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Three ion-typed surfactants, including anionic sodium dihexyl sulfosuccinate (SDSS), cationic ammonium salt of poly(ethylene glycol) (ASPEG) and non-ionic poly(ethylene glycol) (PEG), were added to 10 wt% tetramethyl ammonium hydroxide water (TMAHW) solutions to evaluate the silicon anisotropic etching properties of the (1 0 0) silicon plane without agitation and no isopropyl alcohol (IPA) additive. The results indicate that the wetting capacity of the etchants cause the efficacies of the etchants on the roughness reduction to follow the order cationic ASPEG, non-ionic PEG, pure solution and anionic SDSS in TMAHW solutions, especially at high etching temperatures. Moreover, the chemical activities of the etchants cause the efficacies of the etchants on the etching rates to follow the order anionic SDSS, pure solution, cationic ASPEG and non-ionic PEG in TMAHW solutions at a given etching temperature. The cationic ASPEG has a reasonable etching rate of 0.7 µm min−1 and the lowest surface roughness of 4 nm in TMAHW solutions at an etching temperature of 100 °C. ASPEG and PEG in TMAHW solutions markedly affect aluminum passivation. The undercutting of the convex corners in PEG-added TMAHW solutions can be drastically reduced without using corner compensation; the undercutting ratio obtained using a PEG surfactant is about 45% lower than that obtained in pure TMAHW solution. This finding reveals that non-ionic PEG should be added to TMAHW solutions when accurate profiles are required without extremely deep etching. This study also demonstrated that non-ionic PEG is more appropriate than IPA for anisotropic silicon TMAHW etching.

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Background: Postnatal neurogenesis persists throughout life in the subventricular zone (SVZ)-olfactory bulb pathway in mammals. Extrinsic or intrinsic factors have been revealed to regulate neural stem cell (NSC) properties and neurogenesis. Thyroid hormone receptor interacting protein 6 (TRIP6) belongs to zyxin family of LIM proteins, which have been shown to interact with various proteins to mediate cellular functions. However, the role of TRIP6 in NSCs is still unknown. Results: By performing double immunofluorescence staining, we found that TRIP6 was expressed by Sox2-positive NSCs in embryonic and postnatal mouse forebrains. To study the function of TRIP6 in NSCs, we performed overexpression and knockdown experiments with neurospheres derived from postnatal day 7 SVZ. We found that TRIP6 was necessary and sufficient for self-renewal and proliferation of NSCs, but inhibited their differentiation. To further investigate the mechanism of TRIP6 in NSCs, we performed Luciferase reporter assay and found that TRIP6 activated Notch signaling, a pathway required for NSC self-renewal. Conclusions: Our data suggest that TRIP6 regulates NSC maintenance and it may be a new marker for NSCs.

CRL 618 is a well-studied pre-planetary nebula. We have mapped its central region in continuum and molecular lines with the Submillimeter Array at 350 GHz at ∼ 0 ′′ . 3 to 0 ′′ . 5 resolutions. Two components are seen in 350 GHz continuum:(1) a compact emission at the center tracing the dense inner part of the H II region previously detected in 23 GHz continuum and it may trace a fast ionized wind at the base, and (2) an extended thermal dust emission surrounding the H II region, tracing the dense core previously detected in HC 3 N at the center of the circumstellar envelope. The dense core is dusty and may contain mm-sized dust grains. It may have a density enhancement in the equatorial plane. It is also detected in carbon chain molecules HC 3 N and HCN, and their isotopologues, with higher excitation lines tracing closer to the central star. It is also detected in CH 2 CHCN toward the innermost part. Most of the emission detected here arises within ∼ 630 AU (0 ′′ . 7) from the central star. A simple radiative transfer model is used to derive the kinematics, physical conditions, and the chemical abundances in the dense core. The dense core is expanding and accelerating, with the velocity increasing roughly linearly from ∼ 3 km s −1 in the innermost part to ∼ 16 km s −1 at 630 AU. The mass-loss rate in the dense core is extremely high with a value of ∼ 1.15 × 10 −3 M ⊙ yr −1 . The dense core has a mass of ∼ 0.47 M ⊙ and a dynamical age of ∼ 400 yrs. It could result from a recent enhanced heavy mass-loss episode that ends the AGB phase. The isotopic ratios of 12 C/ 13 C and 14 N/ 15 N are 9±4 and 150±50, respectively, both lower than the solar values.