59 research outputs found
A Watermark-Based in-Situ Access Control Model for Image Big Data
When large images are used for big data analysis, they impose new challenges in protecting image privacy. For example, a geographic image may consist of several sensitive areas or layers. When it is uploaded into servers, the image will be accessed by diverse subjects. Traditional access control methods regulate access privileges to a single image, and their access control strategies are stored in servers, which imposes two shortcomings: (1) fine-grained access control is not guaranteed for areas/layers in a single image that need to maintain secret for different roles; and (2) access control policies that are stored in servers suffers from multiple attacks (e.g., transferring attacks). In this paper, we propose a novel watermark-based access control model in which access control policies are associated with objects being accessed (called an in-situ model). The proposed model integrates access control policies as watermarks within images, without relying on the availability of servers or connecting networks. The access control for images is still maintained even though images are redistributed again to further subjects. Therefore, access control policies can be delivered together with the big data of images. Moreover, we propose a hierarchical key-role-area model for fine-grained encryption, especially for large size images such as geographic maps. The extensive analysis justifies the security and performance of the proposed model
Epigenetic hypomethylation and upregulation of GD3s in triple negative breast cancer.
Background: Breast cancer remains a major health problem in the world. Triple-negative breast cancer (TNBC) is an aggressive subtype with very poor prognosis. Up to now, the mechanism behind TNBC\u27s activity is still unclear and no candidate drug target has been identified. Thus, it is of critical importance to elucidate the pathways in TNBC and identify the relevant biomarkers. Recent studies showed that ganglioside D3 synthase (GD3s) played a very important role in development of cancers. However, the physiological functions and associated pathways of GD3s in TNBC are still unclear.
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Conclusions: In summary, these results suggest that GD3s may be a potential biomarker and drug target in treatment of TNBC
The BDNFVal66Met SNP modulates the association between beta-amyloid and hippocampal disconnection in Alzheimer’s disease
In Alzheimer’s disease (AD), a single-nucleotide polymorphism in the gene encoding brain-derived neurotrophic factor (BDNFVal66Met) is associated with worse impact of primary AD pathology (beta-amyloid, Aβ) on neurodegeneration and cognitive decline, rendering BDNFVal66Met an important modulating factor of cognitive impairment in AD. However, the effect of BDNFVal66Met on functional networks that may underlie cognitive impairment in AD is poorly understood. Using a cross-validation approach, we first explored in subjects with autosomal dominant AD (ADAD) from the Dominantly Inherited Alzheimer Network (DIAN) the effect of BDNFVal66Met on resting-state fMRI assessed functional networks. In seed-based connectivity analysis of six major large-scale networks, we found a stronger decrease of hippocampus (seed) to medial-frontal connectivity in the BDNFVal66Met carriers compared to BDNFVal homozogytes. BDNFVal66Met was not associated with connectivity in any other networks. Next, we tested whether the finding of more pronounced decrease in hippocampal-medial-frontal connectivity in BDNFVal66Met could be also found in elderly subjects with sporadically occurring Aβ, including a group with subjective cognitive decline (N = 149, FACEHBI study) and a group ranging from preclinical to AD dementia (N = 114, DELCODE study). In both of these independently recruited groups, BDNFVal66Met was associated with a stronger effect of more abnormal Aβ-levels (assessed by biofluid-assay or amyloid-PET) on hippocampal-medial-frontal connectivity decreases, controlled for hippocampus volume and other confounds. Lower hippocampal-medial-frontal connectivity was associated with lower global cognitive performance in the DIAN and DELCODE studies. Together these results suggest that BDNFVal66Met is selectively associated with a higher vulnerability of hippocampus-frontal connectivity to primary AD pathology, resulting in greater AD-related cognitive impairment
Vitamin D and cause-specific vascular disease and mortality:a Mendelian randomisation study involving 99,012 Chinese and 106,911 European adults
Numerical Investigation on Air Film Fusion of Pressure-Equalizing Exhaust around Shoulder Ventilation of Submarine-Launched Vehicle
In order to study the influence of pressure-equalizing exhaust at the shoulder of a submarine-launched vehicle on the surface hydrodynamic characteristics, this paper establishes a numerical calculation method based on the VOF multiphase flow model, the standard RNG turbulence model and the overset mesh technology; the method compares the fusion characteristics of the air film at the shoulder of the underwater vehicle, as well as the distribution of surface pressure along the vehicle’s axial direction. The results show that the approximate isobaric zone derived from air film fusion can greatly improve the hydrodynamic characteristics of the vehicle, and the number of venting holes determines the circumferential fusion time of the air film. The greater the number of venting holes, the sooner circumferential fusion starts
Numerical Investigation on Air Film Fusion of Pressure-Equalizing Exhaust around Shoulder Ventilation of Submarine-Launched Vehicle
In order to study the influence of pressure-equalizing exhaust at the shoulder of a submarine-launched vehicle on the surface hydrodynamic characteristics, this paper establishes a numerical calculation method based on the VOF multiphase flow model, the standard RNG turbulence model and the overset mesh technology; the method compares the fusion characteristics of the air film at the shoulder of the underwater vehicle, as well as the distribution of surface pressure along the vehicle’s axial direction. The results show that the approximate isobaric zone derived from air film fusion can greatly improve the hydrodynamic characteristics of the vehicle, and the number of venting holes determines the circumferential fusion time of the air film. The greater the number of venting holes, the sooner circumferential fusion starts
Experimental study on the cavitation flow and motion characteristics of the vehicle launched underwater
In this paper, an experimental system was independently designed to investigate the cavitation flow mechanism and motion characteristic of the vehicle launched underwater. Conducted experiments based on high-speed photography, and the influence of cavity morphological evolution and kinematic characteristics with the different launch and transverse velocities were analyzed. The results show that cavity shedding phenomenon occurs on different scales. Subsequently, a wide range of pressure impulse on the surface of the vehicle is caused by the collapse of large-scale cavity groups, resulting in an obvious sputtering phenomenon on its surface during the water-exit stage. The more the launch speed increases, the longer the initial cavity length is. Moreover, the moment of completely shedding the cavity delays during the water exit process; Furthermore, with the increase of transverse speed, the attitude angle generally shows an increasing trend, but its growth rate slowed down during the large-scale shedding stage of the cavity
Method and application of information sharing throughout the emergency rescue process based on 5G and AR wearable devices
Abstract The 2022 Winter Olympics were held in the three competition zones of Beijing, Yanqing and Zhangjiakou, China. The venues of this Winter Olympics were scattered and the terrain was complex. Moreover, the medical resources of Hebei and Beijing were relatively unbalanced. In the medical security of major events, the connection between first aid and in-hospital processes is of the utmost importance to rescue quality. 5th generation mobile network (5G) applications in medical scenarios are on the rise. It would be of great relevance to fully use 5G’s low-latency and high-speed features to share the process information of patients, ambulance personnel, and the destination hospital’s rescue team at emergency scenes and in transportation, improving rescue efficiency. This paper proposes a system scheme of cross-institutional emergency health information sharing based on 5G and augmented reality wearable devices. It also integrates the construction method of monitoring and other sign data sharing, in addition to testing the proposed scheme’s service quality in 5G environments. In the deployment area of the 5G emergency medical rescue information sharing scheme for the Beijing Winter Olympic Games, we selected two designated medical support institutions for testing. The test adopted a combination of fixed-point and driving tests to experiment on the service data, voice service, and streaming media indicators. The 5G signal's coverage rate was close to 100%, the standalone connection's success rate was 100%, and the drop rate was 0. The average downlink rate of multiple scenarios was 620mbps, and the average uplink rate of 5G was over 71.8mbps, which is higher than the average 5G level in China. The downlink rate was more than 20 times larger than the 4th generation mobile network (4G) rate. This study’s proposed scheme demonstrates the importance of 5G applications in emergency response and support, in addition to providing a suitable scheme for the integration of 5G networks in the medical scene
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