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Recent paleomagnetic studies have constrained the strength and longevity of the magnetic field generated by the solar nebula, which has broad implications for the early evolution of the solar system. Paleomagnetic evidence was recorded by nanoscale iron inclusions in olivine crystals in the Semarkona LL 3.0 chondrite. These dusty olivines have been shown to be credible carriers of ancient magnetic remanence. The small scale of the iron inclusions presents several challenges for defining their fundamental magnetic properties. Here we present the first correlative study of the response of these magnetic structures under applied laboratory fields. Results show that the majority of particles are in a single-vortex state and exhibit stable magnetic behavior in applied fields up to 200 mT. Experimental observations using Lorentz microscopy and magnetic transmission X-ray microscopy are shown to compare well with the results of finite-element micromagnetic simulations derived from 3-D models of the particles obtained using electron tomography. This correlative approach may be used to characterize the fundamental magnetic behavior of many terrestrial and extraterrestrial paleomagnetic carriers in the single-vortex to multivortex size range, which represent the vast majority of stable magnetic carriers in rocks and meteorites.

Ryo Takahashi, Sakiko Isojima, Masayu Umemura, Yoko Miura, Nao Oguro, Syo Ishii, Shinya Seki, Takahiro Tokunaga, Hiroyuki Tsukamoto, Hidekazu Furuya, Ryo Yanai, Tsuyoshi KasamaDivision of Rheumatology, Department of Medicine, Showa University School of Medicine,Tokyo, Japan Abstract: Anticyclic citrullinated protein antibody (ACPA) is known as an important indicator for diagnosis of rheumatoid arthritis (RA). Our aim was to examine the relationship between the serum ACPA titer at baseline and responsiveness to biological agents (antagonists of either tumor necrosis factor or interleukin 6) in patients with RA. ACPA was measured using second-generation chemiluminescent enzyme immunoassay. Disease activity was assessed using disease activity scores 28. Fifty-seven RA patients with biological agents were enrolled, and the median ACPA titer at baseline was 110.0 U/mL. The median ACPA titer was 23.3 U/mL and 183.0 U/mL in the good and moderate response groups, respectively, which were significantly lower than in the no response group (404.0 U/mL). In addition, 69.2% and 26.9% of patients with low (

Hidekazu Furuya,1 Tsuyoshi Kasama,1 Takeo Isozaki,1,2 Masayu Umemura,1 Kumiko Otsuka,1 Sakiko Isojima,1 Hiroyuki Tsukamoto,1 TakehiroTokunaga,1 Ryo Yanai,1 Ryo Takahashi11Division of Rheumatology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan; 2Department of Rheumatology,University of Michigan Medical School, Ann Arbor, MI, USAAbstract: Rheumatoid arthritis (RA) is a significant cause of work disability and job loss. The resulting economic burden experienced by patients has received considerable research attention. This research assesses the effect of tumor necrosis factor (TNF) antagonists (infliximab, etanercept) on the ability of RA patients living in Japan to work and participate in society. A total of 42 patients with active RA were enrolled and given biological therapy for 12 months (mo). Of these patients, 14 were employed full-time, 6 were employed part-time, and 22 were not employed. Twenty-six patients were given infliximab, and sixteen were given etanercept. The amount of domestic labor performed before the biologics served as a baseline and was assigned a value of 0%. After treatment with biologics, the productivity was evaluated using the visual analog scale (VAS; −100 to +100 mm). The administration of TNF antagonists to RA patients who exhibited an insufficient response to medical treatment significantly improved the Disease Activity Score 28 (DAS 28) after both 6 mo and 12 mo (P < 0.0001). A significant correlation was found between the improvement in their DAS 28 and improvements in their work situation (Productivity VAS) (P < 0.05). Of particular interest is the significant correlation between the values of baseline mHAQ and the percent changes of Productivity VAS that was observed after 6 mo and 12 mo (P < 0.05). Our findings indicate that medical treatment of RA with TNF antagonists improves the patients' ability to perform their jobs and housekeeping. Because loss of productivity is an important contributor to the indirect costs of RA, our findings are relevant for the pharmacoeconomic assessment of treatments.Keywords: rheumatoid arthritis, infliximab, etanercept, productivity, DAS28, mHAQ

Large area square arrays of circular cobalt dots, nominally 100 nm in diameter and 20 nm in thickness are patterned using interference lithography and magnetic remanent states are measured using off-axis electron holography in the transmission electron microscope. The results reveal that the dots are mostly single domain, although vortex states and multidomain configurations are occasionally observed.

Doping mechanisms of Mn in GaAs nanowires (NWs) that have been grown self-catalytically at 600 °C by molecular beam epitaxy (MBE) are investigated using advanced electron microscopy techniques and atom probe tomography. Mn is found to be incorporated primarily in the form of non-magnetic tetragonal Ga0.82Mn0.18 nanocrystals in Ga catalyst droplets at the ends of the NWs, while trace amounts of Mn (22±4 at. ppm) are also distributed randomly in the NW bodies without forming clusters or precipitates. The nanocrystals are likely to form after switching off the reaction in the MBE chamber, since they are partially embedded in neck regions of the NWs. The Ga0.82Mn0.18 nanocrystals and the low Mn concentration in the NW bodies are insufficient to induce a ferromagnetic phase transition, suggesting that it is difficult to have high Mn contents in GaAs even in 1-D NW growth via the vapor-liquid-solid process. [ABSTRACT FROM AUTHOR]

We apply off-axis electron holography and Lorentz microscopy in the transmission electron microscope to map the electric field generated by a sharp biased metallic tip. A combination of experimental data and modelling provides quantitative information about the potential and the field around the tip. Close to the tip apex, we measure a maximum field intensity of 82 MV/m, corresponding to a field k factor of 2.5, in excellent agreement with theory. In order to verify the validity of the measurements, we use the inferred charge density distribution in the tip region to generate simulated phase maps and Fresnel (out-of-focus) images for comparison with experimental measurements. While the overall agreement is excellent, the simulations also highlight the presence of an unexpected astigmatic contribution to the intensity in a highly defocused Fresnel image, which is thought to result from the geometry of the applied field. [ABSTRACT FROM AUTHOR]

We have used electron holography to investigate the local magnetic behavior of isolated ferromagnetic nanowires (NWs) in their remanent states. The NWs consisted of periodic magnetic layers of soft, high-saturation magnetization CoFeB alloys, and non-magnetic layers of Cu. All NWs were fabricated by pulsed-potential electrodeposition in nanoporous alumina membranes. The NW composition and layer thicknesses were measured using scanning transmission electron microscopy and energy dispersive spectroscopy. The magnetization of individual NWs depended upon the thicknesses of the layers and the direction of an external magnetic field, which had been applied in situ. When the CoFeB was thicker than the diameter (50 nm), magnetization was axial for all external field directions, while thinner layers could be randomized via a perpendicular field. In some cases, magnetization inside the wire was detected at an angle with respect to the axis of the wires. In thinner Cu/CoFeB (<10 nm each) multilayer, magnetic field vortices were detected, associated with opposing magnetization in neighbouring layers. The measured crystallinity, compositions, and layer thicknesses of individual NWs were found to be significantly different from those predicted from calibration growths based on uniform composition NWs. In particular, a significant fraction of Cu (up to 50 at. %) was present in the CoFeB layers such that the measured magnetic induction was lower than expected. These results will be used to better understand previously measured effective anisotropy fields of similar NW arrays. [ABSTRACT FROM AUTHOR]

We have investigated the interaction between Pd and Ce in a (0.47 wt %) CeOx–Pd(1 wt %)/α-Al2O3 catalyst that is used in the reforming reaction of CH4 with CO2. The freshly reduced catalyst was characterized by various electron microscopy techniques, such as elemental mapping, Z-contrast imaging, and electron energy-loss spectroscopy to understand the role of Ce on a microscopic scale. The high spatial resolution elemental mapping indicates that CeOx is located in close proximity of the palladium nanoparticles. High-resolution lattice images and energy-loss spectra obtained in the vicinity of the Pd particles show an anisotropic distribution of CeOx crystallites limited to the interface region between Pd and the substrate but not covering the surface of the Pd nanoparticles. Energy-loss near edge fine structure of Pd M edges reveals that the Pd nanoparticles are not oxidized. [ABSTRACT FROM AUTHOR]

Magnetic remanent states in a rectangular array of 75×280-nm2 NiFe/Cu/Co thin-film pseudo-spin-valve elements are studied using off-axis electron holography in the transmission electron microscope (TEM). An approach based on focused ion-beam milling is used to minimize damage to the magnetic properties of the elements during preparation for TEM examination in plan-view geometry. Experimental electron holographic phase images are used to measure the switching fields of the Co and NiFe layers in each of three adjacent elements separately, and comparisons with micromagnetic simulations are used to infer the true magnetic thicknesses and widths of the layers. Demagnetizing fields are included in the discussion of the results, and the possibility that the conclusions may be affected by the procedure used to analyze the holograms is discussed. [ABSTRACT FROM AUTHOR]

Various electron microscopy techniques were employed to examine the interaction between Pd and Ce in a (0.47 wt %) Ce[O.sub.x]-Pd(1 wt %)/[alpha]-[Al.sub.2][O.sub.3] catalyst that is used in the reforming reaction of C[H.sub.4] with C[O.sub.2]. The results provide insight into the location of Ce[O.sub.x] in close proximity of the palladium nanoparticles and the anisotropic distribution of Ce[O.sub.x] crystallites that is limited to the interface region between Pd and the substrate but deos not cover the surface of the Pd nanoparticles.

Magnetization reversal in a chain of permalloy [Fe.sub.0.2][Ni.sub.0.8] spheres, whose diameters of 40-60 nm are large enough to support vortex structures, is investigated using micromagnetic modeling based on the Landau-Liftshitz-Gilbert equations. It is revealed that the results for two spheres are generalized in the description of a chain of n spheres, in which at least [2.sup.n] symmetry states could be selected by the application of inhomogeneous fields.