摘要：
Yellow tea is a lightly fermented tea with unique sensory qualities and health benefits. However, chemical composition and sensory quality of yellow tea products have rarely been studied. 12 representative yellow teas, which were basically covered the main products of yellow tea, were chosen in this study. Combined analysis of non-targeted/targeted metabolomics and electronic sensor technologies (E-eye, E-nose, E-tongue) revealed the chemical and sensor variation. The results showed that yellow big tea differed greatly from yellow bud teas and yellow little teas, but yellow bud teas could not be effectively distinguished from yellow little teas based on chemical constituents and electronic sensory characteristics. Sensor variation of yellow teas might be attributed to some compounds related to bitterness and aftertaste-bitterness (4 '-dehydroxylated gallocatechin-3-O-gallate, dehydrotheasinensin C, myricitin 3-O-galactoside, phloroglucinol), aftertaste-astringency (methyl gallate, 1,5-digalloylglucose, 2,6-digalloylglucose), and sweetness (maltotriose). This study provided a comprehensive un-derstanding of yellow tea on chemical composition and sensory quality.
摘要：
Phytohormones play a key role in regulating tiller number. Ascorbic acid (Asc)-phytohormone interaction plays a pivotal role in regulation of senescence. In this paper, the relationship between Asc and the enzyme concentrations and gene transcript abundances related to the signal perception of strigolactones (SLs), contents of four phytohormones i.e. abscisic acid (ABA), jasmonic acid (JA), indole acetic acid (IAA) and cytokinin (CTK), the enzyme concentrations and gene transcript abundances related to the synthesis or transportation of these four phytohormones were analyzed. The results showed that the Asc deficiency leads to the upregulation of enzyme concentrations and gene transcript abundances related to the SL signal perception, ABA synthesis and IAA transport. Meanwhile, the altered level of Asc also leads to a change in the contents of ABA, JA, IAA and CTK. These observations support the conclusion that Asc or Asc/DHA may play an important role in the signal perception and transduction of SLs, and Asc may affect the coordinated regulation of SL, IAA, and CTK on rice tillering.
摘要：
An important feature to be determined in mechanistic studies on chemiluminescence (CL) is its quantum efficiency, which can give significant chemical reaction information on the influence of the reactant structures and reaction conditions. However, most of the previous quantitative measurements of luminescence and quantum efficiencies are complex and incomplete. To overcome the inconvenience and underestimated quantum efficiency in each measurement, we report a simple and highly effective strategy to determine the absolute CL quantum efficiencies for three systems of luminol with hydrogen peroxide by means of a spectrometer along with an integrating sphere. The integrating sphere facilitated collection of all the emitted light and then transferred it to the spectrometer via an optical fiber proportionally. The CL quantum efficiency was determined by taking the ratio of total photons generated in the reaction system to the number of the limiting reactant molecules consumed. Absolute CL efficiencies of three luminol-H(2)O(2) reaction systems with varied reactant concentrations or coreactants were found to be 37%, 7.0% and 6.6% in a time course, which are much higher than those previously reported values of 1.0-1.3%. Due to our complete photon collection design, a higher absolute CL efficiency can be realized. Furthermore, spooling CL spectra also provided a powerful visualization tool to observe the real-time CL evolution and devolution, allowing the study on kinetics of CL reaction systems. The above investigations are anticipated to promote further development of CL methodologies and their applications.
期刊：
Journal of Hazardous Materials,2024年466:133442 ISSN：0304-3894
通讯作者：
Wu, Zhibin;Leng, Lijian;Qin, PF
作者机构：
[Shen, Tian; Qin, Pufeng; Liang, Yunshan; Wu, Zhibin] Hunan Agr Univ, Coll Environm & Ecol, Changsha 410128, Hunan, Peoples R China.;[Wu, Zhibin; Qin, Pufeng; Peng, Haoyi; Leng, Lijian; Qin, PF] Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Peoples R China.;[Yuan, Xingzhong; Leng, Lijian] Xiangjiang Lab, Changsha 410205, Peoples R China.;[Yuan, Xingzhong] Hunan Univ, Coll Environm Sci & Engn, Changsha 410082, Peoples R China.;[Liu, Shengqiang] Aerosp Kaitian Environm Technol Co Ltd, Changsha 410100, Peoples R China.
通讯机构：
[Wu, ZB; Leng, LJ; Qin, PF ] C;Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Cation exchange capacity;Gradient boosting regression;Heavy metal adsorption;Machine learning;Pyrogenic biochar
摘要：
Due to the broad interest in using biochar from biomass pyrolysis for the adsorption of heavy metals (HMs) in wastewater, machine learning (ML) has recently been adopted by many researchers to predict the adsorption capacity (η) of HMs on biochar. However, previous studies focused mainly on developing different ML algorithms to increase predictive performance, and no study shed light on engineering features to enhance predictive performance and improve model interpretability and generalizability. Here, based on a dataset widely used in previous ML studies, features of biochar were engineered-elemental compositions of biochar were calculated on mole basis-to improve predictive performance, achieving test R(2) of 0.997 for the gradient boosting regression (GBR) model. The elemental ratio feature (H-O-2N)/C, representing the H site links to C (non-active site to HMs), was proposed for the first time to help interpret the GBR model. The (H-O-2N)/C and pH of biochar played essential roles in replacing cation exchange capacity (CEC) for predicting η. Moreover, expanding the coverages of variables by adding cases from references improved the generalizability of the model, and further validation using cases without CEC and specific surface area (R(2) 0.78) and adsorption experimental results (R(2) 0.72) proved the ML model desirable. Future studies in this area may take into account algorithm innovation, better description of variables, and higher coverage of variables to further increase the model's generalizability.
摘要：
Addressing the problems of high seed-breaking ratio and difficult seed-shell separation in the current mechanical deshelling of Camellia Oleifera fruit (COF), this work innovatively proposed a strategy of low-temperature airflow-drying cracking coupling with flexible mechanical deshelling. The cracking ratio of COF reached 100% after airflow-drying at 20-50 degrees C for 4-10 h. Moreover, the tissue structure of the Camellia shell remained unchanged after airflow drying. The mechanical shelling ratio of cracked fruits (cracking gap 6 mm) reached 98.37%, and the shells present as integrated lamelliform for facilitating later sorting. The results of low-field nuclear magnetic resonance (LF-NMR) and shrinkage equation showed that the free water of outer layers in the Camellia shell evaporated first, then the free water of inner layers transferred to outer layers to further evaporate, creating a moisture gradient and moisture stress to cause the shrinkage of shell and cracking of COF.
作者：
Li, Ting;Zong, Guanyang;Peng, Pan;Wang, Shiqiang;Cheng, Bin
期刊：
Frontiers in Public Health,2024年11:1304279 ISSN：2296-2565
通讯作者：
Cheng, B;Wang, SQ
作者机构：
[Cheng, Bin; Cheng, B; Li, Ting] Shandong Univ, Sch Phys Educ, Jinan, Peoples R China.;[Zong, Guanyang] Dazhuang Primary Sch, Zoucheng, Peoples R China.;[Peng, Pan] Ezhou High Sch, Sch Informat Engn, Ezhou, Hubei, Peoples R China.;[Wang, Shiqiang] Hunan Univ Technol, Coll Phys Educ, Zhuzhou, Peoples R China.;[Wang, Shiqiang] Hunan Normal Univ, Hunan Prov Key Lab Phys Fitness & Sports Rehabil, Changsha, Peoples R China.
通讯机构：
[Cheng, B ] S;[Wang, SQ ] H;Shandong Univ, Sch Phys Educ, Jinan, Peoples R China.;Hunan Univ Technol, Coll Phys Educ, Zhuzhou, Peoples R China.;Hunan Normal Univ, Hunan Prov Key Lab Phys Fitness & Sports Rehabil, Changsha, Peoples R China.
关键词：
bouted PA;community-dwelling older Chinese women;frailty;frailty subdomain;sporadic PA
摘要：
BACKGROUND: The relationship between the patterns of physical activity (PA) and frailty, including its various subdomains, remains poorly understood. Therefore, this study aims to investigate the correlations between the patterns of physical activity and frailty and its various subdomains in community-dwelling older women. METHODS: A cross-sectional study investigated the association between physical activity and frailty in 1,099 women aged between 60 to 70 years. Triaxial accelerometers were used to measure bouted PA (a minimum duration of 10 min) and sporadic PA (a duration of <10 min). Fried's frailty phenotype was utilized to evaluate the status of frailty. Data were analyzed using logistic regression and the receiver operating characteristic (ROC) curve. RESULTS: Bouted moderate-to-vigorous PA (MVPA) and sporadic MVPA were associated with decreased odds of being prefrail and frail, and the optimal cutoff values were 6 and 19.7 for the prefrail stage and 6.6 and 19.4 min/day for the frail stage, respectively. Bouted light PA (LPA) was associated with decreased odds of being prefrail, and the optimal cutoff value was 170.2 min/day. Additionally, bouted and sporadic MVPA were associated with decreased odds of being slow and their optimal cutoff values were 5 and 19.1 min/day, respectively. Sporadic MVPA was associated with decreased odds of exhaustion, and the cutoff was 19.7 min/day. Bouted MVPA and LPA were associated with decreased odds of having low PA, and the cutoff values were 4.4 and 163.2 min/day, respectively. CONCLUSION: Any MVPA, regardless of bout duration, could be used as a suitable PA program to improve and prevent frailty in older women, such as bouted MVPA (4-5 times/week) or sporadic MVPA (20 min/day). The improvement effect of bouted and sporadic MVPA on the frailty of older people may not be affected by the subdomain. Additionally, bouted LPA was suitable for the management of prefrailty.
通讯机构：
[Zou, J; Wang, HQ; Xiao, TY ] H;Hunan Agr Univ, Hunan Engn Technol Res Ctr Featured Aquat Resource, Changsha 410128, Peoples R China.
关键词：
Fish;Virus resistance;Pattern recognition receptor;Genetic structure;Nucleic acid fragment
摘要：
Disease resistance varies among fish species. The genetic factors contributing to disease resistance are largely unknown. Here, by comparative analysis on the disease resistance trait of grass carp (Ctenopharyngodon idellus, Ci) and barbel chub (Squaliobarbus curriculus, Sc), we report that the genes encoding SIDT2, MDA5 and IFN are associated with the resistance to viral infection. We identified the amino acid difference of SIDT2s, the existing or lacking of dsRNA binding loci in the carboxy-terminal domain (CTD) of MDA5s, and the promoter difference of ifn2s between the two fish species. Both CiSIDT2 and ScSIDT2 negatively regulate the MDA5-IRF3/7 mediated type I IFN reaction, and ScSIDT2 exhibited a stronger ability than CiSIDT2 to induce Ciirf7, Ciifn1, Ciifn2 and Cimx expressions, and to resist GCRV infection. ScMDA5 showed a greater ability than CiMDA5 in the induction of IRF7-mediated type I interferon and anti-GCRV function. CiMDA5 CTD inhibited Ciifn1 while enhanced Ciifn2 exrpessions, and ScMDA5 CTD exerts opposite effects on Ciifn1 and Ciifn2 expressions. ScMDA5 CTD possesses the ability to bind with GCRV nucleic acid fragments, while CiMDA5 lacking binding with virus genome. The promoter activities of Ciifn2 is significantly higher than that of Scifn2 owning to their differences in promoter sequences and binding proteins. These data revealed the mechanism of SIDT2-MDA5-IFN genetic architecture contributing to the difference in interspecies resistance and opening the possibility of molecular breeding for fish resistance.
摘要：
BACKGROUND: Heat stress (HS) damages the intestines, disrupting gut microbiota and immune balance. L-Theanine (LTA), found in tea, alleviates oxidative stress and cell apoptosis under HS; however, its effects on gut microbiota and immunity under HS remain unclear. To investigate this, we administered LTA doses of 100, 200, and 400 mg center dot kg(-1)center dot d(-1) to C57BL/6J mice. On day 44, the model group and LTA intervention group were subjected to continuous 7-day HS treatment for 2 h per day. RESULTS: The results demonstrated that LTA intervention improved food intake, body weight, and intestinal epithelium, and reduced the water intake of heat-stressed mice. It increased the abundance of Turicibacter, Faecalibaculum, Bifidobacterium, and norank_f_Muribaculaceae, while reducing that of Lachnoclostridium and Desulfovibrio. LTA intervention also increased the concentrations of amino acid and lipid metabolites, regulated macrophage differentiation stimulated by gut microbiota and metabolites, reduced the antigen presentation by macrophages to the specific immune system, promoted B-cell differentiation and sIgA secretion, inhibited pro-inflammatory factors, and enhanced intestinal defense. Mechanistically, LTA downregulated heat shock protein 70 expression and the TLR4/NF-kappa B/p38 MAPK signaling pathway, restoring gut microbiota and immune balance. CONCLUSION: We suggest that LTA can alleviate HS by modulating gut microbiota, metabolites, and immunity, indicating its potential as a natural active ingredient for anti-HS food products. (c) 2023 Society of Chemical Industry.
摘要：
Type 2 diabetes mellitus (T2DM) is a chronic and complex disease, and traditional drugs have many side effects. The active compound dihydromyricetin (DHM), derived from natural plants, has been shown in our previous study to possess the potential for reducing blood glucose levels; however, its precise molecular mechanism remains unclear. In the present study, network pharmacology and transcriptomics were performed to screen the molecular targets and signaling pathways of DHM disturbed associated with T2DM, and the results were partially verified by molecular docking, RT-PCR, and Western blotting at in vivo levels. Firstly, the effect of DHM on blood glucose, lipid profile, and liver oxidative stress in db/db mice was explored and the results showed that DHM could reduce blood glucose and improve oxidative stress in the liver. Secondly, GO analysis based on network pharmacology and transcriptomics results showed that DHM mainly played a significant role in anti-inflammatory, antioxidant, and fatty acid metabolism in biological processes, on lipoprotein and respiratory chain on cell components, and on redox-related enzyme activity, iron ion binding, and glutathione transferase on molecular functional processes. KEGG system analysis results showed that the PI3K-Akt signaling pathway, IL17 signaling pathway, HIF signaling pathway, MAPK signaling pathway, AGE-RAGE signaling pathway in diabetic complications, and TNF signaling pathway were typical signaling pathways disturbed by DHM in T2DM. Thirdly, molecular docking results showed that VEGFA, SRC, HIF1A, ESR1, KDR, MMP9, PPARG, and MAPK14 are key target genes, five genes of which were verified by RT-PCR in a dose-dependent manner. Finally, Western blotting results revealed that DHM effectively upregulated the expression of AKT protein and downregulated the expression of MEK protein in the liver of db/db mice. Therefore, our study found that DHM played a therapeutic effect partially by activation of the PI3K/AKT/MAPK signaling pathway. This study establishes the foundation for DHM as a novel therapeutic agent for T2DM. Additionally, it presents a fresh approach to utilizing natural plant extracts for chemoprevention and treatment of T2DM.
通讯机构：
[Shen, QW; Quan, W ] H;Henan Univ Anim Husb & Econ, Sch Food Sci & Bioengn, 6 Longzihu North Rd, Zhengzhou 450046, Peoples R China.;Hunan Agr Univ, Coll Food Sci & Technol, Changsha 410128, Peoples R China.
关键词：
western dietary patterns;behavioral health disorders;red meat;refined grain;depression
摘要：
Western dietary patterns (WDP) and typical food groups may play a major role in the risk of behavioral health disorders. Nevertheless, the relationships between WDP, common food categories, and mental health disorders lack consistency and remain incompletely understood in relation to potential mechanisms. Therefore, the objective of the present study was conducted to synthesize available evidence linking WDP and typical food groups to these outcomes. Web of Science, PubMed, EMBASE, and MEDLINE were searched up to August 2023. Random effect meta-analyses were performed to obtain pooled odds ratio and the relative risk for the prevalence of outcomes and the incidence of outcomes, respectively. A total of 54 articles were included. WDP was associated with increased risk of both depression (1.19; 95% CI: 1.06-1.32) and depressive symptoms (1.20; 95% CI: 1.08-1.34). Except for high-fat dairy products, food groups are associated with an increased risk of anxiety, depression, and depressive symptoms. This review presents evidence to further understand the relationship between WDP, typical food groups, and the incidence of behavioral health disorders, and more randomized controlled trials and cohort studies are urgently required to confirm these findings and elucidate potential mechanisms.
摘要：
Evidence showed that N6-methyladenosine (m6A) modification plays a pivotal role in influencing RNA fate and is strongly associated with cell growth and developmental processes in many species. However, no information regarding m6A modification in Eimeria tenella is currently available. In the present study, we surveyed the transcriptome-wide prevalence of m6A in sporulated oocysts and unsporulated oocysts of E. tenella. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) analysis showed that m6A modification was most abundant in the coding sequences, followed by stop codon. There were 3,903 hypermethylated and 3,178 hypomethylated mRNAs in sporulated oocysts compared with unsporulated oocysts. Further joint analysis suggested that m6A modification of the majority of genes was positively correlated with mRNA expression. The mRNA relative expression and m6A level of the selected genes were confirmed by quantitative reverse transcription PCR (RT-qPCR) and MeRIP-qPCR. GO and KEGG analysis indicated that differentially m6A methylated genes (DMMGs) with significant differences in mRNA expression were closely related to processes such as regulation of gene expression, epigenetic, microtubule, autophagy-other and TOR signaling. Moreover, a total of 96 DMMGs without significant differences in mRNA expression showed significant differences at protein level. GO and pathway enrichment analysis of the 96 genes showed that RNA methylation may be involved in cell biosynthesis and metabolism of E. tenella. We firstly present a map of RNA m6A modification in E. tenella, which provides significant insights into developmental biology of E. tenella.
作者机构：
[Sun, Xiaowu; Chen, Zhongquan; Song, Huijuan; Jiang, Hong; Yang, Hongbo; Yan, Jiali; Dai, Sihui] Hunan Agr Univ, Coll Hort, Key Lab Vegetable Biol Hunan Prov, Engn Res Ctr Germplasm Innovat & New Varieties Bre, Changsha 410128, Peoples R China.;[Yang, Hongbo] Shaoyang Acad Agr Sci, Shaoyang 422000, Peoples R China.;[Sun, Longjun] Hunan Xuefeng Seed Ind Co Ltd, Shaoyang 422001, Peoples R China.
通讯机构：
[Sun, XW ] H;Hunan Agr Univ, Coll Hort, Key Lab Vegetable Biol Hunan Prov, Engn Res Ctr Germplasm Innovat & New Varieties Bre, Changsha 410128, Peoples R China.
关键词：
de novo organogenesis;regeneration system;histological analysis;winter squash
摘要：
Improving plant regeneration ability and shortening regeneration time can promote the development of genetic transformation breeding technology for horticultural crops. We optimized several culture conditions, including explant type, mother plant genotype, and medium, to improve shoot formation in winter squash (Cucurbita maxima Duch.). Histological analysis of the occurrence of shoots was also carried out. The results indicate that cotyledon was the most suitable explant for inducing the shoot regeneration of winter squash. We found that 'Jin-li' had a shorter shoot induction time and a higher average number of shoots. The highest induction rate of 95.23% among the five lines. The average shoot induction rate of five lines was the highest (84.85%) on Murashige and Skoog (MS) medium supplemented with 2.0 mg/L 6-benzylaminopurine (6-BA) and 0.2 mg/L indole-3-acetic acid (IAA). We also found that there was an interaction between genotypes and induction media, and their interaction had a greater impact on the shoot induction rate than individual effects. Histological observation revealed that the induced shoots of winter squash cotyledons originated from subepidermal cells. We also found that the optimal medium for de novo root regeneration was 1/2 MS. We acclimatized and cultivated regenerated plants and harvested their fruits, which maintained the characteristics of mother plants. These findings lay an important foundation for further research on direct shoot regeneration and accelerate its application in winter squash genetic transformation.
关键词：
Intercropping;Soil C pool;Carbon use efficiency;Microbial growth;Microbial diversity;Core microbiota
摘要：
Intercropping is a powerful practice to alter the allocation of photosynthetic carbon (C) to belowground ecosystems via promotion of diversified plant communities. The feedback of soil C stability to intercropping is controlled by microbial C use efficiency (CUE). Despite its significance, there is currently insufficient evidence to decipher how soil microbial CUE reacts to intercropping. By combining a 10-year-long intercropping experiment with a substrate-independent 18O-H2O labelling approach and high-throughput sequencing, we elucidated the performance of intercropping on soil C pool and microbial metabolic traits as well as their relationships with soil microbial communities. Compared with monoculture, maize intercropping with peanut and soybean significantly increased soil C storage, soil mineral-associated organic C (MAOC), soil dissolved organic (DOC), and soil microbial biomass (MBC) contents at maize four growth stages. Soil microbial CUE increased significantly, especially at maize flowering and mature stages, as a consequence of enhanced microbial growth and biomass turnover rate after maize intercropping with peanut and soybean. Soil C storage and accessibility indicators (e.g., MAOC, DOC, and MBC contents) could significantly predict the changes of soil microbial diversity and core taxa. Meanwhile, the beta-diversity (community composition) of soil bacteria, fungi, saprotroph and protists, as well as rare fungal taxa were positively correlated with soil microbial CUE, and these indicators showed a high prediction of the microbial CUE. Soil C storage and accessibility indicators directly and indirectly influenced soil microbial CUE by regulating microbial diversity and key taxa. Soil microbial diversity and core taxa directly and indirectly influenced microbial CUE by mediating microbial respiration, growth, biomass, and enzyme activity, which mediated by soil C storage and accessibility. These findings provide an evidence for the associations between microbial diversity, CUE, and soil C stability, highlighting the importance of intercropping-driven soil microbiome to enhance soil microbial CUE.
摘要：
Soil salinity seriously hinders the sustainable development of green agriculture. The emergence of engineered nanomaterials has revolutionized agricultural research, providing a new means to overcome the limitations associated with current abiotic stress management and achieve highly productive agriculture. Herein, we synthesized a brand-new engineered nanomaterial (Cs-Se NMs) through the Schiff base reaction of oxidized chitosan with selenocystamine hydrochloride to alleviate salt stress in plants. After the addition of 300 mg/L Cs-Se NMs, the activity of superoxide dismutase, catalase, and peroxidase in rice shoots increased to 3.19, 1.79, and 1.85 times those observed in the NaCl group, respectively. Meanwhile, the MDA levels decreased by 63.9%. Notably, Cs-Se NMs also raised the transcription of genes correlated with the oxidative stress response and MAPK signaling in the transcriptomic analysis. In addition, Cs-Se NMs augmented the abundance and variety of rhizobacteria and remodeled the microbial community structure. These results provide insights into applying engineered nanomaterials in sustainable agriculture.
期刊：
Cell Biochemistry and Biophysics,2024年:1-8 ISSN：1085-9195
通讯作者：
Ji, CX
作者机构：
[Wang, Dongliang; Pan, Yanying; Liu, Jianying; Ji, Chunxiao; Chen, Tao; Zhou, Pengfei; Ji, CX] Hunan Agr Univ, Coll Vet Med, Changsha 410128, Peoples R China.;[Wang, Dongliang; Pan, Yanying; Liu, Jianying; Ji, Chunxiao; Chen, Tao; Zhou, Pengfei; Ji, CX] Hunan Agr Univ, Hunan Engn Technol Res Ctr Vet Drugs, Changsha 410128, Peoples R China.;[Tang, Yulong] Chinese Acad Sci, Inst Subtrop Agr, Changsha 410125, Hunan, Peoples R China.
通讯机构：
[Ji, CX ] H;Hunan Agr Univ, Coll Vet Med, Changsha 410128, Peoples R China.;Hunan Agr Univ, Hunan Engn Technol Res Ctr Vet Drugs, Changsha 410128, Peoples R China.
关键词：
DADS;MDCC-MSB-1 cells;Autophagy;MEK;ERK
摘要：
Diallyl disulfide (DADS) is effective at suppressing tumour cell growth and proliferation. This study verified the morphology and growth activity of MDCC-MSB-1 cells by using an MTT assay to detect the effect of DADS on the proliferation of MDCC-MSB-1 cells and a CCK8 assay to detect the effect of DADS on the viability and proliferation of MDCC-MSB-1 cells. We found that the viability and proliferation of MDCC-MSB-1 cells decreased with increasing DADS concentrations. MDC staining and Western blotting were used to analyse autophagy, the associated protein LC3 and the MEK/ERK pathway proteins MEK and ERK and to investigate changes in cellular autophagy based on cell morphology and molecular biology. With increasing concentrations of DADS, MDCC-MSB-1 cell autophagy increased in a gradient manner. Additionally, the conversion of the autophagy marker protein LC3-I increased with increasing drug concentrations, and the relative expression of LC3-II steadily increased, as did the expression of key protein components of the MEK/ERK signalling pathway, including P-MEK1/2 and P-ERK1/2. These results suggest that DADS induces autophagy through the MEK/ERK pathway, thereby inhibiting the proliferation of MDCC-MSB-1 cells.
摘要：
Understanding how phytoplankton interacts with local and regional drivers as well as their feedbacks is a great challenge, and quantitative analyses of the regulating role of human activities and climate changes on these feedback loops are also limited. By using monthly monitoring dataset (2000-2017) from Lake Taihu and empirical dynamic modelling to construct causal networks, we quantified the strengths of causal feedbacks among phytoplankton, local environments, zooplankton, meteorology as well as global climate oscillation. Prevalent bidirectional causal linkages between phytoplankton biomass (chlorophyll a) and the tested drivers were found, providing holistic and quantitative evidence of the ubiquitous feedback loops. Phytoplankton biomass exhibited the highest feedbacks with total inorganic nitrogen and ammonia and the lowest with nitrate. The feedbacks between phytoplankton biomass and environmental factors from 2000 to 2017 could be classified into two groups: the local environments (e.g., nutrients, pH, transparency, zooplankton biomass)-driven enhancement loops promoting the response of the phytoplankton biomass, and the climate (e.g., wind speed)-driven regulatory loops suppressing it. The two counterbalanced groups modified the emergent macroecological patterns. Our findings revealed that the causal feedback networks loosened significantly after 2007 following nutrient loading reduction and unsuccessful biomanipulation restoration attempts by stocking carp. The strength of enhancement loops underwent marked decreases leading to reduced phytoplankton responses to the tested drivers, while the climate (decreasing wind speed, warming winter)-driven regulatory loops increased- like a tug-of-war. To counteract the self-amplifying feedback loops, the present eutrophication mitigation efforts, especially nutrient reduction, should be continued, and introduction of alternative measures to indirectly regulate the critical components (e.g., pH, Secchi depth, zooplankton biomass) of the loops would be beneficial.
摘要：
Single-atom nanozymes (SAzymes) have been wildly used to design high-performance biosensors for the quantification of organophosphorus pesticides (OPs) recently. However, the low yield and low metal loading of SAzymes often limit their practical use in biosensing field. Herein, a large-scale synthesis (6.60 g) of Fe-N /C SAzymes (Fe loading of 3.9 wt%) was achieved by using carbon black as a template. This prepared Fe-N/C SAzymes exhibit efficient oxidase-like activity that could catalyze the oxidation reaction of 3,3 ',5,5 '-tetramethylbenzidine (TMB) along with color variation. On this basis of Fe-N/C SAzymes, a colorimetric biosensor was designed for OPs detection. Then a smartphone combined with RGB analysis was used to digitize the color information. The B/ (R + G) value shows good linear detection range (1-100 nM) and low detection limit (0.4177 nM). More importantly, the large-scale synthetic approach and excellent catalytic performance of Fe-N/C SAzymes are significant for promoting the marketability of biosensors.
通讯机构：
[Yin, X ; Liu, ZH ] H;Hunan Agr Univ, Key Lab Tea Sci, Minist Educ, Changsha 410128, Peoples R China.;Natl Res Ctr Engn & Technol Utilizat Bot Funct Ing, Changsha 410128, Peoples R China.;Hunan Acad Agr Sci, Tea Res Inst, Dept Tea Qual Chem & Nutr Hlth, Hunan Tea Plant & Tea Proc Observat Stn,Minist Agr, Changsha 410125, Peoples R China.;Minist Utilizat Bot Funct Ingredients, Coinnovat Ctr Educ, Changsha 410128, Peoples R China.
关键词：
Shaken Hunan black tea;leaves grade;taste;aroma;HS-SPME/GC-MS
摘要：
Shaken Hunan black tea is an innovative Hunan black tea processed by adding shaking to the traditional Hunan black tea. The quality of shaken black tea is influenced by leaf grades of different maturity. In this study, the taste and aroma quality of shaken Hunan black tea processed with different grades were analyzed by sensory evaluation (SP, HPLC, and HS-SPME/GC-MS). The results showed that shaken Hunan black tea processed with one bud and two leaves has the best quality, which has a sweet, mellow, and slightly floral taste, as well as a floral, honey, and sweet aroma. Moreover, caffeine and EGCG were identified as the most important bitter and astringent substances in shaken Hunan black. Combined with the analysis of GC-MS and OAV analysis, geraniol, jasmone, beta-myrcene, citral, and trans-beta-ocimene might be the most important components that affect the sweet aroma, while methyl jasmonate, indole, and nerolidol were the key components that affect the floral aroma of shaken Hunan black tea. This study lays a foundation for this study of the taste and aroma characteristics of shaken Hunan black tea and guides enterprises to improve shaken black tea processing technology.
摘要：
In this study, the effects of grafting chlorogenic acid (CA) on the antioxidant and probiotic activities of curdlan oligosaccharides (CDOS) were investigated. CDOS with degrees of polymerization of 3-6 was first obtained by degradation of curdlan with hydrogen peroxide and then grafted with CA using a free radical-mediated method under an ultrasonication-assisted Fenton system. The thermal stability and antioxidant ability of CDOS were enhanced after grafting with CA. In vitro fermentation, supplementation of CDOS-CA stimulated the proliferation of Prevotella and Faecalibacterium while inhibiting the growth of harmful microbiota. Notably, the concentration of total short-chain fatty acids and the relative abundance of beneficial bacteria markedly increased after fermentation of CDOS-CA, indicating that CA grafting could improve the probiotic activity of CDOS. Overall, the covalent binding of CDOS and CA could enhance the antioxidant and probiotic activities of CDOS, suggesting potential improvements in gastrointestinal and colonic health.
