Single-Cell Quantification of Cytosine Modifications by Hyperspectral Dark-Field Imaging

Epigenetic modifications on DNA, especially on cytosine, play a critical role in regulating gene expression and genome stability. It is known that the levels of different cytosine derivatives are highly dynamic and are regulated by a variety of factors that act on the chromatin. Here we report an optical methodology based on hyperspectral dark-field imaging (HSDFI) using plasmonic nanoprobes to quantify the recently identified cytosine modifications on DNA in single cells. Gold (Au) and silver (Ag) nanoparticles (NPs) functionalized with specific antibodies were used as contrast-generating agents due to their strong local surface plasmon resonance (LSPR) properties. With this powerful platform we have revealed the spatial distribution and quantity of 5-carboxylcytosine (5caC) at the different stages in cell cycle and demonstrated that 5caC was a stably inherited epigenetic mark. We have also shown that the regional density of 5caC on a single chromosome can be mapped due to the spectral sensitivity of the nanoprobes in relation to the interparticle distance. Notably, HSDFI enables an efficient removal of the scattering noises from nonspecifically aggregated nanoprobes, to improve accuracy in the quantification of different cytosine modifications in single cells. Further, by separating the LSPR fingerprints of AuNPs and AgNPs, multiplex detection of two cytosine modifications was also performed. Our results demonstrate HSDFI as a versatile platform for spatial and spectroscopic characterization of plasmonic nanoprobe-labeled nuclear targets at the single-cell level for quantitative epigenetic screening

Value of the revised Atlanta classification (RAC) and determinant-based classification (DBC) systems in the evaluation of acute pancreatitis

<p><b>Objective:</b> Since increasing acute pancreatitis (AP) severity is significantly associated with mortality, accurate and rapid determination of severity is crucial for effective clinical management. This study investigated the value of the revised Atlanta classification (RAC) and the determinant-based classification (DBC) systems in stratifying severity of acute pancreatitis.</p> <p><b>Methods:</b> This retrospective observational cohort study included 480 AP patients. Patient demographics and clinical characteristics were recorded. The primary outcome was mortality, and secondary outcomes were admission to intensive care unit (ICU), duration of ICU stay, and duration of hospital stay.</p> <p><b>Results:</b> Based on the RAC classification, there were 295 patients with mild AP (MAP), 146 patients with moderate-to-severe AP (MSAP), and 39 patients with severe AP (SAP). Based on the DBC classification, there were 389 patients with MAP, 41 patients with MSAP, 32 patients with SAP, and 18 patients with critical AP (CAP). ROC curve analysis showed that the DBC system had a significantly higher accuracy at predicting organ failure compared to the RAC system (<i>p</i> < .001). Multivariate regression analysis showed that age and ICU stay were independent risk factors of mortality.</p> <p><b>Conclusion:</b> The DBC system had a higher accuracy at predicting organ failure. Age and ICU stay were significantly associated with risk of death in AP patients. A classification of CAP by the DBC system should warrant close attention, and rapid implementation of effective measures to reduce mortality.</p

Synthesis of the Cyclopentane Core Skeleton of Cranomycin and Jogyamycin

Cranomycin and jogyamycin, two aminocyclopentitol natural products, possess complex structures and potential medicinal properties. This review describes synthetic studies about the process of making an advanced intermediate of cranomycin and jogyamycin. This highly functionalized intermediate, featuring three contiguous amine-substituted stereocenters, was constructed from cyclopentadiene through a series of reactions including the nitroso Diels–Alder reaction, nitrogen radical cyclization reaction, 1,2-nitrogen migration, and stereoselective nitrogen addition

Oxygen Nanobubble Tracking by Light Scattering in Single Cells and Tissues

Oxygen nanobubbles (ONBs) have significant potential in targeted imaging and treatment in cancer diagnosis and therapy. Precise localization and tracking of single ONBs is demonstrated based on hyperspectral dark-field microscope (HSDFM) to image and track single oxygen nanobubbles in single cells. ONBs were proposed as promising contrast-generating imaging agents due to their strong light scattering generated from nonuniformity of refractive index at the interface. With this powerful platform, we have revealed the trajectories and quantities of ONBs in cells, and demonstrated the relation between the size and diffusion coefficient. We have also evaluated the presence of ONBs in the nucleus with respect to an increase in incubation time and have quantified the uptake in single cells in <i>ex vivo</i> tumor tissues. Our results demonstrate that HSDFM can be a versatile platform to detect and measure cellulosic nanoparticles at the single-cell level and to assess the dynamics and trajectories of this delivery system

Mesoscale Mass Transport Enhancement on Well-Defined Porous Carbon Platform for Electrochemical H₂O₂ Synthesis

Two-electron oxygen reduction toward hydrogen peroxide (H2O2) offers a promising alternative for H2O2 production, but its commercial utilization is still hindered by the difficulty of transferring lab-observed catalyst performance to the practical reactor. Here we report the investigation of the porosity engineering effect on catalytic performance inconsistency through a material platform consisting of a series of hollow mesoporous carbon sphere (HMCS) samples. The performance comparison of HMCS samples in rotating ring-disk electrode and Zn-air battery together with the simulation of diffusion behavior reveals that, in low current density conditions, large surface area is preferred, but the mass transport governs the performance in high current density regions. On account of the favorable porous structure, HMCS-8 nm delivers the most excellent practical performance (166 mW cm–2) and performs well in the bifunctional Zn-air battery for the wastewater purification (70% RhB degraded after 2 min and 99% after 32 min)

Additional file 5: of Comparative genomic analysis reveals the evolution and environmental adaptation strategies of vibrios

Figure S3. Pan genome tree. The tree was created based on the presence or absence of gene clusters in the 20 complete Vibrio genomes. The number at each node denotes the bootstrap value based on 1000 replicates. The color red and yellow are corresponding to the core genome tree, suggesting the discrepancy between core and pan genome trees. (PDF 194 kb

Ringlike Migration of a Droplet Propelled by an Omnidirectional Thermal Gradient

The interfacial phenomenon associated with the ringlike motion of a liquid droplet subjected to an omnidirectional thermal gradient is investigated. An experimentally verified model is proposed for estimating the droplet migration velocity. It is shown that the unbalanced interfacial tension acting on the liquid in the radial direction provides the necessary propulsion for the migration, whereas the internal force acting on the adjoining liquid contributes to the equilibrium condition in the circumferential direction. This study puts forward the understanding of the interfacial spreading phenomenon, the knowledge of which is important in applications where liquid lubricants are encountered with directionally unstable thermal gradients

Additional file 8: of Comparative genomic analysis reveals the evolution and environmental adaptation strategies of vibrios

Figure S6. Genes related to the chitin-degrading process in 20 vibrios with complete genomes. Each column indicates a chitin metabolism-related gene family, with the family name indicating the predicted function. The number in the box indicates the copy number of that gene family in the corresponding genome. (PDF 282 kb

Additional file 7: of Comparative genomic analysis reveals the evolution and environmental adaptation strategies of vibrios

Figure S5. Heatmap presentation of pairwise average nucleotide identity of the 19 Vibrio species with complete genomes. The genomes are hierarchical clustered according to the values of rows. The clusters present in blue and orange are corresponding to the core genome tree. (PDF 212 kb

Additional file 6: of Comparative genomic analysis reveals the evolution and environmental adaptation strategies of vibrios

Figure S4. Neighbor-joining phylogenetic tree of the 20 vibrios genomes based on 16S rRNA gene. The number at each node denotes the bootstrap value based on 1000 replicates. S. denitrificans OS217 was used as the outgroup. Bar, 0.01 substitutions per site. (PDF 186 kb