Trusted Hart for Mobile RISC-V Security

The majority of mobile devices today are based on Arm architecture that supports the hosting of trusted applications in Trusted Execution Environment (TEE). RISC-V is a relatively new open-source instruction set architecture that was engineered to fit many uses. In one potential RISC-V usage scenario, mobile devices could be based on RISC-V hardware. We consider the implications of porting the mobile security stack on top of a RISC-V system on a chip, identify the gaps in the open-source Keystone framework for building custom TEEs, and propose a security architecture that, among other things, supports the GlobalPlatform TEE API specification for trusted applications. In addition to Keystone enclaves the architecture includes a Trusted Hart -- a normal core that runs a trusted operating system and is dedicated for security functions, like control of the device's keystore and the management of secure peripherals. The proposed security architecture for RISC-V platform is verified experimentally using the HiFive Unleashed RISC-V development board.Comment: This is an extended version of a paper that has been published in Proceedings of TrustCom 202

Effect of Surfactants with Different Hydrophilic–Lipophilic Balance on the Cohesive Force between Cyclopentane Hydrate Particles

Effective control of the cohesive force between hydrate particles is the key to prevent their aggregation, which then causes pipeline blockage. The hydrophilic–lipophilic balance (HLB) value of surfactants was proposed as an important parameter for the evaluation and design of hydrate anti-agglomerants. A microscopic manipulation method was used to measure the cohesive forces between cyclopentane hydrate particles in the presence of Tween and Span series surfactants with different HLB values; moreover, the measured cohesive force was compared with the results of calculations based on the liquid bridge force model. Combined with the surface morphology and wettability of the hydrate particles, we analyzed the mechanism by which surfactants with different HLB values influence the cohesion between hydrate particles. The results show that for both Tween (hydrophilic, HLB > 10) and Span (hydrophobic, HLB < 10) surfactants, the cohesive force between cyclopentane hydrate particles decreased with decreasing HLB. The experimental results were in good agreement with the results of calculations based on the liquid bridge force model. The cohesive force between hydrate particles increased with increasing concentration of Tween surfactants, while in the case of the Span series, the cohesive force decreased with increasing surfactant concentration. In the formation process of cyclopentane hydrate particles, the aggregation of low-HLB surfactant molecules at the oil–water or gas–water interface increases the surface roughness and hydrophobicity of the hydrate particles and inhibits the formation of liquid bridges between particles, thus reducing the cohesion between particles. Therefore, the hydrate aggregation and the associated blockage risks can be reduced

A Meta Reinforcement Learning-Based Task Offloading Strategy for IoT Devices in an Edge Cloud Computing Environment

Developing an effective task offloading strategy has been a focus of research to improve the task processing speed of IoT devices in recent years. Some of the reinforcement learning-based policies can improve the dependence of heuristic algorithms on models through continuous interactive exploration of the edge environment; however, when the environment changes, such reinforcement learning algorithms cannot adapt to the environment and need to spend time on retraining. This paper proposes an adaptive task offloading strategy based on meta reinforcement learning with task latency and device energy consumption as optimization targets to overcome this challenge. An edge system model with a wireless charging module is developed to improve the ability of IoT devices to provide service constantly. A Seq2Seq-based neural network is built as a task strategy network to solve the problem of difficult network training due to different dimensions of task sequences. A first-order approximation method is proposed to accelerate the calculation of the Seq2Seq network meta-strategy training, which involves quadratic gradients. The experimental results show that, compared with existing methods, the algorithm in this paper has better performance in different tasks and network environments, can effectively reduce the task processing delay and device energy consumption, and can quickly adapt to new environments

Preparation of anti-tumor nanoparticle and its inhibition to peritoneal dissemination of colon cancer.

BACKGROUND: 5-Fluorouracil (5-FU) is one of the most classic chemotherapy drugs. Nanoparticle drug delivery vehicles offer superiority over target effect enhancement and abatement of side effects. Little is known however as to the specific effect of nanoparticle on peritoneal dissemination of colon cancer. The aim of this study is to prepare one NPs (nanoparticles) loaded with 5-FU and investigate the characteristic of NPs and the role of it in peritoneal metastasis nodules formation of human colon cancer. METHODOLOGY/PRINCIPAL FINDINGS: Prepared the NPs (nanoparticles) loaded with 5-FU (5-Fluorouracil) by PEG-PLGA with the method of double emulsion. Then evaluate the characteristics of the NPs by scanning electron microscopy, analyzing the particle diameter distribution and determining the loading efficiency. Detect the release features of NPs in vitro and in vivo. Nude mice with peritoneal metastases were treated with 5-FU solution or 5-FU-NPs through peritoneal cavity. Count the nodules on peritoneum and mesenterium and survey the size of them. We got NPs with average-diameter of 310 nm. In vitro release test shows NPs can release equably for 5 days with release rate of 99.2%. In vivo, NPs group can keep higher plasma concentration of 5-FU longer than it in solution group. The number of peritoneal dissemination nodule below 1 mm in 5-FU-sol group(17.3 ± 3.5) and 5-FU-NP group(15.2 ± 3.2) is less than control group(27.2 ± 4.7)(P<0.05). The total number of nodules in 5-FU-NP group(28.7 ± 4.2) is significantly smaller than in 5-FU-sol group(37.7 ± 6.3) (P<0.05). CONCLUSIONS/SIGNIFICANCE: The novel anti-tumor nanoparticles loaded with 5-FU by PEG-PLGA can release maintain 5 days and have inhibitory action to peritoneal dissemination of colon cancer in mice

Summary of the clinicopathologic features of ulcerative colitis, adenoma and carcinoma patients.

<p>Summary of the clinicopathologic features of ulcerative colitis, adenoma and carcinoma patients.</p

Correlation between Notch1 expression and clinicopathological features in patients with colorectal cancer.

<p>LNM, Lymph node metastasis; TNM, tumor node metastasis.</p