Photon upconversion through triplet exciton-mediated energy relay.

Exploration of upconversion luminescence from lanthanide emitters through energy migration has profound implications for fundamental research and technology development. However, energy migration-mediated upconversion requires stringent experimental conditions, such as high power excitation and special migratory ions in the host lattice, imposing selection constraints on lanthanide emitters. Here we demonstrate photon upconversion of diverse lanthanide emitters by harnessing triplet exciton-mediated energy relay. Compared with gadolinium-based systems, this energy relay is less dependent on excitation power and enhances the emission intensity of Tb3+ by 158-fold. Mechanistic investigations reveal that emission enhancement is attributable to strong coupling between lanthanides and surface molecules, which enables fast triplet generation (<100 ps) and subsequent near-unity triplet transfer efficiency from surface ligands to lanthanides. Moreover, the energy relay approach supports long-distance energy transfer and allows upconversion modulation in microstructures. These findings enhance fundamental understanding of energy transfer at molecule-nanoparticle interfaces and open exciting avenues for developing hybrid, high-performance optical materials

Photon upconversion through triplet exciton-mediated energy relay

Funder: Innovation programme under the Marie Skłodowska-Curie grant agreement No 797619Funder: China Scholarship Council (CSC); doi: https://doi.org/10.13039/501100004543Funder: RCUK | Engineering and Physical Sciences Research Council (EPSRC); doi: https://doi.org/10.13039/501100000266Abstract: Exploration of upconversion luminescence from lanthanide emitters through energy migration has profound implications for fundamental research and technology development. However, energy migration-mediated upconversion requires stringent experimental conditions, such as high power excitation and special migratory ions in the host lattice, imposing selection constraints on lanthanide emitters. Here we demonstrate photon upconversion of diverse lanthanide emitters by harnessing triplet exciton-mediated energy relay. Compared with gadolinium-based systems, this energy relay is less dependent on excitation power and enhances the emission intensity of Tb3+ by 158-fold. Mechanistic investigations reveal that emission enhancement is attributable to strong coupling between lanthanides and surface molecules, which enables fast triplet generation (<100 ps) and subsequent near-unity triplet transfer efficiency from surface ligands to lanthanides. Moreover, the energy relay approach supports long-distance energy transfer and allows upconversion modulation in microstructures. These findings enhance fundamental understanding of energy transfer at molecule-nanoparticle interfaces and open exciting avenues for developing hybrid, high-performance optical materials

Deep-Sequencing Analysis of the Mouse Transcriptome Response to Infection with Brucella melitensis Strains of Differing Virulence

Brucella melitensis is an important zoonotic pathogen that causes brucellosis, a disease that affects sheep, cattle and occasionally humans. B. melitensis strain M5-90, a live attenuated vaccine cultured from B. melitensis strain M28, has been used as an effective tool in the control of brucellosis in goats and sheep in China. However, the molecular changes leading to attenuated virulence and pathogenicity in B. melitensis remain poorly understood. In this study we employed the Illumina Genome Analyzer platform to perform genome-wide digital gene expression (DGE) analysis of mouse peritoneal macrophage responses to B. melitensis infection. Many parallel changes in gene expression profiles were observed in M28- and M5-90-infected macrophages, suggesting that they employ similar survival strategies, notably the induction of anti-inflammatory and antiapoptotic factors. Moreover, 1019 differentially expressed macrophage transcripts were identified 4 h after infection with the different B. melitensis strains, and these differential transcripts notably identified genes involved in the lysosome and mitogen-activated protein kinase (MAPK) pathways. Further analysis employed gene ontology (GO) analysis: high-enrichment GOs identified endocytosis, inflammatory, apoptosis, and transport pathways. Path-Net and Signal-Net analysis highlighted the MAPK pathway as the key regulatory pathway. Moreover, the key differentially expressed genes of the significant pathways were apoptosis-related. These findings demonstrate previously unrecognized changes in gene transcription that are associated with B. melitensis infection of macrophages, and the central signaling pathways identified here merit further investigation. Our data provide new insights into the molecular attenuation mechanism of strain M5-90 and will facilitate the generation of new attenuated vaccine strains with enhanced efficacy

A multicentre single arm phase 2 trial of neoadjuvant pyrotinib and letrozole plus dalpiciclib for triple-positive breast cancer.

peer reviewedCurrent therapies for HER2-positive breast cancer have limited efficacy in patients with triple-positive breast cancer (TPBC). We conduct a multi-center single-arm phase 2 trial to test the efficacy and safety of an oral neoadjuvant therapy with pyrotinib, letrozole and dalpiciclib (a CDK4/6 inhibitor) in patients with treatment-naïve, stage II-III TPBC with a Karnofsky score of ≥70 (NCT04486911). The primary endpoint is the proportion of patients with pathological complete response (pCR) in the breast and axilla. The secondary endpoints include residual cancer burden (RCB)-0 or RCB-I, objective response rate (ORR), breast pCR (bpCR), safety and changes in molecular targets (Ki67) from baseline to surgery. Following 5 cycles of 4-week treatment, the results meet the primary endpoint with a pCR rate of 30.4% (24 of 79; 95% confidence interval (CI), 21.3-41.3). RCB-0/I is 55.7% (95% CI, 44.7-66.1). ORR is 87.4%, (95% CI, 78.1-93.2) and bpCR is 35.4% (95% CI, 25.8-46.5). The mean Ki67 expression reduces from 40.4% at baseline to 17.9% (P < 0.001) at time of surgery. The most frequent grade 3 or 4 adverse events are neutropenia, leukopenia, and diarrhoea. There is no serious adverse event- or treatment-related death. This fully oral, chemotherapy-free, triplet combined therapy has the potential to be an alternative neoadjuvant regimen for patients with TPBC

DEVELOPMENT OF GADOLINIUM-BASED NANOPARTICLES FOR EMERGING APPLICATIONS

Ph.DDOCTOR OF PHILOSOPHY (FOS

Synthesis, Tunable Multicolor Output, and High Pure Red Upconversion Emission of Lanthanide-Doped Lu2O3 Nanosheets

Yb3+ and Ln3+ (Ln = Er, Ho) codoped Lu2O3 square nanocubic sheets were successfully synthesized via a facile hydrothermal method followed by a subsequent dehydration process. The crystal phase, morphology, and composition of hydroxide precursors and target oxides were characterized by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and energy-dispersive X-ray spectroscope (EDS). Results present the as-prepared Lu2O3 crystallized in cubic phase, and the monodispersed square nanosheets were maintained both in hydroxide and oxides. Moreover, under 980 nm laser diode (LD) excitation, multicolor output from red to yellow was realized by codoped different lanthanide ions in Lu2O3. It is noteworthy that high pure strong red upconversion emission with red to green ratio of 443.3 of Er-containing nanocrystals was obtained, which is beneficial for in vivo optical bioimaging

Spatial Distribution and Contamination Assessment of Heavy Metals in Surface Sediments of the Caofeidian Adjacent Sea after the Land Reclamation, Bohai Bay

Land reclamation can significantly influence spatial distribution of heavy metals in inshore sediments. In this study, the distribution and contamination of heavy metals (Cd, Cr, Cu, Ni, Pb, and Zn) in inshore sediments of Bohai Bay were investigated after the land reclamation of Caofeidian. The results showed that the concentrations of Cd, Cr, Cu, Ni, Pb, and Zn in the sediments were 0.20–0.65, 27.16–115.70, 11.14–39.00, 17.37–65.90, 15.08–24.06, and 41.64–139.56 mg/kg, respectively. These metal concentrations were generally higher in the area of Caofeidian than in other Chinese bays and estuaries. Spatially, the concentrations of Cd, Cr, Cu, Ni, and Zn were markedly lower in the sediments close to Caofeidian compared with other regions, whereas the concentrations of Pb showed an opposite case. Hydrodynamic conditions after the land reclamation were the major factor influencing the distribution of heavy metals in the sediments. Grain sizes dominated the distribution of Cu and Zn, and organic matters and Fe/Mn oxides/hydroxides also determined the distribution of the heavy metals. Multiple contamination indices showed that the inshore sediments were moderately to highly contaminated by Cd and slightly contaminated by other heavy metals. Similarly, Cd showed a high potential ecorisk in the sediments, and other metals were in the low level. Chromium contributed to higher exposure toxicity than other metals by the toxicity unit and toxic risk index. The results of this study indicate that after the land reclamation of Caofeidian the contamination and ecorisk of heavy metals in the sediments markedly decreased in the stronger hydrodynamic areas