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151.
本研究使用单因素方法考察了无花果(Ficus carica L.)果皮中花青素的最佳提取条件,并考察了7种参数对花青素提取率的影响。参数设置如下:溶剂性质(水,甲醇,乙醇和丙酮)、提取次数(1~3次)、固液比(1/50,1/100,1/150和1/200)、提取时间(60 min,120 min,180 min和240 min)、甲醇浓度(0,20%,40%,60%,80%和100%)、酸类型(盐酸,乙酸,柠檬酸和酒石酸)和酸浓度(0,1%,2%,5%和10%)。使用pH-示差法测量无花果果皮中单体花色素的含量。研究显示,无花果果皮中花青素的最佳提取条件为:溶剂为甲醇溶剂,提取次数为2次,固液比为1/100,提取时间为180 min,甲醇浓度为80%,酸类型为柠檬酸,柠檬酸浓度为5%。该最佳提取条件下的花青素的提取率达到最高(345.62 mg/100g DS)。 相似文献
152.
该研究探讨人尿源性干细胞(human urine-derived stem cells,hUSCs)及人脐带间充质干细胞(human umbilical cord mesenchymal stem cells,hUC-MSCs)的生物学性状差异。分离培养hUSCs及hUC-MSCs,显微镜下观察细胞形态,流式细胞术检测干细胞表面标记物,锥虫蓝拒染实验及克隆形成实验检测细胞增殖能力,划痕实验及Transwell迁移实验检测细胞迁移能力,碱性磷酸酶(alkaline phosphatase,ALP)染色、茜素红染色、油红O染色及阿利新蓝染色评估多向分化潜能。hUSCs为米粒状贴壁生长细胞,hUC-MSCs为长梭形贴壁细胞,呈旋涡状排列生长,两种细胞表型分析相似,均表达多种间充质干细胞标志物,但CD24在hUC-MSCs表达阳性,而CD105在hUSCs表达阳性。hUC-MSCs的增殖及迁移能力优于hUSCs,但后者的克隆形成能力更强。hUSCs及hUCMSCs都具有成骨、成脂、成软骨分化能力,hUC-MSCs的成骨能力强而hUSCs的成脂能力强。该研究成功分离培养出增殖能力强并具有多向分化潜能的hUSCs,该细胞与hUC-MSCs相比具有相似的生物学性状,可作为再生医学自体移植的理想种子细胞来源。 相似文献
153.
Duwen Zeng Chenxi Qiu Yu Shen Jin Hou Zailu Li Jixiang Zhang Shuai Liu Jianli Shang Wensheng Qin Lili Xu Xiaoming Bao 《Microbial biotechnology》2020,13(6):2008-2019
Saccharomyces cerevisiae is the preferred source of RNA derivatives, which are widely used as supplements for foods and pharmaceuticals. As the most abundant RNAs, the ribosomal RNAs (rRNAs) transcribed by RNA polymerase I (Pol I) have no 5′ caps, thus cannot be translated to proteins. To screen high-nucleic-acid content yeasts more efficiently, a cap-independent protein expression system mediated by Pol I has been designed and established to monitor the regulatory changes of rRNA synthesis by observing the variation in the reporter genes expression. The elements including Pol I-recognized rDNA promoter, the internal ribosome entry site from cricket paralytic virus which can recruit ribosomes internally, reporter genes (URA3 and yEGFP3), oligo-dT and an rDNA terminator were ligated to a yeast episomal plasmid. This system based on the URA3 gene worked well by observing the growth phenotype and did not require the disruption of cap-dependent initiation factors. The fluorescence intensity of strains expressing the yEGFP3 gene increased and drifted after mutagenesis. Combined with flow cytometry, cells with higher GFP level were sorted out. A strain showed 58% improvement in RNA content and exhibited no sequence alteration in the whole expression cassette introduced. This study provides a novel strategy for breeding high-nucleic-acid content yeasts. 相似文献
154.
Jeongmin Yun Sujong Jeong Chang‐Hoi Ho Hoonyoung Park Junjie Liu Haeyoung Lee Stephen Sitch Pierre Friedlingstein Sebastian Lienert Danica Lombardozzi Vanessa Haverd Atual Jain Snke Zaehle Etsushi Kato Hanqin Tian Nicolas Vuichard Andy Wiltshire Ning Zeng 《Global Change Biology》2020,26(6):3368-3383
Understanding changes in terrestrial carbon balance is important to improve our knowledge of the regional carbon cycle and climate change. However, evaluating regional changes in the terrestrial carbon balance is challenging due to the lack of surface flux measurements. This study reveals that the terrestrial carbon uptake over the Republic of Korea has been enhanced from 1999 to 2017 by analyzing long‐term atmospheric CO2 concentration measurements at the Anmyeondo Station (36.53°N, 126.32°E) located in the western coast. The influence of terrestrial carbon flux on atmospheric CO2 concentrations (ΔCO2) is estimated from the difference of CO2 concentrations that were influenced by the land sector (through easterly winds) and the Yellow Sea sector (through westerly winds). We find a significant trend in ΔCO2 of ?4.75 ppm per decade (p < .05) during the vegetation growing season (May through October), suggesting that the regional terrestrial carbon uptake has increased relative to the surrounding ocean areas. Combined analysis with satellite measured normalized difference vegetation index and gross primary production shows that the enhanced carbon uptake is associated with significant nationwide increases in vegetation and its production. Process‐based terrestrial model and inverse model simulations estimate that regional terrestrial carbon uptake increases by up to 18.9 and 8.0 Tg C for the study period, accounting for 13.4% and 5.7% of the average annual domestic carbon emissions, respectively. Atmospheric chemical transport model simulations indicate that the enhanced terrestrial carbon sink is the primary reason for the observed ΔCO2 trend rather than anthropogenic emissions and atmospheric circulation changes. Our results highlight the fact that atmospheric CO2 measurements could open up the possibility of detecting regional changes in the terrestrial carbon cycle even where anthropogenic emissions are not negligible. 相似文献
155.
Emmanuelle Frchette Christine Yao‐Yun Chang Ingo Ensminger 《Global Change Biology》2020,26(9):5217-5234
In higher‐latitude trees, temperature and photoperiod control the beginning and end of the photosynthetically active season. Elevated temperature (ET) has advanced spring warming and delayed autumn cooling while photoperiod remains unchanged. We assessed the effects of warming on the length of the photosynthetically active season of three provenances of Pinus strobus L. seedlings from different latitudes, and evaluated the accuracy of the photochemical reflectance index (PRI) and the chlorophyll/carotenoid index (CCI) for tracking the predicted variation in spring and autumn phenology of photosynthesis among provenances. Seedlings from northern, local and southern P. strobus provenances were planted in a temperature‐free‐air‐controlled enhancement (T‐FACE) experiment and exposed to ET (+1.5/3°C; day/night). Over 18 months, we assessed photosynthetic phenology by measuring chlorophyll fluorescence, gas exchange, leaf spectral reflectance and pigment content. During autumn, all seedlings regardless of provenance followed the same sequence of phenological events with the initial downregulation of photosynthesis, followed by the modulation of non‐photochemical quenching and associated adjustments of zeaxanthin pool sizes. However, the timing of autumn downregulation differed between provenances, with delayed onset in the southern provenance (SP) and earlier onset in the northern relative to the local provenance, indicating that photoperiod at the provenance origin is a dominant factor controlling autumn phenology. Experimental warming further delayed the downregulation of photosynthesis during autumn in the SP. A provenance effect during spring was also observed but was generally not significant. The vegetation indices PRI and CCI were both effective at tracking the seasonal variations of energy partitioning in needles and the differences of carotenoid pigments indicative of the stress status of needles. These results demonstrate that PRI and CCI can be useful tools for monitoring conifer phenology and for the remote monitoring of the length of the photosynthetically active season of conifers in a changing climate. 相似文献
156.
Zhao Xue Bao Dongfang Wang Wei Zhang Chanjuan Jing Yan Jiang Haipeng Qiu Lijuan Li Wenbin Han Yingpeng 《Molecular breeding : new strategies in plant improvement》2020,40(10):1-12
Molecular Breeding - Northern corn leaf blight (NCLB) is one of the main diseases of maize, which greatly reduces production and causes millions of dollars in losses worldwide annually.... 相似文献
157.
Huifang M. Zhang Ye Qiu Guangze Zhao Hua Wang Yankuan T. Chen Sana Aghakeshmiri Paul Hanson Decheng Yang 《Cellular microbiology》2020,22(7)
Our previous study of coxsackievirus B3 (CVB3)‐induced unfolded protein responses (UPR) found that overexpression of ATF6a enhances CVB3 VP1 capsid protein production and increases viral particle formation. These findings implicate that ATF6a signalling benefits CVB3 replication. However, the mechanism by which ATF6a signalling is transduced to promote virus replication is unclear. In this study, using a Tet‐On inducible ATF6a HeLa cell line, we found that ATF6a signalling downregulated the protein expression of the endoplasmic reticulum (ER) degradation‐enhancing α‐mannosidase‐like protein 1 (EDEM1), resulting in accumulation of CVB3 VP1 protein; in contrast, expression of a dominant negative ATF6a had the opposite effect. Furthermore, we found that EDEM1 was cleaved by both CVB3 protease 3C and virus‐activated caspase and subsequently degraded via the ubiquitin‐proteasome pathway. However, overexpression of EDEM1 caused VP1 degradation, likely via a glycosylation‐independent and ubiquitin‐lysosome pathway. Finally, we demonstrated that CRISPR/Cas9‐mediated knockout of EDEM1 increased VP1 accumulation and thus CVB3 replication. This is the first study to report the ER protein quality control of non‐enveloped RNA virus and reveals a novel mechanism by which CVB3 evades host ER quality control pathways through cleavage and degradation of the UPR target gene EDEM1, to ultimately benefit its own replication. 相似文献
158.
Yingfan Cai Xiaoyan Cai Qinglian Wang Ping Wang Yu Zhang Chaowei Cai Yanchao Xu Kunbo Wang Zhongli Zhou Chenxiao Wang Shuaipeng Geng Bo Li Qi Dong Yuqing Hou Heng Wang Peng Ai Zhen Liu Feifei Yi Minshan Sun Guoyong An Jieru Cheng Yuanyuan Zhang Qian Shi Yuanhui Xie Xinying Shi Ying Chang Feifei Huang Yun Chen Shimiao Hong Lingyu Mi Quan Sun Lin Zhang Baoliang Zhou Renhai Peng Xiao Zhang Fang Liu 《Plant biotechnology journal》2020,18(3):814-828
159.
160.
The Fruit Dropping Characters of Sweet Cherry and Its Interior Causes in Insufficient Chilling Zone 总被引:1,自引:0,他引:1
Guo K. B. Qiao G. Qiu Z. L. Wen Z. Yang H. Wen X. P. 《Russian Journal of Plant Physiology》2020,67(1):94-102
Russian Journal of Plant Physiology - Attempts had been made to provide evidences insight into the pattern and physiological mechanism of sweet cherry fruit dropping. However, the fruit abscission... 相似文献