The Experience of Non-Traditional Medical Students in the Clinical Setting

Purpose: To understand the experience of mature-aged medical students on clinical rotations. Background/Theoretical Framework: Although the mean age of first year medical students is 24, an increasing number of mature-aged students, defined as over age 30, are entering medical school. Most studies of mature-aged medical students have examined academic performance using quantitative research design. Few studies have employed qualitative methodology to determine the experience of mature-aged medical students, especially in the clinical setting. Methods: A recruitment e-mail was sent to all medical students enrolled in clinical rotations; first responders were interviewed until saturation in emerging themes was achieved. Interviews were conducted and recorded in a private office setting, then transcribed into a Word document. Five mature-aged students and four traditional students were interviewed. Using methodology for qualitative research described by Mustakas (1994), the investigators individually coded the transcripts to identify emerging themes. Coded themes underwent peer review, with triangulation of data collection, to determine main themes. Results: Three main themes emerged from our study. First, abundant life experience influences students perception of their role on clinical rotations. A mature student explained, ...having kids... being married and divorced... helps in connecting with patients. Previous work experience shapes expectations as a physician-in-training. While traditional students tend to be intimidated, mature students desire to take the initiative. Age plays a role in the students\u27 ability to relate to senior team members, as well as medical student colleagues. Traditional students note that mature students are more realistic due to their life experience in the workplace. Conclusion: Mature-aged students draw upon previous life experience, which shapes role expectations, as well as medical team dynamics. These differences may have implications in training the growing number of mature-aged medical students. A larger scale qualitative study including multiple medical school sites is being developed

Evaluation of surface properties of two remineralizing agents after modification by chitosan nano particles: An In vitro study

Background: Calcium phosphate-based systems have been introduced as promising bio-mimetic materials due to their close resemblance to the enamel. Chitosan and its derivatives have been an emerging biomaterial due to their additional antibacterial effect and promising re-mineralizing ability. Aim: The aim of this study is to evaluate the effect of chitosan nanoparticles on the remineralization of the demineralized enamel surface after being added to nano-hydroxyapatite and nano-calcium phosphate materials. Setting and Design: This was in vitro study. Materials and Methods: Twenty specimens of extracted permanent molars were collected, and then immersed in demineralizing solution, then distributed into four groups according to the remineralizing material. Group 1: Treated with Nano-beta-tricalcium phosphate (Nβ-TCP) gel, Group 2: Treated with Nβ-TCP with chitosan gel, Group 3: Treated with Nanohydroxyapatite (NHA) gel, and Group 4: Treated with NHA with chitosan gel. The surface hardness of the teeth was measured at baseline, after demineralization, and after remineralization. The structural changes in each group were analyzed using the scanning electron microscopy. Statistical Analysis: Shapiro–Wilk's test, one-way ANOVA followed by Tukey's post hoc test was used. Results: In all groups, there was a significant difference in mean Vickers hardness number (VHN) at different intervals, with the highest value found after treatment (301.64–395.65) VHN, followed by the baseline (236.97–276.15) VHN, while the lowest value was detected after demineralization (121.23–124.39) VHN. It was also indicated that baseline treatment, the Hardness percentage change (%) of the nano NHA + Chitosan group showed the highest significant value (55.10%), while the Nβ-TCP group exhibited the lowest significant value (9.56%). Conclusions: It can be concluded that NHA and NB-TCP modified by chitosan NPs as remineralizing agents of enamel surface hold promising results

\u3ci\u3eDrosophila\u3c/i\u3e Muller F Elements Maintain a Distinct Set of Genomic Properties Over 40 Million Years of Evolution

The Muller F element (4.2 Mb, ~80 protein-coding genes) is an unusual autosome of Drosophila melanogaster; it is mostly heterochromatic with a low recombination rate. To investigate how these properties impact the evolution of repeats and genes, we manually improved the sequence and annotated the genes on the D. erecta, D. mojavensis, and D. grimshawi F elements and euchromatic domains from the Muller D element. We find that F elements have greater transposon density (25–50%) than euchromatic reference regions (3–11%). Among the F elements, D. grimshawi has the lowest transposon density (particularly DINE-1: 2% vs. 11–27%). F element genes have larger coding spans, more coding exons, larger introns, and lower codon bias. Comparison of the Effective Number of Codons with the Codon Adaptation Index shows that, in contrast to the other species, codon bias in D. grimshawi F element genes can be attributed primarily to selection instead of mutational biases, suggesting that density and types of transposons affect the degree of local heterochromatin formation. F element genes have lower estimated DNA melting temperatures than D element genes, potentially facilitating transcription through heterochromatin. Most F element genes (~90%) have remained on that element, but the F element has smaller syntenic blocks than genome averages (3.4–3.6 vs. 8.4–8.8 genes per block), indicating greater rates of inversion despite lower rates of recombination. Overall, the F element has maintained characteristics that are distinct from other autosomes in the Drosophila lineage, illuminating the constraints imposed by a heterochromatic milieu