Beyond Local Structures in Critical Supercooled Water through Unsupervised Learning

The presence of a second critical point in water has been a topic of intense investigation for the last few decades. The molecular origins underlying this phenomenon are typically rationalized in terms of the competition between local high-density (HD) and low-density (LD) structures. Their identification often requires designing parameters that are subject to human intervention. Herein, we use unsupervised learning to discover structures in atomistic simulations of water close to the liquid-liquid critical point (LLCP). Encoding the information on the environment using local descriptors, we do not find evidence for two distinct thermodynamic structures. In contrast, when we deploy nonlocal descriptors that probe instead heterogeneities on the nanometer length scale, this leads to the emergence of LD and HD domains rationalizing the microscopic origins of the density fluctuations close to criticality.

Herbivore effects increase with latitude across the extent of a foundational seagrass

Climate change is altering the functioning of foundational ecosystems. While the direct effects of warming are expected to influence individual species, the indirect effects of warming on species interactions remain poorly understood. In marine systems, as tropical herbivores undergo poleward range expansion, they may change food web structure and alter the functioning of key habitats. While this process ('tropicalization') has been documented within declining kelp forests, we have a limited understanding of how this process might unfold across other systems. Here we use a network of sites spanning 23° of latitude to explore the effects of increased herbivory (simulated via leaf clipping) on the structure of a foundational marine plant (turtlegrass). By working across its geographic range, we also show how gradients in light, temperature and nutrients modified plant responses. We found that turtlegrass near its northern boundary was increasingly affected (reduced productivity) by herbivory and that this response was driven by latitudinal gradients in light (low insolation at high latitudes). By contrast, low-latitude meadows tolerated herbivory due to high insolation which enhanced plant carbohydrates. We show that as herbivores undergo range expansion, turtlegrass meadows at their northern limit display reduced resilience and may be under threat of ecological collapse.

Topological Kolmogorov complexity and the Berezinskii-Kosterlitz-Thouless mechanism

Topology plays a fundamental role in our understanding of many-body physics, from vortices and solitons in classical field theory to phases and excitations in quantum matter. Topological phenomena are intimately connected to the distribution of information content that, differently from ordinary matter, is now governed by nonlocal degrees of freedom. However, a precise characterization of how topological effects govern the complexity of a many-body state, i.e., its partition function, is presently unclear. In this paper, we show how topology and complexity are directly intertwined concepts in the context of classical statistical mechanics. We concretely present a theory that shows how the Kolmogorov complexity of a classical partition function sampling carries unique, distinctive features depending on the presence of topological excitations in the system. We confront two-dimensional Ising, Heisenberg, and XY models on several topologies and study the corresponding samplings as high-dimensional manifolds in configuration space, quantifying their complexity via the intrinsic dimension. While for the Ising and Heisenberg models the intrinsic dimension is independent of the real-space topology, for the XY model it depends crucially on temperature: across the Berezkinskii-Kosterlitz-Thouless (BKT) transition, complexity becomes topology dependent. In the BKT phase, it displays a characteristic dependence on the homology of the real-space manifold, and, for g-torii, it follows a scaling that is solely genus dependent. We argue that this behavior is intimately connected to the emergence of an order parameter in data space, the conditional connectivity, which displays scaling behavior. Our approach paves the way for an understanding of topological phenomena emergent from many-body interactions from the perspective of Kolmogorov complexity.

Microbiomes of Thalassia testudinum throughout the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico are influenced by site and region while maintaining a core microbiome

Plant microbiomes are known to serve several important functions for their host, and it is therefore important to understand their composition as well as the factors that may influence these microbial communities. The microbiome of Thalassia testudinum has only recently been explored, and studies to-date have primarily focused on characterizing the microbiome of plants in a single region. Here, we present the first characterization of the composition of the microbial communities of T. testudinum across a wide geographical range spanning three distinct regions with varying physicochemical conditions. We collected samples of leaves, roots, sediment, and water from six sites throughout the Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. We then analyzed these samples using 16S rRNA amplicon sequencing. We found that site and region can influence the microbial communities of T. testudinum, while maintaining a plant-associated core microbiome. A comprehensive comparison of available microbial community data from T. testudinum studies determined a core microbiome composed of 14 ASVs that consisted mostly of the family Rhodobacteraceae. The most abundant genera in the microbial communities included organisms with possible plant-beneficial functions, like plant-growth promoting taxa, disease suppressing taxa, and nitrogen fixers.

Improving acute stroke assessment in non-enhanced computed tomography: automated tool for early ischemic lesion volume detection

BACKGROUND AND OBJECTIVES

ASPECTs is a widely used marker to identify early stroke signs on non-enhanced computed tomography (NECT), yet it presents interindividual variability and it may be hard to use for non-experts. We introduce an algorithm capable of automatically estimating the NECT volumetric extension of early acute ischemic changes in the 3D space. We compared the power of this marker with ASPECTs evaluated by experienced practitioner in predicting the clinical outcome.

METHODS

We analyzed and processed neuroimaging data of 153 patients admitted with acute ischemic stroke. All patients underwent a NECT at admission and on follow-up. The developed algorithm identifies the early ischemic hypodense region based on an automatic comparison of the gray level in the images of the two hemispheres, assumed to be an approximate mirror image of each other in healthy patients.

RESULTS

In the two standard axial slices used to estimate the ASPECTs, the regions identified by the algorithm overlap significantly with those identified by experienced practitioners. However, in many patients, the regions identified automatically extend significantly to other slices. In these cases, the volume marker provides supplementary and independent information. Indeed, the clinical outcome of patients with volume marker = 0 can be distinguished with higher statistical confidence than the outcome of patients with ASPECTs = 10.

CONCLUSION

The volumetric extension and the location of acute ischemic region in the 3D-space, automatically identified by our algorithm, provide data that are mostly in agreement with the ASPECTs value estimated by expert practitioners, and in some cases complementary and independent.

Clinical Comparison of Three Indirect Pulp Capping Restorative Protocols: A Randomized Controlled Prospective Study

OBJECTIVES

The objective of this prospective double-blind clinical trial was to compare clinical outcomes of indirect pulp capping restorative protocols on permanent teeth over a 12-month period.

METHODS AND MATERIALS

Deep carious lesions in permanent teeth (90) were randomly assigned to three indirect pulp capping protocols (n=30: TheraCal LC, Dycal, and no liner). All teeth were restored with resin composite. The outcome measures were pain (VAS scale) and success rate (pulp vitality based on percussion, palpation, cold test, and radiographic findings), collected at screening, intervention, and 24-hour, 7-day, 3-month, 6-month, and 12-month follow-up visits.

RESULTS

There was no statistically significant difference in tooth sensitivity among the three indirect pulp capping protocols nor in success rates among the restorative protocols after 1 year of follow-up (p>0.1).The respective success rates, as defined by the tooth remaining vital, after 1 year were: 96.2% for TheraCal LC, 100% for Dycal, and 100% for no liner.

CONCLUSIONS

After 12-month evaluation, the success rate of indirect pulp capping therapy on permanent teeth was not affected by the pulp capping restorative protocol.

A Preliminary Controlled Trial of Endoscopic Ultrasound-guided Fiducial Markers to Guide Pancreas Surgery

OBJECTIVE

Endoscopic ultrasound (EUS) is routinely used for fiducial marker placement (FMP) to guide stereotactic radiation of pancreatic tumors, but EUS-FMP explicitly to guide surgery has not been studied in a prospective, controlled manner. Multipurpose EUS systems have been developed that facilitate simultaneous EUS-FMP at the time of biopsy. We aimed to evaluate the feasibility of EUS-FMP to guide pancreatic resection.

METHODS

In this prospective trial, we enrolled patients with resectable pancreas masses undergoing tissue sampling and placed preloaded fiducials immediately after biopsy. Intraprocedure confirmation of carcinoma, neuroendocrine, and nonlymphomatous neoplasia by rapid on-site evaluation and lesion size <4 cm was required. The main outcomes were the feasibility and ease of preoperative placement and intraoperative detection of the markers using predefined Likert scales.

RESULTS

In 20 patients, EUS-FMP was successful before planned surgery and placement was technically straightforward (Likert Scale: 9.1 ± 1.3; range: 1, most challenging to 10, most facile). Intraoperative detection was feasible and improved when compared with a pre-established comparator of 5 representing an equivalent lesion without a marker (Likert Scale: 7.8 ± 2.2; range: 1, most difficult to 10, most facile; P = 0.011). The mean tumor size on EUS was 1.7 ± 0.9 (range: 0.5 to 3.6) cm.

CONCLUSION

EUS-FMP is feasible and safe for resectable pancreatic tumors before surgery and may assist in perioperative detection. Preloaded fiducials may be considered for placement at the time of initial referral for EUS-fine needle biopsy.

Classroom aerosol dispersion modeling: experimental assessment of a low-cost flow simulation tool

The purpose of this study was to assess the utility of a low-cost flow simulation tool for an indoor air modeling application by comparing its outputs with the results of a physical experiment, as well as those from a more advanced computational fluid dynamics (CFD) software package. Five aerosol dispersion tests were performed in two different classrooms by releasing a CO2 tracer gas from six student locations. Resultant steady-state concentrations were monitored at 13 locations around the periphery of the room. Subsequently, the experiments were modeled using both a low-cost tool (SolidWorks Flow Simulation) and a more sophisticated tool (STAR-CCM+). Models were evaluated based on their ability to predict the experimentally measured concentrations at the 13 monitoring locations by calculating four performance parameters commonly used in the evaluation of dispersion models: fractional mean bias (FB), normalized mean-square error (NMSE), fraction of predicted value within a factor of two (FAC2), and normalized absolute difference (NAD). The more sophisticated model performed better in 15 of the 20 possible cases (five tests at four parameters each), with parameters meeting acceptance criteria in 19 of 20 cases. However, the lower-cost tool was only slightly worse, with parameters meeting acceptance criteria in 18 of 20 cases, and it performed better than the other tool in 3 of 20 cases. Because it provides useful results at a fraction of the monetary and training cost and is already widely accessible to many institutions, such a tool may be worthwhile for many indoor aerosol dispersion applications, especially for students or researchers just beginning CFD modeling.

ZundEig: The Structure of the Proton in Liquid Water from Unsupervised Learning

The structure of the excess proton in liquid water has been the subject of lively debate on both experimental and theoretical fronts for the last century. Fluctuations of the proton are typically interpreted in terms of limiting states referred to as the Eigen and Zundel species. Here, we put these ideas under the microscope, taking advantage of recent advances in unsupervised learning that use local atomic descriptors to characterize environments of acidic water combined with advanced clustering techniques. Our agnostic approach leads to the observation of only one charged cluster and two neutral ones. We demonstrate that the charged cluster involving the excess proton is best seen as an ionic topological defect in water's hydrogen bond network, forming a single local minimum on the global free-energy landscape. This charged defect is a highly fluxional moiety, where the idealized Eigen and Zundel species are neither limiting configurations nor distinct thermodynamic states. Instead, the ionic defect enhances the presence of neutral water defects through strong interactions with the network. We dub the combination of the charged and neutral defect clusters as ZundEig, demonstrating that the fluctuations between these local environments provide a general framework for rationalizing more descriptive notions of the proton in the existing literature.

Targeted temperature management and PbtO2 in traumatic brain injury

Introduction

Targeted Temperature Management (TTM) to normothermia is widely used in traumatic brain injury (TBI). We investigated the effects to of TTM to normothermia patients with TBI (GCS≤12) monitored with multimodality monitoring, to better understand the physiological consequences of this intervention.

Research question

In TBI patients cooled to normothermia and in which brain oxygenation deteriorates, are there changes in physiological parameters which are pertinent to brain oxygenation?

Material and method

102 TBI patients with continuous recordings of intracranial pressure (ICP) and brain oxygen tension (PbtO2) were studied retrospectively. Non-continuous arterial carbon dioxide (PaCO2) and oxygen (PaO2) tensions, and core body temperature (Tc) were added. PaO2 and PaCO2 were also corrected for Tc. Transitions from elevated Tc to normothermia were identified in 39 patients. The 8 h pre and post the transition to normothermia were compared. Data is given as median [IQR] or mean (SD).

Results

Overall, normothermia reduced ICP (12 [9-18] -11 [8-17] mmHg, p < 0.009) and Tcore (38.3 [0.3]-36.9 [0.4] oC, p < 0.001), but not PbtO2 (23.3 [16.6]-24.4 [17.2-28.7] mmHg, NS). Normothermia was associated with a fall in PbtO2 in 18 patients (24.5 [9.3] -20.8 [7.6] mmHg). Only in those with a fall in PbtO2 with cooling did ICP (15 [10.8-18.5] -12 [7.8-17.3] mmHg, p = 0.002), and temperature corrected PaCO2 (5.3 [0.5]- 4.9 [0.8] kPa, p = 0.001) decrease.

Discussion and conclusion

A reduction in PbtO2 was only present in the subgroup of patients with a fall in temperature corrected PaCO2 with cooling. This suggests that even modest temperature changes could result in occult hyperventilation in some patients. pH stat correction of ventilation may be an important factor to consider in future TTM protocols.

The carbonyl-lock mechanism underlying non-aromatic fluorescence in biological matter

Challenging the basis of our chemical intuition, recent experimental evidence reveals the presence of a new type of intrinsic fluorescence in biomolecules that exists even in the absence of aromatic or electronically conjugated chemical compounds. The origin of this phenomenon has remained elusive so far. In the present study, we identify a mechanism underlying this new type of fluorescence in different biological aggregates. By employing non-adiabatic ab initio molecular dynamics simulations combined with a data-driven approach, we characterize the typical ultrafast non-radiative relaxation pathways active in non-fluorescent peptides. We show that the key vibrational mode for the non-radiative decay towards the ground state is the carbonyl elongation. Non-aromatic fluorescence appears to emerge from blocking this mode with strong local interactions such as hydrogen bonds. While we cannot rule out the existence of alternative non-aromatic fluorescence mechanisms in other systems, we demonstrate that this carbonyl-lock mechanism for trapping the excited state leads to the fluorescence yield increase observed experimentally, and set the stage for design principles to realize novel non-invasive biocompatible probes with applications in bioimaging, sensing, and biophotonics.

Zirconium Coordination Chemistry and Its Role in Optimizing Hydroxymate Chelation: Insights from Molecular Dynamics

In the past decade, there has been a growth in using Zirconium-89 (89Zr) as a radionuclide in nuclear medicine for cancer diagnostic imaging and drug discovery processes. Although one of the most popular chelators for 89Zr, desferrioxamine (DFO) is typically presented as a hexadentate ligand, our work suggests a different scenario. The coordination structure of the Zr4+-DFO complex has primarily been informed by DFT-based calculations, which typically ignore temperature and therefore entropic and dynamic solvent effects. In this work, free energy calculations using molecular dynamics simulations, where the conformational fluctuations of both the ligand and the solvent are explicitly included, are used to compare the binding of Zr4+ cations with two different chelators, DFO and 4HMS, the latter of which is an octadentate ligand that has been recently proposed as a better chelator due to the presence of four hydroxymate groups. We find that thermally induced disorder leads to an open hexadentate chelate structure of the Zr4+-DFO complex, leaving the Zr4+ metal exposed to the solvent. A stable coordination of Zr4+ with 4HMS, however, is formed by involving both hydroxamate groups and water molecules in a more closely packed structure.

Surgically Targeted Radiation Therapy (STaRT) for Brain Metastases: Initial Experience from a Prospective Multi-Institutional Registry

PURPOSE/OBJECTIVE(S)

Resection and intraoperative brachytherapy for patients with large, operable brain metastasis allows for both relief of mass effect and the delivery of radiotherapy (RT) to the resection cavity with a favorable dosimetric profile. The objective of this study was to analyze early patterns-of-care and treatment-related toxicity outcomes for brain metastasis patients treated with surgically targeted radiation therapy (STaRT) using a novel brachytherapy carrier.

MATERIALS/METHODS

Patients with brain metastasis, de novo and recurrent disease, who enrolled onto a prospective multi-institutional observational study (NCT04427384) were the subject of this analysis. Patients underwent resection and immediate implantation of bioresorbable, conformable, 20 mm x 20 mm x 4 mm collagen tile brachytherapy device(s) containing four uniform-intensity Cesium-131 sources. Toxicities were categorized using the CTCAE v5.0 adverse event (AE) criteria.

RESULTS

From 10/2020 to 01/2023, 13 participating sites enrolled and treated 48 patients with 51 metastases (13 with de novo and 35 patients with recurrent brain metastases), and 3 patients had 2 lesions implanted at the same procedure. Median age was 61 years (range: 28-80), 52% were female, and the most common primary types were lung (56%) and breast (13%). The median maximum pre-operative dimension was 3.4 cm (range: 1.7-5.7) and median pre-operative tumor volume 13.7cm3 (range: 1.7-132). 64% had received prior RT with a median time from last RT to STaRT of 14.6 months range: 3.5-57.3). Median KPS at screening was 80 (range: 50-100), and remained stable at post op visit (80, range: 50-100), and at 3-months following treatment (80, range 50-100), respectively (p>0.05). The median time for implantation was 3 minutes (range: 0.4-30). At a median follow-up of 4 months (range: <1-18), no patient experienced a radiation-attributed AE, and only 1 attributable Gr >3 AE was noted (Gr 5 intracerebral hemorrhage deemed probably related to surgery and unrelated to the implanted device).

CONCLUSION

Early results from this prospective multi-center trial demonstrate the feasibility and safety of STaRT. The lack of radiation-related AE, even with short follow-up, is intriguing given the relatively large lesion size and proportion of patients treated for recurrent, previously irradiated disease. Additional follow-up will provide data on tumor control outcomes and radiation necrosis rates using this novel technique.

Implementing Standardized Patient Education in Radiation Oncology

PURPOSE/OBJECTIVE(S)

Patient education empowers patients, improving their health status during and after cancer treatment (Howell et al., 2017). We hypothesize that standardizing healthcare provider delivery of educational materials (HPE) using an electronic medical record (EMR) will increase delivery to patients (pts).

MATERIALS/METHODS

During the study period (9/2020 - 11/2022) 13,650 pts in a multi-centered single health system (HS) received HPE and were analyzed in a retrospective convenience sample frame. There were 16,769 education touchpoints from Radiation Oncology departments (RO) and 8,269 from Medical Oncology (MO) departments. Provision of HPE was standardized in RO during this era. Relationship of ethnicity, age, and sex/gender to receipt of HPE at single vs multiple time points across the HS was examined using association analysis.

RESULTS

Within the combined sample taken from RO and MO departments in the HS the mean pt age was 64y (7 - >90); 71% of pts identified as white, 95.7% non-Hispanic, and 55% female. Across ethnicity, age, and sex/gender, increased HPE was provided in RO vs MO departments (p < 0.001). Distribution of HPE in RO was equal between male and female pts (73%), while distribution to female pts was higher than male in MO. (60% vs 57%, p < 0.001). Receipt of HPE at more than one time point was increased in RO across cancer types (Table 1). In RO, 73% of patients received education at more than one time point, compared to 58.7% in other departments (p < 0.001). Receipt of HPE at more than one time point was increased in RO for patients identifying as American Indian or Alaska Native (84% vs 0, p = 0.001, n = 28), Asian (73.4% vs 56%, p < 0.001, n = 824), and Black (75% vs 60%, p < 0.001, n = 4005). HPE was received at more than one time point in RO in 75.7% of patients age 7-39, 76.4% 40-64, 71.2% 65-79, and 67.6% in those 80 and above, compared to 62.0%, 63.2%, 56.3%, and 49.2%, respectively in MO departments (p = <0.01).

CONCLUSION

Standardization of HPE within RO increased delivery to patients across gender, race/ethnicity, age, and cancer diagnosis, particularly regarding number of educational touchpoints for patients in underserved populations based on race and age. Our results suggest that widespread standardization of HPE is likely to improve distribution of education to all patient groups and should be systematically supported.

Complexity of spin configuration dynamics due to unitary evolution and periodic projective measurements

We study the Hamiltonian dynamics of a many-body quantum system subjected to periodic projective measurements, which leads to probabilistic cellular automata dynamics. Given a sequence of measured values, we characterize their dynamics by performing a principal component analysis (PCA). The number of principal components required for an almost complete description of the system, which is a measure of complexity we refer to as PCA complexity, is studied as a function of the Hamiltonian parameters and measurement intervals. We consider different Hamiltonians that describe interacting, noninteracting, integrable, and nonintegrable systems, including random local Hamiltonians and translational invariant random local Hamiltonians. In all these scenarios, we find that the PCA complexity grows rapidly in time before approaching a plateau. The dynamics of the PCA complexity can vary quantitatively and qualitatively as a function of the Hamiltonian parameters and measurement protocol. Importantly, the dynamics of PCA complexity present behavior that is considerably less sensitive to the specific system parameters for models which lack simple local dynamics, as is often the case in nonintegrable models. In particular, we point out a figure of merit that considers the local dynamics and the measurement direction to predict the sensitivity of the PCA complexity dynamics to the system parameters.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

High-Throughput Screening of Promising Redox-Active Molecules with MolGAT

Redox flow batteries (RFBs) have emerged as a promising option for large-scale energy storage, owing to their high energy density, low cost, and environmental benefits. However, the identification of organic compounds with high redox activity, aqueous solubility, stability, and fast redox kinetics is a crucial and challenging step in developing an RFB technology. Density functional theory-based computational materials prediction and screening is a time-consuming and computationally expensive technique, yet it has a high success rate. To speed up the discovery of new materials with desired properties, machine-learning-based models can be trained on large data sets. Graph neural networks (GNNs) are particularly well-suited for non-Euclidean data and can model complex relationships, making them ideal for accelerating the discovery of novel materials. In this study, a GNN-based model called MolGAT was developed to predict the redox potential of organic molecules using molecular structures, atomic properties, and bond attributes. The model was trained on a data set of over 15,000 compounds with redox potentials ranging from -4.11 to 2.56. MolGAT outperformed other GNN variants, such as the Graph Attention Network, Graph Convolution Network, and AttentiveFP models. The trained model was used to screen a vast chemical data set comprising 581,014 molecules, namely OMDB, QM9, ZINC, CHEMBL, and DELANEY, and identified 23,467 potential redox-active compounds for use in redox flow batteries. Of those, 20,716 molecules were identified as potential catholytes with predicted redox potentials up to 2.87 V, while 2,751 molecules were deemed potential anolytes with predicted redox potentials as low as -2.88 V. This work demonstrates the capabilities of graph neural networks in condensed matter physics and materials science to screen promising redox-active species for further electronic structure calculations and experimental testing.

Diversity and Scale: Genetic Architecture of 2,068 Traits in the VA Million Veteran Program

Genome-wide association studies (GWAS) have underrepresented individuals from non-European populations, impeding progress in characterizing the genetic architecture and consequences of health and disease traits. To address this, we present a population-stratified phenome-wide GWAS followed by a multi-population meta-analysis for 2,068 traits derived from electronic health records of 635,969 participants in the Million Veteran Program (MVP), a longitudinal cohort study of diverse U.S. Veterans genetically similar to the respective African (121,177), Admixed American (59,048), East Asian (6,702), and European (449,042) superpopulations defined by the 1000 Genomes Project. We identified 38,270 independent variants associating with one or more traits at experiment-wide P < 4.6 × 10 - 11 significance; fine-mapping 6,318 signals identified from 613 traits to single-variant resolution. Among these, a third (2,069) of the associations were found only among participants genetically similar to non-European reference populations, demonstrating the importance of expanding diversity in genetic studies. Our work provides a comprehensive atlas of phenome-wide genetic associations for future studies dissecting the architecture of complex traits in diverse populations.

Usability, accuracy, and cost-effectiveness of a medical software for early pregnancies: a retrospective study

STUDY QUESTION

Can early pregnancies be accurately and cost-effectively diagnosed and managed using a new medical computerized tool?

SUMMARY ANSWER

Compared to the standard clinical approach, retrospective implementation of the new medical software in a gynaecological emergency unit was correlated with more accurate diagnosis and more cost-effective management.

WHAT IS KNOWN ALREADY

Early pregnancy complications are responsible for a large percentage of consultations, mostly in emergency units, with guidelines becoming complex and poorly known/misunderstood by practitioners.

STUDY DESIGN, SIZE, DURATION

A total of 780 gynaecological emergency consultations (446 patients), recorded between November 2018 and June 2019 in a tertiary university hospital, were retrospectively encoded in a new medical computerized tool. The inclusion criteria were a positive hCG test result, ultrasonographical visualization of gestational sac, and/or embryo corresponding to a gestational age of 14 weeks or less. Diagnosis and management suggested by the new computerized tool are named eDiagnoses, while those provided by a gynaecologist member of the emergency department staff are called medDiagnoses.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Usability was the primary endpoint, with accuracy and cost reduction, respectively, as secondary and tertiary endpoints. Identical eDiagnoses/medDiagnoses were considered as accurate. During follow-up visits, if the updated eDiagnoses and medDiagnoses became both identical to a previously discrepant eDiagnosis or medDiagnosis, this previous eDiagnosis or medDiagnosis was also considered as correct. Four double-blinded experts reviewed persistent discrepancies, determining the accurate diagnoses. eDiagnoses/medDiagnoses accuracies were compared using McNemar's Chi square test, sensitivity, specificity, and predictive values.

MAIN RESULTS AND THE ROLE OF CHANCE

Only 1 (0.1%) from 780 registered medical records lacked data for full encoding. Out of the 779 remaining consultations, 675 eDiagnoses were identical to the medDiagnoses (86.6%) and 104 were discrepant (13.4%). From these 104, 60 reached an agreement during follow-up consultations, with 59 medDiagnoses ultimately changing into the initial eDiagnoses (98%) and only one discrepant eDiagnosis turning later into the initial medDiagnosis (2%). Finally, 24 remained discrepant at all subsequent checks and 20 were not re-evaluated. Out of these 44, the majority of experts agreed on 38 eDiagnoses (86%) and 5 medDiagnoses (11%, including four twin pregnancies whose twinness was the only discrepancy). No majority was reached for one discrepant eDiagnosis/medDiagnosis (2%). In total, the accuracy of eDiagnoses was 99.1% (675 + 59 + 38 = 772 eDiagnoses out of 779), versus 87.4% (675 + 1 + 5 = 681) for medDiagnoses (P < 0.0001). Calculating all basic costs of extra consultations, extra-medications, extra-surgeries, and extra-hospitalizations induced by incorrect medDiagnoses versus eDiagnoses, the new medical computerized tool would have saved 3623.75 Euros per month. Retrospectively, the medical computerized tool was usable in almost all the recorded cases (99.9%), globally more accurate (99.1% versus 87.4%), and for all diagnoses except twinning reports, and it was more cost-effective than the standard clinical approach.

LIMITATIONS, REASONS FOR CAUTION

The retrospective study design is a limitation. Some observed improvements with the medical software could derive from the encoding by a rested and/or more experienced physician who had a better ultrasound interpretation. This software cannot replace clinical and ultrasonographical skills but may improve the compliance to published guidelines.

WIDER IMPLICATIONS OF THE FINDINGS

This medical computerized tool is improving. A new version considers diagnosis and management of multiple pregnancies with their specificities (potentially multiple locations, chorioamnionicity). Prospective evaluations will be required. Further developmental steps are planned, including software incorporation into ultrasound devices and integration of previously published predictive/prognostic factors (e.g. serum progesterone, corpus luteum scoring).

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was obtained for this study. F.B. and D.G. created the new medical software.

TRIAL REGISTRATION NUMBER

NCT03993015.

Eukaryotic-like gephyrin and cognate membrane receptor coordinate corynebacterial cell division and polar elongation

The order Corynebacteriales includes major industrial and pathogenic actinobacteria such as Corynebacterium glutamicum or Mycobacterium tuberculosis . Their elaborate multi-layered cell wall, composed primarily of the mycolyl-arabinogalactan-peptidoglycan complex, and their polar growth mode impose a stringent coordination between the septal divisome, organized around the tubulin-like protein FtsZ, and the polar elongasome, assembled around the tropomyosin-like protein Wag31. Here, we report the identification of two new divisome members, a gephyrin-like repurposed molybdotransferase (GLP) and its membrane receptor (GLPR). We show that the interplay between the GLPR/GLP module, FtsZ and Wag31 is crucial for orchestrating cell cycle progression. Our results provide a detailed molecular understanding of the crosstalk between two essential machineries, the divisome and elongasome, and reveal that Corynebacteriales have evolved a protein scaffold to control cell division and morphogenesis similar to the gephyrin/GlyR system that in higher eukaryotes mediates synaptic signaling through network organization of membrane receptors and the microtubule cytoskeleton.

Identification of Novel, Replicable Genetic Risk Loci for Suicidal Thoughts and Behaviors Among US Military Veterans

Importance

Suicide is a leading cause of death; however, the molecular genetic basis of suicidal thoughts and behaviors (SITB) remains unknown.

Objective

To identify novel, replicable genomic risk loci for SITB.

Design, Setting, and Participants

This genome-wide association study included 633 778 US military veterans with and without SITB, as identified through electronic health records. GWAS was performed separately by ancestry, controlling for sex, age, and genetic substructure. Cross-ancestry risk loci were identified through meta-analysis. Study enrollment began in 2011 and is ongoing. Data were analyzed from November 2021 to August 2022.

Main Outcome and Measures

SITB.

Results

A total of 633 778 US military veterans were included in the analysis (57 152 [9%] female; 121 118 [19.1%] African ancestry, 8285 [1.3%] Asian ancestry, 452 767 [71.4%] European ancestry, and 51 608 [8.1%] Hispanic ancestry), including 121 211 individuals with SITB (19.1%). Meta-analysis identified more than 200 GWS (P < 5 × 10-8) cross-ancestry risk single-nucleotide variants for SITB concentrated in 7 regions on chromosomes 2, 6, 9, 11, 14, 16, and 18. Top single-nucleotide variants were largely intronic in nature; 5 were independently replicated in ISGC, including rs6557168 in ESR1, rs12808482 in DRD2, rs77641763 in EXD3, rs10671545 in DCC, and rs36006172 in TRAF3. Associations for FBXL19 and AC018880.2 were not replicated. Gene-based analyses implicated 24 additional GWS cross-ancestry risk genes, including FURIN, TSNARE1, and the NCAM1-TTC12-ANKK1-DRD2 gene cluster. Cross-ancestry enrichment analyses revealed significant enrichment for expression in brain and pituitary tissue, synapse and ubiquitination processes, amphetamine addiction, parathyroid hormone synthesis, axon guidance, and dopaminergic pathways. Seven other unique European ancestry-specific GWS loci were identified, 2 of which (POM121L2 and METTL15/LINC02758) were replicated. Two additional GWS ancestry-specific loci were identified within the African ancestry (PET112/GATB) and Hispanic ancestry (intergenic locus on chromosome 4) subsets, both of which were replicated. No GWS loci were identified within the Asian ancestry subset; however, significant enrichment was observed for axon guidance, cyclic adenosine monophosphate signaling, focal adhesion, glutamatergic synapse, and oxytocin signaling pathways across all ancestries. Within the European ancestry subset, genetic correlations (r > 0.75) were observed between the SITB phenotype and a suicide attempt-only phenotype, depression, and posttraumatic stress disorder. Additionally, polygenic risk score analyses revealed that the Million Veteran Program polygenic risk score had nominally significant main effects in 2 independent samples of veterans of European and African ancestry.

Conclusions and Relevance

The findings of this analysis may advance understanding of the molecular genetic basis of SITB and provide evidence for ESR1, DRD2, TRAF3, and DCC as cross-ancestry candidate risk genes. More work is needed to replicate these findings and to determine if and how these genes might impact clinical care.

Attitudes of Newly Hired Medicine Faculty Regarding Mentorship and Developmental Networks

Prior research shows that most Schools of Medicine faculty consider mentorship the most crucial factor in faculty development and retention. Many faculty are establishing developmental networks in lieu of hierarchical dyadic mentoring relationships. Clinicians are less likely than other newly hired faculty groups to seek mentorship despite having assigned mentors. The study's purpose was to determine the attitudes of newly hired faculty at the University of New Mexico School of Medicine (UNM SOM) regarding mentorship and developmental networks. Within their first year of hire, all newly hired faculty at UNM SOM are required to participate in a two-day orientation to the institution event called 'Quikstart.' During seven such events, new faculty [N=131] were surveyed anonymously on six single-response questions about their attitudes regarding mentorship and developmental networks, administered via online polls between September 2018 and July 2022. In this descriptive study, summary characteristics were analyzed. Newly hired faculty mentees reported that creating a developmental network was hampered by difficulties finding multiple mentors (55.3%), receiving conflicting advice from multiple mentors (22.4%), and gathering many mentors at the same location at the same time (11.8% ). Lack of clarity regarding faculty mentee needs (55.5%), mentors' unavailability (17.6%), and failure to find mentors (14.3%) were the most often mentioned difficulties during the initiation stage of mentorship (Hitchcock et al., 1995). Although the literature advocates moving from hierarchical dyadic mentoring relationships to developmental networks, this transition for Medicine faculty mentees will likely be hindered by a shortage of adequately trained mentors. Institutions need to identify and train mentors, incentivize and support mentorship, and encourage the creation and maintenance of self-selected development networks, possibly under the leadership of a transitional mentor.

DADApy: Distance-based analysis of data-manifolds in Python

DADApy is a Python software package for analyzing and characterizing high-dimensional data manifolds. It provides methods for estimating the intrinsic dimension and the probability density, for performing density-based clustering, and for comparing different distance metrics. We review the main functionalities of the package and exemplify its usage in a synthetic dataset and in a real-world application. DADApy is freely available under the open-source Apache 2.0 license.

Eurasiaplex-2: Shifting the focus to SNPs with high population specificity increases the power of forensic ancestry marker sets

To compile a new South Asian-informative panel of forensic ancestry SNPs, we changed the strategy for selecting the most powerful markers for this purpose by targeting polymorphisms with near absolute specificity - when the South Asian-informative allele identified is absent from all other populations or present at frequencies below 0.001 (one in a thousand). More than 120 candidate SNPs were identified from 1000 Genomes datasets satisfying an allele frequency screen of ≥ 0.1 (10 % or more) allele frequency in South Asians, and ≤ 0.001 (0.1 % or less) in African, East Asian, and European populations. From the candidate pool of markers, a final panel of 36 SNPs, widely distributed across most autosomes, were selected that had allele frequencies in the five 1000 Genomes South Asian populations ranging from 0.4 to 0.15. Slightly lower average allele frequencies, but consistent patterns of informativeness were observed in gnomAD South Asian datasets used to validate the 1000 Genomes variant annotations. We named the panel of 36 South Asian-specific SNPs Eurasiaplex-2, and the informativeness of the panel was evaluated by compiling worldwide population data from 4097 samples in four genome variation databases that largely complement the global sampling of 1000 Genomes. Consistent patterns of allele frequency distribution, which were specific to South Asia, were observed in all populations in, or closely sited to, the Indian sub-continent. Pakistani populations from the HGDP-CEPH panel had markedly lower allele frequencies, highlighting the need to develop a statistical system to evaluate the ancestry inference value of counting the number of population-specific alleles present in an individual.

Nurse and general practioner-led up-titration strategy: a real world experience in a heart failure unit in colombia

Funding Acknowledgements

Type of funding sources: None.

Background

Despite improvement of heart failure (HF) prescription rates, doses prescribed in clinical practice are lower than those achieved in randomized clinical trials. Nurse-led up-titration strategy has been widely used in Europe with promising results. Nevertheless, there is no evidence of this approach in Latin America.

Methods

A prospective cohort study was conducted in 50 patients with reduced ejection fraction to evaluate efficacy and safety of nurse and general practioner(GP)-led up-titration protocol, based on problem solving from the European Society of Cardiology HF guidelines. Patients were admitted in our HF unit from January 2017 to December 2019. After discharge our clinical pathway provides 3 types of visits : Cardiologist visits, educational visits and titration visits with GP and registered nurse. Along intervention the registered nurse lead flexible diuretic titration and structured phone monitoring calls.

Results

Baseline characteristics are showed in Table 1. Mean age was 72.5 years, 50% of patients were women, 66% had ischemic cardiomiopathy, mean N-terminal pro-B-type natiuretic peptide was 3285pg/dl, and 58% of patients were NYHA class III. At 97 days with an average of 4 up-titration visits disease-modifying drugs titration was completed. At the beginning 98% of patients had Beta Blockers (BB) , 98% had Mineralocorticoid Receptor Antagonist (MRA), and all of them had Angiotensin Converting Enzyme Inhibitors, angiotensin receptor blockers or Angiotensin Receptor Neprilysin Inhibitor (ARNI). According to the guidelines Angiotensin Converting Enzyme Inhibitors and angiotensin receptor blockers were replaced by ARNI in symptomatic patients. At the end of titration, BB target dose was achieved for 44% of patients, intermediate dose for 46% and final low dose for only 10% of patients. Ivabradine was added for 22% of patients. MRA intermediate and high doses were achieved for 82,5% of patients. Target dose of ARNI was achieved for 62% of patients, intermediate dose for 22% and only 20% of patients remained in starting dose. On average ARNI target dose was completed at 56 days. According to our protocol three patients stopped MRA due to hyperkalemia and symptomatic hypotension was the main cause for stopping up-titration. There was a relationship between patient´s caregiver and higher doses of ARNI( p=0.624) and BB (p=0.421).

Conclusion

A nurse and GP directed up-titration protocol is an encouraging strategy in HF units to achieve the recommended doses of disease-modifying drugs according to the guidelines.

P-404 Usability, accuracy and cost-effectiveness of “eDiagEPU”, a medical software for early pregnancies: a retrospective study

Study question

Can early pregnancies be accurately and cost-effectively diagnosed and managed using a new medical computerised tool, named “eDiagEPU”?

Summary answer

Compared to the standard clinical approach, the retrospective implementation of “eDiagEPU” in a gynaecological emergency unit was correlated with sharper diagnoses and more cost-effective managements.

What is known already

Early pregnancies complications are responsible for a large percentage of consultations, mostly in emergency units. Moreover, clinical guidelines updates for the management of Intrauterine Pregnancies of Uncertain Viability (IPUV) have become increasingly complex and seem to be unknown or misunderstood by several practitioners. Specifically, a recently published prospective multinational survey revealed a limited knowledge regarding early pregnancy guidelines, with 69.0% of the participants reporting incorrect managements of IPUV and 86.6% misinterpreting the evolution of serum human chorionic gonadotropin (hCG).

In an attempt to aid practitioners with the diagnosis and management of early pregnancies, a software, named “eDiagEPU”, was developed.

Study design, size, duration

A total of 780 consultations, recorded between November 2018 and June 2019 in the gynaecological emergency unit of a tertiary university hospital, were retrospectively encoded in eDiagEPU. Positive hCG, ultrasonographical visualisation of gestational sac or/and embryo corresponding to a gestational age of 14 weeks gestation or less were the inclusion criteria.

Diagnoses and managements suggested by eDiagEPU are named “eDiagnoses”. The ones provided by a gynaecologist member of the emergency department staff are called “medDiagnoses”.

Participants/materials, setting, methods

Identical eDiagnosis and medDiagnosis were considered as correct (gold standard). During follow-up examinations, if they became both identical to a previous discrepant eDiagnosis or medDiagnosis, this previous eDiagnosis/medDiagnosis was considered as correct. Persistent discrepancies were reviewed by four double-blinded experts whose majority defined the correct eDiagnosis/medDiagnosis.

The accuracies of eDiagnoses/medDiagnoses were compared using McNemar’s Chi square test, computing diagnostic values (Sensitivity, Specificity, and predictive values) and 95% Confidence Intervals (CI). Cost reduction was also analysed.

Main results and the role of chance

Only one datum (0.1%) from 780 registered medical records was missing to process using “eDiagEPU”. Out of the 779 consultations that could be fully encoded until obtaining an eDiagnosis, 675 eDiagnoses were identical to the medDiagnoses (86.6%) and 104 discrepant (13.4%). From these 104, 60 reached an agreement during follow-up controls with 59 medDiagnoses finally changing into the initial eDiagnoses (98%) while only one discrepant eDiagnosis turning later into the initial medDiagnosis (2%). Finally, 24 remained discrepant at all subsequent checks and 20 were not reevaluated. Out of these 44 discrepancies without identical diagnoses/managements during follow-up controls, the double-blinded experts majority chose 38 eDiagnoses (86%) and 5 medDiagnoses (11%) including 4 twin pregnancies whose twinness was the only discrepancy. One discrepant eDiagnosis/medDiagnosis reached no majority (2%).

In total, eDiagnoses accuracy was 99.1% (675 + 59 + 38=772 eDiagnoses out of 779 final diagnoses), vs 87.4% (675 + 1 + 5=681) for medDiagnoses accuracy (p &lt; 0.0001). Calculating all basic costs of consultations, medications, surgeries and hospitalisations induced by medDiagnoses versus eDiagnoses, “eDiagEPU” would have saved 3 623.75 € per month.

Retrospectively, “eDiaEPU” was usable (99.9%), more accurate for each diagnosis except twinning report and more cost-effective than standard clinical approach.

Limitations, reasons for caution

The retrospective design is a limitation, as well as the quality of ultrasound interpretation. Some improvements could not derive exclusively from “eDiagEPU” but also from the encoding by a rested or more experienced physician. This software cannot replace clinical and ultrasonographical skills but can improve the diagnostic and therapeutic reasoning.

Wider implications of the findings

An improved “eDiagEPU” version, considering the diagnosis and management of multiple pregnancies with their specificities (potentially multiple locations, chorioamnionicity) has been developed. Prospective evaluations will be required. Further development steps are considered, including software incorporation into ultrasound devices and integration of previously published predictive/prognostic factors (serum progesterone, corpus luteum scoring...).

Trial registration number

NCT03993015

P-211 Significant differences in efficiency between two commonly used ionophore solutions for assisted oocyte activation (AOA): a prospective comparison of ionomycin and A23187

Study question

Are there differences in oocyte activation rate and developmental morphokinetic after assisted oocyte activation (AOA) with either ionomycin or A23187?

Summary answer

Ionomycin produces greater oocyte activation rate than A23187 (43.1% vs 15.9%), while the morphokinetic pattern of parthenotes’ development is similar between both Ca2+ ionophores.

What is known already

Fertilization failure (FF) after ICSI is often due to a male factor, such as the alteration of sperm-borne oocyte activating factors or globozoospermia. AOA can restore fertilization rate by stimulating transient spikes of Ca2+ in the cytoplasm of the oocyte, but its efficiency and effect on embryo development are not fully characterized. Here, the efficiency of two AOA preparation and protocols commonly used in clinical practice is compared using parthenogenetically activated human oocytes. The objective is to identify the most appropriate protocol for AOA and to compare the morphokinetic pattern of the generated parthenotes up to expanded blastocyst (tB).

Study design, size, duration

Prospective study involving 120 human oocytes from 66 women from March 2019 to November 2021. Oocytes were activated with two AOA protocols after mock ICSI: i) A23187 (ready-to-use solution, GM508 CultActive (Gynemed) n = 69), and ii) Ionomycin (homemade solution, 10 µmol/L, n = 51). Oocyte activation and development were analyzed in both groups; further, the morphokinetic patterns were compared; videos of embryos obtained with donor oocytes and sperm (n = 39) were used as comparator of normal developmental kinetics.

Participants/materials, setting, methods

Oocytes were injected with latex microspheres to simulate ICSI, followed by AOA. A23187 was used according to manufacturer specification. For ionomycin, three incubations of seven minutes each were performed. Resulting parthenotes (1PN) were incubated in a time-lapse system for 160h. Activation and developmental rates, tPNf (pronucleus fading), t2, t3, t4, t5, t8 (from 1st division to 8-cell), tsB (blastulation onset) and tB (blastocyst expansion) were compared using Student’s T-test and ANOVA. Statistical significance: p-value &lt;0.05.

Main results and the role of chance

Ionomycin resulted in a significantly higher oocyte activation rate (22/51, 43.1%) than A23187 (11/69, 15.9%), p = 0.0009. In the ionomycin group, 81.8% (18/22) of parthenotes reached the 2-cell stage, 45.5% (10/22) reached the 5-cell stage, and 18.2% (4/22) reached the pseudo-blastocyst stage, as expected for these pseudo-embryos lacking the contribution of the sperm. In the A23187 group, 54.5% (6/11) reached the 2-cell stage, 27.3% (3/11) the 5-cell stage, and none formed pseudo-blastocysts. While the number of parthenotes progressing through development is much lower for A23187, the expected poor development of human parthenotes past activation and corresponding low numbers did not allow to reach statistical significance (p &gt; 0.05). tPNf was significantly different among the 3 groups compared: 47.4±37.5h (n = 11, A23187), 27.7±23.8h (n = 21, ionomycin) and 23.3±4.6h (n = 39, control), p = 0.0019; with ionomycin presenting an average tPNf similar to the one obtained by ICSI. Among activated oocytes, the morphokinetic pattern in the ionomycin and A23187 groups was very similar to the one obtained in the control group (p &gt; 0.05 at all timings). As an example, the t5 in the 3 groups was 58.5±12.6h (n = 3, A23187), 45.6±21.8h (n = 10, ionomycin), and 49.5±12.4h (n = 34, control), p = 0.29.

Limitations, reasons for caution

The low number of parthenotes progressing past 2-cells limit the possibility to extract solid conclusions regarding the morphokinetic patterns after AOA. The efficiency of activation using the two tested protocol is however confirmed.

Wider implications of the findings

The use of homemade ionomycin solutions is an effective option for the treatment of fertilization failures where assisted oocyte activation is indicated. Caution should be exerted when using GM508 Cultactive to investigate fertilization failures of oocyte origin.

Trial registration number

not applicable

Phonemic fluency in post-ICU patients after severe COVID-19 infection: The role of cognitive reserve

Introduction

Cognitive function may be impaired in COVID-19 patients, especially in executive functions such as phonemic fluency. Among risk factors, inflammation during hospitalization is related with worse cognitive performance in the long term. On the other side, it has been shown that cognitive reserve (CR) protects against cognitive impairment associated with brain damage, psychiatric disorders and neurodegenerative diseases.

Objectives

Our aim is to study the protective role of cognitive reserve in phonemic fluency to inflammation after SARS-CoV-2 infection.

Methods

We enrolled a cohort of 102 severe SARS-CoV-2 survivors after Intensive Care Unit (ICU) discharge and 58 agreed to participate in this 6-month follow-up study. Patients with previously known cognitive impairment were excluded. Demographic, clinical and laboratory data were collected. To assess the phonemic fluency, we used the Controlled Oral Word Association Test (COWAT) controlling the effects of age and education. Inflammation was recorded according to the number of days with high CRP. ANCOVA analyses were used to test the effect of interaction between medical variables and cognitive reserve on phonemic fluency.

Results

The COVID-19 inflammation interacted with CR in phonemic fluency (F= 6.47, p= 0.01), with worse performance in patients with low CR (mean 16.7 (10.2-23.3)) than those with high CR (mean 37.7 (34.3-41.2)) in function of number of days with high PCR during ICU stay.

Conclusions

The role of the cognitive reserve is important to reduce the cognitive impairment related with COVID-19 inflammation in post-ICU patients.

Disclosure

No significant relationships.

Repeat cryoablation as a redo procedure for atrial fibrillation ablation: Is it a good choice?

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic Inc.

Introduction

Catheter ablation of atrial fibrillation, both cryoablation and radiofrequency pulmonary vein isolation, have demonstrated to be safe and effective techniques for treating symptomatic atrial fibrillation as a first procedure. However, about one in three patients may face a redo procedure due to AF recurrence. The most suitable technique for redo is unknown.

Purpose

The aim of this study is to assess the efficacy of cryoballoon AF ablation as a redo technique in patients with prior cryoballoon or radiofrequency AF ablation.

Methods

We analyzed a nation-wide real-world cryoablation registry (RECABA) and compared patients who were referred for a first cryoballoon AF ablation procedure with those who had previously undergone cryoballoon or radiofrequency pulmonary vein isolation. The primary endpoint was AF recurrence during the first year after a 3-month blanking period. We performed survival analysis and built univariate and multivariate cox regression models.

Results

From 1742 patients, 1625 had a 12-month follow-up visit. 1551 (95.45%) underwent a first cryoballoon ablation, whereas 33 (2.03%) had a previous CB ablation performed and 41 (2.52%) a previous RF ablation.

Mean age was 58.6 ±10.4 years and 511 (31.5%) were women. 463 (28.5%) had persistent atrial fibrillation and there were no major clinical differences between groups.

Prior-CB group had a higher share of veins without electrogram visualization, with a median of 100% (IQR 75%-100%), compared to prior-RF group (median 67%, IQR 25%-75%) and first procedure group (median 25%, IQR 0%-50%). Kruskal-Wallis test Chi2=54.35, p&lt;0.0001.

12-month Kaplan–Meier estimate of freedom from AF recurrence after the blanking period was 78.5% (95% CI 76.2% - 80.7%) in the first procedure group, 61.0% (95% CI 41.4% - 75.8%) in the prior-CB and 89.2% (95% CI 73.6% - 95.9%) in the prior-RF group. Log-rank test Chi2=17.49, p&lt;0.0001.

Multivariate cox regression analysis pointed female sex, persistent AF, and prior-CB ablation as independent predictors of AF recurrence. The adjusted HR for AF recurrence of prior-CB ablation vs first-CB ablation was 3.13 (95% CI 1.82 -5.40) and for prior-RF vs first CB-ablation was 1.01 (95% CI 0.51 – 1.97).

Conclusion

Repeat cryoballoon AF ablation shows higher rates of AF recurrences compared to first CB procedures or after prior RF ablation. These data suggest that patients with AF recurrence after CB-ablation have worse arrhythmic outcomes and may benefit from other ablation techniques after a recurrence.

A complete pedigree-based graph workflow for rare candidate variant analysis

Methods that use a linear genome reference for genome sequencing data analysis are reference-biased. In the field of clinical genetics for rare diseases, a resulting reduction in genotyping accuracy in some regions has likely prevented the resolution of some cases. Pangenome graphs embed population variation into a reference structure. Although pangenome graphs have helped to reduce reference mapping bias, further performance improvements are possible. We introduce VG-Pedigree, a pedigree-aware workflow based on the pangenome-mapping tool of Giraffe and the variant calling tool DeepTrio using a specially trained model for Giraffe-based alignments. We demonstrate mapping and variant calling improvements in both single-nucleotide variants (SNVs) and insertion and deletion (indel) variants over those produced by alignments created using BWA-MEM to a linear-reference and Giraffe mapping to a pangenome graph containing data from the 1000 Genomes Project. We have also adapted and upgraded deleterious-variant (DV) detecting methods and programs into a streamlined workflow. We used these workflows in combination to detect small lists of candidate DVs among 15 family quartets and quintets of the Undiagnosed Diseases Program (UDP). All candidate DVs that were previously diagnosed using the Mendelian models covered by the previously published methods were recapitulated by these workflows. The results of these experiments indicate that a slightly greater absolute count of DVs are detected in the proband population than in their matched unaffected siblings.

High-Dimensional Fluctuations in Liquid Water: Combining Chemical Intuition with Unsupervised Learning

The microscopic description of the local structure of water remains an open challenge. Here, we adopt an agnostic approach to understanding water's hydrogen bond network using data harvested from molecular dynamics simulations of an empirical water model. A battery of state-of-the-art unsupervised data-science techniques are used to characterize the free-energy landscape of water starting from encoding the water environment using local atomic descriptors, through dimensionality reduction and finally the use of advanced clustering techniques. Analysis of the free energy under ambient conditions was found to be consistent with a rough single basin and independent of the choice of the water model. We find that the fluctuations of the water network occur in a high-dimensional space, which we characterize using a combination of both atomic descriptors and chemical-intuition-based coordinates. We demonstrate that a combination of both types of variables is needed in order to adequately capture the complexity of the fluctuations in the hydrogen bond network at different length scales both at room temperature and also close to the critical point of water. Our results provide a general framework for examining fluctuations in water under different conditions.

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Resolvin D2 promotes host defense in a 2 - hit model of sepsis with secondary lung infection

In the development of sepsis, there is early, massive inflammation which can lead to multiple organ failure. Later there is an immunosuppressed phase where the host is susceptible to secondary infections or is unable to clear existing infection. Specialized Pro-resolving Mediators (SPMs) are endogenously produced lipids which resolve infection by decreasing bacteria load and reducing systemic inflammatory response. There has been little work studying if SPMs given late, can promote host defense. We examined if an SPM, Resolvin D2 (RvD2) could promote host defense in a 2-hit mouse model of cecal ligation and puncture (CLP) sepsis and secondary Pseudomonas aeruginosa lung infection. RvD2 given 48 h after mild CLP (1st hit), increased gene expression of Toll-like receptor-2 (TLR-2) and alveolar macrophage/monocyte phagocytic ability compared to CLP mice given saline vehicle. In this model, RvD2 did not affect plasma IL-6 or IL-10. These effects induced by RvD2, lowered lung bacterial load and decreased mortality after the secondary infection of Pseudomonas aeruginosa (2nd hit). Splenic T-cell numbers were also increased in RvD2 treated mice compared to saline vehicle treated animals. The results suggest that RvD2 promoted mechanisms of host defense in a 2-hit model sepsis and secondary lung infection.

Computational Evolution Protocol for Peptide Design

Computational peptide design is useful for therapeutics, diagnostics, and vaccine development. To select the most promising peptide candidates, the key is describing accurately the peptide-target interactions at the molecular level. We here review a computational peptide design protocol whose key feature is the use of all-atom explicit solvent molecular dynamics for describing the different peptide-target complexes explored during the optimization. We describe the milestones behind the development of this protocol, which is now implemented in an open-source code called PARCE. We provide a basic tutorial to run the code for an antibody fragment design example. Finally, we describe three additional applications of the method to design peptides for different targets, illustrating the broad scope of the proposed approach.

A Comprehensive, FAIR File Format for Neuroanatomical Structure Modeling

With advances in microscopy and computer science, the technique of digitally reconstructing, modeling, and quantifying microscopic anatomies has become central to many fields of biological research. MBF Bioscience has chosen to openly document their digital reconstruction file format, the Neuromorphological File Specification, available at www.mbfbioscience.com/filespecification (Angstman et al., 2020). The format, created and maintained by MBF Bioscience, is broadly utilized by the neuroscience community. The data format's structure and capabilities have evolved since its inception, with modifications made to keep pace with advancements in microscopy and the scientific questions raised by worldwide experts in the field. More recent modifications to the neuromorphological file format ensure it abides by the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles promoted by the International Neuroinformatics Coordinating Facility (INCF; Wilkinson et al., Scientific Data, 3, 160018,, 2016). The incorporated metadata make it easy to identify and repurpose these data types for downstream applications and investigation. This publication describes key elements of the file format and details their relevant structural advantages in an effort to encourage the reuse of these rich data files for alternative analysis or reproduction of derived conclusions.

UV/Vis absorption spectroelectrochemistry of folic acid

UV/Vis absorption spectroelectrochemistry is a very promising analytical technique due to the complementary information that is simultaneously obtained from electrochemistry and spectroscopy. In this work, this technique is used in a parallel configuration to study the oxidation of folic acid in alkaline medium. Herein, UV/Vis absorption spectroelectrochemistry has been used to detect both the oxidation products and the folic acid consumed at the electrode/solution interface, allowing us to develop an analytical protocol to quantify vitamin B9 in pharmaceutical tablets. Linear ranges of three orders of magnitude have been achieved in basic medium (pH = 12.9), obtaining high repeatability and low detection limits. The spectroelectrochemical determination of folic acid in pharmaceutical tablets at alkaline pH values is particularly interesting because of the changes that occur in the optical signal during the electrochemical oxidation of FA, providing results with very good figures of merit and demonstrating the utility and versatility of this hyphenated technique, UV/Vis absorption spectroelectrochemistry.

Clinical risk factors for early mortality in patients with community-acquired septic shock. The importance of adequate source control

OBJECTIVE

To evaluate the incidence and risk factors for early mortality (EM) in the ICU in patients with community-acquired septic shock (CASS).

DESIGN

A retrospective cohort study of patients with CASS admitted to the ICU (2003-2016).

SETTING

ICU at a University Hospital in Spain.

PATIENTS

All consecutive patients admitted to the ICU with CASS.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

CASS was defined according to the Sepsis-3 definitions. EM were defined as occurring within of 72h following ICU admission. A multinomial logistic regression analysis was performed to identify the risk factors associated with early deaths.

RESULTS

During the study period, 625 patients met the Sepsis-3 criteria and admitted with CASS. 14.4% of all patients died within the first 72h. Of 161 patients who died in the ICU, 90 (55.9%) died within the first 72h. The percentage of early and late mortality did not vary significantly during the study period. The need and adequacy of source control were significantly lower in patients with EM. In the multivariate analysis, ARDS, non-respiratory infections, bacteremia and severity at admission were variables independently associated with EM. The only factor that decreased EM was adequate source control in patients with infections amenable to source control.

CONCLUSIONS

The incidence of EM has remained stable over time, which means that more than half of the patients who die from CASS do so within the first 72h. Infections where adequate source control can be performed have lower EM.

Co-designing a training package to promote health/oral health for people experiencing homelessness

Background

In Scotland, 31,333 households were assessed as experiencing homelessness in 2019/20. This population present high morbidity and mortality which is a public health issue. Their health needs have been identified within Scottish policy as part of the broad goal of reducing inequalities and poverty. Those experiencing homelessness face multiple exclusions that must be addressed by practitioners from all health and social care sectors. Frontline staff have identified they often do not have adequate information and/or training on wider health issues linked with their client's needs. The aim of this research is to co-produce training resources to support front-line staff to discuss and to promote health and oral health.

Methods

Community-based participatory research that used online workshops to listen to the views of people with lived experience, practitioners and students from health and third sector, and policy makers regarding accessibility of services and practitioner approach towards those experiencing homelessness. Content analysis will be used to identified recurrent themes.

Results

The preliminary findings shown that lack of empathy from practitioners, continuity of care and stigma are barriers to access services. This is informing a co-designed knowledge exchange training packaged to help practitioners to improve knowledge and ability to promote health/oral health and to engage with people experiencing homelessness or at risk of becoming homeless. Educational materials (e-book on health promotion, comics books on barriers to access services, and a guide to promote oral health) compose this training package.

Conclusions

The training package allows adaptations to different settings and contexts and will be an important resource to be used by practitioners from different fields to prevent and tackle homelessness. Participants are sharing important views related to the need of a human rights and social justice-based approach to health promotion.

Key messages

Development of a co-designed knowledge exchange training package to improve practitioners' knowledge and ability to communicate and to engage with people experiencing homelessness. To empower people experiencing homelessness regarding positive health/oral health behavior change.

Healthcare needs of young people transitioning back to the community after a custodial sentence

Background

People in prison have poorer health outcomes than the general population, added by the long-term impact of incarceration on mortality. Young people in custody face extra challenges associated with the stage of development. There is a lack of a tailored approach and policy to young people when transitioning back to the community. This paper draws from a PhD research that looked at the challenges to access healthcare during the transition back to the community. The specific question is: What are young people's healthcare needs when released from custodial sentences?

Methods

An ethnographic study conducted in Scotland in partnership with a community-based organisation. The participants were eight young people and ten practitioners that work in health and social care. Participatory observation and in-depth interviews were used to collect data during July 2019 and March 2020. Data analysis was conducted with Reflexive thematic analysis. NVivo supported data management.

Results

The identified needs were individualised issues, structural factors, mental health, substance use and geographical disposition of services. There is a need for mental support and continuity of care associated with substance use. The demand for local services is vital for healthcare provision. Healthcare needs go beyond the necessity of services and health issues. They are associated with stigma in the interaction with practitioners. Institutional practices and practitioners' attitudes reinforce non-explicit forms of discrimination and health inequalities.

Conclusions

Practitioners and policymakers need to focus on the person-centred approach. They need to listen to young people. Data showed a need for specific services, like mental health and drug use. Moreover, practitioners need to avoid stigmatisation and discrimination by a caring practice. Public health and social care policies need to address stigma and access to services for young people after a custodial sentence.

Key messages

It is necessary to avoid stigmatisation and improve access to services for young people transitioning back to the community after a custodial sentence. Public Health and social care policies need to address this marginalised group by offering person-centred approaches, continuity of care and support during re-entry.

Altered atrial restitution dynamics and refractoriness in metabolic syndrome due to up-regulation of potassium repolarizing currents increases susceptibility to atrial fibrillation

Background

Metabolic alterations, such as Metabolic Syndrome (MS), describe an association of factors including diabetes, hypertension, obesity and dyslipidemia, linked to higher risk and prevalence of overall cardiovascular disease, arrhythmogenesis and sudden cardiac death. Obese and diabetic patients have shown an increased risk for developing atrial fibrillation (AF). However, underlying mechanisms are not understood.

Purpose

To study the effects of MS and obesity remodeling in atrial restitution dynamics, frequency-dependent adaptation, refractoriness and its potential susceptibility to AF.

Methods

Electrophysiological experimental data from High-fat (HF-O, standard rabbit chow with an additional 15% fat) and Hig-fat High-Sucrose Metabolic Syndrome (HFHS-MS, 10% hydrogenated coconut oil and 5% lard, 15% high-sucrose dissolved in water) rabbit models were used to adjust computational models atrial electrophysiology remodeling under each condition. Additionally, isoproterenol and AF conditions were considered to challenge both in-silico models. Validation and sensitivity analysis were performed for each model parameters. Computational simulations in conditions of pacing at different pacing cycle lengths was assessed at 100, 125, 150, 200, 250, 350, 450, 500, 650, 750, 850, 1000 ms. Restitution dynamics were automatically determined and analyzed, as well as restitution slopes and presence of automaticity, early after-depolarizations, alternans and cardiac arrhythmia induction.

Results

Shortening of action potential duration and refractoriness in the left atrium was observed under HFHS-MS. Upstroke velocity, maximum excitability and sodium availability were altered both in HF-O and HFHS-MS. HF-O remodeling showed presence of alternans at high pacing frequencies. Repolarization restitution was shortened in conditions of ISO and MS-AF. Restitution slopes were &gt;1 in HF-O and HFHS-MS, which was correlated to higher susceptibility to AF, and further increased in MS-AF. Under MS-AF, abbreviation in APD in both atria, resulted in increased reentrant frequencies in AF, which was exacerbated under IK1 up-regulation, increasing atrial vulnerability.

Conclusions

HFHS-MS underlies modifications in atrial electrophysiology including shorter refractoriness in HFHS-MS, as well as modifications in atrial excitability, which may be pro-arrhythmic mainly at high frequency rates. This could be explained in part by an up-regulation of outward potassium channels. These results could partially explain increased susceptibility for AF in MS.

Funding Acknowledgement

Type of funding sources: None.

Long-term outcomes among a cohort of 4296 implantable cardioverter-defibrillator patients: insights from the UMBRELLA study

Background

Large observational real-world studies describing modern implantable cardioverter-defibrillator (ICD) populations with long-term follow-up are lacking.

Purpose

To assess the incidence of arrhythmias in a cohort of contemporary patients undergoing ICD implant from 2005 and 2017 and to analyze the arrhythmic risk and mortality according to their clinical profiles.

Methods

UMBRELLA (NTC01561144) is a prospective, multicentre, nationwide study of ICD patients followed by remote monitoring. All device information was automatically stored through the remote monitoring system and a blinded review of all the stored arrhythmic episodes was performed. The study outcomes were first appropriate ICD therapy and all-cause death.

Results

The study population consisted of 4296 patients (61.9±12.9 years, ischaemic cardiomyopathy (ICM): n=2150, dilated cardiomyopathy (DCM): n=1166, valvular heart disease (VHD): n=119, hypertrophic cardiomyopathy (HCM): n=294, arrhythmogenic right ventricular cardiomyopathy (ARVC): n=71, Brugada syndrome (BS): n=143, long QT syndrome (LQTS): n=43, and adult congenital heart disease (ACHD): n=60)). Primary prevention (PP) was the main indication (n=2758).

During a mean follow-up of 46.6±27.3 months, 16,067 episodes of sustained ventricular arrhythmia (SVA) occurred in 1344 patients. Appropriate ICD therapy was delivered to 85.7% (n=13,767) episodes of SVA in 1173 patients (27.3% of population). A higher risk of first appropriate ICD therapy was observed in VHD (HR: 1.94, 95% CI: 1.43–2.62), ARVC (HR: 1.84, 95% CI: 1.28–2.66), ICM (HR: 1.51, 95% CI: 1.29–1.78), and DCM (HR: 1.28, 95% CI: 1.07–1.53) whereas patients with HCM (HR: 0.72, 95% CI: 0.54–0.96) and BS (HR: 0.25, 95% CI: 0.14–0.45) were at significantly lower risk (Figure 1A). In multivariate analysis (Table 1), age, gender, atrial fibrillation (AF), secondary prevention, LVEF ≤35%, and QRS width emerged as clinical predictors of appropriate ICD therapy, whereas CRT-D correlated with lower risk. An independently higher risk was found in DCM, VHD, and ARVC, and a lower risk in BS patients.

At follow-up, 590 deaths (13.4% of population) were reported. Patients with ICM (HR 3.90, 95% CI: 2.58–5.90), DCM (HR 3.33, CI 95%: 2.18–5.10), and VHD (HR 3.97, CI 95%: 2.25–6.99) had worse prognoses and it was significantly better in BS patients (HR 0.11, 95% CI: 0.01–0.67, p=0.017) (Figure 1B). In multivariate analysis, age, gender, AF, renal failure, diabetes and reduced LVEF, emerged as independent predictors of all-cause death (Table 1).

Conclusions

Irrespective of the aetiology, contemporary ICD patients with an arrhythmic substrate derived from left ventricular systolic dysfunction had a similar risk of ICD life-saving interventions and death.

Funding Acknowledgement

Type of funding sources: None. Table 1Figure 1