Retention Parameters Research Articles

How Scheduled Maintenance Affects Anaerobic Digester Supervision Through Modelling: A Practical Approach

Anaerobic digestion plays a crucial role in the transition toward a circular economy. Incorporating system supervision through mathematical modelling can enhance control and resilience. This study aims to assess the impact of scheduled digester maintenance on the effectiveness of modelling as a tool for monitoring and control. Data from a pilot-scale plug-flow digester were analyzed using an adapted ADM1 model. The maintenance involved halting the digester and removing sedimented solids. Model calibration indicated solid retention in the first two zones of the reactor, while the hydrolysis coefficient and biogas potential remained at 0.122 d−1 and 100.4 mL CH4/gVS, respectively. The average biogas production decreased from 156 to 109 mL/gVS pre- and post-maintenance. Simulations showed a decline in the model’s predictive accuracy after maintenance. To improve model fit, the initial conditions, solids retention, and kinetic parameters were adjusted. Optimal performance was achieved with khyd at 0.045 d−1 and B0 at 52.28 mL gVS−1, revealing an issue with the digester’s heating system. In conclusion, maintenance can significantly alter digester conditions, requiring model recalibration to maintain its effectiveness as a digital copilot for process supervision.

Coupled Hydrogeophysical Modeling to Constrain Unsaturated Soil Parameters for a Slow‐Moving Landslide

AbstractGeophysical methods have proven to be useful for investigating unstable slopes as they are both non‐invasive and sensitive to the spatial distribution of physical properties in the subsurface. Of particular interest are the links between electrical resistivity and near‐surface moisture content; recent work has demonstrated that it is possible to calibrate hydrological models using geophysical measurements. In this study we explore the use of in‐field electrical resistivity data for calibrating unsaturated soil retention parameters and saturated hydraulic conductivity used for modeling unsaturated fluid flow. We study a synthetic case study, and a well‐characterized site in the northeast of England and develop an approach to calibrate retention parameters for a mudstone and a sandstone formation, the former being an actively failing unit. Petrophysical relationships between electrical resistivity and moisture content (or saturation) are established for both formations. 2D hydrological models are driven by effective rainfall estimations; subsequently these models are coupled with a geophysical forward model via a Markov chain Monte Carlo approach. For the synthetic case, we show that our modeling approach is sensitive to the moisture retention parameters, while less so to saturated hydraulic conductivity. We observe the same characteristics and sensitivities for the field case, albeit with a greater data misfit. Further hydrological simulations suggest that the slope retained high moisture contents in the months preceding a rotational failure. Therefore, we propose that coupled hydrological and geophysical modeling approaches could aid in enhancing landslide monitoring, modeling, and early warning efforts.

Sorption experiments as efficient as possible: Mini-column experiments (MCE) using HPLC-ICP-MS coupling with a new data analysis approach to determine sorption parameters

To quantify retention and sorption parameters, diffusion-, batch- or column experiments are common practice. However, these are either not close to nature, extremely time-consuming or material intensive. A promising approach to eliminate these problems is the performance of mini-column experiments (MCE). Due to dynamic retention and realistic solid–liquid ratios, these are close to nature and resource-efficient. The aim of this work is to perform highly controllable MCE using a HPLC (high-performance liquid chromatography) system and HPLC-ICP-MS (inductively coupled plasma mass spectrometry) coupling. With this approach, ultra-fast sorption experiments are possible only using 100–150 mg adsorbent and 160 mL eluent. That means, sorption experiments are even more time- and cost-efficient and also more controllable than with conventional methods. The presented method is based on a newly developed MCE-HPLC-ICP-MS coupling, which was applied to investigate the sorption of Eu(III) on kaolinite and sand in 10 mM NaCl. With that it was possible to carry out dynamic sorption experiments in just 5–15 h and thus determine e.g. maximum loading capacity (qmax) in a very short amount of time. Furthermore, a quantification method for eluates of high ionic strength is presented. Here, the sorption of Cs(I) on calcium silicate hydrate (C-S-H) phases in 10 mM and 100 mM NaCl was investigated. For validation, the sorption distribution ratios (Rd) obtained were compared with those from batch experiments. These agreed very well with each other and with those from the literature. Overall, with MCE more sorption parameters can be determined much faster, more accurately and more efficient than with the conventional methods.

Immobilised artificial membrane liquid chromatography vs liposome electrokinetic capillary chromatography: Suitability in drug/bio membrane partitioning studies and effectiveness in the assessment of the passage of drugs through the respiratory mucosa

This study pioneers a comparison of the application of biomimetic techniques, immobilised artificial membrane liquid chromatography (IAM LC) and liposome electrokinetic capillary chromatography (LEKC), for the prediction of pulmonary drug permeability. The pulmonary absorption profiles of 26 structurally unrelated drug-like molecules were evaluated using their IAM hydrophobicity index (CHI IAM) measured in IAM LC, and the logarithm of distribution constants (log KLEKC) derived from the LEKC experiments. Lipophilicity (phospholipids) parameters obtained from IAM LC and most LEKC analyses were linearly related to the n-octanol/water partitioning coefficients of the neutral forms (i.e., log Po/w values) to a moderate extent. However, the relationship with distribution coefficients at the experimental pH (7.4) (i.e., log D7.4) were weaker overall for IAM LC data and sigmoidal for some liposome compositions (phosphatidyl choline (PC): phosphatidyl inositol (PI) 85:15 mol% and 90:10 mol%) and concentrations (4 mM) in LEKC. This suggests that phospholipid partitioning supports both hydrophobic and electrostatic interactions occurring between ionised drugs and charged phospholipid moieties. The latter interactions are original when compared to those taking place in the more established n-octanol/water partitioning systems.A stronger correlation (R2 > 0.65) was identified between the LEKC retention parameters, and the experimental apparent lung permeability (i.e., log Papp values) as opposed to the values obtained by IAM LC. Therefore, LEKC offers unprecedented advantages over IAM LC in simulating cell membrane partitioning processes in the pulmonary delivery of drugs. Although LEKC has the advantage of more effectively simulating the electrostatic and hydrophobic forces in drug/pulmonary membrane interactions in vitro, the technique is unsuitable for analysing highly hydrophilic neutral or anionic compounds at the experimental pH. Conversely, IAM LC is useful for analysing compounds spanning a wider range of lipophilicity. Its simpler and more robust implementation, and propensity for high-throughput automation make it a favourable choice for researchers in drug development and pharmacological studies.

Synthesis, in vitro anticancer activity, and pharmacokinetic profiling of the new tetrahydropyrimidines:Part I.

Different vanillin-based aldehydes were used to synthesize novel tetrahydropyrimidines (THPMs) via conventional Biginelli reaction. The THPMs were tested against human normal cells (MRC-5) and cancer cell lines (HeLa, K562, and MDA-MB-231). With IC50 values of 10.65, 10.70, and 12.76 µM, compounds 4g, 4h, and 4i exerted the strongest cytotoxic effects against K562 cells. The best activity was achieved for 4g on MDA-MB-231 cells (IC50 = 9.20 ± 0.14 µM). The effects of compounds 4g, 4h, and 4i on the cell-cycle phase distribution of K562 cells were analyzed. Principal component analysis was carried out for the chemometrics analysis to comprehend the relationship between the anticancer activity of the THPMs, pharmacokinetic properties, and partition coefficients, as well as the relationship between the chromatographic behavior and retention parameters. The highest retention rates are found for molecules 4g, 4h, and 4i, which have the longest carbon chains, indicating that the length of the alkyl chain positively affects the molecule's anticancer activity but only if the number of carbon atoms is not higher than seven. Additionally, molecular docking analysis was performed to determine the preferred binding modes of the investigated ligands (4g, 4h, and 4i) with a DNA dodecamer and bovine serum albumin.

Preparation and Characterization of Supramolecular Bonding Polymers Based on a Pullulan Substrate Grafted with Acrylic Acid/Acrylamide by Microwave Irradiation

A microwave technique was used to prepare a superabsorbent polymer (SAP) by grafting two hydrophilic monomers onto a polysaccharide substrate. The monomers used were acrylic acid (AA) or acrylamide (AM) and were grafted onto a pullulan (PUL) substrate to form PUL-g-AA (SAP1) and PUL-g-AM (SAP2), respectively. The monomers (AM/AA) were grafted together onto a PUL substrate to form PUL-g-(AM/AA) (SAP3). Grafting parameters such as grafting efficiency with the percentage, the conversion of monomer into polymer, gel content, water retention, water adsorption capacity, and swelling kinetics were determined. Additionally, the effect of environmental pH (2, 4, 7, 9, and 12) and sodium dodecylbenzene sulfonate (SDBS) surfactant was evaluated, where 1, 2, 3, 4, and 5 mM of SDBS was added to form SAP4 to SAP8. The FTIR results show that AM was grafted onto PUL through an aliphatic C-N bond, while AA grafting occurred through a single C-C bond. The grafting efficiency with AM was higher than with AA, as well as showing a superior gel content. Water absorbance capacity and water retention increased with the grafting of AA and AM together for SAP3. The highest absorbent capacity, water retention, gel content, and grafting parameters values were obtained with a 3 mM SDBS content and a pH of 7. The swelling kinetics showed that the increases in the theoretical and experimental swelling equilibriums were 72% and 82%, respectively, for SAP6 compared to the values of these parameters for SAP3. The water absorption capacity of the hydrogel increases upon increasing the pH to 7 and then gradually decreases. XRD demonstrated the improved crystallinity and crystalline size of the hydrogel after grafting polymerization of AM/AA onto PUL, in addition to enhanced thermal stability. On the contrary, FE-SEM demonstrated that SDBS improves the porosity and pore size of the hydrogel surface with SAP6.

Fullertubes: A 30-Year Story of Prediction, Experimental Validation, and Applications for a Long-Missing Family of Soluble Carbon Molecules.

ConspectusDuring the last 30 years, theoretical scientists imagined segmental families of monolayer carbon tubules with fullerene-based end-caps. These fullertube molecules would possess structural features of both fullerenes (hemispherical end-caps) and tubular belts of single-walled carbon nanotubes (SWCNTs). Yet, their experimental verification remained elusive for decades. It was not until 2020-2023 that segmental families of fullertubes were finally confirmed in the lab. The shocking irony is that these fullertubes were unwittingly coproduced alongside fullerenes (e.g., C60, C70, C84) in both flame and electric arc soot since the 1990s. Yet, nobody knew these "hidden" families of fullertubes were experimentally present in their extracted soot due to their low abundance and the absence of isolation methodology.This eruption of fullertube discoveries in 2020-2023 was brought to fruition by structural data, both DFT and experimental. This "Treasure Trove" of new molecules during this four-year window occurred with only microgram quantities. Typically, milligram levels of purified samples are required for X-ray crystallography and 13C NMR structural analysis. The breakthrough for experimentally verifying the missing fullertubes was an aminopropanol reagent to selectively react with and remove spheroidal carbon (e.g., C60, C70, C84) as hydrophilic derivatives. In contrast, there was suppressed reaction with fullertubes, which remained in organic solvent. It is well established that high symmetry (3-, 5-, and 6-fold) hemispheres for C60-Ih and other fullerenes and metallofullerenes are prerequisite end-caps for fullertubes. For the case of [5,5] C130 fullertubes, this requirement results in only eight 3-, 5-, and 6-fold symmetry structural isomers possible from a total of 39,393 possible isolated pentagon rule (IPR) isomers. From this C130 list of 8 candidate isolated pentagon rule (IPR) high symmetry isomers, surprisingly only one structure matched the DFT polarizability versus chromatographic retention parameter (a new gold standard for isomer identification). The simultaneous emergence of DFT computations of other properties (e.g., total energy, HOMO-LUMO gap, UV-vis) for large carbon molecules provided support for structural determination. Experimental approaches (e.g., mass spectrometry, UV-vis, XPS, Raman, and STEM) provided additional layers of structural elucidation at the microgram level. For the first time, we developed a chemical isolation protocol that would allow the preparation and isolation of soluble pristine fullertubes in the range of C90-C200. To date, applications of SWCNTs for use in nanoscale computer applications requires purities greater than 99.999%. Although this stringent mandate has not yet been demonstrated using SWCNT samples, this high level of purity appears achievable for metallic [5,5] D5d-C120 and semiconductor [10,0] D5h-C120 [10,766] fullertubes. Moreover, commercial production of pristine fullertubes should easily be feasible by the flame method due to its continuous operation and inexpensive feedstock. For application development, theoretical and electrochemical experimental data show that fullertubes exhibit high catalytic activity in oxygen reduction reactions. In the medical sector, pristine fullertube dispersions exhibit antimicrobial effects on Mycobacterium smegmatis and M. abscessus.

Advances and Drawbacks of Sous-Vide Technique-A Critical Review.

The sous-vide (SV) technique, notable for its precision and ability to preserve food quality, has become a transformative method in culinary arts. This review examines the technical aspects, applications, and limitations of SV, focusing on its impact on food safety, nutritional retention, and quality parameters across various food matrices such as meats, seafood, vegetables, and semi-prepared products. Through an extensive literature review, the study highlights the use of natural inhibitors and essential oils to enhance microbial safety and explores the nutritional benefits of SV in preserving vitamins and minerals. The findings suggest that while SV offers significant benefits in terms of consistent results and extended shelf life, challenges remain in terms of equipment costs and the necessity for specific training, and although sufficient for food preparation/processing, its effectiveness in eliminating microbial pathogens, including viruses, parasites, and vegetative and spore forms of bacteria, is limited. Overall, the research underscores SV's adaptability and potential for culinary innovation, aligning with modern demands for food safety, quality, and nutritional integrity.

Particle morphology and soil properties affect the retention of copper oxide nanoparticles in agricultural soils.

The interaction between nanoscale copper oxides (nano-CuOs) and soil matrix significantly affects their fate and transport in soils. This study investigates the retention of nano-CuOs and Cu2+ ions in ten typical agricultural soils by employing the Freundlich adsorption model. Retention of nano-CuOs and Cu2+ in soils was well fitted by the Freundlich model. The retention parameters (KD, KF, and N) followed an order of CuO NTs > CuO NPs > Cu2+, highlighting significant impact of nano-CuOs morphology. The KF and N values of CuO NPs/Cu2+ were positively correlated with soil pH and electrical conductivity (EC), but exhibited a weaker correlation for CuO NTs. Soil pH and/or EC could be used to predict KF and N values of CuO NPs or CuO NTs, with additional clay content should be included for Cu2+.The different relationship between retention parameters and soil properties may suggest that CuO NTs retention mainly caused by agglomeration, whereas adsorption and agglomeration were of equal importance to CuO NPs. The amendment of Ca2+ at low and medium concentration promoted retention of nano-CuOs in alkaline soils, but reduced at high concentration. These findings provided critical insights into the fate of nano-CuOs in soil environments, with significant implications for environmental risk assessment and soil remediation strategies.

Transport of reactive contaminant in a wetland flow with the effects of reversible and irreversible reactions on the bed surface

Wetlands are crucial for maintaining biodiversity in ecosystems. The reversible chemical reactions can significantly affect the pollutant reduction capacity in wetland flow. The spatial transport of contaminants in wetlands is further complicated by phase exchange kinetics due to reversible reactions in the wetland bed. This paper provides an analytical solution for studying the multi-dimensional concentration distribution of solutes in wetland flow, considering both reversible and irreversible boundary reactions. Unlike previous one-dimensional studies (Jiang et al. (2022), Zhan et al. (2024)), our approach offers a comprehensive view of wetland contaminant transport, accounting for complex interactions between different phases and environmental factors. The solute may undergo reversible sorptive phase exchange between the immobile (wetland bed phase) and the mobile phase (fluid phase). Multi-scale homogenization methods are used to determine the dispersion coefficient, mean concentration, longitudinal and vertical real concentration distributions, rate of variation of vertical concentration distribution under the influence of vegetation force, and reversible and irreversible reactions at a stationary wetland bed. The effects of retention parameter (θ), Damkohler number (Da), vegetation effect (α), dispersion time (τ), and first-order irreversible boundary reaction (β′) on solute mixing are thoroughly analyzed. The study's analytical results are validated by numerical results obtained using the finite difference method with a Shishkin mesh, and other comparisons are made with the limiting case of Taylor dispersivity. Results show that an increase in Damkohler number and vegetation force weakens contaminant transport in wetland flow, but an increase in Da enhances contaminant concentration in the mobile phase. The presence of reversible phase exchange kinetics causes non-uniform vertical concentration variation across the wetland cross-section. Critical values where the multi-scale homogenization technique may fail are suggested as θ≤0.5 and Da≥1. The study's findings have potential applications to pollution control in wetlands.

PFAS transport under lower water-saturation conditions characterized with instrumented-column systems

The transport of PFOS and PFOA in well-characterized sand was investigated for relatively low water saturations. An instrumented column was used for some experiments to provide real-time in-situ monitoring of water saturation and matric potential. The results showed that water saturations and matric potentials varied minimally during the experiments. Flow rates were monitored continuously and were essentially constant. These results demonstrate that surfactant-induced flow and other nonideal hydraulic processes did not materially impact PFAS transport for the experiment conditions. Air-water interfacial adsorption was demonstrated to provide the great majority of retention for PFOS and PFOA. Retention was significantly greater at the lower water saturations (0.35–0.45) compared to the higher saturations (∼0.66) for both PFAS, due to the larger extant air-water interfacial areas. Retardation factors were 5 and 3-times greater at the lower water saturations for PFOS and PFOA, respectively. Early breakthrough was observed for the PFAS but not for the non-reactive tracers at the lower water saturations, indicating the possibility that air-water interfacial adsorption was rate-limited to some degree. Independently determined retention parameters were used to predict retardation factors for PFOS and PFOA, which were similar to the measured values in all cases. The consistency between the predicted and measured values indicates that PFAS retention was accurately represented. In addition, air-water interfacial adsorption coefficients measured from the transport experiments were consistent with independently measured equilibrium-based values. Based on these results, it appears that the air-water interfacial adsorption processes mediating the magnitude of PFOS and PFOA retention under lower water-saturation conditions are consistent with those for higher water saturations. This provides some confidence that our understanding of PFAS retention obtained from work conducted at higher water saturations is applicable to lower water saturations.

Characterization of reversed-phase liquid chromatographic columns containing positively charged functionality

To date, the most commonly used column characterization databases do not determine the relative positive charge associated with new generation RP columns, or they fail to successfully discriminate between RP columns of purportedly low level positive and neutral characters. This paper rectifies this in that it describes a convenient and robust chromatographic procedure for the assessment of the low levels of positive charge on a range of RP columns. The low degree of positive charge was determined by their electrostatic attraction towards the negatively charged 4-n-octylbenzene sulfonic acid (4-OBSA) relative to their retention of the hydrophobic marker toluene (Tol).The new parameter (α4-OBSA/Tol) was determined for 15 commercially available RP-LC columns. When this was combined with existing Tanaka parameters it was possible to guide the chromatographer towards similar columns as “backup / equivalent phases” or dissimilar columns for exploitation in method development strategies. It should be noted that under certain chromatographic conditions the retention mechanism(s) may be too complex to allow direct location of a “backup / equivalent” column(s).The α4-OBSA/Tol results indicate that even the new generation neutral alkyl phases may exhibit a small degree of positive charge at low buffer concentrations. Mobile phases containing low % MeCN were demonstrated to promote mixed mode (anionic exchange / hydrophobic) retention whereas at high % MeCN anionic exchange retention dominated.The measure of electrostatic repulsion between positively charged columns and positively charged bases was assessed by evaluating the relative retention of a range of bases and neutral analytes. The greatest electrostatic repulsion was observed with hydrophilic bases. While there was no correlation between the positive charge associated with the phases assessed by electrostatic attraction or repulsion, the columns could be broadly divided into three subsets (i.e., significant positive character, medium to low positive character and insignificant positive character).Finally, the results were used to highlight the usefulness of the column characterization database containing the new anionic exchange retention parameter (α4-OBSA/Tol) for the selection of an equivalent column possessing a low level of positive character in the analysis of a real-life biopharmaceutical application.

Maternal and Fetal Prognosis in Pregnant Women with Renal Disease Associating Urinary Tract Infection.

Pregnancy related acute renal injury is a challenging diagnosis, mainly due to, among other factors, the physiological decrease in blood nitrogen retention parameters. As a consequence, the criteria required to establish the diagnosis may be first met as a result of the complications that appear, especially hypertension. The maternal and fetal complications which may occur in pregnancies with renal failure can be worsened by the relative immunodeficiency during pregnancy, which represents an elusive mechanism that is associated with a high risk of urinary tract infection (UTI). Therefore, the risk for intensive care unit admission, or developing sepsis, or preterm birth can increase. The present study aims to investigate whether the superimposition of UTI over an altered renal function leads to a worsened maternal and fetal prognosis. We performed an observational retrospective study that included pregnant women with increased serum creatinine levels, both with and without UTI. Thus, we analyzed 47 pregnant women who delivered in our unit between 1 January 2021 and 1 September 2023. Patients were divided into three groups: an acute renal injury (AKI) group (n=16), a chronic kidney disease (CKD) group (n=8) and a control group (n=23) which included patients with serum creatinine levels between 0.80-1 mg/dL. We evaluated the maternal and fetal complications in all three groups, taking into consideration the comparison between maternal and fetal parameters in women with UTI. Our study highlighted an important difference between fetal weight at delivery by patients with AKI associating UTI and the two remaining groups (1395 ± 992.50 grams compared to 2340 grams in the CKD group and 3103.33±83.86 grams in the control group, respectively). There was no statistically significant difference regarding preterm birth, intrauterine grow restriction, stillbirth or neonatal intensive care unit (NICU) admission. Preterm birth had a higher incidence in all patients with AKI (87.5% compared to 50% and 34.78%, respectively). Neonatal complications are important in pregnant women with AKI and CKD, irrespective of the UTI diagnosis. Most fetal complications occurred in patients diagnosed with AKI. The correlations highlighted by us should be studied further.

#1290 Adverse proinflammatory responses in the kidney after FGF23 administration in three murine kidney disease models

Abstract Background and Aims The hormone FGF23 is a biomarker associated with morbidity and mortality in individuals with and without kidney disease, but the role of FGF23 excess as a pathogenic factor is incompletely understood. Here, we investigated renal FGF23 signaling in kidney disease models. Method This study used three independent disease models: i) Male C57BL/6 mice (n = 16) were treated with Freud's adjuvant and nephrotoxic serum (NTS) to induce anti-glomerular basement membrane (anti-GBM) disease. ii) Female BALB/c mice (n = 8) were treated with adriamycin (doxorubicin) 10.5 mg/kg to induce focal and segmental glomerulosclerosis (FSGS). iii) Male DBA/2J mice (n = 20) were fed a diet containing adenine 0.2%. Control mice of the respective same strain and sex received vehicle injections. Mice of the anti-GBM and FSGS models and controls received intravenous injections of recombinant FGF23 1 µg or vehicle for six consecutive days (anti-GBM) or once (FSGS), with dissection 24 h after the last injection. Mice of the adenine model were dissected after 15 weeks. Following dissection, ex vivo precision-cut kidney slices (PCKS) were obtained from n = 4 mice and maintained for 24 at 37°C, 95% O2 and 5% CO2, followed by a 1 h treatment with recombinant FGF23 200 ng/ml or vehicle. Glomerular filtration rate (GFR) or renal retention parameters in serum and albuminuria were assessed. Kidneys underwent histological assessment using hematoxylin & eosin or Masson's trichrome. Renal RNA was isolated for bulk RNAseq. Differential gene expression was assessed to determine the effect of FGF23 treatment in disease-free controls, in each disease model, and the interaction between FGF23 X disease effect for the anti-GBM and FSGS groups. Gene set enrichment analysis was performed with a focus on the immune system. Results Anti-GBM mice showed a 45 ± 27% GFR decline (mean ± SD) compared to baseline, whereas controls showed an GFR increase of 11 ± 36% (p < 0.01). Kidney histology revealed an interstitial infiltrate. The FSGS model showed elevated serum creatinine and albuminuria, and hypercellularity in some glomeruli. Mice of the adenine model showed progressively increased blood urea nitrogen concentrations starting after 2 weeks, up to a 3-fold increase at week 14. Histology revealed interstitial fibrosis and tubular atrophy. Bulk RNAseq revealed proinflammatory transcriptional signatures after FGF23 treatment in all disease models, regardless of which timepoint or model: In the anti-GBM model, Hallmark gene sets of inflammatory response, interferon-α response, interferon-β response and allograft rejection were significantly increased after 6 days of FGF23 treatment, whereas disease-free controls showed no significantly changed immune gene sets after 6 days of FGF23. In FSGS mice, none of the Hallmark gene sets were changed after 1 FGF23 injection, but top individual gene expression affected by 1 FGF23 injection were an increased proinflammatory transcription factor Cebpb and an increased DNA damage transcript Dclre1b. Finally, the PCKS of adenine model revealed no significant Hallmark gene sets, but the two genes with differential expression were a proinflammatory macrophage/fibroblast chemokine Ccl4 (increased) and an immunoglobulin heavy variable Ighv2-2 (decreased). Conclusion FGF23-driven patterns of proinflammatory gene expression were observed in three experimental models of kidney disease, both in vivo and ex vivo assessment of FGF23 signaling, thus excluding effects of FGF23 on other organs. As these findings were limited to transcriptional analyses, the present data warrant further confirmation and exploration of FGF23 as a pathogenic agent in kidney disease.

Developing novel ensemble models for predicting soil hydraulic properties in China’s arid region

Accurately quantifying the mass (water, nutrients, and carbon) and energy exchange processes between the Earth’s atmosphere, biosphere, and lithosphere requires the accurate parameterization of soil hydraulic properties (SHPs) and their spatial heterogeneity. Because direct measurements of SHPs are difficult, time-consuming, and impossible at larger spatial scales, various pedotransfer functions (PTFs) have been developed in the last few decades, providing divergent estimates of SHPs from readily measurable variables. However, existing PTFs are mostly developed for specific regions and may not be suitable for other pedoclimatic conditions. Here, PTFs were developed using multiple machine-learning algorithms to estimate SHPs and examined the weaknesses and strengths of each method in estimating the average and variability of SHPs across China’s arid region. The optimal PTFs were applied to a 1 × 1 km2 regional map of texture and bulk density, thus producing maps of the saturated hydraulic conductivity (Ks), the parameters of the van Genuchten (VG) formulation, field capacity (θfc), wilting point (θwp), plant available water (θpa), and soil macroporosity (ϕm) in the 0–2 m soil profile throughout the region. The results indicate that the ensemble model with the averaging method (EMA) is the most robust for estimating all SHPs. The EMA-PTFs for Ks yielded the best performance for sand textures, followed by sandy loam, loam, silty loam, silty clay loam, loamy sand, and clay loam textures. There were no significant differences in estimating soil water retention curve parameters among the different soil texture classes. Using the same observed data set, we demonstrated that the new EMA-PTFs outperformed those of existing PTFs, such as Rosetta and HYPRES, with RMSE values decreasing by 25–83 % depending on the SHPs. Furthermore, our SHP datasets exhibited significantly deeper soil profiles and higher accuracy than other available regional and global SHP products. The VG retention parameter α shows the greatest variation vertically throughout the 0–2 m soil profile, followed by ln(Ks), θr, θpa, θfc, θwp, ϕm, θs and n. All SHPs exhibit much lower variability in the desert than in other areas, likely due to the homogeneous particle size distribution of desert areas. This study provides more accurate SHP estimates in China’s arid region than the existing SHP products by developing advanced PTFs and highlights the inconsistency in SHPs among different global or regional products; the uncertainties induced by PTFs should thus be considered in future terrestrial biosphere modeling.

Analysis of scopolamine and its related substances by means of high-performance liquid chromatography

AbstractThe retention behaviour of scopolamine (hyoscine) and its related compounds (norhyoscine, atropine, homatropine, and noratropine) was investigated on the silica-based HPLC stationary phase. The retention of investigated tropane alkaloids was interpreted by using the Soczewiński-Wachtmeister equation. A high correlation between the retention parameter (log k) and lipophilicity (log P) (R = 0.9923) confirms the significant influence of hydrophobic interactions on the retention behaviour of the aforementioned compounds. It was found that by increasing the acetonitrile fraction, a decrease in retention of the more polar epoxide derivatives (scopolamine, norhyoscine) and an increase in retention of the more lipophilic derivatives (atropine, noratropine, homatropine) is obtained. The best separation of the tropane alkaloids was achieved by a simple procedure that involved a mobile phase composed of acetonitrile and 40 mM ammonium acetate/0.05% TEA, pH 6.5; 50:50 v/v. Selected conditions were assumed for the determination of scopolamine hydrochloride in the eye drops (Scopolamini hydrobromidum 0.25%). The method was validated and it was found as selective, sensitive, precise, accurate, and robust for the further qualitative analysis of the scopolamine-related compounds.

260 Effect of different doses of phytase (HiPhorius) and two primary calcium sources on nutrient digestibility, retention and blood parameters in weaned piglets

Abstract An 18-d study evaluated the effect of increasing phytase levels in diets with limestone or Ca-formate on Ca and P digestibility, P retention, and blood inositol, Ca, and P in weaned piglets. At weaning, male piglets [n = 60; 29.8 ± 1.10 d of age; initial body weight (BW) = 8.8 ± 0.31 kg) were randomly allocated to ten diets formulated as a 2 × 5 factorial design with 2 primary Ca sources (limestone or Ca-formate) and 5 Ca/P levels. There was a positive control diet (PC; 0.76% Ca, 0.34 dP) and 4 negative control diets (NC; 0.56% Ca, 0.34% dP) supplemented with phytase at 0, 750, 1,500, and 3,000 FYT/kg. At d 10, piglets were individually housed in metabolism crates and fed 3.2 x metabolic weight. On d 14 to 18, fecal and total urine samples were collected. Apparent total tract digestibility (ATTD) was calculated for dry matter (DM), organic matter (OM), crude protein (CP), ash, Ca, and P using TiO2 as marker. Urinary P was measured to calculate P retention. These data were analyzed as a 2-way interaction. On d 0 (baseline), 8 and 18, blood samples were collected to analyze serum Ca and P, and plasma inositol. Blood data were analyzed as a 3-way interaction. Results indicated that piglets fed Ca-formate had greater ATTD of Ca (75.0% vs. 71.4%, P < 0.01) but decreased ATTD of P (66.4% vs. 68.8%, P < 0.01), than piglets fed limestone. Phytase supplementation improved ATTD of DM, ash, OM, CP, P, and Ca compared with the NC and PC. An interaction between Ca/P levels and Ca-sources was observed for urinary P (P = 0.03), as there were no differences between Ca sources in piglets fed the NC or the 750 FYT diets, but piglets fed the PC diet and the NC+1,500 or 3,000 FYT with limestone had greater urinary P compared with Ca-formate. A 2-way interaction between Ca/P levels and d was observed for plasma inositol (P = 0.012). On d 8 and 18, there was no difference between the NC and PC;, however, phytase supplementation at 750, 1,500, and 3,000 FYT increased plasma inositol on d 8 (58.2, 80.7, and 89.5 μmol) and d 18 (70.2, 85.4, and 106.4 μmol). There was only a main effect of Ca/P levels in serum P. Compared with the NC (73.7 mg/L), the PC and the NC+750, 1,500, and 3,000 FTU/kg increased serum P (90.3, 89.1, 87.6, and 93.2 mg/L, respectively, P < 0.01). There was no effect of Ca source on blood inositol and P. No significant dietary treatment effects were observed in serum Ca. In conclusion, using Ca-formate instead of limestone increases Ca digestibility but reduces P digestibility, likely due to a greater Ca solubility of Ca-formate. This suggests that diets should be formulated based on digestible Ca instead of total Ca.

Relation between characteristic temperature and elution temperature in temperature programmed gas chromatography – Part II: Influence of column properties

The method development process in gas chromatography can be accelerated by suitable computer simulation tools using knowledge about the solute-column interactions described by thermodynamic retention parameters. Since retention parameters usually are determined under isothermal conditions, the presented work offers a step to estimate one of the most important retention parameters, the characteristic temperature Tchar by less laborious temperature programmed measurements.In the first part an empirical multivariate model was introduced describing the correlation between the elution temperature Telu of a solute and its characteristic temperature Tchar. Now in the second part a simulation model of GC and available retention data from a retention database was used to investigate the correlation between Telu and Tchar for an expanded range of heating rates and initial temperatures. In addition to part I, the simulation is used to investigate the influences of different properties of the separation column such as different phase ratios and column geometries like length and diameter or various stationary phases including SLB-5 ms, SPB-50, Stabilwax, Rtx-Dioxin2, Rxi-17Sil MS, Rxi-5Sil MS, ZB-PAH-CT, DB-5 ms, Rxi-5 ms, Rtx5 and FS5ms. The fit model is valid for all investigated stationary phases. The influence of the phase ratio to the correlation could be determined. Therefore, the model was expanded to this parameter.The expanded range of heating rates and the normalization for the system independent dimensionless heating rate required a further modification of the previously presented correlation model. The model now fits also under isothermal conditions. The results were used for estimation of the Tchar of an analyte from the elution temperature in the temperature program. The prediction performance was investigated and evaluated for 20 different temperature program conditions and at two phase ratios (β=125 and β=250). Under best conditions the estimated and the measured Tchar values show relative differences <0.5 %. With this novel model estimations for Tchar are possible at 20 °C above the initial temperature, which expands the prediction range even for low and medium retained analytes compared to earlier approaches.

Tamarind seed polysaccharide-metformin insert: Higher ocular retention, slow-release, and efficacy against corneal burn

Metformin (MET) can be an alternative therapeutic strategy for managing ocular burn primarily because of its pleiotropic mechanism. Longer retention on the ocular surface and sustained release are necessary to ensure the efficacy of MET for ocular application. Although the high aqueous solubility of MET is good for formulation and biocompatibility, it makes MET prone to high nasolacrimal drainage. This limits ocular residence and may be a challenge in its application. To address this, polymers approved for ophthalmic application with natural origin were analyzed through in silico methods to determine their ability to bind to mucin and interact with MET. An ocular insert of MET (3 mg/6 mm) was developed using a scalable solvent casting method without using preservatives. The relative composition of the insert was 58 ± 2.06 %w/w MET with approximately 14 %w/w tamarind seed polysaccharide (TSP), and 28 %w/w propylene glycol (PG). Its stability was demonstrated as per the ICH Q1A (R2) guidelines. Compatibility, ocular retention, drug release, and other functional parameters were evaluated. In rabbits, efficacy was demonstrated in the 'corneal alkali burn preclinical model'. TSP showed potential for mucoadhesion and interaction with MET. With adequate stability and sterility, the insert contributed to adequate retention of MET (10–12 h) in vivo and slow release (30 h) in vitro. This resulted in significant efficacy in vivo.

Clinical and Paraclinical Features in Pregnancies Associated With Renal Impairment Due to Hypertensive Complications.

Background An association between renal impairment and hypertensive complications occurring during pregnancy has been shown in a limited number of studies. As a consequence of a lack of clear criteria for diagnostic certainty, acute renal failure during pregnancy is a challenging pathology to diagnose, mainly due to the physiological reduction of nitrogen retention parameters. In light of the fact that renal injury is associated with a poor maternal and fetal prognosis, this study aims to determine the maternal demographic features and the cut-off of serum creatinine that can lead to a heightened risk of prematurity, stillbirth, intrauterine growth restriction, or the necessity of neonatal intensive care. Methods We performed a study that included a cohort of 45 pregnant women with acute renal injury who delivered in the Department of Obstetrics and Gynecology of the University Emergency Hospital in Bucharest between January 1, 2017, and December 31, 2022, a cohort of 45 pregnant women with a value of serum creatinine between 0.8 and 1 mg/dL, and a cohort of 45 pregnant women, selected at random, with a value of serum creatinine under 0.8 mg/dL, who delivered in the same period in the aforementioned unit. The analysis included neonatal outcomes (preterm birth, intrauterine growth restriction, stillbirth, Apgar score calculated at one minute, the need for neonatal intensive care), maternal demographic features, medical and obstetrical history, and paraclinical parameters. Results The incidence of acute renal injury was 0.33% for the entire cohort of patients who gave birth in our hospital. Out of that lot, 65.21% of the cases of acute renal impairment associated with pregnancy were caused by hypertensive complications. The mean age of patients with acute kidney injury (AKI) was 29.4 ± 6.66, preponderantly primiparous. The majority of the neonates from patients with AKI (62.22%) were born with a birth weight under 2.500 grams. Preterm deliveries were preponderant (66.66%) in patients with AKI, while in the control group, the incidence of preterm deliveries was 48.88%. Stillbirth in the AKI group had an incidence of 13.33%, while in the control group, there were none. Due to these neonatal complications, most of the newborns in the AKI group needed neonatal intensive care. An important percentage of the patients who developed AKI (40%) did not benefit from proper medical care during pregnancy or before admission to our unit. The cutoff of 1.09 mg/dL of serum creatinine level was established following receiver operating characteristic curve analysis. Conclusion AKI during pregnancy is associated with hypertensive disorders, low birth weight, and preterm deliveries.