By virtue of the combined merits of flow cytometry and fluorescence microscopy, imaging flow cytometry (IFC) has become an established tool for cell analysis in diverse biomedical fields such as cancer biology, microbiology, immunology, hematology, and stem cell biology. However, the performance and utility of IFC are severely limited by the fundamental trade-off between throughput, sensitivity, and spatial resolution. Here we present an optomechanical imaging method that overcomes the trade-off by virtually freezing the motion of flowing cells on the image sensor to effectively achieve 1000 times longer exposure time for microscopygrade fluorescence image acquisition. Consequently, it enables high-throughput IFC of single cells at >10,000 cells s −1 without sacrificing sensitivity and spatial resolution. The availability of numerous information-rich fluorescence cell images allows high-dimensional statistical analysis and accurate classification with deep learning, as evidenced by our demonstration of unique applications in hematology and microbiology.

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Maintenance of self-renewal and pluripotency in mouse embryonic stem cells (mESCs) is regulated by the balance between several extrinsic signaling pathways. Recently, we demonstrated that heparan sulfate (HS) chains play important roles in the maintenance and differentiation of mESCs by regulating extrinsic signaling. Sulfated HS structures are modified by various sulfotransferases during development. However, the significance of specific HS structures during development remains unclear. Here, we show that 3-O-sulfated HS structures synthesized by HS 3-O-sulfotransferases (3OSTs) and recognized by the antibody HS4C3 increase during differentiation of mESCs. Furthermore, expression of Fas on the cell surface of the differentiated cells also increased. Overexpression of the HS4C3-binding epitope in mESCs induced apoptosis and spontaneous differentiation even in the presence of LIF and serum. These data showed that the HS4C3-binding epitope was required for differentiation of mESCs. Up-regulation of the HS4C3-binding epitope resulted in the recruitment of Fas from the cytoplasm to lipid rafts on the cell surface followed by activation of Fas signaling. Indeed, the HS4C3-binding epitope interacted with a region that included the heparin-binding domain (KLRRRVH) of Fas. Reduced self-renewal capability in cells overexpressing 3OST resulted from the degradation of Nanog by activated caspase-3, which is downstream of Fas signaling, and was rescued by the inhibition of Fas signaling. We also found that knockdown of 3OST and inhibition of Fas signaling reduced the potential for differentiation into the three germ layers during embryoid body formation. This is the first demonstration that activation of Fas signaling is mediated by an increase in the HS4C3-binding epitope and indicates a novel signaling pathway for differentiation in mESCs.

We present on-chip fluorescence imaging flow cytometry by light-sheet excitation on a mirror-embedded microfluidic chip. The method allows us to obtain microscopy-grade fluorescence images of cells flowing at a high speed of 1 m/s, which is comparable to the flow speed of conventional non-imaging flow cytometers. To implement the light-sheet excitation of flowing cells in a microchannel, we designed and fabricated a mirror-embedded PDMS-based microfluidic chip. To show its broad utility, we used the method to classify large populations of microalgal cells () and human cancer cells (human adenocarcinoma cells). Our method holds promise for large-scale single-cell analysis.

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1The 36 Cl/Cl ratios of groundwater samples were measured by AMS in order to investigate 2 the potential use of 36 Cl as a dating tool for modern groundwater. Groundwater samples were 3 obtained from several piezometers in the Oderbruch in northeastern Germany. The shallow 4 confined aquifer of the area is mainly recharged by the infiltration from the River Oder. From 5 the results of measurements, the pre-bomb and the recent background 36 Cl/Cl ratios in the basin 6 of the Oder were estimated to be 7-9 × 10 −14 . The 36 Cl fallout values estimated from the 36 Cl/Cl 7 ratios of the Oderbruch samples, which were dated by the 3 H/ 3 He method, show good agreement 8 with Dye-3 ice core data. These results suggest that the distribution of 36 Cl in groundwaters 9 reflects the influence of the 36 Cl bomb pulse. This, in turn, suggests that the distribution of 10 36 Cl/Cl in modern groundwaters could reveal groundwater ages and flow systems in a region. 11 12 PACS: 92.40.Kf; 91.67.Qr; 93.30.Ge; 06.60.Ei 13

SYNOPSISPositron lifetimes were measured for four kinds of polyethylene samples and were resolved into four components. The temperature dependence of the two longlived components was examined in detail. In agreement with other results, the longest lived component could be reasonably assigned to ortho-positronium located in amorphous regions. This component was shown to be sensitive to the defects in high-density polyethylene introduced in the course of its production. Both the intensity and the lifetime of the second longest lived component were structure insensitive, i.e., they did not change even on passing through the melting point. This component has been tentatively assigned to a positronium compound state. The effect of gamma-ray irradiation was also examined. Although the intensity (Z4) of the longest lived component was reduced by the irradiation, correlation between Z4 and the free radical concentration was poor, and the reduction in I4 caused by the irradiation is considered to be due to structure change and not to chemical reasons. Keywords: positron annihilation in polyethylene, before and after irradiation polyethylene, positron annihilation in, effect of radiation on 517

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