Biomedical subjects

Fei Shi

Publications and source records attributed to Fei Shi.

4 recordsLinked to original sources

PubMed2026

A CqbZIP55-CqPIF3 regulatory module associated with light-responsive flavonoid biosynthesis during quinoa seedling de-etiolation.

Quinoa (Chenopodium quinoa) is an emerging leafy vegetable and microgreen crop rich in health-promoting flavonoids, yet the regulatory mechanisms linking light perception to early metabolic adaptation remain unclear. Here, we integrated phenotypic, transcriptomic, metabolomic, and molecular analyses to investigate early de-etiolation responses in quinoa seedlings. Short-term light exposure rapidly promoted seedling establishment and induced transcriptional programs associated with photosynthesis, carbon metabolism, hormone signaling, and flavonoid biosynthetic gene expression, whereas metabolite changes were more limited, indicating temporal uncoupling between transcriptional activation and metabolic accumulation. Genome-wide bZIP analysis identified CqbZIP55 as a light-responsive regulator that directly binds and activates the CqCHS promoter. CqPIF3 also bound the CqCHS promoter and showed stronger transactivation activity than CqbZIP55 in transient reporter assays. Protein interaction and dual-luciferase assays showed that CqbZIP55 physically interacts with CqPIF3 and modulates CqPIF3-associated promoter activity. Exogenous quercetin upregulated CqbZIP55 and prolonged CqCHS expression, suggesting a candidate metabolite-associated reinforcement mechanism. Together, these findings support functional interplay between CqbZIP55 and CqPIF3 in light-responsive regulation of flavonoid biosynthetic gene expression in quinoa seedlings, while further quinoa-based perturbation and in vivo promoter-occupancy assays are required to establish their physiological role in planta. This study provides a framework for further investigation of photoprotective metabolic regulation in quinoa.

Chenopodium quinoa↗

PubMed2006

Eruptive cherry angiomas associated with vitiligo: provoked by topical nitrogen mustard?

We report a 27-year-old man who had suffered with vitiligo for 7 years and with eruptive cherry angiomas within or around the repigmented vitiliginous skin for 2 years. After continual therapy for vitiligo with topical nitrogen mustard in a concentration of 0.001% for 5 years, multiple cherry angiomas erupted within or around the repigmented vitiliginous plaques. The discontinue therapy with nitrogen mustard stopped the appearance of new cherry angiomas. The presence of eruptive cherry angiomas was evident and was confirmed by histopathology. We suggest that the chronic chemical stimuli caused by topical nitrogen mustard might result in the formation of eruptive cherry angiomas.

Adult↗

PubMed2004

[A new impulse noise filter based on pulse coupled neural network].

This paper presents a new impulse noise filter based on pulse coupled neural networks according to the apparent difference of gray value between noised pixels and the pixels around them. Comparing with the state-of-the-art denoised PCNN filter, the step by step modifying algorithm based on PCNN also, the new PCNN filter suggested in this paper costs less computation and less execution time. At the same time this new PCNN filter has been compared with other nonlinear filters, such as median filter, the stack filter based on omnidirectional structural elements constrains, the Omnidirectional morphology Open-Closing maximum filter (OOCmax) and the Omnidirectional morphology Close-Opening minimum (OCOmin) filter. The results of simulation shows that this algorithm is superior to standard median filter, the state-of-the-art PCNN filter, the maximal, minimal morphological filter with omnidirectional structuring elements, and the optimal stack filter based on omnidirectional structural elements constrains in the aspect of the impulse noise removal. What is more important is that this algorithm can keep the details of images more effectively.

Computer Simulation↗

PubMed2004

[Study on atmospheric photo-oxidation of methyl hydroperoxide initiated by Cl-atom].

Organic peroxides play an important role in chemistry of the atmosphere and in controlling urban air quality; however, accurate knowledge about their atmospheric reactions is lacking. In this paper, the experimental simulation was employed to study the atmospheric photo-oxidation of methyl hydroperoxide (CH3OOH, MHP), a key organic peroxide in the atmosphere. At the temperature of (292 +/- 2) K and pressure of 9.3 x 10(4) Pa (20% O2 + 80% N2), the MHP photo-oxidation was initiated by Cl-atom and the process of reaction was in-situ observed by long path Fourier transform infrared (Long Path FTIR) spectrometry. From FTIR spectra, the main products observed were formaldehyde (HCHO), formic acid (HCOOH), carbon monoxide (CO) and carbon dioxide (CO2), and minor methanol (CH3OH) was found as well. Within the reaction period of 60 min, yields were determined: 24% for HCOOH and 6% for CO; 50% for HCHO at its maximum concentration although its yield was varying with the reaction time. Finally, reaction mechanisms were discussed, which implied that MHP is a reservoir of odd-hydrogen radicals (HOx) and plays an important role in atmospheric photo-reactions.

Atmosphere↗