Different expression of Tn and sialyl-Tn antigens between normal and diseased human gastric epithelial cells.

Thomsen-Friedenreich antigen (T antigen) has been supposed to be a cancer-specific carbohydrate antigen. We have previously shown that one third of the Japanese population normally expressed T antigen in gastric surface epithelia and the other two thirds expressed fucosyl-T antigen. Their sialylation and blocked-synthesis were associated with diseased conditions. In the present study, we studied gastric surface epithelial expression of monosaccharide antigen Tn, i.e., a precursor of T antigen, and sialyl-Tn. Normal fundic and pyloric epithelia, respectively, expressed Tn supranucleally and cytoplasmically, but did not express sialyl-Tn. In the intestinal metaplasias and intestinal-type adenomas, goblet cells expressed sialyl-Tn in their vacuoles, and absorptive cells expressed Tn apically. In gastric-type adenomas, Tn, but not sialyl-Tn, was detected. Intestinal-type cancers expressed Tn and sialyl-Tn more often than the diffuse-type cancers. Five cancers did not express Tn, sialyl-Tn, or the T-related antigens. In these, four were diffuse-type cancers. We concluded that: a) normal gastric epithelial cells express Tn; b) metaplastic differentiation is associated with sialylation of Tn and c) expression of Tn and sialyl-Tn is depressed in the gastric cancers. </p

Detection of Soluble Organic Matter in Antarctic Micrometeorites

The Tenth Symposium on Polar Science/Poster presentations: [OA] Antarctic meteorites, Wed. 4 Dec. / Entrance Hall (1st floor), National Institute of Polar Researc

Special issue “Science of solar system materials examined from Hayabusa and future missions (II)”

Six years have passed since the first asteroid sample was returned from the S-type near-Earth asteroid 25143 Itokawa by the JAXA’s Hayabusa mission in 2010 (Yada et al. 2014). Considerable progress has been made in the study of surface regolith materials and the understanding of planetary surface processes such as space weathering (Noguchi et al. 2011), the chronology of Itokawa and its dynamic evolution processes (Nagao et al. 2011; Park et al. 2015), and the thermal alteration undergone in parent bodies (Nakamura T et al. 2011). Discussions of new findings from the Hayabusa-returned samples and from a large collection of meteorites, micrometeorites, and interplanetary dust particles have continued, especially at the annual international Hayabusa symposia of solar system materials (Okada et al. 2015). Progress in sample return science has driven the next stage of exploration. Now, two new sample return missions to primitive, volatile-rich asteroids, JAXA’s Hayabusa2 (Tsuda et al. 2013) and NASA’s OSIRIS-REx (Lauretta et al. 2012), are en route to their target bodies, C-type 162173 Ryugu and B-type 101955 Bennu, respectively. It is our great pleasure to present our second special issue of the journal Earth, Planets and Space, “Science of solar system materials examined from Hayabusa and future missions (II).” This special issue is based on discussions during the Hayabusa 2014 symposium, which featured new results from Hayabusa-returned samples and related studies, but was also open to any scientific results regarding primitive bodies and the early solar system, the results of laboratory experiments and ground-based observations, and reports of new instruments and methods. We will begin with a brief introduction to the missions of the Hayabusa and its successor Hayabusa2. In addition, all six manuscripts published in this special issue are reviewed below

Erratum to: Special issue “Science of solar system materials examined from Hayabusa and future missions (II)”

In the version of this article that was originally published (Okada et al. 2017), there was an error in the title. The phrase “Preface: The Earth, Planets and Space” has been removed from the beginning of the title and the original article has been updated. The publisher apologises for these errors

H, C, and N isotopic compositions of Hayabusa category 3 organic samples

Since isotopic ratios of H, C, and N are sensitive indicators for determining extraterrestrial organics, we have measured these isotopes of Hayabusa category 3 organic samples of RB-QD04-0047-02, RA-QD02-0120, and RB-QD04-0001 with ion imaging using a NanoSIMS ion microprobe. All samples have H, C, and N isotopic compositions that are terrestrial within errors (approximately ±50‰ for H, approximately ±9‰ for C, and approximately ±2‰ for N). None of these samples contain micrometer-sized hot spots with anomalous H, C, and N isotopic compositions, unlike previous isotope data for extraterrestrial organic materials, i.e., insoluble organic matters (IOMs) and nano-globules in chondrites, interplanetary dust particles (IDPs), and cometary dust particles. We, therefore, cannot conclude whether these Hayabusa category 3 samples are terrestrial contaminants or extraterrestrial materials because of the H, C, and N isotopic data. A coordinated study using microanalysis techniques including Fourier transform infrared spectrometry (FT-IR), time-of-flight secondary ion mass spectrometry (ToF-SIMS), NanoSIMS ion microprobe, Raman spectroscopy, X-ray absorption near edge spectroscopy (XANES), and transmission electron microscopy/scanning transmission electron microscopy (TEM/STEM) is required to characterize Hayabusa category 3 samples in more detail for exploring their origin and nature.This research was supported by the JSPS Strategic Fund for Strengthening Leading-edge Research and Development to the JAMSTEC

Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16×12∘ and a spatial resolution of 0.05∘ per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission

The geomorphology, color, and thermal properties of Ryugu: Implications for parent-body processes

The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multi-color images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east/west dichotomy, high boulder abundances across the entire surface, and impact craters. Age estimates from the craters indicate a resurfacing age of ≲ 106 years for the top 1-meter layer. Ryugu is among the darkest known bodies in the Solar System. The high abundance and spectral properties of boulders are consistent with moderately dehydrated materials, analogous to thermally metamorphosed meteorites found on Earth. The general uniformity in color across Ryugu’s surface supports partial dehydration due to internal heating of the asteroid’s parent body.Additional co-authors: N Namiki, S Tanaka, Y Iijima, K Yoshioka, M Hayakawa, Y Cho, M Matsuoka, N Hirata, N Hirata, H Miyamoto, D Domingue, M Hirabayashi, T Nakamura, T Hiroi, T Michikami, P Michel, R-L Ballouz, O S Barnouin, C M Ernst, S E Schröder, H Kikuchi, R Hemmi, G Komatsu, T Fukuhara, M Taguchi, T Arai, H Senshu, H Demura, Y Ogawa, Y Shimaki, T Sekiguchi, T G Müller, T Mizuno, H Noda, K Matsumoto, R Yamada, Y Ishihara, H Ikeda, H Araki, K Yamamoto, S Abe, F Yoshida, A Higuchi, S Sasaki, S Oshigami, S Tsuruta, K Asari, S Tazawa, M Shizugami, J Kimura, T Otsubo, H Yabuta, S Hasegawa, M Ishiguro, S Tachibana, E Palmer, R Gaskell, L Le Corre, R Jaumann, K Otto, N Schmitz, P A Abell, M A Barucci, M E Zolensky, F Vilas, F Thuillet, C Sugimoto, N Takaki, Y Suzuki, H Kamiyoshihara, M Okada, K Nagata, M Fujimoto, M Yoshikawa, Y Yamamoto, K Shirai, R Noguchi, N Ogawa, F Terui, S Kikuchi, T Yamaguchi, Y Oki, Y Takao, H Takeuchi, G Ono, Y Mimasu, K Yoshikawa, T Takahashi, Y Takei, A Fujii, C Hirose, S Nakazawa, S Hosoda, O Mori, T Shimada, S Soldini, T Iwata, M Abe, H Yano, R Tsukizaki, M Ozaki, K Nishiyama, T Saiki, S Watanabe, Y Tsud

X-ray absorption near edge structure spectroscopic study of Hayabusa category 3 carbonaceous particles

Analyses with a scanning transmission x-ray microscope (STXM) using x-ray absorption near edge structure (XANES) spectroscopy were applied for the molecular characterization of two kinds of carbonaceous particles of unknown origin, termed category 3, which were collected from the Hayabusa spacecraft sample catcher. Carbon-XANES spectra of the category 3 particles displayed typical spectral patterns of heterogeneous organic macromolecules; peaks corresponding to aromatic/olefinic carbon, heterocyclic nitrogen and/or nitrile, and carboxyl carbon were all detected. Nitrogen-XANES spectra of the particles showed the presence of N-functional groups such as imine, nitrile, aromatic nitrogen, amide, pyrrole, and amine. An oxygen-XANES spectrum of one of the particles showed a ketone group. Differences in carbon- and nitrogen-XANES spectra of the category 3 particles before and after transmission electron microscopic (TEM) observations were observed, which demonstrates that the carbonaceous materials are electron beam sensitive. Calcium-XANES spectroscopy and elemental contrast mapping identified a calcium carbonate grain from one of the category 3 particles. No fluorine-containing molecular species were detected in fluorine-XANES spectra of the particles. The organic macromolecular features of the category 3 particles were distinct from commercial and/or biological ‘fresh (non-degraded)’ polymers, but the category 3 molecular features could possibly reflect degradation of contaminant polymer materials or polymer materials used on the Hayabusa spacecraft. However, an extraterrestrial origin for these materials cannot currently be ruled out