1,552 research outputs found
Photoionisation processes of oxygen and acetylene in the vacuum ultraviolet region
Photoionisation mass measurements on oxygen and acetylene molecules have been made in the wavelength region from 1100 to 400 A by using synchrotron radiation as a light source. Photoionisation spectra in oxygen are obtained for the molecular ion O2+ and for the fragment ion O+, and in acetylene are obtained for the molecular ion C2H2+ and for fragment ions C2H+, C2+, CH2+ and CH+. To assign the spectral structures of C2H2+, ab initio calculations have been performed for excitation from the second (3δg) and third (2δu) outer molecular orbitals. In the molecular ion spectra of these molecules, several broad structures are observed besides sharp structures due to autoionisation from rydberg states. The broad fetures are discussed in support of theoretical calculations. New Rydberg series (npÏuâ3δg) converging to the second ionisation threshold were found in the spectra of the molecular ion C2H2+. In the fragment ion spectra, appearance potentials of frabment ions are obtained from onsets of the spectra. Various decay channels after photoionisation are also decided in terms of the onsets.Thesis--University of Tsukuba, D.Sc.(B), no. 263, 1985. 7. 3
Neuronal and glial prostaglandin D synthase isozymes in chick dorsal root ganglia: a light and electron microscopic immunocytochemical study.
Homogenates of chick dorsal root ganglia (DRG) and in vitro cultures of DRG neurons are known to synthesize prostaglandin (PG) D2. To specify the PGD synthase isozymes controlling PGD2 synthesis in DRG and to identify the DRG cells responsible for this synthesis, we applied polyclonal antibodies raised against rat brain or rat spleen PGD synthase isozymes to vibratome or cryostat slices of DRG previously fixed with a formaldehyde-lysine-periodate mixture and permeabilized with Triton X-100. The immunoreactivity indicating rat spleen PGD synthase, a glutathione (GSH)-requiring enzyme, was located in satellite cells encompassing particular large neurons of class A and in Schwann cells myelinating and enwrapping their initial axonal segments. In contrast, the immunoreactivity of rat brain PGD synthase, a GSH-independent enzyme, was restricted to particular ganglion cell perikarya: 33% of the DRG neurons were immunostained for rat brain PGD synthase, including 2% of large class A neurons and 40% of small class B neurons. Only 3.3% of rat brain PGD synthase-immunoreactive small B neurons coexpressed substance P, indicating that the immunoreactive neurons belong to the B1 subclass. By electron microscopy, 71 of 72 immunoreactive DRG cells were identified as small B neurons of the B1 subclass, and 71 of 77 B1 neurons were immunoreactive for rat brain PGD synthase. These results demonstrate that PGD2 formation in DRG is regulated by two isozymes: the GSH-requiring isozyme located in satellite and Schwann cells and the GSH-independent isozyme-confined to small B1 neurons
旧版地図にみる大正年間の鎌倉市域の土地利用と現在との比較
神奈川県鎌倉市域39.5km²の大正時代の 2万5千分の1地形図と現在の植生図データを比較し、土地利用変化を分析した。その結果、 耕作地は10分の1に、森林は半分に減少した一方で、市街地は 5倍に増加したことが判明した。 このような大きな土地利用変化は例えばメダカの鎌倉地域個体群が野生絶滅したことなどのように、市街地と郊外に生息する野生生物に、悪い影響を与えてきたと考えられる。I analyzed the pattern of land use changes in 39.5km² of Kamakura City using a 1:25,000 scale map from 1921 and a current vegetation map. The results revealed that croplands are lesser by nearly one-tenth now as compared to in the Taisho era, and forests have been reduced by almost half. On the other hand, urban areas are five times larger. Such a drastic change in land use appears to have affected wild fauna and flora in both urban and suburban areas. For instance, a local population of wild Japanese medaka had become extinct in the area analyzed
Low-energy three-body charge transfer reactions with Coulomb interaction in the final state
Three-body charge transfer reactions with Coulomb interaction in the final
state are considered in the framework of coordinate-space integro-differential
Faddeev-Hahn-type equations within two- and six-state close coupling
approximations. The method is employed to study direct muon transfer in
low-energy collisions of the muonic hydrogen H by helium (He) and
lithium (Li) nuclei. The experimentally observed isotopic dependence is
reproduced.Comment: 14 pages REVTeX, accepted for publication in Journal of Physics
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