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CaSc2O4:Ce3+ is a well-known green emitting phosphor, but needs to match with suitable red emitting phosphors in practical white lighting. Herein, a site engineering strategy is proposed to modify the local coordination environment of Ce3+ by introducing Y3+ and Mg2+ ions into the CaSc2O4 crystal lattice. The obtained results indicate in the modified Ce3+-doped samples (CSO-YMg), Y3+ ions can occupy both Sc3+ and Ca2+ sites simultaneously, and the Y3+ ions tend to occupy Ca2+ sites in low-doped stage and enter into the Sc3+ sites in the high-doped stage. The introduction of Y3+ ions gives rise to the existence of MgO in as-prepared CSO-YMg samples, and it can be effectively washed through pickling. In the spectral aspect, with the increase of Y3+ and Mg2+ ions, the main emission peak is red-shifted from 512 nm to 530 nm upon excitation at 450 nm. However, the high-doped sample presents much stronger thermally induced fluorescence quenching than CaSc2O4:Ce3+. The lattice defects caused by doped ions (Y3+ and Mg2+) and the non-radiative energy transfer process between the Ca2+ (Ce3+) and Sc3+ (Ce3+ or Ce4+) sites should be responsible for such evident quenching phenomenon in CSO-YMg, which is obviously different from the emitting feature of CaSc2O4:Ce3+ (only at Ca2+ sites). Besides, utilizing the as-prepared CSO-5 phosphors and a blue LED (~450 nm), a WLED was successfully fabricated, yielding a comparable performance to those with commercial Y3Al5O12:Ce3+ phosphors. What discussed in this study would bring some inspirations in the exploration and understanding of Ce3+-based phosphors according to local structural modification.

Eu3+ lanthanide ion possesses abundant 4f-4f transition lines in the visible spectral region, and its spectroscopic changes can sensitively reflect the variation of local ligand environments. Here, Eu3+ ions are successfully introduced into Ca4Al6SO16 lattice, and the structural difference from orthorhombic (o-Ca4Al6SO16) to cubic (c-Ca4Al6SO16) phases is systematically analyzed. On that basis, the related influence on crystal-field splitting of Eu3+ ions is discussed in detail. The obtained results indicate that Eu:o-Ca4Al6SO16 and Eu:c-Ca4Al6SO16 have three and two non-degenerate 5D0→7F0 transition peaks, respectively. Through the theoretical analysis and low-temperature (78 K) luminescent investigation with changing the excitation wavelength, those non-equivalent Ca2+ sites are assigned as o-Ca(1) (~577.6 nm), o-Ca(3) (~579.6 nm), o-Ca(4) (~580.6 nm), c-Ca(1) (~578.7 nm), and c-Ca(2) (~580.2 nm), respectively. In addition, with the increase of c-Ca4Al6SO16 content in the sintered product, the fluorescence intensity ratios of I580.6/I613.7, I616.2/I613.7 and I621/I613.7 present a gradual decreasing tendency. And, the introduction of c-Ca4Al6SO16 into the as-prepared product is beneficial for increasing the decay lifetime of the 5D0 excited state and enhancing the resistance capability to thermally induced fluorescence quenching. What discussed in this work might provide some useful thoughts for multi-phase studies and broaden the application range of lanthanide fluorescent probes.

This study was designed to investigate the chemical characterization of scrophularia ningpoensis polysaccharides (SNP) and its protective activity on the cerebral ischemia/reperfusin injury (CIRI) rats. SNP was successfully isolated and fractionated by anion exchange chromatography and gel filtration into different factions, namely SNP1, SNP2, SNP3, SNP2-A and SNP2-B. SNP2-A is consisted of mannose (Man), rhamnose (Rha), glucuronic Acid (Glu A), galacturonic Acid (Gal A), glucose (Glu), galactose (Gal), xylose (Xyl) and arabinose (Ara). The nervous defect symptoms, the brain infarct volume and brain water content of rats with CIRI were improved by pretreatment with SNP2-A. In addition, SNP2-A could increase SOD activities, but could reduce MDA, NO, NOS, IL-1β and TNF-α levels in brain tissues of rats with CIRI. Additionally, the reductive ERK protein expression and the elevated JNK and p38 protein expression stimulated by CIRI were all ameliorated by pre-treatment of SNP2-A. The results indicate that the protective effect may be related to the improvement of SNP2-A on the antioxidant capacity of brain tissue, the inhibition of inflammatory cytokines overproduction and the amelioration of MAPK pathway such as JNK, p38 and ERK proteins. These data provided an information for mechanistic studies for polysaccharide neuroprotective effects in CIRI.

High-color-rendering illumination is an important application direction in the development of white-light-emitting diodes (WLEDs). In this work, the Ce3+-activated Sr3Sc4O9-CaSc2O4 phosphors are successfully obtained by cation exchange from Sr3Sc4O9:Ce3+. Due to the high reaction activity and reaction rate in CaCl2 melt, the exchange process can be realized under much lower temperature than that of traditional high-temperature sintering, even near the melting point of CaCl2 (1058 K). The color tunability of as-prepared phosphors from orange to green is also easily tailored by adjusting the content of CaCl2. What is more, combining the exchanged phosphor and a blue LED, a high-color-rendering warm WLED is also demonstrated (CCT = 3555 K, Ra = 88, R9 = 94), which is comparable to most of commercial WLEDs. The obtained results not only manifest the potential application of ion exchange in preparing luminescent materials and adjusting corresponding spectral properties, but also provide a promising platform in developing the high-color-rendering warm white-light illumination.

The Upper Triassic Yanchang Formation Chang 6 Member (C6 Member) in the Ordos Basin is the typical crude oil-rich sandstone in China, and its density restrict the exploration and development potential of hydrocarbon as well as their evaluation accuracy. Reservoir characteristics was studied using thin section (TS) associated with particle and pore size image analysis, X-ray diffractions, scanning electron microscopy (SEM) and mercury intrusion porosimetry (MIP). Time was taken as the main axle combined with diagenetic history, burial history, thermal history and structure. Thus, formation mechanism of tight reservoir was discussed by building the porosity evolution model and calculation method using “diagenesis simulation” and “geological effect simulation”. Results show that after strong evolution and reconstruction, micro-nano pore throat system has developed and ultralow-low porosity-super low permeability tight sandstone reservoir has formed. Porosity evolution of Well H53 of C6 Member has revealed the correlations between the hydrocarbon charging and the porosity. Tight sandstone reservoir quality is affected by the maximum intergranular point-counted porosity, maximum compaction rate, maximum cementation rate, pore evolution of sample and the oil saturation, reasons for the formation of tight sandstone reservoir as well as its quality have been found out.

Eu3+-doped SrGa2O4 from γ- to β-phases is successfully manipulated by controlling sintered temperature from 1273 K to 1673 K. The related structural changes are characterized by the thermal analysis, Rietveld refinement and Raman investigation. And on that basis, the photoluminescence (PL) survey is used to study the corresponding crystal-field splittings of Eu3+ ions in γ- and β-SrGa2O4, which shows the obvious difference in the 4f-4f energy transitions of Eu3+ ions between two SrGa2O4 phases, especially in the non-degenerate 5D0→7F0 transition region. Both γ- and β-SrGa2O4 show two 5D0→7F0 transition peaks, being in agreement with the two nonequivalent Sr sites in each SrGa2O4 phase. For γ-SrGa2O4, it is 580.8 nm (SrO7) and 579 nm (SrO8), respectively, and for β-SrGa2O4, it is 579.6 nm (SrO7) and 578.7 nm (SrO8), respectively. The difference of Eu3+ crystal field splitting between SrO7 sites and SrO8 sites in γ-SrGa2O4 is larger than that in β-SrGa2O4, which is mainly derived from the larger polyhedral difference between two Sr sites (SrO7 and SrO8). What discussed in this work manifests the sensitive response of Eu3+ ions for the change of local structural surroundings, and further indicates the potential application of rare-earth fluorescent probes in the field of phase identification.

The design and development of phosphors have received widespread attention with the increasing demand for white light-emitting diodes (WLEDs). In this work, a series of Ce3+-doped gadolinium scandium aluminum garnet (GSAG) phosphors were successfully synthesized by the sol-gel method, and the relevant structural, optical, and lighting properties were investigated in detail. The optimal sintering process was optimized to 1873 K for 5 h under an Ar/H2 reduction atmosphere, and the structural analysis showed that the lattice parameters were gradually increased with an increase in Sc/Al substitution. The cationic substitution of GSAG adjusted the local coordination environments of Ce3+ ions effectively, and the increasing Sc3+-doped concentrations gave rise to a blue-shift of photoluminescence spectra and a decline of related fluorescence lifetimes. Furthermore, the doping concentration of Ce3+ ions was optimized and the concentration quenching mechanism was also clarified. Based on the temperature-dependent spectral survey, the thermally induced fluorescence quenching behavior of GSAG:Ce3+ (x = 1 at.%, y = 0.65) was measured, and the relevant activation energy was evaluated to 0.28 eV. Moreover, the effects of different Sc/Al substitution ratios on the thermal stability of GSAG:Ce3+ samples were also tested. Benefited from the tunable emission of GSAG:Ce3+ phosphors, the WLEDs device was fabricated by combining with a blue LED, yielding the Ra value of 82.1 and the CCT value of 3981 K. This study indicates the potential application of GSAG:Ce3+ phosphors in white lighting and also provides some guiding inspirations in the exploration of new garnet phosphors.

Vitellogenin (Vtg) in zebrafish (Danio rerio) is a core biomarker for screening environmental estrogens in test guidelines of the Organization for Economic Cooperation and Development. To accurately quantify zebrafish Vtg, lipovitellin (Lv), the main Vtg-derived yolk protein, was used as the antigen to establish a sandwich enzyme-linked immunosorbent assay (ELISA). The purified Lv was a phospholipoglycoprotein with apparent molecular weight of ~445kDa, and separated into three polypeptides corresponding to ~117, ~102, and ~23.8kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Immunological analysis confirmed the specificity of the anti-Lv antibody for Vtg and the immunological similarity between Vtg and Lv. Using the purified Lv and anti-Lv antibody, a sandwich ELISA with a detection limit of 4.3ng/mL and a detection range from 7.8 to 250ng/mL was developed. The intra- and inter-assay coefficients of variation were both below 10%. Moreover, the Lv standard curve was nearly identical to the Vtg standard curve, and paralleled serial whole-body homogenate dilutions of male zebrafish exposed to 17β-estradiol, demonstrating that the Lv-based ELISA could be used for quantification of zebrafish Vtg. Zebrafish Lv showed high stability during purification process, heat treatment, -80°C storage, and repeated freeze/thaw cycles. Additionally, the standard curve of Lv stored at -80°C for 3months exhibited higher robustness than that of Vtg stored under the same conditions. Finally, the usefulness of the ELISA for detecting estrogenic activity was verified by quantifying Vtg inductions in zebrafish exposed to monocrotophos.

Pr3+ lanthanide ions show enormous application potential in the optical thermometric field due to the abundant 4f5d → 4f and 4f → 4f transition lines. Pr3+-doped SrRE2O4 (Re = Sc, Lu and Y) luminescent thermometers are proposed in this study, and the relevant site occupancies of dopant Pr3+ ions are investigated based on the temperature-dependent steady-state and transient photoluminescence spectral analyses. The results obtained indicate the Pr3+ ions only enter into the Sr2+ sites in Pr3+:SrSc2O4, whereas can occupy the Sr2+ and RE3+ sites simultaneously in Pr3+:SrLu2O4 and Pr3+:SrY2O4. Meanwhile, the dependence of transient decay dynamics analyses on temperature further verifies the existence of the energy transfer mechanism between Pr3+ ions located at Y3+ (or Lu3+) and Sr2+ sites. The luminescence thermometry strategy on the basis of the 3P0 → 3H4 emissions from different Pr3+-doped sites (RE3+ and Sr2+) in Pr3+:SrLu2O4 and Pr3+:SrY2O4 exhibits high-performance temperature sensing, yielding a maximum relative sensitivity Sr of 1.63%·K−1 (400 K) for Pr3+:SrLu2O4 and 3.30%·K−1 (300 K) for Pr3+:SrY2O4. Moreover, Pr3+:SrY2O4 manifests excellent sensing performance in the physiological temperature range with a Sr value no lower than 1.90%·K−1. The temperature sensing approach discussed in this research would facilitate the development of new Pr3+-based sensing strategies.

The exploration of red phosphors is very meaningful for enhancing the color rendering index (CRI) of white-light-emitting diodes (WLEDs). Herein, the novel BLO:Ce3+ orange-red phosphors are successfully synthesized by the high-temperature solid-state reaction via introducing Ce3+ ions into the Ba3Lu4O9 host. Structural analysis shows there was only the BLO:Ce3+ phosphors in the obtained product according to the standard diffraction card. The optimal preparation condition is the single-pass sintering in H2 at 1873 K for 3 h. In the spectral aspect, the optimal Ce3+-doped concentration is 0.5 atom %, and the strongest excitation and emission peaks of are located at 410 nm and 584 nm, respectively. Compared to reported Ba3Sc4O9:Ce3+ phosphors, the emission peak of BLO:Ce3+ phosphors is effectively red-shifted to about 21 nm. The fluorescent lifetime of BLO:Ce3+ phosphors is about 11.45 ns. Based on the temperature-dependent spectral and structural investigations, the thermal fluorescent quenching of BLO:Ce3+ phosphors originates mainly from the surrounding change of Ce3+ ions, and it is more evident at the temperatures below 340 K. Moreover, the crystallographic sites of the Ce3+ ions in Ba3Lu4O9 are also verified according to the temperature-dependent photoluminescence characterization with the excitation of 355 nm and empirical theoretical analysis, suggesting the observed luminescence mainly comes from the Ce3+ ions located in the LuO6 and BaO6 polyhedra. Finally, utilizing the as-prepared BLO:Ce3+ phosphors, commercial green phosphors and a blue LED, the WLED device is fabricated with a warm white-light performance in the color rendering (Ra = 91.2 and R9 = 88) and color temperature (3758 K) aspects. This study indicates the potential application of BLO:Ce3+ orange-red phosphors in the white-light illumination, and also provides some guiding inspirations in the exploration new red oxide phosphors.

Smilax china L., popularly known as "Jin Gang Ten", has been widely used as a traditional herbal medicine for the treatment of gout, rheumatoid arthritis and other diseases for a long time in China.The present study was carried out to investigate the effect of Smilax china L. on hyperuricemia and renal dysfunction in induced hyperuricemic animals.Five fractions (petroleum ether, chloroform, ethyl acetate, n-butanol and residual ethanol fraction) of Smilax china L. were orally administered to potassium oxonate-induced hyperuricemic mice for three days. The xanthine oxidase inhibitory activities and modes of action of nine compounds isolated from ethyl acetate fraction (EAF) were then examined in vitro. Finally, different dosages of EAF were administered to 10% fructose-induced hyperuricemic rats.EAF (250 mg/kg) exhibited stronger anti-hyperuricemic activity in hyperuricemic mice compared with the other four fractions. Caffeic acid, resveratrol, rutin and oxyresveratrol isolated from EAF showed different inhibitory activities on xanthine oxidase in vitro, with the IC(50) values of 42.60, 37.53, 42.20 and 40.69 μM, respectively, and exhibited competitive or mixed inhibitory actions. Moreover, EAF (125, 250 and 500 mg/kg) markedly reversed the serum uric acid level (p0.05, p0.01 and p0.001, respectively), fractional excretion of urate (p0.05, p0.01 and p0.01, respectively) and blood urea nitrogen (p0.05, p0.01 and p0.01, respectively) to their normal states, and prevented the renal damage against tubulointerstitial pathologies in hyperuricemic rats.These findings show that Smilax china L. exhibits anti-hyperuricemic and nephroprotective activity in hyperuricemic animals.

Small businesses are the backbone of the U.S. economy and account for approximately one-half of the private-sector economy and 99% of all businesses. To start a small business, individuals need access to capital. Given the importance of an entrepreneur’s personal debt capacity in financing a startup business, student loan debt, which is difficult to discharge via bankruptcy, can have lasting effects and may have an impact on the ability of future small business owners to raise capital. This study examines the impact of the growth in student debt on net small business formation. We find a significant and economically meaningful negative correlation between changes in student loan debt and net business formation for the smallest group of small businesses, those employing one to four employees. This is important since these small businesses depend heavily on personal debt to finance new business formation. Based on our model, an increase of one standard deviation in student debt reduced the number of businesses with one to four employees by 14% on average between 2000 and 2010. The effect on larger firm formation decreased with firm size, which we interpret to mean that these firms have greater access to outside capital.