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The basic chemical structure of most prostate specific membrane antigen (PSMA) inhibitors which are now in pre-clinical and clinical studies is Glu-Ureido-based peptides. Synthesis of urea-based PSMA inhibitors includes two steps: 1- isocyanate intermediate formation and 2- urea bond formation. In current methods, isocyanate is formed in liquid phase and then reacts with amine existing in liquid phase or bound to solid phase for urea bond formation. In this study, we developed a new facile method for formation of both isocyanate and urea on solid phase under standard peptide coupling conditions. The solid phase-bound isocyanate served as intermediate to form urea bond. To monitor reaction progress qualitative test (Kaiser Test) and On-Bead FT-IR spectroscopy were used. The structure of Glutamate-Urea-Lysine (EUK) was confirmed using LC-Mass and 1H-NMR. This novel method successfully was applied to synthesize of another urea-based peptide containing a sequence of Glu-Urea-Lys (OMe)- GABA-Tyr-Tyr-GABA and the bifunctional linker hydrazinonicotinamide (HYNIC) as well. [ABSTRACT FROM AUTHOR]

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For many biomedical and catalytic applications, such as encapsulation of proteins/enzymes in nanoparticles (NPs), it is preferable to have well-dispersed small NPs that are stable in solution and behave quasi-homogeneously. However, conventional liquid phase methods for small-NP synthesis and functionalization usually face great difficulties in separation/purification and recycling. In addition, controlling the orientation of proteins inside NPs is also a crucial issue to maximize the activity of the encapsulated proteins. Herein, we report a solid phase method to solve these problems. Using His-tagged proteins as cores, well-dispersed core-shell silica NPs are facilely synthesized and functionalized in a column. The core His-tagged proteins are kept bound on the surface of the resin beads in the column during the entire process, making the separation/purification of NPs and their precursors during the multiple-step process as simple as a few-minutes procedure of draining and washing the column. Each obtained silica NP has an adjustable eccentric core-shell structure with only one His-tag sticking out of the particle. This single His-tag on the surface of each NP not only makes it easy for addressable and stoichiometric functionalization of the NP but also provides an easy way to reversibly assemble NPs into dimers or be oriented on the surface of large particles. Notably, this solid phase approach also provides a versatile means to control the orientation of proteins inside NPs, and the His-tag makes it easy to recycle those well-dispersed small NPs. [ABSTRACT FROM AUTHOR]

LiFePO4/reduced graphene oxide composites (LiFePO4/RGO) were synthesized via a simple solid phase combined with carbothermal reduction method. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Furthermore, cyclic voltammetry (CV), electrochemicaal impendence spectroscopy (EIS) and galvanostatic charge/discharge tests were conducted to further study the electrochemical properties of LiFePO4/RGO composites. The initial discharge specific capacity of LiFePO4/RGO was 151.5 mAh g−1 at 0.1C, and after 50 cycles, it still remains 149.2 mAh g−1. The results reveal that LiFePO4/RGO composites improved the discharge specific capacity and rate charge-discharge performance. [ABSTRACT FROM AUTHOR]

Sorption and phase distribution of 54Mn, 59Fe, 60Со, 106Ru, 125Sb, 137Cs, 144Се, 154,155Eu, and 235,238U radionuclides in contact of the Pb-Bi melt with the steel surface were studied. Radionuclides of the elements with the minimal oxygen affinity (Ru, Te, and Sb) remain mainly in the coolant melt and are weakly sorbed onto the solid phase. The other fission product radionuclides having higher oxygen affinity are sorbed onto the surface of steel structural materials. The sorption increases at 350-400°С. [ABSTRACT FROM AUTHOR]

• Anode showed larger overpotential at higher temperature due to the pore diffusion resistance. • Gas-phase transport processes are dominant in the anode. • Cathode showed less overpotential at higher temperature because of the enlarged solid-phase mass transfer rate. • Overpotential analysis at each electrodes are available with ISA and RA methods. Understanding the temperature dependence of electrode reactions is attempted with a commercial 100 cm2 class planar solid oxide fuel cell. Experimental investigations are conducted using a specially designed setup, i.e., inert gas step addition (ISA) and reactant gas step addition (RA) methods, to measure the electrode overpotential behaviour at temperatures ranging from 923 to 1073 K. The ISA reveals that the gas-phase mass transfer resistance at the anode is more substantial and becomes immensely larger with increasing temperature due to the effect of pore diffusion resistance (PDR). On the other hand, the gas-phase mass transfer resistance of the cathode shows an unclear dependence on temperature, indicating little resistance in the cathode. The RA method represents that the H 2 -inducing mass transfer resistance increases with increasing temperature due to the PDR effect, while the O 2 -inducing mass transfer resistance decreases with increasing temperature because of the reducing solid-phase mass transfer resistance of oxide ions. [ABSTRACT FROM AUTHOR]

Headspace solid phase microextraction and purge and trap analysis were used for the determination of volatiles in beer. These methods were compared with the analysis of unconcentrated gas phase and liquid extraction. Solid phase microextraction proved to be the most useful and was investigated more closely. Volatiles were isolated by the means of different combinations of sorbents, sorption was performed at various temperatures and times. The addition of salt to the sample and stirring of the sample were examined to enhance the analyte concentration in the gas phase. Ultrasonic bath and filtration were tested to remove carbon dioxide. Not all methods improved the sorption of volatiles. Stirring was characterised by low repeatability and ultrasonic bath causes to the loss of volatile analytes. Distribution constants of volatiles depend on their boiling points and thus different sorption temperatures are suitable for different substances.

Many lipophilic pharmaceuticals may be sorbed in solid phases, leading to different photochemical behaviors. This study investigated the photochemistry of ciprofloxacin in a solid-phase system and compared it to that in a water-phase system. Kaolinite was used as the model solid matrix. The photolysis of ciprofloxacin in kaolinite fits pseudo-first-order kinetics for thicknesses less than 199 μm, and the rate constants k decreased from 0.0154 to 0.0016 min as the thickness of the layer increased. Unlike the aqueous phase, two-step degradation processes were observed for all kaolinite layer thicknesses (14-199 μm), and the pseudo-first-order constant at the surface of the kaolinite layer was smaller than that in the water phase. , a similar photolysis rate constant of ciprofloxacin in a kaolinite suspension was also observed, and it was an order of magnitude smaller than that of the direct photodegradation (0.035 min) in water. The results indicate that ciprofloxacin is likely more stable when it is adsorbed on kaolinite and that the half-lives of ciprofloxacin in kaolinite and a kaolinite suspension are 2-25 times longer than that in deionized water (20 min) under simulated sunlight. Direct photolysis is proposed to be the main photodegradation mechanism for ciprofloxacin in kaolinite, and the cleavage of a piperazine ring is the main degradation pathway. However, the interaction between ciprofloxacin and kaolinite reduces the direct photolysis and leads to a higher light stability. In association with the reduction in photolysis, the yields of norfloxacin and defluorinated byproduct decreased significantly. Consequently, the interaction increases the persistence of ciprofloxacin and thus the ecological risk to the environment. [ABSTRACT FROM AUTHOR]

In order to simulate different altitudes in the atmosphere of Titan, we investigated using infrared spectrometry and mass spectrometry the photochemistry of ethyl cyanide (CH 3 CH 2 CN) ices at different temperatures. Heating experiments of the solid phase until complete desorption showed up three phase transitions with a first one appearing to be approximately at the temperature of Titan's surface (94 K), measured by the Huygens probe. Ethyl cyanide, whose presence has been suggested in solid phase in Titan, can be considered as another nitrile for photochemical models of the Titan atmosphere after our first study (Toumi et al., 2016) concerning vinyl cyanide (CH 2 CHCN). The desorption energy of ethyl cyanide has been calculated to be 36.75 ( ± 0.55) kJ mol − 1 using IRTF and mass spectroscopical techniques. High energetic photolysis ( λ > 120 nm) have been performed and we identified ethyl isocyanide, vinyl cyanide, cyanoacetylene, ethylene, acetylene, cyanhydric acid and a methylketenimine form as photoproducts from ethyl cyanide. The branching ratios of the primary products were determined at characteristic temperatures of Titan thanks to the value of the ν CN stretching band strength of ethyl cyanide that has been calculated to be 4.12 × 10 −18  cm molecule − 1 . We also report here for the first time the values of the photodissociation cross sections of C 2 H 5 CN for different temperatures. [ABSTRACT FROM AUTHOR]

A roadmap for the selection of a pharmaceutical salt form for a development candidate is presented. The free base of the candidate did not have sufficient chemical stability for development. The initially selected salt form turned out to be undevelopable because it was unstable during scale-up synthesis and storage. The rationale for the new solid form screening and the criteria for selection are discussed. Before the final selection, the pH solubility profiles of the 2 new salts, a benzoate and a besylate, were compared. Atypical solubility behavior was observed for the benzoate salt in hydrochloric acid with and without normal saline. A scheme is proposed illustrating how the p K as of the counterion and active pharmaceutical ingredient, the medium composition, and final pH affect the solubility and solution equilibria of the 2 selected salt forms. This scheme also includes the equilibria between solution and solid phases in different pH ranges. The pharmaceutical importance of this research is that it sheds light on how the acidity of the counterion can affect the solubility of the selected salt form in the gastric environment. With a well-designed formulation strategy, this property potentially can be translated to optimal biopharmaceutical performance of the drug product. [ABSTRACT FROM AUTHOR]

An approximate solution is presented for the prediction of air entrapment during tableting. Assuming weak coupling of the deformation of the solid phase, the flow of interstitial air and a set of reasonable additional geometric assumptions, the general problem is reduced to 1 dimension. Experimental values of air permeability through tablet specimens of commonly used pharmaceutical excipients were obtained using a 3D printed test cell outfitted to a powder rheometer. Using these values, combined with a numerical solution of the governing partial differential equation, parametric studies are presented that demonstrate the importance of permeability, compaction speed, tablet size, and punch-die tolerance on air entrapment. In addition, a first-order approximation of the role of entrapped air on the measured radial tensile strength of formed tablets is presented. [ABSTRACT FROM AUTHOR]

A novel derivatization method for gas chromatography/mass spectrometry (GC/MS)-based metabolomics was developed, based on solid-phase analytical derivatization (SPAD) with methoximation followed by trimethylsilylation. This SPAD method realized derivatization on solid phases combining strong anion exchange with strong cation exchange. To omit a sample condensation process, GC/MS injection was performed using a large-volume injection mode. This mode uses a stomach-shaped insert, and enables a large quantity of sample to be vaporized and introduced into the GC/MS system. In the present study, several parameters were investigated for each SPAD step. The optimal derivatization conditions were determined to be 3-min-methoximation with 5 μL of >5% methoxyamine solution, and 10-min-trimethylsilylation with 25 μL of N -methyl- N -trimethylsilyl-trifluoroacetamide (MSTFA). Derivatized analytes were effectively eluted with 25 μL of n -hexane. The influences of coexisting substances were also investigated. Coexisting saccharides did not significantly affect the derivatization of analytes. Moreover, saccharides were efficiently washed out using 80% (v/v) acetonitrile in water. The influences of coexisting sodium chloride were negated by dilution of the sample solution with water. The developed method enables the derivatization of both anionic and cationic metabolites, and high-throughput sample preparation. The coverage of detectable metabolites for the developed method was similar to that of the conventional method. This is the first report of a SPAD-based human plasma metabolome analysis protocol. [ABSTRACT FROM AUTHOR]

A new colorimetric and fluorometric chemosensor was developed and synthesized that showed both color and fluorescence changes upon the addition of cyanide ion in 80% aq. DMSO solution and in the solid phase. The chemosensor showed a selective and sensitive response to cyanide ion over other common anions such as F − , Cl − , Br − , I − , H 2 PO 4 − , NO 3 − and AcO − . The binding stoichiometry between the receptor and cyanide ions was found to be 1:2 ratio, and the detection of cyanide occurred through deprotonation coupled with intermolecular proton transfer, which was confirmed by a 1 H NMR titration experiment. The detection limit was calculated to be 7.49 nM, which is much lower than the permissible limit set by WHO (1.9 μM). [ABSTRACT FROM AUTHOR]

By the method of solid-phase welding, we join a package of oxide-dispersion-strengthened (ODS) steel and 08Kh18N10Т stainless steel. We study the interface of the joint of specimens by using metallography, ultrasound, mechanical tensile tests, and the tests for the quality of joints of the layers. It is shown that the proposed method enables one to get high-quality interfaces of the joints without breaks and discontinuities and, in this case, all properties of the ODS steel, such as fine grains and the density of distribution of nanoparticles remain invariable. [ABSTRACT FROM AUTHOR]

The goal of this article was oriented to prepare stable polystyrene coated tubes for direct radioimmunoassay (RIA) of human cortisol. Coating process was performed using rabbit polyclonal antisera specific for cortisol. The stability study showed that these tubes could be stored for up to one year at 4°C without any appreciable reduction in their binding. Labeling of cortisol was carried out using chloramin-T method and the 125I-cortisol tracer was purified using HPLC column. Preparation of polyclonal antibodies (anti-cortisol) was carried out in host rabbit animals against cortisol-21-hemisuccinate:Bovine serum albumin conjugate. The statistical analysis revealed good correlations between the results from the present study and the commercial IZOTOP RIA kit. The local may be extremely helpful in diagnosis and proper management of adrenal cortex disorders. [ABSTRACT FROM AUTHOR]

Heteroatom-doped carbon nanoparticles (CNPs) have attracted considerable attention due to an effective improvement in their intrinsic properties. Here, a facile and simple synthesis of nitrogen, boron co-doped carbon nanoparticles (NB-CNPs) from a sole precursor, 3-aminophenylboronic acid, was performed via a one-step solid-phase approach. Because of the presence of boronic acid, NB-CNPs can be used directly as a fluorescent probe for glucose. Based on a boronic acid-triggered specific reaction, we developed a simple NB-CNP probe without surface modification for the detection of glucose. When glucose was introduced, the fluorescence of NB-CNPs was suppressed through a surface-quenching states mechanism. Obvious fluorescence quenching allowed the highly sensitive determination of glucose with a limit of detection of 1.8 μM. Moreover, the proposed method has been successfully used to detect glucose in urine from people with diabetes, suggesting potential application in sensing glucose. [ABSTRACT FROM AUTHOR]

Prevalent polymorphism and complicated phase behavior of active pharmaceutical ingredients (APIs) often result in remarkable differences in the respective biochemical and physical API properties. Consequently, API form characterization and quantification play a central role in the pharmaceutical industry from early drug development to manufacturing. Here we present a novel and proficient quantification protocol for solid mixtures (qSRC) based on the measurement and mathematical fitting of T 1 nuclear magnetic resonance (NMR) saturation recovery curves collected on a bench top time-domain NMR instrument. The saturation recovery curves of the relevant pure components are used as fingerprints. Employing a bench top NMR instrument possesses clear benefits. These instruments exhibit a small footprint, do not present any special requirements on lab space, and required sample handling is simple and fast. The qSRC analysis can easily be conducted in a conventional laboratory setting as well as in an industrial production environment, making it a versatile tool with the potential for widespread application. The accuracy and efficiency of the qSRC method is illustrated using 1 H and 19 F T 1 data of selected pharmaceutical model compounds, as well as utilizing 1 H T 1 data of an actual binary API anhydrous polymorph system of a Merck & Co., Inc. compound formerly developed as a hepatitis C virus drug. [ABSTRACT FROM AUTHOR]

The need for characterization of thermophysical properties of steel was addressed in the FFG-Bridge Project 810999 in cooperation with our partner from industry, Böhler Edelstahl GmbH & Co KG. To optimize numerical simulations of production processes such as plastic deformation or remelting, additional and more accurate thermophysical property data were necessary for the group of steels under investigation. With the fast ohmic pulse heating circuit system and a commercial high-temperature Differential Scanning Calorimeter at Graz University of Technology, we were able to measure the temperature-dependent specific electrical resistivity and specific enthalpy for a set of five high alloyed steels: E105, M314, M315, P800, and V320 from room temperature up into the liquid phase. The mechanical properties of those steels make sample preparation an additional challenge. The described experimental approach typically uses electrically conducting wire-shaped specimen with a melting point high enough for the implemented pyrometric temperature measurement. The samples investigated here are too brittle to be drawn as wires and could only be cut into rectangular specimen by Electrical Discharge Machining. Even for those samples all electrical signals and the temperature signal can be recorded with proper alignment of the pyrometer. For each material under investigation, a set of data including chemical composition, solidus and liquidus temperature, enthalpy, electrical resistivity, and thermal diffusivity as a function of temperature will be reported. [ABSTRACT FROM AUTHOR]

The use of a continuously operated oscillatory flow baffled crystallizer (COBC) has been promoted as a promising alternative crystallizer design for continuous crystallization because of the claim, based on dispersion of liquid, that plug flow can be achieved. Plug flow can lead to uniformity in product quality, if good control over nucleation and the growth of crystals is also achieved. In this study a residence time distribution (RTD) analysis was made for both homogeneous (methylene blue-water) and heterogeneous tracer system (melamine-water). In literature it is proposed, on the basis of homogeneous tracer experiments only, that the velocity ratio Ψ (the ratio between the oscillatory velocity and the superficial velocity of the imposed flow) is sufficient to identify optimal operating conditions for plug flow in COBC. Multiple combinations of amplitude and frequency result in the desired Ψ value. Our results show that operating at high amplitudes increases dispersion, reducing the plug flow like mixing. Thus Ψ alone is not sufficient for optimizing the mixing. Our study for the first time compares dispersion of homogenous and heterogeneous tracer in the commercially available DN15 system, addressing the knowledge gap in handling solids in COBC. Comparable responses were obtained with both the tracer systems for changes in the oscillatory flow variables. Operation at relative low amplitudes was optimal to obtain plug flow like behavior, even with 10% (w/w) slurry with no problems of the particles settling. The optimal operating condition for minimal dispersion was clearly different for the homogenous and the heterogeneous system. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the solubility of iron (Fe) and identify the solid phases responsible for controlling its solubility in these soils by using Baker soil test (BST) computer program. The results indicated that the ferric ion (Fe3+) activity in all the soils, except the acidic ones, nearly approached the theoretical solubility line of known minerals, namely soil-Fe, amorphous-Fe, maghemite, and lepidocrocite. Solubility of Fe in acid soils of Ranchi (soil 3) and Cooch-Behar (soil 6) did not match the theoretical solubility lines of any of the known minerals. The acidic soils of Ranchi and Cooch-Behar were sufficient for Fe with respect to both quantity and intensity factor based on BST rating, while alkaline (soil 1) and calcareous (soil 5) were sufficient in reserve Fe; deficiency of iron still could be suspected because of high pH. These findings elucidate the role of solid phase controlling iron solubility in soil solution of degraded soils. [ABSTRACT FROM PUBLISHER]

Separation of suspensions in a batch-action centrifuge was investigated as an aggregate of phenomena of sedimentation of the solid phase, formation of sediment and filtration of the clarified liquid. Analysis was performed to determine the time-dependence of the results of centrifugal separation of a liquid system on the concentration of the solid, dispersion of the processed product, filter base, geometrical and physicomechanical parameters of the process. Using a particular example, separation efficiency of suspensions was estimated numerically from the processing times of the centrifugal equipment. [ABSTRACT FROM AUTHOR]

Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts. [ABSTRACT FROM AUTHOR]

The use of pre-prepared diaminodiacids has been established as an effective approach for the chemical synthesis of peptide disulfide bond mimics. A technical problem often encountered in the implementation of the diaminodiacids strategy is the use of heavy metal reagents to remove the side-chain protecting groups. In the present work, we reported the development of diaminodiacid that carry 4-(N-[1-(4,4-dimethyl-2,6-dioxocyclo-hexylidene)-3-methylbutyl]amino)benzyl (Dmab) and 1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)-3-methylbutyl (ivDde) protecting groups. This pair of protecting groups can be readily removed by mild hydrazinolysis during the solid-phase synthesis on resin. We demonstrated the use of Dmab/ivDde protected diaminodiacids in the successful synthesis of a disulfide surrogate of oxytocin. [ABSTRACT FROM AUTHOR]

The effects of propellant type, cosolvent content, and air humidity on the morphology and solid phase of the particles produced from solution pressurized metered dose inhalers containing the corticosteroid beclomethasone dipropionate were investigated. The active ingredient was dissolved in the HFA propellants 134a and 227ea with varying levels of the cosolvent ethanol and filled into pressurized metered dose inhalers. Inhalers were actuated into an evaporation chamber under controlled temperature and humidity conditions and sampled using a single nozzle, single stage inertial impactor. Particle morphology was assessed qualitatively using field emission scanning electron microscopy and focused ion beam-helium ion microscopy. Drug solid phase was assessed using Raman microscopy. The relative humidity of the air during inhaler actuation was found to have a strong effect on the particle morphology, with solid spheroidal particles produced in dry air and highly porous particles produced at higher humidity levels. Air humidification was found to have no effect on the solid phase of the drug particles, which was predominantly amorphous for all tested formulations. A critical level of air relative humidity was required to generate porous particles for each tested formulation. This critical relative humidity was found to depend on the amount of ethanol used in the inhaler, but not on the type of propellant utilized. The results indicate that under the right circumstances water vapor saturation followed by nucleated water condensation or ice deposition occurs during particle formation from evaporating propellant-cosolvent-BDP droplets. This finding reveals the importance of condensed water or ice as a templating agent for porosity when particle formation occurs at saturated conditions, with possible implications on the pharmacokinetics of solution pMDIs and potential applications in particle engineering for drug delivery. [ABSTRACT FROM AUTHOR]

The key quantitative characteristics of the theory of buffer action for polycomponent mono- and two-phase systems have been derived. It is shown, that the buffer properties in relation to the solid phase components are amplified with an increase of solubility due to protolytic or complex formation equilibria in saturated solutions.

Lanthanide(III) ions can accelerate the hydrolysis of phosphomonoesters and phosphodiesters in neutral aqueous solution. In this paper, lanthanide-mediated dephosphorylation has been applied in aqueous media as an orthogonal cleavage condition that can be employed in conventional solid phase peptide synthesis (SPPS). A phosphorylated polymeric support for SPPS was developed using Boc chemistry. The cleavage of resin-bound phosphates was investigated with the addition of Eu(III), Yb(III), acid or base, a mixture of solvents or different temperatures. To demonstrate the utility of this approach for SPPS, a peptide sequence was synthesized on a phosphorylated polymeric support and quantitatively cleaved with lanthanide ions in neutral aqueous media. The protecting groups for side chains were retained during peptide cleavage using lanthanide ions. This new methodology provides a mild orthogonal cleavage condition of phosphoester as a linker during SPPS.

An approach has been developed to determine the equilibrium model in heterogeneous aqueous systems containing a mixture of solid phases from the initial composition of the heterogeneous mixture and the equilibrium values of the pH. This approach allows to significantly reduce the quantity of measured data, properly for solubility measurements. By using the new deduced equations it is possible to determine the solubility products of precipitates on the basis of the known composition of initial mixtures and pH values of saturated solutions avoiding some difficult experimental solubility measurements. The derived relations are useful for solving both direct and indirect equilibrium problems.

It is shown that by arsenic diffusion alloying of silicon plates in conditions of deaerated quartz ampoule the most effective is the use of a compound source in the form of crystal arsenic and silicon powder of boron-implanted silicon grade with base impurity (boron) concentration not less than the concentration of base impurity in alloyed silicon plates. The work defines experimental values of surface concentration, proper and effective diffusion coefficients that fit diffision conditions of As inside ampoule for 2 h at temperature 1423 K and pressure of As steams of 2·105 Pa. The received results are of interest in designing and producing of low-voltage (less than 7 V) suppressors on the silicon base.

• This method enables to predict the apparition of pure solid(s) in fluid mixtures. • Solid-fluid equilibria are solved using a Gibbs energy minimization technique. • As a proof of effectiveness, complex binary system phase diagrams were calculated. • This method can be used to build complex phase envelopes of multicomponent system. The possibility of phase equilibria involving solid phases is often ignored in the popular phase-equilibrium calculation tools although one possible way of accounting for the potential presence of solid phases is to assume that solids precipitate as pure compounds. Using this assumption, multicomponent systems may contain a number of pure solid phases equal to the number of components. Predicting the correct number of coexisting solid and fluid phases then becomes a challenge. In this work, the Gibbs energy minimization technique is used. The cases of fluid (vapor or liquid) + solid(s) phase equilibrium and multi-fluid + solid(s) (i.e., 1 or 2 liquid phases and/or vapor phase + solid phases) equilibrium are both described. The effectiveness of the proposed approach is demonstrated by applications to several examples. A Python code is provided to illustrate the proposed algorithms. [ABSTRACT FROM AUTHOR]

Background: Glycans play critical roles in a number of biological activities. Two common types of glycans, N-linked and O-linked, have been extensively analyzed in the last decades. N-glycans are typically released from glycoproteins by enzymes, while O-glycans are released from glycoproteins by chemical methods. It is important to identify and quantify both N- and O-linked glycans of glycoproteins to determine the changes of glycans. Methods: The effort has been dedicated to study glycans from ovarian cancer cells treated with O-linked glycosylation inhibitor qualitatively and quantitatively. We used a solid-phase chemoenzymatic approach to systematically identify and quantify N-glycans and O-glycans in the ovarian cancer cells. It consists of three steps: (1) immobilization of proteins from cells and derivatization of glycans to protect sialic acids; (2) release of N-glycans by PNGase F and quantification of N-glycans by isobaric tags; (3) release and quantification of O-glycans by ß-elimination in the presence of 1-phenyl-3-methyl-5-pyrazolone (PMP). Results: We used ovarian cancer cell lines to study effect of O-linked glycosylation inhibitor on protein glycosylation. Results suggested that the inhibition of O-linked glycosylation reduced the levels of O-glycans. Interestingly, it appeared to increase N-glycan level in a lower dose of the O-linked glycosylation inhibitor. The sequential release and analyses of N-linked and O-linked glycans using chemoenzymatic approach are a platform for studying N-glycans and O-glycans in complex biological samples. Conclusion: The solid-phase chemoenzymatic method was used to analyze both N-linked and O-linked glycans sequentially released from the ovarian cancer cells. The biological studies on O-linked glycosylation inhibition indicate the effects of O-glycosylation inhibition to glycan changes in both O-linked and N-linked glycan expression. [ABSTRACT FROM AUTHOR]

Solubility of metal in contaminated soils is a key factor which controls the phytoavailability and toxic effects of metals on soil environment. The chemical equilibria of metal ions between soil solution and solid phases govern the solubility of metals in soil. Hence, an attempt was made to identify the probable solid phases (minerals), which govern the solubility of Zn2+and Cd2+in zinc smelter effluent-irrigated soils. Estimation of free ion activities of Zn2+(pZn2+) and Cd2+(pCd2+) by Baker soil test indicated that metal ion activities were higher in smelter effluent-irrigated soils as compared to that in tubewell water-irrigated soils. Identification of solid phases further reveals that free ion activity of Zn2+and Cd2+in soil highly contaminated with Zn and Cd due to long-term irrigation with zinc smelter effluent is limited by the solubility of willemite (Zn2SiO4) in equilibrium with quartz and octavite (CdCO3), respectively. However, in case of tubewell water-irrigated soil, franklinite (ZnFe2O4) in equilibrium with soil-Fe and exchangeable Cd are likely to govern the activity of Zn2+and Cd2+in soil solution, respectively. Formation of highly soluble minerals namely, willemite and octavite indicates the potential ecological risk of Zn and Cd, respectively in smelter effluent irrigated soil. [ABSTRACT FROM PUBLISHER]

Adsorption of As (V) by poly ( N -octyl-4-vinylpyridinium) bromide (P4VPyC8), used as solid phase, was studied. Determination of As (V) was carried out by direct measurement of the fluorescence intensity on the solid phase. Adsorption variables were optimized for obtaining optimum values of pH and agitation time, where pH 9.0 and 60 min were established as optimum values. The adsorption of arsenic (V) was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. It was found that the fluorescence of the solid phase increases as the concentration of arsenic increases. Linearity was observed in the concentration range 6.80 to 90.0 μg L − 1 . The detection limit for determination of As (V) by this method was 2.24 μg L − 1 and the relative standard deviation (RSD) was 1.72%. The amount of retained As (V) was 0.154 mg/g of solid phase. The determination of As (V) in a sample of tap water by this method was well compared with the value reported by an external certified laboratory. Therefore, the method of analysis proposed here could be used as a screening methodology for monitoring the fulfillment of the norm for arsenic concentration in tap water. [ABSTRACT FROM AUTHOR]

Method of automatic control of ore suspension solid phase parameters, which comprise the forming of gamma rays and low-frequency volume ultrasonic waves in the ore material suspension flow, measurement of the intensity of gamma radiation and low frequency volume ultrasonic waves, is presented. [ABSTRACT FROM AUTHOR]

ᅟThe term speciation is used for over 30 years, with different meanings. In the early 2000s, a reference definition was proposed. The elemental distribution is discussed only with respect to molecular structures. Polytatomic entities such as amorphous or crystalline structures, dispersed in a liquid or gas, or in the solid phase, are not taken into account. The distribution of the element, both at the interfaces and in the solids, is not yet considered. This editorial discusses the limitations of this definition and its consequences. The different terminologies proposed from the reference definition are also discussed. Given all these considerations, it is proposed that speciation is considered as a description of the physical and chemical characteristics of an element. This description should be given from the atomic scale of this element to the scale of the surrounding medium, in the continuum of size, from the dissolved or gaseous phase to the solid phases. [ABSTRACT FROM AUTHOR]

Sialic acids usually locate at the terminal of many glycan structures in either α(2,3) or α(2,6) linkage, playing different roles in various biological and pathological processes. Several linkage specific carboxyl derivatization methods have been reported to discriminate between α(2,3) and α(2,6)-linked sialic acids by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Among them, ethyl esterification was recently reported to achieve linkage specific derivatization between α(2,3) and α(2,6)-linked sialic acids with good selectivity. However, the method suffered from the instability of the generated lactones and byproducts of the derivatives. To overcome these shortcomings, a solid-phase two step derivatization method was introduced to convert the α(2,6)-linked sialic acid into ethyl esters and the α(2,3)-inked counterparts into N-methyl amides, respectively. Under the optimized derivatization conditions, our method was able to achieve accurate relative quantification of N-glycan as well as their corresponding sialylated linkage types, superior to the ethyl esterification method. The solid phase derivatization strategy was further applied to investigate N-glycans from biosimilar antibody drug and human serum from patients and healthy volunteers. This method has the potential to be used in the biomarker discovery and pharmaceutical industry. [ABSTRACT FROM AUTHOR]

The method for determining of pulp solid phase particle size distribution and density is proposed. The measurement of pulp solid phase particles concentration (low-frequency ultrasound waves) and their density (gamma radiation) during controlled action of high-energy ultrasound radiation pressure on the trajectory of their movement in pulp flow is carried out. [ABSTRACT FROM AUTHOR]

The article presents the results of numerical modeling of the solidification process. We used one of the enthalpy formulations of solidification. In particular, we focused on comparing the results of calculations for various methods of the effective thermal capacity approximation used in the apparent heat capacity formulation of solidification. We have shown that the choice of one of four tested methods of approximation does not significantly affect the results and duration of the numerical simulations. Differences in the resulting temperature did not exceed a few degrees. All numerical simulations were executed on software with our solidification module. [ABSTRACT FROM AUTHOR]

The method of measurement of pulp solid phase concentration and particle size distribution based on the high energy ultrasound radiation pressure influence is proposed. [ABSTRACT FROM AUTHOR]

The solubilities of zirconium hydroxide and oxide after aging at 278, 313, and 333 K were measured at 278, 298, 313, and 333 K in the pHc range of 0.3-7 in a 0.5 M ionic strength solution of NaClO4 and HClO4. Size distributions of the colloidal species were investigated by ultrafiltration using membranes with different pore sizes, and the solid phases were examined by X-ray diffraction. The apparent solubility of zirconium amorphous hydroxide (Zr(OH)4(am)), prepared by the oversaturation method, decreased with increasing aging temperature ( Ta), and the size distributions obtained after aging at elevated temperatures indicated the growth of the colloidal species. We, therefore, suggested that agglomeration of the colloidal species and dehydration and crystallization of Zr(OH)4(am) as the solubility-limiting solid phase occurred over the course of aging at elevated temperatures. For sample solutions of the crystalline oxide (ZrO2(cr)), the aging temperature had no significant effect on the solubility, but the solubility data at lower temperatures were found to be slightly higher than those at higher temperatures, implying a small fraction of the amorphous components. In the analysis of different solid phases (Zr(OH)4(s, Ta), Ta = 278, 313, and 333 K) depending on the aging temperatures, the solubility products ( Ksp, Ta) were determined at different measurement temperatures, and the enthalpy change ( Δr H○) for Zr4++ 4OH - ↔ Zr(OH)4(s, Ta) was calculated using the van't Hoff equation. The solid-phase-transformation process at elevated temperatures was also analyzed based on the obtained Ksp, Ta and Δr H○ values. [ABSTRACT FROM AUTHOR]