9 research outputs found
Bott--Kitaev periodic table and index theory
We consider topological insulators and superconductors with discrete
symmetries and clarify the relevant index theory behind the periodic table
proposed by Kitaev.
An effective Hamiltonian determines the analytical index, which can be
computed by a topological index. We focus on the spatial dimensions one, two
and three, and only consider the bulk theory.
In two dimensions, the -valued invariants are given by the first
Chern number. Meanwhile, -valued invariants can be computed by
the odd topological index and its variations.
The Bott-Kitaev periodic table is well-known in the physics literature, we
organize the topological invariants in the framework of KR-theory.Comment: 37 page
Dual optimization method of radiofrequency and quasistatic field simulations for reduction of eddy currents generated on 7T radiofrequency coil shielding.
PURPOSE: To optimize the design of radiofrequency (RF) shielding of transmit coils at 7T and reduce eddy currents generated on the RF shielding when imaging with rapid gradient waveforms.
METHODS: One set of a four-element, 2 Ă— 2 Tic-Tac-Toe head coil structure was selected and constructed to study eddy currents on the RF coil shielding. The generated eddy currents were quantitatively studied in the time and frequency domains. The RF characteristics were studied using the finite difference time domain method. Five different kinds of RF shielding were tested on a 7T MRI scanner with phantoms and in vivo human subjects.
RESULTS: The eddy current simulation method was verified by the measurement results. Eddy currents induced by solid/intact and simple-structured slotted RF shielding significantly distorted the gradient fields. Echo-planar images, B1+ maps, and S matrix measurements verified that the proposed slot pattern suppressed the eddy currents while maintaining the RF characteristics of the transmit coil.
CONCLUSION: The presented dual-optimization method could be used to design RF shielding and reduce the gradient field-induced eddy currents while maintaining the RF characteristics of the transmit coil
Recent developments in receptor tyrosine kinases targeted anticancer therapy
Novel concepts and understanding of receptors lead to discoveries and optimization of many small molecules and antibodies as anti-cancerous drugs. Receptor tyrosine kinases (RTKs) are such a promising class of receptors under the investigation in past three decades. RTKs are one of the essential mediators of cell signaling mechanism for various cellular processes. Transformations such as overexpression, dysregulation, or mutations of RTKs may result into malignancy, and thus are an important target for anticancer therapy. Numerous subfamilies of RTKs, such as epidermal growth factor receptor, vascular endothelial growth factor receptor, fibroblast growth factor receptors, insulin-like growth factor receptor, and hepatocyte growth factor receptor, have been being investigated in recent years as target for anticancer therapy. The present review focuses several small molecules drugs as well as monoclonal antibodies targeting aforesaid subfamilies either approved or under investigation to treat the various cancers
Correction: Design and fabrication of a realistic anthropomorphic heterogeneous head phantom for MR purposes.
[This corrects the article DOI: 10.1371/journal.pone.0183168.]
Quantitative DTI track analysis values for forearm nerves as shown in Fig 7, [FA: Fiber Anisotropy, ADC: Apparent diffusion coefficient, Ax: Axial/Longitudinal, Diff: Diffusivity, sd: standard deviation, and Rad: Radial].
<p>Quantitative DTI track analysis values for forearm nerves as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g007" target="_blank">Fig 7</a>, [FA: Fiber Anisotropy, ADC: Apparent diffusion coefficient, Ax: Axial/Longitudinal, Diff: Diffusivity, sd: standard deviation, and Rad: Radial].</p
3T/7T MRI Analysis [Image Quality Scale: 1-nondiagnostic, 2- poor, 3-fair, 4-good and 5-excellent; Artifacts scale: 1-absent, 2-present but not affecting anatomic detail and 3-present and severely affecting image interpretation].
<p>3T/7T MRI Analysis [Image Quality Scale: 1-nondiagnostic, 2- poor, 3-fair, 4-good and 5-excellent; Artifacts scale: 1-absent, 2-present but not affecting anatomic detail and 3-present and severely affecting image interpretation].</p
7T and 3T T1VIBE, T2 DESS and T2* SWI forearm protocols for HR: Higher and LR: Lower resolution sequences.
<p>These sequences cover Figs <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g001" target="_blank">1</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g002" target="_blank">2</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g003" target="_blank">3</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g004" target="_blank">4</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175629#pone.0175629.g006" target="_blank">6</a>.</p
Microwave-Assisted Solvent-Free Rapid Synthesis of 4-Methyl Coumarin Derivatives by Using Silica functionalized-SO 3
Magnetically Aligned Nanorods in Alginate Capsules (MANiACs): Soft Matter Tumbling Robots for Manipulation and Drug Delivery
Soft, untethered microrobots composed of biocompatible materials for completing micromanipulation and drug delivery tasks in lab-on-a-chip and medical scenarios are currently being developed. Alginate holds significant potential in medical microrobotics due to its biocompatibility, biodegradability, and drug encapsulation capabilities. Here, we describe the synthesis of MANiACs—Magnetically Aligned Nanorods in Alginate Capsules—for use as untethered microrobotic surface tumblers, demonstrating magnetically guided lateral tumbling via rotating magnetic fields. MANiAC translation is demonstrated on tissue surfaces as well as inclined slopes. These alginate microrobots are capable of manipulating objects over millimeter-scale distances. Finally, we demonstrate payload release capabilities of MANiACs during translational tumbling motion