Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
Nature ; 592(7852): 54-59, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33790446

RESUMO

Three-dimensional (3D) printing1-9 has revolutionized manufacturing processes for electronics10-12, optics13-15, energy16,17, robotics18, bioengineering19-21 and sensing22. Downscaling 3D printing23 will enable applications that take advantage of the properties of micro- and nanostructures24,25. However, existing techniques for 3D nanoprinting of metals require a polymer-metal mixture, metallic salts or rheological inks, limiting the choice of material and the purity of the resulting structures. Aerosol lithography has previously been used to assemble arrays of high-purity 3D metal nanostructures on a prepatterned substrate26,27, but in limited geometries26-30. Here we introduce a technique for direct 3D printing of arrays of metal nanostructures with flexible geometry and feature sizes down to hundreds of nanometres, using various materials. The printing process occurs in a dry atmosphere, without the need for polymers or inks. Instead, ions and charged aerosol particles are directed onto a dielectric mask containing an array of holes that floats over a biased silicon substrate. The ions accumulate around each hole, generating electrostatic lenses that focus the charged aerosol particles into nanoscale jets. These jets are guided by converged electric-field lines that form under the hole-containing mask, which acts similarly to the nozzle of a conventional 3D printer, enabling 3D printing of aerosol particles onto the silicon substrate. By moving the substrate during printing, we successfully print various 3D structures, including helices, overhanging nanopillars, rings and letters. In addition, to demonstrate the potential applications of our technique, we printed an array of vertical split-ring resonator structures. In combination with other 3D-printing methods, we expect our 3D-nanoprinting technique to enable substantial advances in nanofabrication.

2.
Mol Biol Rep ; 48(2): 1651-1658, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33580460

RESUMO

SVCT2, Sodium-dependent Vitamin C Transporter 2, uniquely transports ascorbic acid (also known as vitamin C and ascorbate) into all types of cells. Vitamin C is an essential nutrient that must be obtained through the diet and plasma levels are tightly regulated by transporter activity. Vitamin C plays an important role in antioxidant defenses and is a cofactor for many enzymes that enable hormone synthesis, oxygen sensing, collagen synthesis and epigenetic pathways. Although SVCT2 has various functions, regulation of its expression/activity remains poorly understood. We found a p53-binding site, within the SVCT2 promoter, using a transcription factor binding-site prediction tool. In this study, we show that p53 can directly repress SVCT2 transcription by binding a proximal- (~-185 to -171 bp) and a distal- (~-1800 to -1787 bp) p53-responsive element (PRE), Chromatin immunoprecipitation assays showed that PRE-bound p53 interacts with the corepressor-histone deacetylase 3 (HDAC3), resulting in deacetylation of histones Ac-H4, at the proximal promoter, resulting in transcriptional silencing of SVCT2. Overall, our data suggests that p53 is a potent transcriptional repressor of SVCT2, a critical transporter of diet-derived ascorbic acid, across the plasma membranes of numerous essential tissue cell types.


Assuntos
Antioxidantes/metabolismo , Histona Desacetilases/genética , Transportadores de Sódio Acoplados à Vitamina C/genética , Proteína Supressora de Tumor p53/genética , Animais , Ácido Ascórbico/genética , Ácido Ascórbico/metabolismo , Sítios de Ligação/genética , Cromatina/genética , Fibroblastos , Células Hep G2 , Humanos , Camundongos , Ligação Proteica , Proteínas Repressoras/genética , Transportadores de Sódio Acoplados à Vitamina C/antagonistas & inibidores
3.
Int J Mol Sci ; 20(9)2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035653

RESUMO

Endogenous cannabinoids (ECs) are lipid-signaling molecules that specifically bind to cannabinoid receptor types 1 and 2 (CB1R and CB2R) and are highly expressed in central and many peripheral tissues under pathological conditions. Activation of hepatic CB1R is associated with obesity, insulin resistance, and impaired metabolic function, owing to increased energy intake and storage, impaired glucose and lipid metabolism, and enhanced oxidative stress and inflammatory responses. Additionally, blocking peripheral CB1R improves insulin sensitivity and glucose metabolism and also reduces hepatic steatosis and body weight in obese mice. Thus, targeting EC receptors, especially CB1R, may provide a potential therapeutic strategy against obesity and insulin resistance. There are many CB1R antagonists, including inverse agonists and natural compounds that target CB1R and can reduce body weight, adiposity, and hepatic steatosis, and those that improve insulin sensitivity and reverse leptin resistance. Recently, the use of CB1R antagonists was suspended due to adverse central effects, and this caused a major setback in the development of CB1R antagonists. Recent studies, however, have focused on development of antagonists lacking adverse effects. In this review, we detail the important role of CB1R in hepatic insulin resistance and the possible underlying mechanisms, and the therapeutic potential of CB1R targeting is also discussed.


Assuntos
Resistência à Insulina , Receptor CB1 de Canabinoide/metabolismo , Animais , Suscetibilidade a Doenças , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Metabolismo dos Lipídeos , Terapia de Alvo Molecular , Músculo Esquelético/metabolismo , Obesidade/etiologia , Obesidade/metabolismo , Especificidade de Órgãos , Transdução de Sinais
4.
Appl Environ Microbiol ; 82(1): 2-10, 2016 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-26162872

RESUMO

Low-pressure mercury UV (LP-UV) lamps have long been used for bacterial inactivation, but due to certain disadvantages, such as the possibility of mercury leakage, deep-UV-C light-emitting diodes (DUV-LEDs) for disinfection have recently been of great interest as an alternative. Therefore, in this study, we examined the basic spectral properties of DUV-LEDs and the effects of UV-C irradiation for inactivating foodborne pathogens, including Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, and Listeria monocytogenes, on solid media, as well as in water. As the temperature increased, DUV-LED light intensity decreased slightly, whereas LP-UV lamps showed increasing intensity until they reached a peak at around 30°C. As the irradiation dosage and temperature increased, E. coli O157:H7 and S. Typhimurium experienced 5- to 6-log-unit reductions. L. monocytogenes was reduced by over 5 log units at a dose of 1.67 mJ/cm(2). At 90% relative humidity (RH), only E. coli O157:H7 experienced inactivation significantly greater than at 30 and 60% RH. In a water treatment study involving a continuous system, 6.38-, 5.81-, and 3.47-log-unit reductions were achieved in E. coli O157:H7, S. Typhimurium, and L. monocytogenes, respectively, at 0.5 liter per minute (LPM) and 200 mW output power. The results of this study suggest that the use of DUV-LEDs may compensate for the drawbacks of using LP-UV lamps to inactivate foodborne pathogens.


Assuntos
Escherichia coli O157/efeitos da radiação , Irradiação de Alimentos/métodos , Listeria monocytogenes/efeitos da radiação , Salmonella typhimurium/efeitos da radiação , Escherichia coli O157/crescimento & desenvolvimento , Contaminação de Alimentos/prevenção & controle , Irradiação de Alimentos/instrumentação , Microbiologia de Alimentos , Listeria monocytogenes/crescimento & desenvolvimento , Viabilidade Microbiana/efeitos da radiação , Salmonella typhimurium/crescimento & desenvolvimento , Temperatura , Raios Ultravioleta
5.
Psychooncology ; 24(2): 197-203, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25044259

RESUMO

BACKGROUND: Communication between cancer patients and caregivers is often suboptimal. The Cancer Communication Assessment Tool for Patient and Families (CCAT-PF) is a unique tool developed to measure congruence in patient-family caregiver communication employing a dyadic approach. We aimed to examine the cross-cultural applicability of the CCAT in the Korean healthcare setting. METHODS: Linguistic validation of the CCAT-PF was performed through a standard forward-backward translation process. Psychometric validation was performed with 990 patient-caregiver dyads recruited from 10 cancer centers. RESULTS: Mean scores of CCAT-P and CCAT-F were similar at 44.8 for both scales. Mean CCAT-PF score was 23.7 (8.66). Concordance of each items between patients and caregivers was low (weighted kappa values <0.20 for all items and Spearman's rho <0.18 for scale scores). Scale scores did not differ significantly across a variety of cancer types and stages. The CCAT-P or CCAT-F score was weakly associated with mental health and quality of life outcomes. The CCAT-PF was correlated weakly with both patient-perceived and caregiver-perceived family avoidance of cancer care scales. CONCLUSION: The CCAT-PF Korean version showed similar psychometric properties to the original English version in the assessment of communication congruence between cancer patient and family caregivers.


Assuntos
Cuidadores/psicologia , Comunicação , Cultura , Neoplasias/enfermagem , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/psicologia , Psicometria , Qualidade de Vida , República da Coreia , Inquéritos e Questionários , Traduções
6.
ACS Nano ; 18(20): 12771-12780, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38708928

RESUMO

Three-dimensional (3D) plasmonic metamaterials, featuring well-arranged subwavelength nanostructures, facilitate effective coupling between electrical dipoles and incident electromagnetic waves. This coupling allows for unique optical responses including localized surface plasmon resonance (LSPR) and quasi-bound states in the continuum (q-BIC). While 3D plasmonic metamaterials with LSPR and q-BIC have been independently explored for sensors, achieving simultaneous optical responses in the near-infrared region remains challenging. Here, we present 3D plasmonic metamaterials that integrate LSPR and q-BIC within a single π-shaped plasmonic structure, fabricated using a 3D aerosol nanoprinting technique. This printing technique controls the local electrostatic field to precisely position charged metallic nanoaerosols, enabling parallel printing of π-shaped plasmonic structures under ambient conditions. The printed π-shaped plasmonic structures exhibit two distinct optical modes: x-polarization-sensitive LSPR and transverse magnetic mode-sensitive q-BIC within the near-infrared region. Exploiting these dual optical responses, we demonstrate simultaneous polarization detection and incident angle analysis by integrating the π-shaped plasmonic structures into commercial Fourier-transform infrared spectroscopy, termed "numerical aperture-detective polarimetry". This approach holds promise for evaluating alignment in optical and imaging systems with light distribution analysis. Furthermore, the 3D aerosol nanoprinting technique provides an avenue for fabricating 3D plasmonic metamaterials with intricate geometries and optical properties, expanding their potential applications in nano-optics.

7.
ACS Appl Mater Interfaces ; 14(42): 48311-48320, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36253341

RESUMO

Friction is important in material design for robotic systems that need to perform tasks regardless of environmental changes. Generally, robotic systems lose their friction in wet environments and fail to accomplish their tasks. Despite the significance of maintaining friction in dry and wet environments, it is still challenging. Here, we report a smart switching surface, which helps to complete missions in both wet and dry environments. Inspired by the reversible wrinkling mechanism of a human finger, the surface reversibly generates and removes wrinkles to adapt to both environments using volume-changing characteristics of the Nafion film. The switchable surfaces with manipulated wrinkle morphologies via patterns of diverse densities, sizes, and shapes induce a relationship between the wrinkle morphologies and friction: wrinkles on denser and smaller hexagonal patterns generate six times more friction than non-switching flat surfaces in wet environments and a similar amount of friction to the flat surfaces in dry environments. In addition, the wrinkle morphologies according to the patterns are predicted through numerical simulation, which is in good agreement with experimental results. This work presents potential applications in robotic systems that are required to perform in and out of water and paves the way for further understanding of wrinkling dynamics, manipulation, and evolutionary function in skin.

8.
J Cancer ; 12(18): 5385-5393, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34405001

RESUMO

The sodium-dependent vitamin C transporter 2 (SVCT2) surface glycoprotein regulates ascorbate accumulation in the plasma, often resulting in the induction of cancer cell death. Therefore, high expression of this gene associates with increased overall survival in several cancers. However, in colorectal cancer (CRC), high (likely mutated) SVCT2 expression relates to poor overall survival, and its functional significance has not been studied. Thus, we hypothesize that mutant SVCT2 expression could affect CRC patient survival. According to biological databases, SVCT2 has been found to be mutated frequently, and SVCT2 E264K has a particularly high pathogenic score (0.98), compared to other SVCT2 mutant sites, in CRC patients. Interestingly, our results reveal expression of SVCT2 E264K in many CRC tissues and cells. Also, we found wild-type SVCT2 expression to be largely localized to the cytoplasm and membrane, while SVCT2 E264K was restricted to the cytoplasm. We further found that SVCT2 E264K overexpression increases cell growth. By contrast, SVCT2 E264K knockdown significantly reduced cell proliferation and promoted cell apoptosis, resulting in inhibition of cell invasion and migration. Taken together, SVCT2 E264K plays a critical role in proliferation in CRC. Our results suggest that SVCT2 E264K could be a promising novel therapeutic target in CRC.

9.
Cancer Res Treat ; 48(1): 384-92, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25779366

RESUMO

PURPOSE: This study aimed to examine the following questions: to what extent do patients and caregivers perceive their family members to be avoidant of communication regarding patient's cancer, and to what extent do these perceptions interrelate; and how do such perceptions influence their own and each other's communication behaviors, communication outcome, mental health, and quality of life. MATERIALS AND METHODS: A national survey was performed with 990 patient-caregiver dyads (participation rate, 76.2%). To examine the dyadic interaction, we developed linked patient and family member questionnaires, including the Family Avoidance of Communication about Cancer (FACC) scale. RESULTS: The mean scores (standard deviations) of patient- and caregiver-perceived FACC were low at 10.9 (15.5) and 15.5 (17.5), respectively (p < 0.001), and concordance was low, a well (Spearman's rho, 0.23). Patient-perceived FACC was associated with lower levels of disclosure and behaviors of holding back communication, as well as lower levels of mental health outcome and quality of life. The same was true for caregivers (all p < 0.05). Patient-perceived FACC was associated with caregiver holding back, caregiver's depression level, and caregiver quality of life (all p < 0.05). Both patient- and caregiver-perceived FACC were independently associated with communication difficulty within the family. CONCLUSION: Future research would benefit from the measurement of FACC from both patients and caregivers, and promote family intervention to enhance openness to communication, which would be helpful for improving mental health and quality of life for both patients and caregivers.


Assuntos
Comunicação , Família/psicologia , Neoplasias/psicologia , Inquéritos e Questionários , Cuidadores/psicologia , Escolaridade , Saúde da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida
10.
PLoS One ; 9(2): e88617, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24520403

RESUMO

Radix Polygalae (the root of Polygala tenuifolia) is a herb widely used in traditional Asian medicine that is thought to exert a variety of neuropsychiatric effects. Radix Polygalae extract can protect against N-methyl D-aspartate (NMDA) neurotoxicity and induce brain-derived neurotrophic factor (BDNF) expression, suggesting modulatory roles at glutamatergic synapses and possible antidepressant action. In accordance with this hypothesis, Radix Polygalae extract demonstrated antidepressant-like effects in 8-week-old male C57Bl/6 mice by decreasing behavioral despair in the forced swim and tail suspension tasks and increasing hedonic-like behavior in the female urine sniffing test 30 minutes after a single oral administration of 0.1 mg/kg. Reduced latency to acquire a food pellet in the novely suppressed feeding paradigm, without change in anxiety-like behaviors suggested a rapid-onset nature of the antidepressant-like effect. In addition, it decreased the number of failed escapes in the learned helplessness paradigm after two oral administrations 24 hours and 30 minutes before the first test. Finally, it reversed anhedonia as measured by saccharin preference in mice exposed to the chronic stress model after two administrations of 0.1 mg/kg, in contrast to the repeated administration generally needed for similar effect by monoamergic antidepressants. Immobility reduction in tail suspension task was blocked by the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist NBQX, a pattern previously demonstrated by ketamine and other ketamine-like rapid-onset antidepressants. Also similarly to ketamine, Radix Polygalae appeared to acutely decrease phosphorylation of GluR1 serine-845 in the hippocampus while leaving the phosphorylation of hippocampal mTOR serine 2448 unchanged. These findings serve as preclinical evidence that Radix Polygalae extract exerts rapid-onset antidepressant effects by modulating glutamatergic synapses in critical brain circuits of depression and may be worthy of further evaluation as a safe substitute to other rapid-onset antidepressants known to have unacceptable side effects.


Assuntos
Antidepressivos/uso terapêutico , Depressão/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Extratos Vegetais/uso terapêutico , Animais , Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Doença Crônica , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Medicamentos de Ervas Chinesas/farmacologia , Feminino , Glutamatos/metabolismo , Hipocampo/efeitos dos fármacos , Hipocampo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Fosforilação/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Subunidades Proteicas/metabolismo , Receptores de AMPA/metabolismo , Estresse Psicológico/tratamento farmacológico , Sinapses/efeitos dos fármacos , Sinapses/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA