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1.
Bioorg Med Chem Lett ; 41: 127976, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-33766765

RESUMO

A series of 1,4-naphthoquinone derivatives of lawsone (1), 6-hydroxy-1,4-naphthoquinone (2), and juglone (3) were synthesized by alkylation, acylation, and sulfonylation reactions. The yields of lawsone derivatives 1a-1k (type A), 6-hydroxy-1,4-naphthoquinone derivatives 2a-2j (type B), and juglone derivatives 3a-3h (type C) were 52-99%, 53-96%, and 28-95%, respectively. All compounds were tested in vitro for the cytotoxicity against human oral epidermoid carcinoma (KB) and cervix epithelioid carcinoma (HeLa) cells and their structure-activity relationship was studied. Compound 3c was found to be most potent in KB cell line (IC50 = 1.39 µM). Some compounds were evaluated for DNA topoisomerase I inhibition. Compounds 2c, 3, 3a, and 3d showed topoisomerase inhibition activity with IC50 values of 8.3-91 µM. Standard redox potentials (E°) of all naphthoquinones in phosphate buffer at pH 7.2 were examined by means of cyclic voltammetry. A definite correlation has been found between the redox potentials and inhibitory effects of type A compounds.

2.
Orthop Surg ; 13(3): 719-733, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33738959

RESUMO

OBJECTIVES: To investigate the proportion of insulin-dependent diabetes mellitus (IDDM) patients among diabetic patients undergoing total joint arthroplasty (TJA) and whether insulin dependence is associated with postoperative complications. METHODS: A systematic literature search was performed in EMBASE, PubMed, Ovid, Medline, the Cochrane Library, Web of Science, the China Science and Technology Journal Database, and China National Knowledge Infrastructure from the inception dates to 10 September 2019. Observational studies reporting adverse events with IDDM following TJA were included. Primary outcomes were cardiovascular complications, pulmonary complications, kidney complications, wound complications, infection, and other complications within 30 days of surgery. Secondary outcomes were the proportion of IDDM patients among diabetic patients undergoing TJA and its time trend. RESULTS: A total of 19 studies involving 85,689 participants were included. Among patients undergoing TJA, 26% of diabetic patients had IDDM. Compared with non-insulin-dependent diabetes (NIDDM), the incidences of cardiac arrest (risk ratio [RR], 2.346; 95% confidence interval [CI], 1.553 to 3.546), renal failure (relative risk [RR], 2.758; 95% CI, 1.830 to 4.156), deep incisional surgical site infection (RR, 1.968; 95% CI, 1.107 to 3.533), wound dehiscence (RR, 2.209; 95% CI, 1.830 to 4.156), and death (RR, 2.292; 95% CI, 1.568 to 3.349) were all significantly increased in IDDM. A significant time trend was witnessed for the prevalence of IDDM (P = 0.014). There was no statistical significance for organ/space surgical site infection, thrombotic events (deep venous thrombosis/ pulmonary embolism), and revision rates. CONCLUSION: Insulin-dependent diabetes is an independent high-risk factor for increased adverse outcomes relative to NIDDM, suggesting that hierarchical and optimal blood glucose management may contribute to reducing the adverse complications after surgery for these patients. In addition, because the risk of sepsis, deep wound infection, organ/space surgical site infection, urinary tract infection, renal insufficiency, and renal failure significantly increase after TJA in IDDM patients, more active postoperative antimicrobial prophylaxis may be needed on the premise of protecting renal function.

3.
ACS Nano ; 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33651590

RESUMO

Platinum diselenide (PtSe2) is a group-10 two-dimensional (2D) transition metal dichalcogenide that exhibits the most prominent atomic-layer-dependent electronic behavior of "semiconductor-to-semimetal" transition when going from monolayer to bulk form. This work demonstrates an efficient photoelectrochemical (PEC) conversion for direct solar-to-hydrogen (H2) production based on 2D layered PtSe2/Si heterojunction photocathodes. By systematically controlling the number of atomic layers of wafer-scale 2D PtSe2 films through chemical vapor deposition (CVD), the interfacial band alignments at the 2D layered PtSe2/Si heterojunctions can be appropriately engineered. The 2D PtSe2/p-Si heterojunction photocathode consisting of a PtSe2 thin film with a thickness of 2.2 nm (or 3 atomic layers) exhibits the optimized band alignment and delivers the best PEC performance for hydrogen production with a photocurrent density of -32.4 mA cm-2 at 0 V and an onset potential of 1 mA cm-2 at 0.29 V versus a reversible hydrogen electrode (RHE) after post-treatment. The wafer-scale atomic-layer controlled band engineering of 2D PtSe2 thin-film catalysts integrated with the Si light absorber provides an effective way in the renewable energy application for direct solar-to-hydrogen production.

4.
Pestic Biochem Physiol ; 171: 104720, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33357542

RESUMO

Chilo suppressalis Walker (Lepidoptera: Crambidae) is a widely destructive pest occurring in rice, particularly in the rice-growing regions of Asia. In recent years, C. suppressalis has developed resistance to several insecticides because of the extensive use of insecticides. The resistance levels to four insecticides were determined among populations from different regions of Sichuan Province, China, using a drop-method bioassay. Based on LC50 values of a laboratory susceptible strain, all field populations showed moderate level of resistance to triazophos (23.9- to 83.5-fold) and were either susceptible or had a low level of resistance to abamectin (2.1- to 5.8-fold). All field-collected populations had a low or moderate level of resistance to chlorpyrifos (1.7- to 47.1-fold) and monosultap (2.7- to 13.5-fold). The synergism experiment indicated that the resistance of the XW19 to triazophos may be associated with cytochrome P450 monooxygenases (P450s), with the highest synergistic ratio (SR) of 3.05-fold and increased ratio (IR) of 2.28-fold for piperonylbutoxide (PBO). The P450 activity of the TJ19 population was the greatest among the six field populations. Moreover, the relative expression levels of four resistance-related P450 genes were detected with qRT-PCR, and the results indicated that CYP324A12, CYP321F3 and CYP9A68 were overexpressed in the resistant population, especially in the XW19 population (by 1.2-, 3.4 -, and 18.0-fold, respectively). In addition, the relative expression levels of CYP9A68 among the CZ19 and TJ19 populations were also enhanced 10.5- and 24.9-fold, respectively. These results suggested that CYP324A12, CYP321F3 and CYP9A68 may be related to the resistance development of C. suppressalis to triazophos.


Assuntos
Clorpirifos , Inseticidas , Lepidópteros , Mariposas , Oryza , Animais , China , Clorpirifos/farmacologia , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Mariposas/genética , Oryza/genética
5.
World J Gastroenterol ; 26(40): 6250-6259, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33177797

RESUMO

BACKGROUND: Pancreatic adenoma can potentially transform into adenocarcinoma, so it is recommended to be resected surgically or endoscopically. Endoscopic papillectomy is one of the main treatments for papillary adenoma, and bleeding, perforation, and pancreatitis are the most frequent and critical adverse events that restrict its wider use. There is no standard procedure for endoscopic papillectomy yet. The procedure is relevant to postoperative adverse events. AIM: To reduce the postoperative adverse event rates and improve patients' postoperative condition, we developed a standard novel procedure for endoscopic papillectomy. METHODS: The novel endoscopic papillectomy had two main modifications based on the conventional method: The isolation of bile from pancreatic juice with a bile duct stent and wound surface protection with metal clips and fibrin glue. We performed a single-center retrospective comparison study on the novel and conventional methods to examine the feasibility of the novel method for reducing postoperative adverse events. RESULTS: A total of 76 patients, of whom 23 underwent the novel procedure and 53 underwent the conventional procedure, were retrospectively evaluated in this study. The postoperative bleeding and pancreatitis rates of the novel method were significantly lower than those of the conventional method (0 vs 20.75%, P = 0.028, and 17.4% vs 41.5%, P = 0.042, respectively). After applying the novel method, the most critical adverse event, perforation, was entirely prevented, compared to a prevalence of 5.66% with the conventional method. Several postoperative symptoms, including fever, rapid pulse, and decrease in hemoglobin level, were significantly less frequent in the novel group (P = 0.042, 0.049, and 0.014, respectively). Overall, the total adverse event rate of the novel method was lower (0 vs 24.5%, P = 0.007) than that of the conventional method. CONCLUSION: Patients who underwent the novel procedure had lower postoperative adverse event rates. This study demonstrates the potential efficacy and safety of the novel endoscopic papillectomy in reducing postoperative adverse events.

6.
Sci Rep ; 10(1): 15282, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943656

RESUMO

The temperature-dependent ([Formula: see text]) optical constants of monolayer [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] were investigated through spectroscopic ellipsometry over the spectral range of 0.73-6.42 eV. At room temperature, the spectra of refractive index exhibited several anomalous dispersion features below 800 nm and approached a constant value of 3.5-4.0 in the near-infrared frequency range. With a decrease in temperature, the refractive indices decreased monotonically in the near-infrared region due to the temperature-dependent optical band gap. The thermo-optic coefficients at room temperature had values from [Formula: see text] to [Formula: see text] for monolayer transition metal dichalcogenides at a wavelength of 1200 nm below the optical band gap. The optical band gap increased with a decrease in temperature due to the suppression of electron-phonon interactions. On the basis of first-principles calculations, the observed optical excitations at 4.5 K were appropriately assigned. These results provide basic information for the technological development of monolayer transition metal dichalcogenides-based photonic devices at various temperatures.

7.
Nat Mater ; 19(12): 1300-1306, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32895505

RESUMO

Two-dimensional transition metal dichalcogenide nanoribbons are touted as the future extreme device downscaling for advanced logic and memory devices but remain a formidable synthetic challenge. Here, we demonstrate a ledge-directed epitaxy (LDE) of dense arrays of continuous, self-aligned, monolayer and single-crystalline MoS2 nanoribbons on ß-gallium (III) oxide (ß-Ga2O3) (100) substrates. LDE MoS2 nanoribbons have spatial uniformity over a long range and transport characteristics on par with those seen in exfoliated benchmarks. Prototype MoS2-nanoribbon-based field-effect transistors exhibit high on/off ratios of 108 and an averaged room temperature electron mobility of 65 cm2 V-1 s-1. The MoS2 nanoribbons can be readily transferred to arbitrary substrates while the underlying ß-Ga2O3 can be reused after mechanical exfoliation. We further demonstrate LDE as a versatile epitaxy platform for the growth of p-type WSe2 nanoribbons and lateral heterostructures made of p-WSe2 and n-MoS2 nanoribbons for futuristic electronics applications.

8.
J Clin Invest ; 130(8): 4301-4319, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32396532

RESUMO

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancers and is highly resistant to current treatments. ESCC harbors a subpopulation of cells exhibiting cancer stem-like cell (CSC) properties that contribute to therapeutic resistance including radioresistance, but the molecular mechanisms in ESCC CSCs are currently unknown. Here, we report that ribosomal S6 protein kinase 4 (RSK4) plays a pivotal role in promoting CSC properties and radioresistance in ESCC. RSK4 was highly expressed in ESCC CSCs and associated with radioresistance and poor survival in patients with ESCC. RSK4 was found to be a direct downstream transcriptional target of ΔNp63α, the main p63 isoform, which is frequently amplified in ESCC. RSK4 activated the ß-catenin signaling pathway through direct phosphorylation of GSK-3ß at Ser9. Pharmacologic inhibition of RSK4 effectively reduced CSC properties and improved radiosensitivity in both nude mouse and patient-derived xenograft models. Collectively, our results strongly suggest that the ΔNp63α/RSK4/GSK-3ß axis plays a key role in driving CSC properties and radioresistance in ESCC, indicating that RSK4 is a promising therapeutic target for ESCC treatment.

10.
ACS Nano ; 14(4): 4963-4972, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32233458

RESUMO

Palladium diselenide (PdSe2), a peculiar noble metal dichalcogenide, has emerged as a new two-dimensional material with high predicted carrier mobility and a widely tunable band gap for device applications. The inherent in-plane anisotropy endowed by the pentagonal structure further renders PdSe2 promising for novel electronic, photonic, and thermoelectric applications. However, the direct synthesis of few-layer PdSe2 is still challenging and rarely reported. Here, we demonstrate that few-layer, single-crystal PdSe2 flakes can be synthesized at a relatively low growth temperature (300 °C) on sapphire substrates using low-pressure chemical vapor deposition (CVD). The well-defined rectangular domain shape and precisely determined layer number of the CVD-grown PdSe2 enable us to investigate their layer-dependent and in-plane anisotropic properties. The experimentally determined layer-dependent band gap shrinkage combined with first-principle calculations suggest that the interlayer interaction is weaker in few-layer PdSe2 in comparison with that in bulk crystals. Field-effect transistors based on the CVD-grown PdSe2 also show performances comparable to those based on exfoliated samples. The low-temperature synthesis method reported here provides a feasible approach to fabricate high-quality few-layer PdSe2 for device applications.

11.
Nanotechnology ; 31(27): 275204, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32208372

RESUMO

A new flexible memory element is crucial for mobile and wearable electronics. A new concept for memory operation and innovative device structure with new materials is certainly required to address the bottleneck of memory applications now and in the future. We report a new nonvolatile molecular memory with a new operating mechanism based on two-dimensional (2D) material nanochannel field-effect transistors (FETs). The smallest channel length for our 2D material nanochannel FETs was approximately 30 nm. The modified molecular configuration for charge induced in the nanochannel of the MoS2 FET can be tuned by applying an up-gate voltage pulse, which can vary the channel conductance to exhibit memory states. Through controlling the amounts of triggered molecules through either different gate voltage pulses or gate duration time, multilevel states were obtained in the molecular memory. These new molecular memory transistors exhibited an erase/program ratio of more than three orders of current magnitude and high sensitivity, of a few picoamperes, at the current level. Reproducible operation and four-level states with stable retention and endurance were achieved. We believe this prototype device has potential for use in future memory devices.

12.
Am J Clin Pathol ; 152(2): 243-252, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31140551

RESUMO

OBJECTIVES: To investigate the role of TNFAIP3 deletions and NF-κB activation in extranodal natural killer/T-cell lymphoma (ENKTCL), nasal type. METHODS: In total, 138 patients with ENKTCL were included. Activation of NF-κB pathway and expression of TNFAIP3 (A20) were examined by immunohistochemistry. TNFAIP3 was analyzed for deletions using FICTION (fluorescence immunophenotyping and interphase cytogenetics as a tool for investigating neoplasms), for mutations using Sanger sequencing, and for promoter methylation using methylation-specific sequencing. RESULTS: NF-κB pathway activation was observed in 31.2% of cases (43/138), TNFAIP3 expression was negative in 15.2% of cases (21/138), and heterozygous TNFAIP3 deletion was observed in 35% of cases (35/100). TNFAIP3 exons 2 to 9 mutations and promoter methylation were not observed. Kaplan-Meier analysis showed patients with NF-κB pathway activation or TNFAIP3 heterozygous deletion to have a longer overall survival. CONCLUSIONS: Our study demonstrated that NF-κB activation and TNFAIP3 heterozygous deletion confer superior survival in patients with ENKTCL.


Assuntos
Linfoma Extranodal de Células T-NK/genética , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Deleção de Genes , Humanos , Linfoma Extranodal de Células T-NK/metabolismo , Linfoma Extranodal de Células T-NK/mortalidade , Linfoma Extranodal de Células T-NK/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Taxa de Sobrevida , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
13.
ACS Nano ; 13(5): 6050-6059, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31074961

RESUMO

Identifying the point defects in 2D materials is important for many applications. Recent studies have proposed that W vacancies are the predominant point defect in 2D WSe2, in contrast to theoretical studies, which predict that chalcogen vacancies are the most likely intrinsic point defects in transition metal dichalcogenide semiconductors. We show using first-principles calculations, scanning tunneling microscopy (STM), and scanning transmission electron microscopy experiments that W vacancies are not present in our CVD-grown 2D WSe2. We predict that O-passivated Se vacancies (OSe) and O interstitials (Oins) are present in 2D WSe2, because of facile O2 dissociation at Se vacancies or due to the presence of WO3 precursors in CVD growth. These defects give STM images in good agreement with experiment. The optical properties of point defects in 2D WSe2 are important because single-photon emission (SPE) from 2D WSe2 has been observed experimentally. While strain gradients funnel the exciton in real space, point defects are necessary for the localization of the exciton at length scales that enable photons to be emitted one at a time. Using state-of-the-art GW-Bethe-Salpeter-equation calculations, we predict that only Oins defects give localized excitons within the energy range of SPE in previous experiments, making them a likely source of previously observed SPE. No other point defects (OSe, Se vacancies, W vacancies, and SeW antisites) give localized excitons in the same energy range. Our predictions suggest ways to realize SPE in related 2D materials and point experimentalists toward other energy ranges for SPE in 2D WSe2.

14.
Int J Biol Macromol ; 134: 1108-1112, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31121224

RESUMO

The combined effects of extrusion (ET) and heat-moisture treatments (EHMT) on the physicochemical properties and in vitro digestibility of corn starch were investigated. Extrusion played a dominant role in reducing relative crystallinity and resistant starch (RS) content, but the swelling power, solubility, rapidly digestible starch (RDS) and slowly digestible starch (SDS) content were increased compared to native starch. EHMT resulted in a decreased swelling power, solubility and a transition in the X-ray diffraction from V- to V+A-type pattern, indicating a structural transformation toward an increased thermodynamic stability. The gelatinization temperatures shifted to higher values while the enthalpy was increased from 1.556 J/g in ET to 3.542 J/g in EHMT. The SDS and RS contents of starch granules were significantly increased, with the latter being increased from 63.03% in ET starch to 71.48% in EHMT starch.


Assuntos
Fenômenos Químicos , Temperatura Alta , Amido/química , Hidrólise , Solubilidade , Análise Espectral , Amido/ultraestrutura , Termodinâmica , Difração de Raios X
15.
Nature ; 567(7747): 169-170, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30862924
16.
Sci Rep ; 8(1): 14947, 2018 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-30297722

RESUMO

Chinese herbal medicines (CHMs) have been used to treat human diseases for thousands of years. Among them, Ginkgo biloba is reported to be beneficial to the nervous system and a potential treatment of neurological disorders. Since the presence of adult neural stem cells (NSCs) brings hope that the brain may heal itself, whether the effect of Ginkgo biloba is on NSCs remains elusive. In this study, we found that Ginkgo biloba extract (GBE) and one of its main ingredients, ginkgolide B (GB) promoted cell cycle exit and neuronal differentiation in NSCs derived from the postnatal subventricular zone (SVZ) of the mouse lateral ventricle. Furthermore, the administration of GB increased the nuclear level of ß-catenin and activated the canonical Wnt pathway. Knockdown of ß-catenin blocked the neurogenic effect of GB, suggesting that GB promotes neuronal differentiation through the Wnt/ß-catenin pathway. Thus, our data provide a potential mechanism underlying the therapeutic effect of GBE or GB on brain injuries and neurodegenerative disorders.


Assuntos
Ginkgolídeos/farmacologia , Lactonas/farmacologia , Ventrículos Laterais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Células Cultivadas , Ventrículos Laterais/efeitos dos fármacos , Ventrículos Laterais/metabolismo , Camundongos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo
17.
Sci Rep ; 8(1): 11398, 2018 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-30061708

RESUMO

Raman scattering measurements of monolayer WS2 are reported as a function of the laser excitation energies from the near-infrared (1.58 eV) to the deep-ultraviolet (4.82 eV). In particular, we observed several strong Raman peaks in the range of 700∼850 cm-1 with the deep-ultraviolet laser lights (4.66 eV and 4.82 eV). Using the first-principles calculations, these peaks and other weak peaks were appropriately assigned by the double resonance Raman scattering spectra of phonons around the M and K points in the hexagonal Brillouin zone. The relative intensity of the first-order [Formula: see text] to A1g peak changes dramatically with the 1.58 eV and 2.33 eV laser excitations, while the comparable relative intensity was observed for other laser energies. The disappearance of the [Formula: see text] peak with the 1.58 eV laser light comes from the fact that valley polarization of the laser light surpasses the [Formula: see text] mode since the [Formula: see text] mode is the helicity-exchange Raman mode. On the other hand, the disappearance of the A1g peak with the 2.33 eV laser light might be due to the strain effect on the electron-phonon matrix element.

18.
Nano Lett ; 18(8): 5172-5178, 2018 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-29969565

RESUMO

Studies of the ultrafast carrier dynamics of transition metal dichalcogenides have employed spatially averaged measurements, which obfuscate the rich variety of dynamics that originate from the structural heterogeneity of these materials. Here, we employ femtosecond time-resolved photoemission electron microscopy (TR-PEEM) with sub-80 nm spatial resolution to image the ultrafast subpicosecond to picosecond carrier dynamics of monolayer tungsten diselenide (WSe2). The dynamics observed following 2.41 eV pump and 3.61 eV probe occurs on two distinct time scales. The 0.1 ps process is assigned to electron cooling via intervalley scattering, whereas the picosecond dynamics is attributed to exciton-exciton annihilation. The 70 fs decay dynamics observed at negative time delay reflects electronic relaxation from the Γ point. Analysis of the TR-PEEM data furnishes the spatial distributions of the various time constants within a single WSe2 flake. The spatial heterogeneity of the lifetime maps is consistent with increased disorder along the edges of the flake and the presence of nanoscale charge puddles in the interior. Our results indicate the need to go beyond spatially averaged time-resolved measurements to understand the influence of structural heterogeneities on the elementary carrier dynamics of two-dimensional materials.

19.
Planta Med ; 84(18): 1348-1354, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29986352

RESUMO

Phytochemical investigation of ethanol extracts from two Taiwanese collections of Vernonia cinerea resulted in the isolation of eighteen hirsutinolide-type sesquiterpenoids, including seven new ones designated as vernolides E - K (1: -7: ). All structures were determined by a combination of detailed spectroscopic analyses (NMR and MS) and comparison with reported data. In an in vitro anti-inflammatory assay, compounds 3, 7, 9, 11: , and 14: exhibited strong inhibitory activities toward NO production by LPS-induced RAW264.7 macrophages, with IC50 values of 1.18, 0.85, 0.66, 0.71 and 0.45 µM, respectively, without affecting cellular viability at 40 µM. Preliminary structure-activity relationships indicate that the ester groups at C-8 and C-13 may enhance inhibition of NO production.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Óxido Nítrico/biossíntese , Sesquiterpenos/química , Sesquiterpenos/farmacologia , Vernonia/química , Animais , Anti-Inflamatórios não Esteroides/química , Avaliação Pré-Clínica de Medicamentos/métodos , Concentração Inibidora 50 , Lipopolissacarídeos/farmacologia , Espectroscopia de Ressonância Magnética , Camundongos , Estrutura Molecular , Células RAW 264.7 , Espectrometria de Massas por Ionização por Electrospray , Relação Estrutura-Atividade
20.
ACS Appl Mater Interfaces ; 10(18): 15996-16004, 2018 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-29658267

RESUMO

Controlling circularly polarized (CP) states of light is critical to the development of functional devices for key and emerging applications such as display technology and quantum communication, and the compact circular polarization-tunable photon source is one critical element to realize the applications in the chip-scale integrated system. The atomic layers of transition metal dichalcogenides (TMDCs) exhibit intrinsic CP emissions and are potential chiroptical materials for ultrathin CP photon sources. In this work, we demonstrated CP photon sources of TMDCs with device thicknesses approximately 50 nm. CP photoluminescence from the atomic layers of tungsten diselenide (WSe2) was precisely controlled with chiral metamolecules (MMs), and the optical chirality of WSe2 was enhanced more than 4 times by integrating with the MMs. Both the enhanced and reversed circular dichroisms had been achieved. Through integrations of the novel gain material and plasmonic structure which are both low-dimensional, a compact device capable of efficiently manipulating emissions of CP photon was realized. These ultrathin devices are suitable for important applications such as the optical information technology and chip-scale biosensing.

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