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2.
Nat Methods ; 18(3): 309-315, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33649587

RESUMO

The microscopic visualization of large-scale three-dimensional (3D) samples by optical microscopy requires overcoming challenges in imaging quality and speed and in big data acquisition and management. We report a line-illumination modulation (LiMo) technique for imaging thick tissues with high throughput and low background. Combining LiMo with thin tissue sectioning, we further develop a high-definition fluorescent micro-optical sectioning tomography (HD-fMOST) method that features an average signal-to-noise ratio of 110, leading to substantial improvement in neuronal morphology reconstruction. We achieve a >30-fold lossless data compression at a voxel resolution of 0.32 × 0.32 × 1.00 µm3, enabling online data storage to a USB drive or in the cloud, and high-precision (95% accuracy) brain-wide 3D cell counting in real time. These results highlight the potential of HD-fMOST to facilitate large-scale acquisition and analysis of whole-brain high-resolution datasets.


Assuntos
Encéfalo/diagnóstico por imagem , Imageamento Tridimensional/métodos , Microscopia/métodos , Microtomia/métodos , Razão Sinal-Ruído , Tomografia/métodos
4.
BMC Pulm Med ; 21(1): 38, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33482796

RESUMO

BACKGROUND: Clinical management of COVID-19 requires close monitoring of lung function. While computed tomography (CT) offers ideal way to identify the phenotypes, it cannot monitor the patient response to therapeutic interventions. We present a case of ventilation management for a COVID-19 patient where electrical impedance tomography (EIT) was used to personalize care. CASE PRESENTATION: The patient developed acute respiratory distress syndrome, required invasive mechanical ventilation, and was subsequently weaned. EIT was used multiple times: to titrate the positive end-expiratory pressure, understand the influence of body position, and guide the support levels during weaning and after extubation. We show how EIT provides bedside monitoring of the patient´s response to various therapeutic interventions and helps guide treatments. CONCLUSION: EIT provides unique information that may help the ventilation management in the pandemic of COVID-19.


Assuntos
/diagnóstico por imagem , Impedância Elétrica , Pulmão/diagnóstico por imagem , Posicionamento do Paciente/métodos , Respiração Artificial/métodos , Tomografia/métodos , /fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Respiração com Pressão Positiva/métodos , /terapia , Desmame do Respirador/métodos
5.
Methods Mol Biol ; 2247: 271-286, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33301123

RESUMO

Super-resolution fluorescence microscopy allows imaging macromolecular complexes down to the nanoscopic scale and thus is a great tool to combine and integrate cellular imaging in the native cellular environment with structural analysis by X-ray crystallography or high-resolution cryo electron microscopy or tomography. Here we describe practical aspects of SMLM imaging by dSTORM, from the initial sample preparation using mounting media, antibodies and fluorescent markers, the experimental setup for data acquisition including multi-color colocalization and 3D data acquisition, and finally tips and clues on advanced data processing that includes image reconstruction and data segmentation using 2D or 3D clustering methods. This approach opens the path toward multi-resolution integration in cellular structural biology.


Assuntos
Microscopia Crioeletrônica/métodos , Substâncias Macromoleculares/química , Microscopia de Fluorescência/métodos , Imagem Molecular , Tomografia/métodos , Animais , Linhagem Celular , Células Cultivadas , Análise de Dados , Imunofluorescência , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Microscopia de Fluorescência/normas
6.
Medicine (Baltimore) ; 99(46): e23116, 2020 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-33181681

RESUMO

A recent paper in the journal Neuroreport suggested that, upon source localization, the semantic P600 localizes to executive function areas, that is, outside language. But is this true for all types of linguistic P600? We report a cross-sectional source localization study of a classical (agreement) syntactic paradigm.The results show a clear localization to the temporal lobe, in classical language areas.The P600 is probably not a unitary phenomenon in term of source localization, and the question whether it localizes within or outside the language system depends on the type of P600.


Assuntos
Mapeamento Encefálico/métodos , Potenciais Evocados/fisiologia , Idioma , Semântica , Lobo Temporal , Adulto , Compreensão/fisiologia , Eletroencefalografia/métodos , Fenômenos Eletromagnéticos , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiopatologia , Tomografia/métodos
7.
Rev. bras. oftalmol ; 79(5): 341-343, set.-out. 2020. graf
Artigo em Português | LILACS | ID: biblio-1137983

RESUMO

Resumo Descrição de relato de caso de paciente com ceratocone (KC), Distrofia Endotelial de Fuchs (DEF) e catarata concomitantes com descompensação corneana submetido a Ceratoplastia Lamelar Posterior pela técnica Descemet's Membrane Endothelial Keratoplasty (DMEK) associado a facoemulsificação com implante de lente intraocular (LIO). Observou-se aplanamento corneano significativo no pós-operatório e acuidade visual final sem correção de 20/25 . Destaca-se a possibilidade do DMEK como alternativa à Ceratoplastia Penetrante (Penetrating Keratoplasty - PK) em casos de DEF e KC associados. Aplanamento corneano pode ocorrer neste grupo de pacientes, o que pode resultar em imprevisibilidade refracional no cálculo do poder da LIO ao se optar por facectomia combinada. Neste relato, apesar da modificação da curvatura corneana após cirurgia combinada de DMEK com facectomia, a acuidade visual final sem correção foi satisfatória, demonstrando a possibilidade de sucesso desta abordagem na coexistência de DEF, KC e Catarata. Entretanto, a possibilidade de mudança significativa na curvatura corneana deve ser considerada em pacientes com KC, edema de córnea secundário a DEF e catarata, na decisão de cirurgia simultânea ou em dois tempos.


Abstract This is a case report of a patient with concomitant Keratoconus (KC), Fuchs Endothelial Dystrophy (FED) and cataract with corneal decompensation submitted to Posterior Lamellar Corneal surgery (Descemet's Membrane Endothelial Keratoplasty - DMEK) associated with phacoemulsification with intraocular lens (IOL) implantation. Corneal flattening and uncorrected visual acuity of 20/25 was observed in the postoperative period. We reasure the viability of DMEK as an alternative to Penetrating Keratoplasty (PK) in cases of associated DEF and KC associated. Changes in corneal curvature may occur in this group of patients and lead to the possibility of refractive unpredictability in IOL calculation when performing a combined cataract surgery. Despite unexpected corneal flattening, satisfactory final visual acuity was achieved, demonstrating the possibility of success of this approach in the coexistence of the three conditions. Nonetheless, the possibility of corneal curvature changes should be considered in patients with KC and corneal decompensation due to FED in decision making, regarding simultaneous or sequential surgical approach.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Tomografia/métodos , Distrofia Endotelial de Fuchs/cirurgia , Facoemulsificação/métodos , Ceratoplastia Endotelial com Remoção da Lâmina Limitante Posterior/métodos , Ceratocone/cirurgia , Lentes Intraoculares
9.
Semin Cardiothorac Vasc Anesth ; 24(4): 287-292, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32924792

RESUMO

At the end of 2019, a novel coronavirus (COVID-19) was identified as the cause of a cluster of pneumonia cases, with high needs of mechanical ventilation in critically ill patients. It is still unclear whether different types of COVID-19 pneumonia require different ventilator strategies. With electrical impedance tomography (EIT) we evaluated, in real time and bedside, the distribution of ventilation in the different pulmonary regions before, during, and after pronation in COVID-19 respiratory failure. We present a brief literature review of EIT in non-COVID-19 patients and a report of 2 COVID-19 patients: one that did not respond well and another one that improved during and after pronation. EIT might be a useful tool to decide whether prone positioning should or should not be used in COVID-19 pneumonia.


Assuntos
Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/terapia , Impedância Elétrica , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/terapia , Respiração Artificial/métodos , Tomografia/métodos , Idoso , Betacoronavirus , Evolução Fatal , Humanos , Masculino , Pandemias , Decúbito Ventral
11.
Physiol Meas ; 41(8): 085008, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32736369

RESUMO

OBJECTIVE: Patients with the novel coronavirus disease (COVID-19) often have airway secretions that severely compromise ventilation. This study investigates electrical impedance tomography (EIT) monitoring of a therapeutic bronchoalveolar lavage (BAL) in a patient with COVID-19. APPROACH: A patient with COVID-19 developed acute respiratory distress syndrome requiring mechanical ventilation. He received regional BAL to remove mucus in the small airways (20 ml × 5). Regional ventilation changes before BAL, 30 min after and in the following days, were monitored with EIT. MAIN RESULTS: Regional ventilation worsened shortly after BAL and improved in the following days. The improvement of the oxygenation did not exactly match the ventilation improvement, which indicated a possible ventilation/perfusion mismatch. SIGNIFICANCE: Therapeutic BAL might improve regional ventilation for COVID-19 and EIT could be a useful tool at the bedside to monitor the ventilation treatment of COVID-19.


Assuntos
Betacoronavirus , Lavagem Broncoalveolar/métodos , Infecções por Coronavirus/terapia , Impedância Elétrica/uso terapêutico , Monitorização Fisiológica/métodos , Pneumonia Viral/terapia , Respiração Artificial/métodos , Idoso , Infecções por Coronavirus/complicações , Infecções por Coronavirus/diagnóstico por imagem , Humanos , Masculino , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/diagnóstico por imagem , /etiologia , Tomografia/métodos
14.
Phys Med Biol ; 65(18): 185013, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32442999

RESUMO

The magnetic particle imaging (MPI) performance of collections of chains of magnetic nanoparticles with Néel and Brownian relaxation mechanisms was studied by carrying out simulations based on the Landau-Lifshitz-Gilbert equation and rotational Brownian dynamics, respectively. The effect of magnetic dipole-dipole interactions within chains on the time-domain average magnetic dipole moment and corresponding dynamic hysteresis loops, harmonic spectra, and point spread functions (PSFs) of the particle chains was evaluated. The results show that interactions within chains lead to 'square-like' dynamic hysteresis loops and enhanced MPI performance, compared to chains of non-interacting nanoparticles. For nanoparticles with the Brownian relaxation mechanism, subjected to a superimposed alternating and ramping magnetic field mimicking the magnetic field in MPI applications, we studied the dependence of x-space MPI performance of particle chains on parameters such as the amplitude of the alternating magnetic field, surface-to-surface separation between nanoparticles, solvent viscosity, and the number of nanoparticles in a chain. The results illustrate that magnetic dipole-dipole interactions within a chain contribute to enhanced MPI performance, and also suggest that there exist optimal values of the above parameters that lead to the best x-space MPI performance, i.e. maximum peak signal intensity and smallest full-width-at-half-maximum in PSFs.


Assuntos
Imãs/química , Nanopartículas , Tomografia/métodos , Campos Magnéticos , Solventes/química , Viscosidade
15.
Tunis Med ; 98(2): 131-137, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32395802

RESUMO

INTRODUCTION: The subdivision into two entities of papillary renal cell carcinoma (PRCC) was established on histological criteria. It's in fact possible to distinguish the two subtypes by the means of radiological and progressive data. The subtype 1 is associated with the favorable profile. The ultrasound and especially CT urography ensure an accurate diagnostic approach with substantial therapeutic and prognostic involvement. The aim of the study is to define the radiological features that distinguish the two subtypes of renal papillary carcinoma, and to study the radiological predictive factors of locoregional recurrence, metastases free survival and specific survival. METHODS: It's about a monocentric, retrospective study led between January 2005 and June 2017, gathering 49 cases of operated PRCC. The study concerned patients over the age of 18, who were diagnosed after anatomopathological examination of the operative specimen (enlarged nephrectomy or conservative surgery). Cases in which diagnosis was made by renal biopsy were excluded. The comparative study concerned ultrasound and CT scan data. Univariate and multivariate analysis were performed to determine factors having a prognostic value in terms of locoregional recurrence, metastases-free and specific survival. RESULTS: On the ultrasound, the subtype 1 tumors were significantly homogenous with regular contours. Tumors were globally spontaneously hypodense and hypo vascular in 97,8% of cases. Enhancement was significantly more heterogonous for subtype 2 (p=0,01). Intratumoral necrosis and adenomegalies were associated with subtype 2 (p=0,0001 and 0,005). The predictive factors of locoregional recurrence, metastases-free survival and specific survival in univariate analysis were the contours' aspect, moderate enhancement and the presence of adenomegalies. On multivariate analysis, only the irregular contours were retained for locoregional recurrence-free survival and specific survival. CONCLUSIONS: Significant differences between the PRCC subtypes were observed when studying the radiological data. Irregular contours, adenomegalies and enhancement degree seemed to predict the progression of PRCC after curative surgery.


Assuntos
Carcinoma de Células Renais/diagnóstico , Diagnóstico por Imagem/métodos , Neoplasias Renais/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Carcinoma de Células Renais/cirurgia , Tratamento Conservador/efeitos adversos , Tratamento Conservador/métodos , Feminino , Humanos , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/etiologia , Estadiamento de Neoplasias , Nefrectomia/efeitos adversos , Nefrectomia/métodos , Valor Preditivo dos Testes , Prognóstico , Estudos Retrospectivos , Tomografia/métodos , Ultrassonografia/métodos , Adulto Jovem
16.
Proc Natl Acad Sci U S A ; 117(21): 11217-11219, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32393617

RESUMO

Understanding the timing and mechanisms of amino acid synthesis and racemization on asteroidal parent bodies is key to demonstrating how amino acids evolved to be mostly left-handed in living organisms on Earth. It has been postulated that racemization can occur rapidly dependent on several factors, including the pH of the aqueous solution. Here, we conduct nanoscale geochemical analysis of a framboidal magnetite grain within the Tagish Lake carbonaceous chondrite to demonstrate that the interlocking crystal arrangement formed within a sodium-rich, alkaline fluid environment. Notably, we report on the discovery of Na-enriched subgrain boundaries and nanometer-scale Ca and Mg layers surrounding individual framboids. These interstitial coatings would yield a surface charge state of zero in more-alkaline fluids and prevent assimilation of the individual framboids into a single grain. This basic solution would support rapid synthesis and racemization rates on the order of years, suggesting that the low abundances of amino acids in Tagish Lake cannot be ascribed to fluid chemistry.


Assuntos
Aminoácidos , Meteoroides , Sódio/química , Água/química , Aminoácidos/biossíntese , Aminoácidos/síntese química , Colúmbia Britânica , Cálcio/química , Óxido Ferroso-Férrico/química , Concentração de Íons de Hidrogênio , Lagos , Magnésio/química , Estereoisomerismo , Tomografia/métodos
17.
PLoS One ; 15(4): e0231179, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32240256

RESUMO

Site-specific atom probe tomography (APT) from aluminum alloys has been limited by sample preparation issues. Indeed, Ga, which is conventionally used in focused-ion beam (FIB) preparations, has a high affinity for Al grain boundaries and causes their embrittlement. This leads to high concentrations of Ga at grain boundaries after specimen preparation, unreliable compositional analyses and low specimen yield. Here, to tackle this problem, we propose to use cryo-FIB for APT specimen preparation specifically from grain boundaries in a commercial Al-alloy. We demonstrate how this setup, easily implementable on conventional Ga-FIB instruments, is efficient to prevent Ga diffusion to grain boundaries. Specimens were prepared at room temperature and at cryogenic temperature (below approx. 90K) are compared, and we confirm that at room temperature, a compositional enrichment above 15 at.% of Ga is found at the grain boundary, whereas no enrichment could be detected for the cryo-prepared sample. We propose that this is due to the decrease of the diffusion rate of Ga at low temperature. The present results could have a high impact on the understanding of aluminum and Al-alloys.


Assuntos
Ligas/química , Alumínio/química , Tomografia/métodos , Gálio/química , Íons , Temperatura
18.
Rev. medica electron ; 42(2): 1735-1742, mar.-abr. 2020. graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1127031

RESUMO

Resumen Las fracturas del Atlas representan el segundo tipo más común de lesiones de la columna cervical alta. Con este trabajo se persigue describir la fijación occipito-cervical como tratamiento de la fractura de atlas tipo Jefferson inestable. Se presenta paciente que sufre trauma raquimedular, después de aplicarle un minucioso examen físico y la tomografía axial computada de columna cervical se detecta una fractura tipo Jefferson de atlas con más de 7 mm de separación de sus fragmentos. Al ser esta una fractura inestable de la región cervical alta se decide realizar una fijación occipito-cervical como método de tratamiento de esta lesión. La evolución postquirúrgica del paciente transcurrió sin complicaciones (AU).


Summary Atlas fractures represent the second most common type of upper cervical spine injury. This work aims to describe the occipito-cervical fixation as a treatment for the unstable Jefferson-type atlas fracture. A patient suffering from spinal cord trauma is presented, after applying a thorough physical examination and the computed tomography of the cervical spine, a Jefferson type fracture of atlas with more than 7 mm of separation of its fragments is detected. As this is an unstable fracture of the upper cervical region, it was decided to perform an occipito-cervical fixation as a treatment method for this lesion. The postoperative evolution of the patient was uneventful (AU).


Assuntos
Humanos , Masculino , Adulto , Atlas Cervical/lesões , Terapêutica/métodos , Dispositivos de Fixação Ortopédica , Tomografia/métodos , Técnicas , Fraturas Ósseas/diagnóstico , Fraturas Ósseas/terapia
19.
Sci Rep ; 10(1): 4903, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184401

RESUMO

Most imaging studies of immunotherapy have focused on tracking labeled T cell biodistribution in vivo for understanding trafficking and homing parameters and predicting therapeutic efficacy by the presence of transferred T cells at or in the tumour mass. Conversely, we investigate here a novel concept for longitudinally elucidating anatomical and pathophysiological changes of solid tumours after adoptive T cell transfer in a preclinical set up, using previously unexplored in-tandem macroscopic and mesoscopic optoacoustic (photoacoustic) imaging. We show non-invasive in vivo observations of vessel collapse during tumour rejection across entire tumours and observe for the first time longitudinal tumour rejection in a label-free manner based on optical absorption changes in the tumour mass due to cellular decline. We complement these observations with high resolution episcopic fluorescence imaging of T cell biodistribution using optimized T cell labeling based on two near-infrared dyes targeting the cell membrane and the cytoplasm. We discuss how optoacoustic macroscopy and mesoscopy offer unique contrast and immunotherapy insights, allowing label-free and longitudinal observations of tumour therapy. The results demonstrate optoacoustic imaging as an invaluable tool in understanding and optimizing T cell therapy.


Assuntos
Imunoterapia/métodos , Linfócitos T/citologia , Linfócitos T/imunologia , Tomografia/métodos , Animais , Linhagem Celular , Galinhas , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Camundongos , Técnicas Fotoacústicas/métodos
20.
Am J Ophthalmol ; 215: 91-103, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32112772

RESUMO

PURPOSE: To determine if agreement between subjective interpretations of Scheimpflug tomography maps of corneas with Fuchs endothelial corneal dystrophy (FECD) is affected by daily and hourly changes in corneal edema. DESIGN: Reliability analysis. METHODS: Scheimpflug imaging pachymetry and posterior elevation maps of corneas with a range of severity of FECD were evaluated in a randomized manner for the presence of 3 tomographic features of edema. Agreement between interpretations of 1 masked observer was assessed (percentage, and κ-statistic with 95% confidence interval) for images taken within minutes on the same day, for images taken at a similar time on a different day, and for images taken over the course of a morning. Intra- and interobserver agreement was also assessed. RESULTS: Interpretations for individual tomographic features agreed for ≥88% of images (κ ≥ 0.75) taken within minutes on the same day; complete disagreement (ie, disagreement for all 3 tomographic features in an image) occurred in ≤3% of images. Interpretations agreed for ≥77% of images (κ ≥ 0.52) taken at a similar time on a different day; complete disagreement did not occur. Interpretations agreed for ≥81% of images (κ ≥ 0.61) taken over the course of a morning; complete disagreement occurred in ≤6% of images. Intraobserver agreement was ≥93% (κ ≥ 0.83) and interobserver agreement was ≥93% (κ ≥ 0.66); complete disagreement did not occur. CONCLUSIONS: Subjective interpretation of Scheimpflug images in FECD is highly repeatable for disease classification. Although small variations in interpretations resulted from pathophysiologic changes in corneal hydration and other factors, clinically significant disagreements in interpretation were uncommon and therefore unlikely to affect clinical decision-making.


Assuntos
Edema da Córnea/diagnóstico , Distrofia Endotelial de Fuchs/diagnóstico , Tomografia/métodos , Idoso , Paquimetria Corneana , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Microscopia com Lâmpada de Fenda , Acuidade Visual
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