Types Of Reagents Research Articles

Correlation of Flotation Recoveries and Bubble–Particle Attachment Time for Dodecyl Ammonium Hydrochloride/Frother/Quartz Flotation System

Recent studies in the flotation of fine particles have necessitated new techniques and analyses for developing various strategies. Particularly, the improvements in flotation chemistry including the selection of the type of frother, collector, and other reagents have become very significant. In this study, the effect of different commercial polypropylene glycol frothers (PPG200, 400, and 600) in the presence of dodecylammonium hydrochloride (DAH) was investigated for their contribution to flotation recoveries and bubble–particle attachment time values of fine quartz minerals. Zeta potential measurements with DAH were also carried out as a function of pH and reagent concentration to justify the effect of collector usage alone on the charge of particles. A linear increase in flotation recoveries against collector concentration, e.g., 7.4% recovery at 1 × 10−5 mol/L DAH and 65.4% recovery at 1 × 10−3 mol/L DAH, was obtained. In this context, the contribution of frothers was particularly important in that a recovery of 15.91% in the absence of the frother and a modest increase to 19.70% was obtained upon the addition of PPG600 at its critical coalescence concentration (CCC) of 3 ppm. Finally, a strong correlation was found between the bubble–particle attachment time and flotation recovery as a function of collector concentration (lowest attachment time vs. highest flotation recovery). The latter correlation is very promising because bubble attachment time leads to various micro-mechanisms in flotation including bubble film thinning, bubble rupture, and induction time, and consequently, frother efficiency in the presence and absence of a collector. As a result, the experimental findings were gathered to achieve a consistent base for further fundamental studies on the application of the synergistic effect of frothers and collectors in the flotation of fine particles.

Insights Into the Synthetic Strategies, Biological Activity, and Structure- Activity Relationship of Pyridine and Analogs: A Review

Abstract: Based on various research reports, pyridine possesses a wide range of pharmacological activities along with many other industrial applications. Because of its diverse applications, pyridine moiety is the center of attraction for researchers, and many patents have been granted focusing on it. Several synthetic protocols, such as cyclo-condensation, cyclization, cycloaddition, electrolysis, etc., were used by researchers to synthesize pyridine and analogs. Each synthetic protocol has merits and demerits and requires several types of reagents, catalysts, and reaction conditions. So, there is always a need for careful analysis of reported synthetic protocols whenever researchers like to initiate research on synthesizing pyridine and its analogs. The therapeutic activity of successfully marketed drugs might be possible because of the presence of pyridine in their structure. Any small alteration in the structure of the medicinal compounds may produce a major change in their pharmacological action. So, the correlation between the structure of its analogs with biological activity is also important. The proposed article also includes recently reported pharmacological activities and the structureactivity relationship of pyridine and its analogs. This article aims to help the researchers by highlighting recently reported methods for synthesizing pharmacologically useful pyridine analogs and their merits.

P127 Validation of HLA typing reagents and analysis software: Can we do better to prevent erroneous typing results?

P127 Validation of HLA typing reagents and analysis software: Can we do better to prevent erroneous typing results?

A method of designing an SNCR installation for small pulverized coal-fired boilers on the example of OP-50 boiler

Small pulverized coal-fired heating boilers are popular in heating and industrial applications. Recent changes in emissions limits forced interest in clean-up technologies dedicated for such a boilers, which previously were not included in regulations. The paper presents a method of designing an Selective Non Catalytic Reduction (SNCR) installation for small pulverized coal-fired boilers on the example of OP-50 boiler. Among main challenges during technology development and adjustment injection lances type, position, and operating parameters including reagent type and concentration can be enumerated. The designing process covered mainly following parts: object tests, temperature distribution determination (including balance calculations and computational fluid dynamics (CFD) modelling) leading to lances position determination, injection nozzles designing, installation tuning and calibration. Final measurements confirmed the ability of designed system to reduce NOx concentration in the flue gases below limit given in regulations.

Synthesis of Iron Oxides and Influence on Final Sizes and Distribution in Bacterial Cellulose Applications.

Iron oxide nanoparticles have been investigated due to their suitable characteristics for diverse applications in the fields of biomedicine, electronics, water or wastewater treatment and sensors. Maghemite, magnetite and hematite are the most widely studied iron oxide particles and have ferrimagnetic characteristics. When very small, however, these particles have superparamagnetic properties and are called superparamagnetic iron oxide nanoparticles (SPIONs). Several methods are used for the production of these particles, such as coprecipitation, thermal decomposition and microemulsion. However, the variables of the different types of synthesis must be assessed to achieve greater control over the particles produced. In some studies, it is possible to compare the influence of variations in the factors for production with each of these methods. Thus, researchers use different adaptations of synthesis based on each objective and type of application. With coprecipitation, it is possible to obtain smaller, more uniform particles with adjustments in temperature, pH and the types of reagents used in the process. With thermal decomposition, greater control is needed over the time, temperature and proportion of surfactants and organic and aqueous phases in order to produce smaller particles and a narrower size distribution. With the microemulsion process, the control of the confinement of the micelles formed during synthesis through the proportions of surfactant and oil makes the final particles smaller and less dispersed. These nanoparticles can be used as additives for the creation of new materials, such as magnetic bacterial cellulose, which has different innovative applications. Composites that have SPIONs, which are produced with greater rigour with regards to their size and distribution, have superparamagnetic properties and can be used in medical applications, whereas materials containing larger particles have ferromagnetic applications. To arrive at a particular particle with specific characteristics, researchers must be attentive to both the mechanism selected and the production variables to ensure greater quality and control of the materials produced.

Study on the effect of inorganic and organic sodium on coal spontaneous combustion

In order to investigate the effect of sodium in coal spontaneous combustion, different types of inorganic and organic sodium were added to the raw coal to analyze the changes of spontaneous combustion characteristics of coal samples. The combustion characteristics parameters of each group of coal samples were calculated by simulating the spontaneous combustion reaction process of coal through programmed warming thermogravimetric experiments, and the results showed that the combustibility index of coal samples loaded with various types of sodium-containing reagents increased by 8.32 %–45.37 %, and the combustion characteristics index decreased by 13.82 %–39.15 %. It indicates that inorganic sodium salts and organic sodium salts promote the combustion of coal in the low temperature stage and inhibit it in the high temperature stage. Subsequently, the changes of characteristic functional groups in coal during combustion after loading sodium were analyzed by using in-situ infrared spectroscopy experiments, and it was concluded that sodium in organic salts would combine with peroxyl radicals and thus inhibit the oxidation process of oxygen-containing functional groups in coal; sodium in inorganic salts would replace hydrogen in carboxyl and hydroxyl groups and thus promote the oxidation reaction of coal. The results of the study can provide some theoretical basis for the development of new coal spontaneous combustion inhibitors with specific functions.

Reagent Effects on the Activated Partial Thromboplastin Time Clot Waveform Analysis: A Multi-Centre Study.

(1) Background: The activated partial thromboplastin time (APTT)- based clot waveform analysis (CWA) quantitatively extends information obtained from the APTT waveform through its derivatives. However, pre-analytical variables including reagent effects on the CWA parameters are poorly understood and must be standardized as a potential diagnostic assay. (2) Methods: CWA was first analysed with patient samples to understand reagent lot variation in three common APTT reagents: Pathromtin SL, Actin FS, and Actin FSL. A total of 1055 healthy volunteers were also recruited from seven institutions across the Asia-Pacific region and CWA data were collected with the Sysmex CS analysers. (3) Results: CWA parameters varied less than 10% between lots and the linear mixed model analysis showed few site-specific effects within the same reagent group. However, the CWA parameters were significantly different amongst all reagent groups and thus reagent-specific 95% reference intervals could be calculated using the nonparametric method. Post-hoc analysis showed some degree of influence by age and gender with weak correlation to the CWA (r < 0.3). (4) Conclusions: Reagent type significantly affects APTT-based CWA with minimal inter-laboratory variations with the same coagulometer series that allow for data pooling across laboratories with more evidence required for age- and gender-partitioning.

Modification of Starches and Flours by Acetylation and Its Dual Modifications: A Review of Impact on Physicochemical Properties and Their Applications.

Various modification treatments have been carried out to improve the physicochemical and functional properties of various types of starch and flour. Modification by acetylation has been widely used to improve the quality and stability of starch. This review describes the effects of acetylation modification and its dual modifications on the physicochemical properties of starch/flour and their applications. Acetylation can increase swelling power, swelling volume, water/oil absorption capacity, and retrogradation stability. The dual modification of acetylation with cross-linking or hydrothermal treatment can improve the thermal stability of starch/flour. However, the results of the modifications may vary depending on the type of starch, reagents, and processing methods. Acetylated starch can be used as an encapsulant for nanoparticles, biofilms, adhesives, fat replacers, and other products with better paste stability and clarity. A comparison of various characteristics of acetylated starches and their dual modifications is expected to be a reference for developing and applying acetylated starches/flours in various fields and products.

Versatile Tetrasilane for Time-Controlled Palladium-Catalyzed Divergent Synthesis of Silacycles via C-H Activation.

Transition-metal-catalyzed intermolecular annulation of silicon reagents with organic molecules is still underdeveloped due to the scarcity of silicon reagent types and their diverse reactivity. Herein, a readily accessible silicon reagent (octamethyl-1,4-dioxacyclohexasilane) has been developed for divergent synthesis of silacycles via time-controlled palladium-catalyzed cascade C-H silacyclization. This protocol enables the rapid and selective transformation of acrylamides into spirosilacycles with different ring sizes, including benzodioxatetrasilecines, benzooxadisilepines, and benzosiloles, in moderate to good yields through a time switch. Notably, the tetrasilane reagent can also be utilized for C-H silacyclization of 2-halo-N-methacryloylbenzamides and 2-iodobiphenyls, leading to diverse fused silacycles. Furthermore, several synthetic transformations of products are achieved. A series of mechanistic studies demonstrate the transformation relationships and possible pathways among ten-, seven-, and five-membered silacycles.

Novel blood typing method by discrimination of hemagglutination and rouleaux using an erythrocyte aggregometer.

In pretransfusion blood typing, pretreatments such as centrifugation and suspension of red blood cells (RBCs) and mixing them with sufficient amounts of reagents are required, but these steps are time-consuming and costly. Aiming to develop a new blood typing method that requires no dilution and only a small amount of reagent, we attempted to determine blood type using syllectometry, an easy-to-use and rapid optical method for measuring the RBC aggregation that occurs when blood flow is abruptly stopped in a flow channel. Samples of whole blood from 20 healthy participants were mixed with antibody reagents for blood typing at mixing ratios of 2.5% to 10% and measured with a syllectometry device. Amplitude (AMP), one of the aggregation parameters, showed significant differences between agglutination and non-agglutination samples at mixing ratios from 2.5% to 10%. Although there were significant individual differences in aggregation parameters, calculation of AMP relative to that of blood before reagent mixing reduced the individual differences and enabled determination of blood type in all participants. This new method enables blood typing with a small amount of reagent, without the time-consuming and labor-intensive pretreatments such as centrifugation and suspension of RBCs.

Functionalized Ordered Mesoporous MCM-48 Silica: Synthesis, Characterization and Adsorbent for CO2 Capture.

The ordered mesoporous silica MCM-48 with cubic Ia3d structure was synthesized using the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) as a template agent and tetraethylorthosilicate (TEOS) as a silica source. The obtained material was first functionalized with (3-glycidyloxypropyl)trimethoxysilane (KH560); further, two types of amination reagents were used: ethylene diamine (N2) and diethylene triamine (N3). The modified amino-functionalized materials were characterized by powder X-ray diffraction (XRD) at low angles, infrared spectroscopy (FT-IR) and nitrogen adsorption-desorption experiments at 77 K. Characterization from a structural point of view reveals that the ordered MCM-48 mesoporous silica has a highly ordered structure and a large surface area (1466.059 m2/g) and pore volume (0.802 cm3/g). The amino-functionalized MCM-48 molecular sieves were tested for CO2 adsorption-desorption properties at different temperatures using thermal program desorption (TPD). Promising results for CO2 adsorption capacities were achieved for MCM-48 sil KH560-N3 at 30 °C. At 30 °C, the MCM-48 sil KH560-N3 sample has an adsorption capacity of 3.17 mmol CO2/g SiO2, and an efficiency of amino groups of 0.58 mmol CO2/mmolNH2. After nine adsorption-desorption cycles, the results suggest that the performance of the MCM-48 sil KH N2 and MCM-48 sil KH N3 adsorbents is relatively stable, presenting a low decrease in the adsorption capacity. The results reported in this paper for the investigated amino-functionalized molecular sieves as absorbents for CO2 can be considered as promising.

Surface modification of polycaprolactone nanofibers through hydrolysis and aminolysis: a comparative study on structural characteristics, mechanical properties, and cellular performance

Hydrolysis and aminolysis are two main commonly used chemical methods for surface modification of hydrophobic tissue engineering scaffolds. The type of chemical reagents along with the concentration and treatment time are main factors that determine the effects of these methods on biomaterials. In the present study, electrospun poly (ℇ-caprolactone) (PCL) nanofibers were modified through hydrolysis and aminolysis. The applied chemical solutions for hydrolysis and aminolysis were NaOH (0.5–2 M) and hexamethylenediamine/isopropanol (HMD/IPA, 0.5–2 M) correspondingly. Three distinct incubation time points were predetermined for the hydrolysis and aminolysis treatments. According to the scanning electron microscopy results, morphological changes emerged only in the higher concentrations of hydrolysis solution (1 M and 2 M) and prolonged treatment duration (6 and 12 h). In contrast, aminolysis treatments induced slight changes in the morphological features of the electrospun PCL nanofibers. Even though surface hydrophilicity of PCL nanofibers was noticeably improved through the both methods, the resultant influence of hydrolysis was comparatively more considerable. As a general trend, both hydrolysis and aminolysis resulted in a moderate decline in the mechanical performance of PCL samples. Energy dispersive spectroscopy analysis indicated elemental changes after the hydrolysis and aminolysis treatments. However, X-ray diffraction, thermogravimetric analysis, and infrared spectroscopy results did not show noticeable alterations subsequent to the treatments. The fibroblast cells were well spread and exhibited a spindle-like shape on the both treated groups. Furthermore, according to the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, the surface treatment procedures ameliorated proliferative properties of PCL nanofibers. These findings represented that the modified PCL nanofibrous samples by hydrolysis and aminolysis treatments can be considered as the potentially favorable candidates for tissue engineering applications.

光化学的活性化を駆動力としたヨウ素を利用する新規分子変換反応の開発

Effective use of the light that surrounds us is the hottest research topic in all fields, including the energy field. Light is the means by which reactions occur, and can be thought of as a “type of reagent.” Since light has no shape or weight, it is a clean substance that does not leave any residue, and can be one of the most important methods for investigating processes that reduce environmental impact. Against this background, the authors have been conducting research aiming at the development of novel molecular transformation reactions driven by photochemical activation of representative elements. In this study, we focused on iodine, which is easy to handle, has low toxicity, and is highly responsive to visible light. That is to say, iodine and carbon-iodine bonds readily respond to light energy as small as visible light and undergo bond cleavage to generate radical species. By applying this phenomenon to fine organic synthesis reactions, the authors have succeeded in developing a methodology for easily synthesizing compounds such as phenacyl halides, cyclopropanes, and lactones, which have high industrial value, from light energy and inexpensive raw materials.

A Traceless Chiral Shift Reagent Based on Nonbonding Interactions with Single‐Handed Helical Poly(quinoxaline‐2,3‐diyl)

AbstractA single‐handed poly(quinoxaline‐2,3‐diyl) (PQX) has been found to serve as a new type of chiral shift reagent (CSR) for determining the enantiomeric ratio by NMR spectroscopy. Even though there is no specific binding site in the PQX, its nonbonding interaction with chiral analytes leads to a significant shift of the NMR chemical shift, allowing quantification of the enantiomeric ratio. The new type of CSR has the advantages of a wide scope of analytes including ethers, haloalkanes, and alkanes, easy tunability of the degree of chemical shifts by measurement temperature, and erasability of proton signals of CSR because of the short spin‐spin (T2) relaxation of the macromolecular scaffold.

Quantification of Health Claim-Relevant Tyrosol and Hydroxytyrosol after Direct Hydrolysis Improves Customer Understanding and Mitigates Market Distortion

The EFSA-approved claim that olive oil is beneficial for cardiovascular health suffers from ambiguities that lead to a vague and potentially subjective interpretation of the underlying analytical data. Misunderstandings among customers, but also market distortions are possible consequences. In this study, a rapid and simple analytical technique is presented that circumvents the ambiguity by measuring levels of putative health-promoting compounds as the equivalent of tyrosol and hydroxytyrosol, cleaving such moieties from more complex constituents such as oleuropein and oleocanthal. Since the direct hydrolysis of the olive oil is the central element of the process, the reaction temperature, time, reagent concentration and reagent type were optimized. In addition, the influence of co-solvents, which might support the intermittent miscibility of the two phases during hydrolysis, was investigated. The analytical and economic implications are discussed particularly in the context of a commonly used technique.

Overview of the serologic and molecular basis of D variants with a focus on D variants in the Indian population.

Complexities of D within the Rh blood group system have long been recognized, initially using basic serologic testing and, more recently, using advanced and sensitive typing reagents. Discrepancies may arise when an individual carries a D antigen showing altered D antigen expression. These D variants are clinically important, since they may lead to production of anti-D in the carrier and induce alloimmunization in D- recipients, making their correct identification imperative. For clinical purposes, D variants can be classified into three groups: weak D, partial D, and DEL. The problem surrounding proper characterization of D variants exists because routine serologic tests are sometimes inadequate to detect D variants or resolve discrepant or ambiguous D typing results. Today, molecular analysis has revealed more than 300 RH alleles and is a better method for investigating D variants. Global distribution of variants differs, as observed in European, African, and East Asian populations. Discovery of the novel RHD*01W.150 (weak D type 150) with a nucleotide change of c.327_487-4164dup is proof. This variant, the result of an insertion of a duplicated exon 3 between exons 2 and 4 in the same orientation, was detected in more than 50 percent of Indian D variant samples in a 2018 study. The outcome of studies worldwide has led to the recommendation to manage D variant individuals as D+ or D- according to RHD genotype. The policies and workup with respect to D variant testing in donors, recipients, and prenatal women differ among blood banks, depending on type of variants predominantly encountered. Thus, a general genotyping protocol cannot be followed globally, and an Indian-specific RHD genotyping assay (multiplex polymerase chain reaction) designed to detect D variants frequently found in the Indian population was developed to save time and resources. This assay is also helpful for detecting several partial and null alleles. Identification of D variants by serology and characterization by molecular testing need to go hand-in-hand for better and safer transfusion practices.

A Mini Review on Flotation Techniques and Reagents Used in Graphite Beneficiation

Due to its numerous and major industrial uses, graphite is one of the significant carbon allotropes. Refractories and batteries are only a couple of the many uses for graphite. A growing market wants high-purity graphite with big flakes. Since there are fewer naturally occurring high-grade graphite ores, low-grade ores must be processed to increase their value to meet the rising demand, which is predicted to increase by &gt;700% by 2025 due to the adoption of electric vehicles. Since graphite is inherently hydrophobic, flotation is frequently used to beneficiate low-grade ores. The pretreatment process, both conventional and unconventional; liberation/grinding methods; flotation methods like mechanical froth flotation, column flotation, ultrasound-assisted flotation, and electroflotation; and more emphasis on various flotation reagents are all covered in this review of beneficiation techniques. This review also focuses on the different types of flotation reagents that are used to separate graphite, such as conventional reagents and possible nonconventional environmentally friendly reagents.

Hyperplexing Approaches for up to 45-Plex Quantitative Proteomic Analysis.

Isobaric labeling has emerged as an indispensable quantitative proteomic approach for its unprecedented multiplexing capacity in a single analysis. Currently, different hyperplexing approaches have been developed to meet the demand for the increasing sample size in large-scale cohort analysis. In this report, we present a tribrid hyperplexing approach by the combinatorial use of three types of isobaric reagents, a novel isobaric tag 16-plex (IBT16) reagent and the widely used tandem mass tag (TMT; TMT11) and TMTpro (TMT18) reagents. After the determination of labeling efficiency and the optimization of testing conditions, we systematically evaluated the identification and quantification performance of the three labeling reagents in both independent and combinatorial manners using the mixtures of E.coli and HeLa peptides with different ratios. Our results reveal that the three reagents are quite similar in all testing aspects despite some differences, and the combination use of the three reagents could expand the multiplexing capacity to up to 45-plex. Furthermore, we conclude the advantages of IBT16 in the combination use and the preferred combinations for different practical applications. Data are available via ProteomeXchange with identifier PXD037498.

Extracellular matrix-derived scaffolds in constructing artificial ovaries for ovarian failure: a systematic methodological review.

What is the current state-of-the-art methodology assessing decellularized extracellular matrix (dECM)-based artificial ovaries for treating ovarian failure? Preclinical studies have demonstrated that decellularized scaffolds support the growth of ovarian somatic cells and follicles both in vitro and in vivo. Artificial ovaries are a promising approach for rescuing ovarian function. Decellularization has been applied in bioengineering female reproductive tract tissues. However, decellularization targeting the ovary lacks a comprehensive and in-depth understanding. PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials were searched from inception until 20 October 2022 to systematically review all studies in which artificial ovaries were constructed using decellularized extracellular matrix scaffolds. The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Two authors selected studies independently based on the eligibility criteria. Studies were included if decellularized scaffolds, regardless of their species origin, were seeded with ovarian cells or follicles. Review articles and meeting papers were removed from the search results, as were articles without decellularized scaffolds or recellularization or decellularization protocols, or control groups or ovarian cells. The search returned a total of 754 publications, and 12 papers were eligible for final analysis. The papers were published between 2015 and 2022 and were most frequently reported as coming from Iran. Detailed information on the decellularization procedure, evaluation method, and preclinical study design was extracted. In particular, we concentrated on the type and duration of detergent reagent, DNA and extracellular matrix detection methods, and the main findings on ovarian function. Decellularized tissues derived from humans and experimental animals were reported. Scaffolds loaded with ovarian cells have produced estrogen and progesterone, though with high variability, and have supported the growth of various follicles. Serious complications have not been reported. A meta-analysis could not be performed. Therefore, only data pooling was conducted. Additionally, the quality of some studies was limited mainly due to incomplete description of methods, which impeded specific data extraction and quality analysis. Several studies that used dECM scaffolds were performed or authored by the same research group with a few modifications, which might have biased our evaluation. Overall, the decellularization-based artificial ovary is a promising but experimental choice for substituting insufficient ovaries. A generic and comparable standard should be established for the decellularization protocols, quality implementation, and cytotoxicity controls. Currently, decellularized materials are far from being clinically applicable to artificial ovaries. This study was funded by the National Natural Science Foundation of China (Nos. 82001498 and 81701438). The authors have no conflicts of interest to declare. This systematic review is registered with the International Prospective Register of Systematic Reviews (PROSPERO, ID CRD42022338449).

Chitosan-Bead-Encapsulated Polystyrene Sulfonate for Adsorption of Methylene Blue and Regeneration Studies: Batch and Continuous Approaches.

Textile industrialization causes water pollution due to the discharge of industrial effluents into the environment. To reduce the impact of industrial effluent, it must be treated in wastewater treatment plants before discharge into rivers. Among all wastewater treatment approaches, the adsorption process is one method to remove pollutants from wastewater, but it has some limitations in term of reusability and ionic selective adsorption properties. In this study, we prepared cationic poly (styrene sulfonate) (PSS)-incorporated anionic chitosan beads synthesized using the oil-water emulsion coagulation method. The produced beads were characterized using FESEM and FTIR analysis. In batch adsorption studies, the PSS-incorporated chitosan beads exhibited monolayer adsorption processes, that is, exothermic processes that occur spontaneously at low temperatures, which were analyzed based on the adsorption isotherms, adsorption kinetics, and thermodynamics model fittings. The presence of PSS enables cationic methylene blue dye to adsorb to the anionic chitosan structure via electrostatic interaction between the sulfonic group and the dye molecule. The maximum adsorption capacity of PSS-incorporated chitosan beads achieved 42.21 mg/g, as calculated from the Langmuir adsorption isotherm. Finally, the PSS-incorporated chitosan beads demonstrated good regeneration with different types of reagents, especially using sodium hydroxide as a regeneration reagent. With the use of sodium hydroxide regeneration of this adsorbent material, a continuous adsorption setup also demonstrated that PSS-incorporated chitosan beads can be reused for methylene blue adsorption for up to three cycle processes.