Saturating Amounts Research Articles

Exploration of BSA imprinting mechanism by fluorescence anchoring and host–guest interactions

AbstractFor protein imprinting, template molecule anchoring and imprinting site recognition are very important processes. Herein, we have proposed for the first time to use photo‐switchable host–guest interactions between α‐cyclodextrin (α‐CD)‐modified bovine serum albumin (BSA) and azobenzene coated organic covalent framework (COF) to immobilize and elute proteins. A novel surface labeled polymer microspheres (COF‐MIPs) were constructed, which could reduce the mass transfer resistance and accelerate the adsorption process, resulting in the adsorption equilibrium reaching 60 min and the saturated adsorption amount of 563.86 mg/g. Additionally, using guest molecules (azobenzene) to label the imprinted sites allows the correlation of the relationship between the fluorescence intensity and the protein adsorption process. The fluorescence analyses show that the material exhibits excellent adsorption specificity, with imprinting factors greater than 4. This work extended the application of the host–guest interaction between cyclodextrin and azobenzene and provides a new approach for developing protein‐imprinting materials.

Investigation of efficient adsorption-electrochemical degradation performance of ZIF-8/MWCNTs nanocomposites toward 2,4-dichlorophenol

The highly toxic and recalcitrant organic pollutant, 2,4-dichlorophenol (2,4-DCP), is commonly found in wastewater. Therefore, it is critical to investigate novel techniques for the efficient removal of 2,4-DCP from wastewater. The present study employed a one-step synthesis method to fabricate ZIF-8/multi-walled carbon nanotubes (ZIF-8/MWCNTs) nanocomposites with well-defined mesoporous structures, which were subsequently coated onto carbon cloth (CC) to form the anode ZIF-8/MWCNTs/CC. Subsequently, the adsorption performance of ZIF-8/MWCNTs toward 2,4-DCP and the adsorption-electrochemical degradation performance of ZIF-8/MWCNTs/CC toward 2,4-DCP were investigated. ZIF-8/MWCNTs exhibit exceptional adsorption capacity and rate toward the 2,4-DCP. At 303 K, it achieved a saturated adsorption amount as high as 1056.78 mg·g-1 within only 30 min of reaching equilibrium. Moreover, when coated on CC substrates, the internal pore structure of ZIF-8/MWCNTs is effectively exploited during the adsorption. In addition, the incorporation of MWCNTs enhances the conductivity of the ZIF-8/MWCNTs/CC electrodes, leading to reduced resistance and improved electron transfer rate. Notably, ZIF-8/MWCNTs/CC enabled complete removal of a 25 mg·L-1 solution of 2,4-DCP within only 90 min and a 50 mg·L-1 solution within 120 min. Furthermore, the degradation mechanism of 2,4-DCP was analyzed by means of DFT modeling theoretical calculations and intermediate product determination analysis, while evaluating the toxicity of the generated material was evaluated. This study provides improved solutions and strategies for the treatment of chlorophenolic compound pollution in wastewater.

Flexible MOF@fabrics composites: The in-situ growth of metal-organic frameworks on cotton and selectively adsorption of gold(III) from aqueous solution

Metal-organic frameworks (MOFs) show great potential applications in dealing with heavy metal pollution due to their unique large specific surface area, tunable pore size, and diverse active groups. However, the powder form of MOFs has suffered from the disadvantages of difficult recycling and secondary contamination after adsorption of heavy metals, which seriously limits their practical application. Therefore, in this work, we prepared a series of bifunctional zirconium-based MOFs cotton fabric composites (MCFC) via in situ growth of MOFs on carboxylated cotton fabric, exhibiting large specific surface area, adjustable pore size, and effective adsorption ability. The prepared CF-UiO-66-(OH)2-FA shows an excellent adsorption efficiency of Au(III) more than 99.990 %, and the saturated adsorption amount is up to 190.98 mg·g−1 at 25 °C. Meanwhile, the kinetic experiment analysis demonstrated that the Au(III) adsorption behavior of MCFC follows pseudo-second-order (PSO) kinetic model. More importantly, it also exhibits great selectivity in adsorbing Au(III) from the mixture of multiple metal ions coexisted solution. The results of adsorption thermodynamics and adsorption isotherms indicate that adsorption is monolayer and a spontaneous, exothermic process. And the ideal adsorption and separation process could be finished by quickly filtrating with a single or multi-layer MCFC. Excellent adsorption performance even after four cycles of adsorption. Therefore, the fabricated MCFC shows great processability, flexibility, collectability and reusability in adsorbing and recycling precious metal ion from wastewater.

Competitive water adsorption for low-energy desalination: Insights from statistical physics theory

In this research, the statistical physics theory has been deployed to unlock the mysteries of water molecule binding on Zeolite and Silica Gel at the microscopic level. The adopted computational procedure, based on the grand canonical partition function, provided physical insights of the docking mechanism by scrutinizing the stereographic and energetic variables. The number of receiving sites, their densities, the saturation amount and the energetic factors were assessed due to the strong consistency between the numerical and experimental results. Docking inspections revealed that H2O primarily adopted a non-parallel orientation upon interaction with the adsorbent receptor sites. The estimated attachment energies ranged from 18.25 kJ/mol to 24.55 kJ/mol indicating a physisorption process where weak forces (van der Waals) mainly govern the surface occupancy. Desalination effectiveness has been examined and according to calculations the coefficient of performance (COP) and the quantitative efficiency metric (QEM) is 2.7 times and 1.2 times respectively greater in case of Zeolite than Silica Gel. By analyzing pore size distribution (PSD) and adhesion energy distribution (AED), this study elucidates the relationship between pore size and target molecule capture, and predicts binding strength and potential for molecule capture/release under various conditions.

Adsorption and detection of praseodymium ion by ion-imprinted polymer with ultra-low sensitivity.

A novel kind of carbon dot (CD) was prepared by one-step hydrothermal microwave assisted method using L-tryptophan and L-tartaric acid as raw materials. Monodisperse poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) microspheres were utilized as the matrix, with praseodymium (Pr) ion (Pr3+) as the template, methacrylic acid as the functional monomer, and 5-amino-8-hydroxyquinoline (5-AHQ) acts as the ligand. A composite microsphere of ion-imprinted polymer (IIP) and CD (noted CD@IIP) was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). For comparison, IIP without CD (Pr-IIP) and non-imprinted polymer (NIP) were also prepared. Through static adsorption experiments, it was determined that the saturated adsorption amount of CD@IIP is 47.19mgg-1, that of Pr-IIP is 54.49mgg-1, while that of NIP is only 24.32mgg-1. Dynamic adsorption experiments showed that the equilibrium of three kinds of materials wasreached within 30min. Particularly, CD@IIP could emit two fluorescence peaks at 325nm and 421nm under ultraviolet irradiation, and exhibited excellent selectivity and fluorescence quenching effect on Pr3+. The fluorescence response of Pr3+ in the range 0-400μmol L-1 was determined by ratiometric fluorescence method, offering a two-stage model and robust linear regression coefficient. These results demonstrated that CD@IIP exhibited selective adsorption ability for Pr3+, and a sensitive, rapid and simple method for detection of Pr3+ was successfully developed.

Investigation into diffusion behaviours of moisture in asphalt film using Fourier transform infrared spectroscopy

ABSTRACT To reveal the moisture damage mechanism of asphalt pavement and clarify the process of moisture damage to asphalt films, the diffusion behaviours of moisture in asphalt films were analysed. The findings indicate that during the first stage of the water bath process, the moisture diffusion coefficient in asphalt films is considerable and the diffusion rate is rapid. As the moisture diffusion rate increases, the free moisture content in asphalt films tends to saturate. Subsequently, partial free moisture transitions into bound moisture results in a decline in the diffusion coefficient of asphalt films and a reduction in its moisture absorption rate. As the temperature rises, the moisture diffusion coefficient in asphalt film and the maximum saturation amount of moisture that can be absorbed by asphalt films increase. The moisture diffusion behaviour is not readily discernible at a low temperature. The diffusion coefficients of moisture in unmodified asphalt films in the two stages are higher than those in modified asphalt films. The first stage of moisture diffusion in unmodified asphalt films occurs at a faster rate than in modified asphalt films. It is further verified that unmodified asphalt is more subjected to moisture damage.

Great truths are always simple: A millimeter-sized macroscopic lanthanum-calcium dual crosslinked carboxymethyl chitosan aerogel bead as a promising adsorbent for scavenging oxytetracycline from wastewater

Given their increasing environmental and health harms, it is crucial to develop green and sustainable techniques for scavenging antibiotics represented by oxytetracycline (OTC) from wastewater. In the present work, a structurally simple lanthanum-calcium dual crosslinked carboxymethyl chitosan (CMCS-La3+-Ca2+) aerogel was innovatively synthesized for adsorptive removal of OTC. It was found that CMCS and La3+ sites collaboratively participated in OTC elimination, and OTC removal peaked over the wide pH range of 4–7. The process of OTC sorption was better described by the pseudo-second-order kinetic model and Redlich-Peterson model, and the saturated uptake amount toward OTC was up to 580.91 mg/g at 303 K, which was comparable to the bulk of previous records. The as-fabricated composite also exerted exceptional capture capacity toward OTC in consecutive adsorption-desorption runs and high-salinity wastewater. Amazingly, its packed column continuously ran for over 60 h with a dynamic uptake amount of 215.21 mg/g until the adsorption was saturated, illustrating its great potential in scale-up applications. Mechanism studies demonstrated that multifarious spatially-isolated reactive sites of CMCS-La3+-Ca2+ cooperatively involved in OTC capture via multi-mechanisms, such as n-π EDA interaction, H-bonding, La3+-complexation, and cation-π bonding. All the above superiorities endow it as a promising adsorbent for OTC-containing wastewater decontamination.

Transport Instabilities of Hazardous Contaminants in a Microscale Soil Sample Under Thermal Flow of Supercritical CO2

This work reveals the transient dynamics of supercritical carbon dioxide (sCO2) under a joint heat and mass interactions with resident polycyclic aromatic hydrocarbons (PAHs) in sedimentary microporous media. A variant of Multiphase Color Fluid Lattice Boltzmann model is developed to simulate spatiotemporal evolution of sCO2 front with degradation of a 5 μm mass-film of resident PAHs. The injection conditions of sCO2 range from 305 K to 315 K, and from 8 MPa to 10 MPa, with a mass flow rate of 0.05–0.15 kg/min. It has been found in this study that the growth of clusters reveals a critical operating time to promote the solvation power of sCO2. However, the cluster of such contaminants is affected by a secondary degradation inside the pore throats of the microporous. The heat and mass coefficients are remarkably relied on the nature of the contaminants and their clustering/clogging processes inside the pores. Hence, the saturation amount of CO2 will jump from a prompt movement to a quick equilibrium state while facing the balanced phase of clustering/degradation of resident contaminants inside the microporous media.

Study on adsorption of scandium by iminodiacetic acid resin TP207

Abstract Scandium (Sc) is a rare transition metal applied in unique electronic/alloy materials such as magnesium scandium alloy, aluminum scandium alloy, laser glass, superconductors, and electronic components. However, scandium is extremely hard to obtain. In this paper, the iminodiacetic acid resin TP207 was first applied for the recovery of scandium from a hydrochloric acid solution. The adsorption of Sc3+ by TP207 resin was analyzed by SEM-EDS, FT-IR, and XPS. It was found that the best adsorption time was 2 hours with the equilibrium adsorption rate reaching 99%. The saturated adsorption amount of resin was 0.05g/ml. This process involves the ion exchange of scandium ions with sodium ions on the resin and the chemisorption of scandium with the -COO- group. Furthermore, the TP207 resin exhibited a quasi-second-order kinetic mechanism towards Sc3+, which was the rate of adsorption is proportional to the concentration of the reactants. In addition, the adsorption of resin for Sc3+ is an endothermic reaction by calculating the thermodynamic parameters, and there is a 3.6% difference in adsorption efficiency between the two cycle experiments. In a word, the TP207 resin is a very promising adsorbent for Sc beneficiation from the HCl system.

Adsorption Capacity of Activated Carbon-Encapsulated Hollow-Type Spherical Bacterial Cellulose Gels for Uremic Toxins in a Simulated Human Gastrointestinal Environment.

To reduce the risk of the adsorption of granular activated carbon in the gastrointestinal tract, we successfully produced a hollow-type spherical bacterial cellulose (HSBC) gel containing activated carbon with a particle size of 6 μm. In this study, the aim of which was to develop an effective formulation, we evaluated the stability of activated-carbon-encapsulating HSBC gels under various pH conditions. Activated-carbon-encapsulating HSBC gels (ACEGs) retained the activated carbon without leaking when subjected to agitation in acidic or basic environments. The saturated adsorption amount, calculated using the Langmuir adsorption isotherm, was affected by the target adsorbate and pH conditions. These results indicate that ACEGs can adsorb uremic toxins and their precursors similarly to conventional uremic toxin adsorbents while preventing direct contact between the encapsulated activated carbon and the gastrointestinal tract. Compared to powdered activated carbon, the ACEG is less likely to be adsorbed in the gastrointestinal tract. Therefore, the proposed ACEG is a promising new formulation that will contribute to the treatment of renal failure and improve patients' compliance with medication.

The Effect of Plasma Exchange on Recovery of Patients with Coronavirus Disease 2019 (COVID-19) Admitted to the Intensive Care Unit

Introduction: To evaluate the efficacy and safety of Plasma Exchange (PE) in Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) positive pneumonia patients. Method: This study was a case series conducted at a referral hospital. Twenty SARS-CoV-2-positive patients had an oxygen saturation of 80-90%, and the respiratory rate above 30 per minute. These symptoms started 1 week after the onset of the disease. All patients had less than 90% oxygen saturation and needed respiratory support (oxygen therapy) treated with plasma exchange on 3-5 consecutive days during hospitalization. We followed the amount of oxygen saturation, which was in the form of increasing the patient's oxygen saturation above 90% without oxygen supply and above 92% without oxygen, improving shortness of breath and improving patients' clinical symptoms. Results: Our study included a total of 20 COVID-19 patients with an overall mean age of 48.9 ± 12.1 years (range: 39–58 years); 60% (n=12) were males, 34.5% of whom benefited from TPE sessions. On the third day after the treatment, shortness of breath improved in these patients. Oxygen saturation of any twenty patients increased before the procedure of plasma exchange. Clinical symptoms of all patients were decreasing shortness of breath and improving patients' clinical symptoms after the procedure. Conclusion: According to our observations, plasma exchange could not show a significant therapeutic effect in COVID-19 patients with severe lung involvement.

Highly Efficient Separation of Ethanol Amines and Cyanides via Ionic Magnetic Mesoporous Nanomaterials.

Simple and efficient sample pretreatment methods are important for analysis and detection of chemical warfare agents (CWAs) in environmental and biological samples. Despite many commercial materials or reagents that have been already applied in sample preparation, such as SPE columns, few materials with specificity have been utilized for purification or enrichment. In this study, ionic magnetic mesoporous nanomaterials such as poly(4-VB)@M-MSNs (magnetic mesoporous silicon nanoparticles modified by 4-vinyl benzene sulfonic acid) and Co2+@M-MSNs (magnetic mesoporous silicon nanoparticles modified by cobalt ions) with high absorptivity for ethanol amines (EAs, nitrogen mustard degradation products) and cyanide were successfully synthesized. The special nanomaterials were obtained by modification of magnetic mesoporous particles prepared based on co-precipitation using -SO3H and Co2+. The materials were fully characterized in terms of their composition and structure. The results indicated that poly(4-VB)@M-MSNs or Co2+@M-MSNs had an unambiguous core-shell structure with a BET of 341.7 m2·g-1 and a saturation magnetization intensity of 60.66 emu·g-1 which indicated the good thermal stability. Poly(4-VB)@M-MSNs showed selective adsorption for EAs while the Co2+@M-MSNs were for cyanide, respectively. The adsorption capacity quickly reached the adsorption equilibrium within the 90 s. The saturated adsorption amounts were MDEA = 35.83 mg·g-1, EDEA = 35.00 mg·g-1, TEA = 17.90 mg·g-1 and CN-= 31.48 mg·g-1, respectively. Meanwhile, the adsorption capacities could be maintained at 50-70% after three adsorption-desorption cycles. The adsorption isotherms were confirmed as the Langmuir equation and the Freundlich equation, respectively, and the adsorption mechanism was determined by DFT calculation. The adsorbents were applied for enrichment of targets in actual samples, which showed great potential for the verification of chemical weapons and the destruction of toxic chemicals.

Preparation and Characterization of Lignin‐Based Activated Carbon by Rubidium Chloride Chemical Method

AbstractIn order to prepare carbon adsorbent materials, lignin was used as raw material and rubidium chloride as activator, activated carbon materials were prepared by chemical activation method, and its structure was characterized and its adsorption performance on methylene blue solution was investigated; the adsorption of crystalline violet dye was carried out at different temperatures, and the adsorption thermodynamics was studied. The results showed that: the specific surface area of the activated carbon was 433.32 m2/g, the pore volume was 0.2191 cm3/g, and the average pore size was 2.0222 nm; the adsorption value of methylene blue could reach 172.0 mg/g, and it could quickly and efficiently adsorb methylene blue solution; the adsorption effect on crystal violet solution was good, and the saturated adsorption amount at 40 °C was up to 279 mg/g, and the removal rate reached 93 %, belonging to the spontaneous adsorption thermodynamic reaction. The experiment proved that rubidium chloride can be used as an activator to activate lignin raw materials to prepare activated carbon samples, and can effectively adsorb dyes.

Mitochondrial Peroxiredoxin 6 Declines with Aging in Parallel with Increases in Hydrogen Peroxide Generation

Oxidative stress in cells and tissues arise from an imbalance between the generation of free radicals and the ability to detoxify these reactive oxygen species (ROS). Peroxiredoxins (PRDXs) are a family of widely distributed enzymes that act as master antioxidant regulators by scavenging peroxides and peroxynitrites. The accumulation of oxidative damage from chronic exposure to oxidative stress such as on DNA, mitochondrial proteins, and lipid macromolecules, is postulated to result in age-associated pathologies and physiological dysfunctions. Peroxiredoxin-6 (PRDX6) contributes to the maintenance of redox balance in a variety of tissues from lung to skeletal muscle. Here, we hypothesized that PRDX6 localizes to the mitochondria and plays a significant role in maintaining mitochondrial function through targeting mitochondrially generated ROS, and that gradual loss of mitochondrial PRDX6 contributes to increased oxidative stress and accumulation of oxidative damage during aging. In this study, respiratory rates and complex activities in isolated skeletal muscle mitochondria obtained from young (3-6 months) and old (20-24 months) C57/BL6J mice were compared. Amplex UltraRed fluorescence was used to determine production rates of mitochondrial hydrogen peroxide (H2O2). Western blot analysis was used to compare protein abundance and ELISA was used to measure lipid peroxidation in skeletal muscle mitochondrial fractions. Our findings revealed that isolated mitochondria from skeletal muscle in old mice generated higher rates of H2O2 from complex I (CI) during state 3 and state 4 (State 3; State 4) derived respiration (3.93 ± 0.41; 3.56 ± 0.38 pmol H2O2..s−1.mg−1) compared to young mouse mitochondria (1.57 ± 0.48; 1.89 ± 0.59 pmol H2O2.s−1.mg−1, p ≤ 0.05). This was also found when saturating amounts of ADP were used to stimulate maximal rates of oxygen consumption (old: 3.65 ± 0.77; young 1.40 ± 0.21 pmol H2O2−1.mg−1, p ≤ 0.05). Furthermore, CI activity was found to be lower in isolated mitochondria from old mice (0.65 ± 0.006 U.ug−1) compared to young mice (2.11 ± 0.64 U.ug−1, p ≤ 0.05). Similarly, mitochondrial PRDX6 abundance was lower while levels of lipid peroxidation product malondialdehyde were higher in skeletal muscle from old animals (old: 2712 ± 1320 pg.mL−1; young: 489 ± 225 pg.mL−1). These results show higher mitochondrial ROS generation rates and oxidative damage in old animals. These data also suggest that loss of PRDX6 in aging leads to mitochondrial dysfunction mediated by diminished CI activity and loss of membrane integrity. We are currently conducting mechanistic studies in cellular models with disrupted PRDX6 expression to confirm the effect of this protein in maintaining mitochondrial function. This study offers novel observations on the significance of mitochondrially localized PRDX6 in antioxidant defense as well as the sources and roles of ROS generation in contributing to an aging phenotype. National Institute of General Medical Sciences (NIGMS, Award Number R35GM146951). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Analysis of polydisperse polymer adsorption on porous cellulose fibers.

The adsorption of cationic water-soluble polymers onto negatively charged porous wood pulp fibers is an essential aspect of papermaking. Adsorption data can be displayed as a direct plot of the amount adsorbed, Γ, versus the amount of polymer added or as an isotherm plot showing the amount adsorbed versus the residual unadsorbed polymer. In either data presentation, the analysis is more transparent if the units of each axis are the same (e.g., mg/g or meq/g), giving dimensionless slopes. Values for Γmax, ΓI, f I , and Γme can be extracted from many isotherms where: Γmax is the maximum capacity of the fibers to adsorb polymer; ΓI is the y-axis isotherm intercept and gives the maximum dose that can be fully adsorbed; f I is the slope of the direct plot at ΓI, and f I is the mass fraction of the added polymer that can access interior (pore) surfaces; and, Γme is the saturated amount of polymer adsorbed on exterior surfaces. Additionally, the molecular weight distribution of theadsorbing polymer in conjunction with the adsorption isotherm can be used to estimate the molecular weight distributions of adsorbed polymer on interior and exterior fiber surfaces as functions of the polymer dose.

An enhancement in the petrophysical evaluation in a vuggy carbonate gas reservoir by integrating the core data and empirical methods, Zagros basin, south of Iran

The presence of vuggy pore types poses challenges in accurately assessing effective porosity. This study focuses on the significant scientific issue of improving petrophysical evaluation in vuggy carbonate gas reservoirs. The Kangan Formation is one of the main gas reservoir formations in the southern Zagros region, Iran. The main objective of the current research is to distinguish and exclude the influence of vuggy pore types from effective porosity in the reservoir pay zones of the Kangan reservoir.In the current research, a combination of full suite logs, image logs, core analysis, and thin section studies was employed. The image logs illustrate that vuggy porosity is abundant in the Kangan Formation and these results are confirmed by the available core thin sections, specifically in Zone Kangan_B; Additionally, the cross plots of compressional velocity versus bulk density and total porosity, as a part of rock physics study, indicate the characteristics of the vuggy reservoir. Two methods are utilized to quantify vuggy porosity. The first method, the Velocity Deviation Log (VDL) approach, identifies various available pore types, especially vugs. The second method is a newly proposed approach that can exclude vuggy porosity from the computed effective porosity. In this novel approach, a variable porosity exponent (m) is derived by adopting the Lucia equation to exclude vuggy porosity from the effective porosity computations. Thus, petrophysical evaluation can be implemented based on the constant and variable “m”. Comparing both petrophysical results, it is evident that the amounts of effective porosity and water saturation are modified in the vuggy-bearing intervals. Applying the proposed approach will improve the accuracy of petrophysical properties and lead to the proper calculation of the hydrocarbon volume in the carbonate reservoir rocks containing isolated vugs, particularly in gas-bearing reservoirs where conventional logs are affected by gas contents.

Oxidation state of cobalt oxide in thermal-cyclic atomic layer etching of cobalt by plasma oxidation and organometallization

Thermal-cyclic atomic layer etching of Co blanket film and a fine pattern by plasma oxidation and organometallization were investigated. To obtain a smoothly etched surface and self-limiting etching, a two-step temperature-etching process was used. Co was first oxidized using O2 plasma at a low temperature of 25 °C. Then, the Co oxide formed in the first step was organometallized with acetylacetone (acacH) and sublimed at a high temperature of 210 °C, which is appropriate for organometallization and sublimation. The etched amount per cycle was 0.6 nm. This value is the same as the saturated oxidation amount. The root-mean-square roughness after 20-cycle etching was 0.53 nm, and an atomically smooth etched surface was obtained. From the x-ray photoelectron spectroscopy (XPS) analysis, the oxidation state of Co oxide with a 530-eV O1s peak was dominant for organometallization with acacH. As the temperature increased, the O1s XPS peak of the Co oxide shifted lower to 529 eV and formed a columnar-shaped oxide. However, with acacH, oxide was organometallized when the O1s peak was at 530 eV.

Preparation of Adsorbent from Mechanochemical Reaction-Based Waste Seashell with Sodium Oxalate and Its Application in Pb Ion Adsorption

Waste seashell (scallop shell)-based adsorbent was prepared via mechanochemical reaction with sodium oxalate using ball milling. The oxalate-modified seashell-based adsorbents (OS) were prepared by varying the molar ratio of calcium and oxalate to 0.5, 1, and 2. Sodium oxalate was used as the aqueous solution in ball milling. Lead ion adsorption was conducted with the prepared adsorbent. The adsorption behavior of lead ions was investigated in terms of adsorption kinetics and adsorption equilibrium. The time course of the amount of Pb adsorbed agreed well with Langmuir rate equation. The adsorption equilibrium relationship of OS adsorbent and Pb agreed well with the Langmuir adsorption isotherm. Increasing with the molar ratio, the saturated amount of Pb adsorbed increased slightly from 5.45 × 10–3 to 6.23 × 10–3 mol/g. Under the present experimental conditions, the maximum equilibrium adsorption was 5.93 × 10–3 mol/g, which is greater than that reported in the literature.

Obstrüktif Uyku Apnede (OUA) Ortalama Trombosit Hacmi (OTH) ve OUA'da Sürekli Pozitif Hava Yolu Basıncı (CPAP) Tedavisinin OTH Üzerine Etkisi

Aims: In this study, our objective was to evaluate mean platelet volume (MPV), an indirect marker of platelet activation, in patients with obstructive sleep apnea (OSA), and assess the effect of OSA treatment with continuous positive airway pressure (CPAP) on MPV
 Methods: In this study, records of consecutive patients who underwent polysomnographic evaluation for OSA symptoms in the Sleep Disorders Laboratory during a one-year period were reviewed retrospectively. Patients who had both complete blood count and MPV measurements were included in the study.
 Results: A total of 158 patients, including 51 females (32.3%) and 107 males (67.7%), were included in the study. The mean age of the patients was 51±13 (min-18, max-82) years. OSA was detected in 74.1% (117/158) of the patients. It was determined that as the severity of OSA increased, hemoglobin and hematocrit values increased significantly. There was no significant difference in platelet count according to the presence and severity of OSA. The MPV was significantly lower in severe OSA cases compared to those without OSA and mild OSA cases. A negative correlation was observed between MPV and the apnea-hypopnea index, desaturation index, and the amount of oxygen saturation below 90% during sleep. There was no significant difference in median erythrocyte and thrombocyte counts, hematocrit percentage and hemoglobin values before and after treatment in OSA patients who used CPAP therapy. However, a significant decrease in MPV was observed after OSA treatment compared to pre-treatment. (p=0.021).
 Conclusions: The results of the study do not support an increase in MPV and hence platelet activation in severe OSA patients compared with those without OSA. However, the results suggest that one month of CPAP treatment reduces MPV and thus platelet activation in severe OSA patients. Further controlled, prospective studies including treatment outcomes are needed on this subject.

Increased low-density lipoprotein cholesterol on a low-carbohydrate diet in adults with normal but not high body weight: A meta-analysis

BackgroundLow-density lipoprotein (LDL) cholesterol change with consumption of a low-carbohydrate diet (LCD) is highly variable. Identifying the source of this heterogeneity could guide clinical decision-making. ObjectivesTo evaluate LDL cholesterol change in randomized controlled trials involving LCDs, with a focus on body mass index (BMI) in kg/m2. MethodsThree electronic indexes (Pubmed, EBSCO, and Scielo) were searched for studies between 1 January, 2003 and 20 December, 2022. Two independent reviewers identified randomized controlled trials involving adults consuming <130 g/d carbohydrate and reporting BMI and LDL cholesterol change or equivalent data. Two investigators extracted relevant data, which were validated by other investigators. Data were analyzed using a random-effects model and contrasted with results of pooled individual participant data. ResultsForty-one trials with 1379 participants and a mean intervention duration of 19.4 wk were included. In a meta-regression accounting for 51.4% of the observed variability on LCDs, mean baseline BMI had a strong inverse association with LDL cholesterol change [β = –2.5 mg/dL/BMI unit, 95% confidence interval (CI): –3.7, –1.4], whereas saturated fat amount was not significantly associated with LDL cholesterol change. For trials with mean baseline BMI <25, LDL cholesterol increased by 41 mg/dL (95% CI: 19.6, 63.3) on the LCD. By contrast, for trials with a mean of BMI 25–<35, LDL cholesterol did not change, and for trials with a mean BMI ≥35, LDL cholesterol decreased by 7 mg/dL (95% CI: –12.1, –1.3). Using individual participant data, the relationship between BMI and LDL cholesterol change was not observed on higher-carbohydrate diets. ConclusionsA substantial increase in LDL cholesterol is likely for individuals with low but not high BMI with consumption of an LCD, findings that may help guide individualized nutritional management of cardiovascular disease risk. As carbohydrate restriction tends to improve other lipid and nonlipid risk factors, the clinical significance of isolated LDL cholesterol elevation in this context warrants investigation.This trial was registered at PROSPERO as CRD42022299278.