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1.
ACS Nano ; 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32356968

RESUMO

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have attracted intensive interest due to the direct-band-gap transition in the monolayer form, positioning them as potential next-generation materials for optoelectronic or photonic devices. However, the band-nested suppression of the recombination efficiency at higher excitation energies limits the ability to locally control and manipulate the photoluminescence of WS2 for multifunctional applications. In this work, we exploit an energy transfer method to modulate the fluorescence properties of TMDs under a larger excitation range spanning from UV to visible light. Self-assembled lanthanide (Ln)/TMD hybrids have been designed based on a low-cost and highly efficient solution-processed approach. The emission energy from Ln3+ sources can be effectively transferred to the TMD monolayers under low power exposure (0.13 mW) at room temperature, activating the characteristic monolayer fluorescence in place of Ln3+ emission signatures. The Ln/TMDs photonics can potentially tune the excitation of TMDs to provide variable yet controllable emissions. This provides a solution to the suppression of direct exciton recombination in monolayer TMDs at the band nesting resonant energy region. Our work on such Ln/TMD systems would overcome the limited excitation energy range in TMDs and extend their functionalities for optoelectronic or photonic applications.

3.
Biochem Pharmacol ; 177: 113951, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32251672

RESUMO

Dipeptidyl peptidase-4 (DPP4) is elevated in numerous cardiovascular pathological processes and DPP4 inhibition is associated with reduced inflammation and oxidative stress. The aim of this study was to examine the role of DPP4 in endothelial senescence. Sprague-Dawley rats (24 months) were orally administrated saxagliptin (10 mg·kg-1·d-1), a DPP4 inhibitor, for 12 weeks in drinking water. Body weight, heart rate, blood glucose, and blood pressure were measured and vascular histological experiments were performed. In vitro studies were performed using H2O2-induced senescent human umbilical vein endothelial cells. Both in vivo and in vitro studies confirmed the elevation of DPP4 in senescent vascular endothelium, and inhibition or knockdown of DPP4 ameliorated endothelial senescence. In addition, DPP4 inhibition or silencing reduced endothelial oxidative stress levels in aging vasculature and senescent endothelial cells. Moreover, DPP4 inhibition or knockdown normalized the expression and phosphorylation of AMP-activated protein kinase-α (AMPKα) and sirtuin 1 (SIRT1) expression. Furthermore, the beneficial effects of DPP4 inhibition or knockdown on endothelial cell senescence were at least partly dependent on SIRT1 and Nrf2 activation. In conclusion, our study demonstrated that DPP4 inhibition or silencing ameliorated endothelial senescence both in vivo and in vitro by regulating AMPK/SIRT1/Nrf2. DPP4 may be a new therapeutic target to combat endothelial senescence.

5.
Plant Biotechnol J ; 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-32061119

RESUMO

Rice tiller angle determines plant growth density and further contributes grain production. Although a few genes have been characterized to regulate tiller angle in rice, the molecular mechanism underlying the control of tiller angle via microRNA is poorly understood. Here, we report that rice tiller angle is controlled by OsmiR167a-targeted auxin response factors OsARF12, OsARF17 and OsARF25. In the overexpression of OsMIR167a plants, the expression of OsARF12, OsARF17 and OsARF25 was severely repressed and displayed larger tiller angle as well as the osarf12/osarf17 and osarf12/ osarf25 plants. In addition, those plants showed compromised abnormal auxin distribution and less sensitive to gravity. We also demonstrate that OsARF12, OsARF17 and OsARF25 function redundantly and might be involved in HSFA2D and LAZY1-dependent asymmetric auxin distribution pathway to control rice tiller angle. Our results reveal that OsmiR167a represses its targets, OsARF12, OsARF17 and OsARF25, to control rice tiller angle by fine-tuning auxin asymmetric distribution in shoots.

6.
Eur Radiol ; 30(4): 1938-1947, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31900705

RESUMO

OBJECTIVES: Identifying inflammation- or fibrosis-predominant strictures in Crohn's disease (CD) is crucial for treatment strategies. We evaluated the additive value of magnetisation transfer (MT) to conventional MRI for differentiating CD strictures using surgical histopathology as a reference standard. METHODS: Twenty-eight consecutive CD patients who underwent MRI preoperatively were recruited. MRI parameters included T2-weighted imaging (T2WI) hyperintensity, bowel wall thickness, enhancement pattern changes over time, enhancement pattern and gain ratio in dynamic contrast-enhanced phases, and MT ratio. Correlation analysis was performed using Spearman's rank test. Receiver operating characteristic curve analysis and Cohen's κ were used. A model with combined MRI variables characterising intestinal strictures was proposed and validated in 14 additional CD patients. RESULTS: Significant correlations with histological inflammation scores were shown for wall thickness (r = 0.361, p = 0.001) and T2WI hyperintensity (r = 0.396, p < 0.001), whereas histological fibrosis scores were significantly correlated with MT ratio (r = 0.681, p < 0.001) and wall thickness (r = 0.461, p < 0.001). T2WI hyperintensity could differentiate mild from moderate-to-severe inflammation with a sensitivity of 0.871 and a specificity of 0.800. MT ratio could discriminate mild from moderate-to-severe fibrosis with a sensitivity and a specificity of 0.913 and 0.923, respectively. Combining MT ratio and T2WI hyperintensity, the MRI classification moderately agreed with the pathological stricture classification (p < 0.01, κ = 0.549). In the validation set, the diagnostic accuracy of T2WI hyperintensity and MT ratio were 86% and 89%, with good agreement between MRI and histopathological classification (p < 0.01, κ = 0.665). CONCLUSIONS: MT ratio combined with conventional MRI improves the differentiation of fibrotic from inflammatory components of small-bowel strictures in CD patients. KEY POINTS: • MT ratio from magnetisation transfer imaging combined with T2WI from conventional MRI can simultaneously characterise bowel fibrosis and inflammation in adult Crohn's disease.

7.
Angew Chem Int Ed Engl ; 59(2): 833-838, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31573739

RESUMO

Interpenetration in metal-organic frameworks (MOFs) is an intriguing phenomenon with significant impacts on their properties, and functional applications. Herein, we show that a 7-fold interpenetrated MOF (1) is transformed into an 8-fold interpenetrated MOF by the loss of DMF in a single-crystal-to-single-crystal manner. This is accompanied by a giant enhancement of the second harmonic generation (SHG ca. 125 times) and two-photon photoluminescence (ca. 14 times). The strengthened π-π interaction between the individual diamondoid networks and intensified oscillator strength of the molecules aid the augment of dipole moments and boost the nonlinear optical conversion efficiency. Large positive and negative thermal expansions of 1 occur at 30-150 °C before the loss of DMF. These results offer an avenue to manipulate the NLO properties of MOFs using interpenetration and provide access to tunable single-crystal NLO devices.

8.
Opt Express ; 27(23): 33757-33767, 2019 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-31878437

RESUMO

A new method to control heat flux, called thermal surface transformation (TST), is introduced from transformation thermodynamics. Compared with transformation thermodynamics, TST has many advantage. First, there is no mathematical calculation during the whole process in TST (novel thermal devices can be designed graphically in a surface-to-surface way). Second, all thermal devices of various functions, shapes and sizes designed by TST only require one homogenous anisotropic thermal medium, i.e., thermal-null medium (TNM). With the help of the effective medium theory, TNM can be realized by layered copper and expanded polystyrene, whose performance on controlling heat flux by TST is verified by numerical simulations. Many examples are given, including thermal imaging devices, thermal unidirectional cloak, concentrator, rotator and thermal focusing devices.

9.
Clin Cardiol ; 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31777973

RESUMO

The optimal antiplatelet therapy after percutaneous coronary intervention (PCI) remains to be elucidated. Monotherapy with a P2Y12 inhibitor may be inferior to dual antiplatelet therapy in patients after PCI. PubMed, EMBASE (by Ovidsp), Web of Science, and The Cochrane Library were searched from database inception to 2 October 2019. The composite of cardiovascular outcomes, all-cause mortality, myocardial infarction (MI), stroke, stent thrombosis, and major bleeding were evaluated. Pooled outcomes were presented as relative risk (RR) and 95% confidence intervals (CIs). A total of four trials randomizing 29 089 participants were included. Compared with the dual antiplatelet therapy group (n = 14 559), the P2Y12 inhibitor monotherapy group (n = 14 530) significantly decreased the incidence of bleeding events (2.0% vs 3.1%; RR: 0.60; 95% CI: 0.43-0.84; P = .005). There were no significant differences in all-cause mortality (1.3% vs 1.5%; RR: 0.87; 95% CI, 0.71-1.06; P = .16), myocardial infarction (2.1% vs 1.9%; RR, 1.06; 95% CI, 0.90-1.25; P = .46), stroke (0.6% vs 0.5%; RR, 1.18; 95% CI, 0.67-2.07; P = .57), or stent thrombosis (0.5% vs 0.4%; RR, 1.14; 95% CI, 0.81-1.61; P = .44) between the two groups. P2Y12 inhibitor monotherapy did not show any significant difference in the adverse cardiac and cerebrovascular events, but markedly decreased the risk of bleeding among patients after PCI vs dual antiplatelet therapy. However, it still needs to be further confirmed due to limited data.

10.
BMC Genomics ; 20(1): 890, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31752673

RESUMO

BACKGROUND: Dictyostelid social amoebas self-organize into fruiting bodies, consisting of spores and up to four supporting cell types in the phenotypically most complex taxon group 4. High quality genomes and stage- and cell-type specific transcriptomes are available for representative species of each of the four taxon groups. To understand how evolution of gene regulation in Dictyostelia contributed to evolution of phenotypic complexity, we analysed conservation and change in abundance, functional domain architecture and developmental regulation of their transcription factors (TFs). RESULTS: We detected 440 sequence-specific TFs across 33 families, of which 68% were upregulated in multicellular development and about half conserved throughout Dictyostelia. Prespore cells expressed two times more TFs than prestalk cells, but stalk cells expressed more TFs than spores, suggesting that gene expression events that define spores occur earlier than those that define stalk cells. Changes in TF developmental expression, but not in TF abundance or functional domains occurred more frequently between group 4 and groups 1-3, than between the more distant branches formed by groups 1 + 2 and 3 + 4. CONCLUSIONS: Phenotypic innovation is correlated with changes in TF regulation, rather than functional domain- or TF acquisition. The function of only 34 TFs is known. Of 12 TFs essential for cell differentiation, 9 are expressed in the cell type for which they are required. The information acquired here on conserved cell type specifity of 120 additional TFs can effectively guide further functional analysis, while observed evolutionary change in TF developmental expression may highlight how genotypic change caused phenotypic innovation.

11.
ACS Appl Mater Interfaces ; 11(37): 34171-34177, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31438674

RESUMO

Ambipolar semiconducting materials have great potential in complementary-like organic logic circuits. Accessing such logic circuits demands balanced hole and electron mobilities. However, the lack of ambipolar high-mobility polymer semiconductors with balanced charge carrier-transporting properties precludes the rapid development of organic logic circuits. In this context, structural modification of semiconductor materials to enhance the electron/hole transport is of great urgency. Herein, a multifunctionalization strategy is used to achieve this goal. Combined electron-withdrawing moieties involving fluorine and pyridinic nitrogen atoms can not only reduce the frontier molecular orbital energies but also planarize the polymer backbone, demonstrating synergetic effects on the control over the carrier injection process at the metal-semiconductor interface and microstructure-sensitive charge transport in the channel. A balanced ambipolar behavior with electron/hole mobilities of 3.88/3.44 cm2 V-1 s-1 was observed, and complementary-like inverters with high gains of greater than 200 were achieved. Microstructure and thin-film morphology were characterized to further reveal the relationship between device performances and macroscopic observables. This multifunctionalization strategy bodes well for developing new ambipolar semiconducting materials.

12.
Shock ; 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31318834

RESUMO

BACKGROUND: Sepsis is a life-threatening organ dysfunction initiated by a dysregulated response to infection, with imbalanced inflammation and immune homeostasis. Macrophages play a pivotal role in sepsis. N-[1-(1-oxopropyl)-4-piperidinyl]-N'-[4-(trifluoromethoxy)phenyl)-urea (TPPU) is an inhibitor of soluble epoxide hydrolase (sEH), which can rapidly hydrolyze epoxyeicosatrienoic acids (EETs) to the bio-inactive dihydroxyeicosatrienoic acids (DHETs). TPPU was linked with the regulation of macrophages and inflammation. Here, we hypothesized that sEH inhibitor TPPU ameliorates cecal ligation and puncture (CLP)-induced sepsis by regulating macrophage functions. METHODS: A polymicrobial sepsis model induced by CLP was used in our study. C57BL/6 mice were divided into four groups: (1) sham+PBS, (2) sham+TPPU, (3) CLP+PBS, (4) CLP+TPPU. Mice were observed 48 hours after surgery to assess the survival rate. For other histological examinations, mice were sacrificed 6 hours after surgery. Macrophage cell line RAW264.7 was used for in vitro studies. RESULTS: TPPU treatment, accompanied with increased EETs levels, markedly improved the survival of septic mice induced by CLP surgery, which was associated with alleviated organ damage and dysfunction triggered by systemic inflammatory response. Moreover, TPPU treatment significantly inhibited systemic inflammatory response via EETs-induced inactivation of MAPK signaling due to enhanced macrophage phagocytic ability and subsequently reduced bacterial proliferation and dissemination, and decreased inflammatory factors release. CONCLUSIONS: sEH inhibitor TPPU ameliorates cecal ligation and puncture-induced sepsis by regulating macrophage functions, including improved phagocytosis and reduced inflammatory response. Our data indicate that sEH inhibition has potential therapeutic effects on polymicrobial-induced sepsis.

13.
Cancer Manag Res ; 11: 4691-4697, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31191026

RESUMO

Aims: To examine the expression of CXCL16 in colorectal cancer (CRC) tissue and to clarify the relationships between CXCL16 and clinicopathological features and survival in CRC. Methods: A total of 142 consecutive CRC patients undergoing colorectal surgery at the Department of Gastrointestinal Center, First Affiliated Hospital, Sun Yat-sen University, between January 2010 and December 2010 were enrolled in this study. CXCL16 was measured by immunohistochemical staining in CRC tissue. Association between CXCL16 expression and clinicopathologic parameters was analyzed with a chi-square test. Survival curves were calculated by the Kaplan-Meier method, and the differences between CXCL16 high- and low-expression groups were analyzed using the log-rank test. Cox univariate and multivariate analyses were used to determine risk factors for overall survival (OS). Results: CXCL16 expression was elevated in CRC. CXCL16-positive expression was significantly related to tumor size (P=0.043), tumor differentiation (P=0.046) and distant metastasis (P=0.038), and there was a trend toward lymph node metastasis (P=0.070). CXCL16 expression, together with differentiation, depth of invasion, lymph node metastasis, and distant metastasis, was a significant independent prognostic factor for OS of patients with CRC (HR 2.026, 95% CI 1.128-3.640, P=0.018). Conclusion: CXCL16 expression was enhanced in CRC tissue and was negatively correlated with survival in CRC patients. Furthermore, CXCL16-positive expression was an independent prognostic factor for CRC patients, whilst the underlying mechanisms remain unclear; thus, further studies are needed.

14.
Cancer Manag Res ; 11: 4917-4930, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31213910

RESUMO

Aim: Identifying high-efficiency prognostic markers for colorectal cancer (CRC) is necessary for clinical practice. Increasing evidence demonstrates that apolipoprotein C1 (APOC1) promotes carcinogenesis in some human cancers. However, the expression status and biological function of APOC1 in CRC remain unclear. Materials and methods: We detected the association between APOC1 expression and clinicopathological features in 140 CRC patients by immunohistochemistry. Small interfering RNA (siRNA) technology was used to downregulate APOC1 expression in CRC cells. Cell proliferation was estimated by CCK8 and clonogenic assays. The cell cycle and apoptosis were analyzed by flow cytometry. Cell migration and invasion were examined by a transwell assay. Gene set enrichment analysis (GSEA) and protein expression of signaling pathways were used to suggest the possible APOC1-associated pathways in CRC. Results: APOC1 was highly expressed in CRC tissues. High immunohistochemistry (IHC) expression of APOC1 was correlated with the N stage, M stage and TNM stage. High IHC APOC1 expression in CRC tissues was associated with poor prognosis. Univariate and multivariate Cox regression analyses showed that APOC1 was an independent risk factor for OS. Cell proliferation of CRC cell lines was inhibited by the downregulation of APOC1. Moreover, si-APOC1 transfection induced cell cycle arrest but low apoptosis increases by regulating the expression of related proteins. Cell migration and invasion were also inhibited by the downregulation of APOC1. The Cancer Genome Atlas Colorectal Adenocarcinoma (TCGA COAD-READ) dataset analyzed by GSEA showed that APOC1 might be involved in the mitogen-activated protein kinase (MAPK) signaling pathway, which was further preliminarily confirmed by Western blotting. Conclusion: APOC1 was overexpressed in CRC tissues, and a high level of APOC1 contributed to a poor prognosis. APOC1 expression influenced the cell proliferation ability and motility capacity of CRC via the MAPK pathway. APOC1 could act as a novel prognostic biomarker in CRC.

15.
Nano Lett ; 19(8): 5109-5117, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31248259

RESUMO

Ultrathin ferroelectrics hold great promise for modern miniaturized sensors, memories, and optoelectronic devices. However, in most ferroelectric materials, polarization is destabilized in ultrathin films by the intrinsic depolarization field. Here we report robust in-plane ferroelectricity in few-layer tin sulfide (SnS) 2D crystals that is coupled anisotropically to lattice strain. Specifically, the intrinsic polarization of SnS manifests as nanoripples along the armchair direction due to a converse piezoelectric effect. Most interestingly, such nanoripples show an odd-and-even effect in terms of its layer dependence, indicating that it is highly sensitive to changes in inversion symmetry. Ferroelectric switching is demonstrated in field-effect transistor devices fabricated on ultrathin SnS films, in which a stronger ferroelectric response is achieved at negative gate voltages. Our work shows the promise of 2D SnS in ultrathin ferroelectric field-effect transistors as well as nanoscale electromechanical systems.

16.
Opt Express ; 27(12): A596-A610, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31252840

RESUMO

A silver grating containing three grooves with different depths in one period was proposed as the back electrode for improving light absorption in organic solar cells. We found that the broadband absorption enhancement of the active layer covering the visible and near-infrared bands can be obtained due to the excitation of surface plasmon resonance and the multiple resonances of cavity mode. The integrated absorption efficiency of the proposed structure under TM polarization between 350 nm to 900 nm is 57.4%, with consideration of the weight of AM 1.5G solar spectrum, and is increased by 13.4% with respect to the equivalent planar device. Besides, the wide-angle absorption in proposed structure can be observed in the range from 0 to 50 degrees. These findings are of great importance for rationally designing composite nanostructures of metal gratings-based absorbers for sensing and photon-detecting applications.

17.
J Phys Chem Lett ; 10(11): 2869-2873, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31088074

RESUMO

Recently, some organic-inorganic hybrid perovskites (OIHPs) have been reported to exhibit strong subgap broadband luminescence. While the origin of such luminescence has been proposed by several groups, a strategy to prepare OIHP with the desired subgap emission properties has remained elusive. Here, we report controlled synthesis of a broadband-emitting single-crystal 2D OIHP with an average quantum yield of >80 %. We demonstrate that the intensity of broadband emission can be tuned by controlling the excess iodine ion concentration during the synthesis in hydroiodic acid. We show that the emitters exhibit characteristics of localized defects such as limited mobility and saturation at high excitation power. Using density functional theory calculations, we show that bond-state iodine interstitials are responsible for the observed long-lived luminescence.

18.
J Nanosci Nanotechnol ; 19(9): 5661-5666, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30961722

RESUMO

Well dispersed CeO2 nanoparticles are prepared by azeotropic co-precipitation method. (Ba0.96Ca0.04)(Ti0.90Sn0.10)O3 lead-free piezoelectric ceramics doped with nano-CeO2 (x =0 mol%, 0.03 mol%, and 0.07 mol%) and micro-CeO2 (x = 0.03 mol%) are prepared at 1430 °C for 2 h by the conventional solid state sintering method. XRD diffraction indicates that all components have typical perovskite structure. Both doping of nano-CeO2 and micro-CeO2 can inhibit grain growth. And the average grain size decreased apparently with the increase of nano-CeO2 amount. All the samples exhibit typical diffuse phase transition behavior. The optimized electrical performances are obtained at x = 0.03 mol% with d33 = 512 pC/N, kp = 41.5%, and Pr = 14.00 µC/cm².

19.
FASEB J ; 33(7): 8436-8452, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30995868

RESUMO

Cardiac aging is characterized by myocardial hypertrophy, fibrosis, and diastolic dysfunction. Human kallikrein (hKLK1) protects against fibrosis in various pathogenic states. However, the effects of hKLK1 overexpression on cardiac aging-related fibrosis and the underlying mechanisms remain unknown. Moreover, the role of hKLK1 in regulating macrophage function leading to cardiac fibrosis has not been investigated. Thus, in this study, we determined the effects of hKLK1 on cardiac aging and explored the mechanisms through which hKLK1 regulated aging-related fibrosis. Echocardiographic measurements showed that aging caused significant alternations in cardiac morphology, hypertrophy, and fibrosis in rats, and hKLK1 overexpression protected against aging-induced cardiac dysfunction. Compared with wild-type hearts, the hKLK1 transgene decreased the expression of monocyte chemoattractant protein 1 and suppressed mitochondrial dysfunction and excess oxidative stress, leading to decreased recruitment and retention of alternatively activated (M2) macrophages and reduced secretion of profibrotic cytokines mediated by the TGF-ß1-Smad3 signaling pathway in hearts of aging rats. Furthermore, these cardioprotective effects of hKLK1 overexpression were associated with the Janus kinase-signal transducer and activator of transcription 3 signaling pathway. H2O2-induced senescence promoted the differentiation of RAW264.7 cells into M2-type cells induced by IL-4 treatment. Bradykinin treatment relieved the migratory capacity of macrophages induced by H2O2. Thus, hKLK1 overexpression reduced cardiac fibrosis and improved aging-related cardiac dysfunction through reduced shift of macrophages to M2 macrophages, indicating that hKLK1 may alleviate aging-related cardiac dysfunction.-Hu, D., Dong, R., Yang, Y., Chen, Z., Tang, Y., Fu, M., Wang, D. W., Xu, X., Tu, L. Human kallikrein overexpression alleviates cardiac aging by alternatively regulating macrophage polarization in aged rats.

20.
Nanoscale ; 11(7): 3186-3192, 2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30723854

RESUMO

CsPb2Br5 is a new member of the all-inorganic lead halide perovskite family with unique structures and optoelectronic properties for various applications. As an indirect band gap semiconductor, the photoluminescence (PL) mechanism of CsPb2Br5 is still under debate. To resolve this issue, CsPb2Br5 microplates with strong green PL have been prepared by a hot-injection method. Characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and ultraviolet-visible (UV-vis) absorption spectroscopy indicates the existence of a small amount of embedded CsPbBr3 phase. The removal of the embedded CsPbBr3 phase by treatment with water containing ethanol solvent resulted in complete PL quenching, suggesting the origin of PL due to the embedded CsPbBr3 phase. Spatially resolved PL and time-resolved PL mapping have been further employed to directly visualize the spatial distribution of different emission centers. Our single particle spectroscopic studies indicated the existence of three different emission centers with different PL lifetimes: two types of embedded CsPbBr3 phases (clumped and randomly distributed CsPbBr3 nanocrystals) and intrinsic defects of CsPb2Br5. The embedded CsPbBr3 phases with fast and intermediate PL lifetimes are the primary contributors to PL of the CsPb2Br5 microplates while their intrinsic defects with slow PL lifetimes make only a minor contribution. These studies have unambiguously clarified the PL mechanisms of the CsPb2Br5 microplates and provided the direct mapping of different emission centers, which resolve the contradictory explanation and debate about the PL mechanism of the CsPb2Br5 microplates.

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