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1.
Adv Mater ; : e2404199, 2024 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-38734974

RESUMO

External stimuli triggering chemical reactions in cancer cells to generate highly reactive chemical species are very appealing for cancer therapy, in which external irradiation activating sensitizers to transfer energy or electrons to surrounding oxygen or other molecules is critical for generating cytotoxic reactive species. However, poor light penetration into tissue, low activity of sensitizers, and reliance on oxygen supply restrict the generation of cytotoxic chemical species in hypoxic tumors, which lowers the therapeutic efficacy. Here, we present galvanic cell nanomaterials that can directly release highly reactive electrons in tumors without external irradiation or photosensitizers. The released reactive electrons directly react with surrounding biomolecules such as proteins and DNA within tumors to destroy them or react with other surrounding (bio)molecules to yield cytotoxic chemical species to eliminate tumors independent of oxygen. Administering these nanogalvanic cells to mice results in almost complete remission of subcutaneous solid tumors and deep metastatic tumors. The results demonstrate that this strategy can further arouse an immune response even in a hypoxic environment. This method offers a promising approach to effectively eliminate tumors, similar to photodynamic therapy, but does not require oxygen or irradiation to activate photosensitizers. This article is protected by copyright. All rights reserved.

2.
Adv Mater ; : e2402000, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38738693

RESUMO

The disparity between growth substrates and application-specific substrates can be mediated by reliable graphene transfer, the lack of which currently strongly hinders the graphene applications. Conventionally, the removal of soft polymers, that support the graphene during the transfer, would contaminate graphene surface, produce cracks, and leave unprotected graphene surface sensitive to airborne contaminations. In this work, we found that polyacrylonitrile (PAN) can function as polymer medium for transferring wafer-size graphene, and encapsulating layer to deliver high-performance graphene devices. Therefore, PAN, that is compatible with device fabrication, does not need to be removed for subsequent applications. We achieved the crack-free transfer of 4-inch graphene onto SiO2/Si wafers, and the wafer-scale fabrication of graphene-based field-effect transistor (FET) arrays with no observed clear doping, uniformly high carrier mobility (∼11,000 cm2 V-1 s-1) and long-term stability at room temperature. Our work presents new concept for designing the transfer process of two-dimensional (2D) materials, in which multifunctional polymer can be retained, and offers a reliable method for fabricating wafer-scale devices of 2D materials with outstanding performance. This article is protected by copyright. All rights reserved.

3.
Nanoscale ; 16(16): 7862-7873, 2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38568087

RESUMO

Recent years have witnessed advances in chemical vapor deposition growth of graphene films on metal foils with fine scalability and thickness controllability. However, challenges for obtaining wrinkle-free, defect-free and large-area uniformity remain to be tackled. In addition, the real commercial applications of graphene films still require industrially compatible transfer techniques with reliable performance of transferred graphene, excellent production capacity, and suitable cost. Transferred graphene films, particularly with a large area, still suffer from the presence of transfer-related cracks, wrinkles and contaminants, which would strongly deteriorate the quality and uniformity of transferred graphene films. Potential applications of graphene films include moisture barrier films, transparent conductive films, electromagnetic shielding films, and optical communications; such applications call different requirements for the performance of transferred graphene, which, in turn, determine the suitable transfer techniques. Besides the reliable transfer process, automatic machines should be well developed for the future batch transfer of graphene films, ensuring the repeatability and scalability. This mini-review provides a summary of recent advances in the transfer of graphene films and offers a perspective for future directions of transfer techniques that are compatible for industrial batch transfer.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38165000

RESUMO

AIMS: To understand the compliance, influencing factors, and action path of family cardiac rehabilitation exercise prescriptions for children after congenital heart disease surgery. METHODS AND RESULTS: A random sampling method was used to select 200 pediatric patients and their parents from a pediatric hospital in Shanghai. Among them, 57 cases (28.5%) of children's families followed the cardiac rehabilitation exercise prescription. Path analysis showed that peak oxygen uptake exerted a negative impact on the compliance of family cardiac-rehabilitation prescriptions for patients after congenital heart disease surgery through doctor-patient trust, with a standardized path coefficient of -0.246 (P = 0.001). Disease-related knowledge exerted a positive effect on the compliance of family cardiac-rehabilitation prescriptions for children after congenital heart surgery through doctor-patient trust, with a standardized path coefficient of 0.353 (P < 0.001). The dimension of friend support in social support had a direct positive effect on the compliance of family cardiac-rehabilitation prescriptions for children after cardiac surgery, with a standardized path coefficient of 0.641 (P = 0.006). CONCLUSION: The compliance of cardiac rehabilitation exercise prescription in children with congenital heart disease is not good and is affected by many factors, and there is a complex path relationship between various factors; the kilogram oxygen consumption of the child, the disease-related knowledge of the caregiver, and social support all play important roles in the compliance of the child's family's health prescription. REGISTRATION: SCMCIRB-K2021002-1.

5.
Adv Mater ; 36(15): e2308950, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38288661

RESUMO

The real applications of chemical vapor deposition (CVD)-grown graphene films require the reliable techniques for transferring graphene from growth substrates onto application-specific substrates. The transfer approaches that avoid the use of organic solvents, etchants, and strong bases are compatible with industrial batch processing, in which graphene transfer should be conducted by dry exfoliation and lamination. However, all-dry transfer of graphene remains unachievable owing to the difficulty in precisely controlling interfacial adhesion to enable the crack- and contamination-free transfer. Herein, through controllable crosslinking of transfer medium polymer, the adhesion is successfully tuned between the polymer and graphene for all-dry transfer of graphene wafers. Stronger adhesion enables crack-free peeling of the graphene from growth substrates, while reduced adhesion facilitates the exfoliation of polymer from graphene surface leaving an ultraclean surface. This work provides an industrially compatible approach for transferring 2D materials, key for their future applications, and offers a route for tuning the interfacial adhesion that would allow for the transfer-enabled fabrication of van der Waals heterostructures.

6.
Polymers (Basel) ; 16(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38201820

RESUMO

To investigate the effect of the structure of microcapsules on the properties of cross-linked polyethylene (XLPE) composites, three XLPE specimens filled with multilayered shell-core-structured microcapsules are designed. In this paper, the microcapsules are first analyzed morphologically and chemically. In addition, the effect of the microcapsule structure on the typical electrical properties of the composites is explored. Finally, the self-healing ability of XLPE specimens filled with microcapsules is verified. The results show that the SiO2 on the surface of the trilayer shell-core microcapsules can make the microcapsules and the XLPE matrix have a better mechanical interlocking ability, which makes the typical properties of the trilayer shell-core microcapsules slightly better than those of the bilayer shell-core microcapsules. Moreover, when the bilayer shell-core or trilayer shell-core microcapsules rupture under the action of an electric field, the repair material reacts with the water tree under capillary action to consume the residual water while generating organic matter to fill in the cavity, thus repairing the damaged area of the water tree and ultimately achieving the self-healing of the composite water tree.

7.
J Environ Manage ; 352: 120131, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38266520

RESUMO

Accurately predicting carbon trading prices using deep learning models can help enterprises understand the operational mechanisms and regulations of the carbon market. This is crucial for expanding the industries covered by the carbon market and ensuring its stable and healthy development. To ensure the accuracy and reliability of the predictions in practical applications, it is important to evaluate the model's robustness. In this paper, we built models with different parameters to predict carbon trading prices, and proposed models with high accuracy and robustness. The accuracy of the models was assessed using traditional survey indicators. The robustness of the CNN-LSTM model was compared to that of the LSTM model using Z-scores. The CNN-LSTM model with the best prediction performance was compared to a single LSTM model, resulting in a 9% reduction in MSE and a 0.0133 shortening of the Z-score range. Furthermore, the CNN-LSTM model achieved a level of accuracy comparable to other popular models such as CEEMDAN, Boosting, and GRU. It also demonstrated a training speed improvement of at least 40% compared to the aforementioned methods. These results suggest that the CNN-LSTM enhances model resilience. Moreover, the practicality of using Z-score to evaluate model robustness is confirmed.


Assuntos
Aprendizado Profundo , Reprodutibilidade dos Testes , China , Carbono , Indústrias , Previsões
8.
Front Oncol ; 13: 1194462, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074668

RESUMO

Metabolomics analysis revealed the metabolic heterogeneity of cervical cancer (CC) cell lines C33A and CaSki, and their molecular mechanisms were explored. Using the modified Bligh-Dyer method, the endogenous metabolites of C33A and CaSki cells were divided into polar and nonpolar fractions. The metabolites were analysed by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Then, the differential metabolites were screened by combining multivariate statistical analysis and volcano maps, and functional enrichment and pathway analysis of the differential metabolites were performed. Finally, association analysis was carried out in combination with transcriptomics, and the important differential metabolisms were experimentally verified by real-time PCR (RT-qPCR) and oil red staining. The results showed that between the C33A and CaSki cell lines, there were significant differences in amino acids, nucleotides and lipids, such as in threonine, arachidonic acid and hypoxanthine, in the metabolic pathways. These compounds could be used as markers of differences in cellular metabolism. The heterogeneity of lipid metabolism accounted for 87.8%, among which C33A cells exhibited higher contents of fatty acid polar derivatives, while CaSki cells showed higher contents of free fatty acids and glycerides. Based on correlation analysis of the above metabolic differences in HPV pathways as well as lipid metabolism-related genes, p53 and the genes involved in lipid metabolism pathways, such as Peroxisome Proliferator Activated Receptor Gamma(PPARG) and stearoyl-CoA desaturase (SCD), are relevant to the metabolic heterogeneity of the cells. The differential expression of some genes was validated by RT-qPCR. CaSki cells showed significantly higher glyceride levels than that of C33A cells, as verified by oil red O staining and glyceride assays. The above results showed that the metabolomic differences between C33A and CaSki cells were relatively obvious, especially in lipid metabolism, which might be related to the decreased expression of PPARG and p53 caused by HPV E6. Further studies on the molecular mechanism of lipid metabolism heterogeneity in cervical cancer cell lines with or without HPV could provide a new reference for the development of CC and individualized treatments of tumour patients.

10.
Environ Geochem Health ; 45(11): 8787-8802, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37749354

RESUMO

The use of hexachlorocyclohexanes (HCHs) in pesticides has been prohibited for decades in China. Since then, there have been urbanization and transformation of the functional areas of many sites, which were formerly involved in the HCH industry. However, it is possible that, unless properly managed, these sites may still contain HCH residues in the soil and thus pose a threat to the surrounding environment and the quality of groundwater. This study aimed to characterize soil residues in a typical site that was historically involved in HCH production in southern China, by analyzing the α-HCH, ß-HCH, and γ-HCH contents of the soil. The results suggested that HCHs persist in the environment and can have long-term effects. It was found that α-HCH and ß-HCH were present in many samples in concentrations that were comparable or higher than those specified by China's Class 1 screening values. The distribution of residues was significantly correlated with the historical HCH production activities in the areas. The characteristic ratios of α-HCH/γ-HCH and ß-HCH/(α + γ)-HCH at different soil depths were 1.4-3.7 and 0.21-1.04, respectively, which indicated the presence of significant localized residues of HCHs. The presence of HCHs in the soil suggested a downward migration, with concentrations rapidly decreasing in the upper layer soil (0-5 m), but a gradual increase in the deeper soil (5-14 m). HCHs were detected at depths exceeding 24 m, indicating heavy penetration. The proportions of γ-HCH and ß-HCH changed with increasing soil depth, which was related to their relatively volatile and stable molecular structures, respectively. The results strongly suggested that there is widespread contamination of both soil and groundwater by HCHs even after decades. The likelihood of residual HCHs in the soil should therefore be taken into full consideration during urban planning to limit risks to human and environmental health.


Assuntos
Água Subterrânea , Hidrocarbonetos Clorados , Praguicidas , Poluentes do Solo , Humanos , Hexaclorocicloexano/análise , Solo/química , Monitoramento Ambiental , Praguicidas/análise , Hidrocarbonetos Clorados/análise , Poluentes do Solo/análise , China
11.
Nano Lett ; 23(16): 7716-7724, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37539976

RESUMO

Graphene films that can theoretically block almost all molecules have emerged as promising candidate materials for moisture barrier films in the applications of organic photonic devices and gas storage. However, the current barrier performance of graphene films does not reach the ideal value. Here, we reveal that the interlayer distance of the large-area stacked multilayer graphene is the key factor that suppresses water permeation. We show that by minimizing the gap between the two monolayers, the water vapor transmission rate of double-layer graphene can be as low as 5 × 10-3 g/(m2 d) over an A4-sized region. The high barrier performance was achieved by the absence of interfacial contamination and conformal contact between graphene layers during layer-by-layer transfer. Our work reveals the moisture permeation mechanism through graphene layers, and with this approach, we can tailor the interlayer coupling of manually stacked two-dimensional materials for new physics and applications.

12.
J Environ Manage ; 342: 118108, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37201390

RESUMO

The performance, microbial enzymatic activity and microbial community of a sequencing batch reactor (SBR) were explored under instantaneous Cd(II) shock loading. After a 24-h Cd(II) shock loading of 100 mg/L, the chemical oxygen demand and NH4+-N removal efficiencies decreased significantly from 92.73% and 99.56% on day 22 to 32.73% and 43% on day 24, respectively, and then recovered to the normal values gradually. The specific oxygen utilization rate (SOUR), specific ammonia oxidation rate (SAOR), specific nitrite oxidation rate (SNOR), specific nitrite reduction rate (SNIRR) and specific nitrate reduction rate (SNRR) decreased by 64.81%, 73.28%, 77.77%, 56.84% and 52.46% on day 23 in comparison with the absence of Cd(II) shock loading, respectively, and they gradually returned to the normal levels. The changing trends of their associated microbial enzymatic activities including dehydrogenase, ammonia monooxygenase, nitrite oxidoreductase, nitrite reductase and nitrate reductase were in accordance with SOUR, SAOR, SNOR, SNIRR and SNRR, respectively. Cd(II) shock loading promoted the microbial reactive oxygen species production and lactate dehydrogenase release, indicating that instantaneous shock caused oxidative stress and damaged to cell membranes of the activated sludge. The microbial richness and diversity, and the relative abundance of Nitrosomonas and Thauera obviously decreased under the stress of Cd(II) shock loading. PICRUSt prediction showed that Cd (II) shock loading significantly affected Amino acid biosynthesis, Nucleoside and nucleotide biosynthesis. The present results are conducive to take adequate precautions to reduce the adverse effect on bioreactor performance in wastewater treatment systems.


Assuntos
Cádmio , Microbiota , Nitritos , Esgotos , Nitrificação , Oxigênio , Reatores Biológicos , Nitrogênio/análise , Eliminação de Resíduos Líquidos/métodos
13.
Anal Methods ; 15(18): 2210-2218, 2023 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-37102616

RESUMO

A simple and sensitive method combining solid-phase extraction (SPE) and high-performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the determination of benzo[a]pyrene (BaP) in fish. Loofah sponge (LS) was carbonized and used as an SPE adsorbent. Carbonization decreased the polarity of LS and enhanced its aromaticity. Carbonized loofah sponge (CLS) could capture BaP better through π-π interaction. The carbonization temperature and the SPE conditions were optimized. The linear range of the developed method was within 10-1000 ng g-1 with a satisfactory correlation coefficient (R2) of 0.9999. The limit of detection (LOD) was 2.0 ng g-1, which was below the maximum residue limit (5 µg kg-1) in meat set by the European Union. The method showed good intra-day and inter-day precision with relative standard deviations (RSDs) ranging from 0.4% to 1.7%. Finally, the developed method was applied to the determination of BaP in fish samples. This method is low-cost and environmentally friendly with natural and renewable LS as raw material and it provides an alternative approach for the efficient and simple determination of BaP in aquatic products.


Assuntos
Benzo(a)pireno , Luffa , Animais , Cromatografia Líquida , Cromatografia Líquida de Alta Pressão/métodos , Extração em Fase Sólida/métodos
14.
Adv Mater ; 35(29): e2300621, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37027890

RESUMO

Recently, scalable production of large-area graphene films on metal foils with promising qualities is successfully achieved by eliminating grain boundaries, wrinkles, and adlayers. The transfer of graphene from growth metal substrates onto functional substrates remains one inescapable obstacle on the road to the real commercial applications of chemical vaport deposition (CVD) graphene films. Current transfer methods still require time-consuming chemical reactions, which hinders its mass production, and produces cracks and contamination that strongly impede performance reproducibility. Therefore, graphene transfer techniques with fine intactness and cleanness of transferred graphene, and improved production efficiency would be ideal for the mass production of graphene films on destination substrates. Herein, through the engineering of interfacial forces enabled by sophisticated design of transfer medium, the crack-free and clean transfer of 4-inch-sized graphene wafers onto silicon wafers within only 15 min is realized. The reported transfer method is an important leap over the long-lasting obstacle of the batch-scale graphene transfer without degrading the quality of graphene, bringing the graphene products close to the real applications.

15.
Environ Sci Technol ; 57(16): 6465-6473, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-37040484

RESUMO

Access to safe drinking water is a major public concern in China. A national survey of 57 029 households was conducted to fill major knowledge gaps on drinking water sources, end-of-use treatment methods, and energy used to boil water. Herein, we show that surface water and well water were frequently used by >147 million rural residents living in low-income inland and mountainous areas. Driven by socioeconomic development and government intervention, the level of access to tap water in rural China increased to 70% by 2017. Nevertheless, the rate was considerably lower than that in cities and unevenly distributed across the country. Approximately 90% of drinking water was boiled, an increase from 85% a decade ago. The contribution of electricity, mainly electric kettles, to the boiling of water was 69%. Similar to cooking, living conditions and heating requirements are the main influencing indicators of energy used to boil water. In addition to socioeconomic development, government intervention is a key factor driving the transition to safe water sources, universal access to tap water, and clean energy. Further improvement in drinking water safety in poor and remote rural areas remains challenging, and more intervention and more investment are needed.


Assuntos
Água Potável , Abastecimento de Água , Humanos , China , Cidades , Características da Família , População Rural
17.
Genes Dis ; 10(4): 1675-1686, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36097543

RESUMO

Vaccination by inactivated vaccine is an effective strategy to prevent the COVID-19 pandemic. However, the detailed molecular immune response at single-cell level is poorly understood. In this study, we systematically delineated the landscape of the pre- and post-vaccination single-cell transcriptome, TCR (T cell antigen receptor) and BCR (B cell antigen receptor) expression profile of vaccinated candidates. The bulk TCR sequencing analysis of COVID-19 patients was also performed. Enrichment of a clonal CD8+ T cell cluster expressing specific TCR was identified in both vaccination candidates and COVID-19 patients. These clonal CD8+ T cells showed high expression of cytotoxicity, phagosome and antigen presentation related genes. The cell-cell interaction analysis revealed that monocytes and dendritic cells could interact with these cells and initiate phagocytosis via ICAM1-ITGAM and ITGB2 signaling. Together, our study systematically deciphered the detailed immunological response during SARS-CoV-2 vaccination and infection. It may facilitate understanding the immune response and the T-cell therapy against COVID-19.

18.
Viruses ; 14(9)2022 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-36146860

RESUMO

Persistent infection with high-risk HPV leads to cervical cancers and other anogenital cancers and head and neck carcinomas in both men and women. There is no effective drug fortreating HPV infection and HPV-associated carcinomas, largely due to a lack of models of natural HPV infection and the complexity of the HPV life cycle. There are no available cell lines from vulvar, anal, or penile lesions and cancers in the field. In this study, we established the first human cell line from vulvar intraepithelial neoplasia (VIN) with naturally infected HPV18 by conditional reprogramming (CR) method. Our data demonstrated that VIN cells possessed different biological characteristics and diploid karyotypes from HPV18-positive cancer cells (HeLa). Then, we determined that VIN cells contained episomal HPV18 using approaches including the ratio of HPV E2copy/E7copy, rolling cycle amplification, and sequencing. The VIN cells expressed squamous epithelium-specific markers that are different from HeLa cells, a cervical adenocarcinoma cell line. When cultured under 3D air-liquid interface (ALI) system, we observed the expression of both early and late differentiation markers involucrin and filaggrin. Most importantly, we were able to detect the expression of viral late gene L1 in the cornified layer of ALI 3D culture derived from VIN cells, suggesting quite different HPV genomic status from cancer cells. We also observed progeny viral particles under transmission electron microscopy (TEM) in ALI 3D cultures, confirming the episomal HPV18 genome and active viral life cycle in the new cell line. To our knowledge, this is the first human VIN cell line with naturally infected HPV18 genome and provides a valuable model for HPV biology studies, HPV-associated cancer initiation and progression, and drug-screening platforms.


Assuntos
Carcinoma , Infecções por Papillomavirus , Neoplasias Vulvares , DNA Viral/genética , Feminino , Células HeLa , Humanos , Papillomaviridae/genética , Infecções por Papillomavirus/prevenção & controle , Neoplasias Vulvares/genética , Neoplasias Vulvares/metabolismo , Neoplasias Vulvares/patologia
19.
J Nurs Manag ; 30(7): 3406-3418, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36176010

RESUMO

AIM: The study aimed to explore and compare stress, coping, professional identity and work locus of control of new graduate nurses among Shanghai, Hong Kong and Taipei. BACKGROUND: The transition from a student to a staff nurse role is recognized as a stressful experience and can be a rough journey. Many newly graduated nurses find it challenging to cope with their new roles in their first few months. METHODS: A cross-sectional research was used in the study. This study was completed in Shanghai, Hong Kong and Taipei with newly graduated nurses working in hospitals. A total of 591 graduate nurses who had worked within 1 year in hospitals were recruited using convenient sampling. Data were collected using a structured questionnaire, including demographics, the occupational stress scale, the Chinese trait coping style questionnaire, the nurse professional identity scale and the work locus of control scale (Chinese version). RESULTS: The newly graduated nurses in Shanghai had significantly lower (p < 0.05) work stress score (2.65 ± 0.67) compared with their counterparts in Hong Kong (2.99 ± 0.69) and Taipei (2.94 ± 0.60). Newly graduated nurses in Shanghai tended to choose positive coping to deal with stressful situations, whereas those in Hong Kong would be more likely to adopt negative attitudes (p < 0.05). The newly graduated nurses in Taipei had the lowest level of professional identity (3.25 ± 0.55, p < 0.05), and their work control tended to be external (46.13 ± 6.20). In contrast, those in Shanghai (52.75 ± 6.04) and Hong Kong (59.41 ± 7.29) tended to be controlled internally. CONCLUSIONS: The study findings revealed the differences among newly graduated nurses in Shanghai, Hong Kong and Taipei with their level of stress, coping, professional identity and work locus of control. Proper leadership, mentoring for newly graduated nurses, and emphasis on first aid nursing training, emotional management and management of stress in newly graduated nurse transition programmes were suggested. IMPLICATIONS FOR NURSING MANAGEMENT: By comparing the results in the three regions, we recommend that nursing managers promote the right leadership style. In addition to coaching, nursing managers can assign additional mentors to newly graduated nurses to help them supplement their clinical knowledge and skills with psychological support. These mentors can come from senior nurses or nursing managers working on less demanding tasks. In addition to the existing post transfer training programmes, new graduate nurses should also focus on emergency nursing training, emotional management training and stress management training.


Assuntos
Adaptação Psicológica , Enfermeiras e Enfermeiros , Humanos , Estudos Transversais , Hong Kong , China , Inquéritos e Questionários
20.
Inorg Chem ; 61(29): 11293-11305, 2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35820030

RESUMO

Lu2(1-x)Eu2xO3 nanoscintillators (x = 0.005, 0.01, 0.03, 0.05, 0.07, and 0.10) with red emission were synthesized by a coprecipitation method. It is found that their photo- and radioluminescence intensities increase with increasing Eu3+ concentration until x = 0.05. According to their concentration-dependent luminescence intensity ratios (I610(C2)/I582(S6)), the existing energy transfer from Eu3+(S6) (occupying S6 sites) to Eu3+(C2) (occupying C2 sites) can be confirmed. Based on the spectral data and density functional theory (DFT) calculations, the origin of Lu2O3:Eu3+ persistent luminescence at low concentration might be related to the tunneling processes between Eu3+ (occupying C2 and S6 sites) and oxygen interstitials (Oi×). After dispersing afterglow-suppressed Lu2O3:Eu3+ nanoscintillators into polymethyl methacrylate (PMMA) polymer-acetone solution, flexible PMMA-Lu2O3:Eu3+ composite films with high thermal stability and radiation resistance were fabricated by a doctor blade method. As the flexible composite film was used as an imaging plate, static X-ray images with high spatial resolution (5.5 lp/mm) under an extremely low dose of ∼1.1 µGyair can be acquired. When a watch with a moving second hand was used as an object, the dynamic X-ray imaging can be realized under a dose rate of 55 µGyair·s-1. Our results demonstrate that Lu2O3:Eu3+ nanoscintillators can be regarded as candidate materials for dynamic digital radiographic imaging.


Assuntos
Európio , Polimetil Metacrilato , Transferência de Energia , Luminescência , Raios X
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