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Journal of Biomedical Optics Sep 2023The shortwave infrared (SWIR, to 2000 nm) holds promise for label-free measurements of water and lipid content in thick tissue, owed to the chromophore-specific...
SIGNIFICANCE
The shortwave infrared (SWIR, to 2000 nm) holds promise for label-free measurements of water and lipid content in thick tissue, owed to the chromophore-specific absorption features and low scattering in this range. water and lipid estimations have potential applications including the monitoring of hydration, volume status, edema, body composition, weight loss, and cancer. To the best of our knowledge, there are currently no point-of-care or wearable devices available that exploit the SWIR wavelength range, limiting clinical and at-home translation of this technology.
AIM
To design and fabricate a diffuse optical wearable SWIR probe for water and lipid quantification in tissue.
APPROACH
Simulations were first performed to confirm the theoretical advantage of SWIR wavelengths over near infrared (NIR). The probe was then fabricated, consisting of light emitting diodes at three wavelengths (980, 1200, 1300 nm) and four source-detector (S-D) separations (7, 10, 13, 16 mm). validation was then performed on emulsion phantoms containing varying concentrations of water, lipid, and deuterium oxide (). A deep neural network was developed as the inverse model for quantity estimation.
RESULTS
Simulations indicated that SWIR wavelengths could reduce theoretical water and lipid extraction errors from to when compared to NIR wavelengths. The SWIR probe had good signal-to-noise ratio ( up to 10 mm S-D) and low drift ( up to 10 mm S-D). Quantification error in emulsion phantoms was for water and for lipid. Water estimation during a dilution experiment had an error of .
CONCLUSIONS
This diffuse optical SWIR probe was able to quantify water and lipid contents with good accuracy, opening the door to human investigations.
Topics: Humans; Emulsions; Deep Learning; Water; Wearable Electronic Devices; Lipids
PubMed: 37313427
DOI: 10.1117/1.JBO.28.9.094808 -
Advanced Science (Weinheim,... Aug 2023Gas-solid reactions are important for many redox processes that underpin the energy and sustainability transition. The specific case of hydrogen-based iron oxide...
Gas-solid reactions are important for many redox processes that underpin the energy and sustainability transition. The specific case of hydrogen-based iron oxide reduction is the foundation to render the global steel industry fossil-free, an essential target as iron production is the largest single industrial emitter of carbon dioxide. This perception of gas-solid reactions has not only been limited by the availability of state-of-the-art techniques which can delve into the structure and chemistry of reacted solids, but one continues to miss an important reaction partner that defines the thermodynamics and kinetics of gas phase reactions: the gas molecules. In this investigation, cryogenic-atom probe tomography is used to study the quasi in situ evolution of iron oxide in the solid and gas phases of the direct reduction of iron oxide by deuterium gas at 700°C. So far several unknown atomic-scale characteristics are observed, including, D accumulation at the reaction interface; formation of a core (wüstite)-shell (iron) structure; inbound diffusion of D through the iron layer and partitioning of D among phases and defects; outbound diffusion of oxygen through the wüstite and/or through the iron to the next free available inner/outer surface; and the internal formation of heavy nano-water droplets at nano-pores.
PubMed: 37290039
DOI: 10.1002/advs.202300626 -
Food Chemistry: X Jun 2023DO-assisted moisture analysis of edible oils was investigated. The acetonitrile extract of the oil samples was split into two parts. The spectrum of one part was taken...
DO-assisted moisture analysis of edible oils was investigated. The acetonitrile extract of the oil samples was split into two parts. The spectrum of one part was taken as is, another was recorded after addition of excess DO. Changes in spectral absorption of the H-O-H bending band (1600-1660 cm) was used to calculate moisture in oil samples. To effectively depleting absorption of water in the acetonitrile extract, a 30-fold excess of DO is required. The typical OH-containing constituents in oil did not show significant interference on the H/D exchange. Validation experiments by using five oils with five levels of moisture spiked (50-1000 μg/g) suggested that the prediction tracked the spiked amounts well. The results of variance analysis indicate that there is no difference in terms of analytical methods and oil types used ( < 0.001). The DO method developed is generally applicable to the accurate analysis of moisture at trace levels (<100 μg/g) in edible oils.
PubMed: 37179978
DOI: 10.1016/j.fochx.2023.100679 -
European Journal of Pharmaceutical... Aug 2023The discovery of cephalosporin and demonstration of its improved stability in aqueous solution, as well as enhanced in vitro activity against penicillin-resistant...
The discovery of cephalosporin and demonstration of its improved stability in aqueous solution, as well as enhanced in vitro activity against penicillin-resistant organisms, were major breakthroughs in the development of β-lactam antibiotics. Although cephalosporins are more stable with respect to hydrolytic degradation than penicillins, they still experience a variety of chemical transformations. The present study offers an insight into the rates and mechanisms of ceftriaxone degradation at the therapeutic concentration in water, a mixture of water and deuterium oxide, and deuterium oxide itself at the neutral pH. Specific ceftriaxone degradation products were observed in aged samples (including a previously unreported dimer-type species), and by comparing the degradation rates in HO and DO, the observation of a kinetic isotope effect provided some valuable insight as to the nature of the initial ceftriaxone degradation. The effect of protium to deuterium isotope change on the degradation kinetics of ceftriaxone was evaluated using the method of initial rates based on HPLC analysis as well as by quantitative H NMR spectroscopy. Moreover, computational analysis was utilized to get a molecular insight into chemical processes governing the ceftriaxone degradation and to rationalize the stabilizing effect of replacing HO with DO.
Topics: Deuterium Oxide; Deuterium; Ceftriaxone; Kinetics; Water; Cephalosporins
PubMed: 37160178
DOI: 10.1016/j.ejps.2023.106461 -
GeroScience Aug 2023Right heart failure (RHF) is a common and deadly disease in aged populations. Extra-cardiac outcomes of RHF such as skeletal muscle atrophy contribute to morbidity and...
Right heart failure (RHF) is a common and deadly disease in aged populations. Extra-cardiac outcomes of RHF such as skeletal muscle atrophy contribute to morbidity and mortality. Despite the significance of maintaining right ventricular (RV) and muscle function, the mechanisms of RHF and muscle atrophy are unclear. Metformin (MET) improves cardiac and muscle function through the regulation of metabolism and the cellular stress response. However, whether MET is a viable therapeutic for RHF and muscle atrophy is not yet known. We used deuterium oxide labeling to measure individual protein turnover in the RV as well as subcellular skeletal muscle proteostasis in aged male mice subjected to 4 weeks of hypobaric hypoxia (HH)-induced RHF. Mice exposed to HH had elevated RV mass and impaired RV systolic function, neither of which was prevented by MET. HH resulted in a higher content of glycolytic, cardiac, and antioxidant proteins in the RV, most of which were inhibited by MET. The synthesis of these key RV proteins was generally unchanged by MET, suggesting MET accelerated protein breakdown. HH resulted in a loss of skeletal muscle mass due to inhibited protein synthesis alongside myofibrillar protein breakdown. MET did not impact HH-induced muscle protein turnover and did not prevent muscle wasting. Together, we show tissue-dependent responses to HH-induced RHF where the RV undergoes hypertrophic remodeling with higher expression of metabolic and stress response proteins. Skeletal muscle undergoes loss of protein mass and atrophy, primarily due to myofibrillar protein breakdown. MET did not prevent HH-induced RV dysfunction or muscle wasting, suggesting that the identification of other therapies to attenuate RHF and concomitant muscle atrophy is warranted.
Topics: Male; Mice; Animals; Heart Failure; Myocardium; Heart Ventricles; Muscular Atrophy
PubMed: 37118350
DOI: 10.1007/s11357-023-00777-7 -
The British Journal of Nutrition Oct 2023This study aimed to assess the validity of mid-arm circumference (MAC), also known as mid-upper arm circumference (MUAC), for classification of high body fatness in...
This study aimed to assess the validity of mid-arm circumference (MAC), also known as mid-upper arm circumference (MUAC), for classification of high body fatness in Namibian adolescent girls and women and to test whether classification accuracy of MUAC was higher than the traditional simple proxy for high fatness, the BMI. In 206 adolescent girls aged 13-19 years and 207 adult women aged 20-40 years, we defined obesity conventionally (BMI-for-age Z score ≥ 2·00, adolescents; adults BMI ≥ 30·0 kg/m) and also defined obesity using published MAC cut-off values. H oxide dilution was used to measure total body water (TBW) to define high body fat percentage (≥ 30 % in the adolescents, ≥ 38 % in the adults), and we compared the ability of BMI and MAC to classify high body fatness correctly using sensitivity, specificity and predictive values. In the adolescents, obesity prevalence was 9·2 % (19/206) using BMI-for-age and 63·2 % (131/206) using TBW; sensitivity of BMI-for-age was 14·5 % (95 % CI 9·1, 22·0 %) but was improved significantly using MAC of 22·6 cm (sensitivity 96·9 %; 95 % CI 92·1 %, 99·3 %). In the adults, obesity prevalence was 30·4 % (63/207) using BMI and 57·0 % (118/207) using TBW, and sensitivity of BMI was 52·5 % (95 % CI 43·6, 62·2 %), but using a MAC of 30·6 cm sensitivity was 72·8 % (95 % CI 66·4, 82·6 %). Surveillance of obesity in African adolescent girls and adult women is likely to be improved substantially by use of MAC as an alternative to the BMI-for-age and BMI.
Topics: Humans; Adult; Adolescent; Female; Body Mass Index; Sensitivity and Specificity; Cross-Sectional Studies; Obesity; Adipose Tissue; Anthropometry
PubMed: 36890660
DOI: 10.1017/S0007114523000387 -
The British Journal of Nutrition Jul 2023Growth patterns of breastfed infants show substantial inter-individual differences, partly influenced by breast milk (BM) nutritional composition. However, BM...
Associations between breast milk intake volume, macronutrient intake and infant growth in a longitudinal birth cohort: the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF).
Growth patterns of breastfed infants show substantial inter-individual differences, partly influenced by breast milk (BM) nutritional composition. However, BM nutritional composition does not accurately indicate BM nutrient intakes. This study aimed to examine the associations between both BM intake volumes and macronutrient intakes with infant growth. Mother-infant dyads ( 94) were recruited into the Cambridge Baby Growth and Breastfeeding Study (CBGS-BF) from a single maternity hospital at birth; all infants received exclusive breast-feeding (EBF) for at least 6 weeks. Infant weight, length and skinfolds thicknesses (adiposity) were repeatedly measured from birth to 12 months. Post-feed BM samples were collected at 6 weeks to measure TAG (fat), lactose (carbohydrate) (both by H-NMR) and protein concentrations (Dumas method). BM intake volume was estimated from seventy infants between 4 and 6 weeks using dose-to-the-mother deuterium oxide (HO) turnover. In the full cohort and among sixty infants who received EBF for 3+ months, higher BM intake at 6 weeks was associated with initial faster growth between 0 and 6 weeks ( + se 3·58 + 0·47 for weight and 4·53 + 0·6 for adiposity gains, both < 0·0001) but subsequent slower growth between 3 and 12 months ( + se - 2·27 + 0·7 for weight and -2·65 + 0·69 for adiposity gains, both < 0·005). BM carbohydrate and protein intakes at 4-6 weeks were positively associated with early (0-6 weeks) but tended to be negatively related with later (3-12 months) adiposity gains, while BM fat intake showed no association, suggesting that carbohydrate and protein intakes may have more functional relevance to later infant growth and adiposity.
Topics: Infant, Newborn; Humans; Infant; Female; Pregnancy; Breast Feeding; Milk, Human; Infant Nutritional Physiological Phenomena; Obesity; Eating; Carbohydrates
PubMed: 36259139
DOI: 10.1017/S0007114522003178