Acute kidney injury(AKI)is a prevalent clinical syndrome characterized by a rapid loss of renal filtration function,with high incidence and mortality rates that are steadily rising.AKI not only affects the shortterm p...Acute kidney injury(AKI)is a prevalent clinical syndrome characterized by a rapid loss of renal filtration function,with high incidence and mortality rates that are steadily rising.AKI not only affects the shortterm prognosis of patients but also considerably raises the risk of progression to chronic kidney disease and end-stage renal disease,making it a significant threat to human health.Nanomedicine offers innovative therapeutic strategies for AKI and shows considerable potential in its treatment.This review comprehensively summarizes the application of nanomedicines in AKI therapy,with a particular focus on recent advances in the development of antioxidant,anti-inflammatory,and combined nanomedicine-based therapies targeting oxidative stress and inflammation,two primary pathological features of AKI.Additionally,this review also summarizes recent progress in AKI model construction to facilitate a better understanding and investigation of AKI.Overall,the review provides insights into innovative nanomedicine application in the effective treatment of AKI,hoping to provide new ideas for the clinical treatment of AKI.展开更多
Peri-implant diseases are characterized by the resorption of hard tissue and the inflammation of soft tissue.Epigenetics refers to alterations in the expression of genes that are not encoded in the DNA sequence,influe...Peri-implant diseases are characterized by the resorption of hard tissue and the inflammation of soft tissue.Epigenetics refers to alterations in the expression of genes that are not encoded in the DNA sequence,influencing diverse physiological activities,including immune response,inflammation,and bone metabolism.Epigenetic modifications can lead to tissue-specific gene expression variations among individuals and may initiate or exacerbate inflammation and disease predisposition.However,the impact of these factors on peri-implantitis remains inconclusive.To address this gap,we conducted a comprehensive review to investigate the associations between epigenetic mechanisms and peri-implantitis,specifically focusing on DNA methylation and microRNAs(miRNAs or miRs).We searched for relevant literature on PubMed,Web of Science,Scopus,and Google Scholar with keywords including“epigenetics,”“peri-implantitis,”“DNA methylation,”and“microRNA.”DNA methylation and miRNAs present a dynamic epigenetic mechanism operating around implants.Epigenetic modifications of genes related to inflammation and osteogenesis provide a new perspective for understanding how local and environmental factors influence the pathogenesis of peri-implantitis.In addition,we assessed the potential application of DNA methylation and miRNAs in the prevention,diagnosis,and treatment of peri-implantitis,aiming to provide a foundation for future studies to explore potential therapeutic targets and develop more effective management strategies for this condition.These findings also have broader implications for understanding the pathogenesis of other inflammation-related oral diseases like periodontitis.展开更多
Chronic exposure to coplanar polychlorinated biphenyls（PCBs）,a potent inducer of toxic reactive oxygen species（ROS）,in the environment and food can cause liver diseases.It remains unknown whether caffeic acid deri...Chronic exposure to coplanar polychlorinated biphenyls（PCBs）,a potent inducer of toxic reactive oxygen species（ROS）,in the environment and food can cause liver diseases.It remains unknown whether caffeic acid derivatives（CADs） exerted protective effect on PCB-induced hepatotoxicity.We sought to evaluate the activities of 3CADs on PCB169-induced oxidative stress and DNA damage in the liver.Male ICR mice were administered with1 μmol/mL PCB169 at 5 mL/kg body weight for 2 weeks.The mice were given CADs by gastric gavage for 3weeks.We found that PCB169 decreased the growth rate and reduced the levels of superoxide dismutase（SOD）,glutathione（GSH） and GSH peroxidase（GPx）.It increased the liver weight,malondialdehyde（MDA）and 8-hydroxy-2＇-deoxyguanosine（8-OHdG） levels and CYPlAl activity in the liver tissues and plasma of mice（P〈0.05）.Pretreatment of mice with CADs restored the above parameters to normal levels.There was a synergistic protective effect between CADs in preventing MDA and 8-OHdG formation and inducing CYPlAl and phase II metabolism enzyme（SOD,GPx） activities（P〈0.05）.In conclusion,PCB169 induced hepatotoxicity and pretreatment with CADs had synergistic protective effects on liver damage.展开更多
As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and ...As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and life style of university students.When this mode combines the characteristics and functions of shared bikes,it has a great impact on the awareness and motivation of work-out of university students.Supported by Internet technology,shared bikes meet the need of people that they can use them at any time,which is new and innovative to the university students.This article provides university students with shared bike service in campus by analyzing the influence of“Internet+shared bike”on health and sports of university students.It will promote the effective application of shared bikes.展开更多
As a powerful non-destructive and label-free detection technology,surface-enhanced Raman scattering(SERS)has been widely used in environmental-pollutant detection,biological-tissue sensing,molecular fingerprint analys...As a powerful non-destructive and label-free detection technology,surface-enhanced Raman scattering(SERS)has been widely used in environmental-pollutant detection,biological-tissue sensing,molecular fingerprint analysis and so on.Different from the traditional SERS substrates represented by noble metals and semiconductors,herein,we report a new highly sensitive SERS substrate material with high stability,biocompatibility,and low cost,namely nucleusfree two-dimensional electron gas(2DEG)Ti3C2 monolayer nanosheets.The highly crystalline monolayer Ti3C2 nanosheets with clean surface are synthesized by an improved chemical exfoliation and microwave heating method.The unique structure of nucleus-free-2DEG in Ti3C2 monolayer provides an ideal transport channel without nuclear scattering,which makes the highly crystalline monolayer Ti3C2 nanosheets achieve a Raman enhanced factor of 3.82×108 and a 10-11 level detection limit for typical environmental pollutants such as azo dyes,trichlorophenol,and bisphenol A.Singlemolecule imaging is also realized on the surface of the Ti3C2 monolayers,which may be the first time that approximate single-molecule imaging has been achieved on a non-noblemetal SERS substrates.Preliminary toxicological experiments show that the cytotoxicity of this material is very low.Considering the facile synthesis,high biocompatibility,low cost and high chemical stability of carbide nanosheets,these Ti3C2 monolayer nanosheets show significant promise for the design and fabrication of flexible SERS substrates for the sensing of trace substances with ultrahigh sensitivity.展开更多
Optical neural networks (ONNs), enabling low latency and high parallel data processing withoutelectromagnetic interference, have become a viable player for fast and energy-efficient processing andcalculation to meet t...Optical neural networks (ONNs), enabling low latency and high parallel data processing withoutelectromagnetic interference, have become a viable player for fast and energy-efficient processing andcalculation to meet the increasing demand for hash rate. Photonic memories employing nonvolatile phase-change materials could achieve zero static power consumption, low thermal cross talk, large-scale, andhigh-energy-efficient photonic neural networks. Nevertheless, the switching speed and dynamic energyconsumption of phase-change material-based photonic memories make them inapplicable for in situ training.Here, by integrating a patch of phase change thin film with a PIN-diode-embedded microring resonator,a bifunctional photonic memory enabling both 5-bit storage and nanoseconds volatile modulation wasdemonstrated. For the first time, a concept is presented for electrically programmable phase-changematerial-driven photonic memory integrated with nanosecond modulation to allow fast in situ training and zerostatic power consumption data processing in ONNs. ONNs with an optical convolution kernel constructedby our photonic memory theoretically achieved an accuracy of predictions higher than 95% when testedby the MNIST handwritten digit database. This provides a feasible solution to constructing large-scalenonvolatile ONNs with high-speed in situ training capability.展开更多
Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing appl...Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing applications.Despite significant progress in integrated optical filters,the FSR-free filter with a tunable narrow-band,high out-of-band rejection,and large fabrication tolerance has rarely been demonstrated.In this paper,we propose an exact and robust design method for add-drop filters(ADFs)with an FSR-free operation capability,a sub-nanometer optical bandwidth,and a high out-of-band rejection(OBR)ratio.The achieved filter has a 3-dB bandwidth of<0.5 nm and an OBR ratio of 21.5 dB within a large waveband of 220 nm,which to the best of our knowledge,is the largest-FSR ADF demonstrated on a silicon photonic platform.The filter exhibits large tunability of 12.3 nm with a heating efficiency of 97 pm/mW and maintains the FSR-free feature in the whole tuning process.In addition,we fabri-cated a series of ADFs with different periods,which all showed reliable and excellent performances.展开更多
Osteoarthritis(OA)progresses due to the excessive generation of reactive oxygen and nitrogen species(ROS/RNS)and abnormal ATP energy metabolism related to the oxidative phosphorylation pathway in the mitochondria.High...Osteoarthritis(OA)progresses due to the excessive generation of reactive oxygen and nitrogen species(ROS/RNS)and abnormal ATP energy metabolism related to the oxidative phosphorylation pathway in the mitochondria.Highly active single-atom nanozymes(SAzymes)can help regulate the redox balance and have shown their potential in the treatment of inflammatory diseases.In this study,we innovatively utilised ligand-mediated strategies to chelate Pt^(4+)with modified g-C_(3)N_(4)byπ-πinteraction to prepare g-C_(3)N_(4)-loaded Pt single-atom(Pt SA/C_(3)N_(4))nanozymes that serve as superoxide dismutase(SOD)/catalase(CAT)mimics to scavenge ROS/RNS and regulate mitochondrial ATP production,ultimately delaying the progression of OA.Pt SA/C_(3)N_(4)exhibited a high loading of Pt single atoms(2.45 wt%),with an excellent photothermal conversion efficiency(54.71%),resulting in tunable catalytic activities under near-infrared light(NIR)irradiation.Interestingly,the Pt-N_(6) active centres in Pt SA/C_(3)N_(4)formed electron capture sites for electron holes,in which g-C_(3)N_(4)regulated the d-band centre of Pt,and the N-rich sites transferred electrons to Pt,leading to the enhanced adsorption of free radicals and thus higher SOD-and CAT-like activities compared with pure g-C_(3)N_(4)and g-C_(3)N_(4)-loaded Pt nanoparticles(Pt NPs/C_(3)N_(4)).Based on the use of H_(2)O_(2)-induced chondrocytes to simulate ROS-injured cartilage in vitro and an OA joint model in vivo,the results showed that Pt SA/C_(3)N_(4)could reduce oxidative stress-induced damage,protect mitochondrial function,inhibit inflammation progression,and rebuild the OA microenvironment,thereby delaying the progression of OA.In particular,under NIR light irradiation,Pt SA/C_(3)N_(4)could help reverse the oxidative stress-induced joint cartilage damage,bringing it closer to the state of the normal cartilage.Mechanistically,Pt SA/C_(3)N_(4)regulated the expression of mitochondrial respiratory chain complexes,mainly NDUFV2 of complex 1 and MT-ATP6 of ATP synthase,to reduce ROS/RNS and promote ATP production.This study provides novel insights into the design of artificial nanozymes for treating oxidative stress-induced inflammatory diseases.展开更多
In recent years,the nuclear norm minimization(NNM)as a convex relaxation of the rank minimization has attracted great research interest.By assigning different weights to singular values,the weighted nuclear norm minim...In recent years,the nuclear norm minimization(NNM)as a convex relaxation of the rank minimization has attracted great research interest.By assigning different weights to singular values,the weighted nuclear norm minimization(WNNM)has been utilized in many applications.However,most of the work on WNNM is combined with the l 2-data-fidelity term,which is under additive Gaussian noise assumption.In this paper,we introduce the L1-WNNM model,which incorporates the l 1-data-fidelity term and the regularization from WNNM.We apply the alternating direction method of multipliers(ADMM)to solve the non-convex minimization problem in this model.We exploit the low rank prior on the patch matrices extracted based on the image non-local self-similarity and apply the L1-WNNM model on patch matrices to restore the image corrupted by impulse noise.Numerical results show that our method can effectively remove impulse noise.展开更多
基金supported by the National Natural Science Foundation of China(Nos.82272147,32271450,U21A20417,31930067,82472138,32200323)the Science and Technology Project of Sichuan Province(Nos.2023YFS0118,2024YFFK0322)the China Postdoctoral Science Foundation(No.2023M732144)。
文摘Acute kidney injury(AKI)is a prevalent clinical syndrome characterized by a rapid loss of renal filtration function,with high incidence and mortality rates that are steadily rising.AKI not only affects the shortterm prognosis of patients but also considerably raises the risk of progression to chronic kidney disease and end-stage renal disease,making it a significant threat to human health.Nanomedicine offers innovative therapeutic strategies for AKI and shows considerable potential in its treatment.This review comprehensively summarizes the application of nanomedicines in AKI therapy,with a particular focus on recent advances in the development of antioxidant,anti-inflammatory,and combined nanomedicine-based therapies targeting oxidative stress and inflammation,two primary pathological features of AKI.Additionally,this review also summarizes recent progress in AKI model construction to facilitate a better understanding and investigation of AKI.Overall,the review provides insights into innovative nanomedicine application in the effective treatment of AKI,hoping to provide new ideas for the clinical treatment of AKI.
基金supported by the Basic Public Welfare Research Project of Zhejiang Province(No.LGF22H140007)the Research and Development Project of Stomatology Hospital Affiliated to Zhejiang University School of Medicine(No.RD2022JCXK01)+1 种基金the National Natural Science Foundation of China(No.82301072)the Postdoctoral Science Foundation of China(Nos.2021TQ0277 and 2022M722741)。
文摘Peri-implant diseases are characterized by the resorption of hard tissue and the inflammation of soft tissue.Epigenetics refers to alterations in the expression of genes that are not encoded in the DNA sequence,influencing diverse physiological activities,including immune response,inflammation,and bone metabolism.Epigenetic modifications can lead to tissue-specific gene expression variations among individuals and may initiate or exacerbate inflammation and disease predisposition.However,the impact of these factors on peri-implantitis remains inconclusive.To address this gap,we conducted a comprehensive review to investigate the associations between epigenetic mechanisms and peri-implantitis,specifically focusing on DNA methylation and microRNAs(miRNAs or miRs).We searched for relevant literature on PubMed,Web of Science,Scopus,and Google Scholar with keywords including“epigenetics,”“peri-implantitis,”“DNA methylation,”and“microRNA.”DNA methylation and miRNAs present a dynamic epigenetic mechanism operating around implants.Epigenetic modifications of genes related to inflammation and osteogenesis provide a new perspective for understanding how local and environmental factors influence the pathogenesis of peri-implantitis.In addition,we assessed the potential application of DNA methylation and miRNAs in the prevention,diagnosis,and treatment of peri-implantitis,aiming to provide a foundation for future studies to explore potential therapeutic targets and develop more effective management strategies for this condition.These findings also have broader implications for understanding the pathogenesis of other inflammation-related oral diseases like periodontitis.
基金supported by the National Natural Science Foundation of China(No:81072338)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (2010)
文摘Chronic exposure to coplanar polychlorinated biphenyls（PCBs）,a potent inducer of toxic reactive oxygen species（ROS）,in the environment and food can cause liver diseases.It remains unknown whether caffeic acid derivatives（CADs） exerted protective effect on PCB-induced hepatotoxicity.We sought to evaluate the activities of 3CADs on PCB169-induced oxidative stress and DNA damage in the liver.Male ICR mice were administered with1 μmol/mL PCB169 at 5 mL/kg body weight for 2 weeks.The mice were given CADs by gastric gavage for 3weeks.We found that PCB169 decreased the growth rate and reduced the levels of superoxide dismutase（SOD）,glutathione（GSH） and GSH peroxidase（GPx）.It increased the liver weight,malondialdehyde（MDA）and 8-hydroxy-2＇-deoxyguanosine（8-OHdG） levels and CYPlAl activity in the liver tissues and plasma of mice（P〈0.05）.Pretreatment of mice with CADs restored the above parameters to normal levels.There was a synergistic protective effect between CADs in preventing MDA and 8-OHdG formation and inducing CYPlAl and phase II metabolism enzyme（SOD,GPx） activities（P〈0.05）.In conclusion,PCB169 induced hepatotoxicity and pretreatment with CADs had synergistic protective effects on liver damage.
文摘As the economy and technology keep growing,the mode of shared bikes gains popularity under these circumstances.At the current period,university students become fond of using shared bikes,which changes body health and life style of university students.When this mode combines the characteristics and functions of shared bikes,it has a great impact on the awareness and motivation of work-out of university students.Supported by Internet technology,shared bikes meet the need of people that they can use them at any time,which is new and innovative to the university students.This article provides university students with shared bike service in campus by analyzing the influence of“Internet+shared bike”on health and sports of university students.It will promote the effective application of shared bikes.
基金support from the Science Foundation of Chinese Academy of Inspection and Quarantine(2019JK004)the National Key Research and Development Program of China(2017YFF0210003)the high performance computing center of Qufu Normal University。
文摘As a powerful non-destructive and label-free detection technology,surface-enhanced Raman scattering(SERS)has been widely used in environmental-pollutant detection,biological-tissue sensing,molecular fingerprint analysis and so on.Different from the traditional SERS substrates represented by noble metals and semiconductors,herein,we report a new highly sensitive SERS substrate material with high stability,biocompatibility,and low cost,namely nucleusfree two-dimensional electron gas(2DEG)Ti3C2 monolayer nanosheets.The highly crystalline monolayer Ti3C2 nanosheets with clean surface are synthesized by an improved chemical exfoliation and microwave heating method.The unique structure of nucleus-free-2DEG in Ti3C2 monolayer provides an ideal transport channel without nuclear scattering,which makes the highly crystalline monolayer Ti3C2 nanosheets achieve a Raman enhanced factor of 3.82×108 and a 10-11 level detection limit for typical environmental pollutants such as azo dyes,trichlorophenol,and bisphenol A.Singlemolecule imaging is also realized on the surface of the Ti3C2 monolayers,which may be the first time that approximate single-molecule imaging has been achieved on a non-noblemetal SERS substrates.Preliminary toxicological experiments show that the cytotoxicity of this material is very low.Considering the facile synthesis,high biocompatibility,low cost and high chemical stability of carbide nanosheets,these Ti3C2 monolayer nanosheets show significant promise for the design and fabrication of flexible SERS substrates for the sensing of trace substances with ultrahigh sensitivity.
基金supported by the National Key Research and Development Program of China (2019YFB2203002 and 2021YFB2801300)National Natural Science Foundation of China (62105287, 91950204, and 61975179)Zhejiang Provincial Natural Science Foundation (LD22F040002)
文摘Optical neural networks (ONNs), enabling low latency and high parallel data processing withoutelectromagnetic interference, have become a viable player for fast and energy-efficient processing andcalculation to meet the increasing demand for hash rate. Photonic memories employing nonvolatile phase-change materials could achieve zero static power consumption, low thermal cross talk, large-scale, andhigh-energy-efficient photonic neural networks. Nevertheless, the switching speed and dynamic energyconsumption of phase-change material-based photonic memories make them inapplicable for in situ training.Here, by integrating a patch of phase change thin film with a PIN-diode-embedded microring resonator,a bifunctional photonic memory enabling both 5-bit storage and nanoseconds volatile modulation wasdemonstrated. For the first time, a concept is presented for electrically programmable phase-changematerial-driven photonic memory integrated with nanosecond modulation to allow fast in situ training and zerostatic power consumption data processing in ONNs. ONNs with an optical convolution kernel constructedby our photonic memory theoretically achieved an accuracy of predictions higher than 95% when testedby the MNIST handwritten digit database. This provides a feasible solution to constructing large-scalenonvolatile ONNs with high-speed in situ training capability.
基金National Key Research and Development Program of China(2019YFB2203003)National Natural Science Foundation of China(62175202 and 91950204)+2 种基金Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2020R01005)the Open Research program of Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang ProvinceWestlake University(the start-up fund of Westlake University).
文摘Free-spectral-range(FSR)-free optical filters have always been a critical challenge for photonic integrated circuits.A high-performance FSR-free filter is highly desired for communication,spectroscopy,and sensing applications.Despite significant progress in integrated optical filters,the FSR-free filter with a tunable narrow-band,high out-of-band rejection,and large fabrication tolerance has rarely been demonstrated.In this paper,we propose an exact and robust design method for add-drop filters(ADFs)with an FSR-free operation capability,a sub-nanometer optical bandwidth,and a high out-of-band rejection(OBR)ratio.The achieved filter has a 3-dB bandwidth of<0.5 nm and an OBR ratio of 21.5 dB within a large waveband of 220 nm,which to the best of our knowledge,is the largest-FSR ADF demonstrated on a silicon photonic platform.The filter exhibits large tunability of 12.3 nm with a heating efficiency of 97 pm/mW and maintains the FSR-free feature in the whole tuning process.In addition,we fabri-cated a series of ADFs with different periods,which all showed reliable and excellent performances.
基金the support from the Guangxi Natural Science Foundation(No.2023GXNSFBA026020)Guangxi Scientific Research and Technological Development Foundation(Grant No.GuikeAB21220062)National Natural Science Foundation of China(Grant No.82160429,82360426,52301303,81960400).
文摘Osteoarthritis(OA)progresses due to the excessive generation of reactive oxygen and nitrogen species(ROS/RNS)and abnormal ATP energy metabolism related to the oxidative phosphorylation pathway in the mitochondria.Highly active single-atom nanozymes(SAzymes)can help regulate the redox balance and have shown their potential in the treatment of inflammatory diseases.In this study,we innovatively utilised ligand-mediated strategies to chelate Pt^(4+)with modified g-C_(3)N_(4)byπ-πinteraction to prepare g-C_(3)N_(4)-loaded Pt single-atom(Pt SA/C_(3)N_(4))nanozymes that serve as superoxide dismutase(SOD)/catalase(CAT)mimics to scavenge ROS/RNS and regulate mitochondrial ATP production,ultimately delaying the progression of OA.Pt SA/C_(3)N_(4)exhibited a high loading of Pt single atoms(2.45 wt%),with an excellent photothermal conversion efficiency(54.71%),resulting in tunable catalytic activities under near-infrared light(NIR)irradiation.Interestingly,the Pt-N_(6) active centres in Pt SA/C_(3)N_(4)formed electron capture sites for electron holes,in which g-C_(3)N_(4)regulated the d-band centre of Pt,and the N-rich sites transferred electrons to Pt,leading to the enhanced adsorption of free radicals and thus higher SOD-and CAT-like activities compared with pure g-C_(3)N_(4)and g-C_(3)N_(4)-loaded Pt nanoparticles(Pt NPs/C_(3)N_(4)).Based on the use of H_(2)O_(2)-induced chondrocytes to simulate ROS-injured cartilage in vitro and an OA joint model in vivo,the results showed that Pt SA/C_(3)N_(4)could reduce oxidative stress-induced damage,protect mitochondrial function,inhibit inflammation progression,and rebuild the OA microenvironment,thereby delaying the progression of OA.In particular,under NIR light irradiation,Pt SA/C_(3)N_(4)could help reverse the oxidative stress-induced joint cartilage damage,bringing it closer to the state of the normal cartilage.Mechanistically,Pt SA/C_(3)N_(4)regulated the expression of mitochondrial respiratory chain complexes,mainly NDUFV2 of complex 1 and MT-ATP6 of ATP synthase,to reduce ROS/RNS and promote ATP production.This study provides novel insights into the design of artificial nanozymes for treating oxidative stress-induced inflammatory diseases.
基金supported by the National Natural Science Foundation of China under grants U21A20455,61972265,11871348 and 11701388by the Natural Science Foundation of Guangdong Province of China under grant 2020B1515310008by the Educational Commission of Guangdong Province of China under grant 2019KZDZX1007.
文摘In recent years,the nuclear norm minimization(NNM)as a convex relaxation of the rank minimization has attracted great research interest.By assigning different weights to singular values,the weighted nuclear norm minimization(WNNM)has been utilized in many applications.However,most of the work on WNNM is combined with the l 2-data-fidelity term,which is under additive Gaussian noise assumption.In this paper,we introduce the L1-WNNM model,which incorporates the l 1-data-fidelity term and the regularization from WNNM.We apply the alternating direction method of multipliers(ADMM)to solve the non-convex minimization problem in this model.We exploit the low rank prior on the patch matrices extracted based on the image non-local self-similarity and apply the L1-WNNM model on patch matrices to restore the image corrupted by impulse noise.Numerical results show that our method can effectively remove impulse noise.
