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1.
Plant Physiol ; 2024 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-38828881

RESUMEN

Plants recognize a variety of external signals and induce appropriate mechanisms to increase their tolerance to biotic and abiotic stresses. Precise recognition of attacking pathogens and induction of effective resistance mechanisms are critical functions for plant survival. Some molecular patterns unique to a certain group of microbes, microbe-associated molecular patterns (MAMPs), are sensed by plant cells as nonself molecules via pattern recognition receptors. While MAMPs of bacterial and fungal origin have been identified, reports on oomycete MAMPs are relatively limited. This study aimed to identify MAMPs from an oomycete pathogen Phytophthora infestans, the causal agent of potato late blight. Using reactive oxygen species (ROS) production and phytoalexin production in potato (Solanum tuberosum) as markers, two structurally different groups of elicitors, namely ceramides and diacylglycerols, were identified. P. infestans ceramides (Pi-Cer A, B, and D) induced ROS production, while diacylglycerol (Pi-DAG A and B), containing eicosapentaenoic acid (EPA) as a substructure, induced phytoalexins production in potato. The molecular patterns in Pi-Cers and Pi-DAGs essential for defense induction were identified as 9-methyl-4,8-sphingadienine (9Me-Spd) and 5,8,11,14-tetraene-type fatty acid (5,8,11,14-TEFA), respectively. These structures are not found in plants, but in oomycetes and fungi, indicating that they are microbe molecular patterns recognized by plants. When Arabidopsis (Arabidopsis thaliana) was treated with Pi-Cer D and EPA, partially overlapping but different sets of genes were induced. Furthermore, expression of some genes is upregulated only after the simultaneous treatment with Pi-Cer D and EPA, indicating that plants combine the signals from simultaneously recognized MAMPs to adapt their defense response to pathogens.

2.
Fungal Genet Biol ; 172: 103895, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38679292

RESUMEN

Botrytis cinerea is a necrotrophic pathogen that infects across a broad range of plant hosts, including high-impact crop species. Its generalist necrotrophic behavior stems from its ability to detoxify structurally diverse phytoalexins. The current study aims to provide evidence of the ability of B. cinerea to tolerate the sesquiterpenoid phytoalexin rishitin, which is produced by potato and tomato. While the growth of potato pathogens Phytophthora infestans (late blight) and Alternaria solani (early blight) was severely inhibited by rishitin, B. cinerea was tolerant to rishitin. After incubation of rishitin with the mycelia of B. cinerea, it was metabolized to at least six oxidized forms. Structural analysis of these purified rishitin metabolites revealed a variety of oxidative metabolism including hydroxylation at C7 or C12, ketone formation at C5, and dihydroxylation at the 10,11-olefin. Six rishitin metabolites showed reduced toxicity to P. infestans and A. solani, indicating that B. cinerea has at least 5 distinct enzymatic reactions to detoxify rishitin. Four host-specialized phytopathogenic Botrytis species, namely B. elliptica, B. allii, B. squamosa, and B. tulipae also had at least a partial ability to metabolize rishitin as B. cinerea, but their metabolic capacity was significantly weaker than that of B. cinerea. These results suggest that the ability of B. cinerea to rapidly metabolize rishitin through multiple detoxification mechanisms could be critical for its pathogenicity in potato and tomato.


Asunto(s)
Botrytis , Fitoalexinas , Phytophthora infestans , Enfermedades de las Plantas , Sesquiterpenos , Botrytis/metabolismo , Botrytis/genética , Botrytis/efectos de los fármacos , Sesquiterpenos/metabolismo , Enfermedades de las Plantas/microbiología , Phytophthora infestans/metabolismo , Phytophthora infestans/genética , Phytophthora infestans/crecimiento & desarrollo , Phytophthora infestans/efectos de los fármacos , Solanum lycopersicum/microbiología , Inactivación Metabólica , Alternaria/metabolismo , Alternaria/genética , Redes y Vías Metabólicas , Solanum tuberosum/microbiología
3.
Anal Chem ; 93(6): 3202-3208, 2021 02 16.
Artículo en Inglés | MEDLINE | ID: mdl-33539072

RESUMEN

We report photothermal phase separation of aqueous poly(N-isopropylacrylamide) (PNIPAM)/1-butanol (BuOH) solutions by focused 1064 nm laser irradiation and subsequent single microparticle formation in the solution. The single microparticle [diameter = ∼10 µm and volume = ∼picoliter (pL)] produced by laser irradiation was optically trapped by the incident 1064 nm laser beam, and this enabled us in situ Raman/fluorescence microspectroscopies of the particle. Raman spectroscopy demonstrated that the particle produced by laser irradiation was composed of PNIPAM and BuOH. In the presence of rhodamine B (RhB) in the solution, RhB was distributed from the water phase to the PNIPAM/BuOH microparticle produced by laser irradiation, as confirmed by fluorescence microspectroscopy. Laser-induced distribution/extraction of RhB to a single PNIPAM/BuOH microparticle was shown to be possible at the RhB concentration as low as 10-14 mol/dm3, where the RhB fluorescence intensity from the particle showed a step-by-step increase by every ∼3 min laser irradiation. This is the first demonstration of laser-induced simultaneous extraction and detection of single RhB molecules in solution.

4.
Anal Chem ; 93(12): 5218-5224, 2021 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-33724784

RESUMEN

Optical trapping-polarized Raman microspectroscopy of single ethanol (EtOH) microdroplets with a diameter (d) of 6.1-16.5 µm levitated in an EtOH vapor-saturated air/N2 gas atmosphere has been explored to elucidate the vibrational and rotational motions of EtOH in the droplets at 22.0 °C. The Raman spectral bandwidth of the C-C stretching vibrational mode observed for an aerosol EtOH microdroplet was narrower than that of bulk EtOH, suggesting that the vibrational/rotational motions of EtOH in the aerosol system were restricted compared to those in the bulk system. In practice, polarized Raman microspectroscopy demonstrated that the rotational relaxation time (τrot) of EtOH in an aerosol microdroplet with d = 16. 5 µm was slower (2.33 ps) than that in a bulk EtOH (1.65 ps), while the vibrational relaxation times (τvib) in the aerosol and bulk EtOH systems were almost comparable with one another: 0.86-0.98 ps. Furthermore, although the τvib value of an aerosol EtOH microdroplet was almost unchanged irrespective of d as described above, the τrot value increased from 2.33 to 3.57 ps with a decrease in d from 16.5 to 6.1 µm, which corresponded to the increase in EtOH viscosity (η) from 1.33 to 2.04 cP with the decrease in d. The droplet size dependences of τrot and η in an aerosol EtOH microdroplet were discussed in terms of the gas/droplet interfacial molecular arrangements of EtOH and Laplace pressure experienced by a spherical EtOH microdroplet in the gas phase.

5.
Biosci Biotechnol Biochem ; 85(2): 421-429, 2021 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-33604637

RESUMEN

This study sought to clarify the antiobesity effects of fish oil (FO) in terms of prevention and amelioration. An isocaloric diet composed of lard or FO was given to lean C57BL/6J mice for the study of prevention and high-fat diet-induced obese (DIO) mice for the study of amelioration for 4 weeks. Body weight gain and food efficiency were potently suppressed by FO in lean mice compared to lard diet-fed mice. Uncoupling protein-1 (UCP-1) expression in inguinal white adipose tissue (WAT) was also significantly induced by FO in lean mice. FO also suppressed body weight gain and food efficiency in DIO mice but did not reduce body weight. FO ameliorated liver steatosis in DIO mice by mildly inducing UCP-1 in inguinal WAT. FO suppressed obesity more potently in lean mice than in DIO mice but ameliorated steatosis in the DIO mice.


Asunto(s)
Dieta/efectos adversos , Hígado Graso/complicaciones , Hígado Graso/tratamiento farmacológico , Aceites de Pescado/farmacología , Obesidad/tratamiento farmacológico , Animales , Aceites de Pescado/uso terapéutico , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Obesidad/inducido químicamente , Obesidad/complicaciones
6.
J Phys Chem A ; 124(43): 9035-9043, 2020 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-33054224

RESUMEN

We report temperature (T = +22.5 ∼ -57.0 °C)-controlled optical trapping of single dimethylsulfoxide (DMSO) droplets with the diameter (d) of 7-15 µm in air. Optically levitated DMSO microdroplets containing 0.1 mol/dm3 (=M) potassium iodide (KI) as an additive for reducing the vapor pressure of DMSO in air have been suggested to take supercooled liquid states even below the freezing temperature (fp) of the bulk DMSO liquid (fp = +18.4 °C in the presence of 0.1 M KI) as seen in bright-field microscopic observations of the droplet. Clear evidence for supercooling of an aerosol DMSO microdroplet below fp has been obtained by in situ optical trapping-polarized Raman microspectroscopy of the droplet down to -14.9 °C. Analysis of the polarized Raman spectral data of an aerosol DMSO droplet (d = ∼10 µm) has demonstrated that the droplet at +22.5, +0.2, or -14.9 °C is characterized by the rotational relaxation time (τrot) of a DMSO molecule in the droplet being 1.95, 2.58, or 3.90 ps, respectively. On the basis of the τrot values and the Stokes-Einstein equation (τrot = 8πa3η/kBT where a, η, kB are the radius (1.883 Å) of a DMSO molecule, the viscosity in DMSO, and the Boltzmann constant, respectively), the η values in the DMSO microdroplet in air at +22.5, +0.2, or -14.9 °C have been estimated to be 2.39, 2.94, or 4.20 cP, respectively, while that of bulk DMSO liquid at +20.5 °C is 1.98 cP. We also report the T-dependence (+22.5 > T > -14.9 °C) of the viscosity in a single aerosol DMSO microdroplet (d = ∼10 µm) and the effects of aerosolization in air on the viscosity in DMSO.

7.
J Chem Phys ; 152(10): 104706, 2020 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-32171196

RESUMEN

Metallic nanogap dimers are extremely useful for enhancing surface-enhanced Raman scattering and various nonlinear optical effects employing near-field enhancement effects induced by the localized surface plasmon resonance. However, the metallic nanogap dimers exhibit an intense light scattering due to the strong dipole-dipole interaction between two metallic nanostructures and, therefore, are not necessarily a structural design that exhibits the highest near-field enhancement due to the radiation loss. Here, we propose further enhancement of the near-field on metallic nanogap dimers using quasi-dark plasmon modes. By coupling with gold (Au) nanorods having the same plasmon resonant wavelength, but completely different sizes, a quasi-dark plasmon mode, which reduces the radiation loss slightly, is induced, resulting in the elongation of the plasmon dephasing time. As a result, the signal of surface-enhanced Raman scattering of crystal violet molecules adsorbed on the Au nanogap dimer is enhanced up to about three times as compared to that measured using the Au nanogap dimer without the Au nanorods. Scattering spectrum measurements as well as electromagnetic simulations were performed to clarify the mechanism for further enhancement of the near-field. The proposed coupled plasmonic system is expected to be advantageous, especially in enhancing nonlinear optical effects using plasmonic enhancement effects.

8.
Gan To Kagaku Ryoho ; 47(12): 1723-1725, 2020 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-33342992

RESUMEN

A 68-year-old woman presenting with anorexia and epigastric pain was diagnosed with metastatic pancreatic cancer and idiopathic thrombocytopenic purpura(ITP). Chemotherapy was initiated with S-1. Subsequently, gemcitabine was administered in combination with prednisolone. Her platelets returned to normal after the treatment with steroids and chemotherapy, but the treatment could not be withdrawn completely. Pancreatic cancer presenting as idiopathic thrombocytopenic purpura has rarely been reported in the literature. Here, we present our experience and discuss a case of pancreatic cancer complicated with ITP.


Asunto(s)
Neoplasias Pancreáticas , Púrpura Trombocitopénica Idiopática , Anciano , Femenino , Humanos , Neoplasias Pancreáticas/complicaciones , Neoplasias Pancreáticas/tratamiento farmacológico , Prednisolona , Púrpura Trombocitopénica Idiopática/complicaciones , Púrpura Trombocitopénica Idiopática/tratamiento farmacológico
9.
J Am Chem Soc ; 140(1): 346-354, 2018 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-29224333

RESUMEN

Plastic crystals represent a unique compound class that is often encountered in molecules with globular structures. The highly symmetric cubic crystal structure of plastic crystals endows these materials with multiaxial ferroelectricity that allows a three-dimensional realignment of the polarization axes of the crystals, which cannot be achieved using conventional molecular ferroelectric crystals with low crystal symmetry. In this work, we focused our attention on malleability as another characteristic feature of plastic crystals. We have synthesized the new plastic/ferroelectric ionic crystals tetramethylammonium tetrachloroferrate(III) and tetramethylammonium bromotrichloroferrate(III), and discovered that free-standing translucent films can be easily prepared by pressing powdered samples of these compounds. The thus obtained polycrystalline films exhibit ferroelectric polarization switching and a relatively large piezoelectric response at room temperature. The ready availability of functional films demonstrates the practical utility of such plastic/ferroelectric crystals, and considering the vast variety of possible constituent cations and anions, a wide range of applications should be expected for these unique and attractive functional materials.

10.
Nano Lett ; 17(7): 4347-4353, 2017 07 12.
Artículo en Inglés | MEDLINE | ID: mdl-28594564

RESUMEN

Dynamic control of electromagnetic heat transfer without changing mechanical configuration opens possibilities in intelligent thermal management in nanoscale systems. We confirmed by experiment that the radiative heat transfer is dynamically modulated beyond the blackbody limit. The near-field electromagnetic heat exchange mediated by phonon-polariton is controlled by the metal-insulator transition of tungsten-doped vanadium dioxide. The functionalized heat flux is transferred over an area of 1.6 cm2 across a 370 nm gap, which is maintained by the microfabricated spacers and applied pressure. The uniformity of the gap is validated by optical interferometry, and the measured heat transfer is well modeled as the sum of the radiative and the parasitic conductive components. The presented methodology to form a nanometric gap with functional heat flux paves the way to the smart thermal management in various scenes ranging from highly integrated systems to macroscopic apparatus.

11.
Nanotechnology ; 28(20): 205303, 2017 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-28445164

RESUMEN

Nanoimprint lithography (NIL) is one of the most prominent bottom-up techniques for duplicating nanostructures with a high throughput. However, fabrication of starting master mold commonly requires expensive equipment of top-down techniques, or additional steps to transfer the fabricated patterns from bottom-up methods. Here we demonstrate that a SiO2 nanostructure manufactured from a self-assembled block copolymer, polystyrene-b-polydimethylsiloxane (PS-b-PDMS), directly serves as a master mold for NIL without further modification. A hexagonally aligned pattern over the entire substrate is established using a simple technique; solvent annealing and etching. Etching also plays an important role in endowing fluorine on the surface of SiO2, thus promoting smooth demolding upon imprinting. The obtained pattern of the SiO2 nanostructure is transferred to a polymer surface using UV nanoimprint. Identical patterns of the SiO2 nanostructure are elaborately reproduced on Ni and Cu nanodot arrays via electroplating on the polymer transcript, which was verified by morphological observations. The uniformity of the replicated Ni nanodot array is evaluated using spectroscopic ellipsometry. The measured optical response of the Ni nanodot is validated by electromagnetically simulated results, indicating that the pattern transfer is not limited to a small local area. In addition, the durability of the SiO2 mold pattern is corroborated after the imprinting process, thus guaranteeing the reusability of the fabricated nanostructure as a master mold. The proposed approach does not require any high-end lithographic techniques; this may result in significant cost and time reductions in future nanofabrication.

12.
Biosci Biotechnol Biochem ; 81(11): 2105-2111, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28914172

RESUMEN

The fibrinolysis system is thought to play an important role in liver regeneration. We previously found that plasminogen (Plg) is localized to the cell surface of regenerating liver tissue as well as proliferating hepatocytes in vitro. Here, we investigated the significance of Plg binding to the cell surface during liver regeneration. Pre-administration of tranexamic acid (TXA), which is a competitive inhibitor of Plg binding, to hepatectomized rats mildly delayed restoration of liver weight in vivo. Although binding of Plg to the cell membrane decreased following TXA administration, TXA showed little effect on hepatocyte proliferation in rats. We also discovered that Plg treatment did not stimulate proliferation of primary rat hepatocytes in vitro. These results suggest that Plg/plasmin potentiates liver regeneration via a pathway distinct from those through which hepatocyte proliferation is stimulated.


Asunto(s)
Regeneración Hepática/efectos de los fármacos , Plasminógeno/metabolismo , Ácido Tranexámico/farmacología , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Proliferación Celular/efectos de los fármacos , Hígado/citología , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/fisiología , Masculino , Unión Proteica/efectos de los fármacos , Ratas , Ratas Wistar
13.
Opt Express ; 22(21): 25362-70, 2014 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-25401570

RESUMEN

We experimentally demonstrate a TiO(2) double-groove grating coupler with two different groove widths on a SiO(2) substrate in the visible region. Tolerance investigations based on Bloch-mode profiles in the grating and coupling strengths between the Bloch modes and diffraction orders reveal that the transmission performance is robust when one of the paired ridges is narrow enough (60 nm and less) considering a typical nanofabrication accuracy. Moreover, the ridge shape affects weakly the transmission performance due to the non-resonance operation of our dielectric device. Such tolerance investigations together with current nanofabrication technology enable us to accomplish a 70% efficiency for coupling the normal incident light into the + 1st order transmission diffraction satisfying the total internal reflection condition at a 640 nm wavelength of operation.


Asunto(s)
Fenómenos Ópticos , Microscopía Electrónica de Rastreo , Modelos Teóricos , Análisis de Ondículas
14.
Opt Lett ; 39(5): 1262-5, 2014 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-24690722

RESUMEN

We demonstrate tunable, enhanced 0th-order transmission through a metal-dielectric nanohole array device with a subwavelength-thick liquid crystal (LC) layer. The LC filled the nanoholes and formed a subwavelength covering layer, which is then capped by a top cover layer. The wavelength where the transmittance dip associated with the LC occurs is determined by the anisotropic refractive-index component of the LC, which is normal to the surface of the hole array. A low-refractive-index cover layer suppresses unwanted higher-order diffraction, which results in an enhancement of the 0th-order transmission, which is closely related to laterally propagating surface plasmon polaritons. The proposed design is expected to help realize tunable plasmonic devices with high optical transmittance.

15.
Opt Express ; 21(5): 6153-61, 2013 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-23482183

RESUMEN

A stacked metal-dielectric hole array (SHA) containing rectangular holes whose shape gradually varies in-plane is proposed as a means of achieving wavefront control. The dependence of the transmitted phase on the frequency can be tuned by the hole shape, in particular the length of the sides that are normal to the incident polarization. The combination of periodic holes along the polarization direction and the gradual change in hole shape normal to the polarization direction produce an inclined wavefront for 1-dimensional beam steering. An in-plane phase difference of 0.6π using an SHA with a thickness of one-sixth of the wavelength has been experimentally demonstrated.

16.
Langmuir ; 29(40): 12483-9, 2013 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-24028443

RESUMEN

The first six peptides of multifunctional titanium binding peptide-1 bestowed recombinant L-ferritin, minT1-LF, was genetically engineered and used to fabricate multilayered nanoparticle architecture. The multifunctionality of minT1-LF enables specific binding of nanoparticle-accommodated minT1-LF to the silicon substrate surface and wet biochemical fabrication of gate oxide layer by its biomineralization activity. Three-dimensional (3D) nanoparticle architecture with multilayered structure was fabricated by the biological layer-by-layer method and embedded in a metal oxide-semiconductor device structure as a charge storage node of a flash memory device. The 3D-integrated multilayered nanoparticle architecture successfully worked as a charge storage node in flash memory devices that exhibited improved charge storage capacity compared with that of a conventional monolayer structure device.


Asunto(s)
Nanoestructuras/química , Microscopía Electrónica de Transmisión , Nanoestructuras/ultraestructura , Semiconductores , Volatilización
17.
Gan To Kagaku Ryoho ; 40(13): 2581-4, 2013 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-24335375

RESUMEN

We report a rare case of a patient with metastatic colorectal cancer who experienced hyperammonemic encephalopathy induced by 5 -fluorouracil(5-FU)and was continuously treated with capecitabine plus oxaliplatin(XELOX)therapy. A 60 years man with anorexia and weight loss was diagnosed with Stage IV rectal cancer, and chemotherapy with XELOX was initiated. When the second course of XELOX therapy was administered, the patient found it difficult to take oral capecitabine. Subsequently, modified FOLFOX6 was administered. Complications such as nausea and vomiting were observed on day 2, with confusion and cognitive disturbances on day 3 . Laboratory examination revealed hyperammonemia, and therefore, branched-chain amino acid solutions were administered as treatment. The patient's symptoms disappeared entirely on day 4. He is currently receiving XELOX therapy.


Asunto(s)
Aminoácidos de Cadena Ramificada/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Encefalopatías Metabólicas/etiología , Fluorouracilo/efectos adversos , Hiperamonemia/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias del Recto/tratamiento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Encefalopatías Metabólicas/tratamiento farmacológico , Capecitabina , Desoxicitidina/administración & dosificación , Desoxicitidina/análogos & derivados , Fluorouracilo/administración & dosificación , Fluorouracilo/análogos & derivados , Fluorouracilo/uso terapéutico , Humanos , Hiperamonemia/inducido químicamente , Neoplasias Hepáticas/secundario , Masculino , Oxaloacetatos , Neoplasias del Recto/patología
18.
Sci Rep ; 13(1): 6440, 2023 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-37081066

RESUMEN

Modified solid surfaces exhibit unique wetting behavior, such as hydrophobicity and hydrophilicity. Such behavior can passively control the fluid flow. In this study, we experimentally demonstrated a wettability-designable cell array consisting of unetched and physically etched surfaces by reactive ion etching on a silicon substrate. The etching process induced a significant surface roughness on the silicon surface. Thus, the unetched and etched surfaces have different wettabilities. By adjusting the ratio between the unetched and etched surface areas, we designed one- and two-dimensional wettability gradients for the fluid channel. Consequently, fine-tuned channels passively realized unidirectional and curved fluid motions. The design of a wettability gradient is crucial for practical and portable systems with integrated fluid channels.

19.
J Vet Med Sci ; 85(12): 1348-1354, 2023 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-37952974

RESUMEN

Helicobacter pylori is a well-known pathogen that causes chronic gastritis, leading to the development of gastric cancer. This bacterium has also been detected in dogs, and symptoms similar to those in humans have been reported. The cytotoxin-associated gene A (CagA) is involved in pathogenesis through aberrant activation of host signal transduction, including the nuclear factor-kappa B (NF-κB) pathway. We have previously shown the anti-inflammatory effect of the G-protein-coupled estrogen receptor (GPER) via inhibiting of NF-κB activation in several cells. Therefore, here, we investigated the effect of GPER on CagA-mediated NF-κB promoter activity and showed that CagA overexpression in gastric cancer cells activated the NF-κB reporter and induced interleukin 8 (il-8) expression, both of which were inhibited by the GPER agonist.


Asunto(s)
Enfermedades de los Perros , Infecciones por Helicobacter , Helicobacter pylori , Neoplasias Gástricas , Animales , Perros , Humanos , Citotoxinas/metabolismo , Enfermedades de los Perros/metabolismo , Mucosa Gástrica/metabolismo , Proteínas de Unión al GTP/metabolismo , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/veterinaria , Helicobacter pylori/genética , Helicobacter pylori/metabolismo , Interleucina-8/genética , FN-kappa B/metabolismo , Receptores de Estrógenos/genética , Receptores de Estrógenos/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/veterinaria
20.
Microsyst Nanoeng ; 9: 32, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36969967

RESUMEN

Nanoscale cantilevers (nanocantilevers) made from carbon nanotubes (CNTs) provide tremendous benefits in sensing and electromagnetic applications. This nanoscale structure is generally fabricated using chemical vapor deposition and/or dielectrophoresis, which contain manual, time-consuming processes such as the placing of additional electrodes and careful observation of single-grown CNTs. Here, we demonstrate a simple and Artificial Intelligence (AI)-assisted method for the efficient fabrication of a massive CNT-based nanocantilever. We used randomly positioned single CNTs on the substrate. The trained deep neural network recognizes the CNTs, measures their positions, and determines the edge of the CNT on which an electrode should be clamped to form a nanocantilever. Our experiments demonstrate that the recognition and measurement processes are automatically completed in 2 s, whereas comparable manual processing requires 12 h. Notwithstanding the small measurement error by the trained network (within 200 nm for 90% of the recognized CNTs), more than 34 nanocantilevers were successfully fabricated in one process. Such high accuracy contributes to the development of a massive field emitter using the CNT-based nanocantilever, in which the output current is obtained with a low applied voltage. We further showed the benefit of fabricating massive CNT-nanocantilever-based field emitters for neuromorphic computing. The activation function, which is a key function in a neural network, was physically realized using an individual CNT-based field emitter. The introduced neural network with the CNT-based field emitters recognized handwritten images successfully. We believe that our method can accelerate the research and development of CNT-based nanocantilevers for realizing promising future applications.

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