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361.
Szu‐I. Hsieh Stephan W. Gale Chi‐Te Lee Chuan‐Rong Yeh Chong‐Sheng Leou Ching‐Long Yeh 《Nordic Journal of Botany》2013,31(4):403-407
Nervilia brevilobata C. S. Leou, C. L. Yeh & S. W. Gale sp. nov. (Orchidaceae), discovered in Taiwan and Hainan, is described and illustrated. The new species belongs to the one‐flowered group in Nervilia, but is readily distinguished from other species in the genus by the saccate base of the lip, the truncate‐rounded lobes of the hypochile, and by the relatively short, oblong‐orbicular epichile. 相似文献
362.
Te Liu Jiajia Lin Chuan Chen Xiaoli Nie Fangfang Dou Jiulin Chen Zhenxin Wang Zhangbin Gong 《Cell proliferation》2021,54(1)
ObjectiveTo examine the role of high‐fat and high‐sugar (HFHS) diet‐induced oxidative stress, which is a risk factor for various diseases, in premature ovarian failure (POF).Materials and methodsOvarian granulosa cells (OGCs) were isolated from mice and cultured in medium supplemented with HFHS and poly (lactic‐co‐glycolic acid) (PLGA)‐cross‐linked miR‐146b‐5p nanoparticles (miR‐146@PLGA). RNA and protein expression levels were examined using quantitative real‐time polymerase chain reaction and Western blotting, respectively. HFHS diet‐induced POF model mice were administered miR‐146@PLGA.ResultsThe ovarian tissue of mice fed a HFHS diet exhibited the typical pathological characteristics of POF. HFHS supplementation induced oxidative stress injury in the mouse OGCs, activation of the Dab2ip/Ask1/p38‐Mapk signalling pathway and phosphorylation of γH2A.X in vitro and in vivo. The results of the luciferase reporter assay revealed that miR‐146 specifically downregulated p38‐Mapk14 expression. Meanwhile, co‐immunoprecipitation and Western blot analyses revealed that HFHS supplementation upregulated nuclear p38‐Mapk14 expression and consequently enhanced γH2A.X (Ser139) phosphorylation. The HFHS diet‐induced POF mouse model treated with miR‐146@PLGA exhibited downregulated p38‐Mapk14 expression in the OGCs, mitigated OGC ageing and alleviated the symptoms of POF.ConclusionsThis study demonstrated that HFHS supplementation activates the Dab2ip/Ask1/p38‐Mapk signalling pathway and promotes γH2A.X phosphorylation by inhibiting the expression of endogenous miR‐146b‐5p, which results in OGC ageing and POF development. 相似文献
363.
Nora M. Urquiza Silvia G. Manca María A. Moyano Raquel Arrieta Dellmans Luis Lezama Teófilo Rojo Luciana G. Naso Patricia A. M. Williams Evelina G. Ferrer 《Biometals》2010,23(2):255-264
Methimazole (MeimzH) is an anti-thyroid drug and the first choice for patients with Grave’s disease. Two new copper(II) complexes of this drug:
[Cu(MeimzH)2(NO3)2].0.5H2O and [Cu(MeimzH)2(H2O)2](NO3)2·H2O were synthesized and characterized by elemental analysis, dissolution behavior, thermogravimetric analysis and UV-vis, diffuse
reflectance, FTIR and EPR spectroscopies. As it is known that copper(II) cation can act as an inhibitor of alkaline phosphatase
(ALP), the inhibitory effect of methimazole and its copper(II) complexes on ALP activity has also been investigated. 相似文献
364.
Manganese oxide/carbon aerogel composite electrodes are prepared by a self‐limiting anodic‐electrochemical deposition of manganese oxide into a binder‐enriched carbon aerogel layer, drop‐cast on a graphite substrate, using 0.1 M Mn(CH3COO)2·4H2O as the electrolyte. Manganese oxide grows in the form of thin nanofibers along the backbone of the carbon aerogel, leaving adequate working space for the electrolyte and enabling a fuller extent of the utilization of the manganese oxide to make the composite an outstanding supercapacitor electrode material. The manganese oxide is determined to be Mn3O4 with the Raman spectroscopy and high‐resolution transmission electron microscopy. The rectangularity of the cyclic‐voltammogram loops of the composite electrode is excellent and remains that way for scan rates up to a very‐high value of 500 mV s?1, indicating extremely good redox reversibility and cycle efficiency. At a scan rate of 25 mV s?1, the specific capacitance, as measured in 0.5 M Na2SO4 for a potential window of 0.1–0.9 V vs. Ag/AgCl, reaches a maximum value of 503 F g?1 and experiences only a negligible decay of less than 1% at the 6000th cycle, implying an extraordinary cycling stability. The cycling efficiency is as high as 98% at a current density of 8 A g?1 cm?2, showing an almost‐ideal capacitive behavior. The power density reaches 48.5 kW kg?1 and the energy density 21.6 W h kg?1 at a scan rate of 500 mV s?1, well above the specifications of current state‐of‐the‐art supercapacitors. 相似文献
365.
Marshella Tania Huancheng Zhou Yi Gao Te Ba Guo‐Dong Sean Tan Sangho Kim Hwa Liang Leo 《Biotechnology progress》2013,29(4):1002-1012
A myriad of bioreactor configurations have been investigated as extracorporeal medical support systems for temporary replacement of vital organ functions. In recent years, studies have demonstrated that the rotating bioreactors have the potential to be utilized as bioartificial liver assist devices (BLADs) owing to their advantage of ease of scalability of cell‐culture volume. However, the fluid movement in the rotating chamber will expose the suspended cells to unwanted flow structures with abnormally high shear conditions that may result in poor cell stability and in turn lower the efficacy of the bioreactor system. In this study, we compared the hydrodynamic performance of our modified rotating bioreactor design with that of an existing rotating bioreactor design. Computational fluid dynamic analysis coupled with experimental results were employed in the optimization process for the development of the modified bioreactor design. Our simulation results showed that the modified bioreactor had lower fluid induced shear stresses and more uniform flow conditions within its rotating chamber than the conventional design. Experimental results revealed that the cells within the modified bioreactor also exhibited better cell‐carrier attachment, higher metabolic activity, and cell viability compared to those in the conventional design. In conclusion, this study was able to provide important insights into the flow physics within the rotating bioreactors, and help enhanced the hydrodynamic performance of an existing rotating bioreactor for BLAD applications. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1002–1012, 2013 相似文献
366.
Luciana G. Naso Evelina G. Ferrer Nataliya Butenko Isabel Cavaco Luis Lezama Teófilo Rojo Susana B. Etcheverry Patricia A. M. Williams 《Journal of biological inorganic chemistry》2011,16(4):653-668
A new complex of the oxovanadium(IV) cation with the flavolignan silibinin has been synthesized and characterized. Vanadium
compounds show interesting biological and pharmacological properties and some of them display antitumoral actions. Flavonoids
are part of a larger group of antioxidant compounds called polyphenols which may inhibit the proliferation and growth of cancer
cells. The antioxidant and antitumoral effects of silibinin and its oxovanadium(IV) complex were investigated. Silibinin acted
as a very strong antioxidant and its complexation with oxovanadium(IV) improved this behavior. Besides, the generation of
reactive oxygen species (ROS) by this compound was favored in tumoral (UMR106) cells and correlated with the deleterious behavior
in the proliferation of this cell line. Conversely, silibinin did not exert any effect on the proliferation of normal osteoblasts
(MC3T3E1). The cytotoxic action and ROS generation of the oxovanadium(IV) complex was more effective in tumoral cells. This
behavior was not consistent with cleaving DNA of plasmid DNA pA1 because no significant cleaving activity was observed in
both cases. These results suggest that the main deleterious mechanisms may take place through cytotoxic effects more than
genotoxic actions. A comparison with our own findings on the behavior of other flavonoids and their vanadyl(IV) complex has
also been performed. 相似文献
367.
Hsu‐Chun Wu Rong‐Chien Lin Hsin‐Yi Hung Chia‐Fen Yeh Jui‐Hua Chu Xiao‐Jun Yang Chiou‐Ju Yao Fa‐Sheng Zou Cheng‐Te Yao Shou‐Hsien Li Fu‐Min Lei 《Zoologica scripta》2011,40(5):468-478
Wu, H.‐C., Lin, R.‐C., Hung, H.‐Y., Yeh, C.‐F., Chu, J.‐H., Yang, X.‐J., Yao, C.‐J., Zou, F.‐S., Yao, C.‐T., Li, S.‐H. & Lei, F.‐M. (2011). Molecular and morphological evidences reveal a cryptic species in the Vinaceous Rosefinch Carpodacus vinaceus (Fringillidae; Aves). —Zoologica Scripta, 40, 468–478. The Vinaceous Rosefinch (Carpodacus vinaceus) is endemic in East Asia with two recognized subspecies –C. v. vinaceus, distributed along the eastern edge of the Tibetan Plateau and the Himalayas, and C. v. formosanus, restricted to Taiwan’s Central Mountain Range. As reflected in a controversial taxonomic history, this vastly disjunctive distribution pattern suggests that the subspecies, having been isolated from each other for a long time, might have diverged, challenging the current taxonomic treatment and calling for possible species delimitation. Sequences of two mitochondrial fragments (mtDNA) and two Z‐linked nuclear loci (zDNA) were used to reconstruct the intraspecific phylogeny of C. vinaceous. The mtDNA tree shows that the two subspecies of the vinaceous rosefinch form two exclusively monophyletic clades. All but one zDNA sequences from the nominate subspecies and C. v. formosanus also formed exclusively monophyletic clades (the exceptional zDNA sequence from C. v. vinaceous formed a weakly supported clade with two outgroup species). Moreover, by conducting quantitative comparisons of morphometric traits and male plumage coloration, we found that the two subspecies exhibit distinguishable morphological differences. All the evidence therefore suggests that C. v. formosanus is a cryptic species and that its taxonomic status should be restored to full species. Molecular dating suggests that the two sibling rosefinches split 1.7 ± 0.2 million years ago, providing a point estimate for the historical connectivity of biota between eastern Tibet‐Himalayas and montane Taiwan. 相似文献
368.
Gabriela Andrejeva Sharon Gowan Gigin Lin Anne-Christine LF Wong Te Fong Elham Shamsaei Harry G. Parkes 《Autophagy》2020,16(6):1044-1060
ABSTRACT
Macroautophagy/autophagy can enable cancer cells to withstand cellular stress and maintain bioenergetic homeostasis by sequestering cellular components into newly formed double-membrane vesicles destined for lysosomal degradation, potentially affecting the efficacy of anti-cancer treatments. Using 13C-labeled choline and 13C-magnetic resonance spectroscopy and western blotting, we show increased de novo choline phospholipid (ChoPL) production and activation of PCYT1A (phosphate cytidylyltransferase 1, choline, alpha), the rate-limiting enzyme of phosphatidylcholine (PtdCho) synthesis, during autophagy. We also discovered that the loss of PCYT1A activity results in compromised autophagosome formation and maintenance in autophagic cells. Direct tracing of ChoPLs with fluorescence and immunogold labeling imaging revealed the incorporation of newly synthesized ChoPLs into autophagosomal membranes, endoplasmic reticulum (ER) and mitochondria during anticancer drug-induced autophagy. Significant increase in the colocalization of fluorescence signals from the newly synthesized ChoPLs and mCherry-MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) was also found on autophagosomes accumulating in cells treated with autophagy-modulating compounds. Interestingly, cells undergoing active autophagy had an altered ChoPL profile, with longer and more unsaturated fatty acid/alcohol chains detected. Our data suggest that de novo synthesis may be required to increase autophagosomal ChoPL content and alter its composition, together with replacing phospholipids consumed from other organelles during autophagosome formation and turnover. This addiction to de novo ChoPL synthesis and the critical role of PCYT1A may lead to development of agents targeting autophagy-induced drug resistance. In addition, fluorescence imaging of choline phospholipids could provide a useful way to visualize autophagosomes in cells and tissues. 相似文献