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Purpose: We examined the effects of increasing hypoxia severity on oxygenation kinetics in the vastus lateralis muscle during repeated treadmill sprints, using statistical parametric mapping (SPM). Methods: Ten physically active males completed 8 sprints of 5 seconds each (recovery = 25 s) on a motorized sprint treadmill in normoxia (sea level; inspired oxygen fraction = 0.21), moderate hypoxia (inspired oxygen fraction = 0.17), and severe hypoxia (SH; inspired oxygen fraction = 0.13). Continuous assessment of tissue saturation index (TSI) in the vastus lateralis muscle was conducted using near-infrared spectroscopy. Subsequently, TSI data were averaged for the sprint–recovery cycle of all sprints and compared between conditions. Results: The SPM analysis revealed no discernible difference in TSI signal amplitude between conditions during the actual 5-second sprint phase. However, during the latter portion of the 25-second recovery phase, TSI values were lower in SH compared with both sea level (from 22 to 30 s; P =.003) and moderate hypoxia (from 16 to 30 s; P =.001). The mean distance covered at sea level (22.9 [1.0] m) was greater than for both moderate hypoxia (22.5 [1.2] m; P =.045) and SH (22.3 [1.4] m; P =.043). Conclusions: The application of SPM demonstrated that only SH reduced muscle oxygenation levels during the late portion of the passive (recovery) phase and not the active (sprint) phase during repeated treadmill sprints. These findings underscore the usefulness of SPM for assessing muscle oxygenation differences due to hypoxic exposure and the importance of the duration of the between-sprints recovery period. [ABSTRACT FROM AUTHOR]

Purpose: An inspiratory muscle warm-up (IMW) improves inspiratory muscle function, but the effects of high-intensity exercise are inconsistent. We aimed to determine the effects of high-intensity IMW on high-intensity exercise performance and muscle oxygenation. Methods: Ten healthy men (maximal oxygen uptake [ V ˙ O 2 max ] 52.2 [5.0] mL·kg–1·min–1) performed constant-load exercise to exhaustion on a cycle ergometer at V ˙ O 2 max under 2 IMW conditions: a placebo condition (PLA) and a high-intensity IMW condition (HIGH). The inspiratory loads were set at 15% and 80% of maximal inspiratory pressure, respectively. Maximal inspiratory pressure was measured before and after IMW. Oxyhemoglobin was measured in the vastus lateralis by near-infrared spectroscopy during exercise. Rating of perceived exertion (RPE) for a leg was measured after 1 and 2 minutes of exercise. Results: Exercise tolerance was significantly higher under HIGH than PLA (228 [49] s vs 218 [49] s, P =.003). Maximal inspiratory pressure was significantly increased by IMW under HIGH (from 125 [20] to 136 [25] cm H2O, P =.031). Oxyhemoglobin was significantly higher under HIGH than PLA at 80% of the total duration of exercise (P =.048). RPE for the leg was significantly lower under HIGH than PLA after 2 minutes of exercise (P =.019). Conclusions: Given that oxyhemoglobin is an index of local oxygen supply, the results of this study suggest that high-intensity IMW increases the oxygen supply to active limbs. It may also reflect a reduction in RPE in the leg. In addition, high-intensity IMW may improve exercise performance. [ABSTRACT FROM AUTHOR]

Lung function has never been assessed during kangaroo mother care (KMC) in preterm infants. We measured lung (rSO2L) and cerebral (rSO2C) oxygenation by near-infrared spectroscopy (NIRS) in infants born at less than 32 weeks of gestation or weighing ≤ 1500 g during KMC. rSO2L, rSO2C, and pulmonary (FOEL) and cerebral (FOEC) tissue oxygen extraction fraction were measured in 20 preterm infants before, during, and after a 2-h period of KMC at a mean postnatal age of 36 ± 21 days of life. We found that rSO2L, rSO2C, FOEL, and FOEC did not change in our patients. After 120 min of KMC, rSO2L was lower (71.3 ± 1.4 vs. 76.7 ± 4.6%; P = 0.012) in infants with BPD (n = 6; 30%) than in infants without BPD (n = 14 = 60%), while FOEL was higher (0.26 ± 0.02 vs. 0.20 ± 0.05; P = 0.012). Conclusion: Cerebral and lung oxygenation did not change in preterm infants during KMC. A transient decrease in lung oxygenation was offset by the increase in oxygen extraction, but these changes were clinically insignificant. These results confirm the safety of KMC in preterm infants who are in stable clinical conditions. What is Known • Kangaroo mother care (KMC) is widely used to improve the care of preterm newborns since it improves their outcome. • KMC is safe as patients' vital parameters, are not negatively affected, but lung function has never been directly assessed. What is New • Cerebral and lung oxygenation measured by near-infrared spectroscopy did not change during KMC. • A transient decrease in lung oxygenation compensated for by the increase in oxygen extraction occurred only in infants with BPD, but these changes were clinically insignificant. [ABSTRACT FROM AUTHOR]

In the column chromatography elution process of traditional Chinese medicine (TCM), the real-time monitoring of active components plays an important role in product quality control. In this study, the column chromatography elution process in preparing of Ginkgo biloba leaf extract was performed in bench scale, where near-infrared (NIR) spectroscopy and Raman spectroscopy were collected to determine the concentration changes of several critical quality attributes. Based on single spectral data and fused spectral data, partial least squares and support vector machine models were established, respectively. The results indicated that for most analytes, models based on Raman spectra were superior to NIR spectral models, and fusion models established by the mid-level data fusion approach were superior to the single spectral models. The coefficients of determination (R t 2) of the optimal Raman and mid-level data fusion models were all higher than 0.96. The concentration profiles predicted by the mid-level data fusion quantitative models were in better agreement with the real trends defined by measured values. This is the first-ever study reporting the real-time monitoring of TCM column chromatography process by Raman spectroscopy combined with NIR spectroscopy, having vital reference values for process monitoring and understanding of the column chromatography for other TCM. [Display omitted] • The elution process of Ginkgo biloba leaves was monitored by near-infrared and Raman. • Partial least squares and support vector machine were used for quantitative analysis. • The mid-level data fusion models showed the better prediction ability. • Data fusion was a promising method for the analysis of column chromatography process. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy (NIRS) can be used to demonstrate muscle metabolism and oxygenation. NIRS-based oximeters enable the noninvasive measurement of static and dynamic muscle oxygenation. This study aimed to evaluate the relationship between NIRS readings and exercise capacity in group E COPD patients. The prospective study included 40 patients with group E COPD who presented to our outpatient clinic between May 2021 and June 2022. The patients were evaluated with pulmonary function testing, 6-Minute Walk Test (6MWT), echocardiography, and dyspnea and quality of life assessments. NIRS muscle oxygen saturation (SmO2) levels at the start and end of the 6MWT were obtained. 6MWT distance was positively correlated with intercostal SmO2 and fingertip SO2 at the start (R = 0.679, p ≤ 0.001 and R = 0.321, p = 0.04, respectively) and end of the 6MWT (R = 0.693, p ≤ 0.001 and R = 0.635, p ≤ 0.001, respectively) and negatively correlated with the number of hospitalizations due to exacerbations in the last year and mean pulmonary arterial pressure (R = − 0.648, p ≤ 0.001 and R = − 0.676, p ≤ 0.001, respectively). SF-36 score was positively correlated with intercostal SmO2 at the beginning of the 6MWT (R = 0.336, p = 0.03). Intercostal SmO2 levels at the start of the 6MWT positively correlated with diffusing capacity of the lung for carbon dioxide (DLCO) (R = 0.388, p = 0.01) and ratio of DLCO to alveolar volume (DLCO/VA) levels (R = 0.379, p = 0.02), and these correlations persisted more strongly after the 6MWT (R = 0.524, p = 0.01; R = 0.500, p = 0.01, respectively). NIRS is a practical and noninvasive method for measuring muscle oxygenation and can be used as an alternative to 6MWT in the evaluation of exercise capacity in patients with group E COPD. [ABSTRACT FROM AUTHOR]

To compare brain injury biomarker release levels between two different cardiopulmonary bypass (CPB) flow rates in elective cardiac surgery and to explore differences in postoperative delirium between groups and associations between age, sex, CPB time, oxygen levels, and near-infrared spectroscopy, and biomarker levels. A randomized controlled substudy trial Sahlgrenska University Hospital, Sweden Forty patients undergoing elective cardiac surgery with CPB Patients were assigned at random to either a standard (2.4 L/min/m2) or a high (2.9 L/min/m2) CPB flow rate. Glial fibrillary acidic protein, neurofilament light chain, total-tau, and phosphorylated-tau217 were sampled in plasma before anesthesia induction, after 60 minutes on CPB, and at 30 minutes, 24 hours, and 72 hours post-CPB. Mixed models for repeated measures were used to analyze differences in biomarker levels between groups and to assess relationships, which showed no differences between the 2 flow rate groups. There also was no difference in the occurrence of delirium between the 2 groups. Associations were found between age and increased neurofilament light chain levels. Female sex, oxygen delivery >330 mL/min/m2, and near-infrared spectroscopy level >60% were associated with lower biomarker levels. An increased flow rate did not have any significant effects on biomarker levels compared to a standard flow rate. Several associations were identified between treatment characteristics and biomarker levels. No difference in delirium was seen. [ABSTRACT FROM AUTHOR]

Introduction: Cordyceps sinensis (CS) is a precious medicinal fungus. Wild CS (WCS) and artificial CS (ACS) are destroyed for their identification using traditional methods, which are time consuming and labor‐intensive. Therefore, it is crucial to establish a nondestructive identification method to rapidly screen WCS. Objective: The aim of this study was to provide technical support for rapid screening of CS and evaluation of its quality. The applicability of the model was improved through model transfer. Methods: In this study, continuous wavelet transform was used to analyze the differences in moisture content and active components between WCS and ACS from the perspective of characteristic molecular groups. A portable instrument and a laboratory benchtop instrument were used to determine CS spectra. Partial least squares discrimination analysis was conducted for the identification of WCS and ACS while preserving the original shape of CS. Moreover, improved principal component analysis was utilized to transfer the model between the two types of near‐infrared spectroscopy (NIRS) instruments. Results: The results demonstrated that three peaks, at 1443, 1941, and 2183 nm, were characteristic absorption peaks. The model based on NIRS could initially provide rapid differentiation between WCS and ACS. At the same time, the accuracy of the external test set was further improved to over 95% through forward transfer. Conclusion: Therefore, this method could be used for rapid screening of WCS and provides technical support for the nondestructive identification of CS and initial assessment of CS quality. The correct discrimination of CS has been improved through model transfer, and three characteristic peaks have been proposed to determine the quality of CS at 1443, 1941, and 2183 nm. [ABSTRACT FROM AUTHOR]

ABSTRACT Currently, the majority of methods to monitor cancer treatment through the analysis of body fluids are based on a highly selective detection of single molecules or cells. In this study, we are considering the analysis of the aqueous medium of liquid samples, that is, water, itself, using aquaphotomics and near‐infrared spectroscopy (NIR) for spectral data acquisition and processing, within cancer research. Water, as a molecular system, is a rich source of information about the current state of a patient, which can be extracted from near‐infrared spectra of liquid samples via simple algorithms based on multivariate data analysis. The reported results, obtained ex vivo of body fluids, demonstrate the potential of aquaphotomics in cancer research. [ABSTRACT FROM AUTHOR]

In non-invasive blood glucose measurement, the sensitivity of glucose-induced optical signals within human tissue is a crucial reference point. This study evaluates the sensitivity of glucose-induced diffuse reflectance in the 1000–1700 nm range. A key factor in understanding this sensitivity is the rate at which the scattering coefficient changes due to glucose, as it is significantly higher than in non-living media and predominantly influences the diffuse light signal level when blood glucose levels change. The study measured and calculated the changes in the scattering coefficient at 1314 nm, a wavelength chosen for its minimal interference from glucose absorption and other bodily constituents. Based on the Mie scattering theory and the results at 1314 nm, the changes in the scattering coefficient within the 1000–1700 nm range were estimated. Subsequently, the sensitivity of the glucose signal across this range was determined through Monte Carlo (MC) simulations. The findings from 25 human trials indicate that the measured sensitivities at five other typical wavelengths within this band generally align with the sensitivities calculated using the aforementioned method. This research can guide the identification of blood glucose signals and the selection of wavelengths for non-invasive blood glucose measurements. [ABSTRACT FROM AUTHOR]

Cruciferous vegetables and oilseeds are rich in glucosinolates that can transform into isothiocyanates upon enzymic hydrolysis during post-harvest handling, food preparation and/or digestion. Vegetables contain glucosinolates that have beneficial bioactivities, while glucosinolates in oilseeds might have anti-nutritional properties. It is therefore important to monitor and assess glucosinolates and isothiocyanates content through the food value chain as well as for optimized crop production. Vibrational spectroscopy methods, such as infrared (IR) spectroscopy, are used as a nondestructive, rapid and low-cost alternative to the current and common costly, destructive, and time-consuming techniques. This systematic review discusses and evaluates the recent literature available on the use of IR spectroscopy to determine glucosinolates and isothiocyanates in vegetables and oilseeds. NIR spectroscopy was used to predict glucosinolates in broccoli, kale, rocket, cabbage, Brussels sprouts, brown mustard, rapeseed, pennycress, and a combination of Brassicaceae family seeds. Only one study reported the use of NIR spectroscopy to predict broccoli isothiocyanates. The major limitations of these studies were the absence of the critical evaluation of errors associated with the reference method used to develop the calibration models and the lack of interpretation of loadings or regression coefficients used to predict glucosinolates. [ABSTRACT FROM AUTHOR]

Objective Cerebral oximetry using near-infrared spectroscopy (NIRS) is a noninvasive optical technology widely used in neonatology. The present study aimed to define reference ranges for cerebral tissue oxygen saturation (crSO 2) with a new four-wavelength NIRS device, Masimo O3 oximeter, during immediate transition after birth and compare values with those obtained previously with NIRO 200NX ®. Study Design This was a prospective observational study using Masimo O3 device to measure crSO 2 and regional cerebral fractional tissue oxygen extraction (cFTOE) in healthy term newborns delivered by primary cesarean section, during the 15 minutes after cord clamping. The neonates who required any medical support were excluded. The NIRS sensor was placed on the right forehead. Peripheral oxygen saturation and heart rate were continuously measured by pulse oximetry. Previous studies which established centiles for crSO 2 with NIRO 200NX were used for comparison. Results A total of 44 newborns were included. The median crSO 2 and cFTOE (interquartile range) at 2, 5, and 7 minutes was 54% (49–54), 71% (64–86), and 79% (73–84) and 0,25 (0,18–0,33), 0,19 (0,15–0,23), and 0,16 (0,12–0,21), respectively, with no further changes afterwards. The crSO 2 measurements were significantly higher with Masimo O3 compared with NIRO-200NX. Conclusion The present observational study presented reference ranges for crSO 2 and cFTOE measured with Masimo O3 oximeter during the immediate neonatal transition. Values obtained with O3 were higher than those obtained with other oximeters. For this reason, crSO 2 is device-specific so there must be known reference values for each oximeter to define therapeutic interventions based on crSO 2 and assess cerebral oxygenation in clinical studies. Key Points Masimo O3 uses four wavelengths to measure regional oxygen saturation value. O3 values of crSO 2 and cFTOE differ with other neonatal oximeters at birth. Knowledge of reference range of O3 at birth is essential to guide resuscitation. [ABSTRACT FROM AUTHOR]

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This study investigates the impact of a five-week functional exercise intervention designed to enhance the muscular endurance of the posterior shoulder musculature, aiming to mitigate shoulder fatigue and overuse injury. Twelve Division I collegiate butterfly swimmers were recruited and evenly randomized into exercise (EX) and control (CTRL) groups. Weekly 100-yard butterfly sprints were performed, with Muscle Oxygen Saturation (SmO2) continuously monitored using a wearable near-infrared spectroscopy (NIRS) device. This study is among the first to utilize wearable NIRS devices to monitor SmO2 underwater during swimming, demonstrating that a targeted 5-week exercise program significantly improves posterior shoulder endurance, as evidenced by increased Posterior Shoulder Endurance Test (PSET) scores and distinctive SmO2 adaptations in the EX-group compared to the CTRL group. These findings suggest that targeted dryland exercises can enhance posterior shoulder endurance with long-term implications for potentially reducing injury risk and improving performance. [ABSTRACT FROM AUTHOR]

Aortic coarctation surgery in pediatric patients requires the placement of two arterial cannulas to monitor pressure gradients and surgical correction adequacy. Near-infrared spectroscopy (NIRS) monitoring provides insight into regional blood flow. This study aimed to investigate the correlation between NIRS values and invasive arterial pressures, exploring NIRS monitoring as a potential substitute for arterial cannulation. In a cohort of 21 consecutive pediatric patients undergoing aortic coarctation surgery, recordings of NIRS and invasive arterial pressure values were evaluated at various time intervals. Pearson correlation evaluated the relationship between NIRS values and invasively measured arterial pressures. Moderate to strong correlations were observed between the mean arterial pressure (MAP) of the upper and lower arteries and cerebral (rSO2-C) and somatic (rSO2-S) NIRS values 5 min after cross-clamp placement (r = 0.621, p = 0.003; r = 0.757, p < 0.001). Strong correlations were found 15 min after cross-clamp placement (r = 0.828, p = 0.002; r = 0.783, p = 0.004). Before transfer to the ICU, a strong correlation existed between the upper artery MAP and rSO2-C (r = 0.730, p < 0.001), but there was no correlation between the lower artery MAP and rSO2-S. These findings are promising, but further studies are required to validate it as a reliable substitute for invasive pressure monitoring in this patient population. [ABSTRACT FROM AUTHOR]

Intravascular ultrasound and optical coherence tomography are used with increasing frequency for the care of coronary patients and in research studies. These imaging tools can identify culprit lesions in acute coronary syndromes, assess coronary stenosis severity, guide percutaneous coronary intervention (PCI), and detect vulnerable plaques and patients. However, they have significant limitations that have stimulated the development of multimodality intracoronary imaging catheters, which provide improvements in assessing vessel wall pathology and guiding PCI. Prototypes combining 2 or even 3 imaging probes with complementary attributes have been developed, and several multimodality systems have already been used in patients, with near-infrared spectroscopy intravascular ultrasound–based studies showing promising results for the identification of high-risk plaques. Moreover, postmortem histology studies have documented that hybrid imaging catheters can enable more accurate characterization of plaque morphology than standalone imaging. This review describes the evolution in the field of hybrid intracoronary imaging; presents the available multimodality catheters; and discusses their potential role in PCI guidance, vulnerable plaque detection, and the assessment of endovascular devices and emerging pharmacotherapies targeting atherosclerosis. [Display omitted] • Novel hybrid intracoronary devices overcome limitations of standalone imaging for plaque characterization and PCI guidance. • The use of multimodality imaging may improve outcomes following interventional treatment in challenging clinical scenarios. • Large-scale studies are needed to determine the role of hybrid intracoronary imaging in guiding revascularization, vulnerable plaque detection, and cardiovascular risk stratification. [ABSTRACT FROM AUTHOR]

Near infrared spectroscopy (NIRS) is an analytical technique that offers a real advantage over laboratory analysis in the food industry due to its low operating costs, rapid analysis, and non‐destructive sampling technique. Numerous studies have shown the relevance of NIR spectra analysis for assessing certain food properties with the right calibration. This makes it useful in quality control and in the continuous monitoring of food processing. However, the NIR calibration process is difficult and time‐consuming. Analysis methods and techniques vary according to the configuration of the NIR instrument, the sample to be analyzed and the attribute that is to be predicted. This makes calibration a challenge for many manufacturers. This paper aims to provide a data‐driven methodology for developing a decision support tool based on the smart selection of NIRS wavelength to assess various food properties. The decision support tool based on the methodology has been evaluated on samples of cocoa beans, grains of wheat and mangoes. Promising results were obtained for each of the selected models for the moisture and fat content of cocoa beans (R2cv: 0.90, R2test: 0.93, RMSEP: 0.354%; R2cv: 0.73, R2test: 0.79, RMSEP: 0.913%), acidity and vitamin C content of mangoes (R2cv: 0.93, R2test: 0.97, RMSEP: 17.40%; R2cv: 0.66, R2test: 0.46, RMSEP: 0.848%), and protein content of wheat—DS2 (R2cv: 0.90, R2test:0.92, RMSEP: 0.490%) respectively. Moreover, the proposed approach allows results to be obtained that are better than benchmarks for the moisture and protein content of wheat—DS1 (R2cv: 0.90, R2test: 94, RMSEP: 0.337%; R2cv: 0.99, R2test: 0.99, RMSEP: 0.177%), respectively. Practical Application: This research introduces a practical tool aimed at determining the quality of food by identifying specific light wavelengths. However, it is important to acknowledge potential challenges, such as overfitting. Before implementation, it is crucial for further research to address and mitigate the issues to ensure the reliability and accuracy of the solution. If successfully applied, this tool could significantly enhance the accuracy of near‐infrared spectroscopy in assessing food quality attributes. This advancement would provide invaluable support for decision‐making in industries involved in food production, ultimately leading to better overall product quality for consumers. [ABSTRACT FROM AUTHOR]

In the processing of polymer blends and composites, in-line near-infrared (NIR) spectroscopy enables monitoring of the composition and its composite uniformity and contributes to rapid process development and quality control. However, in the injection molding process, the study of the composition of polymer materials has been delayed due to high-pressure conditions. Our research group developed NIR probes for transmission and diffuse reflectance measurements that can withstand high-pressure and temperature conditions up to 130 MPa and 200 °C. In this research, transmission and diffuse reflectance spectra were measured inline during the injection molding process of polymer blends of poly(lactic acid) and polybutylene succinate adipate. The intensity of each polymer band in the second-derivative spectra exhibited a monotonic increase or decrease in response to changes in the blend ratio. Using transmission and diffuse reflectance spectra as explanatory variables of the partial least squares regression model simultaneously, the model showed high estimation accuracy for the entire region of the blend ratio. Finally, this model was applied to monitor the polymer changeover operation, and the change in the blend ratio in the molded product was successfully estimated in line. [ABSTRACT FROM AUTHOR]

We assessed the feasibility of concurrent monitoring of cerebral hemodynamics in adult, comatose out-of-hospital cardiac arrest (OHCA) patients admitted to the National University Heart Centre Singapore from October 2021 to August 2023. Patients underwent continuous near-infrared spectroscopy (NIRS) monitoring in the first 72 h after return of spontaneous circulation (ROSC) and 30-min transcranial Doppler ultrasound (TCD) monitoring at least once. With constant mechanical ventilatory settings and continuous electrocardiographic, pulse oximeter and end-tidal carbon dioxide monitoring, blood pressure was manipulated via vasopressors and cerebral autoregulation assessed by measuring changes in regional cerebral oxygenation (NIRS) and cerebral blood flow velocities (TCD) in response to changes in mean arterial pressure. The primary outcome was neurological recovery at hospital discharge. Amongst the first 16 patients (median age 61, 94% males), we observed four unique patterns: preserved cerebral autoregulation, loss of cerebral autoregulation, cardio-cerebral asynchrony and cerebral circulatory arrest. Patients with preserved cerebral autoregulation had lower levels of neuro-injury biomarkers (neurofilaments light and heavy) and the majority (86%) were discharged with good neurological recovery. Multi-modal assessment of cerebral hemodynamics after OHCA is feasible and derived patterns correlated with neurological outcomes. The between- and within-patient heterogeneity in cerebral hemodynamics calls for more research on individualized treatment strategies. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) spectroscopy has emerged as a popular technique for assessing food quality due to its advantages over complex chemical analysis methods. However, the application of NIR spectroscopy for evaluating fish quality based on histamine content has not been extensively explored. This study investigates the use of NIR spectroscopy in combination with machine learning (ML) techniques to classify fish samples into two safety classes, Safe and Unsafe, based on their histamine content. A comprehensive NIR dataset comprising 11,360 spectra collected at eight distinct positions within the fish body was obtained from 284 fish samples of mackerel, tuna, and pompano species. ML experiments were conducted to classify fish samples based on whether their histamine content exceeded the permissible limit of 100 ppm. To address class imbalance and optimize ML models, various data pre-processing and feature extraction techniques as well as ML algorithms were explored. The results demonstrated that utilizing NIR data specifically obtained from the tail's flesh, a specific location within the fish, yielded superior models for fish safety classification. A feature extraction method employing pre-processed NIR spectra and their second derivatives, combined with an optimized convolutional neural network architecture, outperformed traditional ML classifiers with an accuracy of approximately 93%. [ABSTRACT FROM AUTHOR]

The background differences in water content of different samples have a very strong influence on the robustness of near-infrared spectroscopy (NIRS). For this reason, this study simulated typical biological water matrix samples with formulated hemoglobin (Hb), glucose (Glc), and distilled water, and attempted to use four different intelligent spectral variable selection algorithms [Competitive Adaptive Reweighted Sampling (CARS), Randomized Frog Hopping Algorithm (RF), Genetic Algorithm (GA), and Variable Projection Importance Algorithm (VIP)] to perform the Hb water interference-resistant feature band preferences, while combining partial least squares (PLS) in parallel to build a robust quantitative model of Hb. In addition, the applicability and validity of the model were validated using three prediction sets P1, P2, P3 with different water backgrounds (the formulation method and composition were kept the same, and only the water content increased sequentially). The results showed that RF, GA, and VIP could effectively screen out the characteristic wavelengths of Hb with low sensitivity to water changes and successfully correct the water effect, but due to the large number of characteristic variables they screened out and the existence of a large number of redundant and water interference variables, this ultimately made the model's robustness less than ideal. The CARS algorithm performed the best, and the RMSEP of the three prediction sets were 0.016, 0.017, and 0.038, which is closer to the RMSECV of the calibration set. Therefore, NIRS combined with the variable selection can reduce the effect of water on model robustness and improve the prediction accuracy of the model by the method of selecting effective wave number intervals, and CARS may be one of the ideal algorithms to solve such problems. [ABSTRACT FROM AUTHOR]

A predictive model utilizing near-infrared spectroscopy was developed to estimate the loss on drying, total contents of crocin I and crocin II, and picrocrocin content of saffron. Initially, the LD values were determined using a moisture-ash analyzer, while HPLC was employed for measuring the total contents of crocin I, crocin II, and picrocrocin. The near-infrared spectra of 928 saffron samples were collected and preprocessed using first derivative, standard normal variable transformation, detrended correction, multivariate scattering correction, Savitzky–Golay smoothing, and mean centering methods. Leveraging the partial least squares method, regression models were constructed, with parameters optimized through a selective combination of the above six preprocessing methods. Subsequently, prediction models for loss on drying, total contents of crocin I and crocin II, and picrocrocin content were established, and the prediction accuracy of the models was verified. The correlation coefficients and root mean square error of loss on drying, total contents of crocin I and crocin II, and picrocrocin content demonstrated high accuracy, with R2 values of 0.8627, 0.8851, and 0.8592 and root mean square error values of 0.0260, 0.0682, and 0.0465. This near-infrared prediction model established in the present study offers a precise and efficient means of assessing loss on drying, total contents of crocin I and crocin II, and picrocrocin content in saffron and is useful for the development of a rapid quality evaluation system. [ABSTRACT FROM AUTHOR]

Objective: The main objective of this study was to compare lactate thresholds and aerobic capacity from a graded-intensity exercise test (GXT) for near-infrared spectroscopy measurements in healthy, untrained individuals and highly trained athletes. Methods: This study included 29 untrained students (13 females) and 27 highly trained speed skaters (13 females). A maximal effort GXT was performed on a cycloergometer. The lactate-based aerobic and anaerobic thresholds, and the corresponding thresholds for muscle oxygen saturation (SmO2), were determined. Results: The power values determined for all thresholds were significantly higher in female and male speed skaters compared to male and female college students. SmO2 at anaerobic thresholds was significantly lower in female speed skaters than in female students. Both female and male skaters showed greater changes in SmO2 after the GXT compared to students. The recovery did not significantly differ between groups within gender. There was a significant positive correlation in females between the rate of muscle reoxygenation and VO2max power (r = 0.610). In speed skaters, the rate of muscle reoxygenation was not significantly higher than students and correlated positively with VO2max (r = 0.449). Conclusions: The SmO2 at the exercise thresholds, during and after maximal exercise, depends on the training status of the individual. The participants with a higher physical fitness level showed greater decreases in ΔSmO2 at the AT level, as well as after maximal exercise. SmO2 corresponding to the well-established exercise thresholds may be applied to guide training prescription. The rate of muscle reoxygenation after a GXT was also dependent on the aerobic capacity of the participants. [ABSTRACT FROM AUTHOR]

As a mature non-destructive testing technology, near-infrared (NIR) spectroscopy can effectively identify and distinguish the structural characteristics of wood. The Wood Defect One-Dimensional Visual Geometry Group 19-Finite Element Analysis (WD-1D-VGG19-FEA) algorithm is used in this study. 1D-VGG19 classifies the near-infrared spectroscopy data to determine the knot area, fiber deviation area, transition area, and net wood area of the solid wood board surface and generates a two-dimensional image of the board surface through inversion. Then, the nonlinear three-dimensional model of wood with defects was established by using the inverse image, and the finite element analysis was carried out to predict the elastic modulus of wood. In the experiment, 270 points were selected from each of the four regions of the wood, totaling 1080 sets of near-infrared data, and the 1D-VGG19 model was used for classification. The results showed that the identification accuracy of the knot area was 95.1%, the fiber deviation area was 92.7%, the transition area was 90.2%, the net wood area was 100%, and the average accuracy was 94.5%. The error range of the elastic modulus prediction of the three-dimensional model established by the VGG19 classification model in the finite element analysis is between 2% and 10%, the root mean square error (RMSE) is about 598. 2, and the coefficient of determination (R2) is 0. 91. This study shows that the combination of the VGG19 algorithm and finite element analysis can accurately describe the nonlinear defect morphology of wood, thus establishing a more accurate prediction model of wood mechanical properties to maximize the use of wood mechanical properties. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy combined with vascular occlusion test (NIRS-VOT) is a reactive hyperemia technique for in vivo evaluation of skeletal muscle microvascular reactivity. Previous studies using NIRS-VOT have been shown to be able to detect impairments in microvascular function in high-risk cardiovascular disease populations, such as older individuals. It has been demonstrated that older individuals have slower reactive hyperemia compared with young individuals. Importantly, older individuals also show less desaturation during ischemia compared with young individuals. Based on these findings, it has been suggested that the slower reactive hyperemia observed in older individuals is explained by the lower desaturation during blood flow occlusion (reduced ischemic stimulus). This retrospective analysis compared reactive hyperemia in 36 young and 47 older tissue desaturation-matched individuals that underwent 5-min blood flow occlusion. Overall, we showed that older individuals have impaired reactive hyperemia compared with young when matching for the degree of desaturation and blood flow occlusion time. These findings provide evidence that lower tissue desaturation during ischemia is not a major determinant of impaired reactive hyperemia in older individuals. NEW & NOTEWORTHY: Previous findings have suggested that aging-related impairment in skeletal muscle reactive hyperemia is majorly influenced by a lower degree of tissue desaturation during ischemia in older individuals compared with young individuals. In a retrospective analysis including 83 tissue desaturation-matched individuals, we show that the degree of tissue desaturation is not a major determinant of aging-related impairments in reactive hyperemia. [ABSTRACT FROM AUTHOR]

Neuromonitoring has been widely accepted as an important part in neonatal care. Amplitude-integrated EEG (aEEG) and near-infrared spectroscopy (NIRS) are often mentioned in this context, though being only a part of the fully array of methods and examinations that could be considered neuromonitoring. Within the broad array of medical conditions that could be encountered in a neonatal patient, it is important to be aware of the indications for neuromonitoring and especially which neuromonitoring technique to use best for the individual condition. aEEG is now a widely accepted neuromonitor in neonatology with its value in hypoxic events and seizures only rarely questioned. Other methods like NIRS still have to prove themselves in the future. The SafeBoosC-III trial showed that it still remains difficult for some of these methods to prove their value for the improvement of outcome. Bute future developments such as multimodal neuromonitoring with data integration and artificial intelligence analysis could improve the value of these methods. [ABSTRACT FROM AUTHOR]

Cerebral monitoring during immediate fetal-to-neonatal transition is of increasing interest. The cerebral fractional tissue oxygen extraction (cFTOE) is a useful parameter to gain insight in the balance between tissue oxygen delivery and consumption during this complex process. The aim of this study was to review the literature on cFTOE during the first 15 min immediately after birth. A systematic qualitative literature research was last performed on 23 November 2023 of PubMed and EMBASE with the following search terms: neonate, infant, newborn, transition, after birth, delivery room, NIRS, near-infrared spectroscopy, spectroscopy, cFTOE, cerebral fractional tissue oxygenation extraction, cerebral oxygenation, and fractional oxygen extraction. Additional published reports were identified through a manual search of references in retrieved articles and in review articles. The methodological quality of the included studies was assessed by predefined quality criteria. Only human studies with data of cFTOE in the first 15 min after birth were included. Accordingly, exclusion criteria were defined as no measurement of cFTOE or no measurement within the first 15 min after birth. Across all studies, a total of 3566 infants (2423 term, 1143 preterm infants) were analysed. Twenty-five studies were identified describing cFTOE within the first 15 min after birth. Four studies established reference ranges for cFTOE and another four studies focused on the effect of pre-/perinatal circumstances on cFTOE in the first 15 min after birth. Six studies investigated the course of cFTOE after transition in infants without complications. Eleven studies analysed different potentially influencing parameters on cFTOE during transition. Conclusion: This systematic review provides a comprehensive insight on cFTOE during uncomplicated transition as well as the influence of perinatal circumstances, respiratory, haemodynamic, neurological, and laboratory parameters in preterm and term infants. What is Known: • The NIRS-measured cerebral fractional tissue oxygen extraction (cFTOE) is a useful parameter to estimate the balance between oxygen delivery and consumption. • During normal transition, the cFTOE decreases in the first minutes after birth and then remains at a stable plateau. What is New: • The cFTOE is a promising parameter that gives additional information on cerebral oxygenation and perfusion in preterm and term infants. • Several hemodynamic, metabolic, respiratory, and perinatal factors are identified, influencing the oxygen extraction of the newborn's brain after birth. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this study was to identify the cerebral physiologic response to aerobic exercise in individuals with a symptomatic concussion, highlighting available knowledge and knowledge gaps in the literature. Design: A systematic scoping review was conducted and reported in keeping with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. A search of EMBASE, MEDLINE, SCOPUS, BIOSIS, and Cochrane libraries was conducted on June 15, 2023 (from database inception). An online systematic/scoping review management system was used to remove duplicates, and the remaining articles were screened for inclusion by 2 researchers. Inclusion criteria required articles to be original research published in peer- reviewed journals. Additionally, studies were required to have an aerobic exercise component, include a measure of cerebral physiology during a bout of aerobic exercise, exclude moderate and/or severe traumatic brain injury (TBI) populations, and be in the English language. Both human and animal studies were included, with participants of any age who were diagnosed with a mild TBI/concussion only (ie, Glasgow Coma Scale score ≥ 13). Studies could be of any design as long as a measure of cerebral physiologic response to a bout of aerobic exercise was included. Results: The search resulted in 1773 articles to be screened and data from 3 eligible studies were extracted. Conclusions: There are currently too few studies investigating the cerebral physiologic response to aerobic exercise following concussion or mild TBI to draw definitive conclusions. Further research on this topic is necessary since understanding the cerebral physiologic response to aerobic exercise in the concussion and mild TBI populations could assist in optimizing exercise-based treatment prescription and identifying other targeted therapies. [ABSTRACT FROM AUTHOR]

Despite the recommendation to treat depression using transcranial direct current stimulation (tDCS), novel findings raise doubts over the tDCS's efficacy in managing depressive episodes. Neurophysiologic approaches to understanding the specificities of brain responses to tDCS in patients with depression remain to be explored. Objective: Our aim was to compare immediate hemodynamic responses to tDCS on the left dorsolateral prefrontal cortex (DLPFC; F3-Fp2 montage) in patients with depressive disorder and in controls (no additional stimuli). Methods: Sixteen participants were allocated to the depression group and sixteen to the control group. Both groups received 2 mA tDCS for 20 min, using the F3-Fp2 montage. The hemodynamic effect over the DLPFC was assessed using functional near-infrared intracranial spectroscopy (fNIRS) positioned on the left supraorbital region (Fp1). Mean, minimal, and maximal values of baseline and post-stimulation rates of oxygen saturation (SatO2) were recorded. The oxygenated hemoglobin rates (HbO) were extracted. Results: Between-group differences were detected for minimal baseline rates of SatO2 and HbO levels. The depression group showed lower results compared to the control group at baseline. After the protocol, only the depression group showed increased minimal rates of SatO2 and HbO. The post-tDCS minimal rates were equal for both groups. Conclusions: The findings showed immediate anodal tDCS effects over DLPFC hemodynamics. The effects were exclusive to the lowest baseline rate group and did not affect the normal oxygen rate group. The minimal increase in SatO2 and HbO rates after the protocol in the depression group suggests that those with reduced cerebral perfusion may be more affected by tDCS. [ABSTRACT FROM AUTHOR]

The assessment of catechin content stands as a pivotal determinant of tea quality. In tea production and quality grading, the development of accurate and non-destructive techniques for the accurate prediction of various catechin content is paramount. Near-infrared spectroscopy (NIRS) has emerged as a widely employed tool for analyzing the chemical composition of tea. Nevertheless, the spectral information obtained from NIRS faces challenges when discerning different types of catechins in black tea, owing to their similar physical and chemical properties. Moreover, the vast number of NIRS wavelengths exceeds the available tea samples, further complicating the accurate assessment of catechin content. This study introduces a novel deep learning approach that integrates specific wavelength selection and attention mechanisms to accurately predict the content of various catechins in black tea simultaneously. First, a wavelength selection algorithm is proposed based on feature interval combination sensitivity segmentation, which effectively extracts the NIRS feature information of tea. Subsequently, a one-dimensional convolutional neural network (CNN) incorporating channel and spatial–sequential attention mechanisms is devised to independently extract the key features from the selected wavelength variables. Finally, a multi-output predictor is employed to accurately predict the four main catechins in tea. The experimental results demonstrate the superiority of the proposed model over existing methods in terms of prediction accuracy and stability (R2 = 0.92, RMSE = 0.018 for epicatechin; R2 = 0.96, RMSE = 0.11 for epicatechin gallate; R2 = 0.97, RMSE = 0.14 for epigallocatechin; R2 = 0.97, RMSE = 0.32 for epigallocatechin gallate). This innovative deep learning approach amalgamates wavelength selection with attention mechanisms, provides a new perspective for the simultaneous assessment of the major components in tea, and contributes to the advancement of precision management in the tea industry's production and grading processes. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy has become an important methodology for rapid and non-destructive detection in food and agricultural fields. However, the accuracy of quantitative analysis was seriously restricted by the severe overlap of spectra and the high cost of standard samples. In order to reduce the impact of these problems especially that of small sample size problem, a novel method named weighted clustering ensemble partial least squares (WCE-PLS) is proposed for the protein content analysis of corn. Firstly, the clustering and sampling strategy is introduced in the calibration sets of corn to create different subsets for generating sub-models. Then, root mean square errors of cross-validation (RMSECV) in those sub-models as the crucial criterion are computed for model optimization. Finally, in integrating step, two Gaussian weighted functions used to determine the weights of sub-models are defined. The validation performance of the proposed method is tested with the near infrared spectral data sets of corn and compared with single PLS, bagging PLS, boosting PLS, and data augmentation (DA) PLS. To further demonstrate the effectiveness of the method, another data set of soil was used for supplementary verification. Results of the prediction sets indicated that the RMSEP values of the WCE-PLS are obviously smaller than that of boosting PLS. And the RMSEP of WCE-PLS and bagging PLS is relatively small in most cases. Furthermore, the correlation coefficients between predicted value and chemical value are respectively 0.96587 and 0.90849 for two data sets, which computed by the WCE-PLS is obviously higher than that computed by the other four methods. And the t test also showed the WCE-PLS has smaller t values and larger p values. [ABSTRACT FROM AUTHOR]

Background: The ability to hang for a long time before forearm muscle fatigue is a crucial element of successful rock climbing. Electromyography (EMG) and near-infrared spectroscopy (NIRS) are also useful for measuring hemoglobin oxygenation for determining muscle endurance. In the present study, we aimed to evaluate the reliability and validity of muscle endurance indices derived using EMG and NIRS during a hanging task. Methods: A bilateral hanging task was designed to compare rock climbers and non-climbers in terms of the slopes of changes in the median frequency (MDF) and tissue oxygenation index (TOI) of forearm muscles. Results: A total of 17 participants were included in each of the two groups. The intraclass correlation coefficient (3,1) values derived for the MDF slope, TOI slope, ΔTOI, percentage change in oxygen concentration, and ΔHbt were 0.85, 0.73, 0.65, 0.75, and 0.65, respectively. The MDF slope, TOI slope, and ΔHbt differed significantly between the groups (p < 0.05). The MDF slope, TOI slopes, and ΔHbt were significantly correlated with V-scale levels for climbing (p < 0.05). Conclusions: The satisfactory reliability and observed distinctions between climbers and non-climbers imply that these indices are a valuable tool for assessing muscle endurance. [ABSTRACT FROM AUTHOR]

This study measured the infrared spectra of secondary minerals in the oxidation zones of three types of copper ores: dioptase, malachite, and azurite, and assigned the peak positions of OH stretching vibrations and the origins of OH combination vibrations. Dioptase contains three types of water molecules with different orientations within its ring channels, which exhibit six kinds of OH stretching vibrations in the 3000–3600 cm−1 range; the bond length range is 2.652 to 2.887 Å. Among them, the 3443 cm−1 band shows strong near-infrared activity and combines with Si–O vibrations or OH bending vibrations in the structure, resulting in five combination vibration peaks in the 4000–5000 cm−1 range. Malachite contains two inequivalent hydroxyls in its structure, leading to two OH stretching vibrations in the high-frequency region located at 3314 and 3402 cm−1, respectively. Azurite contains only one type of hydroxyl, and thus only one characteristic OH stretching vibration is present at 3424 cm−1. The OH stretching vibrations of malachite and azurite mainly combine with [CO3]2− vibrations or OH bending vibrations, leading to six and five combination peaks in the OH combination vibration region, respectively. By analyzing the combination of peak positions at 4341 cm−1 in the near-infrared spectrum, the merged OH bending vibration at 921 cm−1 in azurite was discovered. Spectroscopic research on secondary minerals can better provide a basis for ore exploration and geological remote sensing. [ABSTRACT FROM AUTHOR]

The study developed a novel method for evaluating the freshness of citrus fruits by integrating near-infrared spectroscopy with the non-linear data processing capabilities of a BP neural network. This approach utilizes specific wavelength analysis to distinguish between fresh and non-fresh fruits effectively. Advanced pre-processing techniques are employed to remove spectral anomalies, enhancing the network's ability to accurately identify crucial quality indicators like sugar content. Concurrently, an experiment utilizing a mathematical computing software -based BP neural network optimized the number of hidden layer nodes, identifying 61 as optimal. This configuration achieves impressive indicators, including a mean square error of 0.0025665 and a root mean square error of 49.8214. More than 1000 training iterations were performed on 100 citrus samples, and the learning rate was 80%. The model demonstrated a high accuracy rate of 97.6275%, confirming its precision and reliability in assessing citrus freshness. This synergy between advanced neural network processing and spectroscopic techniques marks a significant advancement in agricultural quality assessment, setting new standards for speed and efficiency in data processing. [ABSTRACT FROM AUTHOR]

Introduction: Wearable near-infrared spectroscopy (NIRS) can be used during dynamic exercise to reflect the balance of muscle oxygen delivery and uptake. This study describes the behaviour and reliability of postexercise reoxygenation with NIRS as a function of exercise intensity at four muscle sites during an incremental cycling test. We discuss physiological components of faster and slower reoxygenation kinetics in the context of sport science and clinical applications. We hypothesised that reoxygenation would be slower at higher intensity, and that locomotor muscles would be faster than accessory muscles. We quantified test-retest reliability and agreement for each site. Methods: Twenty-one trained cyclists performed two trials of an incremental cycling protocol with 5-min work stages and 1-min rest between stages. NIRS was recorded from the locomotor vastus lateralis and rectus femoris muscles, and accessory lumbar paraspinal and lateral deltoid muscles. Reoxygenation time course was analysed as the half-recovery time (HRT) from the end of work to half of the peak reoxygenation amplitude during rest. Coefficient of variability (CV) between participants, standard error of the measurement (SEM) within participants, and intraclass correlation coefficient (ICC) for test-retest reliability were evaluated at 50%, 75%, and 100% peak workloads. A linear mixed-effects model was used to compare differences between workloads and muscle sites. Results: HRT was slower with increasing workload in the VL, RF, and PS, but not DL. VL had the fastest reoxygenation (lowest HRT) across muscle sites at all workloads (HRT = 8, 12, 17 s at 50%, 75%, 100% workload, respectively). VL also had the greatest reliability and agreement. HRT was sequentially slower between muscle sites in the order of VL < RF < PS < DL, and reliability was lower than for the VL. Discussion: This study highlights the potential for using wearable NIRS on multiple muscle sites during exercise. Reoxygenation kinetics differ between local muscle sites with increasing intensity. Moderate-to-good reliability in the VL support its increasing use in sport science and clinical applications. Lower reliability in other muscle sites suggest they are not appropriate to be used alone, but may add information when combined to better reflect systemic intensity and fatigue during exercise at different intensities. [ABSTRACT FROM AUTHOR]

Fourier-transform near-infrared spectroscopy (FT-NIRS) has recently been used to reduce the processing time for estimates of annual age in several fish species. The present study represents the first application of this technique to marine organisms from the European waters. Atlantic horse mackerel (Trachurus trachurus) from the central Mediterranean Sea was selected for its ecological role, its socioeconomic value, and because its age is regularly estimated by otolith reading under a stereomicroscope for stock assessment purposes. Absorption spectra of the whole otoliths were acquired by FT-NIRS across a multiyear dataset, obtained during acoustic surveys carried out in different regions of the central Mediterranean Sea. The acquired spectra were processed to optimize calibration models to predict age. The best linear models obtained by the optimizing procedure predicted age successfully with a coefficient of determination of 0.95-0.96, mean squared error of 0.5 years, and bias <0.03 years. Although regional calibration models were also obtained separately, the models with all regions combined appeared much more robust and encompassing the whole age range, suggesting its usefulness for the entire spatial distribution range considered in the preset study. The use of FT-NIRS allowed to successfully predict age for horsemackerel between the ages 1 and 14, with similar or better precision (and bias) of the traditional methods, also increasing the standardization by repeatability of age assignments. The preliminary results obtained by this study encourage further effort to fine-tune the calibration model for new species, in order to apply a precise, rapid, costeffective method for stock assessment purposes of Mediterranean fish resources. [ABSTRACT FROM AUTHOR]

The trail making test (TMT) is a commonly used tool for evaluating executive functions, and the activation of cerebral oxygenation in the prefrontal cortex (PFC) during the test can reflect the participation of executive function. This study aimed to compare the differences in cerebral oxygenation in the PFC between the computer- and paper-based versions of the TMT and provide a theoretical basis for the optimization and clinical application of the computer-based version. A total of 32 healthy adult participants completed the computer- and paper-based TMT Types A and B. Cerebral oxygenation changes in the PFC were monitored during the experiment using near-infrared spectroscopy. Moreover, average changes in oxyhemoglobin (Δoxy-Hb) levels at the baseline and during activation periods in different types of testing were compared and analyzed. The number of correct connections in the computer-based version Type B was less than that in the paper-based version Type B (p <.001). The task time of the computer-based version was longer than that of the paper-based version (p <.001). The B/A ratio of the number of correct connections in the computer-based version was lower than that in the paper-based version (p <.001). The Δoxy-Hb in the PFC of the paper-based version was higher than that of the computer-based version (p <.001). Significant differences in oxygenation in the PFC were observed between the paper- and computer-based versions of TMT. After further improvement and correction in the subsequent development of the computer-based TMT, and taking into account the psychological feelings and preferences of the participants when performing different versions of the TMTs, the computer-based TMT is expected to play a good auxiliary role in clinical evaluation. [ABSTRACT FROM AUTHOR]

The success of near-infrared spectroscopy (NIRS) analysis hinges on the precision and robustness of the calibration model. Shallow learning (SL) algorithms like partial least squares discriminant analysis (PLS-DA) often fall short in capturing the interrelationships between adjacent spectral variables, and the analysis results are easily affected by spectral noise, which dramatically limits the breadth and depth of applications of NIRS. Deep learning (DL) methods, with their capacity to discern intricate features from limited samples, have been progressively integrated into NIRS. In this paper, two discriminant analysis problems, including wheat kernels and Yali pears as examples, and several representative calibration models were used to research the robustness and effectiveness of the model. Additionally, this article proposed a near-infrared calibration model, which was based on the Gramian angular difference field method and coordinate attention convolutional neural networks (G-CACNNs). The research results show that, compared with SL, spectral preprocessing has a smaller impact on the analysis accuracy of consensus learning (CL) and DL, and the latter has the highest analysis accuracy in the modeling results using the original spectrum. The accuracy of G-CACNNs in two discrimination tasks was 98.48% and 99.39%. Finally, this research compared the performance of various models under noise to evaluate the robustness and noise resistance of the proposed method. [ABSTRACT FROM AUTHOR]

Background: Rapid monitoring of biomass conversion processes using techniques such as near-infrared (NIR) spectroscopy can be substantially quicker and less labor-, resource-, and energy-intensive than conventional measurement techniques such as gas or liquid chromatography (GC or LC) due to the lack of solvents and preparation methods, as well as removing the need to transfer samples to an external lab for analytical evaluation. The purpose of this study was to determine the feasibility of rapid monitoring of a biomass conversion process using NIR spectroscopy combined with multivariate statistical modeling, and to examine the impact of (1) subsetting the samples in the original dataset by process location and (2) reducing the spectral range used in the calibration model on model performance. Results: We develop multivariate calibration models for the concentrations of soluble xylo-oligosaccharides (XOS), monomeric xylose, and total solids at multiple points in a biomass conversion process which produces and then purifies XOS compounds from sugar cane bagasse. A single model using samples from multiple locations in the process stream showed acceptable performance as measured by standard statistical measures. However, compared to the single model, we show that separate models built by segregating the calibration samples according to process location show improved performance. We also show that combining an understanding of the sample spectra with simple multivariate analysis tools can result in a calibration model with a substantially smaller spectral range that provides essentially equal performance to the full-range model. Conclusions: We demonstrate that real-time monitoring of soluble xylo-oligosaccharides (XOS), monomeric xylose, and total solids concentration at multiple points in a process stream using NIR spectroscopy coupled with multivariate statistics is feasible. Segregation of sample populations by process location improves model performance. Models using a reduced spectral range containing the most relevant spectral signatures show very similar performance to the full-range model, reinforcing the importance of performing robust exploratory data analysis before beginning multivariate modeling. [ABSTRACT FROM AUTHOR]

Soil organic matter (SOM) is one of the essential components of soil and moisture to interfere with the detection. The soil moisture content by mass ratio and spectral parameters are often utilized to classify the moisture levels. But previous studies on the prediction of SOM content have focused mostly on the surface soil without covering the profile of depth range. This study aims to explore the influence of soil moisture on the inversion accuracy of the SOM profile. This study analyzed previously obtained near-infrared spectra were collected from the samples of the soil core column in the surface layer to about 150 cm underground. Each core was divided into subsamples with a height of 10 or 20 cm. The samples were gradually moistened to 6 groups of levels of soil moisture. According to the index of moisture tension, the air-dry state was defined as 1.500, 0.330, 0.100, 0.033 MPa, and the saturated state in turn. The data was normalized and transformed to the absorbance. Each set of spectral data was processed by seven spectral preprocessing. Among them, the standard normal variate transformation (SNV) was achieved the best. Meanwhile, successive projection algorithms (SPA) and competitive adaptive reweighting-successive projection algorithms (CARS-SPA) were used to screen the characteristic wavelengths. The number of characteristic wavelengths was then reduced to 6-8 at each level of soil moisture. The inversion models of SOM were constructed to combine with SNV preprocessing using full spectrum and characteristic wavelengths. The results indicated that: 1) The model accuracies of the SPA-PLSR and CARS-SPA-PLSR models were better than that of the PLSR model at six levels of moisture. 2) The SNV preprocessing was also combined to determine the coefficient of determination in prediction (R²p ) and root mean square error of the prediction set (RMSEP). Under the saturated state, R²p values of the SNV-SPA-PLSR and SNVCARS-SPA-PLSR models were 0.664 and 0.651, respectively, while the RMSEP values were 1.095 and 1.131 g/kg, respectively. In the air-dry state, R²p values of the two models were 0.799 and 0.753, respectively, and RMSEP values were 0.759 and 0.848 g/kg, respectively, indicating the better prediction of the SNV-SPA-PLSR model. The SNV-CARS-SPA-PLSR model shared the higher accuracy of prediction when the moisture tension levels were 0.033, 0.100, 0.330, and 1.500 MPa. Specifically, R²p values increased from 0.699 to 0.846, whereas, the RMSEP values decreased from 1.013 to 0.620 g/kg. 3) However, it was difficult to guarantee the same soil moisture level at the same depth in different locations of the field. The SOM calibration model was applied to the characteristic wavelengths on different datasets. The SNV-CARS-SPA-PLSR model was selected at the moisture tension of 1.500 MPa. The best performance was achieved for the organic matter in the six groups of soil moisture levels and mixed samples. The models can be expected to estimate the SOM content of the profile at various moisture levels. The findings can also provide a strong reference to improve the applicability of near-infrared spectra inversion models for the organic matter content at different levels of soil moisture. [ABSTRACT FROM AUTHOR]

Aim Methods Results Conclusion To assess the effect of ventricular decompression on cerebral oxygenation in preterm neonates with intraventricular haemorrhage (IVH) and posthemorrhagic ventricular dilatation (PHVD) using near‐infrared spectroscopy (NIRS).Fifty‐three preterm neonates born <34 weeks' gestation between 2013 and 2023 with IVH and subsequent PHVD were prospectively included. Regional cerebral oxygen saturation (rScO2) as well as fractional cerebral tissue oxygen extraction (cFTOE) were analysed 2 weeks before and after ventricular decompression.Ventricular decompression was performed at 18 ± 6 days of life. Patients with repeated lumbar punctures prior to ventricular drainage showed consistently higher rScO2 and lower cFTOE levels 2 weeks before and after intervention compared to those without. Patients who underwent direct ventricular drainage showed an immediate increase in rScO2 levels on the day of the procedure. In patients who underwent prior lumbar punctures, ventricular decompression did not yield additional acute effects on cerebral oxygenation.Patients who underwent repeated lumbar punctures preceding ventricular drainage consistently maintained higher rScO2 and lower cFTOE levels during the study period. In these patients, ventricular decompression did not further affect cerebral oxygenation, as they already demonstrated improved cerebral hemodynamics, whereas an immediate improvement was observed in those without prior lumbar punctures. [ABSTRACT FROM AUTHOR]

Background: Near-infrared spectroscopy (NIRS) provides a non-invasive, cost- effective method for assessing skeletal muscle oxidative capacity when combined with a short exercise protocol and arterial occlusions. However, the impact of different exercise protocols and reproducibility of the method in non- athletic adults have not previously been assessed. Methods: Young, non-athletic adults (YA) were invited to perform a short duration, fast frequency contraction (SF) exercise protocol and a long duration slow frequency (LS) contraction protocol, combined with NIRS measurements and arterial occlusions to assess skeletal muscle oxidative capacity. YA and older non-athletic adults (OA; >65 years old) were invited to perform the SF exercise protocol twice to assess the reproducibility of this oxidative capacity measurement. Results: We included 25 participants (14 male (56%), age range: 18--86 years) in the analyses. There was a strong positive correlation and good agreement between time constants derived following the SF and LS exercise protocols (Lin's concordance correlation coefficient: 0.69, p-value < 0.001 mean bias [LoA]: -3.2 [-31.0, 24.4] seconds. There was a strong positive correlation and good agreement between time constants derived from the SF exercise protocol in the YA & OA group (Lin's concordance correlation coefficient: 0.63, p-value < 0.001; mean bias [LoA] -6.4 [-34.0, 21.3] seconds). Conclusion: These data provide evidence to suggest that NIRS is a reliable in vivo method for the assessment of skeletal muscle oxidative capacity irrespective of exercise protocol duration or muscle contraction frequency. NIRS-measured oxidative capacity via the SF exercise protocol was reproducible in non-athletic adults with a wide range in age. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to assess the impact of multimodal monitoring on predicting the prognosis of patients with spontaneous intracerebral hemorrhage (SICH) and to examine the feasibility of using noninvasive near-infrared spectroscopy (NIRS) for monitoring clinical prognosis. Methods: Clinical data of 38 patients with SICH who underwent surgery in the Department of Neurosurgery of Shaanxi Provincial People’s Hospital from May 2022 to December 2022 were retrospectively analyzed. The patients were categorized into two groups based on the Glasgow Outcome Scale (GOS) 3  months after operation: poor outcome group (GOSI-III) and good outcome group (GOSIV and V). Multimodal monitoring included invasive intracranial pressure (ICP), brain temperature (BT), internal jugular venous oxygen saturation (SjvO2), and noninvasive NIRS. NIRS monitoring comprised the assessment of brain tissue oxygen saturation (StO2), blood volume index (BVI), and tissue hemoglobin index (THI). The prognostic differences between the two groups were compared. The predictive values were evaluated using the receiver operating characteristic (ROC) curve and the area under the curve (AUC). Results: ICP, BT, BVI, and THI in the good prognosis group were lower than those in the poor prognosis group. The SjvO2 and StO2 in the group with a good prognosis were higher than those in the group with a poor prognosis. Conclusion: The levels of ICP, BT, SjvO2, StO2, BVI, and THI reflect the changes in brain function and cerebral blood flow and significantly correlate with the prognosis of patients with SICH. NIRS monitoring has a high clinical utility in assessing the prognosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Olive tree and plant by-products can be used for enhance the nutritional composition of food due to their high content of bioactive compounds such as pentacyclic triterpenes. Here, we present a novel application of near-infrared spectroscopy for the prediction of the total or individual (maslinic acid, oleanolic acid, and uvaol) pentacyclic triterpene concentrations in a feed additive obtained from a plant mixture. This method can be applied directly to dried powder and makes extraction and high-performance liquid chromatography analysis unnecessary. It can be used at the factory level to directly determine the pentacyclic triterpene concentrations in the additive powder at the same time that the powder is produced. The nutritional composition of food for animal production can be enhanced using olive tree and plant by-products due to their high content of bioactive compounds such as pentacyclic triterpenes. Here, we present a novel application of near-infrared spectroscopy (NIRS) for the prediction of the total or individual [maslinic acid (MA), oleanolic acid (OA), and uvaol (UO)] pentacyclic triterpene concentrations in a feed additive obtained from a plant mixture. The oxygen radical absorbance capacity of these types of samples demonstrated the existence of a high antioxidant capacity. The conventional determination methods of pentacyclic triterpene concentration are costly, labor-intensive, and not practical for analyzing several lines within a limited timeframe at the factory level. The optimal regression model developed in our work demonstrated high correlation values for the calibration and validation sets, along with a high residual prediction deviation value. We used 63 samples for the development of the model. The NIRS method can be applied directly to dried powder and makes extraction and high-performance liquid chromatography (HPLC) analysis unnecessary. Our results also demonstrate that NIRS can accurately quantify pentacyclic triterpenes even at low concentrations in food additives. It can be used at the factory level to directly determine the pentacyclic triterpene concentrations in the additive powder at the same time that the powder is produced. [ABSTRACT FROM AUTHOR]

Background: Impaired cerebral autoregulation (CA) is one of several proposed mechanisms of acute brain injury in patients supported by extracorporeal membrane oxygenation (ECMO). The primary aim of this study was to determine the feasibility of continuous CA monitoring in adult ECMO patients. Our secondary aims were to describe changes in cerebral oximetry index (COx) and other metrics of CA over time and in relation to functional neurologic outcomes. Methods: This is a single-center prospective observational study. We measured COx, a surrogate measurement of cerebral blood flow measured by near-infrared spectroscopy, which is an index of CA derived from the moving correlation between mean arterial pressure (MAP) and slow waves of regional cerebral oxygen saturation. A COx value that approaches 1 indicates impaired CA. Using COx, we determined the optimal MAP (MAPOPT) and lower and upper limits of autoregulation for individual patients. These measurements were examined in relation to modified Rankin Scale (mRS) scores. Results: Fifteen patients (median age 57 years [interquartile range 47–69]) with 150 autoregulation measurements were included for analysis. Eleven were on veno-arterial ECMO (VA-ECMO), and four were on veno-venous ECMO (VV-ECMO). Mean COx was higher on postcannulation day 1 than on day 2 (0.2 vs. 0.09, p < 0.01), indicating improved CA over time. COx was higher in VA-ECMO patients than in VV-ECMO patients (0.12 vs. 0.06, p = 0.04). Median MAPOPT for the entire cohort was highly variable, ranging from 55 to 110 mm Hg. Patients with mRS scores 0–3 (good outcome) at 3 and 6 months spent less time outside MAPOPT compared with patients with mRS scores 4–6 (poor outcome) (74% vs. 82%, p = 0.01). The percentage of time when observed MAP was outside the limits of autoregulation was higher on postcannulation day 1 than on day 2 (18.2% vs. 3.3%, p < 0.01). Conclusions: In ECMO patients, it is feasible to monitor CA continuously at the bedside. CA improved over time, most significantly between postcannulation days 1 and 2. CA was more impaired in VA-ECMO patients than in VV-ECMO patients. Spending less time outside MAPOPT may be associated with achieving a good neurologic outcome. [ABSTRACT FROM AUTHOR]

We explored the impact of running in the severe intensity domain on running mechanics and muscle oxygenation in competitive runners by investigating the relationship between mechanical deviations from typical stride characteristics and muscle oxygen saturation (SmO2) in the quadriceps muscle. Sixteen youth competitive runners performed an 8‐min exhaustive running test on an outdoor track. Running mechanics were continuously monitored using inertial measurement units. Rectus femoris SmO2 and total hemoglobin (a measure of blood volume) were continuously monitored by near‐infrared spectroscopy. One‐class support vector machine (OCSVM) modeling was employed for subject‐specific analysis of the kinematic data. Statistical analysis included principal component analysis, ANOVA, and correlation analysis. Mechanical deviations from typical stride characteristics increased as the running test progressed. Specifically, the percentage of outliers in the OCSVM model rose gradually from 2.2 ± 0.8% at the start to 43.6 ± 28.2% at the end (p < 0.001, mean ± SD throughout). SmO2 dropped from 74.3 ± 8.4% at baseline to 10.1 ± 6.8% at the end (p < 0.001). A moderate negative correlation (r = −0.61, p = 0.013) was found between the average SmO2 and the percentage of outlier strides during the last 15% of the run. During high‐intensity running, alterations in running biomechanics may occur, linked to decreased quadriceps muscle oxygenation. These parameters highlight the potential of using running kinematics and muscle oxygenation in training to optimize performance and reduce injury risks. Our research contributes to understanding biomechanical and physiological responses to endurance running and emphasizes the importance of individualized monitoring. [ABSTRACT FROM AUTHOR]

Near-infrared spectroscopy (NIRS) is a noninvasive functional neuroimaging modality that can detect changes in blood oxygenation levels by tracking cortical neural activity. We recorded the resting-state brain activity of 24 individuals with schizophrenia and 90 healthy controls for 8 min using a whole-head NIRS arrangement and then used partial correlation analysis to estimate the resting-state functional connectivity (RSFC) between 17 cortical regions. We found that the RSFC between the bilateral orbitofrontal cortices (OFCs) and between the right temporal and parietal lobes was significantly higher in patients with schizophrenia than in healthy controls. The RSFC between the bilateral OFCs was positively correlated with negative symptom severity, whereas the RSFC between the right temporal and parietal lobes was positively correlated with the chlorpromazine equivalent for antipsychotics prescribed to patients with schizophrenia. This finding was consistent with that for the RSFC calculated using the anterior 52-channel signals. Our results suggest that NIRS-based RSFC measurements have potential clinical applications. [ABSTRACT FROM AUTHOR]

Autism spectrum disorder (ASD) ranges from mild to severe symptoms, with autistic traits possibly distributed throughout the population. However, the precise neurodevelopmental differences in children with autistic traits remain unknown. Fifty-three healthy volunteers (32 male and 21 female, mean [standard deviation] age: 12.9 [2.5] years) having a normal intelligence quotient and without social impairment were divided into two groups according to scores of the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS). Subjects with or without autistic traits were placed into the high-PARS (n = 14) or low-PARS (n = 39) group, respectively. Activation of the prefrontal cortex was estimated using change in hemoglobin oxygenation concentration (Δ[oxy-Hb]) on near-infrared spectroscopy (NIRS) during a verbal fluency test. Age-related changes in prefrontal cortex activation were first assessed for each group. Then, the effects of age (elementary school age or junior/senior high school age) and PARS score on Δ[oxy-Hb] in the task were analyzed by two-way analysis of variance. We observed significant positive correlations between mean Δ[oxy-Hb] and age in the prefrontal cortex region in the low-PARS group. Mean Δ[oxy-Hb] in the low-PARS group was significantly higher than in the high-PARS group. Task performance results were comparable between the groups. In PARS-determined typically developed children, prefrontal cortex activation on NIRS correlated positively with age. In healthy volunteers without ASD but harboring autistic traits, prefrontal cortex activation was markedly lower than in normal counterparts. Our results provide biological evidence that ASD may be a pervasively distributed disorder. [ABSTRACT FROM AUTHOR]

Noninvasive and real‐time optical detection of cardiac hemodynamics dysfunction during myocardial ischemia remains challenging. In this study, we developed a near‐infrared spectroscopy device to monitor rats' myocardial hemodynamics. The well‐designed system can accurately reflect the hemodynamics changes by the classic upper limb ischemia test. Systemic hypoxia by disconnecting to the ventilator and cardiac ischemia by coronary artery slipknot ligation was conducted to monitor myocardial hemodynamics. When systemic hypoxia occurred, ΔHbR and ΔtHb increased significantly, whereas ΔHbO decreased rapidly. When coronary blood flow was obstructed by slipknots, cardiothoracic ΔHbO immediately begins to decline, while ΔHbR also significantly increases. Simultaneously, SpO2 did not show any obvious changes during myocardial ischemia, while SpO2 decreased significantly during systemic hypoxia. These results demonstrated that cardiothoracic hemodynamics stemmed from myocardial ischemia. This pilot study demonstrated the practicality of noninvasive, low‐cost optical monitoring for cardiac oxygenation dysfunction in rats. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the relationship of perioperative cerebral regional oxygen saturation (rSO2) with various preoperative clinical variables and hemodynamic changes during transfemoral transcatheter aortic valve implantation (TAVI) under general anesthesia. We retrospectively analyzed cerebral rSO2 values from left-hemisphere measurements obtained using near-infrared spectroscopy (O3™ regional oximetry) at five time points: pre-induction, the start of the procedure, the start of valve deployment, time of lowest cerebral rSO2 value during valve deployment, and the end of the procedure. This study included 91 patients (60 with balloon-expandable valves and 31 with self-expandable valves). The baseline cerebral rSO2 values were correlated with B-type natriuretic peptide, hemoglobin, fractional shortening, ejection fraction, left ventricular mass index, left ventricular end-systolic diameter, STS risk of mortality, and STS morbidity or mortality. The patients who took longer to recover their systolic blood pressure to 90 mmHg after valve deployment with a balloon-expandable valve (group B) had lower cerebral rSO2 values during deployment compared to patients with faster recovery with balloon-expandable valve (group A) and with self-expandable valve (group C). Baseline cerebral rSO2 is associated with preoperative variables related to cardiac failure and function, and a significant decline during valve deployment may indicate a risk of prolonged hypotension during TAVI. [ABSTRACT FROM AUTHOR]