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801.
We consider the heat equation with a superlinear absorption term in and study the existence of nonnegative solutions with an m-dimensional time-dependent singular set, where . We prove that if , then there are two types of singular solutions. Moreover, we show the uniqueness of the solutions and specify the exact behavior of the solutions near the singular set. 相似文献
802.
Kojiro Kawada Yuya Uchida Ikuo Takahashi Takahito Nomura Yasuyuki Sasaki Tadao Asami Shunsuke Yajima Shinsaku Ito 《Molecules (Basel, Switzerland)》2020,25(23)
Strigolactones (SLs) are carotenoid-derived plant hormones involved in the development of various plants. SLs also stimulate seed germination of the root parasitic plants, Striga spp. and Orobanche spp., which reduce crop yield. Therefore, regulating SL biosynthesis may lessen the damage of root parasitic plants. Biosynthetic inhibitors effectively control biological processes by targeted regulation of biologically active compounds. In addition, biosynthetic inhibitors regulate endogenous levels in developmental stage- and tissue-specific manners. To date, although some chemicals have been found as SL biosynthesis inhibitor, these are derived from only three lead chemicals. In this study, to find a novel lead chemical for SL biosynthesis inhibitor, 27 nitrogen-containing heterocyclic derivatives were screened for inhibition of SL biosynthesis. Triflumizole most effectively reduced the levels of rice SL, 4-deoxyorobanchol (4DO), in root exudates. In addition, triflumizole inhibited endogenous 4DO biosynthesis in rice roots by inhibiting the enzymatic activity of Os900, a rice enzyme that converts the SL intermediate carlactone to 4DO. A Striga germination assay revealed that triflumizole-treated rice displayed a reduced level of germination stimulation for Striga. These results identify triflumizole as a novel lead compound for inhibition of SL biosynthesis. 相似文献
803.
In this paper we present a unified simple approach to anisotropic Hardy inequalities in various settings. We consider Hardy inequalities which involve a Finsler distance from a point or from the boundary of a domain. The sharpness and the non-attainability of the constants in the inequalities are also proved. 相似文献
804.
In this paper, we introduce an iterative scheme for finding a common fixed point of infinite nonexpansive mappings in a Hilbert space by using the hybrid method. Then, we prove a strong convergence theorem which is connected with the problem of image recovery. Further, using this result, we consider the generalized problem of image recovery and the problem of finding a common fixed point of a family of nonexpansive mappings. 相似文献
805.
Takayuki DoiNobuaki Fujimoto Jun WatanabeTakashi Takahashi 《Tetrahedron letters》2003,44(10):2161-2165
We have developed a practical route for the synthesis of peptides containing unnatural amino acids. Mizoroki-Heck reaction of polymer-supported dehydroalanine, followed by asymmetric hydrogenation was accomplished using Pd(0) and Rh(I)-DuPHOS catalysts, respectively, leading to 36 dipeptides containing phenylalanine derivatives with high stereocontrol. 相似文献
806.
Shuntaro Mataka Kazufumi Takahashi Masashi Tashiro Wei-Hua Lin Shin-Ichi Iwasaki Tetsuo Tsutsui Shogo Saito Shinji Akiyama Tadashi Yonemitsu 《Journal of heterocyclic chemistry》1989,26(1):215-219
Reversible color change of 4,6,7-tri(alkoxy-substituted phenyl)-1,2,5-thiadiazolo[3,4-c]pyridines 5 in the solid state was observed: on grinding, yellow crystals of 5 became an orange amorphous solid which, on heating or washing with an appropriate solvent, gave the original yellow crystals. 相似文献
807.
Ken-ichi Iwamoto Masako Hamaya Naoki Hashimoto Hitomi Kimura Yumiko Suzuki Masayuki Sato 《Tetrahedron letters》2006,47(40):7175-7177
Benzoin reactions are catalyzed by N,N-dialkylbenzimidazole to yield α-hydroxy ketones; the reaction proceeds in water as an aqueous medium under mild conditions. The utility of these salts as pre-catalysts in these reactions has been demonstrated. 相似文献
808.
809.
Terphenyl compounds, tentatively named Bl-I (1), Bl-II (2), Bl-III (3), Bl-IV (4) and Bl-V (5), showing 5-lipoxygenase inhibitory activity have been isolated from the mushroom Boletopsis leucomelas (Pers.) Fayod. On the basis of physico-chemical and spectral evidence, they were concluded to be a series of cycloleucomelone-leucoacetates. 相似文献
810.
T. Ohsaka Y. Shibata K. Ishi S. Takahashi M. Ishii Y. Fujiki 《Solid State Communications》1985,55(12):1119-1121
The reflection spectra of the one-dimensional ionic conductors K1.6Al1.6Ti6.4O16 and Rb1.49Al1.65Ti6.35O15.92 have been measured for the polarizations E ∥ c (channel direction) and E 6 c in the frequency region 60–2000 cm-1. The spectra of these two compounds are very similar with their features and have the same number of bands. The vibrational mode frequencies are obtained from a Kramers-Kronig analysis for each polarized reflectivity spectrum. A comparison of the corresponding mode frequencies for both priderites shows that only the lowest frequency mode observed in the E 6 c spectra is strongly associated with the alkali ion, while the others are not. The effect due to the non-stoichiometry is not found in the infrared reflection spectra. 相似文献