Absorption Kinetics Research Articles

Average Slope vs. Cmax: Which Truly Reflects the Drug-Absorption Rate?

Despite ongoing concerns, the primary metric utilized in bioequivalence studies to quantify absorption rate remains the maximum plasma concentration (Cmax). To more accurately depict absorption rate, the concept of “average slope” (AS) has been recently introduced. The objective of this study is to elucidate and compare the characteristics of AS and Cmax in their representation of the drug-absorption rate. For this purpose, an investigation was conducted on five drugs (nintedanib, methylphenidate, nitrofurantoin, lisdexamfetamine, and theophylline) with different absorption and disposition kinetics. The properties of AS and Cmax, as well as their correlations with other pharmacokinetic parameters, were assessed using supervised and unsupervised machine-learning algorithms, namely principal component analysis, random forest, hierarchical cluster analysis, and artificial neural networks. This study showed that, regardless of the absorption kinetics and across every ML algorithm, AS was more sensitive in reflecting the absorption rate compared to Cmax. In all drugs and methods of analysis, AS demonstrated significantly superior performance in expressing the absorption rate compared to Cmax. The joint use of different techniques complemented each other and verified the findings. Moreover, AS can be easily calculated and has the appropriate units and properties to be used as a metric to express the absorption rate in bioequivalence studies. The adoption of AS by regulatory authorities, as an absorption-rate metric, could significantly improve the accuracy and reliability of BE assessments. Overall, this study focused on addressing the longstanding problem of finding an appropriate absorption-rate metric by demonstrating the desirable properties of AS.

Multiaxial filament winding of biopolymer microfibers with a collagen resin binder for orthobiologic medical device biomanufacturing

Multiaxial filament winding is an additive manufacturing technique used extensively in large industrial and military manufacturing yet unexplored for biomedical uses. This study adapts filament winding to biomanufacture scalable, strong, three-dimensional microfiber (3DMF) medical device implants for potential orthopedic applications. Polylactide microfiber filaments were wound through a collagen ‘resin’ bath to create organized, stable orthobiologic implants, which are sized for common ligament (e.g. anterior cruciate ligament) and tendon (e.g. rotator cuff) injuries and can be manufactured at industrial scale using a small footprint, economical, high-output benchtop system. Ethylene oxide or electron beam sterilized 3DMF samples were analyzed by scanning electron microscopy (SEM), underwent ASTM1635-based degradation testing, tensile testing, ISO 10993-based cytocompatibility, and biocompatibility testing, quantified for human platelet-rich plasma (PRP) absorption kinetics, and examined for adhesion of bioceramics and lyophilized collagen after coating. 3DMF implants had consistent fiber size and high alignment by SEM. Negligible mass and strength loss were noted over 4 months in culture. 3DMF implants initially exceeded 1000 N hydrated tensile strength and retained over 70% strength through 4 months in culture, significantly stronger than conventionally produced implants made by fused fiber deposition 3D printing. 3DMF implants absorbed over 3x their weight in PRP within 5 min, were cytocompatible and biocompatible in vivo in rabbits, and could readily bind tricalcium phosphate and calcium carbonate coatings discretely on implant ends for further orthobiologic material functionalization. The additive manufacturing process further enabled engineering implants with suture-shuttling passages for facile arthroscopic surgical delivery. This accessible, facile, economical, and rapid microfiber manufacturing platform presents a new method to engineer high-strength, flexible, low-cost, bio-based implants for orthopedic and extended medical device applications.

Enhanced CO2 absorption in amine-based carbon capture aided by coconut shell-derived nitrogen-doped biochar

The sluggish CO2 absorption kinetics and constrained CO2 absorption capacity diminish the practicality of using amine-based absorption for CO2 capture, impeding progress toward carbon neutrality goals. This study aims to develop a catalytic CO2 absorption process to promote CO2 absorption by introducing a solid base catalyst, namely, coconut shell-derived nitrogen-doped biochar (NBC), into an amine-based solution. The coconut shells were modified with urea and activated with KOH to prepare an NBC catalyst with improved basic characteristics. The findings showed that compared to non-catalytic absorption, the NBC catalyst increased the CO2 absorption amount, CO2 absorption rate, and absorption efficiency of the monoethanolamine (MEA) solution by 16.9 %, 43.4 %, and 13.1 %, respectively. The basic sites on the NBC surface provided extra electrons to motivate the formation of MEACOO- and HCO3-. NBC’s large surface area and porous structure also advanced the gas–liquid mass transfer, accelerating the CO2 absorption rate. Furthermore, the NBC exhibited excellent cyclic stability and facilitated the subsequent CO2 desorption process. This work develops a promising and practical approach to significantly improve the amine-based absorption and reuse of waste biomass resources for efficient CO2 capture.

Fizyczne i mechaniczne zachowanie betonu z recyklingu poddanego testom niszczącym i nieniszczącym

Aggregates recycled from construction sites may exhibit slightly inferior characteristics compared to natural aggregates in terms of porosity, friability, and variability. However, it must be acknowledged that although recycled aggregates are currently used only in small proportions for manufacturing concrete, their usage is steadily increasing. It is now widely recognised that the reuse of recycled aggregates in mortar and concrete significantly contributes to the preservation of alluvial aggregates. The valorisation of recycled aggregates in concrete and mortar offers a clear economic advantage in the construction sector. Indeed, the reuse of materials from demolition could be envisaged directly on site or at construction waste recycling and treatment platforms. Additionally, it should be noted that to date, there is no specific standard for measuring the water absorption of recycled aggregates. Regarding the physical properties, the estimation of the absorption kinetics of the recycled aggregates has proved necessary. Moreover, other equally important measurements must be undertaken to determine all the other properties. The results obtained demonstrated that a good correlation exists between the substitution rate and the physical and mechanical properties of the prepared concrete. Furthermore, it was decided to vary the substitution rate of natural sand with recycled sand during the manufacture of concrete according to the following percentages: 25% recycled sand with 75% natural sand, and 50% recycled sand with 50% natural sand.

Constructing a hydrogel based on self-assembly properties of glycyrrhizic acid: A drug delivery system with digestive tract responsive

Glycyrrhizic acid (GA), an amphiphilic compound, is known for its natural sweetness and excellent self-assembly properties. Based on its self-assembled formulation forming ability, GA has been used as drug carriers and absorption enhancers, thereby altering the in vivo absorption kinetic processes of loaded drugs. This study mainly focuses on the influence of the GA self-assembled drug delivery system on the solubility, stability, and in vitro release of various active ingredients in traditional Chinese medicine, especially simulating the physiological rhythms and environment of in vivo absorption. Our findings indicate that GA has a significant solubilizing effect on poorly water-soluble components. The inclusion of GA improves the stability of the majority of the measured components to different extents in the digestive tract. Furthermore, in vitro release studies have demonstrated that the GA hydrogel system effectively slows drug release and is also enterosoluble, indicating responsiveness to the digestive tract, which contributes to stable concentrations of the drug in the blood. To sum up, the GA self-assembled drug delivery system can enhance solubility and stability to varying degrees by altering the in vivo absorption kinetics of representative active ingredients, exhibiting drug sustained release and self-assembly system enteric-like characteristics in different physiological environments. This indicates that the drug delivery system formed by GA through self-assembly can interact with the digestive tract environment, thus enhancing the in vivo bioavailability of drugs by influencing their biopharmaceutical properties.

Synthesis of graphene oxide-choline chloride in order to remove phosphate ion from aqueous samples: study of mechanism, isotherm and adsorption kinetics

In this study, a graphene oxide-choline chloride adsorbent was used as a highly efficient and environmentally friendly material for removing phosphate ions from aqueous samples. Graphene oxide was synthesized using the Hummers method and then modified with choline chloride to create the graphene oxide-choline chloride adsorbent. The synthesized adsorbent was characterized using Fourier transform infrared spectrophotometry (FT-IR), Field Effect Scanning Electron Microscopy (FESEM), and Energy-dispersive X-ray spectroscopy (EDX). It was then applied to remove phosphate ions at different pH levels and stirring times. The results of this study showed that the maximum removal efficiency of phosphate ions was achieved at pH 5, with an adsorbent amount of 0.015 g and a stirring time of 30 minutes. Furthermore, it was observed that the adsorption of phosphate ions on the adsorbent surface followed the Langmuir isotherm (monolayer adsorption), with a maximum adsorption capacity of 217.4 mg/g. The examination of absorption kinetics also revealed that the absorption of phosphate ions followed pseudo-second-order kinetics, and an increase in temperature favored the progress of the reaction.

Elucidating the dynamics behavior of PFASs at the water and hydrophobic low-melting mixture solvents interphase

In this work, we studied the interphase dynamics of hydrophobic low-melting mixture solvents (LoMMSs) for the advanced remediation of per- and polyfluoroalkyl substances (PFASs) in wastewater systems by using classical molecular dynamics (MD) simulations. We showed the interaction between widely prevalent PFAS-specifically perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) and an innovative LoMMS composed of cineole (CIN) and linoleic acid (LNA) at equimolar ratios. Our investigations reveal that the interphase diffusion of PFASs through the LoMMS is a multi-stage process involving diffusion, interface sorption, and subsequent migration into the bulk aqueous phase. The simulations underscore a robust affinity between the PFASs molecules and the LoMMS, with the displacement of PFASs from the water interface marked by the formation of complex hydrogen-bonded networks. This intricate interplay results in a significant reorganization of water molecules, leading to potential clustering at the interface and compression of the fluid phase. These findings not only substantiate the efficacy of LoMMSs in PFASs extraction but also highlight the need to account for competitive interactions at the water interface, which could impede the absorption kinetics. By providing a detailed molecular-level narrative of the interphase capture phenomena, this study paves the way for designing efficient, low-toxicity LoMMS-based systems for the targeted removal of PFASs from contaminated water sources.

Hydrogenation features of TiZrHfNbTa high-entropy alloy produced by calcium-hydride synthesis

A high-entropy alloy TiZrHfNbTa has been synthesized by a method of the mutual reduction of the higher oxides of corresponding metals with calcium hydride. The alloy structure was characterized and hydrogen absorption properties were studied. The alloy of overall equiatomic composition TiZrHfNbTa consists of two BCC phases with unit cell parameters of 3.419 and 3.328 Å. The distribution of the elements was established as follows: Ti0.21Zr0.24Hf0.24Nb0.25Ta0.06 (BCC-I) and Ti0.15Zr0.05Hf0.10Nb0.08Ta0.62 (BCC-II). The hydrogenation behavior of the alloy under different conditions was thoroughly studied. It was shown that complete hydrogenation resulted in the formation of FCC-type (H/M → 2) and BCT-type hydrides (H/M → 1) from BCC-I and BCC-II, respectively. Under low hydrogen pressure (< 212.8 Torr), BCC-I absorbed up to 0.33 at. H/M within a solid solution without changing the structural type. According the kinetic analysis, this process can be described as a second order reaction with activation energy of 102 kJ/mol. The BCC-I-based solid solution is capable of retaining hydrogen in a deep vacuum at a temperature of 430 °C. The fast kinetics of hydrogen absorption and high thermal stability allow us to suggest the studied two-phase TiZrHfNbTa alloy as a promising getter for vacuum devices.

Sensory qualities and hydration kinetics of instant-extruded cereals with flaxseed and amaranth

PurposeThe purpose of this study was to evaluate the effects of the addition of flaxseed and amaranth at different proportions on the hydration kinetics, colour and sensory qualities of instant-extruded cereals, important aspects related to the functionality and acceptability of food products.Design/methodology/approachInstant-extruded cereals were made with different proportions of flaxseed (6.6–9.3%), amaranth (18.7–33.1%), and maize grits (63.8–67.3%); and characteristics such as hydration kinetics, colour parameters and sensory properties were evaluated.FindingsThe kinetics of milk absorption showed that the extruded cereals maintained their texture and crispness for a sufficiently long time (≤20 min). The L*, a* and chroma* values of the extruded cereals were significantly affected (p < 0.05) by the flaxseed content. Sensory evaluation showed that all the extrudates had good acceptance in terms of flavour, texture, and colour attributes in relation to high-fibre commercial cereals; according to the preference test, they were as acceptable as commercial extruded cereals when consumed with milk. The addition of high-fibre and protein-containing grains such as flaxseed (8.6–9.3%) and amaranth (18.7–22.9%) in instant-extruded cereals allowed the production of products with acceptable physical and sensory characteristics.Originality/valueIn this study a novel instant-extruded cereal with flaxseed and amaranth was developed. The evaluation of the physical and sensory characteristics of instant-extruded cereals is essential to guarantee consumer acceptability, especially if functional ingredients with a high content of dietary fibre and protein are added.

Exploring microstructure variations and hydrogen storage characteristics in TiVNbCrNi high-entropy alloys with different Ni incorporation

In recent years, high-entropy alloys (HEAs), as a novel class of hydrogen storage materials, have been deemed highly promising due to their extensive compositional tunability and the unique high entropy effects. This study aims to enhance the comprehensive hydrogen storage performance of the TiVNbCr-based HEA by introducing Ni. The effects of Ni addition on the microstructural evolution of the alloy and its impact on activation properties, hydrogen absorption and desorption kinetics, thermodynamics, and cycling performance under the complex physicochemical environment of multiple principal elements was systematically investigated. The findings indicate that Ni addition shortens the activation incubation period of the alloy but more Ni reduces the intrinsic hydrogen absorption kinetics. In the Ti25V30Nb10Cr33Ni2 alloy, a high reversible hydrogen storage capacity of up to 2.2 wt% at room temperature was achieved, surpassing most of the currently reported body-centered cubic (BCC)-structured high-entropy hydrogen storage alloys. Furthermore, the influence of Ni on the alloy's hydrogen desorption kinetics and cycling hydrogenation performance was studied. Results from 110 cycles of testing reveal that the introduction of Ni-induced Laves phases can act to relax stress, thereby reducing strain accumulation during the hydrogen absorption and desorption cycling process. This could provide guidance for the design of high-entropy hydrogen storage alloys with extended cycling lifetimes.

Effect of limestone particle size and microbial phytase on phosphorus and calcium digestion kinetics along the gastrointestinal tract in laying hens

ABSTRACT 1. This study assessed the effect of limestone particle size and microbial phytase incorporation on the fate of phosphorus (P) and calcium (Ca) along the gastrointestinal tract in 72 laying hens. 2. Four experimental diets were formulated according to a 2 × 2 factorial arrangement to evaluate the effect of two coarse limestone (CL) inclusion. This included a mix (MIX) of 75% CL (2 − 4 mm) and 25% fine particles (FL, <0.5 mm) or 100% FL, in two different basal diets formulated without (MIX0 and FL0) or with 300 FTU of microbial phytase/kg (MIX300 and FL300). 3. Contents of the crop, gizzard, duodenum, jejunum and ileum were collected to determine the mean retention time (MRT) of dry matter (DM), the recovery rate of Ca and P in each segment of the gastrointestinal tract and the apparent fractional digestibility coefficient (AD) of Ca and P in each intestinal segment. 4. In hens fed FL, microbial phytase decreased the MRT of DM along the intestine (p < 0.05). In the crop and the gizzard, Ca recovery increased with MIX incorporation to a greater extent in hens fed without microbial phytase (p < 0.05). The mixed particle size incorporation decreased absorption kinetics of Ca in hens fed microbial phytase. The AD of P and the absorption kinetics of P were significantly decreased in hens receiving FL300, probably due to complex formation between Ca and phytic acid. 5. This study showed that coarse limestone particles incorporation improved mineral utilisation along the digestive tract.

Effect of absorption kinetics of superabsorbent polymers on printability and interlayer bond of 3D printing concrete

This study examines the effect of the material characteristics of superabsorbent polymers (SAPs) on the printability and interlayer bond strength of 3D printing concrete. Three types of SAP, including two acrylamide-co-acrylic polymers with coarse and fine particle sizes (S1 and S2) and an acrylic copolymer (S3), were employed. The investigated mortar mixtures had a fixed initial mini-slump flow of 195 ± 10 mm and yield stress of 290 ± 25 Pa. The fluidity of SAP-incorporated mortars was maintained by either adjusting the superplasticizer dosage or increasing the water content. Test results indicate that particle flocculation is dependent on SAP absorption kinetics shortly after the end of mixing. The use of S1 and S2 SAPs exhibiting high retention ability enhanced thixotropy, whereas the S3 SAP with rapid desorption reduced thixotropy. The S2 SAP improved the bridging effect of nucleation at early age due to its finer size, leading to a significant increase in the structuration rate at 30 min. Pull-out strength test and splitting tensile strength test were used to investigate the interlayer bond strength. The S1 SAP was the most significant in maintaining a higher internal relative humidity (IRH), thus resulting in higher 28-d interlayer bond strength, while the S2 SAP exhibited an intermediate ability to maintain elevated IRH, thus resulting in higher increase in 7-d interlayer bond strength.

Modeling heat and mass transfer in metal hydride hydrogen storage systems: Impact of operating parameters and reactor geometry

This work introduces a transient 2D axis-symmetrical model for hydrogen absorption in a cylindrical LaNi5 reactor employing finite volume method with a fully implicit Euler's time integration scheme, coupling equations for heat, mass, and momentum transport. The validated model is used to investigate the impacts of pressure, cooling fluid temperature, and variations in reactor geometry and size on temperature and reacted fraction profiles. The findings reveal that the charging pressure affects both peak temperature and reaction kinetics, whereas cooling fluid temperature predominantly impacts the absorption kinetics. A comparative analysis of two models, one incorporating Darcy's velocity and one without, demonstrates that while Darcy's law introduces numerical instability in the coupled equations, its impact on the model outcomes is negligible. The effect of changing the non-homogeneous Neumann to Dirichlet boundary condition is also demonstrated to anticipate the utilization of phase change materials (PCM) instead of the cooling fluid.

Aristolochic Acid Exposure via Dermal Contact or Inhalation of Herbal Powders: Evidence of Occupational Exposure in Herbalists with Urothelial Cancer.

Emerging evidence showing urothelial cancer in herbalists is linked to aristolochic acid (AA) exposure; however, the exposure pathway remains unclear. Here, we show that dermal contact and inhalation of fine powders of AA-containing herbs are significant occupational AA exposure pathways for herbalists. We initiated the study by quantifying the amount of AA in the AA-containing powder deposited on gloves and face masks worn by the operators of an AA-containing herb grinding machine. Then, we measured the kinetics of dermal absorption and dissolution of AA from fine powders of AA-containing herbs into artificial sweat and surrogate lung fluid. Lastly, we quantified the mutagenic AA-DNA adduct levels formed in the kidneys of mice exposed to AA-containing fine powders through dermal contact. Our findings highlight an urgent occupational risk that should demand implementation of safety standards for herbalists exposed to AA-containing fine powders.

Synthesis of Mg2FeH6 by High‐Temperature High‐Pressure Reactive Planetary Ball Milling

Herein, a new approach for the synthesis of metal hydrides using simultaneous high‐temperature and high‐pressure reactive ball milling is demonstrated by preparing ternary magnesium iron hydride. The novelty and uniqueness of this technique are based on its integration of a specially designed and manufactured milling vial, allowing synthesis at controlled elevated temperatures (room temperature [RT]–400 °C) and pressures up to 100 bar. A Mg and Fe (2:1) mixture is used as a substrate for Mg2FeH6 synthesis. The effects of temperature on the synthesis kinetics and their outcomes are examined. An increase in the temperature accelerates the kinetics of hydrogen absorption for MgH2, while Mg2FeH6 formation is observed only above 250 °C. Increasing the reaction temperature not only causes magnesium particle refinement due to the hydrogenation and formation of magnesium hydrides but also leads to the agglomeration of iron caused by plastification due to a lack of strain hardening. The maximum conversion to Mg2FeH6 is observed for the sample premilled at RT. In this work, it is revealed that additional physical variables, e.g., pressure, temperature, time, and milling speed, during mechanochemical synthesis and material properties, need to be evaluated and considered to improve the reaction kinetics and yield of the synthesis.

Mass transfer and kinetic measurement and modeling for CO2 absorption into aqueous EAE and water-lean EAE/NMP solvents

Chemical absorption using amine solvent is currently available technology for CO2 capture from post-combustion flue gas. It is hindered by high operating cost and high capital cost due to high regeneration energy and slow CO2 absorption rate of amine solvent. Water-lean solvent of 2-(ethylamino) ethanol (EAE)/1-methyl-2-pyrrolidinone (NMP)/water could be a potential solution as it achieved significantly low regeneration energy of 2.3 GJ/tCO2 tested in a pilot plant. However, kinetics of CO2 reaction with EAE and mass transfer rate of CO2 absorption into EAE/NMP solvent are not fully understood. In this work, kinetics of CO2 absorption into unloaded aqueous EAE in 1–5 mol/L at 300–313 K and mass transfer of CO2 absorption into CO2-loaded EAE/NMP water-lean solvent in 5 mol/L with equilibrium CO2 partial pressure (PCO2*) range of 0.3–7 kPa at 312 K were studied in a wetted wall column. Kinetic data of aqueous EAE is interpreted by zwitterion mechanism, and the reaction is of first order with respect to EAE concentration in 1–5 mol/L at 300–313 K. CO2 absorption rate (kg’) of EAE/NMP water-lean solvent is 1.3–2.1 times greater than aqueous EAE due to the greater CO2 physical solubility. At lean and rich loading conditions, 5 M EAE in 3NMP/1water and 9NMP/1water show 2–7 times faster kg’ than 30 % MEA, and 1.4–2.5 times faster kg’ than 30 % PZ. It is found that EAE activity coefficient may increase in the presence of NMP in the solvent, and the estimated EAE activity coefficient in 1NMP/1water, 3NMP/1water, and 9NMP/1water are 2.13, 3.50, and 4.72, respectively. CO2 capacity of EAE/NMP solvent is 2–3.7 times greater than 30 % MEA and 1.2–2 times greater than 30 % PZ.

Assessment of body mass-related covariates for rifampicin pharmacokinetics in healthy Caucasian volunteers

PurposeCurrently, body weight-based dosing of rifampicin is recommended. But lately, fat-free mass (FFM) was reported to be superior to body weight (BW). The present evaluation aimed to assess the influence of body mass-related covariates on rifampicin’s pharmacokinetics (PK) parameters in more detail using non-linear mixed effects modeling (NLMEM).MethodsTwenty-four healthy Caucasian volunteers were enrolled in a bioequivalence study, each receiving a test and a reference tablet of 600 mg of rifampicin separated by a wash-out period of at least 9 days. Monolix version 2023R1 was used for NLMEM. Monte Carlo simulations (MCS) were performed to visualize the relationship of body size descriptors to the exposure to rifampicin.ResultsA one-compartment model with nonlinear (Michaelis–Menten) elimination and zero-order absorption kinetics with a lag time best described the data. The covariate model including fat-free mass (FFM) on volume of distribution (V/F) and on maximum elimination rate (Vmax/F) lowered the objective function value (OFV) by 56.4. The second-best covariate model of sex on V/F and Vmax/F and BW on V/F reduced the OFV by 51.2. The decrease in unexplained inter-individual variability on Vmax/F in both covariate models was similar. For a given dose, MCS showed lower exposure to rifampicin with higher FFM and accordingly in males compared to females with the same BW and body height.ConclusionOur results indicate that beyond BW, body composition as reflected by FFM could also be relevant for optimized dosing of rifampicin. This assumption needs to be studied further in patients treated with rifampicin.

PSIII-4 Evaluating the variability of the dual sugar absorption test as a measure of intestinal permeability in pigs

Abstract The intestinal barrier of pigs can be compromised by many factors including health challenges, off-feed events, and environmental stressors. If dysregulated barrier function is caught early, proper treatment can be initiated to potentially prevent more severe complications to overall health. However, there are few procedures to measure intestinal function in pigs that are both validated, sensitive, and minimally invasive. In this research, the dual sugar test using lactulose and mannitol was conducted on a total of 534 pigs of varying age, sex, body weight (BW), and health status. Each pig received the same oral dose of 500 mg/kg body weight lactulose and 50 mg/kg BW mannitol, and blood was collected either 60 or 240 min following the dose. Plasma concentrations of lactulose and mannitol were quantified by high performance liquid chromatography using validated methods. The ratio of lactulose to mannitol absorption (L:M) served as the indicator of barrier function such that a larger L:M ratio was indicative of greater intestinal permeability. In these pigs, L:M ratios ranged from 0 to 6.96. The median L:M ratio was 0.41 while the average was 0.70, indicating that the distribution of the data was right skewed, influenced by 21.0% of pigs exhibiting a L:M of 0. Collecting blood sooner after oral gavage yielded better detectability as only 2.71% of L:M in pigs from the 60 min group was 0 compared with 43.5% from the 240 min group. Ostensibly, an L:M ratio of 0 is biologically relevant, but interpretation of such values is challenging both from statistical and biological perspectives. Intestinal barrier permeability, absorption kinetics between pigs, and delivery efficiency of the L:M solution may all affect lactulose absorption yielding a ratio of 0. In general, the data werewere highly variable, with a standard deviation of 0.95, so a regression analysis was performed to determine which factors may be influencing this variation. Neither a forward nor a backward elimination model determined any of the five explanatory variables (i.e., BW, timing of blood collection, health status, age, or sex) to be significant. Additional correlational analyses further confirmed that there were no significant interactions. Overall, it appears that these factors do not help to explain the variability in the L:M ratio. Further investigation is warranted to validate this process and understand the source and impact of L:M ratios equaling 0.

Determination of CO2 diffusion coefficient in sodium carbonate solutions and implications for decarbonization kinetics

Sodium carbonate solution is a promising carbon capture absorber due to its low cost, rich content, environmental friendliness, and low heat requirement for regeneration, but its large-scale application is limited by its low diffusion coefficient and thus unsatisfied chemical absorption kinetics. Most importantly, the diffusion coefficient parameters of CO2 absorption into sodium carbonate solutions at different concentrations and temperatures are lacked in the existing literature, which leads to a certain bias in the understanding of its absorption kinetics. Based on this, in this paper, a molecular dynamics simulation method was used to calculate the diffusion behavior of CO2 in sodium carbonate solution at different parameters and compared with the existing fitting equations in the literature. The data calculated from literature presented a severe overestimation of diffusion coefficient in low temperature solvent, underestimation of diffusion coefficient in high temperature solvent. The maximum deviation between our simulated data and calculated data of fitted formula in literature exceeded 30%. Based on this, a new fitting formula was proposed in this paper using the temperature adjusted method. The results showed that the maximum error between simulated data and fitted new formula is 24.82%, AARD, SD, RMSD are only 9.21%, 11.13%, and 11.15% respectively. The maximum absolute error was 11.73%, AARD, SD, RMSD are only 4.55%, 5.53%, and 5.53% for CO2 mass transfer kinetics calculation, which significantly contributes to the accuracy of carbon capture process calculations.

Biodistribution of Native and Nanoformulated Innate Defense Regulator Peptide 1002.

Innate defense regulator-1002 (IDR-1002) is a synthetic peptide with promising immunomodulatory and antibiofilm properties. An appreciable body of work exists around its mechanism of action at the cellular and molecular level, along with its efficacy across several infection and inflammation models. However, little is known about its absorption, distribution, and excretion in live organisms. Here, we performed a comprehensive biodistribution assessment with a gallium-67 radiolabeled derivative of IDR-1002 using nuclear tracing techniques. Various dose levels of the radiotracer (2-40 mg/kg) were administered into the blood, peritoneal cavity, and subcutaneous tissue, or instilled into the lungs. The peptide was well tolerated at all subcutaneous and intraperitoneal doses, although higher levels were associated with delayed absorption kinetics and precipitation of the peptide within the tissues. Low intratracheal doses were rapidly absorbed systemically, and small increases in the dose level were lethal. Intravenous doses were rapidly cleared from the blood at lower levels, and upon escalation, were toxic with a high proportion of the dose accumulating within the lung tissue. To improve biocompatibility and prolong its circulation within the blood, IDR-1002 was further formulated onto high molecular weight hyperbranched polyglycerol (HPG) polymers. Constructs prepared at 5:1 and 10:1 peptide-to-polymer ratios were colloidally stable, maintained the biological profile of the peptide payload and helped reduce red blood cell lysis. The 5:1 construct circulated well in the blood, but higher peptide loading was associated with rapid clearance by the reticuloendothelial system. Many peptides face pharmacokinetic and biocompatibility challenges, but formulations such as those with HPG have the potential to overcome these limitations.