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( Shuming Qiu ),( Guosheng Xu ),( Haseeb Ahmad ),( Guoai Xu ),( Xinping Qiu ),( Hong Xu ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.2
With the rapid development of the Internet of Things, the problem of privacy protection has been paid great attention. Recently, Nikooghadam et al. pointed out that Kumari et al.’s protocol can neither resist off-line guessing attack nor preserve user anonymity. Moreover, the authors also proposed an authentication supportive session initial protocol, claiming to resist various vulnerability attacks. Unfortunately, this paper proves that the authentication protocols of Kumari et al. and Nikooghadam et al. have neither the ability to preserve perfect forward secrecy nor the ability to resist key-compromise impersonation attack. In order to remedy such flaws in their protocols, we design a lightweight authentication protocol using elliptic curve cryptography. By way of informal security analysis, it is shown that the proposed protocol can both resist a variety of attacks and provide more security. Afterward, it is also proved that the protocol is resistant against active and passive attacks under Dolev-Yao model by means of Burrows-Abadi-Needham logic (BAN-Logic), and fulfills mutual authentication using Automated Validation of Internet Security Protocols and Applications (AVISPA) software. Subsequently, we compare the protocol with the related scheme in terms of computational complexity and security. The comparative analytics witness that the proposed protocol is more suitable for practical application scenarios.
Chongli Xu,Yu Liu,Yuchen Gong,Xinping Duan,Xiaochun Tang,Mingjun Zhang,Daxin Pang,Liqing Yu,Hongwei Zhao,Hongsheng Ouyang 한국유전학회 2015 Genes & Genomics Vol.37 No.2
Although Niemann-Pick C1-Like 1 (NPC1L1)plays a key role in intestinal cholesterol absorption, regulatingcholesterol metabolism and maintaining cholesterolmetabolic homeostasis, the molecular mechanism ofNPC1L1 in lipid-metabolism disorders leading to liverdisease remains largely unknown. Previous studies haveshown that NPC1L1 is related with the development offatty liver. Therefore, we hypothesized that NPC1L1 playsan important role in lipid-metabolism disorders and liverdisease by affecting the transcription of certain genesinvolved in lipid synthesis. To further elucidate the functionof NPC1L1, especially in the liver, we used somaticcellnuclear transfer to establish transgenic pigs thatexpressed human NPC1L1 in their livers. We investigatedsuperoxide dismutase activities and the levels of free fattyacids and malondialdehyde, a biomarker of lipid peroxidation. Superoxide dismutase activities significantlydecreased, and free fatty acid and malondialdehyde levelssignificantly increased in the NPC1L1 transgenic pigs,indicating that the overexpression of NPC1L1 in the liverresulted in severe lipid peroxidation. Our findings suggestthat NPC1L1 plays an important role in lipid-metabolismdisorders and liver disease.
Carbon molecular sieves from soybean straw-based activated carbon for CO2/CH4 separation
Yuxian Xu,Xiaochuan Chen,Dan Wu,Yongjin Luo,Xinping Liu,Qingrong Qian,Liren Xiao,Qinghua Chen 한국탄소학회 2018 Carbon Letters Vol.25 No.-
Soybean straw (SS)-based activated carbon was employed as a precursor to prepare carbon molecular sieves (CMSs) via chemical vapor deposition (CVD) technique using methane as carbon source. Prior to the CVD process, SS was activated by 0.5 wt% ZnCl2, followed by a carbonization at 500°C for 1 h in N2 atmosphere. N2 (77 K) adsorption-desorption and CO2 (273 K) adsorption tests were carried out to analyze the pore structure of the prepared CMSs. The results show that increasing the deposition temperature, time or methane flow rate leads the decrease in N2 adsorption capacity, micropore volume and average pore diameter of CMSs. The adsorption selectivity coefficient of CO2/CH4 achieves as high as 20.8 over CMSs obtained under the methane flow rate of 30 mL min–1 at 800°C for 70 min. The study demonstrates the prepared CMSs are a candidate adsorbent for CO2/CH4 separation.
Su Tong,Zhang Zhe,Chen Yu,Wang Yun,Li Yumei,Xu Min,Wang Jian,Li Jing,Tian Xinping,Jin Zhengyu 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.4
Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Darkblood- HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.