497 research outputs found
The impact of alkyl chain purity on lipid based nucleic acid delivery systems – is the utilization of lipid components with technical grade justified?
The physicochemical properties and transfection efficacies of two samples of a cationic lipid have been investigated and compared in 2D (monolayers at the air/liquid interface) and 3D (aqueous bulk dispersions) model systems using different techniques. The samples differ only in their chain composition due to the purity of the oleylamine (chain precursor). Lipid 8 (using the oleylamine of technical grade for cost-efficient synthesis) shows lateral phase separation in the Langmuir layers. However, the amount of attached DNA, determined by IRRAS, is for both samples the same. In 3D systems, lipid 8 p forms cubic phases, which disappear after addition of DNA. At physiological temperatures, both lipids (alone and in mixture with cholesterol) assemble to lamellar aggregates and exhibit comparable DNA delivery efficiency. This study demonstrates that non-lamellar structures are not compulsory for high transfection rates. The results legitimate the utilization of oleyl chains of technical grade in the synthesis of cationic transfection lipid
Quali-quantitative analysis of flavonoides of Cornus mas L. (Cornaceae) fruts.
The methanol extract obtained from the ripe fruits of Cornus mas L. (Cornaceae) have been phytochemically
studied. On the basis of HPLC–PDA–MS/MSn analysis eight compounds have been identified as
quercetin, kaempferol, and aromadendrin glycosilated derivatives. Three major compounds have been
also isolated by Sephadex LH-20 column chromatography followed by HPLC and characterised by NMR
spectroscopy. Moreover, LC–PDA–MS analysis of the red pigment revealed the presence of three anthocyanins.
The quantitative analysis of all compounds was reported
libcloudph++ 2.0: aqueous-phase chemistry extension of the particle-based cloud microphysics scheme
This paper introduces a new scheme available in the
library of algorithms for representing cloud microphysics in numerical models
named libcloudph++.
The scheme extends the particle-based microphysics scheme with a Monte Carlo coalescence
available in libcloudph++ to the aqueous-phase chemical processes occurring within cloud droplets.
The representation of chemical processes focuses on the aqueous-phase oxidation
of the dissolved SO2 by O3 and H2O2.
The particle-based microphysics and chemistry scheme
allows for tracking of the changes in the cloud condensation nuclei (CCN) distribution
caused by both collisions between cloud droplets and aqueous-phase oxidation.The scheme is implemented in C++ and equipped with
bindings to Python.
The scheme can be used on either a CPU or a GPU, and is distributed under the GPLv3 license.
Here, the particle-based microphysics and chemistry scheme is tested in a simple
0-dimensional adiabatic parcel model and then
used in a 2-dimensional prescribed flow framework.
The results are discussed with a focus on changes to the CCN sizes
and comparison with other model simulations discussed in the literature.</p
Lamellar versus micellar structures-aggregation behavior of a three-chain cationic lipid designed for nonviral polynucleotide transfer
Polymorphism of DNA mismatch repair genes in endometrial cancer
Endometrial cancer (EC) is the second most common malignancy associated with hereditary non-polyposis colorectal cancer (HNPCC) family. The development of HNPCC is associated with defects in DNA mismatch repair (MMR) pathway resulting in microsatellite instability (MSI). MSI is present in a greater number of EC than can be accounted for by inherited MMR mutations, therefore alternative mechanisms may underline defective MMR in EC, including polymorphic variation. Aim: We checked the association between EC occurrence and two polymorphisms of MMR genes: a 1032G>A (rs4987188) transition in the hMSH2 gene resulting in a Gly22Asp substitution and a –93G>A (rs1800734) transition in the promoter of the hMLH1 gene. Material and methods: These polymorphisms were genotyped in DNA from peripheral blood lymphocytes of 100 EC patients and 100 age-matched women by restriction fragment length polymorphism PCR. Results: A positive association (OR 4.18; 95% CI 2.23–7.84) was found for the G/A genotype of the –93G>A polymorphism of the hMLH1 gene and EC occurrence. On the other hand, the A allele of this polymorphism was associated with decreased EC occurrence. The Gly/Gly genotype slightly increased the effect of the –93G>A-G/A genotype (OR 4.52; CI 2.41–8.49). Our results suggest that the –93G>A polymorphism of the hMLH1 gene singly and in combination with the Gly322Asp polymorphism of the hMSH2 gene may increase the risk of EC. Key Words: hMSH2, hMLH1, endometrial cancer, genetic polymorphism, MMR
Multifunctional platform based on electrospun nanofibers and plasmonic hydrogel. A smart nanostructured pillow for near-infrared light-driven biomedical applications
Multifunctional nanomaterials with the ability to respond to near-infrared (NIR) light stimulation are vital for the development of highly efficient biomedical nanoplatforms with a polytherapeutic approach. Inspired by the mesoglea structure of jellyfish bells, a biomimetic multifunctional nanostructured pillow with fast photothermal responsiveness for NIR light-controlled on-demand drug delivery is developed. We fabricate a nanoplatform with several hierarchical levels designed to generate a series of controlled, rapid, and reversible cascade-like structural changes upon NIR light irradiation. The mechanical contraction of the nanostructured platform, resulting from the increase of temperature to 42 °C due to plasmonic hydrogel-light interaction, causes a rapid expulsion of water from the inner structure, passing through an electrospun membrane anchored onto the hydrogel core. The mutual effects of the rise in temperature and water flow stimulate the release of molecules from the nanofibers. To expand the potential applications of the biomimetic platform, the photothermal responsiveness to reach the typical temperature level for performing photothermal therapy (PTT) is designed. The on-demand drug model penetration into pig tissue demonstrates the efficiency of the nanostructured platform in the rapid and controlled release of molecules, while the high biocompatibility confirms the pillow potential for biomedical applications based on the NIR light-driven multitherapy strategy
Measurement of event-by-event transverse momentum and multiplicity fluctuations using strongly intensive measures and in nucleus-nucleus collisions at the CERN Super Proton Synchrotron
Results from the NA49 experiment at the CERN SPS are presented on
event-by-event transverse momentum and multiplicity fluctuations of charged
particles, produced at forward rapidities in central Pb+Pb interactions at beam
momenta 20, 30, 40, 80, and 158 GeV/c, as well as in systems of
different size (, C+C, Si+Si, and Pb+Pb) at 158 GeV/c. This publication
extends the previous NA49 measurements of the strongly intensive measure
by a study of the recently proposed strongly intensive measures of
fluctuations and . In the explored kinematic
region transverse momentum and multiplicity fluctuations show no significant
energy dependence in the SPS energy range. However, a remarkable system size
dependence is observed for both and , with the
largest values measured in peripheral Pb+Pb interactions. The results are
compared with NA61/SHINE measurements in collisions, as well as with
predictions of the UrQMD and EPOS models.Comment: 12 pages, 14 figures, to be submitted to PR
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