Lyotropic Liquid Crystals Incorporated with Different Kinds of Carbon Nanomaterials or Biomolecules

Liquid crystals (LCs) are considered as the “fourth state of matter,” which can display properties between crystals and isotropic liquids. LCs can be classified into lyotropic liquid crystals (LLCs) and thermotropic liquid crystals (TLCs), among which LLCs are a kind of self-assemblies formed by amphiphile molecules in a given solvent within certain concentration ranges. The structures and properties of LLCs can be tuned by the incorporation of various kinds of additives, which represents an interesting and novel route for realizing functional composites. This review focuses on recent progress on LLCs-based materials assembled with diverse additives including carbon nanotubes, graphene, graphene oxide, and biomolecules. The thermal stability and mechanical strength of the host LLCs can be greatly improved after the guests are incorporated. In addition, new functions such as conductivity, photothermal effect, and bioactivity can be introduced by the incorporation of the guests, which significantly widens the applications of LLCs-based hybrids in nanotechnology, electrochemistry, drug delivery, and life science

Microstructure refinement by tool rotation-induced vibration in incremental sheet forming

This paper presents a study of employing tool rotation-induced vibrations in incremental sheet forming (V-ISF) to produce sheet metal parts with laminated ultrafine-grained structures. Non-axisymmetric tools were developed to generate tool vibration and surface shear deformation of sheet material during forming. Using the V-ISF process, magnesium sheets of AZ31 were formed to the hyperbolic cones and laminated ultrafine grains with higher micro hardness were obtained by tool generated low frequency vibrations with large amplitudes. To further investigate surface shear deformation induced during processing, the hole-deformation analysis of samples cut from the formed hyperbolic cones was performed. This study found that large surface shear deformation of the sheet and the tool vibration during incremental forming are the two key factors for the formation of laminated ultrafine grains. The developed V-ISF process has a great potential to produce sheet metal parts with refined grains and greater micro hardness

Conceptual design and progress of transmitting ∼\sim MV DC HV into 4 K LHe detectors

A dual-phase TPC (Time Projection Chamber) is more advanced in characterizing an event than a single-phase one because it can, in principle, reconstruct the 3D (X-Y-Z) image of the event, while a single-phase detector can only show a 2D (X-Y) picture. As a result, more enriched physics is expected for a dual-phase detector than a single-phase one. However, to build such a detector, DC HV (High Voltage) must be delivered into the chamber (to have a static electric field), which is a challenging task, especially for an LHe detector due to the extremely low temperature, $\sim$ 4 K, and the very high voltage, $\sim$ MV (Million Volts). This article introduces a convincing design for transmitting $\sim$ MV DC into a 4 K LHe detector. We also report the progress of manufacturing a 100 kV DC feedthrough capable of working at 4 K. Surprisingly, we realized that the technology we developed here might be a valuable reference to the scientists and engineers aiming to build residential bases on the Moon or Mars

Searching for ER and/or NR-like dark matter signals with the especially low background liquid helium TPCs

In the Dark Matter (DM) direct detection community, the absence of convincing signals has become a ``new normal'' for decades. Among other possibilities, the ``new normal'' might indicate that DM-matter interactions could generate not only the hypothetical NR (Nuclear Recoil) events but also the ER (Electron Recoil) ones, which have often been tagged as backgrounds historically. Further, we argue that ER and NR-like DM signals could co-exist in a DM detector's same dataset. So in total, there would be three scenarios we can search for DM signals: (i) ER excess only, (ii) NR excess only, and (iii) ER and NR excesses combined. To effectively identify any possible DM signal under the three scenarios, a DM detector should (a) have the minimum ER and NR backgrounds and (b) be capable of discriminating ER events from NR ones. Accordingly, we introduce the newly established project, ALETHEIA, which implements liquid helium-filled TPCs (Time Projection Chamber) in hunting for DM. Thanks to the nearly single-digit number of ER and NR backgrounds on 1 ton*yr exposure, presumably, the ALETHEIA detectors should be able to identify any form of DM-induced excess in its ROI (Research Of Interest). As far as we know, ALETHEIA is the first DM direct detection experiment claiming such an inclusive search; conventional detectors search DM mainly on the ``ER excess only'' and/or the ``NR excess only'' channel, not the ``ER and NR excesses combined'' channel. In addition, we introduce a preliminary scheme to one of the most challenging R\&D tasks, transmitting 500+ kV into a 4 K LHe detector

A Residue at the Cytoplasmic Entrance of BK-Type Channels Regulating Single-Channel Opening by Its Hydrophobicity

Single large-conductance calcium-activated K+ (BK) channels encoded by the mSlo gene usually have synchronous gating, but a Drosophila dSlo (A2/C2/E2/G5/10) splice variant (dSlo1A) exhibits very flickery openings. To probe this difference in gating, we constructed a mutant I323T. This channel exhibits four subconductance levels similar to those of dSlo1A. Rectification of the single-channel current-voltage relation of I323T decreased as [Ca2+ ]in increased from 10 to 300 μM. Mutagenesis suggests that the hydrophobicity of the residue at the position is important for the wild-type gating; i.e., increasing hydrophobicity prolongs open duration. Molecular dynamics simulation suggests that four hydrophobic pore-lining residues at position 323 of mSlo act cooperatively in a “shutter-like” mechanism gating the permeation of K+ ions. Rate-equilibrium free energy relations analysis shows that the four I323 residues in an mSlo channel have a conformation 65% similar to the closed conformation during gating. Based on these observations, we suggest that the appearance of rectification and substates of BK-type channels arise from a reduction of the cooperativity among these four residues and a lower probability of being open

Efficient homogeneous and isomorphic blocking layer – Skeleton rutile TiO2 electron transfer structure for quantum dot sensitized solar cells

Blocking layer and transfer skeleton of the electron transfer layer are found to play a crucial role in devices efficiency improvement. We develop a homogeneous and isomorphic electron transfer structure of rutile TiO2 by preferred orientation growth in a facile two-step hydrothermal synthesis. The aligned TiO2 nanowire array skeleton (TS) about 2.47 μm long grew neatly over the isomorphic ultra-thin blocking layer (BL). Those homogeneous and isomorphic structures promote the charge injection and transfer capability by means of increased driving force by higher Fermi-level and decreased resistance, in which the cell photocurrent and PCE improve significantly. Of the cells with isomorphic transfer structure, the PCE is 2.87%, the short-circuit current (Jsc) is 6.74 mA/cm2, open-circuit voltage (Voc) is 0.91 V and fill factor (FF) is 38.4% under one sun illumination (100 mW/cm2). Keywords: Electron transfer capability, Homogeneous and isomorphic structure, Fermi level, Device equivalent resistanc

Genetic variation for waxy proteins and starch properties in Chinese winter wheats

Starch properties contribute positively to the quality of both dry and fresh Chinese white noodle quality. Understanding the genetic variation of starch properties in Chinese wheats will therefore facilitate genetic improvement for noodle quality. The composition of waxy protein ( Wx ) subunits, amylose content, and Rapid Visco Analyzer (RVA) properties of a total of 260 wheat cultivars and advanced lines ( Triticum aestivum L) from four Chinese winter wheat regions were characterized. Significant variation was observed for all tested parameters except for peak time. Amylose content, peak viscosity, holding strength, and breakdown values ranged 23.1 to 33.6%, 1151 to 3522cp, 1385 to 2374cp and 192 to 1711cp, respectively. Thirty-nine Chinese wheats conferred the Wx-B1 null mutation, and significant differences in starch properties were observed between the Wx-B1 null wheats and the normal wheats. Data on both waxy protein and starch properties are needed to characterize Chinese wheat germplasm for starch quality and for noodle products. Three cultivars (Guanfeng 2, Yumai 47, and Mianyang 26) had very good starch properties and noodle quality based on our previously report. They could be used as crossing parents in breeding programs targeting for noodle quality improvement

Growth Differentiation Factor-9 Promotes Fibroblast Proliferation and Migration in Keloids through the Smad2/3 Pathway

Background: Keloids are fibroproliferative scars that develop as a result of a dysregulated wound healing process; however, the molecular mechanisms of keloid pathogenesis remain unclear. Keloids are characterized by the ability to spread beyond the original boundary of the wound, and they represent a significant clinical challenge. Previous work from our group suggested that growth differentiation factor (GDF)-9 plays a role in the invasive behavior of keloids. Here, we examined the involvement of GDF-9 in keloid formation and spread and elucidated a potential underlying mechanism. Methods: The expression of GDF-9, cyclooxygenase (COX)-2, vascular epidermal growth factor (VEGF)-C, matrix metalloprotease (MMP)-2, MMP-9, transforming growth factor (TGF)-β1, and the related signaling pathway components in human keloid tissues or keloid fibroblasts (kFBs) was monitored by qRT-PCR and western blot. A series of overexpression and silencing experiments in normal and keloid fibroblasts were used to modify the expression of GDF-9. The effects of GDF-9 on kFB proliferation and migration were assessed using the CCK-8, cell cycle and scratch wound healing assays. Results: GDF-9 promotes fibroblast proliferation and migration. GDF-9 silencing in kFBs decreased cell proliferation, blocked cell cycle progression, downregulated the angiogenic markers COX-2 and VEGF-C, and downregulated MMP-2 and MMP-9 expression, whereas it had no effect on the levels of TGF-β1. GDF-9 silencing significantly inhibited Smad2 and Smad3 phosphorylation in kFBs. Conclusions: GDF-9 promotes the proliferation and migration of kFBs via a mechanism involving the Smad2/3 pathway