Characterizations and Analysis of the Mold from Animal Specimens in Shenzhen Museum

Biological specimens play an important role in cultural exchange, science popularization, scientific research and economic window, but the preparation and preservation technology system of biological specimens is relatively unsafe and inefficient. Mold grows seriously on animal specimens, which is not only harmful to human beings’ health and environment, but also is one of the factors that restricts the development of the natural history museums where these specimens are kept. This paper identified the mold species of animal specimens by PCR with ITS primers, bio-micro-scopic observation, sequencing and phylogenetic tree analysis. The results showed the mold of animal specimens mainly belonged to Aspergillus and Neurospora. This study established the foundations of controlling and restoring the mold that infected animal specimens and guided a new methodology of preparation and environmental friendly exhibition for animal specimens.

A Note on Finitely Generated Modules over a <i>PID</i>

In this note, we provide an effective proof of the fundamental structure theorem of finitely generated modules over a principal ideal domain, from which we find the minimality of decomposition for a finitely generated module over a principal ideal domain.

A Minimality of the Rational Canonical Form

The rational canonical form theorem is very essential basic result of matrix theory, which has been proved by different methods in the literature. In this note, we provide an effcient direct proof, from which the minimality for the decomposition of the rational canonical form can be found.

H3K27me3 shapes DNA methylome by inhibiting UHRF1-mediated H3 ubiquitination

DNA methylation and histone lysine tri-methylation at H3K27(H3K27me3)are two chromatin modifications for transcriptional gene silencing,which play important roles in diverse biological processes,including cell fate determination and cell lineage commitment.These two marks are largely mutually exclusive and target distinct sets of genes in the mammalian genome.However,how H3K27me3 shapes the DNA methylome remains elusive.Here,we report that the loss of H3K27me3 modification leads to increased DNA methylation at previously marked H3K27me3 sites,indicating that H3K27me3 negatively regulates DNA methylation.Genome-wide analysis of H3 ubiquitination,essential for recruitment and activation of DNA methyltransferase DNMT1,reveals the absence of H3 ubiquitination at H3K27me3 marked nucleosomes.Moreover,loss of H3K27me3 modification induces an increase in H3K18 ubiquitination at the corresponding hyper-methylated loci.Importantly,we show that H3K27me3 directly inhibits UHRF1-mediated H3 ubiquitination toward nucleosomes in a defined biochemical assay.Taken together,our findings reveal a general mechanism for H3K27me3-mediated shaping of the mammalian DNA methylome via modulation of H3 ubiquitination.

Automorphisms and Verma Modules for Generalized 2-dim Affine-Virasoro Algebra

We study the structure of the generalized 2-dim affine-Virasoro algebra, and describe its automorphism group. Furthermore, we also determine the irreducibility of a Verma module over the generalized 2-dim affine-Virasoro algebra.

A Robust Superhydrophobic Smart Coating with Reversible Thermochromic and Photochromic Property

Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big obstacle.Inspired by the lotus leaf,to endow the chromic coating with superhydrophobicity is a possible solution.In this research,a dual response coating was prepared by adding photochromic and thermochromic particles simultaneously.The prepared sample demonstrated at least four-state color switching,which can be successfully used in tactile imaging,multi-color fabric,erasable record,and security labels.The superhydrophobicity was achieved by introducing vinyl-terminated polydimethylsiloxane,which not only offers low surface energy but also can cross-link with the particles to increase the adhesion.Thus,the prepared sample maintained superhydrophobicity after various kinds of destruction(such as sandpaper abrasion,corrosive liquid attack,ultrasonic treatment,UV irradiation,and high-speed drops/turbulent jets impact).Even though the superhydrophobicity can be destroyed by plasma etching,it can be recovered after 12 h at room temperature.

Level-1/2 Realization of Quantum N-Toroidal Algebra in Type C_(n)

We construct a level-1/2 vertex representation of the quantum N-toroidal algebra of type C_(n),which is a natural generalization of the usual quantum toroidal algebra.The construction also provides a vertex representation of the quantum toroidal algebra for type C_(n) as a by-product.