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1.
Nat Mater ; 23(4): 499-505, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38321241

RESUMO

Compressing light into nanocavities substantially enhances light-matter interactions, which has been a major driver for nanostructured materials research. However, extreme confinement generally comes at the cost of absorption and low resonator quality factors. Here we suggest an alternative optical multimodal confinement mechanism, unlocking the potential of hyperbolic phonon polaritons in isotopically pure hexagonal boron nitride. We produce deep-subwavelength cavities and demonstrate several orders of magnitude improvement in confinement, with estimated Purcell factors exceeding 108 and quality factors in the 50-480 range, values approaching the intrinsic quality factor of hexagonal boron nitride polaritons. Intriguingly, the quality factors we obtain exceed the maximum predicted by impedance-mismatch considerations, indicating that confinement is boosted by higher-order modes. We expect that our multimodal approach to nanoscale polariton manipulation will have far-reaching implications for ultrastrong light-matter interactions, mid-infrared nonlinear optics and nanoscale sensors.

2.
Sensors (Basel) ; 23(22)2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-38005665

RESUMO

Digital holographic microscopy (DHM) is a valuable technique for investigating the optical properties of samples through the measurement of intensity and phase of diffracted beams. However, DHMs are constrained by Lagrange invariance, compromising the spatial bandwidth product (SBP) which relates resolution and field of view. Synthetic aperture DHM (SA-DHM) was introduced to overcome this limitation, but it faces significant challenges such as aberrations in synthesizing the optical information corresponding to the steering angle of incident wave. This paper proposes a novel approach utilizing deep neural networks (DNNs) for compensating aberrations in SA-DHM, extending the compensation scope beyond the numerical aperture (NA) of the objective lens. The method involves training a DNN from diffraction patterns and Zernike coefficients through a circular aperture, enabling effective aberration compensation in the illumination beam. This method makes it possible to estimate aberration coefficients from the only part of the diffracted beam cutoff by the circular aperture mask. With the proposed technique, the simulation results present improved resolution and quality of sample images. The integration of deep neural networks with SA-DHM holds promise for advancing microscopy capabilities and overcoming existing limitations.

3.
ACS Nano ; 17(8): 7377-7383, 2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37010352

RESUMO

Photonic crystals and metamaterials are two overarching paradigms for manipulating light. By combining these approaches, hypercrystals can be created, which are hyperbolic dispersion metamaterials that undergo periodic modulation and mix photonic-crystal-like aspects with hyperbolic dispersion physics. Despite several attempts, there has been limited experimental realization of hypercrystals due to technical and design constraints. In this work, hypercrystals with nanoscale lattice constants ranging from 25 to 160 nm were created. The Bloch modes of these crystals were then measured directly using scattering near-field microscopy. The dispersion of the Bloch modes was extracted from the frequency dependence of the Bloch modes, revealing a clear switch from positive to negative group velocity. Furthermore, spectral features specific to hypercrystals were observed in the form of sharp density of states peaks, which are a result of intermodal coupling and should not appear in ordinary polaritonic crystals with an equivalent geometry. These findings are in agreement with theoretical predictions that even simple lattices can exhibit a rich hypercrystal bandstructure. This work is of both fundamental and practical interest, providing insight into nanoscale light-matter interactions and the potential to manipulate the optical density of states.

4.
Int J Nanomedicine ; 18: 1561-1575, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37007987

RESUMO

Introduction: The ongoing SARS-CoV-2 pandemic has affected public health, the economy, and society. This study reported a nanotechnology-based strategy to enhance the antiviral efficacy of the antiviral agent remdesivir (RDS). Results: We developed a nanosized spherical RDS-NLC in which the RDS was encapsulated in an amorphous form. The RDS-NLC significantly potentiated the antiviral efficacy of RDS against SARS-CoV-2 and its variants (alpha, beta, and delta). Our study revealed that NLC technology improved the antiviral effect of RDS against SARS-CoV-2 by enhancing the cellular uptake of RDS and reducing SARS-CoV-2 entry in cells. These improvements resulted in a 211% increase in the bioavailability of RDS. Conclusion: Thus, the application of NLC against SARS-CoV-2 may be a beneficial strategy to improve the antiviral effects of antiviral agents.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Antivirais/farmacologia , Antivirais/uso terapêutico , Tratamento Farmacológico da COVID-19 , Lipídeos
5.
Drug Deliv Transl Res ; 13(5): 1212-1227, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-35794353

RESUMO

Ticagrelor (TCG), an antiplatelet agent, has low solubility and permeability; thus, there are many trials to apply the pharmaceutical technology for the enhancement of TCG solubility and permeability. Herein, we have developed the TCG high-loaded nanostructured lipid carrier (HL-NLC) and solidified the HL-NLC to develop the oral tablet. The HL-NLC was successfully fabricated and optimized with a particle size of 164.5 nm, a PDI of 0.199, an encapsulation efficiency of 98.5%, and a drug loading of 16.4%. For the solidification of HL-NLC (S-HL-NLC), the adsorbent was determined based on the physical properties of the S-HL-NLC, such as bulk density, tap density, angle of repose, Hausner ratio, Carr's index, and drug content. Florite R was chosen because of its excellent adsorption capacity, excellent physical properties, and solubility of the powder after manufacturing. Using an S-HL-NLC, the S-HL-NLC tablet with HPMC 4 K was prepared, which is showed a released extent of more than 90% at 24 h. Thus, we have developed the sustained release tablet containing the TCG-loaded HL-NLC. Moreover, the formulations have exhibited no cytotoxicity against Caco-2 cells and improved the cellular uptake of TCG. In pharmacokinetic study, compared with raw TCG, the bioavailability of HL-NLC and S-HL-NLC was increased by 293% and 323%, respectively. In conclusion, we successfully developed the TCG high-loaded NLC tablet, that exhibited a sustained release profile and enhanced oral bioavailability.


Assuntos
Sistemas de Liberação de Medicamentos , Nanoestruturas , Humanos , Portadores de Fármacos/farmacocinética , Ticagrelor , Preparações de Ação Retardada , Células CACO-2 , Comprimidos , Lipídeos , Tamanho da Partícula
6.
J Med Virol ; 95(1): e28362, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36453088

RESUMO

We probed the lifecycle of Epstein-Barr virus (EBV) on a cell-by-cell basis using single cell RNA sequencing (scRNA-seq) data from nine publicly available lymphoblastoid cell lines (LCLs). While the majority of LCLs comprised cells containing EBV in the latent phase, two other clusters of cells were clearly evident and were distinguished by distinct expression of host and viral genes. Notably, both were high expressors of EBV LMP1/BNLF2 and BZLF1 compared to another cluster that expressed neither gene. The two novel clusters differed from each other in their expression of EBV lytic genes, including glycoprotein gene GP350. The first cluster, comprising GP350- LMP1hi cells, expressed high levels of HIF1A and was transcriptionally regulated by HIF1-α. Treatment of LCLs with Pevonedistat, a drug that enhances HIF1-α signaling, markedly induced this cluster. The second cluster, containing GP350+ LMP1hi cells, expressed EBV lytic genes. Host genes that are controlled by super-enhancers (SEs), such as transcription factors MYC and IRF4, had the lowest expression in this cluster. Functionally, the expression of genes regulated by MYC and IRF4 in GP350+ LMP1hi cells were lower compared to other cells. Indeed, induction of EBV lytic reactivation in EBV+ AKATA reduced the expression of these SE-regulated genes. Furthermore, CRISPR-mediated perturbation of the MYC or IRF4 SEs in LCLs induced the lytic EBV gene expression, suggesting that host SEs and/or SE target genes are required for maintenance of EBV latency. Collectively, our study revealed EBV-associated heterogeneity among LCLs that may have functional consequence on host and viral biology.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 4 , Análise de Célula Única , Humanos , Linhagem Celular , Análise de Dados , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/genética , Herpesvirus Humano 4/metabolismo , Latência Viral , Linfócitos/metabolismo , Linfócitos/virologia
7.
Pest Manag Sci ; 79(2): 678-687, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36229424

RESUMO

BACKGROUND: Exposure of agricultural workers in rice paddies to the insecticide chlorantraniliprole and its subsequent potential health risks were investigated during two scenarios (mixing/loading and hand-held spraying). The exposure factors, such as the outer dosimeter, inner dosimeter, gauze, and nitrile gloves, were calculated using whole-body dosimetry to measure dermal exposure. The inhalation exposure was determined using a fiberglass filter which is set with an Institute of Occupational Medicine (IOM) sampler. A recovery test was performed to evaluate the accuracy of the analytical method. RESULTS: The exposure amounts of various matrices were calculated from extraction volume and concentration of the target compound. The dermal exposure to chlorantraniliprole was 0.6 mg [0.001% of the total active ingredient (a.i.)] for mixing and loading, and 28.6 mg (0.066% of the total a.i.) for application. The inhalation exposure to chlorantraniliprole was 7.2 µg (1.3%, 1.2 × 10-5 % of the total applied a.i.) for mixing and loading, and 1.9 µg (0.006%, 4.4 × 10-6 % of the total applied a.i.) for application. The most exposed part of the body was the hand (90.4%) during mixing and loading, whereas the primary sites during application were the thighs (32.8%) and shins (22.6%). For mixing and loading, the amount of actual dermal exposure was 5.5 µg day-1 and that of actual inhalation exposure was 21.9 µg day-1 . By contrast, in the application, the amounts of actual dermal and actual inhalation exposures were 34 178.7 and 5.9 µg day-1 , respectively. CONCLUSIONS: The risk assessment results demonstrated that the risk of chlorantraniliprole exposure in rice paddies was low during application than during mixing and loading. © 2022 Society of Chemical Industry.


Assuntos
Inseticidas , Exposição Ocupacional , Oryza , Humanos , Inseticidas/análise , Exposição Ocupacional/análise , Fazendeiros , Medição de Risco , Exposição por Inalação/análise
8.
Arch Pharm Res ; 45(11): 822-835, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36307644

RESUMO

Zaltoprofen is a nonsteroidal anti-inflammatory drug with poor oral bioavailability. S(+)-zaltoprofen (SZPF)-loaded nanostructured lipid carriers (NLCs) were prepared to enhance oral bioavailability. SZPF-loaded NLCs (NLC-SZPF) were prepared using the hot-melting homogenization method and optimized using the Box-Behnken design. The characterization of optimized NLC-SZPF, in vitro release, cytotoxicity, cellular uptake, ex vivo permeability, and pharmacokinetic parameters were evaluated to confirm the advantages of NLC formulation. NLC-SZPF with a diameter of 105.5 ± 1.2 nm had a high encapsulation efficiency of 99.84 ± 0.01%. NLC-SZPF showed a sustained-release profile, high biocompatibility, and high permeability across the intestinal tract. The relative bioavailability of NLC-SZPF was 431.3% compared with that of SZPF after oral administration to experimental rats. NLC-SZPF was successfully optimized using experimental designs to enhance the oral bioavailability of SZPF. Hence, NLC-SZPF could be a promising approach to overcome the poor oral bioavailability of SZPF.


Assuntos
Portadores de Fármacos , Nanoestruturas , Ratos , Animais , Disponibilidade Biológica , Lipídeos , Solubilidade , Tamanho da Partícula , Administração Oral , Excipientes
9.
J Control Release ; 349: 241-253, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35798094

RESUMO

Although mesoporous silica nanoparticles (MSNs) are widely used as anticancer drug carriers, unmodified MSNs induce off-target effects and at high doses, there are adverse effects of hemolysis because of the interaction with the silanol group on the surface and cells. In this study, we developed doxorubicin (DOX)-loaded MSNs coated with mannose grafted poly (acrylic acid) copolymer (DOX@MSNs-man-g-PAA) to enhance the hemocompatibility and target efficacy to cancer cells. This uniform nanosized DOX@MSNs-man-g-PAA showed sustained and pH-dependent drug release with improved hemocompatibility over the bare MSNs. The uptake of the DOX@MSN-man-g-PAA in breast cancer cells was significantly improved by mannose receptor-mediated endocytosis, which showed significant increasing intracellular ROS and changes in mitochondrial membrane potential. This formulation exhibited superior tumor-suppressing activity in the MDA-MB-231 cells inoculated mice. Overall, the present study suggested the possibility of the copolymer-coated MSNs as drug carriers for cancer therapy.


Assuntos
Antineoplásicos , Nanopartículas , Resinas Acrílicas , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Doxorrubicina , Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Concentração de Íons de Hidrogênio , Manose , Camundongos , Polímeros , Porosidade , Espécies Reativas de Oxigênio , Dióxido de Silício
10.
Sci Rep ; 12(1): 2959, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194078

RESUMO

It is well known that wearing virtual reality (VR) and augmented reality (AR) devices for long periods can cause visual fatigue and motion sickness due to vergence-accommodation conflict (VAC). VAC is considered the main obstacle to the development of advanced three-dimensional VR and AR technology. In this paper, we present a novel AR high-density super-multiview (HDSMV) display technique capable of eliminating VAC in wide range. The designed binocular time-sequential AR HDSMV projection, which delivers 11 views to each eye pupil, is experimentally demonstrated, confirming that VAC is eliminated over a wide-range of viewer's focus distance. It is believed that the proposed time-sequential AR HDSMV method will pave the way for the development of VAC-free AR technology.

11.
Phys Rev Lett ; 128(2): 026801, 2022 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-35089749

RESUMO

We demonstrate that a spin degree of freedom can introduce additional texture to higher order topological insulators (HOTIs), manifesting in novel topological invariants and phase transitions. Spin-polarized mid-gap corner states of various multiplicities are predicted for different HOTI phases, and novel bulk-boundary correspondence principles are defined based on bulk invariants such as total and spin corner charge. Those are shown to be robust to spin-flipping perturbations. Photonic realizations of spin-linked topological phases are demonstrated in engineered systems using pseudospin.

12.
Drug Deliv Transl Res ; 12(2): 415-425, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34494223

RESUMO

Microneedles (MNs), one of the transdermal drug delivery systems, have received extensive interest as an alternative to parenteral or parenteral administrations. For the successful drug delivery of coated MNs, the coated drug or chemical of MNs should be dissolved by skin's interstitial fluid and completely released from the MNs. Thus, the rapid disintegration of the drug from MNs plays a crucial role in ideal drug delivery of MNs. In this study, we developed the rapid disintegration coating formulation to reduce the application time of MN. The rapid disintegration MN was developed using polymers (PVA or HPMC), glycerol, croscarmellose sodium, tween 80, and Brij, as thickener, plasticizer, disintegrating agent, and surfactants, respectively. HPMC MN showed the burst release and rapid disintegration. Moreover, the drug from HPMC MN was successfully delivered into porcine skin within 1 min. In toxicological evaluation, the HPMC MN did not alter the liver and kidney function. Besides, HPMC MN did not induce the acute inflammation and change of skin structure after the application on rat skin. Thus, the coating formulation in this study could be one of the options for the development of safe and rapid disintegration MN.


Assuntos
Sistemas de Liberação de Medicamentos , Agulhas , Administração Cutânea , Animais , Microinjeções , Preparações Farmacêuticas , Ratos , Pele , Suínos
13.
Br J Sociol ; 72(5): 1229-1245, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34350977

RESUMO

How do sexual minorities navigate and negotiate with nationalism? While some scholars consider nationalism as a primarily exclusionary force against sexual minorities, how might we understand sexual minorities' engagement with nationalism? I address these questions by exploring the strategic deployment of sexual and national identities of LGBT movements through the case study of Singapore's annual LGBT-inclusive event, Pink Dot. In response to the authoritarian and heteronormative state's construction of sexual minorities as non-national Others, Pink Dot mobilizes both sexual and national identities in an effort to forge a space of inclusion while ensuring its survival. By portraying itself as a uniquely Singaporean event and espousing national identity and belonging through symbolic and performative practices, Pink Dot leverages national identity to minimize differences from and foreground similarities to the majority. In this way, sexual minorities in Singapore endeavor to embed themselves within the narratives of the nation and claim their legitimate belonging while simultaneously projecting a nation more inclusive of sexual difference. The aspirational inclusion of sexual minorities in the national imagery, however, inevitably elicits the state's backlash that narrowly defines the physical and symbolic boundaries of the political project. This analysis advances our understanding of the interactions between the state and social movements in shaping the relationship among the nation, sexuality, and citizenship.


Assuntos
Cidadania , Minorias Sexuais e de Gênero , Humanos , Comportamento Sexual , Sexualidade , Singapura
14.
Sci Adv ; 7(19)2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33962941

RESUMO

Efficient control of photons is enabled by hybridizing light with matter. The resulting light-matter quasi-particles can be readily programmed by manipulating either their photonic or matter constituents. Here, we hybridized infrared photons with graphene Dirac electrons to form surface plasmon polaritons (SPPs) and uncovered a previously unexplored means to control SPPs in structures with periodically modulated carrier density. In these periodic structures, common SPPs with continuous dispersion are transformed into Bloch polaritons with attendant discrete bands separated by bandgaps. We explored directional Bloch polaritons and steered their propagation by dialing the proper gate voltage. Fourier analysis of the near-field images corroborates that this on-demand nano-optics functionality is rooted in the polaritonic band structure. Our programmable polaritonic platform paves the way for the much-sought benefits of on-the-chip photonic circuits.

15.
Phys Rev Lett ; 126(12): 127402, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33834815

RESUMO

We present a many-body theory of exciton-trion polaritons (ETPs) in doped two-dimensional semiconductor materials. ETPs are robust coherent hybrid excitations involving excitons, trions, and photons. In ETPs, the 2-body exciton states are coupled to the material ground state via exciton-photon interaction, and the 4-body trion states are coupled to the exciton states via Coulomb interaction. The trion states are not directly optically coupled to the material ground state. The energy-momentum dispersion of ETPs exhibit three bands. We calculate the energy band dispersions and the compositions of ETPs at different doping densities using Green's functions. The energy splittings between the polariton bands, as well as the spectral weights of the polariton bands, depend on the strength of the Coulomb coupling between the excitons and the trions, which in turn depends sensitively on the doping density. The doping density dependence of the ETP bands and the charged nature of the trion states could enable novel electrical and optical control of ETPs.

16.
Sensors (Basel) ; 21(1)2020 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-33375748

RESUMO

A vehicular network is composed of an in-vehicle network (IVN) and Internet of Vehicles (IoV). IVN exchanges information among in-vehicle devices. IoV constructs Vehicle-to-X (V2X) networks outside vehicles and exchanges information among V2X elements. These days, in-vehicle devices that require high bandwidth is increased for autonomous driving services. Thus, the spread of data for vehicles is exploding. This kind of data is exchanged through IoV. Even if the Ethernet backbone of IVN carries a lot of data in the vehicle, the explosive increase in data from outside the vehicle can affect the backbone. That is, the transmission efficiency of the IVN backbone will be reduced due to excessive data traffic. In addition, when IVN data traffic is transmitted to IoV without considering IoV network conditions, the transmission efficiency of IoV is also reduced. Therefore, in this paper, we propose an IoV access gateway to controls the incoming data traffic to the IVN backbone and the outgoing data traffic to the IoV in the network environment where IVN and IoV are integrated. Computer simulations are used to evaluate the performance of the proposed system, and the proposed system shows better performance in the accumulated average transmission delay.

17.
Int J Oncol ; 54(6): 2169-2178, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31081047

RESUMO

Forkhead box A1 (FOXA1) functions as a tumor suppressor gene or an oncogene in various types of cancer; however, the distinct function of FOXA1 in colorectal cancer is unclear. The present study aimed to evaluate whether FOXA1 affects the oncogenic behavior of colorectal cancer cells, and to investigate its prognostic value in colorectal cancer. The impact of FOXA1 on tumor cell behavior was investigated using small interfering RNA and the pcDNA6­myc vector in human colorectal cancer cell lines. To investigate the role of FOXA1 in the progression of human colorectal cancer, an immunohistochemical technique was used to localize FOXA1 protein in paraffin­embedded tissue blocks obtained from 403 patients with colorectal cancer. Tumor cell apoptosis and proliferation were evaluated using a terminal deoxynucleotidyl transferase­mediated dUTP nick­end labeling assay and Ki­67 immunohistochemical staining, respectively. FOXA1 knockdown inhibited tumor cell invasion in colorectal cancer cells, and induced apoptosis and cell cycle arrest. FOXA1 knockdown activated cleaved caspase­poly (ADP­ribose) polymerase, upregulated the expression of p53 upregulated modulator of apoptosis, and downregulated BH3 interacting domain death agonist and myeloid cell leukemia­1, leading to the induction of apoptosis. FOXA1 knockdown increased the phosphorylation level of signal transducer and activator of tran-scription­3. By contrast, these results were reversed following the overexpression of FOXA1. The overexpression of FOXA1 was associated with differentiation, lymphovascular invasion, advanced tumor stage, depth of invasion, lymph node metastasis and poor survival rate. The mean Ki­67 labeling index value of FOXA1­positive tumors was significantly higher than that of FOXA1­negative tumors. However, no significant association was observed between the expression of FOXA1 and the mean apoptotic index value. These results indicate that FOXA1 is associated with tumor progression via the modulation of tumor cell survival in human colorectal cancer.


Assuntos
Neoplasias Colorretais/patologia , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Regulação para Cima , Células CACO-2 , Diferenciação Celular , Linhagem Celular Tumoral , Movimento Celular , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Células HCT116 , Células HT29 , Humanos , Metástase Linfática , Masculino , Estadiamento de Neoplasias , Prognóstico , Transdução de Sinais , Análise de Sobrevida
18.
Int J Oncol ; 54(5): 1875-1883, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30864676

RESUMO

Reversine, a 2,6­diamino­substituted purine analogue, has been reported to be effective in tumor suppression via induction of cell growth arrest and apoptosis of cancer cells. However, it remains unclear whether reversine exerts anticancer effects on human colorectal cancer cells. In the present study, in vitro experiments were conducted to investigate the anticancer properties of reversine in human colorectal cancer cells. The effect of reversine on human colorectal cancer cell lines, SW480 and HCT­116, was examined using a WST­1 cell viability assay, fluorescence microscopy, flow cytometry, DNA fragmentation, small interfering RNA (siRNA) and western blotting. Reversine treatment demonstrated cytotoxic activity in human colorectal cancer cells. It also induced apoptosis by activating poly(ADP­ribose) polymerase, caspase­3, ­7 and ­8, and increasing the levels of the pro­apoptotic protein second mitochondria­derived activator of caspase/direct inhibitor of apoptosis­binding protein with low pI. The pan­caspase inhibitor Z­VAD­FMK attenuated these reversine­induced apoptotic effects on human colorectal cancer cells. Additionally, reversine treatment induced cell cycle arrest in the subG1 and G2/M phases via increase in levels of p21, p27 and p57, and decrease in cyclin D1 levels. The expression of Fas and death receptor 5 (DR5) signaling proteins in SW480 and HCT116 cells was upregulated by reversine treatment. Reversine­induced apoptosis and cell cycle arrest were suppressed by inhibition of Fas and DR5 expression via siRNA. In conclusion, Reversine treatment suppressed tumor progression by the inhibition of cell proliferation, induction of cell cycle arrest and induction of apoptosis via upregulation of the Fas and DR5 signaling pathways in human colorectal cancer cells. The present study indicated that reversine may be used as a novel anticancer agent in human colorectal cancer.


Assuntos
Neoplasias Colorretais/metabolismo , Morfolinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Purinas/farmacologia , Receptores do Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Receptor fas/metabolismo , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HCT116 , Humanos , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima
19.
Phys Rev Lett ; 121(8): 086807, 2018 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-30192584

RESUMO

A valley plasmonic crystal for graphene surface plasmons is proposed. We demonstrate that a designer metagate, placed within a few nanometers of graphene, can be used to impose a periodic Fermi energy landscape on graphene. For specific metagate geometries and bias voltages, the combined metagate-graphene structure is shown to produce complete propagation band gaps for the plasmons, and to impart them with nontrivial valley-linked topological properties. Sharply curved domain walls between differently patterned metagates are shown to guide highly localized plasmons without any reflections owing to suppressed intervalley scattering. Our approach paves the way for nonmagnetic and dynamically reconfigurable topological nanophotonic devices.

20.
ACS Nano ; 8(6): 5988-6003, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24861723

RESUMO

We synthesized a series of acceptor-donor-acceptor-type small molecules (SIDPP-EE, SIDPP-EO, SIDPP-OE, and SIDPP-OO) consisting of a dithienosilole (SI) electron-donating moiety and two diketopyrrolopyrrole (DPP) electron-withdrawing moieties each bearing linear n-octyl (O) and/or branched 2-ethylhexyl (E) alkyl side chains. X-ray diffraction patterns revealed that SIDPP-EE and SIDPP-EO films were highly crystalline with pronounced edge-on orientation, whereas SIDPP-OE and SIDPP-OO films were less crystalline with a radial distribution of molecular orientations. Near-edge X-ray absorption fine structure spectroscopy disclosed an edge-on orientation with a molecular backbone tilt angle of ∼22° for both SIDPP-EE and SIDPP-EO. Our analysis of the molecular packing and orientation indicated that the shorter 2-ethylhexyl groups on the SI core promote tight π-π stacking of the molecular backbone, whereas n-octyl groups on the SI core hinder close π-π stacking to some degree. Conversely, the longer linear n-octyl groups on the DPP arms facilitate close intermolecular packing via octyl-octyl interdigitation. Quantum mechanics/molecular mechanics molecular dynamics simulations determined the optimal three-dimensional positions of the flexible alkyl side chains of the SI and DPP units, which elucidates the structural cause of the molecular packing and orientation explicitly. The alkyl-chain-dependent molecular stacking significantly affected the electrical properties of the molecular films. The edge-on oriented molecules showed high hole mobilities in organic field-effect transistors, while the radially oriented molecules exhibited high photovoltaic properties in organic photovoltaic cells. These results demonstrate that appropriate positioning of alkyl side chains can modulate crystallinity and molecular orientation in SIDPP films, which ultimately have a profound impact on carrier transport and photovoltaic performance.

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