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1.
Int J Med Sci ; 19(1): 98-104, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34975303

RESUMO

Isolation of quality RNA from articular cartilage has been challenging due to low cellularity and the high abundance of extracellular matrix and proteoglycan proteins. Recently developed methods for isolation of high quality RNA from cartilage are more applicable to larger cartilage specimens typically weighing at least 25 mg. While these methods generate RNA suitable for analysis, they are less successful with smaller tissue inputs. For the study of small focal defect cartilage specimens an improved RNA extraction method is needed. Here we report a protocol for direct RNA isolation from less than 3 mg of wet weight rabbit articular cartilage for quantitative microarray gene profiling. This protocol is useful for identifying differentially expressed genes in chondrocytes following focal cartilage repair and can potentially be adopted for gene expression analysis of cartilage biopsy specimens from human joints.

2.
Water Res ; 210: 117994, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34974345

RESUMO

Water diversion has been widely used to address water shortages and security issues. However, its long-term ecological impacts, particularly on the biodiversity and structure of the local community, have often been neglected due to limitations of conventional biomonitoring. Taking the water diversion projects from Yangtze River to Tai Lake (WDYT) as examples, environmental DNA (eDNA) metabarcoding was used to investigate the potential ecological impact of water diversion on the connected basins. Firstly, 136 phytoplankton genera/species, including 31 cyanobacteria and 105 eukaryotic phytoplankton (Euk-phytoplankton), were identified from 26 sites by metabarcoding of 16S rDNA V3 and 18S rDNA V9 regions. eDNA metabarcoding showed an obvious advantage in detecting nano/pico-plankton (< 20 µm in size) compared with the morphological approach. Secondly, more shared taxa and higher similarity of community composition were observed in Gonghu Bay/Zhushan Bay with its connected river than with the center of Tai Lake, indicating that water diversions were accelerating the biotic homogenization between different waterbodies. Skeletonema potamos, the native species of Yangtze River (4.04% of the total Euk-phytoplankton reads) was detected in different connecting regions of Tai Lake (0.03%-0.54% of the total Euk-phytoplankton reads), where its relative abundance was consistent with the influence of water diversion from Yangtze River. Furthermore, the introduction of S. potamos significantly affected the local community compositions of phytoplankton in Tai Lake. Finally, the ecological effect (e.g., taxa richness, community composition and species invasion) of the WDYT on phytoplankton in the west of Tai Lake was more significant than that in the east, which was consistent with the scale (volume and duration) of the water diversion projects. Overall, this study highlights the value of eDNA biomonitoring in the ecological impact assessment of water transfer projects.

3.
Cell Death Dis ; 13(1): 41, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35013118

RESUMO

Despite the great advances in target therapy, lung cancer remains the top cause of cancer-related death worldwide. G protein-coupled receptor neurokinin-1 (NK1R) is shown to play multiple roles in various cancers; however, the pathological roles and clinical implication in lung cancer are unclarified. Here we identified NK1R as a significantly upregulated GPCR in the transcriptome and tissue array of human lung cancer samples, associated with advanced clinical stages and poor prognosis. Notably, NK1R is co-expressed with epidermal growth factor receptor (EGFR) in NSCLC patients' tissues and co-localized in the tumor cells. NK1R can crosstalk with EGFR by interacting with EGFR, transactivating EGFR phosphorylation and regulating the intracellular signaling of ERK1/2 and Akt. Activation of NK1R promotes the proliferation, colony formation, EMT, MMP2/14 expression, and migration of lung cancer cells. The inhibition of NK1R by selective antagonist aprepitant repressed cell proliferation and migration in vitro. Knockdown of NK1R significantly slowed down the tumor growth in nude mice. The sensitivity of lung cancer cells to gefitinib/osimertinib is highly increased in the presence of the selective NK1R antagonist aprepitant. Our data suggest that NK1R plays an important role in lung cancer development through EGFR signaling and the crosstalk between NK1R and EGFR may provide a potential therapeutic target for lung cancer treatment.

5.
Proc Natl Acad Sci U S A ; 119(2)2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-34987100

RESUMO

Myeloid lineage cells such as macrophages and dendritic cells (DCs), targeted by HIV-1, are important vehicles for virus dissemination through the body as well as viral reservoirs. Compared to activated lymphocytes, myeloid cells are collectively more resistant to HIV-1 infection. Here we report that NRP-1, encoding transmembrane protein neuropilin-1, is highly expressed in macrophages and DCs but not CD4+ T cells, serving as an anti-HIV factor to inhibit the infectivity of HIV-1 progeny virions. Silencing NRP-1 enhanced the transmission of HIV-1 in macrophages and DCs significantly and increased the infectivity of the virions produced by these cells. We further demonstrated that NRP-1 was packaged into the progeny virions to inhibit their ability to attach to target cells, thus reducing the infectivity of the virions. These data indicate that NRP-1 is a newly identified antiviral protein highly produced in both macrophages and DCs that inhibit HIV-1 infectivity; thus, NRP-1 may be a novel therapeutic strategy for the treatment of HIV-1 infection.

6.
Plant Physiol ; 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34983053

RESUMO

Light affects many physiological and developmental processes of plants by regulating the expression and activity of light responsive proteins. Among them, phytochrome interacting factors (PIFs) play pivotal roles in the regulation of anthocyanin accumulation and hypocotyl growth. However, the molecular mechanism is not well understood, especially in woody plants, such as apple (Malus × domestica). In this study, we identified a light responsive PIF protein, MdPIF7, in apple and investigated the molecular mechanism of its regulation of anthocyanin biosynthesis and hypocotyl growth. We found that overexpression of MdPIF7 decreased anthocyanin accumulation in transgenic apple materials and promoted hypocotyl elongation in ectopically expressed Arabidopsis (Arabidopsis thaliana). Further investigation showed that MdPIF7 functioned by interacting with B-box 23 (MdBBX23), a positive regulator of anthocyanin biosynthesis in apple and hypocotyl growth inhibition in ectopically expressed Arabidopsis, and attenuating the transcriptional activation of MdBBX23 on LONG HYPOCOTYL 5 (MdHY5). In addition, MdPIF7 interacted with basic region leucine zipper 44 (MdbZIP44) and ethylene response factor 38 (MdERF38), two positive regulators of anthocyanin biosynthesis, and it negatively regulated MdbZIP44- and MdERF38-promoted anthocyanin accumulation by interfering with the interaction between MdbZIP44/MdERF38 and MdMYB1. Taken together, our results reveal that MdPIF7 regulates anthocyanin biosynthesis in apple and hypocotyl growth in ectopically expressed Arabidopsis through MdPIF7-MdBBX23-MdHY5 and MdPIF7-MdbZIP44/MdERF38-MdMYB1 modules. Our findings enrich the functional studies of PIF proteins and provide insights into the molecular mechanism of PIF-mediated anthocyanin biosynthesis and hypocotyl growth.

7.
Nat Commun ; 13(1): 216, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35017521

RESUMO

Flexoelectricity is a type of ubiquitous and prominent electromechanical coupling, pertaining to the electrical polarization response to mechanical strain gradients that is not restricted by the symmetry of materials. However, large elastic deformation is usually difficult to achieve in most solids, and the strain gradient at minuscule is challenging to control. Here, we exploit the exotic structural inhomogeneity of grain boundary to achieve a huge strain gradient (~1.2 nm-1) within 3-4-unit cells, and thus obtain atomic-scale flexoelectric polarization of up to ~38 µC cm-2 at a 24° LaAlO3 grain boundary. Accompanied by the generation of the nanoscale flexoelectricity, the electronic structures of grain boundaries also become different. Hence, the flexoelectric effect at grain boundaries is essential to understand the electrical activities of oxide ceramics. We further demonstrate that for different materials, altering the misorientation angles of grain boundaries enables tunable strain gradients at the atomic scale. The engineering of grain boundaries thus provides a general and feasible pathway to achieve tunable flexoelectricity.

8.
Cells ; 11(2)2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-35053312

RESUMO

Tris(1,3-Dichloro-2-propyl)phosphate (TDCPP) is an organophosphorus flame retardant (OPFR) widely used in a variety of consumer products (plastics, furniture, paints, foams, and electronics). Scientific evidence has affirmed the toxicological effects of TDCPP in in vitro and in vivo test models; however, its genotoxicity and carcinogenic effects in human cells are still obscure. Herein, we present genotoxic and carcinogenic properties of TDCPP in human liver cells (HepG2). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and neutral red uptake (NRU) assays demonstrated survival reduction in HepG2 cells after 3 days of exposure at higher concentrations (100-400 µM) of TDCPP. Comet assay and flow cytometric cell cycle experiments showed DNA damage and apoptosis in HepG2 cells after 3 days of TDCPP exposure. TDCPP treatment incremented the intracellular reactive oxygen species (ROS), nitric oxide (NO), Ca2+ influx, and esterase level in exposed cells. HepG2 mitochondrial membrane potential (ΔΨm) significantly declined and cytoplasmic localization of P53, caspase 3, and caspase 9 increased after TDCPP exposure. qPCR array quantification of the human cancer pathway revealed the upregulation of 11 genes and downregulation of two genes in TDCPP-exposed HepG2 cells. Overall, this is the first study to explicitly validate the fact that TDCPP bears the genotoxic, hepatotoxic, and carcinogenic potential, which may jeopardize human health.

9.
Support Care Cancer ; 30(1): 875-885, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34392426

RESUMO

OBJECTIVES: To clarify the influence of hemoglobin on cancer cachexia and to determine whether hemoglobin affects the prognosis or quality of life of patients with cancer cachexia and whether these effects are caused by an interaction between hemoglobin and other factors. MATERIAL AND METHODS: This study was a multicenter cohort of 2715 patients with cancer cachexia diagnosed from June 2012 to December 2019. The primary outcomes and measures were overall survival (OS) time and all-cause mortality. The association between hemoglobin and all-cause mortality was evaluated using hazard ratios (HRs) and the restricted cubic spline model with a two-sided p-value. Optimal stratification was used to determine the threshold value. We also evaluated the cross-classification of hemoglobin and each variable with survival. RESULTS: Among the 2715 participants diagnosed with cancer cachexia, 1592 (58.6%) were male, and the mean (SD) age was 58.8 (11.7) years. The optimal cutoff point for hemoglobin as a predictor of cancer cachexia mortality was 140 g/L for males and 101 g/L for females in our research. The decrease in hemoglobin was positively correlated with all-cause mortality. These associations were consistent across cancer subtypes. In the multivariable analysis, after adjusting for sex, age, TNM stage, tumor type, radiotherapy, chemotherapy, Karnofsky performance status score, and other factors, patients diagnosed with cancer cachexia who had low hemoglobin levels were more likely to have a worse prognosis (HR 2.40; 95% CI, 1.12-1.51). CONCLUSION: Our results suggested that the proposed hemoglobin cutoff point would be valuable for prognostic prediction in patients with cancer cachexia, especially for long-term prognosis.


Assuntos
Caquexia , Neoplasias , Caquexia/epidemiologia , Caquexia/etiologia , Estudos de Coortes , Feminino , Hemoglobinas , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Prognóstico , Qualidade de Vida , Estudos Retrospectivos
10.
Food Microbiol ; 102: 103925, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809951

RESUMO

Antibacterial activity against Escherichia coli O157:H7 and Staphylococcus aureus of five typical plant-derived compounds [gallic acid (G.A), citral (Cit), thymol (Thy), salicylic acid (S.A), lauric acid (L.A)] were investigated by determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI). The results showed that only a combination of Thy and G.A (TGA), with a concentration of 0.1 and 1.25 mg/mL, respectively, had a synergistic effect (FICI = 0.5) on both E. coli O157:H7 and S. aureus. The amount of Thy and G.A in mixture were four-fold lower than the MICs of the individuals shown to cause the equivalent antimicrobial activity in trypticase soy broth (TSB). The microbial reduction obtained in TSB with addition of TGA were significantly higher (P < 0.05) than the reduction shown for the broth supplemented with the separated phenolics. TGA caused the changes of morphology and membrane integrity of bacteria. Additionally, the application of TGA on fresh-cut tomatoes are investigated. Fresh-cut tomatoes inoculated with E. coli O157:H7and S. aureus were washed for 2min, 5min, 10min at 4 °C, 25 °C, 40 °C in 0.3% NaOCl, or water containing TGA at various concentrations. Overall, the reduction of TGA achieved against S. aureus is higher than E. coli O157:H7. Same concentrations of combined antimicrobials at a temperature of 40 °C further increased the degree of microbial inactivation, with an additional 0.89-1.51 log CFU/g reduction compared to that at 25 °C. Moreover, 1/2MICThy+1/2MICG.A at 25 °C for 10min or 40 °C for 5min were generally acceptable with sensorial scores higher than 7. Our results showed that TGA could work synergistically on the inactivation of the tested bacteria and may be used as an alternative disinfectant of fresh produce.


Assuntos
Anti-Infecciosos , Escherichia coli O157 , Ácido Gálico , Lycopersicon esculentum , Staphylococcus aureus , Timol , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Escherichia coli O157/efeitos dos fármacos , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Ácido Gálico/farmacologia , Lycopersicon esculentum/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Timol/farmacologia
11.
Sci Total Environ ; 805: 150366, 2022 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-34818752

RESUMO

The frequent detection of polychlorinated diphenyl ethers (PCDEs) in aquatic systems has aroused widespread concerns, however, their potential hazard to aquatic ecosystems has been poorly understood. Here the acute toxicity of 12 PCDE congeners was evaluated in three model aquatic organisms representing different trophic levels following OECD test guidelines, including green algae (Scenedesmus obliquus), water flea (Daphnia magna), and zebrafish (Danio rerio). Dose-dependent increases in growth inhibition and mortality were observed for all tested PCDE congeners. Most of the PCDE congeners, in particular 3,3',4,4'-tetra-CDE, were highly toxic to the three aquatic organisms with EC50 or LC50 values below 1 mg L-1. Their toxicities were generally comparable with those of certain polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). Moreover, D. magna was the most sensitive species among the three aquatic organisms. In addition, the EC50 or LC50 values had an extremely significant correlation with the n-octanol-water partition coefficient (logKow) of the PCDE congeners. The established quantitative structure-property relationship (QSPR) models indicated that the molecular polarizability (α) could significantly influence the acute toxicity of PCDEs on Daphnia magna and Danio rerio, and the energy of the lowest unoccupied molecular orbital (ELUMO) is the key factor of the acute toxicity of PCDEs in Scenedesmus obliquus. In addition, even at environmental levels, 3,3',4,4'-tetra-CDE could induced seveve oxidative damages in the three aquactic species. These findings would contribute to the understanding of adverse effects of PCDEs in aquatic organisms.


Assuntos
Scenedesmus , Poluentes Químicos da Água , Animais , Organismos Aquáticos , Daphnia , Ecossistema , Éteres Difenil Halogenados/toxicidade , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
12.
Environ Sci Technol ; 2021 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-34882399

RESUMO

Biological quality elements have been developed worldwide to assess whether a water body is in a good status or not. However, current studies mainly focus on a single taxonomic group or a small set of species, often limited by methods of morphological identification, and lack further aspects of biodiversity (e.g., across taxa and multiple attributes) and ecosystem functions. Here, we advance a framework for assessing the river's ecological status based on complete biodiversity data measured by environmental DNA (eDNA) metabarcoding and measurements of ecosystem functions in addition to physicochemical elements across a large riverine system in China. We identified 40 indicators of biodiversity and ecosystem functions, covering five taxonomic groups from bacteria to invertebrates, and associated with multiple attributes of biodiversity and ecosystem functions. Our data show that human impact on ecosystems could be accurately predicted by these eDNA-based indicators and ecosystem functions, using cross-validation with a known stressor gradient. Moreover, indices based on these indicators of biodiversity and ecosystem functions not only distinguish the physicochemical characteristics of the sites but also improve the assessment accuracy of 20-30% for the river's ecological status. Overall, by incorporating eDNA-based biodiversity with physicochemical and ecosystem functional elements, the multidimensional perspectives of ecosystem states provide additional information to protect and maintain a good ecological status of rivers.

13.
Environ Int ; 159: 107009, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34883459

RESUMO

Endocrine-disrupting chemicals (EDCs) can compete with endogenous hormones and bind to the orthosteric site of nuclear receptors (NRs), affecting normal endocrine system function and causing severe symptoms. Recently, a series of pharmaceuticals and personal care products (PPCPs) have been discovered to bind to the allosteric sites of NRs and induce similar effects. However, it remains unclear how diverse EDCs work in this new way. Therefore, we have systematically summarized the allosteric sites and underlying mechanisms based on existing studies, mainly regarding drugs belonging to the PPCP class. Advanced methods, classified as structural biology, biochemistry and computational simulation, together with their advantages and hurdles for allosteric site recognition and mechanism insight have also been described. Furthermore, we have highlighted two available strategies for virtual screening of numerous EDCs, relying on the structural features of allosteric sites and lead compounds, respectively. We aim to provide reliable theoretical and technical support for a broader view of various allosteric interactions between EDCs and NRs, and to drive high-throughput and accurate screening of potential EDCs with non-competitive effects.

14.
Int J Mol Sci ; 22(23)2021 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-34884713

RESUMO

Hydrogen sulfide (H2S) plays a crucial role in regulating chilling tolerance. However, the role of hydrogen peroxide (H2O2) and auxin in H2S-induced signal transduction in the chilling stress response of plants was unclear. In this study, 1.0 mM exogenous H2O2 and 75 µM indole-3-acetic acid (IAA) significantly improved the chilling tolerance of cucumber seedlings, as demonstrated by the mild plant chilling injury symptoms, lower chilling injury index (CI), electrolyte leakage (EL), and malondialdehyde content (MDA) as well as higher levels of photosynthesis and cold-responsive genes under chilling stress. IAA-induced chilling tolerance was weakened by N, N'-dimethylthiourea (DMTU, a scavenger of H2O2), but the polar transport inhibitor of IAA (1-naphthylphthalamic acid, NPA) did not affect H2O2-induced mitigation of chilling stress. IAA significantly enhanced endogenous H2O2 synthesis, but H2O2 had minimal effects on endogenous IAA content in cucumber seedlings. In addition, the H2O2 scavenger DMTU, inhibitor of H2O2 synthesis (diphenyleneiodonium chloride, DPI), and IAA polar transport inhibitor NPA reduced H2S-induced chilling tolerance. Sodium hydrosulfide (NaHS) increased H2O2 and IAA levels, flavin monooxygenase (FMO) activity, and respiratory burst oxidase homolog (RBOH1) and FMO-like protein (YUCCA2) mRNA levels in cucumber seedlings. DMTU, DPI, and NPA diminished NaHS-induced H2O2 production, but DMTU and DPI did not affect IAA levels induced by NaHS during chilling stress. Taken together, the present data indicate that H2O2 as a downstream signal of IAA mediates H2S-induced chilling tolerance in cucumber seedlings.

15.
Environ Sci Technol ; 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34859678

RESUMO

Endocrine-disrupting chemicals (EDCs) can inadvertently interact with 12 classic nuclear receptors (NRs) that disrupt the endocrine system and cause adverse effects. There is no widely accepted understanding about what structural features make thousands of EDCs able to activate different NRs as well as how these structural features exert their functions and induce different outcomes at the cellular level. This paper applies the hierarchical characteristic fragment methodology and high-throughput screening molecular docking to comprehensively explore the structural and functional features of EDCs for the 12 NRs based on more than 7000 chemicals from curated datasets. EDCs share three levels of key fragments. The primary and secondary fragments are associated with the binding of EDCs to four groups of receptors: steroidal nuclear receptors (SNRs, including androgen, estrogen, glucocorticoid, mineralocorticoid, and progesterone), retinoic acid receptors, thyroid hormone receptors, and vitamin D receptors. The tertiary fragments determine the activity type by interacting with two key locations in the ligand-binding domains of NRs (N-H5-H3-C and N-H7-H11-C for SNRs and N-H5-H5'-H2'-H3-C and N-H6'-H11-C for non-SNRs). The resulting compiled structural fragments of EDCs together with elucidated compound NR binding modes provide a framework for understanding the interactions between EDCs and NRs, facilitating faster and more accurate screening of EDCs for multiple NRs in the future.

16.
Environ Res ; 205: 112427, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34861229

RESUMO

Exposure to bisphenols chemicals could cause various adverse health effects, including non-alcoholic fatty liver disease (NAFLD), which have been associated with cellular mitochondria stress. However, the biological mechanism underlying the mitochondria stress-mediated cell death by bisphenols was poorly understood. Here, CRISPR screens were performed to identify the critical genes which were involved in cell death caused by exposure to four bisphenols (BPA, BPB, BPE and BPS). Results of CRISPR screens showed that UGT1A9 was the primary genetic factor facilitating cell death induced by all of the four bisphenols. Systematic toxicological tests demonstrated that UGT1A9 was required for BPA-induced mitochondria dyshomeostasis in vitro and in vivo, and UGT1A9-mediated mitochondria dyshomeostasis was an important cause of facilitating cell death. Liver injury caused by exposure to BPA in wild-type mice was accompanied with suppression of mitophagy and increased expression of C-Caspase 3, but UGT1A9 knockout attenuated these adverse effects induced by BPA. Finally, molecular epidemiology analysis suggested that the five genetic variants of UGT1A9 could be potential genetic risk factors of NAFLD when people were exposed to BPA. The biological mechanism uncovered here provided mechanistic evidence for identification of susceptible populations of liver injury associated with exposure to BPA.

17.
Artigo em Chinês | MEDLINE | ID: mdl-34886615

RESUMO

With the continuous updating of head and neck surgery concepts and techniques, more and more head and neck surgeries are developing in the direction of refinement.however, the more complete the surgery, the greater the possibility of subsequent nerve exposure and injury. Even a slight perturbation of the nerve may cause serious complications, such as pressure receptor failure.It is necessary to review the mechanisms and the characteristics of baroreceptor failure syndrome after head and neck tumor surgery.

18.
Front Plant Sci ; 12: 789617, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956288

RESUMO

Chilling adversely affects the photosynthesis of thermophilic plants, which further leads to a decline in growth and yield. The role of melatonin (MT) in the stress response of plants has been investigated, while the mechanisms by which MT regulates the chilling tolerance of chilling-sensitive cucumber remain unclear. This study demonstrated that MT positively regulated the chilling tolerance of cucumber seedlings and that 1.0 µmol⋅L-1 was the optimum concentration, of which the chilling injury index, electrolyte leakage (EL), and malondialdehyde (MDA) were the lowest, while growth was the highest among all treatments. MT triggered the activity and expression of antioxidant enzymes, which in turn decreased hydrogen peroxide (H2O2) and superoxide anion (O2 ⋅-) accumulation caused by chilling stress. Meanwhile, MT attenuated the chilling-induced decrease, in the net photosynthetic rate (Pn) and promoted photoprotection for both photosystem II (PSII) and photosystem I (PSI), regarding the higher maximum quantum efficiency of PSII (Fv/Fm), actual photochemical efficiency (ΦPSII), the content of active P700 (ΔI/I0), and photosynthetic electron transport. The proteome analysis and western blot data revealed that MT upregulated the protein levels of PSI reaction center subunits (PsaD, PsaE, PsaF, PsaH, and PsaN), PSII-associated protein PsbA (D1), and ribulose-1,5-bisphosphate carboxylase or oxygenase large subunit (RBCL) and Rubisco activase (RCA). These results suggest that MT enhances the chilling tolerance of cucumber through the activation of antioxidant enzymes and the induction of key PSI-, PSII-related and carbon assimilation genes, which finally alleviates damage to the photosynthetic apparatus and decreases oxidative damage to cucumber seedlings under chilling stress.

19.
Comput Biol Med ; 140: 105080, 2021 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-34902609

RESUMO

Emotion recognition is a vital but challenging step in creating passive brain-computer interface applications. In recent years, many studies on electroencephalogram (EEG)-based emotion recognition have been conducted. Ensemble learning has been widely used in emotion recognition because of its superior accuracy and generalization. In this study, we proposed a novel ensemble learning method based on multiple objective particle swarm optimization for subject-independent EEG-based emotion recognition. First, we used a 4 s sliding time window with a 2 s overlap to extract 13 different features from EEG signals and construct a feature vector. Then, we employed L1 regularization to select effective features. Second, a model selection method was applied to choose the optimal basic analysis submodels. Afterward, we proposed an ensemble operator that converts the classification results of a single model from discrete values to continuous values to better characterize the classification results. Subsequently, multiple objective particle swarm optimization was adopted to confirm the optimal parameters of the ensemble learning model. Finally, we conducted extensive experiments on two public datasets: DEAP and SEED. Considering the generalization of the model, we applied leave-one-subject-out cross-validation to evaluate the performance of the model. The experimental results demonstrate that the proposed method achieves a better recognition performance than single methods, commonly used ensemble learning methods, and state-of-the-art methods. The average accuracies for arousal and valence are 65.70% and 64.22%, respectively, on the DEAP database, and the average accuracy on the SEED database is 84.44%.

20.
Int J Mol Sci ; 22(24)2021 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-34948028

RESUMO

As an important gas signaling molecule, hydrogen sulfide (H2S) plays a crucial role in regulating cold tolerance. H2S cooperates with phytohormones such as abscisic acid, ethylene, and salicylic acid to regulate the plant stress response. However, the synergistic regulation of H2S and auxin in the plant response to cold stress has not been reported. This study showed that sodium hydrosulfide (NaHS, an H2S donor) treatment enhanced the cold stress tolerance of cucumber seedlings and increased the level of auxin. CsARF5, a cucumber auxin response factor (ARF) gene, was isolated, and its role in regulating H2S-mediated cold stress tolerance was described. Transgenic cucumber leaves overexpressing CsARF5 were obtained. Physiological analysis indicated that overexpression of CsARF5 enhanced the cold stress tolerance of cucumber and the regulation of the cold stress response by CsARF5 depends on H2S. In addition, molecular assays showed that CsARF5 modulated cold stress response by directly activating the expression of the dehydration-responsive element-binding (DREB)/C-repeat binding factor (CBF) gene CsDREB3, which was identified as a positive regulator of cold stress. Taken together, the above results suggest that CsARF5 plays an important role in H2S-mediated cold stress in cucumber. These results shed light on the molecular mechanism by which H2S regulates cold stress response by mediating auxin signaling; this will provide insights for further studies on the molecular mechanism by which H2S regulates cold stress. The aim of this study was to explore the molecular mechanism of H2S regulating cold tolerance of cucumber seedlings and provide a theoretical basis for the further study of cucumber cultivation and environmental adaptability technology in winter.

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