The influence of cholesterol on the structure of unilamellar-vesicle (ULV) phospholipid bilayers is studied using small-angle
neutron scattering. ULVs made up of short-, mid- and long-chain monounsaturated phospholipids (diCn :1PC, n = 14 , 18, 22, respectively) are examined over a range (0-45mol %) of cholesterol concentrations. Cholesterol's effect on
bilayer structure is characterized through changes to the lipid's transmembrane thickness, lateral area and headgroup hydration.
For all three lipids, analysis of the experimental data shows that the addition of cholesterol results in a monotonic increase
of these parameters. In the case of the short- and mid-chain lipids, this is an expected result, however, such a finding was
unexpected for the long-chain lipid. This implies that cholesterol has a pronounced effect on the lipid's hydrocarbon chain
organization. 相似文献
Proteomic characterization of alveolar bones in oral surgery represents an analytical challenge due to their insoluble character. The implementation of a straightforward technique could lead to the routine use of proteomics in this field. This work thus developed a simple technique for the characterization of bone tissue for human maxillary and mandibular bones. It is based on the direct in-bone tryptic digestion of proteins in both healthy and pathological human maxillary and mandibular bone samples. The released peptides were then identified by the LC-MS/MS. Using this approach, a total of 1120 proteins were identified in the maxillary bone and 1151 proteins in the mandibular bone. The subsequent partial least squares–discrimination analysis (PLS-DA) of protein data made it possible to reach 100% discrimination between the samples of healthy alveolar bones and those of the bone tissue surrounding the inflammatory focus. These results indicate that the in-bone protein digestion followed by the LC-MS/MS and subsequent statistical analysis can provide a deeper insight into the field of oral surgery at the molecular level. Furthermore, it could also have a diagnostic potential in the differentiation between the proteomic patterns of healthy and pathological alveolar bone tissue. Data are available via ProteomeXchange with the identifier PXD026775. 相似文献
Journal of Radioanalytical and Nuclear Chemistry - The aim of this study is the synthesis of a novel 99mTc-labeld graft polymer and the biological evaluation of its in vitro and in vivo properties.... 相似文献
Reactive species generated in the gas and in water by cold air plasma of the transient spark discharge in various N2/O2 gas mixtures (including pure N2 and pure O2) have been examined. The discharge was operated without/with circulated water driven down the inclined grounded electrode. Without water, NO and NO2 are typically produced with maximum concentrations at 50% O2. N2O was also present for low O2 contents (up to 20%), while O3 was generated only in pure O2. With water, gaseous NO and NO2 concentrations were lower, N2O was completely suppressed and HNO2 increased; and O3 was lowered in O2 gas. All species production decreased with the gas flow rate increasing from 0.5 to 2.2 L/min. Liquid phase species (H2O2, NO2 ̄, NO3 ̄, ·OH) were detected in plasma treated water. H2O2 reached the highest concentrations in pure N2 and O2. On the other hand, nitrites NO2 ̄ and nitrates NO3 ̄ peaked between 20 and 80% O2 and were associated with pH reduction. The concentrations of all species increased with the plasma treatment time. Aqueous ·OH radicals were analyzed by terephthalic acid fluorescence and their concentration correlated with H2O2. The antibacterial efficacy of the transient spark on bacteria in water increased with water treatment time and was found the strongest in the air-like mixture thanks to the peroxynitrite formation. Yet, significant antibacterial effects were found even in pure N2 and in pure O2 most likely due to high ·OH radical concentrations. Controlling the N2/O2 ratio in the gas mixture, gas flow rate, and water treatment time enables tuning the antibacterial efficacy.
Chlorination reaction behavior of Zircaloy-4 (Zry-4) cladding hulls was demonstrated by using a quartz reactor system. By
reacting at 380 °C for 3 h, mass of the Zry-4 hulls decreased by 65.8 wt% with Cl2 utilization of 87.1 mol%. Composition of collected product was analyzed and it was revealed that concentration of Zr was
higher than 99.97 wt%. The purity of Zr in the experimental result was higher than expectation when considering Sn (1.31 wt%)
and Fe (0.25 wt%) contents which can produce gaseous SnCl4 and FeCl3 at the experimental condition. Theoretical calculations were performed to clarify the high purity of Zr by using the HSC
code. The simulation results revealed that formation of ZrCl4 is more preferred than SnCl4, FeCl3, and CrCl3. The preference of chloride formation was confirmed by the theoretical calculation, and it was suggested that the major constituents
of Zry-4 might react with Cl2 to produce chlorides in an order of ZrCl4 > CrCl3 > SnCl4 > FeCl3. It was also suggested that continuous removal of ZrCl4 and sufficient supply of Zr source during the chlorination reaction might have contributed to the high purity of Zr. 相似文献
A water-soluble sulfonate poly(ethylene terephthalate) copolymer has been synthesized and identified as a high-temperature
endurable surfactant. The glass-transition temperature and the storage modulus increase in correlation to the increase in
sulfonate content. Various characterization studies were performed, including light scattering, zeta-potential measurement
and a sedimentation test. The results suggest that at equal numbers of sulfonate units in a solution, a low concentration
of a dispersant of high sulfonate content is more effective than a high concentration of a dispersant of low sulfonate content.
Received: 6 April 2000 Accepted: 23 September 2000 相似文献