Unraveling pancreatic ductal adenocarcinoma immune prognostic signature through a naive B cell gene set.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC), a leading cause of cancer mortality, has a complex pathogenesis involving various immune cells, including B cells and their subpopulations. Despite emerging research on the role of these cells within the tumor microenvironment (TME), the detailed molecular interactions with tumor-infiltrating immune cells (TIICs) are not fully understood. METHODS: We applied CIBERSORT to quantify TIICs and naive B cells, which are prognostic for PDAC. Marker genes from scRNA-seq and modular genes from weighted gene co-expression network analysis (WGCNA) were integrated to identify naive B cell-related genes. A prognostic signature was constructed utilizing ten machine-learning algorithms, with validation in external cohorts. We further assessed the immune cell diversity, ESTIMATE scores, and immune checkpoint genes (ICGs) between patient groups stratified by risk to clarify the immune landscape in PDAC. RESULTS: Our analysis identified 994 naive B cell-related genes across single-cell and bulk transcriptomes, with 247 linked to overall survival. We developed a 12-gene prognostic signature using Lasso and plsRcox algorithms, which was confirmed by 10-fold cross-validation and showed robust predictive power in training and real-world cohorts. Notably, we observed substantial differences in immune infiltration between patients with high and low risk. CONCLUSION: Our study presents a robust prognostic signature that effectively maps the complex immune interactions in PDAC, emphasizing the critical function of naive B cells and suggesting new avenues for immunotherapeutic interventions. This signature has potential clinical applications in personalizing PDAC treatment, enhancing the understanding of immune dynamics, and guiding immunotherapy strategies.

Mechanism driven design of trimer Ni1Sb2 site delivering superior hydrogenation selectivity to ethylene.

Mechanism driven catalyst design with atomically uniform ensemble sites is an important yet challenging issue in heterogeneous catalysis associated with breaking the activity-selectivity trade-off. Herein, a trimer Ni1Sb2 site in NiSb intermetallic featuring superior selectivity is elaborated for acetylene semi-hydrogenation via a theoretical guidance with a precise synthesis strategy. The trimer Ni1Sb2 site in NiSb intermetallic is predicted to endow acetylene reactant with an adequately but not excessively strong σ-adsorption mode while ethylene product with a weak π-adsorption one, where such compromise delivers higher ethylene formation rate. An in-situ trapping of molten Sb by Ni strategy is developed to realize the construction of Ni1Sb2 site in the intermetallic P63/mmc NiSb catalysts. Such catalyst exhibits ethylene selectivity up to 93.2% at 100% of acetylene conversion, significantly prevailing over the referred Ni catalyst. These insights shed new lights on rational catalyst design by taming active sites to energetically match targeted reaction pathway.

Selective tracking of ovarian-cancer-specific γ-glutamyltranspeptidase using a ratiometric two-photon fluorescent probe.

Real-time tracking of GGT enzymatic activity in human ovarian cancer cells is a reliable method for accurate prediction of cancer diagnosis and management. Here, we report the two-photon ratiometric tracking of GGT activity in cancer cells based on a probe with switchable Förster resonance energy transfer properties. In the absence of GGT, the designed probe showed two well-resolved emission bands at 461 and 610 nm, corresponding to the 7-hydroxycoumarin donor and BODIPY acceptor, respectively. In contrast, GGT catalyzed cascade reactions including cleavage of the γ-glutamyl group and subsequent aromatic hydrocarbon transfer from the S to N atom increased the distance between the two chromophores, thus decreasing the FRET efficiency, with the recovery of the donor fluorescence at 461 nm. By exploiting this enzyme-triggered ratiometric measurement, successful differentiation of ovarian cancer cells from normal cells with this probe was realized by two-photon fluorescence confocal microscopy.

Selectivity switching resulting in the formation of benzene by surface carbonates on ceria in catalytic gas-phase oxidation of benzyl alcohol.

The irreversible formation of carbonate deposits on CeO2 leads to complete switching of catalytic selectivity resulting in the formation of benzene in gas-phase oxidation of benzyl alcohol. By integrating experimental spectra and theoretical calculations, we expect that such a shift is derived from further decarbonylation of benzaldehyde via easy trapping of CO fragments by surface carbonate species.

Methanol Conversion into Dimethyl Ether on the Anatase TiO2(001) Surface.

Exploring reactions of methanol on TiO2 surfaces is of great importance in both C1 chemistry and photocatalysis. Reported herein is a combined experimental and theoretical calculation study of methanol adsorption and reaction on a mineral anatase TiO2(001)-(1×4) surface. The methanol-to-dimethyl ether (DME) reaction was unambiguously identified to occur by the dehydration coupling of methoxy species at the fourfold-coordinated Ti(4+) sites (Ti(4c)), and for the first time confirms the predicted higher reactivity of this facet compared to other reported TiO2 facets. Surface chemistry of methanol on the anatase TiO2(001)-(1×4) surface is seldom affected by co-chemisorbed water. These results not only greatly deepen the fundamental understanding of elementary surface reactions of methanol on TiO2 surfaces but also show that TiO2 with a high density of Ti(4c) sites is a potentially active and selective catalyst for the important methanol-to-DME reaction.