Beneficial effects of maintaining liver function during hepatic arterial infusion chemotherapy combined with tyrosine kinase and programmed cell death protein-1 inhibitors on the outcomes of patients with unresectable hepatocellular carcinoma.

BACKGROUND AND AIM: Combination therapy is the primary treatment for unresectable hepatocellular carcinoma (u-HCC). The hepatic functional reserve is also critical in the treatment of HCC. In this study, u-HCC was treated with combined hepatic arterial infusion chemotherapy (HAIC), tyrosine kinase inhibitors (TKIs), and programmed cell death protein-1 (PD-1) inhibitors to analyze the therapeutic response, progression-free survival (PFS), and safety. METHODS: One hundred sixty-two (162) patients with u-HCC were treated by combination therapy of HAIC, TKIs, and PD-1 inhibitors. PFS was assessed by Child-Pugh (CP) classification subgroups and the change in the CP score during treatment. RESULTS: The median PFS was 11.7 and 5.1 months for patients with CP class A (CPA) and CP class B (CPB), respectively (p = 0.013), with respective objective response rates of 61.1 and 27.8% (p = 0.002) and conversion rates of 16 and 0% (p = 0.078). During treatment, the CP scores in patients with CPA worsened less in those with complete and partial response than in those with stable and progressive disease. In the CP score 5, patients with an unchanged CP score had longer PFS than those with a worsened score (Not reached vs. 7.9 months, p = 0.018). CPB was an independent factor negatively affecting treatment response and PFS. Patients with CPA responded better to the combination therapy and had fewer adverse events (AEs) than those with CPB. CONCLUSIONS: Thus, triple therapy is more beneficial in patients with good liver function, and it is crucial to maintain liver function during treatment.

Development and validation of nomograms to evaluate the survival outcome of HCC patients undergoing selective postoperative adjuvant TACE.

PURPOSE: The objective of this study was to develop and validate a novel prognostic nomogram to evaluate the survival benefit of hepatocellular carcinoma (HCC) patients receiving postoperative adjuvant transarterial chemoembolization (PA-TACE). MATERIALS AND METHODS: Clinical data of HCC patients who underwent hepatectomy at four medical centers were retrospectively analyzed, including those who received PA-TACE and those who did not. These two categories of patients were randomly allocated to the development and validation cohorts in a 7:3 ratio. RESULTS: A total of 1505 HCC patients who underwent hepatectomy were included in this study, comprising 723 patients who did not receive PA-TACE and 782 patients who received PA-TACE. Among them, patients who received PA-TACE experienced more adverse events, although these events were mild and manageable (Grade 1-2, all p < 0.05). Nomograms were constructed and validated for patients with and without PA-TACE using independent predictors that influenced disease-free survival (DFS) and overall survival (OS). These two nomograms had C-indices greater than 0.800 in the development cohort and exhibited good calibration and discrimination ability compared to six conventional HCC staging systems. Patients in the intermediate-to-high-risk group in the nomogram who received PA-TACE had higher DFS and OS (all p < 0.05). In addition, tumor recurrence was significantly controlled in the intermediate-to-high-risk group of patients who received PA-TACE, while there was no significant difference in the low-risk group of patients who received PA-TACE. CONCLUSION: The nomograms were developed and validated based on large-scale clinical data and can serve as online decision-making tools to predict survival benefits from PA-TACE in different subgroups of patients.

Regulating the upconversion luminescence properties of Tm3+/Yb3+-codoped ZrScW2PO12 microparticles with a negative thermal expansion effect through thermal stimulation for optical thermometry.

Tm3+/Yb3+-codoped ZrScW2PO12 microparticles were prepared in order to solve the problems of the severe thermal quenching and unsatisfactory thermometric properties of most luminescent materials. The synthesized materials exhibit a rarely observed negative thermal expansion (NTE) effect, which was verified by in situ X-ray diffraction experiments, performed under high temperature conditions. Upon excitation with a 980 nm laser, bright blue upconversion (UC) emissions originating from Tm3+ were observed. Moreover, owing to the promoted energy transfer, cross-relaxation and non-radiative decay processes at high temperatures triggered by the NTE effect, the observed UC emissions arising from 1G4 and 3F2,3 levels show non-monotonic responses to temperature. By analysing the temperature-dependent luminescence intensity ratio of these UC emissions originating from the non-thermally coupled levels of Tm3+ (1G4 and 3F2,3), the thermometric properties of the prepared microparticles were investigated in detail. Interestingly, the maximum absolute and relative sensitivities of the synthesized compounds are 0.09 and 1.45% K-1, respectively, which are independent of Yb3+ content, but they can be manipulated by employing different sensing modes. Our results manifest that the exploitation of the NTE effect is an efficient way to control the UC luminescence features of rare earth ions and to realize high performance optical thermometry.

Superior Energy Storage Capability and Fluorescence Negative Thermal Expansion of NaNbO3 -Based Transparent Ceramics by Synergistic Optimization.

Transparent dielectric ceramics are splendid candidates for transparent pulse capacitors (TPCs) due to splendid cycle stability and large power density. However, the performance and service life of TPCs at present are threatened by overheating damage caused by dielectric loss. Here, a cooperative optimization strategy of microstructure control and superparaelectric regional regulation is proposed to simultaneously achieve excellent energy storage performance and real-time temperature monitoring function in NaNbO3 -based ceramics. By introducing aliovalent ions and oxides with large bandgap energy, the size of polar nanoregions is continuously reduced. Due to the combined effect of increased relaxor behavior and fine grains, excellent comprehensive performances are obtained through doping appropriate amounts of Bi, Yb, Tm, and Zr, Ta, Hf in A- and B-sites of the NaNbO3 matrix, including recoverable energy storage density (5.39 J cm-3 ), extremely high energy storage efficiency (91.97%), ultra-fast discharge time (29 ns), and superior optical transmittance (≈47.5% at 736 nm). Additionally, the phenomenon of abnormal fluorescent negative thermal expansion is realized due to activation mechanism of surface phonon at high temperatures that can promote the formation of [Yb···O]-Tm3+ pairs, showing great potential in real-time temperature monitoring of TPCs. This research provides ideas for developing electronic devices with multiple functionalities.

Pressure-Induced Remarkable Spectral Red-Shift in Mn2+ -Activated NaY9 (SiO4 )6 O2 Red-Emitting Phosphors for High-Sensitive Optical Manometry.

To settle the low sensitivity of luminescent manometers, the Mn2+ -activated NaY9 (SiO4 )6 O2 red-emitting phosphors with splendid pressure sensing performances are developed. Excited by 408 nm, the resulting products emit bright red emission originating from 4 T1 (4 G) → 6 A1 transition of Mn2+ , in which the optimal concentration of the activator ion is ≈1 mol%. Moreover, the admirable thermal stability of the developed phosphors is studied and confirmed by the temperature-dependent emission spectra, based on which the activation energy is derived to be 0.275 eV. By analyzing the pressure-dependent Raman spectra, the structural stability of the synthesized compounds at extreme conditions is verified. Furthermore, the designed phosphors exhibit remarkable spectral red-shift at elevated pressure. Especially, as pressure increases from 0.75 to 7.16 GPa, the emission band centroid shifts from 617.2 to 663.4 nm, resulting in a high sensitivity (dλ/dP) of 7.00 nm GPa-1 , whereas the full width at half maximum (FWHM) increases from 83.0 to 110.6 nm, leading to the ultra-high sensitivity (dFWHM/dP) of 10.13 nm GPa-1 . These achievements manifest that the designed red-emitting phosphors are appropriate for ultrasensitive optical manometry. More importantly, the developed manometer is a current global leader in sensitivity, when operating in the band-width mode, that is, FWHM.

Development and Validation of a Nomogram for Predicting Postoperative Early Relapse and Survival in Hepatocellular Carcinoma.

BACKGROUND: Early relapse after hepatectomy presents a significant challenge in the treatment of hepatocellular carcinoma (HCC). The aim of this study was to construct and validate a novel nomogram model for predicting early relapse and survival after hepatectomy for HCC. PATIENTS AND METHODS: We conducted a large-scale, multicenter retrospective analysis of 1,505 patients with surgically treated HCC from 4 medical centers. All patients were randomly divided into either the training cohort (n=1,053) or the validation cohort (n=452) in a 7:3 ratio. A machine learning-based nomogram model for prediction of HCC was established by integrating multiple risk factors that influence early relapse and survival, which were identified from preoperative clinical data and postoperative pathologic characteristics of the patients. RESULTS: The median time to early relapse was 7 months, whereas the median time from early relapse to death was only 19 months. The concordance indexes of the postoperative nomogram for predicting disease-free survival and overall survival were 0.741 and 0.739, respectively, with well-calibrated curves demonstrating good consistency between predicted and observed outcomes. Moreover, the accuracy and predictive performance of the postoperative nomograms were significantly superior to those of the preoperative nomogram and the other 7 HCC staging systems. The patients in the intermediate- and high-risk groups of the model had significantly higher probabilities of early and critical recurrence (P<.001), whereas those in the low-risk group had higher probabilities of late and local recurrence (P<.001). CONCLUSIONS: This postoperative nomogram model can better predict early recurrence and survival and can serve as a useful tool to guide clinical treatment decisions for patients with HCC.

Pretreatment Neutrophil-to-Lymphocyte Ratio as Prognostic Biomarkers in Patients with Unresectable Hepatocellular Carcinoma Treated with Hepatic Arterial Infusion Chemotherapy Combined with Lenvatinib and Camrelizumab.

Purpose: This study aimed to assess the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with unresectable hepatocellular carcinoma (u-HCC) treated with hepatic artery infusion chemotherapy (HAIC) combined with lenvatinib and camrelizumab. Patients and Methods: We conducted a retrospective cohort study involving patients diagnosed with u-HCC who underwent HAIC combined with lenvatinib and camrelizumab. Patients were stratified into two cohorts using the median NLR as the cutoff point. We then assessed treatment response, overall survival (OS), progression-free survival (PFS), and adverse events in these patient groups. Results: Between October 2020 and April 2022, a total of 88 patients were enrolled in the study. The overall cohort exhibited a median PFS of 7.9 months, while the median OS was not reached, and a median NLR of 3.46. Notably, the group with NLR<3.46 demonstrated significantly superior OS (not reached vs 9.6 months, p = 0.017) and PFS (18.3 vs 5.3 months, p = 0.0015) compared to the NLR≥3.46 group. Furthermore, multivariate analysis revealed that an alpha-fetoprotein (AFP) ≥ 400 ng/mL [hazard ratio (HR), 2.133; 95% confidence interval (CI), 1.102-4.126; p = 0.024], Barcelona Clinical Hepatocellular Carcinoma (BCLC) stage C (HR, 2.319; 95% CI, 1.128-4.764; p = 0.022), and NLR ≥3.46 (HR, 2.35; 95% CI, 1.239-4.494; p = 0.009) were identified as independent risk factors for OS. Additionally, multivariate analysis demonstrated that AFP ≥ 400 ng/mL, BCLC stage C, and NLR ≥ 3.46 were independent negative factors of PFS. Conclusion: NLR can be associated with outcomes in patients with u-HCC treated with HAIC combined with lenvatinib and camrelizumab.

Manipulating the thermometric behaviors of Er3+/Yb3+/Ho3+-tridoped La2Mo3O12 polychromatic upconverting microparticles via adjusting spatial mode and a sensing strategy.

To meet the needs of contactless optical thermometry, Er3+/Yb3+/Ho3+-tridoped La2Mo3O12 (LMO) microparticles were designed and synthesized. Upon exciting with 980 nm light, the synthesized compounds emit glaring upconversion (UC) emissions and their emission colors can be tuned from green to yellow by altering the Ho3+ content. It is found that the optimal doping contents for Yb3+ and Ho3+ in LMO are 9 and 1 mol%, respectively, and the UC emission mechanism involved is a two-photon harvest process. Using the fluorescence intensity ratio (FIR) technique to analyze the temperature responses of the UC emissions arising from thermally coupled levels (TCLs) and non-thermally coupled levels (non-TCLs), the temperature sensing abilities of the synthesized samples were investigated. When the TCLs of Er3+ (2H11/2, 4S3/2) are used, the synthesized microparticles present the highest absolute and relative sensitivities of 0.0085 and 1.0236% K-1, respectively. Moreover, when the non-TCLs of Er3+ (2H11/2) and Ho3+ (5F5) are used, the maximum absolute and relative sensitivities of the synthesized compounds are 0.0296 and 0.6287% K-1, respectively. Clearly, the thermometric characteristics of the final products can be regulated via using different sensing strategies (i.e., TCLs and non-TCLs) and emission combinations (i.e., spatial mode). However, the change of the Ho3+ content has little impact on the temperature sensing capacity of the synthesized products. These results indicate that Er3+/Yb3+/Ho3+-tridoped LMO microparticles are promising candidates for optical thermometers and our findings also provide possible strategies for regulating the thermometric properties of rare-earth ion doped luminescent materials.

Efficacy of adjuvant TACE on the prognosis of patients with HCC after hepatectomy: a multicenter propensity score matching from China.

BACKGROUND: The survival benefit of adjuvant transarterial chemoembolization (TACE) in patients with hepatectomy for hepatocellular carcinoma (HCC) after hepatectomy remains controversial. We aimed to investigate the survival efficacy of adjuvant TACE after hepatectomy for HCC. METHODS: 1491 patients with HCC who underwent hepatectomy between January 2018 and September 2021 at four medical centers in China were retrospectively analyzed, including 782 patients who received adjuvant TACE and 709 patients who did not receive adjuvant TACE. Propensity score matching (PSM) (1:1) was performed to minimize selection bias, which balanced the clinical characteristics of the two groups. RESULTS: A total of 1254 patients were enrolled after PSM, including 627 patients who received adjuvant TACE and 627 patients who did not receive adjuvant TACE. Patients who received adjuvant TACE had higher disease-free survival (DFS, 1- ,2-, and 3-year: 78%-68%-62% vs. 69%-57%-50%, p < 0.001) and overall survival (OS, 1- ,2-, and 3-year: 96%-88%-80% vs. 90%-77%-66%, p < 0.001) than those who did not receive adjuvant TACE (Median DFS was 39 months). Among the different levels of risk factors affecting prognosis [AFP, Lymphocyte-to-monocyte ratio, Maximum tumor diameter, Number of tumors, Child-Pugh classification, Liver cirrhosis, Vascular invasion (imaging), Microvascular invasion, Satellite nodules, Differentiation, Chinese liver cancer stage II-IIIa], the majority of patients who received adjuvant TACE had higher DFS or OS than those who did not receive adjuvant TACE. More patients who received adjuvant TACE accepted subsequent antitumor therapy such as liver transplantation, re-hepatectomy and local ablation after tumor recurrence, while more patients who did not receive adjuvant TACE accepted subsequent antitumor therapy with TACE after tumor recurrence (All p < 0.05). CONCLUSIONS: Adjuvant TACE may be a potential way to monitor early tumor recurrence and improve postoperative survival in patients with HCC.

Postoperative adjuvant transarterial chemoembolisation improves survival of hepatocellular carcinoma patients with microvascular invasion: A multicenter retrospective cohort.

BACKGROUND: We aimed to investigate the efficacy of postoperative adjuvant transarterial chemoembolisation (PA-TACE) in patients with hepatocellular carcinoma (HCC) complicated by microvascular invasion (MVI). METHODS: A retrospective analysis of 1505 patients with HCC who underwent hepatectomy at four medical centers, including 782 patients who received PA-TACE and 723 patients who did not receive adjuvant PA-TACE, has been conducted. Propensity score matching (PSM) (1:1) was performed on the data to minimise selection bias, which resulted in a balanced clinical profile between groups. RESULTS: After PSM, 620 patients who received PA-TACE and 620 patients who did not receive PA-TACE were included. Disease-free survival (DFS, 1-, 2-, and 3-year: 88%-68%-61% vs. 70%-58%-51%, p < 0.001) and overall survival (OS, 1-, 2-, and 3-year: 96%-89%-82% vs. 89%-77%-67%, p < 0.001) were significantly higher in patients who received PA-TACE than in those who did not. Patients with MVI who received PA-TACE had significantly higher DFS (1-, 2-, and 3-year: 68%-57%-48% vs. 46%-31%-27%, p < 0.001) and OS (1-, 2-, and 3-year: 96%-84%-77% vs. 79%-58%-40%, p < 0.001) than those who did not receive PA-TACE. Among the six different liver cancer stages, MVI-negative patients did not have significant survival outcomes from PA-TACE (p > 0.05), whereas MVI-positive patients achieved higher DFS and OS from it (p < 0.05). Liver dysfunction, fever, and nausea/vomiting were the most common adverse events in patients receiving PA-TACE. There was no significant difference in grade 3 or 4 adverse events between the groups (p > 0.05). CONCLUSIONS: Postoperative adjuvant transarterial chemoembolisation has a good safety profile and may be a potentially beneficial treatment modality for survival outcomes in patients with HCC, especially those with concomitant MVI.

Highly-efficient Eu2+-activated Sr8Si4O12Cl8 cyan-emitting phosphors with zero-thermal quenching luminescence for versatile applications.

To settle the problem of phosphors with unsatisfactory luminescence efficiency and serious thermal quenching, Eu2+-activated Sr8Si4O12Cl8 cyan-emitting phosphors were designed. Excited at 387 nm, a dazzling cyan emission located at 492 nm is observed in the resultant phosphors and its maximum intensity is obtained when the Eu2+ content is 4 mol%. Moreover, the zero-thermal quenching luminescence, even when the temperature is 503 K, the integrated emission intensity still maintains 106% of its starting value at 303 K, is realized in resultant phosphors because of the efficient energy transfer from defect levels to Eu2+, which is confirmed by the thermoluminescence spectrum. The electroluminescence spectrum of the packaged white light-emitting diode (white-LED) is detected and it is found to possess a high color rendering index (91.0), low correlated color temperature (4875 K) and a superior luminous efficiency (68.7 lm W-1), implying that the developed phosphors can be adopted as cyan-emitting components to fulfill the cyan gap and realize a full spectrum white-LED. Furthermore, the cathodoluminescence (CL) performance of samples is also studied, in which its CL emission intensity is greatly impacted by the accelerating voltage and the filament current. Additionally, using the synthesized phosphors, various types of patterns are designed for use in information encryption. These achievements reveal that the Eu2+-activated Sr8Si4O12Cl8 phosphors are multifunctional cyan-emitting candidates for full spectrum white-LED, field-emission display and anti-counterfeiting applications.

Rare benign liver tumors that require differentiation from hepatocellular carcinoma: focus on diagnosis and treatment.

BACKGROUND/AIM: Recently, an increase in the number of asymptomatic rare benign liver tumors (BLTs) has been reported during health check-ups. It is difficult to determine the nature of partial rare BLTs and not easy to distinguish from malignant liver tumors. This study aimed to analysis clinical features, diagnosis and treatment of rare BLTs to reduce misdiagnosis and provide reference for clinical practice. METHODS: From January 2012 to January 2021, we treated 112 rare BLTs by hepatectomy, including 54 focal nodular hyperplasias, 14 hepatocellular adenomas, 28 hepatic angiomyolipomas, 3 hepatic granulomas, 2 inflammatory pseudotumors of the liver, 2 nodular regenerative hyperplasia, 2 hepatic lipomas, 1 solitary fibrous tumor of the liver, 1 hepatic schwannoma and 1 hepatic myelolipoma. RESULTS: The majority of patients were middle-aged female and asymptomatic. Single tumors were dominant. The diagnostic accuracies of computed tomography (CT) and magnetic resonance imaging (MRI) were 32.5% and 44.2%, respectively. The majority of tumors were likely to be misdiagnosed as hepatocellular carcinoma (HCC) or difficult to distinguish from HCC. All patients underwent surgical treatment. Postoperative pathological and immunohistochemical examination can confirm the diagnosis. No patients without tumor recurrence or metastasis during follow-up period. CONCLUSION: Altogether, the clinical symptoms of rare BLTs lack specificity, and their preoperative diagnosis largely depends on imaging examination, with a low diagnostic accuracy rate and high chances of misdiagnosis as HCC. Diagnosis is confirmed by pathological and immunohistochemical examination. Surgical resection for rare BLT is safe and effective, regular postoperative follow-up is necessary.

Hepatectomy After Conversion Therapy for Initially Unresectable HCC: What is the Difference?

Purpose: Conversion therapy gives some patients with initially unresectable hepatocellular carcinoma (HCC) access to surgery. The purpose of this study was to evaluate the safety and efficacy of hepatectomy after conversion therapy and how it differed from those who undergoing direct hepatectomy. Patients and Methods: From January 2018 to April 2022, 745 patients underwent hepatectomy for HCC were enrolled. Among them, 41 patients of unresectable HCC underwent hepatectomy after conversion therapy. A demographically and clinically comparable cohort was created from the remaining patients in a 1:1 ratio using propensity score matching. Results: The median duration of conversion therapy was 108 (42-298) days, 8 patients achieved complete response (CR) and 33 achieved partial response (PR). Conversion therapy resulted in some degree of myelosuppression, but liver function index remained good. Compared with the direct hepatectomy group, the conversion group had more blood loss (600 mL vs 400 mL, p=0.015), longer operative time (270 min vs 240 min, p=0.02), higher blood transfusion rates, and longer hospital stay (8 days vs 11 days, p<0.001). Patients in the conversion group had significantly more complications of any grade (82.9% vs 51.2%, p=0.002) and grade 3/4 (26.8% vs 4.9%, p=0.013), and 6 patients developed post-hepatectomy liver failure (PHLF). There were no deaths in either group. All patients achieved R0 resection, 6 (6/41, 14.6%) achieved pathological complete response (pCR), 14 achieved major pathologic responses (MPR). During a median follow-up of 12.8 months, 14 patients in the conversion group experienced recurrence or metastasis, no deaths. Conclusion: Hepatectomy after conversion therapy was more difficult than direct hepatectomy, but accurate preoperative assessment could ensure the safety of the surgery. The damage of liver function after conversion therapy was more severe than expected, PHLF should be prevented and treated. Hepatectomy was effective and necessary, postoperative pathological examination could provide guidance for adjuvant therapy.

Hepatic arterial infusion chemotherapy combined with PD-1 inhibitors and tyrosine kinase inhibitors for unresectable hepatocellular carcinoma: A tertiary medical center experience.

Background: Unresectable hepatocellular carcinoma (u-HCC) still accounts for the majority of newly diagnosed HCC which with poor prognosis. In the era of systemic therapy, combination therapy with programmed cell death protein-1 (PD-1) inhibitors and tyrosine kinase inhibitors (TKIs) has become mainstream. Hepatic arterial infusion chemotherapy (HAIC) as a local treatment has also shown a strong anti-tumor effect. This study aimed to investigate the efficacy and safety of HAIC, PD-1 inhibitors plus TKIs for u-HCC. Methods: This retrospective study included patients with initially u-HCC between October 2020 to April 2022 who had received at least one cycle of therapy with HAIC, PD-1 inhibitors plus TKIs. The primary outcome included overall response rate (ORR), the disease control rate (DCR), surgical conversion rate, progression-free survival (PFS) and treatment-related adverse events. Results: A total of 145 patients were included in the study. The median treatment cycle of HAIC and PD-1 inhibitors were 3 and 4, respectively. According to the modified RECIST criteria, the best ORR was 57.2% (83/145), 9 had achieved complete response (CR), DCR was 89.7% (130/145). Median time to achieve CR or PR was 65 days. Surgical conversion rate was 18.6% (27/145), seven patients (7/27,25.9%) achieved pathological complete response (pCR). The median follow-up was 12.5 months (4.5-20 months), and the median PFS was 9.7 months. Subgroup analysis showed that Child-pugh A patients had higher DCR (92.2% vs 79.3%, p=0.041) than Child-pugh B patients, as well as increased successful conversion rate (22.4% vs 3.4%, p=0.019). Patients without vascular invasion and extrahepatic metastases showed higher PR (63.4% vs 43.3%, p<0.05) and ORR (73.2% vs 50.0%, p<0.05) than those with vascular invasion. The ORR (73.2% vs 45.5%, p<0.05) and DCR (95.1% vs 78.8%, p<0.05) were also significantly better than those of patients with extrahepatic metastases. HAIC regimen was not related to efficacy (All p>0.05). The incidence rate of grade 3/4 treatment-related AEs was 17.7% without fatal events. Conclusion: The triple combination therapy of HAIC and PD-1 inhibitors plus TKIs for patients with initially unresectable HCC exhibited satisfactory efficacy with tolerable toxicity.

Visible-near-Infrared Light-Driven Photocatalytic Characteristics of Er3+/Yb3+-Codoped BiOBr Upconverting Microparticles for Tetracycline Degradation.

To settle the unsatisfying efficiency and insufficient light harvesting ability of photocatalysts, we report on the development of Er3+/Yb3+-codoped BiOBr (BiOBr:Er3+/xYb3+) microparticles that were synthesized by a rational high-temperature solid-state reaction method. The prepared microcrystals exhibit high visible upconversion (UC) emissions with maximum intensities at x = 0.01 when excited by a 980 nm laser. Remarkably, the corresponding UC emission process is attributed to a two-photon absorption route. Furthermore, the photocatalytic activities of as-synthesized compounds were further evaluated through analyzing the visible-near-infrared light-triggered tetracycline degradation. Compared with BiOBr:Er3+ microparticles, BiOBr:Er3+/xYb3+ microparticles present superior photocatalytic properties and the optimal status is achieved when x = 0.05, in which h+, ·O2-, and ·OH active species contribute to the photocatalytic mechanism. Additionally, the designed microparticles exhibit better photocatalytic abilities than previously reported photocatalysts (i.e., TiO2, SnO2) upon full-spectrum light irradiation. These results reveal that Yb3+ codoping is able to not only enhance the UC emission properties of BiOBr:Er3+ microparticles but also reinforce their photocatalytic activities. Our findings may put forward a facile strategy to regulate the photodegradation capacity of photcatalysts.

Manipulating Upconversion Emission and Thermochromic Properties of Ho3+/Yb3+-Codoped Al2Mo3O12 Microparticles by Negative Lattice Expansion for Multimode Visual Optical Thermometry.

To ameliorate the inherent thermal quenching behaviors of upconverting materials, a series of Ho3+/Yb3+-codoped Al2Mo3O12 (i.e., Al2Mo3O12:Ho3+/2xYb3+) microparticles were developed. Upon excitation at 980 nm, intense upconversion (i.e., UC) emissions arising from Ho3+ are observed, and their optimal states occur at x = 0.09. Besides, the UC mechanisms of these generated emissions from 5F4/5S2 and 5F5 levels all pertain to a two-photon absorption process. Furthermore, modified thermal quenching performances are realized in the resultant microparticles, in which the intensities of the UC emissions arising from 5F4/5S2 levels decrease as the temperature increases, while that of the UC emission from the 5F5 level increases and then decreases with the increase of temperature. The coexistence of nonradiative transition promoted crossrelaxation, and energy transfer routes can be responsible for the above phenomenon. By studying the diverse UC emission characteristics at high temperatures, we revealed the thermometric properties of Al2Mo3O12:Ho3+/2xYb3+ microparticles, where their sensitivities can be regulated by selecting the spectral mode and dopant contents. According to the intensity ratio of the UC emissions originating from 5F5 → 5I8 to (5F4,5S2) → 5I7 transitions at different temperatures, one obtains that the relative and absolute sensitivities of the developed compounds reach up to 0.464% and 0.1739 K-1, respectively. Additionally, by the analysis of the thermochromic performances of final products, their thermometric characteristics were also investigated. Note that the environmental temperature is able to be facilely read out by distinguishing the emitting color. These results verify that the Al2Mo3O12:Ho3+/2xYb3+ microparticles are promising luminescent materials for multimode visual optical thermometry.

Enhanced Visible Light-Driven Photocatalytic Activities and Photoluminescence Characteristics of BiOF Nanoparticles Determined via Doping Engineering.

We report a new type of highly efficient visible light-driven photocatalyst, Sm3+-activated BiOF nanoparticles, developed by a facile solid-state reaction technology. The corresponding phase compositions, morphological nature, and chemical states along with complementary theoretical calculation insights are investigated systematically. Upon 404 nm laser excitation, the photoluminescence performance of the synthesized nanoparticles is explored and the optimal properties are achieved in BiOF:xSm3+ (x = 0.07). The dipole-quadrupole interaction is attributed to the concentration quenching mechanism. Under visible light irradiation, the degradation of the RhB dye by utilizing the Sm3+-activated BiOF nanoparticles is studied. In comparison with the BiOF nanoparticles, the resultant compounds doped with Sm3+ ions demonstrate improved photocatalytic performance. Moreover, on the basis of density functional theory, the electronic structure of the BiOF impacted by Sm3+ ion doping is studied in detail by first-principles calculations, revealing the generation of an impurity energy level that is beneficial for enhancing the photocatalytic properties. Importantly, the h+ and •O2- active species play a deterministic role in promoting the degradation of the RhB dye. Compared to commercial ZnO nanoparticles, the developed nanoparticles exhibit superior photocatalytic activities, further elaborating that the Sm3+-activated BiOF nanoparticles are poised to be one of most promising visible light-driven photocatalyst candidates.

Ultra-high sensitivity of multicolor Sm3+-doped LiSrVO4 phosphors for contactless optical thermometers.

To overcome the existing challenge of temperature monitoring with high accuracy, we designed Sm3+-doped LiSrVO4 phosphors with ultra-high sensitivity as promising candidates for optical thermometers. The prepared samples could emit multicolor emissions after excitation at 343 nm and the optimum doping concentration for the Sm3+ ions in the selected host was 1 mol%. The mechanism of energy transfer from the VO43- group to the Sm3+ ions was studied and its efficiency was proved to be 84.1% for an Sm3+ ion content of 7 mol%. Based on the disparate thermal quenching performances of the VO43- group and Sm3+ ions, the temperature monitoring ability of the prepared compounds was examined. Through choosing different emissions of Sm3+ ions, and then combining them with the VO43- group, optical thermometers with controllable sensitivity were realized. The maximum absolute and relative sensitivities of the resultant phosphors could reach ultra-high values of 1.076 K-1 and 6.167% K-1, respectively, which were the highest sensitivities reported so far. Furthermore, the doping content also impacted the sensitivities of the resultant compounds.

Ratiometric optical thermometer based on the use of manganese(II)-doped Cs3Cu2I5 thermochromic and fluorescent halides.

The inconsistent thermal quenching performance of manganese(II)-doped Cs3Cu2I5 microparticles is exploited in a highly sensitive noninvasive optical thermometer. The ratio of the emissions of Cu(II) and Mn(II) ions in the microparticles is highly temperature dependent in the range from 298 to 498 K. The best absolute and relative sensitivities are 0.547 K-1 and 0.525% K-1, respectively. The emission spectrum, under 300-nm photoexcitation, has emission peaks at 448 and 556 nm. This is the result of energy transfer between the Cu(II) and Mn(II) ions whose efficiency can reach up to 57% when the Mn(II) ion concentration is 2 mol%. The emission color of the microparticles changes from cyan to green when increasing the temperature from 298 to 498 K. Graphical abstract Synthesis of novel Mn(II)-doped Cs3Cu2I5 thermochromic halides with admirable luminescent behaviors for high sensitive ratiometric thermometry and safety sign in high temperature environment.

Giant tunability of upconversion photoluminescence in Er3+-doped (K, Na)NbO3 single crystals.

Perovskite oxides with luminescent ions hold great promise in optoelectronic devices because of their outstanding thermal stabilities and electro-optic performance. As one typical perovskite upconversion (UC) host material, lead-free potassium sodium niobate ((K, Na)NbO3/(KxNa1-x)NbO3 or KNN) has attracted much attention in recent years. In the present work, a novel routine was developed to tune the upconversion photoluminescence (UC PL) performance by controlling the oxygen vacancy concentration in the KNN matrix, based on the 0.1% Er3+-doped KNN (Er-KNN) single crystals grown for the first time. UC PL properties, conductivity and defect chemistry of the single crystals were systematically investigated. The UC PL intensity of the as-grown Er-KNN material could be enhanced by 20 times after oxygen atmosphere annealing at 800 °C and fully quenched after vacuum annealing. What's more, by annealing under an oxygen atmosphere and vacuum, the conductivity of the Er-KNN sample was successfully tuned for more than 8 orders of magnitude. The super-wide range tunability of UC PL performance and conductivity could be explained by oxygen vacancies which gave rise to Nb5+-Nb4+ valence alternation. Because of the modulated photoluminescence properties and conductivity, our grown Er-KNN single crystals have great potential for use in multifunctional devices.