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Nowadays, the development of phosphors with excellent luminescent thermal stability for various applications has become a research hotspot. Therefore, the Dy3+/Sm3+ co-activated multifunctional NaYTiO4 phosphors with excellent comprehensive performance in the field of non-contact optical measurement and white LED solid-state lighting were reported in this paper, and their crystal structure, elemental composition, optical bandgap and photoluminescence properties were systematically studied. Remarkably, the reason why NaYTiO4:Dy3+,Sm3+ phosphors achieved color-controlled emission from yellow to orange-red and even to white at the excitation wavelength of 363 nm was not based on the energy transfer process from Dy3+ to Sm3+ but on co-excitation. When the temperature reached 475 K, the luminescence intensity of the phosphor still maintained 96.75% of the initial intensity, demonstrating excellent thermal quenching property. Furthermore, the temperature sensing performance was evaluated by FIR technique according to the differential decreasing trend of Dy3+ and Sm3+ emission intensity with increasing temperature. Finally, we also certified the applicability of NaYTiO4:Dy3+,Sm3+ phosphors in white LEDs for indoor health lighting. These results indicate that NaYTiO4:Dy3+,Sm3+ multifunctional phosphors are promising dual functional luminescent platforms that can be used for non-contact optical thermometers and white LED device applications. [ABSTRACT FROM AUTHOR]

Solid-state phosphor-converted white light-emitting diodes (pc-WLEDs) are the leading trend of the lighting industry in the 21st century. To pursue high quality WLED lighting, the development of highly efficient phosphors with tunable luminescence has become a hot research topic. Herein, we reported for the first time on Bi3+/Eu3+-doped Li3Ba2Y3(WO4)8 phosphors that exhibited tunable emission and high energy transfer efficiency of 89.90% from Bi3+ to Eu3+. The phase purity, microstructure, electronic structure and photoluminescence properties of these phosphors were studied in detail. Bi3+ and Eu3+ were effectively doped in Li3Ba2Y3(WO4)8 with an optical bandgap of 3.81 eV. The band structure and density of states were quantitatively evaluated by density functional theory simulation. At an excitation wavelength of 342 nm, the Bi3+-doped phosphor achieved yellow-green emission. By alloying Eu3+ into Li3Ba2Y3(WO4)8:Bi3+, the luminescence gradually turned red due to the energy transfer from Bi3+ to Eu3+. Moreover, the activation energy of the prepared phosphor was 0.1897 eV, demonstrating excellent thermal stability. Eventually, by combining Li3Ba2Y3(WO4)8:4%Bi3+,4%Eu3+ and a blue-emitting BAM:Eu2+ phosphor with a 365 nm ultraviolet chip, a WLED device with a high colour rendering index (Ra) of 78.7, chromaticity coordinates of (0.3401, 0.3131) and correlated colour temperature of 5080 K was successfully achieved. This work provided new insights into the design and development of color-tunable phosphors for white LEDs. [ABSTRACT FROM AUTHOR]

Research into red phosphors with a high color rendering index is particularly compelling, given the absence of a red component in the spectrum of commercial pc-WLEDs, which combine blue LED chips with yellow-emitting YAG:Ce3+ phosphors. Herein, we reported a novel Eu3+ activated Ca3Zn3Te2O12 red-emitting phosphor, synthesized using a conventional high-temperature solid-phase method. The phase and crystal structures were analyzed by powder X-ray diffraction and Rietveld refinement. The optimal excitation peak of the Ca3Zn3Te2O12:Eu3+ phosphor was located at 395 nm, matching those of conventional commercial near-ultraviolet chips. In addition, the Ca3Zn3Te2O12:9%Eu3+ phosphor exhibited good thermal stability, with an activation energy of 0.267 eV, and the CIE color coordinates hardly changed with temperature. Ultimatel, a high-quality white LED device was fabricated by combining Ca3Zn3Te2O12:9%Eu3+ red phosphor, a commercial BaMgAl10O17:Eu2+ blue phosphor, and(Ba,Sr)2SiO4:Eu2+ green phosphor with a 395 nm near-UV chip. Despite a substantial increase in the input current from 20 to 320 mA, the white-LED maintained a stable color rendering index of around 80, highlighting its consistent performance. These results indicated that Eu3+ activated Ca3Zn3Te2O12 phosphors are promising red emission candidates for white LEDs pumped by near ultraviolet chips. [ABSTRACT FROM AUTHOR]

RNA helicase DDX21 plays vital roles in ribosomal RNA biogenesis, transcription, and the regulation of host innate immunity during virus infection. How DDX21 recognizes and unwinds RNA and how DDX21 interacts with virus remain poorly understood. Here, crystal structures of human DDX21 determined in three distinct states are reported, including the apo‐state, the AMPPNP plus single‐stranded RNA (ssRNA) bound pre‐hydrolysis state, and the ADP‐bound post‐hydrolysis state, revealing an open to closed conformational change upon RNA binding and unwinding. The core of the RNA unwinding machinery of DDX21 includes one wedge helix, one sensor motif V and the DEVD box, which links the binding pockets of ATP and ssRNA. The mutant D339H/E340G dramatically increases RNA binding activity. Moreover, Hill coefficient analysis reveals that DDX21 unwinds double‐stranded RNA (dsRNA) in a cooperative manner. Besides, the nonstructural (NS1) protein of influenza A inhibits the ATPase and unwinding activity of DDX21 via small RNAs, which cooperatively assemble with DDX21 and NS1. The structures illustrate the dynamic process of ATP hydrolysis and RNA unwinding for RNA helicases, and the RNA modulated interaction between NS1 and DDX21 generates a fresh perspective toward the virus–host interface. It would benefit in developing therapeutics to combat the influenza virus infection. [ABSTRACT FROM AUTHOR]

In many cancers, microRNA-193a (miR-193a) is a suppressor miRNA, but its underlying anti-oncogenic activity in breast cancer is not known. In this study, we found decreased miR-193a (specifically, miR-193a-5p) expression not only in breast cancer cell lines but also in breast cancer tissues as compared with the adjacent non-tumor tissues. Ectopic miR-193a overexpression inhibited the proliferation, colony formation, migration, and invasion of MDA-MB-231 and BT549 cells. miR-193a reduced Wilms’ tumor 1 (WT1) expression and repressed luciferase reporter activity by binding WT1 coding region sequences; mutation of the predicted miR-193a binding site abolished this effect. miR-193a and WT1 expression were significantly inversely correlated in breast cancer tissues. Importantly, the anti-cancer activity induced by miR-193a was partially reversed by WT1 overexpression, indicating an important role for WT1 in such activity related to miR-193a. Our results reveal that miR-193a-WT1 interaction plays an important role in breast cancer metastasis, and suggest that restoring miR-193a expression is a therapeutic strategy in breast cancer. [ABSTRACT FROM AUTHOR]

A series of Ca3Y(GaO)3(BO3)4:Tb3+,Eu3+ phosphors were prepared by a high-temperature solid-state reaction. Their phase structures were confirmed by powder X-ray diffraction and the element distribution was measured using transmission electron microscopy elemental mapping. The photoluminescence emission and excitation spectra and fluorescence lifetime were studied and discussed in detail. The results revealed that Eu3+ ions can be efficiently sensitized by Tb3+ ions under near-UV excitation. In addition, the energy transfer efficiency can be controlled by adjusting the ratio of Eu3+ and Tb3+ to realize colour tunable emission from green to red. For Ca3Y(GaO)3(BO3)4:0.50Tb3+,0.10Eu3+, the emission intensity at 425 K is 78.11% of that at 300 K, being available to near-UV LEDs. [ABSTRACT FROM AUTHOR]

The oncogenic protein ARHGEF5/TIM has long been known to express specifically in human breast cancer and other tumors, which is an important member of Rho guanine nucleotide exchange factors that activate Rho-family GTPases by promoting GTP/GDP exchange. The activation capability of TIM is auto-inhibited by a putative helix N-terminal to Dbl homology (DH) domain, which is stabilized by intramolecular interaction of Src homology 3 domain with a poly-proline sequence that locates between the helix and DH domain. Here, we attempted to target TIM DH domain using the modified versions of its auto-inhibitory helix. In the procedure, bioinformatics techniques were used to investigate the intramolecular interaction of DH domain with auto-inhibitory helix and, based on obtained knowledge, to optimize physicochemical property and structural conformation for the helix. We also performed affinity assay to determine the binding strength of modified peptides to DH domain. Consequently, two modified peptides, namely, DALYEEYNLVV and EVLYEEYQLVV were found as good binders of DH domain with dissociation constants K of 0.35 and 2 µM, respectively. Structural analysis revealed that the charge neutralization and electrostatic interaction confer additional stability for these two peptide complexes with DH domain. [ABSTRACT FROM AUTHOR]

For drilling with oil-based mud, the oil slurry and film attached on wellbore or casing wall affect severely the cementing quality of the interface. To improve the compatibility between cement sheath and well surfaces, as well as increase the interface cementing quality, a preflush system BCS-020L was developed. The BCS-020L provides good compatibility with drilling mud and spacer fluid, and can effectively remove the oil-based drilling mud attached to the well and casing wall, with high cleaning efficiency, higher than 80%. Also, the BCS-020L could change cementing interface effectively from oil wet to water wet, and improve the cementing quality of interface efficiently. The preflush system BCS-010L has been successfully applied on Well LIUPING 1 in Yumen Oilfield with excellent cementing quality. [ABSTRACT FROM AUTHOR]

Catalytic hydrolysis of ammonia borane (AB) has been considered as an effective and safe method to generate hydrogen. Development of highly active and low-cost catalysts is one of the key tasks for this technology. In this work, hexagonal CuCo2O4 nanoplatelets with a thickness of approximately 55 nm were prepared. In AB hydrolysis, those nanoplatelets exhibited ultrahigh catalytic activity with turnover frequency (TOF) of 73.4 molhydrogen min−1 molcat−1. As far as we know, this is one of the highest TOF values ever reported for non-noble metal catalysts. In addition, the effects of viscosity and different alkalis on the hydrolysis were also investigated. It is revealed that high viscosity of the reaction medium will retard the hydrolysis reaction. The presence of NaOH, KOH, and Na2CO3 in the reaction solution is favorable for hydrolytic process. In contrast, NH3·H2O will slow down the hydrolysis rate of ammonia borane. This work can provide some novel insight into the design of catalysts with both high performance and low cost. Besides, some findings in the present study can also offer us some information about how to improve the hydrolysis rates by optimizing the hydrolysis condition. [ABSTRACT FROM AUTHOR]