AUS Repository
The AUS Repository serves as the Institutional Repository of the American University of Sharjah, providing open access to research outputs from AUS students and faculty. By preserving these works for the long term and increasing their global visibility, the repository plays a key role in the dissemination of knowledge. See our About Us page for more information.
Featured Items
Recent Submissions
Item Characterization of Contusive Spinal Cord Injury by Monitoring Motor-Evoked Potential(MDPI, 2024-11-07)This study involves longitudinal neuro-electrophysiological analysis using motor-evoked potentials (MEP) and the Basso, Beattie, and Bresnahan behavioral examinations (BBB) to evaluate moderate mid-thoracic contusive spinal cord injury (SCI) in a rat model. Objectives/Background: The objective of the study is to characterize the onset and progression of contusive SCI over an eight-week period using a clinically applicable tool in an in vivo model. The background highlights the importance of a reliable and reproducible injury model and assessment tools for SCI. Methods: The methods section describes the experimental setup, including randomly assigned rats in three groups: Sham, Control, and Injury (undergoing a moderate contusive SCI using the NYU-Impactor). MEP monitoring and BBB examinations are conducted at baseline and weekly for eight weeks post-injury. Results: The results indicate that the relative MEP power spectral decreased to 11% and 22% in the left and right hindlimbs, respectively, during the first week post-SCI. In the second week, a slight spontaneous recovery was observed, reaching 17% in the left and 31% in the right hindlimbs. Over the following four weeks post-SCI, continuing deterioration of MEP signal power was observed with no detectable recovery. Conclusions: SCI attenuates hindlimb MEP power spectral and reduces locomotion, though the changes in MEP and locomotion exhibit distinct temporal patterns. The MEP monitoring provides valuable insights into the functional integrity of motor pathways following SCI and offer a sensitive and reliable assessment. By implementing MEP monitoring, researchers can track the progression of SCI and evaluate the efficacy of therapeutic interventions quantitatively.Item Hypothermia effects on neuronal plasticity post spinal cord injury(PLoS ONE, 2024-04-05)Background SCI is a time-sensitive debilitating neurological condition without treatment options. Although the central nervous system is not programmed for effective endogenous repairs or regeneration, neuroplasticity partially compensates for the dysfunction consequences of SCI. Objective and hypothesis The purpose of our study is to investigate whether early induction of hypothermia impacts neuronal tissue compensatory mechanisms. Our hypothesis is that although neuroplasticity happens within the neuropathways, both above (forelimbs) and below (hindlimbs) the site of spinal cord injury (SCI), hypothermia further influences the upper limbs’ SSEP signals, even when the SCI is mid-thoracic. Study design A total of 30 male and female adult rats are randomly assigned to four groups (n = 7): sham group, control group undergoing only laminectomy, injury group with normothermia (37°C), and injury group with hypothermia (32°C +/-0.5°C). Methods The NYU-Impactor is used to induce mid-thoracic (T8) moderate (12.5 mm) midline contusive injury in rats. Somatosensory evoked potential (SSEP) is an objective and non-invasive procedure to assess the functionality of selective neuropathways. SSEP monitoring of baseline, and on days 4 and 7 post-SCI are performed. Results Statistical analysis shows that there are significant differences between the SSEP signal amplitudes recorded when stimulating either forelimb in the group of rats with normothermia compared to the rats treated with 2h of hypothermia on day 4 (left forelimb, p = 0.0417 and right forelimb, p = 0.0012) and on day 7 (left forelimb, p = 0.0332 and right forelimb, p = 0.0133) post-SCI. Conclusion Our results show that the forelimbs SSEP signals from the two groups of injuries with and without hypothermia have statistically significant differences on days 4 and 7. This indicates the neuroprotective effect of early hypothermia and its influences on stimulating further the neuroplasticity within the upper limbs neural network post-SCI. Timely detection of neuroplasticity and identifying the endogenous and exogenous factors have clinical applications in planning a more effective rehabilitation and functional electrical stimulation (FES) interventions in SCI patients.Item A Hybrid Transfer Learning Approach to Teeth Diagnosis Using Orthopantomogram Radiographs(IEEE, 2024-11-28)The rise in the emphasis on oral diseases has elevated the need to automate the diagnostic process of such diseases. Fortunately, the availability of modern computing devices has made the automated diagnosis of teeth readily possible using deep learning. Despite this, concerns about the accuracy and function of automated diagnosis remain among patients. To showcase the performance of such algorithms, we propose two approaches for the task of teeth diagnosis utilizing Orthopantomograms (panoramic radiographs): 1) a direct classification approach; and 2) a hybrid approach that combines a deep learning model with a traditional classifier. The results revealed that all ten chosen deep learning models experienced a similar or improved performance when used in conjunction with a machine learning classifier. In particular, Vision Transformer (ViT) performed the best with a record accuracy of 96% using both the direct and hybrid approaches. However, the hybrid framework combining AlexNet with a Support Vector Machine achieved an accuracy of 94%, and although it falls short of ViT in terms of performance, it comprises far fewer parameters. This highlights the approach’s effectiveness in improving performance without the need to use a deeper model, making it well-suited for clinical adoption where efficiency is important.Item Drug Release via Ultrasound-Activated Nanocarriers for Cancer Treatment: A Review(MDPI, 2024-10-27)Conventional cancer chemotherapy often struggles with safely and effectively delivering anticancer therapeutics to target tissues, frequently leading to dose-limiting toxicity and suboptimal therapeutic outcomes. This has created a need for novel therapies that offer greater efficacy, enhanced safety, and improved toxicological profiles. Nanocarriers are nanosized particles specifically designed to enhance the selectivity and effectiveness of chemotherapy drugs while reducing their toxicity. A subset of drug delivery systems utilizes stimuli-responsive nanocarriers, which enable on-demand drug release, prevent premature release, and offer spatial and temporal control over drug delivery. These stimuli can be internal (such as pH and enzymes) or external (such as ultrasound, magnetic fields, and light). This review focuses on the mechanics of ultrasound-induced drug delivery and the various nanocarriers used in conjunction with ultrasound. It will also provide a comprehensive overview of key aspects related to ultrasound-induced drug delivery, including ultrasound parameters and the biological effects of ultrasound waves.Item Antimicrobial Activity of Novel Deep Eutectic Solvents(MDPI, 2023-02-08)Herein, we utilized several deep eutectic solvents (DES) that were based on hydrogen donors and hydrogen acceptors for their antibacterial application. These DES were tested for their bactericidal activities against Gram-positive (Streptococcus pyogenes, Bacillus cereus, Streptococcus pneumoniae, and methicillin-resistant Staphylococcus aureus) and Gram-negative (Escherichia coli K1, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Serratia marcescens) bacteria. Using lactate dehydrogenase assays, DES were evaluated for their cytopathic effects towards human cells. Results from antibacterial tests revealed that DES prepared from the combination of methyl-trioctylammonium chloride and glycerol (DES-4) and DES prepared form methyl-trioctylammonium chloride and fructose (DES-11) at a 2 µL dose showed broad-spectrum antibacterial behavior and had the highest bactericidal activity. Moreover, DES-4 showed 40% and 68% antibacterial activity against P. aeruginosa and E. coli K1, respectively. Similarly, DES-11 eliminated 65% and 61% E. coli K1 and P. aeruginosa, respectively. Among Gram-positive bacteria, DES-4 showed important antibacterial activity, inhibiting 75% of B. cereus and 51% of S. pneumoniae. Likewise, DES-11 depicted 70% B. cereus and 50% S. pneumoniae bactericidal effects. Finally, the DES showed limited cytotoxic properties against human cell lines with the exception of the DES prepared from Methyltrioctylammonium chloride and Citric acid (DES-10), which had 88% cytotoxic effects. These findings suggest that DES depict potent antibacterial efficacies and cause minimal damage to human cells. It can be concluded that the selected DES in this study could be utilized as valuable and novel antibacterial drugs against bacterial infections. In future work, the mechanisms for bactericides and the cytotoxicity effects of these DES will be investigated.
Communities in AUS Repository
Select a community to browse its collections.