Effects of drought and rehydration on the growth and physiological characteristics of mustard seedlings

The mustard variety Felicia was used to analyze the response and compensation effects of growth and physiology under drought stress and rehydration conditions at the seedling stage. The seedlings were exposed to different levels of drought stress simulated by polyethylene glycol (PEG). The growth parameters, fresh weight, chlorophyll fluorescence, and antioxidant system were measured. The results showed that drought stress inhibited the growth of roots and shoots and reduced the performance of photosystem II (PS II). After rehydration, the root length and fresh weight of plants rapidly increased, and the performance index (PIABS) was found to be higher compared with the control, which suggested a compensative effect. The chlorophyll content was significantly reduced under moderate and severe drought stress. However, it increased under mild stress conditions. After rehydration, the chlorophyll content under moderate and severe stress did not return to the levels of control, and there was no significant difference between mild stress and the control. Under drought stress, the activities of antioxidant enzymes and content of malondialdehyde (MDA) increased significantly in the leaves. After rehydration, MDA and the activities of antioxidant enzyme were higher than those of the control group, particularly under moderate and severe stress. Therefore, these results suggest that mustard is strongly adapted to mild drought stress through the efficient activities of antioxidant enzymes activity and photosynthesis, as well as its rapid recovery after rehydration

Effects of Dioscorea polystachya \u27yam gruel\u27 on the cognitive function of diabetic rats with focal cerebral ischemia-reperfusion injury via the gut-brain axis

© 2020 Pang et al. Published by IMR press. Focal cerebral ischemia-reperfusion injury is closely related to hyperglycemia and gut microbiota imbalance, while gut microbiota contributes to the regulation of brain function through the gut-brain axis. Previous studies in patients with diabetes have found that \u27yam gruel\u27 is a classic medicated diet made from Dioscorea polystachya, increases the content of Bifidobacterium, regulates oxidative stress, and reduces fasting blood glucose levels. The research reported here investigated the effects of \u27yam gruel\u27 on the cognitive function of streptozotocin-induced diabetic rats with focal cerebral ischemia-reperfusion injury and explored the mechanism underlying the role of the gut-brain axis in this process. \u27Yam gruel\u27 was shown to improve cognitive function as indicated by increased relative content of probiotic bacteria, and short-chain fatty acids in the intestinal tract and cerebral cortex reduced oxidative stress and inflammatory response and promotion of the expression of neurotransmitters and brain-derived neurotrophic factor. Thus, it is concluded that \u27yam gruel\u27 has a protective effect on cognitive function via a mechanism related to the gut-brain axis

Dynamic non-line-of-sight imaging system based on the optimization of point spread functions

Non-line-of-sight (NLOS) imaging reveals hidden objects reflected from diffusing surfaces or behind scattering media. NLOS reconstruction is usually achieved by computational deconvolution of time-resolved transient data from a scanning single-photon avalanche diode (SPAD) detection system. However, using such a system requires a lengthy acquisition, impossible for capturing dynamic NLOS scenes. We propose to use a novel SPAD array and an optimization-based computational method to achieve NLOS reconstruction of 20 frames per second (fps). The imaging system's high efficiency drastically reduces the acquisition time for each frame. The forward projection optimization method robustly reconstructs NLOS scenes from low SNR data collected by the SPAD array. Experiments were conducted over a wide range of dynamic scenes in comparison with confocal and phase-field methods. Under the same exposure time, the proposed algorithm shows superior performances among state-of-the-art methods. To better analyze and validate our system, we also used simulated scenes to validate the advantages through quantitative benchmarks such as PSNR, SSIM and total variation analysis. Our system is anticipated to have the potential to achieve video-rate NLOS imaging

Aggregation Pheromone for an Invasive Mussel Consists of a Precise Combination of Three Common Purines.

Most marine benthic invertebrates have a pelagic larval phase, after which they settle preferentially on or near conspecific adults, forming aggregations. Although settlement pheromones from conspecific adults have been implicated as critical drivers of aggregation for more than 30 years, surprisingly few have been unambiguously identified. Here we show that in the invasive dreissenid mussel Mytilopsis sallei (an ecological and economic pest), three common purines (adenosine, inosine, and hypoxanthine) released from adults in a synergistic and precise ratio (1:1.125:3.25) serve as an aggregation pheromone by inducing conspecific larval settlement and metamorphosis. Our results demonstrate that simple common metabolites can function as species-specific pheromones when present in precise combinations. This study provides important insights into our understanding of the ecology and communication processes of invasive organisms and indicates that the combination and ratio of purines might be critical for purine-based signaling systems that are fundamental and widespread in nature

Aggregation Pheromone for an Invasive Mussel Consists of a Precise Combination of Three Common Purines

Summary(#br)Most marine benthic invertebrates have a pelagic larval phase, after which they settle preferentially on or near conspecific adults, forming aggregations. Although settlement pheromones from conspecific adults have been implicated as critical drivers of aggregation for more than 30 years, surprisingly few have been unambiguously identified. Here we show that in the invasive dreissenid mussel Mytilopsis sallei (an ecological and economic pest), three common purines (adenosine, inosine, and hypoxanthine) released from adults in a synergistic and precise ratio (1:1.125:3.25) serve as an aggregation pheromone by inducing conspecific larval settlement and metamorphosis. Our results demonstrate that simple common metabolites can function as species-specific pheromones when present in precise combinations. This study provides important insights into our understanding of the ecology and communication processes of invasive organisms and indicates that the combination and ratio of purines might be critical for purine-based signaling systems that are fundamental and widespread in nature

Identification and drug metabolic characterization of four new CYP2C9 variants CYP2C9*72-*75 in the Chinese Han population

Cytochrome 2C9 (CYP2C9), one of the most important drug metabolic enzymes in the human hepatic P450 superfamily, is required for the metabolism of 15% of clinical drugs. Similar to other CYP2C family members, CYP2C9 gene has a high genetic polymorphism which can cause significant racial and inter-individual differences in drug metabolic activity. To better understand the genetic distribution pattern of CYP2C9 in the Chinese Han population, 931 individuals were recruited and used for the genotyping in this study. As a result, seven synonymous and 14 non-synonymous variations were identified, of which 4 missense variants were designated as new alleles CYP2C9*72, *73, *74 and *75, resulting in the amino acid substitutions of A149V, R150C, Q214H and N418T, respectively. When expressed in insect cell microsomes, all four variants exhibited comparable protein expression levels to that of the wild-type CYP2C9 enzyme. However, drug metabolic activity analysis revealed that these variants exhibited significantly decreased catalytic activities toward three CYP2C9 specific probe drugs, as compared with that of the wild-type enzyme. These data indicate that the amino acid substitution in newly designated variants can cause reduced function of the enzyme and its clinical significance still needs further investigation in the future

Tet and TDG Mediate DNA Demethylation Essential for Mesenchymal-to-Epithelial Transition in Somatic Cell Reprogramming

SummaryTet-mediated DNA oxidation is a recently identified mammalian epigenetic modification, and its functional role in cell-fate transitions remains poorly understood. Here, we derive mouse embryonic fibroblasts (MEFs) deleted in all three Tet genes and examine their capacity for reprogramming into induced pluripotent stem cells (iPSCs). We show that Tet-deficient MEFs cannot be reprogrammed because of a block in the mesenchymal-to-epithelial transition (MET) step. Reprogramming of MEFs deficient in TDG is similarly impaired. The block in reprogramming is caused at least in part by defective activation of key miRNAs, which depends on oxidative demethylation promoted by Tet and TDG. Reintroduction of either the affected miRNAs or catalytically active Tet and TDG restores reprogramming in the knockout MEFs. Thus, oxidative demethylation to promote gene activation appears to be functionally required for reprogramming of fibroblasts to pluripotency. These findings provide mechanistic insight into the role of epigenetic barriers in cell-lineage conversion

Activation of Nrf2/HO-1 Pathway by Nardochinoid C Inhibits Inflammation and Oxidative Stress in Lipopolysaccharide-Stimulated Macrophages

The roots and rhizomes of Nardostachys chinensis have neuroprotection and cardiovascular protection effects. However, the specific mechanism of N. chinensis is not yet clear. Nardochinoid C (DC) is a new compound with new skeleton isolated from N. chinensis and this study for the first time explored the anti-inflammatory and anti-oxidant effect of DC. The results showed that DC significantly reduced the release of nitric oxide (NO) and prostaglandin E2 (PGE2) in lipopolysaccharide (LPS)-activated RAW264.7 cells. The expression of pro-inflammatory proteins including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were also obviously inhibited by DC in LPS-activated RAW264.7 cells. Besides, the production of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were also remarkably inhibited by DC in LPS-activated RAW264.7 cells. DC also suppressed inflammation indicators including COX-2, PGE2, TNF-α, and IL-6 in LPS-stimulated THP-1 macrophages. Furthermore, DC inhibited the macrophage M1 phenotype and the production of reactive oxygen species (ROS) in LPS-activated RAW264.7 cells. Mechanism studies showed that DC mainly activated nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, increased the level of anti-oxidant protein heme oxygenase-1 (HO-1) and thus produced the anti-inflammatory and anti-oxidant effects, which were abolished by Nrf2 siRNA and HO-1 inhibitor. These findings suggested that DC could be a new Nrf2 activator for the treatment and prevention of diseases related to inflammation and oxidative stress