| 1. |
- Bowman, John L, et al.
(author)
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Insights into Land Plant Evolution Garnered from the Marchantia polymorpha Genome
- 2017
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In: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 171:2, s. 287-304.15
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Journal article (peer-reviewed)abstract
- The evolution of land flora transformed the terrestrial environment. Land plants evolved from an ancestral charophycean alga from which they inherited developmental, biochemical, and cell biological attributes. Additional biochemical and physiological adaptations to land, and a life cycle with an alternation between multicellular haploid and diploid generations that facilitated efficient dispersal of desiccation tolerant spores, evolved in the ancestral land plant. We analyzed the genome of the liverwort Marchantia polymorpha, a member of a basal land plant lineage. Relative to charophycean algae, land plant genomes are characterized by genes encoding novel biochemical pathways, new phytohormone signaling pathways (notably auxin), expanded repertoires of signaling pathways, and increased diversity in some transcription factor families. Compared with other sequenced land plants, M. polymorpha exhibits low genetic redundancy in most regulatory pathways, with this portion of its genome resembling that predicted for the ancestral land plant. PAPERCLIP.
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| 2. |
- Hama, Tetsuya, et al.
(author)
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A desorption mechanism of water following vacuum-ultraviolet irradiation on amorphous solid water at 90 K
- 2010
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In: JOURNAL OF CHEMICAL PHYSICS. - 0021-9606. ; 132:16
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Journal article (peer-reviewed)abstract
- Following 157 nm photoexcitation of amorphous solid water and polycrystalline water ice, photodesorbed water molecules (H2O and D2O), in the ground vibrational state, have been observed using resonance-enhanced multiphoton ionization detection methods. Time-of-flight and rotationally resolved spectra of the photodesorbed water molecules were measured, and the kinetic and internal energy distributions were obtained. The measured energy distributions are in good accord with those predicted by classical molecular dynamics calculations for the kick-out mechanism of a water molecule from the ice surface by a hot hydrogen (deuterium) atom formed by photodissociation of a neighboring water molecule. Desorption of D2O following 193 nm photoirradiation of a D2O/H2S mixed ice was also investigated to provide further direct evidence for the operation of a kick-out mechanism.
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| 3. |
- He, Guang S., et al.
(author)
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Twisted pi-System Chromophores for All-Optical Switching
- 2011
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In: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 133:17, s. 6675-6680
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Journal article (peer-reviewed)abstract
- Molecular chromophores with twisted pi-electron systems have been shown to possess unprecedented values of the quadratic hyperpolarizability, beta, with very large real parts and much smaller imaginary parts. We report here an experimental and theoretical study which shows that these twisted chromophores also possess very large values of the real part of the cubic hyperpolarizability, gamma, which is responsible for nonlinear refraction. Thus, for the two-ring twisted chromophore TMC-2 at 775 nm, relatively close to one-photon resonance, n(2) extrapolated to neat substance is large and positive (1.87 x 10(-13) cm(2)/W), leading to self-focusing. Furthermore, the third-order response includes a remarkably low two-photon absorption coefficient, which means minimal nonlinear optical losses: the T factor, alpha(2)lambda/n(2), is 0.308. These characteristics are attributed to closely spaced singlet biradical and zwitterionic states and offer promise for applications in all-optical switching.
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| 4. |
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| 5. |
- Kobayashi, Kensei, et al.
(author)
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Laboratory Studies of Methane and Its Relationship to Prebiotic Chemistry
- 2017
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In: Astrobiology. - : Mary Ann Liebert Inc. - 1531-1074 .- 1557-8070. ; 17:8, s. 786-812
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Research review (peer-reviewed)abstract
- To examine how prebiotic chemical evolution took place on Earth prior to the emergence of life, laboratory experiments have been conducted since the 1950s. Methane has been one of the key molecules in these investigations. In earlier studies, strongly reducing gas mixtures containing methane and ammonia were used to simulate possible reactions in the primitive atmosphere of Earth, producing amino acids and other organic compounds. Since Earth's early atmosphere is now considered to be less reducing, the contribution of extraterrestrial organics to chemical evolution has taken on an important role. Such organic molecules may have come from molecular clouds and regions of star formation that created protoplanetary disks, planets, asteroids, and comets. The interstellar origin of organics has been examined both experimentally and theoretically, including laboratory investigations that simulate interstellar molecular reactions. Endogenous and exogenous organics could also have been supplied to the primitive ocean, making submarine hydrothermal systems plausible sites of the generation of life. Experiments that simulate such hydrothermal systems where methane played an important role have consequently been conducted. Processes that occur in other Solar System bodies offer clues to the prebiotic chemistry of Earth. Titan and other icy bodies, where methane plays significant roles, are especially good targets. In the case of Titan, methane is both in the atmosphere and in liquidospheres that are composed of methane and other hydrocarbons, and these have been studied in simulation experiments. Here, we review the wide range of experimental work in which these various terrestrial and extraterrestrial environments have been modeled, and we examine the possible role of methane in chemical evolution.
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| 6. |
- Koga, Shigehiro, et al.
(author)
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In vivo subcellular imaging of tumors in mouse models using a fluorophore-conjugated anti-carcinoembryonic antigen antibody in two-photon excitation microscopy
- 2014
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In: Cancer Science. - : Wiley. - 1347-9032 .- 1349-7006. ; 105:10, s. 1299-1306
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Journal article (peer-reviewed)abstract
- Recently, there has been growing interest in applying fluorescence imaging techniques to the study of various disease processes and complex biological phenomena in vivo. To apply these methods to clinical settings, several groups have developed protocols for fluorescence imaging using antibodies against tumor markers conjugated to fluorescent substances. Although these probes have been useful in macroscopic imaging, the specificity and sensitivity of these methods must be improved to enable them to detect micro-lesions in the early phases of cancer, resulting in better treatment outcomes. To establish a sensitive and highly specific imaging method, we used a fluorophore-conjugated anti-carcinoembryonic antigen (CEA) antibody to perform macroscopic and microscopic in vivo imaging of inoculated cancer cells expressing GFP with or without CEA. Macroscopic imaging by fluorescence zoom microscopy revealed that bio-conjugation of Alexa Fluor 594 to the anti-CEA antibody allowed visualization of tumor mass consisting of CEA-expressing human cancer cells, but the background levels were unacceptably high. In contrast, microscopic imaging using a two-photon excitation microscope and the same fluorescent antibody resulted in subcellular-resolution imaging that was more specific and sensitive than conventional imaging using a fluorescence zoom microscope. These results suggest that two-photon excitation microscopy in conjunction with fluorophore-conjugated antibodies could be widely adapted to detection of cancer-specific cell-surface molecules, both in cancer research and in clinical applications.
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| 7. |
- Yazawa, Aki, et al.
(author)
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Association between social participation and hypertension among older people in Japan : the JAGES Study
- 2016
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In: Hypertension Research. - : Springer Science and Business Media LLC. - 0916-9636 .- 1348-4214. ; 39, s. 818-824
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Journal article (peer-reviewed)abstract
- Hypertension is an important risk factor for cardiovascular disease, the leading cause of mortality in the world. Although previous studies have focused on individual-level behavioral risk factors associated with hypertension, there has been little research on how interacting with others, that is social participation, affects hypertension. To address this research gap, this study examined the association between social participation and hypertension in Japan, a country with a high prevalence of hypertension possibly linked to rapid population aging. Data were used from 4582 participants aged more than 65 years who participated in the Japan Gerontological Evaluation Survey (JAGES) with blood pressure data collected during a health check-up. The frequency of participation in vertical organizations (characterized by hierarchical relationships) and horizontal organizations (characterized by non-hierarchical, egalitarian relationships) was measured by a questionnaire. In a Poisson regression analysis, participation in vertical organizations was not associated with hypertension, whereas participation in horizontal organizations at least once a month was inversely associated with hypertension (prevalence ratio: 0.941). This association remained significant after adjusting for social support variables, although further adjustment for health behaviors attenuated the association. As the frequency of going out and average time spent walking were both associated with hypertension, physical activity may be a possible pathway that connects social participation and hypertension. The results of this study suggest that expanding social participation programs, especially those involving horizontal organizations, may be one way to promote better health among older people in Japan.
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