An innovative sensing assay is described for point-of-care (PoC) quantification of a biomarker of Alzheimer's disease, amyloid beta-42 (Abeta-42). This device is based on a cellulose paper-dye test ...strip platform in which the corresponding detection layer is integrated by applying a molecularly imprinted polymer (MIP) to the cellulose paper surface. Briefly, the cellulose paper is chemically modified with a silane to subsequently apply the MIP detection layer. The imprinting process is confirmed by the parallel preparation of a control material, namely a non-imprinted polymer (NIP). The chemical changes of the surface were evaluated by Fourier transform infrared spectroscopy (FTIR), contact angle, and thermogravimetric analysis (TG). Proteins and peptides can be quantified by conventional staining methods. For this purpose, Coomassie blue (CB) was used as a staining dye for the detection and quantification of Abeta-42. Quantitative determination is made possible by taking a photograph and applying an appropriate mathematical treatment to the color coordinates provided by the ImageJ program. The MIP shows a linear range between 1.0 ng/mL and 10 mug/mL and a detection limit of 0.71 ng/mL. Overall, this cellulose-based assay is suitable for the detection of peptides or proteins in a sample by visual comparison of color change. The test strip provides a simple, instrument-free, and cost-effective method with high chemical stability, capable of detecting very small amounts of peptides or proteins in a sample, and can be used for the detection of any (bio)molecule of interest. Graphical abstract
Constructing monodispersed metal sites in heterocatalysis is an efficient strategy to boost their catalytic performance. Herein, a new strategy using monodispersed metal sites to tailor Pt‐based ...nanocatalysts is addressed by engineering unconventional p–d orbital hybridization. Thus, monodispersed Ga on Pt3Mn nanocrystals (Ga‐O‐Pt3Mn) with high‐indexed facets was constructed for the first time to drive ethanol electrooxidation reaction (EOR). Strikingly, the Ga‐O‐Pt3Mn nanocatalyst shows an enhanced EOR performance with achieving 8.41 times of specific activity than that of Pt/C. The electrochemical in situ Fourier transform infrared spectroscopy results and theoretical calculations disclose that the Ga‐O‐Pt3Mn nanocatalyst featuring an unconventional p–d orbital hybridization not only promote the C−C bond‐breaking and rapid oxidation of ‐OH of ethanol, but also inhibit the generation of poisonous CO intermediate species. This work discloses a promising strategy to construct a novel nanocatalysts tailored by monodispersed metal site as efficient fuel cell catalysts.
The monodispersed Ga site tailored Pt3Mn nanocatalyst based on high‐indexed facets was constructed and shows excellent EOR performance with high activity and selectivity towards the C2 reaction pathway, which was attributed to the unconventional p–d orbital hybridization and atomic‐level interface synergy.
Near Infrared Spectroscopy (NIRS) analysis at the single seed level is a useful tool for breeders, farmers, feeding facilities, and food companies according to current researches. As a ...non-destructive technique, NIRS allows for the selection and classification of seeds according to specific traits and attributes without alteration of their properties. Critical aspects in using NIRS for single seed analysis such as reference method, sample morphology, and spectrometer suitability are discussed in this review. A summary of current applications of NIRS technologies at single seed level is also presented.
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•Most NIR single seed publications target wheat, soybean, and corn.•Comparison of published studies is difficult and some are not properly validated.•Sampling of seeds in movement leads to calibrations with better predictive abilities.•Spectra preprocessing improves the quantification of most seed attributes.
Driver cognitive distraction is a critical factor in road safety, and its evaluation, especially under real conditions, presents challenges to researchers and engineers. In this study, we considered ...mental workload from a secondary task as a potential source of cognitive distraction and aimed to estimate the increased cognitive load on the driver with a four-channel near-infrared spectroscopy (NIRS) device by introducing a machine-learning method for hemodynamic data. To produce added cognitive workload in a driver beyond just driving, two levels of an auditory presentation n-back task were used. A total of 60 experimental data sets from the NIRS device during two driving tasks were obtained and analyzed by machine-learning algorithms. We used two techniques to prevent overfitting of the classification models: (1)
-fold cross-validation and principal-component analysis, and (2) retaining 25% of the data (testing data) for testing of the model after classification. Six types of classifier were trained and tested: decision tree, discriminant analysis, logistic regression, the support vector machine, the nearest neighbor classifier, and the ensemble classifier. Cognitive workload levels were well classified from the NIRS data in the cases of subject-dependent classification (the accuracy of classification increased from 81.30 to 95.40%, and the accuracy of prediction of the testing data was 82.18 to 96.08%), subject 26 independent classification (the accuracy of classification increased from 84.90 to 89.50%, and the accuracy of prediction of the testing data increased from 84.08 to 89.91%), and channel-independent classification (classification 82.90%, prediction 82.74%). NIRS data in conjunction with an artificial intelligence method can therefore be used to classify mental workload as a source of potential cognitive distraction in real time under naturalistic conditions; this information may be utilized in driver assistance systems to prevent road accidents.
Near infrared spectroscopy (NIRS) is a high throughput technique that measures absorbance of specific wavelengths of light by biological samples and uses this information to classify the age of ...lab-reared mosquitoes as younger or older than seven days with an average accuracy greater than 80%. For NIRS to estimate ages of wild mosquitoes, a sample of wild mosquitoes with known age in days would be required to train and test the model. Mark-release-recapture is the most reliable method to produce wild-caught mosquitoes of known age in days. However, it is logistically demanding, time inefficient, subject to low recapture rates, and raises ethical issues due to the release of mosquitoes. Using labels from Detinova dissection results in a mathematical model with poor accuracy. Alternatively, a model trained on spectra from laboratory-reared mosquitoes where age in days is known can be applied to estimate the age of wild mosquitoes, but this would be appropriate only if spectra collected from laboratory-reared and wild mosquitoes are similar.
We performed k-means (k = 2) cluster analysis on a mixture of spectra collected from lab-reared and wild Anopheles arabiensis to determine if there is any significant difference between these two groups. While controlling the numbers of mosquitoes included in the model at each age, we found two clusters with no significant difference in distribution of spectra collected from lab-reared and wild mosquitoes (p = 0.25). We repeated the analysis using hierarchical clustering, and similarly, no significant difference was observed (p = 0.13).
We find no difference between spectra collected from laboratory-reared and wild mosquitoes of the same age and species. The results strengthen and support the on-going practice of applying the model trained on spectra collected from laboratory-reared mosquitoes, especially first-generation laboratory-reared mosquitoes.
Gravitational lensing sometimes dominates the observed properties of apparently very bright objects. We present morphological properties in the high-resolution (FWHM ∼ 0 15) Atacama Large ...Millimeter/submillimeter Array (ALMA) 1 mm map for an ultraluminous quasar at z = 6.30, SDSS J010013.02+280225.8 (hereafter J0100+2802), whose black hole (BH) mass MBH is the most massive (∼1.2 × 1010M ) at z > 6 ever known. We find that the continuum emission of J0100+2802 is resolved into a quadruple system within a radius of 0 2, which can be interpreted as either multiple dusty star-forming regions in the host galaxy or multiple images due to strong gravitational lensing. The Mg ii absorption and the potential Ly line features have been identified at z = 2.33 in the near-infrared spectroscopy toward J0100+2802, and a simple mass model fitting well reproduces the positions and flux densities of the quadruple system, both of which are consistent with the latter interpretation. Although a high-resolution map taken in the Advanced Camera for Survey on board Hubble Space Telescope (HST) shows a morphology with an apparently single component, in our fiducial lens mass model it can simply be explained by a ∼50 pc scale offset between the ALMA and HST emission regions. In this case, the magnification factor for the observed HST emission is obtained to ∼450, reducing the intrinsic MBH estimate to below 109 M . The confirmation or the rejection of the gravitational lensing scenario is important for our understanding of the supermassive BHs in the early universe.
Here, we present new cryogenic infrared spectra of the (Imidazole) Formula omitted (n=1,2,3) ions. The data was obtained using helium tagging infrared predissociation spectroscopy. The new results ...were compared with the data obtained by Gerardi et al. (Chem. Phys. Lett. 501:172-178, 2011 (See CR12)) using the same technique but with argon as a tag. Comparison of the two experiments, assisted by theoretical calculations, allowed us to evaluate the preferable attachment positions of argon to the (Imidazole) Formula omitted frame. Argon attaches to nitrogen-bonded hydrogen in the case of the (Imidazole)H Formula omitted ion, while in (Imidazole) Formula omitted and (Imidazole) Formula omitted the preferred docking sites for the argon are in the center of the complex. This conclusion is supported by analyzing the spectral features attributed to the N-H stretching vibrations. Symmetry adapted perturbation theory (SAPT) analysis of the non-covalent forces between argon and the (Imidazole) Formula omitted (n=1,2,3) frame revealed that this switch of docking preference with increasing complex size is caused by an interplay between induction and dispersion interactions.
Background
Measurement of regional pulmonary oxygen saturation by near‐infrared spectroscopy is a novel monitorization method. This study aimed to determine the early regional pulmonary oxygen ...saturations in neonates with respiratory distress.
Methods
This observational study was conducted at the delivery room in infants above 35 weeks of gestation who developed respiratory distress immediately after birth. Preductal oxygen saturation (Covidien Nellcor®) and regional oxygen saturations of both apical (raSO2) and basal regions (rbSO2) of right lung were measured (Covidien INVOS®) within the first 15 min of life and compared to those of healthy neonates.
Results
Of the 165 infants included to the study, 15 were late preterm and 55 developed respiratory distress. Infants with respiratory distress had significantly lower gestational age and birth weight. Regional pulmonary oxygenations at both apex and basal lung areas were positively correlated with SpO2 in all infants. The rbSO2 was significantly lower than raSO2 until 10th minute of life regardless of respiratory distress. The fractionized tissue oxygen extraction of both apical and basal lung areas was significantly higher in infants with respiratory distress until 5th minute of life.
Conclusion
This study is one of the pioneer studies evaluating the early pulmonary oxygenation values of infants with respiratory distress. Oxygenation of apical lung regions are better than basal areas. Higher fractionized tissue oxygen extraction showed the impaired pulmonary perfusion in infants with respiratory distress.
Although P(VDF-TrFE) is an important ferroelectric material, its polarization switching details, especially at the nucleation site of the polarized domain, are unknown. Herein, a setup combining a ...ferroelectricity evaluation system and a Fourier-transform infrared spectrometer with a 70 ms time resolution was developed to simultaneously monitor polarization-switching current and absorption changes associated with the molecular chain rotation of P(VDF-TrFE) under an electric field. Time variations of absorbance associated with CF2 symmetric vibration in response to the applied electric field served as an indicator of dipole rotation. The onsets and peaks of the polarization-switching current, which appeared before the dynamic molecular orientation, changed across the material. The complementary characterization revealed that the P(VDF-TrFE) polarized domain first nucleates at the interface and grows toward the inner side of film to achieve a completely polarized state of the film.
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•Molecular rotation of P(VDF-TrFE) associated with its polarization reversal was monitored by IR.•Drastic absorbance changes occur beyond coercive electric field of P(VDF-TrFE).•Polarized domain first nucleates at interface, then grows toward film interior.•As a result, a completely polarized state of film is achieved.
Neuroergonomics combines neuroscience with ergonomics to study human performance using recorded brain signals. Such neural signatures of performance can be measured using a variety of neuroimaging ...techniques, including functional magnetic resonance imaging (fMRI), functional near-infrared spectroscopy (fNIRS), and electroencephalography (EEG). EEG has an excellent temporal resolution, and EEG indices are highly sensitive to human brain activity fluctuations.
The focus of this systematic review was to explore the applications of EEG indices for quantifying human performance in a variety of cognitive tasks at the macro and micro scales. To identify trends and the state of the field, we examined global patterns among selected articles, such as journal contributions, highly cited papers, affiliations, and high-frequency keywords. Moreover, we discussed the most frequently used EEG indices and synthesized current knowledge regarding the EEG signatures of associated human performance measurements.
In this systematic review, we analyzed articles published in English (from peer-reviewed journals, proceedings, and conference papers), Ph.D. dissertations, textbooks, and reference books. All articles reviewed herein included exclusively EEG-based experimental studies in healthy participants. We searched Web-of-Science and Scopus databases using specific sets of keywords.
Out of 143 papers, a considerable number of cognitive studies focused on quantifying human performance with respect to mental fatigue, mental workload, mental effort, visual fatigue, emotion, and stress. An increasing trend for publication in this area was observed, with the highest number of publications in 2017. Most studies applied linear methods (e.g., EEG power spectral density and the amplitude of event-related potentials) to evaluate human cognitive performance. A few papers utilized nonlinear methods, such as fractal dimension, largest Lyapunov exponent, and signal entropy. More than 50% of the studies focused on evaluating an individual's mental states while operating a vehicle. Several different methods of artifact removal have also been noted. Based on the reviewed articles, research gaps, trends, and potential directions for future research were explored.
This systematic review synthesized current knowledge regarding the application of EEG indices for quantifying human performance in a wide variety of cognitive tasks. This knowledge is useful for understanding the global patterns of applications of EEG indices for the analysis and design of cognitive tasks.
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