Search

The luminescent properties of BaTi(BO3)2:Eu3+ red phosphor were significantly improved by utilizing the charge compensation of the alkali metal Na+ ion, and a wide color gamut pc-WLED was successfully prepared using the BaTi(BO3)2:Eu3+,Na+ phosphor.

Exploring and designing new luminescent host with rich resource is beneficial to reducing the cost and the large-scale application of luminescent materials. Herein, a series of novel Eu3+-activated KNa5Ca5(CO3)8 red-emitting phosphors with different Eu3+ concentrations were successfully synthesized under mild hydrothermal condition. XRD and SEM characterizations show that all as-prepared KNa5Ca5(CO3)8:Eu3+ samples crystallize in a hexagonal structure, P63mc (No.186) space group, and show monodispersed hexagonal sheet morphologies, within a side length interval about of 2–3 μm and a thickness of about 0.6 μm. Eu3+ doping within 6 mol% concentration has little influence on the crystal structure of the host, as indicated by XRD, and FT-IR results, but thermal stability changes as shown by the TG-DTA. KNa5Ca5(CO3)8 phosphors with different Eu3+ concentrations can emit red-light under effectively excitation by near-UV light. CIE chromaticity coordinates of all KNa5Ca5(CO3)8:Eu3+ phosphors were calculated to locate in red region, and CCT of each sample is the range from 2815 to 3650 K, very close to the tungsten lamp light. Besides, concentration quenching phenomenon appearing at 5 mol% is found to be the result of electric multipolar interaction of Eu3+ activators, and the decay lifetime is about 1.63 ms, which almost unchanges with Eu3+ doping concentration. Importantly, thermal quenching analysis reveals good thermal stability with thermal activation energy of about 0.216 eV. The results reported here demonstrate that KNa5Ca5(CO3)8 is a promising fluorescent host for LEDs applications.

The present study aimed to explore the role of histone chaperone anti‑silencing function 1B (ASF1B) in pancreatic cancer and the underlying mechanism. The biological function of ASF1B was investigated in pancreatic cancer cell lines (PANC‑1 and SW1990) and a mouse xenograft model. Chromatin immunoprecipitation was used to detect the effect of ASF1B on the transcriptional activity of c‑Myc. ASF1B was highly expressed in pancreatic adenocarcinoma (PAAD) samples from The Cancer Genome Atlas. ASF1B expression was positively associated with poor survival rates in patients with PAAD. Silencing of ASF1B in PANC‑1 and SW1990 cells inhibited cell proliferation, migration and invasion, and induced apoptosis. Mechanistically, ASF1B increased H3K56 acetylation (H3K56ac) in a CREB‑binding protein (CBP)‑dependent manner. ASF1B promoted H3K56ac at the c‑Myc promoter and increased c‑Myc expression. In PANC‑1 and SW1990 cells, the CBP inhibitor curcumin and the c‑Myc inhibitor 10058‑F4 reversed the promoting effects of ASF1B on cell proliferation, migration and invasion. In the mouse xenograft model, ASF1B silencing inhibited tumor growth, and was associated with low H3K56ac and c‑Myc expression. ASF1B promoted pancreatic cancer progression by activating c‑Myc via CBP‑mediated H3K56ac.

Gallbladder cancer (GBC) is one of the leading causes of cancer-related mortality worldwide. Researchers have investigated that specific strains of bacteria are connected with growth of different types of cancers in human. Some reports show possible implication of Helicobacter pylori (H. pylori) in the etiology of gallbladder cancer (GBC). Their enigmatic mechanisms, nevertheless, are not still well clear. We sought to predict whether various proteins of H. pylori targeted to nucleus of host cells and their implication in growth of gallbladder cancer. GBC is one of the leading causes of cancer mortality worldwide. We applied bioinformatics approach to analyze the H. pylori proteins targeting into the nucleus of host cells using different bioinformatics predictors including nuclear localization signal (NLS) mapper Balanced Subcellular Localization (BaCelLo) and Hum-mPLoc 2.0. Various nuclear targeting proteins may have a potential role in GBC etiology during intracellular infection. We identified 46 H. pylori proteins targeted into nucleus of host cell through bioinformatics tools. These H. pylori nucleus-targeting proteins might alter the normal function of host cells by disturbing the different pathways including replication, transcription, translation etc. Various nucleus-targeted proteins can affect the normal growth and development of infected cells. We propose that H. pylori proteins targeting into the nucleus of host cells regulate GBC growth using different strategies. These integrative bioinformatics research demonstrated several H. pylori proteins that may serve as possible targets or biomarkers for early cure and treatment or diagnosis GBC.

High hepatitis B virus (HBV) DNA level is an independent risk factor for postoperative HBV-associated liver cancer recurrence. We sought to examine whether HBV DNA level and antiviral therapy are associated with survival outcomes in patients with advanced hepatocellular carcinoma (HCC) treated with anti-programmed cell death protein 1 (PD-1)based immunotherapy.This single-institution retrospective analysis included 217 patients with advanced HBV-related HCC treated from 1 June 2018, through 30 December 2020. Baseline information was compared between patients with low and high HBV DNA levels. Overall survival (OS) and progression-free survival (PFS) were compared, and univariate and multivariate analyses were applied to identify potential risk factors for oncologic outcomes.The 217 patients included in the analysis had a median survival time of 20.6 months. Of these HBV-associated HCC patients, 165 had known baseline HBV DNA levels. Baseline HBV DNA level was not significantly associated with OS (P = 0.59) or PFS (P = 0.098). Compared to patients who did not receive antiviral therapy, patients who received antiviral therapy had significantly better OS (20.6 vs 11.1 months, P = 0.020), regardless of HBV DNA levels. Moreover, antiviral status (adjusted HR = 0.24, 95% CI 0.094-0.63, P = 0.004) was an independent protective factor for OS in a multivariate analysis of patients with HBV-related HCC.HBV viral load does not compromise the clinical outcome of patients with HBV-related HCC treated with anti-PD-1-based immunotherapy. The use of antiviral therapy significantly improves survival time of HBV-related HCC patients.

Carbon nitride (C3N4) has attracted widespread attention in the photocatalysis field for its stability, facile preparation from low-cost materials, and outstanding visible-light activity. Exploring novel synthesis or modification approaches of C3N4 with excellent photocatalytic property is still a research hotspot in this area. Herein we report a high-yield synthesis of C3N4 and boron-doped C3N4 using the mixed salts KCl-NaCl-LiCl as solvent. Compared with C3N4 sample prepared by the traditional solid-state reaction method, the sample by the molten-salt process showed much better photocatalytic activity for the degradation of methyl orange solution under visible light, which should be originated from high crystallinity and large surface areas as demonstrated by XRD, TEM and BET results. Furthermore, the photocatalytic activity of the molten-salt prepared C3N4 samples was regulated by boron doping, and the best photocatalytic performance was found at the boron content of 0.5%. Moreover, the photoluminescence properties of the samples were also investigated. The relationship between the photoluminescent and photocatalytic performances of the samples were compared and discussed. We believe the synthetic approach reported here provides a new strategy toward the homogeneous doped C3N4-based materials.

Gallbladder cancer (GBC) is one of the leading causes of cancer-related mortality worldwide. Researchers have investigated that specific strains of bacteria are connected with growth of different types of cancers in human. Some reports show possible implication of Helicobacter pylori (H. pylori) in the etiology of gallbladder cancer (GBC). Their enigmatic mechanisms, nevertheless, are not still well clear. We sought to predict whether various proteins of H. pylori targeted to nucleus of host cells and their implication in growth of gallbladder cancer. GBC is one of the leading causes of cancer mortality worldwide. We applied bioinformatics approach to analyze the H. pylori proteins targeting into the nucleus of host cells using different bioinformatics predictors including nuclear localization signal (NLS) mapper Balanced Subcellular Localization (BaCelLo) and Hum-mPLoc 2.0. Various nuclear targeting proteins may have a potential role in GBC etiology during intracellular infection. We identified 46 H. pylori proteins targeted into nucleus of host cell through bioinformatics tools. These H. pylori nucleus-targeting proteins might alter the normal function of host cells by disturbing the different pathways including replication, transcription, translation etc. Various nucleus-targeted proteins can affect the normal growth and development of infected cells. We propose that H. pylori proteins targeting into the nucleus of host cells regulate GBC growth using different strategies. These integrative bioinformatics research demonstrated several H. pylori proteins that may serve as possible targets or biomarkers for early cure and treatment or diagnosis GBC.

Background To investigate high-risk HPV (hr-HPV) genotype distributions and the association between hr-HPV infection with severity of the cervical lesions in women with normal cytology. Methods In this cross-sectional study, the result of the hr-HPV test and biopsy of colposcopy of women with normal cytology from January 2012 to January 2019 were analyzed. The detection rate of high-grade squamous intraepithelial lesion (HSIL) and cervical cancer were calculated among different hr-HPV genotypes, viral load group, and age groups. Results Five thousand eight hundred eighty women were enrolled in this study. Overall, 59.97% had normal histological results, 19.32% had HSIL, and 1.07% had cervical cancer. The detection rate of HSIL or worse (HSIL+) in women with single HPV16(34.00%), HPV31(27.50%), HPV33(25.58%), and HPV52(20.88%) infection were higher significantly than single HPV18 (15.59%) infection, respectively. The HSIL+ detection rate between HPV16 single infection and multiple infections (excluding HPV18) was no significant difference (34% vs 35.47%, P = 0.638), contrary to HPV18(12.59% vs 21.67%, P = 0.022). In women without HPV16/18 infections, HSIL+ detection rates for single, double, and triple or more hr-HPV infections were 12.28, 20.31, and 37.50%, the risk of detection of HSIL+ significantly increasing. With the hr-HPV DNA load increases, the risk of detection of HSIL+ (χ2 = 91.01, P P = 0.016) increase. In age 60 group, HSIL+ detection rate were 24.80%、22.10%、19.59%、14.29, and 12.61%, respectively. Conclusion Women who have normal cytology with HPV 16/18/31/33/52/58 infections, multiple HPV infections and high viral load, have a higher detection rate of HSIL+.

Novel Eu3+-doped YVO4 hollow-like nanocrystals were constructed via initiating homogeneous precipitation followed by a hydrothermal treatment. The phase structure, microstructure, band gap, and fluorescence performance of the hollow-like nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Uv–Vis diffusion reflectance spectra (Uv–Vis), and photoluminescence spectroscopy (PL). The results showed that all prepared samples were well crystallized in tetragonal YVO4 structure regardless of the doping concentration of Eu3+ ions from 0 to 15 mol%. TEM showed that all samples are composed of hollow-like nanocrystals with average diameters of about 20 nm, exhibiting a large-scale uniform morphology. A linear lattice expansion was observed due to evenly distributed of Eu3+ ions in the YVO4 crystal lattice matrix. The bandgap energy Eg showed a red-shift below the doping level of 3 mol% of Eu3+ ions. More importantly, YVO4 nanocrystals with hollow-like structure have a higher quenching Eu3+ ions concentration up to 10 mol%, compared to 5 mol% of the bulk YVO4 host. Furthermore, the tunable color emission from blue to white to red can be achieved in hollow-like YVO4 nanocrystals by controlling the doping concentration of Eu3+ ions. The nanocrystals with hollow-like structure reported in this work are very important, which may pave a new route to better the yttrium orthovandate host and further realize color tunable emission for laser, optoelectronics, and biomedical applications.

The study analysed healthcare workers' (HCWs) knowledge, practices, and attitudes regarding coronavirus disease 2019 (COVID-19). A cross-sectional survey was conducted from February 4th to February 8th, 2020, involving a total of 1357 HCWs across 10 hospitals in Henan, China. Of those surveyed, 89% of HCWs had sufficient knowledge of COVID-19, more than 85% feared self-infection with the virus, and 89.7% followed correct practices regarding COVID-19. In addition to knowledge level, some risk factors including work experience and job category influenced HCWs' attitudes and practice concerning COVID-19. Measures must be taken to protect HCWs from risks linked to job category, work experience, working hours, educational attainment, and frontline HCWs.

Homogeneous doping of rare earth (RE) ions at atomic level is ideal for enhancing luminescence efficiency. Molten-salt synthesis facilitates crystal growth with improved phase-selectivity and dopant homogeneity. Herein, we present a facile and phase-selective synthesis of orthorhombic α-BiNbO4 and monoclinic β-BiNbO4 under Na2SO4-K2SO4 fluxes in the temperature range of 900 °C to 1050 °C. A series of Eu3+ doped BiNbO4 samples with different crystalline structures were obtained. The influences of Eu3+ doping on the crystal structure were systematicly investigated. α-BiNbO4 has a higher Eu3+-doping limit (>15 mol%) while β-BiNbO4 was unstable upon Eu3+ doping and gradually transformed into α-BiNbO4 with the increase of Eu3+ doping concentration. Moreover, all prepared Eu3+ doped BiNbO4 samples can be effectively excited by near-ultraviolet and blue light and exhibit intense red emissions due to the 5D0/7F2 transition of Eu3+ ions. In addition, the quenching concentration can reach above 10 mol% Eu3+ for both polymorphs. The temperature-dependent emission results revealed that α-BiNbO4 possesses a superior thermal stability with activation energy of 0.271 eV, larger than β-BiNbO4 with activation energy of 0.233 eV. The results reported here provide new insights into the understanding of polymorph-dependent property for photon down-conversion rare-earth luminescence of BiNbO4:Eu3+.

Rational design and construction of metastable structured materials is more and more attractive toward realizing novel functional devices. In this work, the synthesis of metastable scheelite-type CdW1-xMoxO4 solid solution in the entire compositional range (0 ≤ x ≤ 1) was achieved for the first time. XRD, FT-IR and Raman spectroscopies confirmed that all the solvothermal prepared samples were pure tetragonal scheelite structure without wolframite phase. Structural refinement data revealed a lattice expansion with the substitution of W6+ by Mo6+ ions. UV–Vis diffuse reflectance spectra indicated that band gap energy of the solid solutions reduced with the replacement of W6+ by Mo6+ ions. Moreover, SEM analyses found that morphologies of the solid solution changed with the compositions. Meanwhile, the influences of chemical composition on the photoluminescent and electrical properties of the scheelite-type CdW1-xMoxO4 solid solution were also investigated. The reported synthetic strategy may applied to other metastable structures while the results reported will help to understand the structure and structure-property relations of scheelite-type ABO4 compounds.

The Ras-association domain family (RASSF) proteins have been involved in many important biological processes. RASSF7 is recently reported to be up-regulated in several types of cancer. However, the function of RASSF7 remain unknown in human cancers. To explore the role of RASSF7 in hepatocellular carcinoma (HCC) cells proliferation and molecular mechanism. RASSF7 expression was examined using public database TCGA, qRT-PCR and Western blot. The correlation between RASSF7 and clinicopathological features was measured. Overexpression and silencing of RASSF7 were performed to measure the impact on HCC cell proliferation, cell cycle and apoptosis. Futhermore, the molecular mechanism of MEK1/2-ERK1/2 signaling pathway regulation by RASSF7 was explored. RASSF7 was significantly up-regulated in HCC tissues and cell lines, and correlated with AFP, poor tumor histology and T stage. Overexpression of RASSF7 promoted HCC cell proliferation, drived G1-S phase cell cycle transition and inhibited apoptosis. Knockdown of RASSF7 suppressed cell growth, induced G1-S phase cell cycle arrest and cell apoptosis. Furthermore, our findings also demonstrated that RASSF7 promoted HCC cell proliferation through activating MEK1/2-ERK1/2 signaling pathway. Taken together, this study provides a novel evidence for clinical significance of RASSF7 as a potential biomarker, and demonstrates that RASSF7- MEK1/2-ERK1/2 signaling pathway might be a novel pathway involved in HCC progression.

A novel single trivalent Eu ion activated multicolor tunable langbeinite-type phosphor KBaIn2(PO4)3:Eu3+ (abbreviated to KBIP:Eu3+) was successfully synthesized through solid-state reaction. XRD was used to identify the phase of the as-prepared KBIP:Eu3+ phosphor, which proved that the phosphor was pure phase. The refined results showed that In3+ ions occupied two different sites in the KBIP host lattice. The PL spectra shows that the KBIP:Eu3+ phosphor has two luminescent centers, so Eu3+ ions can replace In3+ ions with two different positions. With the change of doping concentration, Eu3+ ions have different occupation orientations in the two sites, and tunable luminescence occurs at different excitation wavelengths. Besides, the morphology, molecular structure and optical properties of the KBIP:Eu3+ phosphors were studied. It is found that the sample crystallizes completely, and the band gap minishes from 2.67 eV to 2.36 eV with the increase of Eu3+ doping content. The fluorescence intensity at 150 ℃ is 65.5% of that at room temperature, and the calculated activation energy is 0.20 eV. The simple LED device test shows that the color rendering index of the phosphor is high (Ra = 92.4%), which greatly improves the red index R9. Therefore, the reported phosphors have great potential application in pc-WLEDs in the future.

This work explores the phase transition and its impact on photoluminescent properties of metastable scheelite-type, with and without Eu 3+ doped, CdWO 4 nanophosphors. A series of scheelite structure CdWO 4 :xEu 3+ (x = 0, 0.025, 0.05, 0.075, 0.10) samples were synthesized using a simple solvothermal method. The X-ray diffraction results indicate that the prepared samples were single phase in a tetragonal scheelite-type structure, and completely transformed into pure monoclinic wolframite structure after sintering at 450 °C for 2 h. It was revealed by Rietveld analysis that Eu 3+ doping induced a lattice contraction of both scheelite and wolframite CdWO 4 structures. The impact of Eu 3+ doping on the crystal structure and the band structure were further probed by FT-IR, Raman and UV–Vis spectroscopy. SEM images show that the morphology of the prepared samples also changed in the phase transition and the Eu 3+ doping processes. All samples showed a broad multi-color luminescence emission in the range from 400 to 640 nm under 280 nm excitation. The relative intensities of the blue-green emission originated from CdWO 4 matrix and the red emission ascribed to Eu 3+ can be regulated by both the crystal structure and Eu 3+ doping levels. The energy transfer process between WO 4 groups in scheelite structure CdWO 4 and WO 6 groups in wolframite structure CdWO 4 and Eu 3+ was discussed in detail based on the photoluminescent excitation and emission spectra. The synthetic approach reported here allows the control over CdWO 4 polymorphs and this kind of luminescent material has wide applications in white-LED, chemosensors and bioimaging.

The bismuth layered-structure Sr 1-x Ca x Bi 2 Ta 2 O 9 (SCBT) and Eu 3+ doped Sr 1-x Ca x Bi 2 Ta 2 O 9 solid solutions (0 ≤ x ≤ 1) have been synthesized by molten salt synthesis (MSS). X-Ray diffraction (XRD) characterizations showed that an unlimited solid solution with orthorhombic structure was formed in the x range from 0 to 1.0. Scanning electron microscopy (SEM) showed that the prepared samples presented regular nanosheets with a thickness of 100 nm. The structure evolutions of the solid solution were investigated by Fourier transform infrared spectra (FT-IR), UV–Vis spectrum and transmission electron microscopy (TEM) images. X-ray photoelectron spectroscopy (XPS) result showed that only Eu 3+ was present in the Eu-doped SCBT solutions. Influences of the chemical composition on the photoluminescent and photocatalytic performance have been performed and discussed: In the composition range x = 0 to 0.6, intensities of emission exhibited increased values and x = 0.6 shows the best photoluminescent performance under both 397 and 464 nm excitation at room temperature. All the as-prepared nanosheets showed a long lifetime in the range from 1.30 to 1.60 ms, depending on chemical composition. The photocatalytic activity for the degradation of methylene blue (MB) under UV-light was also varied with the chemical composition.

Background Pancreatic cancer (PC) is one of the deadliest cancers about the digestive system. Recent researches have validated that long non-coding RNAs (lncRNAs) play vital roles in various cancers, while the function of LINC01006 in PC is rarely clarified. Aim of the study Investigation of the specific role of LINC01006 in PC. Methods LINC01006 expression was examined by RT-qPCR. CCK-8, EdU, transwell, wound healing, and western blot assays were carried out to explore the function of LINC01006 in PC. The interaction among LINC01006, miR-2682-5p and HOXB8 was verified by luciferase reporter, RIP and ChIP assays. Results The expression of LINC01006 was markedly upregulated in PC tissues and cells. Furthermore, LINC01006 knockdown inhibited PC cell proliferation, invasion and migration, and upregulation of LINC01006 led to the opposite results. Besides, miR-2682-5p expression was downregulated and negatively regulated by LINC01006 in PC. Meanwhile, LINC01006 could bind with miR-2682-5p in PC. Moreover, miR-2682-5p negatively regulated HOXB8 expression and there was a binding site between miR-2682-5p and HOXB8 in PC. Additionally, miR-2682-5p overexpression or HOXB8 knockdown rescued the promotive effects of LINC01006 upregulation on PC cell progression. Similarly, miR-2682-5p inhibition or HOXB8 overexpression countervailed the repressive role of LINC01006 downregulation in PC cell progression. In addition, the transcription factor HOXB8 could activate LINC01006 transcription in PC. Conclusions LINC01006 promotes cell proliferation and metastasis in pancreatic cancer via miR-2682-5p/HOXB8 axis, which may facilitate the treatment for PC.

Red phosphor is an indispensable component in the development of warm white light-emitting diodes (w-LEDs). However, most of the current red phosphors suffer from shortages of high cost, complex synthesis process and harsh preparation conditions. In this paper, a phosphate-based red emitting phosphor without rare earth doping has been investigated. A series of xMn4+ ions (x = 0.00, 0.02, 0.04, 0.06, 0.08, 0.10 mmol) doping BaSn(PO4)2 phosphors were prepared by solid-state reaction. According to the X-ray diffraction (XRD) data, the phosphor belongs to monoclinic structure (C12/m1). The XRD refinement results show that with the increase of Mn4+ ions doping concentration, the β angle in the cell parameters of BaSn(PO4)2:xMn4+ phosphor gradually decreases, which indicates that the crystal cell is distorted. The morphology, elemental composition and molecular structure of the phosphor were studied by SEM, XPS and FT-IR. The band gap of the BaSn(PO4)2 host obtained by diffuse reflectance spectroscopy is about 3.59 eV, and the band gap decreases gradually with the Mn4+ ions doping content. From the room temperature fluorescence spectra, it is found that the phosphor emits red light when the excitation wavelength is 468 nm, and concentration quenching occurs at the doping concentration of x = 0.06. When the temperature rises to 423 K, the emission intensity of the phosphor remains at 76.7% of the original intensity at room temperature, and the activation energy Ea is calculated to be 0.1261 eV, indicating that the phosphor has excellent thermal stability. These results indicate that BaSn(PO4)2:xMn4+ is an excellent red phosphor.

Design of a solid solution with tunable functionality is an attractive strategy toward realizing novel devices with multi-functionalities. In this work, a series of Ca1−xCdxWO4 solid solutions in the entire range 0 ≤ x ≤ 1 with tetragonal scheelite structure have been successfully prepared for the first time. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Fourier transform Raman (FT-Raman) spectroscopies indicated that all the nanocrystals have a tetragonal scheelite structure without wolframite phase. Structural refinement data revealed that the lattice volume decreased with the replacement of Ca2+ by Cd2+ ions. UV-Vis diffuse reflectance spectra indicated that optical band gap reduced with the replacement of Ca2+ by Cd2+ ions. Scanning electron microscopic (SEM) images showed that morphologies of the nanocrystals changed with the chemical compositions. The structure evolution of the solid solutions was further investigated by high-resolution transmission electron microscopy (HRTEM). Moreover, the influence of chemical compositions on the photoluminescent and electric performance has been performed and discussed. The reported synthetic approach and findings reported here are important to understand the structure and structure–property relation of scheelite-structured tungstate and molybdate compounds, which has potential applications in the design of other kinds of novel functional materials.

BiPO4 microspheres with three kinds of crystal phase (h-BiPO4, m-BiPO4 and n-BiPO4) were prepared by a facile hydrothermal-calcination process. The crystalline phase, microstructures and photoelectrochemical properties were studied by various techniques. The results indicated that h-BiPO4 could transform into m-BiPO4 at 600 °C. Interestingly, h-BiPO4 accompanied with a little bit of n-BiPO4 would transform into n-BiPO4. After UV irradiation for 2 h, conversion of 94.6% and a mineralization rate of 76.8% could be achieved on n-BiPO4 for photocatalytic degradation of bisphenol A, which is almost 1.33 times as high as that of m-BiPO4 and 3.14 times that of h-BiPO4. Moreover, the n-BiPO4 also displayed the highest photocatalytic activity for degradation of other phenols (phenol and p-chlorophenol) in water and gaseous benzene. The enhancement of activity could be attributed to the improvement of the photogenerated electron–hole separation efficiency, which would be conducive to the formation of active species (hydroxyl radicals (˙OH) and superoxide radicals (˙O2−)). The results suggest that n-BiPO4 shows potential applications as an efficient and stable photocatalyst for the photocatalytic decomposition of persistent organic pollutants in water and in the gas phase.

Present work focuses on the surface composition disorder, its origin and relevance to photoluminescent and photocatalytic properties of ZnWO 4 nanocrystals. ZnWO 4 nanoparticles were synthesized under solvothermal conditions, in which formic acid was employed for both the nonstoichiometry and kinetic size control. Nonstoichiometry ranging from 1.05 to 1.18 was originated from the surface Zn-rich disorder layer, as reflected by an excess of cation Zn 2+ in the X-ray photoelectron spectroscopy and a new Raman vibration mode at about 930 cm −1 and HR-TEM images. Surface Zn-rich disorder layer has shown a great impact on the structure and properties, including lattice expansion, band-gap narrowing, luminescence enhancement, as well as photocatalytic weakening effect. The investigation on surface composition disorder of multi-component oxides is helpful to deeply understand their formation process and further to find a new functionality optimizing approach.

Despite the enormous efforts devoted to the research of titanium dioxide (TiO2), controlling TiO2 polymorphism, size and morphology still represents an interesting challenge since its stabilities, transitions and properties vary with them. Herein, we report a novel selective-synthesis of high purity anatase (A), rutile (R) and brookite (B) phase TiO2 from solution under mild hydrothermal conditions. By adjusting the concentrations of chloroacetic acid, urea and sodium hydroxide, A-TiO2 nanocrystals, R-TiO2 nanorods and B-TiO2 hollow spheres and nanorods can be easily produced as investigated by XRD and TEM characterisation. Based on time-varied experiments, two distinct phase transitions were observed under different hydrothermal conditions, namely the initially formed A-TiO2 nanocrystals would transform into R-TiO2 nanorods with augmented crystalline size under acidic conditions while they transformed into B-TiO2 hollow spheres under basic conditions. Moreover, polymorph formation and transition mechanism were explored in detail based on systematic investigation into the effects of synthetic parameters on the products. Finally, the spectra and photocatalytic properties of the three polymorphs were investigated and discussed. The synthetic approach reported here allows for full control over polymorph selection in TiO2 crystallization and provides new insights in this area.

Ion doping is one of the most effective ways to develop photocatalysts by creating impurity levels in the energy band structure. In this paper, novel Bi 3+ doped SrMoO 4 (SrMoO 4 :Bi 3+ ) nanocrystals were prepared by a simple hydrothermal method. By systematic characterizations using x-ray diffraction, infrared spectra, UV–vis spectra, X-ray photoelectron spectroscopy and transmission electron microscopy, it is demonstrated that all the samples crystallized in a single phase of scheelite structure, and particle sizes of SrMoO 4 :Bi 3+ gradually decreased. The Bi 3+ doped nanoparticles showed lattice contraction, and band-gap narrowing. The photocatalytic activity of the samples was measured by monitoring the degradation of methylene blue dye in an aqueous solution under UV-radiation exposure. It is found that SrMoO 4 :Bi 3+ showed excellent activity toward photodegradation of methylene blue solution under UV light irradiation compared to the pure SrMoO 4 . These observations are interpreted in terms of the Bi 3+ doping effects and the increased the surface active sites, which results in the improved the ratio of surface charge carrier transfer rate and reduced the electron–hole recombination rate. These results illustrate the potential of particle size and surface defect regulation for the construction of novel semiconductor oxide photocatalysts by ion doping.

In this paper, we constructed a novel Pt/Bi 12 O 17 Cl 2 composite through loading tiny amount of Pt quantum dots on the surface of Bi 12 O 17 Cl 2 by using photoreduction method at room temperature. The phase structures, morphologies, optical properties and elemental contents of the obtained samples were studied by XRD, EDS, ICP-OES, SEM, HRTEM, BET, UV–vis DRS and XPS technologies. The photocatalytic activity of novel Pt/Bi 12 O 17 Cl 2 was evaluated by degrading methyl orange (MO) and phenol under visible light (λ > 400 nm). It shows that Pt/Bi 12 O 17 Cl 2 exhibited largely enhanced activity in comparison with the pure Bi 12 O 17 Cl 2 , among which 15% Pt/Bi 12 O 17 Cl 2 sample displayed the fastest degrading rate for MO ( k app = 1.13 h −1 ) and phenol ( k app = 0.18 h −1 ). The excellent photocatalytic activity of Pt/Bi 12 O 17 Cl 2 resulted from the enhanced separation efficiency of photocharges, which is exactly ensured by the transient photocurrent and surface photovoltage investigation. The surface loaded Pt quantum dots acted as trappers to efficiently capture the photoinduced electrons originating from the Bi 12 O 17 Cl 2 substrate under visible light, which intensively avoids the recombination of electrons and holes. This study provides a potential way to boost the activity of bismuth oxyhalide with non stoichiometric ratios via utilizing the intense electron trapping effect of noble metal quantum dots.

A novel BiOI/Bi 12 O 17 Cl 2 heterojunction composite was fabricated via a facile deposition–precipitation method. The surface loading of a portion of BiOI strongly broadened the visible light absorption of Bi 12 O 17 Cl 2 from 500–600 nm. The photoelectric performance measurements show that the tightly contacted BiOI/Bi 12 O 17 Cl 2 heterojunction largely strengthened the spatial separation efficiency of photocharges under visible light. Furthermore, BiOI/Bi 12 O 17 Cl 2 applying to degrade two contaminant models, methyl orange (MO) and phenol, displayed much higher photocatalytic activity than the single Bi 12 O 17 Cl 2 and BiOI under visible light ( λ >400 nm). This is a successful Bi-based semiconductor composite photocatalytic system that can efficiently remove the organic contaminants in wastewater.

A new eulytite-type NaBaBi2(PO4)3:xEu3+ (NBBP:xEu3+) phosphors were synthesized via high temperature solid state reaction. The phase, composition, morphology, band structure, luminescence, electrical properties and thermal stability of the as-prepared NBBP:xEu3+ samples with various Eu3+ doping content were investigated in detail. XRD, structural refinement results show that the Eu3+ ions replace the Bi3+-site in the lattice. The morphology, elemental composition and molecular structure of the phosphor were studied by SEM, XPS and FT-IR. The band gap of the NaBaBi2(PO4)3 host obtained by diffuse reflectance spectroscopy is about 4.08 eV, and the Eu3+ ions doping has little effect on the band gap. Room temperature fluorescence spectra show that both near ultraviolet and blue light sources are the excitation pump sources of phosphors, and the electric dipole transition (5D0→7F2) at 611 nm dominates the red emission. With the increase of doping content, the fluorescence lifetime almost remains unchanged, and the CIE coordinates move to the red region, and the color purity also increases. When the temperature rises to 423 K, the emission intensity of the phosphor remains at 80% of the original intensity at room temperature, and the activation energy ΔE is calculated to be 0.175 eV, indicating that the phosphor has excellent thermal stability. It can be predicted that NBBP:Eu3+ phosphor has potential application in phosphor conversion white light-emitting diodes (pc-WLEDs).

The preparation of high-purity brookite TiO2 with a unique morphology is rare and difficult. Herein, high-purity brookite TiO2 hollow spheres were hydrothermally synthesized by employing titanium sulfate as the titanium source and chloroacetic acid and sodium hydroxide as the pH regulator. The structure, morphology, and optical properties were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS). The results showed that the as-prepared brookite TiO2 exhibited a hollow-sphere morphology with a size of about 1.0 micrometer and showed a direct band gap of 3.13 eV. Additionally, thermal analysis in combination with infrared spectroscopy showed that the as-prepared brookite TiO2 was surface capped by water and organic molecules. Finally, the photocatalytic and photoluminescent properties of brookite TiO2 were studied.

Exploring new luminescent host is important for spectral regulation purpose in this field since photoluminescent characteristics of RE ions are highly sensitive to the doping host. Herein, a new eulytite-type Pb3Bi(PO4)3:Eu3+ phosphor was synthesized via high temperature solid state reaction, and structure, luminescence properties and thermal stability were studied. It is known from XRD that the phosphor has a body-centered cubic structure and belongs to the I 4 ‾ 3d(220) space group. In this structure, one crystallographic site is mixed occupied by Pb and Bi atoms at the molar ratio of 3:1. In the effective excitation at 394 nm, all Pb3Bi(PO4)3:Eu3+ phosphors emitted bright red light and the color coordinates located at red region. Concentration quenching was not observed in the Eu3+ doping concentration within 10 mol%, and the fluorescence lifetime almost unchanged with the increase of doping concentration, indicating the host has a high quenching concentration. When the temperature is raised by 150 K, the emission intensity of the phosphor still retains 40% of the original intensity, and the activation energy Ea = 0.245 eV, indicating that the thermal stability of the phosphor is good. The above results demonstrated that the Pb3Bi(PO4)3:Eu3+ phosphors are very promising for use in blue and near-ultraviolet light excited w-LEDs.

Two new phosphate crystals, MZnAl(PO4)2 (M = Na, K), were successfully synthesized by high temperature solid state reaction method. NaZnAl(PO4)2 crystallizes in the triclinic centrosymmetric space group P-1 (No.2) with the unit cell parameters of a = 8.2050(9) A, b = 8.8142(9) A, and c = 9.4997(10) A, and Z = 4. KZnAl(PO4)2 crystallizes in the monoclinic centrosymmetric space group C2/c (No.15) with the unit cell parameters of a = 13.2906(7) A, b = 13.1956(8) A, and c = 8.6660(5) A, and Z = 8. The major structural characteristics of the two crystals are three-dimensional tunnel frameworks formed from ZnO4, AlO4 and PO4 tetrahedrons by sharing the oxygen atoms with the alkali metal atoms distributed in the tunnels. Interestingly, compared with the structures of MZnAl(PO4)2 (M = Na, K), it can be found that the structural symmetries show a gradually rising tendency from Na to K as a result of cation size effect of alkali metals. The results of UV–vis spectrum and IR spectra measurements indicate that NaZnAl(PO4)2 and KZnAl(PO4)2 have wide optical transmission ranges and large band gaps of 3.70 eV and 3.76 eV, respectively. The thermal analyses show that the two compounds have excellent thermal stability. AC complex impedance spectra were measured and fitted by the equivalent circuit, based on which the relatively low activation energies of 0.56 and 0.49 eV for NaZnAl(PO4)2 and KZnAl(PO4)2 were derived respectively, indicating that the tunnel structures can provide the ion channels and may be potentially used for alkali metal batteries and high temperature ionic conductors.

A series of I−-doped BiOBr (I-BiOBr) photocatalysts were prepared through adjusting the synthesis pH values of the reaction solution. The crystalline structure, light absorption, morphology and element component were measured by XRD, DRS, SEM, TEM, EDS, ICP-OES and XPS technologies. The doping of I− ions strongly broadened the visible light absorption range and improved the activity of I-BiOBr. More importantly, the photocatalytic activity of I-BiOBr dramatically depended on the synthesis pH values, in which I-BiOBr (0.5) displayed the best performance for removing methyl orange and phenol under visible light. The photoelectric property measurement revealed that I-BiOBr had stronger electron–hole separation efficiency than the corresponding BiOBr reference samples. With increase in the pH values, the I− ion doping contents varied a little but the surface charge state changed regularly. The decrease in the surface adsorbed negative Br− ions reduced the formation efficiency of active Br0 and resulted in low activity of I-BiOBr. This study provides a facile and efficient way to control the photocatalytic and photoelectric behaviors of novel I−-doped BiOX photocatalysts via changing the pH values of the reaction solution during synthesis.

AgI/Ag 3 PO 4 was successfully synthesized via a simple physical mixing process in the medium of water by using AgI microparticles and Ag 3 PO 4 nanospheres as precursors on the basis of a novel dissolution–precipitation strategy. The as-prepared AgI/Ag 3 PO 4 composite exhibited much higher activity than the pure AgI and Ag 3 PO 4 for eliminating methyl orange under visible light ( λ > 420 nm). The pseudo-first-order rate constant of methyl orange degradation over 75% AgI/Ag 3 PO 4 was 0.056 min −1 , which is 18.6 and 1.36 times higher than those over pure AgI and Ag 3 PO 4 . AgI/Ag 3 PO 4 heterostructure interface efficiently separated the photoinduced carriers and acquired excellent photocatalytic activity and stability. It provides a facile, fast and universal tactic to construct inorganic salts semiconductor composite photocatalysts based on the novel dissolution–precipitation strategy.

Objective To study the correlation between the expressions of stem cell factor (SCF) and hypoxia inducible factor 1 alpha (HIF-1α) in pancreatic cancer, and investigate the mechanism by which SCF regulates the expression of HIF-1α. Methods Immunohistochemistry was used to detect the expressions of SCF and HIF-1α in pancreatic cancer specimens and to analyze the correlation between SCF and HIF-1α expressions. Pancreatic cancer PANC-1 cells were treated with different doses of SCF (0, 1, 10, 100 ng/mL) alone or combined with c-KIT inhibitor Gleevec (5 μmol/L). Real-time fluorescent quantitative PCR (qRT-PCR) was performed to detect the level of HIF-1α mRNA, and Western blotting to detect the HIF-1α protein level, the phosphorylation levels of ERK1/2 and AKT. Results SCF and HIF-1α were up-regulated in pancreatic cancer samples and they had an obvious positive correlation. In PANC-1 cells, SCF didn't affect the expression of HIF-1α mRNA, but up-regulated the expression of HIF-1α protein in a dose-dependent manner. Gleevec inhibited the SCF-induced up-regulation of HIF-1α protein, but did not affect the mRNA. And Gleevec blocked the phosphorylation of AKT and ERK1/2. Conclusion SCF/c-KIT can up-regulate the protein expression of HIF-1α by activating AKT and ERK signaling pathways in pancreatic cancer cells.

Objective To investigate the effect of stem cell factor (SCF)/c-KIT system on the invasion of BxPC-3 pancreatic cancer cells and the role of hypoxia-inducible factor 1 alpha (HIF-1α) in this effect. Methods BxPC-3 cells were cultured in normoxia and hypoxia. The cells cultured in normoxia were treated with SCF. Real-time quantitative PCR and Western blotting were used to investigate the expressions of HIF-1α mRNA and protein, respectively. Small interference RNA of HIF-1α (siHIF-1α) was designed and synthesized, and then transfected into BxPC-3 cells. The expressions of matrix metalloproteinase-2 (MMP2), MMP9, and urokinase type plasminogen activator (uPA) were detected by real-time quantitative PCR and Western blotting in BxPC-3 cells after treated with SCF or siHIF-1α. The effects of SCF/c-KIT and HIF-1α knockdown on BxPC-3 cell invasion were examined by Transwell