Total Synthesis of Norsampsones A and B, Garcinielliptones N and O, and Hyperscabrin A

The asymmetric total synthesis of five decarbonyl polycyclic polyprenylated acylphloroglucinols norsampsnes A (3) and B (4), garcinielliptones O (5) and N (6), and hyperscabrin A (7) is described. The synthesis to construct the core substituted cyclohexanone ring of these natural products was achieved by a key Dieckmann condensation. The chirality of the molecules was introduced by the stereoselective alkylation with Evans' oxazolidinones. The synthesis could be run on grams scale, and the Dieckmann condensation was investigated through the DFT calculations to help improve the yield of garcinielliptone O (5). Determination of the absolute configuration of garcinielliptones O (5) and N (6) was also achieved.

Enhancement of fluorescence emission difference microscopy using conjugated vortex phase modulation

In this paper, we propose and demonstrate an improved fluorescence emission difference microscopy (FED) method, exploiting programmable phase modulation for image enhancement. The main novelty of the proposed approach lies in the matched size and intensity of two excitation spots. The proposed method improves the FED performance on image quality via artefact elimination. We demonstrate the feasibility of this method through theoretical studies and experimental tests. The experimental results of nanobeads and cells validate the practical performance of this method, which can enable reliable observations at superresolution in biomedical studies. LAY DESCRIPTION: In this paper, we propose a method to improve the imaging quality of regular fluorescence emission difference (FED) microscopy. In regular FED imaging, a solid and a doughnut excitation beam are successively used to acquire two images which are then subtracted with each other to improve the resolution of confocal microscopy. The doughnut beam can be generated by modulating the excitation beam with a vortex phase mask. Note that both of the excitation beam and the vortex phase mask must have the same handed direction in regular FED microscopy. However, some negative values may be produced and some information may be lost due to the subtraction process in regular FED imaging, which is mainly caused by the mismatched size and intensity of these two excitation spots. To address this issue, we propose conjugated FED (cFED) microscopy which additionally uses a conjugated vortex phase mask to modulate the solid beam to extend its focal spot size to be matched with the doughnut spot, which means the handed direction of the solid beam and the vortex phase mask is different. Besides, in order not to damage the resolution, the doughnut beam needs to be saturated to some degree. The experiment results show that, at the same resolution level, the negative values and the information loss in cFED image are all less than that of regular FED image.

Comparative Study for the Association of Mitochondrial Haplogroup F+ and Metabolic Syndrome between Longevity and Control Population in Guangxi Zhuang Autonomous Region, China

BACKGROUND

Our previous study suggested that mitochondrial haplogroup F (mtDNA F) was a longevity-associated biomarker, but the effect of mitochondrial haplogroup F on longevity individuals with metabolic syndrome (MetS) was not clear. Thus we explored the association between mtDNA F and MetS among longevity and control population in Guangxi Zhuang Autonomous Region, China.

METHOD

A total of 793 individuals consisting of 307 long-lived participants and 486 local healthy controls were involved in this study. Genotypes of mtDNA F were amplified by polymerase chain reaction and Sanger sequenced. MetS was defined according to the revised National Cholesterol Education Program's Adult Treatment Panel III (NCEP ATPIII ) criteria.

RESULTS

The prevalence of MetS in longevity group (28.0%) was higher than that (18.5%) in control group (P=0.002). Through the case-control stratify analysis, the prevalence of MetS in mtDNA F+ longevity individuals (29.8%) was 4.6 fold higher than that (5.3%) in local control group (P<0.001). However, after further longevity-only analysis, no association between MetS and mtDNA F+ in longevity group was observed (P=0.167). Following same analysis of two variables in control group, we found that the prevalence of MetS in mtDNA F- (95.8%) was higher than that in mtDNA F+ (5.3%); conversely, the prevalence of non-metabolic syndrome (NMetS) in mtDNA F+ (94.7%) was markedly higher than that in mtDNA F- (4.2%) (P<0.001).

CONCLUSION

We demonstrated that mtDNA F+ , as a molecuar biomarker, might not only confer beneficial effect to resistance against MetS but also function as a positive factor for long-life span among the population in Guangxi Zhuang Autonomous Region, China.