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| 2. |
- Wang, Ying, et al.
(författare)
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Asymmetric oxidation of sulfides with H2O2 catalyzed by titanium complexes of Schiff bases bearing a dicumenyl salicylidenyl unit
- 2011
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Ingår i: Applied organometallic chemistry. - : Wiley. - 0268-2605 .- 1099-0739. ; 25:5, s. 325-330
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Tidskriftsartikel (refereegranskat)abstract
- The sterically hindered Schiff bases (L-3-L-5), prepared from 3,5-dicumenyl salicylaldehyde and chiral amino alcohols, were used in combination with Ti(OiPr)(4) for asymmetric oxidation of aryl methyl sulfides with H2O2 as terminal oxidant. Among the ligands L-3-L-5, L-4 with a tert-butyl group in the chiral carbon of the amino alcohol moiety gave the best result with 89% yield and 73% ee for the sulfoxidation of thioanisole under optimal conditions [with 1 mol% of Ti(OiPr)(4) in a molar ratio of 100 : 1 : 1.2 : 120 for sulfide : Ti(OiPr)(4) : ligand : H2O2 in CH2Cl2 at 0 degrees C for 3 h]. The reaction afforded good yield (84%) with a moderate enantioselectivity (62% ee) even with a lower catalyst loading from 1.0 to 0.5 mol%. The oxidations of methyl 4-bromophenyl sulfide and methyl 4-methoxyphenyl sulfide with H2O2 catalyzed by the Ti(OiPr)(4)-L-4 system gave 79-84% yieldsand54-59% ee of the corresponding sulfoxides in CH2Cl2 at 20 degrees C. The chiral induction capability of the cumenyl-modified sterically hindered Schiff bases for sulfoxidation was compared with the conventional Schiff bases bearing tert-butyl groups at the 3,5-positions of the salicylidenyl unit.
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| 3. |
- Wang, Ying, et al.
(författare)
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Highly enantioselective sulfoxidation with vanadium catalysts of Schiff bases derived from bromo- and iodo-functionalized hydroxynaphthaldehydes
- 2010
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Ingår i: Journal of Catalysis. - : Elsevier BV. - 0021-9517 .- 1090-2694. ; 273:2, s. 177-181
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Tidskriftsartikel (refereegranskat)abstract
- Two series of chiral Schiff bases, 4a-e and 5a-e, prepared from the condensation of the mono-, di-, trib-romohydroxynaphthaldehyde or monoiodohydroxynaphthaldehyde with chiral amino alcohols, were used in combination with VO(acac)(2) for the asymmetric oxidation of aryl methyl sulfides using H2O2 as terminal oxidant. Among these Schiff bases, dibromo-functionalized 4d and iodo-functionalized 5e gave high yields (91-93%) with good enantioselectivities (80-82% ee) for the oxidation of thioanisole in dichloromethane. The asymmetric oxidation of thioanisole in toluene using these Schiff bases gave methyl phenyl sulfoxide in satisfactory isolated yields (48-62%) with high enantioselectivities (91-94% ee), which were further improved by a modified procedure with the ee value up to 98% in 62% yield. The oxidations of other aryl methyl sulfides in toluene with dibromo- and iodo-functionalized Schiff bases 5d and 5e as ligands using the modified procedure afforded the corresponding sulfoxides in 55-67% isolated yields with 95-99% ee. (C) 2010 Elsevier Inc. All rights reserved.
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| 4. |
- Zhao, Li-Juan, et al.
(författare)
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Lysine demethylase LSD1 delivered via small extracellular vesicles promotes gastric cancer cell stemness
- 2021
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Ingår i: EMBO Reports. - : EMBO. - 1469-221X .- 1469-3178. ; 22:8
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have examined the functions of nucleic acids in small extracellular vesicles (sEVs). However, much less is known about the protein cargos of sEVs and their functions in recipient cells. This study demonstrates the presence of lysine-specific demethylase 1 (LSD1), which is the first identified histone demethylase, in the culture medium of gastric cancer cells. We show that sEVs derived from gastric cancer cells and the plasma of patients with gastric cancer harbor LSD1. The shuttling of LSD1-containing sEVs from donor cells to recipient gastric cancer cells promotes cancer cell stemness by positively regulating the expression of Nanog, OCT4, SOX2, and CD44. Additionally, sEV-delivered LSD1 suppresses oxaliplatin response of recipient cells in vitro and in vivo, whereas LSD1-depleted sEVs do not. Taken together, we demonstrate that LSD1-loaded sEVs can promote stemness and chemoresistance to oxaliplatin. These findings suggest that the LSD1 content of sEV could serve as a biomarker to predict oxaliplatin response in gastric cancer patients.
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| 5. |
- Fan, Liangdong, 1985-, et al.
(författare)
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High performance transition metal oxide composite cathode for low temperature solid oxide fuel cells
- 2012
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 203:1, s. 65-71
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Tidskriftsartikel (refereegranskat)abstract
- Low temperature solid oxide fuel cells (SOFCs) with metal oxide composite cathode on the ceria–carbonate composite electrolyte have shown promising performance. However, the role of individual elements or compound is seldom investigated. We report here the effect of the ZnO on the physico-chemical and electrochemical properties of lithiated NiO cathode. The materials and single cells are characterized by X-ray diffraction, scanning electron microscopy, DC polarization electrical conductivity, electrochemical impedance spectroscopy and fuel cell performance. The ZnO modified lithiated NiO composite materials exhibit smaller particle size and lower electrical conductivity than lithiated NiO. However, improved electro-catalytic oxygen reduction activity and power output are achieved after the ZnO modification. A maximum power density of 808 mW cm−2 and the corresponding interfacial polarization resistance of 0.22 Ω cm2 are obtained at 550 °C using ZnO modified cathode and 300 μm thick composite electrolyte. The single cell keeps reasonable stability over 300 min at 500 °C. Thus, ZnO modified lithiated NiO is a promising cathode candidate for low temperature SOFCs.
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| 6. |
- Liu, Haibin, et al.
(författare)
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Asymmetric oxidation of sulfides with hydrogen peroxide catalyzed by a vanadium complex of a new chiral NOO-ligand
- 2009
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Ingår i: Catalysis communications. - : Elsevier BV. - 1566-7367 .- 1873-3905. ; 11:4, s. 294-297
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Tidskriftsartikel (refereegranskat)abstract
- A new chiral NOO-tridentate ligand (8R)-2-(2-hydroxyphenyl)-4-methyl-5,6,7.8-tetrahydro-quinolin-8-ol (1) bearing a rigid tetrahydroquinoline framework was prepared and applied in the vanadium-catalyzed asymmetric oxidation of aryl methyl sulfides with H2O2 as oxidant. Less toxic acetone was found to be the proper solvent for the enantioselective oxidation of sulfides. Under the optimal condition, the asymmetric oxidation of aryl methyl sulfides in acetone catalyzed by VO(acac)(2)/1 at 0 degrees C gives good to high yields (80-95%) of sulfoxides with enantioselectivity up to 77% ee.
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| 7. |
- Liu, Hai-Bin, et al.
(författare)
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Synthesis of Tri- and Disalicylaldehydes and Their Chiral Schiff Base Compounds
- 2010
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Ingår i: Synthetic Communications. - : Informa UK Limited. - 0039-7911 .- 1532-2432. ; 40:7, s. 1074-1081
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Tidskriftsartikel (refereegranskat)abstract
- A suitable procedure for convenient preparation of 1,3,5-tris(4-hydroxy-5-formylphenyl)benzene (6) was exploited via 5-bromosalicylaldehyde as starting reactant. Among the obtained products, compound 6, 4-methoxy-3-formylphenylboronic acid (9), 1,3,5-tris(4-methoxy-5-formylphenyl)benzene (10), and 4-methoxy-4'-hydroxyl-3,3'-diformyl-1,1'-diphenyl (11) had not been reported previously. Two new chiral Schiff base ligands, L1 and L2, were obtained from the tri- or disalicylaldehydes.
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| 8. |
- Wang, N., et al.
(författare)
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Catalytic activation of H2 under mild conditions by an [FeFe]-hydrogenase model via an active μ-hydride species
- 2013
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 135:37, s. 13688-13691
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Tidskriftsartikel (refereegranskat)abstract
- A [FeFe]-hydrogenase model (1) containing a chelating diphosphine ligand with a pendant amine was readily oxidized by Fc+ (Fc = Cp 2Fe) to a FeIIFeI complex ([1]+), which was isolated at room temperature. The structure of [1]+ with a semibridging CO and a vacant apical site was determined by X-ray crystallography. Complex [1]+ catalytically activates H2 at 1 atm at 25 C in the presence of excess Fc+ and P(o-tol) 3. More interestingly, the catalytic activity of [1]+ for H2 oxidation remains unchanged in the presence of ca. 2% CO. A computational study of the reaction mechanism showed that the most favorable activation free energy involves a rotation of the bridging CO to an apical position followed by activation of H2 with the help of the internal amine to give a bridging hydride intermediate.
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| 9. |
- Wang, Ying, et al.
(författare)
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Synthesis of New Chiral Schiff Bases Containing Bromo- and Iodo-Functionalized Hydroxynaphthalene Frameworks
- 2011
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Ingår i: Synthetic Communications. - : Informa UK Limited. - 0039-7911 .- 1532-2432. ; 41:9, s. 1381-1393
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Tidskriftsartikel (refereegranskat)abstract
- [image omitted] Two series of chiral Schiff bases 3a-g and 4a-g containing bromo- and iodo-functionalized hydroxynaphthalene frameworks were conveniently prepared in acceptable to moderate yields by controlled halogenation of hydroxynaphthaldehyde and then condensation of the corresponding mono-, di-, and trihalohydroxynaphthaldehyde with the chiral amino alcohol. Except for 4d, the Schiff bases 3a-g, 4a-c, and 4e-g prepared in the present work have not been reported in literature so far, and they might be used as effective chiral inducers in some asymmetrically synthetic reactions.
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| 10. |
- Brownstein, Catherine A., et al.
(författare)
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An international effort towards developing standards for best practices in analysis, interpretation and reporting of clinical genome sequencing results in the CLARITY Challenge
- 2014
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Ingår i: Genome Biology. - : Springer Science and Business Media LLC. - 1465-6906 .- 1474-760X. ; 15:3, s. R53-
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Tidskriftsartikel (refereegranskat)abstract
- Background: There is tremendous potential for genome sequencing to improve clinical diagnosis and care once it becomes routinely accessible, but this will require formalizing research methods into clinical best practices in the areas of sequence data generation, analysis, interpretation and reporting. The CLARITY Challenge was designed to spur convergence in methods for diagnosing genetic disease starting from clinical case history and genome sequencing data. DNA samples were obtained from three families with heritable genetic disorders and genomic sequence data were donated by sequencing platform vendors. The challenge was to analyze and interpret these data with the goals of identifying disease-causing variants and reporting the findings in a clinically useful format. Participating contestant groups were solicited broadly, and an independent panel of judges evaluated their performance. Results: A total of 30 international groups were engaged. The entries reveal a general convergence of practices on most elements of the analysis and interpretation process. However, even given this commonality of approach, only two groups identified the consensus candidate variants in all disease cases, demonstrating a need for consistent fine-tuning of the generally accepted methods. There was greater diversity of the final clinical report content and in the patient consenting process, demonstrating that these areas require additional exploration and standardization. Conclusions: The CLARITY Challenge provides a comprehensive assessment of current practices for using genome sequencing to diagnose and report genetic diseases. There is remarkable convergence in bioinformatic techniques, but medical interpretation and reporting are areas that require further development by many groups.
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