An Isolated Stellar-Mass Black Hole Detected Through Astrometric Microlensing

We report the first unambiguous detection and mass measurement of an isolated stellar-mass black hole (BH). We used the Hubble Space Telescope (HST) to carry out precise astrometry of the source star of the long-duration (t_E ~ 270 days), high-magnification microlensing event MOA-2011-BLG-191/OGLE-2011-BLG-0462, in the direction of the Galactic bulge. HST imaging, conducted at eight epochs over an interval of six years, reveals a clear relativistic astrometric deflection of the background star's apparent position. Ground-based photometry shows a parallactic signature of the effect of the Earth's motion on the microlensing light curve. Combining the HST astrometry with the ground-based light curve and the derived parallax, we obtain a lens mass of 7.1 +/- 1.3 M_Sun and a distance of 1.58 +/- 0.18 kpc. We show that the lens emits no detectable light, which, along with having a mass higher than is possible for a white dwarf or neutron star, confirms its BH nature. Our analysis also provides an absolute proper motion for the BH. The proper motion is offset from the mean motion of Galactic-disk stars at similar distances by an amount corresponding to a transverse space velocity of ~45 km/s, suggesting that the BH received a modest natal 'kick' from its supernova explosion. Previous mass determinations for stellar-mass BHs have come from radial-velocity measurements of Galactic X-ray binaries, and from gravitational radiation emitted by merging BHs in binary systems in external galaxies. Our mass measurement is the first ever for an isolated stellar-mass BH using any technique

Blood Properties and Liver Cell Components in Process of Rat Hepatic Cirrhosis Produced by Low Protein Diets. (B. LIVING SCIENCE)

We conducted to estimate hematological and metabolic changes in the productive process of hepatic cirrhosis. Male Charles-River Crj-CD rats were fed 5% gluten diet, 5% casein diet, 5% wheat-pattern amino acid mixture diet and 20% casein diet as control ad libitum for 29 weeks. After autopsy, hematological and biochemical determinations were performed. Body weight gains of rats on experimental low protein diets were significantly lower than that of the control, showing 82g for LC-group, 12g for W-group and -6g for G-group as compared with 420g of the control group at the 20th experimental week. At the 29th experimental week, rats in W-and G-groups showed significant decreases in RBC counts, hemoglobin contents, hematocrits and serum protein. On the same week, RNA, DNA contents and RNA/DNA ratios in rat liver tissues of W-group and G-group did not differ from those of the control group. For LC-group, however, collagen contents in the liver had a tendency to slightly increase. These biochemical evidences were co-ordinate to histological findings

Fabrication of “Clickable” Polyfluorene Nanowires with High Aspect Ratio as Biological Sensing Platforms

“Clickable” nanowires with well-defined and uniform structures made of conjugated polyfluorene polymers were successfully fabricated by single particle nanofabrication technique (SPNT). Poly[(9,9-dihex-5-yn-1-ylfluorenyl-2,7-diyl)-co-(9,9′-di-noctylfluorenyl- 2,7-diyl)] (F6E8) and poly[(9,9-dihex-5-yn-1-ylfluorenyl- 2,7-diyl)-co-(2,2′-bithiophene)] (F6E2T) underwent an efficient cross-linking reaction upon irradiation, resulting in formation of one-dimensional nanostructures with high and desired aspect ratio reaching up to 200. Alkyne groups on the surface of nanowires were functionalized effectively by click reaction with fluorescent 5- TAMRA-PEG3-azide, which was confirmed by confocal microscopy. Substrates functionalized with the nanowires provide dramatic expansion of “clickable” surface area immobilized directly with TAMRA, and the fluorescence resonance energy transfer (FRET) processes between TAMRA and nanowire backbones are demonstrated as biological sensing platforms

Neopentyl glycol as a scaffold to provide radiohalogenated theranostic pairs of high in vivo stability

The high in vivo stability of 2,2-dihydroxymethyl-3-[18F]fluoropropyl-2-nitroimidazole ([18F]DiFA) prompted us to evaluate neopentyl as a scaffold to prepare a radiotheranostic system with radioiodine and astatine.Three DiFA derivatives with one, two, or without a hydroxyl group were synthesized. While all 125I-labeled compounds remained stable against nucleophilic substitution, only a 125I-labeled neopentyl glycol was stable against cytochrome P450 (CYP)-mediated metabolism and showed high stability against in vivo deiodination. 211At-labeled neopentyl glycol also remained stable against both nucleophilic substitution and CYP-mediated metabolism. 211At labeled neopentyl glycol showed the biodistribution profiles similar to those of its radioiodinated counterpart in contrast to the 125I/211At-labeled benzoate pair. The urine analyses confirmed that 211At-labeled neopentyl glycol was excreted in the urine as a glucuronide conjugate with the absence of free [211At]At-. These findings indicate that neopentyl glycol would constitute a promising scaffold to prepare a radiotheranostic system with radioiodine and 211At

Evaluation of Neopentyl Derivatives as A Scaffold for Astatination and Radioiodination

Astatine-211 (211At) is one of the most promising radionuclides for targeted α therapy of cancers and radioiodine such as iodine-123 is useful radionuclide for diagnosis. Because astatine and iodine are the same group, halogen, the same scaffolds could be used for astatination and radioiodination to prepare radiotheranostics compounds. However, the in vivo instability of 211At-labeling agents such as 211At-benzoate limits the application of 211At to various compounds. To overcome the problem and expand the application of 211At-labeled compounds to radiotheranostics, we developed neopentyl derivatives as a novel scaffold for astatination and radioiodination. The stability and biodistribution of 211At or 125I-labeled neopentyl derivatives were compared with reference compounds radiolabeled with 125I or 211At via a conventional method using benzamide.SNMMI2020 Annual Meetin

Experiment of two frequency heating for production of multiply charged ion at compact ECR ion source.

Several research and developments have been performed at a compact ECR ion source (Kei3) with a fixed magnetic field at HIMAC. The Kei3 is a testing machine for application of Kei series developed for high-energy carbon-ion radiotherapy. It is difficult for Kei3 to produce ions that are heavier than carbon ion because it uses the same magnetic field distribution as the Kei series. In order to improve the beam current of multiply charged ions such as the neon and the argon, the two microwave frequency heating method was tested in Kei3. Microwaves are introduced from the vacuum box on the upstream side of the plasma chamber through the rectangular waveguide of the WR-90. A traveling wave tube (TWT) amplifier made by NEC (LD79X75A1) is used as the microwave source. The frequency band is 9.75-10.25 GHz and the maximum output power is 750 W. The WR-75 waveguide is also introduced from the upper part of the upstream vacuum box and installed on top of the existing WR-90 waveguide. A TWT amplifier manufactured by Xicom (XTRD-300IJ) was used as a microwave source for the two frequency heating. The frequency band is 10-18 GHz and the maximum output power is 300 W.A beam test with oxygen, neon, and argon was performed in order to confirm the effect of two microwave frequency heating. In this test, we focused on O6+, Ne7+, and Ar9+ ions. We checked the microwave frequency at the XTRD-300IJ, dependence of the microwave power at the LD79X75A1 and charge state distributions of O, Ne and Ar

Proton-3He Elastic Scattering at Intermediate Energies

We present a precise measurement of the cross section, proton and 3He analyzing powers, and spin correlation coefficient Cy,y for the p-3He elastic scattering near 65 MeV, and comparison with rigorous four-nucleon scattering calculations based on realistic nuclear potentials and a model with Δ-isobar excitation. Clear discrepancies are seen in some of the measured observables in the regime around the cross section minimum. Theoretical predictions using scaling relations between the calculated cross section and the 3He binding energy are not successful in reproducing the data. Large sensitivity to the NN potentials and rather small Δ-isobar effects in the calculated cross section are noticed as different features from those in the deuteron-proton elastic scattering. The results obtained above indicate that p-3He scattering at intermediate energies is an excellent tool to explore the nuclear interactions not accessible by the three-nucleon scattering