45 research outputs found

    Containment of network worms via per-process rate-limiting

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    Network worms pose a serious threat to the Internet infrastructure as well as end-users. Various techniques have been proposed for de-tection of, and response against worms. A frequently-used and au-tomated response mechanism is to rate-limit outbound worm traffic while maintaining the operation of legitimate applications, offering a gentler alternative to the usual detect-and-block approach. How-ever, most rate-limiting schemes to date only focus on host-level network activities and impose a single threshold on the entire host, failing to (i) accommodate network-intensive applications and (ii) effectively contain network worms at the same time. To allevi-ate these limitations, we propose a per-process-based containment framework in each host that monitors the fine-grained runtime be-havior of each process and accordingly assigns the process a sus-picion level generated by a machine-learning algorithm. We have also developed a heuristic to optimally map each suspicion level to the rate-limiting threshold. The framework is shown to be effective in containing network worms and allowing the traffic of legitimate programs, achieving lower false-alarm rates

    Case Report: Fluoroless implantation of left branch bundle pacing in a pregnant patient

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    A pregnant patient had symptomatic atrial standstill and indications for pacing therapy with an expected high ventricular pacing ratio. With the consideration of potential pacing-induced cardiomyopathy in the future we conducted zero-fluoro left bundle branch pacing (zLBBP) implantation for heart failure prevention. An ex vivo 3D cardiac model (Medtronic, USA) was used preoperatively to simulate the zLBBP implantation to improve procedure safety and efficiency. Intraoperatively, the simulation steps were followed, and a combination of electroanatomic navigation systems (EANS) and intracardiac echocariography (ICE) were used to ensure that the procedure was performed efficiently and safely

    Total Bilirubin Level is Associated with the Risk of Left Atrial Appendage Thrombosis in Patients with Non-Valvular Atrial Fibrillation

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    Objectives: There are some evidence suggesting that total bilirubin (TBIL) appears to be associated with stroke in patients with nonvalvular atrial fibrillation (NVAF). The left atrial appendage (LAA) is the most common orgin of thrombus in patients with NVAF. The purpose of this study was to assess a possible relationship between plasma TBIL levels and LAA thrombus in NVAF patients. Methods: We retrospectively screened 459 consecutive hospitalized patients with NVAF at three AF centers, who underwent transesophageal echocardiography or cardiac CT. According to the examination results, the patients were divided into either the LAA thrombosis group (41 cases) or the no LAA thrombosis group (418 cases). Independent sample t test, Mann-Whitney U-test and chi-square test were used to compare and analyze the general clinical data of the two groups. Multivariate Logistic regression was used to analyze whether TBIL was a risk factor for LAA thrombosis in patients with NVAF. Pearson correlation analysis was used to explore the correlation between TBIL and other influencing factors. The predictive value of TBIL for LAA thrombosis in patients with NVAF was evaluated by ROC curve. Results: A total of 459 patients were enrolled in this study. Compared with the group without LAA thrombosis, the level of TBIL in LAA thrombosis group was significantly increased (21.34 ± 9.34 umol/L vs. 13.98 ± 4.25 umol/L, 'P' < 0.001). Multivariate logistic regression showed that TBIL level was a risk factor for LAA thrombosis ('OR', 1.229; 95% 'CI', 1.122~1.345; 'P' < 0.001). The AUC of the ROC curve is 0.801 (95% 'CI', 0.725~0.877; 'P' < 0.001). At 17.4 umol/L of TBIL, the patient may have LAA thrombosis (sensitivity 73.2%; specificity 82.1%). Conclusions: In patients with NVAF, TBIL level is positively associated with LAA thrombosis, and TBIL level may be an index reflecting LAA thrombosis

    Effects of Linpan nature therapy on health benefits in older women with and without hypertension

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    BackgroundNature therapy can significantly benefit the physiology and psychology of middle-aged and older people, but previous studies have focused on forest environments. The restoration potential of rural environments in urban fringe areas, which are more accessible to older people on a daily basis, has not been fully studied. This study assessed the effects of nature therapy on the physical and mental health of older women in a rural setting (locally known as Linpan) in the urban fringe area of Chengdu, China.MethodsWe recruited a total of 60 older women (65.3 ± 5.5 years old) living in cities for 3 days of nature therapy in the winter (30 subjects) and spring (30 subjects), including 20 hypertensive patients.ResultsThe results showed that the overall blood pressure, pulse and sleep dysfunction rating scores of the participants were significantly lower than the pretest levels, and the finger blood oxygen saturation, mid-day salivary alpha-amylase and cortisol were increased post-treatment. Increases in these biomarker indicates and increase in stress. There were significant differences in the changes in systolic blood pressure between the hypertension group (HTN) and the normal group (normal) (HTN decreased by 8.8%, normal decreased by 5.4%), salivary alpha-amylase content (HTN decreased by 0.3%, normal increased by 16.9%), and sleep dysfunction rating scores (HTN decreased by 59.6%, normal decreased by 54%). The decreases in systolic blood pressure and pulse in the winter group were higher than those in the spring group by 1.8 and 4.4%, respectively, while the increases in salivary alpha-amylase content and salivary cortisol content were lower than those in the spring group by 11.7 and 11.2%, respectively, and the decrease in sleep dysfunction rating scores was lower than that in the spring group by 7.1%.ConclusionOur study concluded that nature therapy based on various health activities in the Linpan has significant health effects on older women. It can regulate blood pressure and pulse in older women, relieve cardiovascular disease, improve sleep quality. Meanwhile, older women with high blood pressure experienced a more significant effect than the healthy group

    High-Temperature Tribological Behavior of the Ti-22Al-25Nb (at. %) Orthorhombic Alloy with Lamellar O Microstructures

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    Tribological behavior of the isothermally forged and heat-treated Ti-22Al-25Nb (at. %) orthorhombic alloy with lamellar O microstructures was investigated. The friction experiments using a tribometer (UMT-3 CETR) against Si3N4 and Al2O3 were conducted at the load of 10N from 20 to 750 &#176;C and a constant speed of 0.188 m/s. The experiment results indicated that for the friction pair of Al2O3, the coefficient of friction (COF) was decreased from 0.906&#8315;0.359, and for the friction pair of Si3N4, COF was decreased from 0.784&#8315;0.457 as the friction temperature increased from room temperature to 750 &#176;C. The wear rate of the alloy against Al2O3 is in the range of 2.63&#8315;8.15 &#215; 10&#8722;4 mm3N&#8722;1m&#8722;1, the wear rate against Si3N4 is in the range of 2.44&#8315;5.83 &#215; 10&#8722;4 mm3N&#8722;1m&#8722;1, respectively. The wear mechanisms of the alloy were changed from plastic deformation and ploughing at lower temperature (20&#8315;400 &#176;C) to adhesive wear and oxidative mechanism at higher temperature (600 and 750 &#176;C). The friction and wear behavior of the Al2O3 friction pair was comparable to that of the Si3N4 friction pair

    Metallothionein 3 attenuated the apoptosis of neurons in the CA1 region of the hippocampus in the senescence-accelerated mouse/PRONE8 (SAMP8)

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    OBJECTIVE: Metallothionein 3 (MT-3) has been shown to protect against apoptotic neuronal death in the brains of patients with Alzheimer's disease. Zinc is a potent inhibitor of caspase-3 and its deficiency was found to promote apoptosis. Here, we measured the zinc and copper content in the brains of senescence-accelerated mouse/PRONE8 (SAMP8) and sought to investigate the effect of MT-3 on the apoptosis of neurons in the hippocampal CA1 region of these mice. METHOD: The zinc and copper content in the brain samples of SAMP8 and normal control SAMR1 mice were determined using an atomic absorption spectrophotometer. The mice were administered intraperitoneally for four weeks with MT-3 or MT1 and thereafter apoptosis was measured using the TUNEL method and the expression of anti-apoptotic protein Bcl-2 and proapoptotic protein Bax was examined by immunohistochemistry. RESULTS: Compared with that in SMAR1 mice, the content of zinc in the brains of SAMP8 mice was significantly reduced (P<0.05). Moreover, significant levels of apoptosis of neurons were observed in the hippocampus of SAMP8 mice, which, compared with those in SMAR1 mice, also showed significantly lower levels of Bcl-2 and higher levels of Bax (P<0.05). MT-3 increased zinc concentration in the hippocampus of SAMP8 mice and also significantly decreased apoptosis in these neurons dose-dependently and increased the levels of Bcl-2 and decreased the levels of Bax. CONCLUSION: MT-3 could attenuate apoptotic neuron death in the hippocampus of SAMP8, suggesting that the protein may lessen the development of neurodegeneration

    Microstructural Evolution and Mechanical Properties of Graphene-Reinforced Ti-6Al-4V Composites Synthesized via Spark Plasma Sintering

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    Ti-6Al-4V alloy (TC4) with different concentrations of graphene nanoplatelets (GNPs) were fabricated by ball milling and spark plasma sintering (SPS). Microstructure characteristics of the composites were characterized by X-Ray Diffraction (XRD), Scanning electron microscopy (SEM), and Raman. Microhardness and the compressive mechanical properties were also investigated. Experimental results showed that in the process of SPS, most of the GNPs were still retained at high pressure and temperature, and a new phase of TiC was presented due to the in-situ reaction between TiC and GNPs. Also, the strength of the composites was depended on the concentration of GNPs in TC4 matrix. Consequently, the composite with 0.8 wt. % GNPs was increased 18% in microhardness. The maximum yield strength and ductility of the composite were increased by 22.2% and 43.2%, respectively. The strengthening mechanism of the composites was further discussed, and the Orowan strengthening mechanism was the main strengthening factor
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