We sought to assess the incidence of aspirin resistance after off-pump coronary artery bypass (OPCAB) surgery, and investigate whether clopidogrel can improve aspirin response and be safely applied early after OPCAB...We sought to assess the incidence of aspirin resistance after off-pump coronary artery bypass (OPCAB) surgery, and investigate whether clopidogrel can improve aspirin response and be safely applied early after OPCAB surgery. Sixty patients who underwent standard OPCAB surgery were randomized into two groups. One group (30 patients) received mono-antiplatelet treatment (MAPT) with aspirin 100 mg daily and the other group received dual anfiplatelet treatment (DAPT) with aspirin 100 mg daily plus clopidogrel 75 mg daily. Platelet aggregations in response to arachi- donic acid (PLAA) and adenosine diphosphate (ADP) (PLADP) were measured preoperatively and on days 1 to 6, 8 and 10 after the antiplatelet agents were administered. A PLAA level above 20% was defined as aspirin resistance. Postoperative bleeding and other perioperative variables were also recorded. There were no significant differences between the two groups in baseline characteristics, average number of distal anastomosis, operation time, postoperative bleeding, ventilation time and postoperative hospital stay. However, the incidence of aspirin resistance was significantly lower in the DAPT group than that in the MAPT group on the first and second day after antiplatelet agents were given (62.1% vs, 32.1%, 34.5% vs. 10.7%, respectively, both P 〈 0.05). There was no significant difference in postoperative complication between the two groups. DAPT with aspirin and clopidogrel can be safely applied to OPCAB patients early after the procedure. Moreover, clopidogrel reduces the incidence of OPCAB-related aspirin resistance.展开更多
Internet traffic encryption is a very common traffic protection method.Most internet traffic is protected by the encryption protocol called transport layersecurity (TLS). Although traffic encryption can ensure the sec...Internet traffic encryption is a very common traffic protection method.Most internet traffic is protected by the encryption protocol called transport layersecurity (TLS). Although traffic encryption can ensure the security of communication, it also enables malware to hide its information and avoid being detected.At present, most of the malicious traffic detection methods are aimed at the unencrypted ones. There are some problems in the detection of encrypted traffic, suchas high false positive rate, difficulty in feature extraction, and insufficient practicability. The accuracy and effectiveness of existing methods need to be improved.In this paper, we present TLSmell, a framework that conducts maliciousencrypted HTTPs traffic detection with simple connection-specific indicators byusing different classifiers based online training. We perform deep packet analysisof encrypted traffic through data pre-processing to extract effective features, andthen the online training algorithm is used for training and prediction. Withoutdecrypting the original traffic, high-precision malicious traffic detection and analysis are realized, which can guarantee user privacy and communication security.At the same time, since there is no need to decrypt the traffic in advance, the effi-ciency of detecting malicious HTTPs traffic will be greatly improved. Combinedwith the traditional detection and analysis methods, malicious HTTPs traffic isscreened, and suspicious traffic is further analyzed by the expert through the context of suspicious behaviors, thereby improving the overall performance of malicious encrypted traffic detection.展开更多
A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modificati...A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modification was found to passivate some external Br?nsted and Lewis acid sites by37.8%,in which Br?nsted acid sites(BAS)were found more easily sacrificed by breaking the surface Al AO bond of bridging hydroxyl groups and forming Si AOASi bonds.The selectivity of ZN-8 catalyst for light olefins(ethylene,propylene and butene)in n-decane catalytic cracking is up to 26%(450℃,WHSV=10.95 h^(-1)),which is ca.78%higher than that of parent one.The better performance was attributed to the appropriate external acid density in ZN-8,which inhibits bimolecular hydrogen transfer reaction of light olefins on the adjacent acid sites,resulting in more olefins,few coke precursors and thus an excellent catalytic stability.展开更多
In the Internet of vehicles(IoV),direct communication between vehicles,i.e.,vehicle-tovehicle(V2V)may have lower latency,compared to the schemes with help of Road Side Unit(RSU)or base station.In this paper,the scenar...In the Internet of vehicles(IoV),direct communication between vehicles,i.e.,vehicle-tovehicle(V2V)may have lower latency,compared to the schemes with help of Road Side Unit(RSU)or base station.In this paper,the scenario where the demands of a vehicle are satisfied by cooperative transmissions from those one in front is considered.Since the topology of the vehicle network is dynamic,random linear network coding is applied in such a multisource single-sink vehicle-to-vehicle network,where each vehicle is assumed to broadcast messages to others so that the intermediate vehicles between sources and sink can reduce the latency collaboratively.It is shown that the coding scheme can significantly reduce the time delay compared with the non-coding scheme even in the channels with high packet loss rate.In order to further optimize the coding scheme,one can increase the generation size,where the generation size means the number of raw data packets sent by the source node to the sink node in each round of communication.Under the premise of satisfying the coding validity,we can dynamically select the Galois field size according to the number of intermediate nodes.It is not surprised that the reduction in the Galois field size can further reduce the transmission latency.展开更多
In order to more easily measure the concentration of solution with the Tyndall phenomenon in the outdoor, a portable instrument using imageprocessing for collecting and processing images of Tyndall phenomenon is propo...In order to more easily measure the concentration of solution with the Tyndall phenomenon in the outdoor, a portable instrument using imageprocessing for collecting and processing images of Tyndall phenomenon is proposed. The software and hardware of light measurement module of the portable instrument are described in this paper, including the selection of the incident light and the image sensor. Then the optical path of the captured picture was extracted and the light intensity value was calculated. Through the standard sample, the linear relationship between the light intensity in the Tyndall phenomenon and the concentration was fitted to determine the concentration of the colloidal liquid to be tested. Theoretical analysis and simulation results show that the method of obtaining the concentration of colloidal liquid by using the relationship between the RGB mean of the image and the light intensity of Tyndall can control the error within 10%, which meets the preliminary test requirements.展开更多
When the red laser illuminates the lyosol, the Tyndall effect will form a light path with a certain distance, and the optical properties of the lyosol will have a certain influence on the Tyndall light intensity. This...When the red laser illuminates the lyosol, the Tyndall effect will form a light path with a certain distance, and the optical properties of the lyosol will have a certain influence on the Tyndall light intensity. This paper mainly aims at the theoretical and experimental studies on the change situation of the lyosol concentration and the attenuation characteristics of the light path when the red laser changes with the distance of the light path in the solution. In order to study the effect of lyosol concentration on the Tyndall light path, digital image technology was applied to the measurement of lyosol concentration. Due to the non-contact property of the image, the liquid concentration can be measured accurately in real time. The attenuation characteristics of the laser in the lyosol were obtained by image processing technology, and the quantitative relationship between the attenuation coefficient of the Tyndall light path and the lyosol concentration was obtained.展开更多
Objective:To explore the role of midwifery care in the prevention of neonatal asphyxia.Method:The 100 cases of parturient received in our hospital from January 2018 to January 2021 were divided into two groups,respect...Objective:To explore the role of midwifery care in the prevention of neonatal asphyxia.Method:The 100 cases of parturient received in our hospital from January 2018 to January 2021 were divided into two groups,respectively,the control group and the experimental group with 50 cases in each group.The control group received routine care,and the experimental group received midwifery care.The psychological status of the mothers and the occurrence of neonatal asphyxia were compared between the two groups.Results:Before nursing,there was no significant difference in the mental state of the two groups of parturient(P>0.05).After the nursing,the mental state of the parturient in the experimental group was significantly better than that of the control group(P<0.05);After different ways of nursing,the incidence of asphyxia in neonates in the control group was significantly higher than that in the experimental group(P<0.05),and the comparison between the groups was statistically significant.Conclusion:The timely delivery of midwifery care for parturient can improve the mental state of the parturient and help reduce the incidence of neonatal asphyxia.It is worthy of clinical attention and promotion.展开更多
OBJECTIVE: To investigate the effects of the Sini San at different doses on each sleeping state[slow-wave sleep 1(SWS1), slow-wave sleep 2(SWS2), rapid-eye-movement(REM), wakefulness(W)] in insomnia rats and to identi...OBJECTIVE: To investigate the effects of the Sini San at different doses on each sleeping state[slow-wave sleep 1(SWS1), slow-wave sleep 2(SWS2), rapid-eye-movement(REM), wakefulness(W)] in insomnia rats and to identify its mode of ac-tion for improving sleep.METHODS: The insomnia rats were randomly divided into a high-, medium- or low-dose group of Sini San(equal to crude drug 8.8, 4.4, or 2.2 g/kg, respectively) for seven consecutive days.RESULTS: Compared with pre-administration,SWS2 was significantly increased after administration of the low dose. Compared with pre-administration, W was significantly decreased and SWS1,SWS2, and the total sleeping time(TST) were markedly increased after administration of the medium dose. Compared with pre-administration, W was significantly decreased and SWS1, SWS2, rapid-eye-movement sleep, and TST were significantly longer after administration of the high dose. The effects of Sini San on sleep-wake cycle are dose-dependent.CONCLUSION: The results suggest that Sini San extends SWS1 and SWS2, which increases the total sleeping time.展开更多
Purpose:To develop an automated classification system using a machine learning classifier to distinguish clinically unaffected eyes in patients with keratoconus from a normal control population based on a combination ...Purpose:To develop an automated classification system using a machine learning classifier to distinguish clinically unaffected eyes in patients with keratoconus from a normal control population based on a combination of Scheimpflug camera images and ultra-high-resolution optical coherence tomography(UHR-OCT)imaging data.Methods:A total of 121 eyes from 121 participants were classified by 2 cornea experts into 3 groups:normal(50 eyes),with keratoconus(38 eyes)or with subclinical keratoconus(33 eyes).All eyes were imaged with a Scheimpflug camera and UHR-OCT.Corneal morphological features were extracted from the imaging data.A neural network was used to train a model based on these features to distinguish the eyes with subclinical keratoconus from normal eyes.Fisher’s score was used to rank the differentiable power of each feature.The receiver operating characteristic(ROC)curves were calculated to obtain the area under the ROC curves(AUCs).Results:The developed classification model used to combine all features from the Scheimpflug camera and UHR-OCT dramatically improved the differentiable power to discriminate between normal eyes and eyes with subclinical keratoconus(AUC=0.93).The variation in the thickness profile within each individual in the corneal epithelium extracted from UHR-OCT imaging ranked the highest in differentiating eyes with subclinical keratoconus from normal eyes.Conclusion:The automated classification system using machine learning based on the combination of Scheimpflug camera data and UHR-OCT imaging data showed excellent performance in discriminating eyes with subclinical keratoconus from normal eyes.The epithelial features extracted from the OCT images were the most valuable in the discrimination process.This classification system has the potential to improve the differentiable power of subclinical keratoconus and the efficiency of keratoconus screening.展开更多
OBJECTIVE: To investigate the sedative and hypnotic activity of paeoniflorin and freeze-dried Sini San powder on mice and provide a reliable method for determining the pharmacodynamic material basis of Sini San.METHOD...OBJECTIVE: To investigate the sedative and hypnotic activity of paeoniflorin and freeze-dried Sini San powder on mice and provide a reliable method for determining the pharmacodynamic material basis of Sini San.METHODS: Male adult mice weighing 20-22 g were used in this study. Three experiments were carried out. Synergism with pentobarbital was used as an index for hypnotic effect. Loss of the righting reflex was used to determine the start of sleep.Sleep latency and sleeping time were recorded in each experiment.RESULTS: The coefficient of variation of the suprathreshold dose(55 mg/kg) was significantly lower than that of the threshold dose. The sleep latency of mice was significantly decreased, and the sleeping time of mice was significantly prolonged. The effects of paeoniflorin and Sini San on prolonging the sleeping time of mice induced by pentobarbital sodium were significantly stronger than those in the control group.CONCLUSION: Paeoniflorin produces significant sedative and hypnotic effects, and there is an obvious dose-effect relationship.展开更多
There is debating over the question of whether the large-scale‘Grain for Green’program on the Loess Plateau of China threatens regional food security.Self-sufficiency index and cropland pressure index were used to a...There is debating over the question of whether the large-scale‘Grain for Green’program on the Loess Plateau of China threatens regional food security.Self-sufficiency index and cropland pressure index were used to assess food security on the Loess Plateau after the implementation of revegetation program.The results showed that the‘Grain for Green’program initially had a considerable impact on regional food security,where grain yield fell from 1999 to 2001,resulting in a lower grain self-sufficiency and increased farmland stress.Subsequently,grain yield in this region increased due to the elevated agricultural material input and increased construction of terraces and check dams.The grain self-sufficiency index would have increased to 96.55%if there were improvements to the agricultural conditions,such as fertilization and irrigation,which would have resulted in an increase in the crop yield per unit of 20%.However,the grain self-sufficiency increased to 105.25%via the construction of terraces and check dams.Thus,the government should further expand the‘Grain for Green’program in coordination with improvements to the agricultural production conditions and the construction of terraces and check dams on the Loess Plateau.展开更多
In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels...In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels,state-of-the-art static analysis based Power Shell attack detection approaches are inherently vulnerable to obfuscations.In this paper,we design the first generic,effective,and lightweight deobfuscation approach for PowerShell scripts.To precisely identify the obfuscated script fragments,we define obfuscation based on the differences in the impacts on the abstract syntax trees of PowerShell scripts and propose a novel emulation-based recovery technology.Furthermore,we design the first semantic-aware PowerShell attack detection system that leverages the classic objective-oriented association mining algorithm and newly identifies 31 semantic signatures.The experimental results on 2342 benign samples and 4141 malicious samples show that our deobfuscation method takes less than 0.5 s on average and increases the similarity between the obfuscated and original scripts from 0.5%to 93.2%.By deploying our deobfuscation method,the attack detection rates for Windows Defender and VirusTotal increase substantially from 0.33%and 2.65%to 78.9%and 94.0%,respectively.Moreover,our detection system outperforms both existing tools with a 96.7%true positive rate and a 0%false positive rate on average.展开更多
基金supported by a grant from the National Natural Science Foundation of China(81170181)a Program for Development of Innovative Research Team in the First Affiliated Hospital of Nanjing Medical Universitya Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutes(PAPD)
文摘We sought to assess the incidence of aspirin resistance after off-pump coronary artery bypass (OPCAB) surgery, and investigate whether clopidogrel can improve aspirin response and be safely applied early after OPCAB surgery. Sixty patients who underwent standard OPCAB surgery were randomized into two groups. One group (30 patients) received mono-antiplatelet treatment (MAPT) with aspirin 100 mg daily and the other group received dual anfiplatelet treatment (DAPT) with aspirin 100 mg daily plus clopidogrel 75 mg daily. Platelet aggregations in response to arachi- donic acid (PLAA) and adenosine diphosphate (ADP) (PLADP) were measured preoperatively and on days 1 to 6, 8 and 10 after the antiplatelet agents were administered. A PLAA level above 20% was defined as aspirin resistance. Postoperative bleeding and other perioperative variables were also recorded. There were no significant differences between the two groups in baseline characteristics, average number of distal anastomosis, operation time, postoperative bleeding, ventilation time and postoperative hospital stay. However, the incidence of aspirin resistance was significantly lower in the DAPT group than that in the MAPT group on the first and second day after antiplatelet agents were given (62.1% vs, 32.1%, 34.5% vs. 10.7%, respectively, both P 〈 0.05). There was no significant difference in postoperative complication between the two groups. DAPT with aspirin and clopidogrel can be safely applied to OPCAB patients early after the procedure. Moreover, clopidogrel reduces the incidence of OPCAB-related aspirin resistance.
基金supported in part by the following grants:Wenzhou key scientific and technological projects(No.ZG2020031)Researchers Supporting Project of King Saud University,Riyadh,Saudi Arabia(No.RSP-2020/102)+6 种基金National Natural Science Foundation of China under Grant(No.U1936215 and 61772026)Ministry of Industry and Information Technology of the People’s Republic of China under Grant(No.TC190H3WN)State Grid Corporation of China under Grant(No.5211XT19006B)Wenzhou Polytechnic research projects(No.WZY2020001)2020 industrial Internet innovation and development project(TC200H01V)Wenzhou Scientific Research Projects for Underdeveloped Areas(WenRenSheFa[2020]61(No.5)).Zhejiang key R&D projects(No.2021C01117).
文摘Internet traffic encryption is a very common traffic protection method.Most internet traffic is protected by the encryption protocol called transport layersecurity (TLS). Although traffic encryption can ensure the security of communication, it also enables malware to hide its information and avoid being detected.At present, most of the malicious traffic detection methods are aimed at the unencrypted ones. There are some problems in the detection of encrypted traffic, suchas high false positive rate, difficulty in feature extraction, and insufficient practicability. The accuracy and effectiveness of existing methods need to be improved.In this paper, we present TLSmell, a framework that conducts maliciousencrypted HTTPs traffic detection with simple connection-specific indicators byusing different classifiers based online training. We perform deep packet analysisof encrypted traffic through data pre-processing to extract effective features, andthen the online training algorithm is used for training and prediction. Withoutdecrypting the original traffic, high-precision malicious traffic detection and analysis are realized, which can guarantee user privacy and communication security.At the same time, since there is no need to decrypt the traffic in advance, the effi-ciency of detecting malicious HTTPs traffic will be greatly improved. Combinedwith the traditional detection and analysis methods, malicious HTTPs traffic isscreened, and suspicious traffic is further analyzed by the expert through the context of suspicious behaviors, thereby improving the overall performance of malicious encrypted traffic detection.
基金Financial supports by the National Natural Science Foundation of China(21776210 and 22008055)。
文摘A series of triphenylethoxysilane(TPEOS)-modified nanosheet HZSM-5 catalysts(ZN-x,x=4%,8%and16%,mass)were synthesized by chemical liquid deposition to selectively change external acidity distributions.TPEOS modification was found to passivate some external Br?nsted and Lewis acid sites by37.8%,in which Br?nsted acid sites(BAS)were found more easily sacrificed by breaking the surface Al AO bond of bridging hydroxyl groups and forming Si AOASi bonds.The selectivity of ZN-8 catalyst for light olefins(ethylene,propylene and butene)in n-decane catalytic cracking is up to 26%(450℃,WHSV=10.95 h^(-1)),which is ca.78%higher than that of parent one.The better performance was attributed to the appropriate external acid density in ZN-8,which inhibits bimolecular hydrogen transfer reaction of light olefins on the adjacent acid sites,resulting in more olefins,few coke precursors and thus an excellent catalytic stability.
基金This work was supported in part by the Guangdong Basic and Applied Basic Research Foundation under Key Project 2019B1515120032in part by the National Science Foundation of China(NSFC)with grant no.61901534+3 种基金in part by the Science,Technology and Innovation Commission of Shenzhen Municipality with grant no.JCYJ20190807155617099in part by the University Basic Research Fund 20lgpy43in part by the Guangdong Natural Science Foundation of Grant No.2019A1515011622the Foundation of Grant No.2019-JCJQ-JJ-411.
文摘In the Internet of vehicles(IoV),direct communication between vehicles,i.e.,vehicle-tovehicle(V2V)may have lower latency,compared to the schemes with help of Road Side Unit(RSU)or base station.In this paper,the scenario where the demands of a vehicle are satisfied by cooperative transmissions from those one in front is considered.Since the topology of the vehicle network is dynamic,random linear network coding is applied in such a multisource single-sink vehicle-to-vehicle network,where each vehicle is assumed to broadcast messages to others so that the intermediate vehicles between sources and sink can reduce the latency collaboratively.It is shown that the coding scheme can significantly reduce the time delay compared with the non-coding scheme even in the channels with high packet loss rate.In order to further optimize the coding scheme,one can increase the generation size,where the generation size means the number of raw data packets sent by the source node to the sink node in each round of communication.Under the premise of satisfying the coding validity,we can dynamically select the Galois field size according to the number of intermediate nodes.It is not surprised that the reduction in the Galois field size can further reduce the transmission latency.
文摘In order to more easily measure the concentration of solution with the Tyndall phenomenon in the outdoor, a portable instrument using imageprocessing for collecting and processing images of Tyndall phenomenon is proposed. The software and hardware of light measurement module of the portable instrument are described in this paper, including the selection of the incident light and the image sensor. Then the optical path of the captured picture was extracted and the light intensity value was calculated. Through the standard sample, the linear relationship between the light intensity in the Tyndall phenomenon and the concentration was fitted to determine the concentration of the colloidal liquid to be tested. Theoretical analysis and simulation results show that the method of obtaining the concentration of colloidal liquid by using the relationship between the RGB mean of the image and the light intensity of Tyndall can control the error within 10%, which meets the preliminary test requirements.
文摘When the red laser illuminates the lyosol, the Tyndall effect will form a light path with a certain distance, and the optical properties of the lyosol will have a certain influence on the Tyndall light intensity. This paper mainly aims at the theoretical and experimental studies on the change situation of the lyosol concentration and the attenuation characteristics of the light path when the red laser changes with the distance of the light path in the solution. In order to study the effect of lyosol concentration on the Tyndall light path, digital image technology was applied to the measurement of lyosol concentration. Due to the non-contact property of the image, the liquid concentration can be measured accurately in real time. The attenuation characteristics of the laser in the lyosol were obtained by image processing technology, and the quantitative relationship between the attenuation coefficient of the Tyndall light path and the lyosol concentration was obtained.
文摘Objective:To explore the role of midwifery care in the prevention of neonatal asphyxia.Method:The 100 cases of parturient received in our hospital from January 2018 to January 2021 were divided into two groups,respectively,the control group and the experimental group with 50 cases in each group.The control group received routine care,and the experimental group received midwifery care.The psychological status of the mothers and the occurrence of neonatal asphyxia were compared between the two groups.Results:Before nursing,there was no significant difference in the mental state of the two groups of parturient(P>0.05).After the nursing,the mental state of the parturient in the experimental group was significantly better than that of the control group(P<0.05);After different ways of nursing,the incidence of asphyxia in neonates in the control group was significantly higher than that in the experimental group(P<0.05),and the comparison between the groups was statistically significant.Conclusion:The timely delivery of midwifery care for parturient can improve the mental state of the parturient and help reduce the incidence of neonatal asphyxia.It is worthy of clinical attention and promotion.
基金Supported by Hippocampus Neural Coding Mechanism Research on Sini San Intervention Sleep Disorders of PTSD in Myospalax cansus from the National Natural Science Foundation(No.81460611)Study on Sini San for regulation of expression of proteins of drosophila brain of sleep deprivation of Gansu Province Natural Science Foundation(No.145RJZA076)+3 种基金Fundamental Research Funds for the Gansu Provincial Department of Finance Universities(No.2013-2)Mechanisms of hippocampal neurons based on Jiawei Sini San intervention coding mode PTSD sleep disordersMinistry of Education,Sini San for intervention of sleep deprivation in drosophila Based nano-2D-LC/MS technology of Science and Technology Key Project(No.212186)Proteomics and effective substance basic of Sini San for improving sleep of Gansu Province Natural Science Foundation(No.1010RJZA212)
文摘OBJECTIVE: To investigate the effects of the Sini San at different doses on each sleeping state[slow-wave sleep 1(SWS1), slow-wave sleep 2(SWS2), rapid-eye-movement(REM), wakefulness(W)] in insomnia rats and to identify its mode of ac-tion for improving sleep.METHODS: The insomnia rats were randomly divided into a high-, medium- or low-dose group of Sini San(equal to crude drug 8.8, 4.4, or 2.2 g/kg, respectively) for seven consecutive days.RESULTS: Compared with pre-administration,SWS2 was significantly increased after administration of the low dose. Compared with pre-administration, W was significantly decreased and SWS1,SWS2, and the total sleeping time(TST) were markedly increased after administration of the medium dose. Compared with pre-administration, W was significantly decreased and SWS1, SWS2, rapid-eye-movement sleep, and TST were significantly longer after administration of the high dose. The effects of Sini San on sleep-wake cycle are dose-dependent.CONCLUSION: The results suggest that Sini San extends SWS1 and SWS2, which increases the total sleeping time.
基金This study was supported by research grants from Key R&D Program Projects in Zhejiang Province(2019C03045)the National Major Equipment Program of China(2012YQ12008004)+1 种基金the National Key Research and Development Program of China(2016YFE0107000)the National Nature Science Foundation of China(Grant No.81570880).
文摘Purpose:To develop an automated classification system using a machine learning classifier to distinguish clinically unaffected eyes in patients with keratoconus from a normal control population based on a combination of Scheimpflug camera images and ultra-high-resolution optical coherence tomography(UHR-OCT)imaging data.Methods:A total of 121 eyes from 121 participants were classified by 2 cornea experts into 3 groups:normal(50 eyes),with keratoconus(38 eyes)or with subclinical keratoconus(33 eyes).All eyes were imaged with a Scheimpflug camera and UHR-OCT.Corneal morphological features were extracted from the imaging data.A neural network was used to train a model based on these features to distinguish the eyes with subclinical keratoconus from normal eyes.Fisher’s score was used to rank the differentiable power of each feature.The receiver operating characteristic(ROC)curves were calculated to obtain the area under the ROC curves(AUCs).Results:The developed classification model used to combine all features from the Scheimpflug camera and UHR-OCT dramatically improved the differentiable power to discriminate between normal eyes and eyes with subclinical keratoconus(AUC=0.93).The variation in the thickness profile within each individual in the corneal epithelium extracted from UHR-OCT imaging ranked the highest in differentiating eyes with subclinical keratoconus from normal eyes.Conclusion:The automated classification system using machine learning based on the combination of Scheimpflug camera data and UHR-OCT imaging data showed excellent performance in discriminating eyes with subclinical keratoconus from normal eyes.The epithelial features extracted from the OCT images were the most valuable in the discrimination process.This classification system has the potential to improve the differentiable power of subclinical keratoconus and the efficiency of keratoconus screening.
基金Supported by Gansu Province Finance colleges Fundamental Research Foundation (No.2013-2)Ministry of Education,Science and Technology Key Project (No.212186)and Gansu Province Natural Science Foundation (No.1010RJZA212)
文摘OBJECTIVE: To investigate the sedative and hypnotic activity of paeoniflorin and freeze-dried Sini San powder on mice and provide a reliable method for determining the pharmacodynamic material basis of Sini San.METHODS: Male adult mice weighing 20-22 g were used in this study. Three experiments were carried out. Synergism with pentobarbital was used as an index for hypnotic effect. Loss of the righting reflex was used to determine the start of sleep.Sleep latency and sleeping time were recorded in each experiment.RESULTS: The coefficient of variation of the suprathreshold dose(55 mg/kg) was significantly lower than that of the threshold dose. The sleep latency of mice was significantly decreased, and the sleeping time of mice was significantly prolonged. The effects of paeoniflorin and Sini San on prolonging the sleeping time of mice induced by pentobarbital sodium were significantly stronger than those in the control group.CONCLUSION: Paeoniflorin produces significant sedative and hypnotic effects, and there is an obvious dose-effect relationship.
基金This work was supported by the National Key Research and Development Program of China[2017YFC0504704]National Natural Science Foundation of China[41601092,41731289]+2 种基金National Geological Prospecting special[DD20190504]Shaanxi Province Innovation Talent Promotion Project Technology Innovation Team[Grant 2018TD-037]Shaanxi Provincial Technology Innovation Guidance Project[Grant 2017CGZH-HJ-06].
文摘There is debating over the question of whether the large-scale‘Grain for Green’program on the Loess Plateau of China threatens regional food security.Self-sufficiency index and cropland pressure index were used to assess food security on the Loess Plateau after the implementation of revegetation program.The results showed that the‘Grain for Green’program initially had a considerable impact on regional food security,where grain yield fell from 1999 to 2001,resulting in a lower grain self-sufficiency and increased farmland stress.Subsequently,grain yield in this region increased due to the elevated agricultural material input and increased construction of terraces and check dams.The grain self-sufficiency index would have increased to 96.55%if there were improvements to the agricultural conditions,such as fertilization and irrigation,which would have resulted in an increase in the crop yield per unit of 20%.However,the grain self-sufficiency increased to 105.25%via the construction of terraces and check dams.Thus,the government should further expand the‘Grain for Green’program in coordination with improvements to the agricultural production conditions and the construction of terraces and check dams on the Loess Plateau.
基金supported by the National Natural Science Foundation of China(No.U1936215)。
文摘In recent years,Power Shell has increasingly been reported as appearing in a variety of cyber attacks.However,because the PowerShell language is dynamic by design and can construct script fragments at different levels,state-of-the-art static analysis based Power Shell attack detection approaches are inherently vulnerable to obfuscations.In this paper,we design the first generic,effective,and lightweight deobfuscation approach for PowerShell scripts.To precisely identify the obfuscated script fragments,we define obfuscation based on the differences in the impacts on the abstract syntax trees of PowerShell scripts and propose a novel emulation-based recovery technology.Furthermore,we design the first semantic-aware PowerShell attack detection system that leverages the classic objective-oriented association mining algorithm and newly identifies 31 semantic signatures.The experimental results on 2342 benign samples and 4141 malicious samples show that our deobfuscation method takes less than 0.5 s on average and increases the similarity between the obfuscated and original scripts from 0.5%to 93.2%.By deploying our deobfuscation method,the attack detection rates for Windows Defender and VirusTotal increase substantially from 0.33%and 2.65%to 78.9%and 94.0%,respectively.Moreover,our detection system outperforms both existing tools with a 96.7%true positive rate and a 0%false positive rate on average.