基于深度神经网络的目标检测技术已经广泛应用于各领域,然而,通过对抗补丁攻击在图像中添加局部扰动,以此来误导深度神经网络,对基于目标检测技术的视觉系统构成了严重威胁。针对这一问题,利用对抗补丁和图像背景的语义差异性,提出了一...基于深度神经网络的目标检测技术已经广泛应用于各领域,然而,通过对抗补丁攻击在图像中添加局部扰动,以此来误导深度神经网络,对基于目标检测技术的视觉系统构成了严重威胁。针对这一问题,利用对抗补丁和图像背景的语义差异性,提出了一种基于PatchTracker的对抗补丁防御算法,该算法由上游补丁检测器与下游数据增强模块组成。上游补丁检测器使用带有注意力机制的YOLOV5(you only look once-v5)确定对抗补丁所在位置,有助于提高对小尺度对抗补丁的检测精度;将检测区域用合适的像素值覆盖以抹除对抗补丁,上游补丁检测器不仅能够有效降低对抗样本的攻击性,而且不依赖大规模的训练数据;下游数据增强模块通过改进模型训练范式,提高下游目标检测器的鲁棒性;将抹除补丁后的图像输入经过数据增强的下游YOLOV5目标检测模型。在公开的TT100K交通标志数据集上进行了交叉验证,实验表明,与未采取防御措施相比,所提算法能够有效防御多种类型的通用对抗补丁攻击,在检测对抗补丁图像时的mAP(mean average precision)提高65%左右,有效地改善了小尺度对抗补丁的漏检情况。与现有算法比较,所提算法有效提高了神经网络在检测对抗样本时的准确率。此外,所提算法不涉及下游模型结构的修改,具有良好的兼容性。展开更多
Early screening of diabetes retinopathy(DR)plays an important role in preventing irreversible blindness.Existing research has failed to fully explore effective DR lesion information in fundus maps.Besides,traditional ...Early screening of diabetes retinopathy(DR)plays an important role in preventing irreversible blindness.Existing research has failed to fully explore effective DR lesion information in fundus maps.Besides,traditional attention schemes have not considered the impact of lesion type differences on grading,resulting in unreasonable extraction of important lesion features.Therefore,this paper proposes a DR diagnosis scheme that integrates a multi-level patch attention generator(MPAG)and a lesion localization module(LLM).Firstly,MPAGis used to predict patches of different sizes and generate a weighted attention map based on the prediction score and the types of lesions contained in the patches,fully considering the impact of lesion type differences on grading,solving the problem that the attention maps of lesions cannot be further refined and then adapted to the final DR diagnosis task.Secondly,the LLM generates a global attention map based on localization.Finally,the weighted attention map and global attention map are weighted with the fundus map to fully explore effective DR lesion information and increase the attention of the classification network to lesion details.This paper demonstrates the effectiveness of the proposed method through extensive experiments on the public DDR dataset,obtaining an accuracy of 0.8064.展开更多
In recent years,the field of mechanomaterials has emerged at the interface of mechanics,materials science,biology,medicine and data science,where materials are proactively designed or programmed to achieve targeted fu...In recent years,the field of mechanomaterials has emerged at the interface of mechanics,materials science,biology,medicine and data science,where materials are proactively designed or programmed to achieve targeted functionalities by leveraging the fundamental mechanics principles and force-geometry-property relationships.In the biological context,one may likewise introduce mechanobiomaterials as a field with the following goals:(1)proactive design or programming of materials for precisely mediating biomechanical environment of living systems for tissue repair/restoration;(2)proactive control/programming of living systems themselves by an external field via force-structure-function relationships.Here,we will discuss an example of research in mechanobiomaterials on using mechanics to guide the design of acellular epicardial patches for the treatment of myocardial infarction.This technology aims to employ a biocompatible material patch to help reverse left ventricular remodeling and restore heart function after myocardial infarction by increasing the mechanical integrity of damaged heart tissues.However,its application is currently limited by widely scattered therapeutic efficacy.Here,we develop a biomechanics-based simulation platform that allows us to test,design and optimize the performance of an epicardial patch.We show that the widely scattered therapeutic efficacy of this technology can be attributed to a“pre-strain sensitivity”caused by attaching an elastic patch to a dynamically beating heart.To mitigate this challenge,we introduce a viscoelastic epicardial patch,designed at the so-called‘gel point’of the material,that effectively accommodates the cyclic deformation of the myocardium.This then leads to the fabrication and experimentally validated epicardial patch that outperforms all existing ones in restoring heart function after both acute and subacute myocardial infarction in rats.Our study also demonstrates the potential of employing viscoelastic interfaces for better integration of synthetic materials with biological tissues.展开更多
The development of bare patches typically signifies a process of ecosystem degradation.Within the protection system of Shapotou section of the Baotou-Lanzhou railway,the extensive emergence of bare sand patches poses ...The development of bare patches typically signifies a process of ecosystem degradation.Within the protection system of Shapotou section of the Baotou-Lanzhou railway,the extensive emergence of bare sand patches poses a threat to both stability and sustainability.However,there is limited knowledge regarding the morphology,dynamic changes,and ecological responses associated with these sand patches.Therefore,we analyzed the formation and development process of sand patches within the protection system and its effects on herbaceous vegetation growth and soil nutrients through field observation,survey,and indoor analysis methods.The results showed that sand patch development can be divided into three stages,i.e.,formation,expansion,and stabilization,which correspond to the initial,actively developing,and semi-fixed sand patches,respectively.The average dimensions of all sand patch erosional areas were found to be 7.72 m in length,3.91 m in width,and 0.32 m in depth.The actively developing sand patches were the largest,and the initial sand patches were the smallest.Throughout the stage of formation and expansion,the herbaceous community composition changed,and the plant density decreased by more than 50.95%.Moreover,the coverage and height of herbaceous plants decreased in the erosional area and slightly increased in the depositional lobe;and the fine particles and nutrients of soils in the erosional area and depositional lobe showed a decreasing trend.In the stabilization phases of sand patches,the area from the inlet to the bottom of sand patches becomes initially covered with crusts.Vegetation and 0-2 cm surface soil condition improved in the erosional area,but this improvement was not yet evident in the depositional lobe.Factors such as disturbance,climate change,and surface resistance to erosion exert notable influences on the formation and dynamics of sand patches.The results can provide evidence for the future treatment of sand patches and the management of the protection system of Shapotou section of the Baotou-Lanzhou railway.展开更多
Many birds develop brood patches on their ventral apterium under hormonal regulation to effectively transmit body heat to eggs during incubation.The developed patch has several characteristics,including de-feathering,...Many birds develop brood patches on their ventral apterium under hormonal regulation to effectively transmit body heat to eggs during incubation.The developed patch has several characteristics,including de-feathering,vascularization,and edema.However,little is known about whether avian brood parasites that do not incubate their eggs exhibit brood patch development during the breeding season.In this study,we measured the size of the ventral apterium in 114 Common Cuckoos(Cuculus canorus)captured in the field throughout the breeding season and examined the appearance of the ventral apterium to confirm the development of brood patches.We also examined whether morphological traits and various factors correlated with the size of the ventral apterium(sternal apterium and abdominal apterium)and how it changed during the breeding season.We found no clear signs of brood patch development in Common Cuckoos captured throughout the breeding season,indicating that they likely did not develop brood patches on the ventral apterium during this period.We also found that ventral apterium size was positively correlated with wing length and body weight.In addition,Common Cuckoos with newly growing feathers on the boundary of the ventral apterium with pteryla were frequently observed as seasons progressed to the end.In conclusion,Common Cuckoos exhibit neither brood patch development nor the vestigial characteristics of ancestral brood patches,except for the growth of feathers on boundary the ventral apterium.Further studies examining brood patches across different groups of avian brood parasites are valuable for enhancing our understanding of the developmental and physiological adaptations of avian brood parasites.展开更多
Artificial skin involves multidisciplinary efforts,including materials science,biology,medicine,and tissue engineering.Recent studies have aimed at creating skins that are multifunctional,intelligent,and capable of re...Artificial skin involves multidisciplinary efforts,including materials science,biology,medicine,and tissue engineering.Recent studies have aimed at creating skins that are multifunctional,intelligent,and capable of regenerating tissue.In this work,we present a specialized 3D printing ink composed of polyurethane and bioactive glass(PU-BG)and prepare dual-function skin patch by microfluidic-regulated 3D bioprinting(MRBP)technique.The MRBP endows the skin patch with a highly controlled microstructure and superior strength.Besides,an asymmetric tri-layer is further constructed,which promotes cell attachment and growth through a dual transport mechanism based on hydrogen bonds and gradient structure from hydrophilic to superhydrophilic.More importantly,by combining the features of biomedical skin with electronic skin(e-skin),we achieved a biomedical and electronic dual-function skin patch.In vivo experiments have shown that this skin patch can enhance hemostasis,resist bacterial growth,stimulate the regeneration of blood vessels,and accelerate the healing process.Meanwhile,it also mimics the sensory functions of natural skin to realize signal detection,where the sensitivity reached up to 5.87 kPa1,as well as cyclic stability(over 500 cycles),a wide detection range of 0–150 kPa,high pressure resolution of 0.1%under the pressure of 100 kPa.This work offers a versatile and effective method for creating dual-function skin patches and provide new insights into wound healing and tissue repair,which have significant implications for clinical applications.展开更多
文摘基于深度神经网络的目标检测技术已经广泛应用于各领域,然而,通过对抗补丁攻击在图像中添加局部扰动,以此来误导深度神经网络,对基于目标检测技术的视觉系统构成了严重威胁。针对这一问题,利用对抗补丁和图像背景的语义差异性,提出了一种基于PatchTracker的对抗补丁防御算法,该算法由上游补丁检测器与下游数据增强模块组成。上游补丁检测器使用带有注意力机制的YOLOV5(you only look once-v5)确定对抗补丁所在位置,有助于提高对小尺度对抗补丁的检测精度;将检测区域用合适的像素值覆盖以抹除对抗补丁,上游补丁检测器不仅能够有效降低对抗样本的攻击性,而且不依赖大规模的训练数据;下游数据增强模块通过改进模型训练范式,提高下游目标检测器的鲁棒性;将抹除补丁后的图像输入经过数据增强的下游YOLOV5目标检测模型。在公开的TT100K交通标志数据集上进行了交叉验证,实验表明,与未采取防御措施相比,所提算法能够有效防御多种类型的通用对抗补丁攻击,在检测对抗补丁图像时的mAP(mean average precision)提高65%左右,有效地改善了小尺度对抗补丁的漏检情况。与现有算法比较,所提算法有效提高了神经网络在检测对抗样本时的准确率。此外,所提算法不涉及下游模型结构的修改,具有良好的兼容性。
基金supported in part by the Research on the Application of Multimodal Artificial Intelligence in Diagnosis and Treatment of Type 2 Diabetes under Grant No.2020SK50910in part by the Hunan Provincial Natural Science Foundation of China under Grant 2023JJ60020.
文摘Early screening of diabetes retinopathy(DR)plays an important role in preventing irreversible blindness.Existing research has failed to fully explore effective DR lesion information in fundus maps.Besides,traditional attention schemes have not considered the impact of lesion type differences on grading,resulting in unreasonable extraction of important lesion features.Therefore,this paper proposes a DR diagnosis scheme that integrates a multi-level patch attention generator(MPAG)and a lesion localization module(LLM).Firstly,MPAGis used to predict patches of different sizes and generate a weighted attention map based on the prediction score and the types of lesions contained in the patches,fully considering the impact of lesion type differences on grading,solving the problem that the attention maps of lesions cannot be further refined and then adapted to the final DR diagnosis task.Secondly,the LLM generates a global attention map based on localization.Finally,the weighted attention map and global attention map are weighted with the fundus map to fully explore effective DR lesion information and increase the attention of the classification network to lesion details.This paper demonstrates the effectiveness of the proposed method through extensive experiments on the public DDR dataset,obtaining an accuracy of 0.8064.
文摘In recent years,the field of mechanomaterials has emerged at the interface of mechanics,materials science,biology,medicine and data science,where materials are proactively designed or programmed to achieve targeted functionalities by leveraging the fundamental mechanics principles and force-geometry-property relationships.In the biological context,one may likewise introduce mechanobiomaterials as a field with the following goals:(1)proactive design or programming of materials for precisely mediating biomechanical environment of living systems for tissue repair/restoration;(2)proactive control/programming of living systems themselves by an external field via force-structure-function relationships.Here,we will discuss an example of research in mechanobiomaterials on using mechanics to guide the design of acellular epicardial patches for the treatment of myocardial infarction.This technology aims to employ a biocompatible material patch to help reverse left ventricular remodeling and restore heart function after myocardial infarction by increasing the mechanical integrity of damaged heart tissues.However,its application is currently limited by widely scattered therapeutic efficacy.Here,we develop a biomechanics-based simulation platform that allows us to test,design and optimize the performance of an epicardial patch.We show that the widely scattered therapeutic efficacy of this technology can be attributed to a“pre-strain sensitivity”caused by attaching an elastic patch to a dynamically beating heart.To mitigate this challenge,we introduce a viscoelastic epicardial patch,designed at the so-called‘gel point’of the material,that effectively accommodates the cyclic deformation of the myocardium.This then leads to the fabrication and experimentally validated epicardial patch that outperforms all existing ones in restoring heart function after both acute and subacute myocardial infarction in rats.Our study also demonstrates the potential of employing viscoelastic interfaces for better integration of synthetic materials with biological tissues.
基金supported by the Key Research and Development Program of Ningxia Hui Autonomous Region,China(2022BEG02003)the Excellent Member of Youth Innovation Promotion Association,Chinese Academy of Sciences(Y202085)the Youth Innovation Promotion Association,Chinese Academy of Sciences(2023448).
文摘The development of bare patches typically signifies a process of ecosystem degradation.Within the protection system of Shapotou section of the Baotou-Lanzhou railway,the extensive emergence of bare sand patches poses a threat to both stability and sustainability.However,there is limited knowledge regarding the morphology,dynamic changes,and ecological responses associated with these sand patches.Therefore,we analyzed the formation and development process of sand patches within the protection system and its effects on herbaceous vegetation growth and soil nutrients through field observation,survey,and indoor analysis methods.The results showed that sand patch development can be divided into three stages,i.e.,formation,expansion,and stabilization,which correspond to the initial,actively developing,and semi-fixed sand patches,respectively.The average dimensions of all sand patch erosional areas were found to be 7.72 m in length,3.91 m in width,and 0.32 m in depth.The actively developing sand patches were the largest,and the initial sand patches were the smallest.Throughout the stage of formation and expansion,the herbaceous community composition changed,and the plant density decreased by more than 50.95%.Moreover,the coverage and height of herbaceous plants decreased in the erosional area and slightly increased in the depositional lobe;and the fine particles and nutrients of soils in the erosional area and depositional lobe showed a decreasing trend.In the stabilization phases of sand patches,the area from the inlet to the bottom of sand patches becomes initially covered with crusts.Vegetation and 0-2 cm surface soil condition improved in the erosional area,but this improvement was not yet evident in the depositional lobe.Factors such as disturbance,climate change,and surface resistance to erosion exert notable influences on the formation and dynamics of sand patches.The results can provide evidence for the future treatment of sand patches and the management of the protection system of Shapotou section of the Baotou-Lanzhou railway.
基金financially supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by The Ministry of Education(NRF-2020R1I1A2063567)。
文摘Many birds develop brood patches on their ventral apterium under hormonal regulation to effectively transmit body heat to eggs during incubation.The developed patch has several characteristics,including de-feathering,vascularization,and edema.However,little is known about whether avian brood parasites that do not incubate their eggs exhibit brood patch development during the breeding season.In this study,we measured the size of the ventral apterium in 114 Common Cuckoos(Cuculus canorus)captured in the field throughout the breeding season and examined the appearance of the ventral apterium to confirm the development of brood patches.We also examined whether morphological traits and various factors correlated with the size of the ventral apterium(sternal apterium and abdominal apterium)and how it changed during the breeding season.We found no clear signs of brood patch development in Common Cuckoos captured throughout the breeding season,indicating that they likely did not develop brood patches on the ventral apterium during this period.We also found that ventral apterium size was positively correlated with wing length and body weight.In addition,Common Cuckoos with newly growing feathers on the boundary of the ventral apterium with pteryla were frequently observed as seasons progressed to the end.In conclusion,Common Cuckoos exhibit neither brood patch development nor the vestigial characteristics of ancestral brood patches,except for the growth of feathers on boundary the ventral apterium.Further studies examining brood patches across different groups of avian brood parasites are valuable for enhancing our understanding of the developmental and physiological adaptations of avian brood parasites.
基金supported by National Natural Science Foundation of China(22278225,82170581,22308160)Natural Science Foundation of Jiangsu Province(BK20211133,BK20230327)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX23_1471)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Artificial skin involves multidisciplinary efforts,including materials science,biology,medicine,and tissue engineering.Recent studies have aimed at creating skins that are multifunctional,intelligent,and capable of regenerating tissue.In this work,we present a specialized 3D printing ink composed of polyurethane and bioactive glass(PU-BG)and prepare dual-function skin patch by microfluidic-regulated 3D bioprinting(MRBP)technique.The MRBP endows the skin patch with a highly controlled microstructure and superior strength.Besides,an asymmetric tri-layer is further constructed,which promotes cell attachment and growth through a dual transport mechanism based on hydrogen bonds and gradient structure from hydrophilic to superhydrophilic.More importantly,by combining the features of biomedical skin with electronic skin(e-skin),we achieved a biomedical and electronic dual-function skin patch.In vivo experiments have shown that this skin patch can enhance hemostasis,resist bacterial growth,stimulate the regeneration of blood vessels,and accelerate the healing process.Meanwhile,it also mimics the sensory functions of natural skin to realize signal detection,where the sensitivity reached up to 5.87 kPa1,as well as cyclic stability(over 500 cycles),a wide detection range of 0–150 kPa,high pressure resolution of 0.1%under the pressure of 100 kPa.This work offers a versatile and effective method for creating dual-function skin patches and provide new insights into wound healing and tissue repair,which have significant implications for clinical applications.
