Search results for "HILIC"
showing 10 items of 745 documents
Synthesis of Mesoporous Supraparticles on Superamphiphobic Surfaces
2015
A method for mesoporous supraparticle synthesis on superamphiphobic surfaces is designed. Therefore, supraparticles assembled with nanoparticles are synthesized by the evaporation of nanoparticle dispersion drops on the superamphiphobic surface. For synthesis, no further purification is required and no organic solvents are wasted. Moreover, by changing the conditions such as drop size and concentration, supraparticles of different sizes, compositions, and architectures are fabricated.
Refractive index and equilibrium water content of conventional and silicone hydrogel contact lenses
2006
Prova tipográfica (In Press)
Lipid phase transition in saccharide-coated cholate-containing liposomes: coupling to the surrounding matrix.
2005
We performed FTIR measurements on cholate-containing liposomes (CCL) embedded in saccharide (trehalose or sucrose) matrixes with different contents of residual water. We obtained information on the CCL phase transition following the thermal evolution (310-70 K) of the IR spectrum of the carbonyl moieties of phospholipids in the frequency range 4225-4550 cm(-1). Furthermore, we simultaneously followed the thermal evolution of the water association band, which gave information on the behavior of the surrounding water-saccharide matrix. The analysis revealed a small sub-band of the water association band present in CCL but not in cholate-free liposomes, the thermal evolution of which is tightl…
Halogen‐Imparted Reactivity in Lithium Carbenoid Mediated Homologations of Imine Surrogates: Direct Assembly of bis‐Trifluoromethyl‐β‐Diketiminates a…
2020
The selective formal insertion (homologation) of a carbon unit bridging the two trifluoroacetamidoyl chlorides (TFAICs) units is reported. The tactic is levered on a highly chemoselective homologation-metalation-acyl nucleophilic substitution sequence which precisely enables to assemble novel trifluoromethylated β-diketiminates within a single synthetic operation. Unlike previous homologations conducted with LiCH2Cl furnishing aziridines, herein we exploit the unique capability of iodomethyllithium to act contemporaneously as a C1 source (homologating effect) and metalating agent. The mechanistic rationale grounded on experimental evidences supports the hypothesized proposal and, the struct…
Diastereoselective synthesis of 2-phenyl-3-(trifluoromethyl)piperazines as building blocks for drug discovery.
2014
The synthesis of enantiomerically pure cis- and trans-2-phenyl-3-(trifluoromethyl)piperazines is described. It involved, as the key step, a diastereoselective nucleophilic addition of the Ruppert-Prakash reagent (TMSCF3) to alpha-amino sulfinylimines bearing Ellman's auxiliary. This methodology allows an entry into hitherto unknown trifluoromethylated and stereochemically defined piperazines, key scaffold components in medicinal chemistry.
Rapid determination of sterols in vegetable oils by CEC using methacrylate ester-based monolithic columns
2008
A method for the determination of sterols in vegetable oils by CEC with UV-Vis detection, using methacrylate ester-based monolithic columns, has been developed. To prepare the columns, polymerization mixtures containing monomers of different hydrophobicities were tried. The influence of composition of polymerization mixture was optimized in terms of porogenic solvent, monomers/porogens and monomer/crosslinker ratios. The composition of the mobile phase was also studied. The optimum monolith was obtained with lauryl methacrylate monomer at 60:40% (wt:wt) lauryl methacrylate/ethylene dimethacrylate ratio and 60 wt% porogens with 20 wt% of 1,4-butanediol (12 wt% 1,4-butanediol in the polymeriz…
Multivariate optimization of the hollow fibre liquid phase microextraction of muscimol in human urine samples.
2016
Abstract A liquid phase microextraction based on hollow fibre followed by liquid chromatographic determination was developed for the extraction and quantitation of the hallucinogenic muscimol from urine samples. Method applicability on polar hallucinogens was also tested on two alkaloids, a psychedelic hallucinogen, tryptamine and a polar amino acid, tryptophan which exists in its charged state in the entire pH range. A multivariate design of experiments was used in which a half fractional factorial approach was applied to screen six factors (donor phase pH, acceptor phase HCl concentration, carrier composition, stirring rate, extraction time and salt content) for their extent of vitality i…
Comparative Study of Different Column Types for the Separation of Polar Basic Hallucinogenic Alkaloids
2016
The number of hallucinogenic compounds that have been separated simultaneously by liquid chromatography is limited. This research aimed to identify a column(s) that can allow for separation of several hallucinogens. The extent of separation of seven polar hallucinogenic tryptamine and phenethylamine derived alkaloids containing a basic N atom that becomes protonated at low pH values were investigated on five reverse-based columns and one hydrophilic interaction liquid chromatography (HILIC) column. An RP-phenyl and a negatively charged fused core HILIC were identified and recommended as effective columns in this regard. This research is the first to introduce a HILIC column in separation of…
Analysis of the Biological Response of Endothelial and Fibroblast Cells Cultured on Synthetic Scaffolds with Various Hydrophilic/Hydrophobic Ratios: …
2009
In this study we developed polymer scaffolds intended as anchorage rings for cornea prostheses among other applications, and examined their cell compatibility. In particular, a series of interconnected porous polymer scaffolds with pore sizes from 80 to 110 microns were manufactured varying the ratio of hydrophobic to hydrophilic monomeric units along the polymer chains. Further, the effects of fibronectin precoating, a physiological adhesion molecule, were tested. The interactions between the normal human fibroblast cell line MRC-5 and primary human umbilical vein endothelial cells (HUVECs) with the scaffold surfaces were evaluated. Adhesion and growth of the cells was examined by confocal…
A conservative treatment for eosinophilic cystitis
2022
Introduction: Eosinophilic cystitis is a rare condition which causes common symptoms and may mimic other conditions. Eosinophilic cystitis has several causes such as hypereosinophilic syndrome, inflammatory diseases, neoplasia, parasites or fungal infection, IgE-related diseases, Drug Reaction and Eosinophilia and Systemic Symptoms (DRESS) syndrome, or Churg-Strauss syndrome. Therefore, differential diagnosis is difficult. Case presentation: We report the case of a middle-aged man affected by eosinophilic cystitis with persistent hematuria and other peculiar symptoms that may be brought back to hypereosinophilic crisis. Conclusion: Conservative approach is preferred, avoiding radical cystec…