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Solution liquid solid

Robert Zitterbart, Michael Krumrey, Oliver Seitz
The chemical synthesis of proteins typically involves the solid-phase peptide synthesis of unprotected peptide fragments that are stitched together in solution by native chemical ligation (NCL). The process is slow, and throughput is limited because of the need for repeated high performance liquid chromatography purification steps after both solid-phase peptide synthesis and NCL. With an aim to provide faster access to functional proteins and to accelerate the functional analysis of synthetic proteins by parallelization, we developed a method for the high performance liquid chromatography-free synthesis of proteins on the surface of microtiter plates...
April 21, 2017: Journal of Peptide Science: An Official Publication of the European Peptide Society
Mohsin J Qazi, Rinse W Liefferink, Simon J Schlegel, Ellen H G Backus, Daniel Bonn, Noushine Shahidzadeh
We study the influence of different surfactants on NaCl crystallization during evaporation of aqueous salt solutions. We found that at concentrations of sodium chloride close to saturation, only the cationic surfactant CTAB and the nonionic surfactant Tween 80 remain stable. For the nonionic surfactant, the high concentration of salt does not significantly change either the critical micellar concentration (CMC) or the surface tension at the CMC; for the cationic surfactant, the CMC is reduced by roughly 2 orders of magnitude upon adding the salt...
April 20, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
David Yan, Martin Z Bazant, P M Biesheuvel, Mary C Pugh, Francis P Dawson
Linear sweep and cyclic voltammetry techniques are important tools for electrochemists and have a variety of applications in engineering. Voltammetry has classically been treated with the Randles-Sevcik equation, which assumes an electroneutral supported electrolyte. In this paper, we provide a comprehensive mathematical theory of voltammetry in electrochemical cells with unsupported electrolytes and for other situations where diffuse charge effects play a role, and present analytical and simulated solutions of the time-dependent Poisson-Nernst-Planck equations with generalized Frumkin-Butler-Volmer boundary conditions for a 1:1 electrolyte and a simple reaction...
March 2017: Physical Review. E
Jianguo Jiang, Meng Yang, Yuchen Gao, Jiaming Wang, Dean Li, Tianran Li
Vanadium (V) contamination in soils is an increasing worldwide concern facing human health and environmental conservation. The fractionation of a metal influences its mobility and biological toxicity. We analyzed the fractionations of V and several other metals using the BCR three-step sequential extraction procedure. Among methods for removing metal contamination, soil washing is an effective permanent treatment. We conducted experiments to select the proper reagents and to optimize extraction conditions. Citric acid, tartaric acid, oxalic acid, and Na2EDTA all exhibited high removal rates of the extractable state of V...
March 31, 2017: Chemosphere
Alice R Mazzer, Luke A Clifton, Tatiana Perevozchikova, Paul D Butler, Christopher J Roberts, Daniel G Bracewell
Chromatography is a ubiquitous unit operation in the purification of biopharmaceuticals yet few studies have addressed the biophysical characterisation of proteins at the solution-resin interface. Chromatography and other adsorption and desorption processes have been shown to induce protein aggregation which is undesirable in biopharmaceutical products. In order to advance understanding of how adsorption processes might impact protein stability, neutron reflectivity was used to characterise the structure of adsorbed immunoglobulin G (IgG) on model surfaces...
April 1, 2017: Journal of Chromatography. A
T Gopinath, Sarah E D Nelson, Kailey J Soller, Gianluigi Veglia
Proteins exist in ensembles of conformational states that interconvert on various motional time scales. High-energy states of proteins, often referred to as conformationally excited states, are sparsely populated and have been found to play an essential role in many biological functions. However, detecting these states is quite difficult for conventional structural techniques. Recent progress in solution NMR spectroscopy made it possible to detect conformationally excited states in soluble proteins and characterize them at high resolution...
April 20, 2017: Journal of Physical Chemistry. B
Zhengyu Chen, Brian J Sahli, Mark J MacLachlan
New pyridylsalicylaldimine-based ligands with extended conjugation have been synthesized. The reaction of these ligands with K2PtCl4 yielded triangular Pt3 macrocycles rather than the anticipated Pt4 macrocycles. The macrocycles have been analyzed in solution by variable-temperature and variable-concentration (1)H NMR, NOESY, and DOSY spectroscopy studies. These investigations show that the macrocycles aggregate at room temperature in solution by an entropy-driven process. In the solid state, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and transmission electron microscopy studies show that the macrocycles aggregate into nanotubular structures...
April 12, 2017: Inorganic Chemistry
Qing Wang, Bin Qiu, Xianbo Chen, Bin Wang, Hui Zhang, Xiaoyuan Zhang
A novel mixed hemimicelles and magnetic dispersive solid-phase extraction method based on long-chain ionic liquids for the extraction of five fluorescent whitening agents was established. The factors influenced on extraction efficiency were investigated. Under the optimal conditions, namely, the pH of sample solution at 8.0, the concentration of long chain ionic liquid at 0.5 mmol/L, the amount of Fe3 O4 nanoparticle at 12 mg, extraction time at 10 min, pH 6.0 of methanol as eluent and the desorption time at 1 min, satisfactory results were obtained...
April 12, 2017: Journal of Separation Science
Andrew W Weber, Glen D O'Neil, Samuel P Kounaves
Solid contact polymeric ion-selective electrodes (SC-ISEs) have been fabricated using microporous carbon (µPC) as the ion-to-electron transducer, loaded with a liquid membrane cocktail containing both ionophore and additive dissolved in plasticizer. These SC-ISEs were characterized and shown to be suitable for analysis in aqueous environments at pressures of 100 bar. Potassium ISEs, prepared in this manner, showed excellent performance at both atmospheric and elevated pressures, as evaluated by their response slopes and potential stability...
April 12, 2017: Analytical Chemistry
Fatih Comert, Duy Nguyen, Marguerite Rushanan, Peker Milas, Amy Y Xu, Paul L Dubin
The polycation/anionic-nonionic mixed micelle, poly(diallyldimethylammonium chloride)-sodium dodecyl sulfate/Triton X-100 (PDADMAC-SDS/TX100), is a model polyelectrolyte-colloid system in that the micellar mole fraction of SDS (Y) controls the micelle surface charge density, thus modulating the polyelectrolyte-colloid interaction. The exquisite temperature dependence of this system provides an important additional variable, controlling both liquid-liquid (L-L) and liquid-solid (L-S) phase separation, both of which are driven by the entropy of small ion release...
April 19, 2017: Journal of Physical Chemistry. B
Honggao Xu, Kedong Tai, Tong Wei, Fang Yuan, Yanxiang Gao
BACKGROUND: Transformation of hot pepper residues to value-added products with concomitant benefits on environmental pollution would be a great value to the capsicum oleoresin manufacturers. Pectin, a soluble dietary fiber with multiple functions, from hot pepper residues was investigated in this study. RESULTS: The extraction of hot pepper pectin was first optimized using response surface methodology (RSM). The most efficient parameters for the maximum hot pepper pectin yield (14...
April 11, 2017: Journal of the Science of Food and Agriculture
Alexandra Perez-Anes, Anna Szarpak-Jankowska, Dorothée Jary, Rachel Auzely-Velty
Most procedures for detecting pathogens in liquid media require an initial concentration step. In this regard, carbohydrates have proven to be attractive affinity ligands for the solid-phase capture of bacteria that use lectins for adhesion to host cell membranes. However, the use of cyclodextrin-immobilized substrates to selectively trap bacteria has not been explored before. Here, using quartz-crystal microbalance with dissipation monitoring experiments, we demonstrate that functionalization of surfaces by β-cyclodextrin (β-CD) can not only allow for rapid and efficient capture of bacterial cells in liquid but also their facile elution with an aqueous solution of a selectively methylated β-CD derivative as a competitive molecule...
April 10, 2017: ACS Applied Materials & Interfaces
Shinya Taguchi, Hirofumi Kawazumi, Toshihiko Nagamura, Hirotaka Okabe, Naoki Matsuda
An automated solution exchange (SE) mechanism has been introduced to slab optical waveguide spectroscopy to estimate the protein immobilizing ability of a slab optical waveguide (SOWG) surface. In each SE process, SOWG spectral change in absorbance at peak position of cytochrome c (cyt.c) Soret band at 409 nm was observed to analyze the desorption ratio of cyt.c adsorbed on SOWG surface. Continuous SE processes for 100 times have successfully brought us a kind of master desorption curve of cyt.c, which was well fitted by a double exponential equation, indicating the existence of three kinds of adsorbed states, including weakly adsorbed, strongly adsorbed, and immobilized cyt...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Yuri S Djikaev, Eli Ruckenstein
Using the formalism of classical thermodynamics in the framework of the classical nucleation theory, we derive an expression for the reversible work W* of formation of a binary crystal nucleus in a liquid binary solution of non-stoichiometric composition (incongruent crystallization). Applied to the crystallization of aqueous nitric acid droplets, the new expression more adequately takes account of the effects of nitric acid vapor compared to the conventional expression of MacKenzie, Kulmala, Laaksonen, and Vesala (MKLV) [J...
April 7, 2017: Journal of Chemical Physics
Will J Backe
RATIONALE: New legislation in the state of Minnesota prohibits the sale of children's personal-care products (PCPs) that contain more than 500 ng/mg formaldehyde. Previous attempts to quantify formaldehyde in PCPs use nonspecific derivatization procedures that employ harsh reagents and/or nonspecific detection. Derivatization of formaldehyde by acetylacetone occurs under mild conditions and is specific for formaldehyde but it has not been investigated using high-performance liquid-chromatography tandem mass-spectrometry (HPLC-MS/MS)...
April 7, 2017: Rapid Communications in Mass Spectrometry: RCM
Amir Goshadrou, Mark Lefsrud
The present study investigated for the first time the efficacy of surfactant-assisted ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) pretreatment of beech wood waste for enhanced ethanol production. The ionic liquid (IL) pretreatment included wood dissolution at 120°C and 5% solid loading for 3h followed by regeneration using water as an anti-solvent. The substrate was initially presoaked in different concentrations of surfactant solution (2%, 4%, 6% w/w) prior to IL pretreatment. Tween 20, Tween 80 and polyethylene glycol 4000 (PEG) surfactants were tested and the results revealed major improvements in the yield of enzymatic hydrolysis...
June 15, 2017: Carbohydrate Polymers
Huan Liu, Zhe Sun, Xi Wang, Yonggang Wang, Guanghua Cheng
Graphene-like two-dimensional (2D) materials have shown remarkable broadband saturable absorption properties. These materials were successfully applied into mode locked lasers to generate laser pulses with the pulse duration from picosecond to femtosecond. However, these novel materials have not shown good performance as far in another important aspect: Q-switched lasers. Solid-state or fiber lasers Q-switched with broadband absorbers usually generated pulses of one hundred nanosecond to several microsecond, which show weak competitiveness compared to traditional absorbers such as Cr: YAG and semiconductor saturable absorption mirror (SESAM)...
March 20, 2017: Optics Express
Jimin Shim, Jae Won Lee, Ki Yoon Bae, Hee Joong Kim, Woo Young Yoon, Jong-Chan Lee
Lithium metal anode has fundamental problems concerning formation and growth of lithium dendrites which prevents practical applications of next generation of high-capacity lithium metal batteries. The synergistic combination of solid polymer electrolyte (SPE) crosslinked with naturally occurring terpenes and lithium powder anode is promising solution to resolve the dendrite issues by substituting conventional liquid electrolyte/separator and lithium foil anode system. A series of SPEs based on polysiloxane crosslinked with natural terpenes are prepared by facile thiol-ene click reaction under mild condition and structural effect of terpene crosslinkers on electrochemical properties is studied...
April 3, 2017: ChemSusChem
Ryoma Ishidate, Tomoyuki Ikai, Shigeyoshi Kanoh, Eiji Yashima, Katsuhiro Maeda
Novel poly(biphenylylacetylene) derivatives bearing two acetyloxy groups at the 2- and 2'-positions and an alkoxycarbonyl group at the 4'-position of the biphenyl pendants (poly-Ac's) were synthesized by the polymerization of the corresponding biphenylylacetylenes using a rhodium catalyst. The obtained stereoregular (cis-transoidal) poly-Ac's folded into a predominantly one-handed helical conformation accompanied by a preferred-handed axially twisted conformation of the biphenyl pendants through noncovalent interactions with a chiral alcohol and both the induced main-chain helicity and the pendant axial chirality were maintained, that is, memorized, after complete removal of the chiral alcohol...
March 29, 2017: Chirality
Kalle Sigfridsson, Lena Nilsson, Matti Ahlqvist, Thomas Andersson, Anna-Karin Granath
A compound, which is a selective peroxisome proliferator activated receptor (PPAR) agonist, was investigated. The aim of the presented studies was to evaluate the potential of the further development of the compound. Fundamental physicochemical properties and stability of the compound were characterized in solution by liquid chromatography and NMR and in solid-state by various techniques. The drug itself is a poorly soluble lipophilic acid with tendency to form aggregates in solution. The neutral form was only obtained in amorphous form with a glass-transition temperature of approximately 0°C...
March 30, 2017: European Journal of Pharmaceutical Sciences
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