Article
Chemistry, Applied
Benjamin Malfait, Laurent Paccou, Natalia T. Correia, Yannick Guinet, Alain Hedoux
Summary: A very unusual amorphous-amorphous two-step transformation of indomethacin confined within MCM-41 mesoporous silica was observed, involving the growth of gamma-nanocrystals followed by their transformation to an undercooled liquid state structurally different from the original liquid. The unstable nanocrystals were explained to be a result of high specific area imposed by geometrical confinement, with dissolution mechanism similar to digestive ripening.
MICROPOROUS AND MESOPOROUS MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Shaun P. Akse, Gobind Das, Susana Agusti, Laetitia Pichevin, Lubos Polerecky, Jack J. Middelburg
Summary: By combining high spatial resolution imaging with nanoSIMS and Raman microspectroscopy, researchers were able to identify the location of organic material within cleaned fossil diatom frustules, showing that the organics were primarily concentrated near the pore walls. This study revealed the heterogeneous distribution of organics in the frustules and highlighted the limitations of Raman measurements in resolving spatial patterns compared to nanoSIMS imaging.
Article
Materials Science, Composites
Yeliz Basaran Elalmis, Sevil Yucel, Ismail Aydin
Summary: The study aimed to synthesize biogenic silica and investigate the impact of pH on silica gel formation on the properties of silica powders and light-cured dental composites. Results showed that the pH of silica gel formation significantly affected the properties of EDCs, suggesting that biogenic silica powders could be a low-cost alternative for dental fillers.
POLYMER COMPOSITES
(2021)
Article
Multidisciplinary Sciences
Jan Taucher, Lennart T. Bach, A. E. Friederike Prowe, Tim Boxhammer, Karin Kvale, Ulf Riebesell
Summary: Ocean acidification affects diatom growth and reduces the availability of silicic acid in the surface ocean.
Article
Chemistry, Physical
T. I. Milenov, I. A. Avramova, A. Dikovska, D. Karaivanova, P. Terziyska, S. K. Kolev, D. Karashanova, B. Georgieva, D. Dimov, V. Atanasov, E. P. Valcheva
Summary: The study found that UV-C irradiation had a significant impact on the structural quality of a-C:H and ta-C:H films, reducing the content of sp(3) and oxygen-containing radicals. The influence of UV-C light directed almost parallel to the films' surface on the structural quality of graphene-like films was slightly higher than that directed perpendicular.
SURFACES AND INTERFACES
(2021)
Article
Geochemistry & Geophysics
Jens Goetze, Klaus Stanek, Gerardo Orozco, Moritz Liesegang, Tanja Mohr-Westheide
Summary: The investigation of agates in Paleocene/Eocene tuffs from El Picado/Los Indios, Cuba revealed abnormal high contents of opal-CT and moganite, indicating a multi-phase deposition of SiO2 under varying physico-chemical conditions and a discontinuous silica supply.
Article
Chemistry, Multidisciplinary
Yao Yan, Yanan Fang, Jun Li, Yongqiang Yang, Fanrong Chen, Shijun Wu, Thomas Hooper, Ankit Jaiswal, Tim White
Summary: This article presents a new method to synthesize monoclinic nHAp from ACP at room temperature without crystallization inhibitors, and the use of Raman spectroscopy as a reliable technique to observe the crystallization process.
Article
Construction & Building Technology
Marine Georges, Amel Bourguiba, Mohamed Boutouil, Daniel Chateigner, Orianne Jolly, Pascal Claquin
Summary: This study evaluated the ability of the benthic diatom C. closterium to use mortar from artificial marine structures as a source of silicon for their metabolism and growth. The study found that the diatoms were able to utilize dissolved silica from the mortar to synthesize their cell wall and adapt to limited silicon conditions.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Zoology
Ana Riesgo, Sergi Taboada, Nathan J. Kenny, Nadia Santodomingo, Juan Moles, Carlos Leiva, Eileen Cox, Conxita Avila, Luis Cardona, Manuel Maldonado
Summary: Research in Antarctica has shown that sponges commonly convert ingested diatom silica into sponge silica, a process supported by upregulation of specific genes and examination of silica composition. This reutilization of diatom silica by sponges is a common feature in Antarctic sponges and warrants further investigation in other regions and organisms with siliceous skeletons.
ZOOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
(2021)
Article
Pharmacology & Pharmacy
Adrian Krummnow, Andreas Danzer, Kristin Voges, Samuel O. O. Kyeremateng, Matthias Degenhardt, Gabriele Sadowski
Summary: The poor bioavailability of an API can be improved by dissolving it in a polymeric matrix through the formation of an amorphous solid dispersion (ASD). Crystallization and amorphous phase separation of the API can decrease its bioavailability. This study quantified the kinetics of water-induced amorphous phase separation in RIT/PVPVA ASDs and determined the compositions of the evolving amorphous phases using confocal Raman spectroscopy.
Article
Microbiology
Brittany N. Zepernick, Eric R. Gann, Robbie M. Martin, Helena L. Pound, Lauren E. Krausfeldt, Justin D. Chaffin, Steven W. Wilhelm
Summary: This study investigated the effects of high alkaline pH on the ecologically relevant diatom Fragilaria crotonensis, both in vitro and in Lake Erie. The results showed that elevated pH levels suppressed the growth rate and silica deposition of diatoms, creating a competitive disadvantage for them.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Microbiology
Penelope A. Ajani, Katherina Petrou, Michaela E. Larsson, Daniel A. Nielsen, Joel Burke, Shauna A. Murray
Summary: The study found significant intraspecific morphological and metabolic trait variability in marine phytoplankton, predominantly within species rather than between species. There were only a few traits that showed a latitudinal trend.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Nanoscience & Nanotechnology
Kevin M. Cole, Jehad Abed, Donald W. Kirk, Steven J. Thorpe
Summary: The two-stage ball milling process was used for synthesizing amorphous Ni and Ni-Co alloy nanoparticles, which exhibited excellent catalytic performance towards OER.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Pharmacology & Pharmacy
Yannick Guinet, Laurent Paccou, Alain Hedoux
Summary: Designing co-amorphous formulations is an effective strategy to improve the bioavailability of low-molecular-weight drugs. This study focused on analyzing the thermal stability of co-amorphous blends of indomethacin and amino acids, in order to understand the stabilization mechanism of the drug in its amorphous state. The results revealed the surprising capability of L-arginine to enhance the stability of amorphous indomethacin by strengthening its H-bond network.
Article
Geosciences, Multidisciplinary
Xia Zhao, Zhi Zheng, Jiangzhi Chen, Yue Gao, Jianhui Sun, Xue Hou, Mengjun Xiong, Shenghua Mei
Summary: The phase transition between calcite and aragonite is important for the global carbon cycle, but its study under high P-T conditions has been lacking. This study investigated the phase transitions under both anhydrous and hydrous conditions. It was found that the phase transition can occur under a wide range of pressure and temperature. Further investigation is needed to understand the impact of aqueous fluid on the phase transition.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Paleontology
Takashi Chiba, Yuichi Nishimura, Yukio Yanagisawa
Summary: The study focused on the distribution of modern and Neogene diatom assemblages in the Toberi River area of eastern Hokkaido, Japan, and analyzed changes in fossil diatom assemblages during the late Holocene. The results suggest that when reconstructing Holocene paleoenvironments, allochthonous, extinct, and persistent extant taxa should be excluded from diatom assemblage analysis.
MARINE MICROPALEONTOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Yoshifumi Horie, Takashi Chiba, Chiho Takahashi, Norihisa Tatarazako, Taisen Iguchi
Summary: In this study, the negative effects of triphenyltin (TPT) on zebrafish were assessed by exposing embryos and early-stage larvae to different concentrations of TPT. It was found that TPT could lead to swim bladder developmental abnormalities and mortality in early-stage larvae, and may disrupt the thyroid system in zebrafish.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
(2021)
Article
Geography, Physical
Masaki Yamada, Shigehiro Fujino, Takashi Chiba, Catherine Chague, Daisuke Takeda
Summary: The study focused on onshore sediment cores from Beppu Bay in northern Kyushu Island, Japan, to investigate prehistoric intraplate earthquakes' potential generation of tsunamis and establish a chronology for these events. Findings included identifying distinct sand layers and dating them using radiocarbon age modeling, as well as linking tsunami deposits to volcanic eruptions, fault ruptures, and environmental changes.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Vincenzo Stagno, Luca Bindi, Sota Takagi, Atsushi Kyono
Summary: The compressional behavior of i-AlCuFe quasicrystal under high pressure conditions was investigated, showing continuous decrease in d-spacing with pressure but without structural phase transformations or amorphization. The study helps expand our understanding of the stability of icosahedrite at very high pressure and supports the evidence of natural quasicrystals surviving in the history of the Solar System.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2021)
Article
Physics, Applied
Sota Takagi, Koji Inukai, Nobuaki Kawai, Shunsuke Nozawa, Atsushi Kyono, Ryo Fukaya, Shin-ichi Adachi, Kouhei Ichiyanagi
Summary: The study reveals the behavior of transformation-toughened materials under dynamic loading, emphasizing the relationship between crystal structure transformations and dynamic fracture, providing an explanation for the high spall strength of zirconia ceramics, and demonstrating the great potential of the time-resolved x-ray diffraction method in studying fracture dynamics.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Analytical
Hirokazu Madokoro, Osamu Kiguchi, Takeshi Nagayoshi, Takashi Chiba, Makoto Inoue, Shun Chiyonobu, Stephanie Nix, Hanwool Woo, Kazuhito Sato
Summary: This study developed a new platform using a drone for in situ atmospheric measurements, focusing on particulate matter pollution, which is a major global concern. The research team created a lightweight and cost-effective sensor system with real-time monitoring and data visualization capabilities. Results from calibration experiments showed that the sensor system followed overall trends and changes, and prediction results matched regional PM2.5 trends from long short-term memory networks trained using the datasets.
Article
Chemistry, Inorganic & Nuclear
Ryutaro Ikeda, Atsushi Kyono
Summary: Mirabilite, a representative phase change material, exhibits temperature-dependent structural behavior due to the expansion of Na(H2O)(6) octahedra and changes in SO4 tetrahedra. The shrinking of the major SO4 tetrahedron with increasing temperature leads to oxygen diffusion to the minor SO4 tetrahedron, impacting the occupancy of oxygen sites. The crystal structure of mirabilite consists of ribbons of Na(H2O)(6) octahedra and chains of SO4 tetrahedra, with a phase change to thenardite immediately occurring after dehydration.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Materials Science, Multidisciplinary
Sota Takagi, Kouhei Ichiyanagi, Atsushi Kyono, Nobuaki Kawai, Shunsuke Nozawa, Norimasa Ozaki, Yusuke Seto, Takuo Okuchi, Souma Nitta, Satoru Okada, Kohei Miyanishi, Keiichi Sueda, Tadashi Togashi, Toshinori Yabuuchi
Summary: In this study, the phase transition dynamics of shock-compressed zircon (ZrSiO4) were investigated using laser-driven shock compression coupled with in situ X-ray diffraction for the first time. The results showed that zircon can undergo a phase transition to the high-pressure reidite phase under nanosecond timescale laser-driven shocks. The diffraction peaks of zircon and reidite appeared superimposed on a diffuse background attributed to liquid scattering from partial melt. Upon release, the melt recrystallized into a combination of zircon and reidite, indicating the kinetically inhibited decomposition of zircon to SiO2 and ZrO2.
PHYSICS AND CHEMISTRY OF MINERALS
(2022)
Article
Geosciences, Multidisciplinary
Erick R. Velasco-Reyes, Kazuhisa Goto, Daisuke Sugawara, Yuichi Nishimura, Takahiro Shinohara, Takashi Chiba
Summary: This study revealed the paleotsunami history of Hachinohe in northern Tohoku, Japan. Through various methods, seven sand layers in the area were identified as event deposits of marine origin. The study also highlighted the importance of conducting more paleotsunami research in the Shimokita Peninsula to understand the tsunami-genic sources northward of the Tohoku region.
PROGRESS IN EARTH AND PLANETARY SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Takashi Chiba, Yuichi Nishimura
Summary: This study investigates the sand deposits caused by a tsunami triggered by the Nihonkai-Chubu earthquake in 1983. The research discovers a sand layer in the soil that thinned inland, indicating that the sand was transported from the coast. The study confirms that the sand layer was deposited by the 1983 tsunami and also identifies another sand layer possibly formed by a typhoon in 1991.
EARTH PLANETS AND SPACE
(2022)
Article
Biochemistry & Molecular Biology
Yoshifumi Horie, Takahiro Yamagishi, Jun Yamamoto, Mayumi Suzuki, Yuta Onishi, Takashi Chiba, Shinichi Miyagawa, Anke Lange, Charles R. Tyler, Hideo Okamura, Taisen Iguchi
Summary: Thyroid-hormone-disrupting chemicals PTU and TBBPA were investigated for their effects on Japanese medaka. PTU exposure resulted in reductions in eye size, growth, and swim bladder inflation, leading to poorer swimming performance. TBBPA exposure affected gene expression but had no significant effects on phenotypes.
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY C-TOXICOLOGY & PHARMACOLOGY
(2023)
Article
Environmental Sciences
Yoshifumi Horie, Takashi Chiba
Summary: Japanese medaka, as a model fish, shows different responses to endocrine-disrupting chemicals between the northern Oryzias sakaizumii and the southern O. latipes. Exposure to bisphenol A and 17 beta-trenbolone induced sex reversal in O. sakaizumii and had lower effects compared to O. latipes. These findings demonstrate the different responses of O. sakaizumii and O. latipes to androgenic and estrogenic endocrine-disrupting chemicals.
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
(2023)
Article
Plant Sciences
Takashi Chiba, Yoshifumi Horie, Akihiro Tuji
Summary: This study investigates the relationship between diatom species and salinity by culturing seven benthic diatom species from Lake Akan in Japan. The results show that Epithemia adnata, E. frickei, E. gibba, and E. sorex grow in freshwater to brackish-water environments, while Epithemia operculata and E. sp. can adapt to hypersaline environments. E. turgida has the narrowest salinity tolerance range. These findings provide new insights into the ecology of these species in modern environments and paleoenvironmental reconstructions through diatom analysis.
Article
Mineralogy
Risa Kuwamura, Sota Takagi, Atsushi Kyono
Summary: The effect of oxygen defects on the perovskite structure under high pressure was investigated using high-pressure Raman spectroscopy and synchrotron powder X-ray diffraction analyses. The results showed the appearance of new Raman bands and an increase in intensity with increasing pressure. Additionally, the X-ray diffraction analysis revealed the phase transition behavior of the perovskite structure.
JOURNAL OF MINERALOGICAL AND PETROLOGICAL SCIENCES
(2023)
Article
Mineralogy
Gen-ichiro Yamamoto, Atsushi Kyono, Jun Abe, Asami Sano-Furukawa, Takanori Hattori
Summary: Neutron diffraction, Raman spectroscopy, and thermal analysis were used to investigate the composition, structure, and formation conditions of magnesium carbonate hydrate nesquehonite. The crystal structure was confirmed to be monoclinic, with refinement results showing coordination of deuterium atoms to specific oxygen atoms as water molecules. The inclusion of three water molecules in the structure suggests a revised structural formula for nesquehonite.
JOURNAL OF MINERALOGICAL AND PETROLOGICAL SCIENCES
(2021)