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1.
Adv Mater ; 32(14): e1906319, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32080919

RESUMO

Movement is one of the vital features of living systems, and remote control of bioinspired soft robotic systems in a precise, contactless and harmless way is extremely desirable but challenging. A near-infrared (NIR) photodriven polymeric oscillator is designed and fabricated by selectively coating a mussel-inspired polydopamine (PDA) polymer layer on the surface of splay-aligned liquid crystalline network (LCN) film. The oscillating motions of the LCN oscillators can be facilely manipulated by tuning light intensity and film thickness. More importantly, the programmability of the PDA coating enables the oscillating behaviors of LCN film to be predesignated and finely adjusted by coating the film with PDA locally and repeatedly. The self-oscillating movement mechanism can be attributed to the temperature oscillation at the PDA-coated LCN film since it is alternatively exposed and sheltered to the NIR-light irradiations. Owing to over 50% NIR irradiation in solar spectrum, PDA-coated film is found to oscillate upon exposure of focused sunlight, presenting great potential in fabrication of solar power generation devices. This provides a versatile strategy to fabricate NIR-light-actuated polymeric oscillators, providing inspirations in the development of biological soft robots and advanced biomimetic devices.

2.
Molecules ; 25(3)2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31991746

RESUMO

The development of the economy has increased the demand for anti-counterfeiting technologies, and with the traditional ones becoming known to the public, new and more effective ones are needed. In this study, a series of liquid crystal mixtures containing side-chain liquid crystal polymers and small-molecular-weight liquid crystals (LCs) were designed and prepared. The phase transition behavior and self-assembling structures of the LC mixtures were investigated by a combination of differential scanning calorimetry, polarized optical microscopy, and small-angle X-ray diffraction. The optical properties of the mixture film were characterized with a UV/VIS/IR spectrum study. The results reveal that the obtained film exhibited different optical modes between transparent, scattering, and selective reflection under finger-temperature control. Therefore, by the introduction of a coexisting thermal- or optical-polymer-dispersed network, a liquid crystal composite film with an integration of apparent optical switching modes and enhanced strength and toughness was successfully demonstrated. This research provides a versatile strategy for the design and preparation of liquid crystal anti-counterfeiting materials for practical use. In this study, a prototype finger-temperature-detecting anti-counterfeiting label was prepared, and its temperature-response property was demonstrated.

3.
J Nanosci Nanotechnol ; 20(6): 3598-3603, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31748057

RESUMO

Spray-drying and freeze-drying are effective approaches to improve the long-term stability of nanosuspensions. This research explored the effect of spray-drying and freeze-drying techniques on PVP K30-stabilized silybin nanosuspensions. The morphology was observed by scanning electron microscopy (SEM): The spray-dried sample was spherical, and the freeze-dried samples were rodlike with smooth surfaces. The redispersibility was studied via dynamic light scattering (DLS): The size, PDI, and zeta of the spray-dried sample were 133.27 nm, 0.214, and 24.37 mV, respectively; the size, PDI, and zeta of the freeze-dried sample were 298.70 nm, 0.114, and 20.98 mV, respectively. The in vitro dissolution was studied, and the two dry powders showed a significant increase compared to silybin. The two dried powders had better long-term stability than the liquid starting material. Overall, spray-drying and freeze-drying are appropriate drying methods for the preparation of silybin nanosuspensions with better stability and dissolution velocity.

4.
Ther Adv Respir Dis ; 13: 1753466619890538, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31771432

RESUMO

Autophagy is a process of cell self-renewal that is dependent on the degradation of the cytoplasmic proteins or organelles of lysosomes. Many diseases, such as metabolic diseases, cancer, neurodegenerative diseases, and lung diseases, have been confirmed to be associated with elevated or impaired levels of autophagy. At present, studies have found that autophagy participates in the regulation of chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, pulmonary hypertension, acute lung injury, lung cancer, and other pulmonary diseases. Using recent literature on the signal transduction mechanisms of autophagy and the effects of autophagy signalling on lung diseases, this review intends to clarify the mechanisms of lung disease to guide the treatment of related diseases. The reviews of this paper are available via the supplemental material section.

5.
Angew Chem Int Ed Engl ; 58(20): 6698-6702, 2019 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-30903672

RESUMO

Thiols are prone to react with a multitude of various functional groups in high yields, which has been widely used for surface- and particle-patterning, bioorganic synthesis, polymer modification, imprint nanolithography, the fabrication of optical components, hydrogel synthesis, and the curing of hard protective coatings. In this work, a chiral thiol with a high helical twisting power was synthesized through a novel synthetic route with high selectivity, yield, and cost-effectiveness. It was then used to fabricate a liquid-crystal composite film with ultra-wide broadband reflection via thiol click chemistry. Cholesteric liquid-crystal materials with broadband reflection have many potential applications for broadband polarizers, polarizer-free displays, organic optical data storage media, smart switchable reflective windows, and continuous waveband laser protection.

6.
FEMS Microbiol Lett ; 366(9)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30860574

RESUMO

We assessed the relationship between gut microbiome profile and childhood eczema in 172 subjects (age < 3 years, healthy group N = 123, eczema group N = 49) utilizing 16S rRNA gene sequencing. Lower relative abundance of Bifidobacterium was shown to be associated with childhood eczema. Considering that developmental and environmental factors could modify the state of children's gut microbiome, we divided the samples into four age groups: 0-0.5 years, 0.5-1 years, 1-2 years and 2-3 years for farther analyses. Data revealed significant inter-group differences between healthy and eczema samples in all age groups, and decreased microbial diversity was most significantly found in children with eczema of age 2-3 years old. Decreased abundance of Bifidobacterium was a major finding in eczema groups from 0.5-3 years compared to the age matched healthy controls, but not significant in children younger than 6 month old. Of note, Bifidobacterium operational taxonomic units were identified by Random Forest with highly predictive power of 0.83 (AUC = 0.83) in ROC analysis, which also confirmed its role as a key genus that is associated with eczema. To verify the sequencing results, we performed quantitative polymerase chain reaction of Bifidobacterium and Bacteroides in the same cohort, and in a new eczema cohort (N = 57) for validation. Significantly, lower Bifidobacterium quantities were found in both eczema groups with an age range of 0.5-3 years. These results suggest variations in early gut microbiome are associated with childhood eczema.

7.
Adv Mater ; 31(8): e1806016, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30614564

RESUMO

Orientation control of ordered materials would not only produce new physical phenomenon but also facilitate the development of fancy devices. Discotic liquid crystals (DLCs) form 1D charge transport pathway by self-organizing into columnar nanostructures via π-π stacking. However, controlling the electrical properties in such nanostructures with some direct and instant way is a formidable task for their high viscosity and insensitivity to external stimuli. Herein, the arbitrary control over electrical conductivity of such columnar nanostructures is achieved with UV light by incorporating DLCs with molecular motors. Highly ordered DLC microstripe arrays are generated on desired substrate through a capillary bridge dewetting strategy. The conductivity of the microstripes could be continuously modulated by 365 nm light due to the influence of molecular motion under UV irradiation on the electron orbital overlap of columnar nanostructures. This is so because the disorder degree of the DLC molecules is associated with the intensity of UV light and the doping concentration of molecular motors. Moreover, the device shows memory effect and reversible conductivity change. The DLC microstripe arrays are very promising for the applications in UV detectors, memory devices, optical switches, and so on.

8.
Biomed Pharmacother ; 108: 1141-1151, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30372815

RESUMO

Chronic obstructive pulmonary disease (COPD) is a common disorder of respiratory system. This study aimed to evaluate changes of mature dendritic cells (DCs) and regulatory T cells (Treg) in lung tissues and peripheral blood of COPD patients. For lung tissue analysis, patients were divided into no-smoking and no-COPD (CS-COPD-), smoking and no-COPD (CS + COPD-) and COPD group. For peripheral blood analysis, patients were divided into CS-COPD-, CS + COPD-, stable COPD (SCOPD) and acute exacerbation of COPD (AECOPD) group. Hematoxylin and eosin (HE) staining was used to evaluate inflammation of lung tissues. Immunohistochemistry assay was employed to examine CD80, CCR6, IL-17 A, FoxP3 in lung tissues. DCs and Treg cells were isolated from lung tissues and peripheral blood. Levels of CD80, FoxP3+ Treg, CCR6 and IL-17 A were detected by using flow cytometry. Results showed that FEV%, FVC% and FEV1/FVC were significantly reduced and Bosken scores were remarkably increased in COPD patients compared to non-COPD patients (p < 0.05). CD80 and FoxP3 levels were lower, and CCR6 and IL-17A levels were higher obviously in COPD compared to non-COPD patients (p < 0.05). COPD patients illustrated reduced mDCs levels and enhanced imDCs levels. COPD patients exhibited remarkably higher Th17 levels compared to no-smoking patients (p < 0.05). COPD patients illustrated obviously lower Treg levels and significantly higher Th17/Treg ratio compared to non-smoking patients (p < 0.05). Th17% (Th17/Treg) negatively and Treg% was positively correlated with FEV1%, FEVC%, FEV1/FEVC (p < 0.05). In conclusion, dendritic cells and Th17/Treg ratio play critical roles for pathogenic process of chronic obstructive pulmonary disease.


Assuntos
Células Dendríticas/imunologia , Doença Pulmonar Obstrutiva Crônica/imunologia , Linfócitos T Reguladores/imunologia , Células Th17/imunologia , Antígeno B7-1/metabolismo , Feminino , Volume Expiratório Forçado , Fatores de Transcrição Forkhead/metabolismo , Humanos , Interleucina-17/metabolismo , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/sangue , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Receptores CCR6/metabolismo
9.
Mol Med Rep ; 18(4): 3769-3779, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30106102

RESUMO

Lung cancer is one of the most prevalent malignancies worldwide; it has been ranked the most lethal type of cancer. Non­small cell lung carcinoma (NSCLC) comprises >80% of all types of lung cancer. Although certain achievements have been made in the treatment of NSCLC, including the targeted gene drug epidermal growth factor receptor­tyrosine kinase inhibitor (EGFR­TKI), the five­year survival rate of patients has not significantly increased. A previous study demonstrated that B7­H5, a novel co­stimulatory molecule in the B7 molecule family, was negatively correlated with EGFR in pancreatic cancer. Thus, in the present study, we aimed to investigate whether EGFR participates in immune evasion, probably through regulation of B7­H5 expression. NCI­H1299 NSCLCL cells were divided into control, mock, small interfering­EGFR and EGFR­TKI groups. The cell viability and apoptosis rate were analysed by a Cell Counting Kit­8 assay and flow cytometry. The transforming growth factor (TGF)­ß and interleukin (IL)­10 content was measured using an ELISA. The expression levels of EGFR, B7­H5, Survivin, apoptosis regulator Bax, apoptosis regulator Bcl­2 (Bcl­2), TGF­ß, vascular endothelial growth factor (VEGF), IL­10 and cyclooxygenase (COX)­2 were assessed via quantitative PCR and western blotting. The activation of the tyrosine­protein kinase JAK2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signalling pathway was detected using western blotting. The results demonstrated a notable negative correlation between EGFR and B7­H5 expression levels in cancer tissues and cell lines. Inhibition of EGFR expression via gene silencing and EGFR inhibition markedly decreased cell viability and increased the apoptosis of NCI­H1299 cells, by upregulating survivin and Bcl­2 expression. The protein expression levels of TGF­ß, VEGF, IL­10 and COX­2 were additionally decreased, with weak activation of the JAK2/STAT3 signalling pathway. EGFR may be involved in immune evasion, possibly through regulation of B7­H5 expression in NSCLC.


Assuntos
Antígenos B7/imunologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Receptores ErbB/imunologia , Neoplasias Pulmonares/imunologia , Evasão Tumoral , Apoptose , Antígenos B7/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética
10.
ACS Appl Mater Interfaces ; 10(26): 22757-22766, 2018 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-29894150

RESUMO

In this work, a bistable polymer framework liquid crystal (PFLC) thin film by thermal curing of epoxy monomers with two different thiols, a traditional flexible-structure thiol and a novel original rigid-structure thiol, has been successfully fabricated, combining a novel mixed morphology of polymer matrix and cholesteric liquid crystals with negative dielectric anisotropy. The polymer framework morphology has been formed by curing two types of epoxy monomers with two types of thiols, and the liquid crystals tend to be focal conic textures with large size domains at the initial state in the PFLC film so that it has a moderate light transmissivity at this state between the transparent state and the opaque state. Thus, the devices based on PFLC films can be switched reversibly between the transparent state and the opaque state by alternative electric field. In addition, the states can be sustained after the electric field is removed. The bistable memory effect comes from the anchoring effects of the polymer frameworks with a novel morphology in the microdomains of the PFLCs. Therefore, the optimized bistable PFLC film keeps its initial state without external electric field and any other energy consumption for a long time after altering the state by applying an instant electric field. The special polymer frameworks in the bistable PFLC films endow the films with excellent electro-optical properties and mechanical properties. The devices are energy-efficient and cost-saving and have great potential applications in energy-efficient reflective displays, electronic papers, writing tablets, and smart windows.

11.
Adv Sci (Weinh) ; 5(2): 1700613, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29619309

RESUMO

Dynamic controllability of self-organized helical superstructures in spatial dimensions is a key step to promote bottom-up artificial nanoarchitectures and functional devices for diverse applications in a variety of areas. Here, a light-driven chiral overcrowded alkene molecular motor with rod-like substituent is designed and synthesized, and its thermal isomerization reaction exhibits an increasing structural entropy effect on chemical kinetic analysis in anisotropic achiral liquid crystal host than that in isotropic organic liquid. Interestingly, the stimuli-directed angular orientation motion of helical axes in the self-organized helical superstructures doped with the chiral motors enables the dynamic reconfiguration between the planar (thermostationary) and focal conic (photostationary) states. The reversible micromorphology deformation processes are compatible with the free energy fluctuation of self-organized helical superstructures and the chemical kinetics of chiral motors under different conditions. Furthermore, stimuli-directed reversible nonmechanical beam steering is achieved in dynamic hidden periodic photopatterns with reconfigurable attributes prerecorded with a corresponding photomask and photoinduced polymerization.

12.
Polymers (Basel) ; 10(7)2018 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-30960718

RESUMO

Organosilicon polymer materials play an important role in certain applications due to characteristics of much lower glass transition temperatures (Tg), viscosities, surface energy, as well as good mechanical, thermal stabilities, and insulation performance stemming from the higher bond energy and the larger bond angles of the adjacent silicon-oxygen bond. This critical review highlights developments in the synthesis, structure, and phase transition behaviors of polysiloxane-based side chain liquid crystal polymers (PSCLCPs) of linear and cyclic polysiloxanes containing homopolymers and copolymers. Detailed synthetic strategies are elaborated, and the relationship between molecular structures and liquid crystalline phase transition behaviors is systematically discussed, providing theoretical guidance on the molecular design of the materials.

13.
Polymers (Basel) ; 10(4)2018 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-30966488

RESUMO

In the harsh application environment, improving the mechanical properties of liquid crystal materials is a fundamental and important problem in the design of anti-counterfeit materials. In this paper, by a stepwise polymerization of first, photo-polymerization and subsequently thermal-polymerization, a coexistent polymer dispersed network was first constructed in cholesteric liquid crystal materials containing a photo-polymerizable system of urethane acrylate and a thermo-polymerizable system of isocyanate. Results revealed that the coexistent polymer dispersed network exhibited largely enhanced mechanical performance, and the networks obtained by different methods had different contributions to the enhancement of the peel strength and toughness of the composite films. Then an angular photochromic anti-fake label based on a coexistent polymer dispersed network with enhanced mechanical and apparent angular discoloration characteristics, suitable for practical applications, was successfully achieved.

14.
Chem Commun (Camb) ; 54(4): 397-400, 2018 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-29250637

RESUMO

Novel mesogenic [60]fullerenes have been synthesized and doped into cholesteric liquid crystals (CLCs) to achieve a dual-mechanism laser protection system that is effective for both pulsed and broadband cw lasers, simultaneously. It was found that this system integrated a good OPL response, broadband protection range, and high practicability with great potentials in flexible and even wearable protection devices.

15.
ACS Appl Mater Interfaces ; 9(46): 40810-40819, 2017 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29094919

RESUMO

Smart windows with controllable visible and near-infrared light transmittance can significantly improve the building's energy efficiency and inhabitant comfort. However, most of the current smart window technology cannot achieve the target of ideal solar control. Herein, we present a novel all-solution-processed hybrid micronano composite smart material that have four optical states to separately modulate the visible and NIR light transmittance through voltage and temperature, respectively. This dual-band optical modulation was achieved by constructing a phase-separated polymer framework, which contains the microsized liquid crystals domains with a negative dielectric constant and tungsten-doped vanadium dioxide (W-VO2) nanocrystals (NCs). The film with 2.5 wt % W-VO2 NCs exhibits transparency at normal condition, and the passage of visible light can be reversibly and actively regulated between 60.8% and 1.3% by external applied voltage. Also, the transmittance of NIR light can be reversibly and passively modulated between 59.4% and 41.2% by temperature. Besides, the film also features easy all-solution processability, fast electro-optical (E-O) response time, high mechanical strength, and long-term stability. The as-prepared film provides new opportunities for next-generation smart window technology, and the proposed strategy is conductive to engineering novel hybrid inorganic-organic functional matters.

16.
ACS Appl Mater Interfaces ; 9(27): 23246-23254, 2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28613819

RESUMO

A series of sticky superhydrophobicity surfaces with high water contact angle and high water adhesive force is facilely prepared via an all-solution-processed method based on polymerization-induced phase separation between liquid crystals (LCs) and epoxy resin, which produces layers of epoxy microspheres (EMSs) with nanofolds on the surface of a substrate. The morphologies and size distributions of EMSs are confirmed by scanning electron microscopy. Results reveal that the obtained EMS coated-surface exhibits high apparent contact angle of 152.0° and high water adhesive force up to 117.6 µN. By varying the composition of the sample or preparing conditions, the sizes of the produced EMSs can be artificially regulated and, thus, control the wetting properties and water adhesive behaviors. Also, the sticky superhydrophobic surface exhibits excellent chemical stability, as well as long-term durability. Water droplet transportation experiments further prove that the as-made surface can be effectively used as a mechanical hand for water transportation applications. Based on this, it is believed that the simple method proposed in this paper will pave a new way for producing a sticky superhydrophobic surface and obtain a wide range of use.

17.
Small ; 13(22)2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28437027

RESUMO

Controllable assembly of molecular motors on solid surfaces is a fundamental issue for providing them to perform physical tasks. However, it can hardly be achieved by most previous methods due to their inherent limitations. Here, a general strategy is designed for the reprogrammable assembly of molecular motors on solid surfaces based on dynamic bonds. In this method, molecular motors with disulfide bonds can be remotely, reversibly, and precisely attached to solid surfaces with disulfide bonds, regardless of their chemical composition and microstructure. More importantly, it not only allows encoding geometric information referring to a pattern of molecular motors, but also enables erasing and re-encoding of geometric information via hemolytic photocleavage and recombination of disulfide bonds. Thus, solid surfaces can be regarded as "computer hardware", where molecular motors can be reformatted and reprogramed as geometric information.

18.
Molecules ; 22(2)2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28241442

RESUMO

In this study, a polymer dispersed cholesteric liquid crystal (PDChLC) film obtained via a one-step fabrication technique based on photopolymerization of a thiol-acrylate reaction system was prepared and characterized for the first time. The effects of the chiral dopant, the influence of thiol monomer functionality and content on the morphology and subsequent performance of the PDChLC films were systematically investigated. It was demonstrated that the addition of a small amount of chiral dopant slightly increased the driving voltage, but decreased the off-state transmittance significantly. Furthermore, scanning electron micrographs (SEM) shown that the liquid crystal (LC) droplet size decreased at first and then increased with the increasing amount of thiol monomer functionality, while increasing the thiol content increased the LC droplet size. Correspondingly, the electro-optical switching behavior was directly dependent on LC droplet size. By tuning the raw material composition, PDChLC film with optimized electro-optical performance was prepared.


Assuntos
Acrilatos/química , Cristais Líquidos/química , Polímeros/química , Compostos de Sulfidrila/química , Eletricidade , Luz , Microscopia Eletrônica de Varredura , Estrutura Molecular , Fenômenos Ópticos
19.
Sci Rep ; 7: 42955, 2017 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-28230153

RESUMO

High-performance and cost-effective laser protection system is of crucial importance for the rapid advance of lasers in military and civilian fields leading to severe damages of human eyes and sensitive optical devices. However, it is crucially hindered by the angle-dependent protective effect and the complex preparation process. Here we demonstrate that angle-independence, good processibility, wavelength tunability, high optical density and good visibility can be effectuated simultaneously, by embedding dichroic anthraquinone dyes in a cholesteric liquid crystal matrix. More significantly, unconventional two-dimensional parabolic protection behavior is reported for the first time that in stark contrast to the existing protection systems, the overall parabolic protection behavior enables protective effect to increase with incident angles, hence providing omnibearing high-performance protection. The protective effect is controllable by dye concentration, LC cell thickness and CLC reflection efficiency, and the system can be made flexible enabling applications in flexible and even wearable protection devices. This research creates a promising avenue for the high-performance and cost-effective laser protection, and may foster the development of optical applications such as solar concentrators, car explosion-proof membrane, smart windows and polarizers.

20.
ACS Appl Mater Interfaces ; 9(3): 2942-2947, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28001028

RESUMO

Polymer-dispersed liquid crystal (PDLC) and polymer-stabilized liquid crystal (PSLC) systems are the two primary distinct systems in the field of liquid crystal (LC) technology, and they are differentiated by their unique microstructures. Here, we present a novel coexistent system of polymer-dispersed and polymer-stabilized liquid crystals (PD&SLCs), which forms a homeotropically aligned polymer network (HAPN) within the LC droplets after a microphase separation between the LC and polymer matrix and combines the advantages of both the PDLC and PSLC systems. Then, we prepare a novel thermally light-transmittance-controllable (TLTC) film from the PD&SLC system, where the transmittance can be reversibly changed through thermal control from a transparent to a light-scattering state. The film also combines the advantageous features of flexibility and a potential for large-scale manufacturing, and it shows significant promise in future applications from smart windows to temperature sensors.

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