Wright-Patterson Air Force Base

Leukemia cutis (LC) is a rare extramedullary manifestation of leukemia, most commonly associated with acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL). The classic clinical presentation of LC usually includes various cutaneous lesions such as papules, nodules, and plaques. There are limited case reports describing a primary presentation with hyperpigmented macules and patches. This case report describes a 29-year-old male, diagnosed with AML, who initially presented with extremity skin dyspigmentation, unexplained lymphadenopathy, and fatigue. A skin biopsy revealed a dense periadnexal and perivascular infiltrate of atypical blastoid cells. Special stains for melanin (Fontana Masson) and iron were negative for abnormal deposition. Immunohistochemical stains showed scattered immature leukocytes (myeloperoxidase-positive), CD4-positive cells consistent with flow cytometry, and weak CD56 staining of admixed cells within the dense infiltrates. The patient was diagnosed with AML with an 11q23 KMT2A::AFF1 gene rearrangement-a mutation increasingly associated with a poor prognosis. This case underscores the importance of recognizing hyperpigmentation as a rare but potential manifestation of LC, especially in younger patients, and highlights the need for prompt diagnosis and intervention to improve patient outcomes.

This commentary highlights the transformative journey of implementing a flipped, problem-based learning curriculum within an internal medicine residency program. Initially met with resistance from both faculty and residents accustomed to traditional lecture-based learning, the experience underscored the critical role of leadership in driving culture change. Despite the challenge, a comprehensive redesign, including 75 new PBL sessions and faculty development, yielded significant improvements: higher in-training exam scores and increased first-time board pass rates. The key takeaway emphasizes that successful curricular reform in graduate medical education requires a commitment to active learning, investment in faculty facilitation skills, and a data-driven approach to demonstrate positive outcomes. Shifting from lecture-based to active learning environments empowers learners and prepares them for self-directed learning and independent practice.

Transition metal (i.e., Mn, Fe, Cr) and chalcogen (Se) substituents are introduced into single-crystalline NiPS3, and the evolution of the two emergent quasi-particle excitations characteristic to the XXZ correlated antiferromagnetism of NiPS3 (i.e., spin orbit entangled exciton (SOX) and two-magnon scattering (2M)) are investigated as functions of substituent concentration through comprehensive room- and low-temperature photoluminescence (PL) and Raman spectroscopy studies. Thesefindings are further correlated with the magnetic properties of the same set of compounds reported in prior studies. The work revealed that the SOX emission intensities and linewidths are mainly controlled by the magnetic anisotropy and spin orientations, and are strongly suppressed by the introduction of substituents. The suppression depends on the type of substituent, with Fe affecting the SOX emission more than Mn and Cr. The 2m scattering is linked to short-range correlations and exhibits greater resiliency against metal atom substitution. While the 2M peak at low temperature gets suppressed and red-shifted in frequency with increasing concentrations of all the substituents, Fe induces the weakest suppression compared to all other substituents. Altogether, these findings revealed the introduction of substituents as a powerful route to control the emergent collective excitations in NiPS3 and mixed-MPX3 materials.

A uniform geometrical theory of diffraction (UTD) solution was developed earlier for radiation from sources on an analytically defined conducting convex surface. However, its application to meshed surfaces is challenging since it requires geodesic ray tracing and geometry based parameter extraction needed by UTD. The geodesic ray tracing algorithm, and the closed-form expressions and algorithms for geometry-based parameter extraction, which were developed previously for the UTD solution for mutual coupling, are modified accordingly for the application of the UTD solution for radiation to predict near and far fields from a source on a triangulated convex surface. Values for the geometry based parameters extracted from a triangulated circular cylinder and a triangulated sphere are compared with their actual values for validation. Although the proposed approach is applicable to triangulated arbitrary conducting convex surfaces, near and far field results obtained by applying the UTD solution to the analytically defined circular cylinder and sphere are respectively used to validate the results for the triangulated surfaces for these geometries. UTD is the only asymptotic method that includes creeping rays. Hence, the proposed approach is critically important for applications where creeping rays provide a significant contribution to fields radiated into or near shadow regions.

BackgroundX (formerly known as Twitter) is a social media platform with a robust online medical education community, including point-of-care ultrasound (POCUS) content.ObjectiveOur study aimed to determine if following curated POCUS education accounts on X translated to improved cardiac image interpretation competency.MethodsWe conducted an unblinded parallel-group randomized controlled trial at three internal medicine residency programs and two medical schools. Participants were third- and fourth-year medical students or internal medicine residents. They followed either 10 POCUS education accounts on X (T) or 10 generic medical accounts on X (C) for three months. Participants took a survey and a 15 multiple-choice question assessment before and after the protocol.ResultsTwenty-nine participants completed the protocol, 13 T and 16 C. Mean changes in image interpretation scores were T: -0.02% and C: +0.02%, which did not significantly differ (p = 0.46). A simple linear regression evaluating for correlation between average time spent on X and change in image interpretation scores among the T participants did not show a significant correlation (R squared – 0.0002, p = 0.96).ConclusionsNatural X exposure to educational POCUS accounts did not result in statistically improved image interpretation scores, but this outcome was likely affected by limited sample size, different participant experiences, and other variables. Data from this novel trial design can better inform future studies on medical education with social media.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12909-025-07385-3.

The gut microbiota influences brain function via the gut-brain axis, but the underlying molecular processes remain unclear. Critical to this communication are barrier systems, such as the epithelial gut and the blood-brain barrier, which mediate the interface between circulating signals and gut-brain communication. Microbial metabolites are key mediators of the gut microbiota that can influence barrier integrity. In this study, we used well-established in vitro models of the blood-brain and gut barriers and exposed them to a wide range of physiologically relevant stress-associated microbial metabolites, including tryptophan-derived metabolites with and without lipopolysaccharide (LPS) as a disrupting insult. We demonstrated that indole, indole-3-acetate, indole-3-propionate and tryptamine can modulate both gut and brain barriers in a dose- and cell-type dependent manner. Our findings suggest that specific indole metabolites should be further evaluated as promising novel therapeutic interventions to regulate barrier integrity along the microbiota-gut-brain axis.

The conceptual design of future high-Mach airframes relies upon constraints imposed by simplified feasibility and performance screening metrics. Reusable aircraft must safely land under all circumstances, including situations with engines inoperative. To identify designs that permit unpowered aircraft to operate in real-world runways, we developed a novel method optimizing kinematic performance, which a designer can use to discover emerging (statistical) relationships to predict landing feasibility. To land under “dead-stick” (unpowered) conditions with a low-L/Dmax aircraft, pilots cannot fly standard stabilized approaches to the threshold. Instead, these aircraft must arrest their sink rate through a dynamic maneuver initiated far in advance of the runway. This parametric study identifies design space regions where unpowered aircraft can land following generalized procedures. We also identify regions of the design space requiring specialized procedures as well as still others that simply cannot perform a safe landing.