Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 11.078
Filtrar
1.
BMC Cancer ; 20(1): 89, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32013967

RESUMO

BACKGROUND: We compared the efficacy and toxicity of three IC regimens (TPF: taxanes, cisplatin, and 5-fluorouracil; TP: taxanes and cisplatin; and PF: cisplatin and 5-fluorouracil) followed by CCRT in locoregionally advanced NPC. METHODS: The retrospective study involved 1354 patients with newly diagnosed stage III-IVA NPC treated with IC and CCRT. The median follow-up time in our cohort was 50 months. Based on EBV DNA level, all the patients with stage IV were divided into low- (pre-EBV DNA < 1500 copies) and high-risk group (pre-EBV DNA ≥ 1500 copies). Progression free survival (PFS), overall survival (OS), locoregional relapse free survival (LRFS), distant metastasis free survival (DMFS) and grade 3-4 toxicities were compared among different IC regimens. The survival rates were compared using log-rank test and a Cox proportional hazards model was used to perform multivariate analyses. RESULTS: A multivariate analysis revealed TPF to be more effective than TP. Among stage III patients, no significant difference in clinical outcome between the different IC regimens was showed, while TPF was associated with significantly better survival conditions in the stage IV patients. A further subgroup analysis revealed that only patients with pre-EBV DNA ≥ 1500 copies could benefit from the application of TPF among stage IV NPC. In terms of acute toxicities, PF was associated with fewer grade 3/4 acute toxicities. CONCLUSIONS: In low-risk NPC patients, PF-based IC showed similar efficacy as TPF and TP but was associated with fewer grade 3/4 acute toxicities. In high-risk patients, however, the TPF regimen was superior to PF and TP, although grade 3/4 toxicities were more common with the TPF regimen.

2.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(1): 30-36, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32037763

RESUMO

OBJECTIVE: This study aims to investigate the occlusal and myoelectric characteristics of implant-supported fixed denture in the mandibular region and provide reference for the design of fixed restoration. METHODS: Sixty edentulous patients with implant-supported fixed denture were selected and divided into three groups: group A, 20 cases with implant-supported fixed restoration in the maxillary region; group B, 20 cases with natural dentition, and group C, 20 cases with removable partial denture. The T-scan 8.0 digital occlusion analysis system was used to evaluate the occlusal characteristics of patients in the three groups at intercuspal, protrusion, and left and right lateral positions. Electromyography was used to analyze the myoelectric amplitude and bilateral asymmetry index of the anterior temporalis and masseter of the three groups in different states such as resting and clenching. The relationship between occlusion and myoelectricity was also investigated. RESULTS: In the occlusion analysis by T-scan, the occlusion time, the balance of left and right bite force, the left and right asymmetry of the occlusion center, the trajectory of central occlusion force, and the disclusion time were higher in group C than in groups A and B (P<0.05). No significant differences were observed in the anterior and posterior asymmetry of the occlusion center and percentage of bite force at anterior region among the three groups. In the analysis of myoelectricity, the myoelectric amplitude at resting state and the asymmetry index of masticatory muscles in group C were higher than those in groups A and B (P<0.05). The myoelectric amplitude during clenching in groups A and B groups was higher than that in group C (P<0.05). CONCLUSIONS: In implant-supported fixed restoration at edentulous mandibular, when maxillary includes the removable partial denture, degree of occlusal instability and left and right asymmetry of occlusion center are greater than those with the natural dentition and implant-supported fixed denture at maxillary. The myoelectricity is closely related to occlusion. The removable partial denture can increase the myoelectric activity and reduce the potential of the masticatory muscle. The asymmetry of bilateral myoelectricity is related to the occlusion imbalance.


Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Força de Mordida , Humanos , Mandíbula , Músculos da Mastigação
3.
Int J Biol Sci ; 16(3): 529-542, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32015688

RESUMO

Hyperuricemia (HUA) is a metabolic disease characterized by elevated serum uric acid (SUA). Empagliflozin, a kind of sodium-glucose cotransporter 2 inhibitors, has recently emerged as a new antidiabetic agent by facilitating glucose excretion in urine. Moreover, there was evidence of SUA reduction following treatment with empagliflozin in addition to glycaemic control, while the molecular mechanisms remain unknown. To investigate the potential mechanisms, the model of type 2 diabetes (T2DM) with HUA was established by combination of peritoneal injection of potassium oxonate and intragastric administration of hypoxanthine in KK-Ay mice. A series of method such as RT-PCR, western blot, immunochemistry, immunofluorescence were conducted to explore the mechanism. Our results showed that empagliflozin significantly ameliorated the levels of SUA and blood glucose in T2DM mice with HUA. Furthermore, in both kidney and ileum, empagliflozin obviously promoted protein expression of uric acid (UA) transporter ABCG2, p-AMPK, p-AKT and p-CREB. The same trend was observed in human tubular epithelial (HK-2) cells. Additionally, through application of an AMPK inhibitor (Compound C), it was further confirmed empagliflozin exerted its anti-hyperuricemic effects in an AMPK dependent manner. Meanwhile, with the help of ChIP assay and luciferase reporter gene assay, we found that CREB further activated ABCG2 via binding to the promoter of ABCG2 to induce transcription. Taken together, our study demonstrated that empagliflozin treatment played an essential role in attenuating HUA by upregulation of ABCG2 via AMPK/AKT/CREB signaling pathway.

4.
Artigo em Inglês | MEDLINE | ID: mdl-32023349

RESUMO

BACKGROUND AND AIM: No predictive model for lymph node metastasis (LNM) of superficial esophagogastric junction (EGJ) cancer exists. This study aimed to evaluate incidence, identify risk factors and to develop a predictive nomogram for LNM in patients with superficial EGJ cancers. METHODS: Data was extracted from the Surveillance, Epidemiology, and End Results (SEER) database for model development and internal validation. Another data set was obtained from two hospitals for external validation. A nomogram was developed based on independent risk factors resulted from multivariate logistic regression analysis. Internal and external validations were performed to assess the performance of nomogram model by receiver operating characteristic (ROC) and calibration plot. RESULTS: Prevalence of LNM was 11.41% for intramucosal cancer and increased to 26.50% for submucosal cancer. On multivariate analysis, large tumor size (odds ratio (OR) =1.42, P < 0.001), moderate and poor/undifferentiated pathological type (OR=5.62 and 7.67, p = 0.024 and 0.008, respectively) and submucosal invasion (OR=2.73, p =0.004) were independent risk factors of LNM. The nomogram incorporating these three predictors demonstrated good discrimination (AUC: 0.74, 95% confidence interval (95%CI): 0.68, 0.80) and calibration (mean absolute error was 0.012). Moreover, the discrimination in the internal and external validation set was good (AUC:0.73 (95%CI: 0.66, 0.81) and 0.74 (95%CI: 0.60, 0.89), respectively). Nomogram provided better clinical usefulness as assessed by decision curve analysis. CONCLUSIONS: Prevalence of LNM in superficial EGJ cancer was high. The first risk-predictive nomogram model for LNM of superficial EGJ cancer may help clinicians to decide optimal treatment option preoperatively.

5.
Genes (Basel) ; 11(2)2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32024145

RESUMO

Antimicrobial peptides (AMPs) are evolutionarily ancient molecules that play an essential role in innate immunity across taxa from invertebrates to vertebrates. The evolution system of AMP system has not been well explained in the literature. In this study, we cloned and sequenced AMP transcriptomes of three frog species, namely Rana dybowskii, Rana amurensis, and Pelophylax nigromaculatus, which are partially sympatric in northeast Asia, but show different habitat preferences. We found that each species contained 7 to 14 families of AMPs and the diversity was higher in species with a large geographic range and greater habitat variation. All AMPs are phylogenetically related but not associated with the speciation process. Most AMP genes were under negative selection. We propose that the diversification and addition of novel functions and improvement of antimicrobial efficiency are facilitated by the expansion of family members and numbers. We also documented significant negative correlation of net charges and numbers of amino acid residues between the propiece and mature peptide segments. This supports the Net Charge Balance Hypothesis. We propose the Cut Point Sliding Hypothesis as a novel diversification mechanism to explain the correlation in lengths of the two segments.

6.
Sci Transl Med ; 12(529)2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32024800

RESUMO

Osteoclasts actively remodel both the mineral and proteinaceous components of bone during normal growth and development as well as pathologic states ranging from osteoporosis to bone metastasis. The cysteine proteinase cathepsin K confers osteoclasts with potent type I collagenolytic activity; however, cathepsin K-null mice, as well as cathepsin K-mutant humans, continue to remodel bone and degrade collagen by as-yet-undefined effectors. Here, we identify a cathepsin K-independent collagenolytic system in osteoclasts that is composed of a functionally redundant network of the secreted matrix metalloproteinase MMP9 and the membrane-anchored matrix metalloproteinase MMP14. Unexpectedly, whereas deleting either of the proteinases individually leaves bone resorption intact, dual targeting of Mmp9 and Mmp14 inhibited the resorptive activity of mouse osteoclasts in vitro and in vivo and human osteoclasts in vitro. In vivo, Mmp9/Mmp14 conditional double-knockout mice exhibited marked increases in bone density and displayed a highly protected status against either parathyroid hormone- or ovariectomy-induced pathologic bone loss. Together, these studies characterize a collagenolytic system operative in mouse and human osteoclasts and identify the MMP9/MMP14 axis as a potential target for therapeutic interventions for bone-wasting disease states.

7.
J Am Chem Soc ; 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32026685

RESUMO

We report for the first time electron-transfer (ET) properties of mononuclear nonheme iron-oxo and -imido complexes with the formal oxidation states of five and six, such as an iron(V)-imido TAML cation radical complex, which is formally an iron(VI)-imido complex [FeV(NTs)(TAML+•)] (1; NTs = tosylimido), an iron(V)-imido complex [FeV(NTs)(TAML)]- (2), and an iron(V)-oxo complex [FeV(O)(TAML)]- (3). The one-electron reduction potential (Ered vs SCE) of 1 was determined to be 0.86 V, which is much more positive than that of 2 (0.30 V), but the Ered of 3 is the most positive (1.04 V). The rate constants of ET of 1 - 3 were analyzed in light of the Marcus theory of adiabatic outer-sphere ET to determine the reorganization energies (λ) of ET reactions with 1 - 3; the λ of 1 (1.00 eV) is significantly smaller than those of 2 (1.98 eV) and 3 (2.25 eV) because of the ligand-centered ET reduction of 1 as compared to the metal-centered ET reduction of 2 and 3. In oxidation reactions, reactivities of 1 - 3 towards the nitrene transfer (NT) and oxygen atom transfer (OAT) to thioanisole and its derivatives and the C-H bond activation reactions, such as the hydrogen atom transfer (HAT) of 1,4-cyclohexadiene, were compared experimentally. The differences in the redox reactivity of 1 - 3 depending on the reaction types, such as NT and OAT versus HAT, were interpreted by performing density functional theory calculations, showing that the ligand-centered reduction seen on ET reactions can switch to metal-centered reduction in NT and HAT.

8.
Immunol Invest ; : 1-15, 2020 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-32009472

RESUMO

BACKGROUND: Biological agents are commonly used for the treatment of ulcerative colitis (UC). As new treatments, tofacitinib, and fecal microbiota transplantation (FMT) have demonstrated efficacy in treating UC. This network meta-analysis aims to determine the efficacy and safety of biological agents, tofacitinib, and FMT. METHODS: A network meta-analysis was conducted by systematically searching the PubMed, Embase, and Cochrane Libraries. According to strict inclusion and exclusion criteria, we included randomized controlled trials (RCTs) of biological agents, tofacitinib, and FMT in UC. A random-effect model was chosen by the network meta-analysis and sensitivity analysis. Heterogeneity test and publication bias test were performed to determine the efficacy of treatments. RESULTS: Data were extracted from 16 RCTs and we found that all treatments were more effective than the placebos. A total of 21 comparisons were made to determine efficiency. We found that infliximab, vedolizumab, and FMT performed better curative effect in terms of absolute effects and relative ranks. Furthermore, there was no statistical difference in the efficacy of biological agents, tofacitinib, and FMT. Moreover, no treatments were found to increase the occurrence of adverse events when compared with placebos, except infliximab. However, vedolizumab seemed to reduce the occurrence of adverse events compared with infliximab. CONCLUSION: Of the biological agents, vedolizumab and infliximab were the most effective, suggesting that biological agents are still a better choice. Nevertheless, tofacitinib and FMT may be promising alternatives with high efficacies. However, more safety and maintenance studies need to be conducted in future for the acquisition of more accurate results.Abbreviations: FMT: Fecal microbiota transplantation; UC: Ulcerative colitis; RCTs: Randomized controlled trials; IBD: Inflammatory bowel disease; CD: Crohn's disease; IBS: Irritable bowel syndrome; CDI: Clostridium difficile infections; ITT: Intention-to-treat; RR: Relative risk; CI: Confidence interval; CrI: Credible intervals; IFX: Infliximab; ADA: Adalimumab; TFB: Tofacitinib; GLM: Golimumab; VDZ: Vedolizumab; PBO: Placebo; wk: week; F: Female; M: Male; AEs: Adverse events; SAEs: Serious adverse events; anti-TNF: Anti-tumor necrosis factors.

9.
Medicine (Baltimore) ; 99(3): e18841, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32011499

RESUMO

BACKGROUND: It has been reported the rs10757274 SNP (present on locus 9p21 in the gene for CDKN2BAS1) might be associated with susceptibility to coronary artery disease (CAD). Owing to mixed and inconclusive results, we conducted a meta-analysis to investigate the association between rs10757274 polymorphism and the risk of CAD. OBJECTIVES: The present study aimed to investigate the relationship between rs10757274 polymorphism and the risk of CAD. METHODS: All studies of the rs10757274 SNP with CAD that were published between 2007 and 2018 were retrieved from the PubMed database. Meta-analysis was performed with Stata 14.0 software. The effect size of the rs10757274 SNP with CAD risk was assessed based on the odds ratios (ORs) with calculation of 95% confidence interval (CI). RESULTS: Eleven studies including 52,209 subjects (cases: 7990, controls: 44,219) were included in the final data combination. Pooled overall analyses showed that rs10757274 (allele model: P < .001; dominant model: P < .001; recessive model: P < .001; Heterozygote codominant: P = .002; Homozygote codominant: P < .001) polymorphisms were significantly associated with the likelihood of CAD. Significant heterogeneity between individual studies appears in all 5 models. Further subgroup analyses revealed that rs10757274 polymorphisms were all significantly correlated with the likelihood of CAD and no heterogeneity were observed in West Asians. CONCLUSIONS: Our findings indicated that rs10757274 polymorphisms may serve as genetic biomarkers of CAD, especially in West Asians.

10.
Clin Appl Thromb Hemost ; 26: 1076029620904131, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32013541

RESUMO

There is a lack of studies on anticoagulant plus antiplatelet therapy for acute ischemic stroke. The present study made a pilot effort to investigate the efficacy and safety of argatroban plus dual antiplatelet therapy (DAPT) in patients with acute posterior circulation ischemic stroke (PCIS). We retrospectively collected patients diagnosed with acute PCIS according to inclusion/exclusion criteria. According to treatment drugs, patients were divided into an argatroban plus DAPT group and a DAPT group. The primary efficacy end point was the proportion of early neurological deterioration (END). The primary safety outcome was symptomatic intracranial hemorrhage. All outcomes were compared between the 2 groups before and after propensity score matching (PSM). A total of 502 patients were enrolled in the study, including 35 patients with argatroban plus DAPT and 467 patients with DAPT. There was a higher National Institutes of Health Stroke Scale (NIHSS) score in the argatroban plus DAPT group than the DAPT group before PSM (3 vs 2, P = .017). Compared with the DAPT group, the argatroban plus DAPT group had no END (before PSM: 0% vs 6.2%, P = .250; after PSM: 0% vs 5.9%, P = .298). Argatroban plus DAPT yielded a significant decrease in the NIHSS score from baseline to 7 days after hospitalization, compared with that of the DAPT group before PSM (P = .032), but not after PSM (P = .369). No symptomatic intracranial hemorrhage was found in any patient. A short-term combination of argatroban with DAPT appears safe in acute minor PCIS.

11.
Artigo em Inglês | MEDLINE | ID: mdl-32003210

RESUMO

For the first time, we report the successful fabrication of well-behaved field-effect transistors based on Nb-doped ß-Ga2O3 nanobelts mechanically exfoliated from bulk single crystals. The exfoliated ß-Ga2O3 nanobelts were transferred onto a purified surface of the 110 nm SiO2/Si substrate. These Nb-doped devices showed excellent electrical performance such as an ultrasmall cutoff current of ∼10 fA, a high current on/off ratio of >108, and a quite steep subthreshold swing (SS, ∼120 mV/decade). Furthermore, we investigated the temperature dependence down to 200 K, providing insightful information for its operation in a harsh environment. This work lays a foundation for wider application of Nb-doped ß-Ga2O3 in nano-electronics.

12.
Cryobiology ; 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-32001217

RESUMO

Melatonin is a ubiquitous indoleamine hormone synthesized primarily by the pineal gland. Diverse biological actions of melatonin involve quite complex mechanisms via its membrane receptors. More recently, studies have focused on the role of melatonin in male fertility preservation and male reproductive system. The protective effects of melatonin on immature testicular tissue freshness and activity maintenance and the preservation of sperm and spermatogonial stem cells (SSCs) have attracted considerable attention in recent years. Furthermore, since melatonin has strong antioxidant and anti-apoptotic properties, researchers have examined its potential role in male reproductive system. In this article, recent progress regarding melatonin's effects on male fertility preservation and its potential role is reviewed.

13.
Phys Chem Chem Phys ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32048669

RESUMO

It has long been a challenge in physics and chemistry to acquire a global picture of the energy landscape of a specific material, as well as the kinetic transformation process between configurations of interest. Here we have presented a comprehensive approach to deal with the structure transformation problem, along with the illustration of the energy landscape, as exemplified with the case of Au13. A configuration space based on interatomic distances was proposed and demonstrated to have a strong correlation between structure and energy, with application in structure analysis to screen for trial transition pathways. As several representative configurations and their transition pathways ascertained and by projecting on a plane, a visual two-dimensional contour map was sketched revealing the unique energy landscape of Au13. It shows that the 2D and 3D clusters form two funnels in the high-dimensional configuration space, with a transition pathway with a 0.976 eV barrier bridging them.

14.
J Dig Dis ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32049422

RESUMO

Endoscopic submucosal dissection (ESD) is generally used to treat a variety of superficial gastric mucosal and submucosal lesions. Nevertheless, ESD is more difficult and complicated compared to traditional endoscopic mucosal resection (EMR) and also requires longer operation time, which can increase the incidence of various complications including delayed bleeding, perforation, and infection. Among them, delayed hemorrhage is a major post-ESD complication. The early and accurate evaluation and precaution of post-ESD bleeding for gastric lesions is related to the success rate of the operation and the safety of patients. At present, there are many studies about the risks and preventative measures for delayed hemorrhage after gastric ESD, but there are still many problems that have not been solved. Therefore, this article will review the risk factors, precautions and treatments for delayed hemorrhage after the ESD of gastric lesions. The endoscopist should fully understand these risk factors, precautions and treatment methods to ensure the safety and effectiveness of the entire ESD process. This article is protected by copyright. All rights reserved.

15.
J Anal Toxicol ; 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32020177

RESUMO

MDMB-CHMINACA is a newly synthetic cannabinoid which scoped in NMS Lab, USA. Since there are currently no published data on MDMB-CHMINACA metabolism, we aimed to identify its biotransformation pathways and major metabolites. Liquid chromatography Q-Extractive HF Hybrid Quadrupole-Orbitrap mass spectrometry (LC-QE-HF-MS) using full scan positive ion mode and targeted MS/MS (ddms2) techniques with accurate mass measurement were employed to analyze the metabolic sites and pathways. An in vivo metabolic animal model of zebrafish was established to verify the metabolic pathways of MDMB-CHMINACA obtained from human liver microsomal experiment in vitro. The results showed that 29 metabolites were generated in the zebrafish animal model and human liver microsomes model. Biotransformations mainly occurred at the cyclohexylmethyl tail of the compound, minor reactions also occurred at the tert-butyl chain, and no reaction was analysised at the indazole ring. We recommend M1 group (MDMB-CHMINACA ester hydroxylation), and M2 group (MDMB-CHMINACA monohydroxylation) as the potential poisoning markers to document MDMB-CHMINACA intake in clinical and forensic cases. Additionally, this study provides preliminary information regarding the metabolism of MDMB-CHMINACA that will guide analytical standard manufacturers to better provide suitable references for further studies on newly encountered designer drugs.

16.
Artigo em Inglês | MEDLINE | ID: mdl-32020504

RESUMO

Whether intra-myocardial delivery of hydrogel can prevent post-infarct heart failure (HF) in a long follow-up period, especially after it is degraded, remains unclear. In this study, Dex-PCL-HEMA/PNIPAAm (DPHP) hydrogel was delivered into peri-infarct myocardium of rat when coronary artery was ligated, while PBS was employed as control. Twelve weeks later, compared with control, left ventricle remodeling was attenuated and cardiac function was preserved; serum brain natriuretic peptide, cardiac aldosterone, and pulmonary congestion were suppressed in hydrogel group. Pro-fibrogenic mRNA increased in infarct area while decreased in remote zone, as well as hypertrophic mRNA. These data proves DPHP hydrogel suppresses ventricular remodeling and HF by promoting fibrotic healing in infarct area and inhibiting reactive fibrosis and hypertrophy in remote zone. Timely intra-myocardial hydrogel implantation is an effective strategy to inhibit post-infarct cardiac remodeling and have a long-term beneficial effect even after it has been biodegraded.

17.
Am J Hosp Palliat Care ; : 1049909120902123, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32022578

RESUMO

OBJECTIVE: The purpose of this study is to understand the attitude of undergraduate nursing students toward advanced care planning (ACP) and their willingness to implement ACP and to analyze its influencing factors, so as to provide evidence-based basis for life and death education and ACP-related training in colleges and universities. METHODS: A total of 312 nursing undergraduates from a university in Chengdu (China) were surveyed by using general information questionnaire, attitude scale of ACP, and willingness questionnaire to implement ACP. RESULTS: The scores of undergraduate nursing students' attitude toward ACP were 24.97 ± 2.75, and the scores of total willingness to ACP were 79.26 ± 9.70. Univariate analysis and multivariate linear regression analysis showed that religious belief, grade, family relationship, and family discussion of death were the factors influencing the willingness of nursing students to carry out ACP. CONCLUSIONS: The attitude of undergraduate nursing students toward ACP tended to be positive, but their cognition of ACP was misunderstood, and their willingness to implement ACP needed to be improved. To improve the awareness and implementating willingness of undergraduate nursing students to ACP, it was recommended that colleges and universities carried out systematic standardized life and death education courses and ACP-related training.

18.
Neuropsychologia ; : 107383, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32057933

RESUMO

During comprehension, language users not only immediately integrate information from local sentence context, but also information from global discourse context for full understanding. In the present study, we examined whether the time course of these integration processes is constrained by language users' working memory capacity. Sentence and discourse stimuli were constructed. For the sentence stimuli, each sentence contained a critical word that was either congruent or incongruent with its preceding sentence context. For the discourse stimuli, each discourse contained four sentences with a target word embedded at the final sentence and the target word was either congruent or incongruent with the information provided at the first sentence of the discourse. Participants of high and low working memory span were instructed to read for comprehension. Our results showed that while the high span readers showed the N400 and P600 effects to semantically incongruent words, the low span readers only showed the P600 effect. This pattern was found regardless of whether the incongruent words were placed at sentence or discourse context. These results suggest that the low span readers are relatively delayed than the high span ones at both sentence- and discourse-level semantic integration and indicate that working memory functions have greater influence than context scope on the time course of semantic integration.

19.
Mol Cell Biol ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041821

RESUMO

Circular RNAs (circRNAs) are a class of noncoding RNAs produced by a non-canonical form of alternative splicing called back-splicing. To investigate a potential role of circRNAs in the p53 pathway, we analyzed RNA-seq data from colorectal cancer cell lines (HCT116, RKO and SW48) untreated or treated with a DNA damaging agent. Surprisingly, unlike the strong p53-dependent induction of hundreds of p53-induced mRNAs upon DNA damage, only a few circRNAs were upregulated from p53-induced genes. Circ-MDM2, an annotated circRNA from the MDM2 locus, was one of the handful of circRNAs that originated from a p53-induced gene. Given the central role of MDM2 in suppressing p53 protein levels and p53 activity, we investigated the function of circ-MDM2 Knocking down circ-MDM2 with siRNAs that targeted circ-MDM2, did not alter MDM2 mRNA or MDM2 protein levels, but resulted in increased basal p53 levels and growth defects in vitro and in vivo Consistent with these results, transcriptome profiling showed increased expression of several direct p53 targets, reduced Rb phosphorylation and defects in G1-S progression upon silencing circ-MDM2 Our results on the initial characterization of circ-MDM2, identify a new player from the MDM2 locus that suppresses p53 levels and cell cycle progression.

20.
ChemSusChem ; 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32043801

RESUMO

The mechanisms of oxygen reduction reaction (ORR) on gold surfaces are revisited in electrolytes at different pH values by the combination of electrochemical and in-situ Surface Enhanced Raman Scattering measurements. Surprisingly, the in-situ Raman signal of O-O stretching vibration has been detected during ORR process on Au surface unusually by using a 785 nm laser. Both the intermediate products of O 2 - and H 2 O 2 could be detected, indicating that the difficulty of further reduction H 2 O 2 , thus resulting in a lower electron transfer number, especially in neutral and acid electrolytes. The weak absorption ability of HO 2 on Au surface may explain the poor catalytic performances of ORR in neutral and acid electrolytes. This work could not only provide a deep insight to understand the reduction mechanisms of O 2 on Au in electrolytes at different pH values, but also supply a new idea for the selection and optimization of the electrolytes and efficient electrocatalysts for oxygen reduction.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA