Ferroelectric columnar liquid crystal featuring confined polar groups within core-shell architecture

Ferroelectric liquid crystals are materials that have a remnant and electrically invertible polar order. Columnar liquid crystals with a ferroelectric nature have potential use in ultrahigh-density memory devices, if electrical polarization occurs along the columnar axis. However, columnar liquid crystals having an axial nonzero polarization at zero electric field and its electrical invertibility have not been demonstrated. Here, we report a ferroelectric response for a columnar liquid crystal adopting a core-shell architecture that accommodates an array of polar cyano groups confined by a hydrogen-bonded amide network with an optimal strength. Under an applied electric field, both columns and core cyano groups align unidirectionally, thereby developing an extremely large macroscopic remnant polarization.     

Identification of new Pina null mutations among Asian common wheat cultivars

Wheat grain hardness is one of the most important phenotypes related to milling, baking and noodle making. Either a mutation of the Puroindoline-a (Pina) gene or Puroindoline-b (Pinb) gene results in hard grain texture. A deletion mutation of Pina (Pina-D1b) is widely distributed among common wheat cultivars. Although North/South American and Australian cultivars and their descendants have a 15-kbp deletion in common, two new types of deletion mutation were found among Asian wheat cultivars. A 4.4-kbp deletion was found in one Korean and two Chinese wheat cultivars beginning at position +371 within the Pina coding region. The other, a 10.4-kbp deletion, was found in three Chinese and nine Japanese wheat cultivars, including five Japanese landraces, beginning at position −5112. It caused the deletion of the full-length Pina gene. These findings suggest that Asian wheat cultivars are genetically distinct from those in other regions. The 4.4-kbp and 10.4-kbp deletion mutants were designated as Pina-D1r and Pina-D1s, respectively.     

新疆小麦地方品种资源HMW-GS的遗传多样性组成分析

为了明确新疆小麦地方品种高分子量麦谷蛋白亚基的遗传多样性,并为小麦品质改良提供基础材料,利用十二烷基硫酸钠聚丙烯酰胺凝胶电泳(SDS-PAGE) 技术,分析了源自新疆地区的282份小麦地方品种的高分子量麦谷蛋白亚基组成。结果表明,在Glu-A1、Glu-B1和Glu-D1位点上的等位变异分别为3、6和 5种,三个位点上的优势亚基依次为null、7+8和2+12,其频率分别是75.5%、90.8%和72.0%。在Glu-1位点共检测到20种亚基组合,其中(null, 7+8, 2+12)组合的频率最高,为52.8%, 其次是(null, 7+8, 2.6+12)和(2*, 7+8, 2+12)组合,其频率分别为14.1%和11.0%,其它亚基组合的频率均低于10%。另外,在Glu-D1位点上还检测到一个新的亚基2.6+12。在供试的282份新疆地方品种中发现了两份具有优质亚基组合的材料,它们的亚基组成为(2*, 7+9, 5+10)和(1, 7+9, 5+10),这些地方品种可作为改良小麦品质性状的重要遗传资源。     

Formation of a one-dimensional array of oxygen in a microporous metal-organic solid

We report the direct observation of dioxygen molecules physisorbed in the nanochannels of a microporous copper coordination polymer by the MEM (maximum entropy method)/Rietveld method, using in situ high-resolution synchrotron x-ray powder diffraction measurements. The obtained MEM electron density revealed that van der Waals dimers of physisorbed O2 locate in the middle of nanochannels and form a one-dimensional ladder structure aligned to the host channel structure. The observed O-O stretching Raman band and magnetic susceptibilities are characteristic of the confined O2 molecules in one-dimensional nanochannels of CPL-1 (coordination polymer 1 with pillared layer structure).     

新疆冬小麦地方品种高分子量麦谷蛋白亚基的地理分布及其新发现亚基的特性

[目的]和方法]为了揭示新疆小麦地方品种高分子量谷蛋白亚基( HMW - GS)的遗传多样性,对新疆北部地区(北疆)、东部地区(东疆)和南部地区(南疆)小麦地方品种HMW - GS的分布进行了研究.[结果]研究表明:新疆小麦地方品种HMW - GS等位变异的分布与其地理来源具有密切关系,除Glu - B1位点外,Glu -A1和Glu - D1位点等位变异在北部地区、东部地区和南部地区的分布频率存在显著差异.在Glu - A1位点,Glu - A1c编码的亚基出现的频率最高,其次是Glu - A1b编码的2*亚基;但在北部地区,几乎所有品种都含有Glu -A1c编码的亚基,仅有1个品种含有Glu-A1b编码的2*亚基.在Glu - B1位点,新疆大多数小麦地方品种含有Glu -B1b编码的7+8亚基.在Glu - D1位点,新发现的等位基因Glu -D1bp(t)编码的2.6亚基在东疆和南疆出现的频率较高,但在北疆出现的频率最低,分别为91;(东疆),61;(南疆),19;(北疆);等位基因Glu - D1bp(t)在南疆冬小麦地方品种中普遍存在.然而,北疆是以等位基因Glu - D1a编码的2+12亚基为主,其频率为83;.关于Glu - D1bp(t)的起源,推测可能是在南疆地区自然突变产生,然而由于南疆和东疆荒漠化造成的地理阻碍使其向北疆传播的概率较低,同时抑制了该基因向东亚地区的迁移.[结论]基于DNA序列的氨基酸序列比对,发现Glu -D1bp(t)编码的2.6亚基与Glu - D1al编码的2.2*亚基非常相似.