Anatomy: The Relationship Between Internal and External Visualizations

This dissertation explored the relationship between internal and external visualizations and the implications of this relationship for comprehending visuospatial anatomical information. External visualizations comprised different computer representations of anatomical structures, including: static, animated, non-interactive, interactive, non-stereoscopic, and stereoscopic visualizations. Internal visualizations involved examining participants’ ability to apprehend, encode, and manipulate mental representations (i.e., spatial visualization ability or Vz). Comprehension was measured with a novel spatial anatomy task that involved mental manipulation of anatomical structures in three-dimensions and two-dimensional cross-sections. It was hypothesized that performance on the spatial anatomy task would involve a trade-off between internal and external visualizations available to the learner. Results from experiments 1, 2, and 3 demonstrated that in the absence of computer visualizations, spatial visualization ability (Vz) was the main contributor to variation in spatial anatomy task performance. Subjects with high Vz scored higher, spent less time, and were more accurate than those with low Vz. In the presence of external computer visualizations, variation in task performance was attributed to both Vz and visuospatial characteristics of the computer visualization. While static representations improved performance of high- and low-Vz subjects equally, animations particularly benefited high Vz subjects, as their mean score on the SAT was significantly higher than the mean score of low Vz subjects. The addition of interactivity and stereopsis to the displays offered no additional advantages over non-interactive and non-stereoscopic visualizations. Interactive, non-interactive, stereoscopic and non-stereoscopic visualizations improved the performance of high- and low-Vz subjects equally. It was concluded that comprehension of visuospatial anatomical information involved a trade-off between the perception of external visualizations and the ability to maintain and manipulate internal visualizations. There is an inherent belief that increasing the educational effectiveness of computer visualizations is a mere question of making them dynamic, interactive, and/or realistic. However, experiments 1, 2, and 3 clearly demonstrate that this is not the case, and that the benefits of computer visualizations vary according to learner characteristics, particularly spatial visualization ability

QUANTITATIVE DETERMINATION AND PREPARATIVE ISOLATION OF TWO MAJOR ALKALOIDS FROM THE VIETNAMESE MEDICINAL HERB EVODIAE FRUCTUS

Objective: To develop a simple and accurate HPLC-DAD method for simultaneous determination, the content of major components: limonin, evodiamine, and rutaecarpine in Evodiae fructus and evaluation the quality of Evodiae fructus sold in markets. Methods: Open column chromatography was used to separate and purify rutaecarpine and evodiamine, the two major alkaloids from Evodiae fructus extract as a laboratory standard. Chromatographic separation was achieved using a Germini C18 column (150 mm × 4.6 mm I.D., 5 µm), detected at 210 nm. The mobile phase consisted of acetonitrile (A), methanol (B), and water (C). The validated method simultaneously determined alkaloid content in 40 batches of samples collected from markets in different regions of Vietnam. Results: In one-step purification, our method yielded 326 mg of rutaecarpine and 128 mg of evodiamine from 3.2 g of crude extract, with purities of 98.9 and 98.5%, respectively. The structures of these compounds were identified using 1H NMR and 13C NMR. There was a significant correlation between alkaloid content and fruit size, with a Spearman correlation coefficient of>0.5 (p<0.001), and there was a large difference in alkaloid contents between three maturity degrees of the fruit. Open-mouth fruits and fruits with average sizes of 4 to 6 mm had the highest alkaloid contents, whereas closed-mouth fruits had the lowest. Conclusion: This study provided information on the standardization and quality control of evodiamine and rutaecarpine in Evodiae fructus, as well as a foundation for further pharmacological and toxicological studies

Synthesis and Characterization of β-Cyclodextrin/alginate Nanoparticle as a Novel Drug Delivery System

The aim of this work was to study a novel nanoparticle system formed from alginate and β-cyclodextrin by ionotropic gelation method and to evaluate their potential for the association and delivery of drugs. The nanoparticles were prepared by electrostatic interactions between Ca2+/alginate gel and β-cyclodextrin. Morphology and structure characterization of nanoparticles was investigated by scanning electron micrographs (SEM), transmission electron microscope (TEM), Fourier transform infrared spectra (FTIR). The nanoparticle size was about 50 – 80 nm and their structure quite regular and consistent. Ketoprofen, chosen as a model drug, was incorporated into the nanocarriers with association efficiency of 50.7 % and loading efficiency of 5.7 %. Ketoprofen released from the nanoparticles was 57 % at pH 7.4 and 69 % at pH 5.0 for 4 h

Development of Diagnostic Tests for Detection of SARS-CoV-2

One of the most effective ways to prevent the spread of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is to develop accurate and rapid diagnostic tests. There are a number of molecular, serological, and imaging methods that are used to diagnose this infection in hospitals and clinical settings. The purpose of this review paper is to present the available approaches for detecting SARS-CoV-2 and address the advantages and limitations of each detection method. This work includes studies from recent literature publications along with information from the manufacturer\u27s manuals of commercially available SARS-CoV-2 diagnostic products. Furthermore, supplementary information from the Food and Drug Administration (FDA), Centers for Disease Control and Prevention (CDC), and World Health Organization (WHO) is cited. The viral components targeted for virus detection, the principles of each diagnostic technique, and the detection efficiency of each approach are discussed. The potential of using diagnostic tests that were originally developed for previous epidemic viruses is also presented