Dodecagonal quasicrystals of oil-swollen ionic surfactant micelles

A delicate balance of noncovalent interactions directs the hierarchical self-assembly of molecular amphiphiles into spherical micelles that pack into three-dimensional periodic arrays, which mimic intermetallic crystals. Herein, we report the discovery that adding water to a mixture of an ionic surfactant and n-decane induces aperiodic ordering of oil-swollen spherical micelles into previously unrecognized, aqueous lyotropic dodecagonal quasicrystals (DDQCs), which exhibit local 12-fold rotational symmetry and no long-range translational order. The emergence of these DDQCs at the nexus of dynamically arrested micellar glasses and a periodic Frank–Kasper (FK) σ phase approximant sensitively depends on the mixing order of molecular constituents in the assembly process and on sample thermal history. Addition of n-decane to mixtures of surfactant and water instead leads only to periodic FK A15 and σ approximants with no evidence for aperiodic order, while extended ambient temperature annealing of the DDQC also reveals its transformation into a σ phase. Thus, these lyotropic DDQCs are long-lived metastable morphologies, which nucleate and grow from a stochastic distribution of micelle sizes formed by abrupt segregation of varied amounts of oil into surfactant micelles on hydration. These findings indicate that molecular building block complexity is not a prerequisite for the formation of aperiodic supramolecular order, while also establishing the generic nature of quasicrystalline states across metal alloys and self-assembled micellar materials.

Look Over the Horizon - Chicken Linkage Disequilibrium is Much More Complex Over Much Longer Distance than Previously Appreciated

BackgroundAppreciable Linkage Disequilibrium (LD) is commonly found between pairs of loci close to one another, decreasing rapidly with distance between the loci. This provides the basis studies to map Quantitative Trait Loci Regions (QTLRs), where it is custom to assume that the closest sites to a significant markers are the prime candidate to be the causative mutation. Nevertheless, Long-Range LD (LRLD) can also be found among well-separated sites. LD blocks are runs of genomic sites all having appreciable LD with one another. High LD and LRLD are often separated by genomic sites with which they have practically no LD. Thus, not only can LD be found among distant loci, but also its pattern may be complex, comprised of fragmented blocks. Here, chicken LRLD and LD blocks, and their relationship with previously described Marek’s Disease (MD) QTLRs, were studied in an F6 population from a full-sib advanced intercross line, and in eight commercial pure layer lines. Genome wide LRLD was studied in the F6 population by random samples of non-syntenic and syntenic marker pairs. To illustrate the relationship with QTLRs, LRLD and LD blocks in and between the MD QTLRs were studied by all possible marker pairs.Results LRLD was defined as r2 ≥ 0.7 over a distance ≥ 1 Mb, and 1.5% of all syntenic marker pairs were classified as LRLD. Complex fragmented and interdigitated LD blocks were found, ranging over distances from a few hundred to a few millions bases. Vast high, long-range, and complex LD was found between two of the MD QTLRs. Cross QTLRs STRING networks and gene interactions suggested possible origins of the exceptional LD between these two QTLRs.ConclusionsAll sites with high LD with a significant marker should be considered as candidate for the causative mutation, but, unlike the custom assumption, the causative mutation is not necessarily the one closest to the significant marker. Rather, the present results show that it can be located at a much larger distance from a significant marker than previously appreciated, beyond closer mutations. Thus, LRLD range and LD block complexity must be accounted for while interpreting genetic mapping studies.

Complex and long-range linkage disequilibrium and its relationship with QTL for Marek's Disease resistance in chicken populations

Chicken long-range linkage disequilibrium (LRLD) and LD blocks, and their relationship with previously described Mareks Disease (MD) quantitative trait loci regions (QTLRs), were studied in an F6 population from a full-sib advanced intercross line (FSAIL), and in eight commercial pure layer lines. Genome wide LRLD was studied in the F6 population by random samples of non-syntenic and syntenic marker pairs genotyped by Affymetrix HD 600K SNP array. To illustrate the relationship with QTLRs, LRLD and LD blocks in and between the MD QTLRs were studied by all possible marker pairs of all array markers in the QTLRs, using the same F6 QTLR genotypes and genotypes of the QTLR elements' markers in the eight lines used in the MD mapping study. LRLD was defined as r2 ≥ 0.7 over a distance ≥ 1 Mb, and 1.5% of all syntenic marker pairs were classified as LRLD. Complex fragmented and interdigitated LD blocks were found, over distances ranging from a few hundred to a few million bases. Vast high, long-range, and complex LD was found between two of the MD QTLRs. Cross QTLRs STRING networks and gene interactions suggested possible origins of this exceptional QTLRs' LD. Thus, causative mutations can be located at a much larger distance from a significant marker than previously appreciated. LRLD range and LD block complexity may be used to identify mapping errors, and should be accounted for while interpreting genetic mapping studies. All sites with high LD with a significant marker should be considered as candidate for the causative mutation.

Size-control in the synthesis of oxo-bridged phosphazane macrocycles via a modular addition approach

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications due to their ability to encapsulate small molecules or ions within their cavities. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Moreover, current approaches allow little control over the size of the macrocycles formed. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3 + n cyclisation” (n = 1 and 3). Using this method, an all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ethers. Our approach demonstrates that increasing building block complexity enables precise control over macrocycle size, which will not only generate future developments in both the phosphazane and main group chemistry but also in the fields of supramolecular chemistry.

A Facile Modular Addition Approach to Size Control in the Synthesis of Oxo Bridged Phosphazane Macrocycles

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3+n” (n= 1 and 3) condensation reaction synthetic strategy using novel trimeric building blocks. Using this method, the first-ever all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ether counterparts. Our approach demonstrates that increasing building block complexity enables unprecedented rational control over macrocycle size.

A Facile Modular Addition Approach to Size Control in the Synthesis of Oxo Bridged Phosphazane Macrocycles

Inorganic macrocycles remain largely underdeveloped compared with their organic counterparts due to the challenges involved in their synthesis. Among them, cyclodiphosphazane macrocycles have shown to be promising candidates for supramolecular chemistry applications. However, further developments have been handicapped by the lack of synthetic routes to high-order cyclodiphosphazane macrocycles. Here we report the synthesis of high-order oxygen-bridged phosphazane macrocycles via a “3+n” (n= 1 and 3) condensation reaction synthetic strategy using novel trimeric building blocks. Using this method, the first-ever all-PIII high-order hexameric cyclodiphosphazane macrocycle was isolated, displaying a larger macrocyclic cavity than comparable organic crown-ether counterparts. Our approach demonstrates that increasing building block complexity enables unprecedented rational control over macrocycle size.

An Adjustable Interpolation-based Data Hiding Algorithm Based on LSB Substitution and Histogram Shifting

Data hiding can be regarded as a type of image processing techniques. Other image processing operations are usually integrated to increase the embedding capacity or decrease the visual distortion. Interpolation is an example of this type of operation. However, previous interpolation-based data hiding algorithms suffered from low and fixed embedding capacity and high visual distortion. This study proposes a more effective two-stage data hiding algorithm based on interpolation, LSB substitution, and histogram shifting. First, the authors modify the formula for embedding capacity calculation and make some adjustments on the sample pixels determination. A threshold is used to obtain the block complexity and each embeddable pixel has a different amount of message embedded. Second, an LSB substitution method and an optimal pixel adjustment process are adopted to raise the image quality. Finally, the authors' proposed algorithm can support adjustable embedding capacity. Compared to the previous algorithm, the experimental results demonstrate the feasibility of the proposed method.