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1.
J Am Chem Soc ; 146(28): 19337-19349, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38953459

RESUMO

Direct air capture (DAC) shows considerable promise for the effective removal of CO2; however, materials applicable to DAC are lacking. Among metal-organic framework (MOF) adsorbents, diamine-Mg2(dobpdc) (dobpdc4- = 4,4-dioxidobiphenyl-3,3'-dicarboxylate) effectively removes low-pressure CO2, but the synthesis of the organic ligand requires high temperature, high pressure, and a toxic solvent. Besides, it is necessary to isolate the ligand for utilization in the synthesis of the framework. In this study, we synthesized a new variant of extended MOF-74-type frameworks, M2(hob) (M = Mg2+, Co2+, Ni2+, and Zn2+; hob4- = 5,5'-(hydrazine-1,2-diylidenebis(methanylylidene))bis(2-oxidobenzoate)), constructed from an azine-bonded organic ligand obtained through a facile condensation reaction at room temperature. Functionalization of Mg2(hob) with N-methylethylenediamine, N-ethylethylenediamine, and N,N'-dimethylethylenediamine (mmen) enables strong interactions with low-pressure CO2, resulting in top-tier adsorption capacities of 2.60, 2.49, and 2.91 mmol g-1 at 400 ppm of CO2, respectively. Under humid conditions, the CO2 capacity was higher than under dry conditions due to the presence of water molecules that aid in the formation of bicarbonate species. A composite material combining mmen-Mg2(hob) and polyvinylidene fluoride, a hydrophobic polymer, retained its excellent adsorption performance even after 7 days of exposure to 40% relative humidity. In addition, the one-pot synthesis of Mg2(hob) from a mixture of the corresponding monomers is achieved without separate ligand synthesis steps; thus, this framework is suitable for facile large-scale production. This work underscores that the newly synthesized Mg2(hob) and its composites demonstrate significant potential for DAC applications.

2.
Mol Cell ; 62(1): 7-20, 2016 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-27052731

RESUMO

The Src-homology 2 (SH2) domain is a protein interaction domain that directs myriad phosphotyrosine (pY)-signaling pathways. Genome-wide screening of human SH2 domains reveals that ∼90% of SH2 domains bind plasma membrane lipids and many have high phosphoinositide specificity. They bind lipids using surface cationic patches separate from pY-binding pockets, thus binding lipids and the pY motif independently. The patches form grooves for specific lipid headgroup recognition or flat surfaces for non-specific membrane binding and both types of interaction are important for cellular function and regulation of SH2 domain-containing proteins. Cellular studies with ZAP70 showed that multiple lipids bind its C-terminal SH2 domain in a spatiotemporally specific manner and thereby exert exquisite spatiotemporal control over its protein binding and signaling activities in T cells. Collectively, this study reveals how lipids control SH2 domain-mediated cellular protein-protein interaction networks and suggest a new strategy for therapeutic modulation of pY-signaling pathways.


Assuntos
Metabolismo dos Lipídeos , Linfócitos T/metabolismo , Proteína-Tirosina Quinase ZAP-70/química , Proteína-Tirosina Quinase ZAP-70/metabolismo , Domínios de Homologia de src , Sítios de Ligação , Células Cultivadas , Humanos , Células Jurkat , Modelos Moleculares , Simulação de Acoplamento Molecular , Fosfotirosina/efeitos dos fármacos , Fosfotirosina/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Transdução de Sinais
3.
Small ; 19(47): e2303263, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37434049

RESUMO

A cobalt phthalocyanine having an electron-poor CoN4 (+δ) in its phthalocyanine moiety was presented as an electrocatalyst for hydrogen peroxide oxidation reaction (HPOR). We suggested that hydrogen peroxide as an electrolysis medium for hydrogen production and therefore as a hydrogen carrier, demonstrating that the electrocatalyst guaranteed high hydrogen production rate by hydrogen peroxide splitting. The electron deficiency of cobalt allows CoN4 to have the highly HPOR-active monovalent oxidation state and facilitates HPOR at small overpotentials range around the onset potential. The strong interaction between the electron-deficient cobalt and oxygen of peroxide adsorbates in Co─OOH- encourages an axially coordinated cobalt oxo complex (O═CoN4 ) to form, the O═CoN4 facilitating the HPOR efficiently at high overpotentials. Low-voltage oxygen evolution reaction guaranteeing low-voltage hydrogen production is successfully demonstrated in the presence of the metal-oxo complex having electron-deficient CoN4 . Hydrogen production by 391 mA cm-2 at 1 V and 870 mA cm-2 at 1.5 V is obtained. Also, the techno-economic benefit of hydrogen peroxide as a hydrogen carrier is evaluated by comparing hydrogen peroxide with other hydrogen carriers such as ammonia and liquid organic hydrogen carriers.

4.
Small ; 19(28): e2300526, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37010008

RESUMO

Polymer-based nanocomposites are desirable materials for next-generation dielectric capacitors. 2D dielectric nanosheets have received significant attention as a filler. However, randomly spreading the 2D filler causes residual stresses and agglomerated defect sites in the polymer matrix, which leads to the growth of an electric tree, resulting in a more premature breakdown than expected. Therefore, realizing a well-aligned 2D nanosheet layer with a small amount is a key challenge; it can inhibit the growth of conduction paths without degrading the performance of the material. Here, an ultrathin Sr1.8 Bi0.2 Nb3 O10 (SBNO) nanosheet filler is added as a layer into poly(vinylidene fluoride) (PVDF) films via the Langmuir-Blodgett method. The structural properties, breakdown strength, and energy storage capacity of a PVDF and multilayer PVDF/SBNO/PVDF composites as a function of the thickness-controlled SBNO layer are examined. The seven-layered (only 14 nm) SBNO nanosheets thin film can sufficiently prevent the electrical path in the PVDF/SBNO/PVDF composite and shows a high energy density of 12.8 J cm-3 at 508 MV m-1 , which is significantly higher than that of the bare PVDF film (9.2 J cm-3 at 439 MV m-1 ). At present, this composite has the highest energy density among the polymer-based nanocomposites under the filler of thin thickness.

5.
Sensors (Basel) ; 21(24)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34960539

RESUMO

Modern data augmentation strategies such as Cutout, Mixup, and CutMix, have achieved good performance in image recognition tasks. Particularly, the data augmentation approaches, such as Mixup and CutMix, that mix two images to generate a mixed training image, could generalize convolutional neural networks better than single image-based data augmentation approaches such as Cutout. We focus on the fact that the mixed image can improve generalization ability, and we wondered if it would be effective to apply it to a single image. Consequently, we propose a new data augmentation method to produce a self-mixed image based on a saliency map, called SalfMix. Furthermore, we combined SalfMix with state-of-the-art two images-based approaches, such as Mixup, SaliencyMix, and CutMix, to increase the performance, called HybridMix. The proposed SalfMix achieved better accuracies than Cutout, and HybridMix achieved state-of-the-art performance on three classification datasets: CIFAR-10, CIFAR-100, and TinyImageNet-200. Furthermore, HybridMix achieved the best accuracy in object detection tasks on the VOC dataset, in terms of mean average precision.


Assuntos
Redes Neurais de Computação
6.
Nano Lett ; 19(6): 3627-3633, 2019 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-31071266

RESUMO

Developing easy and customizable strategies for the directional structure modulation of multicomponent nanosystems to influence and optimize their properties are a paramount but challenging task in nanoscience. Here, we demonstrate highly controlled eccentric off-center positioning of metal-core in metal@silica core-shells by utilizing an in situ generated biphasic silica-based intraparticle solid-solid interface. In the synthetic strategy, by including Ca2+-ions in silica-shell and successive oxidative and reductive annealing at high temperature, a unique hairline-biphasic interface is evolved via the heat-induced concentric radial segregation of calcium silicate phase at the interior and normal silica phase at the exterior of core-shell, which can effectively arrest the outwardly migrating metal-core within rubbery calcium silicate phase, affording various eccentric core-shells, where core-positions are flexibly controlled by the annealing time and amounts of initially added Ca2+-ions. In the structure-property correlation study, the strategy allows fine-tuning of dipolar interaction-based blocking temperatures and magnetic anisotropies of different eccentric core-shells as the function of variable off-center distance of magnetic core without changing the overall size of nanoparticles. This work demonstrates the discovery and potential application of biphasic solid-solid media interface in controlling the heat-induced migration of metal nanocrystals and opens the avenues for exploiting the rarely studied high-temperature solid-state nanocrystal conversion chemistry and migratory behavior for directional nanostructure engineering.

7.
J Am Chem Soc ; 138(22): 7075-81, 2016 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-27175474

RESUMO

Polymerase chain reaction (PCR) is a highly sensitive diagnosis technique for detection of nucleic acids and for monitoring residual disease; however, PCR can be unreliable for samples containing very few target molecules. Here, we describe a quantification method, using force-distance (FD) curve based atomic force microscopy (AFM) to detect a target DNA bound to small (1.4-1.9 µm diameter) probe DNA spots, allowing mapping of entire spots to nanometer resolution. Using a synthetic BCR-ABL fusion gene sequence target, we examined samples containing between one and 10 target copies. A high degree of correlation (r(2) = 0.994) between numbers of target copies and detected probe clusters was observed, and the approach could detect the BCR-ABL biomarker when only a single copy was present, although multiple screens were required. Our results clearly demonstrate that FD curve-based imaging is suitable for quantitative analysis of fewer than 10 copies of DNA biomarkers without amplification, modification, or labeling.


Assuntos
DNA/genética , Proteínas de Fusão bcr-abl/genética , Microscopia de Força Atômica/métodos , Reação em Cadeia da Polimerase/métodos , Biomarcadores/análise , Sondas de DNA , Limite de Detecção
8.
Small ; 12(11): 1446-57, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26800021

RESUMO

Effective insertion of vertically aligned nanowires (NWs) into cells is critical for bioelectrical and biochemical devices, biological delivery systems, and photosynthetic bioenergy harvesting. However, accurate insertion of NWs into living cells using scalable processes has not yet been achieved. Here, NWs are inserted into living Chlamydomonas reinhardtii cells (Chlamy cells) via inkjet printing of the Chlamy cells, representing a low-cost and large-scale method for inserting NWs into living cells. Jetting conditions and printable bioink composed of living Chlamy cells are optimized to achieve stable jetting and precise ink deposition of bioink for indentation of NWs into Chlamy cells. Fluorescence confocal microscopy is used to verify the viability of Chlamy cells after inkjet printing. Simple mechanical considerations of the cell membrane and droplet kinetics are developed to control the jetting force to allow penetration of the NWs into cells. The results suggest that inkjet printing is an effective, controllable tool for stable insertion of NWs into cells with economic and scale-related advantages.


Assuntos
Chlamydomonas/citologia , Tinta , Nanofios/química , Impressão/métodos , Sobrevivência Celular , Microscopia de Fluorescência
9.
Pain Med ; 16(6): 1077-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25105892

RESUMO

OBJECTIVES: The aims of this study were to evaluate the role of intra-articular joint injection for atlanto-occipital (AO) joint pain and to determine pain referral sites from that joint. DESIGN: Prospective observational study. METHOD: We evaluated 29 patients with chronic refractory neck pain and/or headache, and limited range of lateral bending with rotation at the AO joint on physical examination. Of the 24 patients who consented to undergo diagnostic injections, 20 patients had at least 50% relief from pain and underwent two AO intra-articular injections of mixture of local anesthetic and steroid approximately 1 week apart. Patients completed pain drawings, visual analog scales (VASs) for pain, and neck disability index (NDI) for level of function. Patients were evaluated for 2 months after the first injection. RESULT: There was headache in 14/20 (70%), posterior neck pain (PNP) in 20, and referred pain in 17 (85%). The average VAS values for headache, PNP, and other referred pains were reduced significantly from 5.64, 5.70, and 5.41, respectively, before treatments to 0.64, 2.30, and 1.71, respectively, two months after injection (P < 0.01). The average NDI value was reduced significantly from 39.95% at pretreatment to 20.40% at 2 months after treatment (P < 0.01). CONCLUSION: AO intra-articular steroid injection appears effective for the short-term control of chronic refractory pain arising from the AO joint.


Assuntos
Artralgia/tratamento farmacológico , Articulação Atlantoccipital/efeitos dos fármacos , Medição da Dor/efeitos dos fármacos , Triancinolona/administração & dosagem , Adulto , Idoso , Artralgia/diagnóstico por imagem , Articulação Atlantoccipital/diagnóstico por imagem , Feminino , Seguimentos , Glucocorticoides/administração & dosagem , Humanos , Injeções Intra-Articulares , Masculino , Pessoa de Meia-Idade , Medição da Dor/métodos , Estudos Prospectivos , Radiografia , Resultado do Tratamento
10.
Angew Chem Int Ed Engl ; 54(52): 15730-3, 2015 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-26568300

RESUMO

The electric conductivity-dependence of the number of electrons transferred during the oxygen reduction reaction is presented. Intensive properties, such as the number of electrons transferred, are difficult to be considered conductivity-dependent. Four different perovskite oxide catalysts of different conductivities were investigated with varying carbon contents. More conductive environments surrounding active sites, achieved by more conductive catalysts (providing internal electric pathways) or higher carbon content (providing external electric pathways), resulted in higher number of electrons transferred toward more complete 4e reduction of oxygen, and also changed the rate-determining steps from two-step 2e process to a single-step 1e process. Experimental evidence of the conductivity dependency was described by a microscopic ohmic polarization model based on effective potential localized nearby the active sites.

11.
Sci Rep ; 14(1): 7661, 2024 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561420

RESUMO

Complex temporal bone anatomy complicates operations; thus, surgeons must engage in practice to mitigate risks, improving patient safety and outcomes. However, existing training methods often involve prohibitive costs and ethical problems. Therefore, we developed an educational mastoidectomy simulator, considering mechanical properties using 3D printing. The mastoidectomy simulator was modeled on computed tomography images of a patient undergoing a mastoidectomy. Infill was modeled for each anatomical part to provide a realistic drilling sensation. Bone and other anatomies appear in assorted colors to enhance the simulator's educational utility. The mechanical properties of the simulator were evaluated by measuring the screw insertion torque for infill specimens and cadaveric temporal bones and investigating its usability with a five-point Likert-scale questionnaire completed by five otolaryngologists. The maximum insertion torque values of the sigmoid sinus, tegmen, and semicircular canal were 1.08 ± 0.62, 0.44 ± 0.42, and 1.54 ± 0.43 N mm, displaying similar-strength infill specimens of 40%, 30%, and 50%. Otolaryngologists evaluated the quality and usability at 4.25 ± 0.81 and 4.53 ± 0.62. The mastoidectomy simulator could provide realistic bone drilling feedback for educational mastoidectomy training while reinforcing skills and comprehension of anatomical structures.


Assuntos
Mastoidectomia , Treinamento por Simulação , Humanos , Impressão Tridimensional , Osso Temporal/cirurgia , Treinamento por Simulação/métodos
12.
Adv Sci (Weinh) ; 11(17): e2306630, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38493494

RESUMO

The modification of synaptic and neural connections in adults, including the formation and removal of synapses, depends on activity-dependent synaptic and structural plasticity. MicroRNAs (miRNAs) play crucial roles in regulating these changes by targeting specific genes and regulating their expression. The fact that somatic and dendritic activity in neurons often occurs asynchronously highlights the need for spatial and dynamic regulation of protein synthesis in specific milieu and cellular loci. MicroRNAs, which can show distinct patterns of enrichment, help to establish the localized distribution of plasticity-related proteins. The recent study using atomic force microscopy (AFM)-based nanoscale imaging reveals that the abundance of miRNA(miR)-134 is inversely correlated with the functional activity of dendritic spine structures. However, the miRNAs that are selectively upregulated in potentiated synapses, and which can thereby support prospective changes in synaptic efficacy, remain largely unknown. Using AFM force imaging, significant increases in miR-132 in the dendritic regions abutting functionally-active spines is discovered. This study provides evidence for miR-132 as a novel positive miRNA regulator residing in dendritic shafts, and also suggests that activity-dependent miRNAs localized in distinct sub-compartments of neurons play bi-directional roles in controlling synaptic transmission and synaptic plasticity.


Assuntos
MicroRNAs , Microscopia de Força Atômica , Plasticidade Neuronal , Sinapses , Animais , Camundongos , Espinhas Dendríticas/metabolismo , Espinhas Dendríticas/genética , Espinhas Dendríticas/ultraestrutura , Camundongos Endogâmicos C57BL , MicroRNAs/genética , MicroRNAs/metabolismo , Microscopia de Força Atômica/métodos , Plasticidade Neuronal/genética , Plasticidade Neuronal/fisiologia , Neurônios/metabolismo , Sinapses/metabolismo , Sinapses/genética
13.
JACS Au ; 4(3): 1031-1038, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38559726

RESUMO

With the advancement of semiconductor manufacturing technology, the effects of trace impurities in industrial chemicals have grown significantly. In industrial processes, conventional purification methods, such as filtration and distillation, have reached their limits for removing nanoparticles from aqueous and acidic solutions. Especially, silicon and silicate are two fundamental byproducts in semiconductor fabrication processes. Assembly and subsequent removal of these materials at the nanoparticle level have been confronted with significant challenges. Therefore, it is imperative to develop technologies to effectively control and remove these impurities for next-generation manufacturing processes. In this study, we explored the use of electric field-assisted assembly to agglomerate silicate and silicon nanoparticles in industry-standard aqueous and acidic solutions. By applying an alternating current electric field, we induced dipole moments in the nanoparticles, which led to their agglomeration. Notably, nanoparticles smaller than 4 nm grew into significantly larger ones, with submicroparticle sizes exceeding 87 nm for silicate and reaching 130 nm for silicon. Through systematic analysis of the size distribution changes, we identified optimal agglomeration times of 10 min for silicate and 20 min for silicon, revealing effective agglomeration within the frequency range of 1-1000 kHz. The agglomerated particles were stable for 5 days. Our electric field-assisted approach to obtain assembled nanoparticles that can be subsequently removed by conventional purification processes holds promise for enhancing future microfabrication processes, such as semiconductor manufacturing, potentially improving the manufacturing yield and uniformity by reducing the number of trace particles that can act as defective sites.

14.
Adv Sci (Weinh) ; 11(31): e2401494, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38889336

RESUMO

Wireless energy transfer (WET) based on ultrasound-driven generators with enormous beneficial functions, is technologically in progress by the valuation of ultrasonic metamaterials (UMMs) in science and engineering domains. Indeed, novel metamaterial structures can develop the efficiency of mechanical and physical features of ultrasound energy receivers (US-ETs), including ultrasound-driven piezoelectric and triboelectric nanogenerators (US-PENGs and US-TENGs) for advantageous applications. This review article first summarizes the fundamentals, classification, and design engineering of UMMs after introducing ultrasound energy for WET technology. In addition to addressing using UMMs, the topical progress of innovative UMMs in US-ETs is conceptually presented. Moreover, the advanced approaches of metamaterials are reported in the categorized applications of US-PENGs and US-TENGs. Finally, some current perspectives and encounters of UMMs in US-ETs are offered. With this objective in mind, this review explores the potential revolution of reliable integrated energy transfer systems through the transformation of metamaterials into ultrasound-driven active mediums for generators.

15.
Adv Mater ; 36(32): e2402491, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38837481

RESUMO

Self-powered electrical bandages (SEBs), integrated with wearable energy harvesters, can provide an effective and autonomous electrical stimulation (ES) solution for rapid and scarless wound healing. A continuously operating, wireless, and applicable-to-comprehensive-wound ES device is essential for the quick restoration of wounds and convenience. This work illustrates a SEB powered by body-coupled energy harvesting. The SEB continuously treats the wound with 60-Hz sinusoidal electrical potential gained from the coupling of the human body and ambient electrical waves. It is demonstrated that enough level of electrical potential can be applied to the wound, further enhanced by strong capacitive coupling arising from the use of high-permittivity poly(vinylidene fluoride-trifluoroethylene):CaCu3Ti4O12 (P(VDF-TrFE):CCTO) nanocomposite. The potential clinical efficacy of the SEB is illustrated by preclinical analysis of human fibroblasts and mouse wound model, thus confirming the successful expedition of wound recovery. This work suggests a new class of wearable devices to provide ES events and its potential for extension to other conventional wound care materials and device technology.


Assuntos
Bandagens , Dispositivos Eletrônicos Vestíveis , Cicatrização , Humanos , Animais , Camundongos , Polivinil/química , Nanocompostos/química , Fibroblastos/citologia , Estimulação Elétrica , Fontes de Energia Elétrica
16.
Proteomics ; 13(7): 1164-79, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23349036

RESUMO

Type 2 diabetes mellitus (T2DM) is the most prevalent and serious metabolic disease affecting people worldwide. T2DM results from insulin resistance of the liver, muscle, and adipose tissue. In this study, we used proteomic and bioinformatic methodologies to identify novel hepatic membrane proteins that are related to the development of hepatic insulin resistance, steatosis, and T2DM. Using FT-ICR MS, we identified 95 significantly differentially expressed proteins in the membrane fraction of normal and T2DM db/db mouse liver. These proteins are primarily involved in energy metabolism pathways, molecular transport, and cellular signaling, and many of them have not previously been reported in diabetic studies. Bioinformatic analysis revealed that 16 proteins may be related to the regulation of insulin signaling in the liver. In addition, six proteins are associated with energy stress-induced, nine proteins with inflammatory stress-induced, and 14 proteins with endoplasmic reticulum stress-induced hepatic insulin resistance. Moreover, we identified 19 proteins that may regulate hepatic insulin resistance in a c-Jun amino-terminal kinase-dependent manner. In addition, three proteins, 14-3-3 protein beta (YWHAB), Slc2a4 (GLUT4), and Dlg4 (PSD-95), are discovered by comprehensive bioinformatic analysis, which have correlations with several proteins identified by proteomics approach. The newly identified proteins in T2DM should provide additional insight into the development and pathophysiology of hepatic steatosis and insulin resistance, and they may serve as useful diagnostic markers and/or therapeutic targets for these diseases.


Assuntos
Biologia Computacional/métodos , Diabetes Mellitus Tipo 2/metabolismo , Fígado/metabolismo , Proteínas de Membrana/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Animais , Estresse do Retículo Endoplasmático , Inflamação/metabolismo , Resistência à Insulina , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Metabolismo dos Lipídeos , Masculino , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Mapas de Interação de Proteínas , Reprodutibilidade dos Testes
17.
ACS Appl Mater Interfaces ; 15(31): 37687-37695, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37498125

RESUMO

Appropriate gate dielectrics must be identified to fabricate metal-insulator-semiconductor field-effect transistors (MISFETs); however, this has been challenging for compound semiconductors owing to the absence of high-quality native oxides. This study uses the liquid-gallium squeezing technique to fabricate 2D amorphous gallium oxide (GaOX) with a high dielectric constant, where its thickness is precisely controlled at the atomic scale (monolayer, ∼4.5 nm; bilayer, ∼8.5 nm). Beta-phase gallium oxide (ß-Ga2O3) with an ultrawide energy bandgap (4.5-4.9 eV) has emerged as a next-generation power semiconductor material and is presented here as the channel material. The 2D amorphous GaOX dielectric is combined with a ß-Ga2O3 conducting nanolayer, and the resulting ß-Ga2O3 MISFET is stable up to 250 °C. The 2D amorphous GaOX is oxygen-deficient, and a high-quality interface with excellent uniformity and scalability forms between the 2D amorphous GaOX and ß-Ga2O3. The fabricated MISFET exhibits a wide gate-voltage swing of approximately +5 V, a high current on/off ratio, moderate field-effect carrier mobility, and a decent three-terminal breakdown voltage (∼138 V). The carrier transport of the Ni/GaOX/ß-Ga2O3 metal-insulator-semiconductor (MIS) structure displays a combination of Schottky emission and Fowler-Nordheim (F-N) tunneling in the high-gate-bias region at 25 °C, whereas at elevated temperatures it shows Schottky emission and F-N tunneling in the low- and high-gate-bias regions, respectively. This study demonstrates that a 2D GaOX gate dielectric layer can be produced and incorporated into an active channel layer to form an MIS structure at room temperature (∼25 °C), which enables the facile fabrication of MISFET devices.

18.
Adv Sci (Weinh) ; 10(3): e2205179, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36442861

RESUMO

An innovative autonomous resonance-tuning (ART) energy harvester is reported that utilizes adaptive clamping systems driven by intrinsic mechanical mechanisms without outsourcing additional energy. The adaptive clamping system modulates the natural frequency of the harvester's main beam (MB) by adjusting the clamping position of the MB. The pulling force induced by the resonance vibration of the tuning beam (TB) provides the driving force for operating the adaptive clamp. The ART mechanism is possible by matching the natural frequencies of the TB and clamped MB. Detailed evaluations are conducted on the optimization of the adaptive clamp tolerance and TB design to increase the pulling force. The energy harvester exhibits an ultrawide resonance bandwidth of over 30 Hz in the commonly accessible low vibration frequency range (<100 Hz) owing to the ART function. The practical feasibility is demonstrated by evaluating the ART performance under both frequency and acceleration-variant conditions and powering a location tracking sensor.

19.
Pain Med ; 13(3): 368-75, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22296730

RESUMO

OBJECTIVE: The article aims to evaluate the long-term effectiveness and safety of pulsed radiofrequency (PRF) on the dorsal root ganglion (DRG) in patients with chronic cervical radicular pain refractory to repeated transforaminal epidural steroid injections (TFESIs). DESIGN: This is a prospective observational study. METHODS: We retrospectively reviewed data on 112 subjects who had received repeated TFESIs for cervical radicular pain. Twenty-nine of those 112 patients continued to complain of persistent cervical radicular pain, despite an average of three repeated TFESIs. Among 29 patients with sustained arm pain of over 4 on the numerical rating scale (NRS), a total of 21 patients were included prospectively. Those 21 patients underwent PRF on the symptomatic cervical DRG and were evaluated carefully for neurologic deficits and side effects. The clinical outcomes were measured via NRS for arm pain before treatment, and 1, 3, 6, and 12 months after treatment. Successful pain relief was defined as a 50% or more reduction in the NRS score as compared with the pretreatment score. After 12 months, patients' satisfaction levels with treatment were determined. RESULTS: Fourteen of the 21 patients (66.7%) after cervical PRF stimulation reported pain relief of 50% or more at the 3-month and 12-month follow-up periods, respectively. Fifteen of the 21 patients (71.4%) were satisfied with their outcome at 12 months' posttreatment. No serious adverse effects were observed. CONCLUSION: Application of PRF to the DRG appears to be an effective and relatively safe intervention technique for chronic cervical radicular pain refractory to repeated TFESIs.


Assuntos
Manejo da Dor/métodos , Tratamento por Radiofrequência Pulsada/métodos , Radiculopatia/terapia , Corticosteroides/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Gânglios Espinais/fisiologia , Humanos , Injeções Epidurais , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Radiculopatia/complicações , Tempo , Resultado do Tratamento
20.
Pain Med ; 13(9): 1227-34, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22845425

RESUMO

OBJECTIVE: Pulsed radiofrequency (PRF) procedure has been used in clinical practice for the treatment of chronic neuropathic pain conditions without neuronal damage. The purpose of this study was to investigate the changes in pain response and glial expression after the application of PRF on a dorsal root ganglion (DRG) in a neuropathic pain model. DESIGN: A neuropathic pain model (14 female Sprague-Dawley [SD] rats; 200-250 g) was made by a unilateral L5 spinal nerve ligation (SNL) and transection on the distal side of the ligation. The development of mechanical and cold hypersensitivity on the hindpaw was established postoperative day 9 (POD 9). The rats were then randomly assigned to the PRF (+) and the PRF (-) groups. Furthermore, PRF (2 bursts/s, duration = 20 milliseconds, output voltage = 45 V) was applied on the ipsilateral DRG for 180 seconds, with a maximum temperature of 42°C, at POD 10. Pain behaviors were tested throughout the 12 days after PRF. We also examined the changes of the spinal glial expression by immunohistochemistry. RESULTS: Significant reduction of mechanical hypersensitivity in the PRF (+) group was observed from day 1 after a single PRF procedure and was maintained throughout the following 12 days. Immunoreactivity for OX42 in the ipsilateral dorsal horn also decreased compared with that of the PRF (-) group. However, cold hypersensitivity and glial fibrillary acidic protein (GFAP) immunoreactivity in the dorsal horn was not affected by a PRF procedure. CONCLUSIONS: Our result demonstrated that the mechanical hypersensitivity, induced by L5 SNL, was attenuated by a PRF procedure on the ipsilateral DRG. This analgesic effect may be associated with an attenuation of the microglial activation in the dorsal horn.


Assuntos
Hiperalgesia/terapia , Microglia/metabolismo , Neuralgia/terapia , Tratamento por Radiofrequência Pulsada , Animais , Modelos Animais de Doenças , Feminino , Proteína Glial Fibrilar Ácida/biossíntese , Hiperalgesia/etiologia , Hiperalgesia/metabolismo , Imuno-Histoquímica , Ligadura , Neuralgia/metabolismo , Ratos , Ratos Sprague-Dawley
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