Binding Agents Research Articles

Influence of the Al2O3 Solid Phase on the Kinetics of Binding Ceramic Moulds

Abstract The investigation results of the kinetics of binding ceramic moulds, in dependence on the solid phase content in the liquid ceramic slurries being 67, 68 and 69% - respectively, made on the basis of the aqueous binding agents Ludox AM and SK. The ultrasonic method was used for assessing the kinetics of strengthening of the multilayer ceramic mould. Due to this method, it is possible to determine the ceramic mould strength at individual stages of its production. Currently self-supporting moulds, which must have the relevant strength during pouring with liquid metal, are mainly produced. A few various factors influence this mould strength. One of them is the ceramic slurry viscosity, which influences a thickness of individual layers deposited on the wax model in the investment casting technology. Depositing of layers causes increasing the total mould thickness. Therefore, it is important to determine the drying time of each deposited layer in order to prevent the mould cracking due to insufficient drying of layers and thus the weakening of the multilayer mould structure.

Deuterated 18F-9-O-hexadeutero-3-fluoropropoxyl-(+)-dihydrotetrabenazine (D6-FP-(+)-DTBZ): A vesicular monoamine transporter 2 (VMAT2) imaging agent

IntroductionVesicular monoamine transporters 2 (VMAT2) in the brain serve as transporter for packaging monoamine in vesicles for normal CNS neurotransmission. Several VMAT2 imaging agents, [11C]-(+)-DTBZ, dihydrotetrabenazine and [18F]FP-(+)-DTBZ (9-O-fluoropropyl-(+)-dihydro tetrabenazine, a.k.a. [18F]AV-133), are useful for studying the changes in brain function related to monoamine transmission by in vivo imaging. Deuterated analogs have been reported targeting VMAT2 binding sites. MethodsA novel deuterated [18F]9-O-hexaduterofluoropropyl-(+)-dihydrotetrabenazine, [18F]D6-FP-(+)-DTBZ, [18F]1, was prepared as a VMAT2 imaging agent. This 18F agent which targeted VMAT2 was evaluated by in vitro binding, in vivo biodistribution and microPET imaging studies in rodents. ResultsThe one step radiolabeling reaction led to the desired [18F]D6-FP-(+)-DTBZ, [18F]1, which showed excellent binding affinity to VMAT2 (Ki=0.32±0.07nM) comparable to that of FP-(+)-DTBZ (Ki=0.33±0.02nM) using [18F]FP-(+)-DTBZ and rat striatum membrane homogenates. In vivo biodistribution in normal rats showed that 1, exhibited excellent brain uptake and comparable high ratio of striatum to cerebellum (target/background) ratio at 1h after injection (ratio of 6.05±0.43 vs 5.66±0.72 for [18F]FP-(+)-DTBZ vs [18F]1, respectively). MicroPET imaging studies in rats further confirm that the striatum with high VMAT2 concentration was clearly delineated in normal rat brain after iv injection of [18F]1. We observed minor changes of metabolism in rat plasma between these two agents; however, the changes showed little effect on regional brain uptake and retention. ConclusionsThe results reported here lend support for using [18F]D6-FP-(+)-DTBZ, [18F]1, as in vivo PET imaging agent for VMAT2 binding in the brain.

The Influence of Polishing of a Composite Coating on Its Electrochemical Behavior in a Corrosive Medium

A composite anticorrosive coating based on an aluminum–chromium–phosphate binding agent (ACPB) and an aluminum filler has been studied using electrochemical methods. The influence of the factor of polishing of the surface on the protective properties of the coating has been shown. A mechanism for the protection of the coating has been proposed.

Recent Advances in Nucleic Acid Targeting Probes and Supramolecular Constructs Based on Pyrene-Modified Oligonucleotides.

In this review, we summarize the recent advances in the use of pyrene-modified oligonucleotides as a platform for functional nucleic acid-based constructs. Pyrene is of special interest for the development of nucleic acid-based tools due to its unique fluorescent properties (sensitivity of fluorescence to the microenvironment, ability to form excimers and exciplexes, long fluorescence lifetime, high quantum yield), ability to intercalate into the nucleic acid duplex, to act as a π-π-stacking (including anchoring) moiety, and others. These properties of pyrene have been used to construct novel sensitive fluorescent probes for the sequence-specific detection of nucleic acids and the discrimination of single nucleotide polymorphisms (SNPs), aptamer-based biosensors, agents for binding of double-stranded DNAs, and building blocks for supramolecular complexes. Special attention is paid to the influence of the design of pyrene-modified oligonucleotides on their properties, i.e., the structure-function relationships. The perspectives for the applications of pyrene-modified oligonucleotides in biomolecular studies, diagnostics, and nanotechnology are discussed.

Design, Synthesis, and Evaluation of Bis‐Benzothiazole Derivatives as DNA Minor Groove Binding Agents

A series of novel bis‐benzothiazole derivatives with head‐to‐head orientation were designed, synthesized, and evaluated for their anti‐proliferative activities on U937, HL60, and HeLa cells. A significant part of the targets exhibited considerable in vitro anticancer activity, and some of them were more potent than the reference 5‐FU. Molecular modeling, fluorescence, and viscosimetry studies revealed that these compounds could bind into the minor groove of DNA. Amongst them, the most active compound 7 with IC50 in a range of 6.76 to 8.67 μM against the tested three cell lines, which was 1.46–2.47 and 3.48–4.93 times more potent than 5‐FU and Hoechst 33258, respectively, warrant further investigations.

DGT Passive Sampling for Quantitative in Situ Measurements of Compounds from Household and Personal Care Products in Waters.

Widespread use of organic chemicals in household and personal care products (HPCPs) and their discharge into aquatic systems means reliable, robust techniques to monitor environmental concentrations are needed. The passive sampling approach of diffusive gradients in thin-films (DGT) is developed here and demonstrated to provide in situ quantitative and time-weighted average (TWA) measurement of these chemicals in waters. The novel technique is developed for HPCPs, including preservatives, antioxidants and disinfectants, by evaluating the performance of different binding agents. Ultrasonic extraction of binding gels in acetonitrile gave good and consistent recoveries for all test chemicals. Uptake by DGT with HLB (hydrophilic-lipophilic-balanced) as the binding agent was relatively independent of pH (3.5-9.5), ionic strength (0.001-0.1 M) and dissolved organic matter (0-20 mg L-1), making it suitable for applications across a wide range of environments. Deployment time and diffusion layer thickness dependence experiments confirmed DGT accumulated chemicals masses are consistent with theoretical predictions. The technique was further tested and applied in the influent and effluent of a wastewater treatment plant. Results were compared with conventional grab-sampling and 24-h-composited samples from autosamplers. DGT provided TWA concentrations over up to 18 days deployment, with minimal effects from biofouling or the diffusive boundary layer. The field application demonstrated advantages of the DGT technique: it gives in situ analyte preconcentration in a simple matrix, with more quantitative measurement of the HPCP analytes.

Lightweight Composite Cermets Obtained by Titanium-Plating

The hot-pressing method was used to produce reinforced composite cermets based on SiC, TiC, and TiB2. Titanium was used as the metal binding agent added during the mixing of the components. The density of the prepared materials was 1.5 – 2.0 lower than the density of sintered cermets with similar mechanical properties.

Fabrication of 3-methoxyphenol sensor based on Fe3O4 decorated carbon nanotube nanocomposites for environmental safety: Real sample analyses.

Iron oxide ornamented carbon nanotube nanocomposites (Fe3O4.CNT NCs) were prepared by a wet-chemical process in basic means. The optical, morphological, and structural characterizations of Fe3O4.CNT NCs were performed using FTIR, UV/Vis., FESEM, TEM; XEDS, XPS, and XRD respectively. Flat GCE had been fabricated with a thin-layer of NCs using a coating binding agent. It was performed for the chemical sensor development by a dependable I-V technique. Among all interfering analytes, 3-methoxyphenol (3-MP) was selective towards the fabricated sensor. Increased electrochemical performances for example elevated sensitivity, linear dynamic range (LDR) and continuing steadiness towards selective 3-MP had been observed with chemical sensor. The calibration graph found linear (R2 = 0.9340) in a wide range of 3-MP concentration (90.0 pM ~ 90.0 mM). The limit of detection and sensitivity were considered as 1.0 pM and 9×10−4 μAμM-1cm-2 respectively. The prepared of Fe3O4.CNT NCs by a wet-chemical progression is an interesting route for the development of hazardous phenolic sensor based on nanocomposite materials. It is also recommended that 3-MP sensor is exhibited a promising performances based on Fe3O4.CNT NCs by a facile I-V method for the significant applications of toxic chemicals for the safety of environmental and health-care fields.

1,4-Disubstituted-5-hydroxy-3-methylpyrazoles and some derived ring systems as cytotoxic and DNA binding agents. Synthesis, in vitro biological evaluation and in silico ADME study

Some novel polysubstituted pyrazoles, bipyrazoles and pyranopyrazoles, supported with various chemotherapeutically-active pharmacophores, were synthesized and biologically evaluated for their cytotoxic potential. Fifteen compounds (7–9, 12, 16, 17, 19, 21, 22, 26, 28, 30, 32, 33, and 34) exhibited variable degrees of cytotoxic activity against a panel of three cancer cell lines, among which the analogs 16, 17, 21, 26, and 34 showed a considerable broad spectrum cytotoxic potential, with special effectiveness against the colon HT29 and breast MCF7 cancer cell lines. In particular, compounds 16, 17, and 26 displayed double the activity of doxorubicin against colon carcinoma HT29 cell line, while the pyranopyrazole analog 34 was nearly equiactive with the reference cytotoxic agent. Meanwhile, the analogs 16 and 17 were nearly equipotent to doxorubicin against breast MCF7 cell line. DNA-binding activities of the most active compounds were in agreement with the obtained anticancer activity, where compounds 16, 17, 26, and 34 displayed the highest affinity. In silico calculations of molecular properties revealed that most of the active compounds comply with Lipinski’s RO5 and Veber’s criteria for good bioavailability suggesting good drug-likeness properties upon oral administration.

Preparation of nanostructured Cu(OH)2 and CuO electrocatalysts for water oxidation by electrophoresis deposition

Abstract

Effect of Green Coffee Bean Extract on the Lipid Oxidative Stability and Storage Quality of Restructured Mutton Blocks Containing Colocasia esculenta, a Novel Binding Agent

The study was undertaken to explore the possibility of utilization of Colocasia esculenta as a novel binding agent for restructured meat products. Restructured mutton blocks were used as a model and prepared by incorporating different levels of C. esculenta, viz. 1, 3 and 5%, and optimized at 3% level on the basis of various quality parameters. The binding agent proposed here suggests a high improvement in binding in addition to various functional properties. Restructured mutton blocks containing optimum level of C. esculenta (3%) were further treated with green coffee bean extract (GCB) as a novel natural preservative and assessed for various lipid oxidative stability and storage quality parameters under refrigerated conditions (4 ± 1 °C). Products containing GCB extract (1%) showed significantly (P < 0.05) higher acceptability with significantly (P < 0.05) lower TBARS (Thiobarbituric acid reacting substances) (mg malondialdehyde/kg) and FFA free fatty acid (% oleic acid) values. The restructured mutton blocks containing GCB extract (1%) also showed significantly (P < 0.05) lower values for various microbiological characteristics like total plate count (log cfu/g) and psychrophilic count (log cfu/g). The results showed herein indicate a promising industrial application of C. esculenta (3%) as a binding agent for restructured meat products and green coffee bean extract (1%) as a novel natural preservative for improved lipid oxidative stability and storage quality.

A new physics-based model for equilibrium saturation determination in binder jetting additive manufacturing process

Abstract In binder jetting additive manufacturing (BJ-AM) process, the features are created through the interaction between droplets of the liquid binding agent and the layered powder bed. The amount of binder, which is termed binder saturation, depends strongly on the liquid binder and powder bed interaction including the spreading (i.e. lateral migration) and penetration (vertical migration) of the binder in powder bed, and is of crucial importance for determining the accuracy and strength of the printed parts. In the present study, a new physics-based model is developed to predict the optimal saturation levels for the green part printing, which is realized via capillary pressure estimation that is based on the binder and powder bed interactions in the equilibrium state. The proposed model was evaluated by both the Ti-6Al-4V and 420 stainless steel powders that exhibit different powder characteristics and packing densities. In order to estimate the equilibrium saturation using the proposed model, the physical characteristics such as average contact angle between the binder and powder material, specific surface area of powder particles, saturation and capillary pressure characterization curve were determined. Features with various degrees of dimensions (1-D, 2-D, 3-D) were printed out using M-Lab ExOne printer for determining the equilibrium saturation. Good agreement was observed between the theoretical predictions and experimentally measured saturation levels for the Ti-6Al-4V powder. On the other hand, the model underestimated the optimal saturation level for the 420 stainless steel powder, which was likely caused by the micro-surface areas from powder particle surface that do not contribute to the binder-powder bed interactions.

Unique photoelectrocatalytic properties of a diphenyl-as-triazine-containing ruthenium(II) complex assembled on cadmium sulfide anode and cuprous oxide cathode towards ascorbate oxidation and oxygen reduction

A novel ruthenium(II) complex [Ru(dppt)2]2+ (dppt=bis[3-(1,10-phenanthroline-2-yl)-5,6-diphenyl-as-triazines) labeled as Ru(II) is assembled on CdS and Cu2O electrode to prepare Ru(II)/CdS photoanode and Ru(II)/Cu2O photocathode for the oxidation of ascorbate (AA) and the reduction of dioxygen (O2), respectively. The Ru(II) complex possesses two diphenyl-as-triazine-containing polypyridyl ligands to bind H2O (Kb=0.042Lmol−1) or AA (k=0.12molL−1s−1) through cooperative hydrogen bond, electrostatic attraction, and anion-π interactions, leading to an increase in the light-harvesting efficiency. The photoelectrocatalytic oxidation response of AA on Ru(II)/CdS electrode exhibits an enhancement upon increasing incubation time with AA in aqueous buffer solutions, in which the Ru(II) frame has ability to bind AA and simultaneously release dehydroascorbic acid (DHAA). Meanwhile, the Ru(II) complex on Cu2O photocathode acts as an appropriate binding agent to promote the photoelectrocatalytic reduction of O2 and H2O2. While employing Ru(II)/CdS anode and Ru(II)/Cu2O cathode to assemble an AA/O2 fuel cell irradiated with visible light of 0.18mWcm−2, the proposed cell shows Ru(II)-enhanced performances with open-circuit photovoltage of 0.626 V, short-circuit current density of 49.1μAcm−2 and maximum power density of 10.3μWcm−2 at 0.32V.

Phonological loop and central executive in hypothyroidism

In the present study, new series of thiazolopyrimidine derivatives was synthesized as purine analogs. The structures of the products were confirmed through spectroscopic techniques such as NMR and mass spectrometry. In addition, the synthesized compounds were evaluated as antitumor active agent through NCI screening protocol against 60 different cell lines under 9 different panels. Furthermore, DNA binding activity of the compounds was also evaluated. The results revealed that compound 35 proved to be the most active member of the tested series and it is promoted to the 5-dose testing where it gives GI50, TGI and LC50 values of 1.07, 6.61, 34.7 μM respectively. Furthermore, it also proved to have a good DNA binding activity with value that is comparable with that produced by doxorubicin which was used as positive standard. In addition, compound 27 was proved to be the most active DNA binding agent with binding affinity 28.38 ± 1.1. The pharmacokinetic properties were also calculated. Molecular docking studies suggested binding mode of compounds 27 and 35 to DNA minor groove via hydrogen bonding interaction. The anticancer activity of compounds 27 and 35 may be attributed to DNA binding.

Relationships between soil macroaggregation and humic carbon in a sandy loam soil following conservation tillage

Humic substances are recalcitrant and might act as persistent binding agents to form macroaggregates. The focus of this study is in investigating the contribution of humic carbon (HC) to soil aggregation in response to various tillage and residue managements. Arable soils following 8-year contrasting managements were collected to determine aggregate size distribution and stability and HC fractions including humic acid (HA) and fulvic acid (FA). The contribution of HC to aggregation was divided into three special effects including positive effect (PE), negative effect (NE), and combined effect (CE), and these effects were measured using aggregate fractionation techniques. As well as to promote structural stability, HC bounds predominantly with the silt + clay fraction and secondarily with microaggregates to form larger aggregates. The PE increased with increasing aggregate size, whereas the NE followed the opposite pattern. A positive CE was observed for large and small macroaggregates, whereas the CE for microaggregates and the silt + clay fraction was negative. Compared to continuous tillage, reduced- and no-tillage decreased the PE for large and small macroaggregates by 1.58–30.98% at the 0–20 cm depth, and straw returning also slightly decreased the corresponding PE relative to straw removing. By contrast, a significantly higher NE for small macroaggregates at the 0–10 cm depth while 6.33–81.11% decreases in CE for large and small macroaggregates at the 0–10 cm depth as well as for large macroaggregates at the 10–20 cm depth, were observed under reduced- and no-tillage. The extraction of HC significantly reduced the aggregate stability and reduced- and no-tillage effectively limited its decrease magnitude. Small macroaggregates and microaggregates made larger contributions to soil HC accumulation than did other fractions. An averagely increased contribution from large or small macroaggregates was observed under both reduced-/no-tillage and straw returning at the 0–20 cm depth. A significant and positive relationship was found between the mass proportion of macroaggregates and the HC accumulation in 0–20 cm soil. Large macroaggregates had significantly higher HA/FA ratios than small macroaggregates, and reduced- and no-tillage significantly increased these ratios both in large and in small macroaggregates. The CE for large or small macroaggregates was also significantly negatively correlated with their HA/FA ratios. Overall, the HC accumulation in soil is likely to play a key role in macroaggregation, but conservation tillage might decrease the contribution magnitude of HC to large or small macroaggregation through increasing the corresponding HA/FA ratios.

Antimicrobial 2-aminothiazolyl quinolones: what is their potential in the clinic?

Antimicrobial 2-aminothiazolyl quinolones: what is their potential in the clinic?

Sensitivity of docetaxel-resistant MCF-7 breast cancer cells to microtubule-destabilizing agents including vinca alkaloids and colchicine-site binding agents.

IntroductionOne of the main reasons for disease recurrence in the curative breast cancer treatment setting is the development of drug resistance. Microtubule targeted agents (MTAs) are among the most commonly used drugs for the treatment of breaset cancer and therefore overcoming taxane resistance is of primary clinical importance. Our group has previously demonstrated that the microtubule dynamics of docetaxel-resistant MCF-7TXT cells are insensitivity to docetaxel due to the distinct expression profiles of β-tubulin isotypes in addition to the high expression of p-glycoprotein (ABCB1). In the present investigation we examined whether taxane-resistant breast cancer cells are more sensitive to microtubule destabilizing agents including vinca alkaloids and colchicine-site binding agents (CSBAs) than the non-resistant cells.MethodsTwo isogenic MCF-7 breast cancer cell lines were selected for resistance to docetaxel (MCF-7TXT) and the wild type parental cell line (MCF-7CC) to examine if taxane-resistant breast cancer cells are sensitive to microtubule-destabilizing agents including vinca alkaloids and CSBAs. Cytotoxicity assays, immunoblotting, indirect immunofluorescence and live imaging were used to study drug resistance, apoptosis, mitotic arrest, microtubule formation, and microtubule dynamics.ResultsMCF-7TXT cells were demonstrated to be cross resistant to vinca alkaloids, but were more sensitive to treatment with colchicine compared to parental non-resistant MCF-7CC cells. Cytotoxicity assays indicated that the IC50 of MCF-7TXT cell to vinorelbine and vinblastine was more than 6 and 3 times higher, respectively, than that of MCF-7CC cells. By contrast, the IC50 of MCF-7TXT cell for colchincine was 4 times lower than that of MCF-7CC cells. Indirect immunofluorescence showed that all MTAs induced the disorganization of microtubules and the chromatin morphology and interestingly each with a unique pattern. In terms of microtubule and chromain morphology, MCF-7TXT cells were more resistant to vinorelbine and vinblastine, but more sensitive to colchicine compared to MCF-7CC cells. PARP cleavage assay further demonstrated that all of the MTAs induced apoptosis of the MCF-7 cells. However, again, MCF-7TXT cells were more resistant to vinorelbine and vinblastine, and more sensitive to colchicine compared to MCF-7CC cells. Live imaging demonstrated that the microtubule dynamics of MCF-7TXT cells were less sensitive to vinca alkaloids, and more sensitive to colchicine. MCF-7TXT cells were also noted to be more sensitive to other CSBAs including 2MeOE2, ABT-751 and phosphorylated combretastatin A-4 (CA-4P).ConclusionDocetaxel-resistant MCF-7TXT cells have demonstrated cross-resistance to vinca alkaloids, but appear to be more sensitive to CSBAs (colchicine, 2MeOE2, ABT-751 and CA-4P) compared to non-resistant MCF-7CC cells. Taken together these results suggest that CSBAs should be evaluated further in the treatment of taxane resistant breast cancer.

Aryl-Substituted Ruthenium(II) Complexes: A Strategy for Enhanced Photocleavage and Efficient DNA Binding.

Ruthenium polypyridine complexes have shown promise as agents for photodynamic therapy (PDT) and tools for molecular biology (chromophore-assisted light inactivation). To accomplish these tasks, it is important to have at least target selectivity and great reactive oxygen species (ROS) photogeneration: two properties that are not easily found in the same molecule. To prepare such new agents, we synthesized two new ruthenium complexes that combine an efficient DNA binding moiety (dppz ligand) together with naphthyl-modified (1) and anthracenyl-modified (2) bipyridine as a strong ROS generator bound to a ruthenium complex. The compounds were fully characterized and their photophysical and photochemical properties investigated. Compound 2 showed one of the highest quantum yields for singlet oxygen production ever reported (ΦΔ= 0.96), along with very high DNA binding (log Kb = 6.78). Such photochemical behavior could be ascribed to the lower triplet state involving the anthracenyl-modified bipyridine, which is associated with easier oxygen quenching. In addition, the compounds exhibited moderate selectivity toward G-quadruplex DNA and binding to the minor groove of DNA, most likely driven by the pendant ligands. Interestingly, they also showed DNA photocleavage activity even upon exposure to a yellow light-emitting diode (LED). Regarding their biological activity, the compounds exhibited an exciting antibacterial action, particularly against Gram-positive bacteria, which was enhanced upon blue LED irradiation. Altogether, these results showed that our strategy succeeded in producing light-triggered DNA binding agents with pharmacological and biotechnological potential.

A Functional Full-Scale Heat Exchanger Coated with Aluminum Fumarate Metal–Organic Framework for Adsorption Heat Transformation

Metal–organic frameworks represent a class of microporous adsorbents with high application potential for adsorption heat transformation. Here, we present a functional, full-scale heat exchanger coated with the microporous aluminum fumarate MOF Basolite A520 using a polysiloxane-based binding agent. The function of the heat exchanger was evaluated resulting in a gross cooling power of 2900 W (at the beginning of the adsorption cycle) or, respectively an average cooling power of 690 W (up to a limit of 90% equilibrium loading in 7 min) under the working conditions of a realistic adsorption chiller of 90 °C – 30 °C – 18 °C (temperature level of heat source, heat rejection/condenser, and evaporator).

Polymers as drugs—Advances in therapeutic applications of polymer binding agents

ABSTRACTPolymer drugs are those in which a polymer agent has a direct therapeutic effect on the body. A major investigated area of polymer drugs is their use as binding agents, or sequestrants, which can neutralize or remove undesired components from the body. By taking advantage of the unique properties of crosslinked, insoluble polymers, new polymer drugs continue to be developed for oral use, acting in the gastrointestinal tract and excreted in the feces. Soluble polymer binders may be administered by a variety of routes and act at diverse sites of therapeutic action. This article reviews the properties of polymer drugs, particularly sequestrants, with an emphasis on recent advances in polymer properties which may enhance the utility of this class of drugs. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3146–3157