69 research outputs found

    Anonymous and Efficient Message Authentication Scheme for Smart Grid

    Get PDF
    Smart grid has emerged as the next-generation electricity grid with power flow optimization and high power quality. Smart grid technologies have attracted the attention of industry and academia in the last few years. However, the tradeoff between security and efficiency remains a challenge in the practical deployment of the smart grid. Most recently, Li et al. proposed a lightweight message authentication scheme with user anonymity and claimed that their scheme is provably secure. But we found that their scheme fails to achieve mutual authentication and mitigate some typical attacks (e.g., impersonation attack, denial of service attack) in the smart grid environment. To address these drawbacks, we present a new message authentication scheme with reasonable efficiency. Security and performance analysis results show that the proposed scheme can satisfy the security and lightweight requirements of practical implementations and deployments of the smart grid

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

    Get PDF
    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    A Novel High Performance Magnetic Gear with Auxiliary Silicon Steel Sheet

    No full text
    Magnetic gear is a transmission device with novel structure. It uses the principle of magnetic field modulation to transmit torque. In view of the magnetic leakage of the magnetic gear in the process of rotation and cannot be eliminated, a magnetic gear model with auxiliary silicon steel sheet is proposed. Based on the conventional magnetic gear structure, the silicon steel sheet is placed outside the permanent magnet of the outer rotor. The magnetization mode of the outer rotor permanent magnet is tangential magnetization, and the spoke structure is adopted, and the inner rotor PMs is surface mounted and magnetized in the radial magnetization. The improved model is simulated by finite element method under three-dimensional conditions, and the electromagnetic performances of the model are optimized. Compared with the conventional magnetic gear model, the improved model has good performance, which improves the transmission capacity of output torque and reduces torque ripple. It is a great significance to improve the performance of magnetic gear

    THE EFFECT OF NUMBER OF POLE PAIRS ON TORQUE RIPPLE OF MAGNETIC GEAR

    No full text

    The effects and safety of vasopressin receptor agonists in patients with septic shock: a meta-analysis and trial sequential analysis

    No full text
    Abstract Background The aim of this study was to evaluate the effects and safety of vasopressin receptor agonists in patients with septic shock. Methods PubMed, EMBASE, and Cochrane library were searched for randomized controlled trials evaluating the effects of vasopressin receptor agonists in septic shock patients. Two reviewers performed literature selection, data extraction, and quality evaluation independently. The primary outcome was mortality. And secondary outcomes included intensive care unit (ICU) length of stay, duration of mechanical ventilation, and incidence of adverse events. In addition, a trial sequential analysis (TSA) was performed. Results Twenty studies were eligible for meta-analysis. The results showed vasopressin receptor agonists use was associated with reduced mortality (relative risk (RR) 0.92; 95% confidence interval (CI) 0.84 to 0.99; I 2 = 0%). Nevertheless, they had no significant effects on ICU length of stay (mean deviation (MD) − 0.08, 95% CI, − 0.68 to 0.52, I 2 = 0%) and duration of mechanical ventilation (MD − 0.58, 95% CI − 1.47 to 0.31, I 2 = 57%). Additionally, there was no significant difference in total adverse events between two groups (RR 1.28, 95% CI 0.87 to 1.90, I 2 = 57%), but vasopressin receptor agonists administration could significantly increase the risk of digital ischemia (RR 4.85, 95% CI 2.81 to 8.39, I 2 = 26%). Finally, there was no statistical difference of cardiovascular events (RR 0.91, 95% CI 0.53 to 1.57, I 2 = 1%), arrhythmia (0.77, 95% CI 0.48 to 1.23, I 2 = 23%), mesenteric ischemia (0.83, 95% CI 0.44 to 1.55, I 2 = 0%), diarrhea (2.47, 95% CI 0.77 to 7.96, I 2 = 49%), cerebrovascular events (1.36, 95% CI 0.18 to 10.54, I 2 = 0%), and hyponatremia (1.47, 95% CI 0.84 to 2.55, I 2 = 0%) between two groups. Egger’s test showed there was no significant publication bias among studies (P = 0.36). Conclusions The use of vasopressin might result in reduced mortality in patients with septic shock. An increased risk of digital ischemia must be taken into account

    Characteristic Analysis of a New Structure Eccentric Harmonic Magnetic Gear

    No full text
    An eccentric harmonic magnetic gear (EHMG) is better suited for situations requiring larger transmission ratios than magnetic-field-modulated magnetic gears. In the meantime, to increase the torque density even further, a new structure for EHMGs is presented in this paper. The stator’s permanent magnets (PMs) are irregularly distributed, while the rotor’s PMs are applied to a fan-shaped structure. Moreover, a Halbach array is adopted in both the rotor and the stator. A two-dimensional finite element (FE) model of the proposed EHMG is developed, and the flux density distribution and torque of the EHMG are calculated and verified via FE analysis. When compared to a conventional EHMG, the presented model’s torque increases from 38.04 Nm to 50.41 Nm. In addition, for the sake of avoiding the oscillation and noise caused by resonance, a modal analysis of the proposed model is conducted and the consequences show that it has better antivibration properties. Finally, a prototype is made, a test bench is established, and the correctness and effectiveness of the proposed model are verified
    corecore