A ransomware attack that interrupted the operation of Colonial Pipeline(a large U.S.oil pipeline company),showed that security threats by malware have become serious enough to affect industries and social infrastructu...A ransomware attack that interrupted the operation of Colonial Pipeline(a large U.S.oil pipeline company),showed that security threats by malware have become serious enough to affect industries and social infrastructure rather than individuals alone.The agents and characteristics of attacks should be identified,and appropriate strategies should be established accordingly in order to respond to such attacks.For this purpose,the first task that must be performed is malware classification.Malware creators are well aware of this and apply various concealment and avoidance techniques,making it difficult to classify malware.This study focuses on new features and classification techniques to overcome these difficulties.We propose a behavioral performance visualization method using utilization patterns of system resources,such as the central processing unit,memory,and input/output,that are commonly used in performance analysis or tuning of programs.We extracted the usage patterns of the system resources for ransomware to performbehavioral performance visualization.The results of the classification performance evaluation using the visualization results indicate an accuracy of at least 98.94%with a 3.69%loss rate.Furthermore,we designed and implemented a framework to perform the entire process—from data extraction to behavioral performance visualization and classification performance measurement—that is expected to contribute to related studies in the future.展开更多
Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to ...Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.展开更多
D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurode...D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurodegeneration, such as synaptic plasticity, spatial learning and memory abilities, in mouse models of aging. D-galactose-induced aging mice were administered daily subcutaneous injections of D-galactose at the base of the neck for 10 consecutive weeks. Then, the mice were subjected to exercise training by running on a treadmill for 6 days a week. Shortened escape latency in a Morris water maze test indicated that exercise improved learning and memory in aging mice. The ameliorative changes were likely induced by an upregulation of Bcl-2 and brain-derived neurotrophic factor, the repression of apoptosis factors such as Fas and Bax, and an increase in the activity of glucose transporters-1 and 4. The data suggest moderate exercise may retard or inhibit neurodegeneration in D-galactose-induced aging mice.展开更多
BACKGROUND: Prophylactic dietary restriction (DR), whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective...BACKGROUND: Prophylactic dietary restriction (DR), whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective efficacy of DR initiate late in life or accompany the aging process remains unclear.OBJECTIVE: The present study sought to: (1) determine if DR could protect against behavioral decline in mice when implemented during the aging process induced by D-galactose and (2) examine neuronal apoptosis in these aged brains and whether DR could block apoptosis.DESIGN, TIME AND SETTING: The randomized controlled animal study. The experiment was performed at the Experimental Animal Center of Capital Medical University and the Laboratory Center of School of Public Health of Captial Medical University of China from April 2006 to October 2007.MATERIALS: D-galactose (D-gal) was purchased from Beijing Chemical-Regent Company (Beijing, China). Terminal transferase dUTP nick end labeling (TUNEL) detection kit was obtained from Roche, Germany. Assay kits for antioxidant enzyme activities and malondialdehyde contents were purchased from Jiancheng Institute of Biotechnology (Nanjing, China). Morris water maze (Friends Honesty Life Sciences Co. Ltd., Hong Kong, China) and Flow Cytometry (Coulter, USA) were used in this study.METHODS: A total of 40 male Institute of Cancer Research (lCR) mice, 3 months old, were equally and randomly divided into D-gal treatment, DR treatment, D-gal + DR treatment and normal control groups, and were then randomly assigned to one of two feeding regimens: ad libitum access to food or DR which received a 70% amount of daily food intake as that by ad libitum fed mice. There were two replicates per feeding regimen and mice were fed for 10 weeks,with or without a daily subcutaneous injection of D-gal at 100 mg/kg.MAIN OUTCOME MEASURES: Animals' spatial learning and memory performance were tested in the Morris water maze. Neuronal apoptosis rates were evaluated by Annexin V/flow cytometry assay and TUNEL assay. Lipid peroxidation levels and antioxidant defense capacity of the brain were measured using testing kits.RESULTS: DR markedly reduced the prolonged escape latency of D-gal mice in the water maze test (P〈0.01). Annexin V and TUNEL assays showed that the D-gal mice had a significant higher percentage of neuronal apoptosis compared with normal control mice (P〈0.05), and that DR treatment markedly decreased this apoptotic cell death (P〈0.05). DR also reversed the decline of total superoxide dismutase and glutathione peroxidase activities and the increase of malondialdehyde levels in the brain of D-gal mice (P〈0.05, respectively).CONCLUSION: DR reduces the impact of D-gal-induced brain aging in mice and can reverse performance decline and neurobiochemical impairments. These results demonstrate that implementation of DR in conditions of chronic oxidative stress can be neuroprotective, and that senium DR can be beneficial for healthy aging.展开更多
Mg–Zn–Ag alloys have been extensively studied in recent years for potential biodegradable implants due to their unique mechanical properties,biodegradability and biocompatibility.In the present study,Mg–3Zn-x Ag(w...Mg–Zn–Ag alloys have been extensively studied in recent years for potential biodegradable implants due to their unique mechanical properties,biodegradability and biocompatibility.In the present study,Mg–3Zn-x Ag(wt%,x=0.2,0.5 and0.8)alloys with single-phase crystal structure were prepared by backward extrusion at 340°C.The addition of Ag element into Mg–3Zn slightly influences the ultimate tensile strength and microstructure,but the elongation firstly increases from12%to 19.8%and then decreases from 19.8%to 9.9%with the increment of Ag concentration.The tensile yield strength,ultimate tensile strength and elongation of Mg–3Zn–0.2Ag alloy reach up to 142,234 MPa and 19.8%,respectively,which are the best mechanical performance of Mg–Zn–Ag alloys in the present work.The extruded Mg–3Zn–0.2Ag alloy also possesses the best corrosion behavior with the corresponding corrosion rate of 3.2 mm/year in immersion test,which could be explained by the single-phase and uniformly distributed grain structure,and the fewer twinning.展开更多
China has been developed into one of the most active regions in terms of both fundamental and applied research on magnesium (Mg) and its alloys in the world from a solid base laid by its prominent metallurgist and m...China has been developed into one of the most active regions in terms of both fundamental and applied research on magnesium (Mg) and its alloys in the world from a solid base laid by its prominent metallurgist and materials scientists over the past decades. Nowadays, a large number of young-generation researchers have been inspired by their predecessors and become the key participants in the fields of Mg alloys, which consequently led to the establishment of China Youth Scholar Society for Magnesium Alloys Research in 2015. Since then, the first two China Youth Scholars Symposiums on Mg Alloys Research had been held at Harbin (2015) and Chongqing (2016) China, respectively. A number of crucial research inter- ests related to fundamental and applied Mg research were discussed at the conferences and summarized in this short perspective, aiming to boost far-reaching initiatives for development of new Mg-based materials to satisfy the requirements for a broad range of industrial employments. Herein, four main aspects are included as follows: i) Plastic deformation mechanism and strengthening strategy, ii) Design and development of new Mg-based materials, iii) Key service properties, and iv) New processing technologies.展开更多
C/C–SiC–HfC composites were fabricated via precursor infiltration and pyrolysis using a mixture solution of organic hafnium-containing polymer and polycarbosilane as precursor. The microstructures and the phases of ...C/C–SiC–HfC composites were fabricated via precursor infiltration and pyrolysis using a mixture solution of organic hafnium-containing polymer and polycarbosilane as precursor. The microstructures and the phases of the composites were analyzed by scanning electron microscopy and X-ray diffraction. The ablation resistance of the composites was evaluated under 3,000 °C oxyacetylene torch. After ablation for 120 s, the composites exhibit good ablation properties with the linear and mass ablation rates of 9.1 9 10-4mm/s and 1.30 9 10-3g/s, which are far lower than those of the C/C–SiC composites. The excellent ablative property of the C/C–SiC–HfC composites is resulted from the formation of HfO2 molten layer on the surface of the composites, which could play a positive role in reducing heat transfer and preventing oxygen transport to the underlying carbon substrate.展开更多
基金This work was supported by the Institute of Information&Communications Technology Planning&Evaluation(IITP)(Project No.2019-0-00426%,10%)the ICT R&D Program of MSIT/IITP(Project No.2021-0-01816,A Research on Core Technology of Autonomous Twins for Metaverse,10%)National Research Foundation of Korea(NRF)grant funded by the Korean government(Project No.NRF-2020R1A2C4002737%,80%).
文摘A ransomware attack that interrupted the operation of Colonial Pipeline(a large U.S.oil pipeline company),showed that security threats by malware have become serious enough to affect industries and social infrastructure rather than individuals alone.The agents and characteristics of attacks should be identified,and appropriate strategies should be established accordingly in order to respond to such attacks.For this purpose,the first task that must be performed is malware classification.Malware creators are well aware of this and apply various concealment and avoidance techniques,making it difficult to classify malware.This study focuses on new features and classification techniques to overcome these difficulties.We propose a behavioral performance visualization method using utilization patterns of system resources,such as the central processing unit,memory,and input/output,that are commonly used in performance analysis or tuning of programs.We extracted the usage patterns of the system resources for ransomware to performbehavioral performance visualization.The results of the classification performance evaluation using the visualization results indicate an accuracy of at least 98.94%with a 3.69%loss rate.Furthermore,we designed and implemented a framework to perform the entire process—from data extraction to behavioral performance visualization and classification performance measurement—that is expected to contribute to related studies in the future.
基金supported by grants from the Ministerio de Economia y Competitividad(BFU2013-43458-R)Junta de Andalucia(P12-CTS-1694 and Proyexcel-00422)to ZUK。
文摘Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.
基金supported by the National Natural Science Foundation of China,No.81373020Beijing Natural Science Foundation of China,No.7112014+1 种基金a grant from the Science and Technology Development Project of Beijing Municipal Education Commission of China,No.KM201110025014a grant from the Beijing Municipal Science and Technology Project of China,No.Z131107002213071
文摘D-galactose has been widely used in aging research because of its efficacy in inducing senescence and accelerating aging in animal models. The present study investigated the benefits of exercise for preventing neurodegeneration, such as synaptic plasticity, spatial learning and memory abilities, in mouse models of aging. D-galactose-induced aging mice were administered daily subcutaneous injections of D-galactose at the base of the neck for 10 consecutive weeks. Then, the mice were subjected to exercise training by running on a treadmill for 6 days a week. Shortened escape latency in a Morris water maze test indicated that exercise improved learning and memory in aging mice. The ameliorative changes were likely induced by an upregulation of Bcl-2 and brain-derived neurotrophic factor, the repression of apoptosis factors such as Fas and Bax, and an increase in the activity of glucose transporters-1 and 4. The data suggest moderate exercise may retard or inhibit neurodegeneration in D-galactose-induced aging mice.
文摘BACKGROUND: Prophylactic dietary restriction (DR), whether lifelong or started in adulthood,retards the aging process and attenuates cognitive decline in rodents. However, whether the anti-aging and neuroprotective efficacy of DR initiate late in life or accompany the aging process remains unclear.OBJECTIVE: The present study sought to: (1) determine if DR could protect against behavioral decline in mice when implemented during the aging process induced by D-galactose and (2) examine neuronal apoptosis in these aged brains and whether DR could block apoptosis.DESIGN, TIME AND SETTING: The randomized controlled animal study. The experiment was performed at the Experimental Animal Center of Capital Medical University and the Laboratory Center of School of Public Health of Captial Medical University of China from April 2006 to October 2007.MATERIALS: D-galactose (D-gal) was purchased from Beijing Chemical-Regent Company (Beijing, China). Terminal transferase dUTP nick end labeling (TUNEL) detection kit was obtained from Roche, Germany. Assay kits for antioxidant enzyme activities and malondialdehyde contents were purchased from Jiancheng Institute of Biotechnology (Nanjing, China). Morris water maze (Friends Honesty Life Sciences Co. Ltd., Hong Kong, China) and Flow Cytometry (Coulter, USA) were used in this study.METHODS: A total of 40 male Institute of Cancer Research (lCR) mice, 3 months old, were equally and randomly divided into D-gal treatment, DR treatment, D-gal + DR treatment and normal control groups, and were then randomly assigned to one of two feeding regimens: ad libitum access to food or DR which received a 70% amount of daily food intake as that by ad libitum fed mice. There were two replicates per feeding regimen and mice were fed for 10 weeks,with or without a daily subcutaneous injection of D-gal at 100 mg/kg.MAIN OUTCOME MEASURES: Animals' spatial learning and memory performance were tested in the Morris water maze. Neuronal apoptosis rates were evaluated by Annexin V/flow cytometry assay and TUNEL assay. Lipid peroxidation levels and antioxidant defense capacity of the brain were measured using testing kits.RESULTS: DR markedly reduced the prolonged escape latency of D-gal mice in the water maze test (P〈0.01). Annexin V and TUNEL assays showed that the D-gal mice had a significant higher percentage of neuronal apoptosis compared with normal control mice (P〈0.05), and that DR treatment markedly decreased this apoptotic cell death (P〈0.05). DR also reversed the decline of total superoxide dismutase and glutathione peroxidase activities and the increase of malondialdehyde levels in the brain of D-gal mice (P〈0.05, respectively).CONCLUSION: DR reduces the impact of D-gal-induced brain aging in mice and can reverse performance decline and neurobiochemical impairments. These results demonstrate that implementation of DR in conditions of chronic oxidative stress can be neuroprotective, and that senium DR can be beneficial for healthy aging.
基金supported by the National Natural Science Foundation of China (Nos. 51371046 and 51525101)the National Key Research and Development Program of China (No. 2016YFB0701202)the Fundamental Research Funds of the Central Universities (No. N141008001)
文摘Mg–Zn–Ag alloys have been extensively studied in recent years for potential biodegradable implants due to their unique mechanical properties,biodegradability and biocompatibility.In the present study,Mg–3Zn-x Ag(wt%,x=0.2,0.5 and0.8)alloys with single-phase crystal structure were prepared by backward extrusion at 340°C.The addition of Ag element into Mg–3Zn slightly influences the ultimate tensile strength and microstructure,but the elongation firstly increases from12%to 19.8%and then decreases from 19.8%to 9.9%with the increment of Ag concentration.The tensile yield strength,ultimate tensile strength and elongation of Mg–3Zn–0.2Ag alloy reach up to 142,234 MPa and 19.8%,respectively,which are the best mechanical performance of Mg–Zn–Ag alloys in the present work.The extruded Mg–3Zn–0.2Ag alloy also possesses the best corrosion behavior with the corresponding corrosion rate of 3.2 mm/year in immersion test,which could be explained by the single-phase and uniformly distributed grain structure,and the fewer twinning.
基金support from Chinese Committee for Magnesium and its Application
文摘China has been developed into one of the most active regions in terms of both fundamental and applied research on magnesium (Mg) and its alloys in the world from a solid base laid by its prominent metallurgist and materials scientists over the past decades. Nowadays, a large number of young-generation researchers have been inspired by their predecessors and become the key participants in the fields of Mg alloys, which consequently led to the establishment of China Youth Scholar Society for Magnesium Alloys Research in 2015. Since then, the first two China Youth Scholars Symposiums on Mg Alloys Research had been held at Harbin (2015) and Chongqing (2016) China, respectively. A number of crucial research inter- ests related to fundamental and applied Mg research were discussed at the conferences and summarized in this short perspective, aiming to boost far-reaching initiatives for development of new Mg-based materials to satisfy the requirements for a broad range of industrial employments. Herein, four main aspects are included as follows: i) Plastic deformation mechanism and strengthening strategy, ii) Design and development of new Mg-based materials, iii) Key service properties, and iv) New processing technologies.
基金financially supported by the National Natural Science Foundation of China(Nos.51221001 and 51272213)the Author of National Excellent Doctoral Dissertation of China(No.201036),the ‘‘111’’ project of China (No.B08040)National Basic Research program of China (No.2011CB605806)
文摘C/C–SiC–HfC composites were fabricated via precursor infiltration and pyrolysis using a mixture solution of organic hafnium-containing polymer and polycarbosilane as precursor. The microstructures and the phases of the composites were analyzed by scanning electron microscopy and X-ray diffraction. The ablation resistance of the composites was evaluated under 3,000 °C oxyacetylene torch. After ablation for 120 s, the composites exhibit good ablation properties with the linear and mass ablation rates of 9.1 9 10-4mm/s and 1.30 9 10-3g/s, which are far lower than those of the C/C–SiC composites. The excellent ablative property of the C/C–SiC–HfC composites is resulted from the formation of HfO2 molten layer on the surface of the composites, which could play a positive role in reducing heat transfer and preventing oxygen transport to the underlying carbon substrate.