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Development of a computed tomography-based radiomics nomogram for prediction of transarterial chemoembolization refractoriness in hepatocellular carcinoma

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World Journal of Gastroenterology 2021年第2期27卷 189-207页

作者： Xiang-ke niu Xiao-Feng He Department of Interventional Radiology Nanfang HospitalSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina Department of Interventional Radiology Affiliated Hospital of Chengdu UniversityChengdu 610081Sichuan ProvinceChina

BACKGROUND Some patients with hepatocellular carcinoma(HCC)are more likely to experience disease progression despite continuous transarterial chemoembolization(TACE),which is called TACE *** present,it is still difficult to predict TACE refractoriness,although some models/scoring systems have been *** present,radiological-based radiomics models have been successfully applied to predict cancer patient *** To develop and validate a computed tomography(CT)-based radiomics nomogram for the pre-treatment prediction of TACE *** This retrospective study consisted of a training dataset(n=137)and an external validation dataset(n=81)of patients with clinically/pathologically confirmed HCC who underwent repeated TACE from March 2009 to March *** features were retrospectively extracted from preoperative CT images of the arterial *** pre-treatment radiomics signature was generated using least absolute shrinkage and selection operator Cox regression analysis.A CT-based radiomics nomogram incorporating clinical risk factors and the radiomics signature was built and verified by calibration curve and decision curve *** usefulness of the CT-based radiomics nomogram was assessed by Kaplan-Meier curve *** used the concordance index to conduct head-to-head comparisons of the radiomics nomogram with the other four models(Assessment for Retreatment with Transarterial Chemoembolization score;α-fetoprotein,Barcelona Clinic Liver Cancer,Child-Pugh,and Response score;CT-based radiomics signature;and clinical model).All analyses were conducted according to the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis *** The median duration of follow-up was 61.3 mo(interquartile range,25.5-69.3 mo)for the training cohort and 67.1 mo(interquartile range,32.4-71.3 mo)for the validation *** median number of TACE sessions was 4(range,3-7)in both cohorts.E

关键词： Hepatocellular carcinoma Transarterial chemoembolization Refractoriness Radiomics Nomogram Computed tomography

A Dual Domain Robust Reversible Watermarking Algorithm for Frame Grouping Videos Using Scene Smoothness

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Computers, Materials & Continua 2024年第6期79卷 5143-5174页

作者： Yucheng Liang ke niu Yingnan Zhang Yifei Meng College of Cryptographic Engineering Engineering University of the Chinese People’s Armed Police ForceXi’an710086China key Laboratory of Information Security of the Chinese People’s Armed Police Force Engineering University of the Chinese People’s Armed Police ForceXi’an710086China

The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grouping *** in the H.264 video coding standard,the algorithm first employs traditional robust watermark stitching technology to embed watermark information in the low-frequency coefficient domain of the U ***,it utilizes histogram migration techniques in the high-frequency coefficient domain of the U channel to embed auxiliary information,enabling successful watermark extraction and lossless recovery of the original video *** results demonstrate the algorithm’s strong imperceptibility,with each embedded frame in the experimental videos achieving a mean peak signal-to-noise ratio of 49.3830 dB and a mean structural similarity of *** with the three comparison algorithms,the performance of the two experimental indexes is improved by 7.59%and 0.4%on *** the same time,the proposed algorithm has strong robustness to both offline and online attacks:In the face of offline attacks,the average normalized correlation coefficient between the extracted watermark and the original watermark is 0.9989,and the average bit error rate is *** the face of online attacks,the normalized correlation coefficient between the extracted watermark and the original watermark is 0.8840,and the mean bit error rate is *** with the three comparison algorithms,the performance of the two experimental indexes is improved by 1.27%and 18.16%on average,highlighting the algorithm’s ***,the algorithm exhibits low computational complexity,with the mean encoding and the mean decoding time differentials during experimental video processing being 3.934 and 2.273 s,respectively,underscoring its practical utility.

关键词： Robust reversible watermarking scene smoothness dual-domain U channel H.264 encoding standard

A MV-Based Steganographic Algorithm for H.264/AVC without Distortion

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Computers, Materials & Continua 2020年第6期63卷 1205-1219页

作者： Hongqiong Tang Xiaoyuan Yang Yingnan Zhang ke niu Engineering University of PAP Xi’an710086China key Laboratory of Network and Information Security under the PAP Xi’an710086China

H.264/AVC video is one of the most popular multimedia and has been widely used as the carriers of video *** this paper,a novel motion vector(MV)based steganographic algorithm is proposed for the H.264/AVC compressed video without *** modules are introduced to eliminate the distortion caused by the modifications of motion vectors and guarantee the security of the *** the embedding block,the motion vector space encoding is used to embed a(2n+1)-ary notational number into an n-dimension vector composed of motion vectors generated from the selection *** is adopted to disturb the order of steganographic carriers to improve the randomness of the carrier before the operation of *** re-motion compensation(re-MC)block will re-construct the macroblock(MB)whose motion vectors have been modified by embedding *** block plays the role of the generator for chaotic sequences and encryptor for secret *** results demonstrate that our proposed algorithm can achieve high embedding capacity without stego video visual quality distortion,it also presents good undetectability for existing MV-based steganalysis *** comparisons with other existing algorithms are provided to demonstrate the superiority of the proposed algorithm.

关键词： Video steganography motion vector without distortion H.264/AVC

A HEVC Video Steganalysis Method Using the Optimality of Motion Vector Prediction

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Computers, Materials & Continua 2024年第5期79卷 2085-2103页

作者： Jun Li Minqing Zhang ke niu Yingnan Zhang Xiaoyuan Yang College of Cryptography Engineering Engineering University of the Chinese People’s Armed Police ForceXi’an710086China key Laboratory of Network and Information Security of the Chinese People’s Armed Police Force Xi’an710086China

Among steganalysis techniques,detection against MV(motion vector)domain-based video steganography in the HEVC(High Efficiency Video Coding)standard remains a challenging *** the purpose of improving the detection performance,this paper proposes a steganalysis method that can perfectly detectMV-based steganography in ***,we define the local optimality of MVP(Motion Vector Prediction)based on the technology of AMVP(Advanced Motion Vector Prediction).Secondly,we analyze that in HEVC video,message embedding either usingMVP index orMVD(Motion Vector Difference)may destroy the above optimality of *** then,we define the optimal rate of MVP as a steganalysis ***,we conduct steganalysis detection experiments on two general datasets for three popular steganographymethods and compare the performance with four state-ofthe-art steganalysis *** experimental results demonstrate the effectiveness of the proposed feature ***,our method stands out for its practical applicability,requiring no model training and exhibiting low computational complexity,making it a viable solution for real-world scenarios.

关键词： Video steganography video steganalysis motion vector prediction motion vector difference advanced motion vector prediction local optimality

Adaptive Video Dual Domain Watermarking Scheme Based on PHT Moment and Optimized Spread Transform Dither Modulation

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Computers, Materials & Continua 2024年第11期81卷 2457-2492页

作者： Yucheng Liang ke niu Yingnan Zhang Yifei Meng Fangmeng Hu College of Cryptographic Engineering Engineering University of the Chinese People’s Armed Police ForceXi’an710086China key Laboratory of Information Security of the Chinese People’s Armed Police Force Engineering University of the Chinese People’s Armed Police ForceXi’an710086China

To address the challenges of video copyright protection and ensure the perfect recovery of original video,we propose a dual-domain watermarking scheme for digital video,inspired by Robust Reversible Watermarking(RRW)technology used in digital *** approach introduces a parameter optimization strategy that incre-mentally adjusts scheme parameters through attack simulation fitting,allowing for adaptive tuning of experimental *** this scheme,the low-frequency Polar Harmonic Transform(PHT)moment is utilized as the embedding domain for robust watermarking,enhancing stability against simulation attacks while implementing the parameter optimization *** extensive attack simulations across various digital videos,we identify the optimal low-frequency PHT moment using adaptive ***,the embedding parameters for robust watermarking are adaptively adjusted to maximize *** address computational efficiency and practical requirements,the unnormalized high-frequency PHT moment is selected as the embedding domain for reversible *** optimize the traditional single-stage extended transform dithering modulation(STDM)to facilitate multi-stage embedding in the dual-domain watermarking *** practice,the video embedded with a robust watermark serves as the candidate *** candidate video undergoes simulation according to the parameter optimization strategy to balance robustness and embedding capacity,with adaptive determination of embedding *** reversible watermarking is formed by combining errors and other information,utilizing recursive coding technology to ensure reversibility without *** analyses of multiple performance indicators demonstrate that our scheme exhibits strong robustness against Common Signal Processing(CSP)and Geometric Deformation(GD)attacks,outperforming other advanced video watermarking algorithms under similar conditions of invisibility,reversibility,and embed

关键词： Dual-domain H.264 group of pictures polar harmonic transform spread transform dither modulation

Computed tomography-based score model/nomogram for predicting technical and midterm outcomes in transjugular intrahepatic portosystemic shunt treatment for symptomatic portal cavernoma

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World Journal of Clinical Cases 2020年第5期8卷 887-899页

作者： Xiang-ke niu Sushant Kumar Das Hong-Lin Wu Yong Chen Department of Radiology Affiliated Hospital of Chengdu UniversityChengdu 610081Sichuan ProvinceChina Department of Radiology Affiliated Hospital of North Sichuan Medical CollegeNanchong 637000Sichuan ProvinceChina Department of Interventional Radiology Nanfang HospitalSouthern Medical UniversityGuangzhou 510515Guangdong ProvinceChina

BACKGROUND Transjugular intrahepatic portosystemic shunt(TIPS)may be technically difficult in patients with cavernous transformation of the portal vein(CTPV).Computed tomography(CT)is widely used for assessing the situation of the portal vein and its tributaries before TIPS,and an ultrasound-based Yerdel grading system has been developed,which is deemed useful for liver ***,we hypothesized that a CT-based CTPV scoring system could be useful for predicting technical and midterm outcomes in TIPS treatment for symptomatic portal *** To investigate the clinical significance of a CT-based score model/nomogram for predicting technical success and midterm outcome in TIPS treatment for symptomatic *** Patients with symptomatic CTPV who had undergone TIPS from January 2010 to June 2017 were retrospectively *** CTPV was graded with a score of 1-4 based on contrast-CT imaging findings of the diseased *** measures were technical success rate,stent patency rate,and midterm ***’s kappa statistic,the Kaplan-Meier and log-rank tests,and uni-and multivariable analyses were performed.A nomogram was constructed and verified by calibration and decision curve *** A total of 76 patients(45 men and 31 women;mean age,52.3±14.7 years)were enrolled in the *** inter-reader agreement(κ)of the CTPV score was *** was successfully placed in 78%of patients(59/76).The independent predictor of technical success was CTPV score(odds ratio[OR]=5.56,95%confidence interval[CI]:3.55-9.67,P=0.002).The independent predictors of primary TIPS patency were CTPV score and splenectomy(OR=9.22,95%CI:4.78-13.45,P=0.009;OR=4.67,95%CI:2.59-7.44,P=0.017).The survival rates differed significantly between the TIPS success and failure *** clinical nomogram was made up of patient age,model for end-stage liver disease score,and CTPV *** calibration curves and decision curve analysis verified the usefulness of the

关键词： Portosystemic shunt Transjugular intrahepatic Liver cirrhosis Portal hypertension Oesophageal and gastric varices Bleeding Shunt dysfunction

Corrosion of Iron and Four Commercial Steels in a Cl-Containing Oxidizing Atmosphere at 500-600℃

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Journal of Materials Science & Technology 2004年第2期20卷 213-216页

作者： ke ZHANG, Yan niu, Chaoliu ZENG and Weitao WUState key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China Lab. for Corrosion and Protection Inst. of Metal Res. Chinese Acad. of Sci. Shenyang 110016 China

The corrosion behaviors of Fe and four commercial steels with different Cr contents were investigated in an oxidizing atmosphere containing HCI at 500~600℃, which simulated the environment to which materials are usually exposed in waste incineration. All the test materials underwent an accelerated corrosion in this atmosphere and small amounts of chlorine could be detected at the metal/scale interface. The corrosion mechanism is discussed on the basis of thermodynamic considerations for the reactions between metals and mixed O-Cl gases.

关键词： Commercial steels High temperature Chlorination Waste incineration

冷战与美国的大战略、国家安全理念和国家构建

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国际政治研究 2021年第1期42卷 78-97,7页

作者：牛可北京大学历史学系

作为政策思想和行为的"大战略"或者"国家战略"反映现代世界的总体战和"总体冷战"的特性和要求,具有内在的扩张性、综合性和政治性。大战略的关键意义既在于协调和统御军事和非军事因素,也在于平衡和整合政策和制度的对内和对外的方面。... 详细信息

作为政策思想和行为的"大战略"或者"国家战略"反映现代世界的总体战和"总体冷战"的特性和要求,具有内在的扩张性、综合性和政治性。大战略的关键意义既在于协调和统御军事和非军事因素,也在于平衡和整合政策和制度的对内和对外的方面。在冷战时期的美国,"国家安全"理念不仅是对外政策和战略的统御性理念,也连带着国内政府组织改造、国家扩张以及国家和社会的关系重建的重要内容。本文试图突显以往受到忽略的美国冷战大战略与国家建构的历史进程之间的关系,也提示美国冷战战略和政策的历史根源、国家风格和复杂多面的特征。

关键词：地区与国别政治冷战美国大战略国家安全国家构建

自由国际主义与第三世界——美国现代化理论兴起的历史透视

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美国研究 2007年第1期21卷 34-56页

作者：牛可北京大学历史学系

自由国际主义(liberal internationalism)是战后美国对外政策的基本"性格",它内在地要求生成美国主导的全球变迁的方案,特别是一个以援助和发展政策为核心的系统的第三世界政策,这是现代化理论运动在美国兴起的基本动力和历史条件。自... 详细信息

自由国际主义(liberal internationalism)是战后美国对外政策的基本"性格",它内在地要求生成美国主导的全球变迁的方案,特别是一个以援助和发展政策为核心的系统的第三世界政策,这是现代化理论运动在美国兴起的基本动力和历史条件。自由国际主义在冷战初期曾受到现实主义的有效抑制,一度延缓和削弱了美国对第三世界的重视及其对援助和发展政策的建构,现代化理论的政策效应即在于改变这种局面。现代化理论秉持自由国际主义并认同民主党自由主义,反映了美国自由主义演进的阶段性历史特征,又在很大程度上塑造了肯尼迪、约翰逊两届政府对第三世界的政策。

关键词：美国外交现代化理论自由国际主义第三世界援助和发展政策