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A series of Li+, Na+, or K+, Tm3+, and Yb3+ co-doped Bi2WO6 upconversion phosphors were prepared by a high-temperature solid-phase method at 800°C for 3 h. X-ray diffraction showed that Li+, Na+, K+, Tm3+, and Yb3+ doping did not affect the orthorhombic structure of the Bi2WO6 matrix. Scanning electron microscopy images of the Bi2WO6:1% Tm3+, 6% Yb3+ and 1% Li+, 1% Na+, or 1% K+-doped Bi2WO6:1% Tm3+, 6% Yb3+ samples reveal irregular particles with a 0.5–5 µm particle size range; upon Na+ or K+ doping, the particle size increases and the particle surface becomes smooth. EDS analysis shows that the above ions are well incorporated into the powder particles. At 298 K, the relative temperature sensitivities are 0.00144, 0.0016, 0.0024, and 0.0018 K−1 for the 1% Tm3+, 6% Yb3+:Bi2WO6 samples without alkali metal ions and doped with 1% Li+, 1% Na+, or 1% K+ based on the thermally coupled energy level 3F3/3F2 characterization temperature. However, under the same conditions, when using the nonthermally coupled level 3F3/1G4 characterization temperature, the relative temperature sensitivities of these four samples are 0.0378, 0.0166, 0.046, and 0.0257 K−1, increasing by 26.3, 10.3, 19.1, and 13.9 times, respectively. The relative temperature sensitivities of the 1% Na+, 1% Tm3+, and 6% Yb3+:Bi2WO6 samples are the highest at 298 K.

Background: Cholangiocarcinoma (CCA) is a malignant tumor of the gastrointestinal tract with a poor prognosis. Immunotherapy plays an important role in the treatment of CCA. This study aimed to investigate the research hotspots and trends in immunotherapy for CCA. Methods: The Web of Science Core Collection was searched for literature related to CCA immunotherapy research from January 1, 2014, to December 31, 2023, and features such as country, institution, authors, references, and keywords in the included literature were quantitatively and visually analyzed using the VOS viewer and CiteSpace software. Results: A total of 252 English publications published between 2014 and 2023 were included. The publications were mainly from China and the United States, with Fudan University being the institution that published the most papers. The highest number of publications came from Frontiers in Oncology. The most prolific authors were Jia Fan, Jian Zhou from China and Pa-Thai Yenchitsomanus from Thailand, while the Journal of Clinical Oncology ranked first in the number of citations among the co-cited journals. In recent years, the focus of research has shifted from "immune checkpoint" and "chemotherapy" to "immunotherapy combined therapy." Currently, the research frontiers are "microenvironment," "immune cells," and "macrophages." Conclusion: Our study analyzes the research hotspots and trends in CCA to provide a knowledge map of immunotherapy research, which will serve as a reference and direction for future research. [ABSTRACT FROM AUTHOR]

Ho3+ and Yb3+-codoped Bi2WO6 upconversion luminescent materials at different concentrations were prepared via a high-temperature solid-phase method. The X-ray diffraction patterns showed that Ho3+ and Yb3+ doping basically did not affect the orthorhombic crystal system structure of the Bi2WO6 matrix material. Scanning electron microscopy images showed that 3%Ho3+,10%Yb3+:Bi2WO6 consisted of irregular bulk particles with sizes in the range of 0.5–2 μm and some powder agglomeration. SEM mapping and EDS measurements of the powder showed that the elements were relatively uniformly distributed. Under 980 nm excitation, the emission intensity of Ho3+ was the largest for the 3%Ho3+- and 10%Yb3+-doped sample. With an excitation power ranging from 45 mW to 283 mW for the 3%Ho3+,10%Yb3+:Bi2WO6 sample, the relationship between the luminescence intensity and pump power was determined; the results indicated that the Ho3+ (538 nm, 546 nm, 660 nm, 756 nm) emission peaks originated from two-photon absorption. In the temperature range of 298 K–573 K, under 980 nm laser excitation, the maximum absolute temperature sensitivity Sa was 0.029% K−1 (373 K), the maximum relative temperature sensitivity Sr was 0.034% K−1 (348 K) for the Ho3+ thermally coupled energy levels 5F4/5S2, and the minimum temperature resolution δT was 1.2857 K (298 K). Under the same conditions, the maximum Sa was 51.02% K−1 (573 K), the maximum Sr was 1.85% K−1 (523 K) for the Ho3+ nonthermally coupled energy levels 5F5/5F4, and the minimum δT is 0.2477 K (448 K). The colour coordinates showed that the luminescence of the 3%Ho3+,10%Yb3+:Bi2WO6 sample gradually shifted from the green region to the red region with increasing temperature. [ABSTRACT FROM AUTHOR]

Ho3+ and Yb3+-codoped Bi2WO6 upconversion luminescent materials at different concentrations were prepared via a high-temperature solid-phase method. The X-ray diffraction patterns showed that Ho3+ and Yb3+ doping basically did not affect the orthorhombic crystal system structure of the Bi2WO6 matrix material. Scanning electron microscopy images showed that 3%Ho3+,10%Yb3+:Bi2WO6 consisted of irregular bulk particles with sizes in the range of 0.5–2 μm and some powder agglomeration. SEM mapping and EDS measurements of the powder showed that the elements were relatively uniformly distributed. Under 980 nm excitation, the emission intensity of Ho3+ was the largest for the 3%Ho3+- and 10%Yb3+-doped sample. With an excitation power ranging from 45 mW to 283 mW for the 3%Ho3+,10%Yb3+:Bi2WO6 sample, the relationship between the luminescence intensity and pump power was determined; the results indicated that the Ho3+ (538 nm, 546 nm, 660 nm, 756 nm) emission peaks originated from two-photon absorption. In the temperature range of 298 K–573 K, under 980 nm laser excitation, the maximum absolute temperature sensitivity Sa was 0.029% K−1 (373 K), the maximum relative temperature sensitivity Sr was 0.034% K−1 (348 K) for the Ho3+ thermally coupled energy levels 5F4/5S2, and the minimum temperature resolution δT was 1.2857 K (298 K). Under the same conditions, the maximum Sa was 51.02% K−1 (573 K), the maximum Sr was 1.85% K−1 (523 K) for the Ho3+ nonthermally coupled energy levels 5F5/5F4, and the minimum δT is 0.2477 K (448 K). The colour coordinates showed that the luminescence of the 3%Ho3+,10%Yb3+:Bi2WO6 sample gradually shifted from the green region to the red region with increasing temperature. [ABSTRACT FROM AUTHOR]

Er3+ and Yb3+ codoped Bi2WO6 upconversion luminescent materials with different concentrations were prepared via a high-temperature solid-phase method. The microstructure, upconversion luminescence and temperature sensing properties of the synthesized powders were analyzed. From the X-ray diffraction patterns, the doping of Er3+ and Yb3+ ions did not affect the orthorhombic crystal structure of the Bi2WO6 matrix material. From the scanning electron microscopy images, the morphologies of the samples were inhomogeneous subspherical particles with a particle size range of 1–5 µm and some agglomeration. SEM-mapping and EDS analysis shows that each element is well distributed in the sample powder particles. At 980 nm excitation, the strongest upconversion emission of Er3+ was obtained when 1.5% Er3+ and 0.5% Yb3+ were codoped, and the four emission peaks of Er3+ were enhanced with increasing excitation pump power from 50 to 500 mW. The relationship between the excitation pump power and the emission intensity of Er3+ was determined, and all four emission peaks of Er3+ were obtained from two-photon absorption. The temperature was characterized by fluorescence intensity ratio of the nonthermally coupled energy levels (4F9/2, 4S3/2) of Er3+ in the range of 298 K to 573 K, and a maximum absolute temperature sensitivity of 0.0736 K−1 at 573 K and a maximum relative temperature sensitivity of 0.0503 K−1 at 298 K were obtained and were 15.8 and 4.1 times higher than the temperature sensitivity under the thermal coupling energy level (2H11/2, 4S3/2) characterization, respectively. The temperature resolutions under the above thermally coupled and nonthermally coupled energy level pair characterizations were calculated to be 0.07 K and 0.05 K at 333 K, respectively. [ABSTRACT FROM AUTHOR]

Ho 3+ and Yb 3+ -codoped Bi 2 WO 6 upconversion luminescent materials at different concentrations were prepared via a high-temperature solid-phase method. The X-ray diffraction patterns showed that Ho 3+ and Yb 3+ doping basically did not affect the orthorhombic crystal system structure of the Bi 2 WO 6 matrix material. Scanning electron microscopy images showed that 3%Ho 3+ ,10%Yb 3+ :Bi 2 WO 6 consisted of irregular bulk particles with sizes in the range of 0.5-2 μm and some powder agglomeration. SEM mapping and EDS measurements of the powder showed that the elements were relatively uniformly distributed. Under 980 nm excitation, the emission intensity of Ho 3+ was the largest for the 3%Ho 3+ - and 10%Yb 3+ -doped sample. With an excitation power ranging from 45 mW to 283 mW for the 3%Ho 3+ ,10%Yb 3+ :Bi 2 WO 6 sample, the relationship between the luminescence intensity and pump power was determined; the results indicated that the Ho 3+ (538 nm, 546 nm, 660 nm, 756 nm) emission peaks originated from two-photon absorption. In the temperature range of 298 K-573 K, under 980 nm laser excitation, the maximum absolute temperature sensitivity S a was 0.029% K -1 (373 K), the maximum relative temperature sensitivity S r was 0.034% K -1 (348 K) for the Ho 3+ thermally coupled energy levels 5 F 4 / 5 S 2 , and the minimum temperature resolution δ T was 1.2857 K (298 K). Under the same conditions, the maximum S a was 51.02% K -1 (573 K), the maximum S r was 1.85% K -1 (523 K) for the Ho 3+ nonthermally coupled energy levels 5 F 5 / 5 F 4 , and the minimum δ T is 0.2477 K (448 K). The colour coordinates showed that the luminescence of the 3%Ho 3+ ,10%Yb 3+ :Bi 2 WO 6 sample gradually shifted from the green region to the red region with increasing temperature.