Stereoselective synthesis of 2,8-dioxabicyclo[3.3.1]nonane derivatives via a sequential Michael addition/bicyclization reaction.

A highly efficient and stereoselective synthesis of coumarin-, 1,3-cyclohexanedione-, and 1,4-naphthoquinone-fused 2,8-dioxabicyclo[3.3.1]nonanes is described. This was achieved via a sequential Michael addition/bicyclization reaction from easily accessible 3-(2-hydroxyphenyl)-1-phenylprop-2-en-1-one derivatives. Three chemical bonds (one C-C bond and two C-O bonds), two six-membered cycles, and two stereogenic centers were formed in a one-pot operation.

[Observation of acupoint application of gel plaster on insomnia].

OBJECTIVE: To observe the effect of acupoint application of gel plaster on quality of sleep and life in patients with insomnia. METHODS: A total of 63 patients with insomnia were randomized into a gel plaster group (32 cases, 1 case dropped off) and a placebo plaster group (31 cases). Acupoint application of gel plaster was applied at Yintang (GV 29) and Yongquan (KI 1) in the gel plaster group, placebo plaster was applied at the same acupoints in the placebo plaster group. The treatment was given from bedtime to early moming of the next day, 5 days were as one course, with 2-day interval, totally 4 courses were required in the both groups. Pittsburgh sleep quality index (PSQI), Epworth sleepiness scale (ESS) and Flinders fatigue scale were used to evaluate the sleep quality and fatigue level of the patients in the both groups before and after treatment and at 2 weeks of follow-up. The variations of insomnia TCM syndrome score and the 36-item short-form health survey (SF-36) score before and after treatment were observed. RESULTS: Compared before treatment, the scores of PSQI, ESS and FFS after treatment and at follow-up were decreased in the both groups (P<0.01), and the variations of PSQI total scores and ESS scores in the gel plaster group were larger than those in the placebo plaster group (P<0.05). Compared before treatment, the insomnia TCM syndrome scores were decreased (P<0.01), the scores of physiological function, physiological role, general health, role emotion, mental health of SF-36 were improved after treatment in the both groups (P<0.05), and the social function score after treatment in the gel plaster group was superior to that in the placebo plaster group (P<0.05). CONCLUSION: Acupoint application of gel plaster can effectively improve the quality of sleep and life in patients with insomnia.

Nighttime safety evaluation for signalized intersections at the signal cycle level based on rear-end conflict models considering lighting and traffic conditions.

Objective: The primary objective of this study is to explore the effects of the lighting level on nighttime safety of signalized intersections based on conflict models under traffic conditions varying in cycles.Method: Nighttime data were collected from a field study at six signalized intersections in Nanjing, Jiangsu Province in China. Nighttime rear-end conflict models were developed by adopting the generalized linear model (GLM) approach to relate the frequency of rear-end traffic conflicts to lighting level, traffic volume and platoon ratio at the signal cycle level.Results: The final model consisting of all explanatory variables, including lighting level, traffic volume, and platoon ratio demonstrates a better performance of safety evaluation when compared to the model considering traffic volume only and the model with traffic volume and an additional variable of lighting or traffic conditions. Nighttime safety of signalized intersections is expected to improve with larger platoon ratios and higher lighting levels. A potential application of the final model was further explored by benefit-cost analyses. The analyses provided a hypothetical recommended lighting level under various traffic volumes and platoon ratios when safety benefit equals lighting system cost.Conclusions: Nighttime safety can be evaluated using the developed rear-end conflict models, which relate the number of rear-end conflicts to traffic and lighting variables. The number of rear-end conflicts can be calculated by the final conflict model with lighting level, traffic volume, and platoon ratio. The developed model can be potentially applied to provide further insights on the lighting management for intersection safety optimization with traffic conditions varying in signal cycles via vehicle-to-infrastructure (V2I) communications.

[Hereditary hemorrhagic telangiectasia caused by mutation in intron 4 of ALK1 gene: analysis of a HTT family].

OBJECTIVE: To investigate the molecular pathogenesis of hereditary hemorrhagic telangiectasia (HHT). METHODS: Peripheral blood samples were collected from a HTT family, including the proband, female, aged 48, and her mother, elder brother, elder sister, younger brother, and son. HHT gene mutations were identified by PCR-SSCP and DNA sequencing and confirmed by reverse sequencing. Ectopic transcripts of RT-PCR were used to confirm the characteristics of the mutation in non-canonical splicing site (IV S4 + 3 a > t). RESULTS: A mutational segment of PCR product of exon 4, exon-intron boundaries and the 3', 5' untranslated sequence of ALK1 gene was identified by PCR-SSCP. The mutational segment was analyzed by DNA sequencing. An IV S4 + 3 a > t mutation was found, causing splicing abnormality of intron 4 and exon 3 skipping. CONCLUSION: A splicing pattern of the IV S4 + 3 a > t mutation has been reported among Chinese HHT2 patients for the first time.

[Investigation of canine mesenchymal stem cells differentiation to vascular endothelial cell in vitro].

To induce endothelial cell, canine bone marrow-derived mesenchymal stem cells (MSCs) were separated from bone marrow by density gradient centrifugation. The isolated MSCs were induced to form endothelial-like cell in the presence of vascular endothelial growth factor (VEGF), endothelial growth factor (EGF) and so on. These results showed that the cells uniformly took on a cobblestone morphology under the light microscope, and cell nucleolus was in the middle of the cells. The cells displayed Weibel-Palade bodies under the transmission electron microscope. vWF, a specific marker of endothelial cell was positive in the cells. The above results demonstrate that MSCs may be differentiated into endothelial cells in vitro.