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771.
Young-Rae Lee Eun-Mi Noh Eun-Yong Jeong Seok-Kweon Yun Young-Ju Jeong Jong-Hyeon Kim Kang-Beom Kwon Byeong-Soo Kim Sung-Ho Lee Chang-Sik Park Jong-Suk Kim 《Experimental & molecular medicine》2009,41(8):548-554
Cordycepin (3''-deoxyadenosine) has been shown to exhibit many pharmacological activities, including anti-cancer, anti-inflammatory, and anti-infection activities. However, the anti-skin photoaging effects of cordycepin have not yet been reported. In the present study, we investigated the inhibitory effects of cordycepin on matrix metalloproteinase-1 (MMP-1) and -3 expressions of the human dermal fibroblast cells. Western blot analysis and real-time PCR revealed cordycepin inhibited UVB-induced MMP-1 and -3 expressions in a dose-dependent manner. UVB strongly activated NF-κB activity, which was determined by IκBα degradation, nuclear localization of p50 and p65 subunit, and NF-κB binding activity. However, UVB-induced NF-κB activation and MMP expression were completely blocked by cordycepin pretreatment. These findings suggest that cordycepin could prevent UVB-induced MMPs expressions through inhibition of NF-κB activation. In conclusion, cordycepin might be used as a potential agent for the prevention and treatment of skin photoaging. 相似文献
772.
To identify genes that are modulated under cold-stress conditions in the earthworm Eisenia andrei, we performed a genome-wide analysis of gene expression in cold-shocked earthworms by using Serial Analysis of Gene Expression (SAGE). We identified 5,977 and 5,407 unique SAGE tags under normal and cold-stressed conditions, respectively. The majority of the SAGE tags did not match to any known expressed sequences, due to a paucity of expression data in earthworms. We converted the statistically significant SAGE tags for the cold-stressed condition into expressed sequence tags (ESTs), and the results showed that particular genes associated with energy homeostasis, cellular defense mechanisms, and ion balance were up-regulated or down-regulated. We constructed a regulatory network of some of these genes and identified rps-6 as a core gene in the cold-response regulatory-gene network. Our data provide a baseline for gene expression studies of cold shock in the Lumbricidae. 相似文献
773.
Guo Nan Yin Do-Kyun Kim Ji In Kang Yebin Im Dong Sun Lee Ah-reum Han Jiyeon Ock Min-Ji Choi Mi-Hye Kwon Anita Limanjaya Saet-Byel Jung Jimin Yang Kwang Wook Min Jeongwon Yun Yongjun Koh Jong-Eun Park Daehee Hwang Jun-Kyu Suh Ji-Kan Ryu Ho Min Kim 《Experimental & molecular medicine》2022,54(5):626
Diabetes mellitus (DM) is a chronic metabolic disorder characterized by inappropriate hyperglycemia, which causes endothelial dysfunction and peripheral neuropathy, ultimately leading to multiple complications. One prevalent complication is diabetic erectile dysfunction (ED), which is more severe and more resistant to treatment than nondiabetic ED. The serum glycoprotein leucine-rich ɑ-2-glycoprotein 1 (LRG1) is a modulator of TGF-β-mediated angiogenesis and has been proposed as a biomarker for a variety of diseases, including DM. Here, we found that the adhesion GPCR latrophilin-2 (LPHN2) is a TGF-β-independent receptor of LRG1. By interacting with LPHN2, LRG1 promotes both angiogenic and neurotrophic processes in mouse tissue explants under hyperglycemic conditions. Preclinical studies in a diabetic ED mouse model showed that LRG1 administration into the penile tissue, which exhibits significantly increased LPHN2 expression, fully restores erectile function by rescuing vascular and neurological abnormalities. Further investigations revealed that PI3K, AKT, and NF-κB p65 constitute the key intracellular signaling pathway of the LRG1/LPHN2 axis, providing important mechanistic insights into LRG1-mediated angiogenesis and nerve regeneration in DM. Our findings suggest that LRG1 can be a potential new therapeutic option for treating aberrant peripheral blood vessels and neuropathy associated with diabetic complications, such as diabetic ED.Subject terms: Biological therapy, Cytokines, Recombinant protein therapy, Extracellular signalling molecules 相似文献
774.
Choi Hanna Lee Chung-Mo Koh Dong Chan Yoon Yoon Yeol 《Journal of Radioanalytical and Nuclear Chemistry》2021,330(2):397-412
Journal of Radioanalytical and Nuclear Chemistry - Groundwater in the Geum River basin is a major agricultural and domestic water resource. In the present study, we collected 128 groundwater... 相似文献
775.
The effect of synthesis method on the ultimate properties of copper-based catalysts supported on KIT-6 was investigated. A series of catalysts with 0.60Cu/0.15ZnO/0.05MnO/1.0KIT-6 mole ratio was synthesized using three methods, i.e. citric acid impregnation (CA), wet impregnation (WI), and deposition-precipitation (DP). Characterization study shows the catalyst synthesized using CA method had relatively high metal-support interactions and preserved the structures of preshaped KIT-6 support the best. The CA catalyst was also characterized with low mesopore plugging, high porosity, along with the formation of small copper crystallites and large copper surface areas. The presence of abundant accessible active sites in CA catalyst is strongly supported by temperature-programmed desorption results. After reaction, X-ray diffraction analysis indicates CA catalyst had greatest resistance to copper crystallite growth. In direct CO2 hydrogenation reaction, the CA catalyst led to remarkably high methanol production rate (3.94 kg/kgcat·h), i.e. 34%–164% higher than the others, including a commercial catalyst. 相似文献
776.
Dr. Yi Wei Dr. Quanquan Wang Prof. Dr. Ming Joo Koh 《Angewandte Chemie (International ed. in English)》2023,62(5):e202214247
C-Alkyl glycosides and glycoproteins exist in natural products and are prized for their role as carbohydrate mimics in drug design. However, a practical strategy that merges glycosyl donors with readily accessible reagents, derived from abundant carboxylic acid and amine feedstocks, is yet to be conceived. Herein, we show that a nickel catalyst promotes C−C coupling between glycosyl halides and aliphatic acids or primary amines (converted into redox-active electrophiles in one step), in the presence of Hantzsch ester and LiI (or Et3N) under blue LED illumination to deliver C-alkyl glycosides with high diastereoselectivity. Mechanistic studies support the photoinduced formation of alkyl radicals that react with a glycosyl nickel species generated in situ to facilitate cross-coupling. Through this manifold, innate CO2H and NH2 motifs embedded within amino acids and oligopeptides are selectively capped and functionalized to afford glycopeptide conjugates through late-stage glycosylation. 相似文献
777.
The synthesis and isolation of the first examples of a tetraselenolane and a hexaselenepane, obtained from the reaction of a bissilylcarbenoid (RSi2CBrLi; RSi=SiMePh2) with elemental selenium, is reported. The molecular structures of these cyclic polyselenides were determined using single-crystal X-ray diffraction analysis. The selective synthesis of these polyselenides was achieved by controlling the reaction temperature. Stoichiometric deselenation of the hexaselenepane with triphenylphosphine afforded the corresponding tetraselenolane in quantitative yield. Further deselenation of the tetraselenolane with excess triphenylphosphine did not furnish the expected selenoketone but the diselenirane, as confirmed by spectroscopic analysis. 相似文献
778.
Koh‐hei Nitta 《Macromolecular Symposia》2001,170(1):311-319
In this work, a molecular model is proposed to account for the stress‐strain relationships of spherulitic polymers. To describe the yielding behavior of spherulitic polymers, we introduced a new structural unit, i.e. the lamellar cluster, which is represented by several stacked lamellae bound by some tie molecules. It was shown that the tie molecules between the adjacent lamellar clusters produce the concentrated load acting on the cluster surface, leading to bending deformation of the lamellar cluster. The yielding behavior was explained by the disintegration of lamellar cluster due to the bending deformation. 相似文献
779.
The structure ofS the title complex [Co. L. (H2O)3]n. nH2O. 0.2 nH2O has been established by single crystal X-ray diffraction. Crystals of the complex are monoclinic, space group C2/c with cell constants α = 45.29(4), b=10.631(6), c = 8.015(6) Å, β = 90.65(8)°, Z = 8, Dc = 1.489 g. cm−3 The structure was solved and refined to R =0.0478 (wR = 0.0577). In the chain structure, Co(II) ions are hexacoordinated by 0 atoms in an octahedral arrangement. CoO6 octahedra share corners (bridged) through O atoms of water, with each L2--ligand binding two adjacent Co atoms. 相似文献
780.
Si1-xGex mixed crystals with 5 at% Ge concentration have been grown by the pulling-down technique using a crucible with multi-capillary channels. The unique feature of the technique is that Ge solute concentration of the small molten zone is maintained constant due to the condition of no back diffusion of solute through the capillary channels, and that the diffusion-controlled solute transport causes the effective distribution coefficient to be unity. The Ge concentration was measured by the electron probe microanalysis and observed to be homogeneous along both the longitudinal and radial directions. The two-dimensional distribution on the whole cross section was also found to be uniform. 相似文献