To address the challenges of high complexity,poor real-time performance,and low detection rates for small target vehicles in existing vehicle object detection algorithms,this paper proposes a real-time lightweight arc...To address the challenges of high complexity,poor real-time performance,and low detection rates for small target vehicles in existing vehicle object detection algorithms,this paper proposes a real-time lightweight architecture based on You Only Look Once(YOLO)v5m.Firstly,a lightweight upsampling operator called Content-Aware Reassembly of Features(CARAFE)is introduced in the feature fusion layer of the network to maximize the extraction of deep-level features for small target vehicles,reducing the missed detection rate and false detection rate.Secondly,a new prediction layer for tiny targets is added,and the feature fusion network is redesigned to enhance the detection capability for small targets.Finally,this paper applies L1 regularization to train the improved network,followed by pruning and fine-tuning operations to remove redundant channels,reducing computational and parameter complexity and enhancing the detection efficiency of the network.Training is conducted on the VisDrone2019-DET dataset.The experimental results show that the proposed algorithmreduces parameters and computation by 63.8% and 65.8%,respectively.The average detection accuracy improves by 5.15%,and the detection speed reaches 47 images per second,satisfying real-time requirements.Compared with existing approaches,including YOLOv5m and classical vehicle detection algorithms,our method achieves higher accuracy and faster speed for real-time detection of small target vehicles in edge computing.展开更多
Dihydroorotate dehydrogenase(DHODH)is a central enzyme of the de novo pyrimidine biosynthesis pathway and is a promising drug target for the treatment of cancer and autoimmune diseases.This study presents the identifi...Dihydroorotate dehydrogenase(DHODH)is a central enzyme of the de novo pyrimidine biosynthesis pathway and is a promising drug target for the treatment of cancer and autoimmune diseases.This study presents the identification of a potent DHODH inhibitor by proteomic profiling.Cell-based screening revealed that NPD723,which is reduced to H-006 in cells,strongly induces myeloid differentiation and inhibits cell growth in HL-60 cells.H-006 also suppressed the growth of various cancer cells.Proteomic profiling of NPD723-treated cells in ChemProteoBase showed that NPD723 was clustered with DHODH inhibitors.H-006 potently inhibited human DHODH activity in vitro,whereas NPD723 was approximately 400 times less active than H-006.H-006-induced cell death was rescued by the addition of the DHODH product orotic acid.Moreover,metabolome analysis revealed that H-006 treatment promotes marked accumulation of the DHODH substrate dihydroorotic acid.These results suggest that NPD723 is reduced in cells to its active metabolite H-006,which then targets DHODH and suppresses cancer cell growth.Thus,H-006-related drugs represent a potentially powerful treatment for cancer and other diseases.展开更多
Apoptosis has been considered as the only form of regulated cell death for a long time. However, a novel form of programmed cell death called necroptosis was recently reported. The process of necroptosis is regulated ...Apoptosis has been considered as the only form of regulated cell death for a long time. However, a novel form of programmed cell death called necroptosis was recently reported. The process of necroptosis is regulated and plays a critical role in the occurrence and development of multiple human diseases. Thus,the study on the molecular mechanism of necroptosis and its effective inhibitors has been an attractive field for researchers. Herein, we introduce the molecular mechanism of necroptosis and focus on the literature about necroptosis drug screening in recent years. In addition, the identification of the critical drug targets of the necroptosis is also discussed.展开更多
MicroRNAs (miRNAs) are a class of ~22 nucleotides long non coding RNA molecules which play an important role in gene regulation at the post transcriptional level. The conserved nature of miRNAs provides the basis of n...MicroRNAs (miRNAs) are a class of ~22 nucleotides long non coding RNA molecules which play an important role in gene regulation at the post transcriptional level. The conserved nature of miRNAs provides the basis of new miRNA identification through homology search. In an attempt to identify new conserved miRNAs in tea, previously known plant miRNAs were used for searching their homolog in a tea Expressed Sequence Tags and full length nucleotide sequence database. The sequences showing homolog no more than four mismatches were predicted for their fold back structures and passed through a series of filtration criteria, finally led us to identify 13 conserved miRNAs in tea belonging to 9 miRNA families. A total of 37 potential target genes in Arabidopsis were identified subsequently for 7 miRNA families based on their sequence complementarity which encode transcription factors (8%), enzymes (30%) and transporters (14%) as well as other proteins involved in physiological and metabolic processes (48%). Overall, our findings will accelerate the way for further researches of miRNAs and their functions in tea.展开更多
Ship type identification is an important part of electronic reconnaissance. However, in the existing methods, such as statistical-based methods and fuzzy-mathematics-based methods, the information acquired by the pass...Ship type identification is an important part of electronic reconnaissance. However, in the existing methods, such as statistical-based methods and fuzzy-mathematics-based methods, the information acquired by the passive sensor is not fully utilized, and there is a certain ambiguity in the assignment relationship of the emitters-ship. They can’t conclude the accurate and reliable assignment relationship of the emitters-ship. Therefore, this paper proposes a comprehensive correlation discriminant method to obtain a more reliable and comprehensive emitters-ship assignment, and then uses information entropy method to identify the type of the target ship on the basis of this association and assign the credibility. The simulation results show that this algorithm can effectively solve the problem of target ship type identification using the information of multi-passive sensors.展开更多
On the basis of target transfer function with the early time and late time response together, a method for solving the feature coefficients of target is investigated by utilizing approximation theory and method. Then,...On the basis of target transfer function with the early time and late time response together, a method for solving the feature coefficients of target is investigated by utilizing approximation theory and method. Then, the feature coefficients are classified by the minimum distance criterion to identify targets automatically.展开更多
In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to syn...In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to synthesize discrimination waveform,so the poles extractionprocedure is not required.Particularly,it can successfully operate on the case that the poles ofthe target are weakly dependent on the aspect angle.展开更多
In this paper, by using the biorthogonal quadrature filters, the biorthogonal mul-tiresolution analysis of finite dimension space equipped with inner product and the fast discrete wavelet transform (FDWT) are construc...In this paper, by using the biorthogonal quadrature filters, the biorthogonal mul-tiresolution analysis of finite dimension space equipped with inner product and the fast discrete wavelet transform (FDWT) are constructed. The dual transform method is proposed and the radar data storage is reduced by it. The method of choosing the wavelet coefficients, and the methods of correlation and nearest neighbor classification in wavelet domain based on the compressed data, are presented. The experimental results of the classification, using the high resolution range returns from six kinds of aircrafts, show that the methods of transform, compression and recognition are efficient.展开更多
In order to improve the identification capability of ultra wide-band radar,this paper in-troduces a step-variant multiresolution approach for the time-shift parameter estimation. Subsequently,combining with the approa...In order to improve the identification capability of ultra wide-band radar,this paper in-troduces a step-variant multiresolution approach for the time-shift parameter estimation. Subsequently,combining with the approach,a Geometrical Theory of Diffraction(GTD) model-based time-shift Invariant method to target identification using Matching Pursuits and Likelihood Ratio Test(IMPLRT) is developed. Simulation results using measured scattering signatures of two targets in an ultra wide-band chamber are presented contrasting the performance of the IMPLRT to the Wang's MPLRT technique.展开更多
OBJECTIVE Our group mainly focuses on the target identification and pharmacological mechanism study of TCM.We deeply identified the direct targets of the active ingredients in TCM using molecule probe-'Target Fish...OBJECTIVE Our group mainly focuses on the target identification and pharmacological mechanism study of TCM.We deeply identified the direct targets of the active ingredients in TCM using molecule probe-'Target Fishing' technology in chemical biology,and explored the related signaling pathways to explain the traditional efficiency of TCM.METHODS We synthesized biotin-tagged mole.cule probe by connecting biotin tag to TCM active molecule using PGE as a linker.Then,the biotintagged molecule probe was bound to the surface of solid beads by strong biotin-avidin interaction.Thus,the molecule probe-bound beads were mixed with cell lysates to capture the potential targets and identified by MS.RESULTS Our study found that SA which was an anti-inflammatory compound.could selectively bind to IMPDH2 in microglial cells,and SA showed weaker anti-inflammatory effect on IMPDH2-knock down microglial cells,suggesting IMPDH2 as a key anti-inflammatory target for SA.Ad.ditionally,handelin was a key anti-inflammatory compound.We identified the target protein of handelin as Hsp70 from microglial cells using target pull-down technology.Moreover,handelin showed weaker anti-inflammatory effect on Hsp70-knock down microglial cells,revealing that Hsp70 was the direct antiinflammatory target of handelin.CONCLUSION Our study provided methodology references for TCM target identification in the future,and also showed a new insight for exploring the pharmacological mechanism of TCM active ingredients.More importantly,we can perform scientific annotation for TCM efficiency by clarifying the biological functions of each target protein,showing important significance on modernization and internationalization of TCM.展开更多
This paper proposes a hybrid method, called CNOP–4 DVar, for the identification of sensitive areas in targeted observations, which takes the advantages of both the conditional nonlinear optimal perturbation(CNOP) and...This paper proposes a hybrid method, called CNOP–4 DVar, for the identification of sensitive areas in targeted observations, which takes the advantages of both the conditional nonlinear optimal perturbation(CNOP) and four-dimensional variational assimilation(4 DVar) methods. The proposed CNOP–4 DVar method is capable of capturing the most sensitive initial perturbation(IP), which causes the greatest perturbation growth at the time of verification;it can also identify sensitive areas by evaluating their assimilation effects for eliminating the most sensitive IP. To alleviate the dependence of the CNOP–4 DVar method on the adjoint model, which is inherited from the adjoint-based approach, we utilized two adjointfree methods, NLS-CNOP and NLS-4 DVar, to solve the CNOP and 4 DVar sub-problems, respectively. A comprehensive performance evaluation for the proposed CNOP–4 DVar method and its comparison with the CNOP and CNOP–ensemble transform Kalman filter(ETKF) methods based on 10 000 observing system simulation experiments on the shallow-water equation model are also provided. The experimental results show that the proposed CNOP–4 DVar method performs better than the CNOP–ETKF method and substantially better than the CNOP method.展开更多
Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent bioc...Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.展开更多
Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associat...Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.展开更多
Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of ...Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of the most destructive pests of palms in the world. Nowadays, control methods revolve around treatments based on chemicals, biotechnological systems using semi-chemicals or the development of the sterile insect technique (hardly sustainable at this time) and biological control. Biological control as the use of natural microorganisms, extracted products from microorganisms or genetically improved to resist or eliminate of pathogens. Our aim was to evaluate the entomopathogenicity of indigenous Beauveria bassiana and Metarhizium anisopliae obtained in Gaza strip against larvae and adults of R. ferrugineus in order to identify indigenous strains potentially suitable for Red Palm Weevil biological control. B. bassiana & M. anisopliae were isolated from larvae and adult dead of RPW from different position of Gaza strip. Morphological analysis of the isolated fungi and molecular identification was determined using PCR technique. Also, the efficiency of the isolated fungi were evaluated under lab conditions and optimized as a biological agent. On the anther hand, the ability of treated RPW male to infect females is examined and calculated using Abbott's formula. Our results showed that the B. bassiana and M. anisopliae exhibited a good biological control agent against larvae and adults of RPW. The pathogenicity of the two most virulent isolates and the toxicity assay on larvae showed a highest mortality percentage nearly to 100% by 6 days after spraying the larvae with 3.4 × 108 spores/ml of B. bassiana. The mortality percentage reaches to 90% after spraying the larvae with 3.6 × 108 spores/ml of M. anisopliae. The mortality for the adults treated with pesticide arrives to 50% and the control group 10% at the same time. The results revealed that the infection of the adult males by Entomopathogenic fungi (EPF) can be disseminated into the healthy population, after RPW treatment with B. bassiana and M. anisopliae. Our research concludes that B. bassiana and M. anisopliae locally isolated can be used as biological very effective.展开更多
Electronic throttle control (ETC) system has worked its way to becoming a standard subsystem in most of the current automobiles as it has contributed much to the improvement of fuel economy, emissions, drivability and...Electronic throttle control (ETC) system has worked its way to becoming a standard subsystem in most of the current automobiles as it has contributed much to the improvement of fuel economy, emissions, drivability and safety. Precision control of the subsystem, which consists of a dc motor driving a throttle plate, a pre-loaded return spring and a set of gear train to regulate airflow into the engine, seems rather straightforward and yet complex. The difficulties lie in the unknown system parameters, hard nonlinearity of the pre-loaded spring that pulls the throttle plate to its default position, and friction, among others. In this paper, we extend our previous results obtained for the modeling, unknown system parameters identification and control of a commercially available Bosch’s DV-E5 ETC system. Details of modeling and parameters identification based on laboratory experiments, data analysis, and knowledge of the system are provided. The parameters identification results were verified and validated by a real-time PID control implemented with an xPC Target. A nonlinear control design was then proposed utilizing the input-output feedback linearization approach and technique. In view of a recent massive auto recalls due to the controversial uncontrollable engine accelerations, the results of this paper may inspire further research interest on the drive-by-wire technology.展开更多
[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guid...[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guidelines for environmental safety evaluation on chemical pesticides", the toxicity of myricetin and crude extract of M. rubra leaves on non-target organisms was determined and the safety evaluation was carried out. [Result] MyriceUn and crude extract of M. rubra leaves had low toxicity on non-target organisms, such as earthworm, silkworm and soil microbes. Myricetin showed low toxicity and the crude extract of M. rubra leaves showed middle toxicity on tadpole. The high-concentration crude extract of M. rubra leaves had some antifeedant effect on silkworm. [ Conclusion] Myricetin and crude extract of M. rubra leaves had low toxicity on non-tar- get organisms in environment and they were relatively safe.展开更多
基金funded by the General Project of Key Research and Develop-ment Plan of Shaanxi Province(No.2022NY-087).
文摘To address the challenges of high complexity,poor real-time performance,and low detection rates for small target vehicles in existing vehicle object detection algorithms,this paper proposes a real-time lightweight architecture based on You Only Look Once(YOLO)v5m.Firstly,a lightweight upsampling operator called Content-Aware Reassembly of Features(CARAFE)is introduced in the feature fusion layer of the network to maximize the extraction of deep-level features for small target vehicles,reducing the missed detection rate and false detection rate.Secondly,a new prediction layer for tiny targets is added,and the feature fusion network is redesigned to enhance the detection capability for small targets.Finally,this paper applies L1 regularization to train the improved network,followed by pruning and fine-tuning operations to remove redundant channels,reducing computational and parameter complexity and enhancing the detection efficiency of the network.Training is conducted on the VisDrone2019-DET dataset.The experimental results show that the proposed algorithmreduces parameters and computation by 63.8% and 65.8%,respectively.The average detection accuracy improves by 5.15%,and the detection speed reaches 47 images per second,satisfying real-time requirements.Compared with existing approaches,including YOLOv5m and classical vehicle detection algorithms,our method achieves higher accuracy and faster speed for real-time detection of small target vehicles in edge computing.
基金supported by AMED Grants(Nos.JP16cm0106112 and JP16cm0106002)JSPS KAKENHI Grants(Nos.JP17H06412,18H05503,JP19K05744,JP20K05857,JP20H05620,JP21H04720,JP22H04922,and JP22K05363).
文摘Dihydroorotate dehydrogenase(DHODH)is a central enzyme of the de novo pyrimidine biosynthesis pathway and is a promising drug target for the treatment of cancer and autoimmune diseases.This study presents the identification of a potent DHODH inhibitor by proteomic profiling.Cell-based screening revealed that NPD723,which is reduced to H-006 in cells,strongly induces myeloid differentiation and inhibits cell growth in HL-60 cells.H-006 also suppressed the growth of various cancer cells.Proteomic profiling of NPD723-treated cells in ChemProteoBase showed that NPD723 was clustered with DHODH inhibitors.H-006 potently inhibited human DHODH activity in vitro,whereas NPD723 was approximately 400 times less active than H-006.H-006-induced cell death was rescued by the addition of the DHODH product orotic acid.Moreover,metabolome analysis revealed that H-006 treatment promotes marked accumulation of the DHODH substrate dihydroorotic acid.These results suggest that NPD723 is reduced in cells to its active metabolite H-006,which then targets DHODH and suppresses cancer cell growth.Thus,H-006-related drugs represent a potentially powerful treatment for cancer and other diseases.
基金supported by the National Natural Science Foundation of China (Grant No. 81503039)
文摘Apoptosis has been considered as the only form of regulated cell death for a long time. However, a novel form of programmed cell death called necroptosis was recently reported. The process of necroptosis is regulated and plays a critical role in the occurrence and development of multiple human diseases. Thus,the study on the molecular mechanism of necroptosis and its effective inhibitors has been an attractive field for researchers. Herein, we introduce the molecular mechanism of necroptosis and focus on the literature about necroptosis drug screening in recent years. In addition, the identification of the critical drug targets of the necroptosis is also discussed.
文摘MicroRNAs (miRNAs) are a class of ~22 nucleotides long non coding RNA molecules which play an important role in gene regulation at the post transcriptional level. The conserved nature of miRNAs provides the basis of new miRNA identification through homology search. In an attempt to identify new conserved miRNAs in tea, previously known plant miRNAs were used for searching their homolog in a tea Expressed Sequence Tags and full length nucleotide sequence database. The sequences showing homolog no more than four mismatches were predicted for their fold back structures and passed through a series of filtration criteria, finally led us to identify 13 conserved miRNAs in tea belonging to 9 miRNA families. A total of 37 potential target genes in Arabidopsis were identified subsequently for 7 miRNA families based on their sequence complementarity which encode transcription factors (8%), enzymes (30%) and transporters (14%) as well as other proteins involved in physiological and metabolic processes (48%). Overall, our findings will accelerate the way for further researches of miRNAs and their functions in tea.
文摘Ship type identification is an important part of electronic reconnaissance. However, in the existing methods, such as statistical-based methods and fuzzy-mathematics-based methods, the information acquired by the passive sensor is not fully utilized, and there is a certain ambiguity in the assignment relationship of the emitters-ship. They can’t conclude the accurate and reliable assignment relationship of the emitters-ship. Therefore, this paper proposes a comprehensive correlation discriminant method to obtain a more reliable and comprehensive emitters-ship assignment, and then uses information entropy method to identify the type of the target ship on the basis of this association and assign the credibility. The simulation results show that this algorithm can effectively solve the problem of target ship type identification using the information of multi-passive sensors.
文摘On the basis of target transfer function with the early time and late time response together, a method for solving the feature coefficients of target is investigated by utilizing approximation theory and method. Then, the feature coefficients are classified by the minimum distance criterion to identify targets automatically.
文摘In this paper,a new radar target identification scheme is presented based on adaptivediscrimination waveform synthesis and a nearest neighbor neural network.It can directly use theimpulse response of the target to synthesize discrimination waveform,so the poles extractionprocedure is not required.Particularly,it can successfully operate on the case that the poles ofthe target are weakly dependent on the aspect angle.
文摘In this paper, by using the biorthogonal quadrature filters, the biorthogonal mul-tiresolution analysis of finite dimension space equipped with inner product and the fast discrete wavelet transform (FDWT) are constructed. The dual transform method is proposed and the radar data storage is reduced by it. The method of choosing the wavelet coefficients, and the methods of correlation and nearest neighbor classification in wavelet domain based on the compressed data, are presented. The experimental results of the classification, using the high resolution range returns from six kinds of aircrafts, show that the methods of transform, compression and recognition are efficient.
文摘In order to improve the identification capability of ultra wide-band radar,this paper in-troduces a step-variant multiresolution approach for the time-shift parameter estimation. Subsequently,combining with the approach,a Geometrical Theory of Diffraction(GTD) model-based time-shift Invariant method to target identification using Matching Pursuits and Likelihood Ratio Test(IMPLRT) is developed. Simulation results using measured scattering signatures of two targets in an ultra wide-band chamber are presented contrasting the performance of the IMPLRT to the Wang's MPLRT technique.
基金supported by National Natural Science Foundation of China(81773932)
文摘OBJECTIVE Our group mainly focuses on the target identification and pharmacological mechanism study of TCM.We deeply identified the direct targets of the active ingredients in TCM using molecule probe-'Target Fishing' technology in chemical biology,and explored the related signaling pathways to explain the traditional efficiency of TCM.METHODS We synthesized biotin-tagged mole.cule probe by connecting biotin tag to TCM active molecule using PGE as a linker.Then,the biotintagged molecule probe was bound to the surface of solid beads by strong biotin-avidin interaction.Thus,the molecule probe-bound beads were mixed with cell lysates to capture the potential targets and identified by MS.RESULTS Our study found that SA which was an anti-inflammatory compound.could selectively bind to IMPDH2 in microglial cells,and SA showed weaker anti-inflammatory effect on IMPDH2-knock down microglial cells,suggesting IMPDH2 as a key anti-inflammatory target for SA.Ad.ditionally,handelin was a key anti-inflammatory compound.We identified the target protein of handelin as Hsp70 from microglial cells using target pull-down technology.Moreover,handelin showed weaker anti-inflammatory effect on Hsp70-knock down microglial cells,revealing that Hsp70 was the direct antiinflammatory target of handelin.CONCLUSION Our study provided methodology references for TCM target identification in the future,and also showed a new insight for exploring the pharmacological mechanism of TCM active ingredients.More importantly,we can perform scientific annotation for TCM efficiency by clarifying the biological functions of each target protein,showing important significance on modernization and internationalization of TCM.
基金partially supported by the National Key R&D Program of China (Grant No. 2016YFA0600203)the National Natural Science Foundation of China (Grant No. 41575100)
文摘This paper proposes a hybrid method, called CNOP–4 DVar, for the identification of sensitive areas in targeted observations, which takes the advantages of both the conditional nonlinear optimal perturbation(CNOP) and four-dimensional variational assimilation(4 DVar) methods. The proposed CNOP–4 DVar method is capable of capturing the most sensitive initial perturbation(IP), which causes the greatest perturbation growth at the time of verification;it can also identify sensitive areas by evaluating their assimilation effects for eliminating the most sensitive IP. To alleviate the dependence of the CNOP–4 DVar method on the adjoint model, which is inherited from the adjoint-based approach, we utilized two adjointfree methods, NLS-CNOP and NLS-4 DVar, to solve the CNOP and 4 DVar sub-problems, respectively. A comprehensive performance evaluation for the proposed CNOP–4 DVar method and its comparison with the CNOP and CNOP–ensemble transform Kalman filter(ETKF) methods based on 10 000 observing system simulation experiments on the shallow-water equation model are also provided. The experimental results show that the proposed CNOP–4 DVar method performs better than the CNOP–ETKF method and substantially better than the CNOP method.
基金supported by the grants from University of Macao,China,Nos.MYRG2022-00221-ICMS(to YZ)and MYRG-CRG2022-00011-ICMS(to RW)the Natural Science Foundation of Guangdong Province,No.2023A1515010034(to YZ)。
文摘Ischemic stroke is a secondary cause of mortality worldwide,imposing considerable medical and economic burdens on society.Extracellular vesicles,serving as natural nanocarriers for drug delivery,exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke.However,the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency.By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles,their delivery efficacy may be greatly improved.Furthermore,previous studies have indicated that microvesicles,a subset of large-sized extracellular vesicles,can transport mitochondria to neighboring cells,thereby aiding in the restoration of mitochondrial function post-ischemic stroke.Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components,such as proteins or deoxyribonucleic acid,or their sub-components,for extracellular vesicle-based ischemic stroke therapy.In this review,we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies.Given the complex facets of treating ischemic stroke,we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process.Moreover,given the burgeoning interest in mitochondrial delivery,we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.
基金supported by the National Natural Science Foundation of China (No.6200326).
文摘Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.
文摘Plant diseases generate challenging problems in commercial, agriculture and pose real economic threats to both conventional and organic farming systems. The red palm weevil (Rhynchophorus ferrugineus) (RPW) is one of the most destructive pests of palms in the world. Nowadays, control methods revolve around treatments based on chemicals, biotechnological systems using semi-chemicals or the development of the sterile insect technique (hardly sustainable at this time) and biological control. Biological control as the use of natural microorganisms, extracted products from microorganisms or genetically improved to resist or eliminate of pathogens. Our aim was to evaluate the entomopathogenicity of indigenous Beauveria bassiana and Metarhizium anisopliae obtained in Gaza strip against larvae and adults of R. ferrugineus in order to identify indigenous strains potentially suitable for Red Palm Weevil biological control. B. bassiana & M. anisopliae were isolated from larvae and adult dead of RPW from different position of Gaza strip. Morphological analysis of the isolated fungi and molecular identification was determined using PCR technique. Also, the efficiency of the isolated fungi were evaluated under lab conditions and optimized as a biological agent. On the anther hand, the ability of treated RPW male to infect females is examined and calculated using Abbott's formula. Our results showed that the B. bassiana and M. anisopliae exhibited a good biological control agent against larvae and adults of RPW. The pathogenicity of the two most virulent isolates and the toxicity assay on larvae showed a highest mortality percentage nearly to 100% by 6 days after spraying the larvae with 3.4 × 108 spores/ml of B. bassiana. The mortality percentage reaches to 90% after spraying the larvae with 3.6 × 108 spores/ml of M. anisopliae. The mortality for the adults treated with pesticide arrives to 50% and the control group 10% at the same time. The results revealed that the infection of the adult males by Entomopathogenic fungi (EPF) can be disseminated into the healthy population, after RPW treatment with B. bassiana and M. anisopliae. Our research concludes that B. bassiana and M. anisopliae locally isolated can be used as biological very effective.
文摘Electronic throttle control (ETC) system has worked its way to becoming a standard subsystem in most of the current automobiles as it has contributed much to the improvement of fuel economy, emissions, drivability and safety. Precision control of the subsystem, which consists of a dc motor driving a throttle plate, a pre-loaded return spring and a set of gear train to regulate airflow into the engine, seems rather straightforward and yet complex. The difficulties lie in the unknown system parameters, hard nonlinearity of the pre-loaded spring that pulls the throttle plate to its default position, and friction, among others. In this paper, we extend our previous results obtained for the modeling, unknown system parameters identification and control of a commercially available Bosch’s DV-E5 ETC system. Details of modeling and parameters identification based on laboratory experiments, data analysis, and knowledge of the system are provided. The parameters identification results were verified and validated by a real-time PID control implemented with an xPC Target. A nonlinear control design was then proposed utilizing the input-output feedback linearization approach and technique. In view of a recent massive auto recalls due to the controversial uncontrollable engine accelerations, the results of this paper may inspire further research interest on the drive-by-wire technology.
基金Supported by Major Program in Zhejiang Science and Technology Department(2008C22G2100038)Emerging Artists Project in Zhejiang Province(21000037)~~
文摘[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guidelines for environmental safety evaluation on chemical pesticides", the toxicity of myricetin and crude extract of M. rubra leaves on non-target organisms was determined and the safety evaluation was carried out. [Result] MyriceUn and crude extract of M. rubra leaves had low toxicity on non-target organisms, such as earthworm, silkworm and soil microbes. Myricetin showed low toxicity and the crude extract of M. rubra leaves showed middle toxicity on tadpole. The high-concentration crude extract of M. rubra leaves had some antifeedant effect on silkworm. [ Conclusion] Myricetin and crude extract of M. rubra leaves had low toxicity on non-tar- get organisms in environment and they were relatively safe.