Is the σ\sigma meson dynamically generated?

We study the problem whether the $\sigma$ meson is generated `dynamically'. A pedagogical analysis on the toy O(N) linear sigma model is performed and we find that the large $N_c$ limit and the $m_\sigma\to \infty$ limit does not commute. The sigma meson may not necessarily be described as a dynamically generated resonance. On the contrary, the sigma meson may be more appropriately described by considering it as an explicit degree of freedom in the effective lagrangian.Comment: Contribution to ``Quark Confinement and Hadron Spectrum VII'', 2--7 Sept. 2006, Ponta Delgada, Acores, Portuga

Recent progress in the asymmetric Mannich reaction

The asymmetric Mannich reaction is one of the most useful carbon-carbon bond forming reactions for the synthesis of chiral molecules containing nitrogen. The resulting β-amino carbonyl compounds are valuable synthons in the preparation of many natural products with useful biological properties. In recent years, asymmetric Mannich processes have increasingly been reported and used in a rapidly growing number of applications. This review provides an overview of the recent history of the applications of various catalytic systems in asymmetric Mannich reaction, including metal-based asymmetric organocatalysis, asymmetric organocatalysis, other chiral catalysis and no chiral catalysis systems

The “Competition” for Training Cross Border E-commerce Talents in China on the Background of “Internet Plus”

Under the background of “Internet plus,” more and more traditional industries have been integrated into the Internet through information technology. The international trade (foreign trade) industry has constantly been networked, informalized and electrolyzed. Based on the statistical analysis of the current development trend and market demand for cross-border e-commerce talents, this paper attempts to find out the causes of the current multidisciplinary “competition” for cross-border e-commerce talent training, analyze the advantages and disadvantages of this "competition," and put forward the development strategies of multidisciplinary cross-border e-commerce talent training. This study will be of essential reference and significance for applied universities, colleges and higher vocational colleges to adjust the cross-border e-commerce talent training positioning, orientation and professional layout

The role of the haematopoietic microenvironment in megakaryocytopoiesis

Studies the mechanisms regulating megakaryocytopoiesis. Demonstrates that both fibronectin and stromal cells increased and maintained CD34+ cells in culture.Thesis (M.Med.Sc.) -- University of Adelaide, Dept. of Paediatrics, 2001