion characteristics of binary solids ...Rectangular inclined channels prove promising for solid classification based on the principle of parti- cle differential sedimentation. In the present work, we investigated the motion characteristics of binary solids in a modified fluidised bed （mFB） with inclined plates. We developed a theoretical model for the particle motion behaviour that accounts for the average solid volume fraction in the inclined channel and interactions between binary solids. The experimental system was designed to be consistent with the idealised theoretical arrangements to maximise the measurement accuracy. The experimental particles were mixtures of silica sand particles of sizes 425-710 i^m and 710-880/~m, respectively. Specifically, we investigated the flow hydrodynamics of the binary suspension in terms of the settling length of both par- ticle species and the bed expansion behaviour. We also analysed the utilisation factor and the separation efficiency of the mFB. The results showed that the average solid volume fraction in the inclined channel fluctuated slightly for a given total solid inventory. The utilisation factor and separation efficiency of the system decreased when increasing either the fluidisation velocity or the solid inventory. The prediction results were in good agreement with the experimental data with an absolute deviation of less than 15%.展开更多
Free manipulation of electromagnetic waves in the terahertz(THz)band based on metasurface functional devices has been the focus of research in recent years.Among these devices,active metasurfaces have generated extens...Free manipulation of electromagnetic waves in the terahertz(THz)band based on metasurface functional devices has been the focus of research in recent years.Among these devices,active metasurfaces have generated extensive research interest due to their reconfigurability.In this work,we demonstrate a mechanically reconfigurable THz polarization converter that consists of two parallel transmissive metasurfaces with a tunable spacing.By mechanically adjusting the coupling strength between the metasurfaces,the orthogonal polarization conversion of the incident linearly polarized THz waves can be tuned.Specifically,the device can be tuned from efficient dual-frequency orthogonal polarization conversion to efficient single-frequency orthogonal polarization conversion.After a gradual decrease in efficiency,it is finally changed to a low transmission state as the gap distance increases from 150 to 800μm.We theoretically analyze the tuning process under different spacings and experimentally verify it using a vector network analyzer.Our proposed design is straightforward and robust,with the potential to find wide applications in THz science and technology.展开更多
Conversion from free-space waves to surface plasmons has been well studied as a key aspect of plasmonics.In particular,efficient coupling and propagation of surface plasmons via phase gradient metasurfaces are of grea...Conversion from free-space waves to surface plasmons has been well studied as a key aspect of plasmonics.In particular,efficient coupling and propagation of surface plasmons via phase gradient metasurfaces are of great current research interest.Hereby,we demonstrate a terahertz metacoupler based on a bilayer bright–dark mode coupling structure attaining near-perfect conversion efficiency(exceeding 95%)without considering absorption loss of the materials and maintaining a high conversion level even when the area of the excitation region changes.To validate our design,a fabricated metacoupler was assessed by scanning near-field terahertz microscopy.Our findings could pave the way for developing high-performance plasmonic devices encompassing ultra-thin and compact functional devices for a diverse range of applications,especially within the realm of high-speed terahertz communications.展开更多
Zn-based biodegradable metals(BMs)are regarded as revolutionary biomaterials for bone implants.However,their clinical application is limited by insufficient mechanical properties,delayed in vivo degradation,and overdo...Zn-based biodegradable metals(BMs)are regarded as revolutionary biomaterials for bone implants.However,their clinical application is limited by insufficient mechanical properties,delayed in vivo degradation,and overdose-induced Zn^(2+)toxicity.Herein,innovative multi-material additive manufacturing(MMAM)is deployed to construct a Zn/titanium(Ti)hetero-structured composite.The biodegradation and biofunction of Zn exhibited intriguing characteristics in composites.A potential difference of about 300 mV naturally existed between Zn and Ti.This natural potential difference triggered galvanic coupling corrosion,resulting in 2.7 times accelerated degradation of Zn.The excess release of Zn^(2+)induced by accelerated degradation enhanced the antibacterial function.A voltage signal generated by the natural potential difference also promoted in vitro osteogenic differentiation through activating the PI3K-Akt signaling pathway,and inhibited the toxicity of overdose Zn^(2+)in vivo,significantly improving bone regeneration.Furthermore,MMAM technology allows for the specific region deployment of components.In the future,Ti and Zn could be respectively deployed in the primary and non-loadbearing regions of bone implants by structural designs,thereby achieving a functionally graded application to overcome the insufficient mechanical properties of Zn-based BMs.This work clarifies the functional optimization mechanism for multimetal bone implants,which possibly breaks the application dilemma of Zn-based BMs.展开更多
Medical image segmentation is critical for clinical diagnosis,but the scarcity of annotated data limits robust model training,making few-shot learning indispensable.Existing methods often suffer from two issues—perfo...Medical image segmentation is critical for clinical diagnosis,but the scarcity of annotated data limits robust model training,making few-shot learning indispensable.Existing methods often suffer from two issues—performance degradation due to significant inter-class variations in pathological structures,and overreliance on attention mechanisms with high computational complexity(O(n2)),which hinders the efficient modeling of long-range dependencies.In contrast,the state space model(SSM)offers linear complexity(O(n))and superior efficiency,making it a key solution.To address these challenges,we propose PPFFR(parallel prototype filter and feature refinement)for few-shot medical image segmentation.The proposed framework comprises three key modules.First,we propose the prototype refinement(PR)module to construct refined class subgraphs from encoder-extracted features of both support and query images,which generates support prototypes with minimized inter-class variation.We then propose the parallel prototype filter(PPF)module to suppress background interference and enhance the correlation between support and query prototypes.Finally,we implement the feature refinement(FR)module to further enhance segmentation accuracy and accelerate model convergence with SSM’s robust long-range dependency modeling capability,integrated with multi-head attention(MHA)to preserve spatial details.Experimental results on the Abd-MRI dataset demonstrate that FR with MHA outperforms FR alone in segmenting the left kidney,right kidney,liver,and spleen,and in terms of mean accuracy,confirming MHA’s role in improving precision.In extensive experiments conducted on three public datasets under the 1-way 1-shot setting,PPFFR achieves Dice scores of 87.62%,86.74%,and 79.71%separately,consistently surpassing state-of-the-art few-shot medical image segmentation methods.As the critical component,SSM ensures that PPFFR balances performance with efficiency.Ablation studies validate the effectiveness of the PR,PPF,and FR modules.The results indicate that explicit inter-class variation reduction and SSM-based feature refinement can enhance accuracy without heavy computational overhead.In conclusion,PPFFR effectively enhances inter-class consistency and computational efficiency for few-shot medical image segmentation.This work provides insights for few-shot learning in medical imaging and inspires lightweight architecture designs for clinical deployment.展开更多
基金supported by the NIH grants,R01 NS111801(to ZGZ)American Heart Association 16SDG29860003(to YZ)。
文摘Axonal remodeling is a critical aspect of ischemic brain repair processes and contributes to spontaneous functional recovery.Our previous in vitro study demonstrated that exosomes/small extracellular vesicles(sEVs)isolated from cerebral endothelial cells(CEC-sEVs)of ischemic brain promote axonal growth of embryonic cortical neurons and that microRNA 27a(miR-27a)is an elevated miRNA in ischemic CEC-sEVs.In the present study,we investigated whether normal CEC-sEVs engineered to enrich their levels of miR-27a(27a-sEVs)further enhance axonal growth and improve neurological outcomes after ischemic stroke when compared with treatment with non-engineered CEC-sEVs.27a-sEVs were isolated from the conditioned medium of healthy mouse CECs transfected with a lentiviral miR-27a expression vector.Small EVs isolated from CECs transfected with a scramble vector(Scra-sEVs)were used as a control.Adult male mice were subjected to permanent middle cerebral artery occlusion and then were randomly treated with 27a-sEVs or Scra-sEVs.An array of behavior assays was used to measure neurological function.Compared with treatment of ischemic stroke with Scra-sEVs,treatment with 27a-sEVs significantly augmented axons and spines in the peri-infarct zone and in the corticospinal tract of the spinal grey matter of the denervated side,and significantly improved neurological outcomes.In vitro studies demonstrated that CEC-sEVs carrying reduced miR-27a abolished 27a-sEV-augmented axonal growth.Ultrastructural analysis revealed that 27a-sEVs systemically administered preferentially localized to the pre-synaptic active zone,while quantitative reverse transcription-polymerase chain reaction and Western Blot analysis showed elevated miR-27a,and reduced axonal inhibitory proteins Semaphorin 6A and Ras Homolog Family Member A in the peri-infarct zone.Blockage of the Clathrin-dependent endocytosis pathway substantially reduced neuronal internalization of 27a-sEVs.Our data provide evidence that 27a-sEVs have a therapeutic effect on stroke recovery by promoting axonal remodeling and improving neurological outcomes.Our findings also suggest that suppression of axonal inhibitory proteins such as Semaphorin 6A may contribute to the beneficial effect of 27a-sEVs on axonal remodeling.
文摘The static sealing of underground gas storage(UGS),including the integrity of cap rocks and the stability of faults,is analyzed from a macro perspective using a comprehensive geological evaluation method.Changes in pore structure,permeability,and mechanical strength of cap rocks under cyclic loads may impact the rock sealing integrity during the injection and recovery phases of UGS.In this work,the mechanical deformation and failure tests of rocks,as well as rock damage tests under alternating loads,are conducted to analyze the changes in the strength and permeability of rocks under multiple-cycle intense injection and recovery of UGS.Additionally,this study proposes an evaluation method for the dynamic sealing performance of UGS cap rocks under multi-cycle alternating loads.The findings suggest that the failure strength(70%)can be used as the critical value for rock failure,thus providing theoretical support for determining the upper limit of operating pressure and the number of injection-recovery cycles for the safe operation of a UGS system.
文摘Kaolinite,as a mineral in fine coal,has an important influence on the flotation of coal particles.In this study,the effects of ultrafine kaolinite particles on the flotation recovery of coal particles were investigated.Flotation tests were carried out using a mixture of coal particles and different amounts of ultrafine kaolinite particles.Combined with the Stefan–Reynold theory,the effect of liquid film drainage rate between coal bubbles in a kaolinite suspension was calculated.The yield of flotation clean coal increases quickly with the increasing content of ultrafine kaolinite particles.The ultrafine kaolinite particles can reduce the surface tension of the suspension,weaken the bubble coalescence,and stabilize the structure of the froth layer.In addition,the ultrafine kaolinite particles increase the apparent viscosity of the flotation pulp slightly.It is concluded that the role of ultrafine kaolinite particles on the positive effect of froth properties conceals the negative effect on the liquid film drainage rate between coal particles and bubbles caused by the kaolinite particles,which ultimately leads to an increasing yield of clean coal with an increasing content of kaolinite particles.This study is important for understanding the influence of ultrafine kaolinite on coal particle flotation.
基金Project supported by the National Key Research and Development Program of China(2017YFB0404301)。
文摘A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro perties,external quantum efficiency,the rmal stability and application perfo rmance of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+),by partially substituting Sr^(2+) with Ca^(2+)(x=0-0.2),were studied by various analytical techniques.When the Ca/Sr ratio of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) gradually increases,the emission peak of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) red-shiftes from 459 to 465 nm,corrected external quantum efficiency increases from 31.8% to 42.9%,and the thermal stability is also improved.The mechanism of the changes of the photoluminescence emission and excitation spectra,external quantum efficiency and thermal stability properties was also investigated in detail.In addition,a w-LED was fabricated by using SrLu_(2)O_(4):Ce^(3+)(blue),β-sialon:Eu^(2+)(green) and(Sr,Ca)AlSiN_(3):Eu^(2+)(red) phosphors combined with a 405 nm near-UV LED chip,and its color rendering index(CRI) reaches 96.0.When Sr_(0.8)Ca_(0.2)Lu_(2)O_(4):Ce^(3+) is applied as blue phosphor to substitute SrLu_(2)O_(4):Ce^(3+),the obtained w-LED devices have high luminous efficiency,and CRI greater than 95.0.These re sults show that the Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) can be potential blue phosphors for n-UV pumped high CRI w-LEDs application.
基金Project supported by the National Key Research and Development Program of China(2017YFB0404301)the Team of Excellent Talent Development Project of Xicheng District,Beijing.
文摘A series of non-rare earth Mn^(4+)-activated strontium aluminate phosphors Sr_(4)Al_(14)O_(25):Mn^(4+)co-doped with Sc^(3+)ions were successfully synthesized by a high-temperature solid-state reaction method.XRD result reveals that there is no introduction of additional phase but expansion of lattice with incorporation of Sc34 ions.Excitation and emission spectrum measurement shows that the synthesized phosphors can be efficiently excited by near-ultraviolet and blue light,and a deep red emission centered at 652 nm with a narrow full width at half maximum(FWHM)can be obtained,which is attributed to the transition^(2)E→^(4)A_(2)of Mn^(4+)ions.In addition,the crystal field strength parameter(Dq)and Racah parameters(B,C)and energies of states were calculated based on experimental data.Moreover,the luminous intensity of Sr_(4)Al_(14-x)SCxO_(25):Mn^(4+)is enhanced and increased by 60%compared with Mn^(4+)single incorporated sample at x=0.06.A phenomenon of redshift is observed in the excitation spectrum and discussed systematically.Finally,the mechanism of the positive effects with Sc^(3+)ions incorporated into lattice is discussed in detail.All the results suggest that the Sr_(4)Al_(13.94)Sc_(0.06)O_(25):Mn^(4+)phosphor will become one of the great candidates for backlight of LCD.
文摘The influences of plastic deformation, aging treatment, and alloying elements on the texture of Cu-Cr-Zr alloys were ex- plored. The texture component and intensity of Cu-Cr-Zr alloys under various working conditions after aging treatment were characterized using the orientation distributing function （ODF）. The influence of Zr content on the texture of Cu-Cr-Zr alloys was also analyzed. The reduction pass and deformation level were primary factors influencing the texture. Rolling texture appeared in a rolled plate and the fibrous textures of {111} and {001} were detected after 80% deformation. Fibrous texture with a main constituent of {111} improved the tensile strength of the alloy wire. The texture contents of {110}〈331〉 and {110}〈112〉 were predominated, whereas, those of {113}〈332〉 and {112}〈111〉 were in the minority in the Cu-Cr-Zr alloy with a higher Zr content （〉0.5wt%）. However, in the samples with a lower Zr content （〈0.1wt%）, the texture contents of {113}〈332〉, {112}〈111〉, and {111}〈110〉 were in the majority.
基金Supported by the National Key Research and Development Plan(2016YFB1001200)the Natural Science Foundation of China(U1435220,61232013)Natural Science Research Projects of Universities in Jiangsu Province(16KJA520003)
文摘Biography videos based on life performances of prominent figures in history aim to describe great mens' life.In this paper,a novel interactive video summarization for biography video based on multimodal fusion is proposed,which is a novel approach of visualizing the specific features for biography video and interacting with video content by taking advantage of the ability of multimodality.In general,a story of movie progresses by dialogues of characters and the subtitles are produced with the basis on the dialogues which contains all the information related to the movie.In this paper,JGibbsLDA is applied to extract key words from subtitles because the biography video consists of different aspects to depict the characters' whole life.In terms of fusing keywords and key-frames,affinity propagation is adopted to calculate the similarity between each key-frame cluster and keywords.Through the method mentioned above,a video summarization is presented based on multimodal fusion which describes video content more completely.In order to reduce the time spent on searching the interest video content and get the relationship between main characters,a kind of map is adopted to visualize video content and interact with video summarization.An experiment is conducted to evaluate video summarization and the results demonstrate that this system can formally facilitate the exploration of video content while improving interaction and finding events of interest efficiently.
基金Project supported by the National Basic Research Program of China(2014CB643801)
文摘Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid shift.These two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.
文摘Objective: To assess the safety and efficacy of bladder irrigation for reducing the morbidity of bladder stones in patients with neurological lower urinary tract dysfunction (NLUTD). Methods: From June 2012 to July 2013, patients with NLUTD were prospectively randomized and assigned to either a bladder irrigation group or a no bladder irrigation group. Bladder irrigations were performed twice a week by urologists. Patients were followed up at 6 months respectively. Primary outcomes were Incontinence-Specific Quality-of-Life Instrument (I-QoL), the rate incidences of bladder stone. All adverse events were also noted. Results: A total of 80 eligible patients participated and 78 (97.5%) patients (bladder irrigation, n = 39;no bladder irrigation, n = 39) completed 24 weeks of follow-up. Out of the 78 patients, 19 (24.3%) developed bladder stones. All occurred in no bladder irrigation group. In 8 of the 19 patients (42.1%), stones were only detected by cystoscopy. The bladder stones were mostly thin with an eggshell appearance (78.95% for diameter of stone < 5 mm, 84.21% for volume of bladder stone < 0.2 cm3). Bladder stones were removed by vigorous bladder irrigation guided by ultrasound (73.68%) or endoscopic lithotripsy (26.32%). The I-QOL was significantly better in the bladder irrigation group than in no bladder irrigation group at weeks 6, 12, 18, and 24 of follow-up. Conclusion: Bladder irrigation may be more effective and safer than no bladder irrigation for reducing the morbidity of bladder stone in spinal cord injury patients.
基金National Natural Science Foundation of China(No.62271186)Anhui Key Project of Research and Development Plan(No.202104d07020005)。
文摘Deception detection plays a crucial role in criminal investigation.Videos contain a wealth of information regarding apparent and physiological changes in individuals,and thus can serve as an effective means of deception detection.In this paper,we investigate video-based deception detection considering both apparent visual features such as eye gaze,head pose and facial action unit(AU),and non-contact heart rate detected by remote photoplethysmography(rPPG)technique.Multiple wrapper-based feature selection methods combined with the K-nearest neighbor(KNN)and support vector machine(SVM)classifiers are employed to screen the most effective features for deception detection.We evaluate the performance of the proposed method on both a self-collected physiological-assisted visual deception detection(PV3D)dataset and a public bag-oflies(BOL)dataset.Experimental results demonstrate that the SVM classifier with symbiotic organisms search(SOS)feature selection yields the best overall performance,with an area under the curve(AUC)of 83.27%and accuracy(ACC)of 83.33%for PV3D,and an AUC of 71.18%and ACC of 70.33%for BOL.This demonstrates the stability and effectiveness of the proposed method in video-based deception detection tasks.
文摘This paper presents the method of reinforcing main girder of reinforced concrete cable-stayed bridge with prestressed steel strands.To verify the effectiveness of external prestressed strand reinforcement method.Static load tests and health monitoring-based assessment were carried out before and after reinforcement.Field load test shows that the deflection and stress values of the main girder are reduced by 10%~20%after reinforcement,and the flexural strength and stiffness of the strengthened beam are improved.The deflection and strain data of health monitoring of the specified section are collected.The deflection of the second span is 4 mm~10 mm,the strain range of the upper edge of the second span is-10με~-40με,and the strain range of the lower edge is 30με~75με.These values show the deflection and strain values fluctuate within a prescribed range,verifying the safety of the bridge.The reinforcement method of prestressed steel strand is feasible and effective.It can provide reference basis for the application of external prestressed strand reinforcement technology in similar projects.
基金supported by the National Natural Science Foundation of China(Grant Nos.62175180,62005193,11874245,and 12004425)the National Key Research and Development Program of China(Grant No.2017YFA0701004)the Natural Science Foundation of Jiangsu Province(Grant No.BK20200630).
文摘Valley topological photonic crystals(TPCs),which are robust against local disorders and structural defects,have attracted great research interest,from theoretical verification to technical applications.However,previous works mostly focused on the robustness of topologically protected edge states and little attention was paid to the importance of the photonic bandgaps(PBGs),which hinders the implementation of various multifrequency functional topological photonic devices.Here,by systematically studying the relationship between the degree of symmetry breaking and the working bandwidth of the edge states,we present spoof surface plasmon polariton valley TPCs with broadband edge states and engineered PBGs,where the operation frequency is easy to adjust.Furthermore,by connecting valley TPCs operating at different frequencies,a broadband multifunctional frequency-dependent topological photonic device with selectively directional light transmission is fabricated and experimentally demonstrated,achieving the functions of wavelength division multiplexing and add–drop multiplexing.We provide an effective and insightful method for building multi-frequency topological photonic devices.
基金National Basic Research Program of China(2014CB339800)National Natural Science Foundation of China(NSFC)(61420106006,61422509,61605143,61622505,61675145,61735012)+2 种基金Program for Changjiang Scholars and Innovative Research Team in University(IRT13033)Major National Development Project of Scientific Instruments and Equipment(2011YQ150021)Guangxi Key Laboratory of Automatic Detecting Technology and Instruments(YQ17203)
文摘Dielectric metasurfaces have achieved great success in realizing high-efficiency wavefront control in the optical and infrared ranges. Here, we experimentally demonstrate several efficient, polarization-independent, all-silicon dielectric metasurfaces in the terahertz regime. The metasurfaces are composed of cylindrical silicon pillars on a silicon substrate, which can be easily fabricated using etching technology for semiconductors. By locally tailoring the diameter of the pillars, full control over abrupt phase changes can be achieved. To show the controlling ability of the metasurfaces, an anomalous deflector, three Bessel beam generators, and three vortex beam generators are fabricated and characterized. We also show that the proposed metasurfaces can be easily combined to form composite devices with extended functionalities. The proposed controlling method has promising applications in developing low-loss, ultra-compact spatial terahertz modulation devices.
基金National Natural Science Foundation of China(62175180, 61875150, 61805129, 62005193, 11874245)National Key Research and Development Program of China(2017YFA0701004)Central Government Guides Local Science and Technology Development Fund Projects(YDZJSX2021B011)
文摘Recent moiréconfigurations provide a new platform for tunable and sensitive photonic responses,as their enhanced light–matter interactions originate from the relative displacement or rotation angle in a stacking bilayer or multilayer periodic array.However,previous findings are mostly focused on atomically thin condensed matter,with limitations on the fabrication of multilayer structures and the control of rotation angles.Structured microwave moiréconfigurations are still difficult to realize.Here,we design a novel moiréstructure,which presents unprecedented capability in the manipulation of light–matter interactions.Based on the effective medium theory and S-parameter retrieval process,the rotation matrix is introduced into the dispersion relation to analyze the underlying physical mechanism,where the permittivity tensor transforms from a diagonal matrix to a fully populated one,whereas the permeability tensor evolves from a unit matrix to a diagonal one and finally becomes fully filled,so that the electromagnetic responses change drastically as a result of stacking and rotation.Besides,the experiment and simulation results reveal hybridization of eigenmodes,drastic manipulation of surface states,and magic angle properties by controlling the mutual rotation angles between two isolated layers.Here,not only a more precisely controllable bilayer hyperbolic metasurface is introduced to moiréphysics,the findings also open up a new avenue to realize flat bands at arbitrary frequencies,which shows great potential in active engineering of surface waves and designing multifunctional plasmonic devices.
文摘Rectangular inclined channels prove promising for solid classification based on the principle of parti- cle differential sedimentation. In the present work, we investigated the motion characteristics of binary solids in a modified fluidised bed （mFB） with inclined plates. We developed a theoretical model for the particle motion behaviour that accounts for the average solid volume fraction in the inclined channel and interactions between binary solids. The experimental system was designed to be consistent with the idealised theoretical arrangements to maximise the measurement accuracy. The experimental particles were mixtures of silica sand particles of sizes 425-710 i^m and 710-880/~m, respectively. Specifically, we investigated the flow hydrodynamics of the binary suspension in terms of the settling length of both par- ticle species and the bed expansion behaviour. We also analysed the utilisation factor and the separation efficiency of the mFB. The results showed that the average solid volume fraction in the inclined channel fluctuated slightly for a given total solid inventory. The utilisation factor and separation efficiency of the system decreased when increasing either the fluidisation velocity or the solid inventory. The prediction results were in good agreement with the experimental data with an absolute deviation of less than 15%.
基金supported by the National Natural Science Foundation of China(Nos.61935015,62375203,62335011,62075158,62025504,62175083)the Yunnan Expert Workstation(No.202205AF150008)+2 种基金the Independent Innovation Fund of Tianjin University(No.2024XPD-0012)the NaturalScienceFoundationofJilinProvince(No.20230101359JC)the Fundamental Research Funds for Central Universities。
文摘Free manipulation of electromagnetic waves in the terahertz(THz)band based on metasurface functional devices has been the focus of research in recent years.Among these devices,active metasurfaces have generated extensive research interest due to their reconfigurability.In this work,we demonstrate a mechanically reconfigurable THz polarization converter that consists of two parallel transmissive metasurfaces with a tunable spacing.By mechanically adjusting the coupling strength between the metasurfaces,the orthogonal polarization conversion of the incident linearly polarized THz waves can be tuned.Specifically,the device can be tuned from efficient dual-frequency orthogonal polarization conversion to efficient single-frequency orthogonal polarization conversion.After a gradual decrease in efficiency,it is finally changed to a low transmission state as the gap distance increases from 150 to 800μm.We theoretically analyze the tuning process under different spacings and experimentally verify it using a vector network analyzer.Our proposed design is straightforward and robust,with the potential to find wide applications in THz science and technology.
基金National Natural Science Foundation of China(62375203,62075158,62135008,62335011,61935015,62025504)Yunnan Expert Workstation(202205AF150008)。
文摘Conversion from free-space waves to surface plasmons has been well studied as a key aspect of plasmonics.In particular,efficient coupling and propagation of surface plasmons via phase gradient metasurfaces are of great current research interest.Hereby,we demonstrate a terahertz metacoupler based on a bilayer bright–dark mode coupling structure attaining near-perfect conversion efficiency(exceeding 95%)without considering absorption loss of the materials and maintaining a high conversion level even when the area of the excitation region changes.To validate our design,a fabricated metacoupler was assessed by scanning near-field terahertz microscopy.Our findings could pave the way for developing high-performance plasmonic devices encompassing ultra-thin and compact functional devices for a diverse range of applications,especially within the realm of high-speed terahertz communications.
基金funded by National Key Research and Development Program of China(2022YFB4600302)National Natural Science Foundation of China(52104368,82151312,82272493)+4 种基金Fundamental Research Funds for the Central Universities(FRF-IDRY-23-011)Beijing Natural Science Foundation(L222110,L212066)Beijing Science Nova Program(20220484155)Capital’s Funds for Health Improvement and Research(CFH 2024-2-5051)Autonomous Innovation Science Foundation of the Fourth Medical Center of PLA General Hospital(2024-4ZX-MS-15).
文摘Zn-based biodegradable metals(BMs)are regarded as revolutionary biomaterials for bone implants.However,their clinical application is limited by insufficient mechanical properties,delayed in vivo degradation,and overdose-induced Zn^(2+)toxicity.Herein,innovative multi-material additive manufacturing(MMAM)is deployed to construct a Zn/titanium(Ti)hetero-structured composite.The biodegradation and biofunction of Zn exhibited intriguing characteristics in composites.A potential difference of about 300 mV naturally existed between Zn and Ti.This natural potential difference triggered galvanic coupling corrosion,resulting in 2.7 times accelerated degradation of Zn.The excess release of Zn^(2+)induced by accelerated degradation enhanced the antibacterial function.A voltage signal generated by the natural potential difference also promoted in vitro osteogenic differentiation through activating the PI3K-Akt signaling pathway,and inhibited the toxicity of overdose Zn^(2+)in vivo,significantly improving bone regeneration.Furthermore,MMAM technology allows for the specific region deployment of components.In the future,Ti and Zn could be respectively deployed in the primary and non-loadbearing regions of bone implants by structural designs,thereby achieving a functionally graded application to overcome the insufficient mechanical properties of Zn-based BMs.This work clarifies the functional optimization mechanism for multimetal bone implants,which possibly breaks the application dilemma of Zn-based BMs.
基金Project supported by the National Natural Science Foundation of China(No.62272027)the Beijing Natural Science Foundation(No.4232012)the Henan Postdoctoral Foundation(No.335614)。
文摘Medical image segmentation is critical for clinical diagnosis,but the scarcity of annotated data limits robust model training,making few-shot learning indispensable.Existing methods often suffer from two issues—performance degradation due to significant inter-class variations in pathological structures,and overreliance on attention mechanisms with high computational complexity(O(n2)),which hinders the efficient modeling of long-range dependencies.In contrast,the state space model(SSM)offers linear complexity(O(n))and superior efficiency,making it a key solution.To address these challenges,we propose PPFFR(parallel prototype filter and feature refinement)for few-shot medical image segmentation.The proposed framework comprises three key modules.First,we propose the prototype refinement(PR)module to construct refined class subgraphs from encoder-extracted features of both support and query images,which generates support prototypes with minimized inter-class variation.We then propose the parallel prototype filter(PPF)module to suppress background interference and enhance the correlation between support and query prototypes.Finally,we implement the feature refinement(FR)module to further enhance segmentation accuracy and accelerate model convergence with SSM’s robust long-range dependency modeling capability,integrated with multi-head attention(MHA)to preserve spatial details.Experimental results on the Abd-MRI dataset demonstrate that FR with MHA outperforms FR alone in segmenting the left kidney,right kidney,liver,and spleen,and in terms of mean accuracy,confirming MHA’s role in improving precision.In extensive experiments conducted on three public datasets under the 1-way 1-shot setting,PPFFR achieves Dice scores of 87.62%,86.74%,and 79.71%separately,consistently surpassing state-of-the-art few-shot medical image segmentation methods.As the critical component,SSM ensures that PPFFR balances performance with efficiency.Ablation studies validate the effectiveness of the PR,PPF,and FR modules.The results indicate that explicit inter-class variation reduction and SSM-based feature refinement can enhance accuracy without heavy computational overhead.In conclusion,PPFFR effectively enhances inter-class consistency and computational efficiency for few-shot medical image segmentation.This work provides insights for few-shot learning in medical imaging and inspires lightweight architecture designs for clinical deployment.
