Salicylaldehyde-Cobalt(II)-Catalyzed C-H Alkoxylation of Indoles with Secondary Alcohols.

A straight and efficient protocol for the synthesis of hindered indole-ethers via C-H alkoxylation of indoles was developed by a cobalt-catalyzed cross-dehydrogenative coupling reaction with secondary alcohols. The selection of the salicylaldehyde-Co(II) catalyst enables the reaction to proceed under conditions without acid or base addition in the presence of limited alcohols. The protocol has broad substrate scope for both indole and secondary alcohols and exhibits good functional tolerance. The synthetic applications are proven by gram-scale reaction and further diversification of the product. Preliminary mechanistic investigations indicate that the activation of C-H bonds is not the rate-determining step of the reaction.

Diagnostic accuracy of NI-RADS for prediction of head and neck squamous cell carcinoma: a systematic review and meta-analysis.

OBJECTIVES: This study aimed to assess the diagnostic performance of NI-RADS for the prediction of recurrence in patients treated for Head and Neck Squamous Cell Carcinoma (HNSCC). METHODS: A literature search was conducted using various databases to identify relevant articles published from June 2016 onwards. We included studies reporting the diagnostic accuracy of NI-RADS in distinguishing recurrence in patients undergoing imaging surveillance, with pathologic results and/or follow-up as the reference standard. Summary estimates of diagnostic accuracy in terms of sensitivity, specificity, positive likelihood ratio (LR +), negative likelihood ratio (LR -), and diagnostic odds ratio (DOR) were calculated with the hierarchical summary receiver operating characteristic (HSROC) model. Meta-regression and subgroup analyses were conducted to investigate different clinical settings. Study quality was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: A total of 12 studies were included in the current meta-analysis. The pooled sensitivity and specificity were 0.69 (95% CI 0.59-0.79) and 0.94 (95% CI 0.89-0.97), respectively. For the primary site, the pooled summary estimates were 0.67 (95% CI 0.53-0.78) and 0.95 (95% CI 0.90-0.97), for the nodal sites were 0.64 (95% CI 0.44-0.80) and 0.99 (95% CI 0.98-0.99), respectively. The recurrence rate for NI-RADS categories 1-3 was 0.03 (95% CI 0.02-0.05), 0.13 (95% CI 0.10-0.15), and 0.77 (95% CI 0.73-0.81). Meta-regression revealed that the type of analysis (per person vs. per site) and number of sites (≤ 200 vs. > 200) were significant factors associated with heterogeneity. CONCLUSIONS: NI-RADS demonstrated high specificity but moderate sensitivity in patients after treatment for HNSCC. Summary estimates showed a significantly higher malignancy rate for NI-RADS category 3 compared to category 2.

Insights into the carbonization mechanism of PAN-derived carbon precursor fibers and establishment of a kinetics-driven accelerated reaction template for atomistic simulation.

To better understand the chemistry behind the carbonization process of the polyacrylonitrile (PAN)-based precursor fibers and provide a more authentic virtual counterpart of the process-inherited model for process optimization and rational performance design, we develop arrow-pushing reaction routes for primary exhaust gas product (H2O/H2/HCN/N2/tar vapor) formation and a pragmatic kinetics-driven accelerated reaction template for atomistic simulation of the carbonization process overcoming traditional challenges in time scale discrepancy of the reaction-diffusion system. The results of enthalpy barriers from hybrid first principles calculations validate the rationality and sequence of conjectured reactions during the two-stage carbonization process. Conversion rates of the rate-determining steps under 300 s carbonization are also estimated based on Eyring's transition state theory realizing kinetics equivalency of the reaction extent. Process-control measurements are further demonstrated corresponding to the proposed mechanism. The iterative densified crosslinking scheme specially designed for the surface layer is implanted into the topological reaction molecular dynamics template and a series of highly devisable structural models during the whole evolutionary process from the pre-oxidized fiber to the pristine carbon fiber surface are successfully predicted. The ultimate structure of the model presents excellent similarity in carbon yield and elemental composition with the type II high strength carbon fiber surface.

High-frequency vibration effects on material removal mechanisms in ultrasonic transverse scratching of carbon fiber reinforced plastics.

This paper represented some fundamental investigations on the potential effects of the high-frequency vibration on material removal mechanisms in ultrasonic transverse scratching of carbon fiber reinforced plastics (CFRPs). It was found that the ultrasonic superimposition brought about the evident reduction of the ductile-brittle transition depth of the unidirectional CFRPs. For the scratched groove generated without ultrasonic, the tensile stress and compressive stress caused by the indenter penetration were respectively responsible for the formations of the radial cracks at the leading edges and the central region. Under the combination of the inertia effects induced by the ultrasonic superposition and the skin-core structure of the carbon fibers, the micro-defects situated at the interior of the fibers were nucleated simultaneously, and their propagations caused the formations of the oblique cracks. Incorporated with the strain rate effects of the materials, a fresh theoretical model was proposed to describe the evolution of the mechanical stress during the scratching process. The fiber fragments induced by the oblique cracks were just concentrated on the top surface of the scratched groove, due to the coupling effects of the small penetration depth of the indenter and the express reduction of strain rate.

Systematic Review and Meta-Analysis of American College of Radiology TI-RADS Inter-Reader Reliability for Risk Stratification of Thyroid Nodules.

Purpose: To investigate the inter-reader agreement of using the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI-RADS) for risk stratification of thyroid nodules. Methods: A literature search of Web of Science, PubMed, Cochrane Library, EMBASE, and Google Scholar was performed to identify eligible articles published from inception until October 31, 2021. We included studies reporting inter-reader agreement of different radiologists who applied ACR TI-RADS for the classification of thyroid nodules. Quality assessment of the included studies was performed with the Quality Assessment of Diagnostic Accuracy Studies-2 tool and Guidelines for Reporting Reliability and Agreement Studies. The summary estimates of the inter-reader agreement were pooled with the random-effects model, and multiple subgroup analyses and meta-regression were performed to investigate various clinical settings. Results: A total of 13 studies comprising 5,238 nodules were included in the current meta-analysis and systematic review. The pooled inter-reader agreement for overall ACR TI-RADS classification was moderate (κ = 0.51, 95% CI 0.42-0.59). Substantial heterogeneity was presented throughout the studies, and meta-regression analyses suggested that the malignant rate was the significant factor. Regarding the ultrasound (US) features, the best inter-reader agreement was composition (κ = 0.58, 95% CI 0.53-0.63), followed by shape (κ = 0.57, 95% CI 0.41-0.72), echogenicity (κ = 0.50, 95% CI 0.40-0.60), echogenic foci (κ = 0.44, 95% CI 0.36-0.53), and margin (κ = 0.34, 95% CI 0.24-0.44). Conclusions: The ACR TI-RADS demonstrated moderate inter-reader agreement between radiologists for the overall classification. However, the US feature of margin only showed fair inter-reader reliability among different observers.

Evaluating photoneutron dose equivalents for lung cancer using PMMA phantoms undergoing 15 MV IMRT.

BACKGROUND: According to statistics of the Ministry of Health and Welfare in 2017, the second leading cause of death in Taiwan was lung cancer. OBJECTIVE: Routine treatment planning does not consider photoneutron dose equivalent (PNDE) of patient induced secondary radiation resulting from primary exposure of lung cancer. However, such treatment is potentially important for improving estimates of health risks. METHODS: This study used 10, 30, 50, 70, and 90 kg of polymethylmethacrylate (PMMA) phantoms as patient to measure PNDE varying anatomical area during lung cancer of intensity modulated radiotherapy (IMRT) treatment. Paired thermoluminescent dosimeters (TLD-600 and 700) were calibrated using university reactor neutrons. TLDs were inserted into phantom which was closely corresponded of the represented tissues or organs. RESULTS: Neutron doses (ND) of organ or tissue (N⁢DT) were determined in these phantoms using paired TLDs approach. The risks of incurring fatal secondary malignancies, maximum statistical and total errors were estimated. Evaluated PNDE ranged from 0.80 ± 0.12 to 0.56 ± 0.08 mSv/Gy for these phantoms. CONCLUSION: The estimated N⁢DT decreased with increasing distance that is from the central axis. Evaluated PNDE and N⁢D𝑠𝑘𝑖𝑛 for these phantoms were discussed. This investigation also identified secondary risks associated with PNDE relating to radiation protection.

Coordination-directed self-assembly of molecular motors: towards a two-wheel drive nanocar.

Designing and constructing hierarchical and stimuli-responsive motorized nanocar systems to perform useful tasks on-demand is highly imperative towards molecular nanotechnology. In this work, a most simplified two-wheel nanocar was successfully prepared through a facile strategy of coordination-directed self-assembly. The nanocar meso-AgL2 features a central pseudo square-planar Ag(I) which was bridged by two enantiomeric motors as the wheels that ensure the car moves in the same direction when observed externally. Thanks to the electronic push-pull characteristic of L and 3ILCT triplet sensitization, this nanocar can be driven by visible light up to 500 nm. Furthermore, it could be disassembled into individual motor elements through the addition of pyridine, thus allowing dynamic regulation over the function of the nanocar. Importantly, our STM imaging results showed very organized tilted layered structures for meso-AgL2 on highly oriented pyrolytic graphite (HOPG) that are quite similar to its crystalline ones, paving the way for future single molecule manipulations. The nanocar reported here represents the first example of integrating individual motors into a hierarchical motorized nanocar system via the facile coordination-directed self-assembly method and may offer a good starting point to realize its robotic functions, e.g., metal transportation and release.

Stepwise Increase of NdIII -Based Phosphorescence by AIE-Active Sensitizer: Broadening the AIPE Family from Transition Metals to Discrete Near-Infrared Lanthanide Complexes*.

We designed two near-infrared (NIR) lanthanide complexes [(L)2 -Nd(NO3 )3 ] (L=TPE2 -BPY for 1, TPE-BPY for 2) by employing aggregation-induced emission (AIE)-active tetraphenylethylene (TPE) derivatives as sensitizers, which possessed matched energy to NdIII , prevented competitive deactivation under aggregation, even shifted the excitation window toward 600 nm by twisted intramolecular charge transfer. Furthermore, benefiting from the 4 f electron shielding effect and antenna effect, the enhanced excitation energies of the AIE-active sensitizers by structural rigidification transferred into the inert NdIII excited state through 3 LMCT, affording the first aggregation-induced phosphorescence enhancement (AIPE)-active discrete NIR-emitting lanthanide complexes. As 1 equipped with more AIE-active TPE than 2, L→Nd energy transfer efficiency in the former was higher than that in the latter under the same conditions. Consequently, the crystal of 1 exhibited one of the longest lifetimes (9.69 µs) among NdIII -based complexes containing C-H bonds.

Discrete Heteropolynuclear Yb/Er Assemblies: Switching on Molecular Upconversion Under Mild Conditions.

The salts {[Ln2 Ln*(Hhmq)3 (OAc)3 (hfac)2 ]+ [Ln*(hfac)3 (OAc)(MeOH)]- } (Hhmq=2-methanolquinolin-8-oxide, hfac=hexafluoroacetylacetonate; Ln, Ln*=Er, Gd, Yb) feature a discrete heteronuclear cation consisting of two types of lanthanide atoms. The quinolinoxy O-atom serves as a µ2 -bridge to two Ln atoms and as a µ3 -bridge to all three atoms, with metal⋅⋅⋅metal distances being around 3.7 Å. For 1 ([Yb2 Er]+ ), near-infrared downshifted luminescence is switched to competitive upconversion luminescence upon irradiation by a 980 nm laser under an extremely low excitation power (0.288 W cm-2 ) through introduction of fluoride ions. The stability of 1 after addition of fluoride was confirmed by powder X-ray diffraction and multistage mass spectrometry, associated with the 1 H NMR of 6 ([La2 Eu]+ ). More importantly, the at least 20-fold enhancement of the quantum yield in non-deuterated solvents at room temperature under low power densities (2 W cm-2 ) is the highest among the few molecular examples reported.

Luminescence Switching of Organogold(I) Complexes between Aggregation-induced Phosphorescence Enhancement and Aggregation-caused Quenching by Balancing Auxiliary Ligands around the AuI Center.

Attaching AIE-active L1 ([1,1':2',1'':4'',1'''-quaterphenyl]-2-yldiphenylphosphane) to AuCl, shortened the distances of P-C bonds to promote electron cloud overlap between AuI and L1, affords 1 (L1AuCl) with aggregation-induced phosphorescence enhancement (AIPE) activity by 3 LMCT transitions. Then substituting the coplanar L2 (9-ethynylanthracene) for the Cl- in 1 providing 2, switches the luminescence to aggregation-caused quenching (ACQ) activity. Furthermore, we restore the performance from ACQ to AIPE by metathesis reactions to transfer 2 into 1. It is versatile synthetic strategy of reversible transformation between 1 and 2 that switches the luminescence of organogold(I) between AIPE and ACQ through balancing auxiliary ligands around the given metal.

Comparison of diagnostic performance between two prostate imaging reporting and data system versions: A systematic review.

OBJECTIVE: To compare the diagnostic performance between Prostate Imaging Reporting and Data System version 1(PI-RADS v1) and PI-RADS v2 for detection of prostate cancer (PCa). METHODS: A systematic literature search was performed from inception to September 31, 2018, in following databases MEDLINE, EMBASE, Cochrane Library, Google Scholar, in addition to Chinese National Knowledge Infrastructure (CNKI) and Wanfang Data database. Sensitivity and specificity of individual studies along with summary estimates were calculated and presented in forest plots. Multiple subgroup analyses and meta-regression were performed to investigate the heterogeneity. Quality of included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. RESULTS: 14 studies involving head to head comparison between PI-RADS v1 and v2 were included, with a total of 1682 patients. The pooled sensitivity for PI-RADS v1 and PI-RADS v2 were 85.37% (95% CI 79.29%-89.89%) and 87.79% (95% CI 79.84%-92.88%), with pooled specificity of 77.26% (95% CI 57.29%-89.58%) and 76.73% (95% CI 58.69%-88.44%), respectively. There was no substantial difference in diagnostic accuracy between PI-RADS v1 and PI-RADS v2 (P = 0.57 for sensitivity and P = 0.96 for specificity). Multiple subgroup analyses and meta-regression suggested these two scoring systems had comparable diagnostic performance on magnetic field strength, zonal anatomy, and outcome assessment. For the transitional zone, it seemed that PI-RADS v2 had higher sensitivity than PI-RADS v1 (90.1% vs. 80.59%), but the difference was not substantial (P = 0.17). CONCLUSION: PI-RADS v2 has slightly higher sensitivity but at the expense of minor decreased specificity. Thus, on the whole PI-RADS v1 and PI-RADS v2 have comparable diagnostic accuracy.

Thermally Induced trans-to-cis Isomerization and Its Photoinduced Reversal Monitored using Absorption and Luminescence: Cooperative Effect of Metal Coordination and Steric Substituent.

For ethene derivatives with large groups the cis-isomer is often quite unstable and unavailable. Herein, we report an exception of two stable coordination complexes, (cis-L)ZnCl2 , starting from trans-1,2-bis(1-R-benzo[d]imidazol-2-yl)ethene (R=H, L1; R=CH3 , L2) ligands under solvothermal condition (T ≥140 °C). Using the intensity of the absorption and luminescence spectra as probes we proposed its progressive cis-to-trans reversal upon irradiation with UV light, which was confirmed by powder X-ray diffraction (PXRD). Similar results observed in the series of (cis-L2)MII Cl2 [M=Fe (4), Co (5), Ni (6)] demonstrate the universal strategy. The results of PXRD, NMR spectroscopy, ESI-MS and DFT calculations support the above conclusion. NMR spectroscopy indicates that irradiation of 1 converts an optimized 71 % of the cis-isomer to trans, whereas the free trans-L1 ligand transforms to only 15 % cis-isomer under similar conditions.

Assembly Responses of Hippocampal CA1 Place Cells Predict Learned Behavior in Goal-Directed Spatial Tasks on the Radial Eight-Arm Maze.

Hippocampus is needed for both spatial working and reference memories. Here, using a radial eight-arm maze, we examined how the combined demand on these memories influenced CA1 place cell assemblies while reference memories were partially updated. This was contrasted with control tasks requiring only working memory or the update of reference memory. Reference memory update led to the reward-directed place field shifts at newly rewarded arms and to the gradual strengthening of firing in passes between newly rewarded arms but not between those passes that included a familiar-rewarded arm. At the maze center, transient network synchronization periods preferentially replayed trajectories of the next chosen arm in reference memory tasks but the previously visited arm in the working memory task. Hence, reference memory demand was uniquely associated with a gradual, goal novelty-related reorganization of place cell assemblies and with trajectory replay that reflected the animal's decision of which arm to visit next.

Tuning Semiconductor Performance of Nickel Complexes through Crystal Transformation.

Crystal transformation between two polymorphs (green, 1-G, and red, 1-R) of the square-planar nickel complex NiL2 (L = 2-ethoxy-6-( N-methyliminomethyl)phenolate) and their tuning effect to semiconductor properties were studied both experimentally and theoretically. When 1-G is heated to 413 K, it converts to 1-R, whereas soaking 1-R in several kinds of solvents causes it to revert to 1-G. Crystallographic and PXRD studies reveal the dramatic changes in crystal dimensions due to the changes of packing models. Heating device made from 1-G (D-1-G(298)) at 413 K significantly increases the electrical conductivity from 6.55 × 10-4 S cm-1 for D-1-G(298) to 1.11 × 10-3 S cm-1 for D-1-G(413), showing significant crystal form dependence. Heat-treating D-1-G and D-1-R devices at different temperatures clearly reveals the reason for the conductivity tuning. Thus, the conductivity of NiL2-based devices could be well tuned through crystal transformation by heating or by soaking in solvent. Theoretical calculations clearly revealed the reason for such conductivity changes and also predicted that both polymorphs are good p-type semiconductors with hole mobilities of 1.63 × 10-2 (1-G) and 2.11 × 10-1 cm2 V-1 s-1 (1-R).

Controlled synthesis of up-conversion luminescent Gd/Tm-MOFs for pH-responsive drug delivery and UCL/MRI dual-modal imaging.

Using a facile one-step hydrothermal method, a series of metal-organic frameworks containing Gd/Tm (Gd/Tm-MOFs) were prepared successfully. Through the mutual activation of Gd3+ and Tm3+, Gd/Tm-MOFs showed unexpected excellent up-conversion luminescence (UCL) and a superior positive magnetic resonance image (MRI). Using doxorubicin hydrochloride (DOX) as a drug model, the feasibility of Gd/Tm-MOFs as a multifunctional drug carrier was demonstrated. Through modifying Gd/Tm-MOFs with uniform mesoporous silica (mSiO2) shells and folic acid (FA), the drug loading was improved up to 41.5 mg g-1, and pH responsive drug release increased to 64% from 12% by regulating the pH from 5.8 to 7.4. Also, the particles were tracked by MRI, and the second highest longitudinal relaxivity (r1) among the reported gadolinium complexes of 225.86 mM-1 s-1 was achieved. The cell imaging shows obvious blue and red luminescence under 980 nm laser excitation, and the up-conversion luminescence is unique because there is no autofluorescence from cells under 980 nm excitation. This indicates their promising application in the biological field. All the experiments indicate the promising application of Gd/Tm-MOFs in diagnosis and treatment.

Fitted peaks data of O2--V5+ charge transfer bands and R/O data of Eu3+ doped Ca(VO3)2 and Ca3(VO4)2.

Data presented in this article are related to the research article entitledO2--V5+charge transfer band, chemical bond parameters and R/O of Eu3+doped Ca(VO3)2and Ca3(VO4)2: A comparable study[ing Li, Yu Pan, Wenjun Wang, Zihao Wen, Xuanxi Leng, Qi Wang, Liqun Zhou, Haibing Xu, Qinghua Xia, Li Liu, Hongping Xian, Xiaoguang Liu]. The data present the fitting results of the broad excitation spectra of Ca(VO3)2:1%Eu and Ca3(VO4)2:1%Eu using the Gaussian model, the O/R values using the experimental PL emission results. The data compares the optimized cell parameters for Ca(VO3)2: 1%Eu and Ca3(VO4)2:1%Eu through the CASTEP geometry optimization with their initial cell parameters.

Bond energy, site preferential occupancy and Eu2+/3+ co-doping system induced by Eu3+ self-reduction in Ca10M(PO4)7 (M = Li, Na, K) crystals.

Ca10M(PO4)7:Eu (M = Li, Na, K) phosphors have been synthesized via a solid-state reaction process, their phase purity was examined using XRD patterns, and Rietveld refinement confirmed that the Ca10Li(PO4)7, Ca10Na(PO4)7 and Ca10K(PO4)7 are pure phases. The photoluminescence properties of the Ca10M(PO4)7:Eu (M = Li, Na, K) phosphors showed that the self-reduction of Eu3+ to Eu2+ can occur in an air atmosphere. Eu3+ ions can be reduced to Eu2+ ions when doped in Ca10Li(PO4)7, Ca10Na(PO4)7 and Ca10K(PO4)7 crystals, which was detected using photoluminescence spectra. In this work, the bond energy method was used to determine and explain the mechanism of site occupation of Eu entering the host matrix. According to the calculated value of the deviation of bond energy for Eu3+-doped Ca10M(PO4)7 (M = Li, Na, K) crystals, the similar value between and , and , and and can provide the conditions for the self-reduction of Eu3+ in the Ca10M(PO4)7 (M = Li, Na, K) system. Meanwhile, the smaller deviation values of , , and in Ca10Li(PO4)7, Ca10Na(PO4)7, and Ca10K(PO4)7 crystals and in Ca10K(PO4)7 crystals indicated that the preferential sites of Eu ion occupancy in the Ca10M(PO4)7 (M = Li, Na, K) lattices are Li, Na, K and Ca sites. The conclusions obtained from the calculated results of the bond energy method are consistent with the Rietveld refinement and the photoluminescence spectra of Ca10M(PO4)7 (M = Li, Na, K).

Regulating structural dimensionality and emission colors by organic conjugation between SmIII at a fixed distance.

The conjugation of bridging bis(diphenylphosphine oxide) alkane or arene ligands was found to control the structural dimensionality and the emission color of complexes from reactions with SmIII(hfac)3(H2O)2 (hfac- = hexafluoroacetylacetonato) while retaining the SmSm distances. Bis(diphenylphosphine oxide)-1,4-butane (L1) affords a one-dimensional (1D) ribbon {Sm(hfac)3(L1)}∞ (1) that emits red color, while bis(diphenyl-phosphinoyl)-1,4-benzene (L2) results in a two-dimensional (2D) network {Sm(hfac)2(CF3COO)(L2)3}∞ (2) and near-white emission, but bis(diphenyl-phosphinoyl)-9,10-anthracene (L3) forms a zero-dimensional (0D) cyclic structure {Sm(hfac)3(L3)}2 (3) with strong ππ interactions that emit green color. Noticeably, the conjugation change is accompanied by a configurational change of coordination from trans for 1 and 2 to cis for 3. The color change is associated with the superposition of ligand and Sm based electronic band energies and their intensities. Such white light emission by a single compound having contributions from different building components is quite rare.

Sensitized near infrared emission through supramolecular d → f energy transfer within an ionic Ru(ii)-Er(iii) pair.

The newly synthesized ionic triple salt Ru-Er, {[RuII(bpy)2(dbim)][ErIII(hfac)4][CF3COO]·H2O} (bpy = 2,2'-bipyridine; hfac- = hexafluoroacetylacetonate; dbim = 2,2'-dibenzimidazole) exhibits near-infrared (NIR) emission at 1535 nm by intermolecular Ru → Er (d → f) energy transfer across supramolecular interactions when pumped within the Ru(ii) 3MLCT band. It is the first such observation for a transition metal-lanthanide ionic pair.

Eu3+/2+ co-doping system induced by adjusting Al/Y ratio in Eu doped CaYAlO4: preparation, bond energy, site preference and 5D0-7F4 transition intensity.

CaY1-x Al1+x O4:2%Eu (x = 0, 0.1, 0.2) phosphors have been synthesized via a solid-state reaction process. XRD patterns indicate that they are pure phase. The photoluminescence properties of the CaY1-x Al1+x O4:2%Eu phosphors exhibit both the blue emission of Eu2+ (4f65d1-4f7) and red-orange emission of Eu3+ (5D0-7F1,2,3,4) under UV light excitation, which showed that the Eu3+/2+ co-doping system was obtained by adjusting the Al/Y ratio. Eu3+ ions can be reduced to Eu2+ ions when the Al/Y ratio was changed. In this work, the bond energy method was used to determine and explain the mechanism of the site occupation of Eu ions entering the host matrix. Also, the emission spectrum showed an unusual comparable intensity 5D0-7F4 transition peak. The relative intensity of 5D0-7F2 and 5D0-7F4 can be stabilized by changing the relative proportions of Al3+ and Y3+. Furthermore, this was explained by the J-O theory.