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1.
Neuroimage ; 297: 120692, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38897398

RESUMEN

Errors typically trigger post-error adjustments aimed at improving subsequent reactions within a single task, but little work has focused on whether these adjustments are task-general or task-specific across different tasks. We collected behavioral and electrophysiological (EEG) data when participants performed a psychological refractory period paradigm. This paradigm required them to complete Task 1 and Task 2 separated by a variable stimulus onset asynchrony (SOA). Behaviorally, post-error slowing and post-error accuracy exhibited task-general features at short SOAs but some task-specific features at long SOAs. EEG results manifest that task-general adjustments had a short-lived effect, whereas task-specific adjustments were long-lasting. Moreover, error awareness specifically conduced to the improvement of subsequent sensory processing and behavior performance in Task 1 (the task where errors occurred). These findings demonstrate that post-error adjustments rely on both transient, task-general interference and longer-lasting, task-specific control mechanisms simultaneously, with error awareness playing a crucial role in determining these mechanisms. We further discuss the contribution of central resources to the task specificity of post-error adjustments.

2.
Cereb Cortex ; 33(13): 8110-8121, 2023 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-36997156

RESUMEN

Empirical evidence on error processing comes from the comparison between errors and correct responses in general, but essential differences may exist between different error types. Typically, cognitive control tasks elicit errors without conflicts (congruent errors) and with conflicts (incongruent errors), which may employ different monitoring and adjustment mechanisms. However, the neural indicators that distinguish between both error types remain unclear. To solve this issue, behavioral and electrophysiological data were measured while subjects performed the flanker task. Results showed that a significant post-error improvement in accuracy on incongruent errors, but not on congruent errors. Theta and beta power were comparable between both error types. Importantly, the basic error-related alpha suppression (ERAS) effect was observed on both errors, whereas ERAS evoked by incongruent errors was greater than congruent errors, indicating that post-error attentional adjustments are both source-general and source-specific. And the brain activity in alpha band, but not theta or beta band, successfully decoded congruent and incongruent errors. Furthermore, improved post-incongruent error accuracy was predicted by a measure of post-error attentional adjustments, the alpha power. Together, these findings demonstrate that ERAS is a reliable neural indicator for identifying error types, and directly conduces to the improvement of post-error behavior.


Asunto(s)
Atención , Electroencefalografía , Humanos , Electroencefalografía/métodos , Atención/fisiología , Tiempo de Reacción/fisiología
3.
J Exp Bot ; 74(18): 5820-5839, 2023 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-37470327

RESUMEN

The gene networks surrounding Nod factor receptors that govern the symbiotic process between legumes and rhizobia remain largely unexplored. Here, we identify 13 novel GmNFR1α-associated proteins by yeast two-hybrid screening, and describe a potential interacting protein, GmBI-1α. GmBI-1α had the highest positive correlation with GmNFR1α in a co-expression network analysis, and its expression at the mRNA level in roots was enhanced by rhizobial infection. Moreover, GmBI-1α-GmNFR1α interaction was shown to occur in vitro and in vivo. The GmBI-1α protein was localized to multiple subcellular locations, including the endoplasmic reticulum and plasma membrane. Overexpression of GmBI-1α increased the nodule number in transgenic hairy roots or transgenic soybean, whereas down-regulation of GmBI-1α transcripts by RNA interference reduced the nodule number. In addition, the nodules in GmBI-1α-overexpressing plants became smaller in size and infected area with reduced nitrogenase activity. In GmBI-1α-overexpressing transgenic soybean, the elevated GmBI-1α also promoted plant growth and suppressed the expression of defense signaling-related genes. Infection thread analysis of GmBI-1α-overexpressing plants showed that GmBI-1α promoted rhizobial infection. Collectively, our findings support a GmNFR1α-associated protein in the Nod factor signaling pathway and shed new light on the regulatory mechanism of GmNFR1α in rhizobial symbiosis.


Asunto(s)
Fabaceae , Rhizobium , Simbiosis/genética , Fabaceae/metabolismo , Proteína X Asociada a bcl-2/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Glycine max/metabolismo , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/metabolismo , Nodulación de la Raíz de la Planta/genética
4.
Toxicol Appl Pharmacol ; 464: 116438, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-36841340

RESUMEN

The pathophysiological mechanism of hepatic fibrosis (HF) is related to the excessive activation of the DNA repair enzyme poly ADP-ribose polymerase-1 (PARP-1). The drugs, targeting PARP-1, are scarce. Therefore, the lead compound, moderately inhibiting PARP-1, with anti-HF properties should be identified. This study screened dihydrokaempferol (DHK) from herbs based on preliminary studies to intervene in a CCl4-induced liver injury and HF model in mice. In vitro, the expression levels of PARP-1-regulated related proteins and phosphorylation were examined. The binding pattern of DHK and PARP-1 was analyzed using molecular docking and molecular dynamics platforms. The results showed that DHK could significantly attenuate CCl4-induced liver injury and HF in mice. Moreover, it could also attenuate the toxic effects of CCl4 on HepG2 and inhibit α-SMA and Collagen 1/3 synthesis of LX-2 cells in-vitro. Molecular docking revealed that DHK could competitively bind to the Glu-988 and His-862 residues of the upstream DNA repair enzyme PARP-1, moderately inhibiting its overactivation. This led to maintaining NAD+ levels and energy metabolism in hepatocytes and inhibiting the activation of PARP-1-regulated downstream signaling pathways (TGF-ß1, etc.), related proteins (p-Smd2/3, etc.), and inflammatory mediators while acting indirectly. Thus, DHK could attenuate CCl4-induced liver injury and HF in mice in a different mechanism from those of the existing reported flavonoids. It was associated with inhibiting the expression of downstream pathways and related cytokines by competitively binding to PARP-1. This study might provide a basis and direction for the design and exploration of anti-HF lead compounds.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Citocinas , Animales , Ratones , Tetracloruro de Carbono/toxicidad , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/metabolismo , Enfermedad Hepática Crónica Inducida por Sustancias y Drogas/patología , Citocinas/metabolismo , Flavonoides/farmacología , Células Estrelladas Hepáticas , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/prevención & control , Simulación del Acoplamiento Molecular , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Factor de Crecimiento Transformador beta1/metabolismo
5.
Phys Chem Chem Phys ; 25(12): 8317-8330, 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36892566

RESUMEN

The adsorption of anions and its impact on electrocatalytic reactions are fundamental topics in electrocatalysis. Previous studies revealed that adsorbed anions display an overall poisoning effect in most cases. However, for a few reactions such as the hydrogen evolution reaction (HER), oxidation of small organic molecules (SOMs), and reduction of CO2 and O2, some specifically adsorbed anions can promote their reaction kinetics under certain conditions. The promotion effect is frequently attributed to the adsorbate induced modification of the nature of the active sites, the change of the adsorption configuration and free energy of the key reactive intermediate which consequently change the activation energy, the pre-exponential factor of the rate determining step etc. In this paper, we will give a mini review of the indispensable role of the classical double layer effect in enhancing the kinetics of electrocatalytic reactions by anion adsorption. The ubiquitous electrostatic interactions change both the potential distribution and the concentration distribution of ionic species across the electric double layer (EDL), which alters the electrochemical driving force and effective concentration of the reactants. The contribution to the overall kinetics is highlighted by taking HER, oxidation of SOMs, reduction of CO2 and O2, as examples.

6.
BMC Psychiatry ; 23(1): 54, 2023 01 19.
Artículo en Inglés | MEDLINE | ID: mdl-36658505

RESUMEN

OBJECTIVE: Subjective cognitive decline (SCD) is highlighted in patients with major depressive disorder (MDD), which impairs objective cognitive performance and worsens the clinical outcomes. Immune dysregulation is supposed to be the potential mechanism of cognitive impairment. However, the peripheral immune biomarkers in patients troubled with MDD and SCD are not conventionally described. METHODS: A prospective-observational study was conducted for 8 weeks. Subjective cognitive function was measured using the Chinese version of the 20-item perceived deficits questionnaire-depression (PDQ-D) and depression symptoms were evaluated with Hamilton Depression Rating Scale-17 (HDRS-17). Luminex assays were used to measure 48 immune cytokines in plasma at baseline. Integrating these results and clinicopathological features, a logistic regression model was used to develop a prognostic prediction. RESULTS: Totally, 114 patients were enrolled in this study. Among the patients who completed follow-up, 56% (N = 50) had residual subjective cognitive decline, and 44% (N = 50) did not. The plasma levels of FGF basic, INF-γ, IL-1ß, MCP-1, M-CSF and SCF were increased and the levels of IL-9, RANTES and PDGF-BB were decreased in the SCD group. Additionally, Basic FGF, IFN-γ, IL-1ß, and SCF were positively correlated and IL-9, RANTES, and PDGF-BB were negatively correlated with the PDQ-D scores after treatment. Notably, combinations of cytokines (SCF and PDGF-BB) and PDQ-D scores at baseline showed good performance (The area under the receiver operating characteristic curve = 0.818) in the prediction of subjective cognitive decline. CONCLUSION: A prognostic model based on protein concentrations of SCF, PDGF-BB, and scores of PDQ-D showed considerable accuracy in predicting residual subjective cognitive decline in depression.


Asunto(s)
Disfunción Cognitiva , Trastorno Depresivo Mayor , Humanos , Trastorno Depresivo Mayor/complicaciones , Trastorno Depresivo Mayor/diagnóstico , Trastorno Depresivo Mayor/psicología , Estudios Prospectivos , Pronóstico , Becaplermina , Interleucina-9 , Disfunción Cognitiva/diagnóstico , Disfunción Cognitiva/psicología , Biomarcadores , Citocinas
7.
Ecotoxicol Environ Saf ; 251: 114519, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36634478

RESUMEN

Blue light with a wavelength of 400-470 nm is the composition of the visible light. However, in recent years, blue light contributed the most significance to light pollution due to the artificial light at night. Previously, we have demonstrated that the Asian citrus psyllid (ACP), Diaphorina citri, an important pest in citrus production, has significant positive phototaxis with a light-emitting diode light of 400 nm. In this study, ACP with positive phototactic behavior to 400 nm light (PH) and non-phototactic behavior to 400 nm light (NP) were collected, individually. Transcriptome dynamics of head tissues of PH and NP groups were captured by using RNA-sequencing technology, respectively. Forty-three to 46 million clean reads with high-quality values were obtained, and 1773 differential expressed genes (DEGs) were detected. Compared with the NP group, there were 841 up-regulated DEGs and 932 down-regulated DEGs in the PH group. Eight pathways were significantly enriched in the PH group in the KEGG database, while 43 up-regulated pathways and 25 down-regulated pathways were significantly enriched in the PH group in the GO database. The DGE approach was reliable validated by real time quantitative PCR. Results indicated that the blue light acted as an abiotic stress causing physiological and biochemical responses such as oxidative stress, protein denaturation, inflammation and tumor development in ACPs. Additionally, the light was absorbed by photoreceptors of ACPs, and converted into electrical signal to regulate neuromodulation. This study provides basic information for understanding the molecular mechanisms of ACP in response to blue light and provides a reference for further studies to elucidate phototactic behavior.


Asunto(s)
Citrus , Hemípteros , Animales , Fototaxis , Hemípteros/genética , Hemípteros/metabolismo , Transcriptoma , Luz , Citrus/genética , Encéfalo
8.
Yi Chuan ; 45(8): 684-699, 2023 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-37609819

RESUMEN

Non-small cell lung cancer (NSCLC) is a highly morbid and fatal disease that exhibits individualized differences in prognosis and drug efficacy. Therefore, understanding the molecular mechanism of the occurrence and progression of lung cancer can improve early diagnosis, treatment and prognosis. Macrophages are a crucial component of the tumor microenvironment (TME) due to their high plasticity and heterogeneity. They play a multifaceted role in tumor initiation and progression. In order to elucidate the pathogenesis of tumor-associated macrophages (TAMs) related genes in NSCLC, transcriptomic sequencing, univariate COX regression, LASSO regression and multivariate COX regression analyses were conducted to identify the 11 genes that have the most significant association with prognosis. These genes include FCRLA, LDHA, LMOD3, MAP3K8, NT5E, PDGFB, S100P, SFXN1, TDRD1, TFAP2A and TUBB6. The risk score (RS) was computed, and all samples were split into high- and low-risk groups based on the median RS. The correlation of RS and 11 genes with macrophages was verified by the CIBERSORT deconvolution algorithm. These above results suggest that the risk score developed in this study can be utilized for predicting patients' prognosis and evaluating their immune infiltration status. This study can serve as a guide for subsequent tumor immunotherapy and gene targeting therapy.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Humanos , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/terapia , Microambiente Tumoral/genética , Pronóstico , Macrófagos
9.
Angew Chem Int Ed Engl ; 62(12): e202300209, 2023 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-36718610

RESUMEN

Interface fusion plays a key role in constructing Ni-based single-crystal cathodes, and is governed by the atomic migration related to kinetics. However, the interfacial atom migration path and its control factors are lack of clearly understanding. Herein, we systematically probe the solid-state synthesis mechanism of single-crystal LiNi0.92 Co0.04 Mn0.04 O2 , including the effects of precursor size, Li/transition metal (TM) ratio and sintering temperature on the structure. Multi-dimensional analysis unravels that thermodynamics drives interface atoms migration through intermediate state (i.e., cation mixing phase) to induce grain boundary fusion. Moreover, we demonstrate that smaller precursor size (<6 µm), lager Li/TM ratio (>1.0) and higher temperature (≥810 °C) are conducive to promote the growth of the intermediate state due to reaction kinetics enhancement, and ultimately strengthen the atomic migration-induced interface fusion.

10.
Arch Microbiol ; 205(1): 20, 2022 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-36482126

RESUMEN

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a zoonotic pathogen that causes severe gastroenteritis. The 5'-nucleotidases of pathogens can dephosphorylate adenosine phosphates, boost adenosine levels and suppress the pro-inflammatory immune response. In our previous study, an extracellular nuclease, 5'-nucleotidase, was identified in the extracellular proteins of S. Typhimurium. However, the nuclease activity and the function of the 5'-nucleotidase of S. Typhimurium have not been explored. In the present study, deletion of the 5'-nucleotidase gene is dispensable for S. Typhimurium growth, even under environmental stress. Fluorescence microscopy revealed that the 5'-nucleotidase mutant induced more macrophage extracellular traps (METs) than the wild type did. Furthermore, recombinant 5'-nucleotidase protein (r5Nuc) could degrade λDNA, and the nuclease activity of r5Nuc was optimum at 37 °C and pH 6.0-7.0. The Mg2+ enhanced the nuclease activity of r5Nuc, whereas Zn2+ inhibited it. Meanwhile, deletion of the 5'-nucleotidase gene increased the bactericidal activity of METs, and r5Nuc could degrade METs and inhibit the bactericidal activity of METs. In conclusion, S. Typhimurium growth was independent of 5'-nucleotidase, but the nuclease activity of 5'-nucleotidase assisted S. Typhimurium to evade macrophage-mediated extracellular killing through degrading METs.


Asunto(s)
Trampas Extracelulares , Salmonella typhimurium , Salmonella typhimurium/genética , Macrófagos
11.
Inorg Chem ; 61(12): 5033-5039, 2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35275637

RESUMEN

The simultaneous manipulation of the catalytic activity and intrinsic electrical conductivity in a unified system is difficult yet meaningful to unravel the possible strategy that can enhance the hydrogen evolution reaction (HER) performance. Therefore, we propose a simple strategy to enhance the HER performance based on low-temperature redox reaction with ZIF-67@ZIF-8 as a sacrificial template to prepare zinc-doped amorphous CoMo8Ox (denoted as Zn/aCMO). Benefiting from the excellent compositional- and amorphous-based structural advantages of more exposure active sites, optimized electron transfer as well as a stable frame structure, the as-prepared electrode can drive hydrogen evolution at current densities of 10, 50, and 100 mA cm-2, which need ultralow overpotentials of 59, 138, and 189 mV, respectively, and the Tafel slope of the electrode was 66.2 mV dec-1 (1 M KOH). Meanwhile, the intrinsic activity of the prepared low-cost electrocatalyst was also determined, and the turnover frequency was up to 1.49 s-1 at an overpotential of 100 mV. In addition, after continuous testing for 160 h, there was a slight decay at the overpotential of 130 mV.

12.
BMC Psychiatry ; 22(1): 802, 2022 12 19.
Artículo en Inglés | MEDLINE | ID: mdl-36536362

RESUMEN

BACKGROUND: Treatment-resistant depression (TRD) carries a high economic burden worldwide. Transcranial direct current stimulation (tDCS) is advantageous for improving cognition and can be safely used in the treatment of depression. The effectiveness of tDCS of the left and right orbitofrontal cortex (OFC) as adjuvant treatment in patients with TRD has rarely been explored. Therefore, the objective of this trial is to evaluate the effectiveness there of when administering left dorsolateral prefrontal cortex (DLPFC) positive stimulation or OFC negative stimulation in patients with TRD. METHODS: Ninety eligible participants will be recruited to receive intervention at Shanghai Mental Health Center. Treatment will be randomly assigned in a double-blind fashion. Participants will receive either DLPFC (n = 30), OFC (n = 30), or sham (n = 30) tDCS, while continuing their usual pharmacotherapy at a stable dosage for at least 2 weeks before enrollment and throughout the stimulation period. All participants will receive 20 weekday stimulation sessions of 60 minutes duration each. Participants in the active group will be stimulated at 2 mA throughout the session, whereas the sham group will receive only a brief period of stimulation to mimic the sensation. After 20 stimulation sessions, no further treatment will be administered. Measurements will be conducted at regular points throughout and at 8 weeks after trial completion. The primary outcome is the change in the 17-item Hamilton Depression Rating Scale (HAMD-17) score after 20 sessions. Secondary outcomes were defined as changes in other measurement scales, cognitive function, resting-state functional magnetic resonance imaging (rs-fMRI), and serum biomarkers. DISCUSSION: We hypothesize that, in contrast to the sham group, both the active DLPFC and OFC tDCS groups will show superiority in HAMD-17 score reduction after 5, 10, and 20 sessions. Moreover, associations of the improvement of depressive symptoms with variations in rs-fMRI and TRD-related biomarkers will be evaluated. Our study may suggest that adjunctive intensive tDCS with left DLPFC positive stimulation or right OFC negative stimulation may be effective as a novel method to relieve depressive symptoms in patients with TRD. The variation of rs-fMRI, biomarkers could be used as a potential prediction model of treatment efficacy in TRD. TRIAL REGISTRATION: The trial protocol is registered with www.chictr.org.cn under protocol registration number ChiCTR2200058030. Date of registration: March 27, 2022. Recruitment started in September 2022 and is ongoing.


Asunto(s)
Estimulación Transcraneal de Corriente Directa , Humanos , Estimulación Transcraneal de Corriente Directa/métodos , Corteza Prefrontal/fisiología , Depresión , China , Lóbulo Frontal , Método Doble Ciego , Resultado del Tratamiento , Ensayos Clínicos Controlados Aleatorios como Asunto
13.
J Thromb Thrombolysis ; 53(4): 911-925, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-34985685

RESUMEN

None of studies are available on the predictive ability of white matter lesions (WMLs) among patent foramen ovale (PFO), atherosclerotic cerebral small vessel disease (aCSVD) and cerebral venous thrombosis (CVT). Herein, we aimed to uncover the difference of the WML patterns among the three disease entities in a real-world setting to provide clinical references for predicting probable WML etiologies. We retrospectively reviewed data from consecutive patients with imaging-confirmed PFO, aCSVD, or CVT enrolled from 2014 through 2020. WMLs presented on fluid-attenuated inversion recovery (FLAIR) maps were compared among the three groups based on visual evaluation, Fazekas and modified Scheltens scales. Propensity score matching (PSM) was implemented to correct age and hypertension differences among groups. A total of 401 patients were entered into final analysis, including PFO (n = 112, 46.5 ± 12.8 years), aCSVD (n = 177, 61.6 ± 11.8 years) and CVT (n = 112, 37.4 ± 11.4 years) groups. In this study, WMLs occurred in all of the involved patients in the three groups (100%), which were independent to age, symptom onset and disease durations. On visual evaluation, PFO-WMLs were multiple spots distributed asymmetrically around bilateral subcortex and peri-ventricles. aCSVD-WMLs were dots or sheets distributed symmetrically in subcortex and peri-ventricles, and often coexisted with lacunar infarctions. CVT-WMLs were cloud-like around bilateral peri-ventricles, and enabled to attenuate after recanalization. Fazekas and modified Scheltens scores of PFO-WML vs. aCSVD-WML were significantly different even after being matched by 1:2 PSM (all p < 0.05), meaning that the WML burden in aCSVD was considerably heavier than that in PFO. WML patterns induced by PFO, aCSVD and CVT were obviously different, and were therefore of great clinical significance to preliminarily predict and differentiate the three diseases entities.


Asunto(s)
Enfermedades de los Pequeños Vasos Cerebrales , Foramen Oval Permeable , Trombosis Intracraneal , Trombosis de la Vena , Sustancia Blanca , Encéfalo , Enfermedades de los Pequeños Vasos Cerebrales/patología , Foramen Oval Permeable/complicaciones , Foramen Oval Permeable/diagnóstico por imagen , Humanos , Estudios Retrospectivos , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/patología , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología
14.
Int J Mol Sci ; 23(16)2022 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-36012283

RESUMEN

Remarkable advancements have been achieved in the development of rapid analytic techniques toward fumonisin B1 (FB1) monitoring and even trace levels for food safety in recent years. However, the point-of-care testing for quantitative and accurate FB1 determination is still challenging. Herein, an innovative aptasensor was established to monitor FB1 by utilizing graphene oxide (GO) and nuclease-triggered signal enhancement. GO can be utilized as a fluorescence quenching agent toward a fluorophore-modified aptamer, and even as a protectant of the aptamer from nuclease cleavage for subsequent target cycling and signal amplification detection. This proposed sensing strategy exhibited a good linearity for FB1 determination in the dynamic range from 0.5 to 20 ng mL-1 with a good correlation of R2 = 0.995. Its limit of detection was established at 0.15 ng mL-1 (S/N = 3), which was significantly lower than the legal requirements by three orders of magnitude. The interferent study demonstrated that the introduced aptasensor possessed high selectivity for FB1. Moreover, the aptasensor was successfully applied to the detection of wheat flour samples, and the results were consistent with the classical ELISA method. The rapid response, sensitive and selective analysis, and reliable results of this sensing platform offer a promising opportunity for food mycotoxin control in point-of-care testing.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Grafito , Técnicas Biosensibles/métodos , Harina , Fumonisinas , Límite de Detección , Triticum
15.
Anal Chem ; 93(4): 1976-1983, 2021 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-33395265

RESUMEN

In mild acidic or alkaline solutions with limited buffer capacity, the pH at the electrode/electrolyte interface (pHs) may change significantly when the supply of H+ (or OH-) is slower than its consumption or production by the electrode reaction. Buffer pairs are usually applied to resist the change of pHs during the electrochemical reaction. In this work, by taking H2X ⇄ 2H+ + X + 2e- under a rotating disk electrode configuration as a model reaction, numerical simulations are carried out to figure out how pHs changes with the reaction rate in solutions of different bulk pHs (pHb in the range from 0 to 14) and in the presence of buffer pairs with different pKa values and concentrations. The quantitative relation of pHs, pHb, pKa, and concentration of buffer pairs as well as of the reaction current density is established. Diagrams of pHs and ΔpH (ΔpH = pHs - pHb) as a function of pHb and the reaction current density as well as of the jmax-pHb plots are provided, where jmax is defined as the maximum allowable current density within the acceptable tolerance of deviation of pHs from that of pHb (e.g., ΔpH < 0.2). The j-pHs diagrams allow one to estimate the pHs and ΔpH without direct measurement. The jmax-pHb plots may serve as a guideline for choosing buffer pairs with appropriate pKa and concentration to mitigate the pHs shift induced by electrode reactions.

16.
J Antimicrob Chemother ; 76(12): 3168-3174, 2021 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-34499729

RESUMEN

BACKGROUND: The increasing use of colistin causes a serious breach in our last line of defence against MDR Gram-negative pathogens. Our previous study showed that CpxR overexpression increases the susceptibility of acrB and cpxR double-deleted Salmonella enterica serovar Typhimurium to colistin. OBJECTIVES: To identify the mechanism of CpxAR and efflux pumps that synergistically enhance the susceptibility of S. Typhimurium to colistin. METHODS: A series of cpxR- and tolC-deleted mutants and a cpxR-complemented strain from a multidrug-susceptible standard strain of S. Typhimurium (JS) were generated in our previous study. Herein, we investigated the susceptibility of these strains to colistin through the broth microdilution method, time-kill curves and survival assays. Growth curves were measured by OD600 in LB broth, tryptone-soy broth (TSB) and M9-glucose (0.2%) minimal media. Finally, molecular mechanisms underlying the mode of action were elucidated by transcriptomic analysis. RESULTS: We found that in contrast to JS (0.8 mg/L), the MIC of colistin for JSΔtolC::kan showed a 16-fold decrease (0.05 mg/L). Notably, JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were associated with a 256-fold decrease (0.0031 mg/L) compared with JS. Growth curves identified that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR displayed a markedly lower growth rate and poorer adaptability. In addition, time-kill curves and survival assays showed that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were more susceptible to colistin. Lastly, double deletion of cpxR and tolC enhanced oxidative damage through promoting oxidative phosphorylation, the tricarboxylic acid (TCA) cycle and trimethylamine N-oxide (TMAO) respiration. CONCLUSIONS: Our findings revealed that double deletion of cpxR and tolC significantly increases the susceptibility of S. Typhimurium to colistin.


Asunto(s)
Colistina , Salmonella typhimurium , Antibacterianos/farmacología , Proteínas Bacterianas/genética , Colistina/farmacología , Proteínas de Transporte de Membrana/genética , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Serogrupo
17.
J Basic Microbiol ; 61(8): 736-744, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34252217

RESUMEN

Primordia formation is the first and most critical step in the development of fruiting bodies of edible fungi. In this study, the effects of exogenous ascorbic acid (ASA) on the Pleurotus ostreatus mycelia growth and primordia formation were researched and the results showed that the growth rate of P. ostreatus mycelia was accelerated and the time of primordia formation was advanced. The protein content and ascorbate oxidase (AAO) activity analysis showed that with the increase of ASA concentration, the protein content of mycelia first decreased and then increased, and in a certain concentration range, exogenous ASA could significantly promote the activity of AAO. Further expression analysis of the development regulating genes (Pofst3 and Pofst4) as well as blue light receptor coding genes (PoWC-1 and PoWC-2) showed the expression levels of those four genes all changed after the exogenous ASA addition, which indicated that the expression changes of PoWC-1 and PoWC-2, two key genes in the light morphogenesis, might affect the expression levels of development regulating genes Pofst3 and Pofst4, so as to lead to the formation of primordia in advance.


Asunto(s)
Ácido Ascórbico/farmacología , Micelio/efectos de los fármacos , Micelio/crecimiento & desarrollo , Pleurotus/efectos de los fármacos , Pleurotus/crecimiento & desarrollo , Ascorbato Oxidasa , Ácido Ascórbico/metabolismo , Cuerpos Fructíferos de los Hongos/crecimiento & desarrollo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Regulación Fúngica de la Expresión Génica/efectos de los fármacos , Micelio/genética , Micelio/metabolismo , Pleurotus/genética , Pleurotus/metabolismo
18.
Int J Mol Sci ; 22(22)2021 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-34830230

RESUMEN

Phosphorus (P) is an essential macronutrient for plant growth and development. Among adaptive strategies of plants to P deficiency, increased anthocyanin accumulation is widely observed in plants, which is tightly regulated by a set of genes at transcription levels. However, it remains unclear whether other key regulators might control anthocyanin synthesis through protein modification under P-deficient conditions. In the study, phosphate (Pi) starvation led to anthocyanin accumulations in soybean (Glycine max) leaves, accompanied with increased transcripts of a group of genes involved in anthocyanin synthesis. Meanwhile, transcripts of GmCSN5A/B, two members of the COP9 signalosome subunit 5 (CSN5) family, were up-regulated in both young and old soybean leaves by Pi starvation. Furthermore, overexpressing GmCSN5A and GmCSN5B in Arabidopsis thaliana significantly resulted in anthocyanin accumulations in shoots, accompanied with increased transcripts of gene functions in anthocyanin synthesis including AtPAL, AtCHS, AtF3H, AtF3'H, AtDFR, AtANS, and AtUF3GT only under P-deficient conditions. Taken together, these results strongly suggest that P deficiency leads to increased anthocyanin synthesis through enhancing expression levels of genes involved in anthocyanin synthesis, which could be regulated by GmCSN5A and GmCSN5B.


Asunto(s)
Antocianinas/biosíntesis , Proteínas de Arabidopsis/genética , Arabidopsis/efectos de los fármacos , Complejo del Señalosoma COP9/genética , Regulación de la Expresión Génica de las Plantas , Glycine max/efectos de los fármacos , Fósforo/farmacología , Hojas de la Planta/efectos de los fármacos , Aciltransferasas/genética , Aciltransferasas/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Complejo del Señalosoma COP9/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Prueba de Complementación Genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Redes y Vías Metabólicas/efectos de los fármacos , Redes y Vías Metabólicas/genética , Fósforo/deficiencia , Hojas de la Planta/genética , Hojas de la Planta/metabolismo , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/genética , Brotes de la Planta/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Glycine max/genética , Glycine max/metabolismo , Transgenes
19.
Curr Microbiol ; 77(11): 3651-3660, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32939640

RESUMEN

Pathogens have evolved an array of strategies to establish a productive infection. The extracellular proteins secreted by pathogens are one of unique mechanisms to evade the host innate immune response. Many secretory proteins transported by the bacterial secretion systems have been widely investigated in Salmonella. Certain extracellular nucleases are essential for bacterial pathogenesis. However, there is no current data available for the enzymatic properties of the proteins secreted by Salmonella. Therefore, in the present study we have identified and characterized the nuclease activity of the extracellular proteins from Salmonella enterica serovar Typhimurium. It was demonstrated that the extracellular proteins from S. Typhimurium exhibited the deoxyribonucleases activity against λDNA by agarose gel electrophoresis and agar plate diffusion method. The activity was observed at 16 °C, 37 °C and 42 °C, and found to be highest at 42 °C and inhibited at temperatures over 60 °C. The nuclease activity was stable under alkaline conditions (pH 7-10) and the optimum pH was 9.0. The nuclease activity was promoted at high ionic strength of Ba2+, Ca2+, Mg2+, and Ni2+. Nuclease zymography analysis revealed that there were four activity bands in the extracellular proteins; followed by LC-ESI/MS/MS analysis seven proteins were identified. As demonstrated by nuclease zymography, the recombinant 5'-nucleotidase protein expressed in the prokaryotic expression system displayed the DNase activity. To our knowledge, the present findings represent the first direct and unambiguous demonstration of the nuclease activity of the extracellular proteins from S. Typhimurium, and it provides an important fundamental for further investigation of the role of the extracellular proteins in pathogenicity and immune evasion.


Asunto(s)
Salmonella typhimurium , Espectrometría de Masas en Tándem , Proteínas Bacterianas/genética , Salmonella typhimurium/genética , Serogrupo , Virulencia
20.
J Ultrasound Med ; 39(2): 361-371, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31432552

RESUMEN

OBJECTIVES: We aimed to develop radiomics with attribute bagging, which leverages multimodal ultrasound (US) images to improve the classification accuracy of breast tumors. METHODS: A retrospective study was conducted. B-mode US, shear wave elastographic, and contrast-enhanced US images of 178 patients with 181 tumors (67 malignant and 114 benign) were included. Radiomics with attribute bagging consisted of extraction of 1226 radiomic features and analysis of them with attribute bagging. Histologic examination results acted as the reference standard. Radiomics with several feature selection algorithms were used for comparison. Cross-validation and a holdout test were performed to evaluate their performances. RESULTS: The accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve of radiomics with attribute bagging with the multimodal US images were 84.12%, 92.86%, 78.80%, and 0.919, respectively, exceeding all the comparison methods. CONCLUSIONS: Radiomics with attribute bagging combined with multimodal US images has the potential to be used for accurate diagnosis of breast tumors in the clinic.


Asunto(s)
Algoritmos , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/patología , Diagnóstico por Imagen de Elasticidad/métodos , Ultrasonografía Mamaria/métodos , Adulto , Anciano , Medios de Contraste , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Sensibilidad y Especificidad , Máquina de Vectores de Soporte
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