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1.
Nat Commun ; 11(1): 4928, 2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004791

RESUMO

High-altitude adaptation of Tibetans represents a remarkable case of natural selection during recent human evolution. Previous genome-wide scans found many non-coding variants under selection, suggesting a pressing need to understand the functional role of non-coding regulatory elements (REs). Here, we generate time courses of paired ATAC-seq and RNA-seq data on cultured HUVECs under hypoxic and normoxic conditions. We further develop a variant interpretation methodology (vPECA) to identify active selected REs (ASREs) and associated regulatory network. We discover three causal SNPs of EPAS1, the key adaptive gene for Tibetans. These SNPs decrease the accessibility of ASREs with weakened binding strength of relevant TFs, and cooperatively down-regulate EPAS1 expression. We further construct the downstream network of EPAS1, elucidating its roles in hypoxic response and angiogenesis. Collectively, we provide a systematic approach to interpret phenotype-associated noncoding variants in proper cell types and relevant dynamic conditions, to model their impact on gene regulation.


Assuntos
Aclimatação/genética , Cromatina/metabolismo , Grupos Étnicos/genética , Redes Reguladoras de Genes , Modelos Genéticos , Altitude , Doença da Altitude/etnologia , Doença da Altitude/genética , Doença da Altitude/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Hipóxia Celular/genética , Células Cultivadas , Cromatina/genética , Sequenciamento de Cromatina por Imunoprecipitação , Resistência à Doença/genética , Feminino , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Oxigênio/metabolismo , Polimorfismo de Nucleotídeo Único , Gravidez , Cultura Primária de Células , RNA-Seq , Elementos Reguladores de Transcrição/genética , Seleção Genética , Tibet/etnologia , Fatores de Transcrição/metabolismo , Sequenciamento Completo do Genoma
2.
Nat Commun ; 11(1): 5075, 2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-33033245

RESUMO

Nickel-iron composites are efficient in catalyzing oxygen evolution. Here, we develop a microorganism corrosion approach to construct nickel-iron hydroxides. The anaerobic sulfate-reducing bacteria, using sulfate as the electron acceptor, play a significant role in the formation of iron sulfide decorated nickel-iron hydroxides, which exhibit excellent electrocatalytic performance for oxygen evolution. Experimental and theoretical investigations suggest that the synergistic effect between oxyhydroxides and sulfide species accounts for the high activity. This microorganism corrosion strategy not only provides efficient candidate electrocatalysts but also bridges traditional corrosion engineering and emerging electrochemical energy technologies.


Assuntos
Desulfotomaculum/metabolismo , Hidróxidos/metabolismo , Níquel/metabolismo , Oxigênio/metabolismo , Corrosão , Teoria da Densidade Funcional , Eletroquímica , Eletrodos , Análise Espectral Raman , Espectroscopia por Absorção de Raios X
3.
Water Sci Technol ; 82(5): 954-966, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33031073

RESUMO

The sewage treatment system in this study was operated with only the first stage of a French system of vertical wetlands, composed of two units in parallel and running with an extended feeding cycle (7 days). This research sought to evaluate and relate continuous variables measured in situ (dissolved oxygen (DO), pH and redox potential) throughout the feeding cycle, with measurements at distinct heights along the filter vertical profile. Additionally, the influence of the surface organic sludge deposit was investigated. A close link between the hydraulic behaviour and the effluent quality was verified, with both being related to the batch volume and the instantaneous hydraulic loading rate. The drop in DO as the feed days progressed could be related to the loss of hydraulic conductivity. A thicker sludge layer decreased the aeration capacity of the filter. The effluent was observed to be aerated when percolating through the medium. DO and pH data suggested that nitrification varied along the filter depth, the batch duration and the feed cycle. The monitored parameters may be indicative of the behaviour of other parameters.


Assuntos
Esgotos , Áreas Alagadas , Clima , Nitrificação , Oxigênio
4.
Bull World Health Organ ; 98(9): 586-587, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33012857

RESUMO

The COVID 19 pandemic is exposing an important weakness in health systems: medical oxygen production and delivery. Tatum Anderson reports.


Assuntos
Infecções por Coronavirus/epidemiologia , Oxigênio/provisão & distribução , Pneumonia Viral/epidemiologia , África/epidemiologia , Betacoronavirus , Humanos , Pandemias
9.
Bull World Health Organ ; 98(9): 586-587, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: covidwho-814658

RESUMO

The COVID 19 pandemic is exposing an important weakness in health systems: medical oxygen production and delivery. Tatum Anderson reports.


Assuntos
Infecções por Coronavirus/epidemiologia , Oxigênio/provisão & distribução , Pneumonia Viral/epidemiologia , África/epidemiologia , Betacoronavirus , Humanos , Pandemias
10.
Artigo em Inglês | MEDLINE | ID: mdl-33017916

RESUMO

A sufficient oxygen supply of the fetus is necessary for a proper development of the organs. Transabdominal fetal pulse oximetry is a method that allows to measure the oxygenation of the fetal blood non-invasively by placing the light sources and photodetectors on the belly of the pregnant woman. The shape of the measured fetal pulse wave is needed to extract parameters for the estimation of the oxygen saturation. This work presents an extension of our previously presented signal processing strategy that allows to extract an average shape of the fetal pulse wave from noisy mixed photoplethysmograms (PPG) with dominating maternal and very weak fetal signal components. An adaptive noise canceller and a comb filter are used to suppress the maternal component. The quality of the resulting fetal signal is sufficient to identify single pulse waves in time domain. Further processing demonstrates the extraction of the mean shape of a single fetal pulse wave by synchronous averaging of several detected pulses. The method is evaluated with different datasets of several simulated and synthetic signals measured with a tissue mimicking phantom. The feasibility of the approach is demonstrated by preparing the mixed PPGs to perform fetal pulse oximetry in future studies. However, clinical measurements are needed to finally evaluate the proposed system beyond synthetic datasets.


Assuntos
Monitorização Fetal , Oxigênio , Feminino , Frequência Cardíaca , Humanos , Oximetria , Gravidez , Cuidado Pré-Natal
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 374-377, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018006

RESUMO

Continuous monitoring of blood oxygen saturation levels is vital for patients with pulmonary disorders. Traditionally, SpO2 monitoring has been carried out using transmittance pulse oximeters due to its dependability. However, SpO2 measurement from transmittance pulse oximeters is limited to peripheral regions. This becomes a disadvantage at very low temperatures as blood perfusion to the peripherals decreases. On the other hand, reflectance pulse oximeters can be used at various sites like finger, wrist, chest and forehead. Additionally, reflectance pulse oximeters can be scaled down to affordable patches that do not interfere with the user's diurnal activities. However, accurate SpO2 estimation from reflectance pulse oximeters is challenging due to its patient dependent, subjective nature of measurement. Recently, a Machine Learning (ML) method was used to model reflectance waveforms onto SpO2 obtained from transmittance waveforms. However, the generalizability of the model to new patients was not tested. In light of this, the current work implemented multiple ML based approaches which were subsequently found to be incapable of generalizing to new patients. Furthermore, a minimally calibrated data driven approach was utilized in order to obtain SpO2 from reflectance PPG waveforms. The proposed solution produces an average mean absolute error of 1.81% on unseen patients which is well within the clinically permissible error of 2%. Two statistical tests were conducted to establish the effectiveness of the proposed method.Clinical relevance- The proposed method ameliorates our current understanding of reflectance based pulse oximetry and provides a method to estimate SpO2 from reflectance pulse oximeters.


Assuntos
Oximetria , Oxigênio , Dedos , Testa , Humanos , Articulação do Punho
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1489-1492, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018273

RESUMO

Cerebrovascular Reactivity (CVR), the responsiveness of blood vessels to a vasodilatory stimulus, is an important indicator of cerebrovascular health. Assessing CVR with fMRI, we can measure the change in the Blood Oxygen Level Dependent (BOLD) response induced by a change in CO2 pressure (%BOLD/mmHg). However, there exists a temporal offset between the recorded CO2 pressure and the local BOLD response, due to both measurement and physiological delays. If this offset is not corrected for, voxel-wise CVR values will not be accurate. In this paper, we propose a framework for mapping hemodynamic lag in breath-hold fMRI data. As breath-hold tasks drive task-correlated head motion artifacts in BOLD fMRI data, our framework for lag estimation fits a model that includes polynomial terms and head motion parameters, as well as a shifted variant of the CO2 regressor (±9 s in 0.3 s increments), and the hemodynamic lag at each voxel is the shift producing the maximum total model R2 within physiological constraints. This approach is evaluated in 8 subjects with multi-echo fMRI data, resulting in robust maps of hemodynamic delay that show consistent regional variation across subjects, and improved contrast-to-noise compared to methods where motion regression is ignored or performed earlier in preprocessing.Clinical Relevance- We map hemodynamic lag using breathhold fMRI, providing insight into vascular transit times and improving the regional accuracy of cerebrovascular reactivity measurements.


Assuntos
Circulação Cerebrovascular , Imagem por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Hemodinâmica , Oxigênio
13.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2279-2282, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018462

RESUMO

Simulations that are meant to determine the steady-state distribution of a diffusible solute such as oxygen in tissues have typically used finite difference methods to solve the diffusion equation. Finite difference methods require a tissue mesh with enough points to resolve oxygen gradients near and between discrete blood vessels. The large number of points that are typically required can make these calculations very slow. In this paper, we investigate a numerical method known as the Green's function method which is not bound by the same constraint. The Green's function method is expected to yield an accurate oxygen distribution more quickly by requiring fewer mesh points. Both methods were applied to calculate the steady state oxygen distribution in a model simulation region. When the Green's function calculation used meshes with 1/2, 1/4 and, 1/8 of the resolution required for the finite-difference mesh, there was good agreement with the finite difference calculation in all cases. When the volume of the domain was increased 8-fold the Green's function method was able to calculate the O2 field in 22 minutes, whereas the finite difference calculation is expected to take approximately 1 week. The number of steps required for the Green's function calculation increases quadratically with the number of points in the tissue mesh. As a result, small meshes are calculated very quickly using Green's functions, while for larger mesh sizes this method experiences a significant decrease in efficiency.


Assuntos
Algoritmos , Oxigênio , Cor , Difusão , Fenômenos Físicos
14.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2788-2791, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018585

RESUMO

In this paper, we explored the link between sleep apnoea and cardiovascular disease (CVD) using a time-series statistical measure of sleep apnoea-related oxygen desaturation. We compared the performance of a hypoxic measure derived from the polysomnogram with the Apnoea Hypopnoea Index (AHI) in predicting CVD mortality in patients of the Sleep Heart Health Study.We estimated the relative cumulative time of SpO2 below 90% (Tr90) using pulse oximetry signals from polysomnogram recordings as the hypoxic measure of desaturation patterns. Then, the survival curves for hypoxia quintiles were evaluated for the prediction of CVD mortality and were compared with the results using AHI for prediction. We also calculated the Cox hazard ratios for Tr90 and AHI. Our results show that the Tr90 was a better predictor of CVD mortality outcomes than AHI.


Assuntos
Doenças Cardiovasculares , Síndromes da Apneia do Sono , Apneia Obstrutiva do Sono , Doenças Cardiovasculares/diagnóstico , Humanos , Oxigênio , Polissonografia , Síndromes da Apneia do Sono/diagnóstico , Apneia Obstrutiva do Sono/diagnóstico
15.
BMC Pulm Med ; 20(1): 269, 2020 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-33066765

RESUMO

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has spread to almost 100 countries, infected over 31 M patients and resulted in 961 K deaths worldwide as of 21st September 2020. The major clinical feature of severe COVID-19 requiring ventilation is acute respiratory distress syndrome (ARDS) with multi-functional failure as a result of a cytokine storm with increased serum levels of cytokines. The pathogenesis of the respiratory failure in COVID-19 is yet unknown, but diffuse alveolar damage with interstitial thickening leading to compromised gas exchange is a plausible mechanism. Hypoxia is seen in the COVID-19 patients, however, patients present with a distinct phenotype. Intracellular levels of nitric oxide (NO) play an important role in the vasodilation of small vessels. To elucidate the intracellular levels of NO inside of RBCs in COVID-19 patients compared with that of healthy control subjects. METHODS: We recruited 14 COVID-19 infected cases who had pulmonary involvement of their disease, 4 non-COVID-19 healthy controls (without pulmonary involvement and were not hypoxic) and 2 hypoxic non-COVID-19 patients subjects who presented at the Masih Daneshvari Hospital of Tehran, Iran between March-May 2020. Whole blood samples were harvested from patients and intracellular NO levels in 1 × 106 red blood cells (RBC) was measured by DAF staining using flow cytometry (FACS Calibour, BD, CA, USA). RESULTS: The Mean florescent of intensity for NO was significantly enhanced in COVID-19 patients compared with healthy control subjects (P ≤ 0.05). As a further control for whether hypoxia induced this higher intracellular NO, we evaluated the levels of NO inside RBC of hypoxic patients. No significant differences in NO levels were seen between the hypoxic and non-hypoxic control group. CONCLUSIONS: This pilot study demonstrates increased levels of intracellular NO in RBCs from COVID-19 patients. Future multi-centre studies should examine whether this is seen in a larger number of COVID-19 patients and whether NO therapy may be of use in these severe COVID-19 patients.


Assuntos
Dióxido de Carbono/metabolismo , Infecções por Coronavirus/metabolismo , Eritrócitos/metabolismo , Hipóxia/metabolismo , Óxido Nítrico/metabolismo , Oxigênio/metabolismo , Pneumonia Viral/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Assintomáticas , Betacoronavirus , Gasometria , Estudos de Casos e Controles , Infecções por Coronavirus/sangue , Infecções por Coronavirus/complicações , Feminino , Citometria de Fluxo , Humanos , Hipóxia/sangue , Hipóxia/etiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Pressão Parcial , Projetos Piloto , Pneumonia Viral/sangue , Pneumonia Viral/complicações , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/metabolismo , Vasodilatação , Adulto Jovem
17.
Rev. am. med. respir ; 20(3): 275-278, sept. 2020. ilus
Artigo em Espanhol | LILACS, BINACIS | ID: biblio-1123099

RESUMO

Se presenta el caso de un paciente con fibrosis quística, insuficiencia respiratoria crónica tipo II, en tratamiento con solución hipertónica, DNAsa, salbutamol, VNI nocturna y oxigenoterapia 24 horas, quien consulta por presentar desaturación y cefalea en el contexto de cambio de equipo de VNI. Se inicia tratamiento con HFNC y AVAPS presentando mejoría clínica, disminución de los requerimientos de oxígeno, descenso de la PaCO2 , disminución de los tapones mucosos en la tomografía y fluidificación de las secreciones respiratorias. Se plantea al HFNC como posible estrategia de tratamiento en los pacientes con FQ. Al prevenir el daño de la mucosa, disminuir la inflamación y las infecciones podría enlentecer el deterioro de la función pulmonar.


We present the case of a patient with cystic fibrosis and type II chronic respiratory failure under treatment with hypertonic solution, DNAse, salbutamol, night NIV and 24-hour oxygen therapy. The patient consults for desaturation and cephalea in the context of changing NIV equipment. The patient begins treatment with HHHF and AVAPS and shows clinical improvement, decrease in oxygen requirements, decrease in PaCO2 , less mucous plugging on the tomography and fluidifying of respiratory secretions. The HHHF is proposed as possible treatment strategy for patients with CF. By preventing damage to the mucosa and reducing inflammation and infections it could slow down impairment of the lung function.


Assuntos
Humanos , Fibrose Cística , Oxigênio , Oxigenoterapia , Insuficiência Respiratória
18.
Pediatr Infect Dis J ; 39(10): e297-e302, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32932329

RESUMO

BACKGROUND: Coronavirus disease 2019 (COVID-19) primarily affects adults and spares children, whereas very little is known about neonates. We tried to define the clinical characteristics, risk factors, laboratory, and imagining results of neonates with community-acquired COVID-19. METHODS: This prospective multicentered cohort study included 24 neonatal intensive care units around Turkey, wherein outpatient neonates with COVID-19 were registered in an online national database. Full-term and premature neonates diagnosed with COVID-19 were included in the study, whether hospitalized or followed up as ambulatory patients. Neonates without severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) via reverse transcriptase-polymerase chain reaction testing or whose mothers had been diagnosed with COVID-19 during pregnancy were excluded. RESULTS: Thirty-seven symptomatic neonates were included. The most frequent findings were fever, hypoxemia, and cough (49%, 41%, 27%, respectively). Oxygen administration (41%) and noninvasive ventilation (16%) were frequently required; however, mechanical ventilation (3%) was rarely needed. Median hospitalization was 11 days (1-35 days). One patient with Down syndrome and congenital cardiovascular disorders died in the study period. C-reactive protein (CRP) and prothrombin time (PT) levels were found to be higher in patients who needed supplemental oxygen (0.9 [0.1-8.6] vs. 5.8 [0.3-69.2] p = 0.002, 11.9 [10.1-17.2] vs. 15.2 [11.7-18.0] p = 0.01, respectively) or who were severe/critical (1.0 [0.01-8.6] vs. 4.5 [0.1-69.2] p = 0.01, 11.7 [10.1-13.9] vs. 15.0 [11.7-18.0] p = 0.001, respectively). CONCLUSIONS: Symptomatic neonates with COVID-19 had high rates of respiratory support requirements. High CRP levels or a greater PT should alert the physician to more severe disease.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/patologia , Pneumonia Viral/epidemiologia , Pneumonia Viral/patologia , Betacoronavirus , Proteína C-Reativa/metabolismo , Infecções Comunitárias Adquiridas , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/terapia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Recém-Nascido , Masculino , Oxigênio/administração & dosagem , Pandemias , Pneumonia Viral/fisiopatologia , Pneumonia Viral/terapia , Estudos Prospectivos , Tempo de Protrombina , Fatores de Risco , Turquia/epidemiologia
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