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1.
Environ Monit Assess ; 192(11): 675, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33025222

RESUMO

The largest uranium-phosphate deposit in Brazil also contains considerable levels of rare earth elements (REEs), which allows for the co-mining of these three ores. The most common methods for REE determination are time-consuming and demand complex sample preparation and use of hazardous reagents. Thus, the development of a safer and faster method to predict REEs in soil could aid in the assessment of these elements. We investigated the efficiency of near-infrared (NIR) spectroscopy to predict REEs in the soil of the uranium-phosphate deposit of Itataia, Brazil. We collected 50 composite topsoil samples in a well-distributed sampling grid along the deposit. The NIR measures in the soils ranged from 750 to 2500 nm. Three partial least squares regressions (PLSR) were selected to calibrate the spectra: full-spectrum partial least squares (PLS), interval partial least squares (iPLS), and successive projections algorithms for interval selection in partial least squares (iSPA-PLS). The concentrations of REEs were measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). In addition to raw spectral data, we also used spectral pretreatments to investigate the effects on prediction results: multiplicative scatter correction (MSC), Savitzky-Golay derivatives (SG), and standard normal variate transformation (SNV). Positive results were obtained in PLS for La and ΣLREE using MSC pretreatment and in iSPA-PLS for Nd and Ce using raw data. The accuracy of the measurements was related to the REE concentration in soil; i.e., elements with higher concentrations tended to present more accurate results. The results obtained here aim to contribute to the development of NIR spectroscopy techniques as a tool for mapping the concentrations of REEs in topsoil.


Assuntos
Urânio , Brasil , Monitoramento Ambiental , Análise dos Mínimos Quadrados , Fosfatos , Solo , Espectroscopia de Luz Próxima ao Infravermelho
2.
Anal Chem ; 92(19): 13396-13404, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-32867467

RESUMO

Rapid, accurate, reliable, and risk-free tracking of pathogenic microorganisms at the single-cell level is critical to achieve efficient source control and prevent outbreaks of microbial infectious diseases. For the first time, we report a promising approach for integrating the concepts of a remarkably large Stokes shift and dual-recognition into a single matrix to develop a pathogenic microorganism stimuli-responsive ratiometric fluorescent nanoprobe with speed, cost efficiency, stability, ultrahigh specificity, and sensitivity. As a proof-of-concept, we selected the Gram-positive bacterium Staphylococcus aureus (S. aureus) as the target analyte model, which easily bound to its recognition aptamer and the broad-spectrum glycopeptide antibiotic vancomycin (Van). To improve the specificity and short sample-to-answer time, we employed classic noncovalent π-π stacking interactions as a driving force to trigger the binding of Van and aptamer dual-functionalized near-infrared (NIR) fluorescent Apt-Van-QDs to the surface of an unreported blue fluorescent π-rich electronic carbon nanoparticles (CNPs), achieving S. aureus stimuli-responsive ratiometric nanoprobe Apt-Van-QDs@CNPs. In the assembly of Apt-Van-QDs@CNPs, the blue CNPs (energy donor) and NIR Apt-Van-QDs (energy acceptor) became close to allow the fluorescence resonance energy transfer (FRET) process, leading to a remarkable blue fluorescence quenching for the CNPs at ∼465 nm and a clear NIR fluorescence enhancement for Apt-Van-QDs at ∼725 nm. In the presence of S. aureus, the FRET process from CNPs to Apt-Van-QDs was disrupted, causing the nanoprobe Apt-Van-QDs@CNPs to display a ratiometric fluorescent response to S. aureus, which exhibited a large Stokes shift of ∼260 nm and rapid sample-to-answer detection time (∼30.0 min). As expected, the nanoprobe Apt-Van-QDs@CNPs showed an ultrahigh specificity for ratiometric fluorescence detection of S. aureus with a good detection limit of 1.0 CFU/mL, allowing the assay at single-cell level. Moreover, we also carried out the precise analysis of S. aureus in actual samples with acceptable results. We believe that this work offers new insight into the rational design of efficient ratiometric nanoprobes for rapid on-site accurate screening of pathogenic microorganisms at the single-cell level in the early stages, especially during the worldwide spread of COVID-19 today.


Assuntos
Bactérias/química , Infecções Bacterianas/diagnóstico , Infecções Bacterianas/microbiologia , Técnicas Biossensoriais/métodos , Corantes Fluorescentes/síntese química , Nanotecnologia/métodos , Antibacterianos/farmacologia , Aptâmeros de Nucleotídeos , Infecções por Coronavirus/complicações , Infecções por Coronavirus/microbiologia , Fluorescência , Transferência Ressonante de Energia de Fluorescência , Microbiologia de Alimentos/métodos , Humanos , Nanopartículas , Pandemias , Pneumonia Viral/complicações , Pneumonia Viral/microbiologia , Sensibilidade e Especificidade , Espectroscopia de Luz Próxima ao Infravermelho , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/química , Vancomicina/farmacologia
3.
PLoS One ; 15(8): e0234979, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32857778

RESUMO

The present meta-analysis was based on the available studies to determine the potential role of the initial and regional cerebral oxygen saturation (rSO2) in monitoring the efficiency of cardiopulmonary resuscitation (CPR) and predicting the return of spontaneous circulation (ROSC). Three electronic databases of PubMed, Embase, and the Cochrane Library were searched to identify the studies that investigated the role of rSO2 on ROSC in CA patients throughout May 2018. The weighted mean difference (WMD) with 95% confidence interval (CI) was calculated to estimate the pooled effect using a random-effects model. Sensitivity, subgroup analyses, and publication bias were conducted. A total of 13 studies involving 678 CA patients (300 in-hospital (IH) patients, and 378 out-hospital (OH) patients) were included. The summary WMD suggested that ROSC patients were associated with higher initial rSO2 (WMD: 10.10%; 95% CI: 5.66-14.55; P<0.001) and mean rSO2 (WMD: 14.16%; 95% CI: 10.51-17.81; P<0.001) levels during CA and ROSC as compared to the non-ROSC. The results of meta-regression suggested that the male percentage and the location of cardiac arrest might bias the initial or mean rSO2 and the incidence of ROSC. These significant differences were observed in nearly all subsets. The findings of this study suggested that high initial or mean rSO2 levels were both associated with an increased incidence of ROSC in CA patients undergoing CPR. These correlations might be affected by the percentage of males or the location of cardiac arrest, thereby necessitating further large-scale studies to substantiate whether these correlations differ according to gender and the location of cardiac arrest.


Assuntos
Circulação Sanguínea/fisiologia , Parada Cardíaca/fisiopatologia , Oximetria/métodos , Idoso , Idoso de 80 Anos ou mais , Reanimação Cardiopulmonar , Circulação Cerebrovascular/fisiologia , Feminino , Parada Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Parada Cardíaca Extra-Hospitalar/fisiopatologia , Parada Cardíaca Extra-Hospitalar/terapia , Avaliação de Resultados em Cuidados de Saúde , Oxigênio/sangue , Prognóstico , Espectroscopia de Luz Próxima ao Infravermelho/métodos
4.
PLoS One ; 15(8): e0236720, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32776946

RESUMO

Hemoglobin (Hb) is associated with cerebral oxygenation status owing to its important role of carrying oxygen to systemic tissues. However, data concerning the associations between Hb levels and cerebral regional oxygen saturation (rSO2) of hemodialysis (HD) patients is limited. We aimed to identify these associations to consider a target Hb level for renal anemia management. This study included 375 HD patients. Cerebral rSO2 before HD was monitored using the INVOS 5100c oxygen saturation monitor. Multivariable linear regression analysis showed that cerebral rSO2 was independently associated with natural logarithm (Ln)-HD duration (standardized coefficient: -0.36), mean blood pressure (standardized coefficient: 0.13), pH (standardized coefficient: -0.10), serum albumin (standardized coefficient: 0.14), presence of diabetes mellitus (standardized coefficient: -0.20), and Hb level (standardized coefficient: 0.29). Furthermore, a generalized linear model with restricted cubic spline function was used to investigate the non-linear association between cerebral rSO2 and Hb levels. In the multivariable analysis for the adjustment with Ln-HD duration, mean blood pressure, pH, serum albumin, and presence of diabetes mellitus, a linear relationship was demonstrated between the two variables (p for linearity = 0.79). Hb levels revealed the positive and significant association with cerebral rSO2 in this study. Moreover, the relationship between cerebral rSO2 and Hb level was proven to be linear. Therefore, the target Hb level in renal anemia management would be considered to be the upper limits for the appropriate management of renal anemia by previous guidelines and position statement from the viewpoint of maintaining cerebral oxygenation in HD patients.


Assuntos
Encéfalo/metabolismo , Hemoglobinas/metabolismo , Oxigênio/metabolismo , Diálise Renal , Espectroscopia de Luz Próxima ao Infravermelho , Idoso , Feminino , Humanos , Falência Renal Crônica/metabolismo , Falência Renal Crônica/terapia , Masculino
5.
PLoS One ; 15(8): e0237115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785247

RESUMO

In this study the near-infrared reflectance (NIR) spectra signals (750-2,500 nm) of soil samples was compared with the NIR signals of the biogenic aggregates produced in the lab by three earthworm species, i.e., Aporrectodea rosea (Savigny 1826), Lumbricus friendi Cognetti, 1904 and Prosellodrilus pyrenaicus (Cognetti, 1904) from subalpine meadows in the Central Pyrenees. NIR spectral signatures of biogenic aggregates, root-aggregates, and non-aggregated soil were obtained together with soil carbon (C), nitrogen (N), [Formula: see text] and [Formula: see text] determinations. The concentrations of C, N and C:N ratio in the three types of soil aggregates identified were not statistically significant (ANOVA, p>0.05) although non-macroaggregated soil had slightly higher C concentrations (66.3 g kg-1 dry soil) than biogenic aggregates (earthworm- and root-aggregates, 64.9 and 63.5 g kg-1 dry soil, respectively), while concentrations of [Formula: see text] and [Formula: see text] were highest in the root-attached aggregates (3.3 and 0.31 mg kg dry soil-1). Total earthworm density and biomass in the sampled area was 137.6 ind. m-2, and 55.2 g fresh weight m-2, respectively. The biomass of aggregates attached to roots and non-macroaggregated soil was 122.3 and 134.8 g m-2, respectively, while biomass of free (particulate) organic matter and invertebrate biogenic aggregates was 62.9 and 41.7 g m-2, respectively. Multivariate analysis of NIR spectra signals of field aggregates separated root aggregates with high concentrations of [Formula: see text] and [Formula: see text] (41.5% of explained variance, axis I) from those biogenic aggregates, including root aggregates, with large concentrations of C and high C:N ratio (21.6% of total variability, axis II). Partial Least Square (PLS) regressions were used to compare NIR spectral signals of samples (casts and soil) and develop calibration equations relating these spectral data to those data obtained for chemical variables in the lab. After a derivatization process, the NIR spectra of field aggregates were projected onto the PLS factorial plane of the NIR spectra from the lab incubation. The projection of the NIR spectral signals onto the PLSR models for C, N, [Formula: see text] and [Formula: see text] from casts produced and incubated in the lab allowed us to identify the species and the age of the field biogenic aggregates. Our hypothesis was to test whether field aggregates would match or be in the vicinity of the NIR signals that corresponded to a certain species and the age of the depositions produced in the lab. A NIRS biogenic background noise (BBN) is present in the soil as a result of earthworm activity. This study provides insights on how to analyse the role of these organisms in important ecological processes of soil macro-aggregation and associated organic matter dynamics by means of analyzing the BBN in the soil matrix.


Assuntos
Pradaria , Oligoquetos/fisiologia , Solo/química , Altitude , Amônia/análise , Animais , Carbono/análise , Nitrogênio/análise , Solo/parasitologia , Espectroscopia de Luz Próxima ao Infravermelho
6.
Pediatrics ; 146(3)2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32848028

RESUMO

BACKGROUND AND OBJECTIVES: Preterm infants with necrotizing enterocolitis (NEC) are known to have worse neurodevelopmental outcomes, but there is no substantial evidence to support an underlying pathophysiology. We aimed to examine whether cerebral oxygenation differs in those infants who develop NEC compared to cerebral oxygenation in those who do not. METHODS: We examined 48 infants <30 weeks' gestation admitted to a tertiary level NICU from October 2016 to May 2018. Infants with birth weight less than or equal to the second percentile, abnormal antenatal dopplers or twin-to-twin-transfusion-syndrome were excluded. Cerebral oximetry measurements were performed by using a near-infrared spectroscopy (NIRS) monitor weekly for 60 minutes, allowing measurement of cerebral tissue oxygenation index from the first week of life to 36 weeks postconceptional age. Weekly clinical status was also recorded. NEC was defined as greater than or equal to Bell stage 2. RESULTS: The median birth weight was 884 g (range of 460-1600 g), the median weeks' gestational age was 26 + 3/7 (23 + 0/7 to 29 + 6/7), and 52% were girls. In total, 276 NIRS measurements were completed, and 7 infants developed NEC. NIRS measurements from 1 infant with NEC and 4 infants without NEC who developed hemorrhagic parenchymal infarcts were excluded from analysis. Infants who developed NEC had significantly lower cerebral tissue oxygenation index than those who did not (P = .011), even when adjusted for confounders, including gestational age, birth weight, patent ductus arteriosus, enteral feeds, sex, ethnicity, and hemoglobin. CONCLUSIONS: Infants with NEC have significantly lower cerebral tissue oxygenation throughout their neonatal intensive care stay in comparison with those who did not develop NEC. This is a novel finding and could explain their worse neurodevelopmental outcome.


Assuntos
Encéfalo/metabolismo , Enterocolite Necrosante/metabolismo , Consumo de Oxigênio/fisiologia , Antibioticoprofilaxia , Permeabilidade do Canal Arterial/diagnóstico por imagem , Enterocolite Necrosante/etiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Oximetria/instrumentação , Oximetria/métodos , Estudos Prospectivos , Espectroscopia de Luz Próxima ao Infravermelho , Fatores de Tempo
7.
Anticancer Res ; 40(7): 3873-3882, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32620627

RESUMO

BACKGROUND/AIM: This study investigated the use of near-infrared fluorescent imaging for securing safe margins during liver resection. PATIENTS AND METHODS: This study included 125 patients who underwent liver tumor resection in 2014-2018. Indocyanine green testing was performed 2-14 days before surgery. Histopathological specimens of hepatocellular carcinoma (HCC) and colorectal liver metastasis (CRLM) were evaluated using fluorescent microscopy. RESULTS: Fluorescence microscopy identified signals in 26/53 (49.0%) and 36/72 (50%) cases of HCC and CRLM, respectively. HCC demonstrated total, partial, rim, and combined fluorescence patterns; CRLM uniformly demonstrated rim fluorescence. Although rim fluorescence was seen in both HCC and CRLM, no malignancy was confirmed pathologically in the peritumoral area demonstrating fluorescence. The median widths of fluorescence from the tumor edge in HCC and CRLM were 1227.5 µm and 1608 µm, respectively, with no significant difference. CONCLUSION: Near-infrared fluorescent imaging can reliably detect safe surgical margins intraoperatively during liver resection.


Assuntos
Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/diagnóstico por imagem , Feminino , Hepatectomia/métodos , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Masculino , Margens de Excisão , Microscopia de Fluorescência , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Estudos Retrospectivos , Espectroscopia de Luz Próxima ao Infravermelho/métodos
8.
Food Chem ; 332: 127419, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32622190

RESUMO

Aflatoxins (AFs) are potent carcinogens present in numerous crops. Access to accurate methods for evaluating contamination is a critical factor in aflatoxin risk assessment. Versicolorin A (Ver A), a precursor of aflatoxin B1 (AFB1), can be used as an indicator for the presence of AFB1, even when the AF is not yet detectable. Currently employed Ver A detection methods are expensive, time consuming, and difficult to apply to numerous samples. Herein, Ver A was detected via near-infrared spectroscopy. Both quantitative and two-grade sorting methods were set-up using the extreme gradient boosting algorithm coupled with a support vector machine. This two-tiered method obtained a root-mean-square error of prediction value of 3.57 µg/kg for the quantitative model, and an accuracy rate of 90.32% for the sorting approach. This novel method is rapid, accurate, solvent free, requires no sample pretreatment, and detects Ver A in maize, making it convenient for practical use.


Assuntos
Aflatoxina B1/análise , Antraquinonas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Zea mays/química , Contaminação de Alimentos/análise , Humanos
9.
Surg Clin North Am ; 100(4): 807-822, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32681878

RESUMO

Peripheral arterial disease (PAD) affects many individuals worldwide and is associated with increased morbidity and mortality. Controversy exists on whether or not to screen asymptomatic patients. Further complicating this is that many patients with a chronic lower extremity wound are often asymptomatic. PAD and traditional noninvasive vascular studies may be inaccurate in providing a correct diagnosis. A review of current and novel vascular assessment modalities along with their benefits and limitations are presented here. A combination of these vascular assessments may help improve accuracy in diagnosis, providing timely care to those patients in need.


Assuntos
Perna (Membro)/irrigação sanguínea , Doença Arterial Periférica/fisiopatologia , Índice Tornozelo-Braço , Monitorização Transcutânea dos Gases Sanguíneos/métodos , Pressão Sanguínea/fisiologia , Determinação da Pressão Arterial/métodos , Humanos , Pele/irrigação sanguínea , Dermatopatias Vasculares/fisiopatologia , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Sístole/fisiologia , Cicatrização/fisiologia
10.
Nat Commun ; 11(1): 3440, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651387

RESUMO

In recent years, exploration of the brain extracellular space (ECS) has made remarkable progress, including nanoscopic characterizations. However, whether ECS precise conformation is altered during brain pathology remains unknown. Here we study the nanoscale organization of pathological ECS in adult mice under degenerative conditions. Using electron microscopy in cryofixed tissue and single nanotube tracking in live brain slices combined with super-resolution imaging analysis, we find enlarged ECS dimensions and increased nanoscale diffusion after α-synuclein-induced neurodegeneration. These animals display a degraded hyaluronan matrix in areas close to reactive microglia. Furthermore, experimental hyaluronan depletion in vivo reduces dopaminergic cell loss and α-synuclein load, induces microgliosis and increases ECS diffusivity, highlighting hyaluronan as diffusional barrier and local tissue organizer. These findings demonstrate the interplay of ECS, extracellular matrix and glia in pathology, unraveling ECS features relevant for the α-synuclein propagation hypothesis and suggesting matrix manipulation as a disease-modifying strategy.


Assuntos
Encéfalo/metabolismo , Espaço Extracelular/metabolismo , Ácido Hialurônico/metabolismo , Sinucleinopatias/metabolismo , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microglia/metabolismo , Microglia/ultraestrutura , Microscopia Eletrônica , Doença de Parkinson/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho
11.
Food Chem ; 333: 127449, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32659663

RESUMO

The demand for the development of fast, easy-to-use and low-cost analytical methods for food adulteration analysis has being increasing in the last years. Although infrared spectroscopic techniques offer these advantages, the validation of screening methods requiring the application of multivariate data treatment is less frequently described in literature thus limiting their use as routine tools in control laboratories for food fraud monitoring. In this paper, an EU-validation procedure for screening methods was successfully applied to a multivariate FT-NIR spectroscopic method for the screening of durum wheat pasta samples adulterated with common wheat at the screening target concentration of 3%. Good results in terms of the cut-off value (2.32% mass fraction of soft wheat) and false suspect rates (0.1% for blanks; 13% at 1% mass fraction) demonstrated that the present validation approach would be a proof-of-strategy to be used for multivariate infrared methods applied for screening purposes.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Triticum/química , Farinha/análise , Análise de Alimentos/estatística & dados numéricos , Análise dos Mínimos Quadrados , Análise Multivariada , Espectroscopia de Luz Próxima ao Infravermelho/estatística & dados numéricos
12.
Food Chem ; 331: 127332, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32593040

RESUMO

The utility of an autoencoder (AE) as a feature extraction tool for near-infrared (NIR) spectroscopy-based discrimination analysis has been explored and the discrimination of the geographic origins of 8 different agricultural products has been performed as the case study. The sample spectral features were broad and insufficient for component distinction due to considerable overlap of individual bands, so AE enabling of extracting the sample-descriptive features in the spectra would help to improve discrimination accuracy. For comparison, four different inputs of AE-extracted features, raw NIR spectra, principal component (PC) scores, and features extracted using locally linear embedding were employed for sample discrimination using support vector machine. The use of AE-extracted feature improved the accuracy in the discrimination of samples in all 8 products. The improvement was more substantial when the sample spectral features were indistinct. It demonstrates that AE is expandable for vibrational spectroscopic discriminant analysis of other samples with complex composition.


Assuntos
Informática/métodos , Espectroscopia de Luz Próxima ao Infravermelho , Análise Discriminante , Análise de Componente Principal , Máquina de Vetores de Suporte
13.
Vasa ; 49(5): 367-374, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32513067

RESUMO

Background: Patients undergoing carotid endarterectomy (CEA) may suffer from cerebral hypoperfusion during the carotid cross-clamping. Near-infrared spectroscopy cerebral oximetry (NIRS) is a non-invasive method of regional cerebral oxygen saturation measurement reflecting changes in cerebral blood flow during CEA. The main goal of the study was to evaluate the accuracy of the NIRS in detecting cerebral hypoperfusion during CEA under regional anesthesia (RA) and compare it with awake neurological testing. Patients and methods: A prospective observational study of 28 patients that underwent CEA in RA and manifested neurologic deficits, and 28 consecutive controls from a tertiary and referral center, was performed. All patients were monitored with NIRS cerebral oximetry and awake testing as the control technique. Subsequently, operating characteristic curve and Cohen's kappa coefficient were determined to evaluate the reliability of the monitoring test. Results: NIRS presented a sensitivity of 27.3% and a specificity of 89.3% in comparison to awake testing. Receiver operating characteristic (ROC) curve analysis demonstrated that a decrease of at least 20% in cerebral oxygen saturation is the best threshold to infer cerebral hypoperfusion. However, the respective area under the curve (AUROC) was 0.606 (95% CI: 0.456-0.756, P = 0.178) with a calculated Cohen's kappa of 0.179, P = 0.093. Regarding 30-days outcomes, only awake testing has shown significant associations with stroke and postoperative complications (P = 0.043 and P = 0.05), which were higher in patients with post-clamping neurologic deficits. Conclusions: NIRS demonstrated a reduced discriminative capacity for critical cerebral hypoperfusion, and does not seem to add substantial clinical benefits to the awake test.


Assuntos
Anestesia por Condução , Endarterectomia das Carótidas , Isquemia Encefálica , Circulação Cerebrovascular , Humanos , Monitorização Intraoperatória , Oximetria , Oxigênio , Estudos Prospectivos , Reprodutibilidade dos Testes , Espectroscopia de Luz Próxima ao Infravermelho
14.
Zhongguo Zhong Yao Za Zhi ; 45(9): 2115-2121, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32495560

RESUMO

A rapid analysis method based on ultraviolet-visual(UV-Vis) spectroscopy, near infrared(NIR) spectroscopy and multivariable data analysis was established for quality evaluation of Shengxuebao Mixture. The contents of eight active ingredients of Shengxuebao Mixture including albiflorin, paeoniflorin, 2, 3, 5, 4'-tetra-hydroxy-stilbene-2-O-ß-D-glucopyranoside, specnuezhenide,ecliptasaponin D, emodin, calycosin-7-glucoside and astragaloside Ⅳ were simultaneously detected by using this method. HPLC-UV-MS was used as a reference method for determining the contents of these ingredients. Partial least squares(PLS) analysis was implemented as a linear method for multivariate models calibrated between UV spectrum/NIR spectrum and contents of 8 ingredients. Finally, the performance of the model was evaluated by 24 batches of test samples. The results showed that both UV-Vis and NIR models gave a good calibration ability with an R~2 value above 0.9, and the prediction ability was also satisfactory, with an R~2 value higher than 0.83 for UV-Vis model and higher than 0.79 for NIR model. The overall results demonstrate that the established method is accurate, robust and fast, therefore, it can be used for rapid quality evaluation of Shengxuebao Mixture.


Assuntos
Medicamentos de Ervas Chinesas , Espectroscopia de Luz Próxima ao Infravermelho , Calibragem , Cromatografia Líquida de Alta Pressão , Análise dos Mínimos Quadrados , Espectrometria de Massas
15.
Food Chem ; 331: 127359, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32580128

RESUMO

Cyanide is a highly toxic anion. Nonetheless, many food plants could produce endogenous cyanide, which causes great danger to human health. Thus, monitoring cyanide in food samples is critically significant. Herein, we rationally developed the first ratiometric near-infrared fluorescent probe for sensing cyanide in food samples. The probe displayed noticeable fluorescence in near-infrared region. Moreover, upon treatment with cyanide, the probe exhibited highly selective and sensitive ratiometric fluorescence response, with limit of detection determined to be 0.075 µM and limit of quantification determined to be 0.25 µM. The ratios of fluorescent intensities at 519 and 688 nm (I519/I688) was linear with added cyanide concentrations from 0 to 80 µM. The relative standard deviations for repeatability and reproducibility varied from 0.55 to 8.94 and from 1.17 to 9.46, respectively. Significantly, probe Hy has been successfully applied for monitoring cyanide in various food samples, such as almonds, sprouting potatoes, and bamboo shoots.


Assuntos
Cianetos/análise , Corantes Fluorescentes/química , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Limite de Detecção , Prunus dulcis/química , Reprodutibilidade dos Testes , Sasa/química , Sensibilidade e Especificidade , Solanum tuberosum/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos
16.
J Vis Exp ; (159)2020 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-32510492

RESUMO

Concurrent EEG and fNIRS recordings offer an excellent opportunity to gain a full understanding of the neural mechanism of cognitive processing by inspecting the relationship between the neural and hemodynamic signals. EEG is an electrophysiological technology that can measure the rapid neuronal activity of the cortex, whereas fNIRS relies on the hemodynamic responses to infer brain activation. The combination of EEG and fNIRS neuroimaging techniques can identify more features and reveal more information associated with the functioning of the brain. In this protocol, fused EEG-fNIRS measurements were performed for concurrent recordings of evoked-electrical potentials and hemodynamic responses during a Flanker task. In addition, the critical steps for setting up the hardware and software system as well as the procedures for data acquisition and analysis were provided and discussed in detail. It is expected that the present protocol can pave a new avenue for improving the understanding of the neural mechanisms underlying various cognitive processes by using the EEG and fNIRS signals.


Assuntos
Encéfalo/fisiologia , Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados , Hemodinâmica , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Humanos
17.
PLoS One ; 15(6): e0234557, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32555660

RESUMO

After mating, female mosquitoes need animal blood to develop their eggs. In the process of acquiring blood, they may acquire pathogens, which may cause different diseases in humans such as malaria, zika, dengue, and chikungunya. Therefore, knowing the parity status of mosquitoes is useful in control and evaluation of infectious diseases transmitted by mosquitoes, where parous mosquitoes are assumed to be potentially infectious. Ovary dissections, which are currently used to determine the parity status of mosquitoes, are very tedious and limited to few experts. An alternative to ovary dissections is near-infrared spectroscopy (NIRS), which can estimate the age in days and the infectious state of laboratory and semi-field reared mosquitoes with accuracies between 80 and 99%. No study has tested the accuracy of NIRS for estimating the parity status of wild mosquitoes. In this study, we train an artificial neural network (ANN) models on NIR spectra to estimate the parity status of wild mosquitoes. We use four different datasets: An. arabiensis collected from Minepa, Tanzania (Minepa-ARA); An. gambiae s.s collected from Muleba, Tanzania (Muleba-GA); An. gambiae s.s collected from Burkina Faso (Burkina-GA); and An.gambiae s.s from Muleba and Burkina Faso combined (Muleba-Burkina-GA). We train ANN models on datasets with spectra preprocessed according to previous protocols. We then use autoencoders to reduce the spectra feature dimensions from 1851 to 10 and re-train the ANN models. Before the autoencoder was applied, ANN models estimated parity status of mosquitoes in Minepa-ARA, Muleba-GA, Burkina-GA and Muleba-Burkina-GA with out-of-sample accuracies of 81.9±2.8 (N = 274), 68.7±4.8 (N = 43), 80.3±2.0 (N = 48), and 75.7±2.5 (N = 91), respectively. With the autoencoder, ANN models tested on out-of-sample data achieved 97.1±2.2% (N = 274), 89.8 ± 1.7% (N = 43), 93.3±1.2% (N = 48), and 92.7±1.8% (N = 91) accuracies for Minepa-ARA, Muleba-GA, Burkina-GA, and Muleba-Burkina-GA, respectively. These results show that a combination of an autoencoder and an ANN trained on NIR spectra to estimate the parity status of wild mosquitoes yields models that can be used as an alternative tool to estimate parity status of wild mosquitoes, especially since NIRS is a high-throughput, reagent-free, and simple-to-use technique compared to ovary dissections.


Assuntos
Anopheles/fisiologia , Malária/transmissão , Mosquitos Vetores/fisiologia , Redes Neurais de Computação , Oviparidade , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Animais , Feminino , Humanos
18.
Fa Yi Xue Za Zhi ; 36(1): 52-60, 2020 Feb.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-32250079

RESUMO

Abstract: Objective To discuss the activation characteristics of the prefrontal cortex of people with mild cognitive impairment (MCI) due to brain trauma during working memory tasks. Methods The psychological experiment design software E-prime was used and N-back paradigm was adopted as working memory task. Functional near-infrared spectroscopy (fNIRS) was used to detect changes in cortical oxygenated hemoglobin concentrations of 22 channels within the prefrontal lobe of 24 people with MCI due to brain trauma (study group) and 27 healthy volunteers (control group) with matching gender and age. Behavioral data, such as the number of keystroke errors and reaction time, were recorded simultaneously. Independent samples t test and non-parametric test were used to compare the mean value of oxygenated hemoglobin concentration change, the number of key errors and the mean value of reaction time of the two groups in each task. Results (1) The differences in the number of errors and reaction time between the two groups in 1-back and 2-back tasks had statistical significance (P<0.05).The main effects of task load and group were both significant (task F=14.11, P=0.001 1; group F=10.39, P=0.001 5). (2) During the 1-back task, the differences in oxygenated hemoglobin concentration changes of the 22 channels between the two groups had no statistical significance (P>0.05). During the 2-back task, the differences in oxygenated hemoglobin concentration changes of the two groups in channel 2, 3, 7, 9, 10, 11, 14, 15, 18, 19, 21 and 22 had statistical significance (P<0.05). (3) In the 1-back task, the left frontal pole and dorsolateral prefrontal area in both groups were activated. In the 2-back task, the activation areas of the control group were the left frontal pole area and the left dorsolateral prefrontal area, while that of the study group almost covered most of the left and right frontal pole areas, which were scattered and the right area was activated, too. Conclusion Patients with MCI due to brain trauma have obvious working memory impairment, and during the 2-back working memory task, the activation of the prefrontal lobe decreased, but the activation range was wider.


Assuntos
Lesões Encefálicas Traumáticas , Disfunção Cognitiva , Lesões Encefálicas Traumáticas/complicações , Disfunção Cognitiva/etiologia , Humanos , Memória de Curto Prazo , Córtex Pré-Frontal , Espectroscopia de Luz Próxima ao Infravermelho
20.
Food Chem ; 321: 126695, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247889

RESUMO

Freezing, heating, and pickling are common processes for pork meats. Unsaturated fatty acids including monounsaturated fatty acids and polyunsaturated fatty acids are indispensable nutrition beneficial to human's health and growth. However, Unsaturated fatty acids are affected by processing methods. Hyperspectral imaging is a novel technique widely used for food quality and safety evaluation. In the current study, the contents of monounsaturated and polyunsaturated fatty acids were assessed by Hyperspectral imaging. Optimal wavelengths were selected by the regression coefficients curves of partial least squares regression models. The least-squares support vector machine models established achieved a better coefficient of determination in the Monte Carlo validation set than the partial least squares regression models developed and the R2MV values for the least squares - support vector machine models based on selected optimal wavelengths were higher than 0.81. Finally, colour maps of the contents of monounsaturated and polyunsaturated fatty acids were developed.


Assuntos
Ácidos Graxos Monoinsaturados/análise , Ácidos Graxos Insaturados/análise , Análise de Alimentos/métodos , Carne de Porco/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Análise de Alimentos/estatística & dados numéricos , Indústria de Processamento de Alimentos/métodos , Congelamento , Calefação , Análise dos Mínimos Quadrados , Espectroscopia de Luz Próxima ao Infravermelho/estatística & dados numéricos , Máquina de Vetores de Suporte
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