Traditional in vitro anticancer drug sensitivity testing at the population level suffers from lengthy procedures and high false positive rates. To overcome these defects, we built a confocal Raman microscopy sensing system and proposed a single-cell approach via Raman-deuterium isotope probing (Raman-DIP) as a rapid and reliable in vitro drug efficacy evaluation method. Raman-DIP detected the incorporation of deuterium into the cell, which correlated with the metabolic activity of the cell. The human non-small cell lung cancer cell line HCC827 and human breast cancer cell line MCF-7 were tested against eight different anticancer drugs. The metabolic activity of cancer cells could be detected as early as 12 h, independent of cell growth. Incubation of cells in 30% heavy water (D₂O) did not show any negative effect on cell viability. Compared with traditional methods, Raman-DIP could accurately determine the drug effect, meanwhile, it could reduce the testing period from 72–144 h to 48 h. Moreover, the heterogeneity of cells responding to anticancer drugs was observed at the single-cell level. This proof-of-concept study demonstrated the potential of Raman-DIP to be a reliable tool for cancer drug discovery and drug susceptibility testing.

This study proposes a constitutive model of the pile-soil interface based on a thermodynamic approach. Firstly, the thermo-elastic coupled nonlinear hyperelastic relation of the pile-soil interface is derived by defining the interface potential energy function of the pile-soil interface subjected to normal and tangential forces. The plastic interface constitutive relations are then developed using non-equilibrium thermodynamics, based on the energy dissipations caused by the pile-soil interface's shear-induced slipping behavior. The stress- and temperature-dependent pile-soil interface behavior is described using the concept of interface density and the normal elastic thermal expansion coefficient.

The sperm chromatin dispersion (SCD) test is widely used to assess sperm DNA fragmentation by observing the halo structure around the sperm head. However, manual halo interpretation is labor-intensive and subjective, which limits its consistency and throughput in clinical practice. To address these limitations, we propose SHIELD-Net, an image-level single-sperm halo morphology classification framework for four halo categories: large halo, medium halo, small halo, and without halo. SHIELD-Net includes two modules, i.e., a hybrid ROI extraction (HyREx) module and dual-view learning with ROI-guided gate fusion (RGF). The HyREx module converts the traditional direct classification pipeline into a segmentation-classification pipeline. It uses the cell segmentation foundation model, i.e., Cellpose, to segment halo-centered regions of interest (ROIs) and proposes a fallback mechanism to ensure segmentation effectiveness. In this way, HyREx can construct a head–halo-centered ROI and reduce interference from tail and background regions. Based on the original image and the extracted ROI, SHIELD-Net performs dual-view ConvNeXt encoding. RGF further uses the ROI representation to generate a spatial gate that recalibrates the original-view feature map toward halo-morphology-related responses. Experiments were conducted on a public expert-annotated sperm microscopy dataset containing 403 individual sperm halo images using stratified five-fold cross-validation. SHIELD-Net achieved a Macro F1 of 0.9290 ± 0.0161. Compared with the original-image ConvNeXt-Small baseline, SHIELD-Net improved Macro F1 by 0.1755. These results indicate that combining head–halo-centered ROI construction with ROI-guided feature recalibration improves image-level sperm halo morphology classification.

The coordination of intracellular carbon and nitrogen levels is essential for optimal bacterial growth and, in rhizobia, for survival in the soil, root colonization, and symbiotic interactions with their host plants. Here, we show that the phosphotransferase system PTS ^Ntr , a global regulator of carbon and nitrogen metabolism, modulates the tricarboxylic acid (TCA) cycle activity and the accumulation of three major carbon storage polymers: glycogen, polyhydroxybutyrate, and exopolysaccharide in Rhizobium leguminosarum . The unphosphorylated form of the effector protein ManX is sufficient for the full activation of the TCA cycle dehydrogenase enzymes. Accordingly, loss of manX reduced dehydrogenase activity and redirected overflow carbon into storage polymers, phenocopying wild-type cells grown under nitrogen starvation. We further demonstrate that carbon metabolism in R. leguminosarum is also tightly regulated by the HPr kinase (HprK) protein. In an hprK mutant, loss of NPr Ser48 phosphorylation favors phosphotransfer through the histidyl arm and is predicted to increase phosphorylation of downstream PTS ^Ntr components. When grown on glucose, the hprK mutant accumulates elevated intracellular pyrimidine levels and exhibits increased malate dehydrogenase and TCA cycle activity, consistent with a misregulated shift toward gluconeogenesis. This mutant also overproduces exopolysaccharide, an effect potentially mediated by crosstalk between phosphorylated PtsN and the ChvI/ChvG two-component regulatory system. Together, these data suggest that HprK exerts pleiotropic control over processes regulated by PTS ^Ntr , influencing central metabolism while repressing exopolysaccharide production, likely by promoting the unphosphorylated state of PtsN. IMPORTANCE: Bacteria must continuously balance growth, nutrient availability, and storage to ensure fitness and survival in fluctuating environments. However, how regulatory networks integrate central metabolism with carbon storage remains poorly understood. This study reinforces the role of the PTS ^Ntr system as a central coordinator of carbon routing and polymer accumulation. By revealing how ManX and HprK-dependent phosphorylation influence central metabolism and the production of major carbon storage polymers in Rhizobium leguminosarum , we show that disruption of PTS ^Ntr signaling reprograms carbon allocation, uncoupling growth from carbon storage and mimicking nitrogen starvation even under nitrogen-replete conditions. These findings highlight a regulatory link between carbon-nitrogen signaling and bacterial storage strategies, with implications for cellular survival and plant symbiosis. More broadly, our work illustrates how global metabolic regulators shape bacterial physiological states, providing new insights into mechanisms that support microbial adaptation in complex environments.