Almanac: Retrieval-Augmented Language Models for Clinical Medicine

Large-language models have recently demonstrated impressive zero-shot capabilities in a variety of natural language tasks such as summarization, dialogue generation, and question-answering. Despite many promising applications in clinical medicine, adoption of these models in real-world settings has been largely limited by their tendency to generate incorrect and sometimes even toxic statements. In this study, we develop Almanac, a large language model framework augmented with retrieval capabilities for medical guideline and treatment recommendations. Performance on a novel dataset of clinical scenarios (n = 130) evaluated by a panel of 5 board-certified and resident physicians demonstrates significant increases in factuality (mean of 18% at p-value < 0.05) across all specialties, with improvements in completeness and safety. Our results demonstrate the potential for large language models to be effective tools in the clinical decision-making process, while also emphasizing the importance of careful testing and deployment to mitigate their shortcomings

Estimation of Mechanical and Thermal Properties of Porous Aluminosilicate Foam

Aluminosilicates are naturally occurring minerals with low thermal conductivity due to the presence of variable size pores in their structure. Because they are found in abundance in nature, they could be an economical alternative for the fabrication of thermal insulators used in the buildings and underground mines. In this study, the thermal and mechanical properties of amorphous porous aluminosilicate structures (PAS) were investigated using computational and experimental methods. Molecular Dynamics (MD) simulation was used to characterize the thermal conductivity at the atomistic scale. MD simulations were performed to identify the suitable Al-Si ratio that yields the lowest possible thermal conductivity as well as high mechanical strength. The effect of density on the thermal conductivity of aluminosilicate structures was characterized. It was observed that the thermal conductivity of the Aluminosilicate structures has a linear dependence on the densities varying between 0.4 g/cc and 2.62 g/cc. In addition, for a given porosity, a larger distribution of smaller pores results in lower thermal conductivity. This observation is correlated with the presence of phonon-scattering centers in such systems. The data obtained from MD simulations were used to physically fabricate the foams with similar densities in laboratory, and their associated thermal conductivity was experimentally measured. MD simulations and experimental data show a high degree of agreement. The ultrasound non-destructive technique (NDT) was used to transmit wave energy in the 1 MHz frequency range to measure dynamic mechanical properties experimentally. Porosity was varied by changing the composition of the blowing agent and surfactant. P-wave and S-wave velocities were measured using the time of flight of the ultrasonic energy through the sample. The Finite Element Method (FEM) provided in the COMSOL Multiphysics platform was used to verify the bulk mechanical and thermal properties of the amorphous porous aluminosilicate materials. Acoustic and stress analysis were performed at different porosities to determine P-wave and S-wave velocities, and other elastic properties. Symmetric spherical pores were introduced to simulate porosity. We also generated a high-fidelity model of the foam using micro-CT scans. Volume meshing was created in the Simpleware ScanIp software and subsequently exported as a COMSOL supported file to perform the modeling. Next, FEM models were set up to determine the acoustic and elastic properties at different porosity ranges. The data produced in this analysis demonstrated a good agreement between numerical and experimental tests. The findings from this research project will be used to design and fabricate a cost-effective thermal insulator

Formulation and evaluation of polyherbal anti-diabetic tablet for oral drug delivery system

The Present Investigation was aimed to develop a Polyherbal tablet formulation for effective treatment of diabetes mellitus. Polyherbal tablets containing various Herbal extracts were prepared using different super disintegrants in varying concentrations to achieve minimum disintegration time. Pre-compression Parameters for all blends were within acceptable range of pharmacopoeial specifications. Formulation F4 showed minimum disintegration time of 14.20 minutes. Hence, it was selected as an optimised formulation and subjected to stability study. Stability study results revealed that, formulation F4 was a stable formulation having better disintegration time and % friability and could be used for effective treatment of diabetes mellitus

Portable, non-invasive video imaging of retinal blood flow dynamics

Retinal blood flow (RBF) information has the potential to offer insight into ophthalmic health and disease that is complementary to traditional anatomical biomarkers as well as to retinal perfusion information provided by fluorescence or optical coherence tomography angiography (OCT-A). The present study was performed to test the functional attributes and performance of the XyCAM RI, a non-invasive imager that obtains and assesses RBF information. The XyCAM RI was installed and used in two different settings to obtain video recordings of the blood flow in the optic nerve head region in eyes of healthy subjects. The mean blood flow velocity index (BFVi) in the optic disc and in each of multiple arterial and venous segments was obtained and shown to reveal a temporal waveform with a peak and trough that correlates with a cardiac cycle as revealed by a reference pulse oximeter (correlation between respective peak-to-peak distances was 0.977). The intra-session repeatability of the XyCAM RI was high with a coefficient of variation (CV) of 1.84 ± 1.13% across both sites. Artery-vein comparisons were made by estimating, in a pair of adjacent arterial and venous segments, various temporal waveform metrics such as pulsatility index, percent time in systole and diastole, and change in vascular blood volume over a cardiac cycle. All arterial metrics were shown to have significant differences with venous metrics (p < 0.001). The XyCAM RI, therefore, by obtaining repeatable blood flow measurements with high temporal resolution, permits the differential assessment of arterial and venous blood flow patterns in the retina that may facilitate research into disease pathophysiology and biomarker development for diagnostics

Viability of preloaded Descemet membrane endothelial keratoplasty grafts with 96-hour shipment

Objective To assess feasibility and compare the effects of 96-hour shipment of Descemet membrane endothelial keratoplasty (DMEK) grafts as a scroll or a tri-fold on cell viability.Methods and analysis DMEK grafts were prepared at the Rocky Mountain Lions Eye Bank. Twenty pre-stripped DMEK grafts, paired from 10 donors, were either tri-folded in an endothelium-in configuration using microforceps and loaded into a plastic Treyetech cartridge, or suctioned in a scrolled endothelium-out configuration into a modified Jones Tube. Grafts were shipped via FedEx to a secondary location and back for 48 hours each way, resulting in a total shipping time of 96 hours. After shipping, grafts were removed from inserters onto glass slides and unfolded using viscoelastic with endothelium facing upwards. Calcein-AM stained grafts were imaged with a fluorescent microscope and endothelial cell loss (ECL) was measured using trainable segmentation in Fiji by a masked grader.Results A total of 20 grafts were shipped for 96 hours, split between preloaded tri-folded (n=10) and preloaded scrolled (n=10) tissues. No significant difference in ECL was observed across groups after prolonged shipping (14.8% vs 13.7% ECL respectively, p=0.68).Conclusion For preloaded DMEK after 96 hours, both scrolled and tri-folded tissue demonstrated clinically acceptable levels of ECL. The data suggest a wider window of time for endothelial cell viability and is promising for the prospect of international shipment of preloaded grafts