Photodynamic therapy(PDT)is a promising cancer therapy due to the evident advantages of a rapid curative eff ect,minimal or non-invasiveness,and circumvention of drug resistance.However,the hydrophobicity of photosens...Photodynamic therapy(PDT)is a promising cancer therapy due to the evident advantages of a rapid curative eff ect,minimal or non-invasiveness,and circumvention of drug resistance.However,the hydrophobicity of photosensitizers and the hypoxic tumor microenvironment in solid tumors reduce the therapeutic eff ect of PDT immensely.Herein,we construct a programmable hybrid mesoporous silica nanoparticle/DNA nanogel(H-DNA nanogel)for enhanced PDT.The H-DNA nanogel is constituted with a virus-like mesoporous silica nanoparticle(VMSN)as the core to provide an appropriate nano-interface and a self-assembly programmable DNA hydrogel layer based on rolling circle amplifi cation(RCA)as the shell.Two kinds of G-quadruplex structures inserted with a hemin and zinc phthalocyanine(ZnPc)photosensitizer are introduced into the H-DNA nanogel by base pairing.The two modules of G-quadruplex structure work as an oxygen supplement in the hypoxic tumor microenvironment and increase the yield of singlet oxygen,respectively.Our hybrid DNA nanogel system provides a modular platform for effi cient cancer PDT and has great potential in the broader biomedical fi eld.展开更多
The SRI analysis tool was used to comprehensively analyze the seven sets of chemistry questions in the 2021 college entrance examination paper from multiple dimensions such as exploratory test questions,various inquir...The SRI analysis tool was used to comprehensively analyze the seven sets of chemistry questions in the 2021 college entrance examination paper from multiple dimensions such as exploratory test questions,various inquiry standards and exploratory levels.The study found that all test papers involve the examination of scientific inquiry literacy;from the perspective of examination objectives,the 2021 college entrance examination questions as a whole focus on the examination of a single inquiry objective;the questions of each examination paper mainly examine three standards:design scheme,evidence processing and obtaining.The conclusion is drawn;the exploratory level of the chemistry questions in several sets of test papers is mostly a high level.展开更多
This article uses CiteSpace.5.8.R3c as a tool,analyzes 601 teaching paradigm research literatures from different perspectives such as author,research institution,keyword co-occurrence,clustering,highlighting and time ...This article uses CiteSpace.5.8.R3c as a tool,analyzes 601 teaching paradigm research literatures from different perspectives such as author,research institution,keyword co-occurrence,clustering,highlighting and time zone,and proposes recommendations based on the research results.展开更多
Visual tracking is a popular research area in com- puter vision, which is very difficult to actualize because of challenges such as changes in scale and illumination, rota- tion, fast motion, and occlusion. Consequent...Visual tracking is a popular research area in com- puter vision, which is very difficult to actualize because of challenges such as changes in scale and illumination, rota- tion, fast motion, and occlusion. Consequently, the focus in this research area is to make tracking algorithms adapt to these changes, so as to implement stable and accurate vi- sual tracking. This paper proposes a visual tracking algorithm that integrates the scale invariance of SURF feature with deep learning to enhance the tracking robustness when the size of the object to be tracked changes significantly. Particle filter is used for motion estimation. The co^fidence of each parti- cle is computed via a deep neural network, and the result of particle filter is verified and corrected by mean shift because of its computational efficiency and insensitivity to external interference. Both qualitative and quantitative evaluations on challenging benchmark sequences demonstrate that the pro- posed tracking algorithm performs favorably against several state-of-the-art methods throughout the challenging factors in visual tracking, especially for scale variation.展开更多
Keystroke-based behavioral biometrics have been proven effective for continuous user authentication.Current state-of-the-art algorithms have achieved outstanding results in long text or short text collected by doing s...Keystroke-based behavioral biometrics have been proven effective for continuous user authentication.Current state-of-the-art algorithms have achieved outstanding results in long text or short text collected by doing some tasks.It remains a considerable challenge to authenticate users continuously and accurately with short keystroke inputs collected in uncontrolled settings.In this work,we propose a Timely Keystroke-based method for Continuous user Authentication,named TKCA.It integrates the key name and two kinds of timing features through an embedding mechanism.And it captures the relationship between context keystrokes by the Bidirectional Long Short-Term Memory(Bi-LSTM)network.We conduct a series of experiments to validate it on a public dataset-the Clarkson II dataset collected in a completely uncontrolled and natural setting.Experiment results show that the proposed TKCA achieves state-of-the-art performance with 8.28%of EER when using only 30 keystrokes and 2.78%of EER when using 190 keystrokes.展开更多
基金supported by National Natural Science Foundation of China(Nos.21704074,21621004)Tianjin Natural Science Foundation(Basic Research Plan,Nos.18JCJQJC47600,19JCQNJC02200).
文摘Photodynamic therapy(PDT)is a promising cancer therapy due to the evident advantages of a rapid curative eff ect,minimal or non-invasiveness,and circumvention of drug resistance.However,the hydrophobicity of photosensitizers and the hypoxic tumor microenvironment in solid tumors reduce the therapeutic eff ect of PDT immensely.Herein,we construct a programmable hybrid mesoporous silica nanoparticle/DNA nanogel(H-DNA nanogel)for enhanced PDT.The H-DNA nanogel is constituted with a virus-like mesoporous silica nanoparticle(VMSN)as the core to provide an appropriate nano-interface and a self-assembly programmable DNA hydrogel layer based on rolling circle amplifi cation(RCA)as the shell.Two kinds of G-quadruplex structures inserted with a hemin and zinc phthalocyanine(ZnPc)photosensitizer are introduced into the H-DNA nanogel by base pairing.The two modules of G-quadruplex structure work as an oxygen supplement in the hypoxic tumor microenvironment and increase the yield of singlet oxygen,respectively.Our hybrid DNA nanogel system provides a modular platform for effi cient cancer PDT and has great potential in the broader biomedical fi eld.
文摘The SRI analysis tool was used to comprehensively analyze the seven sets of chemistry questions in the 2021 college entrance examination paper from multiple dimensions such as exploratory test questions,various inquiry standards and exploratory levels.The study found that all test papers involve the examination of scientific inquiry literacy;from the perspective of examination objectives,the 2021 college entrance examination questions as a whole focus on the examination of a single inquiry objective;the questions of each examination paper mainly examine three standards:design scheme,evidence processing and obtaining.The conclusion is drawn;the exploratory level of the chemistry questions in several sets of test papers is mostly a high level.
文摘This article uses CiteSpace.5.8.R3c as a tool,analyzes 601 teaching paradigm research literatures from different perspectives such as author,research institution,keyword co-occurrence,clustering,highlighting and time zone,and proposes recommendations based on the research results.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 61320106006, 61532006, 61502042）.
文摘Visual tracking is a popular research area in com- puter vision, which is very difficult to actualize because of challenges such as changes in scale and illumination, rota- tion, fast motion, and occlusion. Consequently, the focus in this research area is to make tracking algorithms adapt to these changes, so as to implement stable and accurate vi- sual tracking. This paper proposes a visual tracking algorithm that integrates the scale invariance of SURF feature with deep learning to enhance the tracking robustness when the size of the object to be tracked changes significantly. Particle filter is used for motion estimation. The co^fidence of each parti- cle is computed via a deep neural network, and the result of particle filter is verified and corrected by mean shift because of its computational efficiency and insensitivity to external interference. Both qualitative and quantitative evaluations on challenging benchmark sequences demonstrate that the pro- posed tracking algorithm performs favorably against several state-of-the-art methods throughout the challenging factors in visual tracking, especially for scale variation.
基金the National Key R&D Program of China(Grant No.2016YFB0801002).
文摘Keystroke-based behavioral biometrics have been proven effective for continuous user authentication.Current state-of-the-art algorithms have achieved outstanding results in long text or short text collected by doing some tasks.It remains a considerable challenge to authenticate users continuously and accurately with short keystroke inputs collected in uncontrolled settings.In this work,we propose a Timely Keystroke-based method for Continuous user Authentication,named TKCA.It integrates the key name and two kinds of timing features through an embedding mechanism.And it captures the relationship between context keystrokes by the Bidirectional Long Short-Term Memory(Bi-LSTM)network.We conduct a series of experiments to validate it on a public dataset-the Clarkson II dataset collected in a completely uncontrolled and natural setting.Experiment results show that the proposed TKCA achieves state-of-the-art performance with 8.28%of EER when using only 30 keystrokes and 2.78%of EER when using 190 keystrokes.
