Strategy for thermometry via Tm³âº-doped NaYF4 core-shell nanoparticles.

Optical thermometers usually make use of the fluorescence intensity ratio of two thermally coupled energy levels, with the relative sensitivity constrained by the limited energy gap. Here we develop a strategy by using the upconversion (UC) emissions originating from two multiplets with opposite temperature dependences to achieve higher relative temperature sensitivity. We show that the intensity ratio of the two UC emissions, ³F(2,3) and ¹G4, of Tm³âº in ß-NaYF4:20%Yb³âº, 0.5%Tm³âº/NaYF4:1%Pr³âº core-shell nanoparticles under 980 nm laser excitation exhibits high relative temperature sensitivity between 350 and 510 K, with a maximum of 1.53% K⁻¹ at 417 K. This demonstrates the validity of the strategy, and that the studied material has the potential for high-performance optical thermometry.

Pr(3+)-doped beta-NaYF4 for temperature sensing with fluorescence intensity ratio technique.

Pure beta-NaYF4:0.8%Pr3+ powder sample was synthesized by the hydrothermal method. The temperature dependence of the fluorescence intensity ratio (FIR) of emission bands corresponding to the 3P1 --> 3H5 and 3P0 --> 3H5 transitions was measured in the temperature range of 120 K to 300 K excited by a 473 nm continuous wave (CW) laser. The dependence of the FIR on temperature is well fitted with an exponential function and the effective energy difference obtained is 457 cm(-1), which gives further an absolute temperature sensitivity of 0.01352 K(-1) at 300 K. The monotonous increase of FIR with temperature and high absolute temperature sensitivity demonstrate that this material can be used as temperature sensor. In addition, mono-dispersed NaYF4:1%Pr3+ nanoparticles were also synthesized.

Synthesis and photoluminescent properties of NaYF4:Eu3+ core and NaYF4:Eu3+/NaYF4 core/shell nanocrystals.

NaYF4:Eu3+ core and NaYF4:Eu3+/NaYF4 core/shell nanocrystals (NCs) were synthesized via a wet chemical method. The transmission electron microscope photographs show that the core and core/shell nanoparticles are monodisperse and uniform NCs with average diameters of 22 and 26 nm respectively. The photoluminescence (PL) properties of the samples, including the PL excitation and emission spectra, and luminescent decay curves, are investigated in detail. The results show that the intensity of 5D2 emission relative to that of 5D0 is stronger in NaYF4:Eu3+/NaYF4 core/shell NCs than that in NaYF4:Eu3+ core NCs, and a longer decay lifetime of 5D2 is observed in core/shell samples. In addition, from the corrected emission spectra of 5D0, the 5D0 radiative lifetimes were calculated. These together with the measured decay lifetime of 5D0 emission give the intrinsic quantum yields of 5D0. The results were well interpreted by considering the surface effects.

Identification of key pathways and genes in nasopharyngeal carcinoma based on WGCNA.

OBJECTIVE: We aim to identify the potential genes and signaling pathways associated with the nasopharyngeal carcinoma (NPC) prognosis using Weighted Gene Co-Expression Network Analysis (WGCNA). METHODS: Gene Expression Omnibus (GEO) query was utilized to download two NPC mRNA microarray data. WGCNA was conducted on differentially expressed genes (DEGs) to obtain tumor-associated gene modules. Genes in core modules were intersected with DEGs for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analysis. GSE102349 dataset was devoted to identifying prognostic hub genes by survival analysis and the results were confirmed by quantitative polymerase chain reaction (qPCR). RESULTS: Co-expression networks were built, and we detected 12 gene modules. The Brown module and Magenta module were extremely associated with NPC samples. GO functional analysis and KEGG pathway analysis was carried out to the genes in the Brown and Magenta modules. Our data indicated that DEGs in Brown module and Magenta module were correlated with the biological regulation, metabolic process, reproduction, and cellular proliferation. Twenty-six hub genes were obtained and were considered to be closely related to NPC. GSE102349 dataset was devoted to identifying prognostic hub genes by survival analysis. The expression of IL33, MPP3 and SLC16A7 in GSE102349 dataset was significantly correlated with the progression-free survival (PFS). The results of qPCR indicated a strong correlation between SLC16A7 expression and the overall survival (OS). CONCLUSIONS: WGCNA contributed to the detection of gene modules and identification of hub genes and crucial genes. These crucial genes might be potential targets for pharmaceutic therapies with potential clinical significance.

High expression levels of FANCI correlate with worse prognosis and promote tumor growth of lung adenocarcinoma partly via suppression of M1 macrophages.

FANCI, a member of the Fanconi anemia (FA) complementation group, normally associates with FANCD2 to play an important role in ribosome biogenesis and DNA repair. However, the correlation of FANCI with prognostic value and the molecular mechanism in patients with lung adenocarcinoma (LUAD) remains unclear. In the present study, bioinformatics analysis was performed on LUAD data from TCGA and GEO databases, and further confirmed by in vitro experiments. We found that a high level of FANCI was significantly correlated with a worse survival probability in patients with LUAD. Moreover, the results from in vitro experiments revealed high levels of FANCI in LUAD specimens and cell lines. Knockdown of FANCI expression in A549 and H460 cells significantly inhibited cell viability and clone formation of LUAD cells in vitro and in vivo. Furthermore, high FANCI levels were negatively correlated with a variety of tumor-infiltrating immune cells. Importantly, the overexpression of FANCI significantly inhibited the activation of M1 macrophages. All the data demonstrated that FANCI was a useful prognostic biomarker in patients with LUAD, and knockdown of FANCI inhibited tumor growth of LUAD cells in vitro and in vivo, partly by suppressing the activation of M1 macrophages.

An effective polymer cross-linking strategy to obtain stable dispersions of upconverting NaYF4 nanoparticles in buffers and biological growth media for biolabeling applications.

Ligands on the nanoparticle surface provide steric stabilization, resulting in good dispersion stability. However, because of their highly dynamic nature, they can be replaced irreversibly in buffers and biological medium, leading to poor colloidal stability. To overcome this, we report a simple and effective cross-linking methodology to transfer oleate-stabilized upconverting NaYF(4) core/shell nanoparticles (UCNPs) from hydrophobic to aqueous phase, with long-term dispersion stability in buffers and biological medium. Amphiphilic poly(maleic anhydride-alt-1-octadecene) (PMAO) modified with and without poly(ethylene glycol) (PEG) was used to intercalate with the surface oleates, enabling the transfer of the UCNPs to water. The PMAO units on the phase transferred UCNPs were then successfully cross-linked using bis(hexamethylene)triamine (BHMT). The primary advantage of cross-linking of PMAO by BHMT is that it improves the stability of the UCNPs in water, physiological saline buffers, and biological growth media and in a wide range of pH values when compared to un-cross-linked PMAO. The cross-linked PMAO-BHMT coated UCNPs were found to be stable in water for more than 2 months and in physiological saline buffers for weeks, substantiating the effectiveness of cross-linking in providing high dispersion stability. The PMAO-BHMT cross-linked UCNPs were extensively characterized using various techniques providing supporting evidence for the cross-linking process. These UCNPs were found to be stable in serum supplemented growth medium (37 °C) for more than 2 days. Utilizing this, we demonstrate the uptake of cross-linked UCNPs by LNCaP cells (human prostate cancer cell line), showing their utility as biolabels.

Broadband downconversion in Bi3+, Yb3+-Co-doped YVO4 phosphor.

Yttrium vanadate phosphors co-doped with Bi3+ and Yb3+ ions have been prepared via the solid-state reaction. The phosphors were characterized by various methods including X-ray diffraction, photoluminescence excitation and photoluminescence spectra. Upon ultraviolet (UV) light excitation, an intense near-infrared (NIR) emission of Yb3+ corresponding to the transition of 2F(5/2) --> 2F(7/2) peaking at 985 nm was observed as a result of energy transfer from O2(-)-V5+ or Bi3+-V5+ charge transfer state (CTS) to Yb3+. A broad excitation band ranging from 250 to 375 nm was recorded when the Yb3+ emission was monitored, which suggests an efficient energy transfer from CTS to Yb3+ ions. The dependence of Yb3+ doping concentration on the visible emission, the NIR emission and decay lifetime has been investigated. The results of visible and NIR spectral evolution with temperature indicate that the mechanism for the NIR-emission is mainly phonon-assisted energy transfer at room temperature, while the mechanism is mainly cooperative energy transfer at low temperature. The YVO4:Bi3+, Yb3+ phosphor has prospects for realizing high efficiency crystalline Si solar cells by converting broadband UV energy into NIR light.

Energy transfer mechanisms in Yb3+-doped GdVO4 near-infrared downconversion nanophosphor.

Yb3+-doped GdVO4 nanophosphor was prepared by the co-precipitation method. Under ultraviolet (UV) light excitation, strong near-infrared (NIR) emission of Yb3+ (2F(5/2) --> 2F(7/2)) around 980 nm was observed. Owing to the host absorption of GdVO4, a broad excitation band ranging from 250 to 350 nm was recorded when the Yb3+ emission was monitored, which suggests an efficient energy transfer from the host to the Yb3+ ions. The concentration dependence of the visible vanadate emission and the Yb3+ emission was investigated. The decay curve of the vanadate emission was measured under the excitation of a 266 nm pulsed laser. The decay time of the vanadate emission at 500 nm was remarkably reduced by introducing Yb3+, further verifying that the energy transfer from the vanadate host to the Yb3+ ions was very efficient. Cooperative energy transfer (CET) is discussed as the possible energy transfer process. The temperature dependence of the emission intensity and decay time were also investigated for our further discussion.

[Preparation of Y2O3:Er3+ by coprecipitation method and influence of initial pH on the luminescent properties].

Samples of Y2O3:1%Er were prepared by coprecipitation method and the pH value of precipitant ammonium bicarbonate was adjusted by ammonia. Results of Fourier transform infrared spectra (FTIR) and elemental analysis showed that the chemical construction of precursors at pH range of 8.0-9.5 had little change. By X-ray fluorescence spectrometer (XRF) and scanning electron microscope (SEM) analysis, it was found that the pH value of precipitant had a significant impact on the content of erbium in precursor and it can influence particle size as well as its distribution of the products, both of which had important effects on the luminescent properties of the products.

[Preparation and luminescence of down-conversion material beta--NaYF4 : Tb3+, Yb3+].

NaYF4 : Tb3+, Yb3+ down-conversion (DC) phosphors were synthesized by hydrothermal method. X-ray diffraction (XRD), photoluminescence (PL) and photoluminescence excitation (PLE) spectra were used to characterize the samples. Experiment results revealed that samples of NaYF4 : Tb3+, Yb3+ crystallized in hexagonal shape without cubic shape. When the doping concentration of Tb3+ and Yb3+ was altered, the lattice structure of samples did not change, indicating that the Tb3+ and Yb3+ ions are completely dissolved in the NaYF4 host lattice by substitution for the Y3+. The emission from 5D4 --> 7F6 (489 nm), 5D4 --> 7F5 (542 nm), 5D4 --> F4 (584 nm), and 5D4 --> F3 (619 nm) of Tb3+ ions was observed, in which the dominant emission was at 542 nm. With single Tb3+ doping, no near-infrared (NIR) emission was observed under excitation of 355 nm pulsed laser. However, while with Tb3+ and Yb3+ codoping, the NIR emission at around 950 -1 100 nm from Yb3+ (2F5/2 --> 2F7/2) was observed under the same excitation. The dependence of the visible and NIR-emissions on Yb3+ doping concentration has been investigated. These results show that there is energy transfer process between Tb2+ and Yb3+. Furthermore, it is a possible DC process through cooperative energy transfer from Tb3+ to Yb3+. When the doping concentration is 1% mol Tb3+ and 6% mol Yb3+ respectively, the intensity of NIR emission reaches its strongest.

Expression and Biological Functions of EPC1 in Nasopharyngeal Carcinoma.

BACKGROUND: Comb homolog enhancer 1 (EPC1) gene is one of the important members of epigenetic inhibitor PCG family. It shows carcinogenic potential in a variety of malignant tumors, but the expression and role of EPC1 in nasopharyngeal carcinoma are unclear. The aim of this study was to explore the expression and function of enhancer of polycomb homolog 1 (EPC1) in nasopharyngeal carcinoma (NPC). METHODS: The differential expression of EPC1 in the cancer tissues and cell lines of NPC was examined by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). EPC1 expression, cell proliferation, and apoptosis were detected in NPC cell lines after EPC1 silencing, and the levels of the epithelial-mesenchymal transition (EMT)-related proteins E-cadherin and vimentin were detected in NPC cells after EPC1 silencing. The study was performed at Fujian Provincial Hospital, Fujian, China, from 2018 to 2019. RESULTS: We found that EPC1 was significantly upregulated in the cancer tissues and cell lines of NPC (P<0.001). Furthermore, knockdown of EPC1 inhibited the growth and metastasis of NPC cells. E-cadherin and vimentin were detected in NPC cells after EPC1 was knocked out. It was confirmed that inhibition of EPC1 resulted in increased E-cadherin expression (P<0.001) and decreased vimentin expression (P<0.001), suggesting that inhibition of EPC1 could inhibit the EMT in NPC cells. CONCLUSION: EPC1 expression was upregulated in NPC tissues and cell lines. Knockout of EPC1 effectively inhibited the growth of NPC cells, induced apoptosis, and inhibited invasion and metastasis. Inhibition of EPC1 could inhibit the EMT in NPC cells. All of the above findings support the viewpoint that EPC1 plays a pro-cancer role in NPC.

The clinical value of three-dimensional measurement in the diagnosis of thoracic myelopathy caused by ossification of the ligamentum flavum.

BACKGROUND: Thoracic ossification of the ligamentum flavum (OLF) is a major cause of thoracic myelopathy, which is often accompanied by multiple segmental stenosis or other degenerative spinal diseases. However, in the above situations, it is difficult to determine the exact segment responsible. The objective of this study was to analyze three-dimensional (3D) radiological parameters in order to establish a novel diagnostic method for discriminating the responsible segment in OLF-induced thoracic myelopathy, and to evaluate its superiority compared to the conventional diagnostic methods. METHODS: Eighty-one patients who underwent surgery for thoracic myelopathy caused by OLF from 2016 to 2020 were enrolled in this study as the myelopathy group, and 79 patients who had thoracic OLF but displayed no definite neurological signs from 2018 to 2020 were enrolled as the non-myelopathy group. We measured the one-dimensional (1D), two-dimensional (2D), and 3D radiological parameters, calculated their optimal cutoff values, and compared their diagnostic values. RESULTS: Significant differences were observed in the 1D, 2D, and 3D radiological parameters between the myelopathy and non-myelopathy groups (P<0.01). As a 3D radiological parameter, the OLF volume (OLFV) ratio (OLFV ratio = OLFV/normal canal volume × 100%) was the most accurate parameter for diagnosing OLF-induced thoracic myelopathy, with a diagnostic coincidence rate of 88.1%. We also found that an OLFV ratio of 26.3% could be used as the optimal cutoff value, with a sensitivity of 87.7% and a specificity of 88.6%. Moreover, the OLFV ratio [area under the curve (AUC): 0.92, 95% confidence interval (CI): 0.86-0.95] showed a statistically higher diagnostic value than the 1D and 2D parameters (AUC: 0.75, 95% CI: 0.67-0.81; AUC: 0.84, 95% CI: 0.77-0.89, respectively) (P<0.05). Pearson correlation analysis illustrated that the OLFV ratio was significantly negatively correlated with preoperative modified Japanese Orthopedic Association (mJOA) score (r=-0.73, 95% CI: -0.81 to -0.60, P<0.01). CONCLUSIONS: Our results demonstrate the superiority of the OLFV ratio over the conventional 1D and 2D computed tomography (CT)-based radiological parameters for the diagnosis of OLF-induced thoracic myelopathy. The novel diagnostic method based on the OLFV ratio will help to determine the responsible segment in multi-segmental thoracic OLF or when thoracic OLF coexists with other degenerative spinal diseases. The OLFV ratio also accurately reflects the clinical state of symptomatic patients with thoracic OLF.

A biomarker-based prediction model for risk of locoregional recurrence in pathologic stage IIIA-N2 non-small cell lung cancer.

OBJECTIVE: To investigate risk factors for locoregional recurrence (LRR) of pathologic stage IIIA-N2 non-small cell lung cancer (pIIIA-N2 NSCLC) and construct a prediction model for risk score to determine a patient's risk for LRR and guide the selection of postoperative radiotherapy (PORT). METHODS: The clinical, pathologic, and biological data of 107 patients with pIIIA-N2 NSCLC treated at Fujian Provincial Hospital between May 2012 and December 2018 were analyzed retrospectively. None of the patients had positive surgical margins, and none received preoperative treatment or PORT. The Kaplan-Meier method was used for a univariate analysis of possible factors for locoregional recurrence-free survival (LRFS). The Cox regression model was used in a multivariate analysis to identify independent risk factors for LRFS, which were used to construct a prediction model for risk score. The concordance index was calculated to evaluate discrimination. RESULTS: The median follow-up time was 31.2 months. During the follow-up, 69 (64.5%) patients had LRR and/or distant metastasis (DM). Among them, 46 (43%) patients had LRR (with or without DM), and 56 (52.3%) patients had DM (with or without LRR). The 1-year LRFS, distant metastasis-free survival, disease-free survival, and overall survival rates were 78.2%, 78%, 69.8%, and 90.2%, respectively; the 3-year rates were 50.6%, 41.2%, 31.2%, and 66.3%, respectively. Multivariate analysis showed that surgical approach (hazard ratio [HR], 0.348; 95% confidence interval [CI], 0.175-0.693; P = 0.003), metastatic N2 lymph node ratio (HR, 3.597; 95% CI, 1.832-7.062; P = 0.000), epidermal growth factor receptor status (HR, 3.666; 95% CI, 1.724-7.797; P = 0.001), and lymphocyte-to-monocyte ratio (HR, 2.364; 95% CI, 1.221-4.574; P = 0.011) were independent risk factors for LRFS. These independent risk factors were used to construct a prediction model for risk score and stratify patients into the low-risk group (risk score: 0-2), medium-risk group (risk score: 3-5), and high-risk group (risk score: 6-13). The 1-year LRFS rates of these groups were 91.9%, 85.3%, and 54.6%, respectively; the 3-year LRFS rates were 71.4%, 57.3%, and 13.6%, respectively. These between-group differences were significant (P = 0.000). The prediction model showed good discrimination (concordance index = 0.747, 95% CI, 0.678-0.816). CONCLUSION: Our prediction model for risk score based on characteristics of pIIIA-N2 NSCLC patients may help clinicians predict a patient's risk for LRR. Further investigations of PORT with patients in different risk groups are warranted.