17315 research outputs found
Sort by
Design and development of pH-sensitive nanocarriers using molecularly imprinted polymers for the targeted delivery of sodium thiopental
No full textSodium thiopental (STL) is an ultrashort-acting barbiturate that acts quickly on the brain, reduces levels of adrenaline, noradrenaline, and dopamine, and has neuroprotective properties. However, its side effects, especially in high doses, can be severe, including respiratory failure and cardiac complications. Molecularly imprinted polymers (MIPs) are three-dimensional polymeric networks that mimic the structure and functionality of target molecules. MIPs include benefits such as stability, selectivity, and cost-effectiveness. Combination with magnetic nanoparticles (MNPs) not only enhances their stability and biocompatibility but also provides magnetic separation capabilities. This research introduces the design and synthesis of pH-sensitive MIPs as targeted nanocarriers for the selective uptake and controlled release of STL molecules. The MIPs were synthesized in various forms, including magnetic core MIPs (MMIPs), standard MIPs (MIPs), and fiber-shaped MIPs (MIPF), to explore their comparative efficiency and structural advantages. Bemegride (BMG), an antidote structurally similar to STL, was utilized to evaluate the selectivity of these MIP systems. The formation of specific binding sites of STL on MIPs during the polymerization process leads to selective recognition and matches STL's shape, size, and functional groups. In this regard, all types of MIPs exhibited significant rebinding affinities over their non-imprinted polymer (NIP); specifically, MMIPs displayed a high affinity for uptake of STL (393.8 ± 1.328%) against BMG (360.72 ± 6.72%) over 24 h. The pH sensitivity of the nanocarriers was investigated in simulated gastric fluid (SGF) and simulated intestinal fluids (SIF) environments. The quantitative results indicated that the prepared nanocarriers showed a controlled release in SIF environments. MMIPs achieved a release efficiency for STL and BMG of approximately 57.7 ± 0.6% and 85.4 ± 4.6%, respectively, over a 78-hour period. These findings highlight the potential of MMIPs for dual-uptake and targeted release applications of STL in specific pH environments
Graphene-based materials: an innovative approach for neural regeneration and spinal cord injury repair
No full textSpinal cord injury (SCI), the most serious disease affecting the central nervous system (CNS), is one of contemporary medicine's most difficult challenges, causing patients to suffer physically, emotionally, and socially. However, due to recent advances in medical science and biomaterials, graphene-based materials (GBMs) have tremendous potential in SCI therapy due to their wonderful and valuable properties, such as physicochemical properties, extraordinary electrical conductivity, distinct morphology, and high mechanical strength. This review discusses SCI pathology and GBM characteristics, as well as recent in vitro and in vivo findings on graphenic scaffolds, electrodes, and injectable achievements for SCI improvement using neuroprotective and neuroregenerative techniques to improve neural structural and functional repair. Additionally, it suggests possible ideas and desirable products for graphene-based technological advances, intending to reach therapeutic importance for SCI
A theoretical analysis and empirical agenda for understanding the socioecology of adult attachment
No full textThe present review introduces the Socioecology of Adult Attachment (SEA) Model which argues that socioecological variation in interdependence is linked to variation in adult attachment processes. Ecologies of interdependence (characterised by blends of ecological threats, interdependent subsistence, and/or residential and relational stability) are associated with caregiving and socialisation practices that predict a relational focus in adult attachment, in which attachment-related expectations are largely defined by social obligations. In contrast, ecologies of independence (characterised by ecological safety, less interdependent subsistence, and/or residential and relational mobility) are associated with caregiving and socialisation practices that predict an individual focus in adult attachment, in which attachment-related expectations are defined by personal needs, concerns, and goals. The model generates three sets of predictions in contemporary research domains including the structure and composition of adult attachment networks, the formation of adult attachment orientations, and the alleviation and buffering of attachment insecurities
Improving last-mile delivery operations of electric vehicles using on-demand portable chargers
No full textWe investigate the utilization of portable chargers (PCs) for recharging delivery electric vehicles (EVs) en route. While EVs deliver customer orders within predefined time windows, PC delivery vans (PCDVs) are dispatched to supply PCs to EVs at designated customer locations during their visits. We refer to the arising problem as the Electric Vehicle Routing Problem with Time Windows and On-Demand Portable Chargers (EVRPTW-PC). The objective is to minimize overall operational costs by optimizing the fleet size. This study builds upon the Electric Vehicle Routing Problem with Time Windows and Mobile Charging Stations (EVRPTW-MCS) recently proposed in the literature, which primarily focused on recharging EVs at specific locations via Mobile Charging Stations (MCSs). While an MCS should stay parked while recharging an EV, PCDV can deliver the PC and continue its tour to serve other EVs, which improves its overall utilization. In addition, parking restrictions may limit the recharging service of MCSs. Initially, we present the EVRPTW-PC mathematical model of. Then, we propose a matheuristic approach that combines Variable Neighborhood Search alongside an exact method. Finally, we perform numerical experiments to compare the solutions obtained by using PCs and MCSs, and elaborate on the potential benefits of employing PCs
Human-robot collaboration in surgery at the nexus of knowledge, agency, and ownership
Get PDFHuman-robot collaboration is transforming healthcare, particularly in surgical environments. Robotic surgery systems, embodied by advanced AI, are pivotal in augmenting human expertise across specialties such as gynecology and laparoscopic surgery. However, critical gaps remain in understanding how knowledge, agency, and ownership shape these collaborations. We address these gaps through semi-structured interviews with eleven healthcare professionals from diverse surgical roles. Our findings reveal that while robotic systems enhance precision and efficiency, they also generate tensions related to professional autonomy, control, and responsibility. Participants expressed ambivalent views, simultaneously demonstrating trust in the technology and strategic disengagement to preserve human authority. Concepts such as avatarization, the perception of robots as extensions of the self, and strategic ignorance emerged as key mechanisms through which professionals manage this evolving relationship. These dynamics point to the need for rethinking human–robot roles as fluid and co-constructed rather than fixed or hierarchical. We also emphasize the possible use of robotic systems to promote inclusivity and accessibility in healthcare while identifying structural barriers such as high costs, dependence on proprietary technology, and uneven organizational readiness. Our research enhances theoretical frameworks on human–robot interaction, providing practical and conceptual insights for the creation of equitable, sustainable, and context-sensitive robotic healthcare systems
Design and manufacturing of a high-speed motorized spindle: engineering challenges and insights
No full textThis paper presents the design and manufacturing of a high-speed motorized spindle, developed as part of a project focused on addressing the challenges of high-speed spindle performance. The spindle features an integrated motor drive, air and water cooling, and an oil-air lubrication system. Critical challenges tackled during the project include ensuring stability at high speeds, selecting optimal bearings, optimizing shaft geometry, and managing thermal expansion. The spindle was designed and manufactured in-house, providing hands-on experience and practical insights into both design and production aspects. Advanced cooling and lubrication systems were incorporated to ensure reliable performance under demanding conditions. Detailed practical guidelines for high-speed spindles, especially with integrated motor drives and modular cooling and lubrication systems, are scarce in the literature. This paper shares the challenging aspects from the design and manufacturing process in addition to the analytical and numerical modeling efforts, offering valuable takeaways to improve spindle performance in high-speed machining applications. The performance of the spindle is evaluated against a commercial benchmark design with dynamic and thermal experiments. These insights provide guidance for future high-speed spindle designs and contribute to their practical implementation in academic and industrial environments
Targeting the bioenergetics of a resistant tumor: clinical insights into OXPHOS inhibition for cancer therapy
No full textAlthough a century has passed since Otto Warburg’s discovery of the glycolytic pathway of energy production by many malignant tumors compared to normal tissues, current data cast doubt on the universality of this hypothesis. In particular, numerous recent papers suggest that in response to chemotherapy or radiotherapy, many malignant tumors prefer to activate mitochondrial oxidative phosphorylation (OXPHOS). Moreover, data from many laboratories, including our own, show that OXPHOS and related redox proteins are preferential metabolic pathways for resistant tumors and cells, and therefore may be targeted specifically in cases of tumor relapse. This work aims to provide an overview of the use of OXPHOS inhibition as an alternative therapy approach for resistant tumors and includes a description of the confirmed key mechanisms and the results of clinical trials of OXPHOS inhibitors and possible side effects arising therefrom. We mainly discuss original papers and clinical trials published in the past 5–7 years
Evaluating the influence of service conditions on the out-of-plane and in-plane loading performance and damage behavior of unidirectional CF/PEKK composites for aerospace applications
No full textEnsuring the structural reliability of composite materials requires a thorough understanding of their performance under various service conditions, particularly in demanding aerospace environments. This study investigates the influence of low-temperature (LT), high-temperature (HT), and cyclic-hygrothermal (CHT) conditions—representing a broad spectrum of realistic operational environments—on the out-of-plane and in-plane mechanical properties and damage behavior of unidirectional carbon fiber/poly-ether-ketone-ketone (CF/PEKK) composites. To assess the impact of these environmental factors on mechanical performance and failure mechanisms, a comprehensive experimental approach is employed, incorporating double-cantilever beam (DCB) tests with acoustic emission (AE) monitoring, end-notched flexure (ENF), short beam shear (SBS), and three-point bending (3-PB), alongside microscopic analysis. Results emphasize the significant influence of environmental conditions on the mechanical performance and damage evolution of CF/PEKK composites. Under LT conditions, flexural strength and deflection improve due to enhanced interlaminar interactions, despite increased brittleness in the matrix. LT conditioning yields the highest interlaminar shear strength (ILSS) and damage nucleation energy. However, LT-conditioned specimens exhibit brittle fractures with unstable crack propagation and frequent fiber-tow breakage during DCB and ENF tests. Conversely, HT conditions reduce flexural strength, but crack onset is delayed because of increased ductility. HT conditioning decreases ILSS and stiffness due to thermal softening. CHT conditioning results in intermediate flexural strength due to matrix plasticization, yet induces substantial inelastic deformation, multiple delaminations, and reduced interlaminar fracture toughness. These novel findings highlight the critical role of environmental factors in designing thermoplastic-based composites for aerospace applications, emphasizing the need for optimization to ensure reliable performance under diverse conditions
Multiphysics modeling of a novel MEMS accelerometer based on electromagnetic induction
No full textThis work reports on the development of a micromachined monolithic single-axis electromagnetic accelerometer based on the relative motion between the windings of a concentric planar transformer, whose internal inductor is suspended. The mechanical and electromagnetic modelling of the sensor is presented, as well as the implementation of a virtual read-out circuit. Electromagnetic simulations were used to extract the electrical performance parameters in the form of a lumped-element model. The results demonstrate that rotation between the two windings leads to an approximately linear variation in the mutual inductance. Furthermore, measurement circuit simulations revealed that the sensor could achieve an in-plane acceleration sensitivity of 32.9 mV/g for a matched network when excited with 3Vpp, 100 MHz excitation voltage
Development of anisotropic nanofibrous hybrid membranes coated with upcycled graphene for enhanced adsorption of emerging contaminants from drinking water
No full textNanofibrous membranes are widely recognized for their outstanding separation efficiency and represent a promising solution to the global water crisis. However, challenges such as suboptimal dimensional design and weak interfacial stability must be addressed through innovative structural strategies and effective additive incorporation. To this end, a novel, thick, anisotropic hybrid membrane was developed in this study by synergistically combining electrospinning and salt-leaching techniques, allowing precise control over membrane thickness and internal pore architecture while achieving a remarkable porosity of 93.5 %. The successful incorporation of upcycled graphene nanoplatelets (GNPs) through a multistep process enhanced pollutant adsorption and optimized interactions between GNPs and contaminants through the tailored multiscale structure. This design led to outstanding adsorption performance, with removal efficiencies of 99 % for ofloxacin, 97 % for bisphenol A, 88 % for caffeine, 72 % for paracetamol, and 36 % for iopamidol. Under dynamic flow conditions, a high adsorption capacity (1.2 mg/g) was maintained even at low contaminant concentrations, while excellent reusability and minimal GNP release confirmed strong nanoparticle adhesion. These findings underscore the strong potential of the developed membrane for real-world environmental remediation, highlighting its advanced functionality. Moreover, the use of biodegradable, non-toxic polymers and upcycled GNPs enhances the overall sustainability of the system, positioning it as a promising next-generation technology for effective and environmentally responsible water treatment