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Being able to bind, select, and transport species is central to a number of fields, including medicine, materials, and environmental science. In particular, recognizing a specific species from one phase and transporting it across, or into another phase, has obvious applications in environ-mental science, for example, removal of unwanted or toxic materials from an aqueous or organic phase. In this paper, we describe an approach that uses a functionalized dendritic polymer to bind and transport a small anionic molecule across an organic phase (and between two aqueous phases). The design was based on encapsulation principles borrowed from nature, where anions are bound and transported by proteins that have specific sites within their globular ordered structures. For the work reported here, a globular dendritic polymer functionalized with an isophthalamide-based receptor was used to replace the protein structure and anion-binding site. Along with control experiments, the binding and transport properties of two functionalized HBPs were assessed using a Pressman U tube experiment. Both HBPs demonstrated an enhanced ability to bind and transport anions (when compared to the anion-binding site used in isolation). Furthermore, optimum binding and transport occurred when the smaller of the two HBPs were used. This supports our previous observations regarding the existence of a dense packed limit for HBPs. 相似文献
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Introduction
Elastic modulus estimation may be an important clinical criterion, as it seems to affect such eye parameters as intraocular pressure, ocular pulsation, blood flow, effect of topical medications, and post-refractive surgery complications. The purpose of this study was to examine the differences in elasticity in the ocular axial length, posterior wall thickness (posterior pole), and retina-choroid thickness under normal and aged-related macular degeneration (AMD) conditions in the human eye by directly estimating the elastic modulus with sequential and noninvasive ultrasound image processing.Materials and Methods
In this study, 25 healthy subjects and 20 patients with non-neovascular AMD participated in the experiment. The deformation of the ocular axial length, posterior wall thickness and retina-choroid complex thickness was captured using high-resolution ultrasonography before and after loading. The B-mode (20 MHz) and A-mode (8 MHz) frames were obtained and processed with an echo tracking technique. The elastic modulus was estimated using changes in ocular axial length, posterior wall thickness and retina-choroid complex thickness and with applied stress measurements.Results
There was a significant difference (p < 0.05) in the ocular axial length elastic modulus between the AMD and healthy subjects (AMD patients: 95.165 ± 26.431 kPa, vs. healthy subjects: 49.539 ± 25.867 kPa). Moreover, there was a statistically significant difference (p < 0.05) in the posterior wall thickness elastic modulus between AMD patients and healthy subjects (AMD patients: 50.519 ± 12.295 kPa, vs. healthy subjects: 20.519 ± 11.827 kPa). However, no statistically significant difference (p-value > 0.05) was found in the retina-choroid complex elastic modulus between the two groups (AMD patients: 20.134 ± 3.898 kPa, vs. healthy subjects: 15.630 ± 4.250 kPa).Conclusion
Although the results were obtained examining a relatively low number of patients, it would appear that noninvasive ultrasound estimation of the local elastic moduli of ocular axial length and posterior wall thickness is suited to aid in detection of the non-exudative AMD thus manifesting its potential as a screening tool in symptom-free individuals. 相似文献3.
M. Mansori C. Favotto K. Jardet M. Roubin A. Sebaoun P. Satre 《Journal of Thermal Analysis and Calorimetry》1997,50(3):401-407
The oxygen exchange between the condensed phase(s) and the gas phase was studied as a function of temperature for superconducting phases of the system (Bi,Pb)-Sr-Ca-Cu-O.An oxygen probe apparatus allowed confirmation that the variation in oxygen composition in the Pb2212 and Pb2223 superconducting phases is a reversible phenomenon on heating and cooling. It was demonstrated that the mass loss of both phases, for the 905 and 980°C isotherms, was due to the oxygen composition variation and to PbO loss (this latter phenomenon begin irreversible). 相似文献
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A. Sebaoun P. Satre M. Mansori A. L'Honore 《Journal of Thermal Analysis and Calorimetry》1997,48(5):971-980
TG-DTA and X-ray diffraction measurements at different temperatures and under different oxygen partial pressures were carried out on the species Bi1.6Pb0.4Sr2CuO6±x, Bi1.6Pb0.4Sr2CaCu2O8±y and Bi1.6Pb0.4Sr2Ca2Cu3O10±z to analyse the influence of the oxygen chemical potential on the phase transformations. A new phase was found at isobaric invariant equilibrium for 0.5
/PTot1 at 884°C. This new phase presents a buffer effect towards oxygen exchange between superconducting oxides and the gas phase.This work has benefited from partial financial support by the Centre National d'Etudes Spatiales (C.N.E.S.). It is a pleasure to thank Prof. Yasuhiko Syono of Tohoku University - Sendai- Japan for valuable discussions. 相似文献
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In this work, we present the synthesis and the characterization of ionic conducting ceramics of NaSICON-type (Natrium super ionic conductor). The properties of this ceramic make it suitable for use in electrochemical devices. These solid electrolytes can be used as sensors for application in the manufacturing of potentiometric gas sensors, for the detection of pollutant emissions and for environment control. The family of NaSICON that we studied has as a general formula Na2.8Zr2−ySi1.8−4yP1.2+4yO12 with 0?y?0.45. The various compositions were synthesized by produced using the sol-gel method. The electric properties of these compositions were carried out by impedance spectroscopy. The results highlight the good conductivity of the Na2.8Zr1.775Si0.9P2.1O12 composition. 相似文献
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Saeed Nojavan Zeinab Tahmasebi Tina Bidarmanesh Hamideh Behdad Mahnaz Nasiri‐Aghdam Sozan Mansori Ahmad Pourahadi 《Journal of separation science》2013,36(19):3256-3263
An electromembrane extraction procedure coupled with HPLC and visible detection was applied for the extraction of three textile azo dyes as organic salts. The extraction parameters such as extraction time, applied voltage, pH range, and concentration of salt added were optimized. A driving force of 60 V was applied to extract the analytes through 2‐nitrophenyl octyl ether, used as the supported liquid membrane, into a neutral aqueous solution. This method required 20 min extraction time from a neutral sample solution. The proposed microextraction technique provided good linearity with correlation coefficients from 0.996 to 0.998 over a concentration range of 1.0–1000.0 ng/mL. The LODs of dyes were 0.30–0.75 ng/mL, while the reproducibility ranged from 6.7 to 12.9% (n = 6). Also, enrichment factors of 96–162 that corresponded to the recoveries ranging from 48 to 81% were achieved. Finally, the application of this new method was demonstrated on wastewater samples and some plants grown in contaminated environments. Excellent selectivity was obtained as no interfering peaks were detected. 相似文献
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