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Motivated by the need to harness the properties of renewable and biodegradable polymers for the design and manufacturing of multi-scale structures with complex geometries, we have employed our additive manufacturing platform that leverages molecular self-assembly for the production of metre-scale structures characterized by complex geometries and heterogeneous material composition. As a precursor material, we used chitosan, a chemically modified form of chitin, an abundant and sustainable structural polysaccharide. We demonstrate the ability to control concentration-dependent crystallization as well as the induction of the preferred orientation of the polymer chains through the combination of extrusion-based robotic fabrication and directional toolpathing. Anisotropy is demonstrated and assessed through high-resolution micro-X-ray diffraction in conjunction with finite element simulations. Using this approach, we can leverage controlled and user-defined small-scale propagation of residual stresses to induce large-scale folding of the resulting structures.
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BACKGROUND: Patients with angina and non-obstructive coronary arteries (ANOCA) frequently have coronary vasomotor disorders (CVaD), characterised by transient pathological vasoconstriction and/or impaired microvascular vasodilatation. Functional coronary angiography is the gold standard for diagnosing CVaD. Despite recommendations, testing is only available at a limited number of Australian and New Zealand centres. This study aimed to determine the prevalence of CVaDs in an Australian ANOCA population and identify predictive factors associated with specific endotypes. METHOD: Functional coronary angiography was performed in patients with suspected ANOCA. Vasoreactivity testing was performed using intracoronary acetylcholine provocation. A pressure-temperature sensor guidewire was used for coronary physiology assessment. Comprehensive clinical data on patient characteristics, cardiac risk factors, and symptom profiles was collected before testing. RESULTS: This prospective observational study at Royal Prince Alfred and Concord Repatriation General Hospital included 110 patients (58±13 years with 63.6% women), with 81.8% (90/110) having a CVaD. Regarding specific ANOCA endotypes, microvascular angina (MVA) occurred in 31.8% (35/110) of cases, vasospastic angina (VSA) in 25.5% (28/110) and a mixed presentation of MVA and VSA in 24.5% (27/110) of patients. Patients with CVaD were found to be older (59±11 vs 51±15, p=0.024), overweight (61.1% vs 15.0%, p<0.001) and had a worse quality of life (EuroQol 5 Dimensions-5 Levels; 0.61 vs 0.67, p=0.043). MVA was associated with being overweight (odds ratio [OR] 4.2 [95% confidence interval [CI] 1.9-9.3]; p=0.015) and ischaemia on stress testing (OR 2.4 [95% CI 1.1-4.3]; p=0.028), while VSA was associated with smoking (OR 9.1 [95% CI 2.21-39.3]; p=0.007). CONCLUSIONS: Coronary vasomotor disorders are highly prevalent among ANOCA patients. This study highlights the importance of increasing national awareness and the use of functional coronary angiography to evaluate and manage this unique cohort.
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BACKGROUND: Invasive CFT is the gold standard for diagnosing coronary vasomotor dysfunction in patients with ANOCA. Most institutions recommend only testing the left coronary circulation. Therefore, it is unknown whether testing multiple coronary territories would increase diagnostic yield. OBJECTIVES: The aim of this study was to evaluate the diagnostic yield of multivessel, compared with single-vessel, invasive coronary function testing (CFT) in patients with angina and nonobstructive coronary arteries (ANOCA). METHODS: Multivessel CFT was systematically performed in patients with suspected ANOCA. Vasoreactivity testing was performed using acetylcholine provocation in the left (20 to 200 µg) and right (20 to 80µg) coronary arteries. A pressure-temperature sensor guidewire was used for coronary physiology assessment in all three epicardial vessels. RESULTS: This multicenter study included a total of 228 vessels from 80 patients (57.8 ± 11.8 years of age, 60% women). Compared with single-vessel CFT, multivessel testing resulted in more patients diagnosed with coronary vasomotor dysfunction (86.3% vs 68.8%; P = 0.0005), coronary artery spasm (60.0% vs 47.5%; P = 0.004), and CMD (62.5% vs 36.3%; P < 0.001). Coronary artery spasm (n = 48) predominated in the left coronary system (n = 38), though isolated right coronary spasm was noted in 20.8% (n = 10). Coronary microvascular dysfunction (CMD), defined by abnormal index of microcirculatory resistance and/or coronary flow reserve, was present 62.5% of the cohort (n = 50). Among the cohort with CMD, 27 patients (33.8%) had 1-vessel CMD, 15 patients (18.8%) had 2-vessel CMD, and 8 patients (10%) had 3-vessel CMD. CMD was observed at a similar rate in the territories supplied by all 3 major coronary vessels (left anterior descending coronary artery = 36.3%, left circumflex coronary artery = 33.8%, right coronary artery = 31.3%; P = 0.486). CONCLUSIONS: Multivessel CFT resulted in an increased diagnostic yield in patients with ANOCA compared with single-vessel testing. The results of this study suggest that multivessel CFT has a role in the management of patients with ANOCA.
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Acetilcolina , Angina Pectoris , Doença da Artéria Coronariana , Circulação Coronária , Vasoespasmo Coronário , Vasos Coronários , Valor Preditivo dos Testes , Vasodilatadores , Humanos , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Vasos Coronários/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Vasodilatadores/administração & dosagem , Vasoespasmo Coronário/fisiopatologia , Vasoespasmo Coronário/diagnóstico , Acetilcolina/administração & dosagem , Angina Pectoris/fisiopatologia , Angina Pectoris/diagnóstico , Angina Pectoris/etiologia , Doença da Artéria Coronariana/fisiopatologia , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Cateterismo Cardíaco , Angiografia Coronária , Reprodutibilidade dos Testes , Vasodilatação , VasoconstriçãoRESUMO
Generating strong rapid adhesion between hydrogels has the potential to advance the capabilities of modern medicine and surgery. Current hydrogel adhesion technologies rely primarily on liquid-based diffusion mechanisms and the formation of covalent bonds, requiring prolonged time to generate adhesion. Here, we present a simple and versatile strategy using dry chitosan polymer films to generate instant adhesion between hydrogel-hydrogel and hydrogel-elastomer surfaces. Using this approach we can achieve extremely high adhesive energies (>3,000 J/m2), which are governed by pH change and non-covalent interactions including H-bonding, Van der Waals forces, and bridging polymer entanglement. Potential examples of biomedical applications are presented, including local tissue cooling, vascular sealing, prevention of surgical adhesions, and prevention of hydrogel dehydration. We expect these findings and the simplicity of this approach to have broad implications for adhesion strategies and hydrogel design.
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Adesivos , Polímeros , Humanos , Aderências Teciduais/prevenção & controle , Adesivos/química , Elastômeros , Hidrogéis/químicaRESUMO
BACKGROUND: Landmark trials showed that invasive pressure measurement (Fractional Flow Reserve, FFR) was a better guide to coronary stenting than visual assessment. However, present-day interventionists have benefited from extensive research and personal experience of mapping anatomy to hemodynamics. AIMS: To determine if visual assessment of the angiogram performs as well as invasive measurement of coronary physiology. METHODS: 25 interventional cardiologists independently visually assessed the single vessel coronary disease of 200 randomized participants in The Objective Randomized Blinded Investigation with optimal medical Therapy of Angioplasty in stable angina trial (ORBITA). They gave a visual prediction of the FFR and Instantaneous Wave-free Ratio (iFR), denoted vFFR and viFR respectively. Each judged each lesion on 2 occasions, so that every lesion had 50 vFFR, and 50 viFR assessments. The group consensus visual estimates (vFFR-group and viFR-group) and individual cardiologists' visual estimates (vFFR-individual and viFR-individual) were tested alongside invasively measured FFR and iFR for their ability to predict the placebo-controlled reduction in stress echo ischemia with stenting. RESULTS: Placebo-controlled ischemia improvement with stenting was predicted by vFFR-group (p < 0.0001) and viFR-group (p < 0.0001), vFFR-individual (p < 0.0001) and viFR-individual (p < 0.0001). There were no significant differences between the predictive performance of the group visual estimates and their invasive counterparts: p = 0.53 for vFFR vs FFR and p = 0.56 for viFR vs iFR. CONCLUSION: Visual assessment of the angiogram by contemporary experts, provides significant additional information on the amount of ischaemia which can be relieved by placebo-controlled stenting in single vessel coronary artery disease.
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Cardiologistas , Doença da Artéria Coronariana , Estenose Coronária , Reserva Fracionada de Fluxo Miocárdico , Humanos , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Vasos Coronários/diagnóstico por imagem , Isquemia , Valor Preditivo dos Testes , Índice de Gravidade de DoençaRESUMO
Restricted movement among populations decreases genetic variation, which may be the case for the Montezuma quail (Cyrtonyx montezumae), a small game bird that rarely flies long distances. In the northern limit of its distribution, it inhabits oak-juniper-pine savannas of Arizona, New Mexico, and Texas. Understanding genetic structure can provide information about the demographic history of populations that is also important for conservation and management. The objective of this study was to determine patterns of genetic variation in Montezuma quail populations using nine DNA microsatellite loci. We genotyped 119 individuals from four study populations: Arizona, Western New Mexico, Central New Mexico, and West Texas. Compared to other quail, heterozygosity was low (H¯0 = 0.22 ± 0.04) and there were fewer alleles per locus (A = 2.41 ± 0.27). The global population genetic differentiation index RST = 0.045 suggests little genetic structure, even though a Bayesian allocation analysis suggested three genetic clusters (K = 3). This analysis also suggested admixture between clusters. Nevertheless, an isolation-by-distance analysis indicates a strong correlation (r = 0.937) and moderate evidence (P = 0.032) of non-independence between geographical and genetic distances. Climate change projections indicate an increase in aridity for this region, especially in temperate ecosystems where the species occurs. In this scenario, corridors between the populations may disappear, thus causing their complete isolation.
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Ecossistema , Variação Genética , Humanos , Animais , Variação Genética/genética , Teorema de Bayes , Genética Populacional , CodornizRESUMO
Antibiotics used systemically to treat infections may have off-target effects on the gut microbiome, potentially resulting in the emergence of drug-resistant bacteria or selection of pathogenic species. These organisms may present a risk to the host and spread to the environment with a risk of transmission in the community. To investigate the risk of emergent antibiotic resistance in the gut microbiome following systemic treatment with antibiotics, this metagenomic analysis project used next-generation sequencing, a custom-built metagenomics pipeline, and differential abundance analysis to study the effect of antibiotics (ampicillin, ciprofloxacin, and fosfomycin) in monotherapy and different combinations at high and low doses, to determine the effect on resistome and taxonomic composition in the gut of Balb/c mice. The results showed that low-dose monotherapy treatments showed little change in microbiome composition but did show an increase in expression of many antibiotic-resistant genes (ARGs) posttreatment. Dual combination treatments allowed the emergence of some conditionally pathogenic bacteria and some increase in the abundance of ARGs despite a general decrease in microbiota diversity. Triple combination treatment was the most successful in inhibiting emergence of relevant opportunistic pathogens and completely suppressed all ARGs after 72 h of treatment. The relative abundances of mobile genetic elements that can enhance transmission of antibiotic resistance either decreased or remained the same for combination therapy while increasing for low-dose monotherapy. Combination therapy prevented the emergence of ARGs and decreased bacterial diversity, while low-dose monotherapy treatment increased ARGs and did not greatly change bacterial diversity.
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Microbioma Gastrointestinal , Microbiota , Animais , Camundongos , Antibacterianos/farmacologia , Ampicilina/farmacologia , Ciprofloxacina/farmacologia , Bactérias/genética , Genes BacterianosRESUMO
Motivated by the need to develop more informative and data-rich patient-specific presurgical planning models, we present a high-resolution method that enables the tangible replication of multimodal medical data. By leveraging voxel-level control of multimaterial three-dimensional (3D) printing, our method allows for the digital integration of disparate medical data types, such as functional magnetic resonance imaging, tractography, and four-dimensional flow, overlaid upon traditional magnetic resonance imaging and computed tomography data. While permitting the explicit translation of multimodal medical data into physical objects, this approach also bypasses the need to process data into mesh-based boundary representations, alleviating the potential loss and remodeling of information. After evaluating the optical characteristics of test specimens generated with our correlative data-driven method, we culminate with multimodal real-world 3D-printed examples, thus highlighting current and potential applications for improved surgical planning, communication, and clinical decision-making through this approach.
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BACKGROUND: Administrative healthcare claims databases are used in drug safety research but are limited for investigating the impacts of prenatal exposures on neonatal and pediatric outcomes without mother-infant pair identification. Further, existing algorithms are not transportable across data sources. We developed a transportable mother-infant linkage algorithm and evaluated it in two, large US commercially insured populations. METHODS: We used two US commercial health insurance claims databases during the years 2000 to 2021. Mother-infant links were constructed where persons of female sex 12-55 years of age with a pregnancy episode ending in live birth were associated with a person who was 0 years of age at database entry, who shared a common insurance plan ID, had overlapping insurance coverage time, and whose date of birth was within ± 60-days of the mother's pregnancy episode live birth date. We compared the characteristics of linked vs. non-linked mothers and infants to assess similarity. RESULTS: The algorithm linked 3,477,960 mothers to 4,160,284 infants in the two databases. Linked mothers and linked infants comprised 73.6% of all mothers and 49.1% of all infants, respectively. 94.9% of linked infants' dates of birth were within ± 30-days of the associated mother's pregnancy episode end dates. Characteristics were largely similar in linked vs. non-linked mothers and infants. Differences included that linked mothers were older, had longer pregnancy episodes, and had greater post-pregnancy observation time than mothers with live births who were not linked. Linked infants had less observation time and greater healthcare utilization than non-linked infants. CONCLUSIONS: We developed a mother-infant linkage algorithm and applied it to two US commercial healthcare claims databases that achieved a high linkage proportion and demonstrated that linked and non-linked mother and infant cohorts were similar. Transparent, reusable algorithms applied to large databases enable large-scale research on exposures during pregnancy and pediatric outcomes with relevance to drug safety. These features suggest studies using this algorithm can produce valid and generalizable evidence to inform clinical, policy, and regulatory decisions.
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Mães , Farmacoepidemiologia , Gravidez , Recém-Nascido , Lactente , Feminino , Humanos , Criança , Gravidez Múltipla , Algoritmos , Atenção à SaúdeRESUMO
The large-scale implementation of renewable energy systems necessitates the development of energy storage solutions to effectively manage imbalances between energy supply and demand. Herein, we investigate such a scalable material solution for energy storage in supercapacitors constructed from readily available material precursors that can be locally sourced from virtually anywhere on the planet, namely cement, water, and carbon black. We characterize our carbon-cement electrodes by combining correlative EDS-Raman spectroscopy with capacitance measurements derived from cyclic voltammetry and galvanostatic charge-discharge experiments using integer and fractional derivatives to correct for rate and current intensity effects. Texture analysis reveals that the hydration reactions of cement in the presence of carbon generate a fractal-like electron-conducting carbon network that permeates the load-bearing cement-based matrix. The energy storage capacity of this space-filling carbon black network of the high specific surface area accessible to charge storage is shown to be an intensive quantity, whereas the high-rate capability of the carbon-cement electrodes exhibits self-similarity due to the hydration porosity available for charge transport. This intensive and self-similar nature of energy storage and rate capability represents an opportunity for mass scaling from electrode to structural scales. The availability, versatility, and scalability of these carbon-cement supercapacitors opens a horizon for the design of multifunctional structures that leverage high energy storage capacity, high-rate charge/discharge capabilities, and structural strength for sustainable residential and industrial applications ranging from energy autarkic shelters and self-charging roads for electric vehicles, to intermittent energy storage for wind turbines and tidal power stations.
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Tunicates are an evolutionarily significant subphylum of marine chordates, with their phylogenetic position as the sister-group to Vertebrata making them key to unraveling our own deep time origin. Tunicates greatly vary with regards to morphology, ecology, and life cycle, but little is known about the early evolution of the group, e.g. whether their last common ancestor lived freely in the water column or attached to the seafloor. Additionally, tunicates have a poor fossil record, which includes only one taxon with preserved soft-tissues. Here we describe Megasiphon thylakos nov., a 500-million-year-old tunicate from the Marjum Formation of Utah, which features a barrel-shaped body with two long siphons and prominent longitudinal muscles. The ascidiacean-like body of this new species suggests two alternative hypotheses for early tunicate evolution. The most likely scenario posits M. thylakos belongs to stem-group Tunicata, suggesting that a biphasic life cycle, with a planktonic larva and a sessile epibenthic adult, is ancestral for this entire subphylum. Alternatively, a position within the crown-group indicates that the divergence between appendicularians and all other tunicates occurred 50 million years earlier than currently estimated based on molecular clocks. Ultimately, M. thylakos demonstrates that fundamental components of the modern tunicate body plan were already established shortly after the Cambrian Explosion.
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Cordados , Urocordados , Animais , Filogenia , Fósseis , Ecologia , Evolução BiológicaRESUMO
Addressing the existing gap between currently available mitigation strategies for greenhouse gas emissions associated with ordinary Portland cement production and the 2050 carbon neutrality goal represents a significant challenge. In order to bridge this gap, one potential option is the direct gaseous sequestration and storage of anthropogenic CO2 in concrete through forced carbonate mineralization in both the cementing minerals and their aggregates. To better clarify the potential strategic benefits of these processes, here, we apply an integrated correlative time- and space-resolved Raman microscopy and indentation approach to investigate the underlying mechanisms and chemomechanics of cement carbonation over time scales ranging from the first few hours to several days using bicarbonate-substituted alite as a model system. In these reactions, the carbonation of transient disordered calcium hydroxide particles at the hydration site leads to the formation of a series of calcium carbonate polymorphs including disordered calcium carbonate, ikaite, vaterite, and calcite, which serve as nucleation sites for the formation of a calcium carbonate/calcium-silicate-hydrate (C-S-H) composite, and the subsequent acceleration of the curing process. The results from these studies reveal that in contrast to late-stage cement carbonation processes, these early stage (precure) out-of-equilibrium carbonation reactions do not compromise the material's structural integrity, while allowing significant quantities of CO2 (up to 15 w%) to be incorporated into the cementing matrix. The out-of-equilibrium carbonation of hydrating clinker thus provides an avenue for reducing the environmental footprint of cementitious materials via the uptake and long-term storage of anthropogenic CO2.
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Implantable tubes, shunts, and other medical conduits are crucial for treating a wide range of conditions from ears and eyes to brain and liver but often impose serious risks of device infection, obstruction, migration, unreliable function, and tissue damage. Efforts to alleviate these complications remain at an impasse because of fundamentally conflicting design requirements: Millimeter-scale size is required to minimize invasiveness but exacerbates occlusion and malfunction. Here, we present a rational design strategy that reconciles these trade-offs in an implantable tube that is even smaller than the current standard of care. Using tympanostomy tubes (ear tubes) as an exemplary case, we developed an iterative screening algorithm and show how unique curved lumen geometries of the liquid-infused conduit can be designed to co-optimize drug delivery, effusion drainage, water resistance, and biocontamination/ingrowth prevention in a single subcapillary-length-scale device. Through extensive in vitro studies, we demonstrate that the engineered tubes enabled selective uni- and bidirectional fluid transport; nearly eliminated adhesion and growth of common pathogenic bacteria, blood, and cells; and prevented tissue ingrowth. The engineered tubes also enabled complete eardrum healing and hearing preservation and exhibited more efficient and rapid antibiotic delivery to the middle ear in healthy chinchillas compared with current tympanostomy tubes, without resulting in ototoxicity at up to 24 weeks. The design principle and optimization algorithm presented here may enable tubes to be customized for a wide range of patient needs.
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Otite Média com Derrame , Humanos , Otite Média com Derrame/diagnóstico , Ventilação da Orelha Média/métodos , Orelha Média/patologia , Próteses e Implantes , AntibacterianosRESUMO
BACKGROUND: Cardiovascular conditions are the most prevalent comorbidity among patients with prostate cancer, regardless of treatment. Additionally, cardiovascular risk has been shown to increase following exposure to certain treatments for advanced prostate cancer. There is conflicting evidence on risk of overall and specific cardiovascular outcomes among men treated for metastatic castrate resistant prostate cancer (CRPC). We, therefore, sought to compare incidence of serious cardiovascular events among CRPC patients treated with abiraterone acetate plus predniso(lo)ne (AAP) and enzalutamide (ENZ), the two most widely used CRPC therapies. METHODS: Using US administrative claims data, we selected CRPC patients newly exposed to either treatment after August 31, 2012, with prior androgen deprivation therapy (ADT). We assessed incidence of hospitalization for heart failure (HHF), ischemic stroke, and acute myocardial infarction (AMI) during the period 30-days after AAP or ENZ initiation to discontinuation, outcome occurrence, death, or disenrollment. We matched treatment groups on propensity-scores (PSs) to control for observed confounding to estimate the average treatment effect among the treated (AAP) using conditional Cox proportional hazards models. To account for residual bias, we calibrated our estimates against a distribution of effect estimates from 124 negative-control outcomes. RESULTS: The HHF analysis included 2322 (45.1%) AAP initiators and 2827 (54.9%) ENZ initiators. In this analysis, the median follow-up times among AAP and ENZ initiators (after PS matching) were 144 and 122 days, respectively. The empirically calibrated hazard ratio (HR) estimate for HHF was 2.56 (95% confidence interval [CI]: 1.32, 4.94). Corresponding HRs for AMI and ischemic stroke were 1.94 (95% CI: 0.90, 4.18) and 1.25 (95% CI: 0.54, 2.85), respectively. CONCLUSIONS: Our study sought to quantify risk of HHF, AMI and ischemic stroke among CRPC patients initiating AAP relative to ENZ within a national administrative claims database. Increased risk for HHF among AAP compared to ENZ users was observed. The difference in myocardial infarction did not attain statistical significance after controlling for residual bias, and no differences were noted in ischemic stroke between the two treatments. These findings confirm labeled warnings and precautions for AAP for HHF and contribute to the comparative real-world evidence on AAP relative to ENZ.
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AVC Isquêmico , Neoplasias de Próstata Resistentes à Castração , Masculino , Humanos , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/epidemiologia , Neoplasias de Próstata Resistentes à Castração/patologia , Antagonistas de Androgênios , Resultado do Tratamento , Acetato de Abiraterona , Nitrilas/efeitos adversosRESUMO
The remarkably complex skeletal systems of the sea stars (Echinodermata, Asteroidea), consisting of hundreds to thousands of individual elements (ossicles), have intrigued investigators for more than 150 years. While the general features and structural diversity of isolated asteroid ossicles have been well documented in the literature, the task of mapping the spatial organization of these constituent skeletal elements in a whole-animal context represents an incredibly laborious process, and as such, has remained largely unexplored. To address this unmet need, particularly in the context of understanding structure-function relationships in these complex skeletal systems, we present an integrated approach that combines micro-computed tomography, automated ossicle segmentation, data visualization tools, and the production of additively manufactured tangible models to reveal biologically relevant structural data that can be rapidly analyzed in an intuitive manner. In the present study, we demonstrate this high-throughput workflow by segmenting and analyzing entire skeletal systems of the giant knobby star, Pisaster giganteus, at four different stages of growth. The in-depth analysis, presented herein, provides a fundamental understanding of the three-dimensional skeletal architecture of the sea star body wall, the process of skeletal maturation during growth, and the relationship between skeletal organization and morphological characteristics of individual ossicles. The widespread implementation of this approach for investigating other species, subspecies, and growth series has the potential to fundamentally improve our understanding of asteroid skeletal architecture and biodiversity in relation to mobility, feeding habits, and environmental specialization in this fascinating group of echinoderms.
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Visualização de Dados , Estrelas-do-Mar , Animais , Estrelas-do-Mar/anatomia & histologia , Estrelas-do-Mar/química , Microtomografia por Raio-X , EquinodermosRESUMO
Effective masking policies to prevent the spread of airborne infections depend on public access to masks with high filtration efficacy. However, poor face-fit is almost universally present in pleated multilayer disposable face masks, severely limiting both individual and community respiratory protection. We developed a set of simple mask modifications to mass-manufactured disposable masks, the most common type of mask used by the public, that dramatically improves both their personalized fit and performance in a low-cost and scalable manner. These modifications comprise a user-moldable full mask periphery wire, integrated earloop tension adjusters, and an inner flange to trap respiratory droplets. We demonstrate that these simple design changes improve quantitative fit factor by 320%, triples the level of protection against aerosolized droplets, and approaches the model efficacy of N95 respirators in preventing the community spread of COVID-19, for an estimated additional cost of less than 5 cents per mask with automated production.
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COVID-19 , Dispositivos de Proteção Respiratória , Humanos , COVID-19/prevenção & controle , Máscaras , Respiradores N95 , FiltraçãoRESUMO
The coronary microcirculation plays a cardinal role in regulating coronary blood flow to meet the changing metabolic demands of the myocardium. Coronary microvascular dysfunction (CMD) refers to structural and functional remodeling of the coronary microcirculation. CMD plays a role in the pathogenesis of obstructive and non-obstructive coronary syndromes as well as myocardial diseases, including heart failure with preserved ejection fraction (HFpEF). Despite recent diagnostic advancements, CMD is often under-appreciated in clinical practice, and may allow for the development of novel therapeutic targets. This review explores the diagnosis and pathogenic role of CMD across a range of cardiovascular diseases, its prognostic significance, and the current therapeutic landscape.
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OBJECTIVE: Observational studies can impact patient care but must be robust and reproducible. Nonreproducibility is primarily caused by unclear reporting of design choices and analytic procedures. This study aimed to: (1) assess how the study logic described in an observational study could be interpreted by independent researchers and (2) quantify the impact of interpretations' variability on patient characteristics. MATERIALS AND METHODS: Nine teams of highly qualified researchers reproduced a cohort from a study by Albogami et al. The teams were provided the clinical codes and access to the tools to create cohort definitions such that the only variable part was their logic choices. We executed teams' cohort definitions against the database and compared the number of subjects, patient overlap, and patient characteristics. RESULTS: On average, the teams' interpretations fully aligned with the master implementation in 4 out of 10 inclusion criteria with at least 4 deviations per team. Cohorts' size varied from one-third of the master cohort size to 10 times the cohort size (2159-63 619 subjects compared to 6196 subjects). Median agreement was 9.4% (interquartile range 15.3-16.2%). The teams' cohorts significantly differed from the master implementation by at least 2 baseline characteristics, and most of the teams differed by at least 5. CONCLUSIONS: Independent research teams attempting to reproduce the study based on its free-text description alone produce different implementations that vary in the population size and composition. Sharing analytical code supported by a common data model and open-source tools allows reproducing a study unambiguously thereby preserving initial design choices.
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Pesquisadores , Humanos , Bases de Dados FactuaisRESUMO
Aortic stenosis (AS) affects about 1.5 million people in the United States and is associated with a 5-year survival rate of 20% if untreated. In these patients, aortic valve replacement is performed to restore adequate hemodynamics and alleviate symptoms. The development of next-generation prosthetic aortic valves seeks to provide enhanced hemodynamic performance, durability, and long-term safety, emphasizing the need for high-fidelity testing platforms for these devices. We propose a soft robotic model that recapitulates patient-specific hemodynamics of AS and secondary ventricular remodeling which we validated against clinical data. The model leverages 3D-printed replicas of each patient's cardiac anatomy and patient-specific soft robotic sleeves to recreate the patients' hemodynamics. An aortic sleeve allows mimicry of AS lesions due to degenerative or congenital disease, whereas a left ventricular sleeve recapitulates loss of ventricular compliance and diastolic dysfunction (DD) associated with AS. Through a combination of echocardiographic and catheterization techniques, this system is shown to recreate clinical metrics of AS with greater controllability compared with methods based on image-guided aortic root reconstruction and parameters of cardiac function that rigid systems fail to mimic physiologically. Last, we leverage this model to evaluate the hemodynamic benefit of transcatheter aortic valves in a subset of patients with diverse anatomies, etiologies, and disease states. Through the development of a high-fidelity model of AS and DD, this work demonstrates the use of soft robotics to recreate cardiovascular disease, with potential applications in device development, procedural planning, and outcome prediction in industrial and clinical settings.