Search

Background: Percutaneous microwave ablation (pMWA) is a minimally invasive procedure that uses a microwave antenna placed at the tip of a needle to induce lethal tissue heating. It can treat cancer and other diseases with lower morbidity than conventional surgery, but one major limitation is the lack of control over the heating region around the ablation needle. Superparamagnetic iron oxide nanoparticles have the potential to enhance and control pMWA heating due to their ability to absorb microwave energy and their ease of local delivery. Purpose: The purpose of this study is to experimentally quantify the capabilities of FDA‐approved superparamagnetic iron oxide Feraheme nanoparticles (FHNPs) to enhance and control pMWA heating. This study aims to determine the effectiveness of locally injected FHNPs in increasing the maximum temperature during pMWA and to investigate the ability of FHNPs to create a controlled ablation zone around the pMWA needle. Methods: PMWA was performed using a clinical ablation system at 915 MHz in ex‐vivo porcine liver tissues. Prior to ablation, 50 uL 5 mg/mL FHNP injections were made on one side of the pMWA needle via a 23‐gauge needle. Local temperatures at the FHNP injection site were directly compared to equidistant control sites without FHNP. First, temperatures were compared using directly inserted thermocouples. Next, temperatures were measured non‐invasively using magnetic resonance thermometry (MRT), which enabled comprehensive four‐dimensional (volumetric and temporal) assessment of heating effects relative to nanoparticle distribution, which was quantified using dual‐echo ultrashort echo time (UTE) subtraction MR imaging. Maximum heating within FHNP‐exposed tissues versus control tissues were compared at multiple pMWA energy delivery settings. The ability to generate a controlled asymmetric ablation zone using multiple FHNP injections was also tested. Finally, intra‐procedural MRT‐derived heat maps were correlated with gold standard gross pathology using Dice similarity analysis. Results: Maximum temperatures at the FHNP injection site were significantly higher than control (without FHNP) sites when measured using direct thermocouples (93.1 ± 6.0°C vs. 57.2 ± 8.1°C, p = 0.002) and using non‐invasive MRT (115.6 ± 13.4°C vs. 49.0 ± 10.6°C, p = 0.02). Temperature difference between FHNP‐exposed and control sites correlated with total energy deposition: 66.6 ± 17.6°C, 58.1 ± 8.5°C, and 20.8 ± 9.2°C at high (17.5 ± 2.2 kJ), medium (13.6 ± 1.8 kJ), and low (8.8 ± 1.1 kJ) energies, respectively (all pairwise p < 0.05). Each FHNP injection resulted in a nanoparticle distribution within 0.9 ± 0.2 cm radially of the injection site and a local lethal heating zone confined to within 1.1 ± 0.4 cm radially of the injection epicenter. Multiple injections enabled a controllable, asymmetric ablation zone to be generated around the ablation needle, with maximal ablation radius on the FHNP injection side of 1.6 ± 0.2 cm compared to 0.7 ± 0.2 cm on the non‐FHNP side (p = 0.02). MRT intra‐procedural predicted ablation zone correlated strongly with post procedure gold‐standard gross pathology assessment (Dice similarity 0.9). Conclusions: Locally injected FHNPs significantly enhanced pMWA heating in liver tissues, and were able to control the ablation zone shape around a pMWA needle. MRI and MRT allowed volumetric real‐time visualization of both FHNP distribution and FHNP‐enhanced pMWA heating that was useful for intra‐procedural monitoring. This work strongly supports further development of a FHNP‐enhanced pMWA paradigm; as all individual components of this approach are approved for patient use, there is low barrier for clinical translation. [ABSTRACT FROM AUTHOR]

"The George Lopez Show" is the first successful television show with a Latino in a leading role that features Hispanic material since Freddie Prinze's thirty-year-old sitcom, "Chico and the Man." This study seeks to assess how Latinos are presented on "The George Lopez Show." A content analysis reveals that the show perpetuates some of the stereotypes about Hispanics that are prevalent in the wider society. The stereotypes, however, are relatively subtle. Because the stereotypes are not overtly demeaning, the 14 percent of the Latinos who watch the show may not be offended by the negative representation. At the same time, "The George Lopez Show" challenges some of the stereotypes held by the wider society, prompting Anglos to view Hispanics differently and promoting pride among Latino viewers. Added depth to this conclusion was provided by focus group responses by Latinos and Anglos/blacks. This study finds that the show both perpetuates certain stereotypes while at the same time challenging them. This paper examines how the show manages to do both. In the end, however, "The George Lopez Show" fosters a positive image of Latinos substantially more than a negative one. The paper concludes by appraising the effect the conflicting images found on the show may have for regular viewers. (Contains 11 notes.)

Focus groups of 43 parents in Nashville elicited opinions of their children's education. They perceived local schools to be okay, but thought education overall was in trouble. Collectively, a lack of parental involvement was a serious problem. (SK)

The Malphusian fallacy forecast of doom is predicted on one change, ignoring the other change. An effort is made to examine the basis of these fallacy and prophecies of doom that surround social security as the boomers retire, failing to examine these changes spreads fear and ill informed social policy.

Oxo-bridged, oligomeric Fe(III) complexes are assumed to be steadied by a novel ditopic receptor ligand dtnp-OH, which is prepared. A tetranuclear iron(III) complex without any carboxylate ligands is steadied by the ligand, immaterial of the occurrence of a carboxylate source. An Fe(II) source preceding air oxidation can serve as a pathway for the preparation of a similar Fe(III) complex. The conformation properties of the derived tetranuclear iron(III) complex reveal the presence of an Fe4O6 center with a structure resembling adamantane due to the presence of iron atoms in the bridgehead locations.

The complex (LFe2O(C5H6O4))2(PF6)4 (L = 1,4-bis(1,4,7-triaza-1- cyclononyl)butane) was synthesized by the reaction of glutaric acid and LFe2Cl6 in KPF6. The complex consisted of two (mu-oxo)-bis(mu-carboxylato) diiron cores linked by 1,4,7-triazacyclononane from L and two glutarate ligands. Electrochemical studies showed a significant difference of the complex from ((LFe2O(O2CCH3)2)2)(PF6)4. Nearly similar magnetic susceptibility data were obtained for the two complexes.

Reviews unique environmental features of the sixties that precipitated the growth of Alternative Youth Programs. Internal characteristics of Alternative Youth Programs are surveyed to identify features of counterculture ideology that were assimilated into the early structure of these organizations and contributed to their early success. (Author/BEF)

The imaging and dynamical measurements using a [super 3]He nuclear magnetic resonance force microscopy probe. The proton magnetic moments have undergone cyclic adiabatic inversions (CAIs) under the effect of a frequency-modulated rf field.

New bimetallic copper(I) and copper(II) complexes of dipyrromethane-derived Schiff base macrocyles are reported. Structural analysis revealed a copper-copper distance of 3.47 angstrom, while SQUID magnetic susceptibility data provided evidence for antiferromagnetic coupling between the two metal centers.

The coordination chemistry of the Schiff base polypyrrolic octaaza macrocycle toward late first-row transition metals was investigated. The result illustrates the potential versatility of the generalized oligopyrrole Schiff base switchable ligand approach.

Texture and grain-size effects on the exchange bias in sputtered polycrystalline NiO/NiFe bilayers are discussed. It is consistent with a model that the exchange interaction is caused by the reorientation of the moments with AF layer spins rotating.

Resonant frequency of magnetically capped oscillators to a magnetic field when applied perpendicular to the magnetic film, to magnetic resonance force microscopy is discussed. This work suggests high field magnet-on-oscillator, which can be performed in the perpendicular configuration without significant complications.

High-speed massive imaging of hard disk data is developed by using the spin-stand imaging technique. The developed technique is a potent tool for analyzing hard disk drives including read head characterization.

Surface magnetic imaging structure of Cr(100) films grown on Au(100) film is performed using spin-polarized scanning tunneling spectroscopy. It verifies the topological Af order on the Cr(100) film surface that is subject to the high step density and screw dislocation density.

Songs dealing with illegal drugs have long dotted popular music. It was not until the aftermath of the sixties youth counterculture, however, that drug lyrics became a recurring musical motif. In the decades since, the lyrical treatment of drugs has undergone change. Heroin and cocaine have largely, though not exclusively, been treated antagonistically, with the animosity toward cocaine becoming more pronounced after crack cocaine was introduced in the mid-1980s. Marijuana, on the other hand, has generally been perceived as innocuous, if not positively assessed, and this treatment has crossed the decades into the nineties. In more recent years, however, the positive assessment of marijuana has undergone change, with younger musicians more likely to decry the harm that drags do than older musicians do. This prosocial aspect of contemporary popular music has been largely ignored.

We report imaging and dynamical measurements using a 3He nuclear magnetic resonance force microscopy probe. Relaxation-time measurements and a one-dimensional image were obtained for 1H nuclei in a micron-scale crystal of (NH4)2SO4. The force detection was made possible by a small Permalloy magnet, which supplied a field gradient of 500 T/m. These experiments were performed in the sample-on-oscillator configuration at room temperature, where the oscillator had a resonance frequency of 1.5 kHz and a spring constant of 0.03 N/m. The proton magnetic moments underwent cyclic adiabatic inversions (CAIs) under the influence of a frequency-modulated rf field. Scanning the position of the magnet with respect to the sample provided a micron-scale image with a signal-to-noise ratio of 4.3. A spin nutation signal was also obtained; those data imply a rotating rf field of 14 G. Using a 90°-τ-180°-t-90°-CAI sequence, a spin echo was mapped out, with a full width at half maximum of 8 μs. We also discuss future applications of this instrument toward relaxation measurements of single-crystal MgB2 at low temperatures. [ABSTRACT FROM AUTHOR]