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1.
Front Psychol ; 13: 1046775, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36743638

RESUMO

Academic challenges and failure are inevitable in pursuit of higher education. According to the self-worth theory, trying hard but failing implies low ability that would be a threat to personal worth, thus preventing students from approaching academic challenges. Nevertheless, previous studies have shown that students in the Confucian-heritage contexts (CHCs) tend to persist rather than quit in the face of academic failure. According to the role obligation theory of self-cultivation (ROT), the CHC learners would perceive academic failure from personal and interpersonal perspectives. The former refers to personal obligations to exert oneself toward the ultimate good, and the latter refers to fulfilling filial obligations to parents by achieving academic excellence. Given the fundamental differences in learners' perceptions of academic failure between the CHCs and the Western, Educated, Industrialized, Rich, and Democratic (WEIRD) contexts, this study examined the applicability of the quadripolar model of achievement motivation based on the self-worth theory in a CHC higher education institution. Results of confirmatory factor analysis (CFA) supported a two-factor model of fear of failure, including a personal and an interpersonal subfactor. Latent class analysis (LCA) showed that apart from the four existing categories of the quadripolar model, two additional CHC categories emerged and constituted half of the sample. The two CHC categories demonstrated different learner characteristics compared with their corresponding quadripolar categories in terms of levels of emotional distress and academic risk-taking tendency. The results may help debunk the myth that learner characteristics in the CHCs are identical to those observed in the WEIRD contexts. The fundamental differences in fear of failure further indicated the inadequacy of the self-worth theory in explaining achievement motivation in the CHCs where relationalism and role obligations are significant parts of the cultural traditions.

2.
Front Psychol ; 11: 615, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457674

RESUMO

Understanding reading comprehension processes is vital for teachers to effectively conduct teaching and assessment of reading in schools. Hong Kong students' outstanding reading performance internationally is commonly attributed to the implementation of reading comprehension models in its Chinese language curriculum, however, the understanding of teachers' conceptions of reading comprehension is still very limited. This phenomenographic study interviewed 28 in-service Chinese language teachers from eight Hong Kong primary schools and illustrated the elicited conceptions of a model of reading comprehension processes (i.e., Six Types of Reading Comprehension Process Model, a widely used model in Hong Kong). The three categories of teachers' conceptions found are as follows: understanding basic ideas of a text, sequential development of holistic comprehension skills, and fostering independent readers. This study further employed sense-making theory to investigate the formulation of the teachers' conceptions. It is found that the conceptions were shaped when teachers' conventional practices that focused on rote-learning interplayed with the continual regulating means of the implementation. Teachers are also highly influenced by factors like attainability by their students and agreement with own philosophy. This study also implied that teachers' beliefs will need to be brought to light in order for new learning to happen.

3.
Front Plant Sci ; 10: 91, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30800136

RESUMO

The disease caused by Sclerotinia sclerotiorum has traditionally been difficult to control, resulting in tremendous economic losses in oilseed rape (Brassica napus). Identification of important genes in the defense responses is critical for molecular breeding, an important strategy for controlling the disease. Here, we report that a B. napus mitogen-activated protein kinase gene, BnaMPK3, plays an important role in the defense against S. sclerotiorum in oilseed rape. BnaMPK3 is highly expressed in the stems, flowers and leaves, and its product is localized in the nucleus. Furthermore, BnaMPK3 is highly responsive to infection by S. sclerotiorum and treatment with jasmonic acid (JA) or the biosynthesis precursor of ethylene (ET), but not to treatment with salicylic acid (SA) or abscisic acid. Moreover, overexpression (OE) of BnaMPK3 in B. napus and Nicotiana benthamiana results in significantly enhanced resistance to S. sclerotiorum, whereas resistance is diminished in RNAi transgenic plants. After S. sclerotiorum infection, defense responses associated with ET, JA, and SA signaling are intensified in the BnaMPK3-OE plants but weakened in the BnaMPK3-RNAi plants when compared to those in the wild type plants; by contrast the level of both H2O2 accumulation and cell death exhibits a reverse pattern. The candidate gene association analyses show that the BnaMPK3-encoding BnaA06g18440D locus is a cause of variation in the resistance to S. sclerotiorum in natural B. napus population. These results suggest that BnaMPK3 is a key regulator of multiple defense responses to S. sclerotiorum, which may guide the resistance improvement of oilseed rape and related economic crops.

4.
J Inorg Biochem ; 141: 17-27, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25172994

RESUMO

Three novel copper(II) complexes CuL(1)Cl2 (1) (L(1)=4'-(3-methoxyphenyl)-2,2':6'- 2″-terpyridine), CuL(2)Cl2 (2) (L(2)=4'-(4-methoxyphenyl)-2,2':6'-2″-terpyridine) and CuL(3)Cl2 (3) (L(3)=4'-(3,5-dimethoxyphenyl)-2,2':6'-2″-terpyridine) have been synthesized and characterized. Absorption spectral titration experiments, ethidium bromide displacement assays, and cyclic voltammetric experiments were carried out and the results suggested that these complexes bound to DNA through an intercalative mode. Moreover, these complexes were found to cleave pBR322 DNA efficiently in the presence of glutathione (GSH), and exhibited good anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage was also observed by acridine orange/ethidium bromide (AO/EB) staining assays and comet assays. These results demonstrated that these three Cu(II) complexes caused DNA damage and induced the apoptosis of HeLa cells. Mechanistic investigations revealed the participation of reactive oxygen species which can be trapped by reactive oxygen species (ROS) radical scavengers and ROS sensors.


Assuntos
Antineoplásicos/síntese química , Complexos de Coordenação/síntese química , Cobre/química , Citotoxinas/síntese química , Substâncias Intercalantes/síntese química , Piridinas/química , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Cátions Bivalentes , Bovinos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Complexos de Coordenação/farmacologia , Citotoxinas/farmacologia , DNA/química , Fragmentação do DNA/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Substâncias Intercalantes/farmacologia , Espécies Reativas de Oxigênio/metabolismo
5.
J Inorg Biochem ; 121: 108-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23376332

RESUMO

A dinuclear ruthenium(II) complex linked via a reducible azo group [Ru(bpy)2(azobpy)Ru(bpy)2]Cl4 (Ru2azo, bpy=2,2'-bipyridine, azobpy=4,4″-azobis (2,2'-bipyridine)) was adopted as a probe for thiols. Results showed that Ru2azo could selectively and effectively react with biological thiols (such as cysteine, homocysteine and glutathione) with a 10(-7)M detection limit. After it reacted with thiols, the original gray color of Ru2azo solution immediately turned yellow and the luminescence significantly enhanced, showing "naked-eye" colorimetric and "off-on" luminescent dual-signaling response for thiols. Mechanism studies demonstrated that Ru2azo reacted with thiols undergoing a two-electron transfer process, forming the azo(2-) anion product.


Assuntos
Complexos de Coordenação/química , Cisteína/análise , Glutationa/análise , Homocisteína/análise , Sondas Moleculares/química , Rutênio/química , Complexos de Coordenação/síntese química , Transporte de Elétrons , Limite de Detecção , Medições Luminescentes , Sondas Moleculares/síntese química , Soluções
6.
J Inorg Biochem ; 119: 43-53, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23186647

RESUMO

Three new tridentate copper(II) complexes [Cu(dthp)Cl(2)] (1) (dthp=2,6-di(thiazol-2-yl)pyridine), [Cu(dmtp)Cl(2)] (2) (dmtp=2,6-di(5-methyl-4H-1,2,4-triazol-3-yl)pyridine) and [Cu(dtp)Cl(2)] (3) (dtp=2,6-di(4H-1,2,4-triazol-3-yl)pyridine) have been synthesized and characterized. Crystal structure of complex 1 shows that the complex existed as distorted square pyramid with five co-ordination sites occupied by the tridentate ligand and the two chlorine anions. Ethidium bromide displacement assay, viscosity measurements, circular dichroism studies and cyclic voltammetric experiments suggested that these complexes bound to DNA via an intercalative mode. Three Cu(II) complexes were found to efficiently cleave DNA in the presence of sodium ascorbate, and singlet oxygen ((1)O(2)) and hydrogen peroxide were proved to contribute to the DNA cleavage process. They exhibited anticancer activity against HeLa, Hep-G2 and BEL-7402 cell lines. Nuclear chromatin cleavage has also been observed with AO/EB staining assay and the alkaline single-cell gel electrophoresis (comet assay). The results demonstrated that three Cu(II) complexes cause DNA damage that can induce the apoptosis of BEL-7402 cells.


Assuntos
Antineoplásicos/síntese química , Complexos de Coordenação/síntese química , Cobre/química , DNA/química , Substâncias Intercalantes/síntese química , Piridinas/síntese química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ácido Ascórbico/química , Linhagem Celular Tumoral , Dicroísmo Circular , Ensaio Cometa , Complexos de Coordenação/farmacologia , Cristalografia por Raios X , Clivagem do DNA/efeitos dos fármacos , Etídio , Humanos , Substâncias Intercalantes/farmacologia , Modelos Moleculares , Oxirredução , Piridinas/farmacologia , Oxigênio Singlete/química
7.
Eur J Med Chem ; 46(4): 1056-65, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21295892

RESUMO

Two ruthenium(II) complexes [Ru(bpy)(2)(bfipH)](2+) (1) and [Ru(phen)(2)(bfipH)](2+) (2) have been synthesized and characterized. The DNA-binding behaviors of complexes were studied by using spectroscopic and viscosity measurements. Results suggested that the two complexes bind to DNA in an intercalative mode. Complexes 1 and 2 can efficiently photocleave pBR322 DNA in vitro under irradiation, singlet oxygen ((1)O(2)) was proved to contribute to the DNA photocleavage process. Topoisomerase inhibition and DNA strand passage assay confirmed that two Ru(II) complexes acted as efficient dual inhibitors of topoisomerases I and II. In MTT cytotoxicity studies, two Ru(II) complexes exhibited antitumor activity against BEL-7402, HeLa, MCF-7 tumor cells. The AO/EB staining assay indicated that Ru(II) complexes could induce the apoptosis of HeLa cells.


Assuntos
DNA Topoisomerases/metabolismo , DNA/metabolismo , Compostos Organometálicos/metabolismo , Compostos Organometálicos/farmacologia , Rutênio/química , Inibidores da Topoisomerase/metabolismo , Inibidores da Topoisomerase/farmacologia , Animais , Bovinos , Linhagem Celular Tumoral , Cristalografia por Raios X , DNA/química , Clivagem do DNA/efeitos dos fármacos , Clivagem do DNA/efeitos da radiação , Humanos , Concentração Inibidora 50 , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Inibidores da Topoisomerase/síntese química , Inibidores da Topoisomerase/química
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