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71.
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Fei-Ying Yang Jun-Hui Chen Qian-Qian Ruan Hafiz S. A. Saqib Wei-Yi He Min-Sheng You 《Archives of insect biochemistry and physiology》2020,103(4):e21643
Mass spectrometry imaging (MSI) can visualize the composition, abundance, and spatial distribution of molecules in tissues or cells, which has been widely used in the research of life science. Insects, especially the agricultural pests, have received a great deal of interests from the scientists in biodiversity and food security. This review introduces the major characteristics of MSI, summarizes its application to the investigation of insect endogenous metabolites, exogenous metabolites, and the spatiotemporal changes of metabolites between insects and plants, and discusses its shortfalls and perspectives. The significance of these concerns is beneficial for future insect research such as physiology and metabolism. 相似文献
73.
Jiaqi You Kevin Mallery Douglas G. Mashek Mark Sanders Jiarong Hong Miki Hondzo 《Biotechnology and bioengineering》2020,117(4):i-i
Microalgae have been shown as a potential bioresource for food, biofuel, and pharmaceutical products. During the growth phases with corresponding environmental conditions, microalgae accumulate different amounts of various metabolites. We quantified the neutral lipids accumulation and analyzed the swimming signatures (speed and trajectories) of the motile green alga, Dunaliella primolecta, during the lag–exponential–stationary growth cycle at different nutrient concentrations. We discovered significant changes in the neutral lipid content and swimming signatures of microalgae across growth phases. The timing of the maximum swimming speed coincided with the maximum neutral lipid content and both maxima occurred under nutrient stress at the stationary growth phase. Furthermore, the swimming trajectories suggested statistically significant changes in swimming modes at the stationary growth phase when the maximum intracellular neutral lipid content was observed. Our results provide the potential exploitation of microalgal swimming signatures as possible indicators of the cultivation conditions and the timing of microalgal harvest to maximize the lipid yield for biofuel production. The findings can also be implemented to explore the production of food and antibiotics from other microalgal metabolites with low energy costs. 相似文献
74.
Daniel C. B. Jeffery Brandon A. Wyse Muhammad Attiq Rehman Geoffrey W. Brown Zhiying You Roxanne Oshidari Hisao Masai Krassimir Y. Yankulov 《Nucleic acids research》2013,41(18):8475-8488
Position-effect variegation (PEV) phenotypes are characterized by the robust multigenerational repression of a gene located at a certain locus (often called gene silencing) and occasional conversions to fully active state. Consequently, the active state then persists with occasional conversions to the repressed state. These effects are mediated by the establishment and maintenance of heterochromatin or euchromatin structures, respectively. In this study, we have addressed an important but often neglected aspect of PEV: the frequency of conversions at such loci. We have developed a model and have projected various PEV scenarios based on various rates of conversions. We have also enhanced two existing assays for gene silencing in Saccharomyces cerevisiae to measure the rate of switches from repressed to active state and vice versa. We tested the validity of our methodology in Δsir1 cells and in several mutants with defects in gene silencing. The assays have revealed that the histone chaperone Chromatin Assembly Factor I is involved in the control of epigenetic conversions. Together, our model and assays provide a comprehensive methodology for further investigation of epigenetic stability and position effects. 相似文献
75.
Xiao‐Peng Zhang Tao Wu Jian Liu Jin‐Cheng Zhao Cheng‐Hui Li Xiao‐Zeng You 《Chirality》2013,25(7):384-392
Two couples of enantiomeric platinum(II) complexes: Pt(L1a)Cl ( 1a ), Pt(L1b)Cl ( 1b ) and Pt(L1a)(C ≡ C ? Ph) ( 2a ), Pt(L1b)(C ≡ C ? Ph) ( 2b ) (L1a = (+)‐1,3‐di‐(2‐(4,5‐pinene)pyridyl)benzene, L1b = (?)‐1,3‐di‐(2‐(4,5‐pinene)pyridyl)benzene) were synthesized and characterized. Their absolute configurations were determined by single crystal X‐ray diffraction and further verified by circular dichroism (CD) spectra (including electronic circular dichroism [ECD] and vibrational circular dichroism [VCD]). These complexes show interesting mechanoluminescence and/or vapoluminescence due to crystalline‐to‐amorphous transformation. The crystalline solids, grinding‐induced amorphous powders, and vapor‐induced amorphous powders of complexes 2a and 2b were comparatively investigated by solid‐state ECD and VCD spectra. The transformation from crystalline solids to amorphous powders was accompanied by significant variances of the spectral feature in both ECD and VCD spectra. Chirality 25:384–392, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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Wen‐Yuan Xie Fen‐Yao Zhang Zheng‐Hai Chen Gen‐You Li Guo‐Hua Xia 《Nordic Journal of Botany》2013,31(4):414-418
Ostericum atropurpureum G. Y. Li, G. H. Xia & W. Y. Xie (Apiaceae, Apioideae) from Zhejiang, China, is described and illustrated. It is closely related to O. huadongense Z. H. Pan & X. H. Li and O. sieboldii (Miquel) Nakai, but differs in having leaves with 1.5–9.0 cm long petiole, linear bracteoles 6–12 mm long, 5–9 rays, 7–14‐flowered umbellules, dark purple petals, broadly winged dorsal and lateral fruit ribs, 1.0–1.5 mm broad, 3–6 vittae in each furrow and 4–8 on the commissure. 相似文献
78.
A novel technique for internal structure and elemental distribution analyses of granular sludge is presented. Sludge samples were freeze-dried and embedded in epoxy resin to form a module, which were then ground and polished to obtain sequential cross-sections. The cross-sections were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). SEM observations showed that one granule was formed having several cores with different inorganic minerals, rather than a single core. EDX results indicate that the main elements of the granules are O, Ca, Mg, and P. In addition, the distribution areas of calcium and magnesium in the granule do not coincide. 相似文献
79.
Jiao Li Jun Dong Zhen‐hui Zhang Dong‐Cheng Zhang Xiang‐Yu You Yun Zhong Min‐Sheng Chen Shi‐Ming Liu 《Journal of cellular physiology》2013,228(12):2324-2336
miRNAs have recently been shown to play a significant role in human aging. However, data demonstrating the effects of aging‐related miRNAs in human mesenchymal stem cells (hMSCs) are limited. We observed that hMSC differentiation decreased with aging. We also identified that miR‐10a expression was significantly decreased with age by comparing the miRNA expression of hMSCs derived from young and aged individuals. Therefore, we hypothesized that the downregulation of miR‐10a may be associated with the decreased differentiation capability of hMSCs from aged individuals. Lentiviral constructs were used to up‐ or downregulate miR‐10a in young and old hMSCs. Upregulation of miR‐10a resulted in increased differentiation to adipogenic, osteogenic, and chondrogenic lineages and in reduced cell senescence. Conversely, downregulation of miR‐10a resulted in decreased cell differentiation and increased cell senescence. A chimeric luciferase reporter system was generated, tagged with the full‐length 3′‐UTR region of KLF4 harboring the seed‐matched sequence with or without four nucleotide mutations. These constructs were cotransfected with the miR‐10a mimic into cells. The luciferase activity was significantly repressed by the miR‐10a mimic, proving the direct binding of miR‐10a to the 3′‐UTR of KLF4. Direct suppression of KLF4 in aged hMSCs increased cell differentiation and decreased cell senescence. In conclusion, miR‐10a restores the differentiation capability of aged hMSCs through repression of KLF4. Aging‐related miRNAs may have broad applications in the restoration of cell dysfunction caused by aging. J. Cell. Physiol. 228: 2324–2336, 2013. © The Authors. Published by Wiley Periodicals, Inc. 相似文献
80.