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Background: Cadaveric dissection is an essential practice for medical students to understand human anatomy and internalize professional attitudes toward death, such as empathy and respect for the deceased. Previous studies have focused on emotional responses such as shock, anxiety, and fear at the start of dissection practice. However, limited research exists on students' reflective thinking and perceptions before practice. This study aims is to understand premedical students' perceptions and attitudes before dissection by analyzing their reflective writing. Methods: Text network analysis of essays written in 2022 by 136 s-year premedical students before cadaveric dissection was performed. Keywords were preprocessed to extract significant themes. Centrality analysis and topic modeling were performed to analyze students' perceptions and attitudes. Results: Centrality analysis identified "cadaveric dissection," "donation," and "gratitude" as major keywords, indicating the students' deep appreciation and respect for donors. Two main topics emerged from topic modeling. The first, "gratitude and respect for donors," included keywords such as "gratitude" and "donation." The second, "growth and responsibility of doctors through medical study and practice," included keywords such as "study" and "medical school." Conclusion: The participants had profound gratitude and respect for donors before cadaveric dissection, which increased their motivation to learn. Analyzing reflective writing is an effective approach to understanding students' initial perceptions and attitudes toward cadaveric dissection; further, it can inform educational strategies that aid students in forming their professional identity. [ABSTRACT FROM AUTHOR]

The structure of a gate-controlled graphene/germanium hybrid photodetector was optimized by splitting the active region to achieve highly sensitive infrared detection capability. The strengthened internal electric field in the split active junctions enabled efficient collection of photocarriers, resulting in a responsivity of 2.02 A W−1 and a specific detectivity of 5.28 × 1010 Jones with reduced dark current and improved external quantum efficiency; these results are more than doubled compared with the responsivity of 0.85 A W−1 and detectivity of 1.69 × 1010 Jones for a single active junction device. The responsivity of the optimized structure is 1.7, 2.7, and 39 times higher than that of previously reported graphene/Ge with Al2O3 interfacial layer, gate-controlled graphene/Ge, and simple graphene/Ge heterostructure photodetectors, respectively.

Cellular dynamics and fate decision in early human embryogenesis remain largely unknown owing to the challenges of performing studies in human embryos.sup.1. Here, we explored whole-genomes of 334 single-cell colonies and targeted deep sequences of 379 bulk tissues obtained from various anatomical locations of seven recently deceased adult human donors. Using somatic mutations as an intrinsic barcode, we reconstructed early cellular phylogenies that demonstrate (1) an endogenous mutational rate that is higher in the first cell division but decreases to approximately one per cell per cell division later in life; (2) universal unequal contribution of early cells to embryo proper, resulting from early cellular bottlenecks that stochastically set aside epiblast cells within the embryo; (3) examples of varying degrees of early clonal imbalances between tissues on the left and right sides of the body, different germ layers and specific anatomical parts and organs; (4) emergence of a few ancestral cells that will substantially contribute to adult cell pools in blood and liver; and (5) presence of mitochondrial DNA heteroplasmy in the fertilized egg. Our approach also provides insights into the age-related mutational processes and loss of sex chromosomes in normal somatic cells. In sum, this study provides a foundation for future studies to complete cellular phylogenies in human embryogenesis. Adult human tissues from diverse sites around the body are used to reconstruct cellular phylogenies from early development, using somatic mutations as an internal barcode., Author(s): Seongyeol Park [sup.1] [sup.2] , Nanda Maya Mali [sup.3] , Ryul Kim [sup.1] , Jeong-Woo Choi [sup.3] [sup.4] , Junehawk Lee [sup.5] , Joonoh Lim [sup.1] , Jung Min [...]

The performance of a graphene/Ge Schottky junction near-infrared photodetector is significantly enhanced by inserting a thin Al2O3 interfacial layer between graphene and Ge. Dark current is reduced by two orders of magnitudes, and the specific detectivity is improved to 1.9 × 1010 cm ⋅ Hz1/2W−1. The responsivity is improved to 1.2 AW−1 with an interfacial layer from 0.5 AW−1 of the reference devices. The normalized photo-to-dark current ratio is improved to 4.3 × 107 W−1 at a wavelength of 1550 nm, which is 10–100 times higher than those of other Ge photodetectors.

Although there are a few studies of portions of the vestibular system such as the vestibulocerebellar tract and the neural connectivity of the vestibular nuclei (VN), no study of the ipsilateral vestibulothalamic tract (VTT) (originating from the VN and mainly connecting to the lateral thalami nuclei) has been reported. In the current study, using diffusion tensor tractography (DTT), we investigate the reconstruction method and characteristics of the ipsilateral VTT in normal subjects. Thirty-three subjects were recruited for this study. For the ipsilateral VTT, the seed region of interest (ROI) was placed on the VN, which was isolated on the FA map using adjacent structures as follows: the reticular formation (anterior boundary), posterior margin of medulla and pons (posterior boundary), medial lemniscus (medial boundary) and restiform body (lateral boundary). The target ROI was placed at the lateral thalamic nuclei using known anatomical locations. The DTT parameters of the ipsilateral VTT were measured. The ipsilateral VTTs that originated from the vestibular nuclei ascended postero-laterally to the upper pons and antero-medially to the upper midbrain via the medial longitudinal fasciculus, and terminated the lateral thalamic nuclei. No significant differences were observed in DTT parameters of the ipsilateral VTT between the right and left hemispheres (p > 0.05). Using DTT, we reconstructed the ipsilateral VTT and observed the anatomical characteristics of the ipsilateral VTT in normal subjects. We believe that the methodology and results in this study could be helpful to researchers and clinicians in this field.