Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 75
Filtrar
1.
Opt Lett ; 49(20): 5858-5861, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39404556

RESUMO

We investigate spontaneous symmetry- and antisymmetry-breaking bifurcations of solitons in a nonlinear dual-core waveguide with the pure-quartic dispersion and Kerr nonlinearity. Symmetric, antisymmetric, and asymmetric pure-quartic solitons (PQSs) are found, and their stability domains are identified. The bifurcations for both the symmetric and antisymmetric PQSs are of the supercritical type (alias phase transitions of the second kind). Direct simulations of the perturbed evolution of PQSs corroborate their stability boundaries predicted by the analysis of small perturbations.

2.
Chemistry ; : e202402876, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39350485

RESUMO

Membrane separation has become an indispensable separation technology in social production, playing an important role in drug production, water purification, etc. The key core of membranes lies in achieving efficient and precise sieving between substances. As a result, a typical trade-off arises: highly permeable membranes usually sacrifice selectivity and vice versa. To address this dilemma, long-term research has focused on comprehensive understanding and modelling of synthetic membranes at various scales. A significant advancement in this arena is the advent of three-dimensional covalent organic framework (3D COF) membranes, a novel category of long-range ordered porous organic polymer materials. Characterized by an abundance of interconnected channels, diverse pore wall properties, tunable structures, and robust thermal and chemical resilience, 3D COF membranes offer a promising approach for efficient substance separation. This review undertakes a meticulous investigation of the synthesis and physicochemical properties of 3D COF membranes, accentuating the underlying design principles, fabrication methods, and application attempts. A comprehensive assessment of their research trajectory and current standing in the field of membrane processes is provided. The review culminates in a forward-looking outlook, summarizing future research directions and highlighting the substantial potential of this innovative work to shape the future of efficient membrane separation processes.

3.
BMC Pulm Med ; 24(1): 146, 2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38509516

RESUMO

OBJECTIVE: Transbronchial biopsy is a safe manner with fewer complications than percutaneous transthoracic needle biopsy; however, the current diagnostic yield is still necessitating further improvement. We aimed to evaluate the diagnostic yield of using virtual bronchoscopic navigation (VBN) and cone-beam CT (CBCT) for transbronchial biopsy and to investigate the factors that affected the diagnostic sensitivity. METHODS: We retrospectively investigated 255 patients who underwent VBN-CBCT-guided transbronchial biopsy at our two centers from May 2021 to April 2022. A total of 228 patients with final diagnoses were studied. Patient characteristics including lesion size, lesion location, presence of bronchus sign, lesion type and imaging tool used were collected and analyzed. Diagnostic yield was reported overall and in groups using different imaging tools. RESULTS: The median size of lesion was 21 mm (range of 15.5-29 mm) with 46.1% less than 2 cm in diameter. Bronchus sign was present in 87.7% of the patients. The overall diagnostic yield was 82.1%, and sensitivity for malignancy was 66.3%. Patients with lesion > 2 cm or with bronchus sign were shown to have a significantly higher diagnostic yield. Four patients had bleeding and no pneumothorax occurred. CONCLUSION: Guided bronchoscopy with VBN and CBCT was an effective diagnostic method and was associated with a high diagnostic yield in a safe manner. In addition, the multivariant analysis suggested that lesion size and presence of bronchus sign could be a predictive factor for successful bronchoscopic diagnosis.


Assuntos
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Estudos Retrospectivos , Biópsia/métodos , Tomografia Computadorizada de Feixe Cônico , Brônquios/patologia , Broncoscopia/métodos
4.
Acta Biochim Biophys Sin (Shanghai) ; 56(7): 1011-1021, 2024 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-38798241

RESUMO

A prominent cause of cancer-related fatalities with a poor prognosis is lung adenocarcinoma (LUAD). KIF5A, a crucial member of the kinesin superfamily, is linked to drug resistance in malignancies. This work aims to investigate the mechanism of KIF5A in docetaxel (DTX) resistance in LUAD cells. The results of bioinformatics analysis, qRT-PCR and western blot analysis show that KIF5A, which is involved in the glycolysis pathway, is highly expressed in LUAD and is positively correlated with glycolysis-related genes. We further verify that silencing of KIF5A inhibits DTX resistance, glycolysis, and lactate production in LUAD cells via cell counting kit-8 (CCK-8), flow cytometry, Seahorse XFe 96, lactate, and glucose assays. Mechanistically, KIF5A promotes DTX resistance in LUAD, and this effect is attenuated upon the addition of an LDHA inhibitor. Chromatin immunoprecipitation and dual-luciferase reporter assays reveal that FOXP3 transcriptionally activates KIF5A. Knockdown of FOXP3 reduces lactate production and enhances DTX sensitivity in LUAD, which is restored upon simultaneous overexpression of KIF5A. Our findings reveal that FOXP3 increases DTX resistance in LUAD cells by enhancing lactate production through the upregulation of KIF5A level. In conclusion, our study provides a novel treatment target for improving chemosensitivity in LUAD.


Assuntos
Adenocarcinoma de Pulmão , Docetaxel , Resistencia a Medicamentos Antineoplásicos , Fatores de Transcrição Forkhead , Cinesinas , Ácido Láctico , Neoplasias Pulmonares , Cinesinas/genética , Cinesinas/metabolismo , Humanos , Resistencia a Medicamentos Antineoplásicos/genética , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Docetaxel/farmacologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Ácido Láctico/metabolismo , Linhagem Celular Tumoral , Fatores de Transcrição Forkhead/metabolismo , Fatores de Transcrição Forkhead/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Antineoplásicos/farmacologia , Glicólise/efeitos dos fármacos , Glicólise/genética
5.
Biochem Genet ; 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38446321

RESUMO

Current literatures suggest a growing body of evidence highlighting the pivotal role of Immunogenic Cell Death (ICD) in multiple tumor types. Nevertheless, the potential and mechanisms of ICD in diffuse large B-cell lymphoma (DLBCL) remain inadequately studied. To address this gap, our current study aims to examine the impact of ICD on DLBCL and identify a corresponding gene signature in DLBC. Using the expression profiles of ICD-associated genes, the gene expression omnibus (GEO) samples were segregated into ICD-high and ICD-low subtypes utilizing non-negative matrix factorization clustering. Next, univariate and LASSO Cox regression analyses were employed to establish the ICD-related gene signature. Subsequently, the CIBERSORT tool, ssGSEA, and ESTIMATE algorithm were utilized to examine the association between the signature and tumor immune microenvironment of DLBC. Finally, the oncoPredict algorithm was implemented to evaluate the drug sensitivity prediction of DLBCL patients. These findings suggest that the immune microenvironment of the ICD-high group with a poor prognosis was significantly suppressed. An 8-gene ICD-related signature was identified and validated to prognosticate and evaluate the tumor immune microenvironment in DLBCL. Similarly, the high-risk group exhibited a worse prognosis compared to the low-risk group, and the immune function was considerably suppressed. Moreover, the results of oncoPredict algorithm indicated that patients in the high-risk group exhibited higher sensitivity to Cisplatin, Cytarabine, Epirubicin, Oxaliplatin, and Vincristine with low IC50. In conclusion, the present study provides novel insights into the role of ICD in DLBCL by identifying a new biomarker for the disease and may have implications for the development of immune-targeted therapies for the tumor.

6.
Angew Chem Int Ed Engl ; 63(4): e202316315, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38030580

RESUMO

Covalent organic framework (COF) membranes featuring uniform topological structures and devisable functions, show huge potential in water purification and molecular separation. Nevertheless, the inability of uniform COF membranes to be produced on an industrial scale and their nonenvironmentally friendly fabrication method are the bottleneck preventing their industrial applications. Herein, we report a new green and industrially adaptable scraping-assisted interfacial polymerization (SAIP) technique to fabricate scalable and uniform TpPa COF membranes. The process used non-toxic and low-volatility ionic liquids (ILs) as organic phase instead of conventional organic solvents for interfacial synthesis of TpPa COF layer on a support membrane, which can simultaneously achieve the purposes of (i) improving the greenness of membrane-forming process and (ii) fabricating a robust membrane that can function beyond the conventional membranes. This approach yields a large-area, continuous COF membrane (19×25 cm2 ) with a thickness of 78 nm within a brief period of 2 minutes. The resulting membrane exhibited an unprecedented combination of high permeance (48.09 L m-2 h-1 bar-1 ) and antibiotic desalination efficiency (e.g., NaCl/adriamycin separation factor of 41.8), which is superior to the commercial benchmarking membranes.

7.
Angew Chem Int Ed Engl ; 63(23): e202402509, 2024 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-38588046

RESUMO

Membranes are important in the pharmaceutical industry for the separation of antibiotics and salts. However, its widespread adoption has been hindered by limited control of the membrane microstructure (pore architecture and free-volume elements), separation threshold, scalability, and operational stability. In this study, 4,4',4'',4'''-methanetetrayltetrakis(benzene-1,2-diamine) (MTLB) as prepared as a molecular building block for fabricating thin-film composite membranes (TFCMs) via interfacial polymerization. The relatively large molecular size and rigid molecular structure of MTLB, along with its non-coplanar and distorted conformation, produced thin and defect-free selective layers (~27 nm) with ideal microporosities for antibiotic desalination. These structural advantages yielded an unprecedented high performance with a water permeance of 45.2 L m-2 h-1 bar-1 and efficient antibiotic desalination (NaCl/adriamycin selectivity of 422). We demonstrated the feasibility of the industrial scaling of the membrane into a spiral-wound module (with an effective area of 2.0 m2). This module exhibited long-term stability and performance that surpassed those of state-of-the-art membranes used for antibiotic desalination. This study provides a scientific reference for the development of high-performance TFCMs for water purification and desalination in the pharmaceutical industry.


Assuntos
Antibacterianos , Membranas Artificiais , Nylons , Antibacterianos/química , Antibacterianos/isolamento & purificação , Nylons/química , Purificação da Água/métodos , Filtração/métodos , Permeabilidade
8.
Biochemistry ; 62(13): 2021-2028, 2023 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-37319348

RESUMO

Liquid-liquid phase separation (LLPS) plays a key role in the regulation of life activities. Here, we reported a protein from Synechocystis sp. PCC 6803 and annotated as Slr0280. To obtain a water-soluble protein, we deleted the N-terminus transmembrane domain and named it Slr0280Δ. Slr0280Δ with high concentration can undergo LLPS at a low temperature in vitro. It belongs to the phosphodiester glycosidase family of proteins and has a segment of a low-complexity sequence region (LCR), which is thought to regulate the LLPS. Our results show that electrostatic interactions impact the LLPS of Slr0280Δ. We also acquired the structure of Slr0280Δ, which has many grooves on the surface with a large distribution of positive and negative charges. This may be advantageous for the LLPS of Slr0280Δ through electrostatic interactions. Furthermore, the conserved amino acid (arginine at position 531) located on the LCR is important for maintaining the stability of Slr0280Δ as well as LLPS. Our research indicated that the LLPS of proteins can be transformed into aggregation by changing the surface charge distribution.


Assuntos
Domínios Proteicos
9.
J Vis ; 23(13): 2, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37917052

RESUMO

Although visual feature estimations are accurate and precise, overall estimation errors (i.e., the difference between estimates and actual values) tend to show systematic patterns. For example, estimates of orientations are systematically biased away from horizontal and vertical orientations, showing an oblique illusion. Additionally, many recent studies have demonstrated that estimations of current visual features are systematically biased toward previously seen features, showing a serial dependence. However, no study examined whether the overall estimation errors were correlated with the serial dependence bias. To address this question, we enrolled three groups of participants to estimate orientation, motion speed, and point-light-walker direction. The results showed that the serial dependence bias explained over 20% of overall estimation errors in the three tasks, indicating that we could use the serial dependence bias to predict the overall estimation errors. The current study first demonstrated that the serial dependence bias was not independent from the overall estimation errors. This finding could inspire researchers to investigate the neural bases underlying the visual feature estimation and serial dependence.


Assuntos
Ilusões , Percepção Visual , Humanos , Viés , Movimento (Física)
10.
Eur J Cancer Care (Engl) ; 31(6): e13740, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36239065

RESUMO

OBJECTIVE: We evaluate cost-effectiveness of primary treatments for localised prostate cancer by uniquely combining prospectively collected real-world outcomes and costs from UCSF Cancer of Prostate Strategic Urologic Research Endeavor (CaPSURE™). METHODS: Markov models assessed cost-effectiveness of radical prostatectomy (RP), brachytherapy, electron beam radiation therapy (EBRT) and brachytherapy with EBRT by risk from US payers perspective over 8 years. Treatment costs included office visits, hospitalisation, procedures, medication and long-term care. Patients' surveyed HRQoL were mapped into utilities. Incremental cost-effectiveness ratios (ICERs) used cost per quality-adjusted life years (QALYs) and willingness-to-pay of $150,000/QALY. RESULTS: Cost-effectiveness analysis (CEA) showed for low-risk prostate cancer, EBRT dominated the lowest cost brachytherapy, but RPns and brachytherapy plus EBRT were cost-effective compared to brachytherapy with ICERs of $18,926 and $41,662 per QALY. In medium-risk patients, RP, EBRT and brachytherapy plus EBRT all were cost-effective compared with brachytherapy, with ICERs of $30,604, $22,588 and $21,627/QALY. In high-risk, brachytherapy dominated all treatments. Procedure cost and utility are driving ICER, but probabilistic sensitivity analysis showed the model was robust across variables. CONCLUSION: This first CEA combining prospective real-world evidence for HRQOL outcomes with costs shows cost-effectiveness of treatments vary by risk groups, providing new evidence for treatment decisions.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Análise Custo-Benefício , Estudos Prospectivos , Neoplasias da Próstata/terapia , Anos de Vida Ajustados por Qualidade de Vida , Prostatectomia
11.
Nano Lett ; 21(2): 907-913, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33416335

RESUMO

Lithium batteries that could be charged on exposure to sunlight will bring exciting new energy storage technologies. Here, we report a photorechargeable lithium battery employing nature-derived organic molecules as a photoactive and lithium storage electrode material. By absorbing sunlight of a desired frequency, lithiated tetrakislawsone electrodes generate electron-hole pairs. The holes oxidize the lithiated tetrakislawsone to tetrakislawsone while the generated electrons flow from the tetrakislawsone cathode to the Li metal anode. During electrochemical operation, the observed rise in charging current, specific capacity, and Coulombic efficiency under light irradiation in contrast to the absence of light indicates that the quinone-based organic electrode is acting as both photoactive and lithium storage material. Careful selection of electrode materials with optimal bandgap to absorb the intended frequency of sunlight and functional groups to accept Li-ions reversibly is a key to the progress of solar rechargeable batteries.

12.
Nano Lett ; 20(3): 2087-2093, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-31990568

RESUMO

Dimers, two closely spaced metallic nanostructures, are one of the primary nanoscale geometries in plasmonics, supporting high local field enhancements in their interparticle junction under excitation of their hybridized "bonding" plasmon. However, when a dimer is fabricated on a metallic substrate, its characteristics are changed profoundly. Here we examine the properties of a Au dimer on a Au substrate. This structure supports a bright "bonding" dimer plasmon, screened by the metal, and a lower energy magnetic charge transfer plasmon. Changing the dielectric environment of the dimer-on-film structure reveals a broad family of higher-order hybrid plasmons in the visible region of the spectrum. Both of the localized surface plasmons resonances (LSPR) of the individual dimer-on-film structures as well as their collective surface lattice resonances (SLR) show a highly sensitive refractive index sensing response. Implementation of such all-metal magnetic-resonant nanostructures offers a promising route to achieve higher-performance LSPR- and SLR-based plasmonic sensors.

13.
Med Sci Monit ; 26: e923210, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32502142

RESUMO

BACKGROUND The aim of this study was to investigate the expression of tumor-derived exosomal RNA eIF4E (exo-eIF4E) in non-small cell lung cancer (NSCLC) and its correlation with prognosis. MATERIAL AND METHODS The Cancer Genome Atlas (TCGA) data was exacted to investigate the role of tissue eIF4E in NSCLC. We enrolled 99 NSCLC patients and 40 healthy volunteers with corresponding serum samples in this study. The levels of exo-eIF4E in the peripheral blood of each group were tested by quantitative polymerase chain reaction (PCR). The chi-squared test and the log-rank test were applied to analyze the correlation between the expression levels of exo-eIF4E and the patients' clinical-pathological data, including the overall survival. RESULTS TCGA data showed that increased eIF4E in NSCLC tissues was associated with late-stage disease (P=0.0497) and inferior overall survival (P=0.017). The expression of exo-eIF4E in the serum of the NSCLC group was significantly higher than that in healthy individuals (P<0.001). Furthermore, advanced TNM stage (P=0.003), distant metastasis (P=0.008), and serum positive cytokeratin fragment 19 (CYFRA21-1) (P=0.023) are more likely present in NSCLC patients with higher exo-eIF4E expression. Moreover, the multivariate combined with univariate analyses verified exo-eIF4E as an independent prognostic factor for shorter overall survival (P=0.01) and progression-free survival (P=0.005). Shorter overall survival (P=0.0005) and inferior progression-free survival (P=0.0017) are more likely present in NSCLC patients with higher exo-eIF4E. CONCLUSIONS Tumor-derived exo-eIF4E in serum can be a practical tool to predict the prognosis of NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Fator de Iniciação 4E em Eucariotos/genética , Exossomos/genética , Neoplasias Pulmonares/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/epidemiologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , China/epidemiologia , Bases de Dados Genéticas , Fator de Iniciação 4E em Eucariotos/metabolismo , Exossomos/metabolismo , Feminino , Humanos , Estimativa de Kaplan-Meier , Neoplasias Pulmonares/epidemiologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Prognóstico , Transcriptoma
14.
Nano Lett ; 19(1): 605-611, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30575385

RESUMO

The harmonic generation of light with plasmonic and all-dielectric nanostructures has gained much recent interest. This approach is especially promising for short wavelength (i.e., ultraviolet (UV)) generation, where conventional nonlinear crystals reach their limits both in transparency and in their ability to achieve phase-matching between the input and output fields. Here, we demonstrate that the third harmonic generation of deep UV light in an indium tin oxide (ITO) film can be substantially enhanced by a metasurface consisting of metallic toroidal meta-atoms covered with an alumina layer for protection against laser-induced damage. This approach combines the benefits of the large nonlinear susceptibility of ITO with the unique field enhancement properties of a toroidal metasurface. This ITO-meta-atom combination produces a third harmonic signal at a wavelength of 262 nm that is nominally five times larger than that of an ITO film patterned with a conventional hotspot-enhanced plasmonic dimer array. This result demonstrates the potential for toroidal meta-atoms as the active engineered element in a new generation of enhanced nonlinear optical materials and devices.

15.
Nano Lett ; 19(7): 4413-4419, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31244226

RESUMO

Plasmonic photocatalytic processes typically use the interaction of light with metallic nanoparticles to drive chemical reactions on their surfaces. Here we show that a plasmonic photocatalyst can also induce a reaction on an adjacent material. A combination of spontaneous H2 dissociation and plasmon-induced H desorption from tilted palladium (Pd) nanocones yields reactive H atoms which, in the direct vicinity of a graphene monolayer, results in its local hydrogenation. The conversion of pristine to hydrogenated graphene, a semiconductor, is detectable by visible local fluorescence of the hydrogenated regions of the graphene sheet, as well as by Raman spectroscopic analysis. These results may lead to new approaches for local, light-driven functionalization of graphene and other 2D materials and for precision patterning of functional devices.

16.
Nano Lett ; 18(10): 6509-6514, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30180595

RESUMO

The optical reshaping of metallic nanostructures typically requires intense laser pulses to first approach or achieve melting, followed by surface-tension-dominated reshaping, transforming the original nanostructures into more spherical morphologies. Here, we report the directional optical reshaping of the Au nanodisk of an Al-Au heterodimer in the illuminated junction of an atomic force microscope (AFM). Both the heightening and the repositioning of the Au nanodisk component are induced, reducing the gap between the two nanodisks. There are three contributors to this process: the photothermal softening of the Au lattice, the optical force applied to the Au nanodisk by the Al nanodisk, and the optical force from the nearby AFM tip. The asymmetric reshaping of the heterodimer is observable structurally, through electron microscopic imaging, and through changes in the heterodimer optical response. This optical-force-directed shape manipulation may have potential applications in nanofabrication, optically induced nanomanufacturing, sensing, and quality control.

17.
Respir Res ; 19(1): 254, 2018 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-30547791

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) is related to inflammation, and the lncRNA H19 is associated with inflammation. However, whether PDGF-BB-H19-let-7b-AT1R axis contributes to the pathogenesis of PAH has not been thoroughly elucidated to date. This study investigated the role of H19 in PAH and its related mechanism. METHODS: In the present study, SD rats, C57/BL6 mice and H19-/- mice were injected with monocrotaline (MCT) to establish a PAH model. H19 was detected in the cytokine-stimulated pulmonary arterial smooth muscle cells (PASMCs), serum and lungs of rats/mice. H19 overexpression and knockdown experiments were also conducted. A dual luciferase reporter assay was used to explore whether let-7b is a sponge miRNA of H19, and AT1R is a novel target of let-7b. A CCK-8 assay and flow cytometry were used to analyse cell proliferation. RESULTS: The results showed that H19 was highly expressed in the serum and lungs of MCT-induced rats/mice, and H19 was upregulated by PDGF-BB in vitro. H19 upregulated AT1R expression via sponging miRNA let-7b following PDGF-BB stimulation. AT1R is a novel target of let-7b. Moreover, the overexpression of H19 and AT1R could facilitate PASMCs proliferation in vitro. H19 knockout protected mice from pulmonary artery remodeling and PAH following MCT treatment. CONCLUSION: Our study showed that H19 is highly expressed in MCT-induced rodent lungs and upregulated by PDGF-BB. The H19-let-7b-AT1R axis contributed to the pathogenesis of PAH by stimulating PASMCs proliferation. The H19 knockout had a protective role in the development of PAH. H19 may be a potential tar-get for the treatment of PAH.


Assuntos
Hipertensão Pulmonar/metabolismo , MicroRNAs/biossíntese , Monocrotalina/toxicidade , Miócitos de Músculo Liso/metabolismo , RNA Longo não Codificante/biossíntese , Receptores de Angiotensina/biossíntese , Indutores da Angiogênese/farmacologia , Animais , Becaplermina/farmacologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Hipertensão Pulmonar/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos de Músculo Liso/efeitos dos fármacos , Artéria Pulmonar/efeitos dos fármacos , Artéria Pulmonar/metabolismo , RNA Longo não Codificante/agonistas , Ratos , Ratos Sprague-Dawley
18.
Nano Lett ; 17(9): 5768-5774, 2017 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-28787169

RESUMO

Surface-enhanced infrared absorption (SEIRA) spectroscopy has outstanding potential in chemical detection as a complement to surface-enhanced Raman spectroscopy (SERS), yet it has historically lagged well behind SERS in detection sensitivity. Here we report a new ultrasensitive infrared antenna designed to bring SEIRA spectroscopy into the few-molecule detection range. Our antenna consists of a bowtie-shaped Au structure with a sub-3 nm gap, positioned to create a cavity above a reflective substrate. This three-dimensional geometry tightly confines incident mid-infrared radiation into its ultrasmall junction, yielding a hot spot with a theoretical SEIRA enhancement factor of more than 107, which can be designed to span the range of frequencies useful for SEIRA. We quantitatively evaluated the IR detection limit of this antenna design using mixed monolayers of 4-nitrothiophenol (4-NTP) and 4-methoxythiolphenol (4-MTP). The optimized antenna structure allows the detection of as few as ∼500 molecules of 4-NTP and ∼600 molecules of 4-MTP with a standard commercial FTIR spectrometer. This strategy offers a new platform for analyzing the IR vibrations of minute quantities of molecules and lends insight into the ultimate limit of single-molecule SEIRA detection.

19.
Nano Lett ; 16(5): 3373-8, 2016 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-27089276

RESUMO

Active optical processes such as amplification and stimulated emission promise to play just as important a role in nanoscale optics as they have in mainstream modern optics. The ability of metallic nanostructures to enhance optical nonlinearities at the nanoscale has been shown for a number of nonlinear and active processes; however, one important process yet to be seen is optical parametric amplification. Here, we report the demonstration of surface plasmon-enhanced difference frequency generation by integration of a nonlinear optical medium, BaTiO3, in nanocrystalline form within a plasmonic nanocavity. These nanoengineered composite structures support resonances at pump, signal, and idler frequencies, providing large enhancements of the confined fields and efficient coupling of the wavelength-converted idler radiation to the far-field. This nanocomplex works as a nanoscale tunable infrared light source and paves the way for the design and fabrication of a surface plasmon-enhanced optical parametric amplifier.

20.
Nano Lett ; 16(10): 6677-6682, 2016 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-27676189

RESUMO

Photocatalysis uses light energy to drive chemical reactions. Conventional industrial catalysts are made of transition metal nanoparticles that interact only weakly with light, while metals such as Au, Ag, and Al that support surface plasmons interact strongly with light but are poor catalysts. By combining plasmonic and catalytic metal nanoparticles, the plasmonic "antenna" can couple light into the catalytic "reactor". This interaction induces an optical polarization in the reactor nanoparticle, forcing a plasmonic response. When this "forced plasmon" decays it can generate hot carriers, converting the catalyst into a photocatalyst. Here we show that precisely oriented, strongly coupled Al-Pd nanodisk heterodimers fabricated using nanoscale lithography can function as directional antenna-reactor photocatalyst complexes. The light-induced hydrogen dissociation rate on these structures is strongly dependent upon the polarization angle of the incident light with respect to the orientation of the antenna-reactor pair. Their high degree of structural precision allows us to microscopically quantify the photocatalytic activity per heterostructure, providing precise photocatalytic quantum efficiencies. This is the first example of precisely designed heterometallic nanostructure complexes for plasmon-enabled photocatalysis and paves the way for high-efficiency plasmonic photocatalysts by modular design.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa