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1.
Adv Mater ; : e2104761, 2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34632640

RESUMO

Elastomeric dielectrics are crucial for reliably governing the carrier densities in semiconducting channels during deformation in soft/stretchable field-effect transistors (FETs). Uncontrolled stacking of polymeric chains renders elastomeric dielectrics poorly insulated at nanoscale thicknesses, thereby thick films are usually required, leading to high voltage or power consumption for on/off operations of FETs. Here, layer-by-layer assembly is exploited to build 15-nm-thick elastomeric nanodielectrics through alternative adsorption of oppositely charged polyurethanes (PUs) for soft and hysteresis-free FETs. After mild thermal annealing to heal pinholes, such PU multilayers offer high areal capacitances of 237 nF cm-2 and low leakage current densities of 3.2 × 10-8 A cm-2 at 2 V. Owing to the intrinsic ductility of the elastomeric PUs, the nanofilms possess excellent dielectric properties at a strain of 5% or a bending radius of 1.5 mm, while the wrinkled counterparts show mechanical stability with negligible changes of leakage currents after repeated stretching to a strain of 50%. Besides, these nanodielectrics are immune to high humidity and conserve their properties when immersed into water, despite their assembly occurs aqueously. Furthermore, the PU dielectrics are implemented in carbon nanotube FETs, demonstrating low-voltage operations (< 1.5 V) and negligible hysteresis without any encapsulations.

2.
Sensors (Basel) ; 21(18)2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34577250

RESUMO

Due to the complex marine environment, side-scan sonar signals are unstable, resulting in random non-rigid distortion in side-scan sonar strip images. To reduce the influence of resolution difference of common areas on strip image mosaicking, we proposed a mosaic method for side-scan sonar strip images based on curvelet transform and resolution constraints. First, image registration was carried out to eliminate dislocation and distortion of the strip images. Then, the resolution vector of the common area in two strip images were calculated, and a resolution model was created. Curvelet transform was then performed for the images, the resolution fusion rules were used for Coarse layer coefficients, and the maximum coefficient integration was applied to the Detail layer and Fine layer to calculate the fusion coefficients. Last, inverse Curvelet transform was carried out on the fusion coefficients to obtain images in the fusion area. The fusion images in multiple areas were then combined in the registered images to obtain the final image. The experiment results showed that the proposed method had better mosaicking performance than some conventional fusion algorithms.


Assuntos
Algoritmos , Software , Cintilografia
3.
Small ; 17(22): e2006043, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33624949

RESUMO

As a burgeoning family of crystalline porous copolymers, covalent organic frameworks (COFs) allow precise atomic insertion of organic components in the topology construction to form periodic networks and ordered nanopores. Their 2D networks bear great similarities to graphene analogs, and therefore are essential additions to the 2D family. Here, the electronic properties of conductive 2D-COFs are reviewed and their bonding strategies and structural characteristics are examined in detail. The controlling approaches toward the morphologies of conductive 2D-COFs are further explored, followed by a discussion of their applications in field-effect transistors, photodetectors, sensors, catalysis, and energy storage. Finally, research challenges and forthcoming developments are projected. The resulting survey reveals that the extended porous 2D organic networks with conductive properties will provide great opportunities and essential innovations in various electronics and energy-related fields.

4.
Br J Pharmacol ; 178(3): 636-653, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33140855

RESUMO

BACKGROUND AND PURPOSE: Psoriasis is a chronic immune-mediated inflammatory skin disease that easily recurs and is difficult to cure. DGT is a novel synthetic heterocyclic diterpenoid, whose structure has not been previously reported. We have investigated the action of DGT against psoriasis, specifically the hyperproliferation of epidermal keratinocytes, angiogenesis and pathogenic inflammatory responses. EXPERIMENTAL APPROACH: We investigated its pharmacokinetics in skin after topical administration. We characterized its pharmacological actions in vitro and in vivo using cell proliferation assay, cell apoptosis assay, diethylstilbestrol-induced mouse vaginal epithelial cell mitosis model, tube formation assay, cell migration assay, chick embryonic chorioallantoic membrane (CAM) assay, histological, flow cytometric analysis and imiquimod (IMQ)-induced psoriasis-like model. KEY RESULTS: DGT was found to be mainly distributed in the epidermis and dermis, which indicated that DGT was suitable as a topical treatment. DGT inhibited cell proliferation and induced apoptotic cell death of keratinocytes in vitro and in vivo. Moreover, DGT inhibited endothelial cell proliferation, tube formation and migration of in vitro angiogenesis, as well as in vivo CAM angiogenesis. In an IMQ-induced psoriasis-like skin inflammation murine model, topical application of DGT ameliorated keratinocyte proliferation and inflammatory response, especially in IL-17-related psoriasiform dermatitis. Furthermore, our results demonstrated that DGT prevented these pathological processes of psoriasis through suppression of STAT3 phosphorylation. CONCLUSION AND IMPLICATIONS: DGT has great potential as a novel therapeutic agent for the treatment of psoriatic skin disease.


Assuntos
Diterpenos , Psoríase , Animais , Modelos Animais de Doenças , Diterpenos/farmacologia , Feminino , Imiquimode/metabolismo , Imiquimode/toxicidade , Queratinócitos , Camundongos , Camundongos Endogâmicos BALB C , Fosforilação , Psoríase/induzido quimicamente , Psoríase/tratamento farmacológico , Psoríase/metabolismo , Pele/metabolismo
5.
Fitoterapia ; 142: 104489, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32004654

RESUMO

Influenza virus is one of the most widespread infectious diseases in the world. It poses a serious public health threat to humans. With the emergence of drug-resistant virus strains, antiviral drugs are urgently needed to control virus transmission and disease progression. In this study, three main active substances-curcumol, curdione and germacrone-were isolated from the traditional Chinese medicine zedoary. They inhibited the replication of influenza A (H1N1) virus in a dose-dependent manner. After treatment with these compounds, the expression of viral protein and RNA synthesis were inhibited. In vivo, these compounds also reduced H1N1-induced lung damage and the load of virus in serum as well as whole blood cells. In a proteomic analysis, after treatment with germacrone, the expression of antiviral protein and the amount of intracellular virus were significantly reduced, further proving that germacrone can inhibit viral replication. Our experiments have shown that curcumol, curdione and germacrone can inhibit the replication of H1N1 virus; in particular, germacrone shows potential both in vitro and in vivo as a therapeutic drug.


Assuntos
Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Sesquiterpenos de Germacrano/farmacologia , Sesquiterpenos/farmacologia , Células A549 , Animais , Proliferação de Células , Medicamentos de Ervas Chinesas , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Estrutura Molecular , Óleos/química , Infecções por Orthomyxoviridae/tratamento farmacológico , Infecções por Orthomyxoviridae/virologia , Sesquiterpenos/química , Sesquiterpenos de Germacrano/química , Organismos Livres de Patógenos Específicos
6.
Small ; 15(51): e1906086, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31762172

RESUMO

Controlled growth of metal-organic frameworks (MOFs) nanocrystals on requisite surfaces is highly desired for myriad applications related to catalysis, energy, and electronics. Here, this challenge is addressed by overlaying arbitrary surfaces with a thermally evaporated metal layer to enable the well-aligned growth of ultralong quasi-2D MOF nanoarrays comprising cobalt ions and thiophenedicarboxylate acids. This interfacial engineering approach allows preferred chelation of carboxyl groups in the ligands with the metal interlayers, thereby making possible the fabrication and patterning of MOF nanoarrays on substrates of any materials or morphologies. The MOF nanoarrays grown on porous metal scaffolds demonstrate high electrocatalytic capability for water oxidation, exhibiting a small overpotential of 270 mV at 10 mA cm-2 , or 317 mV at 50 mA cm-2 as well as negligible decay of performance within 30 h. The enhanced performance stems from the improved electron and ion transport in the hierarchical porous nanoarrays consisting of in situ formed oxyhydroxide nanosheets in the electrochemical processes. This approach for mediating the growth of MOF nanoarrays can serve as a promising platform for diverse applications.

7.
Int J Biol Sci ; 12(7): 872-83, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27313500

RESUMO

Dengue virus (DENV) causes the most prevalent arthropod-borne viral disease of humans worldwide. Glycosphingolipids (GSLs) are involved in virus infection by regulating various steps of viral-host interaction. However, the distinct role of GSLs during DENV infection remains unclear. In this study, we used mouse melanoma B16 cells and their GSL-deficient mutant counterpart GM95 cells to study the influence of GSLs on DENV infection. Surprisingly, GM95 cells were highly resistant to DENV infection compared with B16 cells. Pretreatment of B16 cells with synthetase inhibitor of GM3, the most abundant GSLs in B16 cells, or silencing GM3 synthetase T3GAL5, significantly inhibited DENV infection. DENV attachment and endocytosis were not impaired in GM95 cells, but DENV genome replication was obviously inhibited in GM95 cells compared to B16 cells. Furthermore, GM3 was colocalized with DENV viral replication complex on endoplasmic reticulum (ER) inside the B16 cells. Finally, GM3 synthetase inhibitor significantly reduced the mortality rate of suckling mice that challenged with DENV by impairing the viral replication in mouse brain. Taken together, these data indicated that GM3 was not required for DENV attachment and endocytosis, however, essential for viral genome replication. Targeting GM3 could be a novel strategy to inhibit DENV infection.


Assuntos
Vírus da Dengue/genética , Vírus da Dengue/metabolismo , Genoma Viral/genética , Glicoesfingolipídeos/metabolismo , Replicação Viral/fisiologia , Animais , Linhagem Celular Tumoral , Vírus da Dengue/fisiologia , Flavivirus/genética , Flavivirus/metabolismo , Flavivirus/fisiologia , Glicolipídeos/metabolismo , Camundongos , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/metabolismo , Replicação Viral/genética
8.
Viral Immunol ; 28(8): 448-54, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26196448

RESUMO

Hantaan virus A9 strain (HTNV A9) is an etiologic agent of hemorrhagic fever with renal syndrome in China. The virulence of the pathogenic hantaviruses is determined by their ability to alter key signaling pathways of early interferon (IFN) induction within cells. The potential role of HTNV A9 structural proteins, such as nucleocapsid (N) and envelope glycoproteins (Gn and Gc), in regulating human's innate antiviral immune response has not yet been clarified. In this study, we investigated the effect of HTNV A9 N protein on the regulation of the IFN pathway. We found that A9 N protein can influence the host innate immune response by regulating the activation of IFNß. The A9 N protein stimulates IFN response in low doses, whereas significantly inhibits IFNß production at high doses. Furthermore, A9 N protein constitutively inhibits nuclear factor kappa B activation. A high dose of A9 N protein could inhibit either Poly IC-induced IFNß or vesicular stomatitis virus-induced IFNß and interferon-stimulated gene production. Our results indicate that HTNV A9 N protein helps virus establish successful infection by downregulating the IFN response and shed new light to the understanding of the interaction between the host innate immunity and virus during Hantaan virus infection.


Assuntos
Vírus Hantaan/imunologia , Interações Hospedeiro-Patógeno , Evasão da Resposta Imune , Imunidade Inata , Interferon beta/metabolismo , Proteínas do Nucleocapsídeo/imunologia , Transdução de Sinais , Animais , China , Chlorocebus aethiops , Regulação para Baixo , Humanos , Interferon beta/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Células Vero
9.
Parasit Vectors ; 8: 25, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25588982

RESUMO

BACKGROUND: Ticks are distributed worldwide and considered as vectors of many human diseases. Tick defensins, a family of antimicrobial peptides, form the first line of defense against pathogens. FINDINGS: A defensin-like gene, named Ds-defensin, was identified from a cDNA library of the hard tick Dermacentor silvarum collected from northeast China. The full-length cDNA of Ds-defensin was 225 bp, encoding a 74 amino acid peptide. The nucleotide sequence of Ds-defensin shared 98.2% similarity to putative defensin from Dermacentor marginatus. RT-PCR results suggested that Ds-defensin was extensively expressed in tick salivary gland and midgut, with a higher expression level in midgut. Ds-defensin showed broad antimicrobial activity against various Gram-positive and Gram-negative bacteria, as well as the fungus Candida albicans. CONCLUSIONS: We characterized a functional defensin from D. silvarum of China. Ds-defensin showed bactericidal activity against various Gram-positive and Gram-negative bacteria. Ds-defensin can be expected to be introduced to the medical field as a new molecule with antibacterial activity.


Assuntos
Anti-Infecciosos/metabolismo , Candida albicans/efeitos dos fármacos , Defensinas/genética , Dermacentor/genética , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Vetores Aracnídeos/genética , Vetores Aracnídeos/metabolismo , Sequência de Bases , Defensinas/química , Defensinas/metabolismo , Dermacentor/metabolismo , Biblioteca Gênica , Dados de Sequência Molecular , Filogenia , Alinhamento de Sequência , Análise de Sequência de DNA
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