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941.
Nobuyuki Mase Azusa Inoue Masaki Nishio Kunihiko Takabe 《Bioorganic & medicinal chemistry letters》2009,19(14):3955-3958
Optically active lactones are important synthons in perfume and aroma manufacturing. Therefore, developments of efficient asymmetric syntheses are desired. Organocatalytic asymmetric α-hydroxymethylations of cyclopentanone with aqueous formaldehyde have been developed, to furnish the corresponding α-(hydroxymethyl)cyclopentanone with high enantioselectivity. Further chemical transformation of α-(hydroxymethyl)cyclopentanone gave the key intermediate for jasmine lactone, which is widely found in fruits and flowers. 相似文献
942.
Saika Azusa Koike Hideaki Fukuoka Tokuma Morita Tomotake 《Applied microbiology and biotechnology》2018,102(16):6877-6884
Applied Microbiology and Biotechnology - Mannosylerythritol lipids (MELs) are a type of glycolipid biosurfactant produced by basidiomycetous yeasts, most notably those belonging to the genera... 相似文献
943.
Breeding season and nesting assemblages in two forms oflethenteron reissneri, with reference to reproductive isolating mechanisms 总被引:1,自引:1,他引:0
The level of reproductive isolation and reproductive characteristics were examined in sympatric populations of the northern
and southern forms ofLethenteron reissneri, in the Ushiwatari Stream, a tributary of the Gakko River, Yamagata Prefecture, Japan, to elucidate the reproductive isolating
mechanisms existing between them. Extensive allozyme data showed no gene exchange between the two forms in the study area,
evidence of their strict reproductive isolation from each other. The spawning seasons overlapped between the northern and
southern forms, the spawning period of the latter being slightly later than that of the former. The size at maturity also
overlapped between the two forms, although the southern form indicated significantly larger in average size than the northern
one. These results suggested that neither seasonal reproductive isolation nor size assortative mating occurred. On the other
hand, the nesting assemblages were observed to comprise only males and females of each respective form, suggesting that a
recognition system restricted to each form may operate as a premating isolating mechanism. 相似文献
944.
Hayato Terayama Takayuki Yoshimoto Shuichi Hirai Munekazu Naito Ning Qu Naoyuki Hatayama Shogo Hayashi Kana Mitobe Jun-ichi Furusawa Izuru Mizoguchi Takeshi Kezuka Hiroshi Goto Kaori Suyama Hiroshi Moriyama Kou Sakabe Masahiro Itoh 《PloS one》2014,9(4)
The testis is an organ with immune privilege. The comprehensive blood–testis barrier formed by Sertoli cells protects autoimmunogenic spermatozoa and spermatids from attack by the body’s immune system. The interleukin (IL)-6/IL-12 family cytokines IL-12 (p35/p40), IL-23 (p19/p40), IL-27 (p28/Epstein-Barr virus−induced gene 3 [EBI3]), and IL-35 (p35/EBI3) play critical roles in the regulation of various immune responses, but their roles in testicular immune privilege are not well understood. In the present study, we investigated whether these cytokines are expressed in the testes and whether they function in the testicular immune privilege by using mice deficient in their subunits. Expression of EBI3 was markedly increased at both mRNA and protein levels in the testes of 10- or 12-week-old wild-type mice as compared with levels in 2-week-old mice, whereas the mRNA expression of p40 was markedly decreased and that of p35 was conserved between these two groups. Lack of EBI3, p35, and IL-12 receptor β2 caused enhanced infiltration of lymphocytes into the testicular interstitium, with increased interferon-γ expression in the testes and autoantibody production against mainly acrosomal regions of spermatids. Spermatogenic disturbance was more frequently observed in the seminiferous tubules, especially when surrounded by infiltrating lymphocytes, of these deficient mice than in those of wild-type mice. In particular, p35-deficient mice showed the most severe spermatogenic disturbance. Immunohistochemical analyses revealed that endothelial cells and peritubular cells in the interstitium were highly positive for p35 at both ages, and CD163+ resident macrophages positive for p35 and EBI3, possibly producing IL-35, were also detected in the interstitium of 12-week-old mice but not those of 2-week-old mice. These results suggest that p35 helps in maintaining the testicular immune privilege, in part in an IL-35-dependent manner. 相似文献
945.
946.
Lamprey larvae as ecosystem engineers: physical and geochemical impact on the streambed by their burrowing behavior 总被引:1,自引:0,他引:1
Larval lampreys are thought to have a significant impact on freshwater ecosystems because of their high densities and broad distributions. However, the significance of their role in the stream ecosystem remains unclear. In general, it is reported that filter feeders alter their habitat conditions (oxygen, organic matter, and nutrients levels). We evaluated the impacts of two lamprey species larvae on the physical and geochemical factors in streambed by their burrowing and feeding behavior using in situ enclosures in a mountainous river located in northern Japan. During a 21-day field experiment, we found that the larvae treatments compared to the controls (no larvae) caused increased oxygen levels in the streambed, maintained the relative softness of the streambed and increased the FPOM abundance on the streambed surface. The substantial impact of the lamprey larvae on the physical and geochemical conditions in the streambed may be attributable to their burrowing and feeding behavior. Hence, our findings contribute to understanding the importance of the conservation and management of lamprey populations in order to maintain the freshwater ecosystem. Additional experiments using lamprey larvae are needed to reveal their impact on biotic factors (aquatic insects, algae, etc.) in and around the larval habitats. 相似文献
947.
T Nishikawa M Goto S Shimizu 《Biochemical and biophysical research communications》1985,126(2):893-900
Phosphatidylinositol and several other phospholipids were tested for their ability to influence the (Na+ + K+)-ATPase activity of the cortical synaptic membrane from rats at various levels of free Ca2+. Phosphatidylinositol, but not phosphatidylethanolamine, phosphatidylcholine nor phosphatidylserine, markedly inhibited this enzyme activity, when the free Ca2+ concentration in the incubation media was less than 2.5 X 10(-6) M. This result suggests that phosphatidylinositol may play a role in the depolarization and/or the release of neurotransmitters or intracellular substances in the brain. 相似文献
948.
Endothelin-3 concentrations in human plasma: the increased concentrations in patients undergoing haemodialysis 总被引:3,自引:0,他引:3
N Suzuki H Matsumoto T Miyauchi K Goto T Masaki M Tsuda M Fujino 《Biochemical and biophysical research communications》1990,169(2):809-815
Plasma immunoreactive endothelin-3 (ir-ET-3) concentrations were measured by a sandwich-enzyme immunoassay (sandwich-EIA) for endothelin-3 (ET-3). The assay method consists of two antibodies directed against N-terminal and C-terminal portions of ET-3. It detects as little as 0.1 pg/well of ET-3 without the crossreaction with endothelin-1, endothelin-2 and big ET-3. Plasma ir-ET-3 concentrations were found to be 0.45 +/- 0.07 pg/ml (mean +/- SD) in healthy volunteers, and were increased in patients undergoing haemodialysis (0.83 +/- 0.26 pg/ml, p less than 0.001). In reverse-phase HPLC, ir-ET-3 in normal plasma and in plasma of haemodialysis patients was eluted at the position of authentic ET-3, indicating that ir-ET-3 in plasma detected by the EIA was ET-3 itself. These results suggest that circulating ET-3 exists in normal human plasma and that production and/or metabolism of ET-3 may be altered in patients undergoing haemodialysis. 相似文献
949.
Yoshitaka Shimotai Takanari Goto Yoko Matsuzaki Yasushi Muraki Kanetsu Sugawara Seiji Hongo 《Biochemistry and Biophysics Reports》2015
CM2 is an integral membrane protein encoded by the influenza C virus M gene. To examine the effects of the cytoplasmic tail of CM2 on its biochemical properties, deletion and substitution mutations were introduced into CM2 cytoplasmic tail at residues 47–115, and the expressed CM2 mutants were investigated. Although the cytoplasmic tail is not essential for the oligomerization of CM2, it may affect the degree of oligomerization. The residues 47–48, 67–69, 73–90 and 113–115 were all required for the proper expression of CM2. Pulse-chase experiments suggest that residues 47–48, 67–69, 73–75 and 79–87 stabilize CM2, thereby affecting CM2 expression. The C-terminal region at residues 61–115 is not essential for CM2 transport to the cell surface, and a 14-amino-acid, but not an 11-amino-acid, cytoplasmic tail is sufficient for the cell surface expression of CM2. These results suggest that either certain amino acid sequences or the length of the CM2 cytoplasmic tail are necessary for the proper conformational maturation, stability, expression level and intracellular transport of CM2. 相似文献
950.
Teiji Kuzuya Masatoshi Ishigami Yoji Ishizu Takashi Honda Kazuhiko Hayashi Yoshiaki Katano Yoshiki Hirooka Tetsuya Ishikawa Isao Nakano Hidemi Goto 《PloS one》2015,10(9)