Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone...Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone wound healing. The findings of recent studies suggest that the use of selective serotonin reuptake inhibitors(SSRIs) can reduce bone mass, precipitate osteoporotic fractures and increase the rate of dental implant failure. With 10% of Americans prescribed antidepressants, the potential of SSRIs to impair bone healing may adversely affect millions of patients’ ability to heal after sustaining trauma. Here, we investigate the effect of the SSRI sertraline on bone healing through pre-treatment with(10 mg·kg-1sertraline in drinking water, n = 26) or without(control, n = 30) SSRI followed by the creation of a 5-mm calvarial defect. Animals were randomized into three surgical groups:(a) empty/sham,(b) implanted with a DermaMatrix scaffold soak-loaded with sterile PBS or(c) DermaMatrix soak-loaded with542.5 ng BMP2. SSRI exposure continued until sacrifice in the exposed groups at 4 weeks after surgery. Sertraline exposure resulted in decreased bone healing with significant decreases in trabecular thickness, trabecular number and osteoclast dysfunction while significantly increasing mature collagen fiber formation. These findings indicate that sertraline exposure can impair bone wound healing through disruption of bone repair and regeneration while promoting or defaulting to scar formation within the defect site.展开更多
In integrated circuits, the defects associated with photolithography are assumed to be in the shape of circular discs in order to perform the estimation of yield and fault analysis. However,real defects exhibit a grea...In integrated circuits, the defects associated with photolithography are assumed to be in the shape of circular discs in order to perform the estimation of yield and fault analysis. However,real defects exhibit a great variety of shapes. In this paper,a novel yield model is presented and the critical area model of short circuit is correspondingly provided. In comparison with the circular model corrently available, the new model takes the similarity shape to an original defect, the two-dimensional distributional characteristic of defects, the feature of a layout routing and the character of yield estimation into account. As for the aspect of prediction of yield, the experimental results show that the new model may predict the yield caused by real defects more accurately than the circular model does. It is significant that the yield is accurately estimated and improved using the proposed model.展开更多
Studies on ZnO ceramic varistors by deep heat treatment at 650–900 C are reported. The current creep time curve exhibits a peak during the continuous action of a dc biasing voltage; the forwardV-l characteristic is i...Studies on ZnO ceramic varistors by deep heat treatment at 650–900 C are reported. The current creep time curve exhibits a peak during the continuous action of a dc biasing voltage; the forwardV-l characteristic is improved rather than degraded after the action of the biasing voltage. We assume that the zinc interstitial cations Zni are out diffused rapidly and the concentration of Zni in the depletion layer is decreased rapidly during deep heat treatment; the oxygen anions O’o could be accumulated at the grain interface if the out diffusion quantity of Zni is not enough to react with the O’o; the current creep phenomenon above results from the migration of the interface O’o by the biasing voltage. We suggest an improved grain boundary defect model for the ZnO varistors by deep heat treatment, and examine the model using the experimental data of lifetime positron-annihilation spectroscopy.展开更多
The biomechanical relationship between the articular cartilage defect and knee osteoarthritis (OA) has not been clearly defined. This study presents a 3D knee finite element model (FEM) to determine the effect of cart...The biomechanical relationship between the articular cartilage defect and knee osteoarthritis (OA) has not been clearly defined. This study presents a 3D knee finite element model (FEM) to determine the effect of cartilage defects on the stress distribution around the defect rim. The complete knee FEM, which includes bones, articular cartilages, menisci and ligaments, is developed from computed tomography and magnetic resonance images. This FEM then is validated and used to simulate femoral cartilage defects. Based on the obtained results, it is confirmed that the 3D knee FEM is reconstructed with high-fidelity level and can faithfully predict the knee contact behavior. Cartilage defects drastically affect the stress distribution on articular cartilages. When the defect size was smaller than 1.00cm2, the stress elevation and redistribution were found undistinguishable. However, significant stress elevation and redistribution were detected due to the large defect sizes ( 1.00cm2). This alteration of stress distribution has important implications relating to the progression of cartilage defect to OA in the human knee joint.展开更多
The importance of software residual defects and some prediction residual defects models are introduced. The problem that is not easy adapted to a general model is discussed. The model of prediction residual defects ba...The importance of software residual defects and some prediction residual defects models are introduced. The problem that is not easy adapted to a general model is discussed. The model of prediction residual defects based on BBNs is proposed and the detailed processes of the approach are given.展开更多
The pile, as an important foundation style, is being used in engineering practice. Defects of different types and damages of different degrees easily occur during the process of pile construction. So, dietecting defec...The pile, as an important foundation style, is being used in engineering practice. Defects of different types and damages of different degrees easily occur during the process of pile construction. So, dietecting defects of the pile is very important. As so far, there are some difficult problems in pile defect detection. Based on stress wave theory, some of these typical difficult problems were studied through model tests. The analyses of the test results are carried out and some significant results of the low-strain method are obtained, when a pile has a gradually-decreasing crosssection part, the amplitude of the reflective signal originating from the defect is dependent on the decreasing value of the rate of crosssection β. No apparent signal reflected from the necking appeares on the velocity response curve when the value of β is less than about 3. 5 %.展开更多
Contaminated surfaces of the feedstock materials in aluminum alloy casting processes often produce various types of defects which can affect the tensile properties of the final products as well as their fatigue reliab...Contaminated surfaces of the feedstock materials in aluminum alloy casting processes often produce various types of defects which can affect the tensile properties of the final products as well as their fatigue reliabilities.Semi-solid processing takes advantage of a much higher apparent viscosity of the die cast materials by limiting the risk of oxides formed at the free surfaces to become incorporated into the casting when the material is injected into the die.Most of existing semi-solid processes that use billets as feedstock material are however tied up with a different type of contaminated surface.During the injection phase,the external-skin on the periphery of the billet,which has been in contact with air and lubricant during the transfer in the shot sleeve,can be incorporated into the casting.When subjected to a heat treatment,the lubricant is decomposed and produces lens shape porosities.This might be a cause of reject for most structural parts.To avoid this kind of defects,the paths along which the billet skin evolves must be controlled during filling.In order to investigate the possibility of skin inclusion into cast parts during injection of the billet,a two-phase finite element mixture model is employed to model the metal flow.The formation of a skin on the periphery of the billet is modeled by setting an initial solid phase concentration profile in the radial direction.Microscopic observations of the real castings show that the approach is able to model the shear layers and to predict the paths along which the"lens porosity"defects could be formed.An Arbitrary Eulerian-Lagangian(ALE) method is also investigated and appears to be very promising to follow the skin movement in the casting.展开更多
The shrinkage defect of a ductile iron casting is attributed to the volume variations occurring in solidification, which consist of liquid contraction, solidification shrinkage, graphitization expansion, and mold cavi...The shrinkage defect of a ductile iron casting is attributed to the volume variations occurring in solidification, which consist of liquid contraction, solidification shrinkage, graphitization expansion, and mold cavity enlargement. Based on this understanding, a mathematical model for predicting the shrinkage defect of the casting is developed, in which the volume variations of the casting in soli- dification are numerically simulated, especially, the mold cavity enlargement is quantitatively calculated. Moreover, the reliability of the model is verified in production and experiment.展开更多
The oscillating voltage test is a nondestructive detection method for partial discharge of XLPE （cross linked polyethylene） cable and has been applied recently. This paper made three kinds of varying severity artifi...The oscillating voltage test is a nondestructive detection method for partial discharge of XLPE （cross linked polyethylene） cable and has been applied recently. This paper made three kinds of varying severity artificial defect models of cable joints in 10 kV XLPE cable. Oscillating voltage is applied to the model, by use of pulse current method to detect partial discharge signals. In order to study the statistical characteristics of partial discharge of cable joint under the oscillating voltage, three-dimensional statistical map has been made. The results show that for the same kind of defects, with the increases of the defect severity, the discharge interval extended, the magnitude and the number of partial discharge increase, for different kinds of defects, obvious differences exist among the maps, this may established a foundation for the further study of the partial discharge pattern recognition of XLPE cable under oscillating voltage.展开更多
大语言模型(Large Language Model, LLM),尤其是一些预训练的深度神经网络,拥有强大的表征学习能力,不仅能学习典型的软件缺陷,还能够深度分析软件隐含的缺陷,给出风险提示和改进建议。大模型的应用,使得测试方法和流程更加智能化,且能...大语言模型(Large Language Model, LLM),尤其是一些预训练的深度神经网络,拥有强大的表征学习能力,不仅能学习典型的软件缺陷,还能够深度分析软件隐含的缺陷,给出风险提示和改进建议。大模型的应用,使得测试方法和流程更加智能化,且能够发现之前难以捕捉的复杂缺陷。航天器软件以其独特性、专业性、复杂性、高可靠性、高安全性的特点,需要通过专业的方法训练专业的大模型来满足航天嵌入式软件测试的需要。研究表明,大模型结合有效的测试方法形成的完备思维链(Chain of Thought, Cot)可以有效提高软件缺陷检出率。将测试专家的思维和大模型相结合,用专家思维链引导大模型查找软件缺陷,在提示词中增加测试专家的思维链可以有效提升软件缺陷检出效率,保证软件质量,显著提升测试团队的整体专业水平。展开更多
Despite the fact that a number of approaches have been proposed for effective and accurate prediction of software defects, yet most of these have not found widespread applicability. Our objective in this communication...Despite the fact that a number of approaches have been proposed for effective and accurate prediction of software defects, yet most of these have not found widespread applicability. Our objective in this communication is to provide a framework which is expected to be more effective and acceptable for predicting the defects in multiple phases across software development lifecycle. The proposed framework is based on the use of neural networks for predicting defects in software development life cycle. Further, in order to facilitate the easy use of the framework by project managers, a software graphical user interface has been developed that allows input data (including effort and defect) to be fed easily for predicting defects. The proposed framework provides a probabilistic defect prediction approach where instead of a definite number, a defect range (minimum, maximum, and mean) is predicted. The claim of efficacy and superiority of proposed framework is established through results of a comparative study, involving the proposed frame-work and some well-known models for software defect prediction.展开更多
In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal la...In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal layout design exhibit a great variety of shapes. Based on mathematical morphology, a new critical area model is presented, which can be used to estimate the critical area of short circuit, open circuit and pinhole. Based on the new model, the efficient validity check algorithms are explored to extract critical areas of short circuit, open circuit and pinhole from layouts. The results of experiment on an approximate layout of 4 × 4 shifts register show that the new model predicts the critical areas accurately. These results suggest that the proposed model and algorithm could provide new approaches for yield prediction.展开更多
背景:H型血管因其独特的功能为深入理解血管介导的骨代谢调控机制提供了新的视角和切入点。目的:探讨H型血管在不同骨骼疾病动物模型中的生成机制及对骨代谢的影响。方法:系统检索CNKI、维普、万方、PubMed、Scopus和Web of Science数...背景:H型血管因其独特的功能为深入理解血管介导的骨代谢调控机制提供了新的视角和切入点。目的:探讨H型血管在不同骨骼疾病动物模型中的生成机制及对骨代谢的影响。方法:系统检索CNKI、维普、万方、PubMed、Scopus和Web of Science数据库中2014年1月至2025年2月收录的H型血管相关中英文文献。剔除重复及不符合纳入标准的文献,对141篇涉及不同骨骼疾病动物模型中H型血管生成的文献进行系统分析。结果与结论:研究表明,H型血管在不同的骨骼疾病模型中表现出特定的生成机制和生物学功能。H型血管不仅在骨内血管生成中发挥重要作用,还与骨代谢密切相关,能够作为评估骨量水平的早期标志物。不同骨骼疾病动物模型中H型血管生成及作用不尽相同。在骨质疏松症、骨折、骨坏死等骨骼疾病中,通过促进H型血管表达,可显著改善血管重塑与骨再生能力;而在骨关节炎、骨肿瘤等恶性骨骼疾病中,选择性抑制H型血管表达则成为潜在的治疗干预策略。研究还揭示了多条关键信号通路在H型血管生成中的重要作用,如缺氧诱导因子1α/血管内皮生长因子、血小板源性生长因子BB、Wnt/β-catenin等,为理解血管介导的骨代谢调控机制提供了新的科学视角,同时为H型血管作为潜在治疗靶点的临床应用价值提供了重要理论基础。通过分析不同骨骼疾病动物模型中H型血管生成的作用,将为进一步深入探究人类骨关节疾病机制及治疗靶点提供重要依据。展开更多
基金supported by a grant from the Musculoskeletal Transplant Foundation (JC)the National Institute of Health, the National Institute of Aging [NIH-NIA PO1-AG036675] (ME, WDH)+4 种基金in part by the Department of Veterans Affairs (VA Merit Award BX000333, ACL 1I01CX000930-01, WDH)funded through a training grant from the National Institutes of Health National Institute of Dental and Craniofacial Research [5T32DE017551]S.H. is funded through a fellowship from the National Institutes of Health National Institute of Dental and Craniofacial Research [5F32DE02471202]supported by the National Institutes of Health National Institute of General Medicine [P30GM103331]
文摘Bone wound healing is a highly dynamic and precisely controlled process through which damaged bone undergoes repair and complete regeneration. External factors can alter this process, leading to delayed or failed bone wound healing. The findings of recent studies suggest that the use of selective serotonin reuptake inhibitors(SSRIs) can reduce bone mass, precipitate osteoporotic fractures and increase the rate of dental implant failure. With 10% of Americans prescribed antidepressants, the potential of SSRIs to impair bone healing may adversely affect millions of patients’ ability to heal after sustaining trauma. Here, we investigate the effect of the SSRI sertraline on bone healing through pre-treatment with(10 mg·kg-1sertraline in drinking water, n = 26) or without(control, n = 30) SSRI followed by the creation of a 5-mm calvarial defect. Animals were randomized into three surgical groups:(a) empty/sham,(b) implanted with a DermaMatrix scaffold soak-loaded with sterile PBS or(c) DermaMatrix soak-loaded with542.5 ng BMP2. SSRI exposure continued until sacrifice in the exposed groups at 4 weeks after surgery. Sertraline exposure resulted in decreased bone healing with significant decreases in trabecular thickness, trabecular number and osteoclast dysfunction while significantly increasing mature collagen fiber formation. These findings indicate that sertraline exposure can impair bone wound healing through disruption of bone repair and regeneration while promoting or defaulting to scar formation within the defect site.
文摘In integrated circuits, the defects associated with photolithography are assumed to be in the shape of circular discs in order to perform the estimation of yield and fault analysis. However,real defects exhibit a great variety of shapes. In this paper,a novel yield model is presented and the critical area model of short circuit is correspondingly provided. In comparison with the circular model corrently available, the new model takes the similarity shape to an original defect, the two-dimensional distributional characteristic of defects, the feature of a layout routing and the character of yield estimation into account. As for the aspect of prediction of yield, the experimental results show that the new model may predict the yield caused by real defects more accurately than the circular model does. It is significant that the yield is accurately estimated and improved using the proposed model.
文摘Studies on ZnO ceramic varistors by deep heat treatment at 650–900 C are reported. The current creep time curve exhibits a peak during the continuous action of a dc biasing voltage; the forwardV-l characteristic is improved rather than degraded after the action of the biasing voltage. We assume that the zinc interstitial cations Zni are out diffused rapidly and the concentration of Zni in the depletion layer is decreased rapidly during deep heat treatment; the oxygen anions O’o could be accumulated at the grain interface if the out diffusion quantity of Zni is not enough to react with the O’o; the current creep phenomenon above results from the migration of the interface O’o by the biasing voltage. We suggest an improved grain boundary defect model for the ZnO varistors by deep heat treatment, and examine the model using the experimental data of lifetime positron-annihilation spectroscopy.
基金the National Natural Science Foundation of China (No. 81071235)the Medicine and Engineering Interdisciplinary Fund of Shanghai Jiaotong University (No. YG2010MS26)
文摘The biomechanical relationship between the articular cartilage defect and knee osteoarthritis (OA) has not been clearly defined. This study presents a 3D knee finite element model (FEM) to determine the effect of cartilage defects on the stress distribution around the defect rim. The complete knee FEM, which includes bones, articular cartilages, menisci and ligaments, is developed from computed tomography and magnetic resonance images. This FEM then is validated and used to simulate femoral cartilage defects. Based on the obtained results, it is confirmed that the 3D knee FEM is reconstructed with high-fidelity level and can faithfully predict the knee contact behavior. Cartilage defects drastically affect the stress distribution on articular cartilages. When the defect size was smaller than 1.00cm2, the stress elevation and redistribution were found undistinguishable. However, significant stress elevation and redistribution were detected due to the large defect sizes ( 1.00cm2). This alteration of stress distribution has important implications relating to the progression of cartilage defect to OA in the human knee joint.
基金The sustentation fund come fron China Academy of Engineering Physics 2003-421050504-12-02
文摘The importance of software residual defects and some prediction residual defects models are introduced. The problem that is not easy adapted to a general model is discussed. The model of prediction residual defects based on BBNs is proposed and the detailed processes of the approach are given.
文摘The pile, as an important foundation style, is being used in engineering practice. Defects of different types and damages of different degrees easily occur during the process of pile construction. So, dietecting defects of the pile is very important. As so far, there are some difficult problems in pile defect detection. Based on stress wave theory, some of these typical difficult problems were studied through model tests. The analyses of the test results are carried out and some significant results of the low-strain method are obtained, when a pile has a gradually-decreasing crosssection part, the amplitude of the reflective signal originating from the defect is dependent on the decreasing value of the rate of crosssection β. No apparent signal reflected from the necking appeares on the velocity response curve when the value of β is less than about 3. 5 %.
文摘Contaminated surfaces of the feedstock materials in aluminum alloy casting processes often produce various types of defects which can affect the tensile properties of the final products as well as their fatigue reliabilities.Semi-solid processing takes advantage of a much higher apparent viscosity of the die cast materials by limiting the risk of oxides formed at the free surfaces to become incorporated into the casting when the material is injected into the die.Most of existing semi-solid processes that use billets as feedstock material are however tied up with a different type of contaminated surface.During the injection phase,the external-skin on the periphery of the billet,which has been in contact with air and lubricant during the transfer in the shot sleeve,can be incorporated into the casting.When subjected to a heat treatment,the lubricant is decomposed and produces lens shape porosities.This might be a cause of reject for most structural parts.To avoid this kind of defects,the paths along which the billet skin evolves must be controlled during filling.In order to investigate the possibility of skin inclusion into cast parts during injection of the billet,a two-phase finite element mixture model is employed to model the metal flow.The formation of a skin on the periphery of the billet is modeled by setting an initial solid phase concentration profile in the radial direction.Microscopic observations of the real castings show that the approach is able to model the shear layers and to predict the paths along which the"lens porosity"defects could be formed.An Arbitrary Eulerian-Lagangian(ALE) method is also investigated and appears to be very promising to follow the skin movement in the casting.
文摘The shrinkage defect of a ductile iron casting is attributed to the volume variations occurring in solidification, which consist of liquid contraction, solidification shrinkage, graphitization expansion, and mold cavity enlargement. Based on this understanding, a mathematical model for predicting the shrinkage defect of the casting is developed, in which the volume variations of the casting in soli- dification are numerically simulated, especially, the mold cavity enlargement is quantitatively calculated. Moreover, the reliability of the model is verified in production and experiment.
文摘The oscillating voltage test is a nondestructive detection method for partial discharge of XLPE （cross linked polyethylene） cable and has been applied recently. This paper made three kinds of varying severity artificial defect models of cable joints in 10 kV XLPE cable. Oscillating voltage is applied to the model, by use of pulse current method to detect partial discharge signals. In order to study the statistical characteristics of partial discharge of cable joint under the oscillating voltage, three-dimensional statistical map has been made. The results show that for the same kind of defects, with the increases of the defect severity, the discharge interval extended, the magnitude and the number of partial discharge increase, for different kinds of defects, obvious differences exist among the maps, this may established a foundation for the further study of the partial discharge pattern recognition of XLPE cable under oscillating voltage.
文摘大语言模型(Large Language Model, LLM),尤其是一些预训练的深度神经网络,拥有强大的表征学习能力,不仅能学习典型的软件缺陷,还能够深度分析软件隐含的缺陷,给出风险提示和改进建议。大模型的应用,使得测试方法和流程更加智能化,且能够发现之前难以捕捉的复杂缺陷。航天器软件以其独特性、专业性、复杂性、高可靠性、高安全性的特点,需要通过专业的方法训练专业的大模型来满足航天嵌入式软件测试的需要。研究表明,大模型结合有效的测试方法形成的完备思维链(Chain of Thought, Cot)可以有效提高软件缺陷检出率。将测试专家的思维和大模型相结合,用专家思维链引导大模型查找软件缺陷,在提示词中增加测试专家的思维链可以有效提升软件缺陷检出效率,保证软件质量,显著提升测试团队的整体专业水平。
文摘Despite the fact that a number of approaches have been proposed for effective and accurate prediction of software defects, yet most of these have not found widespread applicability. Our objective in this communication is to provide a framework which is expected to be more effective and acceptable for predicting the defects in multiple phases across software development lifecycle. The proposed framework is based on the use of neural networks for predicting defects in software development life cycle. Further, in order to facilitate the easy use of the framework by project managers, a software graphical user interface has been developed that allows input data (including effort and defect) to be fed easily for predicting defects. The proposed framework provides a probabilistic defect prediction approach where instead of a definite number, a defect range (minimum, maximum, and mean) is predicted. The claim of efficacy and superiority of proposed framework is established through results of a comparative study, involving the proposed frame-work and some well-known models for software defect prediction.
文摘In current critical area models, it is generally assumed the defect outlines are circular and the conductors to be rectangle or the merger of rectangles. However, real defects and conductors associated with optimal layout design exhibit a great variety of shapes. Based on mathematical morphology, a new critical area model is presented, which can be used to estimate the critical area of short circuit, open circuit and pinhole. Based on the new model, the efficient validity check algorithms are explored to extract critical areas of short circuit, open circuit and pinhole from layouts. The results of experiment on an approximate layout of 4 × 4 shifts register show that the new model predicts the critical areas accurately. These results suggest that the proposed model and algorithm could provide new approaches for yield prediction.
文摘背景:H型血管因其独特的功能为深入理解血管介导的骨代谢调控机制提供了新的视角和切入点。目的:探讨H型血管在不同骨骼疾病动物模型中的生成机制及对骨代谢的影响。方法:系统检索CNKI、维普、万方、PubMed、Scopus和Web of Science数据库中2014年1月至2025年2月收录的H型血管相关中英文文献。剔除重复及不符合纳入标准的文献,对141篇涉及不同骨骼疾病动物模型中H型血管生成的文献进行系统分析。结果与结论:研究表明,H型血管在不同的骨骼疾病模型中表现出特定的生成机制和生物学功能。H型血管不仅在骨内血管生成中发挥重要作用,还与骨代谢密切相关,能够作为评估骨量水平的早期标志物。不同骨骼疾病动物模型中H型血管生成及作用不尽相同。在骨质疏松症、骨折、骨坏死等骨骼疾病中,通过促进H型血管表达,可显著改善血管重塑与骨再生能力;而在骨关节炎、骨肿瘤等恶性骨骼疾病中,选择性抑制H型血管表达则成为潜在的治疗干预策略。研究还揭示了多条关键信号通路在H型血管生成中的重要作用,如缺氧诱导因子1α/血管内皮生长因子、血小板源性生长因子BB、Wnt/β-catenin等,为理解血管介导的骨代谢调控机制提供了新的科学视角,同时为H型血管作为潜在治疗靶点的临床应用价值提供了重要理论基础。通过分析不同骨骼疾病动物模型中H型血管生成的作用,将为进一步深入探究人类骨关节疾病机制及治疗靶点提供重要依据。
