Search results for "Ethylene"
showing 10 items of 2589 documents
Hydrophilicity Regulates the Stealth Properties of Polyphosphoester‐Coated Nanocarriers
2018
Increasing the plasma half-life is an important goal in the development of drug carriers, and can be effectively achieved through the attachment of polymers, in particular poly(ethylene glycol) (PEG). While the increased plasma half-life has been suggested to be a result of decreased overall protein adsorption on the hydrophilic surface in combination with the adsorption of specific proteins, the molecular reasons for the success of PEG and other hydrophilic polymers are still widely unknown. We prepared polyphosphoester-coated nanocarriers with defined hydrophilicity to control the stealth properties of the polymer shell. We found that the log P value of the copolymer controls the composit…
Effect of Palletized Map Storage on the Quality and Nutritional Compounds of the Japanese Plum cv. Angeleno (Prunus salicina Lindl.)
2016
The influence of active modified atmosphere packaging MAP (10.0 kPa of O2 and 5 kPa of CO2) on palletized system was evaluated to extend the marketability of fresh plums cv. Angeleno. Fruits were wrapped with a polyethylene film in pallet bag units at 1C and 90% relative humidity for up to 60 days. The gas values of the pallet bags, the fruit weight losses and their qualitative and nutraceutical characteristics were periodically monitored to evaluate the goodness of storage. The results showed as the pallet bag have maintained the market life of Angeleno plums to up to 60 days, preserving the most important qualitative traits of fruits. After 20, 40 and 60 days the MAP treatment maintained …
Aortic valve-sparing root replacement from inside the aorta using three Dacron skirts preserving the native Valsalva sinuses geometry and stabilizing…
2009
We present an alternative idea for valve-sparing technique combining the advantages of the reimplantation and the benefits of the remodeling techniques. We replace the sinuses of Valsalva using three Dacron skirts from inside of the aorta. The physiological anatomy of the Valsalva sinuses and their dynamic properties are preserved and the aortic commissures displacement avoided. The distal rim of each Dacron skirt was anchored to the aorto-ventricular junction using Ticron (2-0) U stitches placed from the ventricular side to the aortic side. We stabilize the base of the aortic annulus to prevent future dilation.
Implantation of Gore-Tex chordae on aortic valve leaflet to treat prolapse using "the chordae technique": surgical aspects and clinical results.
2008
Background Repair of prolapsed aortic valve leaflets has been considered a challenging technique for cardiac surgeons. In this paper we describe our surgical approach, "the chordae technique." It consists of the correction of aortic cusp prolapse by shortening the free margin length and of an adjustment of the leaflets coaptation height by anchoring the prolapsing cusp to the aortic wall at the sinotubular junction level. Methods Between February 2003 and December 2006, 26 patients with one or more prolapsed aortic leaflets underwent surgical repair using the new approach. The mean age of patients was 55 ± 10 years. There were 10 (38.5%) patients with grade II aortic valve regurgitation, 4 …
Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier
2015
Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most impor…
External reinforcement of varicose veins with PTFE prosthesis in infrainguinal bypass surgery -- clinical results.
2003
OBJECTIVE Segmental varicose degeneration of the autogenous greater saphenous vein may limit its use in infrainguinal bypass surgery. Wrapping a PTFE prosthesis around dilated veins has emerged as an option to create externally reinforced vein bypasses. Results regarding graft patency and limb salvage were analyzed. METHODS Between September 1995 and January 2001, 35 infrainguinal bypass operations in 33 patients were performed with greater saphenous veins exhibiting segmental varicose dilatation. Grafts were followed by duplex scan and retrospective analysis of graft patency and limb salvage was performed. RESULTS One bypass prompted successful revision for early occlusion. Four bypasses r…
Pollutant concentrations in placenta.
2011
Unborn children are exposed to environmental pollutants via the placenta, and there is a causal relationship between maternal intake of pollutants and fetal exposure. Placental examination is an effective way for acquiring data for estimating fetal exposure. We analyzed the concentrations of 104 congeners of persistent organic pollutants, seven organotin compounds, five heavy metals, and methylmercury in 130 randomly selected placentas. Additionally, we examined similarities between pollutant concentrations by analyzing correlations between their placental concentrations. Our results yield new information for conducting contaminant risk assessments for the prenatal period. Out of the 117 in…
Influence of the arrangement of the crystals and the structure of the noncrystalline regions on the mechanical properties of polyethylene terephthala…
2007
Amorphous samples of polyethylene terephthalate were stretched with different rates and stretching ratios at different temperatures. Afterwards they were crystallized. The arrangement of the crystals and the conformations of the chains in the noncrystalline regions were investigated by means of X-ray wide-angle scattering, X-ray small-angle scattering, birefringence measurements and nuclear magnetic resonance measurements. The influence of the morphological structure on the mechanical strength was determined. The stretching ratio itself generally does not characterize the orientation state. The structure obtained after crystallization depends mainly on the birefringence of the sample after …
Coarse Graining of Short Polythylene Chains for Studying Polymer Crystallization.
2015
We derive coarse-grained models of polyethylene in the melt state with the aim to study polymer crystallization. This requires a low level of coarse-graining: We use a mapping of two CH2 groups onto one bead. The coarse-grained beads are connected with harmonic springs, an optimized angular potential, and an optional torsional potential. Coarse-grained potentials are derived from detailed all-atom simulations, and an optimized form of the force field is then derived which achieves a good accuracy in reproducing the static properties of the chains. We address the question over which temperature range such models can be used, and in particular if the model is capable of reproducing the phase…
Event-based criteria in GT-STAF information indices: theory, exploratory diversity analysis and QSPR applications
2012
Versatile event-based approaches for the definition of novel information theory-based indices (IFIs) are presented. An event in this context is the criterion followed in the "discovery" of molecular substructures, which in turn serve as basis for the construction of the generalized incidence and relations frequency matrices, Q and F, respectively. From the resultant F, Shannon's, mutual, conditional and joint entropy-based IFIs are computed. In previous reports, an event named connected subgraphs was presented. The present study is an extension of this notion, in which we introduce other events, namely: terminal paths, vertex path incidence, quantum subgraphs, walks of length k, Sach's subg…