1. Review of potential drug-eluting contact lens technologiesTina Lovrec-Krstič, Kristjan Orthaber, Uroš Maver, Tomislav Šarenac, 2023, pregledni znanstveni članek Opis: The field of ophthalmology is expanding exponentially, both in terms of diagnostic and therapeutic capabilities, as well as the worldwide increasing incidence of eye-related diseases. Due to an ageing population and climate change, the number of ophthalmic patients will continue to increase, overwhelming healthcare systems and likely leading to under-treatment of chronic eye diseases. Since drops are the mainstay of therapy, clinicians have long emphasised the unmet need for ocular drug delivery. Alternative methods, i.e., with better compliance, stability and longevity of drug delivery, would be preferred. Several approaches and materials are being studied and used to overcome these drawbacks. We believe that drug-loaded contact lenses are among the most promising and are a real step toward dropless ocular therapy, potentially leading to a transformation in clinical ophthalmic practice. In this review, we outline the current role of contact lenses in ocular drug delivery, focusing on materials, drug binding and preparation, concluding with a look at future developments.
Ključne besede: contact lens materials, advanced ocular drug delivery, dropless ocular therapy, drug-laden contact lens
Objavljeno v DKUM: 03.12.2024; Ogledov: 0; Prenosov: 0
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2. PREPARATION OF AMINO ACID AND PEPTIDE POLYSACCHARIDE DERIVATIVES AND THEIR APPLICATION AS BIOMATERIALS : doctoral dissertationAna Bratuša, 2024, doktorska disertacija Opis: The derivatization of the polysaccharide dextran with N-protected amino acids (Boc-L-Phenylalanine, BocGlycine, Boc-L-Cysteine, and Boc-L-Cysteine-S-Trt) and peptides (Boc-L-DiPhenylalanine, Boc DiGlycine, and 2,5-diketopiperazine) as the basis for biomaterial preparation is presented in this Doctoral Dissertation. Such prepared dextran derivatives are intended to mimic the proteoglycan complex (PGs), one of the most important structural and functional biomacromolecules in the extracellular matrix (ECM) of tissue. Nowadays, developments in biomaterials are focusing increasingly on the preparation and use of biomimetic molecular structures to achieve positive results in tissue engineering (TE) and drug delivery. Designing and synthesizing these biomimetic materials, however, requires sophisticated chemical and material preparation methods, knowledge that is, currently, unexplored.
In this work, we developed a suitable procedure for dextran derivatization, and investigated the most optimal reaction or deprotection conditions (temperature and time) and isolation/purification methods. The structures of the obtained BocPhe-Dex, BocGly-Dex, BocCys-Dex, and BocSTLC-Dex were analyzed with FTIR, NMR, SEC-MALS, and EA. The results showed that dextran derivatization was successful in all cases except in the case of dextran derivatization with BocCys. Investigation of the effect of the derivatization conditions and purification on the stability, purity, and other important chemical and physical properties of the obtained product, showed that the temperature and time of derivatization do not have a bigger effect on the products' properties, while the purification method, on the other hand, has. Its effect is visible in the product's purity and mass yields of products prepared under the same reaction conditions.
Derivatization of dextran with peptides (Boc-L-DiPhenylalanine, BocDiGlycine, and 2,5-diketopiperazine) was performed using the CDI coupling agent or Amberlite-IR 120 as a catalyst. The products were analyzed with FTIR and 1H and 13C NMR. The results showed successful dextran derivatization in the case of BocDiPhenylalanine and BocDiGlycine, while, in the case of 2,5-diketopiperazine, a reaction covalent bond with the dextran was not confirmed.
BocPhe-Dex and BocSTLC-Dex were selected as the most optimal amino acid-dextran derivatives for further preparation of 3D formulations in the shape of nanoparticles (NPs). Nanoparticles were prepared with the emulsion/solvent evaporation method from the obtained BocPhe-Dex and BocSTLC-Dex products (prepared in the first stage of this Doctoral Dissertation). SEM analysis showed that the prepared NPs were homogeneous and nicely spherical, with an average dry diameter of 325 ± 118 nm in the case of BocSTLC-Dex, and 1039 ± 382 nm in the case of NPs prepared from BocPhe-Dex. All the prepared NPs retained their proper spherical shape and stability during the acidic treatment, and so confirmed their potential for further functionalization and applications for drug delivery. The BocSTLC-Dex NPs were also evaluated with cell viability tests, which showed that the prepared NPs were not cytotoxic, one of the most important characteristics for the drug delivery applications of NPs.
This work serves as a basis for further studies on the derivatization of polysaccharides with amino acids and peptides, and their application in tissue engineering or drug delivery.
Ključne besede: Amino Acid-Dextran derivatives, Peptide-Dextran derivatives, Proteoglycan complex, 3D formulation, Nanoparticles, Drug delivery
Objavljeno v DKUM: 18.10.2024; Ogledov: 0; Prenosov: 23
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3. Active BIM system for optimized multi-project ready-mix-concrete deliveryHana Begić, Mario Galić, Uroš Klanšek, 2024, izvirni znanstveni članek Opis: Purpose – Ready-mix concrete delivery problem (RMCDP), a specific version of the vehicle routing problem (VRP), is a relevant supply-chain engineering task for construction management with various formulations and solving methods. This problem can range from a simple scenario involving one source, one material and one destination to a more challenging and complex case involving multiple sources, multiple materials and multiple destinations. This paper presents an Internet of Things (IoT)-supported active building information modeling (BIM) system for optimized multi-project ready-mix concrete (RMC) delivery. Design/methodology/approach – The presented system is BIM-based, IoT supported, dynamic and automatic input/output exchange to provide an optimal delivery program for multi-project ready-mix-concrete problem. The input parameters are extracted as real-time map-supported IoT data and transferred to the system via an application programming interface (API) into a mixed-integer linear programming (MILP) optimization model developed to perform the optimization. The obtained optimization results are further integrated into BIM by conventional project management tools. To demonstrate the features of the suggested system, an RMCDP example was applied to solve that included four building sites, seven eligible concrete plants and three necessary RMC mixtures. Findings – The system provides the optimum delivery schedule for multiple RMCs to multiple construction sites, as well as the optimum RMC quantities to be delivered, the quantities from each concrete plant that must be supplied, the best delivery routes, the optimum execution times for each construction site, and the total minimal costs, while also assuring the dynamic transfer of the optimized results back into the portfolio of multiple BIM projects. The system can generate as many solutions as needed by updating the real-time input parameters in terms of change of the routes, unit prices and availability of concrete plants. Originality/value – The suggested system allows dynamic adjustments during the optimization process, andis adaptable to changes in input data also considering the real-time input data. The system is based on spreadsheets, which are widely used and common tool that most stakeholders already utilize daily, while also providing the possibility to apply a more specialized tool. Based on this, the RMCDP can be solved using both conventional and advanced optimization software, enabling the system to handle even large-scale tasks as necessary.
Ključne besede: active building information modeling, BIM, internet of things, IoT, multi-project environment, optimization, ready-mix-concrete delivery, RMC
Objavljeno v DKUM: 11.09.2024; Ogledov: 32; Prenosov: 7
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4. Implementation of integrated primary care for patients with diabetes and hypertension : a case from SloveniaZalika Klemenc-Ketiš, Nataša Stojnić, Črt Zavrnik, Nina Ružić Gorenjec, Katrien Danhieux, Majda Mori-Lukančič, Tonka Poplas-Susič, 2021, izvirni znanstveni članek Opis: Introduction: Research on models of integrated health care for hypertension and diabetes is one of the priority issues in the world. There is a lack of knowledge about how integrated care is implemented in practice. Our study assessed its implementation in six areas: identification of patients, treatment, health education, self-management support, structured collaboration and organisation of care. Methods: This was a mixed methods study based on a triangulation method using quantitative and qualitative data. It took place in different types of primary health care organisations, in one urban and two rural regions of Slovenia. The main instrument for data collection was the Integrated Care Package (ICP) Grid, assessed through four methods: 1) a document analysis (of a current health policy and available protocols; 2) observation of the infrastructure of health centres, organisation of work, patient flow, interaction of patients with health professionals; 3) interview with key informants and 4) review of medical documentation of selected patients. Results: The implementation of the integrated care in Slovenia was assessed with the overall ICP score of 3.7 points (out of 5 possible points). The element Identification was almost fully implemented, while the element Self-management support was weakly implemented. Discussion: The implementation of the integrated care of patients with diabetes and/ or hypertension in Slovenian primary health care organisations achieved high levels of implementation. However, some week points were identified. Conclusion: Integrated care of the chronic patients in Slovenia is already provided at high levels, but the area of self-management support could be improved.
Ključne besede: delivery of health care, integrated, primary care, self-care
Objavljeno v DKUM: 27.08.2024; Ogledov: 105; Prenosov: 4
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5. Green sourcing: effects on supplier performance metrics in fast food restaurants in frontier marketsPaul Mukucha, Bongani E. Mushanyuri, Divaries Cosmas Jaravaza, 2021, izvirni znanstveni članek Opis: Following the banning of expanded polystyrene packaging material, the fast food restaurant industry was serendipitously plunged into green sourcing initiatives for its packaging materials leading to heightened efforts on evaluating the suitability of various suppliers of green packaging material. This study therefore sought to assess the performance of selected suppliers on supplier performance metrics of total cost of ownership, quality of sourced material and delivery performance, in Zimbabwe’s restaurant industry. Methodology: Data was collected from senior procurement officers of 30 officially registered fast food restaurants in Zimbabwe. Each restaurant randomly selected 5 suppliers from their supplier lists. Each unit was asked to rate their 5 major suppliers of packaging material leading to an effective sample size of 150 suppliers. Structural Equation Modeling (SEM) was used to analyse data in AMOS. The five steps in SEM, that is: model specification, model identification, parameter estimation, model evaluation and modification were done. Findings: The findings in this study revealed that green sourcing leads to improved procurement performance in terms of total cost of ownership, quality of the materials sourced, and delivery performance. Implications for theory and practice: It was therefore recommended that practically the restaurant industry should explore various options of green packaging material ranging from recyclable and reusable plastic, paper, aluminium and steel material. Originality and value: Although the study was done in a single market, there is dearth in literature on green sourcing in frontier markets, of which the study provides empirical evidence from the restaurant industry in SubSaharan Africa.
Ključne besede: green sourcing, supplier evaluation, fast food restaurant, frontier markets, supplier performance metrics, green packaging material, total cost of ownership, quality of sourced material, delivery performance
Objavljeno v DKUM: 23.08.2024; Ogledov: 80; Prenosov: 7
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6. Multifunctional iron oxide nanoparticles as promising magnetic biomaterials in drug elivery : a ǂreviewKatja Vasić, Željko Knez, Maja Leitgeb, 2024, pregledni znanstveni članek Ključne besede: multifunctional biomaterials, bio-composites, nanocarriers, magnetic nanoparticles, modification, drug delivery
Objavljeno v DKUM: 20.08.2024; Ogledov: 72; Prenosov: 6
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7. Sustainable operations of last mile logistics based on machine learning processesJerko Oršič, Borut Jereb, Matevž Obrecht, 2022, izvirni znanstveni članek Opis: The last-mile logistics is regarded as one of the least efficient, most expensive, and polluting part of the entire supply chain and has a significant impact and consequences on sustainable delivery operations. The leading business model in e-commerce called Attended Home Delivery is the most expensive and demanding when a short delivery window is mutually agreed upon with the customer, decreasing possible optimizing flexibility. On the other hand, last-mile logistics is changing as decisions should be made in real time. This paper is focused on the proposed solution of sustainability opportunities in Attended Home Delivery, where we use a new approach to achieve more sustainable deliveries with machine learning forecasts based on real-time data, different dynamic route planning algorithms, tracking logistics events, fleet capacities and other relevant data. The developed model proposes to influence customers to choose a more sustainable delivery time window with important sustainability benefits based on machine learning to predict accurate time windows with real-time data influence. At the same time, better utilization of vehicles, less congestion, and fewer failures at home delivery are achieved. More sustainable routes are selected in the preplanning process due to predicted traffic or other circumstances. Increasing time slots from 2 to 4 h makes it possible to improve travel distance by about 5.5% and decrease cost by 11% if we assume that only 20% of customers agree to larger time slots.
Ključne besede: supply chain management, real-time, home delivery, business modeling, e-commerce, time window
Objavljeno v DKUM: 19.02.2024; Ogledov: 265; Prenosov: 51
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8. Power line magnetic field deviations for three different definitions of current unbalanceDanka Antic, Anamarija Juhas, Miodrag Milutinov, 2019, strokovni članek Opis: An estimation procedure of the public's exposure to the low-frequency magnetic field generated by overhead power lines, according to the international standards, implies measurement and an extrapolation. It is necessary to measure both the magnetic field around the lines and the current in the lines simultaneously. The extrapolation procedure implies the calculation of the maximum magnetic field that will occur when the line current achieves its maximum. The calculation relies on a proportion between the current in the power line and the magnetic field around the power line, which is valid only when the currents are balanced. Unfortunately, the standards do not cover the unbalanced cases. The relation between the current unbalance and magnetic field could improve the estimation procedure. In the literature, several different definitions of the current unbalance could be found. In this paper, a comparison of three different definitions of current unbalance and their relation to the deviation of a magnetic field are considered. The magnetic field is calculated in the vicinity of the bus bar. The same procedure could also be applied around overhead power lines. The definitions for the current unbalance used in this paper are derived from the existing definitions of the voltage unbalance. Only one of these three definitions considers phase unbalance. The relationships between current unbalance and the maximum deviation of the magnetic field are found to be proportional.
Ključne besede: magnetic field, power delivery, measurement, public exposure assessment
Objavljeno v DKUM: 22.12.2023; Ogledov: 506; Prenosov: 4
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9. Barriers to applying last-mile logistics in the Egyptian market : an extension of the technology acceptance modelMohamed Amr Sultan, Tomaž Kramberger, Mahmoud Barakat, Ahmed Hussein Ali, 2023, izvirni znanstveni članek Opis: Drawing on the Technology Acceptance Model (TAM), this research aims to investigate
the impact of social, environmental, and technological barriers on adopting the last-mile logistics
application. This research used a self-administrative questionnaire to collect 1060 respondents from
the Egyptian market and analysed it using partial least square structural equation modeling. The
findings revealed that some elements could obstruct the implementation of last-mile delivery technologies, namely complexity, collaboration efforts between users and application developers and the
impact of technical knowledge and expertise on the potentially involved users. The sharing economy
helps organisations reduce contaminants, emissions and carbon footprints, and last-mile logistics is
one of the tools of the sharing economy that can enhance the productivity and competitiveness of
logistics and boost consumer fulfillment. This research will help enhance organisations’ performance
in Egypt as a developing country and push towards applying environmental sustainability practices,
as it introduces a tool to enhance customer satisfaction and reduce emissions by illustrating how
last-mile logistics can be implemented. This is particularly important as last-mile logistics face some
implementation barriers, especially in developing countries. In addition, it will help in extending
the theory through conceptualising its abstract ideas with the research variables and applying it in a
different context.
Ključne besede: technology acceptance model, technology implementation barrier, last-mile delivery, sustainability, sharing economy, structural equation modelling
Objavljeno v DKUM: 15.12.2023; Ogledov: 545; Prenosov: 27
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10. Drone last mile delivery : an assessment of the viable market and security potential of drone deliveryIgor Grofelnik, Uroš Godnov, Marjan Sternad, 2022, izvirni znanstveni članek Opis: Purpose: the paper includes a review of the literature in the field of drones, drone technology, possible implementation in the field of the last mile concept, legislation, suitability of technology in the field of security, weather conditions, social acceptance and later focuses on checking the possible implementation of drones according to the set parameters.
Methodology: for the purposes of research and obtaining answers to the posed research question and hypotheses, we used the method of literature review in the selected field, panel data analysis, conducted interviews with experts in the field of delivery drones in the Republic of Slovenia, and conducted secondary research.
Results: the results show an assessment of the possible implementation of drones based on the analysis of the obtained data and interviews. We determined a realistic assessment of the potential of delivery drones, in which we included several vital aspects necessary for implementation.
Conclusion: it was found that the current technology is not yet fully adequate, and significant technological improvements are also needed. It is also necessary to plan integrated urban spatial solutions that will enable safe and efficient delivery in the supply chain. Namely, delivery with drones is currently ineffective due to flight safety, harmful sound emissions and the inability to fly in bad weather conditions. Based on a literature review and a survey among large logistics companies, it was found that there are still many barriers to implementation due to legal norms and regulations, which are currently very constructive. It is unlikely, however, that parcel delivery will take off in an urban environment soon, as there are still many unknowns. With proper planning and use of suburban consolidation centres, e-vans, e-cars and bicycles are currently economically viable for last mile delivery.
Ključne besede: drones, last mile, urban logistics, parcel delivery
Objavljeno v DKUM: 18.09.2023; Ogledov: 519; Prenosov: 13
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