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971.
Chang Young Jung Wang Yao Jong Min Park Joong Hyun Cho Dae Hyun Kim Jae Yun Jaung 《Journal of inclusion phenomena and macrocyclic chemistry》2017,89(1-2):85-90
In this study, a novel tetrapyrazinoporphyrazine-based fluorescent sensor for Cu2+ ion was synthesized and fully characterized by 1H NMR, MALDI-TOF MS, and elemental analysis. A tetrapyrazinoporphyrazine substituent was used as the reporting group and a 2,2′-dipyridylamine moiety was employed as the recognition group. The effects of various metal ions on the absorption and emission spectra of the designed molecule were investigated, demonstrating that this compound shows selectivity and sensitivity toward the Cu2+ ion. Upon addition of Cu2+ ion, a fluorescent intensity of the tetrapyrazinoporphyrazine-based sensor decreased gradually at 655 nm. To confirm a selective binding ability of 2,2′-dipyridylamine moiety toward Cu2+ ion, a comparative study was performed using tetrapyrazinoporphyrazine derivative with bromine instead of 2,2′-dipyridylamine moiety. Furthermore, association constant and detection limit value of the synthesized compound toward Cu2+ ion were derived from a repetitive titration experiment. Also, a reversibility of the prepared sensor was confirmed through additional test using compound and ethylenediaminetetraacetic acid. 相似文献
972.
Vatsal (Duke Math J 98(2):397–419, 1999) proved that there are congruences between the p-adic L-functions (constructed by Mazur and Swinnerton-Dyer in Invent Math 25:1–61, 1974) of congruent modular forms of the same weight under some conditions. On the other hand, Kim (J Number Theory 144: 188–218, 2014), the second author, constructed two-variable p-adic L-functions of modular forms attached to imaginary quadratic fields generalizing Hida’s work (Invent Math 79:159–195, 1985), and the novelty of his construction was that it works whether p is an ordinary prime or not. In this paper, we prove congruences between the two-variable p-adic L-functions (of the second author) of congruent modular forms of different but congruent weights under some conditions when p is a nonordinary prime for the modular forms. This result generalizes the work of Emerton et al. (Invent Math 163(3): 523–580, 2006), who proved similar congruences between the p-adic L-functions of congruent modular forms of congruent weights when p is an ordinary prime. 相似文献
973.
Ho Cheol Jeong Suk Hyun Lim Youngku Sohn Young-Il Kim Hoeun Jang Dae Won Cho Patrick S. Mariano 《Tetrahedron letters》2017,58(10):949-954
Single electron transfer (SET)-promoted photoaddition reactions between fullerene C60 and both various alkyl (Me, Et, i-Pr, t-Bu)- and para-substituted (p-Me, p-OMe, p-F, p-CF3) arene ring containing, N-α-trimethylsilyl-N-alkyl-N-benzylamines were explored to gain information about photoproduct profiles and how the electronic and steric nature of the amine substrates influence reaction efficiencies. The results show that visible light (λ > 540 nm) irradiation of 10% EtOH-toluene solutions containing C60 and N-α-trimethylsilyl-N-alkyl-N-benzylamines produce 1-aminomethyl-1,2-dihydrofullerenes as a sole photoproduct. In addition, SET-promoted photoaddition reactions of unsubstituted and para-electron donating group substituted arene ring containing N-α-trimethylsilyl-N-alkyl-N-benzylamines take place to give photoproducts more efficiently than those containing para-electron withdrawing group substituted arene rings. Moreover, although steric factors are less significant than the electronic nature of the amine substrates in governing reaction efficiencies, sterics do play a significant role in photoreactions of electron deficient amine substrates. 相似文献
974.
[structure: see text]. We have discovered a new method employing Pd-catalyzed cycloreduction of conjugated enynals 1 bearing an alkyne unit leading to the corresponding 2-(2-methylenecycloalkyl)-furans 2a-j and a related compound 7 in good to excellent yields. 相似文献
975.
976.
Ha TH Park MR Park HJ Choi JS Kim G Hyun MS Chung BH 《Chemical communications (Cambridge, England)》2007,(16):1611-1613
Several nucleophiles such as proteins or poly(ethyleneimine) could be easily conjugated with a 11-(2,4-dinitro-5-fluorobenzene)undecenamide (DFUA) monolayer photochemically prepared on a silicon (100) surface. 相似文献
977.
Pigmentation may result from melanocyte proliferation, melanogenesis, migration or increases in dendricity. Recently, it has been reported that secreted phospholipase A(2)(sPLA(2)) known as a component of bee venom (BV), stimulates melanocyte dendricity and pigmentation. BV has been used clinically to control rheumatoid arthritis and to ameliorate pain via its anti-inflammatory and antinociceptive properties. Moreover, after treatment with BV, pigmentation around the injection sites was occasionally observed and the pigmentation lasted a few months. However, no study has been done about the effect of BV on melanocytes. Thus, in the present study, we examined the effect of BV on the proliferation, melanogenesis, dendricity and migration in normal human melanocytes and its signal transduction. BV increased the number of melanocytes dose and time dependently through PKA, ERK, and PI3K/Akt activation. The level of cAMP was also increased by BV treatment. Moreover, BV induced melanogenesis through increased tyrosinase expression. Furthermore, BV induced melanocyte dendricity and migration through PLA(2) activation. Overall, in this study, we demonstrated that BV may have an effect on the melanocyte proliferation, melanogenesis, dendricity and migration through complex signaling pathways in vitro, responsible for the pigmentation. Thus, our study suggests a possibility that BV may be developed as a therapeutic drug for inducing repigmentation in vitiligo skin. 相似文献
978.
Column chromatographic separation of a MeOH extract of the aerial parts of Saussurea triangulata led to the isolation of a new sesquiterpene glycoside 6, together with three quinic acid derivatives, two phenolics, two sesquiterpene glycosides and two flavonoids. The new compound 6 was identified as amarantholidol A glycoside by spectroscopic and chemical methods. 相似文献
979.
Shipman ST Douglass PC Yoo HS Hinkle CE Mierzejewski EL Pate BH 《Physical chemistry chemical physics : PCCP》2007,9(32):4572-4586
Ultrafast mid-IR transient absorption spectroscopy has been used to study the vibrational dynamics of hydrogen-bonded cyclic dimers of trifluoroacetic acid and formic acid in both the gas and solution phases (0.05 M in CCl(4)). Ultrafast excitation of the broad O-H cyclic dimer band leads, in the gas phase, to large-scale structural changes of the dimer creating a species with a distinct free O-H stretching band on 20 ps and 200 ps timescales. These timescales are assigned to ring-opening and dissociation of the dimer, respectively. In the solution phase, no such structural rearrangement occurs and our results are consistent with previous studies. The gas phase dynamics are insensitive to both the specific excitation energy (over a span of 550 cm(-1)) and the chemical identity of the dimer. 相似文献
980.
Matyja A Rozanska M Adachi I Aihara H Aulchenko V Aushev T Bahinipati S Bakich AM Balagura V Barberio E Bedny I Bhardwaj V Bitenc U Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chen A Chen KF Cheon BG Chistov R Cho IS Choi Y Choi YK Dalseno J Dash M Eidelman S Fratina S Gabyshev N Golob B Ha H Haba J Hara T Hayasaka K Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Hyun HJ Iijima T Ikado K Inami K Ishikawa A Ishino H Itoh R Iwasaki Y Kaji H Kajiwara S Kang JH Katayama N 《Physical review letters》2007,99(19):191807
We report an observation of the decay B{0}-->D{*-}tau{+}nu{tau} in a data sample containing 535x10{6} BB pairs collected with the Belle detector at the KEKB asymmetric-energy e{+}e{-} collider. We find a signal with a significance of 5.2sigma and measure the branching fraction B(B{0}-->D{*-}tau{+}nu{tau})=(2.02{-0.37}{+0.40}(stat)+/-0.37(syst))%. This is the first observation of an exclusive B decay with a b-->ctaunu{tau} transition. 相似文献