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Background: Joint access is essential for arthrocentesis, or joint aspiration of fluids. Joint treatments that are not performed properly can result in avoidable patient issues such as damage to the muscles, tendons, and blood vessels surrounding the joint. The use of ultrasound has become the gold standard for this procedure and proven to be a support in the skill learning process. However, success with this equipment, particularly in small joints like the wrist, depends on a clinician's capacity to recognize the crucial landmarks that guide these procedures. Prior to executing on a real patient, task trainers have proven to be an effective way for doctors to practice and prepare for procedures. However, shortcomings of current solutions include high purchase costs, incompatibility with ultrasound imaging, and low reusability. In addition, since this is a procedure that is not performed frequently, there may not be space or resources available in healthcare facilities to accommodate one at the point of care. This study aimed to close the existing gap by developing a DIY ultrasound compatible task trainer for wrist joint access training. Results: We developed a novel ultrasound compatible wrist joint model that can be made from sustainable materials and reusable parts, thus reducing the costs for acquisition and environmental impact. Our model, which was produced utilizing small-batch production methods, is made up of 3D-printed bones enclosed in an ultrasound-compatible gelatin mixture. It can be easily remade after each practice session, removing needle tracks that are visible under ultrasound for conventional phantoms. The ultrasonic properties of this model were tested through pixel brightness analysis and visual inspection of simulated anatomical structures. Conclusion: Our results report the advantages and limitations of the proposed model regarding production, practice, and ultrasound compatibility. While future work entails the transfer to patients of the same skill, this reusable and replicable model has proven, when presented to experts, to be successful in representing the physical characteristics and ultrasound profile of significant anatomical structures. This novel DIY product could be an effective alternative to teach procedures in the context of resource-restrained clinical simulation centers. [ABSTRACT FROM AUTHOR]

The blood–brain barrier (BBB) plays a pivotal role in brain health and disease. In the BBB, brain microvascular endothelial cells (BMECs) are connected by tight junctions which regulate paracellular transport, and express specialized transporter systems which regulate transcellular transport. However, existing in vitro models of the BBB display variable accuracy across a wide range of characteristics including gene/protein expression and barrier function. Here, we use an isogenic family of fluorescently-labeled iPSC-derived BMEC-like cells (iBMECs) and brain pericyte-like cells (iPCs) within two-dimensional confluent monolayers (2D) and three-dimensional (3D) tissue-engineered microvessels to explore how 3D microenvironment regulates gene expression and function of the in vitro BBB. We show that 3D microenvironment (shear stress, cell-ECM interactions, and cylindrical geometry) increases BBB phenotype and endothelial identity, and alters angiogenic and cytokine responses in synergy with pericyte co-culture. Tissue-engineered microvessels incorporating junction-labeled iBMECs enable study of the real-time dynamics of tight junctions during homeostasis and in response to physical and chemical perturbations. [ABSTRACT FROM AUTHOR]

The blood–brain barrier (BBB) plays a pivotal role in brain health and disease. In the BBB, brain microvascular endothelial cells (BMECs) are connected by tight junctions which regulate paracellular transport, and express specialized transporter systems which regulate transcellular transport. However, existing in vitro models of the BBB display variable accuracy across a wide range of characteristics including gene/protein expression and barrier function. Here, we use an isogenic family of fluorescently-labeled iPSC-derived BMEC-like cells (iBMECs) and brain pericyte-like cells (iPCs) within two-dimensional confluent monolayers (2D) and three-dimensional (3D) tissue-engineered microvessels to explore how 3D microenvironment regulates gene expression and function of the in vitro BBB. We show that 3D microenvironment (shear stress, cell-ECM interactions, and cylindrical geometry) increases BBB phenotype and endothelial identity, and alters angiogenic and cytokine responses in synergy with pericyte co-culture. Tissue-engineered microvessels incorporating junction-labeled iBMECs enable study of the real-time dynamics of tight junctions during homeostasis and in response to physical and chemical perturbations. [ABSTRACT FROM AUTHOR]

2D semiconductors are attractive candidates for on‐chip electro‐optic modulators due to their ease of integration and rich exciton‐mediated phenomena. While electrostatic doping and out‐of‐plane field effect have been extensively studied, in‐plane field‐induced phenomena remain largely unexplored. Here electro‐optic response of monolayer WSe2 subject to modulating in‐plane electric fields probed by electroabsorption and electroreflectance spectroscopy is reported. The devices are found to exhibit spatially varying response near exciton resonance, which cannot be explained by predicted effects such as Pockels and excitonic Stark effect. It is shown that the modulation signal is dominated by exciton linewidth broadening and narrowing associated with local accumulation and depletion of free holes. The field and frequency dependence of the devices is distinct from those of charge modulation devices. The observed behavior is ascribed to elastic scattering of excitons with field‐driven intrinsic free carriers. [ABSTRACT FROM AUTHOR]

The effective integration of 2D materials such as monolayer transition metal dichalcogenides (TMDs) into photonic waveguides and integrated circuits is being intensely pursued due to these materials' strong exciton‐based optical response. This work presents a platform where a 2D heterostructure (WS2‐hBN) is directly integrated into the photonic mode‐center of a novel polymer ridge waveguide. Finite‐difference time‐domain simulations and collection of photoluminescence from the guided mode indicate that this system exhibits significantly improved waveguide‐emitter coupling and mode confinement over a previous elastomer platform. This is facilitated by the platform's enhanced refractive‐index contrast and a new method for mode‐center integration of the coupled TMD. The integration is based on a simple dry‐transfer process that is applicable to other 2D materials, and the platform's elastomeric nature is a natural fit to explore strain‐tunable hybrid‐photonic devices. The demonstrated ability of coupling photoluminescence to a polymer waveguide opens up new possibilities for hybrid‐photonic systems in a variety of contexts. [ABSTRACT FROM AUTHOR]