Relative Retention Research Articles

A novel indicator to assess PIT tag retention in an aquatic amphibian: impact of body size

The comprehensive study of organisms is often hindered by the difficulty of consistently capturing, detecting, and tracking all life stages and age classes. This challenge is particularly pronounced for aquatic amphibians such as Siren intermedia (lesser siren), which can aestivate underground in dry burrows during extended droughts. In addition, obtaining year-round data on the habitat use, occupancy, and movement ecology of S. intermedia is notably difficult due to their cryptic nature, mobility, aestivation behaviors, trap-shy habits, and the impracticality of outfitting hatchlings and small juveniles with telemetry devices like subcutaneous Passive Integrated Transponder (PIT) tags. Moreover, there is the lack of a non-physical method to distinguish retained tags from those that have been dropped. In this study, we developed a novel indicator to assess the field retention status of PIT tags inserted into the tail tissue of S. intermedia. This was achieved by analyzing individual spatial redetection patterns of 8- and 12-mm PIT tags inserted into juveniles and adults, respectively, over 2 years in a remnant Cypress–Tupelo swamp wetland complex in southern Illinois, using systematic dipnetting, trapping, and PIT scanning telemetry surveys. Tags were considered dropped if the average distance between subsequent scanned PIT detections after the first redetection was ≤ 5 m and if the distance between the second detection and final redetection location was also ≤ 5 m. We then examined PIT tag retention in relation to initial body size and marking parameters. Ultimately, 29% of the 8-mm PIT tags initially injected into juveniles with tail lengths (Tail) 46–84 mm were redetected at least once. Using our spatial–temporal PIT telemetry indicator, we found that 45% of the redetected PIT tags had been dropped by juveniles. In contrast, all three of the 12-mm tagged adults were redetected at least once, with movement patterns indicative of tag retention. Our findings suggest that 8-mm PIT tags are likely to be expelled from juvenile S. intermedia with a mean ± standard deviation (SD) Tail of 50.2 ± 2.8 mm. This study underscores the importance of determining appropriate size requirements and cutoffs for effective telemetry device application across different age classes of a species.

In-situ aqueous phase encapsulation immobilized lipase assisted by acidic ionic liquids for the synthesis of isoamyl acetate

In this study, two acidic ionic liquids were innovatively selected to replace traditional acetic acid as catalysts and templates for the preparation of covalent organic frameworks (COFs) materials in aqueous phase at room temperature. At the same time, the synthesized COFs carrier achieved in-situ encapsulation and immobilization of Candida rugosa lipase (CRL) in aqueous phase at room temperature. The optimum immobilized lipases COF-COOH-M and COF-SO3H-M were obtained by adjusting the reaction conditions. Their enzyme loadings were 210.17 mg/g and 258.47 mg/g, respectively, and the specific activity retention compared to free lipase was 67.11% and 78.42%, respectively. The carrier and immobilized lipase were characterized by FT-IR, XRD, BET and TG. The catalytic performance and operational stability of the immobilized lipase were investigated. The results showed that both immobilized lipases showed better stability than free lipases, and COF-SO3H-M had the best performance. The relative activity retention of COF-SO3H-M after incubation at 60 °C for 60 minutes was 4.35 times that of free lipase. After 28 days of storage at 4 °C, the relative activity of COF-SO3H-M remained 75.10%, while that of free lipase was only 24.61%. The COF-SO3H-M was applied as biocatalyst for isoamyl acetate preparation at 50 °C for 7 hours, and the yield of isoamyl acetate was as high as 86.94%, which was 22.12% higher than that of free lipase.

Identification and Structural Characterization of Novel Process‐Related Impurities Present in Oseltamivir Phosphate Drug Substance and Its Precursor

ABSTRACTThis article describes the identification, synthesis, and characterization of unknown impurities present in the oseltamivir phosphate drug substance and its precursor. Four unknown impurities were identified in the drug substance using high‐performance liquid chromatography analysis: Relative retention times of 1.05 and 2.50 azide impurities were found in the drug substance's precursor, and their corresponding impurities were found in the drug substance in amine form. Initially, the LC‐MS method was used to screen these impurities by identifying the mass of the impurities. Based on the impurities' mass and the drug substance's synthesis route, possible ways to form impurities were predicted. All these impurities were synthesized as predicted and characterized through infrared spectroscopy, nuclear magnetic resonance, and high‐resolution mass spectrometry techniques. It was found that these impurities are new and the synthesis method for these impurities is novel and has not been documented in the literature. The azido‐impurities found in this study are categorized as genotoxic impurities by Class 3 of the International Council for Harmonisation M7(R2) criteria, and these impurities must be regulated below certain thresholds.

Multiple fingerprinting and chromatography-immunoreactivity relationship of polysaccharides from Dioscorea opposite Thunb

The quality evaluation of Dioscorea opposite Thunb. mainly focuses on determining water-soluble contents. Polysaccharides are now recognized as the significant constituents of yam with activities such as immune enhancement, and it is necessary to use polysaccharides as an indicator for quality control of yam in this study. Sixty batches of yam polysaccharides were obtained by conventional hot water extraction and analysis for their physicochemical properties and structure. The results showed the functional groups (four shared peaks including 3500–3300 cm−1) and molecular weights (2.06 × 103 Da-2.28 × 103 Da). The PMP-HPLC fingerprints calibrated 5 familiar peaks, and the relative retention times of each characteristic peak to the Glc peak (S peak) were 0.47 (Man), 0.86 (GalA), 1.00 (Glc), 1.13 (Gal), 1.24 (Ara), Glc and Gal, which were the main differentiated monosaccharide components in the HPLC fingerprinting of YPs. This study provided a preliminary data reference for quality control of YPs.

Social Media Marketing and Performance of Small and Medium-Sized Enterprises in South West Nigeria

The study investigated how small and medium-sized businesses (SMEs) in southwest Nigeria performed in terms of brand awareness, customer satisfaction, customer retention, and customer patronage in relation to social media marketing (ad placement, content marketing, referral marketing, and influencer marketing). The moderating effects of trust on SMEs' performance were also investigated in this study. Using a cross-sectional research methodology, the study used multistage sampling strategies, such as purposive, proportional, and simple random sampling. In all, 383 SMEs' owners and managers were chosen from the states of Ekiti, Ondo, and Oyo. Social media marketing significantly improved brand awareness, customer satisfaction, customer retention, and consumer patronage, according to the research. Additionally, the results showed that trust significantly moderated the performance of the chosen SMEs. According to the study's findings, social media marketing significantly impacted the performance of SMEs. According to the survey, SMEs should create a thorough social media marketing plan that includes a range of techniques like ad placement, content marketing, influencer marketing, and referral marketing. These results advance knowledge on how social media marketing might improve SMEs' performance in the specific context of Southwest Nigeria

Decoding Hydrogen Desorption Kinetics in Porous Silicon: An Electrical Circuit Modeling Approach.

Solid-state hydrogen storage outperforms conventional storage methods in terms of safety and on-board applications. Porous Si (PS) is the optimized Si nanostructure with ample surface area (∼400 m2 g-1) and maximum dangling sites for hydrogenation. Though solid-state hydrogen storage in Si nanostructures, especially in porous Si, is extensively studied, the thermal desorption of hydrogen is rarely reported. This work investigates and analyzes the thermal desorption of a hydrogen-terminated PS surface using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) to optimize the temperature for efficient desorption, as FTIR is sensitive to identifying the presence of Si hydride species (SiHx). The relative peak intensities in the spectra estimate the relative hydrogen retention (γ) for the analysis of the desorption kinetics. The desorption curves are divided into two zones on the time scale: the excitation zone and the recombination zone, separated by the recombination threshold point. The initially absorbed energy breaks the Si-Hx bonds in the excitation zone to reach the recombination threshold for H2 formation. The recombination zone is further divided into two subzones: the avalanche subzone (a sudden decrease in γ indicating molecular desorption) and the saturation subzone (almost constant γ with minimal desorption). The time constant from the first-order reaction kinetic fitting of the desorption curves explores the time-temperature correlation and the barrier energy estimation for the excitation and recombination zones. The analysis identifies the critical operating point for desorption as 100 °C and 4 min, with the optimized temperature of 250 °C. This article applies an analogous electrical circuit to compare the thermal hydrogen desorption and capacitor discharge circuit for analytical convenience.

6996 Optimal Growth Hormone Response Despite Low Insulin-Like Growth Factor-1: Clinical Picture of an A67T IGF-1 Variant

Abstract Disclosure: E.M. Bomberg: Research Investigator; Self; Novo Nordisk. Z. Wu: Employee; Self; Quest Diagnostics. I. Motorykin: Employee; Self; Quest Diagnostics. J. Torkelson: None. N. Schmitz: None. A. Drilling: None. M.J. McPhaul: Employee; Self; Quest Diagnostics. B.S. Miller: Advisory Board Member; Self; Abbvie, Ascendis Pharma, Biomarin, Bristol-Myers Squibb, Eton Pharmaceuticals, EMD Serono, Endo Pharmaceuticals, GenSci, Novo Nordisk, Pfizer, Inc., Provention Bio, Sanofi, Tolmar. Consulting Fee; Self; Abbvie, Ascendis Pharma, Biomarin, Bristol-Myers Squibb, Eton Pharmaceuticals, EMD Serono, Endo Pharmaceuticals, GenSci, Provention Bio, Sanofi, Tolmar. Grant Recipient; Self; Alexion Pharmaceuticals, Inc., Abbvie, Aeterna Zentaris, Amicus, Foresee Pharmaceuticals, Lumos Pharma, Lysogene, Novo Nordisk, OPKO Health, Pfizer, Inc., Prevail Therapeutics, Sangamo Therapeutics. Research Investigator; Self; Alexion Pharmaceuticals, Inc., Abbvie, Aeterna Zentaris, Amicus, Foresee Pharmaceuticals, Lumos Pharma, Lysogene, Novo Nordisk, OPKO Health, Pfizer, Inc., Prevail Therapeutics, Sangamo Therapeutics. Speaker; Self; Biomarin, Novo Nordisk, Pfizer, Inc., Tolmar. Introduction: Insulin-like growth factor-1 (IGF-1) measurements are used for growth hormone (GH) deficiency screening and helpful in monitoring GH treatment effectiveness. However, IGF-1 variants have been reported with mass spectrometry (MS)-based assays, potentially limiting interpretation of reported results. Clinical Case: A 14-year-old male presented for short stature. Evaluation was non-revealing aside from low serum IGF-1 measured via liquid chromatography (LC)-MS assay (58 ng/mL; -3.8 standard deviation score [SDS]), and IGF-Binding Protein 3 (3.7 ug/mL; -1.7 SDS). Height was 148.2 cm (1st percentile, -2.08 SDS; mid-parental height 172.7 cm [31st percentile, -0.48 SDS]), pubertal exam Tanner stage 2, and bone age 2.5 years delayed. A GH stimulation test showed a peak GH of 8.1 ug/L; brain MRI was normal. GH was started at 0.29 mg/kg/wk. One month later, IGF-1 remained low (89 ng/mL; -3.2 SDS) and GH was increased to 0.36 mg/kg/wk, and over time to 0.52 mg/kg/wk due to persistently low IGF-1 (-2.9 to -2.3 SDS), despite reports of good compliance and significant catch-up growth (height increased to 19th percentile, -0.84 SDS). He reported no significant side effects during GH treatment. At 17.5 years old, he returned to clinic reporting self-discontinuing GH 1 month prior. Height was at the 27th percentile (171.5 cm, -0.59 SDS), he was fully pubertal, IGF-1 128 ng/mL (-3.1 SDS), and bone age 1.5 years delayed. Further review of IGF-1 linked reports accompanying lab values directly entered into the electronic health record (EHR; starting 2021) described the presence of a rare heterozygous IGF-1 functional variant with unknown clinical significance based on MS data. Concentration of the variant was expected to be identical to that reported for the wild type IGF-1 protein, potentially explaining the lower than expected values. Analysis of the raw LC-MS data (variant peak at m/z 1098.09, isotopic peak index [IP6], relative retention time [rRT]=0.00 min) was consistent with either an A67T or A70T IGF-1 variant. To resolve this ambiguity, the specimen was reanalyzed with an LC-tandem MS/MS fragmentation method, which identified distinguishing peaks at m/z 503.28 (y5 ion) and 305.18 (y3 ion) characteristic of A67T, a known benign variant. Conclusions: Benign IGF-1 variants should be considered in cases of unexplained low IGF-1 levels, including when these remain low despite increasing GH doses, good adherence, and optimal growth velocity. Presence of IGF-1 variants should not affect GH stimulation results (e.g., GH levels), however, may lower reported IGF-1 levels used to determine need for diagnostic testing and followed when monitoring GH response. Careful review of IGF-1 lab reports and full abstraction of these into the EHR should be performed. Knowing a variant is benign could help providers set lower wild-type IGF-1 targets when monitoring GH response to avoid unnecessarily high GH doses. Presentation: 6/3/2024

Effects of the extrusion process on the physical properties of micro pellets and the growth performance of juvenile Nile tilapia

The present study aimed to evaluate the effect of different extrusion processes on the physical properties of micro pellets and how the alterations affect the growth performance of juvenile Nile tilapia. Four experimental diets were produced with the same formulation, but with different extrusion processes: CE: cold extrusion (18 ºC); HE: hot extrusion (100 ºC); D1: double extrusion, first a hot extrusion (100 ºC) of all the ingredients followed by cold extrusion (18 ºC); D2: double extrusion, first a hot extrusion (100 ºC) of the plant-based ingredients followed by mixing with the animal-based ingredients and milling, then cold extrusion (18 ºC). Juvenile tilapia (0.83 ± 0.01 g; 3.68 ± 0.19 cm) were distributed in 20 experimental units (60 L; n=5; 20 fish per unit) in a completely randomized design for four weeks. The micro pellets of the experimental HE diet presented a positive expansion rate (2.86 ± 0.45 %) and a lower bulk density (465.9 ± 3.45 g/L). The D1 and D2 micro pellets presented higher bulk density (671.0 ± 2.98 and 612.8 ± 4.99 g/L, respectively). All the micro pellets showed high durability (>95 %). The D2 micro pellets showed low water resistance (24.4 ± 3.51 %), resulting in a high leaching rate of nutrients (>68 %). The HE and D1 micro pellets showed a higher absorption rate in water (3.65 ± 0.29 and 3.66 ± 0.21 g water/g, respectively). The water solubility index of the micro pellets was not influenced by the different extrusion processes (P > 0.05), nor were survival and feed consumption. The fish fed with the HE diet showed greater weight gain (3.84 ± 0.44 g), and the lowest weight gain was in the fish fed with the CE diet (3.05 ± 0.39 g) (P < 0.05). Feed conversion was lower in fish fed the HE (1.06) and D1 (1.11) diets (P < 0.05). Fish fed the HE diet had the highest values for relative growth rate (9.08 ± 0.62 %/d), protein retention (30.6 ± 2.61 %) and protein efficiency (2.26 ± 0.22 %) (P < 0.05). Fish fed the CE diet had the lowest values for relative growth rate (7.82 ± 0.51 %/d), protein retention (21.4 ± 2.72 %) and protein efficiency (1.55 ± 0.23 %) (P < 0.05), though the values are in line with those in the literature. In conclusion, hot extrusion resulted in micro pellets with better physical properties and fish with higher growth performance. Double extrusion, first a hot extrusion of the plant-based ingredients followed by mixing with the animal-based ingredients and milling, then cold extrusion is not recommended due to high levels of nutrient leaching. Cold extrusion and double extrusion, first a hot extrusion of all the ingredients followed by cold extrusion processing can be considered for producing micro diets for juvenile tilapia, especially when less investment in the extrusion process is desired.

B-247 A Missing Peptide Link: A Case Study Involving Detection of an Unusual IGF-1 Protein Form Using High-Resolution Mass Spectrometry

Abstract Background Previously, we described a method for monitoring insulin-like growth factor-1 (IGF-1) variants using liquid chromatography coupled with high-resolution, accurate-mass, mass spectrometry (LC-HRAM-MS). The method split s variants in 4 Variant Groups (VG) and characterizes them by the Isotopic Peak index (IPi) and relative retention time (rRT). Uncommon variants are analyzed by tandem mass-spectrometry (MS/MS) and specimens suspected to have a novel variant are deidentified and routed for DNA sequencing. A potentially novel species was detected that did not match characteristics of any previously identified IGF-1 variant. Methods LC-HRAM-MS was used for the detection of wild type (WT) IGF-1 protein and its variants in a serum specimen. Results The patient’s IGF-1 WT concentration was 210 ng/mL and z-score was -1.5, which were within normal reference ranges values for their sex and age. LC-HRAM-MS also revealed the isotopic distribution and charge for the variant, but with new characteristics (VG2:IP2, rRT= 0.01 min). The area under curve for the variant was 36% of that of the WT, which is a stark contrast to the usual 100% found in a typical heterozygous patient. MS/MS of the suspected variant showed 2 sets of b- and y-ions, which has not been seen in our laboratory. Sequencing of the fragments revealed that one set of C- and N-terminal amino acids were from the WT (C-terminus GPETL sequence and N-terminus PLKPAKSA sequence). The intact molecular weight (MW) of the species (monoisotopic m/z 1095.5250 at charge 7+) was 18 Da heavier than that of the WT (monoisotopic m/z 1092.9482 at charge 7+), so further investigation was warranted. The other set of b- and y-ions sequenced were manually identified as GL(or I)VD and PTGYG, respectively. BLAST search did not identify relevant proteins with these N- and C-termini. However, closer inspection revealed that identified sequences were found in the WT protein, albeit not at its termini. The rest of the amino acids were found that complete termini: C-terminal b-ions sequence RAPQTGIVD corresponded to positions 37-45 of the WT sequence, while N-terminal y-ions sequence KPTGYGSSSR corresponded to positions 27-36. All evidence indicates that the species is the WT protein, but with loss of a peptide bond between 2 arginines at positions 36-37 resulting in a gain of a water molecule to “cap” the newly formed termini, which is confirmed by its observed intact m/z. Conclusions We identified an extremely rare IGF-1 species formed through loss of a peptide bond between arginines at positions 36 and 37 resulting in a “missing link” in IGF-1 amino acid sequence. Despite the cleavage, the variant was a single protein molecule with intact disulfide bonds and 2 sets of C- and N-termini. The processes involved in generating this species (e.g., hydrolysis or enzymatic cleavage) and potential consequences for the patient are unknown. Because binding to receptors and binding proteins are potentially affected, and the total level of active WT IGF-1 is reduced, we are working with patient’s physician to establish whether this unusual form of IGF-1 protein may contribute to the etiology of the patient’s condition.

A-042 Assessment of Known and Newly Discovered IGF-1 Variants by a High-throughput Clinical Reference Laboratory

Abstract Background The top-down approach to quantitate intact insulin-like growth factor 1 (IGF-1) by liquid chromatography coupled to high-resolution, accurate-mass, mass spectrometry (LC-HRAM-MS) is a highly specific and robust technique. The method also provides a unique opportunity to study point mutations represented as amino acid sequence variants in IGF-1. While physical consequences of most variants remain unknown, those in or close to the binding region of the IGF-1 protein (positions 30-62) may be pathogenic, while those at the C-terminus are likely benign. In addition, information about the presence of IGF-1 variants is critical for accurate estimation of growth hormone levels. In the current study, our goal was to assess the presence of new and known variants by targeted screening of a clinical population. Methods LC-HRAM-MS was used for the detection of the wild type (WT) IGF-1 and its variants in specimens submitted for IGF-1 testing. In total, 2,013,503 specimens were screened. A novel variant detection and identification (NVDI) approach was employed that uses variant group m/z, isotopic peak index (IPi), and relative retention time (rRT) to characterize IGF-1 variants. Deidentified specimens were analyzed with tandem mass spectrometry (MS/MS) and DNA sequencing to confirm variants. Results In the specimens that were analyzed, 0.44% had IGF-1 variants and 98% of these had amino acid substitutions in the C-terminal region. We identified 8 variants represented in the Exome Aggregation Consortium (ExAC) database (A67T, A70T, P66A, A67S, S34N, A38V, R36Q, and T4M), 2 previously reported variants (V44M and A67V), and 11 new variants (Y31H, S33P, R50Q, R56K, T41I, A62T, S34G, N26K, V44L, G7A, and R36W). The underlined variants listed were discovered in the current study and are first reported here. In total, 16 variants had amino acid substitutions in or close to the binding region of the IGF-1 protein, and these were found in 0.4% of patients with variants in the clinical population. Conclusions In the study population, almost all patients with IGF-1 variants had point mutations affecting the C-terminal amino acid sequence. Although these variants are likely benign, they could affect patient care if IGF-1 levels were underestimated by being based purely on WT concentrations. Pathogenic or possibly pathogenic variants occurred in a small but important fraction of the study population. The discovery of novel variants further validates this platform as a discovery engine for IGF-1 variants. We expect more variants to be discovered with more patients and broader criteria. Information about the presence of IGF-1 variants is critical for proper estimation of growth hormone levels. Patients with variants should have their physician informed to properly assess the patient’s condition. This collaboration between clinical laboratories and attending physicians may result in the characterization and better understanding of the role and effect of IGF-1 variants on growth disorders.

Examining the Long-term Retention of Associative Stimulus Relations in Chimpanzees (Pan troglodytes)

Examining the Long-term Retention of Associative Stimulus Relations in Chimpanzees (Pan troglodytes)

Novel Highly Hydrophilic Resins with Attached Polymer Layers for Liquid Chromatography

The aim of this work was to the obtaining novel mixed-mode stationary phases with increased hydrophilicity and applying them in ion and hydrophilic interaction liquid chromatography. The resins were obtained by the sequential covalent attachment of branched polyethylenimine and polyelectrolytes synthesized from diepoxide and a secondary amine on the surface of epoxidized polystyrene–divinylbenzene. To increase the shielding degree of the polymer substrate, an additional polymerization of glycidol was carried out in the functional layer of the sorbent at an increased pH of the reaction medium. The synthesized phases possessed increased hydrophilicity compared to most resins based on a styrene–divinylbenzene copolymer with covalently attached layers. This was evidenced in the ion chromatography mode by a decrease in the relative retention of polarizable anions, weakly hydrated oxyhalides (up to a change in the elution order of the bromate), and haloacetic acids. In the hydrophilic interaction liquid chromatography mode, an increased hydrophilicity of the phases was confirmed by an increase in the retention factors of polar analytes, as well as by the reversal of the elution order of ascorbic and nicotinic acids as compared to the phases based on polystyrene–divinylbenzene presented in the literature. The low efficiency of the obtained stationary phases in the ion chromatography mode was noted, which is associated with slow mass transfer in the bulk polymer functional layer. The negative impact of the polymer layer on efficiency in hydrophilic interaction liquid chromatography is less pronounced due to the presumably smaller thickness of the part of the functional layer involved in this mode. The proposed method for the synthesis of resins ensures an increase in the efficiency, selectivity, and separation ability of sorbents in the hydrophilic interaction liquid chromatography mode as compared to phases based on a styrene–divinylbenzene copolymer described previously in the literature. The resulting highly hydrophilic resins makes it possible to separate a mixture of 9 nitrogenous bases and nucleosides in 18 min, 6 vitamins in 24 min, and 8 sugars in 11 min. Thus, the method of substrate hydrophilization proposed in this work is promising for improving the chromatographic characteristics of phases in the hydrophilic interaction liquid chromatography mode and can be used to create sorbents with increased selectivity and efficiency.

In-situ halloysite coupled with ex-situ nano-aluminosilicate on heavy metals fate during pyrolysis of solid wastes in a rotary kiln and potential application of pyrolysis residue

During the pyrolysis of heavy metal-containing solid waste, the immobilization and stabilization of heavy metals (HM) is of great significance for its safe disposal and resource utilization of pyrolysis products. This study aims to enhance the enrichment and stability of HMs in pyrolysis residues from HM-containing solid waste in a rotary kiln by combining in-situ halloysite (Hal) with ex-situ nano-aluminosilicate (NC2.6). With 13 % Hal and 10 % NC2.6, the relative retention rate of Cd, Pb, Zn, Cu, and Cr increased by 4.82 %, 29.45 %, 20.98 %, 1.71 %, and 2.61 %, respectively, at 700 ℃. Bureau Communautaire de Référence (F4 > 85 %) and Toxicity Characteristic Leaching Procedure (7.536 mg/L at 10 % addition ratio) extraction results showed that NC2.6 adsorption products exhibit low toxicity, suitable for landfill disposal. The mobility of HMs in pyrolysis residues significantly decreased with increasing temperature and Hal addition. At 13 % Hal addition, low-risk pyrolysis residue (RI = 22.23) was obtained at 700 ℃. Dynamic adsorption experiments evaluated the feasibility of using this pyrolysis residue for methylene blue (MB) adsorption. Under the conditions of a 6 cm adsorption column height and a solution flow rate of 2.5 mL/min, the HM concentration in the effluent met relevant standards, and the adsorption capacity reached 22.733 mg/g. Furthermore, DFT simulations explored the effect of HMs in biochar on MB adsorption, revealing that the adsorption energy between Zn and N reached −281.03 kJ/mol, significantly lower than that of common oxygen-containing functional groups (COC, CO, HOCO, and OH), indicating more stable adsorption. The findings of this research offer novel insights into the immobilization of HMs during the pyrolysis of HM-containing solid waste and resource utilization of HM-containing pyrolysis residue.

Chitosan nanoparticles as drug carrier of gentamicin - density functional theory and molecular dynamics simulation studies

To the best of our knowledge, the detailed evaluation of the interaction of gentamicin with chitosan nanoparticles in the absence and presence of Sodium bis(2-ethylhexyl) sulfosuccinate (AOT) surfactant followed by the evaluation of structural, dynamical, and thermodynamic properties was carried out for the first time which helped to understand the relative drug retention and release time in the model drug delivery system. Gentamicin being an unstable drug molecule demonstrated low efficacy against brucellosis as well as considerable toxicity, thus requiring frequent dosing in different forms including a single dose and combination with other antibiotics; however, no satisfactory result was observed. Chitosan is biodegradable and biocompatible which could help overcome drug delivery issues enabling the drug to reach the target site. Our study is based on the investigation of the chitosan-drug systems without and with the surfactant for the evaluation of the structural, dynamical, and transport properties using a combined approach consisting of density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The DFT results showed that increasing the size of the chain consisting of D-glucosamine facilitated its interaction with the drug molecule thus signifying the role of polymer for the drug accommodation. Furthermore, MD simulation results exhibited the interaction of chitosan nanoparticles with the drug molecules via H-bonding and hydrophobic contacts which were enhanced after the addition of the surfactant. The dynamics and thermodynamic data corroborated the structural properties of the drug-nanoparticle interaction which confirmed the perturbation of the simulation system after the addition of the surfactant. The investigation of another two simulation systems based on the polymer constituents, D-glucosamine pointed towards the significance of the polymerization which eventually resulted in nanoparticles thus providing a platform for drug adsorption. The gentamicin-chitosan nanoparticles were further characterized via transport properties in terms of drug diffusion coefficients which served to consider its use in the context of target drug delivery to treat brucellosis.

Haemodynamic study of left nonthrombotic iliac vein lesions: a preliminary report

Nonthrombotic iliac vein lesions (NIVLs) are significant causes of chronic venous insufficiency (CVI) in the left lower limb and symptom recurrence following left lower limb varicose vein treatment. The goal of this study was to explore the haemodynamic and morphological characteristics of iliac veins in patients with NIVLs. Pressure at the caudal end of the stenotic left common iliac vein (LCIV) segment, local blood flow velocity, and time-averaged wall shear stress in the stenotic segment exhibited positive correlations with the clinical CVI classification (R = 0.92, p < 0.001; R = 0.94, p < 0.001; R = 0.87, p < 0.001), while the relative retention time showed a negative correlation (R = -0.94, p < 0.001). The pressure difference (∆P) between the two ends of the stenotic segment and the velocity difference (∆V) between the stenotic segment and the caudal end were positively correlated with the clinical classification (R = 0.92, p < 0.001; R = 0.9, p < 0.001). The cross-sectional area stenosis rate and length of the stenotic LCIV segment were positively correlated with the clinical classification (R = 0.93, p < 0.001; R = 0.63, p < 0.001). The results suggest that haemodynamic assessment of the iliac vein could effectively portray blood flow disturbances in stenotic segments of the LCIV, potentially reflecting the degree of iliac vein stenosis. Haemodynamic indicators are correlated with the severity of clinical CVI symptoms.

Citric Acid Alleviated Salt Stress by Modulating Photosynthetic Pigments, Plant Water Status, Yield and Nutritional Quality of Black gram [Vigna mungo (L.) Hepper

Background: Salt stress (SS) has seriously threatened the productivity of pulses including black gram in modern input-intensive farming systems which necessitates finding biologically viable, pro-farmer and environmentally friendly SS ameliorating strategies. Methods: An experiment was conducted to assess three levels of both SS (0, 50 and 100 mM NaCl) and citric acid (CA, 0, 50 and 100 µM) applied as a foliar spray to ameliorate the deleterious effects of SS on black gram (cv. BARI Mash-3). The response variables included plant growth traits like plant height (PH), leaf number (BLPP) and root dry weight (RDW) along with chlorophyll contents (chl a, chl b and tchl), plant water status (relative water content RWC and water retention capacity WRC), grain yield (GY), stover yield (SY), biological yield (BY)) and harvest index (HI) along with nitrogen (N) and protein (P) content of black gram. Result: The results revealed that CA (100 µM) remained unmatched by increasing PH (76.25%), NLPP (37.52%), RDW (83.67%), Chl a (17.80%), Chl b (11.59%), tChl (15.51%), RWC (9.81%) and WRC (26.64%) under highest level of induced SS. The same treatment also surpassed the rest of the doses in terms of grains number per pod (23.89%), 100 grains weight (59.74%), GY (82.86%), SY (59.66%), BY (64.94%) and HI. Moreover, CA accumulated N and P content (29.9%) in the grain under SS conditions. These results indicated that application CA alleviated the adverse effects of SS by triggering the growth, yield and nutritional quality which might be developed as a potent strategy to cope with the declining productivity of black gram in saline environment.

Expanding N-glycopeptide identifications by modeling fragmentation, elution, and glycome connectivity

Accurate glycopeptide identification in mass spectrometry-based glycoproteomics is a challenging problem at scale. Recent innovation has been made in increasing the scope and accuracy of glycopeptide identifications, with more precise uncertainty estimates for each part of the structure. We present a dynamically adapting relative retention time model for detecting and correcting ambiguous glycan assignments that are difficult to detect from fragmentation alone, a layered approach to glycopeptide fragmentation modeling that improves N-glycopeptide identification in samples without compromising identification quality, and a site-specific method to increase the depth of the glycoproteome confidently identifiable even further. We demonstrate our techniques on a set of previously published datasets, showing the performance gains at each stage of optimization. These techniques are provided in the open-source glycomics and glycoproteomics platform GlycReSoft available at https://github.com/mobiusklein/glycresoft.

Research Progress on the Risk and Prevention Measures of Peripheral Arterial Catheter Infection in ICU Patients

Peripheral arterial catheter (PAC) is an important assistant method in the treatment of critical patients. However, the related infection risk is significantly underestimated, especially the occurrence of catheter-related bloodstream infections (CRBSI), which also affects the prognosis of patients severely. After literature review, this paper summarized the risk of PAC related infections, PAC retention and maintenance infection prevention measures, and existing problems in PAC related infection research. The progress of intervention measures was collected such as strict adherence to aseptic principles, use of maximum aseptic barrier, selection of arterial puncture site, ultrasound assisted visual puncture, combination of patch and assistant fixation device, shortening of catheter retention period, use of chlorhexidine patch, and regular education and training, to provide scientific and actionable practical guidance for the prevention and control of PAC related infections in clinical practice.

Pontederia crassipes utilization for dual phytoremediation and adsorption in greywater treatment: a techno-economic and sustainable approach

While phytoremediation has been widely employed for greywater treatment, this system suffers from the transfer of considerable amounts of surfactants to the aquatic environment through partially treated effluent and/or exhausted plant disposal. Hence, this study focuses on greywater phytoremediation followed by recycling the spent plant for preparing an adsorbent material used as post-treatment. P. crassipes was used to operate a phytoremediation unit under 23 °C, 60% relative humidity, plant density (5–30 g/L), dilution (0–50%), pH (4–10), and retention time (3–15 days). The optimum condition was 12.7 g/L density, 34.0% dilution, pH 8.4, and 13 days, giving chemical oxygen demand (COD), surfactant, and NH4-N removal efficiencies of 94.62%, 90.45%, and 88.09%, respectively. The exhausted plant was then thermally treated at 550 °C and 40 min to obtain biochar used as adsorbent to treat the phytoremediation effluent. The optimum adsorption process was biochar dosage of 1.51 g/L, pH of 2.1, and 137 min, providing a surfactant removal efficiency of 92.56%. The final discharge of this phytoremediation/adsorption combined process contained 8.30 mg/L COD, 0.23 mg/L surfactant, and 0.94 mg/L NH4 +-N. Interestingly, this approach could be economically feasible with a payback period of 6.5 years, 14 USD net present value, and 8.6% internal rate of return.

Thermal-mechanical evolution behaviors of metal matrix diamond composite by powder bed fusion-laser beam

The thermal damage of diamond and the residual stress have always been the critical issues to be resolved in the development of metal matrix diamond composites. In the presented study, FeCoCrNi high entropy alloys (HEAs)-diamond composites were fabricated by powder bed fusion-laser beam of metals (PBF-LB/M), using un-coated diamond and Ti–Ni coated diamond, respectively. Based on the numerical and experimental analysis, the effect of thermal-mechanical behavior on the microstructures and mechanical properties of the composites was systematically investigated. By establishing the temperature field of the PBF-LB molten pool, the defects, diamond graphitization and in-situ TiC formation were studied. The start-temperature for diamond graphitization in coated samples was 365 °C higher than that of un-coated samples, due to the diffusion barrier effect of TiC. Subsequently, by thermo-mechanical coupling, the property and value of the residual stress exhibited sudden change at the diamond/matrix interface. The TiC intermediate layer significantly relieved the stress concentration at interface, and effectively avoided cleavage fracture of the diamond and the initiation of interfacial cracks. At the moderate molten-pool temperature, the coated diamond composites exhibited optimal performance, as bending strength of 913 MPa, friction coefficient of 0.25 and worn mass loss of 0.67 mg. Finally, the quantitative relationship between PBF-LB molten-pool temperature and the relative density, graphitization degree, residual stress, retention(bending strength) and wear performance was established, to demonstrate the thermal-mechanical evolution of the HEAs-diamond composites by PBF-LB.