Search results for " SURFACTANT"

Hydrophobin (HFBI): a potential fusion partner for one-step purification of recombinant proteins from insect cells

2008

Hydrophobins play an important role in binding and assembly of fungal surface structures as well as in medium-air interactions. These, hydrophobic properties provide interesting possibilities when purification of macromolecules is concerned. In aqueous micellar two-phase systems, based on surfactants, the water soluble hydrophobins are concentrated inside micellar structures and, thus, distributed to defined aqueous phases. This, one-step purification is attractive particularly when large-scale production of recombinant proteins is concerned. In the present study the hydrophobin HFBI of Trichoderma reesei was expressed as an N-terminal fusion with chicken avidin in baculovirus infected inse…

AlTf-UVM-7—Highly active catalysts for the synthesis of long chain symmetrical ethers and non-ionic surfactant structures

2010

New Lewis acid AlTf-UVM-7 catalysts with bimodal pore system and different Si to Al ratios were prepared in a two-step synthesis in which triflic acid (Tf) was incorporated into previously synthesized mesoporous aluminum-containing silica. The Al incorporation inside the pore walls was carried out through the Atrane method. The characterization of the resulted catalysts showed that the triflic acid treatment step did not damage the texture or the structure of the catalysts. These materials were used as green catalysts for the etherification of fatty alcohols and the conversion of ethylene glycol (EG) with n-octanol resulting in mixtures of short ethoxylated structures with a large distribut…

Amino-Acid-Based Polymerizable Surfactants for the Synthesis of Chiral Nanoparticles

2016

Amino-acid-based chiral surfactants with polymerizable moieties are synthesized, and a versatile approach to prepare particles thereof with a chiral surface functionality is presented. As an example of an application, the synthesized particles are tested for their ability as nucleating agents in the enantioselective crystallization of amino acid conglomerate systems, taking rac-asparagine as a model system. Particles resulting from chiral surfactants with different tail groups are compared and the results demonstrate that only the chiral nanoparticles made of the polymerizable surfactant are able to act efficiently as nucleation agent in enantioselective crystallization.

On the effect of the nature of counterions on the self-assembly of polyoxyethylene alkyl ether carboxylic acids

2020

In this contribution, we investigate the effect of the type of counterion on the properties of dilute solutions of polyoxyethylene alkyl ether carboxylic acids. Two different surfactants, presenting an oleic acid alkyl chain and on-average five and nine ethylene oxide units, and terminated by a weakly anionic carboxymethyl group were studied. The surfactants were gradually ionized with sodium hydroxide, arginine, and choline hydroxide. The solutions properties were probed by light scattering, electrophoretic mobility, density and sound velocity measurements, as well as by small-angle neutron scattering. To our initial surprise, no specific effect arising from the nature of the counterion co…

Hyaluronic Acid Present in the Tumor Microenvironment Can Negate the Pro-apototic Effect of a Recombinant Fragment of Human Surfactant Protein D on B…

2020

Copyright © 2020 Murugaiah, Agostinis, Varghese, Belmonte, Vieni, Alaql, Alrokayan, Khan, Kaur, Roberts, Madan, Bulla and Kishore. Human surfactant protein D (SP-D) belongs to the family of collectins that is composed of a characteristic amino-terminal collagenous region and a carboxy-terminal C-type lectin domain. Being present at the mucosal surfaces, SP-D acts as is a potent innate immune molecule and offers protection against non-self and altered self-such as pathogens, allergens, and tumour. Here, we examined the effect of a recombinant fragment of human SP-D (rfhSP-D) on a range of breast cancer lines. Breast cancer has four molecular subtypes characterised by varied expression of oes…

Liquid Phase Micro-Extraction of Linear Alkylbenzene Sulfonate Anionic Surfactants in Aqueous Samples

2011

Hollow fiber liquid phase micro-extraction (LPME) of linear alkylbenzene sulfonates (LAS) from aqueous samples was studied. Ion pair extraction of C10, C11, C12 and C13 homologues was facilitated with trihexylamine as ion-pairing agent, using di-n-hexylether as solvent for the supported liquid membrane (SLM). Effects of extraction time, acceptor buffer concentration, stirring speed, sample volume, NaCl and humic acids were studied. At 10–50 µg L−1 linear R2-coefficients were 0.99 for C10 and C11 and 0.96 for C12. RSD was typically ~15%. Three observations were especially made. Firstly, LPME for these analytes was unusually slow with maximum enrichment observed after 15–24 h (depending on sa…

MASS SPECTROMETRY IN THE STUDY OF PHOSPHATIDYLCHOLINE ADDUCTS

2008

Supramolecular surfactant aggregates in gas-phase:monocharged sodium alkanesulfonate clusters

2009

Effects of ultrasonically activated irrigants with or without surfactant on smear layer removal after post space preparation

2012

The aim of this study was to compare the effects of different NaOCl and EDTA formulations with/without ultrasonic use on smear layer removal and root canal surface characteristics after post space preparation. Study design: After post space preparations, forty-six teeth were subjected to different post space irrigation regimes; G1, 17% EDTA; G2, 17% EDTA+Ultrasonic activation; G3, EDTA-T; G4, EDTA-T+Ultrasonic activation; G5, NaOCl; G6, NaOCl+Ultrasonic activation. Specimens were examined under scanning electron microscope and scored for debris and smear layer removal and dentinal tubule opening and statistically analyzed with Kruskal Wallis and Dunn's test. Significance value was set at p<…

Supraglottic airway devices for surfactant treatment: systematic review and meta-analysis

2019

Objective: To compare surfactant administration via supraglottic airway device (SAD) vs. nasal CPAP alone or INSURE. Study design: A systematic search of PubMed, EMBASE, SCOPUS, Cochrane Central Register of Controlled Trials and Clinicaltrials.gov was performed. Articles meeting inclusion criteria (RCT, surfactant administration via SAD, laryngeal mask, I-gel) were assessed Results: Five RCTs were eligible. Surfactant administration via SAD reduced the need for intubation/mechanical ventilation (RR 0.57, 95%CI 0.38–0.85) and short-term oxygen requirements (MD −8.00, 95%CI −11.09 to −4.91) compared to nCPAP alone. Surfactant administration via SAD reduced the need for intubation/mechanical v…