102 research outputs found

    Janus: An Uncertain Cache Architecture to Cope with Side Channel Attacks

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    Side channel attacks are a major class of attacks to crypto-systems. Attackers collect and analyze timing behavior, I/O data, or power consumption in these systems to undermine their effectiveness in protecting sensitive information. In this work, we propose a new cache architecture, called Janus, to enable crypto-systems to introduce randomization and uncertainty in their runtime timing behavior and power utilization profile. In the proposed cache architecture, each data block is equipped with an on-off flag to enable/disable the data block. The Janus architecture has two special instructions in its instruction set to support the on-off flag. Beside the analytical evaluation of the proposed cache architecture, we deploy it in an ARM-7 processor core to study its feasibility and practicality. Results show a significant variation in the timing behavior across all the benchmarks. The new secure processor architecture has minimal hardware overhead and significant improvement in protecting against power analysis and timing behavior attacks.Comment: 4 pages, 4 figure

    Design, Modeling and Optimization of a High-speed Permanent Magnet Synchronous Machine with Retention Sleeve of Rotor using Taguchi Optimization Method

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    This paper presents a novel method based on the well-known Taguchi optimization method to design and optimize a high-speed permanent magnet synchronous machine (HS-PMSM). An HS-PMSG is analytically designed at the first step, and next, it has been optimized by the Taguchi optimization method and verified through FEM analysis. Results obtained from the electromagnetic and mechanical simulations of HS-PMSG show that in the optimized design: Owing to the reduction in the thicknesses of the retention sleeve (48.05%) and PM (16.66%), as a consequence, the total size and dimensions of the HS-PMSG are reduced. The weight of PM and the retention sleeve are reduced by about 16.31% and 29.28% responsively, and as a result, the total weight of HS-PMSG is reduced by approximately 1.94%. The Joule loss is reduced by about 9.80%. The HS-PMSG efficiency is improved by 0.02%, and finally, the cogging torque is reduced by 22.44%, compared with the initially designed machine

    The Association of Chlamydia pneumonia and Helicobacter pylori IgG Seropositivity With Omentin-1, Visfatin and Adiponectin Levels in Postmenopausal Women.

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    Abstract Some adipocytokines are cardioprotective or pro-inflammatory for cardiovascular system. Chronic infection with Chlamydia pneumoniae and Helicobacter pylori has been also considered as novel risk factors for atherosclerosis. The main aim of the current population-based study is to investigate the potential link between circulating adipocytokines and Chlamydia pneumoniae or Helicobacter pylori IgG seropositivities. A total of 250 healthy postmenopausal women who participated in a prospective cohort study were evaluated for IgG antibodies directed against C.pneumoniae and H. pylori. Omentin-1, visfatin, adiponectin, and high sensitivity C-reactive protein were measured by highly specific enzyme-linked immunosorbent assay methods. The prevalence of IgG antibodies against C. pneumoniae and H. pylori among the studied population was 20.4% (51 women) and 57.2% (143 women), respectively. There were no significant differences in adipocytokine levels between H. pylori IgG seropositive and H. pylori seronegative subjects. Similar results for visfatin and omentin-1 were found when C. pneumoniae IgG seropositive were compared with C. pneumoniae IgG seronegative subjects. However, in general linear model adjusted for age, body mass index and hs-CRP levels revealed significant difference between C. pneumoniae seropositive and C. pneumoniae seronegative subjects for circulating adiponectin. In conclusion, Chlamydia pneumoniae IgG seropositivity was associated with higher adiponectin levels in postmenopausal women. The elucidation of interaction mechanism of Chlamydia pneumoniae and a cardioprotective adipocytokine (adiponectin) will be useful in future therapeutic strategies

    Chlamydia pneumoniae and Helicobacter pylori IgG seropositivities are not predictors of osteoporosis‑associated bone loss: a prospective cohort study

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    The potential link between infection with Chlamydia pneumoniae or Helicobacter pylori and osteoporosis has not been investigated in population-based longitudinal studies. A total of 250 healthy postmenopausal women who participated in a prospective cohort study were evaluated for IgG antibodies directed against C. pneumoniae and H. pylori, osteoprotegerin (OPG), the receptor activator of nuclear factor kappa B ligand (RANKL), CrossLaps, and osteocalcin. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine at baseline and at follow- up 5.8 years later. There were no significant differences in age-adjusted bone turnover markers, OPG, RANKL, the RANKL/OPG ratio, and BMD between the C. pneumoniae and H. pylori IgG seropositive and seronegative subjects (P > 0.05). Neither C. pneumoniae nor H. pylori IgG seropositivity was associated with age-and body mass index-adjusted BMD at the femoral neck and lumbar spine or bone loss at the 5.8-year follow-up. In logistic regression analysis, neither C. pneumoniae nor H. pylori IgG seropositivities predicted incident lumbar or spine osteoporosis 5.8 years later. In conclusion, neither C. pneumoniae nor H. pylori IgG seropositivity was associated with bone turnover markers, the RANKL/OPG ratio, BMD, or bone loss in postmenopausal women. In addition, chronic infection with C. pneumoniae or H. pylori did not predict incident osteoporosis among this group of women

    Minocycline through attenuation of oxidative stress and inflammatory response reduces the neuropathic pain in a rat model of chronic constriction injury

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    Objectives: Several lines of evidence showed that minocycline possesses antioxidant and anti-inflammatory properties. This study aimed to demonstrate the effects of minocycline in rats subjected to chronic constriction injury (CCI). Materials and Methods: In this study four groups (n = 6-8) of rats were used as follows: Sham, CCI, CCI + minocycline (MIN) 10 mg/Kg (IP) and CCI + MIN 30 mg/Kg (IP). On days 3, 7, 14, and 21 post-surgery hot-plate, acetone, and von Frey tests were carried out. Finally, Motor Nerve Conduction Velocity Evaluation (MNCV) assessment was performed and spinal cords were harvested in order to measure tissue concentrations of TNF_α, IL-1β, Glutathione peroxidase (GPx), Superoxide dismutase (SOD) and Malondialdehyde (MDA). Extent of perineural inflammation and damage around the sciatic nerve was histopathologically evaluated. Results: Our results demonstrated that CCI significantly caused hyperalgesia and allodynia twenty-one days after CCI. MIN attenuated heat hyperalgesia, cold and mechanical allodynia and MNCV in animals. MIN also decreased the levels of TNF_α and IL-1β. Antioxidative enzymes (SOD, MDA, and GPx) were restored following MIN treatment. Our findings showed that MIN decreased perineural inflammation around the sciatic nerve. According to the results, the neuropathic pain reduced in the CCI hyperalgesia model using 30 mg/kg of minocycline. Conclusion: It is suggested that antinociceptive effects of minocycline might be mediated through the inhibition of inflammatory response and attenuation of oxidative stress
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