39 research outputs found
Research on Personal Information Risk Assessment Model in Smart Cities
Personal information security plays fundamental and critical role in promotion of smart cities. By taking personal information, vulnerability and threat as basic elements for risk assessment, this article proposes a Markov method-based personal information security risk assessment model in smart cities with the core of threats (Li Hetian, 2007). Based on threat probability, threat consequence attribute and attribute value acquired through the Markov method, threat analysis, the multi-attribute decision-making theory and the expert grading method, this article calculates the objective threat indexes, which is then utilized for risk ranking, so as to provide scientific basis for formulating targeted personal information security risk management and control strategies
Visual quality assessment for super-resolved images: database and method
Image super-resolution (SR) has been an active re-search problem which has recently received renewed interest due to the introduction of new technologies such as deep learning. However, the lack of suitable criteria to evaluate the SR perfor-mance has hindered technology development. In this paper, we fill a gap in the literature by providing the first publicly available database as well as a new image quality assessment (IQA) method specifically designed for assessing the visual quality of su-per-resolved images (SRIs). In constructing the Quality Assess-ment Database for SRIs (QADS), we carefully selected 20 refer-ence images and created 980 SRIs using 21 image SR methods. Mean opinion score (MOS) for these SRIs are collected through 100 individuals participating a suitably designed psychovisual experiment. Extensive numerical and statistical analysis is per-formed to show that the MOS of QADS has excellent suitability and reliability. The psychovisual experiment has led to the dis-covery that, unlike distortions encountered in other IQA data-bases, artifacts of the SRIs degenerate the image structure as well as image texture. Moreover, the structural and textural degener-ations have distinctive perceptual properties. Based on these in-sights, we propose a novel method to assess the visual quality of SRIs by separately considering the structural and textural com-ponents of images. Observing that textural degenerations are mainly attributed to dissimilar texture or checkerboard artifacts, we propose to measure the changes of textural distributions. We also observe that structural degenerations appear as blurring and jaggies artifacts in SRIs and develop separate similarity measures for different types of structural degenerations. A new pooling mechanism is then used to fuse the different similarities together to give the final quality score for an SRI. Experiments conducted on the QADS demonstrate that our method significantly outper-forms classical as well as current state-of-the-art IQA methods
Differential Effects of Tautomycetin and Its Derivatives on Protein Phosphatase Inhibition, Immunosuppressive Function and Antitumor Activity
In the present work, we studied the structure-activity relationship (SAR) of tautomycetin (TMC) and its derivatives. Further, we demonstrated the correlation between the immunosuppressive fuction, anticancer activity and protein phosphatase type 1 (PP1) inhibition of TMC and its derivatives. We have prepared some TMC derivatives via combinatorial biosynthesis, isolation from fermentation broth or chemical degradation of TMC. We found that the immunosuppressive activity was correlated with anticancer activity for TMC and its analog compounds, indicating that TMC may home at the same targets for its immunosuppressive and anticancer activities. Interestingly, TMC-F1, TMC-D1 and TMC-D2 all retained significant, albeit reduced PP1 inhibitory activity compared to TMC. However, only TMC-D2 showed immunosuppressive and anticancer activities in studies carried out in cell lines. Moreover, TMC-Chain did not show any significant inhibitory activity towards PP1 but showed strong growth inhibitory effect. This observation implicates that the maleic anhydride moiety of TMC is critical for its phosphatase inhibitory activity whereas the C1-C18 moiety of TMC is essential for the inhibition of tumor cell proliferation. Furthermore, we measured in vivo phosphatase activities of PP1 in MCF-7 cell extracts treated with TMC and its related compounds, and the results indicate that the cytotoxicity of TMC doesn't correlate with its in vivo PP1 inhibition activity. Taken together, our study suggests that the immunosuppressive and anticancer activities of TMC are not due to the inhibition of PP1. Our results provide a novel insight for the elucidation of the underlying molecular mechanisms of TMC's important biological functions
Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study
Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe
Review of progresses on clinical applications of ion selective electrodes for electrolytic ion tests: from conventional ISEs to graphene-based ISEs
There exist several positively and negatively charged electrolytes or ions in human blood, urine, and other body fluids. Tests that measure the concentration of these ions in clinics are performed using a more affordable, portable, and disposable potentiometric sensing method with few sample volumes, which requires the use of ion-selective electrodes (ISEs) and reference electrodes. This review summarily descriptively presents progressive developments and applications of ion selective electrodes in medical laboratory electrolytic ion tests, from conventional ISEs, solid-contact ISEs, carbon nanotube based ISEs, to graphene-based ISEs
40Ar/39Ar geochronological study and the genesis of extraneous 40Ar in Yuka HP/UHP phengite, North Qaidam, NW China
Six phengites from a restrict area in the Yuka terrane of the north Qaidam high/ultrahigh pressure (HP/UHP) metamorphic belt were dated using the 40Ar/39Ar method by laser stepwise heating, in order to investigate their geochronological significances and decipher the genesis of extraneous 40Ar in phengite. New 40Ar/39Ar age results show that the extraneous 40Ar exists in UHP metamorphic rocks (eclogite and amphibolite) phengite but not in their country rocks (gneiss and schist) phengite. High-Si and Mg-rich phengites from eclogite and phengite-bearing amphibolite yield disturbed age spectra, anomalously old apparent ages and a large variation in total gas ages (708-534 Ma) and isochron ages (681-513 Ma), indicating the existence of heterogeneous extraneous 40Ar. In contrast, relative low-Si and Fe-rich phengites from granitic gneiss and schist yield flat age spectra and geologically significant plateau ages (454.4 Ma and 418.0 Ma). The data points constituting the age plateaux yield isochrons with concordantly intercept ages of 456.2±2.3 and 418.1±2.2 Ma, corresponding to initial 40Ar/36Ar ratios of 177.3±151.2 and 287.1±16.9, respectively, implying that there is no extraneous 40Ar inside the minerals. The plateau age of 454.4 Ma recorded by phengite from granitic gneiss is interpreted as the age of cooling through its retention temperature for argon (ca. 400°C), and responding to the time of the Yuka metamorphic rocks exhumed from upper-mantle depth to middle-lower crustal levels (ca. 10 km in depth) after deep subduction. In contrast, the plateau age of 418 Ma from the schist should correspond to a Later Silurian ductile shearing deformation event. Considering the protoliths characteristics of the eclogite and amphibolite, the extremely high p-T metamorphic condition and aqueous fluid shortage environment during eclogite formation, we would suggest that the extraneous 40Ar*(not produced by in situ radiogenic decay of 40K) in phengites from Yuka is a locally derived component from the protolith rather than from a late infiltrating fluid
40Ar/39Ar geochronological study and the genesis of extraneous 40Ar in Yuka HP/UHP phengite, North Qaidam, NW China
Six phengites from a restrict area in the Yuka terrane of the north Qaidam high/ultrahigh pressure (HP/UHP) metamorphic belt were dated using the 40Ar/39Ar method by laser stepwise heating, in order to investigate their geochronological significances and decipher the genesis of extraneous 40Ar in phengite. New 40Ar/39Ar age results show that the extraneous 40Ar exists in UHP metamorphic rocks (eclogite and amphibolite) phengite but not in their country rocks (gneiss and schist) phengite. High-Si and Mg-rich phengites from eclogite and phengite-bearing amphibolite yield disturbed age spectra, anomalously old apparent ages and a large variation in total gas ages (708-534 Ma) and isochron ages (681-513 Ma), indicating the existence of heterogeneous extraneous 40Ar. In contrast, relative low-Si and Fe-rich phengites from granitic gneiss and schist yield flat age spectra and geologically significant plateau ages (454.4 Ma and 418.0 Ma). The data points constituting the age plateaux yield isochrons with concordantly intercept ages of 456.2±2.3 and 418.1±2.2 Ma, corresponding to initial 40Ar/36Ar ratios of 177.3±151.2 and 287.1±16.9, respectively, implying that there is no extraneous 40Ar inside the minerals. The plateau age of 454.4 Ma recorded by phengite from granitic gneiss is interpreted as the age of cooling through its retention temperature for argon (ca. 400°C), and responding to the time of the Yuka metamorphic rocks exhumed from upper-mantle depth to middle-lower crustal levels (ca. 10 km in depth) after deep subduction. In contrast, the plateau age of 418 Ma from the schist should correspond to a Later Silurian ductile shearing deformation event. Considering the protoliths characteristics of the eclogite and amphibolite, the extremely high p-T metamorphic condition and aqueous fluid shortage environment during eclogite formation, we would suggest that the extraneous 40Ar*(not produced by in situ radiogenic decay of 40K) in phengites from Yuka is a locally derived component from the protolith rather than from a late infiltrating fluid