13780 research outputs found
Sort by
Copper Oxide Nanoparticles as Delivery Vehicles for Different Pt (II)-Drugs: Experimental and Theoretical Evaluation
No full textPlatinum(II)-based chemotherapeutic agents such as cisplatin, oxaliplatin, and nedaplatin are mainstays in the treatment of a wide range of solid tumors, yet their clinical application is severely restricted by rapid degradation, poor bioavailability, and dose-limiting side effects. These challenges arise in part from the drugs’ susceptibility to premature hydrolysis, off-target interactions in the bloodstream, and degradation in the gastrointestinal tract, which collectively limit their ability to reach and act on tumor cells. To address these limitations, we explored the use of copper(II) oxide nanoparticles (CuO NPs) as nanocarriers for platinum(II) drugs, aiming to enhance drug stability, loading, and controlled release. We systematically investigated the adsorption, interaction, and release behavior of cisplatin, oxaliplatin, and nedaplatin on CuO NPs using a suite of experimental techniques (UV–Vis spectroscopy, FTIR, BET surface area analysis, XRD, SEM) alongside periodic DFT calculations to elucidate the molecular-level mechanisms of drug-nanoparticle interaction. Our results demonstrate that cisplatin exhibits the strongest affinity for the CuO surface, achieving the highest entrapment efficiency (52%) and adsorption capacity
(949 mg/g) among the tested drugs. DFT simulations reveal that cisplatin forms highly stable tri- coordinated bonds with surface copper atoms (adsorption energy: –1.8 eV), in contrast to
oxaliplatin and nedaplatin, which display weaker binding and lower loading. The drug release studies further highlight the advantages of this system: cisplatin-CuO nanoparticles display a markedly sustained and controlled release profile, with only ~32% of the drug released over 72 hours, compared to the rapid and nearly complete release observed for free cisplatin under the same conditions. This controlled release is attributed to the strong coordination between cisplatin and the CuO surface, as well as the mesoporous structure of the nanoparticles, which together slow drug diffusion and hydrolysis. This research further studies the viability of green-synthesised CuO NPs as eco-friendly, cost-effective alternatives to commercial variants for platinum drug delivery, combining comparable performance with enhanced sustainability. The best two drugs (Cisplatin and Oxaliplatin) that showed better interactions with the CuO NPs surface were further studied using green synthesized nanoparticles. Green-synthesized CuO NPs also demonstrated substantial, though lower, loading performance, with cisplatin achieving 28.3% entrapment efficiency and 517 mg/g adsorption capacity. These results underscore the superior compatibility of cisplatin with CuO carriers and highlight the potential of both commercial and green-synthesized CuO NPs for platinum drug delivery
Law as Performance: Sovereignty, Legal Indeterminacy, and the Chinese Private Security Industry
Get PDFThis thesis examines how the legal indeterminacy of international law facilitates state evasion of accountability through the use of private military and security companies (PMSCs) as proxies in extraterritorial operations. Focusing on China’s deployment of PSCs to safeguard Belt and Road Initiative (BRI) projects, it argues that ambiguities within the doctrines of attribution and responsibility under the Articles on the Responsibility of States for Internationally Wrongful Acts (ARSIWA) create a permissive legal environment that enables states to outsource coercive functions without incurring formal liability. Drawing upon Hobbesian Realist theory, Carl Schmitt’s concept of the sovereign exception, and insights from Critical Legal Theory (CLT), the study demonstrates that legal ambiguity is not a flaw but a structural feature of the international legal order: one that perpetuates and conceals power asymmetries amongst states. China is presented as a ‘cautious Schmittian sovereign,’ strategically invoking or suspending legal norms to advance geopolitical aims while maintaining formal insulation from accountability under International Humanitarian Law (IHL) and state responsibility frameworks. By combining doctrinal analysis with critical theory, the thesis situates the Chinese case within a broader pattern in which international law functions less as a constraint and more as an instrument for managing visibility, shaping legality, and preserving sovereign discretion in the contemporary international order
Indoor Air Quality Monitoring in Learning Spaces: A Case Study in Cairo, Egypt
No full textFollowing the COVID-19 pandemic, ensuring good indoor air quality (IAQ) in educational spaces became crucial for safety and well-being. Poor IAQ can lead to health problems like respiratory issues, impacting students’ and educators’ performance. This study, conducted in American University in Cairo classrooms, aimed to assess IAQ and its implications on occupants. In-field measurements of CO2, temperature, humidity, VOCs, and PM2.5 were compared to outdoor air quality during different seasons. Preliminary results suggest significant variations in IAQ parameters across classrooms and seasons. CO2 levels consistently exceeded recommended limits, indicating poor ventilation and potential impacts on cognitive function and well-being. PM2.5 levels also exceeded safe limits during hot weather, raising concerns for respiratory health. These findings can inform policymakers and stakeholders in the education sector to implement strategies for improving IAQ in classrooms and create a healthier learning environment
Evolution of Lyrics of Egyptian Songs in the 20th Century
Get PDFDespite the extensive research by western countries on the song lyrics, almost nothing is known about the evolution of Egyptian song lyrics. The previous studies in the U.S. and U.K. revealed that lyrics were more pessimistic as time passed. In this study, 1891 Egyptian songs from 1920 to 2022 were analyzed using a sentiment analysis tool while searching for offensive words and retrieving their popularity scores from Spotify. The results aligned with those of the other regions in which the negativity of songs and the percentage of songs containing offensive words increased. However, there is a substantial increase in neutral songs and a continuous increase in the popularity score. Consequently, the results are crucial to understanding Egypt\u27s cultural changes over time and provide insight into the listeners\u27 emotions. This study contributes to a vast field of lyrical analysis, in which the Middle East region is falling behind, to guide future researchers to adapt, enhance and test for a larger sample
From Climate to Contracts: Advancing Temperature Options Pricing
Get PDFWhether it\u27s building dams to control rivers, crafting garments to withstand cold, or the simple act of carrying an umbrella, these actions reflect humanity\u27s precautionary behavior to adapt to nature. Weather derivatives are an extension of this adaptive behavior of the humankind seeking to hedge against weather related risks. A recent example that motivated this work is the loss of revenue incurred by Egypt during the six- day closure of the Suez Canal caused by the wedging of large vessel due to bad weather conditions. In this thesis, we model and price a temperature-based weather contract, using a dataset of historical weather metrics from Cairo, Egypt. We employ a stochastic approach based on the Ornstein-Uhlenbeck process, incorporating seasonal trends, mean reversion, and assuming monthly volatilities to model temperature dynamics. Our work extends the foundational methodology found in (Alaton et al., 2002), using Monte Carlo simulation and enhanced with a variance reduction technique using the control variate approach, leveraging a correlated Asian option under a Geometric Brownian Motion framework which significantly improves computational efficiency. Findings show that these methods could be effective when pricing temperature-based instruments and hence offering practical implications for industries like agriculture, energy, transportation, tourism, data center, etc. This research also aims to contribute to the broad understanding of the topic of Weather Derivatives as we explore use cases that fit different local economies, and we touch upon the challenges faced when pricing such instruments in the incomplete markets’ framework
The Consequences of Civil-Military Relations on Civil Wars in the Middle East
Get PDFTo unravel the complex dynamics surrounding the outbreak of civil wars in the aftermath of the Arab Spring uprisings, one of the first questions that come to mind is the reason why some Arab countries have witnessed civil wars whilst others have not. The civil-military relations play a significant role in the matter. While much of the existing literature on the causes of civil wars, there is a scarcity of papers that take into consideration the role of civil-military relations. This research focuses primarily on two variables independent variables, namely the civil-military relations and the diversified ethnicities alongside the dependent variable of civil wars. Understanding the regimes at work is vital to comprehend the causes of civil wars and how certain regimes have managed to suppress them while others have fallen into years-long civil wars
“Not Like Father, Like Son”: Public Sector Employment Reforms in Egypt
No full textThe slowing of public sector hiring has been a tool for sector downsizing and one of the markers of the reform trajectory in public administration in Egypt. The effect of this long-term and non-confrontational approach to downsizing on the workforce of the public sector is captured in this article using a unique national panel dataset. The analysis shows that the share of public sector employment has declined in a pattern punctuated by a number of critical junctures that shaped the trajectory of the adoption of New Public Management (NPM)-inspired policies. The data shows that the sector workforce is becoming more educated, older, and slightly more feminized. Despite the specificity of the context of Egypt, the analysis furthers the study of public sector reform trajectories and the complexity of the contextualization of NPM-inspired policies in countries with a socialist legacy in the global South
Fault-Tolerant Energy Harvesting System for Prolonging Pacemaker Lifetime
No full textThis paper focuses on prolonging the lifetime of pacemakers. Instead of just using a battery, a fault-tolerant energy harvesting system is designed; it is based on helical devices attached to the pacemaker leads. The design takes into consideration that the energy harvesting circuitry and a smaller battery will occupy the same area as the original battery. It is shown that the proposed circuit is able to supply the necessary power at 2.2V and tolerate the failure of any single component in the energy harvesting system in addition to several multiple failures. The small non-rechargeable battery will only supply current when the entire energy harvesting system fails
Emerging tendencies for the nano-delivery of gambogic acid: a promising approach in oncotherapy
No full textDespite the advancements in cancer therapies during the past few years, chemo/photo resistance, severe toxic effects, recurrence of metastatic tumors, and non-selective targeting remain incomprehensible. Thus, much effort has been spent exploring natural anticancer compounds endowed with biosafety and high effectiveness in cancer prevention and therapy. Gambogic acid (GA) is a promising natural compound in cancer therapy. It is the major xanthone component of the dry resin extracted from the Garcinia hanburyi Hook. f. tree. GA has significant antiproliferative effects on different types of cancer, and it exerts its anticancer activities through various pathways. Nonetheless, the clinical translation of GA has been hampered, partly due to its water insolubility, low bioavailability, poor pharmacokinetics, rapid plasma clearance, early degradation in blood circulation, and detrimental vascular irritation. Lately, procedures have been invented demonstrating the ability of nanoparticles to overcome the challenges associated with the clinical use of natural compounds both in vitro and in vivo. This review sheds light on the recent emerging trends for the nanodelivery of GA to cancer cells. To the best of our knowledge, no similar recent review described the different nanoformulations designed to improve the anticancer therapeutic activity and targeting ability of GA
Creative transdisciplinary architectural design as means for realising the sustainable development goals in the built environment
No full textAttaining the sustainable development goals (SDGs) requires solutions synthesising multidisciplinary knowledge. We argue that architecture embraces the creative transdisciplinary required to address sustainable development challenges in the built environment. The paper proposes a framework that builds on how architecture, as a practice, encompasses a series of design-thinking domains with open possibilities, potential, and power for innovation. This framework comprises nine design domains: building technology, building materials, building construction, building management systems, indoor climate, recycling advancements, spatial planning, urban planning, and strategic planning. The framework is used to analyse case studies and to highlight how creative transdisciplinarity, integrated through architectural design, advances the realisation of global goals. The findings emphasise the often synergistic and innovative nature of the architecture solutions that link to multiple design domains with the SDGs. The paper concludes with a matrix that shows the interlinkages between the design domains and the SDGs, revealing a complex array of connections and overlaps