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1.
J Med Chem ; 63(3): 1233-1244, 2020 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-31939669

RESUMO

Human hand, foot, and mouth disease (HFMD) is a serious public health threat with high infection rates in children and infants who reside in Asia and the Pacific regions, and no effective drugs are currently available. Enterovirus 71 (EV71) and coxsackievirus A16 are the major etiological pathogens. Based on an essential hydrophobic pocket on the viral capsid protein VP1, we designed and synthesized a series of small molecular weight compounds as inhibitors of EV71. A potential drug candidate named NLD-22 exhibited excellent antiviral activity (with an EC50 of 5.056 nM and a 100% protection rate for mice at a dose of 20 mg/kg) and low toxicity. NLD-22 had a favorable pharmacokinetic profile. High-resolution cryo-electron microscopy structural analysis confirmed NLD-22 bound to the hydrophobic pocket in VP1 to block viral infection. In general, NLD-22 was indicated to be a promising potential drug candidate for the treatment of HFMD.

2.
ACS Appl Mater Interfaces ; 11(49): 46124-46131, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31714736

RESUMO

Photonic shape memory (SM) polymers based on liquid crystalline blue phase (BP) films have been fabricated by self-assembly and subsequent photopolymerization of liquid-crystal mixtures. These freestanding BP films exhibit narrow photonic band gaps and high reflectivity in the visible wavelength range. Multiple blue-shift colors are achieved by SM programming process at different mechanical pressures. The blue-shift colors can be attributed to a decrease of effective BP pitch along the viewing direction caused by the compressed deformation of the BP films, which are confirmed by a three-dimensional interometric profile. The deformed BP films can recover to their original shapes and reflecting colors by heating the polymer films to temperatures above the glass-transition temperature. Quantitative relationships between the shape change and optical response are established for understanding this SM effect. What is more, the temporary photonic patterns can be reversibly written and erased for dozens of cycles without apparent degradation, making these freestanding BP films appealing as rewritable photonic papers and optical sensors.

3.
Nanotechnology ; 30(3): 035705, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30444728

RESUMO

Near-infrared absorbing dyes are catching people's attention as they are committed to find materials with greater photoacoustic (PA) and photothermal (PT) effect. In this study, a new series of organic π-conjugated discotic derivatives synthesized via [2 + 2] click chemistry were introduced. The PA intensity and PT conversion effect of the derivatives were monitored. It was found that the π-conjugated discotic derivatives had a proper absorption peak and PA intensity by introducing the click regents. Furthermore, the PA intensity remained relatively high, while B12 molecules were embedded in hydrophobic phospholipid bilayer of liposomes (B12⊂L). The application in biological therapy for tumors become possible as the toxicity of B12⊂L was low. What's more, when B12 molecules embedded in poly (N-isopropylacrylamide)-block-poly (2-nitrobenzyl methacrylate) (PNIPAM-b-PNBM) thermosensitive micelles were irradiated by laser, the molecules could take the place of direct temperature stimulus. This work affords us a way to solve the problem in which direct temperature stimulus is inapplicable.

4.
Nanoscale ; 10(29): 14220-14229, 2018 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-30009308

RESUMO

We have demonstrated a facile and low-cost approach for the fabrication of binary "island" shaped arrays (BISA) with high-density hot spots as reproducible surface-enhanced Raman scattering (SERS) substrates by depositing a self-assembled monolayer Au nanoparticle (AuNP) film with small gaps onto a two-dimensional (2D) silica microsphere opal structure. By varying the size of silica spheres, the SERS performance of the BISA substrate with an enhancement factor (EF) of 3.74 × 1010 magnitude and the corresponding signal intensity deviation of below 8% using 770 nm silica sphere arrays were achieved. Compared with the assembled monolayer AuNP film on a planar substrate, the BISA enabled the installation of more AuNPs as a source of hot spots due to the undulation of morphology on the nanoscale within the designated laser-illumination area. In addition, a finite-difference time-domain (FDTD) simulation suggested that the BISA structure provided geometric conditions for increasing the intensity of the formed hot spots, and the strong periodic electric fields on the BISA are located not only in the gap between adjacent AuNPs, but also along the boundary of the neighboring island of silica spheres. Surface plasmon-decayed hot carriers (hot electrons and hot holes) from AuNPs can be applied in the field of energy conversion (i.e., photocatalysis), integrated with the SERS as a sensitive optical indicator to accurately monitor the catalytic reaction process. Furthermore, we examined the catalytic reaction process of the dimerization of 4-ATP into DMAB and found that photocatalytic activity could be tuned by changing the size of silica spheres. This study provides a new design route for the fabrication of the SERS platform with high sensitivity and reproducibility to detect molecules or improve catalyst efficiency.

5.
Soft Matter ; 14(27): 5547-5553, 2018 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-29964287

RESUMO

A reversible solvent-sensitive actuator with a continuous bending/debending process is fabricated by over-infiltration of liquid crystal monomers into a colloidal template and subsequent photopolymerization. The fabricated actuator exhibits a maximum bending angle of 1080° in 1.58 s in dichloromethane, accompanied with successive debending in 0.32 s. The behavior of the actuator can be modulated by changing the solvent type, film thickness/length and molar ratio of A6OCB/C6M. This study will provide an important experimental and theoretical basis for the development of novel actuators.

6.
Phys Chem Chem Phys ; 19(3): 2353-2358, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-28054693

RESUMO

In this study, we demonstrate a novel method for fabricating polymer stabilized cholesteric liquid crystal (PSCLC) films with non-uniform pitch distribution by utilizing two kinds of photo-induced processes. Based on the large HTP temperature dependence of a chiral dopant, polymer networks were formed at two distant temperature points in sequence. The influence of the polymerization conditions on the reflectance properties of PSCLCs before and after polymerization was investigated. The results strongly suggest that the location and bandwidth of the reflection band can be controlled preferably by adjusting the ultraviolet light intensity and irradiation time of UV-light. In addition, the morphology of the polymer network in the composites was studied using scanning electron microscopy (SEM). A general correlation between polymerization conditions, the network morphology, and the reflective region will be outlined.

7.
Phys Chem Chem Phys ; 18(42): 29028-29032, 2016 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-27752664

RESUMO

The magnetic Fe3O4 nanoparticle-doped blue phase liquid crystal (BPLC) was found to have a relatively strong contrast ratio in magnetic-addressed display performance compared to the composites in other phases; this is a new application of the BPLC and a way to prepare a new type of power-free magnetically-driven LC flexible display.

8.
ChemistryOpen ; 5(1): 71-7, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27308215

RESUMO

Recently, third-order nonlinear properties of porphyrins and porphyrin polymers and coordination compounds have been extensively studied in relation to their use in photomedicine and molecular photonics. A new functionalized porphyrin dye containing electron-rich alkynes was synthesized and further modified by formal [2+2] click reactions with click reagents tetracyanoethylene (TCNE) and 7, 7, 8, 8-tetracyanoquinodimethane (TCNQ). The photophysical properties of these porphyrin dyes, as well as the click reaction, were studied by UV/Vis spectroscopy. In particular, third-order nonlinear optical properties of the dyes, which showed typical d-π-A structures, were characterized by Z-scan techniques. In addition, the self-assembly properties were investigated through the phase-exchange method, and highly organized morphologies were observed by scanning electron microscopy (SEM). The effects of the click post-functionalization on the properties of the porphyrins were studied, and these functionalized porphyrin dyes represent an interesting set of candidates for optoelectronic device components.

9.
Phys Chem Chem Phys ; 18(10): 7341-8, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26899312

RESUMO

A novel kind of monodonor-bisacceptor (D-A-A) C60 charge-transfer complex was synthesized by the high-yielding [2+2] click chemistry reaction and the Prato reaction. Both electrochemical and UV-vis spectra studies were carried out and they proved that the side groups of the fullerene derivatives played an important role in the energy gaps, and also affected the third-order non-linear optical response. The experimental investigation on the third-order non-linear optical phenomena of the fullerene derivatives was measured using the Z-scan technique at different wavelengths (532 nm and 1064 nm). All the compounds exhibited very special non-linear optical properties when pumped by 21 ps pulses at 532 nm which suggested that there were two different types of reversible photo-isomerization. The optical-limiting performance has also been studied which proved indirectly the mechanism models of the reversible photo-isomerization.

10.
Chemphyschem ; 15(16): 3523-9, 2014 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-25155781

RESUMO

A series of functionalized porphyrin molecules containing electron-rich alkynes, synthesized by means of the Sonogashira coupling reaction were further modified by reacting the ethynyl groups with click reagent through a formal [2+2] click reaction. The photophysical and electrochemical properties of the porphyrin derivatives were studied by UV/Vis spectroscopy and cyclic voltammetry. We show that the optoelectronic properties are affected by the click reagent groups and central metal ions. The functionalized porphyrin molecules show strong charge-transfer (CT) bands in the visible region (near-IR region) and potent redox activities. Through a phase-exchange self-assembly method, the highly organized morphologies were observed by scanning electron microscopy (SEM). The functionalized porphyrin molecules represent an interesting set of candidates for optoelectronic device components. The effect of the metal ions or click reagent groups on the self-assembly properties were also studied by the UV/Vis spectroscopic titration experiments.

11.
Phys Chem Chem Phys ; 16(12): 5622-6, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24514264

RESUMO

Novel cinnamic-acid-derived H-bonded liquid crystals with enantiotropic BP*s were facilely prepared. When simply modifying the donor-acceptor ratio, the proportion of (S)-4-(2-octanyloxy) cinnamic acid to 4-(4-propylcyclohexyl) phenyl isonicotinate, the generated BP temperature ranges were consequentially extended with the widest range of about 10 °C, which is seldom found in enantiotropic BP materials. The optimized results of density-functional-theory calculations show that cinnamic-acid-derived mesogens have a bent shape and thus could be beneficial to stabilize enantiotropic blue phases.

12.
Chem Commun (Camb) ; 50(6): 691-4, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24286108

RESUMO

A chiral nematic liquid crystal-photopolymerizable monomer-chiral azobenzene compound composite was prepared and then polymerized under UV irradiation. The reflection wavelength of the composite can be extended to cover the 1000-2400 nm range and also be adjusted to the visible light region by controlling the concentration of chiral compounds.

13.
Chem Commun (Camb) ; 49(86): 10097-9, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-24045847

RESUMO

A new series of azobenzene-dimers were synthesized and doped into the blue phase liquid crystals to broaden the temperature range of BPs. It is found that not only can the reflection wavelength of BPI be reversibly controlled but BPI can also be transformed into the cholesteric phase owing to isomerization of azobenzene induced by light.

15.
Phys Chem Chem Phys ; 12(7): 1436-9, 2010 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-20126755

RESUMO

In this communication, we describe a simple process for the generation of surface relief gratings (SRG). SRG are fabricated from a photocross-linkable organic monomer PDACE (4-propyldiphenylacetylenecarboxylic acid cinnamyl ester) with cinnamyl ester and tolane groups, by using a patterned non-polarized UV light irradiation. The patterns of the surface relief structures can be easily controlled and the modulation depth can reach 130 nm. Moreover, it is interestingly observed that the photopolymer of the SRG exhibits distinctive characteristics including homeotropic orientation and fluorescence properties as a result of the photocross-linking of the dual photoreactive groups of PDACE. Finally, the mechanism of fabrication of SRG from PDACE is discussed with mean-field theory.

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