Interionic Energy Transfer in Y\u3csub\u3e3\u3c/sub\u3eAl\u3csub\u3e5\u3c/sub\u3eO\u3csub\u3e12\u3c/sub\u3e: Ce\u3csup\u3e3+\u3c/sup\u3e, Pr\u3csup\u3e3+\u3c/sup\u3e Phosphor

We present an investigation of dynamical processes of nonradiative energy transfer (ET)between Ce3+ and Pr3+ , and between Pr3+ ions in Y3Al5O12:Ce3+ , Pr3+ phosphor.Photoluminescence spectroscopy and fluorescence decay patterns are studied as a function ofPr3+ and Ce3+ concentrations. The analysis based on Inokuti–Hirayama model indicates that the ET from the lowest 5d state of Ce3+ to the D12 state of Pr3+ , and the quenching of theD12 state through a cross relaxation involving Pr3+ ions in the ground state are both governed by electric dipole–dipole interaction. An increase in the Ce3+–Pr3+ ET rate followed by the enhanced red emission line of Pr3+ relative to the yellow emission band of Ce3+ on only increasing Ce3+ concentration is observed. This behavior is attributed to the increase in thespectral overlap integrals between Ce3+ emission and Pr3+ excitation due to the fact that the yellow band shifts to the red spectral side with increasing Ce3+ concentration while the red line dose not move. For Ce3+ concentration of 0.01 in YAG:Ce3+ , Pr3+ , the rate constant and critical distance are evaluated to be 4.5×10−36 cm6 s−1 , 0.81 nm for Ce3+–Pr3+ ET and2.4×10−38 cm6 s−1 , 1.30 nm for Pr3+–Pr3+ ET. Spectroscopic study also demonstrates a pronounced ET from the lowest 4f5d of Pr3+ to the 5d of Ce3+ . A proportional dependence of the initial transfer rate on acceptor concentration is observed in each of these ET pathways. The proportional coefficient as the averaged ET parameters for initial decay are determined, meaning the ET efficiency for the same concentration of acceptors follows the order ofPr3+–Pr3+\u3ePr3+–Ce3+\u3eCe3+–Pr3+

Color Control and White Light Generation of Upconversion Luminescence by Operating Dopant Concentrations and Pump Densities in Yb\u3csup\u3e3+\u3c/sup\u3e, Er\u3csup\u3e3+\u3c/sup\u3e, and Tm\u3csup\u3e3+\u3c/sup\u3e Tri-Doped Lu\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e Nanocrystals

We synthesized a series of Yb3+, Er3+ and Tm3+ tri-doped Lu2O3 nanocrystals with various dopant concentrations by the hydrothermal approach. Due to a unique electronic state at the top of the valence band, Lu2O3 based materials exhibit intense upconversion luminescence involving 1G4 → 3H6 of Tm3+ in blue, (2H11/2, 4S3/2) → 4I15/2 in green and 4F9/2 → 4I15/2 in red of Er3+ upon near infrared excitation at 980 nm. The variation of upconversion spectra and color points with dopant concentrations and pump densities are studied in detail on the basis of energy transfer processes. An ideal white upconversion light with color coordinates of (0.327, 0.339) is obtained by controlling the intensity of red, green, and blue emission in Lu1.906Yb0.08Er0.008Tm0.006O3nanocrystals under a pump density of 8 W cm−2. Based on the present experimental data, we may predict the dopant concentrations and pump densities for any color point within or around the white light region in the tri-doped Lu2O3 nanocrystals

Long-Lasting Phosphorescence in BaSi\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e2\u3c/sub\u3eN\u3csub\u3e2\u3c/sub\u3e:Eu\u3csup\u3e2+\u3c/sup\u3e and Ba\u3csub\u3e2\u3c/sub\u3eSiO\u3csub\u3e4\u3c/sub\u3e:Eu\u3csup\u3e2+\u3c/sup\u3e Phases for X-Ray and Cathode Ray Tubes

We report the long-lasting bluish-green phosphorescence for X-ray or cathode ray tubes in the phosphors with compositions of either Ba2SiO4:0.01Eu2+–xSi3N4 (x=0–1) or 2BaCO3–ySi3N4:0.01Eu2+(y=1/6–1) synthesized by a solid-state reaction. By tuning the Si3N4content, the phosphorescence may originate from Eu2+ in BaSi2O2N2(peaking at 490 nm), Ba2SiO4 (505 nm), and Ba3SiO5 (590 nm) phases. The strong phosphorescence of the Ba2SiO4:Eu2+ phase in 2BaCO3–ySi3N4:0.01Eu2+ is attributed to N substitution for O to generate a shallow trap. In Ba2SiO4:0.01Eu2+–xSi3N4 , however, N prefers reacting with Ba2SiO4 to form BaSi2O2N2 , thereby exhibiting a strong phosphorescence of the BaSi2O2N2:Eu2+ phase but a weak phosphorescence of the Ba2SiO4:Eu2+ phase

Metastatic patterns and prognosis of patients with primary malignant cardiac tumor

BackgroundDistant metastases are independent negative prognostic factors for patients with primary malignant cardiac tumors (PMCT). This study aims to further investigate metastatic patterns and their prognostic effects in patients with PMCT.Materials and methodsThis multicenter retrospective study included 218 patients with PMCT diagnosed between 2010 and 2017 from Surveillance, Epidemiology, and End Results (SEER) database. Logistic regression was utilized to identify metastatic risk factors. A Chi-square test was performed to assess the metastatic rate. Kaplan–Meier methods and Cox regression analysis were used to analyze the prognostic effects of metastatic patterns.ResultsSarcoma (p = 0.002) and tumor size¿4 cm (p = 0.006) were independent risk factors of distant metastases in patients with PMCT. Single lung metastasis (about 34%) was the most common of all metastatic patterns, and lung metastases occurred more frequently (17.9%) than bone, liver, and brain. Brain metastases had worst overall survival (OS) and cancer-specific survival (CSS) among other metastases, like lung, bone, liver, and brain (OS: HR = 3.20, 95% CI: 1.02–10.00, p = 0.046; CSS: HR = 3.53, 95% CI: 1.09–11.47, p = 0.036).ConclusionPatients with PMCT who had sarcoma or a tumor larger than 4 cm had a higher risk of distant metastases. Lung was the most common metastatic site, and brain metastases had worst survival among others, such as lung, bone, liver, and brain. The results of this study provide insight for early detection, diagnosis, and treatment of distant metastases associated with PMCT

808 nm driven Nd 3+

The in vivo biological applications of upconversion nanoparticles (UCNPs) prefer excitation at 700-850 nm, instead of 980 nm, due to the absorption of water. Recent approaches in constructing robust Nd3+ doped UCNPs with 808 nm excitation properties rely on a thick Nd3+ sensitized shell. However, for the very important and popular Frster resonance energy transfer (FRET)-based applications, such as photodynamic therapy (PDT) or switchable biosensors, this type of structure has restrictions resulting in a poor energy transfer. In this work, we have designed a NaYF4:Yb/Ho@NaYF4:Nd@NaYF4 core-shell-shell nanostructure. We have proven that this optimal structure balances the robustness of the upconversion emission and the FRET efficiency for FRET-based bioapplications. A proof of the concept was demonstrated for photodynamic therapy and simultaneous fluorescence imaging of HeLa cells triggered by 808 nm light, where low heating and a high PDT efficacy were achieved

Anatomy of a Lacustrine Stratigraphic Sequence within the Fourth Member of the Eocene Shahejie Formation Along the Steep Margin of the Dongying Depression, Eastern China

A comprehensive study on rift stratigraphy requires a solid understanding of sequence architecture along the steep margins of rift basins. This study analyzes an Eocene lacustrine sequence along the steep margin of the Dongying depression in eastern China through integrated core, well-log, and three-dimensional seismic analyses. The lacustrine sequence is bounded by unconformities and their correlative conformities at the base and top and consists of three systems tracts, namely an early expansion systems tract (EEST), late expansion-early contraction systems tract (LEECST), and late contraction systems tract (LCST),which record a lake expansion-contraction cycle. These systems tracts differ in thickness and development of depositional systems. The EEST is the thickest and contains well-developed marginal and basinal fan systems with an overall retrogradational stacking pattern. The well-developed fan systems are the most striking features within the sequence. The LEECST is the most widespread and contains dominantly profundal-sublittoral deposits. The LCST is the thinnest, with poorly developed fan systems, and is characterized by significant erosion by fluvial incision. The variable thickness and development of depositional systems in the three systems tracts are the responses to the interplay of sediment supply and accommodation space. Accommodation space establishes the framework for sedimentary infill, and sedimentsupply determines spatial distribution and temporal evolution of depositional systems within each systems tract. This study provides a lake expansion-contraction scheme to divide a lacustrine stratigraphic sequence into systems tracts and highlights the feasibility of applying this approach in studying sequence stratigraphy along the steep margin of a lacustrine rift basin. The results also provide understandings for the development, distribution, and evolution of depositional systems and their controlling factors along the steep margin of other rift basins in the world

Intense Green/Yellow Emission in Ca\u3csub\u3e8\u3c/sub\u3eZn(SiO\u3csub\u3e4\u3c/sub\u3e)\u3csub\u3e4\u3c/sub\u3eCl\u3csub\u3e2\u3c/sub\u3e:Eu\u3csup\u3e2+\u3c/sup\u3e, Mn\u3csup\u3e2+\u3c/sup\u3e through Energy Transfer for Blue-LED Lighting

Eu2+ and Mn2+ co-doped Ca8Zn(SiO4)4Cl2 phosphors have been synthesized by a high temperature solid state reaction. Energy transfer from Eu2+ to Mn2+ is observed. The emission spectra of the phosphors show a green band at 505 nm of Eu2+ and a yellow band at 550 nm of Mn2+. The excitation spectra corresponding to 4f7-4f65d transition of Eu2+ cover the spectral range of 370–470 nm, well matching UV and/or blue LEDs. The shortening of fluorescent lifetimes of Eu2+ followed by simultaneous increase of fluorescent intensity of Mn2+ with increasing Mn2+ concentrations is studied based on energy transfer. Upon blue light excitation the present phosphor can emit intense green/yellow in comparison with other chlorosilicate phosphors such as Eu2+ and Mn2+ co-doped Ca8Mg(SiO4)4Cl2 and Ca3SiO4Cl2, demonstrating a potential application in phosphor converted white LEDs

Enriching Red Emission of Y\u3csub\u3e3\u3c/sub\u3eAl\u3csub\u3e5\u3c/sub\u3eO\u3csub\u3e12\u3c/sub\u3e: Ce\u3csup\u3e3+\u3c/sup\u3e by Codoping Pr\u3csup\u3e3+\u3c/sup\u3e and Cr\u3csup\u3e3+\u3c/sup\u3e for Improving Color Rendering of White LEDs

Triply doped Y3Al5O12: Ce3+, Pr3+, Cr3+ phosphors are prepared by solid state reaction. The emission spectra are enriched in the red region with the luminescence of both Pr3+ and Cr3+through Ce3+→Cr3+ and Ce3+→Pr3+→Cr3+ energy transfers. The properties of photoluminescence and fluorescence decay indicates larger macroscopic Ce3+→Cr3+ transfer rates in the triply doped phosphors in comparison to Ce3+ and Cr3+ doubly doped one, reflecting the effect of competition between Ce3+→Cr3+ and Ce3+→Pr3+ transfers. White LEDs fabricated using the triply doped phosphor coated on blue LED chips show a color rendering index of 81.4 higher than that either using Ce3+ and Cr3+ doubly doped or Ce3+ singly doped phosphor