Hyperglycemia-induced accumulation of advanced glycosylation end products in fibroblast-like synoviocytes promotes knee osteoarthritis

Li Qingxian,Wen Yinxian,Wang Linlong,Chen Biao,Chen Jun,Wang Hui,Chen Liaobin 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Osteoarthritis (OA) is significantly associated with diabetes, but how hyperglycemia induces or aggravates OA has not been shown. The synovium plays a critical role in cartilage metabolism and substance exchange. Herein, we intended to investigate whether and how hyperglycemia affects the occurrence and progression of OA by influencing the synovium. In patients with knee OA and diabetes (DM OA), we found a more severe inflammatory response, higher endoplasmic reticulum stress (ERS) levels, and more advanced glycosylation end products (AGEs) accumulation in the synovium than in patients without diabetes. Subsequently, we found similar results in the DM OA group in a rat model. In the in vitro cocultivation system, high glucose-stimulated AGEs accumulation, ERS, and inflammation in rat fibroblast-like synoviocytes (FLSs), which resulted in chondrocyte degeneration due to inflammatory factors from FLSs. Furthermore, in the synovium of the DM OA group and FLSs treated with high glucose, the expression of glucose transporter 1 (GLUT1) and its regulatory factor hypoxia-inducible factor (HIF)-1α was increased significantly. Inhibitors of HIF-1α, GLUT1 or AGEs receptors attenuated the effect of high glucose on chondrocyte degradation in the FLS-chondrocyte coculture system. In summary, we demonstrated that hyperglycemia caused AGEs accumulation in FLSs via the HIF-1α-GLUT1 pathway, which increases the release of inflammatory factors from FLSs, subsequently inducing chondrocyte degradation and promoting OA progression.

EPfuzzer: Improving Hybrid Fuzzing with Hardest-to-reach Branch Prioritization

( Yunchao Wang ),( Zehui Wu Qiang Wei ),( Qingxian Wang ) 한국인터넷정보학회 2020 KSII Transactions on Internet and Information Syst Vol.14 No.9

Hybrid fuzzing which combines fuzzing and concolic execution, has proved its ability to achieve higher code coverage and therefore find more bugs. However, current hybrid fuzzers usually suffer from inefficiency and poor scalability when applied to complex, real-world program testing. We observed that the performance bottleneck is the inefficient cooperation between the fuzzer and concolic executor and the slow symbolic emulation. In this paper, we propose a novel solution named EPfuzzer to improve hybrid fuzzing. EPfuzzer implements two key ideas: 1) only the hardest-to-reach branch will be prioritized for concolic execution to avoid generating uninteresting inputs; and 2) only input bytes relevant to the target branch to be flipped will be symbolized to reduce the overhead of the symbolic emulation. With these optimizations, EPfuzzer can be efficiently targeted to the hardest-to-reach branch. We evaluated EPfuzzer with three sets of programs: five real-world applications and two popular benchmarks (LAVA-M and the Google Fuzzer Test Suite). The evaluation results showed that EPfuzzer was much more efficient and scalable than the state-of-the-art concolic execution engine (QSYM). EPfuzzer was able to find more bugs and achieve better code coverage. In addition, we discovered seven previously unknown security bugs in five real-world programs and reported them to the vendors.

Distributed Coordination of Heterogeneous Multi-agent Systems with Dynamic Quantization and L2-L∞ Control

Shixun Xiong,Qingxian Wu,Yu-Hui Wang 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.10

This paper studies the dynamic output feedback consensus control problem of linear heterogeneous multi-agent systems under the leader-follower formation with a dynamic quantizer. In the practical engineering, the status information of the unmanned aircraft vehicle (UAV) and the unmanned underground vehicle (UGV) is normally unmeasurable, which is difficult to design the state feedback controller for the UAV-UGV formation. Besides, in the communication topology of the leader-follower formation based on UAVs and UGVs, the signals should be quantized in each follower. However, the traditional static quantizer has a quantization error, which affects the formation stability. Therefore, the control objective is to guarantee the UAV-UGV formation tracking consensus while improving the precision of the quantization. First, the followers and leader systems are based on the discretetime model, and the output trajectory of the leader is time-varying. Then, a dynamic output feedback controller is provided with a dynamic quantizer to guarantee the tracking performance of the heterogeneous multi-agent systemswith a leader. The followers can asymptotically track the leader system with L2 − L∞ control gains by solving a set of linear matrix inequalities (LMIs). Finally, simulation results demonstrate the effectiveness of the designed control strategies.

Deduplication and Exploitability Determination of UAF Vulnerability Samples by Fast Clustering

( Jianshan Peng ),( Mi Zhang ),( Qingxian Wang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.10

Use-After-Free (UAF) is a common lethal form of software vulnerability. By using tools such as Web Browser Fuzzing, a large amount of samples containing UAF vulnerabilities can be generated. To evaluate the threat level of vulnerability or to patch the vulnerabilities, automatic deduplication and exploitability determination should be carried out for these samples. There are some problems existing in current methods, including inadequate pertinence, lack of depth and precision of analysis, high time cost, and low accuracy. In this paper, in terms of key dangling pointer and crash context, we analyze four properties of similar samples of UAF vulnerability, explore the method of extracting and calculate clustering eigenvalues from these samples, perform clustering by fast search and find of density peaks on a large number of vulnerability samples. Samples were divided into different UAF vulnerability categories according to the clustering results, and the exploitability of these UAF vulnerabilities was determined by observing the shape of class cluster. Experimental results showed that the approach was applicable to the deduplication and exploitability determination of a large amount of UAF vulnerability samples, with high accuracy and low performance cost.

Advanced Spectral-Ratio Radon Background Estimate in Airborne Gamma-Ray Spectrometry and Calibration Technology

Yi Gu,Heng Lu,Meng Wang,Liangquan Ge,Qingxian Zhang 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.76 No.5

This paper discusses an advanced spectral-ratio method that subtracts Compton scattering rays by using a Fast Fourier Transform rather than tripping ratios and establishes a new radon background estimation mathematical model. A ground model calibration technology and a non-radioactive calibration technology based on a multiple-step Monte Carlo simulation are proposed for determining the new calibration coefficients. Applying the new calibration coefficients by using the two calibration technologies, we can remove successfully from the U window. The relative standard deviation of the radon-corrected U window count between the two calibration technologies is less than 30% within the height of the airborne survey, and it is reduced as the height increases.

A Dynamic Defense Using Client Puzzle for Identity-Forgery Attack on the South-Bound of Software Defined Networks

( Zehui Wu ),( Qiang Wei ),( Kailei Ren ),( Qingxian Wang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.2

Software Defined Network (SDN) realizes management and control over the underlying forwarding device, along with acquisition and analysis of network topology and flow characters through south bridge protocol. Data path Identification (DPID) is the unique identity for managing the underlying device, so forged DPID can be used to attack the link of underlying forwarding devices, as well as carry out DoS over the upper-level controller. This paper proposes a dynamic defense method based on Client-Puzzle model, in which the controller achieves dynamic management over requests from forwarding devices through generating questions with multi-level difficulty. This method can rapidly reduce network load, and at the same time separate attack flow from legal flow, enabling the controller to provide continuous service for legal visit. We conduct experiments on open-source SDN controllers like Fluid and Ryu, the result of which verifies feasibility of this defense method. The experimental result also shows that when cost of controller and forwarding device increases by about 2%-5%, the cost of attacker`s CPU increases by near 90%, which greatly raises the attack difficulty for attackers.

An OpenFlow User-Switch Remapping Approach for DDoS Defense

( Qiang Wei ),( Zehui Wu ),( Kalei Ren ),( Qingxian Wang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.9

DDoS attacks have had a devastating effect on the Internet, which can cause millions of dollars of damage within hours or even minutes. In this paper we propose a practical dynamic defense approach that overcomes the shortage of static defense mechanisms. Our approach employs a group of SDN-based proxy switches to relay data flow between users and servers. By substituting backup proxy switches for attacked ones and reassigning suspect users onto the new proxy switches, innocent users are isolated and saved from malicious attackers through a sequence of remapping process. In order to improve the speed of attacker segregation, we have designed and implemented an efficient greedy algorithm which has been demonstrated to have little influence on legitimate traffic. Simulations, which were then performed with the open source controller Ryu, show that our approach is effective in alleviating DDoS attacks and quarantining the attackers by numerable remapping process. The simulations also demonstrate that our dynamic defense imposes little effect on legitimate users, and the overhead introduced by remapping procedure is acceptable.