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1.
Heliyon ; 6(8): e04618, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32904262

ABSTRACT

Multi-omics analyses, combining transcriptomics, genomics, proteomics, and so on, have led to important insights in many areas of biology and medicine. To support these analyses, software that can handle the difficulties associated with multi-omics datasets is crucial. Here, we describe Panomicon, a web-based, interactive analysis environment for multi-omics data. Building on Toxygates, a tool previously created to study single-omics data that features interactive clustering, heatmaps, and user data uploads, Panomicon introduces improvements for the storage and handling of additional omics types, as well as tools for the generation and visualization of interaction networks between different types of omics data. Panomicon is a new type of environment for the collaborative study of multi-omics data, both for users uploading data to our server and for groups wishing to host their own deployment of Panomicon. We demonstrate Panomicon's capabilities by revisiting a microRNA-mRNA interaction networks study in a non-small cell lung cancer dataset.

2.
Opt Express ; 25(24): 30304-30311, 2017 Nov 27.
Article in English | MEDLINE | ID: mdl-29221060

ABSTRACT

Electrically tunable metasurfaces have gained special interest as they can realize ultrathin surface-normal modulators in planar geometries. In this paper, we demonstrate a novel metasurface modulator based on electro-optic (EO) polymer that utilizes bimodal resonance inside a metallic subwavelength grating to increase the modulation efficiency. When two metal-insulator-metal (MIM) resonant modes are excited simultaneously inside the grating, they couple strongly to generate a sharp dip in the reflected spectrum. As a result, efficient intensity modulation with 15-dB extinction ratio can be obtained at the resonant wavelength under a small refractive index change of 8.5 × 10-3, corresponding to modulation voltage of less than 10 V. Due to the low parasitic capacitance of EO polymer and high conductivity of metallic gratings which is also used as the electrodes, the RC bandwidth of the device should easily exceed 100 GHz, potentially applicable to high-speed surface-normal modulators.

3.
Org Lett ; 10(15): 3191-4, 2008 Aug 07.
Article in English | MEDLINE | ID: mdl-18582068

ABSTRACT

The direct and catalytic kinetic resolution of racemic carboxylic acids bearing a Brønsted base such as O-protected alpha-hydroxy carboxylic acids and N-protected alpha-amino acids has been accomplished through an L-histidine-derived sulfonamide-induced enantioselective esterification reaction with tert-butyl alcohol for the first time. Highly asymmetric induction [S( k fast/ k slow) = up to 56] has been achieved under the equilibrium between a chiral catalyst and two diastereomeric acylammonium salts through an intramolecular hydrogen-bonding interaction.

4.
Org Lett ; 10(11): 2187-90, 2008 Jun 05.
Article in English | MEDLINE | ID: mdl-18442240

ABSTRACT

The exothermic reaction of 3,5-bis(trifluoromethyl)phenyl or 4-nitrophenyl isothiocyanate with 4-pyrrolidinopyridine (PPY) gave the corresponding arylaminothiocarbonylpyridinium salts in quantitative yields. These novel zwitterionic salts were effective as organocatalysts for the transesterification reaction of an equimolar mixture of methyl carboxylates and alcohols in hydrocarbons such as heptane and octane under azeotropic reflux conditions with the removal of methanol. In sharp contrast, PPY was inert as a catalyst under the same reaction conditions.

5.
J Am Chem Soc ; 129(47): 14775-9, 2007 Nov 28.
Article in English | MEDLINE | ID: mdl-17983230

ABSTRACT

With regard to atom economy and E-factor, catalytic condensation of carboxylic acids with equimolar amounts of alcohols is the most desirable. Although several highly active dehydration catalysts have been reported, more efficient alternatives are still strongly needed because the dehydrative esterification of tertiary alcohols, phenols, acid-sensitive alcohols, amino acids, and hardly soluble alcohols has never proceeded satisfactorily. Here we report new insights into the classical DMAP-catalyzed acylation of alcohols: surprisingly, only a 0.05-2 mol % of DMAP can efficiently promote acylation of alcohols with acid anhydrides under auxiliary base- and solvent-free conditions to give the corresponding esters in high yields. Furthermore, we achieved the recovery and reuse of commercially available polystyrene-supported DMAP without using any solvents. These serendipitous findings provide widely useful and environmentally benign esterification methods, which might be more practical and reliable than catalytic dehydrative condensation methods, in particular, for the less reactive alcohols which hardly condense with carboxylic acid directly.

7.
J Am Chem Soc ; 126(39): 12212-3, 2004 Oct 06.
Article in English | MEDLINE | ID: mdl-15453723

ABSTRACT

This communication describes the rational design of an l-histidine-derived minimal artificial acylase. Our new artificial acylase, tert-butyldiphenylsilyl ether of N-(2,4,6-triisopropylbenzenesulfonyl)-pi(Me)-l-histidinol, is a simple and small molecule (molecular weight = 660) that contains only one chiral carbon center that originates from natural l-histidine. The kinetic acylation of racemic secondary alcohols induced by this compound showed an S (kfast/kslow) value of up to 93. A reusable polystyrene-bound artificial acylase was also developed to examine its practical usability.


Subject(s)
Alcohols/isolation & purification , Amidohydrolases/chemistry , Histidine/analogs & derivatives , Acylation , Alcohols/chemistry , Amidohydrolases/chemical synthesis , Catalysis , Crystallography, X-Ray , Histidine/chemistry , Imidazoles/chemical synthesis , Imidazoles/chemistry , Kinetics , Protein Structure, Secondary , Pyridines/chemical synthesis , Pyridines/chemistry , Stereoisomerism
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