Tetz M.,Berlin Eye Research Institute |
Jorgensen M.R.,Institute for Integrative Nanosciences
Current Eye Research | Year: 2015
An introduction to the history of intraocular lenses (IOLs) is given, leading up to modern hydrophobic examples. The roles of hydrophobicity, hygroscopy, materials chemistry, and edge design are discussed in the context of IOLs. The four major types of IOL materials are compared in terms of their chemistry and biocompatibility. An example of a modern "hydrophobic" acrylic polymer with higher water content is discussed in detail. © 2015 © 2015 Taylor & Francis Group, LLC.
Home > Press > 'Spermbots' could help women trying to conceive (video) Abstract: Sperm that don't swim well rank high among the main causes of infertility. To give these cells a boost, women trying to conceive can turn to artificial insemination or other assisted reproduction techniques, but success can be elusive. In an attempt to improve these odds, scientists have developed motorized "spermbots" that can deliver poor swimmers -- that are otherwise healthy -- to an egg. Their report appears in ACS' journal Nano Letters. Artificial insemination is a relatively inexpensive and simple technique that involves introducing sperm to a woman's uterus with a medical instrument. Overall, the success rate is on average under 30 percent, according to the Human Fertilisation & Embryology Authority of the United Kingdom. In vitro fertilization can be more effective, but it's a complicated and expensive process. It requires removing eggs from a woman's ovaries with a needle, fertilizing them outside the body and then transferring the embryos to her uterus or a surrogate's a few days later. Each step comes with a risk for failure. Mariana Medina-Sánchez, Lukas Schwarz, Oliver G. Schmidt and colleagues from the Institute for Integrative Nanosciences at IFW Dresden in Germany wanted to see if they could come up with a better option than the existing methods. Building on previous work on micromotors, the researchers constructed tiny metal helices just large enough to fit around the tail of a sperm. Their movements can be controlled by a rotating magnetic field. Lab testing showed that the motors can be directed to slip around a sperm cell, drive it to an egg for potential fertilization and then release it. The researchers say that although much more work needs to be done before their technique can reach clinical testing, the success of their initial demonstration is a promising start. About American Chemical Society The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 158,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio. For more information, please click Contacts: Michael Bernstein 202-872-6042 Mariana Medina-Sánchez, Ph.D. Institute for Integrative Nanosciences IFW Dresden Dresden, Germany or Lukas Schwarz, M.Sc. Institute for Integrative Nanosciences IFW Dresden Dresden, Germany or Oliver G. Schmidt, Ph.D. Institute for Integrative Nanosciences IFW Dresden Dresden, Germany http://www.ifw-dresden.de/de/institute/iin If you have a comment, please us. Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.
A National Survey of Family Growth found that 7.5 percent of sexually experienced men under the age of 45 have seen a fertility doctor. That percentage correlates to between 3.3 and 4.7 million men. Of those men, around 17 percent were found to be infertile. There are a myriad of factors that can contribute to male infertility, from medical conditions to environmental toxins. And one of the outcomes is low sperm motility. Researchers from the Institute for Integrative Nanosciences at IFW Dresden believe they’ve come up with a method to help improve a slow-swimming sperm’s chance of fertilizing an egg. And it involves micromotors. In a video published by the American Chemical Society, the researchers show how tiny metal helices—just large enough to fit around the tail of a sperm—can bolster their swimming. The helices movements are controlled via a rotating magnetic field, which helps drive the sperm into an egg. While the work is still in its nascent stages, the researchers believe the success of the initial experiment is promising for the future. The researchers believe the burgeoning technique may be an alternative to artificial insemination, or in vitro fertilization. According to the U.K.’s Human Fertilisation and Embryology Authority, artificial insemination has an average success rate under 30 percent. In vitro fertilization—which involves removing the egg from a woman’s ovaries, fertilizing it outside the body, then placing it in either the woman’s or a surrogate’s uterus—varies in success depending on the age of the woman. According to the Centers for Disease Control and Prevention, 40 percent of woman under age 35 successfully saw a live birth after in vitro fertilization. The percentage declines as the age increases. The researchers published their findings in Nano Letters.
Fomin V.M.,Institute for Integrative Nanosciences |
Rezaev R.O.,Institute for Integrative Nanosciences |
Rezaev R.O.,Tomsk Polytechnic University |
Schmidt O.G.,Institute for Integrative Nanosciences |
Schmidt O.G.,TU Chemnitz
Nano Letters | Year: 2012
As shown theoretically, geometry determines the dynamics of vortices in the presence of transport currents in open superconductor micro- and nanotubes subject to a magnetic field orthogonal to the axis. In low magnetic fields, vortices nucleate periodically at one edge of the tube, subsequently move along the tube under the action of the Lorentz force and denucleate at the opposite edge of the tube. In high magnetic fields, vortices pass along rows closest to the slit. Intervortex correlations lead to an attraction between vortices moving at opposite sides of a tube. Open superconductor nanotubes provide a tunable generator of superconducting vortices for fluxon-based quantum computing. © 2012 American Chemical Society.
Pylypovskyi O.V.,Taras Shevchenko National University |
Kravchuk V.P.,NASU Bogolyubov Institute for Theoretical Physics |
Sheka D.D.,Taras Shevchenko National University |
Makarov D.,Institute for Integrative Nanosciences |
And 2 more authors.
Physical Review Letters | Year: 2015
We show that the interaction of the magnetic subsystem of a curved magnet with the magnet curvature results in the coupling of a topologically nontrivial magnetization pattern and topology of the object. The mechanism of this coupling is explored and illustrated by an example of a ferromagnetic Möbius ring, where a topologically induced domain wall appears as a ground state in the case of strong easy-normal anisotropy. For the Möbius geometry, the curvilinear form of the exchange interaction produces an additional effective Dzyaloshinskii-like term which leads to the coupling of the magnetochirality of the domain wall and chirality of the Möbius ring. Two types of domain walls are found, transversal and longitudinal, which are oriented across and along the Möbius ring, respectively. In both cases, the effect of magnetochirality symmetry breaking is established. The dependence of the ground state of the Möbius ring on its geometrical parameters and on the value of the easy-normal anisotropy is explored numerically. © 2015, American Physical Society. All rights reserved.