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2.
Afr J Emerg Med ; 14(2): 75-83, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38584689

RESUMO

Introduction: Standards for Emergency Medical Services [EMS] have recently been introduced in South Africa in a movement towards the promotion of quality improvement. While these standards identify a minimum set of criteria for EMS quality they do not differentiate between services just meeting them and those exceeding them. Benchmarking may be a helpful exercise in beginning to address the question of comparative levels of capability in EMS beyond a set of minimum standards. The aim of this study was to develop a consensus-based capability benchmarking tool for EMS organizations within the South African context. Methods: A total of 12 experts in the field of EMS in South Africa consented to participate in two Delphi Surveys in order to achieve consensus on the core components of an EMS organization as well as relevant level descriptors for those components. The resulting data was used to develop a consensus-based capability benchmarking tool for EMS organizations in South Africa. Results: A consensus-based capability benchmarking tool was developed that allows organizations to distinguish whether the organization's capability, as a whole, is underdeveloped, developing, or well-developed. This is in addition to identifying how capable they are in all individual components or sub-components. Conclusion: It is recommended that further research be conducted to assess this tool's implementation within different EMS organizations in South Africa, and that this study is used as a stepping-stone for additional research into meaningful quality improvement in emergency medical services in South Africa.

3.
Angew Chem Int Ed Engl ; 63(13): e202318126, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38275271

RESUMO

2-Acetonaphthones, which bear an alkenyl group tethered to its C1 carbon atom via an oxygen atom, were found to undergo an enantioselective intramolecular ortho photocycloaddition reaction. A chiral oxazaborolidine Lewis acid leads to a bathochromic absorption shift of the substrate and enables an efficient enantioface differentiation. Visible light irradiation (λ=450 nm) triggers the reaction which is tolerant of various groups at almost any position except carbon atom C8 (16 examples, 53-99 % yield, 80-97 % ee). Consecutive reactions were explored including a sensitized rearrangement to tetrahydrobiphenylenes, which occurred with full retention of configuration. Evidence was collected that the catalytic photocycloaddition occurs via triplet intermediates, and the binding mode of the acetonaphthone to the chiral Lewis acid was elucidated by DFT calculations.

4.
Ann Emerg Med ; 83(5): 435-445, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37999653

RESUMO

STUDY OBJECTIVE: Traumatic injury causes a significant number of deaths due to bleeding. Tranexamic acid (TXA), an antifibrinolytic agent, can reduce bleeding in traumatic injuries and potentially enhance outcomes. Previous reviews suggested potential TXA benefits but did not consider the latest trials. METHODS: A systematic review and bias-adjusted meta-analysis were performed to assess TXA's effectiveness in emergency traumatic injury settings by pooling estimates from randomized controlled trials. Researchers searched Medline, Embase, and Cochrane Central for randomized controlled trials comparing TXA's effects to a placebo in emergency trauma cases. The primary endpoint was 1-month mortality. The methodological quality of the trials underwent assessment using the MASTER scale, and the meta-analysis applied the quality-effects method to adjust for methodological quality. RESULTS: Seven randomized controlled trials met the set criteria. This meta-analysis indicated an 11% decrease in the death risk at 1 month after TXA use (odds ratio [OR] 0.89, 95% confidence interval [CI] 0.84 to 0.95) with a number needed to treat of 61 to avoid 1 additional death. The meta-analysis also revealed reduced 24-hour mortality (OR 0.76, 95% CI 0.65 to 0.88) for TXA. No compelling evidence of increased vascular occlusive events emerged (OR 0.96, 95% CI 0.73 to 1.27). Subgroup analyses highlighted TXA's effectiveness in general trauma versus traumatic brain injury and survival advantages when administered out-of-hospital versus inhospital. CONCLUSIONS: This synthesis demonstrates that TXA use for trauma in emergencies leads to a reduction in 1-month mortality, with no significant evidence of problematic vascular occlusive events. Administering TXA in the out-of-hospital setting is associated with reduced mortality compared to inhospital administration, and less mortality with TXA in systemic trauma is noted compared with traumatic brain injury specifically.

5.
J Chem Theory Comput ; 19(19): 6643-6655, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37775093

RESUMO

A widely used strategy to reduce the computational cost of quantum-chemical calculations is to partition the system into an active subsystem, which is the focus of the computational efforts, and an environment that is treated at a lower computational level. The system partitioning is mostly based on localized molecular orbitals. When reaction paths or energy differences are to be calculated, it is crucial to keep the orbital space consistent for all structures. Inconsistencies in orbital space can lead to unpredictable errors on the potential energy surface. While successful strategies to ensure this consistency have been established for organic and even metal-organic systems, these methods often fail for metal clusters or nanoparticles with a high density of near-degenerate and delocalized molecular orbitals. However, such systems are highly relevant for catalysis. Accurate yet feasible quantum-mechanical ab initio calculations are therefore highly desired. In this work, we present an approach based on the subsystem projected atomic orbital decomposition algorithm that allows us to ensure automated and consistent partitioning even for systems with delocalized and near-degenerate molecular orbitals and demonstrate the validity of this method for the binding energies of small molecules on transition-metal clusters.

6.
J Law Med Ethics ; 51(1): 153-171, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37226742

RESUMO

"Comprehensive Healthcare for America" is a largely single-payer reform proposal that, by applying the insights of behavioral economics, may be able to rally patients and clinicians sufficiently to overcome the opposition of politicians and vested interests to providing all Americans with less complicated and less costly access to needed healthcare.


Assuntos
Assistência Integral à Saúde , Economia Comportamental , Humanos , Dissidências e Disputas , Instalações de Saúde , Atenção à Saúde
7.
J Chem Phys ; 158(8): 084803, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36859110

RESUMO

Quantum chemical calculations on atomistic systems have evolved into a standard approach to studying molecular matter. These calculations often involve a significant amount of manual input and expertise, although most of this effort could be automated, which would alleviate the need for expertise in software and hardware accessibility. Here, we present the AutoRXN workflow, an automated workflow for exploratory high-throughput electronic structure calculations of molecular systems, in which (i) density functional theory methods are exploited to deliver minimum and transition-state structures and corresponding energies and properties, (ii) coupled cluster calculations are then launched for optimized structures to provide more accurate energy and property estimates, and (iii) multi-reference diagnostics are evaluated to back check the coupled cluster results and subject them to automated multi-configurational calculations for potential multi-configurational cases. All calculations are carried out in a cloud environment and support massive computational campaigns. Key features of all components of the AutoRXN workflow are autonomy, stability, and minimum operator interference. We highlight the AutoRXN workflow with the example of an autonomous reaction mechanism exploration of the mode of action of a homogeneous catalyst for the asymmetric reduction of ketones.

8.
J Phys Chem A ; 127(9): 2176-2193, 2023 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-36854176

RESUMO

The lack of a procedure to determine equilibrium thermodynamic properties of a small system interacting with a bath is frequently seen as a weakness of conventional statistical mechanics. A typical example for such a small system is a solute surrounded by an explicit solvation shell. One way to approach this problem is to enclose the small system of interest in a large bath of explicit solvent molecules, considerably larger than the system itself. The explicit inclusion of the solvent degrees of freedom is obviously limited by the available computational resources. A potential remedy to this problem is a microsolvation approach where only a few explicit solvent molecules are considered and surrounded by an implicit solvent bath. Still, the sampling of the solvent degrees of freedom is challenging with conventional grand canonical Monte Carlo methods, since no single chemical potential for the solvent molecules can be defined in the realm of small-system thermodynamics. In this work, a statistical thermodynamic model based on the grand canonical ensemble is proposed that avoids the conventional system size limitations and accurately characterizes the properties of the system of interest subject to the thermodynamic constraints of the bath. We extend an existing microsolvation approach to a generalized multibath "microstatistical" model and show that the previously derived approaches result as a limit of our model. The framework described here is universal and we validate our method numerically for a Lennard-Jones model fluid.

9.
Digit Discov ; 1(3): 333-343, 2022 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-35769203

RESUMO

We report a new deep learning message passing network that takes inspiration from Newton's equations of motion to learn interatomic potentials and forces. With the advantage of directional information from trainable force vectors, and physics-infused operators that are inspired by Newtonian physics, the entire model remains rotationally equivariant, and many-body interactions are inferred by more interpretable physical features. We test NewtonNet on the prediction of several reactive and non-reactive high quality ab initio data sets including single small molecules, a large set of chemically diverse molecules, and methane and hydrogen combustion reactions, achieving state-of-the-art test performance on energies and forces with far greater data and computational efficiency than other deep learning models.

10.
Int J Health Serv ; 52(3): 363-371, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35546103

RESUMO

The process of developing and marketing new pharmaceuticals in the United States is driven by a need to maximize returns to shareholders. This results all too often in the production of new medications that are expensive and of marginal value to patients and society. In line with our heightened awareness of the importance of social justice and public health-and in light of our government's alliance with private companies in bringing us COVID-19 vaccines-we need to reconsider how new pharmaceuticals are developed and distributed. Accordingly, we propose the creation of a new agency of the Food and Drug Administration (FDA) that would direct the whole process. This agency would fund the research and development of high-value medications, closely monitor the clinical studies of these new drugs, and manage their distribution at prices that are value-based, fair, and equitable.


Assuntos
Desenvolvimento de Medicamentos , Indústria Farmacêutica , United States Food and Drug Administration , Vacinas contra COVID-19 , Desenvolvimento de Medicamentos/legislação & jurisprudência , Desenvolvimento de Medicamentos/organização & administração , Humanos , Marketing , Preparações Farmacêuticas , Estados Unidos
11.
Sci Data ; 9(1): 215, 2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35581204

RESUMO

The generation of reference data for deep learning models is challenging for reactive systems, and more so for combustion reactions due to the extreme conditions that create radical species and alternative spin states during the combustion process. Here, we extend intrinsic reaction coordinate (IRC) calculations with ab initio MD simulations and normal mode displacement calculations to more extensively cover the potential energy surface for 19 reaction channels for hydrogen combustion. A total of ∼290,000 potential energies and ∼1,270,000 nuclear force vectors are evaluated with a high quality range-separated hybrid density functional, ωB97X-V, to construct the reference data set, including transition state ensembles, for the deep learning models to study hydrogen combustion reaction.

12.
Emerg Med J ; 39(6): 451-456, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34272210

RESUMO

BACKGROUND: Rapid Sequence intubation (RSI) is an airway procedure that uses sedative and paralytic drugs to facilitate endotracheal intubation. It is known that RSI could impact blood pressure in the peri-intubation period. However, little is known about blood pressure changes in longer time frames. Therefore, this analysis aims to describe the changes in systolic blood pressure in a large cohort of paramedic-led RSI cases over the whole prehospital timespan. METHODS: Intensive Care Paramedics in Victoria, Australia, are authorised to use RSI in medical or trauma patients with a Glasgow Coma Scale <10. This retrospective cohort study analysed data from patientcare records for patients aged 12 years and above that had received RSI, from 1 January 2008 to 31 December 2019. This study quantifies the systolic blood pressure changes using regression with fractional polynomial terms. The analysis is further stratified by high versus Low Shock Index (LSI). The shock index is calculated by dividing pulse rate by systolic blood pressure. RESULTS: During the study period RSI was used in 8613 patients. The median number of blood pressure measurements was 5 (IQR 3-8). Systolic blood pressure rose significantly by 3.4 mm Hg (p<0.001) and then returned to baseline in the first 5 min after intubation for LSI cases. No initial rise in blood pressure is apparent in High Shock Index (HSI) cases. Across the whole cohort, systolic blood pressure decreased by 7.1 mm Hg (95% CI 7.9 to 6.3 mm Hg; p<0.001) from the first to the last blood pressure measured. CONCLUSIONS: Our study shows that in RSI patients a small transient elevation in systolic blood pressure in the immediate postintubation period is found in LSI, but this elevation is not apparent in HSI. Blood pressure decreased over the prehospital phase in RSI patients with LSI, but increased for HSI cases.


Assuntos
Serviços Médicos de Emergência , Indução e Intubação de Sequência Rápida , Pressão Sanguínea , Humanos , Intubação Intratraqueal/efeitos adversos , Estudos Retrospectivos , Vitória
13.
Simul Healthc ; 17(2): 96-103, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-34608105

RESUMO

INTRODUCTION: Anxiety experienced by students participating in simulations may impede their learning and performance. The added anxiety brought about by the socioevaluative nature of simulation assessments may accentuate this effect. This study aimed to assess the relationship between anxiety experienced by emergency care students and performance in an authentic prehospital emergency care simulation assessment. METHODS: The State-Trait Anxiety Inventory (STAI) was completed before and after a simulation assessment by 58 emergency care students across all academic years of study of a 4-year degree program in prehospital emergency care. The state anxiety component of the STAI was plotted together with marks obtained by each student using a standardized assessment tool, and curve estimation was used to determine the nature of the relationship between state anxiety scores and marks. RESULTS: Mean preassessment STAI scores were lower than mean postassessment scores (48.74 vs. 57.74), but mean scores from both groups were greater than normal mean scores for college students. The relationship of both preassessment and postassessment STAI scores with assessment marks was best described by a quadratic curve suggesting that performance was better at both the lower and higher ends of the range of STAI scores compared with the middle. Postassessment STAI scores provided a better fit with simulation assessment marks. CONCLUSIONS: This study did not confirm the expected decrease in performance associated with increasing anxiety but rather suggests that some students may have the ability to respond positively to the highest levels of anxiety during simulation assessments.


Assuntos
Ansiedade , Serviços Médicos de Emergência , Ansiedade/terapia , Humanos , Estudantes
14.
Chemistry ; 28(7): e202103130, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34773654

RESUMO

High-valent tetraalkylcuprates(iii) and -argentates(iii) are key intermediates of copper- and silver-mediated C-C coupling reactions. Here, we investigate the previously reported contrasting reactivity of [RMiii Me3 ]- complexes (M=Cu, Ag and R=allyl) with energy-dependent collision-induced dissociation experiments, advanced quantum-chemical calculations and kinetic computations. The gas-phase fragmentation experiments confirmed the preferred formation of the [RCuMe]- anion upon collisional activation of the cuprate(iii) species, consistent with a homo-coupling reaction, whereas the silver analogue primarily yielded [AgMe2 ]- , consistent with a cross-coupling reaction. For both complexes, density functional theory calculations identified one mechanism for homo coupling and four different ones for cross coupling. Of these pathways, an unprecedented concerted outer-sphere cross coupling is of particular interest, because it can explain the formation of [AgMe2 ]- from the argentate(iii) species. Remarkably, the different C-C coupling propensities of the two [RMiii Me3 ]- complexes become only apparent when properly accounting for the multi-configurational character of the wave function for the key transition state of [RAgMe3 ]- . Backed by the obtained detailed mechanistic insight for the gas-phase reactions, we propose that the previously observed cross-coupling reaction of the silver complex in solution proceeds via the outer-sphere mechanism.

15.
Proc Natl Acad Sci U S A ; 118(47)2021 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-34782461

RESUMO

The double layer at the solid/electrolyte interface is a key concept in electrochemistry. Here, we present an experimental study combined with simulations, which provides a molecular picture of the double-layer formation under applied voltage. By THz spectroscopy we are able to follow the stripping away of the cation/anion hydration shells for an NaCl electrolyte at the Au surface when decreasing/increasing the bias potential. While Na+ is attracted toward the electrode at the smallest applied negative potentials, stripping of the Cl- hydration shell is observed only at higher potential values. These phenomena are directly measured by THz spectroscopy with ultrabright synchrotron light as a source and rationalized by accompanying molecular dynamics simulations and electronic-structure calculations.

16.
Health SA ; 26: 1558, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34394964

RESUMO

BACKGROUND: The phenomenon of managing paediatric emergencies in the pre-hospital environment within the South African setting is poorly understood with specific regard to what emergency care personnel are experiencing when managing paediatric emergencies. AIM: The aim of this study was to explore and describe the lived experiences of emergency care personnel in managing paediatric patients in the pre-hospital environment and to understand the meaning and the significance of these experiences. SETTING: All participants were purposively sampled from emergency medical services agencies operating within the Johannesburg metropolitan city area. METHODS: This study followed a qualitative, exploratory, descriptive, phenomenological design, whereby participants purposively sampled within the Johannesburg metropolitan city voluntarily consented to one-on-one interviews (n = 10). RESULTS: Three main themes, with 11 contributing categories, were identified and contextualised with available literature. Emerging from the main themes was an overall sense that managing paediatric emergencies is a negative experience, coloured with feelings of inadequacy, stress, anxiety and even fear. CONCLUSIONS: The findings of this study provided new insights into what South African EMS are experiencing when managing paediatric emergencies, which enables future research efforts to identify research and practice gaps that are relevant to paediatric pre-hospital emergency care, and that are specific to the South African environment. CONTRIBUTION: This research provides preliminary insight into the lived experiences of prehospital personnel managing paediatric emergencies as well as emerging recommendations for the improvement of the prehospital care of paediatric patients.

17.
Afr J Emerg Med ; 11(2): 218-222, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33680745

RESUMO

BACKGROUND: Endotracheal intubation by direct laryngoscopy is a mainstay of advanced airway management performed both in the prehospital environment and in the Emergency Department. Many factors may affect the quality of view during direct laryngoscopy, one of them being the visual acuity (VA) of the intubator under these demanding conditions. While some individual variation in VA is to be expected in younger populations, VA naturally deteriorates in older populations particularly beyond the age of 40 years. This study aimed to describe VA in a younger (n=19) and an older (≥40 years of age, n=20) cohort of intubators at baseline and during simulated adult laryngoscopy, and to compare VA between these two age cohorts. METHODS: A baseline near VA test was done using a Sloan Early Treatment Diabetic Retinopathy Study (EDTRS) near vision chart at 40 cm under ambient indoor light. Participants in both age cohorts were then requested to perform laryngoscopy using an airway simulator at 40 cm viewing distance and again at a viewing distance of their choice. Both binocular and monocular VA were tested using a near VA chart placed anterior to the vocal cords of the airway trainer. VA was quantified using the logarithm of the minimum angle of resolution (logMAR). Differences in VA between age cohorts were assessed using independent samples t-tests and differences within age cohorts were assessed using paired samples t-tests. RESULTS: Binocular and monocular near VA was significantly reduced in the older cohort compared to the younger cohort at baseline (both eyes -0.129 logMAR; p = 0.04, right eye -0.147 logMAR; p = 0.005, left eye -0.197 logMAR; p = 0.002). Within each age cohort VA was significantly reduced during laryngoscopy at a fixed viewing distance (younger; both eyes -0.111 logMAR; p < 0.001, right eye -0.095 logMAR; p < 0.001, left eye -0.105 logMAR; p < 0.001; older; both eyes -0,08 logMAR; p < 0.001, right eye -0.110 logMAR; p < 0.001, left eye -0.065 logMAR; p = 0.01) but this was improved by reducing viewing distance. CONCLUSION: Increased age was associated with a significant reduction in VA at baseline and during laryngoscopy, which can be partially compensated for by adjusting viewing distance. Although it is currently unknown to what extent this age-related reduction of VA might negatively affect time to place an endotracheal tube or success of placement under direct vision, older intubators should be aware of this effect and consider specialized corrective eyewear in order to maintain an adequate level of VA.

18.
J Chem Phys ; 152(21): 214117, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32505150

RESUMO

MOLCAS/OpenMolcas is an ab initio electronic structure program providing a large set of computational methods from Hartree-Fock and density functional theory to various implementations of multiconfigurational theory. This article provides a comprehensive overview of the main features of the code, specifically reviewing the use of the code in previously reported chemical applications as well as more recent applications including the calculation of magnetic properties from optimized density matrix renormalization group wave functions.

19.
Afr J Emerg Med ; 10(1): 35-39, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32161710

RESUMO

BACKGROUND: Clinical simulation has become widespread as a training and assessment tool across a range of health professions, including emergency care. As with any form of assessment, simulations may be associated with stress and anxiety ("distress") which may have a negative effect on student performance if demands required by the simulation outweigh the available resources. This study aimed to assess the effect of participation by students in an emergency care simulation on an objective measure of stress and a subjective measure of anxiety. METHODS: Heart rate variability (HRV) and scores from a validated state anxiety instrument (the State-Trait Anxiety Inventory) were assessed in 36 emergency medical care students participating in scheduled simulation assessments. Data recorded during a resting control period were used for comparison. RESULTS: HRV variables showed changes in the simulation assessment group suggesting decreased variability and parasympathetic withdrawal, however these were not significantly different to control. Heart rate in the simulation assessment group increased significantly (73.5/min vs. 107.3/min, p < 0.001). State anxiety scores increased significantly both before (33.5 vs. 49.1, p < 0.001) and after (33.5 vs. 60, p < 0.001) the simulation assessment, compared to control. No linear relationship was found between any HRV variables and anxiety scores. CONCLUSION: Participating in an emergency care simulation assessment significantly elevated levels of anxiety in a group of 36 students, however an objective measure of stress did not identify changes significantly different to those at rest, with the exception of heart rate. The high levels of anxiety documented before and after simulation assessments may have a negative effect on performance and require further investigation.

20.
J Phys Chem A ; 124(14): 2834-2841, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32186877

RESUMO

Multiconfigurational wave functions are known to describe the electronic structure across a Born-Oppenheimer surface qualitatively correct. However, for quantitative reaction energies, dynamic correlation originating from the many configurations involving excitations out of the restricted orbital space, the active space, must be considered. Standard procedures involve approximations that eventually limit the ultimate accuracy achievable (most prominently, multireference perturbation theory). At the same time, the computational cost increases dramatically due to the necessity to obtain higher-order reduced density matrices. It is this disproportion that leads us here to propose an MC-srDFT-D hybrid approach of semiclassical dispersion (D) corrections to cover long-range dynamic correlation in a multiconfigurational (MC) wave function theory, which includes short-range (sr) dynamic correlation by density functional theory (DFT) without double counting. We demonstrate that the reliability of this approach is very good (at negligible cost), especially when considering that standard second-order multireference perturbation theory usually overestimates dispersion interactions.

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