5 research outputs found
Reduction of coherent betatron oscillations in a muon g-2 storage ring experiment using RF fields
This work demonstrates that two systematic errors, coherent betatron
oscillations (CBO) and muon losses can be reduced through application of radio
frequency (RF) electric fields, which ultimately increases the sensitivity of
the muon experiments. As the ensemble of polarized muons goes around a
weak focusing storage ring, their spin precesses, and when they decay through
the weak interaction, , the decay
positrons are detected by electromagnetic calorimeters. In addition to the
expected exponential decay in the positron time spectrum, the weak decay
asymmetry causes a modulation in the number of positrons in a selected energy
range at the difference frequency between the spin and cyclotron frequencies,
. This frequency is directly proportional to the magnetic
anomaly , where is the g-factor of the muon, which is
slightly greater than 2. The detector acceptance depends on the radial position
of the muon decay, so the CBO of the muon bunch following injection into the
storage ring modulate the measured muon signal with the frequency
. In addition, the muon populations at the edge of the beam
hit the walls of the vacuum chamber before decaying, which also affects the
signal. Thus, reduction of CBO and unwanted muon loss increases the
measurement sensitivity. Numerical and experimental studies with RF electric
fields yield more than a magnitude reduction of the CBO, with muon losses
comparable to the conventional method.Comment: 14 pages, 25 figure
Distance-mediated plasmonic dimers for reusable colorimetric switches : a measurable peak shift of more than 60 nm
The first reconfigurable colorimetric DNA switches based on target DNA binding are reported. This DNA binding actuates a change in the interparticle distance between gold nanoparticle dimers. A significant spectral shift of 68 nm is achievable from on-off switching. The reconfigurability is possible owing to thiol and EDC-imidazole coupling which anchors the DNA linkers to the nanoparticles. The huge spectral shift allows the unaided eye to observe single target biomolecular binding event in real time under a darkfield microscope. The limit-of-detection for target molecules in PBS and human serum are 10−13 M and 10−11 M respectively. An improved fabrication strategy via asymmetric functionalization is also described, assisted by solid phase synthesis which minimizes the formation of trimers and multimers
Nanotechnology in Corneal Neovascularization Therapy—A Review
Nanotechnology is an up-and-coming branch of science that studies and designs materials with at least one dimension sized from 1–100 nm. These nanomaterials have unique functions at the cellular, atomic, and molecular levels.(1) The term “nanotechnology” was first coined in 1974.(2) Since then, it has evolved dramatically and now consists of distinct and independent scientific fields. Nanotechnology is a highly studied topic of interest, as nanoparticles can be applied to various fields ranging from medicine and pharmacology, to chemistry and agriculture, to environmental science and consumer goods.(3) The rapidly evolving field of nanomedicine incorporates nanotechnology with medical applications, seeking to give rise to new diagnostic means, treatments, and tools. Over the past two decades, numerous studies that underscore the successful fusion of nanotechnology with novel medical applications have emerged. This has given rise to promising new therapies for a variety of diseases, especially cancer. It is becoming abundantly clear that nanotechnology has found a place in the medical field by providing new and more efficient ways to deliver treatment. Ophthalmology can also stand to benefit significantly from the advances in nanotechnology research. As it relates to the eye, research in the nanomedicine field has been particularly focused on developing various treatments to prevent and/or reduce corneal neovascularization among other ophthalmologic disorders. This review article aims to provide an overview of corneal neovascularization, currently available treatments, and where nanotechnology comes into play