Purity Level Research Articles

Improved process design for monoclonal antibody charge variants separation with multicolumn counter-current solvent gradient purification

The multicolumn counter-current solvent gradient purification (MCSGP) method has proven effective in addressing the issue of elution profile overlap for difficult-to-separate proteins, leading to improved purity and recovery. However, during the MCSGP process, the flow rate and proportion of loaded proteins undergo changes, causing a significant discrepancy between the elution profiles of batch process design and the actual MCSGP process. This mismatch negatively impacts the purity and recovery of the target protein. To address this challenge, an improved process design (reDesign) was proposed with the first-run MCSGP to mimic the actual continuous process and obtain elution profiles that closely resemble the real ones. The reDesign was demonstrated with both a model protein mixture and a sample of monoclonal antibody (mAb) with charge variants. For model protein mixture, the reDesign-based MCSGP process (reMCSGP) showed a remarkable improvement in recovery, increasing from 83.6% to 97.8% while maintaining a purity of more than 95%. For mAb sample, the recovery of reMCSGP improved significantly to 93.9%, surpassing the performance of normal MCSGP processes at a given purity level of more than 84%. In general, the new process design strategy developed in this work could generate a more representative elution profile that closely mirrors actual conditions in continuous processes, which enhances the separation performance of MCSGP.

Application of deep neural network and gamma radiation to monitor the transport of petroleum by-products through polyducts

To continuously monitor information about the transport of fluids by sequential batches in polyduct, found in the petrochemical industry, it is necessary to manage the mixing zone – transmix – that occurs when two fluids are being transported. This scenario demonstrates the need to estimate the interface region and the purity of the fluids in this region to improve the management of the pipeline and, thus, reduce associated costs. This study presents a measurement system based on the dual-modality gamma densitometry technique in combination with a deep neural network with seven hidden layers to predict the purity level of four different fluids (Gasoline, Glycerol, Kerosene and Oil Fuel) in the transmix. The detection geometry is composed of a137Cs radioactive source (emitting gamma rays of 661.657 keV) and two NaI(Tl) scintillator detectors to record the transmitted and scattered photons. The study was performed by computer simulations using the MCNP6 code, and the information recorded in the detectors was used as input data for training and evaluating the deep neural network. The proposed intelligent measurement system is able to predict the purity level of fluids with errors with mean squared error values below 1.4 and mean absolute percentage error values below 5.73% for all analyzed data.

Synthesis of nano-silica as a promising route of recycling phosphate waste rocks and its incorporation in mortars

This article is devoted to the synthesis of nano-silica from phosphate waste rocks as a promising route of recycling these silica-rich phosphate by-products. Furthermore, their reactivity potential will be investigated while incorporating them as nano-additive and as a partial replacement to cement in the conventionally used recipes of mortars. It has been shown that the synthesized nano-silica has a higher level of purity and a large specific surface area, which is about 8 times higher than the initial raw material. Various formulations of mortars were tested after adding different percentages of nano-silica to the ordinarily used recipe, at a constant water-to-cement ratio, and their microstructure, mineralogical composition, and mechanical properties were investigated. It was shown that compressive strength and flexural strength increased, and the fluidity of the mortars decreased when the ratio of nano-silica increased from 1% to 5%.

Experimental assessment of nuclear cross sections for the production of Tb radioisotopes with a medical cyclotron

155Tb is one of the most interesting radionuclides for theranostic applications. It is suitable for SPECT imaging and it can be used as a true diagnostic partner of the therapeutic 149Tb and 161Tb. Its production by proton irradiation using enriched 155Gd and 156Gd oxide targets is currently being investigated and represents a promising solution. To achieve the level of radionuclidic purity required in the clinical setting, the co-production of Tb impurities has to be minimized. For this purpose, an accurate knowledge of the cross sections of the nuclear reactions involved is of paramount importance. In this paper, we report on the assessment of cross sections of the reactions 154Gd(p,xn)153,154,154m1,154m2Tb, 155Gd(p,xn)154,154m1,154m2,155Tb, 156Gd(p,xn)155,156Tb and 157Gd(p,2n)156Tb derived with a specific data analysis procedure developed by our group. This method allows to disentangle the nuclear contributions from the production cross section by inverting linear systems of equations and it requires the measurement of the cross sections from as many materials as the reactions involved in the production of the radionuclide under study. For this purpose, the experimental data previously measured by our group at the Bern medical cyclotron by irradiating natural Gd2O3, enriched 155Gd2O3 and enriched 156Gd2O3 targets were used. For some of these nuclear reactions, cross sections were assessed for the first time. On the basis of our findings, production yield and purity can be calculated for any kind of isotopic composition of the enriched material.

Cosmological Constraints from the BOSS DR12 Void Size Function

We present the first cosmological constraints derived from the analysis of the void size function. This work relies on the final Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 (DR12) data set, a large spectroscopic galaxy catalog, ideal for the identification of cosmic voids. We extract a sample of voids from the distribution of galaxies, and we apply a cleaning procedure aimed at reaching high levels of purity and completeness. We model the void size function by means of an extension of the popular volume-conserving model, based on two additional nuisance parameters. Relying on mock catalogs specifically designed to reproduce the BOSS DR12 galaxy sample, we calibrate the extended size function model parameters and validate the methodology. We then apply a Bayesian analysis to constrain the Lambda cold dark matter (ΛCDM) model and one of its simplest extensions, featuring a constant dark energy equation of state parameter, w. Following a conservative approach, we put constraints on the total matter density parameter and the amplitude of density fluctuations, finding Ωm = 0.29 ± 0.06 and . Testing the alternative scenario, we derive w = −1.1 ± 0.2, in agreement with the ΛCDM model. These results are independent and complementary to those derived from standard cosmological probes, opening up new ways to identify the origin of potential tensions in the current cosmological paradigm.

Purification of saturated LiNO3 solution using titanium phosphate ion-exchanger: Equilibrium study

Sorption properties of titanium phosphate ion-exchanger (Li-TiOP) towards Cu2+, Co2+, Mn2+, Ni2+ and Cr3+ ions in saturated LiNO3 solution were investigated. Solid samples were characterized by XRD, SEM, TG, DSC, NGSP and elemental analysis. Concentrations of elements in the solutions were determined by AAS and ICP MS methods. The adsorption isotherms for studied metal ions were calculated using the Langmuir, Freundlich, Temkin and Nikolsky models. Necessity for allowing for the solvated state of the sorbate is shown in studying the sorption of metal ions. Selectivity of Li-TiOP towards studied ions is found to be described in the following order of Cr3+ > Cu2+ > Mn2+ > Co2+ > Ni2+ for all models. The change in the thermodynamic parameters of the sorption process is associated with that in the ionic potential of the sorbent. Titanium phosphate effectively removes trace concentrations of metal ions from multi-component solutions, resulting in achievement of LiNO3 purity level of > 99.999 wt.%.

Purity Level of Rare-Earth Metals (according to Materials in the Exhibition–Collection of Extrapure Substances)

Purity Level of Rare-Earth Metals (according to Materials in the Exhibition–Collection of Extrapure Substances)

Extraction and Physicochemical Characterization of <i>Adansonia digitata L.</i> Mucilage

Background: Adansonia digitata leaves are edible and they contain a significant amount of mucilage that has shown potentials for pharmaceutical application. However, there is paucity of information on this mucilage contained in its leaves.
 Objective: This study aimed to determine a suitable method for extraction of Adansonia digitata mucilage (ADM) as well as to characterize its physicochemical properties.
 Materials and Methods: ADM was extracted from the aqueous dispersion of the dried leaves powder of Adansonia digitata L. in water via precipitation with ethanol. Physicochemical characterization of ADM was based on viscosity, chemical composition, particle size characterization via QICPIC, Scanning Electron Microscopy (SEM), Attenuated Total Reflectance Fourier Transforms Infrared (ATR -FTIR) spectroscopy, Nuclear magnetic resonance (NMR), moisture content and Dynamic vapor sorption (DVS) studies as well as pH and aqueous solubility tests. In addition to this, colour of the mucilage and thermal analysis via DSC were used as criteria for selection of the most suitable method for extraction of ADM.
 Results: Colour and thermal analysis revealed a level of purity in the extraction process. The irregular needle like structures of ADM revealed by SEM was found to be mildly acidic with a high viscosity that is concentration dependent in aqueous medium. Thermal characterization revealed a glass transition (Tg) and melting temperatures (Tm) of 55.61 °C and 179.10 °C respectively. Finger prints of functional groups revealed azo aromatic groups and other chemical constituents of sugars including glucose, galactose, arabinose and rhamnose, and sugar acid form of galacturonic acid were identified by NMR. Moisture sorption provided insight into water sorption mechanism, processing, packaging and storage conditions of the mucilage.
 Conclusion: Extraction of ADM via a heat free method improved its colour and purity based on the technique used. The mucilage was found to be a highly viscous and hydrates rapidly with good gelling properties. In addition its moisture sorption characteristics and glass transition temperature gave insight into its stability, storage and packaging conditions. These properties reveal its potential for many pharmaceutical applications including binding, coating, gelling agents as well as matrix forming.

Improving the economical efficiency of a simulated-moving-bed process for biofuel production from agarose in red algae

A four-zone simulated-moving-bed (SMB) process has recently been applied to the recovery of galactose (biofuel-convertible monosugar) from agarose-hydrolysis output, which is part of agarose-based biofuel production process. To substantially improve the economical efficiency of the aforementioned biofuel production process, a new SMB process based on a three-zone advanced mode using fewer columns, pumps, and port-switching valves was proposed in this study. Its configuration and operation strategy were devised in a way to facilitate the complete regeneration of SMB solid phase against highly adsorbed impurities in the agarose-hydrolysis output while enhancing the separation margin between a key-impurity band front and a galactose product port in a feed-loaded separation zone. To investigate the advantages of such proposed SMB over the previous SMB, the two processes were optimized under equal conditions. It was found that the proposed process could significantly outperform the previous process in terms of processing rate, solvent usage, and galactose product yield while being in an advantageous position in the aspects of the equipment and maintenance costs and the potential for further acquisition of an industrially useful side-product. Furthermore, such advantage of the proposed process became greater as the required level of purity or processing rate increased.

The Selective Separation of Carnosic Acid and Rosmarinic Acid by Solid-Phase Extraction and Liquid-Liquid Extraction: A Comparative Study.

Rosmarinus officinalis leaves (ROLs) are widely used in the food and cosmetics industries due to their high antioxidant activity and fascinating flavor properties. Carnosic acid (CA) and rosmarinic acid (RA) are regarded as the characteristic antioxidant components of ROLs, and the selective separation of CA and RA remains a significant challenge. In this work, the feasibility of achieving the selective separation of CA and RA from ROLs by solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was studied and compared. The experiments suggested that SPE with CAD-40 macroporous resin as the adsorbent was a good choice for selectively isolating CA from the extracts of ROLs and could produce raw CA with purity levels as high as 76.5%. The LLE with ethyl acetate (EA) as the extraction solvent was more suitable for extracting RA from the diluted extracts of ROLs and could produce raw RA with a purity level of 56.3%. Compared with the reported column chromatography and LLE techniques, the developed SPE-LLE method not only exhibited higher extraction efficiency for CA and RA, but can also produce CA and RA with higher purity.

Acid-Assisted Separation of Cathodic Material from Spent Electric Vehicle Batteries for Recycling

The recycling of lithium-ion batteries presents challenges due to the complex composition of waste streams generated by current processes. Achieving higher purity levels, particularly in the reclamation of aluminium metal and transition metal black mass, is essential for improved valorisation. In this study, we propose a high-efficiency, low-energy, and environmentally friendly method using organic acids to separate cathodic black mass from the aluminium current collector. The acids selected in this study all show >86% peeling efficiency with acetic acid showing 100% peeling efficiency of black mass from the current collector. The recovered materials were subjected to X-ray diffraction, electron microscopy, and elemental analysis techniques. We show that oxalic-acid-treated material exhibited two distinct active material components with a minimal change in mass ratio compared to the untreated material. We show by elemental analysis of the leachates that the majority of critical materials were retained in the black mass and limited aluminium was leached during the process, with almost 100% of Al recovery achieved. This methodology enables the production of high-purity concentrated aluminium and critical metal feedstocks (Mn, Co, Ni, and Li) for further hydro-metallurgical processes, upcycling of the cathode material, and direct recycling. The proposed approach offers significant potential for enhancing valorization in lithium-ion battery recycling, facilitating efficient separation and optimal recovery of valuable metals.

Purification of hydrogen as green energy with pressure-vacuum swing adsorption (PVSA) with a two-layers adsorption bed using activated carbon and zeolite as adsorbent

Today, hydrogen is produced in refineries and petrochemicals using the methane reforming process, followed by a water gas shift reaction stage. The hydrogen produced has a purity of approximately 75%, and is purified further through an adsorption process. In this project, the feasibility of achieving a purity level greater than 90% through the use of a more effective adsorbent and the periodic process of pressure vacuum swing adsorption (PVSA) with a double-layer bed of active carbon and zeolite will be investigated. The design, simulation, and optimization of the hydrogen purification unit will also be conducted. The results of this study indicate that the proposed process can achieve a purity level of up to 97% for the output hydrogen.

Lipid membrane modulated control of magnetic nanoparticles within bacterial systems

Bacterial magnetosomes synthesized by the magnetotactic bacterium Magnetospirillum magneticum are suitable for biomedical and biotechnological applications because of their high level of chemical purity of mineral with well-defined morphological features and a biocompatible lipid bilayer coating. However, utilizations of native magnetosomes are not sufficient for maximum effectiveness in many applications as the appropriate particle size differs. In this study, a method to control magnetosome particle size is developed for integration into targeted technological applications. The size and morphology of magnetosome crystals are highly regulated by the complex interactions of magnetosome synthesis-related genes; however, these interactions have not been fully elucidated. In contrast, previous studies have shown a positive correlation between vesicle and crystal sizes. Therefore, control of the magnetosome vesicle size is tuned by modifying the membrane lipid composition. Exogenous phospholipid synthesis pathways have been genetically introduced into M.magneticum. The experimental results show that these phospholipids altered the properties of the magnetosome membrane vesicles, which yielded larger magnetite crystal sizes. The genetic engineering approach presented in this study is shown to be useful for controlling magnetite crystal size without involving complex interactions of magnetosome synthesis-related genes.

Physiochemical Characterization of Ethiopian Mined Kaolin Clay through Beneficiation Process

Kaolin mineral is a commercially solid powder with a comparatively low level of purity and is regularly used for a variety of applications, including filler, paints, ceramics, adsorbents, and paper. In Ethiopia, the kaolin clay mineral is significant for financial growth as the raw material used in the industry sector. However, slight consideration was given to the chemical, physical, mineralogical, and morphological properties of kaolin. In this study, the property of kaolin is investigated by using advanced instruments such as X-ray diffraction (XRD), X-ray fluorescence analysis (XRF), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential thermogravimetric analysis (DTA). Based on the XRF test, the main component of kaolin clay contains SiO2 (58.73%), Al2O3 (24.35%), K2O (5.36%), and other impurities, including Fe2O3 (2.06%) and TiO2 (0.13%). The FTIR spectra displayed the functional groups Si-O, Al-OH, Al-O, and Si-O-Al. The XRD diffractogram identified kaolin clay as the main mineral phase in the existence of quartz, halloysite, and chlorite.

Optimization of continuous particle separation in a symmetric sharp corner microchannel

The separation of circulating tumor cells from the bloodstream with high purity plays a crucial role in the treatment of cancer. Design and fabrication of cell sorters based on numerical models can lead to optimized cell sorters in terms of throughput, purity, and size. Based on a numerical model, a symmetric sharp corner microchannel was developed and optimized in this study to achieve a more compact cell sorter with high-purity output. Sharp corners in the microchannel generate centrifugal and inertial lift forces that cause particles (7.32 and 15.5 μm) to separate. The proposed numerical model was validated using experimental data. The proposed method reduced the device size by up to 19% while retaining a purity level of 95.45%. These results will have an impact on designing compact cell sorters with high purity output for implantable applications.

Purification of High-Purity Tin via Vertical Zone Refining

The present investigation delves into the potential of vertical zone refining as an effective purification technique for achieving high-purity tin (Sn) metal. The utilization of vertical zone refining offers distinct advantages over traditional horizontal zone refining, as it allows for enhanced control over the molten zone and solid–liquid interface, ultimately leading to superior impurity separation efficiency. The present study reveals that the solute partition coefficients (k0) of various impurity elements, such as Zn, Ag, Al, Mg, Ca, Ni, In, Co, Cu, As, Pb, Fe, and Bi, during the vertical zone refining process consistently demonstrate values below one. Notably, the partition coefficient of Sb deviates slightly from the others, being greater than one but approaching one. The authors achieve exceptional levels of purity in both the bottom and middle regions of the rod by subjecting the Sn melt to nine passes of vertical zone refining at a heating temperature of 405 °C and a downward pulling rate of 10 µm/s, resulting in purities exceeding 6N4. Furthermore, by evaluating the effective partition coefficients (keff), it was determined that impurity elements, such as Cu and Bi, closely approach their equilibrium partition coefficients, reaching values of approximately 0.492 and 0.327, respectively. To further enhance the purity of Sn metal and maximize product yield, we propose the utilization of electrolytic refining and vacuum distillation, with particular emphasis on the efficient separation of five specific elements, including Cu, Fe, As, Pb, and Sb. By elucidating these findings, this study not only contributes valuable insights into the efficacy of vertical zone refining as a purification technique for high-purity tin metal, but also offers important recommendations for refining strategies and impurity element separation.

Effect of thermal dynamics and column geometry of pressure swing adsorption on hydrogen production from natural gas reforming

The present study investigates hydrogen purification from a surrogate gas using spent coffee grounds as a medium. The study was conducted using Aspen adsorption software, and the process was examined under isothermal, adiabatic, and non-adiabatic conditions. The surrogate gas mixture comprised 70% hydrogen and 30% carbon dioxide and was introduced into two stainless steel chambers containing the coffee media. The pressure was altered from 101.3 to 150 kPa as the chamber underwent the adsorption process. At an adsorption time of 60 s, all three conditions exhibited similar levels of purity and recovery, with the isothermal mode producing the highest values. Additionally, the effect of heat dissipation and column geometry on the adsorption performance was investigated by comparing the conventional isothermal column with the rectangular non-adiabatic plate column. The plate column is rectangular, with two chambers that use the heat generated during adsorption to regenerate the opposite column during the blowdown step. This effect was evaluated under different adsorption times of 30–180 s and hydrogen feed concentrations of 70–90%. The plate column had higher hydrogen purity and recovery of 99.99% and 77.41%, respectively, compared to 99.56 and 71.12% of the cylindrical column. Overall, the results indicate that spent coffee grounds can be effectively used as a medium to purify hydrogen from a surrogate gas mixture. A rectangular non-adiabatic plate column can further enhance the purification process by improving purity and recovery responses.

Prognostic value of amino acid metabolism-related gene expression in invasive breast carcinoma.

An increasing number of studies indicated that metabolic reprogramming of amino acid metabolism may either promote or inhibit tumor progression. The purpose of this study was to investigate the ability of a gene risk signature associated with amino acid metabolism to predict the prognosis and immune characteristics of invasive breast carcinoma. LASSO Cox regression analysis was performed to construct and validate the prognostic risk signature based on the expression of 9 amino acid metabolism-related genes. The predictive value of the signature, immune characteristics, and chemotherapeutic drugs was also predicted. Finally, 9 significant genes were examined in MDA-MB-231 and MCF-7 cells, and the predicted chemotherapeutic drugs were also verified. The prognosis of the low-risk group was better than that of the high-risk group. The areas under the curve (AUCs) at 1, 2, and 3 years were 0.852, 0.790, and 0.736, respectively. In addition, the GSEA results for KEGG and GO revealed that samples with a high-risk score exhibited a variety of highly malignant manifestations. The high-risk group was characterized by an increased number of M2 macrophages, a high level of tumor purity, low levels of APC co-stimulation, cytolytic activity, HLA, para-inflammation, and type I IFN response. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) confirmed that MDA-MB-231 and MCF-7 cells express 9 amino acid metabolism-related genes differently. In addition, cell experiments were conducted to examine the effect of cephaeline-induced on cell viability, migration ability, and protein expression of the PI3K/AKT signaling pathway and HIF-1α. We established a risk signature based on 9 amino acid metabolism-related genes for invasive breast carcinoma. Further analyses revealed that this risk signature is superior to other clinical indexes in survival prediction and that the subgroups identified by the risk signature exhibit distinct immune characteristics. Cephaeline was determined to be a superior option for patients in high-risk groups.

A comprehensive review on current trends and development of biomethane production from food waste: Circular economy and techno economic analysis

Biogas production from food waste with anaerobic digestion process and co-digestion process obtained high purity of biogas. Food waste consists of proteins, carbohydrates, inorganic compounds, fibre, sugars, and lipids. Fossil fuels have caused some environmental and human health problems, such as effects of global warming, greenhouse gas emissions. Biogas production is a simple process and is purified into methane and used in many applications, heat, electricity and vehicle fuel. Different types of food waste are collected and processed into biogas, which is essential for human use and as an alternative to fossil fuels. The collection of food waste, pre-treatment process, production of biogas, purification of biogas, upgradation of biomethane, and circular bioeconomy are clearly explained. Anaerobic digestion and co-digestion processes have increased biomethane yield, up gradation and purification of biogas have also been discussed. Five different types of upgradation processes are included, such as physical scrubbing, chemical scrubbing, pressure swing adsorption, membrane separation, and cryogenic separation. The upgradation process and the purity level also mentioned in this review, it represents the biomethane quality. Techno economic effects and circular bioeconomy levels are addressed in this review. Life cycle assessment, life cycle impact analysis and environmental impact level are discussed. However, Challenges and future perspectives of biogas production and to improve the biomethane purity level. 89% of the biogas production is obtained from fruit waste with anaerobic digestion, after the upgradation process, 99% purity of biomethane is separated.

Partial Characterization and Immunomodulatory Effects of Exopolysaccharides from Streptococcus thermophilus SBC8781 during Soy Milk and Cow Milk Fermentation.

The immunomodulatory properties of exopolysaccharides (EPSs) produced by Streptococcus thermophilus have not been explored in depth. In addition, there are no comparative studies of the functional properties of EPSs produced by streptococci in different food matrices. In this work, EPSs from S. thermophilus SBC8781 were isolated after soy milk (EPS-s) or cow milk (EPS-m) fermentation, identified, and characterized in their abilities to modulate immunity in porcine intestinal epithelial cells. Fresh soy milk and cow milk were inoculated with S. thermophilus SBC8781 (7 log CFU/mL) and incubated at 37 °C for 24 h. The extraction of EPSs was performed by the ethanol precipitation method. Analytical techniques, including NMR, UV-vis spectroscopy, and chromatography, identified and characterized both biopolymer samples as polysaccharides with high purity levels and similar Mw. EPS-s and EPS-m had heteropolysaccharide structures formed by galactose, glucose, rhamnose, ribose, and mannose, although with different monomer proportions. On the other hand, EPS-s had higher quantities of acidic polymer than EPS-m. The biopolymer production of the SBC8781 strain from the vegetable culture broth was 200-240 mg/L, which was higher than that produced in milk, which reached concentrations of 50-70 mg/L. For immunomodulatory assays, intestinal epithelial cells were stimulated with 100 µg/mL of EPS-s or EPS-m for 48 h and then stimulated with the Toll-like receptor 3 agonist poly(I:C). EPS-s significantly reduced the expression of IL-6, IFN-β, IL-8, and MCP-1 and increased the negative regulator A20 in intestinal epithelial cells. Similarly, EPS-m induced a significant reduction of IL-6 and IL-8 expressions, but its effect was less remarkable than that caused by EPS-s. Results indicate that the structure and the immunomodulatory activity of EPSs produced by the SBC8781 strain vary according to the fermentation substrate. Soy milk fermented with S. thermophilus SBC8781 could be a new immunomodulatory functional food, which should be further evaluated in preclinical trials.