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1.
J Mater Sci Mater Med ; 35(1): 54, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39251504

RESUMO

Both silicon (Si) and zinc (Zn) ions are essential elements to bone health and their mechanisms for promoting osteogenesis have aroused the extensive attention of researchers. Thereinto, the mechanism by which dual ions promote osteogenic differentiation remains to be elucidated. Herein, the effects of Si and Zn ions on the cytological behaviors of mBMSCs were firstly studied. Then, the molecular mechanism of Si-Zn dual ions regulating the osteogenic differentiation of mBMSCs was investigated via transcriptome sequencing technology. In the single-ion system, Si ion at the concentration of 1.5 mM (Si-1.5) had better comprehensive effects of cell proliferation, ALP activity and osteogenesis-related gene expression levels (ALP, Runx2, OCN, Col-I and BSP); Zn ion at the concentration of 50 µM (Zn-50) demonstrated better combining effects of cell proliferation, ALP activity and same osteogenic genes expression levels. In the dual-ion system, the Si (1.5 mM)-Zn (50 µM) group (Si1.5-Zn50) synthetically enhanced ALP activity and osteogenesis genes compared with single-ion groups. Analysis of the transcriptome sequencing results showed that Si ion had a certain effect on promoting the osteogenic differentiation of mBMSCs; Zn ion had a stronger effect of contributing to a better osteogenic differentiation of mBMSCs than that of Si ion; the Si-Zn dual ions had a synergistic enhancement on conducting to the osteogenic differentiation of mBMSCs compared to single ion (Si or Zn). This study offers a blueprint for exploring the regulation mechanism of osteogenic differentiation by dual ions.


Assuntos
Diferenciação Celular , Proliferação de Células , Íons , Células-Tronco Mesenquimais , Osteogênese , RNA Mensageiro , Silício , Zinco , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Silício/química , Silício/farmacologia , Diferenciação Celular/efeitos dos fármacos , Zinco/química , Zinco/farmacologia , Proliferação de Células/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Animais , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transcriptoma/efeitos dos fármacos , Células Cultivadas , Perfilação da Expressão Gênica/métodos , Análise de Sequência de RNA
2.
Aesthetic Plast Surg ; 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858243

RESUMO

INTRODUCTION: Secondary nasal deformity following unilateral cleft lip is a common facial congenital malformation. Due to its complex treatment, there is currently no unified treatment plan in clinical practice. Dysplasia of cartilage, dislocation of muscles, and dysplasia of maxilla are the main causes of secondary nasal deformities of unilateral cleft lip. This article provides a comprehensive summary of the perioperative period and treatment process of unilateral cleft lip nasal deformities, aiming to find better clinical treatment guidance for patients with unilateral cleft lip and nasal deformity. METHODS: A review of numerous previous studies on unilateral cleft lip nasal deformity, particularly within the last five years, was conducted to gather information on treatment strategies and perioperative care for unilateral cleft lip rhinoplasty. CONCLUSION: Currently, there is still no unified final surgical method for the correction and treatment of unilateral cleft lip nasal deformity. In terms of surgical timing, simultaneous primary rhinoplasty and lip repair are gradually being recognized internationally, while intermediate rhinoplasty can be considered when it affects the patients social and psychological life. Patients with severe initial nasal deformity require multiple revisions. Secondary rhinoplasty remains the ideal treatment for final correction of secondary nasal deformities in unilateral cleft lip. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

3.
Opt Express ; 31(11): 18327-18335, 2023 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-37381545

RESUMO

Ultraviolet photodetectors have aroused wide concern based on wide-band-gap semiconductors, such as GaN and Ga2O3. Exploiting multi-spectral detection provides unparalleled driving force and direction for high-precision ultraviolet detection. Here we demonstrate an optimized design strategy of Ga2O3/GaN heterostructure bi-color ultraviolet photodetector, which presents extremely high responsivity and UV-to-visible rejection ratio. The electric field distribution of optical absorption region was profitably modified by optimizing heterostructure doping concentration and thickness ratio, thus further facilitating the separation and transport of photogenerated carriers. Meanwhile, the modulation of Ga2O3/GaN heterostructure band offset leads to the fluent transport of electrons and the blocking of holes, thereby enhancing the photoconductive gain of the device. Eventually, the Ga2O3/GaN heterostructure photodetector successfully realizes dual-band ultraviolet detection and achieves high responsivity of 892/950 A/W at the wavelength of 254/365 nm, respectively. Moreover, UV-to-visible rejection ratio of the optimized device also keeps at a high level (∼103) while exhibiting dual-band characteristic. The proposed optimization scheme is anticipated to provide significant guidance for the reasonable device fabrication and design on multi-spectral detection.

4.
Opt Lett ; 48(2): 247-250, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36638429

RESUMO

The authors demonstrate the enhanced light output from 275-nm AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED) structures via the in-plane modulation of shallow photonic crystal (PC) patterns that were fabricated on the p-AlGaN contact layer surface. The employed PC lattice constants are in the range of 270-780 nm, much larger than the fundamental Bragg order lattice constant (∼95 nm). As compared to the unpatterned sample, the intensity of the top (or bottom) emission can be enhanced by up to 331% (or 246%), attributed to the high-order coherent diffraction of the internal trapped light and also the Purcell enhancement of spontaneous emission. The findings in this Letter suggest an easier way for the realization of more energy-efficient DUV LEDs which offer the advantage of high emission for various applications in disinfection and sterilization.

5.
Small ; 18(37): e2107301, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35869035

RESUMO

GaN-based lateral Schottky barrier diodes (SBDs) have attracted great attention for high-power applications due to its combined high electron mobility and large critical breakdown field. However, the breakdown voltage (BV) of the SBDs are far from exploiting the material advantages of GaN at present, limiting the desire to use GaN for ultra-high voltage (UHV) applications. Then, a golden question is whether the excellent properties of GaN-based materials can be practically used in the UHV field? Here, UHV AlGaN/GaN SBDs are demonstrated on sapphire with a BV of 10.6 kV, a specific on-resistance (RON,SP ) of 25.8 mΩ cm2 , yielding a power figure-of-merit (P-FOM = BV2 /RON,SP ) of 4.35 GW cm-2 . These devices are designed with single channel and 85-µm anode-to-cathode spacing, without other additional electric field management, demonstrating its great potential for the UHV application in power electronics.

6.
J Environ Manage ; 279: 111735, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33310236

RESUMO

Antarctica, an area that is devoted to global peace and research, is being challenged by climate change, human activities, and pollution. There have been a number of studies concerning the state of the Antarctic ecological environment. However, a comprehensive and quantitative assessment of the impact of threats on the Antarctica ecological environment is still lacking. In this study, a cumulative impact assessment performed on the basis of expert judgement was used to estimate species-specific differences on the impact of seven threats: climate change, organic and nonorganic pollutants, station construction, power generation, oil spilling, and tourism. The terrestrial area of the Fildes Peninsula was divided into 103 cells using a raster grid of 0.25 km2, and cumulative impact assessment was applied to each cell. The analysis results indicated that cumulative impact scores (IC) ranged from 0 to 39.4, and the cumulative scores were divided into six categories ranging from very low impact (IC ≤ 7.08) to very high impact (IC > 20.54). More than half of the terrestrial area (57.3%) experienced "Very Low Impact" or "Low impact" scores. For single factors, climate change was identified as a rapidly growing and significant threat facing the terrestrial ecosystems of Antarctica. In addition, tourism had the greatest impact among all human activities. The analytical process and resulting map indicate that it is necessary to develop international policies on the restriction of tourist activity space and strength the organic pollutant controls for terrestrial ecosystem protection in the Fildes Peninsula, Antarctica.


Assuntos
Ecossistema , Atividades Humanas , Regiões Antárticas , Mudança Climática , Poluição Ambiental , Humanos
7.
Opt Express ; 28(4): 5731-5740, 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32121788

RESUMO

Enhancement in the light interaction between plasmonic nanoparticles (NPs) and semiconductors is a promising way to enhance the performance of optoelectronic devices beyond the conventional limit. In this work, we demonstrated improved performance of Ga2O3 solar-blind photodetectors (PDs) by the decoration of Rh metal nanoparticles (NPs). Integrated with Rh NPs on oxidized Ga2O3 surface, the resultant device exhibits a reduced dark current of about 10 pA, an obvious enhancement in peak responsivity of 2.76 A/W at around 255 nm, relatively fast response and recovery decay times of 1.76 ms/0.80 ms and thus a high detectivity of ∼1013 Jones. Simultaneously, the photoresponsivity above 290 nm wavelength decreases significantly with improved rejection ratio between ultraviolet A (UVA) and ultraviolet B (UVB) regions, indicative of enhanced wavelength detecting selectivity. The plasmonic resonance features observed in transmittance spectra are consistent with the finite difference time-domain (FDTD) calculations. This agreement indicates that the enhanced electric field strength induced by the localized surface plasmon resonance is responsible for the enhanced absorption and photoresponsivity. The formed localized Schottky barrier at the interface of Rh/Ga2O3 will deplete the carriers at the Ga2O3 surface and lead to the remarkable reduced dark current and thus improve the detectivity. These findings provide direct evidence for Rh plasmonic enhancement in solar-blind spectral region, offering an alternative pathway for the rational design of high-performance solar-blind PDs.

8.
Nanotechnology ; 30(6): 065202, 2019 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-30523917

RESUMO

ZnO nanowire photodetectors have attracted much attention due to their excellent optoelectronic performance. However, operating speed remains a challenge, and scalability is also impeded by uncontrolled transfer methods and sophisticated fabrication process. In this paper, we have fabricated an excellent ZnO nanobridge ultraviolet photodetector array by using a simple one-step method. The faster photoresponse speed and a broader response wavelength (from UV to visible range) have been achieved by constructing a type-II ZnO/rubrene heterointerface. Performance enhancement is believed to arise from the well-matching band alignment and highly efficient separation of photogenerated electron-hole pairs at the heterointerface. Our strategy provides a simple and promising route to develop cost-effective and highly sensitive UV-vis photodetectors.

9.
Med Sci Monit ; 25: 6788-6796, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31501407

RESUMO

BACKGROUND KIAA1199 has been reported to be associated with malignant progression and poor clinical outcomes in various human malignancies. However, its clinical role and molecular function remain unknown in papillary thyroid cancer (PTC). MATERIAL AND METHODS The Cancer Genome Atlas (TCGA) was used to investigate the expression profiles of KIAA1199 and miR-486-5p in PTC. Immunohistochemistry was used to validate the protein expression of KIAA1199 in PTC. The Weighted Gene Co-expression Network Analysis (WGCNA) and Gene Set Enrichment Analysis (GSEA) were used to explore the potential pathway underling KIAA1199 in PTC. In vitro and in vivo experiments were performed to investigate the biological role of KIAA1199 in PTC progression. Luciferase reporter assays and Western blot analysis were performed to determine whether KIAA1199 is a downstream target of miR-486-5p. RESULTS We found that KIAA1199 was aberrantly elevated in PTC tissues compared with normal tissues, and upregulation of KIAA1199 was positively correlated with more advanced clinical variables. Additionally, bioinformatic analysis indicated that KIAA1199 was involved in cell migration and invasion. KIAA1199 silencing inhibited the invasive ability of PTC cells by affecting epithelial-mesenchymal transition (EMT) in vitro and in vivo. Furthermore, miR-486-5p was identified as an upstream microRNA that directly targets the 3'-UTR region of KIAA1199. CONCLUSIONS The miR-486-5p/KIAA1199/EMT axis might play a critical role in PTC invasion and metastasis and offers a potential therapeutic strategy for PTC.


Assuntos
Transição Epitelial-Mesenquimal/genética , Hialuronoglucosaminidase/metabolismo , MicroRNAs/metabolismo , Câncer Papilífero da Tireoide/genética , Câncer Papilífero da Tireoide/patologia , Animais , Sequência de Bases , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Hialuronoglucosaminidase/genética , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Invasividade Neoplásica , Regulação para Cima/genética
10.
Nano Lett ; 18(6): 3414-3420, 2018 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-29781625

RESUMO

Semiconductor nanowire (NW) lasers have attracted considerable research effort given their excellent promise for nanoscale photonic sources. However, NW lasers currently exhibit poor directionality and high threshold gain, issues critically limiting their prospects for on-chip light sources with extremely reduced footprint and efficient power consumption. Here, we propose a new design and experimentally demonstrate a vertically emitting indium phosphide (InP) NW laser structure showing high emission directionality and reduced energy requirements for operation. The structure of the laser combines an InP NW integrated in a cat's eye (CE) antenna. Thanks to the antenna guidance with broken asymmetry, strong focusing ability, and high Q-factor, the designed InP CE-NW lasers exhibit a higher degree of polarization, narrower emission angle, enhanced internal quantum efficiency, and reduced lasing threshold. Hence, this NW laser-antenna system provides a very promising approach toward the achievement of high-performance nanoscale lasers, with excellent prospects for use as highly localized light sources in present and future integrated nanophotonics systems for applications in advanced sensing, high-resolution imaging, and quantum communications.

11.
Opt Express ; 26(24): 31965-31975, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30650775

RESUMO

Wide-bandgap inorganic semiconductors based ultraviolet lasers bring versatile applications with significant advantages including low-power consumption, high-power output, robustness and long-term operation stability. However, flexible membrane lasers remain challenging predominantly due to the need for a lattice matched supporting substrate. Here, we develop a simple laser liftoff process to make freestanding single crystalline ZnO membranes that demonstrate low-threshold ultraviolet stimulated emissions together with large sized dimension (> 2 mm), ultralow-weight (m/A<15 g/m2) and excellent flexibility. The 2.6 µm-thick crack-free ZnO membrane exhibits well-retained single crystallinity and enhanced excitonic emissions while the defect-related emissions are completely suppressed. The inelastic exciton-exciton scattering stimulated emissions with increased spontaneous emission rate is obtained with a reduced threshold of 0.35 MW/cm2 in the ZnO membrane transferred onto a flexible polyethylene naphthalate substrate. Theoretical simulations reveal that it is a synergetic effect of the increased quantum efficiency via Purcell effect and the improved optical gain due to vertical directional waveguiding of the membrane, which functions as a Fabry-Perot photonic resonator due to the refractive index contrast at ZnO-air boundaries. With simple architecture, efficient exciton recombination and easy fusion with waveguide system, the ZnO membranes provide an alternative platform to develop compact low-threshold ultraviolet excitonic lasers.

12.
Connect Tissue Res ; 59(1): 55-65, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28267379

RESUMO

Purpose/Aim of the study: To evaluate the biomechanical characteristics and biocompatibility of an injectable, biodegradable calcium phosphate cement (CPC) containing poly lactic-co-glycolic acid (PLGA). MATERIALS AND METHODS: A vertebral compression fracture model was established using 20 human cadaveric vertebrae (T11-L3) divided into CPC/PLGA composite versus PMMA groups for biomechanical testing. In addition, 35 New Zealand rabbits were used to evaluate biodegradability and osteoconductive properties of CPC/PLGA using a bone defect model. In vitro cytotoxicity was evaluated by culturing with L929 cells. RESULTS: The CPC/PLGA composite effectively restored vertebral biomechanical properties. Compared with controls, the maximum load and compression strength of the CPC/PLGA group were lower, and stiffness was lower after kyphoplasty (all p <.05). Degradation was much slower in the control CPC compared with CPC/PLGA group. The bone tissue percentage in the CPC/PLGA group (44.9 ± 23.7%) was significantly higher compared with control CPC group (25.7 ± 10.9%) (p <.05). The viability of cells cultured on CPC/PLGA was greater than 70% compared with the blanks. CONCLUSIONS: Our biodegradable CPC/PLGA composite showed good biomechanical properties, cytocompatibility, and osteoconductivity and may represent an ideal bone substitute for future applications.


Assuntos
Cimentos Ósseos , Fosfatos de Cálcio , Fraturas por Compressão/terapia , Teste de Materiais , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Fraturas da Coluna Vertebral/terapia , Animais , Cimentos Ósseos/química , Cimentos Ósseos/farmacologia , Fosfatos de Cálcio/química , Fosfatos de Cálcio/farmacologia , Linhagem Celular , Modelos Animais de Doenças , Feminino , Fraturas por Compressão/metabolismo , Fraturas por Compressão/patologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Coelhos , Fraturas da Coluna Vertebral/metabolismo , Fraturas da Coluna Vertebral/patologia
13.
Nanotechnology ; 29(11): 115204, 2018 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-29345248

RESUMO

Recently, ZnO nanowire field effect transistors (FETs) have received renewed interest due to their extraordinary low dimensionality and high sensitivity to external chemical environments and illumination conditions. These prominent properties have promising potential in nanoscale chemical and photo-sensors. In this article, we have fabricated ZnO nanowire FETs and have found hysteresis behavior in their transfer characteristics. The mechanism and dynamics of the hysteresis phenomena have been investigated in detail by varying the sweeping rate and range of the gate bias with and without light irradiation. Significantly, light irradiation is of great importance on charge trapping by regulating adsorption and desorption of oxygen at the interface of ZnO/SiO2. Carriers excited by light irradiation can dramatically promote trapping/detrapping processes. With the assistance of light illumination, we have demonstrated a photon-assisted nonvolatile memory which employs the ZnO nanowire FET. The device exhibits reliable programming/erasing operations and a large on/off ratio. The proposed proto-type memory has thus provided a possible novel path for creating a memory functionality to other low-dimensional material systems.

14.
J Mater Sci Mater Med ; 29(9): 149, 2018 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-30182158

RESUMO

In a minimally invasive surgery, using a bone cement being radiologically detectable is vital to the success of the procedure and avoiding cement leakage in the early stage. The radiopacity of calcium phosphate cement (CPC) is inadequate, thus limiting its clinic application in this area. In this work, bismuth aluminate (BiA) was employed as a radiopaque agent for CPC. The influences of BiA on physicochemical, radiopaque and in vitro biocompatible properties of CPC were investigated. With the increasing content of BiA, the setting time and the compressive strength of CPC were augmented, while the injectability of the cement pastes was reduced. The radiopacity of CPC was significantly improved by adding more than 6 wt.% BiA. CPC specimens with less than 12 wt.% BiA showed good cellular affinity. Moreover, the CPC containing 6 and 9 wt.% BiA promoted the cell growth and ALP activity of mouse bone marrow mesenchymal stem cells when compared with the control. On the basis of its improved radiopacity and cytocompatibility, the radiopaque CPC with 6 ~ 9 wt.% BiA is expected to be a potential substitute for bone defect restoration via minimally invasive surgery. CPC with bismuth aluminate reveals better radiopacity and cell affinity along with proper physicochemical properties.


Assuntos
Alumínio/química , Bismuto/química , Cimentos Ósseos/química , Fosfatos de Cálcio/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Fosfatase Alcalina/metabolismo , Alumínio/farmacologia , Animais , Bismuto/farmacologia , Cimentos Ósseos/farmacologia , Fosfatos de Cálcio/farmacologia , Adesão Celular , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Teste de Materiais , Camundongos
15.
J Mater Sci Mater Med ; 29(12): 183, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30511166

RESUMO

The inferior anti-washout property of injectable calcium phosphate cement (CPC) limits its wider application in clinic. In this study, the improvement of anti-washout performance of CPC by addition of konjac glucomannan or guar gum, which was dissolved in the CPC liquid, was first studied. The influence of KGM/GG blend with different mass ratios on the anti-washout property, compressive strength and in vitro cytocompatibility of CPC was estimated. The results revealed that small amount of KGM or GG could obviously enhance the anti-washout property of CPC. Moreover, the washout resistance efficiency of KGM/GG blend was better than KGM or GG alone. The addition of KGM/GG blend slightly shortened the final setting time of CPC. Although the introduction of KGM/GG blend reduced the compressive strength of CPC, the compressive strength still reached or surpassed that of human cancellous bone. The best KGM/GG mass ratio was 5:5, which was most efficient at not only reducing CPC disintegration, but also increasing compressive strength. The addition of KGM/GG blend obviously promoted the cells proliferation on the CPC. In short, the CPC modified by KGM/GG blend exhibited excellent anti-washout property, appropriate setting time, adequate compressive strength, and good cytocompatibility, and has the potential to be used in bone defect repair. The addition of KGM/GG blend significantly improved the anti-washout property of CPC. The best KGM/GG mass ratio was 5:5, which was most efficient in reducing the CPC disintegration.


Assuntos
Cimentos Ósseos/química , Fosfatos de Cálcio/química , Galactanos/química , Mananas/química , Gomas Vegetais/química , Animais , Adesão Celular/fisiologia , Proliferação de Células , Força Compressiva , Cimentos Dentários , Teste de Materiais , Células-Tronco Mesenquimais/fisiologia , Camundongos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Viscosidade
16.
Opt Express ; 22(13): 15949-56, 2014 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-24977850

RESUMO

The enhancement of photo-response in nanometer-scale germanium photodetectors through bull's eye antennas capable of supporting 2nd-order Bloch surface plasmon modes is demonstrated in theory and experiment. A detailed numerical investigation reveals that the presence of surface wave and its constructive interference with the directly incident light are incorporated into the main mechanisms for enhancing transmission through the central nanoaperture. With a grating period of 1500 nm, the area-normalized responsivity can be enhanced up to 3.8 times at 2 V bias for a 780 nm laser. It provides an easier fabrication path for ultra-short wavelength operations especially in devices using optically denser materials.

17.
Artigo em Inglês | MEDLINE | ID: mdl-39422442

RESUMO

Improving the thermal conductance at the GaN/diamond interface is crucial for boosting GaN-based device performance and reliability. In this study, first-principles calculations and molecular dynamics simulations were employed to explore the interfacial thermal conductance of GaN/diamond interfaces with AlxGa1-xN transition layers. The AlxGa1-xN alloy exhibits a lower thermal conductivity than GaN, primarily due to enhanced anharmonic phonon scattering. However, for the interfacial thermal conductance at the GaN/diamond interface, we discovered that introducing an AlxGa1-xN with a high Al concentration (x > 0.5) as a phonon bridge between GaN and diamond can significantly enhance the interfacial thermal conductance. In particular, it increases from 4.79 MW·m-2 K-1 to a maximum of 158 MW·m-2 K-1 at x = 0.75, surpassing the 152 MW·m-2 K-1 achieved by AlN. The AlxGa1-xN alloy has been confirmed computationally as a more efficient phonon bridge, which can provide a valuable theoretical reference for experimentally investigating the thermal management and thermal design of high-power electronic devices based on the GaN/diamond interface.

18.
Mater Today Bio ; 28: 101203, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39221203

RESUMO

Biphasic calcium phosphate (BCP) ceramics are valued for their osteoconductive properties but have limited osteogenic and angiogenic activities, which restricts their clinical utility in bone defect repair. Silicon doping has emerged as an effective strategy to enhance these biological functions of BCP. However, the biological impact of BCP is influenced by the level of silicon doping, necessitating determination of the optimal concentration to maximize efficacy in bone repair. This study investigated the effects of silicon doping on both the physicochemical and biological properties of BCP, with a specific focus on osteogenic and angiogenic potentials. Results indicated that silicon doping exceeding 4 mol.% led to the formation of α-TCP, accelerating BCP degradation, enhancing silicon ion release, and promoting mineralization product formation. Simultaneously, silicon doping increased the porosity of BCP scaffolds, which typically reduces their compressive strength. Nevertheless, scaffolds doped with ≤4 mol.% silicon maintained compressive strengths exceeding 2 MPa. In vitro biological experiments indicated that higher levels of silicon doping (≥6 mol.%) partially inhibited the successful differentiation of stem cells and the vascularization of endothelial cells. Optimal conditions for promoting osteogenic differentiation and angiogenesis were identified between 2 and 4 mol.% silicon doping, with an optimal level of approximately 4 mol.%. Subsequent in vivo experiments confirmed that BCP scaffolds doped with 4 mol.% silicon effectively promoted vascularization and new bone formation, highlighting their potential for clinical bone defect repair.

19.
Biomed Mater ; 19(3)2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38518361

RESUMO

Rapid bone regeneration in implants is important for successful transplantation. In this regard, we report the development of calcium silicate/zinc silicate (CS/ZS) dual-compound-incorporated calcium phosphate cement (CPC) scaffolds with a three-dimensional poly (lactic-co-glycolic acid) network that synergistically promote bone regeneration.In vitroresults demonstrated that the incorporation of CS/ZS dual compounds into the CPC significantly promoted the osteogenic differentiation of stem cells compared to the addition of CS or ZS alone. Moreover, the bone-regeneration efficacy of the composite scaffolds was validated by filling in femur condyle defects in rabbits, which showed that the scaffolds with CS and ZS possessed a great bone repair effect, as evidenced by more new bone formation and a faster scaffold biodegradation compared to the scaffold with CS alone.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Compostos de Zinco , Animais , Coelhos , Alicerces Teciduais , Zinco/farmacologia , Proliferação de Células , Compostos de Cálcio , Regeneração Óssea , Silicatos , Fosfatos de Cálcio/farmacologia
20.
J Phys Chem Lett ; 15(2): 556-564, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38198134

RESUMO

The human brain efficiently processes only a fraction of visual information, a phenomenon termed attentional control, resulting in energy savings and heightened adaptability. Translating this mechanism into artificial visual neurons holds promise for constructing energy-efficient, bioinspired visual systems. Here, we propose a self-rectifying artificial visual neuron (SEVN) based on a NiO/Ga2O3 bipolar heterojunction with attentional control on patterns with a target color. The device exhibits short-term potentiation (STP) with quantum point contact (QPC) traits at low bias and transitions to long-term potentiation (LTP) at high bias, particularly facilitated by electron capture in deep defects upon ultraviolet (UV) exposure. With the utilization of two wavelengths of light upon the target and interference part of CAPTCHA to simulate top-down attentional control, the recognition accuracy is enhanced from 74 to 84%. These findings have the potential to augment the visual capability of neuromorphic systems with implications for diverse applications, including cybersecurity, healthcare, and machine vision.


Assuntos
Encéfalo , Sinapses , Humanos , Sinapses/fisiologia , Neurônios
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