Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 577(7791): 502-508, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31816625

RESUMO

In conventional intercalation cathodes, alkali metal ions can move in and out of a layered material with the charge being compensated for by reversible reduction and oxidation of the transition metal ions. If the cathode material used in a lithium-ion or sodium-ion battery is alkali-rich, this can increase the battery's energy density by storing charge on the oxide and the transition metal ions, rather than on the transition metal alone1-10. There is a high voltage associated with oxidation of O2- during the first charge, but this is not recovered on discharge, resulting in reduced energy density11. Displacement of transition metal ions into the alkali metal layers has been proposed to explain the first-cycle voltage loss (hysteresis)9,12-16. By comparing two closely related intercalation cathodes, Na0.75[Li0.25Mn0.75]O2 and Na0.6[Li0.2Mn0.8]O2, here we show that the first-cycle voltage hysteresis is determined by the superstructure in the cathode, specifically the local ordering of lithium and transition metal ions in the transition metal layers. The honeycomb superstructure of Na0.75[Li0.25Mn0.75]O2, present in almost all oxygen-redox compounds, is lost on charging, driven in part by formation of molecular O2 inside the solid. The O2 molecules are cleaved on discharge, reforming O2-, but the manganese ions have migrated within the plane, changing the coordination around O2- and lowering the voltage on discharge. The ribbon superstructure in Na0.6[Li0.2Mn0.8]O2 inhibits manganese disorder and hence O2 formation, suppressing hysteresis and promoting stable electron holes on O2- that are revealed by X-ray absorption spectroscopy. The results show that voltage hysteresis can be avoided in oxygen-redox cathodes by forming materials with a ribbon superstructure in the transition metal layers that suppresses migration of the transition metal.

2.
Nature ; 583(7818): 785-789, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32690938

RESUMO

An exciton is the bosonic quasiparticle of electron-hole pairs bound by the Coulomb interaction1. Bose-Einstein condensation of this exciton state has long been the subject of speculation in various model systems2,3, and examples have been found more recently in optical lattices and two-dimensional materials4-9. Unlike these conventional excitons formed from extended Bloch states4-9, excitonic bound states from intrinsically many-body localized states are rare. Here we show that a spin-orbit-entangled exciton state appears below the Néel temperature of 150 kelvin in NiPS3, an antiferromagnetic van der Waals material. It arises intrinsically from the archetypal many-body states of the Zhang-Rice singlet10,11, and reaches a coherent state assisted by the antiferromagnetic order. Using configuration-interaction theory, we determine the origin of the coherent excitonic excitation to be a transition from a Zhang-Rice triplet to a Zhang-Rice singlet. We combine three spectroscopic tools-resonant inelastic X-ray scattering, photoluminescence and optical absorption-to characterize the exciton and to demonstrate an extremely narrow excitonic linewidth below 50 kelvin. The discovery of the spin-orbit-entangled exciton in antiferromagnetic NiPS3 introduces van der Waals magnets as a platform to study coherent many-body excitons.

3.
J Synchrotron Radiat ; 31(Pt 3): 578-589, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38530831

RESUMO

The beamline optics and endstations at branch B of the Versatile Soft X-ray (VerSoX) beamline B07 at Diamond Light Source are described. B07-B provides medium-flux X-rays in the range 45-2200 eV from a bending magnet source, giving access to local electronic structure for atoms of all elements from Li to Y. It has an endstation for high-throughput X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine-structure (NEXAFS) measurements under ultrahigh-vacuum (UHV) conditions. B07-B has a second endstation dedicated to NEXAFS at pressures from UHV to ambient pressure (1 atm). The combination of these endstations permits studies of a wide range of interfaces and materials. The beamline and endstation designs are discussed in detail, as well as their performance and the commissioning process.

4.
Phys Rev Lett ; 132(6): 066004, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38394564

RESUMO

We have investigated the 3d orbital excitations in CaCuO_{2} (CCO), Nd_{2}CuO_{4} (NCO), and La_{2}CuO_{4} (LCO) using high-resolution resonant inelastic x-ray scattering. In LCO they behave as well-localized excitations, similarly to several other cuprates. On the contrary, in CCO and NCO the d_{xy} orbital clearly disperses, pointing to a collective character of this excitation (orbiton) in compounds without apical oxygen. We ascribe the origin of the dispersion as stemming from a substantial next-nearest-neighbor (NNN) orbital superexchange. Such an exchange leads to the liberation of the orbiton from its coupling to magnons, which is associated with the orbiton hopping between nearest neighbor copper sites. Finally, we show that the exceptionally large NNN orbital superexchange can be traced back to the absence of apical oxygens suppressing the charge transfer energy.

5.
Dysphagia ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839625

RESUMO

Although the psychosocial sequelae of living with dysphagia secondary to Parkinson disease (PD) are described in the literature as challenging, there has been little focus on using this information to influence the design of dysphagia treatment. A more nuanced understanding of the psychosocial experiences of this population may assist clinicians in providing a patient-centered approach to care. Our study was designed to gather insight into the common psychosocial experiences associated with dysphagia in the context of PD. A semi-structured interview consisting of open- and closed items was conducted with 25 individuals from regions across the country with self-reported oropharyngeal dysphagia secondary to PD. Questions were developed using comprehensive stress and coping frameworks that emphasized psychosocial predictors of specific affective reactions (e.g., grief, anxiety, depression), including self-evaluation (e.g., self-identity), coping strategies, social support, personal expectations (including perceived control over symptoms and prognosis), positive experiences, and perceptions of personal growth. Interview responses were subjected to a qualitative analysis and revealed three dominant themes: (1) Recalibration of a PD Diagnosis, (2) Vigilant Caution to Swallowing, and (3) Grieving the Loss of the Communal Meal. Using these data interpretations, we discuss three concepts for speech-language pathologists working with individuals with dysphagia and PD to consider during clinical interactions; these are reframing swallowing vigilance to engagement with mindful eating, using biofeedback to align patient perceptions and swallow physiology, and understanding the consequences of loss (of their former swallowing ability) through grief and growth reactions.

6.
Dysphagia ; 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38839626

RESUMO

Dysphagia is a leading cause of morbidity and mortality among individuals with Parkinson's disease (PD). The primary objectives of the present study were to explore patients' narrative reports focused on what information and evaluation and treatment experiences they identified as they manage dysphagia, and to identify practice patterns relevant to dysphagia management. A secondary objective was to produce an educational resource for this population that addressed their questions about dysphagia. A sample of individuals with oropharyngeal dysphagia secondary to PD (n = 25) across all regions of the United States were interviewed using open- and closed questions and a written questionnaire. Verbatim interview transcripts were interrogated using qualitative content analysis (QCA) with an inductive approach to identify themes from the participants' reported knowledge of dysphagia and experiences with swallowing evaluation and treatment. Authors developed a pamphlet addressing common questions that participants posed in the interviews and conducted a member check to revise it with their feedback. Most participants reported having been asked about their swallowing function by a healthcare professional. 60% of the sample reported having had a swallowing evaluation. Only 20% (5/25) of participants reported having completed swallowing therapy. Some participants did not know that swallowing therapy exists. Nearly all participants reported having a strong desire to know more about dysphagia and preferred a pamphlet as a resource format. Few of the study participants had received swallowing therapy, and nearly all participants were eager to learn about the nature of dysphagia, its progression, and treatment options. Given the physical, emotional, and social ramifications of living with dysphagia, access to swallowing education and treatment needs to be a stronger focus of PD management.

7.
Medicina (Kaunas) ; 60(2)2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38399591

RESUMO

Background and Objectives: We analyzed delirium testing, delirium prevalence, critical care associations outcomes at the time of hospital discharge in patients with acute brain injury (ABI) due to acute ischemic stroke (AIS), non-traumatic subarachnoid hemorrhage (SAH), non-traumatic intraparenchymal hemorrhage (IPH), and traumatic brain injury (TBI) admitted to an intensive care unit. Materials and Methods: We examined the frequency of assessment for delirium using the Confusion Assessment Method for the intensive care unit. We assessed delirium testing frequency, associated factors, positive test outcomes, and their correlations with clinical care, including nonpharmacological interventions and pain, agitation, and distress management. Results: Amongst 11,322 patients with ABI, delirium was tested in 8220 (726%). Compared to patients 18-44 years of age, patients 65-79 years (aOR 0.79 [0.69, 0.90]), and those 80 years and older (aOR 0.58 [0.50, 0.68]) were less likely to undergo delirium testing. Compared to English-speaking patients, non-English-speaking patients (aOR 0.73 [0.64, 0.84]) were less likely to undergo delirium testing. Amongst 8220, 2217 (27.2%) tested positive for delirium. For every day in the ICU, the odds of testing positive for delirium increased by 1.11 [0.10, 0.12]. Delirium was highest in those 80 years and older (aOR 3.18 [2.59, 3.90]). Delirium was associated with critical care resource utilization and with significant odds of mortality (aOR 7.26 [6.07, 8.70] at the time of hospital discharge. Conclusions: In conclusion, we find that seven out of ten patients in the neurocritical care unit are tested for delirium, and approximately two out of every five patients test positive for delirium. We demonstrate disparities in delirium testing by age and preferred language, identified high-risk subgroups, and the association between delirium, critical care resource use, complications, discharge GCS, and disposition. Prioritizing equitable testing and diagnosis, especially for elderly and non-English-speaking patients, is crucial for delivering quality care to this vulnerable group.


Assuntos
Lesões Encefálicas , Delírio , AVC Isquêmico , Humanos , Idoso , Delírio/diagnóstico , Delírio/epidemiologia , Delírio/etiologia , Alta do Paciente , AVC Isquêmico/complicações , Cuidados Críticos , Unidades de Terapia Intensiva , Lesões Encefálicas/complicações , Hospitais
8.
BMC Anesthesiol ; 23(1): 296, 2023 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-37667258

RESUMO

BACKGROUND: Electronic health records (EHR) contain large volumes of unstructured free-form text notes that richly describe a patient's health and medical comorbidities. It is unclear if perioperative risk stratification can be performed directly from these notes without manual data extraction. We conduct a feasibility study using natural language processing (NLP) to predict the American Society of Anesthesiologists Physical Status Classification (ASA-PS) as a surrogate measure for perioperative risk. We explore prediction performance using four different model types and compare the use of different note sections versus the whole note. We use Shapley values to explain model predictions and analyze disagreement between model and human anesthesiologist predictions. METHODS: Single-center retrospective cohort analysis of EHR notes from patients undergoing procedures with anesthesia care spanning all procedural specialties during a 5 year period who were not assigned ASA VI and also had a preoperative evaluation note filed within 90 days prior to the procedure. NLP models were trained for each combination of 4 models and 8 text snippets from notes. Model performance was compared using area under the receiver operating characteristic curve (AUROC) and area under the precision recall curve (AUPRC). Shapley values were used to explain model predictions. Error analysis and model explanation using Shapley values was conducted for the best performing model. RESULTS: Final dataset includes 38,566 patients undergoing 61,503 procedures with anesthesia care. Prevalence of ASA-PS was 8.81% for ASA I, 31.4% for ASA II, 43.25% for ASA III, and 16.54% for ASA IV-V. The best performing models were the BioClinicalBERT model on the truncated note task (macro-average AUROC 0.845) and the fastText model on the full note task (macro-average AUROC 0.865). Shapley values reveal human-interpretable model predictions. Error analysis reveals that some original ASA-PS assignments may be incorrect and the model is making a reasonable prediction in these cases. CONCLUSIONS: Text classification models can accurately predict a patient's illness severity using only free-form text descriptions of patients without any manual data extraction. They can be an additional patient safety tool in the perioperative setting and reduce manual chart review for medical billing. Shapley feature attributions produce explanations that logically support model predictions and are understandable to clinicians.


Assuntos
Anestesia , Anestesiologistas , Humanos , Processamento de Linguagem Natural , Estudos Retrospectivos , Estados Unidos
9.
Proc Natl Acad Sci U S A ; 117(28): 16219-16225, 2020 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-32586955

RESUMO

Charge-density waves (CDWs) are ubiquitous in underdoped cuprate superconductors. As a modulation of the valence electron density, CDWs in hole-doped cuprates possess both Cu-3d and O-2p orbital character owing to the strong hybridization of these orbitals near the Fermi level. Here, we investigate underdoped Bi2Sr1.4La0.6CuO6+δ using resonant inelastic X-ray scattering (RIXS) and find that a short-range CDW exists at both Cu and O sublattices in the copper-oxide (CuO2) planes with a comparable periodicity and correlation length. Furthermore, we uncover bond-stretching and bond-buckling phonon anomalies concomitant to the CDWs. Comparing to slightly overdoped Bi2Sr1.8La0.2CuO6+δ, where neither CDWs nor phonon anomalies appear, we highlight that a sharp intensity anomaly is induced in the proximity of the CDW wavevector (QCDW) for the bond-buckling phonon, in concert with the diffused intensity enhancement of the bond-stretching phonon at wavevectors much greater than QCDW Our results provide a comprehensive picture of the quasistatic CDWs, their dispersive excitations, and associated electron-phonon anomalies, which are key for understanding the competing electronic instabilities in cuprates.

10.
Curr Opin Anaesthesiol ; 36(2): 132-136, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36421076

RESUMO

PURPOSE OF REVIEW: The global coronavirus disease 2019 (COVID-19) viral outbreak and the rise of the anti-Black racism movement have produced a dual pandemic over the past few years, which has been associated with a dramatic rise in gun violence across the United States. This comprehensive review was performed to examine the current levels of gun violence in the context of these dual pandemics, delineate factors which have synergistically produced this surge in interpersonal violence, and propose future directions. RECENT FINDINGS: Dual pandemics have mutually contributed to a worsening in many social determinants of health and thereby have had a particularly dramatic impact on many of our most vulnerable patients, including patients of minority races and ethnicities, in terms of interpersonal violence. Firearm injuries are at their highest rate in decades. The challenges in the trauma care of these patients have been compounded by staffing and resource shortages related to the COVID-19 pandemic and attrition of medical workers related to burnout. SUMMARY: Consequences of the COVID-19 pandemic and the anti-Black racism movement have produced a social environment in the United States in recent years where interpersonal violence, especially firearm injuries, have surged. Particularly, during a time of challenged patient care delivery, the medical system struggles to support the increase in trauma volume. A broad approach to improving social determinants of health should be pursued in order to decrease the risk of gun violence from the recent near-historical high levels.


Assuntos
COVID-19 , Armas de Fogo , Violência com Arma de Fogo , Ferimentos por Arma de Fogo , Humanos , Estados Unidos , Ferimentos por Arma de Fogo/epidemiologia , Pandemias , Violência , SARS-CoV-2
11.
J Synchrotron Radiat ; 29(Pt 2): 563-580, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-35254322

RESUMO

The I21 beamline at Diamond Light Source is dedicated to advanced resonant inelastic X-ray scattering (RIXS) for probing charge, orbital, spin and lattice excitations in materials across condensed matter physics, applied sciences and chemistry. Both the beamline and the RIXS spectrometer employ divergent variable-line-spacing gratings covering a broad energy range of 280-3000 eV. A combined energy resolution of ∼35 meV (16 meV) is readily achieved at 930 eV (530 eV) owing to the optimized optics and the mechanics. Considerable efforts have been paid to the design of the entire beamline, particularly the implementation of the collection mirrors, to maximize the X-ray photon throughput. The continuous rotation of the spectrometer over 150° under ultra high vacuum and a cryogenic manipulator with six degrees of freedom allow accurate mappings of low-energy excitations from solid state materials in momentum space. Most importantly, the facility features a unique combination of the high energy resolution and the high photon throughput vital for advanced RIXS applications. Together with its stability and user friendliness, I21 has become one of the most sought after RIXS beamlines in the world.

12.
JAMA ; 328(3): 270-279, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35707974

RESUMO

Importance: Hypotension is common during tracheal intubation of critically ill adults and increases the risk of cardiac arrest and death. Whether administering an intravenous fluid bolus to critically ill adults undergoing tracheal intubation prevents severe hypotension, cardiac arrest, or death remains uncertain. Objective: To determine the effect of fluid bolus administration on the incidence of severe hypotension, cardiac arrest, and death. Design, Setting, and Participants: This randomized clinical trial enrolled 1067 critically ill adults undergoing tracheal intubation with sedation and positive pressure ventilation at 11 intensive care units in the US between February 1, 2019, and May 24, 2021. The date of final follow-up was June 21, 2021. Interventions: Patients were randomly assigned to receive either a 500-mL intravenous fluid bolus (n = 538) or no fluid bolus (n = 527). Main Outcomes and Measures: The primary outcome was cardiovascular collapse (defined as new or increased receipt of vasopressors or a systolic blood pressure <65 mm Hg between induction of anesthesia and 2 minutes after tracheal intubation, or cardiac arrest or death between induction of anesthesia and 1 hour after tracheal intubation). The secondary outcome was the incidence of death prior to day 28, which was censored at hospital discharge. Results: Among 1067 patients randomized, 1065 (99.8%) completed the trial and were included in the primary analysis (median age, 62 years [IQR, 51-70 years]; 42.1% were women). Cardiovascular collapse occurred in 113 patients (21.0%) in the fluid bolus group and in 96 patients (18.2%) in the no fluid bolus group (absolute difference, 2.8% [95% CI, -2.2% to 7.7%]; P = .25). New or increased receipt of vasopressors occurred in 20.6% of patients in the fluid bolus group compared with 17.6% of patients in the no fluid bolus group, a systolic blood pressure of less than 65 mm Hg occurred in 3.9% vs 4.2%, respectively, cardiac arrest occurred in 1.7% vs 1.5%, and death occurred in 0.7% vs 0.6%. Death prior to day 28 (censored at hospital discharge) occurred in 218 patients (40.5%) in the fluid bolus group compared with 223 patients (42.3%) in the no fluid bolus group (absolute difference, -1.8% [95% CI, -7.9% to 4.3%]; P = .55). Conclusions and Relevance: Among critically ill adults undergoing tracheal intubation, administration of an intravenous fluid bolus compared with no fluid bolus did not significantly decrease the incidence of cardiovascular collapse. Trial Registration: ClinicalTrials.gov Identifier: NCT03787732.


Assuntos
Estado Terminal , Hidratação , Parada Cardíaca , Hipotensão , Intubação Intratraqueal , Choque , Adulto , Idoso , Estado Terminal/terapia , Feminino , Parada Cardíaca/etiologia , Parada Cardíaca/mortalidade , Parada Cardíaca/terapia , Humanos , Hipnóticos e Sedativos/uso terapêutico , Hipotensão/tratamento farmacológico , Hipotensão/etiologia , Hipotensão/prevenção & controle , Intubação Intratraqueal/efeitos adversos , Masculino , Pessoa de Meia-Idade , Respiração com Pressão Positiva , Choque/etiologia , Choque/terapia , Vasoconstritores/uso terapêutico
13.
Medicina (Kaunas) ; 59(1)2022 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-36676652

RESUMO

Background and objective: There is no report of the rate of opioid prescription at the time of hospital discharge, which may be associated with various patient and procedure-related factors. This study examined the prevalence and factors associated with prescribing opioids for head/neck pain after elective craniotomy for tumor resection/vascular repair. Methods: We performed a retrospective cohort study on adults undergoing elective craniotomy for tumor resection/vascular repair at a large quaternary-care hospital. We used univariable and multivariable analysis to examine the prevalence and factors (pre-operative, intraoperative, and postoperative) associated with prescribing opioids at the time of hospital discharge. We also examined the factors associated with discharge oral morphine equivalent use. Results: The study sample comprised 273 patients with a median age of 54 years [IQR 41,65], 173 females (63%), 174 (63.7%) tumor resections, and 99 (36.2%) vascular repairs. The majority (n = 264, 96.7%) received opioids postoperatively. The opiate prescription rates were 72% (n = 196/273) at hospital discharge, 23% (19/83) at neurosurgical clinical visits within 30 days of the procedure, and 2.4% (2/83) after 30 days from the procedure. The median oral morphine equivalent (OME) at discharge use was 300 [IQR 175,600]. Patients were discharged with a median supply of 5 days [IQR 3,7]. On multivariable analysis, opioid prescription at hospital discharge was associated with pre-existent chronic pain (adjusted odds ratio, aOR 1.87 [1.06,3.29], p = 0.03) and time from surgery to hospital discharge (compared to patients discharged within days 1−4 postoperatively, patients discharged between days 5−12 (aOR 0.3, 95% CI [0.15; 0.59], p = 0.0005), discharged at 12 days and later (aOR 0.17, 95% CI [0.07; 0.39], p < 0.001)). There was a linear relationship between the first 24 h OME (p < 0.001), daily OME (p < 0.001), hospital OME (p < 0.001), and discharge OME. Conclusions: This single-center study finds that at the time of hospital discharge, opioids are prescribed for head/neck pain in as many as seven out of ten patients after elective craniotomy. A history of chronic pain and time from surgery to discharge may be associated with opiate prescriptions. Discharge OME may be associated with first 24-h, daily OME, and hospital OME use. Findings need further evaluation in a large multicenter sample. The findings are important to consider as there is growing interest in an early discharge after elective craniotomy.


Assuntos
Dor Crônica , Neoplasias , Alcaloides Opiáceos , Adulto , Feminino , Humanos , Analgésicos Opioides/uso terapêutico , Cervicalgia/tratamento farmacológico , Estudos Retrospectivos , Dor Crônica/tratamento farmacológico , Prevalência , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/epidemiologia , Morfina/uso terapêutico , Alta do Paciente , Cefaleia , Prescrições de Medicamentos , Alcaloides Opiáceos/uso terapêutico , Neoplasias/tratamento farmacológico
14.
Phys Rev Lett ; 127(9): 097203, 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34506205

RESUMO

Since the discovery of charge disproportionation in the FeO_{2} square-lattice compound Sr_{3}Fe_{2}O_{7} by Mössbauer spectroscopy more than fifty years ago, the spatial ordering pattern of the disproportionated charges has remained "hidden" to conventional diffraction probes, despite numerous x-ray and neutron scattering studies. We have used neutron Larmor diffraction and Fe K-edge resonant x-ray scattering to demonstrate checkerboard charge order in the FeO_{2} planes that vanishes at a sharp second-order phase transition upon heating above 332 K. Stacking disorder of the checkerboard pattern due to frustrated interlayer interactions broadens the corresponding superstructure reflections and greatly reduces their amplitude, thus explaining the difficulty of detecting them by conventional probes. We discuss the implications of these findings for research on "hidden order" in other materials.

15.
Neurocrit Care ; 33(2): 499-507, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-31974871

RESUMO

BACKGROUND: The prevalence, characteristics, and outcomes related to the ventilator-associated event(s) (VAE) in neurocritically ill patients are unknown and examined in this study. METHODS: A retrospective study was performed on neurocritically ill patients at a 413-bed level 1 trauma and stroke center who received three or more days of mechanical ventilation to describe rates of VAE, describe characteristics of patients with VAE, and examine the association of VAE on ventilator days, mortality, length of stay, and discharge to home. RESULTS: Over a 5-year period from 2014 through 2018, 855 neurocritically ill patients requiring mechanical ventilation were identified. A total of 147 VAEs occurred in 130 (15.2%) patients with an overall VAE rate of 13 per 1000 ventilator days and occurred across age, sex, BMI, and admission Glasgow Coma Scores. The average time from the start of ventilation to a VAE was 5 (range 3-48) days after initiation of mechanical ventilation. Using Centers for Disease Control and Prevention definitions, VAEs met criteria for a ventilator-associated condition in 58% of events (n = 85), infection-related VAE in 22% of events (n = 33), and possible ventilator-associated pneumonia in 20% of events (n = 29). A most common trigger for VAE was an increase in positive end-expiratory pressure (84%). Presence of a VAE was associated with an increase in duration of mechanical ventilation (17.4[IQR 20.5] vs. 7.9[8.9] days, p < 0.001, 95% CI 7.86-13.92), intensive care unit (ICU) length of stay (20.2[1.1] vs. 12.5[0.4] days, p < 0.001 95% CI 5.3-10.02), but not associated with in-patient mortality (34.1 vs. 31.3%. 95% CI 0.76-1.69) or discharge to home (12.7% vs. 16.3%, 95% 0.47-1.29). CONCLUSIONS: VAE are prevalent in the neurocritically ill. They result in an increased duration of mechanical ventilation and ICU length of stay, but may not be associated with in-hospital mortality or discharge to home.


Assuntos
Pneumonia Associada à Ventilação Mecânica , Ventiladores Mecânicos , Humanos , Unidades de Terapia Intensiva , Pneumonia Associada à Ventilação Mecânica/epidemiologia , Pneumonia Associada à Ventilação Mecânica/etiologia , Prevalência , Respiração Artificial/efeitos adversos , Estudos Retrospectivos
17.
J Sports Sci ; 35(21): 2114-2120, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27879169

RESUMO

The present study examined the ability of an interpersonal construct called athletic connectedness to mediate the relationship between task and ego goal orientations and well-being. We operationalised athletic social connectedness as a sense of social belonging and sense of connection with teammates. We hypothesised that athletic social connectedness would be positively associated with task goals, negatively associated with ego goals, and would at least partially mediate the relationship between achievement goals and well-being. We administered questionnaires to female (N = 106; mean age = 20.47, SD = 1.12) and male (N = 100; mean age = 20.95, SD = 1.21) NCAA Division III college athletes. We tested our hypothesised model using structural equation modelling, which included testing a measurement model that specified four latent variables and then comparing the estimates generated by our hypothesised model with our data. We also tested three alternative models and found our hypothesised model to fit best. As predicted, there were significant indirect effects of task and ego motivation on well-being through athletic connectedness, demonstrating formal evidence of mediation. The r2 coefficient indicated that the model explained 30% of the variance in well-being, a moderate effect size (Cohen, 1988). Discussion focuses on the importance of considering interpersonal constructs as a way to improve our understanding of relationship between task and ego goal orientations to well-being in athletes.


Assuntos
Atletas/psicologia , Ego , Objetivos , Relações Interpessoais , Motivação , Feminino , Humanos , Masculino , Adulto Jovem
18.
Clin Anat ; 30(3): 362-372, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28195378

RESUMO

Childbirth can be a traumatic experience on the female body. Some techniques may be implemented to make the process smoother and decrease the potential lacerations that can occur. Episiotomies have been used by obstetricians and midwives to help make the fetal decent down the vaginal canal less turbulent. A physician must use his best judgment on when it is necessary to make this incision and what form of incision to make. Before making an incision one must understand the female external and internal anatomy and thoroughly comprehend the stages of birth to understand how and what complications can occur. Even though an episiotomy is a minor incision, it is still a surgical incision nonetheless and as with any form of surgery there are both risks and benefits that are to be considered. Nevertheless, episiotomies have proven to help ease births that are complicated by shoulder dystocia, prevent severe lacerations, and decrease the second stage of labor. The following comprehensive review provides a description of the female anatomy, as well as an extensive description of why, when, and how an episiotomy is done. Clin. Anat. 30:362-372, 2017. © 2017 Wiley Periodicals, Inc.


Assuntos
Parto Obstétrico/efeitos adversos , Episiotomia/métodos , Genitália Feminina/embriologia , Períneo/cirurgia , Episiotomia/efeitos adversos , Episiotomia/história , Feminino , História do Século XVIII , História do Século XIX , História do Século XX , História do Século XXI , Humanos , Segunda Fase do Trabalho de Parto/fisiologia , Lacerações/prevenção & controle , Períneo/anatomia & histologia , Gravidez , Fatores de Risco
20.
Circ Res ; 111(9): 1222-36, 2012 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-23065345

RESUMO

Ischemic heart disease is a significant cause of morbidity and mortality in Western society. Although interventions, such as thrombolysis and percutaneous coronary intervention, have proven efficacious in ischemia and reperfusion injury, the underlying pathological process of ischemic heart disease, laboratory studies suggest further protection is possible, and an expansive research effort is aimed at bringing new therapeutic options to the clinic. Mitochondrial dysfunction plays a key role in the pathogenesis of ischemia and reperfusion injury and cardiomyopathy. However, despite promising mitochondria-targeted drugs emerging from the laboratory, very few have successfully completed clinical trials. As such, the mitochondrion is a potential untapped target for new ischemic heart disease and cardiomyopathy therapies. Notably, there are a number of overlapping therapies for both these diseases, and as such novel therapeutic options for one condition may find use in the other. This review summarizes efforts to date in targeting mitochondria for ischemic heart disease and cardiomyopathy therapy and outlines emerging drug targets in this field.


Assuntos
Cardiomiopatias/fisiopatologia , Fármacos Cardiovasculares/farmacologia , Mitocôndrias Cardíacas/efeitos dos fármacos , Isquemia Miocárdica/fisiopatologia , Animais , Cardiomiopatias/tratamento farmacológico , Fármacos Cardiovasculares/uso terapêutico , Modelos Animais de Doenças , Humanos , Mitocôndrias Cardíacas/fisiologia , Isquemia Miocárdica/tratamento farmacológico , Resultado do Tratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA