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1.
Brief Bioinform ; 25(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38349061

RESUMO

Extrachromosomal circular DNA (eccDNA) is currently attracting considerable attention from researchers due to its significant impact on tumor biogenesis. High-throughput sequencing (HTS) methods for eccDNA identification are continually evolving. However, an efficient pipeline for the integrative and comprehensive analysis of eccDNA obtained from HTS data is still lacking. Here, we introduce eccDNA-pipe, an accessible software package that offers a user-friendly pipeline for conducting eccDNA analysis starting from raw sequencing data. This dataset includes data from various sequencing techniques such as whole-genome sequencing (WGS), Circle-seq and Circulome-seq, obtained through short-read sequencing or long-read sequencing. eccDNA-pipe presents a comprehensive solution for both upstream and downstream analysis, encompassing quality control and eccDNA identification in upstream analysis and downstream tasks such as eccDNA length distribution analysis, differential analysis of genes enriched with eccDNA and visualization of eccDNA structures. Notably, eccDNA-pipe automatically generates high-quality publication-ready plots. In summary, eccDNA-pipe provides a comprehensive and user-friendly pipeline for customized analysis of eccDNA research.


Assuntos
DNA Circular , Neoplasias , Humanos , DNA Circular/genética , DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala , Sequenciamento Completo do Genoma
2.
Nat Methods ; 19(6): 662-670, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35577954

RESUMO

Spatial transcriptomics approaches have substantially advanced our capacity to detect the spatial distribution of RNA transcripts in tissues, yet it remains challenging to characterize whole-transcriptome-level data for single cells in space. Addressing this need, researchers have developed integration methods to combine spatial transcriptomic data with single-cell RNA-seq data to predict the spatial distribution of undetected transcripts and/or perform cell type deconvolution of spots in histological sections. However, to date, no independent studies have comparatively analyzed these integration methods to benchmark their performance. Here we present benchmarking of 16 integration methods using 45 paired datasets (comprising both spatial transcriptomics and scRNA-seq data) and 32 simulated datasets. We found that Tangram, gimVI, and SpaGE outperformed other integration methods for predicting the spatial distribution of RNA transcripts, whereas Cell2location, SpatialDWLS, and RCTD are the top-performing methods for the cell type deconvolution of spots. We provide a benchmark pipeline to help researchers select optimal integration methods to process their datasets.


Assuntos
Benchmarking , Transcriptoma , RNA , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos
3.
Genomics ; 115(3): 110593, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36868327

RESUMO

OBJECTIVES: We aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m6A-MYC axis. METHODS: Expression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted. RESULTS: LINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice. CONCLUSIONS: LINC00858 modulated MYC m6A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , RNA Longo não Codificante , Animais , Camundongos , Carcinoma de Células Escamosas do Esôfago/genética , Neoplasias Esofágicas/patologia , RNA Longo não Codificante/genética , Camundongos Nus , Linhagem Celular Tumoral , Dioxigenase FTO Dependente de alfa-Cetoglutarato
4.
Langmuir ; 39(17): 6078-6087, 2023 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-37084417

RESUMO

Graphitized carbonitride (g-C3N4) is widely used in CO2 reduction, hydrogen production, and degradation of toxic chemical dyes and antibiotics. It is a kind of photocatalytic material with excellent performance, and it has the advantages of being safe and nontoxic, having a suitable band gap (2.7 eV), and having a simple preparation and high stability, but because of its fast optical recombination speed and low visible light overutilization, the multifunctional application of g-C3N4 is seriously hindered. Compared with pure g-C3N4, MWCNTs/g-C3N4 have a red-shift in the visible range and a strong absorption in the visible region. Melamine and carboxylated multiwalled carbon nanotubes were used as raw materials to successfully prepare CMWCNT modified g-C3N4 doped with P, Cl by a high temperature calcination method. The effect of the addition amount of P, Cl on the photocatalytic performance of modified g-C3N4 was studied. The experimental results show that the multiwalled carbon nanotubes can accelerate the electron migration, and the doping of P, Cl elements can change the energy band structure of g-C3N4 and reduce the band gap. Through fluorescence analysis and photocurrent analysis, it is known that the incorporation of P, Cl reduces the recombination efficiency of photogenerated electron-hole pairs. In order to explore the application in the degradation of chemical dyes, the photocatalytic degradation efficiency of RhB under visible light was studied. The photocatalytic performance of the samples was evaluated by photodecomposition of aquatic hydrogen. The results showed that when the amount of ammonium dihydrogen phosphate was 10 wt %, the photocatalytic degradation efficiency was the highest, which was 21.13 times higher than that of g-C3N4.

5.
Luminescence ; 38(2): 208-215, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36634157

RESUMO

This paper reports a sequence of a Ca3 YAl3 B4 O15 :xEu3+ red phosphor prepared using a high-temperature solid-state reaction. At the excitation of 396 nm, the samples emitted intense red emission centred at ~623 nm, which could be attributed to the 5 D0 →7 F2 transition of the Eu3+ ion. The results showed that the optimum Eu3+ doping concentration of Ca3 YAl3 B4 O15 :Eu3+ phosphor was x = 80 mol%, and the concentration quenching mechanism of Ca3 YAl3 B4 O15 :Eu3+ red phosphor belonged to the exchange coupling between Eu3+ ions. The Commission Internationale de l'éclairage (CIE) coordinates and colour purity of Ca3 Y0.2 Al3 B4 O15 :0.8Eu3+ were calculated as (0.6375, 0.3476) and 95.5%, respectively. Moreover, the red emission of the obtained phosphor Ca3 YAl3 B4 O15 :0.8Eu3+ exhibited a low thermal quenching behaviour with an intensity retention rate of 92.85% at 150°C. The above results manifest that the Eu3+ -activated Ca3 YAl3 B4 O15 phosphor is predicted to be a promising red luminescent component for white light-emitting diodes.


Assuntos
Substâncias Luminescentes , Európio , Fósforo , Luminescência , Sorbitol
6.
Chemistry ; 28(31): e202104523, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35224788

RESUMO

Novel and stringent automotive exhaust gas emissions standards are urgently needed to counter the problems posed by the worsening global climate and environment. However, the traditional cordierite-based honeycomb ceramics substrates with ultimate pore density have seriously restricted the establishment of new emission standards. Herein, we introduce a novel robust substrate with tailored volume-specific surface area and low heat capacity. This substrate employs the synergy of high-strength ceramic fibers and ultrathin TiO2 nanosheets. The micro-sized fibers provide support to ensure structural strength during the catalytic reaction, while the nanosheets play the dual role of connecting the fibers and providing a high surface area for catalyst immobilization. The new three-dimensional (3D) microarchitecture exhibits a high volume-specific surface area of 3.59×104  cm2 /cm3 , a compressive strength of 2.01 MPa, and remarkable stability after high-speed air erosion at 800 °C. The honeycomb-like structure exhibit low resistance to gas flow. Furthermore, after loading with Pt and Pd nanoparticles, the composite 3D microarchitecture delivered an excellent catalytic performance and prominent structural stability, with a super low light-off temperature of 150 °C. The outstanding mechanical and thermal stability and the high surface area and light-off temperature of the new substrate indicate its potential for use as a highly efficient catalytic carrier to meet the next-generation auto emissions standards.

7.
Chemistry ; 28(11): e202102787, 2022 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-34961998

RESUMO

Silicoaluminophosphate zeolite (SAPO-34) has been attracting increasing attention due to its excellent form selection and controllability in the chemical industry, as well as being one of the best industrial catalysts for methanol-to-olefin (MTO) reaction conversion. However, as a microporous molecular sieve, SAPO-34 easily generates carbon deposition and rapidly becomes inactivated. Therefore, it is necessary to reduce the crystal size of the zeolite or to introduce secondary macropores into the zeolite crystal to form a hierarchical structure in order to improve the catalytic effect. In this review, the synthesis methods of conventional SAPO-34 molecular sieves, hierarchical SAPO-34 molecular sieves and nanosized SAPO-34 molecular sieves are introduced, and the properties of the synthesized SAPO-34 molecular sieves are described, including the phase, morphology, pore structure, acid source, and catalytic performance, in particular with respect to the synthesis of hierarchical SAPO-34 molecular sieves. We hope that the review can provide guidance to the preparation of the SAPO-34 catalysts, and stimulate the future development of high-performance hierarchical SAPO-34 catalysts to meet the growing demands of the material and chemical industries.

8.
Molecules ; 27(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35897927

RESUMO

The high price of noble metal resources limits its commercial application and stimulates the potential for developing new catalysts that can replace noble metal catalysts. Tungsten-based catalysts have become the most important substitutes for noble metal catalysts because of their rich resources, friendly environment, rich valence and better adsorption enthalpy. However, some challenges still hinder the development of tungsten-based catalysts, such as limited catalytic activity, instability, difficult recovery, and so on. At present, the focus of tungsten-based catalyst research is to develop a satisfactory material with high catalytic performance, excellent stability and green environmental protection, mainly including tungsten atomic catalysts, tungsten metal nanocatalysts, tungsten-based compound nanocatalysts, and so on. In this work, we first present the research status of these tungsten-based catalysts with different sizes, existing forms, and chemical compositions, and further provide a basis for future perspectives on tungsten-based catalysts.


Assuntos
Metais , Tungstênio , Catálise , Tungstênio/química
9.
Clin Gastroenterol Hepatol ; 19(3): 597-603, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32553907

RESUMO

BACKGROUND & AIMS: Coronavirus disease 2019 (COVID-19) is a major global health threat. We aimed to describe the characteristics of liver function in patients with SARS-CoV-2 and chronic hepatitis B virus (HBV) coinfection. METHODS: We enrolled all adult patients with SARS-CoV-2 and chronic HBV coinfection admitted to Tongji Hospital from February 1 to February 29, 2020. Data of demographic, clinical characteristics, laboratory tests, treatments, and clinical outcomes were collected. The characteristics of liver function and its association with the severity and prognosis of disease were described. RESULTS: Of the 105 patients with SARS-CoV-2 and chronic HBV coinfection, elevated levels of liver test were observed in several patients at admission, including elevated levels of alanine aminotransferase (22, 20.95%), aspartate aminotransferase (29, 27.62%), total bilirubin (7, 6.67%), gamma-glutamyl transferase (7, 6.67%), and alkaline phosphatase (1, 0.95%). The levels of the indicators mentioned above increased substantially during hospitalization (all P < .05). Fourteen (13.33%) patients developed liver injury. Most of them (10, 71.43%) recovered after 8 (range 6-21) days. Notably the other, 4 (28.57%) patients rapidly progressed to acute-on-chronic liver failure. The proportion of severe COVID-19 was higher in patients with liver injury (P = .042). Complications including acute-on-chronic liver failure, acute cardiac injury and shock happened more frequently in patients with liver injury (all P < .05). The mortality was higher in individuals with liver injury (28.57% vs 3.30%, P = .004). CONCLUSION: Liver injury in patients with SARS-CoV-2 and chronic HBV coinfection was associated with severity and poor prognosis of disease. During the treatment of COVID-19 in chronic HBV-infected patients, liver function should be taken seriously and evaluated frequently.


Assuntos
COVID-19/complicações , Coinfecção/complicações , Hepatite B Crônica/complicações , Fígado/fisiopatologia , Adulto , Idoso , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Bilirrubina/sangue , COVID-19/sangue , COVID-19/mortalidade , China , Coinfecção/sangue , Coinfecção/mortalidade , Feminino , Hepatite B Crônica/sangue , Hepatite B Crônica/mortalidade , Hospitalização , Humanos , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida
10.
J Clin Lab Anal ; 35(12): e24053, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34674393

RESUMO

BACKGROUND: Sepsis-associated thrombocytopenia (SAT) is common in critical patients and results in the elevation of mortality. Red cell distribution width (RDW) can reflect body response to inflammation and oxidative stress. We try to investigate the relationship between the RDW and the prognosis of patients with SAT through machine learning. METHODS: 809 patients were retrospectively analyzed from the Medical Information Mart for Intensive Care III (MIMIC-III) database. The eXtreme Gradient Boosting (XGBoost) and SHapley Additive exPlanations (SHAP) were used to analyze the impact of each feature. Logistic regression analysis, propensity score matching (PSM), receiver-operating characteristics (ROC) curve analysis, and the Kaplan-Meier method were used for data processing. RESULTS: The patients with thrombocytopenia had higher 28-day mortality (48.2%). Machine learning indicated that RDW was the second most important in predicting 28-day mortality. The RDW was significantly increased in non-survivors by logistic regression and PSM. ROC curve shows that RDW has moderate predictive power for 28-day mortality. The patients with RDW>16.05 exhibited higher mortality through Kaplan-Meier analysis. CONCLUSIONS: Interpretable machine learning can be applied in clinical research. Elevated RDW is not only common in patients with SAT but is also associated with a poor prognosis.


Assuntos
Índices de Eritrócitos , Aprendizado de Máquina , Choque Séptico/sangue , Choque Séptico/mortalidade , Trombocitopenia/etiologia , Idoso , Comorbidade , Feminino , Mortalidade Hospitalar , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Prognóstico , Pontuação de Propensão , Estudos Retrospectivos , Choque Séptico/epidemiologia , Trombocitopenia/mortalidade
11.
Nano Lett ; 20(7): 4993-5000, 2020 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-32496781

RESUMO

Advanced filter materials with high efficiency, low-pressure drop, and high-temperature resistance are urgently needed in the field of high-temperature gas filtration. Here, an Al2O3-stabilized ZrO2 (ASZ) submicron fiber air filter paper with excellent flexibility and thermal stability (up to 1100 °C) is developed using a cost-effective, scalable solution blow spinning method and subsequent calcination. The ASZ papers demonstrate excellent flexibility and foldability, which can be attributed to the tetragonal phase and small crystallite size of the ASZ fibers due to the presence of Al2O3. In addition, the ASZ papers with an areal density of 56 mg cm-2 show a high filtration efficiency (99.56%) and a low-pressure drop (108 Pa) for 15-615 nm NaCl particles at an airflow velocity of 5.4 cm s-1. We envision that the foldable all-ceramic air filter material will provide a solution for the removal of particulate matter from the high-temperature exhaust gases.

12.
Molecules ; 26(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071526

RESUMO

Developing a porous separation membrane that can efficiently separate oil-water emulsions still represents a challenge. In this study, nanofiber membranes with polydopamine clusters polymerized and embedded on the surface were successfully constructed using a solution blow-spinning process. The hierarchical surface structure enhanced the selective wettability, superhydrophilicity in air (≈0°), and underwater oleophobicity (≈160.2°) of the membrane. This membrane can effectively separate oil-water emulsions, achieving an excellent permeation flux (1552 Lm-2 h-1) and high separation efficiency (~99.86%) while operating only under the force of gravity. When the external driving pressure was increased to 20 kPa, the separation efficiency hardly changed (99.81%). However, the permeation flux significantly increased to 5894 Lm-2 h-1. These results show that the as-prepared polydopamine nanocluster-embedded nanofiber membrane has an excellent potential for oily wastewater treatment applications.

13.
Crit Care Med ; 48(8): e657-e665, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32697506

RESUMO

OBJECTIVES: Coronavirus disease 2019 has emerged as a major global health threat with a great number of deaths in China. We aimed to assess the association between Acute Physiology and Chronic Health Evaluation II score and hospital mortality in patients with coronavirus disease 2019, and to compare the predictive ability of Acute Physiology and Chronic Health Evaluation II score, with Sequential Organ Failure Assessment score and Confusion, Urea, Respiratory rate, Blood pressure, Age 65 (CURB65) score. DESIGN: Retrospective observational cohort. SETTING: Tongji Hospital in Wuhan, China. SUBJECTS: Confirmed patients with coronavirus disease 2019 hospitalized in the ICU of Tongji hospital from January 10, 2020, to February 10, 2020. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 178 potentially eligible patients with symptoms of coronavirus disease 2019, 23 patients (12.92%) were diagnosed as suspected cases, and one patient (0.56%) suffered from cardiac arrest immediately after admission. Ultimately, 154 patients were enrolled in the analysis and 52 patients (33.77%) died. Mean Acute Physiology and Chronic Health Evaluation II score (23.23 ± 6.05) was much higher in deaths compared with the mean Acute Physiology and Chronic Health Evaluation II score of 10.87 ± 4.40 in survivors (p < 0.001). Acute Physiology and Chronic Health Evaluation II score was independently associated with hospital mortality (adjusted hazard ratio, 1.07; 95% CI, 1.01-1.13). In predicting hospital mortality, Acute Physiology and Chronic Health Evaluation II score demonstrated better discriminative ability (area under the curve, 0.966; 95% CI, 0.942-0.990) than Sequential Organ Failure Assessment score (area under the curve, 0.867; 95% CI, 0.808-0.926) and CURB65 score (area under the curve, 0.844; 95% CI, 0.784-0.905). Based on the cut-off value of 17, Acute Physiology and Chronic Health Evaluation II score could predict the death of patients with coronavirus disease 2019 with a sensitivity of 96.15% and a specificity of 86.27%. Kaplan-Meier analysis showed that the survivor probability of patients with coronavirus disease 2019 with Acute Physiology and Chronic Health Evaluation II score less than 17 was notably higher than that of patients with Acute Physiology and Chronic Health Evaluation II score greater than or equal to 17 (p < 0.001). CONCLUSIONS: Acute Physiology and Chronic Health Evaluation II score was an effective clinical tool to predict hospital mortality in patients with coronavirus disease 2019 compared with Sequential Organ Failure Assessment score and CURB65 score. Acute Physiology and Chronic Health Evaluation II score greater than or equal to 17 serves as an early warning indicator of death and may provide guidance to make further clinical decisions.


Assuntos
Causas de Morte , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Mortalidade Hospitalar , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Síndrome Respiratória Aguda Grave/mortalidade , APACHE , Adulto , Idoso , COVID-19 , Causalidade , China/epidemiologia , Infecções por Coronavirus/terapia , Feminino , Hospitalização/estatística & dados numéricos , Hospitais Urbanos , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Escores de Disfunção Orgânica , Pandemias , Pneumonia Viral/terapia , Valor Preditivo dos Testes , Modelos de Riscos Proporcionais , Curva ROC , Estudos Retrospectivos , Síndrome Respiratória Aguda Grave/diagnóstico , Síndrome Respiratória Aguda Grave/terapia , Sobreviventes/estatística & dados numéricos
14.
Crit Care ; 24(1): 219, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32410714

RESUMO

BACKGROUND: A COVID-19 outbreak started in Wuhan, China, last December and now has become a global pandemic. The clinical information in caring of critically ill patients with COVID-19 needs to be shared timely, especially under the situations that there is still a largely ongoing spread of COVID-19 in many countries. METHODS: A multicenter prospective observational study investigated all the COVID-19 patients received in 19 ICUs of 16 hospitals in Wuhan, China, over 24 h between 8 AM February 2h and 8 AM February 27, 2020. The demographic information, clinical characteristics, vital signs, complications, laboratory values, and clinical managements of the patients were studied. RESULTS: A total of 226 patients were included. Their median (interquartile range, IQR) age was 64 (57-70) years, and 139 (61.5%) patients were male. The duration from the date of ICU admission to the study date was 11 (5-17) days, and the duration from onset of symptoms to the study date was 31 (24-36) days. Among all the patients, 155 (68.6%) had at least one coexisting disease, and their sequential organ failure assessment score was 4 (2-8). Organ function damages were found in most of the patients: ARDS in 161 (71.2%) patients, septic shock in 34 (15.0%) patients, acute kidney injury occurred in 57 (25.2%) patients, cardiac injury in 61 (27.0%) patients, and lymphocytopenia in 160 (70.8%) patients. Of all the studied patients, 85 (37.6%) received invasive mechanical ventilation, including 14 (6.2%) treated with extracorporeal membrane oxygenation (ECMO) at the same time, 20 (8.8%) received noninvasive mechanical ventilation, and 24 (10.6%) received continuous renal replacement therapy. By April 9, 2020, 87 (38.5%) patients were deceased and 15 (6.7%) were still in the hospital. CONCLUSIONS: Critically ill patients with COVID-19 are associated with a higher risk of severe complications and need to receive an intensive level of treatments. COVID-19 poses a great strain on critical care resources in hospitals. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2000030164. Registered on February 24, 2020, http://www.chictr.org.cn/edit.aspx?pid=49983&htm=4.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/terapia , Cuidados Críticos , Surtos de Doenças , Unidades de Terapia Intensiva , Pneumonia Viral/epidemiologia , Pneumonia Viral/terapia , Idoso , COVID-19 , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Prospectivos , Resultado do Tratamento
15.
Molecules ; 25(3)2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-32012682

RESUMO

The fabrication and luminescent performance of novel phosphors Na2YMg2V3O12:Dy3+ were investigated by a conventional solid-state reaction method. Under near-UV light, the Na2YMg2V3O12 host self-activated and released a broad emission band (400-700 nm, with a peak at 524 nm) ascribable to charge transfer in the (VO4)3- groups. Meanwhile, the Na2YMg2V3O12:Dy3+ phosphors emitted bright yellow light within both the broad emission band of the (VO4)3- groups and the sharp peaks of the Dy3+ ions at 490, 582, and 663 nm at a quenching concentration of 0.03 mol. The emission of the as-prepared Na2YMg2V3O12:Dy3+ phosphors remained stable at high temperatures. The obtained phosphors, commercial Y2O3:Eu3+ red phosphors, and BaMgAl10O17:Eu2+ blue phosphors were packed into a white light-emitting diode (WLED) device with a near-UV chip. The designed WLED emitted bright white light with good chromaticity coordinates (0.331, 0.361), satisfactory color rendering index (80.2), and proper correlation to a color temperature (7364 K). These results indicate the potential utility of Na2YMg2V3O12:Dy3+ phosphor as a yellow-emitting phosphor in solid-state illumination.


Assuntos
Disprósio/química , Luminescência , Substâncias Luminescentes/química , Magnésio/química , Óxidos/química , Sódio/química , Vanádio/química
16.
Molecules ; 24(7)2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-30987075

RESUMO

The development of white-light-emitting diodes (w-LEDs) makes it meaningful to develop novel high-performance phosphors excited by blue light. Herein, BiOCl:Pr3+ green-yellow phosphors were prepared via a high-temperature solid-state reaction method. The crystal structure, luminescent properties, lifetime, thermal quenching behavior, and quantum yield were studied in detail. The BiOCl:Pr3+ phosphors presented several emission peaks located in green and red regions, under excitation at 453 nm. The CIE coordinates could be tuned along with the changed doping concentration with fair luminescence efficiency. The results also indicated that the optimized doping concentration of Pr3+ ions was at x = 0.0075 because of the concentration quenching behavior resulting from an intense exchange effect. When the temperature reached 150 °C, the intensity of the emission peak at 495 nm could remain at 78% of that at room temperature. The activation energy of 0.20 eV also confirmed that the BiOCl:Pr3+ phosphor exhibited good thermal stability. All these results indicate that the prepared products have potential to be used as a high-performance green-yellow-light-emitting phosphor for blue-light-based w-LEDs.


Assuntos
Luminescência , Substâncias Luminescentes/química , Substâncias Luminescentes/síntese química , Modelos Moleculares , Termodinâmica , Difração de Raios X
17.
Small ; 14(19): e1800258, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29655197

RESUMO

Particulate matter (PM) is a major air pollutant in many regions, jeopardizing ecosystems and public health. Filtration at pollutant source is one of the most important ways to protect the environment, however, considering the high-temperature exhaust gas emissions, effective removal of PM and related pollutants from their sources remains a major challenge. In this study, a resilient, heat-resisting, and high-efficiency PM filter based on yttria-stabilized ZrO2 (YSZ) nanofiber sponge produced with a scalable solution blow spinning process is reported. The porous 3D sponge composed of YSZ nanofibers is lightweight (density of 20 mg cm-3 ) and resilient at both room temperature and high temperatures. At room-temperature conditions, the YSZ nanofiber sponge exhibits 99.4% filtration efficiency for aerosol particles with size in the range of 20-600 nm, associated with a low pressure drop of only 57 Pa under an airflow velocity of 4.8 cm s-1 . At a high temperature of 750 °C, the ceramic sponge maintains a high filtration efficiency of 99.97% for PM0.3-2.5 under a high airflow velocity of 10 cm s-1 . A practical vehicle exhaust filter to capture particles with filtration efficiency of >98.3% is also assembled. Hence, the YSZ nanofiber sponge has enormous potential to be applied in industry.

18.
Nano Lett ; 17(3): 1883-1891, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28165744

RESUMO

Ultrathin metal fibers can serve as highly conducting and flexible current and heat transport channels, which are essential for numerous applications ranging from flexible electronics to energy conversion. Although industrial production of metal fibers with diameters of down to 2 µm is feasible, continuous production of high-quality and low-cost nanoscale metal wires is still challenging. Herein, we report the continuous draw spinning of highly conductive silver submicron fibers with the minimum diameter of ∼200 nm and length of more than kilometers. We obtained individual AgNO3/polymer fibers by continuous drawing from an aqueous solution at a speed of up to 8 m/s. With subsequent heat treatment, freestanding Ag submicron fibers with high mechanical flexibility and electric conductivity have been obtained. Woven mats of aligned Ag submicron fibers were used as transparent electrodes with high flexibility and high performance with sheet resistance of 7 Ω sq-1 at a transparency of 96%. Continuous draw spinning opened new avenues for scalable, flexible, and ultralow-cost fabrication of extra-long conductive ultrathin metal fibers.

19.
Angew Chem Int Ed Engl ; 56(14): 3886-3891, 2017 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-28244628

RESUMO

Aluminum-nitrogen six-fold octahedral coordination, [AlN6 ], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si4-x Alx )N7 Oδ (Ln=La, Sm), the first inorganic compounds with [AlN6 ] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P63 mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagomé layers of [SiN4 ] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN6 ] coordination. These compounds are the first examples of the "33-114" sub-type in the "114" family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified.

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