An Ultrasonic Sensor for Process Modeling and Proces Control of Ceramic Superconductors
This research demonstrates the feasibility of utilizing nondestructive ultrasonic sensors to monitor the effects of oxygen content, processing time and temperature on the resultant mechanical, structural, and electrical properties of high temperature ceramic superconductors. Ultrasonic velocity changes, as a function of processing time and temperature, have clearly been shown to indicate the transformation between orthorhombic and tetragonal phases in Y-Ba-Cu-O.
Eighty consecutive cases of gamete intra-fallopian transfer.
Eighty patients with the main problems of unexplained infertility, oligospermia and endometriosis were treated with gamete intra-Fallopian transfer (GIFT). From 80 treatment cycles, 29 women conceived (36.3%). Of these, four were biochemical pregnancies and therefore the clinical pregnancy rate (25/80) was 31.2%. There were six sets of multiple pregnancies, a multiple pregnancy rate of 24%. Three women (12%) miscarried. The pregnancy rates in the patients with unexplained infertility, oligospermia and endometriosis were 33.3, 16.7 and 38.5%, respectively. The transfer of four oocytes appears to increase the pregnancy rate without increasing the risk of multiple pregnancy. The presence of in-vitro fertilization of excess oocytes after GIFT did not correlate with the final outcome of GIFT.
An anionic shell shields a cationic core allowing for uptake and release of polyelectrolytes within core-shell responsive microgels.
To realize carriers for drug delivery, cationic containers are required for anionic guests. Nevertheless, the toxicity of cationic carriers limits their practical use. In this study, we investigate a model system of polyampholyte N-isopropylacrylamide (NIPAM)-based microgels with a cationic core and an anionic shell to study whether the presence of a negative shell allows the cationic core to be shielded while still enabling the uptake and release of the anionic guest polyelectrolytes. These microgels are loaded with polystyrene sulfonate of different molecular weights to investigate the influence of their chain length on the uptake and release process. By means of small-angle neutron scattering, we evaluate the spatial distribution of polystyrene sulfonate within the microgels. The guest molecules are located in different parts of the core-shell microgels depending on their size. By combining these scattering results with UV-vis spectroscopy, electrophoretic mobility and potentiometric titrations we gain complementary results to investigate the uptake and release process of polyelectrolytes in polyampholyte core-shell microgels. Moreover, Brownian molecular dynamic simulations are performed to compare the experimental and theoretical results of this model. Our findings demonstrate that the presence of a shell still enables efficient uptake of guest molecules into the cationic core. These anionic guest molecules can be released through an anionic shell. Furthermore, the presence of a shell enhances the stability of the microgel-polyelectrolyte complexes with respect to the cationic precursor microgel alone.