IP address allocation protocols in vehicular ad hoc networks

In vehicular ad hoc networks (VANETs), communication takes place between vehicles to vehicles, the vehicles to the road side units, and vice-versa. The basic purpose of these communications is to share and exchange tremendous amount of data and information. For efficient information sharing, a systematic and structured connection establishment algorithm is needed. In VANETs, each connected node of the network need to be assigned a unique address. Hence, an algorithm is needed for the proper assignment of unique address to all nodes in the network. This paper explains different types of IP address protocols in VANETs. We have also explained advantage and disadvantage of existing IP address allocation protocols in VANETs.     

丙型肝炎治疗药物研发动态

丙型病毒性肝炎(viral hepatitis type C,HC),系丙型肝炎病毒(HCV)感染所引起的疾病,HCV感染影响着全世界近2亿人群,是引起慢性肝脏疾病的主要病因,进一步会引起肝硬化、肝癌和肝功能衰竭。本文主要介绍HCV及其结构、基于不同靶点的治疗丙肝的药物(标准方案、DAA药物、DAA药物联合标准方案、DAA药物相联合、其他药物联合、HCV疫苗等)的最新研发动态,并对目前的研发现状进行了展望。     

签名匿名性的研究

本文对代理签名、盲签名和群签名产生的背景以及它们可以实现的功能进行介绍,并且对它们的匿名性进行评价.最后分析了直接匿名证言方案的实现机制和它的匿名性.     

适用于超宽带的检测与避让测试平台

文章首先介绍了超宽带技术的特点,分析了目前超宽带工作环境中的干扰问题,引出了缓和干扰的检测与避让机制;接着对欧洲和中国的检测与避让机制的技术要求进行了说明;然后提出了验证检测与避让机制时的面临难点和挑战并给出了解决方案;最后介绍了两种检测与避让测试平台的设计和实现。     

Detection of interdependent primary systems using wideband cognitive radios

Cognitive radios (CRs) may be sharing multiple frequency bands with primary systems if the CR is a wideband or an ultra wideband (UWB) system. In that case, the CR should ensure all the coexisting primary systems in these bands are detected before it can start data transmission. In this work, we study the primary system detection performance of a wideband CR assuming that there are multiple coexisting primary systems and that these primary systems may be jointly active. Accordingly, we consider the implementation of energy detection scheme in multiple bands followed by two detection methods: (i) a maximum-a-posteriori (MAP) based detection (i.e., joint detection) that takes into account the statistics of simultaneously operating systems in independent bands and (ii) a Neyman–Pearson (NP) test based detection that optimizes the threshold values independently in each band (i.e., independent detection). For a simpler implementation of the independent detection, we show that the threshold values obtained from joint detection can be used in order to achieve the optimum NP test based independent detection results. In addition to quantifying the gain of joint detection over independent detection in terms of probabilities of false alarm and detection for practical scenarios, we also present the operation capability of CRs in terms of the fractions of time the CR can access the channel without interfering with the primary systems. The results are important for the practical implementation of multiband detection when the primary systems are known to be interdependent.     

Differential Expression of the Host Lipid Regulators ANGPTL-3 and ANGPTL-4 in HCV Infection and Treatment

Host lipid metabolism reprogramming is essential for hepatitis C virus (HCV) infection and progression to severe liver disease. Direct-acting antivirals (DAAs) achieve a sustained virological response (SVR) in most patients, but virus eradication does not always protect against hepatocellular carcinoma (HCC). Angiopoietin-like protein-3 (ANGPTL-3) and angiopoietin-like protein-4 (ANGPTL-4) regulate the clearance of plasma lipids by inhibiting cellular lipase activity and possess emerging roles in tumourigenesis. We used ELISA and RT-qPCR to investigate ANGPTL-3 and ANGPTL-4 expression in HCV patients with characterised fibrosis throughout the natural history of hepatitis C and in long-term HCV infection in vitro, before and after DAA treatment. ANGPTL-3 was decreased in patients with advanced fibrosis compared to other disease stages, while ANGPTL-4 was progressively increased from acute infection to cirrhosis and HCC, peaking at the advanced fibrosis stage. Only ANGPTL-3 mRNA was down-regulated during early infection in vitro, although both ANGPTLs were increased later. DAA treatment did not alter ANGPTL-3 levels in advanced fibrosis/cirrhosis and in HCV infection in vitro, in contrast to ANGPTL-4. The association between ANGPTLs and fibrosis in HCV infection was underlined by an inverse correlation between the levels of ANGPTLs and serum transforming growth factor- β (TGF-β). Collectively, we demonstrate the pivotal role of advanced fibrosis in defining the expression fate of ANGPTLs in HCV infection and after treatment and propose a role for ANGPTL-3 as a contributor to post-treatment deregulation of lipid metabolism that could predispose certain individuals to HCC development.     

Long term immunological perturbations post DAA therapy in chronic HCV/HIV co-infected patients

Direct-acting antiviral (DAA) therapies are efficacious for the achievement of sustained virologic response (SVR) in almost all treated hepatitis C virus (HCV)-infected patients. However, the impacts of HCV eradication on immune function and chronic immune activation in the long-term remain controversial and limited, especially in patients co-infected with human immunodeficiency virus (HIV). Indeed, although restoration of many immune responses clearly can be observed, several features of immune perturbations persist over time after HCV clearance. Understanding the degree and reasons of the partial recovery of the immune system in chronic HCV/HIV co-infection after HCV elimination is pivotal to avoid disease progression and possible long-term clinical outcomes in cured patients, as well as contributing to the development of immunotherapy drug design.     

基于DAA的可信双向匿名认证密钥协商协议

现有的匿名认证密钥协商协议,无法实现通信双方相互之间匿名认证,只能实现单向匿名认证,而某些应用场合往往需要实现双向匿名认证。为此,基于椭圆曲线密码学和双线性映射的DAA协议,在可信平台上设计了一个提供双向匿名认证的密钥协商协议,使通信双方能够相互验证对方具有某种成员关系,又不暴露各自的真实身份。该协议适合于计算和存储资源有限的应用场合。     

Hepatitis C in Special Patient Cohorts: New Opportunities in Decompensated Liver Cirrhosis,End-Stage Renal Disease and Transplant Medicine

Worldwide, hepatitis C virus (HCV) is a common infection. Due to new antiviral approaches and the approval of direct-acting antiviral agents (DAA), HCV therapy has become more comfortable. Nevertheless, there are special patient groups, in whom treatment of HCV is still challenging. Due to only few data available, tolerability and efficacy of DAAs in special patient cohorts still remain unclear. Such special patient cohorts comprise HCV in patients with decompensated liver disease (Child-Pugh Class B or C), patients with chronic kidney disease, and patients on waiting lists to renal/liver transplantation or those with HCV recurrence after liver transplantation. HCV infection in these patient cohorts has been shown to be associated with increased morbidity and mortality and may lead to reduced graft survival after transplantation. Successful eradication of HCV results in a better outcome concerning liver-related complications and in a better clinical outcome of these patients. In this review, we analyze available data and results from recently published literature and provide an overview of current recommendations of HCV-therapy regimen in these special patient cohorts.     

一种基于DAA的强匿名性门限签名方案

针对目前大多数门限签名方案不能实现签名成员匿名或匿名效果比弱的问题,该文提出了一种带有子密钥分发中心的强匿名性(n, t)门限签名方案。方案主要基于可信计算组织在其v1.2标准中采用的直接匿名认证(Direct Anonymous Attestation, DAA)方案,以及零知识证明和Feldman门限秘密共享等技术实现。相较已有方案,该方案即使在签名验证者和子密钥分发中心串通的情况下,也能够实现子签名的不可追踪性,也即可确保子签名成员的强匿名性。分析显示,方案除具有强匿名性外还具备签名子密钥不可伪造、子签名可验证以及一定的鲁棒性等特征。该方案在匿名表决等一些对匿名性要求较高的场合中有着重大的应用价值。