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1.
J Immunol ; 2021 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-33941659

RESUMO

The detection of intracellular nucleic acids is a fundamental mechanism of host defense against infections. The dysregulated nucleic acid sensing, however, is a major cause for a number of autoimmune diseases. In this study, we report that GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) is critical for both intracellular DNA- and RNA-induced immune responses. We found that in both human and mouse cells, the deletion of G3BP1 led to the dampened cGAS activation by DNA and the insufficient binding of RNA by RIG-I. We further found that resveratrol (RSVL), a natural compound found in grape skin, suppressed both intracellular DNA- and RNA-induced type I IFN production through inhibiting G3BP1. Importantly, using experimental mouse models for Aicardi-Goutières syndrome, an autoimmune disorder found in humans, we demonstrated that RSVL effectively alleviated intracellular nucleic acid-stimulated autoimmune responses. Thus, our study demonstrated a broader role of G3BP1 in sensing different kinds of intracellular nucleic acids and presented RSVL as a potential treatment for autoimmune conditions caused by dysregulated nucleic acid sensing.

2.
Brain Cogn ; 150: 105731, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33866054

RESUMO

Despite the dynamic property of consciousness, little research has explored the characteristic of the effort in trying to focus back, in which attention is shifted from mind wandering to ongoing activities. In the current study, we assessed the frequency of daily mind wandering, the pleasantness of daily mind wandering content, and the daily focus back effort of 69 participants, and then collected their resting-state functional magnetic resonance imaging (rsfMRI) scans. Our results revealed that (1) participants who experienced more daily pleasant mind wandering tended to have higher effort in trying to focus back than individuals with less pleasant mind wandering whereas there were no significant relations between pleasantness of mind wandering and mind wandering frequency or between focus back effort and mind wandering frequency in everyday life; (2) the pleasantness of mind wandering and focus back effort were associated with two functional connectivity that related to focus back episodes (right dorsolateral prefrontal cortex-right middle frontal gyrus, right inferior parietal - right middle frontal gyrus). The nodes forming these functional connections belonged to the executive network. Taken together, these findings support the content regulation hypothesis that humans maintain their minds wandering away from unpleasant topics by engaging in executive control processes.

3.
Nat Commun ; 12(1): 2114, 2021 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-33837182

RESUMO

Lack of detailed knowledge of SARS-CoV-2 infection has been hampering the development of treatments for coronavirus disease 2019 (COVID-19). Here, we report that RNA triggers the liquid-liquid phase separation (LLPS) of the SARS-CoV-2 nucleocapsid protein, N. By analyzing all 29 proteins of SARS-CoV-2, we find that only N is predicted as an LLPS protein. We further confirm the LLPS of N during SARS-CoV-2 infection. Among the 100,849 genome variants of SARS-CoV-2 in the GISAID database, we identify that ~37% (36,941) of the genomes contain a specific trio-nucleotide polymorphism (GGG-to-AAC) in the coding sequence of N, which leads to the amino acid substitutions, R203K/G204R. Interestingly, NR203K/G204R exhibits a higher propensity to undergo LLPS and a greater effect on IFN inhibition. By screening the chemicals known to interfere with N-RNA binding in other viruses, we find that (-)-gallocatechin gallate (GCG), a polyphenol from green tea, disrupts the LLPS of N and inhibits SARS-CoV-2 replication. Thus, our study reveals that targeting N-RNA condensation with GCG could be a potential treatment for COVID-19.


Assuntos
Substituição de Aminoácidos/efeitos dos fármacos , Catequina/análogos & derivados , Proteínas do Nucleocapsídeo/genética , Replicação Viral/efeitos dos fármacos , /virologia , Catequina/farmacologia , Genoma Viral/genética , Humanos , Extração Líquido-Líquido , Proteínas do Nucleocapsídeo/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Replicação Viral/genética
4.
PLoS One ; 16(3): e0248555, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33720952

RESUMO

The relationships between negative emotions and smartphone addiction has been tested through the literature. However, most of the studies applied variable-centered approaches. The heterogeneity of smartphone addiction severity has not been examined for the associations with negative emotion variables. The purposes of the present study is to explore the latent classes of smartphone addiction and analyze the relationships between depression, social anxiety and boredom and these subgroups. The Smartphone Addiction Scale-Short Version (SAS-SV) and three negative emotion scales were employed to conduct a survey of 539 college students. Mplus8.3 software was applied to perform the latent class analysis (LCA) based on the smartphone addiction symptom ratings. ANOVA and multinomial logistic regression were used to explore the differences among these latent categories and the associations between these subgroups and negative emotion variables. Results demonstrated that Negative emotional variables were significantly correlated with smartphone addiction proneness. Based on their scores on the Smartphone Addiction Scale, smartphone users were divided into three latent classes: low risk class, moderate class and high risk class. Women were more likely to be classified in the high-risk class. The severity of depression and boredom was able to predict the membership of the latent class effectively; while social anxiety failed to do this in the high risk class.

5.
Artigo em Inglês | MEDLINE | ID: mdl-33753301

RESUMO

OBJECTIVE: The anatomic distribution of lower extremity deep venous thrombosis (LEDVT) plays an important role in its prevention and treatment. This study aimed to evaluate the anatomic distribution of hospital-acquired LEDVT (HA-LEDVT) and its probable role in the occurrence of pulmonary embolism (PE). METHODS: We retrospectively analyzed the demographic data, ultrasound results, and PE-related findings of inpatients with HA-LEDVT in 28 clinical departments at Peking University People's Hospital between January 1, 2007, and December 31, 2018. RESULTS: This study included 1431 HA-LEDVT events: 35.8%, 31%, and 33.3% were left, right, and bilateral LEDVT. Isolated distal, proximal, and blended DVT were detected in 83.4%, 7.3%, and 9.3% of the patients, respectively. The distribution of HA-LEDVT in the left and right lower extremities were not significantly different except in patients aged ≥40 years (left: 2.07 vs right: 1.88 per 1000 extremities, P = .04). For anatomic types of HA-LEDVT, isolated distal HA-LEDVT was 5.02 times more prevalent than proximal HA-LEDVT (1.24 vs 0.26 per 1000 extremities, P < .01). The involvement rates of specific deep veins by HA-LEDVT were highest in the muscular calf vein (87.5%) followed by the popliteal vein (10.1%), superficial femoral vein (9.3%), and common femoral vein (9.2%). HA-LEDVT involving multiple vein segments simultaneously occurred in 338 extremities. HA-LEDVT involving the muscular calf vein and at least one of three connected axial veins of the muscular calf vein occurred most frequently. Eighty-eight patients with HA-LEDVT (6.15%) had PE. The frequency of PE among patients with proximal and distal DVT (7.89% vs 6.23% P = .275) was not significantly different. The incidence of PE was highest in patients with bilateral proximal DVT (15.4%) and lowest in patients with a single right distal DVT (4.5%). PE occurred in 6% of muscular calf vein HA-LEDVT. In isolated muscular calf vein DVT cases, PE were more likely to occur in cases with a >6.05-mm-diameter thrombus than in those with a <6.05-mm-diameter thrombus (10.3% vs 4.2%, P ï¼œ .0001). CONCLUSIONS: HA-LEDVT is characterized by a significantly high percentage of DVT in the muscular calf vein. Muscular calf vein thrombosis may be the primary origin of lower extremity deep vein thrombosis. The diameter of the thrombus in the muscular calf vein may be associated with the occurrence of PE. More prospective studies are needed to more fully determine the natural history of HA-LEDVT and develop prevention and treatment guidelines for HA-LEDVT.

6.
J Neuromuscul Dis ; 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33646171

RESUMO

BACKGROUND: Ryanodine receptor 1-related myopathy (RYR1-RM) can present with a selective pattern and gradient of intramuscular fatty infiltration (IMFI) on magnetic resonance imaging (MRI). OBJECTIVE: To demonstrate an automated protocol for quantification of IMFI in the lower extremity muscles of individuals with RYR1-RM using T1-weighted MRI and to examine the relationships of IMFI with motor function and clinical severity. METHODS: Axial images of the lower extremity muscles were acquired by T1-weighted fast spin-echo and short tau inversion recovery (STIR) sequences. A modified ImageJ-based program was used for quantification. IMFI data was analyzed by mode of inheritance, motor function, and clinical severity. RESULTS: Upper and lower leg IMFI from 36 genetically confirmed and ambulatory RYR1-RM affected individuals (26 dominant and 10 recessive) were analyzed using Grey-scale quantification. There was no statistically significant difference in IMFI between dominant and recessive cases in upper or lower legs. IMFI in both upper and lower legs was inversely correlated with participant performance on the motor function measure (MFM-32) total score (upper leg: p <  0.001; lower leg: p = 0.003) and the six-minute walk test (6MWT) distance (upper leg: p <  0.001; lower leg: p = 0.010). There was no significant difference in mean IMFI between participants with mild versus severe clinical phenotypes (p = 0.257). CONCLUSION: A modified ImageJ-based algorithm was able to select and quantify fatty infiltration in a cohort of heterogeneously affected individuals with RYR1-RM. IMFI was not predictive of mode of inheritance but showed strong correlation with motor function and capacity tests including MFM-32 and 6MWT, respectively.

7.
Artigo em Inglês | MEDLINE | ID: mdl-33557516

RESUMO

Bimetallic organic frameworks (Bi-MOFs) have been recognized as one of the most ideal precursors to construct metal oxide semiconductor (MOS) composites, owing to their high surface area, various chemical structures, and easy removal of the sacrificial MOF scaffolds through calcination. Herein, we synthesized Zn/Ni Bi-MOF for the first time via a facile ion exchange postsynthetic strategy, formed a three-dimensional framework consisting of infinite one-dimensional chains that is unattainable through the direct solvothermal approach, and then transformed the Zn/Ni Bi-MOF into a unique ZnO/NiO heterostructure through calcination. Notably, the obtained sensor based on a ZnO/NiO heterostructure exhibits an ultrahigh response of 280.2 toward 500 ppm n-propanol at 275 °C (17.2-fold enhancement compared with that of ZnO), remarkable selectivity, and a limit of detection of 200 ppb with a notable response (2.51), which outperforms state-of-the-art n-propanol sensors. The enhanced n-propanol sensing properties may be attributed to the synergistic effects of several points including the heterojunction at the interface between the NiO and ZnO nanoparticles, especially a one-dimensional chain MOF template structure as well as the chemical sensitization effect of NiO. This work provides a promising strategy for the development of a novel Bi-MOF-derived MOS heterostructure or homostructure with well-defined morphology and composition that can be applied to the fields of gas sensing, energy storage, and catalysis.

8.
Ann Palliat Med ; 10(1): 672-680, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33545796

RESUMO

BACKGROUND: The novel 2019 coronavirus (COVID-19) has largely abated in China; however, sporadic or imported cases are still a concern, while in other countries, the COVID-19 pandemic persists as a major health crisis. METHODS: All patients enrolled in this study were diagnosed with COVID-19 from February 21, 2020 to April 14, 2020 in Wuhan. We retrospectively analyzed the patients admitted to the ICU (137 patients) and general wards (114 patients) of Wuhan Leishenshan Hospital in China. The population characteristics, symptoms, and laboratory examination results between the patients in the ICU and those in the general wards were compared. Furthermore, the differences between the deceased patients in the ICU and those discharged from the ICU were compared. RESULTS: There were significant differences between the two groups in terms of symptoms, including fever, shortness of breath, no presence of complications, presence of 1 complication, and presence of 3 or more complications (P<0.05). There were also significant differences between the patients in terms of the laboratory examination results including elevated urea nitrogen, creatinine, direct bilirubin, aspartate aminotransferase, total protein, albumin, creatine kinase, lactate dehydrogenase, procalcitonin, erythrocyte sedimentation rate, white blood cells, C-reactive protein, prothrombin time, activated partial thromboplastin time, fibrinogen, D-dimer, interleukin 6, interleukin 8, interleukin 10, interleukin 2 receptor, tumor necrosis factor-α, troponin I, phosphokinase isoenzyme-MB, and B-type natriuretic peptide; and decreased platelets, lymphocyte absolute value, and eosinophil absolute value (<0.05). There were 45 patients who died in ICU and 57 improved and discharged patients. There were significant differences between the two groups in the number of patients that had 1 complication and 3 or more complications (P<0.05). There were also significant differences in the laboratory examination results between the patients including elevated urea nitrogen, total bilirubin, direct bilirubin, aspartate aminotransferase, procalcitonin, white blood cells, interleukin 8, interleukin 10, phosphokinase isoenzyme-MB, and B-type natriuretic peptide; and decreased platelets and eosinophil absolute value (P<0.05). CONCLUSIONS: Our findings highlight that the identified determinants may help to improve treatment of COVID-19 patients, to predict the risk of developing severe illness and to optimizing arrangement of health resources.


Assuntos
/sangue , Hospitalização , Unidades de Terapia Intensiva , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Aspartato Aminotransferases/sangue , Bilirrubina/sangue , Contagem de Células Sanguíneas , Testes de Coagulação Sanguínea , Proteínas Sanguíneas/análise , Sedimentação Sanguínea , Nitrogênio da Ureia Sanguínea , Creatina Quinase/sangue , Creatinina/análise , Citocinas/sangue , Feminino , Febre/virologia , Humanos , L-Lactato Desidrogenase/sangue , Masculino , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Pró-Calcitonina/sangue , Estudos Retrospectivos , Adulto Jovem
9.
Fitoterapia ; 151: 104860, 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33582265

RESUMO

Glycyrrhizic acid, the main active ingredient of licorice, has good antibacterial, anti-tumor, anti-viral, anti-inflammatory, and immunostimulatory activities. However, the content of glycyrrhizic acid fluctuates greatly in different licorice cultivars, and production depends on plant sources, which greatly limits its development and applications. Therefore, increasing glycyrrhizic acid content has become a research priority. In recent years, regulation of the glycyrrhizic acid biosynthesis pathway has been analyzed, the downstream synthesis pathway in licorice has been fully investigated, some key genes have been cloned, polymorphisms have been studied, and the content of glycyrrhizic acid was shown to be regulated by environmental stimuli. This work has provided a basis for studying the regulation mechanism of the glycyrrhizic acid synthesis pathway. This review summarizes and discusses relevant research to provide a current understanding of the glycyrrhizic acid synthesis pathway and its regulation in licorice.

10.
J Cell Biol ; 220(2)2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33475699

RESUMO

Primary cilia protrude from the cell surface and have diverse roles during development and disease, which depends on the precise timing and control of cilia assembly and disassembly. Inactivation of assembly often causes cilia defects and underlies ciliopathy, while diseases caused by dysfunction in disassembly remain largely unknown. Here, we demonstrate that CEP55 functions as a cilia disassembly regulator to participate in ciliopathy. Cep55-/- mice display clinical manifestations of Meckel-Gruber syndrome, including perinatal death, polycystic kidneys, and abnormalities in the CNS. Interestingly, Cep55-/- mice exhibit an abnormal elongation of cilia on these tissues. Mechanistically, CEP55 promotes cilia disassembly by interacting with and stabilizing Aurora A kinase, which is achieved through facilitating the chaperonin CCT complex to Aurora A. In addition, CEP55 mutation in Meckel-Gruber syndrome causes the failure of cilia disassembly. Thus, our study establishes a cilia disassembly role for CEP55 in vivo, coupling defects in cilia disassembly to ciliopathy and further suggesting that proper cilia dynamics are critical for mammalian development.

11.
Nat Commun ; 12(1): 662, 2021 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-33510165

RESUMO

Dynamic assembly and disassembly of primary cilia controls embryonic development and tissue homeostasis. Dysregulation of ciliogenesis causes human developmental diseases termed ciliopathies. Cell-intrinsic regulatory mechanisms of cilia disassembly have been well-studied. The extracellular cues controlling cilia disassembly remain elusive, however. Here, we show that lysophosphatidic acid (LPA), a multifunctional bioactive phospholipid, acts as a physiological extracellular factor to initiate cilia disassembly and promote neurogenesis. Through systematic analysis of serum components, we identify a small molecular-LPA as the major driver of cilia disassembly. Genetic inactivation and pharmacological inhibition of LPA receptor 1 (LPAR1) abrogate cilia disassembly triggered by serum. The LPA-LPAR-G-protein pathway promotes the transcription and phosphorylation of cilia disassembly factors-Aurora A, through activating the transcription coactivators YAP/TAZ and calcium/CaM pathway, respectively. Deletion of Lpar1 in mice causes abnormally elongated cilia and decreased proliferation in neural progenitor cells, thereby resulting in defective neurogenesis. Collectively, our findings establish LPA as a physiological initiator of cilia disassembly and suggest targeting the metabolism of LPA and the LPA pathway as potential therapies for diseases with dysfunctional ciliogenesis.


Assuntos
Cílios/efeitos dos fármacos , Lisofosfolipídeos/farmacologia , Neurogênese/efeitos dos fármacos , Epitélio Pigmentado da Retina/efeitos dos fármacos , Transdução de Sinais , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cílios/genética , Cílios/metabolismo , Células HEK293 , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Humanos , Lisofosfolipídeos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células-Tronco Neurais/citologia , Células-Tronco Neurais/efeitos dos fármacos , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Ligação Proteica , Interferência de RNA , Receptores de Ácidos Lisofosfatídicos/genética , Receptores de Ácidos Lisofosfatídicos/metabolismo , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismo
12.
Psychophysiology ; : e13726, 2020 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-33278041

RESUMO

Surface features are an important component in attentive tracking. However, the neural mechanisms underlying how features affect attentive tracking remain unknown. The present fMRI study addressed this issue by manipulating the intragroup feature complexity and intergroup feature similarity. In particular, this study distinguished the different neural mechanisms of intragroup feature complexity and intergroup feature similarity by investigating the roles of attentional control and working memory in dynamic feature-based attentive tracking. Behavioral and neuroimaging evidence showed that when targets are distinct from distractors, the intragroup feature complexity of the targets, rather than that of the distractors, mainly increases the visual working memory load and significantly activates the frontoparietal cortical circuit. Thus, the involvement of working memory in feature-based attentive tracking is modulated by goal-directed attention control. In addition, when targets are similar to distractors, the intergroup feature similarity (i.e., target-distractor similarity) mainly affects the allocation of attention. Specifically, target-distractor similarity affects the goal-directed attention toward the targets in a stimulus-driven way and induces an interaction between the ventral and dorsal attention networks.

13.
ACS Omega ; 5(46): 29882-29888, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33251423

RESUMO

The geological structure and gas hydrate occurrence are stratification-dependent in the vertical direction. It is necessary to explore the formation processes and distribution characteristics of methane hydrate in layered porous media. The sand sample consists of two equal parts in a testing cylinder. The upper part is 0.5-1 mm sand in particle diameter, and the lower parts are 0.075∼0.5, 0.5∼1, and 1∼2 mm. The experimental results show that the formation rate of methane hydrate gradually decreases as the reaction goes on, and it is higher in layered sand than in nonlayered sand in the beginning. With the increase of the sand size in the lower part, saturation of methane hydrate gradually decreases in the upper part and increases in the lower part. In the layered sand, saturation of methane hydrate is higher in the sand layer whose particle size is bigger. The abovementioned results can be used to predict the favorable area where methane hydrate may appear in different stratigraphic structures in nature.

14.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 32(10): 1194-1198, 2020 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-33198862

RESUMO

OBJECTIVE: To investigate the c-Jun N-terminal kinase (JNK), CCAAT/enhancer-binding protein homologous protein (CHOP) pathway apoptosis and the changes of cytokine levels in immune-related organs and tissues of sepsis mice at different time points. METHODS: Twenty-seven male BALB/c mice were divided into normal group, sepsis 6 hours group and sepsis 12 hours group by the block randomization method, with 9 mice in each group. The sepsis model was made by cecal ligation and puncture (CLP). Blood sample was collected from each group at the corresponding time point, and the serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL-1ß, IL-10) were measured by enzyme linked immunosorbent assay (ELISA). The spleen, thymus and appendix tissues were taken from the mice to detect the expressions of phosphorylation-JNK (p-JNK), JNK1, CHOP and cleaved caspase-3 protein by Western Blot. RESULTS: The level of cytokines, p-JNK/JNK1 ratio, CHOP and caspase-3 in spleen tissues, and the CHOP, caspase-3 in thymus and appendix tissue in the sepsis 6 hours group were significantly higher than those in the normal group [serum TNF-α (ng/L): 24.29±3.09 vs. 2.93±2.09, serum IL-1ß (ng/L): 5.00±3.19 vs. 3.54±1.53, serum IL-10 (ng/L): 1 963.93±270.20 vs. 275.09±45.21, spleen p-JNK/JNK1 ratio: 0.257±0.126 vs. 0.154±0.068, spleen CHOP/ß-actin: 0.201±0.131 vs. 0.142±0.068, spleen caspase-3/ß-actin: 0.215±0.126 vs. 0.098±0.088, thymus CHOP/ß-actin: 0.122±0.071 vs. 0.089±0.067, thymus caspase-3/ß-actin: 0.258±0.145 vs. 0.108±0.045, appendix CHOP/ß-actin: 0.361±0.134 vs. 0.215±0.112, appendix caspase-3/ß-actin: 0.439±0.211 vs. 0.321±0.145, all P < 0.05]. However, there were no significant difference in the p-JNK/JNK1 ratio in thymus and appendix (thymus p-JNK/JNK1 ratio: 1.221±0.776 vs. 1.168±0.475, appendix p-JNK/JNK1 ratio: 2.014±1.227 vs. 1.828±0.915, both P > 0.05). Cytokine levels and the p-JNK/JNK1 ratio, CHOP, caspase-3 in spleen, thymus, and appendix in the sepsis 12 hours group were further increased when compared with those in the sepsis 6 hours group, except for a significant decrease in IL-10 level [serum IL-10 (ng/L): 1 698.98±210.52 vs. 1 963.93±270.20, serum TNF-α (ng/L): 41.66±6.57 vs. 24.29±3.09, serum IL-1ß (ng/L): 10.37±4.14 vs. 5.00±3.19, spleen p-JNK/JNK1 ratio: 0.399±0.135 vs. 0.257±0.126, spleen CHOP/ß-actin: 0.298±0.145 vs. 0.201±0.131, spleen caspase-3/ß-actin: 0.353±0.145 vs. 0.215±0.126, thymus p-JNK/JNK1 ratio: 1.667±0.891 vs. 1.221±0.776, thymus CHOP/ß-actin: 0.207±0.133 vs. 0.122±0.071, thymus caspase-3/ß-actin: 0.416±0.179 vs. 0.258±0.145, appendix p-JNK/JNK1 ratio: 2.425±1.361 vs. 2.014±1.227, appendix CHOP/ß-actin: 0.456±0.189 vs. 0.361±0.134, appendix caspase-3/ß-actin: 0.635±0.289 vs. 0.439±0.211, all P < 0.05]. CONCLUSIONS: The endoplasmic reticulum pathway JNK and CHOP pathways are involved in immune-related cell apoptosis and cytokine expression in mice with sepsis. Apoptosis is more obvious at 12 hours than at 6 hours, and the inflammatory response is stronger.


Assuntos
Sepse , Animais , Apoptose , Citocinas , MAP Quinase Quinase 4 , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Transdução de Sinais , Fator de Necrose Tumoral alfa
15.
Q J Exp Psychol (Hove) ; : 1747021820966264, 2020 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-32988297

RESUMO

Recent studies have demonstrated that in visual working memory (VWM), only items in an active state can guide attention. Further evidence has revealed that items with higher perceptual salience or items prioritised by a valid retro-cue in VWM tend to be in an active state. However, it is unclear which factor (perceptual salience or retro-cues) is more important for influencing the item state in VWM or whether the factors can act concurrently. Experiment 1 examined the role of perceptual salience by asking participants to hold two features with relatively different perceptual salience (colour vs. shape) in VWM while completing a visual search task. Guidance effects were found when either colour or both colour and shape in VWM matched one of the search distractors but not when shape matched. This demonstrated that the more salient feature in VWM can actively guide attention, while the less salient feature cannot. However, when shape in VWM was cued to be more relevant (prioritised) in Experiment 2, we found guidance effects in both colour-match and shape-match conditions. That is, both more salient but non-cued colour and less salient but cued shape could be active in VWM, such that attentional selection was affected by the matching colour or shape in the visual search task. This suggests that bottom-up perceptual salience and top-down retro-cues can jointly determine the active state in VWM.

16.
Chem Commun (Camb) ; 56(83): 12636-12639, 2020 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-32960196

RESUMO

Sensor saturation remains an obstacle to achieve reliable and quantitative detection of a specific gas at a high concentration. Herein, a new type of H2 sensor based on Au@Pd nanoparticle arrays (NAs) is demonstrated. While preserving a wide detection-range of 0.1-100% H2 concentrations, the Au@Pd NAs show a controllable saturation behavior depending on the Pd shell thickness. Mechanistically, this superior performance derives from the synergistic effect between the unique Au@Pd core-shell morphology and the rearrangement of Au@Pd nanoparticles during pre-conditioning. Our work represents a very promising strategy to design H2 sensors with enhanced performance at a high H2 concentration.

17.
ACS Appl Mater Interfaces ; 12(38): 42971-42981, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32865972

RESUMO

Developing a simple strategy to fabricate high-performance hydrogen sensors with long-term stability remains quite challenging. Here, we report the H2-sensing performance of Pd-decorated PdO hollow shells (Pd/PdO HSs). In this novel system, the catalyst nanoparticles (Pd NPs) and semiconductor support (PdO) are interconvertible, which is different from traditional hydrogen-sensing systems such as Pd/TiO2 and Pd/ZnO. This Pd/PdO system exhibits multiple unique properties. First, well-distributed Pd NPs with controllable density can be decorated on PdO support through a one-step NaBH4 treatment during which PdO is partially reduced into Pd. Second, the decorated Pd NPs are physically inlaid in the PdO support, which not only prevents the agglomeration or detachment of Pd NPs but also enhances the electron transfer between Pd NPs and PdO. Third, Pd/PdO HSs can be reoxidized into PdO HSs once their sensing performance degrades, which repeatedly manipulates Pd/PdO HSs under the initial reduction process, leading to the reactivation of the sensing performance. With all these advantages, Pd/PdO HSs demonstrate a detection limit lower than 1 ppm, a response/recovery time to 1% H2 of 5 s/32 s at room temperature, and a repeatable reactivation ability. The strategy presented here is convenient and time saving and has no need to prefunctionalize the PdO surface for the decoration of catalyst NPs. Moreover, the unique reactivation ability of Pd/PdO system opens a new strategy toward extending the lifetime of H2 sensors.

18.
Front Psychol ; 11: 1940, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32849139

RESUMO

In real-world scenarios, objects' surface features sometimes change as they move, impairing the continuity of objects. However, it is still unknown how our visual system adapts to this dynamic change. Hence, the present study investigated the role of feature changes in attentive tracking through a modified multiple object tracking (MOT) task. The feature heterogeneity and feature stability were manipulated in two experiments. The results from Experiment 1 showed that the tracking performance under feature-changed condition was lower than that under the feature-fixed condition only when the objects were four colors grouped or all unique, suggesting that the performance decrease was moderated by the feature heterogeneity. In Experiment 2, we further examined this effect by manipulating the frequency of feature change. The results showed that when the target set was one color or two colors grouped (the color grouping for the distractor set corresponded with it), the tracking performance decreased significantly as the feature-change frequency increased. However, this trend was not the case when the objects were of the same color or eight unique colors. In addition, a relatively consistent effect appeared both in Experiments 1 and 2. When objects have unique features, the tracking performance decreased significantly as the increase of feature heterogeneity in each frequency of feature changes. Taken together, we concluded that unstable features could be utilized in attentive tracking, and the extent to which the observers relied on surface feature information to assist tracking depended on the level of feature heterogeneity and the frequency of feature change.

19.
Eye (Lond) ; 2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678352

RESUMO

OBJECTIVES: Early identification of keratoconus is imperative for preventing iatrogenic corneal ectasia and allowing for early corneal collagen cross-linking treatments to potentially halt progression and decrease transplant burden. However, early diagnosis of keratoconus is currently a diagnostic challenge as there is no uniform screening criteria. We performed a review of the current literature to assess imaging modalities that can be used to help identify subclinical keratoconus. METHODS: A Pubmed database search was conducted. We included primary and empirical studies for evaluating different modalities of screening for subclinical keratoconus. RESULTS: A combination of multiple imaging tools, including corneal topography, tomography, Scheimpflug imaging, anterior segment optical coherence tomography, and in vivo confocal microscopy will allow for enhanced determination of subclinical keratoconus. In patients who are diagnostically borderline using a single screening criteria, use of additional imaging techniques can assist in diagnosis. Modalities that show promise but need further research include polarization-sensitive optical coherence tomography, Brillouin microscopy, and atomic force microscopy. CONCLUSIONS: Recognition of early keratoconus can reduce risk of post-refractive ectasia and reduce transplantation burden. Though there are no current uniform screening criterion, multiple imaging modalities have shown promise in assisting with the early detection of keratoconus.

20.
Langmuir ; 36(26): 7392-7399, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32493015

RESUMO

An interesting reversible shape and structure transformation between two types of two-dimensional (2D) metal-organic frameworks (MOFs) has been successfully achieved by the spray method. The ability to precisely control the morphology and structure of 2D MOFs is also developed by altering the amount of MOF precursors and reversing the spray order. Meanwhile, the mechanism of the transformation between two MOFs is studied and conversion is induced by the change of the acidity in the reaction system. In addition, the prepared non-interpenetrate CuBDC twists exhibit more remarkable catalytic performance in C-S coupling reaction than Cu(BDC)(DMF) nanosheets owing to the more unsaturated coordination copper active sites from the non-interpenetrate structure. The catalytic result reveals the relationship between structure and function.

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