Multifunctional CaF2: Yb3+, Ho3+, Gd3+ Nanocrystals: Insight into Crystal Growth and Properties of Upconversion Luminescence, Magnetic, and Temperature Sensing Properties.

The upconversion (UC) emission intensity of Ln3+-doped CaF2 nanomaterials is not ideal, which limits their application in some advanced scientific fields. Hence, it is extremely imperative to enhance the emission intensity of UC nanocrystals. In this work, an ionic-liquid-assisted hydrothermal method based on an ethylene glycol (EG) and ionic liquid (IL) two-phase system was used to synthesize CaF2 doped with Yb3+ and Ho3+. The influence of the amount of IL and the reaction time as well as the concentration of Gd3+ doping on morphology and size was studied in detail, and the growth mechanism was proposed. Green UC luminescence materials were obtained through co-doping Yb3+ and Ho3+ ions. Furthermore, the luminescence of UC was increased monotonically with the introduction of Gd3+ ions. The effect mechanism of Gd3+ doping on the UC luminescence was put forward, which might provide a new method for the promotion of UC luminescence. In addition, the temperature sensing of CaF2: Yb3+/Ho3+/Gd3+ was investigated, which demonstrated that the phosphor has a potential application prospect in thermal sensing. Meanwhile, CaF2: Yb3+/Ho3+/Gd3+ also exhibited a paramagnetic property at room temperature. Therefore, these multifunctional nanocrystals may have prospective applications in optical bioimaging, magnetic resonance imaging, and temperature sensing.

Systematic Study on the Luminescent Properties, Thermal Stability, and Magnetic Behavior of GdOF: RE3+ (RE = Eu, Yb, and Er) Red Phosphors with Various Morphologies.

In this work, GdOF:RE3+ (RE = Eu, Yb, and Er) phosphors with high thermally stable luminescence were reported, which were synthesized by an ionic liquid-assisted two-phase system and subsequent calcination technique for the first time. Nanodisks, nanorod aggregates, nanoneedles, and stubby nanorods were obtained by simply regulating the pH value. The luminescent properties of precursors and products were discussed in detail. By carefully adjusting the calcination temperature and the pH value of the initial system, pure red emission was achieved in both GdOF:Eu3+ and GdOF:Yb3+, Er3+ phosphors. The reason for distinct luminescent properties of different products was discussed from various perspectives. Moreover, the temperature-dependent spectra were measured and the GdOF:Eu3+ and GdOF:Yb3+, Er3+ products both exhibited outstanding thermal stability. In addition, the as-prepared nanomaterials presented paramagnetic properties, indicating their potential application in both field-emission displays and magnetic resonance imaging technology.

Exploiting heterologous and endogenous CRISPR-Cas systems for genome editing in the probiotic Clostridium butyricum.

Clostridium butyricum has been widely used as a probiotic for humans and food animals. However, the mechanisms of beneficial effects of C. butyricum on the host remain poorly understood, largely due to the lack of high-throughput genome engineering tools. Here, we report the exploitation of heterologous Type II CRISPR-Cas9 system and endogenous Type I-B CRISPR-Cas system in probiotic C. butyricum for seamless genome engineering. Although successful genome editing was achieved in C. butyricum when CRISPR-Cas9 system was employed, the expression of toxic cas9 gene result in really poor transformation, spurring us to develop an easy-applicable and high-efficient genome editing tool. Therefore, the endogenous Type I-B CRISPR-Cas machinery located on the megaplasmid of C. butyricum was co-opted for genome editing. In vivo plasmid interference assays identified that ACA and TAA were functional protospacer adjacent motif sequences needed for site-specific CRISPR attacking. Using the customized endogenous CRISPR-Cas system, we successfully deleted spo0A and aldh genes in C. butyricum, yielding an efficiency of up to 100%. Moreover, the conjugation efficiency of endogenous CRISPR-Cas system was dramatically enhanced due to the precluding expression of cas9. Altogether, the two approaches developed herein remarkably expand the existing genetic toolbox available for investigation of C. butyricum.

SiO2:Tb3+@Lu2O3:Eu3+ Core-Shell Phosphors: Interfacial Energy Transfer for Enhanced Multicolor Luminescence.

Uniform and well-dispersed SiO2:x%Tb3+@Lu2O3:y%Eu3+ core-shell spherical phosphors were synthesized via a solvothermal method followed by a subsequent calcination process. The structure, phase composition, and morphology of the samples were studied by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that the Lu2O3:Eu3+ layer was evenly coated on the surface of SiO2:Tb3+ spheres and the shell thickness was about 45-65 nm. The PL spectra and fluorescence lifetimes of the samples were further studied. It was proved that the multicolor luminescence of the samples could be realized by changing the doping concentration ratio of Eu3+ or by changing the excitation wavelengths. Compared with SiO2@Lu2O3:3%Tb3+,6%Eu3+, SiO2:3%Tb3+@Lu2O3:6%Eu3+ showed stronger luminescence intensity, longer fluorescence lifetime, and higher energy transfer efficiency, which was attributed to the effective interfacial energy transfer, and the interfacial energy transfer mechanism from Tb3+ to Eu3+ was a dipole-dipole interaction mechanism. The XPS results indicated that the sample contained a high content of Si-O-Lu bonds, which proved that there was a strong interaction between the SiO2 core and the Lu2O3 shell, making the interfacial energy transfer possible. These results provided a new idea for luminescence enhancement and multicolor luminescence.

Ca(Mg0.8Al0.2)(Si1.8Al0.2)O6:Ce3+,Tb3+ Phosphors: Structure Control, Density-Functional Theory Calculation, and Luminescence Property for pc-wLED Application.

A modified structure Ca(Mg0.8Al0.2)(Si1.8Al0.2)O6 (denoted as CMASO) from the evolution of CaMgSi2O6 (denoted as CMSO) codoped with Ce3+ and Tb3+ ions was designed successfully by solid reaction method for application in phosphor-converted white-light-emitting diode (pc-wLED). The Rietveld refinement of these two structures verified the changes derived from the replacement of some of the Mg2+ and Si4+ ions by Al3+ ions. The band gaps were calculated by density-functional theory (DFT) calculation method to verify the change of Al3+ ions replacing further, and the diffuse reflectance spectra (DRS) proved the veracity of the calculation result. The phosphors CMASO:Ce3+ showed blue emission excited by a wider excitation wavelength from 280 nm to 370 nm. The change of structure lead to the absorbable range broaden and the emission peak shifted to longer wavelength, compared with CMSO:Ce3+, although the amount of emitting center was the same. The reason for these phenomena was discussed in detail. The codoped phosphors CMASO:Ce3+,Tb3+ exhibited different emission colors from blue to green as the concentration of Tb3+ ions increased. Combined with commercial red phosphor CaAlSiN3:Eu2+ and ultraviolet LED (UV-LED) chips, the selected appropriate samples achieved white emission. The correlated color temperature (CCT) was 6137 K and the color rendering index (Ra) was 80.5, indicating that they could act as potential phosphors for possible applications in pc-wLED.

Whole-genome and Transcriptome Sequencing of Prostate Cancer Identify New Genetic Alterations Driving Disease Progression.

BACKGROUND: Global disparities in prostate cancer (PCa) incidence highlight the urgent need to identify genomic abnormalities in prostate tumors in different ethnic populations including Asian men. OBJECTIVE: To systematically explore the genomic complexity and define disease-driven genetic alterations in PCa. DESIGN, SETTING, AND PARTICIPANTS: The study sequenced whole-genome and transcriptome of tumor-benign paired tissues from 65 treatment-naive Chinese PCa patients. Subsequent targeted deep sequencing of 293 PCa-relevant genes was performed in another cohort of 145 prostate tumors. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The genomic alteration landscape in PCa was analyzed using an integrated computational pipeline. Relationships with PCa progression and survival were analyzed using nonparametric test, log-rank, and multivariable Cox regression analyses. RESULTS AND LIMITATIONS: We demonstrated an association of high frequency of CHD1 deletion with a low rate of TMPRSS2-ERG fusion and relatively high percentage of mutations in androgen receptor upstream activator genes in Chinese patients. We identified five putative clustered deleted tumor suppressor genes and provided experimental and clinical evidence that PCDH9, deleted/loss in approximately 23% of tumors, functions as a novel tumor suppressor gene with prognostic potential in PCa. Furthermore, axon guidance pathway genes were frequently deregulated, including gain/amplification of PLXNA1 gene in approximately 17% of tumors. Functional and clinical data analyses showed that increased expression of PLXNA1 promoted prostate tumor growth and independently predicted prostate tumor biochemical recurrence, metastasis, and poor survival in multi-institutional cohorts of patients with PCa. A limitation of this study is that other genetic alterations were not experimentally investigated. CONCLUSIONS: There are shared and salient genetic characteristics of PCa in Chinese and Caucasian men. Novel genetic alterations in PCDH9 and PLXNA1 were associated with disease progression. PATIENT SUMMARY: We reported the first large-scale and comprehensive genomic data of prostate cancer from Asian population. Identification of these genetic alterations may help advance prostate cancer diagnosis, prognosis, and treatment.

Novel highly efficient single-component multi-peak emitting aluminosilicate phosphors co-activated with Ce3+, Tb3+ and Eu2+: luminescence properties, tunable color, and thermal properties.

A series of emission-tunable Ce3+/Tb3+/Eu2+ doped Ca2(Mg0.75Al0.25)(Si1.75Al0.25)O7 (denoted as CMAS) phosphors have been synthesized via a high temperature solid-state reaction method. The luminescence properties, color tuning, quantum yields (QYs), energy transfer of Ce3+ to Tb3+/Eu2+, thermal stability, performance of LED devices and ratiometric temperature sensing application have been systematically investigated, respectively. Importantly, through the study of thermal stability, we found that Ce3+ and Tb3+ co-doped samples were suitable for WLED applications, while Ce3+ and Eu2+ co-doped samples were suitable for temperature sensing applications. Due to the energy transfer, Ce3+/Tb3+ co-doped samples had high luminous efficiency and the quantum efficiency of more than 80% could be achieved. Their emission colors can modulate from blue to green. In addition, on the basis of the evaluation of the as-fabricated white LED lamps via selecting the corresponding phosphors, the CCT can reach 4275 K and the CRI can increase to 86.8, indicating that this series of phosphors can act as potential color-tunable phosphors for possible applications in ultraviolet light based white LEDs. Importantly, it is found that the fluorescence intensity ratio of CMAS : 5%Ce3+,0.5%Eu2+ displays linear correlation with temperature in a wide range of 253-373 K with a high sensitivity of 2.49% K-1, indicating that it could be a good candidate for ratiometric optical thermometry.

The photoluminescence, thermal properties and tunable color of Na1-xAl1+2xSi1-2xO4:xCe3+/Tb3+/Dy3+via energy transfer: a single-component multicolor-emitting phosphor.

A series of emission-tunable Na1-xAl1+2xSi1-2xO4:xCe3+/Tb3+/Dy3+ phosphors were synthesized via a high temperature solid-state reaction method. Luminescence properties, energy transfer from Ce3+ to Tb3+ or Dy3+ ions, color tuning and thermal stability were systematically investigated. Particularly, the charge compensating defect generated by doping of rare earth ions was remedied through Al3+ substituted Si4+. Meanwhile, the emission intensity was significantly improved. The presence and content of various elements were demonstrated through data combined with the crystallographic data from Rietveld refinements and the analysis of SEM and mapping for each element. The results indicated that this charge balance strategy was an effective method. The energy transfer from Ce3+ to Tb3+ and Dy3+ in the co-doped NaAlSiO4 (NAS) samples was deduced from the spectral overlap between the Ce3+ emission and Tb3+/Dy3+ excitation spectra, the photoluminescence spectra and the fluorescence decay curves. The energy transfer mechanisms of Ce3+ to Tb3+ and Dy3+ in the host were studied. And the emission hue can be tuned from blue to green and yellow by properly varying the ratio of Ce3+ and Tb3+/Dy3+. Additionally, the temperature-dependent photoluminescence of the as-prepared phosphors was investigated in detail. All these properties indicate that the developed phosphor may potentially be used as a single-component multicolor-emitting phosphor for UV light-emitting diodes.

Facile synthesis and color-tunable properties of BaLuF5:Ce,Tb,Eu(Sm) submicrospheres via a facile ionic liquid/EG two-phase system.

BaLuF5:Ce,Tb,Eu(Sm) submicrospheres were synthesized via an ILs/ethylene glycol(EG) two-phase system. The crystalline phase, size, morphology, and luminescence properties were characterized using powder X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra. The results show that 1-methyl-3-octylimidazolium hexafluorophosphate ([Omim]PF6) was used as fluoride source and capping agent to tune morphology and size of the crystals. The formation mechanism has been supposed. Under the excitation of ultraviolet, the BaLuF5:5%Ce3+,5%Tb3+, BaLuF5:Eu3+, and BaLuF5:5%Ce3+,5%Sm3+ exhibit green and red emission, which was derived from Tb3+, Eu3+, and Sm3+ emission. When codoping Ce3+, Tb3+, Sm3+ or Eu3+ together, multi-color emission can be realized. Furthermore, this synthetic route may have potential applications for fabricating other lanthanide fluorides.

Dynamic microwave-assisted extraction coupled with salting-out liquid-liquid extraction for determination of steroid hormones in fish tissues.

In this work, a simple and fast sample pretreatment method was proposed for determination of steroid hormones in fish tissues by coupling dynamic microwave-assisted extraction with salting-out liquid-liquid extraction. The steroid hormones were successively extracted with acetonitrile and water under the action of microwave energy. Subsequently, the extract was separated into an acetonitrile phase and an aqueous phase with ammonium acetate. The acetonitrile phase containing the target analytes was concentrated and determined by LC-MS/MS. The limits of detection for the steroid hormones were in the range of 0.03-0.15 ng g(-1). This method was successfully applied to analyze seven kinds of fish tissues, and the recoveries of the steroid hormones for the spiked samples were in the range of 75.3 ± 4.9% to 95.4 ± 6.2%. Compared with the traditional method, the proposed method could reduce the consumption of the organic solvent, shorten the sample preparation time, and increase the sample throughput.

[Determination of five kinds of trace elements in Mongolian medicines by microwave digestion-ICP-AES].

With the combination of the microwave digestion and ICP-AES, and by optimizing the instrument conditions, the micro digestion-ICP-AES method for the determination of eight metal elements, Zn, Fe, Ca, Mn, K, Mg, Sr and Na, in Mongolian medicines has been established. This method works by determining one solution sample with many kinds of elements at one time. The average recovery of the method is between 92.2% and 113.3% and the RSD is between 0.4% and 3.2%. The accuracy and precision of the method was tested by comparing the values of GBW070602. The determination results were found to be basically consistent with the reference values, which means the test result is reliable.