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Y3−yAl5−xGaxO12:Ce3+y phosphors were prepared by high temperature solid state reaction method. The crystal structures, the influence of Ga3+ concentration on the photoluminescence (PL), cathodoluminescence, thermal stability and morphology of the phosphors were studied in detail. The results indicated that diffraction angle of the samples decreased gradually with the increase of Ga3+ ions content in XRD pattern. The emission peak of the spectra show a progressive blue-shift, the intensity increased first and then decreased and the optimal Ga3+ concentration in Y2.94Al5−xGaxO12:Ce3+0.06 phosphors is x = 0.75. The critical concentration of Ce3+ in YAGG:Ce3+ phosphors is affected with the ratio of Ga3+ to Al3+ and the Y2.9Al4.25Ga0.75O12:Ce3+0.1 phosphor showed the best performance on PL. However, the optimum concentration of Y3−yAl5−xGaxO12:Ce3+y phosphors is x = 1.5 and y = 0.04 when they were excited by cathode ray. [ABSTRACT FROM AUTHOR]

A novel tunable-light-emitting single-host Ca 12 Al 14 O 32 Cl 2 :0.5%Ce 3 + phosphor has been prepared in H 2 atmosphere by a solid-state reaction method. Upon 340 nm excitation, the phosphor shows an asymmetric broadband emission centered at 503 nm, assigned to the 5d - 4f transitions of Ce 3 + . For Ce 3 + doped Ca 12 Al 14 O 32 Cl 2 , a large red-shift (~ 69 nm) and an increased full width at half maximum from 66 to 115 nm can be observed in comparison with that of the Ce 3 + doped Ca 12 Al 14 O 33 sample. In particular, the emission color of the Ca 12 Al 14 O 32 Cl 2 :0.5%Ce 3 + phosphor can be tuned from blue to yellow by controlling anions in the nanocages, causing the different lattice deformations. Moreover, the CIE coordinates of the Ca 12 Al 14 O 32 Cl 2 :0.5%Ce 3 + phosphor move from yellow to blue as the heating temperature increases from 293 to 623 K. Our results suggest that the encaged-anion modulation in combination with the heating is an effective strategy for realizing highly color tunable emission of Ce 3 + doped in a single host, and furthermore, for designing novel phosphors for UV pumped multi-color LEDs and related devices. [ABSTRACT FROM AUTHOR]

Core–shell–shell heterostructures of α-NaLuF4:Yb/Er@NaLuF4:Yb@MF2 (M = Ca, Sr, Ba) have been successfully fabricated via the thermal decomposition method. Upconversion nanoparticles (UCNPs) were characterized by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), upconversion luminescence (UCL) spectroscopy, etc. Under 980 nm excitation, the emission intensities of the UCNPs are remarkably enhanced after coating the MF2 (M = Ca, Sr, and Ba) shell. Among these samples, CaF2 coated UCNPs show the strongest overall emission, while BaF2 coated UCNPs exhibit the longest lifetime. These results demonstrate that alkaline earth metal fluorides are ideal materials to improve the UCL properties. Meanwhile, although the lattice mismatch between the ternary NaREF4 core and the binary MF2 (M = Sr and Ba) shell is relatively large, the successfully synthesized NaLuF4:Yb/Er@NaLuF4:Yb@MF2 indicates a new outlook on the fabrication of heterostructural core–shell UCNPs. [ABSTRACT FROM AUTHOR]

Controlling excitation and emission wavelengths on demand is very significant in bioimaging. Up-conversion nanoparticles (UCNPs) emit visible light upon near-infrared (NIR) light excitation and are well studied in bioimaging. Red emission is usually preferred to green due to its higher tissue penetration depth in bioimaging. Herein, dominant red emission has been achieved under 808 nm excitation based on the designed α-NaYbF4:Mn2+/Er3+@NaLuF4:Mn2+/Yb3+@NaNdF4:Yb3+@NaGdF4 (C@S1@S2@S3) nanostructure. The rationally designed interlayer shell NaLuF4:Mn2+/Yb3+ could efficiently filter unwanted energy back-transfer from Er3+ to Nd3+ and the outmost shell NaGdF4 could prevent excitation energy from surface-related quenching. The lifetime of 4F9/2→4I15/2 transition of Er3+ could be as high as 0.7 ms. Moreover, C@S1@S2@S3 UCNPs also possess effective contrast efficiency for both X-ray computed tomography (CT) and magnetic resonance (MR) imaging. The designed multifunctional UCNPs could be used as a potential multimodal bioprobe in bioimaging applications. [ABSTRACT FROM AUTHOR]

Water-soluble lanthanide (Ln3+) doped Bi2O3 nanospheres have been successfully prepared through a solid-state-chemistry thermal decomposition process. The nanospheres exhibit intense upconversion luminescence (UCL) by doping the Ln3+ (Ln = Yb, Er/Ho/Tm) ions into the Bi2O3 host matrix under 980 nm excitation. The ratio of red/green emission of Bi2O3:Yb3+/Er3+ nanospheres exhibits a significant change as the calcination temperature increases and the value could reach 105.6. Moreover, the UCL of Bi2O3:Yb3+/Tm3+ nanospheres are temperature-sensitive, where the intensity ratios of 799 and 808 nm emissions increase monotonously with temperature. The MTT assay reveals that Bi2O3:Yb3+/Tm3+ nanospheres exhibit good biocompatibility by grafting citric acid molecules on the surface. The application possibility of Bi2O3:Yb3+/Tm3+ nanospheres as bioprobes for optical imaging in vivo is also confirmed by the high-contrast photoluminescence images between the background and the UCL imaging area. [ABSTRACT FROM AUTHOR]

Cubic KLu3F10 nanocrystals have been fabricated by doping Mn2+ ions via a liquid–solid solution (LSS) hydrothermal method. With an increase in the Mn2+ level, a phase transformation from orthorhombic KLu2F7 to cubic KLu3F10 associated with evolution of the particle morphologies and sizes is evident. The phase transformation mechanism based on doping with Mn2+ ions was studied via a series of time-controlled experiments and the enhancement of the intensity of upconversion luminescence (UCL) via doping with Mn2+ ions is discussed in detail. In addition, under 980 nm excitation, the UCL properties of Er3+/Tm3+/Ho3+-doped KLu3F10:Yb3+ upconversion nanoparticles (UCNPs) have been investigated and a possible UCL mechanism has been discussed. It has been demonstrated that cubic KLu3F10 is an excellent host for upconversion luminescence. [ABSTRACT FROM AUTHOR]

A multiphase strategy is proposed and successfully applied to make the insulating green phosphor CaCeAl3O7:Tb3+ conductive in the form of 12CaO·7Al2O3–CaCeAl3O7:Ce3+,Tb3+. The phosphor shows bright green-light emission with a short lifetime (2.51 ms) under low-voltage electron beam excitation (3 kV). The green photo- and cathodoluminescence from 5D4–7FJ (J = 6, 5, 4, 3) transitions of Tb3+ are significantly enhanced in comparison with pure C12A7:Tb3+. It was confirmed that this enhancement is the consequence of the joint effects of energy transfer from Ce3+ to Tb3+ and broadening of the absorption spectrum of Ce3+ due to the existence of multiple phases. In particular, under 800 V electron beam excitation, cathodoluminescence is improved by the modified electrical conductivity of the phosphor. When compared to the commercial Zn2SiO4:Mn2+ with a long luminescence lifetime of 11.9 ms, this conductive green phosphor has greater advantage for fast displays. [ABSTRACT FROM AUTHOR]

A new sand binder system cured by CO2 was prepared based on the animal bone glue. To overcome the disadvantages of animal glue such as agglomeration at room temperature, high energy consumption and low efficiency, an alkaline decomposition process was selected, and certain modifier was used to modify the performance of the animal glue binder. For the alkaline decomposition, NaOH was used as the catalyst with an addition of 4wt.% to the animal glue. A modifier was determined through the orthogonal experiment with a weight ratio of glycerin: glycol: dextrin: animal glue = 9:16:15:100, and the optimal modification reaction should be performed at 75° C with a reaction time of 90 min. Ca(OH)2 was used as a promoter; the optimal CO2 gas flux blowing into the sand was 0.7 m3-h-1 for a duration of 60 s under the experimental conditions. Results show that an original strength above 0.7 MPa and a final strength about 4.2 MPa can be achieved, which could meet the requirement of rapid moulding and core-making for foundry. The new binder was characterized and analyzed by means of IR, and the modification and CO2-cured mechanisms of this animal glue binder were also discussed. [ABSTRACT FROM AUTHOR]

The domestication of water played an important role in the emergence and development of settled societies. Although various features pertaining to groundwater use in the lower Yellow River area during the Neolithic and Bronze Age have been discovered, our knowledge about groundwater domestication in this area still remains fragmentary, due primarily to the large uncertainty in radiocarbon dating and calibration. For example, our previous attempt of radiocarbon dating of water well construction at an archaeological site situated on an alluvial fan was hindered by the Hallstatt radiocarbon plateau effect between 800 and 400 BC in the calibration curve, which also poses a great challenge to Bronze and early Iron Age archaeology elsewhere. Here we present more radiocarbon ages of charred millet grains from the primary fills of the water wells at this site and conduct age modeling using a hierarchical Bayesian model. Our results show that the wood lining technique in water well construction was first introduced to the lower Yellow River area sometime during 805–785 BC (68.2% credible interval). Groundwater use in this area may have lasted for about 240–380 years (68.2% credible interval). Comparing with proxy climate records suggests that the water wells may have been dug for securing drinking water when a cold and dry climate prevailed in the wake of the Bronze Age. [Display omitted] • We present evidence of groundwater domestication in the lower Yellow River area. • Wood lining technique in water well constructions was introduced to this area 805–785 BC. • Radiocarbon dating and Bayesian modeling can refine the Bronze Age archaeological timescale. • Water well construction represents a major technical innovation in human history. [ABSTRACT FROM AUTHOR]

Background. Several cancers, including lung adenocarcinoma (LUAD), are caused by genes related to necroptosis. However, it is still unknown how necroptosis-related long noncoding RNAs (lncRNAs) may be involved in LUAD. In order to predict the prognosis of LUAD patients and personalize immunotherapy, this study set out to construct a necroptosis-related lncRNA prognostic signature (NLPS). Methods. The Cancer Genome Atlas (TCGA) database was used to download the LUAD transcriptome data and the associated clinical data. lncRNAs associated with necroptosis were screened using coexpression analysis. An NLPS was built using univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses. The Gene Expression Omnibus (GEO) database's GSE30219 was used to validate the NLPS. The prognostic value of the risk score was assessed using Kaplan-Meier survival, receiver operating characteristic (ROC) Cox regression, multivariate Cox regression, and nomogram analyses. Then, we looked into the differences between the low- and high-risk groups in the tumor immune microenvironment, immunotherapy response, and half-maximal inhibitory concentration (IC50). Results. The 14 lncRNAs in a novel NLPS were created. With further validation in the GSE30219 dataset, the risk score according to the NLPS was an independent prognostic indicator for LUAD patients. Patients with better overall survival (OS) in the low-risk group, who were characterized by increased immune cell infiltration, tumor mutational burden (TMB), and immunophenoscore (IPS), may have hot tumors and higher immunotherapy response rates. In addition, the risk score was also closely linked to sensitivity to various anticancer medications. Conclusions. We constructed a novel NLPS that could predict OS and sensitivity to immunotherapy in LUAD patients. [ABSTRACT FROM AUTHOR]

BACKGROUND: Theabrownins (TBs) are one of most important quality components in dark tea, but have not been produced industrially. In this study, the aqueous extract was obtained from Pu‐erh ripe tea, one kind of dark tea. Caffeine, theaflavin, catechin and saponin were removed by trichloromethane, ethyl acetate and n‐butanol in turn to obtain a TB isolate. The TB isolate was subjected to column chromatography using a macroporous resin HPD‐750 and eluted with a gradient of 0–700 g kg−1 ethanol aqueous solution. Four fractions were obtained, and named as TBs‐FC1, TBs‐FC2, TBs‐FC3 and TBs‐FC4. RESULTS: These four fractions contained polysaccharides and no small molecules such as catechins, caffeine and theaflavins as well as average molecular weights of 123.000 kDa, 23.380 kDa, 89.870 kDa and 106.600 kDa. It was revealed that they were complexes of TBs and tea polysaccharide conjugates (TPCs). Ultraviolet‐visible (UV‐visible) and infrared (IR) spectra showed the properties of TBs and TPCs. Their zeta potentials ranged from −13.40 mV to −38.80 mV in aqueous solutions at pH 3.0–9.0. CONCLUSION: This study reveals that TBs do not exist in free state but in combined state in dark tea, which provide the theoretical basis for the industrialization of TBs. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Using ammonia as a precipitation agent, (Y,Gd) 2 O 3 :Tb3+ x ,Dy3+ y ,Tm3+ z phosphors were synthesized by the co-precipitation method. In order to improve the luminescence performance of the luminescent center Tb3+, Tb3+-Dy3+ co-doping and Tb3+-Dy3+-Tm3+ tri-doping were successively carried out, and the optimal component formulations were determined by the controlled variable method (x = 0.03, y = 0.005, z = 0.001). XRD results showed that the sample has a cubic phase Y 2 O 3 structure with good crystalline properties. SEM results revealed that the samples have a unique micro morphology of small ball aggregation. The effects of doping concentration of Dy3+ and Tm3+ on the luminescence properties of Tb3+ were systematically investigated. The energy transfer mechanism among the three ions of Tb3+-Dy3+-Tm3+ was demonstrated by photoluminescence spectroscopy, and the main interaction modes between ions were elucidated. In addition, the matrix lattice environment can change the thermal stability properties of phosphors. In this paper, the temperature characteristics of Y 2 O 3 :Tb3+,Dy3+,Tm3+ phosphors are expected to be changed by microtuning the Y 2 O 3 matrix lattice with the introduction of Gd3+. The fluorescence intensity ratio (FIR) and thermal sensitivity indicated that Gd3+ has good temperature sensitivity, and its introduction can effectively improve the temperature sensing performance of the phosphors, which has a wide range of applications in optical temperature measurement sensors. [Display omitted] In this paper, Y 2 O 3 :Tb3+ x ,Dy3+ y ,Tm3+ z phosphor was synthesized by co-precipitation method. The specific research is as follows: • To improve the luminescence intensity of Tb3+ as the experimental index, the optimal component formulations of the sample was determined by the controlled variable method: x = 0.03, y = 0.005, z = 0.001. • The energy transfer relationship between Tb3+-Dy3+-Tm3+ ions in a Y 2 O 3 matrix was explored. • The optical temperature sensing performance of Y 2 O 3 :Tb3+,Dy3+,Tm3+ phosphors was investigated before and after the introduction of Gd3+. [ABSTRACT FROM AUTHOR]

Research in functional asymmetry of Major Depressive Disorder (MDD) under different tasks is crucial for clinical diagnose. Fifty individuals with MDD and twenty healthy controls (HCS) were recruited for hemodynamic data collection under four fNIRS tasks (Emotional picture, Verbal fluency, Fingering and Negative emotional picture description task). Integral values and functional connectivity strength were employed to probe neural activation and functional connectivity in frontal and temporal lobes in MDD. Following, asymmetry characteristic of the frontal cortex between MDD and HCS under four tasks were carefully analyzed and compared. Individuals with MDD demonstrated heightened connectivity between the frontal and right temporal lobes and reduced connectivity between the frontal and left temporal lobes compared to HCS in all tasks. Additionally, MDD exhibited attenuated activation in the left frontal lobes and exaggerated activation in the right frontal lobes, diverging from HCS. Furthermore, the disparities in left-right asymmetry characteristic of frontal cortex activation between MDD and HCS were more pronounced during the combined task. Further research is required to grasp the neurophysiological mechanisms governing left-right asymmetry across various tasks and the influence of task-induced brain fatigue on cerebral cortex hemodynamics in MDD. The left-right asymmetry feature provides valuable neurophysiological insights for diagnosing MDD clinically. Variations in activation patterns and functional connectivity features between MDD and HCS are closely tied to the task chosen. Thus, in clinical practice, carefully selecting appropriate fNIRS tasks and relevant features can significantly improve the diagnostic accuracy of MDD. • Activation and functional connectivity of MDD under four fNIRS tasks were investigated. • A left-right asymmetry characteristics of frontal cortex was proposed to characterize MDD patients. • Task related characteristics for MDD patients were carefully compared and discussed. [ABSTRACT FROM AUTHOR]