Search results for: Yihenew Simegniew Birhan
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 5

Search results for: Yihenew Simegniew Birhan

5 Diselenide-Linked Redox Stimuli-Responsive Methoxy Poly(Ethylene Glycol)-b-Poly(Lactide-Co-Glycolide) Micelles for the Delivery of Doxorubicin in Cancer Cells

Authors: Yihenew Simegniew Birhan, Hsieh Chih Tsai

Abstract:

The recent advancements in synthetic chemistry and nanotechnology fostered the development of different nanocarriers for enhanced intracellular delivery of pharmaceutical agents to tumor cells. Polymeric micelles (PMs), characterized by small size, appreciable drug loading capacity (DLC), better accumulation in tumor tissue via enhanced permeability and retention (EPR) effect, and the ability to avoid detection and subsequent clearance by the mononuclear phagocyte (MNP) system, are convenient to improve the poor solubility, slow absorption and non-selective biodistribution of payloads embedded in their hydrophobic cores and hence, enhance the therapeutic efficacy of chemotherapeutic agents. Recently, redox-responsive polymeric micelles have gained significant attention for the delivery and controlled release of anticancer drugs in tumor cells. In this study, we synthesized redox-responsive diselenide bond containing amphiphilic polymer, Bi(mPEG-PLGA)-Se₂ from mPEG-PLGA, and 3,3'-diselanediyldipropanoic acid (DSeDPA) using DCC/DMAP as coupling agents. The successful synthesis of the copolymers was verified by different spectroscopic techniques. Above the critical micelle concentration, the amphiphilic copolymer, Bi(mPEG-PLGA)-Se₂, self-assembled into stable micelles. The DLS data indicated that the hydrodynamic diameter of the micelles (123.9 ± 0.85 nm) was suitable for extravasation into the tumor cells through the EPR effect. The drug loading content (DLC) and encapsulation efficiency (EE) of DOX-loaded micelles were found to be 6.61 wt% and 54.9%, respectively. The DOX-loaded micelles showed initial burst release accompanied by sustained release trend where 73.94% and 69.54% of encapsulated DOX was released upon treatment with 6mM GSH and 0.1% H₂O₂, respectively. The biocompatible nature of Bi(mPEG-PLGA)-Se₂ copolymer was confirmed by the cell viability study. In addition, the DOX-loaded micelles exhibited significant inhibition against HeLa cells (44.46%), at a maximum dose of 7.5 µg/mL. The fluorescent microscope images of HeLa cells treated with 3 µg/mL (equivalent DOX concentration) revealed efficient internalization and accumulation of DOX-loaded Bi(mPEG-PLGA)-Se₂ micelles in the cytosol of cancer cells. In conclusion, the intelligent, biocompatible, and the redox stimuli-responsive behavior of Bi(mPEG-PLGA)-Se₂ copolymer marked the potential applications of diselenide-linked mPEG-PLGA micelles for the delivery and on-demand release of chemotherapeutic agents in cancer cells.

Keywords: anticancer drug delivery, diselenide bond, polymeric micelles, redox-responsive

Procedia PDF Downloads 78
4 Teachers’ Conception of and Perception towards the New Curriculum of Ethiopian Higher Education: A Case of Debre Birhan University

Authors: Kassahun Tilahun Dessie

Abstract:

The purpose of this study was to explore the awareness of teachers and the attitude they have to the curriculum they implement as well as to assess the actual and desired magnitude of teachers' participation in curriculum development process. It also aimed at investigating the factors that affect teachers' level of conception and perception towards the new higher education curriculum. The study was carried out in Debre Birhan University. Teachers, course coordinators, team leaders and presidents were included in the study as research subjects. Teachers were proportionally selected from each department (of the six faculties) based on available sampling technique. Accordingly, a total of 103 teachers were chosen as a subject of the study. In order to collect first hand data from the teachers, a questionnaire with four parts was developed by the researcher. To this end, scales were designed for measuring the extent of teachers' awareness and attitude. Each of the scales encompasses 11 and 17 items respectively. An open ended questionnaire was also attached for the purpose of obtaining elaborated data on the issue. Information was also obtained from interviews with presidents, team leaders and course coordinators. The data obtained were analyzed qualitatively using descriptive statistical tools. The overall results of the analysis revealed that the awareness of teachers on the curriculum was low. The meager participation of teachers in the process of curriculum development and the deficiency of trainings on the concern were major factors. Teachers' perception towards the existence and implementation of the new curriculum was also inclined to the negative, though difficult to generalize. Lack of awareness, administrators poor approach and lack of facilitating appropriate incentives as well as absence of room for evaluating the curriculum etc plays big role in endangering teachers attitude while the up to datedness of the new curriculum, involvement of teachers in the curriculum development process, the wide ranging quality of the new curriculum etc laid a better ground to boost teachers attitude towards the curriculum. This may have implication to the university in that there is a need to facilitate workshops or awareness creation trainings, to have positive and cooperative administrators, and embracing committed teachers to implement the curriculum efficiently.

Keywords: conception, perception, curriculum, higher education, Ethiopia

Procedia PDF Downloads 465
3 Utilization, Barriers and Determinants of Emergency Medical Services in Mekelle City, Tigray, Ethiopia: A Community-Based Cross-Sectional Study

Authors: Goitom Molalign Takele, Tsegalem Hailemariam Ballo, Kiros Belay Gebrekidan, Birhan Gebresilassie Gebregiorgis

Abstract:

Background: Emergency medical services (EMS) are services that provide out-of-hospital emergency medical care to injured or ill peoples, and transporting to definitive care. EMS is an integral part of the emergency medical system and has been associated with decreased morbidity and mortality related to emergency cases. The aim of this study was to assess the utilization, barriers, and determinants of EMS in Mekelle, Ethiopia. Methods: A community-based cross-sectional study was conducted in selected sub-cities of Mekelle. A multistage sampling method was employed to recruit study participants, and data were collected by trained data collectors using an interviewer-administered questionnaire. Multivariate logistic regression analysis was used to examine the statistical association of the determinants of EMS utilization. Results: Half (50.5%) of the respondents had experienced or witnessed an emergency incident in the past year. The common means of transportations used were Bajaj’s (39.2%) and ambulances (22.7%). Majority (88.1%) of the respondents did not knew the EMS access phone number of an ambulance. As their preferred mode of transportation in case of emergency conditions, 42.2% of the participants reported an ambulance, followed by Bajaj 33.7%. Where participants who had gynecologic emergencies were 9.4 times (AOR=9.4, 95% CI: 1.04, 85, p=0.046), and those who knew any ambulance numbers were 3.6 times (AOR=3.6, 95% CI: 1.22, 10.8, p=0.02) more likely to use ambulance services in case of emergencies. Conclusion: The ambulance utilization level in Mekelle city was low and victims of emergency conditions were being transported mainly using public transports such as Bajaj’s and taxis. Even though the perception of the public towards EMS services is favorable, lack of awareness of EMS access, and lack of integrated EMS system in the city are the barriers that may have contributed to the low utilization. Actions to improve EMS access and integrating the system are warranted to promote the services utilization.

Keywords: emergency medical services, utilization, Mekelle, barriers

Procedia PDF Downloads 28
2 Queuing Analysis and Optimization of Public Vehicle Transport Stations: A Case of South West Ethiopia Region Vehicle Stations

Authors: Mequanint Birhan

Abstract:

Modern urban environments present a dynamically growing field where, notwithstanding shared goals, several mutually conflicting interests frequently collide. However, it has a big impact on the city's socioeconomic standing, waiting lines and queues are common occurrences. This results in extremely long lines for both vehicles and people on incongruous routes, service coagulation, customer murmuring, unhappiness, complaints, and looking for other options sometimes illegally. The root cause of this is corruption, which leads to traffic jams, stopping, and packing vehicles beyond their safe carrying capacity, and violating the human rights and freedoms of passengers. This study focused on the optimizing time of passengers had to wait in public vehicle stations. This applied research employed both data gathering sources and mixed approaches, then 166 samples of key informants of transport station were taken by using the Slovin sampling formula. The length of time vehicles, including the drivers and auxiliary drivers ‘Weyala', had to wait was also studied. To maximize the service level at vehicle stations, a queuing model was subsequently devised ‘Menaharya’. Time, cost, and quality encompass performance, scope, and suitability for the intended purposes. The minimal response time for passengers and vehicles queuing to reach their final destination at the stations of the Tepi, Mizan, and Bonga towns was determined. A new bus station system was modeled and simulated by Arena simulation software in the chosen study area. 84% improvement on cost reduced by 56.25%, time 4hr to 1.5hr, quality, safety and designed load performance calculations employed. Stakeholders are asked to put the model into practice and monitor the results obtained.

Keywords: Arena 14 automatic rockwell, queue, transport services, vehicle stations

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1 Magnitude of Visual Impairment and Associated Factors among Adult Glaucoma Patients Attending University of Gondar, Comprehensive Specialized Hospital, Tertiary Eye Care and Training Center, Northwest Ethiopia, 2022

Authors: Getenet Shumet Birhan, Biruk Lelisa Eticha, Gizachew Tilahun Belete, Fisseha Admassu Ayele

Abstract:

Context: Glaucoma is a significant public health concern globally, being the second leading cause of blindness. This study focuses on adult glaucoma patients in Ethiopia, specifically at the University of Gondar. Research Aim: The main objective is to assess the prevalence of visual impairment and identify associated factors among adult glaucoma patients at the University of Gondar. Methodology: The study used an institution-based cross-sectional design, collecting data from 423 glaucoma patients through interviews and medical chart reviews. Descriptive statistics and logistic regression were employed for analysis. Findings: The study found a high prevalence of visual impairment (77.6%) among adult glaucoma patients, with factors such as female sex, rural residence, glaucoma type, disease stage, and duration of diagnosis significantly associated with visual impairment. Theoretical Importance: This research adds valuable insights into the prevalence and determinants of visual impairment among glaucoma patients in Ethiopia, contributing to the existing literature on eye health in low-resource settings. Data Collection: Data were collected through face-to-face interviews and medical chart reviews at the University of Gondar, utilizing a structured questionnaire. Analysis Procedures: Descriptive statistics, frequency analysis, and binary logistic regression were employed to analyze the data and identify factors associated with visual impairment in adult glaucoma patients. Question Addressed: The study sought to answer the question of the prevalence of visual impairment and its associated factors among adult glaucoma patients at the University of Gondar in Northwest Ethiopia. Conclusion: The research concludes that visual impairment is significantly high among adult glaucoma patients in this setting, with several factors playing a role in its occurrence.

Keywords: visual impairment, glaucoma, Ethiopia, Gondar

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