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By inducing steric activation of the 10CH bond with a 12-acyl group to form a key imine oxime intermediate, 20 novel (10S)-10,12-disubstituted aloperine derivatives were successfully synthesized and assessed for their antiviral efficacy against HCoV-OC43. Of them, compound 3i exhibited the moderate activities against HCoV-OC43, as well as against the SARS-CoV-2 variant EG.5.1 with the comparable EC50 values of 4.7 and 4.1 µM. A mechanism study revealed that it inhibited the protease activity of host TMPRSS2 by binding to an allosteric site, rather than the known catalytic center, different from that of camostat. Also, the combination of compound 3i and molnupiravir, as an RdRp inhibitor, showed an additive antiviral effect against HCoV-OC43. The results provide a new binding mode and lead compound for targeting TMPRSS2, with an advantage in combating broad-spectrum coronavirus.
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Sítio Alostérico , Antivirais , Coronavirus Humano OC43 , Quinolizidinas , Serina Endopeptidases , Antivirais/farmacologia , Antivirais/química , Antivirais/síntese química , Serina Endopeptidases/metabolismo , Humanos , Coronavirus Humano OC43/efeitos dos fármacos , Coronavirus Humano OC43/química , Quinolizidinas/química , Quinolizidinas/farmacologia , Quinolizidinas/síntese química , Sítio Alostérico/efeitos dos fármacos , Relação Estrutura-Atividade , Descoberta de Drogas , SARS-CoV-2/efeitos dos fármacos , Estrutura Molecular , Testes de Sensibilidade Microbiana , Relação Dose-Resposta a DrogaRESUMO
BACKGROUND: Although most children with febrile seizures (FS) have a favorable prognosis, some experience recurrence within 1-3 years. Age, peak temperature, and family history are now recognized as important risk factors for FS recurrence, yet studies in this area are lacking in China. This study aimed to investigate the risk factors for FS recurrence in children in Nantong, China, and to develop a prediction model. METHODS: This retrospective cohort study analyzed 463 children diagnosed with febrile seizures (FS) who presented to the Affiliated Hospital of Nantong University between January 2015 and June 2020. Basic information, disease characteristics, and laboratory and imaging data were collected. A follow-up survey was conducted one year post-discharge to assess the recurrence status of FS in children. Univariate logistic regression and random forest models were used to identify and rank the predictive ability of risk factors for recurrence. RESULTS: Of the 463 children with FS, 70 experienced recurrences within 1 year of discharge, resulting in a one-year recurrence rate of 15%. Age (OR = 0.61, 95% CI: 0.46, 0.80, P < 0.001), duration of the first episode (OR = 1.03, 95% CI: 1.00, 1.06, P = 0.040), and peak temperature (OR = 0.68, 95% CI: 0.47, 0.98, P = 0.036) were identified as independent risk factors for FS recurrence. Age had the highest relative importance in predicting FS recurrence, followed by the duration of the first episode, with an area under the ROC curve of 0.717. CONCLUSION: Young age and duration of the first seizure are important independent risk factors for FS recurrence and are key considerations for predicting recurrence. Further research is needed to confirm the potential use of Neutrophil-lymphocyte ratio (NLR) as a predictor of FS recurrence.
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Recidiva , Convulsões Febris , Humanos , Convulsões Febris/epidemiologia , Convulsões Febris/diagnóstico , Estudos Retrospectivos , Fatores de Risco , Masculino , Feminino , China/epidemiologia , Lactente , Pré-Escolar , Fatores Etários , Seguimentos , Criança , PrognósticoRESUMO
BACKGROUND: Lotus seedpods are an agricultural by-product of lotus (Nelumbo nucifera Gaertn.), which is widely cultivated in Southeast Asia and Australia. Most lotus seedpods are considered waste and are abandoned or incinerated, resulting in significant waste of resources and heavy environmental pollution. For recycling lotus seedpods, the extraction optimization, physicochemical properties, antioxidant activity, and α-glucosidase inhibitory effect of the polysaccharides contained therein were investigated in this study. RESULTS: Hot water extraction of lotus seedpod polysaccharides was optimized by using a response surface methodology combined with a Box-Behnken design, with the optimum conditions being as follows: a liquid/solid ratio of 25.0 mL g-1 , an extraction temperature of 98.0 °C, and an extraction time of 138.0 min. Under these conditions, an experimental yield of 5.88 ± 0.06% was obtained. Physicochemical analyses suggested that lotus seedpod polysaccharides belong to acidic heteropolysaccharides and are principally composed of rhamnose, arabinose, galactose, glucose, mannose, and galacturonic acid. The polysaccharides content has a broad molecular weight distribution (2.15 × 105 to 1.77 × 107 Da), an α-configuration, and mainly possesses smooth and sheet-like structures. Biological evaluations showed that the polysaccharides possessed good scavenging activity on 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, 1,1-diphenyl-2-picryl-hydrozyl, and hydroxyl radicals, and exerted an obvious inhibitory effect on α-glucosidase activity. Moreover, the polysaccharides content was determined to be a mixed-type noncompetitive inhibitor of α-glucosidase. CONCLUSION: The results indicate that lotus seedpod polysaccharides have potential as natural antioxidants and hypoglycaemic substitutes. This study provides the theoretical bases for the exploitation and application of polysaccharides from lotus seedpod by-product resources. © 2022 Society of Chemical Industry.
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Antioxidantes , Lotus , Antioxidantes/química , Antioxidantes/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Sementes , alfa-Glucosidases/químicaRESUMO
BACKGROUND: Membrane lipid composition associates closely with membrane stability and fluidity under water stress. In this study, lipidomic analyses based on electrospray ionization mass spectrometry (ESI-MS/MS) were carried out to explore dynamic changes of membrane lipids in term of molecular species caused by PEG (Polyethylene glycol-6000)-induced water stress in wheat seedlings. RESULTS: Among the main phospholipids, phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylglycerol (PG) are primary degradation targets, and PC was degraded in the largest degree. Membrane ion leakage dramatically increased later than the significant reduction of these phospholipids, indicating that the loss of membrane integrity lagged behind severe phospholipid degradation. Monogalactosyldiacylglycerol (MGDG) increased firstly and decreased later, while digalactosyldiacylglycerol (DGDG) ratcheted up with stress. DGDG/MGDG increased after stress for 3 days, and unsaturation of DGDG was promoted with stress. Variation trends of galactolipids differed among molecular species. The time when MGDG (34:3), DGDG (34:3) began to decline approached to the time when non-stomatal limitation impaired photosynthesis. While the two predominant molecular species MGDG (36:6) and DGDG (36:6) began to decline later. So we speculated that MGDG (34:3), DGDG (34:3) might be key components in photosynthesis apparatus and participate in photosynthesis directly. While the two predominant molecular species, MGDG (36:6) and DGDG (36:6) might locate in thylakoid lipid bilayer matrix and play roles in stabilizing the membrane. The research provides new insights into the dynamic response of lipid metabolism to PEG-induced water stress. CONCLUSION: In wheat plants under water stress, the major molecular species of PC, PE and PG were degraded, MGDG and DGDG molecular species had differing degradation time courses.
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Secas , Lipídeos de Membrana/metabolismo , Folhas de Planta/metabolismo , Triticum/fisiologia , Polietilenoglicóis/efeitos adversos , Plântula/metabolismo , Estresse Fisiológico/genéticaRESUMO
A coumarin-diaminomaleonitrile derivative (C-DAN) was designed and prepared. Upon addition of hypochlorite (OCl-), the fluorescence emission peak of C-DAN at 475 nm was gradually enhanced with a rapid response (within 5 s); meanwhile, the color of the solution changed from dark red to bright yellow which can be observed with the naked eye. Furthermore, owing to its advantages including high selectivity, sensitivity, and low toxicity, our C-DAN probe has been applied for detecting OCl- in living cells and zebrafish, indicating it is an ideal tool for biological applications.
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Cumarínicos/química , Corantes Fluorescentes/química , Ácido Hipocloroso/análise , Mitocôndrias/metabolismo , Nitrilas/química , Células A549 , Animais , Cumarínicos/toxicidade , Corantes Fluorescentes/toxicidade , Humanos , Limite de Detecção , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Nitrilas/toxicidade , Peixe-ZebraRESUMO
Drought is an important abiotic stress that seriously restricts crop productivity. An understanding of drought tolerance mechanisms offers guidance for cultivar improvement. In order to understand how a well-known wheat genotype Jinmai 47 responds to drought, we adopted the iTRAQ and LC/MS approaches and conducted proteomics analysis of leaves after exposure to 20% of polyethylene glycol-6000 (PEG)-induced stress for 4 days. The study identified 176 differentially expressed proteins (DEPs), with 65 (36.5%) of them being up-regulated, and 111 (63.5%) down-regulated. DEPs, located in cellular membranes and cytosol mainly, were involved in stress and redox regulation (51), carbohydrate and energy metabolism (36), amino acid metabolism (24), and biosynthesis of other secondary metabolites (20) primarily. Under drought stress, TCA cycle related proteins were up-regulated. Antioxidant system, signaling system, and nucleic acid metabolism etc. were relatively weakened. In comparison, the metabolism pathways that function in plasma dehydration protection and protein structure protection were strongly enhanced, as indicated by the improved biosynthesis of 2 osmolytes, sucrose and Proline, and strongly up-regulated protective proteins, LEA proteins and chaperones. SUS4, P5CSs, OAT, Rab protein, and Lea14-A were considered to be important candidate proteins, which deserve to be further investigated.
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Regulação da Expressão Gênica de Plantas , Pressão Osmótica , Proteínas de Plantas/genética , Proteoma/genética , Triticum/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Triticum/fisiologiaRESUMO
Glioblastoma (GBM) is the most common malignant brain tumor in adults. We designed an adeno-associated virus (AAV) vector for intracranial delivery of the secreted HSP70-targeted peptide APOPTIN derived from Apoptin to GBM tumors. We applied this therapy to GBM models using human U87MG glioma cells and GBM xenograft models in mice. In U87MG and U251MG cells, conditioned medium from AAV2-apoptin-derived peptide (ADP)-expressing cells induced 83% and 78% cell death. In mice bearing intracranial U87MG tumors treated with AAV2-ADP, treatment resulted in a significant decrease in tumor growth and longer survival in mice bearing orthotopic invasive GBM brain tumors. These data indicate that ssAAV2-ADP injection in the left hemisphere effectively prevented ipsilateral tumor growth but was insufficient to prevent distal tumor growth in the contralateral hemisphere. However, the systemic route is the most effective approach for treating widely dispersed tumors. In summary, systemic delivery of AAV2-ADP is an attractive approach for invasive GBM treatment.
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Neoplasias Encefálicas/terapia , Proteínas do Capsídeo/uso terapêutico , Glioblastoma/terapia , Animais , Apoptose , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proteínas do Capsídeo/administração & dosagem , Proteínas do Capsídeo/genética , Linhagem Celular Tumoral , Dependovirus/genética , Feminino , Técnicas de Transferência de Genes , Terapia Genética/métodos , Vetores Genéticos , Glioblastoma/genética , Glioblastoma/patologia , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/genética , Humanos , Camundongos , Camundongos Nus , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Soil salinity and alkalinity present a serious threat to global agriculture. However, most of the studies have focused on neutral salt stress, and the information on the metabolic responses of plants to alkaline salt stress is limited. This investigation aimed at determining the influence of neutral salt and alkaline salt stresses on the content of metal elements and metabolites in maize plant tissues, by using mixtures of various proportions of NaCl, NaHCO3, Na2SO4, and Na2CO3. RESULTS: We found that alkaline salt stress suppressed more pronouncedly the photosynthesis and growth of maize plants than salinity stress. Under alkaline salt stress conditions, metal ions formed massive precipitates, which ultimately reduced plant nutrient availability. On the other hand, high neutral salt stress induced metabolic changes in the direction of gluconeogenesis leading to the enhanced formation of sugars as a reaction contributing to the mitigation of osmotic stress. Thus, the active synthesis of sugars in shoots was essential to the development of salt tolerance. However, the alkaline salt stress conditions characterized by elevated pH values suppressed substantially the levels of photosynthesis, N metabolism, glycolysis, and the production of sugars and amino acids. CONCLUSIONS: These results indicate the presence of different defensive mechanisms responsible for the plant responses to neutral salt and alkaline salt stresses. In addition, the increased concentration of organic acids and enhanced metabolic energy might be potential major factors that can contribute to the maintenance intracellular ion balance in maize plants and counteract the negative effects of high pH under alkaline salt stress.
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Plântula/metabolismo , Estresse Fisiológico/fisiologia , Zea mays/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Metaboloma/fisiologia , Metais/metabolismo , Análise Multivariada , Pressão Osmótica , Fotossíntese/efeitos dos fármacos , Salinidade , Tolerância ao Sal , Plântula/efeitos dos fármacos , Plântula/fisiologia , Cloreto de Sódio/farmacologia , Sulfatos/farmacologia , Zea mays/efeitos dos fármacos , Zea mays/fisiologiaRESUMO
BACKGROUND: It is well known that salinization (high-pH) has been considered as a major environmental threat to agricultural systems. The aim of this study was to investigate the differences between salt stress and alkali stress in metabolic profiles and nutrient accumulation of wheat; these parameters were also evaluated to determine the physiological adaptive mechanisms by which wheat tolerates alkali stress. RESULTS: The harmful effect of alkali stress on the growth and photosynthesis of wheat were stronger than those of salt stress. High-pH of alkali stress induced the most of phosphate and metal ions to precipitate; as a result, the availability of nutrients significantly declined. Under alkali stress, Ca sharply increased in roots, however, it decreased under salt stress. In addition, we detected the 75 metabolites that were different among the treatments according to GC-MS analysis, including organic acids, amino acids, sugars/polyols and others. The metabolic data showed salt stress and alkali stress caused different metabolic shifts; alkali stress has a stronger injurious effect on the distribution and accumulation of metabolites than salt stress. These outcomes correspond to specific detrimental effects of a highly pH environment. CONCLUSIONS: Ca had a significant positive correlation with alkali tolerates, and increasing Ca concentration can immediately trigger SOS Na exclusion system and reduce the Na injury. Salt stress caused metabolic shifts toward gluconeogenesis with increased sugars to avoid osmotic stress; energy in roots and active synthesis in leaves were needed by wheat to develop salt tolerance. Alkali stress (at high pH) significantly inhibited photosynthetic rate; thus, sugar production was reduced, N metabolism was limited, amino acid production was reduced, and glycolysis was inhibited.
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Álcalis/farmacologia , Tolerância ao Sal/efeitos dos fármacos , Cloreto de Sódio/farmacologia , Estresse Fisiológico/fisiologia , Triticum/efeitos dos fármacos , Álcalis/metabolismo , Pressão Osmótica/fisiologia , Cloreto de Sódio/metabolismo , Triticum/metabolismoRESUMO
Leaf inclination angle (LIA) and tillering impact the winter wheat (Triticum aestivum L.) population canopy structure. Understanding their effects on water use (WU) parameters and yield can guide water-saving strategies through population control. In this study, six near-isogenic lines (NILs) and their parents were selected as materials. These special materials were characterized by varying tillering at the current sowing density, a similar genetic background, and, particularly, a gradient in mean flag leaf LIA. The investigation focused on the jointing to early grain-filling stage, the peak water requirement period of wheat crops. Population-scale transpiration (PT) and evaporation from the soil surface (E) were partitioned from total evapotranspiration (ET) by the means of micro-lysimeters. The results showed decreased PT, E, and ET with increased population density (PD) within a narrow density range derived from varying tillering across genotypes. Significant correlations existed between PD and ET, E, and PT, especially in the wettest 2017-2018 growing season. Within such narrow PD range, all the correlations between WU parameters and PD were negative, although some correlations were not statistically significant, thereby suggesting the population structure's predominant impact. No significant correlation existed between LIA and both ET and PT within the LIA range of 35°-65°. However, significant correlations occurred between LIA and E in two growing seasons. Genotypes with similar LIA but different PD produced varied ET; while with similar PD, the four pairs of genotypes with different LIA each consumed similar ET, thus highlighting PD's more crucial role in regulating ET. The yield increased with higher LIA, and showed a significant correlation, emphasizing the LIA's significant effect on yield. However, no correlation was observed with PD, indicating the minor effect of tillering at the current sowing density. Therefore these results might offer valuable insights for breeding water-saving cultivars and optimizing population structures for effective field water conservation.
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Folhas de Planta , Transpiração Vegetal , Solo , Triticum , Triticum/genética , Triticum/fisiologia , Triticum/crescimento & desenvolvimento , Folhas de Planta/fisiologia , Solo/química , Estações do Ano , Água/metabolismo , GenótipoRESUMO
Background: Sialyllacto-N-tetraose b (LSTb) is a component of human milk oligosaccharides. Due to its low concentration, the impact of LSTb on neurodevelopment remains largely unexplored. It is worth studying whether LSTb should be added to infant formula to simulate breast milk. This study aimed to investigate the effect of LSTb on the development of motor neurons of the central nervous system using a transgenic zebrafish model. Methods: Transgenic (Tg) zebrafish line (Hb9:GFP) was incubated with LSTb, and the axonal growth of caudal primary (CaP) neurons was assessed. Locomotor behavior was evaluated, and RNA sequencing (RNA-seq) was performed to identify the differentially expressed genes (DEGs). The expression of Slit2 and Slit3, genes involved in axon guidance, was further analyzed through real-time polymerase chain reaction (real-time PCR) and whole-mount in situ hybridization. Results: There was a significant increase in the number and length of CaP axon branches, suggesting that LSTb promotes CaP development. Behavioral analysis revealed enhanced locomotor activity in LSTb-treated larvae, indicating improved motor function. RNA-seq analysis identified 5,847 DEGs related to central nervous system neuron differentiation, including Slit2 and Slit3, which are known to contribute to axon guidance. In situ hybridization confirmed increased Slit2 expression in the central nervous system of LSTb-treated larvae. Conclusions: LSTb significantly influences motor neuron development, potentially through the upregulation of Slit2 and Slit3. This research provides valuable insights into the role of LSTb in neurodevelopment.
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The COVID-19 pandemic highlights the urgent need to develop effective small-molecule antivirals. Thirty-three novel biaryl amide derivatives were synthesized and evaluated for anti-coronaviral activity. Some significant SARs were uncovered and the intensive structure modifications led to the most active compounds 8b and 8h. The broad-spectrum anti-coronaviral effects of 8h were validated at RNA and protein levels. 8h inhibits coronavirus replication at multiple stages, from virus entry to virus dsRNA synthesis. The mechanism of action showed that 8h may simultaneously act on 3CLpro and TMPRSS2 to display anti-coronaviral effects. 8h combined with RdRp inhibitor showed synergistic inhibitory activity against coronavirus. This study confirmed that biaryl amide derivatives may be a new class of potential therapeutic agents against coronavirus with multiple target effect, worthy of further investigation.
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COVID-19 , SARS-CoV-2 , Humanos , Amidas/farmacologia , Pandemias , Antivirais/química , Inibidores de Proteases/farmacologiaRESUMO
Background: The role of androgen receptor (AR) in evaluating the prognosis of patients with endometrial cancer (EC) remains controversial. Here, we performed a meta-analysis to assess whether AR expression improves EC survival outcomes. Methods: We searched related articles published before August 2021 in PubMed, EMBASE, and Web of Science. The association between AR expression and patient prognosis was estimated with hazard ratios (HRs) and odds ratios (ORs) with their corresponding 95% confidence intervals (95% CIs). The review is registered on PROSPERO, registration number: CRD42021268591. Results: Ten studies including 1,485 patients were enrolled in the meta-analysis. The results showed that AR expression in EC tissues was associated with a better survival in crude analyses (HR = 1.63, 95% CI = 1.32-2.02, P < 0.001). However, no significant relation was found after the adjustment of the confounding factors (HR = 1.68, 95% CI = 0.75-3.75, P = 0.205). In subgroup analyses, grade 1-2 disease, stage I-II disease, negative lymph node status, and lack of the lymphovascular invasion were more common in AR-positive groups (OR = 0.47, 0.48, 0.37, and 0.57; 95% CI = 0.45-0.62, 0.35-0.65, 0.24-0.56, and 0.37-0.89). Furthermore, AR expression was more common in endometrioid cancers (OR = 2.39, 95% CI = 1.79-3.20). Conclusions: AR expression is significantly associated favorable characteristics including low-grade disease, early-stage disease, negative lymph node status, and lack of the lymphovascular invasion and a specific histology-endometrioid cancer. However, AR is not an independent prognostic factor.
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To clarify the differences in growth and yield responses to drought stress among genotypes contrasting in environmental background, dryland and irrigated genotypes, as well as the underlying biochemical mechanism would provide valuable information for developing superior dryland cultivars. Pot experiments for the whole life cycle in fifteen genotypes and comparative metabolomics analysis for seedlings between two drought tolerant (DT) dryland genotypes and two drought sensitive (DS) irrigated ones were carried out. The DT dryland genotypes suffered heavy biomass loss during severer drought but showed minor yield loss ultimately, while the DS irrigated ones showed minor biomass loss but greater yield loss. Additionally, the superior DT dryland genotypes showed better yield performance under both drought stress and well-watered conditions, indicating their possessing both drought tolerance and high yield potential traits. Suffering severer drought stress, seedling leaves of the DS irrigated genotypes increased some amino acids and organic acids to maintain cell metabolism and accumulate more biomass. Proline in particular was overproduced, which might cause toxicity to cell systems and lead to enormous yield loss ultimately. In contrast, DT dryland genotypes increased the beneficial amino acid and phenolic acids to enhance cell self-protection for alleviating drought damage and efficiently minimized yield loss ultimately.
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At the organelle level, pathogenesis due to abnormal concentrations of cysteine (Cys) is of great significance for the early diagnosis and treatment of related diseases. Generally speaking, organelle localization requires the participation of specific target groups, which increases the difficulty of synthesis. Herein, through simple synthesis, a novel biflavone derivative (BFD) that exhibits excited-state intramolecular proton transfer (ESIPT) was obtained and successfully located in mitochondria without target groups. The probe BFD can distinguish Cys from Hcy and GSH with a rapid response (< 5 s) and showed visual detection for Cys with a large Stokes shift (about 260 nm). Because of its nanomorphology in solution and surface functional groups, the probe BFD can enter the cell smoothly and achieve mitochondrial localization. Owing to its excellent optical performance, the probe BFD was successfully applied to the imaging of endogenous Cys in HeLa cells and zebrafish.
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Biflavonoides/química , Cisteína/análise , Corantes Fluorescentes/química , Mitocôndrias/química , Animais , Células HeLa , Humanos , Prótons , Peixe-ZebraRESUMO
Predicting the change in carbon storage in regions of high carbon uptake and those under highly intensive human disturbance is crucial for regional ecosystem management to promote sustainable development of the economy and ecology in the future. We use a process-based model to estimate the terrestrial carbon storage in Yangtze River Economic Belt (YREB) and to predict the change of carbon storage over the next 100 years. The results show that the vegetation carbon (VC) and soil organic carbon (SOC) storage were 8.97 and 28.85 Pg C in the YREB from 1981 to 2005, respectively. The highest VC density is distributed in the southern region of the YREB, and the highest SOC density distributes in subalpine and alpine area of the western region of the YREB. Carbon storage in the YREB continued to increase from 1981 to 2005 and in future projections, under both the representative concentration pathway 4.5 (RCP4.5) and the RCP8.5 scenarios. The increased rate of carbon storage in the YREB under the RCP8.5 scenario is higher than that under the RCP4.5 scenario. Under the RCP4.5 scenario, the increasing trend of VC storage tends to be reduced after the 2060s; conversely, the increase of both VC and SOC is accelerated after the 2050s under the RCP8.5 scenario. The SOC density in Western Sichuan will decrease in the future, especially under the RCP8.5 scenario. Western Sichuan has the highest SOC density in the YREB; therefore, it is important to manage the ecosystems there in order to cope with significant warming. The positive impact of warming and the CO2 fertilization effect on vegetation growth and carbon uptake will be predominantly attributed to the increase of terrestrial carbon storage in the YREB. However, warming will stimulate the decomposition of soil organic carbon, contributing directly to reducing SOC storage in high-altitude regions (e.g., alpine and subalpine regions of Western Sichuan).
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Forests play an important role in regulating climate change and maintaining carbon balance. To explore the carbon storage and carbon sequestration rate of national forest parks is of great significance for carbon sequestration capacity assessment and sustainable forest management. A process-based ecosystem model (CEVSA2 model) was used to simulate the spatial distribution of carbon density, carbon storage and carbon sequestration rate of 881 national forest parks in China during 1982-2017. The results showed that the average carbon density of national forest parks was 255.18 t C·hm-2, being higher than the average carbon density of forest ecosystem in China. In 2017, the total carbon storage of national forest parks increased to 3.56 Pg C, accounting for 11.0%-12.2% of the total carbon storage in national forest ecosystems. During 1982-2017, the average carbon sequestration rate of national forest parks reached 0.45 t C·hm-2·a-1, and the carbon sequestration rate of all national forest parks was above 0.30 t C·hm-2·a-1. National forest parks in the northeast and southwest of China had the highest total carbon storage. The national forest parks in northeast of China had the highest soil organic carbon sequestration rate, while those in eastern China and central southern China had the highest biomass carbon sequestration rate. The area of national forest parks accounted for 5.8% of the total forest area of China, playing an important role in forest carbon sink management of China. Accurate assessment of the growth status, carbon sequestration potential and carbon absorption characteristics of national forest parks could provide reference for the comprehensive assessment of ecosystem service of forest parks in China.
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Sequestro de Carbono , Carbono , Biomassa , Carbono/análise , China , Ecossistema , Florestas , Solo , ÁrvoresRESUMO
Hypochlorite is an important active oxygen species formed in living organisms, and rapid and highly sensitive detection of trace hypochlorite is of great significance for understanding the mechanism of diseases caused by abnormal hypochlorite concentrations at an early stage. Although aggregation-induced emission (AIE) probes are highly important for analyte de-tection in living organisms, there is a lack of AIE probes for hypochlorite detection. In this study, two AIE probes based on benzothiazole derivatives (BTD-1 and BTD-2) were designed and synthesized. Both probes exhibited good AIE charac-teristics and allowed different visual detection for hypochlorite. Additionally, the two probes could be used to detect endogenous hypochlorite in mitochondria and were successfully applied for in vivo hypochlorite imaging in zebrafish.
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Corantes Fluorescentes/química , Ácido Hipocloroso/metabolismo , Mitocôndrias/metabolismo , Imagem Óptica/métodos , Peixe-Zebra , Animais , Benzotiazóis/química , Sobrevivência Celular , Células HeLa , HumanosRESUMO
A good understanding of the response of photosynthesis rate (P N) and transpiration rate (Tr) to stomatal alteration during the diurnal variations is important to cumulative photosynthetic production and water loss of crops. Six wheat genotypes were studied for 2 years with pot cultivation in rain-shelter. Among different genotypes, stomatal conductance (g s) was significantly correlated with both P N and Tr. But for each genotype, though g s was significantly correlated with P N regardless of relative air humidity (RH) status and it was also significantly correlated with Tr under lower RH (LRH, 15.4%) and moderate RH (MRH, 28.3%), it was not correlated with Tr under higher RH (HRH, 36.7%) during the diurnal changes. The conditional correlation between g s and Tr of wheat evoked new thinking on the relationships among g s, P N and Tr. Path analysis was further carried out to clarify the correlations of g s with the four atmospheric factors, that of Tr with g s and the four factors and the direct and indirect effects of the factors, during their diurnal dynamic variation. The effects of these factors on g s or Tr were related to RH. All the four factors had a much higher correlation with g s under HRH than that under LRH and MRH. Air temperature (T) had a rather higher direct effect than RH and photosynthetically active radiation (PAR). Also, the other factors had a much higher indirect effect on g s through vapor pressure deficit (VPD) and T. Transpiration rate was highly correlated with g s under LRH and MRH, with g s having a higher direct effect on it. In comparison, Tr was not correlated with g s under HRH but highly correlated with the atmospheric factors, with T, RH, and PAR having a higher indirect effect through VPD.
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Twelve winter wheat (Triticum aestivum) genotypes were examined for differences in grain yield, water use efficiency (WUE), and stable carbon isotope composition (δ13C) in flag leaves. The plants were subjected to rain-fed treatment and supplemental irrigation at the jointing and anthesis stages, during the 2015-2016 and 2016-2017 winter wheat growing seasons. The relationships between δ13C with grain yield and WUE were analyzed under two different water environments. The results indicated that there were significant differences in δ13C, grain yield, and WUE among wheat genotypes both under rain-fed and supplemental irrigation conditions. The δ13C values increased with grain-filling proceeding, the δ13C being lower under supplemental irrigation treatment than that under rain-fed treatment. The relationships between the average of δ13C with grain yield and WUE were significantly positive during three measurement periods (R2 = 0.5785 - 0.8258), whether under rain-fed or irrigation environments. This suggests that δ13C might be associated with the grain yield and WUE in winter wheat under rain-fed and supplemental irrigation conditions in the climate region of the northwest Huang-Huai-Hai Plain of China.