An optimization method for designing SENSE imaging RF coil arrays

An optimization method in RF coil array design for SENSE imaging is described. Using this method the optimized RF coil geometries can be calculated numerically given the required SENSE imaging performance. Although this method can be applied to optimize the RF coil arrays for both 1D and 2D SENSE imaging, to demonstrate the potential applications of this method, we designed RF coil arrays for 2D SENSE imaging and compared their performance by simulation. An optimized 4-channel receive-only RF coil array designed for 2D SENSE imaging was implemented and tested to demonstrate the feasibility of the proposed technique. Imaging results showed reasonable agreement with the simulations, thus the method can be applied to RF coil array designs for SENSE imaging when optimum imaging performance is desired.     

Effects of gamma irradiation on morphological changes and biological responses in plants

This review discusses the morphological changes and biological responses of plants irradiated with gamma rays. Seedlings exposed to relatively low doses of gamma rays (1-5 Gy) developed normally, while the growth of plants irradiated with a high dose gamma ray (50 Gy) was significantly inhibited. Based on TEM observations, chloroplasts were extremely sensitive to gamma irradiation compared to other cell organelles, particularly thylakoids being heavily swollen. In addition, some portions of the mitochondria and endoplasmic reticulum were structurally altered, for example, distortion and swelling. The cerium perhydroxide deposition, as a maker for H(2)O(2) deposition, was typically manifest on the plasma membranes and cell walls of the tissues from both the control and irradiated plants. However, the intensities of cerium perhydroxide deposits (CPDs) were remarkably increased in the plasma membranes and cell walls of pumpkin tissues such as petiole, cotyledon, hypocotyl and especially leaf after gamma irradiation. These observations are in good agreement with the results of H(2)O(2) content in all tissues. The immuno-localization analysis for peroxidase (POD) on the tissues from pumpkin plant showed the same pattern between the control and irradiated plants, but the density of gold particles as indication of POD localization was significantly increased on the cell corner middle lamellae of parenchyma cells, especially in the petiole after gamma irradiation. However, accumulation and localization of H(2)O(2) and POD in vessels were not significantly different between both plants. The accumulation and localization of both H(2)O(2) and POD were differentially affected by gamma irradiation depending on the different tissue types. The deposition of both H(2)O(2) and POD in parenchyma cells appeared much higher than in vessels, suggesting that the former is more sensitive than the latter against gamma rays.     

Medical radioisotope 89Zr production with RFT-30 cyclotron

Journal of Radioanalytical and Nuclear Chemistry - 89Zr is an emerging radionuclide with promising application in nuclear medicine for the non-invasive diagnosis of various cancers with PET...     

Strong Asymptotics of the Orthogonal Polynomials with Respect to a Measure Supported on the Plane

We consider the orthogonal polynomials with respect to the measure over the whole complex plane. We obtain the strong asymptotic of the orthogonal polynomials in the complex plane and the location of their zeros in a scaling limit where n grows to infinity with N . The asymptotics are described in terms of three (probability) measures associated with the problem. The first measure is the limit of the counting measure of zeros of the polynomials, which is captured by the g‐function much in the spirit of ordinary orthogonal polynomials on the real line. The second measure is the equilibrium measure that minimizes a certain logarithmic potential energy, supported on a region K of the complex plane. The third measure is the harmonic measure of K ^c with a pole at ∞ . This appears as the limit of the probability measure given (up to the normalization constant) by the squared modulus of the n^th orthogonal polynomial times the orthogonality measure, i.e., The compact region K that is the support of the second measure undergoes a topological transition under the variation of the parameter in a double scaling limit near the critical point given by we observe the Hastings‐McLeod solution to Painlevé II in the asymptotics of the orthogonal polynomials. © 2014 Wiley Periodicals, Inc.     

Synthesis of a Zn-salen resorcinarene-based cavitand and its fluorescence response to nitro compounds

The synthesis, spectroscopic characterisation, conformational switching and fluorescence quenching efficiency of a resorcinarene-based cavitand containing Zn-salen (Zn-Cav) are reported. Synthesis of Zn-Cav was accomplished by the condensation of a quinoxaline derivatised with Zn-salen and a resorcinarene-based cavitand containing three quinoxalines. ¹H NMR spectroscopy confirmed that in DMSO, chloroform and acetone Zn-Cav resides in the vase conformation. The molecular geometry of Zn-Cav selectively changes from vase to kite under acidic conditions. Detection by fluorescence quenching of nitro-containing molecules, such as 4-nitrotoluene, 2,4-dinitrotoluene and 2,3-dimethyl-2,3-dinitrobutane was explored by spectrofluorimetry. It was found that the fluorescence of Zn-Cav is efficiently quenched by nitroaromatic compounds.     

Knockdown of 14-3-3ζ enhances radiosensitivity and radio-induced apoptosis in CD133+ liver cancer stem cells

14-3-3ζ is related to many cancer survival cellular processes. In a previous study, we showed that silencing 14-3-3ζ decreases the resistance of hepatocellular carcinoma (HCC) to chemotherapy. In this study, we investigated whether silencing 14-3-3ζ affects the radioresistance of cancer stem-like cells (CSCs) in HCC. Knockdown of 14-3-3ζ decreased cell viability and the number of spheres by reducing radioresistance in CSCs after γ-irradiation (IR). Furthermore, the levels of pro-apoptotic proteins were upregulated in CSCs via silencing 14-3-3ζ after IR. These results suggest that 14-3-3ζ knockdown enhances radio-induced apoptosis by reducing radioresistance in liver CSCs.     

Using Simple Spray Pyrolysis to Prepare Yolk–Shell‐Structured ZnO–Mn3O4 Systems with the Optimum Composition for Superior Electrochemical Properties

A spray‐pyrolysis process is introduced as an effective tool for the preparation of yolk–shell‐structured materials with electrochemical properties suitable for anode materials in Li‐ion batteries (LIBs). Yolk–shell‐structured ZnO–Mn₃O₄ systems with various molar ratios of the Zn and Mn components are prepared. The yolk–shell‐structured ZnO–Mn₃O₄ powders with a molar ratio of 1:1 of the Zn and Mn components are shown to have high capacities and good cycling performances.     

Highly Stable,Water‐Dispersible Metal‐Nanoparticle‐Decorated Polymer Nanocapsules and Their Catalytic Applications

A facile synthesis of highly stable, water‐dispersible metal‐nanoparticle‐decorated polymer nanocapsules (M@CB‐PNs: M=Pd, Au, and Pt) was achieved by a simple two‐step process employing a polymer nanocapsule (CB‐PN) made of cucurbit[6]uril (CB[6]) and metal salts. The CB‐PN serves as a versatile platform where various metal nanoparticles with a controlled size can be introduced on the surface and stabilized to prepare new water‐dispersible nanostructures useful for many applications. The Pd nanoparticles on CB‐PN exhibit high stability and dispersibility in water as well as excellent catalytic activity and recyclability in carbon–carbon and carbon–nitrogen bond‐forming reactions in aqueous medium suggesting potential applications as a green catalyst.     

Blue Luminescence of Dendrimer‐Encapsulated Gold Nanoclusters

Direct evidence for the blue luminescence of gold nanoclusters encapsulated inside hydroxyl‐terminated polyamidoamine (PAMAM) dendrimers was provided by spectroscopic studies as well as by theoretical calculations. Steady‐state and time‐resolved spectroscopic studies showed that the luminescence of the gold nanoclusters consisted largely of two electronic transitions. Theoretical calculations indicate that the two transitions are attributed to the different sizes of the gold nanoclusters (Au₈ and Au₁₃). The luminescence of the gold nanoclusters was clearly distinguished from that of the dendrimers.