Visible-light-promoted synthesis of secondary and tertiary thiocarbamates from thiosulfonates and N-substituted formamides.

A general visible-light-promoted metal-free synthesis of secondary and tertiary thiocarbamates starting from thiosulfonates and N-substituted formamides is developed. By employing rhodamine B as a photocatalyst and tert-butyl hydroperoxide (TBHP) as an oxidant, a wide scope of thiocarbamates can be obtained through direct thiolation of acyl C-H bonds under irradiation of blue light at room temperature for 12 h.

[The Influence of Short-term Orthokeratology on Tear Film in Adult Myope].

OBJECTIVE: To study the changes of tear film after short-term overnight orthokeratology wearing in adult myope. METHODS: Fifty adult myope aged 18 to 38 years old were enrolled in this study. The patients wore orthokeratology 6-10 h every night during this study. Data such as non-invasive tear break-up time (NITBUT), fluorescent tear break-up time (FTBUT), lower tear meniscus height (LTMH), corneal fluorescent staining as well as ocular surface disease index (OSDI) questionnaire score were measured at baseline, 1 d, 7 d, 14 d, 30 d and 90 d. RESULTS: Forty-four subjects completed the follow-up study. Tear break-up time (TBUT) decreased and became stable at 14 d after overnight orthokeratology wearing. LTMH sustained decreased and there was a difference after 90 d overnight wearing （ P<0.05）. Compared with baseline, the grade of corneal staining increased at all time points （ P<0.05）. As for the OSDI score, there was no difference at all time points. CONCLUSION: After overnight orthokeratology wearing, tear film stability and tear secretion decreased. Adult myope seems easily to suffer corneal injury after overnight orthokeratology wearing.

Isolation and characterization of Bacillus subtilis strain 1-L-29, an endophytic bacteria from Camellia oleifera with antimicrobial activity and efficient plant-root colonization.

Endophytic bacteria, which are common in plant tissues, may help to control plant pathogens and enhance plant growth. Camellia oleifera, an oil-producing plant, is widely grown in warm, subtropical, hilly regions in China. However, C. oleifera is strongly negatively affected by C. oleifera anthracnose, which is caused by Colletetrichum fructicola. To find a suitable biocontrol agent for C. oleifera anthracnose, 41 endophytes were isolated from the stems, leaves, and roots of C. oleifera. Bacterial cultures were identified based on analyses of 16S rDNA sequences; most strains belonged to the genus Bacillus. The antagonistic effects of these strains on C. fructicola were tested in vitro. In total, 16 strains inhibited C. fructicola growth, with B. subtilis strain 1-L-29 being the most efficient. Strain 1-L-29 demonstrated antagonistic activity against C. siamense, C. asianum, Fusarium proliferatum, Agaricodochium camellia, and Pseudomonas syringae. In addition, this strain produced indole acetic acid, solubilized phosphate, grew on N-free media, and produced siderophores. To facilitate further microecological studies of this strain, a rifampicin-resistant, green fluorescent protein (GFP)-labeled strain, 1-L-29gfpr, was created using protoplast transformation. This plasmid had good segregational stability. Strain 1-L-29gfpr was re-introduced into C. oleifera and successfully colonized root, stem, and leaf tissues. This strain remained at a stable concentration in the root more than 20 d after inoculation. Fluorescence microscopic analysis showed that strain 1-L-29gfpr thoroughly colonized the root surfaces of C. fructicola as well as the root vascular tissues of Arabidopsis thaliana.

[Soil microfauna diversity among Cunninghamia lanceolata plantations based on pyrosequencing].

In order to study the function of soil microfauna and its responses to environmental changes, we used metagenome analyses of the 18S rDNA gene region to identify differences in microfauna diversity and community structure among fifteen soil samples belonging to five different Cunninghamia lanceolate plantations. The plantations were located in Youxian County, Hunan Province in central China. The trees in these plantations were of different ages (3, 13, and 26 years) and belonged to different ecological successions (first, second, and third successions). The total dataset comprised 94922 high quality sequences with an average length of 436 bp. The dominant taxonomic groups across all samples were Chordata, Annelida, Arthropoda, Nematoda, Rotifera and Platyhelminthes with each accounting for 60.8%, 24.0%, 7.4%, 3.6%, 1.5% and 1.2% of the sequences, respectively. There were significant differences in ACE index and Shannon index among the five plantations. The lowest diversity of soil microfauna was in the 13-year old plantation of the first ecological succession. The correlation analysis showed that both ACE and available potassium concentration were negatively correlated to the Chaol index. However, there were no significant correlations between the Shannon, Simpson indices and the physical-chemical properties of soil. Overall, the Jaccard's similarity coefficient was less than 0.4 among samples at each site, and significant differences were found among plantations.