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1.
Proc Natl Acad Sci U S A ; 121(9): e2304643121, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38377210

RESUMO

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.


Assuntos
Adesivos , Polímeros , Humanos , Aderências Teciduais/prevenção & controle , Adesivos/química , Elastômeros , Hidrogéis/química
2.
Nature ; 587(7833): 219-224, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33177670

RESUMO

Soft machines are a promising design paradigm for human-centric devices1,2 and systems required to interact gently with their environment3,4. To enable soft machines to respond intelligently to their surroundings, compliant sensory feedback mechanisms are needed. Specifically, soft alternatives to strain gauges-with high resolution at low strain (less than 5 per cent)-could unlock promising new capabilities in soft systems. However, currently available sensing mechanisms typically possess either high strain sensitivity or high mechanical resilience, but not both. The scarcity of resilient and compliant ultra-sensitive sensing mechanisms has confined their operation to laboratory settings, inhibiting their widespread deployment. Here we present a versatile and compliant transduction mechanism for high-sensitivity strain detection with high mechanical resilience, based on strain-mediated contact in anisotropically resistive structures (SCARS). The mechanism relies upon changes in Ohmic contact between stiff, micro-structured, anisotropically conductive meanders encapsulated by stretchable films. The mechanism achieves high sensitivity, with gauge factors greater than 85,000, while being adaptable for use with high-strength conductors, thus producing sensors resilient to adverse loading conditions. The sensing mechanism also exhibits high linearity, as well as insensitivity to bending and twisting deformations-features that are important for soft device applications. To demonstrate the potential impact of our technology, we construct a sensor-integrated, lightweight, textile-based arm sleeve that can recognize gestures without encumbering the hand. We demonstrate predictive tracking and classification of discrete gestures and continuous hand motions via detection of small muscle movements in the arm. The sleeve demonstration shows the potential of the SCARS technology for the development of unobtrusive, wearable biomechanical feedback systems and human-computer interfaces.


Assuntos
Retroalimentação Sensorial , Maleabilidade , Robótica/instrumentação , Robótica/métodos , Interface Usuário-Computador , Dispositivos Eletrônicos Vestíveis , Mãos/fisiologia , Humanos , Movimento (Física) , Movimento , Têxteis
3.
Proc Natl Acad Sci U S A ; 120(32): e2304318120, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37523534

RESUMO

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.

4.
Proc Natl Acad Sci U S A ; 119(42): e2209819119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215466

RESUMO

Grasping, in both biological and engineered mechanisms, can be highly sensitive to the gripper and object morphology, as well as perception and motion planning. Here, we circumvent the need for feedback or precise planning by using an array of fluidically actuated slender hollow elastomeric filaments to actively entangle with objects that vary in geometric and topological complexity. The resulting stochastic interactions enable a unique soft and conformable grasping strategy across a range of target objects that vary in size, weight, and shape. We experimentally evaluate the grasping performance of our strategy and use a computational framework for the collective mechanics of flexible filaments in contact with complex objects to explain our findings. Overall, our study highlights how active collective entanglement of a filament array via an uncontrolled, spatially distributed scheme provides options for soft, adaptable grasping.


Assuntos
Robótica , Força da Mão , Robótica/métodos
5.
Proc Natl Acad Sci U S A ; 118(25)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34140412

RESUMO

Biological systems have a remarkable capability of synthesizing multifunctional materials that are adapted for specific physiological and ecological needs. When exploring structure-function relationships related to multifunctionality in nature, it can be a challenging task to address performance synergies, trade-offs, and the relative importance of different functions in biological materials, which, in turn, can hinder our ability to successfully develop their synthetic bioinspired counterparts. Here, we investigate such relationships between the mechanical and optical properties in a multifunctional biological material found in the highly protective yet conspicuously colored exoskeleton of the flower beetle, Torynorrhina flammea Combining experimental, computational, and theoretical approaches, we demonstrate that a micropillar-reinforced photonic multilayer in the beetle's exoskeleton simultaneously enhances mechanical robustness and optical appearance, giving rise to optical damage tolerance. Compared with plain multilayer structures, stiffer vertical micropillars increase stiffness and elastic recovery, restrain the formation of shear bands, and enhance delamination resistance. The micropillars also scatter the reflected light at larger polar angles, enhancing the first optical diffraction order, which makes the reflected color visible from a wider range of viewing angles. The synergistic effect of the improved angular reflectivity and damage localization capability contributes to the optical damage tolerance. Our systematic structural analysis of T. flammea's different color polymorphs and parametric optical and mechanical modeling further suggest that the beetle's microarchitecture is optimized toward maximizing the first-order optical diffraction rather than its mechanical stiffness. These findings shed light on material-level design strategies utilized in biological systems for achieving multifunctionality and could thus inform bioinspired material innovations.


Assuntos
Exoesqueleto/anatomia & histologia , Exoesqueleto/fisiologia , Besouros/anatomia & histologia , Besouros/fisiologia , Flores/parasitologia , Fenômenos Ópticos , Animais , Fenômenos Biomecânicos , Modelos Biológicos , Fótons , Pigmentação , Espalhamento de Radiação
6.
Heart Lung Circ ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38925996

RESUMO

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.

7.
J Struct Biol ; 215(2): 107955, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36905978

RESUMO

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.


Assuntos
Visualização de Dados , Estrelas-do-Mar , Animais , Estrelas-do-Mar/anatomia & histologia , Estrelas-do-Mar/química , Microtomografia por Raio-X , Equinodermos
8.
Prostate ; 83(7): 729-739, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36879362

RESUMO

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.


Assuntos
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 adversos
9.
BMC Med Res Methodol ; 23(1): 246, 2023 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-37865728

RESUMO

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.


Assuntos
Mães , Farmacoepidemiologia , Gravidez , Recém-Nascido , Lactente , Feminino , Humanos , Criança , Gravidez Múltipla , Algoritmos , Atenção à Saúde
10.
BMC Cardiovasc Disord ; 23(1): 33, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36653743

RESUMO

INTRODUCTION: The transradial approach for coronary artery catheterisation has increased in popularity compared to the transfemoral approach for patients undergoing percutaneous coronary interventions. However, radial artery spasm continues to be a major complication of the procedure. Current management strategies vary concerning radial artery spasm and there is limited evidence of practice in the Australian context. AIM: To identify the predictors of radial artery spasm and the medications used for its prevention and management. METHODS: A descriptive cross-sectional study was carried out over a three-month period in two tertiary hospitals in NSW, Australia. A self-administered pre-procedural survey was completed by patients undergoing coronary artery catheterisation. This survey collected socio-demographic data and assessed anxiety using the Spielberger State-Trait Anxiety Inventory. Procedural data, including length of procedure, equipment used, occurrence of radial artery spasm, and medications given, were collected post-procedure by the interventionalist. RESULTS: Of the 169 participants, over half were male (59.8%) and aged 66 years or older (56.8%). Radial artery spasm was reported in 24 (14.2%) participants. Rates of spasm were significantly higher among females (66.6%, p = 0.004), those aged under 65 years (62.5%, p = 0.001) and those who reported a medical history of anxiety (33.3%, p = 0.0004). There were no significant differences in State and Trait anxiety scores among those who had RAS and those who did not. Logistic regression identified younger age as the only statistically significant predictor of RAS (OR 0.536; 95% CI 0.171-1.684; p = 0.005). To prevent radial artery spasm most patients received midazolam (n = 158; 93.5%), nitrates (n = 133; 78.7%) and/or fentanyl (n = 124; 73.4%) prophylactically. Nitrates were the most frequently administered medication to treat radial artery spasm (78.7%). CONCLUSION: This study highlights that there is a need to develop a clearer understanding of the predictors of RAS, as identifying patients at risk can ensure prophylactic measures are implemented. This study identified nitrates as the preferred vasodilator as a preventative measure along with the use of sedation.


Assuntos
Artéria Radial , Espasmo , Feminino , Humanos , Masculino , Estudos Transversais , Artéria Radial/diagnóstico por imagem , Angiografia Coronária/efeitos adversos , Austrália , Espasmo/diagnóstico , Espasmo/etiologia , Espasmo/prevenção & controle , Cateterismo Cardíaco/efeitos adversos
11.
Nature ; 541(7637): 347-352, 2017 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-28102254

RESUMO

Advances in fabrication technologies are enabling the production of architected materials with unprecedented properties. Most such materials are characterized by a fixed geometry, but in the design of some materials it is possible to incorporate internal mechanisms capable of reconfiguring their spatial architecture, and in this way to enable tunable functionality. Inspired by the structural diversity and foldability of the prismatic geometries that can be constructed using the snapology origami technique, here we introduce a robust design strategy based on space-filling tessellations of polyhedra to create three-dimensional reconfigurable materials comprising a periodic assembly of rigid plates and elastic hinges. Guided by numerical analysis and physical prototypes, we systematically explore the mobility of the designed structures and identify a wide range of qualitatively different deformations and internal rearrangements. Given that the underlying principles are scale-independent, our strategy can be applied to the design of the next generation of reconfigurable structures and materials, ranging from metre-scale transformable architectures to nanometre-scale tunable photonic systems.

12.
Heart Lung Circ ; 32(1): 11-15, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35965245

RESUMO

The health care sector contributes to nearly 5% of global carbon emissions with the exponential growth of medical waste posing a significant challenge to environmental sustainability. As the impact of climate change on individuals and population health becomes increasingly more apparent, the health care system's significant impact on the environment is also raising concerns. Hospitals contribute disproportionately to health care waste with the majority arising from resource intensive areas such as operating theatres and cardiac catheter labs (CCLs). Despite the growing volume of cardiac procedures worldwide, initiatives to reduce waste from CCLs have received limited attention, overlooking opportunities for significant reduction in operational costs and carbon footprint. We aim to raise awareness of the current landscape of waste management in CCLs. We identify areas of resource optimisation and highlight practical strategies and frameworks employed elsewhere in health care to reduce waste. Importantly, we hope to empower health care workers in CCLs to make a meaningful change to their practice and contribute towards a more sustainable future.


Assuntos
Cateteres Cardíacos , Gerenciamento de Resíduos , Humanos , Gerenciamento de Resíduos/métodos , Pegada de Carbono
13.
Nat Mater ; 20(2): 237-241, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32958878

RESUMO

The predominantly deep-sea hexactinellid sponges are known for their ability to construct remarkably complex skeletons from amorphous hydrated silica. The skeletal system of one such species of sponge, Euplectella aspergillum, consists of a square-grid-like architecture overlaid with a double set of diagonal bracings, creating a chequerboard-like pattern of open and closed cells. Here, using a combination of finite element simulations and mechanical tests on 3D-printed specimens of different lattice geometries, we show that the sponge's diagonal reinforcement strategy achieves the highest buckling resistance for a given amount of material. Furthermore, using an evolutionary optimization algorithm, we show that our sponge-inspired lattice geometry approaches the optimum material distribution for the design space considered. Our results demonstrate that lessons learned from the study of sponge skeletal systems can be exploited for the realization of square lattice geometries that are geometrically optimized to avoid global structural buckling, with implications for improved material use in modern infrastructural applications.

14.
Nature ; 531(7592): 78-82, 2016 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-26909575

RESUMO

Controlling dropwise condensation is fundamental to water-harvesting systems, desalination, thermal power generation, air conditioning, distillation towers, and numerous other applications. For any of these, it is essential to design surfaces that enable droplets to grow rapidly and to be shed as quickly as possible. However, approaches based on microscale, nanoscale or molecular-scale textures suffer from intrinsic trade-offs that make it difficult to optimize both growth and transport at once. Here we present a conceptually different design approach--based on principles derived from Namib desert beetles, cacti, and pitcher plants--that synergistically combines these aspects of condensation and substantially outperforms other synthetic surfaces. Inspired by an unconventional interpretation of the role of the beetle's bumpy surface geometry in promoting condensation, and using theoretical modelling, we show how to maximize vapour diffusion fluxat the apex of convex millimetric bumps by optimizing the radius of curvature and cross-sectional shape. Integrating this apex geometry with a widening slope, analogous to cactus spines, directly couples facilitated droplet growth with fast directional transport, by creating a free-energy profile that drives the droplet down the slope before its growth rate can decrease. This coupling is further enhanced by a slippery, pitcher-plant-inspired nanocoating that facilitates feedback between coalescence-driven growth and capillary-driven motion on the way down. Bumps that are rationally designed to integrate these mechanisms are able to grow and transport large droplets even against gravity and overcome the effect of an unfavourable temperature gradient. We further observe an unprecedented sixfold-higher exponent of growth rate, faster onset, higher steady-state turnover rate, and a greater volume of water collected compared to other surfaces. We envision that this fundamental understanding and rational design strategy can be applied to a wide range of water-harvesting and phase-change heat-transfer applications.


Assuntos
Movimento (Física) , Transição de Fase , Água/química , Água/metabolismo , Animais , Biomimética , Cactaceae/anatomia & histologia , Cactaceae/metabolismo , Besouros/anatomia & histologia , Besouros/metabolismo , Difusão , Destilação , Gravitropismo , Plantas/anatomia & histologia , Plantas/metabolismo , Propriedades de Superfície , Temperatura , Fatores de Tempo , Volatilização , Abastecimento de Água
15.
Indoor Air ; 32(6): e13064, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35762243

RESUMO

The exhalation of aerosols during musical performances or rehearsals posed a risk of airborne virus transmission in the COVID-19 pandemic. Previous research studied aerosol plumes by only focusing on one risk factor, either the source strength or convective transport capability. Furthermore, the source strength was characterized by the aerosol concentration and ignored the airflow rate needed for risk analysis in actual musical performances. This study characterizes aerosol plumes that account for both the source strength and convective transport capability by conducting experiments with 18 human subjects. The source strength was characterized by the source aerosol emission rate, defined as the source aerosol concentration multiplied by the source airflow rate (brass 383 particle/s, singing 408 particle/s, and woodwind 480 particle/s). The convective transport capability was characterized by the plume influence distance, defined as the sum of the horizontal jet length and horizontal instrument length (brass 0.6 m, singing 0.6 m and woodwind 0.8 m). Results indicate that woodwind instruments produced the highest risk with approximately 20% higher source aerosol emission rates and 30% higher plume influence distances compared with the average of the same risk indicators for singing and brass instruments. Interestingly, the clarinet performance produced moderate source aerosol concentrations at the instrument's bell, but had the highest source aerosol emission rates due to high source airflow rates. Flute performance generated plumes with the lowest source aerosol emission rates but the highest plume influence distances due to the highest source airflow rate. Notably, these comprehensive results show that the source airflow is a critical component of the risk of airborne disease transmission. The effectiveness of masking and bell covering in reducing aerosol transmission is due to the mitigation of both source aerosol concentrations and plume influence distances. This study also found a musician who generated approximately five times more source aerosol concentrations than those of the other musicians who played the same instrument. Despite voice and brass instruments producing measurably lower average risk, it is possible to have an individual musician produce aerosol plumes with high source strength, resulting in enhanced transmission risk; however, our sample size was too small to make generalizable conclusions regarding the broad musician population.


Assuntos
Poluição do Ar em Ambientes Fechados , COVID-19 , Aerossóis e Gotículas Respiratórios , Canto , Aerossóis/análise , Poluição do Ar em Ambientes Fechados/análise , COVID-19/transmissão , Humanos , Música , Pandemias , Aerossóis e Gotículas Respiratórios/virologia
16.
Emerg Med J ; 39(11): 810-817, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34819306

RESUMO

BACKGROUND: CT performed within 6 hours of headache onset is highly sensitive for the detection of subarachnoid haemorrhage (SAH). Beyond this time frame, if the CT is negative for blood, a lumbar puncture is often performed. Technology improvements in image noise reduction, resolution and motion artefact have enhanced the performance of multislice CT (MSCT) and may have further improved sensitivity. We aimed to describe how the sensitivity to SAH of modern MSCT changes with time from headache onset. METHODS: This was a retrospective analysis of electronic data collected as part of routine care among all patients presenting to Christchurch Hospital diagnosed with a SAH between 1 January 2008 and 31 December 2017. Patients were imaged with MSCT. The primary outcome was the proportion of patients with spontaneous aneurysmal SAH (identified via coding and confirmed by clinical and radiological records) that had a positive MSCT. The secondary outcome was the proportion of patients with any type of spontaneous SAH that had a positive MSCT. RESULTS: There were 347 patients with an SAH of whom 260 were aneurysmal SAH. MSCT identified 253 (97.3%) of all aneurysmal SAH and 332 (95.7%) of all SAH. The sensitivity of MSCT was 99.6% (95% CI 97.6 to 100) for aneurysmal SAH and 99.0% (95% CI 97.1 to 99.8) for all SAH at 48 hours after headache onset. At 24 hours after headache onset, the sensitivity for aneurysmal SAH was 100% (95% CI 98.3 to 100). CONCLUSION: These data suggest that it may be possible to extend the timeframe from headache onset within which modern MSCT can be used to rule out aneurysmal SAH.


Assuntos
Hemorragia Subaracnóidea , Humanos , Hemorragia Subaracnóidea/diagnóstico por imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos , Cefaleia/etiologia , Punção Espinal/métodos
17.
JAMA ; 328(14): 1405-1414, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36219407

RESUMO

Importance: Opioids can cause severe respiratory depression by suppressing feedback mechanisms that increase ventilation in response to hypercapnia. Following the addition of boxed warnings to benzodiazepine and opioid products about increased respiratory depression risk with simultaneous use, the US Food and Drug Administration evaluated whether other drugs that might be used in place of benzodiazepines may cause similar effects. Objective: To study whether combining paroxetine or quetiapine with oxycodone, compared with oxycodone alone, decreases the ventilatory response to hypercapnia. Design, Setting, and Participants: Randomized, double-blind, crossover clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) with 25 healthy participants from January 2021 through May 25, 2021. Interventions: Oxycodone 10 mg on days 1 and 5 and the following in a randomized order for 5 days: paroxetine 40 mg daily, quetiapine twice daily (increasing daily doses from 100 mg to 400 mg), or placebo. Main Outcomes and Measures: Ventilation at end-tidal carbon dioxide of 55 mm Hg (hypercapnic ventilation) using rebreathing methodology assessed for paroxetine or quetiapine with oxycodone, compared with placebo and oxycodone, on days 1 and 5 (primary) and for paroxetine or quetiapine alone compared with placebo on day 4 (secondary). Results: Among 25 participants (median age, 35 years [IQR, 30-40 years]; 11 female [44%]), 19 (76%) completed the trial. The mean hypercapnic ventilation was significantly decreased with paroxetine plus oxycodone vs placebo plus oxycodone on day 1 (29.2 vs 34.1 L/min; mean difference [MD], -4.9 L/min [1-sided 97.5% CI, -∞ to -0.6]; P = .01) and day 5 (25.1 vs 35.3 L/min; MD, -10.2 L/min [1-sided 97.5% CI, -∞ to -6.3]; P < .001) but was not significantly decreased with quetiapine plus oxycodone vs placebo plus oxycodone on day 1 (33.0 vs 34.1 L/min; MD, -1.2 L/min [1-sided 97.5% CI, -∞ to 2.8]; P = .28) or on day 5 (34.7 vs 35.3 L/min; MD, -0.6 L/min [1-sided 97.5% CI, -∞ to 3.2]; P = .37). As a secondary outcome, mean hypercapnic ventilation was significantly decreased on day 4 with paroxetine alone vs placebo (32.4 vs 41.7 L/min; MD, -9.3 L/min [1-sided 97.5% CI, -∞ to -3.9]; P < .001), but not with quetiapine alone vs placebo (42.8 vs 41.7 L/min; MD, 1.1 L/min [1-sided 97.5% CI, -∞ to 6.4]; P = .67). No drug-related serious adverse events were reported. Conclusions and Relevance: In this preliminary study involving healthy participants, paroxetine combined with oxycodone, compared with oxycodone alone, significantly decreased the ventilatory response to hypercapnia on days 1 and 5, whereas quetiapine combined with oxycodone did not cause such an effect. Additional investigation is needed to characterize the effects after longer-term treatment and to determine the clinical relevance of these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT04310579.


Assuntos
Analgésicos Opioides , Antidepressivos , Oxicodona , Paroxetina , Fumarato de Quetiapina , Insuficiência Respiratória , Adulto , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/farmacologia , Antidepressivos/efeitos adversos , Antidepressivos/farmacologia , Benzodiazepinas/efeitos adversos , Benzodiazepinas/farmacologia , Dióxido de Carbono/análise , Método Duplo-Cego , Feminino , Humanos , Hipercapnia/etiologia , Oxicodona/efeitos adversos , Oxicodona/farmacologia , Paroxetina/efeitos adversos , Paroxetina/farmacologia , Fumarato de Quetiapina/efeitos adversos , Fumarato de Quetiapina/farmacologia , Respiração/efeitos dos fármacos , Insuficiência Respiratória/induzido quimicamente , Insuficiência Respiratória/diagnóstico
18.
Heart Lung Circ ; 31(2): 224-229, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34391688

RESUMO

BACKGROUND: Cardiac Society of Australia and New Zealand (CSANZ) guidelines recommend elective high-risk percutaneous coronary intervention (PCI) is not performed in sites greater than 1 hour from cardiac surgery. METHODS: In hospital outcomes for all patients from Orange Health Service (OHS) from January 2017 to January 2020 who were transferred electively to tertiary centres in Sydney for high risk PCI were examined. RESULTS: One hundred and fourteen (114) patients were identified, with 1,259 PCIs performed at OHS over the same period without transfer. The mean age of these 114 patients was 71 years, with 74.6% male. Receiving hospitals were Royal Prince Alfred Hospital, Sydney, NSW (66.7%), Concord Repatriation General Hospital, Concord, NSW (19.3%) and Strathfield Private Hospital, Strathfield, NSW (14%). The definition of high risk and indication for transfer included at least one of: moderate or greater calcification of the target lesion or proximal segment (34%), single or multiple target lesions that in aggregate jeopardised over 50% of remaining viable myocardium (27%), degenerated saphenous vein grafts (14.8%), chronic total occlusions (7.0%) and severe left ventricular (LV) impairment (3.9%). American Heart Society/American College of Cardiology (AHA/ACC) lesion types were A (1%), B1 (4.2%), B2 (40.2%), and C (54.6%). PCI was performed via the femoral route in 96.2%. The mean procedure duration was 72 minutes, mean combined fluoroscopy time was 19 minutes and mean radiation dose as defined by Reference Air Kerma was 1,630 mGy. Complications occurred in 13 patients and were: acute vessel dissection requiring stenting (4), perforation (2), acute vessel closure (4), puncture site related (1), and life-threatening arrhythmia (2). There were no cases of emergent coronary artery bypass graft (CABG) or death. CONCLUSION: This contemporary cohort of high-risk patients transferred electively from a regional PCI centre to a tertiary cardiac unit underwent lengthy PCI procedures, with high radiation doses, and a modest rate of peri-procedural complications, but had otherwise excellent procedural and clinical outcomes.


Assuntos
Intervenção Coronária Percutânea , Idoso , Estudos de Coortes , Ponte de Artéria Coronária , Feminino , Hospitais , Humanos , Masculino , Stents , Resultado do Tratamento , Estados Unidos
19.
Rheumatology (Oxford) ; 60(7): 3222-3234, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33367863

RESUMO

OBJECTIVES: Concern has been raised in the rheumatology community regarding recent regulatory warnings that HCQ used in the coronavirus disease 2019 pandemic could cause acute psychiatric events. We aimed to study whether there is risk of incident depression, suicidal ideation or psychosis associated with HCQ as used for RA. METHODS: We performed a new-user cohort study using claims and electronic medical records from 10 sources and 3 countries (Germany, UK and USA). RA patients ≥18 years of age and initiating HCQ were compared with those initiating SSZ (active comparator) and followed up in the short (30 days) and long term (on treatment). Study outcomes included depression, suicide/suicidal ideation and hospitalization for psychosis. Propensity score stratification and calibration using negative control outcomes were used to address confounding. Cox models were fitted to estimate database-specific calibrated hazard ratios (HRs), with estimates pooled where I2 <40%. RESULTS: A total of 918 144 and 290 383 users of HCQ and SSZ, respectively, were included. No consistent risk of psychiatric events was observed with short-term HCQ (compared with SSZ) use, with meta-analytic HRs of 0.96 (95% CI 0.79, 1.16) for depression, 0.94 (95% CI 0.49, 1.77) for suicide/suicidal ideation and 1.03 (95% CI 0.66, 1.60) for psychosis. No consistent long-term risk was seen, with meta-analytic HRs of 0.94 (95% CI 0.71, 1.26) for depression, 0.77 (95% CI 0.56, 1.07) for suicide/suicidal ideation and 0.99 (95% CI 0.72, 1.35) for psychosis. CONCLUSION: HCQ as used to treat RA does not appear to increase the risk of depression, suicide/suicidal ideation or psychosis compared with SSZ. No effects were seen in the short or long term. Use at a higher dose or for different indications needs further investigation. TRIAL REGISTRATION: Registered with EU PAS (reference no. EUPAS34497; http://www.encepp.eu/encepp/viewResource.htm? id=34498). The full study protocol and analysis source code can be found at https://github.com/ohdsi-studies/Covid19EstimationHydroxychloroquine2.


Assuntos
Antirreumáticos/efeitos adversos , Tratamento Farmacológico da COVID-19 , Depressão/induzido quimicamente , Depressão/epidemiologia , Hidroxicloroquina/efeitos adversos , Psicoses Induzidas por Substâncias/epidemiologia , Psicoses Induzidas por Substâncias/etiologia , Ideação Suicida , Suicídio/estatística & dados numéricos , Adolescente , Adulto , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Estudos de Coortes , Feminino , Alemanha , Humanos , Hidroxicloroquina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Medição de Risco , Reino Unido , Estados Unidos , Adulto Jovem
20.
Catheter Cardiovasc Interv ; 97(6): E771-E777, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33118694

RESUMO

OBJECTIVES: To assess the prognostic implications of the degree of coronary collaterals on outcomes in patients with a CTO. BACKGROUND: Coronary chronic total occlusions (CTO) are identified frequently in patients undergoing coronary angiography and have been associated with poorer prognosis. Whether the degree of coronary collaterals, the hallmark of CTOs impacts prognosis, is unknown. METHODS: A search of EMBASE, MEDLINE, and Cochrane Library was conducted to identify studies reporting on coronary collaterals and risk of all-cause mortality, acute myocardial infarction (AMI) and successful percutaneous coronary intervention (PCI). Patients with Rentrop grade 0 or 1 collaterals were defined as poor collaterals, while Rentrop grade 2 or 3 were defined as robust collaterals. RESULTS: Twelve studies with a total of 3,369 were included. Patients with robust collaterals did not have lower rates of AMI (OR: 0.89, 95%CI: 0.39-2.04) or lower rates of all-cause mortality (OR: 0.81, 95% CI: 0.42-1.58), however were more likely to have successful PCI (OR: 4.04, 95%CI: 1.10-14.85). CONCLUSION: The presence of robust collaterals is not associated with lower rates of AMI or mortality, but does increase the likelihood of successful CTO PCI. These results have importance implications with respect to the indications for CTO PCI as well as selecting appropriate patients to undergo the procedure.


Assuntos
Oclusão Coronária , Intervenção Coronária Percutânea , Doença Crônica , Circulação Colateral , Angiografia Coronária , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/terapia , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Prognóstico , Resultado do Tratamento
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