lated and exfoliated PMMA and PS±clay nanocomposites foams were prepared using supercritical CO 2 as the foaming agent. Presence of a small amount of clay nanoparticles greatly reduces foam cell size and increases the cell density. Exfoliated nanocomposites yield foams with the smallest cell size and the highest cell density. Cell morphology can be furthered manipulated by adjustment of polymer±clay surface±CO 2 interaction and foaming conditions to achieve microcellular and submicrocellular foams. The high nucleation efficiency can produce microcellular nanocomposite foams at less stringent processing conditions, leading to cost savings and processing flexibility. ExperimentalMaterials: Methylmethacrylate (MMA), Styrene (St) and 2,2¢-azobisisobutyronitrile (AIBN) were purchased from Aldrich. PS (CX 5197) is from AtoFina Petrochemicals, while PMMA (PL25) is from Plaskolite. Two types of organically modified MMT clays were used. Cloisite 20A (20A) is an MMT modified by dimethyl dihydrogenated tallowalkylammoniumonium cations (Southern Clay Products). Na + ±MMT (cation exchange capacity 92.4 milliequivalent/100 g, from Southern Clay Products) was modified using a reactive cationic surfactant 2-methacryloyloxyethylhexadecyldimethylammonium bromide (MHAB) via ion-exchange reaction [16]. The resulting organoclay is denoted as MHABS. Polymer±20A nanocomposites were prepared using a Leistritz ZSE-27 intermesh twin-screw extruder (L/D = 40, d = 27 mm) in co-rotating mode between 200±220 C and 200 rpm (revolutions per minute) screw speed. In-situ polymerization was carried out to prepare PMMA and PS±MHABS nanocomposites. The monomer, MHABS, and AIBN (0.5 wt.-%) were mixed using a high shear mixer. The mixture was reacted isothermally (60 C for styrene, 50 C for MMA) for 20 h, after which the temperature was raised to 105 C for another 30 min. A two-stage method was also used to prepare PS±MHABS nanocomposites. First a 20 wt.-% nanocomposite masterbatch was prepared by in-situ polymerization. It was then blended with neat PS to prepare nanocomposites with desired clay concentration using a DACA microcompounder at 200 C and 250 rpm. Soxhlet extraction was used to extract non-bonded PMMA from PMMA±MHABS nanocomposites, using dichloromethane as the solvent. The unextractable portion consists of MHABS and a substantial amount of PMMA (64 % of the total weight of the unextractable nanocomposite). The resulting material was blended with neat PS to produce PS±(MHABS±PMMA). (PS±MHABS)±PMMA was prepared via blending a PS±MHABS nanocomposite with PMMA. These two materials have the same weight composition (PS/ PMMA/MHABS = 86:9:5).Foaming of Nanocomposites: The foaming agent, bone-dry grade carbon dioxide, was provided by Praxair. Samples were placed in a stainless steel vessel and CO 2 was delivered via a syringe pump. The system was allowed to equilibrate at the foaming temperature and pressure for sufficient time to ensure equilibrium. The pressure was then rapidly released and the foam cells were fixed by cooling with an ice and ...

Combining the strength of flow cytometry with fluorescence imaging and digital image analysis, imaging flow cytometry is a powerful tool in diverse fields including cancer biology, immunology, drug discovery, microbiology, and metabolic engineering. It enables measurements and statistical analyses of chemical, structural, and morphological phenotypes of numerous living cells to provide systematic insights into biological processes. However, its utility is constrained by its requirement of fluorescent labeling for phenotyping. Here we present label-free chemical imaging flow cytometry to overcome the issue. It builds on a pulse pair-resolved wavelength-switchable Stokes laser for the fastest-to-date multicolor stimulated Raman scattering (SRS) microscopy of fast-flowing cells on a 3D acoustic focusing microfluidic chip, enabling an unprecedented throughput of up to ∼140 cells/s. To show its broad utility, we use the SRS imaging flow cytometry with the aid of deep learning to study the metabolic heterogeneity of microalgal cells and perform marker-free cancer detection in blood.

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Yellow catfish has become one of the most important freshwater aquaculture species in China. The mono-sex male yellow catfish has important application value in aquaculture because the male grows generally faster than the sibling females under the same conditions. This study has screened YY super-male and YY physiological female yellow catfish by sex reversal, gynogenesis, and progeny testing, which can help to achieve the large-scale production of YY super-male and XY all-male. From 2008 to 2010, about 123,000 YY super-male were produced, and about 81 million XY all-male fry were produced with 100% male rate by random sampling. Therefore, these results indicate that YY super-male and YY physiological female yellow catfish can be viable and fertile. We conclude that the mono-sex breeding technique by YY super-male yellow catfish is stable and reliable, which has great potential for application in yellow catfish aquaculture.