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991.
Yun-Nan Yan Dan-Yan Lin Wen-Long Pan Xiu-Ling Li Yi-Qian Wan Yu-Liang Mai Hua-Can Song 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(1):233-242
Eight 2-(9-phenanthrenyl)-, 2-(9-anthryl)- and 2-(1-pyrenyl)-1-alkyl-benzimidazole compounds, three 2-(9-anthryl)-1-alkylphenanthroimidazole compounds and five 4,5-diphenyl-1-alkyl-2-(9-anthryl)imidazole compounds were synthesized by alkylation reactions of the corresponding benzimidazole, phenanthroimidazole or imidazole compounds. 2-(10-Bromo-9-anthryl)-1-alkyl-benzimidazole compounds were prepared by bromination reaction of 2-(9-anthryl)-1-alkylbenzimidazole compounds. All the synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR, MS or HRMS; their absorption coefficients (), maximum absorption λamax, fluorescence emission maximum λem, Stokes shifts and fluorescence quantum yields (ΦF) in ethyl acetate were determined; their fluorescent lifetimes (T1 and T2) were measured in ethyl acetate and in solid state, respectively. The crystal structure of 2-(9-anthryl)-1-n-butyl-4,5-diphenylimidazole (12a) was determined to be triclinic, space group P-1 types, using single crystal X-ray crystallography technique. The results showed that these compounds exhibited moderate fluorescence-emission abilities and higher solubility in most organic solvents than their corresponding starting materials. The relationships between the optical behaviors and structures for these compounds were discussed. 相似文献
992.
Atsushi Ikeda Dr. Mai Nagano Motofusa Akiyama Dr. Masashi Matsumoto Sayuri Ito Masaru Mukai Mineo Hashizume Dr. Jun‐ichi Kikuchi Prof. Kiyofumi Katagiri Dr. Takuya Ogawa Dr. Tatsuo Takeya Prof. 《化学:亚洲杂志》2009,4(1):199-205
[70]Fullerene (C70) encapsulated into a surface‐cross‐linked liposome, a so‐called cerasome, was prepared by an exchange reaction incorporating C70?γ‐cyclodextrin complexes into lipid membranes. Fullerene exchange in a cerasome‐incorporated C70 (CIC70), as well as in a lipid‐membrane‐incorporated C70 (LMIC70), was completed within 1 min with stirring at 25 °C. CIC70 was more resistant to lysis than LMIC70 towards lysing agents such as surfactants. Furthermore, the photodynamic activity of CIC70 in HeLa cells was similar to that of LMIC70, indicating that C70 can act as a photosensitizing drug (PS) without release from cerasome membranes. Thus, in contrast with general drug‐delivery systems (DDSs), which require the drug to be released from the interior of liposomes, carriers for PSs for use in photodynamic therapy (PDT) do not necessarily need to release the drug. These results indicate that DDSs with high morphological stability can increase the residence time in blood and achieves tumor‐selective drug delivery by the enhanced permeability and retention (EPR) effect. 相似文献
993.
Nagano T 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2010,86(8):837-847
Fluorescent probes, which allow visualization of cations such as Ca(2+), Zn(2+) etc., small biomolecules such as nitric oxide (NO) or enzyme activities in living cells by means of fluorescence microscopy, have become indispensable tools for clarifying functions in biological systems. This review deals with the general principles for the design of bioimaging fluorescent probes by modulating the fluorescence properties of fluorophores, employing mechanisms such as acceptor-excited Photoinduced electron Transfer (a-PeT), donor-excited Photoinduced electron Transfer (d-PeT), and spirocyclization, which have been established by our group. The a-PeT and d-PeT mechanisms are widely applicable for the design of bioimaging probes based on many fluorophores and the spirocyclization process is also expected to be useful as a fluorescence off/on switching mechanism. Fluorescence modulation mechanisms are essential for the rational design of novel fluorescence probes for target molecules. Based on these mechanisms, we have developed more than fifty bioimaging probes, of which fourteen are commercially available. The review also describes some applications of the probes developed by our group to in vitro and in vivo systems. 相似文献
994.
Excessive calcium influx in chemosensitive neurons of area postrema (AP) is detrimental for sympathetic activation and participates in the disruption of cardiovascular activities. Since total sleep deprivation (TSD) is a stressful condition known to harm the cardiovascular function, the present study is aimed to determine whether the in vivo calcium expression in AP would significantly alter following TSD by the use of time-of-flight secondary ion mass spectrometry (TOF-SIMS) and calretinin (a specific calcium sensor protein in AP neurons) immunohistochemistry. The results indicated that in normal rats, the calcium intensity was estimated to be 0.5 × 105 at m/z 40.08. However, following TSD, the intensity for calcium ions was greatly increased to 1.2 × 105. Molecular imaging revealed that after TSD, various strongly expressed calcium signals were distributed throughout AP with clear identified profiles instead of randomly scattered within this region in normal rats. Immunohistochemical staining corresponded well with ionic image in which a majority of calcium-enriched gathering co-localized with calretinin positive neurons. The functional significance of TSD-induced calcium augmentation was demonstrated by increased heart rate and mean arterial pressure, clinical markers for cardiovascular dysfunction. Considering AP-mediated sympathetic activation is important for cardiovascular regulation, exaggerated calcium influx in AP would render this neurocircuitry more vulnerable to over-excitation, which might serve as the underlying mechanism for the development of TSD-relevant cardiovascular deficiency. 相似文献
995.
Using lattice models we explore the factors that determine the tendencies of polypeptide chains to aggregate by exhaustively sampling the sequence and conformational space. The morphologies of the fibril-like structures and the time scales (τ(fib)) for their formation depend on a balance between hydrophobic and Coulomb interactions. The extent of population of an ensemble of N* structures, which are fibril-prone structures in the spectrum of conformations of an isolated protein, is the major determinant of τ(fib). This observation is used to determine the aggregating sequences by exhaustively exploring the sequence space, thus providing a basis for genome wide search of fragments that are aggregation prone. 相似文献
996.
Nano-structured TiO2/carbon clusters/Cr2O3 composite material has been successfully obtained by the microwave treatment of a TiO(acac)/Cr(acac)3/epoxy resin complex. The compositions of the composite materials were determined using ICP, elemental analysis and surface characterization by SEM-EDX, TEM and XRD. ESR spectral examinations suggest the possibility of an electron transfer in the process of TiO2 → carbon clusters → Cr2O3 with an oxidation site at TiO2 particles and a reduction site at Cr2O3 particles. The preliminary experimental results show that the calcined materials could decompose methylene blue under visible-light irradiation. 相似文献
997.
Fritz John and Karush–Kuhn–Tucker necessary conditions for local LU-optimal solutions of the constrained interval-valued optimization problems involving inequality, equality and set constraints in Banach spaces in terms of convexificators are established. Under suitable assumptions on the generalized convexity of objective and constraint functions, sufficient conditions for LU-optimal solutions are given. The dual problems of Mond–Weir and Wolfe types are studied together with weak and strong duality theorems for them. 相似文献
998.
Wei-Tao Dou Fugui Xu Chen-Xi Xu Jie Gao Hong-Bo Ru Xiangfeng Luan Jiacheng Zhang Ling Zhu Adam C. Sedgwick Guo-Rong Chen Yi Zang Tony D. James He Tian Jia Li Yiyong Mai Xiao-Peng He 《Chemical science》2021,12(33):11089
Triple negative breast cancer (TNBC) is one of the most malignant subtypes of breast cancer. Here, we report the construction of graphene nanoribbon (GNR)-based supramolecular ensembles with dual-receptor (mannose and αvβ3 integrin receptors) targeting function, denoted as GNR-Man/PRGD, for targeted photothermal treatment (PTT) of TNBC. The GNR-Man/PRGD ensembles were constructed through the solution-based self-assembly of mannose-grafted GNRs (GNR-Man) with a pyrene-tagged αvβ3 integrin ligand (PRGD). Enhanced PTT efficacies were achieved both in vitro and in vivo compared to that of the non-targeting equivalents. Tumor-bearing live mice were administered (tail vein) with GNR-Man/PRGD and then each mice group was subjected to PTT. Remarkably, GNR-Man/PRGD induced complete ablation of the solid tumors, and no tumor regrowth was observed over a period of 15 days. This study demonstrates a new and promising platform for the development of photothermal nanomaterials for targeted tumor therapy.Dual receptor-targeting supramolecular glycomaterials are constructed based on graphene nanoribbons for the targeted photothermal therapy of triple-negative breast cancer in vivo. 相似文献
999.
Let X be a compact metric space, and Homeo(X) be the group consisting of all homeomorphisms from X to X. A subgroup H of Homeo(X) is said to be transitive if there exists a point x∈X such that {k(x):k∈H} is dense in X. In this paper we show that, if X=G is a connected graph, then the following five conditions are equivalent: (1) Homeo(G) has a transitive commutative subgroup; (2) G admits a transitive Z2-action; (3) G admits an edge-transitive commutative group action; (4) G admits an edge-transitive Z2-action; (5) G is a circle, or a k-fold loop with k?2, or a k-fold polygon with k?2, or a k-fold complete bigraph with k?1. As a corollary of this result, we show that a finite connected simple graph whose automorphism group contains an edge-transitive commutative subgroup is either a cycle or a complete bigraph. 相似文献
1000.
We introduce a new and general notion of canonical extension for algebras in the algebraic counterpart of any finitary and congruential logic S. This definition is logic-based rather than purely order-theoretic and is in general different from the definition of canonical extensions for monotone poset expansions, but the two definitions agree whenever the algebras in are based on lattices. As a case study on logics purely based on implication, we prove that the varieties of Hilbert and Tarski algebras are canonical in this new sense. 相似文献