32 research outputs found
Privacy-preserving artificial intelligence in healthcare: Techniques and applications
There has been an increasing interest in translating artificial intelligence (AI) research into clinically-validated applications to improve the performance, capacity, and efficacy of healthcare services. Despite substantial research worldwide, very few AI-based applications have successfully made it to clinics. Key barriers to the widespread adoption of clinically validated AI applications include non-standardized medical records, limited availability of curated datasets, and stringent legal/ethical requirements to preserve patients' privacy. Therefore, there is a pressing need to improvise new data-sharing methods in the age of AI that preserve patient privacy while developing AI-based healthcare applications. In the literature, significant attention has been devoted to developing privacy-preserving techniques and overcoming the issues hampering AI adoption in an actual clinical environment. To this end, this study summarizes the state-of-the-art approaches for preserving privacy in AI-based healthcare applications. Prominent privacy-preserving techniques such as Federated Learning and Hybrid Techniques are elaborated along with potential privacy attacks, security challenges, and future directions. [Abstract copyright: Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Towards full-scale autonomy for multi-vehicle systems planning and acting in extreme environments
Currently, robotic technology offers flexible platforms for addressing many challenging problems that arise in extreme environments. These problems’ nature enhances
the use of heterogeneous multi-vehicle systems which can coordinate and collaborate
to achieve a common set of goals. While such applications have previously been
explored in limited contexts, long-term deployments in such settings often require
an advanced level of autonomy to maintain operability.
The success of planning and acting approaches for multi-robot systems are conditioned by including reasoning regarding temporal, resource and knowledge requirements, and world dynamics. Automated planning provides the tools to enable intelligent behaviours in robotic systems. However, whilst many planning approaches and
plan execution techniques have been proposed, these solutions highlight an inability
to consistently build and execute high-quality plans.
Motivated by these challenges, this thesis presents developments advancing state-of-the-art temporal planning and acting to address multi-robot problems. We propose a set of advanced techniques, methods and tools to build a high-level temporal
planning and execution system that can devise, execute and monitor plans suitable for long-term missions in extreme environments. We introduce a new task
allocation strategy, called HRTA, that optimises the task distribution amongst the
heterogeneous fleet, relaxes the planning problem and boosts the plan search. We
implement the TraCE planner that enforces contingent planning considering propositional temporal and numeric constraints to deal with partial observability about
the initial state. Our developments regarding robust plan execution and mission
adaptability include the HLMA, which efficiently optimises the task allocation and
refines the planning model considering the experience from robots’ previous mission
executions. We introduce the SEA failure solver that, combined with online planning, overcomes unexpected situations during mission execution, deals with joint
goals implementation, and enhances mission operability in long-term deployments.
Finally, we demonstrate the efficiency of our approaches with a series of experiments
using a new set of real-world planning domains.Engineering and Physical Sciences Research Council (EPSRC) grant EP/R026173/
Cryptography and Its Applications in Information Security
Nowadays, mankind is living in a cyber world. Modern technologies involve fast communication links between potentially billions of devices through complex networks (satellite, mobile phone, Internet, Internet of Things (IoT), etc.). The main concern posed by these entangled complex networks is their protection against passive and active attacks that could compromise public security (sabotage, espionage, cyber-terrorism) and privacy. This Special Issue “Cryptography and Its Applications in Information Security” addresses the range of problems related to the security of information in networks and multimedia communications and to bring together researchers, practitioners, and industrials interested by such questions. It consists of eight peer-reviewed papers, however easily understandable, that cover a range of subjects and applications related security of information
Demand controlled ventilation, case study on comfort and energy
The objectives of this research were to verify the operation of an installed system and to show the importance of a continuous monitoring of a facility installed in the south of Sweden and to compare the energy saving achievable with different ventilation systems with focus on keeping or improving the indoor comfort condition.The findings show the importance of continuous monitoring and the advantages of the choice of an advanced ventilation systemope
Photoevaporation versus core-powered mass-loss: model comparison with the 3D radius gap
The extreme ultraviolet (EUV)/X-ray photoevaporation and core-powered mass-loss models are both capable of reproducing the bimodality in the sizes of small, close-in exoplanets observed by the Kepler space mission, often referred to as the ‘radius gap’. However, it is unclear which of these two mechanisms dominates the atmospheric mass-loss that is likely sculpting the radius gap. In this work, we propose a new method of differentiating between the two models, which relies on analysing the radius gap in 3D parameter space. Using models for both mechanisms, and by performing synthetic transit surveys we predict the size and characteristics of a survey capable of discriminating between the two models. We find that a survey of ≳5000 planets, with a wide range in stellar mass and measurement uncertainties at a ≲5 per cent level is sufficient. Our methodology is robust against moderate false positive contamination of ≲10 per cent. We perform our analysis on two surveys (which do not satisfy our requirements): the California-KeplerSurvey and the Gaia–KeplerSurvey and find, unsurprisingly, that both data sets are consistent with either model. We propose a hypothesis test to be performed on future surveys that can robustly ascertain which of the two mechanisms formed the radius gap, provided one dominates over the other
Хмарна архітектура обробки даних в реальному часі для групи мобільних роботів
У магістерській дисертації розглянуто проблему синхронізації великих об’ємів даних в реальному часі, що надходять від групи мобільних роботів. В якості рішення обрано хмарні технології.
У розділі аналізу проблематики та постановки задачі визначено основні проблеми, що виникають при синхронізації даних такі як затримки в обробці, відмови в роботі сервісів, втрата даних та інші. Поставлено задачу розробити рішення, яке дозволить гнучко масштабувати систему, здійснювати відтворення втраченої інформації під час обробки та мінімізує затримки при надсилання сигналів керування.
У розділі вибору технологій проаналізовано можливі технологічні підходи та сервіси хмарного провайдера Amazon Web Services (AWS). Визначено перелік сервісів, що є основними компонентами в архітектурі: AWS IoT, AWS DynamoDB, AWS Kinesis та інші.
У розділі проектування архітектури розроблено архітектурні концепції, що вирішують поставлено задачу. Описано сервіси агрегацій даних, що є складовими компонентами спроектованої архітектури.
У розділі маркетингового аналізу стартап-проекту здійснено аналіз поточної ситуацію на ринку, створено стратегії та маркетинговий плани для впровадження рішення.
Розмір пояснювальної записки – 136 аркушів, містить 57 ілюстрацій, 26 таблиць, 8 додатків.The master's thesis deals with the problem of synchronizing large amounts of real-time data from a group of mobile robots. Cloud technologies were chosen as a solution.
In the section of the analysis of problems and statement of the problem the basic problems which arise at data synchronization such as delays in processing, failures in work of services, data loss and others are defined. The task is to develop a solution that will flexibly scale the system, reproduce lost information during processing and minimize delays in sending control signals.
The technology selection section analyzes possible technology approaches and services from the cloud provider Amazon Web Services (AWS). The list of services that are the main components in the architecture is defined: AWS IoT, AWS DynamoDB, AWS Kinesis and others.
In the section of architecture design, architectural concepts are developed that solve the problem. Data aggregation services that are components of the designed architecture are described.
In the section of marketing analysis of the startup project the analysis of a current situation in the market is carried out, strategies and marketing plans for implementation of the decision are created.
Explanatory note size – 136 pages, contains 57 illustrations, 26 tables, 8 applications
Biomimetic Polymeric Particles for Biomedical Therapeutics
The overall goal of this thesis is to investigate the various applications in which micron and nanometer sized polymeric particles could be synthesized to mimic biological cells and tissues to achieve a therapeutic effect. Particularly, the emphasis of this particle design is on the development of artificial antigen presenting cells (aAPC) for immunotherapy. Although the work in this thesis is varied in nature, this dissertation can be broadly categorized in three aims. In Aim 1, the role of shape in the design of aAPC was investigated with respect to use for cancer immunotherapy. An automated process was developed for the generation of anisotropic particles as well as a model system with which to evaluate their therapeutic efficacy in combination with immune checkpoint blockades. These therapeutics were then evaluated in a murine model and non-spherical aAPC were found to outperform spherical aAPC. Furthermore, the core polymeric material was modified to generate much stronger aAPC, with sufficient immunostimulation to engage the endogenous immune cells. In Aim 2, the role of surface chemistry was investigated in the design and use of particles for biomimetic drug delivery applications. Particles with biomimetic surface bound lipid membranes were synthesized to mimic the natural biological membrane of a cell. Anisotropic particles were synthesized and coated with naturally derived red blood cell membranes and were found to outperform equivalently coated spherical nanoparticles in various important drug delivery parameters such as pharmacokinetics and cellular uptake and elimination. In Aim 3, the role of stimulus response was investigated with respect to particle design. Particles with thermally triggered shape memory effect were synthesized and found to allow for spatiotemporally controlled shape control of spherical and ellipsoidal particles. In addition, focused ultrasound triggered drug delivery particles were synthesized to enable focal, noninvasive neuromodulation in a rat seizure model. The particle therapeutic systems developed as part of this thesis will have a wide and diverse impact on multiple fields in medicine including immunotherapy, regenerative medicine, and neuromodulation
Hybrid block and graft copolymers made from macrolactones and α-amino acids for applications as drug delivery nanosystems
Naturally produced peptides or proteins can be regarded as highly refined polymers. When synthetic polymers are married to proteins or peptides, the resulting bioconjugates can synergistically combine the properties of the individual components and overcome their separate limitations. This Thesis is focused on the study of hybrid copolymers based on polypeptides and polymacrolactones. Block and graft copolymers have been synthesized by making use of the ring opening polymerization method (ROP) mainly and extensively characterized including both their chemical structure and their structure in the solid state. The self-assembly properties of the new copolymers have been preliminary examined regarding their potential application as nanocarriers for pharmaceutical compounds.
This Thesis initially reports the ROP of w-pentadecalactone (PDL) using different amino-ended initiators and assisted by either organic or enzymatic catalysts. This method was then extended for the ROP of PDL using bisamino-ended poly(ethylene glycol) (PEG) for the preparation of poly(w-pentadecalactone)-b-poly(ethylene glycol)-b-poly(wpentadecalactone) [PPDLx-PEG-PPDLx] triblock copolymers. These amphiphilic ABA-type copolymers were able to selfassemble in water to form nanoparticles with diameters between 100 and 200 nm.
Hybrid copolymers of poly(ester-peptide) or poly(ether-ester-peptide) type exhibiting different architectures (e.g. diblock, triblock, graft or triblock/grafted) respectively, were then synthesized using as building blocks: poly(w-pentadecalactone), poly(globalide) (PGl), PEG as well as polypeptides derived from the L-glutamic acid (Glu), L-lysine (Lys), L-alanine (Ala) and L-phenylalanine (Phe) a-amino acids. The hybrid copolymers were synthesized through several stages depending on the desired architecture. The first stage in the preparation of these copolymers was the synthesis of macroinitiators from PDL or PGl containing either an amino group at the end of the chain or multiple amine groups along their polymeric chain. In the second stage, such macroinitiators were used to trigger the polymerization of the a-amino acid N-carboxyanhyrides (NCA) with the COOH group of L-glutamic acid and NH2 of L-lysine duly protected as g-benzyl-L-glutamate (BLG) and eNcarbobenzoxy-L-lysine (ZLL) respectively. Some copolymers containing BLG or ZLL units were treated with acids to render copolymers bearing the amino acids residues with their COOH or NH2 functionalities in the free form.
All of the synthesized copolymers were fully characterized through GPC and NMR spectroscopy. The thermal properties were studied by TGA and DSC techniques. The conformation adopted by the peptide-based copolymers in the solid-state was assessed by FTIR, and their crystalline structure was examined by X-ray diffraction using synchrotron radiation in most cases. The conformation in aqueous solution of water-soluble copolymers containing Glu or Lys residues in the free form was explored by circular dichroism.
The self-assembly behavior in aqueous medium of all the amphiphilic copolymers was investigated with the purpose of obtaining nanoparticles with the appropriated diameters required for their application as biomedical nanocarriers. The nanoparticles were duly characterized by light scattering and SEM and TEM microscopies. Block and graft copolymers were able to load doxorubicin and release it under pH control. Copolymers containing L-lysine were shown to be able of condensing DNA. The potential of these copolymers as DDS of anticancer drugs and vectors for transfection have been evidenced.Los polipéptidos o proteínas obtenidos de manera natural son considerados como polímeros altamente refinados. Cuando los polímeros sintéticos se unen a proteínas o polipéptidos, los sistemas bioconjugados que se obtienen pueden sinérgicamente combinar las propiedades de sus componentes individuales y mejorar las propias limitaciones que tienen por separado. La proteína o el elemento polipeptídico puede impartir propiedades bifuncionales al bioconjugado, mientras que el polímero sintético puede mejorar la estabilidad proteica, la solubilidad y la biocompatibilidad. Esta tesis está enfocada en el estudio de copolímeros híbridos basados en polipeptidos y polimacrolactonas. Copolímeros tipo bloque e injerto fueron sintetizados utilizando principalmente la polimerización por apertura de anillo y extensamente caracterizados tanto su estructura química, como su estructura en estado sólido. Las propiedades de auto-agregación de los nuevos copolímeros han sido anteriomente examinadas respecto a su potencial aplicación como nanotransportadores de compuestos farmacéuticos. Esta Tesis inicialmente reporta la homopolimerización de w-pentadecalactona (PDL) usando diferentes iniciadores aminoterminados mediante el uso de catalizadores tanto orgánicos como enzimáticos. Este se extiende a la ROP de PDL usando poli(etilén glicol) bisamino-terminado (PEG) para la preparar copolímeros tribloque poli(w-pentadecalactona)-b-poli(etilén glicol)-b-poli(w-pentadecalactona) [PPDLx-PEG-PPDLx]. Estos copolímeros de tipo ABA fueron capaces de auto-agregarse en agua para formar nanopartículas con diámetros entre 100 y 200 nm. Por otra parte, sistemas híbridos de tipo poli(éster-péptido) o poli(éter-éster-péptido) que presentan distintas arquitecturas (por ejemplo dibloque, tribloque, injerto, o tribloque-injertado) respectivamente, se sintetizaron utilizando como bloques de construcción derivados de macrolactonas (w-pentadecalactona), globalida) y a-amino ácidos (ácido L-glutámico (Glu), Llisina (Lys), L-alanina (Ala) y L-fenilalanina (Phe) así como poli(etien glicol) telequélico. Los copolímeros híbridos fueron sintetizados en varias etapas dependiendo de cuál fuese la arquitectura deseada. La primera etapa fue la preparación de los macroiniciadores a partir de PDL o PGl conteniendo en su estructura ya sea un grupo amino en el extremo de la cadena, o múltiples grupos aminos a lo largo de la cadena polimérica. En la segunda etapa, los macroiniciadores fueron utilizados en la polimerización de a-amino ácidos N-carboxianhídridos (NCA), con los grupos COOH del ácido L-glutámico y el grupo NH2 de la L-lisina apropiadamente protegidos como g-bencil-L-glutamato (BLG) y eN-carbobenzoxi-L-lisina (ZLL) respectivamente. Para los copolímeros que contienen bloques peptídicos de BLG o ZLL, las funcionalidades COOH o NH2 fueron regeneradas bajo condiciones ácidas, para producir así los copolímeros conteniendo el amino ácido en su forma libre. Todos los copolímeros sintetizados fueron completamente caracterizados mediante GPC y espectroscopia de RMN. Las propiedades térmicas fueron estudiadas por las técnicas de TGA y DSC. La conformación adoptada por los copolímeros en el estado sólido fue estudiada por FTIR, y su estructura cristalina fue analizada mediante difracción de rayos X usando radiación sincrotrón en la mayoría de los casos. La conformación en solución acuosa de los copolímeros solubles en agua, que contienen residuos de Glu o Lys, fue analizada por dicroísmo circular. Se estudió el comportamiento de todos los copolímeros para auto-agregarse en agua obteniéndose partículas con diámetros del orden nanométrico, como se demostró por DLS así como también por SEM y TEM, las cuales son apropiadas para ser aplicadas en biomedicina. Las nanopartículas de copolímeros dibloque y de injerto conteniendo ácido L-glutámico fueron capaces de incorporar doxorubicina y efectuar su liberación bajo control por medio del pH. Por otro lado, los copolímeros dibloque y de injerto con bloques conteniendo L-lisina mostraron la habilidad de condensar el ADN, demostrando así su potencial uso como vectores en transfección
Hybrid block and graft copolymers made from macrolactones and α-amino acids for applications as drug delivery nanosystems
Premi Extraordinari de Doctorat, promoció 2018-2019. Àmbit d’Enginyeria IndustrialNaturally produced peptides or proteins can be regarded as highly refined polymers. When synthetic polymers are married to proteins or peptides, the resulting bioconjugates can synergistically combine the properties of the individual components and overcome their separate limitations. This Thesis is focused on the study of hybrid copolymers based on polypeptides and polymacrolactones. Block and graft copolymers have been synthesized by making use of the ring opening polymerization method (ROP) mainly and extensively characterized including both their chemical structure and their structure in the solid state. The self-assembly properties of the new copolymers have been preliminary examined regarding their potential application as nanocarriers for pharmaceutical compounds.
This Thesis initially reports the ROP of w-pentadecalactone (PDL) using different amino-ended initiators and assisted by either organic or enzymatic catalysts. This method was then extended for the ROP of PDL using bisamino-ended poly(ethylene glycol) (PEG) for the preparation of poly(w-pentadecalactone)-b-poly(ethylene glycol)-b-poly(wpentadecalactone) [PPDLx-PEG-PPDLx] triblock copolymers. These amphiphilic ABA-type copolymers were able to selfassemble in water to form nanoparticles with diameters between 100 and 200 nm.
Hybrid copolymers of poly(ester-peptide) or poly(ether-ester-peptide) type exhibiting different architectures (e.g. diblock, triblock, graft or triblock/grafted) respectively, were then synthesized using as building blocks: poly(w-pentadecalactone), poly(globalide) (PGl), PEG as well as polypeptides derived from the L-glutamic acid (Glu), L-lysine (Lys), L-alanine (Ala) and L-phenylalanine (Phe) a-amino acids. The hybrid copolymers were synthesized through several stages depending on the desired architecture. The first stage in the preparation of these copolymers was the synthesis of macroinitiators from PDL or PGl containing either an amino group at the end of the chain or multiple amine groups along their polymeric chain. In the second stage, such macroinitiators were used to trigger the polymerization of the a-amino acid N-carboxyanhyrides (NCA) with the COOH group of L-glutamic acid and NH2 of L-lysine duly protected as g-benzyl-L-glutamate (BLG) and eNcarbobenzoxy-L-lysine (ZLL) respectively. Some copolymers containing BLG or ZLL units were treated with acids to render copolymers bearing the amino acids residues with their COOH or NH2 functionalities in the free form.
All of the synthesized copolymers were fully characterized through GPC and NMR spectroscopy. The thermal properties were studied by TGA and DSC techniques. The conformation adopted by the peptide-based copolymers in the solid-state was assessed by FTIR, and their crystalline structure was examined by X-ray diffraction using synchrotron radiation in most cases. The conformation in aqueous solution of water-soluble copolymers containing Glu or Lys residues in the free form was explored by circular dichroism.
The self-assembly behavior in aqueous medium of all the amphiphilic copolymers was investigated with the purpose of obtaining nanoparticles with the appropriated diameters required for their application as biomedical nanocarriers. The nanoparticles were duly characterized by light scattering and SEM and TEM microscopies. Block and graft copolymers were able to load doxorubicin and release it under pH control. Copolymers containing L-lysine were shown to be able of condensing DNA. The potential of these copolymers as DDS of anticancer drugs and vectors for transfection have been evidenced.Los polipéptidos o proteínas obtenidos de manera natural son considerados como polímeros altamente refinados. Cuando los polímeros sintéticos se unen a proteínas o polipéptidos, los sistemas bioconjugados que se obtienen pueden sinérgicamente combinar las propiedades de sus componentes individuales y mejorar las propias limitaciones que tienen por separado. La proteína o el elemento polipeptídico puede impartir propiedades bifuncionales al bioconjugado, mientras que el polímero sintético puede mejorar la estabilidad proteica, la solubilidad y la biocompatibilidad. Esta tesis está enfocada en el estudio de copolímeros híbridos basados en polipeptidos y polimacrolactonas. Copolímeros tipo bloque e injerto fueron sintetizados utilizando principalmente la polimerización por apertura de anillo y extensamente caracterizados tanto su estructura química, como su estructura en estado sólido. Las propiedades de auto-agregación de los nuevos copolímeros han sido anteriomente examinadas respecto a su potencial aplicación como nanotransportadores de compuestos farmacéuticos. Esta Tesis inicialmente reporta la homopolimerización de w-pentadecalactona (PDL) usando diferentes iniciadores aminoterminados mediante el uso de catalizadores tanto orgánicos como enzimáticos. Este se extiende a la ROP de PDL usando poli(etilén glicol) bisamino-terminado (PEG) para la preparar copolímeros tribloque poli(w-pentadecalactona)-b-poli(etilén glicol)-b-poli(w-pentadecalactona) [PPDLx-PEG-PPDLx]. Estos copolímeros de tipo ABA fueron capaces de auto-agregarse en agua para formar nanopartículas con diámetros entre 100 y 200 nm. Por otra parte, sistemas híbridos de tipo poli(éster-péptido) o poli(éter-éster-péptido) que presentan distintas arquitecturas (por ejemplo dibloque, tribloque, injerto, o tribloque-injertado) respectivamente, se sintetizaron utilizando como bloques de construcción derivados de macrolactonas (w-pentadecalactona), globalida) y a-amino ácidos (ácido L-glutámico (Glu), Llisina (Lys), L-alanina (Ala) y L-fenilalanina (Phe) así como poli(etien glicol) telequélico. Los copolímeros híbridos fueron sintetizados en varias etapas dependiendo de cuál fuese la arquitectura deseada. La primera etapa fue la preparación de los macroiniciadores a partir de PDL o PGl conteniendo en su estructura ya sea un grupo amino en el extremo de la cadena, o múltiples grupos aminos a lo largo de la cadena polimérica. En la segunda etapa, los macroiniciadores fueron utilizados en la polimerización de a-amino ácidos N-carboxianhídridos (NCA), con los grupos COOH del ácido L-glutámico y el grupo NH2 de la L-lisina apropiadamente protegidos como g-bencil-L-glutamato (BLG) y eN-carbobenzoxi-L-lisina (ZLL) respectivamente. Para los copolímeros que contienen bloques peptídicos de BLG o ZLL, las funcionalidades COOH o NH2 fueron regeneradas bajo condiciones ácidas, para producir así los copolímeros conteniendo el amino ácido en su forma libre. Todos los copolímeros sintetizados fueron completamente caracterizados mediante GPC y espectroscopia de RMN. Las propiedades térmicas fueron estudiadas por las técnicas de TGA y DSC. La conformación adoptada por los copolímeros en el estado sólido fue estudiada por FTIR, y su estructura cristalina fue analizada mediante difracción de rayos X usando radiación sincrotrón en la mayoría de los casos. La conformación en solución acuosa de los copolímeros solubles en agua, que contienen residuos de Glu o Lys, fue analizada por dicroísmo circular. Se estudió el comportamiento de todos los copolímeros para auto-agregarse en agua obteniéndose partículas con diámetros del orden nanométrico, como se demostró por DLS así como también por SEM y TEM, las cuales son apropiadas para ser aplicadas en biomedicina. Las nanopartículas de copolímeros dibloque y de injerto conteniendo ácido L-glutámico fueron capaces de incorporar doxorubicina y efectuar su liberación bajo control por medio del pH. Por otro lado, los copolímeros dibloque y de injerto con bloques conteniendo L-lisina mostraron la habilidad de condensar el ADN, demostrando así su potencial uso como vectores en transfección.Award-winningPostprint (published version