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1.
J Emerg Med ; 66(5): e555-e561, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38580514

RESUMO

BACKGROUND: Management of acute shoulder dislocation in the emergency department (ED) is common. OBJECTIVE: This study describes the rate, risk factors, and length of stay (LOS) associated with shoulder dislocation reduction failure in the ED. METHODS: The study was a retrospective case-control study of patients 18 years and older presenting to the ED with acute shoulder dislocation who underwent attempted reduction. Patients with successful reduction on post-reduction first confirmatory imaging are compared with those requiring multiple attempts. RESULTS: Of 398 ED encounters when a shoulder reduction was attempted in the ED, 18.8% (75/398 [95% CI 15.2-22.9%]) required multiple reduction attempts. Patients with successful reduction on first confirmatory imaging were more commonly male (80.2% [95% CI 75.6-84.3%] vs. 68.0% [95% CI 56.8-77.8%]; p = 0.0220), discharged home from the ED (95.4% [95% CI 92.6-97.3%] vs. 84.0% [95% CI 74.4-91.0%]; p = 0.0004), reduced using a traction/countertraction technique (42.1% [95% CI 36.8-47.6%] vs. 29.3% [95% CI 19.9-40.4%]; p = 0.0415), and less likely to have a pre-reduction fracture (26.0% [95% CI 21.4-31.0%] vs. 45.3% [95% CI 34.4-56.7%]; p = 0.0010). Mean length of stay (LOS) for those with successful reduction on first confirmatory imaging was 2 hours and 8 minutes shorter than for those with more than one attempt (p < 0.001). CONCLUSIONS: The rate of failed first-pass reduction is higher than previously reported. Furthermore, the ED LOS was significantly longer in patients requiring multiple attempts. Knowledge of the failure rate and risk factors may raise physician awareness and guide future studies evaluating approaches for verification of reduction success.


Assuntos
Serviço Hospitalar de Emergência , Tempo de Internação , Luxação do Ombro , Humanos , Serviço Hospitalar de Emergência/organização & administração , Serviço Hospitalar de Emergência/estatística & dados numéricos , Masculino , Estudos Retrospectivos , Feminino , Luxação do Ombro/terapia , Luxação do Ombro/diagnóstico por imagem , Estudos de Casos e Controles , Pessoa de Meia-Idade , Tempo de Internação/estatística & dados numéricos , Adulto , Idoso , Manipulação Ortopédica/métodos , Manipulação Ortopédica/estatística & dados numéricos , Fatores de Risco
2.
Clin Pract Cases Emerg Med ; 8(1): 34-37, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38546308

RESUMO

Introduction: Thyroid storm is a rare but potentially life-threatening metabolic disorder that presents unique management challenges in the emergency department. Thionamides are commonly used as monotherapy for first-line treatment of hyperthyroidism. Case Report: In this case, a 26-year-old male presented to the emergency department with sore throat, fever, and diarrhea. He was found to have thyrotoxicosis as well as methimazole-induced bone marrow suppression resulting in agranulocytosis. Conclusion: Thyroid storm is a rare condition that carries a high risk of mortality and can further compromise a patient's immune system due to complications of common treatment modalities. It can potentially be misdiagnosed as sepsis due to tachycardia, febrile state, and tachypnea. This case report includes a discussion of diagnostic studies, as well as medical and surgical treatment modalities that led to the patient's recovery.

4.
Proc Natl Acad Sci U S A ; 119(19): e2119831119, 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35512093

RESUMO

SignificanceAstronomical observations indicate that dynamically important magnetic fields are ubiquitous in the Universe, while their origin remains a profound mystery. This work provides a paradigm for understanding the origin of cosmic magnetism by taking into account the effects of the microphysics of collisionless plasmas on macroscopic astrophysical processes. We demonstrate that the first magnetic fields can be spontaneously generated in the Universe by generic motions of astrophysical turbulence through kinetic plasma physics, and cosmic plasmas are thereby ubiquitously magnetized. Our theoretical and numerical results set the stage for determining how these "seed" magnetic fields are further amplified by the turbulent dynamo (another central and long-standing question) and thus advance a fully self-consistent explanation of cosmic magnetogenesis.

5.
Proc Natl Acad Sci U S A ; 118(11)2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33729988

RESUMO

Understanding magnetic-field generation and amplification in turbulent plasma is essential to account for observations of magnetic fields in the universe. A theoretical framework attributing the origin and sustainment of these fields to the so-called fluctuation dynamo was recently validated by experiments on laser facilities in low-magnetic-Prandtl-number plasmas ([Formula: see text]). However, the same framework proposes that the fluctuation dynamo should operate differently when [Formula: see text], the regime relevant to many astrophysical environments such as the intracluster medium of galaxy clusters. This paper reports an experiment that creates a laboratory [Formula: see text] plasma dynamo. We provide a time-resolved characterization of the plasma's evolution, measuring temperatures, densities, flow velocities, and magnetic fields, which allows us to explore various stages of the fluctuation dynamo's operation on seed magnetic fields generated by the action of the Biermann-battery mechanism during the initial drive-laser target interaction. The magnetic energy in structures with characteristic scales close to the driving scale of the stochastic motions is found to increase by almost three orders of magnitude and saturate dynamically. It is shown that the initial growth of these fields occurs at a much greater rate than the turnover rate of the driving-scale stochastic motions. Our results point to the possibility that plasma turbulence produced by strong shear can generate fields more efficiently at the driving scale than anticipated by idealized magnetohydrodynamics (MHD) simulations of the nonhelical fluctuation dynamo; this finding could help explain the large-scale fields inferred from observations of astrophysical systems.

6.
Ann Thorac Surg ; 107(4): 1017-1023, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30481513

RESUMO

BACKGROUND: Barrett's esophagus (BE)-intestinal metaplasia in the esophagus-may progress to low-grade dysplasia (LGD), high-grade dysplasia (HGD), and ultimately, invasive esophageal adenocarcinoma (EAC). The course of BE in immunosuppressed lung transplant recipients is unknown. METHODS: This study retrospectively reviewed the records of patients who underwent lung transplant at a single center, Norton Thoracic Institute in Phoenix, Arizona, between January 1, 2010 and October 31, 2016. Pretransplant esophagram, esophagogastroduodenoscopy, 24-hour pH monitoring, high-resolution manometry, and gastric emptying studies were analyzed. RESULTS: Of the 466 patients who underwent lung transplant during the study period, 54 (11.59%) had BE on pretransplant esophagogastroduodenoscopy. Of these, 1 patient had HGD before lung transplant. The median age of patients was 64 years (interquartile range, 58.25 to 68.75 years); 66.7% were men. Median follow-up duration was 29.48 months (interquartile range, 19.69 to 37.98 months). Sixteen of 54 patients (29.62%) underwent antireflux surgery after lung transplant. LGD or EAC developed in 3 patients during posttransplant surveillance. One patient had a diagnosis of HGD 24 months after retransplant. She underwent complete endoscopic ablation and was dysplasia-free for 5 months, but ultimately the condition recurred, and she underwent esophagectomy for invasive cancer. Two patients had a diagnosis of LGD 7 and 13 months after lung transplant and were successfully treated with radiofrequency ablation. The rate of progression to dysplasia or EAC was 2.3% per patient-year. CONCLUSIONS: BE seems to be more prevalent in lung transplant recipients than in the general population. The study findings suggest that patients with BE have a higher risk of BE-to-EAC progression after lung transplant and that HGD may progress rapidly in immunosuppressed patients. More intensive surveillance endoscopy may be required in patients with BE after lung transplant.


Assuntos
Adenocarcinoma/patologia , Esôfago de Barrett/patologia , Neoplasias Esofágicas/patologia , Hospedeiro Imunocomprometido , Transplante de Pulmão/métodos , Lesões Pré-Cancerosas/patologia , Centros Médicos Acadêmicos , Adenocarcinoma/epidemiologia , Adenocarcinoma/cirurgia , Idoso , Arizona , Esôfago de Barrett/epidemiologia , Esôfago de Barrett/cirurgia , Transformação Celular Neoplásica/patologia , Estudos de Coortes , Intervalo Livre de Doença , Neoplasias Esofágicas/epidemiologia , Neoplasias Esofágicas/cirurgia , Esofagectomia/métodos , Esofagectomia/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Transplante de Pulmão/mortalidade , Masculino , Pessoa de Meia-Idade , Prevalência , Prognóstico , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida
7.
Mon Not R Astron Soc ; 486(3): 4013-4029, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35136273

RESUMO

We present a systematic shearing-box investigation of MRI-driven turbulence in a weakly collisional plasma by including the effects of an anisotropic pressure stress, i.e. anisotropic (Braginskii) viscosity. We constrain the pressure anisotropy (Δp) to lie within the stability bounds that would be otherwise imposed by kinetic microinstabilities. We explore a broad region of parameter space by considering different Reynolds numbers and magnetic-field configurations, including net vertical flux, net toroidal-vertical flux and zero net flux. Remarkably, we find that the level of turbulence and angular-momentum transport are not greatly affected by large anisotropic viscosities: the Maxwell and Reynolds stresses do not differ much from the MHD result. Angular-momentum transport in Braginskii MHD still depends strongly on isotropic dissipation, e.g., the isotropic magnetic Prandtl number, even when the anisotropic viscosity is orders of magnitude larger than the isotropic diffusivities. Braginskii viscosity nevertheless changes the flow structure, rearranging the turbulence to largely counter the parallel rate of strain from the background shear. We also show that the volume-averaged pressure anisotropy and anisotropic viscous transport decrease with increasing isotropic Reynolds number (Re); e.g., in simulations with net vertical field, the ratio of anisotropic to Maxwell stress (α A/α M) decreases from ~ 0.5 to ~ 0.1 as we move from Re ~ 103 to Re ~ 104, while 〈4πΔp/B 2〉 → 0. Anisotropic transport may thus become negligible at high Re. Anisotropic viscosity nevertheless becomes the dominant source of heating at large Re, accounting for ≳50% of the plasma heating. We conclude by briefly discussing the implications of our results for RIAFs onto black holes.

8.
Phys Rev Lett ; 117(23): 235101, 2016 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-27982637

RESUMO

We present results from the first 3D kinetic numerical simulation of magnetorotational turbulence and dynamo, using the local shearing-box model of a collisionless accretion disk. The kinetic magnetorotational instability grows from a subthermal magnetic field having zero net flux over the computational domain to generate self-sustained turbulence and outward angular-momentum transport. Significant Maxwell and Reynolds stresses are accompanied by comparable viscous stresses produced by field-aligned ion pressure anisotropy, which is regulated primarily by the mirror and ion-cyclotron instabilities through particle trapping and pitch-angle scattering. The latter endow the plasma with an effective viscosity that is biased with respect to the magnetic-field direction and spatiotemporally variable. Energy spectra suggest an Alfvén-wave cascade at large scales and a kinetic-Alfvén-wave cascade at small scales, with strong small-scale density fluctuations and weak nonaxisymmetric density waves. Ions undergo nonthermal particle acceleration, their distribution accurately described by a κ distribution. These results have implications for the properties of low-collisionality accretion flows, such as that near the black hole at the Galactic center.

9.
Physiol Rep ; 3(4)2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25921779

RESUMO

The mdx mouse model of Duchenne muscular dystrophy (DMD) is used to study disease mechanisms and potential treatments, but its pathology is less severe than DMD patients. Other mouse models were developed to more closely mimic the human disease based on knowledge that upregulation of utrophin has a protective effect in mdx muscle. An mdx:utrophin(-/-) (dko) mouse was created, which had a severe disease phenotype and a shortened life span. An mdx:utrophin(+/-) mouse was also created, which had an intermediate disease phenotype compared to the mdx and dko mice. To determine the usefulness of mdx:utrophin(+/-) mice for long-term DMD studies, limb muscle pathology and function were assessed across the life span of wild-type, mdx, mdx:utrophin(+/-), and dko mice. Muscle function assessment, specifically grip duration and rotarod performance, demonstrated that mdx:utrophin(+/-) mice were weaker for a longer time than mdx mice. Mean myofiber area was smaller in mdx:utrophin(+/-) mice compared to mdx mice at 12 months. Mdx:utrophin(+/-) mice had a higher percentage of centrally nucleated myofibers compared to mdx mice at 6 and 12 months. Collagen I and IV density was significantly higher in mdx:utrophin(+/-) muscle compared to mdx at most ages examined. Generally, mdx:utrophin(+/-) mice showed an intermediate disease phenotype over a longer time course compared to the mdx and dko mice. While they do not genetically mirror human DMD, mdx:utrophin(+/-) mice may be a more useful animal model than mdx or dko mice for investigating long-term efficacy of potential treatments when fibrosis or muscle function is the focus.

10.
PLoS One ; 9(1): e86424, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24466085

RESUMO

Extraocular muscles (EOM) have a strikingly different disease profile than limb skeletal muscles. It has long been known that they are spared in Duchenne (DMD) and other forms of muscular dystrophy. Despite many studies, the cause for this sparing is not understood. We have proposed that differences in myogenic precursor cell properties in EOM maintain normal morphology over the lifetime of individuals with DMD due to either greater proliferative potential or greater resistance to injury. This hypothesis was tested by exposing wild type and mdx:utrophin(+/-) (het) mouse EOM and limb skeletal muscles to 18 Gy gamma irradiation, a dose known to inhibit satellite cell proliferation in limb muscles. As expected, over time het limb skeletal muscles displayed reduced central nucleation mirrored by a reduction in Pax7-positive cells, demonstrating a significant loss in regenerative potential. In contrast, in the first month post-irradiation in the het EOM, myofiber cross-sectional areas first decreased, then increased, but ultimately returned to normal compared to non-irradiated het EOM. Central nucleation significantly increased in the first post-irradiation month, resembling the dystrophic limb phenotype. This correlated with decreased EECD34 stem cells and a concomitant increase and subsequent return to normalcy of both Pax7 and Pitx2-positive cell density. By two months, normal het EOM morphology returned. It appears that irradiation disrupts the normal method of EOM remodeling, which react paradoxically to produce increased numbers of myogenic precursor cells. This suggests that the EOM contain myogenic precursor cell types resistant to 18 Gy gamma irradiation, allowing return to normal morphology 2 months post-irradiation. This supports our hypothesis that ongoing proliferation of specialized regenerative populations in the het EOM actively maintains normal EOM morphology in DMD. Ongoing studies are working to define the differences in the myogenic precursor cells in EOM as well as the cellular milieu in which they reside.


Assuntos
Raios gama/efeitos adversos , Distrofia Muscular Animal/patologia , Músculos Oculomotores/patologia , Músculos Oculomotores/efeitos da radiação , Utrofina/metabolismo , Animais , Proliferação de Células/efeitos da radiação , Extremidades/patologia , Extremidades/efeitos da radiação , Proteínas de Homeodomínio/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/efeitos da radiação , Distrofia Muscular Animal/metabolismo , Músculos Oculomotores/metabolismo , Fator de Transcrição PAX7/metabolismo , Fenótipo , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/patologia , Células Satélites de Músculo Esquelético/efeitos da radiação , Células-Tronco/metabolismo , Células-Tronco/efeitos da radiação , Fatores de Transcrição/metabolismo , Proteína Homeobox PITX2
11.
J Agric Food Chem ; 59(4): 1051-7, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-21250694

RESUMO

Detecting and quantifying extra virgin olive adulteration is of great importance to the olive oil industry. Many spectroscopic methods in conjunction with multivariate analysis have been used to solve these issues. However, successes to date are limited as calibration models are built to a specific set of geographical regions, growing seasons, cultivars, and oil extraction methods (the composite primary condition). Samples from new geographical regions, growing seasons, etc. (secondary conditions) are not always correctly predicted by the primary model due to different olive oil and/or adulterant compositions stemming from secondary conditions not matching the primary conditions. Three Tikhonov regularization (TR) variants are used in this paper to allow adulterant (sunflower oil) concentration predictions in samples from geographical regions not part of the original primary calibration domain. Of the three TR variants, ridge regression with an additional 2-norm penalty provides the smallest validation sample prediction errors. Although the paper reports on using TR for model updating to predict adulterant oil concentration, the methods should also be applicable to updating models distinguishing adulterated samples from pure extra virgin olive oil. Additionally, the approaches are general and can be used with other spectroscopic methods and adulterants as well as with other agriculture products.


Assuntos
Contaminação de Alimentos/análise , Óleos de Plantas/química , Óleos de Plantas/classificação , Espectrometria de Fluorescência/métodos , Calibragem , Manipulação de Alimentos/métodos , Grécia , Azeite de Oliva , Óleos de Plantas/análise , Reprodutibilidade dos Testes , Óleo de Girassol
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