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1.
Prev Sci ; 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34751887

RESUMO

Although perceived parental warmth and "peer victimization and peer perpetration" are believed to be unidirectionally related, researchers have not examined the possibility of bidirectional relations among them, especially with regard to within-child relations. We thus explored the dynamic longitudinal associations among children's perceived parental warmth (maternal warmth and paternal warmth), peer perpetration, and peer victimization at the within-child level. A total of 3720 Chinese children (Mage = 9.95 years at Time 1, 46.1% girls) were investigated on five occasions, every 6 months. Random Intercept Cross-Lagged Panel Models (RI-CLPMs) were applied to estimate the within-child associations among these variables. The results were: (1) for peer perpetration, peer perpetration inversely predicted subsequent perceived parental warmth, while perceived maternal (but not paternal) warmth inversely predicted subsequent peer perpetration; (2) for peer victimization, perceived maternal and paternal warmth both inversely predicted a child's subsequent peer victimization, and perceived parental warmth and peer victimization bidirectionally predicted each other; and (3) peer perpetration and peer victimization bidirectionally predicted each other. These findings enhance understanding of how perceived parental warmth temporally interrelates with peer perpetration and peer victimization from a positive spillover theory perspective, as well as how peer perpetration temporally interrelates with peer victimization from a negative vicious cycle perspective.

2.
Front Immunol ; 12: 744242, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804024

RESUMO

The global pandemic of the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), places a heavy burden on global public health. Four SARS-CoV-2 variants of concern including B.1.1.7, B.1.351, B.1.617.2, and P.1, and two variants of interest including C.37 and B.1.621 have been reported to have potential immune escape, and one or more mutations endow them with worrisome epidemiologic, immunologic, or pathogenic characteristics. This review introduces the latest research progress on SARS-CoV-2 variants of interest and concern, key mutation sites, and their effects on virus infectivity, mortality, and immune escape. Moreover, we compared the effects of various clinical SARS-CoV-2 vaccines and convalescent sera on epidemic variants, and evaluated the neutralizing capability of several antibodies on epidemic variants. In the end, SARS-CoV-2 evolution strategies in different transmission stages, the impact of different vaccination strategies on SARS-CoV-2 immune escape, antibody therapy strategies and COVID-19 epidemic control prospects are discussed. This review will provide a systematic and comprehensive understanding of the secret of SARS-CoV-2 variants of interest/concern and immune escape.


Assuntos
COVID-19 , Evasão da Resposta Imune , SARS-CoV-2 , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , COVID-19/tratamento farmacológico , COVID-19/imunologia , COVID-19/prevenção & controle , COVID-19/transmissão , Vacinas contra COVID-19 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade
3.
Sch Psychol ; 2021 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-34647768

RESUMO

This study explored the relations among peer victimization (i.e., physical, relational, and cyberbullying victimization), learning flow, and academic achievement among elementary school students, using a seven-wave longitudinal design across four consecutive semesters. Participants were 1,440 students from Grades 3 and 4 in China (Mage = 9.91 years, 52.4% male). Measures of peer victimization and learning flow were completed in the middle of every semester, from the second to fourth semesters. Academic achievement was measured via students' final exam scores in Chinese, Math, and English at the end of each semester. The results indicated that: (a) relational victimization, but not physical and cyberbullying victimization, directly predicted subsequent lower academic achievement; in the reverse path, lower academic achievement predicted all three types of subsequent peer victimization; (b) learning flow directly predicted academic achievement and vice versa; and (c) learning flow mediated the relations between the three types of peer victimization and lower academic achievement. The findings suggested that educational experiences are needed that both protect elementary school students from relational victimization and facilitate learning flow to promote students' academic achievement. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

4.
Dose Response ; 19(4): 15593258211039931, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34658683

RESUMO

Objective: To study the effects of adaptive response in A549 cells induced by low-dose radiation and the miRNAs expression. Methods: A549 cells were irradiated with 50 mGy and 200 mGy initial doses, respectively, and then irradiated with a challenge dose 20 Gy at 6 hours interval. The biological effects and miRNA expression were detected. Results: The apoptosis rates of 50 mGy-20 Gy and 200 mGy-20 Gy groups were significantly lower than that of only 20 Gy irradiation group (P < .05). The percentage of G2/M phase cells of 50 mGy-20 Gy and 200 mGy-20 Gy groups was significantly decreased relative to the 20 Gy group (P < .05). One miRNA (mir-3662) was upregulated and 15 miRNAs (mir-185, mir-1908, mir-307, mir-182, mir-92a, mir-582, mi-r501, mir138-5p, mir-1260, mir-484, mir-378d, mir-193b, mir-127-3p, mir-1303, and mir-654-5p) were downregulated both in 50 mGy-20 Gy and 200 mGy-20 Gy groups than that of the 20 Gy group. Go and KEGG enrichment analysis showed that the target genes were significantly enriched in cell communication regulation, metabolic process, enzyme binding, and catalytic activity signaling pathways. Conclusion: Low-dose X-ray of 50 mGy and 200 mGy radiation can induce adaptive apoptosis response prior to 20 Gy in A549 cells. Sixteen differently expressed miRNAs may play important roles in the adaptive effect of low-dose radiation.

5.
Environ Sci Technol ; 55(21): 14928-14937, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34676765

RESUMO

Geobacter spp. are well-known exoelectrogenic microorganisms that often predominate acetate-fed biofilms in microbial fuel cells (MFCs) and other bioelectrochemical systems (BESs). By using an amplicon sequence variance analysis (at one nucleotide resolution), we observed a succession between two closely related species (98% similarity in 16S RNA), Geobacter sulfurreducens and Geobacter anodireducens, in the long-term studies (20 months) of MFC biofilms. Geobacter spp. predominated in the near-electrode portion of the biofilm, while the outer layer contained an abundance of aerobes, which may have helped to consume oxygen but reduced the relative abundance of Geobacter. Removal of the outer aerobes by norspermidine washing of biofilms revealed a transition from G. sulfurreducens to G. anodireducens. This succession was also found to occur rapidly in co-cultures in BES tests even in the absence of oxygen, suggesting that oxygen was not a critical factor. G. sulfurreducens likely dominated in early biofilms by its relatively larger cell size and production of extracellular polymeric substances (individual advantages), while G. anodireducens later predominated due to greater cell numbers (quantitative advantage). Our findings revealed the interspecies competition in the long-term evolution of Geobacter genus, providing microscopic insights into Geobacter's niche and competitiveness in complex electroactive microbial consortia.


Assuntos
Fontes de Energia Bioelétrica , Geobacter , Biofilmes , Eletrodos , Geobacter/genética
6.
Soc Sci Med ; 291: 114483, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34656917

RESUMO

RATIONALE: Emotional maltreatment and bullying (including both bullying perpetration and bullying victimization) are two prevalent and highly related problems among children and adolescents worldwide. The adverse consequences of emotional maltreatment and bullying behoove researchers to identify their causal mechanisms. OBJECTIVE: We examined the reciprocal relations between emotional maltreatment and bullying perpetration/victimization and whether depressive symptoms functioned as mediator of the relations, after separating within-person effects from between-person effects. METHODS: A total of 4273 Chinese early adolescents (45.2% girls; Mage = 9.90 years, SD = 0.73) participated in a five-wave longitudinal study with 6-month intervals. RESULTS: Results from random intercept cross-lagged panel modeling showed: (a) emotional maltreatment and bullying perpetration were bidirectionally related; (b) bullying victimization directly predicted emotional maltreatment, but not vice versa; (c) emotional maltreatment indirectly predicted bullying perpetration/victimization via depressive symptoms; and (d) bullying victimization indirectly predicted emotional maltreatment via depressive symptoms. CONCLUSIONS: These findings provided evidence for bidirectional spillover effects in the family and peer domains, demonstrating that early adolescents may become trapped in a vicious cycle of negative relationships, directly or indirectly, via their depressive symptoms. To prevent a downward spiral, findings suggested that bullying interventions need to address family and peer relationships as well as individual psychological well-being simultaneously to be most effective.

7.
J Magn Reson Imaging ; 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34480787

RESUMO

BACKGROUND: Noninvasive evaluation of the status of cerebral arteriole perfusion remains a practical challenge in murine stroke models, because conventional magnetic resonance imaging (MRI) is no longer capable of capturing these very small vessels. PURPOSE: To investigate the feasibility of ultrasmall superparamagnetic iron oxide particles (USPIO)-based susceptibility weighted imaging (SWI)-MRI (USPIO-SWI) and T2* map-MRI (USPIO-T2* map) for monitoring angiographic perfusion in stroke rats. STUDY TYPE: A preclinical randomized controlled trial. ANIMAL MODEL: Normal rats (N = 9), embolic middle cerebral artery occlusion (eMCAO) rats (N = 66). FIELD STRENGTH/SEQUENCE: 7 T; T2* map (multigradient echo), SWI (3D gradient echo). ASSESSMENT: Experiment 1: To develop a method for angiographic reperfusion evaluation with USPIO-SWI. Normal rats were used to optimize the USPIO dosage (5.6, 16.8, and 56 mg/kg ferumoxytol) as well as scan time points for cerebral arterioles. Contrast-to-noise ratio (CNR) was measured. Stroke rats were further used and the number of visual cortical vessels were counted. Experiment 2: To examine whether fingolimod (lymphocytes inhibitor) enhances the action of tissue plasminogen activator (tPA) in eMCAO rats on cerebral angiographic reperfusion. STATISTICAL TESTS: Mann-Whitney test and two way-ANOVA were used. P < 0.05 was considered statistically significant. RESULTS: CNR values of cerebral cortical penetrating arteries in normal rats were significantly increased to 4.4 ± 0.5 (5.6 mg/kg), 6.1 ± 0.5 (16.8 mg/kg), and 3.4 ± 0.9 (56 mg/kg) after USPIO injection. The number of visual cortical vessels on USPIO-SWI images in ischemic regions was significantly less than in control regions (5 ± 2 vs. 56 ± 20) of eMCAO rats. Compared with eMCAO rats who received tPA only, eMCAO rats who received the combination of fingolimod and tPA exhibited significantly higher proportion of complete angiographic reperfusion (69% vs. 17%). DATA CONCLUSION: This study supports the feasibility of angiographic perfusion evaluation with USPIO-SWI in stroke rats. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 1.

8.
Andrology ; 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34516050

RESUMO

BACKGROUND: Oncostatin M (OSM) is a member of the interleukin-6 group of cytokines, which can regulate cell proliferation, growth, and function. Immature Leydig cells have the ability to proliferate and differentiate, and adult Leydig cells have the function of testosterone synthesis. However, the role and underlying mechanisms of OSM on the proliferation and function of Leydig cells remain unclear. METHODS: The effects of OSM on the proliferation, apoptosis, and function of immature Leydig cells isolated from 35-day-old rats and the function of adult Leydig cells isolated from 63-day-old rats in vitro. RESULTS: OSM stimulated immature Leydig cell proliferation after up-regulating the expression of Ccnd1 and Cdk4 to drive the transition of G1 phase to M2 phase in the cell cycle at 10 and 100 ng/ml. OSM did not affect the apoptosis of immature Leydig cells up to 100 ng/ml. OSM inhibited testosterone production in immature and adult Leydig cells by down-regulating the expression of Lhcgr, Star, Cyp11a1, Hsd3b1, and Cyp17a1 at 1-100 ng/ml. OSM induced reactive oxygen species and down-regulated the expression of antioxidant genes and lowered mitochondrial membrane potential at 10 and 100 ng/ml in both Leydig cells. Janus kinase 1 (JAK1) antagonist filgotinib and signal transducer and activator of transcription 3 (STAT3) antagonist S3I-201 reversed the effect of OSM, indicating that it acts on JAK1/STAT3 signaling. CONCLUSION: Oncostatin M stimulates immature Leydig cell proliferation while inhibiting the function of immature and adult Leydig cells.

9.
J Affect Disord ; 295: 216-224, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34481150

RESUMO

BACKGROUND: Previous research has identified a significant, positive relation between childhood maltreatment and depressive symptoms. However, the findings required replication at the within-person level. Moreover, the mediating mechanism of locus of control accounting for their relations has yet to be fully evaluated. Thus, this study examined the dynamic longitudinal relations between childhood maltreatment and depressive symptoms including whether locus of control functioned as a mediator between them after separating between-person effects from within-person effects. METHODS: A sample of 4110 Chinese children (50.60% boys; Mage = 9.89 at Wave 1) covering the transitional period from middle childhood to early adolescence completed a package of self-report measures on 5 occasions across 2.5 years, using 6-month intervals. Random Intercept Cross-Lagged Panel Models were applied to disaggregate between- and within-person effects. Also, alternative Cross-Lagged Panel Models were applied. RESULTS: Locus of control played a mediating role in the reciprocal relations between childhood maltreatment and depressive symptoms at the within-person level. LIMITATIONS: Some limitations existed in the measures. Moreover, sexual abuse was not investigated in this study. CONCLUSIONS: The findings highlighted the mediating role of locus of control in the reciprocal relations between childhood maltreatment and depressive symptoms at the within-person level, suggesting that interventions targeted at promoting internal locus of control may help prevent the developmental pathway from childhood maltreatment to depressive symptoms and vice versa from middle childhood to early adolescence.


Assuntos
Maus-Tratos Infantis , Depressão , Adolescente , Criança , Feminino , Humanos , Controle Interno-Externo , Masculino
10.
J Mech Behav Biomed Mater ; 124: 104830, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34530300

RESUMO

In this work, molecular dynamics simulations are conducted to investigate the structural and mechanical properties of dental materials, i.e., the silica nanorod reinforced Bis-GMA/TEGDMA resin composite. The effects of loading content and size of the silica nanorods on the composite stiffness were performed by examining resin chain conformation, hydrogen bonds and matrix/filler binding energy. It is revealed that the presence of the silica nanorod causes polymer chain expansion, endowing the resins with higher stiffness. Moreover, the volumetric hydrogen bonds and binding energy increase considerably with the loading content, but decrease gradually with the diameter or show almost independence of the length. Furthermore, the composite moduli were quantified by the micromechanics models and the transverse moduli were well predicted by the Counto model, signifying a perfect bonding between the matrix and nanorod. The chain expansion and energetic matrix/filler interactions are believed to contribute to the significant mechanical reinforcement of the composites with the loading content. However, the length of the nanorod has a little effect on the composite moduli due to the unaltered interfacial interaction. In contrast, a smaller diameter is supposed to give a larger modulus, and this is not observed in this work due to the synergic effects of improved matrix/filler interaction and actual reduced filler volume fraction. The mechanical enhancement by the rod-like structures is more influenced by the loading content, but less so by the size of the nanorod, and it also exhibits superior mechanical performance as compared to nanoparticles. The findings thus extend the current understanding of the nanostructure and mechanical properties of silica nanorod reinforced dental resin composites from an atomic/molecular perspective.


Assuntos
Nanotubos , Dióxido de Silício , Bis-Fenol A-Glicidil Metacrilato , Resinas Compostas , Teste de Materiais , Simulação de Dinâmica Molecular , Maleabilidade , Ácidos Polimetacrílicos , Propriedades de Superfície
11.
Talanta ; 234: 122701, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364498

RESUMO

Conventional methods for the detection of the sulfur mustard poisoning metabolic marker, thiodiglycol (TDG), require expensive instruments and reagents as well as professional operators. To address these problems, a novel test strip based on a molecularly imprinted sensitive membrane (MIM) was developed in this work for point-of-care (POC) detection of TDG. The TDG test strip was prepared conveniently by coating molecular imprinted polymers (MIPs) on a nitrocellulose membrane. When the sample contained TDG, the MIPs could specifically bind with TDG. A great number of AuNPs (AuNPs) could then be adsorbed on the test strip via the formation of an Au-S bond between TDG and AuNPs, giving the test strip the obvious red color of AuNPs. In the absence of TDG, the test strip exhibited much lighter color because it could not adsorb AuNPs. By monitoring the color change of the test strip, TDG could be detected from 1.0 ng/mL to 100.0 µg/mL with a detection limit of 0.23 ng/mL (3σ) under the optimal conditions (the molar ratio of TDG to MAA was 1:2; the eluent was chloroform; the elution time was 50 min; the reaction time between MIPs and TDG was 15 min; the adsorption time of AuNPs was 40 min; the temperature of the reaction system was 35 °C). This method has excellent selectivity and has been used to detect TDG in urine, showing great potential for POC detection of TDG in clinical samples.


Assuntos
Nanopartículas Metálicas , Impressão Molecular , Gás de Mostarda , Cromatografia Gasosa-Espectrometria de Massas , Ouro , Sistemas Automatizados de Assistência Junto ao Leito , Compostos de Sulfidrila
12.
Artigo em Inglês | MEDLINE | ID: mdl-34448119

RESUMO

Previous research has investigated the associations among childhood maltreatment, self-control, and aggression among adolescents without distinguishing between-person effects from within-person effects. Thus, we evaluated the dynamic longitudinal associations among childhood maltreatment, self-control, and aggression, including whether self-control functioned as a mediator of the reciprocal relations between childhood maltreatment and aggression at the within-person level after disentangling between- and within-person associations. A sample of 2050 Chinese early adolescents (43.69% girls, Mage = 10.39 years, SD = 0.55, range = 9 to 12 years at T1) completed measures on 5 occasions across 2.5 years, using 6-month intervals. Random Intercept Cross-Lagged Panel Models were applied to disaggregate between- and within-person effects. RI-CLPMs analysis revealed that at the within-person level: (a) Childhood maltreatment and aggression bidirectionally predicted each other; (b) Childhood maltreatment and self-control bidirectionally predicted each other; (c) Aggression predicted subsequent self-control but not vice versa; (d) Childhood maltreatment did not indirectly predict aggression via self-control and vice versa; (e) Additionally, there were no gender differences observed in the longitudinal associations among childhood maltreatment, self-control and aggression. These findings advanced the literature by elucidating longitudinal associations among childhood maltreatment, self-control, and aggression at the within-person level, highlighting the significance of distinguishing between- and within-person effects in research informing the development of prevention and intervention programs aimed at reducing adolescent aggression.

13.
Pharm Stat ; 2021 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-34449107

RESUMO

Medical diagnosis is essentially a classification problem and usually it is done with multiple ordered classes. For example, cancer diagnosis might be "non-malignant," "early stage," or "late stage." Therefore, appropriate measures are needed to assess the accuracy of diagnostic markers under multiple ordered classes. However, all existing measures fail to differentiate among some distinctly different biomarkers. This paper presents a multi-step procedure for evaluating biomarker accuracy under multiple ordered classes. This procedure leads to two new flexible overall measures as well as three new cut-point selection methods with great computational ease. The performance of proposed measures and cut-point selection methods are numerically explored via a simulation study. In the end, an ovarian cancer dataset from the Prostate, Lung, Colorectal, and Ovarian cancer study is analyzed. The proposed accuracy measures were estimated for markers CA125 and HE4, and cut-points were estimated for the risk of ovarian malignancy algorithm score.

14.
Environ Pollut ; 289: 117880, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34352632

RESUMO

Nitrated nonylphenols (NNPs) are main metabolites of the endocrine-disrupting nonylphenols in soil, yet their fate is unknown. Here, using four NNP isomers (NNP111, NNP112, NNP65, and NNP38), the degradation pattern of NNPs was investigated in an oxic soil for 266 days. Specifically, NNP111 was 14C-labeled to facilitate investigating its degradation, transformation, and non-extractable residue (NER) formation. NNPs degradation was isomer-specific with the decreasing order of half-life: NNP111 (126 days) > NNP112 (76 days) > NNP65 (14 days) > NNP38 (8.4 days), providing direct evidence of the greater persistence of NNPs in soil than their parent NPs. At the end of the incubation, 8.5 %, 7.3 %, and 39.9 % of 14C-NNP111 was mineralized, transformed to 2-amino-NP111, and formed NERs in active soil, respectively. In contrast, NERs in sterilized soils were significantly lower, amounting to 15.1 % and 17.3 % in autoclaved and γ-irradiated soil, respectively. The majority of the NERs (>70 %) were in humin fraction, in which type I NER was the predominant (>90 %) mode for NER formation. Our results provide comprehensive knowledge on the fate of NNPs in soil, demonstrating that isomer-specific behavior, transformation products of NNPs, and NER formation should be considered when evaluating environmental fate and risks of NNPs.


Assuntos
Poluentes do Solo , Solo , Nitratos , Fenóis/análise , Microbiologia do Solo , Poluentes do Solo/análise
15.
Atherosclerosis ; 333: 67-74, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34428605

RESUMO

BACKGROUND AND AIMS: Adult telomere length (TL) is substantially determined by birth TL, but associations of birth TL with cardiovascular disease (CVD) are unknown. METHODS: We included 144 adult offspring born in 1959-1966 from the Collaborative Perinatal Project, a US birth cohort. Birth TL was measured from banked cord blood with quantitative polymerase chain reaction. Atherosclerotic lesions were predicted by the Pathobiological Determinants of Atherosclerosis in Youth (PDAY) score that was based on blood pressure, lipids, hemoglobin A1c, and body weight at the midlife follow-up in 2003-2008 (average age: 42 years). Information on midlife CVD risk factors including the age at first diagnoses of hypertension, hypercholesterolemia, and diabetes was also collected. We used linear and logistic regression models to analyze associations of birth TL with the continuous PDAY score and categorical CVD risk factors, respectively, adjusting for prenatal confounders. RESULTS: At midlife follow-up, 31.2% and 18.7% of participants had ever been diagnosed with hypercholesterolemia and hypertension, respectively, and 8.3% met the criteria for metabolic syndrome. Short birth TL (Quartile 1, Q1) was associated with a higher PDAY score (adjusted ß: 1.78, 95% CI: 0.31, 3.25), increased odds of hypercholesterolemia (adjusted odds ratio [OR]: 3.23, 95% CI: 1.28, 8.18) and the presence of any cardiometabolic abnormalities (adjusted OR: 2.54, 95% CI: 1.00, 6.48) as compared to longer birth TL (Q2-Q4) after adjusting for prenatal confounders. CONCLUSIONS: People born with short TL may be at increased risk of predicted midlife atherosclerotic lesions and hypercholesterolemia. Future studies with larger sample sizes and CVD morbidities are warranted to replicate our findings.


Assuntos
Aterosclerose , Doenças Cardiovasculares , Adolescente , Adulto , Aterosclerose/diagnóstico , Aterosclerose/epidemiologia , Aterosclerose/genética , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/genética , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Gravidez , Fatores de Risco , Telômero
16.
J Nat Prod ; 84(9): 2468-2474, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34427432

RESUMO

Clonorosins A (1) and B (2), two novel indole alkaloids featuring unprecedented 6/5/6/6/5 and 6/5/5 cores, together with seven known indole-linked 2,5-diketopiperazine alkaloids (3-9), were isolated from the soil-derived fungus Clonostachys rosea YRS-06. The new structures were proposed through HR-MS, NMR, and ECD spectroscopic data. They were established by comparing the calculated NMR, ECD, and specific rotation data with the experimental. To assist in determining the absolute configuration of the chiral carbon in the side chain of 2,5-diketopiperazine derivatives, flexible analogues 3i-3iv were synthesized and analyzed. 1 was active against Fusarium oxysporum with an MIC value of 50 µg/mL. 7 and 8 showed excellent activity against human HeLa and HepG2 cells with IC50 values of 0.12-0.60 µM.

17.
Front Psychol ; 12: 699774, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34220657

RESUMO

While task-based peer interaction in dyads has been commonly practiced in English as a foreign language (EFL) classrooms, how to pair learners in dyadic tasks has always been a concern of teachers and researchers. This study examined learner proficiency pairing, task type and L1 use by Chinese EFL learners in two dyadic speaking tasks. Thirty-six participants were paired according to their oral English proficiency levels into: same-level pairs (high-high; medium-medium; low-low), and mixed-level pairs (high-low). All pairs completed two types of speaking tasks-information-gap and opinion-exchange. Quantitative results showed a significant difference between low-low pairs and other pairs in the amount of L1 use. Low-level learners produced significantly more L1 words and turns when paired with other low-level peers (low-low) than with high-level peers (high-low) in both types of tasks. Qualitative analysis further indicated that the mixed-level (high-low) pairs produced more opportunities for negotiation of meaning than the same-level (low-low) pairs during the interactional episodes where the L1 served various functions. The study offers pedagogical implications for EFL teachers about how to optimally pair learners to maximize their language development.

18.
Fitoterapia ; 153: 105000, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34303765

RESUMO

Six new polyketides, alternaritins A-D [(±)-1-4] and isoxanalteric acid I (8), and 25 known Alternaria toxins were isolated from the culture of an endophytic fungi Alternaria sp. MG1. 3 is a rare fungal metabolite. 6 is a new natural product, and 5, 7, and 9 are known previously but their absolute configurations have not been determined. Three enantiomers [(±)-1, (±)-7, and (±)-15] were separated via chiral HPLC resolution. The structures of those polyketides (1-9) were elucidated by spectrometric analysis using MS and NMR. The absolute configurations were established using X-ray diffraction analysis and statistical comparative analysis of the experimental ECD and OR data, in conjunction with quantum mechanical calculations. All of the compounds were evaluated for their bioactivities. Known compound 27 exerted the most potent cytotoxic activities against HT-1080 and NCI-H1299 cell lines. The new compounds, 2 and 3, showed moderate inhibition on COX-2, while a pair of isomers, 8 and 9, exhibited medium activity on COX-2 and uropathogenic Escherichia coli.


Assuntos
Alternaria/química , Anti-Inflamatórios/farmacologia , Antineoplásicos/farmacologia , Policetídeos/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Anti-Inflamatórios/isolamento & purificação , Antineoplásicos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Linhagem Celular Tumoral , Inibidores de Ciclo-Oxigenase 2/isolamento & purificação , Inibidores de Ciclo-Oxigenase 2/farmacologia , Endófitos/química , Humanos , Estrutura Molecular , Policetídeos/isolamento & purificação , Estereoisomerismo , Escherichia coli Uropatogênica/efeitos dos fármacos , Vitis/microbiologia
19.
Am J Physiol Endocrinol Metab ; 321(2): E292-E304, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34229476

RESUMO

We have generated the transgenic mouse line LTCFDN in which dominant negative TCF7L2 (TCF7L2DN) is specifically expressed in the liver during adulthood. Male but not female LTCFDN mice showed elevated hepatic and plasma triglyceride (TG) levels, indicating the existence of estrogen-ß-cat/TCF signaling cascade that regulates hepatic lipid homeostasis. We show here that hepatic fibroblast growth factor 21 (FGF21) expression was reduced in male but not in female LTCFDN mice. The reduction was not associated with altered hepatic expression of peroxisome proliferator-activated receptor α (PPARα). In mouse primary hepatocytes (MPH), Wnt-3a treatment increased FGF21 expression in the presence of PPARα inhibitor. Results from our luciferase-reporter assay and chromatin immunoprecipitation suggest that evolutionarily conserved TCF binding motifs (TCFBs) on Fgf21 promoter mediate Wnt-3a-induced Fgf21 transactivation. Female mice showed reduced hepatic FGF21 production and circulating FGF21 level following ovariectomy (OVX), associated with reduced hepatic TCF expression and ß-catenin S675 phosphorylation. Finally, in MPH, estradiol (E2) treatment enhanced FGF21 expression, as well as binding of TCF7L2 and ribonucleic acid (RNA) polymerase II to the Fgf21 promoter; and the enhancement can be attenuated by the G-protein-coupled estrogen receptor 1 (GPER) antagonist G15. Our observations hence indicate that hepatic FGF21 is among the effectors of the newly recognized E2-ß-cat/TCF signaling cascade.NEW & NOTEWORTHY FGF21 is mainly produced in the liver. Therapeutic effect of FGF21 analogues has been demonstrated in clinical trials on reducing hyperlipidemia. We show here that Fgf21 transcription is positively regulated by Wnt pathway effector ß-cat/TCF. Importantly, hepatic ß-cat/TCF activity can be regulated by the female hormone estradiol, involving GPER. The investigation enriched our understanding on hepatic FGF21 hormone production, and expanded our view on metabolic functions of the Wnt pathway in the liver.


Assuntos
Fatores de Crescimento de Fibroblastos/metabolismo , Fígado/metabolismo , Via de Sinalização Wnt , Animais , Células Cultivadas , Estrogênios/metabolismo , Feminino , Regulação da Expressão Gênica , Hepatócitos/metabolismo , Masculino , Camundongos , Camundongos Transgênicos , PPAR alfa/metabolismo
20.
J Affect Disord ; 294: 322-328, 2021 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311332

RESUMO

BACKGROUND: Bullying victimization is becoming an increasing problem among children. This longitudinal study examined the relation of bullying victimization (both traditional and cyberbullying victimization) to subsequent depressive symptoms and the possible mediating role of self-esteem among children. METHODS: A total of 4043 Chinese elementary school children in Grades 3 and 4 comprised the sample. Assessments were conducted every six months on five occasions. Latent growth curve modeling was applied to examine the longitudinal relations among the variables. RESULTS: Results showed that (a) bullying victimization was positively and significantly associated with subsequent depressive symptoms; (b) self-esteem played an important mediating role in the relation between bullying victimization and depressive symptoms. LIMITATIONS: The study only considered self-esteem as a mediator. The generalizability of the results should be made cautiously. CONCLUSIONS: The results highlight the relation between bullying victimization and depressive symptoms among children, suggesting that intervention programs target bullying victimization and self-esteem to reduce the likelihood of depressive symptoms among children.


Assuntos
Bullying , Vítimas de Crime , Cyberbullying , Criança , Depressão/epidemiologia , Humanos , Estudos Longitudinais
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