Spectroscopy Device Research Articles

Performance of a Handheld Near-Infrared Spectroscopy Device to Predict Pork Primal Belly Fat Iodine Value and Loin Lean Intramuscular Fat Content.

The increase in market demand and economic value of Canadian pork primal cuts has led to a need to assess advanced technologies capable of measuring quality traits. Fat and lean composition were measured using a Tellspec near-infrared (NIR) spectroscopy device to predict the pork belly fat iodine value (IV) and loin lean intramuscular fat (IMF) content in 158 pork belly primals and 419 loin chops. The calibration model revealed a 90.6% and 88.9% accuracy for the Tellspec NIR to predict saturated fatty acids (SFA) and IV, respectively, in the belly fat. The calibration model accuracy for the other belly fatty acids revealed an accuracy of 66.3-86.1%. Using the Tellspec NIR to predict loin lean IMF reported a lower accuracy for moisture (R2 = 60) and fat % (R2 = 40.4). This suggests that Tellspec NIR spectroscopy measures on the pork belly primal offers a cost-efficient, rapid, accurate, and non-invasive indicator of pork belly IV and could be used for the classification for specific markets.

The effect of pimobendan and enalapril use on blood serum trace element levels in dogs with myxomatous mitral valve disease

Background and objectiveMyxamatous mitral valve disease (MMVD) is a common acquired heart disease in dogs that can lead to progressive and long-term congestive heart failure (CHF). Pimobendan and angiotensin converting enzyme inhibitors (ACEI) are commonly used in MMVD treatment. Trace elements are essential for maintaining cardiovascular functions. Synergistic or antagonistic interactions between some trace elements and substances are widely known. In our study, it was aimed to evaluate the effects of treatment duration, age, weight and gender on serum trace element levels in dogs with MMVD by using pimobendan and enalapril as monotherapy. Material-Methods13 dogs with MMVD were treated with pimobendan (0.25–0.3 mg/kg, q12h, PO Vetmedin®) and 21 dogs with MMVD were treated with enalapril (0.25–0.5 mg/kg, q12h, PO Enapril®) for at least 30 days. The serum trace element levels (Cu, Zn, Fe, Co, Mg, Mn, Se, Cr) of all patients were measured with Inductively coupled plasma-Optical emission spectroscopy device. Relevances were evaluated related to treatment duration, age, weight and gender in each treatment group. ResultsAdjusted R2 values of the model, which included treatment, treatment duration, treatment x duration interaction, age, weight and gender as predictors, were negative except for Se. Furthermore, the model explained only 10.4% of the variation in Se. The effect of age was significant in the model of Se (β = 0.462; P = 0.028). Treatment duration also tended to be significant in the prediction of Se concentration (β = -0.364; P = 0.086). ConclusionWe consider that treatment (enalapril vs. pimobendan), treatment duration, treatment x duration interaction, weight and gender were not good predictors of trace elements. In our study, age contributed significantly only to the Se level.

Honeycomb-like aluminum antennas for surface-enhanced infrared absorption sensing

Abstract Surface-enhanced infrared absorption (SEIRA) spectroscopy is a competent method to detect trace quantity of molecules and even protein conformational flexibility by enhancing their vibrational modes. To improve the spectroscopy features, we propose a surface with honeycomb-like (HC) arrangement of aluminum equilateral triangles within a metal-insulator-metal configuration. With adjustable geometric parameters, the HC nanoantennas allow a tunable and wide spectral coverage in the IR. The reflectance measurements correlate extremely well with the numerical simulations. Being compact and insensitive to the light polarization, the HC are appealing for boosting the signal-to-noise ratio and increasing the number of hotspots as required for sensing applications. These nanoantennas are thus suitable for accurate and broadband SEIRA sensing via a spectral overlap between the large plasmonic resonances and the narrow IR vibrational modes of our analyte (vanillin). In line with our previously studied bowties nanoantennas, we demonstrate, using HC, SEIRA enhancement factors greater than 107 achieved at a tuning ratio below 1 stating the best spectral overlap. Around 104 molecules are sensed per HC tip. The investigation results are matching the best-reported SEIRA studies. These findings pave the way toward sensitive, adaptable, and miniaturized IR spectroscopy devices for vital applications like biosensing and environmental monitoring.

Validated portable device for the qualitative and quantitative electrochemical detection of MDMA ready for on-site use

Identifying and quantifying 3,4-methyl​enedioxy​methamphetamine (MDMA) on-site in suspected illicit drug samples, whether it be at recreational settings or manufacturing sites, is a major challenge for law enforcement agencies (LEAs). Various analytical techniques exist to fulfil this goal, e.g. colourimetry and portable spectroscopic techniques, each having its specific limitations (e.g. low accuracy, fluorescence, no quantification) and strengths (e.g. fast, easy to use). In this work, for the first time, an electrochemical MDMA sensor is presented to become a detection tool that can realistically be used on-site. More specifically, the use of a single buffer solution and an unmodified screen-printed electrode, along with the integration of a data analysis algorithm and mobile application permits the straightforward on-site identification and quantification of MDMA in suspicious samples. Multiple studies investigating different parameters, including pH, concentration, reproducibility, temperature and binary mixture analyses, were executed. To fully understand all the occurring redox processes, liquid chromatography coupled with high-resolution mass spectrometry analysis of partially electrolyzed MDMA samples was performed unravelling oxidation of the methylenedioxy group. Validation of the methodology was executed on 15 MDMA street samples analysed by gas chromatography coupled with mass spectrometry and compared with the performance of a commercial portable Raman and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) device. The novel methodology outperformed the spectroscopic techniques, correctly identifying all 15 street samples. Additionally, the electrochemical sensor predicted the purity of the tablets with a mean absolute error of 2.3%. Overall, this new, electrochemical detection strategy provides LEAs the rapid, low-cost, on-site detection and quantification of MDMA in suspicious samples, without requiring specialized training.

The Effect of Upright Lower Body Negative Pressure on Muscle Activity and Hemodynamics during Exercise

Purpose: The aim of the study was to evaluate the changes that occur in parameters relating to muscle work and muscle hemodynamicsunder the influence of upright Lower Body Negative Pressure (LBNP) application during walking. Methods: 18 young females were included in this study. All 18 subjects participated in 2 trials of a 12-minute walking exercise on a treadmill equipped with a LBNP chamber, on a constant speed of 5 km/h. The first trial was executed under the application of a LBNP program (3 stages of -15, -25 and -30 mbar), while the second trial was similar, but without the activation of the negative pressure chamber. During both trials, the Vastus Lateralis (VL) muscle hemodynamic conditions were monitored continuously with a Functional Near-Infrared Spectroscopy (fNIRS) device and parallelly, VL activation was monitored via a Surface Electromyography (sEMG). Heart Rate (HR) values were recorded in the beginning and during the10th min of each trial, after which, the difference between the 2 values was calculated. Immediately after the conclusion of each trial, participants were asked to provide a score for perceived exertion using Borg CR-10 scale (10 for maximum exertion). Results: During the LBNP trial, Total Hemoglobin (tHb) and OxyHemoglobin (O2 Hb) concentrations in the Vastus Lateralis (VL), was significantly lower compared to the control (p=0.007, p=0.001), but with a significant increase rate in deoxy-hemoglobin (HHb) (p= 0.001). Tissue Saturation Index (TSI%) showed no significant alteration between trials (p= 0.668). All calculated parameters relating to work output showed a significant difference in the LBNP trial compared to control. HR was increased (p= 0.001), there were an increase in MPF and RMS amplitude in the VL (p=0.006, p < 0.001, respectively) and subjects reported higher rate of perceived exertion (p=0.001). Conclusions: The application of LBNP showed elevated work characteristics, mainly on the work output and less local muscle hemodynamics. This could be a time efficient training tool for stressing the musculoskeletal system, faster improve body composition and potentially enhancing cardio respiratory fitness.

Performance of a new portable near-infrared spectroscopy device for detection of traumatic intracranial hematoma

IntroductionWe report results of a newly developed portable near-infrared spectroscopy (NIRS) based point-of-care device CEREBO® to detect traumatic intracranial hematoma (TICH). Materials and methodsPatients with alleged history of head injury visiting emergency room were enrolled. They were examined consecutively for the presence of TICH using CEREBO® and computed tomography (CT) scans. ResultsA total of 158 participants and 944 lobes were scanned, and 18% of lobes were found to have TICH on imaging with computed tomography of the head. 33.9% of the lobes could not be scanned due to scalp lacerations. The mean depth of hematoma was 0.8 (SD 0.5) cm and the mean volume of the hematoma was 7.8 (11.3) cc. The overall sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of CEREBO® to classify subjects as hemorrhagic or non-hemorrhagic were 96% (CI 90 - 99%), 85% (CI 73 - 93%), 92% (CI 86 - 96%), 91% (CI 84 - 96%) and 93% (CI 82 - 98%) whereas to classify the lobes as hemorrhagic and non-hemorrhagic, the sensitivity, specificity, accuracy, PPV and NPV were 93% (CI 88 - 96%), 90% (CI 87 - 92%), 90% (CI 88 - 92%), 66% (CI 61 - 73%), and 98% (CI 97 - 99%) respectively. The sensitivity was highest at 100% (CI 92 - 100%) for the detection of extradural and subdural hematoma. The sensitivity for detecting intracranial hematoma including epidural, subdural, intracerebral and subarachnoid hematomas, of more than 2 cc was 97% (CI 93 - 99%) and the NPV was 100% (CI 99 - 100%). The sensitivity dropped for hematomas less than 2cc in volume to 84% (CI 71 - 92%) and the NPV was 99% (CI 98 - 99%). The sensitivity to detect bilateral hematomas was 94% (CI 74 - 99%). ConclusionThe performance of currently tested NIRS device for detection of TICH was good and can be considered for triaging a patient requiring a CT scan of the head after injury. The NIRS device can efficiently detect traumatic unilateral hematomas as well as those bilateral hematomas where the volumetric difference is greater than 2cc.

Abstract P1-05-16: Bioimpedance Spectroscopy Monitoring Reduces Long-term Clinical Lymphedema Risk

Abstract Background: A prospective surveillance model (PSM) of care can reduce the risk of breast cancer related lymphedema (BCRL). Bioimpedance spectroscopy (BIS) devices can identify sub-clinical BCRL (sBCRL). A recent randomized controlled trial (RCT) demonstrated the benefit of a PSM model of care using BIS over tape measure (TM) but it did not look at the long-term risk following intervention. This work reports the actuarial risk of clinical lymphedema for those who have triggered an intervention for sBCRL by either BIS or TM. Materials and Methods: 879 women with breast cancer were randomized to lymphedema screening with either BIS (n=442) or TM (n=437). Following consent, patients underwent baseline pre-surgical measurements with BIS (L-Dex U400, ImpediMed) and volume (circumference) measurements (Gulick II tape) and randomized after surgery. Both the TM and BIS arms underwent planned post-operative assessments at 3, 6, 12, 18, 24, 30, and 36 months as well at the end of any intervention. Patients with a BIS change from baseline of ≥ 6.5 L-Dex units or TM volume change ≥ 5 and < 10% above pre-surgical baselines "triggered" for sBCRL form the basis of this study. Triggered patients underwent 4-weeks of wearing a class two (23–32 mmHg) compression sleeve and gauntlet for 12 hours per day. TM volume change ≥ 10% was considered clinical BCRL (cBCRL) for all patients who triggered by either BIS or TM. The cumulative incidence of cBCRL was calculated via the Kaplan-Meier method and compared by the Log-rank test. Results: 209 (23.8%) women triggered an intervention and completed treatment for sBCRL (BIS: 89 (20.1%), TM: 120 (27.5%)). The median follow up for the women who triggered was 32.2 months (IQR 17.0 – 33.9) with 30 women (14.4%) women developing cBCRL (BIS: 7 (7.9%), TM: 23 (19.2%)). There was a significant difference in risk between the groups over the follow up interval (log rank test p = 0.021) with the cumulative risk in the BIS group being lower compared to the TM group (Hazard Ratio = 0.38, 95%CI 0.19 – 0.79). The 2- year actuarial risk of cBCRL for triggered patients undergoing lymphedema screening by BIS was 5.0% versus 15.7% for TM screening (p = 0.021, HR = 0.30). The corresponding 3-year rates of cBCRL were 10.3% and 21.2%, (p = 0.031, HR = 0.40) respectively. Conclusions: BIS monitoring for sBCRL with subsequent intervention provides significantly lower risks of cBCRL. The lower triggering rates with BIS highlight its better discrimination of true sBCRL compared to TM and support its use for post-treatment surveillance to detect sBCRL and initiate early intervention. These data suggest that monitoring for sBCRL with BIS and subsequent intervention does not just delay the inevitable progression to cBCRL, but rather prevents it over the duration of the study. Citation Format: John Boyages, Frank Vicini, Chirag Shah. Bioimpedance Spectroscopy Monitoring Reduces Long-term Clinical Lymphedema Risk [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-05-16.

Smartphone-assisted lab-in-a-tube device using gold nanocluster-based aptasensor for detection of MUC1-overexpressed tumor cells

Developing smartphone technology for point-of-care diagnosis is one of the current favorable trends in the field of biosensors. In fact, using smartphones can provide better accessibility and facility for rapid diagnosis of diseases. On the other hand, the detection of circulating tumor cells (CTCs) is one of the recent methods for the early diagnosis of cancer. Here, a new smartphone-assisted lab-in-a-tube device is introduced for the detection of Mucin 1 (MUC1) overexpressed tumor-derived cell lines using gold nanoclusters (GNCs)-based aptasensor. Accordingly, commercial polyurethane (PU) foam was first coated with graphene oxide (GO) to increase its surface area (8.45-fold), and improve its wettability. The surface of the resulting three-dimensional PU-GO (3DPU-GO) platform was then modified by MUC1 aptamer-GNCs to provide the required sensitivity and specificity through a turn “on/off” detection system. The proposed biosensor was first optimized with a spectrophotometer method. Afterward, findings were evaluated based on the red color intensity of the lab-in-a-tube system; and indicated the high ability of the biosensor for detection of MUC1-overexpressed tumor cell lines in the range of 250–20,000 cells mL−1 with a limit of detection of 221 cells mL−1. In addition, the developed biosensor showed a decent selectivity against positive-control cell lines (MCF-7, and HT-29) in comparison to negative-control cell lines (HEK293, and L929). Notably, the results represented good accordance with reference methods including spectroscopy devices. Ultimately, the results of this work bring a new perspective to the field of point-of-care detection and can be considered in future biosensors.

Open-sourced Raman spectroscopy data processing package implementing a baseline removal algorithm validated from multiple datasets acquired in human tissue and biofluids.

Standardized data processing approaches are required in the field of bio-Raman spectroscopy to ensure information associated with spectral data acquired by different research groups, and with different systems, can be compared on an equal footing. An open-sourced data processing software package was developed, implementing algorithms associated with all steps required to isolate the inelastic scattering component from signals acquired using Raman spectroscopy devices. The package includes a novel morphological baseline removal technique (BubbleFill) that provides increased adaptability to complex baseline shapes compared to current gold standard techniques. Also incorporated in the package is a versatile tool simulating spectroscopic data with varying levels of Raman signal-to-background ratios, baselines with different morphologies, and varying levels of stochastic noise. Application of the BubbleFill technique to simulated data demonstrated superior baseline removal performance compared to standard algorithms, including iModPoly and MorphBR. The data processing workflow of the open-sourced package was validated in four independent in-human datasets, demonstrating it leads to inter-systems data compatibility. A new open-sourced spectroscopic data pre-processing package was validated on simulated and real-world in-human data and is now available to researchers and clinicians for the development of new clinical applications using Raman spectroscopy.

Open-Path Atmospheric Transmission of Diode-Pumped Alkali Lasers in Maritime and Desert Environments.

A tunable diode laser absorption spectroscopy (TDLAS) device has been developed to study long-path atmospheric transmission near diode pumped alkali laser (DPAL) emission wavelengths. By employing a single aperture and retro reflector in a mono-static configuration, the noise associated with atmospheric and platform jitter were reduced by a factor of ∼30 and the open-air path length was extended to 4.4 km and over a very broad spectral range, up to 120 cm-1. Water vapor absorption lines near the rubidium (Rb) and cesium (Cs) variants of the DPAL near 795 and 894 nm, oxygen lines near the potassium (K) DPAL near 770 nm, and water vapor absorption in the vicinity of the neodymium-doped yttrium aluminum garnet (Nd:YAG) laser 1.064 μm and chemical oxygen iodine laser (COIL) 1.3 μm lines were studied. The detection limit for path absorbance increases from ΔA = 0.0017 at 100 m path length to 0.085 for the 4.4 km path. Comparison with meteorological instruments for maritime and desert environments yields agreement for the 2.032 km path to within 1.5% for temperature, 4.5% for pressure, and 5.1% for concentration, while agreements for the 4.4 km path are within 1.4% for temperature, 7.7% for pressure, and 23.5% for concentration. An intra cavity output spectroscopy (ICOS) device was also used as a spectral reference to verify location of atmospheric lines. Implications of TDLAS collection system design on signal-to-noise (S/N) are discussed as well as the effect of path turbulence on baseline noise and inform the selection of the DPAL variant least affected by molecular absorption.

Validity of total body water measured by multi-frequency bioelectrical impedance devices in a multi-ethnic sample

Total body water (TBW) is the largest component of fat free mass and therefore is commonly used in multi-compartment body composition models and as a stand-alone method to assess body composition. Previous literature has not validated bioelectrical impedance spectroscopy device estimates of TBW in racial and ethnic minority populations; previous studies have focused on bioelectrical impedance analysis devices that rely on proprietary algorithms and participant characteristics for accuracy. The purpose of this study was to assess the validity of two bioelectrical impedance spectroscopy devices for measures of TBW compared to a deuterium dilution criterion in a multi-ethnic sample. 109 individuals (55% female, Age: 26.6±6.9yrs, BMI: 25.3±4.0kg/m2) identifying as Asian, African American/Black, Caucasian/White, Hispanic, and Multi-racial were enrolled. After a 12h fast, participants provided a saliva sample for the criterion baseline TBW measure and completed two bioelectrical impedance device (BIS, IB) measurements of TBW. Participants then ingested deuterium oxide (D2O). After an equilibration period, participants provided a second saliva sample for analysis of TBW. For the total multi-ethnic sample, BIS estimates demonstrated good to fairly good agreement (Total error [TE]=2.56L, R2=0.951) and IB estimates were excellent to very good (TE=1.95L, R2=0.975). Validity results did not vary meaningfully between race and ethnicity. The results suggest the BIS and IB devices evaluated can produce valid TBW estimates compared to D2O in a multi-ethnic sample. TBW estimates from the IB may have better agreement with D2O compared to the BIS when using the default settings.

2D Hierarchical NiMoO4 Nanosheets/Activated Carbon Nanocomposites for High Performance Supercapacitors: The Effect of Nickel to Molybdenum Ratios.

Supercapacitors have the potential to be used in a variety of fields, including electric vehicles, and a lot of research is focused on unique electrode materials to enhance capacitance and stability. Herein, we prepared nickel molybdate/activated carbon (AC) nanocomposites using a facile impregnation method that preserved the carbon surface area. In order to study how the nickel-to-molybdenum ratio affects the efficiency of the electrode, different ratios between Ni-Mo were prepared and tested as supercapacitor electrodes, namely in the following ratios: 1:1, 1:2, 1:3, 1:4, and 1:5. X-ray diffraction, X-ray photoelectron spectroscopy, FESEM, HRTEM, and BET devices were extensively used to analyze the structure of the nanocomposites. The structure of the prepared nickel molybdates was discovered to be 2D hierarchical nanosheets, which functionalized the carbon surface. Among all of the electrodes, the best molar ratio between Ni-Mo was found to be 1:3 NiMo3/AC reaching (541 F·g-1) of specific capacitance at a current density of 1 A·g-1, and 67 W·h·Kg-1 of energy density at a power density of 487 W·Kg-1. Furthermore, after 4000 repetitive cycles at a large current density of 4 A·g-1, an amazing capacitance stability of 97.7% was maintained. This remarkable electrochemical activity for NiMo3/AC could be credited towards its 2D hierarchical structure, which has a huge surface area of 1703 m2·g-1, high pore volume of 0.925 cm3·g-1, and large particle size distribution.

Influence of high-level mathematical thinking on L2 phonological processing of Chinese EFL learners: Evidence from an fNIRS study

The contribution of language to the development of mathematical skills has been studied for several decades. However, how mathematical thinking influences language learning, especially second language (L2) learning, remains unknown. To approach this question, this study employed a control/experimental design to reveal the impacts of high-level mathematical thinking used in geometrical problems on the phonological processing of adult Chinese learners of English as a foreign language using a functional near-infrared spectroscopy (fNIRS) device. The results showed that high-level mathematical thinking in processing geometrical problems would not produce instant behavioural impacts on learners’ L2 learning, although it inhibited learners’ brain function activation and network functional connectivity (FC) for language processing. Nevertheless, it is presumed that high-level mathematical thinking may generate ‘cognitive residue’ in phonological processing of L2 as only learners with good phonics ability could reluctantly activate the brain regions necessary for English phonological decoding.

High spatial and temporal resolution cerebrovascular reactivity for humans and large mammals: A technological description of integrated fNIRS and niABP mapping system.

Introduction: The process of cerebral vessels maintaining cerebral blood flow (CBF) fairly constant over a wide range of arterial blood pressure is referred to as cerebral autoregulation (CA). Cerebrovascular reactivity is the mechanism behind this process, which maintains CBF through constriction and dilation of cerebral vessels. Traditionally CA has been assessed statistically, limited by large, immobile, and costly neuroimaging platforms. However, with recent technology advancement, dynamic autoregulation assessment is able to provide more detailed information on the evolution of CA over long periods of time with continuous assessment. Yet, to date, such continuous assessments have been hampered by low temporal and spatial resolution systems, that are typically reliant on invasive point estimations of pulsatile CBF or cerebral blood volume using commercially available technology. Methods: Using a combination of multi-channel functional near-infrared spectroscopy and non-invasive arterial blood pressure devices, we were able to create a system that visualizes CA metrics by converting them to heat maps drawn on a template of human brain. Results: The custom Python heat map module works in "offline" mode to visually portray the CA index per channel with the use of colourmap. The module was tested on two different mapping grids, 8 channel and 24 channel, using data from two separate recordings and the Python heat map module was able read the CA indices file and represent the data visually at a preselected rate of 10 s. Conclusion: The generation of the heat maps are entirely non-invasive, with high temporal and spatial resolution by leveraging the recent advances in NIRS technology along with niABP. The CA mapping system is in its initial stage and development plans are ready to transform it from "offline" to real-time heat map generation.

Chemometric Approach Based on Explainable AI for Rapid Assessment of Macronutrients in Different Organic Fertilizers Using Fusion Spectra

Wet chemical methods are usually employed in the analysis of macronutrients such as Potassium (K) and Phosphorus (P) and followed by traditional sensor techniques, including inductively coupled plasma optical emission spectrometry (ICP OES), flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectrometry (GF AAS), and inductively coupled plasma mass spectrometry (ICP-MS). Although these procedures have been established for many years, they are costly, time-consuming, and challenging to follow. This study studied the combination of laser-induced breakdown spectroscopy (LIBS) and visible and near-infrared spectroscopy (Vis-NIR) for the quick detection of PK in different varieties of organic fertilizers. Explainable AI (XAI) through Shapley additive explanation values computation (Shap values) was used to extract the valuable features of both sensors. The characteristic variables from different spectroscopic devices were combined to form the spectra fusion. Then, PK was determined using Support Vector Regression (SVR), Partial Least Squares Regression (PLSR), and Extremely Randomized Trees (Extratrees) models. The computation of the coefficient of determination (R2), root mean squared error (RMSE), and residual prediction deviation (RPD) showed that FUSION was more efficient in detecting P (R2p = 0.9946, RMSEp = 0.0649% and RPD = 13.26) and K (R2p = 0.9976, RMSEp = 0.0508% and RPD = 20.28) than single-sensor detection. The outcomes indicated that the features extracted by XAI and the data fusion of LIBS and Vis-NIR could improve the prediction of PK in different varieties of organic fertilizers.

The Behavior of Muscle Oxygen Saturation, Oxy and Deoxy Hemoglobin during a Fatigue Test in Fibromyalgia.

Previous studies have reported that people with fibromyalgia (FM) could suffer from mitochondrial dysfunction. However, the consumption of muscle oxygen during physical exercise has been poorly studied. Therefore, this study aimed to explore the response of muscle oxygen during a fatigue protocol in people with FM and healthy controls (HC). In addition, the peak torque and the total work were assessed. A total of 31 participants (eighteen were people with fibromyalgia and thirteen were healthy controls) were enrolled in this cross-sectional study. All the participants underwent a fatigue protocol consisting of 20 repetitions at 180°·s-1 of quadriceps flexions and extensions using a Biodex System 3. The muscle oxygen saturation (SmO2), total hemoglobin (THb), deoxygenated hemoglobin (HHb) and oxygenated hemoglobin (O2Hb) values were measured using a portable near-infrared spectroscopy (NIRS) device. Significant differences between people with FM and healthy controls were found at baseline: SmO2 (FM: 56.03 ± 21.36; HC: 77.41 ± 10.82; p = 0.036), O2Hb (FM: 6.69 ± 2.59; HC: 9.37 ± 1.31; p = 0.030) and HHb (FM: 5.20 ± 2.51; HC: 2.73 ± 1.32; p = 0.039); during the fatigue protocol: SmO2 (FM: 48.54 ± 19.96; HC: 58.87 ± 19.72; p = 0.038), O2Hb (FM: 5.70 ± 2.34; HC: 7.06 ± 2.09; p = 0.027) and HHb (FM: 5.69 ± 2.65; HC: 4.81 ± 2.39; p = 0.048); and in the recovery at three min and six min for SmO2, O2Hb and HHb (p < 0.005). Furthermore, healthy control values of SmO2, O2Hb and HHb have been significantly altered by the fatigue protocol (p < 0.005). In contrast, people with FM did not show any significant alteration in these values. Moreover, significant differences were found in the peak torque at extension (FM: 62.48 ± 24.45; HC: 88.31 ± 23.51; p = 0.033) and flexion (FM: 24.16 ± 11.58; HC: 42.05 ± 9.85; p = 0.010), and the total work performed at leg extension (FM: 1039.78 ± 434.51; HC: 1535.61 ± 474.22; p = 0.007) and flexion (FM: 423.79 ± 239.89; HC: 797.16 ± 194.37; p = 0.005).

Importance of Bio-electrical Impedance for Measurement of Body Fluid Status in Chronic Kidney Disease Patients on Maintenance Haemodialysis: A Narrative Review

Assessing the precise body water status in patients with renal disorders is crucial for their health. It has been reported that chronic fluid overload is present even in the early stages of renal insufficiency. If volume overload in a patient with chronic renal failure is not controlled, serious problems such as pulmonary oedema, cardiac remodelling, and diastolic heart failure can develop. Bioelectrical Impedance Analysis (BIA) has emerged as one of the most useful tools, although randomised clinical studies are lacking to support its universal use. Early management of hydration may improve clinical outcomes, as it allows for personalised dialysis prescriptions and nutritional support. BIA practice is utilised as non invasive health monitoring for Body Composition (BC). BIA is a practical and inexpensive method. Moreover, BIA parameters estimated for disease prognosis analysis have been found to be reasonably predictable for both patient status and healthcare. Additionally, BIA is a simple, accurate, portable, quick, easy, and low-cost method. In patients with End-stage Renal Disease (ESRD) undergoing maintenance Haemodialysis (HD) treatment, excessive fluid volume is considered a risk factor for death. Furthermore, fluid elimination to achieve Dry Weight (DW) is a crucial component of HD treatment for ESRD patients. DW is an important concept related to patients undergoing HD. Conventional methods seem to be time-consuming and operator-dependent. BIA is a new and simple method that has been reported to accurately estimate DW. Estimating the dry weight of HD patients is a challenging task. Many tools are available, but not every HD centre has access to them. Several strategies have been used to develop a more standardised method of assessing dry weight in HD patients. The Bio-impedance Spectroscopy (BIS) device has been validated against gold standard methods of volume assessment. Body composition monitoring appears to be a helpful diagnostic tool that reasonably complements existing clinical methods in assessing the DW of HD patients. BIS identifies Fluid Overload (FO) as a virtual "Over Hydration (OH)" compartment, which is calculated from the difference between the measured extracellular volume and the predicted values based on a fixed hydration of lean and adipose tissue mass.

Dielectric studies of BaxPb1−x(NO3)2 single crystals for optoelectronic applications

The study described above involves growing a series of mixed crystals of BaxPb1−x(NO3)2 with different initial Ba+2/Pb+2 ratios (x = 0 to 1), and analyzing their behavior in an applied electric field by measuring the dielectric constant (ε) and dielectric loss (tan δ) at different frequencies and temperatures. The results of the study show that the behavior of the mixed crystals varies depending on their composition, with both positive and negative deviations from linearity observed in the dielectric constant and dielectric loss. This non-linear behavior may have implications for the use of these nitrate crystals in various applications, including Stimulated Raman Scattering, lasers, and medical, spectroscopy, defense, and research devices. Overall, this study provides important insights into the behavior of BaxPb1−x(NO3)2 mixed crystals under an applied electric field, and highlights their potential applications in various fields of science and technology.

Recent Advances and Design Strategies Towards Wearable Near-Infrared Spectroscopy

With a growing focus on properties of softness, miniaturization, and intelligence, extensive research has been focusing on constructing wearable electronic devices facilitating comfort, wearable health monitoring and diagnosis. Among recent progress in the development of wearable bioelectronics, wearable near-infrared spectroscopy (NIRS) devices demonstrate wide implementation possibilities in multiple health monitoring scenarios. Throughout the years, multiple design strategies have assisted in developing wearable NIRS devices with high wearing comfortability and miniaturized size. This review summarizes the principle of NIRS technology, recent advances in design strategies towards soft, wearable, miniaturized NIRS devices, and the future potential development directions. Based on the discussion of different design strategies, including modular device design, flexible hybrid electronics, and materials innovation, we also pinpoint some development directions for wearable NIRS. The reviewed and proposed research efforts may enhance the applicability and capability of NIRS as an important technology for digital health.

Clinical Utility of an AI-powered, Handheld Elastic Scattering Spectroscopy Device on the Diagnosis and Management of Skin Cancer by Primary Care Physicians.

Patients with lesions suspicious for skin cancer often present to primary care physicians (PCPs), who may have limited training in skin cancer diagnosis. To measure the impact of an adjunctive handheld device for PCPs that employs elastic scattering spectroscopy (ESS) on the diagnosis and management of skin cancer. Fifty-seven PCPs evaluated 50 clinical images of skin lesions (25 malignant and 25 benign), first without and then with knowledge of the handheld ESS device output, and in each case indicated if a lesion was likely to be benign or malignant. The diagnostic sensitivity of the PCPs with and without the use of the ESS device was 88% (95% CI, 84%-92%) and 67% (95% CI, 62%-72%), respectively (P < .0001). In contrast, no significant difference was observed in the diagnostic specificity. The management sensitivity of the physicians with and without the use of the ESS device was 94% (95% CI, 91%-96%) and 81% (95% CI, 77%-85%), respectively (P = .0009). Similarly, no significant difference was observed in the management specificity. The use of the ESS device may have the potential to help improve skin cancer diagnosis and confidence in management decision-making in a primary care setting.