For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory n...For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory networks(GRNs)that achieve superior performance in forming trapping pattern towards targets require accurate global positional information to guide swarm robots.This article presents a gene regulatory network with Self-organized grouping and entrapping method for swarms(SUNDER-GRN)to achieve adequate trapping performance with a large-scale swarm in a confined multitarget environment with access to only local information.A hierarchical self-organized grouping method(HSG)is proposed to structure subswarms in a distributed way.In addition,a modified distributed controller,with a relative coordinate system that is established to relieve the need for global information,is leveraged to facilitate subswarms entrapment toward different targets,thus improving the global multi-target entrapping performance.The results demonstrate the superiority of SUNDERGRN in the performance of structuring subswarms and entrapping 10 targets with 200 robots in an environment confined by obstacles and with only local information accessible.展开更多
Alzheimer’s disease(AD)is one of the most common forms of neurodegenerative dementia.The etiology of AD is multifactorial,and its complex pathophysiology involves tau and amyloid-βdeposition,increased oxidative stre...Alzheimer’s disease(AD)is one of the most common forms of neurodegenerative dementia.The etiology of AD is multifactorial,and its complex pathophysiology involves tau and amyloid-βdeposition,increased oxidative stress,neuroinflammation,metabolic disorders,and massive neuronal loss.Due to its complex pathology,no effective cure for AD has been found to date.Therefore,there is an unmet clinical need for the development of new drugs against AD.Natural products are known to be good sources of compounds with pharmacological activity and have potential for the development of new therapeutic agents.Naringin,a naturally occurring flavanone glycoside,is predominantly found in citrus fruits and Chinese medicinal herbs.Mounting evidence shows that naringin and its aglycone,naringenin,have direct neuroprotective effects on AD,such as anti-amyloidogenic,antioxidant,anti-acetylcholinesterase,and anti-neuroinflammatory effects,as well as metal chelation.Furthermore,they are known to improve disordered glucose/lipid metabolism,which is a high risk factor for AD.In this review,we summarize the latest data on the impact of naringin and naringenin on the molecular mechanisms involved in AD pathophysiology.Additionally,we provide an overview of the current clinical applications of naringin and naringenin.The novel delivery systems for naringin and naringenin,which can address their widespread pharmacokinetic limitations,are also discussed.The literature indicates that naringin and naringenin could be multilevel,multitargeted,and multifaceted for preventing and treating AD.展开更多
BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study repo...BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.展开更多
An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as dron...An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.展开更多
Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).T...Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).The United States Preventive Services Task Force(USPSTF) October 2015 draft recommendation for CRC screening included mt-s DNA as an "alternative" screening test that "may be useful in select clinical circumstances",despite its very high sensitivity for early stage CRC.The evidence supporting mt-s DNA for routine screening use is robust.The clinical efficacy of mt-s DNA as measured by sensitivity,specificity,life-years gained(LYG),and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document,especially those requiring annual testing adherence.In a population with primarily irregular screening participation,tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence.This paper reviews the evidence supporting mt-s DNA for routine screening and demonstrates,using USPSTF's modeling data,that mt-s DNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing,high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening.展开更多
It is a tough problem to jointly detect and track a weak target, and it becomes even more challenging when the target is maneuvering. The above problem is formulated by using the Bayesian theory and a multiple model(M...It is a tough problem to jointly detect and track a weak target, and it becomes even more challenging when the target is maneuvering. The above problem is formulated by using the Bayesian theory and a multiple model(MM) based filter is proposed. The filter presented uses the MM method to accommodate the multiple motions that a maneuvering target may travel under by adding a random variable representing the motion model to the target state. To strengthen the efficiency performance of the filter,the target existence variable is separated from the target state and the existence probability is calculated in a more efficient way. To examine the performance of the MM based approach, a typical track-before-detect(TBD) scenario with a maneuvering target is used for simulations. The simulation results indicate that the MM based filter proposed has a good performance in joint detecting and tracking of a weak and maneuvering target, and it is more efficient than the general MM method.展开更多
AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office...AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office-based study examined mt-s DNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-s DNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-s DNA compliance and diagnostic colonoscopy compliance on positive cases.RESULTS Over 12 mo, 77 providers ordered 393 mt-sD NA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sD NA was negative in 85.3%(296/347) and positive in 14.7%(51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer(4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas(15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage Ⅰ(2) and Stage Ⅱ (2), three were located in the proximal colon and one was located in the distal colon.CONCLUSION Mt-s DNA provided medical benefit to screening noncompliant Medicare population. High compliance with mt-s DNA and subsequent follow-up diagnostic colonoscopy identified patients with clinically critical advanced colorectal neoplasia.展开更多
A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation ...A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation functions. According to values of βi^t(K), N events with larger joint probabilities can be searched out as the events with guiding joint probabilities, tiros, the number of searching nodes will be greatly reduced. As a result, this method effectively reduces the calculation load and nnkes it possible to be realized on real-thne, Theoretical ,analysis and Monte Carlo simulation results show that this method is efficient.展开更多
Radar detection of small targets in sea clutter is a particularly demanding task because of the nonstationary characteristic of sea clutter.The track-before-detect(TBD)filter is an effective way to increase the signal...Radar detection of small targets in sea clutter is a particularly demanding task because of the nonstationary characteristic of sea clutter.The track-before-detect(TBD)filter is an effective way to increase the signal-to-clutter ratio(SCR),thus improving the detection performance of small targets in sea clutter.To cope with the nonstationary characteristic of sea clutter,an easily-implemented Bayesian TBD filter with adaptive detection threshold is proposed and a new parameter estimation method is devised which is integrated into the detection process.The detection threshold is set according to the parameter estimation result under the framework of information theory.For detection of closely spaced targets,those within the same range cell as the one under test are treated as contribution to sea clutter,and a successive elimination method is adopted to detect them.Simulation results prove the effectiveness of the proposed algorithm in detecting small targets in nonstationary sea clutter,especially closely spaced ones.展开更多
Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neur...Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neurodegenerative diseases has developed a pressing need to design multitarget-directed ligands to address the complementary pathways involved in these diseases. The major enzyme targets for development of therapeutics for Alzheimer's disease are cholinesterase and β-secretase enzymes. In this review, we discuss recent advances in profiling single target inhibitors based on these enzymes to multitarget-directed ligands as potential therapeutics for this devastating disease. In addition, therapeutics based on iron chelation strategy are discussed as well.展开更多
Detection and tracking of multi-target with unknown and varying number is a challenging issue, especially under the condition of low signal-to-noise ratio(SNR). A modified multi-target track-before-detect(TBD) method ...Detection and tracking of multi-target with unknown and varying number is a challenging issue, especially under the condition of low signal-to-noise ratio(SNR). A modified multi-target track-before-detect(TBD) method was proposed to tackle this issue using a nonstandard point observation model. The method was developed from sequential Monte Carlo(SMC)-based probability hypothesis density(PHD) filter, and it was implemented by modifying the original calculation in update weights of the particles and by adopting an adaptive particle sampling strategy. To efficiently execute the SMC-PHD based TBD method, a fast implementation approach was also presented by partitioning the particles into multiple subsets according to their position coordinates in 2D resolution cells of the sensor. Simulation results show the effectiveness of the proposed method for time-varying multi-target tracking using raw observation data.展开更多
基金supported in part by National Key R&D Program of China(Grant Nos.2021ZD0111501,2021ZD0111502)the Key Laboratory of Digital Signal and Image Processing of Guangdong Province+8 种基金the Key Laboratory of Intelligent Manufacturing Technology(Shantou University)Ministry of Education,the Science and Technology Planning Project of Guangdong Province of China(Grant No.180917144960530)the Project of Educational Commission of Guangdong Province of China(Grant No.2017KZDXM032)the State Key Lab of Digital Manufacturing Equipment&Technology(grant number DMETKF2019020)National Natural Science Foundation of China(Grant Nos.62176147,62002369)STU Scientific Research Foundation for Talents(Grant No.NTF21001)Science and Technology Planning Project of Guangdong Province of China(Grant Nos.2019A050520001,2021A0505030072,2022A1515110660)Science and Technology Special Funds Project of Guangdong Province of China(Grant Nos.STKJ2021176,STKJ2021019)Guangdong Special Support Program for Outstanding Talents(Grant No.2021JC06X549)。
文摘For swarm robots moving in a harsh or uncharted outdoor environment without GPS guidance and global communication,algorithms that rely on global-based information are infeasible.Typically,traditional gene regulatory networks(GRNs)that achieve superior performance in forming trapping pattern towards targets require accurate global positional information to guide swarm robots.This article presents a gene regulatory network with Self-organized grouping and entrapping method for swarms(SUNDER-GRN)to achieve adequate trapping performance with a large-scale swarm in a confined multitarget environment with access to only local information.A hierarchical self-organized grouping method(HSG)is proposed to structure subswarms in a distributed way.In addition,a modified distributed controller,with a relative coordinate system that is established to relieve the need for global information,is leveraged to facilitate subswarms entrapment toward different targets,thus improving the global multi-target entrapping performance.The results demonstrate the superiority of SUNDERGRN in the performance of structuring subswarms and entrapping 10 targets with 200 robots in an environment confined by obstacles and with only local information accessible.
基金supported by the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(No.TGD23C050001)by National Natural Science Foundation of China(No.82074186).
文摘Alzheimer’s disease(AD)is one of the most common forms of neurodegenerative dementia.The etiology of AD is multifactorial,and its complex pathophysiology involves tau and amyloid-βdeposition,increased oxidative stress,neuroinflammation,metabolic disorders,and massive neuronal loss.Due to its complex pathology,no effective cure for AD has been found to date.Therefore,there is an unmet clinical need for the development of new drugs against AD.Natural products are known to be good sources of compounds with pharmacological activity and have potential for the development of new therapeutic agents.Naringin,a naturally occurring flavanone glycoside,is predominantly found in citrus fruits and Chinese medicinal herbs.Mounting evidence shows that naringin and its aglycone,naringenin,have direct neuroprotective effects on AD,such as anti-amyloidogenic,antioxidant,anti-acetylcholinesterase,and anti-neuroinflammatory effects,as well as metal chelation.Furthermore,they are known to improve disordered glucose/lipid metabolism,which is a high risk factor for AD.In this review,we summarize the latest data on the impact of naringin and naringenin on the molecular mechanisms involved in AD pathophysiology.Additionally,we provide an overview of the current clinical applications of naringin and naringenin.The novel delivery systems for naringin and naringenin,which can address their widespread pharmacokinetic limitations,are also discussed.The literature indicates that naringin and naringenin could be multilevel,multitargeted,and multifaceted for preventing and treating AD.
基金Supported by Guangxi Guilin Science and Technology Fund,No.20190218-7-6.
文摘BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.
基金supported by the National Natural Science Foundation of China (61773142)。
文摘An algorithm to track multiple sharply maneuvering targets without prior knowledge about new target birth is proposed. These targets are capable of achieving sharp maneuvers within a short period of time, such as drones and agile missiles.The probability hypothesis density (PHD) filter, which propagates only the first-order statistical moment of the full target posterior, has been shown to be a computationally efficient solution to multitarget tracking problems. However, the standard PHD filter operates on the single dynamic model and requires prior information about target birth distribution, which leads to many limitations in terms of practical applications. In this paper,we introduce a nonzero mean, white noise turn rate dynamic model and generalize jump Markov systems to multitarget case to accommodate sharply maneuvering dynamics. Moreover, to adaptively estimate newborn targets’information, a measurement-driven method based on the recursive random sampling consensus (RANSAC) algorithm is proposed. Simulation results demonstrate that the proposed method achieves significant improvement in tracking multiple sharply maneuvering targets with adaptive birth estimation.
文摘Multitarget stool DNA(mt-sDNA) testing was approved for average risk colorectal cancer(CRC) screening by the United States Food and Drug Administration and thereafter reimbursed for use by the Medicare program(2014).The United States Preventive Services Task Force(USPSTF) October 2015 draft recommendation for CRC screening included mt-s DNA as an "alternative" screening test that "may be useful in select clinical circumstances",despite its very high sensitivity for early stage CRC.The evidence supporting mt-s DNA for routine screening use is robust.The clinical efficacy of mt-s DNA as measured by sensitivity,specificity,life-years gained(LYG),and CRC deaths averted is similar to or exceeds that of the other more specifically recommended screening options included in the draft document,especially those requiring annual testing adherence.In a population with primarily irregular screening participation,tests with the highest point sensitivity and reasonable specificity are more likely to favorably impact CRC related morbidity and mortality than those depending on annual adherence.This paper reviews the evidence supporting mt-s DNA for routine screening and demonstrates,using USPSTF's modeling data,that mt-s DNA at three-year intervals provides significant clinical net benefits and fewer complications per LYG than annual fecal immunochemical testing,high sensitivity guaiac based fecal occult blood testing and 10-year colonoscopy screening.
基金supported by the Natural Science Foundation of Anhui Province(1708085QF149)。
文摘It is a tough problem to jointly detect and track a weak target, and it becomes even more challenging when the target is maneuvering. The above problem is formulated by using the Bayesian theory and a multiple model(MM) based filter is proposed. The filter presented uses the MM method to accommodate the multiple motions that a maneuvering target may travel under by adding a random variable representing the motion model to the target state. To strengthen the efficiency performance of the filter,the target existence variable is separated from the target state and the existence probability is calculated in a more efficient way. To examine the performance of the MM based approach, a typical track-before-detect(TBD) scenario with a maneuvering target is used for simulations. The simulation results indicate that the MM based filter proposed has a good performance in joint detecting and tracking of a weak and maneuvering target, and it is more efficient than the general MM method.
文摘AIM To determine the uptake of noninvasive multitarget stool DNA (mt-s DNA) in a cohort of colorectal cancer(CRC) screening non-compliant average-risk Medicare patients.METHODS This cross sectional primary care office-based study examined mt-s DNA uptake in routine clinical practice among 393 colorectal cancer screening non-compliant Medicare patients ages 50-85 ordered by 77 physicians in a multispecialty group practice (USMD Physician Services, Dallas, TX) from October, 2014-September, 2015. Investigators performed a Health Insurance Portability and Accountability Act compliant retrospective review of electronic health records to identify mt-s DNA use in patients who were either > 10 years since last colonoscopy and/or > 1 year since last fecal occult blood test. Test positive patients were advised to get diagnostic colonoscopy and thereafter patients were characterized by the most clinically significant lesion documented on histopathology of biopsies or excisional tissue. Descriptive statistics were employed. Key outcome measures included mt-s DNA compliance and diagnostic colonoscopy compliance on positive cases.RESULTS Over 12 mo, 77 providers ordered 393 mt-sD NA studies with 347 completed (88.3% compliance). Patient mean age was 69.8 (50-85) and patients were 64% female. Mt-sD NA was negative in 85.3%(296/347) and positive in 14.7%(51/347). Follow-up colonoscopy was performed in 49 positive patients (96.1% colonoscopy compliance) with two patients lost to follow up. Index findings included: colon cancer(4/49, 8.2%), advanced adenomas (21/49, 42.9%), non-advanced adenomas(15/49, 30.6%), and negative results (9/49, 18.4%). The positive predictive value for advanced colorectal lesions was 51.0% and for any colorectal neoplasia was 81.6%. The mean age of patients with colorectal cancer was 70.3 and all CRC's were localized Stage Ⅰ(2) and Stage Ⅱ (2), three were located in the proximal colon and one was located in the distal colon.CONCLUSION Mt-s DNA provided medical benefit to screening noncompliant Medicare population. High compliance with mt-s DNA and subsequent follow-up diagnostic colonoscopy identified patients with clinically critical advanced colorectal neoplasia.
文摘A fast joint probabilistic data association (FJPDA) algorithm is proposed in tiffs paper. Cluster probability matrix is approximately calculated by a new method, whose elements βi^t(K) can be taken as evaluation functions. According to values of βi^t(K), N events with larger joint probabilities can be searched out as the events with guiding joint probabilities, tiros, the number of searching nodes will be greatly reduced. As a result, this method effectively reduces the calculation load and nnkes it possible to be realized on real-thne, Theoretical ,analysis and Monte Carlo simulation results show that this method is efficient.
基金supported by the National Natural Science Foundation of China(61671139)。
文摘Radar detection of small targets in sea clutter is a particularly demanding task because of the nonstationary characteristic of sea clutter.The track-before-detect(TBD)filter is an effective way to increase the signal-to-clutter ratio(SCR),thus improving the detection performance of small targets in sea clutter.To cope with the nonstationary characteristic of sea clutter,an easily-implemented Bayesian TBD filter with adaptive detection threshold is proposed and a new parameter estimation method is devised which is integrated into the detection process.The detection threshold is set according to the parameter estimation result under the framework of information theory.For detection of closely spaced targets,those within the same range cell as the one under test are treated as contribution to sea clutter,and a successive elimination method is adopted to detect them.Simulation results prove the effectiveness of the proposed algorithm in detecting small targets in nonstationary sea clutter,especially closely spaced ones.
文摘Neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's diseases have multifaceted nature because of the different factors contributing to their progression. The complex nature of neurodegenerative diseases has developed a pressing need to design multitarget-directed ligands to address the complementary pathways involved in these diseases. The major enzyme targets for development of therapeutics for Alzheimer's disease are cholinesterase and β-secretase enzymes. In this review, we discuss recent advances in profiling single target inhibitors based on these enzymes to multitarget-directed ligands as potential therapeutics for this devastating disease. In addition, therapeutics based on iron chelation strategy are discussed as well.
基金Projects(61002022,61471370)supported by the National Natural Science Foundation of China
文摘Detection and tracking of multi-target with unknown and varying number is a challenging issue, especially under the condition of low signal-to-noise ratio(SNR). A modified multi-target track-before-detect(TBD) method was proposed to tackle this issue using a nonstandard point observation model. The method was developed from sequential Monte Carlo(SMC)-based probability hypothesis density(PHD) filter, and it was implemented by modifying the original calculation in update weights of the particles and by adopting an adaptive particle sampling strategy. To efficiently execute the SMC-PHD based TBD method, a fast implementation approach was also presented by partitioning the particles into multiple subsets according to their position coordinates in 2D resolution cells of the sensor. Simulation results show the effectiveness of the proposed method for time-varying multi-target tracking using raw observation data.