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Abstract Background Traditionally, ultrasound skills have been taught through a one-on-one approach, where instructors physically guide learners’ hands at the bedside or in the workshop. However, this method is frequently challenged by scheduling and cost limitations. Our objective was to create a tele-education model for point-of-care ultrasound training and evaluate its effectiveness and its impact on learners’ perceived workload compared to conventional education and self-directed learning methods. Methods We conducted a 3-arm randomized trial, comparing tele-education (TE), conventional education (CE) and self-directed learning (SL) methods. All subjects underwent online didactic lectures prior to a hands-on ultrasound workshop. The TE group utilized an ultrasound machine equipped with a speakerphone, a webcam for direct visualization of learner’s hand maneuvers, and an analog-to-video converter for the real-time streaming of ultrasound images. This configuration enabled remote instructors to provide immediate verbal feedback to learners. In contrast, the CE group received in-person coaching, while the SL group had no instructors present. Following the coaching session, subjects completed a scenario-based skill test and a survey on the National Aeronautics and Space Administration task load index (NASA-TLX) to measure their ultrasound competency and perceived workload, respectively. Results Twenty-seven ultrasound novices were randomly allocated into 3 groups. The median skill test score of TE, CE, and SL was 22 [interquartile range (IQR): 18–28], 24 [IQR: 21–31], and 16 [IQR: 15–18], respectively (p

Single-molecule intramolecular dynamics were successfully measured for three variants of SARS-CoV-2 spike protein, alpha: B.1.1.7, delta: B.1.617, and omicron: B.1.1.529, with a time resolution of 100 μs using X-rays. The results were then compared with respect to the magnitude and directions of motions for the three variants. The largest 3-D intramolecular movement was observed for the omicron variant irrespective of ACE2 receptor binding. A more detailed analysis of the intramolecular motions revealed that the distribution state of intramolecular motion for the three variants was completely different with and without ACE2 receptor binding. The molecular dynamics for the trimeric spike protein of the omicron variant increased when ACE2 binding occurred. At that time, the diffusion constant increased from 71.0 [mrad2/ms] to 91.1 [mrad2/ms].

Abstract Iron-sulfur clusters are prosthetic groups of proteins involved in various biological processes. However, details of the immature state of the iron-sulfur cluster into proteins have not yet been elucidated. We report here the first structural analysis of the Zn-containing form of a Rieske-type iron-sulfur protein, PetA, from Thermochromatium tepidum (TtPetA) by X-ray crystallography and small-angle X-ray scattering analysis. The Zn-containing form of TtPetA was indicated to be a dimer in solution. The zinc ion adopts a regular tetra-coordination with two chloride ions and two cysteine residues. Only a histidine residue in the cluster-binding site exhibited a conformational difference from the [2Fe-2S] containing form. The Zn-containing structure indicates that the conformation of the cluster binding site is already constructed and stabilized before insertion of [2Fe-2S]. The binding mode of ZnCl2, similar to the [2Fe-2S] cluster, suggests that the zinc ions might be involved in the insertion of the [2Fe-2S] cluster.

We develop a method for calculating the minimum X-ray exposure time for X-ray solution scattering experiments using statistical and mathematical approaches to enhance the measurement efficiency while maintaining data quality. Experts can determine the X-ray exposure time for samples by investigating time-series data of scattering profiles and considering the quality of scattering profiles and the samples’ X-ray damage. In this study, we apply a statistical inequality to estimate the kernel density estimation method’s error to determine the minimum X-ray exposure time for protein solution scattering experiments and evaluate the method’s validity using the results of Guinier analysis as an indicator.

Abstract The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete Fourier transforms due to their high computational efficiency. However, the mathematics underpinning these algorithms is typically formulated using continuous mathematics, which can result in a loss of spatial resolution in the reconstructed images. Herein we investigate how phase retrieval algorithms for propagation-based phase-contrast X-ray imaging can be rederived using discrete mathematics and result in more precise retrieval for single- and multi-material objects and for spectral image decomposition. We validate this theory through experimental measurements of spatial resolution using computed tomography (CT) reconstructions of plastic phantoms and biological tissues, using detectors with a range of imaging system point spread functions (PSFs). We demonstrate that if the PSF substantially suppresses high spatial frequencies, the potential improvement from utilising the discrete derivation is limited. However, with detectors characterised by a single pixel PSF (e.g. direct, photon-counting X-ray detectors), a significant improvement in spatial resolution can be obtained, demonstrated here at up to 17%.

Abstract Background Critical care ultrasonography (CCUS) has become a daily diagnostic tool for intensivists. While the effective training measures for ultrasound novices are discussed widely, the best curriculum for the novices to retain a long-term proficiency is yet to be determined. Methods Critical care medicine fellows who underwent an introductory CCUS workshop were randomly allocated into the standard training (ST) or the intensive training (IT) group. The IT group received an 8-h training besides the standardized fellowship education that the ST group received. Participant improvement in CCUS proficiency tests (maximum score, 200) after a 6-month training intervention was compared between the groups. CCUS examinations performed in patient care were observed over 2 years. Results Twenty-one fellows were allocated into the ST (n = 10) or the IT (n = 11) group. No statistically significant difference was observed in the median (interquartile range [IQR]) improvement in CCUS proficiency tests between the ST group and the IT group: 18 (3.8–38) versus 31 (21–46) (P = .09). Median (IQR) test scores were significantly higher in postintervention than preintervention for both groups: ST, 103 (87–116) versus 124 (111–143) (P = .02), and IT, 100 (87–113) versus 143 (121–149) (P

BackgroundThe Surviving Sepsis Campaign suggested preferential resuscitation with balanced crystalloids, such as Lactated Ringer’s (LR), although the level of recommendation was weak, and the quality of evidence was low. Past studies reported an association of unbalanced solutions, such as normal saline (NS), with increased AKI risks, metabolic acidosis, and prolonged ICU stay, although some of the findings are conflicting. We have compared the outcomes with the preferential use of normal saline vs. ringer’s lactate in a cohort of sepsis patients.MethodWe performed a retrospective cohort analysis of patients visiting the ED of 19 different Mayo Clinic sites between August 2018 to November 2020 with sepsis and receiving at least 30 mL/kg fluid in the first 6 h. Patients were divided into two cohorts based on the type of resuscitation fluid (LR vs. NS) and propensity-matching was done based on clinical characteristics as well as fluid amount (with 5 ml/kg). Single variable logistic regression (categorical outcomes) and Cox proportional hazards regression models were used to compare the primary and secondary outcomes between the 2 groups.ResultsOut of 2022 patients meeting our inclusion criteria; 1,428 (70.6%) received NS, and 594 (29.4%) received LR as the predominant fluid (>30 mL/kg). Patients receiving predominantly NS were more likely to be male and older in age. The LR cohort had a higher BMI, lactate level and incidence of septic shock. Propensity-matched analysis did not show a difference in 30-day and in-hospital mortality rate, mechanical ventilation, oxygen therapy, or CRRT requirement. We did observe longer hospital LOS in the LR group (median 5 vs. 4 days, p = 0.047 and higher requirement for ICU post-admission (OR: 0.70; 95% CI: 0.51–0.96; p = 0.026) in the NS group. However, these did not remain statistically significant after adjustment for multiple testing.ConclusionIn our matched cohort, we did not show any statistically significant difference in mortality rates, hospital LOS, ICU admission after diagnosis, mechanical ventilation, oxygen therapy and RRT between sepsis patients receiving lactated ringers and normal saline as predominant resuscitation fluid. Further large-scale prospective studies are needed to solidify the current guidelines on the use of balanced crystalloids.

Abstract Acoustic levitation has attracted attention in terms of chemical and biochemical analysis in combination with various analytical methods because of its unique container-less environment for samples that is not reliant on specific material characteristics. However, loading samples with very high viscosity is difficult. To expand the scope, we propose the use of polymer thin films as sample holders, whereby the sample is dispensed on a film that is subsequently loaded onto an acoustic levitator. When applied for protein crystallography experiments, rotation controllability and positional stability are important prerequisites. We therefore study the acoustic levitation and rotation of thin films with an aspect ratio (the diameter-to-thickness ratio) of 80–240, which is an order of magnitude larger than those reported previously. For films with empirically optimized shapes, we find that it is possible to control the rotation speed in the range of 1–4 rotations per second while maintaining a positional stability of 12 ± 5 µm. The acoustic radiation force acting on the films is found to be a factor of 26–30 higher than that for same-volume water droplets. We propose use cases of the developed films for protein crystallography experiments and demonstrate data collections for large single crystal samples at room temperature.

The transient receptor potential vanilloid type 1 (TRPV1) is a multimodal receptor which responds to various stimuli, including capsaicin, protons, and heat. Recent advances in cryo-electron microscopy have revealed the structures of TRPV1. However, due to the large size of TRPV1 and its structural complexity, the detailed process of channel gating has not been well documented. In this study, we applied the diffracted X-ray tracking (DXT) technique to analyze the intracellular domain dynamics of the TRPV1 protein. DXT enables the capture of intramolecular motion through the analysis of trajectories of Laue spots generated from attached gold nanocrystals. Diffraction data were recorded at two different frame rates: 100 μs/frame and 12.5 ms/frame. The data from the 100 μs/frame recording were further divided into two groups based on the moving speed, using the lifetime filtering technique, and they were analyzed separately. Capsaicin increased the slope angle of the MSD curve of the C-terminus in 100 μs/frame recording, which accompanied a shifting of the rotational bias toward the counterclockwise direction, as viewed from the cytoplasmic side. This capsaicin-induced fluctuation was not observed in the 12.5 ms/frame recording, indicating that it is a high-frequency fluctuation. An intrinsiccounterclockwise twisting motion was observed in various speed components at the N-terminus, regardless of the capsaicin administration. Additionally, the competitive inhibitor AMG9810 induced a clockwise twisting motion, which is the opposite direction to capsaicin. These findings contribute to our understanding of the activation mechanisms of the TRPV1 channel.

IMPORTANCE:. Aggressive fluid resuscitation remains a cornerstone of the Surviving Sepsis Campaign (SSC) guidelines, but there is growing controversy regarding the recommended 30 mL/kg IV fluid dosage. It is contended that, in selected patients, this volume confers an increased risk of volume overload without either concomitant benefit or strong evidence in support of the recommended IV fluid dosage. OBJECTIVES:. Assessment of practice patterns and their impact on patient outcomes following the surviving sepsis guidelines for fluid resuscitation. DESIGN:. Large, multisite retrospective cohort study. SETTING AND PARTICIPANTS:. The retrospective study included all adult patients who presented to the emergency department at one of 19 different Mayo Clinic sites throughout the Midwest, Southeast, and Southwest from August 2018 to November 2020 with suspected sepsis. MAIN OUTCOMES AND MEASURES:. Eight-thousand four-hundred fourteen patients suspected to have sepsis were assessed regarding fluid resuscitation and outcomes among patients receiving 30 mL/kg IV fluid dosing compared with patients who did not. Patient demographics and clinical information were collected via electronic health records. Patients were divided into two cohorts: those who received 0–29.9 mL/kg of IV fluid and those who received 30.0+ mL/kg of IV fluid. Statistical analyses were performed to evaluate the impact of fluid dose on in-hospital death, 30-day mortality, ICU admission after diagnosis, dialysis initiation after diagnosis, ventilator use, vasopressor use, as well as ICU and hospital length of stay. RESULTS:. We observed lower in-hospital mortality and 30-day mortality risk in the 30+ mL/kg dosing group. Increased fluid dosage did, however, carry a much greater chance of ICU admission. Most patients (72% after propensity score weighting) in our population received less than 30 mL/kg fluid (based on ideal body weight). CONCLUSIONS AND RELEVANCE:. IV fluid dosing for sepsis resuscitation greater than 30 mL/kg was associated with decreased risk of in-hospital mortality, 30-day mortality, and reduced risk of requiring mechanical ventilation. Our data does ultimately seem to support the SSC recommendation.

Abstract The dynamic properties of crystalline materials are important for understanding their local environment or individual single-grain motions. A new time-resolved observation method is required for use in many fields of investigation. Here, we developed in situ diffracted X-ray blinking to monitor high-resolution diffraction patterns from single-crystal grains with a 50 ms time resolution. The diffraction spots of single grains of silver halides and silver moved in the θ and χ directions during the photolysis chemical reaction. The movements of the spots represent tilting and rotational motions. The time trajectory of the diffraction intensity reflecting those motions was analysed by using single-pixel autocorrelation function (sp-ACF). Single-pixel ACF analysis revealed significant differences in the distributions of the ACF decay constants between silver halides, suggesting that the motions of single grains are different between them. The rotational diffusion coefficients for silver halides were estimated to be accurate at the level of approximately 0.1 to 0.3 pm2/s. Furthermore, newly formed silver grains on silver halides correlated with their ACF decay constants. Our high-resolution atomic scale measurement—sp-ACF analysis of diffraction patterns of individual grains—is useful for evaluating physical properties that are broadly applicable in physics, chemistry, and materials science.

Abstract We investigate fluorescent defect centers in 4H silicon carbide p–n junction diodes fabricated via aluminum-ion implantation into an n-type bulk substrate without the use of an epitaxial growth process. At room temperature, electron-irradiated p–n junction diodes exhibit electroluminescence originating from silicon-vacancy defects. For a diode exposed to an electron dose of $$1 \times 10^{18}\,{{\mathrm{cm}}}^{-2}$$ 1 × 10 18 cm - 2 at $$800\,{{\mathrm{keV}}}$$ 800 keV , the electroluminescence intensity of these defects is most prominent within a wavelength range of 400– $$1100\,{{\mathrm{nm}}}$$ 1100 nm . The commonly observed $${{\mathrm{D}}}_1$$ D 1 emission was sufficiently suppressed in the electroluminescence spectra of all the fabricated diodes, while it was detected in the photoluminescence measurements. The photoluminescence spectra also displayed emission lines from silicon-vacancy defects.

The dynamic properties of protein molecules are involved in the relationship between their structure and function. Time-resolved X-ray observation enables capturing the structures of biomolecules with picometre-scale precision. However, this technique has yet to be implemented in living animals. Here, we examined diffracted X-ray blinking (DXB) and diffracted X-ray tracking (DXT) to observe the dynamics of a protein located on intestinal cells in adult Caenorhabditis elegans. This in vivo tissue-specific DXB was examined at temperatures from 20 °C to −10 °C for a recombinant ice-binding protein from Antarctomyces psychrotrophicus (AnpIBP) connected with the cells through a transmembrane CD4 protein equipped with a glycine-serine linker. AnpIBP inhibits ice growth at subzero temperatures by binding to ice crystals. We found that the rotational motion of AnpIBP decreases at −10 °C. In contrast, the motion of the AnpIBP mutant, which has a defective ice-binding ability, did not decrease at −10 °C. The twisting and tilting motional speeds of AnpIBPs measured above 5 °C by DXT were always higher than those of the defective AnpIBP mutant. These results suggest that wild-type AnpIBP is highly mobile in solution, and it is halted at subzero temperatures through ice binding. DXB and DXT allow for exploring protein behaviour in live animals with subnano resolution precision.

In recent years, real-time observations of molecules have been required to understand their behavior and function. To date, we have reported two different time-resolved observation methods: diffracted x-ray tracking and diffracted x-ray blinking (DXB). The former monitors the motion of diffracted spots derived from nanocrystals labeled onto target molecules, and the latter measures the fluctuation of the diffraction intensity that is highly correlated with the target molecular motion. However, these reports use a synchrotron x-ray source because of its high average flux, resulting in a high time resolution. Here, we used a laboratory x-ray source and DXB to measure the internal molecular dynamics of three different systems. The samples studied were bovine serum albumin (BSA) pinned onto a substrate, antifreeze protein (AFP) crystallized as a single crystal, and poly{2-(perfluorooctyl)ethyl acrylate} (PC8FA) polymer between polyimide sheets. It was found that not only BSA but also AFP and PC8FA molecules move in the systems. In addition, the molecular motion of AFP molecules was observed to increase with decreasing temperature. The rotational diffusion coefficients (DR) of BSA, AFP, and PC8FA were estimated to be 0.73 pm2/s, 0.65 pm2/s, and 3.29 pm2/s, respectively. Surprisingly, the DR of the PC8FA polymer was found to be the highest among the three samples. This is the first report that measures the molecular motion of a single protein crystal and polymer by using DXB with a laboratory x-ray source. This technique can be applied to any kind of crystal and crystalline polymer and provides atomic-order molecular information.

Background: Advanced Life Support (ALS) is regarded to be associated with improved survival in pre-hospital trauma care when compared to Basic Life Support (BLS) irrespective of lack of evidence. The aim of this study is to ascertain ALS improves survival for trauma in prehospital settings when compared to BLS.Methods: We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials for published controlled trials (CTs), and observational studies that were published until Aug 2017. The population of interest were adults (>18 years old) trauma patients who were transported by ground transportation and required resuscitation in prehospital settings. We compared outcomes between the ALS and BLS groups. The primary outcome was in-hospital mortality and secondary outcomes were neurological outcome and time spent on scene.Results: We identified 2,502 studies from various databases and 10 studies were included in the analysis (two CTs, and eight observational studies). The outcomes were not statistically significant between the ALS and BLS groups (pooled OR 1.14; 95% CI 0.95 to 1.36 for mortality, pooled OR 1.12; 95% CI 0.88 to 1.42 for good neurological outcomes, pooled mean difference −0.96; 95% CI−6.64 to 4.72 for on-scene time) in CTs. In observational studies, ALS prolonged on-scene time and increased mortality (pooled OR 1.56; 95% CI: 1.31 to 1.86 for mortality, and pooled mean difference, 1.26; 95% CI: 0.07 to 2.45 for on-scene time).Conclusions: In prehospital settings, the present study showed no advantages of ALS on the outcomes in patients with trauma compared to BLS.

Abstract Background The purpose of this study was to determine the ideal timing for providers to perform point-of-care ultrasound (POCUS) with the least increase in workload. Methods We conducted a pilot crossover study to compare 2 POCUS-assisted evaluation protocols for acutely ill patients: sequential (physical examination followed by POCUS) vs parallel (POCUS at the time of physical examination). Participants were randomly assigned to 2 groups according to which POCUS-assisted protocol (sequential vs parallel) was used during simulated scenarios. Subsequently, the groups were crossed over to complete assessment by using the other POCUS-assisted protocol in the same patient scenarios. Providers’ workloads, measured with the National Aeronautics and Space Administration Task Load Index (NASA-TLX) and time to complete patient evaluation, were compared between the 2 protocols. Results Seven providers completed 14 assessments (7 sequential and 7 parallel). The median (IQR) total NASA-TLX score was 30 (30–50) in the sequential and 55 (50–65) in the parallel protocol (P = .03), which suggests a significantly lower workload in the sequential protocol. When individual components of the NASA-TLX score were evaluated, mental demand and frustration level were significantly lower in the sequential than in the parallel protocol (40 [IQR, 30–60] vs 50 [IQR, 40–70]; P = .03 and 25 [IQR, 20–35] vs 60 [IQR, 45–85]; P = .02, respectively). The time needed to complete the assessment was similar between the sequential and parallel protocols (8.7 [IQR, 6–9] minutes vs 10.1 [IQR, 7–11] minutes, respectively; P = .30). Conclusions A sequential POCUS-assisted protocol posed less workload to POCUS operators than the parallel protocol.

Rib fracture is a common injury resulting from blunt thoracic trauma. Although hemothorax and pneumothorax are known delayed complications of rib fracture, delayed chest wall hematoma has rarely been reported. We discuss the case of an 81-year-old woman who was not undergoing antiplatelet or anticoagulant therapy who presented to our emergency department after a traffic injury. This patient had a nondisplaced rib fracture that went undetected on the initial computed tomography scan; the development of progressive displacement led to hemorrhagic shock due to delayed chest wall hematoma. The chest wall hematoma was effectively diagnosed and treated via contrast-enhanced computed tomography and angiographic embolization. This case highlights the possibility of this potential delayed complication from a common injury such as a rib fracture. Keywords: Angiography, Chest wall, Delayed complication, Rib fracture, Thoracic injury

The eukaryotic group II chaperonin, the chaperonin-containing t-complex polypeptide 1 (CCT), plays an important role in cytosolic proteostasis. It has been estimated that as much as 10% of cytosolic proteins interact with CCT during their folding process. CCT is composed of 8 different paralogous subunits. Due to its complicated structure, molecular and biochemical investigations of CCT have been difficult. In this study, we constructed an expression system for CCT from a thermophilic fungus, Chaetomium thermophilum (CtCCT), by using E. coli as a host. As expected, we obtained recombinant CtCCT with a relatively high yield, and it exhibited fairly high thermal stability. We showed the advantages of the overproduction system by characterizing CtCCT variants containing ATPase-deficient subunits. For diffracted X-ray tracking experiment, we removed all surface exposed cysteine residues, and added cysteine residues at the tip of helical protrusions of selected two subunits. Gold nanocrystals were attached onto CtCCTs via gold-thiol bonds and applied for the analysis by diffracted X-ray tracking. Irrespective of the locations of cysteines, it was shown that ATP binding induces tilting motion followed by rotational motion in the CtCCT molecule, like the archaeal group II chaperonins. When gold nanocrystals were attached onto two subunits in the high ATPase activity hemisphere, the CtCCT complex exhibited a fairly rapid response to the motion. In contrast, the response of CtCCT, which had gold nanocrystals attached to the low-activity hemisphere, was slow. These results clearly support the possibility that ATP-dependent conformational change starts with the high-affinity hemisphere and progresses to the low-affinity hemisphere.

Immunoglobulin (Ig) G4-related disease (also known as ‘IgG4-related sclerosing disease’, ‘IgG4-related systemic disease’ or ‘hyper-IgG4-disease’) is a recently recognized systemic fibroinflammatory disease associated with IgG4-positive plasma cells in tissue lesions. IgG4-related disease was initially described as autoimmune pancreatitis, but it is now known to affect virtually any organ. The authors describe a patient presenting with multi-organ manifestations, including airway inflammation mimicking asthma, pulmonary parenchymal infiltrates, intrathoracic lymphadenopathy, submandibular gland swelling and a kidney mass.