Ghost imaging is a technique used to produce an object's image without using a spatially resolving detector. Here we develop a technique we term "ghost cytometry," an image-free ultrafast fluorescence "imaging" cytometry based on a single-pixel detector. Spatial information obtained from the motion of cells relative to a static randomly patterned optical structure is compressively converted into signals that arrive sequentially at a single-pixel detector. Combinatorial use of the temporal waveform with the intensity distribution of the random pattern allows us to computationally reconstruct cell morphology. More importantly, we show that applying machine-learning methods directly on the compressed waveforms without image reconstruction enables efficient image-free morphology-based cytometry. Despite a compact and inexpensive instrumentation, image-free ghost cytometry achieves accurate and high-throughput cell classification and selective sorting on the basis of cell morphology without a specific biomarker, both of which have been challenging to accomplish using conventional flow cytometers.
Gastric MALT lymphoma shows unique features including regression by Helicobacter pylori eradication and API2-MALT1 fusion. We performed a molecular and clinicopathologic study for 115 cases. All eradication-responsive cases were devoid of API2-MALT1 fusion. All tumors positive for the fusion and all negative for H. pylori infection were nonresponsive to the eradication. Consequently, gastric MALT lymphomas were divided into three groups: Eradication-responsive and fusion-negative (group A, n = 72), eradication-nonresponsive and fusion-negative (group B, n = 22), and eradication-nonresponsive and fusion-positive (group C, n = 21). Group A tumors were characterized by low clinical stage and superficial gastric wall involvement, and group C tumors by low H. pylori infection rate, advanced clinical stage, and nuclear BCL10 expression. All group C tumors showed exclusively low-grade histology. Group B tumors, which have not been well recognized, frequently showed nodal involvement, deep gastric wall involvement, and advanced clinical stage, and sometimes an increased large cell component. A multivariate discriminant analysis revealed that responsiveness to the eradication could be predicted accurately by negative API2-MALT1 fusion, positive H. pylori infection, low clinical stage, and superficial gastric wall invasion, the former being the most important factor for the prediction. This 3-group categorization may be helpful for a comprehensive understanding of gastric MALT lymphoma.
UV stabilizers used in food contact plastics were tested for their estrogenic activity by the yeast two-hybrid assay. Among 11 kinds of UV stabilizers, 2-hydroxy-4-methoxybenzophenone and 2,2′-dihydroxy-4-methoxybenzophenone displayed estrogenic activity, while salicylate, benzoate and benzotriazole derivatives and a benzophenone derivative had no activity. Therefore, benzophenone and 19 kinds of hydroxylated derivatives were further studied. Of these, 15 chemicals showed estrogenic activity. The strongest activity was by 2,4-dihydroxybenzophenone, 4hydroxy-4′-chlorobenzophenone, 4-hydroxybenzophenone and 2,3,4-trihydroxybenzophenone. Their activities were stronger than that of bisphenol A which was recognized as a potential endocrine disruptor. The following structureactivity relationships of benzophenones were obtained. The activity of the benzophenones with a hydroxyl group at the 3 or 4-position was positive and rather strong, though that of other benzophenones without a hydroxyl group at the 3 or 4-position was negative or weakly positive. The effect of the hydroxyl group in the phenol moiety were in order of 4-> 3->> 2-position. A hydroxyl group added at the 2-position of the 4-hydroxylated benzene ring enhanced the activity. On the other hand, a hydroxyl group added to the benzene ring of the hydrophobic moiety reduced the binding, while the chloro group enhanced it. Some of these relationships might possibly hold for other estrogenic chemicals that possess two benzene rings.
Polylactide (PLA) is used for manufacturing lunch boxes and for packaging fresh food in Japan. PLA can be hydrolysed relatively easily to produce lactic acid, lactide and oligomers. Different types of PLA sheet were subjected to migration tests under various conditions and the lactic acid, lactide and oligomers contents of the migration solutions were determined using liquid chromatography/mass spectrometry (LC/MS). Furthermore, the change in molecular weight was determined by a migration test. PLA was stable at 40 degrees C for 180 days; the total of lactic acid, lactide and oligomers migration levels were 0.28-15.00 microg cm(-2). PLA decomposed clearly at 60 degrees C for only 10 days, the total migration levels were increased to 0.73-2840 microg cm(-2). PLA sheets with a high D-lactic acid content decomposed particularly rapidly. The amounts of alkali decomposition products, based on the conversion of lactide and oligomers to lactic acid by alkali hydrolysis, corresponded with the total migration levels.
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