438 research outputs found

    SANSCrypt: A Sporadic-Authentication-Based Sequential Logic Encryption Scheme

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    We propose SANSCrypt, a novel sequential logic encryption scheme to protect integrated circuits against reverse engineering. Previous sequential encryption methods focus on modifying the circuit state machine such that the correct functionality can be accessed by applying the correct key sequence only once. Considering the risk associated with one-time authentication, SANSCrypt adopts a new temporal dimension to logic encryption, by requiring the user to sporadically perform multiple authentications according to a protocol based on pseudo-random number generation. Analysis and validation results on a set of benchmark circuits show that SANSCrypt offers a substantial output corruptibility if the key sequences are applied incorrectly. Moreover, it exhibits an exponential resilience to existing attacks, including SAT-based attacks, while maintaining a reasonably low overhead.Comment: This paper has been accepted at the 28th IFIP/IEEE International Conference on Very Large Scale Integration (VLSI-SoC

    A deep complementary energy method for solid mechanics using minimum complementary energy principle

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    In recent years, the rapid advancement of deep learning has significantly impacted various fields, particularly in solving partial differential equations (PDEs) in solid mechanics, benefiting greatly from the remarkable approximation capabilities of neural networks. In solving PDEs, Physics-Informed Neural Networks (PINNs) and the Deep Energy Method (DEM) have garnered substantial attention. The principle of minimum potential energy and complementary energy are two important variational principles in solid mechanics. However,DEM is based on the principle of minimum potential energy, but it lacks the important form of minimum complementary energy. To bridge this gap, we propose the deep complementary energy method (DCEM) based on the principle of minimum complementary energy. The output function of DCEM is the stress function. We extend DCEM to DCEM-Plus (DCEM-P), adding terms that satisfy partial differential equations. Furthermore, we propose a deep complementary energy operator method (DCEM-O) by combining operator learning with physical equations. We train DCEM-O using existing high-fidelity numerical results and the complementary energy together. We present numerical results using the Prandtl and Airy stress functions and compare DCEM with existing PINNs and DEM when modeling representative mechanical problems. The results demonstrate that DCEM outperforms DEM in terms of stress accuracy and efficiency and has an advantage in dealing with complex displacement boundary conditions. DCEM-P and DCEM-O further enhance the accuracy and efficiency of DCEM. In summary, our proposed DCEM marks the first time that complementary energy is extended to the energy-based physics-informed neural network and provides an essential supplementary energy form to the DEM in solid mechanics, offering promising research prospects in computational mechanics.Comment: 58 pages, 30 figure

    Biological Activities of Chinese Propolis and Brazilian Propolis on Streptozotocin-Induced Type 1 Diabetes Mellitus in Rats

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    Propolis is a bee-collected natural product and has been proven to have various bioactivities. This study tested the effects of Chinese propolis and Brazilian propolis on streptozotocin-induced type 1 diabetes mellitus in Sprague-Dawley rats. The results showed that Chinese propolis and Brazilian propolis significantly inhibited body weight loss and blood glucose increase in diabetic rats. In addition, Chinese propolis-treated rats showed an 8.4% reduction of glycated hemoglobin levels compared with untreated diabetic rats. Measurement of blood lipid metabolism showed dyslipidemia in diabetic rats and Chinese propolis helped to reduce total cholesterol level by 16.6%. Moreover, oxidative stress in blood, liver and kidney was improved to various degrees by both Chinese propolis and Brazilian propolis. An apparent reduction in levels of alanine transaminase, aspartate transaminase, blood urea nitrogen and urine microalbuminuria-excretion rate demonstrated the beneficial effects of propolis in hepatorenal function. All these results suggested that Chinese propolis and Brazilian propolis can alleviate symptoms of diabetes mellitus in rats and these effects may partially be due to their antioxidant ability

    Fish consumption and CHD mortality: an updated meta-analysis of seventeen cohort studies

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    Objective Results of studies on fish consumption and CHD mortality are inconsistent. The present updated meta-analysis was conducted to investigate the up-to-date pooling effects. Design A random-effects model was used to pool the risk estimates. Generalized least-squares regression and restricted cubic splines were used to assess the possible dose–response relationship. Subgroup analyses were conducted to examine the sources of heterogeneity. Setting PubMed and ISI Web of Science databases up to September 2010 were searched and secondary referencing qualified for inclusion in the study. Subjects Seventeen cohorts with 315 812 participants and average follow-up period of 15·9 years were identified. Results Compared with the lowest fish intake (\u3c1 serving/month or 1–3 servings/month), the pooled relative risk (RR) of fish intake on CHD mortality was 0·84 (95 % CI 0·75, 0·95) for low fish intake (1 serving/week), 0·79 (95 % CI 0·67, 0·92) for moderate fish intake (2–4 servings/week) and 0·83 (95 % CI 0·68, 1·01) for high fish intake (\u3e5 servings/week). The dose–response analysis indicated that every 15 g/d increment of fish intake decreased the risk of CHD mortality by 6 % (RR = 0·94; 95 % CI 0·90, 0·98). The method of dietary assessment, gender and energy adjustment affected the results remarkably. Conclusions Our results indicate that either low (1 serving/week) or moderate fish consumption (2–4 servings/week) has a significantly beneficial effect on the prevention of CHD mortality. High fish consumption (\u3e5 servings/week) possesses only a marginally protective effect on CHD mortality, possibly due to the limited studies included in this group

    Cloning of a gene encoding glycosyltransferase from Pueraria lobata (Wild.) Ohwi and its expression in Pichia pastoris

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    The key enzyme of puerarin biosynthesis in Pueraria lobata (Willd.) Ohwi was unclear but may involve glycosylation. To investigate the regulation of puerarin biosynthesis, a putative UDP-dependent glycosyltransferase (UGT) gene, PlUGT1 was isolated from P. lobata root, which contained abundant puerarin. PlUGT1 encoded 480 deduced amino acid residues with a conserved UDP-glucose-binding domain, which has 61 to 84% similarity to homologues from other plant species. SDS polyacrylamide gel electrophoresis and western blotting results showed that, fusion protein migrated as a single protein band with a molecular weight of 55 kDa. A yeast expression vector pPICZA-PlUGT1 was constructed and was transformed into Pichia pastoris strain GS115. Several recombinants containing multi-copy expression cassettes were obtained on the zeocin-YPD plate and confirmed by southern dot blotting. The yield of PlUGT1 attained 0.05 g/l when recombinant cells were cultured at pH 5.5, 30°C and induced with 0.5% methanol for 72 h. The expression of PlUGT1 protein correlates positively with the copy numbers of PlUGT1 in transformed yeast cells. These results suggest that, the PlUGT1 protein can be expressed efficiently in the P. pastoris expression system and may supply a new economic and convenient way for the production of PlUGT1 protein.Keywords: Pueraria lobata (Willd.) Ohwi, glycosyltransferase, cloning, expression, Pichia pastori

    Stability of Uncertain Impulsive Stochastic Genetic Regulatory Networks with Time-Varying Delay in the Leakage Term

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    This paper is concerned with the stability problem for a class of uncertain impulsive stochastic genetic regulatory networks (UISGRNs) with time-varying delays both in the leakage term and in the regulator function. By constructing a suitable Lyapunov-Krasovskii functional which uses the information on the lower bound of the delay sufficiently, a delay-dependent stability criterion is derived for the proposed UISGRNs model by using the free-weighting matrices method and convex combination technique. The conditions obtained here are expressed in terms of LMIs whose feasibility can be checked easily by MATLAB LMI control toolbox. In addition, three numerical examples are given to justify the obtained stability results
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