Search results for " Phase"
showing 10 items of 1862 documents
Stability of Asymmetric Lipid Bilayers Assessed by Molecular Dynamics Simulations
2009
The asymmetric insertion of amphiphiles into biological membranes compromises the balance between the inner and outer monolayers. As a result, area expansion of the receiving leaflet and curvature strain may lead to membrane permeation, shape changes, or membrane fusion events. We have conducted both atomistic and coarse-grained molecular dynamics simulations of dipalmitoyl-phosphatidylcholine (DPPC) bilayers to study the effect of an asymmetric distribution of lipids between the two monolayers on membrane stability. Highly asymmetric lipid bilayers were found to be surprisingly stable within the submicrosecond time span of the simulations. Even the limiting case of a monolayer immersed in …
Influence of Centerline Intermetallic Stringers on Pitting Corrosion Resistance of Superduplex Stainless Steel
2021
Superduplex stainless steel UNS S32750 / EN 1.4410 is commonly used in marine environment, petrochemical, oil and gas, chemical and desalination industries, requiring materials with superior corrosion and mechanical properties. Very few residual intermetallic particles may be present under the form of centerline stringers whose effects on corrosion properties are not well documented. A previous study demonstrated the negligible influence of the intermetallic phases in centerline stringers (typically < 0.1% over thickness) on the hydrogen embrittlement susceptibility of superduplex stainless steel [1]. The present study aims at highlighting the impact of centerline intermetallic stringers on…
Synthesis, antiproliferative activity and possible mechanism of action of novel 2-acetamidobenzamides bearing the 2-phenoxy functionality.
2015
Several new 2-(2-phenoxyacetamido)benzamides 17a-v, 21 and 22 were synthesized by stirring in pyridine the acid chlorides 16a-e and the appropriate5-R-4-R1-2-aminobenzamide 15a-e and initially evaluated in vitro for antiproliferative activity against the K562 (human chronic myelogenous leukemia) cell line. Some of synthesized compounds were evaluated for their in vitro antiproliferative activity against the full NCI tumor cell line panel derived from nine clinically isolated cancer types (leukemia, non-small cell lung, colon, CNS, melanoma, ovarian, renal, prostate and breast). The most active compounds caused an arrest of K562 cells in the G0-G1 phase of cell cycle and induction of apoptos…
PEG 400/Cerium Ammonium Nitrate Combined with Microwave-Assisted Synthesis for Rapid Access to Beta-Amino Ketones. An Easy-to-Use Protocol for Discov…
2018
Compound libraries are important requirement in target-based drug discovery. In the present work, a small focused compound library based on β-aminoketone scaffold has been prepared combining microwave-assisted organic synthesis (MAOS) with polymer-assisted solution phase synthesis (PASPS) and replacing reaction workup standard purification procedures with solid phase extraction (SPE). Specifically, the effects of solvent, such as dioxane, dimethylformamide (DMF), polyethylene glycol 400 (PEG 400), temperature, irradiation time, stoichiometric ratio of reagents, and catalysts (HCl, acetic acid, cerium ammonium nitrate (CAN)) were investigated to maximize both conversion and yield. The optimi…
PLLA scaffolds with controlled architecture as potential microenvironment for in vitro tumor model
2019
Abstract The "microenvironment" where a tumor develops plays a fundamental role in determining its progression, the onset of metastasis and, eventually, its resistance to therapies. Tumor cells can be considered more or less invasive depending both on the nature of the cells and on the site where they are located. Commonly adopted laboratory culture protocols for the investigation of tumor cells take usually place on standard two-dimensional supports. However, such cultures do not allow for reproduction of the biophysical properties of the tumor’s microenvironment, thus causing the cells to lose most of their relevant characteristics. In this work MDA-MB 231 breast cancer cells were cultiva…
Formation of 3-methyl-1,2,3-butanetricarboxylic acid via gas phase oxidation of pinonic acid – a mass spectrometric study of SOA aging
2012
Abstract. This paper presents the results of mass spectrometric investigations of the OH-initiated oxidative aging of α-pinene SOA under simulated tropospheric conditions at the large aerosol chamber facility AIDA, Karlsruhe Institute of Technology. In particular, the OH-initiated oxidation of pure pinic and pinonic acid, two well-known oxidation products of α-pinene, was investigated. Two complementary analytical techniques were used, on-line atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) and filter sampling followed by liquid chromatography/mass spectrometry (LC/ESI-MS). The results show that 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a very low volatile α-pine…
Thermomineral waters of Greece: geochemical characterization
2020
Monte Carlo simulations of the solid-liquid transition in hard spheres and colloid-polymer mixtures
2010
Monte Carlo simulations at constant pressure are performed to study coexistence and interfacial properties of the liquid-solid transition in hard spheres and in colloid-polymer mixtures. The latter system is described as a one-component Asakura-Oosawa (AO) model where the polymer's degrees of freedom are incorporated via an attractive part in the effective potential for the colloid-colloid interactions. For the considered AO model, the polymer reservoir packing fraction is eta_p^r=0.1 and the colloid-polymer size ratio is q=sigma_p/\sigma=0.15 (with sigma_p and sigma the diameter of polymers and colloids, respectively). Inhomogeneous solid-liquid systems are prepared by placing the solid fc…