Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Phys Chem Chem Phys ; 26(22): 16253-16260, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38804578

RESUMO

Dynamic infrared radiation regulation has been widely explored for smart windows because of its vital importance for comfortable and energy-efficient buildings. However, it remains a great challenge to synchronously achieve high visible transmittance and pronounced infrared tunability. Here, we propose a dynamic infrared tunable metamaterial composed of indium tin oxide (ITO) gratings, an air insulator, and an ITO reflector. The ITO grating-based infrared radiation regulator exhibits a high emissivity tunability of 0.73 at 8-13 µm while maintaining a high visible transmittance of 0.65 and 0.72 before and after actuation, respectively. By adjusting the geometric parameters, the tunable bandwidth can be further extended to 3-30 µm and the ultra-broadband tunability reaches 0.62. The excellent infrared tunable performance arises from the insulator thickness-dependent effect of Fabry-Pérot and propagating surface plasmon resonance coupling and decoupling, which lead to perfect and low absorption, respectively. This work provides potential for the advancement of smart window technology and makes a significant contribution to sustainable buildings.

2.
Angew Chem Int Ed Engl ; : e202411871, 2024 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-39054405

RESUMO

Advancing catalyst design is pivotal for the enhancement of photocatalytic processes in renewable energy conversion. The incorporation of structural chirality into conventional inorganic solar hydrogen nanocatalysts promises a significant transformation in catalysis, a feature absent in this field. Here we unveil the unexplored potential of geometric chirality by creating a chiral composite that integrates geometric chiral Au nanoparticles (NPs) with two-dimensional C3N4 nanosheets, significantly boosting photocatalytic H2 evolution beyond the achiral counterparts. The superior performance is driven by the geometric chirality of Au NPs, which facilitates efficient charge carrier separation through the favorable C3N4-chiral Au NP interface and chiral induced spin polarization, and exploits high-activity facets within the concave surfaces of chiral Au NPs. The resulting synergistic effect leads to a remarkable increase in photocatalytic H2 evolution, with an apparent quantum yield of 44.64% at 400 nm. Furthermore, we explore the selective polarized photo-induced carrier separation behavior, revealing a distinct chiral-dependent photocatalytic HER performance. Our work advances the design and utilization of chiral inorganic nanostructures for superior performance in energy conversion processes.

3.
Nanotechnology ; 35(5)2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37883949

RESUMO

Selective mid-infrared (MIR) radiation is highly desirable in many applications. However, there are still great challenges to simultaneously achieve MIR camouflage and radiative cooling utilizing simple structure. This work theoretically and experimentally proposes a bi-layer metamaterial composed of aluminum doped zinc oxide (AZO) nanoparticles embedded in Al2O3matrix on the aluminum film. The bi-layer metamaterial exhibits high performance in MIR camouflage with radiative cooling, a low emissivity (ε3-5µm= 0.11,ε8-14µm= 0.20) in atmospheric windows and a high emissivity (ε5-8µm= 0.81) in non-atmospheric windows. The interaction of the epsilon-near-zero (ENZ) mode and localized surface plasmon resonance (LSPR) mode is responsible for the perfect emission over the wavelength range of 5-8µm. Additionally, the proposed selective MIR emitter supports large-angle incidence and has great polarization insensitivity. This demonstrates that epsilon-near-zero material-based bi-layer metamaterial is highly promising for the development of selective mid-infrared radiation.

4.
J Integr Plant Biol ; 65(1): 133-149, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36194508

RESUMO

Camptothecin (CPT) is an anticancer pentacyclic quinoline alkaloid widely used to treat cancer patients worldwide. However, the biosynthetic pathway and transcriptional regulation of camptothecin are largely unknown. Ophiorrhiza pumila, the herbaceous plant from the Rubiaceae family, has emerged as a model plant for studying camptothecin biosynthesis and regulation. In this study, a high-quality reference genome of O. pumila with estimated size of ~456.90 Mb was reported, and the accumulation level of camptothecin in roots was higher than that in stems and leaves. Based on its spatial distribution in the plant, we examined gene functions and expression by combining genomics with transcriptomic analysis. Two loganic acid O-methyltransferase (OpLAMTs) were identified in strictosidine-producing plant O. pumila, and enzyme catalysis assays showed that OpLAMT1 and not OpLAMT2 could convert loganic acid into loganin. Further knock-out of OpLAMT1 expression led to the elimination of loganin and camptothecin accumulation in O. pumila hairy roots. Four key residues were identified in OpLAMT1 protein crucial for the catalytic activity of loganic acid to loganin. By co-expression network, we identified a NAC transcription factor, OpNAC1, as a candidate gene for regulating camptothecin biosynthesis. Transgenic hairy roots and biochemical assays demonstrated that OpNAC1 suppressed OpLAMT1 expression. Here, we reported on two camptothecin metabolic engineering strategies paving the road for industrial-scale production of camptothecin in CPT-producing plants.


Assuntos
Antineoplásicos Fitogênicos , Antineoplásicos , Rubiaceae , Camptotecina/farmacologia , Camptotecina/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Antineoplásicos/metabolismo , Plantas/metabolismo , Rubiaceae/genética , Rubiaceae/metabolismo
5.
Nanotechnology ; 31(28): 282001, 2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32240995

RESUMO

Artificial photosynthesis is an effective way to convert solar energy into fuels, which is of great significance to energy production and reduction of atmospheric CO2 content. In recent years, 3D structured artificial photosynthetic system has made great progress as an effective design strategy. This review first highlights several typical mechanisms for improved artificial photosynthesis with 3D structures: improved light harvesting, mass transfer and charge separation. Then, we summarize typical examples of 3D structured artificial photosynthetic systems, including bioinspired structures, photonic crystals (PC), designed photonic structures (PC coupling structure, plasmon resonance structure, optical resonance structure, metamaterials), 3D-printed systems, nanowire integrated systems and hierarchical 3D structures. Finally, we discuss the problems and challenges to the application and development of 3D artificial photosynthetic system and the possible trends of future development. We hope this review can inspire more progress in the field of artificial photosynthesis.

6.
Water Res ; 242: 120140, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37327544

RESUMO

Water and energy are critical components of urban metabolism. However, climate change-induced water scarcity and elevated temperatures pose a significant threat to the adequate supply of essential human services, including sanitation and space cooling, particularly in coastal cities where over 40% of the population resides. The water-energy nexus of sanitation and space cooling is crucial for promoting sustainability and resilience in coastal cities. For decades, Hong Kong has demonstrated the effectiveness of using seawater for toilet flushing and district cooling to save water and energy, which could serve as a potential solution for other coastal cities worldwide. Seawater is a superior alternative to other sources of toilet flushing water due to its abundant availability, easy detection of cross-contamination, and lower treatment costs. Furthermore, saline wastewater treatment requires fewer materials and energy inputs and produces less sludge. Using seawater for district cooling also saves energy without exacerbating water stress. However, there is a lack of comprehensive insights from Hong Kong on how seawater use can be adopted by other coastal cities to promote sustainable development. A successful introduction of seawater into coastal cities requires a holistic water-energy management framework that provides technical and policy-level guidance. We developed such a framework that follows four sustainability principles, namely customized solutions, efficient resource allocation, comprehensive evaluation, and optimized tradeoffs. These principles are designed into contextualized location analysis, urban spatial analysis, integrated sustainability assessment, and nexus analysis. The results of these analyses can aid decision-making regarding the technical and policy aspects of seawater uses in sanitation and space cooling to maximize the positive impacts on sustainable development. Breaking barriers between sectors and encouraging inter-municipal cooperation between sectors are critical to the successful use of seawater. By adopting this framework and promoting collaboration across different sectors, coastal cities can enhance their sustainability and resilience, providing a better quality of life for their citizens.

7.
Adv Mater ; 35(41): e2302844, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37402134

RESUMO

Manipulation of the electromagnetic signature in multiple wavebands is necessary and effective in civil and industrial applications. However, the integration of multispectral requirements, particularly for the bands with comparable wavelengths, challenges the design and fabrication of current compatible metamaterials. Here, a bioinspired bilevel metamaterial is proposed for multispectral manipulation involving visible, multi-wavelength detection lasers and mid-infrared (MIR), along with radiative cooling. The metamaterial, consisting of dual-deck Pt disks and a SiO2 intermediate layer, is inspired by the broadband reflection splitting effect found in butterfly scales and achieves ultralow specular reflectance (average of 0.013) over the entire 0.8-1.6 µm with large scattering angles. Meanwhile, tunable visible reflection and selective dual absorption peaks in MIR can be simultaneously realized, providing structural color, effective radiative thermal dissipation at 5-8 µm and 10.6 µm laser absorption. The metamaterial is fabricated by a low-cost colloidal lithography method combined with two patterning processes. Multispectral manipulation performances are experimentally demonstrated and a significant apparent temperature drop (maximum of 15.7 °C) compared to the reference is observed under a thermal imager. This work achieves optical response in multiple wavebands and provides a valuable way to effectively design multifunctional metamaterials inspired by nature.

8.
Int J Biol Macromol ; 242(Pt 3): 124910, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37217041

RESUMO

Ophiorrhiza pumila, as a folk herb belonging to the Rubiaceae family, has become a potential source of camptothecin (CPT), which is a monoterpenoid indole alkaloid with good antitumor property. However, the camptothecin content in this herb is low, and is far from meeting the increasing clinical demand. Understanding the transcriptional regulation of camptothecin biosynthesis provides an effective strategy for improvement of camptothecin yield. Previous studies have demonstrated several transcription factors that are related to camptothecin biosynthesis, while the functions of HD-ZIP members in O. pumila have not been investigated yet. In this study, 32 OpHD-ZIP transcription factor members were genome-wide identified. Phylogenetic tree showed that these OpHD-ZIP proteins are divided into four subfamilies. Based on the transcriptome data, nine OpHD-ZIP genes were shown to be predominantly expressed in O. pumila roots, which were in line with the camptothecin biosynthetic genes. Co-expression analysis showed that OpHD-ZIP7 and OpHD-ZIP20 were potentially related to the modulation of camptothecin biosynthesis. Dual-luciferase reporter assays (Dual-LUC) showed that both OpHD-ZIP7 and OpHD-ZIP20 could activate the expression of camptothecin biosynthetic genes OpIO and OpTDC. In conclusion, this study offered the promising data for exploring the roles of OpHD-ZIP transcription factors in regulating camptothecin biosynthesis.


Assuntos
Proteínas de Transporte de Cátions , Rubiaceae , Camptotecina , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Filogenia , Proteínas de Transporte de Cátions/genética , Retículo Endoplasmático/metabolismo , Zinco/metabolismo , Rubiaceae/genética
9.
J Colloid Interface Sci ; 608(Pt 1): 493-503, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34626991

RESUMO

Zeolitic imidazolate framework-67 (ZIF67) derivatives are considered as promising active materials for energy storage owing to the possible formation of cobalt oxide and N-doped graphite. Cobalt oxide has multiple redox states for generating redox reactions for charge storage, while N-doped graphite can provide high electrical conductivity for charge transfer. In this study, it is the first time to synthesize binder-free electrodes composed of cobalt oxide and N-doped graphite derived from ZIF67 on carbon cloth (CC) for supercapacitor (SC). Successive oxidation and carbonization along with additional coverage of ZIF67 derivatives are applied to synthesize ZIF67 derivatives composed of cobalt oxide, N-doped graphite and cobalt oxide/N-doped graphite composites with different layer compositions. The highest specific capacitance (CF) of 90.0F/g at 20 mV/s is obtained for the oxidized ZIF67/carbonized ZIF67/carbon cloth (O67/C67/CC) electrode, due to the large surface area and high electrical conductivity benefitted from preferable morphology and growing sequence of Co3O4 and N-doped graphite. The symmetric SC composed of O67/C67/CC electrodes shows the maximum energy density of 2.53 Wh/kg at the power density of 50 W/kg. Cycling stability with CF retention of 70% and Coulombic efficiency of 65% after 6000 times repeatedly charge/discharge process is also obtained for this symmetric SC.

10.
Int J Gynaecol Obstet ; 149(1): 16-23, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31833058

RESUMO

OBJECTIVE: To evaluate the prognosis of women with distant metastasis at the time of endometrial cancer (EC) diagnosis and identify prognostic factors according to metastatic site. METHODS: A retrospective cohort study of women diagnosed with EC according to the SEER database between 2010 and 2014. Univariate and multivariate Cox regression was used to identify variables associated with overall survival. Kaplan-Meier curves were used to compare survival among different groups. RESULTS: Overall, 2948 women with stage IV EC were identified. The most common distant metastatic site was the lung. Having a distant metastatic site independently predicted overall survival. Using brain metastasis as a reference, overall survival was longer for liver (P=0.049), lung (P=0.005), and bone (P=0.019) metastasis. Relative to no distant metastasis, overall survival was shorter for women with one (P<0.001) or two or more (P<0.001) sites of distant metastasis. Overall survival was independently influenced by tumor grade, insurance status, and surgery among women with only lung metastasis. CONCLUSION: The findings showed that the prognosis of women with stage IV EC differs by distant metastatic site, and identified several predictors of poor survival. They may help clinicians to better predict prognosis for newly diagnosed cases of EC with distant metastasis.


Assuntos
Neoplasias Ósseas/mortalidade , Neoplasias Encefálicas/mortalidade , Neoplasias do Endométrio/patologia , Neoplasias Hepáticas/mortalidade , Neoplasias Pulmonares/mortalidade , Adulto , Idoso , Neoplasias Ósseas/secundário , Neoplasias Encefálicas/secundário , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Programa de SEER/estatística & dados numéricos
11.
Mol Cancer Res ; 18(2): 204-215, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31662448

RESUMO

Ubiquitin-conjugating enzyme E2C (UBE2C) plays important roles in tumor progression; nevertheless, its function in endometrial cancer remains unclear. This study elucidated the impact of UBE2C on endometrial cancer and its underlying mechanism. Human endometrial cancer and normal endometrial tissues were acquired from patients at Wuhan Union Hospital and UBE2C expression was detected by Western blotting and qRT-PCR. Endometrial cancer cells were transfected with a UBE2C overexpression plasmid or UBE2C-specific short hairpin RNA (shRNA) to up- or downregulate UBE2C expression, respectively. CCK8 and transwell assays were applied to assess the effects of UBE2C on cell proliferation, migration, and invasion. We found a significant elevation of UBE2C expression in patients with endometrial cancer, and that UBE2C upregulation was associated with advanced histologic grade, FIGO stage, recurrence, and shorter overall survival. UBE2C knockdown inhibited endometrial cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT), whereas UBE2C overexpression exerted the opposite effects. UBE2C downregulation increased p53 and its downstream p21 expression, with p53 overexpression reversing the EMT-promoting effects of UBE2C. UBE2C enhanced p53 ubiquitination to facilitate its degradation in endometrial cancer cells. Estradiol (E2) induced UBE2C expression via estrogen receptor α, which binds directly to the UBE2C promoter element. Silencing of UBE2C inhibited E2-promoted migration, invasion, and EMT in vitro and in vivo. IMPLICATIONS: UBE2C-mediated tumor EMT promotion by estrogen is a novel mechanism for the progression of estrogen-induced endometrial cancer, which could offer new biomarkers for diagnosis and therapy of endometrial cancer in the future.


Assuntos
Neoplasias do Endométrio/genética , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Enzimas de Conjugação de Ubiquitina/genética , Animais , Neoplasias do Endométrio/patologia , Estrogênios/farmacologia , Feminino , Humanos , Camundongos , Camundongos Nus , Transfecção , Regulação para Cima
12.
Tob Induc Dis ; 17: 48, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31516491

RESUMO

INTRODUCTION: We evaluate the effectiveness and safety of transdermal acupuncture by needles for smoking cessation. METHODS: A literature search for randomized controlled trials (RCTs) was performed in seven electronic databases from inception to February 2017. Meta-analysis was conducted using Revman 5.3.0 software. We used either a random effects model (REM) or a fixed effects model (FEM) for pooling data according to the result of a heterogeneity test (defined as significant if I2>75%). Trial sequential analysis (TSA) was applied by TSA 0.9.5.10 Beta software. RESULTS: Twenty-four trials involving 3984 participants were included. The methodological quality was generally low. With regard to smoking abstinence, meta-analysis showed acupuncture was more effective compared to no intervention/waiting list for short-term (4 weeks) cessation (1 trial, RR=2.37, 95% 1.41, 3.97) and long-term (longer than 6 months) (2 trials, RR=2.66, 95% CI: 1.50, 4.70). Compared to acupuncture/auricular acupressure alone, acupuncture plus auricular acupressure showed more benefit for short-term cessation (3 trials, RR=1.52, 95% CI: 1.03, 2.25). Acupuncture plus auricular acupressure was more effective compared to sham acupuncture plus sham auricular acupressure for short-term cessation (3 trials, RR=2.50, 95% CI: 1.44, 4.33) and long-term (2 trials, RR=3.61, 95% CI: 1.37, 9.48). Acupuncture in combination with counseling, educational smoking cessation program or moxibustion had more benefit compared to acupuncture for short-term cessation (3 trials, RR=0.75, 95% 0.63, 0.91) and long-term (2 trials, RR=0.77, 95% CI: 0.56, 1.05), and TSA illustrated the cumulative Z-curve of this comparison for long-term across the traditional boundary of 5% significance and monitoring boundaries. No serious adverse events occurred. CONCLUSIONS: Acupuncture combined with counseling, educational smoking cessation program or moxibustion was more effective than acupuncture as monotherapy with regard to long-term smoking cessation. Further, high quality trials are needed to confirm the result.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA