Thermally induced transformation of a Cu4I4-based cluster to a Cu2I2-based cluster under mild conditions.

A reaction of 6,6'-bis((benzylthio)methyl)-2,2'-bipyridine (L) with CuI at room temperature led to one Cu4I4-based cluster, which could be thermally transformed to a Cu2I2-based one under mild conditions due to the formation of a Cu-S bond. Along with the structural transformation, remarkable changes in the color and luminescence have been triggered.

Bottom-up and top-down factors of motion direction learning transfer.

Perceptual learning of motion discrimination has long been believed to be motion direction specific. However, recent studies using a double-training paradigm, in which the to-be-transferred condition was experienced through practicing an irrelevant task, found that perceptual learning in various visual tasks, including motion direction discrimination, can transfer completely to new conditions. This transfer occurred when the transfer stimulus was subconsciously presented, or when top-down attention was allocated to the transfer stimulus (which was absent). In the current study, observers were exposed subconsciously, or directed top-down attention, to the transfer motion direction, either simultaneously or successively with training. Data showed that motion direction learning transferred to the transfer direction, and suggest that motion direction learning specificity may result from under-activations of untrained visual neurons due to insufficient bottom-up stimulation and/or lack of top-down attention during training. These results shed new light on the neural mechanisms underlying motion perceptual learning and provide a constraint for models of motion perceptual learning.

The effect of genetically modified Lactobacillus plantarum 590 on the gut health of Sprague-Dawley rats.

Lp was a generally recognized as safe microorganism. Lactobacillus plantarum 590 was obtained by inserting nisI gene into Lp genome to help it tolerate higher concentration nisin. As the unintended effects of the genetically modified microorganism (GMM) are the most important barriers to the progress of GMM, we have performed a useful exploration to establish a new in vivo evaluation model for GMM from the point of view of intestinal health. In this study, Sprague-Dawley rats were orally administered with Lp 590 and Lp for 4 weeks. Fecal samples were collected to determine the number of beneficial bacteria Bifidobacterium and harmful bacteria Clostridium perfringens. Denaturing gradient gel electrophoresis was used to detect the bacterial profiles of every group. Fecal enzyme activities and short-chain fatty acids as main metabolites were also examined. Real time PCR (RT-PCR) and immunohistochemistry were used to analyze two proteins (ZO-1 and occludin) and secretory immunoglobulin A to detect intestinal permeability and mucosal immunity, gut permeability and gut mucosal immunity were analyzed to see whether GM Lp 590 can induce changes of the gut health when compared with non-GM Lp group, andeventually we concluded that there is no significant difference between GM Lp 590-fed group and non-GM Lp-fed group. The conclusion of gut health test was comparable withthat from traditional subchronic test. Evaluation of intestinal health will be a new approach of assessing the safety of GMM.