Estimates of bilinear pseudodifferential operators associated to bilinear Hörmander classes in Besov and Triebel-Lizorkin spaces with variable exponents.

In this paper, we give Leibniz-type estimates of bilinear pseudodifferential operators associated to bilinear Hörmander classes in Besov and Triebel-Lizorkin spaces with variable exponents. To obtain the estimate for Triebel-Lizorkin spaces with variable exponents, we present their approximation characterization.

Population Structure of and Conservation Strategies for Wild Pyrus ussuriensis Maxim. in China.

Pyrus ussriensis Maxim. is native to the northern part of China, but whose habitats are currently being destroyed by environmental changes and human deforestation. An investigation of population structure and genetic diversity of wild Ussurian pear is a priority in order to acquire fundamental knowledge for conservation. A total of 153 individuals of wild Ussurian pear from the main habitats, Heilongjiang, Jilin, and Inner Mongolia in China, possessed low genetic diversity as a result of habitat fragmentation. The genetic diversity of the populations in Inner Mongolia and north east of Heilongjiang was especially low and there was the possibility of inbreeding. Wild Ussurian pears were divided into 5 groups based on the Bayesian clustering method using 20 nuclear SSRs (nSSRs) and 5 groups by haplotype distributions using 16 chloroplast SSRs (cpSSRs), and the populations in Inner Mongolia and north east of Heilongjiang represented unique genotypes. AMOVA indicated there was a 20.05% variation in nSSRs and a 44.40% variation in cpSSRs among populations. These values are relatively high when compared to those of other tree species. Haplotype E, positioned in the center of the cpSSR analysis network and showed the largest number of connections with other haplotypes, represented the most important haplotype. Inner Mongolia and the north east of Heilongjiang are two areas that need urgent conservation because of their genetic vulnerability and peculiarity. We determined 4 conservation units based on the clustering by nSSRs and cpSSRs, and geographic factor. This information is helpful in deciding the conservation strategies for wild Ussurian pear in China.

Synthesis of 4-alkynylquinazolines: Pd-Cu-cocatalyzed coupling of quinazoline-4-tosylates with terminal alkynes using N-heterocyclic carbenes as ligands.

A Pd-Cu-cocatalyzed coupling reaction of quinazoline-4-tosylates with terminal alkynes using N-heterocyclic carbenes (NHC) as ligands is described, providing 4-alkynylquinazolines in good to excellent yields. This transformation proceeds under mild conditions with high efficiency, which is attractive for focused compound library construction.

Metal cocatalyzed tandem alkynylative cyclization reaction of in situ formed N-iminoisoquinolinium ylides with bromoalkynes via C-H bond activation.

Silver triflate and copper(I) iodide cocatalyzed direct alkynylation and cyclization reaction of in situ formed N-iminoisoquinolinium ylides with bromoalkynes is described. The reaction proceeds efficiently through a combination of C-H activation and subsequent tandem reaction in one pot, leading to diverse H-pyrazolo[5,1-a]isoquinolines in good yields under mild reaction conditions.