Slope Ratio Method Research Articles

Lysine from Whole Wheat Bread Consumed by Healthy Adult Males Has High Metabolic Availability When Assessed Using the Indicator Amino Acid Oxidation Method

BackgroundThe protein quality of wheat is limited by its low content of the indispensable amino acid (AA) lysine and the metabolic availability (MA) of lysine in wheat bread for humans is unknown. ObjectivesThe study objective was to determine the MA of lysine in whole wheat bread. MethodsFive healthy young males (≤30 y, body mass index <25) were studied in a repeated-measures design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each received 7 levels of lysine intakes in random order; 4 levels of L-lysine; 5, 8, 12, and 15 mg/kg/d (reference diet), and 3 intakes of lysine from whole wheat bread (test diet). The MA of lysine in whole wheat bread was assessed by comparing the IAAO response to the test diet (whole wheat bread) with the IAAO response to the reference diet using the slope ratio method. ResultsThe MA of lysine from whole wheat bread was 90%. ConclusionsLysine has a high MA but it is still limiting in whole wheat bread due to its low concentration. A combination of wheat with a complementary protein source (that is, lentils which are sufficient in lysine) is recommended to meet the lysine requirement in a wheat-based diet for healthy young males.This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03200652.

Enhanced Sperm Quality in Aged Broiler Breeder Roosters with Organic Selenium and Selenium Nanoparticles: A Comparative Bioavailability Study.

This study aimed to investigate the impact of dietary selenium treatments on various sperm parameters and antioxidant responses in aged roosters to determine the relative bioavailability value (RBV) and optimize selenium supplementation. Over 40days, starting from week 47 of age, the roosters were fed ten experimental diets, including a basal diet without selenium supplement and nine selenium-treated diets. These selenium-treated diets comprised three different selenium sources (selenium selenite: SS; SelPlex: Se-enriched yeast; selenium nanoparticles: SeNPs), each with three levels of selenium supplements (0.15, 0.30, and 0.45mg/kg). Statistical analysis indicated significant treatment effects on all measured parameters except sperm volume. Sperm motility and viability increased linearly with higher dietary selenium levels. The relative bioavailability values (RBV) of SelPlex and SeNPs compared to SS were estimated using the slope ratio and exponential regression methods. Using the slope-ratio method, the RBV for sperm volume was 457% for SelPlex and 314% for SeNPs, compared to SS. Using exponential regression, the RBV of SelPlex and SeNPs for various parameters were as follows: for MDA (malondialdehyde), 260% and 317%; for TAC (total antioxidant capacity), 447% and 294%; for sperm morphology, 227% and 423%; and for sperm concentration, 346% and 298%, respectively. Principal component analysis revealed strong correlations between sperm motility, viability, and antioxidant parameters, with weaker associations observed between sperm volume and testosterone. Optimization using a desirability function identified 0.45mg/kg selenium supplementation using SeNPs as optimal, maximizing sperm parameters and antioxidant responses while minimizing MDA and morphology. These findings offer valuable insights into effective selenium supplementation strategies to enhance avian reproductive health in aged roosters.

A comparative study between curcumin and curcumin nanoparticles on reproductive performance and antioxidant system of aged roosters

Increased lipid peroxidation and decreased antioxidant status can result in reduced reproductive activity and fertility in aged male broiler breeders. This study was conducted to evaluate the effects of curcumin supplements (natural or nanoparticles) on the sperm characteristics, antioxidant system, fertility, and hatchability of aged roosters (54-64 wk), and to estimate the relative bioavailability value (RBV) of nano-curcumin on the measured parameters including the hypo-osmotic swelling test (HOST), motility, viability, sperm count, volume, the concentration of testosterone, glutathione peroxidase (GPx), and superoxide dismutase (SOD), diameter of the spermatogenic tube (DST), epithelium thickness (EpiTh), spermatogonia count (SPcount), fertility, hatchability, and relative weight of testis (RW-testis). A total of 30 roosters were individually caged and randomly assigned to 5 treatments comprising control (without curcumin as the basal diet), basal diet + 15 mg/kg curcumin (CUR15), basal diet + 30 mg/kg curcumin (CUR30), basal diet + 15 mg/kg nano-curcumin (Nano15), and basal diet + 30 mg/kg nano-curcumin (Nano30) for 10 wk. The slope ratio method was used to estimate the bioavailability of nano-curcumin by regressing each response on supplemental curcumin intake. Increasing dietary curcumin (P < 0.001) elicited a linear response to all studied traits. The RBV for volume, viability, motility, HOST, RW-testis, and GPx were estimated as 135 (CI: 115-156%), 143 (CI: 114-173%), 159 (CI: 122-196%), 132 (CI: 107-157%), 195 (CI: 126-264%), 176 (CI: 103-249%), and 178% (28-328%), respectively. Our findings revealed that curcumin nanoparticles enhance the reproductive efficiency of aged breeder roosters. In addition, the curcumin nanoparticles RBV exceeded that of natural curcumin, suggesting that lower concentrations of curcumin nanoparticles could have a significant effect on reproductive characteristics.

Relative biological efficacy of methionine hydroxy analogue-free acid compared to dl-methionine in the broiler chickens.

In the broiler's diets based on corn-soya bean meal, methionine (Met) and cystine (Cys), known as sulphur amino acids (SAAs), are the first limiting indispensable amino acids because of their limited presence, which are supplemented with different synthetic sources. Evaluation of the biological effectiveness of these sources can be important in their correct replacement, especially in the starter and growth diets. The current study was done to assess the relative biological efficacy (RBE) of liquid Met hydroxy analogue-free acid (MHA-FA) in comparison with dl-Met (dl-Met) based on broiler performance traits at different levels of digestible SAA in the 1-11 (starter) and 11-25 (grower) days of age periods. Two experiments were developed with treatments consisting of a basal diet without Met addition that met the nutrient and energy requirements of broilers with the exception of SAAs (Met+Cys) and five increasing Met doses for both sources (dl-Met and/or MHA-FA), resulting in digestible SAA concentrations from 0.62% to 1.02% of diet in the starter period (Trial 1) and 0.59% to 0.94% of diet in the grower period (Trial 2). The multi-linear regression model and slope ratio method were employed to calculate the RBE of MHA-FA compared with dl-Met for measured variables. In both experiments, the results obtained during the starter and grower periods with the different Met supplementations show significant growth responses to digestible SAAs levels. By increasing dietary dl-Met and/or MHA-FA levels, the growth performance traits and immune responses were improved (quadratic; p<0.05). The RBE of MHA-FA compared to dl-Met on an equimolar basis was estimated 66%-89% (59%-79% on a weight-to-weight basis). It is concluded that the RBE of MHA-FA in comparison with dl-Met depends on broiler chicken age and what attribute is being evaluated.

Exploring the Impact of Cationic Surfactant Ctab on Bleu Brilliant G 250 De Cosmassie: Implications for Health Management and Environmental Sustainability

Background: Surfactants are ubiquitous in both natural and industrial processes due to their unique ability to reduce surface tension and facilitate interactions between hydrophilic and hydrophobic substances. Cationic surfactants like cetyltrimethylammonium bromide (CTAB) are of particular interest because of their widespread applications in areas such as healthcare and environmental management. The interaction between surfactants and dyes, such as Bleu Brilliant G 250 de Cosmassie, is critical in industrial processes, especially in the textile industry where wastewater treatment poses significant environmental challenges. Objective: The aim of this study was to explore the thermodynamic behavior of CTAB when combined with Bleu Brilliant G 250 de Cosmassie in aqueous solutions at room temperature. It sought to determine the critical micelle concentration (CMC) and the degree of counter-ion dissociation (α), and to calculate the changes in Gibbs free energy (ΔGm), enthalpy (ΔHm), and entropy (ΔSm) of the system. Methods: The study employed conductometric and spectrophotometric techniques to analyze the CTAB-dye interactions. Solutions were prepared with varying concentrations of CTAB and Bleu Brilliant G 250 de Cosmassie in deionized water, ensuring solvent purity through stringent conductivity and pH monitoring. Electrical conductance was measured at different temperatures to determine the CMC, while absorbance spectra were recorded to observe changes in the interaction between the surfactant and dye. The degree of counter-ion dissociation was calculated by the slope ratio method, and thermodynamic parameters were computed using established equations. Results: The conductometric studies revealed an increase in CMC with temperature, indicating a stabilization of surfactant monomers at higher temperatures. For CTAB and Bleu Brilliant system 1, the CMC was found to be 0.8 with α valued at 0.83. For system 2, the CMC values were 1.55 and 1.6 with α values of 1.01 and 0.91, respectively. Thermodynamically, the system displayed a Gibbs free energy of micellization of -33.09 KJ/mol, an enthalpy change of -6.53, and an entropy change of 0.1325 JK^-1 mol^-1. Conclusion: The study concluded that the interaction between CTAB and Bleu Brilliant G 250 de Cosmassie is influenced significantly by temperature, which affects the micellization behavior and thermodynamic properties. The findings contribute to a better understanding of the fundamental thermodynamic parameters influencing surfactant-dye interactions, providing insights that may improve industrial processes and environmental sustainability.

A novel methionine nanoparticle in broiler chickens: Bioavailability and requirements.

This bioassay evaluated the bioavailability (RBV) of a novel nanoparticle of methionine (nano-Met) relative to DL-methionine (DL-Met), and estimated methionine requirements for both sources in starting broilers. Five supplemental levels (0.05, 0.10, 0.15, 0.20, and 0.25% of diet) of DL-Met or nano-Met were added to a basal diet containing 0.35% standardized ileal digestible (SID) methionine to create 11 experimental diets, including a basal diet and 10 experimental diets containing 0.40, 0.45, 0.50, 0.55, and 0.60% SID-Met, respectively. A total of 825 one-day-old male Ross 308 birds were randomly assigned to 11 treatments with 5 pen replicates and 15 birds each. Body weight gain (BWG), breast meat yield (BMY), and thigh meat yield (TMY) increased (P < 0.001) while feed conversion ratio (FCR) and malondialdehyde (MDA) concentration in meat samples decreased (P < 0.001) with increasing dietary methionine. Based on the slope-ratio method, the RBV of nano-Met relative to DL-Met for BWG, FCR, and TMY were 102 (48-155%; R2 = 0.71), 134 (68-201%; R2 = 0.77), and 110% (27-193%; R2 = 0.55), respectively. Considering the statistical accuracy of the spline models, the estimated values of DL-Met for maximum BWG and nano-Met for maximum TMY were 0.578% and 0.561%, respectively, which were statistically higher than those recommended for commercial settings. The highest effect size of supplemental methionine was on MDA (ƞ2p = 0.924), followed by FCR (ƞ2p = 0.578), BMY (ƞ2p = 0.575), BWG (ƞ2p = 0.430), and TMY (ƞ2p = 0.332), suggesting the potent antioxidant properties of methionine. Our findings suggest that reducing the particle size of DL-Met to nanoparticles could be a promising strategy to enhance the efficiency of methionine supplementation in broilers, an idea that requires further investigation in future research.

Evaluation of standardized ileal digestibility of amino acids and metabolic availability of methionine, using the indicator amino acid oxidation method, in black soldier fly larvae (Hermetia illucens) meal fed to growing pigs.

Standardized ileal digestibility (SID, %) of crude protein (CP) and amino acid (AA) and the metabolic availability (MA) of Met using the indicator amino acid oxidation (IAAO) method, in partially defatted black soldier fly larvae (PD-BSFL) meal were determined in growing pigs in 2 experiments. The Met SID value was then compared numerically with the Met MA to understand how different SID is compared with its MA value. In Exp. 1, 6 ileal-cannulated barrows (initial body weight [BW] = 18.03 ± 0.34kg) were used in a 2-period switch back design and fed either a nitrogen-free diet (NFD) or test diet, with PD-BSFL meal as the sole source of AA, over two 11-d experimental periods, at a feeding level of 2.8 x estimated maintenance digestible energy requirement. Barrows were adapted for 9-d to the diet, followed by continuous 8-h ileal digesta collection on days 10 and 11. Digesta were pooled per pig within period. The SID of CP and Met of PD-BSFL meal were 76.1 ± 6.2% and 90.4 ± 3.9 %, respectively. In Exp. 2, 7 barrows (initial BW = 18.77 ± 0.69kg) were used in a 7 × 7 Latin square design with L-[1- 13C]-Phe as the indicator AA. Each pig was randomly assigned to 1 of 7 dietary treatments over seven 3-d experimental periods. Two diet types were studied including reference (crystalline AA) and PD-BSFL test diets, each supplying graded intakes of Met at 55, 65, and 75% of the estimated SID requirement (NRC, 2012). The MA of Met was determined by comparing the IAAO response between the reference and PD-BSFL test diet using the slope-ratio method. Linear regression determined a negative slope of the best fit line for both the reference and test diets (P < 0.05). The MA of Met in PD-BSFL meal was 53.3%, which is as expected lower than the SID value. While it is generally appreciated that MA will be less than SID, the use of SID is more practical. In cases where SID cannot explain physiological outcomes of feeding a novel ingredient, IAAO may provide additional insight into whether MA should be explored.

Extraction and Preconcentration of Cd (II) by using Crown Ether DB18C6

Extracted Cd(II) as (CdCl3-) and (CdCl42-) from HCl media after preparing ion pair complexes according to liquid ion exchange method by using DB18C6 after changing to liquid ion exchanger K-Crown+; Cl-, spectrophotometric studies showed that the extracted ion pair complex had a wave length for maximum absorbance of λmax=277nm. Limitations to the study include optimum conditions for extraction in this study show a need for 0.3M HCl, to be present 50µg for Cd(II), in addition to study extracted complex structure by Slope ratio method, the result appear more probable structure of extracted complex [K DB18C6]+;HCdCl4- and [K-DB18C6]+; CdCl3-. This method applied to spectrophotometric determination of Cd(II) in different sample and compare the results with atomic absorption spectroscopy.

Metabolic Availability of Methionine Assessed Using Indicator Amino Acid Oxidation Method, Is Greater when Cooked Lentils and Steamed Rice Are Combined in the Diet of Healthy Young Men

BackgroundLentil is considered a high protein source. However, it is low in sulphur amino acids (SAA) and their metabolic availability (MA) is further affected by antinutritional factors in lentils. The combination of lentils with grains such as rice can enhance the protein quality of a lentil-based meal but the MA of SAA in lentils must first be known. ObjectivesThe objectives of the current study were to assess the MA of methionine in lentils and to test the effects of consumption of complementing lentils with rice in young adults. MethodsFive healthy young men [age <30 y, BMI <25 (in kg/m2)] were each studied at 8 or 10 intake amounts of methionine in random order; 4 daily intake amounts of l-methionine: 0.5, 1, 2, and 3 mg.kg–1.d–1 (reference diet), 3 daily intake amounts of methionine from lentils, and 3 daily intake amounts of the mixed meal of lentils + rice (test diets). The MA of methionine and the effects of complementation were assessed by comparing the indicator amino acid oxidation (IAAO) response to varying intakes of methionine in cooked Canadian lentils, and in rice + lentils combined, compared with the IAAO response to l-methionine intakes in the reference protein (crystalline AA mixture patterned after egg protein) using the slope ratio method. l-[1–13C] phenylalanine was used as the indicator. Data were analyzed using the procedure “MIXED” with subject as a random variable, and oxidation day as repeated measure. ResultsThe MA of methionine from lentils was 69%. Complementation of cooked lentils with rice decreased the oxidation of l-[1–13C] phenylalanine by up to 16% (P < 0.05). ConclusionsThe content and MA of methionine are low in lentils. However, combination of lentils with rice in a 1:1 ratio can improve the protein quality of lentil-based diets, resulting in increased protein synthesis in young healthy adults. This trial was registered at www.clinical trials.gov as NCT03110913.

Bioavailable Lysine Assessed Using the Indicator Amino Acid Oxidation Method in Healthy Young Males is High when Sorghum is Cooked by a Moist Cooking Method

BackgroundSorghum is the fifth most consumed cereal grain but limiting in the indispensable amino acid lysine. Complementing sorghum with lentils can improve the quality of sorghum-based diets. However, knowledge of lysine bioavailability in sorghum is lacking. ObjectivesThe study objectives were to determine the bioavailability of lysine in sorghum and to assess the effect of complementation of sorghum and lentils in a mixed-meal format. MethodsWe studied 5 healthy young men (≤30 years; BMI <25 kg/m2) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1–13C] phenylalanine as the indicator. Each subject participated in 8 determinations in random order. On the reference diet, subjects received 4 amounts of L-lysine (5, 8, 12, and 15 mg. kg–1. d–1) from a crystalline amino acid mixture patterned after egg protein. On the test diet, they received 3 levels of lysine (8.2, 12.5, and 15.7 mg. kg–1. d–1) from sorghum, and on the complementation diet they received 1 level of lysine from a mixed meal of sorghum and lentils. The bioavailability of lysine in sorghum was estimated by comparing the IAAO response to the test diet with the IAAO response to the reference diet using the slope-ratio method. Effectiveness of complementation was assessed by comparing the IAAO response to the mixed meal to the IAAO response to the test protein. ResultsThe bioavailability of lysine from sorghum was 94%. Upon complementation with lentils, there was a decline in the oxidation of L-[1–13C] phenylalanine by 19% (P < 0.0495), reflecting an improvement in available lysine in the mixed meal due to increased lysine intake. ConclusionsAlthough the bioavailability of lysine in sorghum is high, its lysine content is limiting. Complementation with lentils in a 1:1 ratio is recommended to achieve the lysine requirement for adult men consuming a sorghum-based diet. This trial was registered at http://www.clinicaltrials.gov clinicaltrials.gov as NCT03411005.

Mechanism unravelling for highly efficient and selective 99TcO4 - sequestration utilising crown ether based solvent system from nuclear liquid waste: experimental and computational investigations.

Selective and efficient separation of pertechnetate (TcO4−) from nuclear waste is desirable for the safe and secure management of radioactive waste. Here, we have projected dibenzo-18-crown-6 ether (DB18C6) in a highly polar nitrobenzene medium for enhancing the removal efficiency of 99Tc from reprocessing plant low level waste (LLW). An effort was made to determine the stoichiometry of metal–ligand complex by slope ratio method, revealing that one ligand (DB18C6) binds with one TcO4− moiety. Optimum ligand concentration for 99Tc extraction was evaluated. Relevant interference of the anions was studied systematically. The effect of solution pH was analysed on the extraction efficiency of 99Tc. A kinetic study was carried out for maximum extraction of metal ions. A quantitative stripping study was also achieved for metal ions with a suitable stripping solution. After evaluation of all essential parameters, selectivity and feasibility studies were finally carried out with actual low level reprocessing plant waste to demonstrate a laboratory scale process for effective separation of TcO4− ions. Density functional theory (DFT) calculations were carried out to understand the nature of the complexation of TcO4− ion with DB18C6 in different solvents systems and to elucidate the key aspect behind ionic selectivity and enhanced the 99Tc extraction efficiency of DB18C6 in the studied diluent systems. The ΔE and ΔG values for different modeled complexation reactions were evaluated systematically. From the calculated free energy of complexation of TcO4− with DB18C6, it was observed that the consideration of explicit solvent plays a vital role in predicting the experimental selectivity.

Design and optimization of sensitive analytical spectrophotometric method for micro determination of copper(II) from e-waste by using of novel chromogenic extractant

In this article, a novel spectrophotometric reagent 1-(pyrimidine)-4, 4, 6-trimethyl-1,4-dihydropyrimidine-2-thiol [PTPT] has been synthesized for liquid–liquid extraction and spectrophotometric determination of copper(II). The as-synthesized ligand has been selectively forms stable complex with copper(II) in basic medium (pH 9.0), in presence of mild pyridine the extraction and color stability has found to be synergistically enhanced. The equilibrium time is 10 min for effective extraction of copper(II) from organic phase and absorbance of colored organic complex in carbon tetrachloride is measured spectrophotometrically at λmax 615 nm against reagent blank. The ternary complex of Cu(II)-PTPT-Py having molar ratio 1:2:2 (M:L:Py) showed green colored complex. The main factors influencing the achievement of synergistic extraction; i.e. pH, ligand concentration, type and volume of the dispersive organic solvents, equilibrium time, synergent concentration and foreign ions were investigated.The Beer’s law was obeyed in the concentration range 1–20 μg mL−1 of copper(II) and optimum concentration range is evaluated by Ringbom’s plot and it is found that 2.5–25 μg mL−1. In presence of pyridine, molar absorptivity and Sandell’s sensitivity of copper(II)-PTPT complex is 2.80 × 103 L mol−1 cm−1 and 0.226 μg cm−2, respectively and in absence of pyridine, molar absorptivity and Sandell’s sensitivity of copper(II)-PTPT complex is 1.35 × 103 L mol−1 cm−1 and 0.469 μg cm−2, respectively. The stoichiometry of the copper(II)-PTPT-pyridine complex was calculated by slope ratio method, mole ratio method and Job’s method of continuous variation and it has been found as 1:2:2. No significant effects of potentially interfering species i.e. cations and anions were observed. The optimized method was applied for the determination of copper(II) in binary, synthetic mixtures and successfully applied for determination of copper(II) from e-waste samples. The standard deviation (R.S.D.) is 0.11% for n = 5 repetition. The reliability of the developed method is confirmed by comparison of experimental results with atomic absorption spectrophotometer.

A Modified Procedure for Slope Ratio Method in Analysis of 1:1 Complex Compounds.(Dept.P)

This p ublication modifies the experimental procedure of slope ratio method for 1:1 metal-chelates via correct choosing of reference samples. This modification was followed in studying complex formation of cerous and ferric ions with 1,2 bis (beta-aminoethoxy) ethane N, N, N', N' sodium sulfonate triacetic acid. The obtained results, after correct choice of reference samples, gave one straight line (for the two chelates) instead of two p arallel lines when the slope ratio method was applied without modification. The discussion of the differences between obtained results before and after modification is given. The correct choice of reference samples may be extended similarly to the other analytical methods of studying complex formation to get more accurate results.

Phosphorus digestibility and relative phosphorus bioavailability in two dried black soldier fly larvae meals and a defatted black soldier fly larvae meal in broiler chickens

Two chicken assays were conducted to determine P availability, using three different approaches, for 2 black soldier fly larvae meals (BSFL 1 and 3) and one partially-defatted BSFL. Experiment 1 was conducted to determine ileal P digestibility and total tract P retention. Three experimental diets containing a BSFL as the only source of P were fed to broiler chickens from 19 to 22 days of age. Each diet contained 0.25% total dietary P. Ileal digesta and excreta were collected on day 22. Ileal digestibility of P was 87%, 75%, and 88% for BSFL 1, BSFL 3, and partially-defatted BSFL, respectively. Total tract P retention was 87%, 73%, and 85% for BSFL 1, BSFL 3, and partially-defatted BSFL, respectively. The objective of experiment 2 was to determine the relative bioavailability of P in the 3 insect meals relative to KH2PO4 using a chicken bone ash bioassay. Chickens were fed one of nine dietary treatments from 8 to 22 days of age. These diets included a P-deficient cornstarch-dextrose-SBM based diet (0.14% nonphytate P) or that diet supplemented with 0.05% or 0.10% P from KH2PO4, 7% or 14% BSFL 1, 8%, or 16% BSFL 3, and 8% or 16% partially-defatted BSFL. The slope-ratio method using multiple regression for tibia ash regressed on supplemental P intake was used to calculate the relative bioavailability of P where values for BSFL 1, BSFL 3, and partially-defatted BSFL were 54%, 51%, and 57%, respectively, relative to KH2PO4. The results of this study indicated that availability of P in BSFL based on ileal P digestibility and total tract P retention values was high, whereas relative bioavailability values for P based on tibia ash were approximately 20 to 30 percentage units lower.

A Fast Audit Doubt Finding Model

In order to improve the audit efficiency and accuracy under the condition of big data, an audit doubt discovery model (CLOWF) based on an adaptive clustering outlier detection algorithm is proposed. The model first uses the slope ratio method to obtain the K value of the K-means++ algorithm, thereby effectively ensuring the clustering effect; At the same time, for the problem of slow pruning speed, a parallel calculation method for the data radius and centroid of each cluster is proposed and designed; Combined with the weighted local outlier factor detection algorithm to calculate the outlier factor, the data greater than the epsilon threshold of outlier is proposed as an indicator to determine the audit doubt. Through auditing application cases, comparing the local outlier factor detection algorithm and the cluster-based outlier detection algorithm, the results show that the execution time of the CLOWF model is the shortest and the accuracy rate is 97.3%.

The "Brain Stethoscope": A Non-Invasive Method for Detecting Elevated Intracranial Pressure.

IntroductionMinimally invasive intracranial pressure (ICP) screening has long been desired by neurosurgeons. A novel approach deriving ICP from tympanic membrane (TM) pulsation may offer the solution. The ICP waveform appears to be transmitted to the TM by the cochlear aqueduct. The resulting TM infrasonic pulsations can be measured by certain sensors. Elevated ICP alters brain compliance, which appears to yield slower rise times of the TM pulsation waveform. Measurement of this change may be useful in screening for elevated ICP. This paper investigates one such technique.MethodsA stethoscope was modified for airtight external ear canal fit; the dome was exchanged for a magnetic reluctance pressure sensor, allowing measurement of TM pulsations. Analog TM pulsations were analyzed by measuring the pulsation's slope ratio between the waveform’s downslope and upslope. Seventeen normal subjects (ages 18-32 years) underwent hyperventilation and tilt table testing to induce ICP changes. An algorithm processed this data and predicted the subject's ICP status.ResultsThe slope ratio method showed consistent and stable changes with the expected alterations in ICP from the tilt test and hyperventilation maneuvers. The classification algorithm correctly identified subjects with elevated ICP in 60 of 60 independent recordings on 17 subjects.ConclusionThis paper has four conclusions. First, the "brain stethoscope" can detect increased ICP from the TM pulsation waveform in healthy subjects. Second, analysis of the TM waveform using slope ratio calculations is capable of distinguishing normal versus elevated ICP. Third, the tilt and hyperventilation maneuvers showed the expected physiologic trends. Last, further studies are needed on patients with pathological ICP before the brain stethoscope can be implemented into clinical practice.

Recovery of boron from unacidified salt lake brine by solvent extraction with 2,2,4-trimethyl-1,3-pentanediol

In this work, the extraction of boron from salt lake (SL) brine using 2,2,4-trimethyl-1,3-pentanediol (TMPD) was investigated. Factors affecting boron recovery during the solvent extraction process, including feed pH, concentrations of extractant and H3BO3, phase ratio of organic to brine (O/A), and temperature, were investigated. Increasing feed pH initially resulted in a high boron extraction rate, but there was a limitation, as further increasing feed pH resulted in rapid formation of B[OH]4− having a low capacity to complex with TMPD, and therefore lower boron extraction. Boron recovery increased as the TMPD concentration and O/A increased. Salting-out effect experiment indicated that the addition of magnesium chloride showed two opposite effects on boron extraction. The combination of pH <7, O/A = 1 & TMPD/H3BO3 molar ratio = 2:1 was ideal for boron recovery, resulting in single-stage boron extraction efficiency of >85% and three-stage of 99.79%. To investigate the extraction mechanism, the slope ratio method was combined with Raman spectroscopy and infrared spectroscopy to characterize the structure of TMPD and boron complex in organic extraction solvent. Furthermore, under the optimal conditions, a three-stage extraction and two-stage stripping process was performed, resulting the extraction and stripping efficiency of boron were 97.12% and 88.98%, respectively. The results of the study reveal a promising strategy of boron recovery from SL brine without acidification.

Digestibility and bioavailability of organic calcium sources for European quail

The objective of this study was to determine the apparent and true digestibility coefficients and relative bioavailability of charru mussel, maçunim (Anomalocardia brasiliana) and oyster shells as organic calcium sources for meat quail. In the digestibility trial, 240 quail were distributed in a completely randomized experimental design with five diets (calcitic limestone, calcium carbonate and three marine calcium sources), five replicates and eight quails per experimental unit. The relative bioavailability of calcium was determined by the standard-curve and slope ratio methods in a growth trial in which 288 European quail were distributed in completely randomized experimental design. Treatments consisted of basal diet with a low calcium concentration (0.166%) that was supplemented with two levels of calcium (0.342% and 0.684%) derived from different calcium sources. The apparent and true digestibility coefficients of calcium from charru mussel-, maçunim- and oyster-shell meals for meat quail were 91.85 and 92.04%; 91.71 and 91.90%; and 89.39 and 89.63%, respectively. The relative bioavailability of calcium from charru mussel-, maçunim- and oyster-shell meals obtained using standard-curve and slope ratio methods were 133.22 and 119.18%; 140.05 and 113.69%; and 141.73 and 106.22%, respectively, allowing the use of these organic calcium sources in diet formulations for meat quail.

Variation in the chemical composition and the nutritive quality of different field bean UK-grown cultivar samples for broiler chicks

ABSTRACT 1. The chemical composition and physical characteristics of 10 different UK-grown field bean cultivar samples from the same harvest year were determined. 2. Diets included each bean sample at a level of 200 g/kg, and were used to compare broiler growth performance and determine N-corrected apparent metabolisable energy (AMEn) and nutrient utilisation. The AMEn and nutrient retention coefficients for the bean samples were obtained via the slope-ratio method. The relationships were examined between variation in nutritive value for broilers and the laboratory analysis of the bean samples. 3. The data showed significant differences (P < 0.05) among the bean cultivar samples for feed conversion ratio, AMEn and dry matter retention (DMR) coefficients. Further analysis showed that the feeding quality of different field bean cultivar samples, measured as AMEn, was highly correlated to crude protein (CP) (P < 0.05) and colour (P < 0.001) of the samples. Thus, beans with higher CP and pale colour had superior feeding value for broilers.

Bioavailable Lysine, Assessed in Healthy Young Men Using Indicator Amino Acid Oxidation, is Greater when Cooked Millet and Stewed Canadian Lentils are Combined

Pearl millet is the chief source of energy in the diet in some developing regions, but has a limited amount of indispensable amino acid lysine. Complementation with pulses like lentils can improve the protein quality of millet diets, but the knowledge of lysine bioavailability (BA) in millet and lentils is lacking. The study objectives were to determine the BA of lysine in millet and lentils separately and to assess the effect of complementation of millet and lentils in a mixed meal format. We studied 9 healthy young men (≤30 y; BMI<25) in a repeated-measure design using the indicator amino acid oxidation (IAAO) method, with L-[1-13C] phenylalanine as the indicator. Each subject completed 7 or 8 experiments in random order. On the reference diet, subjects received 4 graded levels of L-lysine (5, 8, 12, and 15 mg·kg-1.d-1) from a crystalline amino acid mixture patterned after egg protein; on the test diets, they received 3 levels of lysine (10, 12, and 15 mg·kg-1.d-1) from either steamed millet or stewed lentils; and on the complementation diet, they received 1 level of lysine from a mixed meal of steamed millet and stewed lentils. The BA of lysine and the effect of complementation were assessed by comparing the IAAO responses to the test diets and the complementation diet with the IAAO response to L-lysine intakes in the reference protein, using the slope ratio method. The BA of lysine was 97% from millet and 80% from lentils. Complementation of steamed millet with stewed lentils decreased the oxidation of L-[1-13C] phenylalanine by 27% (P<0.05), signifying improved quality of the combined millet and lentil protein. Lysine has high BA but is still limiting in steamed pearl millet. Complementation with lentils in a 2:1 ratio is recommended to meet the lysine and protein requirements for adult men consuming a millet-based diet. This trial was registered at clinicaltrials.gov as NCT03674736 and NCT03339167.