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1.
J Med Chem ; 67(8): 6570-6584, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38613773

ABSTRACT

NNRTI is an important component of the highly active antiretroviral therapy (HAART), but the rapid emergence of drug resistance and poor pharmacokinetics limited their clinical application. Herein, a series of novel aryl triazolone dihydropyridines (ATDPs) were designed by structure-guided design with the aim of improving drug resistance profiles and pharmacokinetic profiles. Compound 10n (EC50 = 0.009-17.7 µM) exhibited the most active potency, being superior to or comparable to that of doravirine (DOR) against the whole tested viral panel. Molecular docking was performed to clarify the reason for its higher resistance profiles. Moreover, 10n demonstrated excellent pharmacokinetic profile (T1/2 = 5.09 h, F = 108.96%) compared that of DOR (T1/2 = 4.4 h, F = 57%). Additionally, 10n was also verified to have no in vivo acute or subacute toxicity (LD50 > 2000 mg/kg), suggesting that 10n is worth further investigation as a novel oral NNRTIs for HIV-1 therapy.


Subject(s)
Anti-HIV Agents , Dihydropyridines , HIV-1 , Molecular Docking Simulation , Reverse Transcriptase Inhibitors , Triazoles , HIV-1/drug effects , Triazoles/chemistry , Triazoles/pharmacology , Triazoles/pharmacokinetics , Humans , Anti-HIV Agents/pharmacology , Anti-HIV Agents/chemistry , Anti-HIV Agents/chemical synthesis , Anti-HIV Agents/pharmacokinetics , Reverse Transcriptase Inhibitors/pharmacology , Reverse Transcriptase Inhibitors/chemistry , Reverse Transcriptase Inhibitors/chemical synthesis , Reverse Transcriptase Inhibitors/pharmacokinetics , Dihydropyridines/chemistry , Dihydropyridines/pharmacology , Dihydropyridines/pharmacokinetics , Structure-Activity Relationship , HIV Reverse Transcriptase/antagonists & inhibitors , HIV Reverse Transcriptase/metabolism , Animals , Male , Drug Discovery , Molecular Structure , Mice
2.
J Med Chem ; 67(5): 4234-4249, 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38416116

ABSTRACT

The existing available antipsychotics have failed to manage the cognitive impairment of schizophrenia and induced a number of seriously undesirable effects. Trace amine-associated receptor 1 (TAAR1) has emerged as an ideal target for the design of antischizophrenia drugs, with the ability to mediate multiple psychological functions by sensing endogenous amine-containing metabolites without the side effects of catalepsy. In this work, a series of novel TAAR1 agonists were designed based on the structural analysis of the TAAR1 activation pocket. Among them, 6e displayed a potent TAAR1-Gs/Gq dual-pathway activation property, being different from that of the clinical drug candidate SEP-363856 with only TAAR1-Gs pathway activation. In rodent models, 6e significantly alleviated MK-801-induced schizophrenia-like cognitive phenotypes without inducing catalepsy. Furthermore, 6e·HCl exhibited favorable pharmacokinetic (T1/2 = 2.31 h, F = 39%) and safety properties. All these demonstrated that 6e·HCl may be used as a novel drug candidate for schizophrenia treatment.


Subject(s)
Antipsychotic Agents , Schizophrenia , Humans , Antipsychotic Agents/pharmacology , Antipsychotic Agents/therapeutic use , Catalepsy , Receptors, G-Protein-Coupled/metabolism , Schizophrenia/drug therapy
3.
Sci Data ; 11(1): 169, 2024 Feb 05.
Article in English | MEDLINE | ID: mdl-38316816

ABSTRACT

Compared to commercial chickens, local breeds exhibit better in meat quality and flavour, but the productivity (e.g., growth rate, body weight) of local chicken breeds is rather low. Genetic analysis based on whole-genome sequencing contributes to elucidating the genetic markers or putative candidate genes related to some economic traits, facilitating the improvement of production performance, the acceleration of breeding progress, and the conservation of genetic resources. Here, a total of 209 local chickens from 13 breeds were investigated, and the observation of approximately 91.4% high-quality sequences (Q30 > 90%) and a mapping rate over 99% for each individual indicated good results of this study, as confirmed by a genome coverage of 97.6%. Over 19 million single nucleotide polymorphisms (SNPs) and 1.98 million insertion-deletions (InDels) were identified using the reference genome (GRCg7b), further contributing to the public database. This dataset provides valuable resources for studying genetic diversity and adaptation and for the cultivation of new chicken breeds/lines.


Subject(s)
Chickens , Genome , Animals , Chickens/genetics , China , Genetic Markers , Genetic Variation , Phenotype , Polymorphism, Single Nucleotide , Whole Genome Sequencing
4.
Int J Mol Sci ; 25(2)2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38256234

ABSTRACT

Circadian rhythm disorders pose major risks to human health and animal production activity, and the hypothalamus is the center of circadian rhythm regulation. However, the epigenetic regulation of circadian rhythm based on farm animal models has been poorly investigated. We collected chicken hypothalamus samples at seven time points in one light/dark cycle and performed long noncoding RNA (lncRNA), circular RNA (circRNA), and mRNA sequencing to detect biomarkers associated with circadian rhythm. We enhanced the comprehensive expression profiling of ncRNAs and mRNAs in the hypothalamus and found two gene sets (circadian rhythm and retinal metabolism) associated with the light/dark cycle. Noncoding RNA networks with circadian expression patterns were identified by differential expression and circadian analysis was provided that included 38 lncRNAs, 15 circRNAs, and 200 candidate genes. Three lncRNAs (ENSGALT00000098661, ENSGALT00000100816, and MSTRG.16980.1) and one circRNA (novel_circ_010168) in the ncRNA-mRNA regulatory network were identified as key molecules influencing circadian rhythm by regulating AOX1 in retinal metabolism. These ncRNAs were predicted to be related to pernicious anemia, gonadal, eye disease and other disorders in humans. Together, the findings of this study provide insights into the epigenetic mechanisms of circadian rhythm and reveal AOX1 as a promising target of circadian rhythm regulation.


Subject(s)
RNA, Long Noncoding , Animals , Humans , RNA, Long Noncoding/genetics , Epigenesis, Genetic , RNA, Circular/genetics , Circadian Rhythm/genetics , RNA, Messenger/genetics
5.
Nat Rev Immunol ; 24(1): 18-32, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37402992

ABSTRACT

In vitro 3D models are advanced biological tools that have been established to overcome the shortcomings of oversimplified 2D cultures and mouse models. Various in vitro 3D immuno-oncology models have been developed to mimic and recapitulate the cancer-immunity cycle, evaluate immunotherapy regimens, and explore options for optimizing current immunotherapies, including for individual patient tumours. Here, we review recent developments in this field. We focus, first, on the limitations of existing immunotherapies for solid tumours, secondly, on how in vitro 3D immuno-oncology models are established using various technologies - including scaffolds, organoids, microfluidics and 3D bioprinting - and thirdly, on the applications of these 3D models for comprehending the cancer-immunity cycle as well as for assessing and improving immunotherapies for solid tumours.


Subject(s)
Neoplasms , Animals , Mice , Humans , Neoplasms/therapy , Organoids , Immunotherapy , Disease Models, Animal , Immunity
6.
Clin Transl Gastroenterol ; 15(2): e00625, 2024 02 01.
Article in English | MEDLINE | ID: mdl-37581331

ABSTRACT

INTRODUCTION: To investigate the efficacy and safety of preprocedural simethicone (S) and pronase (P) for optimal mucosal visualization during esophagogastroduodenoscopy with sedation. The effect of postural change combined with premedication on mucosal visibility was also examined. METHODS: The study randomized 496 patients into 8 groups based on the type of premedication provided and whether a postural change occurred. The premedication in the control group was 100 mL of normal saline solution (NS). The remaining 3 intervention groups were administered 100 mL of simethicone alone (S), pronase solution alone (P), and simethicone plus pronase solution (S + P). Each group was classified into subgroups according to whether there was a postural change (PC). The mucosal visibility score (MVS), total mucosal visibility score (TVS), procedure time, water consumption for mucosal cleansing, and proportion of patients with diminutive lesions <5 mm were recorded. RESULTS: The P and S groups had a significantly better TVS than the NS group (11.86 ± 3.36 in group P vs 14.52 ± 2.57 in group NS, P < 0.001; 12.36 ± 2.93 in group S vs 14.52 ± 2.57 in group NS, P = 0.006). The TVS was better in the P group than in the S group (11.86 ± 3.36 vs 12.36 ± 2.93, P = 0.037). The MVS was significantly better in the esophagus and duodenum and worse in the upper and lower gastric body in the S group than in the P group. The P + S group had a significantly better TVS than the P and S groups (9.81 ± 2.90 in group P + S vs 11.86 ± 3.36 in group P and 12.36 ± 2.93 in group S, respectively, P < 0.001),\ and had a reduced amount of flushing water during the procedure (0 [interquartile range [IQR]: 0-33] mL in group P + S vs 40 [IQR: 0-70] mL in group P, P < 0.01; 0 [IQR: 0-33] mL in group P + S vs 50 [IQR: 20-98] mL in group S, P < 0.001). The TVS was significantly better in the P + S + PC group than in the P + S group (8.44 ± 2.10 vs 9.81 ± 2.90, P = 0.003). The MVS was significantly better in the gastric antrum, fundus, and upper and lower gastric body in the P + S + PC group than in the P + S group. There was no significant difference in the detection rate of diminutive lesions among the different groups during an endoscopic examination ( P > 0.05). DISCUSSION: The combination of preprocedural administration with simethicone and pronase achieved superior mucosal visualization compared with saline, simethicone, or pronase alone in patients receiving upper endoscopy. Postural change maneuvers performed before endoscopy further improved the mucosal visibility in most parts of the stomach when used with preprocedural simethicone and pronase.


Subject(s)
Endoscopy, Gastrointestinal , Simethicone , Humans , Pronase , Prospective Studies , Endoscopy, Gastrointestinal/methods , Mucous Membrane , Premedication/methods
7.
Cell ; 186(24): 5347-5362.e24, 2023 11 22.
Article in English | MEDLINE | ID: mdl-37963465

ABSTRACT

Trace amine-associated receptor 1 (TAAR1) senses a spectrum of endogenous amine-containing metabolites (EAMs) to mediate diverse psychological functions and is useful for schizophrenia treatment without the side effects of catalepsy. Here, we systematically profiled the signaling properties of TAAR1 activation and present nine structures of TAAR1-Gs/Gq in complex with EAMs, clinical drugs, and synthetic compounds. These structures not only revealed the primary amine recognition pocket (PARP) harboring the conserved acidic D3.32 for conserved amine recognition and "twin" toggle switch for receptor activation but also elucidated that targeting specific residues in the second binding pocket (SBP) allowed modulation of signaling preference. In addition to traditional drug-induced Gs signaling, Gq activation by EAM or synthetic compounds is beneficial to schizophrenia treatment. Our results provided a structural and signaling framework for molecular recognition by TAAR1, which afforded structural templates and signal clues for TAAR1-targeted candidate compounds design.


Subject(s)
Receptors, G-Protein-Coupled , Signal Transduction , Humans , Amines/metabolism , Receptors, G-Protein-Coupled/metabolism , Schizophrenia/metabolism
8.
Bioorg Med Chem ; 96: 117484, 2023 12 15.
Article in English | MEDLINE | ID: mdl-37976805

ABSTRACT

HIV-1 reverse transcriptase (RT) is considered as one of the most significant targets for the anti-HIV-1 drug design due to their determined mechanism and well-decoded crystal structure. As a part of our continuous efforts towards the development of potent HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) by exploiting the tolerant region I of NNRTIs binding pocket (NNIBP), the miniaturized parallel synthesis via CuAAC click chemistry reaction followed by in situ biological screening have been performed in this work. The in situ enzyme inhibition screening results showed that 14 compounds exhibited higher or equivalent inhibitory activity compared to the lead K-5a2 and ETR. Anti-HIV-1 activity results indicated that C1N51 displayed the most potent activity (EC50 = 0.01-0.26 µM) against wild-type and a panel of NNRTIs-resistant strains. Moreover, the molecular simulation demonstrated that the newly introduced triazole ring could develop new hydrogen bonds with Lys103 and Pro236, which explained the feasibility of introducing triazole in the tolerant region I of the RT binding pocket.


Subject(s)
Anti-HIV Agents , HIV-1 , Reverse Transcriptase Inhibitors/pharmacology , Reverse Transcriptase Inhibitors/chemistry , Triazoles/pharmacology , Triazoles/chemistry , Click Chemistry , Drug Design , Anti-HIV Agents/pharmacology , Anti-HIV Agents/chemistry , HIV Reverse Transcriptase , Heterocyclic Compounds, 1-Ring , Structure-Activity Relationship
9.
PLoS Genet ; 19(11): e1011021, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37917726

ABSTRACT

Small nuclear RNAs (snRNAs) are structural and functional cores of the spliceosome. In metazoan genomes, each snRNA has multiple copies/variants, up to hundreds in mammals. However, the expressions and functions of each copy/variant in one organism have not been systematically studied. Focus on U1 snRNA genes, we investigated all five copies in Drosophila melanogaster using two series of constructed strains. Analyses of transgenic flies that each have a U1 promoter-driven gfp revealed that U1:21D is the major and ubiquitously expressed copy, and the other four copies have specificities in developmental stages and tissues. Mutant strains that each have a precisely deleted copy of U1-gene exhibited various extents of defects in fly morphology or mobility, especially deletion of U1:82Eb. Interestingly, splicing was changed at limited levels in the deletion strains, while large amounts of differentially-expressed genes and alternative polyadenylation events were identified, showing preferences in the down-regulation of genes with 1-2 introns and selection of proximal sites for 3'-end polyadenylation. In vitro assays suggested that Drosophila U1 variants pulled down fewer SmD2 proteins compared to the canonical U1. This study demonstrates that all five U1-genes in Drosophila have physiological functions in development and play regulatory roles in transcription and 3'-end formation.


Subject(s)
Drosophila melanogaster , RNA, Small Nuclear , Animals , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , RNA, Small Nuclear/genetics , RNA, Small Nuclear/metabolism , RNA Splicing/genetics , Drosophila/genetics , Drosophila/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , Mammals/genetics
10.
Bioresour Technol ; 390: 129859, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37832851

ABSTRACT

Improving high-temperature tolerance of microalgae is crucial to enhance the robustness and economy of microalgae industrial production. Herein, a continuous adaptive laboratory evolution (ALE) system was developed to generate the thermotolerant strain of Chlorella sorokiniana. The resulting thermotolerant strain TR42 exhibited excellent cell growth and biomass production at 42 °C, the temperature that the original strain (OS) could not survive. The high-temperature resistant mechanism of TR42 was investigated by integrating the physiology, transcriptome, proteome and metabolome analyses, which involved enhancing antioxidant capacity, maintaining protein homeostasis, remodeling photosynthetic metabolism, and regulating the synthesis of heat-stress related metabolites. The proof-of-concept high-temperature outdoor cultivation demonstrated that TR42 exhibited 1.15- to 5.72-fold increases in biomass production and 1.62- to 7.04-fold increases in lipid productivity compared to those of OS, respectively, which provided a promising platform for microalgae industrial production. Thus, the multi-system thermotolerant mechanism of TR42 offered potential targets for enhancing high-temperature tolerance of microalgae.


Subject(s)
Chlorella , Microalgae , Chlorella/metabolism , Temperature , Multiomics , Microalgae/metabolism , Biomass
11.
J Phys Chem Lett ; 14(28): 6386-6394, 2023 Jul 20.
Article in English | MEDLINE | ID: mdl-37428149

ABSTRACT

Ultraviolet C (UVC) sterilization has the advantages of high efficiency, broad spectrum, and no secondary pollution. However, the emission wavelength of UVC phosphors still suffers from a large deviation from the golden sterilization wavelength of 265 nm and a low luminescence intensity. Herein, we report UVC emission near the golden sterilization wavelength as well as a long afterglow through crystal field engineering, which can lead to 100% sterilization efficiency. Combined with theoretical calculation and experimental studies, substitution of Ca2+ with large-sized Sr2+ could obtain slight expansion and distortion of cationic sites, resulting in a decrease in crystal field intensity and blue shift of Ca1.5Sr0.5Al2SiO7:1%Pr3+, and produce near golden UVC emission. Ca1.5Sr0.5Al2SiO7:1%Pr3+ phosphor can effectively inactivate Staphylococcus aureus within 10 min, showing more efficiency than the traditional mercury lamp. This work provides an effective solution for the design and preparation of UVC phosphors using crystal field engineering toward near golden UVC emission.

12.
Plants (Basel) ; 12(11)2023 May 30.
Article in English | MEDLINE | ID: mdl-37299141

ABSTRACT

Mining salt tolerance genes is significant for breeding high-quality salt-tolerant rice varieties in order to improve the utilization of saline-alkaline land. In this study, 173 rice accessions were measured for their germination potential (GP), germination rate (GR), seedling length (SL), root length (RL), germination potential relative to salt damage rate (GPR), germination rate relative to salt damage rate (GRR), seedling length relative to salt damage rate (SLR), relative salt damage rate at the germination stage (RSD) and comprehensive relative salt damage rate in the early seedling stage (CRS) under normal and salt stress conditions. Genome-wide association analysis was performed with 1,322,884 high-quality SNPs obtained by resequencing. Eight quantitative trait loci (QTLs) related to salt tolerance traits at the germination stage were detected in 2020 and 2021. They were related to the GPR (qGPR2) and SLR (qSLR9), which were newly discovered in this study. Three genes were predicted as salt tolerance candidate genes: LOC_Os02g40664, LOC_Os02g40810, and LOC_Os09g28310. At present, marker-assisted selection (MAS) and gene-edited breeding are becoming more widespread. Our discovery of candidate genes provides a reference for research in this field. The elite alleles identified in this study may provide a molecular basis for cultivating salt-tolerant rice varieties.

13.
Angew Chem Int Ed Engl ; 62(35): e202305186, 2023 Aug 28.
Article in English | MEDLINE | ID: mdl-37157011

ABSTRACT

Ultra-low molecular weight (ULMW) CO2 -polyols with well-defined hydroxyl end groups represent useful soft segments for the preparation of high-performance polyurethane foams. However, owing to the poor proton tolerance of catalysts towards CO2 /epoxide telomerization, it remains challenging to synthesize ULMW yet colorless CO2 -polyols. Herein, we propose an immobilization strategy of constructing supported catalysts by chemical anchoring of aluminum porphyrin on Merrifield resin. The resulting supported catalyst displays both extremely high proton tolerance (≈8000 times the equivalents of metal centers) and independence of cocatalyst, affording CO2 -polyols with ULMW (580 g mol-1 ) and high polymer selectivity (>99 %). Moreover, the ULMW CO2 -polyols with various architectures (tri-, quadra-, and hexa-arm) can be obtained, suggesting the wide proton universality of supported catalysts. Notably, benefiting from the heterogeneous nature of the supported catalyst, colorless products can be facilely achieved by simple filtration. The present strategy provides a platform for the synthesis of colorless ULMW polyols derived from not only CO2 /epoxides, but also lactone, anhydrides etc. or their combinations.

14.
Biofabrication ; 15(3)2023 05 24.
Article in English | MEDLINE | ID: mdl-37130516

ABSTRACT

Recent advances in tumor microenvironment (TME) modeling as well as its applications to cancer therapy has brought various dramatical changes in multiple malignancies management. Understanding the mechanisms of response and resistance to cancer therapy requires a clear elucidation of the intricate interactions between TME cells, the surrounding stroma, and distant affected tissues or organs. To address this demand, various three-dimensional (3D) cell culture techniques have been developed in order to recapitulate and understand cancer biology over the past decade. This review summarizes some saliant progresses inin vitro3D TME modeling, including the cell-based, matrix-based, and vessel-based dynamic 3D modeling techniques and their applications in investigating tumor-stroma interactions and responses to cancer therapies. The review also discusses the limitations of current TME modeling approaches and proposes some new thoughts on the construction of more clinically relevant models.


Subject(s)
Neoplasms , Tumor Microenvironment , Humans , Neoplasms/pathology , Cell Culture Techniques/methods , Models, Biological
15.
J Phys Chem Lett ; 14(16): 3818-3825, 2023 Apr 27.
Article in English | MEDLINE | ID: mdl-37058299

ABSTRACT

Bi4Ge3O12 (BGO) is a traditional scintillator, widely used in high-energy physics and nuclear medicine. However, it not only suffers from low scintillation intensity but also tends to be damaged by high-energy rays. Herein, we prepare pure-phase BGO materials enriched with Bi vacancies by rationally reduced Bi content, showing significantly enhanced luminescence intensity and irradiation resistance ability. The optimized Bi3.6Ge3O12 shows 178% of luminescence intensity compared to BGO. After 50 h of ultraviolet irradiation, Bi3.6Ge3O12 possesses ∼80% of original luminescence intensity, much superior to the 60% for BGO. The existence of the Bi vacancy is identified by advanced experimental and theoretical studies. The mechanism studies show the Bi vacancies could cause the symmetry destruction of the local field around the Bi3+ ion. It enhances scintillation luminescence by increasing the probability of radiative transition while resisting nonradiative relaxation caused by irradiation damage. This study initiates vacancy-induced performance enhancement for inorganic scintillators.

16.
J Agric Food Chem ; 71(11): 4615-4624, 2023 Mar 22.
Article in English | MEDLINE | ID: mdl-36945879

ABSTRACT

Phaeosphaeria sp., a lichen-associated fungus, produced six skeletally new dimeric spiciferones (1-6) and four known metabolites (7-10). The new structures were elucidated by spectroscopic analysis, and their absolute configurations were determined by electronic circular dichroism calculations. Compounds 1 and 3-6 represent the first examples of ethylidene-bridged dimers from the building blocks 4H-chromene-4,7(8H)-dione and α-pyrone, and 2 is a unique homodimer of spiciferone. Compounds 1, 2, and 5-9 significantly inhibited the growth of weed-like dicot Arabidopsis thaliana at 100.0 µM. Notably, 8 showed the strongest inhibitory activity against the fresh weight and root elongation of A. thaliana with the IC50 values of 32.04 and 26.78 µM, respectively, whereas 1, 8, and 9 stimulated the growth of A. thaliana at lower concentrations. Meanwhile, compounds 2 and 6 exhibited weak inhibitory effects on the root elongation of monocot rice, while 1 and 8 exhibited growth-promoting effects on the shoot and root elongation of rice in a roughly dose-dependent manner.


Subject(s)
Arabidopsis , Ascomycota , Pyrones/chemistry , Benzopyrans/pharmacology , Benzopyrans/metabolism , Plant Growth Regulators/metabolism , Ascomycota/chemistry , Molecular Structure
17.
Int J Mol Sci ; 24(2)2023 Jan 07.
Article in English | MEDLINE | ID: mdl-36674730

ABSTRACT

This study presents proof of concept for designing a novel HIV-1 covalent inhibitor targeting the highly conserved Tyr318 in the HIV-1 non-nucleoside reverse transcriptase inhibitors binding pocket to improve the drug resistance profiles. The target inhibitor ZA-2 with a fluorosulfate warhead in the structure was found to be a potent inhibitor (EC50 = 11-246 nM) against HIV-1 IIIB and a panel of NNRTIs-resistant strains, being far superior to those of NVP and EFV. Moreover, ZA-2 was demonstrated with lower cytotoxicity (CC50 = 125 µM). In the reverse transcriptase inhibitory assay, ZA-2 exhibited an IC50 value of 0.057 µM with the ELISA method, and the MALDI-TOF MS data demonstrated the covalent binding mode of ZA-2 with the enzyme. Additionally, the molecular simulations have also demonstrated that compounds can form covalent binding to the Tyr318.


Subject(s)
Anti-HIV Agents , HIV-1 , Reverse Transcriptase Inhibitors/pharmacology , Reverse Transcriptase Inhibitors/chemistry , HIV-1/metabolism , Anti-HIV Agents/pharmacology , Anti-HIV Agents/chemistry , HIV Reverse Transcriptase/metabolism , Drug Design , Structure-Activity Relationship
19.
Materials (Basel) ; 16(2)2023 Jan 04.
Article in English | MEDLINE | ID: mdl-36676225

ABSTRACT

Eu3+-doped GdAlO3 (Eu:GAP) and Gd0.5La0.5AlO3 (Eu:GLAP) perovskite single crystals were successfully grown using the optical floating zone (OFZ) method. The microstructure, optical, photoluminescence (PL) and radioluminescence (under X-ray excitation, XEL) were investigated. Under the PL excitation of 275 nm, obvious emission bands peaking at 556 nm, 592 nm, 617 nm, 625 nm, 655 nm, and 706 nm were demonstrated, which correspond to the 5D0 → 7Fj (j = 0-4) transitions of Eu3+. The grown Eu:GAP single crystal showed a stronger PL intensity compared with that of Eu:GLAP in the red light region. After annealing at 1000 °C for 4 h in weak reductive atmosphere (Ar + 5% H2), a slight redshift and dramatic enhancement of PL and XEL intensity occurred. In addition, Eu:GLAP show a more intense XEL emission than that of Eu:GAP. Considering their different densities, these two kinds of red luminescence phosphors are proposed to be promising in a wide field of X-ray imaging, warm white, or plant lighting, respectively.

20.
Materials (Basel) ; 15(24)2022 Dec 17.
Article in English | MEDLINE | ID: mdl-36556830

ABSTRACT

Ce3+, Pr3+ co-doped Lu3Al5O12 (Ce, Pr:LuAG) single crystals and ceramics were prepared using the optical floating zone (OFZ) and reactive vacuum sintering methods, respectively. The microstructure, photo- (λex = 450 nm), and radio-luminescence (under X-ray excitation) performance, as well as scintillation light yield (LY, under γ-ray, 137Cs source) of both materials, were investigated and compared. Ce, Pr:LuAG ceramics had an in-line transmittance of approximately 20% in the visible light range, while the analogous crystals were more transparent (~65%). The X-ray excited luminescent (XEL) spectra showed the characteristic Ce 3+ and Pr3+ emissions located at 310 nm, 380 nm, and 510 nm. The highest LY of the Ce, Pr:LuAG ceramics reached 34,112 pho/MeV at 2 µs time gate, which is higher than that of a single crystal. The ratio of LY values (LY2/LY0.75) between shaping times of 0.75 µs and 2 µs indicated a faster scintillation decay of ceramics regarding single crystals. It was ascribed to the lower effective concentration of luminescent activators in single crystals because of the coefficient segregation effect.

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