Security and privacy aspects of mobile applications for post-surgical care

Mobile technologies have the potential to improve patient monitoring, medical decision making and in general the efficiency and quality of health delivery. They also pose new security and privacy challenges. The objectives of this work are to (i) Explore and define security and privacy requirements on the example of a post-surgical care application, and (ii) Develop and test a pilot implementation Post-Surgical Care Studies of surgical out- comes indicate that timely treatment of the most common complications in compliance with established post-surgical regiments greatly improve success rates. The goal of our pilot application is to enable physician to optimally synthesize and apply patient directed best medical practices to prevent post-operative complications in an individualized patient/procedure specific fashion. We propose a framework for a secure protocol to enable doctors to check most common complications for their patient during in-hospital post- surgical care. We also implemented our construction and cryptographic protocols as an iPhone application on the iOS using existing cryptographic services and libraries

Perfect Distance Stars mod m

A perfect distance tree is a weighted tree with n vertices in which the set of distances between vertices is . We define a tree with n vertices to be a Perfect Distance Tree mod m if the distances (mod m) can be obtained. In this paper, we find that every star with m+1 vertices, where m is odd, labeled with 0, 1, 2, 3, ..., m-1 is a perfect distance tree mod m. The stars obtained from this star by removing the edge labeled 0 or by changing the weight 0 to another weight are also perfect distance trees mod m. By combining stars, we show that every star with km+j vertices can be labeled to be a perfect distance tree mod m, where m is odd, k ≥ 1 and -1 ≤ j ≤ 4. Finally, we show that certain twin-stars (trees of diameter 3) can be labeled as perfect distance trees mod m

Privacy-preserving queries on encrypted databases

In today's Internet, with the advent of cloud computing, there is a natural desire for enterprises, organizations, and end users to outsource increasingly large amounts of data to a cloud provider. Therefore, ensuring security and privacy is becoming a significant challenge for cloud computing, especially for users with sensitive and valuable data. Recently, many efficient and scalable query processing methods over encrypted data have been proposed. Despite that, numerous challenges remain to be addressed due to the high complexity of many important queries on encrypted large-scale datasets. This thesis studies the problem of privacy-preserving database query processing on structured data (e.g., relational and graph databases). In particular, this thesis proposes several practical and provable secure structured encryption schemes that allow the data owner to encrypt data without losing the ability to query and retrieve it efficiently for authorized clients. This thesis includes two parts. The first part investigates graph encryption schemes. This thesis proposes a graph encryption scheme for approximate shortest distance queries. Such scheme allows the client to query the shortest distance between two nodes in an encrypted graph securely and efficiently. Moreover, this thesis also explores how the techniques can be applied to other graph queries. The second part of this thesis proposes secure top-k query processing schemes on encrypted relational databases. Furthermore, the thesis develops a scheme for the top-k join queries over multiple encrypted relations. Finally, this thesis demonstrates the practicality of the proposed encryption schemes by prototyping the encryption systems to perform queries on real-world encrypted datasets

In-situ growth of nitrogen-doped carbon nanotubes on MXene nanosheets for efficient sodium/potassium-ion storage

For game changing for future of large-scale energy storage technologies, sodium-ion and potassium-ion batteries provide a substitute to lithium-ion batteries. As an excellent candidate anode, MXene still suffers from the blockage of active sites caused by restacking of sheets. Herein, an in-situ decoration of MXene nanosheets with nitrogen-doped carbon nanotubes (CNTs) is introduced, to yield MXene@CNTs. The modification of nitrogen-doped CNTs not only prevents the restacking of MXene and increases ion accessibility but also improves the electrode’s overall conductivity, thereby enhancing electron conduction and ion diffusion kinetics significantly. Therefore, MXene@CNTs exhibits superior sodium/potassium-ion storage performance than pure MXene nanosheets. At 0.05 A g-1, it can deliver reversible capacities of 286 mAh g-1 for SIBs and 250 mAh g-1 for PIBs. This research illustrates the significance of the electrode architecture for electrochemical performances, and the in-situ growth strategy could provide some insight on searching for high-performance MXene-based anodes for SIBs and PIBs

Corin Deficiency Alters Adipose Tissue Phenotype and Impairs Thermogenesis in Mice

Atrial natriuretic peptide (ANP) is a key regulator in body fluid balance and cardiovascular biology. In addition to its role in enhancing natriuresis and vasodilation, ANP increases lipolysis and thermogenesis in adipose tissue. Corin is a protease responsible for ANP activation. It remains unknown if corin has a role in regulating adipose tissue function. Here, we examined adipose tissue morphology and function in corin knockout (KO) mice. We observed increased weights and cell sizes in white adipose tissue (WAT), decreased levels of uncoupling protein 1 (Ucp1), a brown adipocyte marker in WAT and brown adipose tissue (BAT), and suppressed thermogenic gene expression in BAT from corin KO mice. At regular room temperature, corin KO and wild-type mice had similar metabolic rates. Upon cold exposure at 4 °C, corin KO mice exhibited impaired thermogenic responses and developed hypothermia. In BAT from corin KO mice, the signaling pathway of p38 mitogen-activated protein kinase, peroxisome proliferator-activated receptor c coactivator 1a, and Ucp1 was impaired. In cell culture, ANP treatment increased Ucp1 expression in BAT-derived adipocytes from corin KO mice. These data indicate that corin mediated-ANP activation is an important hormonal mechanism in regulating adipose tissue function and body temperature upon cold exposure in mice

Effects of Pyrolysis Temperature on the Release Characteristics of Polycyclic Aromatic Hydrocarbons during Pyrolysis of Corn Stover Pellet

The release characteristics of polycyclic aromatic hydrocarbons during the pyrolysis of biomass remain poorly understood. This study investigated the effects of pyrolysis temperature on the polycyclic aromatic hydrocarbon release characteristics by analyzing both the transient vapor products and the physicochemical properties of corresponding biochar from the pyrolysis of corn stover pellets. The results revealed that the transient volatile compounds mainly included phenols, ketones, acids, furans, aldehydes, substances containing benzene ring, polycyclic aromatic compounds, and gaseous products. A range of 2 to 4 ring polycyclic aromatic hydrocarbons were generated at 400 to 700 °C with the peak at 560 °C, and the sum of relative content of polycyclic aromatic hydrocarbons ranged from 0.23% to 40.36%. For the biochar, the carbonization stage (400 to 700 °C) of corn stover pellets was further divided into three evolutionary stages, including the preliminary carbonization stage (380 to 480 °C), amorphous carbon structure stage (480 to 600 °C), and the stage of dehydrogenation and growth of aromatic rings (600 to 700 °C).The relationship between polycyclic aromatic hydrocarbon release in volatile compounds and H/C ratio of the biochar could be described by a power function

Carbonization temperature controlled thermal conductivity of graphitic carbon nanoparticles and their polymer composites

Carbon materials as versatile fillers have drawn increasing attention in thermal conductive polymer composites, however, the thermal conductivity (TC) regulation of them remains challenging. Herein, the tunable lattice thermal conductivity is reported for glucose derived graphitic carbon nanoparticles (GCPs) and their polymer composites. Both the in-plane (La) and out-of-plane (Lc) coherence lengths of GCPs increase with carbonization temperature in the range of 700 °C to 1300 °C. The intrinsic TC of GCPs film is directly extracted from the dependence of the Raman G peak frequency on the excitation laser power and the first order temperature coefficient. It is found that the in-plane lattice TC increases exponentially with both of the increasing La and decreasing defect concentration. The GCPs are then used as highly processible fillers to fabricate thermoset composites based on reactive benzoxazine (BA-a). The total TC of the poly(BA-a)/GCPs are found increase monotonically from 0.27 W·m-1·K-1 to 0.34 W·m-1·K-1 with the increasing graphitization levels of GCPs, and a clear signature of thermal percolation threshold at 6 vol% GCPs loadings is also observed